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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. 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. PMID:24451343

  3. Active Biological Materials

    PubMed Central

    Fletcher, Daniel A.; Geissler, Phillip L.

    2011-01-01

    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. PMID:18999991

  4. 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.

  5. Liquid Crystalline Materials for Biological Applications

    PubMed Central

    Lowe, Aaron M.; Abbott, Nicholas L.

    2012-01-01

    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. PMID:22563142

  6. 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... Biological Material § 1.801 Biological material. For the purposes of these regulations pertaining to the deposit of biological material for purposes of patents for inventions under 35 U.S.C. 101, the...

  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... Biological Material § 1.801 Biological material. For the purposes of these regulations pertaining to the deposit of biological material for purposes of patents for inventions under 35 U.S.C. 101, the...

  8. Biologically inspired dynamic material systems.

    PubMed

    Studart, André R

    2015-03-01

    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. PMID:25583299

  9. Biological materials for dynamic holography

    NASA Astrophysics Data System (ADS)

    Kozhevnikov, Nikolai M.

    1997-02-01

    Intrinsic properties of biological materials making them outstanding candidates for technical applications are briefly summarized in the paper. The origin of the light- driven optical non-linearity of bacteriorhodopsin (BR) is demonstrated. The fields of the most effective application of BR are analyzed on the basis of the last year's scientific publications. Attention is attracted to adaptive measuring interferometers with dynamic holographic beamscouplers based on BR. Several examples of such interferometers are discussed introducing one of the most promising BR application.

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. Immune Response to Biologic Scaffold Materials

    PubMed Central

    Badylak, Stephen F.; Gilbert, Thomas W.

    2008-01-01

    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. PMID:18083531

  15. Dielectric constant microscopy for biological materials

    NASA Astrophysics Data System (ADS)

    Valavade, A. V.; Kothari, D. C.; Löbbe, C.

    2013-02-01

    This paper describes the work on the development of Dielectric Constant Microscopy for biological materials using double pass amplitude modulation method. The dielectric constant information can be obtained at nanometer scales using this technique. Electrostatic force microscopy images of biological materials are presented. The images obtained from the EFM technique mode clearly show inversion contrast and gives the spatial variation of tip-sample capacitance. The EFM images are further processed to obtain dielectric constant information at nanometer scales.

  16. 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. PMID:26750617

  17. 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.

  18. The Structural Biology of Enzymes Involved in Natural Product Glycosylation

    PubMed Central

    Singh, Shanteri; Phillips, George N.

    2012-01-01

    The glycosylation of microbial natural products often dramatically influences the biological and/or pharmacological activities of the parental metabolite. Over the past decade, crystal structures of several enzymes involved in the biosynthesis and attachment of novel sugars found appended to natural products have emerged. In many cases, these studies have paved the way to a better understanding of the corresponding enzyme mechanism of action and have served as a starting point for engineering variant enzymes to facilitate to production of differentially-glycosylated natural products. This review specifically summarizes the structural studies of bacterial enzymes involved in biosynthesis of novel sugar nucleotides. PMID:22688446

  19. 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...

  20. 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...

  1. 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...

  2. 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. PMID:26963630

  3. Structural biological materials: Overview of current research

    NASA Astrophysics Data System (ADS)

    Chen, P.-Y.; Lin, A. Y.-M.; Stokes, A. G.; Seki, Y.; Bodde, S. G.; McKittrick, J.; Meyers, M. A.

    2008-06-01

    Through specific biological examples this article illustrates the complex designs that have evolved in nature to address strength, toughness, and weight optimization. Current research is reviewed, and the structure of some shells, bones, antlers, crab exoskeletons, and avian feathers and beaks is described using the principles of materials science and engineering by correlating the structure with mechanical properties. In addition, the mechanisms of deformation and failure are discussed.

  4. 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. PMID:8032455

  5. Quantification of DNA in Biologic Scaffold Materials

    PubMed Central

    Gilbert, Thomas W.; Freund, John; Badylak, Stephen F.

    2009-01-01

    Biologic scaffold materials composed of extracellular matrix (ECM) are routinely used for a variety of clinical applications ranging from the treatment of chronic skin ulcers to hernia repair and orthopaedic soft tissue reconstruction. The tissues and species from which the ECM is harvested vary widely as do the methods used to remove the cellular component of the source tissues. The efficacy of decellularization procedures can be quantified by examination of the DNA that remains in the ECM. The objective of the present study was to determine the DNA content and fragment length in both laboratory produced and commercially available ECM scaffold materials. Results showed that the majority of DNA is removed from ECM devices but that small amounts remained in most tested materials. PMID:18619621

  6. Learning from systems biology: An ``Omics'' approach to materials design

    NASA Astrophysics Data System (ADS)

    Rajan, Krishna

    2008-03-01

    An understanding of systems biology provides an excellent paradigm for the materials scientist. Ultimately one would like to take an “atoms-applications” approach to materials design. This paper describes how the concepts of genomics, proteomics, and other biological behavior which form the foundations of modern biology can be applied to materials design through materials informatics.

  7. Viscoelastic characterization of soft biological materials

    NASA Astrophysics Data System (ADS)

    Nayar, Vinod Timothy

    Progressive and irreversible retinal diseases are among the primary causes of blindness in the United States, attacking the cells in the eye that transform environmental light into neural signals for the optic pathway. Medical implants designed to restore visual function to afflicted patients can cause mechanical stress and ultimately damage to the host tissues. Research shows that an accurate understanding of the mechanical properties of the biological tissues can reduce damage and lead to designs with improved safety and efficacy. Prior studies on the mechanical properties of biological tissues show characterization of these materials can be affected by environmental, length-scale, time, mounting, stiffness, size, viscoelastic, and methodological conditions. Using porcine sclera tissue, the effects of environmental, time, and mounting conditions are evaluated when using nanoindentation. Quasi-static tests are used to measure reduced modulus during extended exposure to phosphate-buffered saline (PBS), as well as the chemical and mechanical analysis of mounting the sample to a solid substrate using cyanoacrylate. The less destructive nature of nanoindentation tests allows for variance of tests within a single sample to be compared to the variance between samples. The results indicate that the environmental, time, and mounting conditions can be controlled for using modified nanoindentation procedures for biological samples and are in line with averages modulus values from previous studies but with increased precision. By using the quasi-static and dynamic characterization capabilities of the nanoindentation setup, the additional stiffness and viscoelastic variables are measured. Different quasi-static control methods were evaluated along with maximum load parameters and produced no significant difference in reported reduced modulus values. Dynamic characterization tests varied frequency and quasi-static load, showing that the agar could be modeled as a linearly

  8. [Placebo effect: clinical, biological and therapeutical involvements in depression].

    PubMed

    Gourion, D; Mouchabac, S

    2016-02-01

    The placebo effect is an excellent model for understanding the mechanisms underlying the interaction between a subjective and complex mental activity (beliefs, expectations, hopes, learning, patient-physician relationship, socio-cultural context .) with different neural and biological systems. Initially, research on the placebo effect has focused on the mechanisms of pain and analgesia. The cognitive processes of conditioning and reward anticipation (hope of a relief) were highlighted. The involvement of different neurobiological pathways has been clearly shown: endogenous opioids, CCK, dopaminergic pathways, endocannabinoids, immunological factors… More recently, the field has open towards new perspectives: depression and anxiety, motor disorders, immune system, endocrine system. Intensive research in the field emerges because of its fundamental implications in neuroscience research but also because of the ethical, clinical and therapeutical issues. Moreover, the placebo effect is considered as a main methodological mean issue in clinical trials that allows the demonstration of the efficacy and tolerance of new drugs. In the field of psychiatry, depression is a placebo highly-sensitive disorder: placebo response rates in clinical trials are of the order of 30 % to 40 %. The identification of biological markers of placebo response, such as neuroimaging and quantitative electroencephalography may lead to develop more efficient models in clinical research. PMID:26879253

  9. The cutting edge: Sharp biological materials

    NASA Astrophysics Data System (ADS)

    Meyers, M. A.; Lin, A. Y. M.; Lin, Y. S.; Olevsky, E. A.; Georgalis, S.

    2008-03-01

    Through hundreds of millions of years of evolution, organisms have developed a myriad of ingenious solutions to ensure and optimize survival and success. Biological materials that comprise organisms are synthesized at ambient temperature and pressure and mostly in aqueous environments. This process, mediated by proteins, limits the range of materials at the disposal of nature and therefore the design plays a pivotal role. This article focuses on sharp edges and serrations as important survival and predating mechanisms in a number of plants, insects, fishes, and mammals. Some plants have sharp edges covered with serrations. The proboscis of mosquitoes and stinger of bees are examples in insects. Serrations are a prominent feature in many fish teeth, and rodents have teeth that are sharpened continuously, ensuring their sharpness and efficacy. Some current bioinspired applications will also be reviewed.

  10. 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. PMID:24591042

  11. 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

  12. Femtosecond laser patterning of biological materials

    NASA Astrophysics Data System (ADS)

    Grigoropoulos, Costas P.; Jeon, Hojeong; Hidai, Hirofumi; Hwang, David J.

    2011-03-01

    This paper aims at presenting a review of work at the Laser Thermal Laboratory on the microscopic laser modification of biological materials using ultrafast laser pulses. We have devised a new method for fabricating high aspect ratio patterns of varying height by using two-photon polymerization process in order to study contact guidance and directed growth of biological cells. Studies using NIH-3T3 and MDCK cells indicate that cell morphology on fiber scaffolds is influenced by the pattern of actin microfilament bundles. Cells experienced different strength of contact guidance depending on the ridge height. Cell morphology and motility was investigated on micronscale anisotropic cross patterns and parallel line patterns having different aspect ratios. A significant effect on cell alignment and directionality of migration was observed. Cell morphology and motility were influenced by the aspect ratio of the cross pattern, the grid size, and the ridge height. Cell contractility was examined microscopically in order to measure contractile forces generated by individual cells on self-standing fiber scaffolds.

  13. 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

  14. 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.

  15. Fathers' Involvement with Their Nonresident Children and Material Hardship

    PubMed Central

    Nepomnyaschy, Lenna; Garfinkel, Irwin

    2011-01-01

    Children in single-parent families, particularly children born to unmarried parents, are at high risk for experiencing material hardship. Previous research based on cross-sectional data suggests that father involvement, especially visitation, diminishes hardship. This article uses longitudinal data to examine the associations between nonresident fathers' involvement with their children and material hardship in the children's households. Results suggest that fathers' formal and informal child support payments and contact with their children independently reduce the number of hardships in the mothers' households; however, only the impact of fathers' contact with children is robust in models that include lagged dependent variables or individual fixed effects. Furthermore, cross-lagged models suggest that material hardship decreases future father involvement, but future hardship is not diminished by father involvement (except in-kind contributions). These results point to the complexity of these associations and to the need for future research to focus on heterogeneity of effects within the population. PMID:21822335

  16. 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.

  17. BIOLOGICAL ACTIVITY AND POTENTIAL REMEDIATION INVOLVING GEOTEXTILE LANDFILL LEACHATE FILTERS

    EPA Science Inventory

    This paper presents the results of a biological growth study in geotextile filters used in landfill leachate collection systems. fter reviewing the first year's activity, a completely new experimental approach has been taken. sing 100 mm diameter columns for the experimental incu...

  18. 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…

  19. 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.

  20. 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.

  1. 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. PMID:24908518

  2. The acquisition of dangerous biological materials :

    SciTech Connect

    Aceto, Donato Gonzalo; Astuto-Gribble, Lisa M.; Gaudioso, Jennifer M.

    2007-11-01

    Numerous terrorist organizations have openly expressed interest in producing and deploying biological weapons. However, a limiting factor for many terrorists has been the acquisition of dangerous biological agents, as evidenced by the very few successful instances of biological weapons use compared to the number of documented hoaxes. Biological agents vary greatly in their ability to cause loss of life and economic damage. Some agents, if released properly, can kill many people and cause an extensive number of secondary infections; other agents will sicken only a small number of people for a short period of time. Consequently, several biological agents can potentially be used to perpetrate a bioterrorism attack but few are likely capable of causing a high consequence event. It is crucial, from a US national security perspective, to more deeply understand the likelihood that terrorist organizations can acquire the range of these agents. Few studies have attempted to comprehensively compile the technical information directly relevant to the acquisition of dangerous bacteria, viruses and toxins. In this report, technical fact sheets were assembled for 46 potentially dangerous biological agents. Much of the information was taken from various research sources which could ultimately and significantly expedite and improve bioterrorism threat assessments. By systematically examining a number of specific agent characteristics included in these fact sheets, it may be possible to detect, target, and implement measures to thwart future terrorist acquisition attempts. In addition, the information in these fact sheets may be used as a tool to help laboratories gain a rudimentary understanding of how attractive a method laboratory theft is relative to other potential acquisition modes.

  3. Identification of Inhibitors of Biological Interactions Involving Intrinsically Disordered Proteins

    PubMed Central

    Marasco, Daniela; Scognamiglio, Pasqualina Liana

    2015-01-01

    Protein–protein interactions involving disordered partners have unique features and represent prominent targets in drug discovery processes. Intrinsically Disordered Proteins (IDPs) are involved in cellular regulation, signaling and control: they bind to multiple partners and these high-specificity/low-affinity interactions play crucial roles in many human diseases. Disordered regions, terminal tails and flexible linkers are particularly abundant in DNA-binding proteins and play crucial roles in the affinity and specificity of DNA recognizing processes. Protein complexes involving IDPs are short-lived and typically involve short amino acid stretches bearing few “hot spots”, thus the identification of molecules able to modulate them can produce important lead compounds: in this scenario peptides and/or peptidomimetics, deriving from structure-based, combinatorial or protein dissection approaches, can play a key role as hit compounds. Here, we propose a panoramic review of the structural features of IDPs and how they regulate molecular recognition mechanisms focusing attention on recently reported drug-design strategies in the field of IDPs. PMID:25849651

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. [Constitution of a bank of biological material. Practical aspects].

    PubMed

    Henny, J

    2003-02-01

    A bank of biological materials (Biorepositories) aims to collect and preserve in a variable time period (from few days to several years) various biological samples (serum, plasma, cells, DNA, etc) with a view to make subsequent analysis associated with a powerful information management system, enabling the storage of data related to the biological specimens. The bioprocessing of Biorepositories is complex and include: specimen collection, processing issues, identification process, design equipment: liquid nitrogen and mechanical freezers, storage techniques, bioclinical information and biological specimens inventory management systems, quality assurance programs, ethical and legal problems. PMID:12684569

  10. 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

  11. Wear and abrasion resistance selection maps of biological materials.

    PubMed

    Amini, Shahrouz; Miserez, Ali

    2013-08-01

    The mechanical design of biological materials has generated widespread interest in recent years, providing many insights into their intriguing structure-property relationships. A critical characteristic of load-bearing materials, which is central to the survival of many species, is their wear and abrasion tolerance. In order to be fully functional, protective armors, dentitious structures and dynamic appendages must be able to tolerate repetitive contact loads without significant loss of materials or internal damage. However, very little is known about this tribological performance. Using a contact mechanics framework, we have constructed materials selection charts that provide general predictions about the wear performance of biological materials as a function of their fundamental mechanical properties. One key assumption in constructing these selection charts is that abrasion tolerance is governed by the first irreversible damage at the contact point. The maps were generated using comprehensive data from the literature and encompass a wide range of materials, from heavily mineralized to fully organic materials. Our analysis shows that the tolerance of biological materials against abrasion depends on contact geometry, which is ultimately correlated to environmental and selective pressures. Comparisons with experimental data from nanoindentation experiments are also drawn in order to verify our predictions. With the increasing amount of data available for biological materials also comes the challenge of selecting relevant model systems for bioinspired materials engineering. We suggest that these maps will be able to guide this selection by providing an overview of biological materials that are predicted to exhibit the best abrasion tolerance, which is of fundamental interest for a wide range of applications, for instance in restorative implants and protective devices. PMID:23643608

  12. [Species and group classification of putrefied biological material].

    PubMed

    Kulhányová, V

    1994-05-01

    The author analyzes some experience in serological examinations of biological material which undergoes putrefaction. The aim of the examinations was to evaluate how long is it possible to assess species and group specific properties in material altered by putrefaction. PMID:8023197

  13. 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.

  14. 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

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

    PubMed

    Buehler, Markus J; Ackbarow, Theodor

    2008-12-01

    Biological protein materials (BPMs), intriguing hierarchical structures formed by assembly of chemical building blocks, are crucial for critical functions of life. The structural details of BPMs are fascinating: They represent a combination of universally found motifs such as alpha-helices or beta-sheets with highly adapted protein structures such as cytoskeletal networks or spider silk nanocomposites. BPMs combine properties like strength and robustness, self-healing ability, adaptability, changeability, evolvability and others into multi-functional materials at a level unmatched in synthetic materials. The ability to achieve these properties depends critically on the particular traits of these materials, first and foremost their hierarchical architecture and seamless integration of material and structure, from nano to macro. Here, we provide a brief review of this field and outline new research directions, along with a review of recent research results in the development of structure-property relationships of biological protein materials exemplified in a study of vimentin intermediate filaments. PMID:18803059

  16. The host response to allogeneic and xenogeneic biological scaffold materials.

    PubMed

    Keane, Timothy J; Badylak, Stephen F

    2015-05-01

    The clinical use of biological scaffold materials has become commonplace. Such scaffolds are composed of extracellular matrix (ECM), or components of ECM, derived from allogeneic or xenogeneic tissues. Such scaffold materials vary widely in their source tissue, processing methods and sterilization methods. The success or failure of an ECM scaffold for a given application is dependent on the host response following implantation; a response that is largely mediated by the innate immune system and which is influenced by a numerous factors, including the processing methods used in the preparation of biological scaffolds. The present paper reviews various aspects of the host response to biological scaffolds and factors that affect this response. In addition, some of the logistical, regulatory and reconstructive implications associated with the use of biological scaffolds are discussed. PMID:24668694

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

    PubMed

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

    2015-12-01

    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. PMID:25393596

  18. 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.

  19. Near-Infrared Fluorescent Materials for Sensing of Biological Targets

    PubMed Central

    Amiot, Carrie L.; Xu, Shuping; Liang, Song; Pan, Lingyun; Zhao, Julia Xiaojun

    2008-01-01

    Near-infrared fluorescent (NIRF) materials are promising labeling reagents for sensitive determination and imaging of biological targets. In the near-infrared region biological samples have low background fluorescence signals, providing high signal to noise ratio. Meanwhile, near-infrared radiation can penetrate into sample matrices deeply due to low light scattering. Thus, in vivo and in vitro imaging of biological samples can be achieved by employing the NIRF probes. To take full advantage of NIRF materials in the biological and biomedical field, one of the key issues is to develop intense and biocompatible NIRF probes. In this review, a number of NIRF materials are discussed including traditional NIRF dye molecules, newly developed NIRF quantum dots and single-walled carbon nanotubes, as well as rare earth metal compounds. The use of some NIRF materials in various nanostructures is illustrated. The enhancement of NIRF using metal nanostructures is covered as well. The fluorescence mechanism and bioapplications of each type of the NIRF materials are discussed in details.

  20. 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. PMID:18153999

  1. 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.

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

    Energy Science and Technology Software Center (ESTSC)

    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, explosivemore » 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

  3. 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.

  4. Occupational Orientation: Applied Biological and Agricultural Occupations. Experimental Curriculum Materials.

    ERIC Educational Resources Information Center

    Illinois State Office of Education, Springfield.

    These experimental curriculum materials, from one of five clusters developed for the occupational orientation program in Illinois, include a series of learning activity packages (LAPs) designed to acquaint the student with the wide range of occupational choices available in the applied biological and agricultural occupations. The 30 LAPs, each…

  5. 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.

  6. Overview of light interaction with food and biological materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Theory of light transfer in food and biological materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. 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.

  9. 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.

  10. 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.

  11. On optimal hierarchy of load-bearing biological materials

    PubMed Central

    Zhang, Zuoqi; Zhang, Yong-Wei; Gao, Huajian

    2011-01-01

    Load-bearing biological materials such as shell, mineralized tendon and bone exhibit two to seven levels of structural hierarchy based on constituent materials (biominerals and proteins) of relatively poor mechanical properties. A key question that remains unanswered is what determines the number of hierarchical levels in these materials. Here we develop a quasi-self-similar hierarchical model to show that, depending on the mineral content, there exists an optimal level of structural hierarchy for maximal toughness of biocomposites. The predicted optimal levels of hierarchy and cooperative deformation across multiple structural levels are in excellent agreement with experimental observations. PMID:20810437

  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. Synthetic Self-Assembled Materials in Biological Environments.

    PubMed

    Versluis, Frank; van Esch, Jan H; Eelkema, Rienk

    2016-06-01

    Synthetic self-assembly has long been recognized as an excellent approach for the formation of ordered structures on the nanoscale. Although the development of synthetic self-assembling materials has often been inspired by principles observed in nature (e.g., the assembly of lipids, DNA, proteins), until recently the self-assembly of synthetic molecules has mainly been investigated ex vivo. The past few years however, have witnessed the emergence of a research field in which synthetic, self-assembling systems are used that are capable of operating as bioactive materials in biological environments. Here, this up-and-coming field, which has the potential of becoming a key area in chemical biology and medicine, is reviewed. Two main categories of applications of self-assembly in biological environments are identified and discussed, namely therapeutic and imaging agents. Within these categories key concepts, such as triggers and molecular constraints for in vitro/in vivo self-assembly and the mode of interaction between the assemblies and the biological materials will be discussed. PMID:27042774

  15. 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

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

    PubMed

    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. PMID:24415796

  17. 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.

  18. Systems analysis of gene ontology and biological pathways involved in post-myocardial infarction responses

    PubMed Central

    2015-01-01

    Background Pathway analysis has been widely used to gain insight into essential mechanisms of the response to myocardial infarction (MI). Currently, there exist multiple pathway databases that organize molecular datasets and manually curate pathway maps for biological interpretation at varying forms of organization. However, inconsistencies among different databases in pathway descriptions, frequently due to conflicting results in the literature, can generate incorrect interpretations. Furthermore, although pathway analysis software provides detailed images of interactions among molecules, it does not exhibit how pathways interact with one another or with other biological processes under specific conditions. Methods We propose a novel method to standardize descriptions of enriched pathways for a set of genes/proteins using Gene Ontology terms. We used this method to examine the relationships among pathways and biological processes for a set of condition-specific genes/proteins, represented as a functional biological pathway-process network. We applied this algorithm to a set of 613 MI-specific proteins we previously identified. Results A total of 96 pathways from Biocarta, KEGG, and Reactome, and 448 Gene Ontology Biological Processes were enriched with these 613 proteins. The pathways were represented as Boolean functions of biological processes, delivering an interactive scheme to organize enriched information with an emphasis on involvement of biological processes in pathways. We extracted a network focusing on MI to demonstrate that tyrosine phosphorylation of Signal Transducer and Activator of Transcription (STAT) protein, positive regulation of collagen metabolic process, coagulation, and positive/negative regulation of blood coagulation have immediate impacts on the MI response. Conclusions Our method organized biological processes and pathways in an unbiased approach to provide an intuitive way to identify biological properties of pathways under specific

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

    DOEpatents

    Schabron, John F.; 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.

  20. 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.

  1. Accurate determination of cobalt traces in several biological reference materials.

    PubMed

    Dybczyński, R; Danko, B

    1994-01-01

    A newly devised, very accurate ("definitive") method for the determination of trace amounts of cobalt in biological materials was validated by the analysis of several certified reference materials. The method is based on a combination of neutron activation and selective and quantitative postirradiation isolation of radiocobalt from practically all other radionuclides by ion-exchange and extraction chromatography followed by gamma-ray spectrometric measurement. The significance of criteria that should be fulfilled in order to accept a given result as obtained by the "definitive method" is emphasized. In view of the demonstrated very good accuracy of the method, it is suggested that our values for cobalt content in those reference materials in which it was originally not certified (SRM 1570 spinach, SRM 1571 orchard leaves, SRM 1577 bovine liver, and Czechoslovak bovine liver 12-02-01) might be used as provisional certified values. PMID:7710879

  2. Microdosimetry of fast neutrons in selected biological materials

    SciTech Connect

    Wallace, R.E.

    1987-01-01

    Microdosimetric quantities for selected neutron beams have been determined in muscle, brain, bone, and fat tissue equivalent materials. The quantities of interest were the dose distribution in lineal energy, frequency average lineal energy, dose average lineal energy, and dose average quality factor. A dose response factor was defined to combine the lineal energy dose spectrum with a response function per unit KERMA for an acute biological endpoint in prototype cells in vitro. The dependence of each quantity on material composition and neutron energy was investigated by theoretical calculation and separated into primary and scatter neutron fluence components. Neutron fluences in phantoms were calculated using a standard Monte Carlo code (MCNP). The charged particle fluences and lineal energy dose spectra were obtained using the continuous slowing-down approximation. Calculated microdosimetric spectra agreed with those measured in muscle-equivalent materials. The microdosimetry of primary and scattered neutrons in a large tissue phantom was calculated for three representative uncollimated neutron sources.

  3. Classification of organic and biological materials with deep ultraviolet excitation.

    PubMed

    Bhartia, Rohit; Hug, Willam F; Salas, Everett C; Reid, Ray D; Sijapati, Kripa K; Tsapin, Alexandre; Abbey, William; Nealson, Kenneth H; Lane, Arthur L; Conrad, Pamela G

    2008-10-01

    We show that native fluorescence can be used to differentiate classes or groups of organic molecules and biological materials when excitation occurs at specific excitation wavelengths in the deep ultraviolet (UV) region. Native fluorescence excitation-emission maps (EEMs) of pure organic materials, microbiological samples, and environmental background materials were compared using excitation wavelengths between 200-400 nm with emission wavelengths from 270 to 500 nm. These samples included polycyclic aromatic hydrocarbons (PAHs), nitrogen- and sulfur-bearing organic heterocycles, bacterial spores, and bacterial vegetative whole cells (both Gram positive and Gram negative). Each sample was categorized into ten distinct groups based on fluorescence properties. Emission spectra at each of 40 excitation wavelengths were analyzed using principal component analysis (PCA). Optimum excitation wavelengths for differentiating groups were determined using two metrics. We show that deep UV excitation at 235 (+/-2) nm optimally separates all organic and biological groups within our dataset with >90% confidence. For the specific case of separation of bacterial spores from all other samples in the database, excitation at wavelengths less than 250 nm provides maximum separation with >6sigma confidence. PMID:18926014

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

    PubMed Central

    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. PMID:24225319

  5. A comparison of form processing involved in the perception of biological and nonbiological movements.

    PubMed

    Thurman, Steven M; Lu, Hongjing

    2016-01-01

    Although there is evidence for specialization in the human brain for processing biological motion per se, few studies have directly examined the specialization of form processing in biological motion perception. The current study was designed to systematically compare form processing in perception of biological (human walkers) to nonbiological (rotating squares) stimuli. Dynamic form-based stimuli were constructed with conflicting form cues (position and orientation), such that the objects were perceived to be moving ambiguously in two directions at once. In Experiment 1, we used the classification image technique to examine how local form cues are integrated across space and time in a bottom-up manner. By comparing with a Bayesian observer model that embodies generic principles of form analysis (e.g., template matching) and integrates form information according to cue reliability, we found that human observers employ domain-general processes to recognize both human actions and nonbiological object movements. Experiments 2 and 3 found differential top-down effects of spatial context on perception of biological and nonbiological forms. When a background does not involve social information, observers are biased to perceive foreground object movements in the direction opposite to surrounding motion. However, when a background involves social cues, such as a crowd of similar objects, perception is biased toward the same direction as the crowd for biological walking stimuli, but not for rotating nonbiological stimuli. The model provided an accurate account of top-down modulations by adjusting the prior probabilities associated with the internal templates, demonstrating the power and flexibility of the Bayesian approach for visual form perception. PMID:26746875

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. 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

  8. Structural instabilities involving time dependent materials : theory and experiment

    NASA Astrophysics Data System (ADS)

    Minahen, Timothy M.

    The creep buckling of viscoelastic structures is studied analytically and experimentally to investigate structural stability in the presence of time dependent materials. The theory of linear viscoelasticity is used to model polymeric column specimens subjected to constant compressive end loads. A strength of materials approach (Euler-Bernoulli beam theory) is employed to model the moment-curvature relation for the column. The growth of initial imperfections is calculated using the hereditary integral formulation. Solution techniques are developed for small displacements and then generalized to include the effects of large displacements and rotations. A failure criterion based on maximum deformation allows the column life to be estimated directly from the material relaxation modulus. A discussion generalizing the results to include plates and shells is presented.Rectangular cross-section polymethylmethacrylate (PMMA) specimens with hinged boundary conditions are used to study viscoelastic buckling experimentally. Constant compressive end loads are applied using a servo-controlled load frame while the specimens are kept in a temperature cabinet at elevated temperatures (accelerating the creep behavior). Specimen shortening and out-of-plane deflections are monitored during the tests. The relaxation modulus of PMMA is approximated by a Prony-Dirichlet series and the model is used to simulate the laboratory experiments. Model and experimental results show good agreement during the "glassy" and slow growth phases of the column response. As the growth rate increases some deviations between theory and experiment are seen. It is shown that the deviations are not a result of geometric nonlinearities, but may, in part, be explained by material nonlinearities not accounted for in the model.

  9. 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 "case". The goal of the…

  10. Investigating accidents involving aircraft manufactured from polymer composite materials

    NASA Astrophysics Data System (ADS)

    Dunn, Leigh

    This study looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. As the use of composite materials in aircraft construction increases, the understanding of how macroscopic failure characteristics of composite materials may aid the field investigator is becoming of increasing importance.. The first phase of this research project was to explore how investigation practitioners conduct wreckage examinations. Four accident investigation case studies were examined. The analysis of the case studies provided a framework of the wreckage examination process. Subsequently, a literature survey was conducted to establish the current level of knowledge on the visual and macroscopic interpretation of polymer composite failures. Relevant literature was identified and a compendium of visual and macroscopic characteristics was created. Two full-scale polymer composite wing structures were loaded statically, in an upward bending direction, until each wing structure fractured and separated. The wing structures were subsequently examined for the existence of failure characteristics. The examination revealed that whilst characteristics were present, the fragmentation of the structure destroyed valuable evidence. A hypothetical accident scenario utilising the fractured wing structures was developed, which UK government accident investigators subsequently investigated. This provided refinement to the investigative framework and suggested further guidance on the interpretation of polymer composite failures by accident investigators..

  11. 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.

  12. 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

  13. 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

    2016-01-01

    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

  14. Comparison of different sample and target preparation procedures for PIXE analysis of biological materials

    NASA Astrophysics Data System (ADS)

    Maenhaut, W.; De Reu, L.; Vandenhaute, J.

    1984-04-01

    Four different methods for preparing PIXE targets from biological samples were compared. All methods involved doping with an internal standard and preparing target deposits of 1-4 mg/cm 2 on a thin substrate. In method A targets were prepared using powdered freeze-dried material. Methods B and C both included a low temperature ashing preconcentration step and method D involved an acid digestion in a teflon bomb. The procedures were applied to reference materials (e.g. NBS standards) and to "real" samples such as human kidneys and a liver, which had been analyzed by neutron activation analysis (NAA). For most elements good agreement was observed between the results of the four target preparation methods and the reference values or the NAA results. Exceptions, however, were Br, Se and Cd, which were lost in some methods. The detection limits in the different methods are compared.

  15. The High-Strain Rate Loading of Structural Biological Materials

    NASA Astrophysics Data System (ADS)

    Proud, W. G.; Nguyen, T.-T. N.; Bo, C.; Butler, B. J.; Boddy, R. L.; Williams, A.; Masouros, S.; Brown, K. A.

    2015-10-01

    The human body can be subjected to violent acceleration as a result of explosion caused by military ordinance or accident. Blast waves cause injury and blunt trauma can be produced by violent impact of objects against the human body. The long-term clinical manifestations of blast injury can be significantly different in nature and extent to those suffering less aggressive insult. Similarly, the damage seen in lower limbs from those injured in explosion incidents is in general more severe than those falling from height. These phenomena increase the need for knowledge of the short- and long-term effect of transient mechanical loading to the biological structures of the human body. This paper gives an overview of some of the results of collaborative investigation into blast injury. The requirement for time-resolved data, appropriate mechanical modeling, materials characterization and biological effects is presented. The use of a range of loading platforms, universal testing machines, drop weights, Hopkinson bars, and bespoke traumatic injury simulators are given.

  16. [Analysis of etofenamate. Particular determination in biological material (author's transl)].

    PubMed

    Dell, H D; Fiedler, J; Wäsche, B

    1977-01-01

    The determination of 2-(2-hydroxyethoxy)-ethyl-N-(a,a,a-trifluoro-m-tolyl)-anthranilate (etofenamate, active principle of Rheumon gel) following its isolation from biological material is reported. Depending on the method of extraction etofenamate, free and alkali-labile conjugated flufenamic acid, total conjugates or the sum of CF3-containing compounds (sum of metabolites) are isolated. Separation is achieved by TLC, quantitative determination is made by degradation to flufenamic acid and fluorimetric measurement in CCl4/trichloracetic acid at 372/445 nm. Etofenamate can be identified by TLC, derivatisation, UV- and fluorescence spectroscopy and differentiated from its metabolites. It is demonstrated that etofenamate is the main component of fenamates in inflamed tissue. PMID:579119

  17. Clinical treatment adherence of health care workers and students exposed to potentially infectious biological material.

    PubMed

    Almeida, Maria Cristina Mendes de; Canini, Silvia Rita Marin da Silva; Reis, Renata Karina; Toffano, Silmara Elaine Malaguti; Pereira, Fernanda Maria Vieira; Gir, Elucir

    2015-01-01

    OBJECTIVE To assess adherence to clinical appointments by health care workers (HCW) and students who suffered accidents with potentially infectious biological material. METHOD A retrospective cross-sectional study that assessed clinical records of accidents involving biological material between 2005 and 2010 in a specialized unit. RESULTS A total of 461 individuals exposed to biological material were treated, of which 389 (84.4%) were HCWs and 72 (15.6%) students. Of the 461 exposed individuals, 307 (66.6%) attended a follow-up appointment. Individuals who had suffered an accident with a known source patient were 29 times more likely to show up to their scheduled follow-up appointments (OR: 29.98; CI95%: 16.09-55.83). CONCLUSION The predictor in both univariate and multivariate analyses for adherence to clinical follow-up appointment was having a known source patient with nonreactive serology for the human immunodeficiency virus and/or hepatitis B and C. PMID:25992825

  18. Some Recent Advances of Ultrasonic Diagnostic Methods Applied to Materials and Structures (Including Biological Ones)

    NASA Astrophysics Data System (ADS)

    Nobile, Lucio; Nobile, Stefano

    This paper gives an overview of some recent advances of ultrasonic methods applied to materials and structures (including biological ones), exploring typical applications of these emerging inspection technologies to civil engineering and medicine. In confirmation of this trend, some results of an experimental research carried out involving both destructive and non-destructive testing methods for the evaluation of structural performance of existing reinforced concrete (RC) structures are discussed in terms of reliability. As a result, Ultrasonic testing can usefully supplement coring thus permitting less expensive and more representative evaluation of the concrete strength throughout the whole structure under examination.

  19. Imaging of nonthrombotic pulmonary embolism: biological materials, nonbiological materials, and foreign bodies.

    PubMed

    Bach, Andreas Gunter; Restrepo, Carlos Santiago; Abbas, Jasmin; Villanueva, Alberto; Lorenzo Dus, María José; Schöpf, Reinhard; Imanaka, Hideaki; Lehmkuhl, Lukas; Tsang, Flora Hau Fung; Saad, Fathinul Fikri Ahmad; Lau, Eddie; Rubio Alvarez, Jose; Battal, Bilal; Behrmann, Curd; Spielmann, Rolf Peter; Surov, Alexey

    2013-03-01

    Nonthrombotic pulmonary embolism is defined as embolization to the pulmonary circulation caused by a wide range of substances of endogenous and exogenous biological and nonbiological origin and foreign bodies. It is an underestimated cause of acute and chronic embolism. Symptoms cover the entire spectrum from asymptomatic patients to sudden death. In addition to obstruction of the pulmonary vasculature there may be an inflammatory cascade that deteriorates vascular, pulmonary and cardiac function. In most cases the patient history and radiological imaging reveals the true nature of the patient's condition. The purpose of this article is to give the reader a survey on pathophysiology, typical clinical and radiological findings in different forms of nonthrombotic pulmonary embolism. The spectrum of forms presented here includes pulmonary embolism with biological materials (amniotic fluid, trophoblast material, endogenous tissue like bone and brain, fat, Echinococcus granulosus, septic emboli and tumor cells); nonbiological materials (cement, gas, iodinated oil, glue, metallic mercury, radiotracer, silicone, talc, cotton, and hyaluronic acid); and foreign bodies (lost intravascular objects, bullets, catheter fragments, intraoperative material, radioactive seeds, and ventriculoperitoneal shunts). PMID:23102488

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

    PubMed

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

    2000-09-15

    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 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

  2. Microchip electrophoresis for the analysis of biological materials

    SciTech Connect

    Jacobson, S.C.; Ramsey, J.M.

    1995-12-31

    Development of instrumentation for biological and chemical analyses is geared toward extracting more information in a shorter time period at a lower cost. One avenue to achieve these ends is the miniaturization of instrumentation using microfabrication techniques. The primary advantage of such miniaturized devices is the integration of multiple functions required for a complete analysis into a single monolithic unit. Also, by using microfabrication techniques, planar devices with compact geometries enable design of parallel architectures which would handle multiple samples and necessary redundancies. Microfabricated devices that have been demonstrated primarily involve electrically driven separation techniques including capillary electrophoresis, open channel electrochromatography, and capillary gel electrophoresis. Devices that integrate chemical reactions with analysis include capillary electrophoresis with pre- and postseparation derivatization, and restriction digestions of plasmid DNA followed by size analysis of the fragments. The most notable feature of these miniaturized chemical separation devices is the speed with which analyses are performed. These devices have precise fluid control of picoliter volumes simply by proper selection of applied potentials and without the use of mechanical valves. Further motivations for miniaturization and integration of chemical analysis procedures include low void volume connections, reduction of sample and reagent volumes, and rapid diffusional mixing of reagents.

  3. Alaska Native people's perceptions, understandings, and expectations for research involving biological specimens

    PubMed Central

    Hiratsuka, Vanessa Y.; Brown, Jennifer K.; Hoeft, Theresa J.; Dillard, Denise A.

    2012-01-01

    Objectives Members of racially and ethnically diverse groups have been persistently underrepresented in biomedical research in general, possibly due to mistrust with the medical and research community. This article describes the perceptions, understandings, and expectations of Alaska Native people about research involving the collection and storage of biological specimens. Study design Stratified focus groups. Methods Twenty-nine focus groups with Alaska Native people (n = 178) were held in 14 locations using a semi-structured moderator guide. ATLAS.ti was used for thematic analysis through iterative readings and coding. Alaska Native peoples’ perceptions, understandings, and expectations of researcher beneficence, informed consent processes, and provision of research findings were elicited. Results and conclusions Alaska Native people desired extensive disclosure of information beyond that typically provided in consent and results dissemination processes. Information germane to the motivation and intent of researchers and specifics of specimen storage and destruction were specifically requested. A clear and extensive process of informed consent and continued improvements in sharing results may enhance the transparency of research intent, conduct, and use of obtained results among Alaska Native people. Meeting expectations may improve relationships between researchers and the Alaska Native population which could result in increased research participation. Our findings offer a guide for researchers and communities when planning and implementing research with biological specimens. PMID:22663942

  4. 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

  5. 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.

  6. 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. PMID:24229099

  7. 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. PMID:7382928

  8. 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

  9. 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…

  10. 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.

  11. 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].

  12. 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. PMID:19932986

  13. An Experimental Evaluation of the Effectiveness of the Biological Sciences Curriculum Study Special Materials Approach to Teaching Biology to the Slow Learner.

    ERIC Educational Resources Information Center

    Welford, John Mack

    Students (comparable in intelligence and ability) in slow-learning classes using either "Biological Sciences Curriculum Study (BSCS) Special Materials" or some other slow-learner biology materials, were compared on the basis of scores on the "Nelson Biology Test", the "Biological Sciences; Patterns and Processes Final Examination", and two short…

  14. Ultrafast Spectroscopy in Conjugated Organic and Biological Materials

    NASA Astrophysics Data System (ADS)

    Yan, Ming

    The dynamics of two kinds of conjugated materials, the visual pigment rhodopsin and the organic polymer poly(p -phenylene vinylene), have been studied utilizing femtosecond spectroscopy. The 11-cis to all-trans torsional isomerization of the retinal chromophore in rhodopsin for both protonated and deuterated aqueous environments have been studied by time-resolved absorption measurements at room temperature. The kinetic results are well modeled by rate equations based on the scheme which involves the isomerization along the torsional coordinate of the 11-cis bond of the retinal chromophore. A metastable intermediate 90 degree twisted state is formed within 200 fs on the excited state surface by rotation around the C_{11} -C_{12} double bond, and it takes 3 ps to form the fully isomerized all -trans photoproduct known as bathorhodopsin and to repopulate the ground state rhodopsin. These results agree well with the semiempirical energy level and molecular dynamics calculations. The observed dynamics are insensitive to deuteration of the exchangeable protons which suggest that proton translocation is unimportant at physiological temperatures. The conjugated polymer, Poly(p-phenylene vinylene) (PPV) in a stretch oriented film, has been studied using polarized time-resolved absorption with subpicosecond resolution and transient luminescence measurements. Excitations are generated by photoexcitation near the band edge (500nm -540nm) with a 200 fs pulse and the resulting spectral changes are probed with a white light pulse. Lattice stabilized (singlet) self-trapped excitons are formed within 200 fs which are observed by measuring the stimulated gain in their emission band which decay at 10 ps. The agreement of the photoinduced exciton gain spectrum (<1ps), the transient luminescence spectrum (10 ps) and the steady state luminescence spectrum suggest that the singlet excitons are not further trapped after 200fs of their formation time. Excitation wavelength dependence

  15. 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.

  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. Patients’ Attitudes toward the Donation of Biological Materials for the Derivation of Induced Pluripotent Stem Cells

    PubMed Central

    Dasgupta, Ishan; Bollinger, Juli; Mathews, Debra J.H.; Neumann, Neil M.; Rattani, Abbas; Sugarman, Jeremy

    2016-01-01

    Although academics have raised ethical issues with iPSCs, patients’ perspectives on them and their attitudes toward donating biological materials for iPSC research are unclear. Here, we provide such information to aid in developing policies for consent, collection, and use of biological materials for deriving iPSCs based on patient focus groups. PMID:24388172

  18. Involvement of Nitric Oxide on Bothropoides insularis Venom Biological Effects on Murine Macrophages In Vitro

    PubMed Central

    de Menezes, Ramon R. P. P. B.; Mello, Clarissa P.; Lima, Dânya B.; Tessarolo, Louise D.; Sampaio, Tiago Lima; Paes, Lívia C. F.; Alves, Natacha T. Q.; Assis Junior, Eudmar M.; Lima Junior, Roberto C. P.; Toyama, Marcos H.; Martins, Alice M. C.

    2016-01-01

    Viperidae venom has several local and systemic effects, such as pain, edema, inflammation, kidney failure and coagulopathy. Additionally, bothropic venom and its isolated components directly interfere on cellular metabolism, causing alterations such as cell death and proliferation. Inflammatory cells are particularly involved in pathological envenomation mechanisms due to their capacity of releasing many mediators, such as nitric oxide (NO). NO has many effects on cell viability and it is associated to the development of inflammation and tissue damage caused by Bothrops and Bothropoides venom. Bothropoides insularis is a snake found only in Queimada Grande Island, which has markedly toxic venom. Thus, the aim of this work was to evaluate the biological effects of Bothropoides insularis venom (BiV) on RAW 264.7 cells and assess NO involvement. The venom was submitted to colorimetric assays to identify the presence of some enzymatic components. We observed that BiV induced H2O2 production and showed proteolytic and phospholipasic activities. RAW 264.7 murine macrophages were incubated with different concentrations of BiV and then cell viability was assessed by MTT reduction assay after 2, 6, 12 and 24 hours of incubation. A time- and concentration-dependent effect was observed, with a tendency to cell proliferation at lower BiV concentrations and cell death at higher concentrations. The cytotoxic effect was confirmed after lactate dehydrogenase (LDH) measurement in the supernatant from the experimental groups. Flow cytometry analyses revealed that necrosis is the main cell death pathway caused by BiV. Also, BiV induced NO release. The inhibition of both proliferative and cytotoxic effects with L-NAME were demonstrated, indicating that NO is important for these effects. Finally, BiV induced an increase in iNOS expression. Altogether, these results demonstrate that B. insularis venom have proliferative and cytotoxic effects on macrophages, with necrosis participation

  19. Using near infrared measurement of water content as a cue for detecting biological materials.

    PubMed

    McGunnigle, Gerald

    2012-09-01

    This paper uses the spectral characteristics of water as a cue to detect biological materials in a scene. The spectra of a wide variety of materials were measured; most of the biological materials showed a spectral feature corresponding to the absorption peak of water at 962 nm. A machine vision system that used two narrowband near infrared light sources and a conventional CCD camera is described. The ability of the system to detect biological material is demonstrated in a series of examples. Water content is not an infallible indicator that a material is biological-wet inanimate surfaces will give a false positive, and some tissues are surrounded by highly scattering, impermeable layers that conceal internal water. Nonetheless, in this paper, we will show that many tissues do give a strong response to this feature and dry, nonbiological materials do not. PMID:22945156

  20. A paradigm for the integration of biology in materials science and engineering

    NASA Astrophysics Data System (ADS)

    Roeder, Ryan K.

    2010-07-01

    The integration of biology in materials science and engineering can be complicated by the lack of a common framework and common language between otherwise disparate disciplines. History may offer a valuable lesson as modern materials science and engineering itself resulted from the integration of traditionally disparate disciplines that were delineated by classes of materials. The integration of metallurgy, ceramics, and polymers into materials science and engineering was facilitated, in large part, by a unifying paradigm based upon processing-structure-property relationships that is now well-accepted. Therefore, a common paradigm might also help unify the vast array of perspectives and challenges present in the interdisciplinary study of biomaterials, biological materials, and biomimetic materials. The traditional materials science and engineering paradigm was modified to account for the adaptive and hierarchical nature of biological materials. Various examples of application to research and education are considered.

  1. EFFECT OF HAZARDOUS MATERIAL SPILLS ON BIOLOGICAL TREATMENT PROCESSES

    EPA Science Inventory

    The effects of over 250 chemical substances on biological treatment processes are presented in a format which permits its use as an operations handbook. The information, arranged in a matrix form with the chemical substances presented in alphabetical order, includes descriptions ...

  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. PMID:25491877

  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. PMID:24602907

  4. 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

  5. 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°.

  6. 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.

  7. 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.

  8. 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.

  9. 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. PMID:22486968

  10. 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.

  11. 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)

  12. 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…

  13. 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. PMID:24103844

  14. 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.

  15. Cellular responses to implant materials: biological, physical and chemical factors.

    PubMed

    Kawahara, H

    1983-12-01

    Adhesion of bone and epithelial cells to the dental implant are vital to its retention in alveolar bone and to the prevention of infection via its 'gingival' margin. Studies of cytotoxicity, tissue irritability and carcinogenicity of implantable polymers, metals and ceramics and of tissue adhesion to them have been carried out in tissue culture and in animal experiments. The more similar the polymeric materials are chemically to living tissue the more easily are they dissolved and digested in the host. Therefore, implant materials having a molecular structure similar to protein or polysaccharide, e.g. Nylon, cannot be expected to function. On the other hand, silicones, polyethylene and Teflon (polytetrafluroethylene), which have molecular structures completely different from living substances, are generally more stable in the tissues. However, these polymers are hydrophobic and have little adhesion to living cells in spite of their high stability. They are not, therefore, suitable materials for the construction of implants. Studies on antithrombotic polymers have demonstrated the possibility of creating implantable polymers which have high stability as well as strong adhesion to the surrounding tissues. These properties may be conferred by grafting a hydrophilic polymer on to the surface of a hydrophobic polymer. Of the metals, Ti, Zr and Ta are fairly stable in living tissue, and allow cells to adhere strongly. Alloys of Co-Cr-Mo, Fe-Ni-Cr-Mo, Ti-Al-V, Ti-Mo, Ti-Pd and Ti-Pt deserve to be better evaluated because they are low in density, have high mechanical strength, stability and corrosion resistance in living tissue, and there is direct adhesion to the surrounding tissues. Biodegradable or bioactive ceramics which induce bone formation around the implant do not have sufficient mechanical strength. Implant ceramics have to be stable, e.g. crystal alumina, vitreous carbon, synthetic hydroxypatite and silicon nitrate. These exhibit high biocompatibility and

  16. 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. PMID:16233018

  17. [Issues involved with supply of medical and hygienic materials to home care patients].

    PubMed

    Maeda, Shuko; Mizushima, Yukari; Takiuti, Takako

    2006-12-01

    Questionnaires were mailed to doctors and nurses who are involved in home care to survey their observations on medical and hygienic materials and its supply to home care patients. Some of the survey items, such as problems encountered frequently, areas where an improvement was needed most and concerns that are often raised in suppling of medical and hygienic materials for home care patients, were analyzed by the Berelson's content analysis method to observe problems in suppling adequate medical and hygienic materials. As a result, 5 categories and 17 subcategories were formed. The recognized future issues were: policies concerning support extended to medical organizations and disseminate information of the system, which medical and hygienic materials supplied to home care patients. PMID:17469358

  18. 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.

  19. The Effects of Linear and Modified Linear Programed Materials on the Achievement of Slow Learners in Tenth Grade BSCS Special Materials Biology.

    ERIC Educational Resources Information Center

    Moody, John Charles

    Assessed were the effects of linear and modified linear programed materials on the achievement of slow learners in tenth grade Biological Sciences Curriculum Study (BSCS) Special Materials biology. Two hundred and six students were randomly placed into four programed materials formats: linear programed materials, modified linear program with…

  20. Manipulating lipid bilayer material properties using biologically active amphipathic molecules

    NASA Astrophysics Data System (ADS)

    Ashrafuzzaman, Md; Lampson, M. A.; Greathouse, D. V.; Koeppe, R. E., II; Andersen, O. S.

    2006-07-01

    Lipid bilayers are elastic bodies with properties that can be manipulated/controlled by the adsorption of amphipathic molecules. The resulting changes in bilayer elasticity have been shown to regulate integral membrane protein function. To further understand the amphiphile-induced modulation of bilayer material properties (thickness, intrinsic monolayer curvature and elastic moduli), we examined how an enantiomeric pair of viral anti-fusion peptides (AFPs)—Z-Gly-D-Phe and Z-Gly-Phe, where Z denotes a benzyloxycarbonyl group, as well as Z-Phe-Tyr and Z-D-Phe-Phe-Gly—alters the function of enantiomeric pairs of gramicidin channels of different lengths in planar bilayers. For both short and long channels, the channel lifetimes and appearance frequencies increase as linear functions of the aqueous AFP concentration, with no apparent effect on the single-channel conductance. These changes in channel function do not depend on the chirality of the channels or the AFPs. At pH 7.0, the relative changes in channel lifetimes do not vary when the channel length is varied, indicating that these compounds exert their effects primarily by causing a positive-going change in the intrinsic monolayer curvature. At pH 4.0, the AFPs are more potent than at pH 7.0 and have greater effects on the shorter channels, indicating that these compounds now change the bilayer elastic moduli. When AFPs of different anti-fusion potencies are compared, the rank order of the anti-fusion activity and the channel-modifying activity is similar, but the relative changes in anti-fusion potency are larger than the changes in channel-modifying activity. We conclude that gramicidin channels are useful as molecular force transducers to probe the influence of small amphiphiles upon lipid bilayer material properties.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Insolubilisation of biologically active materials with novel radiation graft copolymers

    NASA Astrophysics Data System (ADS)

    Garnett, J. L.; Jankiewicz, S. V.; Levot, R.; Sangster, D. F.

    The use of radiation grafting to immobilise a typical enzyme, trypsin, is reported. The technique involves radiation grafting to a backbone polymer a monomer containing an appropriate functional group to which the enzyme is bonded. In the present work, p-nitrostyrene has been grafted to representative trunk polymers, polypropylene and PVC, the nitro group in the resulting copolymer converted to the isothiocyanato derivative to which trypsin is attached. Of importance to this insolubilisation process, especially for radiation sensitive backbone polymers, is the inclusion of additives which enhance grafting. A new class of additives which increase the grafting yields is reported using as representative backbone polymers, naturally occurring cellulose and synthetic low density polyethylene. The new additives are specific metal salts such as LiClO 4. The reactivity of these salts in grafting enhancement has been compared with that of mineral acid which has previously been used as an additive to increase grafting yields in both preirradiation and simultaneous techniques. A new model for grafting enhancement in the presence of the metal salts as well as acids is proposed whereby increased grafting yields are attributed to increased partitioning of monomer into the graft region in the presence of ionic solutes. The value of these additives in preparing copolymers suitable for general reagent insolubilisation reactions is discussed.

  3. 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

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

    PubMed

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

    2012-01-01

    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

  5. [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

    2015-01-01

    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. PMID:26667690

  6. Adverse reactions after cosmetic lip augmentation with permanent biologically inert implant materials.

    PubMed

    Hoffmann, C; Schuller-Petrovic, S; Soyer, H P; Kerl, H

    1999-01-01

    Augmentation of lips is a common aesthetic procedure that is mostly performed with alloplastic materials or autologous tissue. Various alloplastic injectable implants have been developed for soft tissue augmentation without surgery. Most biologic materials are resorbed within a few months, fluid silicone may migrate, and autologous fat is not ideal for fine contouring of the lips. The search for a biocompatible, permanent, nontoxic, and biologically inert filler material led to the development of some new materials for subdermal or intradermal implantation. Recently Bioplastique, Artecoll, and Gore-Tex have been well established and recommended by many authors. Although these materials meet most of the characteristics that constitute an ideal injectable prosthetic material, we describe 3 examples of adverse reactions after their implantation into lips. PMID:9922021

  7. 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. PMID:16233011

  8. 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. PMID:27214690

  9. 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.

  10. Tip-enhanced Raman spectroscopy and related techniques in studies of biological materials

    NASA Astrophysics Data System (ADS)

    Schmid, Thomas; Sebesta, Aleksandar; Stadler, Johannes; Opilik, Lothar; Balabin, Roman M.; Zenobi, Renato

    2010-02-01

    Biological materials can be highly heterogeneous at the nanometer scale. The investigation of nanostructures is often hampered by the low spatial resolution (e.g. spectroscopic techniques) or very little chemical information (e.g. atomic force microscopy (AFM), scanning tunneling microscopy (STM)) provided by analytical techniques. Our research focuses on combined instruments, which allow the analysis of the exactly same area of a sample by complementary techniques, such as AFM and Raman spectroscopy. Tip-enhanced Raman spectroscopy (TERS) combines the high spatial resolution of AFM or STM with the chemical information provided by Raman spectroscopy. The technique is based on enhancement effects known from surface-enhanced Raman scattering (SERS). In TERS the enhancing metallic nanostructure is brought to the sample by an AFM or STM tip. With a TERS-active tip, enhanced Raman signals can be generated from a sample area as small as 10-50 nm in diameter. AFM analysis of bacterial biofilms has demonstrated their heterogeneity at the nanometer scale, revealing a variety of nanostructures such as pili, flagella, and extracelullar polymers. TERS measurements of the biopolymers alginate and cytochrome c have yielded spectroscopic fingerprints even of such weak Raman scatterers, which in future can allow their localization in complex matrices. Furthermore, biofilms of the bacterium Halomonas meridiana were studied, which was found to be involved in the generation of the mineral dolomite. Only combined AFM-Raman analysis was able to identify the nanoglobules found in laboratory cultures of H. meridiana as dolomite nanoparticles. Our combined setups are and will be applied to the investigation of biofilms, fish spermatozoa as well as biological membranes.

  11. 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

  12. 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

  13. 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. PMID:23314095

  14. 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.

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

    PubMed

    McDougall, Carmel; Woodcroft, Ben J; Degnan, Bernard M

    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

  16. 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

  17. High-performance liquid chromatographic-fluorescence determination of traces of selenium in biological materials.

    PubMed

    Hawkes, W C; Kutnink, M A

    1996-10-15

    An improved method for the determination of selenium in biological materials has been developed. This work both extends and validates the procedure of Vézina and Bleau (J. Chromatog. 426, 385-391, 1988) which is based on high-performance liquid chromatographic determination of the fluorophore formed by reaction of Se(IV) with 2,3-diaminonaphthalene. The mass detection limit is 48 pg selenium (3 sigma) and the concentration detection limits are 48 parts per trillion in biological fluids and 120 to 480 parts per trillion in dried biological materials. The linear dynamic range of the method has been extended up to approximately 800 ng. Relative standard deviations of 9.4 to 2.7% were observed in repeated analyses of standards in the range of 0.5 to 500 ng. The proposed method was validated with respect to 23 biological reference materials spanning an 1800-fold range of selenium concentrations and was found to be free of significant constant or proportional biases despite greatly different matrix compositions. This method offers an unsurpassed combination of sensitivity, accuracy, linear dynamic range, and freedom from matrix interferences and may be considered a reference method for the reliable determination of selenium in biological materials. PMID:8921189

  18. 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.

  19. 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". PMID:23317522

  20. Melanopsin: a novel photopigment involved in the photoentrainment of the brain's biological clock?

    PubMed

    Hannibal, Jens; Fahrenkrug, Jan

    2002-01-01

    The brain's biological clock located in the suprachiasmatic nucleus (SCN) generates circadian rhythms of physiology and behaviour of approximately 24 hours. The clock needs, however, like a watch that runs too fast or too slow, daily adjustment and the most important stimulus for this adjustment is the environmental light/dark cycle, a process know as photoentrainment. It is well established that the eye contains a separate anatomical and functional system mediating light information to the clock. Until recently, the photopigment responsible for light entrainment of the circadian system has been elusive but recent studies have provided evidence that melanopsin, a recently identified opsin, could be the circadian photopigment. This conclusion is based on the observation that melanopsin is expressed exclusively in retinal ganglion cells projecting to the SCN, a projection known as the retinohypothalamic tract (RHT) and that these ganglion cells are intrinsically photosensitive. Melanopsin is present in the plasma membrane of soma, dendrites and axons forming an extensive photoreceptive network in the entire retina. Although these findings make melanopsin a strong candidate as a circadian photopigment, a number of functional experiments are needed before the role of melanopsin is finally proven. PMID:12452484

  1. The present and future of biologically inspired adhesive interfaces and materials.

    PubMed

    Brubaker, Carrie E; Messersmith, Phillip B

    2012-01-31

    The natural world provides many examples of robust, permanent adhesive platforms. Synthetic adhesive interfaces and materials inspired by mussels of genus Mytulis have been extensively applied, and it is expected that characterization and adaptation of several other biological adhesive strategies will follow the Mytilus edulis model. These candidate species will be introduced, along with a discussion of the adhesive behaviors that make them attractive for synthetic adaptation. While significant progress has been made in the development of biologically inspired adhesive interfaces and materials, persistent questions, current challenges, and emergent areas of research will be also be discussed. PMID:22224862

  2. 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.

  3. 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

  4. 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.

  5. 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 describe a teleoperated mobile robot system being developed at JPL for use by the JPL Fire Department/HAZMAT Team. The project, which began in October 1990, is focused on prototyping a robotic vehicle which can be quickly deployed and easily operated by HAZMAT Team personnel allowing remote entry and exploration of a hazardous material incident site. The close involvement of JPL Fire Department personnel has been critical in establishing system requirements as well as evaluating the system. The current robot, called HAZBOT III, has been especially designed for operation in environments that may contain combustible gases. Testing of the system with the Fire Department has shown that teleoperated robots can successfully gain access to incident sites allowing hazardous material spills to be remotely located and identified. Work is continuing to enable more complex missions through enhancement of the operator interface and by allowing tetherless operation.

  6. 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, the dead fetus or fetal material. 46.206 Section 46.206 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the...

  7. 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, the dead fetus or fetal material. 46.206 Section 46.206 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the...

  8. 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, the dead fetus or fetal material. 46.206 Section 46.206 Public Welfare Department of Health and Human... placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the...

  9. 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, the dead fetus or fetal material. 46.206 Section 46.206 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the...

  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, the dead fetus or fetal material. 46.206 Section 46.206 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... placenta, the dead fetus or fetal material. (a) Research involving, after delivery, the placenta; the...

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

    PubMed

    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

    2014-01-01

    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. PMID:24892285

  12. 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

    2015-01-01

    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

  13. 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

  14. 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. PMID:21994072

  15. 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.

  16. 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. PMID:26176992

  17. Environmental impacts of post-consumer material managements: recycling, biological treatments, incineration.

    PubMed

    Valerio, F

    2010-11-01

    The environmental impacts of recycling, mechanical biological treatments (MBT) and waste-to-energy incineration, the main management strategies to respond to the increasing production of post-consumer materials are reviewed and compared. Several studies carried out according to life-cycle assessment (LCA) confirm that the lowest environmental impact, on a global scale, is obtained by recycling and by biological treatments (composting and anaerobic fermentations) if compost is used in agriculture. The available air emission factors suggest that, on a local scale, mechanical biological treatments with energy recovery of biogas, may be intrinsically safer than waste-to-energy incinerators. Several studies confirm the capability of biological treatments to degrade many toxic xenobiotic contaminating urban wastes such as dioxins and polycyclic aromatic hydrocarbons, an important property to be improved, for safe agricultural use of compost. Further LCA studies to compare the environmental impact of MBTs and of waste-to-energy incinerators are recommended. PMID:20573498

  18. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. 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. PMID:15588058

  1. 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

  2. Enhanced stability and local structure in biologically relevant amorphous materials containing pyrophosphate

    SciTech Connect

    Slater, Colin; Laurencin, Danielle; Burnell, Victoria; Smith, Mark E.; Grover, Liam M.; Hriljac, Joseph A.; Wright, Adrian J.

    2012-10-25

    There is increasing evidence that amorphous inorganic materials play a key role in biomineralisation in many organisms, however the inherent instability of synthetic analogues in the absence of the complex in vivo matrix limits their study and clinical exploitation. To address this, we report here an approach that enhances long-term stability to >1 year of biologically relevant amorphous metal phosphates, in the absence of any complex stabilizers, by utilizing pyrophosphates (P{sub 2}O{sub 7}{sup 4-}); species themselves ubiquitous in vivo. Ambient temperature precipitation reactions were employed to synthesise amorphous Ca{sub 2}P{sub 2}O{sub 7}.nH{sub 2}O and Sr{sub 2}P{sub 2}O{sub 7}.nH{sub 2}O (3.8 < n < 4.2) and their stability and structure were investigated. Pair distribution functions (PDF) derived from synchrotron X-ray data indicated a lack of structural order beyond 8 {angstrom} in both phases, with this local order found to resemble crystalline analogues. Further studies, including {sup 1}H and {sup 31}P solid state NMR, suggest the unusually high stability of these purely inorganic amorphous phases is partly due to disorder in the P-O-P bond angles within the P{sub 2}O{sub 7} units, which impede crystallization, and to water molecules, which are involved in H-bonds of various strengths within the structures and hamper the formation of an ordered network. In situ high temperature powder X-ray diffraction data indicated that the amorphous nature of both phases surprisingly persisted to 450 C. Further NMR and TGA studies found that above ambient temperature some water molecules reacted with P{sub 2}O{sub 7} anions, leading to the hydrolysis of some P-O-P linkages and the formation of HPO{sub 4}{sup 2-} anions within the amorphous matrix. The latter anions then recombined into P{sub 2}O{sub 7} ions at higher temperatures prior to crystallization. Together, these findings provide important new materials with unexplored potential for enzyme

  3. 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

  4. 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.

  5. 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. PMID:26991280

  6. 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. PMID:26500091

  7. Remote time-resolved filament-induced breakdown spectroscopy of biological materials

    NASA Astrophysics Data System (ADS)

    Xu, H. L.; Liu, W.; Chin, S. L.

    2006-05-01

    We report, for what we believe to be the first time, on the feasibility of remote time-resolved filament-induced breakdown spectroscopy (FIBS) of biological materials. The fluorescence from egg white and yeast powder, induced by femtosecond laser pulse filamentation in air, was detected in the backward direction with targets located 3.5 m away from the detection system. The remarkably distinct spectra of egg white and yeast allow us to propose that this technique, time-resolved FIBS, could be potentially useful for remote detection and identification of harmful biological agents.

  8. [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. PMID:12684571

  9. Nanoscale Imaging of Mineral Crystals inside Biological Composite Materials Using X-Ray Diffraction Microscopy

    NASA Astrophysics Data System (ADS)

    Jiang, Huaidong; Ramunno-Johnson, Damien; Song, Changyong; Amirbekian, Bagrat; Kohmura, Yoshiki; Nishino, Yoshinori; Takahashi, Yukio; Ishikawa, Tetsuya; Miao, Jianwei

    2008-01-01

    We for the first time applied x-ray diffraction microscopy to the imaging of mineral crystals inside biological composite materials—intramuscular fish bone—at the nanometer scale resolution. We identified mineral crystals in collagen fibrils at different stages of mineralization. Based on the experimental results and biomineralization analyses, we suggested a dynamic model to account for the nucleation and growth of mineral crystals in the collagen matrix. The results obtained from this study not only further our understanding of the complex structure of bone, but also demonstrate that x-ray diffraction microscopy will become an important tool to study biological materials.

  10. Accidental exposure to biological material in healthcare workers at a university hospital: Evaluation and follow-up of 404 cases.

    PubMed

    Gutierrez, Eliana Battaggia; Lopes, Marta Heloísa; Yasuda, Maria Aparecida Shikanai

    2005-01-01

    The care and follow-up provided to healthcare workers (HCWs) from a large teaching hospital who were exposed to biological material between 1 August 1998 and 31 January 2002 is described here. After exposure, the HCW is evaluated by a nurse and doctor in an emergency consultation and receives follow-up counselling. The collection of 10 ml of blood sample from each HCW and its source patient, when known, is made for immunoenzymatic testing for HIV, HBV and HCV. Evaluation and follow-up of 404 cases revealed that the exposures were concentrated in only a few areas of the hospital; 83% of the HCWs exposed were seen by a doctor responsible for the prophylaxis up to 3 h after exposure. Blood was involved in 76.7% (309) of the exposures. The patient source of the biological material was known in 80.7% (326) of the exposed individuals studied; 80 (24.5%) sources had serological evidence of infection with 1 or more agents: 16.2% were anti-HCV positive, 3.8% were HAgBs positive and 10.9% were anti-HIV positive. 67% (273) of the study population completed the proposed follow-up. No confirmed seroconversion occurred. In conclusion, the observed adherence to the follow-up was quite low, and measures to improve it must be taken. Surprisingly, no difference in adherence to the follow-up was observed among those exposed HCW at risk, i.e. those with an infected or unknown source patient. Analysis of post-exposure management revealed excess prescription of antiretroviral drugs, vaccine and immunoglobulin. Infection by HCV is the most important risk of concern, in our hospital, in accidents with biological material. PMID:15804666

  11. A general framework for application of prestrain to computational models of biological materials.

    PubMed

    Maas, Steve A; Erdemir, Ahmet; Halloran, Jason P; Weiss, Jeffrey A

    2016-08-01

    It is often important to include prestress in computational models of biological tissues. The prestress can represent residual stresses (stresses that exist after the tissue is excised from the body) or in situ stresses (stresses that exist in vivo, in the absence of loading). A prestressed reference configuration may also be needed when modeling the reference geometry of biological tissues in vivo. This research developed a general framework for representing prestress in finite element models of biological materials. It is assumed that the material is elastic, allowing the prestress to be represented via a prestrain. For prestrain fields that are not compatible with the reference geometry, the computational framework provides an iterative algorithm for updating the prestrain until equilibrium is satisfied. The iterative framework allows for enforcement of two different constraints: elimination of distortion in order to address the incompatibility issue, and enforcing a specified in situ fiber strain field while allowing for distortion. The framework was implemented as a plugin in FEBio (www.febio.org), making it easy to maintain the software and to extend the framework if needed. Several examples illustrate the application and effectiveness of the approach, including the application of in situ strains to ligaments in the Open Knee model (simtk.org/home/openknee). A novel method for recovering the stress-free configuration from the prestrain deformation gradient is also presented. This general purpose theoretical and computational framework for applying prestrain will allow analysts to overcome the challenges in modeling this important aspect of biological tissue mechanics. PMID:27131609

  12. PSI:Biology-Materials Repository: A Biologist’s Resource for Protein Expression Plasmids

    PubMed Central

    Cormier, Catherine Y.; Park, Jin G.; Fiacco, Michael; Steel, Jason; Hunter, Preston; Kramer, Jason; Singla, Rajeev; LaBaer, Joshua

    2011-01-01

    The Protein Structure Initiative:Biology-Materials Repository (PSI:Biology-MR; MR; http://psimr.asu.edu) sequence-verifies, annotates, stores, and distributes the protein expression plasmids and vectors created by the Protein Structure Initiative (PSI). The MR has developed an informatics and sample processing pipeline that manages this process for thousands of samples per month from nearly a dozen PSI centers. DNASU (http://dnasu.asu.edu), a freely searchable database, stores the plasmid annotations, which include the full-length sequence, vector information, and associated publications for over 130,000 plasmids created by our laboratory, by the PSI and other consortia, and by individual laboratories for distribution to researchers worldwide. Each plasmid links to external resources, including the PSI Structural Biology Knowledgebase (http://sbkb.org), which facilitates cross-referencing of a particular plasmid to additional protein annotations and experimental data. To expedite and simplify plasmid requests, the MR uses an expedited material transfer agreement (EP-MTA) network, where researchers from network institutions can order and receive PSI plasmids without institutional delays. Currently over 39,000 protein expression plasmids and 78 empty vectors from the PSI are available upon request from DNASU. Overall, the MR’s repository of expression-ready plasmids, its automated pipeline, and the rapid process for receiving and distributing these plasmids more effectively allows the research community to dissect the biological function of proteins whose structures have been studied by the PSI. PMID:21360289

  13. Classification of the biological material with use of FTIR spectroscopy and statistical analysis.

    PubMed

    Bombalska, Aneta; Mularczyk-Oliwa, Monika; Kwaśny, Mirosław; Włodarski, Maksymilian; Kaliszewski, Miron; Kopczyński, Krzysztof; Szpakowska, Małgorzata; Trafny, Elżbieta A

    2011-04-01

    Rapid detection and discrimination of dangerous biological materials such as bacteria and their spores has become a security aim of considerable importance. Various analytical methods, including FTIR spectroscopy combined with statistical analysis have been used to identify vegetative bacteria, bacterial spores and background interferants. The present work discusses the application of FTIR technique performed in reflectance mode using Horizontal Attenuated Total Reflectance accessory (HATR) to the discrimination of biological materials. In comparison with transmission technique the HATR is more rapid and do not require the sample destruction, simultaneously giving similar absorbance bands. HATR-FTIR results combined with statistical analysis PCA and HCA demonstrate that this combination provides novel and accurate microbial identification technique. PMID:21257340

  14. Classification of the biological material with use of FTIR spectroscopy and statistical analysis

    NASA Astrophysics Data System (ADS)

    Bombalska, Aneta; Mularczyk-Oliwa, Monika; Kwaśny, Mirosław; Włodarski, Maksymilian; Kaliszewski, Miron; Kopczyński, Krzysztof; Szpakowska, Małgorzata; Trafny, Elżbieta A.

    2011-04-01

    Rapid detection and discrimination of dangerous biological materials such as bacteria and their spores has become a security aim of considerable importance. Various analytical methods, including FTIR spectroscopy combined with statistical analysis have been used to identify vegetative bacteria, bacterial spores and background interferants. The present work discusses the application of FTIR technique performed in reflectance mode using Horizontal Attenuated Total Reflectance accessory (HATR) to the discrimination of biological materials. In comparison with transmission technique the HATR is more rapid and do not require the sample destruction, simultaneously giving similar absorbance bands. HATR-FTIR results combined with statistical analysis PCA and HCA demonstrate that this combination provides novel and accurate microbial identification technique.

  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. 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

  18. Novel microwave near-field sensors for material characterization, biology, and nanotechnology

    NASA Astrophysics Data System (ADS)

    Joffe, R.; Kamenetskii, E. O.; Shavit, R.

    2013-02-01

    The wide range of interesting electromagnetic behavior of contemporary materials requires that experimentalists working in this field master many diverse measurement techniques and have a broad understanding of condensed matter physics and biophysics. Measurement of the electromagnetic response of materials at microwave frequencies is important for both fundamental and practical reasons. In this paper, we propose a novel near-field microwave sensor with application to material characterization, biology, and nanotechnology. The sensor is based on a subwavelength ferrite-disk resonator with magnetic-dipolar-mode (MDM) oscillations. Strong energy concentration and unique topological structures of the near fields originated from the MDM resonators allow effective measuring material parameters in microwaves, both for ordinary structures and objects with chiral properties.

  19. [Accident with biological material at the prehospital mobile care: reality for health and non-healthcare workers].

    PubMed

    Tipple, Anaclara Ferreira Veiga; Silva, Elisangelo Aparecido Costa; Teles, Sheila Araújo; Mendonça, Katiane Martins; Souza, Adenícia Custódia Silva E; Melo, Dulcelene Sousa

    2013-01-01

    Analytical transversal study that was conducted with the objectives of identifying the prevalence and characterizing the accidents with biological material among professionals in pre-hospital service (PHS) and comparing the risk behaviors adopted by healthcare and non-healthcare groups that can affect the occurrence and seriousness of such accidents. Data were obtained by questionnaire applied to all PHS workers in Goiânia-GO. The study revealed a high prevalence of accidents involving biological material which, although higher for the healthcare group, also affected the non-healthcare group. There were significant (p < 0.05) risk behaviors for these accidents in both groups: not using gloves, masks or eye protectors; inappropriate disposal of sharps; inadequate dress; re-capping of needles; and a lack of immunization against hepatitis B. The results underscore the importance of both groups in adhering to preventive measures, and further point to the need to structure and implement vigilance and control system for this type of accident. PMID:23887787

  20. (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.

  1. 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

  2. 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. PMID:22476786

  3. 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

  4. 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.

  5. 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

  6. Integration of biological data by kernels on graph nodes allows prediction of new genes involved in mitotic chromosome condensation.

    PubMed

    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

    2014-08-15

    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

  7. 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

  8. 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.

  9. Swabs as DNA collection devices for sampling different biological materials from different substrates.

    PubMed

    Verdon, Timothy J; Mitchell, Robert J; van Oorschot, Roland A H

    2014-07-01

    Currently, there is a variety of swabs for collection of biological evidence from crime scenes, but their comparative efficiency is unknown. Here, we report the results of an investigation into the efficiency of different swab types to collect blood, saliva and touch DNA from a range of substrates. The efficiency of extracting blood and saliva from each swab type was also tested. Some swabs were significantly more effective than others for sampling biological materials from different substrates. Swabs with the highest sampling efficiency, however, often did not have the highest extraction efficiency. Observations were recorded regarding practicality of each swab in a variety of situations. Our study demonstrates that selection of sampling device impacts greatly upon successful collection and extraction of DNA. We present guidelines to assist in evaluation of swab choice. PMID:24502761

  10. The Role of Synthetic and Biologic Materials in the Treatment of Pelvic Organ Prolapse

    PubMed Central

    Brown, Ramon A.; Ellis, C. Neal

    2014-01-01

    Pelvic organ prolapse is a significant medical problem that poses a diagnostic and management dilemma. These diseases cause serious morbidity in those affected and treatment is sought for relief of pelvic pain, rectal bleeding, chronic constipation, obstructed defecation, and fecal incontinence. Numerous procedures have been proposed to treat these conditions; however, the search continues as colorectal surgeons attempt to find the procedure that would optimally treat these conditions. The use of prosthetics in the repair of pelvic organ prolapse has become prevalent as the benefits of their use are realized. While advances in biologic mesh and new surgical techniques promise improved functional outcomes with decreased complication rates without de novo symptoms, the debate concerning the best prosthetic material, synthetic or biologic, remains controversial. Furthermore, laparoscopic ventral mesh rectopexy has emerged as a procedure that could potentially fill this role and is rapidly becoming the procedure of choice for the surgical treatment of pelvic organ prolapse. PMID:25435827

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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.

  12. Observation of the freeze-drying process of biological materials with a scanning electron microscope.

    PubMed

    Nei, T; Fujikawa, S

    1976-10-01

    Over the past few decades, numerous studies have been done on the freeze-drying of biological materials from a physical, chemical and biological point of view. Morphological observation of the freeze-drying process of specimens, however, has been tried by only a few investigators. In those studies, thin-layered aqueous specimens, which were sandwiched between two cover slips, were mostly observed with an optical microscope. For ultrastructural and stereoscopic observation, the scanning electron microscope has a great advantage, unlike that of the optical microscope. A specially designed cryo-scanning electron microscope, employed in the present study, made it possible to observe the freezing patterns of the specimens and also the sublimation process of ice in frozen specimens under vacuum. With this specially designed microscope, shrinkage of some specimens due to dehydration during the freeze-drying process was revealed and the extent of such shrinkage was quantitatively determined. PMID:1036327

  13. 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

  14. 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

  15. 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

    2016-07-01

    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. PMID:27281436

  16. Molecular-level engineering of THz/IR-sensitive materials for future biological sensing application

    NASA Astrophysics Data System (ADS)

    Woolard, Dwight; Recine, Gregory; Bykhovski, Alexei; Zhang, Weidong

    2010-08-01

    While the unique spectral information associated with chemical and biological molecules within the terahertz frequency regime (~ 3.0-3.0 millimeters) motivates its use for practical sensing applications, limiting factors at the macroscale (weak spectral absorption, broad line widths and masking geometrical effects introduced by the samples) provides motivation for man-engineered sensing materials that allow for the transduction of the spectral information about target molecules from the nanoscale. This brief letter will overview work being performed by our research group to define molecular-level functionality that will be useful for realizing "THz/IR-sensitive" materials. Here the goal is to define switchable molecular components that when incorporated into larger DNA-based nanoscaffolds lead to THz and/or IR regime electronic and/or photonic material properties that are dictated in a predictable manner by novel functionality paradigms. In particular, theoretical modeling and design studies are being performed to engineer organic and biological switches that can be incorporated into DNA-based architectures that enable the precise extraction of nanoscale information (e.g., composition, dynamics, conformation) through electronic/photonic transformations to the macroscale. Hence, these studies seek to define new spectral-based sensing modalities useful for characterizing bio-molecules

  17. Interpreting atomic force microscopy nanoindentation of hierarchical biological materials using multi-regime analysis.

    PubMed

    Bonilla, M R; Stokes, J R; Gidley, M J; Yakubov, G E

    2015-02-01

    We present a novel Multi-Regime Analysis (MRA) routine for interpreting force indentation measurements of soft materials using atomic force microscopy. The MRA approach combines both well established and semi-empirical theories of contact mechanics within a single framework to deconvolute highly complex and non-linear force-indentation curves. The fundamental assumption in the present form of the model is that each structural contribution to the mechanical response acts in series with other 'mechanical resistors'. This simplification enables interpretation of the micromechanical properties of materials with hierarchical structures and it allows automated processing of large data sets, which is particularly indispensable for biological systems. We validate the algorithm by demonstrating for the first time that the elastic modulus of polydimethylsiloxane (PDMS) films is accurately predicted from both approach and retraction branches of force-indentation curves. For biological systems with complex hierarchical structures, we show the unique capability of MRA to map the micromechanics of live plant cells, revealing an intricate sequence of mechanical deformations resolved with precision that is unattainable using conventional methods of analysis. We recommend the routine use of MRA to interpret AFM force-indentation measurements for other complex soft materials including mammalian cells, bacteria and nanomaterials. PMID:25569139

  18. "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. PMID:27151190

  19. 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.

  20. Health care facility-based decontamination of victims exposed to chemical, biological, and radiological materials.

    PubMed

    Koenig, Kristi L; Boatright, Connie J; Hancock, John A; Denny, Frank J; Teeter, David S; Kahn, Christopher A; Schultz, Carl H

    2008-01-01

    Since the US terrorist attacks of September 11, 2001, concern regarding use of chemical, biological, or radiological weapons is heightened. Many victims of such an attack would present directly to health care facilities without first undergoing field decontamination. This article reviews basic tenets and recommendations for health care facility-based decontamination, including regulatory concerns, types of contaminants, comprehensive decontamination procedures (including crowd control, triage, removal of contaminated garments, cleaning of body contaminants, and management of contaminated materials and equipment), and a discussion of methods to achieve preparedness. PMID:18082785

  1. 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.

  2. Choice of Biological Source Material Supersedes Oxidative Stress in Its Influence on DJ-1 in Vivo Interactions with Hsp90

    PubMed Central

    Knobbe, Christiane B.; Revett, Timothy J.; Bai, Yu; Chow, Vinca; Jeon, Amy Hye Won; Böhm, Christopher; Ehsani, Sepehr; Kislinger, Thomas; Mount, Howard T.; Mak, Tak W.; St. George-Hyslop, Peter; Schmitt-Ulms, Gerold

    2016-01-01

    DJ-1 is a small but relatively abundant protein of unknown function that may undergo stress-dependent cellular translocation and has been implicated in both neurodegenerative diseases and cancer. As such, DJ-1 may be an excellent study object to elucidate the relative influence of the cellular context on its interactome and for exploring whether acute exposure to oxidative stressors alters its molecular environment. Using quantitative mass spectrometry, we conducted comparative DJ-1 interactome analyses from in vivo cross-linked brains or livers and from hydrogen peroxide-treated or naïve embryonic stem cells. The analysis identified a subset of glycolytic enzymes, heat shock proteins 70 and 90, and peroxiredoxins as interactors of DJ-1. Consistent with a role of DJ-1 in Hsp90 chaperone biology, we document destabilization of Hsp90 clients in DJ-1 knockout cells. We further demonstrate the existence of a C106 sulfinic acid modification within DJ-1 and thereby establish that this previously inferred modification also exists in vivo. Our data suggest that caution has to be exerted in interpreting interactome data obtained from a single biological source material and identify a role of DJ-1 as an oxidative stress sensor and partner of a molecular machinery notorious for its involvement in cell fate decisions. PMID:21819105

  3. Simple views on different problems in physics: from drag friction to tough biological materials

    NASA Astrophysics Data System (ADS)

    Okumura, Ko

    2016-03-01

    We discuss the dynamics of bubbles and liquid drops in quasi two dimensions, i.e. in the Hele-Shaw cell, confirming different scaling laws for viscous drag friction, together with scaling laws for a number of related phenomena. Motivated by the study on viscous drag friction, we describe an experiment on drag friction in a granular medium, which reveals a length scale that diverges towards the jamming transition. These examples in the dynamics of viscous fluid and granular materials underscore the importance of the scaling concept in understanding physical phenomena, often vindicated by a clear data collapse by virtue of a corresponding scaling law. To demonstrate the universal usefulness of the strategy, we discuss another different example from the strength of biological materials. To stress a wide applicability of the scaling approach, we introduce the robustness of scaling laws and justify frequent emergence of the robustness.

  4. 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.

  5. Optimization of the Inverse Algorithm for Estimating the Optical Properties of Biological Materials Using Spatially-resolved Diffuse Reflectance Technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of the optical properties from intact biological materials based on diffusion approximation theory is a complicated inverse problem, and it requires proper implementation of inverse algorithm, instrumentation, and experiment. This work was aimed at optimizing the procedure of estimatin...

  6. Removal of lipid soluble process chemicals from biological materials by extraction with naturally occurring oils or synthetic substitutes thereof

    SciTech Connect

    Woods, K.R.; Orme, T.W.

    1988-12-06

    This patent describes a method of removing lipid soluble process chemicals from biological materials comprising blood plasma and fractions thereof containing the lipid soluble process chemicals. The lipid soluble process chemical is a virus attenuating solvent having a high flash point, a detergent, or a mixture thereof. It comprises bringing the biological materials containing the lipid soluble process chemicals into contact with an effective amount of a naturally occurring oil extracted from a plant or an animal or a synthetic compound of similar chemical structure. Also described is a method of removing lymphokine inducing phorbol esters from lympholkine-containing biological material. It comprises bringing the biological materials containing the phorbol esters into contact with an effective amount of a naturally occurring oil extracted from a plant or an animal or a synthetic compound of similar chemical structure so as to remove 80% or more of the phorbol esters.

  7. The exoskeleton of the lobster Homarus americanus as an example of a smart anisotropic biological material.

    PubMed

    Romano, Patricia; Fabritius, Helge; Raabe, Dierk

    2007-05-01

    Many biological materials are composed of fibrils arranged according to well-ordered three-dimensional patterns. These materials often show a strong anisotropy in their properties. An essential characteristic of biological structures is their hierarchical organization from the nanometer to the millimeter scale. Lobster cuticle is a good example of this and a suitable model for studying these properties. In this study the structure of untreated as well as chemically and physically treated cuticle from the exoskeleton of the American lobster (Homarus americanus) was investigated using scanning electron microscopy. Fresh samples have been chemically decalcified and deproteinated and thermally treated to evaluate their resistance to degradation. Results showed that their structure is more complex than the commonly assumed model for arthropod cuticles. Stacked chitin-protein planes create the characteristic twisted plywood pattern found in arthropod cuticles. However, due to a well-developed pore canal system these planes are not simple arrays of parallel chitin-protein fibers. In lobster cuticle, interconnected fibers bend around the continuous lenticellate cavities of the pore canals to form a planar honeycomb-like structure. The chemically and thermally treated samples showed that the organic matrix retains its shape and structure despite the attack of chemical compounds or heat. It was also possible to study the distribution of the biominerals after the removal of the organic matrix. The observed residual structure gives a good impression of how the minerals (mainly calcite) are distributed inside the polymeric network. PMID:17208527

  8. Independent Study of Collegiate Biological Science as a General Education Course: Involving Achievement and Understanding the Processes of Science.

    ERIC Educational Resources Information Center

    Stavick, Lloyd Clair

    The "Test on Understanding Science, Form W" and the "Nelson Biology Test, Form E", were administered before and after a college general biology course to a random selection of students who had chosen to take an individualized study program and to a random group of students who had chosen to follow the lecture-laboratory alternative. There were no…

  9. 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…

  10. 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. PMID:26022547

  11. Method of producing carbon monoxide and hydrogen by gasification of solid carbonaceous material involving microwave irradiation

    SciTech Connect

    Helm, J.L. Jr.

    1984-03-06

    A process is claimed for the gasification of carbon of solid carbonaceous material to form carbon monoxide and hydrogen by contacting the material with superheated steam and irradiating the product of said contacting with an amount of microwave energy sufficient to gasify said carbon, and apparatus therefor.

  12. Femtosecond pulse laser ablation of metallic, semiconducting, ceramic, and biological materials

    NASA Astrophysics Data System (ADS)

    Kautek, Wolfgang; Krueger, Joerg

    1994-09-01

    Production of holes and grooves of < 30 micrometers diameter with high aspect ratio value is a delicate task either for mechanical tools, or for conventional nanosecond pulse lasers like e.g. pulsed Nd:YAG or excimer lasers. They later tend to cause microcracks extending from an annular melting zone, or substantial disruption, respectively. Experimental results are presented which demonstrate that the development of intense ultrashort pulse laser systems (>> 1012 W cm-2, (tau) < 1 ps) opens up possibilities for materials processing by cold plasma generation and ablation of metals, semiconductors, ceramics, composites, and biological materials. A femtosecond and a nanosecond dye laser with pulse durations of 300 fs (< 200 (mu) J) and 7 ns (< 10 mJ), and center wavelengths at 612 and 600 nm, respectively, both focused on an area of the order of 10-5 cm2, have been applied either to absorbing substrates, like polycrystalline gold, silicon (111), aluminum nitride ceramics, or transparent materials, like synthetic and human dental hydroxyapatite composites, bone material, and human cornea transplants. The fs-laser generates its own absorption in transparent materials by a multiphoton absorption process, and thus forces the absorption of visible radiation. Because the time is too short (< ps) for significant transport of mass and energy, the beam interaction generally results in the formation of a thin plasma layer of approximately solid state density. Only after the end of the subpicosecond laser pulse, it expands rapidly away from the surface without any light absorption and further plasma heating. Therefore, energy transfer (heat and impulse) to the target material, and thermal and mechanical disruption are minimized. In contrast to heat- affected zones (HAZ's) generated by conventional nanosecond pulse lasers of the order of 1 - 10 micrometers , HAZ's of less than 0.02 micrometers were observed.

  13. Assembling new technologies at the interface of materials science and biology

    NASA Astrophysics Data System (ADS)

    Stendahl, John C.

    Molecular self-assembly can be used to construct advanced materials by taking cues from nature and harnessing noncovalent interactions. This bottom-up approach affords molecular level precision that can cultivate pathways to improved materials function. The graduate research presented in this thesis integrates molecular self-assembly with traditional concepts in chemistry and materials science, with the ultimate goal of developing innovative solutions in technology and medicine. In the field of polymer engineering, self-assembly was used to create supramolecular nanoribbons that, when incorporated into polystyrene, modify its microstructure and significantly enhance its toughness and ductility. In medicine, self-assembly was used to create ordered, chemically functional materials to improve interactions with cells and other constituents of the biological environment. One system that was investigated is based on a triblock molecule in which cholesterol is connected to a lysine dendron by a flexible oligo-(L-lactic acid) spacer. These molecules self-assemble into polar surface coatings on fibrous poly(L-lactic acid) scaffolds that improve the scaffold's wettability and increase its retention of cells during seeding. Another self-assembling system that was investigated for biomedical applications is a family of molecules referred to as peptide amphiphiles (PA's). PA's consist of hydrophobic alkyl tails connected to short, hydrophilic peptides that incorporate biological signaling epitopes. These molecules spontaneously assemble into networks of well-defined nanofibers in aqueous environments, with the signaling epitopes presented in high density on the nanofiber exteriors. Nanofiber assembly is triggered by charge screening on the peptides and is able to produce self-supporting gels in concentrations of less than 1.0 wt.-%. The assembly process and mechanical properties of PA gels was investigated in detail with vibrational spectroscopy and oscillatory rheology. PA

  14. 25 CFR 170.904 - Who responds to an accident involving a radioactive or hazardous materials shipment?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Who responds to an accident involving a radioactive or hazardous materials shipment? 170.904 Section 170.904 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste Transportation § 170.904 Who...

  15. 25 CFR 170.904 - Who responds to an accident involving a radioactive or hazardous materials shipment?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Who responds to an accident involving a radioactive or hazardous materials shipment? 170.904 Section 170.904 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste Transportation § 170.904...

  16. 25 CFR 170.904 - Who responds to an accident involving a radioactive or hazardous materials shipment?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who responds to an accident involving a radioactive or hazardous materials shipment? 170.904 Section 170.904 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste Transportation § 170.904...

  17. 25 CFR 170.904 - Who responds to an accident involving a radioactive or hazardous materials shipment?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Who responds to an accident involving a radioactive or hazardous materials shipment? 170.904 Section 170.904 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste Transportation § 170.904...

  18. 25 CFR 170.904 - Who responds to an accident involving a radioactive or hazardous materials shipment?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Who responds to an accident involving a radioactive or hazardous materials shipment? 170.904 Section 170.904 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste Transportation § 170.904...

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

    PubMed

    Cabal, Jiri; Bajgar, Jiri; Kassa, Jiri

    2010-09-01

    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. PMID:20188079

  20. 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.

  1. Extraction of proteins and membrane lipids during low temperature embedding of biological material for electron microscopy.

    PubMed

    Weibull, C; Christiansson, A

    1986-04-01

    The extraction of proteins and membrane lipids from biological materials during embedding procedures for electron microscopy carried out at temperatures down to 223 K was studied. Glutaraldehyde-fixed cells of Acholeplasma laidlawii mainly served as test material. More than 99% of the protein and 88% of the lipid of these cells were retained after dehydration with ethanol or acetone between 277 and 223 K and infiltration with methacrylate at 223 K. When methanol was used for dehydration, only 54% of the lipid was retained. The amount of extracted lipid was essentially independent of the ratio between volume of extraction liquid and amount of material subjected to extraction. The cytoplasmic membrane of sectioned Acholeplasma-cells dehydrated and infiltrated as described above appeared more diffuse than that of cells fixed with glutaraldehyde and osmium tetroxide in epoxy resin at room temperature. Glutaraldehyde-fixed erythrocyte ghosts retained 85% of their phospholipid content when dehydrated with ethanol between 277 and 223 K and infiltrated with methacrylate at 223 K. Spinach chloroplasts and thylakoid vesicles retained 61% and 35%, respectively, of their chlorophyll content. PMID:3712423

  2. 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…

  3. 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.

  4. 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.

  5. 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.

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

    DOE PAGESBeta

    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 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

  7. 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

  8. 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. PMID:24018396

  9. 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. PMID:2179310

  10. Alkaline and ultrasonic dissolution of biological materials for trace silicon determination

    PubMed Central

    Viveros, Robert D.; Liberman, Alexander; Trogler, William C.; Kummel, Andrew C.

    2015-01-01

    A simple method for trace elemental determination in biological tissue has been developed. Novel nanomaterials with biomedical applications necessitate the determination of the in vivo fate of the materials to understand their toxicological profile. Hollow iron-doped calcined silica nanoshells have been used as a model to demonstrate that potassium hydroxide and bath sonication at 50 °C can extract elements from alkaline-soluble nanomaterials. After alkali digestion, nitric acid is used to adjust the pH into a suitable range for analysis using techniques such as inductively coupled plasma optical emission spectrometry which require neutral or acidic analytes. In chicken liver phantoms injected with the nanoshells, 96% of the expected silicon concentration was detected. This value was in good agreement with the 94% detection efficiency of nanoshells dissolved in aqueous solution as a control for potential sample matrix interference. Nanoshell detection was further confirmed in a mouse 24 h after intravenous administration; the measured silica above baseline was 35 times greater or more than the standard deviations of the measurements. This method provides a simple and accurate means to quantify alkaline-soluble nanomaterials in biological tissue. PMID:25909037