Simultaneous determination of equivalence volumes and acid dissociation constants from potentiometric titration data.

Science.gov (United States)

Papanastasiou, G; Ziogas, I

1995-06-01

New iterative methods for analysis of potentiometric titration data of (a) mixtures of weak monoprotic acids with their conjugate bases, (b) solutions of polyprotic (di- and triprotic) acids, and (c) mixtures of two diprotic acids are presented. These methods, using data exclusively resulting from the acidic region of the titration curve permits the accurate determination of the analytical concentration of one or more acids even if the titration is stopped well before the end point of the titration. For the titration of a solution containing a conjugate acid/base pair, the proposed procedure enables the extraction of the initial composition of the mixture, as well as the dissociation constant of the concerned acid. Thus, it is possible by this type of analysis to distinguish whether a weak acid has been contaminated by a strong base and define the extent of the contamination. On the other hand, for the titration of polyprotic acids, the proposed approach enables the extraction of the accurate values of the equivalence volume and the dissociation constants K(i) even when the ionization stages overlap. Finally, for the titration of a mixture of two diprotic acids the proposed procedure enables the determination of the composition of the mixture even if the sum of the concentrations of the acids is not known. This method can be used in the analysis of solutions containing two diastereoisomeric forms of a weak diprotic acid. The test of the proposed procedures by means of ideal and Monte Carlo simulated data revealed that these methods are fairly applicable even when the titration data are considerably obscured by 'noise' or contain an important systematic error. The proposed procedures were also successfully applied to experimental titration data.

An insight into the biological activities of heterocyclic-fatty acid hybrid molecules.

Science.gov (United States)

Venepally, Vijayendar; Reddy Jala, Ram Chandra

2017-12-01

Heterocyclic compounds are the interesting core structures for the development of new bioactive compounds. Fatty acids are derived from renewable raw materials and exhibit various biological activities. Several researchers are amalgamating these two bioactive components to yield bioactive hybrid molecules with some desirable features. Heterocyclic-fatty acid hybrid derivatives are a new class of heterocyclic compounds with a broad range of biological activities and significance in the field of medicinal chemistry. Over the last few years, many research articles emphasized the significance of heterocyclic-fatty acid hybrid derivatives. The present review article focuses the developments in designing and biological evaluation of heterocyclic-fatty acid hybrid molecules. Copyright © 2017. Published by Elsevier Masson SAS.

The analysis for energy distribution and biological effects of the clusters from electrons in the tissue equivalent material

International Nuclear Information System (INIS)

Zhang Wenzhong; Guo Yong; Luo Yisheng; Wang Yong

2004-01-01

Objective: To study energy distribution of the clusters from electrons in the tissue equivalent material, and discuss the important aspects of these clusters on inducing biological effects. Methods: Based on the physical mechanism for electrons interacting with tissue equivalent material, the Monte Carlo (MC) method was used. The electron tracks were lively simulated on an event-by-event (ionization, excitation, elastic scattering, Auger electron emission) basis in the material. The relevant conclusions were drawn from the statistic analysis of these events. Results: The electrons will deposit their energy in the form (30%) of cluster in passing through tissue equivalent material, and most clusters (80%) have the energy amount of more than 50 eV. The cluster density depends on its diameter and energy of electrons, and the deposited energy in the cluster depends on the type and energy of radiation. Conclusion: The deposited energy in cluster is the most important factor in inducing all sort of lesions on DNA molecules in tissue cells

Automated GC-MS analysis of free amino acids in biological fluids.

Science.gov (United States)

Kaspar, Hannelore; Dettmer, Katja; Gronwald, Wolfram; Oefner, Peter J

2008-07-15

A gas chromatography-mass spectrometry (GC-MS) method was developed for the quantitative analysis of free amino acids as their propyl chloroformate derivatives in biological fluids. Derivatization with propyl chloroformate is carried out directly in the biological samples without prior protein precipitation or solid-phase extraction of the amino acids, thereby allowing automation of the entire procedure, including addition of reagents, extraction and injection into the GC-MS. The total analysis time was 30 min and 30 amino acids could be reliably quantified using 19 stable isotope-labeled amino acids as internal standards. Limits of detection (LOD) and lower limits of quantification (LLOQ) were in the range of 0.03-12 microM and 0.3-30 microM, respectively. The method was validated using a certified amino acid standard and reference plasma, and its applicability to different biological fluids was shown. Intra-day precision for the analysis of human urine, blood plasma, and cell culture medium was 2.0-8.8%, 0.9-8.3%, and 2.0-14.3%, respectively, while the inter-day precision for human urine was 1.5-14.1%.

Examination of Signatures of Recent Positive Selection on Genes Involved in Human Sialic Acid Biology.

Science.gov (United States)

Moon, Jiyun M; Aronoff, David M; Capra, John A; Abbot, Patrick; Rokas, Antonis

2018-03-28

Sialic acids are nine carbon sugars ubiquitously found on the surfaces of vertebrate cells and are involved in various immune response-related processes. In humans, at least 58 genes spanning diverse functions, from biosynthesis and activation to recycling and degradation, are involved in sialic acid biology. Because of their role in immunity, sialic acid biology genes have been hypothesized to exhibit elevated rates of evolutionary change. Consistent with this hypothesis, several genes involved in sialic acid biology have experienced higher rates of non-synonymous substitutions in the human lineage than their counterparts in other great apes, perhaps in response to ancient pathogens that infected hominins millions of years ago (paleopathogens). To test whether sialic acid biology genes have also experienced more recent positive selection during the evolution of the modern human lineage, reflecting adaptation to contemporary cosmopolitan or geographically-restricted pathogens, we examined whether their protein-coding regions showed evidence of recent hard and soft selective sweeps. This examination involved the calculation of four measures that quantify changes in allele frequency spectra, extent of population differentiation, and haplotype homozygosity caused by recent hard and soft selective sweeps for 55 sialic acid biology genes using publicly available whole genome sequencing data from 1,668 humans from three ethnic groups. To disentangle evidence for selection from confounding demographic effects, we compared the observed patterns in sialic acid biology genes to simulated sequences of the same length under a model of neutral evolution that takes into account human demographic history. We found that the patterns of genetic variation of most sialic acid biology genes did not significantly deviate from neutral expectations and were not significantly different among genes belonging to different functional categories. Those few sialic acid biology genes that

A simplified equivalent circuit model for simulation of Pb-acid batteries at load for energy storage application

Energy Technology Data Exchange (ETDEWEB)

Zhu, Wenhua H.; Zhu Ying [Center for Microfibrous Materials, Department of Chemical Engineering, 212 Ross Hall, Auburn University, AL 36849-5127 (United States); Tatarchuk, Bruce J., E-mail: brucet@eng.auburn.edu [Center for Microfibrous Materials, Department of Chemical Engineering, 212 Ross Hall, Auburn University, AL 36849-5127 (United States)

2011-08-15

Highlights: {yields} Pb-acid battery is reexamined in electrode structure and capacitance enhancement. {yields} Pb-acid batteries were tested through the electrochemical impedance at loads. {yields} Electrode behaviors are evaluated by simulation using an equivalent circuit model. {yields} A defective and a failed Pb-acid battery was used in non-destructive analysis. {yields} Potential applications are for power reserve and sustainable electricity storage. - Abstract: Three main types of battery chemistries in consideration for vehicle applications are Pb-acid, nickel-metal hydride, and lithium-ion batteries. Lead-acid batteries are widely used in traditional automotive applications for many years. Higher voltage, high-rate discharge capability, good specific energy, lower temperature performance, lower thermal management requirement, and low-cost in both manufacturing and recycling are the advantages of the rechargeable battery. Disadvantages of the lead-acid battery are: weight concerns of lead metal (lower energy density and lower power density) and limited cycle-life (especially in deep-cycle duties). If two major disadvantages have been significantly changed to a proper state to compete with other battery chemistries, the Pb-acid battery is still a good candidate in considering of cost/performance ratio. The lead-acid battery is always a good power source for fast starting of cold vehicles, for recharging from either a stop-start braking system, or for a charge from the engine itself, which consumes battery energy or stores electricity back into chemical energy. The main reasons for reexamining this battery chemistry are cost-savings and life-cycling considerations upon advances in electrode structure design and enhancement of capacitance behavior inside the battery pack. Several Pb-acid batteries were evaluated and tested through a unique method, i.e., the electrochemical impedance method at different loads, in order to characterize and further understand the

A simplified equivalent circuit model for simulation of Pb-acid batteries at load for energy storage application

International Nuclear Information System (INIS)

Zhu, Wenhua H.; Zhu Ying; Tatarchuk, Bruce J.

2011-01-01

Highlights: → Pb-acid battery is reexamined in electrode structure and capacitance enhancement. → Pb-acid batteries were tested through the electrochemical impedance at loads. → Electrode behaviors are evaluated by simulation using an equivalent circuit model. → A defective and a failed Pb-acid battery was used in non-destructive analysis. → Potential applications are for power reserve and sustainable electricity storage. - Abstract: Three main types of battery chemistries in consideration for vehicle applications are Pb-acid, nickel-metal hydride, and lithium-ion batteries. Lead-acid batteries are widely used in traditional automotive applications for many years. Higher voltage, high-rate discharge capability, good specific energy, lower temperature performance, lower thermal management requirement, and low-cost in both manufacturing and recycling are the advantages of the rechargeable battery. Disadvantages of the lead-acid battery are: weight concerns of lead metal (lower energy density and lower power density) and limited cycle-life (especially in deep-cycle duties). If two major disadvantages have been significantly changed to a proper state to compete with other battery chemistries, the Pb-acid battery is still a good candidate in considering of cost/performance ratio. The lead-acid battery is always a good power source for fast starting of cold vehicles, for recharging from either a stop-start braking system, or for a charge from the engine itself, which consumes battery energy or stores electricity back into chemical energy. The main reasons for reexamining this battery chemistry are cost-savings and life-cycling considerations upon advances in electrode structure design and enhancement of capacitance behavior inside the battery pack. Several Pb-acid batteries were evaluated and tested through a unique method, i.e., the electrochemical impedance method at different loads, in order to characterize and further understand the improved electrode

Changes in amino acid profile of alfalfa silage preserved by chemical and biological additives during fermentation

Directory of Open Access Journals (Sweden)

Jaroslava Michálková

2009-01-01

Full Text Available Changes in amino acid profile of alfalfa silage preserved with chemical or biological additives were studied in fresh and wilted silage. The chemical additive was formic acid and the biological additive consisted of Lactobacillus rhamnosus, L. plantarum, L. brevis, L. buchneri and Pediococcus pentosaceus. Second cut alfalfa (Medicago sativa L. was harvested at the bloom stage, ensiled in mini silos (15 dm3 and fermented at 20–23 °C for 12 weeks. The dry matter of the fresh silage was 228 g . kg−1 and 281.6 g . kg−1 for the wilted before ensiling. The amino acid content was estimated by using an automatic amino acid analyzer AAA (INGOS Prague. The results of the experiments indicated that amino acid breakdown was inhibited by increased dry matter and the use of chemical and biological additive. Additionally, the content of amino acids was found to change in relation to the degree of wilting and formic acid treatment yielded the lowest amino acid breakdown. The amino acid breakdown was also reduced by biological preservative especially in the silage with a higher level of dry matter content.

Synthesis, biological distribution and radiation dosimetry of Te-123m analogues of hexadecenoic acid

International Nuclear Information System (INIS)

Basmadjian, G.P.; Ice, R.D.; Mills, S.L.

1982-01-01

The synthesis and biological distribution of four Te-123m analogues of hexadecenoic acid in rats, rabbits and dogs were described for use as possible myocardial imaging agents. The heart-to-blood ratios ranged from 0.13 for 3-telluranonadecenoic acid in rats at 5 mins to 6.25 for 18-methyl-17-tellura-9-nonadecenoic acid in dogs at 24 hrs. The biological half-life of the Te-123m labelled fatty acids ranged from 26 to 583 hrs in the hearts of the test animals. These Te-123m fatty acids were retained in the heart longer than radioiodinated fatty acids and have acceptable absorbed doses to the various target organs. (U.K.)

Evolutionary systems biology of amino acid biosynthetic cost in yeast.

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Michael D Barton

2010-08-01

Full Text Available Every protein has a biosynthetic cost to the cell based on the synthesis of its constituent amino acids. In order to optimise growth and reproduction, natural selection is expected, where possible, to favour the use of proteins whose constituents are cheaper to produce, as reduced biosynthetic cost may confer a fitness advantage to the organism. Quantifying the cost of amino acid biosynthesis presents challenges, since energetic requirements may change across different cellular and environmental conditions. We developed a systems biology approach to estimate the cost of amino acid synthesis based on genome-scale metabolic models and investigated the effects of the cost of amino acid synthesis on Saccharomyces cerevisiae gene expression and protein evolution. First, we used our two new and six previously reported measures of amino acid cost in conjunction with codon usage bias, tRNA gene number and atomic composition to identify which of these factors best predict transcript and protein levels. Second, we compared amino acid cost with rates of amino acid substitution across four species in the genus Saccharomyces. Regardless of which cost measure is used, amino acid biosynthetic cost is weakly associated with transcript and protein levels. In contrast, we find that biosynthetic cost and amino acid substitution rates show a negative correlation, but for only a subset of cost measures. In the economy of the yeast cell, we find that the cost of amino acid synthesis plays a limited role in shaping transcript and protein expression levels compared to that of translational optimisation. Biosynthetic cost does, however, appear to affect rates of amino acid evolution in Saccharomyces, suggesting that expensive amino acids may only be used when they have specific structural or functional roles in protein sequences. However, as there appears to be no single currency to compute the cost of amino acid synthesis across all cellular and environmental

Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy

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Jurkić Lela Munjas

2013-01-01

Full Text Available Abstract Silicon (Si is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4, as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K, the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel, silica gel (amorphous silicon dioxide, and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4 in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation-exchange properties. Numerous biological activities of some types of zeolites documented so far might probably be attributable to the ortho-silicic acid-releasing property. In this review, we therefore discuss biological and potential therapeutic effects of ortho-silicic acid and ortho-silicic acid -releasing silicon compounds as its major natural sources.

Effect of perfluorosulfonic acid membrane equivalent weight on degradation under accelerated stress conditions

International Nuclear Information System (INIS)

Rodgers, Marianne P.; Pearman, Benjamin P.; Mohajeri, Nahid; Bonville, Leonard J.; Slattery, Darlene K.

2013-01-01

The equivalent weight of proton exchange membranes has a large effect on their properties and can impact performance and durability in hydrogen fuel cells. For example, increasing the EW increases the crystallinity of perfluorosulfonic acid membranes, while water content and glass transition temperature decrease. The length of the sulfonic acid side chain also impacts membrane properties. Perfluorosulfonic acid membranes with shorter sulfonic acid side chains, though they exhibit similar gas permeability, have been shown to have higher crystallinity, higher glass transition temperature, slightly lower water content, and lower proton conductivity than membranes with longer sulfonic acid side chains for a given EW. Although many reports have investigated cell performance for membranes as a function of low EW and side chains length, their impact on cell durability is not well understood. Because side chain attack by radicals formed during fuel cell operation is a major source of membrane degradation, it is reasonable to hypothesize that membranes with lower EW and, therefore, more sulfonic acid side chains, would have lower durability. This study evaluates membrane degradation for cells containing PFSA membranes with 750 EW, 950 EW, and 1100 EW. The 750 EW membrane contained short sulfonic acid side-chains while the 950 EW and 1100 EW membranes were Nafion ® -based with long sulfonic acid side-chains. Membranes were tested in fuel cells for 100 h under open circuit voltage, at 90 °C and 30% relative humidity. Diagnostic tests conducted on the cells included hydrogen crossover, fluoride emission, catalyst electrochemical surface area, posttest membrane scanning electron microscopy/transmission electron microscopy evaluation, and defect identification in membranes. The 950 EW cell had the highest decay metrics including fluoride emission, voltage decay, loss in ECA, and loss in cell performance. In all cases, the 1100 EW cell showed the lowest degradation. This has

Proton Transfer in Perfluorosulfonic Acid Fuel Cell Membranes with Differing Pendant Chains and Equivalent Weights.

Science.gov (United States)

Thomaz, Joseph E; Lawler, Christian M; Fayer, Michael D

2017-05-04

Proton transfer in the nanoscopic water channels of polyelectrolyte fuel cell membranes was studied using a photoacid, 8-hydroxypyrene-1,3,6-trisulfonic acid sodium salt (HPTS), in the channels. The local environment of the probe was determined using 8-methoxypyrene-1,3,6-trisulfonic acid sodium salt (MPTS), which is not a photoacid. Three fully hydrated membranes, Nafion (DuPont) and two 3M membranes, were studied to determine the impact of different pendant chains and equivalent weights on proton transfer. Fluorescence anisotropy and excited state population decay data that characterize the local environment of the fluorescent probes and proton transfer dynamics were measured. The MPTS lifetime and anisotropy results show that most of the fluorescent probes have a bulk-like water environment with a relatively small fraction interacting with the channel wall. Measurements of the HPTS protonated and deprotonated fluorescent bands' population decays provided information on the proton transport dynamics. The decay of the protonated band from ∼0.5 ns to tens of nanoseconds is in part determined by dissociation and recombination with the HPTS, providing information on the ability of protons to move in the channels. The dissociation and recombination is manifested as a power law component in the protonated band fluorescence decay. The results show that equivalent weight differences between two 3M membranes resulted in a small difference in proton transfer. However, differences in pendant chain structure did significantly influence the proton transfer ability, with the 3M membranes displaying more facile transfer than Nafion.

Development of radioimmunoassay for pantothenic acid in biological tissues

International Nuclear Information System (INIS)

Wyse, B.W.

1977-01-01

The purpose of this research was to develop a radioimmunoassay for quantitating pantothenic acid levels in biological tissues and to compare the new method with a microbiological procedure. Since pantothenic acid is a nonantigenic compound with a small molecular weight, it was treated as a hapten and conjugated with an immunogenic protein. A new technique for covalently linking haptens with primary alcohol groups to proteins was developed. To prepare an antiserum for the radioimmunoassay, pantothenic acid-bovine serum albumin antigen was injected into the foot pads of rabbits. As antibodies to pantothenic acid hapten were elicited they were characterized using three classical techniques: ring precipitant test, gel diffusion (Ouchterlony), and skin test (Arthus). For the radioimmunoassay an appropriate dilution of antiserum was incubated in the presence of tritium labeled pantothenic acid and non-radioactive pantothenic acid for the standard curve or tissue extracts containing pantothenic acid. After incubation overnight, the antibodies were precipitated and solubilized and the radioactivity was counted in a liquid scintillation counter. Blood pantothenic acid levels of sixty-eight senior citizens were determined by the radioimmunoassay and by microbiological assay with Lactobacillus plantarum. A highly significant correlation was found between the two assays

Maleic acid treatment of biologically detoxified corn stover liquor.

Science.gov (United States)

Kim, Daehwan; Ximenes, Eduardo A; Nichols, Nancy N; Cao, Guangli; Frazer, Sarah E; Ladisch, Michael R

2016-09-01

Elimination of microbial and enzyme inhibitors from pretreated lignocellulose is critical for effective cellulose conversion and yeast fermentation of liquid hot water (LHW) pretreated corn stover. In this study, xylan oligomers were hydrolyzed using either maleic acid or hemicellulases, and other soluble inhibitors were eliminated by biological detoxification. Corn stover at 20% (w/v) solids was LHW pretreated LHW (severity factor: 4.3). The 20% solids (w/v) pretreated corn stover derived liquor was recovered and biologically detoxified using the fungus Coniochaeta ligniaria NRRL30616. After maleic acid treatment, and using 5 filter paper units of cellulase/g glucan (8.3mg protein/g glucan), 73% higher cellulose conversion from corn stover was obtained for biodetoxified samples compared to undetoxified samples. This corresponded to 87% cellulose to glucose conversion. Ethanol production by yeast of pretreated corn stover solids hydrolysate was 1.4 times higher than undetoxified samples, with a reduction of 3h in the fermentation lag phase. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nucleic Acid Templated Reactions for Chemical Biology.

Science.gov (United States)

Di Pisa, Margherita; Seitz, Oliver

2017-06-21

Nucleic acid directed bioorthogonal reactions offer the fascinating opportunity to unveil and redirect a plethora of intracellular mechanisms. Nano- to picomolar amounts of specific RNA molecules serve as templates and catalyze the selective formation of molecules that 1) exert biological effects, or 2) provide measurable signals for RNA detection. Turnover of reactants on the template is a valuable asset when concentrations of RNA templates are low. The idea is to use RNA-templated reactions to fully control the biodistribution of drugs and to push the detection limits of DNA or RNA analytes to extraordinary sensitivities. Herein we review recent and instructive examples of conditional synthesis or release of compounds for in cellulo protein interference and intracellular nucleic acid imaging. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Equivalent Circuit Modeling of the Dielectric Loaded Microwave Biosensor

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M. T. Jilani

2014-12-01

Full Text Available This article describes the modeling of biological tissues at microwave frequency using equivalent lumped elements. A microwave biosensor based on microstrip ring resonator (MRR, that has been utilized previously for meat quality evaluation is used for this purpose. For the first time, the ring-resonator loaded with the lossy and high permittivity dielectric material, such as; biological tissue, in a partial overlay configuration is analyzed. The equivalent circuit modeling of the structure is then performed to identify the effect of overlay thickness on the resonance frequency. Finally, the relationship of an overlay thickness with the corresponding RC values of the meat equivalent circuit is established. Simulated, calculated and measured results are then compared for validation. Results are well agreed while the observed discrepancy is in acceptable limit.

The radiobiology of boron neutron capture therapy: Are ''photon-equivalent'' doses really photon-equivalent?

International Nuclear Information System (INIS)

Coderre, J.A.; Diaz, A.Z.; Ma, R.

2001-01-01

Boron neutron capture therapy (BNCT) produces a mixture of radiation dose components. The high-linear energy transfer (LET) particles are more damaging in tissue than equal doses of low-LET radiation. Each of the high-LET components can multiplied by an experimentally determined factor to adjust for the increased biological effectiveness and the resulting sum expressed in photon-equivalent units (Gy-Eq). BNCT doses in photon-equivalent units are based on a number of assumptions. It may be possible to test the validity of these assumptions and the accuracy of the calculated BNCT doses by 1) comparing the effects of BNCT in other animal or biological models where the effects of photon radiation are known, or 2) if there are endpoints reached in the BNCT dose escalation clinical trials that can be related to the known response to photons of the tissue in question. The calculated Gy-Eq BNCT doses delivered to dogs and to humans with BPA and the epithermal neutron beam of the Brookhaven Medical Research Reactor were compared to expected responses to photon irradiation. The data indicate that Gy-Eq doses in brain may be underestimated. Doses to skin are consistent with the expected response to photons. Gy-Eq doses to tumor are significantly overestimated. A model system of cells in culture irradiated at various depths in a lucite phantom using the epithermal beam is under development. Preliminary data indicate that this approach can be used to detect differences in the relative biological effectiveness of the beam. The rat 9L gliosarcoma cell survival data was converted to photon-equivalent doses using the same factors assumed in the clinical studies. The results superimposed on the survival curve derived from irradiation with Cs-137 photons indicating the potential utility of this model system. (author)

A limited LCA of bio-adipic acid: manufacturing the nylon-6,6 precursor adipic acid using the benzoic acid degradation pathway from different feedstocks.

Science.gov (United States)

van Duuren, J B J H; Brehmer, B; Mars, A E; Eggink, G; Dos Santos, V A P Martins; Sanders, J P M

2011-06-01

A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics, toluene, or phenol from lignin to cis, cis-muconic acid, which is subsequently converted to adipic acid through hydrogenation. Apart from the impact of usage of petrochemical and biomass-based feedstocks, the environmental impact of the final concentration of cis, cis-muconic acid in the fermentation broth was studied using 1.85% and 4.26% cis, cis-muconic acid. The LCA focused on the cumulative energy demand (CED), cumulative exergy demand (CExD), and the CO(2) equivalent (CO(2) eq) emission, with CO(2) and N(2) O measured separately. The highest calculated reduction potential of CED and CExD were achieved using phenol, which reduced the CED by 29% and 57% with 1.85% and 4.26% cis, cis-muconic acid, respectively. A decrease in the CO(2) eq emission was especially achieved when the N(2) O emission in the combined biological and chemical process was restricted. At 4.26% cis, cis-muconic acid, the different carbon backbone feedstocks contributed to an optimized reduction of CO(2) eq emissions ranging from 14.0 to 17.4 ton CO(2) eq/ton adipic acid. The bulk of the bioprocessing energy intensity is attributed to the hydrogenation reactor, which has a high environmental impact and a direct relationship with the product concentration in the broth. Copyright © 2011 Wiley Periodicals, Inc.

Nutritional and medicinal aspects of D-amino acids.

Science.gov (United States)

Friedman, Mendel; Levin, Carol E

2012-05-01

This paper reviews and interprets a method for determining the nutritional value of D-amino acids, D-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential amino acid such as L-lysine (L-Lys), L-methionine (L-Met), L-phenylalanine (L-Phe), and L-tryptophan (L-Trp) as well as the semi-essential amino acids L-cysteine (L-Cys) and L-tyrosine (L-Tyr). The results show wide-ranging variations in the biological utilization of test substances. The method is generally applicable to the determination of the biological utilization and safety of any amino acid derivative as a potential nutritional source of the corresponding L-amino acid. Because the organism is forced to use the D-amino acid or amino acid derivative as the sole source of the essential or semi-essential amino acid being replaced, and because a free amino acid diet allows better control of composition, the use of all-amino-acid diets for such determinations may be preferable to protein-based diets. Also covered are brief summaries of the widely scattered literature on dietary and pharmacological aspects of 27 individual D-amino acids, D-peptides, and isomeric amino acid derivatives and suggested research needs in each of these areas. The described results provide a valuable record and resource for further progress on the multifaceted aspects of D-amino acids in food and biological samples.

Rapid determination of the equivalence volume in potentiometric acid-base titrations to a preset pH-I Theory and applications.

Science.gov (United States)

Ivaska, A

1974-06-01

A new approach to shorten the time needed for an acid-base titration has been made. The method developed is based on the equation for acid-base titrations derived by Ingman and Still. The equation is transformed into such a form that only one titration point is needed to calculate the equivalence volume when the titration is carried out to a preset pH which can be chosen according to the experimental conditions. The method is used for titration of acetic acid, log K(H)(HA) = 4.65, hydroxylammonium ion, log K(H)(HA) approximately 6.2, and boric acid, log K(H)(HA) approximately 9.1, with an error of 0.1-0.5%. In titration of hydrogen ascorbate ion, log K(H)(HA) approximately 11.3, the error obtained was about 0.3-2%.

Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.

Science.gov (United States)

Nguyen, Nguyen Khoi; Dong, Ngan Thi Ngoc; Nguyen, Huong Thuy; Le, Phu Hong

2015-01-01

Kombucha is sweetened black tea that is fermented by a symbiosis of bacteria and yeast embedded within a cellulose membrane. It is considered a health drink in many countries because it is a rich source of vitamins and may have other health benefits. It has previously been reported that adding lactic acid bacteria (Lactobacillus) strains to kombucha can enhance its biological functions, but in that study only lactic acid bacteria isolated from kefir grains were tested. There are many other natural sources of lactic acid bacteria. In this study, we examined the effects of lactic acid bacteria from various fermented Vietnamese food sources (pickled cabbage, kefir and kombucha) on kombucha's three main biological functions: glucuronic acid production, antibacterial activity and antioxidant ability. Glucuronic acid production was determined by high-performance liquid chromatography-mass spectrometry, antibacterial activity was assessed by the agar-well diffusion method and antioxidant ability was evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity. Four strains of food-borne pathogenic bacteria were used in our antibacterial experiments: Listeria monocytogenes ATCC 19111, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028 and Bacillus cereus ATCC 11778. Our findings showed that lactic acid bacteria strains isolated from kefir are superior to those from other sources for improving glucuronic acid production and enhancing the antibacterial and antioxidant activities of kombucha. This study illustrates the potential of Lactobacillus casei and Lactobacillus plantarum isolated from kefir as biosupplements for enhancing the bioactivities of kombucha.

Biological Activities of Toninia candida and Usnea barbata Together with Their Norstictic Acid and Usnic Acid Constituents

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Nedeljko Manojlović

2012-11-01

Full Text Available The aim of this study was to investigate the chemical composition of acetone extracts of the lichens Toninia candida and Usnea barbata and in vitro antioxidant, antimicrobial, and anticancer activities of these extracts together with some of their major metabolites. The chemical composition of T. candida and U. barbata extracts was determined using HPLC-UV analysis. The major phenolic compounds in these extracts were norstictic acid (T. candida and usnic acid (U. barbata. Antioxidant activity was evaluated by free radical scavenging, superoxide anion radical scavenging, reducing power and determination of total phenolic compounds. Results of the study proved that norstictic acid had the largest antioxidant activity. The total content of phenols in the extracts was determined as the pyrocatechol equivalent. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration using the broth microdilution method. The most active was usnic acid with minimum inhibitory concentration values ranging from 0.0008 to 0.5 mg/mL. Anticancer activity was tested against FemX (human melanoma and LS174 (human colon carcinoma cell lines using the microculture tetrazolium test. Usnic acid was found to have the strongest anticancer activity towards both cell lines with IC50 values of 12.72 and 15.66 μg/mL.

Dilute-acid pretreatment of barley straw for biological hydrogen production using Caldicellulosiruptor saccharolyticus

NARCIS (Netherlands)

Panagiotopoulos, I.A.; Bakker, R.R.C.; Vrije, de G.J.; Claassen, P.A.M.; Koukios, E.G.

2012-01-01

The main objective of this study was to use the fermentability test to investigate the feasibility of applying various dilute acids in the pretreatment of barley straw for biological hydrogen production. At a fixed acid loading of 1% (w/w dry matter) 28-32% of barley straw was converted to soluble

Lysophosphatidic acid as a lipid mediator with multiple biological actions.

Science.gov (United States)

Aikawa, Shizu; Hashimoto, Takafumi; Kano, Kuniyuki; Aoki, Junken

2015-02-01

Lysophosphatidic acid (LPA) is one of the simplest glycerophospholipids with one fatty acid chain and a phosphate group as a polar head. Although LPA had been viewed just as a metabolic intermediate in de novo lipid synthetic pathways, it has recently been paid much attention as a lipid mediator. LPA exerts many kinds of cellular processes, such as cell proliferation and smooth muscle contraction, through cognate G protein-coupled receptors. Because lipids are not coded by the genome directly, it is difficult to know their patho- and physiological roles. However, recent studies have identified several key factors mediating the biological roles of LPA, such as receptors and producing enzymes. In addition, studies of transgenic and gene knockout animals for these LPA-related genes, have revealed the biological significance of LPA. In this review we will summarize recent advances in the studies of LPA production and its roles in both physiological and pathological conditions. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Biological properties of nitro-fatty acids in plants.

Science.gov (United States)

Mata-Pérez, Capilla; Padilla, María N; Sánchez-Calvo, Beatriz; Begara-Morales, Juan C; Valderrama, Raquel; Chaki, Mounira; Barroso, Juan B

2018-03-27

Nitro-fatty acids (NO 2 -FAs) are formed from the reaction between nitrogen dioxide (NO 2 ) and mono and polyunsaturated fatty acids. Knowledge concerning NO 2 -FAs has significantly increased within a few years ago and the beneficial actions of these species uncovered in animal systems have led to consider them as molecules with therapeutic potential. Based on their nature and structure, NO 2 -FAs have the ability to release nitric oxide (NO) in aqueous environments and the capacity to mediate post-translational modifications (PTM) by nitroalkylation. Recently, based on the potential of these NO-derived molecules in the animal field, the endogenous occurrence of nitrated-derivatives of linolenic acid (NO 2 -Ln) was assessed in plant species. Moreover and through RNA-seq technology, it was shown that NO 2 -Ln can induce a large set of heat-shock proteins (HSPs) and different antioxidant systems suggesting this molecule may launch antioxidant and defence responses in plants. Furthermore, the capacity of this nitro-fatty acid to release NO has also been demonstrated. In view of this background, here we offer an overview on the biological properties described for NO 2 -FAs in plants and the potential of these molecules to be considered new key intermediaries of NO metabolism in the plant field. Copyright © 2018 Elsevier Inc. All rights reserved.

Non-enzymatic lipid oxidation products in biological systems: assessment of the metabolites from polyunsaturated fatty acids.

Science.gov (United States)

Vigor, Claire; Bertrand-Michel, Justine; Pinot, Edith; Oger, Camille; Vercauteren, Joseph; Le Faouder, Pauline; Galano, Jean-Marie; Lee, Jetty Chung-Yung; Durand, Thierry

2014-08-01

Metabolites of non-enzymatic lipid peroxidation of polyunsaturated fatty acids notably omega-3 and omega-6 fatty acids have become important biomarkers of lipid products. Especially the arachidonic acid-derived F2-isoprostanes are the classic in vivo biomarker for oxidative stress in biological systems. In recent years other isoprostanes from eicosapentaenoic, docosahexaenoic, adrenic and α-linolenic acids have been evaluated, namely F3-isoprostanes, F4-neuroprostanes, F2-dihomo-isoprostanes and F1-phytoprostanes, respectively. These have been gaining interest as complementary specific biomarkers in human diseases. Refined extraction methods, robust analysis and elucidation of chemical structures have improved the sensitivity of detection in biological tissues and fluids. Previously the main reliable instrumentation for measurement was gas chromatography-mass spectrometry (GC-MS), but now the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunological techniques is gaining much attention. In this review, the types of prostanoids generated from non-enzymatic lipid peroxidation of some important omega-3 and omega-6 fatty acids and biological samples that have been determined by GC-MS and LC-MS/MS are discussed. Copyright © 2014. Published by Elsevier B.V.

Comparison of growth, serum biochemistries and n–6 fatty acid metabolism in rats fed diets supplemented with high-gamma-linolenic acid safflower oil or borage oil for 90 days

Science.gov (United States)

Tso, Patrick; Caldwell, Jody; Lee, Dana; Boivin, Gregory P.; DeMichele, Stephen J.

2015-01-01

Recently, steps have been taken to further developments toward increasing gamma-linolenic acid (GLA) concentration and lowering costs in plant seed oils using transgenic technology. Through identification and expression of a fungal delta-6 desaturase gene in the high linoleic acid safflower plant, the seeds from this genetic transformation produce oil with >40% GLA (high GLA safflower oil (HGSO)). The aim of the study was to compare the effects of feeding HGSO to a generally recognized as safe source of GLA, borage oil, in a 90 day safety study in rats. Weanling male and female Sprague–Dawley rats were fed a semi-synthetic, fat free, pelleted diet (AIN93G) supplemented with a 10% (wt/wt) oil blend containing HGSO or borage oil, with equivalent GLA levels. Results demonstrated that feeding diets containing HGSO or borage oil for 90 days had similar biologic effects with regard to growth characteristics, body composition, behavior, organ weight and histology, and parameters of hematology and serum biochemistries in both sexes. Metabolism of the primary n–6 fatty acids in plasma and organ phospholipids was similar, despite minor changes in females. We conclude that HGSO is biologically equivalent to borage oil and provides a safe alternative source of GLA in the diet. PMID:22265940

Comparison of growth, serum biochemistries and n-6 fatty acid metabolism in rats fed diets supplemented with high-gamma-linolenic acid safflower oil or borage oil for 90 days.

Science.gov (United States)

Tso, Patrick; Caldwell, Jody; Lee, Dana; Boivin, Gregory P; DeMichele, Stephen J

2012-06-01

Recently, steps have been taken to further developments toward increasing gamma-linolenic acid (GLA) concentration and lowering costs in plant seed oils using transgenic technology. Through identification and expression of a fungal delta-6 desaturase gene in the high linoleic acid safflower plant, the seeds from this genetic transformation produce oil with >40% GLA (high GLA safflower oil (HGSO)). The aim of the study was to compare the effects of feeding HGSO to a generally recognized as safe source of GLA, borage oil, in a 90 day safety study in rats. Weanling male and female Sprague-Dawley rats were fed a semi-synthetic, fat free, pelleted diet (AIN93G) supplemented with a 10% (wt/wt) oil blend containing HGSO or borage oil, with equivalent GLA levels. Results demonstrated that feeding diets containing HGSO or borage oil for 90 days had similar biologic effects with regard to growth characteristics, body composition, behavior, organ weight and histology, and parameters of hematology and serum biochemistries in both sexes. Metabolism of the primary n-6 fatty acids in plasma and organ phospholipids was similar, despite minor changes in females. We conclude that HGSO is biologically equivalent to borage oil and provides a safe alternative source of GLA in the diet. Copyright © 2012 Elsevier Ltd. All rights reserved.

Biological response to purification and acid functionalization of carbon nanotubes

Science.gov (United States)

Figarol, Agathe; Pourchez, Jérémie; Boudard, Delphine; Forest, Valérie; Tulliani, Jean-Marc; Lecompte, Jean-Pierre; Cottier, Michèle; Bernache-Assollant, Didier; Grosseau, Philippe

2014-07-01

Acid functionalization has been considered as an easy way to enhance the dispersion and biodegradation of carbon nanotubes (CNT). However, inconsistencies between toxicity studies of acid functionalized CNT remain unexplained. This could be due to a joint effect of the main physicochemical modifications resulting from an acid functionalization: addition of surface acid groups and purification from catalytic metallic impurities. In this study, the impact on CNT biotoxicity of these two physiochemical features was assessed separately. The in vitro biological response of RAW 264.7 macrophages was evaluated after exposure to 15-240 µg mL-1 of two types of multi-walled CNT. For each type of CNT (small: 20 nm diameter, and big: 90 nm diameter), three different surface chemical properties were studied (total of six CNT samples): pristine, acid functionalized and desorbed. Desorbed CNT were purified by the acid functionalization but presented a very low amount of surface acid groups due to a thermal treatment under vacuum. A Janus effect of acid functionalization with two opposite impacts is highlighted. The CNT purification decreased the overall toxicity, while the surface acid groups intensified it when present at a specific threshold. These acid groups especially amplified the pro-inflammatory response. The threshold mechanism which seemed to regulate the impact of acid groups should be further studied to determine its value and potential link to the other physicochemical state of the CNT. The results suggest that, for a safer-design approach, the benefit-risk balance of an acid functionalization has to be considered, depending on the CNT primary state of purification. Further research should be conducted in this direction.

Chiral separation of amino acids in biological fluids by micellar electrokinetic chromatography with laser-induced fluorescence detection.

Science.gov (United States)

Thorsén, G; Bergquist, J

2000-08-18

A method is presented for the chiral analysis of amino acids in biological fluids using micellar electrokinetic chromatography (MEKC) and laser-induced fluorescence (LIF). The amino acids are derivatized with the chiral reagent (+/-)-1-(9-anthryl)-2-propyl chloroformate (APOC) and separated using a mixed micellar separation system. No tedious pre-purification of samples is required. The excellent separation efficiency and good detection capabilities of the MEKC-LIF system are exemplified in the analysis of urine and cerebrospinal fluid. This is the first time MEKC has been reported for chiral analysis of amino acids in biological fluids. The amino acids D-alanine, D-glutamine, and D-aspartic acid have been observed in cerebrospinal fluid, and D-alanine and D-glutamic acid in urine. To the best of our knowledge no measurements of either D-alanine in cerebrospinal fluid or D-glutamic acid in urine have been presented in the literature before.

Analysis of biological tissues in infant chest for the development of an equivalent radiographic phantom

International Nuclear Information System (INIS)

Pina, D. R.; Souza, Rafael T. F.; Duarte, Sergio B.; Alvarez, Matheus; Miranda, Jose R. A.

2012-01-01

Purpose: The main purpose of the present study was to determine the amounts of different tissues in the chest of the newborn patient (age ≤1 year), with the aim of developing a homogeneous phantom chest equivalent. This type of phantom is indispensable in the development of optimization procedures for radiographic techniques, including dosimetric control, which is a crucial aspect of pediatric radiology. The authors present a systematic set of procedures, including a computational algorithm, to estimate the amounts of tissues and thicknesses of the corresponding simulator material plates used to construct the phantom. Methods: The Gaussian fit of computed tomographic (CT) analysis was applied to classify and quantify different biological tissues. The methodology is summarized with a computational algorithm, which was used to quantify tissues through automated CT analysis. The thicknesses of the equivalent homogeneous simulator material plates were determined to construct the phantom. Results: A total of 180 retrospective CT examinations with anterior-posterior diameter values ranging 8.5-13.0 cm were examined. The amounts of different tissues were evaluated. The results provided elements to construct a phantom to simulate the infant chest in the posterior-anterior or anterior-posterior (PA/AP) view. Conclusions: To our knowledge, this report represents the first demonstration of an infant chest phantom dedicated to the radiology of children younger than one year. This phantom is a key element in the development of clinical charts for optimizing radiographic technique in pediatric patients. Optimization procedures for nonstandard patients were reported previously [Pina et al., Phys. Med. Biol. 49, N215-N226 (2004) and Pina et al., Appl. Radiat. Isot. 67, 61-69 (2009)]. The constructed phantom represents a starting point to obtain radiologic protocols for the infant patient.

Biological activity of selected plants with adaptogenic effect

Directory of Open Access Journals (Sweden)

Eva Ivanišová

2016-05-01

Full Text Available The aim of this study was to determine biological activity of plants with adaptogenic effect: Panax ginseng Mayer., Withania somnifera L., Eleuterococcus senticosus Rupr. et Maxim., Astragallus membranaceus Fisch. and Codonopsis pilosulae Franch. The antioxidant activity was detected by DPPH and phosphomolybdenum method, total polyphenol content with Folin – Ciocalteu reagent, flavonoids content by aluminium chloride method. The detection of antimicrobial activity was carried out by disc diffusion method against three species of Gram-negative bacteria: Escherichia coli CCM 3988, Salmonella enterica subsp. enterica CCM 3807, Yersinia enterocolitica CCM 5671 and two Gram-positive bacteria: Bacillus thuringiensis CCM 19, Stapylococcus aureus subsp. aureus CCM 2461. Results showed that plants with adaptogenic effect are rich for biologically active substances. The highest antioxidant activity by DPPH method was determined in the sample of Eleuterococcus senticosus (3.15 mg TEAC – Trolox equivalent antioxidant capacity per g of sample and by phosphomolybdenum method in the sample of Codonopsis pilosulae (188.79 mg TEAC per g of sample. In the sample of Panax ginseng was measured the highest content of total polyphenols (8.10 mg GAE – galic acid equivalent per g of sample and flavonoids (3.41 μg QE – quercetin equivalent per g of sample. All samples also showed strong antimicrobial activity with the best results in Panax ginseng and Withania somnifera in particular for species Yersinia enterocolitica CCM 5671 and Salmonella enterica subsp. enterica CCM 3807. The analyzed species of plant with high value of biological activity can be used more in the future, not only in food, but also in cosmetics and pharmaceutical industries.

Use of hexadeuterated valproic acid and gas chromatography-mass spectrometry to determine the pharmacokinetics of valproic acid

International Nuclear Information System (INIS)

Acheampong, A.A.; Abbott, F.S.; Orr, J.M.; Ferguson, S.M.; Burton, R.W.

1984-01-01

Di-[( 3,3,3- 2 H3]propyl)acetic acid, a hexadeuterated analogue of valproic acid, was synthesized and its pharmacokinetic properties compared with valproic acid. Concentrations of valproic acid and [ 2 H]valproic acid in serum and saliva were determined by GC-MS using selected-ion monitoring. Saliva drug levels were measured with good precision down to 0.1 microgram/mL. Kinetic equivalence of valproic acid and [ 2 H]valproic acid was demonstrated in a single-dose study in a human volunteer. An isotope effect was observed for omega-oxidation, but the difference in metabolism was not sufficient to make [ 2 H]valproic acid biologically nonequivalent. The application of [ 2 H]valproic acid to determine the kinetics of valproic acid under steady-state concentrations was evaluated in the same volunteer. The kinetic data obtained with [ 2 H]valproic acid was consistent with previously reported values for valproic acid including kinetic differences observed between single-dose and steady-state experiments. Saliva levels of valproic acid were found to give a good correlation with total serum valproic acid under multiple-dose conditions. A concentration dependence was found for the ratio of saliva valproic acid to free valproic acid in serum, low ratios being observed at high serum concentrations of valproic acid

A LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) for biological tissue impedance analysis and equivalent circuit modelling

KAUST Repository

Bera, Tushar Kanti

2016-12-05

Under an alternating electrical signal, biological tissues produce a complex electrical bioimpedance that is a function of tissue composition and applied signal frequencies. By studying the bioimpedance spectra of biological tissues over a wide range of frequencies, we can noninvasively probe the physiological properties of these tissues to detect possible pathological conditions. Electrical impedance spectroscopy (EIS) can provide the spectra that are needed to calculate impedance parameters within a wide range of frequencies. Before impedance parameters can be calculated and tissue information extracted, impedance spectra should be processed and analyzed by a dedicated software program. National Instruments (NI) Inc. offers LabVIEW, a fast, portable, robust, user-friendly platform for designing dataanalyzing software. We developed a LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) to analyze the electrical impedance spectra for tissue characterization in medical, biomedical and biological applications. Here, we test, calibrate and evaluate the performance of LEBISDI on the impedance data obtained from simulation studies as well as the practical EIS experimentations conducted on electronic circuit element combinations and the biological tissue samples. We analyze the Nyquist plots obtained from the EIS measurements and compare the equivalent circuit parameters calculated by LEBISDI with the corresponding original circuit parameters to assess the accuracy of the program developed. Calibration studies show that LEBISDI not only interpreted the simulated and circuitelement data accurately, but also successfully interpreted tissues impedance data and estimated the capacitive and resistive components produced by the compositions biological cells. Finally, LEBISDI efficiently calculated and analyzed variation in bioimpedance parameters of different tissue compositions, health and temperatures. LEBISDI can also be used for human tissue

A LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) for biological tissue impedance analysis and equivalent circuit modelling

KAUST Repository

Bera, Tushar Kanti; Jampana, Nagaraju; Lubineau, Gilles

2016-01-01

Under an alternating electrical signal, biological tissues produce a complex electrical bioimpedance that is a function of tissue composition and applied signal frequencies. By studying the bioimpedance spectra of biological tissues over a wide range of frequencies, we can noninvasively probe the physiological properties of these tissues to detect possible pathological conditions. Electrical impedance spectroscopy (EIS) can provide the spectra that are needed to calculate impedance parameters within a wide range of frequencies. Before impedance parameters can be calculated and tissue information extracted, impedance spectra should be processed and analyzed by a dedicated software program. National Instruments (NI) Inc. offers LabVIEW, a fast, portable, robust, user-friendly platform for designing dataanalyzing software. We developed a LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) to analyze the electrical impedance spectra for tissue characterization in medical, biomedical and biological applications. Here, we test, calibrate and evaluate the performance of LEBISDI on the impedance data obtained from simulation studies as well as the practical EIS experimentations conducted on electronic circuit element combinations and the biological tissue samples. We analyze the Nyquist plots obtained from the EIS measurements and compare the equivalent circuit parameters calculated by LEBISDI with the corresponding original circuit parameters to assess the accuracy of the program developed. Calibration studies show that LEBISDI not only interpreted the simulated and circuitelement data accurately, but also successfully interpreted tissues impedance data and estimated the capacitive and resistive components produced by the compositions biological cells. Finally, LEBISDI efficiently calculated and analyzed variation in bioimpedance parameters of different tissue compositions, health and temperatures. LEBISDI can also be used for human tissue

Modified methods for growing 3-D skin equivalents: an update.

Science.gov (United States)

Lamb, Rebecca; Ambler, Carrie A

2014-01-01

Artificial epidermis can be reconstituted in vitro by seeding primary epidermal cells (keratinocytes) onto a supportive substrate and then growing the developing skin equivalent at the air-liquid interface. In vitro skin models are widely used to study skin biology and for industrial drug and cosmetic testing. Here, we describe updated methods for growing 3-dimensional skin equivalents using de-vitalized, de-epidermalized dermis (DED) substrates including methods for DED substrate preparation, cell seeding, growth conditions, and fixation procedures.

Biological Activities of Uric Acid in Infection Due to Enteropathogenic and Shiga-Toxigenic Escherichia coli

Science.gov (United States)

Broome, Jacqueline E.; Lis, Agnieszka

2016-01-01

In previous work, we identified xanthine oxidase (XO) as an important enzyme in the interaction between the host and enteropathogenic Escherichia coli (EPEC) and Shiga-toxigenic E. coli (STEC). Many of the biological effects of XO were due to the hydrogen peroxide produced by the enzyme. We wondered, however, if uric acid generated by XO also had biological effects in the gastrointestinal tract. Uric acid triggered inflammatory responses in the gut, including increased submucosal edema and release of extracellular DNA from host cells. While uric acid alone was unable to trigger a chloride secretory response in intestinal monolayers, it did potentiate the secretory response to cyclic AMP agonists. Uric acid crystals were formed in vivo in the lumen of the gut in response to EPEC and STEC infections. While trying to visualize uric acid crystals formed during EPEC and STEC infections, we noticed that uric acid crystals became enmeshed in the neutrophilic extracellular traps (NETs) produced from host cells in response to bacteria in cultured cell systems and in the intestine in vivo. Uric acid levels in the gut lumen increased in response to exogenous DNA, and these increases were enhanced by the actions of DNase I. Interestingly, addition of DNase I reduced the numbers of EPEC bacteria recovered after a 20-h infection and protected against EPEC-induced histologic damage. PMID:26787720

Neutron dosimetry using proportional counters with tissue equivalent walls

International Nuclear Information System (INIS)

Kerviller, H. de

1965-01-01

The author reminds the calculation method of the neutron absorbed dose in a material and deduce of it the conditions what this material have to fill to be equivalent to biological tissues. Various proportional counters are mode with walls in new tissue equivalent material and filled with various gases. The multiplication factor and neutron energy response of these counters are investigated and compared with those obtained with ethylene lined polyethylene counters. The conditions of working of such proportional counters for neutron dosimetry in energy range 10 -2 to 15 MeV are specified. (author) [fr

Principles of Chemical Biology: From Sexy Fatty Acids and EBV probes to Anti-Acid Antibiotic via Post-Biotics and Host-Microbe Metabolic Complementarity.

Science.gov (United States)

2017-06-22

This month: The role of fatty acids in sex determination; a probe to monitor and inhibit EBNA1 at the same time; a biological role for post-biotics; what happens when you mix microbes, hosts, and drugs; and an antibiotic that cross-protects with acid. Copyright © 2017. Published by Elsevier Ltd.

Experimental method research on neutron equal dose-equivalent detection

International Nuclear Information System (INIS)

Ji Changsong

1995-10-01

The design principles of neutron dose-equivalent meter for neutron biological equi-effect detection are studied. Two traditional principles 'absorption net principle' and 'multi-detector principle' are discussed, and on the basis of which a new theoretical principle for neutron biological equi-effect detection--'absorption stick principle' has been put forward to place high hope on both increasing neutron sensitivity of this type of meters and overcoming the shortages of the two traditional methods. In accordance with this new principle a brand-new model of neutron dose-equivalent meter BH3105 has been developed. Its neutron sensitivity reaches 10 cps/(μSv·h -1 ), 18∼40 times higher than that of all the same kinds of meters 0.23∼0.56 cps/(μSv·h -1 ), available today at home and abroad and the specifications of the newly developed meter reach or surpass the levels of the same kind of meters. Therefore the new theoretical principle of neutron biological equi-effect detection--'absorption stick principle' is proved to be scientific, advanced and useful by experiments. (3 refs., 3 figs., 2 tabs.)

Dose distribution around ion track in tissue equivalent material

International Nuclear Information System (INIS)

Zhang Wenzhong; Guo Yong; Luo Yisheng

2007-01-01

Objective: To study the energy deposition micro-specialty of ions in body-tissue or tissue equivalent material (TEM). Methods: The water vapor was determined as the tissue equivalent material, based on the analysis to the body-tissue, and Monte Carlo method was used to simulate the behavior of proton in the tissue equivalent material. Some features of the energy deposition micro-specialty of ion in tissue equivalent material were obtained through the analysis to the data from calculation. Results: The ion will give the energy by the way of excitation and ionization in material, then the secondary electrons will be generated in the progress of ionization, these electron will finished ions energy deposition progress. When ions deposited their energy, large amount energy will be in the core of tracks, and secondary electrons will devote its' energy around ion track, the ion dose distribution is then formed in TEM. Conclusions: To know biological effects of radiation , the research to dose distribution of ions is of importance(significance). (authors)

Seven fundamental, unsolved questions in molecular biology. Cooperative storage and bi-directional transfer of biological information by nucleic acids and proteins: an alternative to "central dogma".

Science.gov (United States)

Biro, J C

2004-01-01

The Human Genome Mapping Project provided us a large amount of sequence data. However our understanding of these data did not grow proportionally, because old dogmas still set the limits of our thinking. The gene-centric, reductionistical side of molecular biology is reviewed and seven problems are formulated, each indicating the insufficiency of the "central dogma". The following is concluded and suggested: 1. Genes are located and expressed on both DNA strands; 2. Introns are the source of important biological regulation and diversity; 3. Repeats are the frame of the chromatin structure and participate in the chromatin regulation; 4. The molecular accessibility of the canonical dsDNA structure is poor; 5. The genetic code is co-evolved with the amino acids and there is a stereochemical matching between the codes andamino acids; 6. The flow of information between nucleic acids and proteins is bi-directional and reverse translation might exist; 7. Complex genetic information is always carried and stored by nucleic acids and proteins together.

Chemical Properties of Caffeic and Ferulic Acids in Biological System: Implications in Cancer Therapy. A Review.

Science.gov (United States)

Damasceno, Sarah S; Dantas, Bruna B; Ribeiro-Filho, Jaime; Antônio M Araújo, Demetrius; Galberto M da Costa, José

2017-01-01

The antioxidant properties of caffeic and ferulic acids in biological systems have been extensively demonstrated. As antioxidants, these compounds prevent the production of reactive oxygen species (ROS), which cause cell lesions that are associated with the development of several diseases, including cancer. Recent findings suggest that the chemoprotective action of these phenolic acids occurs through the following mechanisms: regulation of gene expression, chelation and / or reduction of transition metals, formation of covalent adducts and direct toxicity. The biological efficacy of these promising chemoprotective agents is strongly related with their chemical structure. Therefore, in this study, we discuss the structural characteristics of ferulic and caffeic acids that are responsible for their biological activities, as well as the mechanisms of action involved with the anti-cancer activity. Several reports indicated that the antioxidant effect of these phenylpropanoids results from reactions with free radicals with formation of stable products in the cells. The chelating effect of these compounds was also reported as an important protective mechanism against oxidative. Finally, the lipophilicity of these agents facilitates their entry into the cells, and thus, contributes to the anticancer activity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Key discoveries in bile acid chemistry and biology and their clinical applications: history of the last eight decades.

Science.gov (United States)

Hofmann, Alan F; Hagey, Lee R

2014-08-01

During the last 80 years there have been extraordinary advances in our knowledge of the chemistry and biology of bile acids. We present here a brief history of the major achievements as we perceive them. Bernal, a physicist, determined the X-ray structure of cholesterol crystals, and his data together with the vast chemical studies of Wieland and Windaus enabled the correct structure of the steroid nucleus to be deduced. Today, C24 and C27 bile acids together with C27 bile alcohols constitute most of the bile acid "family". Patterns of bile acid hydroxylation and conjugation are summarized. Bile acid measurement encompasses the techniques of GC, HPLC, and MS, as well as enzymatic, bioluminescent, and competitive binding methods. The enterohepatic circulation of bile acids results from vectorial transport of bile acids by the ileal enterocyte and hepatocyte; the key transporters have been cloned. Bile acids are amphipathic, self-associate in solution, and form mixed micelles with polar lipids, phosphatidylcholine in bile, and fatty acids in intestinal content during triglyceride digestion. The rise and decline of dissolution of cholesterol gallstones by the ingestion of 3,7-dihydroxy bile acids is chronicled. Scientists from throughout the world have contributed to these achievements. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

Politico-economic equivalence

DEFF Research Database (Denmark)

Gonzalez Eiras, Martin; Niepelt, Dirk

2015-01-01

Traditional "economic equivalence'' results, like the Ricardian equivalence proposition, define equivalence classes over exogenous policies. We derive "politico-economic equivalence" conditions that apply in environments where policy is endogenous and chosen sequentially. A policy regime and a st......Traditional "economic equivalence'' results, like the Ricardian equivalence proposition, define equivalence classes over exogenous policies. We derive "politico-economic equivalence" conditions that apply in environments where policy is endogenous and chosen sequentially. A policy regime...... their use in the context of several applications, relating to social security reform, tax-smoothing policies and measures to correct externalities....

Synthesis, physicochemical properties, and biological activity of bile acids 3-glucuronides: Novel insights into bile acid signalling and detoxification.

Science.gov (United States)

Mostarda, Serena; Passeri, Daniela; Carotti, Andrea; Cerra, Bruno; Colliva, Carolina; Benicchi, Tiziana; Macchiarulo, Antonio; Pellicciari, Roberto; Gioiello, Antimo

2018-01-20

Glucuronidation is considered an important detoxification pathway of bile acids especially in cholestatic conditions. Glucuronides are less toxic than the parent free forms and are more easily excreted in urine. However, the pathophysiological significance of bile acid glucuronidation is still controversial and debated among the scientific community. Progress in this field has been strongly limited by the lack of appropriate methods for the preparation of pure glucuronides in the amount needed for biological and pharmacological studies. In this work, we have developed a new synthesis of bile acid C3-glucuronides enabling the convenient preparation of gram-scale quantities. The synthesized compounds have been characterized in terms of physicochemical properties and abilities to modulate key nuclear receptors including the farnesoid X receptor (FXR). In particular, we found that C3-glucuronides of chenodeoxycholic acid and lithocholic acid, respectively the most abundant and potentially cytotoxic species formed in patients affected by cholestasis, behave as FXR agonists and positively regulate the gene expression of transporter proteins, the function of which is critical in human conditions related to imbalances of bile acid homeostasis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

What is correct: equivalent dose or dose equivalent

International Nuclear Information System (INIS)

Franic, Z.

1994-01-01

In Croatian language some physical quantities in radiation protection dosimetry have not precise names. Consequently, in practice either terms in English or mathematical formulas are used. The situation is even worse since the Croatian language only a limited number of textbooks, reference books and other papers are available. This paper compares the concept of ''dose equivalent'' as outlined in International Commission on Radiological Protection (ICRP) recommendations No. 26 and newest, conceptually different concept of ''equivalent dose'' which is introduced in ICRP 60. It was found out that Croatian terminology is both not uniform and unprecise. For the term ''dose equivalent'' was, under influence of Russian and Serbian languages, often used as term ''equivalent dose'' even from the point of view of ICRP 26 recommendations, which was not justified. Unfortunately, even now, in Croatia the legal unit still ''dose equivalent'' defined as in ICRP 26, but the term used for it is ''equivalent dose''. Therefore, in Croatian legislation a modified set of quantities introduced in ICRP 60, should be incorporated as soon as possible

Physical models of biological information and adaptation.

Science.gov (United States)

Stuart, C I

1985-04-07

The bio-informational equivalence asserts that biological processes reduce to processes of information transfer. In this paper, that equivalence is treated as a metaphor with deeply anthropomorphic content of a sort that resists constitutive-analytical definition, including formulation within mathematical theories of information. It is argued that continuance of the metaphor, as a quasi-theoretical perspective in biology, must entail a methodological dislocation between biological and physical science. It is proposed that a general class of functions, drawn from classical physics, can serve to eliminate the anthropomorphism. Further considerations indicate that the concept of biological adaptation is central to the general applicability of the informational idea in biology; a non-anthropomorphic treatment of adaptive phenomena is suggested in terms of variational principles.

Genetic effects of formaldehyde in yeast. Current status and limitations of the radiation equivalence concept

International Nuclear Information System (INIS)

Chanet, R.; Magana-Schwencke, N.; Moustacchi, E.

1980-01-01

Values of radiation equivalents of chemicals have been calculated for formaldehyde (FA) from detailed data on its genetic effects on yeast, Saccharomyces cerevisiae, and compared with the effects induced by gamma radiation. For the haploid yeast strain, 1 (mmol FA.ltr -1 ).min (i.e. 1 mM FA.min) is equivalent to 9.6 rad, and for diploid yeast it is equivalent to 33 rad. These values are within the range of values calculated for E. coli and mammalian cells. Some major differences in the response to FA and radiation are encountered, depending upon the cellular physiological conditions, the genetic background and the degree of ploidy (haploid versus diploid) and growth phase (exponential versus stationary), among others. Difficulties encountered in the estimation of rad-equivalent values for specific chemicals and for defined biological end-points (e.g. rate of reverse mutation in the specific biochemical loci) are discussed. It is concluded that by exercising appropriate caution relating to the differences in the mechanisms of action of the chemical mutagens and radiations, meaningful rad-equivalent values could be estimated that could help express the comparative biological effects of chemicals in terms of radiation unit. (author)

Colloquium paper: uniquely human evolution of sialic acid genetics and biology.

Science.gov (United States)

Varki, Ajit

2010-05-11

Darwinian evolution of humans from our common ancestors with nonhuman primates involved many gene-environment interactions at the population level, and the resulting human-specific genetic changes must contribute to the "Human Condition." Recent data indicate that the biology of sialic acids (which directly involves less than 60 genes) shows more than 10 uniquely human genetic changes in comparison with our closest evolutionary relatives. Known outcomes are tissue-specific changes in abundant cell-surface glycans, changes in specificity and/or expression of multiple proteins that recognize these glycans, and novel pathogen regimes. Specific events include Alu-mediated inactivation of the CMAH gene, resulting in loss of synthesis of the Sia N-glycolylneuraminic acid (Neu5Gc) and increase in expression of the precursor N-acetylneuraminic acid (Neu5Ac); increased expression of alpha2-6-linked Sias (likely because of changed expression of ST6GALI); and multiple changes in SIGLEC genes encoding Sia-recognizing Ig-like lectins (Siglecs). The last includes binding specificity changes (in Siglecs -5, -7, -9, -11, and -12); expression pattern changes (in Siglecs -1, -5, -6, and -11); gene conversion (SIGLEC11); and deletion or pseudogenization (SIGLEC13, SIGLEC14, and SIGLEC16). A nongenetic outcome of the CMAH mutation is human metabolic incorporation of foreign dietary Neu5Gc, in the face of circulating anti-Neu5Gc antibodies, generating a novel "xeno-auto-antigen" situation. Taken together, these data suggest that both the genes associated with Sia biology and the related impacts of the environment comprise a relative "hot spot" of genetic and physiological changes in human evolution, with implications for uniquely human features both in health and disease.

Conjugated linolenic acids (CLnA, super CLA – natural sources and biological activity

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Agnieszka Białek

2014-11-01

Full Text Available Polyunsaturated fatty acids (PUFA have a wide range of biological activity. Among them conjugated fatty acids are of great interest. Conjugated linoleic acids (CLA, which exert a multidirectional health-benefiting influence, and conjugated linolenic acids (CLnA, super CLA are examples of this group of fatty acids. CLnA are a group of positional and geometric isomers of octadecatrienoic acid (C18:3, which possess double bonds at positions 9, 11, 13 or 8, 10, 12 of their chain. Some vegetable oils are rich sources of CLnA, e.g. bitter melon oil (from Momordica charantia seeds and pomegranate oil (from Punica granatum seeds. The aim of this paper was to present information concerning natural sources and health-promoting activities of conjugated linolenic acids.The presented data reveal that conjugated linolenic acids may be very useful in prevention and treatment of many diseases, especially diabetes, arteriosclerosis , obesity and cancers (mammary, prostate and colon cancer. Among many potential mechanisms of their action, the fact that some CLnA are converted by oxidoreductases into CLA is very important. It seems to be very reasonable to conduct research concerning the possibility of CLnA use in prevention of many diseases.

Single amino acid substitution in important hemoglobinopathies does not disturb molecular function and biological process

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Viroj Wiwanitkit

2008-06-01

Full Text Available Viroj WiwanitkitDepartment of Laboratory Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, ThailandAbstract: Hemoglobin is an important protein found in the red cells of many animals. In humans, the hemoglobin is mainly distributed in the red blood cell. Single amino acid substitution is the main pathogenesis of most hemoglobin disorders. Here, the author used a new gene ontology technology to predict the molecular function and biological process of four important hemoglobin disorders with single substitution. The four studied important abnormal hemoglobins (Hb with single substitution included Hb S, Hb E, Hb C, and Hb J-Baltimore. Using the GoFigure server, the molecular function and biological process in normal and abnormal hemoglobins was predicted. Compared with normal hemoglobin, all studied abnormal hemoglobins had the same function and biological process. This indicated that the overall function of oxygen transportation is not disturbed in the studied hemoglobin disorders. Clinical findings of oxygen depletion in abnormal hemoglobin should therefore be due to the other processes rather than genomics, proteomics, and expression levels.Keywords: hemoglobin, amino acid, substitution, function

Extremely acidic mine lake ecosystems in Lusatia (Germany) : characterisation and development of sustainable, biology-based acidity removal technologies

International Nuclear Information System (INIS)

Fyson, A.; Deneke, R.; Nixdorf, B.; Steinberg, C.E.W.

2003-01-01

There are approximately 500 infilled open-cast lignite pits in Germany that are extremely acidic because of high concentrations of dissolved metals, mostly iron and aluminium. The mining lakes have pH values of 2.4 to 3.4 and also have high sulphate concentrations. Efforts are being made to neutralize the lakes for recreational purposes. The acidity can be removed from the lakes in an economical and environmentally sustainable manner by flooding through diversion of neutral, nutrient-rich river water. This paper described the living conditions of the acidic mining lakes in the Lausitz region of Germany and summarized the benefits of the controlled eutrophication approach to enhance natural, self-sustaining processes for acid neutralization. Compared to infilling with river water, eutrophication increases lake productivity and removes acidity through sediment bound and water column biologically-mediated processes. The study involved basic research on particle transport in streams and lakes, pelagic food web interactions and submerged macrophyte metabolism. It also looked at the role of wetlands, bacterial interactions at the water-sediment interface, and modelling. It was shown that the addition of phosphorus and carbon to the water column can enhance primary production. Future studies will examine environmentally acceptable treatment strategies that offer an alternative to chemical treatment. 20 refs., 1 tab., 2 figs

Water-equivalence of gel dosimeters for radiology medical imaging

Energy Technology Data Exchange (ETDEWEB)

Valente, M; Vedelago, J.; Perez, P. [Instituto de Fisica Enrique Gaviola - CONICET, Av. Medina Allende s/n, Ciudad Universitaria, X5000HUA, Cordoba (Argentina); Chacon, D.; Mattea, F. [Universidad Nacional de Cordoba, FAMAF, Laboratorio de Investigacion e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Av. Medina Allende s/n, Ciudad Universitaria, X5000HUA Cordoba (Argentina); Velasquez, J., E-mail: valente@famaf.unc.edu.ar [ICOS Inmunomedica, Lago Puyehue 01745, Temuco (Chile)

2017-10-15

International dosimetry protocols are based on determinations of absorbed dose to water. Ideally, the phantom material should be water equivalent; that is, it should have the same absorption and scatter properties as water. This study presents theoretical, experimental and Monte Carlo modeling of water-equivalence of Fricke and polymer (NIPAM, PAGAT and itaconic acid ITABIS) gel dosimeters. Mass and electronic densities along with effective atomic number were calculated by means of theoretical approaches. Samples were scanned by standard computed tomography and high-resolution micro computed tomography. Photon mass attenuation coefficients and electron stopping powers were examined by Monte Carlo simulations. Theoretical, Monte Carlo and experimental results confirmed good water-equivalence for all gel dosimeters. Overall variations with respect to water in the low energy radiology range (up to 130 k Vp) were found to be less than 3% in average. (Author)

Water-equivalence of gel dosimeters for radiology medical imaging

International Nuclear Information System (INIS)

Valente, M; Vedelago, J.; Perez, P.; Chacon, D.; Mattea, F.; Velasquez, J.

2017-10-01

International dosimetry protocols are based on determinations of absorbed dose to water. Ideally, the phantom material should be water equivalent; that is, it should have the same absorption and scatter properties as water. This study presents theoretical, experimental and Monte Carlo modeling of water-equivalence of Fricke and polymer (NIPAM, PAGAT and itaconic acid ITABIS) gel dosimeters. Mass and electronic densities along with effective atomic number were calculated by means of theoretical approaches. Samples were scanned by standard computed tomography and high-resolution micro computed tomography. Photon mass attenuation coefficients and electron stopping powers were examined by Monte Carlo simulations. Theoretical, Monte Carlo and experimental results confirmed good water-equivalence for all gel dosimeters. Overall variations with respect to water in the low energy radiology range (up to 130 k Vp) were found to be less than 3% in average. (Author)

Modeling and simulation of equivalent circuits in description of biological systems - a fractional calculus approach

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José Francisco Gómez Aguilar

2012-07-01

Full Text Available Using the fractional calculus approach, we present the Laplace analysis of an equivalent electrical circuit for a multilayered system, which includes distributed elements of the Cole model type. The Bode graphs are obtained from the numerical simulation of the corresponding transfer functions using arbitrary electrical parameters in order to illustrate the methodology. A numerical Laplace transform is used with respect to the simulation of the fractional differential equations. From the results shown in the analysis, we obtain the formula for the equivalent electrical circuit of a simple spectrum, such as that generated by a real sample of blood tissue, and the corresponding Nyquist diagrams. In addition to maintaining consistency in adjusted electrical parameters, the advantage of using fractional differential equations in the study of the impedance spectra is made clear in the analysis used to determine a compact formula for the equivalent electrical circuit, which includes the Cole model and a simple RC model as special cases.

Equivalent Lagrangians

International Nuclear Information System (INIS)

Hojman, S.

1982-01-01

We present a review of the inverse problem of the Calculus of Variations, emphasizing the ambiguities which appear due to the existence of equivalent Lagrangians for a given classical system. In particular, we analyze the properties of equivalent Lagrangians in the multidimensional case, we study the conditions for the existence of a variational principle for (second as well as first order) equations of motion and their solutions, we consider the inverse problem of the Calculus of Variations for singular systems, we state the ambiguities which emerge in the relationship between symmetries and conserved quantities in the case of equivalent Lagrangians, we discuss the problems which appear in trying to quantize classical systems which have different equivalent Lagrangians, we describe the situation which arises in the study of equivalent Lagrangians in field theory and finally, we present some unsolved problems and discussion topics related to the content of this article. (author)

Evaluation of treatment effects for high-performance dye-sensitized solar cells using equivalent circuit analysis

International Nuclear Information System (INIS)

Murayama, Masaki; Mori, Tatsuo

2006-01-01

Equivalent circuit analysis using a one-diode model was carried out as a simpler, more convenient method to evaluate the electric mechanism and to employ effective treatment of a dye-sensitized solar cell (DSC). Cells treated using acetic acid or 4,t-butylpyridine were measured under irradiation (0.1 W/m 2 , AM 1.5) to obtain current-voltage (I-V) curves. Cell performance and equivalent circuit parameters were calculated from the I-V curves. Evaluation based on residual factors was useful for better fitting of the equivalent circuit to the I-V curve. The diode factor value was often over two for high-performance DSCs. Acetic acid treatment was effective to increase the short-circuit current by decreasing the series resistance of cells. In contrast, 4,t-butylpyridine was effective to increase open-circuit voltage by increasing the cell shunt resistance. Previous explanations considered that acetic acid worked to decrease the internal resistance of the TiO 2 layer and butylpyridine worked to lower the back-electron-transfer from the TiO 2 to the electrolyte

Polyunsaturated fatty acid amides from the Zanthoxylum genus - from culinary curiosities to probes for chemical biology.

Science.gov (United States)

Chruma, Jason J; Cullen, Douglas J; Bowman, Lydia; Toy, Patrick H

2018-01-25

Covering up to February 2017The pericarps of several species from the Zanthoxylum genus, a.k.a. the "prickly ash", have long been used for culinary purposes throughout Asia, most notably in the Sichuan (previously Szechuan) cuisine of Southwestern China, due to the unique tingling and numbing orosensations arising from a collection of polyunsaturated fatty acid amide (alkamide) constituents. The past decade has experienced dramatically increased academic and industrial interest in these pungent Zanthoxylum-derived alkamides, with a concomitant explosion in studies aimed at elucidating the specific biochemical mechanisms behind several medically-relevant biological activities exhibited by the natural products. This rapid increase in interest is partially fueled by advances in organic synthesis reported within the past few years that finally have allowed for the production of diastereomerically-pure Zanthoxylum alkamides and related analogs in multigram quantities. Herein is a comprehensive review of the discovery, total synthesis, and biological evaluation of Zanthoxylum-derived polyunsaturated fatty acid amides and synthetic analogues. Critical insights into how chemical synthesis can further benefit future chemical biology efforts in the field are also provided.

Benefits of the effective dose equivalent concept at a medical center

International Nuclear Information System (INIS)

Vetter, R.J.; Classic, K.L.

1991-01-01

A primary objective of the recommendations of the International Committee on Radiological Protection Publication 26 is to insure that no source of radiation exposure is unjustified in relation to its benefits. This objective is consistent with goals of the Radiation Safety Committee and Institutional Review Board at medical centers where research may involve radiation exposure of human subjects. The effective dose equivalent concept facilitates evaluation of risk by those who have little or no knowledge of quantities or biological effects of radiation. This paper presents effective dose equivalent data used by radiation workers and those who evaluate human research protocols as these data relate to personal dosimeter reading, entrance skin exposure, and target organ dose. The benefits of using effective dose equivalent to evaluate risk of medical radiation environments and research protocols are also described

Biology and chemistry of three Pennsylvania lakes: responses to acid precipitation

Energy Technology Data Exchange (ETDEWEB)

Bradt, P.T.; Dudley, J.L.; Berg, M.B.; Barrasso, D.S.

1986-09-01

The biology and chemistry of three northeastern Pennsylvania lakes was studied from summer 1981 through summer 1983 to evaluate lakes with different sensitivities to acidification. At the acidified lake there were fewer phytoplankton and zooplankton species than at the moderately sensitive lakes. The most numerous plankton species in all three lakes are reportedly acid tolerant. Among the benthic macro-invertebrates (BMI) there were more acid tolerant Chironomidae at the acidified lake, but more acid intolerant Ephemeroptera and Mollusca and a higher wet weight at the least sensitive lake. There were no differences among the lakes' BMI mean total numbers or mean number of taxa. The fish community at the acidified lake was dominated by stunted Lepomis gibbosus, but L. machrochirous were most abundant in the other lakes. Principal component analysis suggested a shift in all three lakes over the sampling period toward combined lower pH, alkalinity, specific conductance, Ca and Mg and higher Al and Mn. Such chemical changes have been associated with acidification. The rate and extent of acidification appeared to be controlled by geological and hydrological characteristics of the drainage basins. 38 refs.

Equivalent formulations of “the equation of life”

International Nuclear Information System (INIS)

Ao Ping

2014-01-01

Motivated by progress in theoretical biology a recent proposal on a general and quantitative dynamical framework for nonequilibrium processes and dynamics of complex systems is briefly reviewed. It is nothing but the evolutionary process discovered by Charles Darwin and Alfred Wallace. Such general and structured dynamics may be tentatively named “the equation of life”. Three equivalent formulations are discussed, and it is also pointed out that such a quantitative dynamical framework leads naturally to the powerful Boltzmann-Gibbs distribution and the second law in physics. In this way, the equation of life provides a logically consistent foundation for thermodynamics. This view clarifies a particular outstanding problem and further suggests a unifying principle for physics and biology. (topical review - statistical physics and complex systems)

Biological Production of 3-Hydroxypropionic Acid: An Update on the Current Status

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Leonidas Matsakas

2018-02-01

Full Text Available The production of high added-value chemicals from renewable resources is a necessity in our attempts to switch to a more sustainable society. 3-Hydroxypropionic acid (3HP is a promising molecule that can be used for the production of an important array of high added-value chemicals, such as 1,3-propanediol, acrylic acid, acrylamide, and bioplastics. Biological production of 3HP has been studied extensively, mainly from glycerol and glucose, which are both renewable resources. To enable conversion of these carbon sources to 3HP, extensive work has been performed to identify appropriate biochemical pathways and the enzymes that are involved in them. Novel enzymes have also been identified and expressed in host microorganisms to improve the production yields of 3HP. Various process configurations have also been proposed, resulting in improved conversion yields. The intense research efforts have resulted in the production of as much as 83.8 g/L 3HP from renewable carbon resources, and a system whereby 3-hydroxypropionitrile was converted to 3HP through whole-cell catalysis which resulted in 184.7 g/L 3HP. Although there are still challenges and difficulties that need to be addressed, the research results from the past four years have been an important step towards biological production of 3HP at the industrial level.

[THE PHYSICAL CHEMICAL, BIOLOGICAL BASICS OF CELLS ABSORPTION OF UNESTERIFIED FATTY ACIDS; ALBUMIN, CAVEOLIN, CLATHRIN AND LIPID-BINDING PROTEINS OF CYTOPLASM (THE LECTURE)].

Science.gov (United States)

Titov, V N; Shoibonov, B B

2016-03-01

From aposition of phylogenetic theory of general pathology, obesity and metabolic syndrome are pathology of fatty cells. However, the first is a pathology of phylogenetically early visceral fatty cells of omentum. They supply with substratum of energy realization of biologic function of trophology, homeostasis, endoecology and adaptation. The visceral fatty cells of omentum have no receptors to insulin and synthesize adaptively insulin and they are not characterized by biologic reaction of proliferation. The obesity is a pathology of late in phylogenesis subcutaneous adpocytes. They are insulin-dependent and supply with substratum of energy realization of one biologic function of locomotion--movement at the expense of constriction of cross-striated miocytes. The adipocytes in terms of adaptation synthesize humoral mediator adponectin and actively implement biologic function of proliferation. Under both aphysiologic conditions increases passive by gradient of concentration, absorption by cells albumin-unbound free fatty acids in unionized form in micellae's composition. The passive aphysiologic absorption of free fatty acids by cells which under intracellular compartmentalization don't oxidize mitochondria results in synthesis, accumulation of triglycerides in cytoplasm of cells which don't implement it physiologically. The aphysiologic absorption of free fatty acids by cells, their etherification in triglyceride, in particular, in phylogenetically late β-cells of islets and either late cardiomyocytes which fatty acids don't synthesize de novo results in development of aphysiologic processes and disorder of function. From position of biology, these cells in vivo are subjected to loss similar to apoptosis. The formation of corpuscles of apoptosis compromise biologic function of endoecology activating biologic reaction of inflammation.

Application of biological effective dose (BED) to estimate the duration of symptomatic relief and repopulation dose equivalent in palliative radiotherapy and chemotherapy

International Nuclear Information System (INIS)

Jones, Bleddyn; Cominos, Matilda; Dale, Roger G.

2003-01-01

Purpose: To investigate the potential for mathematic modeling in the assessment of symptom relief in palliative radiotherapy and cytotoxic chemotherapy. Methods: The linear quadratic model of radiation effect with the overall treatment time and the daily dose equivalent of repopulation is modified to include the regrowth time after completion of therapy. Results: The predicted times to restore the original tumor volumes after treatment are dependent on the biological effective dose (BED) delivered and the repopulation parameter (K); it is also possible to estimate K values from analysis of palliative treatment response durations. Hypofractionated radiotherapy given at a low total dose may produce long symptom relief in slow-growing tumors because of their low α/β ratios (which confer high fraction sensitivity) and their slow regrowth rates. Cancers that have high α/β ratios (which confer low fraction sensitivity), and that are expected to repopulate rapidly during therapy, are predicted to have short durations of symptom control. The BED concept can be used to estimate the equivalent dose of radiotherapy that will achieve the same duration of symptom relief as palliative chemotherapy. Conclusion: Relatively simple radiobiologic modeling can be used to guide decision-making regarding the choice of the most appropriate palliative schedules and has important implications in the design of radiotherapy or chemotherapy clinical trials. The methods described provide a rationalization for treatment selection in a wide variety of tumors

Potentiometric studies on ternary complexes involving some divalent transition metal ions, gallic acid and biologically abundant aliphatic dicarboxylic acids in aqueous solutions

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Abdelatty Mohamed Radalla

2015-06-01

Full Text Available Formation of binary and ternary complexes of the divalent transition metal ions, Cu2+, Ni2+, Co2+ and Zn2+ with gallic acid and the biologically important aliphatic dicarboxylic acids (adipic, succinic, malic, malonic, maleic, tartaric and oxalic acids were investigated by means of the potentiometric technique at 25 °C and I = 0.10 mol dm−3 NaNO3. The acid-base properties of the ligands were investigated and discussed. The acidity constants of gallic acid and aliphatic dicarboxylic acids were determined and used for determining the stability constants of the binary and ternary complexes formed in the aqueous medium under the above experimental conditions. The formation of the different 1:1 and 1:2 binary complexes and 1:1:1 ternary complexes are inferred from the corresponding potentiometric pH-metric titration curves. The ternary complex formation was found to occur in a stepwise manner. The stability constants of these binary and ternary systems were calculated. The values of Δ log K, percentage of relative stabilization (%R.S. and log X were evaluated and discussed. The concentration distribution of the various complex species formed in solution was evaluated and discussed. The mode of chelation of ternary complexes formed was ascertained by conductivity measurements.

Degradation characteristics of 2,4-dichlorophenoxyacetic acid in electro-biological system

Energy Technology Data Exchange (ETDEWEB)

Zhang, JingLi, E-mail: jinglizhangczp@126.com [Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Institute of Urban Construction, Tianjin 300384 (China); Cao, ZhanPing; Zhang, HongWei [School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China); Zhao, LianMei [Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Institute of Urban Construction, Tianjin 300384 (China); Sun, XuDong; Mei, Feng [School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

2013-11-15

Highlights: • The 2,4-D reductive degradation was studied in an electro-biological system. • The electric auxiliary accelerates 2,4-D microbial degradation. • A electron transfer is achieved between the electrode, bacteria and the pollutants. • The paper provides a promising way for the degradation of persistent organics. -- Abstract: The reductive degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in an electro-biological system, a biological system and an electric catalytic system, respectively. Electrochemical characteristics were monitored by cyclic voltammetry and the intermediate products of 2,4-D degradation were determined by high speed liquid chromatography (HPLC). The results showed that all 2,4-D degradations in the three systems conformed to the kinetics characteristics of one-order reaction, and the degradation kinetics constants were 28.74 × 10{sup −2} h{sup −1}, 19.73 × 10{sup −2} h{sup −1} and 3.54 × 10{sup −2} h{sup −1}, respectively. The kinetics constant in the electro-biological system was higher than the sum in the other two systems by 19%. The electrochemical assistance provided the electrons and accelerated the electron transfer rate in the microbial degradation of 2,4-D. The degradation resulted from the microbial reduction strengthened by the electrochemical assistance. The electron transfer existed between the electrode, cytochrome, NAD and the pollutants. A long-range electron transfer process could be achieved on the multi-phase interfaces between the electrode, bacteria and the pollutants.

Simulated Response of a Tissue-equivalent Proportional Counter on the Surface of Mars.

Science.gov (United States)

Northum, Jeremy D; Guetersloh, Stephen B; Braby, Leslie A; Ford, John R

2015-10-01

Uncertainties persist regarding the assessment of the carcinogenic risk associated with galactic cosmic ray (GCR) exposure during a mission to Mars. The GCR spectrum peaks in the range of 300(-1) MeV n to 700 MeV n(-1) and is comprised of elemental ions from H to Ni. While Fe ions represent only 0.03% of the GCR spectrum in terms of particle abundance, they are responsible for nearly 30% of the dose equivalent in free space. Because of this, radiation biology studies focusing on understanding the biological effects of GCR exposure generally use Fe ions. Acting as a thin shield, the Martian atmosphere alters the GCR spectrum in a manner that significantly reduces the importance of Fe ions. Additionally, albedo particles emanating from the regolith complicate the radiation environment. The present study uses the Monte Carlo code FLUKA to simulate the response of a tissue-equivalent proportional counter on the surface of Mars to produce dosimetry quantities and microdosimetry distributions. The dose equivalent rate on the surface of Mars was found to be 0.18 Sv y(-1) with an average quality factor of 2.9 and a dose mean lineal energy of 18.4 keV μm(-1). Additionally, albedo neutrons were found to account for 25% of the dose equivalent. It is anticipated that these data will provide relevant starting points for use in future risk assessment and mission planning studies.

Dual Causality and the Autonomy of Biology.

Science.gov (United States)

Bock, Walter J

2017-03-01

Ernst Mayr's concept of dual causality in biology with the two forms of causes (proximate and ultimate) continues to provide an essential foundation for the philosophy of biology. They are equivalent to functional (=proximate) and evolutionary (=ultimate) causes with both required for full biological explanations. The natural sciences can be classified into nomological, historical nomological and historical dual causality, the last including only biology. Because evolutionary causality is unique to biology and must be included for all complete biological explanations, biology is autonomous from the physical sciences.

Biological and pharmacological effects of Delphinium elbursense ...

African Journals Online (AJOL)

The total phenolic compounds in extract were determined as gallic acid equivalents (52.24 ± 1.7) and total flavonoid contents were calculated as quercetin equivalents (17.26 ± 0.6) from a calibration curve. Keywords: Antidepressant, antihypoxic, Delphinium elbursense, flavonoid contents, forced swimming test, medicinal ...

Oleanolic Acid and Its Derivatives: Biological Activities and Therapeutic Potential in Chronic Diseases

Directory of Open Access Journals (Sweden)

Taiwo Betty Ayeleso

2017-11-01

Full Text Available The increasing demand for natural products as an alternative therapy for chronic diseases has encouraged research into the pharmacological importance of bioactive compounds from plants. Recently, there has been a surge of interest in the therapeutic potential of oleanolic acid (OA in the prevention and management of chronic diseases. Oleanolic acid is a pentacyclic triterpenoid widely found in plants, including fruits and vegetables with different techniques and chromatography platforms being employed in its extraction and isolation. Several studies have demonstrated the potential therapeutic effects of OA on different diseases and their symptoms. Furthermore, oleanolic acid also serves as a framework for the development of novel semi-synthetic triterpenoids that could prove vital in finding therapeutic modalities for various ailments. There are recent advances in the design and synthesis of chemical derivatives of OA to enhance its solubility, bioavailability and potency. Some of these derivatives have also been therapeutic candidates in a number of clinical trials. This review consolidates and expands on recent reports on the biological effects of oleanolic acid from different plant sources and its synthetic derivatives as well as their mechanisms of action in in vitro and in vivo study models. This review suggests that oleanolic acid and its derivatives are important candidates in the search for alternative therapy in the treatment and management of chronic diseases.

Effects of sulphuric acid pollution on the biology of streams in the Transvaal, South Africa

Energy Technology Data Exchange (ETDEWEB)

Harrison, A D

1958-01-01

Strongly acid effluents or drainage waters are produced during gold and coal mining activities in the Transvaal. Sulphuric acid is produced during oxidation of pyrites exposed by mining operations and much of it finds its way into streams and creates serious pollution problems. The object of this paper is to give a short account of the effects of this acid pollution on the biology of these streams. The first streams considered are the Klip and Klipspruit near their confluence at Olifantsvlei, near Johannesburg. These were studied during a two-year investigation of the area. Both receive acid pollution from gold mine dumps and slimes dams, the seepages from which have pH values as low as 2.3. Both streams run over dolomite formations so the acid is gradually neutralised but highly mineralised, permanently hard water results. The Klip and the Klipspruit join in the middle of a y-shaped, swampy area, each stream coming down one of the upper arms of the y. A sampling station was set up on each where it runs slowly through the swamp just before confluence.

[Genotoxic modification of nucleic acid bases and biological consequences of it. Review and prospects of experimental and computational investigations

Science.gov (United States)

Poltev, V. I.; Bruskov, V. I.; Shuliupina, N. V.; Rein, R.; Shibata, M.; Ornstein, R.; Miller, J.

1993-01-01

The review is presented of experimental and computational data on the influence of genotoxic modification of bases (deamination, alkylation, oxidation) on the structure and biological functioning of nucleic acids. Pathways are discussed for the influence of modification on coding properties of bases, on possible errors of nucleic acid biosynthesis, and on configurations of nucleotide mispairs. The atomic structure of nucleic acid fragments with modified bases and the role of base damages in mutagenesis and carcinogenesis are considered.

Investigation of the effect of biologically active threo-Ds-isocitric acid on oxidative stress in Paramecium caudatum.

Science.gov (United States)

Morgunov, Igor G; Karpukhina, Olga V; Kamzolova, Svetlana V; Samoilenko, Vladimir A; Inozemtsev, Anatoly N

2018-01-02

The effect of biologically active form (threo-Ds-) of isocitric acid (ICA) on oxidative stress was studied using the infusorian Paramecium caudatum stressed by hydrogen peroxide and salts of some heavy metals (Cu, Pb, Zn, and Cd). ICA at concentrations between 0.5 and 10 mM favorably influenced the infusorian cells with oxidative stress induced by the toxicants studied. The maximal antioxidant effect of ICA was observed at its concentration 10 mM irrespective of the toxicant used (either H 2 O 2 or heavy metal ions). ICA was found to be a more active antioxidant than ascorbic acid. Biologically active pharmaceutically pure threo-Ds-ICA was produced through cultivation of the yeast Yarrowia lipolytica and isolated from the culture liquid in the form of crystalline monopotassium salt with a purity of 99.9%.

Synthesis, Crystal Structure and Biological Activities of Novel Anthranilic(Isophthalic) Acid Esters

Institute of Scientific and Technical Information of China (English)

YAN Tao; YU Guan-ping; LIU Peng-fei; XIONG Li-xia; YU Shu-jing; LI Zheng-ming

2012-01-01

In search of environmentally benign insecticides with high activity,low toxicity and low resistance,a series of novel anthranilic(isophthalic) acid esters was designed and synthesized based on the structure of ryanodine modulating agent.All the compounds were characterized by 1H NMR spectra,elemental analysis or high resolution mass spectrometry(HRMS).The preliminary results of biological activity assessment indicate that some of the title compounds exhibit certain but unremarkable insecticidal activity against Mythimna separata Walker at 200 mg/L and fungicidal activities against five funguses at 50 mg/L.

Determination of dose equivalent with tissue-equivalent proportional counters

International Nuclear Information System (INIS)

Dietze, G.; Schuhmacher, H.; Menzel, H.G.

1989-01-01

Low pressure tissue-equivalent proportional counters (TEPC) are instruments based on the cavity chamber principle and provide spectral information on the energy loss of single charged particles crossing the cavity. Hence such detectors measure absorbed dose or kerma and are able to provide estimates on radiation quality. During recent years TEPC based instruments have been developed for radiation protection applications in photon and neutron fields. This was mainly based on the expectation that the energy dependence of their dose equivalent response is smaller than that of other instruments in use. Recently, such instruments have been investigated by intercomparison measurements in various neutron and photon fields. Although their principles of measurements are more closely related to the definition of dose equivalent quantities than those of other existing dosemeters, there are distinct differences and limitations with respect to the irradiation geometry and the determination of the quality factor. The application of such instruments for measuring ambient dose equivalent is discussed. (author)

Measurement of formic acid, acetic acid and hydroxyacetaldehyde, hydrogen peroxide, and methyl peroxide in air by chemical ionization mass spectrometry: airborne method development

Science.gov (United States)

Treadaway, Victoria; Heikes, Brian G.; McNeill, Ashley S.; Silwal, Indira K. C.; O'Sullivan, Daniel W.

2018-04-01

A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described and optimized for quantitative gas-phase measurements of hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HCOOH), and the sum of acetic acid (CH3COOH) and hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation and methodology were designed for airborne in situ field measurements. The CIMS quantification of formic acid, acetic acid, and hydroxyacetaldehyde used I- cluster formation to produce and detect the ion clusters I-(HCOOH), I-(CH3COOH), and I-(HOCH2CHO), respectively. The CIMS also produced and detected I- clusters with hydrogen peroxide and methyl peroxide, I-(H2O2) and I-(CH3OOH), though the sensitivity was lower than with the O2- (CO2) and O2- ion clusters, respectively. For that reason, while the I- peroxide clusters are presented, the focus is on the organic acids. Acetic acid and hydroxyacetaldehyde were found to yield equivalent CIMS responses. They are exact isobaric compounds and indistinguishable in the CIMS used. Consequently, their combined signal is referred to as the acetic acid equivalent sum. Within the resolution of the quadrupole used in the CIMS (1 m/z), ethanol and 1- and 2-propanol were potential isobaric interferences to the measurement of formic acid and the acetic acid equivalent sum, respectively. The CIMS response to ethanol was 3.3 % that of formic acid and the response to either 1- or 2-propanol was 1 % of the acetic acid response; therefore, the alcohols were not considered to be significant interferences to formic acid or the acetic acid equivalent sum. The multi-reagent ion system was successfully deployed during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) in 2014. The combination of FRAPPÉ and laboratory calibrations allowed for the post-mission quantification of formic acid and the acetic acid equivalent sum observed during the Deep

Biological regeneration of humic acid-loaded partially exhausted activated carbon (down flow system)

International Nuclear Information System (INIS)

Durrani, M.A.Q.J.; Martin, R.J.; Khaliq, F.

1995-01-01

This paper represents the report on the biological regeneration of partially exhausted (down flow) activated carbon following the experimental studies carried out at the university of Birmingham, UK. The Research investigated the extent of bio regeneration of humic acid of concentration 100 mg/l. Bio regeneration in the partial exhaustion system (down flow) was evaluated in terms of substrate removal. Bacterial counts in the effluents of regenerated GAC columns were significantly more than those of fresh carbon effluents. The regeneration performance of the bio regeneration, partially exhausted (with humic acid) carbon increased during initial cycles, later on, it deteriorated significantly with each successive regeneration cycle. Microbial fouling of the carbon, especially at the bottom of the carbon bed was found to produce a substantial deterioration of the bio regeneration performance. (author)

The nucleic acid revolution continues - will forensic biology become forensic molecular biology?

Science.gov (United States)

Gunn, Peter; Walsh, Simon; Roux, Claude

2014-01-01

Molecular biology has evolved far beyond that which could have been predicted at the time DNA identity testing was established. Indeed we should now perhaps be referring to "forensic molecular biology." Aside from DNA's established role in identifying the "who" in crime investigations, other developments in medical and developmental molecular biology are now ripe for application to forensic challenges. The impact of DNA methylation and other post-fertilization DNA modifications, plus the emerging role of small RNAs in the control of gene expression, is re-writing our understanding of human biology. It is apparent that these emerging technologies will expand forensic molecular biology to allow for inferences about "when" a crime took place and "what" took place. However, just as the introduction of DNA identity testing engendered many challenges, so the expansion of molecular biology into these domains will raise again the issues of scientific validity, interpretation, probative value, and infringement of personal liberties. This Commentary ponders some of these emerging issues, and presents some ideas on how they will affect the conduct of forensic molecular biology in the foreseeable future.

Toward Synthetic Biology Strategies for Adipic Acid Production: An in Silico Tool for Combined Thermodynamics and Stoichiometric Analysis of Metabolic Networks

DEFF Research Database (Denmark)

Averesch, Nils J. H.; Martínez, Verónica S.; Nielsen, Lars K.

2018-01-01

Adipic acid, a nylon-6,6 precursor, has recently gained popularity in synthetic biology. Here, 16 different production routes to adipic acid were evaluated using a novel tool for network-embedded thermodynamic analysis of elementary flux modes. The tool distinguishes between thermodynamically...

New Insights Into the Mechanisms and Biological Roles of D-Amino Acids in Complex Eco-Systems

Science.gov (United States)

Aliashkevich, Alena; Alvarez, Laura; Cava, Felipe

2018-01-01

In the environment bacteria share their habitat with a great diversity of organisms, from microbes to humans, animals and plants. In these complex communities, the production of extracellular effectors is a common strategy to control the biodiversity by interfering with the growth and/or viability of nearby microbes. One of such effectors relies on the production and release of extracellular D-amino acids which regulate diverse cellular processes such as cell wall biogenesis, biofilm integrity, and spore germination. Non-canonical D-amino acids are mainly produced by broad spectrum racemases (Bsr). Bsr’s promiscuity allows it to generate high concentrations of D-amino acids in environments with variable compositions of L-amino acids. However, it was not clear until recent whether these molecules exhibit divergent functions. Here we review the distinctive biological roles of D-amino acids, their mechanisms of action and their modulatory properties of the biodiversity of complex eco-systems. PMID:29681896

Synthesis and biological activity of oxytocin analogues containing unnatural amino acids in position 9: structure activity study

Czech Academy of Sciences Publication Activity Database

Magafa, V.; Borovičková, Lenka; Slaninová, Jiřina; Cordopatis, P.

2010-01-01

Roč. 38, č. 5 (2010), s. 1549-1559 ISSN 0939-4451 Institutional research plan: CEZ:AV0Z40550506 Keywords : oxytocin antagonists * position 9 * unnatural amino acids * biological activity Subject RIV: CC - Organic Chemistry Impact factor: 4.106, year: 2010

Biological evaluation of dopamine analogues containing phenylboronic acid group as new boron carriers

International Nuclear Information System (INIS)

Ito, Y.; Mizuno, T.; Yoshino, K.; Ban, H.S.; Nakamura, H.; Hiratsuka, J.; Ishikawa, A.; Ohki, H.

2011-01-01

As new BNCT reagents, we designed and synthesized dopamine analogues containing phenylboronic acid group, N-3,4-dihydroxyphenethyl-4-dihydroxyborylbenzamide (dopamine–PCBA) and N-[2-(3,4-dihydroxyphenetyl)ethyl]-3-(4-dihydroxyborylphenyl)promionamide (dopamine–CEBA). The efficacies of these compounds have not been investigated for biological samples. Therefore we have carried out experiments with cultured tumor cells and tumor-bearing mice, and evaluated possibility of these compounds as boron carriers. Dopamine–PCBA and dopamine–CEBA were synthesized by coupling between p-carboxyphenylboronic acid (PCBA) or 4-(2-carboxyethyl)benzeneboronic acid (CEBA) and 3,4-(dibenzyloxy)phenethylamine hydrochloride (DBPA-HCl) followed by catalytic hydrogenation using Pd catalyst. The effect of compounds on cell vitality was determined by MTT assay in various cells. In vivo biodistribution of compounds was determined in Balb/c and DDY mice in bearing implanted CT26 cells. These results have demonstrated that dopamine–CEBA was less toxic. - Highlights: ► Dopamine analogues containing phenylboronic acid are synthesized as BNCT reagents. ► Their cytotoxicity is almost lower than that of BSH. ► Boron uptake with dopamine–PCBA is larger than that of BSH. ► Dopamine analogs showed lesser boron accumulation property into spleen than BPA.

Emission of nitrous acid from soil and biological soil crusts as a major source of atmospheric HONO on Cyprus

Science.gov (United States)

Meusel, Hannah; Tamm, Alexandra; Wu, Dianming; Kuhn, Uwe; Leifke, Anna-Lena; Weber, Bettina; Su, Hang; Lelieveld, Jos; Hoffmann, Thorsten; Pöschl, Ulrich; Cheng, Yafang

2017-04-01

Elucidation of the sources and atmospheric chemistry of nitrous acid (HONO) is highly relevant, as HONO is an important precursor of OH radicals. Up to 30% of the OH budget are formed by photolysis of HONO, whereas major fractions of HONO measured in the field derive from yet unidentified sources. Heterogeneous conversion of nitrogen dioxide (NO2) to HONO on a variety of surfaces (soot, humic acid aerosol) is assumed to be a major HONO source (Stemmler et al., 2007, Ammann et al., 1998). In rural regions, however, NO2 concentrations were found to be too low to explain observed HONO concentrations, as e.g., in the case of a recent field study on the Mediterranean island of Cyprus (Meusel et al., 2016). In this study a good correlation between missing sources of HONO and nitrogen oxide (NO) was found indicating a common origin of both reactive nitrogen compounds. Simultaneous emission of HONO and NO from soil was reported earlier (Oswald et al., 2013), and enhanced emission rates were found when soil was covered by biological soil crusts in arid and semi-arid ecosystems (Weber et al., 2015). In the present study we measured HONO and NO emissions of 43 soil and soil crust samples from Cyprus during full wetting and drying cycles under controlled laboratory conditions by means of a dynamic chamber system. The observed range of HONO and NO emissions was in agreement with earlier studies, but unlike the study of Weber et al. (2015), we found highest emission from bare soil, followed by soil covered by light and dark cyanobacteria-dominated biological soil crusts. Emission rates correlated well with the nitrite and nitrate contents of soil and biological soil crust samples, and higher nutrient contents of bare soil samples, as compared to the previous biological soil crust study, explain the higher bare soil emissions. Integrating the emission rates of bare soil and the different types of biological soil crusts, based on their local relative abundance, the calculated

Conductivity studies on commercially available proton-conducting membranes with different equivalent weight

Energy Technology Data Exchange (ETDEWEB)

Huslage, J; Buechi, F N; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

Two perfluorosulfonic acid membranes, Nafion{sup R} 105 and Nafion{sup R} 115 with the same thickness but different equivalent weights (EW = 1000 g/eq. resp. 1100 g/eq.) were characterised by conductivity measurements at different water vapour activities in the temperature range of 25-70{sup o}C. The results demonstrate that a lower membrane equivalent weight opens the possibility to obtain the needed proton conductivity at lower water vapour activity. This is especially important for those fuel cell applications, in which the cell is operated without external humidification of the fuel gases. (author) 5 figs., 5 refs.

Measurement of acid dissociation constants of weak acids by cation exchange and conductometry

Energy Technology Data Exchange (ETDEWEB)

Dasgupta, P.K.; Nara, Osamu (Texas Tech Univ., Lubbock (USA))

1990-06-01

A simple strategy is presented for the determination of acid dissociation constants based on the measurement of conductance of a known concentration of the acid and/or the conductance of a solution of its fully or partially neutralized alkali-metal salts. For an n-protic acid, 2n conductance measurements are minimally necessary. In the simplest case of a typical monoprotic acid, the conductance of its alkali salt solution is measured before and after passage through an H{sup +}-form exchanger. From these data both the pK{sub a} of the acid and the equivalent conductance of the anion can be computed. The underlying equations are rigorously solved for monoprotic acids and some diprotic acid systems. For other diprotic and multiprotic acid systems, initial estimates are obtained by making approximations; the complete data set is then subjected to multiparametric fitting. The method does not require pH measurements; conductance can generally be measured accurately at low enough ionic strengths to obviate the need for major activity correction. Several experimental measurements are presented and excellent agreement with literature pK{sub a} values is observed. The reliability of the equivalent conductance values computed in this fashion is limited, however.

Synthesis, physicochemical and biological properties of poly-α-amino acids - the simplest of protein models

International Nuclear Information System (INIS)

Katchalski-Katzir, Ephraim

1996-01-01

During the 1950s, linear and multichain poly-α-amino acids were synthesized by polymerization of the corresponding N-carboxy-amino acid anhydrides in solution in the presence of suitable catalysts. The resulting homo- and heteropolymers have since been widely employed as simple protein models. Under appropriate conditions, poly-α-amino acids, in the solid state and in solution, were found to acquire conformations of an α-helix and β-parallel and antiparallel pleased sheets, or to exist as random coils. Their use in experimental and theoretical investigations of helix-coil transitions helped to shed new light on the mechanisms involved in protein denaturation. Poly-α-amino acids played an important role in the deciphering of the genetic code. In addition, analysis of the antigenicity of poly-α-amino acids led to the clucidation of the factors determining the antigenicity of proteins and peptides. Interest in the biological and physicochemical characteristics of poly-α-amino acids was recently renewed because of the reported novel finding that some copolymers of amino acids are effective as drugs in multiple sclerosis, and that glutamine repeats and reiteration of other amino acids occur in inherited neurodegenerative diseases. The presence of repeating sequences of amino acids in proteins, and of nucleotides in DNA, raises many interesting questions about their respective roles in determining protein structure and function, and gene performance and regulation. (author). 35 refs, 3 figs, 2 tabs

Remediation of a winery wastewater combining aerobic biological oxidation and electrochemical advanced oxidation processes.

Science.gov (United States)

Moreira, Francisca C; Boaventura, Rui A R; Brillas, Enric; Vilar, Vítor J P

2015-05-15

Apart from a high biodegradable fraction consisting of organic acids, sugars and alcohols, winery wastewaters exhibit a recalcitrant fraction containing high-molecular-weight compounds as polyphenols, tannins and lignins. In this context, a winery wastewater was firstly subjected to a biological oxidation to mineralize the biodegradable fraction and afterwards an electrochemical advanced oxidation process (EAOP) was applied in order to mineralize the refractory molecules or transform them into simpler ones that can be further biodegraded. The biological oxidation led to above 97% removals of dissolved organic carbon (DOC), chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD5), but was inefficient on the degradation of a bioresistant fraction corresponding to 130 mg L(-1) of DOC, 380 mg O2 L(-1) of COD and 8.2 mg caffeic acid equivalent L(-1) of total dissolved polyphenols. Various EAOPs such as anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF), UVA photoelectro-Fenton (PEF) and solar PEF (SPEF) were then applied to the recalcitrant effluent fraction using a 2.2 L lab-scale flow plant containing an electrochemical cell equipped with a boron-doped diamond (BDD) anode and a carbon-PTFE air-diffusion cathode and coupled to a photoreactor with compound parabolic collectors (CPCs). The influence of initial Fe(2+) concentration and current density on the PEF process was evaluated. The relative oxidative ability of EAOPs increased in the order AO-H2O2 < EF < PEF ≤ SPEF. The SPEF process using an initial Fe(2+) concentration of 35 mg L(-1), current density of 25 mA cm(-2), pH of 2.8 and 25 °C reached removals of 86% on DOC and 68% on COD after 240 min, regarding the biologically treated effluent, along with energy consumptions of 45 kWh (kg DOC)(-1) and 5.1 kWh m(-3). After this coupled treatment, color, odor, COD, BOD5, NH4(+), NO3(-) and SO4(2-) parameters complied with the legislation targets and, in addition, a total

Radiobiological equivalent of low/high dose rate brachytherapy and evaluation of tumor and normal responses to the dose.

Science.gov (United States)

Manimaran, S

2007-06-01

The aim of this study was to compare the biological equivalent of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy in terms of the more recent linear quadratic (LQ) model, which leads to theoretical estimation of biological equivalence. One of the key features of the LQ model is that it allows a more systematic radiobiological comparison between different types of treatment because the main parameters alpha/beta and micro are tissue-specific. Such comparisons also allow assessment of the likely change in the therapeutic ratio when switching between LDR and HDR treatments. The main application of LQ methodology, which focuses on by increasing the availability of remote afterloading units, has been to design fractionated HDR treatments that can replace existing LDR techniques. In this study, with LDR treatments (39 Gy in 48 h) equivalent to 11 fractions of HDR irradiation at the experimental level, there are increasing reports of reproducible animal models that may be used to investigate the biological basis of brachytherapy and to help confirm theoretical predictions. This is a timely development owing to the nonavailability of sufficient retrospective patient data analysis. It appears that HDR brachytherapy is likely to be a viable alternative to LDR only if it is delivered without a prohibitively large number of fractions (e.g., fewer than 11). With increased scientific understanding and technological capability, the prospect of a dose equivalent to HDR brachytherapy will allow greater utilization of the concepts discussed in this article.

Biological activity of alligator, avian, and mammalian insulin in juvenile alligators: plasma glucose and amino acids.

Science.gov (United States)

Lance, V A; Elsey, R M; Coulson, R A

1993-02-01

The biological activity of alligator, turkey, and bovine insulin on plasma glucose and plasma amino acids was tested in fasted juvenile alligators. Preliminary experiments showed that the stress associated with taking the initial blood sample resulted in a hyperglycemic response lasting more than 24 hr. Despite repeated bleedings no additional hyperglycemic events occurred, and blood glucose declined slowly over the next 7 days. Under these conditions the smallest dose of insulin eliciting a hypoglycemic response was 40 micrograms/kg body wt. A dose of 400 micrograms/kg body wt of either alligator or bovine insulin caused a pronounced hypoglycemia by 12 hr postinjection. Maximum decline in plasma glucose occurred at 24 to 36 hr with a slow return to control levels by 120 hr. There were no significant differences in the hypoglycemic responses to any of the three insulins tested. The decline in plasma amino acids was much more rapid than the decline in plasma glucose in response to insulin. Even at the 40 micrograms/kg body wt dose a significant difference from saline-injected control was seen at 2 hr postinjection. Maximum decline in plasma amino acids occurred at 8 to 12 hr with a return to baseline by 36 hr. These results show that the relatively conservative changes in the sequence of alligator insulin (three amino acid substitutions in the B-chain compared with that of chicken) have little effect on biological activity and that alligator insulin receptors do not appear to discriminate among the three insulins.

Equivalent Dynamic Models.

Science.gov (United States)

Molenaar, Peter C M

2017-01-01

Equivalences of two classes of dynamic models for weakly stationary multivariate time series are discussed: dynamic factor models and autoregressive models. It is shown that exploratory dynamic factor models can be rotated, yielding an infinite set of equivalent solutions for any observed series. It also is shown that dynamic factor models with lagged factor loadings are not equivalent to the currently popular state-space models, and that restriction of attention to the latter type of models may yield invalid results. The known equivalent vector autoregressive model types, standard and structural, are given a new interpretation in which they are conceived of as the extremes of an innovating type of hybrid vector autoregressive models. It is shown that consideration of hybrid models solves many problems, in particular with Granger causality testing.

New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy.

Science.gov (United States)

Thétiot-Laurent, Sophie; Gosset, Gaëlle; Clément, Jean-Louis; Cassien, Mathieu; Mercier, Anne; Siri, Didier; Gaudel-Siri, Anouk; Rockenbauer, Antal; Culcasi, Marcel; Pietri, Sylvia

2017-02-01

There is increasing interest in measuring pH in biological samples by using nitroxides with pH-dependent electron paramagnetic resonance (EPR) spectra. Aiming to improve the spectral sensitivity (Δa X ) of these probes (i.e., the difference between the EPR hyperfine splitting (hfs) in their protonated and unprotonated forms), we characterized a series of novel linear α-carboxy, α'-diethoxyphosphoryl nitroxides constructed on an amino acid core and featuring an (α or α')-C-H bond. In buffer, the three main hfs (a N , a H , and a P ) of their EPR spectra vary reversibly with pH and, from a P or a H titration curves, a two- to fourfold increase in sensitivity was achieved compared to reference imidazoline or imidazolidine nitroxides. The crystallized carboxylate 10 b (pK a ≈3.6), which demonstrated low cytotoxicity and good resistance to bioreduction, was applied to probe stomach acidity in rats. The results pave the way to a novel generation of highly sensitive EPR pH markers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A first vascularized skin equivalent as an alternative to animal experimentation.

Science.gov (United States)

Groeber, Florian; Engelhardt, Lisa; Lange, Julia; Kurdyn, Szymon; Schmid, Freia F; Rücker, Christoph; Mielke, Stephan; Walles, Heike; Hansmann, Jan

2016-01-01

Tissue-engineered skin equivalents mimic key aspects of the human skin, and can thus be employed as wound coverage for large skin defects or as in vitro test systems as an alternative to animal models. However, current skin equivalents lack a functional vasculature limiting clinical and research applications. This study demonstrates the generation of a vascularized skin equivalent with a perfused vascular network by combining a biological vascularized scaffold (BioVaSc) based on a decellularized segment of a porcine jejunum and a tailored bioreactor system. Briefly, the BioVaSc was seeded with human fibroblasts, keratinocytes, and human microvascular endothelial cells. After 14 days at the air-liquid interface, hematoxylin & eosin and immunohistological staining revealed a specific histological architecture representative of the human dermis and epidermis including a papillary-like architecture at the dermal-epidermal-junction. The formation of the skin barrier was measured non-destructively using impedance spectroscopy. Additionally, endothelial cells lined the walls of the formed vessels that could be perfused with a physiological volume flow. Due to the presence of a complex in-vivo-like vasculature, the here shown skin equivalent has the potential for skin grafting and represents a sophisticated in vitro model for dermatological research.

Calculation of integrated biological response in brachytherapy

International Nuclear Information System (INIS)

Dale, Roger G.; Coles, Ian P.; Deehan, Charles; O'Donoghue, Joseph A.

1997-01-01

Purpose: To present analytical methods for calculating or estimating the integrated biological response in brachytherapy applications, and which allow for the presence of dose gradients. Methods and Materials: The approach uses linear-quadratic (LQ) formulations to identify an equivalent biologically effective dose (BED eq ) which, if applied to a specified tissue volume, would produce the same biological effect as that achieved by a given brachytherapy application. For simple geometrical cases, BED multiplying factors have been derived which allow the equivalent BED for tumors to be estimated from a single BED value calculated at a dose reference point. For more complex brachytherapy applications a voxel-by-voxel determination of the equivalent BED will be more accurate. Equations are derived which when incorporated into brachytherapy software would facilitate such a process. Results: At both high and low dose rates, the BEDs calculated at the dose reference point are shown to be lower than the true values by an amount which depends primarily on the magnitude of the prescribed dose; the BED multiplying factors are higher for smaller prescribed doses. The multiplying factors are less dependent on the assumed radiobiological parameters. In most clinical applications involving multiple sources, particularly those in multiplanar arrays, the multiplying factors are likely to be smaller than those derived here for single sources. The overall suggestion is that the radiobiological consequences of dose gradients in well-designed brachytherapy treatments, although important, may be less significant than is sometimes supposed. The modeling exercise also demonstrates that the integrated biological effect associated with fractionated high-dose-rate (FHDR) brachytherapy will usually be different from that for an 'equivalent' continuous low-dose-rate (CLDR) regime. For practical FHDR regimes involving relatively small numbers of fractions, the integrated biological effect to

Five Decades with Polyunsaturated Fatty Acids: Chemical Synthesis, Enzymatic Formation, Lipid Peroxidation and Its Biological Effects

Directory of Open Access Journals (Sweden)

Angel Catalá

2013-01-01

Full Text Available I have been involved in research on polyunsaturated fatty acids since 1964 and this review is intended to cover some of the most important aspects of this work. Polyunsaturated fatty acids have followed me during my whole scientific career and I have published a number of studies concerned with different aspects of them such as chemical synthesis, enzymatic formation, metabolism, transport, physical, chemical, and catalytic properties of a reconstructed desaturase system in liposomes, lipid peroxidation, and their effects. The first project I became involved in was the organic synthesis of [1-14C] eicosa-11,14-dienoic acid, with the aim of demonstrating the participation of that compound as a possible intermediary in the biosynthesis of arachidonic acid “in vivo.” From 1966 to 1982, I was involved in several projects that study the metabolism of polyunsaturated fatty acids. In the eighties, we studied fatty acid binding protein. From 1990 up to now, our laboratory has been interested in the lipid peroxidation of biological membranes from various tissues and different species as well as liposomes prepared with phospholipids rich in PUFAs. We tested the effect of many antioxidants such as alpha tocopherol, vitamin A, melatonin and its structural analogues, and conjugated linoleic acid, among others.

Modeling of biologically motivated self-learning equivalent-convolutional recurrent-multilayer neural structures (BLM_SL_EC_RMNS) for image fragments clustering and recognition

Science.gov (United States)

Krasilenko, Vladimir G.; Lazarev, Alexander A.; Nikitovich, Diana V.

2018-03-01

The biologically-motivated self-learning equivalence-convolutional recurrent-multilayer neural structures (BLM_SL_EC_RMNS) for fragments images clustering and recognition will be discussed. We shall consider these neural structures and their spatial-invariant equivalental models (SIEMs) based on proposed equivalent two-dimensional functions of image similarity and the corresponding matrix-matrix (or tensor) procedures using as basic operations of continuous logic and nonlinear processing. These SIEMs can simply describe the signals processing during the all training and recognition stages and they are suitable for unipolar-coding multilevel signals. The clustering efficiency in such models and their implementation depends on the discriminant properties of neural elements of hidden layers. Therefore, the main models and architecture parameters and characteristics depends on the applied types of non-linear processing and function used for image comparison or for adaptive-equivalent weighing of input patterns. We show that these SL_EC_RMNSs have several advantages, such as the self-study and self-identification of features and signs of the similarity of fragments, ability to clustering and recognize of image fragments with best efficiency and strong mutual correlation. The proposed combined with learning-recognition clustering method of fragments with regard to their structural features is suitable not only for binary, but also color images and combines self-learning and the formation of weight clustered matrix-patterns. Its model is constructed and designed on the basis of recursively continuous logic and nonlinear processing algorithms and to k-average method or method the winner takes all (WTA). The experimental results confirmed that fragments with a large numbers of elements may be clustered. For the first time the possibility of generalization of these models for space invariant case is shown. The experiment for an images of different dimensions (a reference

Metabolomic fingerprinting of primed tobacco cells provide the first evidence for the biological origin of cis-chlorogenic acid

CSIR Research Space (South Africa)

Mhlongo, MI

2015-01-01

Full Text Available . Very little, however, is known about the biological significance and origin of cis-isomers. Here we show for the first time the accumulation of cis-5-caffeoylquinic acid in cultured tobacco cells treated with different inducers of plant defence...

Reducing and verifying haloacetic acids in treated drinking water using a biological filter system.

Science.gov (United States)

Lou, Jie C; Chan, Hung Y; Yang, Chih Y; Tseng, Wei B; Han, Jia Y

2014-01-01

This study focused on reducing the haloacetic acid (HAA) concentrations in treated drinking water. HAA has been thought to be one possible nutrient supporting heterotrophic bacteria regrowth in drinking water. In this study, experiments were conducted using a pilot-scale system to evaluate the efficiency of biological filters (BF) for reducing excess HAA concentrations in water. The BF system reduced the total HAA concentration and the concentrations of five HAA species in the water. Dichloroacetic acid (DCAA), monobromoacetic acid (MBAA) and dibromoacetic acid (DBAA) were the three main HAA5 species that were present in the treated drinking water in this investigation. Combined, these three species represent approximately 77% of the HAA5 in the finished water after BF. The verification of the empirical HAA equation for the outlet in the BF system indicated linear relationships with high correlation coefficients. The empirical equation for the HAA5 concentrations in the finished water was established by examining other nutrients (e.g., dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm wavelength (UV254), and ammonia nitrogen) that can reduce pathogenic contamination. These findings may be useful for designing advanced processes for conventional water treatment plants or for managing water treatment and distribution systems for providing high-quality drinking water.

Antibacterial Free Fatty Acids and Monoglycerides: Biological Activities, Experimental Testing, and Therapeutic Applications

Science.gov (United States)

Yoon, Bo Kyeong; Jackman, Joshua A.; Valle-González, Elba R.

2018-01-01

Antimicrobial lipids such as fatty acids and monoglycerides are promising antibacterial agents that destabilize bacterial cell membranes, causing a wide range of direct and indirect inhibitory effects. The goal of this review is to introduce the latest experimental approaches for characterizing how antimicrobial lipids destabilize phospholipid membranes within the broader scope of introducing current knowledge about the biological activities of antimicrobial lipids, testing strategies, and applications for treating bacterial infections. To this end, a general background on antimicrobial lipids, including structural classification, is provided along with a detailed description of their targeting spectrum and currently understood antibacterial mechanisms. Building on this knowledge, different experimental approaches to characterize antimicrobial lipids are presented, including cell-based biological and model membrane-based biophysical measurement techniques. Particular emphasis is placed on drawing out how biological and biophysical approaches complement one another and can yield mechanistic insights into how the physicochemical properties of antimicrobial lipids influence molecular self-assembly and concentration-dependent interactions with model phospholipid and bacterial cell membranes. Examples of possible therapeutic applications are briefly introduced to highlight the potential significance of antimicrobial lipids for human health and medicine, and to motivate the importance of employing orthogonal measurement strategies to characterize the activity profile of antimicrobial lipids. PMID:29642500

EQUIVALENCE VERSUS NON-EQUIVALENCE IN ECONOMIC TRANSLATION

Directory of Open Access Journals (Sweden)

Cristina, Chifane

2012-01-01

Full Text Available This paper aims at highlighting the fact that “equivalence” represents a concept worth revisiting and detailing upon when tackling the translation process of economic texts both from English into Romanian and from Romanian into English. Far from being exhaustive, our analysis will focus upon the problems arising from the lack of equivalence at the word level. Consequently, relevant examples from the economic field will be provided to account for the following types of non-equivalence at word level: culturespecific concepts; the source language concept is not lexicalised in the target language; the source language word is semantically complex; differences in physical and interpersonal perspective; differences in expressive meaning; differences in form; differences in frequency and purpose of using specific forms and the use of loan words in the source text. Likewise, we shall illustrate a number of translation strategies necessary to deal with the afore-mentioned cases of non-equivalence: translation by a more general word (superordinate; translation by a more neutral/less expressive word; translation by cultural substitution; translation using a loan word or loan word plus explanation; translation by paraphrase using a related word; translation by paraphrase using unrelated words; translation by omission and translation by illustration.

Radioactive waste equivalence

International Nuclear Information System (INIS)

Orlowski, S.; Schaller, K.H.

1990-01-01

The report reviews, for the Member States of the European Community, possible situations in which an equivalence concept for radioactive waste may be used, analyses the various factors involved, and suggests guidelines for the implementation of such a concept. Only safety and technical aspects are covered. Other aspects such as commercial ones are excluded. Situations where the need for an equivalence concept has been identified are processes where impurities are added as a consequence of the treatment and conditioning process, the substitution of wastes from similar waste streams due to the treatment process, and exchange of waste belonging to different waste categories. The analysis of factors involved and possible ways for equivalence evaluation, taking into account in particular the chemical, physical and radiological characteristics of the waste package, and the potential risks of the waste form, shows that no simple all-encompassing equivalence formula may be derived. Consequently, a step-by-step approach is suggested, which avoids complex evaluations in the case of simple exchanges

Equivalence principles and electromagnetism

Science.gov (United States)

Ni, W.-T.

1977-01-01

The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

Are encapsulated anterior glass-ionomer restoratives better than their hand-mixed equivalents?

LENUS (Irish Health Repository)

Dowling, Adam H

2009-02-01

The performance of encapsulated anterior GI restoratives were compared with their hand-mixed equivalents for the range of powder to liquid mixing ratios routinely encountered clinically. The clinically induced variability of powder to liquid mixing variations of an anhydrous GI restorative formulation was also compared with conventional GI restorative formulations that contained a polyalkenoic acidic liquid.

New recommendations for dose equivalent

International Nuclear Information System (INIS)

Bengtsson, G.

1985-01-01

In its report 39, the International Commission on Radiation Units and Measurements (ICRU), has defined four new quantities for the determination of dose equivalents from external sources: the ambient dose equivalent, the directional dose equivalent, the individual dose equivalent, penetrating and the individual dose equivalent, superficial. The rationale behind these concepts and their practical application are discussed. Reference is made to numerical values of these quantities which will be the subject of a coming publication from the International Commission on Radiological Protection, ICRP. (Author)

Equivalent models of wind farms by using aggregated wind turbines and equivalent winds

International Nuclear Information System (INIS)

Fernandez, L.M.; Garcia, C.A.; Saenz, J.R.; Jurado, F.

2009-01-01

As a result of the increasing wind farms penetration on power systems, the wind farms begin to influence power system, and therefore the modeling of wind farms has become an interesting research topic. In this paper, new equivalent models of wind farms equipped with wind turbines based on squirrel-cage induction generators and doubly-fed induction generators are proposed to represent the collective behavior on large power systems simulations, instead of using a complete model of wind farms where all the wind turbines are modeled. The models proposed here are based on aggregating wind turbines into an equivalent wind turbine which receives an equivalent wind of the ones incident on the aggregated wind turbines. The equivalent wind turbine presents re-scaled power capacity and the same complete model as the individual wind turbines, which supposes the main feature of the present equivalent models. Two equivalent winds are evaluated in this work: (1) the average wind from the ones incident on the aggregated wind turbines with similar winds, and (2) an equivalent incoming wind derived from the power curve and the wind incident on each wind turbine. The effectiveness of the equivalent models to represent the collective response of the wind farm at the point of common coupling to grid is demonstrated by comparison with the wind farm response obtained from the detailed model during power system dynamic simulations, such as wind fluctuations and a grid disturbance. The present models can be used for grid integration studies of large power system with an important reduction of the model order and the computation time

substantiation of the standards for tritium amino acids intake by human organism

International Nuclear Information System (INIS)

Zhesko, T.V.; Balonov, M.I.

1984-01-01

Calculated values of β-irradiation tissue doses of bound tritium and tritium oxide absorbed by animals treated with different amino acids are given. The obtained dose values are compared with tritium water doses. The data obtained in animal studies are extrapolated to man in order to determine the dose equivalent to the incorporated 3 H-amino acids dose. It is assumed that the dose equivalent to 3 H-amino acids radiation is three times as high as the equivalent amount of tritium oxide. 9 mCi/yr is established as the maximum allowable blood intake of 3 H-amino acids. Due to their metabolic characteristics, air permissible concentrations of 3 H-amino acids and tritium oxide have approximately the same values. The value of 30 nCi/cm 2 is recommended as a standard for work clothing contamination with 3 H-amino acids

[Teichoic acids from lactic acid bacteria].

Science.gov (United States)

Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

2012-01-01

The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

Key discoveries in bile acid chemistry and biology and their clinical applications: history of the last eight decades

Science.gov (United States)

Hofmann, Alan F.; Hagey, Lee R.

2014-01-01

During the last 80 years there have been extraordinary advances in our knowledge of the chemistry and biology of bile acids. We present here a brief history of the major achievements as we perceive them. Bernal, a physicist, determined the X-ray structure of cholesterol crystals, and his data together with the vast chemical studies of Wieland and Windaus enabled the correct structure of the steroid nucleus to be deduced. Today, C24 and C27 bile acids together with C27 bile alcohols constitute most of the bile acid “family”. Patterns of bile acid hydroxylation and conjugation are summarized. Bile acid measurement encompasses the techniques of GC, HPLC, and MS, as well as enzymatic, bioluminescent, and competitive binding methods. The enterohepatic circulation of bile acids results from vectorial transport of bile acids by the ileal enterocyte and hepatocyte; the key transporters have been cloned. Bile acids are amphipathic, self-associate in solution, and form mixed micelles with polar lipids, phosphatidylcholine in bile, and fatty acids in intestinal content during triglyceride digestion. The rise and decline of dissolution of cholesterol gallstones by the ingestion of 3,7-dihydroxy bile acids is chronicled. Scientists from throughout the world have contributed to these achievements. PMID:24838141

Evaluation of the efficacy of four weak acids as antifungal preservatives in low-acid intermediate moisture model food systems.

Science.gov (United States)

Huang, Yang; Wilson, Mark; Chapman, Belinda; Hocking, Ailsa D

2010-02-01

The potential efficacy of four weak acids as preservatives in low-acid intermediate moisture foods was assessed using a glycerol based agar medium. The minimum inhibitory concentrations (MIC, % wt./wt.) of each acid was determined at two pH values (pH 5.0, pH 6.0) and two a(w) values (0.85, 0.90) for five food spoilage fungi, Eurotium herbariorum, Eurotium rubrum, Aspergillus niger, Aspergillus flavus and Penicillium roqueforti. Sorbic acid, a preservative commonly used to control fungal growth in low-acid intermediate moisture foods, was included as a reference. The MIC values of the four acids were lower at pH 5.0 than pH 6.0 at equivalent a(w) values, and lower at 0.85 a(w) than 0.90 a(w) at equivalent pH values. By comparison with the MIC values of sorbic acid, those of caprylic acid and dehydroacetic acid were generally lower, whereas those for caproic acid were generally higher. No general observation could be made in the case of capric acid. The antifungal activities of all five weak acids appeared related not only to the undissociated form, but also the dissociated form, of each acid.

Self-assembled structures and pKa value of oleic acid in systems of biological relevance.

Science.gov (United States)

Salentinig, Stefan; Sagalowicz, Laurent; Glatter, Otto

2010-07-20

In the human digestion process, triglycerides are hydrolyzed by lipases to monoglycerides and the corresponding fatty acids. Here we report the self-assembly of structures in biologically relevant, emulsified oleic acid-monoolein mixtures at various pH values and oleic acid concentrations. Small-angle X-ray scattering, cryogenic transmission electron microscopy, and dynamic light scattering were used to investigate the structures formed, and to follow their transitions while these factors were varied. The addition of oleic acid to monoolein-based cubosomes was found to increase the critical packing parameter in the system. Structural transitions from bicontinuous cubosomes through hexosomes and micellar cubosomes (Fd3m symmetry) to emulsified microemulsions occur with increasing oleic acid concentration. At sufficiently high oleic acid concentration, the internal particle structure was also found to strongly depend on the pH of the aqueous phase: transformations from emulsified microemulsion through micellar cubosomes, hexosomes, and bicontinuous cubosomes to vesicles can be observed as a function of increasing pH. The reversible transition from liquid crystals to vesicles occurs at intestinal pH values (between pH 7 and 8). The hydrodynamic radius of the particles decreases from around 120 nm for internally structured particles to around 60 nm for vesicles. All transitions with pH are reversible. Finally, the apparent pK(a) for oleic acid in monoolein could be determined from the change of structure with pH. This value is within the physiological pH range of the intestine and depends somewhat on composition.

Synthesis and Characterization of Rhodamine B-ethylenediamine-hyaluronan Acid as Potential Biological Functional Materials

Science.gov (United States)

Li, Y. L.; Wang, W. X.; Wang, Y.; Zhang, W. B.; Gong, H. M.; Liu, M. X.

2018-05-01

The purpose of this study is to synthesize and characterize fluorescent polymers, rhodamine B-ethylenediamine-hyaluronan acid (RhB-EA-HA). RhB-EA-HA was successfully synthesized by ester ammonolysis reaction and amidation reaction. Moreover, the structural properties of RhB-EA-HA were characterized by 1H-NMR spectra, UV-vis spectrometry and Fourier transform infrared spectroscopy (FT-IR). RhB-EA-HA can be grafted on the surface of silica nanomaterials, which may be potential biological functional materials for drug delivery system.

Antineurodegenerative effect of phenolic extracts and caffeic acid derivatives in romaine lettuce on neuron-like PC-12 cells.

Science.gov (United States)

Im, Sung-Eun; Yoon, Hyungeun; Nam, Tae-Gyu; Heo, Ho Jin; Lee, Chang Yong; Kim, Dae-Ok

2010-08-01

In recent decades, romaine lettuce has been one of the fastest growing vegetables with respect to its consumption and production. An understanding is needed of the effect of major phenolic phytochemicals from romaine lettuce on biological protection for neuron-like PC-12 cells. Phenolics in fresh romaine lettuce were extracted, and then its total phenolics and total antioxidant capacity were measured spectrophotometrically. Neuroprotective effects of phenolic extract of romaine lettuce and its pure caffeic acid derivatives (caffeic, chicoric, chlorogenic, and isochlorogenic acids) in PC-12 cells were evaluated using two different in vitro methods: lactate dehydrogenase release and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assays. Total phenolics and total antioxidant capacity of 100 g of fresh romaine lettuce averaged 22.7 mg of gallic acid equivalents and 31.0 mg of vitamin C equivalents, respectively. The phenolic extract of romaine lettuce protected PC-12 cells against oxidative stress caused by H(2)O(2) in a dose-dependent manner. Isochlorogenic acid, one of the phenolics in romaine lettuce, showed stronger neuroprotection than the other three caffeic acid derivatives also found in the lettuce. Although romaine lettuce had lower levels of phenolics and antioxidant capacity compared to other common vegetables, its contribution to total antioxidant capacity and antineurodegenerative effect in human diets would be higher because of higher amounts of its daily per capita consumption compared to other common vegetables.

[The isozymes of stearil-coenzymeA-desaturase and insulin activity in the light of phylogenetic theory of pathology. Oleic fatty acid and realization of biologic functions of trophology and locomotion].

Science.gov (United States)

2013-11-01

The formation of function of isozymes of stearil-coenzymeA-desaturases occured at the different stages of phylogeny under realization of biologic function of trophology (stearil-coenzymeA-desaturase 1) and biologic function of locomotion, insulin system (stearil-coenzymeA-desaturase 2) billions years later. The stearil-coenzymeA-desaturase 1 transforms in C 18:1 oleic fatty acid only exogenous C 16:0 palmitinic saturated fatty acid. The stearil-coenzymeA-desaturase 2 transforms only endogenic palmitinic saturated fatty acid, synthesized form glucose. The biologic role of insulin is in energy support of biologic function of locomotion. Insulin through expressing stearil-coenzymeA-desaturase 2 transforms energetically non-optimal palmitinic variation of metabolism of substrates into highly effective oleic variation for cells' groundwork of energy (saturated fatty acid and mono fatty acid). The surplus of palmitinic saturated fatty acid in food is enabled in pathogenesis of resistance to insulin and derangement of synthesis of hormone by beta-cells of islets. The resistance to insulin and diabetes mellitus are primarily the derangement of metabolism of saturated fatty acids with mono fatty acids, energy problems of organism and only afterwards the derangement of metabolism of carbohydrates. It is desirable to restrict food intake of exogenous palmitinic saturated fatty acid. The reasons are low expression of independent of insulin stearil-coenzymeA-desaturase 2, marked lipotoxicity of polar form of palmitinic saturated fatty acid and synthesis of non-optimal palmitinic triglycerides instead of physiologic and more energetically more effective oleic triglycerides.

Correspondences. Equivalence relations

International Nuclear Information System (INIS)

Bouligand, G.M.

1978-03-01

We comment on sections paragraph 3 'Correspondences' and paragraph 6 'Equivalence Relations' in chapter II of 'Elements de mathematique' by N. Bourbaki in order to simplify their comprehension. Paragraph 3 exposes the ideas of a graph, correspondence and map or of function, and their composition laws. We draw attention to the following points: 1) Adopting the convention of writting from left to right, the composition law for two correspondences (A,F,B), (U,G,V) of graphs F, G is written in full generality (A,F,B)o(U,G,V) = (A,FoG,V). It is not therefore assumed that the co-domain B of the first correspondence is identical to the domain U of the second (EII.13 D.7), (1970). 2) The axiom of choice consists of creating the Hilbert terms from the only relations admitting a graph. 3) The statement of the existence theorem of a function h such that f = goh, where f and g are two given maps having the same domain (of definition), is completed if h is more precisely an injection. Paragraph 6 considers the generalisation of equality: First, by 'the equivalence relation associated with a map f of a set E identical to (x is a member of the set E and y is a member of the set E and x:f = y:f). Consequently, every relation R(x,y) which is equivalent to this is an equivalence relation in E (symmetrical, transitive, reflexive); then R admits a graph included in E x E, etc. Secondly, by means of the Hilbert term of a relation R submitted to the equivalence. In this last case, if R(x,y) is separately collectivizing in x and y, theta(x) is not the class of objects equivalent to x for R (EII.47.9), (1970). The interest of bringing together these two subjects, apart from this logical order, resides also in the fact that the theorem mentioned in 3) can be expressed by means of the equivalence relations associated with the functions f and g. The solutions of the examples proposed reveal their simplicity [fr

An engineered bacterium auxotrophic for an unnatural amino acid: a novel biological containment system

Directory of Open Access Journals (Sweden)

Yusuke Kato

2015-09-01

Full Text Available Biological containment is a genetic technique that programs dangerous organisms to grow only in the laboratory and to die in the natural environment. Auxotrophy for a substance not found in the natural environment is an ideal biological containment. Here, we constructed an Escherichia coli strain that cannot survive in the absence of the unnatural amino acid 3-iodo-L-tyrosine. This synthetic auxotrophy was achieved by conditional production of the antidote protein against the highly toxic enzyme colicin E3. An amber stop codon was inserted in the antidote gene. The translation of the antidote mRNA was controlled by a translational switch using amber-specific 3-iodo-L-tyrosine incorporation. The antidote is synthesized only when 3-iodo-L-tyrosine is present in the culture medium. The viability of this strain rapidly decreased with less than a 1 h half-life after removal of 3-iodo-L-tyrosine, suggesting that the decay of the antidote causes the host killing by activated colicin E3 in the absence of this unnatural amino acid. The contained strain grew 1.5 times more slowly than the parent strains. The escaper frequency was estimated to be 1.4 mutations (95% highest posterior density 1.1–1.8 per 105 cell divisions. This containment system can be constructed by only plasmid introduction without genome editing, suggesting that this system may be applicable to other microbes carrying toxin-antidote systems similar to that of colicin E3.

Calculation methods for determining dose equivalent

International Nuclear Information System (INIS)

Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

1987-11-01

A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. Critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 [1] methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed. The effective dose equivalent determined using ICRP-26 methods is significantly smaller than the dose equivalent determined by traditional methods. No existing personnel dosimeter or health physics instrument can determine effective dose equivalent. At the present time, the conversion of dosimeter response to dose equivalent is based on calculations for maximal or ''cap'' values using homogeneous spherical or cylindrical phantoms. The evaluated dose equivalent is, therefore, a poor approximation of the effective dose equivalent as defined by ICRP Publication 26. 3 refs., 2 figs., 1 tab

Effective dose equivalent

International Nuclear Information System (INIS)

Huyskens, C.J.; Passchier, W.F.

1988-01-01

The effective dose equivalent is a quantity which is used in the daily practice of radiation protection as well as in the radiation hygienic rules as measure for the health risks. In this contribution it is worked out upon which assumptions this quantity is based and in which cases the effective dose equivalent can be used more or less well. (H.W.)

Radiological equivalent of chemical pollutants

International Nuclear Information System (INIS)

Medina, V.O.

1982-01-01

The development of the peaceful uses of nuclear energy has caused continued effort toward public safety through radiation health protection measures and nuclear management practices. However, concern has not been focused on the development specifically in the operation of chemical pestrochemical industries as well as other industrial processes brought about by technological advancements. This article presents the comparison of the risk of radiation and chemicals. The methods used for comparing the risks of late effects of radiation and chemicals are considered at three levels. (a) as a frame of reference to give an impression of resolving power of biological tests; (b) as methods to quantify risks; (c) as instruments for an epidemiological survey of human populations. There are marked dissimilarities between chemicals and radiation and efforts to interpret chemical activity may not be achieved. Applicability of the concept of rad equivalence has many restrictions and as pointed out this approach is not an established one. (RTD)

Bone marrow equivalent prompt dose from two common fallout scenarios

International Nuclear Information System (INIS)

Morris, M.D.; Jones, T.D.; Young, R.W.

1994-01-01

A cell-kinetics model for radiation-induced myelopoiesis has been derived for mice, rats, dogs, sheep, swine, and burros. The model was extended to humans after extensive comparisons with molecular and cellular data from biological experiments and an assortment of predictive/validation tests on animal mortality, cell survival, and cellular repopulation following irradiations. One advantage of the model is that any complex pattern of protracted irradiation can be equated to its equivalent prompt dose. Severity of biological response depends upon target-organ dose, dose rate, and dose fractionation. Epidemiological and animal data are best suited for exposures given in brief periods of time. To use those data to assess risk from protracted human exposures, it is obligatory to model molecular repair and compensatory proliferation in terms of prompt dose. Although the model is somewhat complex both mathematically and biologically, this note describes simple numerical approximations for two common exposure scenarios. Both approximations are easily evaluated on a simple pocket calculator by a health physicist or emergency management officer. 12 refs., 5 figs

Antipsychotic dose equivalents and dose-years: a standardized method for comparing exposure to different drugs.

Science.gov (United States)

Andreasen, Nancy C; Pressler, Marcus; Nopoulos, Peg; Miller, Del; Ho, Beng-Choon

2010-02-01

A standardized quantitative method for comparing dosages of different drugs is a useful tool for designing clinical trials and for examining the effects of long-term medication side effects such as tardive dyskinesia. Such a method requires establishing dose equivalents. An expert consensus group has published charts of equivalent doses for various antipsychotic medications for first- and second-generation medications. These charts were used in this study. Regression was used to compare each drug in the experts' charts to chlorpromazine and haloperidol and to create formulas for each relationship. The formulas were solved for chlorpromazine 100 mg and haloperidol 2 mg to derive new chlorpromazine and haloperidol equivalents. The formulas were incorporated into our definition of dose-years such that 100 mg/day of chlorpromazine equivalent or 2 mg/day of haloperidol equivalent taken for 1 year is equal to one dose-year. All comparisons to chlorpromazine and haloperidol were highly linear with R(2) values greater than .9. A power transformation further improved linearity. By deriving a unique formula that converts doses to chlorpromazine or haloperidol equivalents, we can compare otherwise dissimilar drugs. These equivalents can be multiplied by the time an individual has been on a given dose to derive a cumulative value measured in dose-years in the form of (chlorpromazine equivalent in mg) x (time on dose measured in years). After each dose has been converted to dose-years, the results can be summed to provide a cumulative quantitative measure of lifetime exposure. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Equivalence relations of AF-algebra extensions

Indian Academy of Sciences (India)

In this paper, we consider equivalence relations of *-algebra extensions and describe the relationship between the isomorphism equivalence and the unitary equivalence. We also show that a certain group homomorphism is the obstruction for these equivalence relations to be the same.

Equivalent physical models and formulation of equivalent source layer in high-resolution EEG imaging

International Nuclear Information System (INIS)

Yao Dezhong; He Bin

2003-01-01

In high-resolution EEG imaging, both equivalent dipole layer (EDL) and equivalent charge layer (ECL) assumed to be located just above the cortical surface have been proposed as high-resolution imaging modalities or as intermediate steps to estimate the epicortical potential. Presented here are the equivalent physical models of these two equivalent source layers (ESL) which show that the strength of EDL is proportional to the surface potential of the layer when the outside of the layer is filled with an insulator, and that the strength of ECL is the normal current of the layer when the outside is filled with a perfect conductor. Based on these equivalent physical models, closed solutions of ECL and EDL corresponding to a dipole enclosed by a spherical layer are given. These results provide the theoretical basis of ESL applications in high-resolution EEG mapping

Equivalent physical models and formulation of equivalent source layer in high-resolution EEG imaging

Energy Technology Data Exchange (ETDEWEB)

Yao Dezhong [School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu City, 610054, Sichuan Province (China); He Bin [The University of Illinois at Chicago, IL (United States)

2003-11-07

In high-resolution EEG imaging, both equivalent dipole layer (EDL) and equivalent charge layer (ECL) assumed to be located just above the cortical surface have been proposed as high-resolution imaging modalities or as intermediate steps to estimate the epicortical potential. Presented here are the equivalent physical models of these two equivalent source layers (ESL) which show that the strength of EDL is proportional to the surface potential of the layer when the outside of the layer is filled with an insulator, and that the strength of ECL is the normal current of the layer when the outside is filled with a perfect conductor. Based on these equivalent physical models, closed solutions of ECL and EDL corresponding to a dipole enclosed by a spherical layer are given. These results provide the theoretical basis of ESL applications in high-resolution EEG mapping.

SU-F-T-124: Radiation Biological Equivalent Presentations OfLEM-1 and MKM Approaches in the Carbon-Ion Radiotherapy

International Nuclear Information System (INIS)

Hsi, W; Jiang, G; Sheng, Y

2016-01-01

Purpose: To study the correlations of the radiation biological equivalent doses (BED) along depth and lateral distance between LEM-1 and MKM approaches. Methods: In NIRS-MKM (Microdosimetric Kinetic Model) approach, the prescribed BED, referred as C-Eq, doses aims to present the relative biological effectiveness (RBE) for different energies of carbon-ions on a fixed 10% survival value of HCG cell with respect to convention X-ray. Instead of a fixed 10% survival, the BED doses of LEM-1 (Local Effect Model) approach, referred as X-Eq, aims to present the RBE over the whole survival curve of chordoma-like cell with alpha/beta ratio of 2.0. The relationship of physical doses as a function of C-Eq and X-Eq doses were investigated along depth and lateral distance for various sizes of cubic targets in water irradiated by carbon-ions. Results: At the center of each cubic target, the trends between physical and C-Eq or X-Eq doses can be described by a linear and 2nd order polynomial functions, respectively. Using fit functions can then calculate a scaling factor between C-Eq and X-Eq doses to have similar physical doses. With equalized C-Eq and X-Eq doses at the depth of target center, over- and under-estimated X-Eq to C-Eq are seen for depths before and after the target center, respectively. Near the distal edge along depth, sharp rising of RBE value is observed for X-Eq, but sharp dropping of RBE value is observed for C-Eq. For lateral locations near and just outside 50% dose level, sharp raising of RBE value is also seen for X-Eq, while only minor increasing with fast dropping for C-Eq. Conclusion: An analytical function to model the differences between the CEq and X-Eq doses along depth and lateral distance need to further investigated to explain varied clinic outcome of specific cancers using two different approaches to calculated BED doses.

[The hyperiricosuria as an indicator of derangement of biologic functions of endoecology and adaptation, biologic reactions of excretion, inflammation and arterial tension].

Science.gov (United States)

Titov, V N; Oshchepkova, E V; Dmitriev, V A; Gushchina, O V; Shiriaeva, Iu K; Iashin, A Ia

2012-04-01

During millions years in all animals allantoine (oxidized by uricase uric acid) was catabolite of purines and ascorbic acid was an acceptor of active forms of oxygen. The proximal tubules of nephron reabsorbed the trace amounts of uric acid Then during phylogenesis the primates had a mutation of ascorbic acid gen minus. Later on occurred a second spontaneous mutation and uricase gen minus and uric acid became catabolites of purines. In absence of ascorbic acid synthesis ions of urates became a major capturers of active forms of oxygen and all uric acid as before underwent the reabsorption. Later the carriers were formed which began in epithelium of proximal tubules to secrete all uric acid into urine. At every incident of "littering" of intercellular medium with endogenic flogogens (impairment of biologic function of endoecology) under compensatory development of biologic reaction of inflammation the need in inactivation of active forms of oxygen increases. Hence later on in phylogenesis one more stage was formed--post secretory reabsorption of uric acid In the biologic reaction of inflammation epithelium of proximal tubules initiates retentional hyperiricosuria. The general antioxidant activity of human blood plasma in 60% is presented by urates' ions. The excretion of uric acid includes 4 stages: filtration, full reabsorption, secretion and post secretory reabsorption. In phylogenesis these stages formed in sequence. The mild hyperiricosuria is most frequently considered as a non-specific indicator of activation of biologic reaction of inflammation. The productive hyperiricosuria develops more infrequently under surplus of meat food and cytolysis syndrome (intensification of cell loss in vivo). Under concentration of uric acid more than 400 mkmol/l part of urates circulates in intercellular medium in the form of crystals. The microcrystals of uric acid (biologic "litter") initiate the syndrome of systemic inflammatory response as an endogenic flogogen

Testing statistical hypotheses of equivalence

CERN Document Server

Wellek, Stefan

2010-01-01

Equivalence testing has grown significantly in importance over the last two decades, especially as its relevance to a variety of applications has become understood. Yet published work on the general methodology remains scattered in specialists' journals, and for the most part, it focuses on the relatively narrow topic of bioequivalence assessment.With a far broader perspective, Testing Statistical Hypotheses of Equivalence provides the first comprehensive treatment of statistical equivalence testing. The author addresses a spectrum of specific, two-sided equivalence testing problems, from the

Information Leakage from Logically Equivalent Frames

Science.gov (United States)

Sher, Shlomi; McKenzie, Craig R. M.

2006-01-01

Framing effects are said to occur when equivalent frames lead to different choices. However, the equivalence in question has been incompletely conceptualized. In a new normative analysis of framing effects, we complete the conceptualization by introducing the notion of information equivalence. Information equivalence obtains when no…

21 CFR 26.9 - Equivalence determination.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Equivalence determination. 26.9 Section 26.9 Food... Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.9 Equivalence determination... document insufficient evidence of equivalence, lack of opportunity to assess equivalence or a determination...

Use of the Concept of Equivalent Biologically Effective Dose (BED) to Quantify the Contribution of Hyperthermia to Local Tumor Control in Radiohyperthermia Cervical Cancer Trials, and Comparison With Radiochemotherapy Results

International Nuclear Information System (INIS)

Plataniotis, George A.; Dale, Roger G.

2009-01-01

Purpose: To express the magnitude of contribution of hyperthermia to local tumor control in radiohyperthermia (RT/HT) cervical cancer trials, in terms of the radiation-equivalent biologically effective dose (BED) and to explore the potential of the combined modalities in the treatment of this neoplasm. Materials and Methods: Local control rates of both arms of each study (RT vs. RT+HT) reported from randomized controlled trials (RCT) on concurrent RT/HT for cervical cancer were reviewed. By comparing the two tumor control probabilities (TCPs) from each study, we calculated the HT-related log cell-kill and then expressed it in terms of the number of 2 Gy fraction equivalents, for a range of tumor volumes and radiosensitivities. We have compared the contribution of each modality and made some exploratory calculations on the TCPs that might be expected from a combined trimodality treatment (RT+CT+HT). Results: The HT-equivalent number of 2-Gy fractions ranges from 0.6 to 4.8 depending on radiosensitivity. Opportunities for clinically detectable improvement by the addition of HT are only available in tumors with an alpha value in the approximate range of 0.22-0.28 Gy -1 . A combined treatment (RT+CT+HT) is not expected to improve prognosis in radioresistant tumors. Conclusion: The most significant improvements in TCP, which may result from the combination of RT/CT/HT for locally advanced cervical carcinomas, are likely to be limited only to those patients with tumors of relatively low-intermediate radiosensitivity.

Editorial: New operational dose equivalent quantities

International Nuclear Information System (INIS)

Harvey, J.R.

1985-01-01

The ICRU Report 39 entitled ''Determination of Dose Equivalents Resulting from External Radiation Sources'' is briefly discussed. Four new operational dose equivalent quantities have been recommended in ICRU 39. The 'ambient dose equivalent' and the 'directional dose equivalent' are applicable to environmental monitoring and the 'individual dose equivalent, penetrating' and the 'individual dose equivalent, superficial' are applicable to individual monitoring. The quantities should meet the needs of day-to-day operational practice, while being acceptable to those concerned with metrological precision, and at the same time be used to give effective control consistent with current perceptions of the risks associated with exposure to ionizing radiations. (U.K.)

Determination of trace elements in biological samples treated with formic acid by inductively coupled plasma mass spectrometry using a microconcentric nebulizer

International Nuclear Information System (INIS)

Tormen, Luciano; Gil, Raul A.; Frescura, Vera L.A.; Dante Martinez, Luis; Curtius, Adilson J.

2010-01-01

A simple and fast method for the determination of As, Ba, Cd, Co, Cu, Fe, Ga, Mn, Mo, Ni, Pb, Rb, Se, Sr, Tl, U, V and Zn in biological samples by inductively coupled plasma mass spectrometry (ICP-MS), after sample solubilization with formic acid and introduction by a microconcentric nebulizer, is proposed. The sample is mixed with formic acid, kept at 90 o C for one hour and then diluted with nitric acid aqueous solution to a 50% v/v formic acid and 1% v/v nitric acid final concentrations. The final sample solution flow rate for introduction into the plasma was 30 μL min -1 . The optimized and adopted nebulizer gas flow rate was 0.7 L min -1 and RF power was 800 W. These conditions are very different than those normally used when a conventional nebulizer is employed. Rodhium was used as internal standard. External calibration against aqueous standard solutions, without formic acid, could be used for quantification, except for As, Se and Zn. However, external calibration with 50% formic acid allows the determination of all analytes with high accuracy and it is recommended. The detection limits were between 0.0005 (Tl) and 0.22 mg kg -1 (Fe) and the precision expressed by the relative standard deviations (RSD) were between 0.2% (Sr) and 3.5% (Ga). Accuracy was validated by the analysis of four certified reference biological materials of animal tissues, comparing the results by linear regressions and by the t-test at a 95% confidence level. The recommended procedure avoids plasma instability and carbon deposit on the cones.

Biological radiation effects and radioprotection standards

International Nuclear Information System (INIS)

Clerc, H.

1991-03-01

In this report, after recalling the mode of action of ionizing radiations, the notions of dose, dose equivalents and the values of natural irradiation, the author describes the biological radiation effects. Then he presents the ICRP recommendations and their applications to the french radioprotection system

Mixed field dose equivalent measuring instruments

International Nuclear Information System (INIS)

Brackenbush, L.W.; McDonald, J.C.; Endres, G.W.R.; Quam, W.

1985-01-01

In the past, separate instruments have been used to monitor dose equivalent from neutrons and gamma rays. It has been demonstrated that it is now possible to measure simultaneously neutron and gamma dose with a single instrument, the tissue equivalent proportional counter (TEPC). With appropriate algorithms dose equivalent can also be determined from the TEPC. A simple ''pocket rem meter'' for measuring neutron dose equivalent has already been developed. Improved algorithms for determining dose equivalent for mixed fields are presented. (author)

Bovine cumulus-granulosa cells contain biologically active retinoid receptors that can respond to retinoic acid

Directory of Open Access Journals (Sweden)

Malayer Jerry

2003-11-01

Full Text Available Abstract Retinoids, a class of compounds that include retinol and its metabolite, retinoic acid, are absolutely essential for ovarian steroid production, oocyte maturation, and early embryogenesis. Previous studies have detected high concentrations of retinol in bovine large follicles. Further, administration of retinol in vivo and supplementation of retinoic acid during in vitro maturation results in enhanced embryonic development. In the present study, we hypothesized that retinoids administered either in vivo previously or in vitro can exert receptor-mediated effects in cumulus-granulosa cells. Total RNA extracted from in vitro cultured cumulus-granulosa cells was subjected to reverse transcription polymerase chain reaction (RT-PCR and mRNA expression for retinol binding protein (RBP, retinoic acid receptor alpha (RARalpha, retinoic acid receptor beta (RARbeta, retinoic acid receptor gamma (RARgamma, retinoid X receptor alpha (RXRalpha, retinoid X receptor beta (RXRbeta, retinaldehyde dehydrogenase-2 (RALDH-2, and peroxisome proliferator activated receptor gamma (PPARgamma. Transcripts were detected for RBP, RARalpha, RARgamma, RXRalpha, RXRbeta, RALDH-2, and PPARgamma. Expression of RARbeta was not detected in cumulus-granulosa cells. Using western blotting, immunoreactive RARalpha, and RXRbeta protein was also detected in bovine cumulus-granulosa cells. The biological activity of these endogenous retinoid receptors was tested using a transient reporter assay using the pAAV-MCS-betaRARE-Luc vector. Addition of 0.5 and 1 micro molar all-trans retinoic acid significantly (P trans retinol stimulated a mild increase in reporter activity, however, the increase was not statistically significant. Based on these results we conclude that cumulus cells contain endogenously active retinoid receptors and may also be competent to synthesize retinoic acid using the precursor, retinol. These results also indirectly provide evidence that retinoids

Characterization of revenue equivalence

NARCIS (Netherlands)

Heydenreich, B.; Müller, R.; Uetz, Marc Jochen; Vohra, R.

2009-01-01

The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called revenue equivalence. We give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The characterization holds

Sample size determination for a three-arm equivalence trial of Poisson and negative binomial responses.

Science.gov (United States)

Chang, Yu-Wei; Tsong, Yi; Zhao, Zhigen

2017-01-01

Assessing equivalence or similarity has drawn much attention recently as many drug products have lost or will lose their patents in the next few years, especially certain best-selling biologics. To claim equivalence between the test treatment and the reference treatment when assay sensitivity is well established from historical data, one has to demonstrate both superiority of the test treatment over placebo and equivalence between the test treatment and the reference treatment. Thus, there is urgency for practitioners to derive a practical way to calculate sample size for a three-arm equivalence trial. The primary endpoints of a clinical trial may not always be continuous, but may be discrete. In this paper, the authors derive power function and discuss sample size requirement for a three-arm equivalence trial with Poisson and negative binomial clinical endpoints. In addition, the authors examine the effect of the dispersion parameter on the power and the sample size by varying its coefficient from small to large. In extensive numerical studies, the authors demonstrate that required sample size heavily depends on the dispersion parameter. Therefore, misusing a Poisson model for negative binomial data may easily lose power up to 20%, depending on the value of the dispersion parameter.

Characterization of Revenue Equivalence

NARCIS (Netherlands)

Heydenreich, Birgit; Müller, Rudolf; Uetz, Marc Jochen; Vohra, Rakesh

2008-01-01

The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called \\emph{revenue equivalence}. In this paper we give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The

Equivalent Gene Expression Profiles between Glatopa™ and Copaxone®.

Directory of Open Access Journals (Sweden)

Josephine S D'Alessandro

Full Text Available Glatopa™ is a generic glatiramer acetate recently approved for the treatment of patients with relapsing forms of multiple sclerosis. Gene expression profiling was performed as a means to evaluate equivalence of Glatopa and Copaxone®. Microarray analysis containing 39,429 unique probes across the entire genome was performed in murine glatiramer acetate--responsive Th2-polarized T cells, a test system highly relevant to the biology of glatiramer acetate. A closely related but nonequivalent glatiramoid molecule was used as a control to establish assay sensitivity. Multiple probe-level (Student's t-test and sample-level (principal component analysis, multidimensional scaling, and hierarchical clustering statistical analyses were utilized to look for differences in gene expression induced by the test articles. The analyses were conducted across all genes measured, as well as across a subset of genes that were shown to be modulated by Copaxone. The following observations were made across multiple statistical analyses: the expression of numerous genes was significantly changed by treatment with Copaxone when compared against media-only control; gene expression profiles induced by Copaxone and Glatopa were not significantly different; and gene expression profiles induced by Copaxone and the nonequivalent glatiramoid were significantly different, underscoring the sensitivity of the test system and the multiple analysis methods. Comparative analysis was also performed on sets of transcripts relevant to T-cell biology and antigen presentation, among others that are known to be modulated by glatiramer acetate. No statistically significant differences were observed between Copaxone and Glatopa in the expression levels (magnitude and direction of these glatiramer acetate-regulated genes. In conclusion, multiple methods consistently supported equivalent gene expression profiles between Copaxone and Glatopa.

Quantification of the equivalence principle

International Nuclear Information System (INIS)

Epstein, K.J.

1978-01-01

Quantitative relationships illustrate Einstein's equivalence principle, relating it to Newton's ''fictitious'' forces arising from the use of noninertial frames, and to the form of the relativistic time dilatation in local Lorentz frames. The equivalence principle can be interpreted as the equivalence of general covariance to local Lorentz covariance, in a manner which is characteristic of Riemannian and pseudo-Riemannian geometries

Jasmonic and salicylic acids enhanced phytochemical production and biological activities in cell suspension cultures of spine gourd (Momordica dioica Roxb).

Science.gov (United States)

Chung, Ill-Min; Rekha, Kaliyaperumal; Rajakumar, Govindasamy; Thiruvengadam, Muthu

2017-03-01

In vitro cell suspension culture was established for the production of commercially valuable phytochemicals in Momordica dioica. The influence of elicitors in jasmonic acid (JA) and salicylic acid (SA) increased their effect on phytochemical production and biomass accumulation in M. dioica. The results indicate that compared with non-elicited cultures, JA- and SA-elicited cell suspension cultures had significantly enhanced phenolic, flavonoid, and carotenoid production, as well as antioxidant, antimicrobial, and antiproliferative activities. Furthermore, elicited cultures produced 22 phenolic compounds, such as flavonols, hydroxycinnamic acids, and hydroxybenzoic acids. Greater biomass production, phytochemical accumulation, and biological activity occurred in JA- than in SA-elicited cell cultures. This study is the first to successfully establish M. dioica cell suspension cultures for the production of phenolic compounds and carotenoids, as well as for biomass accumulation.

Biology and chemistry of tree Pennsylvania lakes: responses to acid precipitation. [Lepomis gibbosus; Lepomis machrochirous

Energy Technology Data Exchange (ETDEWEB)

Bradt, P.T.; Dudley, J.L.; Berg, M.B.; Barrasso, D.S.

1986-01-01

The biology and chemistry of three northeastern Pennsylvania lakes was studied from summer 1981 through summer 1983 to evaluate lakes with different sensitivities to acidification. At the acidifies lake (total alkalinity par. delta 0.0 ..mu..eq L/sup -1/) there were fewer phytoplankton and zooplankton species than at the moderately sensitive lakes. The most numerous plankton species in all three lakes are reportedly acid tolerant. Among the benthic macro- invertebrates (BMI) there were more acid tolerant Chironomidae at the acidified lake, but more acid intolerant Ephemeroptera and Mollusca and a higher wet weight at the least sensitive lake. There were no differences among the lakes' BMI mean total numbers or mean number of taxa. The fish community at the acidified lake was dominated by stunted Lepomis gibbosus, but L. machrochirous were most abundant in the other lakes. Principal component analysis suggested a shift in all three lakes over the sampling period toward combined lower pH, alkalinity, specific conductance, Ca, and Mg and higher Al and Mn. Such chemical changes have been associated with acidification. The rate and extent of acidification appeared to be controlled by geological and hydrological characteristics of the drainage basins.

Glycemia and insulinemia in healthy subjects after lactose-equivalent meals of milk and other food proteins

DEFF Research Database (Denmark)

Nilsson, Mikael; Stenberg, Marianne; Frid, Anders H

2004-01-01

, cheese, whey, cod, and wheat gluten with equivalent amounts of lactose. An equicarbohydrate load of white-wheat bread was used as a reference meal. RESULTS: A correlation was found between postprandial insulin responses and early increments in plasma amino acids; the strongest correlations were seen...

The principle of equivalence reconsidered: assessing the relevance of the principle of equivalence in prison medicine.

Science.gov (United States)

Jotterand, Fabrice; Wangmo, Tenzin

2014-01-01

In this article we critically examine the principle of equivalence of care in prison medicine. First, we provide an overview of how the principle of equivalence is utilized in various national and international guidelines on health care provision to prisoners. Second, we outline some of the problems associated with its applications, and argue that the principle of equivalence should go beyond equivalence to access and include equivalence of outcomes. However, because of the particular context of the prison environment, third, we contend that the concept of "health" in equivalence of health outcomes needs conceptual clarity; otherwise, it fails to provide a threshold for healthy states among inmates. We accomplish this by examining common understandings of the concepts of health and disease. We conclude our article by showing why the conceptualization of diseases as clinical problems provides a helpful approach in the delivery of health care in prison.

On the operator equivalents

International Nuclear Information System (INIS)

Grenet, G.; Kibler, M.

1978-06-01

A closed polynomial formula for the qth component of the diagonal operator equivalent of order k is derived in terms of angular momentum operators. The interest in various fields of molecular and solid state physics of using such a formula in connection with symmetry adapted operator equivalents is outlined

A limited LCA of bio-adipic acid: Manufacturing the nylon-6,6 precursor adipic acid using the benzoic acid degradation pathway from different feedstocks

NARCIS (Netherlands)

Duuren, van J.B.J.H.; Brehmer, B.; Mars, A.E.; Eggink, G.; Martins Dos Santos, V.A.P.; Sanders, J.P.M.

2011-01-01

A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics,

Headspace solid-phase microextraction with 1-pyrenyldiazomethane on-fibre derivatisation for analysis of fluoroacetic acid in biological samples.

Science.gov (United States)

Sporkert, Frank; Pragst, Fritz; Hübner, Sandra; Mills, Graham

2002-05-25

A new and in part automated headspace solid-phase microextraction method for quantitative determination of the highly toxic rodenticide fluoroacetic acid (FAA) in serum and other biological samples has been developed. FAA and deuterated acetic acid (internal standard) were extracted from acidified samples by a StableFlex divinylbenzene-Carboxen on polydimethylsiloxane fibre. The acids were derivatised on the fibre in-situ with 1-pyrenyldiazomethane and detected using gas chromatography-mass spectrometry with electron impact ionisation and selected ion monitoring. The calibration curve for FAA in serum was linear over the range from 0.02 to 5 microg/ml, with limits of detection and quantification of 0.02 and 0.07 microg/ml, respectively. The method was also tested with spiked whole blood, urine, stomach contents and kidney samples. It was sufficiently reliable, reproducible and sensitive for use in routine forensic toxicology applications.

78 FR 67360 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Five New Equivalent Methods

Science.gov (United States)

2013-11-12

... Methods: Designation of Five New Equivalent Methods AGENCY: Office of Research and Development; Environmental Protection Agency (EPA). ACTION: Notice of the designation of five new equivalent methods for...) has designated, in accordance with 40 CFR Part 53, five new equivalent methods, one for measuring...

77 FR 60985 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

Science.gov (United States)

2012-10-05

... Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of three new equivalent methods for monitoring ambient air quality. SUMMARY... equivalent methods, one for measuring concentrations of PM 2.5 , one for measuring concentrations of PM 10...

An algorithm to biological tissues evaluation in pediatric examinations

International Nuclear Information System (INIS)

Souza, R.T.F.; Miranda, J.R.A.; Alvarez, M.; Velo, A.F.; Pina, D.R.

2011-01-01

A prerequisite for the construction of phantoms is the quantification of the average thickness of biological tissues and the equivalence of these simulators in simulator material thicknesses. This study aim to develop an algorithm to classify and quantify tissues, based on normal distribution of CT numbers of anatomical structures found in the mean free path of the X-rays beam, using the examination histogram to carry out this evaluation. We have considered an algorithm for the determination of the equivalent biological tissues thickness from histograms. This algorithm classifies different biological tissues from tomographic exams in DICOM format and calculates the average thickness of these tissues. The founded results had revealed coherent with literature, presenting discrepancies of up to 21,6%, relative to bone tissue, analyzed for anthropomorphic phantom (RANDO). These results allow using this methodology in livings tissues, for the construction of thorax homogeneous phantoms, of just born and suckling patients, who will be used later in the optimization process of pediatrics radiographic images. (author)

Investigation of Equivalent Circuit for PEMFC Assessment

International Nuclear Information System (INIS)

Myong, Kwang Jae

2011-01-01

Chemical reactions occurring in a PEMFC are dominated by the physical conditions and interface properties, and the reactions are expressed in terms of impedance. The performance of a PEMFC can be simply diagnosed by examining the impedance because impedance characteristics can be expressed by an equivalent electrical circuit. In this study, the characteristics of a PEMFC are assessed using the AC impedance and various equivalent circuits such as a simple equivalent circuit, equivalent circuit with a CPE, equivalent circuit with two RCs, and equivalent circuit with two CPEs. It was found in this study that the characteristics of a PEMFC could be assessed using impedance and an equivalent circuit, and the accuracy was highest for an equivalent circuit with two CPEs

Topicality of identification of free fatty acids pattern in biologic substrates in the diagnosis of gastroenterological diseases

Directory of Open Access Journals (Sweden)

V.I. Didenko

2017-04-01

Full Text Available The article shows the role of free fatty acids in the pathogenesis of metabolic and gastroenterological disorders. An expediency of gas chromatography method for determination of free fatty acids pattern in biologic samples (blood serum, urine, feces and other was substantiated. The role of free fatty acids in the cell structure components formation, energetic homeostasis and signal molecules or their precursor production was shown. So, disorders of regulation of free fatty acids metabolism lead to systemic fails of insulin action, such as glucose metabolism in adipocytes, muscles and liver. Increase in several fractions of lipid pattern takes place in different pathologic states. These changes occur earlier than changes of enzymes activity or other protein markers. For example, short chain fatty acids can be used for identification of syndrome of bacterial overgrowth in the intestines. Increasе in polyunsaturated fatty acid fraction activates inflammation process, immune reactions, blood hypercoagulation, activation of lipid peroxidation. Also, arachidonic (C20:0, dodecanoic (C12:0 and linoleic (C18:3 acids are markers of inflammation processes. In addition, deficiency of free fatty acids is very important aspect of diagnois. It can’t be uncertified by standard laboratory methods. Proven fact is that essential fatty acids can be a cause of metabolic syndrome, non-alcoholic fatty liver disease formation such as other diseases associated with metabolism. So, only chromatography today is a method for determination fatty acid pattern. The advantages of gas chromatography are rapid realization and high accuracy. Thus, identification of trace concentrations (about 10–12 mole is possible. Implementation of this method into the clinical practice of gastroenterology specialists allows the early diagnosis of pathologies and choice of correct treatment.

Indole-3-acetic acid/diol based pH-sensitive biological macromolecule for antibacterial, antifungal and antioxidant applications.

Science.gov (United States)

G, Chitra; D S, Franklin; S, Sudarsan; M, Sakthivel; S, Guhanathan

2017-02-01

Indole-3-acetic acid (IAA)/diol based pH-sensitive biopolymeric hydrogels with tunable biological properties (cytotoxicity, anti-oxidant and anti-fungal) have been synthesized via condensation polymerization. The present study focused on the synthesis of heterocyclic hydrogel using citric acid (CA), indole-3-acetic acid (IAA) and diethylene glycol (DEG) by condensation polymerization. The hydrogels revealed a pH-sensitive swelling behaviour, with increased swelling in acidic media, then turns to decreased the swelling in the basic media. The hydrogel samples were tested for antifungal activity against Aspergillus fumigates, Rhizopusoryzae and Candida albicans at different concentrations using ketoconazole as positive control and DMSO as negative control for antifungal activity. Antioxidant activity increasing nature in DPPH than NO radical compared with rutin and confirmed non toxic property using cytotoxicity analysis. The biopolymeric hydrogels were characterized by Fourier transform infrared (FT-IR) spectroscopy, 1 H NMR, 13 C NMR, TGA, DSC followed by scanning electron microscopy (SEM). Such hydrogels with antioxidant properties is recommended for medical applications such as bandages, catheters, drains and tubes to prevent infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Systems biology of lactic acid bacteria: a critical review.

Science.gov (United States)

Teusink, Bas; Bachmann, Herwig; Molenaar, Douwe

2011-08-30

Understanding the properties of a system as emerging from the interaction of well described parts is the most important goal of Systems Biology. Although in the practice of Lactic Acid Bacteria (LAB) physiology we most often think of the parts as the proteins and metabolites, a wider interpretation of what a part is can be useful. For example, different strains or species can be the parts of a community, or we could study only the chemical reactions as the parts of metabolism (and forgetting about the enzymes that catalyze them), as is done in flux balance analysis. As long as we have some understanding of the properties of these parts, we can investigate whether their interaction leads to novel or unanticipated behaviour of the system that they constitute. There has been a tendency in the Systems Biology community to think that the collection and integration of data should continue ad infinitum, or that we will otherwise not be able to understand the systems that we study in their details. However, it may sometimes be useful to take a step back and consider whether the knowledge that we already have may not explain the system behaviour that we find so intriguing. Reasoning about systems can be difficult, and may require the application of mathematical techniques. The reward is sometimes the realization of unexpected conclusions, or in the worst case, that we still do not know enough details of the parts, or of the interactions between them. We will discuss a number of cases, with a focus on LAB-related work, where a typical systems approach has brought new knowledge or perspective, often counterintuitive, and clashing with conclusions from simpler approaches. Also novel types of testable hypotheses may be generated by the systems approach, which we will illustrate. Finally we will give an outlook on the fields of research where the systems approach may point the way for the near future.

Logically automorphically equivalent knowledge bases

OpenAIRE

Aladova, Elena; Plotkin, Tatjana

2017-01-01

Knowledge bases theory provide an important example of the field where applications of universal algebra and algebraic logic look very natural, and their interaction with practical problems arising in computer science might be very productive. In this paper we study the equivalence problem for knowledge bases. Our interest is to find out how the informational equivalence is related to the logical description of knowledge. Studying various equivalences of knowledge bases allows us to compare d...

[Regulating acid stress resistance of lactic acid bacteria--a review].

Science.gov (United States)

Wu, Chongde; Huang, Jun; Zhou, Rongqing

2014-07-04

As cell factories, lactic acid bacteria are widely used in food, agriculture, pharmaceutical and other industries. Acid stress is one the important survival challenges encountered by lactic acid bacteria both in fermentation process and in the gastrointestinal tract. Recently, the development of systems biology and metabolic engineering brings unprecedented opportunity for further elucidating the acid tolerance mechanisms and improving the acid stress resistance of lactic acid bacteria. This review addresses physiological mechanisms of lactic acid bacteria during acid stress. Moreover, strategies to improve the acid stress resistance of lactic acid were proposed.

Labeling of amino acid (L-Glutamine) with technetium-99m and biological evaluation

International Nuclear Information System (INIS)

Ahmed, S. S.; Abass, S. A. E.; Karim, L. M.; Risan, R. H.; Abdulkarim, H. M.; Zia, M. A.; Manjy, A.N.; Hamed, S. A.

2012-12-01

The study of labeling of some amino acid 9 9mT c has been carried before (1, 2). Some were found to be chemically valuable, while some others had no clinical value although, they provided US with knowledge on the mechanism of labeling and biodistribution. In this paper we experimented the possibility of labeling L-Glutamine with Tc 9 '9 m and studied its biological behavior the study revealed that the optimal pH for the formation of higher percentage of the complex is about (2.5-2.55). Biodistribution carried in balb/c mice showed that the complex accumulates in soft tissue of the abdomen. This fining may indicate good clinical value in diagnosis of soft tissue tumors of lesion. (Author)

Biological study of some labeled C16 fatty acids

Energy Technology Data Exchange (ETDEWEB)

Riche, F.; Mathieu, J.P.; Busquet, G.; Vidal, M.; Comet, M.; Pernin, C. (C.H.R.U. de Grenoble, 38 - La Tronche (France)); Godart, J.; Benabed, A. (Institut des Sciences Nucleaires, 38 - Grenoble (France)); Bardy, A. (C.E.A.-ORIS, 91 - Gif-sur-Yvette (France))

1983-01-01

The evolution of myocardial, blood, liver and kidney activity is studied in mice after I.V. injection of some labelled C16 fatty acids. With ..omega.. iodo fatty acids, the presence or absence of a double bond and the character Z or E have no influence on the tissue activity. The presence of a triple bond decreases the fixation, modifies the intramyocardial metabolism of the fatty acid and accelerates the rate of decrease of myocardial activity. ..omega.. bromo fatty acid have the same maximal fixation as ..omega.. iodo fatty acid but a more rapid decrease of myocardial activity. ..cap alpha.. iodo fatty acid has a very low myocardial fixation.

Biological study of some labeled C16 fatty acids

International Nuclear Information System (INIS)

Riche, F.; Mathieu, J.P.; Busquet, G.; Vidal, M.; Comet, M.; Pernin, C.; Godart, J.; Benabed, A.; Bardy, A.

1983-01-01

The evolution of myocardial, blood, liver and kidney activity is studied in mice after I.V. injection of some labelled C16 fatty acids. With ω iodo fatty acids, the presence or absence of a double bond and the character Z or E have no influence on the tissue activity. The presence of a triple bond decreases the fixation, modifies the intramyocardial metabolism of the fatty acid and accelerates the rate of decrease of myocardial activity. ω bromo fatty acid have the same maximal fixation as ω iodo fatty acid but a more rapid decrease of myocardial activity. α iodo fatty acid has a very low myocardial fixation [fr

Formation of biologically relevant carboxylic acids during the gamma irradiation of acetic acid

Science.gov (United States)

Negron-Mendoza, A.; Ponnamperuma, C.

1976-01-01

Irradiation of aqueous solutions of acetic acid with gamma rays produced several carboxylic acids in small yield. Their identification was based on the technique of gas chromatography combined with mass spectrometry. Some of these acids are Krebs Cycle intermediates. Their simultaneous formation in experiments simulating the primitive conditions on the earth suggests that metabolic pathways may have had their origin in prebiotic chemical processes.

Equivalent circuit parameters of nickel/metal hydride batteries from sparse impedance measurements

Science.gov (United States)

Nelatury, Sudarshan Rao; Singh, Pritpal

In a recent communication, a method for extracting the equivalent circuit parameters of a lead acid battery from sparse (only three) impedance spectroscopy observations at three different frequencies was proposed. It was based on an equivalent circuit consisting of a bulk resistance, a reaction resistance and a constant phase element (CPE). Such a circuit is a very appropriate model of a lead-acid cell at high state of charge (SOC). This paper is a sequel to it and presents an application of it in case of nickel/metal hydride (Ni/MH) batteries, which also at high SOC are represented by the same circuit configuration. But when the SOC of a Ni/MH battery under interrogation goes low, The EIS curve has a positive slope at the low frequency end and our technique yields complex values for the otherwise real circuit parameters, suggesting the need for additional elements in the equivalent circuit and a definite relationship between parameter consistency and SOC. To improvise the previous algorithm, in order that it works reasonably well at both high and low SOCs, we propose three more measurements—two at very low frequencies to include the Warburg response and one at a high frequency to model the series inductance, in addition to the three in the mid frequency band—totally six measurements. In most of the today's instrumentation, it is the user who should choose the circuit configuration and the number of frequencies where impedance should be measured and the accompanying software performs data fitting by complex nonlinear least squares. The proposed method has built into it an SOC-based decision-making capability—both to choose the circuit configuration and to estimate the values of the circuit elements.

46 CFR 175.540 - Equivalents.

Science.gov (United States)

2010-10-01

... Safety Management (ISM) Code (IMO Resolution A.741(18)) for the purpose of determining that an equivalent... Organization (IMO) “Code of Safety for High Speed Craft” as an equivalent to compliance with applicable...

Wijsman Orlicz Asymptotically Ideal -Statistical Equivalent Sequences

Directory of Open Access Journals (Sweden)

Bipan Hazarika

2013-01-01

in Wijsman sense and present some definitions which are the natural combination of the definition of asymptotic equivalence, statistical equivalent, -statistical equivalent sequences in Wijsman sense. Finally, we introduce the notion of Cesaro Orlicz asymptotically -equivalent sequences in Wijsman sense and establish their relationship with other classes.

The performance of low pressure tissue-equivalent chambers and a new method for parameterising the dose equivalent

International Nuclear Information System (INIS)

Eisen, Y.

1986-01-01

The performance of Rossi-type spherical tissue-equivalent chambers with equivalent diameters between 0.5 μm and 2 μm was tested experimentally using monoenergetic and polyenergetic neutron sources in the energy region of 10 keV to 14.5 MeV. In agreement with theoretical predictions both chambers failed to provide LET information at low neutron energies. A dose equivalent algorithm was derived that utilises the event distribution but does not attempt to correlate event size with LET. The algorithm was predicted theoretically and confirmed by experiment. The algorithm that was developed determines the neutron dose equivalent, from the data of the 0.5 μm chamber, to better than +-20% over the energy range of 30 keV to 14.5 MeV. The same algorithm also determines the dose equivalent from the data of the 2 μm chamber to better than +-20% over the energy range of 60 keV to 14.5 MeV. The efficiency of the chambers is 33 counts per μSv, or equivalently about 10 counts s -1 per mSv.h -1 . This efficiency enables the measurement of dose equivalent rates above 1 mSv.h -1 for an integration period of 3 s. Integrated dose equivalents can be measured as low as 1 μSv. (author)

Equivalence in Bilingual Lexicography: Criticism and Suggestions*

Directory of Open Access Journals (Sweden)

Herbert Ernst Wiegand

2011-10-01

Full Text Available

Abstract: A reminder of general problems in the formation of terminology, as illustrated by theGerman Äquivalence (Eng. equivalence and äquivalent (Eng. equivalent, is followed by a critical discussionof the concept of equivalence in contrastive lexicology. It is shown that especially the conceptof partial equivalence is contradictory in its different manifestations. Consequently attemptsare made to give a more precise indication of the concept of equivalence in the metalexicography,with regard to the domain of the nominal lexicon. The problems of especially the metalexicographicconcept of partial equivalence as well as that of divergence are fundamentally expounded.In conclusion the direction is indicated to find more appropriate metalexicographic versions of theconcept of equivalence.

Keywords: EQUIVALENCE, LEXICOGRAPHIC EQUIVALENT, PARTIAL EQUIVALENCE,CONGRUENCE, DIVERGENCE, CONVERGENCE, POLYDIVERGENCE, SYNTAGM-EQUIVALENCE,ZERO EQUIVALENCE, CORRESPONDENCE

Abstrakt: Äquivalenz in der zweisprachigen Lexikographie: Kritik und Vorschläge.Nachdem an allgemeine Probleme der Begriffsbildung am Beispiel von dt. Äquivalenzund dt. äquivalent erinnert wurde, wird zunächst auf Äquivalenzbegriffe in der kontrastiven Lexikologiekritisch eingegangen. Es wird gezeigt, dass insbesondere der Begriff der partiellen Äquivalenzin seinen verschiedenen Ausprägungen widersprüchlich ist. Sodann werden Präzisierungenzu den Äquivalenzbegriffen in der Metalexikographie versucht, die sich auf den Bereich der Nennlexikbeziehen. Insbesondere der metalexikographische Begriff der partiellen Äquivalenz sowie derder Divergenz werden grundsätzlich problematisiert. In welche Richtung man gehen kann, umangemessenere metalexikographische Fassungen des Äquivalenzbegriffs zu finden, wird abschließendangedeutet.

Stichwörter: ÄQUIVALENZ, LEXIKOGRAPHISCHES ÄQUIVALENT, PARTIELLE ÄQUIVALENZ,KONGRUENZ, DIVERGENZ, KONVERGENZ, POLYDIVERGENZ

Yeast prions: structure, biology, and prion-handling systems.

Science.gov (United States)

Wickner, Reed B; Shewmaker, Frank P; Bateman, David A; Edskes, Herman K; Gorkovskiy, Anton; Dayani, Yaron; Bezsonov, Evgeny E

2015-03-01

A prion is an infectious protein horizontally transmitting a disease or trait without a required nucleic acid. Yeast and fungal prions are nonchromosomal genes composed of protein, generally an altered form of a protein that catalyzes the same alteration of the protein. Yeast prions are thus transmitted both vertically (as genes composed of protein) and horizontally (as infectious proteins, or prions). Formation of amyloids (linear ordered β-sheet-rich protein aggregates with β-strands perpendicular to the long axis of the filament) underlies most yeast and fungal prions, and a single prion protein can have any of several distinct self-propagating amyloid forms with different biological properties (prion variants). Here we review the mechanism of faithful templating of protein conformation, the biological roles of these prions, and their interactions with cellular chaperones, the Btn2 and Cur1 aggregate-handling systems, and other cellular factors governing prion generation and propagation. Human amyloidoses include the PrP-based prion conditions and many other, more common amyloid-based diseases, several of which show prion-like features. Yeast prions increasingly are serving as models for the understanding and treatment of many mammalian amyloidoses. Patients with different clinical pictures of the same amyloidosis may be the equivalent of yeasts with different prion variants. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Pharmacokinetics of Caffeic Acid from Methanol Seed Extract of ...

African Journals Online (AJOL)

Methods: A dose of the extract (500 mg, equivalent to 37.135 mg caffeic acid) was administered orally to 6 male .... emission. Validation studies. Linearity. The rat plasma samples were spiked by caffeic acid solutions ..... Atomic structure of.

Some spectral equivalences between Schroedinger operators

International Nuclear Information System (INIS)

Dunning, C; Hibberd, K E; Links, J

2008-01-01

Spectral equivalences of the quasi-exactly solvable sectors of two classes of Schroedinger operators are established, using Gaudin-type Bethe ansatz equations. In some instances the results can be extended leading to full isospectrality. In this manner we obtain equivalences between PT-symmetric problems and Hermitian problems. We also find equivalences between some classes of Hermitian operators

Oral tranexamic acid is equivalent to topical tranexamic acid without drainage in primary total hip arthroplasty: A double-blind randomized clinical trial.

Science.gov (United States)

Luo, Ze-Yu; Wang, Duan; Meng, Wei-Kun; Wang, Hao-Yang; Pan, Hui; Pei, Fu-Xing; Zhou, Zong-Ke

2018-05-01

To compare the efficacy of multiple doses of oral tranexamic acid (TXA) with topical TXA administration in reducing blood loss following total hip arthroplasty (THA). In this double-blinded trial, 117 patients undergoing primary THA were randomized to receive 2 g TXA orally 2 h preoperatively, and two doses of 1 g TXA postoperatively (oral group) or 3 g of TXA topical administration in the operating room (topical group). The primary outcome was a reduction in hemoglobin concentration. Other outcomes-such as blood loss, TXA-related cost (¥), length of hospital stay (days), complications such as pulmonary thromboembolism (PE), deep vein thrombosis (DVT), and infection, blood coagulation and fibrinolysis, and hip function-were recorded. The mean reduction in hemoglobin level was similar between the oral and topical groups (3.07 g/dL compared with 3.12 g/dL; p = 0.85). Similarly, there was no significant difference in the mean total blood loss between oral and topical administration (863 mL compared with 902 mL; p = 0.62). Three patients received an allogeneic blood transfusion, including one patient in the oral group and two patients in the topical group (p = 0.55). The oral group had a significantly lower TXA-related cost than the topical group: ¥944 and ¥4359, respectively (p = 0.01). No PE, DVT, cardiac infarction or renal failure occurred during the 90-day follow-up. The coagulation and fibrinolysis parameters were similar between the two groups. Oral TXA is equivalent to topical TXA administration in the reduction of blood loss in the setting of primary THA without drainage. Copyright © 2018. Published by Elsevier Ltd.

Efficient and specific analysis of red blood cell glycerophospholipid fatty acid composition.

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Sabrina Klem

Full Text Available BACKGROUND: Red blood cell (RBC n-3 fatty acid status is related to various health outcomes. Accepted biological markers for the fatty acid status determination are RBC phospholipids, phosphatidylcholine, and phosphatidyletholamine. The analysis of these lipid fractions is demanding and time consuming and total phospholipid n-3 fatty acid levels might be affected by changes of sphingomyelin contents in the RBC membrane during n-3 supplementation. AIM: We developed a method for the specific analysis of RBC glycerophospholipids. The application of the new method in a DHA supplementation trial and the comparison to established markers will determine the relevance of RBC GPL as a valid fatty acid status marker in humans. METHODS: Methyl esters of glycerophospholipid fatty acids are selectively generated by a two step procedure involving methanolic protein precipitation and base-catalysed methyl ester synthesis. RBC GPL solubilisation is facilitated by ultrasound treatment. Fatty acid status in RBC glycerophospholipids and other established markers were evaluated in thirteen subjects participating in a 30 days supplementation trial (510 mg DHA/d. OUTCOME: The intra-assay CV for GPL fatty acids ranged from 1.0 to 10.5% and the inter-assay CV from 1.3 to 10.9%. Docosahexaenoic acid supplementation significantly increased the docosahexaenoic acid contents in all analysed lipid fractions. High correlations were observed for most of the mono- and polyunsaturated fatty acids, and for the omega-3 index (r = 0.924 between RBC phospholipids and glycerophospholipids. The analysis of RBC glycerophospholipid fatty acids yields faster, easier and less costly results equivalent to the conventional analysis of RBC total phospholipids.

Gauge equivalence of the Gross Pitaevskii equation and the equivalent Heisenberg spin chain

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Radha, R.; Kumar, V. Ramesh

2007-11-01

In this paper, we construct an equivalent spin chain for the Gross-Pitaevskii equation with quadratic potential and exponentially varying scattering lengths using gauge equivalence. We have then generated the soliton solutions for the spin components S3 and S-. We find that the spin solitons for S3 and S- can be compressed for exponentially growing eigenvalues while they broaden out for decaying eigenvalues.

Differential pulse polarographic determination of trace antimony in standard biological samples after preconcentration using 2-nitroso-1-naphthol-4-sulfonic acid

International Nuclear Information System (INIS)

Taher, M. A.

2003-01-01

A highly selective, rapid and economical differential polarographic method has been developed for the determination of trace amounts of antimony in various standard alloys and biological samples after of its 2-naphthol-4 sulfonic acid tetradecyl dimethylbenzylammonium chloride on microcrystalline naphthalene in the ph range of 7.5-11.0. After filtration, the solid mass is shaken with 8-10 ml of 1 M hydrochloric acid (with preconcentration factor of 10) and antimony is determined by differential pulse polarography. Antimony can alternatively be quantitatively absorbed on 2-nitroso-1-naphthol-4-sulfonic acid tetradecyl dimethylbenzylammonium-naphthalene absorbed packed in a column (with preconcentration factor of 30) and determined similarly. In this case, 1.5 μg of antimony can be concentrated in a column from 300 ml of aqueous sample, where its concentration is as low as 5 ng/ml. Characterization of the electro active process included an examination of the degree of reversibility. The results show that the irreversibility of antimony. Various parameters such as the effect of ph, volume of aqueous phase, HCl concentration, reagent concentration, naphthalene concentration, shaking time and interference of a number of metal ions on the determination of antimony have been studied in detail to optimize the conditions for determination in standard alloys and standard biological samples

Surface functionalization of bioactive glasses with natural molecules of biological significance, Part I: Gallic acid as model molecule

Science.gov (United States)

Zhang, Xin; Ferraris, Sara; Prenesti, Enrico; Verné, Enrica

2013-12-01

Gallic acid (3,4,5-trihydroxybenzoic acid, GA) and its derivatives are a group of biomolecules (polyphenols) obtained from plants. They have effects which are potentially beneficial to heath, for example they are antioxidant, anticarcinogenic and antibacterial, as recently investigated in many fields such as medicine, food and plant sciences. The main drawbacks of these molecules are both low stability and bioavailability. In this research work the opportunity to graft GA to bioactive glasses is investigated, in order to deliver the undamaged biological molecule into the body, using the biomaterial surfaces as a localized carrier. GA was considered for functionalization since it is a good model molecule for polyphenols and presents several interesting biological activities, like antibacterial, antioxidant and anticarcinogenic properties. Two different silica based bioactive glasses (SCNA and CEL2), with different reactivity, were employed as substrates. UV photometry combined with the Folin&Ciocalteu reagent was adopted to test the concentration of GA in uptake solution after functionalization. This test verified how much GA consumption occurred with surface modification and it was also used on solid samples to test the presence of GA on functionalized glasses. XPS and SEM-EDS techniques were employed to characterize the modification of material surface properties and functional group composition before and after functionalization.

Arthroscopic Double-Row Transosseous Equivalent Rotator Cuff Repair with a Knotless Self-Reinforcing Technique

OpenAIRE

Mook, William R.; Greenspoon, Joshua A.; Millett, Peter J.

2016-01-01

Background: Rotator cuff tears are a significant cause of shoulder morbidity. Surgical techniques for repair have evolved to optimize the biologic and mechanical variables critical to tendon healing. Double-row repairs have demonstrated superior biomechanical advantages to a single-row. Methods: The preferred technique for rotator cuff repair of the senior author was reviewed and described in a step by step fashion. The final construct is a knotless double row transosseous equivalent construc...

A study on lead equivalent

International Nuclear Information System (INIS)

Lin Guanxin

1991-01-01

A study on the rules in which the lead equivalent of lead glass changes with the energy of X rays or γ ray is described. The reason of this change is discussed and a new testing method of lead equivalent is suggested

Analytical and numerical construction of equivalent cables.

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Lindsay, K A; Rosenberg, J R; Tucker, G

2003-08-01

The mathematical complexity experienced when applying cable theory to arbitrarily branched dendrites has lead to the development of a simple representation of any branched dendrite called the equivalent cable. The equivalent cable is an unbranched model of a dendrite and a one-to-one mapping of potentials and currents on the branched model to those on the unbranched model, and vice versa. The piecewise uniform cable, with a symmetrised tri-diagonal system matrix, is shown to represent the canonical form for an equivalent cable. Through a novel application of the Laplace transform it is demonstrated that an arbitrary branched model of a dendrite can be transformed to the canonical form of an equivalent cable. The characteristic properties of the equivalent cable are extracted from the matrix for the transformed branched model. The one-to-one mapping follows automatically from the construction of the equivalent cable. The equivalent cable is used to provide a new procedure for characterising the location of synaptic contacts on spinal interneurons.

Syntheses, Characterization, Resolution, and Biological Studies of Coordination Compounds of Aspartic Acid and Glycine

Science.gov (United States)

Akinkunmi, Ezekiel; Ojo, Isaac; Adebajo, Clement; Isabirye, David

2017-01-01

Enantiomerically enriched coordination compounds of aspartic acid and racemic mixtures of coordination compounds of glycine metal-ligand ratio 1 : 3 were synthesized and characterized using infrared and UV-Vis spectrophotometric techniques and magnetic susceptibility measurements. Five of the complexes were resolved using (+)-cis-dichlorobis(ethylenediamine)cobalt(III) chloride, (+)-bis(glycinato)(1,10-phenanthroline)cobalt(III) chloride, and (+)-tris(1,10-phenanthroline)nickel(II) chloride as resolving agents. The antimicrobial and cytotoxic activities of these complexes were then determined. The results obtained indicated that aspartic acid and glycine coordinated in a bidentate fashion. The enantiomeric purity of the compounds was in the range of 22.10–32.10%, with (+)-cis-dichlorobis(ethylenediamine)cobalt(III) complex as the more efficient resolving agent. The resolved complexes exhibited better activity in some cases compared to the parent complexes for both biological activities. It was therefore inferred that although the increase in the lipophilicity of the complexes may assist in the permeability of the complexes through the cell membrane of the pathogens, the enantiomeric purity of the complexes is also of importance in their activity as antimicrobial and cytotoxic agents. PMID:28293149

Establishing Substantial Equivalence: Transcriptomics

Science.gov (United States)

Baudo, María Marcela; Powers, Stephen J.; Mitchell, Rowan A. C.; Shewry, Peter R.

Regulatory authorities in Western Europe require transgenic crops to be substantially equivalent to conventionally bred forms if they are to be approved for commercial production. One way to establish substantial equivalence is to compare the transcript profiles of developing grain and other tissues of transgenic and conventionally bred lines, in order to identify any unintended effects of the transformation process. We present detailed protocols for transcriptomic comparisons of developing wheat grain and leaf material, and illustrate their use by reference to our own studies of lines transformed to express additional gluten protein genes controlled by their own endosperm-specific promoters. The results show that the transgenes present in these lines (which included those encoding marker genes) did not have any significant unpredicted effects on the expression of endogenous genes and that the transgenic plants were therefore substantially equivalent to the corresponding parental lines.

A Comparative Study on Phytochemical Profiles and Biological Activities of Sclerocarya birrea (A.Rich. Hochst Leaf and Bark Extracts

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Daniela Russo

2018-01-01

Full Text Available Sclerocarya birrea (A.Rich. Hochst (Anacardiaceae is a savannah tree that has long been used in sub-Saharan Africa as a medicinal remedy for numerous ailments. The purpose of this study was to increase the scientific knowledge about this plant by evaluating the total content of polyphenols, flavonoids, and tannins in the methanol extracts of the leaves and bark (MLE and MBE, respectively, as well as the in vitro antioxidant activity and biological activities of these extracts. Reported results show that MLE is rich in flavonoids (132.7 ± 10.4 mg of quercetin equivalents/g, whereas MBE has the highest content of tannins (949.5 ± 29.7 mg of tannic acid equivalents/g. The antioxidant activity was measured using four different in vitro tests: β-carotene bleaching (BCB, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS, O2−•, and nitric oxide (NO• assays. In all cases, MBE was the most active compared to MLE and the standards used (Trolox and ascorbic acid. Furthermore, MBE and MLE were tested to evaluate their activity in HepG2 and fibroblast cell lines. A higher cytotoxic activity of MBE was evidenced and confirmed by more pronounced alterations in cell morphology. MBE induced cell death, triggering the intrinsic apoptotic pathway by reactive oxygen species (ROS generation, which led to a loss of mitochondrial membrane potential with subsequent cytochrome c release from the mitochondria into the cytosol. Moreover, MBE showed lower cytotoxicity in normal human dermal fibroblasts, suggesting its potential as a selective anticancer agent.

On uncertainties in definition of dose equivalent

International Nuclear Information System (INIS)

Oda, Keiji

1995-01-01

The author has entertained always the doubt that in a neutron field, if the measured value of the absorbed dose with a tissue equivalent ionization chamber is 1.02±0.01 mGy, may the dose equivalent be taken as 10.2±0.1 mSv. Should it be 10.2 or 11, but the author considers it is 10 or 20. Even if effort is exerted for the precision measurement of absorbed dose, if the coefficient being multiplied to it is not precise, it is meaningless. [Absorbed dose] x [Radiation quality fctor] = [Dose equivalent] seems peculiar. How accurately can dose equivalent be evaluated ? The descriptions related to uncertainties in the publications of ICRU and ICRP are introduced, which are related to radiation quality factor, the accuracy of measuring dose equivalent and so on. Dose equivalent shows the criterion for the degree of risk, or it is considered only as a controlling quantity. The description in the ICRU report 1973 related to dose equivalent and its unit is cited. It was concluded that dose equivalent can be considered only as the absorbed dose being multiplied by a dimensionless factor. The author presented the questions. (K.I.)

Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

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Gallyamov, Marat O., E-mail: glm@spm.phys.msu.ru [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Chaschin, Ivan S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Khokhlova, Marina A. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Grigorev, Timofey E. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E. [Bakulev Scientific Center for Cardiovascular Surgery of the Russian Academy of Medical Sciences, Roublyevskoe Sh. 135, Moscow 121552 (Russian Federation); Badun, Gennadii A.; Chernysheva, Maria G. [Radiochemistry Division, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Khokhlov, Alexei R. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation)

2014-04-01

Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H{sub 2}O and CO{sub 2}. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA

Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

International Nuclear Information System (INIS)

Gallyamov, Marat O.; Chaschin, Ivan S.; Khokhlova, Marina A.; Grigorev, Timofey E.; Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E.; Badun, Gennadii A.; Chernysheva, Maria G.; Khokhlov, Alexei R.

2014-01-01

Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H 2 O and CO 2 . Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA-stabilised bovine

Combined photo-Fenton and biological treatment for Diuron and Linuron removal from water containing humic acid

International Nuclear Information System (INIS)

Farre, Maria Jose; Domenech, Xavier; Peral, Jose

2007-01-01

A combined chemical (photo-Fenton) and biological treatment has been proposed for Diuron and Linuron degradation in water containing natural dissolved organic matter (DOM). Humic acid (HA) was used to simulate the DOM. During the photo-Fenton process ([Fe(II)]=15.9mgL -1 , [H 2 O 2 ]=202mgL -1 , 60min of UVA irradiation time), the chemical oxygen demand (COD), total organic carbon (TOC), toxicity (EC 50 15 ) and biodegradability (BOD 5 /COD) of the generated intermediates were assessed. A reduction of photo-Fenton efficiency was observed when HA was present in solution. This effect has been explained as the result of a UVA light screening as well as a OH? radical quenching process by the HA. After the photo-Fenton process, the initial toxic and non-biodegradable herbicides were transformed into intermediates suitable for a subsequent aerobic biological treatment that was performed in a sequencing batch reactor (SBR). Complete elimination of the intermediates in presence of HA was reached at the end of the chemical-biological coupled system. Biosorption of HA onto the aerobic biomass was characterized. The results indicate that the Freundlich model adequately describes the adsorption of HA, a phenomena that follows a pseudo second-order adsorption kinetic model

Combined photo-Fenton and biological treatment for Diuron and Linuron removal from water containing humic acid

Energy Technology Data Exchange (ETDEWEB)

Farre, Maria Jose [Departament de Quimica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Domenech, Xavier [Departament de Quimica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Peral, Jose [Departament de Quimica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain)]. E-mail: jose.peral@uab.es

2007-08-17

A combined chemical (photo-Fenton) and biological treatment has been proposed for Diuron and Linuron degradation in water containing natural dissolved organic matter (DOM). Humic acid (HA) was used to simulate the DOM. During the photo-Fenton process ([Fe(II)]=15.9mgL{sup -1}, [H{sub 2}O{sub 2}]=202mgL{sup -1}, 60min of UVA irradiation time), the chemical oxygen demand (COD), total organic carbon (TOC), toxicity (EC{sub 50}{sup 15}) and biodegradability (BOD{sub 5}/COD) of the generated intermediates were assessed. A reduction of photo-Fenton efficiency was observed when HA was present in solution. This effect has been explained as the result of a UVA light screening as well as a OH? radical quenching process by the HA. After the photo-Fenton process, the initial toxic and non-biodegradable herbicides were transformed into intermediates suitable for a subsequent aerobic biological treatment that was performed in a sequencing batch reactor (SBR). Complete elimination of the intermediates in presence of HA was reached at the end of the chemical-biological coupled system. Biosorption of HA onto the aerobic biomass was characterized. The results indicate that the Freundlich model adequately describes the adsorption of HA, a phenomena that follows a pseudo second-order adsorption kinetic model.

Interaction of uranium(VI) with bioligands present in human biological fluids. The case study of urea and uric acid

International Nuclear Information System (INIS)

Osman, A.A.A.; Geipel, G.; Bernhard, G.

2013-01-01

The complexation of uranium(VI) with bioligands found in human biological fluids, viz, urea and uric acid in aqueous solutions, has been investigated using time-resolved laser-induced fluorescence spectroscopy (TRLFS) at room temperature, I = 0.1 M (NaClO4) and pH (3 for uric acid; 4 for urea). In both complex systems a static quench effect with increasing ligand concentration and no peaks shift upon complexation were observed. With uranium(VI) both ligands formed a fairly weak 1:1 complex with average stability constants of log β 110 = 4.67 ± 0.29 for uric acid and log β 110 = 3.79 ± 0.15 and 2.12 ± 0.18 for relatively low and relatively high urea concentrations, respectively. Application of the newly generated data on the U(VI) speciation modelling in biofluids, e.g., human urine was also discussed.

Interaction of uranium(VI) with bioligands present in human biological fluids. The case study of urea and uric acid

Energy Technology Data Exchange (ETDEWEB)

Osman, A.A.A.; Geipel, G.; Bernhard, G. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Inst. of Resource Ecology

2013-05-01

The complexation of uranium(VI) with bioligands found in human biological fluids, viz, urea and uric acid in aqueous solutions, has been investigated using time-resolved laser-induced fluorescence spectroscopy (TRLFS) at room temperature, I = 0.1 M (NaClO4) and pH (3 for uric acid; 4 for urea). In both complex systems a static quench effect with increasing ligand concentration and no peaks shift upon complexation were observed. With uranium(VI) both ligands formed a fairly weak 1:1 complex with average stability constants of log {beta}{sub 110} = 4.67 {+-} 0.29 for uric acid and log {beta}{sub 110} = 3.79 {+-} 0.15 and 2.12 {+-} 0.18 for relatively low and relatively high urea concentrations, respectively. Application of the newly generated data on the U(VI) speciation modelling in biofluids, e.g., human urine was also discussed.

Biological functions of iduronic acid in chondroitin/dermatan sulfate.

Science.gov (United States)

Thelin, Martin A; Bartolini, Barbara; Axelsson, Jakob; Gustafsson, Renata; Tykesson, Emil; Pera, Edgar; Oldberg, Åke; Maccarana, Marco; Malmstrom, Anders

2013-05-01

The presence of iduronic acid in chondroitin/dermatan sulfate changes the properties of the polysaccharides because it generates a more flexible chain with increased binding potentials. Iduronic acid in chondroitin/dermatan sulfate influences multiple cellular properties, such as migration, proliferation, differentiation, angiogenesis and the regulation of cytokine/growth factor activities. Under pathological conditions such as wound healing, inflammation and cancer, iduronic acid has diverse regulatory functions. Iduronic acid is formed by two epimerases (i.e. dermatan sulfate epimerase 1 and 2) that have different tissue distribution and properties. The role of iduronic acid in chondroitin/dermatan sulfate is highlighted by the vast changes in connective tissue features in patients with a new type of Ehler-Danlos syndrome: adducted thumb-clubfoot syndrome. Future research aims to understand the roles of the two epimerases and their interplay with the sulfotransferases involved in chondroitin sulfate/dermatan sulfate biosynthesis. Furthermore, a better definition of chondroitin/dermatan sulfate functions using different knockout models is needed. In this review, we focus on the two enzymes responsible for iduronic acid formation, as well as the role of iduronic acid in health and disease. © 2013 The Authors Journal compilation © 2013 FEBS.

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

Science.gov (United States)

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

The sporostatic effect of cannabidiolic acid

International Nuclear Information System (INIS)

Farkas, J.; Andrassy, E.

1976-01-01

A study was undertaken to clarify whether cannabidiolic acid could be made to enhance the microbiological effect of food preservation by heat treatment or irradiation. Cannabidiolic acid was found to have a high inhibiting effect on the spores of Bacillus cereus. Its sporostatic effect is roughly equivalent to that of the antibiotics nisin and tylosin. The aqueous solution of the phytoncide of 50 μg ml -1 concentration (containing 2.5% alcohol) resisted, without a reduction of its activity, a heat treatment of 30 min at 110 deg C. Its activity was reduced by only 15% upon treatment with 400 krad. Hereafter the influence of cannabidiolic acid, added to the brine of canned peas at a concentration of 10 μgml -1 , was studied on samples exposed to treatment with 500 krad or given a heat treatment equivalent to F 0 =4.8. In these combination treatments cannabidiolic acid added at the above concentration proved to be ineffective. On investigating the cause of this phenomenon, cannabidiolic acid was found to react with protein of peas prior to irradiation or heat treatment, or in an early phase of treatment loosing thereby its microbiological effect. On the other hand, since cannabidiolic acid cannot react with proteins denatured by heat, it was found active in a sterilized nutrient medium containing denatured protein. (F.J.)

Determination of the Fatty Acid Content of Biological Membranes: A Highly Versatile GC-MS Experiment

Science.gov (United States)

Schultz, Emeric; Pugh, Michael Eugene

2001-07-01

The experiment involves the GC-MS of fatty acid methyl esters (FAMEs) obtained from bacterial membranes. It takes about 2 h, from cell harvest to injection. This experiment is done in a lab course for non-science majors and in biochemistry. For non-science majors the focus is on GC-MS as a technique for fingerprinting and on the underlying basis of that fingerprinting. In biochemistry the focus is on the composition of membranes and how this changes with temperature--specifically how the ratio of saturated to unsaturated fatty acids changes to maintain constant cell fluidity. Combined with a parallel DNA experiment, the two major types of intermolecular forces important for the structure and function of biomolecules are compared. How this versatile experiment could be adapted in other chemistry courses is presented. The experiment has obvious appeal to biology majors, can be used to develop several important chemistry concepts, involves teamwork, and employs an important instrument. It could be used in the laboratory portion of a course other than biochemistry to fulfill the new ACS biochemistry requirement.

Ozonisation of model compounds as a pretreatment step for the biological wastewater treatment

International Nuclear Information System (INIS)

Degen, U.

1979-11-01

Biological degradability and toxicity of organic substances are two basic criteria determining their behaviour in natural environment and during the biological treatment of waste waters. In this work oxidation products of model compounds (p-toluenesulfonic acid, benzenesulfonic acid and aniline) generated by ozonation were tested in a two step laboratory plant with activated sludge. The organic oxidation products and the initial compounds were the sole source of carbon for the microbes of the adapted activated sludge. The progress of elimination of the compounds was studied by measuring DOC, COD, UV-spectra of the initial compounds and sulfate. Initial concentrations of the model compounds were 2-4 mmole/1 with 25-75ion of sulfonic acids. As oxidation products of p-toluenesulfonic acid the following compounds were identified and quantitatively measured: methylglyoxal, pyruvic acid, oxalic acid, acetic acid, formic acid and sulfate. With all the various solutions with different concentrations of initial compounds and oxidation products the biological activity in the two step laboratory plant could maintain. p-Toluenesulfonic acid and the oxidation products are biologically degraded. The degradation of p-toluenesulfonic acid is measured by following the increasing of the sulfate concentration after biological treatment. This shows that the elimination of p-toluenesulfonic acid is not an adsorption but a mineralization step. At high p-toluenesulfonic acid concentration and low concentration of oxidation products p-toluenesulfonic acid is eliminated with a high efficiency (4.3 mole/d m 3 = 0.34 kg p-toluenesulfonic acid/d m 3 ). However at high concentration of oxidation products p-toluenesulfonic acid is less degraded. The oxidation products are always degraded with an elimination efficiency of 70%. A high load of biologically degradable oxidation products diminished the elimination efficiency of p-toluenesulfonic acid. (orig.) [de

Changes in stream chemistry and biology in response to reduced levels of acid deposition during 1987-2003 in the Neversink River Basin, Catskill Mountains

Science.gov (United States)

Burns, Douglas A.; Riva-Murray, K.; Bode, R.W.; Passy, S.

2008-01-01

Atmospheric acid deposition has decreased in the northeastern United States since the 1970s, resulting in modest increases in pH, acid-neutralizing capacity (ANC), and decreases in inorganic monomeric aluminum (AlIM) concentrations since stream chemistry monitoring began in the 1980s in the acid-sensitive upper Neversink River basin in the Catskill Mountains of New York. Stream pH has increased by 0.01 units/year during 1987-2003 at three sites in the Neversink basin as determined by Seasonal Kendall trend analysis. In light of this observed decrease in stream acidity, we sampled 12 stream sites within the Neversink River watershed for water chemistry, macroinvertebrates, fish, and periphytic diatoms in 2003 to compare with a similar data set collected in 1987. Metrics and indices that reflect sensitivity to stream acidity were developed with these biological data to determine whether changes in stream biota over the intervening 16 years parallel those of stream chemistry. Statistical comparisons of data on stream chemistry and an acid biological assessment profile (Acid BAP) derived from invertebrate data showed no significant differences between the two years. For pH and ANC, however, values in 2003 were generally lower than those in 1987; this difference likely resulted from higher streamflow in summer 2003. Despite these likely flow-induced changes in summer 2003, an ordination and cluster analysis of macroinvertebrate taxa based on the Acid BAP indicated that the most acidic sites in the upstream half of the East Branch Neversink River form a statistically significant separate cluster consistent with less acidic stream conditions. This analysis is consistent with limited recovery of invertebrate species in the most acidic reaches of the river, but will require additional improvement in stream chemistry before a stronger conclusion can be drawn. Data on the fish and periphytic diatom communities in 2003 indicate that slimy sculpin had not extended their habitat

Equivalent Simplification Method of Micro-Grid

OpenAIRE

Cai Changchun; Cao Xiangqin

2013-01-01

The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are per...

Equivalence relations and the reinforcement contingency.

Science.gov (United States)

Sidman, M

2000-07-01

Where do equivalence relations come from? One possible answer is that they arise directly from the reinforcement contingency. That is to say, a reinforcement contingency produces two types of outcome: (a) 2-, 3-, 4-, 5-, or n-term units of analysis that are known, respectively, as operant reinforcement, simple discrimination, conditional discrimination, second-order conditional discrimination, and so on; and (b) equivalence relations that consist of ordered pairs of all positive elements that participate in the contingency. This conception of the origin of equivalence relations leads to a number of new and verifiable ways of conceptualizing equivalence relations and, more generally, the stimulus control of operant behavior. The theory is also capable of experimental disproof.

Equivalence Principle, Higgs Boson and Cosmology

Directory of Open Access Journals (Sweden)

Mauro Francaviglia

2013-05-01

Full Text Available We discuss here possible tests for Palatini f(R-theories together with their implications for different formulations of the Equivalence Principle. We shall show that Palatini f(R-theories obey the Weak Equivalence Principle and violate the Strong Equivalence Principle. The violations of the Strong Equivalence Principle vanish in vacuum (and purely electromagnetic solutions as well as on short time scales with respect to the age of the universe. However, we suggest that a framework based on Palatini f(R-theories is more general than standard General Relativity (GR and it sheds light on the interpretation of data and results in a way which is more model independent than standard GR itself.

High biological variation of serum hyaluronic acid and Hepascore, a biochemical marker model for the prediction of liver fibrosis.

Science.gov (United States)

Rossi, Enrico; Adams, Leon A; Ching, Helena L; Bulsara, Max; MacQuillan, Gerry C; Jeffrey, Gary P

2013-05-01

Serum hyaluronic acid and biochemical models which require hyaluronic acid analysis are commonly used as predictors of liver fibrosis in patients with chronic liver disease, however biological variation data for hyaluronic acid are deficient. Four serial serum samples were obtained at weekly intervals from healthy volunteers and patients with chronic hepatitis B, chronic hepatitis C and non- alcoholic fatty liver disease (NAFLD; 20 in each group). The within-individual week-to-week variation (CVI) and reference change values for hyaluronic acid, α₂-macroglobulin and Hepascore were obtained. Hepascore is calculated from hyaluronic acid, α2-macroglobulin, bilirubin and γ-glutamyltransferase activity. Hyaluronic acid displayed large within-individual variation, the CVI values were 62% in healthy subjects, 38% in hepatitis C, 37% in hepatitis B and 36% in NAFLD patients. Hepascore CVIs were 43% in healthy subjects, 24% in hepatitis C, 28% in hepatitis B and 39% in NAFLD patients. α₂-Macroglobulin was much less variable with CVIs ranging from 4.4% to 7.6%. Bland-Altman plots of week-to-week variations showed rates of significant disagreement for samples collected in any 2 successive weeks varied from 5% in NAFLD patients to 8.3% in healthy subjects. When using non-fasting serum samples, hyaluronic acid and to a lesser extent, the Hepascore model display large within-individual variations in both health and chronic liver disease. This information is critical for interpreting the significance of both single measurements and changes in serial measurements.

Interactive short-term effects of equivalent temperature and air pollution on human mortality in Berlin and Lisbon.

Science.gov (United States)

Burkart, Katrin; Canário, Paulo; Breitner, Susanne; Schneider, Alexandra; Scherber, Katharina; Andrade, Henrique; Alcoforado, Maria João; Endlicher, Wilfried

2013-12-01

There is substantial evidence that both temperature and air pollution are predictors of mortality. Thus far, few studies have focused on the potential interactive effects between the thermal environment and different measures of air pollution. Such interactions, however, are biologically plausible, as (extreme) temperature or increased air pollution might make individuals more susceptible to the effects of each respective predictor. This study investigated the interactive effects between equivalent temperature and air pollution (ozone and particulate matter) in Berlin (Germany) and Lisbon (Portugal) using different types of Poisson regression models. The findings suggest that interactive effects exist between air pollutants and equivalent temperature. Bivariate response surface models and generalised additive models (GAMs) including interaction terms showed an increased risk of mortality during periods of elevated equivalent temperatures and air pollution. Cold effects were mostly unaffected by air pollution. The study underscores the importance of air pollution control in mitigating heat effects. Copyright © 2013 Elsevier Ltd. All rights reserved.

Symmetries of dynamically equivalent theories

Energy Technology Data Exchange (ETDEWEB)

Gitman, D.M.; Tyutin, I.V. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Lebedev Physics Institute, Moscow (Russian Federation)

2006-03-15

A natural and very important development of constrained system theory is a detail study of the relation between the constraint structure in the Hamiltonian formulation with specific features of the theory in the Lagrangian formulation, especially the relation between the constraint structure with the symmetries of the Lagrangian action. An important preliminary step in this direction is a strict demonstration, and this is the aim of the present article, that the symmetry structures of the Hamiltonian action and of the Lagrangian action are the same. This proved, it is sufficient to consider the symmetry structure of the Hamiltonian action. The latter problem is, in some sense, simpler because the Hamiltonian action is a first-order action. At the same time, the study of the symmetry of the Hamiltonian action naturally involves Hamiltonian constraints as basic objects. One can see that the Lagrangian and Hamiltonian actions are dynamically equivalent. This is why, in the present article, we consider from the very beginning a more general problem: how the symmetry structures of dynamically equivalent actions are related. First, we present some necessary notions and relations concerning infinitesimal symmetries in general, as well as a strict definition of dynamically equivalent actions. Finally, we demonstrate that there exists an isomorphism between classes of equivalent symmetries of dynamically equivalent actions. (author)

Selective optical sensing of biothiols with Ellman's reagent: 5,5'-Dithio-bis(2-nitrobenzoic acid)-modified gold nanoparticles.

Science.gov (United States)

Güçlü, Kubilay; Ozyürek, Mustafa; Güngör, Nilay; Baki, Sefa; Apak, Reşat

2013-09-10

Development of sensitive and selective methods of determination for biothiols is important because of their significant roles in biological systems. We present a new optical sensor using Ellman's reagent (DTNB)-adsorbed gold nanoparticles (Au-NPs) (DTNB-Au-NP) in a colloidal solution devised to selectively determine biologically important thiols (biothiols) from biological samples and pharmaceuticals. 5,5'-Dithio-bis(2-nitrobenzoic acid) (DTNB), a versatile water-soluble compound for quantitating free sulfhydryl groups in solution, was adsorbed through non-covalent interaction onto Au-NPs, and the absorbance changes associated with the formation of the yellow-colored 5-thio-2-nitrobenzoate (TNB(2-)) anion as a result of reaction with biothiols was measured at 410nm. The sensor gave a linear response over a wide concentration range of standard biothiols comprising cysteine, glutathione, homocysteine, cysteamine, dihydrolipoic acid and 1,4-dithioerythritol. The calibration curves of individual biothiols were constructed, and their molar absorptivities and linear concentration ranges determined. The cysteine equivalent thiol content (CETC) values of various biothiols using the DTNB-Au-NP assay were comparable to those of the conventional DTNB assay, showing that the immobilized DTNB reagent retained its reactivity toward thiols. Common biological sample ingredients like amino acids, flavonoids, vitamins, and plasma antioxidants did not interfere with the proposed sensing method. This assay was validated through linearity, additivity, precision and recovery, demonstrating that the assay is reliable and robust. DTNB-adsorbed Au-NPs probes provided higher sensitivity (i.e., lower detection limits) in biothiol determination than conventional DTNB reagent. Under optimized conditions, cysteine (Cys) was quantified by the proposed assay, with a detection limit (LOD) of 0.57μM and acceptable linearity ranging from 0.4 to 29.0μM (r=0.998). Copyright © 2013 Elsevier B.V. All

Calculation methods for determining dose equivalent

International Nuclear Information System (INIS)

Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

1988-01-01

A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed

Glyphosate-tolerant soybeans remain compositionally equivalent to conventional soybeans (Glycine max L.) during three years of field testing.

Science.gov (United States)

McCann, Melinda C; Liu, Keshun; Trujillo, William A; Dobert, Raymond C

2005-06-29

Previous studies have shown that the composition of glyphosate-tolerant soybeans (GTS) and selected processed fractions was substantially equivalent to that of conventional soybeans over a wide range of analytes. This study was designed to determine if the composition of GTS remains substantially equivalent to conventional soybeans over the course of several years and when introduced into multiple genetic backgrounds. Soybean seed samples of both GTS and conventional varieties were harvested during 2000, 2001, and 2002 and analyzed for the levels of proximates, lectin, trypsin inhibitor, and isoflavones. The measured analytes are representative of the basic nutritional and biologically active components in soybeans. Results show a similar range of natural variability for the GTS soybeans as well as conventional soybeans. It was concluded that the composition of commercial GTS over the three years of breeding into multiple varieties remains equivalent to that of conventional soybeans.

Characterization of Destrins with Different Dextrose Equivalents

Directory of Open Access Journals (Sweden)

Guanglei Li

2010-07-01

Full Text Available Dextrins are widely used for their functional properties and prepared by partial hydrolysis of starch using acid, enzymes, or combinations of both. The physiochemical properties of dextrins are dependent on their molecular distribution and oligosaccharide profiles. In this study, scanning electron microscopy (SEM, X-ray diffractometry (XRD, rapid viscoanalysis (RVA, high-performance Liquid Chromatography (HPLC and gel permeation chromatography (GPC were used to characterize dextrins prepared by common neutral and thermostable α-amylase hydrolysis. The dextrin granules displayed irregular surfaces and were badly damaged by the enzyme treatment. They displayed A-type X-ray diffraction patterns with a decrease of intensity of the characteristic diffraction peaks. The RVA profiles showed that the viscosity of dextrin decreased with the increase of its Dextrose Equivalent (DE value. According to HPLC analysis, the molecular weight, degree of polymerization and the composition of oligosaccharides in dextrins were different.

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

Science.gov (United States)

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

2017-04-10

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

A Review of Analytical Methods for p-Coumaric Acid in Plant-Based Products, Beverages, and Biological Matrices.

Science.gov (United States)

Ferreira, Paula Scanavez; Victorelli, Francesca Damiani; Fonseca-Santos, Bruno; Chorilli, Marlus

2018-05-14

p-Coumaric acid (p-CA), also known as 4-hydroxycinnamic acid, is a phenolic acid, which has been widely studied due to its beneficial effects against several diseases and its wide distribution in the plant kingdom. This phenolic compound can be found in the free form or conjugated with other molecules; therefore, its bioavailability and the pathways via which it is metabolized change according to its chemical structure. p-CA has potential pharmacological effects because it has high free radical scavenging, anti-inflammatory, antineoplastic, and antimicrobial activities, among other biological properties. It is therefore essential to choose the most appropriate and effective analytical method for qualitative and quantitative determination of p-CA in different matrices, such as plasma, urine, plant extracts, and drug delivery systems. The most-reported analytical method for this purpose is high-performance liquid chromatography, which is mostly coupled with some type of detectors, such as UV/Vis detector. However, other analytical techniques are also used to evaluate this compound. This review presents a summary of p-CA in terms of its chemical and pharmacokinetic properties, pharmacological effects, drug delivery systems, and the analytical methods described in the literature that are suitable for its quantification.

Interactive short-term effects of equivalent temperature and air pollution on human mortality in Berlin and Lisbon

International Nuclear Information System (INIS)

Burkart, Katrin; Canário, Paulo; Breitner, Susanne; Schneider, Alexandra; Scherber, Katharina; Andrade, Henrique; Alcoforado, Maria João; Endlicher, Wilfried

2013-01-01

There is substantial evidence that both temperature and air pollution are predictors of mortality. Thus far, few studies have focused on the potential interactive effects between the thermal environment and different measures of air pollution. Such interactions, however, are biologically plausible, as (extreme) temperature or increased air pollution might make individuals more susceptible to the effects of each respective predictor. This study investigated the interactive effects between equivalent temperature and air pollution (ozone and particulate matter) in Berlin (Germany) and Lisbon (Portugal) using different types of Poisson regression models. The findings suggest that interactive effects exist between air pollutants and equivalent temperature. Bivariate response surface models and generalised additive models (GAMs) including interaction terms showed an increased risk of mortality during periods of elevated equivalent temperatures and air pollution. Cold effects were mostly unaffected by air pollution. The study underscores the importance of air pollution control in mitigating heat effects. -- Highlights: • Interactive effects between air pollution and equivalent temperature result in augmented excess mortality. • High levels of ozone and particulate matter increase adverse heat effects on human mortality. • Cold effects are mostly unaffected by air pollution. • Findings underscore the importance of air pollution control in mitigating heat-related mortality. -- Interactive effects between air pollution and elevated (equivalent) temperatures underscore the importance of air pollution control in mitigating the adverse effects of heat

Fluorescent Proteins for Investigating Biological Events in Acidic Environments

Directory of Open Access Journals (Sweden)

Hajime Shinoda

2018-05-01

Full Text Available The interior lumen of acidic organelles (e.g., endosomes, secretory granules, lysosomes and plant vacuoles is an important platform for modification, transport and degradation of biomolecules as well as signal transduction, which remains challenging to investigate using conventional fluorescent proteins (FPs. Due to the highly acidic luminal environment (pH ~ 4.5–6.0, most FPs and related sensors are apt to lose their fluorescence. To address the need to image in acidic environments, several research groups have developed acid-tolerant FPs in a wide color range. Furthermore, the engineering of pH insensitive sensors, and their concomitant use with pH sensitive sensors for the purpose of pH-calibration has enabled characterization of the role of luminal ions. In this short review, we summarize the recent development of acid-tolerant FPs and related functional sensors and discuss the future prospects for this field.

The one-dimensional normalised generalised equivalence theory (NGET) for generating equivalent diffusion theory group constants for PWR reflector regions

International Nuclear Information System (INIS)

Mueller, E.Z.

1991-01-01

An equivalent diffusion theory PWR reflector model is presented, which has as its basis Smith's generalisation of Koebke's Equivalent Theory. This method is an adaptation, in one-dimensional slab geometry, of the Generalised Equivalence Theory (GET). Since the method involves the renormalisation of the GET discontinuity factors at nodal interfaces, it is called the Normalised Generalised Equivalence Theory (NGET) method. The advantages of the NGET method for modelling the ex-core nodes of a PWR are summarized. 23 refs

Biological functions of iduronic acid in chondroitin/dermatan sulfate

OpenAIRE

Thelin, Martin A; Bartolini, Barbara; Axelsson, Jakob; Gustafsson, Renata; Tykesson, Emil; Pera, Edgar; Oldberg, ?ke; Maccarana, Marco; Malmstrom, Anders

2013-01-01

The presence of iduronic acid in chondroitin/dermatan sulfate changes the properties of the polysaccharides because it generates a more flexible chain with increased binding potentials. Iduronic acid in chondroitin/dermatan sulfate influences multiple cellular properties, such as migration, proliferation, differentiation, angiogenesis and the regulation of cytokine/growth factor activities. Under pathological conditions such as wound healing, inflammation and cancer, iduronic acid has diverse...

The definition of the individual dose equivalent

International Nuclear Information System (INIS)

Ehrlich, Margarete

1986-01-01

A brief note examines the choice of the present definition of the individual dose equivalent, the new operational dosimetry quantity for external exposure. The consequences of the use of the individual dose equivalent and the danger facing the individual dose equivalent, as currently defined, are briefly discussed. (UK)

Aspartate and glutamate mimetic structures in biologically active compounds.

Science.gov (United States)

Stefanic, Peter; Dolenc, Marija Sollner

2004-04-01

Glutamate and aspartate are frequently recognized as key structural elements for the biological activity of natural peptides and synthetic compounds. The acidic side-chain functionality of both the amino acids provides the basis for the ionic interaction and subsequent molecular recognition by specific receptor sites that results in the regulation of physiological or pathophysiological processes in the organism. In the development of new biologically active compounds that possess the ability to modulate these processes, compounds offering the same type of interactions are being designed. Thus, using a peptidomimetic design approach, glutamate and aspartate mimetics are incorporated into the structure of final biologically active compounds. This review covers different bioisosteric replacements of carboxylic acid alone, as well as mimetics of the whole amino acid structure. Amino acid analogs presented include those with different distances between anionic moieties, and analogs with additional functional groups that result in conformational restriction or alternative interaction sites. The article also provides an overview of different cyclic structures, including various cycloalkane, bicyclic and heterocyclic analogs, that lead to conformational restriction. Higher di- and tripeptide mimetics in which carboxylic acid functionality is incorporated into larger molecules are also reviewed. In addition to the mimetic structures presented, emphasis in this article is placed on their steric and electronic properties. These mimetics constitute a useful pool of fragments in the design of new biologically active compounds, particularly in the field of RGD mimetics and excitatory amino acid agonists and antagonists.

Environmental Comparison of Biobased Chemicals from Glutamic Acid with Their Petrochemical Equivalents

NARCIS (Netherlands)

Lammens, T.M.; Potting, J.; Sanders, J.P.M.; Boer, de I.J.M.

2011-01-01

Glutamic acid is an important constituent of waste streams from biofuels production. It is an interesting starting material for the synthesis of biobased chemicals, thereby decreasing the dependency on fossil fuels. The objective of this paper was to compare the environmental impact of four biobased

Environmental comparison of biobased chemicals from glutamic acid with their petrochemical equivalents

NARCIS (Netherlands)

Lammens, T.M.; Potting, J.; Sanders, J.P.M.; Boer, de I.J.M.

2012-01-01

Glutamic acid is an important constituent of waste streams from biofuels production. It is an interesting starting material for the synthesis of biobased chemicals, thereby decreasing the dependency on fossil fuels. The objective of this paper was to compare the environmental impact of four biobased

Synthesis, crystal structure and biological activity of 2-hydroxyethylammonium salt of p-aminobenzoic acid.

Directory of Open Access Journals (Sweden)

Manuela E Crisan

Full Text Available p-Aminobenzoic acid (pABA plays important roles in a wide variety of metabolic processes. Herein we report the synthesis, theoretical calculations, crystallographic investigation, and in vitro determination of the biological activity and phytotoxicity of the pABA salt, 2-hydroxyethylammonium p-aminobenzoate (HEA-pABA. The ability of neutral and anionic forms of pABA to interact with TIR1 pocket was investigated by calculation of molecular electrostatic potential maps on the accessible surface area, docking experiments, Molecular Dynamics and Quantum Mechanics/Molecular Mechanics calculations. The docking study of the folate precursor pABA, its anionic form and natural auxin (indole-3-acetic acid, IAA with the auxin receptor TIR1 revealed a similar binding mode in the active site. The phytotoxic evaluation of HEA-pABA, pABA and 2-hydroxyethylamine (HEA was performed on the model plant Arabidopsis thaliana ecotype Col 0 at five different concentrations. HEA-pABA and pABA acted as potential auxin-like regulators of root development in Arabidopsis thaliana (0.1 and 0.2 mM and displayed an agravitropic root response at high concentration (2 mM. This study suggests that HEA-pABA and pABA might be considered as potential new regulators of plant growth.

STRATEGI PEMBELAJARAN, KEMAMPUAN AKADEMIK, KEMAMPUAN PEMECAHAN MASALAH, DAN HASIL BELAJAR BIOLOGI

OpenAIRE

I Wayan Karmana

2012-01-01

Abstract: The Learning Strategy, Academic Capability, Problem Solving Skills, and Cognitive Achievement In Biology. This study investigates the effects of learning strategy, academic capability, and their interaction on problem solving skills, critical thinking, metacognitive awareness, and cognitive achievement in biology. This is a quasi experimental study using pretest-posttest non-equivalent control group design. The sample includes 60 tenth grade students of Senior High School 4 Mataram....

Validation of artificial skin equivalents as in vitro testing systems

Science.gov (United States)

Schmitt, Robert; Marx, Ulrich; Walles, Heike; Schober, Lena

2011-03-01

With the increasing complexity of the chemical composition of pharmaceuticals, cosmetics and everyday substances, the awareness of potential health issues and long term damages for humanoid organs is shifting into focus. Artificial in vitro testing systems play an important role in providing reliable test conditions and replacing precarious animal testing. Especially artificial skin equivalents ASEs are used for a broad spectrum of studies like penetration, irritation and corrosion of substances. One major challenge in tissue engineering is the qualification of each individual ASE as in vitro testing system. Due to biological fluctuations, the stratum corneum hornified layer of some ASEs may not fully develop or other defects might occur. For monitoring these effects we developed an fully automated Optical Coherence Tomography device. Here, we present different methods to characterize and evaluate the quality of the ASEs based on image and data processing of OCT B-scans. By analysing the surface structure, defects, like cuts or tears, are detectable. A further indicator for the quality of the ASE is the morphology of the tissue. This allows to determine if the skin model has reached the final growth state. We found, that OCT is a well suited technology for automatically characterizing artificial skin equivalents and validating the application as testing system.

77 FR 32632 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

Science.gov (United States)

2012-06-01

... Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION... accordance with 40 CFR Part 53, three new equivalent methods: One for measuring concentrations of nitrogen... INFORMATION: In accordance with regulations at 40 CFR Part 53, the EPA evaluates various methods for...

A dipstick sensor for coulometric acid-base titrations

NARCIS (Netherlands)

Olthuis, Wouter; van der Schoot, B.H.; Chavez, F.; Bergveld, Piet

1989-01-01

By performing an acid-base titration by coulometric generation of OH− or H+ ions at an inert electrode in close proximity to the pH-sensitive gate of an ISFET, it is possible to determine the acid or base concentration of a solution using the ISFET as an indicator device for the equivalence point in

Beyond Language Equivalence on Visibly Pushdown Automata

DEFF Research Database (Denmark)

Srba, Jiri

2009-01-01

We study (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds for a number of studied...... preorders and equivalences like simulation, completed simulation, ready simulation, 2-nested simulation preorders/equivalences and bisimulation equivalence. Our main results are that all the mentioned equivalences and preorders are EXPTIME-complete on visibly pushdown automata, PSPACE-complete on visibly...... one-counter automata and P-complete on visibly BPA. Our PSPACE lower bound for visibly one-counter automata improves also the previously known DP-hardness results for ordinary one-counter automata and one-counter nets. Finally, we study regularity checking problems for visibly pushdown automata...

Radical Scavenging Capacity of Methanolic Phillyrea latifolia L. Extract: Anthocyanin and Phenolic Acids Composition of Fruits

Directory of Open Access Journals (Sweden)

Naciye Erkan

2013-01-01

Full Text Available Radical scavenging capacity of a crude methanolic extract from the fruits of Phillyrea latifolia L., commonly known as green olive tree or mock privet, was investigated with reference to anthocyanin standards, as flavonoids, and phenolic acid standards, as phenylpropanoids. Characterization with high performance liquid chromatography-diode array detection (HPLC-DAD indicated the presence of keracyanin, kuromanin, cyanidin, ferulic acid, caffeic acid and rosmarinic acid at amounts of 289.1, 90.4, 191.4, 225.2, 221.2 and 190.1 mg/100 g fresh weight (FW of fruits, respectively. Chlorogenic and p-coumaric acids were found to exist in lower amounts. Trolox equivalent antioxidant capacity (TEAC and IC50 values of the plant extract were found to be 1.8 mM Trolox equivalents (TE/g FW of fruits and 69.4 µg/mL, respectively, indicating the close radical scavenging activity of the extract to those of keracyanin and p-coumaric acid. The crude methanolic P. latifolia L. fruit extract was seen to be fairly potent in radical scavenging. Total phenolic content (TPC of the plant extract was found to be 1652.9 mg gallic acid equivalent (GAE/100 g FW of fruits.

Acidic deposition: State of science and technology. Report 11. Historical changes in surface-water acid-base chemistry in response to acidic deposition. Final report

International Nuclear Information System (INIS)

Sullivan, T.J.; Small, M.J.; Kingston, J.C.; Bernert, J.A.; Thomas, D.R.

1990-09-01

The objectives of the analyses reported in the State of Science report are to: identify the lake and stream populations in the United States that have experienced chronic changes in biologically significant constituents of surface water chemistry (e.g. pH, Al) in response to acidic deposition; quantify biologically meaningful historical changes in chronic surface water chemistry associated with acidic deposition, with emphasis on ANC, pH, and Al; estimate the proportion of lakes nor acidic that were not acidic in pre-industrial times; estimate the proportional response of each of the major chemical constituents that have changed in response to acidic deposition using a subset of statistically selected Adirondack lakes for which paleolimnological reconstructions of pre-industrial surface water chemistry have been performed; evaluate and improve, where appropriate and feasible, empirical models of predicting changes in ANC; and evaluate the response of seepage lakes to acidic deposition

Mango (Mangifera indica L.) Polyphenols Ameliorate Functional Constipation Symptoms in Humans Beyond Equivalent Amount of Fiber.

Science.gov (United States)

P Venancio, Vinicius; Kim, Hyemee; A Sirven, Maritza; D Tekwe, Carmen; Honvoh, Gilson; T Talcott, Stephen; U Mertens-Talcott, Susanne

2018-05-07

Chronic constipation is a common gastrointestinal condition associated with intestinal inflammation and considerably impaired quality of life, affecting about 20% of Americans. Dietary fiber and laxatives aid in its treatment but do not fully address all symptoms, such as intestinal inflammation. Mango (Mangifera indica L.), a fiber- and polyphenol-rich fruit may provide anti-inflammatory effects in constipation. The 4-week consumption of mango fruit (300 g) or the equivalent amount of fiber was investigated in otherwise healthy human volunteers with chronic constipation that were randomly assigned to either group. Blood and fecal samples and digestive wellness questionnaires were collected at the beginning and end of the study. Results show that mango consumption significantly improved constipation status (stool frequency, consistency, and shape) and increased gastrin levels and fecal concentrations of short chain fatty acid (valeric acid) while lowering endotoxin and interleukin 6 concentrations in plasma. In this pilot study, the consumption of mango improves symptoms and associated biomarkers of constipation beyond an equivalent amount of fiber. Larger follow-up studies would need to investigate biomarkers for intestinal inflammation in more detail. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The equivalence problem for LL- and LR-regular grammars

NARCIS (Netherlands)

Nijholt, Antinus; Gecsec, F.

It will be shown that the equivalence problem for LL-regular grammars is decidable. Apart from extending the known result for LL(k) grammar equivalence to LLregular grammar equivalence, we obtain an alternative proof of the decidability of LL(k) equivalence. The equivalence prob]em for LL-regular

Equivalent damage of loads on pavements

CSIR Research Space (South Africa)

Prozzi, JA

2009-05-26

Full Text Available This report describes a new methodology for the determination of Equivalent Damage Factors (EDFs) of vehicles with multiple axle and wheel configurations on pavements. The basic premise of this new procedure is that "equivalent pavement response...

Chemical-modification studies of a unique sialic acid-binding lectin from the snail Achatina fulica. Involvement of tryptophan and histidine residues in biological activity.

Science.gov (United States)

Basu, S; Mandal, C; Allen, A K

1988-01-01

A unique sialic acid-binding lectin, achatininH (ATNH) was purified in single step from the haemolymph of the snail Achatina fulica by affinity chromatography on sheep submaxillary-gland mucin coupled to Sepharose 4B. The homogeneity was checked by alkaline gel electrophoresis, immunodiffusion and immunoelectrophoresis. Amino acid analysis showed that the lectin has a fairly high content of acidic amino acid residues (22% of the total). About 1.3% of the residues are half-cystine. The glycoprotein contains 21% carbohydrate. The unusually high content of xylose (6%) and fucose (2.7%) in this snail lectin is quite interesting. The protein was subjected to various chemical modifications in order to detect the amino acid residues and carbohydrate residues present in its binding sites. Modification of tyrosine and arginine residues did not affect the binding activity of ATNH; however, modification of tryptophan and histidine residues led to a complete loss of its biological activity. A marked decrease in the fluorescence emission was found as the tryptophan residues of ATNH were modified. The c.d. data showed the presence of an identical type of conformation in the native and modified agglutinin. The modification of lysine and carboxy residues partially diminished the biological activity. The activity was completely lost after a beta-elimination reaction, indicating that the sugars are O-glycosidically linked to the glycoprotein's protein moiety. This result confirms that the carbohydrate moiety also plays an important role in the agglutination property of this lectin. Images Fig. 3. PMID:3140796

7 CFR 1030.54 - Equivalent price.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1030.54 Section 1030.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1030.54 Equivalent price. See § 1000.54. ...

Equivalence in Ventilation and Indoor Air Quality

Energy Technology Data Exchange (ETDEWEB)

Sherman, Max; Walker, Iain; Logue, Jennifer

2011-08-01

We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

Dose of radiation enhancement, using silver nanoparticles in a human tissue equivalent gel dosimeter.

Science.gov (United States)

Hassan, Muhammad; Waheed, Muhammad Mohsin; Anjum, Muhammad Naeem

2016-01-01

To quantify the radiation dose enhancement in a human tissue-equivalent polymer gel impregnated with silver nanoparticles. The case-control study was conducted at the Bahawalpur Institute of Nuclear Medicine and Oncology, Bahawalpur, Pakistan, in January 2014. Silver nanoparticles used in this study were prepared by wet chemical method. Polymer gel was prepared by known quantity of gelatine, methacrylic acid, ascorbic acid, copper sulphate pentahydrate, hydroquinone and water. Different concentrations of silver nanoparticles were added to the gel during its cooling process. The gel was cooled in six plastic vials of 50ml each. Two vials were used as a control sample while four vials were impregnated with silver nanoparticles. After 22 hours, the vials were irradiated with gamma rays by aCobalt-60 unit. Radiation enhancement was assessed by taking magnetic resonance images of the vials. The images were analysed using Image J software. The dose enhancement factor was 24.17% and 40.49% for 5Gy and 10Gy dose respectively. The dose enhancement factor for the gel impregnated with 0.10mM silver nanoparticles was 32.88% and 51.98% for 5Gy and 10Gy dose respectively. The impregnation of a tissue-equivalent gel with silver nanoparticles resulted in dose enhancement and this effect was magnified up to a certain level with the increase in concentration of silver nanoparticles.

Orientifold Planar Equivalence: The Chiral Condensate

DEFF Research Database (Denmark)

Armoni, Adi; Lucini, Biagio; Patella, Agostino

2008-01-01

The recently introduced orientifold planar equivalence is a promising tool for solving non-perturbative problems in QCD. One of the predictions of orientifold planar equivalence is that the chiral condensates of a theory with $N_f$ flavours of Dirac fermions in the symmetric (or antisymmetric...

7 CFR 1005.54 - Equivalent price.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1005.54 Section 1005.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1005.54 Equivalent price. See § 1000.54. Uniform Prices ...

7 CFR 1126.54 - Equivalent price.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1126.54 Section 1126.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1126.54 Equivalent price. See § 1000.54. Producer Price Differential ...

7 CFR 1001.54 - Equivalent price.

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2010-01-01

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7 CFR 1032.54 - Equivalent price.

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2010-01-01

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7 CFR 1033.54 - Equivalent price.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1033.54 Section 1033.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1033.54 Equivalent price. See § 1000.54. Producer Price Differential ...

7 CFR 1131.54 - Equivalent price.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1131.54 Section 1131.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1131.54 Equivalent price. See § 1000.54. Uniform Prices ...

7 CFR 1006.54 - Equivalent price.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1006.54 Section 1006.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1006.54 Equivalent price. See § 1000.54. Uniform Prices ...

7 CFR 1007.54 - Equivalent price.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1007.54 Section 1007.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Class Prices § 1007.54 Equivalent price. See § 1000.54. Uniform Prices ...

Characterization of water reservoirs affected by acid mine drainage: geochemical, mineralogical, and biological (diatoms) properties of the water.

Science.gov (United States)

Valente, T; Rivera, M J; Almeida, S F P; Delgado, C; Gomes, P; Grande, J A; de la Torre, M L; Santisteban, M

2016-04-01

This work presents a combination of geochemical, mineralogical, and biological data obtained in water reservoirs located in one of the most paradigmatic mining regions, suffering from acid mine drainage (AMD) problems: the Iberian Pyrite Belt (IPB). Four water reservoirs located in the Spanish sector of the IBP, storing water for different purposes, were selected to achieve an environmental classification based on the effects of AMD: two mining dams (Gossan and Águas Ácidas), a reservoir for industrial use (Sancho), and one with water used for human supply (Andévalo). The results indicated that the four reservoirs are subject to the effect of metallic loads from polluted rivers, although with different levels: Águas Ácidas > Gossan > Sancho ≥ Andévalo. In accordance, epipsammic diatom communities have differences in the respective composition and dominant taxa. The dominant diatoms in each reservoir indicated acid water: Pinnularia acidophila and Pinnularia aljustrelica were found in the most acidic dams (Gossan and Águas Ácidas, with pH <3), Pinnularia subcapitata in Sancho (pH 2.48-5.82), and Eunotia exigua in Andévalo (pH 2.34-6.15).

The Complexity of Identifying Large Equivalence Classes

DEFF Research Database (Denmark)

Skyum, Sven; Frandsen, Gudmund Skovbjerg; Miltersen, Peter Bro

1999-01-01

We prove that at least 3k−4/k(2k−3)(n/2) – O(k)equivalence tests and no more than 2/k (n/2) + O(n) equivalence tests are needed in the worst case to identify the equivalence classes with at least k members in set of n elements. The upper bound is an improvement by a factor 2 compared to known res...

Interaction between lf electric fields and biological bodies

Directory of Open Access Journals (Sweden)

Češelkoska Vesna C.

2004-01-01

Full Text Available In this paper the Equivalent electrodes method is used for electric field calculation in the proximity of the various biological subjects exposed to an electric field in the LF range. Several results of the electric field intensity on the body surface and numerous graphical results for equipotential and equienergetic curves are presented.

7 CFR 1124.54 - Equivalent price.

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2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1124.54 Section 1124.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Class Prices § 1124.54 Equivalent price. See § 1000.54. Producer Price Differential ...

EQUIVALENT MODELS IN COVARIANCE STRUCTURE-ANALYSIS

NARCIS (Netherlands)

LUIJBEN, TCW

1991-01-01

Defining equivalent models as those that reproduce the same set of covariance matrices, necessary and sufficient conditions are stated for the local equivalence of two expanded identified models M1 and M2 when fitting the more restricted model M0. Assuming several regularity conditions, the rank

[Determination of glutamic acid in biological material by capillary electrophoresis].

Science.gov (United States)

Narezhnaya, E; Krukier, I; Avrutskaya, V; Degtyareva, A; Igumnova, E A

2015-01-01

The conditions for the identification and determination of Glutamic acid by capillary zone electrophoresis without their preliminary derivatization have been optimized. The effect of concentration of buffer electrolyte and pH on determination of Glutamic acid has been investigated. It is shown that the 5 Mm borate buffer concentration and a pH 9.15 are optimal. Quantitative determination of glutamic acid has been carried out using a linear dependence between the concentration of the analyte and the area of the peak. The accuracy and reproducibility of the determination are confirmed by the method "introduced - found". Glutamic acid has been determined in the placenta homogenate. The duration of analysis doesn't exceed 30 minutes. The results showed a decrease in the level of glutamic acid in cases of pregnancy complicated by placental insufficiency compared with the physiological, and this fact allows to consider the level of glutamic acid as a possible marker of complicated pregnancy.

In situ phytoextraction of copper and cadmium and its biological impacts in acidic soil.

Science.gov (United States)

Cui, Hongbiao; Fan, Yuchao; Yang, John; Xu, Lei; Zhou, Jing; Zhu, Zhenqiu

2016-10-01

Phytoremediation is a potential cost-effective technology for remediating heavy metal-contaminated soils. In this study, we evaluated the biomass and accumulation of copper (Cu) and cadmium (Cd) of plant species grown in a contaminated acidic soil treated with limestone. Five species produced biomass in the order: Pennisetum sinese > Elsholtzia splendens > Vetiveria zizanioides > Setaria pumila > Sedum plumbizincicola. Over one growing season, the best accumulators for Cu and Cd were Pennisetum sinese and Sedum plumbizincicola, respectively. Overall, Pennisetum sinese was the best species for Cu and Cd removal when biomass was considered. However, Elsholtzia splendens soil had the highest enzyme activities and microbial populations, while the biological properties in Pennisetum sinese soil were moderately enhanced. Results would provide valuable insights for phytoremediation of metal-contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantum equivalence principle without mass superselection

International Nuclear Information System (INIS)

Hernandez-Coronado, H.; Okon, E.

2013-01-01

The standard argument for the validity of Einstein's equivalence principle in a non-relativistic quantum context involves the application of a mass superselection rule. The objective of this work is to show that, contrary to widespread opinion, the compatibility between the equivalence principle and quantum mechanics does not depend on the introduction of such a restriction. For this purpose, we develop a formalism based on the extended Galileo group, which allows for a consistent handling of superpositions of different masses, and show that, within such scheme, mass superpositions behave as they should in order to obey the equivalence principle. - Highlights: • We propose a formalism for consistently handling, within a non-relativistic quantum context, superpositions of states with different masses. • The formalism utilizes the extended Galileo group, in which mass is a generator. • The proposed formalism allows for the equivalence principle to be satisfied without the need of imposing a mass superselection rule

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

Directory of Open Access Journals (Sweden)

Lucèia Fàtima Souza

2016-09-01

Full Text Available 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.

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

Science.gov (United States)

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.

EUD-based biological optimization for carbon ion therapy

International Nuclear Information System (INIS)

Brüningk, Sarah C.; Kamp, Florian; Wilkens, Jan J.

2015-01-01

Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

Problems of Equivalence in Shona- English Bilingual Dictionaries

African Journals Online (AJOL)

rbr

Page 1 ... translation equivalents in Shona-English dictionaries where lexicographers will be dealing with divergent languages and cultures, traditional practices of lexicography and the absence of reliable ... ideal in translation is to achieve structural and semantic equivalence. Absolute equivalence between any two ...

10 CFR 474.3 - Petroleum-equivalent fuel economy calculation.

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Petroleum-equivalent fuel economy calculation. 474.3..., DEVELOPMENT, AND DEMONSTRATION PROGRAM; PETROLEUM-EQUIVALENT FUEL ECONOMY CALCULATION § 474.3 Petroleum-equivalent fuel economy calculation. (a) The petroleum-equivalent fuel economy for an electric vehicle is...

The ammonium nitrate particle equivalent of NOx emissions for wintertime conditions in Central California's San Joaquin Valley

International Nuclear Information System (INIS)

Stockwell, W.R.; Watson, J.G.; Robinson, N.F.; Sylte, W.W.

2000-01-01

A new method has been developed to assess the aerosol particle formation reactivity of nitrogen oxide (NO x ) emissions. The method involves using a photochemical box model with gas-phase photochemistry, aerosol production and deposition to calculate the ammonium nitrate particle equivalent of NO x emissions. The yields of ammonium nitrate particles used in the box model were determined from parametric simulations made with an equilibrium model that calculated the fraction of nitric acid that reacts to produce ammonium nitrate from the temperature, relative humidity and ammonium-to-nitrate ratios. For the wintertime conditions of emissions and meteorology in the San Joaquin Valley of central California, approximately 80% of the moles of nitric acid produced was found to be in the particulate nitrate phase and about 33% of the moles of emitted NO x was converted to particulate nitrate. The particle equivalent of NO x emissions was found to be on the order of 0.6 g of ammonium nitrate for each gram of NO x emitted (the mass of NO x calculated as NO 2 ). This estimate is in reasonable agreement with an analysis of field measurements made in central California. (author)

Low dimensional equivalence of core neutronics model and its application to transient analysis

International Nuclear Information System (INIS)

Song Hongbing; Zhao Fuyu

2015-01-01

Three-dimensional coupled neutronics thermal-hydraulics reactor analysis is time consuming and occupies huge memory. A one-dimensional model is preferable than the three one in nuclear system analysis, control system design and load following. In this paper, a corewide three dimensional to one dimensional equivalent method has been developed. On the basis of this method 1D axial few groups constants were obtained. The equivalent cross sections were calculated by general spatial homogenization while the transverse buckling was computed through an equivalence based on the 3D flux conservation. Three steady test cases were performed on one dimensional finite difference code ODTAC and the results were compared with TRIVAC-5. The comparison shows that the one dimensional axial power distribution computed by ODTAC correlates well with the three dimensional results calculated by TRIVAC-5. In this study, DRAGON-4 was used to generate the few-group constants of fuel assemblies and the reflector few-group parameters were calculated by WIMS-D4. These collapsed few-group constants were tabulated in a database sorted in ascending order of fuel temperature, coolant temperature and concentration of boric acid. Trilinear interpolation was adopted in cross sections feedback during the transient analysis. In this paper, G1 rod drop accident (RDA) and G1 rod ejection accident (REA) were performed on ODTAC and the computation results were consistent of the physical rules. (author)

Course design via Equivalency Theory supports equivalent student grades and satisfaction in online and face-to-face psychology classes

Directory of Open Access Journals (Sweden)

David eGarratt-Reed

2016-05-01

Full Text Available There has been a recent rapid growth in the number of psychology courses offered online through institutions of higher education. The American Psychological Association (APA has highlighted the importance of ensuring the effectiveness of online psychology courses. Despite this, there have been inconsistent findings regarding student grades, satisfaction, and retention in online psychology units. Equivalency Theory posits that online and classroom-based learners will attain equivalent learning outcomes when equivalent learning experiences are provided. We present a case study of an online introductory psychology unit designed to provide equivalent learning experiences to the pre-existing face-to-face version of the unit. Academic performance, student feedback, and retention data from 866 Australian undergraduate psychology students were examined to assess whether the online unit produced comparable outcomes to the ‘traditional’ unit delivered face-to-face. Student grades did not significantly differ between modes of delivery, except for a group-work based assessment where online students performed more poorly. Student satisfaction was generally high in both modes of the unit, with group-work the key source of dissatisfaction in the online unit. The results provide partial support for Equivalency Theory. The group-work based assessment did not provide an equivalent learning experience for students in the online unit highlighting the need for further research to determine effective methods of engaging students in online group activities. Consistent with previous research, retention rates were significantly lower in the online unit, indicating the need to develop effective strategies to increase online retention rates. While this study demonstrates successes in presenting online students with an equivalent learning experience, we recommend that future research investigates means of successfully facilitating collaborative group-work assessment

Matching of equivalent field regions

DEFF Research Database (Denmark)

Appel-Hansen, Jørgen; Rengarajan, S.B.

2005-01-01

In aperture problems, integral equations for equivalent currents are often found by enforcing matching of equivalent fields. The enforcement is made in the aperture surface region adjoining the two volumes on each side of the aperture. In the case of an aperture in a planar perfectly conducting...... screen, having the same homogeneous medium on both sides and an impressed current on one aide, an alternative procedure is relevant. We make use of the fact that in the aperture the tangential component of the magnetic field due to the induced currents in the screen is zero. The use of such a procedure...... shows that equivalent currents can be found by a consideration of only one of the two volumes into which the aperture plane divides the space. Furthermore, from a consideration of an automatic matching at the aperture, additional information about tangential as well as normal field components...

Influence of length of interval between pulses in PDR brachytherapy (PDRBT on value of Biologically Equivalent Dose (BED in healthy tissues

Directory of Open Access Journals (Sweden)

Tomasz Piotrowski

2010-07-01

Full Text Available Purpose: Different PDR treatment schemas are used in clinical practice, however optimal length of interval between pulses still remains unclear. The aim of this work was to compare value of BED doses measured in surrounded healthy tissues according to different intervals between pulses in PDRBT. Influence of doses optimization on BED values was analyzed.Material and methods: Fifty-one patients treated in Greater Poland Cancer Centre were qualified for calculations.Calculations of doses were made in 51 patients with head and neck cancer, brain tumor, breast cancer, sarcoma, penis cancer and rectal cancer. Doses were calculated with the use of PLATO planning system in chosen critical points in surrounded healthy tissues. For all treatment plans the doses were compared using Biologically Equivalent Dose formula.Three interval lengths (1, 2 and 4 hours between pulses were chosen for calculations. For statistical analysis Friedman ANOVA test and Kendall ratio were used.Results: The median value of BED in chosen critical points in healthy tissues was statistically related to the length of interval between PDR pulses and decreased exponentially with 1 hour interval to 4 hours (Kendall = from 0.48 to 1.0; p = from 0.002 to 0.00001.Conclusions: Prolongation of intervals between pulses in PDR brachytherapy was connected with lower values of BED doses in healthy tissues. It seems that longer intervals between pulses reduced the risk of late complications, but also decreased the tumour control. Furthermore, optimization influenced the increase of doses in healthy tissues.

The Effect of Acid Pre-Treatment using Acetic Acid and Nitric Acid in The Production of Biogas from Rice Husk during Solid State Anaerobic Digestion (SS-AD)

Science.gov (United States)

Nugraha, Winardi Dwi; Syafrudin; Keumala, Cut Fadhila; Matin, Hasfi Hawali Abdul; Budiyono

2018-02-01

Pretreatment during biogas production aims to assist in degradation of lignin contained in the rice husk. In this study, pretreatment which is used are acid and biological pretreatment. Acid pretreatment was performed using acetic acid and nitric acid with a variety levels of 3% and 5%. While biological pretreatment as a control variable. Acid pretreatment was conducted by soaking the rice straw for 24 hours with acid variation. The study was conducted using Solid State Anaerobic Digestion (SS-AD) with 21% TS. Biogas production was measured using water displacement method every two days for 60 days at room temperature conditions. The results showed that acid pretreatment gave an effect on the production of biogas yield. The yield of the biogas produced by pretreatment of acetic acid of 5% and 3% was 43.28 and 45.86 ml/gr.TS. While the results without pretreatment biogas yield was 29.51 ml/gr.TS. The results yield biogas produced by pretreatment using nitric acid of 5% and 3% was 12.14 ml/gr.TS and 21.85 ml/gr.TS. Results biogas yield with acetic acid pretreatment was better than the biogas yield results with nitric acid pretreatment.

Acetic acid production from marine algae. Progress report No. 3, January 1, 1978--March 31, 1978

Energy Technology Data Exchange (ETDEWEB)

Sanderson, J.E.; Wise, D.L.

1978-06-01

The program for acetic acid production from marine algae has made significant progress in the current quarter. Some of the significant developments during this period are: (1) conversion of the available reducing equivalents in Chondrus crispus to organic acids has been carried to better than 80% completion; (2) thermophilic fermentations produce higher ratios of acetic acid to total acid than is the case for mesophilic fermentations (80% vs. 50%); (3) a membrane extraction process for removing organic acid products has been developed which has potential for commercial use; (4) a large scale fermentation was shown to convert over 50% of the available carbon in five days; (5) a reducing equivalents balance on the large scale fermentation was closed to with 96% of theoretical.

Biological activity and biotechnological aspects of locked nucleic acids

DEFF Research Database (Denmark)

Lundin, Karin E; Højland, Torben; Hansen, Bo

2013-01-01

Locked nucleic acid (LNA) is one of the most promising new nucleic acid analogues that has been produced under the past two decades. In this chapter, we have tried to cover many of the different areas, where this molecule has been used to improve the function of synthetic oligonucleotides (ONs). ...

Where Synthetic Biology Meets ET

Science.gov (United States)

Rothschild, Lynn J.

2016-01-01

Synthetic biology - the design and construction of new biological parts and systems and the redesign of existing ones for useful purposes - has the potential to transform fields from pharmaceuticals to fuels. Our lab has focused on the potential of synthetic biology to revolutionize all three major parts of astrobiology: Where do we come from? Where are we going? and Are we alone? For the first and third, synthetic biology is allowing us to answer whether the evolutionary narrative that has played out on planet earth is likely to have been unique or universal. For example, in our lab we are re-evolving the biosynthetic pathways of amino acids in order to understand potential capabilities of an early organism with a limited repertoire of amino acids and developing techniques for the recovery of metals from spent electronics on other planetary bodies. And what about the limits for life? Can we create organisms that expand the envelope for life? In the future synthetic biology will play an increasing role in human activities both on earth, in fields as diverse as human health and the industrial production of novel bio-composites. Beyond earth, we will rely increasingly on biologically-provided life support, as we have throughout our evolutionary history. In order to do this, the field will build on two of the great contributions of astrobiology: studies of the origin of life and life in extreme environments.

Microbiome-mediated bile acid modification: Role in intestinal drug absorption and metabolism.

Science.gov (United States)

Enright, Elaine F; Griffin, Brendan T; Gahan, Cormac G M; Joyce, Susan A

2018-04-13

Once regarded obscure and underappreciated, the gut microbiota (the microbial communities colonizing the gastrointestinal tract) is gaining recognition as an influencer of many aspects of human health. Also increasingly apparent is the breadth of interindividual variation in these co-evolved microbial-gut associations, presenting novel quests to explore implications for disease and therapeutic response. In this respect, the unearthing of the drug-metabolizing capacity of the microbiota has provided impetus for the integration of microbiological and pharmacological research. This review considers a potential mechanism, 'microbial bile acid metabolism', by which the intricate interplay between the host and gut bacteria may influence drug pharmacokinetics. Bile salts traditionally regarded as biological surfactants, synthesized by the host and biotransformed by gut bacteria, are now also recognized as signalling molecules that affect diverse physiological processes. Accumulating data indicate that bile salts are not equivalent with respect to their physicochemical properties, micellar solubilization capacities for poorly water-soluble drugs, crystallization inhibition tendencies nor potencies for bile acid receptor activation. Herein, the origin, physicochemical properties, physiological functions, plasticity and pharmaceutical significance of the human bile acid pool are discussed. Microbial dependant differences in the composition of the human bile acid pool, simulated intestinal media and commonly used preclinical species is highlighted to better understand in vivo performance predictiveness. While the precise impact of an altered gut microbiome, and consequently bile acid pool, in the biopharmaceutical setting remains largely elusive, the objective of this article is to aid knowledge acquisition through a detailed review of the literature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Behavioural equivalence for infinite systems - Partially decidable!

DEFF Research Database (Denmark)

Sunesen, Kim; Nielsen, Mogens

1996-01-01

languages with two generalizations based on traditional approaches capturing non-interleaving behaviour, pomsets representing global causal dependency, and locality representing spatial distribution of events. We first study equivalences on Basic Parallel Processes, BPP, a process calculus equivalent...... of processes between BPP and TCSP, not only are the two equivalences different, but one (locality) is decidable whereas the other (pomsets) is not. The decidability result for locality is proved by a reduction to the reachability problem for Petri nets....

Relations of equivalence of conditioned radioactive waste

International Nuclear Information System (INIS)

Kumer, L.; Szeless, A.; Oszuszky, F.

1982-01-01

A compensation for the wastes remaining with the operator of a waste management center, to be given by the agent having caused the waste, may be assured by effecting a financial valuation (equivalence) of wastes. Technically and logically, this equivalence between wastes (or specifically between different waste categories) and financial valuation has been established as reasonable. In this paper, the possibility of establishing such equivalences are developed, and their suitability for waste management concepts is quantitatively expressed

Equivalences of real submanifolds in complex space.

OpenAIRE

ZAITSEV, DMITRI

2001-01-01

PUBLISHED We show that for any real-analytic submanifold M in CN there is a proper real-analytic subvariety V contained in M such that for any p ? M \\ V , any real-analytic submanifold M? in CN, and any p? ? M?, the germs of the submanifolds M and M? at p and p? respectively are formally equivalent if and only if they are biholomorphically equivalent. More general results for k-equivalences are also stated and proved.

Fatty acid synthase - Modern tumor cell biology insights into a classical oncology target.

Science.gov (United States)

Buckley, Douglas; Duke, Gregory; Heuer, Timothy S; O'Farrell, Marie; Wagman, Allan S; McCulloch, William; Kemble, George

2017-09-01

Decades of preclinical and natural history studies have highlighted the potential of fatty acid synthase (FASN) as a bona fide drug target for oncology. This review will highlight the foundational concepts upon which this perspective is built. Published studies have shown that high levels of FASN in patient tumor tissues are present at later stages of disease and this overexpression predicts poor prognosis. Preclinical studies have shown that experimental overexpression of FASN in previously normal cells leads to changes that are critical for establishing a tumor phenotype. Once the tumor phenotype is established, FASN elicits several changes to the tumor cell and becomes intertwined with its survival. The product of FASN, palmitate, changes the biophysical nature of the tumor cell membrane; membrane microdomains enable the efficient assembly of signaling complexes required for continued tumor cell proliferation and survival. Membranes densely packed with phospholipids containing saturated fatty acids become resistant to the action of other chemotherapeutic agents. Inhibiting FASN leads to tumor cell death while sparing normal cells, which do not have the dependence of this enzyme for normal functions, and restores membrane architecture to more normal properties thereby resensitizing tumors to killing by chemotherapies. One compound has recently reached clinical studies in solid tumor patients and highlights the need for continued evaluation of the role of FASN in tumor cell biology. Significant advances have been made and much remains to be done to optimally apply this class of pharmacological agents for the treatment of specific cancers. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

A Cp-theory problem book functional equivalencies

CERN Document Server

Tkachuk, Vladimir V

2016-01-01

This fourth volume in Vladimir Tkachuk's series on Cp-theory gives reasonably complete coverage of the theory of functional equivalencies through 500 carefully selected problems and exercises. By systematically introducing each of the major topics of Cp-theory, the book is intended to bring a dedicated reader from basic topological principles to the frontiers of modern research. The book presents complete and up-to-date information on the preservation of topological properties by homeomorphisms of function spaces.  An exhaustive theory of t-equivalent, u-equivalent and l-equivalent spaces is developed from scratch.   The reader will also find introductions to the theory of uniform spaces, the theory of locally convex spaces, as well as  the theory of inverse systems and dimension theory. Moreover, the inclusion of Kolmogorov's solution of Hilbert's Problem 13 is included as it is needed for the presentation of the theory of l-equivalent spaces. This volume contains the most important classical re...

Equivalence relations for the 9972-9975 SARP

International Nuclear Information System (INIS)

Niemer, K.A.; Frost, R.L.

1994-10-01

Equivalence relations required to determine mass limits for mixtures of nuclides for the Safety Analysis Report for Packaging (SARP) of the Savannah River Site 9972, 9973, 9974, and 9975 shipping casks were calculated. The systems analyzed included aqueous spheres, homogeneous metal spheres, and metal ball-and-shell configurations, all surrounded by an effectively infinite stainless steel or water reflector. Comparison of the equivalence calculations with the rule-of-fractions showed conservative agreement for aqueous solutions, both conservative and non-conservative agreement for the metal homogeneous sphere systems, and non-conservative agreement for the majority of metal ball-and-shell systems. Equivalence factors for the aqueous solutions and homogeneous metal spheres were calculated. The equivalence factors for the non-conservative metal homogeneous sphere systems were adjusted so that they were conservative. No equivalence factors were calculated for the ball-and-shell systems since the -SARP assumes that only homogeneous or uniformly distributed material will be shipped in the 9972-9975 shipping casks, and an unnecessarily conservative critical mass may result if the ball-and-shell configurations are included

Equivalence of Szegedy's and coined quantum walks

Science.gov (United States)

Wong, Thomas G.

2017-09-01

Szegedy's quantum walk is a quantization of a classical random walk or Markov chain, where the walk occurs on the edges of the bipartite double cover of the original graph. To search, one can simply quantize a Markov chain with absorbing vertices. Recently, Santos proposed two alternative search algorithms that instead utilize the sign-flip oracle in Grover's algorithm rather than absorbing vertices. In this paper, we show that these two algorithms are exactly equivalent to two algorithms involving coined quantum walks, which are walks on the vertices of the original graph with an internal degree of freedom. The first scheme is equivalent to a coined quantum walk with one walk step per query of Grover's oracle, and the second is equivalent to a coined quantum walk with two walk steps per query of Grover's oracle. These equivalences lie outside the previously known equivalence of Szegedy's quantum walk with absorbing vertices and the coined quantum walk with the negative identity operator as the coin for marked vertices, whose precise relationships we also investigate.

7 CFR 1000.54 - Equivalent price.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Equivalent price. 1000.54 Section 1000.54 Agriculture... Prices § 1000.54 Equivalent price. If for any reason a price or pricing constituent required for computing the prices described in § 1000.50 is not available, the market administrator shall use a price or...

A Bayesian equivalency test for two independent binomial proportions.

Science.gov (United States)

Kawasaki, Yohei; Shimokawa, Asanao; Yamada, Hiroshi; Miyaoka, Etsuo

2016-01-01

In clinical trials, it is often necessary to perform an equivalence study. The equivalence study requires actively denoting equivalence between two different drugs or treatments. Since it is not possible to assert equivalence that is not rejected by a superiority test, statistical methods known as equivalency tests have been suggested. These methods for equivalency tests are based on the frequency framework; however, there are few such methods in the Bayesian framework. Hence, this article proposes a new index that suggests the equivalency of binomial proportions, which is constructed based on the Bayesian framework. In this study, we provide two methods for calculating the index and compare the probabilities that have been calculated by these two calculation methods. Moreover, we apply this index to the results of actual clinical trials to demonstrate the utility of the index.

The equivalence theorem

International Nuclear Information System (INIS)

Veltman, H.

1990-01-01

The equivalence theorem states that, at an energy E much larger than the vector-boson mass M, the leading order of the amplitude with longitudinally polarized vector bosons on mass shell is given by the amplitude in which these vector bosons are replaced by the corresponding Higgs ghosts. We prove the equivalence theorem and show its validity in every order in perturbation theory. We first derive the renormalized Ward identities by using the diagrammatic method. Only the Feynman-- 't Hooft gauge is discussed. The last step of the proof includes the power-counting method evaluated in the large-Higgs-boson-mass limit, needed to estimate the leading energy behavior of the amplitudes involved. We derive expressions for the amplitudes involving longitudinally polarized vector bosons for all orders in perturbation theory. The fermion mass has not been neglected and everything is evaluated in the region m f ∼M much-lt E much-lt m Higgs

Differential regulation of EGFR-MAPK signaling by deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA) in colon cancer.

Science.gov (United States)

Centuori, Sara M; Martinez, Jesse D

2014-10-01

A high-fat diet coincides with increased levels of bile acids. This increase in bile acids, particularly deoxycholic acid (DCA), has been strongly associated with the development of colon cancer. Conversely, ursodeoxycholic acid (UDCA) may have chemopreventive properties. Although structurally similar, DCA and UDCA present different biological and pathological effects in colon cancer progression. The differential regulation of cancer by these two bile acids is not yet fully understood. However, one possible explanation for their diverging effects is their ability to differentially regulate signaling pathways involved in the multistep progression of colon cancer, such as the epidermal growth factor receptor (EGFR)-mitogen-activated protein kinase (MAPK) pathway. This review will examine the biological effects of DCA and UDCA on colon cancer development, as well as the diverging effects of these bile acids on the oncogenic signaling pathways that play a role in colon cancer development, with a particular emphasis on bile acid regulation of the EGFR-MAPK pathway.

Molecular Structure of Nucleic Acids

Indian Academy of Sciences (India)

Molecular Structure of Nucleic Acids. A Structure for Deoxyribose Nucleic Acid. J. D. Watson and F. H. C. Crick. Medical Research Council Unit for the Study of the Molecular Structure of Biological. Systems, Cavendish Laboratory, Cambridge. April 2. We wish to suggest a structure for the salt of deoxyribose nucleic acid ...

Screening-level Biomonitoring Equivalents for tiered interpretation of urinary 3-phenoxybenzoic acid (3-PBA) in a risk assessment context.

Science.gov (United States)

Aylward, Lesa L; Irwin, Kim; St-Amand, Annie; Nong, Andy; Hays, Sean M

2018-02-01

3-Phenoxybenzoic acid (3-PBA) is a common metabolite of several pyrethroid pesticides of differing potency and also occurs as a residue in foods resulting from environmental degradation of parent pyrethroid compounds. Thus, 3-PBA in urine is not a specific biomarker of exposure to a particular pyrethroid. However, an approach derived from the use of Biomonitoring Equivalents (BEs) can be used to estimate a conservative initial screening value for a tiered assessment of population data on 3-PBA in urine. A conservative generic urinary excretion fraction for 3-PBA was estimated from data for five pyrethroid compounds with human data. Estimated steady-state urinary 3-PBA concentrations associated with reference doses and acceptable daily intakes for each of the nine compounds ranged from 1.7 μg/L for cyhalothrin and deltamethrin to 520 μg/L for permethrin. The lower value can be used as a highly conservative Tier 1 screening value for assessment of population urinary 3-PBA data. A second tier screening value of 87 μg/L was derived based on weighting by relative exposure estimates for the different pyrethroid compounds, to be applied as part of the data evaluation process if biomonitoring data exceed the Tier 1 value. These BE values are most appropriately used to evaluate the central tendency of population biomarker concentration data in a risk assessment context. The provisional BEs were compared to available national biomonitoring data from the US and Canada. Copyright © 2017. Published by Elsevier Inc.

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

Science.gov (United States)

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.

Chitin Extraction from Crustacean Shells Using Biological Methods – A Review

Directory of Open Access Journals (Sweden)

Wassila Arbia

2013-01-01

Full Text Available After cellulose, chitin is the most widespread biopolymer in nature. Chitin and its derivatives have great economic value because of their biological activities and their industrial and biomedical applications. It can be extracted from three sources, namely crustaceans, insects and microorganisms. However, the main commercial sources of chitin are shells of crustaceans such as shrimps, crabs, lobsters and krill that are supplied in large quantities by the shellfish processing industries. Extraction of chitin involves two steps, demineralisation and deproteinisation, which can be conducted by two methods, chemical or biological. The chemical method requires the use of acids and bases, while the biological method involves microorganisms. Although lactic acid bacteria are mainly applied, other microbial species including proteolytic bacteria have also been successfully implemented, as well as mixed cultures involving lactic acid-producing bacteria and proteolytic microorganisms. The produced lactic acid allows shell demineralisation, since lactic acid reacts with calcium carbonate, the main mineral component, to form calcium lactate.

Microbial Propionic Acid Production

Directory of Open Access Journals (Sweden)

R. Axayacatl Gonzalez-Garcia

2017-05-01

Full Text Available Propionic acid (propionate is a commercially valuable carboxylic acid produced through microbial fermentation. Propionic acid is mainly used in the food industry but has recently found applications in the cosmetic, plastics and pharmaceutical industries. Propionate can be produced via various metabolic pathways, which can be classified into three major groups: fermentative pathways, biosynthetic pathways, and amino acid catabolic pathways. The current review provides an in-depth description of the major metabolic routes for propionate production from an energy optimization perspective. Biological propionate production is limited by high downstream purification costs which can be addressed if the target yield, productivity and titre can be achieved. Genome shuffling combined with high throughput omics and metabolic engineering is providing new opportunities, and biological propionate production is likely to enter the market in the not so distant future. In order to realise the full potential of metabolic engineering and heterologous expression, however, a greater understanding of metabolic capabilities of the native producers, the fittest producers, is required.

Deoxyribonucleic acid-deficient strains of Candida albicans.

OpenAIRE

Olaiya, A F; Steed, J R; Sogin, S J

1980-01-01

We analyzed a series of germ tube-negative variants isolated from Candida albicans 3153A for deoxyribonucleic acid content. As analyzed by flow microfluorometry, the deoxyribonucleic acid level in these variant strains was 50% of that of the parental strain and equivalent to that of haploid Saccharomyces cerevisiae. This finding was confirmed by comparison of survival rates when exposed to the mutagens ultraviolet light, ethyl methane sulfonate, and methyl methane sulfonate. The diameter of t...

Synthesis and preliminary biological evaluations of (+)-isocampholenic acid-derived amides.

Science.gov (United States)

Grošelj, Uroš; Golobič, Amalija; Knez, Damijan; Hrast, Martina; Gobec, Stanislav; Ričko, Sebastijan; Svete, Jurij

2016-08-01

The synthesis of two novel (+)-isocampholenic acid-derived amines has been realized starting from commercially available (1S)-(+)-10-camphorsulfonic acid. The novel amines as well as (+)-isocampholenic acid have been used as building blocks in the construction of a library of amides using various aliphatic, aromatic, and amino acid-derived coupling partners using BPC and CDI as activating agents. Amide derivatives have been assayed against several enzymes that hold potential for the development of new drugs to battle bacterial infections and Alzheimer's disease. Compounds 20c and 20e showed promising selective sub-micromolar inhibition of human butyrylcholinesterase [Formula: see text] ([Formula: see text] values [Formula: see text] and [Formula: see text], respectively).

General Dynamic Equivalent Modeling of Microgrid Based on Physical Background

Directory of Open Access Journals (Sweden)

Changchun Cai

2015-11-01

Full Text Available Microgrid is a new power system concept consisting of small-scale distributed energy resources; storage devices and loads. It is necessary to employ a simplified model of microgrid in the simulation of a distribution network integrating large-scale microgrids. Based on the detailed model of the components, an equivalent model of microgrid is proposed in this paper. The equivalent model comprises two parts: namely, equivalent machine component and equivalent static component. Equivalent machine component describes the dynamics of synchronous generator, asynchronous wind turbine and induction motor, equivalent static component describes the dynamics of photovoltaic, storage and static load. The trajectory sensitivities of the equivalent model parameters with respect to the output variables are analyzed. The key parameters that play important roles in the dynamics of the output variables of the equivalent model are identified and included in further parameter estimation. Particle Swarm Optimization (PSO is improved for the parameter estimation of the equivalent model. Simulations are performed in different microgrid operation conditions to evaluate the effectiveness of the equivalent model of microgrid.

49 CFR 391.33 - Equivalent of road test.

Science.gov (United States)

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Equivalent of road test. 391.33 Section 391.33... AND LONGER COMBINATION VEHICLE (LCV) DRIVER INSTRUCTORS Tests § 391.33 Equivalent of road test. (a) In place of, and as equivalent to, the road test required by § 391.31, a person who seeks to drive a...

Foundations of gravitation theory: the principle of equivalence

International Nuclear Information System (INIS)

Haugan, M.P.

1978-01-01

A new framework is presented within which to discuss the principle of equivalence and its experimental tests. The framework incorporates a special structure imposed on the equivalence principle by the principle of energy conservation. This structure includes relations among the conceptual components of the equivalence principle as well as quantitative relations among the outcomes of its experimental tests. One of the most striking new results obtained through use of this framework is a connection between the breakdown of local Lorentz invariance and the breakdown of the principle that all bodies fall with the same acceleration in a gravitational field. An extensive discussion of experimental tests of the equivalence principle and their significance is also presented. Within the above framework, theory-independent analyses of a broad range of equivalence principle tests are possible. Gravitational redshift experiments. Doppler-shift experiments, the Turner-Hill and Hughes-Drever experiments, and a number of solar-system tests of gravitation theories are analyzed. Application of the techniques of theoretical nuclear physics to the quantitative interpretation of equivalence principle tests using laboratory materials of different composition yields a number of important results. It is found that current Eotvos experiments significantly demonstrate the compatibility of the weak interactions with the equivalence principle. It is also shown that the Hughes-Drever experiment is the most precise test of local Lorentz invariance yet performed. The work leads to a strong, tightly knit empirical basis for the principle of equivalence, the central pillar of the foundations of gravitation theory

Pharmacokinetics of Caffeic Acid from Methanol Seed Extract of ...

African Journals Online (AJOL)

Purpose: To describe caffeic acid-based pharmacokinetics of methanol extract of seed of Syzygium cumini L. in rats. Methods: A dose of the extract (500 mg, equivalent to 37.135 mg caffeic acid) was administered orally to 6 male Wister rats, weighing 200 ± 10 g. Blood samples (0.5 mL), collected from the tail vein at 0, 15, ...

Spaces of homotopy self-equivalences a survey

CERN Document Server

Rutter, John W

1997-01-01

This survey covers groups of homotopy self-equivalence classes of topological spaces, and the homotopy type of spaces of homotopy self-equivalences. For manifolds, the full group of equivalences and the mapping class group are compared, as are the corresponding spaces. Included are methods of calculation, numerous calculations, finite generation results, Whitehead torsion and other areas. Some 330 references are given. The book assumes familiarity with cell complexes, homology and homotopy. Graduate students and established researchers can use it for learning, for reference, and to determine the current state of knowledge.

Inhibitory effects of ascorbic acid, vitamin E, and vitamin B-complex on the biological activities induced by Bothrops venom.

Science.gov (United States)

Oliveira, Carlos Henrique de Moura; Assaid Simão, Anderson; Marcussi, Silvana

2016-01-01

Natural compounds have been widely studied with the aim of complementing antiophidic serum therapy. The present study evaluated the inhibitory potential of ascorbic acid and a vitamin complex, composed of ascorbic acid, vitamin E, and all the B-complex vitamins, on the biological activities induced by snake venoms. The effect of vitamins was evaluated on the phospholipase, proteolytic, coagulant, and fibrinogenolytic activities induced by Bothrops moojeni (Viperidae), B. jararacussu, and B. alternatus snake venoms, and the hemagglutinating activity induced by B. jararacussu venom. The vitamin complex (1:5 and 1:10 ratios) totally inhibited the fibrinogenolytic activity and partially the phospholipase activity and proteolytic activity on azocasein induced by the evaluated venoms. Significant inhibition was observed in the coagulation of human plasma induced by venoms from B. alternatus (1:2.5 and 1:5, to vitamin complex and ascorbic acid) and B. moojeni (1:2.5 and 1:5, to vitamin complex and ascorbic acid). Ascorbic acid inhibited 100% of the proteolytic activities of B. moojeni and B. alternatus on azocasein, at 1:10 ratio, the effects of all the venoms on fibrinogen, the hemagglutinating activity of B. jararacussu venom, and also extended the plasma coagulation time induced by all venoms analyzed. The vitamins analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms, suggesting their interaction with toxins belonging to the phospholipase A2, protease, and lectin classes. The results can aid further research in clarifying the possible mechanisms of interaction between vitamins and snake enzymes.

Equivalent nozzle in thermomechanical problems

International Nuclear Information System (INIS)

Cesari, F.

1977-01-01

When analyzing nuclear vessels, it is most important to study the behavior of the nozzle cylinder-cylinder intersection. For the elastic field, this analysis in three dimensions is quite easy using the method of finite elements. The same analysis in the non-linear field becomes difficult for designs in 3-D. It is therefore necessary to resolve a nozzle in two dimensions equivalent to a 3-D nozzle. The purpose of the present work is to find an equivalent nozzle both with a mechanical and thermal load. This has been achieved by the analysis in three dimensions of a nozzle and a nozzle cylinder-sphere intersection, of a different radius. The equivalent nozzle will be a nozzle with a sphere radius in a given ratio to the radius of a cylinder; thus, the maximum equivalent stress is the same in both 2-D and 3-D. The nozzle examined derived from the intersection of a cylindrical vessel of radius R=191.4 mm and thickness T=6.7 mm with a cylindrical nozzle of radius r=24.675 mm and thickness t=1.350 mm, for which the experimental results for an internal pressure load are known. The structure was subdivided into 96 finite, three-dimensional and isoparametric elements with 60 degrees of freedom and 661 total nodes. Both the analysis with a mechanical load as well as the analysis with a thermal load were carried out on this structure according to the Bersafe system. The thermal load consisted of a transient typical of an accident occurring in a sodium-cooled fast reactor, with a peak of the temperature (540 0 C) for the sodium inside the vessel with an insulating argon temperature constant at 525 0 C. The maximum value of the equivalent tension was found in the internal area at the union towards the vessel side. The analysis of the nozzle in 2-D consists in schematizing the structure as a cylinder-sphere intersection, where the sphere has a given relation to the

Biological evaluation of 99m Tc-N-(3-bromo-trimethyl-acetanilide)-iminodiacetic acid (99mTc mebrofenin) as hepatobiliary radiopharmaceutical

International Nuclear Information System (INIS)

Hamada, E.S.

1994-01-01

Technetium-99 m-N-(3-bromo-2,4,6-trimethyl acetanilide) iminodiacetic acid ( 99m Tc-Mebrofenin) has been described as having optimal properties as hepatobiliary radiopharmaceutical. This paper describes the synthesis, radiopharmaceutical preparation and biological distribution of new labeled compound. The biodistribution study of 99m Tc-Mebrofenin- was carried out in normal mice. The specificity for hepatobiliary excretion blood clearance and cumulative biliary excretion were evaluated in normal and cirrhotic rats. (author). 5 refs, 3 figs, 3 tabs

Evaluation of a commercial biologically based IMRT treatment planning system

International Nuclear Information System (INIS)

Semenenko, Vladimir A.; Reitz, Bodo; Day, Ellen; Qi, X. Sharon; Miften, Moyed; Li, X. Allen

2008-01-01

A new inverse treatment planning system (TPS) for external beam radiation therapy with high energy photons is commercially available that utilizes both dose-volume-based cost functions and a selection of cost functions which are based on biological models. The purpose of this work is to evaluate quality of intensity-modulated radiation therapy (IMRT) plans resulting from the use of biological cost functions in comparison to plans designed using a traditional TPS employing dose-volume-based optimization. Treatment planning was performed independently at two institutions. For six cancer patients, including head and neck (one case from each institution), prostate, brain, liver, and rectal cases, segmental multileaf collimator IMRT plans were designed using biological cost functions and compared with clinically used dose-based plans for the same patients. Dose-volume histograms and dosimetric indices, such as minimum, maximum, and mean dose, were extracted and compared between the two types of treatment plans. Comparisons of the generalized equivalent uniform dose (EUD), a previously proposed plan quality index (fEUD), target conformity and heterogeneity indices, and the number of segments and monitor units were also performed. The most prominent feature of the biologically based plans was better sparing of organs at risk (OARs). When all plans from both institutions were combined, the biologically based plans resulted in smaller EUD values for 26 out of 33 OARs by an average of 5.6 Gy (range 0.24 to 15 Gy). Owing to more efficient beam segmentation and leaf sequencing tools implemented in the biologically based TPS compared to the dose-based TPS, an estimated treatment delivery time was shorter in most (five out of six) cases with some plans showing up to 50% reduction. The biologically based plans were generally characterized by a smaller conformity index, but greater heterogeneity index compared to the dose-based plans. Overall, compared to plans based on dose

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Biological Conversion of Sugars to Hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Davis, R.; Tao, L.; Tan, E. C. D.; Biddy, M. J.; Beckham, G. T.; Scarlata, C.; Jacobson, J.; Cafferty, K.; Ross, J.; Lukas, J.; Knorr, D.; Schoen, P.

2013-10-01

This report describes one potential conversion process to hydrocarbon products by way of biological conversion of lingnocellulosic-dervied sugars. The process design converts biomass to a hydrocarbon intermediate, a free fatty acid, using dilute-acid pretreatement, enzymatic saccharification, and bioconversion. Ancillary areas--feed handling, hydrolysate conditioning, product recovery and upgrading (hydrotreating) to a final blendstock material, wastewater treatment, lignin combusion, and utilities--are also included in the design.

In Vitro Antioxidant-Activity Evaluation of Gallic-Acid-Grafted Chitosan Conjugate Synthesized by Free-Radical-Induced Grafting Method.

Science.gov (United States)

Hu, Qiaobin; Wang, Taoran; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

2016-07-27

The major objective of this work was to develop a green and facile process to prepare gallic acid-chitosan conjugate and comprehensively evaluate the physicochemical properties and biological activities of an as-prepared water-soluble chitosan derivative. A free-radical-induced grafting approach using an ascorbic acid-hydrogen peroxide redox pair was adopted. The obtained conjugate was characterized by Fourier transform infrared spectroscopy, UV-vis, X-ray diffraction, and pKa analysis. The antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6)-sulphonic acid (ABTS), reducing power, and oxygen-radical antioxidant-capacity assays. The results showed that the mass ratio of gallic acid to chitosan played a vital role in determining the grafting degree and ζ potential of the conjugates, with the ratio of 0.5:1 being the optimal ratio that resulted in the highest grafting degree. The antioxidant assays demonstrated that conjugation significantly improved the antioxidant activities, being dramatically higher than that of free chitosan. It was notable that the DPPH- and ABTS-scavenging activities of conjugate at 0.4 mg/mL reached the same level as the free gallic acid at the equivalent concentration. Our study demonstrated a green and facile synthesis approach to preparing a novel water-soluble chitosan derivative that may have promising potentials in the food industry.

Mathematical modeling of acid-base physiology.

Science.gov (United States)

Occhipinti, Rossana; Boron, Walter F

2015-01-01

pH is one of the most important parameters in life, influencing virtually every biological process at the cellular, tissue, and whole-body level. Thus, for cells, it is critical to regulate intracellular pH (pHi) and, for multicellular organisms, to regulate extracellular pH (pHo). pHi regulation depends on the opposing actions of plasma-membrane transporters that tend to increase pHi, and others that tend to decrease pHi. In addition, passive fluxes of uncharged species (e.g., CO2, NH3) and charged species (e.g., HCO3(-), [Formula: see text] ) perturb pHi. These movements not only influence one another, but also perturb the equilibria of a multitude of intracellular and extracellular buffers. Thus, even at the level of a single cell, perturbations in acid-base reactions, diffusion, and transport are so complex that it is impossible to understand them without a quantitative model. Here we summarize some mathematical models developed to shed light onto the complex interconnected events triggered by acids-base movements. We then describe a mathematical model of a spherical cells-which to our knowledge is the first one capable of handling a multitude of buffer reactions-that our team has recently developed to simulate changes in pHi and pHo caused by movements of acid-base equivalents across the plasma membrane of a Xenopus oocyte. Finally, we extend our work to a consideration of the effects of simultaneous CO2 and HCO3(-) influx into a cell, and envision how future models might extend to other cell types (e.g., erythrocytes) or tissues (e.g., renal proximal-tubule epithelium) important for whole-body pH homeostasis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optical Sensors for Detection of Amino Acids.

Science.gov (United States)

Pettiwala, Aafrin M; Singh, Prabhat K

2017-11-06

Amino acids are crucially involved in a myriad of biological processes. Any aberrant changes in physiological level of amino acids often manifest in common metabolic disorders, serious neurological conditions and cardiovascular diseases. Thus, devising methods for detection of trace amounts of amino acids becomes highly elemental to their efficient clinical diagnosis. Recently, the domain of developing optical sensors for detection of amino acids has witnessed significant activity which is the focus of the current review article. We undertook a detailed search of the peer-reviewed literature that primarily deals with optical sensors for amino acids and focuses on the use of different type of materials as a sensing platform. Ninety-five papers have been included in the review, majority of which deals with optical sensors. We attempt to systematically classify these contributions based on applications of various chemical and biological scaffolds such as polymers, supramolecular assemblies, nanoparticles, DNA, heparin etc. for the sensing of amino acids. This review identifies that supramolecular assemblies and nanomaterial continue to be commonly used materials to devise sensors for amino acids followed by surfactant assemblies. The broad implications of amino acids in human health and diagnosis have stirred a lot of interest to develop optimized optical detection systems for amino acids in recent years, using different materials based on chemical and biological scaffolds. We have also attempted to highlight the merits and demerits of some of the noteworthy sensor systems to instigate further efforts for constructing amino acids sensor based on unconventional concepts. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Quantum mechanics and the equivalence principle

International Nuclear Information System (INIS)

Davies, P C W

2004-01-01

A quantum particle moving in a gravitational field may penetrate the classically forbidden region of the gravitational potential. This raises the question of whether the time of flight of a quantum particle in a gravitational field might deviate systematically from that of a classical particle due to tunnelling delay, representing a violation of the weak equivalence principle. I investigate this using a model quantum clock to measure the time of flight of a quantum particle in a uniform gravitational field, and show that a violation of the equivalence principle does not occur when the measurement is made far from the turning point of the classical trajectory. The results are then confirmed using the so-called dwell time definition of quantum tunnelling. I conclude with some remarks about the strong equivalence principle in quantum mechanics

Treatment of bromoamine acid wastewater using combined process of micro-electrolysis and biological aerobic filter.

Science.gov (United States)

Fan, Li; Ni, Jinren; Wu, Yanjun; Zhang, Yongyong

2009-03-15

The wastewater originated from the production of bromoamine acid was treated in a sequential system of micro-electrolysis (ME) and biological aerobic filter (BAF). Decolorization and COD(Cr) removal rate of the proposed system was investigated with full consideration of the influence of two major controlling factors such as organic loading rate (OLR) and hydraulic retention time (HRT). The removal rate of COD(Cr) was 81.2% and that of chrominance could be up to 96.6% at an OLR of 0.56 kg m(-3)d(-1) when the total HRT was 43.4h. Most of the chrominance was removed by the ME treatment, however, the BAF process was more effective for COD(Cr) removal. The GC-MS and HPLC-MS analysis of the contaminants revealed that 1-aminoanthraquinone, bromoamine acid and mono-sulfonated 1,2-dichlorobenzene were the main organic components in the wastewater. The reductive transformation of the anthraquinone derivatives in the ME reactor improved the biodegradability of the wastewater, and rendered the decolorization. After long-term of operation, it was observed that the predominant microorganisms immobilized on the BAF carriers were rod-shaped and globular. Four bacterial strains with apparent 16S rDNA fragments in the Denaturing Gradient Gel Electrophoresis (DGGE) profiles of BAF samples were identified as Variovorax sp., Sphingomonas sp., Mycobacterium sp., and Microbacterium sp.

Treatment of bromoamine acid wastewater using combined process of micro-electrolysis and biological aerobic filter

Energy Technology Data Exchange (ETDEWEB)

Fan Li [Shenzhen Graduate School, Peking University, Key Laboratory for Environmental and Urban Sciences, Guang Dong 518055 (China); Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China); Ni Jinren [Shenzhen Graduate School, Peking University, Key Laboratory for Environmental and Urban Sciences, Guang Dong 518055 (China); Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)], E-mail: nijinren@iee.pku.edu.cn; Wu Yanjun; Zhang Yongyong [Shenzhen Graduate School, Peking University, Key Laboratory for Environmental and Urban Sciences, Guang Dong 518055 (China); Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)

2009-03-15

The wastewater originated from the production of bromoamine acid was treated in a sequential system of micro-electrolysis (ME) and biological aerobic filter (BAF). Decolorization and COD{sub Cr} removal rate of the proposed system was investigated with full consideration of the influence of two major controlling factors such as organic loading rate (OLR) and hydraulic retention time (HRT). The removal rate of COD{sub Cr} was 81.2% and that of chrominance could be up to 96.6% at an OLR of 0.56 kg m{sup -3} d{sup -1} when the total HRT was 43.4 h. Most of the chrominance was removed by the ME treatment, however, the BAF process was more effective for COD{sub Cr} removal. The GC-MS and HPLC-MS analysis of the contaminants revealed that 1-aminoanthraquinone, bromoamine acid and mono-sulfonated 1,2-dichlorobenzene were the main organic components in the wastewater. The reductive transformation of the anthraquinone derivatives in the ME reactor improved the biodegradability of the wastewater, and rendered the decolorization. After long-term of operation, it was observed that the predominant microorganisms immobilized on the BAF carriers were rod-shaped and globular. Four bacterial strains with apparent 16S rDNA fragments in the Denaturing Gradient Gel Electrophoresis (DGGE) profiles of BAF samples were identified as Variovorax sp., Sphingomonas sp., Mycobacterium sp., and Microbacterium sp.

Treatment of bromoamine acid wastewater using combined process of micro-electrolysis and biological aerobic filter

International Nuclear Information System (INIS)

Fan Li; Ni Jinren; Wu Yanjun; Zhang Yongyong

2009-01-01

The wastewater originated from the production of bromoamine acid was treated in a sequential system of micro-electrolysis (ME) and biological aerobic filter (BAF). Decolorization and COD Cr removal rate of the proposed system was investigated with full consideration of the influence of two major controlling factors such as organic loading rate (OLR) and hydraulic retention time (HRT). The removal rate of COD Cr was 81.2% and that of chrominance could be up to 96.6% at an OLR of 0.56 kg m -3 d -1 when the total HRT was 43.4 h. Most of the chrominance was removed by the ME treatment, however, the BAF process was more effective for COD Cr removal. The GC-MS and HPLC-MS analysis of the contaminants revealed that 1-aminoanthraquinone, bromoamine acid and mono-sulfonated 1,2-dichlorobenzene were the main organic components in the wastewater. The reductive transformation of the anthraquinone derivatives in the ME reactor improved the biodegradability of the wastewater, and rendered the decolorization. After long-term of operation, it was observed that the predominant microorganisms immobilized on the BAF carriers were rod-shaped and globular. Four bacterial strains with apparent 16S rDNA fragments in the Denaturing Gradient Gel Electrophoresis (DGGE) profiles of BAF samples were identified as Variovorax sp., Sphingomonas sp., Mycobacterium sp., and Microbacterium sp

Omega-3 Fatty Acids and Depression: Scientific Evidence and Biological Mechanisms

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Giuseppe Grosso

2014-01-01

Full Text Available The changing of omega-6/omega-3 polyunsaturated fatty acids (PUFA in the food supply of Western societies occurred over the last 150 years is thought to promote the pathogenesis of many inflammatory-related diseases, including depressive disorders. Several epidemiological studies reported a significant inverse correlation between intake of oily fish and depression or bipolar disorders. Studies conducted specifically on the association between omega-3 intake and depression reported contrasting results, suggesting that the preventive role of omega-3 PUFA may depend also on other factors, such as overall diet quality and the social environment. Accordingly, tertiary prevention with omega-3 PUFA supplement in depressed patients has reached greater effectiveness during the last recent years, although definitive statements on their use in depression therapy cannot be yet freely asserted. Among the biological properties of omega-3 PUFA, their anti-inflammatory effects and their important role on the structural changing of the brain should be taken into account to better understand the possible pathway through which they can be effective both in preventing or treating depression. However, the problem of how to correct the inadequate supply of omega-3 PUFA in the Westernized countries’ diet is a priority in order to set food and health policies and also dietary recommendations for individuals and population groups.

Equivalency of two-dimensional algebras

International Nuclear Information System (INIS)

Santos, Gildemar Carneiro dos; Pomponet Filho, Balbino Jose S.

2011-01-01

Full text: Let us consider a vector z = xi + yj over the field of real numbers, whose basis (i,j) satisfy a given algebra. Any property of this algebra will be reflected in any function of z, so we can state that the knowledge of the properties of an algebra leads to more general conclusions than the knowledge of the properties of a function. However structural properties of an algebra do not change when this algebra suffers a linear transformation, though the structural constants defining this algebra do change. We say that two algebras are equivalent to each other whenever they are related by a linear transformation. In this case, we have found that some relations between the structural constants are sufficient to recognize whether or not an algebra is equivalent to another. In spite that the basis transform linearly, the structural constants change like a third order tensor, but some combinations of these tensors result in a linear transformation, allowing to write the entries of the transformation matrix as function of the structural constants. Eventually, a systematic way to find the transformation matrix between these equivalent algebras is obtained. In this sense, we have performed the thorough classification of associative commutative two-dimensional algebras, and find that even non-division algebra may be helpful in solving non-linear dynamic systems. The Mandelbrot set was used to have a pictorial view of each algebra, since equivalent algebras result in the same pattern. Presently we have succeeded in classifying some non-associative two-dimensional algebras, a task more difficult than for associative one. (author)

Investigation of nutrient feeding strategies in a countercurrent mixed-acid multi-staged fermentation: experimental data.

Science.gov (United States)

Smith, Aaron Douglas; Lockman, Nur Ain; Holtzapple, Mark T

2011-06-01

Nutrients are essential for microbial growth and metabolism in mixed-culture acid fermentations. Understanding the influence of nutrient feeding strategies on fermentation performance is necessary for optimization. For a four-bottle fermentation train, five nutrient contacting patterns (single-point nutrient addition to fermentors F1, F2, F3, and F4 and multi-point parallel addition) were investigated. Compared to the traditional nutrient contacting method (all nutrients fed to F1), the near-optimal feeding strategies improved exit yield, culture yield, process yield, exit acetate-equivalent yield, conversion, and total acid productivity by approximately 31%, 39%, 46%, 31%, 100%, and 19%, respectively. There was no statistical improvement in total acid concentration. The traditional nutrient feeding strategy had the highest selectivity and acetate-equivalent selectivity. Total acid productivity depends on carbon-nitrogen ratio.

Attainment of radiation equivalency principle

International Nuclear Information System (INIS)

Shmelev, A.N.; Apseh, V.A.

2004-01-01

Problems connected with the prospects for long-term development of the nuclear energetics are discussed. Basic principles of the future large-scale nuclear energetics are listed, primary attention is the safety of radioactive waste management of nuclear energetics. The radiation equivalence principle means close of fuel cycle and management of nuclear materials transportation with low losses on spent fuel and waste processing. Two aspects are considered: radiation equivalence in global and local aspects. The necessity of looking for other strategies of fuel cycle management in full-scale nuclear energy on radioactive waste management is supported [ru

Towards physical principles of biological evolution

Science.gov (United States)

Katsnelson, Mikhail I.; Wolf, Yuri I.; Koonin, Eugene V.

2018-03-01

Biological systems reach organizational complexity that far exceeds the complexity of any known inanimate objects. Biological entities undoubtedly obey the laws of quantum physics and statistical mechanics. However, is modern physics sufficient to adequately describe, model and explain the evolution of biological complexity? Detailed parallels have been drawn between statistical thermodynamics and the population-genetic theory of biological evolution. Based on these parallels, we outline new perspectives on biological innovation and major transitions in evolution, and introduce a biological equivalent of thermodynamic potential that reflects the innovation propensity of an evolving population. Deep analogies have been suggested to also exist between the properties of biological entities and processes, and those of frustrated states in physics, such as glasses. Such systems are characterized by frustration whereby local state with minimal free energy conflict with the global minimum, resulting in ‘emergent phenomena’. We extend such analogies by examining frustration-type phenomena, such as conflicts between different levels of selection, in biological evolution. These frustration effects appear to drive the evolution of biological complexity. We further address evolution in multidimensional fitness landscapes from the point of view of percolation theory and suggest that percolation at level above the critical threshold dictates the tree-like evolution of complex organisms. Taken together, these multiple connections between fundamental processes in physics and biology imply that construction of a meaningful physical theory of biological evolution might not be a futile effort. However, it is unrealistic to expect that such a theory can be created in one scoop; if it ever comes to being, this can only happen through integration of multiple physical models of evolutionary processes. Furthermore, the existing framework of theoretical physics is unlikely to suffice

Biological roles and therapeutic potential of hydroxy-carboxylic acid receptors

Directory of Open Access Journals (Sweden)

Kashan eAhmed

2011-10-01

Full Text Available In the recent past, deorphanization studies have described intermediates of energy metabolism to activate G protein-coupled receptors (GPCRs and to thereby regulate metabolic functions. GPR81, GPR109A and GPR109B, formerly known as the nicotinic acid receptor family, are encoded by clustered genes and share a high degree of sequence homology. Recently, hydroxy-carboxylic acids were identified as endogenous ligands of GPR81, GPR109A and GPR109B, and therefore these receptors have been placed into a novel receptor family of hydroxy-carboxylic acid (HCA receptors. The HCA1 receptor (GPR81 is activated by the glycolytic metabolite 2-hydroxy-propionic acid (lactate, the HCA2 receptor is activated by the ketone body 3-hydroxy-butyric acid and the HCA3 receptor (GPR109B is a receptor for the β-oxidation intermediate 3-hydroxy-octanoic acid. While HCA1 and HCA2 receptors are present in most mammalian species, the HCA3 receptor is exclusively found in humans and higher primates. HCA receptors are expressed in adipose tissue and mediate anti-lipolytic effects in adipocytes through Gi-type G-protein-dependent inhibition of adenylyl cyclase. HCA2 and HCA3 inhibit lipolysis during conditions of increased β-oxidation such as prolonged fasting, whereas HCA1 mediates the anti-lipolytic effects of insulin in the fed state. As HCA2 is a receptor for the established anti-dyslipidemic drug nicotinic acid, HCA1 and HCA3 also represent promising drug targets and several synthetic ligands for HCA receptors have been developed. In this article, we will summarize the deorphanization and pharmacological characterization of HCA receptors. Moreover, we will discuss recent progress in elucidating the physiological and pathophysiological role to further evaluate the therapeutic potential of the HCA receptor family for the treatment of metabolic disease.

Probing the potential of neutron imaging for biomedical and biological applications

International Nuclear Information System (INIS)

Watkin, Kenneth L.; Bilheux, Hassina Z.; Ankner, John Francis

2009-01-01

Neutron imaging of biological specimens began soon after the discovery of the neutron by Chadwick in 1932. The first samples included tumors in tissues, internal organs in rats, and bones. These studies mainly employed thermal neutrons and were often compared with X-ray images of the same or equivalent samples. Although neutron scattering is widely used in biological studies, neutron imaging has yet to be exploited to its full capability in this area. This chapter summarizes past and current research efforts to apply neutron radiography to the study of biological specimens, in the expectation that clinical and medical research, as well as forensic science, may benefit from it.

Synthesis and Biological Activity of Novel Amino Acid-(N'-Benzoyl Hydrazide and Amino Acid-(N'-Nicotinoyl Hydrazide Derivatives

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Sherine N. Khattab

2005-09-01

Full Text Available The coupling reaction of benzoic acid and nicotinic acid hydrazides with N- protected L-amino acids including valine, leucine, phenylalanine, glutamic acid and tyrosine is reported. The target compounds, N-Boc-amino acid-(N`-benzoyl- and N- Boc-amino acid-(N`-nicotinoyl hydrazides 5a-5e and 6a-6e were prepared in very high yields and purity using N-[(dimethylamino-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl- methylene]-N-methyl-methanaminium hexafluorophosphate N-oxide (HATU as coupling reagent. The antimicrobial activity of the Cu and Cd complexes of the designed compounds was tested. The products were deprotected affording the corresponding amino acid-(N`-benzoyl hydrazide hydrochloride salts (7a-7e and amino acid-(N`- nicotinoyl hydrazide hydrochloride salts (8a-8e. These compounds and their Cu and Cd complexes were also tested for their antimicrobial activity. Several compounds showed comparable activity to that of ampicillin against S. aureus and E. coli.

[Folic acid in physiology and pathology].

Science.gov (United States)

Czeczot, Hanna

2008-08-13

This paper presents current knowledge of the biological functions of folic acid, the effects of its deficiency in the organism, as well as the possibilities of its therapeutic use. Folic acid (folate, B9) is a vitamin of special importance in normal cellular functions. Tetrahydrofolate (TH4-folate) is the biologically active form of folic acid. The main role of folic acid in biochemistry is the single-carbon transfer reaction (e.g. transfer of a methyl, methylene, or formyl group). Folic acid is involved in the transformation of certain amino acids as well as in the synthesis of purines and dTMP (2'-deoxythymidine-5'-phosphate) needed for the synthesis of nucleic acid (DNA), required by all rapidly growing cells. In humans, folate deficiency results in serious pathologies, the most important of which are neural tube defects, megablastic anemia, acceleration of the arteriosclerotic process, changes in the central nervous system, and the development of certain types of cancer. To increase the intake of folic acid, preventive actions include dietary education, the main objectives of which are to increase the intake of natural folate in the daily diet, add folic acid to selected dietary products (e.g. fl our, pasta, rice), and encourage supplementation with folic acid-containing pharmaceuticals.

Succinic Acid: Technology Development and Commercialization

Directory of Open Access Journals (Sweden)

Nhuan P. Nghiem

2017-06-01

Full Text Available Succinic acid is a precursor of many important, large-volume industrial chemicals and consumer products. It was once common knowledge that many ruminant microorganisms accumulated succinic acid under anaerobic conditions. However, it was not until the discovery of Anaerobiospirillum succiniciproducens at the Michigan Biotechnology Institute (MBI, which was capable of producing succinic acid up to about 50 g/L under optimum conditions, that the commercial feasibility of producing the compound by biological processes was realized. Other microbial strains capable of producing succinic acid to high final concentrations subsequently were isolated and engineered, followed by development of fermentation processes for their uses. Processes for recovery and purification of succinic acid from fermentation broths were simultaneously established along with new applications of succinic acid, e.g., production of biodegradable deicing compounds and solvents. Several technologies for the fermentation-based production of succinic acid and the subsequent conversion to useful products are currently commercialized. This review gives a summary of the development of microbial strains, their fermentation, and the importance of the down-stream recovery and purification efforts to suit various applications in the context of their current commercialization status for biologically derived succinic acid.

Production of Fatty Acid-Derived Valuable Chemicals in Synthetic Microbes

International Nuclear Information System (INIS)

Yu, Ai-Qun; Pratomo Juwono, Nina Kurniasih; Leong, Susanna Su Jan; Chang, Matthew Wook

2014-01-01

Fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. Currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. Metabolic engineering of microorganisms has provided a platform for effective production of these valuable biochemicals. Notably, synthetic biology-based metabolic engineering strategies have been extensively applied to refactor microorganisms for improved biochemical production. Here, we reviewed: (i) the current status of metabolic engineering of microbes that produce fatty acid-derived valuable chemicals, and (ii) the recent progress of synthetic biology approaches that assist metabolic engineering, such as mRNA secondary structure engineering, sensor-regulator system, regulatable expression system, ultrasensitive input/output control system, and computer science-based design of complex gene circuits. Furthermore, key challenges and strategies were discussed. Finally, we concluded that synthetic biology provides useful metabolic engineering strategies for economically viable production of fatty acid-derived valuable chemicals in engineered microbes.

Production of Fatty Acid-Derived Valuable Chemicals in Synthetic Microbes

Energy Technology Data Exchange (ETDEWEB)

Yu, Ai-Qun; Pratomo Juwono, Nina Kurniasih [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore); Leong, Susanna Su Jan [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore); Singapore Institute of Technology, Singapore (Singapore); Chang, Matthew Wook, E-mail: bchcmw@nus.edu.sg [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore)

2014-12-23

Fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. Currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. Metabolic engineering of microorganisms has provided a platform for effective production of these valuable biochemicals. Notably, synthetic biology-based metabolic engineering strategies have been extensively applied to refactor microorganisms for improved biochemical production. Here, we reviewed: (i) the current status of metabolic engineering of microbes that produce fatty acid-derived valuable chemicals, and (ii) the recent progress of synthetic biology approaches that assist metabolic engineering, such as mRNA secondary structure engineering, sensor-regulator system, regulatable expression system, ultrasensitive input/output control system, and computer science-based design of complex gene circuits. Furthermore, key challenges and strategies were discussed. Finally, we concluded that synthetic biology provides useful metabolic engineering strategies for economically viable production of fatty acid-derived valuable chemicals in engineered microbes.

Superstring field theory equivalence: Ramond sector

International Nuclear Information System (INIS)

Kroyter, Michael

2009-01-01

We prove that the finite gauge transformation of the Ramond sector of the modified cubic superstring field theory is ill-defined due to collisions of picture changing operators. Despite this problem we study to what extent could a bijective classical correspondence between this theory and the (presumably consistent) non-polynomial theory exist. We find that the classical equivalence between these two theories can almost be extended to the Ramond sector: We construct mappings between the string fields (NS and Ramond, including Chan-Paton factors and the various GSO sectors) of the two theories that send solutions to solutions in a way that respects the linearized gauge symmetries in both sides and keeps the action of the solutions invariant. The perturbative spectrum around equivalent solutions is also isomorphic. The problem with the cubic theory implies that the correspondence of the linearized gauge symmetries cannot be extended to a correspondence of the finite gauge symmetries. Hence, our equivalence is only formal, since it relates a consistent theory to an inconsistent one. Nonetheless, we believe that the fact that the equivalence formally works suggests that a consistent modification of the cubic theory exists. We construct a theory that can be considered as a first step towards a consistent RNS cubic theory.

Molecular biology: Self-sustaining chemistry

Directory of Open Access Journals (Sweden)

Wrede Paul

2007-10-01

Full Text Available Abstract Molecular biology is an established interdisciplinary field within biology that deals fundamentally with the function of any nucleic acid in the cellular context. The molecular biology section in Chemistry Central Journal focusses on the genetically determined chemistry and biochemistry occuring in the cell. How can thousands of chemical reactions interact smoothly to maintain the life of cells, even in a variable environment? How is this self-sustaining system achieved? These are questions that should be answered in the light of molecular biology and evolution, but with the application of biophysical, physico-chemical, analytical and preparative technologies. As the Section Editor for the molecular biology section in Chemistry Central Journal, I hope to receive manuscripts that present new approaches aimed at better answering and shedding light upon these fascinating questions related to the chemistry of livings cells.

Total phenolics and total flavonoids in selected Indian medicinal plants.

Science.gov (United States)

Sulaiman, C T; Balachandran, Indira

2012-05-01

Plant phenolics and flavonoids have a powerful biological activity, which outlines the necessity of their determination. The phenolics and flavonoids content of 20 medicinal plants were determined in the present investigation. The phenolic content was determined by using Folin-Ciocalteu assay. The total flavonoids were measured spectrophotometrically by using the aluminium chloride colorimetric assay. The results showed that the family Mimosaceae is the richest source of phenolics, (Acacia nilotica: 80.63 mg gallic acid equivalents, Acacia catechu 78.12 mg gallic acid equivalents, Albizia lebbeck 66.23 mg gallic acid equivalents). The highest total flavonoid content was revealed in Senna tora which belongs to the family Caesalpiniaceae. The present study also shows the ratio of flavonoids to the phenolics in each sample for their specificity.

Equivalent drawbead performance in deep drawing simulations

NARCIS (Netherlands)

Meinders, Vincent T.; Geijselaers, Hubertus J.M.; Huetink, Han

1999-01-01

Drawbeads are applied in the deep drawing process to improve the control of the material flow during the forming operation. In simulations of the deep drawing process these drawbeads can be replaced by an equivalent drawbead model. In this paper the usage of an equivalent drawbead model in the

The Pattern of Fatty Acids Displaced by EPA and DHA Following 12 Months Supplementation Varies between Blood Cell and Plasma Fractions

Directory of Open Access Journals (Sweden)

Celia G. Walker

2015-08-01

Full Text Available Eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA are increased in plasma lipids and blood cell membranes in response to supplementation. Whilst arachidonic acid (AA is correspondingly decreased, the effect on other fatty acids (FA is less well described and there may be site-specific differences. In response to 12 months EPA + DHA supplementation in doses equivalent to 0–4 portions of oily fish/week (1 portion: 3.27 g EPA+DHA multinomial regression analysis was used to identify important FA changes for plasma phosphatidylcholine (PC, cholesteryl ester (CE and triglyceride (TAG and for blood mononuclear cells (MNC, red blood cells (RBC and platelets (PLAT. Dose-dependent increases in EPA + DHA were matched by decreases in several n-6 polyunsaturated fatty acids (PUFA in PC, CE, RBC and PLAT, but were predominantly compensated for by oleic acid in TAG. Changes were observed for all FA classes in MNC. Consequently the n-6:n-3 PUFA ratio was reduced in a dose-dependent manner in all pools after 12 months (37%–64% of placebo in the four portions group. We conclude that the profile of the FA decreased in exchange for the increase in EPA + DHA following supplementation differs by FA pool with implications for understanding the impact of n-3 PUFA on blood lipid and blood cell biology.

The Pattern of Fatty Acids Displaced by EPA and DHA Following 12 Months Supplementation Varies between Blood Cell and Plasma Fractions.

Science.gov (United States)

Walker, Celia G; West, Annette L; Browning, Lucy M; Madden, Jackie; Gambell, Joanna M; Jebb, Susan A; Calder, Philip C

2015-08-03

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are increased in plasma lipids and blood cell membranes in response to supplementation. Whilst arachidonic acid (AA) is correspondingly decreased, the effect on other fatty acids (FA) is less well described and there may be site-specific differences. In response to 12 months EPA + DHA supplementation in doses equivalent to 0-4 portions of oily fish/week (1 portion: 3.27 g EPA+DHA) multinomial regression analysis was used to identify important FA changes for plasma phosphatidylcholine (PC), cholesteryl ester (CE) and triglyceride (TAG) and for blood mononuclear cells (MNC), red blood cells (RBC) and platelets (PLAT). Dose-dependent increases in EPA + DHA were matched by decreases in several n-6 polyunsaturated fatty acids (PUFA) in PC, CE, RBC and PLAT, but were predominantly compensated for by oleic acid in TAG. Changes were observed for all FA classes in MNC. Consequently the n-6:n-3 PUFA ratio was reduced in a dose-dependent manner in all pools after 12 months (37%-64% of placebo in the four portions group). We conclude that the profile of the FA decreased in exchange for the increase in EPA + DHA following supplementation differs by FA pool with implications for understanding the impact of n-3 PUFA on blood lipid and blood cell biology.

S-equivalents lagrangians in generalized mechanics

International Nuclear Information System (INIS)

Negri, L.J.; Silva, Edna G. da.

1985-01-01

The problem of s-equivalent lagrangians is considered in the realm of generalized mechanics. Some results corresponding to the ordinary (non-generalized) mechanics are extended to the generalized case. A theorem for the reduction of the higher order lagrangian description to the usual order is found to be useful for the analysis of generalized mechanical systems and leads to a new class of equivalence between lagrangian functions. Some new perspectives are pointed out. (Author) [pt

Dynamic equivalence relation on the fuzzy measure algebras

Directory of Open Access Journals (Sweden)

Roya Ghasemkhani

2017-04-01

Full Text Available The main goal of the present paper is to extend classical results from the measure theory and dynamical systems to the fuzzy subset setting. In this paper, the notion of  dynamic equivalence relation is introduced and then it is proved that this relation is an equivalence relation. Also, a new metric on the collection of all equivalence classes is introduced and it is proved that this metric is complete.

Cork-based activated carbons as supported adsorbent materials for trace level analysis of ibuprofen and clofibric acid in environmental and biological matrices.

Science.gov (United States)

Neng, N R; Mestre, A S; Carvalho, A P; Nogueira, J M F

2011-09-16

In this contribution, powdered activated carbons (ACs) from cork waste were supported for bar adsorptive micro-extraction (BAμE), as novel adsorbent phases for the analysis of polar compounds. By combining this approach with liquid desorption followed by high performance liquid chromatography with diode array detection (BAμE(AC)-LD/HPLC-DAD), good analytical performance was achieved using clofibric acid (CLOF) and ibuprofen (IBU) model compounds in environmental and biological matrices. Assays performed on 30 mL water samples spiked at the 25.0 μg L(-1) level yielded recoveries around 80% for CLOF and 95% for IBU, under optimized experimental conditions. The ACs textural and surface chemistry properties were correlated with the results obtained. The analytical performance showed good precision (0.9922) from 1.0 to 600.0 μg L(-1). By using the standard addition methodology, the application of the present approach to environmental water and urine matrices allowed remarkable performance at the trace level. The proposed methodology proved to be a viable alternative for acidic pharmaceuticals analysis, showing to be easy to implement, reliable, sensitive and requiring low sample volume to monitor these priority compounds in environmental and biological matrices. Copyright © 2011 Elsevier B.V. All rights reserved.

Development of a LC-MS/MS Method for the Simultaneous Detection of Tricarboxylic Acid Cycle Intermediates in a Range of Biological Matrices

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Omar Al Kadhi

2017-01-01

Full Text Available It is now well-established that perturbations in the tricarboxylic acid (TCA cycle play an important role in the metabolic transformation occurring in cancer including that of the prostate. A method for simultaneous qualitative and quantitative analysis of TCA cycle intermediates in body fluids, tissues, and cultured cell lines of human origin was developed using a common C18 reversed-phase column by LC-MS/MS technique. This LC-MS/MS method for profiling TCA cycle intermediates offers significant advantages including simple and fast preparation of a wide range of human biological samples. The analytical method was validated according to the guideline of the Royal Society of Chemistry Analytical Methods Committee. The limits of detection were below 60 nM for most of the TCA intermediates with the exception of lactic and fumaric acids. The calibration curves of all TCA analytes showed linearity with correlation coefficients r2>0.9998. Recoveries were >95% for all TCA analytes. This method was established taking into consideration problems and limitations of existing techniques. We envisage that its application to different biological matrices will facilitate deeper understanding of the metabolic changes in the TCA cycle from in vitro, ex vivo, and in vivo studies.

Construction of a self-supporting tissue-equivalent dividing wall and operational characteristics of a coaxial double-cylindrical tissue-equivalent proportional counter

International Nuclear Information System (INIS)

Saion, E.B.; Watt, D.E.

1994-01-01

An additional feature incorporated in a coaxial double-cylindrical tissue-equivalent proportional counter, is the presence of a common tissue-equivalent dividing wall between the inner and outer counters of thickness equivalent to the corresponding maximum range of protons at the energy of interest. By appropriate use of an anti-coincidence arrangement with the outer counter, the inner counter could be used to discriminate microdosimetric spectra of neutrons at the desired low energy range from those of the faster neutrons. The construction of an A-150 self-supporting tissue-equivalent dividing wall and an anti-coincidence unit are described. Some operational characteristic tests have been performed to determine the operation of the new microdosimeter. (author)

Geometry of the local equivalence of states

Energy Technology Data Exchange (ETDEWEB)

Sawicki, A; Kus, M, E-mail: assawi@cft.edu.pl, E-mail: marek.kus@cft.edu.pl [Center for Theoretical Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warszawa (Poland)

2011-12-09

We present a description of locally equivalent states in terms of symplectic geometry. Using the moment map between local orbits in the space of states and coadjoint orbits of the local unitary group, we reduce the problem of local unitary equivalence to an easy part consisting of identifying the proper coadjoint orbit and a harder problem of the geometry of fibers of the moment map. We give a detailed analysis of the properties of orbits of 'equally entangled states'. In particular, we show connections between certain symplectic properties of orbits such as their isotropy and coisotropy with effective criteria of local unitary equivalence. (paper)

Fatty acids, phenols content, and antioxidant activity in Ibervillea sonorae callus cultures

OpenAIRE

Estrada-Zúñiga, M.E.; Arano-Varela, H.; Buendía-González, L.; Orozco-Villafuerte, J.

2012-01-01

Ibervillea sonorae callus cultures were established in order to produce fatty acids (lauric, myristic, pentadecanoic, palmitic and stearic acids) and phenolic compounds. Highest callus induction (100%) was obtained in treatments containing 2.32 or 4.65 μM Kinetin (KIN) with 2.26 or 6.80 μM 2,4-Dichlorophenoxyacetic acid (2,4-D). Highest fatty acids (FA) production (48.57 mg g-1), highest total phenol content (TPC; 57.1 mg gallic acid equivalents [GAE] g-1) and highest antioxidant activity (EC...

Using synthetic biology to make cells tomorrow's test tubes.

Science.gov (United States)

Garcia, Hernan G; Brewster, Robert C; Phillips, Rob

2016-04-18

The main tenet of physical biology is that biological phenomena can be subject to the same quantitative and predictive understanding that physics has afforded in the context of inanimate matter. However, the inherent complexity of many of these biological processes often leads to the derivation of complex theoretical descriptions containing a plethora of unknown parameters. Such complex descriptions pose a conceptual challenge to the establishment of a solid basis for predictive biology. In this article, we present various exciting examples of how synthetic biology can be used to simplify biological systems and distill these phenomena down to their essential features as a means to enable their theoretical description. Here, synthetic biology goes beyond previous efforts to engineer nature and becomes a tool to bend nature to understand it. We discuss various recent and classic experiments featuring applications of this synthetic approach to the elucidation of problems ranging from bacteriophage infection, to transcriptional regulation in bacteria and in developing embryos, to evolution. In all of these examples, synthetic biology provides the opportunity to turn cells into the equivalent of a test tube, where biological phenomena can be reconstituted and our theoretical understanding put to test with the same ease that these same phenomena can be studied in the in vitro setting.

Comparison of amino acid oxidation and urea metabolism in haemodialysis patients during fasting and meal intake

NARCIS (Netherlands)

Veeneman, JM; Kingma, HA; Stellaard, F; de Jong, PE; Reijngoud, DJ; Huisman, RM

Background. The PNA (protein equivalent of nitrogen appearance) is used to calculate protein intake from urea kinetics. One of the essential assumptions in the calculation of PNA is that urea accumulation in haemodialysis (HD) patients is equivalent to amino acid oxidation. However, urea is

Gyrokinetic equivalence

International Nuclear Information System (INIS)

Parra, Felix I; Catto, Peter J

2009-01-01

We compare two different derivations of the gyrokinetic equation: the Hamiltonian approach in Dubin D H E et al (1983 Phys. Fluids 26 3524) and the recursive methodology in Parra F I and Catto P J (2008 Plasma Phys. Control. Fusion 50 065014). We prove that both approaches yield the same result at least to second order in a Larmor radius over macroscopic length expansion. There are subtle differences in the definitions of some of the functions that need to be taken into account to prove the equivalence.

Thévenin equivalent based static contingency assessment

DEFF Research Database (Denmark)

2015-01-01

of the determined present state of the power system and determining a first representation of the network based on the determined Thevenin equivalents, determining a modified representation of the network, wherein the modified representation is a representation of the network having at least one contingency......, wherein at least one Thevenin equivalent of at least one voltage controlled node is modified due to the at least one contingency, the modified network representation being determined on the basis of the modified Thevenin equivalents, calculating voltage angles of the modified Thevenin equivalents......, and evaluating the voltage angles to determine whether the network having at least one contingency admit a steady state. Also a method of providing information on a real time static security assessment of a power system is disclosed....

Biological Activities of Hominis Placenta Herbal Acupuncture prepared by Hydrochloric Acid Hydrolysis

Directory of Open Access Journals (Sweden)

Geun-young Seo

2010-06-01

Full Text Available Reactive Oxygen Species(ROS are continuously produced at a high rate as a by-product of aerobic metabolism. Since tissue damage by free radical increases with age, the reactive oxygen species(ROS such as hydrogen peroxide(H2O2, nitric oxide(NO. Several lines of evidence provided that ROS appears to cause to develop aging-related various diseases such as cancer, arthritis, cardiovascular disease. In this study, we have conducted to investigate the biological activities of Hominis Placenta Herbal Acupuncture by measuring total polyphenol content, DPPH radical scavenging, ABTS radical scavenging, Superoxide dismutase(SOD-like activity, Nitrite scavenging ability in vitro. The total polyphenol contents of Hominis Placenta Herbal Acupuncture was 24.6㎖/㎖. Elctron donation ability on DPPH was 49.4%. The 2,2'-azinobis-3-ehtlbezothiazoline-6-sulfonic acid radical decolorization (ABTS was 50.01%, similar to the DPPH free radical scavenging. The superoxide dismutase (SOD-like activities of hominis placenta herbal acupuncture was 50.876%. The nitrite scavenging abilities at pH 1.5, pH 3.0, pH 6.0 were 52.8%, 29.4%, 15.4%, respectively; these abilities decreased as pH increased. We conclude that Hominis Placenta Herbal Acupuncture may be useful as potential sources of antioxidant.

Rewiring protein synthesis: From natural to synthetic amino acids.

Science.gov (United States)

Fan, Yongqiang; Evans, Christopher R; Ling, Jiqiang

2017-11-01

The protein synthesis machinery uses 22 natural amino acids as building blocks that faithfully decode the genetic information. Such fidelity is controlled at multiple steps and can be compromised in nature and in the laboratory to rewire protein synthesis with natural and synthetic amino acids. This review summarizes the major quality control mechanisms during protein synthesis, including aminoacyl-tRNA synthetases, elongation factors, and the ribosome. We will discuss evolution and engineering of such components that allow incorporation of natural and synthetic amino acids at positions that deviate from the standard genetic code. The protein synthesis machinery is highly selective, yet not fixed, for the correct amino acids that match the mRNA codons. Ambiguous translation of a codon with multiple amino acids or complete reassignment of a codon with a synthetic amino acid diversifies the proteome. Expanding the genetic code with synthetic amino acids through rewiring protein synthesis has broad applications in synthetic biology and chemical biology. Biochemical, structural, and genetic studies of the translational quality control mechanisms are not only crucial to understand the physiological role of translational fidelity and evolution of the genetic code, but also enable us to better design biological parts to expand the proteomes of synthetic organisms. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

Teleparallel equivalent of Lovelock gravity

Science.gov (United States)

González, P. A.; Vásquez, Yerko

2015-12-01

There is a growing interest in modified gravity theories based on torsion, as these theories exhibit interesting cosmological implications. In this work inspired by the teleparallel formulation of general relativity, we present its extension to Lovelock gravity known as the most natural extension of general relativity in higher-dimensional space-times. First, we review the teleparallel equivalent of general relativity and Gauss-Bonnet gravity, and then we construct the teleparallel equivalent of Lovelock gravity. In order to achieve this goal, we use the vielbein and the connection without imposing the Weitzenböck connection. Then, we extract the teleparallel formulation of the theory by setting the curvature to null.

Biomagnification of bioassay derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents

Science.gov (United States)

Jones, P.D.; Ankley, G.T.; Best, D. A.; Crawford, R.; DeGalan, N.; Giesy, J.P.; Kubiak, T.J.; Ludwig, J. P.; Newsted, J.L.; Tillitt, D. E.; Verbrugge, D.A.

1993-01-01

In recent years contamination of the Great Lakes ecosystem with planar chlorinated hydrocarbons (PCHs) has attracted considerable concern due to their known reproductive and teratogenic effects. The H4IIE bioassay has been standardized as a means of measuring the biological potency of a PCH mixture as 2,3,7,8-tetrachloro-p-dibenzodioxin equivalents (TCDD-EQ). Using this bioassay we have investigated the biomagnification of TCDD-EQ in a semi-closed ecosystem. The biomagnification of TCDD-EQ is demonstrated and results indicate that the food chain is the major pathway for TCDD-EQ through this ecosystem. The H4IIE assay system is demonstrated to be a viable integrative measure of the total concentration of TCDD-EQ in different trophic levels.

Dark matter and the equivalence principle

Science.gov (United States)

Frieman, Joshua A.; Gradwohl, Ben-Ami

1993-01-01

A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

Equivalence of several Chern-Simons matter models

International Nuclear Information System (INIS)

Chen, W.; Itoi, C.

1994-01-01

Chern-Simons (CS) coupling characterizes not only statistics, but also spin and scaling dimension of matter fields. We demonstrate spin transmutation in relativistic CS matter theory, and moreover show equivalence of several models. We study the CS vector model in some detail, which provides a consistent check to the assertion of the equivalence

Finding small equivalent decision trees is hard

NARCIS (Netherlands)

Zantema, H.; Bodlaender, H.L.

2000-01-01

Two decision trees are called decision equivalent if they represent the same function, i.e., they yield the same result for every possible input. We prove that given a decision tree and a number, to decide if there is a decision equivalent decision tree of size at most that number is NPcomplete. As

Higher-order gravity and the classical equivalence principle

Science.gov (United States)

Accioly, Antonio; Herdy, Wallace

2017-11-01

As is well known, the deflection of any particle by a gravitational field within the context of Einstein’s general relativity — which is a geometrical theory — is, of course, nondispersive. Nevertheless, as we shall show in this paper, the mentioned result will change totally if the bending is analyzed — at the tree level — in the framework of higher-order gravity. Indeed, to first order, the deflection angle corresponding to the scattering of different quantum particles by the gravitational field mentioned above is not only spin dependent, it is also dispersive (energy-dependent). Consequently, it violates the classical equivalence principle (universality of free fall, or equality of inertial and gravitational masses) which is a nonlocal principle. However, contrary to popular belief, it is in agreement with the weak equivalence principle which is nothing but a statement about purely local effects. It is worthy of note that the weak equivalence principle encompasses the classical equivalence principle locally. We also show that the claim that there exists an incompatibility between quantum mechanics and the weak equivalence principle, is incorrect.

Gamma-hydroxybutyric acid endogenous production and post-mortem behaviour - the importance of different biological matrices, cut-off reference values, sample collection and storage conditions.

Science.gov (United States)

Castro, André L; Dias, Mário; Reis, Flávio; Teixeira, Helena M

2014-10-01

Gamma-Hydroxybutyric Acid (GHB) is an endogenous compound with a story of clinical use, since the 1960's. However, due to its secondary effects, it has become a controlled substance, entering the illicit market for recreational and "dance club scene" use, muscle enhancement purposes and drug-facilitated sexual assaults. Its endogenous context can bring some difficulties when interpreting, in a forensic context, the analytical values achieved in biological samples. This manuscript reviewed several crucial aspects related to GHB forensic toxicology evaluation, such as its post-mortem behaviour in biological samples; endogenous production values, whether in in vivo and in post-mortem samples; sampling and storage conditions (including stability tests); and cut-off reference values evaluation for different biological samples, such as whole blood, plasma, serum, urine, saliva, bile, vitreous humour and hair. This revision highlights the need of specific sampling care, storage conditions, and cut-off reference values interpretation in different biological samples, essential for proper practical application in forensic toxicology. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Structural transformations on N-acetylneuraminic acid

International Nuclear Information System (INIS)

Schmid, W.

1986-01-01

Structural transformations on N-Acetylneuraminic acid are of special interest because of the biological importance of this compound. Although many stereo- and regioselective variations (especially for pyranoid derivatives) have been reported, no detailed studies of the furanoid derivatives from N-Acetylneuramino-1, 4-lactone diethyl dithioacetal have been described hitherto. Therefore a series of derivatives of the Neu5Ac-lactone diethyl dithioacetal has been investigated by n.m.r. spectroscopic techniques. The complete assignment of the 1 H and 13 C resonances was achieved by relaxation time measurements, decoupling experiments and 2-D - shiftcorrelation spectroscopy. The influence of different substituents on the conformational behavior is also discussed. For the Tetra-O-Acetyl-N-acetylneuraminic acid-γ-lactone diethyl dithioacetal the conformation in solution could be determined. The observed data were explained by a zigzag conformation of the backbone as described for the acetylated mannose diethyl dithioacetal. The synthesis of the tetrazole-analogue of N-Acetylneuraminic acid is also described. This compound is of special biological interest because there is a similarity in acidity between the carboxyl-group and the tetrazole-function and the metabolic stability of the tetrazole function is enhanced in comparison with the carboxyl-group. Many of the biological functions of N-Acetylneuraminic acid are connected with the presence of the carboxyl-group. It was therefore interesting to transform this group to the bioisostere tetrazole-function to investigate the influence of the tetrazole-group of this compound on biological activity in the future. During the application of protective groups in the field of Neuraminic acid chemistry a new compound, an ortholactone-derivative of Neu5Ac, was discovered. It's structure is similar to an adamantanecage and the chemistry of such an orthoester function opens new possibilities for structural transformations on N

Mercury analysis of acid- and alkaline-reduced biological samples: identification of meta-cinnabar as the major biotransformed compound in algae.

Science.gov (United States)

Kelly, David; Budd, Kenneth; Lefebvre, Daniel D

2006-01-01

The biotransformation of Hg(II) in pH-controlled and aerated algal cultures was investigated. Previous researchers have observed losses in Hg detection in vitro with the addition of cysteine under acid reduction conditions in the presence of SnCl2. They proposed that this was the effect of Hg-thiol complexing. The present study found that cysteine-Hg, protein and nonprotein thiol chelates, and nucleoside chelates of Hg were all fully detectable under acid reduction conditions without previous digestion. Furthermore, organic (R-Hg) mercury compounds could not be detected under either the acid or alkaline reduction conditions, and only beta-HgS was detected under alkaline and not under acid SnCl2 reduction conditions. The blue-green alga Limnothrix planctonica biotransformed the bulk of Hg(II) applied as HgCl2 into a form with the analytical properties of beta-HgS. Similar results were obtained for the eukaryotic alga Selenastrum minutum. No evidence for the synthesis of organomercurials such as CH3Hg+ was obtained from analysis of either airstream or biomass samples under the aerobic conditions of the study. An analytical procedure that involved both acid and alkaline reduction was developed. It provides the first selective method for the determination of beta-HgS in biological samples. Under aerobic conditions, Hg(II) is biotransformed mainly into beta-HgS (meta-cinnabar), and this occurs in both prokaryotic and eukaryotic algae. This has important implications with respect to identification of mercury species and cycling in aquatic habitats.

Mercury Analysis of Acid- and Alkaline-Reduced Biological Samples: Identification of meta-Cinnabar as the Major Biotransformed Compound in Algae†

Science.gov (United States)

Kelly, David; Budd, Kenneth; Lefebvre, Daniel D.

2006-01-01

The biotransformation of HgII in pH-controlled and aerated algal cultures was investigated. Previous researchers have observed losses in Hg detection in vitro with the addition of cysteine under acid reduction conditions in the presence of SnCl2. They proposed that this was the effect of Hg-thiol complexing. The present study found that cysteine-Hg, protein and nonprotein thiol chelates, and nucleoside chelates of Hg were all fully detectable under acid reduction conditions without previous digestion. Furthermore, organic (R-Hg) mercury compounds could not be detected under either the acid or alkaline reduction conditions, and only β-HgS was detected under alkaline and not under acid SnCl2 reduction conditions. The blue-green alga Limnothrix planctonica biotransformed the bulk of HgII applied as HgCl2 into a form with the analytical properties of β-HgS. Similar results were obtained for the eukaryotic alga Selenastrum minutum. No evidence for the synthesis of organomercurials such as CH3Hg+ was obtained from analysis of either airstream or biomass samples under the aerobic conditions of the study. An analytical procedure that involved both acid and alkaline reduction was developed. It provides the first selective method for the determination of β-HgS in biological samples. Under aerobic conditions, HgII is biotransformed mainly into β-HgS (meta-cinnabar), and this occurs in both prokaryotic and eukaryotic algae. This has important implications with respect to identification of mercury species and cycling in aquatic habitats. PMID:16391065

BH3105 type neutron dose equivalent meter of high sensitivity

International Nuclear Information System (INIS)

Ji Changsong; Zhang Enshan; Yang Jianfeng; Zhang Hong; Huang Jiling

1995-10-01

It is noted that to design a neutron dose meter of high sensitivity is almost impossible in the frame of traditional designing principle--'absorption net principle'. Based on a newly proposed principle of obtaining neutron dose equi-biological effect adjustment--' absorption stick principle', a brand-new neutron dose-equivalent meter with high neutron sensitivity BH3105 has been developed. Its sensitivity reaches 10 cps/(μSv·h -1 ), which is 18∼40 times higher than one of foreign products of the same kind and is 10 4 times higher than that of domestic FJ342 neutron rem-meter. BH3105 has a measurement range from 0.1μSv/h to 1 Sv/h which is 1 or 2 orders wider than that of the other's. It has the advanced properties of gamma-resistance, energy response, orientation, etc. (6 tabs., 5 figs.)

Industrial systems biology of Saccharomyces cerevisiae enables novel succinic acid cell factory.

Directory of Open Access Journals (Sweden)

José Manuel Otero

Full Text Available Saccharomyces cerevisiae is the most well characterized eukaryote, the preferred microbial cell factory for the largest industrial biotechnology product (bioethanol, and a robust commerically compatible scaffold to be exploitted for diverse chemical production. Succinic acid is a highly sought after added-value chemical for which there is no native pre-disposition for production and accmulation in S. cerevisiae. The genome-scale metabolic network reconstruction of S. cerevisiae enabled in silico gene deletion predictions using an evolutionary programming method to couple biomass and succinate production. Glycine and serine, both essential amino acids required for biomass formation, are formed from both glycolytic and TCA cycle intermediates. Succinate formation results from the isocitrate lyase catalyzed conversion of isocitrate, and from the α-keto-glutarate dehydrogenase catalyzed conversion of α-keto-glutarate. Succinate is subsequently depleted by the succinate dehydrogenase complex. The metabolic engineering strategy identified included deletion of the primary succinate consuming reaction, Sdh3p, and interruption of glycolysis derived serine by deletion of 3-phosphoglycerate dehydrogenase, Ser3p/Ser33p. Pursuing these targets, a multi-gene deletion strain was constructed, and directed evolution with selection used to identify a succinate producing mutant. Physiological characterization coupled with integrated data analysis of transcriptome data in the metabolically engineered strain were used to identify 2(nd-round metabolic engineering targets. The resulting strain represents a 30-fold improvement in succinate titer, and a 43-fold improvement in succinate yield on biomass, with only a 2.8-fold decrease in the specific growth rate compared to the reference strain. Intuitive genetic targets for either over-expression or interruption of succinate producing or consuming pathways, respectively, do not lead to increased succinate. Rather, we

Preparation of data relevant to ''Equivalent Uniform Burnup'' and Equivalent Initial Enrichment'' for burnup credit evaluation

Energy Technology Data Exchange (ETDEWEB)

Nomura, Yasushi; Okuno, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Murazaki, Minoru [Tokyo Nuclear Service Inc., Tokyo (Japan)

2001-11-01

Based on the PWR spent fuel composition data measured at JAERI, two kinds of simplified methods such as ''Equivalent Uniform Burnup'' and ''Equivalent Initial Enrichment'' have been introduced. And relevant evaluation curves have been prepared for criticality safety evaluation of spent fuel storage pool and transport casks, taking burnup of spent fuel into consideration. These simplified methods can be used to obtain an effective neutron multiplication factor for a spent fuel storage/transportation system by using the ORIGEN2.1 burnup code and the KENO-Va criticality code without considering axial burnup profile in spent fuel and other various factors introducing calculated errors. ''Equivalent Uniform Burnup'' is set up for its criticality analysis to be reactivity equivalent with the detailed analysis, in which the experimentally obtained isotopic composition together with a typical axial burnup profile and various factors such as irradiation history are considered on the conservative side. On the other hand, Equivalent Initial Enrichment'' is set up for its criticality analysis to be reactivity equivalent with the detailed analysis such as above when it is used in the so called fresh fuel assumption. (author)

DFT calculations, spectroscopic, thermal analysis and biological activity of Sm(III) and Tb(III) complexes with 2-aminobenzoic and 2-amino-5-chloro-benzoic acids

Science.gov (United States)

Essawy, Amr A.; Afifi, Manal A.; Moustafa, H.; El-Medani, S. M.

2014-10-01

The complexes of Sm(III) and Tb(III) with 2-aminobenzoic acid (anthranilic acid, AA) and 2-amino-5-chlorobenzoic acid (5-chloroanthranilic acid, AACl) were synthesized and characterized based on elemental analysis, IR and mass spectroscopy. The data are in accordance with 1:3 [Metal]:[Ligand] ratio. On the basis of the IR analysis, it was found that the metals were coordinated to bidentate anthranilic acid via the ionised oxygen of the carboxylate group and to the nitrogen of amino group. While in 5-chloroanthranilic acid, the metals were coordinated oxidatively to the bidentate carboxylate group without bonding to amino group; accordingly, a chlorine-affected coordination and reactivity-diversity was emphasized. Thermal analyses (TGA) and biological activity of the complexes were also investigated. Density Functional Theory (DFT) calculations at the B3LYP/6-311++G (d,p)_ level of theory have been carried out to investigate the equilibrium geometry of the ligand. The optimized geometry parameters of the complexes were evaluated using SDDALL basis set. Moreover, total energy, energy of HOMO and LUMO and Mullikan atomic charges were calculated. In addition, dipole moment and orientation have been performed and discussed.

Biologically-equivalent dose and long-term survival time in radiation treatments

International Nuclear Information System (INIS)

Zaider, Marco; Hanin, Leonid

2007-01-01

Within the linear-quadratic model the biologically-effective dose (BED)-taken to represent treatments with an equal tumor control probability (TCP)-is commonly (and plausibly) calculated according to BED(D) = -log[S(D)]/α. We ask whether in the presence of cellular proliferation this claim is justified and examine, as a related question, the extent to which BED approximates an isoeffective dose (IED) defined, more sensibly, in terms of an equal long-term survival probability, rather than TCP. We derive, under the assumption that cellular birth and death rates are time homogeneous, exact equations for the isoeffective dose, IED. As well, we give a rigorous definition of effective long-term survival time, T eff . By using several sets of radiobiological parameters, we illustrate potential differences between BED and IED on the one hand and, on the other, between T eff calculated as suggested here or by an earlier recipe. In summary: (a) the equations currently in use for calculating the effective treatment time may underestimate the isoeffective dose and should be avoided. The same is the case for the tumor control probability (TCP), only more so; (b) for permanent implants BED may be a poor substitute for IED; (c) for a fractionated treatment schedule, interpreting the observed probability of cure in terms of a TCP formalism that refers to the end of the treatment (rather than T eff ) may result in a miscalculation (underestimation) of the initial number of clonogens

Part II: Biomechanical assessment for a footprint-restoring transosseous-equivalent rotator cuff repair technique compared with a double-row repair technique.

Science.gov (United States)

Park, Maxwell C; Tibone, James E; ElAttrache, Neal S; Ahmad, Christopher S; Jun, Bong-Jae; Lee, Thay Q

2007-01-01

We hypothesized that a transosseous-equivalent repair would demonstrate improved tensile strength and gap formation between the tendon and tuberosity when compared with a double-row technique. In 6 fresh-frozen human shoulders, a transosseous-equivalent rotator cuff repair was performed: a suture limb from each of two medial anchors was bridged over the tendon and fixed laterally with an interference screw. In 6 contralateral matched-pair specimens, a double-row repair was performed. For all repairs, a materials testing machine was used to load each repair cyclically from 10 N to 180 N for 30 cycles; each repair underwent tensile testing to measure failure loads at a deformation rate of 1 mm/sec. Gap formation between the tendon edge and insertion was measured with a video digitizing system. The mean ultimate load to failure was significantly greater for the transosseous-equivalent technique (443.0 +/- 87.8 N) compared with the double-row technique (299.2 +/- 52.5 N) (P = .043). Gap formation during cyclic loading was not significantly different between the transosseous-equivalent and double-row techniques, with mean values of 3.74 +/- 1.51 mm and 3.79 +/- 0.68 mm, respectively (P = .95). Stiffness for all cycles was not statistically different between the two constructs (P > .40). The transosseous-equivalent rotator cuff repair technique improves ultimate failure loads when compared with a double-row technique. Gap formation is similar for both techniques. A transosseous-equivalent repair helps restore footprint dimensions and provides a stronger repair than the double-row technique, which may help optimize healing biology.

Synthetic biology: engineering molecular computers

CERN Multimedia

CERN. Geneva

2018-01-01

Complicated systems cannot survive the rigors of a chaotic environment, without balancing mechanisms that sense, decide upon and counteract the exerted disturbances. Especially so with living organisms, forced by competition to incredible complexities, escalating also their self-controlling plight. Therefore, they compute. Can we harness biological mechanisms to create artificial computing systems? Biology offers several levels of design abstraction: molecular machines, cells, organisms... ranging from the more easily-defined to the more inherently complex. At the bottom of this stack we find the nucleic acids, RNA and DNA, with their digital structure and relatively precise interactions. They are central enablers of designing artificial biological systems, in the confluence of engineering and biology, that we call Synthetic biology. In the first part, let us follow their trail towards an overview of building computing machines with molecules -- and in the second part, take the case study of iGEM Greece 201...

Effect of Hyaluronic Acid Incorporation Method on the Stability and Biological Properties of Polyurethane-Hyaluronic Acid Biomaterials

Science.gov (United States)

Ruiz, Amaliris; Rathnam, Kashmila R.; Masters, Kristyn S.

2014-01-01

The high failure rate of small diameter vascular grafts continues to drive the development of new materials and modification strategies that address this clinical problem, with biomolecule incorporation typically achieved via surface-based modification of various biomaterials. In this work, we examined whether the method of biomolecule incorporation (i.e., bulk vs. surface modification) into a polyurethane (PU) polymer impacted biomaterial performance in the context of vascular applications. Specifically, hyaluronic acid (HA) was incorporated into a poly(ether urethane) via bulk copolymerization or covalent surface tethering, and the resulting PU-HA materials characterized with respect to both physical and biological properties. Modification of PU with HA by either surface or bulk methods yielded materials that, when tested under static conditions, possessed no significant differences in their ability to resist protein adsorption, platelet adhesion, and bacterial adhesion, while supporting endothelial cell culture. However, only bulk-modified PU-HA materials were able to fully retain these characteristics following material exposure to flow, demonstrating a superior ability to retain the incorporated HA and minimize enzymatic degradation, protein adsorption, platelet adhesion, and bacterial adhesion. Thus, despite bulk methods rarely being implemented in the context of biomolecule attachment, these results demonstrate improved performance of PU-HA upon bulk, rather than surface, incorporation of HA. Although explored only in the context of PU-HA, the findings revealed by these experiments have broader implications for the design and evaluation of vascular graft modification strategies. PMID:24276670

Analysis of equivalent antenna based on FDTD method

Directory of Open Access Journals (Sweden)

Yun-xing Yang

2014-09-01

Full Text Available An equivalent microstrip antenna used in radio proximity fuse is presented. The design of this antenna is based on multilayer multi-permittivity dielectric substrate which is analyzed by finite difference time domain (FDTD method. Equivalent iterative formula is modified in the condition of cylindrical coordinate system. The mixed substrate which contains two kinds of media (one of them is airtakes the place of original single substrate. The results of equivalent antenna simulation show that the resonant frequency of equivalent antenna is similar to that of the original antenna. The validity of analysis can be validated by means of antenna resonant frequency formula. Two antennas have same radiation pattern and similar gain. This method can be used to reduce the weight of antenna, which is significant to the design of missile-borne antenna.

Neutralization of acidic pit lakes with biological methods complement the flooding with neutral surface water: strategies and sustainability; Neutralisation saurer Tagebauseen durch biologische Methoden als Ergaenzung zur Fremdflutung: Strategien und Nachhaltigkeit

Energy Technology Data Exchange (ETDEWEB)

Nixdorf, B.; Deneke, R. [Brandenburgische Technische Universitaet Cottbus (Germany). Institut fuer Boden, Wasser, Luft; Buettcher, H.; Uhlmann, W. [Institut fuer Wasser und Boden Dr. Uhlmann, Dresden (Germany)

2004-07-01

The aim of this project is to investigate the mechanisms of biogenic alkalinity production in highly acidic surface waters in the post-mining landscape and to develop alternative or additional strategies to overcome acidity by the use of basic biological processes. Current approaches such as flooding with neutral surface water, extensive liming and technical treatments are not suitable for many lakes because of limited water supply and special water chemistry in mining lakes. Therefore, basic research is needed in order to develop ecotechnological measures for the multitude of small and medium sized highly acidic mining lakes. Future treatments are designed to combine water supply and biological measures with the management of water quality by use of in-lake microbial processes (bacteria, phytoplankton). Research focuses on alkalinity response of aquatic ecosystems on nutrient enrichment, their catchment areas and the use of 'Constructed Wetlands' and will be generalized by application of hydrogeochemical models for alkalinity production. (orig.)

Biological effects of transuranium elements in experimental animals

International Nuclear Information System (INIS)

Bair, W.J.

1975-01-01

Results are reported from life span studies of the biological effects of the transuranium elements ( 238 Pu, 239 Pu, 241 Am, and 242 Cm) on laboratory animals following inhalation, skin absorption, or injection in various chemical forms. The dose levels at which major biological effects have been observed in experimental animals are discussed relative to the maximum permissible lung burden of 0.016 μCi for occupational exposures. Lung cancer has been observed at dose levels equivalent to about 100 times the maximum permissible lung burden. Current experiments directed towards determining whether health effects will occur at lower levels and the mechanisms by which α emitters induce cancer are reviewed. (U.S.)

What is Metaphysical Equivalence? | Miller | Philosophical Papers

African Journals Online (AJOL)

Theories are metaphysically equivalent just if there is no fact of the matter that could render one theory true and the other false. In this paper I argue that if we are judiciously to resolve disputes about whether theories are equivalent or not, we need to develop testable criteria that will give us epistemic access to the obtaining ...

Modular Synthesis of Biologically Active Phosphatidic Acid Probes Using Click Chemistry

Science.gov (United States)

Smith, Matthew D.; Sudhahar, Christopher G.; Gong, Denghuang; Stahelin, Robert V.

2018-01-01

Phosphatidic acid (PA) is an important signaling lipid that plays roles in a range of biological processes including both physiological and pathophysiological events. PA is one of a number of signaling lipids that can act as site-specific ligands for protein receptors in binding events that enforce membrane-association and generally regulate both receptor function and subcellular localization. However, elucidation of the full scope of PA activities has proven problematic, primarily due to the lack of a consensus sequence among PA-binding receptors. Thus, experimental approaches, such as those employing lipid probes, are necessary for characterizing interactions at the molecular level. Herein, we describe an efficient modular approach to the synthesis of a range of PA probes that employs a late stage introduction of reporter groups. This strategy was exploited in the synthesis of PA probes bearing fluorescent and photoaffinity tags as well as a bifunctional probe containing both a photoaffinity moiety and an azide as a secondary handle for purification purposes. To discern the ability of these PA analogues to mimic the natural lipid in protein binding properties, each compound was incorporated into vesicles for binding studies using a known PA receptor, the C2 domain of PKCα. In these studies, each compound exhibited binding properties that were comparable to those of synthetic PA, indicating their viability as probes for effectively studying the activities of PA in cellular processes. PMID:19668861

The Source Equivalence Acceleration Method

International Nuclear Information System (INIS)

Everson, Matthew S.; Forget, Benoit

2015-01-01

Highlights: • We present a new acceleration method, the Source Equivalence Acceleration Method. • SEAM forms an equivalent coarse group problem for any spatial method. • Equivalence is also formed across different spatial methods and angular quadratures. • Testing is conducted using OpenMOC and performance is compared with CMFD. • Results show that SEAM is preferable for very expensive transport calculations. - Abstract: Fine-group whole-core reactor analysis remains one of the long sought goals of the reactor physics community. Such a detailed analysis is typically too computationally expensive to be realized on anything except the largest of supercomputers. Recondensation using the Discrete Generalized Multigroup (DGM) method, though, offers a relatively cheap alternative to solving the fine group transport problem. DGM, however, suffered from inconsistencies when applied to high-order spatial methods. While an exact spatial recondensation method was developed and provided full spatial consistency with the fine group problem, this approach substantially increased memory requirements for realistic problems. The method described in this paper, called the Source Equivalence Acceleration Method (SEAM), forms a coarse-group problem which preserves the fine-group problem even when using higher order spatial methods. SEAM allows recondensation to converge to the fine-group solution with minimal memory requirements and little additional overhead. This method also provides for consistency when using different spatial methods and angular quadratures between the coarse group and fine group problems. SEAM was implemented in OpenMOC, a 2D MOC code developed at MIT, and its performance tested against Coarse Mesh Finite Difference (CMFD) acceleration on the C5G7 benchmark problem and on a 361 group version of the problem. For extremely expensive transport calculations, SEAM was able to outperform CMFD, resulting in speed-ups of 20–45 relative to the normal power

Acid Rain Analysis by Standard Addition Titration.

Science.gov (United States)

Ophardt, Charles E.

1985-01-01

The standard addition titration is a precise and rapid method for the determination of the acidity in rain or snow samples. The method requires use of a standard buret, a pH meter, and Gran's plot to determine the equivalence point. Experimental procedures used and typical results obtained are presented. (JN)

Using frequency equivalency in stability calculations

Energy Technology Data Exchange (ETDEWEB)

Gruzdev, I.A.; Temirbulatov, R.A.; Tereshko, L.A.

1981-01-01

A methodology for calculating oscillatory instability that involves using frequency equivalency is employed in carrying out the following proceedures: dividing an electric power system into subgroups; determining the adjustments to the automatic excitation control in each subsystem; simplifying the mathematical definition of the separate subsystems by using frequency equivalency; gradually re-tuning the automatic excitation control in the separate subsystems to account for neighboring subsystems by using their equivalent frequency characteristics. The methodology is to be used with a computer program to determine the gain in the stabilization channels of the automatic excitation control unit in which static stability of the entire aggregate of normal and post-breakdown conditions acceptable damping of transient processes are provided. The possibility of reducing the equation series to apply to chosen regions of the existing range of frequencies is demonstrated. The use of the methodology is illustrated in a sample study on stability in a Siberian unified power system.

Water equivalence of polymer gel dosimeters

International Nuclear Information System (INIS)

Sellakumar, P.; James Jebaseelan Samuel, E.; Supe, Sanjay S.

2007-01-01

To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z eff ), electron density (ρ e ), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μ en /ρ) and total stopping power (S/ρ) tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close ( en /ρ for all polymer gels were in close agreement ( tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

Equivalence principle violations and couplings of a light dilaton

International Nuclear Information System (INIS)

Damour, Thibault; Donoghue, John F.

2010-01-01

We consider possible violations of the equivalence principle through the exchange of a light 'dilaton-like' scalar field. Using recent work on the quark-mass dependence of nuclear binding, we find that the dilaton-quark-mass coupling induces significant equivalence-principle-violating effects varying like the inverse cubic root of the atomic number - A -1/3 . We provide a general parametrization of the scalar couplings, but argue that two parameters are likely to dominate the equivalence-principle phenomenology. We indicate the implications of this framework for comparing the sensitivities of current and planned experimental tests of the equivalence principle.

Antioxidant capacity and fatty acid profile of Centaurea kotschyi (Boiss. and Heldr.) Hayek var. persica (Boiss.) Wagenitz from Turkey

Energy Technology Data Exchange (ETDEWEB)

Zengin, G.; Guler, G.O.; Cakmak, Y.S.; Aktumseka, A.

2011-07-01

The antioxidant capacity of the methanolic extract and the fatty acid composition of C. kotschyi var. persica were investigated. Six different chemical methods were used to determine the antioxidant capacity. The fatty acid composition was analyzed using gas chromatography. The IC50 value of the extract was determined as 37.09 ig/ml (in the DPPH assay). In the {beta}carotene/linoleic acid system, the extract exhibited 65.22% inhibition against linoleic acid oxidation. The amount of total phenolic content and total antioxidant capacity were detected as 36.52 mg gallic acid equivalent (GAE)/g and 74.93 mg ascorbic acid equivalent (AE)/g, respectively. The major fatty acid in the composition of C. kotschyi var. persica was found to be C 18:3 u3 ({beta}-linolenic acid) by GC analysis. The results presented here indicate that C. kotschyi var. persica possess strong antioxidant properties. Therefore, the species can be used as a natural additive in food, cosmetic and pharmaceutical industries. (Author).

A bicategorical approach to Morita equivalence for von Neumann algebras

International Nuclear Information System (INIS)

Brouwer, R. M.

2003-01-01

We relate Morita equivalence for von Neumann algebras to the ''Connes fusion'' tensor product between correspondences. In the purely algebraic setting, it is well known that rings are Morita equivalent if they are equivalent objects in a bicategory whose 1-cells are bimodules. We present a similar result for von Neumann algebras. We show that von Neumann algebras form a bicategory, having Connes's correspondences as 1-morphisms, and (bounded) intertwiners as 2-morphisms. Further, we prove that two von Neumann algebras are Morita equivalent iff they are equivalent objects in the bicategory. The proofs make extensive use of the Tomita-Takesaki modular theory

The use of electrothermal vaporizer coupled to the inductively coupled plasma mass spectrometry for the determination of arsenic, selenium and transition metals in biological samples treated with formic acid

Energy Technology Data Exchange (ETDEWEB)

Tormen, Luciano, E-mail: lucianotormen@hotmail.com [Departamento de Quimica, Universidade Federal de Santa Catarina, Depto. Quimica, Campus Trindade, 88040-900 Florianopolis, SC (Brazil); Universidade Federal da Fronteira Sul - UFFS, Campus Laranjeiras do Sul, 85303-775 Laranjeiras do Sul, PR (Brazil); Gil, Raul A. [Instituto de Quimica de San Luis (UNSL-CONICET), Chacabuco y Pedernera, D5700BWQ San Luis (Argentina); Frescura, Vera L.A. [Departamento de Quimica, Universidade Federal de Santa Catarina, Depto. Quimica, Campus Trindade, 88040-900 Florianopolis, SC (Brazil); Martinez, Luis Dante [Instituto de Quimica de San Luis (UNSL-CONICET), Chacabuco y Pedernera, D5700BWQ San Luis (Argentina); Curtius, Adilson J. [Departamento de Quimica, Universidade Federal de Santa Catarina, Depto. Quimica, Campus Trindade, 88040-900 Florianopolis, SC (Brazil)

2012-03-02

Highlights: Black-Right-Pointing-Pointer Simple sample treatment of biologic samples with formic acid is proposed. Black-Right-Pointing-Pointer The treatment with formic acid is easy, rapid, less expensive and environmental friendly allowing a high sample throughput. Black-Right-Pointing-Pointer External calibration with aqueous standard allows the simultaneous determination of As, Co, Cu, Fe, Mn, Ni, Se and V. Black-Right-Pointing-Pointer The use of ETV avoids plasma instability, carbon deposit on the cones and does not require sample digestion. - Abstract: A fast method for the determination of As, Co, Cu, Fe, Mn, Ni, Se and V in biological samples by ETV-ICP-MS, after a simple sample treatment with formic acid, is proposed. Approximately 75 mg of each sample is mixed with 5 mL of formic acid, kept at 90 Degree-Sign C for 1 h and then diluted with nitric acid aqueous solution to a 5% (v/v) formic acid and 1% (v/v) nitric acid final concentrations. A palladium solution was used as a chemical modifier. The instrumental conditions, such as carrier gas flow rate, RF power, pyrolysis and vaporization temperatures and argon internal flow rate during vaporization were optimized. The formic acid causes a slight decrease of the analytes signal intensities, but does not increase the signal of the mainly polyatomic ions ({sup 14}N{sup 35}Cl{sup +}, {sup 14}N{sup 12}C{sup +}, {sup 40}Ar{sup 12}C{sup +}, {sup 13}C{sup 37}Cl{sup +}, {sup 40}Ar{sup 36}Ar{sup +}, {sup 40}Ar{sup 35}Cl{sup +}, {sup 35}Cl{sup 16}O{sup +}, {sup 40}Ar{sup 18}O{sup +}) that affect the analytes signals. The effect of charge transfer reactions, that could increase the ionization efficiency of some elements with high ionization potentials was not observed due to the elimination of most of the organic compounds during the pyrolysis step. External calibration with aqueous standard solutions containing 5% (v/v) formic acid allows the simultaneous determination of all analytes with high accuracy. The

Extension of the tables of PDD, TMR and equivalent squares of the BJR 25

International Nuclear Information System (INIS)

Balmaceda, Daniel; Rojas, Jorge E.

2004-01-01

The cancer patients treatment times were revised manually in the Servicio de Radioterapia del Hospital Mexico. Those patients will be treated in the 2 units of Cobalt-60. Theraplan Plus (version 3.5) is the system to make dosimetries, after of its results, the medical physician or any of the dosimeters do the manual revision of the treatment times. In this manual revision are utilized the tables of PDD, TAR and equivalent squares of BJR Supplement 25 prepared by the British Institute of Radiology and the Institution of Physics and Engineering in Medicine and Biology. The table of PDD of BJR 25 (Cobalt-60, 80 cm. SSD) was enlarged in the year 2000 by mean of interpolation with polynomial of Lagrange by one author of this job, to use of the personnel of the Servicio de Radioterapia del Hospital Mexico. In this job it is applied other scheme of interpolation (Cubic Splines) for the table of PDD, the tables of TAR and the equivalent squares of rectangular fields of BJR 25. It is presented in this report the methodology followed as well as the final versions of the tables [es

On The Construction of Models for Electrical Conduction in Biological Tissues

International Nuclear Information System (INIS)

Gomez-Aguilar, F.; Bernal-Alvarado, J.; Cordova-Fraga, T.; Rosales-Garcia, J.; Guia-Calderon, M.

2010-01-01

Applying RC circuit theory, a theoretical representation for the electrical conduction in a biological multilayer system was developed. In particular an equivalent circuit for the epidermis, dermis and the subcutaneous tissue was constructed. This model includes an equivalent circuit, inside the dermis, in order to model a small formation like tumor. This work shows the feasibility to apply superficial electrodes to detect subcutaneous abnormalities. The behavior of the model is shown in the form of a frequency response chart. The Bode and Nyquist plots are also obtained. This theoretical frame is proposed to be a general treatment to describe the bioelectrical transport in a three layer bioelectrical system.

Caffeic acid derivative from Clinopodium umbrosum

Directory of Open Access Journals (Sweden)

M. Esfahanizadeh

2017-11-01

Full Text Available Background and objectives: Plants of genus Clinopodium have been used in different cultures as traditional medicines.Due to theimportance of medicinal properties of the genus Clinopodium, C. umbrosum was selected for phytochemical analysis along with evaluation of its antioxidant property. Methods: The aerial parts of C. umbrosum were extracted with petroleum ether, chloroform, and methanol. Later, the methanol extract was fractionated via solid phase extraction and reversed phase high performance liquid chromatography. Consequently, structure of the isolated compound was analyzed through spectral analysis of 1D and 2D NMR data. Besides, the essential oil of C. umbrosum achieved through hydrodistillation was analyzed via gas chromatography-mass spectrometry (GC-MS. Additionally, the antioxidant property of C. umbrosum methanol extracttogether with its phenolics and flavonoids content were assessed. Results: Structure elucidation of the purified compound revealed presence of a caffeic acid derivative in C. umbrosum methanol extract. GC-MS analysis of the essential oil showed limonene, acetophenone, palmitic acid and phytol as the most frequent components of the essential oil. Moreover, the RC50 value for free radical scavenging activity of  the methanol extract was determined as 38.52 µg/mL and values for the total phenolics and flavonoids contact were calculated as 5.14 g gallic acid equivalent and 4.25 g quercetin equivalent per 100 g of dried plant material, respectively.  Conclusion: Overall, the present study was the first report on the phytochemical analysis of C. umbrosum whichrevealed presence of rosmarinic acid as the main component of the methanol extract with prominent antioxidant activity.

Biochemical, biological and molecular characterization of an L-Amino acid oxidase (LAAO) purified from Bothrops pictus Peruvian snake venom.

Science.gov (United States)

Lazo, Fanny; Vivas-Ruiz, Dan E; Sandoval, Gustavo A; Rodríguez, Edith F; Kozlova, Edgar E G; Costal-Oliveira, F; Chávez-Olórtegui, Carlos; Severino, Ruperto; Yarlequé, Armando; Sanchez, Eladio F

2017-12-01

An L-amino acid oxidase from Peruvian Bothrops pictus (Bpic-LAAO) snake venom was purified using a combination of size-exclusion and ion-exchange chromatography. Bpic-LAAO is a homodimeric glycosylated flavoprotein with molecular mass of ∼65 kDa under reducing conditions and ∼132 kDa in its native form as analyzed by SDS-PAGE and gel filtration chromatography, respectively. N-terminal amino acid sequencing showed highly conserved residues in a glutamine-rich motif related to binding substrate. The enzyme exhibited optimal activity towards L-Leu at pH 8.5, and like other reported SV-LAAOs, it is stable until 55 °C. Kinetic studies showed that the cations Ca 2+ , Mg 2+ and Mn 2+ did not alter Bpic-LAAO activity; however, Zn 2+ is an inhibitor. Some reagents such as β-mercaptoethanol, glutathione and iodoacetate had inhibitory effect on Bpic-LAAO activity, but PMSF, EDTA and glutamic acid did not affect its activity. Regarding the biological activities of Bpic-LAAO, this enzyme induced edema in mice (MED = 7.8 μg), and inhibited human platelet aggregation induced by ADP in a dose-dependent manner and showed antibacterial activity on Gram (+) and Gram (-) bacteria. Bpic-LAAO cDNA of 1494 bp codified a mature protein with 487 amino acid residues comprising a signal peptide of 11 amino acids. Finally, the phylogenetic tree obtained with other sequences of LAAOs, evidenced its similarity to other homologous enzymes, showing two well-established monophyletic groups in Viperidae and Elapidae families. Bpic-LAAO is evolutively close related to LAAOs from B. jararacussu, B. moojeni and B. atrox, and together with the LAAO from B. pauloensis, form a well-defined cluster of the Bothrops genus. Copyright © 2017 Elsevier Ltd. All rights reserved.

An equivalent fluid/equivalent medium approach for the numerical simulation of coastal landslides propagation: theory and case studies

OpenAIRE

P. Mazzanti; F. Bozzano

2009-01-01

Coastal and subaqueous landslides can be very dangerous phenomena since they are characterised by the additional risk of induced tsunamis, unlike their completely-subaerial counterparts. Numerical modelling of landslides propagation is a key step in forecasting the consequences of landslides. In this paper, a novel approach named Equivalent Fluid/Equivalent Medium (EFEM) has been developed. It adapts common numerical models and software that were originally designed for subaerial landslides i...

The equivalence principle in classical mechanics and quantum mechanics

OpenAIRE

Mannheim, Philip D.

1998-01-01

We discuss our understanding of the equivalence principle in both classical mechanics and quantum mechanics. We show that not only does the equivalence principle hold for the trajectories of quantum particles in a background gravitational field, but also that it is only because of this that the equivalence principle is even to be expected to hold for classical particles at all.

Unified data model for biological data

International Nuclear Information System (INIS)

Idrees, M.

2014-01-01

A data model empowers us to store, retrieve and manipulate data in a unified way. We consider the biological data consists of DNA (De-Oxyribonucleic Acid), RNA (Ribonucleic Acid) and protein structures. In our Bioinformatics Lab (Bioinformatics Lab, Alkhawarizmi Institute of Computer Science, University of Engineering and Technology, Lahore, Pakistan), we have already proposed two data models for DNA and protein structures individually. In this paper, we propose a unified data model by using the data models of TOS (Temporal Object Oriented System) after making some necessary modifications to this data model and our already proposed the two data models. This proposed unified data model can be used for the modeling and maintaining the biological data (i.e. DNA, RNA and protein structures), in a single unified way. (author)

Understanding S-Shaped Current-Voltage Characteristics in Organic Solar Cells Containing a TiOx Inter layer with Impedance Spectroscopy and Equivalent Circuit Analysis

NARCIS (Netherlands)

Ecker, Bernhard; Egelhaaf, Hans-Joachim; Steim, Roland; Parisi, Juergen; von Hauff', Elizabeth

2012-01-01

In this study we propose an equivalent circuit model to describe S-shaped current–voltage (I–V) characteristics in inverted solar cells with a TiOx interlayer between the cathode and the poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester active layer. Initially the solar cells

Ionic liquid and solid HF equivalent amine-poly(hydrogen fluoride) complexes effecting efficient environmentally friendly isobutane-isobutylene alkylation.

Science.gov (United States)

Olah, George A; Mathew, Thomas; Goeppert, Alain; Török, Béla; Bucsi, Imre; Li, Xing-Ya; Wang, Qi; Marinez, Eric R; Batamack, Patrice; Aniszfeld, Robert; Prakash, G K Surya

2005-04-27

Isoparaffin-olefin alkylation was investigated using liquid as well as solid onium poly(hydrogen fluoride) catalysts. These new immobilized anhydrous HF catalysts contain varied amines and nitrogen-containing polymers as complexing agents. The liquid poly(hydrogen fluoride) complexes of amines are typical ionic liquids, which are convenient media and serve as HF equivalent catalysts with decreased volatility for isoparaffin-olefin alkylation. Polymeric solid amine:poly(hydrogen fluoride) complexes are excellent solid HF equivalents for similar alkylation acid catalysis. Isobutane-isobutylene or 2-butene alkylation gave excellent yields of high octane alkylates (up to RON = 94). Apart from their excellent catalytic performance, the new catalyst systems significantly reduce environmental hazards due to the low volatility of complexed HF. They represent a new, "green" class of catalyst systems for alkylation reactions, maintaining activity of HF while minimizing its environmental hazards.

Mathematical modeling of the lithium, thionyl chloride static cell: acid electrolyte

Energy Technology Data Exchange (ETDEWEB)

Tsaur, K.-C.; Pollard, R.

1984-05-01

A mathematical model for a complete Li/SOCl/sub 2/ static cell with acid electrolyte is presented. Concentrated solution theory is extended to account for the presence of two neutral species in the electrolyte. The effects of initial acid concentration, positive electrode thickness, and galvanostatic discharge rate on cell performance are elucidated. Results are compared with equivalent cells that use a neutral electrolyte.

A Neurocomputational Approach to Trained and Transitive Relations in Equivalence Classes

Directory of Open Access Journals (Sweden)

Ángel E. Tovar

2017-10-01

Full Text Available A stimulus class can be composed of perceptually different but functionally equivalent stimuli. The relations between the stimuli that are grouped in a class can be learned or derived from other stimulus relations. If stimulus A is equivalent to B, and B is equivalent to C, then the equivalence between A and C can be derived without explicit training. In this work we propose, with a neurocomputational model, a basic learning mechanism for the formation of equivalence. We also describe how the relatedness between the members of an equivalence class is developed for both trained and derived stimulus relations. Three classic studies on stimulus equivalence are simulated covering typical and atypical populations as well as nodal distance effects. This model shows a mechanism by which certain stimulus associations are selectively strengthened even when they are not co-presented in the environment. This model links the field of equivalence classes to accounts of Hebbian learning and categorization, and points to the pertinence of modeling stimulus equivalence to explore the effect of variations in training protocols.

[Synthesis and degradation of hyaluronic acid by bacteria of Streptococcus genus].

Science.gov (United States)

Beloded, A V; Samoĭlenko, I I; Tsepilov, R N

2010-01-01

Modern data on metabolism of hyaluronic acid by bacteria from Streptococcus genus are presented. Several species of bacteria forming capsule from hyaluronic acid, which is analogous to glycosaminoglycan of vertebrates, are considered. Different aspects of hyaluronic acid synthesis are described: biochemical synthesis pathway, genetic basis, regulation of expression of genes belonging to hyaluronic acid synthesis operon. Biological role and physiologic importance of hyaluronic acid for bacteria, including its role in overcoming immune barrier by pathogenic species, are discussed. Process of depolymerization of hyaluronic acid in presence of hyaluronatlyases secreted by certain streptococci is considered. Characteristic of streptococcal enzyme hyaluronatlyase, its mechanism of catalytic effect, and biological function are presented.

Modular microfluidic system for biological sample preparation

Science.gov (United States)

Rose, Klint A.; Mariella, Jr., Raymond P.; Bailey, Christopher G.; Ness, Kevin Dean

2015-09-29

A reconfigurable modular microfluidic system for preparation of a biological sample including a series of reconfigurable modules for automated sample preparation adapted to selectively include a) a microfluidic acoustic focusing filter module, b) a dielectrophoresis bacteria filter module, c) a dielectrophoresis virus filter module, d) an isotachophoresis nucleic acid filter module, e) a lyses module, and f) an isotachophoresis-based nucleic acid filter.

On the calibration of photon dosemeters in the equivalent dose units

International Nuclear Information System (INIS)

Bregadze, Yu.I.; Isaev, B.M.; Maslyaev, P.F.

1980-01-01

General aspects of transition from exposure dose of photo radiation to equivalent one are considered. By determination the equivalent dose is a function of point location in an irradiated object, that is why it is necessary to know equivalent dose distribution in the human body for uniform description of the risk degree. The international electrotechnical comission recommends to measure equivalent doses at 7 and 800 mg/cm 2 depths in a tissue-equivalent ball with 30 cm diameter, calling them skin equivalent dose and depth equivalent dose, respectively, and to compare them with the permissible 500 mZ and 50 mZ a year, respectively. Practical transition to using equivalent dose for evaluation of radiation danger of being in photon radiation field of low energy should include measures on regraduating already produced dose meters, graduating the dose meters under production and developing the system of their metrologic supply [ru

Application of neutrons in biology

International Nuclear Information System (INIS)

Cser, L.

1982-01-01

Applications of neutron scattering to determine the structure of biological macromolecules are reviewed. A theoretical and experimental introduction to neutron scattering and its mathematical description is given. The analysis of crystal structure using neutron scattering and the problem of Fourier reconstruction of structure are discussed. Some special problems concerning biological materials are described. The isotope effect of neutron scattering is applied to determine and identify the hydrogen atoms in biological macromolecules. Some examples illustrating the structure determination of amino acids and proteins are given. Mathematical methods of evaluation of small angle neutron scattering experiments and applications to investigate E. coli ribosome are described. New developments and new research trends are also reviewed. (D.Gy.)

Functional biology of sympatric krill species

DEFF Research Database (Denmark)

Agersted, Mette Dalgaard; Nielsen, Torkel Gissel

2016-01-01

Here we compare the functional biology of the sympatric krill species, Meganyctiphanes norvegica and Thysanoessa inermis. For M. norvegica, we investigated functional responses on diatoms and copepods, together with prey size spectra on plankton ,400 mm and copepods in the size range 500–3220 mm....... For T. inermis, only prey size spectrum on plankton ,400 mm were investigated. The prey size ranges of both species include organisms ,400 mm, and they consequently graze on several trophic levels. However, T. inermis feed on cells ,10 mm equivalent spherical diameter (ESD), whereas M. norvegica only...

Universal nucleic acids sample preparation method for cells, spores and their mixture

Science.gov (United States)

Bavykin, Sergei [Darien, IL

2011-01-18

The present invention relates to a method for extracting nucleic acids from biological samples. More specifically the invention relates to a universal method for extracting nucleic acids from unidentified biological samples. An advantage of the presently invented method is its ability to effectively and efficiently extract nucleic acids from a variety of different cell types including but not limited to prokaryotic or eukaryotic cells and/or recalcitrant organisms (i.e. spores). Unlike prior art methods which are focused on extracting nucleic acids from vegetative cell or spores, the present invention effectively extracts nucleic acids from spores, multiple cell types or mixtures thereof using a single method. Important that the invented method has demonstrated an ability to extract nucleic acids from spores and vegetative bacterial cells with similar levels effectiveness. The invented method employs a multi-step protocol which erodes the cell structure of the biological sample, isolates, labels, fragments nucleic acids and purifies labeled samples from the excess of dye.

The lexicographical handling of grammatical equivalence: the case ...

African Journals Online (AJOL)

Lexicographers compiling translating dictionaries are not exclusively concerned with semantic equivalence when selecting translating equivalents for lemmata, but often include also grammatical information in illustrative examples when the lexical item to be translated does not have an exact grammatical counterpart in the ...

The cross-cultural equivalence of participation instruments: a systematic review.

Science.gov (United States)

Stevelink, S A M; van Brakel, W H

2013-07-01

Concepts such as health-related quality of life, disability and participation may differ across cultures. Consequently, when assessing such a concept using a measure developed elsewhere, it is important to test its cultural equivalence. Previous research suggested a lack of cultural equivalence testing in several areas of measurement. This paper reviews the process of cross-cultural equivalence testing of instruments to measure participation in society. An existing cultural equivalence framework was adapted and used to assess participation instruments on five categories of equivalence: conceptual, item, semantic, measurement and operational equivalence. For each category, several aspects were rated, resulting in an overall category rating of 'minimal/none', 'partial' or 'extensive'. The best possible overall study rating was five 'extensive' ratings. Articles were included if the instruments focussed explicitly on measuring 'participation' and were theoretically grounded in the ICIDH(-2) or ICF. Cross-validation articles were only included if it concerned an adaptation of an instrument developed in a high or middle-income country to a low-income country or vice versa. Eight cross-cultural validation studies were included in which five participation instruments were tested (Impact on Participation and Autonomy, London Handicap Scale, Perceived Impact and Problem Profile, Craig Handicap Assessment Reporting Technique, Participation Scale). Of these eight studies, only three received at least two 'extensive' ratings for the different categories of equivalence. The majority of the cultural equivalence ratings given were 'partial' and 'minimal/none'. The majority of the 'none/minimal' ratings were given for item and measurement equivalence. The cross-cultural equivalence testing of the participation instruments included leaves much to be desired. A detailed checklist is proposed for designing a cross-validation study. Once a study has been conducted, the checklist can

Amino Acid Patterns around Disulfide Bonds

Directory of Open Access Journals (Sweden)

Brett Drury

2010-11-01

Full Text Available Disulfide bonds provide an inexhaustible source of information on molecular evolution and biological specificity. In this work, we described the amino acid composition around disulfide bonds in a set of disulfide-rich proteins using appropriate descriptors, based on ANOVA (for all twenty natural amino acids or classes of amino acids clustered according to their chemical similarities and Scheffé (for the disulfide-rich proteins superfamilies statistics. We found that weakly hydrophilic and aromatic amino acids are quite abundant in the regions around disulfide bonds, contrary to aliphatic and hydrophobic amino acids. The density distributions (as a function of the distance to the center of the disulfide bonds for all defined entities presented an overall unimodal behavior: the densities are null at short distances, have maxima at intermediate distances and decrease for long distances. In the end, the amino acid environment around the disulfide bonds was found to be different for different superfamilies, allowing the clustering of proteins in a biologically relevant way, suggesting that this type of chemical information might be used as a tool to assess the relationship between very divergent sets of disulfide-rich proteins.

Detection of biologically active isomers of conjugated linoleic acid in kaymak

Directory of Open Access Journals (Sweden)

Ökten, Sevtap

2005-12-01

Full Text Available Numerous physiological effects are attributed to conjugated linoleic acids (CLA. Biologically active isomers of CLA ( cis -9, trans -11 (C18:2 and trans- 10, cis- 12 (C18:2 have been reported to have anticarcinogenic, antioxidative and antiatherosclerotic properties. Relatively rich sources of CLA include milk fat-containing foods such as kaymak. Kaymak is a kind of concentrated cream which is traditionally manufactured from buffalo or cow's milk mainly in Turkey . The objective of this study was to determine CLA concentrations during kaymak production. Kaymak was manufactured from cow's milk which was enriched with unfermented cream. Biologically active isomers of CLA in raw milk, cream and kaymak were analyzed using gas chromatography. The method was quick, repeatable and sensitive for the CLA determination of samples. Significant differences were found among the concentrations of both isomer and total CLA during the production process (pNumerosos efectos fisiológicos se atribuyen a los ácidos linoleico conjugados (CLA. Así los isómeros biológicamente activos ( cis -9, trans -11 (C18:2 y trans- 10, cis del ácido linoleico han sido descritos con propiedades anticarcinogénicas, antioxidantes y antiarterioscleróticas. Fuentes relativamente ricas de CLA incluyen alimentos con grasas lácteas tales como el kaymak. El kaymak es una crema concentrada elaborada de leche de búfalo o vaca principalmente en Turquía. El objetivo de este estudio fue la determinación de la concentración de CLA durante la producción de kaymak. El kaymak objeto de estudio fue elaborado a partir de leche de vaca que fue enriquecida con crema no fermentada. Los isómeros biológicamente activos del CLA fueron analizados por cromatografía gaseosa en leche cruda, crema y kaymak. El método empleado fue rápido, reproducible y sensible. Se encontraron diferencias significativas en las concentraciones de ambos isómeros y de CLA total durante el proceso de producci

Simulation-Based Prediction of Equivalent Continuous Noises during Construction Processes.

Science.gov (United States)

Zhang, Hong; Pei, Yun

2016-08-12

Quantitative prediction of construction noise is crucial to evaluate construction plans to help make decisions to address noise levels. Considering limitations of existing methods for measuring or predicting the construction noise and particularly the equivalent continuous noise level over a period of time, this paper presents a discrete-event simulation method for predicting the construction noise in terms of equivalent continuous level. The noise-calculating models regarding synchronization, propagation and equivalent continuous level are presented. The simulation framework for modeling the noise-affected factors and calculating the equivalent continuous noise by incorporating the noise-calculating models into simulation strategy is proposed. An application study is presented to demonstrate and justify the proposed simulation method in predicting the equivalent continuous noise during construction. The study contributes to provision of a simulation methodology to quantitatively predict the equivalent continuous noise of construction by considering the relevant uncertainties, dynamics and interactions.

Getting Back to Basics (& Acidics)

Science.gov (United States)

Rhodes, Sam

2006-01-01

This article describes a few novel acid-base experiments intended to introduce students to the basic concepts of acid-base chemistry and provide practical examples that apply directly to the study of biology and the human body. Important concepts such as the reaction between carbon dioxide and water, buffers and protein denaturation, are covered.…

Random poly(amino acid)s synthesized by ring opening polymerization as additives in the biomimetic mineralization of CaCO3

NARCIS (Netherlands)

Dmitrovic, V.; Habraken, G.J.M.; Hendrix, M.M.R.M.; Habraken, W.J.E.M.; Heise, A.; With, de G.; Sommerdijk, N.A.J.M.

2012-01-01

Biominerals such as bones, teeth and seashells, very often have advanced material properties and are a source of inspiration for material chemists. As in biological systems acidic proteins play an important role in regulating the formation of CaCO3 biominerals, we employ poly(amino acid)s to mimic

Verification of an effective dose equivalent model for neutrons

International Nuclear Information System (INIS)

Tanner, J.E.; Piper, R.K.; Leonowich, J.A.; Faust, L.G.

1992-01-01

Since the effective dose equivalent, based on the weighted sum of organ dose equivalents, is not a directly measurable quantity, it must be estimated with the assistance of computer modelling techniques and a knowledge of the incident radiation field. Although extreme accuracy is not necessary for radiation protection purposes, a few well chosen measurements are required to confirm the theoretical models. Neutron doses and dose equivalents were measured in a RANDO phantom at specific locations using thermoluminescence dosemeters, etched track dosemeters, and a 1.27 cm (1/2 in) tissue-equivalent proportional counter. The phantom was exposed to a bare and a D 2 O-moderated 252 Cf neutron source at the Pacific Northwest Laboratory's Low Scatter Facility. The Monte Carlo code MCNP with the MIRD-V mathematical phantom was used to model the human body and to calculate the organ doses and dose equivalents. The experimental methods are described and the results of the measurements are compared with the calculations. (author)

The Application of Equivalence Theory to Advertising Translation

Institute of Scientific and Technical Information of China (English)

张颖

2017-01-01

Through analyzing equivalence theory, the author tries to find a solution to the problems arising in the process of ad?vertising translation. These problems include cultural diversity, language diversity and special requirement of advertisement. The author declares that Nida''s functional equivalence is one of the most appropriate theories to deal with these problems. In this pa?per, the author introduces the principles of advertising translation and culture divergences in advertising translation, and then gives some advertising translation practices to explain and analyze how to create good advertising translation by using functional equivalence. At last, the author introduces some strategies in advertising translation.

The principle of equivalence

International Nuclear Information System (INIS)

Unnikrishnan, C.S.

1994-01-01

Principle of equivalence was the fundamental guiding principle in the formulation of the general theory of relativity. What are its key elements? What are the empirical observations which establish it? What is its relevance to some new experiments? These questions are discussed in this article. (author). 11 refs., 5 figs

Equivalent Colorings with "Maple"

Science.gov (United States)

Cecil, David R.; Wang, Rongdong

2005-01-01

Many counting problems can be modeled as "colorings" and solved by considering symmetries and Polya's cycle index polynomial. This paper presents a "Maple 7" program link http://users.tamuk.edu/kfdrc00/ that, given Polya's cycle index polynomial, determines all possible associated colorings and their partitioning into equivalence classes. These…

Lipschitz equivalence of self-similar sets with touching structures

International Nuclear Information System (INIS)

Ruan, Huo-Jun; Wang, Yang; Xi, Li-Feng

2014-01-01

Lipschitz equivalence of self-similar sets is an important area in the study of fractal geometry. It is known that two dust-like self-similar sets with the same contraction ratios are always Lipschitz equivalent. However, when self-similar sets have touching structures the problem of Lipschitz equivalence becomes much more challenging and intriguing at the same time. So far, all the known results only cover self-similar sets in R with no more than three branches. In this study we establish results for the Lipschitz equivalence of self-similar sets with touching structures in R with arbitrarily many branches. Key to our study is the introduction of a geometric condition for self-similar sets called substitutable. (paper)

Estimating water equivalent snow depth from related meteorological variables

International Nuclear Information System (INIS)

Steyaert, L.T.; LeDuc, S.K.; Strommen, N.D.; Nicodemus, M.L.; Guttman, N.B.

1980-05-01

Engineering design must take into consideration natural loads and stresses caused by meteorological elements, such as, wind, snow, precipitation and temperature. The purpose of this study was to determine a relationship of water equivalent snow depth measurements to meteorological variables. Several predictor models were evaluated for use in estimating water equivalent values. These models include linear regression, principal component regression, and non-linear regression models. Linear, non-linear and Scandanavian models are used to generate annual water equivalent estimates for approximately 1100 cooperative data stations where predictor variables are available, but which have no water equivalent measurements. These estimates are used to develop probability estimates of snow load for each station. Map analyses for 3 probability levels are presented

Dissolution of Simulated and Radioactive Savannah River Site High-Level Waste Sludges with Oxalic Acid & Citric Acid Solutions

International Nuclear Information System (INIS)

STALLINGS, MARY

2004-01-01

This report presents findings from tests investigating the dissolution of simulated and radioactive Savannah River Site sludges with 4 per cent oxalic acid and mixtures of oxalic and citric acid previously recommended by a Russian team from the Khlopin Radium Institute and the Mining and Chemical Combine (MCC). Testing also included characterization of the simulated and radioactive waste sludges. Testing results showed the following: Dissolution of simulated HM and PUREX sludges with oxalic and citric acid mixtures at SRTC confirmed general trends reported previously by Russian testing. Unlike the previous Russian testing six sequential contacts of a mixture of oxalic acid citric acids at a 2:1 ratio (v/w) of acid to sludge did not produce complete dissolution of simulated HM and PUREX sludges. We observed that increased sludge dissolution occurred at a higher acid to sludge ratio, 50:1 (v/w), compared to the recommended ratio of 2:1 (v/w). We observed much lower dissolution of aluminum in a simulated HM sludge by sodium hydroxide leaching. We attribute the low aluminum dissolution in caustic to the high fraction of boehmite present in the simulated sludge. Dissolution of HLW sludges with 4 per cent oxalic acid and oxalic/citric acid followed general trends observed with simulated sludges. The limited testing suggests that a mixture of oxalic and citric acids is more efficient for dissolving HM and PUREX sludges and provides a more homogeneous dissolution of HM sludge than oxalic acid alone. Dissolution of HLW sludges in oxalic and oxalic/citric acid mixtures produced residual sludge solids that measured at higher neutron poison to equivalent 235U weight ratios than that in the untreated sludge solids. This finding suggests that residual solids do not present an increased nuclear criticality safety risk. Generally the neutron poison to equivalent 235U weight ratios of the acid solutions containing dissolved sludge components are lower than those in the untreated

A bicategorical approach to Morita equivalence for Von Neumann algebras

NARCIS (Netherlands)

R.M. Brouwer (Rachel)

2003-01-01

textabstractWe relate Morita equivalence for von Neumann algebras to the ``Connes fusion'' tensor product between correspondences. In the purely algebraic setting, it is well known that rings are Morita equivalent if and only if they are equivalent objects in a bicategory whose 1-cells are

The relative biological effectiveness of out-of-field dose

International Nuclear Information System (INIS)

Balderson, Michael; Koger, Brandon; Kirkby, Charles

2016-01-01

Purpose: using simulations and models derived from existing literature, this work investigates relative biological effectiveness (RBE) for out-of-field radiation and attempts to quantify the relative magnitudes of different contributing phenomena (spectral, bystander, and low dose hypersensitivity effects). Specific attention is paid to external beam radiotherapy treatments for prostate cancer. Materials and methods: using different biological models that account for spectral, bystander, and low dose hypersensitivity effects, the RBE was calculated for different points moving radially out from isocentre for a typical single arc VMAT prostate case. The RBE was found by taking the ratio of the equivalent dose with the physical dose. Equivalent doses were calculated by determining what physical dose would be necessary to produce the same overall biological effect as that predicted using the different biological models. Results: spectral effects changed the RBE out-of-field less than 2%, whereas response models incorporating low dose hypersensitivity and bystander effects resulted in a much more profound change of the RBE for out-of-field doses. The bystander effect had the largest RBE for points located just outside the edge of the primary radiation beam in the cranial caudal (z-direction) compared to low dose hypersensitivity and spectral effects. In the coplanar direction, bystander effect played the largest role in enhancing the RBE for points up to 8.75 cm from isocentre. Conclusions: spectral, bystander, and low dose hypersensitivity effects can all increase the RBE for out-of-field radiation doses. In most cases, bystander effects seem to play the largest role followed by low dose hypersensitivity. Spectral effects were unlikely to be of any clinical significance. Bystander, low dose hypersensitivity, and spectral effect increased the RBE much more in the cranial caudal direction (z-direction) compared with the coplanar directions. (paper)

Environmental analysis of plastic production processes: comparing petroleum-based polypropylene and polyethylene with biologically-based poly-beta-hydroxybutyric acid using life cycle analysis.

Science.gov (United States)

Harding, K G; Dennis, J S; von Blottnitz, H; Harrison, S T L

2007-05-31

Polymers based on olefins have wide commercial applicability. However, they are made from non-renewable resources and are characterised by difficulty in disposal where recycle and re-use is not feasible. Poly-beta-hydroxybutyric acid (PHB) provides one example of a polymer made from renewable resources. Before motivating its widespread use, the advantages of a renewable polymer must be weighed against the environmental aspects of its production. Previous studies relating the environmental impacts of petroleum-based and bio-plastics have centred on the impact categories of global warming and fossil fuel depletion. Cradle-to-grave studies report equivalent or reduced global warming impacts, in comparison to equivalent polyolefin processes. This stems from a perceived CO(2) neutral status of the renewable resource. Indeed, no previous work has reported the results of a life cycle assessment (LCA) giving the environmental impacts in all major categories. This study investigates a cradle-to-gate LCA of PHB production taking into account net CO(2) generation and all major impact categories. It compares the findings with similar studies of polypropylene (PP) and polyethylene (PE). It is found that, in all of the life cycle categories, PHB is superior to PP. Energy requirements are slightly lower than previously observed and significantly lower than those for polyolefin production. PE impacts are lower than PHB values in acidification and eutrophication.

Biological activities of organic extracts of four Aureobasidium pullulans varieties isolated from extreme marine and terrestrial habitats.

Science.gov (United States)

Botić, Tanja; Kralj-Kunčič, Marjetka; Sepčić, Kristina; Batista, Urška; Zalar, Polona; Knez, Željko; Gunde-Cimerman, Nina

2014-01-01

We report on the screening for biological activities of organic extracts from seven strains that represent four varieties of the fungus Aureobasidium pullulans, that is A. pullulans var. melanogenum, A. pullulans var. pullulans, A. pullulans var. subglaciale and A. pullulans var. namibiae. We monitored haemolysis, cytotoxicity, antioxidant capacity and growth inhibition against three bacterial species. The haemolytic activity of A. pullulans var. pullulans EXF-150 strain was due to five different haemolytically active fractions. Extracts from all of the other varieties contained at least one haemolytically active fraction. Short-term exposure of cell lines to these haemolytically active organic extracts resulted in more than 95% cytotoxicity. Strong antioxidant capacity, corresponding to 163.88 μg ascorbic acid equivalent per gram of total solid, was measured in the organic extract of the strain EXF-3382, obtained from A. pullulans var. melanogenum, isolated from the deep sea. Organic extracts from selected varieties of A. pullulans exhibited weak antibacterial activities.

Synthesis of new fatty acids amides from aminolysis of fatty acid methyl esters (FAMEs)

International Nuclear Information System (INIS)

Lopes, Carolina R.; Montes D'Oca, Caroline da Ros; Duarte, Rodrigo da C.; Kurz, Marcia H.S.; Primel, Ednei G.; Clementin, Rosilene M.; Villarreyes, Joaquin Ariel M.; Montes D'Oca, Marcelo G.

2010-01-01

Recent biochemical and pharmacological studies have led to the characterization of different fatty acid amides as a new family of biologically active lipids. Here, we describe the synthesis of new amides from C16:0, 18:0, 18:1 and 18:1, OH fatty acids (FFA) families with cyclic and acyclic amines and demonstrate for the first time that these compounds produce cytotoxic effects. Application of this method to the synthesis of fatty acid amides was performed using the esters aminolysis as a key step and various carboxylic amides were prepared in good yield from fatty acid methyl esters (FAMEs). (author)

Potential of wild plants as a source of bioactive compounds

Directory of Open Access Journals (Sweden)

Eva Ivanišová

2017-05-01

Results showed that wild plants are rich for biologically active substances and can be used more in different kind of industry as a cheap source of these substances. The highest antioxidant activity by ABTS and reducing power method was determined in the sample of Menyanthes trifoliata L. (64.99 mg TEAC – Trolox equivalent antioxidant capacity per g of sample and 69.05 mg TEAG per g and by phosphomolybdenum method in the sample of Menyanthes trifoliata L. (237.97 mg TEAC per g of sample. In the sample of Menyanthes trifoliata L. was measured the highest content of total polyphenols (27.91 mg GAE – gallic acid equivalent per g of sample, flavonoids (35.69 mg QE – quercetin equivalent per g of sample and total phenolic acids (22.56 mg CAE – caffeic acid equivalent per g of sample. All samples also showed antimicrobial activity to inhibit selected kind bacteria with the best results in Menyanthes trifoliata L.

Folic acid derivatives for use in radioimmunoassay

International Nuclear Information System (INIS)

Ali, A.

1981-01-01

The chemical preparation of two folic acid derivatives, labelled with 125 I or 131 I, is described for use in radioimmunoassay of folic acid and its metabolites in biological fluids such as blood serum. Labelled compounds of the present invention more closely resemble folic acid in that they have glutamic acid in the terminal position. Examples of the use of these compounds in three different assays are given. (U.K.)

Biological treatment of acid mine water: selection of a biomass population enriched in sulphate-reducing bacteria; Tratamiento biologico de aguas acidas de mineria: seleccion de una poblacion bacteriana enriquecida en bacterias sulfatoreductoras

Energy Technology Data Exchange (ETDEWEB)

Duran Barrantes, M. M.; Jimenez Rodriguez, A. M.; Martel Villagran, F. J.

2001-07-01

The purpose of this work is to study the biological sulphate reduction. AYESA (Aguas y Estructuras, S. A.) is developing the technical attendance. This study is being demonstrated under the Acid Water Treatment Program, conducted by the Consejeria del Medio Ambiente (Junta de Andalucia). Acid mine drainage is one of the most serious environmental problems facing the metal mining industry. This wastewater is formed when sulphide ores undergo chemical and biological oxidation processes and is characterized by low pH-values and high levels of sulphate and metals. The effect of stimuling bacteria sulphate reduction in such systems in order to improve water quality was examined in a laboratory scale experiment, in 250 mL, magnetically stirred, batch, anaerobic reactors, to 25 degree centigree. (Author) 11 refs.

Azadirachtin interacts with retinoic acid receptors and inhibits retinoic acid-mediated biological responses.

Science.gov (United States)

Thoh, Maikho; Babajan, Banaganapalli; Raghavendra, Pongali B; Sureshkumar, Chitta; Manna, Sunil K

2011-02-11

Considering the role of retinoids in regulation of more than 500 genes involved in cell cycle and growth arrest, a detailed understanding of the mechanism and its regulation is useful for therapy. The extract of the medicinal plant Neem (Azadirachta indica) is used against several ailments especially for anti-inflammatory, anti-itching, spermicidal, anticancer, and insecticidal activities. In this report we prove the detailed mechanism on the regulation of retinoic acid-mediated cell signaling by azadirachtin, active components of neem extract. Azadirachtin repressed all trans-retinoic acid (ATRA)-mediated nuclear transcription factor κB (NF-κB) activation, not the DNA binding but the NF-κB-dependent gene expression. It did not inhibit IκBα degradation, IκBα kinase activity, or p65 phosphorylation and its nuclear translocation but inhibited NF-κB-dependent reporter gene expression. Azadirachtin inhibited TRAF6-mediated, but not TRAF2-mediated NF-κB activation. It inhibited ATRA-induced Sp1 and CREB (cAMP-response element-binding protein) DNA binding. Azadirachtin inhibited ATRA binding with retinoid receptors, which is supported by biochemical and in silico evidences. Azadirachtin showed strong interaction with retinoid receptors. It suppressed ATRA-mediated removal of retinoid receptors, bound with DNA by inhibiting ATRA binding to its receptors. Overall, our data suggest that azadirachtin interacts with retinoic acid receptors and suppresses ATRA binding, inhibits falling off the receptors, and activates transcription factors like CREB, Sp1, NF-κB, etc. Thus, azadirachtin exerts anti-inflammatory and anti-metastatic responses by a novel pathway that would be beneficial for further anti-inflammatory and anti-cancer therapies.

Azadirachtin Interacts with Retinoic Acid Receptors and Inhibits Retinoic Acid-mediated Biological Responses*

Science.gov (United States)

Thoh, Maikho; Babajan, Banaganapalli; Raghavendra, Pongali B.; Sureshkumar, Chitta; Manna, Sunil K.

2011-01-01

Considering the role of retinoids in regulation of more than 500 genes involved in cell cycle and growth arrest, a detailed understanding of the mechanism and its regulation is useful for therapy. The extract of the medicinal plant Neem (Azadirachta indica) is used against several ailments especially for anti-inflammatory, anti-itching, spermicidal, anticancer, and insecticidal activities. In this report we prove the detailed mechanism on the regulation of retinoic acid-mediated cell signaling by azadirachtin, active components of neem extract. Azadirachtin repressed all trans-retinoic acid (ATRA)-mediated nuclear transcription factor κB (NF-κB) activation, not the DNA binding but the NF-κB-dependent gene expression. It did not inhibit IκBα degradation, IκBα kinase activity, or p65 phosphorylation and its nuclear translocation but inhibited NF-κB-dependent reporter gene expression. Azadirachtin inhibited TRAF6-mediated, but not TRAF2-mediated NF-κB activation. It inhibited ATRA-induced Sp1 and CREB (cAMP-response element-binding protein) DNA binding. Azadirachtin inhibited ATRA binding with retinoid receptors, which is supported by biochemical and in silico evidences. Azadirachtin showed strong interaction with retinoid receptors. It suppressed ATRA-mediated removal of retinoid receptors, bound with DNA by inhibiting ATRA binding to its receptors. Overall, our data suggest that azadirachtin interacts with retinoic acid receptors and suppresses ATRA binding, inhibits falling off the receptors, and activates transcription factors like CREB, Sp1, NF-κB, etc. Thus, azadirachtin exerts anti-inflammatory and anti-metastatic responses by a novel pathway that would be beneficial for further anti-inflammatory and anti-cancer therapies. PMID:21127062

4-Methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic Acid. Peculiarities of Preparation, Structure, and Biological Properties

Directory of Open Access Journals (Sweden)

Igor V. Ukrainets

2018-03-01

Full Text Available In order to determine the regularities of the structure–analgesic activity relationship, the peculiarities of obtaining, the spatial structure, and biological properties of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid and some of its derivatives have been studied. Using nuclear magnetic resonance (NMR spectroscopy and X-ray diffraction analysis, it has been proven that varying the reaction conditions using alkaline hydrolysis of methyl 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate makes it possible to successfully synthesize a monohydrate of the target acid, its sodium salt, or 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine. The derivatographic study of the thermal stability of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid monohydrate has been carried out; based on this study, the optimal conditions completely eliminating the possibility of unwanted decomposition have been proposed for obtaining its anhydrous form. It has been shown that 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine is easily formed during the decarboxylation of not only 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid, but also its sodium salt, which is capable of losing СО2 both in rather soft conditions of boiling in an aqueous solution, and in more rigid conditions of dry heating. The NMR spectra of the compounds synthesized are given; their spatial structure is discussed. To study the biological properties of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid and its sodium salt, the experimental model of inflammation caused by subplantar introduction of the carrageenan solution in one of the hind limbs of white rats was used. The anti-inflammatory activity and analgesic effect were assessed by the degree of edema reduction and the ability to affect the pain response compared to the animals of control groups. According to the results of the tests performed, it has been found that after intraperitoneal injection

Ellagic Acid: A Logical Lead for Drug Development?

Science.gov (United States)

Shakeri, Abolfazl; Zirak, Mohammad Reza; Sahebkar, Amirhossein

2018-01-01

Naturally occurring polyphenols are the subject of increasing attention due to their potent antioxidant activity and their marked effects on the prevention of various oxidative stress-associated diseases such as cancer. Ellagic acid (EA) is an herbal polyphenol that is structurally a condensed dimer of gallic acid. This review aims to provide a comprehensive and updated overview on the biological activities of EA and potential therapeutic applications. EA is found in fruits and nuts, either in the combined form with hexahydroxydiphenic acid or in the bound form (ellagitannins). EA exhibits many biological properties such as antioxidant, anti-diabetic, anticancer and apoptosis-inducing activities. These biological and pharmacological properties are relevant to the treatment of several human diseases. Owing to its multiple mechanisms of action, EA represents a potential therapeutic agent against human diseases particularly cancer. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Mutation-induced quisqualic acid and ibotenic acid affinity at the metabotropic glutamate receptor subtype 4: ligand selectivity results from a synergy of several amino acid residues

DEFF Research Database (Denmark)

Hermit, Mette B; Greenwood, Jeremy R; Bräuner-Osborne, Hans

2004-01-01

The metabotropic glutamate receptors (mGluRs) are key modulators of excitatory neurotransmission in the central nervous system. The eight mGluR subtypes are seven trans-membrane-spanning proteins that possess a large extracellular amino-terminal domain in which the endogenous ligand binding pocket...... resides. In this study, we have identified four non-conserved amino acid residues that are essential for differentiating mGluR1 from mGluR4. Our approach has been to increase the affinity of the classic mGluR1 agonists, quisqualic acid and ibotenic acid, at mGluR4 by making various point mutations......, the mutations K74Y and K317R induced dramatic triple-order-of-magnitude increases in the affinity of ibotenic acid at mGluR4, making the affinity equivalent to that of mGluR1. Furthermore, the affinity of quisqualic acid at mGluR4 was increased to the same level as mGluR1 by the two double mutations, K74Y/K317R...

Pros and cons of fatty acids in bone biology.

Science.gov (United States)

Wauquier, Fabien; Léotoing, Laurent; Philippe, Claire; Spilmont, Mélanie; Coxam, Véronique; Wittrant, Yohann

2015-04-01

Despite the growing interest in deciphering the causes and consequences of obesity-related disorders, the mechanisms linking fat intake to bone behaviour remain unclear. Since bone fractures are widely associated with increased morbidity and mortality, most notably in elderly and obese people, bone health has become a major social and economic issue. Consistently, public health system guidelines have encouraged low-fat diets in order to reduce associated complications. However, from a bone point of view, mechanisms linking fat intake to bone alteration remain quite controversial. Thus, after more than a decade of dedicated studies, this timely review offers a comprehensive overview of the relationships between bone and fatty acids. Using clinical evidences as a starting-point to more complex molecular elucidation, this work highlights the complexity of the system and reveals that bone alteration that cannot be solved simply by taking ω-3 pills. Fatty acid effects on bone metabolism can be both direct and indirect and require integrated investigations. Furthermore, even at the level of a single cell, one fatty acid is able to trigger several different independent pathways (receptors, metabolites…) which may all have a say in the final cellular metabolic response. Copyright © 2015 Elsevier Ltd. All rights reserved.

DATABASES DEVELOPED IN INDIA FOR BIOLOGICAL SCIENCES

Directory of Open Access Journals (Sweden)

Gitanjali Yadav

2017-09-01

Full Text Available The complexity of biological systems requires use of a variety of experimental methods with ever increasing sophistication to probe various cellular processes at molecular and atomic resolution. The availability of technologies for determining nucleic acid sequences of genes and atomic resolution structures of biomolecules prompted development of major biological databases like GenBank and PDB almost four decades ago. India was one of the few countries to realize early, the utility of such databases for progress in modern biology/biotechnology. Department of Biotechnology (DBT, India established Biotechnology Information System (BTIS network in late eighties. Starting with the genome sequencing revolution at the turn of the century, application of high-throughput sequencing technologies in biology and medicine for analysis of genomes, transcriptomes, epigenomes and microbiomes have generated massive volumes of sequence data. BTIS network has not only provided state of the art computational infrastructure to research institutes and universities for utilizing various biological databases developed abroad in their research, it has also actively promoted research and development (R&D projects in Bioinformatics to develop a variety of biological databases in diverse areas. It is encouraging to note that, a large number of biological databases or data driven software tools developed in India, have been published in leading peer reviewed international journals like Nucleic Acids Research, Bioinformatics, Database, BMC, PLoS and NPG series publication. Some of these databases are not only unique, they are also highly accessed as reflected in number of citations. Apart from databases developed by individual research groups, BTIS has initiated consortium projects to develop major India centric databases on Mycobacterium tuberculosis, Rice and Mango, which can potentially have practical applications in health and agriculture. Many of these biological

Biological treatment of inorganic ion contamination including radionuclides

Energy Technology Data Exchange (ETDEWEB)

Cherry, R S [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

1997-12-01

Microorganisms and plants are capable of a broad range of activities useful in treating inorganic contaminants in soil, groundwater, and surface runoff water Among the advantages of biological processes for this purpose are relatively low costs (related to their mild conditions) and the practicality of letting them run unattended. This talk will review both kinds of treatment chemistry that can be done biologically as well as present data from INEEL projects on bioremediation of specific elements. Biological processes can either solubilize or immobilize metals and other ions depending on the need. Uranium ions are solubilized from soil by the local bioproduction of organic acids as chelating agents, allowing removal of this ion as part of an ex-situ treatment process. Further, the microbial production of sulfuric acid can be used to solubilize Cs contamination in concrete surfaces. More usual though is the need to control metal movement in soil or water. Various metals such as Se and Cd are taken up from soil by hyper-accumulating plants, where they can be harvested in concentrated form in the leaves and stems. Excess acidity and a broad variety of toxic metals in acid rock drainage, such as Hg, Cd, Zn and others, can be removed by the production of sulfide ion in an easily fielded biological reactor which may be useful on phosphate processing runoff water contaminated with naturally occuring radioactive materials. Soluble Co, Cu, and Cd can be treated by sorption onto immobilized algae. Inorganic ions can also be directly reduced by bacteria as part of treatment, for example the conversion of soluble selenate ion to insoluble elemental selenium and the conversion of highly toxic CR(VI) to the far less soluble and less toxic Cr(III).

Biological treatment of inorganic ion contamination including radionuclides

International Nuclear Information System (INIS)

Cherry, R.S.

1997-01-01

Microorganisms and plants are capable of a broad range of activities useful in treating inorganic contaminants in soil, groundwater, and surface runoff water Among the advantages of biological processes for this purpose are relatively low costs (related to their mild conditions) and the practicality of letting them run unattended. This talk will review both kinds of treatment chemistry that can be done biologically as well as present data from INEEL projects on bioremediation of specific elements. Biological processes can either solubilize or immobilize metals and other ions depending on the need. Uranium ions are solubilized from soil by the local bioproduction of organic acids as chelating agents, allowing removal of this ion as part of an ex-situ treatment process. Further, the microbial production of sulfuric acid can be used to solubilize Cs contamination in concrete surfaces. More usual though is the need to control metal movement in soil or water. Various metals such as Se and Cd are taken up from soil by hyper-accumulating plants, where they can be harvested in concentrated form in the leaves and stems. Excess acidity and a broad variety of toxic metals in acid rock drainage, such as Hg, Cd, Zn and others, can be removed by the production of sulfide ion in an easily fielded biological reactor which may be useful on phosphate processing runoff water contaminated with naturally occuring radioactive materials. Soluble Co, Cu, and Cd can be treated by sorption onto immobilized algae. Inorganic ions can also be directly reduced by bacteria as part of treatment, for example the conversion of soluble selenate ion to insoluble elemental selenium and the conversion of highly toxic CR(VI) to the far less soluble and less toxic Cr(III)

Bisimulation Meet PCTL Equivalences for Probabilistic Automata (Journal Version)

DEFF Research Database (Denmark)

Song, Lei; Zhang, Lijun; Godskesen, Jens Christian

2013-01-01

Probabilistic automata (PA) have been successfully applied in the formal verification of concurrent and stochastic systems. Efficient model checking algorithms have been studied, where the most often used logics for expressing properties are based on PCTL and its extension PCTL*. Various behavioral...... equivalences are proposed for PAs, as a powerful tool for abstraction and compositional minimization for PAs. Unfortunately, the behavioral equivalences are well-known to be strictly stronger than the logical equivalences induced by PCTL or PCTL*. This paper introduces novel notions of strong bisimulation...... relations, which characterizes PCTL and PCTL* exactly. We also extend weak bisimulations characterizing PCTL and PCTL* without next operator, respectively. Thus, our paper bridges the gap between logical and behavioral equivalences in this setting....

Uric acid in plants and microorganisms: Biological applications and genetics - A review.

Science.gov (United States)

Hafez, Rehab M; Abdel-Rahman, Tahany M; Naguib, Rasha M

2017-09-01

Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing) of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.

Uric acid in plants and microorganisms: Biological applications and genetics - A review

Directory of Open Access Journals (Sweden)

Rehab M. Hafez

2017-09-01

Full Text Available Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.

Modelling of dynamic equivalents in electric power grids

International Nuclear Information System (INIS)

Craciun, Diana Iuliana

2010-01-01

In a first part, this research thesis proposes a description of the context and new constraints of electric grids: architecture, decentralized production with the impact of distributed energy resource systems, dynamic simulation, and interest of equivalent models. Then, the author discusses the modelling of the different components of electric grids: synchronous and asynchronous machines, distributed energy resource with power electronic interface, loading models. She addresses the techniques of reduction of electric grid models: conventional reduction methods, dynamic equivalence methods using non linear approaches or evolutionary algorithm-based methods of assessment of parameters. This last approach is then developed and implemented, and a new method of computation of dynamic equivalents is described

The experimental method for neutron dose-equivalent detection

International Nuclear Information System (INIS)

Ji Changsong

1992-01-01

A new method, for getting neutron dose-equivalent Cd rode absorption method is described. The method adopts Cd-rode-swarm buck absorption, which greatly improved the neutron sensitivity and simplified the adjustment method. By this method, the author has developed BH3105 model neutron dose equivalent meter, the sensitivity of this instrument reach 10 cps/μSvh -1 . γ-ray depression rate reaches 4000:1, the measurement range is 0.1 μSv/h-10 6 μSv/h. The energy response is good (from thermal neutron-14 MeV neutron), this instrument can be used to measure the dose equivalent of the neutron areas

Study of free acidity determinations in aqueous solution

International Nuclear Information System (INIS)

Kergreis, A.

1966-04-01

The object of this work is the study of the principal methods which can be applied to the measurement of 'free' acidity. In the first part, we define the various types of acidity which can exist in aqueous solution; then, after having studied some hydrolysis reactions, we compare the value of the neutralisation pH of the hydrated cation and that of the precipitation of the hydroxide. In the second part we have started to study the determination of the acidity of an aqueous solution. After having rapidly considered the 'total' acidity determination, we deal with the problem of the 'free' acidity titration. We have considered in particular certain methods: extrapolation of the equivalent point, colorimetric titrations with or without a complexing agent, and finally the use of ion-exchange resins with mixed aqueous and solvent solutions. (author) [fr

Equivalence of quantum states under local unitary transformations

International Nuclear Information System (INIS)

Fei Shaoming; Jing Naihuan

2005-01-01

In terms of the analysis of fixed point subgroup and tensor decomposability of certain matrices, we study the equivalence of quantum bipartite mixed states under local unitary transformations. For non-degenerate case an operational criterion for the equivalence of two such mixed bipartite states under local unitary transformations is presented

Selection of Clostridium spp. in biological sand filters neutralizing synthetic acid mine drainage.

Science.gov (United States)

Ramond, Jean-Baptiste; Welz, Pamela J; Le Roes-Hill, Marilize; Tuffin, Marla I; Burton, Stephanie G; Cowan, Don A

2014-03-01

In this study, three biological sand filter (BSF) were contaminated with a synthetic iron- [1500 mg L⁻¹ Fe(II), 500 mg L⁻¹ Fe(III)] and sulphate-rich (6000 mg L⁻¹ SO₄²⁻) acid mine drainage (AMD) (pH = 2), for 24 days, to assess the remediation capacity and the evolution of autochthonous bacterial communities (monitored by T-RFLP and 16S rRNA gene clone libraries). To stimulate BSF bioremediation involving sulphate-reducing bacteria, a readily degradable carbon source (glucose, 8000 mg L⁻¹) was incorporated into the influent AMD. Complete neutralization and average removal efficiencies of 81.5 (±5.6)%, 95.8 (±1.2)% and 32.8 (±14.0)% for Fe(II), Fe(III) and sulphate were observed, respectively. Our results suggest that microbial iron reduction and sulphate reduction associated with iron precipitation were the main processes contributing to AMD neutralization. The effect of AMD on BSF sediment bacterial communities was highly reproducible. There was a decrease in diversity, and notably a single dominant operational taxonomic unit (OTU), closely related to Clostridium beijerinckii, which represented up to 65% of the total community at the end of the study period. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Verification of an effective dose equivalent model for neutrons

International Nuclear Information System (INIS)

Tanner, J.E.; Piper, R.K.; Leonowich, J.A.; Faust, L.G.

1991-10-01

Since the effective dose equivalent, based on the weighted sum of organ dose equivalents, is not a directly measurable quantity, it must be estimated with the assistance of computer modeling techniques and a knowledge of the radiation field. Although extreme accuracy is not necessary for radiation protection purposes, a few well-chosen measurements are required to confirm the theoretical models. Neutron measurements were performed in a RANDO phantom using thermoluminescent dosemeters, track etch dosemeters, and a 1/2-in. (1.27-cm) tissue equivalent proportional counter in order to estimate neutron doses and dose equivalents within the phantom at specific locations. The phantom was exposed to bare and D 2 O-moderated 252 Cf neutrons at the Pacific Northwest Laboratory's Low Scatter Facility. The Monte Carlo code MCNP with the MIRD-V mathematical phantom was used to model the human body and calculate organ doses and dose equivalents. The experimental methods are described and the results of the measurements are compared to the calculations. 8 refs., 3 figs., 3 tabs

Inertia and Double Bending of Light from Equivalence

Science.gov (United States)

Shuler, Robert L., Jr.

2010-01-01

Careful examination of light paths in an accelerated reference frame, with use of Special Relativity, can account fully for the observed bending of light in a gravitational field, not just half of it as reported in 1911. This analysis also leads to a Machian formulation of inertia similar to the one proposed by Einstein in 1912 and later derived from gravitational field equations in Minkowsky Space by Sciama in 1953. There is a clear inference from equivalence that there is some type of inertial mass increase in a gravitational field. It is the purpose of the current paper to suggest that equivalence provides a more complete picture of gravitational effects than previously thought, correctly predicting full light bending, and that since the theory of inertia is derivable from equivalence, any theory based on equivalence must take account of it. Einstein himself clearly was not satisfied with the status of inertia in GRT, as our quotes have shown. Many have tried to account for inertia and met with less than success, for example Davidson s integration of Sciama s inertia into GRT but only for a steady state cosmology [10], and the Machian gravity theory of Brans and Dicke [11]. Yet Mach s idea hasn t gone away, and now it seems that it cannot go away without also disposing of equivalence.

Why the Central Dogma: on the nature of the great biological exclusion principle.

Science.gov (United States)

Koonin, Eugene V

2015-09-16

The Central Dogma of molecular biology posits that transfer of information from proteins back to nucleic acids does not occur in biological systems. I argue that the impossibility of reverse translation is indeed a major, physical exclusion principle that emerges due to the transition from the digital information carriers, nucleic acids, to analog information carriers, proteins, which involves irreversible suppression of the digital information.

Novel and rare prenyllipids - Occurrence and biological activity.

Science.gov (United States)

Szymańska, Renata; Kruk, Jerzy

2018-01-01

The data presented indicate that there is a variety of unique prenyllipids, often of very limited taxonomic distribution, whose origin, biosynthesis, metabolism and biological function deserves to be elucidated. These compounds include tocoenols, tocochromanol esters, tocochromanol acids, plastoquinones and ubiquinones. Additionally, based on the available data, it can be assumed that there are still unrecognized prenyllipids, like prenylquinols fatty acid esters of the hydroquinone ring, including prenylquinol phosphates, and others, whose biological function might be of great importance. Our knowledge of these compounds is not only important from the scientific point of view, but may also be of practical significance to medicine, pharmacy or cosmetics. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The transfer of Cfunc contextual control through equivalence relations.

Science.gov (United States)

Perez, William F; Fidalgo, Adriana P; Kovac, Roberta; Nico, Yara C

2015-05-01

Derived relational responding is affected by contextual stimuli (Cfunc) that select specific stimulus functions. The present study investigated the transfer of Cfunc contextual control through equivalence relations by evaluating both (a) the maintenance of Cfunc contextual control after the expansion of a relational network, and (b) the establishment of novel contextual stimuli by the transfer of Cfunc contextual control through equivalence relations. Initially, equivalence relations were established and contingencies were arranged so that colors functioned as Cfunc stimuli controlling participants' key-pressing responses in the presence of any stimulus from a three-member equivalence network. To investigate the first research question, the three-member equivalence relations were expanded to five members and the novel members were presented with the Cfunc stimuli in the key-pressing task. To address the second goal of this study, the colors (Cfunc) were established as equivalent to certain line patterns. The transfer of contextual cue function (Cfunc) was tested replacing the colored backgrounds with line patterns in the key-pressing task. Results suggest that the Cfunc contextual control was transferred to novel stimuli that were added to the relational network. In addition, the line patterns indirectly acquired the contextual cue function (Cfunc) initially established for the colored backgrounds. The conceptual and applied implications of Cfunc contextual control are discussed. © Society for the Experimental Analysis of Behavior.

Lactic acid fermentation of crude sorghum extract

Energy Technology Data Exchange (ETDEWEB)

Samuel, W.A.; Lee, Y.Y.; Anthony, W.B.

1980-04-01

Crude extract from sweet sorghum supplemented with vetch juice was utilized as the carbohydrate source for fermentative production of lactic acid. Fermentation of media containing 7% (w/v) total sugar was completed in 60-80 hours by Lactobacillus plantarum, product yield averaging 85%. Maximum acid production rates were dependent on pH, initial substrate distribution, and concentration, the rates varying from 2 to 5 g/liter per hour. Under limited medium supplementation the lactic acid yield was lowered to 67%. The fermented ammoniated product contained over eight times as much equivalent crude protein (N x 6.25) as the original medium. Unstructured kinetic models were developed for cell growth, lactic acid formation, and substrate consumption in batch fermentation. With the provision of experimentally determined kinetic parameters, the proposed models accurately described the fermentation process. 15 references.

Prostaglandins and their receptors in insect biology

Directory of Open Access Journals (Sweden)

David eStanley

2011-12-01

Full Text Available We treat the biological significance of prostaglandins (PGs and their known receptors in insect biology. PGs and related eicosanoids are oxygenated derivatives of arachidonic acid (AA and two other C20 polyunsaturated fatty acids. PGs are mostly appreciated in the context of biomedicine, but a growing body of literature indicates the biological significance of these compounds extends throughout the animal kingdom, and possibly beyond. PGs act in several crucial areas of insect biology. In reproduction, a specific PG, PGE2, releases oviposition behavior in most crickets and a few other insect species; PGs also mediate events in egg development in some species, which may represent all insects. PGs play major roles in modulating fluid secretion in Malpighian tubules, rectum and salivary glands, although, again, this has been studied in only a few insect species that may represent the Class. Insect immunity is a very complex defense system. PGs and other eicosanoids mediate a large number of immune reactions to infection and invasion. The actions of most PGs are mediated by specific receptors. Biomedical research has discovered a great deal of knowledge about PG receptors in mammals, including their structures, pharmacology, molecular biology and cellular locations. Studies of PG receptors in insects lag behind the biomedical background, however, recent results hold the promise of accelerated research in this area. A PG receptor has been identified in a class of lepidopteran hemocytes and experimentally linked to the release of prophenoloxidase. We conclude that research into PGs and their receptors in insects will lead to important advances in our understanding of insect biology.

Crispoic acid, a new compound from Laelia marginata (Orchidaceae), and biological evaluations against parasites, human cancer cell lines and Zika virus.

Science.gov (United States)

Belloto, Andrezza C; Souza, Gredson K; Perin, Paula C; Schuquel, Ivania T A; Santin, Silvana M O; Chiavelli, Lucas U R; Garcia, Francielle P; Kaplum, Vanessa; Rodrigues, Jean H S; Scariot, Débora B; Delvecchio, Rodrigo; Machado-Ferreira, Erik; Santana Aguiar, Renato; Soares, Carlos A G; Nakamura, Celso V; Pomini, Armando M

2017-11-08

The phytochemical study of Laelia marginata (Lindl.) L. O. Williams (Orchidaceae) led to the isolation of a new natural product named crispoic acid (1), together with six other known compounds (2-7). The new natural product was identified as a dimer of eucomic acid and was structurally characterised based upon 1D and 2D NMR and HRMS data. Biological assays with plant crude extract, fractions and isolated compounds were performed against two human cancer cell lines (Hela and Siha), and the tropical parasites Trypanosoma cruzi and Leishmania (Leishmania) amazonensis. The phenantrenoid 9,10-dihydro-4-methoxyphenanthren-2,7-diol 2 was active against Hela and Siha cells (CC 50 5.86 ± 0.19 and 20.78 ± 2.72 μg/mL, respectively). Sub-lethal concentrations of the flavone rhamnazin 4 were not able to rescue the viability of the Vero cells infected by Zika virus.

10 CFR 20.1208 - Dose equivalent to an embryo/fetus.

Science.gov (United States)

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Dose equivalent to an embryo/fetus. 20.1208 Section 20... Limits § 20.1208 Dose equivalent to an embryo/fetus. (a) The licensee shall ensure that the dose equivalent to the embryo/fetus during the entire pregnancy, due to the occupational exposure of a declared...

Bibliography for acid-rock drainage and selected acid-mine drainage issues related to acid-rock drainage from transportation activities

Science.gov (United States)

Bradley, Michael W.; Worland, Scott C.

2015-01-01

Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS2) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.

A review on usnic acid, an interesting natural compound

Science.gov (United States)

Cocchietto, Moreno; Skert, Nicola; Nimis, Pier Luigi; Sava, Gianni

2002-03-01

Lichens are a world-widespread consortium of fungal and photosynthetic partners. Usnic acid is one of the most common and abundant lichen metabolites, well known as an antibiotic, but also endowed with several other interesting properties. This review summarises the most relevant studies on usnic acid, focusing on a number of biological activities in different fields. On the basis of the existing literature, usnic acid seems to be an exclusive lichen product. No synthetic derivatives more effective than the natural form are known. Both the (+) and (-) enantiomers of usnic acid are effective against a large variety of Gram-positive (G+) bacterial strains, including strains from clinical isolates, irrespective of their resistant phenotype. Of particular relevance is the inhibition of growth of multi-resistant strains of Streptococcus aureus, enterococci and mycobacteria. The (+)-usnic acid enantiomer appears to be selective against Streptococcus mutans without inducing perturbing side effects on the oral saprophyte flora. On the other hand, the (-)-usnic acid enantiomer is a selective natural herbicide because of its blocking action against a specific key plant enzyme. Other recognised characteristics of usnic acid are ultraviolet absorption and preserving properties. The toxicology, the in vitro anti-inflammatory effects and the mechanism of action of usnic acid need to be investigated in greater detail in order to reach clinical trials and to allow further applications. Furthermore, more research is needed to make possible intensive lichen culture, in order to produce large quantities of lichen substances for pharmaceutical, cosmetic and agricultural purposes. Some biological aspects, i.e. the possible biological roles of usnic acid, are discussed.

Molecularly imprinted polyaniline-ferrocene-sulfonic acid-Carbon dots modified pencil graphite electrodes for chiral selective sensing of D-Ascorbic acid and L-Ascorbic acid: A clinical biomarker for preeclampsia

International Nuclear Information System (INIS)

Pandey, Indu; Jha, Shashank Shekhar

2015-01-01

Highlights: • Pencil graphite electrode was non-covalently functionalized by C-dots. • Electrochemically synthesized ferrocene-sulfonic acid doped PANI film was used as chiral recognition element. • Electrochemical chiral sensing of L-ascorbic acid and D-ascorbic acid was carried out. • L-ascorbic acid determination was done in aqueous, biological and pharmaceutical samples at nM level. - Abstract: A simple and novel method is proposed for chiral separation of L-ascorbic acid and D-ascorbic acid in human cerebrospinal fluids and blood plasma samples. Electro-polymerized molecularly imprinted poly-aniline ferrocenesulfonic acid-C-dots modified pencil graphite electrodes was successfully applied for separation and quantification of D-/L-ascorbic acid in aqueous and some biological samples. Parameters, important to control the performance of the electrochemical sensor were investigated and optimized, including the effects of pH, monomer- template ratios, electropolymerization cycles and scan rates. The molecularly imprinted film exhibited a high chiral selectivity and sensitivity towards D-ascorbic acid and L-ascorbic acid respectively. The surface morphologies and electrochemical properties of the proposed sensor were characterized by scanning electron microscopy, cyclic voltammetry, difference pulse voltammetry, chrono-amperometry and electrochemical impedance spectroscopy. L-ascorbic acid selective sensor shows excellent selectivity towards the L-ascorbic acid in comparison to D- ascorbic acid vice versa for D- ascorbic acid selective sensor. Under optimal conditions the linear range of the calibration curve for L- ascorbic acid and D- ascorbic acid was 6.0–165.0 nM and 6.0–155.0 nM, with the detection limit of 0.001 nM and 0.002 nM. Chiral detection of L-ascorbic acid was successfully carried out in pharmaceuticals and human plasma samples (pregnant women and non pregnant women) via proposed sensor with good selectivity and sensitivity.

ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER

Energy Technology Data Exchange (ETDEWEB)

John R. Gallagher

2001-07-31

During the production of oil and gas, large amounts of water are brought to the surface and must be disposed of in an environmentally sensitive manner. This is an especially difficult problem in offshore production facilities where space is a major constraint. The chief regulatory criterion for produced water is oil and grease. Most facilities have little trouble meeting this criterion using conventional oil-water separation technologies. However, some operations have significant amounts of naphthenic acids in the water that behave as oil and grease but are not well removed by conventional technologies. Aerobic biological treatment of naphthenic acids in simulated-produced water has been demonstrated by others; however, the system was easily overloaded by the large amounts of low-molecular-weight organic acids often found in produced waters. The objective of this research was to determine the ability of an anaerobic biological system to treat these organic acids in a simulated produced water and to examine the potential for biodegradation of the naphthenic acids in the anaerobic environment. A small fixed-film anaerobic biological reactor was constructed and adapted to treat a simulated produced water. The bioreactor was tubular, with a low-density porous glass packing material. The inocula to the reactor was sediment from a produced-water holding pond from a municipal anaerobic digester and two salt-loving methanogenic bacteria. During start-up, the feed to the reactor contained glucose as well as typical produced-water components. When glucose was used, rapid gas production was observed. However, when glucose was eliminated and the major organic component was acetate, little gas was generated. Methane production from acetate may have been inhibited by the high salt concentrations, by sulfide, or because of the lack, despite seeding, of microbes capable of converting acetate to methane. Toluene, a minor component of the produced water (0.1 g/L) was removed in the

Hydrogen generation in SRAT with nitric acid and late washing flowsheets

International Nuclear Information System (INIS)

Hsu, C.W.

1992-01-01

Melter feed preparation processes, incorporating a final wash of the precipitate slurry feed to Defense Waste Processing Facility (DWPF) and a partial substitution of the SRAT formic acid requirement with nitric acid, should not produce peak hydrogen generation rates during Cold Chemical Runs (CCR's) and radioactive operation greater than their current, respective hydrogen design bases of 0.024 lb/hr and 1.5 lb/hr. A single SRAT bench-scale process simulation for CCR-s produced a DWPF equivalent peak hydrogen generation rate of 0.004 lb/hr. During radioactive operation, the peak hydrogen generation rate will be dependent on the extent DWPF deviates from the nominal precipitate hydrolysis and melter feed preparation process operating parameters. Two actual radioactive sludges were treated according to the new flowsheets. The peak hydrogen evolution rates were equivalent to 0.038 and 0.20 lb/hr (DWPF scale) respectively. Compared to the formic acid -- HAN hydrolysis flowsheets, these peak rates were reduced by a factor of 2.5 and 3.4 for Tank 15 and Tank 11 sludges, respectively

Multi-channel phase-equivalent transformation and supersymmetry

OpenAIRE

Shirokov, A. M.; Sidorenko, V. N.

2000-01-01

Phase-equivalent transformation of local interaction is generalized to the multi-channel case. Generally, the transformation does not change the number of the bound states in the system and their energies. However, with a special choice of the parameters, the transformation removes one of the bound states and is equivalent to the multi-channel supersymmetry transformation recently suggested by Sparenberg and Baye. Using the transformation, it is also possible to add a bound state to the discr...