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Sample records for inorganic chemical biology

  1. Biological and chemical investigation of Allium cepa L. response to selenium inorganic compounds.

    PubMed

    Michalska-Kacymirow, M; Kurek, E; Smolis, A; Wierzbicka, M; Bulska, E

    2014-06-01

    The aim of this study was to evaluate the biological and chemical response of Allium cepa L. exposed to inorganic selenium compounds. Besides the investigation of the total content of selenium as well as its chemical speciation, the Allium test was used to evaluate the growth of onion roots and mitotic activity in the roots' meristem. The total content of selenium was determined by inductively coupled plasma mass spectrometry (ICP MS). High-performance liquid chromatography (HPLC), coupled to ICP MS, was used for the selenium chemical speciation. Results indicated that A. cepa plants are able to biotransform inorganic selenium compounds into their organic derivatives, e.g., Se-methylselenocysteine from the Se(IV) inorganic precursor. Although the differences in the biotransformation of selenium are due mainly to the oxidation state of selenium, the experiment has also shown a fine effect of counter ions (H(+), Na(+), NH4 (+)) on the response of plants and on the specific metabolism of selenium.

  2. Biologically-synthesized inorganic nanomaterials

    NASA Astrophysics Data System (ADS)

    Kramer, Ryan M.; Stone, Morley O.; Naik, Rajesh R.

    2004-06-01

    A hallmark of biological systems is their ability to self-assemble. This self-assembly can occur on the molecular, macromolecular and mesoscale. In this work, we have chosen to exploit biology's ability to self-assemble by incorporating additional functionality within the final structure. Our research efforts have been directed at not only understanding how biological organisms control nucleation and growth of inorganic materials, but also how this activity can be controlled in vitro. In previous work, we have demonstrated how peptides can be selected from a combinatorial library that possesses catalytic activity with respect to inorganic nucleation and deposition. We have engineered some of these peptide sequences into self-assembling protein structures. The goal of the project was to create an organic/inorganic hybrid that retained the "memory" properties of the organic, but possessed the superior optical and electronic properties of the inorganic.

  3. Spectroscopic elucidation of energy transfer in hybrid inorganic-biological organisms for solar-to-chemical production.

    PubMed

    Kornienko, Nikolay; Sakimoto, Kelsey K; Herlihy, David M; Nguyen, Son C; Alivisatos, A Paul; Harris, Charles B; Schwartzberg, Adam; Yang, Peidong

    2016-10-18

    The rise of inorganic-biological hybrid organisms for solar-to-chemical production has spurred mechanistic investigations into the dynamics of the biotic-abiotic interface to drive the development of next-generation systems. The model system, Moorella thermoacetica-cadmium sulfide (CdS), combines an inorganic semiconductor nanoparticle light harvester with an acetogenic bacterium to drive the photosynthetic reduction of CO2 to acetic acid with high efficiency. In this work, we report insights into this unique electrotrophic behavior and propose a charge-transfer mechanism from CdS to M. thermoacetica Transient absorption (TA) spectroscopy revealed that photoexcited electron transfer rates increase with increasing hydrogenase (H2ase) enzyme activity. On the same time scale as the TA spectroscopy, time-resolved infrared (TRIR) spectroscopy showed spectral changes in the 1,700-1,900-cm(-1) spectral region. The quantum efficiency of this system for photosynthetic acetic acid generation also increased with increasing H2ase activity and shorter carrier lifetimes when averaged over the first 24 h of photosynthesis. However, within the initial 3 h of photosynthesis, the rate followed an opposite trend: The bacteria with the lowest H2ase activity photosynthesized acetic acid the fastest. These results suggest a two-pathway mechanism: a high quantum efficiency charge-transfer pathway to H2ase generating H2 as a molecular intermediate that dominates at long time scales (24 h), and a direct energy-transducing enzymatic pathway responsible for acetic acid production at short time scales (3 h). This work represents a promising platform to utilize conventional spectroscopic methodology to extract insights from more complex biotic-abiotic hybrid systems.

  4. Peptide B12: emerging trends at the interface of inorganic chemistry, chemical biology and medicine.

    PubMed

    Zelder, Felix; Zhou, Kai; Sonnay, Marjorie

    2013-01-28

    The sophisticated and efficient delivery of vitamin B(12) ("B(12)") into cells offers promise for B(12)-bioconjugates in medicinal diagnosis and therapy. It is therefore surprising that rather little attention is presently paid to an alternative strategy in drug design: the development of structurally perfect, but catalytically inactive semi-artificial B(12) surrogates. Vitamin B(12) cofactors catalyse important biological transformations and are indispensible for humans and most other forms of life. This strong metabolic dependency exhibits enormous medicinal opportunities. Inhibitors of B(12) dependent enzymes are potential suppressors of fast proliferating cancer cells. This perspective article focuses on the design and study of backbone modified B(12) derivatives, particularly on peptide B(12) derivatives. Peptide B(12) is a recently introduced class of biomimetic cobalamins bearing an artificial peptide backbone with adjustable coordination and redox-properties. Pioneering biological studies demonstrated reduced catalytic activity, combined with inhibitory potential that is encouraging for future efforts in turning natural cofactors into new anti-proliferative agents.

  5. Inorganic chemically active adsorbents (ICAAs)

    SciTech Connect

    Ally, M.R.; Tavlarides, L.

    1997-10-01

    Oak Ridge National Laboratory (ORNL) researchers are developing a technology that combines metal chelation extraction technology and synthesis chemistry. They begin with a ceramic substrate such as alumina, titanium oxide or silica gel because they provide high surface area, high mechanical strength, and radiolytic stability. One preparation method involves silylation to hydrophobize the surface, followed by chemisorption of a suitable chelation agent using vapor deposition. Another route attaches newly designed chelating agents through covalent bonding by the use of coupling agents. These approaches provide stable and selective, inorganic chemically active adsorbents (ICAAs) tailored for removal of metals. The technology has the following advantages over ion exchange: (1) higher mechanical strength, (2) higher resistance to radiation fields, (3) higher selectivity for the desired metal ion, (4) no cation exchange, (5) reduced or no interference from accompanying anions, (6) faster kinetics, and (7) easy and selective regeneration. Target waste streams include metal-containing groundwater/process wastewater at ORNL`s Y-12 Plant (multiple metals), Savannah River Site (SRS), Rocky Flats (multiple metals), and Hanford; aqueous mixed wastes at Idaho National Engineering Laboratory (INEL); and scrubber water generated at SRS and INEL. Focus Areas that will benefit from this research include Mixed Waste, and Subsurface Contaminants.

  6. Computational Systems Chemical Biology

    PubMed Central

    Oprea, Tudor I.; May, Elebeoba E.; Leitão, Andrei; Tropsha, Alexander

    2013-01-01

    There is a critical need for improving the level of chemistry awareness in systems biology. The data and information related to modulation of genes and proteins by small molecules continue to accumulate at the same time as simulation tools in systems biology and whole body physiologically-based pharmacokinetics (PBPK) continue to evolve. We called this emerging area at the interface between chemical biology and systems biology systems chemical biology, SCB (Oprea et al., 2007). The overarching goal of computational SCB is to develop tools for integrated chemical-biological data acquisition, filtering and processing, by taking into account relevant information related to interactions between proteins and small molecules, possible metabolic transformations of small molecules, as well as associated information related to genes, networks, small molecules and, where applicable, mutants and variants of those proteins. There is yet an unmet need to develop an integrated in silico pharmacology / systems biology continuum that embeds drug-target-clinical outcome (DTCO) triplets, a capability that is vital to the future of chemical biology, pharmacology and systems biology. Through the development of the SCB approach, scientists will be able to start addressing, in an integrated simulation environment, questions that make the best use of our ever-growing chemical and biological data repositories at the system-wide level. This chapter reviews some of the major research concepts and describes key components that constitute the emerging area of computational systems chemical biology. PMID:20838980

  7. Computational systems chemical biology.

    PubMed

    Oprea, Tudor I; May, Elebeoba E; Leitão, Andrei; Tropsha, Alexander

    2011-01-01

    There is a critical need for improving the level of chemistry awareness in systems biology. The data and information related to modulation of genes and proteins by small molecules continue to accumulate at the same time as simulation tools in systems biology and whole body physiologically based pharmacokinetics (PBPK) continue to evolve. We called this emerging area at the interface between chemical biology and systems biology systems chemical biology (SCB) (Nat Chem Biol 3: 447-450, 2007).The overarching goal of computational SCB is to develop tools for integrated chemical-biological data acquisition, filtering and processing, by taking into account relevant information related to interactions between proteins and small molecules, possible metabolic transformations of small molecules, as well as associated information related to genes, networks, small molecules, and, where applicable, mutants and variants of those proteins. There is yet an unmet need to develop an integrated in silico pharmacology/systems biology continuum that embeds drug-target-clinical outcome (DTCO) triplets, a capability that is vital to the future of chemical biology, pharmacology, and systems biology. Through the development of the SCB approach, scientists will be able to start addressing, in an integrated simulation environment, questions that make the best use of our ever-growing chemical and biological data repositories at the system-wide level. This chapter reviews some of the major research concepts and describes key components that constitute the emerging area of computational systems chemical biology.

  8. The biological inorganic chemistry of zinc ions.

    PubMed

    Krężel, Artur; Maret, Wolfgang

    2016-12-01

    The solution and complexation chemistry of zinc ions is the basis for zinc biology. In living organisms, zinc is redox-inert and has only one valence state: Zn(II). Its coordination environment in proteins is limited by oxygen, nitrogen, and sulfur donors from the side chains of a few amino acids. In an estimated 10% of all human proteins, zinc has a catalytic or structural function and remains bound during the lifetime of the protein. However, in other proteins zinc ions bind reversibly with dissociation and association rates commensurate with the requirements in regulation, transport, transfer, sensing, signalling, and storage. In contrast to the extensive knowledge about zinc proteins, the coordination chemistry of the "mobile" zinc ions in these processes, i.e. when not bound to proteins, is virtually unexplored and the mechanisms of ligand exchange are poorly understood. Knowledge of the biological inorganic chemistry of zinc ions is essential for understanding its cellular biology and for designing complexes that deliver zinc to proteins and chelating agents that remove zinc from proteins, for detecting zinc ion species by qualitative and quantitative analysis, and for proper planning and execution of experiments involving zinc ions and nanoparticles such as zinc oxide (ZnO). In most investigations, reference is made to zinc or Zn(2+) without full appreciation of how biological zinc ions are buffered and how the d-block cation Zn(2+) differs from s-block cations such as Ca(2+) with regard to significantly higher affinity for ligands, preference for the donor atoms of ligands, and coordination dynamics. Zinc needs to be tightly controlled. The interaction with low molecular weight ligands such as water and inorganic and organic anions is highly relevant to its biology but in contrast to its coordination in proteins has not been discussed in the biochemical literature. From the discussion in this article, it is becoming evident that zinc ion speciation is

  9. Inorganic chemical precipitate formation payload design

    NASA Technical Reports Server (NTRS)

    Friedrich, Craig

    1988-01-01

    The Get Away Special payload to investigate the formation of inorganic precipitates (G-405) utilizes six transparent chemical reaction chambers to actively mix a dry powder with a liquid solution. At predetermined intervals the progress of the precipitate formation is photographed and stored as data. The precipitate particles will also be subject to post-flight analysis. The various tasks performed during the 14 hour duration of the experiment are initiated and monitored by a custom-built digital controller. The payload is currently scheduled as a backup payload for STS-29 with a possible launch date of January, 1989.

  10. Biological and Chemical Security

    SciTech Connect

    Fitch, P J

    2002-12-19

    The LLNL Chemical & Biological National Security Program (CBNP) provides science, technology and integrated systems for chemical and biological security. Our approach is to develop and field advanced strategies that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical or biological weapons. Recent events show the importance of civilian defense against terrorism. The 1995 nerve gas attack in Tokyo's subway served to catalyze and focus the early LLNL program on civilian counter terrorism. In the same year, LLNL began CBNP using Laboratory-Directed R&D investments and a focus on biodetection. The Nunn-Lugar-Domenici Defense Against Weapons of Mass Destruction Act, passed in 1996, initiated a number of U.S. nonproliferation and counter-terrorism programs including the DOE (now NNSA) Chemical and Biological Nonproliferation Program (also known as CBNP). In 2002, the Department of Homeland Security was formed. The NNSA CBNP and many of the LLNL CBNP activities are being transferred as the new Department becomes operational. LLNL has a long history in national security including nonproliferation of weapons of mass destruction. In biology, LLNL had a key role in starting and implementing the Human Genome Project and, more recently, the Microbial Genome Program. LLNL has over 1,000 scientists and engineers with relevant expertise in biology, chemistry, decontamination, instrumentation, microtechnologies, atmospheric modeling, and field experimentation. Over 150 LLNL scientists and engineers work full time on chemical and biological national security projects.

  11. Chemical and Biological Kinetics

    NASA Astrophysics Data System (ADS)

    Emanuel', N. M.

    1981-10-01

    Examples of the application of the methods and ideas of chemical kinetics in various branches of chemistry and biology are considered and the results of studies on the kinetics and mechanisms of autoxidation and inhibited and catalysed oxidation of organic substances in the liquid phase are surveyed. Problems of the kinetics of the ageing of polymers and the principles of their stabilisation are discussed and certain trends in biological kinetics (kinetics of tumour growth, kinetic criteria of the effectiveness of chemotherapy, problems of gerontology, etc.) are considered. The bibliography includes 281 references.

  12. Morphology-preserving chemical conversion of bioorganic and inorganic templates

    NASA Astrophysics Data System (ADS)

    Vernon, Jonathan Paul

    The generation of nanostructured assemblies with complex (three-dimensional, 3D) self-assembled morphologies and with complex (multicomponent) tailorable inorganic compositions is of considerable technological and scientific interest. This dissertation demonstrates self-assembled 3D organic templates of biogenic origin can be converted into replicas comprised of numerous other functional nanocrystalline inorganic materials. Nature provides a spectacular variety of biologically-assembled 3D organic structures with intricate, hierarchical (macro-to-micro-to-nanoscale) morphologies. Such processing on readily-available structurally complex templates provides a framework for chemical conversion of synthetic organic templates and, potentially, production of organic/inorganic composites. Four specific research thrusts are detailed in this document. First, chemical conversion of a nanostructured bioorganic template into a multicomponent oxide compound (tetragonal BaTiO3) via SSG coating and subsequent morphology-preserving microwave hydrothermal processing is demonstrated. Second, morphology-preserving chemical conversion of bioorganic templates into hierarchical photoluminescent microparticles is demonstrated to reveal both the dramatic change in properties such processing can provide, and the potential utility of chemically transformed templates in anti-counterfeiting / authentication applications. Third, determination of the reaction mechanism(s) for morphology-preserving microwave hydrothermal conversion of TiO2 to BaTiO3, through Au inert markers on single crystal rutile titania, is detailed. Finally, utilization of constructive coating techniques (SSG) and moderate temperature (< 500°C) heat treatments to modify and replicate structural color is coupled with deconstructive focused ion beam microsurgery to prepare samples for microscale structure interrogation. Specifically, the effects of coating thickness and composition on reflection spectra of structurally

  13. Insights into biogenic and chemical production of inorganic nanomaterials and nanostructures.

    PubMed

    Faramarzi, Mohammad Ali; Sadighi, Armin

    2013-03-01

    The synthesis of inorganic nanomaterials and nanostructures by the means of diverse physical, chemical, and biological principles has been developed in recent decades. The nanoscale materials and structures creation continue to be an active area of researches due to the exciting properties of the resulting nanomaterials and their innovative applications. Despite physical and chemical approaches which have been used for a long time to produce nanomaterials, biological resources as green candidates that can replace old production methods have been focused in recent years to generate various inorganic nanoparticles (NPs) or other nanoscale structures. Cost-effective, eco-friendly, energy efficient, and nontoxic produced nanomaterials using diverse biological entities have been received increasing attention in the last two decades in contrast to physical and chemical methods owe using toxic solvents, generate unwanted by-products, and high energy consumption which restrict the popularity of these ways employed in nanometric science and engineering. In this review, the biosynthesis of gold, silver, gold-silver alloy, magnetic, semiconductor nanocrystals, silica, zirconia, titania, palladium, bismuth, selenium, antimony sulfide, and platinum NPs, using bacteria, actinomycetes, fungi, yeasts, plant extracts and also informational bio-macromolecules including proteins, polypeptides, DNA, and RNA have been reported extensively to mention the current status of the biological inorganic nanomaterial production. In other hand, two well-known wet chemical techniques, namely chemical reduction and sol-gel methods, used to produce various types of nanocrystalline powders, metal oxides, and hybrid organic-inorganic nanomaterials have presented.

  14. Approaches to chemical synthetic biology.

    PubMed

    Chiarabelli, Cristiano; Stano, Pasquale; Anella, Fabrizio; Carrara, Paolo; Luisi, Pier Luigi

    2012-07-16

    Synthetic biology is first represented in terms of two complementary aspects, the bio-engineering one, based on the genetic manipulation of extant microbial forms in order to obtain forms of life which do not exist in nature; and the chemical synthetic biology, an approach mostly based on chemical manipulation for the laboratory synthesis of biological structures that do not exist in nature. The paper is mostly devoted to shortly review chemical synthetic biology projects currently carried out in our laboratory. In particular, we describe: the minimal cell project, then the "Never Born Proteins" and lastly the Never Born RNAs. We describe and critically analyze the main results, emphasizing the possible relevance of chemical synthetic biology for the progress in basic science and biotechnology.

  15. Synthetic Biology for Specialty Chemicals.

    PubMed

    Markham, Kelly A; Alper, Hal S

    2015-01-01

    In this review, we address recent advances in the field of synthetic biology and describe how those tools have been applied to produce a wide variety of chemicals in microorganisms. Here we classify the expansion of the synthetic biology toolbox into three different categories based on their primary function in strain engineering-for design, for construction, and for optimization. Next, focusing on recent years, we look at how chemicals have been produced using these new synthetic biology tools. Advances in producing fuels are briefly described, followed by a more thorough treatment of commodity chemicals, specialty chemicals, pharmaceuticals, and nutraceuticals. Throughout this review, an emphasis is placed on how synthetic biology tools are applied to strain engineering. Finally, we discuss organism and host strain diversity and provide a future outlook in the field.

  16. The aesthetics of chemical biology.

    PubMed

    Parsons, Glenn

    2012-12-01

    Scientists and philosophers have long reflected on the place of aesthetics in science. In this essay, I review these discussions, identifying work of relevance to chemistry and, in particular, to the field of chemical biology. Topics discussed include the role of aesthetics in scientific theory choice, the aesthetics of molecular images, the beauty-making features of molecules, and the relation between the aesthetics of chemical biology and the aesthetics of industrial design.

  17. Organic/Inorganic Hybrid Nanostructures for Chemical Plasmonic Sensors

    NASA Astrophysics Data System (ADS)

    Chang, Sehoon

    2011-12-01

    The work presented in this dissertation suggests novel design of chemical plasmonic sensors which have been developed based on Localized Surface Plasmon Resonance (LSPR), and Surface-enhanced Raman scattering (SERS) phenomena. The goal of the study is to understand the SERS phenomena for 3D hybrid (organic/inorganic) templates and to design of the templates for trace-level detection of selected chemical analytes relevant to liquid explosives and hazardous chemicals. The key design criteria for the development of the SERS templates are utilizing selective polymeric nanocoatings within cylindrical nanopores for promoting selective adsorption of chemical analyte molecules, maximizing specific surface area, and optimizing concentration of hot spots with efficient light interaction inside nanochannels. The organic/inorganic hybrid templates are optimized through a comprehensive understanding of the LSPR properties of the gold nanoparticles, gold nanorods, interaction of light with highly porous alumina template, and the choice of physical and chemical attributes of the selective coating. Furthermore, novel method to assemble silver nanoparticles in 3D as the active SERS-active substrate has been demonstrated by uniform, in situ growth of silver nanoparticles from electroless deposited silver seeds excluding any adhesive polymer layer on template. This approach can be the optimal for SERS sensing applications because it is not necessary to separate the Raman bands of the polyelectrolyte binding layer from those of the desired analyte. The fabrication method is an efficient, simple and fast way to assemble nanoparticles into 3D nanostructures. Addressable Raman markers from silver nanowire crossbars with silver nanoparticles are also introduced and studied. Assembly of silver nanowire crossbar structure is achieved by simple, double-step capillary transfer lithography. The on/off SERS properties can be observed on silver nanowire crossbars with silver nanoparticles

  18. Remote Raman Spectroscopic Detection of Inorganic, Organic and Biological Materials to 100 m and More

    NASA Astrophysics Data System (ADS)

    Sharma, Shiv K.; Misra, Anupam K.

    2008-11-01

    We have designed and tested a portable gated-Raman system that is capable of detecting organic and inorganic bulk chemicals over stand-off distances of 100 m and more during day and night time. Utilizing a 532 nm laser pulse (~35 mJ/pulse), Raman spectra of several organic and inorganic compounds have been measured with the portable Raman instrument over a distance of 100 m. Remote Raman spectra, obtained with a very short gate (2 micro second), from a variety of inorganic minerals such as calcite (CaCO3), α-quartz (α-SiO2), barite (BaSO4), and FeSO4.7H2O, and organic compounds such as acetone, methanol, 2-propanol and naphthalene showed all major bands required for unambiguous chemical identification. We also measured the Raman and fluorescence spectra of plant leaves, tomato, and chicken eggshell excited with a 532 nm, 20 Hz pulsed laser and accumulated over 200 laser shots (10-s integration time) at 110 m with good signal-to-noise ratio. The results of these investigations show that remote Raman spectroscopy over a distance of 100 m can be used to identify Raman fingerprints of both inorganic, organic, and some biological compounds on planetary surfaces and could be useful for environmental monitoring.

  19. Environmental and biological monitoring of workers exposed to inorganic lead.

    PubMed

    De Medinilla, J; Espigares, M

    1991-01-01

    A total of 20 workers who were exposed to inorganic lead in two local firms (M and N) were studied. Lead concentrations in the air (PbA) at firm M exceeded the threshold limit value (TLV) of 0.150 mg/m3 established by Spanish and EC legislation, while atmospheric lead at firm N exceeded the action level of 0.075 mg/m3. In the same population, biological exposure indices (BEI) were also determined; these included lead in whole blood (PbB), erythrocyte activity of aminolevulinic acid (ALA-D), urinary excretion of aminolevulinic acid (ALA-U) and zinc protoporphyrin (ZPP). The relationship between the exposure parameters (PbA, PbB) and the biological activity indices (ALA-D, ALA-U, ZPP) were analysed statistically in order to obtain levels of significance, coefficients of correlation and regression equations. The high coefficients of correlation found confirm the usefulness of BEI in evaluating exposure to lead fumes and lead dust.

  20. Chemically diverse and multifunctional hybrid organic-inorganic perovskites

    NASA Astrophysics Data System (ADS)

    Li, Wei; Wang, Zheming; Deschler, Felix; Gao, Song; Friend, Richard H.; Cheetham, Anthony K.

    2017-02-01

    Hybrid organic-inorganic perovskites (HOIPs) can have a diverse range of compositions including halides, azides, formates, dicyanamides, cyanides and dicyanometallates. These materials have several common features, including their classical ABX3 perovskite architecture and the presence of organic amine cations that occupy the A-sites. Current research in HOIPs tends to focus on metal halide HOIPs, which show promise for use in solar cells and optoelectronic devices; however, the other subclasses also exhibit a diverse range of physical properties. In this Review, we summarize the chemical variability and structural diversity of all known HOIP subclasses. We also present a comprehensive account of their intriguing physical properties, including photovoltaic and optoelectronic properties, dielectricity, magnetism, ferroelectricity, ferroelasticity and multiferroicity. Moreover, we discuss the current challenges and future opportunities in this exciting field.

  1. Chemical form matters: differential accumulation of mercury following inorganic and organic mercury exposures in zebrafish larvae.

    PubMed

    Korbas, Malgorzata; Macdonald, Tracy C; Pickering, Ingrid J; George, Graham N; Krone, Patrick H

    2012-02-17

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versusl-cysteine). For inorganic mercury species, in absence of l-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with l-cysteine present in the treatment solution, mercuric bis-l-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  2. Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

    SciTech Connect

    Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H.

    2013-04-08

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  3. Biological effects of inorganic phosphate: potential signal of toxicity.

    PubMed

    Hong, Seong-Ho; Park, Sung-Jin; Lee, Somin; Kim, Sanghwa; Cho, Myung-Haing

    2015-02-01

    Inorganic phosphate (Pi) plays crucial roles in several biological processes and signaling pathways. Pi uptake is regulated by sodium-dependent phosphate (Na/Pi) transporters (NPTs). Moreover, Pi is used as a food additive in food items such as sausages, crackers, dairy products, and beverages. However, the high serum concentration of phosphate (> 5.5 mg/dL) can cause adverse renal effects, cardiovascular effects including vascular or valvular calcification, and stimulate bone resorption. In addition, Pi can also alter vital cellular signaling, related to cell growth and cap-dependent protein translation. Moreover, intake of dietary Pi, whether high (1.0%) or low (0.1%), affects organs in developing mice, and is related to tumorigenesis in mice. The recommended dietary allowance (RDA) of Pi is the daily dietary intake required to maintain levels above the lower limit of the range of normal serum Pi concentration (2.7 mg/dL) for most individuals (97-98%). Thus, adequate intake of Pi (RDA; 700 mg/day) and maintenance of normal Pi concentration (2.7-4.5 mg/dL) are important for health and prevention of diseases caused by inadequate Pi intake.

  4. Inorganic concepts relevant to metal binding, activity, and toxicity in a biological system

    SciTech Connect

    Hoeschele, J.D. . Parke-Davis Pharmaceutical Research Div.); Turner, J.E.; England, M.W. )

    1990-01-01

    The purpose of this paper is to review selected physical and inorganic concepts and factors which might be important in assessing and/or understanding the fact and disposition of a metal system in a biological environment. Hopefully, such inquiries will ultimately permit us to understand, rationalize, and predict differences and trends in biological effects as a function of the basic nature of a metal system and, in optimal cases, serve as input to a system of guidelines for the notion of Chemical Dosimetry.'' The plan of this paper is to first review, in general terms, the basic principles of the Crystal Field Theory (CFT), a unifying theory of bonding in metal complexes. This will provide the necessary theoretical background for the subsequent discussion of selected concepts and factors. 21 refs., 7 figs., 6 tabs.

  5. Questions and Answers for Reporting for the 2006 Partial Updating of the TSCA Chemical Inventory Database: Inorganic Chemicals Addendum

    EPA Pesticide Factsheets

    This document addresses specific questions related to reporting inorganic chemicals under the IUR and is an addendum to the Questions and Answers for Reporting for the 2006 Partial Updating of the TSCA Chemical Inventory Database (Questions and Answers Document).

  6. PHOTOELECTROCHEMISTRY AND PHOTOCATALYSIS IN NANOSCALE INORGANIC CHEMICAL SYSTEMS

    SciTech Connect

    Thomas E. Mallouk

    2007-05-27

    The goal of our DOE-supported research has been to explore the use of solid state materials as organizing media for, and as active components of, artificial photosynthetic systems. In this work we strive to understand how photoinduced electron and energy transfer reactions occur in the solid state, and to elucidate design principles for using nanoscale inorganic materials in photochemical energy conversion schemes. A unifying theme in this project has been to move beyond the study of simple transient charge separation to integrated chemical systems that can effect permanent charge separation in the form of energy-rich chemicals. This project explored the use of zeolites as organizing media for electron donor-acceptor systems and artificial photosynthetic assemblies. Layer-by-layer synthetic methods were developed using lamellar semiconductors, and multi-step, visible light driven energy/electron transfer cascades were studied by transient specroscopic techniques. By combining molecular photosensitizers with lamellar semiconductors and intercalated catalyst particles, the first non-sacrificial systems for visible light driven hydrogen evolution were developed and studied. Oxygen evolving catalyst particles and semiconductor nanowires were also studied with the goal of achieving photocatalytic water splitting using visible light.

  7. Nanoscale chemical tomography of buried organic-inorganic interfaces in the chiton tooth.

    PubMed

    Gordon, Lyle M; Joester, Derk

    2011-01-13

    Biological organisms possess an unparalleled ability to control the structure and properties of mineralized tissues. They are able, for example, to guide the formation of smoothly curving single crystals or tough, lightweight, self-repairing skeletal elements. In many biominerals, an organic matrix interacts with the mineral as it forms, controls its morphology and polymorph, and is occluded during mineralization. The remarkable functional properties of the resulting composites-such as outstanding fracture toughness and wear resistance-can be attributed to buried organic-inorganic interfaces at multiple hierarchical levels. Analysing and controlling such interfaces at the nanometre length scale is critical also in emerging organic electronic and photovoltaic hybrid materials. However, elucidating the structural and chemical complexity of buried organic-inorganic interfaces presents a challenge to state-of-the-art imaging techniques. Here we show that pulsed-laser atom-probe tomography reveals three-dimensional chemical maps of organic fibres with a diameter of 5-10 nm in the surrounding nano-crystalline magnetite (Fe(3)O(4)) mineral in the tooth of a marine mollusc, the chiton Chaetopleura apiculata. Remarkably, most fibres co-localize with either sodium or magnesium. Furthermore, clustering of these cations in the fibre indicates a structural level of hierarchy previously undetected. Our results demonstrate that in the chiton tooth, individual organic fibres have different chemical compositions, and therefore probably different functional roles in controlling fibre formation and matrix-mineral interactions. Atom-probe tomography is able to detect this chemical/structural heterogeneity by virtue of its high three-dimensional spatial resolution and sensitivity across the periodic table. We anticipate that the quantitative analysis and visualization of nanometre-scale interfaces by laser-pulsed atom-probe tomography will contribute greatly to our understanding not

  8. Diffusion of inorganic chemical species in compacted clay soil

    NASA Astrophysics Data System (ADS)

    Shackelford, Charles D.; Daniel, David E.; Liljestrand, Howard M.

    1989-08-01

    This research was conducted to study the diffusion of inorganic chemicals in compacted clay soil for the design of waste containment barriers. The effective diffusion coefficients ( D ∗) of anionic (Cl -, Br -, and I -) and cationic (K +, Cd 2+, and Zn 2+) species in a synthetic leachate were measured. Two clay soils were used in the study. The soils were compacted and pre-soaked to minimize mass transport due to suction in the soil. The results of the diffusion tests were analyzed using two analytical solutions to Fick's second law and a commercially available semi-analytical solution, POLLUTE 3.3. Mass balance calculations were performed to indicate possible sinks/sources in the diffusion system. Errors in mass balance were attributed to problems with the chemical analysis (I -), the inefficiency of the extraction procedure (K +), precipitation (Cd 2+ and Zn 2+), and chemical complexation (Cl - and Br -). The D ∗ values for Cl - reported in this study are in excellent agreement with previous findings for other types of soil. The D ∗ values for the metals (K +, Cd 2+, and Zn 2+) are thought to be high (conservative) due to: (1) Ca 2+ saturation of the exchange complex of the clays; (2) precipitation of Cd 2+ and Zn 2+; and (3) nonlinear adsorption behavior. In general, high D ∗ values and conservative designs of waste containment barriers will result if the procedures described in this study are used to determine D ∗ and the adsorption behavior of the solutes is similar to that described in this study.

  9. Biological monitoring of occupational exposure to inorganic arsenic

    PubMed Central

    Apostoli, P.; Bartoli, D.; Alessio, L.; Buchet, J. P.

    1999-01-01

    OBJECTIVES: This study was undertaken to assess reliable biological indicators for monitoring the occupational exposure to inorganic arsenic (iAs), taking into account the possible confounding role of arsenicals present in food and of the element present in drinking water. METHODS: 51 Glass workers exposed to As trioxide were monitored by measuring dust in the breathing zone, with personal air samplers. Urine samples at the end of work shift were analysed for biological monitoring. A control group of 39 subjects not exposed to As, and eight volunteers who drank water containing about 45 micrograms/l iAs for a week were also considered. Plasma mass spectrometry (ICP-MS) was used for the analysis of total As in air and urine samples, whereas the urinary As species (trivalent, As3; pentavalent, As5; monomethyl arsonic acid, MMA; dimethyl arsinic acid, DMA; arsenobetaine, AsB) were measured by liquid chromatography coupled with plasma mass spectrometry (HPLC-MS) RESULTS: Environmental concentrations of As in air varied widely (mean 84 micrograms/m3, SD 61, median 40) and also the sum of urinary iAs MMA and DMA, varied among the groups of exposed subjects (mean 106 micrograms/l, SD 84, median 65). AsB was the most excreted species (34% of total As) followed by DMA (28%), MMA (26%), and As3 + As5 (12%). In the volunteers who drank As in the water the excretion of MMA and DMA increased (from a median of 0.5 to 5 micrograms/day for MMA and from 4 to 13 micrograms/day for DMA). The best correlations between As in air and its urinary species were found for total iAs and As3 + As5. CONCLUSIONS: To avoid the effect of As from sources other than occupation on urinary species of the element, in particular on DMA, it is proposed that urinary As3 + As5 may an indicator for monitoring the exposure to iAs. For concentrations of 10 micrograms/m3 the current environmental limit for iAs, the limit for urinary As3 + As5 was calculated to be around 5 micrograms/l, even if the wide

  10. Biology Today. Thinking Chemically about Biology.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1990-01-01

    Discussed are applications of biochemistry. Included are designed drugs, clever drugs, carcinogenic structures, sugary wine, caged chemicals, biomaterials, marine chemistry, biopolymers, prospecting bacteria, and plant chemistry. (CW)

  11. Inorganic sulfur-nitrogen compounds: from gunpowder chemistry to the forefront of biological signaling.

    PubMed

    Cortese-Krott, Miriam M; Butler, Anthony R; Woollins, J Derek; Feelisch, Martin

    2016-04-14

    The reactions between inorganic sulfur and nitrogen-bearing compounds to form S-N containing species have a long history and, besides assuming importance in industrial synthetic processes, are of relevance to microbial metabolism; waste water treatment; aquatic, soil and atmospheric chemistry; and combustion processes. The recent discovery that hydrogen sulfide and nitric oxide exert often similar, sometimes mutually dependent effects in a variety of biological systems, and that the chemical interaction of these two species leads to formation of S-N compounds brought this chemistry to the attention of physiologists, biochemists and physicians. We here provide a perspective about the potential role of S-N compounds in biological signaling and briefly review their chemical properties and bioactivities in the context of the chronology of their discovery. Studies of the biological role of NO revealed why its chemistry is ideally suited for the tasks Nature has chosen for it; realising how the distinctive properties of sulfur can enrich this bioactivity does much to revive 'die Freude am experimentellen Spiel' of the pioneers in this field.

  12. Chemiluminescent chemical sensors for inorganic and organic vapors

    SciTech Connect

    Collins, G.E.; Rose-Pehrsson, S.L.

    1995-12-31

    Chemiluminescent, chemical sensors for inorganic and organic vapors are being investigated via the immobilization of 3-aminophthalhydrazide (luminol) within hydrogels and polymeric, sorbent coatings. The films are supported behind a teflon membrane and positioned in front of a photomultiplier tube, permitting the sensitive detection of numerous toxic vapors. Some selectivity has been tailored into these devices by careful selection of the polymer type, pH and metal catalyst incorporated within the film. The incorporation of luminol and Fe(3) within a polyvinylalcohol hydrogel gave a film with superior sensitivity toward NO{sub 2} (detection limit of 0.46 ppb and a response time on the order of seconds). The use of the hydrogel matrix helped eliminate humidity problems associated with other polymeric films. Other chemiluminescent thin films prepared have demonstrated the detection of ppb levels of SO{sub 2}(g) and hydrazine, N{sub 2}H{sub 4}(g). Recently, the authors have begun investigating the incorporation of a heated Pt filament into the inlet line as a pre-oxidative step prior to passage of the gas stream across the teflon membrane. This has permitted the sensitive detection of ppm levels of CCl{sub 4}(g), CHCl{sub 3}(g) and CH{sub 2}Cl{sub 2}(g).

  13. Inorganic chemicals in an effluent-dominated stream as indicators for chemical reactions and streamflows

    NASA Astrophysics Data System (ADS)

    Kim, Kangjoo; Lee, Ji Sun; Oh, Chang-Whan; Hwang, Gab-Soo; Kim, Jinsam; Yeo, Sungku; Kim, Yeongkyoo; Park, Seongmin

    2002-07-01

    The chemical behavior of major inorganic ions in the streams of the Mankyung River area (South Korea) was investigated. Mixing with effluent from the Jeonju STP (a municipal sewage treatment plant in Jeonju City) was the most important process in regulating the water chemistry of the streams. The effluent was chemically distinct relative to the stream waters in inorganic composition. Behavior of various ions was evaluated by comparing their concentrations with the concentration of chloride, a conservative chemical species. It was revealed that concentrations of chloride and sulfate, the total concentration of major cations, and electrical conductivity in the stream were controlled only by mixing, indicating their conservative behavior similar to chloride. Alkalinity and concentration of nitrate, however, were regulated by various reactions such as mixing, photosynthesis, respiration, and decomposition of organic matter. Streamflows were estimated by observing chemical composition of the effluent and those of up/downstream waters. Estimated flows based on the conservative chemical parameters were nearly the same as those directly measured using an area-velocity method, indicating the validity of the chemistry-based method.

  14. Applications of inorganic nanoparticles in biological electron microscopy

    NASA Astrophysics Data System (ADS)

    Ni, Thomas Wentung

    Electron microscopy is an immensely powerful for imaging at the cellular level. However, many of the macromolecules of interest are difficult to image due to low electron density. There has been an immense body of work in order to visualize these macromolecules. In the past, many of the methods of visualization revolved around staining samples with heavy metals, however these stains are non-specific. In order to develop more specific methods of tagging macromolecules, there are two different methods to consider: the first being a top-down approach, in which electron dense tags, in this case inorganic nanoparticles, are given specific ligands to take advantage of different chemistries to attach these nanoparticles to macromolecules of interest. The second method is through a bottom-up approach where biomolecules are given the specific ability to form inorganic nanoparticles. Inorganic nanoparticles have been investigated with various ligands in order to enhance binding capability to macromolecules. The chief method of functionalizing these inorganic nanoparticles comes from ligand exchange; much has been studied regarding ligand exchange, but there are still many unanswered questions. Herein, we endeavor to reveal both the mechanism of exchange and the functional unit of exchange. We also report progress towards understanding an enzyme that is capable of forming inorganic nanoparticles, which could be cloned onto proteins as well. This bottom up style has been studied in several other groups; however, none of the previously reported methods have seen much use. Herein, we report a potential NADPH-dependent enzyme that forms selenium nanoparticles.

  15. Electrostatic thin film chemical and biological sensor

    DOEpatents

    Prelas, Mark A.; Ghosh, Tushar K.; Tompson, Jr., Robert V.; Viswanath, Dabir; Loyalka, Sudarshan K.

    2010-01-19

    A chemical and biological agent sensor includes an electrostatic thin film supported by a substrate. The film includes an electrostatic charged surface to attract predetermined biological and chemical agents of interest. A charge collector associated with said electrostatic thin film collects charge associated with surface defects in the electrostatic film induced by the predetermined biological and chemical agents of interest. A preferred sensing system includes a charge based deep level transient spectroscopy system to read out charges from the film and match responses to data sets regarding the agents of interest. A method for sensing biological and chemical agents includes providing a thin sensing film having a predetermined electrostatic charge. The film is exposed to an environment suspected of containing the biological and chemical agents. Quantum surface effects on the film are measured. Biological and/or chemical agents can be detected, identified and quantified based on the measured quantum surface effects.

  16. Chemical, Biological, Radiological, and Nuclear Consequence Management

    EPA Pesticide Factsheets

    The Chemical, Biological, Radiological, and Nuclear CMAD provides scientific support and technical expertise for decontamination of buildings, building contents, public infrastructure, agriculture, and associated environmental media.

  17. Colloidal inorganic nanocrystals: Nucleation, growth and biological applications

    NASA Astrophysics Data System (ADS)

    Lynch, Jared James

    Colloidal inorganic nanocrystals are a class of material whose size ranges from a few nanometers to a hundred nanometers in dimension. These nanocrystals have size dependent properties that differ significantly from the bulk material counterparts. Due to their unique physical properties colloidal inorganic nanocrystals have several promising applications in a diverse range of areas, such as biomedical diagnosis, catalysis, plasmonics, high-density data storage and solar energy conversion. This dissertation presents the study of the formation of iron oxide nanocrystals under the influence of solvent and Ar gas bubbles, the phase transfer of metal oxide nanocrystals into water using inorganic ions, and the doping of semiconductor CdS/ZnS core/shell nanocrystals with copper and silver ions. First, the formation of iron oxide nanocrystals is investigated in the presence of boiling solvent or Ar bubbles. Using a non-injection based synthesis method, the thermal decomposition of iron oleate was studied under various reaction conditions, and the role of the bubbles on the nucleation and growth of iron oxide nanocrystals was determined. Kinetics studies were used to elucidate how latent heat transfer from the bubbles allows for "active monomers" to form preferentially from exothermic reactions taking place during nucleation. General insights into colloidal inorganic nanocrystal formation are discussed. Second, a non-injection based synthesis for CdS/ZnS core/shell nanocrystals is used to make high quality semiconductor particles which are intentionally doped with Cu or Ag ions. The Ag ions effect on the optical properties of the CdS/ZnS nanocrystals is investigated. The absorption and fluorescence of the samples is measured as a function of time and temperature. Proposed mechanisms for the observations are given and thoroughly discussed. Comparisons between previous results for Cu doped CdS/ZnS nanocrystals are also made to further understand how doping of semiconductor

  18. Nanoelectromechanics of Inorganic and Biological Systems: From Structural Imaging to Local Functionalities

    SciTech Connect

    Rodriguez, Brian; Kalinin, Sergei V; Jesse, Stephen; Thompson, G. L.; Vertegel, Alexey; Hohlbauch, Sophia; Proksch, Roger

    2008-01-01

    Coupling between electrical and mechanical phenomena is extremely common in inorganic materials, and nearly ubiquitous in biological systems, underpinning phenomena and devices ranging from SONAR to cardiac activity and hearing. This paper briefly summarizes the Scanning Probe Microscopy (SPM) approach, referred to as Piezoresponse Force Microscopy (PFM), for probing electromechanical coupling on the nanometer scales, and delineates some existing and emerging applications to probe local structure and functionality in inorganic ferroelectrics, calcified and connective tissues, and complex biosystems based on electromechanical detection.

  19. INORGANIC CHEMICAL CHARACTERIZATION OF WATER TREATMENT PLANT RESIDUALS

    EPA Science Inventory

    The study obtained field data on the inorganic contaminants and constituents in residuals produced by Water Treatment Plants (WTPs). Eight WTPs were studied based on treatment technology, contamination or suspected contamination of raw water, and efficiency in the removal of cont...

  20. 40 CFR 142.62 - Variances and exemptions from the maximum contaminant levels for organic and inorganic chemicals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Dibromochloropropane X X (27) 2,4-D X (28) Ethylene dibromide X X (29) Heptachlor X (30) Heptachlor epoxide X (31... for the inorganic chemicals listed in § 141.62: BAT for Inorganic Compounds Listed in §...

  1. Biologic and chemical weapons of mass destruction.

    PubMed

    Bozeman, William P; Dilbero, Deanna; Schauben, Jay L

    2002-11-01

    Weapons of mass destruction (WMDs) are capable of producing massive casualties and are typically grouped into nuclear, biologic, and chemical weapons. In the wake of the September 11th disasters, attention to terrorist groups and the potential for use of WMDs has increased. Biologic and chemical weapons are relatively accessible and inexpensive to develop, and are thought to be the most available to foreign states and subnational terrorist groups. This article reviews various biologic and chemical weapons, including emergency diagnosis and management of selected agents.

  2. Leaching Kinetics of Atrazine and Inorganic Chemicals in Tilled and Orchard Soils

    NASA Astrophysics Data System (ADS)

    Szajdak, Lech W.; Lipiec, Jerzy; Siczek, Anna; Nosalewicz, Artur; Majewska, Urszula

    2014-04-01

    The aim of this study was to verify first-order kinetic reaction rate model performance in predicting of leaching of atrazine and inorganic compounds (K+1, Fe+3, Mg+2, Mn+2, NH4 +, NO3 - and PO4 -3) from tilled and orchard silty loam soils. This model provided an excellent fit to the experimental concentration changes of the compounds vs. time data during leaching. Calculated values of the first-order reaction rate constants for the changes of all chemicals were from 3.8 to 19.0 times higher in orchard than in tilled soil. Higher first-order reaction constants for orchard than tilled soil correspond with both higher total porosity and contribution of biological pores in the former. The first order reaction constants for the leaching of chemical compounds enables prediction of the actual compound concentration and the interactions between compound and soil as affected by management system. The study demonstrates the effectiveness of simultaneous chemical and physical analyses as a tool for the understanding of leaching in variously managed soils.

  3. Discovery of Chemical Toxicity via Biological Networks and Systems Biology

    SciTech Connect

    Perkins, Edward; Habib, Tanwir; Guan, Xin; Escalon, Barbara; Falciani, Francesco; Chipman, J.K.; Antczak, Philipp; Edwards, Stephen; Taylor, Ronald C.; Vulpe, Chris; Loguinov, Alexandre; Van Aggelen, Graham; Villeneuve, Daniel L.; Garcia-Reyero, Natalia

    2010-09-30

    Both soldiers and animals are exposed to many chemicals as the result of military activities. Tools are needed to understand the hazards and risks that chemicals and new materials pose to soldiers and the environment. We have investigated the potential of global gene regulatory networks in understanding the impact of chemicals on reproduction. We characterized effects of chemicals on ovaries of the model animal system, the Fathead minnow (Pimopheles promelas) connecting chemical impacts on gene expression to circulating blood levels of the hormones testosterone and estradiol in addition to the egg yolk protein vitellogenin. We describe the application of reverse engineering complex interaction networks from high dimensional gene expression data to characterize chemicals that disrupt the hypothalamus-pituitary-gonadal endocrine axis that governs reproduction in fathead minnows. The construction of global gene regulatory networks provides deep insights into how drugs and chemicals effect key organs and biological pathways.

  4. History of chemical and biological warfare agents.

    PubMed

    Szinicz, L

    2005-10-30

    Chemical and biological warfare agents constitute a low-probability, but high-impact risk both to the military and to the civilian population. The use of hazardous materials of chemical or biological origin as weapons and for homicide has been documented since ancient times. The first use of chemicals in terms of weapons of mass destruction goes back to World War I, when on April 22, 1915 large amounts of chlorine were released by German military forces at Ypres, Belgium. Until around the 1970s of the 20th century, the awareness of the threat by chemical and biological agents had been mainly confined to the military sector. In the following time, the development of increasing range delivery systems by chemical and biological agents possessors sensitised public attention to the threat emanating from these agents. Their proliferation to the terrorists field during the 1990s with the expanding scale and globalisation of terrorist attacks suggested that these agents are becoming an increasing threat to the whole world community. The following article gives a condensed overview on the history of use and development of the more prominent chemical and biological warfare agents.

  5. Photonic applications based on biological/inorganic nano hybrids

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Wu, Pengfei; Yelleswarapu, Chandra

    2016-02-01

    Biological Retinal is an effective and efficient photochromic compounds and one of the best candidates for photon conversion, transmission and storage, from the view of bionics and natural selection. We observed large optical nonlinearity by using new fabricated films of photoactive Retinol hybrid materials. Based on reversible photoinduced anisotropy and transient optical characteristics, the Retinol hybrids can be used to design novel photonic devices, such as holographic elements, all-optical switch and spatial light modulator. Also, the study is important for further understanding the photochemical mechanism of vision process.

  6. Organometallic compounds: an opportunity for chemical biology?

    PubMed

    Patra, Malay; Gasser, Gilles

    2012-06-18

    Organometallic compounds are renowned for their remarkable applications in the field of catalysis, but much less is known about their potential in chemical biology. Indeed, such compounds have long been considered to be either unstable under physiological conditions or cytotoxic. As a consequence, little attention has been paid to their possible utilisation for biological purposes. Because of their outstanding physicochemical properties, which include chemical stability, structural diversity and unique photo- and electrochemical properties, however, organometallic compounds have the ability to play a leading role in the field of chemical biology. Indeed, remarkable examples of the use of such compounds-notably as enzyme inhibitors and as luminescent agents-have recently been reported. Here we summarise recent advances in the use of organometallic compounds for chemical biology purposes, an area that we define as "organometallic chemical biology". We also demonstrate that these recent discoveries are only a beginning and that many other organometallic complexes are likely to be found useful in this field of research in the near future.

  7. Perspective: Reaches of chemical physics in biology.

    PubMed

    Gruebele, Martin; Thirumalai, D

    2013-09-28

    Chemical physics as a discipline contributes many experimental tools, algorithms, and fundamental theoretical models that can be applied to biological problems. This is especially true now as the molecular level and the systems level descriptions begin to connect, and multi-scale approaches are being developed to solve cutting edge problems in biology. In some cases, the concepts and tools got their start in non-biological fields, and migrated over, such as the idea of glassy landscapes, fluorescence spectroscopy, or master equation approaches. In other cases, the tools were specifically developed with biological physics applications in mind, such as modeling of single molecule trajectories or super-resolution laser techniques. In this introduction to the special topic section on chemical physics of biological systems, we consider a wide range of contributions, all the way from the molecular level, to molecular assemblies, chemical physics of the cell, and finally systems-level approaches, based on the contributions to this special issue. Chemical physicists can look forward to an exciting future where computational tools, analytical models, and new instrumentation will push the boundaries of biological inquiry.

  8. The chemical biology of methanogenesis

    NASA Astrophysics Data System (ADS)

    Ferry, James G.

    2010-12-01

    Two distinct pathways account for most of the CH 4 produced in the majority of the diverse and vast anaerobic environments of Earth's biosphere by microbes that are classified in the Archaea domain of life: conversion of the methyl group of acetate to CH 4 in the aceticlastic pathway and reduction of CO 2 with electrons derived from H 2, formate or CO in the CO 2 reduction pathway. Minor, albeit ecologically important, amounts of CH 4 are produced by conversion of methylotrophic substrates methanol, methylamines and methyl sulfides. Although all pathways have terminal steps in common, they deviate in the initial steps leading to CH 4 and mechanisms for synthesizing ATP for growth. Hydrogen gas is the major reductant for CO 2-reducing methanogens in the deep subsurface, although H 2 is also utilized by CO 2-reducing microbes from the Bacteria domain that produce acetate for the aceticlastic methanogens. This review presents fundamentals of the two major CH 4-producing pathways with a focus on understanding the potential for biologically-produced CH 4 on Mars.

  9. Chemical Foundations of Hydrogen Sulfide Biology

    PubMed Central

    Li, Qian; Lancaster, Jack R.

    2013-01-01

    Following nitric oxide (nitrogen monoxide) and carbon monoxide, hydrogen sulfide (or its newer systematic name sulfane, H2S) became the third small molecule that can be both toxic and beneficial depending on the concentration. In spite of its impressive therapeutic potential, the underlying mechanisms for its beneficial effects remain unclear. Any novel mechanism has to obey fundamental chemical principles. H2S chemistry was studied long before its biological relevance was discovered, however, with a few exceptions, these past works have received relatively little attention in the path of exploring the mechanistic conundrum of H2S biological functions. This review calls attention to the basic physical and chemical properties of H2S, focuses on the chemistry between H2S and its three potential biological targets: oxidants, metals and thiol derivatives, discusses the applications of these basics into H2S biology and methodology, and introduces the standard terminology to this youthful field. PMID:23850631

  10. Electrochemical approaches for chemical and biological analysis on Mars.

    PubMed

    Kounaves, Samuel P

    2003-02-17

    Obtaining in situ chemical data from planetary bodies such as Mars or Europa can present significant challenges. The one analytical technique that has many of the requisite characteristics to meet such a challenge is electroanalysis. Described here are three electroanalytical devices designed for in situ geochemical and biological analysis on Mars. The Mars Environmental Compatibility Assessment (MECA) was built and flight qualified for the now cancelled NASA Mars 2001 Lander. Part of MECA consisted of four "cells" containing arrays of electrochemical based sensors for measuring the ionic species in soil samples. A next-generation MECA, the Robotic Chemical Analysis Laboratory (RCAL), uses a carousel-type system to allow for greater customization of analytical procedures. A second instrument, proposed as part of the 2007 CryoScout mission, consists of a flow-through inorganic chemical analyzer (MICA). CryoScout is a torpedo-like device designed for subsurface investigation of the stratigraphic climate record embedded in Mars' north polar cap. As the CryoScout melts its way through the ice cap, MICA will collect and analyze the meltwater for a variety of inorganics and chemical parameters. By analyzing the chemistry locked in the layers of dust, salt, and ice, geologists will be able to determine the recent history of climate, water, and atmosphere on Mars and link it to the past. Finally, electroanalysis shows its abilities in the detection of possible microorganism on Mars or elsewhere in the solar system. To identify an unknown microorganism, one that may not even use Earth-type biochemistry, requires a detection scheme which makes minimal assumptions and looks for the most general features. Recent work has demonstrated that the use of an array of electrochemical sensors which monitors the changes in a solution via electrical conductivity, pH, and ion selective electrodes, can be used to detect minute chemical perturbations caused by the growth of bacteria and

  11. Electrochemical approaches for chemical and biological analysis on Mars

    NASA Technical Reports Server (NTRS)

    Kounaves, Samuel P.

    2003-01-01

    Obtaining in situ chemical data from planetary bodies such as Mars or Europa can present significant challenges. The one analytical technique that has many of the requisite characteristics to meet such a challenge is electroanalysis. Described here are three electroanalytical devices designed for in situ geochemical and biological analysis on Mars. The Mars Environmental Compatibility Assessment (MECA) was built and flight qualified for the now cancelled NASA Mars 2001 Lander. Part of MECA consisted of four "cells" containing arrays of electrochemical based sensors for measuring the ionic species in soil samples. A next-generation MECA, the Robotic Chemical Analysis Laboratory (RCAL), uses a carousel-type system to allow for greater customization of analytical procedures. A second instrument, proposed as part of the 2007 CryoScout mission, consists of a flow-through inorganic chemical analyzer (MICA). CryoScout is a torpedo-like device designed for subsurface investigation of the stratigraphic climate record embedded in Mars' north polar cap. As the CryoScout melts its way through the ice cap, MICA will collect and analyze the meltwater for a variety of inorganics and chemical parameters. By analyzing the chemistry locked in the layers of dust, salt, and ice, geologists will be able to determine the recent history of climate, water, and atmosphere on Mars and link it to the past. Finally, electroanalysis shows its abilities in the detection of possible microorganism on Mars or elsewhere in the solar system. To identify an unknown microorganism, one that may not even use Earth-type biochemistry, requires a detection scheme which makes minimal assumptions and looks for the most general features. Recent work has demonstrated that the use of an array of electrochemical sensors which monitors the changes in a solution via electrical conductivity, pH, and ion selective electrodes, can be used to detect minute chemical perturbations caused by the growth of bacteria and

  12. A universal bias in inorganic rainwater chemical composition data

    NASA Astrophysics Data System (ADS)

    Ayers, Gregory P.; Gillett, Robert W.; Selleck, Paul W.

    2003-07-01

    In the late 1970s, it was recognised that organic acids contributed to the acidity and ionic content of rainwater, but that these acids had not been detected because they were consumed biologically in the period between rainwater collection and subsequent laboratory analysis. Discussion of consequences for measured rainwater composition has been limited to assessment of pH gain that attends organic acid loss. We show that biological effects on rainwater ionic composition are not restricted to pH alone. Ammonium, potassium, nitrate, sulfate, methanesulfonate, and phosphate ions are also removed biologically, but remain in the rainwater in biomass, implying that most previous rainwater composition studies based on ionic analyses will have systematically underestimated nutrient deposition.

  13. Chemical synthetic biology: a mini-review

    PubMed Central

    Chiarabelli, Cristiano; Stano, Pasquale; Luisi, Pier Luigi

    2013-01-01

    Chemical synthetic biology (CSB) is a branch of synthetic biology (SB) oriented toward the synthesis of chemical structures alternative to those present in nature. Whereas SB combines biology and engineering with the aim of synthesizing biological structures or life forms that do not exist in nature – often based on genome manipulation, CSB uses and assembles biological parts, synthetic or not, to create new and alternative structures. A short epistemological note will introduce the theoretical concepts related to these fields, whereas the text will be largely devoted to introduce and comment two main projects of CSB, carried out in our laboratory in the recent years. The “Never Born Biopolymers” project deals with the construction and the screening of RNA and peptide sequences that are not present in nature, whereas the “Minimal Cell” project focuses on the construction of semi-synthetic compartments (usually liposomes) containing the minimal and sufficient number of components to perform the basic function of a biological cell. These two topics are extremely important for both the general understanding of biology in terms of function, organization, and development, and for applied biotechnology. PMID:24065964

  14. 40 CFR 268.36 - Waste specific prohibitions-inorganic chemical wastes

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Waste specific prohibitions-inorganic chemical wastes 268.36 Section 268.36 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.36...

  15. 40 CFR 268.36 - Waste specific prohibitions-inorganic chemical wastes

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Waste specific prohibitions-inorganic chemical wastes 268.36 Section 268.36 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.36...

  16. 40 CFR 268.36 - Waste specific prohibitions-inorganic chemical wastes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Waste specific prohibitions-inorganic chemical wastes. 268.36 Section 268.36 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.36...

  17. 40 CFR 268.36 - Waste specific prohibitions-inorganic chemical wastes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 28 2013-07-01 2013-07-01 false Waste specific prohibitions-inorganic chemical wastes. 268.36 Section 268.36 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.36...

  18. 40 CFR 268.36 - Waste specific prohibitions-inorganic chemical wastes

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Waste specific prohibitions-inorganic chemical wastes 268.36 Section 268.36 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.36...

  19. Safety in the Chemical Laboratory: Is Thioacetamide a Serious Health Hazard in Inorganic Chemistry Laboratories?

    ERIC Educational Resources Information Center

    Elo, Hannu

    1987-01-01

    Describes the potential health hazards of using thioacetamide in introductory courses where students are involved in qualitative inorganic analysis. Describes the chemical as possessing carcinogenic, hepatotoxic, and mutagenic properties. Cautions that thioacetamide has caused various biochemical changes in the liver, and recommends limited uses…

  20. An Alternative Educational Approach for an Inorganic Chemistry Laboratory Course in Industrial and Chemical Engineering

    ERIC Educational Resources Information Center

    Garces, Andres; Sanchez-Barba, Luis Fernando

    2011-01-01

    We describe an alternative educational approach for an inorganic chemistry laboratory module named "Experimentation in Chemistry", which is included in Industrial Engineering and Chemical Engineering courses. The main aims of the new approach were to reduce the high levels of failure and dropout on the module and to make the content match the…

  1. Diazo Compounds: Versatile Tools for Chemical Biology.

    PubMed

    Mix, Kalie A; Aronoff, Matthew R; Raines, Ronald T

    2016-12-16

    Diazo groups have broad and tunable reactivity. That and other attributes endow diazo compounds with the potential to be valuable reagents for chemical biologists. The presence of diazo groups in natural products underscores their metabolic stability and anticipates their utility in a biological context. The chemoselectivity of diazo groups, even in the presence of azido groups, presents many opportunities. Already, diazo compounds have served as chemical probes and elicited novel modifications of proteins and nucleic acids. Here, we review advances that have facilitated the chemical synthesis of diazo compounds, and we highlight applications of diazo compounds in the detection and modification of biomolecules.

  2. Thermal and chemical degradation of inorganic membrane materials. Final report, August 1992--May 1995

    SciTech Connect

    Damle, A.S.; Krishnan, G.N.; Sanjurjo, A.; Wood, B.J.; Lau, K.H.

    1995-05-01

    SRI International conducted a theoretical and experimental program to evaluate the long-term thermal and chemical degradation of inorganic membranes that are being developed to separate the gaseous products of coal gasification. A variety of developmental efforts are underway, including a number of projects sponsored by the US Department of Energy (DOE), to improve the selectivity and permeability of porous inorganic membranes. DOE is also sponsoring efforts to extend the use of metallic membranes to new applications. Most developmental efforts have focused on hydrogen separation by inorganic membranes, which may be used to maximize hydrogen production from coal gas or to remove H{sub 2}S and NH{sub 3} contaminants via thermal or catalytic decomposition in integrated-gasification combined-cycle (IGCC) systems. Inorganic membranes that have a high separation efficiency and exhibit both thermal and chemical stability would improve the economics of power generation from coal. Membrane materials that have been investigated include glass (silica), alumina, carbon, and metals (Pd and Pt). This report describes inorganic membrane materials, long term membrane exposure tests, membrane permeation tests, coal gasifier exposure tests, conclusions, and recommendations.

  3. A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations

    PubMed Central

    Hata, Akihisa; Kurosawa, Hidetoshi; Endo, Yoko; Yamanaka, Kenzo; Fujitani, Noboru; Endo, Ginji

    2016-01-01

    Objectives: The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure. Methods: We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Results: iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m3 of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure. Conclusion: We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m3 iAs exposure, respectively. PMID:27010090

  4. Protection against radiation (biological, pharmacological, chemical, physical)

    NASA Technical Reports Server (NTRS)

    Saksonov, P. P.

    1975-01-01

    Physical, chemical, and biological protection for astronauts from penetrating radiation on long-term space flights is discussed. The status of pharmacochemical protection, development of protective substances, medical use of protective substances, protection for spacecraft ecologic systems, adaptogens and physical conditioning, bone marrow transplants and local protection are discussed. Combined use of local protection and pharmacochemical substances is also briefly considered.

  5. The Control of Chemical and Biological Weapons.

    ERIC Educational Resources Information Center

    Alexander, Archibald S.; And Others

    This book is composed of four papers prepared to illuminate the problem areas which might arise if the policies of the 1925 Geneva Protocol and other measures to limit chemical and biological weapons are ratified by the United States Senate. The papers included are: Legal Aspects of the Geneva Protocol of 1925; The Use of Herbicides in War: A…

  6. Cyclic metabolites: chemical and biological considerations.

    PubMed

    Erve, John C L

    2008-02-01

    Metabolism of xenobiotics can sometimes generate cyclic metabolites. Such metabolites are usually the result of intramolecular reactions occurring within a primary or secondary metabolite and this chemistry may lead to unexpected structures. Intramolecular chemistry is often driven by nucleophilic groups reacting with electrophilic atoms, often carbon, although radical processes also occur. Conjugation of xenobiotics or their metabolites with endogenous thiols, such as glutathione or cysteine, introduce a reactive amino group that can lead to the formation of cyclic structures. Less common than chemically driven cyclizations are enzymatically mediated ring-closures, although this may reflect our incomplete recognition of enzymatic involvement in this step of cyclic metabolite formation. While some cyclic metabolites are biologically inactive, others are biologically active. Thus, a cyclic metabolite may display desirable pharmacology, or, contribute to toxicology. When a cyclic metabolite is identified, it is important to consider the possibility that it is an artifact, i.e. metabonate, that was formed during processing of the sample, for example, through degradation or by chemical reactions with other components present in the matrix. From a medicinal chemistry perspective, a cyclic metabolite with a different chemical scaffold from the parent structure may lead to a new series of structurally novel, biologically active molecules with the same, or different, pharmacology from the parent. This review will cover a selection of cyclic metabolites from a mechanistic point of view, and when possible, discuss their biological relevance.

  7. News: Synthetic biology leading to specialty chemicals ...

    EPA Pesticide Factsheets

    Synthetic biology can combine the disciplines of biology, engineering, and chemistry productively to form molecules of great scientific and commercial value. Recent advances in the new field are explored for their connection to new tools that have been used to elucidate production pathways to a wide variety of chemicals generated by microorganisms. The selection and enhancement of microbiological strains through the practice of strain engineering enables targets of design, construction, and optimization. This news column aspires to cover recent literature relating to the development and understanding of clean technology.

  8. Polyketide stereocontrol: a study in chemical biology

    PubMed Central

    2017-01-01

    The biosynthesis of reduced polyketides in bacteria by modular polyketide synthases (PKSs) proceeds with exquisite stereocontrol. As the stereochemistry is intimately linked to the strong bioactivity of these molecules, the origins of stereochemical control are of significant interest in attempts to create derivatives of these compounds by genetic engineering. In this review, we discuss the current state of knowledge regarding this key aspect of the biosynthetic pathways. Given that much of this information has been obtained using chemical biology tools, work in this area serves as a showcase for the power of this approach to provide answers to fundamental biological questions. PMID:28326145

  9. Bright Building Blocks for Chemical Biology

    PubMed Central

    2014-01-01

    Small-molecule fluorophores manifest the ability of chemistry to solve problems in biology. As we noted in a previous review (Lavis, L. D.; Raines, R. T. ACS Chem. Biol.2008, 3, 142–155), the extant collection of fluorescent probes is built on a modest set of “core” scaffolds that evolved during a century of academic and industrial research. Here, we survey traditional and modern synthetic routes to small-molecule fluorophores and highlight recent biological insights attained with customized fluorescent probes. Our intent is to inspire the design and creation of new high-precision tools that empower chemical biologists. PMID:24579725

  10. The fundamental nature of life as a chemical system: the part played by inorganic elements.

    PubMed

    Williams, Robert J P

    2002-02-01

    In this article we show why inorganic metal elements from the environment were an essential part of the origin of living aqueous systems of chemicals in flow. Unavoidably such systems have many closely fixed parameters, related to thermodynamic binding constants, for the interaction of the essential exchangeable inorganic metal elements with both inorganic and organic non-metal materials. The binding constants give rise to fixed free metal ion concentration profiles for different metal ions and ligands in the cytoplasm of all cells closely related to the Irving-Williams series. The amounts of bound elements depend on the organic molecules present as well as these free ion concentrations. This system must have predated coding which is probably only essential for reproductive life. Later evolution in changing chemical environments became based on the development of extra cytoplasmic compartments containing quite different energised free (and bound) element contents but in feed-back communication with the central primitive cytoplasm which changed little. Hence species multiplied late in evolution in large part due to the coupling with the altered inorganic environment.

  11. Optofluidic Microsystems for Chemical and Biological Analysis

    PubMed Central

    Fan, Xudong; White, Ian M.

    2011-01-01

    Optofluidics – the synergistic integration of photonics and microfluidics – has recently emerged as a new analytical field that provides a number of unique characteristics for enhanced sensing performance and simplification of microsystems. In this review, we describe various optofluidic architectures developed in the past five years, emphasize the mechanisms by which optofluidics enhances bio/chemical analysis capabilities, including sensing and the precise control of biological micro/nanoparticles, and envision new research directions to which optofluidics leads. PMID:22059090

  12. [Decontamination of chemical and biological warfare agents].

    PubMed

    Seto, Yasuo

    2009-01-01

    Chemical and biological warfare agents (CBWA's) are diverse in nature; volatile acute low-molecular-weight toxic compounds, chemical warfare agents (CWA's, gaseous choking and blood agents, volatile nerve gases and blister agents, nonvolatile vomit agents and lacrymators), biological toxins (nonvolatile low-molecular-weight toxins, proteinous toxins) and microbes (bacteria, viruses, rickettsiae). In the consequence management against chemical and biological terrorism, speedy decontamination of victims, facilities and equipment is required for the minimization of the damage. In the present situation, washing victims and contaminated materials with large volumes of water is the basic way, and additionally hypochlorite salt solution is used for decomposition of CWA's. However, it still remains unsolved how to dispose large volumes of waste water, and the decontamination reagents have serious limitation of high toxicity, despoiling nature against the environments, long finishing time and non-durability in effective decontamination. Namely, the existing decontamination system is not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up the usable decontamination system surpassing the present technologies. The symposiast presents the on-going joint project of research and development of the novel decontamination system against CBWA's, in the purpose of realizing nontoxic, fast, specific, effective and economical terrorism on-site decontamination. The projects consists of (1) establishment of the decontamination evaluation methods and verification of the existing technologies and adaptation of bacterial organophosphorus hydrolase, (2) development of adsorptive elimination technologies using molecular recognition tools, and (4) development of deactivation technologies using photocatalysis.

  13. Chemical and biological sensing using liquid crystals

    PubMed Central

    Carlton, Rebecca J.; Hunter, Jacob T.; Miller, Daniel S.; Abbasi, Reza; Mushenheim, Peter C.; Tan, Lie Na; Abbott, Nicholas L.

    2014-01-01

    The liquid crystalline state of matter arises from orientation-dependent, non-covalent interaction between molecules within condensed phases. Because the balance of intermolecular forces that underlies formation of liquid crystals is delicate, this state of matter can, in general, be easily perturbed by external stimuli (such as an electric field in a display). In this review, we present an overview of recent efforts that have focused on exploiting the responsiveness of liquid crystals as the basis of chemical and biological sensors. In this application of liquid crystals, the challenge is to design liquid crystalline systems that undergo changes in organization when perturbed by targeted chemical and biological species of interest. The approaches described below revolve around the design of interfaces that selectively bind targeted species, thus leading to surface-driven changes in the organization of the liquid crystals. Because liquid crystals possess anisotropic optical and dielectric properties, a range of different methods can be used to read out the changes in organization of liquid crystals that are caused by targeted chemical and biological species. This review focuses on principles for liquid crystal-based sensors that provide an optical output. PMID:24795857

  14. Water in Biological and Chemical Processes

    NASA Astrophysics Data System (ADS)

    Bagchi, Biman

    2013-11-01

    Part I. Bulk Water: 1. Uniqueness of water; 2. Anomalies of water; 3. Dynamics of water: molecular motions and hydrogen bond breaking kinetics; 4. Inherent structures of liquid water; 5. pH of water; Part II. Water in Biology: Dynamical View and Function: 6. Biological water; 7. Explicit role of water in biological functions; 8. Hydration of proteins; 9. Can we understand protein hydration layer: lessons from computer simulations; 10. Water in and around DNA and RNA; 11. Role of water in protein-DNA interaction; 12. Water surrounding lipid bilayers; 13. Water in Darwin's world; Part III. Water in Complex Chemical Systems: 14. Hydrophilic effects; 15. Hydrophobic effects; 16. Aqueous binary mixtures: amphiphilic effect; 17. Water in and around micelles, reverse micelles and microemulsions; 18. Water in carbon nanotubes; Part IV. Bulk Water: Advanced Topics: 19. Entropy of water; 20. Freezing of water into ice; 21. Supercritical water; 22. Microscopic approaches to understand water anomalies.

  15. Ion-binding of glycine zwitterion with inorganic ions in biologically relevant aqueous electrolyte solutions.

    PubMed

    Fedotova, Marina V; Kruchinin, Sergey E

    2014-06-01

    The ion-binding between inorganic ions and charged functional groups of glycine zwitter-ion in NaCl(aq), KCl(aq), MgCl2(aq), and CaCl2(aq) has been investigated over a wide salt concentration range by using integral equation theory in the 3D-RISM approach. These systems mimic biological systems where binding of ions to charged residues at protein surfaces is relevant. It has been found that the stability of ion pairs formed by the carboxylate group and added inorganic cations decreases in the sequence Mg(2+)>Ca(2+)>Na(+)>K(+). However, all formed ion pairs are weak and decrease in stability with increasing salt concentration. On the other hand, at a given salt concentration the stability of (-NH3(+):Cl(-))aq ion pairs is similar in all studied systems. The features of ion-binding and the salt concentration effect on this process are discussed.

  16. Chemical biology at the crossroads of molecular structure and mechanism.

    PubMed

    Doudna, Jennifer A

    2005-11-01

    Chemical insight into biological function is the holy grail of structural biology. Small molecules are central players as building blocks, effectors and probes of macromolecular structure and function.

  17. METHOD FOR PRODUCING WETTABLE SURFACES ON CONTACT LENSES BY CHEMICAL FORMATION OF INORGANIC FILMS

    DTIC Science & Technology

    Wettable surfaces of a permanent nature can be produced on contact lenses by means of the technic of chemical deposition of an inorganic film on the...immersion resistance. Stepwise instructions are given for the preparation of hydrophilic surfaces on contact lenses . The equipment developed for this work is relatively simple and inexpensive. (Author)...lens surface. The process is simpler, both in apparatus and procedure, than the vacuum deposition technic designed earlier for producing wettable

  18. The Chemical Biology of S-Nitrosothiols

    PubMed Central

    Broniowska, Katarzyna A.

    2012-01-01

    Abstract Significance: S-nitrosothiol formation and protein S-nitrosation is an important nitric oxide (NO)-dependent signaling paradigm that is relevant to almost all aspects of cell biology, from proliferation, to homeostasis, to programmed cell death. However, the mechanisms by which S-nitrosothiols are formed are still largely unknown, and there are gaps of understanding between the known chemical biology of S-nitrosothiols and their reported functions. Recent Advances: This review attempts to describe the biological chemistry of S-nitrosation and to point out where the challenges lie in matching the known chemical biology of these compounds with their reported functions. The review will detail new discoveries concerning the mechanisms of the formation of S-nitrosothiols in biological systems. Critical Issues: Although S-nitrosothiols may be formed with some degree of specificity on particular protein thiols, through un-catalyzed chemistry, and mechanisms for their degradation and redistribution are present, these processes are not sufficient to explain the vast array of specific and targeted responses of NO that have been attributed to S-nitrosation. Elements of catalysis have been discovered in the formation, distribution, and metabolism of S-nitrosothiols, but it is less clear whether these represent a specific network for targeted NO-dependent signaling. Future Directions: Much recent work has uncovered new targets for S-nitrosation through either targeted or proteome-wide approaches There is a need to understand which of these modifications represent concerted and targeted signaling processes and which is an inevitable consequence of living with NO. There is still much to be learned about how NO transduces signals in cells and the role played by protein S-nitrosation. Antioxid. Redox Signal. 17, 969–980. PMID:22468855

  19. Chemical and biological evaluation of Ranunculus muricatus.

    PubMed

    Khan, Farhat Ali; Zahoor, Muhammad; Khan, Ezzat

    2016-03-01

    Ranunculus muricatus is commonly known as spiny fruit buttercup and is used in the treatment of intermittent fevers, gout and asthma. Qualitative analysis of phytochemicals of Ranunculus muricatus indicated the presence of saponins, tannins, phenols, flavonoids and alkaloids. Saponins were present in high amount as compared with other chemicals. Inorganic and heavy metals constituents were determined. Heavy metals estimation in the sample showed that iron was present in high amount followed by zinc even then the concentration of these metals is below acceptable limit. The physical parameters, antioxidant and antimicrobial activities of the extracts were determined. Acetone extract fraction showed optimal antioxidant activity as compared to ethanol and chloroform fractions of the candidate plant. The antimicrobial and antifungal activities of the crude extract and extract fractions were determined by well agar diffusion method. Highest zone of inhibitions were observed for crude extract followed by acetone extract fraction against Micrococcus luteus. Antifungal activities were high for crude extracts against Candida Albican. Findings of this study show that Ranunculus muricatus has a good medicinal impact.

  20. Evaluating three methods that contribute to the learning of inorganic chemical nomenclature

    NASA Astrophysics Data System (ADS)

    Chimeno, Joseph Samuel

    The majority of students about to complete a first year chemistry course have a poor working knowledge of inorganic chemical nomenclature (average quiz scores are less than 60% correct). Usually, the chemical nomenclature topic is not emphasized in a first year chemistry class, and a minimum amount of time is devoted to it. The traditional assignment for chemical nomenclature involves having students work practice problems at the end of the chapter. Students are not very receptive to this approach. The minimal exposure to chemical nomenclature in class along with the ineffective approach of a traditional assignment results in students having a poor working knowledge of chemical nomenclature. Studies have claimed that students are more receptive to learning when game playing is combined with the learning activity. Therefore two educational games were created to help students develop a working knowledge of inorganic chemical nomenclature: the Rainbow Wheel and Rainbow Matrix. This study compared the learning of inorganic chemical nomenclature by three different methods; one was the traditional method where students worked problems at the end of a chapter, and the other two methods used a game format to learn chemical nomenclature. The statistical analysis of student performance was evaluated with analysis of variance (ANOVA) and t-tests. The analysis revealed that the game format methods were more effective in helping students develop a working knowledge of chemical nomenclature. The ANOVA test indicate that both the Rainbow Wheel and Rainbow Matrix post-assignment mean scores differ significantly from the traditional group's post-assignment mean scores (p < 0.05 Middle Tennessee State University (MTSU) data and p < 0.01 North Iowa Area Community College (NIACC) data). The t-tests revealed that there were significant differences between the traditional group's post-assignment mean scores and the game format groups' mean scores. The results of this study indicate that

  1. Chemical Biology for Understanding Matrix Metalloproteinase Function

    PubMed Central

    Knapinska, Anna; Fields, Gregg B.

    2013-01-01

    The matrix metalloproteinase (MMP) family has long been associated with normal physiological processes such as embryonic implantation, tissue remodeling, organ development, and wound healing, as well as multiple aspects of cancer initiation and progression, osteoarthritis, inflammatory and vascular diseases, and neurodegenerative diseases. The development of chemically designed MMP probes has advanced our understanding of the roles of MMPs in disease in addition to shedding considerable light on the mechanisms of MMP action. The first generation of protease-activated agents has demonstrated proof of principle as well as providing impetus for in vivo applications. One common problem has been a lack of agent stability at nontargeted tissues and organs due to activation by multiple proteases. The present review considers how chemical biology has impacted the progress made in understanding the roles of MMPs in disease and the basic mechanisms of MMP action. PMID:22933318

  2. Virus-Based Chemical and Biological Sensing

    PubMed Central

    Mao, Chuanbin; Liu, Aihua; Cao, Binrui

    2009-01-01

    Viruses have recently proven useful for the detection of target analytes such as explosives, proteins, bacteria, viruses, spores, and toxins with high selectivity and sensitivity. Bacteriophages (often shortened to phages), viruses that specifically infect bacteria, are currently the most studied viruses, mainly because target-specific nonlytic phages (and the peptides and proteins carried by them) can be identified by using the well-established phage display technique, and lytic phages can specifically break bacteria to release cell-specific marker molecules such as enzymes that can be assayed. In addition, phages have good chemical and thermal stability, and can be conjugated with nanomaterials and immobilized on a transducer surface in an analytical device. This Review focuses on progress made in the use of phages in chemical and biological sensors in combination with traditional analytical techniques. Recent progress in the use of virus—nanomaterial composites and other viruses in sensing applications is also high-lighted. PMID:19662666

  3. Direct-push geochemical profiling for assessment of inorganic chemical heterogeneity in aquifers

    USGS Publications Warehouse

    Schulmeister, M.K.; Healey, J.M.; Butler, J.J.; McCall, G.W.

    2004-01-01

    Discrete-depth sampling of inorganic groundwater chemistry is essential for a variety of site characterization activities. Although the mobility and rapid sampling capabilities of direct-push techniques have led to their widespread use for evaluating the distribution of organic contaminants, complementary methods for the characterization of spatial variations in geochemical conditions have not been developed. In this study, a direct-push-based approach for high-resolution inorganic chemical profiling was developed at a site where sharp chemical contrasts and iron-reducing conditions had previously been observed. Existing multilevel samplers (MLSs) that span a fining-upward alluvial sequence were used for comparison with the direct-push profiling. Chemical profiles obtained with a conventional direct-push exposed-screen sampler differed from those obtained with an adjacent MLS because of sampler reactivity and mixing with water from previous sampling levels. The sampler was modified by replacing steel sampling components with stainless-steel and heat-treated parts, and adding an adapter that prevents mixing. Profiles obtained with the modified approach were in excellent agreement with those obtained from an adjacent MLS for all constituents and parameters monitored (Cl, NO3, Fe, Mn, DO, ORP, specific conductance and pH). Interpretations of site redox conditions based on field-measured parameters were supported by laboratory analysis of dissolved Fe. The discrete-depth capability of this approach allows inorganic chemical variations to be described at a level of detail that has rarely been possible. When combined with the mobility afforded by direct-push rigs and on-site methods of chemical analysis, the new approach is well suited for a variety of interactive site-characterization endeavors. ?? 2003 Elsevier B.V. All rights reserved.

  4. 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.

  5. 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.

  6. Chemical and biological production of cyclotides

    PubMed Central

    Li, Yilong; Bi, Tao; Camarero, Julio A.

    2016-01-01

    Cyclotides are fascinating naturally occurring micro-proteins (≈30 residues long) present in several plant families, and display various biological properties such as protease inhibitory, anti-microbial, insecticidal, cytotoxic, anti-HIV and hormone-like activities. Cyclotides share a unique head-to-tail circular knotted topology of three disulfide bridges, with one disulfide penetrating through a macrocycle formed by the two other disulfides and interconnecting peptide backbones, forming what is called a cystine knot topology. This cyclic cystine knot (CCK) framework gives the cyclotides exceptional rigidity, resistance to thermal and chemical denaturation, and enzymatic stability against degradation. Interestingly, cyclotides have been shown to be orally bioavailable, and other cyclotides have been shown to cross the cell membranes. Moreover, recent reports have also shown that engineered cyclotides can be efficiently used to target extracellular and intracellular protein-protein interactions, therefore making cyclotides ideal tools for drug development to selectively target protein-protein interactions. In this work we will review all the available methods for production of these interesting proteins using chemical or biological methods. PMID:27064329

  7. Chemical Biology Strategies for Biofilm Control.

    PubMed

    Yang, Liang; Givskov, Michael

    2015-08-01

    Microbes live as densely populated multicellular surface-attached biofilm communities embedded in self-generated, extracellular polymeric substances (EPSs). EPSs serve as a scaffold for cross-linking biofilm cells and support development of biofilm architecture and functions. Biofilms can have a clear negative impact on humans, where biofilms are a common denominator in many chronic diseases in which they prime development of destructive inflammatory conditions and the failure of our immune system to efficiently cope with them. Our current assortment of antimicrobial agents cannot efficiently eradicate biofilms. For industrial applications, the removal of biofilms within production machinery in the paper and hygienic food packaging industry, cooling water circuits, and drinking water manufacturing systems can be critical for the safety and efficacy of those processes. Biofilm formation is a dynamic process that involves microbial cell migration, cell-to-cell signaling and interactions, EPS synthesis, and cell-EPS interactions. Recent progress of fundamental biofilm research has shed light on novel chemical biology strategies for biofilm control. In this article, chemical biology strategies targeting the bacterial intercellular and intracellular signaling pathways will be discussed.

  8. Chemical Transformations of Nanosilver in Biological Environments

    PubMed Central

    Liu, Jingyu; Wang, Zhongying; Liu, Frances D.; Kane, Agnes B.; Hurt, Robert H.

    2012-01-01

    The widespread use of silver nanoparticles (Ag-NPs) in consumer and medical products provides strong motivation for a careful assessment of their environmental and human health risks. Recent studies have shown that Ag-NPs released to the natural environment undergo profound chemical transformations that can affect silver bioavailability, toxicity, and risk. Less is known about Ag-NP chemical transformations in biological systems, though the medical literature clearly reports that chronic silver ingestion produces argyrial deposits consisting of silver-, sulfur-, and selenium-containing particulate phases. Here we show that Ag-NPs undergo a rich set of biochemical transformations, including accelerated oxidative dissolution in gastric acid, thiol binding and exchange, photoreduction of thiol- or protein-bound silver to secondary zero-valent Ag-NPs, and rapid reactions between silver surfaces and reduced selenium species. Selenide is also observed to rapidly exchange with sulfide in preformed Ag2S solid phases. The combined results allow us to propose a conceptual model for Ag-NP transformation pathways in the human body. In this model, argyrial silver deposits are not translocated engineered Ag-NPs, but rather secondary particles formed by partial dissolution in the GI tract followed by ion uptake, systemic circulation as organo-Ag complexes and immobilization as zero-valent Ag-NPs by photoreduction in light affected skin regions. The secondary Ag-NPs then undergo detoxifying transformations into sulfides, and further into selenides or Se/S mixed phases through exchange reactions. The formation of secondary particles in biological environments implies that Ag-NPs are not only a product of industrial nanotechnology, but have long been present in the human body following exposure to more traditional chemical forms of silver. PMID:23046098

  9. Chemical transformations of nanosilver in biological environments.

    PubMed

    Liu, Jingyu; Wang, Zhongying; Liu, Frances D; Kane, Agnes B; Hurt, Robert H

    2012-11-27

    The widespread use of silver nanoparticles (Ag-NPs) in consumer and medical products provides strong motivation for a careful assessment of their environmental and human health risks. Recent studies have shown that Ag-NPs released to the natural environment undergo profound chemical transformations that can affect silver bioavailability, toxicity, and risk. Less is known about Ag-NP chemical transformations in biological systems, though the medical literature clearly reports that chronic silver ingestion produces argyrial deposits consisting of silver-, sulfur-, and selenium-containing particulate phases. Here we show that Ag-NPs undergo a rich set of biochemical transformations, including accelerated oxidative dissolution in gastric acid, thiol binding and exchange, photoreduction of thiol- or protein-bound silver to secondary zerovalent Ag-NPs, and rapid reactions between silver surfaces and reduced selenium species. Selenide is also observed to rapidly exchange with sulfide in preformed Ag(2)S solid phases. The combined results allow us to propose a conceptual model for Ag-NP transformation pathways in the human body. In this model, argyrial silver deposits are not translocated engineered Ag-NPs, but rather secondary particles formed by partial dissolution in the GI tract followed by ion uptake, systemic circulation as organo-Ag complexes, and immobilization as zerovalent Ag-NPs by photoreduction in light-affected skin regions. The secondary Ag-NPs then undergo detoxifying transformations into sulfides and further into selenides or Se/S mixed phases through exchange reactions. The formation of secondary particles in biological environments implies that Ag-NPs are not only a product of industrial nanotechnology but also have long been present in the human body following exposure to more traditional chemical forms of silver.

  10. Measured Infrared Absorption and Extinction Cross Sections for a Variety of Chemically and Biologically Derived Aerosol Simulants

    DTIC Science & Technology

    2004-06-01

    Aerosols considered are categorized as biological, chemical, and inorganic in origin, i.e., bacillus subtilis endospores, dimethicone silicone oil...achieved. The materials considered for this study include dimethicone silicone oil (SF-96 grade 50), bacillus subtilis endospores (BG), and Kaolin

  11. Nanotechnologies and chemical tools for cell biology

    NASA Astrophysics Data System (ADS)

    Chen, Xing

    This dissertation describes several nanotechnologies and chemical tools that I have developed to probe living cells. Chapter one gives a brief overview on the current status of biomedical and biotechnological applications of carbon nanotubes (CNTs). In this chapter, strategies for functionalization of CNTs with emphasis on biological applications are reviewed. Representative developments in biosensing, bioimaging, intracellular delivery, and tissue engineering are presented. Recent studies on toxicity of CNTs are also discussed. Chapter two describes the development of a nanoscale cell injector for delivery of cargo to the interior of living cells without physiological harm. A CNT attached to an atomic force microscope tip was functionalized with cargo via a disulfide linker. Penetration of cell membranes with this "nanoneedle", followed by reductive cleavage of the disulfide bonds within the cell's interior, resulted in the release of cargo inside the cells. Chapter three presents a biomimetic functionalization strategy for interfacing CNTs with biological systems. The potential biological applications of CNTs have been limited by their insolubility in aqueous environment and their intrinsic toxicity. We developed a biomimetic surface modification of CNTs using glycosylated polymers designed to mimic natural cell surface mucin glycoproteins interactions. Chapter four further extends the biomimetic strategy for functionalization of CNTs to glycosylated dendrimers. We developed a new class of amphiphilic bifunctional glycodendrimers that comprised carbohydrate units displayed in the periphery and a pyrene tail that bound to SWNT surface via pi-pi interactions. The glycodendrimer-coated CNTs were soluble in water, and noncytotoxic. We also demonstrated that the coated CNTs could interface with biological systems including proteins and cells. Chapter five presents a biosensing application of glycodenderimer-coated CNTs. SWNTN-FETs coated with glycodendrimers were

  12. Chemically Integrated Inorganic-Graphene Two-Dimensional Hybrid Materials for Flexible Energy Storage Devices.

    PubMed

    Peng, Lele; Zhu, Yue; Li, Hongsen; Yu, Guihua

    2016-12-01

    State-of-the-art energy storage devices are capable of delivering reasonably high energy density (lithium ion batteries) or high power density (supercapacitors). There is an increasing need for these power sources with not only superior electrochemical performance, but also exceptional flexibility. Graphene has come on to the scene and advancements are being made in integration of various electrochemically active compounds onto graphene or its derivatives so as to utilize their flexibility. Many innovative synthesis techniques have led to novel graphene-based hybrid two-dimensional nanostructures. Here, the chemically integrated inorganic-graphene hybrid two-dimensional materials and their applications for energy storage devices are examined. First, the synthesis and characterization of different kinds of inorganic-graphene hybrid nanostructures are summarized, and then the most relevant applications of inorganic-graphene hybrid materials in flexible energy storage devices are reviewed. The general design rules of using graphene-based hybrid 2D materials for energy storage devices and their current limitations and future potential to advance energy storage technologies are also discussed.

  13. Chemical characterization of organic carbon dissolved in natural waters using inorganic adsorbents.

    PubMed

    Sugiyama, Y; Kumagai, T

    2001-01-01

    Dissolved organic carbon (DOC) in water samples from Lake Biwa was chemically characterized by two inorganic adsorbents with completely different surface characteristics. The two adsorbents were HIO (hydrous iron oxide) and SG (silica gel). Solutions of reference standard materials were analyzed concerning their adsorption behavior to HIO and SG for bovine serum albumin (BSA), fulvic acid extracted from the bottom sediments of Lake Biwa, phthalic acid, and starch. The adsorption of DOC to HIO was mainly controlled by ligand exchange and electrostatic interaction; that of SG was by electrostatic interaction. It was found that in a weak acid solution of around pH 5, BSA adsorbs to both HIO and SG, but that fulvic acid, phthalic acid and starch only show adsorption to HIO. Using these characteristics, DOC samples in natural water samples were characterized into pro-DOC, which adsorbs to both HIO and SG at pH 5, and car-DOC, which only adsorbs to HIO at pH 5. The DOC samples in Lake Biwa on October 7, 1997, at sampling sites Nb-2 and Nb-5 (south basin of Lake Biwa, the depths were about 2 and 4 m), and Ie-1 (north basin of Lake Biwa, the depth was about 75 m) were characterized. The pro-DOC has different values, depending on their sampling sites and depths, and had the maximum value of 0.42 mg C l(-1) at the surface water of Ie-1, and had the lowest values at middle to deeper water depths (0.18-0.27 mg C l(-1)). The car-DOC showed a relatively stable value at Ie-1 regardless of the depth (0.63-0.83 mg C l(-1)), and the maximum value was observed in Nb-2 and Nb-5 (1.2 and 1.3 mg C l(-1)). The ratios between car-DOC and pro-DOC concentrations were 0.2-0.5, and had different values for different sampling sites and depths. The ratios were significantly different for surface water samples where the biological activities are high and for bottom water samples where decomposition predominates.

  14. The biological and chemical variability of yacon.

    PubMed

    Valentová, Katerina; Lebeda, Ales; Dolezalová, Ivana; Jirovský, David; Simonovska, Breda; Vovk, Irena; Kosina, Pavel; Gasmanová, Nikol; Dziechciarková, Marta; Ulrichová, Jitka

    2006-02-22

    This paper focuses on the biological and chemical variability of four yacon (Smallanthus sonchifolius) accessions cultivated under field conditions. Significant variations in tuber shape, weight, content of oligofructans, as well as in leaf isozymes, phenolics, and relative DNA contents were found. Accessions 6 and 88 were the most productive (up to 3.01 and 3.74 kg/plant); accession 48 was the most balanced from the yield aspect in three vegetative periods. A significantly higher content of beta-(2-->1) oligofructans was noted in accessions 48 and 88 as compared to 6 and 60. No difference in sucrose, glucose, and fructose level was observed. Only accession 6 exhibited separate acid phosphatase and esterase isoforms. Accessions 6 and 60 had the highest content of phenolics, and accession 88 had the lowest relative DNA content. Large yacon intraspecific variation may be useful in future detailed research as a good background for breeding, growing, and utilization in industrial processing.

  15. Chemical oxidation of biologically treated phenolic effluents

    SciTech Connect

    Kamenev, S.; Kallas, J.; Munter, R.; Trapido, M.

    1995-12-01

    Experimental research into the oxidative purification of biologically treated phenolic effluents of the Estonian oil shale chemical industry was undertaken. The main phenolic compounds identified in this wastewater were phenol, cresols, resorcinol and 5-methylresorcinols. For chemical oxidation of phenols different advanced oxidation methods (O{sub 3}, H{sub 2}O{sub 2}, UV, O{sub 3}/H{sub 2}O{sub 2}, O{sub 3}/UV, H{sub 2}O{sub 2}/UV, O{sub 3}/H{sub 2}O{sub 2}/UV) were tested. For tracking of the changes in the concentration of different phenols during the treatment process, HPLC and colorimetry were applied. It was shown that, in principle, phenols can be reduced almost by any oxidation method studied. Oxidation with molecular ozone has the most potential for practical application. Methods not including ozone (H{sub 2}O{sub 2}, UV, H{sub 2}O{sub 2}/UV) had, in general, lower efficiency for total phenols reduction than the methods combining ozone.

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

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

  17. Colorimetric estimation of inorganic phosphate in colored and/or turbid biological samples: assay of phosphohydrolases.

    PubMed

    Upreti, G C

    1984-03-01

    A simple method of inorganic phosphate determination for colored and/or turbid biological samples is described. The procedure is mild, and so is suitable for routine phosphohydrolase assays. Following deproteinization by ice-cold trichloroacetic (or silicotungstic) acid, the sample was treated with acid-washed charcoal to remove interference due to color. The phosphate in the colorless supernatant was assayed either by measuring the phosphomolybdate spectrophotometrically at 310 nm, following its extraction in organic solvents or by a modified Fiske and Subbarow method. The turbidity interference in the latter case was eliminated either by centrifugation, by sodium dodecyl sulfate treatment, or by extraction of reduced phosphomolybdate blue color by cyclohexanone. Though deproteinization by silicotungstic acid eliminated the turbidity problem, its use in conjunction with charcoal treatment was not convenient.

  18. Inorganic chemical composition and chemical reactivity of settled dust generated by the World Trade Center building collapse

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Hageman, Philip L.; Lamothe, Paul J.; Ziegler, Thomas L.; Meeker, Gregory P.; Theodorakos, Peter M.; Brownfield, Isabelle; Adams, Monique G.; Swayze, Gregg A.; Hoefen, Todd M.; Taggart, Joseph E.; Clark, Roger N.; Wilson, S.; Sutley, Stephen J.

    2009-01-01

    Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions with rain water or water used in street washing and fire fighting. Chemical leach tests using deionized water as the extraction fluid show the dust samples can be quite alkaline, due primarily to reactions with calcium hydroxide in concrete particles. Calcium and sulfate are the most soluble components in the dust, but many other elements are also readily leached, including metals such as Al, Sb, Mo Cr, Cu, and Zn. Indoor dust samples produce leachates with higher pH, alkalinity, and dissolved solids than outdoor dust samples, suggesting most outdoor dust had reacted with water and atmospheric carbon dioxide prior to sample collection. Leach tests using simulated lung fluids as the extracting fluid suggest that the dust might also be quite reactive in fluids lining the respiratory tract, resulting in dissolution of some particles and possible precipitation of new phases such as phosphates, carbonates, and silicates. Results of these chemical characterization studies can be used by health scientists as they continue to track and interpret health effects resulting from the short-term exposure to the initial dust cloud and the longer-term exposure to dusts resuspended during cleanup.

  19. Biologically Inspired Synthesis Route to Three-Dimensionally Structured Inorganic Thin Films

    DOE PAGES

    Schwenzer, Birgit; Morse, Daniel E.

    2008-01-01

    Inorganic thin films (hydroxide, oxide, and phosphate materials) that are textured on a submicron scale have been prepared from aqueous metal salt solutions at room temperature using vapor-diffusion catalysis. This generic synthesis approach mimics the essential advantages of the catalytic and structure-directing mechanisms observed for the formation of silica skeletons of marine sponges. Chemical composition, crystallinity, and the three-dimensional morphology of films prepared by this method are extremely sensitive to changes in the synthesis conditions, such as concentrations, reaction times, and the presence and nature of substrate materials. Focusing on different materials systems, the reaction mechanism for the formation ofmore » these thin films and the influence of different reaction parameters on the product are explained.« less

  20. Modeling the Detection of Organic and Inorganic Compounds Using Iodide-Based Chemical Ionization.

    PubMed

    Iyer, Siddharth; Lopez-Hilfiker, Felipe; Lee, Ben H; Thornton, Joel A; Kurtén, Theo

    2016-02-04

    Iodide-based chemical ionization mass spectrometry (CIMS) has been used to detect and measure concentrations of several atmospherically relevant organic and inorganic compounds. The significant electronegativity of iodide and the strong acidity of hydroiodic acid makes electron transfer and proton abstraction essentially negligible, and the soft nature of the adduct formation ionization technique reduces the chances of sample fragmentation. In addition, iodide has a large negative mass defect, which, when combined with the high resolving power of a high resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS), provides good selectivity. In this work, we use quantum chemical methods to calculate the binding energies, enthalpies and free energies for clusters of an iodide ion with a number of atmospherically relevant organic and inorganic compounds. Systematic configurational sampling of the free molecules and clusters was carried out at the B3LYP/6-31G* level, followed by subsequent calculations at the PBE/SDD and DLPNO-CCSD(T)/def2-QZVPP//PBE/aug-cc-pVTZ-PP levels. The binding energies, enthalpies, and free energies thus obtained were then compared to the iodide-based University of Washington HR-ToF-CIMS (UW-CIMS) instrument sensitivities for these molecules. We observed a reasonably linear relationship between the cluster binding enthalpies and logarithmic instrument sensitivities already at the PBE/SDD level, which indicates that relatively simple quantum chemical methods can predict the sensitivity of an iodide-based CIMS instrument toward most molecules. However, higher level calculations were needed to treat some outlier molecules, most notably oxalic acid and methylerythritol. Our calculations also corroborated the recent experimental findings that the molecules that the UW-CIMS detects at maximum sensitivity usually have binding enthalpies to iodide which are higher than about 26 kcal/mol, depending slightly on the level of theory.

  1. Chemical speciation of inorganic pollutants in river-estuary-sea water systems.

    PubMed

    Tepavitcharova, Stefka; Todorov, Tihomir; Rabadjieva, Diana; Dassenakis, Manos; Paraskevopoulou, Vasiliki

    2009-02-01

    Monitoring studies and thermodynamic modeling were used to reveal the changes of inorganic chemical species of some water pollutants (nutrients and trace metals such as Fe, Mn, Zn, Cu, Cd and Pb) inthe river-estuary-sea water system. The case studies were two rivers, Kamchiya and Ropotamo, representing part of the Bulgarian Black Sea water catchment area, and having different flow characteristics. There were no major differences in inorganic chemical species of the two river systems. NO3(-) and NO2(-) chemical species showed no changes along the river-estuary-sea water system. Concerning phosphates six different species were calculated and differences between the three parts of the systems were established. The HPO4(2-) and H2PO4(-) species were found to be dominant in river waters. The H2PO4(-) species quickly decreased at the expense of HPO4(2-) and Ca, Mg and Na phosphate complexes in estuary and seawater. Trace metals showed a great variety of chemical species. Fe(OH)2(+) species prevailed in river waters, and Fe(OH)3(0) species--in sea waters. Me2+ and MeCO3(0) (Me = Cu, Pb) and PbHCO3(+) were dominant in river waters, while Cu(CO3)2(2-) and PbCl(-) species appear also in sea waters. Cd2+ species prevailed in river and estuary waters, and CdCln(2-n) (n = 1-3) species, in seawater. Free Zn2+ species predominated in all systems but downstream their percentage decreased at the expense of Zn phosphates, carbonates,sulfates and chlorides complexes. Only free Mn2+ species were dominant along the systems.

  2. Use of carbonates for biological and chemical synthesis

    DOEpatents

    Rau, Gregory Hudson

    2014-09-09

    A system of using carbonates, especially water-insoluble or sparing soluble mineral carbonates, for maintaining or increasing dissolved inorganic carbon concentrations in aqueous media. In particular, the system generates concentrated dissolve inorganic carbon substrates for photosynthetic, chemosynthetic, or abiotic chemical production of carbonaceous or other compounds in solution. In some embodiments, the invention can also enhance the dissolution and retention of carbon dioxide in aqueous media, and can produce pH buffering capacity, metal ions, and heat, which can be beneficial to the preceding syntheses.

  3. Integrated chemical and biological systems in nanowire structures towards nano-scale sensors

    NASA Astrophysics Data System (ADS)

    Hernandez, Rose M.

    Nanowires composed of metal and conducting polymers with integrated proteins and chemical systems have been investigated as building blocks for next-generation nano-scale sensors and assemblies. These nanowires were fabricated by combining chemical and electrochemical methods of synthesis of gold and conducting polymers in nanopores of anodized alumina membranes. Polymer nanowires were synthesized from buffer solutions as a mean to promote a biocompatible environment for the incorporation of proteins. A variety of proteins were incorporated into the polymer matrix by entrapment during polymerization that imparted the polymer material with biological functionality. Another class of composite nanowires containing electro-active conducting polymer junctions was developed for applications in chemical sensor arrays. The methodologies described in this thesis provide an inexpensive and straightforward approach to the synthesis of anisotropic nanoparticles incorporating a variety of biological and inorganic species that can be integrated to current microelectronic technologies for the development of nano-scale sensor arrays.

  4. Nanoparticles made of π-conjugated compounds targeted for chemical and biological applications.

    PubMed

    Xu, Xinjun; Liu, Ronghua; Li, Lidong

    2015-12-07

    Semiconducting organic nanoparticles have recently attracted increasing attention in the chemical and biomedical fields. Such nanoparticles are mainly composed of π-conjugated compounds. They possess the properties of easy synthesis, facile tuning, less toxicity and more biocompatibility relative to the existing inorganic nanoparticles. In addition, they show advantages such as brighter fluorescence, higher photostability and higher biocompatibility, compared with classical fluorescent organic dyes. In this review, we summarize the latest advances in the development of organic nanoparticles made of π-conjugated compounds, including preparation methods, material design, nanoparticle fabrication and surface functionalization for chemical and biological applications. Especially, we focus on the applications of semiconducting organic nanoparticles in chemical and biological sensing by monitoring the fluorescence signal, as nanocarriers for drug/gene delivery, in photothermal and photodynamic therapy, and in photoacoustic imaging. Finally, the challenges and perspectives for the future development of organic nanoparticles based on π-conjugated compounds are also discussed.

  5. 78 FR 55326 - Determinations Regarding Use of Chemical Weapons in Syria Under the Chemical and Biological...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ... Determinations Regarding Use of Chemical Weapons in Syria Under the Chemical and Biological Weapons Control and... to Section 306(a) of the Chemical and Biological Weapons Control and Warfare Elimination Act of 1991, 22 U.S.C. 5604(a), that the Government of Syria has used chemical weapons in violation...

  6. 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.

  7. Challenges and opportunities in synthetic biology for chemical engineers

    PubMed Central

    Luo, Yunzi; Lee, Jung-Kul; Zhao, Huimin

    2012-01-01

    Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement. PMID:24222925

  8. Challenges and opportunities in synthetic biology for chemical engineers

    SciTech Connect

    Luo, YZ; Lee, JK; Zhao, HM

    2013-11-15

    Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement. (C) 2012 Elsevier Ltd. All rights reserved.

  9. BIOLOGICAL AND CHEMICAL STUDIES ON MYCOBACTERIA

    PubMed Central

    Fregnan, G. B.; Smith, D. W.; Randall, H. M.

    1961-01-01

    Fregnan, G. B. (University of Wisconsin, Madison), D. W. Smith, and H. M. Randall. Biological and chemical studies on mycobacteria. Relationship of colony morphology to mycoside content for Mycobacterium kansasii and Mycobacterium fortuitum. J. Bacteriol. 82:517–527. 1961.—Using a suitable technique and an adequate medium it was possible to show a unique and uniform type of colony characteristic for Mycobacterium kansasii (photochromogen) and for Mycobacterium fortuitum strains freshly isolated either from patients, or from the soil, or kept in our stock culture collection for several years. New symbols have been proposed to represent these colony types. It was demonstrated that colony morphology is closely related to the specific mycoside present in a given strain; for example, M. kansasii strains showed in each instance colony type K and mycoside A, and M. fortuitum strains showed colony type F and mycoside F. Attention is called to the importance of the technique and the medium used. No change in colony morphology resulted from incubation in the presence of air containing 5 to 10% CO2, although this improved growth. Better growth of mycobacteria occurred in the presence of glycerol, or lipids of a human strain of mycobacteria, or sodium bicarbonate, but the specificity of colony form was lost. Images PMID:13894938

  10. Chemical Tumor Biology of Heparan Sulfate Proteoglycans

    PubMed Central

    Raman, Karthik; Kuberan, Balagurunathan

    2010-01-01

    Heparan sulfate proteoglycans (HSPGs) play vital roles in every step of tumor progression allowing cancer cells to proliferate, escape from immune response, invade neighboring tissues, and metastasize to distal sites away from the primary site. Several cancers including breast, lung, brain, pancreatic, skin, and colorectal cancers show aberrant modulation of several key HS biosynthetic enzymes such as 3-O Sulfotransferase and 6-O Sulfotransferase, and also catabolic enzymes such as HSulf-1, HSulf-2 and heparanase. The resulting tumor specific HS fine structures assist cancer cells to breakdown ECM to spread, misregulate signaling pathways to facilitate their proliferation, promote angiogenesis to receive nutrients, and protect themselves against natural killer cells. This review focuses on the changes in the expression of HS biosynthetic and catabolic enzymes in several cancers, the resulting changes in HS fine structures, and the effects of these tumor specific HS signatures on promoting invasion, proliferation, and metastasis. It is possible to retard tumor progression by modulating the deregulated biosynthetic and catabolic pathways of HS chains through novel chemical biology approaches. PMID:20596243

  11. Effect of electric pulse processing on physical and chemical properties of inorganic materials

    NASA Astrophysics Data System (ADS)

    Sakipova, S. E.; Nussupbekov, B. R.; Ospanova, D.; Khassenov, A.; Sakipova, Sh E.

    2015-04-01

    This article analyzes various aspects of the practical application of electric pulse technology of industrial raw materials processing as a result of a spark electric discharge in a liquid solution of the raw material under processing. The object of the study are samples of technogenic materials from a deposit in Central Kazakhstan, which are crushed and ground to particles with a preset degree of fragmentation. The electric pulse processing is performed by using different numbers of discharges. The effect of electric pulse processing with different electrical parameters is carried out on the basis of comparison of the properties and structure of metal-containing and industrial raw materials after machining and electric pulse processing. The X-ray spectral microanalysis was performed using a scanning microscope. The researchers obtained data on changes in the microstructure and elemental composition of inorganic material samples as a result of electric pulse processing. It was established that the technology of electric pulse crushing and grinding of inorganic materials makes it possible to obtain not only a final product with desired size of dispersed particles, but also to change their physical and chemical properties.

  12. PSL Chemical Biology Symposia First 2016 Edition: When Chemistry and Biology Share the Language of Discovery.

    PubMed

    Gautier, Arnaud; Rodriguez, Raphaël

    2017-03-30

    Chemical biology, the science of understanding biological processes at the molecular level, has grown exponentially with the development of chemical strategies to manipulate and quantify biology with unprecedented precision. Recent advances presented at the Université Paris Sciences et Lettres symposium are discussed.

  13. Inorganic nitrogen transformations in the bed of the Shingobee River, Minnesota: Integrating hydrologic and biological processes using sediment perfusion cores

    USGS Publications Warehouse

    Sheibley, R.W.; Duff, J.H.; Jackman, A.P.; Triska, F.J.

    2003-01-01

    Inorganic N transformations were examined in streambed sediments from the Shingobee River using sediment perfusion cores. The experimental design simulated groundwater-stream water mixing within sediment cores, which provided a well-defined one-dimensional representation of in situ hydrologic conditions. Two distinct hydrologic and chemical settings were preserved in the sediment cores: the lowermost sediments, perfused with groundwater, remained anaerobic during the incubations, whereas the uppermost sediments, perfused with oxic water pumped from the overlying water column, simulated stream water penetration into the bed. The maintenance of oxic and anoxic zones formed a biologically active aerobic-anaerobic interface. Ammonium (NH4+) dissolved in groundwater was transported conservatively through the lower core zone but was removed as it mixed with aerated recycle water. Concurrently, a small quantity of nitrate (NO3-) equaling ???25% of the NH4+ loss was produced in the upper sediments. The NH4+ and NO3- profiles in the uppermost sediments resulted from coupled nitrification-denitrification, because assimilation and sorption were negligible. We hypothesize that anaerobic microsites within the aerated upper sediments supported denitrification. Rates of nitrification and denitrification in the perfusion cores ranged 42-209 and 53-160 mg N m-2 day-1, respectively. The use of modified perfusion cores permitted the identification and quantification of N transformations and verified process control by surface water exchange into the shallow hyporheic zone of the Shingobee River.

  14. A Simple Method for the Calculation of Lattice Energies of Inorganic Ionic Crystals Based on the Chemical Hardness.

    PubMed

    Kaya, Savaş; Kaya, Cemal

    2015-09-08

    This paper presents a new technique for estimation of lattice energies of inorganic ionic compounds using a simple formula. This new method demonstrates the relationship between chemical hardness and lattice energies of ionic compounds. Here chemical hardness values of ionic compounds are calculated via our molecular hardness equation. The results obtained using the present method and comparisons made by considering experimental data and the results from other theoretical methods in the literature showed that the new method allows easy evaluation of lattice energies of inorganic ionic crystals without the need for ab initio calculations and complex calculations.

  15. Chemical and Biological Terrorism: Current Updates for Nurse Educators.

    ERIC Educational Resources Information Center

    Veenema, Tener Goodwin

    2002-01-01

    Describes eight topics related to chemical/biological terrorism for a standalone nursing course or integration into other courses: surveillance systems; identification, communication, and response; chemical agents; biological agents; recognition of covert exposure; patient decontamination and mass triage; availability and safety of therapies; and…

  16. Inorganic chemical investigation by X-ray fluorescence analysis - The Viking Mars Lander

    NASA Technical Reports Server (NTRS)

    Toulmin, P., III; Rose, H. J., Jr.; Baird, A. K.; Clark, B. C.; Keil, K.

    1973-01-01

    The inorganic chemical investigation experiment added in August 1972 to the Viking Lander scientific package uses an energy-dispersive X-ray fluorescence spectrometer in which four sealed, gas-filled proportional counters detect X-rays emitted from samples of the Martian surface materials irradiated by X-rays from radioisotope sources (Fe-55 and Cd-109). The instrument is inside the Lander body, and samples are to be delivered to it by the Viking Lander Surface Sampler. Instrument design is described along with details of the data processing and analysis procedures. The results of the investigation will characterize the surface materials of Mars as to elemental composition with accuracies ranging from a few tens of parts per million (at the trace-element level) to a few per cent (for major elements) depending on the element in question.

  17. Structural resistance of chemically modified 1-D nanostructured titanates in inorganic acid environment

    SciTech Connect

    Marinkovic, Bojan A.; Fredholm, Yann C.; Morgado, Edisson

    2010-10-15

    Sodium containing one-dimensional nanostructured layered titanates (1-D NSLT) were produced both from commercial anatase powder and Brazilian natural rutile mineral sands by alkali hydrothermal process. The 1-D NSLT were chemically modified with proton, cobalt or iron via ionic exchange and all products were additionally submitted to intensive inorganic acid aging (pH = 0.5) for 28 days. The morphology and crystal structure transformations of chemically modified 1-D NSLT were followed by transmission electron microscopy, powder X-ray diffraction, selected area electron diffraction and energy dispersive spectroscopy. It was found that the original sodium rich 1-D NSLT and cobalt substituted 1-D NSLT were completely converted to rutile nanoparticles, while the protonated form was transformed in a 70%-30% (by weight) anatase-rutile nanoparticles mixture, very similar to that of the well-known TiO{sub 2}-photocatalyst P25 (Degussa). The iron substituted 1-D NSLT presented better acid resistance as 13% of the original structure and morphology remained, the rest being converted in rutile. A significant amount of remaining 1-D NSLT was also observed after the acid treatment of the product obtained from rutile sand. The results showed that phase transformation of NSLT into titanium dioxide polymorph in inorganic acid conditions were controllable by varying the exchanged cations. Finally, the possibility to transform, through acid aging, 1-D NSLT obtained from Brazilian natural rutile sand into TiO{sub 2}-polymorphs was demonstrated for the first time to the best of authors' knowledge, opening path for producing TiO{sub 2}-nanoproducts with different morphologies through a simple process and from a low cost precursor.

  18. Inorganic chemical investigation by x-ray fluorescence analysis: The Viking Mars Lander

    USGS Publications Warehouse

    Toulmin, P.; Baird, A.K.; Clark, B. C.; Keil, Klaus; Rose, H.J.

    1973-01-01

    The inorganic chemical investigation added in August 1972 to the Viking Lander scientific package will utilize an energy-dispersive X-ray fluorescence spectrometer in which four sealed, gas-filled proportional counters will detect X-rays emitted from samples of the Martian surface materials irradiated by X-rays from radioisotope sources (55Fe and 109Cd). The output of the proportional counters will be subjected to pulse-height analysis by an on-board step-scanning single-channel analyzer with adjustable counting periods. The data will be returned to Earth, via the Viking Orbiter relay system, and the spectra constructed, calibrated, and interpreted here. The instrument is inside the Lander body, and samples are to be delivered to it by the Viking Lander Surface Sampler. Calibration standards are an integral part of the instrument. The results of the investigation will characterize the surface materials of Mars as to elemental composition with accuracies ranging from a few tens of parts per million (at the trace-element level) to a few percent (for major elements) depending on the element in question. Elements of atomic number 11 or less are determined only as a group, though useful estimates of their individual abundances maybe achieved by indirect means. The expected radiation environment will not seriously hamper the measurements. Based on the results, inferences can be drawn regarding (1) the surface mineralogy and lithology; (2) the nature of weathering processes, past and present, and the question of equilibrium between the atmosphere and the surface; and (3) the extent and type of differentiation that the planet has undergone. The Inorganic Chemical Investigation supports and is supported by most other Viking Science investigations. ?? 1973.

  19. Optimizing the Domestic Chemical, Biological, Radiological, and Nuclear Response Enterprise

    DTIC Science & Technology

    2015-03-01

    OPTIMIZING THE DOMESTIC CHEMICAL , BIOLOGICAL, RADIOLOGICAL, AND NUCLEAR RESPONSE ENTERPRISE THESIS MARCH 2015 Nick Paul, Captain, USA AFIT-ENS-MS-15...of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENS-MS-15-M-143 OPTIMIZING THE DOMESTIC CHEMICAL ...DISTRIBUTION UNLIMITED. AFIT-ENS-MS-15-M-143 OPTIMIZING THE DOMESTIC CHEMICAL , BIOLOGICAL, RADIOLOGICAL, AND NUCLEAR RESPONSE ENTERPRISE THESIS Nick Paul

  20. The method of radioactive tracer for measuring the amount of inorganic nanoparticles in biological samples

    NASA Astrophysics Data System (ADS)

    Buzulukov, Yu; Antsiferova, A.; Demin, V. A.; Demin, V. F.; Kashkarov, P.

    2015-11-01

    The method to measure the mass of inorganic nanoparticles in biological (or any other samples) using nanoparticles labeled with radioactive tracers is developed and applied to practice. The tracers are produced in original nanoparticles by radioactive activation of some of their atomic nuclei. The method of radioactive tracers demonstrates a sensitivity, specificity and accuracy equal or better than popular methods of optical and mass spectrometry, or electron microscopy and has some specific advantages. The method can be used for study of absorption, distribution, metabolism and excretion in living organism, as well as in ecological and fundamental research. It was used in practice to study absorption, distribution, metabolism and excretion of nanoparticles of Ag, Au, Se, ZnO, TiO2 as well as to study transportation of silver nanoparticles through the barriers of blood-brain, placenta and milk gland of rats. Brief descriptions of data obtained in experiments with application of this method included in the article. The method was certified in Russian Federation standard system GOST-R and recommended by the Russian Federation regulation authority ROSPOTREBNADZOR for measuring of toxicokinetic and organotropy parameters of nanoparticles.

  1. News: Synthetic biology leading to specialty chemicals

    EPA Science Inventory

    Synthetic biology can combine the disciplines of biology, engineering, and chemistry productively to form molecules of great scientific and commercial value. Recent advances in the new field are explored for their connection to new tools that have been used to elucidate productio...

  2. Modes of interaction between inorganic engineered nanoparticles and biological and abiotic surfaces

    NASA Astrophysics Data System (ADS)

    Schaumann, G. E.; Abraham, P. M.; Dabrunz, A.

    2012-04-01

    Engineered nanoparticles aging and transformation pathways in natural environmental systems are linked with their attachment to surfaces of organisms, plant leaves, biofilms, soil or sediment particles. In this study we investigated attachment of nAg0 and nTiO2 to plant leaves and organic and inorganic model surfaces and daphnia with the objective to understand the physicochemistry behind these interactions as well as potential ecological effects linked with this attachment. Surface-nanoparticle interactions were investigated in well-defined sorption studies and compared to conditions in in ecotoxicological test systems. Model surfaces were chosen to cover a wide range of intermolecular interactions considering van-der Waals interactions as well as proton donor and acceptor interactions. The nanoparticle-surface complexes were analysed with microscopic techniques including optical microscopy, environmental scanning electron microscopy and atomic force microscopy (AFM) as well as with respect to physicochemical interactions. While deposition of nanoparticles in ecotoxicological test systems is often determined by aggregation, and toxicity may be induced by physical effects, sorption of nanoparticle from stable suspensions is controlled by the chemical nature of the model surfaces as well as by the surfaces accessible for the nanoparticles. The current results show that attachment is determined by an intensive interplay between physicochemical nanoparticle-surface interactions, aggregation stability and physical characteristics. This interplay will mutually affect the ecological relevance, including further fate, transport and effects of the nanoparticles in the environment.

  3. Chromatin as an expansive canvas for chemical biology.

    PubMed

    Fierz, Beat; Muir, Tom W

    2012-04-17

    Chromatin is extensively chemically modified and thereby acts as a dynamic signaling platform controlling gene function. Chromatin regulation is integral to cell differentiation, lineage commitment and organism development, whereas chromatin dysregulation can lead to age-related and neurodegenerative disorders as well as cancer. Investigating chromatin biology presents a unique challenge, as the issue spans many disciplines, including cell and systems biology, biochemistry and molecular biophysics. In recent years, the application of chemical biology methods for investigating chromatin processes has gained considerable traction. Indeed, chemical biologists now have at their disposal powerful chemical tools that allow chromatin biology to be scrutinized at the level of the cell all the way down to the single chromatin fiber. Here we present recent examples of how this rapidly expanding palette of chemical tools is being used to paint a detailed picture of chromatin function in organism development and disease.

  4. Integrative chemical-biological read-across approach for chemical hazard classification.

    PubMed

    Low, Yen; Sedykh, Alexander; Fourches, Denis; Golbraikh, Alexander; Whelan, Maurice; Rusyn, Ivan; Tropsha, Alexander

    2013-08-19

    Traditional read-across approaches typically rely on the chemical similarity principle to predict chemical toxicity; however, the accuracy of such predictions is often inadequate due to the underlying complex mechanisms of toxicity. Here, we report on the development of a hazard classification and visualization method that draws upon both chemical structural similarity and comparisons of biological responses to chemicals measured in multiple short-term assays ("biological" similarity). The Chemical-Biological Read-Across (CBRA) approach infers each compound's toxicity from both chemical and biological analogues whose similarities are determined by the Tanimoto coefficient. Classification accuracy of CBRA was compared to that of classical RA and other methods using chemical descriptors alone or in combination with biological data. Different types of adverse effects (hepatotoxicity, hepatocarcinogenicity, mutagenicity, and acute lethality) were classified using several biological data types (gene expression profiling and cytotoxicity screening). CBRA-based hazard classification exhibited consistently high external classification accuracy and applicability to diverse chemicals. Transparency of the CBRA approach is aided by the use of radial plots that show the relative contribution of analogous chemical and biological neighbors. Identification of both chemical and biological features that give rise to the high accuracy of CBRA-based toxicity prediction facilitates mechanistic interpretation of the models.

  5. Syntheses and biological studies of marine terpenoids derived from inorganic cyanide.

    PubMed

    Schnermann, Martin J; Shenvi, Ryan A

    2015-04-01

    Isocyanoterpenes (ICTs) are marine natural products biosynthesized through an unusual pathway that adorns terpene scaffolds with nitrogenous functionality derived from cyanide. The appendage of nitrogen functional groups - isonitriles in particular - onto stereochemically-rich carbocyclic ring systems provides enigmatic, bioactive molecules that have required innovative chemical syntheses. This review discusses the challenges inherent to the synthesis of this diverse family and details the development of the field. We also present recent progress in isolation and discuss key aspects of the remarkable biological activity of these compounds.

  6. Syntheses and Biological Studies of Marine Terpenoids Derived from Inorganic Cyanide

    PubMed Central

    Schnermann, Martin J.; Shenvi, Ryan A.

    2015-01-01

    Isocyanoterpenes (ICTs) are marine natural products biosynthesized through an unusual pathway that adorns terpene scaffolds with nitrogenous functionality derived from cyanide. The appendage of nitrogen functional groups–isonitriles in particular–onto stereochemically-rich carbocyclic ring systems provides enigmatic, bioactive molecules that have required innovative chemical syntheses. This review discusses the challenges inherent to the synthesis of this diverse family and details the development of the field. We also present recent progress in isolation and discuss key aspects of the remarkable biological activity of these compounds. PMID:25514696

  7. Combined chemical-biological treatment of wastewater containing refractory pollutants.

    PubMed

    Jeworski, M; Heinzle, E

    2000-01-01

    Biological processes are usually most efficient for degrading pollutants occurring in wastewater. Refractory and toxic compounds contained limit their applicability. In such cases combinations with chemical oxidation processes may improve the overall efficiency and efficacy. Most suitable oxidation processes for combination with biological treatment are wet air oxidation, ozonation, hydrogen peroxide treatment and other advanced oxidation processes. Most effective are OH-radicals produced in all these oxidation processes. Chemical oxidation produces intermediates with usually improved biodegradability. Process combinations may be serial or with recycling between chemical oxidation and biological treatment. Design criteria, control of combined processes and recent applications are reviewed.

  8. Chemical and Biological Warfare: A Selected Bibliography

    DTIC Science & Technology

    1991-04-01

    Unpreparedneas: The American Expeditionary Forces and Chemical Warfare." MILITARY REVIEW , Vol. 65, January 1985, pp. 12-25. (Periodical) US Army Command and...WEAPONS. New York: Monthly Review Press, 1984. (UG447 M86 1984) US Congress. House. Committee on Foreign Affairs. Subcommittee on International...34 Cover Story. WORLD PRESS REVIEW , Vol. 36, March 1989, pp. 11-21. (Periodical) "A Chemical Warfare Glossary." ARMY, Vol. 37, August 1987, pp. 34-35

  9. Construction of a Linux based chemical and biological information system.

    PubMed

    Molnár, László; Vágó, István; Fehér, András

    2003-01-01

    A chemical and biological information system with a Web-based easy-to-use interface and corresponding databases has been developed. The constructed system incorporates all chemical, numerical and textual data related to the chemical compounds, including numerical biological screen results. Users can search the database by traditional textual/numerical and/or substructure or similarity queries through the web interface. To build our chemical database management system, we utilized existing IT components such as ORACLE or Tripos SYBYL for database management and Zope application server for the web interface. We chose Linux as the main platform, however, almost every component can be used under various operating systems.

  10. Integrative Chemical-Biological Read-Across Approach for Chemical Hazard Classification

    PubMed Central

    Low, Yen; Sedykh, Alexander; Fourches, Denis; Golbraikh, Alexander; Whelan, Maurice; Rusyn, Ivan; Tropsha, Alexander

    2013-01-01

    Traditional read-across approaches typically rely on the chemical similarity principle to predict chemical toxicity; however, the accuracy of such predictions is often inadequate due to the underlying complex mechanisms of toxicity. Here we report on the development of a hazard classification and visualization method that draws upon both chemical structural similarity and comparisons of biological responses to chemicals measured in multiple short-term assays (”biological” similarity). The Chemical-Biological Read-Across (CBRA) approach infers each compound's toxicity from those of both chemical and biological analogs whose similarities are determined by the Tanimoto coefficient. Classification accuracy of CBRA was compared to that of classical RA and other methods using chemical descriptors alone, or in combination with biological data. Different types of adverse effects (hepatotoxicity, hepatocarcinogenicity, mutagenicity, and acute lethality) were classified using several biological data types (gene expression profiling and cytotoxicity screening). CBRA-based hazard classification exhibited consistently high external classification accuracy and applicability to diverse chemicals. Transparency of the CBRA approach is aided by the use of radial plots that show the relative contribution of analogous chemical and biological neighbors. Identification of both chemical and biological features that give rise to the high accuracy of CBRA-based toxicity prediction facilitates mechanistic interpretation of the models. PMID:23848138

  11. Cutaneous reactions in nuclear, biological and chemical warfare.

    PubMed

    Arora, Sandeep

    2005-01-01

    Nuclear, biological and chemical warfare have in recent times been responsible for an increasing number of otherwise rare dermatoses. Many nations are now maintaining overt and clandestine stockpiles of such arsenal. With increasing terrorist threats, these agents of mass destruction pose a risk to the civilian population. Nuclear and chemical attacks manifest immediately while biological attacks manifest later. Chemical and biological attacks pose a significant risk to the attending medical personnel. The large scale of anticipated casualties in the event of such an occurrence would need the expertise of all physicians, including dermatologists, both military and civilian. Dermatologists are uniquely qualified in this respect. This article aims at presenting a review of the cutaneous manifestations in nuclear, chemical and biological warfare and their management.

  12. Biomaterials for mediation of chemical and biological warfare agents.

    PubMed

    Russell, Alan J; Berberich, Jason A; Drevon, Geraldine F; Koepsel, Richard R

    2003-01-01

    Recent events have emphasized the threat from chemical and biological warfare agents. Within the efforts to counter this threat, the biocatalytic destruction and sensing of chemical and biological weapons has become an important area of focus. The specificity and high catalytic rates of biological catalysts make them appropriate for decommissioning nerve agent stockpiles, counteracting nerve agent attacks, and remediation of organophosphate spills. A number of materials have been prepared containing enzymes for the destruction of and protection against organophosphate nerve agents and biological warfare agents. This review discusses the major chemical and biological warfare agents, decontamination methods, and biomaterials that have potential for the preparation of decontamination wipes, gas filters, column packings, protective wear, and self-decontaminating paints and coatings.

  13. Studies on Semantic Systems Chemical Biology

    ERIC Educational Resources Information Center

    Chen, Bin

    2012-01-01

    Current "one disease, one target and one drug" drug development paradigm is under question as relatively few drugs have reached the market in the last two decades. Increasingly research focus is being placed on the study of drug action against biological systems as a whole rather than against a single component (called "Systems…

  14. Chemical and biological sensing using tuning forks

    DOEpatents

    Tao, Nongjian; Boussaad, Salah

    2012-07-10

    A device for sensing a chemical analyte is disclosed. The device is comprised of a vibrating structure having first and second surfaces and having an associated resonant frequency and a wire coupled between the first and second surfaces of the vibrating structure, wherein the analyte interacts with the wire and causes a change in the resonant frequency of the vibrating structure. The vibrating structure can include a tuning fork. The vibrating structure can be comprised of quartz. The wire can be comprised of polymer. A plurality of vibrating structures are arranged in an array to increase confidence by promoting a redundancy of measurement or to detect a plurality of chemical analytes. A method of making a device for sensing a chemical analyte is also disclosed.

  15. Guidelines to improve airport preparedness against chemical and biological terrorism.

    SciTech Connect

    Edwards, Donna M.; Price, Phillip N.; Gordon, Susanna P.; Gadgil, Ashok

    2005-05-01

    Guidelines to Improve Airport Preparedness Against Chemical and Biological Terrorism is a 100-page document that makes concrete recommendations on improving security and assessing vulnerable areas and helps its readers understand the nature of chemical and biological attacks. The report has been turned over to Airports Council International (ACI) and the American Association of Airport Executives (AAAE), two organizations that together represent the interests of thousands of airport personnel and facilities in the U.S. and around the world.

  16. Chemically-functionalized microcantilevers for detection of chemical, biological and explosive material

    SciTech Connect

    Pinnaduwage, Lal A; Thundat, Thomas G; Brown, Gilbert M; Hawk, John Eric; Boiadjiev, Vassil I

    2007-04-24

    A chemically functionalized cantilever system has a cantilever coated on one side thereof with a reagent or biological species which binds to an analyte. The system is of particular value when the analyte is a toxic chemical biological warfare agent or an explosive.

  17. SOME CHEMICAL PROPERTIES UNDERLYING ARSENIC'S BIOLOGICAL ACTIVITY

    EPA Science Inventory

    ABSTRACT

    In this paper some of the chemical properties of arsenicals (atomic
    and molecular orbitals, electronegativity, valence state, changes between
    valence state, nucleophilicity, the hard/soft acid/base principle) that may
    account for some of the b...

  18. Chemical biology: Chromatin chemistry goes cellular

    NASA Astrophysics Data System (ADS)

    Fischle, Wolfgang; Schwarzer, Dirk; Mootz, Henning D.

    2015-05-01

    Analysing post-translational modifications of histone proteins as they occur within chromatin is challenging due to their large number and chemical diversity. A major step forward has now been achieved by using split intein chemistry to engineer functionalized histones within cells.

  19. Semi-volatile inorganic species: importance for atmospheric chemical composition on diurnal and seasonal timescales

    NASA Astrophysics Data System (ADS)

    Pearce, Hana; Mann, Graham; Arnold, Stephen; O'Connor, Fiona; Benduhn, Francois; Rumbold, Steven; Pringle, Kirsty

    2016-04-01

    Nitrate aerosol has become an important driver of reduced European air quality and climate forcing, following reductions in sulphate precursor emissions since the 1980s, and is expected to be more influential in future decades. Measurements from the European Integrated Project on Aerosol and Cloud Climate Air Quality Interactions (EUCAARI) field campaign have shown that semi-volatile aerosol species such as ammonium nitrate can comprise a major component of the sub-micron particulate matter, particularly in high pollution episodes. This presentation will assess the contribution of semi-volatile inorganic aerosol to diurnal and seasonal cycles in atmospheric chemical composition over Europe. We use the UM-UKCA composition-climate model, including the GLOMAP interactive aerosol microphysics module and a recently developed 'hybrid' dissolution solver (HyDis) to accurately represent size-resolved partitioning of ammonia and nitric acid to the particle phase. In particular, we evaluate simulated size-resolved composition variations over Europe through the diurnal cycle, comparing hourly model output to Aerosol Mass Spectrometer observations at several sites during 2008. We will present the results of this composition analysis, in addition to model evaluation from comparisons with European Monitoring for Environmental Protection (EMEP) network and EUCAARI field campaign observations.

  20. Non-essential metals in chemical biology.

    PubMed

    Dyson, Paul J

    2011-01-01

    Metal ions and compounds are essential to life and many people routinely take them as food supplements in the form of vitamin and mineral pills. Most non-essential metals are considered to be toxic, nevertheless, many are widely used in imaging, diagnostics and medicine. This short review provides an overview from selected examples of the on-going research within my laboratory that uses metal compounds to either understand biological processes or that exhibit therapeutic properties overcoming the limitations of existing chemotherapies.

  1. Air monitoring and detection of chemical and biological agents

    SciTech Connect

    Leonelli, J.; Althouse, M.L.

    1999-06-01

    This volume contains the proceedings of SPIE`s remote sensing symposium which was held November 2--3, 1998 in Boston, Massachusetts. Topics of discussion include the following: system simulations, atmospheric modeling, and performance prediction studies of chemical warfare remote sensing technologies; ultraviolet laser-induced fluorescence and aerosol detection methods for remote sensing of biological warfare agents; passive detection methods for remote detection of chemical warfare agents; and lidar-based system performance assessments, demonstrations, and new concepts for chemical warfare/biological warfare detection.

  2. Natural evidence for chemical and early biological evolution

    NASA Technical Reports Server (NTRS)

    Kvenvolden, K. A.

    1974-01-01

    Oparin (1924) and Haldane (1929) have independently hypothesized that life arose under reducing conditions through an evolutionary sequence of events involving increasingly complex organic substances. The natural evidence for this hypothesis of chemical evolution is considered, giving particular attention to tangible samples which have been chemically analyzed in earth-bound laboratories. It is found that meteorites provide naturally occurring evidence in support of chemical evolution, but not of biological evolution. Studies on the early Precambrian Swaziland Sequence and the Bulawayan System of southern Africa provide evidence for very early biological evolution.

  3. Waves and Patterns in Chemical and Biological Media

    NASA Astrophysics Data System (ADS)

    Swinney, Harry L.; Krinsky, Valentin I.

    1991-12-01

    These 28 contributions by leading researchers - from such diverse disciplines as chemistry, biology, physics, mathematics, and physiology - describe recent experiments, numerical simulations, and theoretical analyses of the formation of spatial patterns in chemical and biological systems. Chemical patterns have been systematically studied since the field was established by Alan Turing's landmark 1952 paper, "The chemical basis for morphogenesis," yet only recently have new experimental techniques and numerical analyses of reaction-diffusion equations opened the way to understanding stationary and traveling wave patterns. This collection summarizes the exciting developments in this rapidly growing field. It shows that some biological patterns have been found to be strikingly similar to patterns found in simple, well-controlled laboratory chemical systems, that new chemical reactor designs make it possible to sustain chemical patterns and to study transitions between different kinds of patterns, and that nearly 40 years after Turing's paper, the patterns predicted by Turing have finally been observed in laboratory experiments. Harry L. Swinney is Sid Richardson Foundation Regents Chair, Department of Physics, and Director of the Center for Nonlinear Dynamics at the University of Texas at Austin. Valentin I. Krinsky is Head of the Autowave Laboratory, Institute of Biological Physics, Academy of Sciences, Pushchino, USSR. Chapters cover: Spiral, Ring, and Scroll Patterns: Experiments. Spiral, Ring, and Scroll Patterns: Theory and Simulations. Fronts and Turing Patterns. Waves and Patterns in Biological Systems.

  4. Introduction: Applying Chemical Biology to Ion Channels.

    PubMed

    Pless, Stephan A; Ahern, Christopher A

    2015-01-01

    Ion channels are membrane-spanning proteins that control the flow of ions across biological membranes through an aqueous pathway. The opening or closing of this pore can be controlled by a myriad of physiological inputs (voltage, ligands, temperature, metabolites, pH), which in turn allow for the controlled flux of ions across membranes, resulting in the generation of minute electrical signals. The functional implications of ion channel function on physiological processes are vast. Electrical impulses, in the form of action potentials or diverse chemo-electrical signals, coordinate the syncytium of the heart beat, support a myriad of neuronal communication pathways, insulin secretion, and are central to the immune response, with more roles being discovered virtually everyday. Thus, ion channel function is a biophysical process that is central to biological life at many levels. And with over 500 channel-forming subunits known today in humans, this large class of proteins is also increasingly recognised as important drug targets, as inherited or acquired ion channel dysfunction are known causes of disease.

  5. Physical and chemical mechanisms in molecular radiation biology

    SciTech Connect

    Glass, W.A.; Varma, M.N.

    1991-01-01

    Through its Radiological and Chemical Physics Program, the Department of Energy (DOE) has been a primary source of funding for research in radiation physics and radiochemistry, supporting a wide range of explorations of the link between physical, chemical and biological events. This book is a series of articles by authors working within this field, most of whom have been central to the DOE-sponsored research. The opening papers focus on radiological physics; the second section covers radiation chemistry in a discussion that extends from the initial energy transfer to the production of intermediate chemical species and DNA damage. The third section explores the link between the physical and chemical events and the production of biological effects. Finally the book closes with a series of papers on molecular radiation biology.

  6. Enhanced formulations for neutralization of chemical, biological and industrial toxants

    DOEpatents

    Tucker, Mark D [Albuqueque, NM

    2008-06-24

    An enhanced formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The enhanced formulation according to the present invention is non-toxic and non-corrosive and can be delivered by a variety of means and in different phases. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator and water.

  7. 76 FR 68809 - Bureau of International Security and Nonproliferation; Termination of Chemical and Biological...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ... Nonproliferation; Termination of Chemical and Biological Weapons (CBW) Proliferation Sanctions Against a Foreign... government, project, or entity in its efforts to acquire chemical or biological weapons capability:...

  8. The chemical biology of hydropersulfides (RSSH): Chemical stability, reactivity and redox roles.

    PubMed

    Saund, Simran S; Sosa, Victor; Henriquez, Stephanie; Nguyen, Q Nhu N; Bianco, Christopher L; Soeda, Shuhei; Millikin, Robert; White, Corey; Le, Henry; Ono, Katsuhiko; Tantillo, Dean J; Kumagai, Yoshito; Akaike, Takaaki; Lin, Joseph; Fukuto, Jon M

    2015-12-15

    Recent reports indicate the ubiquitous prevalence of hydropersulfides (RSSH) in mammalian systems. The biological utility of these and related species is currently a matter of significant speculation. The function, lifetime and fate of hydropersulfides will be assuredly based on their chemical properties and reactivity. Thus, to serve as the basis for further mechanistic studies regarding hydropersulfide biology, some of the basic chemical properties/reactivity of hydropersulfides was studied. The nucleophilicity, electrophilicity and redox properties of hydropersulfides were examined under biological conditions. These studies indicate that hydropersulfides can be nucleophilic or electrophilic, depending on the pH (i.e. the protonation state) and can act as good one- and two-electron reductants. These diverse chemical properties in a single species make hydropersulfides chemically distinct from other, well-known sulfur containing biological species, giving them unique and potentially important biological function.

  9. Solid-water detoxifying reagents for chemical and biological agents

    DOEpatents

    Hoffman, Dennis M.; Chiu, Ing Lap

    2006-04-18

    Formation of solid-water detoxifying reagents for chemical and biological agents. Solutions of detoxifying reagent for chemical and biological agents are coated using small quantities of hydrophobic nanoparticles by vigorous agitation or by aerosolization of the solution in the presence of the hydrophobic nanoparticles to form a solid powder. For example, when hydrophobic fumed silica particles are shaken in the presence of IN oxone solution in approximately a 95:5-weight ratio, a dry powder results. The hydrophobic silica forms a porous coating of insoluble fine particles around the solution. Since the chemical or biological agent tends to be hydrophobic on contact with the weakly encapsulated detoxifying solution, the porous coating breaks down and the detoxifying reagent is delivered directly to the chemical or biological agent for maximum concentration at the point of need. The solid-water (coated) detoxifying solutions can be blown into contaminated ventilation ducting or other difficult to reach sites for detoxification of pools of chemical or biological agent. Once the agent has been detoxified, it can be removed by flushing the area with air or other techniques.

  10. Delivering The Benefits of Chemical-Biological Integration in ...

    EPA Pesticide Factsheets

    Abstract: Researchers at the EPA’s National Center for Computational Toxicology integrate advances in biology, chemistry, and computer science to examine the toxicity of chemicals and help prioritize chemicals for further research based on potential human health risks. The intention of this research program is to quickly evaluate thousands of chemicals for potential risk but with much reduced cost relative to historical approaches. This work involves computational and data driven approaches including high-throughput screening, modeling, text-mining and the integration of chemistry, exposure and biological data. We have developed a number of databases and applications that are delivering on the vision of developing a deeper understanding of chemicals and their effects on exposure and biological processes that are supporting a large community of scientists in their research efforts. This presentation will provide an overview of our work to bring together diverse large scale data from the chemical and biological domains, our approaches to integrate and disseminate these data, and the delivery of models supporting computational toxicology. This abstract does not reflect U.S. EPA policy. Presentation at ACS TOXI session on Computational Chemistry and Toxicology in Chemical Discovery and Assessement (QSARs).

  11. The electrochemical properties of the purine bases : at the interface between biological conjugates to inorganic surfaces

    NASA Technical Reports Server (NTRS)

    Hays, Charles C.

    2003-01-01

    The study of the charge transfer and interfacial reactions of the purine bases in physiological solutions provides valuable knowledge, as these processes are relevant to the origins of life. It has been proposed that the adsorption of the adsorption of the purine bases on an inorganic surface could serve as a template for specifying the arrangement of amino acids in peptides.

  12. The origin of biological macromolecules on the earth. The hypothesis of inorganic template

    NASA Technical Reports Server (NTRS)

    Lu, T. S.

    1977-01-01

    Studies about the origin of life are reviewed. The nonrandom organization of organelles is discussed from a structural and functional point of view. After postulating that the origin of biomacromolecules was not a random event, the paper develops the hypothesis that polypeptides and polynucleotides were formed on an inorganic template. Only information-containing structures can pass natural selection and develop through evolution.

  13. Formulations for neutralization of chemical and biological toxants

    DOEpatents

    Tadros, Maher E.; Tucker, Mark D.

    2003-05-20

    A formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents. The formulation of the present invention non-toxic and non-corrosive and can be delivered by a variety of means and in different phases. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The at least one reactive compound can be an oxidizing compound, a nucleophilic compound or a mixture of both. The formulation can kill up to 99.99999% of bacterial spores within one hour of exposure.

  14. Chemical and biological nonproliferation program. FY99 annual report

    SciTech Connect

    2000-03-01

    This document is the first of what will become an annual report documenting the progress made by the Chemical and Biological Nonproliferation Program (CBNP). It is intended to be a summary of the program's activities that will be of interest to both policy and technical audiences. This report and the annual CBNP Summer Review Meeting are important vehicles for communication with the broader chemical and biological defense and nonproliferation communities. The Chemical and Biological Nonproliferation Program Strategic Plan is also available and provides additional detail on the program's context and goals. The body of the report consists of an overview of the program's philosophy, goals and recent progress in the major program areas. In addition, an appendix is provided with more detailed project summaries that will be of interest to the technical community.

  15. Persulfides: Current Knowledge and Challenges in Chemistry and Chemical Biology

    PubMed Central

    Park, Chung-Min; Weerasinghe, Laksiri; Day, Jacob J.; Fukuto, Jon M.; Xian, Ming

    2015-01-01

    Recent studies conducted in hydrogen sulfide (H2S) signaling have revealed potential importance of persulfides (RSSH) in redox biology. The inherent instability of RSSH makes these species difficult to study and sometimes controversial results are reported. In this review article we summarize known knowledge about both small molecule persulfides and protein persulfides. Their fundamental physical and chemical properties such as preparation/formation and reactivity are discussed. The biological implications of persulfides and their detection methods are also discussed. PMID:25969163

  16. Chemical Biology Probes from Advanced DNA-encoded Libraries.

    PubMed

    Salamon, Hazem; Klika Škopić, Mateja; Jung, Kathrin; Bugain, Olivia; Brunschweiger, Andreas

    2016-02-19

    The identification of bioactive compounds is a crucial step toward development of probes for chemical biology studies. Screening of DNA-encoded small molecule libraries (DELs) has emerged as a validated technology to interrogate vast chemical space. DELs consist of chimeric molecules composed of a low-molecular weight compound that is conjugated to a DNA identifier tag. They are screened as pooled libraries using selection to identify "hits." Screening of DELs has identified numerous bioactive compounds. Some of these molecules were instrumental in gaining a deeper understanding of biological systems. One of the main challenges in the field is the development of synthesis methodology for DELs.

  17. Signal Processing For Chemical Sensing: Statistics or Biological Inspiration

    NASA Astrophysics Data System (ADS)

    Marco, Santiago

    2011-09-01

    Current analytical instrumentation and continuous sensing can provide huge amounts of data. Automatic signal processing and information evaluation is needed to overcome drowning in data. Today, statistical techniques are typically used to analyse and extract information from continuous signals. However, it is very interesting to note that biology (insects and vertebrates) has found alternative solutions for chemical sensing and information processing. This is a brief introduction to the developments in the European Project: Bio-ICT NEUROCHEM: Biologically Inspired Computation for Chemical Sensing (grant no. 216916) Fp7 project devoted to biomimetic olfactory systems.

  18. Concentrated formulations and methods for neutralizing chemical and biological toxants

    DOEpatents

    Tucker, Mark D.; Betty, Rita G.; Tadros, Maher E.

    2004-04-20

    A formulation and method of making and using that neutralizes the adverse health effects of both chemical and biological toxants, especially chemical warfare (CW) and biological warfare (BW) agents. The aqueous formulation is non-toxic and non-corrosive and can be delivered as a long-lasting foam, spray, or fog. The formulation includes solubilizing compounds that serve to effectively render the CW or BW toxant susceptible to attack, so that a nucleophillic agent can attack the compound via a hydrolysis or oxidation reaction. The formulation can kill up to 99.99999% of bacterial spores within one hour of exposure.

  19. Chemical and biological weapons: new questions, new answers.

    PubMed Central

    Hood, E

    1999-01-01

    The words "chemical and biological weapons" (CBW) send a shiver down most spines these days. With the end of the Cold War, the possibility of a massive nuclear confrontation appears remote, so today many popular doomsday scenarios center on the aggressive use of chemical or biological warfare by rogue nations or terrorist groups. As exaggerated as some of the accounts are, with CBW cast as the latest unseen, unstoppable enemy, the threat posed by these weapons is all too real, and growing. Images p931-a PMID:10585899

  20. Synthesis of silver nanoparticles: chemical, physical and biological methods

    PubMed Central

    Iravani, S.; Korbekandi, H.; Mirmohammadi, S.V.; Zolfaghari, B.

    2014-01-01

    Silver nanoparticles (NPs) have been the subjects of researchers because of their unique properties (e.g., size and shape depending optical, antimicrobial, and electrical properties). A variety of preparation techniques have been reported for the synthesis of silver NPs; notable examples include, laser ablation, gamma irradiation, electron irradiation, chemical reduction, photochemical methods, microwave processing, and biological synthetic methods. This review presents an overview of silver nanoparticle preparation by physical, chemical, and biological synthesis. The aim of this review article is, therefore, to reflect on the current state and future prospects, especially the potentials and limitations of the above mentioned techniques for industries. PMID:26339255

  1. Chemical master equation closure for computer-aided synthetic biology.

    PubMed

    Smadbeck, Patrick; Kaznessis, Yiannis N

    2015-01-01

    With inexpensive DNA synthesis technologies, we can now construct biological systems by quickly piecing together DNA sequences. Synthetic biology is the promising discipline that focuses on the construction of these new biological systems. Synthetic biology is an engineering discipline, and as such, it can benefit from mathematical modeling. This chapter focuses on mathematical models of biological systems. These models take the form of chemical reaction networks. The importance of stochasticity is discussed and methods to simulate stochastic reaction networks are reviewed. A closure scheme solution is also presented for the master equation of chemical reaction networks. The master equation is a complete model of randomly evolving molecular populations. Because of its ambitious character, the master equation remained unsolved for all but the simplest of molecular interaction networks for over 70 years. With the first complete solution of chemical master equations, a wide range of experimental observations of biomolecular interactions may be mathematically conceptualized. We anticipate that models based on the closure scheme described herein may assist in rationally designing synthetic biological systems.

  2. Chemical Master Equation Closure for Computer-Aided Synthetic Biology

    PubMed Central

    Smadbeck, Patrick; Kaznessis, Yiannis N.

    2016-01-01

    SUMMARY With inexpensive DNA synthesis technologies, we can now construct biological systems by quickly piecing together DNA sequences. Synthetic biology is the promising discipline that focuses on the construction of these new biological systems. Synthetic biology is an engineering discipline, and as such, it can benefit from mathematical modeling. This chapter focuses on mathematical models of biological systems. These models take the form of chemical reaction networks. The importance of stochasticity is discussed and methods to simulate stochastic reaction networks are reviewed. A closure scheme solution is also presented for the master equation of chemical reaction networks. The master equation is a complete model of randomly evolving molecular populations. Because of its ambitious character, the master equation remained unsolved for all but the simplest of molecular interaction networks for over seventy years. With the first complete solution of chemical master equations, a wide range of experimental observations of biomolecular interactions may be mathematically conceptualized. We anticipate that models based on the closure scheme described herein may assist in rationally designing synthetic biological systems. PMID:25487098

  3. The stoichiometric ratio during biological removal of inorganic carbon and nutrient in the Mississippi River plume and adjacent continental shelf

    NASA Astrophysics Data System (ADS)

    Huang, W.-J.; Cai, W.-J.; Powell, R. T.; Lohrenz, S. E.; Wang, Y.; Jiang, L.-Q.; Hopkinson, C. S.

    2012-02-01

    The stoichiometric ratios of dissolved inorganic carbon (DIC) and nutrients during biological removal have been widely assumed to follow the Redfield ratios (especially the C/N ratio) in large river plume ecosystems. However, this assumption has not been systematically examined and documented because DIC and nutrients are rarely studied simultaneously in a river plume area, a region in which they can be affected by strong river-ocean mixing as well as intense biological activity. We examined stoichiometric ratios of DIC, total alkalinity (TA), and nutrients (NO3, PO43- and Si(OH)4) data during biological removal in the Mississippi River plume and adjacent continental shelf in June 2003 and August 2004 with biological removals defined as the difference between measured values and values predicted on the basis of conservative mixing determined using a multi-endmember mixing model. Despite complex physical and biogeochemical influences, relationships between DIC and nutrients were strongly dependent on salinity range and geographic location, and influenced by biological removal. Lower C/Si and N/Si ratios in one nearshore area were attributed to a potential silicate source induced by water exchange with coastal salt marshes. When net biological uptake was separated from river-ocean mixing and the impact of marshes and bays excluded, stoichiometric ratios of C/N/Si were similar to the Redfield ratios, thus supporting the applicability of the Redfield-type C/N/Si ratios as a principle in river-plume biogeochemical models.

  4. Smart Phones: Platform Enabling Modular, Chemical, Biological, and Explosives Sensing

    DTIC Science & Technology

    2013-07-01

    solar - blind reagentless standoff chemical, biological, and explosives (CBE) sensor,” Proc. SPIE, 6954, 69540I/1-69540I/9 (2008). [4] K. J. Morey, M...automated field deployable biochemical detector has been designed and implemented using smart phone technology to augment this decision making process...The detection unit is a binary detector that indicates the presence or non-presence of the chemical target of interest. The operating procedure of

  5. Chemical synthesis and biological function of lipidated proteins.

    PubMed

    Yang, Aimin; Zhao, Lei; Wu, Yao-Wen

    2015-01-01

    Lipidated proteins play a key role in many essential biological processes in eukaryotic cells, including signal transduction, membrane trafficking, immune response and pathology. The investigation of the function of lipidated proteins requires access to a reasonable amount of homogenous lipid-modified proteins with defined structures and functional groups. Chemical approaches have provided useful tools to perform such studies. In this review we summarize synthetic methods of lipidated peptides and developments in the chemoselective ligation for the production of lipidated proteins. We introduce the biology of lipidated proteins and highlight the application of synthetic lipidated proteins to tackle important biological questions.

  6. Modelling biological and chemically induced precipitation of calcium phosphate in enhanced biological phosphorus removal systems.

    PubMed

    Barat, R; Montoya, T; Seco, A; Ferrer, J

    2011-06-01

    The biologically induced precipitation processes can be important in wastewater treatment, in particular treating raw wastewater with high calcium concentration combined with Enhanced Biological Phosphorus Removal. Currently, there is little information and experience in modelling jointly biological and chemical processes. This paper presents a calcium phosphate precipitation model and its inclusion in the Activated Sludge Model No 2d (ASM2d). The proposed precipitation model considers that aqueous phase reactions quickly achieve the chemical equilibrium and that aqueous-solid change is kinetically governed. The model was calibrated using data from four experiments in a Sequencing Batch Reactor (SBR) operated for EBPR and finally validated with two experiments. The precipitation model proposed was able to reproduce the dynamics of amorphous calcium phosphate (ACP) formation and later crystallization to hydroxyapatite (HAP) under different scenarios. The model successfully characterised the EBPR performance of the SBR, including the biological, physical and chemical processes.

  7. Integrated chemical-biological treatment of benzo[a]pyrene

    SciTech Connect

    Zeng, Yu; Hong, P.K.A.; Wavrek, D.A.

    2000-03-01

    Benzo[a]pyrene of natural and anthropogenic sources is one of the toxic, mutagenic, polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants. This study focuses on an integrated treatment of benzo[a]pyrene involving sequential chemical oxidation and biological degradation. The objectives are to (1) provide mechanistic details in the ozone-mediated degradation of benzo[a]pyrene in the aqueous phase, (2) test the biodegradability of resultant intermediates, and (3) test the feasibility for the coupled chemical-biological treatment of the five-ring PAH. Batch and packed column reactors were used to examine the degradation pathways of benzo[a]pyrene subject to ozonation in the aqueous phase. After different ozonation times, samples containing reaction intermediates and byproducts from both reactors were collected, identified for organic contents, and further biologically inoculated to determine their biodegradability. The O{sub 3}-pretreated samples were incubated for 5, 10, 15, and 20 days; afterward biochemical oxygen demand (BOD), chemical oxygen demand (COD), and E. coli toxicity tests were conducted along with qualitative and quantitative determinations of benzo[a]pyrene, intermediates, and reaction products by GC/FID and GC/MS methods. Prevalent intermediates identified at different stages included ring-opened aldehydes, phthalic derivatives, and aliphatics. The degradation of benzo[a]pyrene is primarily initiated via O{sub 3}-mediated ring-opening, followed by O{sub 3} and hydroxyl radical fragmentation, and ultimately brought to complete mineralization primarily via hydroxyl radicals. Intermediates formed during chemical oxidation were biodegradable with a measured first-order rate constant (k{sub 0}) of 0.18 day{sup {minus}1}. The integrated chemical-biological system seems feasible for treating recalcitrant compounds, while pretreatment by chemical oxidation appears useful in promoting soluble intermediates from otherwise highly insoluble

  8. Chemical and biological weapons in the 'new wars'.

    PubMed

    Ilchmann, Kai; Revill, James

    2014-09-01

    The strategic use of disease and poison in warfare has been subject to a longstanding and cross-cultural taboo that condemns the hostile exploitation of poisons and disease as the act of a pariah. In short, biological and chemical weapons are simply not fair game. The normative opprobrium is, however, not fixed, but context dependent and, as a social phenomenon, remains subject to erosion by social (or more specifically, antisocial) actors. The cross cultural understanding that fighting with poisons and disease is reprehensible, that they are taboo, is codified through a web of interconnected measures, principal amongst these are the 1925 Geneva Protocol; the Biological Weapons Convention; and the Chemical Weapons Convention. Whilst these treaties have weathered the storm of international events reasonably well, their continued health is premised on their being 'tended to' in the face of contextual changes, particularly facing changes in science and technology, as well as the changed nature and character of conflict. This article looks at the potential for normative erosion of the norm against chemical and biological weapons in the face of these contextual changes and the creeping legitimization of chemical and biological weapons.

  9. Guide to Using Drugs, Biologics, and Other Chemicals in Aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Guide to Using Drugs, Biologics, and Other Chemicals in Aquaculture (Guide) describes regulated products that are approved for use in U.S. aquaculture. The Guide also describes drugs that are not yet approved for use in the U. S. but that can be used under an Investigational New Animal Drug (INA...

  10. Prepare Your School for Chemical, Biological, and Radiological Threats

    ERIC Educational Resources Information Center

    Sechena, Ruth

    2005-01-01

    Recent accidents highlight that chemical, biological, and radiological (CBR) agent exposure risk isn't just about terrorism. In this article, the author, a parent and public health physician, wrestles with the fact that total protection from CBRs is probably not feasible in her son's or in the majority of American schools. Capital investments, for…

  11. Role of natural product diversity in chemical biology.

    PubMed

    Hong, Jiyong

    2011-06-01

    Through the natural selection process, natural products possess a unique and vast chemical diversity and have been evolved for optimal interactions with biological macromolecules. Owing to their diversity, target affinity, and specificity, natural products have demonstrated enormous potential as modulators of biomolecular function, been an essential source for drug discovery, and provided design principles for combinatorial library development.

  12. A decontamination study of simulated chemical and biological agents

    SciTech Connect

    Uhm, Han S.; Lee, Han Y.; Hong, Yong C.; Shin, Dong H.; Park, Yun H.; Hong, Yi F.; Lee, Chong K.

    2007-07-01

    A comprehensive decontamination scheme of the chemical and biological agents, including airborne agents and surface contaminating agents, is presented. When a chemical and biological attack occurs, it is critical to decontaminate facilities or equipments to an acceptable level in a very short time. The plasma flame presented here may provide a rapid and effective elimination of toxic substances in the interior air in isolated spaces. As an example, a reaction chamber, with the dimensions of a 22 cm diameter and 30 cm length, purifies air with an airflow rate of 5000 l/min contaminated with toluene, the simulated chemical agent, and soot from a diesel engine, the simulated aerosol for biological agents. Although the airborne agents in an isolated space are eliminated to an acceptable level by the plasma flame, the decontamination of the chemical and biological agents cannot be completed without cleaning surfaces of the facilities. A simulated sterilization study of micro-organisms was carried out using the electrolyzed ozone water. The electrolyzed ozone water very effectively kills endospores of Bacillus atrophaeus (ATCC 9372) within 3 min. The electrolyzed ozone water also kills the vegetative micro-organisms, fungi, and virus. The electrolyzed ozone water, after the decontamination process, disintegrates into ordinary water and oxygen without any trace of harmful materials to the environment.

  13. A decontamination study of simulated chemical and biological agents

    NASA Astrophysics Data System (ADS)

    Uhm, Han S.; Lee, Han Y.; Hong, Yong C.; Shin, Dong H.; Park, Yun H.; Hong, Yi F.; Lee, Chong K.

    2007-07-01

    A comprehensive decontamination scheme of the chemical and biological agents, including airborne agents and surface contaminating agents, is presented. When a chemical and biological attack occurs, it is critical to decontaminate facilities or equipments to an acceptable level in a very short time. The plasma flame presented here may provide a rapid and effective elimination of toxic substances in the interior air in isolated spaces. As an example, a reaction chamber, with the dimensions of a 22cm diameter and 30cm length, purifies air with an airflow rate of 5000l/min contaminated with toluene, the simulated chemical agent, and soot from a diesel engine, the simulated aerosol for biological agents. Although the airborne agents in an isolated space are eliminated to an acceptable level by the plasma flame, the decontamination of the chemical and biological agents cannot be completed without cleaning surfaces of the facilities. A simulated sterilization study of micro-organisms was carried out using the electrolyzed ozone water. The electrolyzed ozone water very effectively kills endospores of Bacillus atrophaeus (ATCC 9372) within 3min. The electrolyzed ozone water also kills the vegetative micro-organisms, fungi, and virus. The electrolyzed ozone water, after the decontamination process, disintegrates into ordinary water and oxygen without any trace of harmful materials to the environment.

  14. [Biological denoxation of chemical pathogens in aqueous medium].

    PubMed

    Globa, L I; Gvozdiak, P I

    2015-01-01

    There are considered possibilities and perspectives of denoxation (decontamination) of chemical pathogens by means of biological methods for the environment sanitation and protection from contamination. There are presented numerous examples of successful practical application of the modern biotechnologies in industrial sewage denoxation from xenobiotics.

  15. Opportunities for synthetic biology in antibiotics: expanding glycopeptide chemical diversity.

    PubMed

    Thaker, Maulik N; Wright, Gerard D

    2015-03-20

    Synthetic biology offers a new path for the exploitation and improvement of natural products to address the growing crisis in antibiotic resistance. All antibiotics in clinical use are facing eventual obsolesce as a result of the evolution and dissemination of resistance mechanisms, yet there are few new drug leads forthcoming from the pharmaceutical sector. Natural products of microbial origin have proven over the past 70 years to be the wellspring of antimicrobial drugs. Harnessing synthetic biology thinking and strategies can provide new molecules and expand chemical diversity of known antibiotic scaffolds to provide much needed new drug leads. The glycopeptide antibiotics offer paradigmatic scaffolds suitable for such an approach. We review these strategies here using the glycopeptides as an example and demonstrate how synthetic biology can expand antibiotic chemical diversity to help address the growing resistance crisis.

  16. Considerations for designing chemical screening strategies in plant biology

    PubMed Central

    Serrano, Mario; Kombrink, Erich; Meesters, Christian

    2015-01-01

    Traditionally, biologists regularly used classical genetic approaches to characterize and dissect plant processes. However, this strategy is often impaired by redundancy, lethality or pleiotropy of gene functions, which prevent the isolation of viable mutants. The chemical genetic approach has been recognized as an alternative experimental strategy, which has the potential to circumvent these problems. It relies on the capacity of small molecules to modify biological processes by specific binding to protein target(s), thereby conditionally modifying protein function(s), which phenotypically resemble mutation(s) of the encoding gene(s). A successful chemical screening campaign comprises three equally important elements: (1) a reliable, robust, and quantitative bioassay, which allows to distinguish between potent and less potent compounds, (2) a rigorous validation process for candidate compounds to establish their selectivity, and (3) an experimental strategy for elucidating a compound's mode of action and molecular target. In this review we will discuss details of this general strategy and additional aspects that deserve consideration in order to take full advantage of the power provided by the chemical approach to plant biology. In addition, we will highlight some success stories of recent chemical screenings in plant systems, which may serve as teaching examples for the implementation of future chemical biology projects. PMID:25904921

  17. Organic thin-film transistors for chemical and biological sensing.

    PubMed

    Lin, Peng; Yan, Feng

    2012-01-03

    Organic thin-film transistors (OTFTs) show promising applications in various chemical and biological sensors. The advantages of OTFT-based sensors include high sensitivity, low cost, easy fabrication, flexibility and biocompatibility. In this paper, we review the chemical sensors and biosensors based on two types of OTFTs, including organic field-effect transistors (OFETs) and organic electrochemical transistors (OECTs), mainly focusing on the papers published in the past 10 years. Various types of OTFT-based sensors, including pH, ion, glucose, DNA, enzyme, antibody-antigen, cell-based sensors, dopamine sensor, etc., are classified and described in the paper in sequence. The sensing mechanisms and the detection limits of the devices are described in details. It is expected that OTFTs may have more important applications in chemical and biological sensing with the development of organic electronics.

  18. New approaches in data integration for systems chemical biology.

    PubMed

    Seoane, Jose A; López-Campos, Guillermo; Dorado, Julian; Martin-Sanchez, Fernando

    2013-01-01

    Advances done in "-Omics" technologies in the last 20 years have made available to the researches huge amounts of data spanning a wide variety of biological processes from gene sequences to the metabolites present in a cell at a particular time. The management, analysis and representation of these data have been facilitated by mean of the advances made by biomedical informatics in areas such as data architecture and integration systems. However, despite the efforts done by biologists in this area, research in drug design adds a new level of information by incorporating data related with small molecules, which increases the complexity of these integration systems. Current knowledge in molecular biology has shown that it is possible to use comprehensive and integrative approaches to understand the biological processes from a systems perspective and that pathological processes can be mapped into biological networks. Therefore, current strategies for drug design are focusing on how to interact with or modify those networks to achieve the desired effects on what is called systems chemical biology. In this review several approaches for data integration in systems chemical biology will be analysed and described. Furthermore, because of the increasing relevance of the development and use of nanomaterials and their expected impact in the near future, the requirements of integration systems that incorporate these new data types associated with nanomaterials will also be analysed.

  19. 40 CFR 141.23 - Inorganic chemical sampling and analytical requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Inorganic Contaminants Contaminant MCL (mg/l) Methodology Detection limit (mg/l) Antimony 0.006 Atomic Absorption; Furnace 0.003 Atomic Absorption; Platform 0.0008 5 ICP-Mass Spectrometry 0.0004 Hydride-Atomic Absorption 0.001 Arsenic 0.010 6 Atomic Absorption; Furnace 0.001 Atomic Absorption;...

  20. 40 CFR 141.23 - Inorganic chemical sampling and analytical requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Inorganic Contaminants Contaminant MCL (mg/l) Methodology Detection limit (mg/l) Antimony 0.006 Atomic Absorption; Furnace 0.003 Atomic Absorption; Platform 0.0008 5 ICP-Mass Spectrometry 0.0004 Hydride-Atomic Absorption 0.001 Arsenic 0.010 6 Atomic Absorption; Furnace 0.001 Atomic Absorption;...

  1. 40 CFR 141.23 - Inorganic chemical sampling and analytical requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Inorganic Contaminants Contaminant MCL (mg/l) Methodology Detection limit (mg/l) Antimony 0.006 Atomic Absorption; Furnace 0.003 Atomic Absorption; Platform 0.0008 5 ICP-Mass Spectrometry 0.0004 Hydride-Atomic Absorption 0.001 Arsenic 0.010 6 Atomic Absorption; Furnace 0.001 Atomic Absorption;...

  2. 40 CFR 141.23 - Inorganic chemical sampling and analytical requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Inorganic Contaminants Contaminant MCL (mg/l) Methodology Detection limit (mg/l) Antimony 0.006 Atomic Absorption; Furnace 0.003 Atomic Absorption; Platform 0.0008 5 ICP-Mass Spectrometry 0.0004 Hydride-Atomic Absorption 0.001 Arsenic 0.010 6 Atomic Absorption; Furnace 0.001 Atomic Absorption;...

  3. 40 CFR 141.23 - Inorganic chemical sampling and analytical requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Inorganic Contaminants Contaminant MCL (mg/l) Methodology Detection limit (mg/l) Antimony 0.006 Atomic Absorption; Furnace 0.003 Atomic Absorption; Platform 0.0008 5 ICP-Mass Spectrometry 0.0004 Hydride-Atomic Absorption 0.001 Arsenic 0.010 6 Atomic Absorption; Furnace 0.001 Atomic Absorption;...

  4. Arsenic, inorganic

    Integrated Risk Information System (IRIS)

    Arsenic , inorganic ; CASRN 7440 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  5. Removal of Pesticides and Inorganic Contaminants in Anaerobic and Aerobic Biological Contactors

    EPA Science Inventory

    This presentation contains data on the removal of pesticides (acetochlor, clethodim, dicrotophos), ammonia, nitrate, bromate and perchlorate through aerobic and anaerobic biological treatment processes.

  6. Organic chemistry and biology: chemical biology through the eyes of collaboration.

    PubMed

    Hruby, Victor J

    2009-12-18

    From a scientific perspective, efforts to understand biology including what constitutes health and disease has become a chemical problem. However, chemists and biologists "see" the problems of understanding biology from different perspectives, and this has retarded progress in solving the problems especially as they relate to health and disease. This suggests that close collaboration between chemists and biologists is not only necessary but essential for progress in both the biology and chemistry that will provide solutions to the global questions of biology. This perspective has directed my scientific efforts for the past 45 years, and in this overview I provide my perspective of how the applications of synthetic chemistry, structural design, and numerous other chemical principles have intersected in my collaborations with biologists to provide new tools, new science, and new insights that were only made possible and fruitful by these collaborations.

  7. Preparedness for terrorism: managing nuclear, biological and chemical threats.

    PubMed

    Koenig, Kristi L

    2009-12-01

    The management of nuclear, biological and chemical (NBC) terrorism events is critical to reducing morbidity and mortality in the next decade; however, initial patient care considerations and protective actions for staff are unfamiliar to most front-line clinicians. High explosive events (bomb and blast) remain the most common type of terrorism and are easy to detect. Conversely, some types of terrorist attacks are more likely to be unsuspected or covert. This paper explains the current threat of terrorism and describes clues for detection that an event has occurred. Specific criteria that should lead to a high suspicion for terrorism are illustrated. The manuscript outlines initial actions and clinical priorities for management and treatment of patients exposed to nuclear/radiological, biological, chemical and combined agents (for example an explosion involving a chemical agent). Examples of terrorist events include: a nuclear explosion, an aerosolised release of anthrax (biological), dissemination of sarin in a subway (chemical), and the detonation of a radiologic dispersion device or "dirty bomb" (combined explosive and radiological). Basic principles of decontamination include potential risks to healthcare providers from secondary exposure and contamination. Unique issues may hinder clinical actions. These include coordination with law enforcement for a crime scene, public health entities for surveillance and monitoring, hazardous materials teams for decontamination, and the media for risk communications. Finally, the importance of personal preparedness is discussed.

  8. Linking chemical contamination to biological effects in coastal pollution monitoring.

    PubMed

    Beiras, Ricardo; Durán, Iria; Parra, Santiago; Urrutia, Miren B; Besada, Victoria; Bellas, Juan; Viñas, Lucía; Sánchez-Marín, Paula; González-Quijano, Amelia; Franco, María A; Nieto, Óscar; González, Juan J

    2012-01-01

    To establish the connection between pollutant levels and their harmful effects on living resources, coastal monitoring programmes have incorporated biological tools, such as the scope for growth (SFG) in marine mussels and benthic macrofauna community indices. Although the relation between oxygen-depleting anthropogenic inputs and the alteration of benthic communities is well described, the effects of chemical pollutants are unknown because they are not expected to favour any particular taxa. In this study, the combined efforts of five research teams involved in the investigative monitoring of marine pollution allowed the generation of a multiyear data set for Ría de Vigo (NW Iberian Peninsula). Multivariate analysis of these data allowed the identification of the chemical-matrix combinations responsible for most of the variability among sites and the construction of a chemical pollution index (CPI) that significantly (P < 0.01) correlated with biological effects at both the individual and the community levels. We report a consistent reduction in the physiological fitness of local populations of mussels as chemical pollution increases. The energy balance was more sensitive to pollution than individual physiological rates, but the reduction in the SFG was primarily due to significantly decreased clearance rates. We also found a decrease in benthic macrofauna diversity as chemical pollution increases. This diversity reduction resulted not from altered evenness, as the classic paradigm might suggest, but from a loss of species richness.

  9. Methods for the rapid detection of biological and chemical weapons

    SciTech Connect

    Castro, A.; Hemberger, P.H.; Swanson, B.I.

    1997-08-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). This work undertook the development of technology for the detection of chemical and biological agents. The project consisted of three tasks: (1) modifying a transportable mass spectrometer for the detection of chemical gents; (2) demonstrating the detection of a specific bacterial DNA sequence using a fluorescence-based single- copy gene detector; and (3) upgrading a surface acoustic wave measurement station.

  10. One species, many terpenes: matching chemical and biological diversity.

    PubMed

    Loreto, Francesco; Bagnoli, Francesca; Fineschi, Silvia

    2009-08-01

    Volatile terpenes have been proposed as chemotaxonomic markers, despite the strong environmental control on their synthesis. To clarify whether chemical profiles match biological diversity, cork oak, a monoterpene-emitting species that has been bred by humans and frequently hybridizes with other oaks, is a useful case-study. Analysis of the available genetic information in cork oak provenances suggests that volatile terpenes might indeed suitably track geographical diversity even at the intraspecific level. Phylogeographical diversity does not reflect chemical diversity in other evergreen oaks that have not been intensively bred. Breeding for productive traits might therefore drive selection for terpene diversity, in turn modulating important adaptive mechanisms against biotic and abiotic stressors.

  11. Combined chemical and biological treatment of oil contaminated soil.

    PubMed

    Goi, Anna; Kulik, Niina; Trapido, Marina

    2006-06-01

    Combined chemical (Fenton-like and ozonation) and biological treatment for the remediation of shale oil and transformer oil contaminated soil has been under study. Chemical treatment of shale oil and transformer oil adsorbed in peat resulted in lower contaminants' removal and required higher addition of chemicals than chemical treatment of contaminants in sand matrix. The acidic pH (3.0) conditions favoured Fenton-like oxidation of oil in soil. Nevertheless, it was concluded that remediation of contaminated soil using in situ Fenton-like treatment will be more feasible at natural soil pH. Both investigated chemical processes (Fenton-like and ozonation) allowed improving the subsequent biodegradability of oil. Moderate doses of chemical oxidants (hydrogen peroxide, ozone) should be applied in combination of chemical treatment (both, Fenton-like or ozonation) and biotreatment. For remediation of transformer oil and shale oil contaminated soil Fenton-like pre-treatment followed by biodegradation was found to be the most efficient.

  12. Solution-gated graphene transistors for chemical and biological sensors.

    PubMed

    Yan, Feng; Zhang, Meng; Li, Jinhua

    2014-03-01

    Graphene has attracted much attention in biomedical applications for its fascinating properties. Because of the well-known 2D structure, every atom of graphene is exposed to the environment, so the electronic properties of graphene are very sensitive to charged analytes (ions, DNA, cells, etc.) or an electric field around it, which renders graphene an ideal material for high-performance sensors. Solution-gated graphene transistors (SGGTs) can operate in electrolytes and are thus excellent candidates for chemical and biological sensors, which have been extensively studied in the recent 5 years. Here, the device physics, the sensing mechanisms, and the performance of the recently developed SGGT-based chemical and biological sensors, including pH, ion, cell, bacterial, DNA, protein, glucose sensors, etc., are introduced. Their advantages and shortcomings, in comparison with some conventional techniques, are discussed. Conclusions and challenges for the future development of the field are addressed in the end.

  13. Monitoring the inorganic chemical reaction by surface-enhanced Raman spectroscopy: A case of Fe³⁺ to Fe²⁺ conversion.

    PubMed

    Qin, Suhua; Meng, Juan; Tang, Xianghu; Yang, Liangbao

    2016-01-01

    Monitoring the process of organic chemical reactions to study the kinetics by surface-enhanced Raman spectroscopy (SERS) is currently of immense interest. However, monitoring the inorganic chemical reaction is still an extremely difficulty for researchers. This study exactly focused on the monitor of inorganic chemical reaction. Capillary coated with silver nanoparticles was introduced, which was an efficient platform for monitoring reactions with SERS due to the advantages of sensitivity and excellent reproducibility. The photoreduction of [Fe(phen)3](3+) to [Fe(phen)3](2+) was used as model reaction to demonstrated the feasibility of SERS monitoring inorganic chemical reaction by involving in metal-organic complexes. Moreover, the preliminary implementation demonstrated that the kinetics of photoreduction can be real-time monitored by in situ using the SERS technique on a single constructed capillary, which may be useful for the practical application of SERS technique.

  14. Biological inorganic chemistry at the beginning of the 21st century.

    PubMed

    Gray, Harry B

    2003-04-01

    Advances in bioinorganic chemistry since the 1970s have been driven by three factors: rapid determination of high-resolution structures of proteins and other biomolecules, utilization of powerful spectroscopic tools for studies of both structures and dynamics, and the widespread use of macromolecular engineering to create new biologically relevant structures. Today, very large molecules can be manipulated at will, with the result that certain proteins and nucleic acids themselves have become versatile model systems for elucidating biological function.

  15. A hierarchical approach to coding chemical, biological and pharmaceutical substances.

    PubMed

    Keefe, Anya R; Bert, Joel L; Grace, John R; Makaroff, Sylvia J; Lang, Barbara J; Band, Pierre R

    2005-01-01

    This hierarchical coding system is designed to classify substances into successively subordinate categories on the basis of chemical, physical and biological properties. Although initially developed for occupational cancer epidemiological studies, it is general in nature and can be used for other purposes where a systematic approach is needed to catalogue or analyze large numbers of substances and/or physical properties. The coding system incorporates a multi level approach, where substances can be coded both on the basis of function and composition. On the first level, a three digit code is assigned to each substance to indicate its primary use in the occupational environment (e.g. pesticide, catalyst, adhesive). Substances can then be coded using a ten digit code to indicate structure and composition (e.g. organic molecule, biomolecule, pharmaceutical). Depending on the complexity required, analysis can incorporate the three digit code, ten digit code, or a combination of both. The approach to coding both chemical and biological agents is modeled in part after conventional approaches used by the International Union of Pure and Applied Chemists (IUPAC) and the International Union of Biochemists (IUB). Development of the coding system was initiated in the 1980's in response to a need for a system allowing analysis of individual agents as well classes or groups of substances. The project was undertaken as a collaborative venture between the BC Cancer Agency, Cancer Control Research program (then Division of Epidemiology) and the Department of Chemical and Biological Engineering at the University of British Columbia.

  16. Microscale Procedure for Inorganic Qualitative Analysis with Emphasis on Writing Equations: Chemical Fingerprinting Applied to the "n"-bottle Problem of Matching Samples with Their Formulas

    ERIC Educational Resources Information Center

    Sattsangi, Prem D.

    2014-01-01

    A laboratory method for teaching inorganic qualitative analysis and chemical equations is described. The experiment has been designed to focus attention on cations and anions that react to form products. This leads to a logical approach to understand and write chemical equations. The procedure uses 3 mL plastic micropipettes to store and deliver…

  17. Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system.

    PubMed

    Serna-Galvis, Efraím A; Silva-Agredo, Javier; Giraldo-Aguirre, Ana L; Torres-Palma, Ricardo A

    2015-08-15

    Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20-60 W), dissolved gas (air, Ar and He), pH (3-11) and initial concentration of fluoxetine (2.9-162.0 μmol L(-1)). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe(2+)) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment.

  18. On the chemical biology of the nitrite/sulfide interaction.

    PubMed

    Cortese-Krott, Miriam M; Fernandez, Bernadette O; Kelm, Malte; Butler, Anthony R; Feelisch, Martin

    2015-04-30

    Sulfide (H2S/HS(-)) has been demonstrated to exert an astounding breadth of biological effects, some of which resemble those of nitric oxide (NO). While the chemistry, biochemistry and potential pathophysiology of the cross-talk between sulfide and NO have received considerable attention lately, a comparable assessment of the potential biological implications of an interaction between nitrite and sulfide is lacking. This is surprising inasmuch as nitrite is not only a known bioactive oxidation product of NO, but also efficiently converted to S-nitrosothiols in vivo; the latter have been shown to rapidly react with sulfide in vitro, leading to formation of S/N-hybrid species including thionitrite (SNO(-)) and nitrosopersulfide (SSNO(-)). Moreover, nitrite is used as a potent remedy against sulfide poisoning in the clinic. The chemistry of interaction between nitrite and sulfide or related bioactive metabolites including polysulfides and elemental sulfur has been extensively studied in the past, yet much of this information appears to have been forgotten. In this review, we focus on the potential chemical biology of the interaction between nitrite and sulfide or sulfane sulfur molecules, calling attention to the fundamental chemical properties and reactivities of either species and discuss their possible contribution to the biology, pharmacology and toxicology of both nitrite and sulfide.

  19. Biological and environmental hazards associated with exposure to chemical warfare agents: arsenicals.

    PubMed

    Li, Changzhao; Srivastava, Ritesh K; Athar, Mohammad

    2016-08-01

    Arsenicals are highly reactive inorganic and organic derivatives of arsenic. These chemicals are very toxic and produce both acute and chronic tissue damage. On the basis of these observations, and considering the low cost and simple methods of their bulk syntheses, these agents were thought to be appropriate for chemical warfare. Among these, the best-known agent that was synthesized and weaponized during World War I (WWI) is Lewisite. Exposure to Lewisite causes painful inflammatory and blistering responses in the skin, lung, and eye. These chemicals also manifest systemic tissue injury following their cutaneous exposure. Although largely discontinued after WWI, stockpiles are still known to exist in the former Soviet Union, Germany, Italy, the United States, and Asia. Thus, access by terrorists or accidental exposure could be highly dangerous for humans and the environment. This review summarizes studies that describe the biological, pathophysiological, toxicological, and environmental effects of exposure to arsenicals, with a major focus on cutaneous injury. Studies related to the development of novel molecular pathobiology-based antidotes against these agents are also described.

  20. Propolis volatile compounds: chemical diversity and biological activity: a review

    PubMed Central

    2014-01-01

    Propolis is a sticky material collected by bees from plants, and used in the hive as building material and defensive substance. It has been popular as a remedy in Europe since ancient times. Nowadays, propolis use in over-the-counter preparations, “bio”-cosmetics and functional foods, etc., increases. Volatile compounds are found in low concentrations in propolis, but their aroma and significant biological activity make them important for propolis characterisation. Propolis is a plant-derived product: its chemical composition depends on the local flora at the site of collection, thus it offers a significant chemical diversity. The role of propolis volatiles in identification of its plant origin is discussed. The available data about chemical composition of propolis volatiles from different geographic regions are reviewed, demonstrating significant chemical variability. The contribution of volatiles and their constituents to the biological activities of propolis is considered. Future perspectives in research on propolis volatiles are outlined, especially in studying activities other than antimicrobial. PMID:24812573

  1. Biosynthetic inorganic chemistry.

    PubMed

    Lu, Yi

    2006-08-25

    Inorganic chemistry and biology can benefit greatly from each other. Although synthetic and physical inorganic chemistry have been greatly successful in clarifying the role of metal ions in biological systems, the time may now be right to utilize biological systems to advance coordination chemistry. One such example is the use of small, stable, easy-to-make, and well-characterized proteins as ligands to synthesize novel inorganic compounds. This biosynthetic inorganic chemistry is possible thanks to a number of developments in biology. This review summarizes the progress in the synthesis of close models of complex metalloproteins, followed by a description of recent advances in using the approach for making novel compounds that are unprecedented in either inorganic chemistry or biology. The focus is mainly on synthetic "tricks" learned from biology, as well as novel structures and insights obtained. The advantages and disadvantages of this biosynthetic approach are discussed.

  2. Carbon Nanotube Electrode Arrays For Enhanced Chemical and Biological Sensing

    NASA Technical Reports Server (NTRS)

    Han, Jie

    2003-01-01

    Applications of carbon nanotubes for ultra-sensitive electrical sensing of chemical and biological species have been a major focus in NASA Ames Center for Nanotechnology. Great progress has been made toward controlled growth and chemical functionalization of vertically aligned carbon nanotube arrays and integration into micro-fabricated chip devices. Carbon nanotube electrode arrays devices have been used for sub-attomole detection of DNA molecules. Interdigitated carbon nanotubes arrays devices have been applied to sub ppb (part per billion) level chemical sensing for many molecules at room temperature. Stability and reliability have also been addressed in our device development. These results show order of magnitude improvement in device performance, size and power consumption as compared to micro devices, promising applications of carbon nanotube electrode arrays for clinical molecular diagnostics, personal medical testing and monitoring, and environmental monitoring.

  3. Engineered ion channels as emerging tools for chemical biology.

    PubMed

    Mayer, Michael; Yang, Jerry

    2013-12-17

    Over the last 25 years, researchers have developed exogenously expressed, genetically engineered, semi-synthetic, and entirely synthetic ion channels. These structures have sufficient fidelity to serve as unique tools that can reveal information about living organisms. One of the most exciting success stories is optogenetics: the use of light-gated channels to trigger action potentials in specific neurons combined with studies of the response from networks of cells or entire live animals. Despite this breakthrough, the use of molecularly engineered ion channels for studies of biological systems is still in its infancy. Historically, researchers studied ion channels in the context of their own function in single cells or in multicellular signaling and regulation. Only recently have researchers considered ion channels and pore-forming peptides as responsive tools to report on the chemical and physical changes produced by other biochemical processes and reactions. This emerging class of molecular probes has a number of useful characteristics. For instance, these structures can greatly amplify the signal of chemical changes: the binding of one molecule to a ligand-gated ion channel can result in flux of millions of ions across a cell membrane. In addition, gating occurs on sub-microsecond time scales, resulting in fast response times. Moreover, the signal is complementary to existing techniques because the output is ionic current rather than fluorescence or radioactivity. And finally, ion channels are also localized at the membrane of cells where essential processes such as signaling and regulation take place. This Account highlights examples, mostly from our own work, of uses of ion channels and pore-forming peptides such as gramicidin in chemical biology. We discuss various strategies for preparing synthetically tailored ion channels that range from de novo designed synthetic molecules to genetically engineered or simply exogenously expressed or reconstituted wild

  4. Biological stoichiometry: a chemical bridge between ecosystem ecology and evolutionary biology.

    PubMed

    Elser, James

    2006-12-01

    The mission of the American Society of Naturalists is "to advance and diffuse knowledge of organic evolution and other broad biological principles so as to enhance the conceptual unification of the biological sciences." In this article, I argue that the area of biology least integrated with knowledge of organic evolution is the field of ecosystem ecology, as evidenced by a semiquantitative literature survey of use of terms in the scientific literature. I present an overview of recent theoretical developments and empirical findings in the emerging field of biological stoichiometry (the study of the balance of energy and multiple chemical elements in living systems). These developments hold some promise as a means to conceptually integrate ecosystem ecology, with its emphasis on flows and pools of energy and chemical elements, with evolutionary biology, with its emphasis on genetic fitness and the biochemical products of the genome. For example, recent evidence indicates that organismal C : P and N : P ratios have a major impact on biologically mediated flows of energy and phosphorus; in turn, variations among taxa in these ratios are connected to evolved differences in organismal growth rate because of the connection between growth rate and the need for increased allocation to P-rich ribosomal RNA. In this way, evolutionary change in growth-related traits, by altering organismal P requirements, has direct biogeochemical implications, while ecosystem conditions can constrain evolutionary acceleration of growth rates by imposing a direct P limitation on production of the needed biochemical machinery of growth. Thus, stoichiometric theory provides a broad biological principle that can interconvert the currencies and concerns of ecosystem ecology and evolutionary biology, facilitating integration of diverse fields of study and contributing to conceptual unification of the biological sciences.

  5. Autonomous chemical and biological miniature wireless-sensor

    NASA Astrophysics Data System (ADS)

    Goldberg, Bar-Giora

    2005-05-01

    The presentation discusses a new concept and a paradigm shift in biological, chemical and explosive sensor system design and deployment. From large, heavy, centralized and expensive systems to distributed wireless sensor networks utilizing miniature platforms (nodes) that are lightweight, low cost and wirelessly connected. These new systems are possible due to the emergence and convergence of new innovative radio, imaging, networking and sensor technologies. Miniature integrated radio-sensor networks, is a technology whose time has come. These network systems are based on large numbers of distributed low cost and short-range wireless platforms that sense and process their environment and communicate data thru a network to a command center. The recent emergence of chemical and explosive sensor technology based on silicon nanostructures, coupled with the fast evolution of low-cost CMOS imagers, low power DSP engines and integrated radio chips, has created an opportunity to realize the vision of autonomous wireless networks. These threat detection networks will perform sophisticated analysis at the sensor node and convey alarm information up the command chain. Sensor networks of this type are expected to revolutionize the ability to detect and locate biological, chemical, or explosive threats. The ability to distribute large numbers of low-cost sensors over large areas enables these devices to be close to the targeted threats and therefore improve detection efficiencies and enable rapid counter responses. These sensor networks will be used for homeland security, shipping container monitoring, and other applications such as laboratory medical analysis, drug discovery, automotive, environmental and/or in-vivo monitoring. Avaak"s system concept is to image a chromatic biological, chemical and/or explosive sensor utilizing a digital imager, analyze the images and distribute alarm or image data wirelessly through the network. All the imaging, processing and communications

  6. Biological, morphological, and chemical characteristics of Wailuku River, Hawaii

    USGS Publications Warehouse

    Yee, J.J.; Ewart, C.J.

    1986-01-01

    Biological, morphological, and chemical data on Wailuku River were collected to assess its water quality characteristics. Biological measurements included evaluation of benthic invertebrates, periphyton, phytoplankton and coliform bacteria. Morphological measurements consisted of channel surveys and particle size determination of bed materials. Chemical quality measurements, made monthly at two sampling stations, included water temperature, pH, specific conductance, dissolved solids concentration, turbidity, dissolved oxygen, nitrogen, phosphorus , and minor elements. Biological and chemical data indicated relatively clean water compared to similar streams in conterminous United States. The number and types of benthic organisms are low in Wailuku River. This is due mainly to channel gradient and flow velocities rather than to chemical toxicity. Periphyton data also indicate unpolluted water of low to moderate primary productivity. Diatoms are the dominant organisms observed in the periphyton samples. Coliform bacteria densities are typical of mountain streams in Hawaii that are essentially unaffected by human activities. The streambed is formed of lava flows from Mauna Loa volcano, and the stream channel is characterized by a series of plunge pools and waterfalls. The longitudinal slope ranges from 5% at midreaches to 8% at the headwater regions. There is no broad flood plain at the mouth of the stream. The stream channel is generally a narrow steep-sided trapezoid with an irregular base. Streambanks are composed of fine to very coarse-grained material. Channel depth increases from 6 ft at the headwaters to 40 ft at Hilo. The width also increases from 60 ft at the highest study site to 220 ft at the Hilo site near the mouth of the river. (Author 's abstract)

  7. Direct determination of methylmercury and inorganic mercury in biological materials by solid sampling-electrothermal vaporization-inductively coupled plasma-isotope dilution-mass spectrometry.

    PubMed

    Gelaude, I; Dams, R; Resano, M; Vanhaecke, F; Moens, L

    2002-08-01

    This paper reports on the use of solid sampling-electrothermal vaporization-inductively coupled plasma mass spectrometry (SS-EIV-ICPMS) for the direct and simultaneous determination of methylmercury and inorganic mercury in biological materials. The main advantage of this fast and sensitive method is that no sample preparation is required. In this way, the sample throughput can be considerably increased, problems of contamination and analyte losses are kept to a minimum and, even more important, the original chemical form of the different analyte species in the solid samples is preserved. To achieve this goal, a solid sample is inserted into a graphite furnace of the boat-in-tube type and is subsequently submitted to an appropriate temperature program, leading to the separate vaporization of methylmercury and inorganic mercury, which are transported into the ICP by means of an argon carrier gas. The separation was accomplished within 75 s. For the quantification of the two peaks, species-unspecific isotope dilution was used. For this purpose, a stable flow of argon loaded with gaseous Hg isotopically enriched in 200Hg was generated using a permeation tube that was constructed in-house. Its emission rate was determined by collecting the mercury released during a given time interval on a gold-coated silica absorber, after which the amount collected was released by heating of the absorber and determined by cold vapor atomic absorption spectrometry (CVAAS) and cold vapor atomic fluorescence spectrometry (CVAFS). A reference material from the Canadian National Research Council (NRC) (TORT-2) was used to assess the accuracy of the method. For the application of the method to samples with diverse mercury contents, the spike/sample ratio can be optimized by varying the emission rate of the permeation tube simply by adapting its temperature. To prove the feasibility of this approach, two reference materials (BCR 463 and DORM-2) with a methylmercury content more than 10

  8. Free radicals in chemical biology: from chemical behavior to biomarker development.

    PubMed

    Chatgilialoglu, Chryssostomos; Ferreri, Carla; Masi, Annalisa; Melchiorre, Michele; Sansone, Anna; Terzidis, Michael A; Torreggiani, Armida

    2013-04-15

    The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological processes. This subject embraces diverse scientific areas, spanning from physical, biological and bioorganic chemistry to biology and medicine, with applications to the amelioration of quality of life, health and aging. Multidisciplinary skills are required for the full investigation of the many facets of radical processes in the biological environment and chemical knowledge plays a crucial role in unveiling basic processes and mechanisms. We developed a chemical biology approach able to connect free radical chemical reactivity with biological processes, providing information on the mechanistic pathways and products. The core of this approach is the design of biomimetic models to study biomolecule behavior (lipids, nucleic acids and proteins) in aqueous systems, obtaining insights of the reaction pathways as well as building up molecular libraries of the free radical reaction products. This context can be successfully used for biomarker discovery and examples are provided with two classes of compounds: mono-trans isomers of cholesteryl esters, which are synthesized and used as references for detection in human plasma, and purine 5',8-cyclo-2'-deoxyribonucleosides, prepared and used as reference in the protocol for detection of such lesions in DNA samples, after ionizing radiations or obtained from different health conditions.

  9. Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

    PubMed Central

    Chatgilialoglu, Chryssostomos; Ferreri, Carla; Masi, Annalisa; Melchiorre, Michele; Sansone, Anna; Terzidis, Michael A.; Torreggiani, Armida

    2013-01-01

    The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological processes. This subject embraces diverse scientific areas, spanning from physical, biological and bioorganic chemistry to biology and medicine, with applications to the amelioration of quality of life, health and aging. Multidisciplinary skills are required for the full investigation of the many facets of radical processes in the biological environment and chemical knowledge plays a crucial role in unveiling basic processes and mechanisms. We developed a chemical biology approach able to connect free radical chemical reactivity with biological processes, providing information on the mechanistic pathways and products. The core of this approach is the design of biomimetic models to study biomolecule behavior (lipids, nucleic acids and proteins) in aqueous systems, obtaining insights of the reaction pathways as well as building up molecular libraries of the free radical reaction products. This context can be successfully used for biomarker discovery and examples are provided with two classes of compounds: mono-trans isomers of cholesteryl esters, which are synthesized and used as references for detection in human plasma, and purine 5',8-cyclo-2'-deoxyribonucleosides, prepared and used as reference in the protocol for detection of such lesions in DNA samples, after ionizing radiations or obtained from different health conditions. PMID:23629513

  10. FRAMEWORK FOR INORGANIC METALS RISK ASSESSMENT

    EPA Science Inventory

    The EPA has prepared a framework to guide risk assessors in assessing human and ecological risks of inorganic metals. Metals and metal compounds have properties not generally encountered with organic chemicals. For example, metals are neither created nor destroyed by biological a...

  11. Organic and inorganic amendment application on mercury-polluted soils: effects on soil chemical and biochemical properties.

    PubMed

    García-Sánchez, Mercedes; Klouza, Martin; Holečková, Zlata; Tlustoš, Pavel; Száková, Jiřina

    2016-07-01

    On the basis of a previous study performed in our laboratory, the use of organic and inorganic amendments can significantly modify the Hg mobility in soil. We have compared the effectiveness of organic and inorganic amendments such as digestate and fly ash, respectively, reducing the Hg mobility in Chernozem and Luvisol soils differing in their physicochemical properties. Hence, the aim of this work was to compare the impact of digestate and fly ash application on the chemical and biochemical parameters in these two mercury-contaminated soils in a model batch experiment. Chernozem and Luvisol soils were artificially contaminated with Hg and then incubated under controlled conditions for 21 days. Digestate and fly ash were applied to both soils in a dose of 10 and 1.5 %, respectively, and soil samples were collected after 1, 7, 14, and 21 days of incubation. The presence of Hg in both soils negatively affected to processes such as nitrification, provoked a decline in the soil microbial biomass C (soil microbial biomass C (MBC)), and the microbial activities (arylsulfatase, and β-glucosaminidase) in both soils. Meanwhile, the digestate addition to Chernozem and Luvisol soils contaminated with Hg improved the soil chemical properties (pH, dissolved organic carbon (DOC), N (Ntot), inorganic-N forms (N-NH4 (+) and N-NO3 (-))), as consequence of high content in C and N contained in digestate. Likewise, the soil MBC and soil microbial activities (dehydrogenase, arylsulfatase, and β-glucosaminidase) were greatly enhanced by the digestate application in both soils. In contrast, fly ash application did not have a remarkable positive effect when compared to digestate in Chernozem and Luvisol soil contaminated with mercury. These results may indicate that the use of organic amendments such as digestate considerably improved the soil health in Chernozem and Luvisol compared with fly ash, alleviating the detrimental impact of Hg. Probably, the chemical properties present in

  12. Chemical and genetic tools to explore S1P biology.

    PubMed

    Cahalan, Stuart M

    2014-01-01

    The zwitterionic lysophospholipid Sphingosine 1-Phosphate (S1P) is a pleiotropic mediator of physiology and pathology. The synthesis, transport, and degradation of S1P are tightly regulated to ensure that S1P is present in the proper concentrations in the proper location. The binding of S1P to five G protein-coupled S1P receptors regulates many physiological systems, particularly the immune and vascular systems. Our understanding of the functions of S1P has been aided by the tractability of the system to both chemical and genetic manipulation. Chemical modulators have been generated to affect most of the known components of S1P biology, including agonists of S1P receptors and inhibitors of enzymes regulating S1P production and degradation. Genetic knockouts and manipulations have been similarly engineered to disrupt the functions of individual S1P receptors or enzymes involved in S1P metabolism. This chapter will focus on the development and utilization of these chemical and genetic tools to explore the complex biology surrounding S1P and its receptors, with particular attention paid to the in vivo findings that these tools have allowed for.

  13. The chemical composition of inorganic and carbonaceous materials in PM 2.5 in Nanjing, China

    NASA Astrophysics Data System (ADS)

    Yang, Hong; Yu, Jian Zhen; Ho, Steven Sai Hang; Xu, Jinhui; Wu, Wai-Shing; Wan, Chun Hong; Wang, Xiaodong; Wang, Xiaorong; Wang, Liansheng

    PM 2.5 samples were collected at an urban and a suburban site in Nanjing, China in 2001. They were analyzed for inorganic ions, elemental carbon, organic carbon (OC), water-soluble organic carbon (WSOC), and individual WSOC and nonpolar organic species. Sulfate and organic matter were the two most abundant constituents in these samples. Sulfate accounted for an average of 23% (urban site) and 30% (suburban site) of the identified aerosol mass. Organic matter accounted for an average of 37% (urban) and 28% (suburban) of the identified aerosol mass. WSOC was a significant portion of OC, accounting for about one-third of OC at the urban site and 45% of OC at the suburban site. The suburban-urban gradient in the WSOC/OC ratio also reflected that the aerosol OC was more aged at the suburban location. The correlations of WSOC with sulfate and nitrate suggest that the WSOC fraction was dominated by secondary organics. More than 30 individual WSOC species in the compound classes of organic anions, amino acids, aliphatic amines, and carbohydrates were quantified, accounting for approximately 8% of the WSOC on a carbon mass basis. In addition, 46 individual nonpolar organic compounds in the compound classes of n-alkanes, hopanes, and polycyclic aromatic hydrocarbons were quantified using an in-injection port thermal desorption technique. These nonpolar organic species accounted for less than 7% of the OC on a carbon mass basis. The quantification of individual compounds allowed the identification of major aerosol sources through principal component analysis. Coal combustion, vehicular emissions, secondary inorganic and organic aerosols, and road/sea salt were the major contributing sources to the identified PM 2.5 aerosol mass.

  14. Chemical Imaging of Biological Tissue with Synchrotron Infrared Light

    SciTech Connect

    Miller,L.; Dumas, P.

    2006-01-01

    Fourier transform infrared micro-spectroscopy (FTIRM) and imaging (FTIRI) have become valuable techniques for examining the chemical makeup of biological materials by probing their vibrational motions on a microscopic scale. Synchrotron infrared (S-IR) light is an ideal source for FTIRM and FTIRI due to the combination of its high brightness (i.e., flux density), also called brilliance, and broadband nature. Through a 10-{mu}m pinhole, the brightness of a synchrotron source is 100-1000 times higher than a conventional thermal (globar) source. Accordingly, the improvement in spatial resolution and in spectral quality to the diffraction limit has led to a plethora of applications that is just being realized. In this review, we describe the development of synchrotron-based FTIRM, illustrate its advantages in many applications to biological systems, and propose some potential future directions for the technique.

  15. Current Chemical Biology Approaches to Interrogate Protein Methyltransferases

    PubMed Central

    Luo, Minkui

    2012-01-01

    Protein methyltransferases (PMTs) play various physiological and pathological roles through methylating histone and nonhistone targets. However, most PMTs including more than 60 human PMTs remain to be fully characterized. The current approaches to elucidate the functions of PMTs have been diversified by many emerging chemical biology technologies. This review focuses on progress in these aspects and is organized into four discussion modules (assays, substrates, cofactors and inhibitors) that are important to elucidate biological functions of PMTs. These modules are expected to provide general guidance and present emerging methods for researchers to select and combine suitable PMT-activity assays, well-defined substrates, novel SAM surrogates and PMT inhibitors to interrogate PMTs. PMID:22220966

  16. Physical, chemical, and biological properties of wonder kelp--Laminaria.

    PubMed

    Kim, Se-Kwon; Bhatnagar, Ira

    2011-01-01

    Laminaria is a kelp that finds its place in the brown algae family. It has been an area of study for past many years, and its wonderful biological properties have always attracted medical professionals and researchers to explore more and more from this wonder kelp. The constituents of Laminaria include iodine, potassium, magnesium, calcium and iron. Iodine compounds, TEA-hydroiodide in particular, are great lipolytic agents as they stimulate lipase activity. Laminarins on the other hand are used as a tumor angiogenic blocker. This genus of the kelps is also rich in algin, a high molecular weight polysaccharide that forms viscous colloidal solutions or gels in water leading to the use of kelp derivatives as bulk laxatives. It has great applications in cosmeceutical science, as well as some antibacterial properties have also been assigned to Laminaria. A deeper insight into the physical, biological, and chemical properties of this wonder kelp would lead to further exploitation of Laminaria for medicinal and cosmeceutical purpose.

  17. Terrorism: Background on Chemical, Biological, and Toxin Weapons and Options for Lessening Their Impact

    DTIC Science & Technology

    2003-06-30

    CRS-4 13(...continued) National Center for Environmental Health , Centers for Disease Control and Prevention, Emergency Room Procedures in Chemical...Chemical, biological, and toxin weapons pose additional concerns beyond mass casualties. Chemical, biological, and toxin weapons may contaminate the area...biological, and toxin weapons. One approach has been through funding significant increases in the public health system’s preparedness and response

  18. Biological and chemical technologies research. FY 1995 annual summary report

    SciTech Connect

    1996-03-01

    The annual summary report presents the fiscal year (FY) 1995 research activities and accomplishments for the United States Department of Energy (DOE) Biological and Chemical Technologies Research (BCTR) Program. This BCTR program resides within the Office of Industrial Technologies (OIT) of the Office of Energy Efficiency and Renewable Energy (EE). The annual summary report for 1995 (ASR 95) contains the following: program description (including BCTR program mission statement, historical background, relevance, goals and objectives); program structure and organization, selected technical and programmatic highlights for 1995; detailed descriptions of individual projects; a listing of program output, including a bibliography of published work; patents; and awards arising from work supported by the BCTR.

  19. Smart phones: platform enabling modular, chemical, biological, and explosives sensing

    NASA Astrophysics Data System (ADS)

    Finch, Amethist S.; Coppock, Matthew; Bickford, Justin R.; Conn, Marvin A.; Proctor, Thomas J.; Stratis-Cullum, Dimitra N.

    2013-05-01

    Reliable, robust, and portable technologies are needed for the rapid identification and detection of chemical, biological, and explosive (CBE) materials. A key to addressing the persistent threat to U.S. troops in the current war on terror is the rapid detection and identification of the precursor materials used in development of improvised explosive devices, homemade explosives, and bio-warfare agents. However, a universal methodology for detection and prevention of CBE materials in the use of these devices has proven difficult. Herein, we discuss our efforts towards the development of a modular, robust, inexpensive, pervasive, archival, and compact platform (android based smart phone) enabling the rapid detection of these materials.

  20. Bayesian methods in virtual screening and chemical biology.

    PubMed

    Bender, Andreas

    2011-01-01

    The Naïve Bayesian Classifier, as well as related classification and regression approaches based on Bayes' theorem, has experienced increased attention in the cheminformatics world in recent years. In this contribution, we first review the mathematical framework on which Bayes' methods are built, and then continue to discuss implications of this framework as well as practical experience under which conditions Bayes' methods give the best performance in virtual screening settings. Finally, we present an overview of applications of Bayes' methods to both virtual screening and the chemical biology arena, where applications range from bridging phenotypic and mechanistic space of drug action to the prediction of ligand-target interactions.

  1. Surfactant-Based Chemical and Biological Agent Decontaminating Solution Development

    DTIC Science & Technology

    2003-11-19

    10^8 4 PAA in uEm 10^8 8 (1) C10 Amine oxide (2) di-C10 Amine oxide ! Peracetic Acid (PAA) Found to Be an Effective Disinfectant Decon Conf 11-03...Utilize as Environmentally Green Reactant for Both Chemical and Biological Agents – Some Peracids Available in Neat Form ( Peracetic acid ) and In-Situ...Formulation Components – Peroxygen Compounds and Catalysts Oxidation of Calmagite Dye by Peracetic Acid TAML FeMB Catalyst 0 20 40 60 80 100 120 0 2 4 6

  2. Chemical and biological treatment technologies for leather tannery chemicals and wastewaters: a review.

    PubMed

    Lofrano, Giusy; Meriç, Sureyya; Zengin, Gülsüm Emel; Orhon, Derin

    2013-09-01

    Although the leather tanning industry is known to be one of the leading economic sectors in many countries, there has been an increasing environmental concern regarding the release of various recalcitrant pollutants in tannery wastewater. It has been shown that biological processes are presently known as the most environmental friendly but inefficient for removal of recalcitrant organics and micro-pollutants in tannery wastewater. Hence emerging technologies such as advanced oxidation processes and membrane processes have been attempted as integrative to biological treatment for this sense. This paper, as the-state-of-the-art, attempts to revise the over world trends of treatment technologies and advances for pollution prevention from tannery chemicals and wastewater. It can be elucidated that according to less extent advances in wastewater minimization as well as in leather production technology and chemicals substitution, biological and chemical treatment processes have been progressively studied. However, there has not been a full scale application yet of those emerging technologies using advanced oxidation although some of them proved good achievements to remove xenobiotics present in tannery wastewater. It can be noted that advanced oxidation technologies integrated with biological processes will remain in the agenda of the decision makers and water sector to apply the best prevention solution for the future tanneries.

  3. Molecular codes in biological and chemical reaction networks.

    PubMed

    Görlich, Dennis; Dittrich, Peter

    2013-01-01

    Shannon's theory of communication has been very successfully applied for the analysis of biological information. However, the theory neglects semantic and pragmatic aspects and thus cannot directly be applied to distinguish between (bio-) chemical systems able to process "meaningful" information from those that do not. Here, we present a formal method to assess a system's semantic capacity by analyzing a reaction network's capability to implement molecular codes. We analyzed models of chemical systems (martian atmosphere chemistry and various combustion chemistries), biochemical systems (gene expression, gene translation, and phosphorylation signaling cascades), an artificial chemistry, and random reaction networks. Our study suggests that different chemical systems possess different semantic capacities. No semantic capacity was found in the model of the martian atmosphere chemistry, the studied combustion chemistries, and highly connected random networks, i.e. with these chemistries molecular codes cannot be implemented. High semantic capacity was found in the studied biochemical systems and in random reaction networks where the number of second order reactions is twice the number of species. We conclude that our approach can be applied to evaluate the information processing capabilities of a chemical system and may thus be a useful tool to understand the origin and evolution of meaningful information, e.g. in the context of the origin of life.

  4. Biological monitoring IX: Concomitant exposure to medications and industrial chemicals

    SciTech Connect

    Rosenberg, J.

    1994-05-01

    A significant proportion of workers may be receiving prescription or nonprescription medications. In two surveys, one in the United States and the other in the Netherlands, 15 to 30 percent of workers reported current use of pharmaceuticals. In a viscose rayon factory in Belgium, 31 percent of 129 workers exposed to carbon disulfide and 19.8 percent of 81 control workers from other factories reported use of some medication. Some of the drugs may affect the relationship between the external exposure (dose) of a chemical and the concentration of that chemical or its metabolite(s) in a sampled biological medium (internal dose), and/or the relationship between external exposure and concentration at a receptor site. They may also modulate the response of the receptor, as suggested by the increased reports of neurological symptoms in carbon disulfide-exposed workers taking certain medications. There are two obvious differences between drugs and industrial chemicals: (1) The effects of drugs cover a wider spectrum and include effects not known to be the result of any industrial chemicals. Examples include selective destructive inhibition of hepatic enzymes (monoamine oxidase inhibitors, indomethacin) and alteration of hepatic blood flow (adrenergic agents, cimetidine). (2) Drugs are administered to produce specific therapeutic effects. 18 refs., 1 tab.

  5. Insect-gene-activity detection system for chemical and biological warfare agents and toxic industrial chemicals

    NASA Astrophysics Data System (ADS)

    Mackie, Ryan S.; Schilling, Amanda S.; Lopez, Arturo M.; Rayms-Keller, Alfredo

    2002-02-01

    Detection of multiple chemical and biological weapons (CBW) agents and/or complex mixtures of toxic industrial chemicals (TIC) is imperative for both the commercial and military sectors. In a military scenario, a multi-CBW attack would create confusion, thereby delaying decontamination and therapeutic efforts. In the commercial sector, polluted sites invariably contain a mixture of TIC. Novel detection systems capable of detecting CBW and TIC are sorely needed. While it may be impossible to build a detector capable of discriminating all the possible combinations of CBW, a detection system capable of statistically predicting the most likely composition of a given mixture is within the reach of current emerging technologies. Aquatic insect-gene activity may prove to be a sensitive, discriminating, and elegant paradigm for the detection of CBW and TIC. We propose to systematically establish the expression patterns of selected protein markers in insects exposed to specific mixtures of chemical and biological warfare agents to generate a library of biosignatures of exposure. The predicting capabilities of an operational library of biosignatures of exposures will allow the detection of emerging novel or genetically engineered agents, as well as complex mixtures of chemical and biological weapons agents. CBW and TIC are discussed in the context of war, terrorism, and pollution.

  6. Preparation, characterization, and biological properties of organic-inorganic nanocomposite coatings on titanium substrates prepared by sol-gel.

    PubMed

    Catauro, Michelina; Bollino, Flavia; Papale, Ferdinando

    2014-02-01

    When surface-reactive (bioactive) coatings are applied to medical implants by means of the sol-gel dip-coating technique, the biological proprieties of the surface of the implant can be locally modified to match the properties of the surrounding tissues to provide a firm fixation of the implant. The aim of this study has been to synthesize, via sol-gel, organoinorganic nanoporous materials and to dip-coat a substrate to use in dental applications. Different systems have been prepared consisting of an inorganic zirconium-based matrix, in which a biodegradable polymer, the poly-ε-caprolactone was incorporated in different percentages. The materials synthesized by the sol-gel process, before gelation, when they were still in sol phase, have been used to coat a titanium grade 4 (Ti-4) substrate to change its surface biological properties. Thin films have been obtained by means of the dip-coating technique. A microstructural analysis of the obtained coatings was performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy. The biological proprieties have been investigated by means of tests in vitro. The bone-bonding capability of the nanocomposite films has been evaluated by examining the appearance of apatite on their surface when plunged in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. The examination of apatite formation on the nanocomposites, after immersion in SBF, has been carried out by SEM equipped with energy-dispersive X-ray spectroscopy. To evaluate cells-materials interaction, human osteosarcoma cell line (Saos-2) has been seeded on specimens and cell vitality evaluated by WST-8 assay.

  7. Methods of information geometry in computational system biology (consistency between chemical and biological evolution).

    PubMed

    Astakhov, Vadim

    2009-01-01

    Interest in simulation of large-scale metabolic networks, species development, and genesis of various diseases requires new simulation techniques to accommodate the high complexity of realistic biological networks. Information geometry and topological formalisms are proposed to analyze information processes. We analyze the complexity of large-scale biological networks as well as transition of the system functionality due to modification in the system architecture, system environment, and system components. The dynamic core model is developed. The term dynamic core is used to define a set of causally related network functions. Delocalization of dynamic core model provides a mathematical formalism to analyze migration of specific functions in biosystems which undergo structure transition induced by the environment. The term delocalization is used to describe these processes of migration. We constructed a holographic model with self-poetic dynamic cores which preserves functional properties under those transitions. Topological constraints such as Ricci flow and Pfaff dimension were found for statistical manifolds which represent biological networks. These constraints can provide insight on processes of degeneration and recovery which take place in large-scale networks. We would like to suggest that therapies which are able to effectively implement estimated constraints, will successfully adjust biological systems and recover altered functionality. Also, we mathematically formulate the hypothesis that there is a direct consistency between biological and chemical evolution. Any set of causal relations within a biological network has its dual reimplementation in the chemistry of the system environment.

  8. Process of inorganic nitrogen transformation and design of kinetics model in the biological aerated filter reactor.

    PubMed

    Yan, Gang; Xu, Xia; Yao, Lirong; Lu, Liqiao; Zhao, Tingting; Zhang, Wenyi

    2011-04-01

    As one of the plug-flow reactors, biological aerated filter (BAF) reactor was divided into four sampling sectors to understand the characteristics of elemental nitrogen transformation during the reaction process, and then the different characteristics of elemental nitrogen transformation caused by different NH(3)-N loadings, biological quantities and activities in each section were obtained. The results showed that the total transformation ratio in the nitrifying reactor was more than 90% in the absence of any organic carbon resource, at the same time, more than 65% NH(3)-N in the influent were nitrified at the filter height of 70 cm below under the conditions of the influent runoff 9-19 L/h, the gas-water ratio 4-5:1, the dissolved oxygen 3.0-5.8 mg/L and the NH(3)-N load 0.28-0.48 kg NH(3)-N/m(3) d. On the base of the Eckenfelder mode, the kinetics equation of the NH(3)-N transformation along the reactor was S(e)=S(0) exp(-0.0134D/L(1.2612)).

  9. Electrophoretic separation techniques and their hyphenation to mass spectrometry in biological inorganic chemistry.

    PubMed

    Holtkamp, Hannah; Grabmann, Gerlinde; Hartinger, Christian G

    2016-04-01

    Electrophoretic methods have been widely applied in research on the roles of metal complexes in biological systems. In particular, CE, often hyphenated to a sensitive MS detector, has provided valuable information on the modes of action of metal-based pharmaceuticals, and more recently new methods have been added to the electrophoretic toolbox. The range of applications continues to expand as a result of enhanced CE-to-MS interfacing, with sensitivity often at picomolar level, and evolved separation modes allowing for innovative sample analysis. This article is a followup to previous reviews about CE methods in metallodrug research (Electrophoresis, 2003, 24, 2023-2037; Electrophoresis, 2007, 28, 3436-3446; Electrophoresis, 2012, 33, 622-634), also providing a comprehensive overview of metal species studied by electrophoretic methods hyphenated to MS. It highlights the latest CE developments, takes a sneak peek into gel electrophoresis, traces biomolecule labeling, and focuses on the importance of early-stage drug development.

  10. University of Texas countermeasures to biological and chemical threats program

    NASA Astrophysics Data System (ADS)

    Kornguth, Steve E.

    2002-07-01

    Developments in the continental US and the international scene have alerted the defense community to the threat of biological and chemical agents on civilian and military populations. The objective of the program will lead to the protection of US and allied forces from biological/chemical threats. The following focus areas are being developed and integrated in our program: (1) scientific validation; (2) medical countermeasures; and (3) communication and integrated conversion of data to knowledge. We are developing binder elements for the sensors and platforms for these sensor systems. To rapidly determine whether individuals have been exposed to threat agents, archival data sets have been established through a partnership with the Texas Department of Health. Large scale, real-time symptomatic diagnoses of patients from emergency medical facilities are being electronically collected and sent to an archival data facility for identification of emergent disease. The ability to diagnose emergent disease can be reduced to twenty-four hours from the week to several weeks currently required.

  11. Potential for portal detection of human chemical and biological contamination

    NASA Astrophysics Data System (ADS)

    Settles, Gary S.; McGann, William J.

    2001-08-01

    The walk-through metal-detection portal is a paradigm of non-intrusive passenger screening in aviation security. Modern explosive detection portals based on this paradigm will soon appear in airports. This paper suggests that the airborne trace detection technology developed for that purpose can also be adapted to human chemical and biological contamination. The waste heat of the human body produces a rising warm-air sheath of 50-80 liters/sec known as the human thermal plume. Contained within this plume are hundreds of bioeffluents from perspiration and breath, and millions of skin flakes. Since early medicine, the airborne human scent was used in the diagnosis of disease. Recent examples also include toxicity and substance abuse, but this approach has never been quantified. The appearance of new bioeffluents or subtle changes in the steady-state may signal the onset of a chemical/biological attack. Portal sampling of the human thermal plume is suggested, followed by a pre-concentration step and the detection of the attacking agent or the early human response. The ability to detect nanogram levels of explosive trace contamination this way was already demonstrated. Key advantages of the portal approach are its rapidity and non-intrusiveness, and the advantage that it does not require the traditional bodily fluid or tissue sampling.

  12. Chemical Biology Applied to the Study of Bacterial Pathogens

    PubMed Central

    Anthouard, Rebecca

    2014-01-01

    In recent years, chemical biology and chemical genomics have been increasingly applied to the field of microbiology to uncover new potential therapeutics as well as to probe virulence mechanisms in pathogens. The approach offers some clear advantages, as identified compounds (i) can serve as a proof of principle for the applicability of drugs to specific targets; (ii) can serve as conditional effectors to explore the function of their targets in vitro and in vivo; (iii) can be used to modulate gene expression in otherwise genetically intractable organisms; and (iv) can be tailored to a narrow or broad range of bacteria. This review highlights recent examples from the literature to illustrate how the use of small molecules has advanced discovery of novel potential treatments and has been applied to explore biological mechanisms underlying pathogenicity. We also use these examples to discuss practical considerations that are key to establishing a screening or discovery program. Finally, we discuss the advantages and challenges of different approaches and the methods that are emerging to address these challenges. PMID:25404026

  13. Remote Raman Efficiencies and Cross-Sections of Organic and Inorganic Chemicals.

    PubMed

    Acosta-Maeda, Tayro E; Misra, Anupam K; Porter, John N; Bates, David E; Sharma, Shiv K

    2016-09-19

    We determined Raman cross-sections of various organic liquids and inorganic polyatomic ions in aqueous solutions with a 532 nm pulsed laser using remote Raman systems developed at the University of Hawaii. Using a calibrated integrating sphere as a light source, we converted the intensity counts in the spectrum of the light from the integrating sphere measured with UH remote Raman instrument to spectral radiance. From these data, a response function of the remote Raman instrument was obtained. With the intensity-calibrated instrument, we collected remote Raman data from a standard 1 mm path length fused silica spectrophotometer cell filled with cyclohexane. The measured value of the differential Raman cross-section for the 801 cm(-1) vibrational mode of cyclohexane is 4.55 × 10(-30) cm(2) sr(-1) molecule(-1) when excited by a 532 nm laser, in good agreement with the values reported in the literature. Using the measured cyclohexane Raman cross-section as a reference and relative Raman mode intensities of the various ions and organic liquids, we calculated the Raman cross-sections of the strongest Raman lines of nitrate, sulfate, carbonate, phosphate ions, and organic liquids by maintaining same experimental conditions for remote Raman detection. These relative Raman cross-section values will be useful for estimating detection capabilities of remote Raman systems for planetary exploration.

  14. [Chemical, physical and biological risks in law enforcement].

    PubMed

    Magrini, Andrea; Grana, Mario; Vicentini, Laura

    2014-01-01

    Chemical, physical and biological risks among public safety and security forces. Law enforcement personnel, involved in routine tasks and in emergency situations, are exposed to numerous and several occupational hazards (chemical, physical and biological) whith likely health and security consequences. These risks are particularly high when the organization and preparation are inadequate, there is a lacking or insufficient coordination, information, education and communication and safety and personal protective equipment are inadequate or insufficient. Despite the objective difficulties, caused by the actual special needs related to the service performed or the organizational peculiarities, the risk identification and assessment is essential for worker health and safety of personnel, as provided for by Legislative Decree no. 81/2008. Chemical risks include airborne pollutants due to vehicular traffic (carbon monoxide, ultrafine particles, benzene, polycyclic aromatic hydrocarbons, aldehydes, nitrogen and sulfur oxides, lead), toxic gases generated by combustion process following fires (aromatic hydrocarbons, PAHs, dioxins and furans, biphenyls, formaldehyde, metals and cyanides), substances emitted in case of chemical accidents (solvents, pesticides, toxic gases, caustics), drugs (methylamphetamine), riot control agents and self-defence spray, lead at firing ranges, and several materials and reagents used in forensic laboratory. The physical hazards are often caused by activities that induce biomechanical overload aid the onset of musculoskeletal disorders, the use of visual display terminals and work environments that may expose to heat stress and discomfort, high and low pressure, noise, vibrations, ionizing and non-ionizing radiation. The main biological risks are blood-borne diseases (viral hepatitis, AIDS), airborne diseases (eg, tuberculosis, meningitis, SARS, anthrax), MRSA, and vector-borne diseases. Many of these risk factors are unavoidable or are not

  15. How chemistry supports cell biology: the chemical toolbox at your service.

    PubMed

    Wijdeven, Ruud H; Neefjes, Jacques; Ovaa, Huib

    2014-12-01

    Chemical biology is a young and rapidly developing scientific field. In this field, chemistry is inspired by biology to create various tools to monitor and modulate biochemical and cell biological processes. Chemical contributions such as small-molecule inhibitors and activity-based probes (ABPs) can provide new and unique insights into previously unexplored cellular processes. This review provides an overview of recent breakthroughs in chemical biology that are likely to have a significant impact on cell biology. We also discuss the application of several chemical tools in cell biology research.

  16. The diverse biological properties of the chemically inert noble gases.

    PubMed

    Winkler, David A; Thornton, Aaron; Farjot, Géraldine; Katz, Ira

    2016-04-01

    The noble gases represent an intriguing scientific paradox. They are extremely inert chemically but display a remarkable spectrum of clinically useful biological properties. Despite a relative paucity of knowledge of their mechanisms of action, some of the noble gases have been used successfully in the clinic. Studies with xenon have suggested that the noble gases as a class may exhibit valuable biological properties such as anaesthesia; amelioration of ischemic damage; tissue protection prior to transplantation; analgesic properties; and a potentially wide range of other clinically useful effects. Xenon has been shown to be safe in humans, and has useful pharmacokinetic properties such as rapid onset, fast wash out etc. The main limitations in wider use are that: many of the fundamental biochemical studies are still lacking; the lighter noble gases are likely to manifest their properties only under hyperbaric conditions, impractical in surgery; and administration of xenon using convectional gaseous anaesthesia equipment is inefficient, making its use very expensive. There is nonetheless a significant body of published literature on the biochemical, pharmacological, and clinical properties of noble gases but no comprehensive reviews exist that summarize their properties and the existing knowledge of their models of action at the molecular (atomic) level. This review provides such an up-to-date summary of the extensive, useful biological properties of noble gases as drugs and prospects for wider application of these atoms.

  17. Biological conversion of gaseous alkenes to liquid chemicals.

    PubMed

    Desai, Shuchi H; Koryakina, Irina; Case, Anna E; Toney, Michael D; Atsumi, Shota

    2016-11-01

    Industrial gas-to-liquid (GTL) technologies are well developed. They generally employ syngas, require complex infrastructure, and need high capital investment to be economically viable. Alternatively, biological conversion has the potential to be more efficient, and easily deployed to remote areas on relatively small scales for the utilization of otherwise stranded resources. The present study demonstrates a novel biological GTL process in which engineered Escherichia coli converts C2-C4 gaseous alkenes into liquid diols. Diols are versatile industrially important chemicals, used routinely as antifreeze agents, polymer precursors amongst many other applications. Heterologous co-expression of a monooxygenase and an epoxide hydrolase in E. coli allows whole cell conversion of C2-C4 alkenes for the formation of ethylene glycol, 1,2-propanediol, 1,2-butanediol, and 2,3-butanediol at ambient temperature and pressure in one pot. Increasing intracellular NADH supply via addition of formate and a formate dehydrogenase increases ethylene glycol production titers, resulting in an improved productivity of 9mg/L/h and a final titer of 250mg/L. This represents a novel biological method for GTL conversion of alkenes to industrially valuable diols.

  18. The chemical biology of naphthoquinones and its environmental implications.

    PubMed

    Kumagai, Yoshito; Shinkai, Yasuhiro; Miura, Takashi; Cho, Arthur K

    2012-01-01

    Quinones are a group of highly reactive organic chemical species that interact with biological systems to promote inflammatory, anti-inflammatory, and anticancer actions and to induce toxicities. This review describes the chemistry, biochemistry, and cellular effects of 1,2- and 1,4-naphthoquinones and their derivatives. The naphthoquinones are of particular interest because of their prevalence as natural products and as environmental chemicals, present in the atmosphere as products of fuel and tobacco combustion. 1,2- and 1,4-naphthoquinones are also toxic metabolites of naphthalene, the major polynuclear aromatic hydrocarbon present in ambient air. Quinones exert their actions through two reactions: as prooxidants, reducing oxygen to reactive oxygen species; and as electrophiles, forming covalent bonds with tissue nucleophiles. The targets for these reactions include regulatory proteins such as protein tyrosine phosphatases; Kelch-like ECH-associated protein 1, the regulatory protein for NF-E2-related factor 2; and the glycolysis enzyme glyceraldehyde-3-phosphate dehydrogenase. Through their actions on regulatory proteins, quinones affect various cell signaling pathways that promote and protect against inflammatory responses and cell damage. These actions vary with the specific quinone and its concentration. Effects of exposure to naphthoquinones as environmental chemicals can vary with the physical state, i.e., whether the quinone is particle bound or is in the vapor state. The exacerbation of pulmonary diseases by air pollutants can, in part, be attributed to quinone action.

  19. Chemical, Biological, and Explosive Sensors for Field Measurements

    SciTech Connect

    Kevin Kyle, Manuel Manard, Stephan Weeks

    2009-01-31

    Special Technologies Laboratory (STL) is developing handheld chemical, biological, and explosive (CBE) detection systems and sensor motes for wireless networked field operations. The CBE sensors are capable of detecting and identifying multiple targeted toxic industrial chemicals (TICs) and high-explosive vapor components. The CBE devices are based on differential mobility spectrometry (DMS) coupled with fast gas chromatography (GC) or mass spectrometry. The systems all include the concepts of: 1. Direct air/particulate “smart” sampling 2. Selective, continuous real-time (~1 sec) alert monitoring using DMS 3. Highly selective, rapid dual technology separation/verification analysis The biosensor technology is based on Raman aerosol particle flow cytometry for target detection and identification. Monitoring and identifying trace level chemical vapors directly from ambient air will allow First Responders to quickly adapt situational response strategies and personal protective equipment needs to the specific response scenario being encountered. First Responders require great confidence in the measurements and ability of a given system to detect CBE below threshold levels without interferences. The concept of determining the background matrix in near real-time to allow subsequent automated field-programmable method selection and cueing of high-value assets in a wide range of environs will be presented. This provides CBE information for decisions prior to First Responders entering the response site or sending a portable mobile unit for a remote site survey of the hazards. The focus is on real-time information needed by those responsible for emergency response and national security.

  20. Cobalt complexes as internal standards for capillary zone electrophoresis-mass spectrometry studies in biological inorganic chemistry.

    PubMed

    Holtkamp, Hannah U; Morrow, Stuart J; Kubanik, Mario; Hartinger, Christian G

    2017-01-02

    Run-by-run variations are very common in capillary electrophoretic (CE) separations and cause imprecision in both the migration times and the peak areas. This makes peak and kinetic trend identification difficult and error prone. With the aim to identify suitable standards for CE separations which are compatible with the common detectors UV, ESI-MS, and ICP-MS, the Co(III) complexes [Co(en)3]Cl3, [Co(acac)3] and K[Co(EDTA)] were evaluated as internal standards in the reaction of the anticancer drug cisplatin and guanosine 5'-monophosphate as an example of a classical biological inorganic chemistry experiment. These Co(III) chelate complexes were considered for their stability, accessibility, and the low detection limit for Co in ICP-MS. Furthermore, the Co(III) complexes are positively and negatively charged as well as neutral, allowing the detection in different areas of the electropherograms. The background electrolytes were chosen to cover a wide pH range. The compatibility to the separation conditions was dependent on the ligands attached to the Co(III) centers, with only the acetylacetonato (acac) complex being applicable in the pH range 2.8-9.0. Furthermore, because of being charge neutral, this compound could be used as an electroosmotic flow (EOF) marker. In general, employing Co complexes resulted in improved data sets, particularly with regard to the migration times and peak areas, which resulted, for example, in higher linear ranges for the quantification of cisplatin.

  1. Inorganic chemical analyses of black shale from wells in the National Petroleum Reserve in Alaska

    SciTech Connect

    Brosge, W.P.; Tailleur, I.L.

    1989-01-01

    Core samples of Mississippian through Upper Cretaceous black shale, siltstone, and limy mudstone from 24 test wells in the National Petroleum Reserve in Alaska (NPRA) have been analyzed for trace elements in order to provide data on regional background concentrations for inorganic geochemical exploration. This study was made because the authors had noticed that several of the rock units cored in the subsurface were associated with surface geochemical anomalies or small mineral deposits in the areas where they crop out. In the southwestern part of the NPRA, the heavy-mineral concentrates from sediments of streams that flow over shale and graywacke of the Lower Cretaceous Fortress Mountain and Torok Formations are unusually rich in lead, arsenic, and silver. Southeast of the NPRA, in the foothills of the Philip Smith Mountains, stream sediments in areas of Permian to Lower Cretaceous shale locally contain anomalously large amounts of zinc and thorium. In addition, the high organic-carbon content of the Shublick Formation, Jurassic (part) Kingak Shale, and lowest Cretaceous pebble shale unit in the subsurface in the Prudhoe Bay area indicate that they may be rich in trace metals. Outcrops of the Shublik in the Brooks Range locally contain much copper, molybdenum, vanadium, and rare-earth elements, and the high gamma-radiation characteristic of the pebble shale unit in the subsurface shows that it is rich in uranium and thorium. The shale section with the most important known metallic deposits is the Mississippian shale and chert now assigned to the Kuna Formation. The distribution of vanadium and nickel may also be of interest in oil exploration. Hughes and others found higher V/Ni ratios in the Prudhoe-Barrow types of oil than in the Umiat-Simpson types and attributed these higher ratios to sources in the Shublik Formation and Jurassic (part) Kingak Shale.

  2. The Biological and Chemical Oceanography Data Management Office

    NASA Astrophysics Data System (ADS)

    Allison, M. D.; Chandler, C. L.; Groman, R. C.; Wiebe, P. H.; Glover, D. M.; Gegg, S. R.

    2011-12-01

    Oceanography and marine ecosystem research are inherently interdisciplinary fields of study that generate and require access to a wide variety of measurements. In late 2006 the Biological and Chemical Oceanography Sections of the National Science Foundation (NSF) Geosciences Directorate Division of Ocean Sciences (OCE) funded the Biological and Chemical Oceanography Data Management Office (BCO-DMO). In late 2010 additional funding was contributed to support management of research data from the NSF Office of Polar Programs Antarctic Organisms & Ecosystems Program. The BCO-DMO is recognized in the 2011 Division of Ocean Sciences Sample and Data Policy as one of several program specific data offices that support NSF OCE funded researchers. BCO-DMO staff members offer data management support throughout the project life cycle to investigators from large national programs and medium-sized collaborative research projects, as well as researchers from single investigator awards. The office manages and serves all types of oceanographic data and information generated during the research process and contributed by the originating investigators. BCO-DMO has built a data system that includes the legacy data from several large ocean research programs (e.g. United States Joint Global Ocean Flux Study and United States GLOBal Ocean ECosystems Dynamics), to which data have been contributed from recently granted NSF OCE and OPP awards. The BCO-DMO data system can accommodate many different types of data including: in situ and experimental biological, chemical, and physical measurements; modeling results and synthesis data products. The system enables reuse of oceanographic data for new research endeavors, supports synthesis and modeling activities, provides availability of "real data" for K-12 and college level use, and provides decision-support field data for policy-relevant investigations. We will present an overview of the data management system capabilities including: map

  3. Whole ceramic-like microreactors from inorganic polymers for high temperature or/and high pressure chemical syntheses.

    PubMed

    Ren, Wurong; Perumal, Jayakumar; Wang, Jun; Wang, Hao; Sharma, Siddharth; Kim, Dong-Pyo

    2014-02-21

    Two types of whole ceramic-like microreactors were fabricated from inorganic polymers, polysilsesquioxane (POSS) and polyvinylsilazane (PVSZ), that were embedded with either perfluoroalkoxy (PFA) tube or polystyrene (PS) film templates, and subsequently the templates were removed by physical removal (PFA tube) or thermal decomposition (PS). A POSS derived ceramic-like microreactor with a 10 cm long serpentine channel was obtained by an additional "selective blocking of microchannel" step and subsequent annealing at 300 °C for 1 h, while a PVSZ derived ceramic-like microreactor with a 14 cm long channel was yielded by a co-firing process of the PVSZ-PS composite at 500 °C for 2 h that led to complete decomposition of the film template leaving a microchannel behind. The obtained whole ceramic-like microfluidic devices revealed excellent chemical and thermal stabilities in various solvents, and they were able to demonstrate unique chemical performance at high temperature or/and high pressure conditions such as Michaelis-Arbuzov rearrangement at 150-170 °C, Wolff-Kishner reduction at 200 °C, synthesis of super-paramagnetic Fe3O4 nanoparticles at 320 °C and isomerisation of allyloxybenzene to 2-allylphenol (250 °C and 400 psi). These economic ceramic-like microreactors fabricated by a facile non-lithographic method displayed excellent utility under challenging conditions that is superior to any plastic microreactors and comparable to glass and metal microreactors with high cost.

  4. Theory of chemical bonds in metalloenzymes V: Hybrid-DFT studies of the inorganic [8Fe-7S] core

    NASA Astrophysics Data System (ADS)

    Shoji, M.; Koizumi, K.; Kitagawa, Y.; Yamanaka, S.; Okumura, M.; Yamaguchi, K.; Ohki, Y.; Sunada, Y.; Honda, M.; Tatsumi, K.

    The electronic and spin structures of the [8Fe-7S] inorganic model complex (1) have been investigated using the density functional theory (DFT) UB3LYP and UBLYP methods. The experimental geometry of 1 was used to calculate the sets of exchange interactions (J values) between Fe-spin centers within spin Hamiltonian models. The experimental temperature-dependent paramagnetism is well reproduced on the basis of the calculated J values. The calculated low-lying energy levels are also consistent with those of the experiments. This indicates that the ground spin state of 1 is singlet (S = 0) for the weak antiferromagnetic coupling between two [4Fe-3S] cubane units, which take the Fe(III)Fe(II)3 formal charge and S = 7/2 spin states. The first-order density matrix of the most stable broken-symmetry (BS) solution has been diagonalized to elucidate the natural molecular orbitals (MOs) and their occupation number of 1, which are hardly obtained by the symmetry-adapted (SA) CASSCF approach. Several chemical indices such as the effective bond orders before and after spin projection are also calculated by using the occupation numbers to provide the SA MO picture of labile chemical bonds of 1. It is found that the BS MO calculation followed by spin-projected SA analysis is an effective and practical alternative to the CASSCF MO approach for the multinuclear transition metal clusters.

  5. Inorganic Nanomaterials as Carriers for Drug Delivery.

    PubMed

    Chen, Shizhu; Hao, Xiaohong; Liang, Xingjie; Zhang, Qun; Zhang, Cuimiao; Zhou, Guoqiang; Shen, Shigang; Jia, Guang; Zhang, Jinchao

    2016-01-01

    For safe and effective therapy, drugs must be delivered efficiently and with minimal systemic side effects. Nanostructured drug carriers enable the delivery of small-molecule drugs as well as nucleic acids and proteins. Inorganic nanomaterials are ideal for drug delivery platforms due to their unique physicochemical properties, such as facile preparation, good storage stability and biocompatibility. Many inorganic nanostructure-based drug delivery platforms have been prepared. Although there are still many obstacles to overcome, significant advances have been made in recent years. This review focuses on the status and development of inorganic nanostructures, including silica, quantum dots, gold, carbon-based and magnetic iron oxide-based nanostructures, as carriers for chemical and biological drugs. We specifically highlight the extensive use of these inorganic drug carriers for cancer therapy. Finally, we discuss the most important areas in the field that urgently require further study.

  6. Chemical and biological stability of solvent refined coal liquids

    SciTech Connect

    Wright, C.W.; Weimer, W.C.

    1984-01-01

    Stability studies performed on seventeen SRC samples in boiling point from ambient to 850/sup 0/F showed that the major chemical composition of the materials as monitored by high resolution gas chromatography did not change under the storage conditions of the repository, which were 4/sup 0/C, in inert containers, under a nitrogen atmosphere, in the dark. Samples were monitored after two years of storage. It was also found from microbial mutagenicity studies that after four years in the repository there was no significant change in the biological activity of any of the SRC materials. Samples stored under various parameters of air versus nitrogen atmosphere and ambient light versus darkness at room temperature and -20/sup 0/C for one year showed there was no significant differences in the chemical composition of any of the samples. There was evidence, however, that trace components such as amino-PAH degraded at room temperature, in the light, under an air atmosphere since the microbial mutagenicity of samples stored under these conditions for one year decreased significantly. Both the chemical composition and mutagenicity of FOB samples changed when stored diluted in methylene chloride, in the light, under an air atmosphere at room temperature. After one year of storage under these conditions, the microbial mutagenicity was eliminated. Storage of SRC-II FOB at increased temperatures of 60/sup 0/C and 100/sup 0/C showed significant changes in chemical composition due to volatility effects. The microbial mutagenicity of the FOB samples was completely eliminated after storage at 60/sup 0/C for 32 weeks and 100/sup 0/C for 26 weeks. It appears that the amino-PAH and phenolic materials are the most susceptible components to degradation in the complex SRC materials. 23 references, 29 figures, 50 tables.

  7. A Mechanistic Study of Chemically Modified Inorganic Membranes for Gas and Liquid Separations

    SciTech Connect

    Way, J Douglas

    2011-01-21

    This final report will summarize the progress made during the period August 1, 1993 - October 31, 2010 with support from DOE grant number DE-FG03-93ER14363. The objectives of the research have been to investigate the transport mechanisms in micro- and mesoporous, metal oxide membranes and to examine the relationship between the microstructure of the membrane, the membrane surface chemistry, and the separation performance of the membrane. Examples of the membrane materials under investigation are the microporous silica hollow fiber membrane manufactured by PPG Industries, chemically modified mesoporous oxide membranes, and polymer membranes containing microporous oxides (mixed matrix membranes). Analytical techniques such as NMR, FTIR and Raman spectroscopy, thermal analysis, and gas adsorption were used to investigate membrane microstructure and to probe the chemical interactions occurring at the gas-membrane interface.

  8. Chemical and biological approaches for mycotoxin control: a review.

    PubMed

    Edlayne, Gonçalez; Simone, Aquino; Felicio, Joana D

    2009-06-01

    Mycotoxins are metabolites and toxic substances produced by certain filamentous fungi that frequently contaminate food and agriculture commodities, which cause disease in animals or man. The toxigenic fungi belong to mainly three genera: Aspergillus, Penicillium and Fusarium. Examples of mycotoxins of greatest public health and agroeconomic significance include aflatoxins, ochratoxins, trichothecenes, zearalenone, fumonisins, patulin and ergot alkaloids. Commodities susceptible to direct contamination with mycotoxins include nuts, oilseeds and grains. Chemical and biological treatments have been attempted to minimize the risk of mycotoxins contamination or eliminate the fungi of food and feeds. One way to prevent or interfere with fungal growth and mycotoxin production is by use of synthetic or natural agents. Bacteria have been studied to control the mycotoxins production and fungal growth in food. Plant genotypes resistant to infection by toxigenic fungi have been also studied. This review will approach same patented methods applied to degrade, prevent and control of mycotoxins in food and feeds.

  9. BCTR: Biological and Chemical Technologies Research 1994 annual summary report

    SciTech Connect

    Petersen, G.

    1995-02-01

    The annual summary report presents the fiscal year (FY) 1994 research activities and accomplishments for the United States Department of Energy (DOE) Biological and Chemical Technologies Research (BCTR) Program of the Advanced Industrial Concepts Division (AICD). This AICD program resides within the Office of Industrial Technologies (OIT) of the Office of Energy Efficiency and Renewable Energy (EE). Although the OIT was reorganized in 1991 and AICD no longer exists, this document reports on efforts conducted under the former structure. The annual summary report for 1994 (ASR 94) contains the following: program description (including BCTR program mission statement, historical background, relevance, goals and objectives); program structure and organization, selected technical and programmatic highlights for 1994; detailed descriptions of individual projects; a listing of program output, including a bibliography of published work; patents, and awards arising from work supported by BCTR.

  10. Oxidizer gels for detoxification of chemical and biological agents

    DOEpatents

    Hoffman, Dennis M.; McGuire, Raymond R.

    2002-01-01

    A gel composition containing oxidizing agents and thickening or gelling agents is used to detoxify chemical and biological agents by application directly to a contaminated area. The gelling agent is a colloidal material, such as silica, alumina, or alumino-silicate clays, which forms a viscous gel that does not flow when applied to tilted or contoured surfaces. Aqueous or organic solutions of oxidizing agents can be readily gelled with less than about 30% colloidal material. Gel preparation is simple and suitable for field implementation, as the gels can be prepared at the site of decontamination and applied quickly and uniformly over an area by a sprayer. After decontamination, the residue can be washed away or vacuumed up for disposal.

  11. Medical experimentation concerning chemical and biological weapons for mass destruction.

    PubMed

    Deutsch, Erwin

    2003-04-01

    This article is the text of a speech originally presented at the Second World Conference on Medical Ethics at Gijon, Spain, on 2 October 2002 under the title "Medical Experimentation Concerning Chemical and Biological Weapons for Mass Destruction: Clinical Design for New Smallpox Vaccines: Ethical and Legal Aspects." Experimentation on vaccines such as smallpox is subject to the usual ethical rules such as the need for informed consent. However, the participants will not often be at risk of catching the disease but expose themselves by taking part in the experimentation. Professor Deutsch explores the implications of this, including the position of vulnerable groups such as children, those with mental handicaps, and those acting under orders such as the miliary, the policy and fire officers.

  12. Switchable electrode interfaces controlled by physical, chemical and biological signals.

    PubMed

    Bocharova, Vera; Katz, Evgeny

    2012-02-01

    Electrode interfaces functionalized with various signal-responsive materials have been designed to allow switchable properties of the modified electrodes. External signals of different nature (electrical potential, magnetic field, light, chemical/biochemical inputs) were applied to reversibly activate-deactivate the electrode interfaces upon demand. Multifunctional properties of the modified interfaces have allowed their responses to complex combinations of external signals. Further increase of their complexity has been achieved by integrating the signal-responsive interfaces with unconventional biomolecular computing systems logically processing multiple biochemical signals. This approach has resulted in electrochemical systems controlled by complex variations of biomarkers corresponding to different physiological conditions, thus allowing biological control over electronic systems. The switchable electrodes have been integrated with various "smart" biosensing and signal-processing systems and have been used to assemble biofuel cells producing power on demand.

  13. NSF-Sponsored Biological and Chemical Oceanography Data Management Office

    NASA Astrophysics Data System (ADS)

    Allison, M. D.; Chandler, C. L.; Copley, N.; Galvarino, C.; Gegg, S. R.; Glover, D. M.; Groman, R. C.; Wiebe, P. H.; Work, T. T.; Biological; Chemical Oceanography Data Management Office

    2010-12-01

    Ocean biogeochemistry and marine ecosystem research projects are inherently interdisciplinary and benefit from improved access to well-documented data. Improved data sharing practices are important to the continued exploration of research themes that are a central focus of the ocean science community and are essential to interdisciplinary and international collaborations that address complex, global research themes. In 2006, the National Science Foundation Division of Ocean Sciences (NSF OCE) funded the Biological and Chemical Oceanography Data Management Office (BCO-DMO) to serve the data management requirements of scientific investigators funded by the National Science Foundation’s Biological and Chemical Oceanography Sections. BCO-DMO staff members work with investigators to manage marine biogeochemical, ecological, and oceanographic data and information developed in the course of scientific research. These valuable data sets are documented, stored, disseminated, and protected over short and intermediate time frames. One of the goals of the BCO-DMO is to facilitate regional, national, and international data and information exchange through improved data discovery, access, display, downloading, and interoperability. In May 2010, NSF released a statement to the effect that in October 2010, it is planning to require that all proposals include a data management plan in the form of a two-page supplementary document. The data management plan would be an element of the merit review process. NSF has long been committed to making data from NSF-funded research publicly available and the new policy will strengthen this commitment. BCO-DMO is poised to assist in creating the data management plans and in ultimately serving the data and information resulting from NSF OCE funded research. We will present an overview of the data management system capabilities including: geospatial and text-based data discovery and access systems; recent enhancements to data search tools; data

  14. In-silico identification and characterization of organic and inorganic chemical stress responding genes in yeast (Saccharomyces cerevisiae).

    PubMed

    Barozai, Muhammad Younas Khan; Bashir, Farrukh; Muzaffar, Shafia; Afzal, Saba; Behlil, Farida; Khan, Muzaffar

    2014-10-15

    To study the life processes of all eukaryotes, yeast (Saccharomyces cerevisiae) is a significant model organism. It is also one of the best models to study the responses of genes at transcriptional level. In a living organism, gene expression is changed by chemical stresses. The genes that give response to chemical stresses will provide good source for the strategies in engineering and formulating mechanisms which are chemical stress resistant in the eukaryotic organisms. The data available through microarray under the chemical stresses like lithium chloride, lactic acid, weak organic acids and tomatidine were studied by using computational tools. Out of 9335 yeast genes, 388 chemical stress responding genes were identified and characterized under different chemical stresses. Some of these are: Enolases 1 and 2, heat shock protein-82, Yeast Elongation Factor 3, Beta Glucanase Protein, Histone H2A1 and Histone H2A2 Proteins, Benign Prostatic Hyperplasia, ras GTPase activating protein, Establishes Silent Chromatin protein, Mei5 Protein, Nondisjunction Protein and Specific Mitogen Activated Protein Kinase. Characterization of these genes was also made on the basis of their molecular functions, biological processes and cellular components.

  15. Chemical and biological warfare: Biology, chemistry, and toxicology. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1997-11-01

    The bibliography contains citations concerning the physiological effects, physicochemical effects, and toxicology of chemical and biological warfare agents. Citations discuss toxic chemicals, chemical agent simulants, detoxification and decontamination, environmental toxicity, and land pollution. Detection techniques and warning systems are examined in a separate bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Chemical and biological warfare: Biology, chemistry, and toxicology. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-03-01

    The bibliography contains citations concerning the physiological effects, physicochemical effects, and toxicology of chemical and biological warfare agents. Citations discuss toxic chemicals, chemical agent simulants, detoxification and decontamination, environmental toxicity, and land pollution. Detection techniques and warning systems are examined in a separate bibliography. (Contains a minimum of 229 citations and includes a subject term index and title list.)

  17. Chemical and biological warfare: Biology, chemistry, and toxicology. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-10-01

    The bibliography contains citations concerning the physiological effects, physicochemical effects, and toxicology of chemical and biological warfare agents. Citations discuss toxic chemicals, chemical agent simulants, detoxification and decontamination, environmental toxicity, and land pollution. Detection techniques and warning systems are examined in a separate bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  18. Chemical and biological warfare: Biology, chemistry, and toxicology. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-10-01

    The bibliography contains citations concerning the physiological effects, physicochemical effects, and toxicology of chemical and biological warfare agents. Citations discuss toxic chemicals, chemical agent simulants, detoxification and decontamination, environmental toxicity, and land pollution. Detection techniques and warning systems are examined in a separate bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  19. Chemical Variability and Biological Activities of Eucalyptus spp. Essential Oils.

    PubMed

    Barbosa, Luiz Claudio Almeida; Filomeno, Claudinei Andrade; Teixeira, Robson Ricardo

    2016-12-07

    Many plant species produce mixtures of odorous and volatile compounds known as essential oils (EOs). These mixtures play important roles in Nature and have been utilized by mankind for different purposes, such as pharmaceuticals, agrochemicals, aromatherapy, and food flavorants. There are more than 3000 EOs reported in the literature, with approximately 300 in commercial use, including the EOs from Eucalyptus species. Most EOs from Eucalyptus species are rich in monoterpenes and many have found applications in pharmaceuticals, agrochemicals, food flavorants, and perfumes. Such applications are related to their diverse biological and organoleptic properties. In this study, we review the latest information concerning the chemical composition and biological activities of EOs from different species of Eucalyptus. Among the 900 species and subspecies of the Eucalyptus genus, we examined 68 species. The studies associated with these species were conducted in 27 countries. We have focused on the antimicrobial, acaricidal, insecticidal and herbicidal activities, hoping that such information will contribute to the development of research in this field. It is also intended that the information described in this study can be useful in the rationalization of the use of Eucalyptus EOs as components for pharmaceutical and agrochemical applications as well as food preservatives and flavorants.

  20. Chemical biology of homocysteine thiolactone and related metabolites.

    PubMed

    Jakubowski, Hieronim; Głowacki, Rafał

    2011-01-01

    Protein-related homocysteine (Hcy) metabolism produces Hcy-thiolactone, N-Hcy-protein, and N epsilon-homocysteinyl-lysine (N epsilon-Hcy-Lys). Hcy-thiolactone is generated in an error-editing reaction in protein biosynthesis when Hcy is erroneously selected in place of methionine by methionyl-tRNA synthetase. Hcy-thiolactone, an intramolecular thioester, is chemically reactive and forms isopeptide bonds with protein lysine residues in a process called N-homocysteinylation, which impairs or alters the protein's biological function. The resulting protein damage is exacerbated by a thiyl radical-mediated oxidation. N-Hcy-proteins undergo structural changes leading to aggregation and amyloid formation. These structural changes generate proteins, which are toxic and which induce an autoimmune response. Proteolytic degradation of N-Hcy-proteins generates N epsilon-Hcy-Lys. Levels of Hcy-thiolactone, N-Hcy-protein, and N epsilon-Hcy-Lys increase under pathological conditions in humans and mice and have been linked to cardiovascular and brain disorders. This chapter reviews fundamental biological chemistry of Hcy-thiolactone, N-Hcy-protein, and N epsilon-Hcy-Lys and discusses their clinical significance.

  1. Sensitizers on inorganic carriers for decomposition of the chemical warfare agent yperite.

    PubMed

    Cojocaru, Bogdan; Parvulescu, Vasile I; Preda, Elena; Iepure, Gabriel; Somoghi, Vasile; Carbonell, Esther; Alvaro, Mercedes; García, Hermenegildo

    2008-07-01

    Sulfur-containing compounds, such as mercaptans, alkali sulfides, alkali sulfites, and alkali thiosulfates, are byproducts of industrial processes and pollutants of waste and natural waters. Other sulfur-containing compounds such as yperite are dangerous chemical weapons. Efficient photocatalytic decomposition of these molecules is a process that can find applications in emergency situations or for the controlled destruction of chemical warfare stockpiles. A series of heterogeneous photocatalysts consisting of a metal phthalocyanine or 2,4,6-triphenylpyrylium as photoactive components encapsulated inside the cavities of zeolite Y or the mesoporous channels of MCM-41 or supported on silica or titania-silica was tested for the photocatalytic decomposition of yperite. Two types of photoreactors, either an open reactor naturally aerated or a closed quartz tube with a constant airflow using UV or visible ambient light were used. These tests demonstrated that iron and manganese phthalocyanine and 2,4,6-triphenylpyrylium embedded in NaY or titania-silica can be suitable solid photocatalysts for the degradation of yperite using UV and visible irradiation.

  2. 15 CFR 742.2 - Proliferation of chemical and biological weapons.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... biological weapons. 742.2 Section 742.2 Commerce and Foreign Trade Regulations Relating to Commerce and... REGULATIONS CONTROL POLICY-CCL BASED CONTROLS § 742.2 Proliferation of chemical and biological weapons. (a... opposing the proliferation and illegal use of chemical and biological weapons. (See also § 742.18 of...

  3. 15 CFR 742.2 - Proliferation of chemical and biological weapons.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... biological weapons. 742.2 Section 742.2 Commerce and Foreign Trade Regulations Relating to Commerce and... REGULATIONS CONTROL POLICY-CCL BASED CONTROLS § 742.2 Proliferation of chemical and biological weapons. (a... opposing the proliferation and illegal use of chemical and biological weapons. (See also § 742.18 of...

  4. 15 CFR 742.2 - Proliferation of chemical and biological weapons.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... biological weapons. 742.2 Section 742.2 Commerce and Foreign Trade Regulations Relating to Commerce and... REGULATIONS CONTROL POLICY-CCL BASED CONTROLS § 742.2 Proliferation of chemical and biological weapons. (a... opposing the proliferation and illegal use of chemical and biological weapons. (See also § 742.18 of...

  5. 15 CFR 742.2 - Proliferation of chemical and biological weapons.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... biological weapons. 742.2 Section 742.2 Commerce and Foreign Trade Regulations Relating to Commerce and... REGULATIONS CONTROL POLICY-CCL BASED CONTROLS § 742.2 Proliferation of chemical and biological weapons. (a... opposing the proliferation and illegal use of chemical and biological weapons. (See also § 742.18 of...

  6. Biological and chemical characteristics of the coral gastric cavity

    NASA Astrophysics Data System (ADS)

    Agostini, S.; Suzuki, Y.; Higuchi, T.; Casareto, B. E.; Yoshinaga, K.; Nakano, Y.; Fujimura, H.

    2012-03-01

    All corals have a common structure: two tissue layers enclose a lumen, which forms the gastric cavity. Few studies have described the processes occurring inside the gastric cavity and its chemical and biological characteristics. Here, we show that the coral gastric cavity has distinct chemical characteristics with respect to dissolved O2, pH, alkalinity, and nutrients (vitamin B12, nitrate, nitrite, ammonium, and phosphate) and also harbors a distinct bacterial community. From these results, the gastric cavity can be described as a semi-closed sub-environment within the coral. Dissolved O2 shows very low constant concentrations in the deepest parts of the cavity, creating a compartmentalized, anoxic environment. The pH is lower in the cavity than in the surrounding water and, like alkalinity, shows day/night variations different from those of the surrounding water. Nutrient concentrations in the cavity are greater than the concentrations found in reef waters, especially for phosphate and vitamin B12. The source of these nutrients may be internal production by symbiotic bacteria and/or the remineralization of organic matter ingested or produced by the corals. The importance of the bacteria inhabiting the gastric cavity is supported by the finding of a high bacterial abundance and a specific bacterial community with affiliation to bacteria found in other corals and in the guts of other organisms. The findings presented here open a new area of research that may help us to understand the processes that maintain coral health.

  7. The chemical information ontology: provenance and disambiguation for chemical data on the biological semantic web.

    PubMed

    Hastings, Janna; Chepelev, Leonid; Willighagen, Egon; Adams, Nico; Steinbeck, Christoph; Dumontier, Michel

    2011-01-01

    Cheminformatics is the application of informatics techniques to solve chemical problems in silico. There are many areas in biology where cheminformatics plays an important role in computational research, including metabolism, proteomics, and systems biology. One critical aspect in the application of cheminformatics in these fields is the accurate exchange of data, which is increasingly accomplished through the use of ontologies. Ontologies are formal representations of objects and their properties using a logic-based ontology language. Many such ontologies are currently being developed to represent objects across all the domains of science. Ontologies enable the definition, classification, and support for querying objects in a particular domain, enabling intelligent computer applications to be built which support the work of scientists both within the domain of interest and across interrelated neighbouring domains. Modern chemical research relies on computational techniques to filter and organise data to maximise research productivity. The objects which are manipulated in these algorithms and procedures, as well as the algorithms and procedures themselves, enjoy a kind of virtual life within computers. We will call these information entities. Here, we describe our work in developing an ontology of chemical information entities, with a primary focus on data-driven research and the integration of calculated properties (descriptors) of chemical entities within a semantic web context. Our ontology distinguishes algorithmic, or procedural information from declarative, or factual information, and renders of particular importance the annotation of provenance to calculated data. The Chemical Information Ontology is being developed as an open collaborative project. More details, together with a downloadable OWL file, are available at http://code.google.com/p/semanticchemistry/ (license: CC-BY-SA).

  8. Lignin valorization through integrated biological funneling and chemical catalysis

    PubMed Central

    Linger, Jeffrey G.; Vardon, Derek R.; Guarnieri, Michael T.; Karp, Eric M.; Hunsinger, Glendon B.; Franden, Mary Ann; Johnson, Christopher W.; Chupka, Gina; Strathmann, Timothy J.; Pienkos, Philip T.; Beckham, Gregg T.

    2014-01-01

    Lignin is an energy-dense, heterogeneous polymer comprised of phenylpropanoid monomers used by plants for structure, water transport, and defense, and it is the second most abundant biopolymer on Earth after cellulose. In production of fuels and chemicals from biomass, lignin is typically underused as a feedstock and burned for process heat because its inherent heterogeneity and recalcitrance make it difficult to selectively valorize. In nature, however, some organisms have evolved metabolic pathways that enable the utilization of lignin-derived aromatic molecules as carbon sources. Aromatic catabolism typically occurs via upper pathways that act as a “biological funnel” to convert heterogeneous substrates to central intermediates, such as protocatechuate or catechol. These intermediates undergo ring cleavage and are further converted via the β-ketoadipate pathway to central carbon metabolism. Here, we use a natural aromatic-catabolizing organism, Pseudomonas putida KT2440, to demonstrate that these aromatic metabolic pathways can be used to convert both aromatic model compounds and heterogeneous, lignin-enriched streams derived from pilot-scale biomass pretreatment into medium chain-length polyhydroxyalkanoates (mcl-PHAs). mcl-PHAs were then isolated from the cells and demonstrated to be similar in physicochemical properties to conventional carbohydrate-derived mcl-PHAs, which have applications as bioplastics. In a further demonstration of their utility, mcl-PHAs were catalytically converted to both chemical precursors and fuel-range hydrocarbons. Overall, this work demonstrates that the use of aromatic catabolic pathways enables an approach to valorize lignin by overcoming its inherent heterogeneity to produce fuels, chemicals, and materials. PMID:25092344

  9. Lignin valorization through integrated biological funneling and chemical catalysis.

    PubMed

    Linger, Jeffrey G; Vardon, Derek R; Guarnieri, Michael T; Karp, Eric M; Hunsinger, Glendon B; Franden, Mary Ann; Johnson, Christopher W; Chupka, Gina; Strathmann, Timothy J; Pienkos, Philip T; Beckham, Gregg T

    2014-08-19

    Lignin is an energy-dense, heterogeneous polymer comprised of phenylpropanoid monomers used by plants for structure, water transport, and defense, and it is the second most abundant biopolymer on Earth after cellulose. In production of fuels and chemicals from biomass, lignin is typically underused as a feedstock and burned for process heat because its inherent heterogeneity and recalcitrance make it difficult to selectively valorize. In nature, however, some organisms have evolved metabolic pathways that enable the utilization of lignin-derived aromatic molecules as carbon sources. Aromatic catabolism typically occurs via upper pathways that act as a "biological funnel" to convert heterogeneous substrates to central intermediates, such as protocatechuate or catechol. These intermediates undergo ring cleavage and are further converted via the β-ketoadipate pathway to central carbon metabolism. Here, we use a natural aromatic-catabolizing organism, Pseudomonas putida KT2440, to demonstrate that these aromatic metabolic pathways can be used to convert both aromatic model compounds and heterogeneous, lignin-enriched streams derived from pilot-scale biomass pretreatment into medium chain-length polyhydroxyalkanoates (mcl-PHAs). mcl-PHAs were then isolated from the cells and demonstrated to be similar in physicochemical properties to conventional carbohydrate-derived mcl-PHAs, which have applications as bioplastics. In a further demonstration of their utility, mcl-PHAs were catalytically converted to both chemical precursors and fuel-range hydrocarbons. Overall, this work demonstrates that the use of aromatic catabolic pathways enables an approach to valorize lignin by overcoming its inherent heterogeneity to produce fuels, chemicals, and materials.

  10. Future of Chemical Engineering: Integrating Biology into the Undergraduate ChE Curriculum

    ERIC Educational Resources Information Center

    Mosto, Patricia; Savelski, Mariano; Farrell, Stephanie H.; Hecht, Gregory B.

    2007-01-01

    Integrating biology in the chemical engineering curriculum seems to be the future for chemical engineering programs nation and worldwide. Rowan University's efforts to address this need include a unique chemical engineering curriculum with an intensive biology component integrated throughout from freshman to senior years. Freshman and Sophomore…

  11. 15 CFR Supplement No. 1 to Part 742 - Nonproliferation of Chemical and Biological Weapons

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Biological Weapons No. Supplement No. 1 to Part 742 Commerce and Foreign Trade Regulations Relating to...—Nonproliferation of Chemical and Biological Weapons Note: Exports and reexports of items in performance of...: (i) Equipment (for producing chemical weapon precursors and chemical warfare agents) described...

  12. 15 CFR Supplement No. 1 to Part 742 - Nonproliferation of Chemical and Biological Weapons

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Biological Weapons No. Supplement No. 1 to Part 742 Commerce and Foreign Trade Regulations Relating to...—Nonproliferation of Chemical and Biological Weapons Note: Exports and reexports of items in performance of...: (i) Equipment (for producing chemical weapon precursors and chemical warfare agents) described...

  13. 15 CFR Supplement No. 1 to Part 742 - Nonproliferation of Chemical and Biological Weapons

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Biological Weapons No. Supplement No. 1 to Part 742 Commerce and Foreign Trade Regulations Relating to...—Nonproliferation of Chemical and Biological Weapons Note: Exports and reexports of items in performance of...: (i) Equipment (for producing chemical weapon precursors and chemical warfare agents) described...

  14. 15 CFR Supplement No. 1 to Part 742 - Nonproliferation of Chemical and Biological Weapons

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Biological Weapons No. Supplement No. 1 to Part 742 Commerce and Foreign Trade Regulations Relating to...—Nonproliferation of Chemical and Biological Weapons Note: Exports and reexports of items in performance of...: (i) Equipment (for producing chemical weapon precursors and chemical warfare agents) described...

  15. 15 CFR Supplement No. 1 to Part 742 - Nonproliferation of Chemical and Biological Weapons

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Biological Weapons No. Supplement No. 1 to Part 742 Commerce and Foreign Trade Regulations Relating to...—Nonproliferation of Chemical and Biological Weapons Note: Exports and reexports of items in performance of...: (i) Equipment (for producing chemical weapon precursors and chemical warfare agents) described...

  16. Effect of inorganic nutrients on the acclimation period preceding mineralization of organic chemicals in lake water

    SciTech Connect

    Jones, S.H.; Alexander, M.

    1988-12-01

    The addition of phosphate, nitrate, or sulfate (each at 10 mM) decreased the acclimation period for the mineralization of low concentrations of p-nitrophenol (PNP) in lake water. Added phosphate shortened the acclimation period for biodegradation of 2 ng to 2 micrograms of PNP per ml in various lake water samples and of 2,4-dichlorophenoxyacetate at 100 ng/ml. Added P enhanced the rate of growth of PNP-mineralizing microorganisms in waters containing 200 ng or 2 micrograms of PNP per ml. We suggest that the effect of P on the acclimation period results from an increase in the growth rate of the initially small population of microorganisms able to mineralize the synthetic chemicals.

  17. Comparative study of line roughness metrics of chemically amplified and inorganic resists for EUV

    NASA Astrophysics Data System (ADS)

    Fallica, Roberto; Buitrago, Elizabeth; Ekinci, Yasin

    2016-03-01

    We present a comprehensive study of the roughness metrics of different resists. Dense line/space (L/S) images of polymethyl methacrylate (PMMA), hydrogen silsesquioxane (HSQ), different chemically amplified resists (CARs), and metal oxide based resists have been patterned by extreme ultraviolet interference lithography (EUV-IL). The three line width roughness metrics: r.m.s. value σLWR, correlation length ξ and roughness exponent α, were measured by metrological analysis of top down SEM images and compared for the different resists imaged here. It was found, that all metrics are required to fully describe the roughness of each resist. Our measurements indicate that few of the state-of-the- art resists tested here can meet the International Technology Roadmap for Semiconductors (ITRS) requirements for σLWR. The correlation length ξ has been found to be considerably higher in polymer-based materials in comparison to non-polymers. The roughness exponent α, interpreted using the concept of fractal geometry, is mainly affected by acid diffusion in CARs where it produces line edges with a higher complexity than in non-CAR resists. These results indicate that different resists platforms show very different LWR resist metrics and roughness is not only manifested in the σLWR but in all parameters. Therefore, all roughness metrics should be taken into account in the performance comparison of the resist, since they can have a substantial impact on the device performance.

  18. Principles of Chemical Bonding and Band Gap Engineering in Hybrid Organic–Inorganic Halide Perovskites

    PubMed Central

    2015-01-01

    The performance of solar cells based on hybrid halide perovskites has seen an unparalleled rate of progress, while our understanding of the underlying physical chemistry of these materials trails behind. Superficially, CH3NH3PbI3 is similar to other thin-film photovoltaic materials: a semiconductor with an optical band gap in the optimal region of the electromagnetic spectrum. Microscopically, the material is more unconventional. Progress in our understanding of the local and long-range chemical bonding of hybrid perovskites is discussed here, drawing from a series of computational studies involving electronic structure, molecular dynamics, and Monte Carlo simulation techniques. The orientational freedom of the dipolar methylammonium ion gives rise to temperature-dependent dielectric screening and the possibility for the formation of polar (ferroelectric) domains. The ability to independently substitute on the A, B, and X lattice sites provides the means to tune the optoelectronic properties. Finally, ten critical challenges and opportunities for physical chemists are highlighted. PMID:25838846

  19. Comparative study of line roughness metrics of chemically amplified and inorganic resists for extreme ultraviolet

    NASA Astrophysics Data System (ADS)

    Fallica, Roberto; Buitrago, Elizabeth; Ekinci, Yasin

    2016-07-01

    We present a comprehensive comparative study of the roughness metrics of different resists. Dense line/space of polymethyl methacrylate, hydrogen silsesquioxane, a metal oxide-based resist, and different chemically amplified resists (CARs) have been patterned by extreme ultraviolet interference lithography. All three line width roughness (LWR) metrics: the root-mean-square (r.m.s.) roughness value σLWR, the correlation length ξ, and the roughness exponent α, were extracted by metrological analysis of top-down SEM images. We found that all metrics are required to fully describe the overall roughness of each resist. Our measurements indicate that in fact, a few of the state-of-the-art resists tested here can meet the International Technology Roadmap for Semiconductors requirements for σLWR. The correlation length ξ was also found to be considerably higher in polymer-based materials in comparison to nonpolymers. Finally, the roughness exponent α, interpreted using the concept of fractal geometry, was found to be mainly affected by acid diffusion in CARs, where it produces line edges with a higher complexity than in non-CAR resists. These results indicate that the different resists platforms show very different LWR metrics and roughness is not manifested only in the σLWR but in all parameters. Therefore, all roughness metrics should be taken into account when comparing the performance among different resists since they ultimately have a substantial impact on device performance.

  20. Structural and chemical characterization of inorganic deposits in calcified human mitral valve.

    PubMed

    Bigi, A; Compostella, L; Fichera, A M; Foresti, E; Gazzano, M; Ripamonti, A; Roveri, N

    1988-10-01

    X-ray diffraction, i.r. absorption, and chemical analyses have been carried out on the mineral deposits of calcified human mitral valves and glutaraldehyde-preserved porcine aortic grafts. The mineral deposits isolated from highly calcified mitral valves and porcine aortic grafts are constituted of type B-carbonate apatite. Magnesium substituted beta-tricalcium phosphate is present, together with an apatitic phase similar to dahllite, in the ashes of poorly calcified mitral valves. The contraction of the unit cell of beta-tricalcium phosphate due to magnesium incorporation is compared with the variation of the lattice constants of synthetic beta-tricalcium phosphate at different degree of magnesium substitution for calcium. The results reveal the important role of magnesium on the calcification of human valves. In fact, the apatitic phase deposited at the beginning of the calcification process, when there is a high magnesium content, converts completely into beta-tricalcium phosphate by heat treatment at 1,000 degrees C. On the other hand, when the calcification becomes massive, magnesium content appears highly reduced, and the deposited apatitic phase is characterized by a high thermal stability.

  1. Chemical speciation of inorganic compounds under hydrothermal conditions. 1998 annual progress report

    SciTech Connect

    Stern, E.A.; Fulton, J.L.; Darab, J.G.; Steidler, G.T.

    1998-06-01

    'To obtain the chemistry of metallic solute ions under aqueous and hydrothermal conditions in order to obtain key insights pertinent to the removal of toxic wastes. Elements present in Hanford tank wastes will be investigated to get a better understanding of how the high temperatures involved in vitrification will affect the hydrolysis-polymerization reaction. In the following summary of the x-ray absorption fine structure (XAFS) measurements under aqueous and hydrothermal conditions, most measurements below the critical temperature (375 C) were taken at about 200 bar pressure, while at supercritical temperatures the pressure was about 600 bar. Chemistry of Na{sub 2} WO{sub 4} Under Aqueous and Hydrothermal Conditions Tungsten, molybdenum, vanadium and, to a lesser agree, chromium, niobium and tantalum form isopolymetallates, polymeric species of rather complicated structure and complex chemical equilibria, in aqueous solution upon acidification. Except Tantalum, all of these elements are present in the Hanford tank wastes and it is not well understood how the high temperatures involved in vitrification will affect the hydrolysis-polymerization reaction. In March 1998, the authors launched a series of XAFS experiments to resolve these questions. Measurements were obtained for 0.2 molal tungstate solutions as a function of temperature (to 200 C) and as a function of starting pH. The outcome of these measurements is providing key insights into this chemistry as follows: (1) A change from tetrahedral to octahedral coordination of the oxygen atoms around the tungsten center atom can be detected upon increasing extent of polymerization. (2) At least one new feature shows up in the Fourier Transform of the k-weighted Chi plot (closely related to a radial distribution function) which is unambiguously attributed to a tungsten-tungsten scattering path, only present in the polymeric species. (3) Perhaps most interestingly, the XAFS data indicate a higher extent of

  2. External Quality Assessment Scheme for Biological Monitoring of Occupational Exposure to Toxic Chemicals

    PubMed Central

    Lee, Mi-Young; Kang, Seong-Kyu

    2011-01-01

    Objectives In this study, we summarized the External Quality Assessment Scheme (EQAS) for the biological monitoring of occupational exposure to toxic chemicals which started in 1995 and continued until a 31st round robin in the spring of 2010. The program was performed twice per year until 2009, and this was changed to once a year since 2010. The objective of the program is to ensure the reliability of the data related to biological monitoring from analytical laboratories. Methods One hundred and eighteen laboratories participated in the 31st round robin. The program offers 5 items for inorganic analysis: lead in blood, cadmium in blood, manganese in blood, cadmium in urine, and mercury in urine. It also offers 10 items for organic analysis, including hippuric acid, methylhippuric acid, mandelic acid, phenylglyoxylic acid, N-methylformamide, N-methylacetamide, trichloroacetic acid, total trichloro-compounds, trans,trans-muconic acid, and 2,5-hexanedione in urine. Target values were determined by statistical analysis using consensus values. All the data, such as chromatograms and calibration curves, were reviewed by the committee. Results The proficiency rate was below 70% prior to the first round robin and improved to over 90% for common items, such as PbB and HA, while those for other items still remained in the range of 60-90% and need to be improved up to 90%. Conclusion The EQAS has taken a primary role in improving the reliability of analytical data. A total quality assurance scheme is suggested, including the validation of technical documentation for the whole analytical procedure. PMID:22953206

  3. MECs: "Building Blocks" for Creating Biological and Chemical Instruments

    PubMed Central

    Hill, Douglas A.; Anderson, Lindsey E.; Hill, Casey J.; Mostaghim, Afshin; Rodgers, Victor G. J.

    2016-01-01

    The development of new biological and chemical instruments for research and diagnostic applications is often slowed by the cost, specialization, and custom nature of these instruments. New instruments are built from components that are drawn from a host of different disciplines and not designed to integrate together, and once built, an instrument typically performs a limited number of tasks and cannot be easily adapted for new applications. Consequently, the process of inventing new instruments is very inefficient, especially for researchers or clinicians in resource-limited settings. To improve this situation, we propose that a family of standardized multidisciplinary components is needed, a set of “building blocks” that perform a wide array of different tasks and are designed to integrate together. Using these components, scientists, engineers, and clinicians would be able to build custom instruments for their own unique needs quickly and easily. In this work we present the foundation of this set of components, a system we call Multifluidic Evolutionary Components (MECs). “Multifluidic” conveys the wide range of fluid volumes MECs operate upon (from nanoliters to milliliters and beyond); “multi” also reflects the multiple disciplines supported by the system (not only fluidics but also electronics, optics, and mechanics). “Evolutionary” refers to the design principles that enable the library of MEC parts to easily grow and adapt to new applications. Each MEC “building block” performs a fundamental function that is commonly found in biological or chemical instruments, functions like valving, pumping, mixing, controlling, and sensing. Each MEC also has a unique symbol linked to a physical definition, which enables instruments to be designed rapidly and efficiently using schematics. As a proof-of-concept, we use MECs to build a variety of instruments, including a fluidic routing and mixing system capable of manipulating fluid volumes over five

  4. MECs: "Building Blocks" for Creating Biological and Chemical Instruments.

    PubMed

    Hill, Douglas A; Anderson, Lindsey E; Hill, Casey J; Mostaghim, Afshin; Rodgers, Victor G J; Grover, William H

    2016-01-01

    The development of new biological and chemical instruments for research and diagnostic applications is often slowed by the cost, specialization, and custom nature of these instruments. New instruments are built from components that are drawn from a host of different disciplines and not designed to integrate together, and once built, an instrument typically performs a limited number of tasks and cannot be easily adapted for new applications. Consequently, the process of inventing new instruments is very inefficient, especially for researchers or clinicians in resource-limited settings. To improve this situation, we propose that a family of standardized multidisciplinary components is needed, a set of "building blocks" that perform a wide array of different tasks and are designed to integrate together. Using these components, scientists, engineers, and clinicians would be able to build custom instruments for their own unique needs quickly and easily. In this work we present the foundation of this set of components, a system we call Multifluidic Evolutionary Components (MECs). "Multifluidic" conveys the wide range of fluid volumes MECs operate upon (from nanoliters to milliliters and beyond); "multi" also reflects the multiple disciplines supported by the system (not only fluidics but also electronics, optics, and mechanics). "Evolutionary" refers to the design principles that enable the library of MEC parts to easily grow and adapt to new applications. Each MEC "building block" performs a fundamental function that is commonly found in biological or chemical instruments, functions like valving, pumping, mixing, controlling, and sensing. Each MEC also has a unique symbol linked to a physical definition, which enables instruments to be designed rapidly and efficiently using schematics. As a proof-of-concept, we use MECs to build a variety of instruments, including a fluidic routing and mixing system capable of manipulating fluid volumes over five orders of magnitude, an

  5. A New Data Management System for Biological and Chemical Oceanography

    NASA Astrophysics Data System (ADS)

    Groman, R. C.; Chandler, C.; Allison, D.; Glover, D. M.; Wiebe, P. H.

    2007-12-01

    The Biological and Chemical Oceanography Data Management Office (BCO-DMO) was created to serve PIs principally funded by NSF to conduct marine chemical and ecological research. The new office is dedicated to providing open access to data and information developed in the course of scientific research on short and intermediate time-frames. The data management system developed in support of U.S. JGOFS and U.S. GLOBEC programs is being modified to support the larger scope of the BCO-DMO effort, which includes ultimately providing a way to exchange data with other data systems. The open access system is based on a philosophy of data stewardship, support for existing and evolving data standards, and use of public domain software. The DMO staff work closely with originating PIs to manage data gathered as part of their individual programs. In the new BCO-DMO data system, project and data set metadata records designed to support re-use of the data are stored in a relational database (MySQL) and the data are stored in or made accessible by the JGOFS/GLOBEC object- oriented, relational, data management system. Data access will be provided via any standard Web browser client user interface through a GIS application (Open Source, OGC-compliant MapServer), a directory listing from the data holdings catalog, or a custom search engine that facilitates data discovery. In an effort to maximize data system interoperability, data will also be available via Web Services; and data set descriptions will be generated to comply with a variety of metadata content standards. The office is located at the Woods Hole Oceanographic Institution and web access is via http://www.bco-dmo.org.

  6. Controlling biological deterioration of wood with volatile chemicals. Final report

    SciTech Connect

    Graham, R.D.; Corden, M.E.

    1980-08-01

    Volatile fungicides placed in holes in pressure-treated Douglas-fir transmission poles with internal decay diffuse as vapors for about 2.4 m above and below the groundline to control decay for at least 10 y. The presence of fungitoxic vapors of chloropicrin (trichloronitromethane) in these poles suggests added years of control. Vapam (sodium N-methyldithiocarbamate) was less effective, but both of these chemicals are used nationwide. Methylisotiocyanate (MS), which appears especially promising in both laboratory wood-block screening tests and in poles 2 years after treatment, may prove outstanding as a control for internal decay of poles. Successfully formulated as a solid, MS could increase the safety and versatility of fumigant use. A comparison of devices for inspecting Douglas-fir poles for decay emphasized the importance of having well-trained inspectors who know the limitations of the tools and methods they use. A manual for the maintenance of Douglas-fir and western redcedar poles was published to aid inspectors and managers of wood pole systems. Fumigants varied in their residual protection against invasion by decay fungi with chloropicrin having the highest residual fungitoxicity. Fumigants had no adverse effect on vegetation around poles, nor on the strength properties of wood. Of the 8 decay fungi isolated from over 15,600 pressure-treated Douglas-fir poles, Poria carbonica and Poria placenta were by far the most prevalent. Of the five most prevalent nondecay fungi isolated from these poles, a Scytalidium species can produce an environment unsuitable for reinvasion of the wood by decay fungi. The resistance of the Scytalidium species to chloropicrin raises the possibility of a combined chemical-biological control of internal decay.

  7. THz-Raman spectroscopy for explosives, chemical, and biological detection

    NASA Astrophysics Data System (ADS)

    Carriere, James T. A.; Havermeyer, Frank; Heyler, Randy A.

    2013-05-01

    Raman and Terahertz spectroscopy are both widely used for their ability to safely and remotely identify unknown materials. Each approach has its advantages and disadvantages. Traditional Raman spectroscopy typically measures molecular energy transitions in the 200-5000cm-1 region corresponding to sub-molecular stretching or bending transitions, while Terahertz spectroscopy measures molecular energy transitions in the 1-200cm-1 region (30GHz - 6THz) that correspond to low energy rotational modes or vibrational modes of the entire molecule. Many difficult to detect explosives and other hazardous chemicals are known to have multiple relatively strong transitions in this "Terahertz" (<200cm-1, <6THz) regime, suggesting this method as a powerful complementary approach for identification. However, THz signal generation is often expensive, many THz spectroscopy systems are limited to just a few THz range, and strong water absorption bands in this region can act to mask certain transitions if great care isn't taken during sample preparation. Alternatively, low-frequency or "THz-Raman" spectroscopy, which covers the ~5cm-1 to 200cm-1 (150GHz - 6 THz) regions and beyond, offers a powerful, compact and economical alternative to probe these low energy transitions. We present results from a new approach for extending the range of Raman spectroscopy into the Terahertz regime using an ultra-narrow-band volume holographic grating (VHG) based notch filter system. An integrated, compact Raman system is demonstrated utilizing a single stage spectrometer to show both Stokes and anti-Stokes measurements down to <10cm-1 on traditionally difficult to detect explosives, as well as other chemical and biological samples.

  8. Terahertz spectroscopy for chemicals and biological sensing applications

    NASA Astrophysics Data System (ADS)

    Liu, Hai-Bo

    probe their functional 3D conformation states. Owing to the high sensitivity of differential THz-TDS, it was successfully used to sense the minute change of biological cell monolayers. The results point to a new way for biosensing applications via differential THz-TDS. As a powerful sensing technique, THz spectroscopy will continue to make profound contribution to the understanding of basic physics, chemistry and biology problems, as well as to the technological applications in chemical and biomedicine sensing areas.

  9. Microbiological, biological, and chemical weapons of warfare and terrorism.

    PubMed

    Greenfield, Ronald A; Brown, Brent R; Hutchins, James B; Iandolo, John J; Jackson, Rhett; Slater, Leonard N; Bronze, Michael S

    2002-06-01

    Microbiological, biological, and chemical toxins have been employed in warfare and in terrorist attacks. In this era, it is imperative that health care providers are familiar with illnesses caused by these agents. Botulinum toxin produces a descending flaccid paralysis. Staphylococcal enterotoxin B produces a syndrome of fever, nausea, and diarrhea and may produce a pulmonary syndrome if aerosolized. Clostridium perfringens epsilon-toxin could possibly be aerosolized to produce acute pulmonary edema. Ricin intoxication can manifest as gastrointestinal hemorrhage after ingestion, severe muscle necrosis after intramuscular injection, and acute pulmonary disease after inhalation. Nerve agents inhibit acetylcholinesterase and thus produce symptoms of increased cholinergic activity. Ammonia, chlorine, vinyl chloride, phosgene, sulfur dioxide, and nitrogen dioxide, tear gas, and zinc chloride primarily injure the upper respiratory tract and the lungs. Sulfur mustard (and nitrogen mustard) are vesicant and alkylating agents. Cyanide poisoning ranges from sudden-onset headache and drowsiness to severe hypoxemia, cardiovascular collapse, and death. Health care providers should be familiar with the medical consequences of toxin exposure, and understand the pathophysiology and management of resulting illness.

  10. High-valent iron in chemical and biological oxidations.

    PubMed

    Groves, John T

    2006-04-01

    Various aspects of the reactivity of iron(IV) in chemical and biological systems are reviewed. Accumulated evidence shows that the ferryl species [Fe(IV)O](2+) can be formed under a variety of conditions including those related to the ferrous ion-hydrogen peroxide system known as Fenton's reagent. Early evidence that such a species could hydroxylate typical aliphatic C-H bonds included regioselectivities and stereospecificities for cyclohexanol hydroxylation that could not be accounted for by a freely diffusing hydroxyl radical. Iron(IV) porphyrin complexes are also found in the catalytic cycles of cytochrome P450 and chloroperoxidase. Model oxo-iron(IV) porphyrin complexes have shown reactivity similar to the proposed enzymatic intermediates. Mechanistic studies using mechanistically diagnostic substrates have implicated a radical rebound scenario for aliphatic hydroxylation by cytochrome P450. Likewise, several non-heme diiron hydroxylases, AlkB (Omega-hydroxylase), sMMO (soluble methane monooxygenase), XylM (xylene monooxygenase) and T4moH (toluene monooxygenase) all show clear indications of radical rearranged products indicating that the oxygen rebound pathway is a ubiquitous mechanism for hydrocarbon oxygenation by both heme and non-heme iron enzymes.

  11. [Chemical composition and biological quality of defatted hazelnut flour].

    PubMed

    Villarroel, M; Biolley, E; Schneeberger, R; Ballester, D; Santibáñez, S

    1989-06-01

    The results of the chemical composition and biological quality of deffated hazel nut flour are shown. The samples analyzed contained significant amounts of proteins (19%) comparable to legume flour, higher than cereals and lower than deffated oleaginous flours. The oil extracted from the seed was analyzed and the average results obtained were the following: Refraction index, 1.47; saponification No. 184.8; iodine No. 85.0. The average composition of the fatty acids obtained by gas liquid chromatography was: Palmitic acid 2.3% Palmitoleic acid 37.0% Stearic acid 0.5% Oleic acid 39.5% Linoleic acid 6.9% Linolenic acid 1.1% Eicosanoic acid 2.3% Eicosaenoic acid 4.6% Docosenoic acid 3.4% Tetraeicosanoic acid 0.3% These results indicate a good-quality oil due to the low content of linolenic acid. The nutritive value of the deffated meal measured in the rats gave a net protein ratio (NPR) of 3.58, lower than the corresponding casein value (4.10). The true protein digestibility measured in the rat gave a value of 7.3%, compared to 95% for casein. The amounts of iron and phosphorous are comparatively lower than those reported for rape-seed meal and sunflower meal.

  12. Pereskia aculeata Muller (Cactaceae) Leaves: Chemical Composition and Biological Activities.

    PubMed

    Souza, Lucèia Fàtima; Caputo, Lucia; Inchausti De Barros, Ingrid Bergman; Fratianni, Florinda; Nazzaro, Filomena; De Feo, Vincenzo

    2016-09-03

    The aims of this work were to study the chemical composition of the essential oil from the leaves of Pereskia aculeata and to evaluate some biological activities of three leaf extracts. The phenolic content, antioxidant activity, and in vitro antimicrobial and antifungal activities were determined. The methanol extract showed antioxidant activity (EC50 7.09 mg/mL) and high polyphenols content (15.04 ± 0.31 mg gallic acid equivalents (GAE)/g). The petroleum ether extract exhibited potent antibacterial activity against Escherichia coli, whereas the chloroform extract showed inhibitory activity against Bacillus cereus and Staphylococcus aureus. The petroleum ether and methanol extracts were more effective in inhibiting the growth of Aspergillus versicolor. The possible cytotoxicity of extracts on neuroblastoma SH-SY5Y cancer cell line and the influence on adenylate cyclase (ADCY) expression was also studied. P. aculeata chloroform extract showed antiproliferative activity with an IC50 value of 262.83 µg/mL. Treatments of SH-SY5Y neuroblastoma cells with 100 µg/mL of methanol extract significantly reduced ADCY1 expression.

  13. Pereskia aculeata Muller (Cactaceae) Leaves: Chemical Composition and Biological Activities

    PubMed Central

    Souza, Lucèia Fàtima; Caputo, Lucia; Inchausti De Barros, Ingrid Bergman; Fratianni, Florinda; Nazzaro, Filomena; De Feo, Vincenzo

    2016-01-01

    The aims of this work were to study the chemical composition of the essential oil from the leaves of Pereskia aculeata and to evaluate some biological activities of three leaf extracts. The phenolic content, antioxidant activity, and in vitro antimicrobial and antifungal activities were determined. The methanol extract showed antioxidant activity (EC50 7.09 mg/mL) and high polyphenols content (15.04 ± 0.31 mg gallic acid equivalents (GAE)/g). The petroleum ether extract exhibited potent antibacterial activity against Escherichia coli, whereas the chloroform extract showed inhibitory activity against Bacillus cereus and Staphylococcus aureus. The petroleum ether and methanol extracts were more effective in inhibiting the growth of Aspergillus versicolor. The possible cytotoxicity of extracts on neuroblastoma SH-SY5Y cancer cell line and the influence on adenylate cyclase (ADCY) expression was also studied. P. aculeata chloroform extract showed antiproliferative activity with an IC50 value of 262.83 µg/mL. Treatments of SH-SY5Y neuroblastoma cells with 100 µg/mL of methanol extract significantly reduced ADCY1 expression. PMID:27598154

  14. Stability and its manifestation in the chemical and biological worlds.

    PubMed

    Pascal, Robert; Pross, Addy

    2015-11-21

    Bridging between the phenomenologically distinct biological and physical worlds has been a major scientific challenge since Boltzmann's probabilistic formulation of the second law of thermodynamics. In this review we summarize our recent theoretical attempts to bridge that divide through analysis of the thermodynamic-kinetic interplay in chemical processes and the manner in which that interplay impacts on material stability. Key findings are that the term 'stability' manifests two facets - time and energy - and that stability's time facet, expressed as persistence, is more general than its energy facet. That idea, together with the proposed existence of a logical law of nature, the persistence principle, leads to the mathematically-based insight that stability can come about through either Boltzmann's probabilistic considerations or Malthusian kinetics. Two mathematically-based forms of material persistence then lead directly to the physical likelihood of two material forms, animate and inanimate. Significantly, the incorporation of kinetic considerations into the stability concept appears to bring us closer to enabling two of the central theories in science - the second law of thermodynamics and Darwin's theory of evolution - to be reconciled within a single conceptual framework.

  15. [Nuclear, radiological, biological, and chemical dangers and risks].

    PubMed

    Maillard, Stéphane

    2008-01-01

    In contrast to military conflicts natural events, industrial disasters as well as terror attacks can surprise our society without warning. In all these events nuclear, radiological, biological or chemical dangers can be involved as well. The acute or retarded health effects on the public, first responders and society are well known. The psychological strain and disconcertion have also to be considered as well. Conditions to respond to these events with success are the early recognition and introduction of appropriate immediate measures. The early recognition is as such important because these events don't only have to start with an explosion. The early recognition should maybe base on the delayed appearance of atypical symptoms or with the increase of rare illnesses. The response to some incidence will inevitable includes drastical safety precautions such as evacuations, limitations of passenger traffic or food consumption. Precautions will only be carried out if they are understood by the public. Objective information and sensiblisation of the public and all concerned by this matter is crucial; without minimization or paranoia.

  16. Chemical and biological characterisation of nutraceutical compounds of broccoli.

    PubMed

    Moreno, D A; Carvajal, M; López-Berenguer, C; García-Viguera, C

    2006-08-28

    People's diet offers a greater and more diverse group of plant bioactives than do drugs, and they often do not realise that many drugs are derived from the compounds originally discovered in plant foods. Numerous epidemiological studies indicate that Brassica vegetables in general, and broccoli in particular, protect humans against cancer since they are rich sources of glucosinolates as well as possessing a high content of flavonoids, vitamins and mineral nutrients. One unusual phytotherapeutic role of broccoli is for skin diseases--the juice of the leaves is used to treat warts. However, the main use of broccoli stems from its health-promoting properties. Some criteria have been proposed to evaluate the possibilities of developing new "functional foods" to reduce the risk of specific cancers; largely in broccoli, which is associated with cancer protection. Processing conditions, transport, domestic cooking, etc., affect the health-promoting properties of broccoli and these have been widely studied. This review makes an in-depth study of the chemical and biological characterization of the phytochemicals of broccoli and the effects on the bioactive composition of broccoli.

  17. Chemical, biological, and immunochemical properties of the Chlamydia psittaci lipopolysaccharide.

    PubMed Central

    Brade, L; Schramek, S; Schade, U; Brade, H

    1986-01-01

    The lipopolysaccharide (LPS) of Chlamydia psittaci was extracted from yolk sac-grown elementary bodies, purified, and characterized chemically, immunochemically, and biologically. The LPS contained D-galactosamine, D-glucosamine, phosphorus, long-chain fatty acids, and 3-deoxy-D-manno-2-octulosonic acid in the molar ratio of approximately 1:2:2:6:5. The antigenic properties of the isolated LPS were compared with those of the LPS from Chlamydia trachomatis and Salmonella minnesota Re by the passive hemolysis and passive hemolysis inhibition tests, absorption, hydrolysis kinetics, and Western blot analysis with rabbit polyclonal antisera against chlamydiae and with a mouse monoclonal antibody recognizing a genus-specific epitope of chlamydial LPS. Two antigenic determinants were identified, one of which was chlamydia specific and the other of which was cross-reactive with Re LPS. Both determinants were destroyed during acid hydrolysis, whereby a third antigen specificity was exposed which was indistinguishable from the lipid A antigenicity. In rabbit polyclonal antisera prepared against Formalin-killed elementary bodies or detergent-solubilized membranes, two antibody specificities were differentiated. One of these was chlamydia specific, and the other was cross-reactive with Re LPS. The LPS of C. psittaci was inactive within typical endotoxin parameters (lethal toxicity, pyrogenicity, local Shwartzman reactivity); it was, however, active in some in vitro assays, such as those testing for mouse B-cell mitogenicity and the induction of prostaglandin E2 in mouse peritoneal macrophages. Images PMID:3770953

  18. Dissolved organic matter (DOM) and inorganic ions in a central Himalayan glacier— Insights into chemical composition and atmospheric sources

    NASA Astrophysics Data System (ADS)

    Xu, J.; Zhang, Q.; Li, X.; Xiao, C.; Ren, J.; Qin, D.

    2012-12-01

    Glaciers in the Himalayas are important water resource for many prominent Asian rivers. Recent years, these glaciers have being experiencing serious shrinkage and arousing widely concern. It has been proved that the impurities in the glacier from atmospheric sources, such as black carbon (BC) and dust, have made a significant contribution to decrease the albedo of glacier surface and accelerating the snow/glacier melting. Researches have also shown that aerosol from south Asia is an important contribution to this impurity in the Himalayan glaciers but the sources are poorly identified. By examining chemical composition in snow samples of Himalayan glacier, it is possible to determine the chemical characteristics and aerosol sources. During spring 2010, a 1-meter snow pit samples were collected from Jiemayangzong glacier in central Himalayas. Dissolved materials are analyzed using an ion chromatograph (IC), a total organic carbon (TOC) analyzer and a high resolution time-of-flight aerosol mass spectrometer (HR-AMS). The inorganic ions varied seasonally, dated from spring 2009 to spring 2010 based on the oxygen isotope. The concentrations of dissolved materials are high during winter-spring and low during summer monsoon period with average chemical composition dominated by organics (54.6%), NO3- (13.7%), SO42- (8.4%), NH4+ (9.5%) and Ca2+ (8.9%). The HR-AMS measurements allow for a direct analysis on DOM. The results show that DOM is composed mainly of oxygenated species with average oxygen-to-carbon (O/C) ratio of 0.69 (± 0.11) during winter-spring periods. DOM is less oxygenated species with O/C ratio of 0.31 (± 0.11) during summer monsoon period. Positive matrix factorization (PMF) of the high resolution mass spectra of DOM identifies a hydrocarbon-like component (denoted as HOA) and two oxygenated components (denoted as OOA and BBOA, respectively). The HOA component mainly corresponds to primary organic matter deposited during summer period accounting for 10

  19. Formation of "Chemically Pure" Magnetite from Mg-Fe-Carbonates Implications for the Exclusively Inorganic Origin of Magnetite and Sulfides in Martian Meteorite ALH84001

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, Douglas W.; Lauer, H. V., Jr.; Morris, R. V.; Trieman, A. H.; McKay, G. A.

    2006-01-01

    Magnetite and sulfides in the black rims of carbonate globules in Martian meteorite ALH84001 have been studied extensively because of the claim by McKay et al. that they are biogenic in origin. However, exclusively inorganic (abiotic) processes are able to account for the occurrence of carbonate-sulfide-magnetite assemblages in the meteorite. We have previously precipitated chemically zoned and sulfide-bearing carbonate globules analogous to those in ALH84001 (at less than or equal to 150 C) from multiple fluxes of variable-composition Ca-Mg-Fe-CO2-S-H2O solutions. Brief heating of precipitated globules to approx. 470 C produced magnetite and pyrrhotite within the globules by thermal decomposition of siderite and pyrite, respectively. We have also shown that morphology of magnetite formed by inorganic thermal decomposition of Fe-rich carbonate is similar to the morphology of so-called biogenic magnetite in the carbonate globules of ALH84001. Magnetite crystals in the rims of carbonate globules in ALH84001 are chemically pure [Note: "Chemically pure" is defined here as magnetite with Mg at levels comparable or lower than Mg detected by [8] in ALH84001 magnetite]. A debate continues on whether or not chemically pure magnetite can form by the thermal decomposition of mixed Mg-Fe-carbonates that have formed under abiotic conditions. Thomas-Keprta et al. argue that it is not possible to form Mg-free magnetite from Mg-Fe-carbonate based on thermodynamic data. We previously suggested that chemically pure magnetite could form by the thermal decomposition of relatively pure siderite in the outer rims of the globules. Mg-Fe-carbonates may also thermally decompose under conditions conducive for formation of chemically pure magnetite. In this paper we show through laboratory experiments that chemically pure magnetite can form by an inorganic process from mixed Mg-Fe-carbonates.

  20. Exploration of the central dogma at the interface of chemistry and biology: 2010 Yale Chemical Biology Symposium.

    PubMed

    Zhou, Alice Qinhua

    2010-09-01

    Ever since the term "central dogma" was coined in 1958, researchers have sought to control information flow from nucleic acids to proteins. Talks delivered by Drs. Anna Pyle and Hiroaki Suga at this year's Chemical Biology Symposium at Yale in May 2010 applauded recent advances in this area, at the interface between chemistry and biology.

  1. Bioavailability of nickel in man: effects of foods and chemically-defined dietary constituents on the absorption of inorganic nickel.

    PubMed

    Solomons, N W; Viteri, F; Shuler, T R; Nielsen, F H

    1982-01-01

    By serial determination of the change in plasma nickel concentration following a standard dose of 22.4 mg of nickel sulfate hexahydrate containing 5 mg of elemental nickel, the bioavailability of nickel was estimated in human subjects. Plasma nickel concentration was stable in the fasting state and after an unlabeled test meal, but after the standard dose of nickel in water was elevated 48.8, 73.0, 80.0, and 53.3 microgram/1, respectively, at hours 1, 2, 3, and 4. Plasma nickel did not rise above fasting levels when 5 mg of nickel was added to two standard meals: a typical Guatemalan meal and a North American breakfast. When 5 mg of nickel was added to five beverages-whole cow milk, coffee, tea, orange juice, and Coca Cola-the rise in plasma nickel was significantly suppressed with all but Coca Cola. Response to nickel also was suppressed in the presence of 1 g of ascorbic acid. Phytic acid in a 2:1 molar ratio with nickel, however, did not affect the rise in plasma nickel. The chelate of iron and ethylenediaminetetraacetate, NaFeEDTA, an iron-fortifying agent suggested for application in Central America, slightly but not significantly depressed plasma nickel rise at 2 hours, whereas disodium EDTA depressed plasma nickel levels significantly below the fasting nickel curve at 3 and 4 hours postdose. These studies suggest that the differential responses of inorganic nickel to distinct foods, beverages, and chemically-defined dietary constituents could be important to human nutrition.

  2. Chemical and Biological Defense Program Annual Report to Congress

    DTIC Science & Technology

    2006-03-01

    state public health systems, to expand existing biosurveillance efforts, and to fund research on medical countermeasures against potential bioterror...Detection System (JBSDS) • Joint Portal Shield • Biological Identification System (BIDS) • Dry Filter Units (DFUs) Table 2-3 Biological Defense...Detection System (BIDS) • Joint Portal Shield Network Sensor System • Automated biological remote detection and early warning capabilities

  3. Tests of Level A Suits - Protection Against Chemical and Biological Warfare Agents and Simulants: Executive Summary

    DTIC Science & Technology

    1998-06-01

    Tests of Level A Suits – Protection Against Chemical and Biological Warfare Agents and Simulants: Executive Summary Richard B. Belmonte...AND SUBTITLE Test Results of Level A Suits – Protection Against Chemical and Biological Warfare Agents and Simulants: Executive Summary 5. FUNDING...words) Twelve Level A protective suits were tested for GB and HD permeation swatch testing using modified procedures of TOP

  4. PERMANENCE OF BIOLOGICAL AND CHEMICAL WARFARE AGENTS IN MUNICIPAL SOLID WASTE LANDFILL LEACHATES

    EPA Science Inventory

    The objective of this work is to permit EPA/ORD's National Homeland Security Research Center (NHSRC) and Edgewood Chemical Biological Center to collaborate together to test the permanence of biological and chemical warfare agents in municipal solid waste landfills. Research into ...

  5. Programmable Adaptive Spectral Imagers for Mission-Specific Application in Chemical/Biological Sensing

    DTIC Science & Technology

    2006-01-01

    detection of chemical/biological agents. Extensive research into both passive remote chemical/biological sensors and active laser- based ( LIDAR ... photodetector (Fig. 1). Fig. 1. Adaptive spectrograph concept: light from a standoff spectral scene is dispersed, dynamically encoded with...the purpose. Data acquisition and processing software was developed for the control of the DMA, capturing data from the photodetectors , and for

  6. Active Metamaterial Based Terahertz Polarimeter for Spectroscopic Detection of Chemical and Biological Hazards

    DTIC Science & Technology

    2014-04-01

    Active Metamaterial Based Terahertz Polarimeter for Spectroscopic Detection of Chemical and Biological Hazards by Grace D. Metcalfe ...for Spectroscopic Detection of Chemical and Biological Hazards Grace D. Metcalfe and Michael Wraback Sensors and Electron Devices Directorate, ARL...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Grace D. Metcalfe , Michael Wraback, Richard D. Averitt, and Xin Zhang 5d. PROJECT NUMBER

  7. Detection and treatment of chemical weapons and/or biological pathogens

    DOEpatents

    Mariella Jr., Raymond P.

    2004-09-07

    A system for detection and treatment of chemical weapons and/or biological pathogens uses a detector system, an electrostatic precipitator or scrubber, a circulation system, and a control. The precipitator or scrubber is activated in response to a signal from the detector upon the detection of chemical weapons and/or biological pathogens.

  8. Phthalides: Distribution in Nature, Chemical Reactivity, Synthesis, and Biological Activity.

    PubMed

    León, Alejandra; Del-Ángel, Mayela; Ávila, José Luis; Delgado, Guillermo

    2017-01-01

    oxidation, reduction, addition, elimination, and cycloaddition reactions, and treatments with Lewis acids of (Z)-ligustilide have afforded linear dimers. Some intramolecular condensations and differentiated cyclizations of the dimeric phthalides have been carried out, providing evidences for the particular chemical reactivity of these compounds.Several structural modifications of phthalides have been carried out subjecting them to microbial transformations by different species of bacteria, fungi and algae, and these included resolutions of racemic mixtures and oxidations, among others.The [π4s + π2s] and [π2s + π2s] cycloadditions of (Z)-ligustilide for the synthesis of dimeric phthalides have been reported, and different approaches involving cyclizations, Alder-Rickert reactions, Sharpless asymmetric hydroxylations, or Grignard additions have been used for the synthesis of monomeric phthalides. The use of phthalides as building blocks for divergent oriented synthesis has been proven.Many of the naturally occurring phthalides display different biological activities including antibacterial, antifungal, insecticidal, cytotoxic, and anti-inflammatory effects, among many others, with a considerable recent research on the topic. In the case of compounds isolated from the Apiaceae, the bioactivities correlate with the traditional medicinal uses of the natural sources. Some monomeric phthalides have shown their ability to attenuate certain neurological diseases, including stroke, Alzheimer's and Parkinson's diseases.The present contribution covers the distribution of phthalides in nature and the findings in the structural diversity, chemical reactivity, biotransformations, syntheses, and bioactivity of natural and semisynthetic phthalides.

  9. Technological advancements for the detection of and protection against biological and chemical warfare agents.

    PubMed

    Eubanks, Lisa M; Dickerson, Tobin J; Janda, Kim D

    2007-03-01

    There is a growing need for technological advancements to combat agents of chemical and biological warfare, particularly in the context of the deliberate use of a chemical and/or biological warfare agent by a terrorist organization. In this tutorial review, we describe methods that have been developed both for the specific detection of biological and chemical warfare agents in a field setting, as well as potential therapeutic approaches for treating exposure to these toxic species. In particular, nerve agents are described as a typical chemical warfare agent, and the two potent biothreat agents, anthrax and botulinum neurotoxin, are used as illustrative examples of potent weapons for which countermeasures are urgently needed.

  10. RESEARCH TOWARD THE DEVELOPMENT OF A BIOLOGICALLY BASED DOSE RESPONSE ASSESSMENT FOR INORGANIC ARSENIC CARCINOGENICITY: A PROGRESS REPORT

    EPA Science Inventory

    Cancer risk assessments for inorganic arsenic have been based on human epidemiological data, assuming a linear dose-response below the range of observation of tumors. Part of the reason for the continued use of the linear approach in arsenic risk assessments is the lack of an ad...

  11. In situ measurement of the infrared absorption and extinction of chemical and biologically derived aerosols using flow-through photoacoustics

    NASA Astrophysics Data System (ADS)

    Gurton, Kristan P.; Dahmani, Rachid; Ligon, David; Bronk, Burt V.

    2005-07-01

    In an effort to establish a more reliable set of optical cross sections for a variety of chemical and biological aerosol simulants, we have developed a flow-through photoacoustic system that is capable of measuring absolute, mass-normalized extinction and absorption cross sections. By employing a flow-through design we avoid issues associated with closed aerosol photoacoustic systems and improve sensitivity. Although the results shown here were obtained for the tunable CO2 laser waveband region, i.e., 9.20-10.80 μm, application to other wavelengths is easily achievable. The aerosols considered are categorized as biological, chemical, and inorganic in origin, i.e., Bacillus atrophaeus endospores, dimethicone silicone oil (SF-96 grade 50), and kaolin clay powder (alumina and silicate), respectively. Results compare well with spectral extinction measured previously by Fourier-transform infrared spectroscopy. Comparisons with Mie theory calculations based on previously published complex indices of refraction and measured size distributions are also presented.

  12. Carbon Nanostructure-Based Field-Effect Transistors for Label-Free Chemical/Biological Sensors

    PubMed Central

    Hu, PingAn; Zhang, Jia; Li, Le; Wang, Zhenlong; O’Neill, William; Estrela, Pedro

    2010-01-01

    Over the past decade, electrical detection of chemical and biological species using novel nanostructure-based devices has attracted significant attention for chemical, genomics, biomedical diagnostics, and drug discovery applications. The use of nanostructured devices in chemical/biological sensors in place of conventional sensing technologies has advantages of high sensitivity, low decreased energy consumption and potentially highly miniaturized integration. Owing to their particular structure, excellent electrical properties and high chemical stability, carbon nanotube and graphene based electrical devices have been widely developed for high performance label-free chemical/biological sensors. Here, we review the latest developments of carbon nanostructure-based transistor sensors in ultrasensitive detection of chemical/biological entities, such as poisonous gases, nucleic acids, proteins and cells. PMID:22399927

  13. Chemical characterization of the inorganic fraction of aerosols and mechanisms of the neutralization of atmospheric acidity in Athens, Greece

    NASA Astrophysics Data System (ADS)

    Karageorgos, E. T.; Rapsomanikis, S.

    2007-06-01

    The PM10 mass concentration levels and inorganic chemical composition were determined on 12-h resolution sampling during August 2003 and March 2004, in the centre of Athens, Greece. The August 2003 campaign mean PM10 mass concentration, obtained by Beta Attenuation at 5 m above ground in Athinas Street, was 56 μg m-3 while the corresponding value for March 2004 was 92 μg m-3. In both campaigns the E.U. imposed daily limit of 50 μg m-3 was exceeded on several days. During the March campaign, in Athinas Street, additionally obtained DSFU-PM10 (PM10-2.5+PM2.5) gravimetric mass concentrations (mean: 121 μg m-3) in the "breathing zone", at 1.5 m above ground were significantly higher compared to the respective mean PM10 mass concentrations obtained by the same method at 25 m above ground, in a second site (AEDA; mean: 86 μg m-3) also in the centre of the city. The above findings suggest that, for a realistic estimation of the exposure of citizens to particulate matter, PM10 sampling in the "breathing zone" (1.5-3 m above ground) is necessary. Such data are presented for the first time for the centre of Athens. In both campaigns, calcium was found to be the predominant component of the coarse fraction while crust-related aluminosilicates and iron were the other major components. The above elements constitute the most important components of the fine fraction, together with the predominant sulphur. All toxic metals were found in concentrations below the established air quality limits, and most of them in lower concentrations compared to older studies. Lead in particular, appeared mostly in the fine fraction and in very low concentrations compared to studies dating more than a decade back. The predominant ions of the coarse fraction have been found to be Ca2+, NO3-, Na+ and Cl-, while SO42-, Ca2+ and NH4+ were the major ionic components of the fine fraction. In the fine particles, a low molar ratio of NH4+/SO42- indicated an ammonium-poor ambient air, and together

  14. Tests of Level B Suits - Protection Against Chemical and Biological Warfare Agents and Simulants: Executive Summary

    DTIC Science & Technology

    1999-04-01

    Tests of Level B Suits – Protection Against Chemical and Biological Warfare Agents and Simulants: Executive Summary Robert S. Lindsay April...Final; Jan 98 – Jun 98 4. TITLE AND SUBTITLE Tests of Level B Suits – Protection Against Chemical and Biological Warfare Agents and Simulants...Occupational Safety and Health Level B∗ suit designs were tested to assess their capability to protect in a chemical warfare agent

  15. Physical, chemical, and biological data for four wetland habitats in Canaan Valley, West Virginia

    USGS Publications Warehouse

    Chambers, D.B.

    1996-01-01

    This report contains data collected during 1992 as part of a project designed to identify microenvironmental factors affecting rates of denitrification in wetlands in Canaan Valley, West Virginia. Four wetland habitats were selected for the study--a moss-lichen wetland, a persistent emergent wetland, a scrub-shrub wetland, and a riverine wetland. Physical, chemical, and biological characteristics of each habitat were determined by field measurements and laboratory analyses. Samples were collected in March, June, August, and October. Sediment pH, temperature, and oxidation-reduction potential were measured in the field. Sediment samples were analyzed for concentrations of calcium, sodium, magnesium, potassium, nitrate and nitrite, ammonia, ammonia plus organic nitrogen, phosphorus, inorganic carbon, and total carbon. The most probable number of denitrifying bacteria was determined by a multiple-tube test. The dominant plant species were identified by plant-community analysis. The moss-lichen wetland was characterized by low pH (3.4 to 5.0) and small populations of denitrifying bacteria (70 to 400 per gram of wet soil). The scrub-shrub wetland was also acidic (pH 4.0 to 5.0), but supported larger numbers of denitrifying bacteria (510 to 11,000 per gram of wet soil). The number of denitrifying bacteria in the persistent emergent wetland exceeded 1,000,000 per gram of wet soil in early summer and pH in this habitat was higher (5.1 to 6.6) than in the bogs. Riverine wetland pH ranged from 5.4 to 6.9, and the number of denitrifying bacteria ranged from 200 to 11,000 per gram of wet soil.

  16. Inhibition of chemical dose in biological phosphorus and nitrogen removal in simultaneous chemical precipitation for phosphorus removal.

    PubMed

    Liu, Yanchen; Shi, Hanchang; Li, Wenlin; Hou, Yanling; He, Miao

    2011-03-01

    A study on the influence of chemical dosing on biological phosphorus and nitrogen removal was carried out through batch experimental tests by lab-scale and a full-scale wastewater treatment plant (employing a typical anaerobic-anoxic-oxic treatment). Results indicated that the inhibition of aluminum salt on biological phosphorus release and uptake processes is significant, as well as the inhibition of aluminum salt on Ammonia-Oxidizing Bacteria (AOB) is dominantly observed in the nitrification process and is recoverability. The inhibition of iron salt in biological phosphorus and nitrogen removal is weak, and only the inhibition of iron salt on phosphorus release at anaerobic periods emerge under large dosing. Evidence shows persistent inhibition from the accumulation of chemical doses in sludge mass. Intermittent chemical dosing proves recommendable for simultaneous chemical phosphorus removal.

  17. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1997-11-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  18. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). NewSearch

    SciTech Connect

    Not Available

    1994-10-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology. (Contains 250 citations and includes a subject term index and title list.)

  19. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-10-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  20. Chemical and biological warfare: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-09-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  1. Chemical and biological warfare: General studies. (Latest citations from the NTIS Bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations concerning federally sponsored and conducted studies into chemical and biological warfare operations and planning. These studies cover areas not addressed in other parts of this series. The topics include production and storage of agents, delivery techniques, training, military and civil defense, general planning studies, psychological reactions to chemical warfare, evaluations of materials exposed to chemical agents, and studies on banning or limiting chemical warfare. Other published searches in this series on chemical warfare cover detection and warning, defoliants, protection, and biological studies, including chemistry and toxicology. (Contains 250 citations and includes a subject term index and title list.)

  2. Chemical and biological sensing with organic thin-film transistors

    NASA Astrophysics Data System (ADS)

    Mabeck, Jeffrey Todd

    Organic thin-film transistors (OTFTs) offer a great deal of promise for applications in chemical and biological sensing where there is a demand for small, portable, and inexpensive sensors. OTFTs have many advantages over other types of sensors, including low-cost fabrication, straightforward miniaturization, simple instrumentation, and inherent signal amplification. This dissertation examines two distinct types of OTFTs: organic field-effect transistors (OFETs) based on pentacene, and organic electrochemical transistors (OECTs) based on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The bulk of the previous work on sensing with OFETs has focused on gas sensing, and this dissertation contributes to this body of work by briefly treating the large, reversible response of pentacene OFETs to humidity. However, there are many applications where the analyte of interest must be detected in an aqueous environment rather than a gaseous environment, and very little work has been done in this area for OFETs. Therefore, the integration of pentacene OFETs with microfluidics is treated in detail. Using poly(dimethylsiloxane) (PDMS) microfluidic channels to confine aqueous solutions over the active region of pentacene transistors, it is demonstrated that the current-voltage characteristics remain stable under aqueous flow with a decrease in mobility of ˜30% compared to its value when dry. The operation of PEDOT:PSS transistors is also treated in detail. It is demonstrated that their transistor behavior cannot be attributed solely to a field effect and that ion motion is key to the switching mechanism. It is also demonstrated that simple glucose sensors based on PEDOT:PSS OECTs are sensitive to low glucose concentrations below 1 mM, therefore showing promise for potential application in the field of noninvasive glucose monitoring for diabetic patients using saliva rather than blood samples. Furthermore, a novel microfluidic gating technique has been

  3. Chemical and Biological Sensors Based on Organic Electrochemical Transistors

    NASA Astrophysics Data System (ADS)

    Lin, Peng

    Organic thin film transistors (OTFTs) have been explored for sensing applications for several decades due to their many advantages like easy fabrication, low cost, flexibility, and biocompatibility. Among these OTFTs, organic electrochemical transistors (OECTs) have attracted a great deal of interest in recent years since the devices can operate stably in aqueous environment with relatively low working voltages and are suitable for applications in chemical and biological sensing. In this thesis, ion-sensitive properties of OECTs based on poly(3,4- ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) have been systematically studied. It was found that the gate electrode played an important role on the ion-sensitive properties of OECTs. For the devices with Ag/AgCl gate electrode, Nernstian relationships between the shift of gate voltage and the concentrations of cations were obtained. For the devices with Pt and Au gate electrodes, the ion sensitivities were higher than that given by Nernst equation, which could be attributed to the interface between the metal gate electrode and the electrolyte. Moreover, OECTs based on PEDOT:PSS were integrated into flexible microfluidic systems. Then a novel label-free DNA sensor was developed, in which single-stranded DNA probes were immobilized on the surface of Au gate electrode. These devices successfully detected complementary DNA targets at concentrations as low as 1 nM. The detection limit was also extended to 10 pM by pulse-enhanced hybridization process of DNA. OECTs based on PEDOT:PSS were also exploited as cell-based biosensors. Human esophageal squamous epithelial cancer cell lines (KYSE30) and fibroblast cell lines (HFFI) were successfully grown on the surface of PEDOT:PSS film. Then the devices were used for in-vitro monitoring cell activities when the living cells were treated by trypsin and an anti-cancer drug, retinoic acid. It was found that the devices were sensitive to the change of surface charge

  4. Suitability of Gray Water for Hydroponic Crop Production Following Biological and Physical Chemical and Biological Subsystems

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.; Harper, Lynn D.; Wignarajah, Kanapathipillai; Greene, Catherine

    1994-01-01

    The water present in waste streams from a human habitat must be recycled in Controlled Ecological Life Support Systems (CELSS) to limit resupply needs and attain self-sufficiency. Plants play an important role in providing food, regenerating air, and producing purified water via transpiration. However, we have shown that the surfactants present in hygiene waste water have acute toxic effects on plant growth (Bubenheim et al. 1994; Greene et al., 1994). These phytotoxic affects can be mitigated by allowing the microbial population on the root surface to degrade the surfactant, however, a significant suppression (several days) in crop performance is experienced prior to reaching sub-toxic surfactant levels and plant recovery. An effective alternative is to stabilize the microbial population responsible for degradation of the surfactant on an aerobic bioreactor and process the waste water prior to utilization in the hydroponic solution (Wisniewski and Bubenheim, 1993). A sensitive bioassay indicates that the surfactant phytotoxicity is suppressed by more than 90% within 5 hours of introduction of the gray water to the bioreactor; processing for more than 12 hours degrades more than 99% of the phytotoxin. Vapor Compression Distillation (VCD) is a physical / chemical method for water purification which employees sequential distillation steps to separate water from solids and to volatilize contaminants. The solids from the waste water are concentrated in a brine and the pure product water (70 - 90% of the total waste water volume depending on operating conditions) retains non of the phytotoxic effects. Results of the bioassay were used to guide evaluations of the suitability of recovered gray water following biological and VCD processing for hydroponic lettuce production in controlled environments. Lettuce crops were grown for 28 days with 100% of the input water supplied with recovered water from the biological processor or VCD. When compared with the growth of plants

  5. Potential Military Chemical/Biological Agents and Compounds

    DTIC Science & Technology

    2005-01-01

    toxins, bioregulators, or prions. (1) Pathogens. Pathogens are disease-producing microorganisms,6 such as bacteria , rickettsiae , or viruses...disability. Potential biological antipersonnel agents include toxins, bacteria , rickettsiae , viruses, and toxins. (2) Antianimal. Biological...microorganisms such as pathogens (which include disease-causing bacteria , rickettsiae , and viruses) and toxins. NOTES: 1. See Table IV-1 (page IV-2) for the

  6. Which chemicals drive biological effects in wastewater and recycled water?

    PubMed

    Tang, Janet Y M; Busetti, Francesco; Charrois, Jeffrey W A; Escher, Beate I

    2014-09-01

    Removal of organic micropollutants from wastewater during secondary treatment followed by reverse osmosis and UV disinfection was evaluated by a combination of four in-vitro cell-based bioassays and chemical analysis of 299 organic compounds. Concentrations detected in recycled water were below the Australian Guidelines for Water Recycling. Thus the detected chemicals were considered not to pose any health risk. The detected pesticides in the wastewater treatment plant effluent and partially advanced treated water explained all observed effects on photosynthesis inhibition. In contrast, mixture toxicity experiments with designed mixtures containing all detected chemicals at their measured concentrations demonstrated that the known chemicals explained less than 3% of the observed cytotoxicity and less than 1% of the oxidative stress response. Pesticides followed by pharmaceuticals and personal care products dominated the observed mixture effects. The detected chemicals were not related to the observed genotoxicity. The large proportion of unknown toxicity calls for effect monitoring complementary to chemical monitoring.

  7. Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: implications for reach scales and beyond

    USGS Publications Warehouse

    Bohlke, Johnkarl F.; Tobias, Craig

    2011-01-01

    Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, d13C-DIC, dissolved oxygen (O2), d18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air–water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air–water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

  8. Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: Implications for reach scales and beyond

    USGS Publications Warehouse

    Tobias, C.; Böhlke, J.K.

    2011-01-01

    Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, ??13C-DIC, dissolved oxygen (O2), ??18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air-water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air-water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

  9. Department of Defense Joint Chemical and Biological Defense Program 2009 Annual Report to Congress

    DTIC Science & Technology

    2009-03-27

    develop a complimentary handheld analytic device to accurately identify chemical agents. Medical Biological Defense Research Biological defense...and biologics, and clearance of medical devices is required before any drug, vaccine, biologic, or device can be used by or on a Warfighter...Implemented a new drug discovery and development capability that has streamlined the acquisition process for safe • and effective medical products provided

  10. Integrating Biological and Chemical Data for Hepatotoxicity Prediction (SOT)

    EPA Science Inventory

    The U.S. EPA ToxCastTM program is screening thousands of environmental chemicals for bioactivity using hundreds of high-throughput in vitro assays to build predictive models of toxicity. A set of 677 chemicals were represented by 711 bioactivity descriptors (from ToxCast assays),...

  11. Integrated Model of Chemical Perturbations of a Biological ...

    EPA Pesticide Factsheets

    We demonstrate a computational network model that integrates 18 in vitro, high-throughput screening assays measuring estrogen receptor (ER) binding, dimerization, chromatin binding, transcriptional activation and ER-dependent cell proliferation. The network model uses activity patterns across the in vitro assays to predict whether a chemical is an ER agonist or antagonist, or is otherwise influencing the assays through a manner dependent on the physics and chemistry of the technology platform (“”assay interference”). The method is applied to a library of 1812 commercial and environmental chemicals, including 45 ER positive and negative reference chemicals. Among the reference chemicals, the network model correctly identified the agonists and antagonists with the exception of very weak compounds whose activity was outside the concentration range tested. The model agonist score also correlated with the expected potency class of the active reference chemicals. Of the 1812 chemicals evaluated, 52 (2.8%) were predicted to be strongly ER active in agonist or antagonist mode. This dataset and model were also used to begin a systematic investigation of assay interference. The most prominent cause of false-positive activity (activity in an assay that is likely not due to interaction of the chemical with ER) is cytotoxicity. The model provides the ability to prioritize a large set of important environmental chemicals with human exposure potential for additional in v

  12. Counter-Chemical, Biological, Radiological, and Nuclear Operations

    DTIC Science & Technology

    2007-01-26

    Present. [Order from DTIC-E, 8725 John J. Kingman Road, Suite 0944, Ft Belvoir, VA 22060-6218.] Douglas, Joseph, and Livingstone, Neil , America the...Harris, Sheldon H ., Factories of Death: Japanese Biological Warfare, 1932-45, and the American Cover-up (Routledge). 1994. Hayes, Peter L...Biological Warfare (Office of Surgeon General, Borden Institute). 1997. Sloan, Steven, Beating International Terrorism (Air University Press). 1986

  13. Essential Oils from Thyme (Thymus vulgaris): Chemical Composition and Biological Effects in Mouse Model.

    PubMed

    Vetvicka, Vaclav; Vetvickova, Jana

    2016-12-01

    Thymus species are popular spices and contain volatile oils as main chemical constituents. Recently, plant-derived essential oils are gaining significant attention due to their significant biological activities. Seven different thymus-derived essential oils were compared in our study. First, we focused on their chemical composition, which was followed up by testing their effects on phagocytosis, cytokine production, chemotaxis, edema inhibition, and liver protection. We found limited biological activities among tested oils, with no correlation between composition and biological effects. Similarly, no oils were effective in every reaction. Based on our data, the tested biological use of these essential oils is questionable.

  14. Selectivity on-target of bromodomain chemical probes by structure-guided medicinal chemistry and chemical biology.

    PubMed

    Galdeano, Carles; Ciulli, Alessio

    2016-09-01

    Targeting epigenetic proteins is a rapidly growing area for medicinal chemistry and drug discovery. Recent years have seen an explosion of interest in developing small molecules binding to bromodomains, the readers of acetyl-lysine modifications. A plethora of co-crystal structures has motivated focused fragment-based design and optimization programs within both industry and academia. These efforts have yielded several compounds entering the clinic, and many more are increasingly being used as chemical probes to interrogate bromodomain biology. High selectivity of chemical probes is necessary to ensure biological activity is due to an on-target effect. Here, we review the state-of-the-art of bromodomain-targeting compounds, focusing on the structural basis for their on-target selectivity or lack thereof. We also highlight chemical biology approaches to enhance on-target selectivity.

  15. Selectivity on-target of bromodomain chemical probes by structure-guided medicinal chemistry and chemical biology

    PubMed Central

    Galdeano, Carles; Ciulli, Alessio

    2017-01-01

    Targeting epigenetic proteins is a rapidly growing area for medicinal chemistry and drug discovery. Recent years have seen an explosion of interest in developing small molecules binding to bromodomains, the readers of acetyl-lysine modifications. A plethora of co-crystal structures has motivated focused fragment-based design and optimization programs within both industry and academia. These efforts have yielded several compounds entering the clinic, and many more are increasingly being used as chemical probes to interrogate bromodomain biology. High selectivity of chemical probes is necessary to ensure biological activity is due to an on-target effect. Here, we review the state-of-the-art of bromodomain-targeting compounds, focusing on the structural basis for their on-target selectivity or lack thereof. We also highlight chemical biology approaches to enhance on-target selectivity. PMID:27193077

  16. Biological and Chemical Significance of Surface Microlayers in Aquatic Ecosystems

    ERIC Educational Resources Information Center

    Parker, B.; Barsom, G.

    1970-01-01

    Reviews methods of study, chemical composition, physical properties and ecology of surface microlayers in marine and fresh water habitats. Relates to problems of air and water pollution. Suggests areas for further research. (EB)

  17. Effects of upwelling, tides and biological processes on the inorganic carbon system of a coastal lagoon in Baja California

    NASA Astrophysics Data System (ADS)

    Ribas-Ribas, M.; Hernández-Ayón, J. M.; Camacho-Ibar, V. F.; Cabello-Pasini, A.; Mejia-Trejo, A.; Durazo, R.; Galindo-Bect, S.; Souza, A. J.; Forja, J. M.; Siqueiros-Valencia, A.

    2011-12-01

    The role of coastal lagoons and estuaries as sources or sinks of inorganic carbon in upwelling areas has not been fully understood. During the months of May-July, 2005, we studied the dissolved inorganic carbon system in a coastal lagoon of northwestern Mexico during the strongest period of upwelling events. Along the bay, different scenarios were observed for the distributions of pH, dissolved inorganic carbon (DIC) and apparent oxygen utilization (AOU) as a result of different combinations of upwelling intensity and tidal amplitude. DIC concentrations in the outer part of the bay were controlled by mixing processes. At the inner part of the bay DIC was as low as 1800 μmol kg -1, most likely due to high water residence times and seagrass CO 2 uptake. It is estimated that 85% of San Quintín Bay, at the oceanic end, acted as a source of CO 2 to the atmosphere due to the inflow of CO 2-rich upwelled waters from the neighboring ocean with high positive fluxes higher than 30 mmol C m -2 d -1. In contrast, there was a net uptake of CO 2 and HCO 3- by the seagrass bed Zostera marina in the inner part of the bay, so the pCO 2 in this zone was below the equilibrium value and slightly negative CO 2 fluxes of -6 mmol C m -2 d -1. Our positive NEP and ΔDIC values indicate that Bahía San Quintín was a net autotrophic system during the upwelling season during 2005.

  18. Prospects for improved detection of chemical, biological, radiological, and nuclear threats

    SciTech Connect

    Wuest, Craig R.; Hart, Brad; Slezak, Thomas R.

    2012-07-31

    Acquisition and use of Chemical, Biological, Radiological, and Nuclear (CBRN) weapons continue to be a major focus of concern form the security apparatus of nation states because of their potential for mass casualties when used by a determined adversary.

  19. Chemical and biological extraction of metals present in E waste: A hybrid technology.

    PubMed

    Pant, Deepak; Joshi, Deepika; Upreti, Manoj K; Kotnala, Ravindra K

    2012-05-01

    Management of metal pollution associated with E-waste is widespread across the globe. Currently used techniques for the extraction of metals from E-waste by using either chemical or biological leaching have their own limitations. Chemical leaching is much rapid and efficient but has its own environmental consequences, even the future prospects of associated nanoremediation are also uncertain. Biological leaching on the other hand is comparatively a cost effective technique but at the same moment it is time consuming and the complete recovery of the metal, alone by biological leaching is not possible in most of the cases. The current review addresses the individual issues related to chemical and biological extraction techniques and proposes a hybrid-methodology which incorporates both, along with safer chemicals and compatible microbes for better and efficient extraction of metals from the E-waste.

  20. Caenorhabditis elegans chemical biology: lessons from small molecules

    Technology Transfer Automated Retrieval System (TEKTRAN)

    How can we complement Caenorhabditis elegans genomics and proteomics with a comprehensive structural and functional annotation of its metabolome? Several lines of evidence indicate that small molecules of largely undetermined structure play important roles in C. elegans biology, including key pathw...

  1. Environmental parameters of the Tennessee River in Alabama. 2: Physical, chemical, and biological parameters. [biological and chemical effects of thermal pollution from nuclear power plants on water quality

    NASA Technical Reports Server (NTRS)

    Rosing, L. M.

    1976-01-01

    Physical, chemical and biological water quality data from five sites in the Tennessee River, two in Guntersville Reservoir and three in Wheeler Reservoir were correlated with climatological data for three annual cycles. Two of the annual cycles are for the years prior to the Browns Ferry Nuclear Power Plant operations and one is for the first 14 months of Plant operations. A comparison of the results of the annual cycles indicates that two distinct physical conditions in the reservoirs occur, one during the warm months when the reservoirs are at capacity and one during the colder winter months when the reservoirs have been drawn-down for water storage during the rainy months and for weed control. The wide variations of physical and chemical parameters to which the biological organisms are subjected on an annual basis control the biological organisms and their population levels. A comparison of the parameters of the site below the Power plant indicates that the heated effluent from the plant operating with two of the three reactors has not had any effect on the organisms at this site. Recommendations given include the development of prediction mathematical models (statistical analysis) for the physical and chemical parameters under specific climatological conditions which affect biological organisms. Tabulated data of chemical analysis of water and organism populations studied is given.

  2. Preparing for a Nightmare: USNORTHCOM’S Homeland Defense Mission Against Chemical and Biological Attack

    DTIC Science & Technology

    2014-05-15

    CONTRACT NUMBER AGAINST CHEMICAL AND BIOLOGICAL ATTACK 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...by the NWC or the Department of the Navy. 14. ABSTRACT The U.S. will be subject to future terrorist attacks and innovative violent extremists will...inadequate defenses, present a clear and present threat of attack with WMD. Chemical agents and biological pathogens, due to their availability and

  3. Biological and chemical weapons of mass destruction: updated clinical therapeutic countermeasures since 2003.

    PubMed

    Pettineo, Christopher; Aitchison, Robert; Leikin, Scott M; Vogel, Stephen N; Leikin, Jerrold B

    2009-01-01

    The objective of this article is to provide updated treatment options for bioterrorism agents. This updated synopsis includes recent clinical cases and treatment recommendations that have arisen in the last 5 years. The decontamination, treatment, and disposition of these biologic and chemical agents are presented alphabetically by agent type: biologic, chemical, and radiologic/nuclear. The information provided outlines only new treatment options since 2003.

  4. Physical, chemical, and biological data for detailed study of irrigation drainage in the Klamath Basin, California and Oregon, 1990-92

    USGS Publications Warehouse

    MacCoy, D.E.

    1994-01-01

    Physical, chemical, and biological data were collected between 1990 and 1992 as part of a detailed study by the U.S. Department of Interior of the effects of irrigation drainage on aquatic resources in the Klamath Basin of California and Oregon. Most of the sites for data collection were in and around the upper and lower sump of Tule Lake, in the Tule Lake National Wildlife Refuge, and along major drains in Lower Klamath National Wildlife Refuge. The physical and chemical data consist of particle-size determinations and concentrations of carbon, mercury, arsenic, chlorophenoxy acid, and organochlorine, organophosphate, and carbamate pesticides in bottom sediment; and concentrations of organophosphate, carbamate, and pyrethroid pesticides, major and trace inorganic constituents, nitrogen, phosphorus, and organic carbon in water. Continuous dissolved oxygen, pH, specific conduc- tance, and temperature data from selected sites in 1991 and 1992 are presented in graphical form to summarize the diel water-quality conditions. The biological data consists of concentrations of inorganic constituents and organochlorine pesticides in tissue, invertebrate and fish population surveys, fish health surveys, frog call surveys, egg shell thickness of avian eggs, and in situ and static toxicity bioassay data collected in 1991 and 1992 using aquatic bacteria, plants, invertebrates, fish, and bird species as test organisms.

  5. The Eleventh Plague: The Politics of Biological and Chemical Warfare

    NASA Astrophysics Data System (ADS)

    Kovac, Jeffrey

    1997-07-01

    Leonard A. Cole. W. H. Freeman: New York, 1997. 250 pp. ISBN 0-7167-2950-4. $22.95 hc. The Eleventh Plague begins with a recitation of the ten plagues brought down upon Egypt, part of the Passover Seder celebrated each spring by Jews all over the world. Spring is also the anniversary of the first use of chemical weapons. On April 22, 1915, German soldiers released chlorine gas from 5,739 cylinders installed along the battle line at Ypres in southeastern Belgium. Germany achieved complete surprise. The gas drifted across no man's land, causing widespread terror and creating ten thousand serious casualties and five thousand deaths. Chlorine, of course, was a poor weapon, easily neutralized, but German scientists, including future Nobel laureates Fritz Haber, Otto Hahn, and James Franck, and the German chemical industry created ever more dangerous chemical weapons, culminating with the introduction of mustard gas in 1917. Despite cries of moral outrage, the Allies countered with their own chemical weapons efforts. The eleventh plague had been unleashed.

  6. Sampling of vehicle emissions for chemical analysis and biological testing.

    PubMed Central

    Schuetzle, D

    1983-01-01

    Representative dilution tube sampling techniques for particulate and gas phase vehicle emissions are described using Teflon filter media and XAD-2 resin. More than 90% of the total gas (C8-C18) and particulate direct acting Ames assay mutagenicity (TA 98) was found in the particulate phase. The gas and particulate phase material was fractionated by HPLC into nonpolar, moderately polar and highly polar chemical fractions. The moderately polar chemical fraction of the particulates contained more than 50% of the direct acting Ames assay mutagenicity for the total extract. The concentration of oxygenated polynuclear aromatic hydrocarbons (oxy-PAH) and nitrated PAH (nitro-PAH) identified in the moderately polar particulate fractions are given. Nitro-PAH account for most of the direct-acting (TA 98) Ames assay mutagenicity in these moderately polar fractions. Reactions and kinetic expressions for chemical conversion of PAH are presented. Chemical conversion of PAH to nitro-PAH during dilution tube sampling of particulates on Teflon filters and gases on XAD-2 resin is a minor problem (representing 10-20%, on the average, of the 1-nitropyrene found in extracts) at short (46 min) sampling times, at low sampling temperatures (42 degrees C), and in diluted exhaust containing 3 ppm NO2. Particulate emissions collected from dilution tubes on filter media appear to be representative of what is emitted in the environment as based upon a comparison of highway and laboratory studies. PMID:6186484

  7. Polymeric Materials for Protection Against Chemical and Biological Contaminants

    DTIC Science & Technology

    2002-09-30

    the demand for a safe antimicrobial and deodorizing treatment, chemical methods have been proposed using as an antimicrobial component, halamines...in an organic solvent such as carbon disulfide, and a Friedei-Crafts acylation was performed utilizing acetyl chloride and the catalyst aluminum

  8. Chemical, Biological, and Radiological Contamination Survivability: Material Effects Testing

    DTIC Science & Technology

    2012-06-22

    compatibility X 23 Lubricity X 24 Solubility X 25 Melting point/boiling point X 26 Viscosity X Ph...MATERIAL PROPERTIES MATRIX AND DATA TEMPLATE. TABLE 2. CONTINUED Petroleum, Oils , and Lubricants Properties (cite method, SOP, ASTM, etc...used) Sample Name/Product Number Thermal Stability Chemical Compatibility Lubricity Solubility Melting Point/Boiling Point Viscosity

  9. Integrated assessment of oil pollution using biological monitoring and chemical fingerprinting.

    PubMed

    Lewis, Ceri; Guitart, Carlos; Pook, Chris; Scarlett, Alan; Readman, James W; Galloway, Tamara S

    2010-06-01

    A full assessment of the impact of oil and chemical spills at sea requires the identification of both the polluting chemicals and the biological effects they cause. Here, a combination of chemical fingerprinting of surface oils, tissue residue analysis, and biological effects measures was used to explore the relationship between spilled oil and biological impact following the grounding of the MSC Napoli container ship in Lyme Bay, England in January 2007. Initially, oil contamination remained restricted to a surface slick in the vicinity of the wreck, and there was no chemical evidence to link biological impairment of animals (the common limpet, Patella vulgata) on the shore adjacent to the oil spill. Secondary oil contamination associated with salvage activities in July 2007 was also assessed. Chemical analyses of aliphatic hydrocarbons and terpanes in shell swabs taken from limpet shells provided an unequivocal match with the fuel oil carried by the ship. Corresponding chemical analysis of limpet tissues revealed increased concentrations of polycyclic aromatic hydrocarbons (PAHs) dominated by phenanthrene and C1 to C3 phenanthrenes with smaller contributions from heavier molecular weight PAHs. Concurrent ecotoxicological tests indicated impairment of cellular viability (p < 0.001), reduced immune function (p < 0.001), and damage to DNA (Comet assay, p < 0.001) in these animals, whereas antioxidant defenses were elevated relative to un-oiled animals. These results illustrate the value of combining biological monitoring with chemical fingerprinting for the rapid identification of spilled oils and their sublethal impacts on biota in situ.

  10. Modeling Dispersion of Chemical-Biological Agents in Three Dimensional Living Space

    SciTech Connect

    William S. Winters

    2002-02-01

    This report documents a series of calculations designed to demonstrate Sandia's capability in modeling the dispersal of chemical and biological agents in complex three-dimensional spaces. The transport of particles representing biological agents is modeled in a single room and in several connected rooms. The influence of particle size, particle weight and injection method are studied.

  11. Incorporating Molecular and Cellular Biology into a Chemical Engineering Degree Program

    ERIC Educational Resources Information Center

    O'Connor, Kim C.

    2005-01-01

    There is a growing need for a workforce that can apply engineering principles to molecular based discovery and product development in the biological sciences. To this end, Tulane University established a degree program that incorporates molecular and cellular biology into the chemical engineering curriculum. In celebration of the tenth anniversary…

  12. Evolutionary biology and chemical geology: a timely marriage.

    PubMed

    Cintas, Pedro

    2004-07-05

    For more than 150 years natural selection has been perceived to be the overwhelming force in evolution. Only in recent decades have we obtained new insights into environmental and physicochemical factors that participate with selection in a synergic way. Far from denying Darwin's theory, such neglected factors put order to the bewildering range of genotypes and morphologies found in living organisms and, more importantly, they place evolution in a planetary context where biology, geology, and chemistry can easily be integrated.

  13. Detection of biological molecules using chemical amplification and optical sensors

    DOEpatents

    Van Antwerp, William Peter; Mastrototaro, John Joseph

    2000-01-01

    Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.

  14. Detection of biological molecules using chemical amplification and optical sensors

    DOEpatents

    Van Antwerp, William Peter; Mastrototaro, John Joseph

    2004-10-12

    Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.

  15. Detection of biological molecules using chemical amplification and optical sensors

    SciTech Connect

    Antwerp, W.P. van; Mastrototaro, J.J.

    2000-01-04

    Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.

  16. 78 FR 74218 - Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and Warfare... chemical weapons in violation of international law or lethal chemical weapons against its own nationals... the Chemical and Biological Weapons Control and Warfare Elimination Act of 1991, 22 U.S.C. 5604(a)...

  17. Terrorism: Background on Chemical, Biological, and Toxin Weapons and Options for Lessening Their Impact

    DTIC Science & Technology

    2004-12-01

    Environmental Health , Centers for Disease Control and Prevention, Emergency Room Procedures in Chemical Hazard Emergencies. A Job Aid, found online at...production; developing countermeasures through directed public health funding’ reducing public concern by enhancing public preparedness through...nor protection. Chemical, biological, and toxin weapons pose additional concerns beyond mass casualties. These weapons may contaminate the area in

  18. Deciphering Diseases and Biological Targets for Environmental Chemicals using Toxicogenomics Networks

    PubMed Central

    Audouze, Karine; Juncker, Agnieszka Sierakowska; Roque, Francisco J. S. S. A.; Krysiak-Baltyn, Konrad; Weinhold, Nils; Taboureau, Olivier; Jensen, Thomas Skøt; Brunak, Søren

    2010-01-01

    Exposure to environmental chemicals and drugs may have a negative effect on human health. A better understanding of the molecular mechanism of such compounds is needed to determine the risk. We present a high confidence human protein-protein association network built upon the integration of chemical toxicology and systems biology. This computational systems chemical biology model reveals uncharacterized connections between compounds and diseases, thus predicting which compounds may be risk factors for human health. Additionally, the network can be used to identify unexpected potential associations between chemicals and proteins. Examples are shown for chemicals associated with breast cancer, lung cancer and necrosis, and potential protein targets for di-ethylhexyl-phthalate, 2,3,7,8-tetrachlorodibenzo-p-dioxin, pirinixic acid and permethrine. The chemical-protein associations are supported through recent published studies, which illustrate the power of our approach that integrates toxicogenomics data with other data types. PMID:20502671

  19. Perforated Monolayers for Enhanced Permselectivity in Chemical Biological Barrier Membranes

    DTIC Science & Technology

    2004-12-01

    Membranes. In the 1930s, Irving Langmuir and Katherine Blodgett introduced a method for fabricating monolayer and multilayer arrays of surfactants...pass. With this goal in mind, we have been developing an ultra-thin membrane capable of blocking chemical agents, utilizing Langmuir -Blodgett (LB...order of 6 nm thick having extraordinary barrier properties, high flux, and stability. 2. Langmuir -Blodgett Films as Permeation-Selective

  20. Chemical, Biological, and Radiological (CBR) Contamination Survivability: Large Item Interiors

    DTIC Science & Technology

    2012-06-22

    transmittance, reflectance) X X X X 30 Crazing , stress, corrosion, cracking X X X X X X X X 31 Acoustic dampening X X X 32 Glass...These aspects include assessing for agent trapped in cracks , crevices, between components, in angles, and in odd shapes not easily decontaminable...both system’s chassis are chemical agent-resistant coating (CARC)-painted steel , or both systems are bulldozers with one being larger than the other

  1. Interfacing ?Soft? and ?Hard? Matter with Exquisite Chemical Control

    SciTech Connect

    Woo, Y; Camarero, J A

    2006-01-13

    The present paper reviews the recent development of new chemical and biological technologies for the site-specific immobilization of proteins onto inorganic materials and their potential applications to the fields of micro and nanotechnology.

  2. Detection of biological molecules using chemical amplification and optical sensors

    DOEpatents

    Van Antwerp, William Peter; Mastrototaro, John Joseph

    2001-01-01

    Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal. Specifically, the analyte transducer immobilized in a polymeric matrix can be a boronic acid moiety.

  3. The biological exposure indices: a key component in protecting workers from toxic chemicals.

    PubMed Central

    Morgan, M S

    1997-01-01

    Biological monitoring of exposure to chemicals in the workplace is an important component of exposure assessment and prevention of adverse health effects. It should be employed in conjunction with ambient air monitoring to provide information on the absorbed dose of a chemical agent and the effect of all routes of exposure. Judgments regarding the acceptable level of a chemical or its metabolite in biological samples are facilitated by comparison to a reference value. The American Conference of Governmental Industrial Hygienists has established a series of recommended reference values called the Biological Exposure Indices (BEI). The history and characteristics of the BEI are reviewed, and their suitability for use by occupational health specialists is examined. A number of challenges and stimuli to the continued development and improvement of these reference values are described, and the impact of recent advances in macromolecular biology is assessed. PMID:9114280

  4. Procurement of a Large Area Mapping FTIR Microscope for Organic-Inorganic Interfacial Analysis in Biological Materials

    DTIC Science & Technology

    2015-12-31

    as templates for biologically inspired systems. These biological systems demonstrate the ability to control nano - and microstructural features that...Chitons. Another project, was performed in collaboration with Professor Hiroaki Imai at Keio University in Tokyo, investigates micro-and nano -features...and nano -scale morphological features that may contribute to the bulk mechanical properties (Figure 3). One approach through which this will be

  5. Biological monitoring of occupational exposure to toxic chemicals. Collection, processing, and storage of specimens

    SciTech Connect

    Aitio, A.; Jaervisalo, J.

    1985-03-01

    Exposure to at least 100 different chemicals may be estimated on an individual basis from their concentrations in blood or urine. The present document reviews sources of error in the collection, processing and storage of specimens for this biological monitoring. Physiological factors cause variation in the concentration of chemicals in the body fluids. Distribution of water depends on posture. Exercise and meals cause changes in blood constituents. The urine output varies and, thus, the concentrations of dissolved chemicals change. Many toxic chemicals show short half times in the blood; thus, their concentrations depend on the timing of the specimen collection. Skin absorption may result in dramatically different chemical concentrations in different parts of the circulation. The stability of chemicals in the collected specimens is generally limited: chemical deterioration, adsorption, precipitation, and evaporation are the main causes of losses. For many chemicals, especially for trace elements, contamination of the specimen is the overwhelmingly most important source of error. As the range of the chemicals measured is wide, the relative importance of the sources of error is different for different chemicals. Information on most chemicals is at present very limited. Thus, before commencing a program on biological exposure monitoring, it is advisable to search the optimal conditions for specimen collection, processing, and storage.

  6. The bioartificial pancreas (BAP): Biological, chemical and engineering challenges.

    PubMed

    Iacovacci, Veronica; Ricotti, Leonardo; Menciassi, Arianna; Dario, Paolo

    2016-01-15

    The bioartificial pancreas (BAP) represents a viable solution for the treatment of type 1 diabetes (T1D). By encapsulating pancreatic cells in a semipermeable membrane to allow nutrient, insulin and glucose exchange, the side effects produced by islets and whole organ transplantation-related immunosuppressive therapy can be circumvented. Several factors, mainly related to materials properties, capsule morphology and biological environment, play a key role in optimizing BAP systems. The BAP is an extremely complex delivery system for insulin. Despite considerable efforts, in some instances meeting with limited degree of success, a BAP capable of restoring physiological pancreas functions without the need for immunosuppressive drugs and of controlling blood glucose levels especially in large animal models and a few clinical trials, does not exist. The state of the art in terms of materials, fabrication techniques and cell sources, as well as the current status of commercial devices and clinical trials, are described in this overview from an interdisciplinary viewpoint. In addition, challenges to the creation of effective BAP systems are highlighted including future perspectives in terms of component integration from both a biological and an engineering viewpoint.

  7. Piezoelectric microelectromechanical resonant sensors for chemical and biological detection.

    PubMed

    Pang, Wei; Zhao, Hongyuan; Kim, Eun Sok; Zhang, Hao; Yu, Hongyu; Hu, Xiaotang

    2012-01-07

    Piezoelectric microelectromechanical systems (MEMS) resonant sensors, known for their excellent mass resolution, have been studied for many applications, including DNA hybridization, protein-ligand interactions, and immunosensor development. They have also been explored for detecting antigens, organic gas, toxic ions, and explosives. Most piezoelectric MEMS resonant sensors are acoustic sensors (with specific coating layers) that enable selective and label-free detection of biological events in real time. These label-free technologies have recently garnered significant attention for their sensitive and quantitative multi-parameter analysis of biological systems. Since piezoelectric MEMS resonant sensors do more than transform analyte mass or thickness into an electrical signal (e.g., frequency and impedance), special attention must be paid to their potential beyond microweighing, such as measuring elastic and viscous properties, and several types of sensors currently under development operate at different resonant modes (i.e., thickness extensional mode, thickness shear mode, lateral extensional mode, flexural mode, etc.). In this review, we provide an overview of recent developments in micromachined resonant sensors and activities relating to biochemical interfaces for acoustic sensors.

  8. A review on biological and chemical diversity in Berberis (Berberidaceae)

    PubMed Central

    Srivastava, Sharad; Srivastava, Manjoosha; Misra, Ankita; Pandey, Garima; Rawat, AKS

    2015-01-01

    Berberis is an important genus and well known in the Indian as well as European systems of traditional medicine. It is used since ancient times for curing eye disease, fever, jaundice, rheumatism, vomiting during pregnancy, kidney and gall balder stones and various other ailments due to the presence of biologically active alkaloid berberine. Action of the root extracts of few species are believed to be as powerful as quinine in the treatment of malarial fever. A plethora of literature pertaining to the taxonomy, biology, chemistry, traditional and ethnic uses of Berberis in different countries and indigenous cultures was collected by both offline (library, journals, textbooks etc.) and online mode (electronic search of available databases). In addition to this, books on traditional medicine and ethno pharmacological knowledge were also referred to extract ancient uses of Berberis in different traditional medicine systems. Most of the folklore, traditional and ethno botanical claims about Berberis species were validated by broad spectrum in vitro and vivo pharmacological studies. The present article summarizes its usage in eye and liver disorder, fever, kidney and gall stones along with anticancer activity. This comprehensive review will not only help researchers for further evaluation but also provide substantial information for future exploitation of species to develop novel herbal formulations. PMID:26535033

  9. Biological Kraft Chemical Recycle for Augmentation of Recovery Furnace Capacity

    SciTech Connect

    Stuart E. Strand

    2001-12-06

    The chemicals used in pulping of wood by the kraft process are recycled in the mill in the recovery furnace, which oxidizes organics while simultaneously reducing sulfate to sulfide. The recovery furnace is central to the economical operation of kraft pulp mills, but it also causes problems. The total pulp production of many mills is limited by the recovery furnace capacity, which cannot easily be increased. The furnace is one of the largest sources of air pollution (as reduced sulfur compounds) in the kraft pulp mill.

  10. Chemical biology of histone acetyltransferase natural compounds modulators.

    PubMed

    Piaz, Fabrizio Dal; Vassallo, Antonio; Rubio, Osmany Cuesta; Castellano, Sabrina; Sbardella, Gianluca; De Tommasi, Nunziatina

    2011-05-01

    Histone acetyltransferases (HATs) are a class of epigenetic enzymes crucial for chromatin restructuring and transcriptional regulation in eukaryotic cells, thus being a promising target for therapeutic development. Nonetheless, differently from histone deacetylases (HDACs) inhibitors, there is still paucity of small-molecule modulators of HAT activity. After a decline during past decade, natural products and their derivatives could be once again a valuable tool in the lead discovery process and meet such need of Novel Chemical Entities (NCEs). In this review, we will provide a comprehensive summary on the discovery of small-molecule HAT modulators from naturally occurring molecular scaffolds.

  11. Bacteriorhodopsin protein hybrids for chemical and biological sensing

    NASA Astrophysics Data System (ADS)

    Winder, Eric Michael

    Bacteriorhodopsin (bR), an optoelectric protein found in Halobacterium salinarum, has the potential for use in protein hybrid sensing systems. Bacteriorhodopsin has no intrinsic sensing properties, however molecular and chemical tools permit production of bR protein hybrids with transducing and sensing properties. As a proof of concept, a maltose binding protein-bacteriorhodopsin ([MBP]-bR) hybrid was developed. It was proposed that the energy associated with target molecule binding, maltose, to the hybrid sensor protein would provide a means to directly modulate the electrical output from the MBP-bR bio-nanosensor platform. The bR protein hybrid is produced by linkage between bR (principal component of purified purple membrane [PM]) and MBP, which was produced by use of a plasmid expression vector system in Escherichia coli and purified utilizing an amylose affinity column. These proteins were chemically linked using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), which facilitates formation of an amide bond between a primary carboxylic acid and a primary amine. The presence of novel protein hybrids after chemical linkage was analyzed by SDS-PAGE. Soluble proteins (MBP-only derivatives and unlinked MBP) were separated from insoluble proteins (PM derivatives and unlinked PM) using size exclusion chromatography. The putatively identified MBP-bR protein hybrid, in addition to unlinked bR, was collected. This sample was normalized for bR concentration to native PM and both were deposited onto indium tin oxide (ITO) coated glass slides by electrophoretic sedimentation. The photoresponse of both samples, activated using 100 Watt tungsten lamp at 10 cm distance, were equal at 175 mV. Testing of deposited PM with 1 mM sucrose or 1 mM maltose showed no change in the photoresponse of the material, however addition of 1 mM maltose to the deposited MBP-bR linked hybrid material elicited a 57% decrease in photoresponse

  12. De Novo Fragment Design for Drug Discovery and Chemical Biology.

    PubMed

    Rodrigues, Tiago; Reker, Daniel; Welin, Martin; Caldera, Michael; Brunner, Cyrill; Gabernet, Gisela; Schneider, Petra; Walse, Björn; Schneider, Gisbert

    2015-12-07

    Automated molecular de novo design led to the discovery of an innovative inhibitor of death-associated protein kinase 3 (DAPK3). An unprecedented crystal structure of the inactive DAPK3 homodimer shows the fragment-like hit bound to the ATP pocket. Target prediction software based on machine learning models correctly identified additional macromolecular targets of the computationally designed compound and the structurally related marketed drug azosemide. The study validates computational de novo design as a prime method for generating chemical probes and starting points for drug discovery.

  13. 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

  14. Capturing Biological Activity in Natural Product Fragments by Chemical Synthesis

    PubMed Central

    Crane, Erika A.

    2016-01-01

    Abstract Natural products have had an immense influence on science and have directly led to the introduction of many drugs. Organic chemistry, and its unique ability to tailor natural products through synthesis, provides an extraordinary approach to unlock the full potential of natural products. In this Review, an approach based on natural product derived fragments is presented that can successfully address some of the current challenges in drug discovery. These fragments often display significantly reduced molecular weights, reduced structural complexity, a reduced number of synthetic steps, while retaining or even improving key biological parameters such as potency or selectivity. Examples from various stages of the drug development process up to the clinic are presented. In addition, this process can be leveraged by recent developments such as genome mining, antibody–drug conjugates, and computational approaches. All these concepts have the potential to identify the next generation of drug candidates inspired by natural products. PMID:26833854

  15. Chemical biology approaches to designing defined carbohydrate vaccines.

    PubMed

    Anish, Chakkumkal; Schumann, Benjamin; Pereira, Claney Lebev; Seeberger, Peter H

    2014-01-16

    Carbohydrate antigens have shown promise as important targets for developing effective vaccines and pathogen detection strategies. Modifying purified microbial glycans through synthetic routes or completely synthesizing antigenic motifs are attractive options to advance carbohydrate vaccine development. However, limited knowledge on structure-property correlates hampers the discovery of immunoprotective carbohydrate epitopes. Recent advancements in tools for glycan modification, high-throughput screening of biological samples, and 3D structural analysis may facilitate antigen discovery process. This review focuses on advances that accelerate carbohydrate-based vaccine development and various technologies that are driving these efforts. Herein we provide a critical overview of approaches and resources available for rational design of better carbohydrate antigens. Structurally defined and fully synthetic oligosaccharides, designed based on molecular understanding of antigen-antibody interactions, offer a promising alternative for developing future carbohydrate vaccines.

  16. Fungal phytotoxins with potential herbicidal activity: chemical and biological characterization.

    PubMed

    Cimmino, Alessio; Masi, Marco; Evidente, Marco; Superchi, Stefano; Evidente, Antonio

    2015-12-19

    Covering: 2007 to 2015 Fungal phytotoxins are secondary metabolites playing an important role in the induction of disease symptoms interfering with host plant physiological processes. Although fungal pathogens represent a heavy constraint for agrarian production and for forest and environmental heritage, they can also represent an ecofriendly alternative to manage weeds. Indeed, the phytotoxins produced by weed pathogenic fungi are an efficient tool to design natural, safe bioherbicides. Their use could avoid that of synthetic pesticides causing resistance in the host plants and the long term impact of residues in agricultural products with a risk to human and animal health. The isolation and structural and biological characterization of phytotoxins produced by pathogenic fungi for weeds, including parasitic plants, are described. Structure activity relationships and mode of action studies for some phytotoxins are also reported to elucidate the herbicide potential of these promising fungal metabolites.

  17. Capturing Biological Activity in Natural Product Fragments by Chemical Synthesis.

    PubMed

    Crane, Erika A; Gademann, Karl

    2016-03-14

    Natural products have had an immense influence on science and have directly led to the introduction of many drugs. Organic chemistry, and its unique ability to tailor natural products through synthesis, provides an extraordinary approach to unlock the full potential of natural products. In this Review, an approach based on natural product derived fragments is presented that can successfully address some of the current challenges in drug discovery. These fragments often display significantly reduced molecular weights, reduced structural complexity, a reduced number of synthetic steps, while retaining or even improving key biological parameters such as potency or selectivity. Examples from various stages of the drug development process up to the clinic are presented. In addition, this process can be leveraged by recent developments such as genome mining, antibody-drug conjugates, and computational approaches. All these concepts have the potential to identify the next generation of drug candidates inspired by natural products.

  18. Non-Chemical Distant Cellular Interactions as a potential confounder of cell biology experiments

    PubMed Central

    Farhadi, Ashkan

    2014-01-01

    Distant cells can communicate with each other through a variety of methods. Two such methods involve electrical and/or chemical mechanisms. Non-chemical, distant cellular interactions may be another method of communication that cells can use to modify the behavior of other cells that are mechanically separated. Moreover, non-chemical, distant cellular interactions may explain some cases of confounding effects in Cell Biology experiments. In this article, we review non-chemical, distant cellular interactions studies to try to shed light on the mechanisms in this highly unconventional field of cell biology. Despite the existence of several theories that try to explain the mechanism of non-chemical, distant cellular interactions, this phenomenon is still speculative. Among candidate mechanisms, electromagnetic waves appear to have the most experimental support. In this brief article, we try to answer a few key questions that may further clarify this mechanism. PMID:25368582

  19. Laser-induced breakdown spectroscopy (LIBS) technique for the determination of the chemical composition of complex inorganic materials

    NASA Astrophysics Data System (ADS)

    Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Kozioł, Paweł E.; Stepak, Bogusz; Abramski, Krzysztof M.

    2014-08-01

    Laser-induced breakdown spectroscopy (LIBS) is a fast, fully optical method, that needs little or no sample preparation. In this technique qualitative and quantitative analysis is based on comparison. The determination of composition is generally based on the construction of a calibration curve namely the LIBS signal versus the concentration of the analyte. Typically, to calibrate the system, certified reference materials with known elemental composition are used. Nevertheless, such samples due to differences in the overall composition with respect to the used complex inorganic materials can influence significantly on the accuracy. There are also some intermediate factors which can cause imprecision in measurements, such as optical absorption, surface structure, thermal conductivity etc. This paper presents the calibration procedure performed with especially prepared pellets from the tested materials, which composition was previously defined. We also proposed methods of post-processing which allowed for mitigation of the matrix effects and for a reliable and accurate analysis. This technique was implemented for determination of trace elements in industrial copper concentrates standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for contents of three elements, that is silver, cobalt and vanadium. It has been shown that the described technique can be used to qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates.

  20. Chemical composition and biological activity of Salvia verbenaca essential oil.

    PubMed

    Canzoneri, Marisa; Bruno, Maurizio; Rosselli, Sergio; Russo, Alessandra; Cardile, Venera; Formisano, Carmen; Rigano, Daniela; Senatore, Felice

    2011-07-01

    Salvia verbenaca L. (syn. S. minore) is a perennial herb known in the traditional medicine of Sicily as "spaccapetri" and is used to resolve cases of kidney stones, chewing the fresh leaves or in decoction. The chemical composition of the essential oil obtained from aerial parts of S. verbenaca collected in Piano Battaglia (Sicily) on July 2009, was analyzed by GC and GC-MS. The oil was strongly characterized by fatty acids (39.5%) and carbonylic compounds (21.2%), with hexadecanoic acid (23.1%), (Z)-9-octadecenoic acid (11.1%) and benzaldehyde (7.3%) as the main constituents. The in vitro activity of the essential oil against some microorganisms in comparison with chloramphenicol by the broth dilution method was determined. The oil exhibited a good activity as inhibitor of growth of Gram + bacteria.

  1. Silicon chip integrated photonic sensors for biological and chemical sensing

    NASA Astrophysics Data System (ADS)

    Chakravarty, Swapnajit; Zou, Yi; Yan, Hai; Tang, Naimei; Chen, Ray T.

    2016-03-01

    We experimentally demonstrate applications of photonic crystal waveguide based devices for on-chip optical absorption spectroscopy for the detection of chemical warfare simulant, triethylphosphate as well as applications with photonic crystal microcavity devices in the detection of biomarkers for pancreatic cancer in patient serum and cadmium metal ions in heavy metal pollution sensing. At mid-infrared wavelengths, we experimentally demonstrate the higher sensitivity of photonic crystal based structures compared to other nanophotonic devices such as strip and slot waveguides with detection down to 10ppm triethylphosphate. We also detected 5ppb (parts per billion) of cadmium metal ions in water at near-infrared wavelengths using established techniques for the detection of specific probe-target biomarker conjugation chemistries.

  2. Integration between chemical oxidation and membrane thermophilic biological process.

    PubMed

    Bertanza, G; Collivignarelli, M C; Crotti, B M; Pedrazzani, R

    2010-01-01

    Full scale applications of activated sludge thermophilic aerobic process for treatment of liquid wastes are rare. This experimental work was carried out at a facility, where a thermophilic reactor (1,000 m(3) volume) is operated. In order to improve the global performance of the plant, it was decided to upgrade it, by means of two membrane filtration units (ultrafiltration -UF-, in place of the final sedimentation, and nanofiltration -NF-). Subsequently, the integration with chemical oxidation (O(3) and H(2)O(2)/UV processes) was taken into consideration. Studied solutions dealt with oxidation of both the NF effluents (permeate and concentrate). Based on experimental results and economic evaluation, an algorithm was proposed for defining limits of convenience of this process.

  3. Functional Nanostructured Platforms for Chemical and Biological Sensing

    SciTech Connect

    Letant, S E

    2006-03-20

    The central goal of our work is to combine semiconductor nanotechnology and surface functionalization in order to build platforms for the selective detection of bio-organisms ranging in size from bacteria (micron range) down to viruses, as well as for the detection of chemical agents (nanometer range). We will show on three porous silicon platforms how pore geometry and pore wall chemistry can be combined and optimized to capture and detect specific targets. We developed a synthetic route allowing to directly anchor proteins on silicon surfaces and illustrated the relevance of this technique by immobilizing live enzymes onto electrochemically etched luminescent nano-porous silicon. The powerful association of the specific enzymes with the transducing matrix led to a selective hybrid platform for chemical sensing. We also used light-assisted electrochemistry to produce periodic arrays of through pores on pre-patterned silicon membranes with controlled diameters ranging from many microns down to tens of nanometers. We demonstrated the first covalently functionalized silicon membranes and illustrated their selective capture abilities with antibody-coated micro-beads. These engineered membranes are extremely versatile and could be adapted to specifically recognize the external fingerprints (size and coat composition) of target bio-organisms. Finally, we fabricated locally functionalized single nanopores using a combination of focused ion beam drilling and ion beam assisted oxide deposition. We showed how a silicon oxide ring can be grown around a single nanopore and how it can be functionalized with DNA probes to detect single viral-sized beads. The next step for this platform is the detection of whole viruses and bacteria.

  4. TOPICAL REVIEW: Biological and chemical sensors for cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Simon, Elfriede

    2010-11-01

    The great challenge for sensor systems to be accepted as a relevant diagnostic and therapeutic tool for cancer detection is the ability to determine the presence of relevant biomarkers or biomarker patterns comparably to or even better than the traditional analytical systems. Biosensor and chemical sensor technologies are already used for several clinical applications such as blood glucose or blood gas measurements. However, up to now not many sensors have been developed for cancer-related tests because only a few of the biomarkers have shown clinical relevance and the performance of the sensor systems is not always satisfactory. New genomic and proteomic tools are used to detect new molecular signatures and identify which combinations of biomarkers may detect best the presence or risk of cancer or monitor cancer therapies. These molecular signatures include genetic and epigenetic signatures, changes in gene expressions, protein biomarker profiles and other metabolite profile changes. They provide new changes in using different sensor technologies for cancer detection especially when complex biomarker patterns have to be analyzed. To address requirements for this complex analysis, there have been recent efforts to develop sensor arrays and new solutions (e.g. lab on a chip) in which sampling, preparation, high-throughput analysis and reporting are integrated. The ability of parallelization, miniaturization and the degree of automation are the focus of new developments and will be supported by nanotechnology approaches. This review recaps some scientific considerations about cancer diagnosis and cancer-related biomarkers, relevant biosensor and chemical sensor technologies, their application as cancer sensors and consideration about future challenges.

  5. Functional nanostructured platforms for chemical and biological sensing

    NASA Astrophysics Data System (ADS)

    Létant, S. E.

    2006-05-01

    The central goal of our work is to combine semiconductor nanotechnology and surface functionalization in order to build platforms for the selective detection of bio-organisms ranging in size from bacteria (micron range) down to viruses, as well as for the detection of chemical agents (nanometer range). We will show on three porous silicon platforms how pore geometry and pore wall chemistry can be combined and optimized to capture and detect specific targets. We developed a synthetic route allowing to directly anchor proteins on silicon surfaces and illustrated the relevance of this technique by immobilizing live enzymes onto electrochemically etched luminescent nano-porous silicon. The powerful association of the specific enzymes with the transducing matrix led to a selective hybrid platform for chemical sensing. We also used light-assisted electrochemistry to produce periodic arrays of through pores on pre-patterned silicon membranes with controlled diameters ranging from many microns down to tens of nanometers. We demonstrated the first covalently functionalized silicon membranes and illustrated their selective capture abilities with antibody-coated micro-beads. These engineered membranes are extremely versatile and could be adapted to specifically recognize the external fingerprints (size and coat composition) of target bio-organisms. Finally, we fabricated locally functionalized single nanopores using a combination of focused ion beam drilling and ion beam assisted oxide deposition. We showed how a silicon oxide ring can be grown around a single nanopore and how it can be functionalized with DNA probes to detect single viral-sized beads. The next step for this platform is the detection of whole viruses and bacteria.

  6. Inorganic biomimetic nanostructures.

    PubMed

    Levine, Lauren A; Williams, Mary Elizabeth

    2009-12-01

    Supramolecular structures modeled after biological systems (DNA and enzymes) are being developed to simultaneously mimic natural biological functions including catalysis, information storage, and self-assembly and to engineer novel electronic and magnetic properties. Structural mimics of nucleic acids containing multiple metal-coordinating ligands, and comprising natural and artificial bases or completely synthetic systems, create stable double-stranded structures with new electronic, spectroscopic, and magnetic properties. Supramolecular inorganic mimics of enzymatic function, including metallonucleases and metalloproteases, have begun to be constructed. Alternatively, metal-organic-frameworks have potential as artificial catalysts with substrate-specificity and size-selectivity analogous to biological processes. This review describes some of the recent themes in inorganic supramolecular systems that aim to mimic and exploit nature's ability to self-assemble polyfunctional architectures for new materials and biological applications.

  7. Bioturbo similarity searching: combining chemical and biological similarity to discover structurally diverse bioactive molecules.

    PubMed

    Wassermann, Anne Mai; Lounkine, Eugen; Glick, Meir

    2013-03-25

    Virtual screening using bioactivity profiles has become an integral part of currently applied hit finding methods in pharmaceutical industry. However, a significant drawback of this approach is that it is only applicable to compounds that have been biologically tested in the past and have sufficient activity annotations for meaningful profile comparisons. Although bioactivity data generated in pharmaceutical institutions are growing on an unprecedented scale, the number of biologically annotated compounds still covers only a minuscule fraction of chemical space. For a newly synthesized compound or an isolated natural product to be biologically characterized across multiple assays, it may take a considerable amount of time. Consequently, this chemical matter will not be included in virtual screening campaigns based on bioactivity profiles. To overcome this problem, we herein introduce bioturbo similarity searching that uses chemical similarity to map molecules without biological annotations into bioactivity space and then searches for biologically similar compounds in this reference system. In benchmark calculations on primary screening data, we demonstrate that our approach generally achieves higher hit rates and identifies structurally more diverse compounds than approaches using chemical information only. Furthermore, our method is able to discover hits with novel modes of inhibition that traditional 2D and 3D similarity approaches are unlikely to discover. Test calculations on a set of natural products reveal the practical utility of the approach for identifying novel and synthetically more accessible chemical matter.

  8. A chemical-biological similarity-based grouping of complex substances as a prototype approach for evaluating chemical alternatives.

    PubMed

    Grimm, Fabian A; Iwata, Yasuhiro; Sirenko, Oksana; Chappell, Grace A; Wright, Fred A; Reif, David M; Braisted, John; Gerhold, David L; Yeakley, Joanne M; Shepard, Peter; Seligmann, Bruce; Roy, Tim; Boogaard, Peter J; Ketelslegers, Hans B; Rohde, Arlean M; Rusyn, Ivan

    2016-08-21

    Comparative assessment of potential human health impacts is a critical step in evaluating both chemical alternatives and existing products on the market. Most alternatives assessments are conducted on a chemical-by-chemical basis and it is seldom acknowledged that humans are exposed to complex products, not individual substances. Indeed, substances of Unknown or Variable composition, Complex reaction products, and Biological materials (UVCBs) are ubiquitous in commerce yet they present a major challenge for registration and health assessments. Here, we present a comprehensive experimental and computational approach to categorize UVCBs according to global similarities in their bioactivity using a suite of in vitro models. We used petroleum substances, an important group of UVCBs which are grouped for regulatory approval and read-across primarily on physico-chemical properties and the manufacturing process, and only partially based on toxicity data, as a case study. We exposed induced pluripotent stem cell-derived cardiomyocytes and hepatocytes to DMSO-soluble extracts of 21 petroleum substances from five product groups. Concentration-response data from high-content imaging in cardiomyocytes and hepatocytes, as well as targeted high-throughput transcriptomic analysis of the hepatocytes, revealed distinct groups of petroleum substances. Data integration showed that bioactivity profiling affords clustering of petroleum substances in a manner similar to the manufacturing process-based categories. Moreover, we observed a high degree of correlation between bioactivity profiles and physico-chemical properties, as well as improved groupings when chemical and biological data were combined. Altogether, we demonstrate how novel in vitro screening approaches can be effectively utilized in combination with physico-chemical characteristics to group complex substances and enable read-across. This approach allows for rapid and scientifically-informed evaluation of health impacts of

  9. Chemical constituents and biological activities of two Iranian Cystoseira species.

    PubMed

    Yegdaneh, Afsaneh; Ghannadi, Alireza; Dayani, Ladan

    2016-07-01

    The marine environment represents approximately half of the global biodiversity and could provide unlimited biological resources for the production of therapeutic drugs. Marine seaweeds comprise few thousands of species representing a considerable part of the littoral biomass. Extracts of the Cystoseira indica and Cystoseira merica were subjected to phytochemical and cytotoxicity evaluation. The amount of total phenol was determined with Folin-Ciocalteu reagent. Cytotoxicity was characterized by IC50 of human cancer cell lines including MCF-7 (human breast adenocarcinoma), HeLa (cervical carcinoma), and HT-29 (human colon adenocarcinoma) using Sulforhodamin assay. Antioxidant activities were evaluated using 2,2-diphenylpicrylhydrazyl (DPPH) method. The analysis revealed that tannins, saponins, sterols and triterpenes were the most abundant constituents in these Cystoseira species while cyanogenic and cardiac glycosides were the least ones. C. indica had the higher content of total phenolics and also showed higher antioxidant activity. Cytotoxic results showed that both species inhibited cell growth effectively, especially against MCF-7 cell line. The present findings suggest potential pharmacological applications of selected seaweeds but require further investigation and identification of their bioactive principles.

  10. Chemical constituents and biological activities of two Iranian Cystoseira species

    PubMed Central

    Yegdaneh, Afsaneh; Ghannadi, Alireza; Dayani, Ladan

    2016-01-01

    The marine environment represents approximately half of the global biodiversity and could provide unlimited biological resources for the production of therapeutic drugs. Marine seaweeds comprise few thousands of species representing a considerable part of the littoral biomass. Extracts of the Cystoseira indica and Cystoseira merica were subjected to phytochemical and cytotoxicity evaluation. The amount of total phenol was determined with Folin-Ciocalteu reagent. Cytotoxicity was characterized by IC50 of human cancer cell lines including MCF-7 (human breast adenocarcinoma), HeLa (cervical carcinoma), and HT-29 (human colon adenocarcinoma) using Sulforhodamin assay. Antioxidant activities were evaluated using 2,2-diphenylpicrylhydrazyl (DPPH) method. The analysis revealed that tannins, saponins, sterols and triterpenes were the most abundant constituents in these Cystoseira species while cyanogenic and cardiac glycosides were the least ones. C. indica had the higher content of total phenolics and also showed higher antioxidant activity. Cytotoxic results showed that both species inhibited cell growth effectively, especially against MCF-7 cell line. The present findings suggest potential pharmacological applications of selected seaweeds but require further investigation and identification of their bioactive principles. PMID:27651811

  11. Developing the Biomolecular Screening Facility at the EPFL into the Chemical Biology Screening Platform for Switzerland.

    PubMed

    Turcatti, Gerardo

    2014-05-01

    The Biomolecular Screening Facility (BSF) is a multidisciplinary laboratory created in 2006 at the Ecole Polytechnique Federale de Lausanne (EPFL) to perform medium and high throughput screening in life sciences-related projects. The BSF was conceived and developed to meet the needs of a wide range of researchers, without privileging a particular biological discipline or therapeutic area. The facility has the necessary infrastructure, multidisciplinary expertise and flexibility to perform large screening programs using small interfering RNAs (siRNAs) and chemical collections in the areas of chemical biology, systems biology and drug discovery. In the framework of the National Centres of Competence in Research (NCCR) Chemical Biology, the BSF is hosting 'ACCESS', the Academic Chemical Screening Platform of Switzerland that provides the scientific community with chemical diversity, screening facilities and know-how in chemical genetics. In addition, the BSF started its own applied research axes that are driven by innovation in thematic areas related to preclinical drug discovery and discovery of bioactive probes.

  12. Chemical speciation of heavy metals by surface-enhanced Raman scattering spectroscopy: identification and quantification of inorganic- and methyl-mercury in water.

    PubMed

    Guerrini, Luca; Rodriguez-Loureiro, Ignacio; Correa-Duarte, Miguel A; Lee, Yih Hong; Ling, Xing Yi; García de Abajo, F Javier; Alvarez-Puebla, Ramon A

    2014-07-21

    Chemical speciation of heavy metals has become extremely important in environmental and analytical research because of the strong dependence that toxicity, environmental mobility, persistence and bioavailability of these pollutants have on their specific chemical forms. Novel nano-optical-based detection strategies, capable of overcoming the intrinsic limitations of well-established analytic methods for the quantification of total metal ion content, have been reported, but the speciation of different chemical forms has not yet been achieved. Here, we report the first example of a SERS-based sensor for chemical speciation of toxic metal ions in water at trace levels. Specifically, the inorganic Hg(2+) and the more toxicologically relevant methylmercury (CH₃Hg(+)) are selected as analytical targets. The sensing platform consists of a self-assembled monolayer of 4-mercaptopyridine (MPY) on highly SERS-active and robust hybrid plasmonic materials formed by a dense layer of interacting gold nanoparticles anchored onto polystyrene microbeads. The co-ordination of Hg(2+) and CH₃Hg(+) to the nitrogen atom of the MPY ring yields characteristic changes in the vibrational SERS spectra of the organic chemoreceptor that can be qualitatively and quantitatively correlated to the presence of the two different mercury forms.

  13. Chemically directed assembly of nanoparticles for material and biological applications

    NASA Astrophysics Data System (ADS)

    Park, Myoung-Hwan

    The unique electronic, magnetic, and optical properties of nanoparticles (NPs) make them useful building blocks for nanodevices and biofabrication. Site-selective immobilization/deposition of NPs on surfaces at desired positions is an important fabrication step in realizing the potential of nanomaterials in these applications. In this thesis, my research has focused on developing new strategies for mono- and multilayered-NP deposition on surfaces, increasing the stability of NP-assembles upon various surfaces for practical use of NP-based devices. Chemically directed dithiocarbamate binding of amine groups to NPs in the presence of CS2 was used for enhancing the robustness of NP assembles. Such patterning methodologies have allowed me to use site-directed NP immobilization in applications as diverse as microcontact printing, nanomolding in capillaries, nanoimprint lithography, and photolithography. Also, I have developed a simple and reliable one-step technique to form robust dendrimer-NP nanocomposites using dithiocarbamate-based chemistry. These composites are able to encapsulate and release various therapeutics, providing controllable sustained release and to separate small molecules and biomacromolecules.

  14. Enhancement of immunotoxin activity using chemical and biological reagents.

    PubMed Central

    Wu, M.

    1997-01-01

    One of the major discoveries of effective therapeutics is the use of targeted treatment, such as antibody-directed toxins, i.e. immunotoxins; however, this medicine delivery strategy is still at a developmental stage. A number of problems need to be resolved; one is their inefficacy when applied in vivo. Research has stimulated interest in this area through the use of chemical reagents and other moieties to increase the activity of immunotoxins. In this article, reagents that can potentiate the cytotoxicity of immunotoxins are reviewed and the mechanisms that increase activity of immunotoxins are discussed. Lysosomotropic amines, especially ammonium chloride and chloroquine, may raise the pH value of the lysosome in which the conjugates enter. Carboxylic ionophores, e.g. monensin, can influence Golgi vacuolation, which may facilitate the routing of conjugates, augmenting activity. Calcium channel antagonists may increase immunotoxin killing through morphological or other mechanisms that are not yet well understood. Viral particles and surface structure can enhance the cytotoxicity of conjugates, probably through the mechanism of disrupting endosomes. In addition, cytokines, beta-adrenergic blockers, immunosuppressive agents (cyclosporin A) and some antibiotics (daunorubicin) can be used to increase the effect of immunotoxins. PMID:9155057

  15. Remote Detection of Biological Particles and Chemical Plumes Using UV Fluorescence Lidar

    NASA Technical Reports Server (NTRS)

    Tiee, J. J.; Hof, D. E.; Karl, R. R.; Martinez, R. J.; Quick, C. R.; Cooper, D. I.; Eichinger, W. E.; Holtkamp, D. B.

    1992-01-01

    A lidar system based on ultraviolet (UV) laser induced fluorescence (LIF) was developed for the remote detection of atmospherically dispersed biological particles and chemical vapors. This UV fluorescence lidar has many potential applications for monitoring environmental pollution, industrial waste emission, agricultural insect control, illicit chemical processing, and military defense operations. The general goal of this work is to investigate the research issues associated with the long range detection and identification of chemicals, e.g. aromatic solvents and chemical precursors, and biological materials, e.g. bacillus thuringiensis (BT) and bacillus globiggi (BG). In the detection of biological particulates, we are particularly interested in extending the detection range of an existing solar-blind 248-nm lidar system. We are investigating the use of longer excitation laser wavelengths (i.e. lambda greater than 280-nm to have more favorable atmospheric light transmission characteristics) for improving detection range to better than 10 km. In the detection of chemical plumes, our main research objectives are to determine how accurately and sensitively a chemical plume can be located at range, and how well spectrally the chemical species can be measured to allow their identification.

  16. Water quality index calculated from biological, physical and chemical attributes.

    PubMed

    Rocha, Francisco Cleiton; Andrade, Eunice Maia; Lopes, Fernando Bezerra

    2015-01-01

    To ensure a safe drinking water supply, it is necessary to protect water quality. To classify the suitability of the Orós Reservoir (Northeast of Brazil) water for human consumption, a Water Quality Index (WQI) was enhanced and refined through a Principal Component Analysis (PCA). Samples were collected bi-monthly at seven points (P1 - P7) from July 2009 to July 2011. Samples were analysed for 29 physico-chemical attributes and 4 macroinvertebrate metrics associated with the macrophytes Pistia stratiotes and Eichhornia crassipes. PCA allowed us to reduce the number of attributes from 33 to 12, and 85.32% of the variance was explained in five dimensions (C1 - C5). Components C1 and C3 were related to water-soluble salts and reflect the weathering process, while C2 was related to surface runoff. C4 was associated with macroinvertebrate diversity, represented by ten pollution-resistant families. C5 was related to the nutrient phosphorus, an indicator of the degree of eutrophication. The mean values for the WQIs ranged from 49 to 65 (rated as fair), indicating that water can be used for human consumption after treatment. The lowest values for the WQI were recorded at the entry points to the reservoir (P3, P1, P5, and P4), while the best WQIs were recorded at the exit points (P6 and P7), highlighting the reservoir's purification ability. The proposed WQI adequately expressed water quality, and can be used for monitoring surface water quality.

  17. Biological activities and chemical composition of lichens from Serbia

    PubMed Central

    Kosanic, Marijana; Rankovic, Branislav; Stanojkovic, Tatjana; Vasiljevic, Perica; Manojlovic, Nedeljko

    2014-01-01

    The aim of this study is to investigate chemical composition of acetone extracts of the lichens Parmelia arseneana and Acarospora fuscata and in vitro antioxidant, antimicrobial, and anticancer activities of these extracts and gyrophoric acid isolated from A. fuscata. The HPLC-UV method was used for the identification of secondary metabolites. Stictic acid, norstictic acid, gyrophoric acid, usnic acid, atranorin and chloroatranorin were identified in the A. fuscata. In P. arseneana, we detected stictic acid, norstictic acid, usnic acid and atranorin, while gyrophoric acid was not identified. Antioxidant activity was evaluated by measuring the scavenging capacity of tested samples on DPPH and superoxide anion radicals, reducing the power of samples and determination of total phenolic compounds in extracts. As a result of the study, gyrophoric acid was found to have the largest DPPH radical scavenging activity with an IC50 value of 105.75 µg/ml. Moreover, the tested samples had an effective superoxide anion radical scavenging and reducing power. The total content of phenol in extracts was determined as pyrocatechol equivalent. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was also gyrophoric acid, with minimum inhibitory concentration values ranging from 0.019 to 1.25 mg/ml. Anticancer activity was tested against LS174 (human colon carcinoma cell line), A549 (human lung carcinoma cell line), Fem-x (malignant melanoma cell line), and a chronic myelogeneous leukaemia K562 cell line using the MTT method. Extract of P. arseneana expressed the strongest anticancer activity against all cell lines with IC50 values ranging from 11.61 to 47.06 µg/ml. PMID:26417336

  18. A proposal for regional chemical and biological defense among the Balkan countries.

    PubMed

    Karayilanoğlu, Turan; Kenar, Levent

    2004-08-01

    In terms of preventing or reducing the mass disaster caused by chemical and biological warfare agents (CBWs), establishing an efficient chemical and biological defense (CBD) system is vital. Balkan countries including Turkey, Greece, Romania, and Bulgaria are located in the "hot region," where some of the neighboring countries have had a CBW production program or do not comply with the international treaties related to the prohibition of CBWs. On the other hand, setting up the CBD is difficult and requires excessive expenditure, which causes a large economical hardship. According to the point of view of Turkish nuclear, biological, and chemical scientists, who are well experienced with CBD, the formation of a CBD system in the Balkan countries would prevent the CBW threat in this region, and in addition, would be able to make a contribution to global security.

  19. Grasping the nature of the cell interior: from Physiological Chemistry to Chemical Biology.

    PubMed

    Kyne, Ciara; Crowley, Peter B

    2016-08-01

    Current models of the cell interior emphasise its crowded, chemically complex and dynamically organised structure. Although the chemical composition of cells is known, the cooperative intermolecular interactions that govern cell ultrastructure are poorly understood. A major goal of biochemistry is to capture these myriad interactions in vivo. We consider the landmark discoveries that have shaped this objective, starting from the vitalist framework established by early natural philosophers. Through this historical revisionism, we extract important lessons for the bioinspired chemists of today. Scientific specialisation tends to insulate seminal ideas and hamper the unification of paradigms across biology. Therefore, we call for interdisciplinary collaboration in grappling with the complex cell interior. Recent successes in integrative structural biology and chemical biology demonstrate the power of hybrid approaches. The future roles of the (bio)chemist and model systems are also discussed as starting points for in vivo explorations.

  20. 75 FR 62916 - Re-Delegation by the Under Secretary of State to the Director, Office of Chemical and Biological...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-13

    ...-Delegation by the Under Secretary of State to the Director, Office of Chemical and Biological Weapons Affairs... Chemical Weapons Convention Implementation Act of 1998, Division I of Pub. L. 105-277, codified at 22 U.S.C..., 2007, I hereby re-delegate to the Director, Office of Chemical and Biological Weapons Affairs,...

  1. Lead and compounds (inorganic)

    Integrated Risk Information System (IRIS)

    Lead and compounds ( inorganic ) ; CASRN 7439 - 92 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  2. Polyhedra in (inorganic) chemistry.

    PubMed

    Alvarez, Santiago

    2005-07-07

    A systematic description of polyhedra with varying degrees of regularity is illustrated with examples of chemical structures, mostly from different fields of Inorganic Chemistry. Also the geometrical relationships between different polyhedra are highlighted and their application to the analysis of complex structures is discussed.

  3. Recent Progress of Propolis for Its Biological and Chemical Compositions and Its Botanical Origin

    PubMed Central

    Toreti, Viviane Cristina; Sato, Helia Harumi; Pastore, Glaucia Maria; Park, Yong Kun

    2013-01-01

    Propolis is the generic name given to the product obtained from resinous substances, which is gummy and balsamic and which is collected by bees from flowers, buds, and exudates of plants. It is a popular folk medicine possessing a broad spectrum of biological activities. These biological properties are related to its chemical composition and more specifically to the phenolic compounds that vary in their structure and concentration depending on the region of production, availability of sources to collect plant resins, genetic variability of the queen bee, the technique used for production, and the season in which propolis is produced. Many scientific articles are published every year in different international journal, and several groups of researchers have focused their attention on the chemical compounds and biological activity of propolis. This paper presents a review on the publications on propolis and patents of applications and biological constituents of propolis. PMID:23737843

  4. Seeking the chemical roots of darwinism: bridging between chemistry and biology.

    PubMed

    Pross, Addy

    2009-08-24

    Chemistry and biology are intimately connected sciences yet the chemistry-biology interface remains problematic and central issues regarding the very essence of living systems remain unresolved. In this essay we build on a kinetic theory of replicating systems that encompasses the idea that there are two distinct kinds of stability in nature-thermodynamic stability, associated with "regular" chemical systems, and dynamic kinetic stability, associated with replicating systems. That fundamental distinction is utilized to bridge between chemistry and biology by demonstrating that within the parallel world of replicating systems there is a second law analogue to the second law of thermodynamics, and that Darwinian theory may, through scientific reductionism, be related to that second law analogue. Possible implications of these ideas to the origin of life problem and the relationship between chemical emergence and biological evolution are discussed.

  5. Requirement of a soluble intracellular factor for activation of transient receptor potential A1 by pungent chemicals: role of inorganic polyphosphates.

    PubMed

    Kim, Donghee; Cavanaugh, Eric J

    2007-06-13

    Pungent chemicals such as allyl isothiocyanate (AITC), cinnamaldehyde, and allicin, produce nociceptive sensation by directly activating transient receptor potential A1 (TRPA1) expressed in sensory afferent neurons. In this study, we found that pungent chemicals added to the pipette or bath solution easily activated TRPA1 in cell-attached patches but failed to do so in inside-out or outside-out patches. Thus, a soluble cytosolic factor was required to activate TRPA1. N-Ethylmaleimide, (2-aminoethyl)-methane thiosulfonate, 2-aminoethoxydiphneyl borate, and trinitrophenol, compounds that are known to activate TRPA1, also failed to activate it in inside-out patches. To identify a factor that supports activation of TRPA1 by pungent chemicals, we screened approximately 30 intracellular molecules known to modulate ion channels. Among them, pyrophosphate (PPi) and polytriphosphate (PPPi) were found to support activation of TRPA1 by pungent chemicals. Structure-function studies showed that inorganic polyphosphates (polyP(n), where n = number of phosphates) with at least four phosphate groups were highly effective (polyP4 approximately = polyP65 approximately = polyP45 approximately = polyP25 > PPPi > PPi), with K(1/2) values ranging from 0.2 to 2.8 mM. Inositol-trisphosphate and inositol-hexaphosphate also partially supported activation of TRPA1 by AITC. ATP, GTP, and phosphatidylinositol-4,5-bisphosphate that have three phosphate groups did not support TRPA1 activation. TRPA1 recorded from cell bodies of trigeminal ganglion neurons showed similar behavior with respect to sensitivity to pungent chemicals; no activation was observed in inside-out patches unless a polyphosphate was present. These results show that TRPA1 requires an intracellular factor to adopt a functional conformation that is sensitive to pungent chemicals and suggest that polyphosphates may partly act as such a factor.

  6. Counter Nuclear, Biological, and Chemical Operations, This document compliments JCS Pub 3-11

    DTIC Science & Technology

    2000-08-16

    of all education is the ability to make yourself do the thing you have to do, when it ought to be done, whether you like it or not. T. H . Huxley...to present.] Douglas, Joseph, and Livingstone, Neil , America the Vulnerable: The Threat of Chemical / Biological War- fare: The New Shape of...the Conflict in the Gulf (Little, Brown, and Company). 1995. Harris, Sheldon H ., Factories of Death: Japanese Biological Warfare, 1932-45, and the

  7. The efforts of WHO and Pugwash to eliminate chemical and biological weapons--a memoir.

    PubMed Central

    Kaplan, M. M.

    1999-01-01

    The World Health Organization and the Pugwash Conferences on Science and World Affairs (Nobel Peace Prize 1995) have been involved in questions concerning chemical and biological arms since the early 1950s. This memoir reviews a number of milestones in the efforts of these organizations to achieve the elimination of these weapons through international treaties effectively monitored and enforced for adherence to their provisions. It also highlights a number of outstanding personalities who were involved in the efforts to establish and implement the two major treaties now in effect, the Biological Weapons Convention of 1972 and the Chemical Weapons Convention of 1993. PMID:10083714

  8. Method and apparatus for the gas phase decontamination of chemical and biological agents

    DOEpatents

    O'Neill, Hugh J.; Brubaker, Kenneth L.

    2003-10-07

    An apparatus and method for decontaminating chemical and biological agents using the reactive properties of both the single atomic oxygen and the hydroxyl radical for the decontamination of chemical and biological agents. The apparatus is self contained and portable and allows for the application of gas reactants directly at the required decontamination point. The system provides for the use of ultraviolet light of a specific spectral range to photolytically break down ozone into molecular oxygen and hydroxyl radicals where some of the molecular oxygen is in the first excited state. The excited molecular oxygen will combine with water vapor to produce two hydroxyl radicals.

  9. Large-Area Chemical and Biological Decontamination Using a High Energy Arc Lamp (HEAL) System.

    SciTech Connect

    Duty, Chad E; Smith, Rob R; Vass, Arpad Alexander; Ilgner, Ralph H; Brown, Gilbert M

    2008-01-01

    Methods for quickly decontaminating large areas exposed to chemical and biological (CB) warfare agents can present significant logistical, manpower, and waste management challenges. Oak Ridge National Laboratory (ORNL) is pursuing an alternate method to decompose CB agents without the use of toxic chemicals or other potentially harmful substances. This process uses a high energy arc lamp (HEAL) system to photochemically decompose CB agents over large areas (12 m2). Preliminary tests indicate that more than 5 decades (99.999%) of an Anthrax spore simulant (Bacillus globigii) were killed in less than 7 seconds of exposure to the HEAL system. When combined with a catalyst material (TiO2) the HEAL system was also effective against a chemical agent simulant, diisopropyl methyl phosphonate (DIMP). These results demonstrate the feasibility of a rapid, large-area chemical and biological decontamination method that does not require toxic or corrosive reagents or generate hazardous wastes.

  10. Metabolic engineering for production of biorenewable fuels and chemicals: contributions of synthetic biology.

    PubMed

    Jarboe, Laura R; Zhang, Xueli; Wang, Xuan; Moore, Jonathan C; Shanmugam, K T; Ingram, Lonnie O

    2010-01-01

    Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes. It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol. We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors.

  11. Metabolic Engineering for Production of Biorenewable Fuels and Chemicals: Contributions of Synthetic Biology

    PubMed Central

    Jarboe, Laura R.; Zhang, Xueli; Wang, Xuan; Moore, Jonathan C.; Shanmugam, K. T.; Ingram, Lonnie O.

    2010-01-01

    Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes. It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol. We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors. PMID:20414363

  12. Reconnaissance survey of chemical contamination and biological effects in southern Puget Sound

    SciTech Connect

    Not Available

    1991-04-01

    The report describes the results of a field survey south of the Tacoma Narrows bridge in southern Puget Sound. Environmental conditions were evaluated in two urban embayments, eight nonurban embayments and three areas of the main channel in the southern Sound. Stations were located in depositional areas where chemical contaminants would be expected to accumulate in the sediments. All stations were located away from known contaminant sources in order to provide integrative assessments of contamination over relatively large areas. Chemical contamination of the south Sound was evaluated by measuring chemical concentrations in subtidal bottom sediments. Bioaccumulation of chemical contaminants was evaluated by measuring chemical concentrations in flatfish muscle tissues and littleneck clam meats. Chemical-related biological effects were evaluated by conducting amphipod sediment bioassays and histopathological analyses on livers of English sole.

  13. Biologically inspired large scale chemical sensor arrays and embedded data processing

    NASA Astrophysics Data System (ADS)

    Marco, S.; Gutiérrez-Gálvez, A.; Lansner, A.; Martinez, D.; Rospars, J. P.; Beccherelli, R.; Perera, A.; Pearce, T.; Vershure, P.; Persaud, K.

    2013-05-01

    Biological olfaction outperforms chemical instrumentation in specificity, response time, detection limit, coding capacity, time stability, robustness, size, power consumption, and portability. This biological function provides outstanding performance due, to a large extent, to the unique architecture of the olfactory pathway, which combines a high degree of redundancy, an efficient combinatorial coding along with unmatched chemical information processing mechanisms. The last decade has witnessed important advances in the understanding of the computational primitives underlying the functioning of the olfactory system. EU Funded Project NEUROCHEM (Bio-ICT-FET- 216916) has developed novel computing paradigms and biologically motivated artefacts for chemical sensing taking inspiration from the biological olfactory pathway. To demonstrate this approach, a biomimetic demonstrator has been built featuring a large scale sensor array (65K elements) in conducting polymer technology mimicking the olfactory receptor neuron layer, and abstracted biomimetic algorithms have been implemented in an embedded system that interfaces the chemical sensors. The embedded system integrates computational models of the main anatomic building blocks in the olfactory pathway: the olfactory bulb, and olfactory cortex in vertebrates (alternatively, antennal lobe and mushroom bodies in the insect). For implementation in the embedded processor an abstraction phase has been carried out in which their processing capabilities are captured by algorithmic solutions. Finally, the algorithmic models are tested with an odour robot with navigation capabilities in mixed chemical plumes

  14. Health Outcomes of Exposure to Biological and Chemical Components of Inhalable and Respirable Particulate Matter

    PubMed Central

    Morakinyo, Oyewale Mayowa; Mokgobu, Matlou Ingrid; Mukhola, Murembiwa Stanley; Hunter, Raymond Paul

    2016-01-01

    Particulate matter (PM) is a key indicator of air pollution and a significant risk factor for adverse health outcomes in humans. PM is not a self-contained pollutant but a mixture of different compounds including chemical and biological fractions. While several reviews have focused on the chemical components of PM and associated health effects, there is a dearth of review studies that holistically examine the role of biological and chemical components of inhalable and respirable PM in disease causation. A literature search using various search engines and (or) keywords was done. Articles selected for review were chosen following predefined criteria, to extract and analyze data. The results show that the biological and chemical components of inhalable and respirable PM play a significant role in the burden of health effects attributed to PM. These health outcomes include low birth weight, emergency room visit, hospital admission, respiratory and pulmonary diseases, cardiovascular disease, cancer, non-communicable diseases, and premature death, among others. This review justifies the importance of each or synergistic effects of the biological and chemical constituents of PM on health. It also provides information that informs policy on the establishment of exposure limits for PM composition metrics rather than the existing exposure limits of the total mass of PM. This will allow for more effective management strategies for improving outdoor air quality. PMID:27314370

  15. Incorporating biologically based models into assessments of risk from chemical contaminants

    NASA Technical Reports Server (NTRS)

    Bull, R. J.; Conolly, R. B.; De Marini, D. M.; MacPhail, R. C.; Ohanian, E. V.; Swenberg, J. A.

    1993-01-01

    The general approach to assessment of risk from chemical contaminants in drinking water involves three steps: hazard identification, exposure assessment, and dose-response assessment. Traditionally, the risks to humans associated with different levels of a chemical have been derived from the toxic responses observed in animals. It is becoming increasingly clear, however, that further information is needed if risks to humans are to be assessed accurately. Biologically based models help clarify the dose-response relationship and reduce uncertainty.

  16. [Biological, chemical, and radiation factors in the classification of medical waste].

    PubMed

    Rusakov, N V; Korotkova, G I; Orlov, A Iu; Kadyrov, D E

    2011-01-01

    The current classification of medical waste does not consider the sanitary-and-chemical hazard of epidemiologically dangerous and extremely dangerous medical waste (classes B and C). According to the results of the studies performed, the authors propose the improved classification of medical waste, which makes it possible to take into account not only infectious, radiation, and toxicological, but also sanitary-and-chemical hazards (toxicity, carcinogenicity, mutagenicity, and biological activity) of medical waste.

  17. Distributions of inorganic nitrogen and biological production in the equatorial Pacific: a basin-scale model sensitivity study of nitrification

    NASA Astrophysics Data System (ADS)

    Wang, Xiujun; Murtugudde, Raghu

    2015-12-01

    Recent evidence indicates that there is stronger nitrification in the euphotic zone than previously thought. We employ a physical-biogeochemical model to study the implications of nitrification for basin-scale distributions of nitrate, ammonium, and biological production in the equatorial Pacific. The model can faithfully reproduce observed features in nitrate distribution, with or without photoinhibition of nitrification in the euphotic zone. In addition, new production, net community production and export production are not very sensitive to the parameterization of nitrification in this model. However, simulated ammonium distribution, nitrate uptake and ammonium uptake are sensitive to this parameterization. High nitrification results in low ammonium concentration, low ammonium uptake rate, and high nitrate uptake rate in the euphotic zone. This study suggests that nitrification may be responsible for up to 40% of nitrate uptake in the equatorial Pacific. This modeling study also demonstrates large differences (in terms of the magnitude and spatial distribution) between nitrate uptake, new production and export production, reflecting decoupling of upward nutrient supply, biological uptake and downward export.

  18. Chemical and Biological Profiling Approaches for Exploring Mutagenicity and Carcinogenicity of EPA ToxCast Chemicals

    EPA Science Inventory

    Phase I of U.S. Environmental Protection Agency’s ToxCastTM research project is building on three rich data tiers: 309 unique, structurally diverse chemicals (predominantly pesticides), activity and concentration response data from approximately 500 in vitro (cell-based and cell-...

  19. Exploring biological, chemical and geomorphological patterns in fluvial ecosystems with Structural Equation Modelling

    NASA Astrophysics Data System (ADS)

    Bizzi, S.; Surridge, B.; Lerner, D. N.:

    2009-04-01

    River ecosystems represent complex networks of interacting biological, chemical and geomorphological processes. These processes generate spatial and temporal patterns in biological, chemical and geomorphological variables, and a growing number of these variables are now being used to characterise the status of rivers. However, integrated analyses of these biological-chemical-geomorphological networks have rarely been undertaken, and as a result our knowledge of the underlying processes and how they generate the resulting patterns remains weak. The apparent complexity of the networks involved, and the lack of coherent datasets, represent two key challenges to such analyses. In this paper we describe the application of a novel technique, Structural Equation Modelling (SEM), to the investigation of biological, chemical and geomorphological data collected from rivers across England and Wales. The SEM approach is a multivariate statistical technique enabling simultaneous examination of direct and indirect relationships across a network of variables. Further, SEM allows a-priori conceptual or theoretical models to be tested against available data. This is a significant departure from the solely exploratory analyses which characterise other multivariate techniques. We took biological, chemical and river habitat survey data collected by the Environment Agency for 400 sites in rivers spread across England and Wales, and created a single, coherent dataset suitable for SEM analyses. Biological data cover benthic macroinvertebrates, chemical data relate to a range of standard parameters (e.g. BOD, dissolved oxygen and phosphate concentration), and geomorphological data cover factors such as river typology, substrate material and degree of physical modification. We developed a number of a-priori conceptual models, reflecting current research questions or existing knowledge, and tested the ability of these conceptual models to explain the variance and covariance within the

  20. Molecular building blocks and their architecture in biologically/environmentally compatible soft matter chemical machinery.

    PubMed

    Toyota, Taro; Banno, Taisuke; Nitta, Sachiko; Takinoue, Masahiro; Nomoto, Tomonori; Natsume, Yuno; Matsumura, Shuichi; Fujinami, Masanori

    2014-01-01

    This review briefly summarizes recent developments in the construction of biologically/environmentally compatible chemical machinery composed of soft matter. Since environmental and living systems are open systems, chemical machinery must continuously fulfill its functions not only through the influx and generation of molecules but also via the degradation and dissipation of molecules. If the degradation or dissipation of soft matter molecular building blocks and biomaterial molecules/polymers can be achieved, soft matter particles composed of them can be used to realize chemical machinery such as selfpropelled droplets, drug delivery carriers, tissue regeneration scaffolds, protocell models, cell-/tissuemarkers, and molecular computing systems.

  1. Field Characterization of Potential Reference Sediments in the Gulf of Mexico: Chemical and Biological Quality

    EPA Science Inventory

    Lewis, Michael A., Jed G. Campbell, Peggy S. Harris, Darrin D. Dantin, Steve S. Foss, Robert L. Quarles, James C. Moore and Cynthia A. Chancy. Submitted. Characterization of Potential Reference Areas in the Gulf of Mexico: Near-Coastal Sediment Chemical and Biological Quality. En...

  2. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FILL MATERIAL Evaluation and Testing § 230.61 Chemical, biological, and physical evaluation and testing... materials. This section provides some guidance in determining which test and/or evaluation procedures are... effects. The principal concerns of discharge of dredged or fill material that contain contaminants are...

  3. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FILL MATERIAL Evaluation and Testing § 230.61 Chemical, biological, and physical evaluation and testing... materials. This section provides some guidance in determining which test and/or evaluation procedures are... effects. The principal concerns of discharge of dredged or fill material that contain contaminants are...

  4. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FILL MATERIAL Evaluation and Testing § 230.61 Chemical, biological, and physical evaluation and testing... materials. This section provides some guidance in determining which test and/or evaluation procedures are... effects. The principal concerns of discharge of dredged or fill material that contain contaminants are...

  5. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FILL MATERIAL Evaluation and Testing § 230.61 Chemical, biological, and physical evaluation and testing... materials. This section provides some guidance in determining which test and/or evaluation procedures are... effects. The principal concerns of discharge of dredged or fill material that contain contaminants are...

  6. 40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FILL MATERIAL Evaluation and Testing § 230.61 Chemical, biological, and physical evaluation and testing... materials. This section provides some guidance in determining which test and/or evaluation procedures are... effects. The principal concerns of discharge of dredged or fill material that contain contaminants are...

  7. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: II. CHEMICAL AND BIOLOGICAL CHARACTERISTICS

    EPA Science Inventory

    The objective of this research was to examine the performance of five North American bioreactor landfills. This paper represents the second of a two part series and addresses biological and chemical aspects of bioreactor performance including gas production and management, and l...

  8. Mass spectrometry in identification of ecotoxicants including chemical and biological warfare agents.

    PubMed

    Lebedev, Albert T

    2005-09-01

    Mass spectrometry is a unique tool to detect and identify trace levels of organic and bioorganic compounds as well as microorganisms in the environment. The range of potential chemical warfare (CW) and biological warfare (BW) agents is very broad. An important advantage of mass spectrometry over other techniques involves potential for full spectrum detection of chemical and biological agents including mid-spectrum materials (i.e. bioactive peptides, toxins, etc.) for which biological approaches are inadequate. Being very fast (seconds and minutes), extremely sensitive (zeptomoles 10(-21)), and informative (detailed qualitative and quantitative composition of mixtures containing hundreds of chemicals), mass spectrometry is a principal analytical tool at the sites of destruction of CW. Due to its unique features, mass spectrometry is applied not only for the detection of CW agents, but for the analysis of products of metabolism and degradation of these agents in organisms or environment as well. The present paper deals with some examples of successful application of mass spectrometry for the analyses of ecotoxicants, chemical warfare agents, explosives, and microorganisms including biology warfare agents.

  9. Mass spectrometry in identification of ecotoxicants including chemical and biological warfare agents

    SciTech Connect

    Lebedev, Albert T. . E-mail: lebedev@org.chem.msu.ru

    2005-09-01

    Mass spectrometry is a unique tool to detect and identify trace levels of organic and bioorganic compounds as well as microorganisms in the environment. The range of potential chemical warfare (CW) and biological warfare (BW) agents is very broad. An important advantage of mass spectrometry over other techniques involves potential for full spectrum detection of chemical and biological agents including mid-spectrum materials (i.e. bioactive peptides, toxins, etc.) for which biological approaches are inadequate. Being very fast (seconds and minutes), extremely sensitive (zeptomoles 10{sup -21}), and informative (detailed qualitative and quantitative composition of mixtures containing hundreds of chemicals), mass spectrometry is a principal analytical tool at the sites of destruction of CW. Due to its unique features, mass spectrometry is applied not only for the detection of CW agents, but for the analysis of products of metabolism and degradation of these agents in organisms or environment as well. The present paper deals with some examples of successful application of mass spectrometry for the analyses of ecotoxicants, chemical warfare agents, explosives, and microorganisms including biology warfare agents.

  10. Chemical composition and biological activity of the essential oil of rhizome of Zingiber zerumbet (L.) smith

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract: The aim was designed to study the biological activity and chemical composition of essential oil of Zingiber zerumbet (L.) Smith. The essential oil extracted from the rhizome of the plant was analysed by gas chromatography-mass spectroscopy and its major components amounting t...

  11. CBW - are we prepared to combat the chemical/biological threat. Final report

    SciTech Connect

    Kirkman, A.

    1994-02-08

    This research paper analyzes the current chemical and biological threat faced by the United States from Third World Countries. It explores the impact this threat brings on military planning and execution and recommends avenues that the United States should take to hedge against it. A historical background of chemical and biological weapons use is presented with emphasis on the magnitude and extent of this problem. The legal and moral frameworks are examined with focus on the capabilities, limitations, intentions, and preparedness of the United States and Third World Countries. The thesis presented is that the United States' posture in combating chemical and biological weapons is severely compromised. A lack of governmental commitment, inadequate technologies, lack of success in arms control negotiations, and an inability to control proliferation, compounds the problem. Although no U.S. forces were exposed to chemical or biological weapons in our latest conflict with Iraq, the future does not hold the promise that we will be as lucky the next time. And there will be a next time.

  12. Joint Service Chemical and Biological Defense Program. FY00-02 Overview

    DTIC Science & Technology

    2001-09-01

    operations at high levels of effectiveness . Combat power is restored as soon as possible by decontamination and medical treatment. The synergistic ...targets. The pivotal characteristic of precision engagement is the link- ing of sensors, delivery systems, and effects . Challenge: Chemical and biological...optimal midazolam – anticholinergic drug combination and order of administration to obtain maximal anticonvulsant effect against seizures in a non

  13. Department of Defense Chemical, Biological, Radiological and Nuclear Defense Program Overview

    DTIC Science & Technology

    2004-04-06

    effectively execute the National Strategy for Combating Weapons of Mass Destruction. Ensure all capabilities are integrated and coordinated within the... BACTERIA VIRUSES RICKETTSIAE GENETIC ENGINEERED MICRO-ORGANISMS BWCW CLEARLY CHEMICAL CLEARLY BIOLOGICAL Traditional Nuclear Nuclear Bombs Nuclear Missiles...systems integration, and information flow in a timely and cost effective manner Goal 5 Leverage DOD CBRN defense expertise to support vital national

  14. The search for life's origins: Progress and future directions in planetary biology and chemical evolution

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The current state is reviewed of the study of chemical evolution and planetary biology and the probable future is discussed of the field, at least for the near term. To this end, the report lists the goals and objectives of future research and makes detailed, comprehensive recommendations for accomplishing them, emphasizing those issues that were inadequately discussed in earlier Space Studies Board reports.

  15. CONCEPTUAL FRAMEWORK FOR THE CHEMICAL EFFECTS IN BIOLOGICAL SYSTEMS (CEBS) TOXICOGENOMICS KNOWLEDGE BASE

    EPA Science Inventory

    Conceptual Framework for the Chemical Effects in Biological Systems (CEBS) T oxicogenomics Knowledge Base

    Abstract
    Toxicogenomics studies how the genome is involved in responses to environmental stressors or toxicants. It combines genetics, genome-scale mRNA expressio...

  16. Joint Service Chemical and Biological Defense Program FY 08-09 Overview

    DTIC Science & Technology

    2007-10-01

    understanding of biophysical fluid dynamics at nanosensor surfaces in microfluidic systems and how biomolecules and labels interact with functionalized...to protect personnel and vital ship spaces from toxic chemicals, biological agents, and radioactive fallout. The collective protection system (CPS) is

  17. EVALUATION OF REAL-TIME INNOVATIVE BIOLOGICAL AND CHEMICAL MONITORING SYSTEMS TO PROTECT SOURCE WATERS

    EPA Science Inventory

    Evaluation of Real-Time Innovative Biological and Chemical Monitoring Systems
    To Protect Source Waters

    Drinking water supplies have in recent years come under increasing pressure from regulatory concerns regarding TMDL designations and restoration strategies as well ...

  18. Weapons of mass destruction: Overview of the CBRNEs (Chemical, Biological, Radiological, Nuclear, and Explosives).

    PubMed

    Prockop, Leon D

    2006-11-01

    The events of September 11, 2001, made citizens of the world acutely aware of disasters consequent to present-day terrorism. This is a war being waged for reasons obscure to many of its potential victims. The term "NBCs" was coined in reference to terrorist weapons of mass destruction, i.e., nuclear, biological and chemical. The currently accepted acronym is "CBRNE" which includes Chemical, Biological, Radiological, Nuclear, and Explosive weapons. Non-nuclear explosives are the most common terrorist weapon now in use. Nuclear and radiological weapons are beyond the scope of this publication, which focuses on the "CBEs", i.e. chemical, biological and explosive weapons. Although neurologists will not be the first responders to CBEs, they must know about the neurological effects in order to provide diagnosis and treatment to survivors. Neurological complications of chemical, biological and explosive weapons which have or may be used by terrorists are reviewed by international experts in this publication. Management and treatment profiles are outlined.

  19. 40. Perimeter acquisition radar building room #510B, chemical, biological, and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Perimeter acquisition radar building room #510B, chemical, biological, and radiological (CBR) air filter room no. 1 - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  20. Chemical and biological extraction of metals present in E waste: A hybrid technology

    SciTech Connect

    Pant, Deepak; Joshi, Deepika; Upreti, Manoj K.; Kotnala, Ravindra K.

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Hybrid methodology for E waste management. Black-Right-Pointing-Pointer Efficient extraction of metals. Black-Right-Pointing-Pointer Trace metal extraction is possible. - Abstract: Management of metal pollution associated with E-waste is widespread across the globe. Currently used techniques for the extraction of metals from E-waste by using either chemical or biological leaching have their own limitations. Chemical leaching is much rapid and efficient but has its own environmental consequences, even the future prospects of associated nanoremediation are also uncertain. Biological leaching on the other hand is comparatively a cost effective technique but at the same moment it is time consuming and the complete recovery of the metal, alone by biological leaching is not possible in most of the cases. The current review addresses the individual issues related to chemical and biological extraction techniques and proposes a hybrid-methodology which incorporates both, along with safer chemicals and compatible microbes for better and efficient extraction of metals from the E-waste.

  1. Comparison of biological and chemical phosphorus removals in continuous and sequencing batch reactors

    SciTech Connect

    Ketchum, L.H.; Irvine, R.L. Jr.; Breyfogle, R.E.; Manning, J.F. Jr.

    1987-01-01

    A full-scale study of phosphorus removal has been conducted at Culver using continuous-flow operation, SBR operation, and several different chemical treatment schemes. A full-scale demonstration of SBR biological phosphorus removal also has been shown to be effective. Four contributing groups of organisms and their roles in biological SBR phosphorus removal have been described: denitrifying organisms, fermentation product-manufacturing organisms, phosphorus- accumulating organisms, and aerobic autotrophs and heterotrophs. The SBR can provide the proper balance of anoxic, anaerobic, and aerobic conditions to allow these group of organisms to successfully remove phosphorus biologically, without chemical addition. Treatment results using various chemicals for phosphorus removal, both during conventional, continuous-flow operation and after the plant was converted for SBR operation, have also been provided for comparison. Effluent phosphorus concentrations were almost identical for each period, except for the period when phosphorus was removed biologically and without any chemical addition when effluent phosphorus concentrations were the lowest. These removals were made as a result of settling alone; no tertiary rapid stand filter was used or required.

  2. Chemical and biological diversity of the volatiles of five Artemisia species from far east of Russia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aim of the present study was to investigate the chemical composition and biological activity of essential oils from aerial parts of Artemisia argyi, A. feddei, A. gmelinii, A. manshurica, A. olgensis (Asteraceae). Plants were collected in the Far East region (Primorski Krai) of the Russian Federatio...

  3. 77 FR 47117 - Chemical, Biological, Radiological, Nuclear (CBRN) Protective Ensemble Standard, Certification...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ...In an effort to obtain comments from interested parties, the U.S. Department of Justice, Office of Justice Programs, National Institute of Justice (NIJ) will make available to the general public (at www.justnet.org) three draft documents related to Chemical, Biological, Radiological, Nuclear (CBRN) protective ensembles used by law enforcement...

  4. 78 FR 38782 - Lifting of Chemical and Biological Weapons (CBW) Proliferation Sanctions Against Chinese Entities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Lifting of Chemical and Biological Weapons (CBW) Proliferation Sanctions Against Chinese Entities AGENCY: Department of State. ACTION: Notice. SUMMARY: A determination has been made, pursuant to Section 81(e) of...

  5. Estimating Toxicity-Related Biological Pathway Altering Doses for High-Throughput Chemical Risk Assessment

    EPA Science Inventory

    We describe a framework for estimating the human dose at which a chemical significantly alters a biological pathway in vivo, making use of in vitro assay data and an in vitro derived pharmacokinetic model, coupled with estimates of population variability and uncertainty. The q...

  6. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae.

    PubMed

    Li, Mingji; Borodina, Irina

    2015-02-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae We describe computational tools for the prediction of biochemical pathways, molecular biology methods for assembly of DNA parts into pathways, and for introducing the pathways into the host, and finally approaches for optimizing performance of the introduced pathways.

  7. "No practical capabilities": American biological and chemical warfare programs during the Korean war.

    PubMed

    Crane, Conrad C

    2002-01-01

    Much controversy still surrounds accusations that American forces in the Far East during the Korean War used biological warfare against North Korea and China. An analysis of recently declassified documents reveals that, although the United States attempted to accelerate its development and acquisition of such weapons during that period, its efforts to create a viable biological warfare capability were unsuccessful. Plans to similarly expand chemical warfare stocks and capabilities were also frustrated. Technological difficulties, personnel shortages, bureaucratic battles between the armed services, and policy limitations combined to hold back advances in American chemical and biological warfare. In light of the recent fears of terrorist attacks with such weapons, this analysis highlights the great difficulties involved in developing, acquiring, and delivering such capabilities.

  8. Total, chemical, and biological oxygen consumption of the sediments in the Ziya River watershed, China.

    PubMed

    Rong, Nan; Shan, Baoqing

    2016-07-01

    Sediment oxygen demand (SOD) is a critical dissolved oxygen (DO) sink in many rivers. Understanding the relative contributions of the biological and chemical components of SOD would improve our knowledge of the potential environmental harm SOD could cause and allow appropriate management systems to be developed. A various inhibitors addition technique was conducted to measure the total, chemical, and biological SOD of sediment samples from 13 sites in the Ziya River watershed, a severely polluted and anoxic river system in the north of China. The results showed that the major component of SOD was chemical SOD due to iron predominate. The ferrous SOD accounted for 21.6-78.9 % of the total SOD and 33.26-96.79 % of the chemical SOD. Biological SOD represented 41.13 % of the overall SOD averagely. Sulfide SOD accounted for 1.78-45.71 % of the total SOD and it was the secondary predominate of the chemical SOD. Manganous SOD accounted for 1.2-16.6 % of the total SOD and it was insignificant at many sites. Only four kinds of benthos were collected in the Ziya River watershed, resulting from the low DO concentration in the sediment surface due to SOD. This study would be helpful for understanding and preventing the potential sediment oxygen depletion during river restoration.

  9. Microfluidics in inorganic chemistry.

    PubMed

    Abou-Hassan, Ali; Sandre, Olivier; Cabuil, Valérie

    2010-08-23

    The application of microfluidics in chemistry has gained significant importance in the recent years. Miniaturized chemistry platforms provide controlled fluid transport, rapid chemical reactions, and cost-saving advantages over conventional reactors. The advantages of microfluidics have been clearly established in the field of analytical and bioanalytical sciences and in the field of organic synthesis. It is less true in the field of inorganic chemistry and materials science; however in inorganic chemistry it has mostly been used for the separation and selective extraction of metal ions. Microfluidics has been used in materials science mainly for the improvement of nanoparticle synthesis, namely metal, metal oxide, and semiconductor nanoparticles. Microfluidic devices can also be used for the formulation of more advanced and sophisticated inorganic materials or hybrids.

  10. Chemical speciation of heavy metals by surface-enhanced Raman scattering spectroscopy: identification and quantification of inorganic- and methyl-mercury in water

    NASA Astrophysics Data System (ADS)

    Guerrini, Luca; Rodriguez-Loureiro, Ignacio; Correa-Duarte, Miguel A.; Lee, Yih Hong; Ling, Xing Yi; García de Abajo, F. Javier; Alvarez-Puebla, Ramon A.

    2014-06-01

    Chemical speciation of heavy metals has become extremely important in environmental and analytical research because of the strong dependence that toxicity, environmental mobility, persistence and bioavailability of these pollutants have on their specific chemical forms. Novel nano-optical-based detection strategies, capable of overcoming the intrinsic limitations of well-established analytic methods for the quantification of total metal ion content, have been reported, but the speciation of different chemical forms has not yet been achieved. Here, we report the first example of a SERS-based sensor for chemical speciation of toxic metal ions in water at trace levels. Specifically, the inorganic Hg2+ and the more toxicologically relevant methylmercury (CH3Hg+) are selected as analytical targets. The sensing platform consists of a self-assembled monolayer of 4-mercaptopyridine (MPY) on highly SERS-active and robust hybrid plasmonic materials formed by a dense layer of interacting gold nanoparticles anchored onto polystyrene microbeads. The co-ordination of Hg2+ and CH3Hg+ to the nitrogen atom of the MPY ring yields characteristic changes in the vibrational SERS spectra of the organic chemoreceptor that can be qualitatively and quantitatively correlated to the presence of the two different mercury forms.Chemical speciation of heavy metals has become extremely important in environmental and analytical research because of the strong dependence that toxicity, environmental mobility, persistence and bioavailability of these pollutants have on their specific chemical forms. Novel nano-optical-based detection strategies, capable of overcoming the intrinsic limitations of well-established analytic methods for the quantification of total metal ion content, have been reported, but the speciation of different chemical forms has not yet been achieved. Here, we report the first example of a SERS-based sensor for chemical speciation of toxic metal ions in water at trace levels

  11. Functional Components of Carob Fruit: Linking the Chemical and Biological Space.

    PubMed

    Goulas, Vlasios; Stylos, Evgenios; Chatziathanasiadou, Maria V; Mavromoustakos, Thomas; Tzakos, Andreas G

    2016-11-10

    The contribution of natural products to the drug-discovery pipeline has been remarkable since they have served as a rich source for drug development and discovery. Natural products have adapted, during the course of evolution, optimum chemical scaffolds against a wide variety of diseases, including cancer and diabetes. Advances in high-throughput screening assays, assisted by the continuous development on the instrumentation's capabilities and omics, have resulted in charting a large chemical and biological space of drug-like compounds, originating from natural sources. Herein, we attempt to integrate the information on the chemical composition and the associated biological impact of carob fruit in regards to human health. The beneficial and health-promoting effects of carob along with the clinical trials and the drug formulations derived from carob's natural components are presented in this review.

  12. Surface-enhanced Raman scattering (SERS) detection for chemical and biological agents

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Stokes, David L.; Wabuyele, Musundi B.; Griffin, Guy D.; Vass, Arpad A.; Vo-Dinh, Tuan

    2004-07-01

    Surface-enhanced Raman scattering (SERS) spectra of chemical agent simulants such as dimethyl methylphonate (DMMP), pinacolyl methylphosphonate (PMP), diethyl phosphoramidate (DEPA), and 2-chloroethyl ethylsulfide (CEES), and biological agent simulants such as bacillus globigii (BG), erwinia herbicola (EH), and bacillus thuringiensis (BT) were obtained from silver oxide film-deposited substrates. Thin AgO films ranging in thickness from 50 nm to 250 nm were produced by chemical bath deposition onto glass slides. Further Raman intensity enhancements were noticed in UV irradiated surfaces due to photo-induced Ag nanocluster formation, which may provide a possible route to producing highly useful plasmonic sensors for the detection of chemical and biological agents upon visible light illumination.

  13. Functional Components of Carob Fruit: Linking the Chemical and Biological Space

    PubMed Central

    Goulas, Vlasios; Stylos, Evgenios; Chatziathanasiadou, Maria V.; Mavromoustakos, Thomas; Tzakos, Andreas G.

    2016-01-01

    The contribution of natural products to the drug-discovery pipeline has been remarkable since they have served as a rich source for drug development and discovery. Natural products have adapted, during the course of evolution, optimum chemical scaffolds against a wide variety of diseases, including cancer and diabetes. Advances in high-throughput screening assays, assisted by the continuous development on the instrumentation’s capabilities and omics, have resulted in charting a large chemical and biological space of drug-like compounds, originating from natural sources. Herein, we attempt to integrate the information on the chemical composition and the associated biological impact of carob fruit in regards to human health. The beneficial and health-promoting effects of carob along with the clinical trials and the drug formulations derived from carob’s natural components are presented in this review. PMID:27834921

  14. Physical, chemical, and biological data for selected streams in Chester County, Pennsylvania, 1981-94

    USGS Publications Warehouse

    Reif, Andrew G.

    1999-01-01

    Physical, chemical, and biological data were collected at 51 sampling sites in Chester County, Pa., from 1970 through 1994 as part of the Stream Conditions of Chester County Program. This report presents data collected from 1981 through 1994. Physical data include water temperature, instantaneous stream discharge, pH, alkalinity, specific conductance, and dissolved oxygen. Chemical data include laboratory determinations of nutrients, major ions, and selected metals in whole water samples and selected metals, pesticides, gross polychlorinated biphenyls (PCB?s), gross polychlorinated napthalenes (PCN?s), and total carbon in stream-bottom sediment samples. The biological data consists of benthic macroinvertebrate population analyses and diversity indices. Chester County is undergoing rapid urbanization as agricultural lands are converted to residential, commercial, and industrial areas. The purpose of the Stream Conditions of Chester County Program is to further the understanding of stream habitat and chemical changes in response to this urbanization.

  15. Stable colloids in molten inorganic salts

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Dasbiswas, Kinjal; Ludwig, Nicholas B.; Han, Gang; Lee, Byeongdu; Vaikuntanathan, Suri; Talapin, Dmitri V.

    2017-02-01

    A colloidal solution is a homogeneous dispersion of particles or droplets of one phase (solute) in a second, typically liquid, phase (solvent). Colloids are ubiquitous in biological, chemical and technological processes, homogenizing highly dissimilar constituents. To stabilize a colloidal system against coalescence and aggregation, the surface of each solute particle is engineered to impose repulsive forces strong enough to overpower van der Waals attraction and keep the particles separated from each other. Electrostatic stabilization of charged solutes works well in solvents with high dielectric constants, such as water (dielectric constant of 80). In contrast, colloidal stabilization in solvents with low polarity, such as hexane (dielectric constant of about 2), can be achieved by decorating the surface of each particle of the solute with molecules (surfactants) containing flexible, brush-like chains. Here we report a class of colloidal systems in which solute particles (including metals, semiconductors and magnetic materials) form stable colloids in various molten inorganic salts. The stability of such colloids cannot be explained by traditional electrostatic and steric mechanisms. Screening of many solute–solvent combinations shows that colloidal stability can be traced to the strength of chemical bonding at the solute–solvent interface. Theoretical analysis and molecular dynamics modelling suggest that a layer of surface-bound solvent ions produces long-ranged charge-density oscillations in the molten salt around solute particles, preventing their aggregation. Colloids composed of inorganic particles in inorganic melts offer opportunities for introducing colloidal techniques to solid-state science and engineering applications.

  16. Chemical and structural changes in polyamide based organic-inorganic hybrid materials upon incorporation of SeS2O62- precursor

    NASA Astrophysics Data System (ADS)

    Krylova, V.; Dukstienė, N.; Žalenkienė, S.; Baltrusaitis, J.

    2017-01-01

    Composite organic-inorganic functional materials are of significant importance in various applications of science and technology. In this work, physicochemical characterization of such composite materials obtained after the exposure of polyamide PA 6 to K2SeS2O6 precursor solution was performed. Chalcogenized polymer surface was characterized using X-ray diffraction, infrared, and UV-vis spectroscopies while their bulk chemical analysis was performed using atomic absorption spectroscopy. Crystallite size was not found to change with the exposure to K2SeS2O6 precursor but PA 6 chain-chain separation decreased. Importantly, infrared and X-ray analyses showed chemical bonding taking place between the PA 6 and SeS2O62- ions via -NH- functional group. A distinct change in bandgap, Eg, value was observed in UV-vis spectra due to the presence of SeS2O62-, SeSO32- and Se2S2O62- ions formed via decomposition of the precursor material in acidic medium. After extended 4 h chalcogenation a distinct absorption due to the elemental selenium was also observed as obtained from Tauc plots.

  17. Scanning electron microscopy and X-ray microanalysis for chemical and morphological characterisation of the inorganic component of gunshot residue: selected problems.

    PubMed

    Brożek-Mucha, Zuzanna

    2014-01-01

    Chosen aspects of examinations of inorganic gunshot particles by means of scanning electron microscopy and energy dispersive X-ray spectrometry technique are presented. The research methodology of particles was worked out, which included a precise and repeatable procedure of the automatic detection and identification of particles as well as the representation of the obtained analytical data in the form of the frequencies of occurrence of particles of certain chemical or morphological class within the whole population of particles revealed in a specimen. On this basis, there were established relationships between the chemical and morphological properties of populations of particles and factors, such as the type of ammunition, the distance from the gun muzzle to the target, the type of a substrate the particles sediment on, and the time between shooting and collecting the specimens. Each of these aspects of examinations of particles revealed a great potential of being utilised in casework, while establishing various circumstances of shooting incidents leads to the reconstruction of the course of the studied incident.

  18. Scanning Electron Microscopy and X-Ray Microanalysis for Chemical and Morphological Characterisation of the Inorganic Component of Gunshot Residue: Selected Problems

    PubMed Central

    Brożek-Mucha, Zuzanna

    2014-01-01

    Chosen aspects of examinations of inorganic gunshot particles by means of scanning electron microscopy and energy dispersive X-ray spectrometry technique are presented. The research methodology of particles was worked out, which included a precise and repeatable procedure of the automatic detection and identification of particles as well as the representation of the obtained analytical data in the form of the frequencies of occurrence of particles of certain chemical or morphological class within the whole population of particles revealed in a specimen. On this basis, there were established relationships between the chemical and morphological properties of populations of particles and factors, such as the type of ammunition, the distance from the gun muzzle to the target, the type of a substrate the particles sediment on, and the time between shooting and collecting the specimens. Each of these aspects of examinations of particles revealed a great potential of being utilised in casework, while establishing various circumstances of shooting incidents leads to the reconstruction of the course of the studied incident. PMID:25025050

  19. Coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems in the eutrophic and turbid inner Changjiang (Yangtze River) Estuary

    NASA Astrophysics Data System (ADS)

    Zhai, W.-D.; Yan, X.-L.

    2015-04-01

    To better understand biogeochemical processes controlling CO2 dynamics in those eutrophic large-river estuaries and coastal lagoons, we investigated surface water carbonate system, nutrients, and relevant hydrochemical parameters in the inner Changjiang (Yangtze River) Estuary, covering its channel-like South Branch and the lagoon-like North Branch, shortly after a spring-tide period in April 2010. In the North Branch, with a water residence time of more than 2 months, biogeochemical additions of ammonium (7.4 to 65.7 μmol kg-1) and alkalinity (196 to 695 μmol kg-1) were detected along with high salinity of 4.5 to 17.4. In the South Branch upper-reach, unusual salinity values of 0.20 to 0.67 were detected, indicating spillover waters from the North Branch. The spillover waters enhanced the springtime Changjiang export fluxes of nutrients, dissolved inorganic carbon, and alkalinity. And they affected the biogeochemistry in the South Branch, by lowering water-to-air CO2 flux and continuing the nitrification reaction. In the North Branch, pCO2 was measured from 930 to 1518 μatm at the salinity range between 8 and 16, which was substantially higher than the South Branch pCO2 of 700 to 1100 μatm. Based on field data analyses and simplified stoichiometric equations, we suggest that the North Branch CO2 productions were quantified by biogeochemical processes combining organic matter decomposition, nitrification, CaCO3 dissolution, and acid-base reactions in the estuarine mixing zone. Although our study is subject to limited temporal and spatial coverage of sampling, we have demonstrated a procedure to quantificationally constrain net CO2 productions in eutrophic estuaries and/or coastal lagoons, by coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems.

  20. Chemically Selective Alternatives to Photoferroelectrics for Polarization-Enhanced Photocatalysis: The Untapped Potential of Hybrid Inorganic Nanotubes.

    PubMed

    Elliott, Joshua D; Poli, Emiliano; Scivetti, Ivan; Ratcliff, Laura E; Andrinopoulos, Lampros; Dziedzic, Jacek; Hine, Nicholas D M; Mostofi, Arash A; Skylaris, Chris-Kriton; Haynes, Peter D; Teobaldi, Gilberto

    2017-02-01

    Linear-scaling density functional theory simulation of methylated imogolite nanotubes (NTs) elucidates the interplay between wall-polarization, bands separation, charge-transfer excitation, and tunable electrostatics inside and outside the NT-cavity. The results suggest that integration of polarization-enhanced selective photocatalysis and chemical separation into one overall dipole-free material should be possible. Strategies are proposed to increase the NT polarization for maximally enhanced electron-hole separation.

  1. Novel fluorescence-based integrated sensor for chemical and biological agent detection

    NASA Astrophysics Data System (ADS)

    Frye-Mason, Greg; Leuschen, Martin; Wald, Lara; Paul, Kateri; Hancock, Lawrence F.; Fagan, Steve; Krouse, Justin; Hutchinson, Kira D.

    2004-12-01

    There is a renewed interest in the development of chemical and biological agent sensors due to the increased threat of weapons deployment by terrorist organizations and rogue states. Optically based sensors address the needs of military and homeland security forces in that they are reliable, rapidly deployed, and can provide continuous monitoring with little to no operator involvement. Nomadics has developed optically based chemical weapons sensors that utilize reactive fluorescent chromophores initially developed by Professor Tim Swager at MIT. The chromophores provide unprecedented sensitivity and selectivity toward toxic industrial chemicals and certain chemical weapon agents. The selectivity is based upon the reactivity of the G-class nerve agents (phosphorylation of acetylcholinesterase enzyme) that makes them toxic. Because the sensor recognizes the reactivity of strong electrophiles and not molecular weight, chemical affinity or ionizability, our system detects a specific class of reactive agents and will be able to detect newly developed or modified agents that are not currently known. We have recently extended this work to pursue a combined chemical/biological agent sensor system incorporating technologies based upon novel deep ultraviolet (UV) light emitting diodes (LEDs) developed out of the DARPA Semiconductor UV Optical Sources (SUVOS) program.

  2. Measurement of Organic and Inorganic Chemical Tracers for Source Apportionment of Tropospheric Aerosols Collected During the ACE-Asia Experiment

    NASA Astrophysics Data System (ADS)

    Schauer, J. J.; Park, J.; Duvall, R.; Bae, M.; Shafer, M. M.; Chuang, P.; Chuang, P.; Kim, Y. J.

    2001-12-01

    Naturally occurring dust and anthropogenic air pollutants are important contributors to tropospheric aerosols and impact air quality and the radiative balance of the Earth's atmosphere. In order to better understand the relationship between the origin, chemical composition and ultimate impact of Asian aerosols on climate forcing, aerosol samples were collected as part of the ACE-Asia experiment for detailed chemical analysis. Atmospheric particulate matter samples were collected from March 27, 2001 through May 6, 2001 at the ACE-Asia ground station located on Cheju Island, Korea. During this period, this region is impacted by anthropogenic air pollution emissions from highly urbanized region of Asia and by desert dust originating from northeastern Asia. As part of the experiment, atmospheric particulate matter samplers were also collected in urban and desert locations in Asia that represent regional sources of particulate matter in Asia. Size resolved aerosol samples were analyzed for trace metals by using microwave assisted-acid digestion and ICP-MS analysis, speciated organic compounds using solvent extraction and GC-MS analysis, as well as soluble ions and elemental and organic carbon (ECOC). These measurements provide fingerprints for source apportionment of the atmospheric particulate matter samples collected at the Cheju Island sampling site. The use of these chemical tracers for apportionment of wind-driven long range transported desert dust, local crustal derived dust, biogenically and anthropogenically derived sulfate, specific urban combustion source, and fossil fuel combustion will be presented.

  3. Excimer laser ablation mass spectrometry of inorganic solids: Chemical, matrix, and sampling effects on polyatomic ion yields

    SciTech Connect

    Gibson, J.K.

    1995-07-01

    Positive ions formed directly by excimer laser ablation in vacuum of several lanthanide (Ln) and transition metal solid materials---including Ln{sub 2}O{sub 3}, Ln{sub 2}S{sub 3}, LnF{sub 3}, Ta{sub 2}O{sub 5}, ZrO{sub 2}, TiO, and TiO{sub 2}---were identified by time-of-flight mass spectrometry. Variations in ion yields were investigated as a function of the composition of the precursor material, laser irradiance, and ion sampling delay after ablation. The compositions of the observed polyatomic ions reflected the distinctive chemistries of the metal constituents, but the ion yield distributions were not generally indicative of the particular chemical/valence constitution of the target material. For example, the yield of CeO{sup +} relative to Ce{sup +} was substantially greater from the trivalent cerium oxide, Ce{sub 2}(WO{sub 4}){sub 3}(s), than from tetravalent CeO{sub 2}(s). Observed ion distributions apparently reflected the chemical composition of the ablation plume and the degree of gas-phase recombination therein. The observed abundances of polyatomic ions were found to correlate well with their estimated bond strengths. Further obscuring the chemical composition of the progenitor, minor changes in ablation, and sampling parameters---especially irradiance and sampling delay---were often manifested as significant variations in relative ion intensities. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}

  4. Chemical warfare agent and biological toxin-induced pulmonary toxicity: could stem cells provide potential therapies?

    PubMed

    Angelini, Daniel J; Dorsey, Russell M; Willis, Kristen L; Hong, Charles; Moyer, Robert A; Oyler, Jonathan; Jensen, Neil S; Salem, Harry

    2013-01-01

    Chemical warfare agents (CWAs) as well as biological toxins present a significant inhalation injury risk to both deployed warfighters and civilian targets of terrorist attacks. Inhalation of many CWAs and biological toxins can induce severe pulmonary toxicity leading to the development of acute lung injury (ALI) as well as acute respiratory distress syndrome (ARDS). The therapeutic options currently used to treat these conditions are very limited and mortality rates remain high. Recent evidence suggests that human stem cells may provide significant therapeutic options for ALI and ARDS in the near future. The threat posed by CWAs and biological toxins for both civilian populations and military personnel is growing, thus understanding the mechanisms of toxicity and potential therapies is critical. This review will outline the pulmonary toxic effects of some of the most common CWAs and biological toxins as well as the potential role of stem cells in treating these types of toxic lung injuries.

  5. Synthetic biology: tools to design microbes for the production of chemicals and fuels.

    PubMed

    Seo, Sang Woo; Yang, Jina; Min, Byung Eun; Jang, Sungho; Lim, Jae Hyung; Lim, Hyun Gyu; Kim, Seong Cheol; Kim, Se Yeon; Jeong, Jun Hong; Jung, Gyoo Yeol

    2013-11-01

    The engineering of biological systems to achieve specific purposes requires design tools that function in a predictable and quantitative manner. Recent advances in the field of synthetic biology, particularly in the programmable control of gene expression at multiple levels of regulation, have increased our ability to efficiently design and optimize biological systems to perform designed tasks. Furthermore, implementation of these designs in biological systems highlights the potential of using these tools to build microbial cell factories for the production of chemicals and fuels. In this paper, we review current developments in the design of tools for controlling gene expression at transcriptional, post-transcriptional and post-translational levels, and consider potential applications of these tools.

  6. Chemical or Biological Terrorist Attacks: An Analysis of the Preparedness of Hospitals for Managing Victims Affected by Chemical or Biological Weapons of Mass Destruction

    PubMed Central

    Bennett, Russell L.

    2006-01-01

    The possibility of a terrorist attack employing the use of chemical or biological weapons of mass destruction (WMD) on American soil is no longer an empty threat, it has become a reality. A WMD is defined as any weapon with the capacity to inflict death and destruction on such a massive scale that its very presence in the hands of hostile forces is a grievous threat. Events of the past few years including the bombing of the World Trade Center in 1993, the Murrah Federal Building in Oklahoma City in 1995 and the use of planes as guided missiles directed into the Pentagon and New York’s Twin Towers in 2001 (9/11) and the tragic incidents involving twenty-three people who were infected and five who died as a result of contact with anthrax-laced mail in the Fall of 2001, have well established that the United States can be attacked by both domestic and international terrorists without warning or provocation. In light of these actions, hospitals have been working vigorously to ensure that they would be “ready” in the event of another terrorist attack to provide appropriate medical care to victims. However, according to a recent United States General Accounting Office (GAO) nationwide survey, our nation’s hospitals still are not prepared to manage mass causalities resulting from chemical or biological WMD. Therefore, there is a clear need for information about current hospital preparedness in order to provide a foundation for systematic planning and broader discussions about relative cost, probable effectiveness, environmental impact and overall societal priorities. Hence, the aim of this research was to examine the current preparedness of hospitals in the State of Mississippi to manage victims of terrorist attacks involving chemical or biological WMD. All acute care hospitals in the State were selected for inclusion in this study. Both quantitative and qualitative methods were utilized for data collection and analysis. Six hypotheses were tested. Using a

  7. Oxidative decontamination of chemical and biological warfare agents using L-Gel.

    PubMed

    Raber, Ellen; McGuire, Raymond

    2002-08-05

    A decontamination method has been developed using a single reagent that is effective both against chemical warfare (CW) and biological warfare (BW) agents. The new reagent, "L-Gel", consists of an aqueous solution of a mild commercial oxidizer, Oxone, together with a commercial fumed silica gelling agent, Cab-O-Sil EH-5. L-Gel is non-toxic, environmentally friendly, relatively non-corrosive, maximizes contact time because of its thixotropic nature, clings to walls and ceilings, and does not harm carpets or painted surfaces. The new reagent also addresses the most demanding requirements for decontamination in the civilian sector, including availability, low maintenance, ease of application and deployment by a variety of dispersal mechanisms, minimal training and acceptable expense. Experiments to test the effectiveness of L-Gel were conducted at Lawrence Livermore National Laboratory and independently at four other locations. L-Gel was tested against all classes of chemical warfare agents and against various biological warfare agent surrogates, including spore-forming bacteria and non-virulent strains of real biological agents. Testing showed that L-Gel is as effective against chemical agents and biological materials, including spores, as the best military decontaminants.

  8. The chemical biology of the persulfide (RSSH)/perthiyl (RSS·) redox couple and possible role in biological redox signaling.

    PubMed

    Bianco, Christopher L; Chavez, Tyler A; Sosa, Victor; Saund, Simran S; Nguyen, Q Nhu N; Tantillo, Dean J; Ichimura, Andrew S; Toscano, John P; Fukuto, Jon M

    2016-12-01

    The recent finding that hydropersulfides (RSSH) are biologically prevalent in mammalian systems has prompted further investigation of their chemical properties in order to provide a basis for understanding their potential functions, if any. Hydropersulfides have been touted as hyper-reactive thiol-like species that possess increased nucleophilicity and reducing capabilities compared to their thiol counterparts. Herein, using persulfide generating model systems, the ability of RSSH species to act as one-electron reductants has been examined. Not unexpectedly, RSSH is relatively easily oxidized, compared to thiols, by weak oxidants to generate the perthiyl radical (RSS·). Somewhat surprisingly, however, RSS· was found to be stable in the presence of both O2 and NO and only appears to dimerize. Thus, the RSSH/RSS· redox couple is readily accessible under biological conditions and since dimerization of RSS· may be a rare event due to low concentrations and/or sequestration within a protein, it is speculated that the general lack of reactivity of individual RSS· species may allow this couple to be utilized as a redox component in biological systems.

  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. One-pot biosynthesis of polymer-inorganic nanocomposites

    NASA Astrophysics Data System (ADS)

    Geng, Jiaqing; Yang, Dong; Zhu, Yong; Cao, Lichao; Jiang, Zhongyi; Sun, Yan

    2011-06-01

    A biological method is demonstrated to fabricate the polymer-inorganic nanocomposites (PINCs) utilizing bacterium as an efficient and versatile biofactory. Gluconacetobacter xylinum that can produce bacterial cellulose is incubated in the culture medium containing titanium or silica precursor. The PINCs can be acquired under the elaborate control of the culturing condition of G. xylinum, in which the formation of inorganic nanoparticles about several tens of nanometers in size synchronizes the fabrication of reticulated bacterial cellulose membrane composed of dense and finely branched nanofibers about 60-120 nm in diameter. The composition and chemical states, morphology, thermal stability of the inorganic nanoparticles, and nanocomposites were extensively characterized. A tentative mechanism for the formation of PINCs is proposed. It is hoped that this study may establish a generic platform toward facile and green synthesis of nanocomposite materials.

  11. Chitosan bio-based organic-inorganic hybrid aerogel microspheres.

    PubMed

    El Kadib, Abdelkrim; Bousmina, Mosto

    2012-07-02

    Recently, organic-inorganic hybrid materials have attracted tremendous attention thanks to their outstanding properties, their efficiency, versatility and their promising applications in a broad range of areas at the interface of chemistry and biology. This article deals with a new family of surface-reactive organic-inorganic hybrid materials built from chitosan microspheres. The gelation of chitosan (a renewable amino carbohydrate obtained by deacetylation of chitin) by pH inversion affords highly dispersed fibrillar networks shaped as self-standing microspheres. Nanocasting of sol-gel processable monomeric alkoxides inside these natural hydrocolloids and their subsequent CO(2) supercritical drying provide high-surface-area organic-inorganic hybrid materials. Examples including chitosan-SiO(2), chitosan-TiO(2), chitosan-redox-clusters and chitosan-clay-aerogel microspheres are described and discussed on the basis of their textural and structural properties, thermal and chemical stability and their performance in catalysis and adsorption.

  12. Regulatory impact analysis: Benefits and costs of proposed National Primary Drinking Water Regulations for inorganic chemicals. Phase 2, March 1989

    SciTech Connect

    Not Available

    1989-03-31

    National Primary Drinking Water Regulations are proposed for 30 synthetic organic chemicals, termed the SOCs. The document presents an analysis of the projected national costs and benefits associated with the proposed regulations in compliance with Executive Order 12291. It also includes an analysis of cost impacts on small water systems in compliance with the Regulatory Flexibility Act. The 30 SOCs fall into three groups. For a group of three 'miscellaneous' contaminants (acrylamide, epichlorohydrin, and PCBs), it is simply not possible to estimate occurrence due to a lack of data. Total national costs and benefits for all three are not anticipated to be very significant.

  13. "Toward High School Biology": Helping Middle School Students Understand Chemical Reactions and Conservation of Mass in Nonliving and Living Systems

    ERIC Educational Resources Information Center

    Herrmann-Abell, Cari F.; Koppal, Mary; Roseman, Jo Ellen

    2016-01-01

    Modern biology has become increasingly molecular in nature, requiring students to understand basic chemical concepts. Studies show, however, that many students fail to grasp ideas about atom rearrangement and conservation during chemical reactions or the application of these ideas to biological systems. To help provide students with a better…

  14. Report from the Third Annual Symposium of the RIKEN-Max Planck Joint Research Center for Systems Chemical Biology.

    PubMed

    Brunschweiger, Andreas

    2014-08-15

    The third Annual Symposium of the RIKEN-Max Planck Joint Research Center for Systems Chemical Biology was held at Ringberg castle, May 21-24, 2014. At this meeting 45 scientists from Japan and Germany presented the latest results from their research spanning a broad range of topics in chemical biology and glycobiology.

  15. Validation of N-myristoyltransferase as an antimalarial drug target using an integrated chemical biology approach

    PubMed Central

    Wright, Megan H.; Clough, Barbara; Rackham, Mark D.; Rangachari, Kaveri; Brannigan, James A.; Grainger, Munira; Moss, David K.; Bottrill, Andrew R.; Heal, William P.; Broncel, Malgorzata; Serwa, Remigiusz A.; Brady, Declan; Mann, David J.; Leatherbarrow, Robin J.; Tewari, Rita; Wilkinson, Anthony J.; Holder, Anthony A.; Tate, Edward W.

    2016-01-01

    Malaria is an infectious disease caused by parasites of the genus Plasmodium that inflicts approximately one million deaths per annum worldwide. Chemical validation of new antimalarial targets is urgently required in view of rising resistance to current drugs. One such putative target is the enzyme N-myristoyltransferase (NMT), which catalyzes N-myristoylation of protein substrates. Here we report an integrated chemical biology approach to explore protein myristoylation in the major human parasite P. falciparum, combining chemical proteomic tools for identification of the myristoylated and glycosylphosphatidylinositol-anchored proteome with selective small molecule NMT inhibitors. We demonstrate that NMT is an essential and chemically tractable target in malaria parasites both in vitro and in vivo, and show that selective inhibition of N-myristoylation leads to catastrophic and irreversible failure to assemble the inner membrane complex, a critical subcellular organelle in the parasite life cycle. Our studies provide the basis for development of new antimalarials targeting NMT. PMID:24451586

  16. An overview of biological markers of exposure to chemical warfare agents.

    PubMed

    Black, Robin M

    2008-01-01

    An overview is given of biological markers of exposure to chemical warfare agents. Metabolites, protein, and/or DNA adducts have been identified for most nerve agents and vesicants and validated in experimental animals or in a small number of human exposures. For several agents, metabolites derived from hydrolysis are unsatisfactory biomarkers of exposure because of background levels in the human population. These are assumed to result from environmental exposure to commercial products that contain these hydrolysis products or chemicals that are metabolized to them. In these cases, metabolites derived from glutathione pathways, or covalent adducts with proteins or DNA, provide more definitive biomarkers. Biomarkers for cyanide and phosgene are unsatisfactory as indicators of chemical warfare exposure because of other sources of these chemicals or their metabolites.

  17. Treatment of wastewater containing acid rose red dye by biologically aerated filter after chemical oxidation.

    PubMed

    Wang, X; Gu, X; Zhou, X; Wang, W; Lin, D

    2007-08-01

    Combined processes of pre-chemical oxidation and biological aerated filter (BAF) were used to treat wastewater containing non-biodegradable acid rose red dye. Advance oxidation processes (AOPs) of ozone and Fenton reagent were applied for pre-chemical oxidation, which reduced the degree of color and organic matter simultaneously increasing the biodegradability of the wastewater. The majority of the organic matter was removed by BAF. When using ozone as pre-chemical oxidation, the operation is simpler. The combined processes of AOPs, including ozone and Fenton reagent, followed by BAF reduced the color and chemical oxygen demand (COD) to less than 20 degrees and 40 mg l(-1), respectively from the influent concentration of about 4000 degree color and 300 mg l(-1) COD. The effluent water quality could meet the required standard for grey water reuses.

  18. Natural products-prompted chemical biology: phenotypic screening and a new platform for target identification.

    PubMed

    Kakeya, Hideaki

    2016-05-04

    Covering: 1993 to 2016The exploitation of small molecules from natural sources, such as microbial metabolites, has contributed to the discovery of not only new drugs but also new research tools for chemical biology. My research team has discovered several novel bioactive small molecules using in vivo cell-based phenotypic screening, and has investigated their modes of action using chemical genetics and chemical genomics. This highlight focuses on our recent discoveries and chemical genetics approaches for bioactive microbial metabolites that target cancer cells, the cancer microenvironment and cell membrane signalling. In addition, the development of two new platforms, 5-sulfonyl tetrazole-based and thiourea-modified amphiphilic lipid-based probe technologies, to identify the cellular targets of these molecules is also discussed.

  19. Chemical and biological warfare: Biochemistry, therapy, and treatment. (Latest citations from the NTIS database). Published Search

    SciTech Connect

    Not Available

    1993-07-01

    The bibliography contains citations concerning biochemistry, therapy, and treatment of the effects of military chemical and biological warfare agents. References include surveys and studies of immunizing agents and drugs, the efficacy of these drugs, and the effect of the drugs on the patient. Also included are biochemical studies, assay techniques, and antidote development, some of which is supported by animal studies. Citations concerning detection and warning, defoliants, protection, biology and toxicology, and general studies are covered in separate bibliographies. (Contains a minimum of 187 citations and includes a subject term index and title list.)

  20. The biological activities and chemical composition of Pereskia species (Cactaceae)--a review.

    PubMed

    Pinto, Nícolas de Castro Campos; Scio, Elita

    2014-09-01

    The exploration of nature as a source of sustainable, novel bioactive substances continues to grow as natural products play a significant role in the search for new therapeutic and agricultural agents. In this context, plants of the genus Pereskia (Cactaceae) have been studied for their biological activities, and are evolving as an interesting subject in the search for new, bioactive compounds. These species are commonly used as human foodstuffs and in traditional medicine to treat a variety of diseases. This review focuses on the bioactivity and chemical composition of the genus Pereskia, and aims to stimulate further studies on the chemistry and biological potential of the genus.

  1. Ion mobility-mass spectrometry strategies for untargeted systems, synthetic, and chemical biology

    PubMed Central

    May, Jody C.; Goodwin, Cody R.; McLean, John A.

    2014-01-01

    Contemporary strategies that concentrate on only one or a handful of molecular targets limits the utility of the information gained for diagnostic and predictive purposes. Recent advances in the sensitivity, speed, and precision of measurements obtained from ion mobility coupled to mass spectrometry (IM-MS) have accelerated the utility of IM-MS in untargeted, discovery-driven studies in biology. Perhaps most evident is the impact that such wide-scale discovery capabilities have yielded in the areas of systems, synthetic, and chemical biology, where the need for comprehensive, hypothesis-driving studies from multidimensional and unbiased data is required. PMID:25462629

  2. Subcellular Redox Targeting: Bridging in Vitro and in Vivo Chemical Biology.

    PubMed

    Long, Marcus J C; Poganik, Jesse R; Ghosh, Souradyuti; Aye, Yimon

    2017-03-17

    Networks of redox sensor proteins within discrete microdomains regulate the flow of redox signaling. Yet, the inherent reactivity of redox signals complicates the study of specific redox events and pathways by traditional methods. Herein, we review designer chemistries capable of measuring flux and/or mimicking subcellular redox signaling at the cellular and organismal level. Such efforts have begun to decipher the logic underlying organelle-, site-, and target-specific redox signaling in vitro and in vivo. These data highlight chemical biology as a perfect gateway to interrogate how nature choreographs subcellular redox chemistry to drive precision redox biology.

  3. Chemical and Biological Impacts of Ocean Acidification Along the West Coast of North America

    NASA Astrophysics Data System (ADS)

    Feely, R. A.; Alin, S. R.; Carter, B.; Bednarsek, N.

    2015-12-01

    The continental shelf region off the Washington-Oregon-California coast is seasonally exposed to water with a low aragonite saturation state by coastal upwelling of CO2-rich waters. To date, the spatial and temporal distribution of anthropogenic CO2 (Canth) contribution to the CO2-rich waters is largely unknown. Here we use an adaptation of the linear regression approach described in Feely et al. (2008) to utilize the GO-SHIP Repeat Hydrography data set from the northeast Pacific to establish an annually updated relationship between Canth and potential density. This relationship was then used with the NOAA Ocean Acidification Program West Coast cruise data sets from 2007, 2011, 2012 and 2013 to determine the spatial variations of Canth in the upwelled water. Our results show large spatial differences in Canth in surface waters along the coast with the lowest values (40-45 μmol kg-1) in strong upwelling regions of off northern California and southern Oregon and higher values (50-70 μmol kg-1) to the north and south of this region. Canth contributes an average of about 70 % of the increased amount of dissolved inorganic carbon in the upwelled waters at the surface relative to what would be expected from physical circulation and exchange with a preindustrial atmosphere alone. In contrast, Canth contributes an average of about 31%, and 16% of the increased amount of dissolved inorganic carbon at 50 m depth, and at 100 m depth respectively. The remaining contributions are either due to respiration processes in the water that was upwelled and transported to coastal regions or respiration processes that occurs locally during the course of the upwelling season. The uptake of Canth has caused the aragonite saturation horizon to shoal by approximately 30-50 m since preindustrial period so that the undersaturated waters are well within the regions of the continental shelf that affect the biological communities.

  4. [The chemical action of gun powder gases on biological tissues in a point-blank shot].

    PubMed

    Popov, V L; Isakov, V D; Babakhanian, R V; Karnasevich, Iu A

    1992-01-01

    Chemical effect of gun powder gas on the biologic tissues manifests by red-brown staining of the tissues, mainly at the expense of methemoglobin and sulfhemoglobin. Scarlet staining of the tissues at the edges of gun-shot wounds is not a specific marker of a shot made from a short distance; it may emerge several hours after wounding at the expense of hydroxy-hemoglobin and is not at all related to the chemical effect of gun powder gas. The conditions conducive to scarlet staining are an open wound permitting free oxygenation by air oxygen and hemoglobin transfer from the injured red cells into blood plasma and adjacent tissues.

  5. The chemical composition and biological properties of coconut (Cocos nucifera L.) water.

    PubMed

    Yong, Jean W H; Ge, Liya; Ng, Yan Fei; Tan, Swee Ngin

    2009-12-09

    Coconut water (coconut liquid endosperm), with its many applications, is one of the world's most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water.

  6. Peptide and RNA contributions to iron-sulphur chemical gardens as life's first inorganic compartments, catalysts, capacitors and condensers.

    PubMed

    McGlynn, Shawn E; Kanik, Isik; Russell, Michael J

    2012-06-28

    Hydrothermal chimneys and compartments comprising transition metal sulphides and associated minerals have been proposed as likely locations for the beginnings of life. In laboratory simulations of off-axis alkaline springs, it is shown that the interaction of a simulated alkaline sulphide-bearing submarine vent solution with a primeval anoxic iron-bearing ocean leads to the formation of chimney structures reminiscent of chemical gardens. These chimneys display periodicity in their deposition and exhibit diverse morphologies and mineralogies, affording the possibilities of catalysis and molecular sequestration. The addition of peptides and RNA to the alkaline solution modifies the elemental stoichiometry of the chimneys-perhaps indicating the very initial stage of the organic takeover on the way to living cells by charged organic polymers potentially synthesized in this same environment.

  7. A study of the physical-chemical mechanisms and variables which affect the transport of inorganic and organic heterogeneous systems

    SciTech Connect

    Anderson, M.A.; Zeltner, W.A.

    1990-07-01

    In order to model transport of dissolved ions in subsurface environments, one should understand how these ions interact with solid phase adsorbents. Our primary goal has been investigating the reaction mechanisms which affect microcontaminant partitioning between aqueous solutions and solid phase adsorbents, using goethite ({alpha}-FeOOH) as a model adsorbent. Cylindrical internal reflection -- Fourier transform infrared (CIR-FTIR) spectroscopy has been developed as the primary technique for this study. Wet chemical adsorption studies, acoustophoresis and electrophoretic mobility have been used to obtain supporting information as needed. Phenol and o-nitrophenol did not adsorb to goethite. Benzoate, phthalate and p-hydroxybenzoate all adsorbed via a bidentate mechanism to two adjacent iron atoms, while salicylate and 2,4-dihydroxybenzoate formed a chelate complex to single iron atoms. Phosphate adsorption was predominately bidentate.

  8. Morphology and chemical composition analysis of inorganic nanosheets by the field-emission scanning electron microscope system.

    PubMed

    Li, Qinghui; Ono, Yuki; Homma, Yoshikazu; Nakai, Izumi; Fukuda, Katsutoshi; Sasaki, Takayoshi; Tanaka, Keiichi; Nakayama, Satoshi

    2009-01-01

    Nanosheets can be used as building blocks to fabricate versatile nanostructured materials. In this paper, morphology of the Cs(4)W(11)O(36) and Nb(3)O(8) and TaO(3) sheets with different layers are analyzed by different field-emission scanning electron microscopes (FE-SEMs). Chemical composition of the single-layered Cs(4)W(11)O(36) with thickness of about 2 nm, and multilayered Nb(3)O(8) nanosheets with thickness of less than 14 nm are analyzed by both the Si(Li) solid-state detector and transition edge sensor (TES) microcalorimeter, successfully. The effects of energy resolution, accelerating voltage and substrate on the quantitative analysis are discussed briefly.

  9. Chemical characterization and biological activity of Macfadyena unguis-cati (Bignoniaceae).

    PubMed

    Duarte, D S; Dolabela, M F; Salas, C E; Raslan, D S; Oliveiras, A B; Nenninger, A; Wiedemann, B; Wagner, H; Lombardi, J; Lopes, M T

    2000-03-01

    Macfadyena unguis-cati (L.) has been widely used in folk medicine as an anti-inflammatory, antimalarial and antivenereal. The purpose of this study was to chemically characterize the main plant components, and to evaluate the biological properties of some of the fractions derived from leaves (MACb) and liana (MACa) of this plant. Chemical characterization allowed the identification of the compounds corymboside, vicenin-2, quercitrin, chlorogenic acid, isochlorogenic acid, lupeol, beta-sitosterol, beta-sitosterylglucoside, allantoin and lapachol. The biological screening of fractions and/or purified substances derived from fractions revealed antitumoral and antitrypanosomal activities in fractions MACa/lapachol and MACb/MACb21, respectively. The anti-lipoxygenase and anti-cyclooxygenase effect seen in fractions MACa and MACb showed a partial correlation with the anti-inflammatory property attributed to this plant.

  10. Total-Internal-Reflection Platforms for Chemical and Biological Sensing Applications

    NASA Astrophysics Data System (ADS)

    Sapsford, Kim E.

    Sensing platforms based on the principle of total internal reflection (TIR) represent a fairly mature yet still expanding and exciting field of research. Sensor development has mainly been driven by the need for rapid, stand-alone, automated devices for application in the fields of clinical diagnosis and screening, food and water safety, environmental monitoring, and chemical and biological warfare agent detection. The technologies highlighted in this chapter are continually evolving, taking advantage of emerging advances in microfabrication, lab-on-a-chip, excitation, and detection techniques. This chapter describes many of the underlying principles of TIR-based sensing platforms and additionally focusses on planar TIR fluorescence (TIRF)-based chemical and biological sensors.

  11. Plasma flame for mass purification of contaminated air with chemical and biological warfare agents

    SciTech Connect

    Uhm, Han S.; Shin, Dong H.; Hong, Yong C.

    2006-09-18

    An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22 cm diameter and 30 cm length, purifies an airflow rate of 5000 lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.

  12. Integrated chemical and biological assessment of contaminant impacts in selected European coastal and offshore marine areas.

    PubMed

    Hylland, Ketil; Robinson, Craig D; Burgeot, Thierry; Martínez-Gómez, Concepción; Lang, Thomas; Svavarsson, Jörundur; Thain, John E; Vethaak, A Dick; Gubbins, Mattew J

    2017-03-01

    This paper reports a full assessment of results from ICON, an international workshop on marine integrated contaminant monitoring, encompassing different matrices (sediment, fish, mussels, gastropods), areas (Iceland, North Sea, Baltic, Wadden Sea, Seine estuary and the western Mediterranean) and endpoints (chemical analyses, biological effects). ICON has demonstrated the use of a framework for integrated contaminant assessment on European coastal and offshore areas. The assessment showed that chemical contamination did not always correspond with biological effects, indicating that both are required. The framework can be used to develop assessments for EU directives. If a 95% target were to be used as a regional indicator of MSFD GES, Iceland and offshore North Sea would achieve the target using the ICON dataset, but inshore North Sea, Baltic and Spanish Mediterranean regions would fail.

  13. Water-stable organic transistors and their application in chemical and biological sensors

    PubMed Central

    Roberts, Mark E.; Mannsfeld, Stefan C. B.; Queraltó, Núria; Reese, Colin; Locklin, Jason; Knoll, Wolfgang; Bao, Zhenan

    2008-01-01

    The development of low-cost, reliable sensors will rely on devices capable of converting an analyte binding event to an easily read electrical signal. Organic thin-film transistors (OTFTs) are ideal for inexpensive, single-use chemical or biological sensors because of their compatibility with flexible, large-area substrates, simple processing, and highly tunable active layer materials. We have fabricated low-operating voltage OTFTs with a cross-linked polymer gate dielectric, which display stable operation under aqueous conditions over >104 electrical cycles using the p-channel semiconductor 5,5′-bis-(7-dodecyl-9H-fluoren-2-yl)-2,2′-bithiophene (DDFTTF). OTFT sensors were demonstrated in aqueous solutions with concentrations as low as parts per billion for trinitrobenzene, methylphosphonic acid, cysteine, and glucose. This work demonstrates of reliable OTFT operation in aqueous media, hence opening new possibilities of chemical and biological sensing with OTFTs. PMID:18711145

  14. Physical, chemical, and biological data for selected streams in Chester County, Pennsylvania, 1995-97

    USGS Publications Warehouse

    Reif, Andrew G.

    2000-01-01

    Physical, chemical, and biological data were collected at 51 sampling sites in Chester County, Pa., from 1970 through 1997 as part of the Stream Conditions of Chester County Program. This report presents data collected from 43 sites from 1995 through 1997 that constitute a continuation of the program. Physical data include water temperature, instantaneous stream discharge, pH, alkalinity, specific conductance, and dissolved oxygen. Chemical data collected include laboratory determinations of nutrients and major ions in whole water samples and selected metals, pesticides, gross polychlorinated biphenyls (PCB's), gross polychlorinated napthalenes (PCN's), and total carbon in stream-sediment samples. The biological data include benthic-macroinvertebrate populations. The data are presented without interpretation. Chester County is undergoing urbanization as agricultural land is converted to residential developments, commercial areas, and industrial and corporate parks. The major goal of the Stream Conditions of Chester County Program is to further the understanding of stream changes in response to urbanization.

  15. Plasma flame for mass purification of contaminated air with chemical and biological warfare agents

    NASA Astrophysics Data System (ADS)

    Uhm, Han S.; Shin, Dong H.; Hong, Yong C.

    2006-09-01

    An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22cm diameter and 30cm length, purifies an airflow rate of 5000lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.

  16. Physical, chemical, and biological data for selected streams in Chester County, Pennsylvania, 1969-80

    USGS Publications Warehouse

    Moore, C.R.

    1989-01-01

    This report presents physical, chemical, and biological data collected at 50 sampling sites on selected streams in Chester County, Pennsylvania from 1969 to 1980. The physical data consist of air and water temperature, stream discharge, suspended sediment, pH, specific conductance, and dissolved oxygen. The chemical data consist of laboratory determinations of total nutrients, major ions, and trace metals. The biological data consist of total coliform, fecal coliform, and fecal streptococcus bacteriological analyses, and benthicmacroinvertebrate population analyses. Brillouin's diversity index, maximum diversity, minimum diversity, and evenness for each sample, and median and mean Brilloiuin's diversity index, standard deviation, and standard error of the mean were calculated for the benthic-macroinvertebrate data for each site.

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

    PubMed

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

    2005-01-01

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

  18. Chemical and biological work-related risks across occupations in Europe: a review

    PubMed Central

    2014-01-01

    Background Work-related health inequalities are determined to some extent by an unequal exposure to chemical and biological risk factors of disease. Although their potential economic burden in the European Union (EU-25) might be substantial, comprehensive reviews focusing on the distribution of these risks across occupational groups are limited. Thus, the main objective of this review is to provide a synopsis of the exposure to chemical and biological hazards across occupational groups. In addition, main industrial applications of hazardous substances are identified and some epidemiological evidence is discussed regarding societal costs and incidence rates of work-related diseases. Methods Available lists of carcinogens, sensitisers, mutagens, reprotoxic substances and biological hazards were consulted. For each work-related hazard the main industrial application was identified in order to assess which ISCO occupational groups may be associated with direct exposure. Where available, information on annual tonnage production, risk assessment of the substances and pathogens, and other relevant data were collected and reported. Results Altogether 308 chemical and biological hazards were identified which may account to at least 693 direct exposures. These hazards concentrate on the following major occupational groups: technicians (ISCO 3), operators (ISCO 8), agricultural workers (ISCO 6) and workers in elementary occupations (ISCO 9). Common industrial applications associated with increased exposure rates relate among others to: (1) production or application of pigments, resins, cutting fluids, adhesives, pesticides and cleaning products, (2) production of rubber, plastics, textiles, pharmaceuticals and cosmetics, and (3) in agriculture, metallurgy and food processing industry, Societal costs of the unequal distribution of chemical and biological hazards across occupations depend on the corresponding work-related diseases and may range from 2900 EUR to 126000 EUR per

  19. Safe management of mass fatalities following chemical, biological, and radiological incidents.

    PubMed

    Baker, David J; Jones, Kelly A; Mobbs, Shelly F; Sepai, Ovnair; Morgan, Dilys; Murray, Virginia S G

    2009-01-01

    Contaminated mass fatalities following the release of chemical, biological, or radiological agents pose a potential major health hazard. A United Kingdom government investigation has identified a number of areas of risk. This paper presents an outline of the findings of the study and describes specific pathways for the management of contaminated and non-contaminated fatalities. Factors determining the choice between cremation and burial are discussed. Effective decontamination remains a neglected area of study for both fatalities and casualties.

  20. 2006 Joint Chemical Biological, Radiological and Nuclear (CBRN) Conference and Exhibition

    DTIC Science & Technology

    2006-06-28

    Systems approach to the detection of chemical and biological agents with a focus on genetically engineered organisms ( GMOs )/genetically engineered...Need Your Input! What’s Good / What’s Bad ? What Common Interfaces Make Sense? How Do we Drive Technology to Meet Future Concepts? Joint Program...USSTRATCOM and DTRA Responsibilities • Programmatic Response • The Future – Our People Outline 3 Combating WMD Strategic Framework 4 Guidance for