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Sample records for biological materials involving

  1. NASA Sponsored Research Involving Crystallization of Biological Materials

    NASA Technical Reports Server (NTRS)

    Downey, James Patton

    2000-01-01

    An overview of NASA's plans for the performing experiments involving the crystallization of biological materials on the International Space Station (ISS) is presented. In addition, a brief overview of past work is provided as background. Descriptions of flight hardware currently available for use on the ISS are given and projections of future developments are discussed. In addition, experiment selection and funding is described. As of the flight of STS-95, these crystallization projects have proven to be some of the most successful in the history of microgravity research. The NASA Microgravity Research Division alone has flown 185 different proteins, nucleic acids, viruses, and complexes on 43 different missions. 37 of the 185 have resulted, in, diffraction patterns with higher resolution than was obtained in all previous ground based experiments. This occurred despite the fact that an average of only 41 samples per protein were flown. A number of other samples have shown improved signal to noise characteristics, i.e. relative Wilson plots, when compared to the best ground experiments. In addition, a number of experiments investigating the effects of microgravity conditions on the crystallization of biological material have been conducted.

  2. NASA Sponsored Research Involving Crystallization of Biological Materials

    NASA Technical Reports Server (NTRS)

    Downey, James Patton

    2000-01-01

    An overview of NASA's plans for the performing experiments involving the crystallization of biological materials on the International Space Station (ISS) is presented. In addition, a brief overview of past work is provided as background. Descriptions of flight hardware currently available for use on the ISS are given and projections of future developments are discussed. In addition, experiment selection and funding is described. As of the flight of STS-95, these crystallization projects have proven to be some of the most successful in the history of microgravity research. The NASA Microgravity Research Division alone has flown 185 different proteins, nucleic acids, viruses, and complexes on 43 different missions. 37 of the 185 have resulted, in, diffraction patterns with higher resolution than was obtained in all previous ground based experiments. This occurred despite the fact that an average of only 41 samples per protein were flown. A number of other samples have shown improved signal to noise characteristics, i.e. relative Wilson plots, when compared to the best ground experiments. In addition, a number of experiments investigating the effects of microgravity conditions on the crystallization of biological material have been conducted.

  3. Organizational influence on the occurrence of work accidents involving exposure to biological material.

    PubMed

    Marziale, Maria Helena Palucci; Rocha, Fernanda Ludmilla Rossi; Robazzi, Maria Lúcia do Carmo Cruz; Cenzi, Camila Maria; dos Santos, Heloisa Ehmke Cardoso; Trovó, Marli Elisa Mendes

    2013-01-01

    to analyze work accidents involving exposure to biological materials which took place among personnel working in nursing and to evaluate the influence of the organizational culture on the occurrence of these accidents. a retrospective, analytical study, carried out in two stages in a hospital that was part of the Network for the Prevention of Work Accidents. The first stage involved the analysis of the characteristics of the work accidents involving exposure to biological materials as recorded over a seven-year period by the nursing staff in the hospital studied, and registered in the Network databank. The second stage involved the analysis of 122 nursing staff members' perception of the institutional culture, who were allocated to the control group (workers who had not had an accident) and the case group (workers who had had an accident). 386 accidents had been recorded: percutaneous lesions occurred in 79% of the cases, needles were the materials involved in 69.7% of the accidents, and in 81.9% of the accident there was contact with blood. Regarding the influence of the organizational culture on the occurrence of accidents, the results obtained through the analysis of the two groups did not demonstrate significant differences between the average scores attributed by the workers in each organizational value or practice category. It is concluded that accidents involving exposure to biological material need to be avoided, however, it was not possible to confirm the influence of organizational values or practices on workers' behavior concerning the occurrence of these accidents.

  4. Biological materials by design.

    PubMed

    Qin, Zhao; Dimas, Leon; Adler, David; Bratzel, Graham; Buehler, Markus J

    2014-02-19

    In this topical review we discuss recent advances in the use of physical insight into the way biological materials function, to design novel engineered materials 'from scratch', or from the level of fundamental building blocks upwards and by using computational multiscale methods that link chemistry to material function. We present studies that connect advances in multiscale hierarchical material structuring with material synthesis and testing, review case studies of wood and other biological materials, and illustrate how engineered fiber composites and bulk materials are designed, modeled, and then synthesized and tested experimentally. The integration of experiment and simulation in multiscale design opens new avenues to explore the physics of materials from a fundamental perspective, and using complementary strengths from models and empirical techniques. Recent developments in this field illustrate a new paradigm by which complex material functionality is achieved through hierarchical structuring in spite of simple material constituents.

  5. Active Biological Materials

    NASA Astrophysics Data System (ADS)

    Fletcher, Daniel A.; Geissler, Phillip L.

    2009-05-01

    Cells make use of dynamic internal structures to control shape and create movement. By consuming energy to assemble into highly organized systems of interacting parts, these structures can generate force and resist compression, as well as adaptively change in response to their environment. Recent progress in reconstituting cytoskeletal structures in vitro has provided an opportunity to characterize the mechanics and dynamics of filament networks formed from purified proteins. Results indicate that a complex interplay between length scales and timescales underlies the mechanical responses of these systems and that energy consumption, as manifested in molecular motor activity and cytoskeletal filament growth, can drive transitions between distinct material states. This review discusses the basic characteristics of these active biological materials that set them apart from conventional materials and that create a rich array of unique behaviors.

  6. Electrophoresis of biological materials

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The selection of biological products was studied for electrophoresis in space. Free flow electrophoresis, isoelectric focusing, and isotachophoresis are described. The candidates discussed include: immunoglobulins and gamma globulins; isolated islet of langerhans from pancreas; bone marrow; tumor cells; kidney cells, cryoprecipitate; and column separated cultures.

  7. Electrophoresis of biological materials

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The selection of biological products was studied for electrophoresis in space. Free flow electrophoresis, isoelectric focusing, and isotachophoresis are described. The candidates discussed include: immunoglobulins and gamma globulins; isolated islet of langerhans from pancreas; bone marrow; tumor cells; kidney cells, cryoprecipitate; and column separated cultures.

  8. Liquid Crystalline Materials for Biological Applications.

    PubMed

    Lowe, Aaron M; Abbott, Nicholas L

    2012-03-13

    Liquid crystals have a long history of use as materials that respond to external stimuli (e.g., electrical and optical fields). More recently, a series of investigations have reported the design of liquid crystalline materials that undergo ordering transitions in response to a range of biological interactions, including interactions involving proteins, nucleic acids, viruses, bacteria and mammalian cells. A central challenge underlying the design of liquid crystalline materials for such applications is the tailoring of the interface of the materials so as to couple targeted biological interactions to ordering transitions. This review describes recent progress toward design of interfaces of liquid crystalline materials that are suitable for biological applications. Approaches addressed in this review include the use of lipid assemblies, polymeric membranes containing oligopeptides, cationic surfactant-DNA complexes, peptide-amphiphiles, interfacial protein assemblies and multi-layer polymeric films.

  9. Biological materials: a materials science approach.

    PubMed

    Meyers, Marc A; Chen, Po-Yu; Lopez, Maria I; Seki, Yasuaki; Lin, Albert Y M

    2011-07-01

    The approach used by Materials Science and Engineering is revealing new aspects in the structure and properties of biological materials. The integration of advanced characterization, mechanical testing, and modeling methods can rationalize heretofore unexplained aspects of these structures. As an illustration of the power of this methodology, we apply it to biomineralized shells, avian beaks and feathers, and fish scales. We also present a few selected bioinspired applications: Velcro, an Al2O3-PMMA composite inspired by the abalone shell, and synthetic attachment devices inspired by gecko. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Biologically inspired dynamic material systems.

    PubMed

    Studart, André R

    2015-03-09

    Numerous examples of material systems that dynamically interact with and adapt to the surrounding environment are found in nature, from hair-based mechanoreceptors in animals to self-shaping seed dispersal units in plants to remodeling bone in vertebrates. Inspired by such fascinating biological structures, a wide range of synthetic material systems have been created to replicate the design concepts of dynamic natural architectures. Examples of biological structures and their man-made counterparts are herein revisited to illustrate how dynamic and adaptive responses emerge from the intimate microscale combination of building blocks with intrinsic nanoscale properties. By using top-down photolithographic methods and bottom-up assembly approaches, biologically inspired dynamic material systems have been created 1) to sense liquid flow with hair-inspired microelectromechanical systems, 2) to autonomously change shape by utilizing plantlike heterogeneous architectures, 3) to homeostatically influence the surrounding environment through self-regulating adaptive surfaces, and 4) to spatially concentrate chemical species by using synthetic microcompartments. The ever-increasing complexity and remarkable functionalities of such synthetic systems offer an encouraging perspective to the rich set of dynamic and adaptive properties that can potentially be implemented in future man-made material systems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. 78 FR 16472 - Deposit of Biological Materials

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... United States Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection....'' SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part of a patent application is... use the invention as specified by 35 U.S.C. 112. The term ``biological material'' is defined by 37...

  12. 75 FR 6348 - Deposit of Biological Materials

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection; comment request....Fawcett@uspto.gov . Include ``0651-0022 Deposit of Biological Materials comment'' in the subject line of....Hanlon@uspto.gov . SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part...

  13. Biological issues in materials science and engineering: Interdisciplinarity and the bio-materials paradigm

    NASA Astrophysics Data System (ADS)

    Murr, L. E.

    2006-07-01

    Biological systems and processes have had, and continue to have, important implications and applications in materials extraction, processing, and performance. This paper illustrates some interdisciplinary, biological issues in materials science and engineering. These include metal extraction involving bacterial catalysis, galvanic couples, bacterial-assisted corrosion and degradation of materials, biosorption and bioremediation of toxic and other heavy metals, metal and material implants and prostheses and related dental and medical biomaterials developments and applications, nanomaterials health benefits and toxicity issue, and biomimetics and biologically inspired materials developments. These and other examples provide compelling evidence and arguments for emphasizing biological sicences in materials science and engineering curricula and the implementation of a bio-materials paradigm to facilitate the emergence of innovative interdisciplinarity involving the biological sciences and materials sciences and engineering.

  14. Bioinspired materials: Boosting plant biology

    NASA Astrophysics Data System (ADS)

    Scholes, Gregory D.; Sargent, Edward H.

    2014-04-01

    Chloroplasts with extended photosynthetic activity beyond the visible absorption spectrum, and living leaves that perform non-biological functions, are made possible by localizing nanoparticles within plant organelles.

  15. [Applications of synthetic biology in materials science].

    PubMed

    Zhao, Tianxin; Zhong, Chao

    2017-03-25

    Materials are the basis for human being survival and social development. To keep abreast with the increasing needs from all aspects of human society, there are huge needs in the development of advanced materials as well as high-efficiency but low-cost manufacturing strategies that are both sustainable and tunable. Synthetic biology, a new engineering principle taking gene regulation and engineering design as the core, greatly promotes the development of life sciences. This discipline has also contributed to the development of material sciences and will continuously bring new ideas to future new material design. In this paper, we review recent advances in applications of synthetic biology in material sciences, with the focus on how synthetic biology could enable synthesis of new polymeric biomaterials and inorganic materials, phage display and directed evolution of proteins relevant to materials development, living functional materials, engineered bacteria-regulated artificial photosynthesis system as well as applications of gene circuits for material sciences.

  16. Biological and environmental reference materials in CENAM.

    PubMed

    Arvizu-Torres, R; Perez-Castorena, A; Salas-Tellez, J A; Mitani-Nakanishi, Y

    2001-06-01

    Since 1994, when the NIST/NOAA Quality Assurance Program in Chemical Measurements was discussed in Queretaro, CENAM, the National Measurement Institute (NMI) of Mexico, has become involved in the development of reference materials. In the field of biological and environmental reference materials, in particular, the NORAMET collaboration program with NIST and NRC, and the North-American Environmental Cooperation signed among three free-trade treaty organizations, have greatly helped the development of the materials metrology program in the newly established CENAM. This paper describes some particularly significant efforts of CENAM in the development of biological and environmental reference materials, on the basis of inter-comparison studies organized with local and governmental environmental agencies of Mexico. In the field of water pollution CENAM has developed a practical proficiency testing (PT) scheme for field laboratories, as a part of registration by local government in the metropolitan area, according to the Mexican Ecological Regulation. The results from these eight PTs in the last 5 years have demonstrated that this scheme has helped ensure the reliability of analytical capability of more than 50 field laboratories in three states, Mexico, D.F., and the States of Mexico and Queretaro. Similar experience has been obtained for more than 70 service units of stack emission measurements in the three states in 1998 and 1999, as a result of the design of a PT scheme for reference gas mixtures. This PT scheme has been accomplished successfully by 30 analytical laboratories who provide monitoring services and perform research on toxic substances (Hg, methylmercury, PCB, etc.) in Mexico. To support these activities, reference samples have been produced through the NIST SRMs, and efforts have been made to increase CENAM's capability in the preparation of primary reference materials in spectrometric solutions and gas mixtures. Collaboration among NMIs has also

  17. Immune response to biologic scaffold materials.

    PubMed

    Badylak, Stephen F; Gilbert, Thomas W

    2008-04-01

    Biologic scaffold materials composed of mammalian extracellular matrix are commonly used in regenerative medicine and in surgical procedures for the reconstruction of numerous tissue and organs. These biologic materials are typically allogeneic or xenogeneic in origin and are derived from tissues such as small intestine, urinary bladder, dermis, and pericardium. The innate and acquired host immune response to these biologic materials and the effect of the immune response upon downstream remodeling events has been largely unexplored. Variables that affect the host response include manufacturing processes, the rate of scaffold degradation, and the presence of cross species antigens. This manuscript provides an overview of studies that have evaluated the immune response to biologic scaffold materials and variables that affect this response.

  18. Biomineralization: From Material Tactics to Biological Strategy.

    PubMed

    Yao, Shasha; Jin, Biao; Liu, Zhaoming; Shao, Changyu; Zhao, Ruibo; Wang, Xiaoyu; Tang, Ruikang

    2017-04-01

    Biomineralization is an important tactic by which biological organisms produce hierarchically structured minerals with marvellous functions. Biomineralization studies typically focus on the mediation function of organic matrices on inorganic minerals, which helps scientists to design and synthesize bioinspired functional materials. However, the presence of inorganic minerals may also alter the native behaviours of organic matrices and even biological organisms. This progress report discusses the latest achievements relating to biomineralization mechanisms, the manufacturing of biomimetic materials and relevant applications in biological and biomedical fields. In particular, biomineralized vaccines and algae with improved thermostability and photosynthesis, respectively, demonstrate that biomineralization is a strategy for organism evolution via the rational design of organism-material complexes. The successful modification of biological systems using materials is based on the regulatory effect of inorganic materials on organic organisms, which is another aspect of biomineralization control. Unlike previous studies, this study integrates materials and biological science to achieve a more comprehensive view of the mechanisms and applications of biomineralization. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Biological Potential of Extraterrestrial Materials

    NASA Astrophysics Data System (ADS)

    Mautner, Michael N.; Conner, Anthony J.; Killham, Kenneth; Deamer, David W.

    1997-09-01

    Meteoritic materials are investigated as potential early planetary nutrients. Aqueous extracts of the Murchison C2 carbonaceous meteorite are utilized as a sole carbon source by microorganisms, as demonstrated by the genetically modifiedPseudomonas fluorescenceequipped with theluxgene. Nutrient effects are observed also with the soil microorganismsNocardia asteroidesandArthrobacter pascensthat reach populations up to 5 × 107CFU/ml in meteorite extracts, similar to populations in terrestrial soil extracts. Plant tissue cultures ofAsparagus officinalisandSolanum tuberosum(potato) exhibit enhanced pigmentation and some enhanced growth when meteorite extracts are added to partial nutrient media, but inhibited growth when added to full nutrient solution. The meteorite extracts lead to large increases in S, Ca, Mg, and Fe plant tissue contents as shown by X-ray fluorescence, while P, K, and Cl contents show mixed effects. In both microbiological and plant tissue experiments, the nutrient and inhibitory effects appear to be best balanced for growth at about 1:20 (extracted solid:H2O) ratios. The results suggest that solutions in cavities in meteorites can provide efficient concentrated biogenic and early nutrient environments, including high phosphate levels, which may be the limiting nutrient. The results also suggest that carbonaceous asteroid resources can sustain soil microbial activity and provide essential macronutrients for future space-based eco- systems.

  20. Additive manufacturing of biologically-inspired materials.

    PubMed

    Studart, André R

    2016-01-21

    Additive manufacturing (AM) technologies offer an attractive pathway towards the fabrication of functional materials featuring complex heterogeneous architectures inspired by biological systems. In this paper, recent research on the use of AM approaches to program the local chemical composition, structure and properties of biologically-inspired materials is reviewed. A variety of structural motifs found in biological composites have been successfully emulated in synthetic systems using inkjet-based, direct-writing, stereolithography and slip casting technologies. The replication in synthetic systems of design principles underlying such structural motifs has enabled the fabrication of lightweight cellular materials, strong and tough composites, soft robots and autonomously shaping structures with unprecedented properties and functionalities. Pushing the current limits of AM technologies in future research should bring us closer to the manufacturing capabilities of living organisms, opening the way for the digital fabrication of advanced materials with superior performance, lower environmental impact and new functionalities.

  1. Biological and environmental reference materials: Update 1996

    NASA Astrophysics Data System (ADS)

    Roelandts, Iwan

    1997-07-01

    The present column lists additional biological and environmental reference samples. Organs, tissues, body fluids, plant materials, foods, fuels, ashes, dusts, particulate matter, gas mixtures, oils, soils, sediments, sludges and waters have been considered. Three tables are included that provide an easy-to-use survey. The following information is covered: the name of the material, the sample code, the producer, the reference to certification, the names and addresses of the suppliers from whom the reference material may be obtained, and specific remarks.

  2. New materials for microfluidics in biology.

    PubMed

    Ren, Kangning; Chen, Yin; Wu, Hongkai

    2014-02-01

    With its continuous progress, microfluidics has become a key enabling technology in biological research. During the past few years, the major growth of microfluidics shifted to the introduction of new materials in making microfluidic chips, primarily driven by the demand of versatile strategies to interface microfluidics with biological cell studies. Although polydimethylsiloxane is still used as primary frame material, hydrogels have been increasingly employed in cell-culture related applications. Moreover, plastics and paper are attracting more attention in commercial device fabrication. Aiming to reflect this trend, current review focuses on the progress of microfluidic chip materials over the time span of January 2011 through June 2013, and provides critical discussion of the resulting major new tools in biological research.

  3. Biomimetic smart interface materials for biological applications.

    PubMed

    Sun, Taolei; Qing, Guangyan

    2011-03-25

    Controlling the surface chemical and physical properties of materials and modulating the interfacial behaviors of biological entities, e.g., cells and biomolecules, are central tasks in the study of biomaterials. In this context, smart polymer interface materials have recently attracted much interest in biorelated applications and have broad prospects due to the excellent controllability of their surface properties by external stimuli. Among such materials, poly(N-isopropylacrylamide) and its copolymer films are especially attractive due to their reversible hydrogen-bonding-mediated reversible phase transition, which mimics natural biological processes. This platform is promising for tuning surface properties or to introduce novel biofunctionalities via copolymerization with various functional units and/or combination with other materials. Important progress in this field in recent years is highlighted. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Multiparameter integrated sensor development involving alternate materials

    NASA Astrophysics Data System (ADS)

    Rajic, Slobodan; Datskos, Panos G.

    2001-11-01

    The sensor community has long been presented with the problem of prioritizing among several competing sensor system variables due to the inability to produce a high confidence, low-cost, reliable, and compact device. Typically a solution for very critical scenarios has been a high-cost scale reduction of larger more laboratory based instrumentation. This often produces data on a single parameter that is beyond reproach, however this can also produce a very delicate, bulky, and costly system often requiring a vacuum system of some sort. An alternative approach involves using micro-opto-electro-mechanical systems (MOEMS) based sensors. This typically results in low-cost and extremely compact devices that often produce dubious or insufficient data. Our approach integrates multiple orthogonal stimuli within a single chip to produce a MOEMS based sensor that has a very high degree of signal confidence. The combination of multiple independent parameters significantly improves detection reliability in a small low-cost package. However, it is often the case that the most efficient MOEMS sensing methods require the use of material properties other than the conventional microlithograph based Si, SiNx, SiO2 and metals. Thus we have been developing techniques to employ more exotic semiconductors for various sensing applications. The group III-V and II-VI compound semiconductors form a very important and versatile collection of material property variables (thermal, optical, mechanical, electrical) available to the MOEMS designer.

  5. 37 CFR 1.801 - Biological material.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Biological material. 1.801 Section 1.801 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  6. 37 CFR 1.801 - Biological material.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Biological material. 1.801 Section 1.801 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  7. 37 CFR 1.801 - Biological material.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Biological material. 1.801 Section 1.801 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  8. 37 CFR 1.801 - Biological material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Biological material. 1.801 Section 1.801 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  9. 37 CFR 1.801 - Biological material.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Biological material. 1.801 Section 1.801 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit...

  10. [PROGRESS IN BIOLOGICAL TISSUE ENGINEERING SCAFFOLD MATERIALS].

    PubMed

    Wei, Xiaojuan; Xi, Tingfei; Zheng, Yufeng

    2014-06-01

    To analyze the progress in biological tissue engineering scaffold materials and the clinical application, as well as product development status. Based on extensive investigation in the status of research and application of biological tissue engineering scaffold materials, a comprehensive analysis was made. Meanwhile, a detailed analysis of research and product development was presented. Considerable progress has been achieved in research, products transformation, clinical application, and supervision of biological scaffold for tissue engineering. New directions, new technology, and new products are constantly emerging. With the continuous progress of science and technology and continuous improvement of life sciences theory, the new direction and new focus still need to be continuously adjusted in order to meet the clinical needs. From the aspect of industrial transformation feasibility, acellular scaffolds and extracellular matrix are the most promising new growth of both research and product development in this field.

  11. Using Raman spectroscopy to characterize biological materials.

    PubMed

    Butler, Holly J; Ashton, Lorna; Bird, Benjamin; Cinque, Gianfelice; Curtis, Kelly; Dorney, Jennifer; Esmonde-White, Karen; Fullwood, Nigel J; Gardner, Benjamin; Martin-Hirsch, Pierre L; Walsh, Michael J; McAinsh, Martin R; Stone, Nicholas; Martin, Francis L

    2016-04-01

    Raman spectroscopy can be used to measure the chemical composition of a sample, which can in turn be used to extract biological information. Many materials have characteristic Raman spectra, which means that Raman spectroscopy has proven to be an effective analytical approach in geology, semiconductor, materials and polymer science fields. The application of Raman spectroscopy and microscopy within biology is rapidly increasing because it can provide chemical and compositional information, but it does not typically suffer from interference from water molecules. Analysis does not conventionally require extensive sample preparation; biochemical and structural information can usually be obtained without labeling. In this protocol, we aim to standardize and bring together multiple experimental approaches from key leaders in the field for obtaining Raman spectra using a microspectrometer. As examples of the range of biological samples that can be analyzed, we provide instructions for acquiring Raman spectra, maps and images for fresh plant tissue, formalin-fixed and fresh frozen mammalian tissue, fixed cells and biofluids. We explore a robust approach for sample preparation, instrumentation, acquisition parameters and data processing. By using this approach, we expect that a typical Raman experiment can be performed by a nonspecialist user to generate high-quality data for biological materials analysis.

  12. THE BIOLOGICAL ACTIONS OF DEHYDROEPIANDROSTERONE INVOLVES MULTIPLE RECEPTORS

    PubMed Central

    Webb, Stephanie J.; Geoghegan, Thomas E.; Prough, Russell A.; Miller, Kristy K. Michael

    2008-01-01

    Dehydroepiandrosterone has been thought to have physiological functions other than as an androgen precursor. The previous studies performed have demonstrated a number of biological effects in rodents, such as amelioration of disease in diabetic, chemical carcinogenesis, and obesity models. To date, activation of the peroxisome proliferators activated receptor alpha, pregnane X receptor, and estrogen receptor by DHEA and its metabolites have been demonstrated. Several membrane-associated receptors have also been elucidated leading to additional mechanisms by which DHEA may exert its biological effects. This review will provide an overview of the receptor multiplicity involved in the biological activity of this sterol. PMID:16684650

  13. Measuring fracture toughness in biological materials.

    PubMed

    Taylor, David

    2017-07-05

    Many biological materials fail by cracking. Examples are bone fractures, contact damage in eggs, splits in bamboo culm and defects in cartilage. The mechanical property that best describes failure by cracking is fracture toughness, which quantifies the ease with which cracks propagate and defines a material's tolerance for pre-existing cracks and other stress concentrating features. The measurement of fracture toughness presents some challenges, especially for biological materials. To obtain valid results requires care and, in many cases, considerable ingenuity to design an appropriate specimen and test protocol. Common mistakes include incorrect interpretation of the mechanics of loading in unusual specimen designs, and failures occurring at the material's ultimate tensile strength as a result of specimens or cracks being too small. Interpretation of the resulting toughness data may also present challenges, for example when R-curve behaviour is present. In this article, examples of good and bad practice are described, and some recommendations made. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Biological reference materials for extracellular vesicle studies.

    PubMed

    Valkonen, S; van der Pol, E; Böing, A; Yuana, Y; Yliperttula, M; Nieuwland, R; Laitinen, S; Siljander, P R M

    2017-02-15

    Extracellular vesicles (EVs) mediate normal physiological homeostasis and pathological processes by facilitating intercellular communication. Research of EVs in basic science and clinical settings requires both methodological standardization and development of reference materials (RM). Here, we show insights and results of biological RM development for EV studies. We used a three-step approach to find and develop a biological RM. First, a literature search was done to find candidates for biological RMs. Second, a questionnaire was sent to EV researchers querying the preferences for RM and their use. Third, a biological RM was selected, developed, characterized, and evaluated. The responses to the survey demonstrated a clear and recognized need for RM optimized for the calibration of EV measurements. Based on the literature, naturally occurring and produced biological RM, such as virus particles and liposomes, were proposed as RM. However, none of these candidate RMs have properties completely matching those of EVs, such as size and refractive index distribution. Therefore, we evaluated the use of nanoerythrosomes (NanoE), vesicles produced from erythrocytes, as a potential biological RM. The strength of NanoE is their resemblance to EVs. Compared to the erythrocyte-derived EVs (eryEVs), NanoE have similar morphology, a similar refractive index (1.37), larger diameter (70% of the NanoE are over 200nm), and increased positive staining for CD235a and lipids (Di-8-ANEPPS) (58% and 67% in NanoE vs. 21% and 45% in eryEVs, respectively). Altogether, our results highlight the general need to develop and validate new RM with similar physical and biochemical properties as EVs to standardize EV measurements between instruments and laboratories. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Nanobiotechnology: synthetic biology meets materials science.

    PubMed

    Jewett, Michael C; Patolsky, Fernando

    2013-08-01

    Nanotechnology, the area of science focused on the control of matter in the nanometer scale, allows ground-breaking changes of the fundamental properties of matter that are often radically different compared to those exhibited by the bulk counterparts. In view of the fact that dimensionality plays a key role in determining the qualities of matter, the realization of the great potential of nanotechnology has opened the door to other disciplines such as life sciences and medicine, where the merging between them offers exciting new applications, along with basic science research. The application of nanotechnology in life sciences, nanobiotechnology, is now having a profound impact on biological circuit design, bioproduction systems, synthetic biology, medical diagnostics, disease therapy and drug delivery. This special issue is dedicated to the overview of how we are learning to control biopolymers and biological machines at the molecular- and nanoscale. In addition, it covers far-reaching progress in the design and synthesis of nanoscale materials, thus enabling the construction of integrated systems in which the component blocks are comparable in size to the chemical and biological entities under investigation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Regulatory considerations for raw materials used in biological products.

    PubMed

    Khan, A S

    2010-01-01

    Raw materials are critical components of product manufacture; these include source materials such as cell substrates, tissues, and biological fluids required for product manufacture, as well as biological materials required for cell growth, propagation, differentiation, and selection. Adventitious viruses are a major safety concern in biological raw materials. This paper discusses the specific concerns related to different types of biological materials and presents the Center for Biologics Evaluation and Research's perspective on the qualification and management of raw materials for purposes of developing a safety program for the manufacture of biological products.

  17. Mechanical properties of nanostructure of biological materials

    NASA Astrophysics Data System (ADS)

    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.

  18. A (selective) history of Australian involvement in cytokine biology.

    PubMed

    Nicola, Nicos A

    2013-06-01

    This review focuses on contributions to cytokine biology made by Australians in Australia. It is clearly biased by my own experiences and selective recollections especially related to the colony-stimulating factors in which Australian involvement has been pre-eminent from discovery to clinical use. Nevertheless Australian scientists have also made profound contributions to other areas of cytokine and growth factor biology (including interferons, inflammatory cytokines, chemokines and epidermal, insulin-like and vascular endothelial growth factors) that are briefly described in this review as well as other chapters in this volume. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Cells and materials involved in guided tissue regeneration.

    PubMed

    O'Neal, R; Wang, H L; MacNeil, R L; Somerman, M J

    1994-01-01

    Just over 10 years ago a group of imaginative periodontal researchers reported that tissues lost to the destructive mechanisms of inflammatory periodontal disease could be regenerated either in part or whole by the use of a surgical technique that would become universally known as guided tissue regeneration. Since then, tremendous progress has been made in adapting these early research principles into a clinical treatment modality that is now recognized as a viable component of contemporary periodontal therapy. However, many questions remain as to the mechanisms involved in regenerative tissue formation and how to design surgical procedures and materials to best harness the regenerative capacities of the periodontium. This article reviews current concepts and controversies regarding the biologic basis of periodontal regeneration and biomaterials used in guided tissue regeneration therapy. Pros and cons related to regenerative techniques currently in use are discussed along with future directions in the field of periodontal regeneration.

  20. Issues Involving Infrared Detector Material Systems

    DTIC Science & Technology

    2006-09-28

    on the ferroelectric properties of thin film ferroelectric (211) Si substrate 1 1 1 1 Area 2 CdTe SiOx (211) Si substrate (110) direction 7 PZT...to develop textured template for growth of epitaxial thin film ferroelectric (TFFE) IR detectors on polyimide coated Si. The commercial TFFE has a...due to limitation of characterization capability on small sample spot on our ARL collaborator side. This project also involved a strong educational

  1. Low gravity on earth by magnetic levitation of biological material.

    PubMed

    Valles, James M; Guevorkian, Karine

    2002-07-01

    The use of a magnetic field gradient levitation apparatus as a tool for investigating gravisensing mechanisms in biological systems and as a low gravity simulator for biological systems is described. The basic principles are described. Differences between its application to pure materials and the heterogeneous materials of biological materials are emphasized.

  2. Curriculum and course materials for a forensic DNA biology course.

    PubMed

    Elkins, Kelly M

    2014-01-01

    The Forensic Science Education Programs Accreditation Commission (FEPAC) requires accredited programs offer a "coherent curriculum" to ensure each student gains a "thorough grounding of the natural…sciences." Part of this curriculum includes completion of a minimum of 15 semester-hours forensic science coursework, nine of which can involve a class in forensic DNA biology. Departments that have obtained or are pursuing FEPAC accreditation can meet this requirement by offering a stand-alone forensic DNA biology course; however, materials necessary to instruct students are often homegrown and not standardized; in addition, until recently, the community lacked commercially available books, lab manuals, and teaching materials, and many of the best pedagogical resources were scattered across various peer-reviewed journals. The curriculum discussed below is an attempt to synthesize this disparate information, and although certainly not the only acceptable methodology, the below discussion represents "a way" for synthesizing and aggregating this information into a cohesive, comprehensive whole.

  3. Solid freeform fabrication of biological materials

    NASA Astrophysics Data System (ADS)

    Wang, Jiwen

    This thesis investigates solid freeform fabrication of biological materials for dental restoration and orthopedic implant applications. The basic approach in this study for solid freeform fabrication of biological materials is micro-extrusion of single or multiple slurries for 3D components and inkjet color printing of multiple suspensions for functionally graded materials (FGMs). Common issues associated with micro-extrusion and inkjet color printing are investigated. These common issues include (i) formulation of stable slurries with a pseudoplastic property, (ii) cross-sectional geometry of the extrudate as a function of the extrusion parameters, (iii) fabrication path optimization for extrusion process, (iv) extrusion optimization for multi-layer components, (v) composition control in functionally graded materials, and (vi) sintering optimization to convert the freeform fabricated powder compact to a dense body for biological applications. The present study clearly shows that the rheological and extrusion behavior of dental porcelain slurries depend strongly on the pH value of the slurry and extrusion conditions. A slurry with pseudoplastic properties is a basic requirement for obtaining extruded lines with rectangular cross-sections. The cross-sectional geometry of the extrudate is also strongly affected by extrusion parameters including the extrusion nozzle height, nozzle moving speed, extrusion rate, and critical nozzle height. Proper combinations of these extrusion parameters are necessary in order to obtain single line extrudates with near rectangular cross-sections and 3D objects with dimensional accuracy, uniform wall thickness, good wall uprightness, and no wall slumping. Based on these understandings, single-wall, multi-wall, and solid teeth have been fabricated via micro-extrusion of the dental slurry directly from a CAD digital model in 30 min. Inkjet color printing using stable Al2O3 and ZrO 2 aqueous suspensions has been developed to fabricate

  4. Determination of total choline in biological materials.

    PubMed

    Lied, E; Braekkan, O R

    1975-01-01

    A microbiological eight-point parallel line assay for the determination of choline has been developed, using Neurospora crassa cholineless-1 as test organism. In the common procedure the mold is grown at 25 degrees C in 25 ml basal medium at pH 5.9-6.0. Growth studies showed, however, that a better log dose-response curve, with respect to the linear part of the curve, was obtained when the organism was grown at 30 degrees C, in 20 ml experimental volume and at pH 5.5. The proprosed eight-point assay was tested by comparison with the common procedure. Although repeated analyses of a test solution showed no significant difference in the mean values obtained, a greater scatter of the single values about the mean was observed when analyzing according to the common procedure. The developed procedure was also applied to different samples of biological material. The analysis of variance proved the parallelity and linearity of the dose-response curves. As a result of the variation between the replicates could be used as the experimental error of the assay when the confidence limits of the samples were computed.

  5. Programmable temperature control system for biological materials

    NASA Technical Reports Server (NTRS)

    Anselmo, V. J.; Harrison, R. G.; Rinfret, A. P.

    1982-01-01

    A system was constructed which allows programmable temperature-time control for a 5 cu cm sample volume of arbitrary biological material. The system also measures the parameters necessary for the determination of the sample volume specific heat and thermal conductivity as a function of temperature, and provides a detailed measurement of the temperature during phase change and a means of calculating the heat of the phase change. Steady-state and dynamic temperature control is obtained by supplying heat to the sample volume through resistive elements constructed as an integral part of the sample container. For cooling purposes, this container is totally immersed into a cold heat sink. Using a mixture of dry ice and alcohol at 79 C, the sample volume can be controlled from +40 to -60 C at rates from steady state to + or - 65 C/min. Steady-state temperature precision is better than 0.2 C, while the dynamic capability depends on the temperature rate of change as well as the mass of both the sample and the container.

  6. Pharmacist participation in the management of incidents involving hazardous materials.

    PubMed

    Levy, D B; Barone, J A; Raia, J J; York, J M; Vogel, D P

    1987-03-01

    The role of the pharmacist as a hazardous materials consultant is described. Pharmacists in a university-affiliated teaching hospital are contacted by either emergency medical services or the emergency department to assist in the management of incidents involving toxic hazardous materials. These incidents can range from major chemical spills or leaks to long-term exposures involving generalized, nonspecific symptoms. An advanced pharmacy resident in emergency medicine is the primary pharmacy contact for hazardous materials consults. The services provided by the clinical pharmacist include identification of the hazardous materials involved, initiation of special precautions for rescue-squad and hospital-based personnel, clinical assessment of the toxicologic problem, and formulation of therapeutic recommendations. Teaching programs have been developed for pharmacy, nursing, and medical students, hospital employees, and emergency-response agencies. Pharmacy participation in the management of hazardous materials incidents has been well received by emergency department physicians and nurses, as well as by rescue personnel. During the period between January 1 and July 1, 1986, the pharmacy was consulted on 66 hazardous materials incidents. Since pharmacists have traditionally been used as information resources for clinical toxicology questions, it follows that their participation can extend into the field of environmental toxicology, specifically involving hazardous materials. The pharmacist's input as a hazardous materials consultant in our institution has been well received, and we believe that pharmacy departments can play an important role in the management of incidents involving hazardous materials.

  7. Method and apparatus for biological material separation

    DOEpatents

    Robinson, Donna L.

    2005-05-10

    There has been invented an apparatus comprising a separation barrier for excluding denser cell materials from less dense cell materials after centrifuging of the cells so that selected materials can be withdrawn from the less dense cell materials without inclusion of the denser cell materials or clogging of sampling equipment with denser cell materials. Cells from which selected material is to be withdrawn are centrifuged, either as cells or cells in media. Once the denser cell materials are isolated in a layer by centrifugal force, an invention screen or seive is submerged in the less dense cell material to a level above the layer of denser cell materials to isolate the denser cell materials from the less dense cell materials, preventing mixing of the denser cell materials back into the less dense cell materials when the cells or the cells in media are no longer being centrifuged and to prevent clogging of sampling equipment with denser cell materials. In a particularly useful application of the invention method and apparatus, plasmid DNA can be withdrawn from less dense cell materials without contamination or interference with denser cell materials.

  8. Mechanisms of and facility types involved in hazardous materials incidents.

    PubMed Central

    Kales, S N; Polyhronopoulos, G N; Castro, M J; Goldman, R H; Christiani, D C

    1997-01-01

    The purpose of this study was to systematically investigate hazardous materials (hazmat) releases and determine the mechanisms of these accidents, and the industries/activities and chemicals involved. We analyzed responses by Massachusetts' six district hazmat teams from their inception through May 1996. Information from incident reports was extracted onto standard coding sheets. The majority of hazardous materials incidents were caused by spills, leaks, or escapes of hazardous materials (76%) and occurred at fixed facilities (80%). Transportation-related accidents accounted for 20% of incidents. Eleven percent of hazardous materials incidents were at schools or health care facilities. Petroleum-derived fuels were involved in over half of transportation-related accidents, and these accounted for the majority of petroleum fuel releases. Chlorine derivatives were involved in 18% of all accidents and were associated with a wide variety of facility types and activities. In conclusion, systematic study of hazardous materials incidents allows the identification of preventable causes of these incidents. PMID:9300926

  9. [Synthetic biology and rearrangements of microbial genetic material].

    PubMed

    Liang, Quan-Feng; Wang, Qian; Qi, Qing-Sheng

    2011-10-01

    As an emerging discipline, synthetic biology has shown great scientific values and application prospects. Although there have been many reviews of various aspects on synthetic biology over the last years, this article, for the first time, attempted to discuss the relationship and difference between microbial genetics and synthetic biology. We summarized the recent development of synthetic biology in rearranging microbial genetic materials, including synthesis, design and reduction of genetic materials, standardization of genetic parts and modularization of genetic circuits. The relationship between synthetic biology and microbial genetic engineering was also discussed in the paper.

  10. Multifunctional integration: from biological to bio-inspired materials.

    PubMed

    Liu, Kesong; Jiang, Lei

    2011-09-27

    Nature is a school for human beings. Learning from nature has long been a source of bioinspiration for scientists and engineers. Multiscale structures are characteristic for biological materials, exhibiting inherent multifunctional integration. Optimized biological solutions provide inspiration for scientists and engineers to design and to fabricate multiscale structured materials for multifunctional integration. © 2011 American Chemical Society

  11. Reversibly immobilized biological materials in monolayer films on electrodes

    DOEpatents

    Weaver, P.F.; Frank, A.J.

    1993-05-04

    Methods and techniques are described for reversibly binding charged biological particles in a fluid medium to an electrode surface. The methods are useful in a variety of applications. The biological materials may include microbes, proteins, and viruses. The electrode surface may consist of reversibly electroactive materials such as polyvinylferrocene, silicon-linked ferrocene or quinone.

  12. Reversibly immobilized biological materials in monolayer films on electrodes

    DOEpatents

    Weaver, Paul F.; Frank, Arthur J.

    1993-01-01

    Methods and techniques are described for reversibly binding charged biological particles in a fluid medium to an electrode surface. The methods are useful in a variety of applications. The biological materials may include microbes, proteins, and viruses. The electrode surface may consist of reversibly electroactive materials such as polyvinylferrocene, silicon-linked ferrocene or quinone.

  13. Cell and molecular mechanics of biological materials

    NASA Astrophysics Data System (ADS)

    Bao, G.; Suresh, S.

    2003-11-01

    Living cells can sense mechanical forces and convert them into biological responses. Similarly, biological and biochemical signals are known to influence the abilities of cells to sense, generate and bear mechanical forces. Studies into the mechanics of single cells, subcellular components and biological molecules have rapidly evolved during the past decade with significant implications for biotechnology and human health. This progress has been facilitated by new capabilities for measuring forces and displacements with piconewton and nanometre resolutions, respectively, and by improvements in bio-imaging. Details of mechanical, chemical and biological interactions in cells remain elusive. However, the mechanical deformation of proteins and nucleic acids may provide key insights for understanding the changes in cellular structure, response and function under force, and offer new opportunities for the diagnosis and treatment of disease. This review discusses some basic features of the deformation of single cells and biomolecules, and examines opportunities for further research.

  14. Transportation accidents/incidents involving radioactive materials (1971--1991)

    SciTech Connect

    Cashwell, C. E.; McClure, J. D.

    1992-01-01

    The Radioactive Materials Incident Report (RMIR) database contains information on transportation-related accidents and incidents involving radioactive materials that have occurred in the United States. The RMIR was developed at Sandia National Laboratories (SNL) to support its research and development program efforts for the US Department of Energy (DOE). This paper will address the following topics: background information on the regulations and process for reporting a hazardous materials transportation incident, overview data of radioactive materials transportation accidents and incidents, and additional information and summary data on how packagings have performed in accident conditions.

  15. Materiomics: biological protein materials, from nano to macro.

    PubMed

    Cranford, Steven; Buehler, Markus J

    2010-11-12

    Materiomics is an emerging field of science that provides a basis for multiscale material system characterization, inspired in part by natural, for example, protein-based materials. Here we outline the scope and explain the motivation of the field of materiomics, as well as demonstrate the benefits of a materiomic approach in the understanding of biological and natural materials as well as in the design of de novo materials. We discuss recent studies that exemplify the impact of materiomics - discovering Nature's complexity through a materials science approach that merges concepts of material and structure throughout all scales and incorporates feedback loops that facilitate sensing and resulting structural changes at multiple scales. The development and application of materiomics is illustrated for the specific case of protein-based materials, which constitute the building blocks of a variety of biological systems such as tendon, bone, skin, spider silk, cells, and tissue, as well as natural composite material systems (a combination of protein-based and inorganic constituents) such as nacre and mollusk shells, and other natural multiscale systems such as cellulose-based plant and wood materials. An important trait of these materials is that they display distinctive hierarchical structures across multiple scales, where molecular details are exhibited in macroscale mechanical responses. Protein materials are intriguing examples of materials that balance multiple tasks, representing some of the most sustainable material solutions that integrate structure and function despite severe limitations in the quality and quantity of material building blocks. However, up until now, our attempts to analyze and replicate Nature's materials have been hindered by our lack of fundamental understanding of these materials' intricate hierarchical structures, scale-bridging mechanisms, and complex material components that bestow protein-based materials their unique properties. Recent

  16. Management of Biological Materials in Wastewater from Research & Development Facilities

    SciTech Connect

    Raney, Elizabeth A.; Moon, Thomas W.; Ballinger, Marcel Y.

    2011-04-01

    PNNL has developed and instituted a systematic approach to managing work with biological material that begins in the project planning phase and carries through implementation to waste disposal. This paper describes two major processes used at PNNL to analyze and mitigate the hazards associated with working with biological materials and evaluate them for disposal to the sewer, ground, or surface water in a manner that protects human health and the environment. The first of these processes is the Biological Work Permit which is used to identify requirements for handling, storing, and working with biological materials and the second is the Sewer Approval process which is used to evaluate discharges of wastewaters containing biological materials to assure they meet industrial wastewater permits and other environmental regulations and requirements.

  17. Materiomics: biological protein materials, from nano to macro

    PubMed Central

    Cranford, Steven; Buehler, Markus J

    2010-01-01

    Materiomics is an emerging field of science that provides a basis for multiscale material system characterization, inspired in part by natural, for example, protein-based materials. Here we outline the scope and explain the motivation of the field of materiomics, as well as demonstrate the benefits of a materiomic approach in the understanding of biological and natural materials as well as in the design of de novo materials. We discuss recent studies that exemplify the impact of materiomics – discovering Nature’s complexity through a materials science approach that merges concepts of material and structure throughout all scales and incorporates feedback loops that facilitate sensing and resulting structural changes at multiple scales. The development and application of materiomics is illustrated for the specific case of protein-based materials, which constitute the building blocks of a variety of biological systems such as tendon, bone, skin, spider silk, cells, and tissue, as well as natural composite material systems (a combination of protein-based and inorganic constituents) such as nacre and mollusk shells, and other natural multiscale systems such as cellulose-based plant and wood materials. An important trait of these materials is that they display distinctive hierarchical structures across multiple scales, where molecular details are exhibited in macroscale mechanical responses. Protein materials are intriguing examples of materials that balance multiple tasks, representing some of the most sustainable material solutions that integrate structure and function despite severe limitations in the quality and quantity of material building blocks. However, up until now, our attempts to analyze and replicate Nature’s materials have been hindered by our lack of fundamental understanding of these materials’ intricate hierarchical structures, scale-bridging mechanisms, and complex material components that bestow protein-based materials their unique properties

  18. New insights and perspectives into biological materials for flexible electronics.

    PubMed

    Wang, Lili; Chen, Di; Jiang, Kai; Shen, Guozhen

    2017-09-06

    Biological materials have robust hierarchical structures capable of specialized functions and the incorporation of natural biologically active components, which have been finely tuned through millions of years of evolution. These highly efficient architectural designs afford remarkable transport and mechanical properties, which render them attractive candidates for flexible electronic sensing technologies. This review provides a comprehensive overview of the fundamental aspects and applications of biological materials for flexible electronic devices and discusses various classes of biological materials by describing their unique structures and functions. We discuss the effect of the biological activity of biological materials on the improved properties in detail, because this effect overcomes the limited bioavailability and restricted morphology of materials generally encountered in traditional flexible electronic devices. We also summarize various approaches for the design and functionalization of natural materials and their applications in flexible electronic devices for use in biomedical, electron, energy, environmental and optical fields. Finally, we provide new insights and perspectives to further describe trends for future generations of biological materials, which are likely to be critical components (building blocks or elements) in future flexible electronics.

  19. The effect of material hardship on child protective service involvement.

    PubMed

    Yang, Mi-Youn

    2015-03-01

    This study employs four waves of survey data on 1,135 families from the Illinois Families Study, a longitudinal panel study of Temporary Assistance for Needy Families in Illinois. This study explores the following issues within this low-income population: (1) whether material hardships are associated with child protective services (CPS) investigations, (2) whether the effect of material hardship on CPS differs by the type of child maltreatment investigated, and (3) whether psychological distress mediates the association between material hardship and CPS involvement. Results from pooled and fixed effects logistic regressions suggest that caregivers who experience material hardship are more likely to become involved in CPS. In general, investigated neglect reports are responsive to particular types of hardship such as housing and food, while investigated physical abuse reports are responsive to levels of hardship regardless of specific types. The association between material hardship and CPS involvement is not fully explained by depressive symptoms or parenting stress. The study results suggest that in order to prevent child maltreatment, it may be necessary to address a family's unmet material needs through economic support interventions.

  20. Functionalized apertures for the detection of chemical and biological materials

    DOEpatents

    Letant, Sonia E.; van Buuren, Anthony W.; Terminello, Louis J.; Thelen, Michael P.; Hope-Weeks, Louisa J.; Hart, Bradley R.

    2010-12-14

    Disclosed are nanometer to micron scale functionalized apertures constructed on a substrate made of glass, carbon, semiconductors or polymeric materials that allow for the real time detection of biological materials or chemical moieties. Many apertures can exist on one substrate allowing for the simultaneous detection of numerous chemical and biological molecules. One embodiment features a macrocyclic ring attached to cross-linkers, wherein the macrocyclic ring has a biological or chemical probe extending through the aperture. Another embodiment achieves functionalization by attaching chemical or biological anchors directly to the walls of the apertures via cross-linkers.

  1. Mathematical and numerical challenges in living biological materials

    NASA Astrophysics Data System (ADS)

    Forest, M. Gregory; Vasquez, Paula A.

    2013-10-01

    The proclaimed Century of Biology is rapidly leading to the realization of how starkly different and more complex biological materials are than the materials that underpinned the industrial and technological revolution. These differences arise, in part, because biological matter exhibits both viscous and elastic behavior. Moreover, this behavior varies across the frequency, wavelength and amplitude spectrum of forcing. This broadclass of responsesin biological matter requires multiple frequency-dependent functions to specify material behavior, instead of a discrete set of parameters that relate to either viscosity or elasticity. This complexity prevails even if the biological matter is assumed to be spatially homogeneous, which is rarely true. However, very little progress has been made on the characterization of heterogeneity and how to build that information into constitutive laws and predictive models. In addition, most biological matter is non-stationary, which motivates the term "living". Biomaterials typically are in an active state in order to perform certain functions, and they often are modified or replenished on the basis of external stimuli. It has become popular in materials engineering to try to duplicate some of the functionality of biomaterials, e.g., a lot of effort has gone into the design of self-assembling, self-healing and shape shifting materials. These distinguishing features of biomaterials require significantly more degrees of freedom than traditional composites and many of the molecular species and their roles in functionality have yet to be determined. A typical biological material includes small molecule biochemical species that react and diffuse within larger species. These large molecular weightspecies provide the primary structural and biophysical properties of the material. The small molecule binding and unbinding kinetics serves to modulate material properties, and typical small molecule production and release are governed by

  2. Material science lesson from the biological photosystem

    NASA Astrophysics Data System (ADS)

    Kim, Younghye; Lee, Jun Ho; Ha, Heonjin; Im, Sang Won; Nam, Ki Tae

    2016-08-01

    Inspired by photosynthesis, artificial systems for a sustainable energy supply are being designed. Each sequential energy conversion process from light to biomass in natural photosynthesis is a valuable model for an energy collection, transport and conversion system. Notwithstanding the numerous lessons of nature that provide inspiration for new developments, the features of natural photosynthesis need to be reengineered to meet man's demands. This review describes recent strategies toward adapting key lessons from natural photosynthesis to artificial systems. We focus on the underlying material science in photosynthesis that combines photosystems as pivotal functional materials and a range of materials into an integrated system. Finally, a perspective on the future development of photosynthesis mimetic energy systems is proposed.

  3. Nature or petrochemistry?-biologically degradable materials.

    PubMed

    Mecking, Stefan

    2004-02-20

    Naturally occurring polymers have been utilized for a long time as materials, however, their application as plastics has been restricted because of their limited thermoplastic processability. Recently, the microbial synthesis of polyesters directly from carbohydrate sources has attracted considerable attention. The industrial-scale production of poly(lactic acid) from lactic acid generated by fermentation now provides a renewable resources-based polyester as a commodity plastic for the first time. The biodegradability of a given material is independent of its origin, and biodegradable plastics can equally well be prepared from fossil fuel feedstocks. A consideration of the overall carbon dioxide emissions and consumption of non-renewable resources over the entire life-cycle of a product is not necessarily favorable for plastics based on renewable resources with current technology-in addition to the feedstocks for the synthesis of the polymer materials, the feedstock for generation of the overall energy required for production and processing is decisive.

  4. Material science lesson from the biological photosystem.

    PubMed

    Kim, Younghye; Lee, Jun Ho; Ha, Heonjin; Im, Sang Won; Nam, Ki Tae

    2016-01-01

    Inspired by photosynthesis, artificial systems for a sustainable energy supply are being designed. Each sequential energy conversion process from light to biomass in natural photosynthesis is a valuable model for an energy collection, transport and conversion system. Notwithstanding the numerous lessons of nature that provide inspiration for new developments, the features of natural photosynthesis need to be reengineered to meet man's demands. This review describes recent strategies toward adapting key lessons from natural photosynthesis to artificial systems. We focus on the underlying material science in photosynthesis that combines photosystems as pivotal functional materials and a range of materials into an integrated system. Finally, a perspective on the future development of photosynthesis mimetic energy systems is proposed.

  5. Inactivation of Aerosolized Biological Agents using Filled Nanocomposite Materials

    DTIC Science & Technology

    2013-02-01

    Determination of Biological Contaminants in Environmental Samples. AIHA - American Industrial Hygiene Association. 2nd Edn. (Eds.) AIHA, Fairfax...DTRA-TR-12-72 Inactivation of Aerosolized Biological Agents using Filled Nanocomposite Materials Approved for public release, distribution is...Standard Form 298 (Re . 8-98) v Prescribed by ANSI Std. Z39.18 00-02-2013 Technical 01/28/2008 - 08/07/2011 Inactivation of Aerosolized Biological

  6. Survey of techniques used to preserve biological materials

    NASA Technical Reports Server (NTRS)

    Feinler, E. J.; Hubbard, R. W.

    1972-01-01

    The techniques used to preserve biological materials are documented and summarized. The report is presented in a handbook format that categorizes the most important preservation techniques available, and includes a representative sampling of the thousands of applications of these techniques to biological materials and organisms. Details of the information coverage and method of approach are outlined. Data are given in tabular form, and an index and extensive bibliography are included.

  7. Analytical Chemistry at the Interface Between Materials Science and Biology

    SciTech Connect

    O'Brien, Janese C.

    2000-09-21

    Likedlessentid sciences, anal~cd chetis~continues toreinvent itself. Moving beyond its traditional roles of identification and quantification, analytical chemistry is now expanding its frontiers into areas previously reserved to other disciplines. This work describes several research efforts that lie at the new interfaces between analytical chemistry and two of these disciplines, namely materials science and biology. In the materials science realm, the search for new materials that may have useful or unique chromatographic properties motivated the synthesis and characterization of electrically conductive sol-gels. In the biology realm, the search for new surface fabrication schemes that would permit or even improve the detection of specific biological reactions motivated the design of miniaturized biological arrays. Collectively, this work represents some of analytical chemistry’s newest forays into these disciplines. The introduction section to this dissertation provides a literature review on several of the key aspects of this work. In advance of the materials science discussion, a brief introduction into electrochemically-modulated liquid chromatography (EMLC) and sol-gel chemistry is provided. In advance of the biological discussions, brief overviews of scanning force microscopy (SFM) and the oxidative chemistry used to construct our biological arrays are provided. This section is followed by four chapters, each of which is presented as a separate manuscript, and focuses on work that describes some of our cross-disciplinary efforts within materials science and biology. This dissertation concludes with a general summary and future prospectus.

  8. Kinetic determination of selenium in biological material

    SciTech Connect

    Efremenko, O.A.; Krasnyuk, I.I.; Kudrin, A.N.; Rudenko, B.A.

    1986-05-10

    A very promising method for selenium determination is a kinetic analytical procedure that combines the simplicity and availability of physical instrumentation with a low analyte detection limit. This paper reports a modification of the method to enable the determination of selenium in rat blood and involves decomposing the sample with a mixture of nitric and perchloric acids, separation of the selenium (IV) from other decomposition products, and quantitatively determining selenium by the described kinetic method using the indicator reaction of iron (II) edetate oxidation by sodium nitrate.

  9. Millimeter wave and terahertz dielectric properties of biological materials

    NASA Astrophysics Data System (ADS)

    Khan, Usman Ansar

    Broadband dielectric properties of materials can be employed to identify, detect, and characterize materials through their unique spectral signatures. In this study, millimeter wave, submillimeter wave, and terahertz dielectric properties of biological substances inclusive of liquids, solids, and powders were obtained using Dispersive Fourier Transform Spectroscopy (DFTS). Two broadband polarizing interferometers were constructed to test materials from 60 GHz to 1.2 THz. This is an extremely difficult portion of the frequency spectrum to obtain a material's dielectric properties since neither optical nor microwave-based techniques provide accurate data. The dielectric characteristics of liquids such as cyclohexane, chlorobenzene, benzene, ethanol, methanol, 1,4 dioxane, and 10% formalin were obtained using the liquid interferometer. Subsequently the solid interferometer was utilized to determine the dielectric properties of human breast tissues, which are fixed and preserved in 10% formalin. This joint collaboration with the Tufts New England Medical Center demonstrated a significant difference between the dielectric response of tumorous and non-tumorous breast tissues across the spectrum. Powders such as anthrax, flour, talc, corn starch, dry milk, and baking soda have been involved in a number of security threats and false alarms around the globe in the last decade. To be able to differentiate hoax attacks and serious security threats, the dielectric properties of common household powders were also examined using the solid interferometer to identify the powders' unique resonance peaks. A new sample preparation kit was designed to test the powder specimens. It was anticipated that millimeter wave and terahertz dielectric characterization will enable one to clearly distinguish one powder from the other; however most of the powders had relatively close dielectric responses and only Talc had a resonance signature recorded at 1.135 THz. Furthermore, due to

  10. SOURCE MATERIALS FOR GENERAL AND HUMAN BIOLOGY. FINAL REPORT.

    ERIC Educational Resources Information Center

    HALL, THOMAS S.

    DEVELOPED AND SUBJECTIVELY EVALUATED ARE INSTRUCTIONAL MATERIALS FOR USE IN AN INTRODUCTORY COLLEGE LEVEL GENERAL EDUCATION BIOLOGY COURSE, WHICH EMPHASIZES THE DYNAMIC AND INVESTIGATIVE ASPECTS OF SCIENCE. THE MATERIALS, WHICH USE A CASE HISTORY APPROACH, WERE DEVELOPED BY EDITING EXCERPTS FROM CLASSICAL SCIENTIFIC PAPERS WITH ADEQUATE EDITORIAL…

  11. Packaging biological cargoes in mesoporous materials: opportunities for drug delivery.

    PubMed

    Siefker, Justin; Karande, Pankaj; Coppens, Marc-Olivier

    2014-11-01

    Confinement of biomolecules in structured nanoporous materials offers several desirable features ranging from chemical and thermal stability, to resistance to degradation from the external environment. A new generation of mesoporous materials presents exciting new possibilities for the formulation and controlled release of biological agents. Such materials address niche applications in enteral and parenteral delivery of biologics, such as peptides, polypeptides, enzymes and proteins for use as therapeutics, imaging agents, biosensors, and adjuvants. Mesoporous silica Santa Barbara Amorphous-15 (SBA-15), with its unique, tunable pore diameter, and easily functionalized surface, provides a representative example of this new generation of materials. Here, we review recent advances in the design and synthesis of nanostructured mesoporous materials, focusing on SBA-15, and highlight opportunities for the delivery of biological agents to various organ and tissue compartments. The SBA-15 platform provides a delivery carrier that is inherently separated from the active biologic due to distinct intra and extra-particle environments. This permits the SBA-15 platform to not require direct modification of the active biological therapeutic. Additionally, this makes the platform universal and allows for its application independent of the desired methods of discovery and development. The SBA-15 platform also directly addresses issues of targeted delivery and controlled release, although future challenges in the implementation of this platform reside in particle design, biocompatibility, and the tunability of the internal and external material properties. Examples illustrating the flexibility in the application of the SBA-15 platform are also discussed.

  12. Benefit evaluation of space processing of biological materials

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A rational analytical basis for the evaluation of potential benefits of space processing of biological materials is described. A preliminary evaluation of three candidate space processed biological materials was accomplished. Materials investigated were human lymphocytes, urokinase, and Beta cells. Separation of lymphocyte groups was considered in order to improve the matching of donors and recipients for kidney transplantation, while urokinase was examined in regard to treatment of thromboembolic diseases. Separation of Beta cells was studied since it could provide a highly effective means for the treatment of juvenile-onset diabetes.

  13. Mesoporous silicates: Materials science and biological applications

    NASA Astrophysics Data System (ADS)

    Roggers, Robert Anthony

    This thesis dissertation presents the collective research into the advancement of mesoporous silicate particles as biointerface devices, the development of new materials and the application of these particles as solid supports for heterogeneous catalysis. Mesoporous silica has been utilized in the aforementioned applications due to several reasons; the first being the ability to achieve high surface areas (500 - 1000 m2 g-1) with controlled pore sizes and particle morphology. Another reason for their popularity is their robustness in applications of heterogeneous catalysis and the ability to functionalize the surface with a wide variety of organic functional groups. In the field of biointerface devices, mesoporous silica nanoparticles represent a class of materials that exhibit high biocompatibility. In addition, the ability to functionalize the surfaces (outer surface and pore interiors) allows the particles to be targeted to specific cell types as well as the ability to release many different therapeutic molecules under specific stimuli. A unique particle coating consisting of a chemically cleavable lipid bilayer that allows for the encapsulation of a fluorescent molecule and increases the biocompatibility of the particle has been developed. The lipid bilayer coated mesoporous silica nanoparticle (LB-MSN) was characterized using X-ray diffraction, transmission electron microscopy and nitrogen `sorption isotherms. The finished LB-MSN was then incubated with mammalian cells in order to prove their biocompatibility. Confocal micrographs demonstrate the endocytosis of the particles into the cells. In addition the micrographs also show that the LB-MSNs are separate from the endosomal compartments, however due to the lipophilic nature of the dye used to label the endosome there is some debate regarding this conclusion. The lipid bilayer coating was then applied to a large pore MSN (l-MSN) which had been previously shown to cause lysis of red blood cells (RBCs) at low

  14. Materials and methods for delivery of biological drugs

    NASA Astrophysics Data System (ADS)

    Zelikin, Alexander N.; Ehrhardt, Carsten; Healy, Anne Marie

    2016-11-01

    Biological drugs generated via recombinant techniques are uniquely positioned due to their high potency and high selectivity of action. The major drawback of this class of therapeutics, however, is their poor stability upon oral administration and during subsequent circulation. As a result, biological drugs have very low bioavailability and short therapeutic half-lives. Fortunately, tools of chemistry and biotechnology have been developed into an elaborate arsenal, which can be applied to improve the pharmacokinetics of biological drugs. Depot-type release systems are available to achieve sustained release of drugs over time. Conjugation to synthetic or biological polymers affords long circulating formulations. Administration of biological drugs through non-parenteral routes shows excellent performance and the first products have reached the market. This Review presents the main accomplishments in this field and illustrates the materials and methods behind existing and upcoming successful formulations and delivery strategies for biological drugs.

  15. Using Spreadsheets to Teach Aspects of Biology Involving Mathematical Models

    ERIC Educational Resources Information Center

    Carlton, Kevin; Nicholls, Mike; Ponsonby, David

    2004-01-01

    Some aspects of biology, for example the Hardy-Weinberg simulation of population genetics or modelling heat flow in lizards, have an undeniable mathematical basis. Students can find the level of mathematical skill required to deal with such concepts to be an insurmountable hurdle to understanding. If not used effectively, spreadsheet models…

  16. Using Spreadsheets to Teach Aspects of Biology Involving Mathematical Models

    ERIC Educational Resources Information Center

    Carlton, Kevin; Nicholls, Mike; Ponsonby, David

    2004-01-01

    Some aspects of biology, for example the Hardy-Weinberg simulation of population genetics or modelling heat flow in lizards, have an undeniable mathematical basis. Students can find the level of mathematical skill required to deal with such concepts to be an insurmountable hurdle to understanding. If not used effectively, spreadsheet models…

  17. Structural Design Elements in Biological Materials: Application to Bioinspiration.

    PubMed

    Naleway, Steven E; Porter, Michael M; McKittrick, Joanna; Meyers, Marc A

    2015-10-07

    Eight structural elements in biological materials are identified as the most common amongst a variety of animal taxa. These are proposed as a new paradigm in the field of biological materials science as they can serve as a toolbox for rationalizing the complex mechanical behavior of structural biological materials and for systematizing the development of bioinspired designs for structural applications. They are employed to improve the mechanical properties, namely strength, wear resistance, stiffness, flexibility, fracture toughness, and energy absorption of different biological materials for a variety of functions (e.g., body support, joint movement, impact protection, weight reduction). The structural elements identified are: fibrous, helical, gradient, layered, tubular, cellular, suture, and overlapping. For each of the structural design elements, critical design parameters are presented along with constitutive equations with a focus on mechanical properties. Additionally, example organisms from varying biological classes are presented for each case to display the wide variety of environments where each of these elements is present. Examples of current bioinspired materials are also introduced for each element.

  18. Examples for biological reactivity involving free radicals followed by CIDNP

    NASA Astrophysics Data System (ADS)

    Andreu, Inmaculada; Neshchadin, Dmytro; Batchelor, Stephen N.; Miranda, Miguel A.; Gescheidt, Georg

    2013-10-01

    It is shown how chemically induced dynamic nuclear polarisation (CIDNP) spectroscopy is able to efficiently complement electron paramagnetic resonance (EPR), when molecular transformations of free radical pairs are investigated. This is demonstrated in three examples of modelling biologically relevant phenomena, particularly oxidative stress and antioxidant activity. Lipid peroxidation, topological control in the oxidation of cholesterol, and a mechanistic study of antioxidant activity of natural tea and wine polyphenols are presented.

  19. Materials Manufactured from 3D Printed Synthetic Biology Arrays

    NASA Technical Reports Server (NTRS)

    Gentry, Diana; Micks, Ashley

    2013-01-01

    Many complex, biologically-derived materials have extremely useful properties (think wood or silk), but are unsuitable for space-related applications due to production, manufacturing, or processing limitations. Large-scale ecosystem-based production, such as raising and harvesting trees for wood, is impractical in a self-contained habitat such as a space station or potential Mars colony. Manufacturing requirements, such as the specialized equipment needed to harvest and process cotton, add too much upmass for current launch technology. Cells in nature are already highly specialized for making complex biological materials on a micro scale. We envision combining these strengths with the recently emergent technologies of synthetic biology and 3D printing to create 3D-structured arrays of cells that are bioengineered to secrete different materials in a specified three-dimensional pattern.

  20. Flexible Organic Electronics in Biology: Materials and Devices.

    PubMed

    Liao, Caizhi; Zhang, Meng; Yao, Mei Yu; Hua, Tao; Li, Li; Yan, Feng

    2015-12-09

    At the convergence of organic electronics and biology, organic bioelectronics attracts great scientific interest. The potential applications of organic semiconductors to reversibly transmit biological signals or stimulate biological tissues inspires many research groups to explore the use of organic electronics in biological systems. Considering the surfaces of movable living tissues being arbitrarily curved at physiological environments, the flexibility of organic bioelectronic devices is of paramount importance in enabling stable and reliable performances by improving the contact and interaction of the devices with biological systems. Significant advances in flexible organic bio-electronics have been achieved in the areas of flexible organic thin film transistors (OTFTs), polymer electrodes, smart textiles, organic electrochemical ion pumps (OEIPs), ion bipolar junction transistors (IBJTs) and chemiresistors. This review will firstly discuss the materials used in flexible organic bioelectronics, which is followed by an overview on various types of flexible organic bioelectronic devices. The versatility of flexible organic bioelectronics promises a bright future for this emerging area.

  1. XPS Analysis of Nanostructured Materials and Biological Surfaces

    SciTech Connect

    Baer, Donald R.; Engelhard, Mark H.

    2010-05-01

    This paper examines the types of information that XPS can provide about a variety of nano-structured materials. Although it is sometimes not considered a “nano-scale analysis method” XPS can provide a great deal of information about elemental distributions, layer or coating structure and thicknesses, surface functionality, and even particles sizes on the 1-20 nm scale for samples types that may not be readily analyzed by other methods. This information is important for both synthetic nanostructured or nanosized materials and a variety of natural materials with nanostructure. Although the links between nanostructure materials and biological systems may not at first be obvious, many biological molecules and some organisms are the sizes of nanoparticles. The nanostructure of cells and microbes plays a significant role in how they interact with their environment. The interaction of biomolecules with nanoparticles is important for medical and toxicity studies. The interaction of biomolecules is important for sensor function and many nanomaterials are now the active elements in sensors. This paper first discusses how nanostructures influences XPS data as part of understanding how simple models of sample structure and data analysis can be used to extract information about the physical and chemical structure of the materials being analyzed. Equally important, aspects of sample and analysis limitations and challenges associated with understanding nanostructured materials are indicated. Examples of the application of XPS to nanostructured and biological systems and materials are provided.

  2. Extinction and backscatter cross sections of biological materials

    NASA Astrophysics Data System (ADS)

    Thomas, M. E.; Hahn, D. V.; Carr, A. K.; Limsui, D.; Carter, C. C.; Boggs, N. T.; Jackman, J.

    2008-04-01

    Aerosol backscatter and extinction cross-sections are required to model and evaluate the performance of both active and passive detection systems. A method has been developed that begins with laboratory measurements of thin films and suspensions of biological material to obtain the complex index refraction of the biological material from the UV to the LWIR. Using that result with particle size distribution and shape information as inputs to T-matrix or discrete dipole approximation (DDA) calculations yields the extinction cross-section and backscatter cross section as a function of wavelength. These are important inputs to the lidar equation. In a continuing effort to provide validated optical cross-sections, measurements have been made on a number of high purity biological species in the laboratory as well as measurements of material released at recent field tests. The resulting observed differences between laboratory and field measurements aid in distinguishing between intrinsic and extrinsic effects, which can affect the characteristic signatures of important biological aerosols. A variety of biological and test aerosols are examined, including Bacillus atrophaeus (BG), and Erwina, ovalbumin, silica and polystyrene.

  3. Photoconversion of gasified organic materials into biologically-degradable plastics

    DOEpatents

    Weaver, P.F.; Pinching Maness.

    1993-10-05

    A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer. 3 figures.

  4. Photoconversion of gasified organic materials into biologically-degradable plastics

    DOEpatents

    Weaver, Paul F.; Maness, Pin-Ching

    1993-01-01

    A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer.

  5. Overview of light interaction with food and biological materials

    USDA-ARS?s Scientific Manuscript database

    This chapter presents the basic phenomena occurring during the interaction of light with biological and food materials, which form the foundation for different light scattering techniques that have been developed for property, quality and safety assessment of food and agricultural products. We first...

  6. Quantitation and detection of vanadium in biologic and pollution materials

    NASA Technical Reports Server (NTRS)

    Gordon, W. A.

    1974-01-01

    A review is presented of special considerations and methodology for determining vanadium in biological and air pollution materials. In addition to descriptions of specific analysis procedures, general sections are included on quantitation of analysis procedures, sample preparation, blanks, and methods of detection of vanadium. Most of the information presented is applicable to the determination of other trace elements in addition to vanadium.

  7. Theory of light transfer in food and biological materials

    USDA-ARS?s Scientific Manuscript database

    In this chapter, we first define the basic radiometric quantities that are needed for describing light propagation in food and biological materials. Radiative transfer theory is then derived, according to the principle of the conservation of energy. Because the radiative transfer theory equation is ...

  8. The determination of copper in biological materials by flame spectrophotometry

    PubMed Central

    Newman, G. E.; Ryan, M.

    1962-01-01

    A method for the determination of the copper content of biological materials by flame spectrophotometry is described. The effects of interference by ions such as sodium and phosphate were eliminated by isolating copper as the dithizonate in CCl4. Results obtained for the urinary excretion of copper by a patient with Wilson's disease before and after treatment with penicillamine are reported. PMID:14479334

  9. Reversibly immobilized biological materials in monolayer films on electrodes

    SciTech Connect

    Weaver, P.F.; Frank, A.J.

    1991-04-08

    A method is provided for reversibly binding charged biological particles in a fluid medium to an electrode surface. The method comprises treating (e.g., derivatizing) the electrode surface with an electrochemically active material; connecting the electrode to an electrical potential; and exposing the fluid medium to the electrode surface in a manner such that the charged particles become adsorbed on the electrode surface.

  10. Electron Microscopy of Biological Materials at the Nanometer Scale

    NASA Astrophysics Data System (ADS)

    Kourkoutis, Lena Fitting; Plitzko, Jürgen M.; Baumeister, Wolfgang

    2012-08-01

    Electron microscopy of biological matter uses three different imaging modalities: (a) electron crystallography, (b) single-particle analysis, and (c) electron tomography. Ideally, these imaging modalities are applied to frozen-hydrated samples to ensure an optimal preservation of the structures under scrutiny. Cryo-electron microscopy of biological matter has made important advances in the past decades. It has become a research tool that further expands the scope of structural research into unique areas of cell and molecular biology, and it could augment the materials research portfolio in the study of soft and hybrid materials. This review addresses how researchers using transmission electron microscopy can derive structural information at high spatial resolution from fully hydrated specimens, despite their sensitivity to ionizing radiation, despite the adverse conditions of high vacuum for samples that have to be kept in aqueous environments, and despite their low contrast resulting from weakly scattering building blocks.

  11. Instrument for noninvasive photonic assessments of biological materials

    NASA Astrophysics Data System (ADS)

    Fancy, Michael; Munger, Rejean; Fahim, Atef

    2004-10-01

    We have developed a new instrument for the non-invasive assessment of biological materials. The instrument assesses sample condition, by measuring the interaction of the biological material with optical radiation. The new instrument features efficient light collection optics, improved light delivery and increased measurement flexibility over previous designs. The optical properties measured are: refracted (transmitted), forward scattered, non-specularly reflected and specularly reflected light. Measurements were made for white light, as well as in several spectral regions over the visible spectrum. The instrument repeatability using non-biological controls was between 0.08% and 0.34% of maximum signal for each of the four optical properties for signals ranging from maximum to 0.1% maximum, for each of the wavelengths ranges. This repeatability is better than the variability of biological samples within a test group, which is 5% of maximum signal and ensures that the instrument will be able to accurately report the optical property of biological systems. The instrument is also capable of detecting changes of between 0.0063% and 0.0057% of maximum signal for each of the four optical properties and in each wavelength range. Using artificial, human, and porcine corneas, measurements were made to assess and quantify the system"s ability to characterize changes in the above optical properties in a biological system under stress. For both transmitted and reflected non-specular light, there was an equivalent correlation measured between artificial and human corneas, when exposed to an external insult. The instrument also proved effective in tracking time-dependant responses of biological tissues subjected to various insults. This new instrument is a reliable tool for measuring static and dynamic optical properties of various biological tissues. The ability to measure small relative changes in optical properties of tissues makes it an invaluable diagnostic tool.

  12. Structure and mechanics of interfaces in biological materials

    NASA Astrophysics Data System (ADS)

    Barthelat, Francois; Yin, Zhen; Buehler, Markus J.

    2016-04-01

    Hard biological materials — for example, seashells, bone or wood — fulfil critical structural functions and display unique and attractive combinations of stiffness, strength and toughness, owing to their intricate architectures, which are organized over several length scales. The size, shape and arrangement of the ‘building blocks’ of which these materials are made are essential for defining their properties and their exceptional performance, but there is growing evidence that their deformation and toughness are also largely governed by the interfaces that join these building blocks. These interfaces channel nonlinear deformations and deflect cracks into configurations in which propagation is more difficult. In this Review, we discuss comparatively the composition, structure and mechanics of a set of representative biological interfaces in nacre, bone and wood, and show that these interfaces possess unusual mechanical characteristics, which can encourage the development of advanced bioinspired composites. Finally, we highlight recent examples of synthetic materials inspired from the mechanics and architecture of natural interfaces.

  13. Aluminum analysis in biological reference material by nondestructive methods

    SciTech Connect

    Landsberger, S.; Arendt, A.; Keck, B.; Glascock, M.

    1988-01-01

    In recent years, the determination of aluminum in biological materials has become the subject of many research projects. This interest stems from an increasing knowledge of the toxicity of aluminum to both aquatic and human life. Unfortunately, the detection of aluminum in biological materials has proven troublesome. The use of traditional chemical determinations has been shown to be very long and somewhat complicated. Several attempts have been made using neutron activation analysis, but an interfering reaction must be taken into account. In this experiment the rabbit irradiation facilities at the University of Missouri Research Reactor were used. The aluminum concentrations for eight certified reference materials are shown. When US National Bureau of Standards (NBS) value is given as certified or as an information value, results agree very well. The results for NBS 1572 citrus leaves agree, and NBS 1577 results agree very well with that of Glascock et al.

  14. Biologically-Derived Photonic Materials for Thermal Protection Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Sylvia M.; Squire, Thomas H.; Lawson, John W.; Gusman, Michael; Lau, K.-H.; Sanjurjo, Angel

    2014-01-01

    Space vehicles entering a planetary atmosphere at high velocity can be subject to substantial radiative heating from the shock layer in addition to the convective heating caused by the flow of hot gas past the vehicle surface. The radiative component can be very high but of a short duration. Approaches to combat this effect include investigation of various materials to reflect the radiation. Photonic materials can be used to reflect radiation. The wavelengths reflected depend on the length scale of the ordered microstructure. Fabricating photonic structures, such as layers, can be time consuming and expensive. We have used a biologically-derived material as the template for forming a high temperature photonic material that could be incorporated into a heatshield thermal protection material.

  15. Digestion of titanium bearing geologic materials involving microwaves.

    PubMed

    Tripathi, Anju; Chattopadhyay, Partha

    2007-10-01

    An environmentally friendly and rapid digestion procedure involving 10 mL of acid mixture (HNO3 : HCl : HF = 2:2:1) for 0.1 g of sample in closed vessel microwave digester following heating program : 250W for 10 min., hold time 2 min., 600 W for 17 min, and Ventilation time 10 min was developed. The operating parameters were varied and optimized by factorial design approach using "Steepest Ascent" method. The validity of the recommended digestion procedure were examined by analyzing several well characterized standard reference materials such as diabase (W2), basalt (BIR-1, JB-3, BHVO-1), granite (G2), gabbro (JGb-1), Mn-nodule (Nod-A-1, Nod-P-1), sediment (STSD-4, LKSD-2), limestone (KH-2), soil (SAu-1), ilmenite (IGS-31), rutile (IGS-32), Zircon (IGS-35) and titanium dioxide (SRM-154b) employing both inductively coupled plasma-atomic emission spectrometry (ICP-AES) and well known spectrophotometric method. An excellent agreement between the methods and the certified values of standard reference materials suggest that the digestion procedure can be used for quality control and allied purposes.

  16. Health Physics Code System for Evaluating Accidents Involving Radioactive Materials.

    SciTech Connect

    2014-10-01

    Version 03 The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculational tool for evaluating accidents involving radioactive materials. HOTSPOT codes provide a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. The developer's website is: http://www.llnl.gov/nhi/hotspot/. Four general programs, PLUME, EXPLOSION, FIRE, and RESUSPENSION, calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosive release, fuel fire, or an area contamination event. Additional programs deal specifically with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. The FIDLER program can calibrate radiation survey instruments for ground survey measurements and initial screening of personnel for possible plutonium uptake in the lung. The HOTSPOT codes are fast, portable, easy to use, and fully documented in electronic help files. HOTSPOT supports color high resolution monitors and printers for concentration plots and contours. The codes have been extensively used by the DOS community since 1985. Tables and graphical output can be directed to the computer screen, printer, or a disk file. The graphical output consists of dose and ground contamination as a function of plume centerline downwind distance, and radiation dose and ground contamination contours. Users have the option of displaying scenario text on the plots. HOTSPOT 3.0.1 fixes three significant Windows 7 issues: Executable installed properly under "Program Files/HotSpot 3.0". Installation package now smaller: removed dependency on older Windows DLL files which previously needed to; Forms now properly scale based on DPI instead of font for users who change their screen resolution to something other than 100%. This is a more common feature in Windows 7; Windows installer

  17. INAA Application for Trace Element Determination in Biological Reference Material

    NASA Astrophysics Data System (ADS)

    Atmodjo, D. P. D.; Kurniawati, S.; Lestiani, D. D.; Adventini, N.

    2017-06-01

    Trace element determination in biological samples is often used in the study of health and toxicology. Determination change to its essentiality and toxicity of trace element require an accurate determination method, which implies that a good Quality Control (QC) procedure should be performed. In this study, QC for trace element determination in biological samples was applied by analyzing the Standard Reference Material (SRM) Bovine muscle 8414 NIST using Instrumental Neutron Activation Analysis (INAA). Three selected trace element such as Fe, Zn, and Se were determined. Accuracy of the elements showed as %recovery and precision as %coefficient of variance (%CV). The result showed that %recovery of Fe, Zn, and Se were in the range between 99.4-107%, 92.7-103%, and 91.9-112%, respectively, whereas %CV were 2.92, 3.70, and 5.37%, respectively. These results showed that INAA method is precise and accurate for trace element determination in biological matrices.

  18. Interfacial interactions involved in the biological assembly of Chandipura virus nucleocapsid protein.

    PubMed

    Sreejith, R; Gulati, Sahil; Gupta, Sanjay

    2013-06-01

    The biological assembly of Chandipura virus nucleocapsid (N) protein has been modeled and the amino acid residues involved in specific intermolecular interactions among N monomers during oligomerisation have been predicted.

  19. A review of evidence for biological material in meteorites.

    PubMed

    Urey, H C

    1966-01-01

    The first carbonaceous chondrite fell in France in 1806, and in the years following analyses for organic matter were made which showed this material to be similar to material of biological origin. But the analyses were not conclusive. Within the last few years, additional work has been done which has proved to be very interesting and somewhat controversial. The composition of the inorganic fraction of these objects is very similar to that of other meteorites, showing that no sorting by sedimentary processes has occurred. For this reason, students of meteorites have believed that the material could not be biological. However, the soluble constituents are similar to those to be expected in a primitive ocean of the earth. Some of the assumed fossils have been shown to be contaminants but others appear to be indigenous. After mineral matters are removed from them they still show evidence of containing carbonaceous material. Micro-paleontologists have also reported material which they believe to be similar to terrestrial fossils. Fatty acids, porphyrins, and nucleic acid bases have been reported and a small optical activity as well. The immense difficulty that students of meteorites have in understanding this situation may be alleviated if it should be proved that some of our stone meteorites, including the carbonaceous ones, are coming from the moon. There seems to be some possibility that this could be true.

  20. Biologically inspired autonomous structural materials with controlled toughening and healing

    NASA Astrophysics Data System (ADS)

    Garcia, Michael E.; Sodano, Henry A.

    2010-04-01

    The field of structural health monitoring (SHM) has made significant contributions in the field of prognosis and damage detection in the past decade. The advantageous use of this technology has not been integrated into operational structures to prevent damage from propagating or to heal injured regions under real time loading conditions. Rather, current systems relay this information to a central processor or human operator, who then determines a course of action such as altering the mission or scheduling repair maintenance. Biological systems exhibit advanced sensory and healing traits that can be applied to the design of material systems. For instance, bone is the major structural component in vertebrates; however, unlike modern structural materials, bone has many properties that make it effective for arresting the propagation of cracks and subsequent healing of the fractured area. The foremost goal for the development of future adaptive structures is to mimic biological systems, similar to bone, such that the material system can detect damage and deploy defensive traits to impede damage from propagating, thus preventing catastrophic failure while in operation. After sensing and stalling the propagation of damage, the structure must then be repaired autonomously using self healing mechanisms motivated by biological systems. Here a novel autonomous system is developed using shape memory polymers (SMPs), that employs an optical fiber network as both a damage detection sensor and a network to deliver stimulus to the damage site initiating adaptation and healing. In the presence of damage the fiber optic fractures allowing a high power laser diode to deposit a controlled level of thermal energy at the fractured sight locally reducing the modulus and blunting the crack tip, which significantly slows the crack growth rate. By applying a pre-induced strain field and utilizing the shape memory recovery effect, thermal energy can be deployed to close the crack and return

  1. Brazilian guidelines for biorepositories and biobanks of human biological material.

    PubMed

    Marodin, Gabriela; Salgueiro, Jennifer Braathen; Motta, Márcia da Luz; Santos, Leonor Maria Pacheco

    2013-01-01

    To characterize the participatory and democratic creation of the Brazilian guidelines for biorepositories and biobanks of human biological material with the purpose of research based on the ethical principles of human dignity, autonomy, beneficence, justice, and precaution. An interdisciplinary work group was constituted to prepare the document, considering the following criteria: experience in biobank operation, regional representation, type of stored biological material, and bioethics specialists. Members of the National Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA), also participated due to their regulatory competence. Members from the National Commission on Ethics in Research (Comissão Nacional de Ética em Pesquisa - Conep) participated as the social control organization. The document, based on ethical, legal, and technical guidelines, presents the concepts, activities, purposes, and differences between biorepositories and biobanks; forms of consent on the part of the subject; in addition to other aspects permeated by concerns regarding the appropriate use of information. The Brazilian guidelines for biorepository and biobank of human biological material with the purpose of research contains 39 articles, which are distributed in five chapters. The importance of legislation arises from the ethical concern, considering morals and taking into account the legal aspects, which translate into a document that does not end in itself. The dynamics of science always leads to changes in paradigms, which can go beyond the existing laws.

  2. Diffusion theory in biology: a relic of mechanistic materialism.

    PubMed

    Agutter, P S; Malone, P C; Wheatley, D N

    2000-01-01

    Diffusion theory explains in physical terms how materials move through a medium, e.g. water or a biological fluid. There are strong and widely acknowledged grounds for doubting the applicability of this theory in biology, although it continues to be accepted almost uncritically and taught as a basis of both biology and medicine. Our principal aim is to explore how this situation arose and has been allowed to continue seemingly unchallenged for more than 150 years. The main shortcomings of diffusion theory will be briefly reviewed to show that the entrenchment of this theory in the corpus of biological knowledge needs to be explained, especially as there are equally valid historical grounds for presuming that bulk fluid movement powered by the energy of cell metabolism plays a prominent note in the transport of molecules in the living body. First, the theory's evolution, notably from its origins in connection with the mechanistic materialist philosophy of mid nineteenth century physiology, is discussed. Following this, the entrenchment of the theory in twentieth century biology is analyzed in relation to three situations: the mechanism of oxygen transport between air and mammalian tissues; the structure and function of cell membranes; and the nature of the intermediary metalbolism, with its implicit presumptions about the intracellular organization and the movement of molecules within it. In our final section, we consider several historically based alternatives to diffusion theory, all of which have their precursors in nineteenth and twentieth century philosophy of science.

  3. Teachers' Opinions About Some Teaching Material Involving History of Mathematics

    ERIC Educational Resources Information Center

    Fraser, Barry J.; Koop, Anthony J.

    1978-01-01

    A questionnaire survey was used to gauge the opinions of mathematics teachers about some history of mathematics materials recently developed for use in the classroom. Teachers' opinions of the materials were generally favorable, but a sizeable proportion responded that they would not use the material in their own teaching. (Author/MN)

  4. Interfacing materials science and biology for drug carrier design.

    PubMed

    Such, Georgina K; Yan, Yan; Johnston, Angus P R; Gunawan, Sylvia T; Caruso, Frank

    2015-04-08

    Over the last ten years, there has been considerable research interest in the development of polymeric carriers for biomedicine. Such delivery systems have the potential to significantly reduce side effects and increase the bioavailability of poorly soluble therapeutics. The design of carriers has relied on harnessing specific variations in biological conditions, such as pH or redox potential, and more recently, by incorporating specific peptide cleavage sites for enzymatic hydrolysis. Although much progress has been made in this field, the specificity of polymeric carriers is still limited when compared with their biological counterparts. To synthesize the next generation of carriers, it is important to consider the biological rationale for materials design. This requires a detailed understanding of the cellular microenvironments and how these can be harnessed for specific applications. In this review, several important physiological cues in the cellular microenvironments are outlined, with a focus on changes in pH, redox potential, and the types of enzymes present in specific regions. Furthermore, recent studies that use such biologically inspired triggers to design polymeric carriers are highlighted, focusing on applications in the field of therapeutic delivery.

  5. Mechanisms of microwave-induced damage in biologic materials

    SciTech Connect

    Litovitz, T.A.; Meister, R.; Mohr, R.K.; Montrose, C.J.; Mullins, J.M.

    1990-01-01

    This report is divided into four chapters which correspond to the four main lines of research being carried out under the contract. In brief, these are (1) mathematical modeling studies, (2) experimental spectroscopic studies, (3) engineering design research, and (4) experimental biological studies. The research program is structured to attempt to discover the biological effects at the cell and molecular level that result from exposure to electromagnetic radiation. The main thrust is on the athermal effects of exposure to microwaves. Because recent work has suggested that significant cellular effects occur only when the microwaves are amplitude modulated, either with extremely low frequency (ELF) sinusoids or with pulses, we have hypothesized that the interaction of the microwave fields with cells must involve a demodulation or detection step. As a result, research designed to develop an understanding of the effects of direct ELF exposure becomes not only relevant, but vital.

  6. Developmental biology meets materials science: Morphogenesis of biomineralized structures.

    PubMed

    Wilt, Fred H

    2005-04-01

    Biomineralization is the process by which metazoa form hard minerals for support, defense, and feeding. The minerals so formed, e.g., teeth, bones, shells, carapaces, and spicules, are of considerable interest to chemists and materials scientists. The cell biology underlying biomineralization is not well understood. The study of the formation of mineralized structures in developing organisms offers opportunities for understanding some intriguing aspects of cell and developmental biology. Five examples of biomineralization are presented: (1) the formation of siliceous spicules and frustules in sponges and diatoms, respectively; (2) the structure of skeletal spicules composed of amorphous calcium carbonate in some tunicates; (3) the secretion of the prism and nacre of some molluscan shells; (4) the development of skeletal spicules of sea urchin embryos; and (5) the formation of enamel of vertebrate teeth. Some speculations on the cellular and molecular mechanisms that support biomineralization, and their evolutionary origins, are discussed.

  7. Biology and cytotoxicity of dental materials: an in vitro study.

    PubMed

    Gociu, M; Pătroi, D; Prejmerean, Cristina; Păstrăv, O; Boboia, Stanca; Prodan, Doina; Moldovan, Marioara

    2013-01-01

    The purpose of the experiment was to determine the degree of biocompatibility of a sealer (RO, laboratory made product) dental material in terms of cytotoxicity and animal tests. In the present study, the biological compatibility of eight experimental composite materials was examined by in vitro methods. The bio-composites used for the cytotoxicity test were placed into direct contact with normal human fibroblasts in a cell-culture dish. After fibroblast bioassay was performed, a duplicate sample of biomaterial was placed in each well, and then the fibroblasts were incubated for 48 hours at 37°C and 5% carbon dioxide. Local reactions after the implantation of the material regarding preclinical evaluation have been carried out within the Biobase Laboratory of the "Iuliu Hatieganu" University of Medicine and Pharmacy, Cluj-Napoca, Romania. The biocompatibility was studied using the tolerance test by the subcutaneous and intramuscular implantation of the cured specimens. The sealant C3 scored the highest value to the cell viability. The results of the present study showed that different dental materials had different effects on cells. The resin monomer TEGDMA, present in the sealer's composition, increased the amount of intracellular reactive oxygen species. Resin-based composites are cytotoxic before polymerization and immediately thereafter, whereas already set specimens cause almost no reaction. The test of tolerance showed that the composite materials do not contain any toxic, irritant substances or destructive ones for the living cells or tissues. The tests with experimental composite materials revealed that they are not cytotoxic for the living cells, in all versions of the materials used. All the samples of composite materials have maintained their integrity during the experiment, allowing the testing together with the embedded cells, which proved good viability, so they are suitable for dentistry use.

  8. Ultrafast electron microscopy in materials science, biology, and chemistry

    SciTech Connect

    King, Wayne E.; Campbell, Geoffrey H.; Frank, Alan; Reed, Bryan; Schmerge, John F.; Siwick, Bradley J.; Stuart, Brent C.; Weber, Peter M.

    2005-06-01

    The use of pump-probe experiments to study complex transient events has been an area of significant interest in materials science, biology, and chemistry. While the emphasis has been on laser pump with laser probe and laser pump with x-ray probe experiments, there is a significant and growing interest in using electrons as probes. Early experiments used electrons for gas-phase diffraction of photostimulated chemical reactions. More recently, scientists are beginning to explore phenomena in the solid state such as phase transformations, twinning, solid-state chemical reactions, radiation damage, and shock propagation. This review focuses on the emerging area of ultrafast electron microscopy (UEM), which comprises ultrafast electron diffraction (UED) and dynamic transmission electron microscopy (DTEM). The topics that are treated include the following: (1) The physics of electrons as an ultrafast probe. This encompasses the propagation dynamics of the electrons (space-charge effect, Child's law, Boersch effect) and extends to relativistic effects. (2) The anatomy of UED and DTEM instruments. This includes discussions of the photoactivated electron gun (also known as photogun or photoelectron gun) at conventional energies (60-200 keV) and extends to MeV beams generated by rf guns. Another critical aspect of the systems is the electron detector. Charge-coupled device cameras and microchannel-plate-based cameras are compared and contrasted. The effect of various physical phenomena on detective quantum efficiency is discussed. (3) Practical aspects of operation. This includes determination of time zero, measurement of pulse-length, and strategies for pulse compression. (4) Current and potential applications in materials science, biology, and chemistry. UEM has the potential to make a significant impact in future science and technology. Understanding of reaction pathways of complex transient phenomena in materials science, biology, and chemistry will provide fundamental

  9. Processing and analysis techniques involving in-vessel material generation

    DOEpatents

    Schabron, John F.; Rovani, Jr., Joseph F.

    2011-01-25

    In at least one embodiment, the inventive technology relates to in-vessel generation of a material from a solution of interest as part of a processing and/or analysis operation. Preferred embodiments of the in-vessel material generation (e.g., in-vessel solid material generation) include precipitation; in certain embodiments, analysis and/or processing of the solution of interest may include dissolution of the material, perhaps as part of a successive dissolution protocol using solvents of increasing ability to dissolve. Applications include, but are by no means limited to estimation of a coking onset and solution (e.g., oil) fractionating.

  10. Processing and analysis techniques involving in-vessel material generation

    DOEpatents

    Schabron, John F [Laramie, WY; Rovani, Jr., Joseph F.

    2012-09-25

    In at least one embodiment, the inventive technology relates to in-vessel generation of a material from a solution of interest as part of a processing and/or analysis operation. Preferred embodiments of the in-vessel material generation (e.g., in-vessel solid material generation) include precipitation; in certain embodiments, analysis and/or processing of the solution of interest may include dissolution of the material, perhaps as part of a successive dissolution protocol using solvents of increasing ability to dissolve. Applications include, but are by no means limited to estimation of a coking onset and solution (e.g., oil) fractionating.

  11. Microdetermination of calcium and magnesium in biological materials

    PubMed Central

    Bowden, C. H.; Patston, Valerie J.

    1963-01-01

    The use of the dye calcon (1-(2 hydroxy-1-naphthylazo)-2-naphthol-4 sulphonic acid) for the estimation of calcium using E.D.T.A. and a commercial photoelectric titrimeter is described. The interfering effects of magnesium and phosphate have been overcome. The method has been extended to estimations on biological materials. Results on 55 sera show that the E.D.T.A./calcon method gave slightly lower results (—0·15 mg./100 ml. ± 0·029) than the oxalate precipitation method. Magnesium may also be estimated by incorporating the use of Eriochrome black T. PMID:14014590

  12. Biologic properties of surgical scaffold materials derived from dermal ECM.

    PubMed

    Kulig, Katherine M; Luo, Xiao; Finkelstein, Eric B; Liu, Xiang-Hong; Goldman, Scott M; Sundback, Cathryn A; Vacanti, Joseph P; Neville, Craig M

    2013-07-01

    Surgical scaffold materials manufactured from donor human or animal tissue are increasingly being used to promote soft tissue repair and regeneration. The clinical product consists of the residual extracellular matrix remaining after a rigorous decellularization process. Optimally, the material provides both structural support during the repair period and cell guidance cues for effective incorporation into the regenerating tissue. Surgical scaffold materials are available from several companies and are unique products manufactured by proprietary methodology. A significant need exists for a more thorough understanding of scaffold properties that impact the early steps of host cell recruitment and infiltration. In this study, a panel of in vitro assays was used to make direct comparisons of several similar, commercially-available materials: Alloderm, Medeor Matrix, Permacol, and Strattice. Differences in the materials were detected for both cell signaling and scaffold architecture-dependent cell invasion. Material-conditioned media studies found Medeor Matrix to have the greatest positive effect upon cell proliferation and induction of migration. Strattice provided the greatest chemotaxis signaling and best suppressed apoptotic induction. Among assays measuring structure-dependent properties, Medeor Matrix was superior for cell attachment, followed by Permacol. Only Alloderm and Medeor Matrix supported chemotaxis-driven cell invasion beyond the most superficial zone. Medeor Matrix was the only material in the chorioallantoic membrane assay to support substantial cell invasion. These results indicate that both biologic and structural properties need to be carefully assessed in the considerable ongoing efforts to develop new uses and products in this important class of biomaterials. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Friction properties of biological functional materials: PVDF membranes.

    PubMed

    Chen, Long; Di, Changan; Chen, Xuguang; Li, Zhengzhi; Luo, Jia

    2017-01-02

    Touch is produced by sensations that include approaching, sliding, pressing, and temperature. This concept has become a target of research in biotechnology, especially in the field of bionic biology. This study measured sliding and pressing with traditional tactile sensors in order to improve a machine operator's judgment of surface roughness. Based on the theory of acoustic emission, this study combined polyvinylidene fluoride (PVDF) with a sonic transducer to produce tactile sensors that can detect surface roughness. Friction between PVDF films and experimental materials generated tiny acoustic signals that were transferred into electrical signals through a sonic transducer. The characteristics of the acoustic signals for the various materials were then analyzed. The results suggest that this device can effectively distinguish among different objects based on roughness. Tactile sensors designed using this principle and structure function very similarly to the human body in recognizing the surface of an object.

  14. Peptide Self-Assembly for Crafting Functional Biological Materials

    PubMed Central

    Matson, John B.; Zha, R. Helen; Stupp, Samuel I.

    2011-01-01

    Self-assembling, peptide-based scaffolds are frontrunners in the search for biomaterials with widespread impact in regenerative medicine. The inherent biocompatibility and cell signaling capabilities of peptides, in combination with control of secondary structure, has led to the development of a broad range of functional materials with potential for many novel therapies. More recently, membranes formed through complexation of peptide nanostructures with natural biopolymers have led to the development of hierarchically-structured constructs with potentially far-reaching applications in biology and medicine. In this review, we highlight recent advances in peptide-based gels and membranes, including work from our group and others. Specifically, we discuss the application of peptide-based materials in the regeneration of bone and enamel, cartilage, and the central nervous system, as well as the transplantation of islets, wound-healing, cardiovascular therapies, and treatment of erectile dysfunction after prostatectomy PMID:22125413

  15. [Practical knowledge in fungal diagnosis in some biological materials].

    PubMed

    Mencl, Karel

    2012-08-01

    The article deals with certain problematic issues associated with routine laboratory diagnosis of mycoses from secretions and samples taken from the respiratory tract and maxillary sinuses as well as samples of skin and skin appendages. The text is based on both the author's own long-term experience and experience gained from cooperation with other laboratories. To improve the detection of filamentous fungi in lower respiratory tract secretions, it is recommended to use 0.5 mL of the material for individual culture media. In both secretions and other biological material, the role of microscopic examination is stressed. In many cases, this may also be the only reliable laboratory procedure. Detection of filamentous fungi should be interpreted in close cooperation with clinicians, especially in order to obtain history data. These are particularly important in the diagnosis of endemic mycoses. Equivocal or unusual findings should be verified by repeated laboratory tests.

  16. DNASU plasmid and PSI:Biology-Materials repositories: resources to accelerate biological research.

    PubMed

    Seiler, Catherine Y; Park, Jin G; Sharma, Amit; Hunter, Preston; Surapaneni, Padmini; Sedillo, Casey; Field, James; Algar, Rhys; Price, Andrea; Steel, Jason; Throop, Andrea; Fiacco, Michael; LaBaer, Joshua

    2014-01-01

    The mission of the DNASU Plasmid Repository is to accelerate research by providing high-quality, annotated plasmid samples and online plasmid resources to the research community through the curated DNASU database, website and repository (http://dnasu.asu.edu or http://dnasu.org). The collection includes plasmids from grant-funded, high-throughput cloning projects performed in our laboratory, plasmids from external researchers, and large collections from consortia such as the ORFeome Collaboration and the NIGMS-funded Protein Structure Initiative: Biology (PSI:Biology). Through DNASU, researchers can search for and access detailed information about each plasmid such as the full length gene insert sequence, vector information, associated publications, and links to external resources that provide additional protein annotations and experimental protocols. Plasmids can be requested directly through the DNASU website. DNASU and the PSI:Biology-Materials Repositories were previously described in the 2010 NAR Database Issue (Cormier, C.Y., Mohr, S.E., Zuo, D., Hu, Y., Rolfs, A., Kramer, J., Taycher, E., Kelley, F., Fiacco, M., Turnbull, G. et al. (2010) Protein Structure Initiative Material Repository: an open shared public resource of structural genomics plasmids for the biological community. Nucleic Acids Res., 38, D743-D749.). In this update we will describe the plasmid collection and highlight the new features in the website redesign, including new browse/search options, plasmid annotations and a dynamic vector mapping feature that was developed in collaboration with LabGenius. Overall, these plasmid resources continue to enable research with the goal of elucidating the role of proteins in both normal biological processes and disease.

  17. Inverse Algorithm Optimization for Determining Optical Properties of Biological Materials from Spatially-Resolved Diffuse Reflectance

    USDA-ARS?s Scientific Manuscript database

    Optical characterization of biological materials is useful in many scientific and industrial applications like biomedical diagnosis and nondestructive quality evaluation of food and agricultural products. However, accurate determination of the optical properties from intact biological materials base...

  18. Results of UV laser application on biological material

    NASA Astrophysics Data System (ADS)

    Alifano, P.; Nassisi, Vincenzo; Pompa, Pier P.; Candido, A.

    2002-08-01

    In this paper we report on the biological effects of XeCL laser irradiation on Staphylococcus epidermidis and Escherichia coli. UV interaction with cellular systems is responsible for photochemical, photothermal or photodecomposition processes. When short-wavelength UV radiation strikes biological material, the DNA is damaged causing cell killing, mutagenesis or carcinogenesis. We report on different effects of XeCl laser irradiation on two microbial systems; collection strain of Staphylococcus epidermidis (in suspension) and collection strains of Eschericha coli proficient or deficient in DNA recombination/repair pathways (irradiated on solid surfaces). In S epidermidis the 308 nm radiation can significantly enhanced the proliferation rates. In wild type E. coli cells the radiation did not stimulate the growth rates. Surprisingly, the 308 nm radiation elicited a very strong lethal effect on DNA recombination/repair-defective strains (harbouring the recA56 null mutation), even more pronounced than irradiation with a UV 254 nm germicidal lamp. The unknown mechanism responsible for this biological response is currently under investigation.

  19. Micro-buckling in the nanocomposite structure of biological materials

    NASA Astrophysics Data System (ADS)

    Su, Yewang; Ji, Baohua; Hwang, Keh-Chih; Huang, Yonggang

    2012-10-01

    Nanocomposite structure, consisting of hard mineral and soft protein, is the elementary building block of biological materials, where the mineral crystals are arranged in a staggered manner in protein matrix. This special alignment of mineral is supposed to be crucial to the structural stability of the biological materials under compressive load, but the underlying mechanism is not yet clear. In this study, we performed analytical analysis on the buckling strength of the nanocomposite structure by explicitly considering the staggered alignment of the mineral crystals, as well as the coordination among the minerals during the buckling deformation. Two local buckling modes of the nanostructure were identified, i.e., the symmetric mode and anti-symmetric mode. We showed that the symmetric mode often happens at large aspect ratio and large volume fraction of mineral, while the anti-symmetric happens at small aspect ratio and small volume fraction. In addition, we showed that because of the coordination of minerals with the help of their staggered alignment, the buckling strength of these two modes approached to that of the ideally continuous fiber reinforced composites at large aspect ratio given by Rosen's model, insensitive to the existing "gap"-like flaws between mineral tips. Furthermore, we identified a mechanism of buckling mode transition from local to global buckling with increase of aspect ratio, which was attributed to the biphasic dependence of the buckling strength on the aspect ratio. That is, for small aspect ratio, the local buckling strength is smaller than that of global buckling so that it dominates the buckling behavior of the nanocomposite; for comparatively larger aspect ratio, the local buckling strength is higher than that of global buckling so that the global buckling dominates the buckling behavior. We also found that the hierarchical structure can effectively enhance the buckling strength, particularly, this structural design enables

  20. Analytical chemistry at the interface between materials science and biology

    NASA Astrophysics Data System (ADS)

    O'Brien, Janese Christine

    This work describes several research efforts that lie at the new interfaces between analytical chemistry and other disciplines, namely materials science and biology. In the materials science realm, the search for new materials that may have useful or unique chromatographic properties motivated the synthesis and characterization of electrically conductive sol-gels. In the biology realm, the search for new surface fabrication schemes that would permit or even improve the detection of specific biological reactions motivated the design of miniaturized biological arrays. Collectively, this work represents some of analytical chemistry's newest forays into these disciplines. This dissertation is divided into six chapters. Chapter 1 is an introductory chapter that provides background information pertinent to several key aspects of the work contained in this dissertation. Chapter 2 describes the synthesis and characterization of electrically conductive sol-gels derived from the acid-catalyzed hydrolysis of a vanadium alkoxide. Specifically, this chapter describes our attempts to increase the conductivity of vanadium sol-gels by optimizing the acidic and drying conditions used during synthesis. Chapter 3 reports the construction of novel antigenic immunosensing platforms of increased epitope density using Fab'-SH antibody fragments on gold. Here, X-ray photoelectron spectroscopy (XPS), thin-layer cell (TLC) and confocal fluorescence spectroscopies, and scanning force microscopy (SFM) are employed to characterize the fragment-substrate interaction, to quantify epitope density, and to demonstrate fragment viability and specificity. Chapter 4 presents a novel method for creating and interrogating double-stranded DNA (dsDNA) microarrays suitable for screening protein:dsDNA interactions. Using the restriction enzyme ECoR1, we demonstrate the ability of the atomic force microscope (AFM) to detect changes in topography that result from the enzymatic cleavage of dsDNA microarrays

  1. Access and benefit sharing of Antarctica's biological material.

    PubMed

    Puig-Marcó, Roser

    2014-10-01

    Searching and sampling of Antarctic Biological Material (ABM) is happening with no explicit regulation on access and benefit sharing requirements. Patents already exist on inventions stemming from Antarctic living organisms. The Antarctic Treaty System (ATS) provides mechanisms to ensure that scientific knowledge and data generated from the collection and use of ABM are shared, although commercialization might be a threat to this free exchange of scientific knowledge. Some of the underlying problems regarding the access and benefit sharing of ABM are that under the ATS there are gaps concerning definitions, access to specimens, benefit sharing, commercialization and reporting issues. The Antarctic Treaty Consultative Parties (ATCPs) have decided that the Antarctic Treaty Consultative Meeting (ATCM) is the competent body to discuss the matter, and the ATS is the appropriate framework for managing the collection of biological material in the Antarctic Treaty area and for considering its use. Nevertheless, opinions diverge as to the need for more specific rules on access and benefit sharing other than that already resulting from the obligation to give prior notification and share scientific results.

  2. Fluid–structure interaction involving large deformations: 3D simulations and applications to biological systems

    PubMed Central

    Tian, Fang-Bao; Dai, Hu; Luo, Haoxiang; Doyle, James F.; Rousseau, Bernard

    2013-01-01

    Three-dimensional fluid–structure interaction (FSI) involving large deformations of flexible bodies is common in biological systems, but accurate and efficient numerical approaches for modeling such systems are still scarce. In this work, we report a successful case of combining an existing immersed-boundary flow solver with a nonlinear finite-element solid-mechanics solver specifically for three-dimensional FSI simulations. This method represents a significant enhancement from the similar methods that are previously available. Based on the Cartesian grid, the viscous incompressible flow solver can handle boundaries of large displacements with simple mesh generation. The solid-mechanics solver has separate subroutines for analyzing general three-dimensional bodies and thin-walled structures composed of frames, membranes, and plates. Both geometric nonlinearity associated with large displacements and material nonlinearity associated with large strains are incorporated in the solver. The FSI is achieved through a strong coupling and partitioned approach. We perform several validation cases, and the results may be used to expand the currently limited database of FSI benchmark study. Finally, we demonstrate the versatility of the present method by applying it to the aerodynamics of elastic wings of insects and the flow-induced vocal fold vibration. PMID:24415796

  3. Fluid-structure interaction involving large deformations: 3D simulations and applications to biological systems

    NASA Astrophysics Data System (ADS)

    Tian, Fang-Bao; Dai, Hu; Luo, Haoxiang; Doyle, James F.; Rousseau, Bernard

    2014-02-01

    Three-dimensional fluid-structure interaction (FSI) involving large deformations of flexible bodies is common in biological systems, but accurate and efficient numerical approaches for modeling such systems are still scarce. In this work, we report a successful case of combining an existing immersed-boundary flow solver with a nonlinear finite-element solid-mechanics solver specifically for three-dimensional FSI simulations. This method represents a significant enhancement from the similar methods that are previously available. Based on the Cartesian grid, the viscous incompressible flow solver can handle boundaries of large displacements with simple mesh generation. The solid-mechanics solver has separate subroutines for analyzing general three-dimensional bodies and thin-walled structures composed of frames, membranes, and plates. Both geometric nonlinearity associated with large displacements and material nonlinearity associated with large strains are incorporated in the solver. The FSI is achieved through a strong coupling and partitioned approach. We perform several validation cases, and the results may be used to expand the currently limited database of FSI benchmark study. Finally, we demonstrate the versatility of the present method by applying it to the aerodynamics of elastic wings of insects and the flow-induced vocal fold vibration.

  4. Agricultural biological reference materials for analytical quality control

    SciTech Connect

    Ihnat, M.

    1986-01-01

    Cooperative work is under way at Agriculture Canada, US Department of Agriculture, and US National Bureau of Standards in an attempt to fill some of the gaps in the world repertoire of reference materials and to provide much needed control materials for laboratories' day to day operations. This undertaking involves the preparation and characterization of a number of agricultural and food materials for data quality control for inorganic constituents. Parameters considered in the development of these materials were material selection based on importance in commerce and analysis; techniques of preparation, processing, and packaging; physical and chemical characterization; homogeneity testing and quantitation (certification). A large number of agricultural/food products have been selected to represent a wide range of not only levels of sought-for constituents (elements) but also a wide range of matrix components such as protein, carbohydrate, dietary fiber, fat, and ash. Elements whose concentrations are being certified cover some two dozen major, minor, and trace elements of nutritional, toxicological, and environmental significance.

  5. Biology Teacher and Expert Opinions about Computer Assisted Biology Instruction Materials: A Software Entitled Nucleic Acids and Protein Synthesis

    ERIC Educational Resources Information Center

    Hasenekoglu, Ismet; Timucin, Melih

    2007-01-01

    The aim of this study is to collect and evaluate opinions of CAI experts and biology teachers about a high school level Computer Assisted Biology Instruction Material presenting computer-made modelling and simulations. It is a case study. A material covering "Nucleic Acids and Protein Synthesis" topic was developed as the…

  6. Neutron activation analysis of biological materials by the monostandard method.

    PubMed

    Takeuchi, T; Shinogi, M

    1979-12-01

    Instrumental neutron activation analysis by the monostandard method has been applied to the analyses of biological NBS standard reference materials; 1571 Orchard Leaves and 1577 Bovine Liver. Aluminum foils containing 0.100% gold or 2.00% cobalt were used as the monostandards. The gamma-ray spectral data were recorded on punched paper tape and were analyzed by a computer assisted data processing. The following 25 elements were determined: Al, Ca, Cl Cu, Mg, Mn, V (by short period irradiation), As, Ba, Br, Co, Cr, Cs, Eu, Fe, Hg, K, La, Na, Rb, Sb, Sc, Se, Sm and Zn (by long period irradiation). The results were compared with the certified values by NBS and the reported values in literatures to prove the reliability and accuracy of the monostandard method.

  7. Visualizing old biological traces on different materials without using chemicals.

    PubMed

    Sterzik, V; Hinderberger, P; Panzer, S; Bohnert, M

    2017-09-05

    During the investigative process that typically follows a criminal act, it may prove necessary to work with and analyze evidence that is not recent but old. This could become necessary, for example, when a crime is discovered some time after it was committed or when a cold case is reopened. Due to this need, the present study focused on the detection and visualization of 2-year-old biological traces. To do so, an alternative light source and different filters were used. The optical behavior of 2-year-old samples of blood, semen, urine, saliva, and sweat located on 19 different materials was documented, analyzed, and compared with the optical behavior of the same samples when they were recent [1].

  8. Ion beam modification of biological materials in nanoscale

    NASA Astrophysics Data System (ADS)

    Yu, L. D.; Anuntalabhochai, S.

    2012-07-01

    Ion interaction with biological objects in nanoscale is a novel research area stemming from applications of low-energy ion beams in biotechnology and biomedicine. Although the ion beam applications in biotechnology and biomedicine have achieved great successes, many mechanisms remain unclear and many new applications are to be explored. We have carried out some research on exploring the mechanisms and new applications besides attaining ion beam induction of mutation breeding and gene transformation. In the studies on the mechanisms, we focused our investigations on the direct interaction in nanoscale between ions and biological living materials. Our research topics have included the low-energy ion range in DNA, low-energy ion or neutral beam bombardment effect on DNA topological form change and mutation, low-energy ion or neutral beam bombardment effect on the cell envelope and gene transformation, and molecular dynamics simulation of ultra-low-energy ion irradiation of DNA. In the exploration of new applications, we have started experiments on ion irradiation or bombardment, in the nanoscaled depth or area, of human cells for biomedical research. This paper introduces our experiments and reports interesting results.

  9. Analysis of 4-MEC in biological and non-biological material--three case reports.

    PubMed

    Gil, Dominika; Adamowicz, Piotr; Skulska, Agnieszka; Tokarczyk, Bogdan; Stanaszek, Roman

    2013-05-10

    4-Methylethcathinone (4-MEC) is a designer drug that is structurally similar to mephedrone. This substance was identified in many drug seizures analyzed in the Institute of Forensic Research (IFR). This paper describes three of the first cases in which both powders and biological material were secured at the same time and delivered to the IFR for toxicological analysis. The first case concerned a man who died in a car crash. The second case describes a death associated with multiple-drug intake, including 4-MEC. In this case, however, the death was the result of an overdose of para-methoxyamphetamine (PMA). In the third case, the man was arrested for possession of illicit drugs. Analysis of powders was carried out using gas chromatography-mass spectrometry (GC-MS) and high pressure liquid chromatography with diode array detection (HPLC-DAD). The purity of 4-MEC found in powder samples was 51% and 78%. Analyses of biological material were carried out using liquid chromatography-tandem mass spectrometry (LC-MS/MS). 4-MEC was found in blood samples at concentrations of 46, 56 and 152 ng/mL. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Hollows on Mercury: Materials and mechanisms involved in their formation

    NASA Astrophysics Data System (ADS)

    Thomas, Rebecca J.; Rothery, David A.; Conway, Susan J.; Anand, Mahesh

    2014-02-01

    Recent images of the surface of Mercury have revealed an unusual and intriguing landform: sub-kilometre scale, shallow, flat-floored, steep-sided rimless depressions typically surrounded by bright deposits and generally occurring in impact craters. These ‘hollows’ appear to form by the loss of a moderately-volatile substance from the planet’s surface and their fresh morphology and lack of superposed craters suggest that this process has continued until relatively recently (and may be on-going). Hypotheses to explain the volatile-loss have included sublimation and space weathering, and it has been suggested that hollow-forming volatiles are endogenic and are exposed at the surface during impact cratering. However, detailed verification of these hypotheses has hitherto been lacking. In this study, we have conducted a comprehensive survey of all MESSENGER images obtained up to the end of its fourth solar day in orbit in order to identify hollowed areas. We have studied how their location relates to both exogenic processes (insolation, impact cratering, and solar wind) and endogenic processes (explosive volcanism and flood lavas) on local and regional scales. We find that there is a weak correlation between hollow formation and insolation intensity, suggesting formation may occur by an insolation-related process such as sublimation. The vast majority of hollow formation is in localised or regional low-reflectance material within impact craters, suggesting that this low-reflectance material is a volatile-bearing unit present below the surface that becomes exposed as a result of impacts. In many cases hollow occurrence is consistent with formation in volatile-bearing material exhumed and exposed during crater formation, while in other cases volatiles may have accessed the surface later through re-exposure and possibly in association with explosive volcanism. Hollows occur at the surface of thick flood lavas only where a lower-reflectance substrate has been exhumed

  11. Review: nomenclature and biologic significance of cytokines involved in inflammation and the host immune response.

    PubMed

    Liles, W C; Van Voorhis, W C

    1995-12-01

    This is a brief review of 42 cytokines and interleukins that are involved inflammatory and immune responses. The cytokines are listed in tables organized as hematopoietic growth factors, interferons, lymphokines, monokines, chemokines, and other cytokines. Information on each cytokine includes the most commonly used abbreviations, the former or alternative names and abbreviations of the cytokines, the cells that form the major sources of production of the cytokines, the major biologic actions of the cytokines, and references to recent reviews or primary literature. Minor biologic actions and minor cellular sources of the cytokines may not be listed. This review should be useful as a quick reference guide to the cytokines and interleukins.

  12. Giant and universal magnetoelectric coupling in soft materials and concomitant ramifications for materials science and biology

    NASA Astrophysics Data System (ADS)

    Liu, Liping; Sharma, Pradeep

    2013-10-01

    Magnetoelectric coupling—the ability of a material to magnetize upon application of an electric field and, conversely, to polarize under the action of a magnetic field—is rare and restricted to a rather small set of exotic hard crystalline materials. Intense research activity has recently ensued on materials development, fundamental scientific issues, and applications related to this phenomenon. This tantalizing property, if present in adequate strength at room temperature, can be used to pave the way for next-generation memory devices such as miniature magnetic random access memories and multiple state memory bits, sensors, energy harvesting, spintronics, among others. In this Rapid Communication, we prove the existence of an overlooked strain mediated nonlinear mechanism that can be used to universally induce the giant magnetoelectric effect in all (sufficiently) soft dielectric materials. For soft polymer foams—which, for instance, may be used in stretchable electronics—we predict room-temperature magnetoelectric coefficients that are comparable to the best known (hard) composite materials created. We also argue, based on a simple quantitative model, that magnetoreception in some biological contexts (e.g., birds) most likely utilizes this very mechanism.

  13. Giant and universal magnetoelectric coupling in soft materials and concomitant ramifications for materials science and biology.

    PubMed

    Liu, Liping; Sharma, Pradeep

    2013-10-01

    Magnetoelectric coupling-the ability of a material to magnetize upon application of an electric field and, conversely, to polarize under the action of a magnetic field-is rare and restricted to a rather small set of exotic hard crystalline materials. Intense research activity has recently ensued on materials development, fundamental scientific issues, and applications related to this phenomenon. This tantalizing property, if present in adequate strength at room temperature, can be used to pave the way for next-generation memory devices such as miniature magnetic random access memories and multiple state memory bits, sensors, energy harvesting, spintronics, among others. In this Rapid Communication, we prove the existence of an overlooked strain mediated nonlinear mechanism that can be used to universally induce the giant magnetoelectric effect in all (sufficiently) soft dielectric materials. For soft polymer foams-which, for instance, may be used in stretchable electronics-we predict room-temperature magnetoelectric coefficients that are comparable to the best known (hard) composite materials created. We also argue, based on a simple quantitative model, that magnetoreception in some biological contexts (e.g., birds) most likely utilizes this very mechanism.

  14. Molecular mechanisms of tolerance in tardigrades: new perspectives for preservation and stabilization of biological material.

    PubMed

    Schill, Ralph O; Mali, Brahim; Dandekar, Thomas; Schnölzer, Martina; Reuter, Dirk; Frohme, Marcus

    2009-01-01

    Certain organisms found across a range of taxa, including bacteria, yeasts, plants and many invertebrates such as nematodes and tardigrades are able to survive almost complete loss of body water. The dry organisms may remain in this state, which is known as anhydrobiosis, for decades without apparent damage. When water again becomes available, they rapidly rehydrate and resume active life. Research in anhydrobiosis has focused mainly on sugar metabolism and stress proteins. Despite the discovery of various molecules which are involved in desiccation and water stress, knowledge of the regulatory network governing the stability of the cellular architecture and the metabolic machinery during dehydration is still fragmentary and not well understood. A combination of transcriptional, proteomic and metabolic approaches with bioinformatics tools can provide a better understanding of gene regulation that underlie the biological functions and physiology related to anhydrobiosis. The development of this concept will raise exciting possibilities and techniques for the preservation and stabilization of biological materials in the dry state.

  15. Structural and functional biological materials: Abalone nacre, sharp materials, and abalone foot adhesion

    NASA Astrophysics Data System (ADS)

    Lin, Albert Yu-Min

    A three-part study of lessons from nature is presented through the examination of various biological materials, with an emphasis on materials from the mollusk Haliotis rufescens, commonly referred to as the red abalone. The three categories presented are: structural hierarchy, self-assembly, and functionality. Ocean mollusk shells are composed of aragonite/calcite crystals interleaved with layers of a visco-elastic protein, having dense, tailored structures with excellent mechanical properties. The complex nano-laminate structure of this bio-composite material is characterized and related to its mechanical properties. Three levels of structural hierarchy are identified: macroscale mesolayers separating larger regions of tiled aragonite, microscale organization of 0.5 mum by 10 mum aragonite bricks; nanoscale mineral bridges passing through 30 nm layers of organic matrix separating individual aragonite tiles. Composition and growth mechanisms of this nanostructure were observed through close examination of laboratory-grown samples using scanning electron microscopy (SEM), Raman spectroscopy, and transmission electron microscopy (TEM). Glass slides and nacre pucks were implanted onto the growth surface of living abalone and removed periodically to observe trends in nacre deposition. Various deproteinization and demineralization experiments are used to explore the inorganic and organic components of the nacre's structure. The organic component of the shell is characterized by atomic force microscopy (AFM). The functionality of various biological materials is described and investigated. Two specific types of functionality are characterized, the ability of some materials to cut and puncture through sharp designs, and the ability for some materials to be used as attachment devices. Aspects of cutting materials employed by a broad range of animals were characterized and compared. In respect to the attachment mechanisms the foot of the abalone and the tree frog were

  16. Development of nanostructured biocompatible materials for chemical and biological sensors

    NASA Astrophysics Data System (ADS)

    Curley, Michael; Chilvery, Ashwith K.; Kukhatreva, Tatiana; Sharma, Anup; Corda, John; Farley, Carlton

    2012-10-01

    This research is focused on the fabrication of thin films followed by Surface Enhanced Raman Spectroscopy (SERS) testing of these films for various applications. One technique involves the mixture of nanoparticles with twophoton material to be used as an indicator dye. Another method involved embedding silver nanoparticles in a ceramic nano-membrane. The substrates were characterized by both Atom Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). We applied the nanostructured substrate to measure the SERS spectra of 10-6 Mol/L Rhodomine 6G(Rh6G), e-coli bacteria and RDX explosive. Our results showed that silver coated ceramic membranes can serve as appropriate substrates to enhance Raman signals. In addition, we demonstrated that the in-house-made colloidal silver can work for enhancement of the Raman spectra for bacteria. We measured the Raman spectra of Rh6G molecules on a substrate absorbed by a nanofluid of silver. We observed several strong Raman bands - 613cm-1,768 cm-1,1308cm-1 1356 cm-1,1510cm-1, which correspond to Rh6G vibrational modes υ53,υ65,υ115,υ117,υ146 respectively, using a ceramic membrane coated by silver. The Raman spectra of Rh6G absorbed by silver nanofluid showed strong enhancement of Raman bands 1175cm-1 and 1529cm-1, 1590 cm-1. Those correspond to vibrational frequency modes - υ103,υ151,152. We also measured the Raman spectra of e-coli bacteria, both absorbed by silver nanofluid, and on nanostructured substrate. In addition, the Fourier Transfer Infrared Spectra (FTIR) of the bacteria was measured.

  17. Organization and diffusion in biological and material fabrication problems

    NASA Astrophysics Data System (ADS)

    Mangan, Niall Mari

    This thesis is composed of two problems. The first is a systems level analysis of the carbon concentrating mechanism in cyanobacteria. The second presents a theoretical analysis of femtosecond laser melting for the purpose of hyperdoping silicon with sulfur. While these systems are very distant, they are both relevant to the development of alternative energy (production of biofuels and methods for fabricating photovoltaics respectively). Both problems are approached through analysis of the underlying diffusion equations. Cyanobacteria are photosynthetic bacteria with a unique carbon concentrating mechanism (CCM) which enhances carbon fixation. A greater understanding of this mechanism would offer new insights into the basic biology and methods for bioengineering more efficient biochemical reactions. The molecular components of the CCM have been well characterized in the last decade, with genetic analysis uncovering both variation and commonalities in CCMs across cyanobacteria strains. Analysis of CCMs on a systems level, however, is based on models formulated prior to the molecular characterization. We present an updated model of the cyanobacteria CCM, and analytic solutions in terms of the various molecular components. The solutions allow us to find the parameter regime (expression levels, catalytic rates, permeability of carboxysome shell) where carbon fixation is maximized and oxygenation is minimized. Saturation of RuBisCO, maximization of the ratio of CO2 to O2, and staying below or at the saturation level for carbonic anhydrase are all needed for maximum efficacy. These constraints limit the parameter regime where the most effective carbon fixation can occur. There is an optimal non-specific carboxysome shell permeability, where trapping of CO2 is maximized, but HCO3 - is not detrimentally restricted. The shell also shields carbonic anhydrase activity and CO2 → HCO3- conversion at the thylakoid and cell membrane from one another. Co-localization of carbonic

  18. Thermoelectric needle probe for temperature measurements in biological materials.

    PubMed

    Korn, U; Rav-Noy, Z; Shtrikman, S; Zafrir, M

    1980-04-01

    In certain biological and medical applications it is important to measure and follow temperature changes inside a body or tissue. Any probe inserted into a tissue causes damage to tissue and distortion to the initial temperature distribution. To minimize this interference, a fine probe is needed. Thus, thin film technology is advantageous and was utilized by us to produce sensitive probes for these applications. The resulting probe is a small thermocouple at the tip of a thin needle (acupuncture stainless steel needle, approximately 0.26 mm in diameter and length in the range 5-10 cm was used). The junction was produced at the needle's tip by coating the needle with thin layers of insulating and thermoelectric materials. The first layer is an insulating one and is composed of polyacrylonitrile (PAN) and polymide produced by plasma polymerization and dip-coating respectively. This layer covers all the needle except the tip. The second layer is a vacuum deposited thermoelectric thin layer of Bi-5% Sb alloy coating also the tip. The third layer is for insulation and protection and is composed of PAN and polyimide. In this arrangement the junction is at the needle's tip, the needle is one conductor, the thermoelectric layer is the other and they are isolated by the plastic layer. The probe is handy and mechanically sturdy. The sensitivity is typically 77 microV/degrees C at room temperature and is constant to within 2% up to 90 degrees C. The response is fast (less than 1 sec) the noise is small, (less than 0.05 degrees C) and because of the small dimension, damage to tissue and disturbance to the measured temperature field are minimal.

  19. New Recommendation on Biological Materials Could Hamper Muscular Dystrophy Research

    PubMed Central

    McCormack, Pauline; Woods, Simon

    2016-01-01

    The new ‘Recommendation of the Committee of Ministers to member States on research on biological materials of human origin’, adopted in Europe in May 2016 is confusing and lacks specificity on the research use of biomaterials taken from persons not able to consent. It is possible to interpret the relevant clauses in a restrictive manner and doing so would hamper biobank research, by requiring researchers or biobank curators to examine individual records in detail, to check they are adhering to the Recommendation. This would be particularly problematic for muscular dystrophy and other rare disease research, the progress of which relies increasingly on the sharing of biomaterials and data internationally, as it will add complexity to the logistics of biomaterials and data sharing and introduce barriers for researchers preparing biomaterials for sharing. Such barriers are contradictory to EC policies on promoting and funding rare disease research and removing barriers to better care and treatment. Such policies work in concert with international progress in rare disease research, in particular the NIH’s Rare Diseases Clinical Research Network and Genetic and Rare Diseases Information Centre. The rare disease community has in recent years worked to create a common framework of harmonised approaches to enable the responsible, voluntary, and secure sharing of biomaterials and data. These efforts are supported by the European Commission in such moves as FP7 funding to advance rare disease research and the introduction of National Plans for rare disease; and are bolstered by similar efforts in the USA via the Clinical and Translational Science Awards Program and the NIH/NCATS Patient Registry developments. Introducing Recommendations from the Committee of Ministers, containing clauses which are incompatible to the efforts to advance rare disease research, seems counter-productive. PMID:28133562

  20. Detection of buphedrone in biological and non-biological material--two case reports.

    PubMed

    Zuba, Dariusz; Adamowicz, Piotr; Byrska, Bogumiła

    2013-04-10

    Buphedrone (2-(methylamino)-1-phenylbutan-1-one, α-methylamino-butyrophenone, MABP) is a positional isomer of mephedrone. In Poland, it was marketed in the second half of 2010 after the banning of mephedrone. Buphedrone is a stimulant that is snorted, smoked or taken orally. This substance was identified in 15 products seized by law enforcement after August 2010 and analysed in the Institute of Forensic Research (IFR). Buphedrone was the sole psychoactive substance in only 5 products. It was mixed mainly with 4-MEC and MDPV. This paper presents two cases in which both biological and non-biological materials were delivered to the IFR for toxicological analysis. In the first case, a passenger car crashed into a truck. The car driver suffered severe injuries resulting in his death. During external inspection of the deceased the police discovered several packages containing a white powder. In the second case, a man was arrested for possession of illicit drugs. Analysis of powders was carried out using gas chromatography-mass spectrometry (GC-MS) and high-pressure liquid chromatography with diode array detection (HPLC-DAD). The purity of buphedrone found in powder samples was in the range of 58-68%. Analyses of blood were carried out using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Buphedrone was found in the blood of the deceased at a concentration of 127 ng/mL and of the drug user/seller at 3 ng/mL. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  1. Diurnal rhythmicity in biological processes involved in bioavailability of functional food factors.

    PubMed

    Tsurusaki, Takashi; Sakakibara, Hiroyuki; Aoshima, Yoshiki; Yamazaki, Shunsuke; Sakono, Masanobu; Shimoi, Kayoko

    2013-05-01

    In the past few decades, many types of functional factors have been identified in dietary foods; for example, flavonoids are major groups widely distributed in the plant kingdom. However, the absorption rates of the functional food factors are usually low, and many of these are difficult to be absorbed in the intact forms because of metabolization by biological processes during absorption. To gain adequate beneficial effects, it is therefore mandatory to know whether functional food factors are absorbed in sufficient quantity, and then reach target organs while maintaining beneficial effects. These are the reasons why the bioavailability of functional food factors has been well investigated using rodent models. Recently, many of the biological processes have been reported to follow diurnal rhythms recurring every 24 h. Therefore, absorption and metabolism of functional food factors influenced by the biological processes may vary with time of day. Consequently, the evaluation of the bioavailability of functional food factors using rodent models should take into consideration the timing of consumption. In this review, we provide a perspective overview of the diurnal rhythm of biological processes involved in the bioavailability of functional food factors, particularly flavonoids.

  2. Diurnal rhythmicity in biological processes involved in bioavailability of functional food factors

    PubMed Central

    Tsurusaki, Takashi; Sakakibara, Hiroyuki; Aoshima, Yoshiki; Yamazaki, Shunsuke; Sakono, Masanobu; Shimoi, Kayoko

    2013-01-01

    In the past few decades, many types of functional factors have been identified in dietary foods; for example, flavonoids are major groups widely distributed in the plant kingdom. However, the absorption rates of the functional food factors are usually low, and many of these are difficult to be absorbed in the intact forms because of metabolization by biological processes during absorption. To gain adequate beneficial effects, it is therefore mandatory to know whether functional food factors are absorbed in sufficient quantity, and then reach target organs while maintaining beneficial effects. These are the reasons why the bioavailability of functional food factors has been well investigated using rodent models. Recently, many of the biological processes have been reported to follow diurnal rhythms recurring every 24 h. Therefore, absorption and metabolism of functional food factors influenced by the biological processes may vary with time of day. Consequently, the evaluation of the bioavailability of functional food factors using rodent models should take into consideration the timing of consumption. In this review, we provide a perspective overview of the diurnal rhythm of biological processes involved in the bioavailability of functional food factors, particularly flavonoids. PMID:23704810

  3. Urban Biomining: Biological Extraction of Metals and Materials from Electronics Waste Using a Synthetic Biology Approach

    NASA Astrophysics Data System (ADS)

    Urbina-Navarrete, J.; Rothschild, L.

    2016-12-01

    End-of-life electronics waste (e-waste) containing toxic and valuable materials is a rapidly progressing human health and environmental issue. Using synthetic biology tools, we have developed a recycling method for e-waste. Our innovation is to use a recombinant version of a naturally-occurring silica-degrading enzyme to depolymerize the silica in metal- and glass- containing e-waste components, and subsequently, to use engineered bacterial surfaces to bind and separate metals from a solution. The bacteria with bound metals can then be used as "bio-ink" to print new circuits using a novel plasma jet electronics printing technology. Here, we present the results from our initial studies that focus on the specificity of metal-binding motifs for a cognate metal. The candidate motifs that show high affinity and specificity will be engineered into bacterial surfaces for downstream applications in biologically-mediated metal recycling. Since the chemistry and role of Cu in metalloproteins is relatively well-characterized, we are using Cu as a proxy to elucidate metal and biological ligand interactions with various metals in e-waste. We assess the binding parameters of 3 representative classes of Cu-binding motifs using isothermal titration calorimetry; 1) natural motifs found in metalloproteins, 2) consensus motifs, and 3) rationally designed peptides that are predicted, in silico, to bind Cu. Our results indicate that naturally-occurring motifs have relative high affinity and specificity for Cu (association constant for Cu Ka 104 M-1, Zn Ka 103 M-1) when competing ions are present in the aqueous milieu. However, motifs developed through rational design by applying quantum mechanical methods that take into account complexation energies of the elemental binding partners and molecular geometry of the cognate metal, not only show high affinity for the cognate metal (Cu Ka 106 M-1), but they show specificity and discrimination against other metal ions that would be

  4. Mechanics of Dynamic Needle Insertion into a Biological Material

    PubMed Central

    Mahvash, Mohsen; Dupont, Pierre E.

    2010-01-01

    During needle-based procedures, transitions between tissue layers often lead to rupture events that involve large forces and tissue deformations and produce uncontrollable crack extensions. In this paper, the mechanics of these rupture events is described, and the effect of insertion velocity on needle force, tissue deformation, and needle work is analyzed. Using the J integral method from fracture mechanics, rupture events are modeled as sudden crack extensions that occur when the release rate J of strain energy concentrated at the tip of the crack exceeds the fracture toughness of the material. It is shown that increasing the velocity of needle insertion will reduce the force of the rupture event when it increases the energy release rate. A nonlinear viscoelastic Kelvin model is then used to predict the relationship between the deformation of tissue and the rupture force at different velocities. The model predicts that rupture deformation and work asymptotically approach minimum values as needle velocity increases. Consequently, most of the benefit of using a higher needle velocity can be achieved using a finite velocity that is inversely proportional to the relaxation time of the tissue. Experiments confirm the analytical predictions with multilayered porcine cardiac tissue. PMID:19932986

  5. Mechanics of dynamic needle insertion into a biological material.

    PubMed

    Mahvash, Mohsen; Dupont, Pierre E

    2010-04-01

    During needle-based procedures, transitions between tissue layers often lead to rupture events that involve large forces and tissue deformations and produce uncontrollable crack extensions. In this paper, the mechanics of these rupture events is described, and the effect of insertion velocity on needle force, tissue deformation, and needle work is analyzed. Using the J integral method from fracture mechanics, rupture events are modeled as sudden crack extensions that occur when the release rate J of strain energy concentrated at the tip of the crack exceeds the fracture toughness of the material. It is shown that increasing the velocity of needle insertion will reduce the force of the rupture event when it increases the energy release rate. A nonlinear viscoelastic Kelvin model is then used to predict the relationship between the deformation of tissue and the rupture force at different velocities. The model predicts that rupture deformation and work asymptotically approach minimum values as needle velocity increases. Consequently, most of the benefit of using a higher needle velocity can be achieved using a finite velocity that is inversely proportional to the relaxation time of the tissue. Experiments confirm the analytical predictions with multilayered porcine cardiac tissue.

  6. Evolutionary Design in Biological Physics and Materials Science

    NASA Astrophysics Data System (ADS)

    Yang, M.; Park, J.-M.; Deem, M. W.

    In this chapter we provide a thorough discussion of the theoretical description of the multi-site approach to cancer vaccination. The discussion is somewhat demanding from a biological point of view. References to primary biological publications are given. A general reference on immunology is [1].

  7. Digital Learning Material for Model Building in Molecular Biology

    ERIC Educational Resources Information Center

    Aegerter-Wilmsen, Tinri; Janssen, Fred; Hartog, Rob; Bisseling, Ton

    2005-01-01

    Building models to describe processes forms an essential part of molecular biology research. However, in molecular biology curricula little attention is generally being paid to the development of this skill. In order to provide students the opportunity to improve their model building skills, we decided to develop a number of digital cases about…

  8. Digital Learning Material for Model Building in Molecular Biology

    ERIC Educational Resources Information Center

    Aegerter-Wilmsen, Tinri; Janssen, Fred; Hartog, Rob; Bisseling, Ton

    2005-01-01

    Building models to describe processes forms an essential part of molecular biology research. However, in molecular biology curricula little attention is generally being paid to the development of this skill. In order to provide students the opportunity to improve their model building skills, we decided to develop a number of digital cases about…

  9. Distinguishability of Biological Material Using Ultraviolet Multi-Spectral Fluorescence

    SciTech Connect

    Gray, P.C.; Heinen, R.J.; Rigdon, L.D.; Rosenthal, S.E.; Shokair, I.R.; Siragusa, G.R.; Tisone, G.C.; Wagner, J.S.

    1998-10-14

    Recent interest in the detection and analysis of biological samples by spectroscopic methods has led to questions concerning the degree of distinguishability and biological variability of the ultraviolet (W) fluorescent spectra from such complex samples. We show that the degree of distinguishability of such spectra is readily determined numerically.

  10. Acetylome analysis reveals the involvement of lysine acetylation in diverse biological processes in Phytophthora sojae

    PubMed Central

    Li, Delong; Lv, Binna; Tan, Lingling; Yang, Qianqian; Liang, Wenxing

    2016-01-01

    Lysine acetylation is a dynamic and highly conserved post-translational modification that plays an important regulatory role in almost every aspects of cell metabolism in both eukaryotes and prokaryotes. Phytophthora sojae is one of the most important plant pathogens due to its huge economic impact. However, to date, little is known about the functions of lysine acetylation in this Phytopthora. Here, we conducted a lysine acetylome in P. sojae. Overall, 2197 lysine acetylation sites in 1150 proteins were identified. The modified proteins are involved in diverse biological processes and are localized to multiple cellular compartments. Importantly, 7 proteins involved in the pathogenicity or the secretion pathway of P. sojae were found to be acetylated. These data provide the first comprehensive view of the acetylome of P. sojae and serve as an important resource for functional analysis of lysine acetylation in plant pathogens. PMID:27412925

  11. Acetylome analysis reveals the involvement of lysine acetylation in diverse biological processes in Phytophthora sojae.

    PubMed

    Li, Delong; Lv, Binna; Tan, Lingling; Yang, Qianqian; Liang, Wenxing

    2016-07-14

    Lysine acetylation is a dynamic and highly conserved post-translational modification that plays an important regulatory role in almost every aspects of cell metabolism in both eukaryotes and prokaryotes. Phytophthora sojae is one of the most important plant pathogens due to its huge economic impact. However, to date, little is known about the functions of lysine acetylation in this Phytopthora. Here, we conducted a lysine acetylome in P. sojae. Overall, 2197 lysine acetylation sites in 1150 proteins were identified. The modified proteins are involved in diverse biological processes and are localized to multiple cellular compartments. Importantly, 7 proteins involved in the pathogenicity or the secretion pathway of P. sojae were found to be acetylated. These data provide the first comprehensive view of the acetylome of P. sojae and serve as an important resource for functional analysis of lysine acetylation in plant pathogens.

  12. Chemical and Biological Barrier Materials for Collective Protection Shelters

    DTIC Science & Technology

    2006-01-01

    fall into several categories including butyl rubbers , chlorinated aliphatics, and fluorinated polymers. The degree of protection these barrier materials...M51 barrier material. These candidate materials consisted of butyl nylons, Teflon/Kevlar, Tedlar/vinyl coated Dacron, Teflon/Nomex, and...Teflon/Kevlar material was chosen based on its superior CB resistance, ability to be decontaminated, weight, mechanical properties, and the ability to

  13. Chemical and Biological Barrier Materials for Collective Protection

    DTIC Science & Technology

    2003-11-19

    Directorate ColPro Shelters *Heavy *Cumbersome *High Logistic Burden *Very Expensive Barrier Materials * Butyl Rubbers *Chlorinated Aliphatics *Fluorinated...Natick Soldier Center Slide 17 • RDECOM Collective Protection Directorate NANOCOMPOSITE FILMS Background ! Novel patented nanotechnology is based on the...Material -Thickness -Inertness -Condition SEVERAL COMPONENTS # Base Material or Substrate *Provides Physical Properties #Impermeable Barrier **Provides CB

  14. Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.

    DOEpatents

    Alfano, Robert R.; Wang, Wubao

    2003-05-06

    A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. A low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic transaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively.

  15. Trends in United States Biological Materials Oversight and Institutional Biosafety Committees

    ERIC Educational Resources Information Center

    Jenkins, Chris

    2014-01-01

    Biological materials oversight in life sciences research in the United States is a challenging endeavor for institutions and the scientific, regulatory compliance, and federal communities. In order to assess biological materials oversight at Institutional Biosafety Committees (IBCs) registered with the United States National Institutes of Health,…

  16. Trends in United States Biological Materials Oversight and Institutional Biosafety Committees

    ERIC Educational Resources Information Center

    Jenkins, Chris

    2014-01-01

    Biological materials oversight in life sciences research in the United States is a challenging endeavor for institutions and the scientific, regulatory compliance, and federal communities. In order to assess biological materials oversight at Institutional Biosafety Committees (IBCs) registered with the United States National Institutes of Health,…

  17. A comparison of methods for the determination of sound velocity in biological materials: a case study.

    PubMed

    Nowak, Konrad W; Markowski, Marek

    2013-07-01

    Non-destructive ultrasonic methods for testing biological materials are applied in medicine as well as in food engineering to determine the physical parameters and the quality of agricultural products and raw materials such as meat. The purpose of this work was to identify the simplest and the most accurate of five methods for sound velocity determination across the fibers of the porcine longissimus dorsi muscle. The through-transmission technique (TT) was used for ultrasound signal acquisition with 2MHz transducers. The first two methods (M1, M2) are based on the acquisition of a single ultrasound signal in the analyzed material, another two methods (M3, M4) rely on the acquisition of two ultrasound signals in samples with different thicknesses (two-distance method) and the last method (M5) involves the acquisition of a single ultrasound signal in the analyzed material and the acquisition of a single ultrasound signal in distilled water at the same distance between ultrasonic transducers (relative method). The results were processed by the nonparametric Kruskal-Wallis test and compared with published data. The mean values of sound velocity obtained with the use of the above methods in pork samples at post-storage, room and vital temperatures were as follows: method M1-1549.2/1581.7/1597.4m/s, method M2-1477.7/1509.8/1597.4m/s, method M3-1552.0/1599.0/1623.3m/s, method M4-1557.4/1598.3/1623.6m/s, method M5-1554.3/1583.7/1598m/s. The experiment indicates that the choice of method for determining sound velocity significantly influences the results. Two of the five analyzed methods (namely M3 and M4), which involved measurements of the time of sound wave propagation through samples of the same material with varied thickness, produced velocity values most consistent with published data.

  18. Analyses of Hazardous Substances in Biological Materials: Volume 5

    NASA Astrophysics Data System (ADS)

    Angerer, Jürgen; Schaller, Karl-Heinz

    1996-10-01

    Biological monitoring has proved extremely valuable in assessing the health risk of persons exposed to hazardous chemical substances in the environment or at the workplace. The chemical compounds are generally determined in body fluids. They are present in trace or ultratrace concentrations. Specific and extremely sensitive methods of chemical analysis are necessary to separate these substances from the biological matrix and to determine them precisely. This volume contains 12 standardized analytical methods. All methods are suitable for routine use. They meet exceptionally high standards of reliability and reproducibility and are in accordance with 'Good Laboratory Practice'. Considerable emphasis is placed on sample collection methods and on analytical quality control. One gereral chapter introduces biological monitoring using ICP-spectroscopy.

  19. Three-Dimensional Reconstruction of Macroscopic Features in Biological Materials

    NASA Astrophysics Data System (ADS)

    Krumnikl, Michal; Sojka, Eduard; Gaura, Jan; Motyka, Oldřich

    This paper covers the topic of three dimensional reconstruction of small textureless formations usually found in biological samples. Generally used reconstructing algorithms do not provide sufficient accuracy for surface analysis. In order to achieve better results, combined strategy was developed, linking stereo matching algorithms with monocular depth cues such as depth from focus and depth from illumination.

  20. Biological effects of menadione photochemistry: effects of menadione on biological systems may not involve classical oxidant production.

    PubMed Central

    McCormick, M L; Denning, G M; Reszka, K J; Bilski, P; Buettner, G R; Rasmussen, G T; Railsback, M A; Britigan, B E

    2000-01-01

    Because cell-mediated reduction of menadione leads to the generation of reactive oxygen species (ROS), this quinone is widely used to investigate the effects of ROS on cellular functions. We report that A549 human lung epithelial cells exposed to menadione demonstrate a dose-dependent increase in both intracellular calcium ([Ca(2+)](i)) and ROS formation. The concentrations of menadione required to initiate these two events are markedly different, with ROS detection requiring higher levels of menadione. Modulators of antioxidant defences (e.g. buthionine sulphoximine, 3-amino-1,2,4-triazole) have little effect on the [Ca(2+)](i) response to menadione, suggesting that ROS formation does not account for menadione-dependent alterations in [Ca(2+)](i). Additional evidence suggests that menadione photochemistry may be responsible for the observed [Ca(2+)](i) effects. Specifically: (a) EPR studies with the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) show that light exposure (maximum effect at 340 nm) stimulates menadione-dependent formation of the DMPO/(.)OH spin adduct that was not sensitive to antioxidant interventions; (b) DMPO inhibits menadione and light-dependent increases in [Ca(2+)](i); and (c) light (maximum effect at 340 nm) augments the deleterious effects of menadione on cell viability as determined by (51)Cr release. These photo effects do not appear to involve formation of singlet oxygen by menadione, but rather are the result of the oxidizing chemistry initiated by menadione in the triplet state. This work demonstrates that menadione species generated by photo-irradiation can exert biological effects on cellular functions and points to the potential importance of photochemistry in studies of menadione-mediated cell damage. PMID:10970795

  1. [Biological decontamination of the imprints obtained from different dental materials].

    PubMed

    Brekhlichuk, P P; Petrov, V O; Bati, V V; Levchuk, O B; Boĭko, N V

    2013-01-01

    Microbiological contamination of the imprints made of alginate ("Ypeen") and silicone material ("Speedex") with and without the correction supplement has been investigated. Streptococcus and Staphylococcus have been estimated to be the most survivable species on the imprint surface, however their concentration differ depending on the type of imprints' material. The strains resistant to antibiotics dominated among all the isolated microorganisms. Bacterial preparations based on Bacillus - Biosporin and Subalin and some extracts of edible plants, fruits and berries can be used in dentistry for the decontamination of imprints obtained by the use of different materials.

  2. An outlook review: mechanochromic materials and their potential for biological and healthcare applications.

    PubMed

    Jiang, Ying

    2014-12-01

    Macroscopic mechanical perturbations have been observed to result in optical changes for certain compounds and composite materials. This phenomenon could originate from chemical and physical changes across various length scales, from the rearrangement of chemical bonds to alteration of molecular domains on the order of several hundred nanometers. This review classifies the mechanisms and surveys of how each class of mechanochromic materials has been, and can potentially be applied in biological and healthcare innovations. The study of cellular and molecular responses to mechanical forces in biological systems is an emerging field; there is potential in applying mechanochromic principles and material systems for probing biological systems. On the other hand, application of mechanochromic materials for medical and healthcare consumer products has been described in a wide variety of concepts and inventions. It is hopeful that further understanding of mechanochromism and material innovations would initiate concrete, impactful studies in biological systems soon.

  3. Bioreceptivity evaluation of cementitious materials designed to stimulate biological growth.

    PubMed

    Manso, Sandra; De Muynck, Willem; Segura, Ignacio; Aguado, Antonio; Steppe, Kathy; Boon, Nico; De Belie, Nele

    2014-05-15

    Ordinary Portland cement (OPC), the most used binder in construction, presents some disadvantages in terms of pollution (CO2 emissions) and visual impact. For this reason, green roofs and façades have gain considerable attention in the last decade as a way to integrate nature in cities. These systems, however, suffer from high initial and maintenance costs. An alternative strategy to obtain green facades is the direct natural colonisation of the cementitious construction materials constituting the wall, a phenomenon governed by the bioreceptivity of such material. This work aims at assessing the suitability of magnesium phosphate cement (MPC) materials to allow a rapid natural colonisation taking carbonated OPC samples as a reference material. For that, the aggregate size, the w/c ratio and the amount of cement paste of mortars made of both binders were modified. The assessment of the different bioreceptivities was conducted by means of an accelerated algal fouling test. MPC samples exhibited a faster fouling compared to OPC samples, which could be mainly attributed to the lower pH of the MPC binder. In addition to the binder, the fouling rate was governed by the roughness and the porosity of the material. MPC mortar with moderate porosity and roughness appears to be the most feasible material to be used for the development of green concrete walls. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Functional dissection of protein complexes involved in yeast chromosome biology using a genetic interaction map.

    PubMed

    Collins, Sean R; Miller, Kyle M; Maas, Nancy L; Roguev, Assen; Fillingham, Jeffrey; Chu, Clement S; Schuldiner, Maya; Gebbia, Marinella; Recht, Judith; Shales, Michael; Ding, Huiming; Xu, Hong; Han, Junhong; Ingvarsdottir, Kristin; Cheng, Benjamin; Andrews, Brenda; Boone, Charles; Berger, Shelley L; Hieter, Phil; Zhang, Zhiguo; Brown, Grant W; Ingles, C James; Emili, Andrew; Allis, C David; Toczyski, David P; Weissman, Jonathan S; Greenblatt, Jack F; Krogan, Nevan J

    2007-04-12

    Defining the functional relationships between proteins is critical for understanding virtually all aspects of cell biology. Large-scale identification of protein complexes has provided one important step towards this goal; however, even knowledge of the stoichiometry, affinity and lifetime of every protein-protein interaction would not reveal the functional relationships between and within such complexes. Genetic interactions can provide functional information that is largely invisible to protein-protein interaction data sets. Here we present an epistatic miniarray profile (E-MAP) consisting of quantitative pairwise measurements of the genetic interactions between 743 Saccharomyces cerevisiae genes involved in various aspects of chromosome biology (including DNA replication/repair, chromatid segregation and transcriptional regulation). This E-MAP reveals that physical interactions fall into two well-represented classes distinguished by whether or not the individual proteins act coherently to carry out a common function. Thus, genetic interaction data make it possible to dissect functionally multi-protein complexes, including Mediator, and to organize distinct protein complexes into pathways. In one pathway defined here, we show that Rtt109 is the founding member of a novel class of histone acetyltransferases responsible for Asf1-dependent acetylation of histone H3 on lysine 56. This modification, in turn, enables a ubiquitin ligase complex containing the cullin Rtt101 to ensure genomic integrity during DNA replication.

  5. Raman and Surface Enhanced Raman of Biological Material

    DTIC Science & Technology

    2004-12-01

    peaks being identified that were previously masked by the background. 500 1000 1500 2000 2500 3000 Raman Shift (cm-1) Yersinia rhodei Pantoea ... Pantoea agglomerans, Brucella neotomae, and Yersinia rhodei. The highlighted regions show characteristic biological vibrations consisting of Amide I, II...Raman Shift (cm-1) 500 1000 1500 2000 2500 3000 Amide I, II, & III vibrations Phenyl vibrations CH vibrations Pantoea agglomerans Brucella neotomae

  6. Mechanisms of Microwave Induced Damage in Biologic Materials

    DTIC Science & Technology

    1990-01-01

    the PhD thesis research of Babak Saif, a graduate student in our laboratory. For DNA solutions of similar DNA concentration he studied the effect of...6260 Research & Development CommanI 8C. ADDRESS (City, State, and ZIP Code) 10. SOURCE OF FUNDING NUMBERS Fort Detrick PROGRAM PROJECT TASK WORK UNIT...these are (1) mathematical model- ing studies, (2) experimental spectroscopic studies, (3) engineering design research , and (4) experimental biological

  7. Environmental Durability of Materials and Bonded Joints Involving Fiber Reinforced Polymers and Concerte

    NASA Astrophysics Data System (ADS)

    Gavari, Mahdi Mansouri; rad, A. Yazdi; Gavari, Mohsen Mansouri

    2008-08-01

    This paper describes the research work undertaken to evaluate the performance of materials and bonded joints involving Fibre Reinforced Polymers (FRPs) and concrete. Experimental variables ncluded polymer composite materials, test methods and environmental test conditions. Tensile and flexural tests were carried out to determine short term and long term environmental durability of composite materials. Single lap shear, a modified wedge cleavage and pull-off adhesion tests were used to study the performance of bonded joints. It is shown the tensile strength of composite materials can be affected after exposure to hot/humid conditions. The performance of stressed single lap joints was also affected by hot/humid conditions.

  8. Expression-based network biology identifies immune-related functional modules involved in plant defense.

    PubMed

    Tully, Joel P; Hill, Aubrey E; Ahmed, Hadia M R; Whitley, Ryan; Skjellum, Anthony; Mukhtar, M Shahid

    2014-06-03

    Plants respond to diverse environmental cues including microbial perturbations by coordinated regulation of thousands of genes. These intricate transcriptional regulatory interactions depend on the recognition of specific promoter sequences by regulatory transcription factors. The combinatorial and cooperative action of multiple transcription factors defines a regulatory network that enables plant cells to respond to distinct biological signals. The identification of immune-related modules in large-scale transcriptional regulatory networks can reveal the mechanisms by which exposure to a pathogen elicits a precise phenotypic immune response. We have generated a large-scale immune co-expression network using a comprehensive set of Arabidopsis thaliana (hereafter Arabidopsis) transcriptomic data, which consists of a wide spectrum of immune responses to pathogens or pathogen-mimicking stimuli treatments. We employed both linear and non-linear models to generate Arabidopsis immune co-expression regulatory (AICR) network. We computed network topological properties and ascertained that this newly constructed immune network is densely connected, possesses hubs, exhibits high modularity, and displays hallmarks of a "real" biological network. We partitioned the network and identified 156 novel modules related to immune functions. Gene Ontology (GO) enrichment analyses provided insight into the key biological processes involved in determining finely tuned immune responses. We also developed novel software called OCCEAN (One Click Cis-regulatory Elements ANalysis) to discover statistically enriched promoter elements in the upstream regulatory regions of Arabidopsis at a whole genome level. We demonstrated that OCCEAN exhibits higher precision than the existing promoter element discovery tools. In light of known and newly discovered cis-regulatory elements, we evaluated biological significance of two key immune-related functional modules and proposed mechanism(s) to explain

  9. Biological control of bacterial wilt in Arabidopsis thaliana involves abscissic acid signalling.

    PubMed

    Feng, Dong Xin; Tasset, Céline; Hanemian, Mathieu; Barlet, Xavier; Hu, Jian; Trémousaygue, Dominique; Deslandes, Laurent; Marco, Yves

    2012-06-01

    Means to control bacterial wilt caused by the phytopathogenic root bacteria Ralstonia solanacearum are limited. Mutants in a large cluster of genes (hrp) involved in the pathogenicity of R. solanacearum were successfully used in a previous study as endophytic biocontrol agents in challenge inoculation experiments on tomato. However, the molecular mechanisms controlling this resistance remained unknown. We developed a protection assay using Arabidopsis thaliana as a model plant and analyzed the events underlying the biological control by genetic, transcriptomic and molecular approaches. High protection rates associated with a significant decrease in the multiplication of R. solanacearum were observed in plants pre-inoculated with a ΔhrpB mutant strain. Neither salicylic acid, nor jasmonic acid/ethylene played a role in the establishment of this resistance. Microarray analysis showed that 26% of the up-regulated genes in protected plants are involved in the biosynthesis and signalling of abscissic acid (ABA). In addition 21% of these genes are constitutively expressed in the irregular xylem cellulose synthase mutants (irx), which present a high level of resistance to R. solanacearum. We propose that inoculation with the ΔhrpB mutant strain generates a hostile environment for subsequent plant colonization by a virulent strain of R. solanacearum.

  10. Redox chemistry of molybdenum in natural waters and its involvement in biological evolution

    PubMed Central

    Wang, Deli

    2012-01-01

    The transition element molybdenum (Mo) possesses diverse valances (+II to +VI), and is involved in forming cofactors in more than 60 enzymes in biology. Redox switching of the element in these enzymes catalyzes a series of metabolic reactions in both prokaryotes and eukaryotes, and the element therefore plays a fundamental role in the global carbon, nitrogen, and sulfur cycling. In the present oxygenated waters, oxidized Mo(VI) predominates thermodynamically, whilst reduced Mo species are mainly confined within specific niches including cytoplasm. Only recently has the reduced Mo(V) been separated from Mo(VI) in sulfidic mats and even in some reducing waters. Given the presence of reduced Mo(V) in contemporary anaerobic habitats, it seems that reduced Mo species were present in the ancient reducing ocean (probably under both ferruginous and sulfidic conditions), prompting the involvement of Mo in enzymes including nitrogenase and nitrate reductase. During the global transition to oxic conditions, reduced Mo species were constrained to specific anaerobic habitats, and efficient uptake systems of oxidized Mo(VI) became a selective advantage for current prokaryotic and eukaryotic cells. Some prokaryotes are still able to directly utilize reduced Mo if any exists in ambient environments. In total, this mini-review describes the redox chemistry and biogeochemistry of Mo over the Earth’s history. PMID:23267355

  11. Redox chemistry of molybdenum in natural waters and its involvement in biological evolution.

    PubMed

    Wang, Deli

    2012-01-01

    The transition element molybdenum (Mo) possesses diverse valances (+II to +VI), and is involved in forming cofactors in more than 60 enzymes in biology. Redox switching of the element in these enzymes catalyzes a series of metabolic reactions in both prokaryotes and eukaryotes, and the element therefore plays a fundamental role in the global carbon, nitrogen, and sulfur cycling. In the present oxygenated waters, oxidized Mo(VI) predominates thermodynamically, whilst reduced Mo species are mainly confined within specific niches including cytoplasm. Only recently has the reduced Mo(V) been separated from Mo(VI) in sulfidic mats and even in some reducing waters. Given the presence of reduced Mo(V) in contemporary anaerobic habitats, it seems that reduced Mo species were present in the ancient reducing ocean (probably under both ferruginous and sulfidic conditions), prompting the involvement of Mo in enzymes including nitrogenase and nitrate reductase. During the global transition to oxic conditions, reduced Mo species were constrained to specific anaerobic habitats, and efficient uptake systems of oxidized Mo(VI) became a selective advantage for current prokaryotic and eukaryotic cells. Some prokaryotes are still able to directly utilize reduced Mo if any exists in ambient environments. In total, this mini-review describes the redox chemistry and biogeochemistry of Mo over the Earth's history.

  12. Using Fourier transform IR spectroscopy to analyze biological materials

    PubMed Central

    Baker, Matthew J; Trevisan, Júlio; Bassan, Paul; Bhargava, Rohit; Butler, Holly J; Dorling, Konrad M; Fielden, Peter R; Fogarty, Simon W; Fullwood, Nigel J; Heys, Kelly A; Hughes, Caryn; Lasch, Peter; Martin-Hirsch, Pierre L; Obinaju, Blessing; Sockalingum, Ganesh D; Sulé-Suso, Josep; Strong, Rebecca J; Walsh, Michael J; Wood, Bayden R; Gardner, Peter; Martin, Francis L

    2015-01-01

    IR spectroscopy is an excellent method for biological analyses. It enables the nonperturbative, label-free extraction of biochemical information and images toward diagnosis and the assessment of cell functionality. Although not strictly microscopy in the conventional sense, it allows the construction of images of tissue or cell architecture by the passing of spectral data through a variety of computational algorithms. Because such images are constructed from fingerprint spectra, the notion is that they can be an objective reflection of the underlying health status of the analyzed sample. One of the major difficulties in the field has been determining a consensus on spectral pre-processing and data analysis. This manuscript brings together as coauthors some of the leaders in this field to allow the standardization of methods and procedures for adapting a multistage approach to a methodology that can be applied to a variety of cell biological questions or used within a clinical setting for disease screening or diagnosis. We describe a protocol for collecting IR spectra and images from biological samples (e.g., fixed cytology and tissue sections, live cells or biofluids) that assesses the instrumental options available, appropriate sample preparation, different sampling modes as well as important advances in spectral data acquisition. After acquisition, data processing consists of a sequence of steps including quality control, spectral pre-processing, feature extraction and classification of the supervised or unsupervised type. A typical experiment can be completed and analyzed within hours. Example results are presented on the use of IR spectra combined with multivariate data processing. PMID:24992094

  13. Using Fourier transform IR spectroscopy to analyze biological materials.

    PubMed

    Baker, Matthew J; Trevisan, Júlio; Bassan, Paul; Bhargava, Rohit; Butler, Holly J; Dorling, Konrad M; Fielden, Peter R; Fogarty, Simon W; Fullwood, Nigel J; Heys, Kelly A; Hughes, Caryn; Lasch, Peter; Martin-Hirsch, Pierre L; Obinaju, Blessing; Sockalingum, Ganesh D; Sulé-Suso, Josep; Strong, Rebecca J; Walsh, Michael J; Wood, Bayden R; Gardner, Peter; Martin, Francis L

    2014-08-01

    IR spectroscopy is an excellent method for biological analyses. It enables the nonperturbative, label-free extraction of biochemical information and images toward diagnosis and the assessment of cell functionality. Although not strictly microscopy in the conventional sense, it allows the construction of images of tissue or cell architecture by the passing of spectral data through a variety of computational algorithms. Because such images are constructed from fingerprint spectra, the notion is that they can be an objective reflection of the underlying health status of the analyzed sample. One of the major difficulties in the field has been determining a consensus on spectral pre-processing and data analysis. This manuscript brings together as coauthors some of the leaders in this field to allow the standardization of methods and procedures for adapting a multistage approach to a methodology that can be applied to a variety of cell biological questions or used within a clinical setting for disease screening or diagnosis. We describe a protocol for collecting IR spectra and images from biological samples (e.g., fixed cytology and tissue sections, live cells or biofluids) that assesses the instrumental options available, appropriate sample preparation, different sampling modes as well as important advances in spectral data acquisition. After acquisition, data processing consists of a sequence of steps including quality control, spectral pre-processing, feature extraction and classification of the supervised or unsupervised type. A typical experiment can be completed and analyzed within hours. Example results are presented on the use of IR spectra combined with multivariate data processing.

  14. Modulating material interfaces through biologically-inspired intermediates

    NASA Astrophysics Data System (ADS)

    Hazar, Melis; Steward, Robert L.; Chang, Chia-Jung; Orndoff, Cynthia J.; Zeng, Yukai; Ho, Mon-Shu; LeDuc, Philip R.; Cheng, Chao-Min

    2011-12-01

    This letter describes the control of molecular filament organization through biologically inspired intermediates, enabling us to obtain large-area regular nanopatterns. We first studied cultured single filamentous actins on an unmodified glass surface (hydrophilic surface) and introduced myosin-II to modify the control. We then utilized an inorganic salt crystallization approach on the response of these two proteins, actin filament and myosin-II, to analyze the resultant spatially localized patterns. Through the utilization of myosin-II and the salt crystallization approach, we were able to induce the filament orientation of 63°; while without myosin-II, we induced an orientation of 90°.

  15. Rapid Prototyping of Biological Materials for In-Space Applications

    NASA Technical Reports Server (NTRS)

    Frazier, Natalie

    2005-01-01

    The topics include: 1) Why is this technology needed? 2) In-Situ Fabrication and Repair (ISFR) and In-Situ Resource Utilization (ISRU); 3) Multi-Material Fabricator; 4) Medical Products; 5) Bioplotter; 6) Closing Remarks; and 7) Additional Information.

  16. Using biological inspiration to engineer functional nanostructured materials.

    PubMed

    Wendell, David W; Patti, Jordan; Montemagno, Carlo D

    2006-11-01

    Humans have always looked to nature for design inspiration, and material design on the molecular level is no different. Here we explore how this idea applies to nanoscale biomimicry, specifically examining both recent advances and our own work on engineering lipid and polymer membrane systems with cellular processes.

  17. An ab-initio Computational Method to Determine Dielectric Properties of Biological Materials

    PubMed Central

    Abeyrathne, Chathurika D.; Halgamuge, Malka N.; Farrell, Peter M.; Skafidas, Efstratios

    2013-01-01

    Frequency dependent dielectric properties are important for understanding the structure and dynamics of biological materials. These properties can be used to study underlying biological processes such as changes in the concentration of biological materials, and the formation of chemical species. Computer simulations can be used to determine dielectric properties and atomic details inaccessible via experimental methods. In this paper, a unified theory utilizing molecular dynamics and density functional theory is presented that is able to determine the frequency dependent dielectric properties of biological materials in an aqueous solution from their molecular structure alone. The proposed method, which uses reaction field approximations, does not require a prior knowledge of the static dielectric constant of the material. The dielectric properties obtained from our method agree well with experimental values presented in the literature. PMID:23652459

  18. Alternatives of informed consent for storage and use of human biological material for research purposes: Brazilian regulation.

    PubMed

    Marodin, Gabriela; França, Paulo Henrique Condeixa de; Salgueiro, Jennifer Braathen; Motta, Marcia Luz da; Tannous, Gysélle Saddi; Lopes, Anibal Gil

    2014-12-01

    Informed consent is recognized as a primary ethical requirement to conduct research involving humans. In the investigations with the use of human biological material, informed consent (IC) assumes a differentiated condition on account of the many future possibilities. This work presents suitable alternatives for IC regarding the storage and use of human biological material in research, according to new Brazilian regulations. Both norms - Resolution 441/11 of the National Health Council, approved on 12 May 2011, and Ordinance 2.201 (NATIONAL GUIDELINES FOR BIOREPOSITORIES AND BIOBANKS OF HUMAN BIOLOGICAL MATERIAL FOR RESEARCH PURPOSE) of the Brazil Ministry of Health, approved on 14 September 2011 - state that the consent of subjects for the collection, storage and use of samples stored in Biobanks is necessarily established by means of a Free and Informed Consent Form (ICF). In order to obtain individual and formal statements, this form should contain the following two mutually exclusive options: an explanation about the use of the stored material in each research study, and the need for new consent or the waiver thereof when the material is used for a new study. On the other hand, ICF suitable for Biorepositories must be exclusive and related to specific research. Although Brazilian and international regulations identify the main aspects to be included in the IC, efforts are still necessary to improve the consent process, so that the document will become a bond of trust between subject and researcher. © 2012 John Wiley & Sons Ltd.

  19. Impacts of Insufficient Instructional Materials on Teaching Biology: Higher Education Systems in Focus

    ERIC Educational Resources Information Center

    Edessa, Sutuma

    2017-01-01

    The purpose of this study was to assess and determine impacts of insufficient instructional materials and ineffective lesson delivery methods on teaching in biology higher education. The participants of this study were 60 trainees who graduated in Bachelor of Sciences from eight public universities in majoring biology. Data for the study was…

  20. Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.

    DOEpatents

    Alfano, Robert R.; Wang, Wubao

    2000-11-21

    A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. In accordance with the teachings of the invention, a low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic tansaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively. For example, it may also be used to diagnose diseases associated with the concentration of Raman-active constituents in urine, lymph and saliva It may be used to identify cancer in the breast, cervix, uterus, ovaries and the like by measuring the fingerprint excitation Raman spectra of these tissues. It may also be used to reveal the growing of tumors or cancers by measuring the levels of nitric oxide in tissue.

  1. [Visual representation of biological structures in teaching material].

    PubMed

    Morato, M A; Struchiner, M; Bordoni, E; Ricciardi, R M

    1998-01-01

    Parameters must be defined for presenting and handling scientific information presented in the form of teaching materials. Through library research and consultations with specialists in the health sciences and in graphic arts and design, this study undertook a comparative description of the first examples of scientific illustrations of anatomy and the evolution of visual representations of knowledge on the cell. The study includes significant examples of illustrations which served as elements of analysis.

  2. Low cost materials of construction for biological processes: Proceedings

    SciTech Connect

    Not Available

    1993-05-13

    The workshop was held, May 1993 in conjunction with the 15th Symposium on Biotechnology for Fuels and Chemicals. The purpose of this workshop was to present information on the biomass to ethanol process in the context of materials selection and through presentation and discussion, identify promising avenues for future research. Six technical presentations were grouped into two sessions: process assessment and technology assessment. In the process assessment session, the group felt that the pretreatment area would require the most extensive materials research due the complex chemical, physical and thermal environment. Discussion centered around the possibility of metals being leached into the process stream and their effect on the fermentation mechanics. Linings were a strong option for pretreatment assuming the economics were favorable. Fermentation was considered an important area for research also, due to the unique complex of compounds and dual phases present. Erosion in feedstock handling equipment was identified as a minor concern. In the technology assessment session, methodologies in corrosion analysis were presented in addition to an overview of current coatings/linings technology. Widely practiced testing strategies, including ASTM methods, as well as novel procedures for micro-analysis of corrosion were discussed. Various coatings and linings, including polymers and ceramics, were introduced. The prevailing recommendations for testing included keeping the testing simple until the problem warranted a more detailed approach and developing standardized testing procedures to ensure the data was reproducible and applicable. The need to evaluate currently available materials such as coatings/linings, carbon/stainless steels, or fiberglass reinforced plastic was emphasized. It was agreed that economic evaluation of each material candidate must be an integral part of any research plan.

  3. Impact Debris With Biological Material In The Inner Solar System

    NASA Astrophysics Data System (ADS)

    Chavez, Carlos E.; Reyes-Ruiz, M.

    2010-10-01

    Here we revisited the article published by Gladman et al. 2005 in which is assumed that asteroidal and cometary impacts onto Earth can liberate material containing viable microorganisms, we studied the subsequent distribution of the escaping impact ejecta throughout the inner Solar System on time scales of 30,000 years. We reproduce their results and found that there are impacts with Jupiter too, that is relevant since the satellites Europa and Ganymede are believed to have liquid oceans below their surfaces.

  4. Modeling of a biological material nacre: Waviness stiffness model.

    PubMed

    Al-Maskari, N S; McAdams, D A; Reddy, J N

    2017-01-01

    Nacre is a tough yet stiff natural composite composed of microscopic mineral polygonal tablets bonded by a tough biopolymer. The high stiffness of nacre is known to be due to its high mineral content. However, the remarkable toughness of nacre is explained by its ability to deform past a yield point and develop large inelastic strain over a large volume around defects and cracks. The high strain is mainly due to sliding and waviness of the tablets. Mimicking nacre's remarkable properties, to date, is still a challenge due in part to fabrication challenges as well as a lack of models that can predict its properties or properties of a bulk material given specific constituent materials and material structure. Previous attempts to create analytical models for nacre include tablet sliding but don't account for the waviness of the tablets. In this work, a mathematical model is proposed to account for the waviness of the tablet. Using this model, a better prediction of the elastic modulus is obtained that agrees with experimental values found in the literature. In addition, the waviness angle can be predicted which is within the recommended range. Having a good representative model aids in designing a bio-mimicked nacre.

  5. [Materials for the substantiation of the biological MAC of benzene].

    PubMed

    Ulanova, I P; Avilova, G G; Karpukhina, E A; Karimova, L K; Boĭko, V I; Makar'eva, L M

    1990-09-01

    Relatively great amount of benzene-originated phenol, the presence of a definite relationship between phenol amount in the urine and benzene content in the air indicate that it is reasonable to use a phenol sample as an exposure test. To determine the intensity of benzene exposure, data on phenol content in the urine of people working at some big-tonnage enterprises has been analyzed. On the basis of the national and foreign literature data on the correlation between the phenol urine concentration and the level of benzene exposure a regression equation was deduced, which has made it possible to calculate phenol content in the urine on the level of average working day benzene concentration adopted in the USSR. This value equals 15 mg/l, which was proposed as a biological benzene MAC.

  6. Analysis of biological materials using a nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Mulware, Stephen Juma

    The use of nuclear microprobe techniques including: Particle induced x-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) for elemental analysis and quantitative elemental imaging of biological samples is especially useful in biological and biomedical research because of its high sensitivity for physiologically important trace elements or toxic heavy metals. The nuclear microprobe of the Ion Beam Modification and Analysis Laboratory (IBMAL) has been used to study the enhancement in metal uptake of two different plants. The roots of corn (Zea mays) have been analyzed to study the enhancement of iron uptake by adding Fe (II) or Fe(III) of different concentrations to the germinating medium of the seeds. The Fe uptake enhancement effect produced by lacing the germinating medium with carbon nanotubes has also been investigated. The aim of this investigation is to ensure not only high crop yield but also Fe-rich food products especially from calcareous soil which covers 30% of world's agricultural land. The result will help reduce iron deficiency anemia, which has been identified as the leading nutritional disorder especially in developing countries by the World Health Organization. For the second plant, Mexican marigold (Tagetes erecta ), the effect of an arbuscular mycorrhizal fungi (Glomus intraradices ) for the improvement of lead phytoremediation of lead contaminated soil has been investigated. Phytoremediation provides an environmentally safe technique of removing toxic heavy metals (like lead), which can find their way into human food, from lands contaminated by human activities like mining or by natural disasters like earthquakes. The roots of Mexican marigold have been analyzed to study the role of arbuscular mycorrhizal fungi in enhancement of lead uptake from the contaminated rhizosphere.

  7. On the relationship between indentation hardness and modulus, and the damage resistance of biological materials.

    PubMed

    Labonte, David; Lenz, Anne-Kristin; Oyen, Michelle L

    2017-07-15

    The remarkable mechanical performance of biological materials is based on intricate structure-function relationships. Nanoindentation has become the primary tool for characterising biological materials, as it allows to relate structural changes to variations in mechanical properties on small scales. However, the respective theoretical background and associated interpretation of the parameters measured via indentation derives largely from research on 'traditional' engineering materials such as metals or ceramics. Here, we discuss the functional relevance of indentation hardness in biological materials by presenting a meta-analysis of its relationship with indentation modulus. Across seven orders of magnitude, indentation hardness was directly proportional to indentation modulus. Using a lumped parameter model to deconvolute indentation hardness into components arising from reversible and irreversible deformation, we establish criteria which allow to interpret differences in indentation hardness across or within biological materials. The ratio between hardness and modulus arises as a key parameter, which is related to the ratio between irreversible and reversible deformation during indentation, the material's yield strength, and the resistance to irreversible deformation, a material property which represents the energy required to create a unit volume of purely irreversible deformation. Indentation hardness generally increases upon material dehydration, however to a larger extent than expected from accompanying changes in indentation modulus, indicating that water acts as a 'plasticiser'. A detailed discussion of the role of indentation hardness, modulus and toughness in damage control during sharp or blunt indentation yields comprehensive guidelines for a performance-based ranking of biological materials, and suggests that quasi-plastic deformation is a frequent yet poorly understood damage mode, highlighting an important area of future research. Instrumented

  8. Comparison of the biological NH3 removal characteristics among four inorganic packing materials.

    PubMed

    Hirai, M; Kamamoto, M; Yani, M; Shoda, M

    2001-01-01

    Four inorganic packing materials were evaluated in terms of their availability as a packing material of a packed tower deodorization apparatus (biofilter) from the viewpoints of biological NH3 removal characteristics and some physical properties. Porous ceramics (A), calcinated cristobalite (B), calcinated and formed obsidian (C), granulated and calculated soil (D) were used. The superiority of these packing materials determined based on the values of non-biological removal per unit weight or unit volume of packing material, complete removal capacity of NH3 per unit weight of packing material per day or unit volume of packing material per day and pressure drop of the packed bed was in the order of A approximately = C > B > or = D. Packing materials A and C with high porosity, maximum water content, and suitable mean pore diameter showed excellent removal capacity.

  9. Errors and interferences in the determination of chromium in biological materials by INAA

    SciTech Connect

    Becker, D.A. )

    1993-01-01

    In the late 1950s, chromium was found to be important in animal nutrition, and shortly after that was found to be essential for human nutrition. The most important chromium function is in maintaining normal glucose tolerance primarily by regulating insulin action, although the exact molecular structure involved has not yet been determined. In addition, some interaction of chromium with thyroid metabolism and with nucleic acids in both experimental animals and humans has been postulated. However, dietary intake of chromium in the United States and in other developed countries is reported to be suboptimal by 30 to 50%, based on the minimum US daily intake of 50 [mu]g. There are analytical problems with the determination of chromium in biological materials by most analytical techniques, including neutron activation analysis (NAA). The well-known International Atomic Energy Agency (IAEA) intercomparison on milk powder produced results for chromium by 13 laboratories ranging over more than four orders of magnitude. More recently, the 1990 American Society for Testing and Materials task group intercomparison on apple leaves initially produced results having a range of 483% for the four laboratories reporting chromium. The peach leaves results were similar with a range of 450%. Note also that these latter two intercomparisons were on botanical matrices having relatively high chromium concentrations of [approximately] 0.3 and 1 mg/kg, compared to the IAEA milk with a concentration of 0.02 mg/kg. This paper reports on potential errors and interferences which can enter into chromium measurements by INAA. Some errors discussed are generic, applying to any measurement system, and some are specific to the problem of chromium in biological matrices.

  10. Biological monitoring involving children exposed to mercury from a barometer in a private residence.

    PubMed

    Scheepers, Paul T J; van Ballegooij-Gevers, Marieke; Jans, Henk

    2014-12-15

    A small spill of approximately 3 mL of mercury from a broken barometer in a residential setting resulted in blood values of 32 μg/L in a boy of 9 months and 26 μg/L in a girl of 2.5 years in samples collected within 6h after the start of the incident. A nanny who attempted to remove the spill had a blood mercury value of 20 μg/L at the same time point. These elevated blood values were attributed to inhalation rather than dermal uptake or ingestion. Exposure was aggravated by the use of a vacuum cleaner in an early attempt to remove the spill and incomplete decontamination of involved persons, leading to a continuation of exposure. Over a period of three months general cleaning was followed by targeted cleaning of hot spots until the indoor air mercury levels reached a median value of 0.090 μg/m(3) with a range of 0.032-0.140 μg/m(3). Meanwhile the family was staying in a shelter home. Human biological monitoring (HBM) was motivated by the complex exposure situation and the involvement of young children. Initially high blood values triggered alertness for clinical signs of intoxication, that (as it turned out) were not observed in any of the exposed individuals. Despite continued exposure from hair and clothes, within six weeks after the incident, blood levels returned to a background level normally seen in children. HBM contributed to reassurance of the parents of the young children that quick elimination of the mercury did not require medical treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Laser Desorption Postionization for Imaging MS of Biological Material

    PubMed Central

    Akhmetov, Artem; Moore, Jerry F.; Gasper, Gerald L.; Koin, Peter J.; Hanley, Luke

    2010-01-01

    Vacuum ultraviolet single photon ionization (VUV SPI) is a soft ionization technique that has the potential to address many of the limitations of MALDI for imaging MS. Laser desorption postionization (LDPI) employs VUV SPI for postionization and is experimentally analogous to a MALDI instrument with the addition of a pulsed VUV light source. This review discusses progress in LDPI-MS over the last decade, with an emphasis on imaging MS of bacterial biofilms, analytes whose high salt environment make them particularly resistant to imaging by MALDI-MS. This review first considers fundamental aspects of VUV SPI including ionization mechanisms, cross sections, quantum yields of ionization, dissociation, and potential mass limits. The most common sources of pulsed VUV radiation are then described along with a newly constructed LDPI-MS instrument with imaging capabilities. Next, the detection and imaging of small molecules within intact biofilms is demonstrated by LDPI-MS using 7.87 eV (157.6 nm) VUV photons from a molecular fluorine excimer laser, followed by the use of aromatic tags for detection of selected species within the biofilm. The final section considers the future prospects for imaging intact biological samples by LDPI-MS. PMID:20146224

  12. Laser desorption postionization for imaging MS of biological material.

    PubMed

    Akhmetov, Artem; Moore, Jerry F; Gasper, Gerald L; Koin, Peter J; Hanley, Luke

    2010-02-01

    Vacuum ultraviolet single photon ionization (VUV SPI) is a soft ionization technique that has the potential to address many of the limitations of matrix-assisted laser desorption/ionization (MALDI) for imaging MS. Laser desorption postionization (LDPI) uses VUV SPI for postionization and is experimentally analogous to a MALDI instrument with the addition of a pulsed VUV light source. This review discusses progress in LDPI-MS over the last decade, with an emphasis on imaging MS of bacterial biofilms, analytes whose high salt environment make them particularly resistant to imaging by MALDI-MS. This review first considers fundamental aspects of VUV SPI including ionization mechanisms, cross sections, quantum yields of ionization, dissociation and potential mass limits. The most common sources of pulsed VUV radiation are then described along with a newly constructed LDPI-MS instrument with imaging capabilities. Next, the detection and imaging of small molecules within intact biofilms is demonstrated by LDPI-MS using 7.87 eV (157.6 nm) VUV photons from a molecular fluorine excimer laser, followed by the use of aromatic tags for detection of selected species within the biofilm. The final section considers the future prospects for imaging intact biological samples by LDPI-MS. Copyright 2010 John Wiley & Sons, Ltd.

  13. Analysis of hazardous biological material by MALDI mass spectrometry

    SciTech Connect

    KL Wahl; KH Jarman; NB Valentine; MT Kingsley; CE Petersen; ST Cebula; AJ Saenz

    2000-03-21

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS) has become a valuable tool for analyzing microorganisms. The speed with which data can be obtained from MALDI-MS makes this a potentially important tool for biological health hazard monitoring and forensic applications. The excitement in the mass spectrometry community in this potential field of application is evident by the expanding list of research laboratories pursuing development of MALDI-MS for bacterial identification. Numerous research groups have demonstrated the ability to obtain unique MALDI-MS spectra from intact bacterial cells and bacterial cell extracts. The ability to differentiate strains of the same species has been investigated. Reproducibility of MALDI-MS spectra from bacterial species under carefully controlled experimental conditions has also been demonstrated. Wang et al. have reported on interlaboratory reproducibility of the MALDI-MS analysis of several bacterial species. However, there are still issues that need to be addressed, including the careful control of experimental parameters for reproducible spectra and selection of optimal experimental parameters such as solvent and matrix.

  14. Propulsion of swimming microrobots inspired by metachronal waves in ciliates: from biology to material specifications.

    PubMed

    Palagi, Stefano; Jager, Edwin W H; Mazzolai, Barbara; Beccai, Lucia

    2013-12-01

    The quest for swimming microrobots originates from possible applications in medicine, especially involving navigation in bodily fluids. Swimming microorganisms have become a source of inspiration because their propulsion mechanisms are effective in the low-Reynolds number regime. In this study, we address a propulsion mechanism inspired by metachronal waves, i.e. the spontaneous coordination of cilia leading to the fast swimming of ciliates. We analyse the biological mechanism (referring to its particular embodiment in Paramecium caudatum), and we investigate the contribution of its main features to the swimming performance, through a three-dimensional finite-elements model, in order to develop a simplified, yet effective artificial design. We propose a bioinspired propulsion mechanism for a swimming microrobot based on a continuous cylindrical electroactive surface exhibiting perpendicular wave deformations travelling longitudinally along its main axis. The simplified propulsion mechanism is conceived specifically for microrobots that embed a micro-actuation system capable of executing the bioinspired propulsion (self-propelled microrobots). Among the available electroactive polymers, we select polypyrrole as the possible actuation material and we assess it for this particular embodiment. The results are used to appoint target performance specifications for the development of improved or new electroactive materials to attain metachronal-waves-like propulsion.

  15. Biological potential of extraterrestrial materials - 1. Nutrients in carbonaceous meteorites, and effects on biological growth

    NASA Astrophysics Data System (ADS)

    Mautner, Michael N.

    1997-06-01

    Soil nutrient analysis of the Murchison C2 carbonaceous chondrite shows biologically available S, P, Ca, Mg, Na, K and Fe and cation exchange capacity (CEC) at levels comparable with terrestrial agricultural soils. Weathering, and aqueous, hydrothermal (121°C, 15 min) and high-temperature (550°C, 3 h) processing increase the extractable nutrients. Extractable phosphorus (by 0.3 M NH 4F + 0.1 M HCl) content, which may be growth-limiting, is 6.3 μg g -1 in the unprocessed meteorite, but increases to 81 μg g -1 by hydrothermal processing and weathering, and to 130 μg g -1 by high temperature processing. The cation exchange capacity (CEC), attributed mainly to the organic fraction, corresponds responds to 345 meq per 100 g of the polymer, suggesting one ionizable COOH or OH group per 3-4 aromatic rings. The Allende C3(V) meteorite has low extractable Ca, Mg and K, in parallel to its low organic content and CEC, but high extractable P levels (160 μg g -1). Biological effects are observed on growth of the soil microorganisms Flavobacterium oryzihabitans and Nocardia asteroides in meteorite extracts, and the population levels suggest that P is the limiting nutrient. Effects on plant growth are examined on Solanum tuberosum (potato), where extracts of the Murchison meteorite lead to enhanced growth and pigmentation. The biologically available organic and inorganic nutrients in carbonaceous chondrites can provide concentrated solutions for prebiotic and early life processes, and serve as soils and fertilizers for future space-based biological expansion.

  16. Microbial community analysis involved in the aerobic/extended-idle process performing biological phosphorus removal.

    PubMed

    Zeng, Tian-jing; Yang, Guo-jing; Wang, Dong-bo; Li, Xiao-ming; Zheng, Wei; Yang, Qi; Zeng, Guang-ming

    2013-01-01

    Recently, it has been found that biological phosphorus removal can be achieved in an aerobic/extended-idle (AEI) process using both glucose and acetate as the sole substrate. However, the microbial consortiums involved in glucose-fed and acetate-fed systems have not yet been characterized. Thus the aims of this paper were to investigate the diversities and dynamics of bacterial communities during the acclimation period, and to quantify polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in the systems. The phylogenetic analysis showed that the microbial communities were mainly composed of phylum Proteobacteria, Bacteroidetes, Chlorobi and another six kinds of unclassified bacteria. Fluorescence in-situ hybridization (FISH) analysis revealed that PAOs and GAOs accounted for 43 ± 7 and 16 ± 3% of all bacteria in the glucose-fed system, and 19 ± 4 and 35 ± 5% of total bacteria in the acetate-fed system, respectively. The results showed that the conventional PAOs could thrive in the AEI process, and a defined anaerobic zone was not necessarily required for putative PAOs growth.

  17. DNA Methylomes Reveal Biological Networks Involved in Human Eye Development, Functions and Associated Disorders.

    PubMed

    Berdasco, María; Gómez, Antonio; Rubio, Marcos J; Català-Mora, Jaume; Zanón-Moreno, Vicente; Lopez, Miguel; Hernández, Cristina; Yoshida, Shigeo; Nakama, Takahito; Ishikawa, Keijiro; Ishibashi, Tatsuro; Boubekeur, Amina M; Louhibi, Lotfi; Pujana, Miguel A; Sayols, Sergi; Setien, Fernando; Corella, Dolores; de Torres, Carmen; Parareda, Andreu; Mora, Jaume; Zhao, Ling; Zhang, Kang; Lleonart, Matilde E; Alonso, Javier; Simó, Rafael; Caminal, Josep M; Esteller, Manel

    2017-09-18

    This work provides a comprehensive CpG methylation landscape of the different layers of the human eye that unveils the gene networks associated with their biological functions and how these are disrupted in common visual disorders. Herein, we firstly determined the role of CpG methylation in the regulation of ocular tissue-specification and described hypermethylation of retinal transcription factors (i.e., PAX6, RAX, SIX6) in a tissue-dependent manner. Second, we have characterized the DNA methylome of visual disorders linked to internal and external environmental factors. Main conclusions allow certifying that crucial pathways related to Wnt-MAPK signaling pathways or neuroinflammation are epigenetically controlled in the fibrotic disorders involved in retinal detachment, but results also reinforced the contribution of neurovascularization (ETS1, HES5, PRDM16) in diabetic retinopathy. Finally, we had studied the methylome in the most frequent intraocular tumors in adults and children (uveal melanoma and retinoblastoma, respectively). We observed that hypermethylation of tumor suppressor genes is a frequent event in ocular tumors, but also unmethylation is associated with tumorogenesis. Interestingly, unmethylation of the proto-oncogen RAB31 was a predictor of metastasis risk in uveal melanoma. Loss of methylation of the oncogenic mir-17-92 cluster was detected in primary tissues but also in blood from patients.

  18. The retinoblastoma gene is involved in multiple aspects of stem cell biology.

    PubMed

    Galderisi, U; Cipollaro, M; Giordano, A

    2006-08-28

    Genetic programs controlling self-renewal and multipotentiality of stem cells have overlapping pathways with cell cycle regulation. Components of cell cycle machinery can play a key role in regulating stem cell self-renewal, proliferation, differentiation and aging. Among the negative regulators of cell cycle progression, the RB family members play a prominent role in controlling several aspects of stem cell biology. Stem cells contribute to tissue homeostasis and must have molecular mechanisms that prevent senescence and hold 'stemness'. RB can induce senescence-associated changes in gene expression and its activity is downregulated in stem cells to preserve self-renewal. Several reports evidenced that RB could play a role in lineage specification of several types of stem cells. RB has a role in myogenesis as well as in cardiogenesis. These effects are not only related to its role in suppressing E2F-responsive genes but also to its ability to modulate the activity of tissue-specific transcription factors. RB is also involved in adipogenesis through a strict control of lineage commitment and differentiation of adipocytes as well in determining the switch between brown and white adipocytes. Also, hematopoietic progenitor cells utilize the RB pathway to modulate cell commitment and differentiation. In this review, we will also discuss the role of the other two RB family members: Rb2/p130 and p107 showing that they have both specific and overlapping functions with RB gene.

  19. Antifungal characteristics of a fluorescent Pseudomonas strain involved in the biological control of Rhizoctonia solani.

    PubMed

    Pal, K K; Tilak, K V; Saxena, A K; Dey, R; Singh, C S

    2000-09-01

    A plant growth-promoting isolate of a fluorescent Pseudomonas spp. EM85 was found strongly antagonistic to Rhizoctonia solani, a causal agent of damping-off of cotton. The isolate produced HCN (HCN+), siderophore (Sid+), fluorescent pigments (Flu+) and antifungal antibiotics (Afa+). Tn5::lacZ mutagenesis of isolate EM85 resulted in the production of a series of mutants with altered production of HCN, siderophore, fluorescent pigments and antifungal antibiotics. Characterisation of these mutants revealed that the fluorescent pigment produced in PDA and the siderophore produced in CAS agar were not the same. Afa- and Flu- mutants had a smaller inhibition zone when grown with Rhizoctonia solani than the EM85 wild type. Sid- and HCN mutants failed to inhibit the pathogen in vitro. In a pot experiment, mutants deficient in HCN and siderophore production could suppress the damping-off disease by 52%. However, mutants deficient in fluorescent pigments and antifungal antibiotics failed to reduce the disease severity. Treatments with mutants that produced enhanced amounts of fluorescent pigments and antibiotics compared with EM85 wild type, exhibited an increase in biocontrol efficiency. Monitoring of the mutants in the rhizosphere using the lacZ marker showed identical proliferation of mutants and wild type. Purified antifungal compounds (fluorescent pigment and antibiotic) also inhibited the fungus appreciably in a TLC bioassay. Thus, the results indicate that fluorescent pigment and antifungal antibiotic of the fluorescent Pseudomonas spp. EM85 might be involved in the biological suppression of Rhizoctonia-induced damping-off of cotton.

  20. Biological functions of glycosyltransferase genes involved in O-fucose glycan synthesis.

    PubMed

    Okajima, Tetsuya; Matsuura, Aiko; Matsuda, Tsukasa

    2008-07-01

    Rare types of glycosylation often occur in a domain-specific manner and are involved in specific biological processes. Well-known examples of such modification are O-linked fucose (O-fucose) and O-linked glucose (O-glucose) glycans on epidermal growth factor (EGF) domains. In particular, O-fucose glycans are reported to regulate the functions of EGF domain-containing proteins such as urinary-type plasminogen activator and Notch receptors. Two glycosyltransferases catalyze the initiation and elongation of O-fucose glycans. The initiation process is catalyzed by O-fucosyltransferase 1, which is essential for Notch signalling in both Drosophila and mice. O-fucosyltransferase 1 can affect the folding, ligand interaction and endocytosis of Notch receptors, and both the glycosyltransferase and non-catalytic activities of O-fucosyltransferase 1 have been reported. The elongation of O-fucose monosaccharide is catalyzed by Fringe-related genes, which differentially modulate the interaction between Notch and two classes of ligands, namely, Delta and Serrate/Jagged. In this article, we have reviewed the recent reports addressing the distinctive features of the glycosyltransferases and O-glycans present on the EGF domains.

  1. Model of heterogeneous material dissolution in simulated biological fluid

    NASA Astrophysics Data System (ADS)

    Knyazeva, A. G.; Gutmanas, E. Y.

    2015-11-01

    In orthopedic research, increasing attention is being paid to bioresorbable/biodegradable implants as an alternative to permanent metallic bone healing devices. Biodegradable metal based implants possessing high strength and ductility potentially can be used in load bearing sites. Biodegradable Mg and Fe are ductile and Fe possess high strength, but Mg degrades too fast and Fe degrades too slow, Ag is a noble metal and should cause galvanic corrosion of the more active metallic iron - thus, corrosion of Fe can be increased. Nanostructuring should results in higher strength and can result in higher rate of dissolution/degradation from grain boundaries. In this work, a simple dissolution model of heterogeneous three phase nanocomposite material is considered - two phases being metal Fe and Ag and the third - nanopores. Analytical solution for the model is presented. Calculations demonstrate that the changes in the relative amount of each phase depend on mass exchange and diffusion coefficients. Theoretical results agree with preliminary experimental results.

  2. Interspecific variation in beeswax as a biological construction material.

    PubMed

    Buchwald, Robert; Breed, Michael D; Greenberg, Alan R; Otis, Gard

    2006-10-01

    Beeswax is a multicomponent material used by bees in the genus Apis to house larvae and store honey and pollen. We characterized the mechanical properties of waxes from four honeybee species: Apis mellifera L., Apis andreniformis L., Apis dorsata L. and two subspecies of Apis cerana L. In order to isolate the material effects from the architectural properties of nest comb, we formed raw wax in to right, circular cylindrical samples, and compressed them in an electromechanical tensometer. From the resulting stress-strain curves, values for yield stress, yield strain, stress and strain at the proportional limit, stiffness, and resilience were obtained. Apis dorsata wax was stiffer and had a higher yield stress and stress at the proportional limit than all of the other waxes. The waxes of A. cerana and A. mellifera had intermediate strength and stiffness, and A. andreniformis wax was the least strong, stiff and resilient. All of the waxes had similar strain values at the proportional limit and yield point. The observed differences in wax mechanical properties correlate with the nesting ecology of these species. A. mellifera and A. cerana nest in cavities that protect the nest from environmental stresses, whereas the species with the strongest and stiffest wax, A. dorsata, constructs relatively heavy nests attached to branches of tall trees, exposing them to substantially greater mechanical forces. The wax of A. andreniformis was the least strong, stiff and resilient, and their nests have low masses relative to other species in the genus and, although not built in cavities, are constructed on lower, often shielded branches that can absorb the forces of wind and rain.

  3. Detection of Biological Materials Using Ion Mobility Spectroscopy

    SciTech Connect

    Rodacy, P.J.; Sterling, J.P.; Butler, M.A.

    1999-03-01

    Traditionally, Ion Mobility Spectroscopy has been used to examine ions of relatively low molecular weight and high ion mobility. In recent years, however, biomolecules such as bradykinin, cytochrome c, bovine pancreatic trypsin inhibitor (BPTI), apomyoglobin, and lysozyme, have been successfully analyzed, but studies of whole bio-organisms have not been performed. In this study an attempt was made to detect and measure the mobility of two bacteriophages, {lambda}-phage and MS2 using electrospray methods to inject the viruses into the ion mobility spectrometer. Using data from Yeh, et al., which makes a comparison between the diameter of non-biologic particles and the specific particle mobility, the particle mobility for the MS2 virus was estimated to be 10{sup {minus}2} cm{sup 2}/volt-sec. From this mobility the drift time of these particles in our spectrometer was calculated to be approximately 65 msec. The particle mobility for the {lambda}-phage virus was estimated to be 10{sup {minus}3} cm{sup 2}/volt-sec. which would result in a drift time of 0.7 sec. Spectra showing the presence of a viral peak at the expected drift time were not observed. However, changes in the reactant ion peak that could be directly attributed to the presence of the viruses were observed. Virus clustering, excessive collisions, and the electrospray injection method limited the performance of this IMS. However, we believe that an instrument specifically designed to analyze such bioagents and utilizing other injection and ionization methods will succeed in directly detecting viruses and bacteria.

  4. A planar transmission-line sensor for measuring microwave permittivity of liquid and semisolid biological materials

    USDA-ARS?s Scientific Manuscript database

    An accurate technique for determining the permittivity of biological materials with coplanar waveguide transmission line is presented. The technique utilizes closed-form approximations that relate the material permittivity to the line propagation constant. A thru-reflect-line calibration procedure i...

  5. Spider dragline silk: correlated and mosaic evolution in high-performance biological materials.

    PubMed

    Swanson, Brook O; Blackledge, Todd A; Summers, Adam P; Hayashi, Cheryl Y

    2006-12-01

    The evolution of biological materials is a critical, yet poorly understood, component in the generation of biodiversity. For example, the diversification of spiders is correlated with evolutionary changes in the way they use silk, and the material properties of these fibers, such as strength, toughness, extensibility, and stiffness, have profound effects on ecological function. Here, we examine the evolution of the material properties of dragline silk across a phylogenetically diverse sample of species in the Araneomorphae (true spiders). The silks we studied are generally stronger than other biological materials and tougher than most biological or man-made fibers, but their material properties are highly variable; for example, strength and toughness vary more than fourfold among the 21 species we investigated. Furthermore, associations between different properties are complex. Some traits, such as strength and extensibility, seem to evolve independently and show no evidence of correlation or trade-off across species, even though trade-offs between these properties are observed within species. Material properties retain different levels of phylogenetic signal, suggesting that traits such as extensibility and toughness may be subject to different types or intensities of selection in several spider lineages. The picture that emerges is complex, with a mosaic pattern of trait evolution producing a diverse set of materials across spider species. These results show that the properties of biological materials are the target of selection, and that these changes can produce evolutionarily and ecologically important diversity.

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

    PubMed

    Lomakin, Joseph; Huber, Patricia A; Eichler, Christian; Arakane, Yasuyuki; Kramer, Karl J; Beeman, Richard W; Kanost, Michael R; Gehrke, Stevin H

    2011-02-14

    We determined the relationship between composition and mechanical properties of elytra (modified forewings that are composed primarily of highly sclerotized dorsal and less sclerotized ventral cuticles) from the beetles Tribolium castaneum (red flour beetle) and Tenebrio molitor (yellow mealworm). Elytra of both species have similar mechanical properties at comparable stages of maturation (tanning). Shortly after adult eclosion, the elytron of Tenebrio is ductile and soft with a Young's modulus (E) of 44 ± 8 MPa, but it becomes brittle and stiff with an E of 2400 ± 1100 MPa when fully tanned. With increasing tanning, dynamic elastic moduli (E') increase nearly 20-fold, whereas the frequency dependence of E' diminishes. These results support the hypothesis that cuticle tanning involves cross-linking of components, while drying to minimize plasticization has a lesser impact on cuticular stiffening and frequency dependence. Suppression of the tanning enzymes laccase-2 (TcLac2) or aspartate 1-decarboxylase (TcADC) in Tribolium altered mechanical characteristics consistent with hypotheses that (1) ADC suppression favors formation of melanic pigment with a decrease in protein cross-linking and (2) Lac2 suppression reduces both cuticular pigmentation and protein cross-linking.

  7. Nano-FTIR chemical mapping of minerals in biological materials

    PubMed Central

    Amarie, Sergiu; Zaslansky, Paul; Kajihara, Yusuke; Griesshaber, Erika; Schmahl, Wolfgang W

    2012-01-01

    Summary Methods for imaging of nanocomposites based on X-ray, electron, tunneling or force microscopy provide information about the shapes of nanoparticles; however, all of these methods fail on chemical recognition. Neither do they allow local identification of mineral type. We demonstrate that infrared near-field microscopy solves these requirements at 20 nm spatial resolution, highlighting, in its first application to natural nanostructures, the mineral particles in shell and bone. "Nano-FTIR" spectral images result from Fourier-transform infrared (FTIR) spectroscopy combined with scattering scanning near-field optical microscopy (s-SNOM). On polished sections of Mytilus edulis shells we observe a reproducible vibrational (phonon) resonance within all biocalcite microcrystals, and distinctly different spectra on bioaragonite. Surprisingly, we discover sparse, previously unknown, 20 nm thin nanoparticles with distinctly different spectra that are characteristic of crystalline phosphate. Multicomponent phosphate bands are observed on human tooth sections. These spectra vary characteristically near tubuli in dentin, proving a chemical or structural variation of the apatite nanocrystals. The infrared band strength correlates with the mineral density determined by electron microscopy. Since nano-FTIR sensitively responds to structural disorder it is well suited for the study of biomineral formation and aging. Generally, nano-FTIR is suitable for the analysis and identification of composite materials in any discipline, from testing during nanofabrication to even the clinical investigation of osteopathies. PMID:22563528

  8. Comparison of the biological H2S removal characteristics among four inorganic packing materials.

    PubMed

    Hirai, M; Kamamoto, M; Yani, M; Shoda, M

    2001-01-01

    Four inorganic packing materials were evaluated in terms of their availability as packing materials of a packed tower deodorization apparatus (biofilter) from the viewpoints of biological H2S removal characteristics and some physical properties. Among porous ceramics (A), calcinated cristobalite (B), calcinated and formed obsidian (C), granulated and calcinated soil (D), the superiority of these packing materials determined based on the values of non-biological removal per unit weight or unit volume of packing material, complete removal capacity of H2S per unit weight of packing material per day or unit volume of packing material per day and pressure drop of the packed bed was in the order of A approximately equal to C > D approximately equal to B, which is correlated with the maximum water content, porosity, and mean pore diameter.

  9. Small structures fabricated using ash-forming biological materials as templates.

    PubMed

    Kim, Youngbaek

    2003-01-01

    Different ash-forming biological materials such as gills of mushrooms, cotton wool, silk fiber, spider silk, dog's hair, and human hair were examined as templates to fabricate small structures. Ashes obtained from gills of mushrooms, silk fiber, and spider silk were miniaturized replicas of the original materials, whereas ashes from dog's hair and human hair were tubes. These materials were successfully coated with different inorganic materials by interface-selective sol-gel polymerization. Calcining coated materials yielded structures composed of ash and coated inorganic materials such as silica, titania, copper oxide, aluminum oxide, and iron oxide. Fully calcined ashes from native materials and materials coated with silica were usually 1/3 and 1/5 as large as their original materials, respectively. Silica-ash hybrid materials were much more rigid than ash materials. Incompletely calcined human hairs formed tubes with thick carbonized walls, and their inside morphologies suggested that medulla in human hairs might be responsible for tube formation. Preparation of complex tubular structures was possible as tied hairs did not break during calcination. Results in this study showed biological materials were useful as templates for fabricating inorganic structures regardless of ash formation.

  10. A numerical treatment of geodynamic viscous flow problems involving the advection of material interfaces

    NASA Technical Reports Server (NTRS)

    Lenardic, A.; Kaula, W. M.

    1993-01-01

    Effective numerical treatment of multicomponent viscous flow problems involving the advection of sharp interfaces between materials of differing physical properties requires correction techniques to prevent spurious diffusion and dispersion. We develop a particular algorithm, based on modern shock-capture techniques, employing a two-step nonlinear method. The first step involves the global application of a high-order upwind scheme to a hyperbolic advection equation used to model the distribution of distinct material components in a flow field. The second step is corrective and involves the application of a global filter designed to remove dispersion errors that result from the advection of discontinuities (e.g., material interfaces) by high-order, minimally dissipative schemes. The filter introduces no additional diffusion error. Nonuniform viscosity across a material interface is allowed for by the implementation of a compositionally weighted-inverse interface viscosity scheme. The combined method approaches the optimal accuracy of modern shock-capture techniques with a minimal increase in computational time and memory. A key advantage of this method is its simplicity to incorporate into preexisting codes be they finite difference, element, or volume of two or three dimensions.

  11. A numerical treatment of geodynamic viscous flow problems involving the advection of material interfaces

    NASA Technical Reports Server (NTRS)

    Lenardic, A.; Kaula, W. M.

    1993-01-01

    Effective numerical treatment of multicomponent viscous flow problems involving the advection of sharp interfaces between materials of differing physical properties requires correction techniques to prevent spurious diffusion and dispersion. We develop a particular algorithm, based on modern shock-capture techniques, employing a two-step nonlinear method. The first step involves the global application of a high-order upwind scheme to a hyperbolic advection equation used to model the distribution of distinct material components in a flow field. The second step is corrective and involves the application of a global filter designed to remove dispersion errors that result from the advection of discontinuities (e.g., material interfaces) by high-order, minimally dissipative schemes. The filter introduces no additional diffusion error. Nonuniform viscosity across a material interface is allowed for by the implementation of a compositionally weighted-inverse interface viscosity scheme. The combined method approaches the optimal accuracy of modern shock-capture techniques with a minimal increase in computational time and memory. A key advantage of this method is its simplicity to incorporate into preexisting codes be they finite difference, element, or volume of two or three dimensions.

  12. Finite element simulation for the mechanical characterization of soft biological materials by atomic force microscopy.

    PubMed

    Valero, C; Navarro, B; Navajas, D; García-Aznar, J M

    2016-09-01

    The characterization of the mechanical properties of soft materials has been traditionally performed through uniaxial tensile tests. Nevertheless, this method cannot be applied to certain extremely soft materials, such as biological tissues or cells that cannot be properly subjected to these tests. Alternative non-destructive tests have been designed in recent years to determine the mechanical properties of soft biological tissues. One of these techniques is based on the use of atomic force microscopy (AFM) to perform nanoindentation tests. In this work, we investigated the mechanical response of soft biological materials to nanoindentation with spherical indenters using finite element simulations. We studied the responses of three different material constitutive laws (elastic, isotropic hyperelastic and anisotropic hyperelastic) under the same process and analyzed the differences thereof. Whereas linear elastic and isotropic hyperelastic materials can be studied using an axisymmetric simplification, anisotropic hyperelastic materials require three-dimensional analyses. Moreover, we established the limiting sample size required to determine the mechanical properties of soft materials while avoiding boundary effects. Finally, we compared the results obtained by simulation with an estimate obtained from Hertz theory. Hertz theory does not distinguish between the different material constitutive laws, and thus, we proposed corrections to improve the quantitative measurement of specific material properties by nanoindentation experiments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Chemical analysis and biological testing of materials from the EDS coal liquefaction process: a status report

    SciTech Connect

    Later, D.W.; Pelroy, R.A.; Wilson, B.W.

    1984-05-01

    Representative process materials were obtained from the EDS pilot plant for chemical and biological analyses. These materials were characterized for biological activity and chemical composition using a microbial mutagenicity assay and chromatographic and mass spectrometric analytical techniques. The two highest boiling distillation cuts, as well as process solvent (PS) obtained from the bottoms recycle mode operation, were tested for initiation of mouse skin tumorigenicity. All three materials were active; the crude 800/sup 0 +/F cut was substantially more potent than the crude bottoms recycle PS or 750 to 800/sup 0/F distillate cut. Results from chemical analyses showed the EDS materials, in general, to be more highly alkylated and have higher hydroaromatic content than analogous SRC II process materials (no in-line process hydrogenation) used for comparison. In the microbial mutagenicity assays the N-PAC fractions showed greater activity than did the aliphatic hydrocarbon, hydroxy-PAH, or PAH fractions, although mutagenicity was detected in certain PAH fractions by a modified version of the standard microbial mutagenicity assay. Mutagenic activities for the EDS materials were lower, overall, than those for the corresponding materials from the SRC II process. The EDS materials produced under different operational modes had distinguishable differences in both their chemical constituency and biological activity. The primary differences between the EDS materials studied here and their SRC II counterparts used for comparison are most likely attributable to the incorporation of catalytic hydrogenation in the EDS process. 27 references, 28 figures, 27 tables.

  14. Digital learning material for student-directed model building in molecular biologyS.

    PubMed

    Aegerter-Wilmsen, Tinri; Coppens, Marjolijn; Janssen, Fred; Hartog, Rob; Bisseling, Ton

    2005-09-01

    The building of models to explain data and make predictions constitutes an important goal in molecular biology research. To give students the opportunity to practice such model building, two digital cases had previously been developed in which students are guided to build a model step by step. In this article, the development and initial evaluation of a third digital case is described. It concerns the selection of bristles during Drosophila development. To mimic a real research situation in a more realistic way, students are given much more freedom while building their models and can thus follow their own model-building approach. At the same time, however, students are provided with a sufficient amount of support to ensure that they can build their models without the requirement of intensive supervision.

  15. Resistance and stability of a new method for bonding biological materials using sutures and biological adhesives.

    PubMed

    Paéz, J M García; Sanmartín, A Carrera; Herrero, E Jorge; Millan, I; Cordon, A; Rocha, A; Maestro, M A; Téllez, G; Castillo-Olivares, J L

    2005-01-01

    The valve leaflets of cardiac bioprostheses are secured and shaped by sutures which, given their high degree of resistance and poor elasticity, have been implicated in the generation of stresses within the leaflets, contributing to the failure of the bioprostheses. Bioadhesives are bonding materials that have begun to be utilized in surgery, although there is a lack of experience in their use with inert tissues or bioprostheses. Tensile testing is performed until rupture in samples of calf pericardium, a biomaterial employed in the manufacture of bioprosthetic heart valve leaflets. One hundred and thirty-two trials are carried out in three types of samples: intact or control tissue (n = 12); samples transected and glued in an overlapping manner with a cyanoacrylate (n = 60); and samples transected, sewn with a commercially available suture material and reinforced at the suture holes with the same cyanoacrylate (n = 60). Seven days after their preparation, 12 samples from each group, including the controls, are subjected to tensile testing until rupture and the findings are compared. In the stability study, groups of 12 each of the remaining 48 glued and 48 sutured and glued samples underwent tensile testing until rupture on days 30, 60, 90, and 120, after their preparation. The results show that bonding with the adhesive provided a resistance ranging between 1.04 and 1.87 kg, probably insufficient for use in valve leaflets, but also afforded a high degree of elasticity. After 120 days, both the glued and the sutured and glued series show excellent elastic behavior, with no rigidity or hardening of the pericardium. These samples present reversible elongation, or strain, when they surpass their elastic limit at rupture. This finding may be due to a load concentration that is damaging to the pericardium, to the behavior of the tissue as an amorphous material, or perhaps to both circumstances. These results need to be confirmed in future studies as they may be of value

  16. "Standoff Biofinder" for Fast, Noncontact, Nondestructive, Large-Area Detection of Biological Materials for Planetary Exploration.

    PubMed

    Misra, Anupam K; Acosta-Maeda, Tayro E; Sharma, Shiv K; McKay, Christopher P; Gasda, Patrick J; Taylor, G Jeffrey; Lucey, Paul G; Flynn, Luke; Abedin, M Nurul; Clegg, Samuel M; Wiens, Roger

    2016-09-01

    We developed a prototype instrument called the Standoff Biofinder, which can quickly locate biological material in a 500 cm(2) area from a 2 m standoff distance with a detection time of 0.1 s. All biogenic materials give strong fluorescence signals when excited with UV and visible lasers. In addition, the luminescence decay time of biogenic compounds is much shorter (<100 ns) than the micro- to millisecond decay time of transition metal ions and rare-earth ions in minerals and rocks. The Standoff Biofinder takes advantage of the short lifetime of biofluorescent materials to obtain real-time fluorescence images that show the locations of biological materials among luminescent minerals in a geological context. The Standoff Biofinder instrument will be useful for locating biological material during future NASA rover, lander, and crewed missions. Additionally, the instrument can be used for nondestructive detection of biological materials in unique samples, such as those obtained by sample return missions from the outer planets and asteroids. The Standoff Biofinder also has the capacity to detect microbes and bacteria on space instruments for planetary protection purposes. Standoff Biofinder-Luminescence-Time-resolved fluorescence-Biofluorescence-Planetary exploration-Planetary protection-Noncontact nondestructive biodetection. Astrobiology 16, 715-729.

  17. ``Standoff Biofinder'' for Fast, Noncontact, Nondestructive, Large-Area Detection of Biological Materials for Planetary Exploration

    NASA Astrophysics Data System (ADS)

    Misra, Anupam K.; Acosta-Maeda, Tayro E.; Sharma, Shiv K.; McKay, Christopher P.; Gasda, Patrick J.; Taylor, G. Jeffrey; Lucey, Paul G.; Flynn, Luke; Nurul Abedin, M.; Clegg, Samuel M.; Wiens, Roger

    2016-09-01

    We developed a prototype instrument called the Standoff Biofinder, which can quickly locate biological material in a 500 cm2 area from a 2 m standoff distance with a detection time of 0.1 s. All biogenic materials give strong fluorescence signals when excited with UV and visible lasers. In addition, the luminescence decay time of biogenic compounds is much shorter (<100 ns) than the micro- to millisecond decay time of transition metal ions and rare-earth ions in minerals and rocks. The Standoff Biofinder takes advantage of the short lifetime of biofluorescent materials to obtain real-time fluorescence images that show the locations of biological materials among luminescent minerals in a geological context. The Standoff Biofinder instrument will be useful for locating biological material during future NASA rover, lander, and crewed missions. Additionally, the instrument can be used for nondestructive detection of biological materials in unique samples, such as those obtained by sample return missions from the outer planets and asteroids. The Standoff Biofinder also has the capacity to detect microbes and bacteria on space instruments for planetary protection purposes.

  18. Evaluation of geologic materials to limit biological intrusion into low-level radioactive waste disposal sites

    SciTech Connect

    Hakonson, T.E.

    1986-02-01

    This report describes the results of a three-year research program to evaluate the performance of selected soil and rock trench cap designs in limiting biological intrusion into simulated waste. The report is divided into three sections including a discussion of background material on biological interactions with waste site trench caps, a presentation of experimental data from field studies conducted at several scales, and a final section on the interpretation and limitations of the data including implications for the user.

  19. The Widespread Prevalence and Functional Significance of Silk-Like Structural Proteins in Metazoan Biological Materials

    PubMed Central

    McDougall, Carmel; Woodcroft, Ben J.

    2016-01-01

    In nature, numerous mechanisms have evolved by which organisms fabricate biological structures with an impressive array of physical characteristics. Some examples of metazoan biological materials include the highly elastic byssal threads by which bivalves attach themselves to rocks, biomineralized structures that form the skeletons of various animals, and spider silks that are renowned for their exceptional strength and elasticity. The remarkable properties of silks, which are perhaps the best studied biological materials, are the result of the highly repetitive, modular, and biased amino acid composition of the proteins that compose them. Interestingly, similar levels of modularity/repetitiveness and similar bias in amino acid compositions have been reported in proteins that are components of structural materials in other organisms, however the exact nature and extent of this similarity, and its functional and evolutionary relevance, is unknown. Here, we investigate this similarity and use sequence features common to silks and other known structural proteins to develop a bioinformatics-based method to identify similar proteins from large-scale transcriptome and whole-genome datasets. We show that a large number of proteins identified using this method have roles in biological material formation throughout the animal kingdom. Despite the similarity in sequence characteristics, most of the silk-like structural proteins (SLSPs) identified in this study appear to have evolved independently and are restricted to a particular animal lineage. Although the exact function of many of these SLSPs is unknown, the apparent independent evolution of proteins with similar sequence characteristics in divergent lineages suggests that these features are important for the assembly of biological materials. The identification of these characteristics enable the generation of testable hypotheses regarding the mechanisms by which these proteins assemble and direct the construction of

  20. Randomized trial of graft materials in transobturator tape operation: biological versus synthetic.

    PubMed

    Ugurlucan, Funda Gungor; Erkan, Habibe Ayyildiz; Onal, Murat; Yalcin, Onay

    2013-08-01

    To compare the outcome of outside-in biological and synthetic transobturator tape (TOT) operation, including subjective and objective success rates, urodynamics, and quality of life. One hundred patients suffering from clinical and/or urodynamic stress urinary incontinence (SUI) were randomized into biological material TOT (PELVILACE® TO) or synthetic material TOT (ALIGN®TO Urethral Support System) groups. Preoperative and at 1 year postoperative urogynecological symptom assessment, 1-h pad test, 4-day bladder diary, stress test, Q-tip test, and urodynamics were performed. For the evaluation of quality of life, the King's Health Questionnaire, Urogenital Distress Inventory-6, Incontinence Impact Questionnaire-7, and Prolapse Quality of Life were used. There was no significant difference between the two groups regarding objective and subjective cure rates and quality of life. At 1-year follow-up, the subjective cure rate was 68 % in the biological material TOT and 70 % in the synthetic material TOT group. No perioperative complications developed. Groin pain developed in 2 patients in the biological TOT group and 1 patient had dehiscence in the periurethral incision, which healed with local estrogen. Two patients had transient urinary retention in the synthetic TOT group, 1 patient developed groin pain, and 1 patient had mesh erosion observed at the 1-year follow-up. Transobturator tape with biological material in the management of SUI has a rate of success and patient satisfaction similar to those of synthetic material at 1-year follow-up. Studies with longer follow-up and larger cohorts are necessary to evaluate possible autolysis and degradation of biological slings and a possible reduction in efficacy over time.

  1. Critical Motor Involvement in Prediction of Human and Non-biological Motion Trajectories

    PubMed Central

    de Wit, Matthieu M.; Buxbaum, Laurel J.

    2017-01-01

    Objectives Adaptive interaction with the environment requires the ability to predict both human and non-biological motion trajectories. Prior accounts of the neurocognitive basis for prediction of these two motion classes may generally be divided into those that posit that non-biological motion trajectories are predicted using the same motor planning and/or simulation mechanisms used for human actions, and those that posit distinct mechanisms for each. Using brain lesion patients and healthy controls, this study examined critical neural substrates and behavioral correlates of human and non-biological motion prediction. Methods Twenty-seven left hemisphere stroke patients and 13 neurologically intact controls performed a visual occlusion task requiring prediction of pantomimed tool use, real tool use, and non-biological motion videos. Patients were also assessed with measures of motor strength and speed, praxis, and action recognition. Results Prediction impairment for both human and non-biological motion was associated with limb apraxia and, weakly, with the severity of motor production deficits, but not with action recognition ability. Furthermore, impairment for human and non-biological motion prediction was equivalently associated with lesions in the left inferior parietal cortex, left dorsal frontal cortex, and the left insula. Conclusions These data suggest that motor planning mechanisms associated with specific loci in the sensorimotor network are critical for prediction of spatiotemporal trajectory information characteristic of both human and non-biological motions. PMID:28205497

  2. A chirality-based search for extraterrestrial biological and prebiological material

    NASA Astrophysics Data System (ADS)

    Kolokolova, Lioudmila; Sparks, William; Nagdimunov, Lev

    2013-04-01

    Important evidence relevant to extraterrestrial life is the existence in space of organic molecules of prebiological or biological significance. Such molecules are often characterized by a special type of asymmetry called "homochirality" (domination of molecules of a specific handedness). This results in optical activity of the material that contains those molecules. Due to optical activity, the light scattered by such materials is characterized by non-zero circular polarization. We review laboratory measurements of light scattered by biological (e.g. bacteria, leaves) and non-biological (minerals) samples. These have revealed distinctive features in the circular polarization spectra in absorption bands for the biological samples. We present theoretical simulations of light scattering by homochiral materials made with the superposition T-matrix code for clusters of optically-active spheres. This allowed us to simulate light scattering by biological objects, e.g. colonies of bacteria, and by materials of prebiological value, e.g. cometary dust. We explore how circular polarization depends on the porosity and size of aggregates. Based on this, we provide some recommendations for observing signs of life in space, specifically, on exoplanets. This study was supported by the NASA Exobiology and Astrobiology Program.

  3. Clinical and histological correlations in alveolar bone osteosynthesis using biological materials of cow origin.

    PubMed

    Suciu, M; Kelemen, C; Cotoi, O S; Toma, Felicia

    2011-01-01

    Periodontitis is a set of inflammatory diseases affecting the periodontium, i.e., the tissues that surround and support the teeth. Periodontitis involves progressive loss of the alveolar bone around the teeth, and if left untreated, can lead to the loosening and subsequent loss of teeth and is one of the most common diseases worldwide. Modern techniques of treatment consist of guided bone regeneration, in cases of massive bone loss. We present a case of a middle age male with no risk factors, suffering from infected chronic marginal periodontitis with III/IV degree of mobility at the lower right canine and III degree of mobility at the lower incisors. X-ray exam reveals massive bone resorption in the anterior part of the mandible, especially in the right canine area. Because the buccal and lingual cortical bone were missing in the canine area, it was impossible for the bone to heal after the extraction of 4.3., without bone augmentation. The histopathological exam revealed the aspect of an organic protein matrix, partially calcified and the presence of some isolated cells with osteocytes like morphology. The difficulties of this procedure are to position and to close the flap without tension in order to facilitate the healing and bone cells formation - osteoblasts and osteocytes. The bone augmentation using biological material proved to be successful in treating massive bone defects in order to insert dental implants.

  4. Impact of schoolchildren's involvement in the design process on the effectiveness of healthy food promotion materials.

    PubMed

    Gustafson, Christopher R; Abbey, Bryce M; Heelan, Kate A

    2017-06-01

    Marketing techniques may improve children's vegetable consumption. However, student participation in the design of marketing materials may increase the material's salience, while also improving children's commitment and attitudes towards healthy eating. The impact of student-led design of vegetable promotional materials on choice and consumption was investigated using 1614 observations of students' vegetable choice and plate waste in four public elementary schools in Kearney, Nebraska. Data were collected on children's vegetable choice and consumption in four comparison groups: 1) control; 2) students designed materials only; 3) students were exposed to promotional materials only; and 4) students designed materials that were then posted in the lunchroom. Vegetable choice and consumption data were collected through a validated digital photography-based plate-waste method. Multivariate linear regression was used to estimate average treatment effects of the conditions at various time periods. Dependent variables were vegetable choice and consumption, and independent variables included the condition, time period, and interaction terms, as well as controls for gender and grade. Relative to baseline, students in group 4 doubled their vegetable consumption (p < 0.001) when materials were posted. Vegetable consumption remained elevated at a follow-up 2-3 months later (p < 0.05). Students in group 3 initially increased the quantity of vegetables selected (p < 0.05), but did not increase consumption. In the follow-up period, however, students in group 3 increased their vegetable consumption (p < 0.01). Involving elementary-aged students in the design of vegetable promotional materials that were posted in the lunchroom increased the amount of vegetables students consumed.

  5. Membrane materials for storing biological samples intended for comparative nanotoxicological testing

    NASA Astrophysics Data System (ADS)

    Metelkin, A.; Kuznetsov, D.; Kolesnikov, E.; Chuprunov, K.; Kondakov, S.; Osipov, A.; Samsonova, J.

    2015-11-01

    The study is aimed at identifying the samples of most promising membrane materials for storing dry specimens of biological fluids (Dried Blood Spots, DBS technology). Existing sampling systems using cellulose fiber filter paper have a number of drawbacks such as uneven distribution of the sample spot, dependence of the spot spreading area on the individual biosample properties, incomplete washing-off of the sample due to partially inconvertible sorption of blood components on cellulose fibers, etc. Samples of membrane materials based on cellulose, polymers and glass fiber with applied biosamples were studied using methods of scanning electron microscopy, FT-IR spectroscopy and surface-wetting measurement. It was discovered that cellulose-based membrane materials sorb components of biological fluids inside their structure, while membranes based on glass fiber display almost no interaction with the samples and biological fluid components dry to films in the membrane pores between the structural fibers. This characteristic, together with the fact that membrane materials based on glass fiber possess sufficient strength, high wetting properties and good storage capacity, attests them as promising material for dry samples of biological fluids storage systems.

  6. [Determination of nicotine and cotinine in human biological materials and their significance in toxicological studies].

    PubMed

    Wiergowski, Marek; Nowak-Banasik, Livia; Morkowska, Anna; Galer-Tatarowicz, Katarzyna; Szpiech, Beata; Korolkiewicz, Roman; Anand, Jacek Sein

    2006-01-01

    The aim of this study was the preparation of reliable procedure of the determination of nicotine and cotinine both in classic (serum, urine) and alternative biological materials (hair, saliva) and evaluation of their significance for clinical and forensic toxicology. Biological material samples (blood, urine, saliva) were taken from patients after Percutaneous Trans-luminal Coronary Angioplasty (PTCA). The determination of cotinine and nicotine concentration in the biological material should be optimized depending on the aim of analysis. Liquid-liquid extraction procedure and high performance liquid chromatography HPLC/UV-DAD are reliable, specific and relatively cheap. Serum and saliva are valuable biological materials which allow to determine temporary nicotine and cotinine content on the similar level of concentrations. In the near future it will be able to replace blood with saliva sample because of an easy and non-invasive way of sampling. Evaluation of cotinine concentration in urine allows to distinguish the passive from the active tobacco smokers. Hair analysis allows to control a nicotine abstinence as well as a long-term evaluation of the history of smoking. However usage of hair is limited because of difficulty with sampling. Interpretation of results in analysis of alternative materials (hair, saliva) pose a problem because of lack of sampling standardization and lack of standardization of final analysis method.

  7. Turning residual human biological materials into research collections: playing with consent.

    PubMed

    Gefenas, Eugenijus; Dranseika, Vilius; Serepkaite, Jurate; Cekanauskaite, Asta; Caenazzo, Luciana; Gordijn, Bert; Pegoraro, Renzo; Yuko, Elizabeth

    2012-06-01

    This article focuses on three scenarios in which residual biological materials are turned into research collections during the procedure of procuring these materials for diagnostic, therapeutic or other non-research purposes. These three scenarios differ from each other primarily because they employ different models of consent: (a) precautionary consent, which may be secured during the collecting procedure; (b) the presumed consent model, which may be applied during the collection of materials; and (c) consent for research use of identifiable human biological materials, which may be skipped entirely. These scenarios offer additional sources of biological samples for research purposes and at the same time seem to offer even more flexibility in terms of stringency of consent as compared with the more traditional models of broad consent in prospective research collections and the waiver of consent in retrospective research. Our discussion leads us to think that precautionary consent is preferable to presumed consent and no consent when handling issues of consent in the use of residual human biological materials for research. However, such precautionary consent should not be construed as blanket, unrestricted consent for any future use.

  8. New biological reference materials - in vivo incorporated toxic metals in water hyacinth tissues

    SciTech Connect

    Austin, J.R.; Simon, S.J.; Williams, L.R.; Beckert, W.F.

    1985-06-01

    The purpose of this study was to demonstrate that high-quality reference materials, containing high levels of multiple toxic elements, can be produced with in vivo incorporation procedures. The approach taken was to produce water hyacinth tissue materials - leaves and stems containing high levels of arsenic, cadmium, lead, and mercury - as follows: apply a hydroponic feeding procedure for the in vivo incorporation of toxic elements into water hyacinths; dry, blend, and homogenize the plant materials and determine the levels of the incorporated elements and the homogeneity of the generated plant material; demonstrate that low-level control materials can be successfully blended with high-level materials to yield a homogeneous material with intermediate toxicant levels; evaluate the precision of the analytical methods used to determine toxic element levels in the materials; and evaluate the stability of the resulting materials. Sufficient quantities of the parent materials were produced so that characterized reference materials can now be made available on request. Levels of the toxic elements incorporated in water hyacinth leaves were 100, 300, 60, and 27 times the levels present in the control leaves for arsenic, cadmium, lead, and mercury, respectively. Overall precision of sampling, subsampling, and digestion, and chemical analysis of the treated materials, ranged from 3 to 10% relative standard deviation and was generally comparable to that of three NBS biological reference materials tested. 3 references, 1 figure, 4 tables.

  9. 45 CFR 46.206 - Research involving, after delivery, the placenta, the dead fetus or fetal material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Research involving, after delivery, the placenta..., Human Fetuses and Neonates Involved in Research § 46.206 Research involving, after delivery, the placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the dead...

  10. 45 CFR 46.206 - Research involving, after delivery, the placenta, the dead fetus or fetal material.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Research involving, after delivery, the placenta..., Human Fetuses and Neonates Involved in Research § 46.206 Research involving, after delivery, the placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the dead...

  11. 45 CFR 46.206 - Research involving, after delivery, the placenta, the dead fetus or fetal material.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Research involving, after delivery, the placenta..., Human Fetuses and Neonates Involved in Research § 46.206 Research involving, after delivery, the placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the dead...

  12. 45 CFR 46.206 - Research involving, after delivery, the placenta, the dead fetus or fetal material.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Research involving, after delivery, the placenta..., Human Fetuses and Neonates Involved in Research § 46.206 Research involving, after delivery, the placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the dead...

  13. 45 CFR 46.206 - Research involving, after delivery, the placenta, the dead fetus or fetal material.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Research involving, after delivery, the placenta..., Human Fetuses and Neonates Involved in Research § 46.206 Research involving, after delivery, the placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the dead...

  14. Analysis of biological reference materials, prepared by microwave dissolution, using inductively coupled plasma mass spectrometry.

    PubMed

    Friel, J K; Skinner, C S; Jackson, S E; Longerich, H P

    1990-03-01

    A procedure has been developed for the analysis of biological materials by inductively coupled plasma mass spectrometry (ICP-MS). Fast, efficient and complete sample digestion is achieved by a combined microwave-nitric acid/open beaker-nitric acid-hydrogen peroxide procedure. The ICP-MS analysis is performed with an on-line five-element internal standard to correct for matrix and instrumental drift effects. Results are presented for 24 elements in three biological reference materials (National Institute of Standards and Technology Standard Reference Materials 5277a Liver and 1566 Oyster and International Atomic Energy Agency Certified Reference Material H4 Animal Muscle). For all elements significantly above the detection limit and reagent blank concentrations, good agreement exists between ICP-MS and certified values.

  15. New biologically active composite materials on the basis of dialdehyde cellulose

    NASA Astrophysics Data System (ADS)

    Khashirov, Azamat A.; Zhansitov, Azamat A.; Zaikov, Genadiy E.; Khashirova, Svetlana Yu.

    2014-05-01

    In this work for the first time have been studied modification peculiarities of microcrystalline cellulose (MCC) and its oxidized form (dialdehyde cellulose DA!) guanidine-containing monomers and polymers of vinyl and diallyl series. Researched the structure of the composites by IR spectroscopy and SEM. The biological activity of the synthesized composite materials was investigated and shown that the composite synthesized materials are quite active and have a biocidal effect against Gram-positive (St.Aureus) and Gram (E.coli) microorganisms.

  16. Hazards assessment of worst case transportation accidents involving typical radioactive material shipments.

    PubMed

    Dodd, B; Humphries, L L

    1988-12-01

    This paper reports the results of a study performed for the Oregon Department of Energy. The objectives of the study were to characterize the range of radioactive material shipments through the state and to determine the worst radiological hazards which might arise if these shipments were involved in transportation accidents. The direct and indirect radiological hazards were analyzed for worst case accidents involving a total of 10 typical shipments. The direct hazard primarily involved the gamma radiation from the material, while the indirect hazard considered the airborne release hazards of inhalation/ingestion, cloudshine and groundshine. The general and specific assumptions used in the study are given, and the results are tabulated, giving doses and dose rates as a function of distance. The data from the study are being incorporated into a protective action guide for use by state and local emergency responders. This guide bases the protective actions on the available, observable data and on flow charts which use the worst-case assumptions for unknown data.

  17. Invited review liquid crystal models of biological materials and silk spinning.

    PubMed

    Rey, Alejandro D; Herrera-Valencia, Edtson E

    2012-06-01

    A review of thermodynamic, materials science, and rheological liquid crystal models is presented and applied to a wide range of biological liquid crystals, including helicoidal plywoods, biopolymer solutions, and in vivo liquid crystals. The distinguishing characteristics of liquid crystals (self-assembly, packing, defects, functionalities, processability) are discussed in relation to biological materials and the strong correspondence between different synthetic and biological materials is established. Biological polymer processing based on liquid crystalline precursors includes viscoelastic flow to form and shape fibers. Viscoelastic models for nematic and chiral nematics are reviewed and discussed in terms of key parameters that facilitate understanding and quantitative information from optical textures and rheometers. It is shown that viscoelastic modeling the silk spinning process using liquid crystal theories sheds light on textural transitions in the duct of spiders and silk worms as well as on tactoidal drops and interfacial structures. The range and consistency of the predictions demonstrates that the use of mesoscopic liquid crystal models is another tool to develop the science and biomimetic applications of mesogenic biological soft matter. Copyright © 2011 Wiley Periodicals, Inc.

  18. A Rodent Model to Evaluate the Tissue Response to a Biological Scaffold When Adjacent to a Synthetic Material.

    PubMed

    Dearth, Christopher L; Keane, Timothy J; Scott, Jeffrey R; Daly, Kerry A; Badylak, Stephen F

    2015-10-01

    The use of biologic scaffold materials adjacent to synthetic meshes is commonplace. A prevalent clinical example is two-staged breast reconstruction, where biologic scaffolds are used to provide support and coverage for the inferior aspect of the synthetic expander. However, limited data exist regarding either the kinetics of biologic scaffold integration or the host tissue response to the biologic scaffold materials used for this application or other applications in which such scaffold materials are used. The present study evaluated the temporal host response to a biological scaffold when placed adjacent to a synthetic material. Evaluation criteria included quantification of material contracture and characterization of the host cell response and tissue remodeling events. Results show a decreased thickness of the collagenous tissue layer at biologic scaffold/silicone interface compared to the abdominal wall/silicone interface during the 12-week experimental time course. All test materials were readily incorporated into surrounding host tissue.

  19. Measuring the complex permittivity tensor of uniaxial biological materials with coplanar waveguide transmission line

    USDA-ARS?s Scientific Manuscript database

    A simple and accurate technique is described for measuring the uniaxial permittivity tensor of biological materials with a coplanar waveguide transmission-line configuration. Permittivity tensor results are presented for several chicken and beef fresh meat samples at 2.45 GHz....

  20. Optimization of spatial frequency domain imaging technique for estimating optical properties of food and biological materials

    USDA-ARS?s Scientific Manuscript database

    Spatial frequency domain imaging technique has recently been developed for determination of the optical properties of food and biological materials. However, accurate estimation of the optical property parameters by the technique is challenging due to measurement errors associated with signal acquis...

  1. Raman imaging from microscopy to macroscopy: Quality and safety control of biological materials

    USDA-ARS?s Scientific Manuscript database

    Raman imaging can analyze biological materials by generating detailed chemical images. Over the last decade, tremendous advancements in Raman imaging and data analysis techniques have overcome problems such as long data acquisition and analysis times and poor sensitivity. This review article introdu...

  2. Evaluation of precision and accuracy of selenium measurements in biological materials using neutron activation analysis

    SciTech Connect

    Greenberg, R.R.

    1988-01-01

    In recent years, the accurate determination of selenium in biological materials has become increasingly important in view of the essential nature of this element for human nutrition and its possible role as a protective agent against cancer. Unfortunately, the accurate determination of selenium in biological materials is often difficult for most analytical techniques for a variety of reasons, including interferences, complicated selenium chemistry due to the presence of this element in multiple oxidation states and in a variety of different organic species, stability and resistance to destruction of some of these organo-selenium species during acid dissolution, volatility of some selenium compounds, and potential for contamination. Neutron activation analysis (NAA) can be one of the best analytical techniques for selenium determinations in biological materials for a number of reasons. Currently, precision at the 1% level (1s) and overall accuracy at the 1 to 2% level (95% confidence interval) can be attained at the U.S. National Bureau of Standards (NBS) for selenium determinations in biological materials when counting statistics are not limiting (using the {sup 75}Se isotope). An example of this level of precision and accuracy is summarized. Achieving this level of accuracy, however, requires strict attention to all sources of systematic error. Precise and accurate results can also be obtained after radiochemical separations.

  3. Biological and biochemical properties of the carbon composite and polyethylene implant materials.

    PubMed

    Pesáková, V; Smetana, K; Balík, K; Hruska, J; Petrtýl, M; Hulejová, H; Adam, M

    2003-06-01

    We studied the biocompatibility of the carbon composites and polyethylene materials with and without collagen or collagen and proteoglycan cover. We used the in vitro technology to study the adhesion of model cells evalution, their metabolic activity and the production of TNF-alpha as a cytokine model. Under in vivo condition, the biocompatibility of tested polymers were studied in the implantation experiment, subcutaneously in the interscapular region in the laboratory rat. We have found in the in vitro assay favorable proliferation and the smallest production of pro-inflammatory TNF-alpha cytokine in cells adherent to the hydrophobic polyethylene material coated with biological macromolecules. Using in vivo tests performed by the implantation of materials to the rat we demonstrated that the materials are not cytotoxic. The tissue capsule surrounding the implants was not significantly influenced by the type of the implant and the pre-treatment by the biological molecules. However, the foreign-body giant multinucleated cells were observed only in the vicinity of the collagen - covered hydrophobic polyethylene implant. Interestingly, while the collagen coating improved the biocompatibility of tested polymers in vitro, the inflammatory reaction against this covered materials was higher under in vivo conditions. The pre-treatment of carbon composites by both types of biological macromolecules reduced the occurrence of carbon debris in the implantation site. The tested carbon composites and polyethylene materials are not toxic. The pre-treatment of the materials by extracellular matrix components increased their biological tolerance in vitro and reduced implant wears in animal experiment, which can be important for the medical application.

  4. Differential Multiscale Modeling of Chemically Complex Materials under Heavy Deformation: Biological, Bioinspired and Synthetic Hierarchical Materials

    DTIC Science & Technology

    2010-06-01

    to provide protective surfaces (e.g. in seashells, bone, spider silk ). We demonstrated the development and application of such material design...M.J. Buehler, “Molecular and nanostructural mechanisms of deformation, strength and toughness of spider silk fibrils”, Nano Letters, accepted for...level. Courtesy J. Andzelm (ARL) Mechanical response of spider silk 1-2 GPa 34 Z. Shao and F. Vollrath, Nature, 2002 Spider silk with diameter of O(inch

  5. Biological rationale for the intramedullary canal as a source of autograft material.

    PubMed

    Hak, David J; Pittman, Jason L

    2010-01-01

    Bone harvested by intramedullary reaming offers a minimally invasive alternative to harvesting bone from the iliac crest, which has long been considered the gold standard for autogenous bone grafting. The biologic potential of intramedullary reaming material has been studied both in vitro and in vivo. The material provides osteogenic, osteoinductive, and osteoconductive properties that are comparable to the material harvested from the iliac crest. In addition to the ability to obtain a large volume of bone, the graft harvested by the Reamer-Irrigator-Aspirator has been shown to be rich in growth factors, including BMP-2, TGF-beta1, IGF-I, FGFa, and PDGFbb.

  6. Large-scale study of the interactions between proteins involved in type IV pilus biology in Neisseria meningitidis: characterization of a subcomplex involved in pilus assembly.

    PubMed

    Georgiadou, Michaella; Castagnini, Marta; Karimova, Gouzel; Ladant, Daniel; Pelicic, Vladimir

    2012-06-01

    The functionally versatile type IV pili (Tfp) are one of the most widespread virulence factors in bacteria. However, despite generating much research interest for decades, the molecular mechanisms underpinning the various aspects of Tfp biology remain poorly understood, mainly because of the complexity of the system. In the human pathogen Neisseria meningitidis for example, 23 proteins are dedicated to Tfp biology, 15 of which are essential for pilus biogenesis. One of the important gaps in our knowledge concerns the topology of this multiprotein machinery. Here we have used a bacterial two-hybrid system to identify and quantify the interactions between 11 Pil proteins from N. meningitidis. We identified 20 different binary interactions, many of which are novel. This represents the most complex interaction network between Pil proteins reported to date and indicates, among other things, that PilE, PilM, PilN and PilO, which are involved in pilus assembly, indeed interact. We focused our efforts on this subset of proteins and used a battery of assays to determine the membrane topology of PilN and PilO, map the interaction domains between PilE, PilM, PilN and PilO, and show that a widely conserved N-terminal motif in PilN is essential for both PilM-PilN interactions and pilus assembly. Finally, we show that PilP (another protein involved in pilus assembly) forms a complex with PilM, PilN and PilO. Taken together, these findings have numerous implications for understanding Tfp biology and provide a useful blueprint for future studies.

  7. Formative Assessment and Increased Student Involvement Increase Grades in an Upper Secondary School Biology Course

    ERIC Educational Resources Information Center

    Granbom, Martin

    2016-01-01

    This study shows that formative methods and increased student participation has a positive influence on learning measured as grades. The study was conducted during the course Biology A in a Swedish Upper Secondary School. The students constructed grade criteria and defined working methods and type of examination within a given topic, Gene…

  8. Formative Assessment and Increased Student Involvement Increase Grades in an Upper Secondary School Biology Course

    ERIC Educational Resources Information Center

    Granbom, Martin

    2016-01-01

    This study shows that formative methods and increased student participation has a positive influence on learning measured as grades. The study was conducted during the course Biology A in a Swedish Upper Secondary School. The students constructed grade criteria and defined working methods and type of examination within a given topic, Gene…

  9. Sound and Faulty Arguments Generated by Preservice Biology Teachers When Testing Hypotheses Involving Unobservable Entities.

    ERIC Educational Resources Information Center

    Lawson, Anton E.

    2002-01-01

    Investigates the responses of a sample of preservice biology teachers enrolled in a teaching methods course to a casual question about why water rose in a jar inverted over a burning candle placed in a pan of water by formulating and testing six hypotheses. (Contains 43 references.) (Author/YDS)

  10. Accommodating ontologies to biological reality--top-level categories of cumulative-constitutively organized material entities.

    PubMed

    Vogt, Lars; Grobe, Peter; Quast, Björn; Bartolomaeus, Thomas

    2012-01-01

    The Basic Formal Ontology (BFO) is a top-level formal foundational ontology for the biomedical domain. It has been developed with the purpose to serve as an ontologically consistent template for top-level categories of application oriented and domain reference ontologies within the Open Biological and Biomedical Ontologies Foundry (OBO). BFO is important for enabling OBO ontologies to facilitate in reliably communicating and managing data and metadata within and across biomedical databases. Following its intended single inheritance policy, BFO's three top-level categories of material entity (i.e. 'object', 'fiat object part', 'object aggregate') must be exhaustive and mutually disjoint. We have shown elsewhere that for accommodating all types of constitutively organized material entities, BFO must be extended by additional categories of material entity. Unfortunately, most biomedical material entities are cumulative-constitutively organized. We show that even the extended BFO does not exhaustively cover cumulative-constitutively organized material entities. We provide examples from biology and everyday life that demonstrate the necessity for 'portion of matter' as another material building block. This implies the necessity for further extending BFO by 'portion of matter' as well as three additional categories that possess portions of matter as aggregate components. These extensions are necessary if the basic assumption that all parts that share the same granularity level exhaustively sum to the whole should also apply to cumulative-constitutively organized material entities. By suggesting a notion of granular representation we provide a way to maintain the single inheritance principle when dealing with cumulative-constitutively organized material entities. We suggest to extend BFO to incorporate additional categories of material entity and to rearrange its top-level material entity taxonomy. With these additions and the notion of granular representation, BFO would

  11. Antimicrobial and biological activity of leachate from light curable pulp capping materials.

    PubMed

    Arias-Moliz, Maria Teresa; Farrugia, Cher; Lung, Christie Y K; Wismayer, Pierre Schembri; Camilleri, Josette

    2017-09-01

    Characterization of a number of pulp capping materials and assessment of the leachate for elemental composition, antimicrobial activity and cell proliferation and expression. Three experimental light curable pulp-capping materials, Theracal and Biodentine were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The elemental composition of the leachate formed after 24h was assessed by inductively coupled plasma (ICP). The antimicrobial activity of the leachate was determined by the minimum inhibitory concentration (MIC) against multispecies suspensions of Streptococcus mutans ATCC 25175, Streptococcus gordonii ATCC 33478 and Streptococcus sobrinus ATCC 33399. Cell proliferation and cell metabolic function over the material leachate was assessed by an indirect contact test using 3-(4,5 dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The hydration behavior of the test materials varied with Biodentine being the most reactive and releasing the highest amount of calcium ions in solution. All materials tested except the unfilled resin exhibited depletion of phosphate ions from the solution indicating interaction of the materials with the media. Regardless the different material characteristics, there was a similar antimicrobial activity and cellular activity. All the materials exhibited no antimicrobial activity and were initially cytotoxic with cell metabolic function improving after 3days. The development of light curable tricalcium silicate-based pulp capping materials is important to improve the bonding to the final resin restoration. Testing of both antimicrobial activity and biological behavior is critical for material development. The experimental light curable materials exhibited promising biological properties but require further development to enhance the antimicrobial characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. HRI catalytic two-stage liquefaction (CTSL) process materials: chemical analysis and biological testing

    SciTech Connect

    Wright, C.W.; Later, D.W.

    1985-12-01

    This report presents data from the chemical analysis and biological testing of coal liquefaction materials obtained from the Hydrocarbon Research, Incorporated (HRI) catalytic two-stage liquefaction (CTSL) process. Materials from both an experimental run and a 25-day demonstration run were analyzed. Chemical methods of analysis included adsorption column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, low-voltage probe-inlet mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The biological activity was evaluated using the standard microbial mutagenicity assay and an initiation/promotion assay for mouse-skin tumorigenicity. Where applicable, the results obtained from the analyses of the CTSL materials have been compared to those obtained from the integrated and nonintegrated two-stage coal liquefaction processes. 18 refs., 26 figs., 22 tabs.

  13. Linking sediment chemical and biological guidelines for characterization of dredged material.

    PubMed

    Casado-Martínez, M C; Riba, I; Blasco, J; DelValls, T A

    2005-01-01

    Dredged material management in Spain and possible options for the different categories is discussed according to chemical sediment quality guidelines. Also an approach using an integrated assessment that includes biological end points as part of a tiered testing schema is discussed for future implementation in Spanish recommendations. To establish the feasibility of using both kinds of guidelines, an example of the utility and validity of the approach that links both chemical and biological guidelines proposed for the management of dredged material characterization processes data from a particular case study associated with a port in the north of Spain are discussed. The use of both kinds of methodologies, together with the necessity of assessing the bioavailability of some contaminants, has been shown as a powerful tool for the best selection of different disposal options of dredged material in the case study described.

  14. The importance of cultural considerations in the promotion of ethical research with human biologic material.

    PubMed

    Jenkins, Gwynne L; Sugarman, Jeremy

    2005-03-01

    Although ethical consideration has been given to a wide variety of issues that arise in the collection and storage of human biologic material for research, little attention has been focused on the ethical implications of the diverse cultural meanings often associated with these materials. We explore the rich social meanings of the placenta across cultures and contrast these meanings with the assumption that the placenta is typically considered waste tissue that may find value in biomedical research. We suggest that the incorporation of sensitivity to the cultural meanings people give human biologic material and the use of empirical research, where necessary, to delineate these meanings should enhance the ability to craft and conduct ethically appropriate research.

  15. Evaluation of natural materials as exogenous carbon sources for biological treatment of low carbon-to-nitrogen wastewater.

    PubMed

    Ramírez-Godínez, Juan; Beltrán-Hernández, Icela; Álvarez-Hernández, Alejandro; Coronel-Olivares, Claudia; Contreras-López, Elizabeth; Quezada-Cruz, Maribel; Vázquez-Rodríguez, Gabriela

    2015-01-01

    In the bacterial processes involved in the mitigation of nitrogen pollution, an adequately high carbon-to-nitrogen (C : N) ratio is key to sustain denitrification. We evaluated three natural materials (woodchips, barley grains, and peanut shells) as carbon sources for low C : N wastewater. The amount of organic matter released from these materials to aqueous media was evaluated, as well as their pollution swapping potential by measuring the release of total Kjeldahl nitrogen, N-NH4 (+), NO2 (-), and NO3 (-), and total phosphorous. Barley grains yielded the highest amount of organic matter, which also showed to be the most easily biodegradable. Woodchips and peanut shells released carbon rather steadily and so they would not require frequent replenishment from biological reactors. These materials produced eluates with lower concentrations of nutrients than the leachates from barley grains. However, as woodchips yielded lower amounts of suspended solids, they constitute an adequate exogenous source for the biological treatment of carbon-deficient effluents.

  16. Evaluation of Natural Materials as Exogenous Carbon Sources for Biological Treatment of Low Carbon-to-Nitrogen Wastewater

    PubMed Central

    Ramírez-Godínez, Juan; Beltrán-Hernández, Icela; Álvarez-Hernández, Alejandro; Coronel-Olivares, Claudia; Contreras-López, Elizabeth; Quezada-Cruz, Maribel; Vázquez-Rodríguez, Gabriela

    2015-01-01

    In the bacterial processes involved in the mitigation of nitrogen pollution, an adequately high carbon-to-nitrogen (C : N) ratio is key to sustain denitrification. We evaluated three natural materials (woodchips, barley grains, and peanut shells) as carbon sources for low C : N wastewater. The amount of organic matter released from these materials to aqueous media was evaluated, as well as their pollution swapping potential by measuring the release of total Kjeldahl nitrogen, N-NH4+, NO2−, and NO3−, and total phosphorous. Barley grains yielded the highest amount of organic matter, which also showed to be the most easily biodegradable. Woodchips and peanut shells released carbon rather steadily and so they would not require frequent replenishment from biological reactors. These materials produced eluates with lower concentrations of nutrients than the leachates from barley grains. However, as woodchips yielded lower amounts of suspended solids, they constitute an adequate exogenous source for the biological treatment of carbon-deficient effluents. PMID:26495313

  17. Measurement of complex permittivities of biological materials and human skin in vivo in the frequency band

    SciTech Connect

    Ghodgaonkar, D.K.

    1987-01-01

    A new method, namely, modified infinite sample method, has been developed which is particularly suitable for millimeter-wave dielectric measurements of biological materials. In this method, an impedance transformer is used which reduces the reflectivity of the biological sample. Because of the effect of introducing impendance transformer, the measured reflection coefficients are more sensitive to the complex permittivities of biological samples. For accurate measurement of reflection coefficients, two automated measurment systems were developed which cover the frequencies range of 26.5-60 GHz. An uncertainty analysis was performed to get an estimate of the errors in the measured complex permittivities. The dielectric properties were measured for 10% saline solution, whole human blood, 200 mg/ml bovine serum albumin (BSA) solution and suspension of Saccharomyces cerevisiae cells. The Maxwell-Fricke equation, which is derived from dielectric mixture theory, was used for determination bound water in BSA solution. The results of all biological samples were interpreted by fitting Debye relaxation and Cole-Cole model. It is observed that the dielectric data for the biological materials can be explained on the basis of Debye relaxation of water molecule.

  18. Evaluation of a fungal collection as certified reference material producer and as a biological resource center.

    PubMed

    Forti, Tatiana; Souto, Aline da S S; do Nascimento, Carlos Roberto S; Nishikawa, Marilia M; Hubner, Marise T W; Sabagh, Fernanda P; Temporal, Rosane Maria; Rodrigues, Janaína M; da Silva, Manuela

    2016-01-01

    Considering the absence of standards for culture collections and more specifically for biological resource centers in the world, in addition to the absence of certified biological material in Brazil, this study aimed to evaluate a Fungal Collection from Fiocruz, as a producer of certified reference material and as Biological Resource Center (BRC). For this evaluation, a checklist based on the requirements of ABNT ISO GUIA34:2012 correlated with the ABNT NBR ISO/IEC17025:2005, was designed and applied. Complementing the implementation of the checklist, an internal audit was performed. An evaluation of this Collection as a BRC was also conducted following the requirements of the NIT-DICLA-061, the Brazilian internal standard from Inmetro, based on ABNT NBR ISO/IEC 17025:2005, ABNT ISO GUIA 34:2012 and OECD Best Practice Guidelines for BRCs. This was the first time that the NIT DICLA-061 was applied in a culture collection during an internal audit. The assessments enabled the proposal for the adequacy of this Collection to assure the implementation of the management system for their future accreditation by Inmetro as a certified reference material producer as well as its future accreditation as a Biological Resource Center according to the NIT-DICLA-061.

  19. [Constitution of a bank of biological material in the French Gazel cohort: logistical and practical aspects].

    PubMed

    Zins, M; Ozguler, A; Bonenfant, S; Henny, J; Goldberg, M

    2003-02-01

    The Gazel cohort was launched in January 1989 among workers of the French national electricity and gas company to form an open and general purpose epidemiological laboratory. More than 20.000 workers (15.000 men, 5.000 women), aged from 35 to 50 volunteered to participate. One of the objectives of this cohort was the constitution of a bank of biological material aiming to collect and preserve various biological samples (serum, plasma, DNA, etc). This paper details the organisation of the bank and presents a feasability study concerning 2.000 volunteers.

  20. Searching for biological traces on different materials using a forensic light source and infrared photography.

    PubMed

    Sterzik, V; Panzer, S; Apfelbacher, M; Bohnert, M

    2016-05-01

    Because biological traces often play an important role in the investigation process of criminal acts, their detection is essential. As they are not always visible to the human eye, tools like a forensic light source or infrared photography can be used. The intention of the study presented was to give advice how to visualize biological traces best. Which wavelengths and/or filters give the best results for different traces on different fabrics of different colors? Therefore, blood (undiluted and diluted), semen, urine, saliva, and perspiration have been examined on 29 different materials.

  1. Theory of coherent charge transport in junctions involving unconventional superconducting materials

    NASA Astrophysics Data System (ADS)

    Burmistrova, A. V.; Devyatov, I. A.

    2016-10-01

    Recent theoretical studies of coherent charge transport in junctions involving unconventional superconducting materials such as high-temperature superconducting iron-based pnictides (FeBS) and in structures with induced superconductivity which are formed of a thin metal layer with spin-orbit coupling in contact with an s-wave superconductor (SSO) are reported. The theoretical analysis is performed with our unified approach based on the tight-binding method and boundary conditions obtained for it. This approach makes it possible to take into account a complex nonparabolic and anisotropic spectrum of normal excitations in unconventional superconducting materials and their multiband character, as well as unusual types of symmetries of the superconducting order parameter in them. The possibility of a semiclassical description in the case of intraorbital superconducting pairing is demonstrated. The method of calculations and their results are presented for the conductivities of junctions between a normal metal and unconventional superconducting materials, as well as for the Josephson current. Comparison with the experiment for the junction with FeBS is performed and indicates the presence of the unusual s± symmetry of the order parameter. An experiment is proposed to test our theoretical results for SSO.

  2. Emergency communication and information issues in terrorist events involving radioactive materials.

    PubMed

    Becker, Steven M

    2004-01-01

    With the threat posed by terrorism involving radioactive materials now high on the nation's agenda, local, state, and federal agencies are moving to enhance preparedness and response capabilities. Crucial to these efforts is the development of effective risk communication strategies. This article reports findings from an ongoing study of risk communication issues in nuclear/radiological terrorism situations. It is part of a larger CDC-funded effort that aims to better understand communication challenges associated with weapons of mass destruction terrorism incidents. Presented here are formative research findings from 16 focus groups (n = 163) in which a multi-part, hypothetical radioactive materials terrorism situation was discussed. Twelve of the focus groups were carried out with members of the general public (drawn from a variety of ethnic backgrounds and geographic locations), and four groups were composed of first responders, hospital emergency department personnel, and public health professionals. One aim of the focus groups was to elicit detailed information on people's knowledge, views, perceptions, reactions, and concerns related to a nuclear/radiological terrorism event, and to better understand people's specific information needs and preferred information sources. A second aim was to pretest draft informational materials prepared by CDC and NIOSH. Key findings for the public and professional groups are presented, and the implications of the research for developing messages in radiological/nuclear terrorism situations are explored.

  3. A discrete spectral analysis for determining quasi-linear viscoelastic properties of biological materials

    PubMed Central

    Babaei, Behzad; Abramowitch, Steven D.; Elson, Elliot L.; Thomopoulos, Stavros; Genin, Guy M.

    2015-01-01

    The viscoelastic behaviour of a biological material is central to its functioning and is an indicator of its health. The Fung quasi-linear viscoelastic (QLV) model, a standard tool for characterizing biological materials, provides excellent fits to most stress–relaxation data by imposing a simple form upon a material's temporal relaxation spectrum. However, model identification is challenging because the Fung QLV model's ‘box’-shaped relaxation spectrum, predominant in biomechanics applications, can provide an excellent fit even when it is not a reasonable representation of a material's relaxation spectrum. Here, we present a robust and simple discrete approach for identifying a material's temporal relaxation spectrum from stress–relaxation data in an unbiased way. Our ‘discrete QLV’ (DQLV) approach identifies ranges of time constants over which the Fung QLV model's typical box spectrum provides an accurate representation of a particular material's temporal relaxation spectrum, and is effective at providing a fit to this model. The DQLV spectrum also reveals when other forms or discrete time constants are more suitable than a box spectrum. After validating the approach against idealized and noisy data, we applied the methods to analyse medial collateral ligament stress–relaxation data and identify the strengths and weaknesses of an optimal Fung QLV fit. PMID:26609064

  4. A discrete spectral analysis for determining quasi-linear viscoelastic properties of biological materials.

    PubMed

    Babaei, Behzad; Abramowitch, Steven D; Elson, Elliot L; Thomopoulos, Stavros; Genin, Guy M

    2015-12-06

    The viscoelastic behaviour of a biological material is central to its functioning and is an indicator of its health. The Fung quasi-linear viscoelastic (QLV) model, a standard tool for characterizing biological materials, provides excellent fits to most stress-relaxation data by imposing a simple form upon a material's temporal relaxation spectrum. However, model identification is challenging because the Fung QLV model's 'box'-shaped relaxation spectrum, predominant in biomechanics applications, can provide an excellent fit even when it is not a reasonable representation of a material's relaxation spectrum. Here, we present a robust and simple discrete approach for identifying a material's temporal relaxation spectrum from stress-relaxation data in an unbiased way. Our 'discrete QLV' (DQLV) approach identifies ranges of time constants over which the Fung QLV model's typical box spectrum provides an accurate representation of a particular material's temporal relaxation spectrum, and is effective at providing a fit to this model. The DQLV spectrum also reveals when other forms or discrete time constants are more suitable than a box spectrum. After validating the approach against idealized and noisy data, we applied the methods to analyse medial collateral ligament stress-relaxation data and identify the strengths and weaknesses of an optimal Fung QLV fit. © 2015 The Author(s).

  5. Versatile and inexpensive Hall-Effect force sensor for mechanical characterization of soft biological materials.

    PubMed

    Backman, Daniel E; LeSavage, Bauer L; Wong, Joyce Y

    2017-01-25

    Mismatch of hierarchical structure and mechanical properties between tissue-engineered implants and native tissue may result in signal cues that negatively impact repair and remodeling. With bottom-up tissue engineering approaches, designing tissue components with proper microscale mechanical properties is crucial to achieve necessary macroscale properties in the final implant. However, characterizing microscale mechanical properties is challenging, and current methods do not provide the versatility and sensitivity required to measure these fragile, soft biological materials. Here, we developed a novel, highly sensitive Hall-Effect based force sensor that is capable of measuring mechanical properties of biological materials over wide force ranges (μN to N), allowing its use at all steps in layer-by-layer fabrication of engineered tissues. The force sensor design can be easily customized to measure specific force ranges, while remaining easy to fabricate using inexpensive, commercial materials. Although we used the force sensor to characterize mechanics of single-layer cell sheets and silk fibers, the design can be easily adapted for different applications spanning larger force ranges (>N). This platform is thus a novel, versatile, and practical tool for mechanically characterizing biological and biomimetic materials.

  6. [THE ROLE OF MATERNAL DIET IN METABOLIC AND BEHAVIOURAL PROGRAMMING: REVIEW OF BIOLOGIC MECHANISMS INVOLVED].

    PubMed

    Ramírez-López, María Teresa; Vázquez Berrios, Mariam; Arco González, Rocío; Blanco Velilla, Rosario Noemí; Decara Del Olmo, Juan; Suárez Pérez, Juan; Rodríguez de Fonseca, Fernando; Gómez de Heras, Raquel

    2015-12-01

    Over the last few years, a considerable amount of studies have focused on the effect of undernutrition and overnutrition during critical periods of offspring development and their risk of developing metabolic diseases later in life. Additionally, inadequate maternal diets have been involved in the malprogramming of brain functions and some behaviours. Several mechanisms have been associated with the process of malprogramming such as epigenetics modifications, excessive oxidative stress or hypothalamic alterations. This evidence supports the idea that nutritional prevention strategies must be considered for offspring during early development stages that include the preconceptional period. Additionally, studying involved mechanisms could be particularly useful in the search of efficient therapies against malprogramming.

  7. Proposed framework for cleanup and site restoration following a terrorist incident involving radioactive material.

    PubMed

    Conklin, W Craig

    2005-11-01

    Cleanup following a terrorism incident involving a radiological dispersal device (RDD) or improvised nuclear device (IND) is likely to be technically challenging, costly, and politically charged. Lessons learned from the Top Officials 2 exercise and the increased threat of terrorist use of an RDD or IND have driven federal officials to push for an agreed-upon process for determining appropriate cleanup levels. State and local authorities generally have the ultimate responsibility for final public health decisions in their jurisdictions. In response to terrorist attacks, local authorities are likely to request federal assistance in assessing the risk and establishing appropriate cleanup levels. It is realistic to expect local and state requests for significant federal assistance in planning and implementing recovery operations. State and local authorities may desire "shared accountability" with the federal government in setting the appropriate cleanup levels. Government officials at all levels will face pressure to say how clean is clean enough and how quickly people can re-enter affected areas. Issues arising include (1) the nature of the relationship between the federal, state, and local leadership involved in the recovery efforts and (2) where the funding for recovery comes from. Many agencies, including the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) have long been involved in cleanup activities involving radioactive materials. These agencies have recognized the need for a participatory process and realize the need to remain flexible when faced with possible unprecedented environmental challenges following a terrorist attack. Currently, the Department of Homeland Security has a committee process underway, with participation of the EPA, NRC, DOE, and other federal agencies, to try to resolve these issues and to begin engaging state, local, and tribal governments, and others as

  8. Sound and faulty arguments generated by preservice biology teachers when testing hypotheses involving unobservable entities

    NASA Astrophysics Data System (ADS)

    Lawson, Anton E.

    2002-03-01

    A sample of preservice biology teachers (biology majors) enrolled in a teaching methods course formulated and attempted to test six hypotheses to answer a causal question about why water rose in a jar inverted over a burning candle placed in a pan of water. The students submitted a lab report in which arguments and evidence for testing each hypothesis were presented in an if/then/therefore hypothetico-predictive form. Analysis of written arguments revealed considerable success when students were able to manipulate observable hypothesized causes. However, when the hypothesized causes were unobservable, such that they could be only indirectly tested, performance dropped, as shown by use of three types of faulty arguments: (a) arguments that had missing or confused elements, (b) arguments whose predictions did not follow from hypotheses and planned tests, and (c) arguments that failed to consider alternative hypotheses. Science is an enterprise in which unobservable theoretical entities and processes (e.g., atoms, genes, osmosis, and photosynthesis) are often used to explain observable phenomena. Consequently, if it is assumed that effective teaching requires prior understanding, then it follows that these future teachers have yet to develop adequate hypothesis-testing skills and sufficient awareness of the nature of science to teach science in the inquiry mode advocated by reform guidelines.

  9. Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification.

    PubMed

    Janssen, Albert J H; Lens, Piet N L; Stams, Alfons J M; Plugge, Caroline M; Sorokin, Dimitri Y; Muyzer, Gerard; Dijkman, Henk; Van Zessen, Erik; Luimes, Peter; Buisman, Cees J N

    2009-02-01

    In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual CODorganic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH4 (80-90 vol.%), CO2 (10-20 vol.%) and H2S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H2S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass.

  10. A COMPARATIVE STUDY OF THE CLASSROOM PRACTICES AND TEACHING RATIONALE OF HIGH SCHOOL BIOLOGY TEACHERS USING DIFFERENT CURRICULUM MATERIALS.

    ERIC Educational Resources Information Center

    KOCHENDORFER, LEONARD HJALMAR

    EXAMINED WERE THE CLASSROOM PRACTICES AND TEACHING RATIONALE OF HIGH SCHOOL BIOLOGY TEACHERS USING VARIOUS CURRICULUM MATERIALS. THREE GROUPS (64 TEACHERS) WERE ORGANIZED. GROUP EB CONSISTED OF 22 TEACHERS WITH A MEAN OF FIVE YEARS EXPERIENCE IN USING BIOLOGICAL SCIENCES CURRICULUM STUDY (BSCS) MATERIALS. GROUP BB CONSISTED OF 21 EXPERIENCED…

  11. [Determination of bromochlorodifluoromethane (Halon 1211) in biological material by gas chromatography with mass detector].

    PubMed

    Pufal, Ewa; Sykutera, Marzena; Sliwka, Karol

    2004-01-01

    A gas chromatographic method with mass spectrometry has been developed for the determination of bromochlorodifluoromethane (Halon 1211) in biological material (whole blood, organ samples). After incubation of the sample (temp. 65 degrees C, 15 min), 10 microliters of the headspace is analysed using a capillary column DB-5 ms (30 m x 0.25 mm x 0.25 micron). Quantitative analysis was made with the use of a single ion monitoring option--m/z 85 and m/z 87. This developed method was used to determine the concentration of bromochlorodifluoromethane in biological material collected from the body of the man whose death was due to intoxication of Halon 1211--fire-extinguisher contents.

  12. Trace elemental content of biological materials. A comparison of NAA and ICP-MS analysis.

    PubMed

    Ward, N I; Abou-Shakra, F R; Durrant, S F

    1990-01-01

    The advantages and disadvantages of neutron activation analysis (NAA) and inductively coupled plasma-source mass spectrometry (ICP-MS) for the analysis of biological materials is reviewed. Comparison is made between NAA (instrumental) and ICP-MS (conventional pneumatic solution nebulization and laser ablation) analysis of the biological reference material National Bureau of Standards (NBS) SRM 1577 Bovine Liver. Relatively good agreement is achieved between the results for the 18 elements analyzed by both techniques and those either certified or reported in the literature. Elemental concentrations for Li, Mg, Al, Ca, Cr, Mn, Fe, Cu, Zn, Br, Rb, and Cs are also reported for IAEA Mixed Human Diet (H9), NBS SRM 909 Human Serum, and NBS SRM 1577a Bovine Liver, analyzed by solution nebulization ICP-MS.

  13. Imaging laser heated subsurface chromophores in biological materials: determination of lateral physical dimensions.

    PubMed

    Milner, T E; Goodman, D M; Tanenbaum, B S; Anvari, B; Svaasand, L O; Nelson, J S

    1996-01-01

    We describe a non-contact method using infrared radiometry to determine lateral physical dimensions of laser heated subsurface chromophores in biological materials. An imaging equation is derived that relates measured radiometric temperature change to the reduced two-dimensional temperature increase of laser heated chromophores. From measured images of radiometric temperature change, the lateral physical dimensions of chromophores positioned in an in vitro model of human skin are determined by deconvolution of the derived imaging equation using a non-negative constrained conjugate gradient algorithm. Conditions for optimum spatial resolution are found by analysis of a derived radiometric transfer function and correspond to superficial chromophores and/or weak infrared absorption in a laser irradiated biological material. Analysis indicates that if the infrared attenuation coefficient is sufficiently small (i.e., less than 10mm-1), infrared radiometry in combination with a deconvolution algorithm allows estimation of lateral physical dimensions of laser heated subsurface chromophores in human skin.

  14. Research on biological materials of human origin. Jurists and scientists face to face. Commentary.

    PubMed

    Petrini, Carlo; Ricciardi, Walter

    2017-01-01

    On 3rd October 2016 a convention was held in the Aldo Moro room of the Chamber of Deputies on "Research on biological materials of human origin. Jurists and scientists face to face". The convention was organised by the Bioethics Unit of the Istituto Superiore di Sanità (ISS, Italian National Institute of Health) in conjunction with the Italian Academy of the Internet Code (IAIC) and the Fondazione Centro di Iniziativa Giuridica Piero Calamandrei. The present contribution reports the topics discussed and the key conclusions reached. As a follow-up to the discussion, the scientists, jurists and institutions concerned are resolved to take further steps towards the formulation of operational proposals intended to facilitate research using human biological materials within a framework of precise and strict regulations.

  15. Determination of trace metals in marine biological reference materials by inductively coupled plasma mass spectrometry

    SciTech Connect

    Beauchemin, D.; McLaren, J.W.; Willie, S.N.; Berman, S.S.

    1988-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) was used for the analysis of two marine biological reference materials (dogfish liver tissue (DOLT-1) and dogfish muscle tissue (DORM-1)). The materials were put into solution by digestion in a nitric acid/hydrogen peroxide mixture. Thirteen elements (Na, Mg, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Cd, Hg, and Pb) were then determined. Accurate results were obtained by standard additions or isotope dilution techniques for all of these elements in DORM-1 and for all but Cr in DOLT-1.

  16. The spectral applications of Beer-Lambert law for some biological and dosimetric materials

    NASA Astrophysics Data System (ADS)

    Içelli, Orhan; Yalçin, Zeynel; Karakaya, Vatan; Ilgaz, Işıl P.

    2014-08-01

    The aim of this study is to conduct quantitative and qualitative analysis of biological and dosimetric materials which contain organic and inorganic materials and to make the determination by using the spectral theorem Beer-Lambert law. Beer-Lambert law is a system of linear equations for the spectral theory. It is possible to solve linear equations with a non-zero coefficient matrix determinant forming linear equations. Characteristic matrix of the linear equation with zero determinant is called point spectrum at the spectral theory.

  17. Active matter at the interface between materials science and cell biology

    NASA Astrophysics Data System (ADS)

    Needleman, Daniel; Dogic, Zvonimir

    2017-09-01

    The remarkable processes that characterize living organisms, such as motility, self-healing and reproduction, are fuelled by a continuous injection of energy at the microscale. The field of active matter focuses on understanding how the collective behaviours of internally driven components can give rise to these biological phenomena, while also striving to produce synthetic materials composed of active energy-consuming components. The synergistic approach of studying active matter in both living cells and reconstituted systems assembled from biochemical building blocks has the potential to transform our understanding of both cell biology and materials science. This methodology can provide insight into the fundamental principles that govern the dynamical behaviours of self-organizing subcellular structures, and can lead to the design of artificial materials and machines that operate away from equilibrium and can thus attain life-like properties. In this Review, we focus on active materials made of cytoskeletal components, highlighting the role of active stresses and how they drive self-organization of both cellular structures and macroscale materials, which are machines powered by nanomachines.

  18. Analytical model for optical bistability in nonlinear metal nano-antennae involving Kerr materials.

    PubMed

    Zhou, Fei; Liu, Ye; Li, Zhi-Yuan; Xia, Younan

    2010-06-21

    Optical bistability at nanoscale is a promising way to realize optical switching, a key component of integrated nanophotonic devices. In this work we present an analytical model for optical bistability in a metal nano-antenna involving Kerr nonlinear medium based on detailed analysis of the correlation between the incident and extinction light intensity under surface plasmon resonance (SPR). The model allows one to construct a clear picture on how the threshold, contrast, and other characteristics of optical bistability are influenced by the nonlinear coefficient, incident light intensity, local field enhancement factor, SPR peak width, and other physical parameters of the nano-antenna. It shows that the key towards low threshold power and high contrast optical bistability in the nanosystem is to reduce the SPR peak width. This can be achieved by reducing the absorption of metal materials or introducing gain media into nanosystems.

  19. Lead determination in slurries of biological materials by ETAAS using a W-Rh permanent modifier.

    PubMed

    Lima, E C; Barbosa, F; Krug, F J

    2001-03-01

    A tungsten-rhodium coating on the integrated platform of a transversely heated graphite atomiser (THGA) was used as a permanent chemical modifier for the determination of lead in biological materials by slurry sampling in electrothermal atomic absorption spectrometry (ETAAS). Slurries were sonicated during 20 s before being delivered to the previously W-Rh treated platform. The number of particles of biological materials introduced into the atomiser for delivering 20 microL slurry aliquot ranged from 5,100 to 39,000. The permanent W-Rh modifier remained stable during approximately 300 analytical measurements when 20 microL of slurries containing up to 1.5% m/v were delivered into the atomiser. In addition, the permanent modifier increases the tube lifetime by approximately 100% when compared to untreated integrated platforms. Also, there is less decrease of sensitivity during the atomiser lifetime when compared with the conventional modifiers, resulting in a decreased need of re-calibration during routine analysis and consequently increasing the sample throughput. The atomiser lifetime was limited to the THGA wall durability, because the W-Rh treated platform was intact after more than 650 analytical firings in a medium containing up to 1.5% m/v slurry of biological material. The detection limit based on integrated absorbance was 20 ng g(-1) Pb for 1.50% m/v slurries. Results from the determination of lead in slurries of biological materials using the W-Rh permanent modifier were in agreement with those obtained with digested solutions using Pd + Mg(NO3)2.

  20. Dredging Operations Technical Support Program: Guidance for Contracting Biological and Chemical Evaluations of Dredged Material

    DTIC Science & Technology

    1990-09-01

    toxi - cology researchers that sediment toxicity tests are more difficult to reproduce than the classic bioassay, in which fish are exposed to a well...shrimp, copepods, Daphnia , or algae. Although most organ- isms used in dredged material testing may be purchased or collected, these may be cultured in the...Biological screens that are available may be useful in comparing and ranking sediments within a proj- ect area. Daphnia , mysid, and amphipod sediment

  1. [Biological effects of arsenic and diseases: The mechanisms involved in arsenic-induced carcinogenesis].

    PubMed

    Suzuki, Takehiro; Takumi, Shota; Okamura, Kazuyuki; Nohara, Keiko

    2016-07-01

    Chronic arsenic exposure is associated with many diseases, including cancers. Our study using in vivo assay in gpt-delta transgenic mice showed that arsenic particularly induces G : C to T : A transversions, a mutation type induced through oxidative-stress-induced 8-OHdG formation. Gestational arsenic exposure of C3H mice was reported to increase hepatic tumor incidence. We showed that gestational arsenic exposure increased hepatic tumors having activated oncogene Ha-ras by C to A mutation. We also showed that DNA methylation status of Fosb region is implicated in tumor augmentation by gestational arsenic exposure. We further showed that long-term arsenic exposure induces premature senescence. Recent studies reported that senescence is involved in not only tumor suppression, but also tumorgenesis. All these effects of arsenic might be involved in arsenic-induced carcinogenesis.

  2. Interactions and effects of metal oxide nanoparticles on microorganisms involved in biological wastewater treatment.

    PubMed

    Cervantes-Avilés, Pabel; Díaz Barriga-Castro, Enrique; Palma-Tirado, Lourdes; Cuevas-Rodríguez, Germán

    2017-10-01

    To clarify the toxicological effects of metal oxide nanoparticles (NPs) on microorganisms with environmental relevance, it is necessary to understand their interactions. In this work, they were studied the effects and the morphological interactions of two metal oxide NPs (ZnO and TiO2 ) with microorganisms, during aerobic treatment of wastewater. The effects were evaluated according to nutrient removal from wastewater, while morphological interactions were determined by three different techniques such as TEM, HAADF-STEM, as well as an elemental mapping. According to results about effects of both NPs, they inhibited the removal of organic matter and ammonia nitrogen, and enhanced the orthophosphate removal. Related to morphological interactions, the electron-dense material of both NPs was mainly observed bounded to cell membrane. In tests with ZnO NPs, it was also observed electron-dense material internalized in microorganisms without physical damage in cell membrane. The elemental mapping was useful to determine that the electron-dense material corresponded to Zn and Ti. Both interactions, internalization and attachment of NPs on cell membrane of microorganisms may trigger the negative effect in the removal of organic matter and nitrogen. © 2017 Wiley Periodicals, Inc.

  3. Triage, monitoring, and treatment of mass casualty events involving chemical, biological, radiological, or nuclear agents

    PubMed Central

    Ramesh, Aruna C.; Kumar, S.

    2010-01-01

    In a mass casualty situation due to chemical, biological, radiological, or nuclear (CBRN) event, triage is absolutely required for categorizing the casualties in accordance with medical care priorities. Dealing with a CBRN event always starts at the local level. Even before the detection and analysis of agents can be undertaken, zoning, triage, decontamination, and treatment should be initiated promptly. While applying the triage system, the available medical resources and maximal utilization of medical assets should be taken into consideration by experienced triage officers who are most familiar with the natural course of the injury presented and have detailed information on medical assets. There are several triage systems that can be applied to CBRN casualties. With no one standardized system globally or nationally available, it is important for deploying a triage and decontamination system which is easy to follow and flexible to the available medical resources, casualty number, and severity of injury. PMID:21829319

  4. Enhancing the biological performance of synthetic polymeric materials by decoration with engineered, decellularized extracellular matrix.

    PubMed

    Sadr, Nasser; Pippenger, Benjamin E; Scherberich, Arnaud; Wendt, David; Mantero, Sara; Martin, Ivan; Papadimitropoulos, Adam

    2012-07-01

    Materials based on synthetic polymers can be extensively tailored in their physical properties but often suffer from limited biological functionality. Here we tested the hypothesis that the biological performance of 3D synthetic polymer-based scaffolds can be enhanced by extracellular matrix (ECM) deposited by cells in vitro and subsequently decellularized. The hypothesis was tested in the context of bone graft substitutes, using polyesterurethane (PEU) foams and mineralized ECM laid by human mesenchymal stromal cells (hMSC). A perfusion-based bioreactor system was critically employed to uniformly seed and culture hMSC in the scaffolds and to efficiently decellularize (94% DNA reduction) the resulting ECM while preserving its main organic and inorganic components. As compared to plain PEU, the decellularized ECM-polymer hybrids supported the osteoblastic differentiation of newly seeded hMSC by up-regulating the mRNA expression of typical osteoblastic genes (6-fold higher bone sialoprotein; 4-fold higher osteocalcin and osteopontin) and increasing calcium deposition (6-fold higher), approaching the performance of ceramic-based materials. After ectopic implantation in nude mice, the decellularized hybrids induced the formation of a mineralized matrix positively immunostained for bone sialoprotein and resembling an immature osteoid tissue. Our findings consolidate the perspective of bioreactor-based production of ECM-decorated polymeric scaffolds as off-the-shelf materials combining tunable physical properties with the physiological presentation of instructive biological signals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Involvement of Intermediate Sulfur Species in Biological Reduction of Elemental Sulfur under Acidic, Hydrothermal Conditions

    PubMed Central

    Druschel, Gregory K.

    2013-01-01

    The thermoacidophile and obligate elemental sulfur (S80)-reducing anaerobe Acidilobus sulfurireducens 18D70 does not associate with bulk solid-phase sulfur during S80-dependent batch culture growth. Cyclic voltammetry indicated the production of hydrogen sulfide (H2S) as well as polysulfides after 1 day of batch growth of the organism at pH 3.0 and 81°C. The production of polysulfide is likely due to the abiotic reaction between S80 and the biologically produced H2S, as evinced by a rapid cessation of polysulfide formation when the growth temperature was decreased, inhibiting the biological production of sulfide. After an additional 5 days of growth, nanoparticulate S80 was detected in the cultivation medium, a result of the hydrolysis of polysulfides in acidic medium. To examine whether soluble polysulfides and/or nanoparticulate S80 can serve as terminal electron acceptors (TEA) supporting the growth of A. sulfurireducens, total sulfide concentration and cell density were monitored in batch cultures with S80 provided as a solid phase in the medium or with S80 sequestered in dialysis tubing. The rates of sulfide production in 7-day-old cultures with S80 sequestered in dialysis tubing with pore sizes of 12 to 14 kDa and 6 to 8 kDa were 55% and 22%, respectively, of that of cultures with S80 provided as a solid phase in the medium. These results indicate that the TEA existed in a range of particle sizes that affected its ability to diffuse through dialysis tubing of different pore sizes. Dynamic light scattering revealed that S80 particles generated through polysulfide rapidly grew in size, a rate which was influenced by the pH of the medium and the presence of organic carbon. Thus, S80 particles formed through abiological hydrolysis of polysulfide under acidic conditions appeared to serve as a growth-promoting TEA for A. sulfurireducens. PMID:23335768

  6. Microbial communities involved in biological ammonium removal from coal combustion wastewaters.

    PubMed

    Vishnivetskaya, Tatiana A; Fisher, L Suzanne; Brodie, Greg A; Phelps, Tommy J

    2013-07-01

    The efficiency of a novel integrated treatment system for biological removal of ammonium, nitrite, nitrate, and heavy metals from fossil power plant effluent was evaluated. Microbial communities were analyzed using bacterial and archaeal 16S rRNA gene clone libraries (Sanger sequences) and 454 pyrosequencing technology. While seasonal changes in microbial community composition were observed, the significant (P = 0.001) changes in bacterial and archaeal communities were consistent with variations in ammonium concentration. Phylogenetic analysis of 16S rRNA gene sequences revealed an increase of potential ammonium-oxidizing bacteria (AOB), Nitrosomonas, Nitrosococcus, Planctomycetes, and OD1, in samples with elevated ammonium concentration. Other bacteria, such as Nitrospira, Nitrococcus, Nitrobacter, Thiobacillus, ε-Proteobacteria, Firmicutes, and Acidobacteria, which play roles in nitrification and denitrification, were also detected. The AOB oxidized 56 % of the ammonium with the concomitant increase in nitrite and ultimately nitrate in the trickling filters at the beginning of the treatment system. Thermoprotei within the phylum Crenarchaeota thrived in the splitter box and especially in zero-valent iron extraction trenches, where an additional 25 % of the ammonium was removed. The potential ammonium-oxidizing Archaea (AOA) (Candidatus Nitrosocaldus) were detected towards the downstream end of the treatment system. The design of an integrated treatment system consisting of trickling filters, zero-valent iron reaction cells, settling pond, and anaerobic wetlands was efficient for the biological removal of ammonium and several other contaminants from wastewater generated at a coal burning power plant equipped with selective catalytic reducers for nitrogen oxide removal.

  7. NMR of group 2 element quadrupolar nuclei and some applications in materials science and biology

    NASA Astrophysics Data System (ADS)

    Li, Xiaohua

    1999-11-01

    For many years, NMR has provided an easy access for chemists to perform structural and kinetic studies on a whole variety of systems. To a great extent, these investigations have been restricted to non-quadrupolar nuclei. The study of quadrupolar nuclei (I > 1/2) offers the potential to gain insight into important problems in material science and biology. In addition to the large quadrupole moment associated with the spin active nuclei of interest, several of the most interesting species also possess an extremely low natural abundance. My recent research focuses on 87Sr NMR, which has been cited by earlier workers as being limited to only ionic species. Several strontium-containing compounds have been synthesized and characterized by single crystal x-ray diffraction. 87Sr NMR signals were determined for these compounds in a series of aprotic polar solvents. The chemical shift variation was found to be consistent with linen free energy relationship, which can be very useful in helping to elucidate mechanism, in predicting reaction rates, and the extent of reaction at equilibrium, and in discovering under what conditions a change in mechanism occurs. Control over symmetry of the compound was found to be the key to obtain the good NMR signals. One application of the new technique that has been developed was in the area of material science. An observation relative to sol-gel derived ionic conductors (La0.8Sr0.2Co0.8Fe0.2O 3.2) was that films often formed cracks upon pyrolysis. By careful examination of the sol-gel process by 87Sr NMR, a model for the structure of the sol was developed. Through the relaxation rate study of the strontium sites, the polymerization mechanism was determined to be predominantly bimolecular within the concentration region studied. The kinetic study of the fast cation exchange between two strontium sites indicated that the inhomogeneity of the polymeric network lads to the film cracking during pyrolysis. As a consequence of understanding the

  8. Calcium carbonate mineralization: involvement of extracellular polymeric materials isolated from calcifying bacteria.

    PubMed

    Ercole, Claudia; Bozzelli, Paola; Altieri, Fabio; Cacchio, Paola; Del Gallo, Maddalena

    2012-08-01

    This study highlights the role of specific outer bacterial structures, such as the glycocalix, in calcium carbonate crystallization in vitro. We describe the formation of calcite crystals by extracellular polymeric materials, such as exopolysaccharides (EPS) and capsular polysaccharides (CPS) isolated from Bacillus firmus and Nocardia calcarea. Organic matrices were isolated from calcifying bacteria grown on synthetic medium--in the presence or absence of calcium ions--and their effect on calcite precipitation was assessed. Scanning electron microscopy observations and energy dispersive X-ray spectrometry analysis showed that CPS and EPS fractions were involved in calcium carbonate precipitation, not only serving as nucleation sites but also through a direct role in crystal formation. The utilization of different synthetic media, with and without addition of calcium ions, influenced the biofilm production and protein profile of extracellular polymeric materials. Proteins of CPS fractions with a molecular mass between 25 and 70 kDa were overexpressed when calcium ions were present in the medium. This higher level of protein synthesis could be related to the active process of bioprecipitation.

  9. A proposal for a model of informed consent for the collection, storage and use of biological materials for research purposes.

    PubMed

    Porteri, Corinna; Borry, Pascal

    2008-04-01

    To suggest a model of informed consent for the collection, storage and use of biological materials in local biobanks for health research purposes. Review of the major ethical issues related to collection, storage and use of human biological materials for research purposes. An informed consent form for the collection and use of biological materials in a specific research project, and an informed consent form for the collection, storage and use of biological materials in a biobank were separately developed. Two main rules govern the proposed model, as follows: the informed consent for the use of biological materials shall (i) give donors sufficient information to take informed decisions about possible present and future uses of their biological materials and (ii) consider the specific biological and genetic aims of the research being performed. Even if informed consent for the collection, storage and use of biological materials is a hard process, donors can actually be provided with sufficient information and choices to give a 'really informed consent'. The proposed model can be a useful guideline for the development of specific informed consent forms to be used by researchers. It can also be a good tool to let the donors know which information and guarantees they can request from researchers.

  10. Analysis on tank truck accidents involved in road hazardous materials transportation in china.

    PubMed

    Shen, Xiaoyan; Yan, Ying; Li, Xiaonan; Xie, Chenjiang; Wang, Lihua

    2014-01-01

    Due to the sheer size and capacity of the tanker and the properties of cargo transported in the tank, hazmat tanker accidents are more disastrous than other types of vehicle accidents. The aim of this study was to provide a current survey on the situation of accidents involving tankers transporting hazardous materials in China. Detailed descriptions of 708 tanker accidents associated with hazmat transportation in China from 2004 to 2011 were analyzed to identify causes, location, types, time of occurrence, hazard class for materials involved, consequences, and the corresponding probability. Hazmat tanker accidents mainly occurred in eastern (38.1%) and southwest China (12.3%). The most frequent hazmat tanker accidents involved classes 2, 3, and 8. The predominant accident types were rollover (29.10%), run-off-the-road (16.67%), and rear-end collisions (13.28%), with a high likelihood of a large spill occurring. About 55.93% of the accidents occurred on freeways and class 1 roads, with the spill percentage reaching 75.00% and the proportion of spills that occurred in the total accidents amounting to 77.82%, of which 61.72% are considered large spills. The month with the highest accident probability was July (12.29%), and most crashes occurred during the early morning (4:00-6:00 a.m.) and midday (10:00 a.m.-12:00 p.m.) hours, 19.63% versus 16.10%. Human-related errors (73.8%) and vehicle-related defects (19.6%) were the primary reasons for hazmat tanker crashes. The most common outcomes of a hazmat tanker accident was a spill without further events (55.51%), followed by a release with fire (7.77%), and release with an explosion (2.54%). The safety situation of China's hazmat tanker transportation is grim. Such accidents not only have high spill percentages and consistently large spills but they can also cause serious consequences, such as fires and explosions. Improving the training of drivers and the quality of vehicles, deploying roll stability aids, enhancing

  11. Biological and chemical-physical properties of root-end filling materials: A comparative study

    PubMed Central

    Ceci, Matteo; Beltrami, Riccardo; Chiesa, Marco; Colombo, Marco; Poggio, Claudio

    2015-01-01

    Aim: The purpose of the study is to evaluate and compare the biological and chemical-physical properties of four different root-end filling materials. Materials and Methods: Cytotoxicity towards murine odontoblasts cells (MDPC-23) was evaluated using the Transwell insert methodology by Alamar blue test. Streptococcus salivarius, S. sanguis, and S. mutans strains were selected to evaluate the antimicrobial activity by agar disc diffusion test. Solubility was determined after 24 h and 2 months. pH values were measured after 3 and 24 h. To evaluate radiopacity, all materials were scanned on a GE Healthcare Lunar Prodigy. Results: Excellent percentage of vitality were obtained by mineral trioxide aggregate (MTA)-based materials and Biodentine. MTA-Angelus, ProRoot MTA, and Intermediate Restorative Material (IRM) showed the highest values for the inhibition zones when tested for S. mutans, while Biodentine showed the largest inhibition zone when tested for S. sanguis. All the materials fulfilled the requirements of the International Standard 6876, demonstrating low solubility with a weight loss of less than 3%. No significant reduction in pH value was demonstrated after 24 h. ProRoot MTA and MTA-Angelus showed the highest values of radiographic density. Conclusions: The differences showed by the root-end filling materials tested do not cover completely the ideal clinical requests. PMID:25829684

  12. Involvement of intermediate sulfur species in biological reduction of elemental sulfur under acidic, hydrothermal conditions.

    PubMed

    Boyd, Eric S; Druschel, Gregory K

    2013-03-01

    The thermoacidophile and obligate elemental sulfur (S(8)(0))-reducing anaerobe Acidilobus sulfurireducens 18D70 does not associate with bulk solid-phase sulfur during S(8)(0)-dependent batch culture growth. Cyclic voltammetry indicated the production of hydrogen sulfide (H(2)S) as well as polysulfides after 1 day of batch growth of the organism at pH 3.0 and 81°C. The production of polysulfide is likely due to the abiotic reaction between S(8)(0) and the biologically produced H(2)S, as evinced by a rapid cessation of polysulfide formation when the growth temperature was decreased, inhibiting the biological production of sulfide. After an additional 5 days of growth, nanoparticulate S(8)(0) was detected in the cultivation medium, a result of the hydrolysis of polysulfides in acidic medium. To examine whether soluble polysulfides and/or nanoparticulate S(8)(0) can serve as terminal electron acceptors (TEA) supporting the growth of A. sulfurireducens, total sulfide concentration and cell density were monitored in batch cultures with S(8)(0) provided as a solid phase in the medium or with S(8)(0) sequestered in dialysis tubing. The rates of sulfide production in 7-day-old cultures with S(8)(0) sequestered in dialysis tubing with pore sizes of 12 to 14 kDa and 6 to 8 kDa were 55% and 22%, respectively, of that of cultures with S(8)(0) provided as a solid phase in the medium. These results indicate that the TEA existed in a range of particle sizes that affected its ability to diffuse through dialysis tubing of different pore sizes. Dynamic light scattering revealed that S(8)(0) particles generated through polysulfide rapidly grew in size, a rate which was influenced by the pH of the medium and the presence of organic carbon. Thus, S(8)(0) particles formed through abiological hydrolysis of polysulfide under acidic conditions appeared to serve as a growth-promoting TEA for A. sulfurireducens.

  13. Activation of GPR15 and its involvement in the biological effects of smoking.

    PubMed

    Kõks, Sulev; Kõks, Gea

    2017-06-01

    Smoking is one of the most significant modifiable environmental risk factors for many diseases. Smoking causes excessive mortality worldwide. Despite decades of long research, there has not been a clear understanding regarding the molecular mechanism that makes smoking harmful to health. Some recent studies have found that smoking influences most significantly the expression and methylation of GPR15. GPR15 is an orphan receptor that is involved in the regulation of the innate immunity and the T-cell trafficking in the intestinal epithelium. Further studies have confirmed that GPR15 is very strongly involved in smoking and smoking-induced molecular changes. Therefore, the altered expression and epigenetic regulation of GPR15 could have a significant role in the health impact of smoking. Impact statement The review describes an orphan receptor GPR15 that has recently been found to be influenced by smoking. This makes GPR15 very sensitive and adequate biomarker for smoking and smoking studies. Also, activation of GPR15 by smoking could help to explain its effects on health.

  14. A metabolic model for members of the genus Tetrasphaera involved in enhanced biological phosphorus removal.

    PubMed

    Kristiansen, Rikke; Nguyen, Hien Thi Thu; Saunders, Aaron Marc; Nielsen, Jeppe Lund; Wimmer, Reinhard; Le, Vang Quy; McIlroy, Simon Jon; Petrovski, Steve; Seviour, Robert J; Calteau, Alexandra; Nielsen, Kåre Lehmann; Nielsen, Per Halkjær

    2013-03-01

    Members of the genus Tetrasphaera are considered to be putative polyphosphate accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) from wastewater. Although abundant in Danish full-scale wastewater EBPR plants, how similar their ecophysiology is to 'Candidatus Accumulibacter phosphatis' is unclear, although they may occupy different ecological niches in EBPR communities. The genomes of four Tetrasphaera isolates (T. australiensis, T. japonica, T. elongata and T. jenkinsii) were sequenced and annotated, and the data used to construct metabolic models. These models incorporate central aspects of carbon and phosphorus metabolism critical to understanding their behavior under the alternating anaerobic/aerobic conditions encountered in EBPR systems. Key features of these metabolic pathways were investigated in pure cultures, although poor growth limited their analyses to T. japonica and T. elongata. Based on the models, we propose that under anaerobic conditions the Tetrasphaera-related PAOs take up glucose and ferment this to succinate and other components. They also synthesize glycogen as a storage polymer, using energy generated from the degradation of stored polyphosphate and substrate fermentation. During the aerobic phase, the stored glycogen is catabolized to provide energy for growth and to replenish the intracellular polyphosphate reserves needed for subsequent anaerobic metabolism. They are also able to denitrify. This physiology is markedly different to that displayed by 'Candidatus Accumulibacter phosphatis', and reveals Tetrasphaera populations to be unusual and physiologically versatile PAOs carrying out denitrification, fermentation and polyphosphate accumulation.

  15. A metabolic model for members of the genus Tetrasphaera involved in enhanced biological phosphorus removal

    PubMed Central

    Kristiansen, Rikke; Nguyen, Hien Thi Thu; Saunders, Aaron Marc; Nielsen, Jeppe Lund; Wimmer, Reinhard; Le, Vang Quy; McIlroy, Simon Jon; Petrovski, Steve; Seviour, Robert J; Calteau, Alexandra; Nielsen, Kåre Lehmann; Nielsen, Per Halkjær

    2013-01-01

    Members of the genus Tetrasphaera are considered to be putative polyphosphate accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) from wastewater. Although abundant in Danish full-scale wastewater EBPR plants, how similar their ecophysiology is to ‘Candidatus Accumulibacter phosphatis' is unclear, although they may occupy different ecological niches in EBPR communities. The genomes of four Tetrasphaera isolates (T. australiensis, T. japonica, T. elongata and T. jenkinsii) were sequenced and annotated, and the data used to construct metabolic models. These models incorporate central aspects of carbon and phosphorus metabolism critical to understanding their behavior under the alternating anaerobic/aerobic conditions encountered in EBPR systems. Key features of these metabolic pathways were investigated in pure cultures, although poor growth limited their analyses to T. japonica and T. elongata. Based on the models, we propose that under anaerobic conditions the Tetrasphaera-related PAOs take up glucose and ferment this to succinate and other components. They also synthesize glycogen as a storage polymer, using energy generated from the degradation of stored polyphosphate and substrate fermentation. During the aerobic phase, the stored glycogen is catabolized to provide energy for growth and to replenish the intracellular polyphosphate reserves needed for subsequent anaerobic metabolism. They are also able to denitrify. This physiology is markedly different to that displayed by ‘Candidatus Accumulibacter phosphatis', and reveals Tetrasphaera populations to be unusual and physiologically versatile PAOs carrying out denitrification, fermentation and polyphosphate accumulation. PMID:23178666

  16. Involvement of TBL/DUF231 proteins into cell wall biology

    PubMed Central

    Selbig, Joachim; Scheible, Wolf-Rüdiger

    2010-01-01

    Through map-based cloning we determined TRICHOME BIREFRINGENCE (TBR) belongs to a plant-specific, yet anonymous gene family with 46 members in Arabidopsis thaliana. These genes all encode the domain of unknown function 231 (DUF231). TBR and its homolog TRICHOME BIREFRINGENCE-LIKE3 (TBL3) are transcriptionally coordinated with CELLULOSE SYNTHASE (CESA) genes, and loss of TBR or TBL3 results in decreased levels of crystalline secondary wall cellulose in trichomes and stems, respectively. Loss of TBR or TBL3 further results in increased pectin methylesterase (PME) activity and reduced pectin esterification in etiolated Arabidopsis hypocotyls. Together, the results suggest that DUF231 proteins might function in the maintenance of pectin- and probably homogalacturonan esterification, and that this is a requirement for normal secondary wall cellulose synthesis, at least in some tissues and organs. Here we expand the discussion about the role of TBL/DUF231 proteins in cell wall biology based on sequence and structure analyses. Our analysis revealed structural similarities of TBR with a rhamnogalacturonan acetylesterase (RGAE) of Aspergillus aculeatus and the protein LUSTRIN A-LIKE (Oryza sativa). The implications of these findings in regard to TBL functions are discussed. PMID:20657172

  17. Involvement of TBL/DUF231 proteins into cell wall biology.

    PubMed

    Bischoff, Volker; Selbig, Joachim; Scheible, Wolf-Rüdiger

    2010-08-01

    Through map-based cloning we determined TRICHOME BIREFRINGENCE (TBR) to belong to a plant-specific, yet anonymous gene family with 46 members in Arabidopsis thaliana. These genes all encode the domain of unknown function 231 (DUF231). TBR and its homolog TRICHOME BIREFRINGENCE-LIKE3 (TBL3) are transcriptionally coordinated with CELLULOSE SYNTHASE (CESA) genes, and loss of TBR or TBL3 results in decreased levels of crystalline secondary wall cellulose in trichomes and stems, respectively. Loss of TBR or TBL3 further results in increased pectin methylesterase (PME) activity and reduced pectin esterification in etiolated Arabidopsis hypocotyls. Together, the results suggest that DUF231 proteins might function in the maintenance of pectin- and probably homogalacturonan esterification, and that this is a requirement for normal secondary wall cellulose synthesis, at least in some tissues and organs. Here we expand the discussion about the role of TBL/DUF231 proteins in cell wall biology based on sequence and structure analyses. Our analysis revealed structural similarities of TBR with a rhamnogalacturonan acetylesterase (RGAE) of Aspergillus aculeatus and the protein LUSTRIN A-LIKE (Oryza sativa). The implications of these findings in regard to TBL functions are discussed.

  18. Determination of perfluorinated alkyl acid concentrations in biological standard reference materials.

    PubMed

    Reiner, Jessica L; O'Connell, Steven G; Butt, Craig M; Mabury, Scott A; Small, Jeff M; De Silva, Amila O; Muir, Derek C G; Delinsky, Amy D; Strynar, Mark J; Lindstrom, Andrew B; Reagen, William K; Malinsky, Michelle; Schäfer, Sandra; Kwadijk, Christiaan J A F; Schantz, Michele M; Keller, Jennifer M

    2012-11-01

    Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned for legacy pollutants. These SRMs can also serve as test materials for method development, method validation, and measurement for contaminants of emerging concern. Because inter-laboratory comparison studies have revealed substantial variability of measurements of perfluoroalkyl acids (PFAAs), future analytical measurements will benefit from determination of consensus values for PFAAs in SRMs to provide a means to demonstrate method-specific performance. To that end, NIST, in collaboration with other groups, has been measuring concentrations of PFAAs in a variety of SRMs. Here we report levels of PFAAs and perfluorooctane sulfonamide (PFOSA) determined in four biological SRMs: fish tissue (SRM 1946 Lake Superior Fish Tissue, SRM 1947 Lake Michigan Fish Tissue), bovine liver (SRM 1577c), and mussel tissue (SRM 2974a). We also report concentrations for three in-house quality-control materials: beluga whale liver, pygmy sperm whale liver, and white-sided dolphin liver. Measurements in SRMs show an array of PFAAs, with perfluorooctane sulfonate (PFOS) being the most frequently detected. Reference and information values are reported for PFAAs measured in these biological SRMs.

  19. Accommodating Ontologies to Biological Reality—Top-Level Categories of Cumulative-Constitutively Organized Material Entities

    PubMed Central

    Vogt, Lars; Grobe, Peter; Quast, Björn; Bartolomaeus, Thomas

    2012-01-01

    Background The Basic Formal Ontology (BFO) is a top-level formal foundational ontology for the biomedical domain. It has been developed with the purpose to serve as an ontologically consistent template for top-level categories of application oriented and domain reference ontologies within the Open Biological and Biomedical Ontologies Foundry (OBO). BFO is important for enabling OBO ontologies to facilitate in reliably communicating and managing data and metadata within and across biomedical databases. Following its intended single inheritance policy, BFO's three top-level categories of material entity (i.e. ‘object’, ‘fiat object part’, ‘object aggregate’) must be exhaustive and mutually disjoint. We have shown elsewhere that for accommodating all types of constitutively organized material entities, BFO must be extended by additional categories of material entity. Methodology/Principal Findings Unfortunately, most biomedical material entities are cumulative-constitutively organized. We show that even the extended BFO does not exhaustively cover cumulative-constitutively organized material entities. We provide examples from biology and everyday life that demonstrate the necessity for ‘portion of matter’ as another material building block. This implies the necessity for further extending BFO by ‘portion of matter’ as well as three additional categories that possess portions of matter as aggregate components. These extensions are necessary if the basic assumption that all parts that share the same granularity level exhaustively sum to the whole should also apply to cumulative-constitutively organized material entities. By suggesting a notion of granular representation we provide a way to maintain the single inheritance principle when dealing with cumulative-constitutively organized material entities. Conclusions/Significance We suggest to extend BFO to incorporate additional categories of material entity and to rearrange its top-level material

  20. Identification of genes involved in the biology of atypical teratoid/rhabdoid tumours using Drosophila melanogaster

    NASA Astrophysics Data System (ADS)

    Jeibmann, Astrid; Eikmeier, Kristin; Linge, Anna; Kool, Marcel; Koos, Björn; Schulz, Jacqueline; Albrecht, Stefanie; Bartelheim, Kerstin; Frühwald, Michael C.; Pfister, Stefan M.; Paulus, Werner; Hasselblatt, Martin

    2014-06-01

    Atypical teratoid/rhabdoid tumours (AT/RT) are malignant brain tumours. Unlike most other human brain tumours, AT/RT are characterized by inactivation of one single gene, SMARCB1. SMARCB1 is a member of the evolutionarily conserved SWI/SNF chromatin remodelling complex, which has an important role in the control of cell differentiation and proliferation. Little is known, however, about the pathways involved in the oncogenic effects of SMARCB1 inactivation, which might also represent targets for treatment. Here we report a comprehensive genetic screen in the fruit fly that revealed several genes not yet associated with loss of snr1, the Drosophila homologue of SMARCB1. We confirm the functional role of identified genes (including merlin, kibra and expanded, known to regulate hippo signalling pathway activity) in human rhabdoid tumour cell lines and AT/RT tumour samples. These results demonstrate that fly models can be employed for the identification of clinically relevant pathways in human cancer.

  1. Development and Applications Of Photosensitive Device Systems To Studies Of Biological And Organic Materials

    SciTech Connect

    Gruner, Sol

    2012-01-20

    The primary focus of the grant is the development of new x-ray detectors for biological and materials work at synchrotron sources, especially Pixel Array Detectors (PADs), and the training of students via research applications to problems in biophysics and materials science using novel x-ray methods. This Final Progress Report provides a high-level overview of the most important accomplishments. These major areas of accomplishment include: (1) Development and application of x-ray Pixel Array Detectors; (2) Development and application of methods of high pressure x-ray crystallography as applied to proteins; (3) Studies on the synthesis and structure of novel mesophase materials derived from block co-polymers.

  2. Designing and Developing Online Materials for Molecular Biology: Building Online Programs for Science

    PubMed Central

    Boulay, Rachel

    2013-01-01

    A well-accepted form of educational training offered in molecular biology is internships in research laboratories. However, the number of available research laboratories severely limits access by most students. Addressing this need, the University of Hawaii launched a project to expand this model to include newly developed online training materials in addition to a hands-on laboratory experience. This paper explores the design and development process of the online learning materials. This case study looks at the roles of the instructional designer, multimedia specialist, and research faculty who were the subject matter experts. The experiences of the design teams are shared in an effort to gain insight on how the collaborative efforts of the project group led to a successful deployment of the online learning materials. PMID:24319699

  3. Temperature response of biological materials to pulsed non-ablative CO2 laser irradiation.

    PubMed

    Brugmans, M J; Kemper, J; Gijsbers, G H; van der Meulen, F W; van Gemert, M J

    1991-01-01

    This paper presents surface temperature responses of various tissue phantoms and in vitro and in vivo biological materials in air to non-ablative pulsed CO2 laser irradiation, measured with a thermocamera. We studied cooling off behavior of the materials after a laser pulse, to come to an understanding of heat accumulation and related thermal damage during (super) pulsed CO2 laser irradiation. The experiments show a very slow decay of temperatures in the longer time regime. This behavior is well predicted by a simple model for one-dimensional heat flow that considers the CO2 laser radiation as producing a heat flux on the material surface. The critical pulse repetition frequency for which temperature accumulation is sufficiently low is estimated at about 5 Hz. Although we have not investigated the ablative situation, our results suggest that very low pulse frequencies in microsurgical procedures may be recommended.

  4. Designing and Developing Online Materials for Molecular Biology: Building Online Programs for Science.

    PubMed

    Boulay, Rachel

    2013-01-01

    A well-accepted form of educational training offered in molecular biology is internships in research laboratories. However, the number of available research laboratories severely limits access by most students. Addressing this need, the University of Hawaii launched a project to expand this model to include newly developed online training materials in addition to a hands-on laboratory experience. This paper explores the design and development process of the online learning materials. This case study looks at the roles of the instructional designer, multimedia specialist, and research faculty who were the subject matter experts. The experiences of the design teams are shared in an effort to gain insight on how the collaborative efforts of the project group led to a successful deployment of the online learning materials.

  5. Karyopherins: potential biological elements involved in the delayed graft function in renal transplant recipients

    PubMed Central

    2014-01-01

    Background Immediately after renal transplantation, patients experience rapid and significant improvement of their clinical conditions and undergo considerable systemic and cellular modifications. However, some patients present a slow recovery of the renal function commonly defined as delayed graft function (DGF). Although clinically well characterized, the molecular mechanisms underlying this condition are not totally defined, thus, we are currently missing specific clinical markers to predict and to make early diagnosis of this event. Methods We investigated, using a pathway analysis approach, the transcriptomic profile of peripheral blood mononuclear cells (PBMC) from renal transplant recipients with DGF and with early graft function (EGF), before (T0) and 24 hours (T24) after transplantation. Results Bioinformatics/statistical analysis showed that 15 pathways (8 up-regulated and 7 down-regulated) and 11 pathways (5 up-regulated and 6 down-regulated) were able to identify DGF patients at T0 and T24, respectively. Interestingly, the most up-regulated pathway at both time points was NLS-bearing substrate import into nucleus, which includes genes encoding for several subtypes of karyopherins, a group of proteins involved in nucleocytoplasmic transport. Signal transducers and activators of transcription (STAT) utilize karyopherins-alpha (KPNA) for their passage from cytoplasm into the nucleus. In vitro functional analysis demonstrated that in PBMCs of DGF patients, there was a significant KPNA-mediated nuclear translocation of the phosphorylated form of STAT3 (pSTAT3) after short-time stimulation (2 and 5 minutes) with interleukin-6. Conclusions Our study suggests the involvement, immediately before transplantation, of karyopherin-mediated nuclear transport in the onset and development of DGF. Additionally, it reveals that karyopherins could be good candidates as potential DGF predictive clinical biomarkers and targets for pharmacological interventions in renal

  6. Population dynamics of bacteria involved in enhanced biological phosphorus removal in Danish wastewater treatment plants.

    PubMed

    Mielczarek, Artur Tomasz; Nguyen, Hien Thi Thu; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2013-03-15

    The enhanced biological phosphorus removal (EBPR) process is increasingly popular as a sustainable method for removal of phosphorus (P) from wastewater. This study consisted of a comprehensive three-year investigation of the identity and population dynamics of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in 28 Danish municipal wastewater treatment plants with nutrient removal. Fluorescence in situ hybridization was applied to quantify ten probe-defined populations of PAO and GAO that in total constituted a large fraction (30% on average) of the entire microbial community targeted by the EUBmix probes. Two PAO genera, Accumulibacter and Tetrasphaera, were very abundant in all EBPR plants (average of 3.7% and 27% of all bacteria, respectively), and their abundance was relatively stable in the Danish full-scale plants without clear temporal variations. GAOs were occasionally present in some plants (Competibacter in 11 plants, Defluviicoccus in 6 plants) and were consistent in only a few plants. This shows that these were not core species in the EBPR communities. The total GAO abundance was always lower than that of Accumulibacter. In plants without EBPR design, the abundance of PAO and GAO was significantly lower. Competibacter correlated in general with high fraction of industrial wastewater. In specific plants Accumulibacter correlated with high C/P ratio of the wastewater and Tetrasphaera with high organic loading. Interestingly, the relative microbial composition of the PAO/GAO species was unique to each plant over time, which gives a characteristic plant-specific "fingerprint". Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Determination of aluminum and silicon in biological materials by inductively coupled plasma atomic emission spectrometry with electrothermal vaporization

    NASA Astrophysics Data System (ADS)

    Matusiewicz, Henryk; Barnes, Ramon M.

    An atomic emission spectrometric method is described for the determination of trace elements in microvolume samples especially of biological materials. Based upon the arrangement of a commercial electrothermal vaporizer and a 40-MHz inductively coupled plasma, the direct determination of aluminum and silicon in human body fluids such as urine and serum and aluminum in hemodialysis solution is performed. The instrumental system involves vaporizing the sample from a modified graphite electrode followed by atomization and excitation of the vapors in the ICP discharge. Compromise experimental conditions are reported and calibration functions compared. Limits of detection in 5-μl samples were 8 pg Al and 2.5 ng Si, and after preconcentration of Al with a poly(acrylamidoxime) resin, the detection limit was 1 pg Al. Recovery of 5 μg Si/ml and 10 ng Al/ml from aqueous and synthetic standards was 80-85% and 96-103%, respectively.

  8. A preconcentration procedure for the determination of cadmium in biological material after on-line cloud point extraction.

    PubMed

    Baliza, Patrícia Xavier; Cardoso, Luiz Augusto Martins; Lemos, Valfredo Azevedo

    2012-07-01

    In this paper, a method involving on-line preconcentration with cloud point extraction for the determination of cadmium in biological samples is presented. The procedure is based on the sorption of micelles containing Cd(II) ions and the reagent 4-(5'-bromo-2'-thiazolylazo)orcinol (Br-TAO) in a minicolumn packed with polyester. The surfactant Triton X-114 was used in the formation of micelles. After sorption, the Cd(II) ions were desorbed from the minicolumn with acid eluent and determined by flame atomic absorption spectrometry. Parameters influencing the cloud point extraction were studied. The method showed a detection limit of 0.5 μg l(-1) and an enhancement factor of 27. The accuracy was tested by determination of cadmium in certified reference materials (spinach leaves 1570a and tomato leaves 1573a) from the National Institute of Standards and Technology.

  9. Biological and chemical-physical properties of root-end filling materials: A comparative study.

    PubMed

    Ceci, Matteo; Beltrami, Riccardo; Chiesa, Marco; Colombo, Marco; Poggio, Claudio

    2015-01-01

    The purpose of the study is to evaluate and compare the biological and chemical-physical properties of four different root-end filling materials. Cytotoxicity towards murine odontoblasts cells (MDPC-23) was evaluated using the Transwell insert methodology by Alamar blue test. Streptococcus salivarius, S. sanguis, and S. mutans strains were selected to evaluate the antimicrobial activity by agar disc diffusion test. Solubility was determined after 24 h and 2 months. pH values were measured after 3 and 24 h. To evaluate radiopacity, all materials were scanned on a GE Healthcare Lunar Prodigy. Excellent percentage of vitality were obtained by mineral trioxide aggregate (MTA)-based materials and Biodentine. MTA-Angelus, ProRoot MTA, and Intermediate Restorative Material (IRM) showed the highest values for the inhibition zones when tested for S. mutans, while Biodentine showed the largest inhibition zone when tested for S. sanguis. All the materials fulfilled the requirements of the International Standard 6876, demonstrating low solubility with a weight loss of less than 3%. No significant reduction in pH value was demonstrated after 24 h. ProRoot MTA and MTA-Angelus showed the highest values of radiographic density. The differences showed by the root-end filling materials tested do not cover completely the ideal clinical requests.

  10. Investigation of the stability of aromatic hydrazones in plasma and related biological material.

    PubMed

    Kovaríková, Petra; Mrkvicková, Zlata; Klimes, Jirí

    2008-06-09

    Novel aromatic hydrazones derived from pyridoxal isonicotinoyl hydrazone (PIH) are interesting compounds from the viewpoint of their pharmacodynamic activity. However, they were recently shown to suffer from relatively short biological half-lives. The purpose of the present study was to investigate the stability of novel aroylhydrazones in plasma and related biological media in order to reveal its potential involvement in the pharmacokinetics of these drugs. Three different aroylhydrazones (pyridoxal isonicotinoyl hydrazone - PIH, salicylaldehyde isonicotinoyl hydrazone - SIH and pyridoxal 2-chlorobenzoyl hydrazone - o-108) were incubated in plasma from different species, plasma ultrafiltrate, bovine serum albumin, RPMI cell medium and phosphate buffer saline (PBS) at 37 degrees C. Stability of these compounds was determined using precise, selective and validated HPLC methods. Although the aroylhydrazones were relatively stable in PBS, they underwent rapid degradation in plasma. Plasma proteins as well as low molecular weight components were involved in this matter. Furthermore, the products of hydrazone bond splitting revealed in this study were also found in the chromatograms from pharmacokinetic experiments. In the light of short biological half-lives determined in vivo, these in vitro findings strongly suggest that hydrolysis of investigated aromatic hydrazones in plasma could have a significant impact on their pharmacokinetics. Furthermore, these results also suggest that plasma stability of other novel drug candidates containing the hydrazone bond deserves to be considered.

  11. [Peculiarities of detection of 4-nitro-3-(trifluoromethyl)-aniline in the biological material].

    PubMed

    Shormanov, V K; Andreeva, Yu V; Omel'chenko, V A

    2016-01-01

    The objective of the present work was to study peculiarities of detection of 4-nitro-3-(trifluoromethyl)-aniline in the biological material with the use of TLC, GC-MS, and electron spectrophotometry. We have proposed the rationale for the application of acetone as an insulating agent for the extraction of 4-nitro-3-(trifluoromethyl)-aniline from the cadaveric hepatic tissue and biological fluids. It was shown that this compound is possible to separate from endogenous biomaterials on the silicagel L column (40/100 mcm). The results of the quantitative evaluation of different amounts of 4-nitro-3-(trifluoromethyl)-aniline in the cadaveric hepatic tissue, blood, plasma, and urine are presented. The proposed method makes it possible to determine a minimum of 0.12 mg of 4-nitro-3-(trifluoromethyl)-aniline in 100 g of the biological material (cadaveric hepatic tissue), 0.09 mg in 100 g of blood, 0.06 mg and 0.05 mg in 100 u of plasma and urine respectively.

  12. Holographic femtosecond laser processing and its application to biological materials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hayasaki, Yoshio

    2017-02-01

    Femtosecond laser processing is a promising tool for fabricating novel and useful structures on the surfaces of and inside materials. An enormous number of pulse irradiation points will be required for fabricating actual structures with millimeter scale, and therefore, the throughput of femtosecond laser processing must be improved for practical adoption of this technique. One promising method to improve throughput is parallel pulse generation based on a computer-generated hologram (CGH) displayed on a spatial light modulator (SLM), a technique called holographic femtosecond laser processing. The holographic method has the advantages such as high throughput, high light use efficiency, and variable, instantaneous, and 3D patterning. Furthermore, the use of an SLM gives an ability to correct unknown imperfections of the optical system and inhomogeneity in a sample using in-system optimization of the CGH. Furthermore, the CGH can adaptively compensate in response to dynamic unpredictable mechanical movements, air and liquid disturbances, a shape variation and deformation of the target sample, as well as adaptive wavefront control for environmental changes. Therefore, it is a powerful tool for the fabrication of biological cells and tissues, because they have free form, variable, and deformable structures. In this paper, we present the principle and the experimental setup of holographic femtosecond laser processing, and the effective way for processing the biological sample. We demonstrate the femtosecond laser processing of biological materials and the processing properties.

  13. The biological safety of condom material can be determined using an in vitro cell culture system.

    PubMed

    Motsoane, N A; Pretorius, E; Bester, M J; Becker, P J

    2001-01-01

    Latex products have long been recognized as a cause of latex protein allergy. The increased usage of latex gloves, with the consequent increased occurrence of latex allergies appears to have escalated with increasing awareness of the transmission of HIV-AIDS and other infections. The use of condoms as a means to prevent the transmission of STD's (sexually transmitted diseases) and HIV-AIDS has been widely promoted. Although extensive testing is done to evaluate the physical quality of condoms, no information is available regarding the biological safety of condoms. This study was undertaken to determine the effects of short-term exposure to physiological levels of condom surface material on cell viability (MTT assay) and cell growth (crystal violet assay). A direct contact cell culture testing method (FDA test method F813-83 used to evaluate the cytotoxic potential of medical materials and devices) was used. The modified test method was found to be a sensitive test system for the evaluation of the biological safety of condoms. This study reveals the importance of evaluating the biological safety of all condoms that are commercially available, because of the potential health risk that may be associated with prolonged use of certain types of condoms.

  14. Enhanced Removal of Lead by Chemically and Biologically Treated Carbonaceous Materials

    PubMed Central

    Mahmoud, Mohamed E.; Osman, Maher M.; Ahmed, Somia B.; Abdel-Fattah, Tarek M.

    2012-01-01

    Hybrid sorbents and biosorbents were synthesized via chemical and biological treatment of active carbon by simple and direct redox reaction followed by surface loading of baker's yeast. Surface functionality and morphology of chemically and biologically modified sorbents and biosorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Hybrid carbonaceous sorbents and biosorbents were characterized by excellent efficiency and superiority toward lead(II) sorption compared to blank active carbon providing a maximum sorption capacity of lead(II) ion as 500 μmol g−1. Sorption processes of lead(II) by these hybrid materials were investigated under the influence of several controlling parameters such as pH, contact time, mass of sorbent and biosorbent, lead(II) concentration, and foreign ions. Lead(II) sorption mechanisms were found to obey the Langmuir and BET isotherm models. The potential applications of chemically and biologically modified-active carbonaceous materials for removal and extraction of lead from real water matrices were also studied via a double-stage microcolumn technique. The results of this study were found to denote to superior recovery values of lead (95.0–99.0 ± 3.0–5.0%) by various carbonaceous-modified-bakers yeast biosorbents. PMID:22629157

  15. System biology analysis of cell cycle pathway involved in hepatocellular carcinoma.

    PubMed

    Sun, Meiqian; Mo, Wenjuan; Fu, Xuping; Wu, Gang; Huang, Yan; Tang, Rong; Guo, Yi; Qiu, Minyan; Zhao, Feng; Li, Lin; Huang, Shengdong; Mao, Yumin; Li, Yao; Xie, Yi

    2010-06-01

    To investigate genetic mechanisms of hepatocarcinogenesis and identify potential anticancer targets in hepatocellular carcinoma (HCC), we analyzed microarray gene expression profiles between 33 HCCs and their corresponding noncancerous liver tissues. Functional analysis of differentially-expressed genes in HCC indicated that cell cycle dysregulation plays an important role in hepatocarcinogenesis. Based on 14 differentially-expressed genes involved in cell cycle in HCC, we applied Structural Equation Modeling (SEM) to establish a potential genetic network which could assist understanding of HCC molecular mechanisms. siRNA-mediated knock-down of two significantly up-regulated genes, minichromosome maintenance protein 2 (MCM2) and cyclin B1 (CCNB1), in HCC cells (SMMC-7721 and QGY-7703) induced G2/M-phase arrest, apoptosis and antiproliferation in HCC. Some up-regulated cell cycle-related genes in HCC were down-regulated following specific depletion of MCM2 or/and CCNB1 in HCC cells, which might well validate and complement the reconstructed cell cycle network. This study may contribute to further disclose hepatocarcinogenesis mechanism through systematically analyzed the HCC-related-cell-cycle pathway. This study also shows that MCM2 and CCNB1 could be promising prognostic and therapeutic targets for HCC.

  16. Systems biology study of transcriptional and post-transcriptional co-regulatory network sheds light on key regulators involved in important biological processes in Citrus sinensis.

    PubMed

    Khodadadi, Ehsan; Mehrabi, Ali Ashraf; Najafi, Ali; Rastad, Saber; Masoudi-Nejad, Ali

    2017-04-01

    Transcriptional and post-transcriptional regulators including transcription regulator, transcription factor and miRNA are the main endogenous molecular elements which control complex cellular mechanisms such as development, growth and response to biotic and abiotic stresses in a coordinated manner in plants. Utilizing the most recent information on such relationships in a plant species, obtained from high-throughput experimental technologies and advanced computational tools, we can reconstruct its co-regulatory network which consequently sheds light on key regulators involved in its important biological processes. In this article, combined systems biology approaches such as mining the literatures, various databases and network reconstruction, analysis, and visualization tools were employed to infer and visualize the coregulatory relationships between miRNAs and transcriptional regulators in Citrus sinensis. Using computationally and experimentally verified miRNA-target interactions and constructed co-expression networks on array-based data, 10 coregulatory networks and 10 corresponding subgraphs include FFL motifs were obtained for 10 distinct tissues/conditions. Then PPI subnetworks were extracted for transcripts/genes included in mentioned subgraphs in order to the functional analysis of extracted coregulatory circuits. These proposed coregulatory connections shed light on precisely identifying C. sinensis metabolic pathways key switches, which are demanded for ultimate goals such as genome editing.

  17. Waste-Activated Sludge Fermentation for Polyacrylamide Biodegradation Improved by Anaerobic Hydrolysis and Key Microorganisms Involved in Biological Polyacrylamide Removal

    PubMed Central

    Dai, Xiaohu; Luo, Fan; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dong, Bin

    2015-01-01

    During the anaerobic digestion of dewatered sludge, polyacrylamide (PAM), a chemical conditioner, can usually be consumed as a carbon and nitrogen source along with other organic matter (e.g., proteins and carbohydrates in the sludge). However, a significant accumulation of acrylamide monomers (AMs) was observed during the PAM biodegradation process. To improve the anaerobic hydrolysis of PAM, especially the amide hydrolysis process, and to avoid the generation of the intermediate product AM, a new strategy is reported herein that uses an initial pH of 9, 200 mg COD/L of PAM and a fermentation time of 17 d. First, response surface methodology (RSM) was applied to optimize PAM removal in the anaerobic digestion of the sludge. The biological hydrolysis of PAM reached 86.64% under the optimal conditions obtained from the RSM. Then, the mechanisms for the optimized parameters that significantly improved the biological hydrolysis of PAM were investigated by the synergistic effect of the main organic compounds in the sludge, the floc size distribution, and the enzymatic activities. Finally, semi-continuous-flow experiments for a microbial community study were investigated based on the determination of key microorganisms involved in the biological hydrolysis of PAM. PMID:26144551

  18. Waste-Activated Sludge Fermentation for Polyacrylamide Biodegradation Improved by Anaerobic Hydrolysis and Key Microorganisms Involved in Biological Polyacrylamide Removal.

    PubMed

    Dai, Xiaohu; Luo, Fan; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dong, Bin

    2015-07-06

    During the anaerobic digestion of dewatered sludge, polyacrylamide (PAM), a chemical conditioner, can usually be consumed as a carbon and nitrogen source along with other organic matter (e.g., proteins and carbohydrates in the sludge). However, a significant accumulation of acrylamide monomers (AMs) was observed during the PAM biodegradation process. To improve the anaerobic hydrolysis of PAM, especially the amide hydrolysis process, and to avoid the generation of the intermediate product AM, a new strategy is reported herein that uses an initial pH of 9, 200 mg COD/L of PAM and a fermentation time of 17 d. First, response surface methodology (RSM) was applied to optimize PAM removal in the anaerobic digestion of the sludge. The biological hydrolysis of PAM reached 86.64% under the optimal conditions obtained from the RSM. Then, the mechanisms for the optimized parameters that significantly improved the biological hydrolysis of PAM were investigated by the synergistic effect of the main organic compounds in the sludge, the floc size distribution, and the enzymatic activities. Finally, semi-continuous-flow experiments for a microbial community study were investigated based on the determination of key microorganisms involved in the biological hydrolysis of PAM.

  19. Development of Standards for NanoSIMS Analyses of Biological Materials

    SciTech Connect

    Davission, M L; Weber, P K; Pett-Ridge, J; Singer, S

    2008-07-31

    NanoSIMS is a powerful analytical technique for investigating element distributions at the nanometer scale, but quantifying elemental abundances requires appropriate standards, which are not readily available for biological materials. Standards for trace element analyses have been extensively developed for secondary ion mass spectrometry (SIMS) in the semiconductor industry and in the geological sciences. The three primary approaches for generating standards for SIMS are: (1) ion implantation (2) using previously characterized natural materials, and (3) preparing synthetic substances. Ion implantation is a reliable method for generating trace element standards, but it is expensive, which limits investigation of the analytical issues discussed above. It also requires low background levels of the elements of interest. Finding or making standard materials has the potential to provide more flexibility than ion implantation, but realizing homogeneity at the nano-scale is in itself a significant challenge. In this study, we experiment with all three approaches, but with an emphasis toward synthetic organic polymers in order to reduce costs, increase flexibility, and achieve a wide dynamic concentration range. This emphasis serves to meet the major challenge for biological samples of identifying matrix matched, homogeneous material. Biological samples themselves are typically heterogeneous at the scale of microns to 100s of microns, and therefore they are poor SIMS standards. Therefore, we focused on identifying 'biological-like' materials--either natural or synthetic--that can be used for standards. The primary criterion is that the material be as compositionally similar to biological samples as possible (primarily C, H, O, and N). For natural material we adsorbed organic colloids consisting of peptidoglycan (i.e., amino sugars), activated charcoal, and humic acids. Experiments conducted with Si on peptidoglycan showed low affinity as SiO{sub 2}, yet its distribution in

  20. Marketing the use of the space environment for the processing of biological and pharmaceutical materials

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The perceptions of U.S. biotechnology and pharmaceutical companies concerning the potential use of the space environment for the processing of biological substances was examined. Physical phenomena that may be important in space-base processing of biological materials are identified and discussed in the context of past and current experiment programs. The capabilities of NASA to support future research and development, and to engage in cooperative risk sharing programs with industry are discussed. Meetings were held with several biotechnology and pharmaceutical companies to provide data for an analysis of the attitudes and perceptions of these industries toward the use of the space environment. Recommendations are made for actions that might be taken by NASA to facilitate the marketing of the use of the space environment, and in particular the Space Shuttle, to the biotechnology and pharmaceutical industries.

  1. Damage-free vibrational spectroscopy of biological materials in the electron microscope

    SciTech Connect

    Rez, Peter; Aoki, Toshihiro; March, Katia; Gur, Dvir; Krivanek, Ondrej L.; Dellby, Niklas; Lovejoy, Tracy C.; Wolf, Sharon G.; Cohen, Hagai

    2016-03-10

    Vibrational spectroscopy in the electron microscope would be transformative in the study of biological samples, provided that radiation damage could be prevented. However, electron beams typically create high-energy excitations that severely accelerate sample degradation. Here this major difficulty is overcome using an ‘aloof’ electron beam, positioned tens of nanometres away from the sample: high-energy excitations are suppressed, while vibrational modes of energies o1 eV can be ‘safely’ investigated. To demonstrate the potential of aloof spectroscopy, we record electron energy loss spectra from biogenic guanine crystals in their native state, resolving their characteristic C–H, N–H and C=O vibrational signatures with no observable radiation damage. Furthermore, the technique opens up the possibility of non-damaging compositional analyses of organic functional groups, including non-crystalline biological materials, at a spatial resolution of ~10nm, simultaneously combined with imaging in the electron microscope.

  2. Damage-free vibrational spectroscopy of biological materials in the electron microscope

    PubMed Central

    Rez, Peter; Aoki, Toshihiro; March, Katia; Gur, Dvir; Krivanek, Ondrej L.; Dellby, Niklas; Lovejoy, Tracy C.; Wolf, Sharon G.; Cohen, Hagai

    2016-01-01

    Vibrational spectroscopy in the electron microscope would be transformative in the study of biological samples, provided that radiation damage could be prevented. However, electron beams typically create high-energy excitations that severely accelerate sample degradation. Here this major difficulty is overcome using an ‘aloof' electron beam, positioned tens of nanometres away from the sample: high-energy excitations are suppressed, while vibrational modes of energies <1 eV can be ‘safely' investigated. To demonstrate the potential of aloof spectroscopy, we record electron energy loss spectra from biogenic guanine crystals in their native state, resolving their characteristic C–H, N–H and C=O vibrational signatures with no observable radiation damage. The technique opens up the possibility of non-damaging compositional analyses of organic functional groups, including non-crystalline biological materials, at a spatial resolution of ∼10 nm, simultaneously combined with imaging in the electron microscope. PMID:26961578

  3. Imaging of Biological Materials and Cells by X-ray Scattering and Diffraction.

    PubMed

    Hémonnot, Clément Y J; Köster, Sarah

    2017-09-26

    Cells and biological materials are large objects in comparison to the size of internal components such as organelles and proteins. An understanding of the functions of these nanoscale elements is key to elucidating cellular function. In this review, we describe the advances in X-ray scattering and diffraction techniques for imaging biological systems at the nanoscale. We present a number of principal technological advances in X-ray optics and development of sample environments. We identify radiation damage as one of the most severe challenges in the field, thus rendering the dose an important parameter when putting different X-ray methods in perspective. Furthermore, we describe different successful approaches, including scanning and full-field techniques, along with prominent examples. Finally, we present a few recent studies that combined several techniques in one experiment in order to collect highly complementary data for a multidimensional sample characterization.

  4. Matrix Assisted Ionization Vacuum (MAIV), a New Ionization Method for Biological Materials Analysis Using Mass Spectrometry*

    PubMed Central

    Inutan, Ellen D.; Trimpin, Sarah

    2013-01-01

    The introduction of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) for the mass spectrometric analysis of peptides and proteins had a dramatic impact on biological science. We now report that a wide variety of compounds, including peptides, proteins, and protein complexes, are transported directly from a solid-state small molecule matrix to gas-phase ions when placed into the vacuum of a mass spectrometer without the use of high voltage, a laser, or added heat. This ionization process produces ions having charge states similar to ESI, making the method applicable for high performance mass spectrometers designed for atmospheric pressure ionization. We demonstrate highly sensitive ionization using intermediate pressure MALDI and modified ESI sources. This matrix and vacuum assisted soft ionization method is suitable for the direct surface analysis of biological materials, including tissue, via mass spectrometry. PMID:23242551

  5. Assessing non-response to a mailed health survey including self-collection of biological material.

    PubMed

    Uusküla, Anneli; Kals, Mart; McNutt, Louise-Anne

    2011-08-01

    Collection of biological material via mailed health surveys is an emerging trend. This study was conducted to assess non-response bias in a study of sexually transmitted infection utilizing self-collected, home-obtained specimens. Data from a nationwide administrative database on health care utilization together with data from a research study were used. The research study was an outreach screening programme including home-obtained, participant-collected, mail-delivered testing for Chlamydia trachomatis. A random sample of 1690 persons aged 18-35 years from the population registry was selected. Study materials (specimen collection kit, informed consent, questionnaire) were mailed in three waves. The first mailing yielded a response rate of 18.5% (n = 259), the second 10.1% (n = 141) and the third 11.4% (n = 160). Women were more likely to respond than men, and responders were less likely to have had medical care in the past year and more likely to have had a prior sexually transmitted infection than non-responders. Chlamydia trachomatis infection rates tended to be higher in early responders. Late responders appeared more like non-responders in terms of demographic factors, health care utilization patterns and potential disease status. Non-response in a health survey including biological material self-collection warrants research as it may differ from non-response in general health questionnaires.

  6. Biomolecular Interactions and Biological Responses of Emerging Two-Dimensional Materials and Aromatic Amino Acid Complexes.

    PubMed

    Mallineni, Sai Sunil Kumar; Shannahan, Jonathan; Raghavendra, Achyut J; Rao, Apparao M; Brown, Jared M; Podila, Ramakrishna

    2016-07-06

    The present work experimentally investigates the interaction of aromatic amino acids viz., tyrosine, tryptophan, and phenylalnine with novel two-dimensional (2D) materials including graphene, graphene oxide (GO), and boron nitride (BN). Photoluminescence, micro-Raman spectroscopy, and cyclic voltammetry were employed to investigate the nature of interactions and possible charge transfer between 2D materials and amino acids. Graphene and GO were found to interact strongly with aromatic amino acids through π-π stacking, charge transfer, and H-bonding. Particularly, it was observed that both physi and chemisorption are prominent in the interactions of GO/graphene with phenylalanine and tryptophan while tyrosine exhibited strong chemisorption on graphene and GO. In contrast, BN exhibited little or no interactions, which could be attributed to localized π-electron clouds around N atoms in BN lattice. Lastly, the adsorption of amino acids on 2D materials was observed to considerably change their biological response in terms of reactive oxygen species generation. More importantly, these changes in the biological response followed the same trends observed in the physi and chemisorption measurements.

  7. "Rinse and trickle": a protocol for TEM preparation and investigation of inorganic fibers from biological material.

    PubMed

    Vigliaturo, Ruggero; Capella, Silvana; Rinaudo, Caterina; Belluso, Elena

    2016-07-01

    The purpose of this work is to define a sample preparation protocol that allows inorganic fibers and particulate matter extracted from different biological samples to be characterized morphologically, crystallographically and chemically by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). The method does not damage or create artifacts through chemical attacks of the target material. A fairly rapid specimen preparation is applied with the aim of performing as few steps as possible to transfer the withdrawn inorganic matter onto the TEM grid. The biological sample is previously digested chemically by NaClO. The salt is then removed through a series of centrifugation and rinse cycles in deionized water, thus drastically reducing the digestive power of the NaClO and concentrating the fibers for TEM analysis. The concept of equivalent hydrodynamic diameter is introduced to calculate the settling velocity during the centrifugation cycles. This technique is applicable to lung tissues and can be extended to a wide range of organic materials. The procedure does not appear to cause morphological damage to the fibers or modify their chemistry or degree of crystallinity. The extrapolated data can be used in interdisciplinary studies to understand the pathological effects caused by inorganic materials.

  8. Nanoparticles to increase adhesive properties of biologically secreted materials for surface affixing.

    PubMed

    Zhang, Mingjun; Liu, Maozi; Bewick, Sharon; Suo, Zhiyong

    2009-06-01

    Surface adhesion in nature has been the focus of intense study over the past few years. Nevertheless, research in this field has primarily concentrated on understanding the chemical aspects of adhesion. While scientists have been able to determine some of the molecular structures present in the adhesives secreted by surface climbing or surface affixing biological systems such as mussels and barnacles, the fundamental adhesion mechanisms used by these systems are still unknown. This research paper focuses on the nano-scale morphological similarities of adhesive materials secreted from marine mussels, barnacles and ivy. We discovered that marine mussels secrete large amounts of adhesive materials in the form of nanoparticles for surface adhesion. This is in keeping with our previous work, which indicated a similar phenomenon for ivy. Both studies concur with earlier research on marine barnacles, polychaetes and sea stars. Taken together, these results indicate that nanoparticles are used by natural, biological systems to increase surface adhesion. These nanoparticle surface adhesion mechanisms have important implications in terms of engineering surface adhesive materials and devices.

  9. Biological and Biomimetic Low-Temperature Routes to Materials for Energy Applications

    SciTech Connect

    Morse, Daniel E.

    2016-08-29

    New materials are needed to significantly improve the efficiencies of energy harnessing, transduction and storage, yet the synthesis of advanced composites and multi-metallic semiconductors with nanostructures optimized for these functions remains poorly understood and even less well controlled. To help address this need, we proposed three goals: (1) to further investigate the hierarchical structure of the biologically synthesized silica comprising the skeletal spicules of sponges that we discovered, to better resolve the role and mechanism of templating by the hierarchically assembled silicatein protein filament; (2) to extend our molecular and genetic analyses and engineering of silicatein, the self-assembling, structure-directing, silica-synthesizing enzyme we discovered and characterized, to better understand and manipulate the catalysis and templating of semiconductor synthesis,; and (3) to further investigate, scale up and harness the biologically inspired, low-temperature, kinetically controlled catalytic synthesis method we developed (based on the mechanism we discovered in silicatein) to investigate the kinetic control of the structure-function relationships in magnetic materials, and develop new materials for energy applications. The bio-inspired catalytic synthesis method we have developed is low-cost, low temperature, and operates without the use of polluting chemicals. In addition to direct applications for improvement of batteries and fuel cells, the broader impact of this research includes a deeper fundamental understanding of the factors governing kinetically controlled synthesis and its control of the emergent nanostructure and performance of a wide range of nanomaterials for energy applications.

  10. (abstract) A Mobile Robot for Remote Response to Incidents Involving Hazardous Materials

    NASA Technical Reports Server (NTRS)

    Welch, Richard V.

    1994-01-01

    This paper will report the status of the Emergency Response Robotics project, a teleoperated mobile robot system being developed at JPL for use by the JPL Fire Department/HAZMAT Team. The project, which began in 1991, has been focused on developing a robotic vehicle which can be quickly deployed by HAZMAT Team personnel for first entry into an incident site. The primary goals of the system are to gain access to the site, locate and identify the hazard, and aid in its mitigation. The involvement of JPL Fire Department/HAZMAT Team personnel has been critical in guiding the design and evaluation of the system. A unique feature of the current robot, called HAZBOT III, is its special design for operation in combustible environments. This includes the use of all solid state electronics, brushless motors, and internal pressurization. Demonstration and testing of the system with HAZMAT Team personnel has shown that teleoperated robots, such as HAZBOT III, can successfully gain access to incident sites locating and identifying hazardous material spills. Work is continuing to enable more complex missions through the addition of appropriate sensor technology and enhancement of the operator interface.

  11. (abstract) A Mobile Robot for Remote Response to Incidents Involving Hazardous Materials

    NASA Technical Reports Server (NTRS)

    Welch, Richard V.

    1994-01-01

    This paper will report the status of the Emergency Response Robotics project, a teleoperated mobile robot system being developed at JPL for use by the JPL Fire Department/HAZMAT Team. The project, which began in 1991, has been focused on developing a robotic vehicle which can be quickly deployed by HAZMAT Team personnel for first entry into an incident site. The primary goals of the system are to gain access to the site, locate and identify the hazard, and aid in its mitigation. The involvement of JPL Fire Department/HAZMAT Team personnel has been critical in guiding the design and evaluation of the system. A unique feature of the current robot, called HAZBOT III, is its special design for operation in combustible environments. This includes the use of all solid state electronics, brushless motors, and internal pressurization. Demonstration and testing of the system with HAZMAT Team personnel has shown that teleoperated robots, such as HAZBOT III, can successfully gain access to incident sites locating and identifying hazardous material spills. Work is continuing to enable more complex missions through the addition of appropriate sensor technology and enhancement of the operator interface.

  12. (2+1)-Dimensional manipulation of soft biological materials by opto-thermal diffusiophoresis

    NASA Astrophysics Data System (ADS)

    Maeda, Yusuke T.

    2013-12-01

    In a temperature gradient built by infrared laser heating, polyethylene glycol (PEG) of large concentration moves away from the hot region. The resulting concentration gradient of PEG creates entropic potential well and traps another solute of small concentration due to diffusiophoresis. Here we develop this method to work in two dimensional spaces and time. The steering of laser traps colloids, DNA, and living cells in designed two-dimensional patterns. By modulating laser intensity with time, the protein concentration is periodically controlled in tens of mHz. This method could be useful for a directed assembly of biological materials.

  13. Development and application of photosensitive device systems to studies of biological and organic materials

    SciTech Connect

    Gruner, S.M.; Reynolds, G.T.

    1992-05-15

    This report describes progress as of the third year of a 3-year DoE grant for 1/1/92 to 12/31/92. Because this is the last year of a 3- year grant cycle, this report will summarize progress over the entire 3-year period. The overall goals of the grant are to develop novel instrumentation and techniques for the performance of biological and materials research, and especially for the development of x-ray detectors suitable for use at storage ring sources. Research progress has been excellent and the overall goals, as well as most of the specific goals have been successfully met.

  14. Cognition from the bottom up: on biological inspiration, body morphology, and soft materials.

    PubMed

    Pfeifer, Rolf; Iida, Fumiya; Lungarella, Max

    2014-08-01

    Traditionally, in cognitive science the emphasis is on studying cognition from a computational point of view. Studies in biologically inspired robotics and embodied intelligence, however, provide strong evidence that cognition cannot be analyzed and understood by looking at computational processes alone, but that physical system-environment interaction needs to be taken into account. In this opinion article, we review recent progress in cognitive developmental science and robotics, and expand the notion of embodiment to include soft materials and body morphology in the big picture. We argue that we need to build our understanding of cognition from the bottom up; that is, all the way from how our body is physically constructed.

  15. Modeling low energy x-ray interactions with biological material at the CUEBIT

    NASA Astrophysics Data System (ADS)

    Klingenberger, J.; Schott, M.; Kimmel, T.; Medlin, D.; Gall, A.; Rusin, M.; Dean, D.; Takacs, E.

    2015-01-01

    Recent developments at Clemson University have established the need to model the production of x-rays using a highly charged ion beam generated by the Clemson University Electron Beam Ion Trap (CUEBIT). A Geant4 modeling environment has been developed on Clemson University's Palmetto2 supercomputing cluster to simulate the interaction of these x- rays with biological material. Preliminary results of the model have been obtained after performing initial simulations on the computing cluster. Future experiments using the CUEBIT as well as refinements to the Geant4 model are discussed.

  16. Systematic toxicological analysis: computer-assisted identification of poisons in biological materials.

    PubMed

    Stimpfl, Th; Demuth, W; Varmuza, K; Vycudilik, W

    2003-06-05

    A new software was developed to improve the chances for identification of a "general unknown" in complex biological materials. To achieve this goal, the total ion current chromatogram was simplified by filtering the acquired mass spectra via an automated subtraction procedure, which removed mass spectra originating from the sample matrix, as well as interfering substances from the extraction procedure. It could be shown that this tool emphasizes mass spectra of exceptional compounds, and therefore provides the forensic toxicologist with further evidence-even in cases where mass spectral data of the unknown compound are not available in "standard" spectral libraries.

  17. Particle Accelerator Applications: Ion and Electron Irradiation in Materials Science, Biology and Medicine

    SciTech Connect

    Rodriguez-Fernandez, Luis

    2010-09-10

    Although the developments of particle accelerators are devoted to basic study of matter constituents, since the beginning these machines have been applied with different purposes in many areas also. Today particle accelerators are essential instruments for science and technology. This work presents an overview of the main application for direct particle irradiation with accelerator in material science, biology and medicine. They are used for material synthesis by ion implantation and charged particle irradiation; to make coatings and micromachining; to characterize broad kind of samples by ion beam analysis techniques; as mass spectrometers for atomic isotopes determination. In biomedicine the accelerators are applied for the study of effects by charged particles on cells. In medicine the radiotherapy by electron irradiation is widely used, while hadrontherapy is still under development. Also, they are necessary for short life radioisotopes production required in radiodiagnostic.

  18. Particle Accelerator Applications: Ion and Electron Irradiation in Materials Science, Biology and Medicine

    NASA Astrophysics Data System (ADS)

    Rodríguez-Fernández, Luis

    2010-09-01

    Although the developments of particle accelerators are devoted to basic study of matter constituents, since the beginning these machines have been applied with different purposes in many areas also. Today particle accelerators are essential instruments for science and technology. This work presents an overview of the main application for direct particle irradiation with accelerator in material science, biology and medicine. They are used for material synthesis by ion implantation and charged particle irradiation; to make coatings and micromachining; to characterize broad kind of samples by ion beam analysis techniques; as mass spectrometers for atomic isotopes determination. In biomedicine the accelerators are applied for the study of effects by charged particles on cells. In medicine the radiotherapy by electron irradiation is widely used, while hadrontherapy is still under development. Also, they are necessary for short life radioisotopes production required in radiodiagnostic.

  19. The development and role of international biological reference materials in the diagnosis of anaemia.

    PubMed

    Thorpe, Susan J

    2010-07-01

    Anaemia is a major global health problem. Although the main cause is iron deficiency, anaemia also results from other nutritional deficiencies (folate and vitamin B12), haemolytic disorders including haemoglobinopathies, and bone marrow disorders. Accurate diagnosis of anaemia is dependent on reliable diagnostic tests and reference ranges, which in turn are dependent on effective standardisation. Standardisation is achieved through the availability of reference materials and reference measurement procedures. International biological reference materials have therefore been developed to standardise and control diagnostic tests for anaemia for a diverse range of analytes including total haemoglobin and haemoglobin types, ferritin, the serum transferrin receptor, serum vitamin B12 and folate, whole blood folate, and alloantibodies which mediate immune haemolytic anaemia.

  20. QEEN Workshop: "Quantifying Exposure to Engineered Nano-materials from Manufactured Products": Write Up Biological Tissues and Media

    EPA Science Inventory

    The measurement and characterization of nanomaterials in biological tissues is complicated by a number of factors including: the sensitivity of the assay to small sized particles or low concentrations of materials; the ability to distinguish different forms and transformations of...

  1. QEEN Workshop: "Quantifying Exposure to Engineered Nano-materials from Manufactured Products": Write Up Biological Tissues and Media

    EPA Science Inventory

    The measurement and characterization of nanomaterials in biological tissues is complicated by a number of factors including: the sensitivity of the assay to small sized particles or low concentrations of materials; the ability to distinguish different forms and transformations of...

  2. Problems Involved in the Choice and Use of Materials in Airplane Construction

    NASA Technical Reports Server (NTRS)

    Brenner, Paul

    1932-01-01

    The present state of the problem of materials in airplane construction is studied on the basis of data giving the principal characteristics of different materials and showing how they affect the form of airplane parts.

  3. Organ-targeted high-throughput in vivo biologics screen identifies materials for RNA delivery.

    PubMed

    Chang, Tsung-Yao; Shi, Peng; Steinmeyer, Joseph D; Chatnuntawech, Itthi; Tillberg, Paul; Love, Kevin T; Eimon, Peter M; Anderson, Daniel G; Yanik, Mehmet Fatih

    2014-10-01

    Therapies based on biologics involving delivery of proteins, DNA, and RNA are currently among the most promising approaches. However, although large combinatorial libraries of biologics and delivery vehicles can be readily synthesized, there are currently no means to rapidly characterize them in vivo using animal models. Here, we demonstrate high-throughput in vivo screening of biologics and delivery vehicles by automated delivery into target tissues of small vertebrates with developed organs. Individual zebrafish larvae are automatically oriented and immobilized within hydrogel droplets in an array format using a microfluidic system, and delivery vehicles are automatically microinjected to target organs with high repeatability and precision. We screened a library of lipid-like delivery vehicles for their ability to facilitate the expression of protein-encoding RNAs in the central nervous system. We discovered delivery vehicles that are effective in both larval zebrafish and rats. Our results showed that the in vivo zebrafish model can be significantly more predictive of both false positives and false negatives in mammals than in vitro mammalian cell culture assays. Our screening results also suggest certain structure-activity relationships, which can potentially be applied to design novel delivery vehicles.

  4. Organ-targeted high-throughput in vivo biologics screen identifies materials for RNA delivery

    PubMed Central

    Chang, Tsung-Yao; Shi, Peng; Steinmeyer, Joseph D.; Chatnuntawech, Itthi; Tillberg, Paul; Love, Kevin T.; Eimon, Peter M.; Anderson, Daniel G.; Yanik, Mehmet Fatih

    2014-01-01

    Therapies based on biologics involving delivery of proteins, DNA, and RNA are currently among the most promising approaches. However, although large combinatorial libraries of biologics and delivery vehicles can be readily synthesized, there are currently no means to rapidly characterize them in vivo using animal models. Here, we demonstrate high-throughput in vivo screening of biologics and delivery vehicles by automated delivery into target tissues of small vertebrates with developed organs. Individual zebrafish larvae are automatically oriented and immobilized within hydrogel droplets in an array format using a microfluidic system, and delivery vehicles are automatically microinjected to target organs with nearly perfect repeatability and precision. We screened a library of lipid-like delivery vehicles for their ability to facilitate the expression of protein-encoding RNAs in the central nervous system. We discovered delivery vehicles that are effective in both larval zebrafish and rats. Our results showed that the in vivo zebrafish model can be significantly more predictive of both false positives and false negatives in mammals than in vitro mammalian cell culture assays. Our screening results also suggest certain structure-activity relationship, which can potentially be applied to design novel delivery vehicles. PMID:25184623

  5. New Method for Monitoring the Process of Freeze Drying of Biological Materials.

    PubMed

    Alkeev, Nikolay; Averin, Stanislav; von Gratowski, Svetlana

    2015-12-01

    A capacitive sensor was proposed and tested for the monitoring and control of a freeze drying process of a vaccine against the Newcastle disease of birds. The residual moisture of the vaccine was measured by the thermogravimetric method. The vaccine activity was determined by titration in chicken embryos. It was shown that, at the stages of freezing and primary drying, a capacitive sensor measured the fraction of unfrozen liquid phase in a material and allowed one to control the sublimation stage of drying in an optimal way. This prevented the foaming of the material and shortened the total drying time approximately twice. The control range at the sublimation stage of drying expanded up to -70°C. It was found at the final stage of drying that the signal of a capacitive sensor passed through a maximum value. We supposed that this maximum corresponds to the minimum of intramolecular mobility of biological macromolecules and hence to the optimal residual moisture of the material, which ensures long-term preservation of its activity. We also suppose that using the capacitive sensor at the final stage of drying allows one to more precisely detect the time when the residual moisture of dried material reaches the optimal value.

  6. Development and application of photosensitive device systems to studies of biological and organic materials

    SciTech Connect

    Gruner, S.M.; Reynolds, G.T.

    1991-07-23

    This report describes the progress of the second year of a 3-year DOE grant DE-FG-02-87ER60522 for the fiscal period 1/1/91 to 12/31/91 as of July 1991. The overall goals of the grant are to develop novel instrumentation and techniques for the performance of biological and materials research and to apply the new developments to basic biological and materials research problems. Since the last progress report, dated July 1990, there has been significant progress on most of the originally proposed instrumentation and applications research. The overall research goals proposed for the next year have not changed from those originally listed. A prototype large area CCD x-ray detector was assembled and evaluated at the CHESS synchrotron facility. Fiber optic CCD coupling methods have been developed and are being applied to in-house detector needs. Novel detector control and calibration software was developed and refined. Novel high pressure x-ray diffraction and dilatometric apparatus were designed and built, and are being applied to the study of membrane-lipid phase behavior. A time-resolved x-ray diffraction study of lipid phase transitions was used to demonstrate that conventual calorimetry does not accurately determine the phase transition parameters. The elastic properties of amphiphilic layers were studied both theoretically and experimentally. A re-entrant hexagonal-lamellar-hexagonal lipid phase transition was discovered and studied. Each of these accomplishments are detailed.

  7. Structural investigation of biological material in aqueous environment by means of infrared-ATR spectroscopy.

    PubMed

    Hofer, P; Fringeli, U P

    1979-12-01

    Infrared attenuated total reflection (ATR) spectroscopy may be used to investigate biological material (e.g., membranes, proteins, erythrocytes etc.) under biological conditions provided that adhesion of the sample can be achieved in aqueous environment. Uncharged lipid multilayer model membranes can be attached by hydrophobic interaction when hydrophobic internal reflection plates (e.g., ZnSe, CdTe) are used. However, if an electric field is applied across the membrane, germanium reflection elements would be preferred because of their low electric resistance (approximately 50 omega cm). This material can also be used if cells or proteins are linked chemically to the ATR plate because of the hydrophilic surface which is similar to that of glass and, thus, enables chemical modification by silanization. It has turned out that good adhesion of uncharged and negatively charged model membranes to germanium plates is achieved when they are coated with a monomolecular layer of aminopropylsilane. There is some evidence that erythrocytes remain more stable when adsorbed to a polymerized aminosilane coating (organic silanization) rather than to the corresponding monolayer (aqueous silanization). Negatively charged germanium surfaces have been obtained by succinylation of the aminosilane coating. Furthermore it has been demonstrated that proteins can be bound to the aminosilane coating by means of carbodiimide. Immobilized acetylcholinesterase was still enzymatically active.

  8. A Continued Study of Polymeric Materials for Protection Against Chemical and Biological Contaminants and Halogen Oxidants for Immobilization in Protective Materials and Coatings

    DTIC Science & Technology

    2013-03-01

    laboratory testing of materials developed during the project, as well as to Dr. M. E. Shirtliff at the Center for Biofilm Engineering at Montana State...unlimited. 88ABW-2013-1126, 8 March 2013. Engineering at Montana State University coated polycarbonate slides with our material and tested them...AFRL-RX-TY-TR-2012-0027 A CONTINUED STUDY OF POLYMERIC MATERIALS FOR PROTECTION AGAINST CHEMICAL AND BIOLOGICAL CONTAMINANTS AND HALOGEN

  9. [Evaluation of biological influence of nano-materials using toxicokinetic and toxicoproteomic approach].

    PubMed

    Yoshikawa, Tomoaki; Nabeshi, Hiromi; Yoshioka, Yasuo

    2008-12-01

    The recent development of nanotechnology has facilitated a dramatic reduction in the size of materials. Nanomaterials are nanometer-sized materials with specific physicochemical properties that are different from those of the bulk material of the same composition. Such properties make them very attractive for cosmetic and medical applications. However, nanoparticles can act on living cells or bodies at the nano-level resulting in biologically undesirable as well as desirable effects. Thus, reduction in particle size from the micro- to nano-scale not only provides benefits to diverse scientific fields but also poses potential risks to the environment and to human health. Although significant resources are aimed at exploiting the desirable properties of nanoparticles for applications in medicine or cosmetics there are only limited attempts to evaluate potentially undesirable effects in vivo. Thus, there is a pressing need for a careful consideration of the benefits and side effects to the use of nanoparticles in medicine and cosmetics. In recent years, the majority of toxic biological response induced by nanomaterials (Nanotoxicity) has focused on cell culture systems. However, data from these studies will require verification from in vivo experiments using animals. An understanding of Toxicokinetics (the relationship between the physical properties of the nanomaterials and their in vivo behavior) would provide a basis for evaluating undesirable effects. Moreover, toxicoproteomics may identify predictive bio-markers for examining nanotoxicity. In this review article, we describe the assumptions and challenges in the field of nanotoxicity and describe advances for studying nanotoxicity of nanosilicas using toxicokinetics/toxicoproteomics both in vivo and in vitro.

  10. Evaluation of flow injection analysis for determination of cholinesterase activities in biological material.

    PubMed

    Cabal, Jiri; Bajgar, Jiri; Kassa, Jiri

    2010-09-06

    The method for automatic continual monitoring of acetylcholinesterase (AChE) activity in biological material is described. It is based on flexible system of plastic pipes mixing samples of biological material with reagents for enzyme determination; reaction product penetrates through the semipermeable membrane and it is spectrophotometrically determined (Ellman's method). It consists of sampling (either in vitro or in vivo), adding the substrate and flowing to dialyzer; reaction product (thiocholine) is dialyzed and mixed with 5,5'-dithio-bis-2-nitrobenzoic acid (DTNB) transported to flow spectrophotometer. Flowing of all materials is realised using peristaltic pump. The method was validated: time for optimal hydratation of the cellophane membrane; type of the membrane; type of dialyzer; conditions for optimal permeation of reaction components; optimization of substrate and DTNB concentrations (linear dependence); efficacy of peristaltic pump; calibration of analytes after permeation through the membrane; excluding of the blood permeation through the membrane. Some examples of the evaluation of the effects of AChE inhibitors are described. It was demonstrated very good uniformity of peaks representing the enzyme activity (good reproducibility); time dependence of AChE inhibition caused by VX in vitro in the rat blood allowing to determine the half life of inhibition and thus, bimolecular rate constants of inhibition; reactivation of inhibited AChE by some reactivators, and continual monitoring of the activity in the whole blood in vivo in intact and VX-intoxicated rats. The method is simple and not expensive, allowing automatic determination of AChE activity in discrete or continual samples in vitro or in vivo. It will be evaluated for further research of cholinesterase inhibitors.

  11. The Impact Response of Composite Materials Involved in Helicopter Vulnerability Assessment: Literature Review - Part 1

    DTIC Science & Technology

    2006-04-01

    literature on composite and cellular material impact response. It also outlines current trends in theoretical and experimental studies of material...the Terminal Effects Group of the Weapons Systems Division (DSTO) in 1998. His current research interests include constitutive modelling and material...procedures for an assessment of the capability/vulnerability of air structures. The current report provides a detailed overview of contemporary studies in

  12. Effects of chemical and biological warfare remediation agents on the materials of museum objects

    NASA Astrophysics Data System (ADS)

    Solazzo, C.; Erhardt, D.; Marte, F.; von Endt, D.; Tumosa, C.

    In the fall of 2001, anthrax-contaminated letters were sent to public figures in the United States. Chemical and radiation treatments were employed to decontaminate exposed buildings, objects, and materials. These treatments are effective, but potentially damaging to exposed objects and materials. The recommended surface chemical treatments include solutions, gels, and foams of oxidizing agents such as peroxides or chlorine bleaching agents. Such oxidizing agents are effective against a wide range of hazardous chemical and biological agents. Knowing how these reagents affect various substrates would help to anticipate and to minimize any potential damage. We are examining the effects on typical museum materials of reagents likely to be used, including hydrogen peroxide, sodium hypochlorite, and potassium peroxymonosulfate. Results so far show significant changes in a number of materials. Surface corrosion was observed on metals such as copper, silver, iron, and brass. Color changes occurred with at least one reagent in about one-fourth of the dyed fabric swatches tested, and about half of the inks. Samples of aged yellowed paper are bleached. Effects varied with both the substrate and the tested reagent. The observed changes were generally less drastic than might have been expected. Enough materials were affected, though, to preclude the use of these reagents on museum objects unless no less drastic alternative is available. It appears that many objects of lesser intrinsic value can be treated without severe loss of properties or usefulness. For example, most documents should remain legible if the appropriate reagent is used. This work will provide a basis for determining which treatment is most appropriate for a specific situation and what consequences are to be expected from other treatments.

  13. A systematic study of the release of bisphenol A by orthodontic materials and its biological effects.

    PubMed

    Halimi, Abdelali; Benyahia, Hicham; Bahije, Loubna; Adli, Hanane; Azeroual, Mohamed-Faouzi; Zaoui, Fatima

    2016-12-01

    Bisphenol A (BPA) is a synthetic chemical substance used as a starting ingredient in the manufacturing process of a number or orthodontic materials. It is a well-known endocrine disruptor with low estrogenic properties. The aim of this investigation is to present a systematic review regarding the issue of bisphenol A release by orthodontic materials and its impact in orthodontics. A systematic analysis was performed by electronic search (between 1936 and 2015) on several data bases. The search was limited by using several specific key-words in two languages, English and French. Two investigators selected the responses, which met the selection criteria. Of the 376 studies found, only 21 met our selection criteria: 11 of these dealt with the release of bisphenol by orthodontic materials and 10 in vitro studies described the effects of BPA leaching from orthodontic materials on human and murine cells. The rate of BPA release was well below the daily tolerable intake (DTI) (50mg/kg/day in 2006, then 50μg/kg/day in 2015) according to the European Food Safety Authority (EFSA). Theoretical exposure to BPA was 11,000 times lower than recommendations. However, other studies have shown the presence of BPA and of monomers released in large quantities at very low doses. The effects of observed BPA varied significantly (toxic and carcinogenic potential) while some studies found no effects at all. The relatively small number of studies dealing with the release of Bisphenol A by orthodontic materials, apart from orthodontic materials and their significant biological effects, has led to the absence of standard protocols and has hindered precise determination of released BPA. Moreover, the lack of coherence between the various methodological approaches and variations in the experimental protocols have resulted in a low level of proof regarding the impact of BPA by orthodontic materials. Through this study, the authors encourage clinicians to observe the following recommendations

  14. Biological material detection identification and monitoring: combining point and standoff sensors technologies

    NASA Astrophysics Data System (ADS)

    Buteau, Sylvie; Rowsell, Susan

    2016-10-01

    Detection, Identification and Monitoring (DIM) of biological material is critical to enhancing Situational Awareness (SA) in a timely manner, supporting decisions, and enabling the endangered force to take the most appropriate actions in a recognized CB environment. An optimum Bio DIM capability would include both point sensors to provide local monitoring and sampling for confirmatory ID of the material, and standoff sensors to provide wide-area monitoring from a distance, increasing available response time and enhancing SA. In June 2015, a Canadian team co-deployed a point (VPBio) and a standoff (BioSense) bio sensor during the international S/K Challenge II event, at Dugway Proving Ground (DPG), USA. The co-deployment of the point and standoff sensors allowed the assessment of their respective strengths and limitations with regards to Bio DIM and SA in a realistic CB environment. Moreover, the initial hypothesis stating the existence of valuable leverages between the two sensors in a context of Bio DIM was confirmed. Indeed, the spatial limitation of the point sensor was overcome with the wide area coverage of the standoff technology. In contrast, the sampling capability of the point sensor can allow confirmatory identification of the detected material. Additionally, in most scenarios, the combined results allowed an increase in detection confidence. In conclusion, the demonstration of valuable leverages between point and standoff sensors in a context of Bio DIM was made, confirming the mitigation effect of co-deploying these systems for bio surveillance.

  15. MCM-enzyme-supramolecular hydrogel hybrid as a fluorescence sensing material for polyanions of biological significance.

    PubMed

    Wada, Atsuhiko; Tamaru, Shun-ichi; Ikeda, Masato; Hamachi, Itaru

    2009-04-15

    Polyanions are important sensing targets because of their wide variety of biological activities. We report a novel polyanion-selective fluorescence sensing system composed of a hybrid material of supramolecular hydrogel, enzymes, and aminoethyl-modified MCM41-type mesoporous silica particles (NH(2)-MCM41) encapsulating anionic fluorescent dyes. The rational combination of the polyanion-exchange ability of NH(2)-MCM41 and semi-wet supramolecular hydrogel matrix successfully produced three distinct domains; namely, cationic nanopores, hydrophobic nano/microfibers, and aqueous bulk gel phase, which are orthogonal to each other. The coupling of anion-selective probe release from NH(2)-MCM41 with translocation of the probe facilitated by enzymatic reaction enabled fluorescence resonance energy transfer-type sensing in the hybrid materials for polyanions such as heparin, chondroitin sulfate, sucrose octasulfate, and so forth. The enzymatic dephosphorylation catalyzed by phosphatase (alkaline phosphatase or acid phosphatase) that is embedded in gel matrix with retention of activity also contributed to improving the sensing selectivity toward polysulfates relative to polyphosphates. It is clear that the orthogonal domain formation of these materials and maintaining the mobility of the fluorescent dyes between the three domains are crucial for the rapid and convenient sensing provided by this system.

  16. Specifications and Other Standardization Documents Involving Cellular Plastics (Plastic Foams), Cushioning and Related Materials

    DTIC Science & Technology

    1976-07-01

    FOR MEDICAL MATERIAL REQUIRING CONTROLLED TEMPERATURE RANGES 258 PPP-C-1683(1) 8135 69 10 Oct 73 CUSHIONING MATERIAL, EXPANDED POLYSTYRENE LOOSE FILL...Liquid immersion effect on properties of elastoaeric vulcanizates - 45 Lead deflection characteristics - 264 Loose-fill expanded polystyrene - 25f

  17. Involving All Families: An Annotated Bibliography of Materials for Families Available in Languages Other than English.

    ERIC Educational Resources Information Center

    Davis, Diane Talley, Ed.; And Others

    This bibliography resulted from an investigation into the process and feasibility of developing an annotated bibliography of educational materials available in languages other than English. Materials were obtained from California, Illinois, Maine, Maryland, Massachusetts, Minnesota, New Mexico, Ohio, and the District of Columbia. Forty-two…

  18. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.

    PubMed

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N; Fang, Zhiqiang; Zhu, J Y; Henriksson, Gunnar; Himmel, Michael E; Hu, Liangbing

    2016-08-24

    goal of this study is to review the fundamental structures and chemistries of wood and wood-derived materials, which are essential for a wide range of existing and new enabling technologies. The scope of the review covers multiscale materials and assemblies of cellulose, hemicellulose, and lignin as well as other biomaterials derived from wood, in regard to their major emerging applications. Structure-properties-application relationships will be investigated in detail. Understanding the fundamental properties of these structures is crucial for designing and manufacturing products for emerging applications. Today, a more holistic understanding of the interplay between the structure, chemistry, and performance of wood and wood-derived materials is advancing historical applications of these materials. This new level of understanding also enables a myriad of new and exciting applications, which motivate this review. There are excellent reviews already on the classical topic of woody materials, and some recent reviews also cover new understanding of these materials as well as potential applications. This review will focus on the uniqueness of woody materials for three critical applications: green electronics, biological devices, and energy storage and bioenergy.

  19. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications

    SciTech Connect

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N.; Fang, Zhiqiang; Zhu, J. Y.; Henriksson, Gunnar; Himmel, Michael E.; Hu, Liangbing

    2016-08-24

    goal of this study is to review the fundamental structures and chemistries of wood and wood-derived materials, which are essential for a wide range of existing and new enabling technologies. The scope of the review covers multiscale materials and assemblies of cellulose, hemicellulose, and lignin as well as other biomaterials derived from wood, in regard to their major emerging applications. Structure-properties-application relationships will be investigated in detail. Understanding the fundamental properties of these structures is crucial for designing and manufacturing products for emerging applications. Today, a more holistic understanding of the interplay between the structure, chemistry, and performance of wood and wood-derived materials is advancing historical applications of these materials. This new level of understanding also enables a myriad of new and exciting applications, which motivate this review. There are excellent reviews already on the classical topic of woody materials, and some recent reviews also cover new understanding of these materials as well as potential applications. This review will focus on the uniqueness of woody materials for three critical applications: green electronics, biological devices, and energy storage and bioenergy.

  20. Biological and structural characterization of a naturally inspired material engineered from elastin as a candidate for tissue engineering applications.

    PubMed

    Vassalli, Massimo; Sbrana, Francesca; Laurita, Alessandro; Papi, Massimiliano; Bloise, Nora; Visai, Livia; Bochicchio, Brigida

    2013-12-23

    The adoption of a biomimetic approach in the design and fabrication of innovative materials for biomedical applications is encountering a growing interest. In particular, new molecules are being engineered on the basis of proteins present in the extracellular matrix, such as fibronectin, collagen, or elastin. Following this approach scientists expect to be able not only to obtain materials with tailored mechanical properties but also to elicit specific biological responses inherited by the mimicked tissue. In the present work, a novel peptide, engineered starting from the sequence encoded by exon 28 of human tropoelastin, was characterized from a chemical, physical, and biological point of view. The obtained molecule was observed to aggregate at high temperatures, forming a material able to induce a biological effect similar to what elastin does in the physiological context. This material seems to be a good candidate to play a relevant role in future biomedical applications with special reference to vascular surgery.

  1. [Modeling and experimental study on frequency-domain electricity properties of biological materials].

    PubMed

    Tian, Hua; Luo, Shiqiang; Zhang, Rui; Yang, Gang; Huang, Hua

    2009-12-01

    Frequency-domain electricity properties of four objects, including bullfrog skin, bullfrog muscle, triply distilled water and 0.9% NaCl, were tested in the range of 100Hz-10MHz using home-made electrode and measuring system. The experimental results showed that the resistance of 0.9% NaCl decreased dramatically, that the amplitude frequency characteristics of bullfrog's muscle and skin were similar, but that of triply distilled water did not change significantly. The frequency dependence of 0.9% NaCl showed that the electrode had great influence on the measuring system, so a new equivalent circuit model based on the electrode system was needed. These findings suggest that the new five-parameter equivalent circuit model, which embodies considerations on the interaction between electrodes and tissues, is a reasonable equivalent circuit for studying the electrical characteristics of biological materials.

  2. A controlled rate freeze/thaw system for cryopreservation of biological materials

    NASA Technical Reports Server (NTRS)

    Anselmo, V. J.; Harrison, R. G.

    1979-01-01

    A system which allows programmable temperature-time control for a 5 cc sample volume of an arbitrary biological material was constructed. Steady state and dynamic temperature control was obtained by supplying heat to the sample volume through resistive elements constructed as an integral part of the sample container. For cooling purposes, this container was totally immersed into a cold heat sink. Sample volume thermodynamic property data were obtained by measurements of heater power and heat flux through the container walls. Using a mixture of dry ice and alcohol at -79 C, sample volume was controlled from +40 C to -60 C at rates from steady state to + or - 65 C/min. Steady state temperature precision was better than 0.2 C while the dynamic capability depends on the temperature rate of change as well as the thermal mass of the sample and the container.

  3. Chromium(III) sorption enhancement through NTA - modification of biological materials

    SciTech Connect

    Low, K.S.; Lee, C.K.; Lee, P.L.

    1997-03-01

    The use of low-cost biological materials for the removal and recovery of heavy metals from solution has been investigated extensively in recent times. To enhance their sorption capacities various chemical modifications on the sorbents were attempted. Freer et al. showed that bark from the Pinus radiata (D. Don) had a greater sorption capacity for metals after treatment with both inorganic acid and formaldehyde. Apple wastes treated with phosphorus oxychloride improved the efficiency of removing metal ions. Ethylenediamine tetraacetic acid (EDTA)-modified groundnut, Arachis hypogea, was reported to improve the sorption of cadmium and lead ions. Modifications with the aid of dyes also enhanced metal sorption. Moss and coconut husk (CH) are readily obtainable in Malaysia. Their sorption potential for metals has been reported. This paper reports on the metal sorption enhancement of these two biosorbents after chemical modification with nitrilotriacetic acid (NTA). 13 refs., 5 figs., 2 tabs.

  4. [Application of biologically active suture materials in emergency surgery of abdominal cavity organs].

    PubMed

    Mokhov, E M; Chumakov, R Iu; Sergeev, A N

    2012-01-01

    An investigation of specific course of the wound process and near results of operations on 398 patients with emergency abdominal surgical pathology has revealed advantages of using new biologically active suture materials "Nikant" (with doxicyclin) and "Nikant-P" (with doxicyclin and stimulator of regeneration from the group of hermanium-containing organic compounds) in performing surgical interventions. Total number of patients with complications at the early postoperative period, operated using threads "Nikant" (38-29.9%) and "Nikant-P" (30-23.8%) proved to be reliably less than in patients of the control group (71-48.9%). The results of operations improved at the expense of considerable reduction of the number of postoperative local pyo-inflammatory processes.

  5. [BIOLOGICAL PROPERTIES OF SALMONELLA, ISOLATED FROM CLINICAL MATERIAL AND AQUATIC ENVIRONMENT IN ROSTOV REGION].

    PubMed

    Panasovets, O P; Usatkin, A V; Shmailenko, O A

    2015-01-01

    Study biological properties of salmonella, isolated from clinical materials and water of Don river. Salmonella strains of various serovars were used in the study. Biochemical characteristics were studied by generally accepted methods, antigenic properties were evaluated in agglutination reactions, virulence was determined by Dlm for laboratory animals, antibiotics sensitivity was verified by disc-diffusion method. The presence of pathogenicity factors in isolated strains was shown: hemolytic activity--in 64 and 36.8% of cases, DNAse activity--in 28 and 26%, respectively in clinical and wild strains. Microorganism dose, resulting in death of all the animals (LD100) did not depend on serovar of salmonella and varied from 10(3) to 10(10) PFU/ml. Clinical strains were established to possess higher virulence and resistance to antibiotics compared with strains isolated from the aquatic envionment.

  6. Optical diffraction and spatial filtering of electron micrographs of biological materials

    SciTech Connect

    Wever, G.H.; Dunn, P.; Wiberg, J.S.; Thompson, B.J.

    1980-01-01

    Optical diffraction and spatial filtering methods have been used to determine the characteristics of periodic structures in many biological materials. The head shell of bacteriophage T4 was chosen for this study, since aberrations in the assembly of the shell due to mutation or changes in growth conditions lead to the formation of a variety of elongated tubular head forms. The lattice parameters of structures assembled at elevated growth temperatures by normal, wild-type T4 and by a mutant (regA) were analyzed using optical diffraction patterns obtained from electron micrographs. Spatial filtering procedures were used for the reconstruction of one-sided images to determine the characteristics of the head structures assembled under different growth conditions.

  7. Cancer patients' attitudes toward future research uses of stored human biological materials.

    PubMed

    Helft, Paul R; Champion, Victoria L; Eckles, Rachael; Johnson, Cynthia S; Meslin, Eric M

    2007-09-01

    THE POLICY DEBATE CONCERNING INFORMED consent for future, unspecified research of stored human biological materials (HBM) would benefit from an understanding of the attitudes of individuals who contribute tissue specimens to HBM repositories. Cancer patients who contributed leftover tissue to the Indiana University Cancer Center Tissue Bank under such conditions were recruited for a mail survey study of their attitudes. Our findings suggest that a clear majority of subjects would permit unlimited future research on stored HBMs without re-contact and reconsent, and a significant minority appear to desire ongoing control over future research uses of their tissue. These differences merit further investigation and suggest that a policy of blanket consent for all future, unspecified research would be premature.

  8. Same-day batch measurement of glycine betaine, carnitine, and other betaines in biological material.

    PubMed

    Lever, M; Bason, L; Leaver, C; Hayman, C M; Chambers, S T

    1992-08-15

    Glycine betaine, carnitine, carnitine esters, butyrobetaine, and proline betaine (stachydrine) concentrations in biological materials can be reliably measured in 100-microliters samples, with a detection limit below 1 mumol/liter. The procedure is suitable for batches of more than 30 specimens and it is possible to obtain a single result within 2 h. The betaines are extracted into an acetonitrile:methanol mixture, dried with anhydrous disodium hydrogen phosphate containing argentous oxide. The 4-bromophenacyl ester derivatives are formed using 4-bromophenacyl triflate as reagent, in the presence of solid magnesium oxide as base. The derivatives are separated by high-performance chromatography on a silica column, in a mixed partition and ion-exchange mode.

  9. Why should we respect the privacy of donors of biological material?

    PubMed

    Tännsjö, Torbjörn

    2011-02-01

    Why should we respect the privacy of donors of biological material? The question is answered in the present article in general philosophical terms from the point of view of an ethics of honour, a libertarian theory of rights, a view of respect for privacy based on the idea that autonomy is of value in itself, and utilitarianism respectively. For different reasons the ethics of honour and the idea of the value of autonomy are set to one side. It surfaces that the moral rights theory and utilitarianism present conflicting answers to the question. The main thrust of the argument is that there is no way of finding an overlapping consensus, so politicians have to take decisions that are bound to be controversial in that they can be questioned on reasonable philosophical grounds.

  10. Ferromagnetic resonance for the quantification of superparamagnetic iron oxide nanoparticles in biological materials

    PubMed Central

    Gamarra, Lionel F; daCosta-Filho, Antonio J; Mamani, Javier B; de Cassia Ruiz, Rita; Pavon, Lorena F; Sibov, Tatiana T; Vieira, Ernanni D; Silva, André C; Pontuschka, Walter M; Amaro, Edson

    2010-01-01

    The aim of the present work is the presentation of a quantification methodology for the control of the amount of superparamagnetic iron oxide nanoparticles (SPIONs) administered in biological materials by means of the ferromagnetic resonance technique (FMR) applied to studies both in vivo and in vitro. The in vivo study consisted in the analysis of the elimination and biodistribution kinetics of SPIONs after intravenous administration in Wistar rats. The results were corroborated by X-ray fluorescence. For the in vitro study, a quantitative analysis of the concentration of SPIONs bound to the specific AC133 monoclonal antibodies was carried out in order to detect the expression of the antigenic epitopes (CD133) in stem cells from human umbilical cord blood. In both studies FMR has proven to be an efficient technique for the SPIONs quantification per volume unit (in vivo) or per labeled cell (in vitro). PMID:20463936

  11. Biological evaluation of a new pulp capping material developed from Portland cement.

    PubMed

    Negm, Ahmed M; Hassanien, Ehab E; Abu-Seida, Ashraf M; Nagy, Mohamed M

    2017-03-02

    This study evaluates the biological properties of a new pulp capping material developed from Portland cement. This study was conducted on 48 teeth in 4 dogs (12 teeth/dog). The dogs were classified into two equal groups (n=24 teeth) according to the evaluation period including: group A (3 weeks) and group B (3 months). Each group was further subdivided into three equal subgroups (n=8 teeth) according to the capping material including: subgroup 1: mineral trioxide aggregate (MTA), subgroup2: Portland cement+10% calcium hydroxide+20% bismuth oxide (Port Cal) and subgroup 3: Portland cement+bismuth oxide. After general anesthesia, a class V buccal cavity was prepared coronal to the gingival margin. After pulp exposure and hemostasis,the capping materials and glass ionomer filling were placed on the exposure sites. All histopathological findings, inflammatory cell count and dentin bridge formation were recorded. Data were analyzed statistically. After 3 months, the histopathological picture of the pulp in subgroup 1 showed normal pulp, continuous odontoblastic layer and complete dentin bridge formation while subgroup 2 showed partial and complete dentin bridge over a normal and necrotic pulps. Subgroup 3 showed loss of normal architecture, areas of necrosis, complete, or incomplete dentin bridge formation, attached and detached pulp stones and fatty degeneration in group B. For group A, MTA subgroup showed the least number of inflammatory cell infiltrate followed by Port Cal subgroup. While subgroup 3 showed the highest number of inflammatory cell infiltrate. For group B, the mean inflammatory cell count increased with the three tested materials with no statistical difference. Regarding dentin bridge formation at group A, no significant differences was found between subgroups, while at group B, MTA subgroup exhibited significantly higher scores than other subgroups. In conclusion, addition of calcium hydroxide to Portland cement improves the dentin bridge formation

  12. Chemical imaging of biological materials by NanoSIMS using isotopic and elemental labels

    SciTech Connect

    Weber, P K; Fallon, S J; Pett-Ridge, J; Ghosal, S; Hutcheon, I D

    2006-04-10

    The NanoSIMS 50 combines unprecedented spatial resolution (as good as 50 nm) with ultra-high sensitivity (minimum detection limit of {approx}200 atoms). The NanoSIMS 50 incorporates an array of detectors, enabling simultaneous collection of 5 species originating from the same sputtered volume of a sample. The primary ion beam (Cs{sup +} or O{sup -}) can be scanned across the sample to produce quantitative secondary ion images. This capability for multiple isotope imaging with high spatial resolution provides a novel new approach to the study of biological materials. Studies can be made of sub-regions of tissues, mammalian cells, and bacteria. Major, minor and trace element distributions can be mapped on a submicron scale, growth and metabolism can be tracked using stable isotope labels, and biogenic origin can be determined based on composition. We have applied this technique extensively to mammalian and prokaryotic cells and bacterial spores. The NanoSIMS technology enables the researcher to interrogate the fate of molecules of interest within cells and organs through elemental and isotopic labeling. Biological applications at LLNL will be discussed.

  13. Damage-free vibrational spectroscopy of biological materials in the electron microscope

    DOE PAGES

    Rez, Peter; Aoki, Toshihiro; March, Katia; ...

    2016-03-10

    Vibrational spectroscopy in the electron microscope would be transformative in the study of biological samples, provided that radiation damage could be prevented. However, electron beams typically create high-energy excitations that severely accelerate sample degradation. Here this major difficulty is overcome using an ‘aloof’ electron beam, positioned tens of nanometres away from the sample: high-energy excitations are suppressed, while vibrational modes of energies o1 eV can be ‘safely’ investigated. To demonstrate the potential of aloof spectroscopy, we record electron energy loss spectra from biogenic guanine crystals in their native state, resolving their characteristic C–H, N–H and C=O vibrational signatures with nomore » observable radiation damage. Furthermore, the technique opens up the possibility of non-damaging compositional analyses of organic functional groups, including non-crystalline biological materials, at a spatial resolution of ~10nm, simultaneously combined with imaging in the electron microscope.« less

  14. Collection of biological materials in biodiversity prospecting in India: problems and solutions.

    PubMed

    Mehrotra, B N

    1996-04-01

    Forests are the chief resource for the collection and exploration of biological materials. The past few decades have witnessed a large scale deforestation in India due to substantial pressures generated by population growth, leading to demand for more land for agriculture, urbanization and industrial activities, in addition to increased demand for fuel wood and timber. This has resulted in the loss of soil cover, habitat destruction, environmental degradation and ecological imbalance. This scenario has created a progressive awareness for the conservation and restoration of habitats and, thus, the declaration of many forest areas into protected zones, such as national parks, biosphere reserves, etc., including the protection of some marine areas, by both the National and State Governments. Normally, permission for biological collecting is not granted in these protected areas. In India, forests are a State subject and grant for collection permission is vested with the State Forest Departments. In the absence of any rules, regulations and guidelines, either from National or State Governments, forest authorities impose their terms and conditions, which are arbitrary and even contradictory at times, in the process of granting collecting permits. A set of new rules to be applied throughout the country is needed.

  15. Interaction of Materials and Biology in Total Joint Replacement – Successes, Challenges and Future Directions

    PubMed Central

    Sato, T; Yao, Z; Goodman, SB

    2014-01-01

    Total joint replacement (TJR) has revolutionized the treatment of end-stage arthritic disorders. This success is due, in large part, to a clear understanding of the important interaction between the artificial implant and the biology of the host. All surgical procedures in which implants are placed in the body evoke an initial inflammatory reaction, which generally subsides over several weeks. Thereafter, a series of homeostatic events occur leading to progressive integration of the implant within bone and the surrounding musculoskeletal tissues. The eventual outcome of the operation is dependent on the characteristics of the implant, the precision of the surgical technique and operative environment, and the biological milieu of the host. If these factors and events are not optimal, adverse events can occur such as the development of chronic inflammation, progressive bone loss due to increased production of degradation products from the implant (periprosthetic osteolysis), implant loosening or infection. These complications can lead to chronic pain and poor function of the joint reconstruction, and may necessitate revision surgery or removal of the prosthesis entirely. Recent advances in engineering, materials science, and the immunological aspects associated with orthopaedic implants have fostered intense research with the hope that joint replacements will last a lifetime, and facilitate pain-free, normal function. PMID:25541591

  16. Evaluation of analytical methods for fluorine in biological and related materials.

    PubMed

    Venkateswarlu, P

    1990-02-01

    During the past two decades, some major pitfalls in fluorine analysis have been recognized and overcome. Therefore, it is important that facts be separated from fallacies in published literature on levels and forms of fluorine (ionic, bound, covalent, etc.) in biological materials, in order that correct perceptions of physiological, biochemical, and toxicological aspects of inorganic as well as organic fluorine compounds can be formed. Trace amounts of inorganic fluoride in biological samples can now be accurately determined with the fluoride electrode either directly or following diffusion, adsorption, or reverse extraction of fluoride (when necessary). The aluminum monofluoride molecular absorption technique provides an excellent rapid method for determination of trace amounts of inorganic fluoride (in the absence of organic fluorine). Fluorine in most organic fluorine compounds is not available for distillation, diffusion, or reverse-extraction. The sample needs to be ashed (open ashing) or combusted (oxygen flask, oxygen bomb, pyrohydrolysis) for covalently bound fluorine to be converted to fluoride ions. This can now be readily accomplished at room temperature by the reductive cleavage of the C-F bond with the sodium biphenyl reagent. Some recommendations for future research have been made.

  17. Graphene-based platform for nano-scale infrared near-field spectroscopy of biological materials

    NASA Astrophysics Data System (ADS)

    Khatib, Omar; Wood, Joshua D.; Doidge, Gregory P.; Damhorst, Gregory L.; Rangarajan, Aniruddh; Bashir, Rashid; Pop, Eric; Lyding, Joseph W.; Basov, Dimitri N.

    2014-03-01

    In biological and life sciences, Fourier Transform Infrared (FTIR) spectroscopy serves as a noninvasive probe of vibrational fingerprints used to identify chemical and molecular species. Near-field spectroscopy, based on the illumination of an atomic force microscope (AFM) tip with an infrared laser, allows for determination of IR properties of a material at nanometer length scales. However, application of near-field IR spectroscopy to most biological systems has thus far been elusive. Physiological conditions required for experimentation are incompatible with typical implementations of nano-FTIR. Recently it became possible to trap water and small biomolecules underneath large-area graphene sheets grown by chemical vapor deposition (CVD). The graphene layer serves as an IR-transparent cover that allows for a near-field interrogation of the underlying layers. We present near-field nano-imaging and spectroscopy data of unencapsulated Tobacco Mosaic Viruses (TMV), compared to those sandwiched between two large-area graphene sheets, and discuss the applicability of near-field IR spectroscopy to trapped biomolecules in aqueous environments.

  18. Targeting the finite-deformation response of wavy biological tissues with bio-inspired material architectures.

    PubMed

    Tu, Wenqiong; Pindera, Marek-Jerzy

    2013-12-01

    The Particle Swarm Optimization algorithm driven by a homogenized-based model is employed to target the response of three types of heart-valve chordae tendineae with different stiffening characteristics due to different degrees of waviness of collagen fibril/fiber bundles. First, geometric and material parameters are identified through an extensive parametric study that produce excellent agreement of the simulated response based on simplified unit cell architectures with the actual response of the complex biological tissue. These include amplitude and wavelength of the crimped chordae microstructure, elastic moduli of the constituent phases, and degree of microstructural refinement of the stiff phase at fixed volume fraction whose role in the stiffening response is elucidated. The study also reveals potential non-uniqueness of bio-inspired wavy microstructures in attaining the targeted response of certain chordae tendineae crimp configurations. The homogenization-based Particle Swarm Optimization algorithm, whose predictions are validated through the parametric study, is then shown to be an excellent tool in identifying optimal unit cell architectures in the design space that exhibits very steep gradients. Finally, defect criticality of optimal unit cell architectures is investigated in order to assess their feasibility in replacing actual biological tendons with stiffening characteristics.

  19. Cultivation of human liver cell lines with microcarriers acting as biological materials of bioartificial liver

    PubMed Central

    Gao, Yi; Xu, Xiao-Ping; Hu, Huan-Zhang; Yang, Ji-Zhen

    1999-01-01

    AIM: To improve the cultivation efficiency and yield of human liver cell line Cl-1. METHODS: High-density cultivation of Cl-1 on microcarriers was carried out with periodic observation of their growth and proliferation. The specific functions of human liver cell were also determined. RESULTS: Cells of Cl-1 cell line grew well on microcarrier Cytodex-3 and on the 7th day the peak was reached. The amount of Cl-1 cells was 2.13 × 108 and the total amount of albumin synthesis reached 71.23 μg, urea synthesis 23.32 mg and diazepam transformation 619.7 μg respectively. The yield of Cl-1 on microcarriers was 49.3 times that of conventional cultivation. The amounts of albumin synthesis, urea synthesis and diazepam transformation were 39.8 times, 41.6 times and 33.3 times those of conventional cultivation, respectively. CONCLUSION: The human liver cell line Cl-1 can be cultivated to a high density with Cytodex-3 and has better biological functions. High-density cultivation of Cl-1 on microcarriers can act as the biological material of bioartificial liver. PMID:11819434

  20. Copper determination in biological materials by ETAAS using W-Rh permanent modifier.

    PubMed

    Lima, Eder C; Barbosa, Fernando; Krug, Francisco J; Tavares, Aline

    2002-04-22

    A tungsten-rhodium treatment on the integrated platform of a transversely heated graphite atomiser was used as a permanent chemical modifier for the determination of copper in biological materials by using digested samples as well as slurry sampling in electrothermal atomic absorption spectrometry. The W-Rh permanent modifier was as efficient as Pd+Mg(NO(3))(2) conventional modifier for obtaining good Cu thermal stabilisation in the digested and slurry samples. The permanent W-Rh modifier remained stable by approximately 300 and 250 firings when 20 mul of digested sample and 20 mul of slurry were delivered into the atomiser, respectively. In addition, the permanent modifier increased the tube lifetime up to 1370 and 744 analytical measurements in the digested and slurry samples, respectively. Also, when the W-Rh permanent modifier was employed, there was less variation of the slope of the analytical curves during the total atomiser lifetime, resulting in a decreased need of re-calibration during routine analysis, increasing the sample throughput, and consequently diminishing the variable analytical costs. Detection limits obtained with W-Rh permanent modifier were 0.64 and 0.33 mug g(-1) Cu for digested (dilution factor 100 ml g(-1)) and 1.0% m/v slurries of biological materials, respectively. Results for the determination of copper in the samples were in agreement with those obtained with decomposed sample solutions by using Pd+Mg(NO(3)), since no statistical differences were found after applying the paired t-test at the 95% level.

  1. Investigation and analysis of asbestos fibers and accompanying minerals in biological materials.

    PubMed

    Le Bouffant, L

    1974-12-01

    A method is described for isolating asbestos fibers contained in biological tissues. It consists in incinerating the biological material in activated oxygen at 150 degrees C, and attacking the ash by 1N HC1 for 18 hr. The residue is then filtered on a membrane covered with a carbon film. Electron microscope examination of the deposit makes it possible to determine fiber concentrations when the weight or volume of primary material is known, and to make size analyses. By x-ray diffraction, the mineralogical nature of the asbestos is determined by comparison with an aluminum reference diagram. For x-ray diffraction, a micromethod is used, with an ash sample of about 10 mug. These techniques are used for identifying and counting asbestos fibers in small fragments of lungs or other organs. It was found that asbestos fibers generally go along with other minerals which may be abundant. Most fibers found in lung are less than 5 mum long. Counts on lungs of asbestos workers give concentrations often greater than 10(7) particles per gram of dry tissue. The evolution of inhaled chrysotile seems to be different from that of amphiboles. In the case of pleural mesothelioma, a comparison of fibers within the tumor with fibers in the adjacent parenchyma shows only slight differences in the particle sizes, but marked differences in their nature, with a chrysotile enrichment in the pleural zone. Pleural plaques were analyzed in the same way. After decalcification, many small sized asbestos fibers were found. The same technique is now being used for determining ingested particles. A great number of observations concerning fiber counts, their nature and sizes, and the presence of various clays minerals will be necessary to establish the role of the different factors in the formation of lesions caused by the inhalation or the ingestion of asbestos fibers.

  2. Technique sensitivity: biological factors contributing to clinical success with various restorative materials.

    PubMed

    Cox, C F; Tarim, B; Kopel, H; Gürel, G; Hafez, A

    2001-08-01

    Since the 1950s, clinicians have relied on various formulations of Ca(OH)2 to stimulate dentin bridge formation. Various studies (Kozlov and Massler, 1966; Massler, 1967; Brännström, 1978; Cox et al., 1987; Snuggs et al., 1993) have demonstrated that pulp healing and dentin bridging can occur against a pH spectrum of materials. Recent studies (Akimoto et al., 1998; Cox et al., 1998, 1999; Tarim et al., 1998; Kitasako et al., 1999; Hafez et al., 2000) have reported successful pulp healing and dentin bridging using adhesives for direct capping of exposed pulps. However, others (Costa et al., 1997; Stanley and Pameijer, 1997; Pameijer, 1998; Hebling et al., 1999; Carvalho et al., 2000) have reported unsatisfactory results when exposures were direct-capped with adhesives. Biological and technical factors, or a combination of both, might be postulated to explain these differences. Recent studies have demonstrated that biological success is dependent upon proper hemorrhage control at the exposure site. This review explores the differences and common factors influencing successful dentin bridging, focusing on data derived from animal studies conducted according to ISO usage guidelines for cavity preparation and material placement. In the past, there has been concern that etching of vital dentin leads to immediate pulp death due to low pH. Recent studies have reported that acidic cements cause breakdown of only the smear layer and fail to seal the restoration interface, leading to inflammation and necrosis. A properly hybridized dentinadhesive interface provides a "bacteriometic" seal to both dentin and pulp tissues. Recent ISO usage studies have shown a high incidence of dentin bridging with adhesives following proper hemorrhage control and removal of both operative debris and biofilm at the dentin-pulp interface by agents such as NaOCl. These are important technique-sensitivity factors to be considered for pulp healing and dentin bridge formation.

  3. Terror Australis 2004: preparedness of Australian hospitals for disasters and incidents involving chemical, biological and radiological agents.

    PubMed

    Edwards, Nicholas A; Caldicott, David G E; Aitken, Peter; Lee, Christine C; Eliseo, Tony

    2008-06-01

    To assess the level of preparedness of Australian hospitals, as perceived by senior emergency department physicians, for chemical, biological and radiological (CBR) incidents, as well as the resources and training available to their departments. Detailed questionnaires were mailed to the directors of the 86 hospital emergency departments (EDs) in Australia accredited by the Australasian College for Emergency Medicine. Questions covered hospital planning, available resources and training, and perceived preparedness. Responses were received from 76 departments (88%): 73 reported that their ED had a disaster plan, with 60 (79%) having a contingency plan for chemical, 57 (75%) for biological, and 53 (70%) for radiological incidents. Specific staff training for managing patients from a conventional mass casualty incident was given in 83% of EDs, falling to 66% for a CBR incident. Forty-three per cent reported that their plan involved staff managing contaminated patients, but availability of personal protective equipment and decontamination facilities varied widely. Although 41% believed their ED could cope with a maximum of 20 patients in the first 2 hours after a conventional incident, this increased to 71% for a CBR incident. Staff training was considered the main funding priority (59%). This survey raises significant questions about the level of preparedness of Australian EDs for dealing with patients from both conventional and CBR incidents. Hospitals need to review their plans and functionality openly and objectively to ensure that their perceived preparedness is consistent with reality. In addition, they urgently require guidance as to reasonable expectations of their capacity. To that end, we recommend further development of national standards in hospital disaster planning and preparedness.

  4. The Impact Response of Composite Materials Involved in Helicopter Vulnerability Assessment: Literature Review - Part 2

    DTIC Science & Technology

    2006-04-01

    Composite Repair on a Cracked Aluminum Structure, In: Proc. 11th Int. Conf. on Composite Materials, v. 6, Gold Coast, Australia, 14-18 July, 1997...the Certification of Bonded Composite Repairs to Primary Aircraft Structure, In: Proc. 11th Int. Conf. on Composite Materials, v. 1, Gold Coast... Gold Coast, Australia, 14-18 July, 1997, ACSS, Woodhead Publ Ltd, pp. 27-35. [Berthet, 1997b] Berthet F., Devos P., and Ansart T., Demonstrating the

  5. Molecular change signal-to-noise criteria for interpreting experiments involving exposure of biological systems to weakly interacting electromagnetic fields.

    PubMed

    Vaughan, Timothy E; Weaver, James C

    2005-05-01

    We describe an approach to aiding the design and interpretation of experiments involving biological effects of weakly interacting electromagnetic fields that range from steady (dc) to microwave frequencies. We propose that if known biophysical mechanisms cannot account for an inferred, underlying molecular change signal-to-noise ratio, (S/N)gen, of a observed result, then there are two interpretation choices: (1) there is an unknown biophysical mechanism with stronger coupling between the field exposure and the ongoing biochemical process, or (2) the experiment is responding to something other than the field exposure. Our approach is based on classical detection theory, the recognition that weakly interacting fields cannot break chemical bonds, and the consequence that such fields can only alter rates of ongoing, metabolically driven biochemical reactions, and transport processes. The approach includes both fundamental chemical noise (molecular shot noise) and other sources of competing chemical change, to be compared quantitatively to the field induced change for the basic case that the field alters a single step in a biochemical network. Consistent with pharmacology and toxicology, we estimate the molecular dose (mass associated with field induced molecular change per mass tissue) resulting from illustrative low frequency field exposures for the biophysical mechanism of voltage gated channels. For perspective, we then consider electric field-mediated delivery of small molecules across human skin and into individual cells. Specifically, we consider the examples of iontophoretic and electroporative delivery of fentanyl through skin and electroporative delivery of bleomycin into individual cells. The total delivered amount corresponds to a molecular change signal and the delivery variability corresponds to generalized chemical noise. Viewed broadly, biological effects due to nonionizing fields may include animal navigation, medical applications, and environmental

  6. Effects of addictive substances during pregnancy and infancy and their analysis in biological materials.

    PubMed

    Płotka, Justyna; Narkowicz, Sylwia; Polkowska, Zaneta; Biziuk, Marek; Namieśnik, Jacek

    2014-01-01

    The use of addictive substances during pregnancy is a serious social problem, not only because of effects on the health of the woman and child, but also because drug or alcohol dependency detracts from child care and enhances the prospect of child neglect and family breakdown. Developing additive substance abuse treatment programs for pregnant women is socially important and can help ensure the health of babies, prevent subsequent developmental and behavioral problems (i.e., from intake of alcohol or other additive substances such as methamphetamine, cocaine,or heroine) and can reduce addiction costs to society. Because women of childbearing age often abuse controlled substances during their pregnancy, it is important to undertake biomonitoring of these substances in biological samples taken from the pregnant or nursing mother (e.g., blood, urine,hair, breast milk, sweat, oral fluids, etc.), from the fetus and newborn (e.g., meconium,cord blood, neonatal hair and urine) and from both the mother and fetus (i.e.,amniotic fluids and placenta). The choice of specimens to be analyzed is determined by many factors; however, the most important is knowledge of the chemical and physical characteristics of a substance and the route of it administration. Maternal and neonatal biological materials reflect exposures that occur over a specific time period, and each of these biological specimens has different advantages and disadvantages,in terms of accuracy, time window of exposure and cost/benefit ratio.Sampling the placenta may be the most important biomonitoring choice for assessing in utero exposure to addictive substances. The use of the placenta in scientific research causes a minimum of ethical problems, partly because its sampling is noninvasive, causes no harm to mother or child, and partly because, in any case,placentas are discarded and incinerated after birth. Such samples, when properly analyzed, may provide key essential information about fetal exposure to toxic

  7. Decontamination of chemical and biological warfare agents with a single multi-functional material.

    PubMed

    Amitai, Gabi; Murata, Hironobu; Andersen, Jill D; Koepsel, Richard R; Russell, Alan J

    2010-05-01

    We report the synthesis of new polymers based on a dimethylacrylamide-methacrylate (DMAA-MA) co-polymer backbone that support both chemical and biological agent decontamination. Polyurethanes containing the redox enzymes glucose oxidase and horseradish peroxidase can convert halide ions into active halogens and exert striking bactericidal activity against gram positive and gram negative bacteria. New materials combining those biopolymers with a family of N-alkyl 4-pyridinium aldoxime (4-PAM) halide-acrylate co-polymers offer both nucleophilic activity for the detoxification of organophosphorus nerve agents and internal sources of halide ions for generation of biocidal activity. Generation of free bromine and iodine was observed in the combined material resulting in bactericidal activity of the enzymatically formed free halogens that caused complete kill of E. coli (>6 log units reduction) within 1 h at 37 degrees C. Detoxification of diisopropylfluorophosphate (DFP) by the polyDMAA MA-4-PAM iodide component was dose-dependent reaching 85% within 30 min. A subset of 4-PAM-halide co-polymers was designed to serve as a controlled release reservoir for N-hydroxyethyl 4-PAM (HE 4-PAM) molecules that reactivate nerve agent-inhibited acetylcholinesterase (AChE). Release rates for HE 4-PAM were consistent with hydrolysis of the HE 4-PAM from the polymer backbone. The HE 4-PAM that was released from the polymer reactivated DFP-inhibited AChE at a similar rate to the oxime antidote 4-PAM.

  8. A study of the interface strength between protein and mineral in biological materials.

    PubMed

    Ji, Baohua

    2008-01-01

    Bone, tooth, mineralized tendon and sea shells are nanocomposites of protein and mineral with superior mechanical properties. As the mineral is so small at nanoscale, the volume fraction of the protein-mineral interface in the bulk materials can be enormously large; therefore, the mechanics of the interface should be critically important for the integrity of these biomaterials. Currently, people do not have a good understanding of the interface between protein and mineral, a hybrid interface between organic and inorganic constituents in biological materials. In this paper, a tension-shear chain (TSC) model is introduced into the Dugdale model for estimating the fracture energy of biomaterials. The strength of the hybrid interface is then studied with a "soft-hard" bi-layer fracture model, by which we find for the first time that the interface strength depends on both the size and geometry of the mineral crystal, and has been highly optimized through the miniaturization of mineral at nanoscale. This study may provide important insights into the mechanics of bone and tooth at small scale for tissue engineering in biomedical applications.

  9. Opportunities for Materials Science and Biological Research at the OPAL Research Reactor

    NASA Astrophysics Data System (ADS)

    Kennedy, S. J.

    2008-03-01

    Neutron scattering techniques have evolved over more than 1/2 century into a powerful set of tools for determination of atomic and molecular structures. Modern facilities offer the possibility to determine complex structures over length scales from ˜0.1 nm to ˜500 nm. They can also provide information on atomic and molecular dynamics, on magnetic interactions and on the location and behaviour of hydrogen in a variety of materials. The OPAL Research Reactor is a 20 megawatt pool type reactor using low enriched uranium fuel, and cooled by water. OPAL is a multipurpose neutron factory with modern facilities for neutron beam research, radioisotope production and irradiation services. The neutron beam facility has been designed to compete with the best beam facilities in the world. After six years in construction, the reactor and neutron beam facilities are now being commissioned, and we will commence scientific experiments later this year. The presentation will include an outline of the strengths of neutron scattering and a description of the OPAL research reactor, with particular emphasis on it's scientific infrastructure. It will also provide an overview of the opportunities for research in materials science and biology that will be possible at OPAL, and mechanisms for accessing the facilities. The discussion will emphasize how researchers from around the world can utilize these exciting new facilities.

  10. Evaluation of radiochemical neutron activation analysis methods for determination of arsenic in biological materials.

    PubMed

    Paul, Rick L

    2011-01-01

    Radiochemical neutron activation analysis (RNAA) with retention on hydrated manganese dioxide (HMD) has played a key role in the certification of As in biological materials at NIST. Although this method provides very high and reproducible yields and detection limits at low microgram/kilogram levels, counting geometry uncertainties may arise from unequal distribution of As in the HMD, and arsenic detection limits may not be optimal due to significant retention of other elements. An alternate RNAA procedure with separation of arsenic by solvent extraction has been investigated. After digestion of samples in nitric and perchloric acids, As(III) is extracted from 2 M sulfuric acid solution into a solution of zinc diethyldithiocarbamate in chloroform. Counting of (76)As allows quantitation of arsenic. Addition of an (77)As tracer solution prior to dissolution allows correction for chemical yield and counting geometries, further improving reproducibility. The HMD and solvent extraction procedures for arsenic were compared through analysis of SRMs 1577c (bovine liver), 1547 (peach leaves), and 1575a (pine needles). Both methods gave As results in agreement with certified values with comparable reproducibility. However, the solvent extraction method yields a factor of 3 improvement in detection limits and is less time-consuming than the HMD method. The new method shows great promise for use in As certification in reference materials.

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

    PubMed

    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.

  12. Numerical modelling of thermal effects on biological tissue during laser-material interaction

    NASA Astrophysics Data System (ADS)

    Latinovic, Z.; Sreckovic, M.; Janicijevic, M.; Ilic, J.; Radovanovic, J.

    2014-09-01

    Among numerous methods of the modelling of laser interaction with the material equivalent of biological tissue (including macroscopic and microscopic cell interaction), the case of pathogenic prostates is chosen to be studied. The principal difference between the inorganic and tissue equivalent material is the term which includes blood flow. Thermal modelling is chosen for interaction mechanisms, i.e. bio-heat equation. It was noticed that the principal problems are in selecting appropriate numerical methods, available mathematical program packages and finding all exact parameters for performing the needed calculations. As principal parameters, among them density, heat conduction, and specific heat, there are many other parameters which depend on the chosen approach (there could be up to 20 parameters, among them coefficient of time scaling, arterial blood temperature, metabolic heat source, etc). The laser type, including its wavelength which defines the quantity of absorbed energy and dynamic of irradiation, presents the term which could be modulated for the chosen problem. In this study, the program Comsol Multiphysics 3.5 is used in the simulation of prostate exposed to Nd3+:YAG laser in its fundamental mode.

  13. The use of soft x rays to study the ultrastructure of living biological material.

    PubMed

    Stead, A D; Cotton, R A; Duckett, J G; Goode, J A; Page, A M; Ford, T W

    1995-01-01

    Imaging biological specimens with soft x rays offers several potential benefits over electron microscopy, and these are briefly reviewed. The disadvantages, most notably radiation-induced structural changes, have been investigated and images of irradiated algal cells (Chlorella) are presented. In soft x-ray contact microscopy the image is recorded rapidly to avoid both natural and radiation-induced movement and this technique has been used to study the ultrastructural effects of electron microscopy fixatives. In the epidermal hairs of tomato plants there are numerous strands of cytoplasm which, by light microscopy, appear to traverse the vacuole but are rarely seen by electron microscopy. However, by soft x-ray contact microscopy these strands and the organelles within them can be successfully imaged. Moreover, examination by soft x-ray contact microscopy of the cytoplasm in a fixed material shows that these strands are not present in chemically fixed material. This paper also reports the use of soft x-ray contact microscopy to examine the abscission cells found within the protonema of a moss (Bryum tenuisetum) and compares the images to those obtained by light and electron microscopy.

  14. Transient analysis of a thermal storage unit involving a phase change material

    NASA Technical Reports Server (NTRS)

    Griggs, E. I.; Pitts, D. R.; Humphries, W. R.

    1974-01-01

    The transient response of a single cell of a typical phase change material type thermal capacitor has been modeled using numerical conductive heat transfer techniques. The cell consists of a base plate, an insulated top, and two vertical walls (fins) forming a two-dimensional cavity filled with a phase change material. Both explicit and implicit numerical formulations are outlined. A mixed explicit-implicit scheme which treats the fin implicity while treating the phase change material explicitly is discussed. A band algorithmic scheme is used to reduce computer storage requirements for the implicit approach while retaining a relatively fine grid. All formulations are presented in dimensionless form thereby enabling application to geometrically similar problems. Typical parametric results are graphically presented for the case of melting with constant heat input to the base of the cell.

  15. Recent advances in the involvement of long non-coding RNAs in neural stem cell biology and brain pathophysiology.

    PubMed

    Antoniou, Daphne; Stergiopoulos, Athanasios; Politis, Panagiotis K

    2014-01-01

    Exploration of non-coding genome has recently uncovered a growing list of formerly unknown regulatory long non-coding RNAs (lncRNAs) with important functions in stem cell pluripotency, development and homeostasis of several tissues. Although thousands of lncRNAs are expressed in mammalian brain in a highly patterned manner, their roles in brain development have just begun to emerge. Recent data suggest key roles for these molecules in gene regulatory networks controlling neuronal and glial cell differentiation. Analysis of the genomic distribution of genes encoding for lncRNAs indicates a physical association of these regulatory RNAs with transcription factors (TFs) with well-established roles in neural differentiation, suggesting that lncRNAs and TFs may form coherent regulatory networks with important functions in neural stem cells (NSCs). Additionally, many studies show that lncRNAs are involved in the pathophysiology of brain-related diseases/disorders. Here we discuss these observations and investigate the links between lncRNAs, brain development and brain-related diseases. Understanding the functions of lncRNAs in NSCs and brain organogenesis could revolutionize the basic principles of developmental biology and neuroscience.

  16. Integration of biological data by kernels on graph nodes allows prediction of new genes involved in mitotic chromosome condensation

    PubMed Central

    Hériché, Jean-Karim; Lees, Jon G.; Morilla, Ian; Walter, Thomas; Petrova, Boryana; Roberti, M. Julia; Hossain, M. Julius; Adler, Priit; Fernández, José M.; Krallinger, Martin; Haering, Christian H.; Vilo, Jaak; Valencia, Alfonso; Ranea, Juan A.; Orengo, Christine; Ellenberg, Jan

    2014-01-01

    The advent of genome-wide RNA interference (RNAi)–based screens puts us in the position to identify genes for all functions human cells carry out. However, for many functions, assay complexity and cost make genome-scale knockdown experiments impossible. Methods to predict genes required for cell functions are therefore needed to focus RNAi screens from the whole genome on the most likely candidates. Although different bioinformatics tools for gene function prediction exist, they lack experimental validation and are therefore rarely used by experimentalists. To address this, we developed an effective computational gene selection strategy that represents public data about genes as graphs and then analyzes these graphs using kernels on graph nodes to predict functional relationships. To demonstrate its performance, we predicted human genes required for a poorly understood cellular function—mitotic chromosome condensation—and experimentally validated the top 100 candidates with a focused RNAi screen by automated microscopy. Quantitative analysis of the images demonstrated that the candidates were indeed strongly enriched in condensation genes, including the discovery of several new factors. By combining bioinformatics prediction with experimental validation, our study shows that kernels on graph nodes are powerful tools to integrate public biological data and predict genes involved in cellular functions of interest. PMID:24943848

  17. “Standoff Biofinder” for Fast, Noncontact, Nondestructive, Large-Area Detection of Biological Materials for Planetary Exploration

    DOE PAGES

    Misra, Anupam K.; Acosta-Maeda, Tayro E.; Sharma, Shiv K.; ...

    2016-09-01

    In this paper, we developed a prototype instrument called the Standoff Biofinder, which can quickly locate biological material in a 500 cm2 area from a 2 m standoff distance with a detection time of 0.1 s. All biogenic materials give strong fluorescence signals when excited with UV and visible lasers. In addition, the luminescence decay time of biogenic compounds is much shorter (<100 ns) than the micro- to millisecond decay time of transition metal ions and rare-earth ions in minerals and rocks. The Standoff Biofinder takes advantage of the short lifetime of biofluorescent materials to obtain real-time fluorescence images thatmore » show the locations of biological materials among luminescent minerals in a geological context. The Standoff Biofinder instrument will be useful for locating biological material during future NASA rover, lander, and crewed missions. Additionally, the instrument can be used for nondestructive detection of biological materials in unique samples, such as those obtained by sample return missions from the outer planets and asteroids. Finally, the Standoff Biofinder also has the capacity to detect microbes and bacteria on space instruments for planetary protection purposes.« less

  18. “Standoff Biofinder” for Fast, Noncontact, Nondestructive, Large-Area Detection of Biological Materials for Planetary Exploration

    SciTech Connect

    Misra, Anupam K.; Acosta-Maeda, Tayro E.; Sharma, Shiv K.; McKay, Christopher P.; Gasda, Patrick J.; Taylor, G. Jeffrey; Lucey, Paul G.; Flynn, Luke; Abedin, M. Nurul; Clegg, Samuel M.; Wiens, Roger

    2016-09-01

    In this paper, we developed a prototype instrument called the Standoff Biofinder, which can quickly locate biological material in a 500 cm2 area from a 2 m standoff distance with a detection time of 0.1 s. All biogenic materials give strong fluorescence signals when excited with UV and visible lasers. In addition, the luminescence decay time of biogenic compounds is much shorter (<100 ns) than the micro- to millisecond decay time of transition metal ions and rare-earth ions in minerals and rocks. The Standoff Biofinder takes advantage of the short lifetime of biofluorescent materials to obtain real-time fluorescence images that show the locations of biological materials among luminescent minerals in a geological context. The Standoff Biofinder instrument will be useful for locating biological material during future NASA rover, lander, and crewed missions. Additionally, the instrument can be used for nondestructive detection of biological materials in unique samples, such as those obtained by sample return missions from the outer planets and asteroids. Finally, the Standoff Biofinder also has the capacity to detect microbes and bacteria on space instruments for planetary protection purposes.

  19. Third-Party Cooperation: How Reducing Material Involvement Enhances Contributions to the Public Good.

    PubMed

    Losecaat Vermeer, Annabel B; Heerema, Roeland L; Sanfey, Alan G

    2016-03-01

    Decisions to cooperate are often delegated to a third party. We examined whether cooperation differs when decisions are made for a third party compared with ourselves and specified which motives are important for third-party cooperation. Participants played multiple rounds of a public goods game (PGG). In Study 1, we varied personal involvement from high to low; participants played for themselves (Self), for themselves and a third party (Shared), and solely for a third party (Third Party). Participants contributed most when personal involvement was lowest (i.e., Third Party) and least when personal involvement was high (i.e., Self). Study 2 explored if social motives underlie third-party cooperation by comparing cooperation with social (human) and non-social (computer) group members. Reducing personal involvement in the PGG (i.e., Third Party) increased cooperation in social contexts compared with non-social contexts, indicating enhanced collective interest. Increased cooperation for a third party may result from taking the other's perspective, thereby increasing social norm preferences.

  20. Department Involvement in Instructional Materials Development for ODL Study at the Zimbabwe Open University (ZOU)

    ERIC Educational Resources Information Center

    Tanyanyiwa, Vincent Itai; Mutambanengwe, Betty

    2015-01-01

    The teaching and designing of modules at Zimbabwe Open University (ZOU) is the principal responsibility of a single body of teaching staff, although some authors and content reviewers could be sourced from elsewhere if they are not available in ZOU. This survey, through a case study, examines the involvement of lecturers and staff in the…

  1. Evaluation of Online, On-Demand Science Professional Development Material Involving Two Different Implementation Models

    ERIC Educational Resources Information Center

    Sherman, Greg; Byers, Al; Rapp, Steve

    2008-01-01

    This report presents pilot-test results for a science professional development program featuring online, on-demand materials developed by the National Science Teachers Association. During the spring 2006 semester, 45 middle school teachers from three different school districts across the United States participated in a professional development…

  2. Preparation of polysulfone materials on nickel foam for solid-phase microextraction of floxacin in water and biological samples.

    PubMed

    Guan, Xiujuan; Cheng, Ting; Wang, Shuxia; Liu, Xiaoyan; Zhang, Haixia

    2017-03-01

    Solid-phase microextraction with polysulfone and molecularly imprinted polymers as coating on nickel foam were used to adsorb and enrich floxacin drugs. The preparation method is simple and reproducible to obtain the materials with controlled thickness. After evaluation by scanning electron microscope and various adsorption experiments, the materials were used to adsorb analytes in water samples and biological samples. Coupling with chromatographic analysis, the method recoveries are satisfactory with 90.0-104.8% and 79.31-107.1% for water and biological samples. The method repeatability by intra- and interday experiments shows that the RSD values for water and biological samples were 1.0-9.9% and 1.7-10.3%, with the quantitative limits of three floxacin drugs as 3.0-6.2 μg L(-1). Graphical Abstract Preparation diagram of polysulfone material.

  3. Near-infrared spectroscopy and hyperspectral imaging: non-destructive analysis of biological materials.

    PubMed

    Manley, Marena

    2014-12-21

    Near-infrared (NIR) spectroscopy has come of age and is now prominent among major analytical technologies after the NIR region was discovered in 1800, revived and developed in the early 1950s and put into practice in the 1970s. Since its first use in the cereal industry, it has become the quality control method of choice for many more applications due to the advancement in instrumentation, computing power and multivariate data analysis. NIR spectroscopy is also increasingly used during basic research performed to better understand complex biological systems, e.g. by means of studying characteristic water absorption bands. The shorter NIR wavelengths (800-2500 nm), compared to those in the mid-infrared (MIR) range (2500-15 000 nm) enable increased penetration depth and subsequent non-destructive, non-invasive, chemical-free, rapid analysis possibilities for a wide range of biological materials. A disadvantage of NIR spectroscopy is its reliance on reference methods and model development using chemometrics. NIR measurements and predictions are, however, considered more reproducible than the usually more accurate and precise reference methods. The advantages of NIR spectroscopy contribute to it now often being favoured over other spectroscopic (colourimetry and MIR) and analytical methods, using chemicals and producing chemical waste, such as gas chromatography (GC) and high performance liquid chromatography (HPLC). This tutorial review intends to provide a brief overview of the basic theoretical principles and most investigated applications of NIR spectroscopy. In addition, it considers the recent development, principles and applications of NIR hyperspectral imaging. NIR hyperspectral imaging provides NIR spectral data as a set of images, each representing a narrow wavelength range or spectral band. The advantage compared to NIR spectroscopy is that, due to the additional spatial dimension provided by this technology, the images can be analysed and visualised as

  4. Mechanical properties and structure of the biological multilayered material system, Atractosteus spatula scales.

    PubMed

    Allison, P G; Chandler, M Q; Rodriguez, R I; Williams, B A; Moser, R D; Weiss, C A; Poda, A R; Lafferty, B J; Kennedy, A J; Seiter, J M; Hodo, W D; Cook, R F

    2013-02-01

    During recent decades, research on biological systems such as abalone shell and fish armor has revealed that these biological systems employ carefully arranged hierarchical multilayered structures to achieve properties of high strength, high ductility and light weight. Knowledge of such structures may enable pathways to design bio-inspired materials for various applications. This study was conducted to investigate the spatial distribution of structure, chemical composition and mechanical properties in mineralized fish scales of the species Atractosteus spatula. Microindentation tests were conducted, and cracking patterns and damage sites in the scales were examined to investigate the underlying protective mechanisms of fish scales under impact and penetration loads. A difference in nanomechanical properties was observed, with a thinner, stiffer and harder outer layer (indentation modulus ∼69 GPa and hardness ∼3.3 GPa) on a more compliant and thicker inner layer (indentation modulus ∼14.3 GPa and hardness ∼0.5 GPa). High-resolution scanning electron microscopy imaging of a fracture surface revealed that the outer layer contained oriented nanorods embedded in a matrix, and that the nanostructure of the inner layer contained fiber-like structures organized in a complex layered pattern. Damage patterns formed during microindentation show complex deformation mechanisms. Images of cracks identify growth through the outer layer, then deflection along the interface before growing and arresting in the inner layer. High-magnification images of the crack tip in the inner layer show void-linking and fiber-bridging exhibiting inelastic behavior. The observed difference in mechanical properties and unique nanostructures of different layers may have contributed to the resistance of fish scales to failure by impact and penetration loading. Published by Elsevier Ltd.

  5. Untangling the Reaction Mechanisms Involved in the Explosive Decomposition of Model Compounds of Energetic Materials

    DTIC Science & Technology

    2014-06-11

    turbomolecular pump. The pulsed valve fired 286 µs prior to the Q- switch of the Nd:YAG laser . The pulsed valve was connected to the middle entrance of a T...the last decades: the decomposition of model compounds of nitrohydrocarbon-, nitramine-, and nitro-ester-based energetic materials. We trigger ...energies below the ionization energy of the target molecules in a contamination free ultra high vacuum setup at low temperatures. An investigation of these

  6. Piezo- and Flexoelectric Membrane Materials Underlie Fast Biological Motors in the Ear

    PubMed Central

    Breneman, Kathryn D.; Rabbitt, Richard D.

    2010-01-01

    The mammalian inner ear is remarkably sensitive to quiet sounds, exhibits over 100dB dynamic range, and has the exquisite ability to discriminate closely spaced tones even in the presence of noise. This performance is achieved, in part, through active mechanical amplification of vibrations by sensory hair cells within the inner ear. All hair cells are endowed with a bundle of motile microvilli, stereocilia, located at the apical end of the cell, and the more specialized outer hair cells (OHC’s) are also endowed with somatic electromotility responsible for changes in cell length in response to perturbations in membrane potential. Both hair bundle and somatic motors are known to feed energy into the mechanical vibrations in the inner ear. The biophysical origin and relative significance of the motors remains a subject of intense research. Several biological motors have been identified in hair cells that might underlie the motor(s), including a cousin of the classical ATP driven actin-myosin motor found in skeletal muscle. Hydrolysis of ATP, however, is much too slow to be viable at audio frequencies on a cycle-by-cycle basis. Heuristically, the OHC somatic motor behaves as if the OHC lateral wall membrane were a piezoelectric material and the hair bundle motor behaves as if the plasma membrane were a flexoelectric material. We propose these observations from a continuum materials perspective are literally true. To examine this idea, we formulated mathematical models of the OHC lateral wall “piezoelectric” motor and the more ubiquitous “flexoelectric” hair bundle motor. Plausible biophysical mechanisms underlying piezo- and flexoelectricity were established. Model predictions were compared extensively to the available data. The models were then applied to study the power conversion efficiency of the motors. Results show that the material properties of the complex membranes in hair cells provide them with the ability to convert electrical power available in

  7. The Elemental Analysis of Biological and Environmental Materials Using a 2MEV Proton Beam

    NASA Astrophysics Data System (ADS)

    Arshed, Waheed

    Available from UMI in association with The British Library. A programme has been developed to simulate the proton induced x-ray emission (PIXE) spectra and its uses have been described. The PIXE technique has been applied to the analysis of new biological reference materials which consist of IAEA human diet samples and NIST leaf samples. Homogeneity of these and two existing reference materials, IAEA soil -7 and Bowen's kale, has also been determined at the mug scale. A subsample representative of a material is ascertained by determination of sampling factors for the elements detected in the material. Proton induced gamma-ray emission (PIGE) analysis in conjunction with PIXE has been employed to investigate F and other elemental concentrations found in human teeth samples. The mean F concentration in enamel and dentine parts of teeth followed an age dependent model. Concentrations of Ca and P were found to be higher in the enamel than in the dentine. Analysis of blood and its components in the study of elemental models in sickle cell disease in Nigerians has been carried out. Comparisons revealed that Cl, Ca and Cu were at higher levels whereas K, Fe, Zn and Rb were at lower levels in the whole blood of the sicklers compared to controls. Similar results were obtained for the erythrocytes except that Br was found at higher concentration in erythrocytes of the sicklers. Higher concentrations of Cl, K, Fe and Cu were also observed in plasma of the sicklers compared to controls. PIXE and scanning electron microscopy (SEM) were used in the characterization of the Harmattan dust particulates collected at Kano and Ife. Most of the elements were found to be at higher concentrations as compared to those found in Recife (Brazil) and Toronto (Canada). The value of total suspended particulate was above the relevant national air quality standards. PIXE in conjunction with Rutherford backscattering spectrometry and instrumental neutron activation analysis was employed in the

  8. Differential laser-induced perturbation spectroscopy and fluorescence imaging for biological and materials sensing

    NASA Astrophysics Data System (ADS)

    Burton, Dallas Jonathan

    The field of laser-based diagnostics has been a topic of research in various fields, more specifically for applications in environmental studies, military defense technologies, and medicine, among many others. In this dissertation, a novel laser-based optical diagnostic method, differential laser-induced perturbation spectroscopy (DLIPS), has been implemented in a spectroscopy mode and expanded into an imaging mode in combination with fluorescence techniques. The DLIPS method takes advantage of deep ultraviolet (UV) laser perturbation at sub-ablative energy fluences to photochemically cleave bonds and alter fluorescence signal response before and after perturbation. The resulting difference spectrum or differential image adds more information about the target specimen, and can be used in combination with traditional fluorescence techniques for detection of certain materials, characterization of many materials and biological specimen, and diagnosis of various human skin conditions. The differential aspect allows for mitigation of patient or sample variation, and has the potential to develop into a powerful, noninvasive optical sensing tool. The studies in this dissertation encompass efforts to continue the fundamental research on DLIPS including expansion of the method to an imaging mode. Five primary studies have been carried out and presented. These include the use of DLIPS in a spectroscopy mode for analysis of nitrogen-based explosives on various substrates, classification of Caribbean fruit flies versus Caribbean fruit flies that have been irradiated with gamma rays, and diagnosis of human skin cancer lesions. The nitrogen-based explosives and Caribbean fruit flies have been analyzed with the DLIPS scheme using the imaging modality, providing complementary information to the spectroscopic scheme. In each study, a comparison between absolute fluorescence signals and DLIPS responses showed that DLIPS statistically outperformed traditional fluorescence techniques

  9. Solid phase immobilization of optically responsive liposomes insol-gel materials for chemical and biological sensing

    SciTech Connect

    Yamanaka, Stacey A.; Charych, Deborah H.; Loy, Douglas A.; Sasaki, Darryl Y.

    1997-04-01

    Liposomes enhanced with surface recognition groups have previously been found to have high affinity for heavy metal ions and virus particles with unique fluorescent and colorimetric responses, respectively. These lipid aggregate systems have now been successfully immobilized in a silica matrix via the sol-gel method, affording sensor materials that are robust, are easily handled, and offer optical clarity. The mild processing conditions allow quantitative entrapment of preformed liposomes without modification of the aggregate structure. Lipid extraction studies of immobilized nonpolymerized liposomes showed no lipid leakage in aqueous solution over a period of 3 months. Heavy metal fluorescent sensor materials prepared with 5 percent N-[8-[1-octadecyl-2-(9-(1-pyrenyl)nonyl)-rac-glyceroyl]-3,6-dioxaoctyl]imino acid/distearylphosphatidylcholineliposomes exhibited a 4-50-fold enhancement in sensitivity to various metal ions compared to that of the liposomes in free solution. Through ionic attraction the anionic silicate surface, at the experimental pH of 7.4, may act as a preconcentrator of divalent metal ions, boosting the gel's internal metal concentration. Entrapped sialic acid-coated polydiacetylene liposomes responded with colorimetric signaling to influenza virus X31, although slower than the free liposomes in solution. The successful transport of the virus (50-100 nm diameter) reveals a large pore diameter of the gel connecting the liposome to the bulk solution. The porous and durable silica matrix additionally provides a protective barrier to biological attack (bacterial, fungal) and allows facile recycling of the liposome heavy metal sensor.

  10. Utilization of liquid human wastes and introduction into the material cycling in biological life-support systems

    NASA Astrophysics Data System (ADS)

    Kovaleva, N. P.>; Ushakova, S. A.; Gribovskaya, I. V.; Kudenko, U. A.

    The possibilities of step-by-step utilization of liquid human wastes in biological life-support systems on long-functioning space stations have been considered in this work. Utilization involves "wet" urine incineration with hydrogen peroxide at normal pressure and 90 - 95°C temperature, urease-enzymic decomposition of urine and biological desalination in the higher plant link. The soybean flour was used as a source of urease. Growing soya plants as a component of the higher plant link would give a steady source of urease to the system. To decompose urea (9-15g) contained in 1l of incinerated urine we used 0.5 - 1 g of soy flour. The duration of hydrolysis of daily urea excreted by a human is 70 - 95 hours. It is supposed that ammonia excreted in the reaction of urea decomposition will be processed by nitrifying bacteria. The concentration of total nitrogen in urine after urea hydrolysis and removal of ammonia formed during the reaction constituted 0.6 - 1.2 g/l. Further biological desalination was carried out in the higher plant link, for that the edible salt-accumulating halophytes Salicornia europaea were used. To grow this plant under the aqueous culture conditions, the urine was additionally mineralized at 180 °C after incineration and decomposition of urea. The process of additional mineralization was related to the necessity of removal of organic materials and nitrogen residues, which higher concentration under the aqueous culture conditions has negative effect on plants. The volume of the nutrient solution for growing 6 plants of Salicornia europaea was 1.5 l (daily norm of urine excreted by human), the planting area was 0.032 m2. By the end of vegetation the productivity and mineral composition of Salicornia europaea plants were analyzed. The productivity of plants grown on liquid human wastes (the experiment) practically was not different from the productivity of plants grown on the mineral solution with sodium chloride (checkout). In experimental

  11. Materials design considerations involved in the fabrication of implantable bionics by metallization of ceramic substrates.

    PubMed

    Patel, Sunil; Guenther, Thomas; Dodds, Christopher W D; Kolke, Sergej; Privat, Karen L; Matteucci, Paul B; Suaning, Gregg J

    2013-01-01

    The Pt metallization of co-fired Al2O3/SiO2 substrates containing Pt feedthroughs was shown to be a suitable means to construct implantable bionics. The use of forge welding to join an electrode to such a metallized feedthrough was demonstrated and subsequently evaluated through the use of metallography and electron microscopy. Metallurgical phenomena involved in forge welding relevant to the fabrication of all types of biomedical implants are discussed within this paper. The affect of thermal profiles used in brazing or welding to build implantable devices from metal components is analysed and the case for considered selection of alloys in implant design is put forward.

  12. Studies Involving the Synthesis and Characterization of High Energy Magnet Materials

    DTIC Science & Technology

    1991-01-11

    makE Nd2Fe14B magnets into a commercial reality. SmTiFe9Co2 has been established as a promising permanent magnet material. Pr2(Co,Fe)17 has also been...magnets. The systems studied with this in mind fall into three structural types: those having (a) the Nd2Fe14B structure, (b) the ThMn1 2 structure and (c...this report by giving terse summaries of 9 of the papers. The work has been a part of the world-wide effort to make Nd2Fe14B magnets into a commercial

  13. Exposure of biological material to ultra-wideband electromagnetic pulses: dosimetric implications.

    PubMed

    Simicevic, Neven

    2007-06-01

    Interest in ultra-wideband (UWB) electromagnetic pulses in the communications industry and various applications in biotechnology and medicine is constantly increasing. While more and more scientific research of bioelectromagnetic phenomena is focusing on bioeffects of exposure to non-ionizing UWB pulses, characterization of those effects is far from complete. In this paper, a synthesis of experimental studies from the point of computational modeling is presented. The complexity of the experiments requires a numerical rather than an analytical approach. Solving Maxwell's equations using a finite-difference time-domain (FDTD) method is a necessary step in visualizing and understanding broadband response. The advantages of this method include having almost no limits in the description of geometrical and dispersive properties of the simulated material, numerical robustness, and appropriateness for the computer technology of today. Some of the results of the computation and their importance in future experimental design are discussed. Improvements in the computational modeling and dielectric material description are suggested. This paper aims at justifying a scientific basis for UWB exposure safety standards relevant for setting the non-ionizing UWB radiation exposure guidelines. The results of this research will be of interest to people who work with electronic devices involving UWB radiation.

  14. Biological inspiration in optics and photonics: harnessing nature's light manipulation strategies for multifunctional optical materials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kolle, Mathias; Sandt, Joseph D.; Nagelberg, Sara N.; Zarzar, Lauren D.; Kreysing, Moritz; Vukusic, Peter

    2016-03-01

    The precise control of light-matter interactions is crucial for the majority of known biological organisms in their struggle to survive. Many species have evolved unique methods to manipulate light in their environment using a variety of physical effects including pigment-induced, spectrally selective absorption or light interference in photonic structures that consist of micro- and nano-periodic material morphologies. In their optical performance, many of the known biological photonic systems are subject to selection criteria not unlike the requirements faced in the development of novel optical technology. For this reason, biological light manipulation strategies provide inspiration for the creation of tunable, stimuli-responsive, adaptive material platforms that will contribute to the development of multifunctional surfaces and innovative optical technology. Biomimetic and bio-inspired approaches for the manufacture of photonic systems rely on self-assembly and bottom-up growth techniques often combined with conventional top-down manufacturing. In this regard, we can benefit in several ways from highly sophisticated material solutions that have convergently evolved in various organisms. We explore design concepts found in biological photonic architectures, seek to understand the mechanisms underlying morphogenesis of bio-optical systems, aim to devise viable manufacturing strategies that can benefit from insight in biological formation processes and the use of established synthetic routines alike, and ultimately strive to realize new photonic materials with tailor-made optical properties. This talk is focused on the identification of biological role model photonic architectures, a brief discussion of recently developed bio-inspired photonic structures, including mechano-sensitive color-tunable photonic fibers and reconfigurable fluid micro-lenses. Potentially, early-stage results in studying and harnessing the structure-forming capabilities of living cells that

  15. [Survey on accidental exposure to biological materials in the Hospital-University Complex of Sassari during the period 1995-2000].

    PubMed

    Masia, M D; Castiglia, P; Busonera, B; Valca, D; Maida, I; Mura, I

    2004-01-01

    To study professional exposure to biological materials an investigation was carried out in the Hospital-University Complex of Sassari during the period January 1st 1995-December 31 2000. 1003 occupational accidents were notified (incidence rate=6%). Infirmaries were the most at risk category (45%) and about the half part of the accidents occurred in surgical area (44.7%). The most frequent accident was needle puncture (53%); exposure involved principally the hands (76.3%). The basal serology of injured personnel showed low positivity for any HBV markers (72.7%), HCV (0.4%) and no positivity for HIV; while high levels were found among source patients. From the comparison between serological data (injured vs source), when ascertainable, emerged a biological hazard of 7.7% for HBV, 30.2% for HCV and 3.2% for HIV; however no seroconversions were observed at follow up. The study also pointed out the need of improve prevention programmes.

  16. The effect of terminal sterilization on the material properties and in vivo remodeling of a porcine dermal biologic scaffold.

    PubMed

    Dearth, Christopher L; Keane, Timothy J; Carruthers, Christopher A; Reing, Janet E; Huleihel, Luai; Ranallo, Christian A; Kollar, Elizabeth W; Badylak, Stephen F

    2016-03-01

    Biologic scaffolds composed of extracellular matrix are commonly used in a variety of surgical procedures. The Food and Drug Administration typically regulates biologic scaffolds as medical devices, thus requiring terminal sterilization prior to clinical use. However, to date, no consensus exists for the most effective yet minimally destructive sterilization protocol for biologic scaffold materials. The objective of the present study was to characterize the effect of ethylene oxide, gamma irradiation and electron beam (e-beam) irradiation on the material properties and the elicited in vivo remodeling response of a porcine dermal biologic scaffold. Outcome measures included biochemical, structural, and mechanical properties as well as cytocompatibility in vitro. In vivo evaluation utilized a rodent model to examine the host response to the materials following 7, 14, and 35 days. The host response to each experimental group was determined by quantitative histologic methods and by immunolabeling for macrophage polarization (M1/M2). In vitro results show that increasing irradiation dosage resulted in a dose dependent decrease in mechanical properties compared to untreated controls. Ethylene oxide-treated porcine dermal ECM resulted in decreased DNA content, extractable total protein, and bFGF content compared to untreated controls. All ETO treated, gamma irradiated, and e-beam irradiated samples had similar cytocompatibility scores in vitro. However, in vivo results showed that increasing dosages of e-beam and gamma irradiation elicited an increased rate of degradation of the biologic scaffold material following 35 days. The FDA typically regulates biologic scaffolds derived from mammalian tissues as medical devices, thus requiring terminal sterilization prior to clinical use. However, there is little data and no consensus for the most effective yet minimally destructive sterilization protocol for such materials. The present study characterized the effect of common

  17. Technique for examining biological materials using diffuse reflectance spectroscopy and the kubelka-munk function

    DOEpatents

    Alfano, Robert R.; Yang, Yuanlong

    2003-09-02

    Method and apparatus for examining biological materials using diffuse reflectance spectroscopy and the Kubelka-Munk function. In one aspect, the method is used to determine whether a tissue sample is cancerous or not and comprises the steps of (a) measuring the diffuse reflectance from the tissue sample at a first wavelength and at a second wavelength, wherein the first wavelength is a wavelength selected from the group consisting of 255-265 nm and wherein the second wavelength is a wavelength selected from the group consisting of 275-285 nm; (b) using the Kubelka-Munk function to transform the diffuse reflectance measurement obtained at the first and second wavelengths; and (c) comparing a ratio or a difference of the transformed Kubelka-Munk measurements at the first and second wavelengths to appropriate standards determine whether or not the tissue sample is cancerous. One can use the spectral profile of KMF between 250 nm to 300 nm to determine whether or not the tissue sample is cancerous or precancerous. According to the value at the first and second wavelengths determine whether or not the malignant tissue is invasive or mixed invasive and in situ or carcinoma in situ.

  18. The biological impacts of ingested radioactive materials on the pale grass blue butterfly

    PubMed Central

    Nohara, Chiyo; Hiyama, Atsuki; Taira, Wataru; Tanahara, Akira; Otaki, Joji M.

    2014-01-01

    A massive amount of radioactive materials has been released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident, but its biological impacts have rarely been examined. Here, we have quantitatively evaluated the relationship between the dose of ingested radioactive cesium and mortality and abnormality rates using the pale grass blue butterfly, Zizeeria maha. When larvae from Okinawa, which is likely the least polluted locality in Japan, were fed leaves collected from polluted localities, mortality and abnormality rates increased sharply at low doses in response to the ingested cesium dose. This dose-response relationship was best fitted by power function models, which indicated that the half lethal and abnormal doses were 1.9 and 0.76 Bq per larva, corresponding to 54,000 and 22,000 Bq per kilogram body weight, respectively. Both the retention of radioactive cesium in a pupa relative to the ingested dose throughout the larval stage and the accumulation of radioactive cesium in a pupa relative to the activity concentration in a diet were highest at the lowest level of cesium ingested. We conclude that the risk of ingesting a polluted diet is realistic, at least for this butterfly, and likely for certain other organisms living in the polluted area. PMID:24844938

  19. The biological impacts of ingested radioactive materials on the pale grass blue butterfly.

    PubMed

    Nohara, Chiyo; Hiyama, Atsuki; Taira, Wataru; Tanahara, Akira; Otaki, Joji M

    2014-05-15

    A massive amount of radioactive materials has been released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident, but its biological impacts have rarely been examined. Here, we have quantitatively evaluated the relationship between the dose of ingested radioactive cesium and mortality and abnormality rates using the pale grass blue butterfly, Zizeeria maha. When larvae from Okinawa, which is likely the least polluted locality in Japan, were fed leaves collected from polluted localities, mortality and abnormality rates increased sharply at low doses in response to the ingested cesium dose. This dose-response relationship was best fitted by power function models, which indicated that the half lethal and abnormal doses were 1.9 and 0.76 Bq per larva, corresponding to 54,000 and 22,000 Bq per kilogram body weight, respectively. Both the retention of radioactive cesium in a pupa relative to the ingested dose throughout the larval stage and the accumulation of radioactive cesium in a pupa relative to the activity concentration in a diet were highest at the lowest level of cesium ingested. We conclude that the risk of ingesting a polluted diet is realistic, at least for this butterfly, and likely for certain other organisms living in the polluted area.

  20. Thresholding for biological material detection in real-time multispectral imaging

    NASA Astrophysics Data System (ADS)

    Yoon, Seung Chul; Park, Bosoon; Lawrence, Kurt C.; Windham, William R.

    2005-09-01

    Recently, hyperspectral image analysis has proved successful for a target detection problem encountered in remote sensing as well as near sensing utilizing in situ instrumentation. The conventional global bi-level thresholding for target detection, such as the clustering-based Otsu's method, has been inadequate for the detection of biologically harmful material on foods that has a large degree of variability in size, location, color, shape, texture, and occurrence time. This paper presents multistep-like thresholding based on kernel density estimation for the real-time detection of harmful contaminants on a food product presented in multispectral images. We are particularly concerned with the detection of fecal contaminants on poultry carcasses in real-time. In the past, we identified 2 optimal wavelength bands and developed a real-time multispectral imaging system using a common aperture camera and a globally optimized thresholding method from a ratio of the optimal bands. This work extends our previous study by introducing a new decision rule to detect fecal contaminants on a single bird level. The underlying idea is to search for statistical separability along the two directions defined by the global optimal threshold vector and its orthogonal vector. Experimental results with real birds and fecal samples in different amounts are provided.

  1. Coupling solid-phase microextraction and laser desorption ionization for rapid identification of biological material.

    PubMed

    Perera, Sirantha; Berthod, Alain; Dodbiba, Edra; Armstrong, Daniel W

    2012-04-15

    Solid phase microextraction (SPME) use small fibers directly plunged in the solution under investigation to quickly extract and quantify by different techniques the amount of selected dissolved compounds. Biological materials, peptides or proteins are accurately identified by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). They are difficult to extract by SPME. This work looks for a chemical to be deposited onto fibers and able to act as a good SPME extractant as well as efficient matrix for MALDI detection. 3-Hydroxy-2-naphthoic acid (HNA) and 2-hydroxy-1-(2-hydroxy-4-sulfo-1-naphthylazo)-3-naphthoic acid (HHSNNA) were compared to two classical matrices: α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydrobenzoic acid (DHB). Bound to silica particles, DHB and HNA were found to be good MALDI matrices. Only the wide pore particles gave observable spectra. These particles were then attached in a thin layer onto wires to be used as fiber tips in SPME. Fibers loaded with peptides were introduced into the mass spectrometer to record fiber laser desorption ionization (FILDI) spectra. SPME-FILDI experiments could quickly identify peptides and proteins in solutions. More work is needed to find the best matrix and the way to fix it onto the fiber. Copyright © 2012 John Wiley & Sons, Ltd.

  2. The biological impacts of ingested radioactive materials on the pale grass blue butterfly

    NASA Astrophysics Data System (ADS)

    Nohara, Chiyo; Hiyama, Atsuki; Taira, Wataru; Tanahara, Akira; Otaki, Joji M.

    2014-05-01

    A massive amount of radioactive materials has been released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident, but its biological impacts have rarely been examined. Here, we have quantitatively evaluated the relationship between the dose of ingested radioactive cesium and mortality and abnormality rates using the pale grass blue butterfly, Zizeeria maha. When larvae from Okinawa, which is likely the least polluted locality in Japan, were fed leaves collected from polluted localities, mortality and abnormality rates increased sharply at low doses in response to the ingested cesium dose. This dose-response relationship was best fitted by power function models, which indicated that the half lethal and abnormal doses were 1.9 and 0.76 Bq per larva, corresponding to 54,000 and 22,000 Bq per kilogram body weight, respectively. Both the retention of radioactive cesium in a pupa relative to the ingested dose throughout the larval stage and the accumulation of radioactive cesium in a pupa relative to the activity concentration in a diet were highest at the lowest level of cesium ingested. We conclude that the risk of ingesting a polluted diet is realistic, at least for this butterfly, and likely for certain other organisms living in the polluted area.

  3. MyLabStocks: a web-application to manage molecular biology materials.

    PubMed

    Chuffart, Florent; Yvert, Gaël

    2014-05-01

    Laboratory stocks are the hardware of research. They must be stored and managed with mimimum loss of material and information. Plasmids, oligonucleotides and strains are regularly exchanged between collaborators within and between laboratories. Managing and sharing information about every item is crucial for retrieval of reagents, for planning experiments and for reproducing past experimental results. We have developed a web-based application to manage stocks commonly used in a molecular biology laboratory. Its functionalities include user-defined privileges, visualization of plasmid maps directly from their sequence and the capacity to search items from fields of annotation or directly from a query sequence using BLAST. It is designed to handle records of plasmids, oligonucleotides, yeast strains, antibodies, pipettes and notebooks. Based on PHP/MySQL, it can easily be extended to handle other types of stocks and it can be installed on any server architecture. MyLabStocks is freely available from: https://forge.cbp.ens-lyon.fr/redmine/projects/mylabstocks under an open source licence. © 2014 Laboratoire de Biologie Moleculaire de la Cellule CNRS. Yeast published by John Wiley & Sons, Ltd.

  4. Development of instrumentation for routine ToF-SIMS imaging analysis of biological material

    NASA Astrophysics Data System (ADS)

    Cliff, B.; Lockyer, N. P.; Corlett, C.; Vickerman, J. C.

    2003-01-01

    The routine analysis of frozen-hydrated biological material is a goal that is highly sought after in the ToF-SIMS community. To this end we have developed a system based on an existing protocol developed elsewhere, but with several crucial advances. Here we report on the major design initiatives, some early performance characteristics and experimental data obtained. The system was designed with ease-of-use and reliability in mind in addition to performance, this should make the results repeatable. The device works on a freeze-fracture type method to expose pristine surface for SIMS analysis. An important performance characteristic that has emerged is one of time; the fracture stage can be cooled down to operating temperature within 30 min beginning of cooling. This is important as it minimises dead time at the beginning of an experimental session. We also present here images of freeze-fractured liposomes obtained with this hardware, showing two differing fracture regimes, we believe they are of similar quality to those obtained using other techniques.

  5. Collaborative Research. Fundamental Science of Low Temperature Plasma-Biological Material Interactions

    SciTech Connect

    Graves, David Barry; Oehrlein, Gottlieb

    2014-09-01

    atmospheric pressure using several types of low temperature plasma sources, for which radical induced interactions generally dominate due to short mean free paths of ions and VUV photons. For these conditions we demonstrated the importance of environmental interactions when atmospheric pressure plasma sources are used to modify biomolecules. This is evident from both gas phase characterization data and in-situ surface characterization of treated biomolecules. Environmental interactions can produce unexpected outcomes due to the complexity of reactions of reactive species with the atmosphere which determines the composition of reactive fluxes and atomistic changes of biomolecules. Overall, this work clarified a richer spectrum of scientific opportunities and challenges for the field of low temperature plasma-biomolecule surface interactions than initially anticipated, in particular for plasma sources operating at atmospheric pressure. The insights produced in this work, e.g. demonstration of the importance of environmental interactions, are generally important for applications of APP to materials modifications. Thus one major contributions of this research has been the establishment of methodologies to more systematically study the interaction of plasma with bio-molecules. In particular, our studies of atmospheric pressure plasma sources using very well-defined experimental conditions enabled to combine atomistic surface modifications of biomolecules with changes in their biological function. The clarification of the role of ions, VUV photons and radicals in deactivation of biomolecules during low pressure and atmospheric pressure plasma-biomolecule interaction has broad implications, e.g. for the emerging field of plasma medicine. The development of methods to detect the effects of plasma treatment on immune-active biomolecules will be helpful in many future studies.

  6. Closing the Loop: Involving Faculty in the Assessment of Scientific and Quantitative Reasoning Skills of Biology Majors

    ERIC Educational Resources Information Center

    Hurney, Carol A.; Brown, Justin; Griscom, Heather Peckham; Kancler, Erika; Wigtil, Clifton J.; Sundre, Donna

    2011-01-01

    The development of scientific and quantitative reasoning skills in undergraduates majoring in science, technology, engineering, and mathematics (STEM) is an objective of many courses and curricula. The Biology Department at James Madison University (JMU) assesses these essential skills in graduating biology majors by using a multiple-choice exam…

  7. Closing the Loop: Involving Faculty in the Assessment of Scientific and Quantitative Reasoning Skills of Biology Majors

    ERIC Educational Resources Information Center

    Hurney, Carol A.; Brown, Justin; Griscom, Heather Peckham; Kancler, Erika; Wigtil, Clifton J.; Sundre, Donna

    2011-01-01

    The development of scientific and quantitative reasoning skills in undergraduates majoring in science, technology, engineering, and mathematics (STEM) is an objective of many courses and curricula. The Biology Department at James Madison University (JMU) assesses these essential skills in graduating biology majors by using a multiple-choice exam…

  8. Micro-processing of polymers and biological materials using high repetition rate femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Ding, Li

    has been observed in or around the laser-induced refractive index modification regions. These results support the notion that femtosecond laser micro-processing method may be an excellent means of altering the refraction or higher order aberration content of corneal tissue without cell death and short-term tissue damage, and has been named as Intra-tissue Refractive Index Shaping (IRIS). The femtosecond laser micro-processing workstation has also been employed for laser transfection of single defined cells. Some preliminary results suggest that this method can be used to trace individual cells and record their biological and morphological evolution, which is quite promising in many biomedical applications especially in immunology science. In conclusion, high repetition rate femtosecond laser micro-processing has been employed to fabricate microstructures in ophthalmological hydrogels and ocular tissues. Its unique three-dimensional capability over transparent materials and biological media makes it a powerful tool and will greatly impact the future of laser material-processing.

  9. The development of peptide-based interfacial biomaterials for generating biological functionality on the surface of bioinert materials.

    PubMed

    Meyers, Steven R; Khoo, Xiaojuan; Huang, Xin; Walsh, Elisabeth B; Grinstaff, Mark W; Kenan, Daniel J

    2009-01-01

    Biomaterials used in implants have traditionally been selected based on their mechanical properties, chemical stability, and biocompatibility. However, the durability and clinical efficacy of implantable biomedical devices remain limited in part due to the absence of appropriate biological interactions at the implant interface and the lack of integration into adjacent tissues. Herein, we describe a robust peptide-based coating technology capable of modifying the surface of existing biomaterials and medical devices through the non-covalent binding of modular biofunctional peptides. These peptides contain at least one material binding sequence and at least one biologically active sequence and thus are termed, "Interfacial Biomaterials" (IFBMs). IFBMs can simultaneously bind the biomaterial surface while endowing it with desired biological functionalities at the interface between the material and biological realms. We demonstrate the capabilities of model IFBMs to convert native polystyrene, a bioinert surface, into a bioactive surface that can support a range of cell activities. We further distinguish between simple cell attachment with insufficient integrin interactions, which in some cases can adversely impact downstream biology, versus biologically appropriate adhesion, cell spreading, and cell survival mediated by IFBMs. Moreover, we show that we can use the coating technology to create spatially resolved patterns of fluorophores and cells on substrates and that these patterns retain their borders in culture.

  10. The development of peptide-based interfacial biomaterials for generating biological functionality on the surface of bioinert materials

    PubMed Central

    Meyers, Steven R.; Khoo, Xiaojuan; Huang, Xin; Walsh, Elisabeth B.; Grinstaff, Mark W.; Kenan, Daniel J.

    2013-01-01

    Biomaterials used in implants have traditionally been selected based on their mechanical properties, chemical stability, and biocompatibility. However, the durability and clinical efficacy of implantable biomedical devices remains limited in part due to the absence of appropriate biological interactions at the implant interface and the lack of integration into adjacent tissues. Herein, we describe a robust peptide-based coating technology capable of modifying the surface of existing biomaterials and medical devices through the non-covalent binding of modular biofunctional peptides. These peptides contain at least one material binding sequence and at least one biologically active sequence and thus are termed, “Interfacial Biomaterials” (IFBMs). IFBMs can simultaneously bind the biomaterial surface while endowing it with desired biological functionalities at the interface between the material and biological realms. We demonstrate the capabilities of model IFBMs to convert native polystyrene, a bioinert surface, into a bioactive surface that can support a range of cell activities. We further distinguish between simple cell attachment with insufficient integrin interactions, which in some cases can adversely impact downstream biology, versus biologically appropriate adhesion, cell spreading, and cell survival mediated by IFBMs. Moreover, we show that we can use the coating technology to create spatially resolved patterns of fluorophores and cells on substrates and that these patterns retain their borders in culture. PMID:18929406

  11. The Development of New Supplementary Teaching Materials and an Analysis of Their Potential Use in the High School Biology Curriculum.

    ERIC Educational Resources Information Center

    Duke, Reese Dale

    These materials, called "Springboards for Discussion," were designed to fit certain topics in the BSCS Blue Version textbook, "Biological Science: Molecules to Man," and to be presented by teachers using an overhead projector or magnetic audio-tapes, or both. The twelve "Springboards for Discussion" were used in first…

  12. Apollo-Soyuz pamphlet no. 9: General science. [experimental design in Astronomy, Biology, Geophysics, Aeronomy and Materials science

    NASA Technical Reports Server (NTRS)

    Page, L. W.; From, T. P.

    1977-01-01

    The objectives and planning activities for the Apollo-Soyuz mission are summarized. Aspects of the space flight considered include the docking module and launch configurations, spacecraft orbits, and weightlessness. The 28 NASA experiments conducted onboard the spacecraft are summarized. The contributions of the mission to the fields of astronomy, geoscience, biology, and materials sciences resulting from the experiments are explored.

  13. Applied Biology and Chemistry. Course Materials: Chemistry 111, 112, 113, 114. Seattle Tech Prep Applied Academics Project.

    ERIC Educational Resources Information Center

    South Seattle Community Coll., Washington.

    This publication contains materials for four courses in Applied Biology/Chemistry in the Applied Academics program at South Seattle Community College. It begins with the article, "Community College Applied Academics: The State of the Art?" (George B. Neff), which describes the characteristics, model, courses, and coordination activity…

  14. Combustion method for assay of biological materials labeled with carbon-14 or tritium, or double-labeled

    NASA Technical Reports Server (NTRS)

    Huebner, L. G.; Kisieleski, W. E.

    1969-01-01

    Dry catalytic combustion at high temperatures is used for assaying biological materials labeled carbon-14 and tritium, or double-labeled. A modified oxygen-flask technique is combined with standard vacuum-line techniques and includes convenience of direct in-vial collection of final combustion products, giving quantitative recovery of tritium and carbon-14.

  15. Improved algorithm for estimating optical properties of food and biological materials using spatially-resolved diffuse reflectance

    USDA-ARS?s Scientific Manuscript database

    In this research, the inverse algorithm for estimating optical properties of food and biological materials from spatially-resolved diffuse reflectance was optimized in terms of data smoothing, normalization and spatial region of reflectance profile for curve fitting. Monte Carlo simulation was used ...

  16. Application of a radiometric method for evaluation of loss of salicylic acid during isolation from biologic material.

    PubMed

    Ostrowski, A

    1983-01-01

    A radiometric method for evaluation of loss of salicylic acid in the process of isolation from biologic material is described. According to this study the mean loss during the total process of isolation amounts to 33.59%, the specific values being 19.47% during protein precipitation, 10.68% during extraction, and 3.44% during evaporation of solvent.

  17. Applied Biology and Chemistry. Course Materials: Chemistry 111, 112, 113, 114. Seattle Tech Prep Applied Academics Project.

    ERIC Educational Resources Information Center

    South Seattle Community Coll., Washington.

    This publication contains materials for four courses in Applied Biology/Chemistry in the Applied Academics program at South Seattle Community College. It begins with the article, "Community College Applied Academics: The State of the Art?" (George B. Neff), which describes the characteristics, model, courses, and coordination activity…

  18. Correlates of Parents' Involvement with Their Adolescent Children in Restructured and Biological Two-Parent Families: The Role of Child Characteristics

    ERIC Educational Resources Information Center

    Flouri, Eirini

    2004-01-01

    This study used data from both 225 fathers and mothers as well as their secondary school age children to explore the role of child characteristics (sex, age, self-esteem, and emotional and behavioural well-being) in mother's and father's involvement in biological and restructured (stepfather) two-parent families after controlling for known…

  19. Development and Effectiveness of an Educational Card Game as Supplementary Material in Understanding Selected Topics in Biology

    PubMed Central

    Gutierrez, Arnel F.

    2014-01-01

    The complex concepts and vocabulary of biology classes discourage many students. In this study, a pretest–posttest model was used to test the effectiveness of an educational card game in reinforcing biological concepts in comparison with traditional teaching methods. The subjects of this study were two biology classes at Bulacan State University–Sarmiento Campus. Both classes received conventional instruction; however, the experimental group's instruction was supplemented with the card game, while the control group's instruction was reinforced with traditional exercises and assignments. The score increases from pretest to posttest showed that both methods effectively reinforced biological concepts, but a t test showed that the card game is more effective than traditional teaching methods. Additionally, students from the experimental group evaluated the card game using five criteria: goals, design, organization, playability, and usefulness. The students rated the material very satisfactory. PMID:24591506

  20. Development and effectiveness of an educational card game as supplementary material in understanding selected topics in biology.

    PubMed

    Gutierrez, Arnel F

    2014-01-01

    The complex concepts and vocabulary of biology classes discourage many students. In this study, a pretest-posttest model was used to test the effectiveness of an educational card game in reinforcing biological concepts in comparison with traditional teaching methods. The subjects of this study were two biology classes at Bulacan State University-Sarmiento Campus. Both classes received conventional instruction; however, the experimental group's instruction was supplemented with the card game, while the control group's instruction was reinforced with traditional exercises and assignments. The score increases from pretest to posttest showed that both methods effectively reinforced biological concepts, but a t test showed that the card game is more effective than traditional teaching methods. Additionally, students from the experimental group evaluated the card game using five criteria: goals, design, organization, playability, and usefulness. The students rated the material very satisfactory.

  1. Thermal regulation in multiple-source arc welding involving material transformations

    SciTech Connect

    Doumanidis, C.C.

    1995-06-01

    This article addresses regulation of the thermal field generated during arc welding, as the cause of solidification, heat-affected zone and cooling rate related metallurgical transformations affecting the final microstructure and mechanical properties of various welded materials. This temperature field is described by a dynamic real-time process model, consisting of an analytical composite conduction expression for the solid region, and a lumped-state, double-stream circulation model in the weld pool, integrated with a Gaussian heat input and calibrated experimentally through butt joint GMAW tests on plain steel plates. This model serves as the basis of an in-process thermal control system employing feedback of part surface temperatures measured by infrared pyrometry; and real-time identification of the model parameters with a multivariable adaptive control strategy. Multiple heat inputs and continuous power distributions are implemented by a single time-multiplexed torch, scanning the weld surface to ensure independent, decoupled control of several thermal characteristics. Their regulation is experimentally obtained in longitudinal GTAW of stainless steel pipes, despite the presence of several geometrical, thermal and process condition disturbances of arc welding.

  2. Indium arsenide as a material for biological applications: Assessment of surface modifications, toxicity, and biocompatibility

    NASA Astrophysics Data System (ADS)

    Jewett, Scott A.

    III-V semiconductors such as InAs have recently been employed in a variety of applications where the electronic and optical characteristics of traditional, silicon-based materials are inadequate. InAs has a narrow band gap and very high electron mobility in the near-surface region, which makes it very attractive for high performance transistors, optical applications, and chemical sensing. However, InAs forms an unstable surface oxide layer in ambient conditions, which can corrode over time and leach toxic indium and arsenic components. Current research has gone into making InAs more attractive for biological applications through passivation of the surface by adlayer adsorption. In particular, wet-chemical methods are current routes of exploration due to their simplicity, low cost, and flexibility in the type of passivating molecule. This dissertation focuses on surface modifications of InAs using wet-chemical methods in order to further its use in biological applications. First, the adsorption of collagen binding peptides and mixed peptide/thiol adlayers onto InAs was assessed. X-ray photoelectron spectroscopy (XPS) along with atomic force microscopy (AFM) data suggested that the peptides successfully adsorbed onto InAs, but were only able to block oxide regrowth to a relatively low extent. This low passivation ability is due to the lack of covalent bonds of the peptide to InAs, which are necessary to effectively block oxide regrowth. The addition of a thiol, in the form of mixed peptide/thiol adlayers greatly enhanced passivation of InAs while maintaining peptide presence on the surface. Thiols form tight, covalent bonds with InAs, which prevents oxide regrowth. The presence of the collagen-binding peptide on the surface opens the door to subsequent modification with collagen or polyelectrolyte-based adlayers. Next, the stability and toxicity of modified InAs substrates were determined using inductively coupled plasma mass spectrometry (ICP-MS) and zebrafish

  3. Updated Lagrangian finite element formulations of various biological soft tissue non-linear material models: a comprehensive procedure and review.

    PubMed

    Townsend, Molly T; Sarigul-Klijn, Nesrin

    2016-01-01

    Simplified material models are commonly used in computational simulation of biological soft tissue as an approximation of the complicated material response and to minimize computational resources. However, the simulation of complex loadings, such as long-duration tissue swelling, necessitates complex models that are not easy to formulate. This paper strives to offer the updated Lagrangian formulation comprehensive procedure of various non-linear material models for the application of finite element analysis of biological soft tissues including a definition of the Cauchy stress and the spatial tangential stiffness. The relationships between water content, osmotic pressure, ionic concentration and the pore pressure stress of the tissue are discussed with the merits of these models and their applications.

  4. Removal of Exogenous Materials from the Outer Portion of Frozen Cores to Investigate the Ancient Biological Communities Harbored Inside.

    PubMed

    Barbato, Robyn A; Garcia-Reyero, Natàlia; Foley, Karen; Jones, Robert; Courville, Zoe; Douglas, Thomas; Perkins, Edward; Reynolds, Charles M

    2016-07-03

    The cryosphere offers access to preserved organisms that persisted under past environmental conditions. In fact, these frozen materials could reflect conditions over vast time periods and investigation of biological materials harbored inside could provide insight of ancient environments. To appropriately analyze these ecosystems and extract meaningful biological information from frozen soils and ice, proper collection and processing of the frozen samples is necessary. This is especially critical for microbial and DNA analyses since the communities present may be so uniquely different from modern ones. Here, a protocol is presented to successfully collect and decontaminate frozen cores. Both the absence of the colonies used to dope the outer surface and exogenous DNA suggest that we successfully decontaminated the frozen cores and that the microorganisms detected were from the material, rather than contamination from drilling or processing the cores.

  5. Enhancement in biological response of Ag-nano composite polymer membranes using plasma treatment for fabrication of efficient bio materials

    NASA Astrophysics Data System (ADS)

    Agrawal, Narendra Kumar; Sharma, Tamanna Kumari; Chauhan, Manish; Agarwal, Ravi; Vijay, Y. K.; Swami, K. C.

    2016-05-01

    Biomaterials are nonviable material used in medical devices, intended to interact with biological systems, which are becoming necessary for the development of artificial material for biological systems such as artificial skin diaphragm, valves for heart and kidney, lenses for eye etc. Polymers having novel properties like antibacterial, antimicrobial, high adhesion, blood compatibility and wettability are most suitable for synthesis of biomaterial, but all of these properties does not exist in any natural or artificial polymeric material. Nano particles and plasma treatment can offer these properties to the polymers. Hence a new nano-biomaterial has been developed by modifying the surface and chemical properties of Ag nanocomposite polymer membranes (NCPM) by Argon ion plasma treatment. These membranes were characterized using different techniques for surface and chemical modifications occurred. Bacterial adhesion and wettability were also tested for these membranes, to show direct use of this new class of nano-biomaterial for biomedical applications.

  6. An Analysis of Teaching Competence in Science Teachers Involved in the Design of Context-based Curriculum Materials

    NASA Astrophysics Data System (ADS)

    de Putter-Smits, Lesley G. A.; Taconis, Ruurd; Jochems, Wim; Van Driel, Jan

    2012-03-01

    The committees for the current Dutch context-based innovation in secondary science education employed teachers to design context-based curriculum materials. A study on the learning of science teachers in design teams for context-based curriculum materials is presented in this paper. In a correlation study, teachers with (n = 25 and 840 students) and without (n = 8 and 184 students) context-based curriculum material design experience were compared on context-based competence. Context-based competence comprises context handling, regulation, emphasis, design, and school innovation. Context-based teaching competence was mapped using both qualitative and quantitative research methods in a composite instrument. Due to the differences in design team set-up for different science subjects, teachers with design experience from different science subjects were also compared on their context-based competence. It was found that teachers with design experience showed more context-based competence than their non-designing colleagues. Furthermore, teachers designing for biology showed more context-based competence than their peers from other science subjects.

  7. Quantification of ultraviolet photon emission from interaction of charged particles in materials of interest in radiation biology research

    NASA Astrophysics Data System (ADS)

    Ahmad, Syed Bilal; McNeill, Fiona E.; Prestwich, William V.; Byun, Soo Hyun; Seymour, Colin; Mothersill, Carmel E.

    2014-01-01

    In radiation biology experiments often cells are irradiated using charged particles with the intention that only a specified number of cells are hit by the primary ion track. However, in doing so several other materials such as the cell container and the growth media etc. are also irradiated, and UV radiation emitted from these materials can potentially interact with the cells. We have hypothesized that some "bystander effects" that are thought to be chemically mediated, may be, in fact, a physical effect, where UV is interacting with non-targeted cells. Based upon our hypothesis we quantified the emission of UV from Polypropylene, Mylar, Teflon, and Cellophane which are all commonly used materials in radiation biology experiments. Additionally we measured the NIST standard materials of Oyster tissue and Citrus leaves as these powdered materials are derived from living cells. Protons accelerated up to an energy of 2.2 MeV, in a 3 MV Van de Graff accelerator, were used for irradiation. Beam current was kept to 10 nA, which corresponds to a proton fluence rate of 2.7 × 1010 protons mm-2 s-1. All the materials were found to emit light at UV frequencies and intensities that were significant enough to conduct a further investigation for their biological consequences. Mylar and polypropylene are commonly used in radiation induced bystander effect studies and are considered to be non-fluorescent. However our study showed that this is not the case. Significant luminescence observed from the irradiated NIST standard reference materials for Oyster tissue and Citrus leaves verified that the luminescence emission is not restricted only to the polymeric materials that are used to contain cells. It can also occur from ion interactions within the cells as well.

  8. Calculations of the Interactions of Energetic Ions with Materials for Protection of Computer Memory and Biological Systems

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Hee Yoon

    1995-01-01

    Theoretical calculations were performed for the propagation and interactions of particles having high atomic numbers and energy through diverse shield materials including polymeric materials and epoxy-bound lunar regolith by using transport codes for laboratory ion beams and the cosmic ray spectrum. Heavy ions fragment and lose energy upon interactions with shielding materials of specified elemental composition, density, and thickness. A fragmenting heavy iron ion produces hundreds of isotopes during nuclear reactions, which are treated in the solution of the transport problem used here. A reduced set of 80 isotopes is sufficient to represent the charge distribution, but a minimum of 122 isotopes is necessary for the mass distribution. These isotopes are adequate for ion beams with charges equal to or less than 26. To predict the single event upset (SEU) rate in electronic devices, the resultant linear energy transfer (LET) spectra from the transport code behind various materials are coupled with a measured SEU cross section versus LET curve. The SEU rate on static random access memory (SRAM) is shown as a function of shield thickness for various materials. For a given mass the most effective shields for SEU reduction are materials with high hydrogen density, such as polyethylene. The shield effectiveness for protection of biological systems is examined by using conventional quality factors to calculate the dose equivalents and also by using the probability of the neoplastic transformation of shielded C3H10T1/2 mouse cells. The attenuation of biological effects within the shield and body tissues depends on the materials properties. The results predict that hydrogenous materials are good candidates for high-performance shields. Two biological models were used. Quantitative results depended upon model.

  9. Mechanical, Biological and Electrochemical Investigations of Advanced Micro/Nano Materials for Tissue Engineering and Energy Storage

    NASA Astrophysics Data System (ADS)

    Pu, Juan

    membranes fabricated with a single drum collector. Furthermore, the bilayer PLLA scaffolds showed gradual variation in through-thickness porosity and fiber alignment and an average porosity much higher than that of conventionally electrospun scaffolds (controls) with randomly distributed fibers. The biocompatibility and biological performance of the bilayer fibrous scaffolds was evaluated by in vivo experiments involving subcutaneous scaffold implantation in Sprague-Dawley rats, followed by histology and immunohistochemistry studies. The results illustrate the potential of bilayer scaffolds to overcome major limitations of conventionally electrospun scaffolds associated with intrinsically small pores, low porosity and, consequently, poor cell infiltration. The significantly higher porosity and larger pore size of the RFL enhanced cell motility through the scaffold thickness, whereas the relatively dense structure of the AFL provided adequate mechanical strength. The bilayer scaffolds showed more than two times higher cell infiltration than controls during implantation in vivo. Moreover, the unique structure of bilayer scaffolds promoted collagen fiber deposition, cell proliferation, and ingrowth of smooth muscle cells and endothelial cells in vivo.. Novel all-solid-state microsupercapacitors (MSCs) with 3D electrodes consisting of active materials and a polymer electrolyte (PE) designed for high-energy-density storage applications were fabricated and tested. The incorporation of a PE in the electrode material enhanced the accessibility of the surface of active materials by electrolyte ions and decreased the ion diffusion path during electrochemical charging/discharging. For a scan rate of 5 mV s -1, the MSCs with graphene/PE and AC/PE composite electrodes demonstrated a very high areal capacitance of 95 and 134 mF cm-2 , respectively, comparable with that of 3D MSCs having a liquid electrolyte. In addition, the graphene/PE MSCs showed 70% increase in specific capacitance

  10. THE NGA-DOE GRANT TO EXAMINE CRITICAL ISSUES RELATED TO RADIOACTIVE WASTE AND MATERIALS DISPOSITION INVOLVING DOE FACILITIES

    SciTech Connect

    Ann M. Beauchesne

    1999-01-31

    Through the National Governors' Association (NGA) project ''Critical Issues Related to Radioactive Waste and Materials Disposition Involving DOE Facilities'' NGA brings together Governors' policy advisors, state regulators, and DOE officials to examine critical issues related to the cleanup and operation of DOE nuclear weapons and research facilities. Topics explored through this project include: (1) Decisions involving disposal of mixed, low-level, and transuranic (TRU) waste and disposition of nuclear materials; (2) Decisions involving DOE budget requests and their effect on environmental cleanup and compliance at DOE facilities; (3) Strategies to treat mixed, low-level, and transuranic (TRU) waste and their effect on individual sites in the complex; (4) Changes to the FFCA site treatment plans as a result of proposals in the Department's Accelerating Cleanup: Paths to Closure plan and contractor integration analysis; (5) Interstate waste and materials shipments; and (6) Reforms to existing RCRA and CERCLA regulations/guidance to address regulatory overlap and risks posed by DOE wastes. The overarching theme of this project is to help the Department improve coordination of its major program decisions with Governors' offices and state regulators and to ensure such decisions reflect input from these key state officials and stakeholders. This report summarizes activities conducted during the quarter from October 1, 1998 through January 31, 1999, under the NGA grant. The work accomplished by the NGA project team during the past four months can be categorized as follows: (1) maintained open communication with DOE on a variety of activities and issues within the DOE environmental management complex; (2) maintained communication with NGA Federal Facilities Compliance Task Force members regarding DOE efforts to formulate a configuration for mixed low-level waste and low-level treatment and disposal, external regulation of DOE; and EM Integration activities; and (3

  11. THE NGA-DOE GRANT TO EXAMINE CRITICAL ISSUES RELATED TO RADIOACTIVE WASTE AND MATERIALS DISPOSITION INVOLVING DOE FACILITIES

    SciTech Connect

    Ann B. Beauchesne

    1998-09-30

    Through the National Governors' Association (NGA) project ''Critical Issues Related to Radioactive Waste and Materials Disposition Involving DOE Facilities'' NGA brings together Governors' policy advisors, state regulators, and DOE officials to examine critical issues related to the cleanup and operation of DOE nuclear weapons and research facilities. Topics explored through this project include: (1) Decisions involving disposal of mixed, low-level, and transuranic (TRU) waste and disposition of nuclear materials; (2) Decisions involving DOE budget requests and their effect on environmental cleanup and compliance at DOE facilities; (3) Strategies to treat mixed, low-level, and transuranic (TRU) waste and their effect on individual sites in the complex; (4) Changes to the FFCA site treatment plans as a result of proposals in the Department's Accelerating Cleanup: Paths to Closure plan and contractor integration analysis; (5) Interstate waste and materials shipments; and (6) Reforms to existing RCRA and CERCLA regulations/guidance to address regulatory overlap and risks posed by DOE wastes. The overarching theme of this project is to help the Department improve coordination of its major program decisions with Governors' offices and state regulators and to ensure such decisions reflect input from these key state officials and stakeholders. This report summarizes activities conducted during the quarter from June 1, 1998 through September 30, 1998, under the NGA grant. The work accomplished by the NGA project team during the past four months can be categorized as follows: (1) maintained open communication with DOE on a variety of activities and issues within the DOE environmental management complex; (2) maintained communication with NGA Federal Facilities Compliance Task Force members regarding DOE efforts to formulate a configuration for mixed low-level waste and low-level treatment and disposal, external regulation of DOE; and EM Integration activities; and (3

  12. Chemically-functionalized microcantilevers for detection of chemical, biological and explosive material

    SciTech Connect

    Pinnaduwage, Lal A; Thundat, Thomas G; Brown, Gilbert M; Hawk, John Eric; Boiadjiev, Vassil I

    2007-04-24

    A chemically functionalized cantilever system has a cantilever coated on one side thereof with a reagent or biological species which binds to an analyte. The system is of particular value when the analyte is a toxic chemical biological warfare agent or an explosive.

  13. EDITORIAL: Nanotechnology at the interface of cell biology, materials science and medicine Nanotechnology at the interface of cell biology, materials science and medicine

    NASA Astrophysics Data System (ADS)

    Engel, Andreas; Miles, Mervyn

    2008-09-01

    The atomic force microscope (AFM) and related scanning probe microscopes have become resourceful tools to study cells, supramolecular assemblies and single biomolecules, because they allow investigations of such structures in native environments. Quantitative information has been gathered about the surface structure of membrane proteins to lateral and vertical resolutions of 0.5 nm and 0.1 nm, respectively, about the forces that keep protein-protein and protein-nucleic acid assemblies together as well as single proteins in their native conformation, and about the nanomechanical properties of cells in health and disease. Such progress has been achieved mainly because of constant development of AFM instrumentation and sample preparation methods. This special issue of Nanotechnology presents papers from leading laboratories in the field of nanobiology, covering a wide range of topics in the form of original and novel scientific contributions. It addresses achievements in instrumentation, sample preparation, automation and in biological applications. These papers document the creativity and persistence of researchers pursuing the goal to unravel the structure and dynamics of cells, supramolecuar structures and single biomolecules at work. Improved cantilever sensors, novel optical probes, and quantitative data on supports for electrochemical experiments open new avenues for characterizing biological nanomachines down to the single molecule. Comparative measurements of healthy and metastatic cells promise new methods for early detection of tumors, and possible assessments of drug efficacy. High-speed AFMs document possibilities to monitor crystal growth and to observe large structures at video rate. A wealth of information on amyloid-type fibers as well as on membrane proteins has been gathered by single molecule force spectroscopy—a technology now being automated for large-scale data collection. With the progress of basic research and a strong industry supporting

  14. Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report

    SciTech Connect

    Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

    2012-07-25

    This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOE’s research

  15. The protein and peptide mediated syntheses of non-biologically-produced oxide materials

    NASA Astrophysics Data System (ADS)

    Dickerson, Matthew B.

    Numerous examples exist in nature of organisms which have evolved the ability to produce sophisticated structures composed of inorganic minerals. Studies of such biomineralizing organisms have suggested that specialized biomolecules are, in part, responsible for the controlled formation of these structures. The research detailed in this dissertation is focused on the use of biomolecules (i.e., peptides and proteins) to form non-biologically produced materials under mild reaction conditions (i.e., neutral pH, aqueous solutions, and room temperature). The peptides utilized in the studies detailed in this dissertation were identified through the screening of single crystal rutile TiO2 substrates or Ge powder with a phagedisplayed peptide library. Twenty-one peptides were identified which possessed an affinity for Ge. Three of these twenty one peptides were tested for germania precipitation activity. Those peptides possessing a basic isoelectric point as well as hydroxyl- and imidazole-containing amino acid residues were found to be the most effective in precipitating amorphous germania from an alkoxide precursor. The phage-displayed peptide library screening of TiO2 substrates yielded twenty peptides. Four of these peptides, which were heavily enriched in histidine and/or basic amino acid residues, were found to possess signficant titania precipitation activity. The activity of these peptides was found to correlate with the number of positive charges they carried. The sequence of the most active of the library-identified peptides was modified to yield two additional peptides. The titania precipitation activity of these designed peptides was higher than the parent peptide, with reduced pH dependence. The titania materials generated by the library-identified and designed peptides were found to be composed of amorphous titania as well as <10 nm anatase and/or monoclinic TiO2 crystallites. The production of titania and zirconia resulting from the interaction of the

  16. Investigation on thiosulfate-involved organics and nitrogen removal by a sulfur cycle-based biological wastewater treatment process.

    PubMed

    Qian, Jin; Lu, Hui; Cui, Yanxiang; Wei, Li; Liu, Rulong; Chen, Guang-Hao

    2015-02-01

    Thiosulfate, as an intermediate of biological sulfate/sulfite reduction, can significantly improve nitrogen removal potential in a biological sulfur cycle-based process, namely the Sulfate reduction-Autotrophic denitrification-Nitrification Integrated (SANI(®)) process. However, the related thiosulfate bio-activities coupled with organics and nitrogen removal in wastewater treatment lacked detailed examinations and reports. In this study, S2O3(2-) transformation during biological SO4(2-)/SO3(2-) co-reduction coupled with organics removal as well as S2O3(2-) oxidation coupled with chemolithotrophic denitrification were extensively evaluated under different experimental conditions. Thiosulfate is produced from the co-reduction of sulfate and sulfite through biological pathway at an optimum pH of 7.5 for organics removal. And the produced S2O3(2-) may disproportionate to sulfide and sulfate during both biological S2O3(2-) reduction and oxidation most possibly carried out by Desulfovibrio-like species. Dosing the same amount of nitrate, pH was found to be the more direct factor influencing the denitritation activity than free nitrous acid (FNA) and the optimal pH for denitratation (7.0) and denitritation (8.0) activities were different. Spiking organics significantly improved both denitratation and denitritation activities while minimizing sulfide inhibition of NO3(-) reduction during thiosulfate-based denitrification. These findings in this study can improve the understanding of mechanisms of thiosulfate on organics and nitrogen removal in biological sulfur cycle-based wastewater treatment.

  17. Designing Laboratory Exercises for the Undergraduate Molecular Biology/Biochemistry Student: Techniques and Ethical Implications Involved in Personalized Medicine

    ERIC Educational Resources Information Center

    Weinlander, Kenneth M.; Hall, David J.

    2010-01-01

    Personalized medicine refers to medical care that involves genetically screening patients for their likelihood to develop various disorders. Commercial genome screening only involves identifying a consumer's genotype for a few single nucleotide polymorphisms. A phenotype (such as an illness) is greatly influenced by three factors: genes, gene…

  18. Designing Laboratory Exercises for the Undergraduate Molecular Biology/Biochemistry Student: Techniques and Ethical Implications Involved in Personalized Medicine

    ERIC Educational Resources Information Center

    Weinlander, Kenneth M.; Hall, David J.

    2010-01-01

    Personalized medicine refers to medical care that involves genetically screening patients for their likelihood to develop various disorders. Commercial genome screening only involves identifying a consumer's genotype for a few single nucleotide polymorphisms. A phenotype (such as an illness) is greatly influenced by three factors: genes, gene…

  19. A streptavidin-metallothionein chimera that allows specific labeling of biological materials with many different heavy metal ions.

    PubMed Central

    Sano, T; Glazer, A N; Cantor, C R

    1992-01-01

    We have designed a streptavidin-metallothionein chimeric protein in which the streptavidin moiety provides a means of binding the metallothionein moiety tightly to specific biological targets. A gene fusion of streptavidin with mouse metallothionein I was efficiently expressed in Escherichia coli, and the expressed chimeric protein was purified to homogeneity by a simple procedure. The purified chimera, consisting of four identical subunits, bound one biotin and approximately seven Cd2+ ions per subunit (19.5 kDa). This indicates that both the streptavidin and the metallothionein moieties are fully functional. The high binding affinity of the chimera both for biotin and for heavy metal ions allows the specific labeling or conjugation of any biological material containing unhindered biotin with a variety of different heavy metal ions and their isotopes, thereby opening the way for simultaneous assay systems for a large number of biological targets. Images PMID:1542645

  20. The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials.

    PubMed

    Mulware, Stephen Juma

    2015-01-01

    The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented.

  1. DOE Partnerships with States, Tribes and Other Federal Programs Help Responders Prepare for Challenges Involving Transport of Radioactive Materials

    SciTech Connect

    Marsha Keister

    2001-02-01

    DOE Partnerships with States, Tribes and Other Federal Programs Help Responders Prepare for Challenges Involving Transport of Radioactive Materials Implementing adequate institutional programs and validating preparedness for emergency response to radiological transportation incidents along or near U.S. Department of Energy (DOE) shipping corridors poses unique challenges to transportation operations management. Delayed or insufficient attention to State and Tribal preparedness needs may significantly impact the transportation operations schedule and budget. The DOE Transportation Emergency Preparedness Program (TEPP) has successfully used a cooperative planning process to develop strong partnerships with States, Tribes, Federal agencies and other national programs to support responder preparedness across the United States. DOE TEPP has found that building solid partnerships with key emergency response agencies ensures responders have access to the planning, training, technical expertise and assistance necessary to safely, efficiently and effectively respond to a radiological transportation accident. Through the efforts of TEPP over the past fifteen years, partnerships have resulted in States and Tribal Nations either using significant portions of the TEPP planning resources in their programs and/or adopting the Modular Emergency Response Radiological Transportation Training (MERRTT) program into their hazardous material training curriculums to prepare their fire departments, law enforcement, hazardous materials response teams, emergency management officials, public information officers and emergency medical technicians for responding to transportation incidents involving radioactive materials. In addition, through strong partnerships with Federal Agencies and other national programs TEPP provided technical expertise to support a variety of radiological response initiatives and assisted several programs with integration of the nationally recognized MERRTT program

  2. The use of an ion-beam source to alter the surface morphology of biological implant materials

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.

    1978-01-01

    An electron bombardment, ion thruster was used as a neutralized-ion beam sputtering source to texture the surfaces of biological implant materials. Scanning electron microscopy was used to determine surface morphology changes of all materials after ion-texturing. Electron spectroscopy for chemical analysis was used to determine the effects of ion texturing on the surface chemical composition of some polymers. Liquid contact angle data were obtained for ion textured and untextured polymer samples. Results of tensile and fatigue tests of ion-textured metal alloys are presented. Preliminary data of tissue response to ion textured surfaces of some metals, polytetrafluoroethylene, alumina, and segmented polyurethane were obtained.

  3. Development of the technology of designing of nanocomposite materials based on fluorocontaining synthetic latex and biologically active polysaccharides

    NASA Astrophysics Data System (ADS)

    Davydova, G. A.; Selezneva, I. I.; Knot'ko, A. V.; Savintseva, I. V.; Montrel, M. M.; Gavrilyuk, B. K.

    2008-03-01

    A conceptually novel approach to the formation of composite biosynthetic materials is proposed, which is based on the phenomenon of self-organization of ensembles of nanoparticles of synthetic latex and biologically active polysaccharides into three-dimensional structures. It is shown that, by varying the polysaccharide/latex ratio, the nature of polysaccharide, and the temperature of drying of colloidal suspension, it is possible to control the architecture of ensembles of nanoparticles and the physicochemical characteristics of biosynthetic materials formed on their basis.

  4. Investigation of biological activity of fine fraction of lunar surface material returned to earth by the Luna 16 automatic station

    NASA Technical Reports Server (NTRS)

    Kustov, V. V.; Ostapenko, O. F.; Petrukhin, V. G.

    1974-01-01

    The biological action of a sample of lunar surface material returned to earth by the Luna 16 automatic station from a new region of the mare surface on male white mice was studied. The condition and behavior of the animals were observed; the intensity of their oxygen consumption was recorded, and motor activity of the muscles, leucocyte and erythrocytes counts in the peripheral blood, and the activity of whole blood chloinesterase were determined. Experimental results showed that the tested doses of the fine fraction of the lunar surface material from the Sea of Fertility were virtually innocuous for white mice.

  5. Protein viscosity, mineral fraction and staggered architecture cooperatively enable the fastest stress wave decay in load-bearing biological materials.

    PubMed

    Qwamizadeh, Mahan; Zhang, Zuoqi; Zhou, Kun; Zhang, Yong Wei

    2016-07-01

    One of the key functions of load-bearing biological materials, such as bone, dentin and sea shell, is to protect their inside fragile organs by effectively damping dynamic impact. How those materials achieve this remarkable function remains largely unknown. Using systematic finite element analyses, we study the stress wave propagation and attenuation in cortical bone at the nanoscale as a model material to examine the effects of protein viscosity, mineral fraction and staggered architecture on the elastic wave decay. It is found that the staggered arrangement, protein viscosity and mineral fraction work cooperatively to effectively attenuate the stress wave. For a typical mineral volume fraction and protein viscosity, an optimal staggered nanostructure with specific feature sizes and layouts is able to give rise to the fastest stress wave decay, and the optimal aspect ratio and thickness of mineral platelets are in excellent agreement with experimental measurements. In contrary, as the mineral volume fraction or the protein viscosity goes much higher, the structural arrangement is seen having trivial effect on the stress wave decay, suggesting that the damping properties of the composites go into the structure-insensitive regime from the structure-sensitive regime. These findings not only significantly add to our understanding of the structure-function relationship of load-bearing biological materials, and but also provide useful guidelines for the design of bio-inspired materials with superior resistance to impact loading.

  6. [Peculiarities of chemico-toxicological analysis of biological material aimed to detection of narcotic and psychoactive substances misuse by servicemen].

    PubMed

    Pinchuk, P V; Kirichek, A V; Shabalina, A E; Smirnov, A V; Petukhov, A E

    2016-02-01

    The authors give an approval of military personnel biosphere research, which is necessary for prevention and early detection of substance misuse among military personnel of the Armed Forces. The article provides documents, regulating procedure of the chemico-toxicological analysis of a biological material, and staging of early detection of substance misuse among conscripts and professional soldiers. The authors gave information about main current problems of this activity, revealed its disadvantages and detected prevention measures.

  7. Free radicals: how do we stand them? Anaerobic and aerobic free radical (chain) reactions involved in the use of fluorogenic probes and in biological systems.

    PubMed

    Liochev, Stefan I

    2014-01-01

    Biologically significant conclusions have been based on the use of fluorogenic and luminogenic probes for the detection of reactive species. The basic mechanisms of the processes involved have not been satisfactorily elucidated. In the present work, the mechanism of the enzyme and photosensitized oxidation of NAD(P)H by resorufin is analyzed and appears to involve both aerobic and anaerobic free radical chain reactions. There are two major fallouts of this analysis. Many of the conclusions about the participation of radicals based on the use of probes such as resorufin and Amplex red need reevaluation. It is also concluded that anaerobic free radical reactions may be biologically significant, and the possible existence of enzymatic systems to eliminate certain free radicals is discussed.

  8. Protective Behaviour of Citizens to Transport Accidents Involving Hazardous Materials: A Discrete Choice Experiment Applied to Populated Areas nearby Waterways.

    PubMed

    de Bekker-Grob, Esther W; Bergstra, Arnold D; Bliemer, Michiel C J; Trijssenaar-Buhre, Inge J M; Burdorf, Alex

    2015-01-01

    To improve the information for and preparation of citizens at risk to hazardous material transport accidents, a first important step is to determine how different characteristics of hazardous material transport accidents will influence citizens' protective behaviour. However, quantitative studies investigating citizens' protective behaviour in case of hazardous material transport accidents are scarce. A discrete choice experiment was conducted among subjects (19-64 years) living in the direct vicinity of a large waterway. Scenarios were described by three transport accident characteristics: odour perception, smoke/vapour perception, and the proportion of people in the environment that were leaving at their own discretion. Subjects were asked to consider each scenario as realistic and to choose the alternative that was most appealing to them: staying, seeking shelter, or escaping. A panel error component model was used to quantify how different transport accident characteristics influenced subjects' protective behaviour. The response was 44% (881/1,994). The predicted probability that a subject would stay ranged from 1% in case of a severe looking accident till 62% in case of a mild looking accident. All three transport accident characteristics proved to influence protective behaviour. Particularly a perception of strong ammonia or mercaptan odours and visible smoke/vapour close to citizens had the strongest positive influence on escaping. In general, 'escaping' was more preferred than 'seeking shelter', although stated preference heterogeneity among subjects for these protective behaviour options was substantial. Males were less willing to seek shelter than females, whereas elderly people were more willing to escape than younger people. Various characteristics of transport accident involving hazardous materials influence subjects' protective behaviour. The preference heterogeneity shows that information needs to be targeted differently depending on gender and age

  9. Protective Behaviour of Citizens to Transport Accidents Involving Hazardous Materials: A Discrete Choice Experiment Applied to Populated Areas nearby Waterways

    PubMed Central

    de Bekker-Grob, Esther W.; Bergstra, Arnold D.; Bliemer, Michiel C. J.; Trijssenaar-Buhre, Inge J. M.; Burdorf, Alex

    2015-01-01

    Background To improve the information for and preparation of citizens at risk to hazardous material transport accidents, a first important step is to determine how different characteristics of hazardous material transport accidents will influence citizens’ protective behaviour. However, quantitative studies investigating citizens’ protective behaviour in case of hazardous material transport accidents are scarce. Methods A discrete choice experiment was conducted among subjects (19–64 years) living in the direct vicinity of a large waterway. Scenarios were described by three transport accident characteristics: odour perception, smoke/vapour perception, and the proportion of people in the environment that were leaving at their own discretion. Subjects were asked to consider each scenario as realistic and to choose the alternative that was most appealing to them: staying, seeking shelter, or escaping. A panel error component model was used to quantify how different transport accident characteristics influenced subjects’ protective behaviour. Results The response was 44% (881/1,994). The predicted probability that a subject would stay ranged from 1% in case of a severe looking accident till 62% in case of a mild looking accident. All three transport accident characteristics proved to influence protective behaviour. Particularly a perception of strong ammonia or mercaptan odours and visible smoke/vapour close to citizens had the strongest positive influence on escaping. In general, ‘escaping’ was more preferred than ‘seeking shelter’, although stated preference heterogeneity among subjects for these protective behaviour options was substantial. Males were less willing to seek shelter than females, whereas elderly people were more willing to escape than younger people. Conclusion Various characteristics of transport accident involving hazardous materials influence subjects’ protective behaviour. The preference heterogeneity shows that information needs

  10. Structural biology of disease-associated repetitive DNA sequences and protein-DNA complexes involved in DNA damage and repair

    SciTech Connect

    Gupta, G.; Santhana Mariappan, S.V.; Chen, X.; Catasti, P.; Silks, L.A. III; Moyzis, R.K.; Bradbury, E.M.; Garcia, A.E.

    1997-07-01

    This project is aimed at formulating the sequence-structure-function correlations of various microsatellites in the human (and other eukaryotic) genomes. Here the authors have been able to develop and apply structure biology tools to understand the following: the molecular mechanism of length polymorphism microsatellites; the molecular mechanism by which the microsatellites in the noncoding regions alter the regulation of the associated gene; and finally, the molecular mechanism by which the expansion of these microsatellites impairs gene expression and causes the disease. Their multidisciplinary structural biology approach is quantitative and can be applied to all coding and noncoding DNA sequences associated with any gene. Both NIH and DOE are interested in developing quantitative tools for understanding the function of various human genes for prevention against diseases caused by genetic and environmental effects.

  11. Global Analysis of Lysine Acetylation Suggests the Involvement of Protein Acetylation in Diverse Biological Processes in Rice (Oryza sativa)

    PubMed Central

    Zhong, Xiaoxian; Tan, Feng; Mujahid, Hana; Zhang, Jian; Nanduri, Bindu; Peng, Zhaohua

    2014-01-01

    Lysine acetylation is a reversible, dynamic protein modification regulated by lysine acetyltransferases and deacetylases. Recent advances in high-throughput proteomics have greatly contributed to the success of global analysis of lysine acetylation. A large number of proteins of diverse biological functions have been shown to be acetylated in several reports in human cells, E.coli, and dicot plants. However, the extent of lysine acetylation in non-histone proteins remains largely unknown in monocots, particularly in the cereal crops. Here we report the mass spectrometric examination of lysine acetylation in rice (Oryza sativa). We identified 60 lysine acetylated sites on 44 proteins of diverse biological functions. Immunoblot studies further validated the presence of a large number of acetylated non-histone proteins. Examination of the amino acid composition revealed substantial amino acid bias around the acetylation sites and the amino acid preference is conserved among different organisms. Gene ontology analysis demonstrates that lysine acetylation occurs in diverse cytoplasmic, chloroplast and mitochondrial proteins in addition to the histone modifications. Our results suggest that lysine acetylation might constitute a regulatory mechanism for many proteins, including both histones and non-histone proteins of diverse biological functions. PMID:24586658

  12. Global analysis of lysine acetylation suggests the involvement of protein acetylation in diverse biological processes in rice (Oryza sativa).

    PubMed

    Nallamilli, Babi Ramesh Reddy; Edelmann, Mariola J; Zhong, Xiaoxian; Tan, Feng; Mujahid, Hana; Zhang, Jian; Nanduri, Bindu; Peng, Zhaohua

    2014-01-01

    Lysine acetylation is a reversible, dynamic protein modification regulated by lysine acetyltransferases and deacetylases. Recent advances in high-throughput proteomics have greatly contributed to the success of global analysis of lysine acetylation. A large number of proteins of diverse biological functions have been shown to be acetylated in several reports in human cells, E.coli, and dicot plants. However, the extent of lysine acetylation in non-histone proteins remains largely unknown in monocots, particularly in the cereal crops. Here we report the mass spectrometric examination of lysine acetylation in rice (Oryza sativa). We identified 60 lysine acetylated sites on 44 proteins of diverse biological functions. Immunoblot studies further validated the presence of a large number of acetylated non-histone proteins. Examination of the amino acid composition revealed substantial amino acid bias around the acetylation sites and the amino acid preference is conserved among different organisms. Gene ontology analysis demonstrates that lysine acetylation occurs in diverse cytoplasmic, chloroplast and mitochondrial proteins in addition to the histone modifications. Our results suggest that lysine acetylation might constitute a regulatory mechanism for many proteins, including both histones and non-histone proteins of diverse biological functions.

  13. Whole genome association study identifies regions of the bovine genome and biological pathways involved in carcass trait performance in Holstein-Friesian cattle.

    PubMed

    Doran, Anthony G; Berry, Donagh P; Creevey, Christopher J

    2014-10-01

    Four traits related to carcass performance have been identified as economically important in beef production: carcass weight, carcass fat, carcass conformation of progeny and cull cow carcass weight. Although Holstein-Friesian cattle are primarily utilized for milk production, they are also an important source of meat for beef production and export. Because of this, there is great interest in understanding the underlying genomic structure influencing these traits. Several genome-wide association studies have identified regions of the bovine genome associated with growth or carcass traits, however, little is known about the mechanisms or underlying biological pathways involved. This study aims to detect regions of the bovine genome associated with carcass performance traits (employing a panel of 54,001 SNPs) using measures of genetic merit (as predicted transmitting abilities) for 5,705 Irish Holstein-Friesian animals. Candidate genes and biological pathways were then identified for each trait under investigation. Following adjustment for false discovery (q-value < 0.05), 479 quantitative trait loci (QTL) were associated with at least one of the four carcass traits using a single SNP regression approach. Using a Bayesian approach, 46 QTL were associated (posterior probability > 0.5) with at least one of the four traits. In total, 557 unique bovine genes, which mapped to 426 human orthologs, were within 500kbs of QTL found associated with a trait using the Bayesian approach. Using this information, 24 significantly over-represented pathways were identified across all traits. The most significantly over-represented biological pathway was the peroxisome proliferator-activated receptor (PPAR) signaling pathway. A large number of genomic regions putatively associated with bovine carcass traits were detected using two different statistical approaches. Notably, several significant associations were detected in close proximity to genes with a known role in animal growth

  14. Biological properties of IRM with the addition of hydroxyapatite as a retrograde root filling material.

    PubMed

    Owadally, I D; Chong, B S; Pitt Ford, T R; Wilson, R F

    1994-10-01

    The effect of adding 10% & 20% hydroxyapatite (HAP) on the antibacterial activity and cytotoxicity of IRM (Intermediate Restorative Material) when used as a retrograde root filling was compared with amalgam, a commonly used material. The antibacterial activity was assessed using the agar diffusion inhibitory test. Forty standardized pellets of each material were produced. Fresh materials, and materials aged for 1 week in sterile distilled water, were placed on blood agar plates inoculated with Streptococcus anginosus (milleri) or Enterococcus faecalis. The presence and diameter of zones of inhibition were recorded at intervals of 3, 7 and 10 days. There was no statistically significant overall difference in the response of the two bacteria tested. However, there were statistically significant overall differences in diameters of the zones of inhibition related to different materials, period of exposure and ageing of materials (P < 0.001). The diameter of the zones of inhibition increased with time for all materials, fresh and aged. IRM and both the HAP-modified forms produced large zones of inhibition. Amalgam produced no measureable zones of inhibition whether aged or fresh, regardless of period of exposure and was different from the other materials (P < 0.001). The cytotoxicity was assessed using the Millipore filter method. Ten standardized pellets of each material were produced and aged by storage in sterile distilled water for 72 h. Ten filters were included as controls. Amalgam produced a consistent cytotoxic score of 1, and the difference between amalgam and the other materials was statistically significant (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Determination of Perfluorinated Alkyl Acid Concentrations in Biological Standard Reference Materials

    EPA Science Inventory

    Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned ...

  16. Wood-derived materials for green electronics, biological Devices, and energy applications

    Treesearch

    Hongli Zhu; Wei Luo; Peter N. Ciesielski; Zhiqiang Fang; Junyong Zhu; Gunnar Henriksson; Michael E. Himmel; Liangbing Hu

    2016-01-01

    With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example,...

  17. Determination of Perfluorinated Alkyl Acid Concentrations in Biological Standard Reference Materials

    EPA Science Inventory

    Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned ...

  18. Biological effects of emissions from resistance spot welding of zinc-coated material after controlled exposure of healthy human subjects.

    PubMed

    Gube, Monika; Kraus, Thomas; Lenz, Klaus; Reisgen, Uwe; Brand, Peter

    2014-06-01

    Do emissions from a resistance spot welding process of zinc-coated materials induce systemic inflammation in healthy subjects after exposure for 6 hours? Twelve healthy male subjects were exposed once for 6 hours either to filtered ambient air or to welding fume from resistance spot welding of zinc-coated material (mass concentration approximately 100 μg m). Biological effects were measured before, after, and 24 hours after exposure. At the concentrations used in this study, however, the suspected properties of ultrafine particles did not lead to systemic inflammation as reflected by high-sensitivity C-reactive protein or other endpoint parameters under consideration. Ultrafine particles from a resistance spot welding process of zinc-covered materials with a number concentration of about 10 cm and a mass concentration of about 100 μg m did not induce systemic inflammation.

  19. The use of an ion-beam source to alter the surface morphology of biological implant materials

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.

    1978-01-01

    An electron-bombardment ion-thruster was used as a neutralized-ion-beam sputtering source to texture the surfaces of biological implant materials. The materials investigated included 316 stainless steel; titanium-6% aluminum, 4% vanadium; cobalt-20% chromium, 15% tungsten; cobalt-35% nickel, 20% chromium, 10% molybdenum; polytetrafluoroethylene; polyoxymethylene; silicone and polyurethane copolymer; 32%-carbon-impregnated polyolefin; segmented polyurethane; silicone rubber; and alumina. Scanning electron microscopy was used to determine surface morphology changes of all materials after ion-texturing. Electron spectroscopy for chemical analysis was used to determine the effects of ion-texturing on the surface chemical composition of some polymers. Liquid contact angle data were obtained for ion-textured and untextured polymer samples. Results of tensile and fatigue tests of ion-textured metal alloys are presented. Preliminary data of tissue response to ion-textured surfaces of some metals, polytetrafluoroethylene, alumina, and segmented polyurethane have been obtained.

  20. The use of an ion-beam source to alter the surface morphology of biological implant materials

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.

    1978-01-01

    An electron-bombardment ion-thruster was used as a neutralized-ion-beam sputtering source to texture the surfaces of biological implant materials. The materials investigated included 316 stainless steel; titanium-6% aluminum, 4% vanadium; cobalt-20% chromium, 15% tungsten; cobalt-35% nickel, 20% chromium, 10% molybdenum; polytetrafluoroethylene; polyoxymethylene; silicone and polyurethane copolymer; 32%-carbon-impregnated polyolefin; segmented polyurethane; silicone rubber; and alumina. Scanning electron microscopy was used to determine surface morphology changes of all materials after ion-texturing. Electron spectroscopy for chemical analysis was used to determine the effects of ion-texturing on the surface chemical composition of some polymers. Liquid contact angle data were obtained for ion-textured and untextured polymer samples. Results of tensile and fatigue tests of ion-textured metal alloys are presented. Preliminary data of tissue response to ion-textured surfaces of some metals, polytetrafluoroethylene, alumina, and segmented polyurethane have been obtained.

  1. Development and applications of photosensitive device systems to studies of biological and organic materials. Progress report

    SciTech Connect

    Not Available

    1984-01-01

    The purpose was to develop and improve appropriate experimental techniques to the point where they could be applied to specific classes of biological problems. Progress is reported in the following areas: (1) area detectors; (2) x-ray diffraction studies of membranes; (3) electron transfer in loosely coupled systems; (4) bioluminescence and fluorescence; and (5) sonoluminescence. (ACR)

  2. Digital Learning Material for Student-Directed Model Building in Molecular Biology

    ERIC Educational Resources Information Center

    Aegerter-Wilmsen, Tinri; Coppens, Marjolijn; Janssen, Fred; Hartog, Rob; Bisseling, Ton

    2005-01-01

    The building of models to explain data and make predictions constitutes an important goal in molecular biology research. To give students the opportunity to practice such model building, two digital cases had previously been developed in which students are guided to build a model step by step. In this article, the development and initial…

  3. A Comparison of Decontamination Technologies for Biological Agents on Selected Commercial Surface Materials

    DTIC Science & Technology

    2001-04-01

    The University of Michigan, Center for Biological Nanotechnology has developed a novel broad-spectrum antimicrobial nanoemulsion . The emulsions kill...disintegration. This process starts in about 30 minutes and the complete killing will be achieved in 2-3 hours. The nanoemulsions are non-irritant

  4. Digital Learning Material for Student-Directed Model Building in Molecular Biology

    ERIC Educational Resources Information Center

    Aegerter-Wilmsen, Tinri; Coppens, Marjolijn; Janssen, Fred; Hartog, Rob; Bisseling, Ton

    2005-01-01

    The building of models to explain data and make predictions constitutes an important goal in molecular biology research. To give students the opportunity to practice such model building, two digital cases had previously been developed in which students are guided to build a model step by step. In this article, the development and initial…

  5. Paramagnetic 3d coordination complexes involving redox-active tetrathiafulvalene derivatives: an efficient approach to elaborate multi-properties materials.

    PubMed

    Pointillart, Fabrice; Golhen, Stéphane; Cador, Olivier; Ouahab, Lahcène

    2013-02-14

    The elaboration of multifunctional materials is a great challenge for the physical chemistry community and the studies of molecular materials exhibiting coexistence or synergy between two or more properties are very active. In particular, molecular compounds displaying electrical conductivity and magnetic interactions are currently the subject of intensive studies. Two approaches are now well-known and are explored. On the one hand, the interactions between mobile electrons of the organic network (π electrons) and localized electrons of paramagnetic transition metal (d electrons) take place through space. On the other hand, these interactions take place through covalent chemical bonds. In the latter, the probability to have significant interaction between π and d electrons is enhanced compared to the first approach. In this perspective article, we will give an overview of the known coordination complexes involving tetrathiafulvalene derivatives as ligands for paramagnetic 3d ions and we will describe their physical properties. If necessary, the coexistence or synergy between electrical conductivity, magnetism and other properties will be highlighted.

  6. Critical assessment of the performance of electronic moisture analyzers for small amounts of environmental samples and biological reference materials.

    PubMed

    Krachler, M

    2001-12-01

    Two electronic moisture analyzers were critically evaluated with regard to their suitability for determining moisture in small amounts (< or = 200 mg) of various environmental matrices such as leaves, needles, soil, peat, sediments, and sewage sludge, as well as various biological reference materials. To this end, several homogeneous bulk materials were prepared which were subsequently employed for the development and optimization of all analytical procedures. The key features of the moisture analyzers included a halogen or ceramic heater and an integrated balance with a resolution of 0.1 mg, which is an essential prerequisite for obtaining precise results. Oven drying of the bulk materials in a conventional oven at 105 degrees C until constant mass served as reference method. A heating temperature of 65degrees C was found to provide accurate and precise results for almost all matrices investigated. To further improve the accuracy and precision, other critical parameters such as handling of sample pans, standby temperature, and measurement delay were optimized. Because of its ponderous heating behavior, the performance of the ceramic radiator was inferior to that of the halogen heater, which produced moisture results comparable to those obtained by oven drying. The developed drying procedures were successfully applied to the fast moisture analysis (1.4-6.3 min) of certified biological reference materials of similar provenance to the investigated the bulk materials. Moisture results for 200 mg aliquots ranged from 1.4 to 7.8% and good agreement was obtained between the recommended drying procedure for the reference materials and the electronic moisture analyzers with absolute uncertainties amounting to 0.1% and 0.2-0.3%, respectively.

  7. Transcriptomics and systems biology analysis in identification of specific pathways involved in cacao resistance and susceptibility to witches' broom disease.

    PubMed

    da Hora Junior, Braz Tavares; Poloni, Joice de Faria; Lopes, Maíza Alves; Dias, Cristiano Villela; Gramacho, Karina Peres; Schuster, Ivan; Sabau, Xavier; Cascardo, Júlio Cézar De Mattos; Mauro, Sônia Marli Zingaretti Di; Gesteira, Abelmon da Silva; Bonatto, Diego; Micheli, Fabienne

    2012-04-01

    This study reports on expression analysis associated with molecular systems biology of cacao-Moniliophthora perniciosa interaction. Gene expression data were obtained for two cacao genotypes (TSH1188, resistant; Catongo, susceptible) challenged or not with the fungus M. perniciosa and collected at three time points through disease. Using expression analysis, we identified 154 and 227 genes that are differentially expressed in TSH1188 and Catongo, respectively. The expression of some of these genes was confirmed by RT-qPCR. Physical protein-protein interaction (PPPI) networks of Arabidopsis thaliana orthologous proteins corresponding to resistant and susceptible interactions were obtained followed by cluster and gene ontology analyses. The integrated analysis of gene expression and systems biology allowed designing a general scheme of major mechanisms associated with witches' broom disease resistance/susceptibility. In this sense, the TSH1188 cultivar shows strong production of ROS and elicitors at the beginning of the interaction with M. perniciosa followed by resistance signal propagation and ROS detoxification. On the other hand, the Catongo genotype displays defense mechanisms that include the synthesis of some defense molecules but without success in regards to elimination of the fungus. This phase is followed by the activation of protein metabolism which is achieved with the production of proteasome associated with autophagy as a precursor mechanism of PCD. This work also identifies candidate genes for further functional studies and for genetic mapping and marker assisted selection.

  8. Health Technology Assessment: introducing a vacuum-based preservation system for biological materials in the anatomic pathology workflow.

    PubMed

    Saliceti, R; Nicodemo, E; Giannini, A; Cortese, A

    2016-03-01

    The objective of this work is to assess the implementation of a newly introduced medical equipment technology for the vacuum-based preservation of biological materials within an Anatomic Pathology service. The approach selected for the analysis is the Health Technology Assessment (HTA ), a comprehensive evaluation method based on relevant scientific evidence and designed to support healthcare decision makers in purchasing, replacing or disposing of technologies. The analysis focused on specific domains such as Technology, Organization, Safety and Economy. The study proves that the use of such technology ensures the biological specimen to be suitably preserved (up to 72 hours), both reducing the amount of fixative being employed in the diagnostic process (30% to 55%) and resulting, in the particular context under examination, in savings of 93%. The HTA reported no significant drawbacks related to the use of the technology being examined. Nonetheless, the workflow for managing the transfer of biological materials from the Operating Room to the Anatomic Pathology department needs to be redefined - in terms of handling, processing, storage and disposal. Other elements concerned the monitoring of storage temperature, fresh tissue handling and especially fixative amount reduction, which positively impacts on the operators' safety with regard to chemical hazards. © Copyright Società Italiana di Anatomia Patologica e Citopatologia Diagnostica, Divisione Italiana della International Academy of Pathology.

  9. Fracture analysis for biological materials with an expanded cohesive zone model.

    PubMed

    An, Bingbing; Zhao, Xinluo; Arola, Dwayne; Zhang, Dongsheng

    2014-07-18

    In this study, a theoretical framework for simulation of fracture of bone and bone-like materials is provided. An expanded cohesive zone model with thermodynamically consistent framework has been proposed and used to investigate the crack growth resistance of bone and bone-like materials. The reversible elastic deformation, irreversible plastic deformation caused by large deformation of soft protein matrix, and damage evidenced by the material separation and crack nucleation in the cohesive zone, were all taken into account in the model. Furthermore, the key mechanisms in deformation of biocomposites consisting of mineral platelets and protein interfacial layers were incorporated in the fracture process zone in this model, thereby overcoming the limitations of previous cohesive zone modeling of bone fracture. Finally, applications to fracture of cortical bone and human dentin were presented, which showed good agreement between numerical simulation and reported experiments and substantiated the effectiveness of the model in investigating the fracture behavior of bone-like materials.

  10. The speed of sound in silk: linking material performance to biological function.

    PubMed

    Mortimer, Beth; Gordon, Shira D; Holland, Chris; Siviour, Clive R; Vollrath, Fritz; Windmill, James F C

    2014-08-13

    Sonic properties of spider silks are measured independent of the web using laser vibrometry and ballistic impact providing insights into Nature's design of functionalized high-performance materials. Through comparison to cocoon silk and other industrial fibers, we find that major ampullate silk has the largest wavespeed range of any known material. © 2014 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Integrating mechanical and biological control of cell proliferation through bioinspired multieffector materials.

    PubMed

    Seras-Franzoso, Joaquin; Tatkiewicz, Witold I; Vazquez, Esther; García-Fruitós, Elena; Ratera, Imma; Veciana, Jaume; Villaverde, Antonio

    2015-01-01

    In nature, cells respond to complex mechanical and biological stimuli whose understanding is required for tissue construction in regenerative medicine. However, the full replication of such bimodal effector networks is far to be reached. Engineering substrate roughness and architecture allows regulating cell adhesion, positioning, proliferation, differentiation and survival, and the external supply of soluble protein factors (mainly growth factors and hormones) has been long applied to promote growth and differentiation. Further, bioinspired scaffolds are progressively engineered as reservoirs for the in situ sustained release of soluble protein factors from functional topographies. We review here how research progresses toward the design of integrative, holistic scaffold platforms based on the exploration of individual mechanical and biological effectors and their further combination.

  12. Collecting biological material from palliative care patients in the last weeks of life: a feasibility study

    PubMed Central

    Scott, Aileen; Nwosu, Amara Callistus; Latten, Richard; Wilson, James; Mayland, Catriona R; Mason, Stephen; Probert, Chris; Ellershaw, John

    2016-01-01

    Objective To assess the feasibility of prospectively collecting biological samples (urine) from palliative care patients in the last weeks of life. Setting A 30-bedded specialist hospice in the North West of England. Participants Participants were adults with a diagnosis of advanced disease and able to provide written informed consent. Method Potential participants were identified by a senior clinician over a 12-week period in 2014. They were then approached by a researcher and invited to participate according to a developed recruitment protocol. Outcomes Feasibility targets included a recruitment rate of 50%, with successful collection of samples from 80% who consented. Results A total of 58 patients were approached and 33 consented (57% recruitment rate). Twenty-five patients (43%) were unable to participate or declined; 10 (17%) became unwell, too fatigued, lost capacity, died or were discharged home; and 15 (26%) refused, usually these patients had distressing pain, low mood or profound fatigue. From the 33 recruited, 20 participants provided 128 separate urine samples, 12 participants did not meet the inclusion criteria at the time of consent and 1 participant was unable to provide a sample. The criterion for a urinary catheter was removed for the latter 6 weeks. The collection rate during the first 6 weeks was 29% and 93% for the latter 6 weeks. Seven people died while the study was ongoing, and another 4 participants died in the following 4 weeks. Conclusions It is possible to recruit and collect multiple biological samples over time from palliative care patients in the last weeks and days of life even if they have lost capacity. Research into the biological changes at the end of life could develop a greater understanding of the biology of the dying process. This may lead to improved prognostication and care of patients towards the end of life. PMID:28186928

  13. [The study of naphthyzin present in material evidence and biological fluids].

    PubMed

    Fedorov, D B; Volchenko, S V; Novokshonova, N A; Kuklin, V N

    2013-01-01

    The optimal conditions for isolation of naphazoline from naphthyzin preparations and biological fluids with chloroform at pH 9.18 are described. The compound of interest was identified with the use of color and precipitation reactions, IR and UV spectroscopy, thin-layer and gas chromatography, and chemical methods including high performance liquid chromatography, chromatodensitometry, and UV spectroscopy. The results obtained by the three methods are comparable.

  14. Analytical approaches to determination of carnitine in biological materials, foods and dietary supplements.

    PubMed

    Dąbrowska, Monika; Starek, Małgorzata

    2014-01-01

    l-Carnitine is a vitamin-like amino acid derivative, which is an essential factor in fatty acid metabolism as acyltransferase cofactor and in energy production processes, such as interconversion in the mechanisms of regulation of cetogenesis and termogenesis, and it is also used in the therapy of primary and secondary deficiency, and in other diseases. The determination of carnitine and acyl-carnitines can provide important information about inherited or acquired metabolic disorders, and for monitoring the biochemical effect of carnitine therapy. The endogenous carnitine pool in humans is maintained by biosynthesis and absorption of carnitine from the diet. Carnitine has one asymmetric carbon giving two stereoisomers d and l, but only the l form has a biological positive effect, thus chiral recognition of l-carnitine enantiomers is extremely important in biological, chemical and pharmaceutical sciences. In order to get more insight into carnitine metabolism and synthesis, a sensitive analysis for the determination of the concentration of free carnitine, carnitine esters and the carnitine precursors is required. Carnitine has been investigated in many biochemical, pharmacokinetic, metabolic and toxicokinetic studies and thus many analytical methods have been developed and published for the determination of carnitine in foods, dietary supplements, pharmaceutical formulations, biological tissues and body fluid. The analytical procedures presented in this review have been validated in terms of basic parameters (linearity, limit of detection, limit of quantitation, sensitivity, accuracy, and precision). This article presented the impact of different analytical techniques, and provides an overview of applications that address a diverse array of pharmaceutical and biological questions and samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Detection of amphetamine and methamphetamine-type materials in pharmaceutical and biological fluids by fluorometric labeling.

    PubMed

    Hopen, T J; Briner, R C; Sadler, H G; Smith, R L

    1976-10-01

    A rapid and sensitive method for detecting amphetamine and methamphetamine in drug preparations and biological fluids has been developed. Amphetamine and methamphetamine in pharmaceutical and clandestine drug preparations can be easily screened from other contaminating drugs and readily identified by their fluorescence, with subsequent separation accomplished by TLC. The same general procedure can also be used to detect amphetamine and methamphetamine in human urine at concentrations of 0.1 mug/ml.

  16. Microcantilever technology for law enforcement and anti-terrorism applications: chemical, biological, and explosive material detection

    NASA Astrophysics Data System (ADS)

    Adams, J. D.; Rogers, B.; Whitten, R.

    2005-05-01

    The remarkable sensitivity, compactness, low cost, low power-consumption, scalability, and versatility of microcantilever sensors make this technology among the most promising solutions for detection of chemical and biological agents, as well as explosives. The University of Nevada, Reno, and Nevada Nanotech Systems, Inc (NNTS) are currently developing a microcantilever-based detection system that will measure trace concentrations of explosives, toxic chemicals, and biological agents in air. A baseline sensor unit design that includes the sensor array, electronics, power supply and air handling has been created and preliminary demonstrations of the microcantilever platform have been conducted. The envisioned device would measure about two cubic inches, run on a small watch battery and cost a few hundred dollars. The device could be operated by untrained law enforcement personnel. Microcantilever-based devices could be used to "sniff out" illegal and/or hazardous chemical and biological agents in high traffic public areas, or be packaged as a compact, low-power system used to monitor cargo in shipping containers. Among the best detectors for such applications at present is the dog, an animal which is expensive, requires significant training and can only be made to work for limited time periods. The public is already accustomed to explosives and metal detection systems in airports and other public venues, making the integration of the proposed device into such security protocols straightforward.

  17. Ethical and legal considerations regarding the ownership and commercial use of human biological materials and their derivatives

    PubMed Central

    Petrini, Carlo

    2012-01-01

    This article considers some of the ethical and legal issues relating to the ownership and use – including for commercial purposes – of biological material and products derived from humans. The discussion is divided into three parts: after first examining the general notion of ownership, it moves to the particular case of possible commercial use, and finally reflects on the case in point in the light of the preceding considerations. Units of cord blood donated altruistically for transplantation and which are found unsuitable for storage and transplantation, or which become unsuitable while stored in biobanks, are taken as an example. These cord-blood units can be discarded together with other biological waste, or they can be used for research or the development of blood-derived products such as platelet gel. Several ethical questions (eg, informed consent, property, distribution of profits, and others) arise from these circumstances. In this regard, some criteria and limits to use are proposed. PMID:22977316

  18. Adventitious agents and live viral vectored vaccines: Considerations for archiving samples of biological materials for retrospective analysis.

    PubMed

    Klug, Bettina; Robertson, James S; Condit, Richard C; Seligman, Stephen J; Laderoute, Marian P; Sheets, Rebecca; Williamson, Anna-Lise; Gurwith, Marc; Kochhar, Sonali; Chapman, Louisa; Carbery, Baevin; Mac, Lisa M; Chen, Robert T

    2016-12-12

    Vaccines are one of the most effective public health medicinal products with an excellent safety record. As vaccines are produced using biological materials, there is a need to safeguard against potential contamination with adventitious agents. Adventitious agents could be inadvertently introduced into a vaccine through starting materials used for production. Therefore, extensive testing has been recommended at specific stages of vaccine manufacture to demonstrate the absence of adventitious agents. Additionally, the incorporation of viral clearance steps in the manufacturing process can aid in reducing the risk of adventitious agent contamination. However, for live viral vaccines, aside from possible purification of the virus or vector, extensive adventitious agent clearance may not be feasible. In the event that an adventitious agent is detected in a vaccine, it is important to determine its origin, evaluate its potential for human infection and pathology, and discern which batches of vaccine may have been affected in order to take risk mitigation action. To achieve this, it is necessary to have archived samples of the vaccine and ancillary components, ideally from developmental through to current batches, as well as samples of the biological materials used in the manufacture of the vaccine, since these are the most likely sources of an adventitious agent. The need for formal guidance on such vaccine sample archiving has been recognized but not fulfilled. We summarize in this paper several prior major cases of vaccine contamination with adventitious agents and provide points for consideration on sample archiving of live recombinant viral vector vaccines for use in humans.

  19. Biological activity and migration of wear particles in the knee joint: an in vivo comparison of six different polyethylene materials.

    PubMed

    Utzschneider, S; Lorber, V; Dedic, M; Paulus, A C; Schröder, C; Gottschalk, O; Schmitt-Sody, M; Jansson, V

    2014-06-01

    Wear of polyethylene causes loosening of joint prostheses because of the particle mediated activity of the host tissue. It was hypothesized that conventional and crosslinked polyethylene particles lead to similar biological effects around the knee joint in vivo as well as to a similar particle distribution in the surrounding tissues. To verify these hypotheses, particle suspensions of six different polyethylene materials were injected into knee joints of Balb/C mice and intravital microscopic, histological and immunohistochemical evaluations were done after 1 week. Whereas the biological effects on the synovial layer and the subchondral bone of femur and tibia were similar for all the polyethylenes, two crosslinked materials showed an elevated cytokine expression in the articular cartilage. Furthermore, the distribution of particles around the joint was dependent on the injected polyethylene material. Those crosslinked particles, which remained mainly in the joint space, showed an increased expression of TNF-alpha in articular cartilage. The data of this study support the use of crosslinked polyethylene in total knee arthroplasty. In contrast, the presence of certain crosslinked wear particles in the joint space can lead to an elevated inflammatory reaction in the remaining cartilage, which challenges the potential use of those crosslinked polyethylenes for unicondylar knee prostheses.

  20. Fluorescent and Magnetic Mesoporous Hybrid Material: A Chemical and Biological Nanosensor for Hg2+ Ions

    PubMed Central

    Suresh, Moorthy; Anand, Chokkalingam; Frith, Jessica E.; Dhawale, Dattatray S.; Subramaniam, Vishnu P.; Strounina, Ekaterina; Sathish, Clastinrusselraj I.; Yamaura, Kazunari; Cooper-White, Justin J.; Vinu, Ajayan

    2016-01-01

    We introduce “sense, track and separate” approach for the removal of Hg2+ ion from aqueous media using highly ordered and magnetic mesoporous ferrosilicate nanocages functionalised with rhodamine fluorophore derivative. These functionalised materials offer both fluorescent and magnetic properties in a single system which help not only to selectively sense the Hg2+ ions with a high precision but also adsorb and separate a significant amount of Hg2+ ion in aqueous media. We demonstrate that the magnetic affinity of these materials, generated from the ultrafine γ-Fe2O3 nanoparticles present inside the nanochannels of the support, can efficiently be used as a fluorescent tag to sense the Hg2+ ions present in NIH3T3 fibroblasts live cells and to track the movement of the cells by external magnetic field monitored using confocal fluorescence microscopy. This simple approach of introducing multiple functions in the magnetic mesoporous materials raise the prospect of creating new advanced functional materials by fusing organic, inorganic and biomolecules to create advanced hybrid nanoporous materials which have a potential use not only for sensing and the separation of toxic metal ions but also for cell tracking in bio-separation and the drug delivery. PMID:26911660