Anisotropic scattering rate in Fe-substituted Bi 2Sr 2Ca(Cu 1-xFex) 2O 8+δ

DOE PAGES

Naamneh, M.; Lubashevsky, Y.; Lahoud, E.; ...

2015-05-27

We measured the electronic structure of Fe substituted Bi2212 using Angle Resolved Photoemission Spectroscopy (ARPES). We find that the substitution does not change the momentum dependence of the superconducting gap but induces a very anisotropic enhancement of the scattering rate. A comparison of the effect of Fe substitution to that of Zn substitution suggests that the Fe reduces T c so effectively because it supresses very strongly the coherence weight around the anti-nodes.

Synthesis and evaluation of 2-chloroethylnitrosoureas of substituted naphthalimides as mixed-function anticancer compounds.

PubMed

Samanta, S; Pain, A; Dutta, S; Sanyal, U

2001-01-01

New mixed function anticancer compounds as 2-chloroethylnitrosoureas of substituted naphthalimides represented by bromonap-NU 4a and chloronap-NU 4b, have been synthesized from 4-bromo- and 4-chloro-l,8-naphthalic anhydride, respectively following a 3-step process. Their chemical alkylating activity compared with nor -HN2 indicated that they possess greater alkylating activity than the latter. Their antitumour efficacies were assessed in vivo in two murine ascites tumours, namely Ehrlich ascites carcinoma (EAC) and Sarcoma-180 (S-180) by measuring the increase in median survival times (MST) of drug treated (T) over untreated control (C) mice. Two standard clinical drugs namely endoxan (cyclophosphamide) and 5-fluorouracil (5-FU) were used as positive controls for comparison. Both of them have displayed substantial and reproducible antitumoral activity in these tumours comparable with 5-FU. These were further screened in vitro in 6 different human tumour cell lines but no significant activity was observed in those lines.

A unique amino acid substitution, T126I, in human genotype C of hepatitis B virus S gene and its possible influence on antigenic structural change.

PubMed

Ren, Fengrong; Tsubota, Asahito; Hirokawa, Takatsugu; Kumada, Hiromitsu; Yang, Ziheng; Tanaka, Hiroshi

2006-11-15

Amino acid substitutions in the S gene of hepatitis B virus (HBV), especially in the 'a' determinant region, have been suggested to affect the antigenicity of the virus and the clinical outcome of the infected patient. However, no convincing evidence has been presented for this hypothesis, partly because the 3D structure of the S protein has not been determined. Comparative analysis of viral genes offers an approach to testing this hypothesis, as it may reveal signals of natural selection and provide insights into the functional significance of the observed amino acid substitutions. In this study, we analyze HBV S gene sequences obtained from 24 patients infected with HBV genotypes B or C, together with 16 representative viral strains of HBV genotypes A-F retrieved from GenBank. We use phylogenetic methods to infer evolutionary changes among HBV genotypes and to identify amino acid residues potentially under positive selective pressure. Furthermore, we employ the fragment assembly method to predict structural changes in the S protein. The results showed that an amino acid substitution within the 'a' determinant, T126I, was unique to genotype C, may affect the antigenicity of the HBsAg, and may result in poorer clinical outcomes of patients infected with genotype C viral strains. We suggest that an integrated approach of evolutionary comparison and structural prediction is useful in generating hypotheses for further laboratory validation.

Discriminative stimulus effects of inhaled1,1,1-trichloroethane in mice: comparison to other hydrocarbon vapors and volatile anesthetics

PubMed Central

Shelton, Keith L.

2009-01-01

Rationale Because the toxicity of many inhalants precludes evaluation in humans, drug discrimination, an animal model of subjective effects, can be used to gain insights on their poorly understood abuse-related effects. Objectives The purpose of the present study was to train a prototypic inhalant that has known abuse liability, 1,1,1-trichloroethane (TCE), as a discriminative stimulus in mice and compare it to other classes of inhalants. Methods Eight B6SJLF1/J mice were trained to discriminate 10 min of exposure to 12000 ppm inhaled TCE vapor from air and seven mice were trained to discriminate 4000 ppm TCE from air. Tests were then conducted to characterize the discriminative stimulus of TCE and to compare it to representative aromatic and chlorinated hydrocarbon vapors, volatile halogenated anesthetics as well as an odorant compound. Results Only the 12000 ppm TCE versus air discrimination group exhibited sufficient discrimination accuracy for substitution testing. TCE vapor concentration- and exposure time-dependently substituted for the 12000 ppm TCE vapor training stimulus. Full substitution was produced by trichloroethylene, toluene, enflurane and sevoflurane. Varying degrees of partial substitution were produced by the other volatile test compounds. The odorant, 2-butanol, did not produce any substitution for TCE. Conclusions The discriminative stimulus effects of TCE are shared fully or partially by chlorinated and aromatic hydrocarbons as well as by halogenated volatile anesthetics. However, these compounds can be differentiated from TCE both quantitatively and qualitatively. It appears that the degree of similarity is not solely a function of chemical classification but may also be dependent upon the neurochemical effects of the individual compounds. PMID:18972104

Analysis of potential errors in real-time streamflow data and methods of data verification by digital computer

USGS Publications Warehouse

Lystrom, David J.

1972-01-01

Various methods of verifying real-time streamflow data are outlined in part II. Relatively large errors (those greater than 20-30 percent) can be detected readily by use of well-designed verification programs for a digital computer, and smaller errors can be detected only by discharge measurements and field observations. The capability to substitute a simulated discharge value for missing or erroneous data is incorporated in some of the verification routines described. The routines represent concepts ranging from basic statistical comparisons to complex watershed modeling and provide a selection from which real-time data users can choose a suitable level of verification.

Solid recovered fuels in the steel industry.

PubMed

Kepplinger, Werner L; Tappeiner, Tamara

2012-04-01

By using waste materials as alternative fuels in metallurgical plants it is possible to minimize the traditionally used reducing agents, such as coke, coal, oil or natural gas. Moreover, by using waste materials in the metallurgical industry it is feasible to recover these materials as far as possible. This also represents another step towards environmental protection because carbon dioxide emissions can be reduced, if the H(2) content of the waste material is greater in comparison with that of the substituted fuel and the effects of global warming can therefore be reduced. In the present article various solid recovered fuels and their applications in the metallurgical industry are detailed.

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

Amino acid substitutions in random mutagenesis libraries: lessons from analyzing 3000 mutations.

PubMed

Zhao, Jing; Frauenkron-Machedjou, Victorine Josiane; Kardashliev, Tsvetan; Ruff, Anna Joëlle; Zhu, Leilei; Bocola, Marco; Schwaneberg, Ulrich

2017-04-01

The quality of amino acid substitution patterns in random mutagenesis libraries is decisive for the success in directed evolution campaigns. In this manuscript, we provide a detailed analysis of the amino acid substitutions by analyzing 3000 mutations of three random mutagenesis libraries (1000 mutations each; epPCR with a low-mutation and a high-mutation frequency and SeSaM-Tv P/P) employing lipase A from Bacillus subtilis (bsla). A comparison of the obtained numbers of beneficial variants in the mentioned three random mutagenesis libraries with a site saturation mutagenesis (SSM) (covering the natural diversity at each amino acid position of BSLA) concludes the diversity analysis. Seventy-six percent of the SeSaM-Tv P/P-generated substitutions yield chemically different amino acid substitutions compared to 64% (epPCR-low) and 69% (epPCR-high). Unique substitutions from one amino acid to others are termed distinct amino acid substitutions. In the SeSaM-Tv P/P library, 35% of all theoretical distinct amino acid substitutions were found in the 1000 mutation library compared to 25% (epPCR-low) and 26% (epPCR-high). Thirty-six percent of distinct amino acid substitutions found in SeSaM-Tv P/P were unobtainable by epPCR-low. Comparison with the SSM library showed that epPCR-low covers 15%, epPCR-high 18%, and SeSaM-Tv P/P 21% of obtainable beneficial amino acid positions. In essence, this study provides first insights on the quality of epPCR and SeSaM-Tv P/P libraries in terms of amino acid substitutions, their chemical differences, and the number of obtainable beneficial amino acid positions.

Differing antidepressant maintenance methodologies.

PubMed

Safer, Daniel J

2017-10-01

The principle evidence that antidepressant medication (ADM) is an effective maintenance treatment for adults with major depressive disorder (MDD) is from placebo substitution trials. These trials enter responders from ADM efficacy trials into randomized, double-blind placebo-controlled (RDBPC) effectiveness trials to measure the rate of MDD relapse over time. However, other randomized maintenance trial methodologies merit consideration and comparison. A systematic review of ADM randomized maintenance trials included research reports from multiple databases. Relapse rate was the main effectiveness outcome assessed. Five ADM randomized maintenance methodologies for MDD responders are described and compared for outcome. These effectiveness trials include: placebo-substitution, ADM/placebo extension, ADM extension, ADM vs. psychotherapy, and treatment as usual. The placebo-substitution trials for those abruptly switched to placebo resulted in unusually high (46%) rates of relapse over 6-12months, twice the continuing ADM rate. These trials were characterized by selective screening, high attrition, an anxious anticipation of a switch to placebo, and a risk of drug withdrawal symptoms. Selectively screened ADM efficacy responders who entered into 4-12month extension trials experienced relapse rates averaging ~10% with a low attrition rate. Non-industry sponsored randomized trials of adults with multiple prior MDD episodes who were treated with ADM maintenance for 1-2years experienced relapse rates averaging 40%. Placebo substitution trial methodology represents only one approach to assess ADM maintenance. Antidepressant maintenance research for adults with MDD should be evaluated for industry sponsorship, attrition, the impact of the switch to placebo, and major relapse differences in MDD subpopulations. Copyright © 2017. Published by Elsevier Inc.

Three Short Stories about Hexaarylbenzene-Porphyrin Scaffolds.

PubMed

Lungerich, Dominik; Hitzenberger, Jakob F; Donaubauer, Wolfgang; Drewello, Thomas; Jux, Norbert

2016-11-14

A feasible two-step synthesis and characterization of a full series of hexaarylbenzene (HAB) substituted porphyrins and tetrabenzoporphyrins is presented. Key steps represent the microwave-assisted porphyrin condensation and the statistical Diels-Alder reaction to the desired HAB-porphyrins. Regarding their applications, they proved to be easily accessible and effective high molecular mass calibrants for (MA)LDI mass spectrometry. The free-base and zinc(II) porphyrin systems, as well as the respective tetrabenzoporphyrins, demonstrate in solid state experiments strong red- and near-infrared-light emission and are potentially interesting for the application in "truly organic" light-emitting devices. Lastly, they represent facile precursors to large polycyclic aromatic hydrocarbon (PAH) substituted porphyrins. We prepared the first tetra-hexa-peri-hexabenzocoronene substituted porphyrin, which represents the largest prepared PAH-porphyrin conjugate to date. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mathematical Modeling Of Life-Support Systems

NASA Technical Reports Server (NTRS)

Seshan, Panchalam K.; Ganapathi, Balasubramanian; Jan, Darrell L.; Ferrall, Joseph F.; Rohatgi, Naresh K.

1994-01-01

Generic hierarchical model of life-support system developed to facilitate comparisons of options in design of system. Model represents combinations of interdependent subsystems supporting microbes, plants, fish, and land animals (including humans). Generic model enables rapid configuration of variety of specific life support component models for tradeoff studies culminating in single system design. Enables rapid evaluation of effects of substituting alternate technologies and even entire groups of technologies and subsystems. Used to synthesize and analyze life-support systems ranging from relatively simple, nonregenerative units like aquariums to complex closed-loop systems aboard submarines or spacecraft. Model, called Generic Modular Flow Schematic (GMFS), coded in such chemical-process-simulation languages as Aspen Plus and expressed as three-dimensional spreadsheet.

Novel Fischer-Tropsch catalysts

DOEpatents

Vollhardt, Kurt P. C.; Perkins, Patrick

1981-01-01

Novel polymer-supported metal complexes of the formula PS -R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS -H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS -Br; treating said PS -Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS -Li; substituting said PS - Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

Novel Fischer-Tropsch catalysts

DOEpatents

Vollhardt, Kurt P. C.; Perkins, Patrick

1980-01-01

Novel polymer-supported metal complexes of the formula: PS --R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS --H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS --Br; treating said PS --Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS --Li; substituting said PS-- Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

Novel Fischer-Tropsch catalysts

DOEpatents

Vollhardt, Kurt P. C.; Perkins, Patrick

1981-01-01

Novel polymer-supported metal complexes of the formula: PS --R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS --H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS --Br; treating said PS --Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS --Li; substituting said PS-- Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

Evaluation of cultured human dermal- and dermo-epidermal substitutes focusing on extracellular matrix components: Comparison of protein and RNA analysis.

PubMed

Oostendorp, Corien; Meyer, Sarah; Sobrio, Monia; van Arendonk, Joyce; Reichmann, Ernst; Daamen, Willeke F; van Kuppevelt, Toin H

2017-05-01

Treatment of full-thickness skin defects with split-thickness skin grafts is generally associated with contraction and scar formation and cellular skin substitutes have been developed to improve skin regeneration. The evaluation of cultured skin substitutes is generally based on qualitative parameters focusing on histology. In this study we focused on quantitative evaluation to provide a template for comparison of human bio-engineered skin substitutes between clinical and/or research centers, and to supplement histological data. We focused on extracellular matrix proteins since these components play an important role in skin regeneration. As a model we analyzed the human dermal substitute denovoDerm and the dermo-epidermal skin substitute denovoSkin. The quantification of the extracellular matrix proteins type III collagen and laminin 5 in tissue homogenates using western blotting analysis and ELISA was not successful. The same was true for assaying lysyl oxidase, an enzyme involved in crosslinking of matrix molecules. As an alternative, gene expression levels were measured using qPCR. Various RNA isolation procedures were probed. The gene expression profile for specific dermal and epidermal genes could be measured reliably and reproducibly. Differences caused by changes in the cell culture conditions could easily be detected. The number of cells in the skin substitutes was measured using the PicoGreen dsDNA assay, which was found highly quantitative and reproducible. The (dis) advantages of assays used for quantitative evaluation of skin substitutes are discussed. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Comparative Mitogenomic Analysis of Damsel Bugs Representing Three Tribes in the Family Nabidae (Insecta: Hemiptera)

PubMed Central

Song, Fan; Shi, Aimin; Zhou, Xuguo; Cai, Wanzhi

2012-01-01

Background Nabidae, a family of predatory heteropterans, includes two subfamilies and five tribes. We previously reported the complete mitogenome of Alloeorhynchus bakeri, a representative of the tribe Prostemmatini in the subfamily Prostemmatinae. To gain a better understanding of architecture and evolution of mitogenome in Nabidae, mitogenomes of five species representing two tribes (Gorpini and Nabini) in the subfamily Nabinae were sequenced, and a comparative mitogenomic analysis of three nabid tribes in two subfamilies was carried out. Methodology/Principal Findings Nabid mitogenomes share a similar nucleotide composition and base bias, except for the control region, where differences are observed at the subfamily level. In addition, the pattern of codon usage is influenced by the GC content and consistent with the standard invertebrate mitochondrial genetic code and the preference for A+T-rich codons. The comparison among orthologous protein-coding genes shows that different genes have been subject to different rates of molecular evolution correlated with the GC content. The stems and anticodon loops of tRNAs are extremely conserved, and the nucleotide substitutions are largely restricted to TψC and DHU loops and extra arms, with insertion-deletion polymorphisms. Comparative analysis shows similar rates of substitution between the two rRNAs. Long non-coding regions are observed in most Gorpini and Nabini mtDNAs in-between trnI-trnQ and/or trnS2-nad1. The lone exception, Nabis apicalis, however, has lost three tRNAs. Overall, phylogenetic analysis using mitogenomic data is consistent with phylogenies constructed mainly form morphological traits. Conclusions/Significance This comparative mitogenomic analysis sheds light on the architecture and evolution of mitogenomes in the family Nabidae. Nucleotide diversity and mitogenomic traits are phylogenetically informative at subfamily level. Furthermore, inclusion of a broader range of samples representing various taxonomic levels is critical for the understanding of mitogenomic evolution in damsel bugs. PMID:23029320

Rational Design of an Electron-Reservoir Pt(II) Complex for Efficient Photocatalytic Hydrogen Production from Water.

PubMed

Whang, Dong Ryeol; Park, Soo Young

2015-10-12

Herein we report a Pt(II) complex containing a 4,4'-bis[4-(triphenylsilyl)phenyl]-2,2'-bipyridine ligand as a molecular catalyst for water splitting. Systematic studies of the electrochemical and electronic properties of this catalyst, in comparison with two control complexes, reveal electron-reservoir characteristics upon two-electron reduction. A turnover number of 510,000 was recorded by employing this complex as a water reduction catalyst in combination with a state-of-the-art photosensitizer and N,N-dimethylaniline as a sacrificial electron donor, which represents a large improvement over the control complexes that do not contain the tetraphenylsilyl ligand substitution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Synthesis and biological activity of 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone analogs. 1. Substitution at the S atom].

PubMed

Schulze, W; Gutsche, W; Wohlrabe, K; Fleck, W; Tresselt, D

1985-08-01

The synthesis of S-substituted derivatives of 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone is described. The obtained 1,4-benzoquinone-guanylhydrazone-S-alkyl (resp. aralkyl)-isothiosemicarbazones, in comparison with the unsubstituted standard compound, showed a significantly decreased biological activity against the murine leukemias L 1210 and P 388 as well as against the growth of several kinds of bacteria. Therefore the S-substitution seems not to be useful for reaching a maximum activity.

Imidazoline phosphonic acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redmore, D.

1972-07-04

Nitrogen-heterocyclic phosphonic acids and derivatives are characterized by aminomethyl (or substituted methyl) phosphonic acids or derivatives thereof bonded directly or indirectly, i.e., through a N-side chain to the nitrogen atom in the heterocyclic ring, for example those containing in the molecule at least one of the following units: ..pi..Equation/sup -/ where represents a heterocyclic ring having a nitrogen atom on the ring; -R'N- represents an amino- terminated side chain attached directly to the ring nitrogen (which side chain may or may not be present); and ..pi..Equation/sup -/ represents a methyl (or substituted methyl) phosphonic acid group where M is hydrogen,more » an alcohol or a salt moiety, and X and Y are hydrogen or a substituted group such as alkyl, aryl, etc., of which one or 2 units may be present depending on the available nitrogen bonded by hydrogens, and to uses for these compounds, for example, as scale inhibitors, corrosion inhibitors, etc. (5 claims)« less

Violations of the International Code of Marketing of Breast-milk Substitutes: Indonesia context.

PubMed

Hidayana, Irma; Februhartanty, Judhiastuty; Parady, Vida A

2017-01-01

To measure compliance with the International Code of Marketing of Breast-milk Substitutes ('the Code') in Indonesia. The study was a cross-sectional survey using the Interagency Group on Breastfeeding Monitoring protocol. Public and private health facilities in six provinces on Java island in Indonesia. A total of 874 women (382 pregnant women and 492 breast-feeding mothers of infants below 6 months) and seventy-seven health workers were recruited from eighteen participating health facilities. The study also analysed a total of forty-four labels of breast-milk substitute products, twenty-seven television commercials for growing-up milk (for children >12 months) of nine brands and thirty-four print advertisements of fourteen brands. The study found that 20 % of the women had received advice and information on the use of breast-milk substitutes and 72 % had seen promotional materials for breast-milk substitutes. About 15 % reported receiving free samples and 16 % received gifts. Nearly a quarter of the health workers confirmed receiving visits from representatives of breast-milk substitute companies. Two health workers reported having received gifts from the companies. The most common labelling violations found were statements or visuals that discouraged breast-feeding and the absence of mention about the consideration of local climate in the expiration date. Violations of the Code by health workers, breast-milk substitute companies and their representatives were found in all provinces studied. A regular monitoring system should be in place to ensure improved compliance with and enforcement of the Code.

Polybenzimidazole compounds, polymeric media, and methods of post-polymerization modifications

DOEpatents

Klaehn, John R [Idaho Falls, ID; Peterson, Eric S [Idaho Falls, ID; Wertsching, Alan K [Idaho Falls, ID; Orme, Christopher J [Shelley, ID; Luther, Thomas A [Idaho Falls, ID; Jones, Michael G [Pocatello, ID

2007-08-21

A PBI compound includes imidazole nitrogens at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2-- where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least 5 equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about 15.

A Group Action Method for Construction of Strong Substitution Box

NASA Astrophysics Data System (ADS)

Jamal, Sajjad Shaukat; Shah, Tariq; Attaullah, Atta

2017-06-01

In this paper, the method to develop cryptographically strong substitution box is presented which can be used in multimedia security and data hiding techniques. The algorithm of construction depends on the action of a projective general linear group over the set of units of the finite commutative ring. The strength of substitution box and ability to create confusion is assessed with different available analyses. Moreover, the ability of resistance against malicious attacks is also evaluated. The substitution box is examined by bit independent criterion, strict avalanche criterion, nonlinearity test, linear approximation probability test and differential approximation probability test. This substitution box is equated with well-recognized substitution boxes such as AES, Gray, APA, S8, prime of residue, Xyi and Skipjack. The comparison shows encouraging results about the strength of the proposed box. The majority logic criterion is also calculated to analyze the strength and its practical implementation.

Polybenzimidazole compounds

DOEpatents

Klaehn, John R.; Peterson, Eric S.; Wertsching, Alan K.; Orme, Christopher J.; Luther, Thomas A.; Jones, Michael G.

2010-08-10

A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

Comparisons of pollen substitute diets for honey bees: consumption rates by colonies and effects on brood and adult populations.

USDA-ARS?s Scientific Manuscript database

Commercially available pollen substitute diets for honey bees (Apis mellifera L.) were evaluated for consumption and colony growth (brood and adult populations) and compared with pollen cake and high fructose corn syrup (HFCS). Two trials were conducted; the first for 3 months during the fall and w...

No variation and low synonymous substitution rates in coral mtDNA despite high nuclear variation

PubMed Central

Hellberg, Michael E

2006-01-01

Background The mitochondrial DNA (mtDNA) of most animals evolves more rapidly than nuclear DNA, and often shows higher levels of intraspecific polymorphism and population subdivision. The mtDNA of anthozoans (corals, sea fans, and their kin), by contrast, appears to evolve slowly. Slow mtDNA evolution has been reported for several anthozoans, however this slow pace has been difficult to put in phylogenetic context without parallel surveys of nuclear variation or calibrated rates of synonymous substitution that could permit quantitative rate comparisons across taxa. Here, I survey variation in the coding region of a mitochondrial gene from a coral species (Balanophyllia elegans) known to possess high levels of nuclear gene variation, and estimate synonymous rates of mtDNA substitution by comparison to another coral (Tubastrea coccinea). Results The mtDNA surveyed (630 bp of cytochrome oxidase subunit I) was invariant among individuals sampled from 18 populations spanning 3000 km of the range of B. elegans, despite high levels of variation and population subdivision for allozymes over these same populations. The synonymous substitution rate between B. elegans and T. coccinea (0.05%/site/106 years) is similar to that in most plants, but 50–100 times lower than rates typical for most animals. In addition, while substitutions to mtDNA in most animals exhibit a strong bias toward transitions, mtDNA from these corals does not. Conclusion Slow rates of mitochondrial nucleotide substitution result in low levels of intraspecific mtDNA variation in corals, even when nuclear loci vary. Slow mtDNA evolution appears to be the basal condition among eukaryotes. mtDNA substitution rates switch from slow to fast abruptly and unidirectionally. This switch may stem from the loss of just one or a few mitochondrion-specific DNA repair or replication genes. PMID:16542456

[Glycosilated derivatives of substituted hydroxylamine. II. Phase transfer synthesis and investigation of glycosyl transfer reaction of glucosaminides of substituted hydroxylavine].

PubMed

Kur'ianov, V O; Lushchik, A A; Chupakhina, T A

2013-01-01

1-(2-Acetamido-3,4,6,-tri-O-acetyl-2-deoxy-beta-D-glucopyranosyloxy)-benzotriazole reacted in boiling dichloromethane, in the presence of Luis acids as a promotors with primary and secondary aliphatic and cycloaliphatic alcohols and diisopropilidene galactose with alkyl-O-1,2-trans-glucosaminides formation. It was shown that the other glucosaminides of substituted hydroxylamine are not participated in this reaction. Structures of glucosaminides were identify by 1H-NMR-spectroscopy and comparison with known compounds.

Substitution of California Verbal Learning Test, second edition for Verbal Paired Associates on the Wechsler Memory Scale, fourth edition.

PubMed

Miller, Justin B; Axelrod, Bradley N; Rapport, Lisa J; Hanks, Robin A; Bashem, Jesse R; Schutte, Christian

2012-01-01

Two common measures used to evaluate verbal learning and memory are the Verbal Paired Associates (VPA) subtest from the Wechsler Memory Scales (WMS) and the second edition of the California Verbal Learning Test (CVLT-II). For the fourth edition of the WMS, scores from the CVLT-II can be substituted for VPA; the present study sought to examine the validity of the substitution. For each substitution, paired-samples t tests were conducted between original VPA scaled scores and scaled scores obtained from the CVLT-II substitution to evaluate comparability. Similar comparisons were made at the index score level. At the index score level, substitution resulted in significantly lower scores for the AMI (p = .03; r = .13) but not for the IMI (p = .29) or DMI (p = .09). For the subtest scores, substituted scaled scores for VPA were not significantly different from original scores for the immediate recall condition (p = .20) but were significantly lower at delayed recall (p = .01). These findings offer partial support for the substitution. For both the immediate and delayed conditions, the substitution produced generally lower subtest scores compared to original VPA subtest scores.

Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

PubMed

Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

2016-05-01

Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies. © IMechE 2016.

The Substitution Augmentation Modification Redefinition (SAMR) Model: A Critical Review and Suggestions for Its Use

ERIC Educational Resources Information Center

Hamilton, Erica R.; Rosenberg, Joshua M.; Akcaoglu, Mete

2016-01-01

The Substitution, Augmentation, Modification, and Redefinition (SAMR) model is a four-level, taxonomy-based approach for selecting, using, and evaluating technology in K-12 settings (Puentedura 2006). Despite its increasing popularity among practitioners, the SAMR model is not currently represented in the extant literature. To focus the ongoing…

SubJournal for Personnel Responsible for Substitute Teaching. Volume 5, Number 1, Summer 2004

ERIC Educational Resources Information Center

Smith, Geoffrey G., Ed.; Tippetts, Zach, Ed.

2004-01-01

This issue of the "SubJournal" focuses on the experiences of substitute teachers as represented through individual experience and research. Included within are ten articles written by people from various fields of study and work ranging from students seeking degrees in education to a report from the House of Commons in the United…

The Cost-Benefit Balance of Statins in Hawai'i: A Moving Target.

PubMed

Lum, Corey J; Nakagawa, Kazuma; Shohet, Ralph V; Seto, Todd B; Taira, Deborah A

2017-04-01

Statins are lipid-lowering medications used for primary and secondary prevention of atherosclerotic disease and represent a substantial portion of drug costs in the United States. A better understanding of prescribing patterns and drug costs should lead to more rational utilization and help constrain health care expenditures in the United States. The 2013 Medicare Provider Utilization and Payment Data: Part D Prescriber Public Use File for the State of Hawai'i was analyzed. The number of prescriptions for statins, total annual cost, and daily cost were calculated by prescriber specialty and drug. Potential savings from substituting the highest-cost statin with lower-cost statins were calculated. Over 421,000 prescriptions for statins were provided to Medicare Part D beneficiaries in Hawai'i in 2013, which cost $17.6M. The three most commonly prescribed statins were simvastatin (33.4%), atorvastatin (33.4%), and lovastatin (13.9%). Although rosuvastatin comprised 5.4% of the total statin prescriptions, it represented 30.1% of the total cost of statins due to a higher daily cost ($5.53/day) compared to simvastatin ($0.25/day) and atorvastatin ($1.10/day). Cardiologists and general practitioners prescribed the highest percentage of rosuvastatin (8% each). Hypothetical substitution of rosuvastatin would have resulted in substantial annual cost savings (Simvastatin would have saved $1.3M for 25% substitution and $5.1M for 100% substitution, while atorvastatin would have saved $1.1M for 25% substitution and $4.3M for 100% substitution). Among Medicare Part D beneficiaries in Hawai'i, prescribing variation for statins between specialties were observed. Substitution of higher-cost with lower-cost statins may lead to substantial cost savings.

Society already achieves economic benefits from generic substitution but fails to do the same for therapeutic substitution.

PubMed

Gumbs, Pearl D; Verschuren, W M Monique; Souverein, Patrick C; Mantel-Teeuwisse, Aukje K; de Wit, G Ardine; de Boer, Anthonius; Klungel, Olaf H

2007-11-01

To assess the potential annual savings due to generic and therapeutic substitution of statin therapy for the general Dutch population, taking the patients medical history into account. We conducted a population-based costing study using the PHARMO Record Linkage System (RLS). PHARMO RLS contains drug dispensing records from a representative sample of pharmacies located in more than 50 regions in the Netherlands. We selected all statin users in the database since 2003. The cost-savings of generic substitution of statin therapy for all simvastatin and pravastatin users, and of therapeutic substitution of statin therapy for other statin users were calculated. Substituting current users and new users of statins were considered separately. Therapeutic substitution was based on the medical history of the individual patient. Patients were only substituted if there was an appropriate substitute available. The appropriateness of substitution was based on drug-drug interactions between statins and possible comedication and the availability of an equipotent alternative. Substituting (generic and therapeutic) statin therapy for all current users would lead to potential annual savings of approximately 87 million euros. Substituting (generic and therapeutic) all starters on statin therapy would lead to potential annual savings of around 51 million euros. In the case of generic substitution only, the potential annual savings for all current simvastatin and pravastatin users would be 2.4 million euros and for the new users about 1.8 million euros. From an economic point of view, society could gain a lot from substituting statin therapy, especially from therapeutic substitution.

Brain cholinesterase activity of apparently normal wild birds

USGS Publications Warehouse

Hill, E.F.

1988-01-01

Organophosphorus and carbamate pesticides are potent anticholinesterase substances that have killed large numbers of wild birds of various species. Cause of death is diagnosed by demonstration of depressed brain cholinesterase (ChE) activity in combination with chemical detection of anticholinesterase residue in the affected specimen. ChE depression is determined by comparison of the affected specimen to normal ChE activity for a sample of control specimens of the same species, but timely procurement of controls is not always possible. Therefore, a reference file of normal whole brain ChE activity is provided for 48 species of wild birds from North America representing 11 orders and 23 families for use as emergency substitutes in diagnosis of anticholinesterase poisoning. The ChE values, based on 83 sets of wild control specimens from across the United States, are reproducible provided the described procedures are duplicated. Overall, whole brain ChE activity varied nearly three-fold among the 48 species represented, but it was usually similar for closely related species. However, some species were statistically separable in most families and some species of the same genus differed as much as 50%.

Comparison and characterization of soybean and sunflower lecithins used for chocolate production by high-performance thin-layer chromatography with fluorescence detection and electrospray mass spectrometry.

PubMed

Krüger, Stephanie; Bürmann, Laura; Morlock, Gertrud E

2015-03-25

The scarce availability of nongenetically modified soybeans on the world market represents a growing problem for food manufacturers. Hence, in this study the effects of substituting soybean with sunflower lecithin were investigated with regard to chocolate production. The glycerophospholipid pattern of the different lecithin samples was investigated by high-performance thin-layer chromatography fluorescence detection (HPTLC-FLD) and by HPTLC-positive ion electrospray ionization mass spectrometry (ESI(+)-MS) via the TLC-MS Interface and by scanning HPTLC-matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOFMS). Especially, the contents of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were of interest due to the influencing effects of these two glycerophospholipids on the rheological parameters of chocolate production. The lecithin substitution led to only slight differences in the rheological parameters of milk and dark chocolate. Limits of detection (LODs) and limits of quantification (LOQs) of seven glycerophospholipids were studied for three detection modes. Mean LODs ranged from 8 to 40 mg/kg for HPTLC-FLD and, using a single-quadrupole MS, from 10 to 280 mg/kg for HPTLC-ESI(+)-MS as well as from 15 to 310 mg/kg for HPTLC-FLD-ESI(+)-MS recorded after derivatization with the primuline reagent.

Extending the cleavage rules for the hammerhead ribozyme: mutating adenosine15.1 to inosine15.1 changes the cleavage site specificity from N16.2U16.1H17 to N16.2C16.1H17.

PubMed Central

Ludwig, J; Blaschke, M; Sproat, B S

1998-01-01

In this paper, we show that an adenosine to inosine mutation at position 15.1 changes the substrate specificity of the hammerhead ribozyme from N16.2U16.1H17to N16.2C16.1H17(H represents A, C or U). This result extends the hammerhead cleavage triplet definition from N16.2U16.1H17to the more general N16.2Y16.1H17. Comparison of cleavage rates using I15.1ribozymes for NCH triplets and standard A15.1 ribozymes for NUH triplets under single turnover conditions shows similar or slightly enhanced levels of reactivity for the I15. 1-containing structures. The effect of I15.1 substitution was also tested in nuclease-resistant 2'- O -alkyl substituted derivatives (oligozymes), showing a similar level of activity for the NUH and NCH cleaving structures. The availability of NCH triplets that can be targeted without loss of efficiency increases the flexibility of ribozyme targeting strategies. This was demonstrated by an efficient cleavage of an HCV transcript at a previously inaccessible GCA site in codon 2. PMID:9580675

Evolutionary rates of mitochondrial genomes correspond to diversification rates and to contemporary species richness in birds and reptiles

PubMed Central

Eo, Soo Hyung; DeWoody, J. Andrew

2010-01-01

Rates of biological diversification should ultimately correspond to rates of genome evolution. Recent studies have compared diversification rates with phylogenetic branch lengths, but incomplete phylogenies hamper such analyses for many taxa. Herein, we use pairwise comparisons of confamilial sauropsid (bird and reptile) mitochondrial DNA (mtDNA) genome sequences to estimate substitution rates. These molecular evolutionary rates are considered in light of the age and species richness of each taxonomic family, using a random-walk speciation–extinction process to estimate rates of diversification. We find the molecular clock ticks at disparate rates in different families and at different genes. For example, evolutionary rates are relatively fast in snakes and lizards, intermediate in crocodilians and slow in turtles and birds. There was also rate variation across genes, where non-synonymous substitution rates were fastest at ATP8 and slowest at CO3. Family-by-gene interactions were significant, indicating that local clocks vary substantially among sauropsids. Most importantly, we find evidence that mitochondrial genome evolutionary rates are positively correlated with speciation rates and with contemporary species richness. Nuclear sequences are poorly represented among reptiles, but the correlation between rates of molecular evolution and species diversification also extends to 18 avian nuclear genes we tested. Thus, the nuclear data buttress our mtDNA findings. PMID:20610427

Overcoming complexities: Damage detection using dictionary learning framework

NASA Astrophysics Data System (ADS)

Alguri, K. Supreet; Melville, Joseph; Deemer, Chris; Harley, Joel B.

2018-04-01

For in situ damage detection, guided wave structural health monitoring systems have been widely researched due to their ability to evaluate large areas and their ability detect many types of damage. These systems often evaluate structural health by recording initial baseline measurements from a pristine (i.e., undamaged) test structure and then comparing later measurements with that baseline. Yet, it is not always feasible to have a pristine baseline. As an alternative, substituting the baseline with data from a surrogate (nearly identical and pristine) structure is a logical option. While effective in some circumstance, surrogate data is often still a poor substitute for pristine baseline measurements due to minor differences between the structures. To overcome this challenge, we present a dictionary learning framework to adapt surrogate baseline data to better represent an undamaged test structure. We compare the performance of our framework with two other surrogate-based damage detection strategies: (1) using raw surrogate data for comparison and (2) using sparse wavenumber analysis, a precursor to our framework for improving the surrogate data. We apply our framework to guided wave data from two 108 mm by 108 mm aluminum plates. With 20 measurements, we show that our dictionary learning framework achieves a 98% accuracy, raw surrogate data achieves a 92% accuracy, and sparse wavenumber analysis achieves a 57% accuracy.

Characteristics of students in comparative problem solving

NASA Astrophysics Data System (ADS)

Irfan, M.; Sudirman; Rahardi, R.

2018-01-01

Often teachers provided examples and exercised to students with regard to comparative problems consisting of one quantity. In this study, the researchers gave the problem of comparison with the two quantities mixed. It was necessary to have a good understanding to solve this problem. This study aimed to determine whether students understand the comparison in depth and be able to solve the problem of non-routine comparison. This study used qualitative explorative methods, with researchers conducting in-depth interviews on subjects to explore the thinking process when solving comparative problems. The subject of this study was three students selected by purposive sampling of 120 students. From this research, researchers found there were three subjects with different characteristics, namely: subject 1, he did the first and second questions with methods of elimination and substitution (non-comparison); subject 2, he did the first question with the concept of comparison although the answer was wrong, and did the second question with the method of elimination and substitution (non-comparison); and subject 3, he did both questions with the concept of comparison. In the first question, he did wrong because he was unable to understand the problem, while on the second he did correctly. From the characteristics of the answers, the researchers divided into 3 groups based on thinking process, namely: blind-proportion, partial-proportion, and proportion thinking.

Evolutionary history of the most speciose mammals: molecular phylogeny of muroid rodents.

PubMed

Michaux, J; Reyes, A; Catzeflis, F

2001-11-01

Phylogenetic relationships between 32 species of rodents representing 14 subfamilies of Muridae and four subfamilies of Dipodidae were studied using sequences of the nuclear protein-coding genes Lecithin Cholesterol Acyl Transferase (LCAT) and von Willebrand Factor (vWF). An examination of some evolutionary properties of each data matrix indicates that the two genes are rather complementary, with lower rates of nonsynonymous substitutions for LCAT. Both markers exhibit a wide range of GC3 percentages (55%-89%), with several taxa above 70% GC3 for vWF, which indicates that those exonic regions might belong to the richest class of isochores. The primary sequence data apparently harbor few saturations, except for transitions on third codon positions for vWF, as indicated by comparisons of observed and expected pairwise values of substitutions. Phylogenetic trees based on 1,962 nucleotidic sites from the two genes indicate that the 14 Muridae subfamilies are organized into five major lineages. An early isolation leads to the clade uniting the fossorial Spalacinae and semifossorial Rhizomyinae with a strong robustness. The second lineage includes a series of African taxa representing nesomyines, dendromurines, cricetomyines, and the sole living member of mystromyines. The third one comprises only the mouselike hamster CALOMYSCUS: The fourth clade represents the cricetines, myospalacines, sigmodontines, and arvicolines, whereas the fifth one comprises four "traditional" subfamilies (Gerbillinae, Murinae, Otomyinae, and Acomyinae). Within these groups, we confirm the monophyly of almost all studied subfamilies, namely, Spalacinae, Rhizomyinae, Nesomyinae, Cricetomyinae, Arvicolinae, Sigmodontinae, Cricetinae, Gerbillinae, Acomyinae, and Murinae. Finally, we present evidence that the sister group of Acomyinae is Gerbillinae, and we confirm a nested position of Myospalacinae within Cricetinae and Otomyinae within Murinae. From a biogeographical point of view, the five main lineages spread and radiated from Asia with different degrees of success: the first three groups are now represented by a limited number of species and genera localized in some regions, whereas the last two groups radiated in a large variety of species and genera dispersed all over the world.

Photovoltaic Small Molecules of TPA(FxBT-T-Cz)3: Tuning Open-Circuit Voltage over 1.0 V for Their Organic Solar Cells by Increasing Fluorine Substitution.

PubMed

Wang, Qiong; Duan, Linrui; Tao, Qiang; Peng, Wenhong; Chen, Jianhua; Tan, Hua; Yang, Renqiang; Zhu, Weiguo

2016-11-09

To simultaneously improve both open-circuit voltage (V oc ) and short-circuit current density (J sc ) for organic solar cells, a novel D(A-π-Ar) 3 type of photovoltaic small molecules of TPA(F x BT-T-3Cz) 3 was designed and synthesized, which contain central triphenylamine (TPA), terminal carbazole (Cz), armed fluorine-substituted benzothiadiazole (F x BT, where x = 1 or 2), and bridged thiophene (T) units. A narrowed ultraviolet-visible absorption and a decreasing highest occupied molecular orbital energy level were observed from TPA(F 1 BT-T-3Cz) 3 to TPA(F 2 BT-T-3Cz) 3 with increasing fluorine substitution. However, the TPA(F 2 BT-T-3Cz) 3 /PC 71 BM-based solar devices showed a rising V oc of 1.01 V and an enhanced J sc of 10.84 mA cm -2 as well as a comparable power conversion efficiency of 4.81% in comparison to the TPA(F 1 BT-T-3Cz) 3 /PC 71 BM-based devices. Furthermore, in comparison to the parent TPA(BT-T-3Cz) 3 molecule without fluorine substitution, the fluorine-substituted TPA(F x BT-T-3Cz) 3 molecules exhibited significantly incremental V oc and J sc values in their bulk heterojunction organic solar cells, owing to fluorine incorporation in the electron-deficient benzothiadiazole unit.

X-ray phase contrast imaging of the breast: Analysis of tissue simulating materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vedantham, Srinivasan; Karellas, Andrew

Purpose: Phase contrast imaging, particularly of the breast, is being actively investigated. The purpose of this work is to investigate the x-ray phase contrast properties of breast tissues and commonly used breast tissue substitutes or phantom materials with an aim of determining the phantom materials best representative of breast tissues. Methods: Elemental compositions of breast tissues including adipose, fibroglandular, and skin were used to determine the refractive index, n= 1 -{delta}+i {beta}. The real part of the refractive index, specifically the refractive index decrement ({delta}), over the energy range of 5-50 keV were determined using XOP software (version 2.3, Europeanmore » Synchrotron Radiation Facility, France). Calcium oxalate and calcium hydroxyapatite were considered to represent the material compositions of microcalcifications in vivo. Nineteen tissue substitutes were considered as possible candidates to represent adipose tissue, fibroglandular tissue and skin, and four phantom materials were considered as possible candidates to represent microcalcifications. For each material, either the molecular formula, if available, or the elemental composition based on weight fraction, was used to determine {delta}. At each x-ray photon energy, the absolute percent difference in {delta} between the breast tissue and the substitute material was determined, from which three candidates were selected. From these candidate tissue substitutes, the material that minimized the absolute percent difference in linear attenuation coefficient {mu}, and hence {beta}, was considered to be best representative of that breast tissue. Results: Over the energy range of 5-50 keV, while the {delta} of CB3 and fibroglandular tissue-equivalent material were within 1% of that of fibroglandular tissue, the {mu} of fibroglandular tissue-equivalent material better approximated the fibroglandular tissue. While the {delta} of BR10 and adipose tissue-equivalent material were within 1% of that of adipose tissue, the tissue-equivalent material better approximated the adipose tissue in terms of {mu}. Polymethyl methacrylate, a commonly used tissue substitute, exhibited {delta} greater than fibroglandular tissue by {approx}12%. The A-150 plastic closely approximated the skin. Several materials exhibited {delta} between that of adipose and fibroglandular tissue. However, there was an energy-dependent mismatch in terms of equivalent fibroglandular weight fraction between {delta} and {mu} for these materials. For microcalcifications, aluminum and calcium carbonate were observed to straddle the {delta} and {mu} of calcium oxalate and calcium hydroxyapatite. Aluminum oxide, commonly used to represent microcalcifications in the American College of Radiology recommended phantoms for accreditation exhibited {delta} greater than calcium hydroxyapatite by {approx}23%. Conclusions: A breast phantom comprising A-150 plastic to represent the skin, commercially available adipose and fibroglandular tissue-equivalent formulations to represent adipose and fibroglandular tissue, respectively, was found to be best suited for x-ray phase-sensitive imaging of the breast. Calcium carbonate or aluminum can be used to represent microcalcifications.« less

X-ray phase contrast imaging of the breast: Analysis of tissue simulating materials1

PubMed Central

Vedantham, Srinivasan; Karellas, Andrew

2013-01-01

Purpose: Phase contrast imaging, particularly of the breast, is being actively investigated. The purpose of this work is to investigate the x-ray phase contrast properties of breast tissues and commonly used breast tissue substitutes or phantom materials with an aim of determining the phantom materials best representative of breast tissues. Methods: Elemental compositions of breast tissues including adipose, fibroglandular, and skin were used to determine the refractive index, n = 1 − δ + i β. The real part of the refractive index, specifically the refractive index decrement (δ), over the energy range of 5–50 keV were determined using XOP software (version 2.3, European Synchrotron Radiation Facility, France). Calcium oxalate and calcium hydroxyapatite were considered to represent the material compositions of microcalcifications in vivo. Nineteen tissue substitutes were considered as possible candidates to represent adipose tissue, fibroglandular tissue and skin, and four phantom materials were considered as possible candidates to represent microcalcifications. For each material, either the molecular formula, if available, or the elemental composition based on weight fraction, was used to determine δ. At each x-ray photon energy, the absolute percent difference in δ between the breast tissue and the substitute material was determined, from which three candidates were selected. From these candidate tissue substitutes, the material that minimized the absolute percent difference in linear attenuation coefficient μ, and hence β, was considered to be best representative of that breast tissue. Results: Over the energy range of 5–50 keV, while the δ of CB3 and fibroglandular tissue-equivalent material were within 1% of that of fibroglandular tissue, the μ of fibroglandular tissue-equivalent material better approximated the fibroglandular tissue. While the δ of BR10 and adipose tissue-equivalent material were within 1% of that of adipose tissue, the tissue-equivalent material better approximated the adipose tissue in terms of μ. Polymethyl methacrylate, a commonly used tissue substitute, exhibited δ greater than fibroglandular tissue by ∼12%. The A-150 plastic closely approximated the skin. Several materials exhibited δ between that of adipose and fibroglandular tissue. However, there was an energy-dependent mismatch in terms of equivalent fibroglandular weight fraction between δ and μ for these materials. For microcalcifications, aluminum and calcium carbonate were observed to straddle the δ and μ of calcium oxalate and calcium hydroxyapatite. Aluminum oxide, commonly used to represent microcalcifications in the American College of Radiology recommended phantoms for accreditation exhibited δ greater than calcium hydroxyapatite by ∼23%. Conclusions: A breast phantom comprising A-150 plastic to represent the skin, commercially available adipose and fibroglandular tissue-equivalent formulations to represent adipose and fibroglandular tissue, respectively, was found to be best suited for x-ray phase-sensitive imaging of the breast. Calcium carbonate or aluminum can be used to represent microcalcifications. PMID:23556900

The Impact of Generic Substitution on Health and Economic Outcomes: A Systematic Review.

PubMed

Gothe, H; Schall, I; Saverno, K; Mitrovic, M; Luzak, A; Brixner, D; Siebert, U

2015-08-01

Generic drugs are considered therapeutically equivalent to their original counterparts and lower in acquisition costs. However, the overall impact of generic substitution (GS) on global clinical and economic outcomes has not been conclusively evaluated. To test whether (1) generics and original products yield the same health outcomes, and (2) generic therapies save economic resources versus original therapies. We performed a systematic literature review in Medline, Embase, and the Cochrane Database of Systematic Reviews to identify original studies that examine clinical or economic outcomes of GS. After standardized data extraction, reported outcomes were categorized as supporting or rejecting the hypotheses. Each reported outcome was assessed and accounted for supporting and opposing GS. One publication could provide multiple outcome comparisons. We included 40 studies across ten therapeutic areas. Fourteen studies examined patients on de novo therapy; 24 studies investigated maintenance drug therapy, and two studies considered both settings. Overall, 119 outcome comparisons were examined. Of 97 clinical outcome comparisons, 67% reported no significant difference between generic drugs and their off-patent counterparts. Of 22 economic comparisons, 64% suggested that GS increased costs. Consequently, hypothesis (1) was supported but hypothesis (2) was not. We found no major differences among studies that investigated clinical outcomes with de novo or maintenance therapy. The review suggests that clinical effects are similar after GS. However, economic savings are not guaranteed. More systematic research comparing clinical and economic outcomes with or without GS is needed to inform policy on the use of generic substitution.

Phylogeny and evolution of the auks (subfamily Alcinae) based on mitochondrial DNA sequences

USGS Publications Warehouse

Moum, Truls; Johansen, Steinar; Erikstad, Kjell Einar; Piatt, John F.

1994-01-01

The genetic divergence and phylogeny of the auks was assessed by mitochondrial DNA sequence comparisons in a study using 19 of the 22 auk species and two outgroup representatives. We compared more than 500 nucleotides from each of two mitochondrial genes encoding 12S rRNA and the NADH dehydrogenase subunit 6. Divergence times were estimated from transversional substitutions. The dovekie (Alle alle) is related to the razorbill (Alca torda) and the murres (Uria spp). Furthermore, the Xantus's murrelet (Synthliboramphus hypoleucus) and the ancient (Synthliboramphus antiquus) and Japanese murrelets (Synthliboramphus wumizusume) are genetically distinct members of the same main lineage, whereas brachyramphine and synthliboramphine murrelets are not closely related. An early adaptive radiation of six main species groups of auks seems to trace back to Middle Miocene. Later speciation probably involved ecological differentiations and geographical isolations.

Assessing the Substitutability of Surrogate Measures of Job Performance of Hands-On Work Sample Tests

DTIC Science & Technology

1992-06-01

surrogate of .90 be a criterion for initially identifying substitutability. Gottfredson (1986) provides additional guidance for making comparison among... intelligence and reading level, for example, may yield a greater understanding of the general conditions that facilitate development and applicability of...noted by Gottfredson (1986), different measures may be required for different classes of jobs due to systematic differences in job demands, and these

Experimental Validation of the Efficiency of Gamalant-paste-FORTE Plus, a Russian Osteoinductive Material, in Oral Surgery.

PubMed

Olesova, V N; Amkhadova, M A; Simakova, T G; Mirgazizov, M Z; Pozharitskaya, M M

2017-03-01

For evaluation of the efficiency of bone substitute, nanostructurized Gamalant-paste-FORTEPlus was placed into a mandibular defect in rats. Bone tissue reparation was evaluated after 30 days by histological methods under a microscope. Use of bone substitute in experimental mandibular defect ensured more complete and rapid restructuring of the bone tissue in comparison with the control (natural healing).

Cold-adapted tubulins in the glacier ice worm, Mesenchytraeus solifugus.

PubMed

Tartaglia, Lawrence J; Shain, Daniel H

2008-11-01

Glacier ice worms, Mesenchytraeus solifugus and related species, are the only known annelids that survive obligately in glacier ice and snow. One fundamental component of cold temperature adaptation is the ability to polymerize tubulin, which typically depolymerizes at low physiological temperatures (e.g., <10 degrees C) in most temperate species. In this study, we isolated two alpha-tubulin (Msalpha1, Msalpha2) and two beta-tubulin (Msbeta1, Msbeta2) subunits from an ice worm cDNA library, and compared their predicted amino acid sequences with homologues from other cold-adapted organisms (e.g., Antarctic fish, ciliate) in an effort to identify species-specific amino acid substitutions that contribute to cold temperature-dependent tubulin polymerization. Our comparisons and predicted protein structures suggest that ice worm-specific amino acid substitutions stabilize lateral contact associations, particularly between beta-tubulin protofilaments, but these substitutions occur at different positions in comparison with other cold-adapted tubulins. The ice worm tubulin gene family appears relatively small, comprising one primary alpha- and one primary beta-tubulin monomers, though minor isoforms and pseudogenes were identified. Our analyses suggest that variation occurs in the strategies (i.e., species-specific amino acid substitutions, gene number) by which cold-adapted taxa have evolved the ability to polymerize tubulin at low physiological temperatures.

Clinical differences among nonsteroidal antiinflammatory drugs: implications for therapeutic substitution in ambulatory patients.

PubMed

Levy, R A; Smith, D L

1989-01-01

The practice of therapeutic substitution, i.e., replacing one drug with another chemically different drug from the same therapeutic class, represents an important therapeutic modification with potential clinical significance far beyond that of generic substitution. Adverse consequences following therapeutic substitution of nonsteroidal antiinflammatory drugs (NSAID) is of special concern because of substantial differences among these agents in pharmacokinetic, pharmacological, and clinical properties. Therapeutic substitution of NSAID for ambulatory patients may result in compromised clinical outcome because (1) patient response is unpredictable and selection of the optimal agent must be tailored for each patient; (2) substantial differences exist in adverse reaction profiles; (3) drug interaction studies are lacking; and (4) selection of an agent must be individualized to ensure compliance with the dosing regimen. Cost savings achieved through therapeutic substitution of NSAID may be lost by additional overall treatment costs due to adverse reactions or suboptimal therapy. The occurrence of adverse or suboptimal effects in ambulatory patients is more likely if NSAID are substituted without full knowledge of the patient's medical history and clinical status. Communication between the pharmacy and prescribing physician regarding a patient's specific needs is essential for rational substitution among NSAID.

Ecosystem Services in Conservation Planning: Targeted Benefits vs. Co-Benefits or Costs?

PubMed Central

Chan, Kai M. A.; Hoshizaki, Lara; Klinkenberg, Brian

2011-01-01

There is growing support for characterizing ecosystem services in order to link conservation and human well-being. However, few studies have explicitly included ecosystem services within systematic conservation planning, and those that have follow two fundamentally different approaches: ecosystem services as intrinsically-important targeted benefits vs. substitutable co-benefits. We present a first comparison of these two approaches in a case study in the Central Interior of British Columbia. We calculated and mapped economic values for carbon storage, timber production, and recreational angling using a geographical information system (GIS). These ‘marginal’ values represent the difference in service-provision between conservation and managed forestry as land uses. We compared two approaches to including ecosystem services in the site-selection software Marxan: as Targeted Benefits, and as Co-Benefits/Costs (in Marxan's cost function); we also compared these approaches with a Hybrid approach (carbon and angling as targeted benefits, timber as an opportunity cost). For this analysis, the Co-Benefit/Cost approach yielded a less costly reserve network than the Hybrid approach (1.6% cheaper). Including timber harvest as an opportunity cost in the cost function resulted in a reserve network that achieved targets equivalently, but at 15% lower total cost. We found counter-intuitive results for conservation: conservation-compatible services (carbon, angling) were positively correlated with each other and biodiversity, whereas the conservation-incompatible service (timber) was negatively correlated with all other networks. Our findings suggest that including ecosystem services within a conservation plan may be most cost-effective when they are represented as substitutable co-benefits/costs, rather than as targeted benefits. By explicitly valuing the costs and benefits associated with services, we may be able to achieve meaningful biodiversity conservation at lower cost and with greater co-benefits. PMID:21915318

Lack of pathogenic mutations in SOS1 gene in phenytoin-induced gingival overgrowth patients.

PubMed

Margiotti, Katia; Pascolini, Giulia; Consoli, Federica; Guida, Valentina; Di Bonaventura, Carlo; Giallonardo, Anna Teresa; Pizzuti, Antonio; De Luca, Alessandro

2017-08-01

Gingival overgrowth is a side effect associated with some distinct classes of drugs, such as anticonvulsants, immunosuppressants, and calcium channel blockers. One of the main drugs associated with gingival overgrowth is the antiepileptic phenytoin, which affects gingival tissues by altering extracellular matrix metabolism. It has been shown that mutation of human SOS1 gene is responsible for a rare hereditary gingival fibromatosis type 1, a benign gingival overgrowth. The aim of the present study is to evaluate the possible contribution of SOS1 mutation to gingival overgrowth-related phenotype. We selected and screened for mutations a group of 24 epileptic patients who experienced significant gingival overgrowth following phenytoin therapy. Mutation scanning was carried out by denaturing high-performance liquid chromatography analysis of the entire coding region of the SOS1 gene. Novel identified variants were analyzed in-silico by using Alamut Visual mutation interpretation software, and comparison with normal control group was done. Mutation scanning of the entire coding sequence of SOS1 gene identified seven intronic variants and one new exonic substitution (c.138G>A). The seven common intronic variants were not considered to be of pathogenic importance. The exonic substitution c.138G>A was found to be absent in 100 ethnically matched normal control chromosomes, but was not expected to have functional significance based on prediction bioinformatics tools. This study represents the first mutation analysis of the SOS1 gene in phenytoin-induced gingival overgrowth epileptic patients. Present results suggest that obvious pathogenic mutations in the SOS1 gene do not represent a common mechanism underlying phenytoin-induced gingival overgrowth in epileptic patients; other mechanisms are likely to be involved in the pathogenesis of this drug-induced phenotype. Copyright © 2017 Elsevier Ltd. All rights reserved.

New tools for non-invasive exploration of collagen network in cartilaginous tissue-engineered substitute.

PubMed

Henrionnet, Christel; Dumas, Dominique; Hupont, Sébastien; Stoltz, Jean François; Mainard, Didier; Gillet, Pierre; Pinzano, Astrid

2017-01-01

In tissue engineering approaches, the quality of substitutes is a key element to determine its ability to treat cartilage defects. However, in clinical practice, the evaluation of tissue-engineered cartilage substitute quality is not possible due to the invasiveness of the standard procedure, which is to date histology. The aim of this work was to validate a new innovative system performed from two-photon excitation laser adapted to an optical macroscope to evaluate at macroscopic scale the collagen network in cartilage tissue-engineered substitutes in confrontation with gold standard histologic techniques or immunohistochemistry to visualize type II collagen. This system permitted to differentiate the quality of collagen network between ITS and TGF-β1 treatments. Multiscale large field imaging combined to multimodality approaches (SHG-TCSPC) at macroscopical scale represent an innovative and non-invasive technique to monitor the quality of collagen network in cartilage tissue-engineered substitutes before in vivo implantation.

Analyzing Environmental Policies for Chlorinated Solvents with a Model of Markets and Regulations

DTIC Science & Technology

1991-01-01

electronics, aerospace, fabricated metal products, and dry cleaning depend heavily on chlorinated solvents in their production processes . For example...production processes . The second of the model’s components is a group of economic equations that represents all of the solvent substitutions in...Instead, the process for numerically specifying the substitution parameters involves eliciting expert judgments and then normalizing the parameters

Synthesis and biological evaluation of a series of tangeretin-derived chalcones.

PubMed

Quintin, Jérôme; Desrivot, Julie; Thoret, Sylviane; Le Menez, Patrick; Cresteil, Thierry; Lewin, Guy

2009-01-01

A series of chalcones polyoxygenated on the ring A (with pentamethoxy or 2'-hydroxy-3',4',5',6'-tetramethoxy substitution patterns) was synthesized from tangeretin, a natural Citrus flavonoid. These chalcones were evaluated for their antiproliferative, activation of apoptosis, inhibition of tubulin assembly and antileishmanial activities. Comparison with the reference analogous 3',4',5'-trimethoxylated chalcones showed that such peroxygenated substitution patterns on the ring A were less beneficial to these activities.

1H and 13C NMR spectra of C-6 and C-9 substituted 3-azabicyclco[3.3.1]nonanes.

PubMed

Goodall, Kirsten; Brimble, Margaret; Barker, David

2008-01-01

The 1H and 13C NMR data for 3-azabicyclo[3.3.1]nonanes with OH and OMe substituents at C-6 and C-9 were measured using 1D (DEPT) and 2D (COSY, HSQC, HMBC, NOESY) experiments. Comparison of this NMR data illustrates the effects of stereochemistry and substitution at these positions. Copyright (c) 2007 John Wiley & Sons, Ltd.

Slow but not low: genomic comparisons reveal slower evolutionary rate and higher dN/dS in conifers compared to angiosperms.

PubMed

Buschiazzo, Emmanuel; Ritland, Carol; Bohlmann, Jörg; Ritland, Kermit

2012-01-20

Comparative genomics can inform us about the processes of mutation and selection across diverse taxa. Among seed plants, gymnosperms have been lacking in genomic comparisons. Recent EST and full-length cDNA collections for two conifers, Sitka spruce (Picea sitchensis) and loblolly pine (Pinus taeda), together with full genome sequences for two angiosperms, Arabidopsis thaliana and poplar (Populus trichocarpa), offer an opportunity to infer the evolutionary processes underlying thousands of orthologous protein-coding genes in gymnosperms compared with an angiosperm orthologue set. Based upon pairwise comparisons of 3,723 spruce and pine orthologues, we found an average synonymous genetic distance (dS) of 0.191, and an average dN/dS ratio of 0.314. Using a fossil-established divergence time of 140 million years between spruce and pine, we extrapolated a nucleotide substitution rate of 0.68 × 10(-9) synonymous substitutions per site per year. When compared to angiosperms, this indicates a dramatically slower rate of nucleotide substitution rates in conifers: on average 15-fold. Coincidentally, we found a three-fold higher dN/dS for the spruce-pine lineage compared to the poplar-Arabidopsis lineage. This joint occurrence of a slower evolutionary rate in conifers with higher dN/dS, and possibly positive selection, showcases the uniqueness of conifer genome evolution. Our results are in line with documented reduced nucleotide diversity, conservative genome evolution and low rates of diversification in conifers on the one hand and numerous examples of local adaptation in conifers on the other hand. We propose that reduced levels of nucleotide mutation in large and long-lived conifer trees, coupled with large effective population size, were the main factors leading to slow substitution rates but retention of beneficial mutations.

Use of black soldier fly larvae (Hermetia illucens) to substitute soybean meal in ruminant diet: An in vitro rumen fermentation study

PubMed Central

Jayanegara, Anuraga; Novandri, Briliannanda; Yantina, Nover; Ridla, Muhammad

2017-01-01

Aim: This experiment aimed to evaluate substitution of soybean meal (SBM) by black soldier fly (BSF) larvae meal in a napier grass diet as performed by an in vitro rumen fermentation system. Materials and Methods: Samples of napier grass, SBM, and BSF larvae age 1 week (BSF1) and 2 weeks (BSF2) were arranged according to the following dietary treatments (dry matter [DM] basis): T1, 100% napier grass; T2, 60% napier grass + 40% SBM; T3, 60% napier grass + 40% BSF1; T4, 60% napier grass + 40% BSF2; T5, 60% napier grass + 20% SBM + 20% BSF1; and T6, 60% napier grass + 20% SBM + 20% BSF2. The samples were determined for their chemical composition and were incubated in vitro using buffered rumen fluid for 48 h at 39°C. In vitro incubation was carried out in three runs and represented by two incubation bottles per run. Results: Supplementation of BSF, both BSF1 and BSF2, increased ether extract, neutral- and acid-detergent insoluble crude protein contents of T3-T6 diets. The T3 or T4 diet resulted in lower ruminal ammonia concentration, in vitro DM digestibility, and in vitro organic matter (OM) digestibility as compared to those in T2 (p<0.05). Diet supplemented with BSF produced lower methane emission in comparison to that of supplemented with SBM (p<0.05). Diet containing BSF2 produced lower methane and methane per digestible OM than that containing BSF1 (p<0.05). Conclusion: Substitution of SBM by BSF in ruminant diet results in a lower nutritional value in vitro but with an advantage of lowering ruminal methane emission. PMID:29391684

Substituting energy crops with organic wastes and agro-industrial residues for biogas production.

PubMed

Schievano, Andrea; D'Imporzano, Giuliana; Adani, Fabrizio

2009-06-01

In this study, industrial and agro-industrial by-products and residues (BRs), animal manures (AMs), and various types of organic wastes (OWs) were analyzed to evaluate their suitability as substitutes for energy crops (ECs) in biogas production. A comparison between the costs of the volume of biogas that can be produced from each substrate was presented with respect to the prices of the substrates in the Italian market. Furthermore, four different feeding mixtures were compared with a mixture of EC and swine manure (Mixture A) used in a full-scale plant in Italy. Swine manure is always included as a basic substrate in the feeding mixtures, because many of the Italian biogas plants are connected to farms. When EC were partially substituted with BR (Mixture B), the cost (0.28 euro Nm(-3)) of the volume of biogas of Mixture A dropped to 0.18 euro Nm(-3). Furthermore, when the organic fraction of municipal solid waste (OFMSW) and olive oil sludge (OS) were used as possible solutions (Mixtures C and D), the costs of the volume of biogas were -0.20 and 0.11euroNm(-3), respectively. The negative price signifies that operators earn money for treating the waste. For the fifth mix (Mixture E) of the OFMSW with a high solid substrate, such as glycerin from biodiesel production, the resulting cost of the volume of biogas produced was -0.09 euro Nm(-3). By comparing these figures, it is evident that the biogas plants at farm level are good candidates for treating organic residues of both municipalities and the agro-industrial sector in a cost-effective way, and in providing territorially diffused electric and thermal power. This may represent a potential development for agrarian economy.

Quantum-chemical modeling of smectite clays

NASA Technical Reports Server (NTRS)

Aronowitz, S.; Coyne, L.; Lawless, J.; Rishpon, J.

1982-01-01

A self-consistent charge extended Hueckel program is used in modeling isomorphic substitution of Al(3+) by Na(+), K(+), Mg(2+), Fe(2+), and Fe(3+) in the octahedral layer of a dioctahedral smectite clay, such as montmorillonite. Upon comparison of the energies involved in the isomorphic substitution, it is found that the order for successful substitution is as follows: Al(3+), Fe(3+), Mg(2+), Fe(2+), Na(+), which is equivalent to Ca(2+), and then K(+). This ordering is found to be consistent with experimental observation. The calculations also make it possible to determine the possible penetration of metal ions into the clay's 2:1 crystalline layer. For the cases studied, this type of penetration can occur at elevated temperatures into regions where isomorphic substitution has occurred with metal ions that bear a formal charge of less than 3+. The computed behavior of the electronic structure in the presence of isomorphic substitution is found to be similar to behavior associated with semiconductors.

Analysis of Protein Thermostability Enhancing Factors in Industrially Important Thermus Bacteria Species

PubMed Central

Kumwenda, Benjamin; Litthauer, Derek; Bishop, Özlem Tastan; Reva, Oleg

2013-01-01

Elucidation of evolutionary factors that enhance protein thermostability is a critical problem and was the focus of this work on Thermus species. Pairs of orthologous sequences of T. scotoductus SA-01 and T. thermophilus HB27, with the largest negative minimum folding energy (MFE) as predicted by the UNAFold algorithm, were statistically analyzed. Favored substitutions of amino acids residues and their properties were determined. Substitutions were analyzed in modeled protein structures to determine their locations and contribution to energy differences using PyMOL and FoldX programs respectively. Dominant trends in amino acid substitutions consistent with differences in thermostability between orthologous sequences were observed. T. thermophilus thermophilic proteins showed an increase in non-polar, tiny, and charged amino acids. An abundance of alanine substituted by serine and threonine, as well as arginine substituted by glutamine and lysine was observed in T. thermophilus HB27. Structural comparison showed that stabilizing mutations occurred on surfaces and loops in protein structures. PMID:24023508

Nonsynonymous substitution in abalone sperm fertilization genes exceeds substitution in introns and mitochondrial DNA

PubMed Central

Metz, Edward C.; Robles-Sikisaka, Refugio; Vacquier, Victor D.

1998-01-01

Strong positive Darwinian selection acts on two sperm fertilization proteins, lysin and 18-kDa protein, from abalone (Haliotis). To understand the phylogenetic context for this dramatic molecular evolution, we obtained sequences of mitochondrial cytochrome c oxidase subunit I (mtCOI), and genomic sequences of lysin, 18-kDa, and a G protein subunit. Based on mtDNA differentiation, four north Pacific abalone species diverged within the past 2 million years (Myr), and remaining north Pacific species diverged over a period of 4–20 Myr. Between-species nonsynonymous differences in lysin and 18-kDa exons exceed nucleotide differences in introns by 3.5- to 24-fold. Remarkably, in some comparisons nonsynonymous substitutions in lysin and 18-kDa genes exceed synonymous substitutions in mtCOI. Lysin and 18-kDa intron/exon segments were sequenced from multiple red abalone individuals collected over a 1,200-km range. Only two nucleotide changes and two sites of slippage variation were detected in a total of >29,000 nucleotides surveyed. However, polymorphism in mtCOI and a G protein intron was found in this species. This finding suggests that positive selection swept one lysin allele and one 18-kDa allele to fixation. Similarities between mtCOI and lysin gene trees indicate that rapid adaptive evolution of lysin has occurred consistently through the history of the group. Comparisons with mtCOI molecular clock calibrations suggest that nonsynonymous substitutions accumulate 2–50 times faster in lysin and 18-kDa genes than in rapidly evolving mammalian genes. PMID:9724763

The effectiveness of opioid substitution treatments for patients with opioid dependence: a systematic review and multiple treatment comparison protocol

PubMed Central

2014-01-01

Background Opioids are psychoactive analgesic drugs prescribed for pain relief and palliative care. Due to their addictive potential, effort and vigilance in controlling prescriptions is needed to avoid misuse and dependence. Despite the effort, the prevalence of opioid use disorder continues to rise. Opioid substitution therapies are commonly used to treat opioid dependence; however, there is minimal consensus as to which therapy is most effective. Available treatments include methadone, heroin, buprenorphine, as well as naltrexone. This systematic review aims to assess and compare the effect of all available opioid substitution therapies on the treatment of opioid dependence. Methods/Design The authors will search Medline, EMBASE, PubMed, PsycINFO, Web of Science, Cochrane Library, Cochrane Clinical Trials Registry, World Health Organization International Clinical Trials Registry Platform Search Portal, and the National Institutes for Health Clinical Trials Registry. The title, abstract, and full-text screening will be completed in duplicate. When appropriate, multiple treatment comparison Bayesian meta-analytic methods will be performed to deduce summary statistics estimating the effectiveness of all opioid substitution therapies in terms of retention and response to treatment (as measured through continued opioid abuse). Discussion Using evidence gained from this systematic review, we anticipate disseminating an objective review of the current available literature on the effectiveness of all opioid substitution therapies for the treatment of opioid use disorder. The results of this systematic review are imperative to the further enhancement of clinical practice in addiction medicine. Systematic review registration PROSPERO CRD42013006507. PMID:25239213

Chronic Intermittent Ethanol Inhalation Increases Ethanol Self-administration in both C57BL/6J and DBA/2J Mice

PubMed Central

McCool, Brian A.; Chappell, Ann M.

2015-01-01

Inbred mouse strains provide significant opportunities to understand the genetic mechanisms controlling ethanol-directed behaviors and neurobiology. They have been specifically employed to understand cellular mechanisms contributing to ethanol consumption, acute intoxication, and sensitivities to chronic effects. However, limited ethanol consumption by some strains has restricted our understanding of clinically relevant endpoints such as dependence-related ethanol intake. Previous work with a novel tastant-substitution procedure using monosodium glutamate (MSG or umami flavor) has shown that the procedure greatly enhances ethanol consumption by mouse strains that express limited drinking phenotypes using other methods. In the current study, we employ this MSG-substitution procedure to examine how ethanol dependence, induced with passive vapor inhalation, modifies ethanol drinking in C57BL/6J and DBA/2J mice. These strains represent ‘high’ and ‘low’ drinking phenotypes, respectively. We found that the MSG substitution greatly facilitates ethanol drinking in both strains, and likewise, ethanol dependence increased ethanol consumption regardless of strain. However, DBA/2J mice exhibited greater sensitivity dependence-enhanced drinking, as represented by consumption behaviors directed at lower ethanol concentrations and relative to baseline intake levels. DBA/2J mice also exhibited significant withdrawal-associated anxiety-like behavior while C57BL/6J mice did not. These findings suggest that the MSG-substitution procedure can be employed to examine dependence-enhanced ethanol consumption across a range of drinking phenotypes, and that C57BL/6J and DBA/2J mice may represent unique neurobehavioral pathways for developing dependence-enhanced ethanol consumption. PMID:25659650

Cisplatin Binding to Biological Ligands Revealed at the Encounter Complex Level by IR Action Spectroscopy.

PubMed

Corinti, Davide; Coletti, Cecilia; Re, Nazzareno; Chiavarino, Barbara; Crestoni, Maria Elisa; Fornarini, Simonetta

2016-03-07

Cisplatin [cis-diamminedichloroplatinum(II)] was the first platinum-based antineoplastic agent and is still a cornerstone for the treatment of various solid tumors. Reactive events responsible for cisplatin activity are unveiled here at the molecular level. Simple ligands (L) representing ubiquitous functional groups in the biological environment likely to be encountered by administered cisplatin have been allowed to react with cis-[PtCl(NH3)2 (H2O)](+), the primary intermediate from cisplatin hydrolysis. The substitution reactions have been examined by a combined experimental and computational approach and the structural features of the substitution product, cis-[PtCl(NH3)2(L)](+), have been probed by IR multiple-photon dissociation (IRMPD) spectroscopy. Furthermore, IRMPD spectroscopy has been exploited to elucidate the structure of [PtCl(NH3)2(L)(H2O)](+) clusters, also obtained by electrospray ionization (ESI) from the aqueous solution and representing the major focus of this investigation. These ions conform to the encounter complex of cis-[PtCl(NH3)2 (H2O)](+) with the incoming ligand and represent the first direct evidence of a prototypical Eigen-Wilkins encounter complex in solution, lying on the reaction coordinate for ligand substitution and extracted by ESI for mass spectrometric analysis. Activated [PtCl(NH3)2(L)(H2O)](+) ions dissociate by the loss of either H2O or L, the former process implying a ligand substitution event. IRMPD spectroscopy has thus revealed both structural details and reaction dynamics at the level of the isolated encounter complex. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Xylan Side-Chain Substitutions on Xylan-Cellulose Interactions and Implications for Thermal Pretreatment of Cellulosic Biomass.

PubMed

Pereira, Caroline S; Silveira, Rodrigo L; Dupree, Paul; Skaf, Munir S

2017-04-10

Lignocellulosic biomass is mainly constituted by cellulose, hemicellulose, and lignin and represents an important resource for the sustainable production of biofuels and green chemistry materials. Xylans, a common hemicellulose, interact with cellulose and often exhibit various side chain substitutions including acetate, (4-O-methyl) glucuronic acid, and arabinose. Recent studies have shown that the distribution of xylan substitutions is not random, but follows patterns that are dependent on the plant taxonomic family and cell wall type. Here, we use molecular dynamics simulations to investigate the role of substitutions on xylan interactions with the hydrophilic cellulose face, using the recently discovered xylan decoration pattern of the conifer gymnosperms as a model. The results show that α-1,2-linked substitutions stabilize the binding of single xylan chains independently of the nature of the substitution and that Ca 2+ ions can mediate cross-links between glucuronic acid substitutions of two neighboring xylan chains, thus stabilizing binding. At high temperature, xylans move from the hydrophilic to the hydrophobic cellulose surface and are also stabilized by Ca 2+ cross-links. Our results help to explain the role of substitutions on xylan-cellulose interactions, and improve our understanding of the plant cell wall architecture and the fundamentals of biomass pretreatments.

Biochar as a substitute for vermiculite in potting mix for hybrid poplar

Treesearch

William L. Headlee; Catherine E. Brewer; Richard B. Hall

2014-01-01

The purpose of this study was to evaluate biochar as a substitute for vermiculite in potting mixes for unrooted vegetative cuttings of hybrid poplar as represented by the clone ‘NM6’ (Populus nigra L. × Populus suaveolens Fischer subsp. maximowiczii A. Henry). We compared three treatments (peat moss (control), peat moss mixed with vermiculite, and peat moss mixed with...

Pharmacological properties of ββ-dimethylacryloylcholine and some other β-substituted acryloylcholines

PubMed Central

Holmstedt, B.; Whittaker, V. P.

1958-01-01

The mammalian pharmacology of a new naturally occurring ester of choline, ββ-dimethylacryloylcholine (DMAC), has been studied, mainly in the cat, together with that of two synthetic β-substituted acryloylcholines, crotonoylcholine and pent-2-enoylcholine. Comparisons have been made with the reduced form of DMAC, isovalerylcholine, with another naturally ocurring β-substituted acryloylcholine, murexine (urocanoylcholine), and with suxamethonium. DMAC has been shown to be a ganglion stimulating and neuromuscular blocking agent generally similar, in potency and properties, to murexine. It is also a powerful respiratory stimulant. The other unsaturated esters behaved similarly but were less potent. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6 PMID:13584734

Rational Design Synthesis and Evaluation of New Selective Inhibitors of Microbial Class II (Zinc Dependent) Fructose Bis-phosphate Aldolases

DOE Office of Scientific and Technical Information (OSTI.GOV)

R Daher; M Coincon; M Fonvielle

2011-12-31

We report the synthesis and biochemical evaluation of several selective inhibitors of class II (zinc dependent) fructose bis-phosphate aldolases (Fba). The products were designed as transition-state analogues of the catalyzed reaction, structurally related to the substrate fructose bis-phosphate (or sedoheptulose bis-phosphate) and based on an N-substituted hydroxamic acid, as a chelator of the zinc ion present in active site. The compounds synthesized were tested on class II Fbas from various pathogenic microorganisms and, by comparison, on a mammalian class I Fba. The best inhibitor shows Ki against class II Fbas from various pathogens in the nM range, with very highmore » selectivity (up to 105). Structural analyses of inhibitors in complex with aldolases rationalize and corroborate the enzymatic kinetics results. These inhibitors represent lead compounds for the preparation of new synthetic antibiotics, notably for tuberculosis prophylaxis.« less

Single-cone finite-difference schemes for the (2+1)-dimensional Dirac equation in general electromagnetic textures

NASA Astrophysics Data System (ADS)

Pötz, Walter

2017-11-01

A single-cone finite-difference lattice scheme is developed for the (2+1)-dimensional Dirac equation in presence of general electromagnetic textures. The latter is represented on a (2+1)-dimensional staggered grid using a second-order-accurate finite difference scheme. A Peierls-Schwinger substitution to the wave function is used to introduce the electromagnetic (vector) potential into the Dirac equation. Thereby, the single-cone energy dispersion and gauge invariance are carried over from the continuum to the lattice formulation. Conservation laws and stability properties of the formal scheme are identified by comparison with the scheme for zero vector potential. The placement of magnetization terms is inferred from consistency with the one for the vector potential. Based on this formal scheme, several numerical schemes are proposed and tested. Elementary examples for single-fermion transport in the presence of in-plane magnetization are given, using material parameters typical for topological insulator surfaces.

Emergence of canine distemper virus strains with two amino acid substitutions in the haemagglutinin protein, detected from vaccinated carnivores in North-Eastern China in 2012-2013.

PubMed

Zhao, Jianjun; Zhang, Hailing; Bai, Xue; Martella, Vito; Hu, Bo; Sun, Yangang; Zhu, Chunsheng; Zhang, Lei; Liu, Hao; Xu, Shujuan; Shao, Xiqun; Wu, Wei; Yan, Xijun

2014-04-01

A total of 16 strains of canine distemper virus (CDV) were detected from vaccinated minks, foxes, and raccoon dogs in four provinces in North-Eastern China between the end of 2011 and 2013. Upon sequence analysis of the haemagglutinin gene and comparison with wild-type CDV from different species in the same geographical areas, two non-synonymous single nucleotide polymorphisms were identified in 10 CDV strains, which led to amino acid changes at positions 542 (isoleucine to asparagine) and 549 (tyrosine to histidine) of the haemagglutinin protein coding sequence. The change at residue 542 generated a potentially novel N-glycosylation site. Masking of antigenic epitopes by sugar moieties might represent a mechanism for evasion of virus neutralising antibodies and reduced protection by vaccination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Interstitial Fe in MgO

NASA Astrophysics Data System (ADS)

Mølholt, T. E.; Mantovan, R.; Gunnlaugsson, H. P.; Svane, A.; Masenda, H.; Naidoo, D.; Bharuth-Ram, K.; Fanciulli, M.; Gislason, H. P.; Johnston, K.; Langouche, G.; Ólafsson, S.; Sielemann, R.; Weyer, G.

2014-01-01

Isolated 57Fe atoms were studied in MgO single-crystals by emission Mössbauer spectroscopy following implantation of 57Mn decaying to 57Fe. Four Mössbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe2+ and Fe3+, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.

Diversification and the rate of molecular evolution: no evidence of a link in mammals.

PubMed

Goldie, Xavier; Lanfear, Robert; Bromham, Lindell

2011-10-04

Recent research has indicated a positive association between rates of molecular evolution and diversification in a number of taxa. However debate continues concerning the universality and cause of this relationship. Here, we present the first systematic investigation of this relationship within the mammals. We use phylogenetically independent sister-pair comparisons to test for a relationship between substitution rates and clade size at a number of taxonomic levels. Total, non-synonymous and synonymous substitution rates were estimated from mitochondrial and nuclear DNA sequences. We found no evidence for an association between clade size and substitution rates in mammals, for either the nuclear or the mitochondrial sequences. We found significant associations between body size and substitution rates, as previously reported. Our results present a contrast to previous research, which has reported significant positive associations between substitution rates and diversification for birds, angiosperms and reptiles. There are three possible reasons for the differences between the observed results in mammals versus other clades. First, there may be no link between substitution rates and diversification in mammals. Second, this link may exist, but may be much weaker in mammals than in other clades. Third, the link between substitution rates and diversification may exist in mammals, but may be confounded by other variables.

Comparison of the discriminative stimulus effects of dimethyltryptamine with different classes of psychoactive compounds in rats.

PubMed

Gatch, Michael B; Rutledge, Margaret A; Carbonaro, Theresa; Forster, Michael J

2009-07-01

There has been increased recreational use of dimethyltryptamine (DMT), but little is known of its discriminative stimulus effects. The present study assessed the similarity of the discriminative stimulus effects of DMT to other types of hallucinogens and to psychostimulants. Rats were trained to discriminate DMT from saline. To test the similarity of DMT to known hallucinogens, the ability of (+)-lysergic acid diethylamide (LSD), (-)-2,5-dimethoxy-4-methylamphetamine (DOM), (+)-methamphetamine, or (+/-)3,4-methylenedioxymethyl amphetamine (MDMA) to substitute in DMT-trained rats was tested. The ability of DMT to substitute in rats trained to discriminate each of these compounds was also tested. To assess the degree of similarity in discriminative stimulus effects, each of the compounds was tested for substitution in all of the other training groups. LSD, DOM, and MDMA all fully substituted in DMT-trained rats, whereas DMT fully substituted only in DOM-trained rats. Full cross-substitution occurred between DMT and DOM, LSD and DOM, and (+)-methamphetamine and MDMA. MDMA fully substituted for (+)-methamphetamine, DOM, and DMT, but only partially for LSD. In MDMA-trained rats, LSD and (+)-methamphetamine fully substituted, whereas DMT and DOM did not fully substitute. No cross-substitution was evident between (+)-methamphetamine and DMT, LSD, or DOM. DMT produces discriminative stimulus effects most similar to those of DOM, with some similarity to the discriminative stimulus effects of LSD and MDMA. Like DOM and LSD, DMT seems to produce predominately hallucinogenic-like discriminative stimulus effects and minimal psychostimulant effects, in contrast to MDMA which produced hallucinogen- and psychostimulant-like effects.

Comparison of advanced therapy medicinal product gingiva and skin substitutes and their in vitro wound healing potentials

PubMed Central

Boink, Mireille A.; Roffel, Sanne; Breetveld, Melanie; Thon, Maria; Haasjes, Michiel S.P.; Waaijman, Taco; Scheper, Rik J.; Blok, Chantal S.

2017-01-01

Abstract Skin and oral mucosa substitutes are a therapeutic option for closing hard‐to‐heal skin and oral wounds. Our aim was to develop bi‐layered skin and gingiva substitutes, from 3 mm diameter biopsies, cultured under identical conditions, which are compliant with current European regulations for advanced therapy medicinal products. We present in vitro mode of action methods to (i) determine viability: epithelial expansion, proliferation (Ki‐67), metabolic activity (MTT assay); (ii) characterize skin and gingiva substitutes: histology and immunohistochemistry; and (iii) determine potency: soluble wound healing mediator release (enzyme‐linked immunosorbent assay). Both skin and gingiva substitutes consist of metabolically active autologous reconstructed differentiated epithelium expanding from the original biopsy sheet on a fibroblast populated connective tissue matrix (donor dermis). Gingival epithelium expanded 1.7‐fold more than skin epithelium during the 3 week culture period. The percentage of proliferating Ki‐67‐positive cells located in the basal layer of the gingiva substitute was >1.5‐fold higher than in the skin substitute. Keratins 16 and 17, which are upregulated during normal wound healing, were expressed in both the skin and gingiva substitutes. Notably, the gingiva substitute secreted higher amounts of key cytokines involved in mitogenesis, motogenesis and chemotaxis (interleukin‐6 > 23‐fold, CXCL8 > 2.5‐fold) as well as higher amounts of the anti‐fibrotic growth factor, hepatocyte growth factor (>7‐fold), compared with the skin substitute. In conclusion, while addressing the viability, characterization and potency of the tissue substitutes, important intrinsic differences between skin and gingiva were discovered that may explain in part the superior quality of wound healing observed in the oral mucosa compared with skin. PMID:28388010

Distinct molecular structures and hydrogen bond patterns of α,α-diethyl-substituted cyclic imide, lactam, and acetamide derivatives in the crystalline phase

NASA Astrophysics Data System (ADS)

Krivoshein, Arcadius V.; Ordonez, Carlos; Khrustalev, Victor N.; Timofeeva, Tatiana V.

2016-10-01

α,α-Dialkyl- and α-alkyl-α-aryl-substituted cyclic imides, lactams, and acetamides show promising anticonvulsant, anxiolytic, and anesthetic activities. While a number of crystal structures of various α-substituted cyclic imides, lactams, and acetamides were reported, no in-depth comparison of crystal structures and solid-state properties of structurally matched compounds have been carried out so far. In this paper, we report molecular structure and intermolecular interactions of three α,α-diethyl-substituted compounds - 3,3-diethylpyrrolidine-2,5-dione, 3,3-diethylpyrrolidin-2-one, and 2,2-diethylacetamide - in the crystalline phase, as studied using single-crystal X-ray diffraction and IR spectroscopy. We found considerable differences in the patterns of H-bonding and packing of the molecules in crystals. These differences correlate with the compounds' melting points and are of significance to physical pharmacy and formulation development of neuroactive drugs.

Development of a wheat-Aegilops searsii substitution line with positively affecting Chinese steamed bread quality

PubMed Central

Du, Xuye; Ma, Xin; Min, Jingzhi; Zhang, Xiaocun; Jia, Zhenzhen

2018-01-01

A wheat-Aegilops searsii substitution line GL1402, in which chromosome 1B was substituted with 1Ss from Ae. searsii, was developed and detected using SDS-PAGE and GISH. The SDS-PAGE analysis showed that the HMW-GS encoded by the Glu-B1 loci of Chinese Spring was replaced by the HMW-GS encoded by the Glu-1Ss loci of Ae. searsii. Glutenin macropolymer (GMP) investigation showed that GL1402 had a much higher GMP content than Chinese Spring did. A dough quality comparison of GL1402 and Chinese Spring indicated that GL1402 showed a significantly higher protein content and middle peak time (MPT), and a smaller right peak slope (RPS). Quality tests of Chinese steamed bread (CSB) showed that the GL1402 also produced good steamed bread quality. These results suggested that the substitution line is a valuable breeding material for improving the wheat processing quality.

Thermoelectric properties of n-type double substituted SrTiO3 bulk materials.

PubMed

Cui, Yanjie; He, Jian; Amow, Gisele; Kleinke, Holger

2010-01-28

A series of La, Ta double substituted Sr(1-x)La(x)Ti(1-x)Ta(x)O(3), with x = 0.01, 0.05 and 0.10, and La, Nb double substituted Sr(0.90)La(0.10)Ti(0.90)Nb(0.10)O(3) for comparison were investigated in this project. Rietveld refinements were performed to check for purity and symmetry reduction. Electronic structure calculations indicate n-type conduction with steep and flat bands in the vicinity of the Fermi level for x = 0.125. Seebeck coefficient, electrical conductivity, and thermal conductivity measurements on hot-pressed and spark-plasma-sintered samples were performed over a wide range of temperatures. Best results were obtained by spark-plasma-sintering of double substituted Sr(0.99)La(0.01)Ti(0.99)Ta(0.01)O(3) with a thermoelectric figure-of-merit of 0.13 at 660 K.

Density impact on performance of composite Si/graphite electrodes

DOE PAGES

Dufek, Eric J.; Picker, Michael; Petkovic, Lucia M.

2016-01-27

The ability of alkali-substituted binders for composite Si and graphite negative electrodes to minimize capacity fade for lithium ion batteries is investigated. Polymer films and electrodes are described and characterized by FTIR following immersion in electrolyte (1:2 EC:DMC) for 24 h. FTIR analysis following electrode formation displayed similar alkali-ion dependent shifts in peak location suggesting that changes in the vibrational structure of the binder are maintained after electrode formation. The Si and graphite composite electrodes prepared using the alkali-substituted polyacrylates were also exposed to electrochemical cycling and it has been found that the performance of the Na-substituted binder is superiormore » to a comparable density K-substituted system. However, in comparing performance across many different electrode densities attention needs to be placed on making comparisons at similar densities, as low density electrodes tend to exhibit lower capacity fade over cycling. This is highlighted by a 6% difference between a low density K-substituted electrode and a high density Na-substituted sample. As a result, this low variance between the two systems makes it difficult to quickly make a direct evaluation of binder performance unless electrode density is tightly controlled.« less

[Sugar of substitute stevioside in chewing gum: comparative double blind controllable study].

PubMed

Rumiantsev, V A; Beliaev, V V; Zubtsov, V A; Esaian, L K; Namestnikova, I V

2011-01-01

In double blind controllable study on 126 volunteers - students of medical academy - influence on рН the mixed saliva of 5 kinds of chewing gums with the different contents of substitute of sugar as xylitol and sorbitol, and also the chewing sweets R.O.C.S., two kinds of chewing gums containing a basis with substitute of sugar stevioside (1.25 and 2.5%) and placebo (a basis without additives) were investigated. Products chewed within 10 minutes. In one of groups surveyed such chewing was preceded with rinsing a mouth by a test solution of saccharose. рН determined within 30 minutes. At chewing gums with substitute of sugar displacement рН the mixed saliva in the alkaline side was revealed a different degree. Thus gums with stevioside did not concede and even surpassed in this action of chewing gums with other substitutes of sugar. In comparison with placebo chewing gums and sweets restored acid-alkaline balance of oral cavities faster. Hence, use of stevioside in structure of chewing gum allows at preservation of its positive actions in oral cavity essentially to reduce concentration substitute of sugar and, hence, its collateral action by an organism.

Variation of p53 mutational spectra between carcinoma of the upper and lower respiratory tract.

PubMed

Law, J C; Whiteside, T L; Gollin, S M; Weissfeld, J; El-Ashmawy, L; Srivastava, S; Landreneau, R J; Johnson, J T; Ferrell, R E

1995-07-01

Mutations of the p53 tumor suppressor gene are the most common genetic alterations associated with human cancer. Tumor-associated p53 mutations often show characteristic tissue-specific profiles which may infer environmentally induced mutational mechanisms. The p53 mutational frequency and spectrum were determined for 95 carcinomas of the upper and lower respiratory tract (32 lung and 63 upper respiratory tract). Mutations were identified at a frequency of 30% in upper respiratory tract (URT) tumors and 31% in lung tumors. All 29 identified mutations were single-base substitutions. Comparison of the frequency of specific base substitutions between lung and URT showed a striking difference. Transitions occurred at a frequency of 68% in URT, but only 30% in lung. Mutations involving G:C-->A:T transitions, which are commonly reported in gastric and esophageal tumors, were the most frequently identified alteration in URT (11/19). Mutations involving G:C-->T:A transversions, which were relatively common in lung tumors (3/10) and are representative of tobacco smoke-induced mutations were rare in URT tumors (1/19). Interestingly, G:C-->A:T mutations at CpG sites, which are characteristic of endogenous processes, were observed frequently in URT tumors (9/19) but only rarely in lung tumors (1/10), suggesting that both endogenous and exogenous factors are responsible for the observed differences in mutational spectra between the upper and lower respiratory systems.

Genome Alignment Spanning Major Poaceae Lineages Reveals Heterogeneous Evolutionary Rates and Alters Inferred Dates for Key Evolutionary Events.

PubMed

Wang, Xiyin; Wang, Jingpeng; Jin, Dianchuan; Guo, Hui; Lee, Tae-Ho; Liu, Tao; Paterson, Andrew H

2015-06-01

Multiple comparisons among genomes can clarify their evolution, speciation, and functional innovations. To date, the genome sequences of eight grasses representing the most economically important Poaceae (grass) clades have been published, and their genomic-level comparison is an essential foundation for evolutionary, functional, and translational research. Using a formal and conservative approach, we aligned these genomes. Direct comparison of paralogous gene pairs all duplicated simultaneously reveal striking variation in evolutionary rates among whole genomes, with nucleotide substitution slowest in rice and up to 48% faster in other grasses, adding a new dimension to the value of rice as a grass model. We reconstructed ancestral genome contents for major evolutionary nodes, potentially contributing to understanding the divergence and speciation of grasses. Recent fossil evidence suggests revisions of the estimated dates of key evolutionary events, implying that the pan-grass polyploidization occurred ∼96 million years ago and could not be related to the Cretaceous-Tertiary mass extinction as previously inferred. Adjusted dating to reflect both updated fossil evidence and lineage-specific evolutionary rates suggested that maize subgenome divergence and maize-sorghum divergence were virtually simultaneous, a coincidence that would be explained if polyploidization directly contributed to speciation. This work lays a solid foundation for Poaceae translational genomics. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

Changes in Ultrasonic Velocity from Fluid Substitution, Calculated with Laboratory Methods, Digital Rock Physics, and Biot Theory

NASA Astrophysics Data System (ADS)

Goldfarb, E. J.; Ikeda, K.; Tisato, N.

2017-12-01

Seismic and ultrasonic velocities of rocks are function of several variables including fluid saturation and type. Understanding the effect of each variable on elastic waves can be valuable when using seismic methods for subsurface modeling. Fluid type and saturation are of specific interest to volcanology, water, and hydrocarbon exploration. Laboratory testing is often employed to understand the effects of fluids on elastic waves. However, laboratory testing is expensive and time consuming. It normally requires cutting rare samples into regular shapes. Fluid injection can also destroy specimens as removing the fluid after testing can prove difficult. Another option is theoretical modeling, which can be used to predict the effect of fluids on elastic properties, but it is often inaccurate. Alternatively, digital rock physics (DRP) can be used to investigate the effect of fluid substitution. DRP has the benefit of being non invasive, as it does not require regular sample shapes or fluid injection. Here, we compare the three methods for dry and saturated Berea sandstone to test the reliability of DRP. First, ultrasonic velocities were obtained from laboratory testing. Second, for comparison, we used a purely theoretical approach - i.e., Hashin-Shtrikman and Biot theory - to estimate the wave speeds at dry and wet conditions. Third, we used DRP. The dry sample was scanned with micro Computed Tomography (µCT), and a three dimensional (3D) array was recorded. We employed a segmentation-less method to convert each 3D array value to density, porosity, elastic moduli, and wave speeds. Wave propagation was simulated numerically at similar frequency as the laboratory. To simulate fluid substitution, we numerically substituted air values for water and repeated the simulation. The results from DRP yielded similar velocities to the laboratory, and accurately predicted the velocity change from fluid substitution. Theoretical modeling could not accurately predict velocity, and under-predicted the velocity change from fluid substitution. The mathematical approach proved to be a poor comparison for the laboratory measurement. DRP proved to be effective, and could be used in future with drill cuttings, perhaps to limit the use of expensive cores. DRP could also limit the requirement for physically testing fluid substitution.

[Pd(μ-Cl)Cl(IPr*)]2: a highly hindered pre-catalyst for the synthesis of tetra-ortho-substituted biaryls via Grignard reagent cross-coupling.

PubMed

Lesieur, Mathieu; Slawin, Alexandra M Z; Cazin, Catherine S J

2014-08-14

The new well-defined catalyst [Pd(μ-Cl)Cl(IPr*)]2 enables the efficient Grignard reagent cross-coupling for the synthesis of tetra-ortho-substituted biaryls. The high reactivity of the complex is associated with the important bulkiness of the IPr* ligand. The dimer represents the most efficient catalyst reported to date for this challenging transformation.

Regioselective and enantiospecific rhodium-catalyzed allylic alkylation reactions using copper(I) enolates: synthesis of (-)-sugiresinol dimethyl ether.

PubMed

Evans, P Andrew; Leahy, David K

2003-07-30

The transition metal-catalyzed allylic alkylation represents a fundamentally important cross-coupling reaction for the construction of ternary carbon stereogenic centers. We have developed a regioselective and enantiospecific rhodium-catalyzed allylic alkylation of acyclic unsymmetrical allylic alcohol derivatives using copper(I) enolates to prepare beta-substituted ketones. This protocol represents a convenient asymmetric Claisen rearrangement surrogate in which alpha-substituted enolates permit the introduction of an additional stereogenic center. The synthetic utility of this transformation was highlighted in the construction of a trans-1,2-disubstituted cyclohexene and the total synthesis of (-)-sugiresinol dimethyl ether. Finally, we anticipate that copper(I) enolates may prove useful nucleophiles in related metal-catalyzed reactions.

Chronic intermittent ethanol inhalation increases ethanol self-administration in both C57BL/6J and DBA/2J mice.

PubMed

McCool, Brian A; Chappell, Ann M

2015-03-01

Inbred mouse strains provide significant opportunities to understand the genetic mechanisms controlling ethanol-directed behaviors and neurobiology. They have been specifically employed to understand cellular mechanisms contributing to ethanol consumption, acute intoxication, and sensitivities to chronic effects. However, limited ethanol consumption by some strains has restricted our understanding of clinically relevant endpoints such as dependence-related ethanol intake. Previous work with a novel tastant-substitution procedure using monosodium glutamate (MSG or umami flavor) has shown that the procedure greatly enhances ethanol consumption by mouse strains that express limited drinking phenotypes using other methods. In the current study, we employ this MSG-substitution procedure to examine how ethanol dependence, induced with passive vapor inhalation, modifies ethanol drinking in C57BL/6J and DBA/2J mice. These strains represent 'high' and 'low' drinking phenotypes, respectively. We found that the MSG substitution greatly facilitates ethanol drinking in both strains, and likewise, ethanol dependence increased ethanol consumption regardless of strain. However, DBA/2J mice exhibited greater sensitivity dependence-enhanced drinking, as represented by consumption behaviors directed at lower ethanol concentrations and relative to baseline intake levels. DBA/2J mice also exhibited significant withdrawal-associated anxiety-like behavior while C57BL/6J mice did not. These findings suggest that the MSG-substitution procedure can be employed to examine dependence-enhanced ethanol consumption across a range of drinking phenotypes, and that C57BL/6J and DBA/2J mice may represent unique neurobehavioral pathways for developing dependence-enhanced ethanol consumption. Copyright © 2015 Elsevier Inc. All rights reserved.

Modeling the SOA Forming Potential of Substituted Dihydrofurans from Alkane + OH Reactions in the Atmosphere

NASA Astrophysics Data System (ADS)

Jordan, C. E.; Griffin, R. J.; Lim, Y. B.; Ziemann, P. J.; Atkinson, R.; Arey, J.

2005-12-01

Recent laboratory studies show that δ-hydroxycarbonyls formed in the atmosphere via OH-initiated reactions with alkanes can cyclize then dehydrate to form substituted dihydrofurans. These dihydrofurans are highly reactive, with lifetimes in the atmosphere of 1.3 h (OH), 24 s (NO3), and 7 min (O3). The ability of the δ-hydroxycarbonyls to cyclize and dehydrate has been shown to increase with increasing carbon number. Recent laboratory results show that the secondary organic aerosol (SOA) yields from alkanes also increase with carbon number reaching ~53% for C15. The reaction mechanism proposed based on the chamber results is the basis of the modeling study presented here. We have incorporated this proposed mechanism into the Caltech Atmospheric Chemistry Mechanism (CACM). For computational reasons, similar compounds are lumped together and represented by a single suitable compound. In the present case, alkanes are lumped into 3 groups: short chains (≤C6), medium chains (C7 - C12), and long chains (≥C13). SOA yields obtained in chamber studies increase dramatically from 0.5% for C8 to 25% for C12. The most dramatic increase is observed from C11 (8%) to C13 (~50%). This is attributed to the low volatility of first generation products contributing to the SOA from longer chain alkanes. Here we have studied OH reactions with the substituted dihydrofurans for medium (represented by C10) and long (represented by C16) chain alkanes using CACM along with the aerosol partitioning module MPMPO (Model to Predict the Multi-phase Partitioning of Organics). We will present the results of this modeling study, characterizing the influence of substituted dihydrofurans on the SOA forming potential of alkanes.

Human Origins: Problems in the Interpretation of New Evidence. Third Edition. AAAS Study Guides on Contemporary Problems.

ERIC Educational Resources Information Center

Almquist, Alan J.; Cronin, John E.

This Chautauqua-type short course in human evolution is divided into two parts: The Biochemical Evidence for Human Evolution, and the Fossil Evidence for Human Evolution. The first part covers the comparison of macromolecular differences between species. This includes comparison of DNA base-ratios and amino acid substitution in enzymes and other…

Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Compounds and Their Ions. 7; Phenazine, a Dual Substituted Polycyclic Aromatic Nitrogen Heterocycle

NASA Technical Reports Server (NTRS)

Mattioda, A. L.; Hudgins, D. M.; Bauschlicher, C. W., Jr.; Allamandola, L. J.

2004-01-01

The matrix-isolation technique has been employed to measure the mid-infrared spectra of phenazine (C12H8N2), a dual substituted Polycyclic Aromatic Nitrogen Heterocycle (PANH), in the neutral, cationic and anionic forms. The experimentally measured band frequencies and intensities are tabulated and compared with their calculated values as well as those of the non-substituted parent molecule, anthracene. The theoretical band positions and intensities were calculated using both the 3-31 G as well as the larger 6-3lG* Basis Sets. A comparison of the results can be found in the tables. The spectroscopic properties of phenazine and its cation are similar to those observed in mono-substituted PANHs, with one exception. The presence of a second nitrogen atom results in an additional enhancement of the cation's total integrated intensity, for the 1500-1000 cm(sup -1) (6.7 to 10 micron) region, over that observed for a mono-substituted PANH cation. The significance of this enhancement and the astrobiological implications of these results are discussed.

Comparison of the effectiveness of two different bone substitute materials for socket preservation after tooth extraction: a controlled clinical study.

PubMed

Shakibaie-M, Behnam

2013-01-01

The aim of this study was to compare the effectiveness of two bone substitute materials for socket preservation after tooth extraction. Extraction sockets in 10 patients were filled with either inorganic bovine bone material (Bio-Oss) or with synthetic material consisting of hydroxyapatite and silicon dioxide (NanoBone). Extraction sockets without filling served as the control. The results demonstrate the effectiveness of the presented protocol for socket preservation and that the choice of a suitable bone substitute material is crucial. The dimensions of the alveolar ridge were significantly better preserved with Bio-Oss than with NanoBone or without treatment. Bio-Oss treatment resulted in better bone quality and quantity for successful implant placement.

Nonsynonymous substitution rate heterogeneity in the peptide-binding region among different HLA-DRB1 lineages in humans.

PubMed

Yasukochi, Yoshiki; Satta, Yoko

2014-05-02

An extraordinary diversity of amino acid sequences in the peptide-binding region (PBR) of human leukocyte antigen [HLA; human major histocompatibility complex (MHC)] molecules has been maintained by balancing selection. The process of accumulation of amino acid diversity in the PBR for six HLA genes (HLA-A, B, C, DRB1, DQB1, and DPB1) shows that the number of amino acid substitutions in the PBR among alleles does not linearly correlate with the divergence time of alleles at the six HLA loci. At these loci, some pairs of alleles show significantly less nonsynonymous substitutions at the PBR than expected from the divergence time. The same phenomenon was observed not only in the HLA but also in the rat MHC. To identify the cause for this, DRB1 sequences, a representative case of a typical nonlinear pattern of substitutions, were examined. When the amino acid substitutions in the PBR were placed with maximum parsimony on a maximum likelihood tree based on the non-PBR substitutions, heterogeneous rates of nonsynonymous substitutions in the PBR were observed on several branches. A computer simulation supported the hypothesis that allelic pairs with low PBR substitution rates were responsible for the stagnation of accumulation of PBR nonsynonymous substitutions. From these observations, we conclude that the nonsynonymous substitution rate at the PBR sites is not constant among the allelic lineages. The deceleration of the rate may be caused by the coexistence of certain pathogens for a substantially long time during HLA evolution. Copyright © 2014 Yasukochi and Satta.

Comparison of the Discriminative Stimulus Effects of Dimethyltryptamine with Different Classes of Psychoactive Compounds in Rats

PubMed Central

Gatch, Michael B.; Rutledge, Margaret A.; Carbonaro, Theresa; Forster, Michael J.

2010-01-01

Rationale There has been increased recreational use of dimethyltryptamine (DMT), but little is known of its discriminative stimulus effects. Objectives The present study assessed the similarity of the discriminative stimulus effects of DMT to other types of hallucinogens and to psychostimulants. Methods Rats were trained to discriminate DMT from saline. To test the similarity of DMT to known hallucinogens, the ability of (+)-lysergic acid diethylamide (LSD), (−)-2,5-dimethoxy-4-methylamphetamine (DOM), (+)-methamphetamine, or (±)3,4-methylenedioxymethyl-amphetamine (MDMA) to substitute in DMT-trained rats was tested. The ability of DMT to substitute in rats trained to discriminate each of these compounds was also tested. To assess the degree of similarity in discriminative stimulus effects, each of the compounds was tested for substitution in all of the other training groups. Results LSD, DOM, and MDMA all fully substituted in DMT-trained rats, whereas DMT fully substituted only in DOM-trained rats. Full cross-substitution occurred between DMT and DOM, LSD and DOM, and (+)-methamphetamine and MDMA. MDMA fully substituted for (+)-methamphetamine, DOM, and DMT, but only partially for LSD. In MDMA-trained rats, LSD and (+)-methamphetamine fully substituted, whereas DMT and DOM did not fully substitute. No cross-substitution was evident between (+)-methamphetamine and DMT, LSD, or DOM. Conclusions DMT produces discriminative stimulus effects most similar to those of DOM, with some similarity to the discriminative stimulus effects of LSD and MDMA. Like DOM and LSD, DMT seems to produce predominately hallucinogenic-like discriminative stimulus effects and minimal psychostimulant effects, in contrast to MDMA which produced hallucinogen- and psychostimulant-like effects. PMID:19288085

Subtype specific internalization of P2Y1 and P2Y2 receptors induced by novel adenosine 5′-O-(1-boranotriphosphate) derivatives

PubMed Central

Tulapurkar, M E; Laubinger, W; Nahum, V; Fischer, B; Reiser, G

2004-01-01

P2Y-nucleotide receptors represent important targets for drug development. The lack of stable and receptor specific agonists, however, has prevented successful therapeutic applications. A novel series of P-boronated ATP derivatives (ATP-α-B) were synthesized by substitution of a nonbridging O at Pα with a BH3 group. This introduces a chiral center, thus resulting in diastereoisomers. In addition, at C2 of the adenine ring a further substitution was made (Cl- or methylthio-). The pairs of diastereoisomers were denoted here as A and B isomers. Here, we tested the receptor subtype specificity of these analogs on HEK 293 cells stably expressing rat P2Y1 and rat P2Y2 receptors, respectively, both attached to the fluorescent marker protein GFP (rP2Y1-GFP, rP2Y2-GFP). We investigated agonist-induced receptor endocytosis, [Ca2+]i rise and arachidonic acid (AA) release. Agonist-induced endocytosis of rP2Y1-GFP was more pronounced for the A isomers than the corresponding B counterparts for all ATP-α-B analogs. Both 2-MeS-substituted diastereoisomers induced a greater degree of agonist-induced receptor endocytosis as compared to the 2-Cl-substituted derivatives. Endocytosis results are in accordance with the potency to induce Ca2+ release by these compounds in HEK 293 cells stably transfected with rP2Y1. In case of rP2Y2-GFP, the borano-nucleotides were very weak agonists in comparison to UTP and ATP in terms of Ca2+ release, AA release and in inducing receptor endocytosis. The different ATP-α-B derivatives and also the diastereoisomers were equally ineffective. Thus, the new agonists may be considered as potent and highly specific agonist drug candidates for P2Y1 receptors. The difference in activity of the ATP analogs at P2Y receptors could be used as a tool to investigate structural differences between P2Y receptor subtypes. PMID:15197109

Quantitation of base substitutions in eukaryotic 5S rRNA: selection for the maintenance of RNA secondary structure.

PubMed

Curtiss, W C; Vournakis, J N

1984-01-01

Eukaryotic 5S rRNA sequences from 34 diverse species were compared by the following method: (1) The sequences were aligned; (2) the positions of substitutions were located by comparison of all possible pairs of sequences; (3) the substitution sites were mapped to an assumed general base pairing model; and (4) the R-Y model of base stacking was used to study stacking pattern relationships in the structure. An analysis of the sequence and structure variability in each region of the molecule is presented. It was found that the degree of base substitution varies over a wide range, from absolute conservation to occurrence of over 90% of the possible observable substitutions. The substitutions are located primarily in stem regions of the 5S rRNA secondary structure. More than 88% of the substitutions in helical regions maintain base pairing. The disruptive substitutions are primarily located at the edges of helical regions, resulting in shortening of the helical regions and lengthening of the adjacent nonpaired regions. Base stacking patterns determined by the R-Y model are mapped onto the general secondary structure. Intrastrand and interstrand stacking could stabilize alternative coaxial structures and limit the conformational flexibility of nonpaired regions. Two short contiguous regions are 100% conserved in all species. This may reflect evolutionary constraints imposed at the DNA level by the requirement for binding of a 5S gene transcription initiation factor during gene expression.

Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Hui; Lu, Xu; Morelli, Donald T.

Boron-added CoSi, CoSi 0.98B 0.02, possesses a very high thermoelectric power factor of 60 μW cm -1 K -2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms are intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi 0.98B 0.02 has been studied. Here we present a study of themore » substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands while Ge substitution only shifts the Fermi level upward into the conduction band. Lastly, our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.« less

Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

DOE PAGES

Sun, Hui; Lu, Xu; Morelli, Donald T.

2016-07-21

Boron-added CoSi, CoSi 0.98B 0.02, possesses a very high thermoelectric power factor of 60 μW cm -1 K -2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms are intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi 0.98B 0.02 has been studied. Here we present a study of themore » substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands while Ge substitution only shifts the Fermi level upward into the conduction band. Lastly, our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.« less

Using Hyperfine Structure to Quantify the Effects of Substitution on the Electron Distribution Within a Pyridine Ring: a Study of 2-, 3-, and 4-PICOLYLAMINE

NASA Astrophysics Data System (ADS)

McDivitt, Lindsey M.; Himes, Korrina M.; Bailey, Josiah R.; McMahon, Timothy J.; Bird, Ryan G.

2017-06-01

The ground state rotational spectra of the three methylamine substituted pyridines, 2-, 3-, and 4-picolylamine, were collected and analyzed over the frequency range of 7-17.5 GHz using chirped-pulsed Fourier transform microwave spectroscopy. All three molecules show a distinctive quadrupole splitting, which is representative of the local electronic environment around the two different ^{14}N nuclei, with the pyridine nitrogen being particularly sensitive to the pi-electron distribution within the ring. The role that the position of the methylamine group plays on the quadrupole coupling constants on both nitrogens will be discussed and compared to other substituted pyridines.

Chromobacterium violaceum ω-transaminase variant Trp60Cys shows increased specificity for (S)-1-phenylethylamine and 4'-substituted acetophenones, and follows Swain-Lupton parameterisation.

PubMed

Cassimjee, Karim Engelmark; Humble, Maria Svedendahl; Land, Henrik; Abedi, Vahak; Berglund, Per

2012-07-28

For biocatalytic production of pharmaceutically important chiral amines the ω-transaminase enzymes have proven useful. Engineering of these enzymes has to some extent been accomplished by rational design, but mostly by directed evolution. By use of a homology model a key point mutation in Chromobacterium violaceum ω-transaminase was found upon comparison with engineered variants from homologous enzymes. The variant Trp60Cys gave increased specificity for (S)-1-phenylethylamine (29-fold) and 4'-substituted acetophenones (∼5-fold). To further study the effect of the mutation the reaction rates were Swain-Lupton parameterised. On comparison with the wild type, reactions of the variant showed increased resonance dependence; this observation together with changed pH optimum and cofactor dependence suggests an altered reaction mechanism.

Catalysts For Hydrogenation And Hydrosilylation Methods Of Making And Using The Same

DOEpatents

Dioumaev, Vladimir K.; Bullock, R. Morris

2004-05-18

A compound is provided including an organometallic complex represented by the formula I: wherein M is an atom of molybdenum or tangsten, Cp is substituted or unsubstituted cyclopentadienyl radical represented by the formula [C.sub.5 Q.sup.1 Q.sup.2 Q.sup.3 Q.sup.4 Q.sup.5 ], wherein Q.sup.1 to Q.sup.5 are independently selected from the group consisting of H radical, C.sub.1-20 hydrocarbyl radical, substituted hydrocarbyl radical, halogen radical, halogen-substituted hydrocarbyl radical, --OR, --C(O)R', --CO.sub.2 R', --SiR'.sub.3 and --NR'R", wherein R' and R" are independently selected from the group consisting of H radical, C.sub.1-20 hydrocarbyl radical, halogen radical, and halogen-substituted hydrocarbyl radical, wherein said Q.sup.1 to Q.sup.5 radicals are optionally linked to each other to form a stable bridging group, NHC is any N-heterocyclic carbene ligand, L is either any neutral electron donor ligand, wherein k is a number from 0 to 1 or L is an anionic ligand wherein k is 2, and A.sup.- is an anion. Processes using the organometallic complex as catalyst for hydrogenation of aldehydes and ketones are provided. Processes using the organometallic complex as catalyst for the hydrosilylation of aldehydes, ketones and esters are also provided.

Tautomerization and Dimerization of 6,13-Disubstituted Derivatives of Pentacene.

PubMed

Garcia-Borràs, Marc; Konishi, Akihito; Waterloo, Andreas; Liang, Yong; Cao, Yang; Hetzer, Constantin; Lehnherr, Dan; Hampel, Frank; Houk, Kendall N; Tykwinski, Rik R

2017-05-02

Two new 6,13-disubstituted pentacene derivatives, 1 c and 1 d, with alkyl and triisopropylsilylethynyl substitution have been synthesized and characterized experimentally and computationally. The alkyl substituted 1 c and 1 d represent the first 6-alkyl-substituted pentacene derivative where the fully aromatic species dominates over the corresponding tautomer. Indeed, no tautomerization product is found for either 1 c or 1 d upon heating or in the presence of catalytic amounts of acid. On the other hand, an unexpected dimer (3 c) is formed from 1 c. A plausible mechanism for this new dimerization process of the 6-methyl-substituted pentacene derivative 1 c is proposed, which involves first a bimolecular hydrogen atom transfer followed by an intramolecular [4+2] Diels-Alder cycloaddition. In the case of 6-butyl substitution, neither tautomerization nor dimerization is observed. Computations support the proposed 1 c dehydrodimerization pathway, explain why 1 d does not dimerize, and show the importance of the nature of the group at C-13 in controlling the relative stability of 6-alkyl-substituted pentacene tautomers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vitreous Substitutes: The Present and the Future

PubMed Central

Caprani, Simona Maria; Airaghi, Giulia; Bartalena, Luigi; Testa, Francesco; Mariotti, Cesare; Porta, Giovanni; Simonelli, Francesca

2014-01-01

Vitreoretinal surgery has advanced in numerous directions during recent years. The removal of the vitreous body is one of the main characteristics of this surgical procedure. Several molecules have been tested in the past to fill the vitreous cavity and to mimic its functions. We here review the currently available vitreous substitutes, focusing on their molecular properties and functions, together with their adverse effects. Afterwards we describe the characteristics of the ideal vitreous substitute. The challenges facing every ophthalmology researcher are to reach a long-term intraocular permanence of vitreous substitute with total inertness of the molecule injected and the control of inflammatory reactions. We report new polymers with gelification characteristics and smart hydrogels representing the future of vitreoretinal surgery. Finally, we describe the current studies on vitreous regeneration and cell cultures to create new intraocular gels with optimal biocompatibility and rheological properties. PMID:24877085

Slow but not low: genomic comparisons reveal slower evolutionary rate and higher dN/dS in conifers compared to angiosperms

PubMed Central

2012-01-01

Background Comparative genomics can inform us about the processes of mutation and selection across diverse taxa. Among seed plants, gymnosperms have been lacking in genomic comparisons. Recent EST and full-length cDNA collections for two conifers, Sitka spruce (Picea sitchensis) and loblolly pine (Pinus taeda), together with full genome sequences for two angiosperms, Arabidopsis thaliana and poplar (Populus trichocarpa), offer an opportunity to infer the evolutionary processes underlying thousands of orthologous protein-coding genes in gymnosperms compared with an angiosperm orthologue set. Results Based upon pairwise comparisons of 3,723 spruce and pine orthologues, we found an average synonymous genetic distance (dS) of 0.191, and an average dN/dS ratio of 0.314. Using a fossil-established divergence time of 140 million years between spruce and pine, we extrapolated a nucleotide substitution rate of 0.68 × 10-9 synonymous substitutions per site per year. When compared to angiosperms, this indicates a dramatically slower rate of nucleotide substitution rates in conifers: on average 15-fold. Coincidentally, we found a three-fold higher dN/dS for the spruce-pine lineage compared to the poplar-Arabidopsis lineage. This joint occurrence of a slower evolutionary rate in conifers with higher dN/dS, and possibly positive selection, showcases the uniqueness of conifer genome evolution. Conclusions Our results are in line with documented reduced nucleotide diversity, conservative genome evolution and low rates of diversification in conifers on the one hand and numerous examples of local adaptation in conifers on the other hand. We propose that reduced levels of nucleotide mutation in large and long-lived conifer trees, coupled with large effective population size, were the main factors leading to slow substitution rates but retention of beneficial mutations. PMID:22264329

Equivalent-Continuum Modeling of Nano-Structured Materials

NASA Technical Reports Server (NTRS)

Odegard, Gregory M.; Gates, Thomas S.; Nicholson, Lee M.; Wise, Kristopher E.

2001-01-01

A method has been developed for modeling structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with an equivalent-continuum model. It has been shown that this substitution may be accomplished by equating the vibrational potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As an important example with direct application to the development and characterization of single-walled carbon nanotubes, the model has been applied to determine the effective continuum geometry of a graphene sheet. A representative volume element of the equivalent-continuum model has been developed with an effective thickness. This effective thickness has been shown to be similar to, but slightly smaller than, the interatomic spacing of graphite.

Substitution and addition reactions of •OH with p-substituted-phenols

NASA Astrophysics Data System (ADS)

Albarrán, Guadalupe; Galicia-Jiménez, Eduardo; Mendoza, Edith; Schuler, Robert H.

2017-04-01

The directing effect of a hydroxyl group on the substitution and addition reactions of •OH to the substituted and free positions in aromatic rings of p-substituted-phenols were studied in aqueous solutions containing either K3Fe(CN)6 as an oxidant of the substituted hydroxycyclohexadienyl radical initially formed or using ascorbic acid. The results showed that the attack of the •OH to the substituted position (ipso position) was followed by elimination of the substituent producing hydroquinone. The addition reaction of the •OH to the free position on the ring produced 4-substituent-catechol and 4-substituent-resorcinol derivatives. Identification and quantification of the radiolytic products were carried out using high performance liquid chromatography. The results of the yields are given for the p-halogen-phenols (p-X-Ph) p-F-Ph, p-Cl-Ph, p-Br-Ph and p-I-Ph. Other compounds, p-nitro-Ph, p-OH-benzoic acid, p-OH-benzonitrile, p-OH-benzaldehyde, p-OH-anisole and p-OH-benzyl alcohol (represented as p-Z-Ph), were only studied using K3Fe(CN)6 as the oxidant. The results show that the p-X-Ph are attacked by the •OH at the ipso position to the halogen in the proportion 1:0.53:0.46:0.11 for F>Cl>Br>I. The •OH attacked at the ipso position to the p-Z-Phs through a substitution reaction, which depended on the substituent group. Thus, the strongly deactivating groups produced less hydroquinone, indicating less substitution reaction than the strongly activating groups.

NEGF-DFT characterization of diarylethene photoswitches: Impact of substituents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Dyck, Colin; Geskin, Victor; Cornil, Jérôme

2015-01-22

In this presentation we report a theoretical study on the performance of diarylethene photoswitches. We start with a comparison between the electronic structures of different substituted diarylethene cores. Using a NEGF-DFT formalism we compute self-consistently transmission and IV curves with a focus on the impact of the substituents usually introduced for various synthetic and functional reasons. We find that the conductance properties of the diarylethene photoswitches are rather insensitive to these substitutions in the core. In the interpretation of our results, we make a connection between transmission spectra and molecular electronic properties.

Development of a wheat-Aegilops searsii substitution line with positively affecting Chinese steamed bread quality.

PubMed

Du, Xuye; Ma, Xin; Min, Jingzhi; Zhang, Xiaocun; Jia, Zhenzhen

2018-03-01

A wheat- Aegilops searsii substitution line GL1402, in which chromosome 1B was substituted with 1S s from Ae. searsii , was developed and detected using SDS-PAGE and GISH. The SDS-PAGE analysis showed that the HMW-GS encoded by the Glu-B1 loci of Chinese Spring was replaced by the HMW-GS encoded by the Glu-1S s loci of Ae. searsii . Glutenin macropolymer (GMP) investigation showed that GL1402 had a much higher GMP content than Chinese Spring did. A dough quality comparison of GL1402 and Chinese Spring indicated that GL1402 showed a significantly higher protein content and middle peak time (MPT), and a smaller right peak slope (RPS). Quality tests of Chinese steamed bread (CSB) showed that the GL1402 also produced good steamed bread quality. These results suggested that the substitution line is a valuable breeding material for improving the wheat processing quality.

Comparison of Porcine and Bovine Collagen Dural Substitutes in Posterior Fossa Decompression for Chiari I Malformation in Adults.

PubMed

Lee, Christine K; Mokhtari, Tara; Connolly, Ian D; Li, Gordon; Shuer, Lawrence M; Chang, Steven D; Steinberg, Gary K; Hayden Gephart, Melanie

2017-12-01

Posterior fossa decompression surgeries for Chiari malformations are susceptible to postoperative complications such as pseudomeningocele, external cerebrospinal fluid (CSF) leak, and meningitis. Various dural substitutes have been used to improve surgical outcomes. This study examined whether the collagen matrix dural substitute type correlated with the incidence of postoperative complications after posterior fossa decompression in adult patients with Chiari I malformations. A retrospective cohort study was conducted of 81 adult patients who underwent an elective decompressive surgery for treatment of symptomatic Chiari I malformations, with duraplasty involving a dural substitute derived from either bovine or porcine collagen matrix. Demographics and treatment characteristics were correlated with surgical outcomes. A total of 81 patients were included in the study. Compared with bovine dural substitute, porcine dural substitute was associated with a significantly higher risk of pseudomeningocele occurrence (odds ratio, 5.78; 95% confidence interval, 1.65-27.15; P = 0.01) and a higher overall complication rate (odds ratio, 3.70; 95% confidence interval, 1.23-12.71; P = 0.03) by univariate analysis. There was no significant difference in the rate of meningitis, repeat operations, or overall complication rate between the 2 dural substitutes. In addition, estimated blood loss was a significant risk factor for meningitis (P = 0.03). Multivariate analyses again showed that porcine dural substitute was associated with pseudomeningocele occurrence, although the association with higher overall complication rate did not reach significance. Dural substitutes generated from porcine collagen, compared with those from bovine collagen, were associated with a higher likelihood of pseudomeningocele development in adult patients undergoing Chiari I malformation decompression and duraplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

The tangled bank of amino acids

PubMed Central

Pollock, David D.

2016-01-01

Abstract The use of amino acid substitution matrices to model protein evolution has yielded important insights into both the evolutionary process and the properties of specific protein families. In order to make these models tractable, standard substitution matrices represent the average results of the evolutionary process rather than the underlying molecular biophysics and population genetics, treating proteins as a set of independently evolving sites rather than as an integrated biomolecular entity. With advances in computing and the increasing availability of sequence data, we now have an opportunity to move beyond current substitution matrices to more interpretable mechanistic models with greater fidelity to the evolutionary process of mutation and selection and the holistic nature of the selective constraints. As part of this endeavour, we consider how epistatic interactions induce spatial and temporal rate heterogeneity, and demonstrate how these generally ignored factors can reconcile standard substitution rate matrices and the underlying biology, allowing us to better understand the meaning of these substitution rates. Using computational simulations of protein evolution, we can demonstrate the importance of both spatial and temporal heterogeneity in modelling protein evolution. PMID:27028523

Antioxidant Capacity, Mineral Content and Sensory Properties of Gluten-Free Rice and Buckwheat Cookies

PubMed Central

Pestorić, Mladenka; Mišan, Aleksandra; Nedeljković, Nataša; Jambrec, Dubravka; Jovanov, Pavle; Banjac, Vojislav; Torbica, Aleksandra; Hadnađev, Miroslav; Mandić, Anamarija

2015-01-01

Summary Light buckwheat flour was used to substitute rice flour at the level of 10, 20 and 30% to produce gluten-free cookies. The substitution of gluten-free cookie formulation with light buckwheat flour contributed to the significantly higher mineral content, especially magnesium, potassium, iron and copper, in comparison with the control rice cookies (p<0.05). Gluten-free cookies made with rice flour and buckwheat flour exhibited significantly higher total phenolic and rutin content, scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH•), antioxidant activity and reducing power than the control cookies (p<0.05). Comparing all evaluated sensory properties, cookies containing 20% of light buckwheat flour had the most acceptable sensory properties. The obtained results of principal component analysis showed that the cookies with 20 and 30% buckwheat flour had better antioxidant and sensory properties in comparison with other two cookie samples. PMID:27904330

Structural and catalytic effects of an invariant purine substitution in the hammerhead ribozyme: implications for the mechanism of acid–base catalysis

PubMed Central

Schultz, Eric P.; Vasquez, Ernesto E.; Scott, William G.

2014-01-01

The hammerhead ribozyme catalyzes RNA cleavage via acid–base catalysis. Whether it does so by general acid–base catalysis, in which the RNA itself donates and abstracts protons in the transition state, as is typically assumed, or by specific acid–base catalysis, in which the RNA plays a structural role and proton transfer is mediated by active-site water molecules, is unknown. Previous biochemical and crystallographic experiments implicate an invariant purine in the active site, G12, as the general base. However, G12 may play a structural role consistent with specific base catalysis. To better understand the role of G12 in the mechanism of hammerhead catalysis, a 2.2 Å resolution crystal structure of a hammerhead ribozyme from Schistosoma mansoni with a purine substituted for G12 in the active site of the ribozyme was obtained. Comparison of this structure (PDB entry 3zd4), in which A12 is substituted for G, with three previously determined structures that now serve as important experimental controls, allows the identification of structural perturbations that are owing to the purine substitution itself. Kinetic measurements for G12 purine-substituted schistosomal hammerheads confirm a previously observed dependence of rate on the pK a of the substituted purine; in both cases inosine, which is similar to G in pK a and hydrogen-bonding properties, is unexpectedly inactive. Structural comparisons indicate that this may primarily be owing to the lack of the exocyclic 2-amino group in the G12A and G12I substitutions and its structural effect upon both the nucleotide base and phosphate of A9. The latter involves the perturbation of a previously identified and well characterized metal ion-binding site known to be catalytically important in both minimal and full-length hammerhead ribozyme sequences. The results permit it to be suggested that G12 plays an important role in stabilizing the active-site structure. This result, although not inconsistent with the potential role of G12 as a general base, indicates that an alternative hammerhead cleavage mechanism involving specific base catalysis may instead explain the observed rate dependence upon purine substitutions at G12. The crystallographic results, contrary to previous assumptions, therefore cannot be interpreted to favor the general base catalysis mecahnism over the specific base catalysis mechanism. Instead, both of these mutually exclusive mechanistic alternatives must be considered in light of the current structural and biochemical data. PMID:25195740

Structural and catalytic effects of an invariant purine substitution in the hammerhead ribozyme: implications for the mechanism of acid-base catalysis.

PubMed

Schultz, Eric P; Vasquez, Ernesto E; Scott, William G

2014-09-01

The hammerhead ribozyme catalyzes RNA cleavage via acid-base catalysis. Whether it does so by general acid-base catalysis, in which the RNA itself donates and abstracts protons in the transition state, as is typically assumed, or by specific acid-base catalysis, in which the RNA plays a structural role and proton transfer is mediated by active-site water molecules, is unknown. Previous biochemical and crystallographic experiments implicate an invariant purine in the active site, G12, as the general base. However, G12 may play a structural role consistent with specific base catalysis. To better understand the role of G12 in the mechanism of hammerhead catalysis, a 2.2 Å resolution crystal structure of a hammerhead ribozyme from Schistosoma mansoni with a purine substituted for G12 in the active site of the ribozyme was obtained. Comparison of this structure (PDB entry 3zd4), in which A12 is substituted for G, with three previously determined structures that now serve as important experimental controls, allows the identification of structural perturbations that are owing to the purine substitution itself. Kinetic measurements for G12 purine-substituted schistosomal hammerheads confirm a previously observed dependence of rate on the pK(a) of the substituted purine; in both cases inosine, which is similar to G in pK(a) and hydrogen-bonding properties, is unexpectedly inactive. Structural comparisons indicate that this may primarily be owing to the lack of the exocyclic 2-amino group in the G12A and G12I substitutions and its structural effect upon both the nucleotide base and phosphate of A9. The latter involves the perturbation of a previously identified and well characterized metal ion-binding site known to be catalytically important in both minimal and full-length hammerhead ribozyme sequences. The results permit it to be suggested that G12 plays an important role in stabilizing the active-site structure. This result, although not inconsistent with the potential role of G12 as a general base, indicates that an alternative hammerhead cleavage mechanism involving specific base catalysis may instead explain the observed rate dependence upon purine substitutions at G12. The crystallographic results, contrary to previous assumptions, therefore cannot be interpreted to favor the general base catalysis mecahnism over the specific base catalysis mechanism. Instead, both of these mutually exclusive mechanistic alternatives must be considered in light of the current structural and biochemical data.

Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi{sub 0.98}B{sub 0.02}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Hui, E-mail: huisun3@iflytek.com; Lu, Xu; Morelli, Donald T.

Boron-added CoSi, CoSi{sub 0.98}B{sub 0.02}, possesses a very high thermoelectric power factor of 60 μW cm{sup −1} K{sup −2} at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms is intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi{sub 0.98}B{sub 0.02} has been studied. Here, we present a study of the substitutionmore » of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands, while Ge substitution only shifts the Fermi level upward into the conduction band. Our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.« less

Variation analysis and gene annotation of eight MHC haplotypes: The MHC Haplotype Project

PubMed Central

Horton, Roger; Gibson, Richard; Coggill, Penny; Miretti, Marcos; Allcock, Richard J.; Almeida, Jeff; Forbes, Simon; Gilbert, James G. R.; Halls, Karen; Harrow, Jennifer L.; Hart, Elizabeth; Howe, Kevin; Jackson, David K.; Palmer, Sophie; Roberts, Anne N.; Sims, Sarah; Stewart, C. Andrew; Traherne, James A.; Trevanion, Steve; Wilming, Laurens; Rogers, Jane; de Jong, Pieter J.; Elliott, John F.; Sawcer, Stephen; Todd, John A.; Trowsdale, John

2008-01-01

The human major histocompatibility complex (MHC) is contained within about 4 Mb on the short arm of chromosome 6 and is recognised as the most variable region in the human genome. The primary aim of the MHC Haplotype Project was to provide a comprehensively annotated reference sequence of a single, human leukocyte antigen-homozygous MHC haplotype and to use it as a basis against which variations could be assessed from seven other similarly homozygous cell lines, representative of the most common MHC haplotypes in the European population. Comparison of the haplotype sequences, including four haplotypes not previously analysed, resulted in the identification of >44,000 variations, both substitutions and indels (insertions and deletions), which have been submitted to the dbSNP database. The gene annotation uncovered haplotype-specific differences and confirmed the presence of more than 300 loci, including over 160 protein-coding genes. Combined analysis of the variation and annotation datasets revealed 122 gene loci with coding substitutions of which 97 were non-synonymous. The haplotype (A3-B7-DR15; PGF cell line) designated as the new MHC reference sequence, has been incorporated into the human genome assembly (NCBI35 and subsequent builds), and constitutes the largest single-haplotype sequence of the human genome to date. The extensive variation and annotation data derived from the analysis of seven further haplotypes have been made publicly available and provide a framework and resource for future association studies of all MHC-associated diseases and transplant medicine. PMID:18193213

Active Cytokinins

PubMed Central

Mornet, René; Theiler, Jane B.; Leonard, Nelson J.; Schmitz, Ruth Y.; Moore, F. Hardy; Skoog, Folke

1979-01-01

Four series of azidopurines have been synthesized and tested for cytokinin activity in the tobacco callus bioassay: 2- and 8-azido-N6-benzyladenines, -N6-(Δ2-isopentenyl)adenines, and -zeatins, and N6-(2- and 4-azidobenzyl)adenines. The compounds having 2-azido substitution on the adenine ring are as active as the corresponding parent compounds, while those with 8-azido substitution are about 10 or more times as active. The 8-azidozeatin, which is the most active cytokinin observed, exhibited higher than minimal detectable activity at 1.2 × 10−5 micromolar, the lowest concentration tested. The shape of the growth curve indicates that even a concentration as low as 5 × 10−6 micromolar would probably be effective. By comparison, the lowest active concentration ever reported for zeatin has been 5 × 10−5 micromolar, representing a sensitivity rarely attained. All of the azido compounds have been submitted to photolysis in aqueous ethanol, and the photoproducts have been detected and identified by low and high resolution mass spectrometry. They are rationalized as products of abstraction and insertion reactions of the intermediate nitrenes. The potential of the major released products as cytokinins was also assessed by bioassay. 2-Azido-N6-(Δ2-isopentenyl)adenine competed with [14C]kinetin for the cytokinin-binding protein isolated from wheat germ. When the azido compound was photolysed in the presence of this protein, its attachment effectively blocked the binding of [14C]kinetin. PMID:16661017

Structure and Differentiated Electrical Characteristics of M1/2La1/2Cu3Ti4O12 (M = Li, Na, K) Ceramics Prepared by Sol-Gel Method

NASA Astrophysics Data System (ADS)

Liu, Zhanqing; Yang, Zupei

2017-10-01

New M1/2La1/2Cu3Ti4O12 (M = Li, Na, K) ceramics based on partial substitution of Li+, Na+, and K+ for La3+ in La2/3Cu3Ti4O12 (LCTO) have been prepared by a sol-gel method, and the effects of Li+, Na+, and K+ on the microstructure and electrical properties investigated in detail, revealing different results depending on the substituent. The cell parameter increased with increasing radius of the substituent ion (Li+, Na+, K+). Li1/2La1/2Cu3Ti4O12 (LLCTO) ceramic showed better frequency and temperature stability, but the dielectric constant decreased and the third abnormal dielectric peak disappeared from the dielectric temperature spectrum. Na1/2La1/2Cu3Ti4O12 (NLCTO) ceramic exhibited higher dielectric constant and better frequency and temperature stability, and displayed the second dielectric relaxation in electric modulus plots. The performance of K1/2La1/2Cu3Ti4O12 (KLCTO) ceramic was deteriorated. These different microstructures and electrical properties may be due to the effect of different defect structures generated in the ceramic as well as grain size. This work represents the first analysis and comparison of these remarkable differences in the electrical behavior of ceramics obtained by partial substitution of Li+, Na+, and K+ for La3+ in LCTO.

Efficacy of Bone Source™ and Cementek™ in comparison with Endobon™ in critical size metaphyseal defects, using a minipig model.

PubMed

Spies, Christian K G; Schnürer, Stefan; Gotterbarm, Tobias; Breusch, Steffen J

2010-01-01

To examine and compare biocompatibility, osteocompatibility, rate of resorption, and remodelling dynamics of 2 calcium phosphate cements in comparison with a well-established hydroxyapatite ceramic. In a randomised fashion, Bone Source™, Cementek™, and Endobon™ were implanted bilaterally into the proximal metaphyseal tibiae of 35 Göttinger minipigs in a direct right vs. left intra-individual comparison. Fluorescent labelling was used. Histological and morphometric evaluations were carried out at 6, 12, and 52 weeks. All bone substitutes showed good biocompatibility, bioactivity, and osteoconductivity. Endobon™ was not degraded over the follow-up period. Cementek™ was degraded constantly and significantly over the time intervals, whereas Bone Source™ was degraded mainly from the 6 week to 12 week interval. After 52 weeks, a significant difference of residual material within the defect zone was detected between all substitutes, with the highest resorption rate for Cementek™. Bone Source™ was least degraded. Defects filled with Endobon™ were characterised by a significantly continuous bony ingrowth over the time intervals. Bone formation within the defects filled with Cementek™ and Bone Source™ showed significant peaks 12 weeks after implantation. After 52 weeks, a significant difference in the amount of new bone within the defect area was detected, with the highest levels for Endobon™, followed by Cementek™. After 1 year a restitution ad integrum could not be observed in any treatment group. The ceramic Endobon™ showed the expected response histologically. Based on its porosity it excelled in osteoconductivity. Concerning the calcium phosphate cements, a thorough osseous incorporation seemed to inhibit further degradation of both bone substitute materials.

The Local Geometry of Multiattribute Tradeoff Preferences

PubMed Central

McGeachie, Michael; Doyle, Jon

2011-01-01

Existing representations for multiattribute ceteris paribus preference statements have provided useful treatments and clear semantics for qualitative comparisons, but have not provided similarly clear representations or semantics for comparisons involving quantitative tradeoffs. We use directional derivatives and other concepts from elementary differential geometry to interpret conditional multiattribute ceteris paribus preference comparisons that state bounds on quantitative tradeoff ratios. This semantics extends the familiar economic notion of marginal rate of substitution to multiple continuous or discrete attributes. The same geometric concepts also provide means for interpreting statements about the relative importance of different attributes. PMID:21528018

Synthesis and solid-state characterisation of 4-substituted methylidene oxindoles

PubMed Central

2013-01-01

Background 4-substituted methylidene oxindoles are pharmacologically important. Detailed analysis and comparison of all the interactions present in crystal structures is necessary to understand how these structures arise. The XPac procedure allows comparison of complete crystal structures of related families of compounds to identify assemblies that are mainly the result of close-packing as well as networks of directed interactions. Results Five 4-substituted methylidene oxindoles have been synthesized by the Knoevenagel condensation of oxindole with para-substituted aromatic aldehydes and were characterized in the solid state by x-ray crystallography. Hence, the structures of (3E)-3-(4-Bromobenzylidene)-1,3-dihydro-2H-indol-2-one, 3a, (3E)-3-(4-Chlorobenzylidene)-1,3-dihydro-2H-indol-2-one, 3b, (3E)-3-(4-Methoxybenzylidene)-1,3-dihydro-2H-indol-2-one, 3c, (3E)-3-(4-Methylbenzylidene)-1,3-dihydro-2H-indol-2-one, 3d and (3E)-3-(4-Nitrobenzylidene)-1,3-dihydro-2H-indol-2-one, 3e, were elucidated using single crystal X-ray crystallography. Conclusions A hydrogen bonded dimer molecular assembly or supramolecular construct was identified in all the crystal structures examined along with a further four 1D supramolecular constructs which were common to at least two of the family of structures studied. The 1D supramolecular constructs indicate that once the obvious strong interaction is satisfied to form hydrogen bonded dimer it is the conventionally weaker interactions, such as steric bulk and edge-to-face interactions which compete to influence the final structure formation. PMID:24517531

Candida kantuleensis sp. nov., a d-xylose-fermenting yeast species isolated from peat in a tropical peat swamp forest.

PubMed

Nitiyon, Sukanya; Khunnamwong, Pannida; Lertwattanasakul, Noppon; Limtong, Savitree

2018-05-24

Three strains (DMKU-XE11 T , DMKU-XE15 and DMKU-XE20) representing a single novel anamorphic and d-xylose-fermenting yeast species were obtained from three peat samples collected from Khan Thulee peat swamp forest in Surat Thani province, Thailand. The strains differed from each other by one to two nucleotide substitutions in the sequences of the D1/D2 region of the large subunit (LSU) rRNA gene and zero to one nucleotide substitution in the internal transcribed spacer (ITS) region. Phylogenetic analysis based on the combined sequences of the ITS and the D1/D2 regions showed that the three strains represented a single Candida species that was distinct from the other related species in the Lodderomyces/Candida albicans clade. The three strains form a subclade with the other Candida species including Candida sanyaensis, Candida tropicalis and Candida sojae. C. sanyaensis was the most closely related species, with 2.1-2.4 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 3.8-4.0 % nucleotide substitutions in the ITS region. The three strains (DMKU-XE11 T , DMKU-XE15 and DMKU-XE20) were assigned as a single novel species, which was named Candida kantuleensis sp. nov. The type strain is DMKU-XE11 T (=CBS 15219 T =TBRC 7764 T ). The MycoBank number for C. kantuleensis sp. nov. is MB 824179.

Density functional theory study of hydrogen atom abstraction from a series of para-substituted phenols: why is the Hammett σ(p)+ constant able to represent radical reaction rates?

PubMed

Yoshida, Tatsusada; Hirozumi, Koji; Harada, Masataka; Hitaoka, Seiji; Chuman, Hiroshi

2011-06-03

The rate of hydrogen atom abstraction from phenolic compounds by a radical is known to be often linear with the Hammett substitution constant σ(+), defined using the S(N)1 solvolysis rates of substituted cumyl chlorides. Nevertheless, a physicochemical reason for the above "empirical fact" has not been fully revealed. The transition states of complexes between the 2,2-diphenyl-1-picrylhydrazyl radical (dpph·) and a series of para-substituted phenols were determined by DFT (Density Functional Theory) calculations, and then the activation energy as well as the homolytic bond dissociation energy of the O-H bond and charge distribution in the transition state were calculated. The heterolytic bond dissociation energy of the C-Cl bond and charge distribution in the corresponding para-substituted cumyl chlorides were calculated in parallel. Excellent correlations among σ(+), charge distribution, and activation and bond dissociation energies revealed quantitatively that there is a strong similarity between the two reactions, showing that the electron-deficiency of the π-electron system conjugated with a substituent plays a crucial role in determining rates of the two reactions. The results provide a new insight into and physicochemical understanding of σ(+) in the hydrogen abstraction from substituted phenols by a radical.

Sensitivity-Based VOC Reactivity Calculation

EPA Science Inventory

Volatile Organic Compound (VOC) reactivity scales are used to compare the ozone-forming potentials of various compounds. The comparison allows for substitution of compounds to lessen formation of ozone from paints, solvents, and other products. Current reactivity scales for VOC c...

N6-Trimethyl-lysine metabolism. Structural identification of the metabolite 3-hydroxy-N6-trimethyl-lysine

PubMed Central

Novak, Raymond F.; Swift, Terrence J.; Hoppel, Charles L.

1980-01-01

1H and 13C nuclear-magnetic-resonance spectroscopy and functional-group analysis were used to determine the molecular structure of an isolated metabolite (IIb) of trimethyl-lysine as 3-hydroxy-N6-trimethyl-lysine, an important intermediate in the conversion of trimethyl-lysine into trimethylammoniobutyrate and carnitine [Hoppel, Cox & Novak (1980) Biochem. J. 188, 509–519]. Functional-group analysis revealed the presence of a primary amine and reaction of metabolite (IIb) with periodate yielded 4-N-trimethylammoniobutyrate as a product, showing 2,3-substitution on the molecule and suggesting that the 3-substitution on the molecule may be an alcohol ([unk]CH–OH), amine ([unk]CH[unk]–NH2) or carbonyl ([unk]C=O) functional group. 1H integration ratios, 1H and 13C chemical-shift data and 1H and 13C signal multiplicities from the sample (IIb) were used to complete the identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. For example, the proton multiplet at δ 4.2p.p.m. and doublet at δ 4.1p.p.m., positions representative of amine or alcohol substitution on methylene carbon atoms, integration ratios of 1:1:2:9:4 and a positive ninhydrin test suggest 3-hydroxy-N6-trimethyl-lysine as the molecular structure for metabolite (IIb). 13C chemical-shift data obtained from the sample (IIb) and compared with several model compounds (trimethylammoniohexanoate, trimethyl-lysine and 3-hydroxylysine) resulted in generation of the spectrum of the metabolite and allowed independent identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. The 1H spectrum of erythro- and threo-3-hydroxylysine are presented for comparison, and the 1H and 13C n.m.r. spectra of the erythro-isomer support this analysis. PMID:6772169

Histological comparison of autograft, allograft-DBM, xenograft, and synthetic grafts in a trabecular bone defect: an experimental study in rabbits.

PubMed

Athanasiou, Vasilis T; Papachristou, Dionysios J; Panagopoulos, Andreas; Saridis, Alkis; Scopa, Chrisoula D; Megas, Panagiotis

2010-01-01

Different types of bone-graft substitutes have been developed and are on the market worldwide to eliminate the drawbacks of autogenous grafting. This experimental animal study was undertaken to evaluate the different histological properties of various bone graft substitutes utilized in this hospital. Ninety New Zealand white rabbits were divided into six groups of 15 animals. Under general anesthesia, a 4.5 mm-wide hole was drilled into both the lateral femoral condyles of each rabbit, for a total of 180 condyles for analysis. The bone defects were filled with various grafts, these being 1) autograft, 2) DBM crunch allograft (Grafton), 3) bovine cancellous bone xenograft (Lubboc), 4) calcium phosphate hydroxyapatite substitute (Ceraform), 5) calcium sulfate substitute (Osteoset), and 6) no filling (control). The animals were sacrificed at 1, 3, and 6 months after implantation and tissue samples from the implanted areas were processed for histological evaluation. A histological grading scale was designed to determine the different histological parameters of bone healing. The highest histological grades were achieved with the use of cancellous bone autograft. Bovine xenograft (Lubboc) was the second best in the histological scale grading. The other substitutes (Grafton, Ceraform, Osteoset) had similar scores but were inferior to both allograft and xenograft. Bovine xenograft showed better biological response than the other bone graft substitutes; however, more clinical studies are necessary to determine its overall effectiveness.

An international comparison of legal frameworks for supported and substitute decision-making in mental health services.

PubMed

Davidson, Gavin; Brophy, Lisa; Campbell, Jim; Farrell, Susan J; Gooding, Piers; O'Brien, Ann-Marie

2016-01-01

There have been important recent developments in law, research, policy and practice relating to supporting people with decision-making impairments, in particular when a person's wishes and preferences are unclear or inaccessible. A driver in this respect is the United Nations Convention on the Rights of Persons with Disabilities (CRPD); the implications of the CRPD for policy and professional practices are currently debated. This article reviews and compares four legal frameworks for supported and substitute decision-making for people whose decision-making ability is impaired. In particular, it explores how these frameworks may apply to people with mental health problems. The four jurisdictions are: Ontario, Canada; Victoria, Australia; England and Wales, United Kingdom (UK); and Northern Ireland, UK. Comparisons and contrasts are made in the key areas of: the legal framework for supported and substitute decision-making; the criteria for intervention; the assessment process; the safeguards; and issues in practice. Thus Ontario has developed a relatively comprehensive, progressive and influential legal framework over the past 30 years but there remain concerns about the standardisation of decision-making ability assessments and how the laws work together. In Australia, the Victorian Law Reform Commission (2012) has recommended that the six different types of substitute decision-making under the three laws in that jurisdiction, need to be simplified, and integrated into a spectrum that includes supported decision-making. In England and Wales the Mental Capacity Act 2005 has a complex interface with mental health law. In Northern Ireland it is proposed to introduce a new Mental Capacity (Health, Welfare and Finance) Bill that will provide a unified structure for all substitute decision-making. The discussion will consider the key strengths and limitations of the approaches in each jurisdiction and identify possible ways that further progress can be made in law, policy and practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Triazine-Substituted and Acyl Hydrazones: Experiment and Computation Reveal a Stability Inversion at Low pH.

PubMed

Ji, Kun; Lee, Changsuk; Janesko, Benjamin G; Simanek, Eric E

2015-08-03

Condensation of a hydrazine-substituted s-triazine with an aldehyde or ketone yields an equivalent to the widely used, acid-labile acyl hydrazone. Hydrolysis of these hydrazones using a formaldehyde trap as monitored using HPLC reveals that triazine-substituted hydrazones are more labile than acetyl hydrazones at pH>5. The reactivity trends mirror that of the corresponding acetyl hydrazones, with hydrolysis rates increasing along the series (aromatic aldehyde

Sugar-rich sweet sorghum is distinctively affected by wall polymer features for biomass digestibility and ethanol fermentation in bagasse.

PubMed

Li, Meng; Feng, Shengqiu; Wu, Leiming; Li, Ying; Fan, Chunfen; Zhang, Rui; Zou, Weihua; Tu, Yuanyuan; Jing, Hai-Chun; Li, Shizhong; Peng, Liangcai

2014-09-01

Sweet sorghum has been regarded as a typical species for rich soluble-sugar and high lignocellulose residues, but their effects on biomass digestibility remain unclear. In this study, we examined total 63 representative sweet sorghum accessions that displayed a varied sugar level at stalk and diverse cell wall composition at bagasse. Correlative analysis showed that both soluble-sugar and dry-bagasse could not significantly affect lignocellulose saccharification under chemical pretreatments. Comparative analyses of five typical pairs of samples indicated that DP of crystalline cellulose and arabinose substitution degree of non-KOH-extractable hemicelluloses distinctively affected lignocellulose crystallinity for high biomass digestibility. By comparison, lignin could not alter lignocellulose crystallinity, but the KOH-extractable G-monomer predominately determined lignin negative impacts on biomass digestions, and the G-levels released from pretreatments significantly inhibited yeast fermentation. The results also suggested potential genetic approaches for enhancing soluble-sugar level and lignocellulose digestibility and reducing ethanol conversion inhibition in sweet sorghum. Copyright © 2014. Published by Elsevier Ltd.

Effects of (LiCe) co-substitution on the structural and electrical properties of CaBi2Nb2O9 ceramics

NASA Astrophysics Data System (ADS)

Tian, Xiao-Xia; Qu, Shao-Bo; Du, Hong-Liang; Li, Ye; Xu, Zhuo

2012-03-01

The piezoelectric, dielectric, and ferroelectric properties of the (LiCe) co-substituted calcium bismuth niobate (CaBi2Nb2O9, CBNO) are investigated. The piezoelectric properties of CBNO ceramics are significantly enhanced and the dielectric loss tan δ decreased. This makes poling using (LiCe) co-substitution easier. The ceramics (where □ represents A-site Ca2+ vacancies, possess a pure layered structure phase and no other phases can be found. The Ca0.88(LiCe)0.04□0.04Bi2Nb2O9 ceramics possess optimal piezoelectric properties, with piezoelectric coefficient (d33) and Curie temperature (TC) found to be 13.3 pC/N and 960 °C, respectively. The dielectric and piezoelectric properties of the (LiCe) co-substituted CBNO ceramics exhibit very stable temperature behaviours. This demonstrates that the CBNO ceramics are a promising candidate for ultrahigh temperature applications.

A comparative study of rhodopsin function in the great bowerbird (P tilonorhynchus nuchalis): Spectral tuning and light‐activated kinetics

PubMed Central

van Hazel, Ilke; Dungan, Sarah Z.; Hauser, Frances E.; Morrow, James M.; Endler, John A.

2016-01-01

Abstract Rhodopsin is the visual pigment responsible for initiating the phototransduction cascade in vertebrate rod photoreceptors. Although well‐characterized in a few model systems, comparative studies of rhodopsin function, particularly for nonmammalian vertebrates are comparatively lacking. Bowerbirds are rare among passerines in possessing a key substitution, D83N, at a site that is otherwise highly conserved among G protein‐coupled receptors. While this substitution is present in some dim‐light adapted vertebrates, often accompanying another unusual substitution, A292S, its functional relevance in birds is uncertain. To investigate functional effects associated with these two substitutions, we use the rhodopsin gene from the great bowerbird (Ptilonorhynchus nuchalis) as a background for site‐directed mutagenesis, in vitro expression and functional characterization. We also mutated these sites in two additional rhodopsins that do not naturally possess N83, chicken and bovine, for comparison. Both sites were found to contribute to spectral blue‐shifts, but had opposing effects on kinetic rates. Substitutions at site 83 were found to primarily affect the kinetics of light‐activated rhodopsin, while substitutions at site 292 had a larger impact on spectral tuning. The contribution of substitutions at site 83 to spectral tuning in particular depended on genetic background, but overall, the effects of substitutions were otherwise surprisingly additive, and the magnitudes of functional shifts were roughly similar across all three genetic backgrounds. By employing a comparative approach with multiple species, our study provides new insight into the joint impact of sites 83 and 292 on rhodopsin structure‐function as well as their evolutionary significance for dim‐light vision across vertebrates. PMID:26889650

A comparative study of rhodopsin function in the great bowerbird (Ptilonorhynchus nuchalis): Spectral tuning and light-activated kinetics.

PubMed

van Hazel, Ilke; Dungan, Sarah Z; Hauser, Frances E; Morrow, James M; Endler, John A; Chang, Belinda S W

2016-07-01

Rhodopsin is the visual pigment responsible for initiating the phototransduction cascade in vertebrate rod photoreceptors. Although well-characterized in a few model systems, comparative studies of rhodopsin function, particularly for nonmammalian vertebrates are comparatively lacking. Bowerbirds are rare among passerines in possessing a key substitution, D83N, at a site that is otherwise highly conserved among G protein-coupled receptors. While this substitution is present in some dim-light adapted vertebrates, often accompanying another unusual substitution, A292S, its functional relevance in birds is uncertain. To investigate functional effects associated with these two substitutions, we use the rhodopsin gene from the great bowerbird (Ptilonorhynchus nuchalis) as a background for site-directed mutagenesis, in vitro expression and functional characterization. We also mutated these sites in two additional rhodopsins that do not naturally possess N83, chicken and bovine, for comparison. Both sites were found to contribute to spectral blue-shifts, but had opposing effects on kinetic rates. Substitutions at site 83 were found to primarily affect the kinetics of light-activated rhodopsin, while substitutions at site 292 had a larger impact on spectral tuning. The contribution of substitutions at site 83 to spectral tuning in particular depended on genetic background, but overall, the effects of substitutions were otherwise surprisingly additive, and the magnitudes of functional shifts were roughly similar across all three genetic backgrounds. By employing a comparative approach with multiple species, our study provides new insight into the joint impact of sites 83 and 292 on rhodopsin structure-function as well as their evolutionary significance for dim-light vision across vertebrates. © 2016 The Protein Society.

Synthesis of Benzo[a]carbazoles and an Indolo[2,3-a]carbazole from 3-Aryltetramic Acids.

PubMed

Truax, Nathanyal J; Banales Mejia, Fernando; Kwansare, Deborah O; Lafferty, Megan M; Kean, Maeve H; Pelkey, Erin T

2016-08-05

A simple and flexible approach to 3-pyrrolin-2-one fused carbazoles is disclosed. The key step involves the BF3-mediated electrophilic substitution of indoles with N-alkyl-substituted 3-aryltetramic acids, which provides access to indole-substituted 3-pyrrolin-2-ones. Scholl-type oxidative cyclizations of these materials led to the formation of the corresponding 3-pyrrolin-2-one-fused benzo[a]carbazoles and indolo[2,3-a]carbazoles. This work represents the first synthesis of the benzo[a]pyrrolo[3,4-c]carbazol-3(8H)-one ring system, while the indolo[2,3-a]pyrrolo[3,4-c]carbazol-5-one ring system is found in a number of biologically active compounds including the protein kinase C (PKC) inhibitor, staurosporine.

Synthesis and pharmacological evaluation of N-substituted 2-(2-oxo-2H-chromen-4-yloxy)propanamide as cyclooxygenase inhibitors.

PubMed

Rambabu, D; Mulakayala, Naveen; Ismail; Kumar, K Ravi; Kumar, G Pavan; Mulakayala, Chaitanya; Kumar, Chitta Suresh; Kalle, Arunasree M; Rao, M V Basaveswara; Oruganti, Srinivas; Pal, Manojit

2012-11-01

A series of novel N-substituted 2-(2-oxo-2H-chromen-4-yloxy)propanamide derivatives were synthesized via converting the readily available 4-hydroxy coumarin to the corresponding ethyl 2-(2-oxo-2H-chromen-4-yloxy)propanoate followed by hydrolysis and then reacting with different substituted amines. The molecular structures of two representative compounds, that is, 3 and 5l were confirmed by single crystal X-ray diffraction study. All the compounds synthesized were evaluated for their cyclooxygenase (COX) inhibiting properties in vitro. The compound 5i showed balanced selectivity towards COX-2 over COX-1 inhibition and good docking scores when docked into the COX-2 protein. Copyright © 2012 Elsevier Ltd. All rights reserved.

Some implications of legalized substitution of prescribed pharmaceuticals.

PubMed

PARKER, J M

1962-12-22

In April 1962 the Alberta Government passed legislation permitting a pharmacist to substitute drugs on a written medical prescription unless the doctor indicated otherwise. The intent was stated to be in the interests of cheaper drugs for the people of Alberta. The legality of this legislature has been questioned in Federal courts of law. The legislation has been formally criticized by the official representatives of medicine and pharmacy on the ground that indiscriminate substitution of drugs is not in the public interest until such time as the quality of all available drugs is assured by governmental or other authoritative agency. It is not within the function of the Food and Drug Directorate to guarantee the quality of drugs sold in Canada, this assurance normally being provided in the trade mark adopted by the manufacturer.

Highly regioselective synthesis of N-3 organophosphorous derivatives of 3,4-dihydropyrimidin-2(1H)-ones and their calcium channel binding studies.

PubMed

Singh, Kamaljit; Singh, Kawaljit; Trappanese, Danielle M; Moreland, Robert S

2012-08-01

A series of novel N-3 substituted 3,4-dihydropyrimidin-2(1H)-ones derivatives bearing diaminophosphinyl, phosphonate and phosphorous containing heterocycles were obtained from 3,4-dihydropyrimidinones (DHPMs) in a regioselective manner through an efficient reaction protocol, tolerant to substitutional variation at the key diversity positions around the DHPM core. None of the representative compounds screened for calcium channel blocking activity was found to have significant activity compared to nifedipine. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Engineering bone tissue substitutes from human induced pluripotent stem cells.

PubMed

de Peppo, Giuseppe Maria; Marcos-Campos, Iván; Kahler, David John; Alsalman, Dana; Shang, Linshan; Vunjak-Novakovic, Gordana; Marolt, Darja

2013-05-21

Congenital defects, trauma, and disease can compromise the integrity and functionality of the skeletal system to the extent requiring implantation of bone grafts. Engineering of viable bone substitutes that can be personalized to meet specific clinical needs represents a promising therapeutic alternative. The aim of our study was to evaluate the utility of human-induced pluripotent stem cells (hiPSCs) for bone tissue engineering. We first induced three hiPSC lines with different tissue and reprogramming backgrounds into the mesenchymal lineages and used a combination of differentiation assays, surface antigen profiling, and global gene expression analysis to identify the lines exhibiting strong osteogenic differentiation potential. We then engineered functional bone substitutes by culturing hiPSC-derived mesenchymal progenitors on osteoconductive scaffolds in perfusion bioreactors and confirmed their phenotype stability in a subcutaneous implantation model for 12 wk. Molecular analysis confirmed that the maturation of bone substitutes in perfusion bioreactors results in global repression of cell proliferation and an increased expression of lineage-specific genes. These results pave the way for growing patient-specific bone substitutes for reconstructive treatments of the skeletal system and for constructing qualified experimental models of development and disease.

Object individuation is invariant to attentional diffusion: Changes in the size of the attended region do not interact with object-substitution masking.

PubMed

Goodhew, Stephanie C; Edwards, Mark

2016-12-01

When the human brain is confronted with complex and dynamic visual scenes, two pivotal processes are at play: visual attention (the process of selecting certain aspects of the scene for privileged processing) and object individuation (determining what information belongs to a continuing object over time versus what represents two or more distinct objects). Here we examined whether these processes are independent or whether they interact. Object-substitution masking (OSM) has been used as a tool to examine such questions, however, there is controversy surrounding whether OSM reflects object individuation versus substitution processes. The object-individuation account is agnostic regarding the role of attention, whereas object-substitution theory stipulates a pivotal role for attention. There have been attempts to investigate the role of attention in OSM, but they have been subject to alternative explanations. Here, therefore, we manipulated the size of the attended region, a pure and uncontaminated attentional manipulation, and examined the impact on OSM. Across three experiments, there was no interaction. This refutes the object-substitution theory of OSM. This, in turn, tell us that object-individuation is invariant the distribution of attention. Copyright © 2016 Elsevier B.V. All rights reserved.

The tangled bank of amino acids.

PubMed

Goldstein, Richard A; Pollock, David D

2016-07-01

The use of amino acid substitution matrices to model protein evolution has yielded important insights into both the evolutionary process and the properties of specific protein families. In order to make these models tractable, standard substitution matrices represent the average results of the evolutionary process rather than the underlying molecular biophysics and population genetics, treating proteins as a set of independently evolving sites rather than as an integrated biomolecular entity. With advances in computing and the increasing availability of sequence data, we now have an opportunity to move beyond current substitution matrices to more interpretable mechanistic models with greater fidelity to the evolutionary process of mutation and selection and the holistic nature of the selective constraints. As part of this endeavour, we consider how epistatic interactions induce spatial and temporal rate heterogeneity, and demonstrate how these generally ignored factors can reconcile standard substitution rate matrices and the underlying biology, allowing us to better understand the meaning of these substitution rates. Using computational simulations of protein evolution, we can demonstrate the importance of both spatial and temporal heterogeneity in modelling protein evolution. © 2016 The Authors Protein Science published by Wiley Periodicals, Inc. on behalf of The Protein Society.

Evolution and dispersal of St. Louis encephalitis virus in the Americas.

PubMed

Auguste, Albert J; Pybus, Oliver G; Carrington, Christine V F

2009-07-01

Using a Bayesian coalescent approach on a dataset of 73 envelope gene sequences we estimated substitution rates and dates of divergence for St. Louis encephalitis virus (SLEV) in the Americas. We found significant rate heterogeneity among lineages, such that "relaxed" molecular clock models were much better supported than a strict molecular clock. The mean substitution rate estimated for all SLEV was 4.1x10(-4)substitutions/site/year (95% HPD 2.5-5.7)-higher than previous estimates that relied on the less well-suited strict clock. Mean substitution rates for individual lineages varied from 3.7x10(-4) to 7.2x10(-4)substitutions/site/year. For the first time we also assessed the magnitude and direction of viral gene flow within the Americas. The overall direction of gene flow during the period represented by the phylogeny is from South to North, and the region between 15 degrees N and 30 degrees N latitude appears to be the major source of virus for the rest of North America, which is consistent with migratory birds returning to their northern breeding grounds having acquired infection while wintering in the region of the Gulf of Mexico.

Library Services and Construction Act Amendments of 1990. Conference Report (To Accompany H.R. 2742). House of Representatives, 101st Congress, 2nd Session.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC.

This conference report on the Library Services and Construction Act Amendments of 1990 includes the text of a substitute amendment agreed to by a committee of House of Representatives and Senate members. Amendments are presented for the following sections of the act: (1) Short Title; References; (2) Definitions; (3) Authorization of…

Expansion of inverted repeat does not decrease substitution rates in Pelargonium plastid genomes.

PubMed

Weng, Mao-Lun; Ruhlman, Tracey A; Jansen, Robert K

2017-04-01

For species with minor inverted repeat (IR) boundary changes in the plastid genome (plastome), nucleotide substitution rates were previously shown to be lower in the IR than the single copy regions (SC). However, the impact of large-scale IR expansion/contraction on plastid nucleotide substitution rates among closely related species remains unclear. We included plastomes from 22 Pelargonium species, including eight newly sequenced genomes, and used both pairwise and model-based comparisons to investigate the impact of the IR on sequence evolution in plastids. Ten types of plastome organization with different inversions or IR boundary changes were identified in Pelargonium. Inclusion in the IR was not sufficient to explain the variation of nucleotide substitution rates. Instead, the rate heterogeneity in Pelargonium plastomes was a mixture of locus-specific, lineage-specific and IR-dependent effects. Our study of Pelargonium plastomes that vary in IR length and gene content demonstrates that the evolutionary consequences of retaining these repeats are more complicated than previously suggested. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

The Effect of Terminal Substitution on the Helical Carbon Structure of Fluoro-Alkane Chains: a Pure Rotational Study of CH2OH-Cn-1F2n-1 (n = 4, 5,& 6)

NASA Astrophysics Data System (ADS)

Schwartz, Aaron Z. A.; Maturo, Mark P.; Obenchain, Daniel A.; Cooke, S. A.

2016-06-01

Continuing a series of studies to investigate the change in structure of hydrocarbons as the amount of fluorination is increased to varying degrees of substitution, we present a survey on the change in the helical nature of the fluorinated carbon backbone when a -CH2OH group is substituted for a terminal - CF3 group. Spectra for 1H,1H-heptafluorobutan-1-ol, 1H,1H-nonafluoropentan-1-ol, and 1H,1H-undecafluorohexan-1-ol were collected separately using a chirped-pulse FTMW spectrometer in the range of 7-13 GHz. Only one conformation was observed for each molecule. Additional measurements of the 1H,1H-heptafluorobutan-1-ol were completed using a Balle-Flygare cavity instrument. Assignments of the singly-substituted 13C isotopologues of the 1H,1H-heptafluorobutan-1-ol were also measured. A comparison of both ab initio and experimental structures will be presented.

Peripheral dysgraphia characterized by the co-occurrence of case substitutions in uppercase and letter substitutions in lowercase writing.

PubMed

Di Pietro, M; Schnider, A; Ptak, R

2011-10-01

Patients with peripheral dysgraphia due to impairment at the allographic level produce writing errors that affect the letter-form and are characterized by case confusions or the failure to write in a specific case or style (e.g., cursive). We studied the writing errors of a patient with pure peripheral dysgraphia who had entirely intact oral spelling, but produced many well-formed letter errors in written spelling. The comparison of uppercase print and lowercase cursive spelling revealed an uncommon pattern: while most uppercase errors were case substitutions (e.g., A - a), almost all lowercase errors were letter substitutions (e.g., n - r). Analyses of the relationship between target letters and substitution errors showed that errors were neither influenced by consonant-vowel status nor by letter frequency, though word length affected error frequency in lowercase writing. Moreover, while graphomotor similarity did not predict either the occurrence of uppercase or lowercase errors, visuospatial similarity was a significant predictor of lowercase errors. These results suggest that lowercase representations of cursive letter-forms are based on a description of entire letters (visuospatial features) and are not - as previously found for uppercase letters - specified in terms of strokes (graphomotor features). Copyright © 2010 Elsevier Srl. All rights reserved.

A comparative study between para-aminophenyl and ortho-aminophenyl benzothiazoles using NMR and DFT calculations.

PubMed

Pierens, G K; Venkatachalam, T K; Reutens, D

2014-08-01

Ortho-substituted and para-substituted aminophenyl benzothiazoles were synthesised and characterised using NMR spectroscopy. A comparison of the proton chemical shift values reveals significant differences in the observed chemical shift values for the NH protons indicating the presence of a hydrogen bond in all ortho-substituted compounds as compared to the para compounds. The presence of intramolecular hydrogen bond in the ortho amino substituted aminophenyl benzothiazole forces the molecule to be planar which may be an additional advantage in developing these compounds as Alzheimer's imaging agent because the binding to amyloid fibrils prefers planar compounds. The splitting pattern of the methylene proton next to the amino group also showed significant coupling to the amino proton consistent with the notion of the existence of slow exchange and hydrogen bond in the ortho-substituted compounds. This is further verified by density functional theory calculations which yielded a near planar low energy conformer for all the o-aminophenyl benzothiazoles and displayed a hydrogen bond from the amine proton to the nitrogen of the thiazole ring. A detailed analysis of the (1)H, (13)C and (15)N NMR chemical shifts and density functional theory calculated structures of the compounds are described. Copyright © 2014 John Wiley & Sons, Ltd.

Structure-activity relationships among substituted N-benzoyl derivatives of phenylalanine and its analogues in a microbial antitumor prescreen III: derivatives of p-fluoro-DL-phenylalanine.

PubMed

Otani, T T; Briley, M R

1985-01-01

Twelve substituted benzoyl derivatives of p-fluoro-DL-phenylalanine were prepared and tested for growth-inhibitory activity in a Lactobacillus casei system used as an antitumor prescreen. The 12 substituted benzoyl groups were the same as those attached to o-fluorophenylalanine and m-fluorophenylalanine studied earlier. The activity of these compounds was compared vertically among themselves and horizontally with the corresponding derivatives of o-fluorophenylalanine and of m-fluorophenylalanine. It was found that the derivatives of p-fluorophenylalanine, like those of o- and m-fluorophenylalanine, exhibited remarkable inhibition, all but one, i.e., the o-nitrobenzoyl derivative, showing inhibition that is considered to be positive in the prescreen. Particularly potent compounds in this group were the m-chlorobenzoyl-, p-chlorobenzoyl, m-nitrobenzoyl, and p-nitrobenzoyl derivatives. Comparison of the activity of the substituted benzoyl derivatives of all three structural isomers of fluorophenylalanine at equimolar concentrations showed that the derivatives of m-fluorophenylalanine were generally better inhibitors than those of o-fluoro- or p-fluorophenylalanine. Study of the ID50 values of the more active substituted benzoyl derivatives of the fluorophenylalanines showed that the most active of this group was m-chlorobenzoyl-p-fluoro-DL-phenylalanine.

Mechanistic study of manganese-substituted glycerol dehydrogenase using a kinetic and thermodynamic analysis.

PubMed

Fang, Baishan; Niu, Jin; Ren, Hong; Guo, Yingxia; Wang, Shizhen

2014-01-01

Mechanistic insights regarding the activity enhancement of dehydrogenase by metal ion substitution were investigated by a simple method using a kinetic and thermodynamic analysis. By profiling the binding energy of both the substrate and product, the metal ion's role in catalysis enhancement was revealed. Glycerol dehydrogenase (GDH) from Klebsiella pneumoniae sp., which demonstrated an improvement in activity by the substitution of a zinc ion with a manganese ion, was used as a model for the mechanistic study of metal ion substitution. A kinetic model based on an ordered Bi-Bi mechanism was proposed considering the noncompetitive product inhibition of dihydroxyacetone (DHA) and the competitive product inhibition of NADH. By obtaining preliminary kinetic parameters of substrate and product inhibition, the number of estimated parameters was reduced from 10 to 4 for a nonlinear regression-based kinetic parameter estimation. The simulated values of time-concentration curves fit the experimental values well, with an average relative error of 11.5% and 12.7% for Mn-GDH and GDH, respectively. A comparison of the binding energy of enzyme ternary complex for Mn-GDH and GDH derived from kinetic parameters indicated that metal ion substitution accelerated the release of dioxyacetone. The metal ion's role in catalysis enhancement was explicated.

Retail Clinic Visits For Low-Acuity Conditions Increase Utilization And Spending.

PubMed

Ashwood, J Scott; Gaynor, Martin; Setodji, Claude M; Reid, Rachel O; Weber, Ellerie; Mehrotra, Ateev

2016-03-01

Retail clinics have been viewed by policy makers and insurers as a mechanism to decrease health care spending, by substituting less expensive clinic visits for more expensive emergency department or physician office visits. However, retail clinics may actually increase spending if they drive new health care utilization. To assess whether retail clinic visits represent new utilization or a substitute for more expensive care, we used insurance claims data from Aetna for the period 2010-12 to track utilization and spending for eleven low-acuity conditions. We found that 58 percent of retail clinic visits for low-acuity conditions represented new utilization and that retail clinic use was associated with a modest increase in spending, of $14 per person per year. These findings do not support the idea that retail clinics decrease health care spending. Project HOPE—The People-to-People Health Foundation, Inc.

Comparison among methods of effective energy evaluation of corn silage for beef cattle.

PubMed

Wei, Ming; Chen, Zhiqiang; Wei, Shengjuan; Geng, Guangduo; Yan, Peishi

2018-06-01

This study was conducted to compare different methods on effective energy evaluation of corn silage for beef cattle. Twenty Wandong bulls (Chinese indigenous yellow cattle) with initial body weight of 281±15.6 kg, were assigned to 1 of 5 dietary treatments with 4 animals per treatment in a randomized complete block design. Five dietary treatments included group 1 with corn silage only diet, group 2 with corn silage-concentrate basal diet (BD) and 3 groups with 3 test diets, which were the BD partly substituted by corn silage at 10%, 30%, and 60%. The total collection digestion trial was conducted for 5 d for each block after a 10-d adaptation period, and then an open-circuit respiratory cage was used to measure the gas exchange of each animal in a consecutive 4-d period. The direct method-derived metabolizable energy and net energy of corn silage were 8.86 and 5.15 MJ/kg dry matter (DM), expressed as net energy requirement for maintenance and gain were 5.28 and 2.90 MJ/kg DM, respectively; the corresponding regression method-derived estimates were 8.96, 5.34, 5.37, and 2.98 MJ/kg DM, respectively. The direct method-derived estimates were not different (p>0.05) from those obtained using the regression method. Using substitution method, the nutrient apparent digestibility and effective energy values of corn silage varied with the increased corn silage substitution ratio (p<0.05). In addition, the corn silage estimates at the substitution ratio of 30% were similar to those estimated by direct and regression methods. In determining the energy value of corn silage using substitution method, there was a discrepancy between different substitution ratios, and the substitution ratio of 30% was more appropriate than 10% or 60% in the current study. The regression method based on multiple point substitution was more appropriate than single point substitution on energy evaluation of feedstuffs for beef cattle.

Genomic gigantism: DNA loss is slow in mountain grasshoppers.

PubMed

Bensasson, D; Petrov, D A; Zhang, D X; Hartl, D L; Hewitt, G M

2001-02-01

Several studies have shown DNA loss to be inversely correlated with genome size in animals. These studies include a comparison between Drosophila and the cricket, Laupala, but there has been no assessment of DNA loss in insects with very large genomes. Podisma pedestris, the brown mountain grasshopper, has a genome over 100 times as large as that of Drosophila and 10 times as large as that of Laupala. We used 58 paralogous nuclear pseudogenes of mitochondrial origin to study the characteristics of insertion, deletion, and point substitution in P. pedestris and Italopodisma. In animals, these pseudogenes are "dead on arrival"; they are abundant in many different eukaryotes, and their mitochondrial origin simplifies the identification of point substitutions accumulated in nuclear pseudogene lineages. There appears to be a mononucleotide repeat within the 643-bp pseudogene sequence studied that acts as a strong hot spot for insertions or deletions (indels). Because the data for other insect species did not contain such an unusual region, hot spots were excluded from species comparisons. The rate of DNA loss relative to point substitution appears to be considerably and significantly lower in the grasshoppers studied than in Drosophila or Laupala. This suggests that the inverse correlation between genome size and the rate of DNA loss can be extended to comparisons between insects with large or gigantic genomes (i.e., Laupala and Podisma). The low rate of DNA loss implies that in grasshoppers, the accumulation of point mutations is a more potent force for obscuring ancient pseudogenes than their loss through indel accumulation, whereas the reverse is true for Drosophila. The main factor contributing to the difference in the rates of DNA loss estimated for grasshoppers, crickets, and Drosophila appears to be deletion size. Large deletions are relatively rare in Podisma and Italopodisma.

Bisphenol S and F: A Systematic Review and Comparison of the Hormonal Activity of Bisphenol A Substitutes

PubMed Central

Bolden, Ashley L.

2015-01-01

Background Increasing concern over bisphenol A (BPA) as an endocrine-disrupting chemical and its possible effects on human health have prompted the removal of BPA from consumer products, often labeled “BPA-free.” Some of the chemical replacements, however, are also bisphenols and may have similar physiological effects in organisms. Bisphenol S (BPS) and bisphenol F (BPF) are two such BPA substitutes. Objectives This review was carried out to evaluate the physiological effects and endocrine activities of the BPA substitutes BPS and BPF. Further, we compared the hormonal potency of BPS and BPF to that of BPA. Methods We conducted a systematic review based on the Office of Health Assessment and Translation (OHAT) protocol. Results We identified the body of literature to date, consisting of 32 studies (25 in vitro only, and 7 in vivo). The majority of these studies examined the hormonal activities of BPS and BPF and found their potency to be in the same order of magnitude and of similar action as BPA (estrogenic, antiestrogenic, androgenic, and antiandrogenic) in vitro and in vivo. BPS also has potencies similar to that of estradiol in membrane-mediated pathways, which are important for cellular actions such as proliferation, differentiation, and death. BPS and BPF also showed other effects in vitro and in vivo, such as altered organ weights, reproductive end points, and enzyme expression. Conclusions Based on the current literature, BPS and BPF are as hormonally active as BPA, and they have endocrine-disrupting effects. Citation Rochester JR, Bolden AL. 2015. Bisphenol S and F: a systematic review and comparison of the hormonal activity of bisphenol A substitutes. Environ Health Perspect 123:643–650; http://dx.doi.org/10.1289/ehp.1408989 PMID:25775505

Cooling field and temperature dependent exchange bias in Gd substituted YFe0.5Cr0.5O3

NASA Astrophysics Data System (ADS)

Singh, Karan; Mukherjee, K.

2018-04-01

We report the results of our investigation of cooling field and temperature dependence of exchange bias on Gd substituted mixed metal oxide YFe0.5Cr0.5O3. A negative exchange bias is observed in the Gd-substituted compounds, in contrast to the positive exchange bias in parent compound, YFe0.5Cr0.5O3 [1]. With the increase in Gd concentration it is noted that the exchange bias decreases. It was noted that the paramagnetic contribution from Gd ions plays the leading role in comparison to the antiferromagnetic type correlations among spins as is observed for the parent compound. Due to magnetic rare earth ion, additional exchange interaction of the form Gd-O-Fe/Cr dominates the magnetic interaction arising due to the transition metal ions, resulting in the reduction in exchange bias value.

Effect of conformational mobility and hydrogen-bonding interactions on the selectivity of some guanidinoaryl-substituted mechanism-based inhibitors of trypsin-like serine proteases.

PubMed

Rai, R; Katzenellenbogen, J A

1992-11-13

Previously, we have reported that some guanidino-substituted alpha- and beta-aryl enol lactones I and II behaved as selective, mechanism-based inhibitors of some trypsin-like proteases (Rai, R.; Katzenellenbogen, J.A. J. Med. Chem., submitted). In this study, we describe the synthesis and kinetic evaluation of some related, guanidino-substituted enol lactones having greater conformational mobility and affording additional hydrogen-bonding sites at the active site. The alpha-aryl-substituted lactones 1 and 2, which have greater conformational mobility in the guanidinoaryl linkage than I, selectively inhibited the trypsin-like enzymes, and they were relatively poor inactivators of alpha-chymotrypsin and human neutrophil elastase (HNE). The iodo enol lactone 2 permanently inactivated trypsin, urokinase, tissue plasminogen activator, and plasmin, showing exceptionally high specificity in its interaction with trypsin and urokinase. The selectivity pattern exhibited by the closely related, conformationally less mobile alpha-aryl-substituted iodo lactone Ib, which was previously shown to be a selective suicide substrate of urokinase and plasmin, provides an interesting comparison. The alpha-benzamido-substituted lactones 3 and 4, which afford an additional site for active-site hydrogen bonding, were found to be very potent alternate substrate inhibitors of trypsin and urokinase. In addition, the iodo lactone 4 permanently inactivated alpha-chymotrypsin. The importance of secondary interactions in increasing the specificities in the case of alpha-chymotrypsin is discussed.

Improving the assessment of prescribing: use of a 'substitution index'.

PubMed

Kunisawa, Susumu; Otsubo, Tetsuya; Lee, Jason; Imanaka, Yuichi

2013-07-01

To analyse the current and potential utilization of generic drugs in Japan, to examine the maximum possible cost savings from generic drug use and to develop a fairer measure to assess the level of generic drug substitution. We conducted a cross-sectional retrospective analysis of nine million dispensing records during January to March 2010 in Kyoto Prefecture. Maximum potential quantity-based shares were defined as the quantity of generic drugs used plus the quantity of branded drugs that could have been replaced by generic drugs divided by the quantity of all drugs dispensed. We developed a 'substitution index', defined as the proportion of generic drugs out of the total drugs substitutable with generic drugs (based on quantity rather than cost). Generic drugs had a quantity-based share of 17.9%, a cost-based share of 8.9% and a maximum potential quantity-based share of 50.1%, which is lower than the actual generic drug shares of some other countries. The maximum possible cost savings as a result of generic drug substitution was 16.5%. We also observed wide variations in maximum potential quantity-based shares between health care sectors and health care institutions. Simple comparisons based on quantity-based shares may misrepresent the actual generic drug use. A substitution index that takes into account the maximum potential quantity-based share of generic drugs as a fairer measure may promote more realistic goals and encourage generic drug usage.

A life cycle approach to the management of household food waste - A Swedish full-scale case study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernstad, A., E-mail: anna.bernstad@chemeng.lth.se; Cour Jansen, J. la

2011-08-15

Research Highlights: > The comparison of three different methods for management of household food waste show that anaerobic digestion provides greater environmental benefits in relation to global warming potential, acidification and ozone depilation compared to incineration and composting of food waste. Use of produced biogas as car fuel provides larger environmental benefits compared to a use of biogas for heat and power production. > The use of produced digestate from the anaerobic digestion as substitution for chemical fertilizer on farmland provides avoidance of environmental burdens in the same ratio as the substitution of fossil fuels with produced biogas. > Sensitivitymore » analyses show that results are highly sensitive to assumptions regarding the environmental burdens connected to heat and energy supposedly substituted by the waste treatment. - Abstract: Environmental impacts from incineration, decentralised composting and centralised anaerobic digestion of solid organic household waste are compared using the EASEWASTE LCA-tool. The comparison is based on a full scale case study in southern Sweden and used input-data related to aspects such as source-separation behaviour, transport distances, etc. are site-specific. Results show that biological treatment methods - both anaerobic and aerobic, result in net avoidance of GHG-emissions, but give a larger contribution both to nutrient enrichment and acidification when compared to incineration. Results are to a high degree dependent on energy substitution and emissions during biological processes. It was seen that if it is assumed that produced biogas substitute electricity based on Danish coal power, this is preferable before use of biogas as car fuel. Use of biogas for Danish electricity substitution was also determined to be more beneficial compared to incineration of organic household waste. This is a result mainly of the use of plastic bags in the incineration alternative (compared to paper bags in the anaerobic) and the use of biofertiliser (digestate) from anaerobic treatment as substitution of chemical fertilisers used in an incineration alternative. Net impact related to GWP from the management chain varies from a contribution of 2.6 kg CO{sub 2}-eq/household and year if incineration is utilised, to an avoidance of 5.6 kg CO{sub 2}-eq/household and year if choosing anaerobic digestion and using produced biogas as car fuel. Impacts are often dependent on processes allocated far from the control of local decision-makers, indicating the importance of a holistic approach and extended collaboration between agents in the waste management chain.« less

Equivalent-Continuum Modeling With Application to Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Odegard, Gregory M.; Gates, Thomas S.; Nicholson, Lee M.; Wise, Kristopher E.

2002-01-01

A method has been proposed for developing structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with equivalent-continuum models. It has been shown that this substitution may be accomplished by equating the vibrational potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As important examples with direct application to the development and characterization of single-walled carbon nanotubes and the design of nanotube-based devices, the modeling technique has been applied to determine the effective-continuum geometry and bending rigidity of a graphene sheet. A representative volume element of the chemical structure of graphene has been substituted with equivalent-truss and equivalent continuum models. As a result, an effective thickness of the continuum model has been determined. This effective thickness has been shown to be significantly larger than the interatomic spacing of graphite. The effective thickness has been shown to be significantly larger than the inter-planar spacing of graphite. The effective bending rigidity of the equivalent-continuum model of a graphene sheet was determined by equating the vibrational potential energy of the molecular model of a graphene sheet subjected to cylindrical bending with the strain energy of an equivalent continuum plate subjected to cylindrical bending.

Ultrafast excited-state dynamics of 2,5-dimethylpyrrole.

PubMed

Yang, Dongyuan; Min, Yanjun; Chen, Zhichao; He, Zhigang; Yuan, Kaijun; Dai, Dongxu; Yang, Xueming; Wu, Guorong

2018-04-17

The ultrafast excited-state dynamics of 2,5-dimethylpyrrole following excitation at wavelengths in the range of 265.7-216.7 nm is studied using the time-resolved photoelectron imaging method. It is found that excitation at longer wavelengths (265.7-250.2 nm) results in the population of the S1(1πσ*) state, which decays out of the photoionization window in about 90 fs. At shorter pump wavelengths (242.1-216.7 nm), the assignments are less clear-cut. We tentatively assign the initially photoexcited state(s) to the 1π3p Rydberg state(s) which has lifetimes of 159 ± 20, 125 ± 15, 102 ± 10 and 88 ± 10 fs for the pump wavelengths of 242.1, 238.1, 232.6 and 216.7 nm, respectively. Internal conversion to the S1(1πσ*) state represents at most a minor decay channel. The methyl substitution effects on the decay dynamics of the excited states of pyrrole are also discussed. Methyl substitution on the pyrrole ring seems to enhance the direct internal conversion from the 1π3p Rydberg state to the ground state, while methyl substitution on the N atom has less influence and the internal conversion to the S1(πσ*) state represents a main channel.

Inhibition of rat prostate tumor growth by an octapeptide analog of somatostatin.

PubMed

Murphy, W A; Lance, V A; Moreau, S; Moreau, J P; Coy, D H

1987-06-29

Analogs of a potent octapeptide analog of somatostatin (SRIF) H-(D)Phe-Cys-Tyr-(D)Trp-Lys-Val-Cys-Thr(NH2) were synthesized. Aromatic substitutions for Tyr resulted in little change in inhibitory potency on growth hormone (GH) secretion in the rat. Substitutions for Val or (D)Trp resulted in analogs with diminished activity. Substitution of (D)Nal for (D)Phe increased duration of GH inhibition. Final weights of subcutaneously implanted prostate tumors (R3327) were 41% lower in rats treated with an N-terminal 4-chloro-(D)phenylalanyl analog as compared to vehicle treated controls. The analog had no effect on testicular weight or final plasma testosterone levels. SRIF analogs may represent an alternative treatment for prostate cancer that would be free of the untoward reproductive effects of other treatments (e.g. LH-RH or castration).

Some Implications of Legalized Substitution of Prescribed Pharmaceuticals

PubMed Central

Parker, J. M.

1962-01-01

In April 1962 the Alberta Government passed legislation permitting a pharmacist to substitute drugs on a written medical prescription unless the doctor indicated otherwise. The intent was stated to be in the interests of cheaper drugs for the people of Alberta. The legality of this legislature has been questioned in Federal courts of law. The legislation has been formally criticized by the official representatives of medicine and pharmacy on the ground that indiscriminate substitution of drugs is not in the public interest until such time as the quality of all available drugs is assured by governmental or other authoritative agency. It is not within the function of the Food and Drug Directorate to guarantee the quality of drugs sold in Canada, this assurance normally being provided in the trade mark adopted by the manufacturer. PMID:13941488

Exploration of the effect of sequence variations located inside the binding pocket of HIV-1 and HIV-2 proteases.

PubMed

Triki, Dhoha; Billot, Telli; Visseaux, Benoit; Descamps, Diane; Flatters, Delphine; Camproux, Anne-Claude; Regad, Leslie

2018-04-10

HIV-2 protease (PR2) is naturally resistant to most FDA (Food and Drug Administration)-approved HIV-1 protease inhibitors (PIs), a major antiretroviral class. In this study, we compared the PR1 and PR2 binding pockets extracted from structures complexed with 12 ligands. The comparison of PR1 and PR2 pocket properties showed that bound PR2 pockets were more hydrophobic with more oxygen atoms and fewer nitrogen atoms than PR1 pockets. The structural comparison of PR1 and PR2 pockets highlighted structural changes induced by their sequence variations and that were consistent with these property changes. Specifically, substitutions at residues 31, 46, and 82 induced structural changes in their main-chain atoms that could affect PI binding in PR2. In addition, the modelling of PR1 mutant structures containing V32I and L76M substitutions revealed a cooperative mechanism leading to structural deformation of flap-residue 45 that could modify PR2 flexibility. Our results suggest that substitutions in the PR1 and PR2 pockets can modify PI binding and flap flexibility, which could underlie PR2 resistance against PIs. These results provide new insights concerning the structural changes induced by PR1 and PR2 pocket variation changes, improving the understanding of the atomic mechanism of PR2 resistance to PIs.

The High Teperature Influence on Geopolymer Fly Ash Mixture’s Compressisive Strength with Insudtrial Waste Material Substitution

NASA Astrophysics Data System (ADS)

Bayuaji, R.; Wibowo, B.; Subekti, S.; Santoso, S. E.; Hardiyanto, E.; Kaelani, Y.; Mallu, L. L.

2017-11-01

This research aimed to figure out the influence of fly ash mixture from the industrial waste at the temperatures of 150°C, 450°C, 750°C viewed from the strength and resistance of geopolymer paste. As a result, cement will be substituted by industrial waste like fly ash. This experimental research was conducted on the mix design of geopolymer concrete which was made by dimension with 2.5 cm in diameter and 5 cm in height from four mixture composition of fly ash and industrial waste i.e. 100% fly ash, 50% fly ash+50% bottom ash, 50% fly ash+50% sandblast, and 50% fly ash+50% carbide waste. Each mixture was tested in terms of porosity and compressive strength. In conclusion, in the mixture of 50% fly ash+50% Sandblast and 50% fly ash+50% bottom ash in 12 molars, 1.5 activator comparison can be used to substitute fly ash at high temperature. Meanwhile, the mixture of 50% fly ash+50% carbide waste in 8 molars, 0.5 activator comparison has very small strength remaining if it is compared to the mixture of fly ash and other industrial waste (Bottom ash and Sandblast). The performance of mixture paste of 50% fly ash+50% carbide waste was very vulnerable after being burnt. Consequently, it cannot be used as the main structure at high temperature.

Relationship between Al content and substitution mechanism of Al-bearing anhydrous bridgmanites

NASA Astrophysics Data System (ADS)

Noda, M.; Inoue, T.; Kakizawa, S.

2017-12-01

It is considered that two substitution mechanisms, Tschermak substitution and oxygen vacancy substitution, exist in MgSiO3 bridgmanite for the incorporation of Al in anhydrous condition. Kubo and Akaogi (2000) has conducted the phase equilibrium experiment in the system MgSiO3-Al2O3, and established the phase diagram up to 28 GPa. However the careful observation in the bridgmanite shows that the chemical compositions are slightly deviated from Tschermak substitution join. The same tendency can be also observed in the run products by Irifune et al. (1996). This result indicates that pure Tschermak substitution bridgmanite cannot be stable even in the MgSiO3-Al2O3 join experiment. However, the previous studies used powder samples as the starting materials, so the absorbed water may affect the results. Therefore, we tried to conduct the experiment in the join MgSiO3-Al2O3 in extremely anhydrous condition to clarify whether the pure Tschermak substitution bridgmanite can be stable or not. In addition, we also examined the stability of oxygen vacancy bridgmanite in the extremely anhydrous condition for the comparison. The high pressure synthesis experiments were conducted at 28 GPa and 1600-1700° for 1hour using a Kawai-type multi-anvil apparatus. Four different Al content samples were prepared as the starting materials along the ideal substitution line of Tschermak (Al=0.025, 0.05, 0.1, 0.15 mol) and oxygen-vacancy (Al=0.025, 0.05, 0.075, 0.1 mol) substitutions, respectively (when total cation of 2). The glass rods were used as the starting materials to eliminate the absorbed water on the sample surface. The chemical compositions of the synthesized bridgmanite could not be measured by EPMA because of small grain size less than submicron. Therefore the chemical compositions were estimated from the result of the XRD pattern by subtracting the amount of the other phases. The estimated chemical compositions of Tschermak substitution bridgmanites were consistent with the ideal compositions. On the other hand, oxygen-vacancy substitution bridgmanite was possible to be existed less than Al=0.25 mol on the basis of total cation of 2. These results show that both Tschermak and oxygen-vacancy substitution bridgmanites can exist in low Al content in anhydrous condition.

Application of ChemDraw NMR Tool: Correlation of Program-Generated 13C Chemical Shifts and pKa Values of para-Substituted Benzoic Acids

NASA Astrophysics Data System (ADS)

Wang, Hongyi

2005-09-01

An application of ChemDraw NMR Tool was demonstrated by correlation of program-generated 13 C NMR chemical shifts and p K a values of para-substituted benzoic acids. Experimental 13 C NMR chemical shifts were analyzed in the same way for comparison. The project can be used as an assignment at the end of the first-year organic chemistry course to review topics or explore new techniques: Hammett equation, acid base equilibrium theory, electronic nature of functional groups, inductive and resonance effects, structure reactivity relationship, NMR spectroscopy, literature search, database search, and ChemDraw software.

Enantiomeric Recognition of Organic Ammonium Salts by Chiral Dialkyl-, Dialkenyl-, and Tetramethyl-Substituted Pyridino-18-Crown-6 and Tetramethyl- Substituted Bis-Pyridino-18-Crown-6 Ligands: Comparison of Temperature-Dependent 1H NMR and Empirical Force Field Techniques

DTIC Science & Technology

1990-04-18

COVERED 14, DATE OF REPORT (Year. Month, Day) 15. PAGE COUNT Interim FROM _ _ TO April 18, 1990 16. SUPPLEMENTARY NOTATION 17 , COSATI CODES 18. SUBJECT...to epoxide 17 was carried out ,o by using the method of Koppenhoefer and Schurig.241-2 Our epoxides 17 where R was isopropyl, isobutyl, and Scheme i... 17 with diethylene glycol and a catalytic amount of sodium was carried out as reported for the preparation of the chiral dimethyl- tetraethylene glycol

Interactions between soil thermal and hydrological dynamics in the response of Alaska ecosystems to fire disturbance

USGS Publications Warehouse

Yi, Shuhua; McGuire, A. David; Harden, Jennifer; Kasischke, Eric; Manies, Kristen L.; Hinzman, Larry; Liljedahl, Anna K.; Randerson, J.; Liu, Heping; Romanovsky, Vladimir E.; Marchenko, Sergey S.; Kim, Yongwon

2009-01-01

Soil temperature and moisture are important factors that control many ecosystem processes. However, interactions between soil thermal and hydrological processes are not adequately understood in cold regions, where the frozen soil, fire disturbance, and soil drainage play important roles in controlling interactions among these processes. These interactions were investigated with a new ecosystem model framework, the dynamic organic soil version of the Terrestrial Ecosystem Model, that incorporates an efficient and stable numerical scheme for simulating soil thermal and hydrological dynamics within soil profiles that contain a live moss horizon, fibrous and amorphous organic horizons, and mineral soil horizons. The performance of the model was evaluated for a tundra burn site that had both preburn and postburn measurements, two black spruce fire chronosequences (representing space-for-time substitutions in well and intermediately drained conditions), and a poorly drained black spruce site. Although space-for-time substitutions present challenges in model-data comparison, the model demonstrates substantial ability in simulating the dynamics of evapotranspiration, soil temperature, active layer depth, soil moisture, and water table depth in response to both climate variability and fire disturbance. Several differences between model simulations and field measurements identified key challenges for evaluating/improving model performance that include (1) proper representation of discrepancies between air temperature and ground surface temperature; (2) minimization of precipitation biases in the driving data sets; (3) improvement of the measurement accuracy of soil moisture in surface organic horizons; and (4) proper specification of organic horizon depth/properties, and soil thermal conductivity.

The Usher Syndrome Type IIIB Histidyl-tRNA Synthetase Mutation Confers Temperature Sensitivity.

PubMed

Abbott, Jamie A; Guth, Ethan; Kim, Cindy; Regan, Cathy; Siu, Victoria M; Rupar, C Anthony; Demeler, Borries; Francklyn, Christopher S; Robey-Bond, Susan M

2017-07-18

Histidyl-tRNA synthetase (HARS) is a highly conserved translation factor that plays an essential role in protein synthesis. HARS has been implicated in the human syndromes Charcot-Marie-Tooth (CMT) Type 2W and Type IIIB Usher (USH3B). The USH3B mutation, which encodes a Y454S substitution in HARS, is inherited in an autosomal recessive fashion and associated with childhood deafness, blindness, and episodic hallucinations during acute illness. The biochemical basis of the pathophysiologies linked to USH3B is currently unknown. Here, we present a detailed functional comparison of wild-type (WT) and Y454S HARS enzymes. Kinetic parameters for enzymes and canonical substrates were determined using both steady state and rapid kinetics. Enzyme stability was examined using differential scanning fluorimetry. Finally, enzyme functionality in a primary cell culture was assessed. Our results demonstrate that the Y454S substitution leaves HARS amino acid activation, aminoacylation, and tRNA His binding functions largely intact compared with those of WT HARS, and the mutant enzyme dimerizes like the wild type does. Interestingly, during our investigation, it was revealed that the kinetics of amino acid activation differs from that of the previously characterized bacterial HisRS. Despite the similar kinetics, differential scanning fluorimetry revealed that Y454S is less thermally stable than WT HARS, and cells from Y454S patients grown at elevated temperatures demonstrate diminished levels of protein synthesis compared to those of WT cells. The thermal sensitivity associated with the Y454S mutation represents a biochemical basis for understanding USH3B.

Divergent strategy for the synthesis of alpha-aryl-substituted fosmidomycin analogues.

PubMed

Devreux, Vincent; Wiesner, Jochen; Jomaa, Hassan; Rozenski, Jef; Van der Eycken, Johan; Van Calenbergh, Serge

2007-05-11

Fosmidomycin is the first representative of a new class of antimalarial drugs acting through inhibition of 1-deoxy-D-xylulose 5-phosphate (DOXP) reductoisomerase (DXR), an essential enzyme in the non-mevalonate pathway for the synthesis of isoprenoids. This work describes a divergent strategy for the synthesis of a series of alpha-aryl-substituted fosmidomycin analogues, featuring a palladium-catalyzed Stille coupling as the key step. An alpha-(4-cyanophenyl)fosmidomycin analogue emerged as the most potent analogue in the present series. Its antimalarial activity clearly surpasses that of the reference compound fosmidomycin.

[The primary structure of a vaccine strain of tobacco mosaic virus V-69].

PubMed

Shiian, A N; Mil'shina, N V; Snegireva, P B; Pukhal'skiĭ, V A

1994-12-01

A random set of cDNA fragments were synthesized on genomic RNA of TMV vaccine strain V-69, using random primers and reverse transcriptase. Following synthesis of double-stranded cDNA, they were cloned into the pUC-19 plasmid; and 28 clones were sequenced (insert size 100-500 bp). High nucleotide sequence homology of V-69 (more than 95%) was shown only with tomato strain TMV-L [1]. Sequenced clones represent 54% of the genome (50% of the replicase gene, 98% of the transport protein gene, and 60% of the coat protein gene). In this genome region, 24 base substitutions were revealed, as compared to the wild-type TMV-L sequence. Six base substitutions resulted in changes in corresponding amino acid codons. No substitutions coincided with those discovered in the related TMV vaccine strain L11A [2], while two substitutions in the replicase gene were identical to those found in TMV strain Lta1 [3], which is capable of overcoming protection in tomatoes with the resistance gene Tm-1.

Can we cut out the meat of the dish? Constructing consumer-oriented pathways towards meat substitution.

PubMed

Schösler, Hanna; de Boer, Joop; Boersema, Jan J

2012-02-01

The shift towards a more sustainable diet necessitates less reliance on foods of animal origin. This study presents data from a representative survey of Dutch consumers on their practices related to meat, meat substitution and meat reduction. The practices reflected a cultural gradient of meat substitution options running from other products of animal origin and conventional meat free meals to real vegetarian meals. To investigate feasible substitution options, a variety of meals without meat were presented using photos, which were rated by the participants in terms of attractiveness and chances that they would prepare a similar meal at home. The results demonstrated the influence of meal formats, product familiarity, cooking skills, preferences for plant-based foods and motivational orientations towards food. In particular, a lack of familiarity and skill hampered the preparation of real vegetarian meals. Based on the findings we propose a diversified understanding of meat substitution and we specify four policy-relevant pathways for a transition towards a more plant-based diet, including an incremental change towards more health-conscious vegetarian meals, a pathway that utilizes the trend towards convenience, a pathway of reduced portion size, and practice-oriented change towards vegetarian meals. Copyright © 2011 Elsevier Ltd. All rights reserved.

A Dicobalt Complex with an Unsymmetrical Quinonoid Bridge Isolated in Three Units of Charge: A Combined Structural, (Spectro)electrochemical, Magnetic and Spectroscopic Study.

PubMed

van der Meer, Margarethe; Rechkemmer, Yvonne; Frank, Uta; Breitgoff, Frauke D; Hohloch, Stephan; Su, Cheng-Yong; Neugebauer, Petr; Marx, Raphael; Dörfel, María; van Slageren, Joris; Sarkar, Biprajit

2016-09-19

Quinonoid ligands are excellent bridges for generating redox-rich dinuclear assemblies. A large majority of these bridges are symmetrically substituted, with examples of unsymmetrically substituted quinonoid bridges being extremely rare. We present here a dicobalt complex in its various redox states with an unsymmetrically substituted quinonoid bridging ligand. Two homovalent forms and one mixed-valent form have been isolated and characterized by single crystal X-ray diffraction. The complex displays a large comproportionation constant for the mixed-valent state which is three orders of magnitude higher than that observed for the analogous complex with a symmetrically substituted bridge. Results from electrochemistry, UV/Vis/NIR spectroelectrochemistry, SQUID magnetometry, multi-frequency EPR spectroscopy and FIR spectroscopy are used to probe the electronic structures of these complexes. FIR provides direct evidence of exchange coupling. The results presented here display the advantages of using an unsymmetrically substituted bridge: site specific redox chemistry, high thermodynamic stabilization of the mixed-valent form, isolation and crystallization of various redox forms of the complex. This work represents an important step on the way to generating heterodinuclear complexes for use in cooperative catalysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sensory Substitution: The Spatial Updating of Auditory Scenes "Mimics" the Spatial Updating of Visual Scenes.

PubMed

Pasqualotto, Achille; Esenkaya, Tayfun

2016-01-01

Visual-to-auditory sensory substitution is used to convey visual information through audition, and it was initially created to compensate for blindness; it consists of software converting the visual images captured by a video-camera into the equivalent auditory images, or "soundscapes". Here, it was used by blindfolded sighted participants to learn the spatial position of simple shapes depicted in images arranged on the floor. Very few studies have used sensory substitution to investigate spatial representation, while it has been widely used to investigate object recognition. Additionally, with sensory substitution we could study the performance of participants actively exploring the environment through audition, rather than passively localizing sound sources. Blindfolded participants egocentrically learnt the position of six images by using sensory substitution and then a judgment of relative direction task (JRD) was used to determine how this scene was represented. This task consists of imagining being in a given location, oriented in a given direction, and pointing towards the required image. Before performing the JRD task, participants explored a map that provided allocentric information about the scene. Although spatial exploration was egocentric, surprisingly we found that performance in the JRD task was better for allocentric perspectives. This suggests that the egocentric representation of the scene was updated. This result is in line with previous studies using visual and somatosensory scenes, thus supporting the notion that different sensory modalities produce equivalent spatial representation(s). Moreover, our results have practical implications to improve training methods with sensory substitution devices (SSD).

Divergent synthesis and chemical reactivity of bicyclic lactone fragments of complex rearranged spongian diterpenes.

PubMed

Schnermann, Martin J; Beaudry, Christopher M; Genung, Nathan E; Canham, Stephen M; Untiedt, Nicholas L; Karanikolas, Breanne D W; Sütterlin, Christine; Overman, Larry E

2011-11-02

The synthesis and direct comparison of the chemical reactivity of the two highly oxidized bicyclic lactone fragments found in rearranged spongian diterpenes (8-substituted 6-acetoxy-2,7-dioxabicyclo[3.2.1]octan-3-one and 6-substituted 7-acetoxy-2,8-dioxabicyclo[3.3.0]octan-3-one) are reported. Details of the first synthesis of the 6-acetoxy-2,7-dioxabicyclo[3.2.1]octan-3-one ring system, including an examination of several possibilities for the key bridging cyclization reaction, are described. In addition, the first synthesis of 7-acetoxy-2,8-dioxabicyclo[3.3.0]octanones containing quaternary carbon substituents at C6 is disclosed. Aspects of the chemical reactivity and Golgi-modifying properties of these bicyclic lactone analogs of rearranged spongian diterpenes are also reported. Under both acidic and basic conditions, 8-substituted 2,7-dioxabicyclo[3.2.1]octanones are converted to 6-substituted-2,8-dioxabicyclo[3.3.0]octanones. Moreover, these dioxabicyclic lactones react with primary amines and lysine side chains of lysozyme to form substituted pyrroles, a conjugation that could be responsible for the unique biological properties of these compounds. These studies demonstrate that acetoxylation adjacent to the lactone carbonyl group, in either the bridged or fused series, is required to produce fragmented Golgi membranes in the pericentriolar region that is characteristic of macfarlandin E.

Hydrogen-assisted post-growth substitution of tellurium into molybdenum disulfide monolayers with tunable compositions

NASA Astrophysics Data System (ADS)

Yin, Guoli; Zhu, Dancheng; Lv, Danhui; Hashemi, Arsalan; Fei, Zhen; Lin, Fang; Krasheninnikov, Arkady V.; Zhang, Ze; Komsa, Hannu-Pekka; Jin, Chuanhong

2018-04-01

Herein we report the successful doping of tellurium (Te) into molybdenum disulfide (MoS2) monolayers to form MoS2x Te2(1-x) alloy with variable compositions via a hydrogen-assisted post-growth chemical vapor deposition process. It is confirmed that H2 plays an indispensable role in the Te substitution into as-grown MoS2 monolayers. Atomic-resolution transmission electron microscopy allows us to determine the lattice sites and the concentration of introduced Te atoms. At a relatively low concentration, tellurium is only substituted in the sulfur sublattice to form monolayer MoS2(1-x)Te2x alloy, while with increasing Te concentration (up to ˜27.6% achieved in this study), local regions with enriched tellurium, large structural distortions, and obvious sulfur deficiency are observed. Statistical analysis of the Te distribution indicates the random substitution. Density functional theory calculations are used to investigate the stability of the alloy structures and their electronic properties. Comparison with experimental results indicate that the samples are unstrained and the Te atoms are predominantly substituted in the top S sublattice. Importantly, such ultimately thin Janus structure of MoS2(1-x)Te2x exhibits properties that are distinct from their constituents. We believe our results will inspire further exploration of the versatile properties of asymmetric 2D TMD alloys.

Conservation in the Teaching Laboratory--Substitution of Xenopus for Rana.

ERIC Educational Resources Information Center

Bernhart, David M; And Others

1991-01-01

Reports on experimental comparisons between the leopard frog, currently captured for laboratory use, and the African clawed frog, raised specifically for research. Except for the increased longevity of isolated nerve axons in the clawed frog, no other significant differences were established. Recommends laboratory use of clawed frogs as…

A Comparison of Missing-Data Procedures for Arima Time-Series Analysis

ERIC Educational Resources Information Center

Velicer, Wayne F.; Colby, Suzanne M.

2005-01-01

Missing data are a common practical problem for longitudinal designs. Time-series analysis is a longitudinal method that involves a large number of observations on a single unit. Four different missing-data methods (deletion, mean substitution, mean of adjacent observations, and maximum likelihood estimation) were evaluated. Computer-generated…

Comparison of Relative Binding Affinities for Trout and Human Estrogen Receptor Based upon Different Competitive Binding Assays

EPA Science Inventory

The development of a predictive model based upon a single aquatic species inevitably raises the question of whether this information is valid for other species. To partially address this question, relative binding affinities (RBA) for six alkylphenols (para-substituted, n- and b...

Easy sellar reconstruction in endoscopic endonasal transsphenoidal surgery with polyester-silicone dural substitute and fibrin glue: technical note.

PubMed

Cappabianca, P; Cavallo, L M; Mariniello, G; de Divitiis, O; Romero, A D; de Divitiis, E

2001-08-01

To describe a simple method of sellar reconstruction after endoscopic endonasal transsphenoidal surgery that will allow rapid watertight closure of the sellar floor. A bent sheet of a polyester-silicone dural substitute, fashioned for this purpose with scissors, is introduced into the sella after removal of the lesion. Because of the consistency of the sheet, it opens spontaneously and becomes stuck. Autologous fat tissue or gelatin foam is positioned thereafter, followed by another layer of the dural substitute; a film of fibrin glue completes the sealing. Fifteen patients underwent this method and no postoperative cerebrospinal leak or other complication was experienced. This easy method of sellar reconstruction represents an effective and fast possibility to perform the final step of the endoscopic transsphenoidal procedure, which otherwise may cause maneuverability problems in the limited space of one nostril.

Substituted 2-Phenyl-Imidazopyridines: A New Class of Drug Leads for Human African Trypanosomiasis

PubMed Central

Tatipaka, Hari Babu; Gillespie, J. Robert; Chatterjee, Arnab K.; Norcross, Neil R.; Hulverson, Matthew A.; Ranade, Ranae M.; Nagendar, Pendem; Creason, Sharon A.; McQueen, Joshua; Duster, Nicole A.; Nagle, Advait; Supek, Frantisek; Molteni, Valentina; Wenzler, Tanja; Brun, Reto; Glynne, Richard; Buckner, Frederick S.; Gelb, Michael H.

2014-01-01

A phenotypic screen of a compound library for antiparasitic activity on Trypanosoma brucei, the causative agent of human African trypanosomiasis, led to the identification of substituted 2-(3-aminophenyl) oxazolopyridines as a starting point for hit-to-lead medicinal chemistry. A total of 110 analogues were prepared, which led to the identification of 64, a substituted 2-(3-aminophenyl) imidazopyridine. This compound showed antiparasitic activity in vitro with an EC50 of 2 nM and displayed reasonable drug-like properties when tested in a number of in vitro assays. The compound was orally bioavailable and displayed good plasma and brain exposure in mice. Compound 64 cured mice infected with Trypanosoma brucei when dosed orally down to 2.5 mg/kg. Given its potent anti-parasitic properties and its ease of synthesis, compound 64 represents a new lead for the development of drugs to treat human African trypanosomiasis. PMID:24354316

Convergent evolution of the genomes of marine mammals

USGS Publications Warehouse

Foote, Andrew D.; Liu, Yue; Thomas, Gregg W.C.; Vinař, Tomáš; Alföldi, Jessica; Deng, Jixin; Dugan, Shannon; van Elk, Cornelis E.; Hunter, Margaret; Joshi, Vandita; Khan, Ziad; Kovar, Christie; Lee, Sandra L.; Lindblad-Toh, Kerstin; Mancia, Annalaura; Nielsen, Rasmus; Qin, Xiang; Qu, Jiaxin; Raney, Brian J.; Vijay, Nagarjun; Wolf, Jochen B. W.; Hahn, Matthew W.; Muzny, Donna M.; Worley, Kim C.; Gilbert, M. Thomas P.; Gibbs, Richard A.

2015-01-01

Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and therefore represent a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and performed de novo assembly of the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders that share independently evolved phenotypic adaptations to a marine existence. Our comparative genomic analyses found that convergent amino acid substitutions were widespread throughout the genome and that a subset of these substitutions were in genes evolving under positive selection and putatively associated with a marine phenotype. However, we found higher levels of convergent amino acid substitutions in a control set of terrestrial sister taxa to the marine mammals. Our results suggest that, whereas convergent molecular evolution is relatively common, adaptive molecular convergence linked to phenotypic convergence is comparatively rare.

Computational Fluid Dynamics Assessment Associated with Transcatheter Heart Valve Prostheses: A Position Paper of the ISO Working Group.

PubMed

Wei, Zhenglun Alan; Sonntag, Simon Johannes; Toma, Milan; Singh-Gryzbon, Shelly; Sun, Wei

2018-04-19

The governing international standard for the development of prosthetic heart valves is International Organization for Standardization (ISO) 5840. This standard requires the assessment of the thrombus potential of transcatheter heart valve substitutes using an integrated thrombus evaluation. Besides experimental flow field assessment and ex vivo flow testing, computational fluid dynamics is a critical component of this integrated approach. This position paper is intended to provide and discuss best practices for the setup of a computational model, numerical solving, post-processing, data evaluation and reporting, as it relates to transcatheter heart valve substitutes. This paper is not intended to be a review of current computational technology; instead, it represents the position of the ISO working group consisting of experts from academia and industry with regards to considerations for computational fluid dynamic assessment of transcatheter heart valve substitutes.

Chemical alternatives assessment: the case of flame retardants.

PubMed

Howard, Gregory J

2014-12-01

Decisions on chemical substitution are made rapidly and by many stakeholders; these decisions may have a direct impact on consumer exposures, and, when a hazard exists, to consumer risks. Flame retardants (FRs) represent particular challenges, including very high production volumes, designed-in persistence, and often direct consumer exposure. Newer FR products, as with other industrial chemicals, typically lack data on hazard and exposure, and in many cases even basic information on structure and use in products is unknown. Chemical alternatives assessment (CAA) provides a hazard-focused approach to distinguishing between possible substitutions; variations on this process are used by several government and numerous corporate entities. By grouping chemicals according to functional use, some information on exposure potential can be inferred, allowing for decisions based on those hazard properties that are most distinguishing. This approach can help prevent the "regrettable substitution" of one chemical with another of equal, or even higher, risk. Copyright © 2014 Elsevier Ltd. All rights reserved.

Structural and magnetic properties of ytterbium substituted spinel ferrites

NASA Astrophysics Data System (ADS)

Alonizan, Norah H.; Qindeel, Rabia

2018-06-01

Chemical co-precipitation route adopted to synthesize the magnetic materials. In the present work, iron is replaced by ytterbium ion in manganese-based spinel ferrites. The yield chemically represented by MnYb x Fe2- x O4 ( x = 0.00, 0.025, 0.05, 0.075, 0.10) and its structural, magnetic and electrical properties were observed. The cubic structure of spinel ferrites was confirmed by X-ray diffraction analysis. Spherically shaped grains were perceived in SEM pictures and size lessened with the growth of ytterbium concentration. SEM profile also shows little irregularity in spherical particles. The substitution of ytterbium (Yb) results in the enhancement of electrical resistivity. The resistivity was reduced with the gradual increase in temperature from 303 to 693 K. The trend of activation energy was found to be similar to that of room temperature resistivity. The coercivity of samples was raised with Yb-ion substitution while saturation magnetization and remanence reduced.

Population Policy: Abortion and Modern Contraception Are Substitutes.

PubMed

Miller, Grant; Valente, Christine

2016-08-01

A longstanding debate exists in population policy about the relationship between modern contraception and abortion. Although theory predicts that they should be substitutes, the empirical evidence is difficult to interpret. What is required is a large-scale intervention that alters the supply (or full price) of one or the other and, importantly, that does so in isolation (reproductive health programs often bundle primary health care and family planning-and in some instances, abortion services). In this article, we study Nepal's 2004 legalization of abortion provision and subsequent expansion of abortion services, an unusual and rapidly implemented policy meeting these requirements. Using four waves of rich individual-level data representative of fertile-age Nepalese women, we find robust evidence of substitution between modern contraception and abortion. This finding has important implications for public policy and foreign aid, suggesting that an effective strategy for reducing expensive and potentially unsafe abortions may be to expand the supply of modern contraceptives.

Chapter 8: Pyrolysis Mechanisms of Lignin Model Compounds Using a Heated Micro-Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robichaud, David J.; Nimlos, Mark R.; Ellison, G. Barney

2015-10-03

Lignin is an important component of biomass, and the decomposition of its thermal deconstruction products is important in pyrolysis and gasification. In this chapter, we investigate the unimolecular pyrolysis chemistry through the use of singly and doubly substituted benzene molecules that are model compounds representative of lignin and its primary pyrolysis products. These model compounds are decomposed in a heated micro-reactor, and the products, including radicals and unstable intermediates, are measured using photoionization mass spectrometry and matrix isolation infrared spectroscopy. We show that the unimolecular chemistry can yield insight into the initial decomposition of these species. At pyrolysis and gasificationmore » severities, singly substituted benzenes typically undergo bond scission and elimination reactions to form radicals. Some require radical-driven chain reactions. For doubly substituted benzenes, proximity effects of the substituents can change the reaction pathways.« less

Electronic states of carbon alloy catalysts and nitrogen substituent effects on catalytic activity

NASA Astrophysics Data System (ADS)

Hata, Tomoyuki; Ushiyama, Hiroshi; Yamashita, Koichi

2013-03-01

In recent years, Carbon Alloy Catalysts (CACs) are attracting attention as a candidate for non-platinum-based cathode catalysts in fuel cells. Oxygen reduction reactions at the cathode are divided into two elementary processes, electron transfer and oxygen adsorption. The electron transfer reaction is the rate-determining, and by comparison of energy levels, catalytic activity can be evaluated quantitatively. On the other hand, to begin with, adsorption mechanism is obscure. The purpose of this study is to understand the effect of nitrogen substitution and oxygen adsorption mechanism, by first-principle electronic structure calculations for nitrogen substituted models. To reproduce the elementary processes of oxygen adsorption, we assumed that the initial structures are formed based on the Pauling model, a CACs model and nitrogen substituted CACs models in which various points are replaced with nitrogen. When we try to focus only on the DOS peaks of oxygen, in some substituted model that has high adsorption activity, a characteristic partial occupancy state was found. We conclude that this state will affect the adsorption activity, and discuss on why partially occupied states appear with simplification by using an orbital correlation diagram.

Adhesion of protein residues to substituted (111) diamond surfaces: an insight from density functional theory and classical molecular dynamics simulations.

PubMed

Borisenko, Konstantin B; Reavy, Helen J; Zhao, Qi; Abel, Eric W

2008-09-15

Protein-repellent diamond coatings have great potential value for surface coatings on implants and surgical instruments. The design of these coatings relies on a fundamental understanding of the intermolecular interactions involved in the adhesion of proteins to surfaces. To get insight into these interactions, adhesion energies of glycine to pure and Si and N-doped (111) diamond surfaces represented as clusters were calculated in the gas phase, using density functional theory (DFT) at the B3LYP/6-31G* level. The computed adhesion energies indicated that adhesion of glycine to diamond surface may be modified by introducing additional elements into the surface. The adhesion was also found to induce considerable change in the conformation of glycine when compared with the lowest-energy conformer of the free molecule. In the Si and N-substituted diamond clusters, notable changes in the structures involving the substituents atoms when compared with smaller parent molecules, such as 1-methyl-1-silaadamantane and 1-azaadamantane, were detected. Adhesion free energy differences were estimated for a series of representative peptides (hydrophobic Phe-Gly-Phe, amphiphilic Arg-Gly-Phe, and hydrophilic Arg-Gly-Arg) to a (111) diamond surface substituted with different amounts of N, Si, or F, using molecular dynamics simulations in an explicit water environment employing a Dreiding force field. The calculations were in agreement with the DFT results in that adsorption of the studied peptides to diamond surface is influenced by introducing additional elements to the surface. It has been shown that, in general, substitution will enhance electrostatic interactions between a surface and surrounding water, leading to a weaker adhesion of the studied peptides.

ONCOGENIC BASE SUBSTITUTION MUTATIONS IN CIRCULATING LEUKOCYTES OF NORMAL INDIVIDUALS. (R825810)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

METABOLIC RATE MODELS AND THE SUBSTITUTABILITY OF PREDATOR POPULATIONS. (R825795)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

7 CFR 800.99 - Checkweighing sacked grain.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the instructions. (c) Protecting samples and data. Official personnel and other employees of an agency or the Service shall protect official weight samples and data from manipulation, substitution, and improper and careless handling which might deprive the samples and sample data of their representativeness...

7 CFR 800.99 - Checkweighing sacked grain.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the instructions. (c) Protecting samples and data. Official personnel and other employees of an agency or the Service shall protect official weight samples and data from manipulation, substitution, and improper and careless handling which might deprive the samples and sample data of their representativeness...

The genesis of an exceptionally lethal venom in the timber rattlesnake (Crotalus horridus) revealed through comparative venom-gland transcriptomics

PubMed Central

2013-01-01

Background Snake venoms generally show sequence and quantitative variation within and between species, but some rattlesnakes have undergone exceptionally rapid, dramatic shifts in the composition, lethality, and pharmacological effects of their venoms. Such shifts have occurred within species, most notably in Mojave (Crotalus scutulatus), South American (C. durissus), and timber (C. horridus) rattlesnakes, resulting in some populations with extremely potent, neurotoxic venoms without the hemorrhagic effects typical of rattlesnake bites. Results To better understand the evolutionary changes that resulted in the potent venom of a population of C. horridus from northern Florida, we sequenced the venom-gland transcriptome of an animal from this population for comparison with the previously described transcriptome of the eastern diamondback rattlesnake (C. adamanteus), a congener with a more typical rattlesnake venom. Relative to the toxin transcription of C. adamanteus, which consisted primarily of snake-venom metalloproteinases, C-type lectins, snake-venom serine proteinases, and myotoxin-A, the toxin transcription of C. horridus was far simpler in composition and consisted almost entirely of snake-venom serine proteinases, phospholipases A2, and bradykinin-potentiating and C-type natriuretic peptides. Crotalus horridus lacked significant expression of the hemorrhagic snake-venom metalloproteinases and C-type lectins. Evolution of shared toxin families involved differential expansion and loss of toxin clades within each species and pronounced differences in the highly expressed toxin paralogs. Toxin genes showed significantly higher rates of nonsynonymous substitution than nontoxin genes. The expression patterns of nontoxin genes were conserved between species, despite the vast differences in toxin expression. Conclusions Our results represent the first complete, sequence-based comparison between the venoms of closely related snake species and reveal in unprecedented detail the rapid evolution of snake venoms. We found that the difference in venom properties resulted from major changes in expression levels of toxin gene families, differential gene-family expansion and loss, changes in which paralogs within gene families were expressed at high levels, and higher nonsynonymous substitution rates in the toxin genes relative to nontoxins. These massive alterations in the genetics of the venom phenotype emphasize the evolutionary lability and flexibility of this ecologically critical trait. PMID:23758969

The lunar libration: comparisons between various models - a model fitted to LLR observations

NASA Astrophysics Data System (ADS)

Chapront, J.; Francou, G.

2005-09-01

We consider 4 libration models: 3 numerical models built by JPL (ephemerides for the libration in DE245, DE403 and DE405) and an analytical model improved with numerical complements fitted to recent LLR observations. The analytical solution uses 3 angular variables (ρ1, ρ2, τ) which represent the deviations with respect to Cassini's laws. After having referred the models to a unique reference frame, we study the differences between the models which depend on gravitational and tidal parameters of the Moon, as well as amplitudes and frequencies of the free librations. It appears that the differences vary widely depending of the above quantities. They correspond to a few meters displacement on the lunar surface, reminding that LLR distances are precise to the centimeter level. Taking advantage of the lunar libration theory built by Moons (1984) and improved by Chapront et al. (1999) we are able to establish 4 solutions and to represent their differences by Fourier series after a numerical substitution of the gravitational constants and free libration parameters. The results are confirmed by frequency analyses performed separately. Using DE245 as a basic reference ephemeris, we approximate the differences between the analytical and numerical models with Poisson series. The analytical solution - improved with numerical complements under the form of Poisson series - is valid over several centuries with an internal precision better than 5 centimeters.

Bridging two scholarly islands enriches both: COI DNA barcodes for species identification versus human mitochondrial variation for the study of migrations and pathologies.

PubMed

Thaler, David S; Stoeckle, Mark Y

2016-10-01

DNA barcodes for species identification and the analysis of human mitochondrial variation have developed as independent fields even though both are based on sequences from animal mitochondria. This study finds questions within each field that can be addressed by reference to the other. DNA barcodes are based on a 648-bp segment of the mitochondrially encoded cytochrome oxidase I. From most species, this segment is the only sequence available. It is impossible to know whether it fairly represents overall mitochondrial variation. For modern humans, the entire mitochondrial genome is available from thousands of healthy individuals. SNPs in the human mitochondrial genome are evenly distributed across all protein-encoding regions arguing that COI DNA barcode is representative. Barcode variation among related species is largely based on synonymous codons. Data on human mitochondrial variation support the interpretation that most - possibly all - synonymous substitutions in mitochondria are selectively neutral. DNA barcodes confirm reports of a low variance in modern humans compared to nonhuman primates. In addition, DNA barcodes allow the comparison of modern human variance to many other extant animal species. Birds are a well-curated group in which DNA barcodes are coupled with census and geographic data. Putting modern human variation in the context of intraspecies variation among birds shows humans to be a single breeding population of average variance.

Hannaella phyllophila sp. nov., a basidiomycetous yeast species associated with plants in Thailand and Taiwan.

PubMed

Surussawadee, Janjira; Jindamorakot, Sasitorn; Nakase, Takashi; Lee, Ching-Fu; Limtong, Savitree

2015-07-01

Five strains representing one novel anamorphic yeast species were isolated from plant leaves collected in Thailand (strains DMKU-SP186(T), ST-111 and ST-201) and Taiwan (strains FN20L02 and SM13L16). On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, they were assigned to a single novel species of the genus Hannaella. The sequences of the D1/D2 regions of the LSU rRNA genes of four of the strains (DMKU-SP186(T), ST-111, FN20L02 and SM13L16) were identical, while differing from strain ST-201 by 2 substitutions and 2 gaps. The nucleotide sequence of the ITS regions of the five strains differed from each other by between 0 and 3 nucleotide substitutions. The novel species was most closely related to Hannaella luteola, but showed 1.0-1.3% nucleotide substitutions (between 6 substitutions out of 568-606 nt and 8 substitutions, and 2 gaps out of 597 nt) in the D1/D2 region of the LSU rRNA gene and 1.4-2.0% nucleotide substitutions (6-9 substitutions out of 435 nt) in the ITS region. Ballistospores were produced by three of the strains on cornmeal agar at 15 and 20 °C after 4 weeks, while H. luteola did not produce ballistospores. The name Hannaella phyllophila sp. nov. is proposed. The type strain is DMKU-SP186(T) ( = BCC 69500(T) = NBRC 110428(T) = CBS 13921(T)).

Three-Dimensional Structures Reveal Multiple ADP/ATP Binding Modes

DOE Office of Scientific and Technical Information (OSTI.GOV)

C Simmons; C Magee; D Smith

The creation of synthetic enzymes with predefined functions represents a major challenge in future synthetic biology applications. Here, we describe six structures of de novo proteins that have been determined using protein crystallography to address how simple enzymes perform catalysis. Three structures are of a protein, DX, selected for its stability and ability to tightly bind ATP. Despite the addition of ATP to the crystallization conditions, the presence of a bound but distorted ATP was found only under excess ATP conditions, with ADP being present under equimolar conditions or when crystallized for a prolonged period of time. A bound ADPmore » cofactor was evident when Asp was substituted for Val at residue 65, but ATP in a linear configuration is present when Phe was substituted for Tyr at residue 43. These new structures complement previously determined structures of DX and the protein with the Phe 43 to Tyr substitution [Simmons, C. R., et al. (2009) ACS Chem. Biol. 4, 649-658] and together demonstrate the multiple ADP/ATP binding modes from which a model emerges in which the DX protein binds ATP in a configuration that represents a transitional state for the catalysis of ATP to ADP through a slow, metal-free reaction capable of multiple turnovers. This unusual observation suggests that design-free methods can be used to generate novel protein scaffolds that are tailor-made for catalysis.« less

Regioselective Aziridination of Silyl Allenes and Application for the Synthesis of New Heterocycles

NASA Astrophysics Data System (ADS)

Burke, Eileen Grace

Rhodium catalyzed aziridination of homoallenic sulfamates has proven to be a successful first step in the synthesis of a diverse array of complex nitrogenated motifs. Previously, however, the resultant methyleneaziridine was limited to the exocyclic isomer. In this work, a reliable direction strategy for the formation of the endocyclic isomer was identified. Placement of a silicon group on the allene so that its C - Si bond is co-planar to the distal pi-bond allowed for stabilization of the developing positive charge during aziridination, and therefore selective activation to form the endocyclic methyleneaziridine. This strategy proved robust, and endocyclic methyleneaziridines were formed in high yields with exclusive formation of the desired isomer regardless of the substitution of the allene. With the endocyclic isomer now readily available, its reactivity could be explored. First, the endocyclic methyleneaziridine was applied to the synthesis of densely functionalized, nitrogen containing motifs. In comparison with their exocyclic counterparts, the endocyclic methyleneaziridines were found to have differing reactivity. The olefin could be epoxidized using meta-chloroperoxybenzoic acid (mCPBA), and the resulting spirocyclic intermediate rapidly rearranged to an azetidin-3-one. This synthesis of the highly substituted fourmembered heterocycle represented a novel approach to these motifs, and was found to be both flexible, and to selectively form a single diastereomer. Additional derivatization of these scaffolds gave a diverse array of complex products. Further use of the endocyclic methyleneaziridine focused not on the complexity of the product motif but rather on its utility. The remaining silyl group could be eliminated upon reaction with a fluoride source, triggering the formation of an alkyne and resultant opening of the aziridine. This strained heterocyclic alkyne and its synthesis represent a new addition to the field of strained alkyne synthesis. Uniquely, the arrangement of heteroatoms activated the alkyne without allowing for detrimental relaxation of ring strain, giving a strained alkyne that balanced reactivity and stability. These alkynes were applied to post-polymerization modification, wherein their unique capability of opening the strain inducing ring after reaction of the alkyne was successfully demonstrated.

Insights into evolution in Andean Polystichum (Dryopteridaceae) from expanded understanding of the cytosolic phosphoglucose isomerase gene.

PubMed

Lyons, Brendan M; McHenry, Monique A; Barrington, David S

2017-07-01

Cytosolic phosphoglucose isomerase (pgiC) is an enzyme essential to glycolysis found universally in eukaryotes, but broad understanding of variation in the gene coding for pgiC is lacking for ferns. We used a substantially expanded representation of the gene for Andean species of the fern genus Polystichum to characterize pgiC in ferns relative to angiosperms, insects, and an amoebozoan; assess the impact of selection versus neutral evolutionary processes on pgiC; and explore evolutionary relationships of selected Andean species. The dataset of complete sequences comprised nine accessions representing seven species and one hybrid from the Andes and Serra do Mar. The aligned sequences of the full data set comprised 3376 base pairs (70% of the entire gene) including 17 exons and 15 introns from two central areas of the gene. The exons are highly conserved relative to angiosperms and retain substantial homology to insect pgiC, but intron length and structure are unique to the ferns. Average intron size is similar to angiosperms; intron number and location in insects are unlike those of the plants we considered. The introns included an array of indels and, in intron 7, an extensive microsatellite array with potential utility in analyzing population-level histories. Bayesian and maximum-parsimony analysis of 129 variable nucleotides in the Andean polystichums revealed that 59 (1.7% of the 3376 total) were phylogenetically informative; most of these united sister accessions. The phylogenetic trees for the Andean polystichums were incongruent with previously published cpDNA trees for the same taxa, likely the result of rapid evolutionary change in the introns and contrasting stability in the exons. The exons code a total of seven amino-acid substitutions. Comparison of non-synonymous to synonymous substitutions did not suggest that the pgiC gene is under selection in the Andes. Variation in pgiC including two additional accessions represented by incomplete sequences provided new insights into reticulate relationships among Andean taxa. Copyright © 2017 Elsevier Inc. All rights reserved.

Liquid rocket booster study. Volume 2, book 6, appendix 10: Vehicle systems effects

NASA Technical Reports Server (NTRS)

1989-01-01

Three tasks were undertaken by Eagle Engineering as a part of the Liquid Rocket Booster (LRB) study. Task 1 required Eagle to supply current data relative to the Space Shuttle vehicle and systems affected by an LRB substitution. Tables listing data provided are presented. Task 2 was to evaluate and compare shuttle impacts of candidate LRB configuration in concert with overall trades of analysis activity. Three selected configurations with emphasis on flight loads, separation dynamics, and cost comparison are presented. Task 3 required the development of design guidelines and requirements to minimize impacts to the Space Shuttle system from all LRB substitution. Results are presented for progress to date.

A method to measure the density of seawater accurately to the level of 10-6

NASA Astrophysics Data System (ADS)

Schmidt, Hannes; Wolf, Henning; Hassel, Egon

2016-04-01

A substitution method to measure seawater density relative to pure water density using vibrating tube densimeters was realized and validated. Standard uncertainties of 1 g m-3 at atmospheric pressure, 10 g m-3 up to 10 MPa, and 20 g m-3 to 65 MPa in the temperature range of 5 °C to 35 °C and for salt contents up to 35 g kg-1 were achieved. The realization was validated by comparison measurements with a hydrostatic weighing apparatus for atmospheric pressure. For high pressures, literature values of seawater compressibility were compared with substitution measurements of the realized apparatus.

Structure-activity relationship of prenyl-substituted polyphenols from Artocarpus heterophyllus as inhibitors of melanin biosynthesis in cultured melanoma cells.

PubMed

Arung, Enos Tangke; Shimizu, Kuniyoshi; Kondo, Ryuichiro

2007-09-01

A series of prenylated, flavone-based polyphenols, compounds 1-8, were isolated from the wood of Artocarpus heterophyllus. These compounds, which have previously been shown not to inhibit tyrosinase activity, were found to be active inhibitors of the in vivo melanin biosynthesis in B16 melanoma cells, with little or no cytotoxicity. To clarify the structural requirement for inhibition, some structure-activity relationships were studied, in comparison with related compounds lacking prenyl side chains. Our experiments indicate that both prenyl and OH groups, as well as the type of substitution pattern, are crucial for the inhibition of melanin production in B16 melanoma cells.

10 CFR 431.17 - Determination of efficiency.

Code of Federal Regulations, 2011 CFR

2011-01-01

... different horsepowers without duplication; (C) The basic models should be of different frame number series... be produced over a reasonable period of time (approximately 180 days), then each unit shall be tested... design may be substituted without requiring additional testing if the represented measures of energy...

78 FR 23599 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-19

... public comment on new or revised data collections, the Railroad Retirement Board (RRB) will publish... Substitution of Payee, obtains information needed to determine the selection of a representative payee who will... regarding the information collection should be addressed to Charles Mierzwa, Railroad Retirement Board, 844...

INHIBITION OF LPS-INDUCED SPLENOCYTE PROLIFERATION BY ORTHO-SUBSTITUTED POLYCHLORINATED BIPHENYL CONGENERS. (R826687)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Analysis of phenolic choline esters from seeds of Arabidopsis thaliana and Brassica napus by capillary liquid chromatography/electrospray- tandem mass spectrometry.

PubMed

Böttcher, Christoph; von Roepenack-Lahaye, Edda; Schmidt, Jürgen; Clemens, Stephan; Scheel, Dierk

2009-04-01

Total phenolic choline ester fractions prepared from seeds of Arabidopsis thaliana and Brassica napus were analyzed by capillary LC/ESI-QTOF-MS and direct infusion ESI-FTICR-MS. In addition to the dominating sinapoylcholine, 30 phenolic choline esters could be identified based on accurate mass measurements, interpretation of collision-induced dissociation (CID) mass spectra, and synthesis of selected representatives. The compounds identified so far include substituted hydroxycinnamoyl- and hydroxybenzoylcholines, respective monohexosides as well as oxidative coupling products of phenolic choline esters and monolignols. Phenolic choline esters are well separable by reversed-phase liquid chromatography and sensitively detectable using electrospray ionization mass spectrometry in positive ion mode. CID mass spectra obtained from molecular ions facilitate the characterization of both the type and substitution pattern of such compounds. Therefore, LC/ESI-MS/MS represents a valuable tool for comprehensive qualitative and quantitative analysis of this compound class. Copyright (c) 2009 John Wiley & Sons, Ltd.

Beyond C, H, O, and N! Analysis of the elemental composition of U.S. FDA approved drug architectures.

PubMed

Smith, Brandon R; Eastman, Candice M; Njardarson, Jon T

2014-12-11

The diversity of elements among U.S. Food and Drug Administration (FDA) approved pharmaceuticals is analyzed and reported, with a focus on atoms other than carbon, hydrogen, oxygen, and nitrogen. Our analysis reveals that sulfur, chlorine, fluorine, and phosphorous represent about 90% of elemental substitutions, with sulfur being the fifth most used element followed closely by chlorine, then fluorine and finally phosphorous in the eighth place. The remaining 10% of substitutions are represented by 16 other elements of which bromine, iodine, and iron occur most frequently. The most detailed parts of our analysis are focused on chlorinated drugs as a function of approval date, disease condition, chlorine attachment, and structure. To better aid our chlorine drug analyses, a new poster showcasing the structures of chlorinated pharmaceuticals was created specifically for this study. Phosphorus, bromine, and iodine containing drugs are analyzed closely as well, followed by a discussion about other elements.

Glyphosate-Resistant Goosegrass. Identification of a Mutation in the Target Enzyme 5-Enolpyruvylshikimate-3-Phosphate Synthase

PubMed Central

Baerson, Scott R.; Rodriguez, Damian J.; Tran, Minhtien; Feng, Yongmei; Biest, Nancy A.; Dill, Gerald M.

2002-01-01

The spontaneous occurrence of resistance to the herbicide glyphosate in weed species has been an extremely infrequent event, despite over 20 years of extensive use. Recently, a glyphosate-resistant biotype of goosegrass (Eleusine indica) was identified in Malaysia exhibiting an LD50 value approximately 2- to 4-fold greater than the sensitive biotype collected from the same region. A comparison of the inhibition of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) activity by glyphosate in extracts prepared from the resistant (R) and sensitive (S) biotypes revealed an approximately 5-fold higher IC50(glyphosate) for the (R) biotype. Sequence comparisons of the predicted EPSPS mature protein coding regions from both biotypes revealed four single-nucleotide differences, two of which result in amino acid changes. One of these changes, a proline to serine substitution at position 106 in the (R) biotype, corresponds to a substitution previously identified in a glyphosate-insensitive EPSPS enzyme from Salmonella typhimurium. Kinetic data generated for the recombinant enzymes suggests that the second substitution identified in the (R) EPSPS does not contribute significantly to its reduced glyphosate sensitivity. Escherichia coli aroA− (EPSPS deficient) strains expressing the mature EPSPS enzyme from the (R) biotype exhibited an approximately 3-fold increase in glyphosate tolerance relative to strains expressing the mature EPSPS from the (S) biotype. These results provide the first evidence for an altered EPSPS enzyme as an underlying component of evolved glyphosate resistance in any plant species. PMID:12114580

Glyphosate-resistant goosegrass. Identification of a mutation in the target enzyme 5-enolpyruvylshikimate-3-phosphate synthase.

PubMed

Baerson, Scott R; Rodriguez, Damian J; Tran, Minhtien; Feng, Yongmei; Biest, Nancy A; Dill, Gerald M

2002-07-01

The spontaneous occurrence of resistance to the herbicide glyphosate in weed species has been an extremely infrequent event, despite over 20 years of extensive use. Recently, a glyphosate-resistant biotype of goosegrass (Eleusine indica) was identified in Malaysia exhibiting an LD(50) value approximately 2- to 4-fold greater than the sensitive biotype collected from the same region. A comparison of the inhibition of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) activity by glyphosate in extracts prepared from the resistant (R) and sensitive (S) biotypes revealed an approximately 5-fold higher IC(50)(glyphosate) for the (R) biotype. Sequence comparisons of the predicted EPSPS mature protein coding regions from both biotypes revealed four single-nucleotide differences, two of which result in amino acid changes. One of these changes, a proline to serine substitution at position 106 in the (R) biotype, corresponds to a substitution previously identified in a glyphosate-insensitive EPSPS enzyme from Salmonella typhimurium. Kinetic data generated for the recombinant enzymes suggests that the second substitution identified in the (R) EPSPS does not contribute significantly to its reduced glyphosate sensitivity. Escherichia coli aroA- (EPSPS deficient) strains expressing the mature EPSPS enzyme from the (R) biotype exhibited an approximately 3-fold increase in glyphosate tolerance relative to strains expressing the mature EPSPS from the (S) biotype. These results provide the first evidence for an altered EPSPS enzyme as an underlying component of evolved glyphosate resistance in any plant species.

Cytotoxicity investigation of a new hydroxyapatite scaffold with improved structural design.

PubMed

Sjerobabin, Nikola; Čolović, Božana; Petrović, Milan; Marković, Dejan; Živković, Slavoljub; Jokanović, Vukoman

2016-01-01

Biodegradable porous scaffolds are found to be very promising bone substitutes, acting as a temporary physical support to guide new tissue regeneration, until the entire scaffold is totally degraded and replaced by the new tissue. The aim of this study was to investigate cytotoxicity of a synthesized calcium hydroxyapatitebased scaffold, named ALBO-OS, with high porosity and optimal topology. The ALBO-OS scaffold was synthesized by the method of polymer foam template. The analysis of pore geometry and scaffold walls’ topography was made by scanning electron microscope (SEM). The biological investigations assumed the examinations of ALBO-OS cytotoxicity to mouse L929 fibroblasts, using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor (MTT) and lactate dehydrogenase (LDH) tests and inverse phase microscopy. The SEM analysis showed high porosity with fair pore distribution and interesting morphology from the biological standpoint. The biological investigations showed that the material is not cytotoxic to L929 cells. Comparison of ALBO-OS with Bio-Oss, as the global gold standard as a bone substitute, showed similar results in MTT test, while LDH test showed significantly higher rate of cell multiplication with ALBO-OS. The scaffold design from the aspect of pore size, distribution, and topology seems to be very convenient for cell adhesion and occupation, which makes it a promising material as a bone substitute. The results of biological assays proved that ALBO-OS is not cytotoxic for L929 fibroblasts. In comparison with Bio-Oss, similar or even better results were obtained.

Composite Material Application to Liquid Rocket Engines

NASA Technical Reports Server (NTRS)

Judd, D. C.

1982-01-01

The substitution of reinforced plastic composite (RPC) materials for metal was studied. The major objectives were to: (1) determine the extent to which composite materials can be beneficially used in liquid rocket engines; (2) identify additional technology requirements; and (3) determine those areas which have the greatest potential for return. Weight savings, fabrication costs, performance, life, and maintainability factors were considered. Two baseline designs, representative of Earth to orbit and orbit to orbit engine systems, were selected. Weight savings are found to be possible for selected components with the substitution of materials for metal. Various technology needs are identified before RPC material can be used in rocket engine applications.

When the management of nurse absenteeism becomes a cause of absenteeism: a study based on a comparison of two health care facilities.

PubMed

Damart, Sébastien; Kletz, Frédéric

2016-01-01

The study aims to explore perceptions of the causes of nurse absenteeism. Nurse absenteeism is rising in many countries. However, there is little evidence as to how strategies adopted in order to cushion the effects of absenteeism on workload influence absenteeism itself. The study used a 'qualitative' method based on cognitive mapping techniques in order to represent perceptions about absenteeism graphically. The study was conducted in two health-care facilities with a sample of 55 interviewees. Absenteeism is due in part to strategies adopted in order to cushion the effects of absenteeism on organisations. Furthermore, the strategies are self-legitimising. The more they are used, the more they are regarded as normal and useful. A plan to reduce absenteeism among nurses must explicitly take into account the strategies used to cushion its impact. To cushion the effects of absenteeism among caregivers, managers must make trade-offs that take into account, for example, the workload or disruption linked to the substitution of personnel. © 2014 John Wiley & Sons Ltd.

Simultaneous assessment of phase chemistry, phase abundance and bulk chemistry with statistical electron probe micro-analyses: Application to cement clinkers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, William; Krakowiak, Konrad J.; Ulm, Franz-Josef, E-mail: ulm@mit.edu

2014-01-15

According to recent developments in cement clinker engineering, the optimization of chemical substitutions in the main clinker phases offers a promising approach to improve both reactivity and grindability of clinkers. Thus, monitoring the chemistry of the phases may become part of the quality control at the cement plants, along with the usual measurements of the abundance of the mineralogical phases (quantitative X-ray diffraction) and the bulk chemistry (X-ray fluorescence). This paper presents a new method to assess these three complementary quantities with a single experiment. The method is based on electron microprobe spot analyses, performed over a grid located onmore » a representative surface of the sample and interpreted with advanced statistical tools. This paper describes the method and the experimental program performed on industrial clinkers to establish the accuracy in comparison to conventional methods. -- Highlights: •A new method of clinker characterization •Combination of electron probe technique with cluster analysis •Simultaneous assessment of phase abundance, composition and bulk chemistry •Experimental validation performed on industrial clinkers.« less

Comparison of carbohydrate and peptide biotinylation on the immunological activity of IgG1 murine monoclonal antibodies.

PubMed

Miralles, F; Takeda, Y; Escribano, M J

1991-07-05

When the classical amino acid esterification procedure was used for the biotinylation of the IgG1 monoclonal antibody J28 it resulted in a loss of immunological activity. This antibody recognizes the fetoacinar pancreatic (FAP) antigen and the decrease in reactivity was directly proportional to the molar biotin/antibody ratio indicating substitutions at or near the antibody combining site. This effect was specific to J28 since the IgG1 Mab F22 which recognises the same antigen was not damaged by this procedure. Active Mab J28 conjugates were obtained using biotinylation via oligosaccharide moieties. The biotinylation efficiency using this method was dependent on the previous degree of antibody periodate oxidation and the maximal substitution was 3 mol biotin per mol of antibody. Using these conditions the sensitivity of the biotinylated J28 for the FAP antigen was similar to that obtained when using non-substituted antibody in the two antibodies technique.

Evidence that a formyl-substituted iron porphyrin is the prosthetic group of myeloperoxidase: magnetic circular dichroism similarity of the peroxidase to Spirographis heme-reconstituted myoglobin.

PubMed Central

Sono, M; Bracete, A M; Huff, A M; Ikeda-Saito, M; Dawson, J H

1991-01-01

To probe the identity of the active site heme-type prosthetic group of myeloperoxidase, whose structure has not been established unambiguously [proposed structures are (i) a chlorin (dihydroporphyrin) or (ii) a formyl-substituted porphyrin such as present in heme a], Spirographis heme (2-formyl-4-vinyldeuteroheme IX) has been incorporated into apo-myoglobin as a possible iron porphyrin model. Comparison of parallel derivatives of these two green proteins with magnetic circular dichroism spectroscopy reveals considerable similarities between several derivatives of these proteins, including the pyridine hemochromogen, the native ferric, ferrous-oxy, and ferrous-CO forms. In contrast, the magnetic circular dichroism spectra of available iron chlorin (octaethylchlorin) model complexes in analogous ligation and oxidation states do not show any significant spectral similarities to myeloperoxidase. This finding provides important evidence in favor of a formyl-substituted porphyrin as the structure of the prosthetic group macrocycle of myeloperoxidase. PMID:1662385

3,6-Anhydro-l-galactose, a rare sugar from agar, a new anticariogenic sugar to replace xylitol.

PubMed

Yun, Eun Ju; Lee, Ah Reum; Kim, Jung Hyun; Cho, Kyung Mun; Kim, Kyoung Heon

2017-04-15

The significance for anticariogenic sugar substitutes is growing due to increasing demands for dietary sugars and rising concerns of dental caries. Xylitol is widely used as an anticariogenic sugar substitute, but the inhibitory effects of xylitol on Streptococcus mutans, the main cause of tooth decay, are exhibited only at high concentrations. Here, the inhibitory effects of 3,6-anhydro-l-galactose (AHG), a rare sugar from red macroalgae, were evaluated on S. mutans, in comparison with those of xylitol. In the presence of 5g/l of AHG, the growth of S. mutans was retarded. At 10g/l of AHG, the growth and acid production by S. mutans were completely inhibited. However, in the presence of xylitol, at a much higher concentration (i.e., 40g/l), the growth of S. mutans still occurred. These results suggest that AHG can be used as a new anticariogenic sugar substitute for preventing dental caries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dual evaluation of some novel 2-amino-substituted coumarinylthiazoles as anti-inflammatory-antimicrobial agents and their docking studies with COX-1/COX-2 active sites.

PubMed

Chandak, Navneet; Kumar, Pawan; Kaushik, Pawan; Varshney, Parul; Sharma, Chetan; Kaushik, Dhirender; Jain, Sudha; Aneja, Kamal R; Sharma, Pawan K

2014-08-01

Synthesis of total eighteen 2-amino-substituted 4-coumarinylthiazoles including sixteen new compounds (3a-o and 5b) bearing the benzenesulfonamide moiety is described in the present report. All the synthesized target compounds were examined for their in vivo anti-inflammatory (AI) activity and in vitro antimicrobial activity. Results revealed that six compounds (3 d, 3 f, 3 g, 3 h, 3 j and 3 n) exhibited pronounced anti-inflammatory activity comparable to the standard drug indomethacin. AI results were further confirmed by the docking studies of the most active (3n) and the least active compound (3a) with COX-1 and COX-2 active sites. In addition, most of the compounds exhibited moderate antimicrobial activity against Gram-positive bacteria as well as fungal yeast, S. cervisiae. Comparison between 3 and 5 indicated that incorporation of additional substituted pyrazole nucleus into the scaffold significantly enhanced AI activity.

Polymorphism of follicle stimulating hormone beta (FSHβ) subunit gene and its association with litter traits in giant panda.

PubMed

Huang, Xiaoyu; Li, Desheng; Wang, Jiwen; Huang, Yan; Han, Chunchun; Zhang, Guiquan; Huang, Zhi; Wu, Honglin; Wei, Ming; Wang, Guosong; Hu, Haiping; Deng, Tao; He, Tao; Zhou, Yingming; Song, Shixian; Luo, Bo; Zhang, Heming

2013-11-01

The different SSCP patterns of the follicle stimulating hormone beta (FSHβ) gene amplified by three pairs of primers were sequenced. Comparisons among the three nucleotide sequences of three genotypes indicated that three base substitutions (A213T, A91G, and A89C) were detected in FSHβ gene, which A213T substitution led to one amino acids mutation (Lys > Met), and the other two substitutions were synonymous mutations. The AA, AB and BB genotypes patterns obtained by FSHβ primer1 had evident relation with the litter traits, but the SSCP genotypes patterns obtained by FSHβ primer2 and primer3 had no evident relation with the litter traits in giant panda. The giant panda with AA and AB genotype had the largest litter size and multiparity rate compared with the BB genotypes (P < 0.05). We speculated that the giant pandas with the A allele have better litter traits than those with the B allele.

Effect of SiC buffer layer on GaN growth on Si via PA-MBE

NASA Astrophysics Data System (ADS)

Kukushkin, S. A.; Mizerov, A. M.; Osipov, A. V.; Redkov, A. V.; Telyatnik, R. S.; Timoshnev, S. N.

2017-11-01

The study is devoted to comparison of GaN thin films grown on SiC/Si substrates made by the method of atoms substitution with the films grown directly on Si substrates. The growth was performed in a single process via plasma assisted molecular beam epitaxy. The samples were studied via optical microscopy, Raman spectroscopy, ellipsometry, and a comparison of their characteristics was made. Using chemical etching in KOH, the polarity of GaN films grown on SiC/Si and Si substrates was determined.

A comparison of choline:urea and choline:oxalic acid deep eutectic solvents at 338 K

NASA Astrophysics Data System (ADS)

Gilmore, Mark; Moura, Leila M.; Turner, Adam H.; Swadźba-Kwaśny, Małgorzata; Callear, Samantha K.; McCune, Jade A.; Scherman, Oren A.; Holbrey, John D.

2018-05-01

1:2 choline chloride:urea and 1:1 choline chloride:oxalic acid deep eutectic solvents are compared at 338 K using liquid-phase neutron diffraction with H/D isotopic substitution to obtain differential neutron scattering cross sections and fitting of models to the experimental data using Empirical Potential Structure Refinement. In comparison to the previously reported study of choline chloride:urea at 303 K, we observed significant weakening and lengthening of choline-OH⋯Cl- and choline-OH⋯hydrogen-bond acceptor correlations.

Experiment, monitoring, and gradient methods used to infer climate change effects on plant communities yield consistent patterns

Treesearch

Sarah C. Elmendorf; Gregory H.R. Henry; Robert D. Hollisterd; Anna Maria Fosaa; William A. Gould; Luise Hermanutz; Annika Hofgaard; Ingibjorg I. Jonsdottir; Janet C. Jorgenson; Esther Levesque; Borgbor Magnusson; Ulf Molau; Isla H. Myers-Smith; Steven F. Oberbauer; Christian Rixen; Craig E. Tweedie; Marilyn Walkers

2015-01-01

Inference about future climate change impacts typically relies on one of three approaches: manipulative experiments, historical comparisons (broadly defined to include monitoring the response to ambient climate fluctuations using repeat sampling of plots, dendroecology, and paleoecology techniques), and space-for-time substitutions derived from sampling along...

A Comparison of the Anorexic Effects of Chicken, Porcine, Human and Bovine Insulin on the Central Nervous System of Chicks

USDA-ARS?s Scientific Manuscript database

The aim of the present study was to determine if some naturally-occurring substitutions of amino acid residues of insulin could act differentially within the central nervous system (CNS) of neonatal chicks to control ingestive behavior. Intracerebroventricular (ICV) administration of chicken insuli...

Genomic changes in an attenuated genotype I Japanese encephalitis virus and comparison with virulent parental strain.

PubMed

Zhou, Yuyong; Wu, Rui; Feng, Yao; Zhao, Qin; Wen, Xintian; Huang, Xiaobo; Wen, Yiping; Yan, Qigui; Huang, Yong; Ma, Xiaoping; Han, Xinfeng; Cao, Sanjie

2018-06-01

Genotype I Japanese encephalitis virus (JEV) strain SCYA201201 was previously isolated from brain tissues of aborted piglets. In this study, we obtained an attenuated SCYA201201-0901 strain by serial passage of strain SCYA201201-1 in Syrian baby hamster kidney cells, combined with multiple plaque purifications and selection for virulence in mice. We investigated the genetic changes associated with attenuation by comparing the entire genomes of SCYA201201-0901 and SCYA201201-1. Sequence comparisons identified 14 common amino acid substitutions in the coding region, with two nucleotide point mutations in the 5'-untranslated region (UTR) and another three in the 3'-UTR, which differed between the attenuated and virulent strains. In addition, a total of 13 silent nucleotide mutations were found after attenuation. These substitutions, alone or in combination, may be responsible for the attenuated phenotype of the SCYA201201-0901 strain in mice. This information will contribute to our understanding of attenuation and of the molecular basis of virulence in genotype I strains such as SCYA201201-0901, as well as aiding the development of safer JEV vaccines.

DCJ-indel and DCJ-substitution distances with distinct operation costs

PubMed Central

2013-01-01

Background Classical approaches to compute the genomic distance are usually limited to genomes with the same content and take into consideration only rearrangements that change the organization of the genome (i.e. positions and orientation of pieces of DNA, number and type of chromosomes, etc.), such as inversions, translocations, fusions and fissions. These operations are generically represented by the double-cut and join (DCJ) operation. The distance between two genomes, in terms of number of DCJ operations, can be computed in linear time. In order to handle genomes with distinct contents, also insertions and deletions of fragments of DNA – named indels – must be allowed. More powerful than an indel is a substitution of a fragment of DNA by another fragment of DNA. Indels and substitutions are called content-modifying operations. It has been shown that both the DCJ-indel and the DCJ-substitution distances can also be computed in linear time, assuming that the same cost is assigned to any DCJ or content-modifying operation. Results In the present study we extend the DCJ-indel and the DCJ-substitution models, considering that the content-modifying cost is distinct from and upper bounded by the DCJ cost, and show that the distance in both models can still be computed in linear time. Although the triangular inequality can be disrupted in both models, we also show how to efficiently fix this problem a posteriori. PMID:23879938

Bioengineering a Human Plasma-Based Epidermal Substitute With Efficient Grafting Capacity and High Content in Clonogenic Cells

PubMed Central

Alexaline, Maia M.; Trouillas, Marina; Nivet, Muriel; Bourreau, Emilie; Leclerc, Thomas; Duhamel, Patrick; Martin, Michele T.; Doucet, Christelle; Fortunel, Nicolas O.

2015-01-01

Cultured epithelial autografts (CEAs) produced from a small, healthy skin biopsy represent a lifesaving surgical technique in cases of full-thickness skin burn covering >50% of total body surface area. CEAs also present numerous drawbacks, among them the use of animal proteins and cells, the high fragility of keratinocyte sheets, and the immaturity of the dermal-epidermal junction, leading to heavy cosmetic and functional sequelae. To overcome these weaknesses, we developed a human plasma-based epidermal substitute (hPBES) for epidermal coverage in cases of massive burn, as an alternative to traditional CEA, and set up critical quality controls for preclinical and clinical studies. In this study, phenotypical analyses in conjunction with functional assays (clonal analysis, long-term culture, or in vivo graft) showed that our new substitute fulfills the biological requirements for epidermal regeneration. hPBES keratinocytes showed high potential for cell proliferation and subsequent differentiation similar to healthy skin compared with a well-known reference material, as ascertained by a combination of quality controls. This work highlights the importance of integrating relevant multiparameter quality controls into the bioengineering of new skin substitutes before they reach clinical development. Significance This work involves the development of a new bioengineered epidermal substitute with pertinent functional quality controls. The novelty of this work is based on this quality approach. PMID:25848122

Bioengineering a human plasma-based epidermal substitute with efficient grafting capacity and high content in clonogenic cells.

PubMed

Alexaline, Maia M; Trouillas, Marina; Nivet, Muriel; Bourreau, Emilie; Leclerc, Thomas; Duhamel, Patrick; Martin, Michele T; Doucet, Christelle; Fortunel, Nicolas O; Lataillade, Jean-Jacques

2015-06-01

Cultured epithelial autografts (CEAs) produced from a small, healthy skin biopsy represent a lifesaving surgical technique in cases of full-thickness skin burn covering >50% of total body surface area. CEAs also present numerous drawbacks, among them the use of animal proteins and cells, the high fragility of keratinocyte sheets, and the immaturity of the dermal-epidermal junction, leading to heavy cosmetic and functional sequelae. To overcome these weaknesses, we developed a human plasma-based epidermal substitute (hPBES) for epidermal coverage in cases of massive burn, as an alternative to traditional CEA, and set up critical quality controls for preclinical and clinical studies. In this study, phenotypical analyses in conjunction with functional assays (clonal analysis, long-term culture, or in vivo graft) showed that our new substitute fulfills the biological requirements for epidermal regeneration. hPBES keratinocytes showed high potential for cell proliferation and subsequent differentiation similar to healthy skin compared with a well-known reference material, as ascertained by a combination of quality controls. This work highlights the importance of integrating relevant multiparameter quality controls into the bioengineering of new skin substitutes before they reach clinical development. This work involves the development of a new bioengineered epidermal substitute with pertinent functional quality controls. The novelty of this work is based on this quality approach. ©AlphaMed Press.

INDUCING PATTERNS OF CORRELATION AND SUBSTITUTION IN REPEATED LOGIC MODELS OF RECREATION DEMAND. (R825310)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

NUCLEOPHILIC AROMATIC SUBSTITUTION REACTIONS OF CHLOROAZINES WITH BISULFIDE (HS-) AND POLYSULFIDES (SN2-). (R826269)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

COMPARISON OF ECOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

EPA Science Inventory

Obtaining an adequate, representative sample of ecological communities to make taxon richness (TR) or compositional comparisons among sites is a continuing challenge. Sample representativeness literally means the similarity in species composition and relative abundance between a ...

Sensory Substitution: The Spatial Updating of Auditory Scenes “Mimics” the Spatial Updating of Visual Scenes

PubMed Central

Pasqualotto, Achille; Esenkaya, Tayfun

2016-01-01

Visual-to-auditory sensory substitution is used to convey visual information through audition, and it was initially created to compensate for blindness; it consists of software converting the visual images captured by a video-camera into the equivalent auditory images, or “soundscapes”. Here, it was used by blindfolded sighted participants to learn the spatial position of simple shapes depicted in images arranged on the floor. Very few studies have used sensory substitution to investigate spatial representation, while it has been widely used to investigate object recognition. Additionally, with sensory substitution we could study the performance of participants actively exploring the environment through audition, rather than passively localizing sound sources. Blindfolded participants egocentrically learnt the position of six images by using sensory substitution and then a judgment of relative direction task (JRD) was used to determine how this scene was represented. This task consists of imagining being in a given location, oriented in a given direction, and pointing towards the required image. Before performing the JRD task, participants explored a map that provided allocentric information about the scene. Although spatial exploration was egocentric, surprisingly we found that performance in the JRD task was better for allocentric perspectives. This suggests that the egocentric representation of the scene was updated. This result is in line with previous studies using visual and somatosensory scenes, thus supporting the notion that different sensory modalities produce equivalent spatial representation(s). Moreover, our results have practical implications to improve training methods with sensory substitution devices (SSD). PMID:27148000

Amino acid-substituted gemini surfactant-based nanoparticles as safe and versatile gene delivery agents.

PubMed

Singh, Jagbir; Yang, Peng; Michel, Deborah; Verrall, Ronald E; Foldvari, Marianna; Badea, Ildiko

2011-05-01

Gene based therapy represents an important advance in the treatment of diseases that heretofore have had either no treatment or cure. To capitalize on the true potential of gene therapy, there is a need to develop better delivery systems that can protect these therapeutic biomolecules and deliver them safely to the target sites. Recently, we have designed and developed a series of novel amino acid-substituted gemini surfactants with the general chemical formula C(12)H(25) (CH(3))(2)N(+)-(CH(2))(3)-N(AA)-(CH(2))(3)-N(+) (CH(3))(2)-C(12)H(25) (AA= glycine, lysine, glycyl-lysine and, lysyl-lysine). These compounds were synthesized and tested in rabbit epithelial cells using a model plasmid and a helper lipid. Plasmid/gemini/lipid (P/G/L) nanoparticles formulated using these novel compounds achieved higher gene expression than the nanoparticles containing the parent unsubstituted compound. In this study, we evaluated the cytotoxicity of P/G/L nanoparticles and explored the relationship between transfection efficiency/toxicity and their physicochemical characteristics (such as size, binding properties, etc.). An overall low toxicity is observed for all complexes with no significant difference among substituted and unsubstituted compounds. An interesting result revealed by the dye exclusion assay suggests a more balanced protection of the DNA by the glycine and glycyl-lysine substituted compounds. Thus, the higher transfection efficiency is attributed to the greater biocompatibility and flexibility of the amino acid/peptide-substituted gemini surfactants and demonstrates the feasibility of using amino acid-substituted gemini surfactants as gene carriers for the treatment of diseases affecting epithelial tissue.

Traditional knowledge of wild food plants in a few Tibetan communities.

PubMed

Boesi, Alessandro

2014-11-03

This paper aims to present the author's field research data on wild food plant use in Tibetan regions. It provides a general perspective on their significance in past and present Tibet, and examines the concept of wild edible plants as medicinal plants. The fieldwork was conducted in Dhorpatan (Nepal, May-August 1998), Lithang town and surroundings (Sichuan, China, April-September 1999, May-August 2000); Southern Mustang District (Nepal, July-August 2001); and Sapi (Ladakh, Jammu and Kashmir, India, July 1995, August 2005). The research was conducted with 176 informants. The methodology included ethnographic research techniques: participant observation, open-ended conversations, semi-structured interviews, and studies of Tibetan medical texts. The author worked in the field with Tibetan colloquial and written language. The 75 total wild food plants and mushrooms belong to 36 genera and 60 species. 44 specimens are used as vegetables, 10 as spices\\condiments, 15 as fruits, 3 as ferments to prepare yoghurt and beer, 5 as substitutes for tsampa (roasted barley flour, the traditional staple food of Tibetan people), 4 as substitutes for tea, and 3 to prepare other beverages. Data from Lithang, which are more representative, show that among 30 wild food plant species exploited, 21 are consumed as vegetables, 5 as spices, 4 as fruits, 3 represent substitutes for roasted barley flour, 2 substitutes for tea, and 1 is used as fermentation agent. Tibetans have traditionally exploited few wild food plants. These mainly compensate for the lack of vegetables and fruit in traditional Tibetan diet, notably among pastoralists, and are far more important during famines as substitutes for roasted barley flour. Today few wild food plants are regularly consumed, less in the main towns and villages and moreso in remote areas and among pastoralists. Younger generations from towns have almost lost traditional botanical knowledge. Owing to modernisation and globalisation processes, many local people have specialised in collecting natural products increasingly demanded in China and abroad. Tibetan people strongly benefit from these activities. Tibetan medicine sees diet as a way of curing diseases and medical treatises describe therapeutic properties of several wild food plants that Tibetans nowadays consume.

Recovery of West Nile Virus Envelope Protein Domain III Chimeras with Altered Antigenicity and Mouse Virulence

PubMed Central

McAuley, Alexander J.; Torres, Maricela; Plante, Jessica A.; Huang, Claire Y.-H.; Bente, Dennis A.

2016-01-01

ABSTRACT Flaviviruses are positive-sense, single-stranded RNA viruses responsible for millions of human infections annually. The envelope (E) protein of flaviviruses comprises three structural domains, of which domain III (EIII) represents a discrete subunit. The EIII gene sequence typically encodes epitopes recognized by virus-specific, potently neutralizing antibodies, and EIII is believed to play a major role in receptor binding. In order to assess potential interactions between EIII and the remainder of the E protein and to assess the effects of EIII sequence substitutions on the antigenicity, growth, and virulence of a representative flavivirus, chimeric viruses were generated using the West Nile virus (WNV) infectious clone, into which EIIIs from nine flaviviruses with various levels of genetic diversity from WNV were substituted. Of the constructs tested, chimeras containing EIIIs from Koutango virus (KOUV), Japanese encephalitis virus (JEV), St. Louis encephalitis virus (SLEV), and Bagaza virus (BAGV) were successfully recovered. Characterization of the chimeras in vitro and in vivo revealed differences in growth and virulence between the viruses, with in vivo pathogenesis often not being correlated with in vitro growth. Taken together, the data demonstrate that substitutions of EIII can allow the generation of viable chimeric viruses with significantly altered antigenicity and virulence. IMPORTANCE The envelope (E) glycoprotein is the major protein present on the surface of flavivirus virions and is responsible for mediating virus binding and entry into target cells. Several viable West Nile virus (WNV) variants with chimeric E proteins in which the putative receptor-binding domain (EIII) sequences of other mosquito-borne flaviviruses were substituted in place of the WNV EIII were recovered, although the substitution of several more divergent EIII sequences was not tolerated. The differences in virulence and tissue tropism observed with the chimeric viruses indicate a significant role for this sequence in determining the pathogenesis of the virus within the mammalian host. Our studies demonstrate that these chimeras are viable and suggest that such recombinant viruses may be useful for investigation of domain-specific antibody responses and the more extensive definition of the contributions of EIII to the tropism and pathogenesis of WNV or other flaviviruses. PMID:26912625

Recovery of West Nile Virus Envelope Protein Domain III Chimeras with Altered Antigenicity and Mouse Virulence.

PubMed

McAuley, Alexander J; Torres, Maricela; Plante, Jessica A; Huang, Claire Y-H; Bente, Dennis A; Beasley, David W C

2016-05-01

Flaviviruses are positive-sense, single-stranded RNA viruses responsible for millions of human infections annually. The envelope (E) protein of flaviviruses comprises three structural domains, of which domain III (EIII) represents a discrete subunit. The EIII gene sequence typically encodes epitopes recognized by virus-specific, potently neutralizing antibodies, and EIII is believed to play a major role in receptor binding. In order to assess potential interactions between EIII and the remainder of the E protein and to assess the effects of EIII sequence substitutions on the antigenicity, growth, and virulence of a representative flavivirus, chimeric viruses were generated using the West Nile virus (WNV) infectious clone, into which EIIIs from nine flaviviruses with various levels of genetic diversity from WNV were substituted. Of the constructs tested, chimeras containing EIIIs from Koutango virus (KOUV), Japanese encephalitis virus (JEV), St. Louis encephalitis virus (SLEV), and Bagaza virus (BAGV) were successfully recovered. Characterization of the chimeras in vitro and in vivo revealed differences in growth and virulence between the viruses, within vivo pathogenesis often not being correlated within vitro growth. Taken together, the data demonstrate that substitutions of EIII can allow the generation of viable chimeric viruses with significantly altered antigenicity and virulence. The envelope (E) glycoprotein is the major protein present on the surface of flavivirus virions and is responsible for mediating virus binding and entry into target cells. Several viable West Nile virus (WNV) variants with chimeric E proteins in which the putative receptor-binding domain (EIII) sequences of other mosquito-borne flaviviruses were substituted in place of the WNV EIII were recovered, although the substitution of several more divergent EIII sequences was not tolerated. The differences in virulence and tissue tropism observed with the chimeric viruses indicate a significant role for this sequence in determining the pathogenesis of the virus within the mammalian host. Our studies demonstrate that these chimeras are viable and suggest that such recombinant viruses may be useful for investigation of domain-specific antibody responses and the more extensive definition of the contributions of EIII to the tropism and pathogenesis of WNV or other flaviviruses. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Comparison between infrared and Raman spectroscopic analysis of maturing rabbit cortical bone.

PubMed

Turunen, Mikael J; Saarakkala, Simo; Rieppo, Lassi; Helminen, Heikki J; Jurvelin, Jukka S; Isaksson, Hanna

2011-06-01

The molecular composition of the organic and inorganic matrices of bone undergoes alterations during maturation. The aim of this study was to compare Fourier transform infrared (FT-IR) and near-infrared (NIR) Raman microspectroscopy techniques for characterization of the composition of growing and developing bone from young to skeletally mature rabbits. Moreover, the specificity and differences of the techniques for determining bone composition were clarified. The humeri of female New Zealand White rabbits, with age range from young to skeletally mature animals (four age groups, n = 7 per group), were studied. Spectral peak areas, intensities, and ratios related to organic and inorganic matrices of bone were analyzed and compared between the age groups and between FT-IR and Raman microspectroscopic techniques. Specifically, the degree of mineralization, type-B carbonate substitution, crystallinity of hydroxyapatite (HA), mineral content, and collagen maturity were examined. Significant changes during maturation were observed in various compositional parameters with one or both techniques. Overall, the compositional parameters calculated from the Raman spectra correlated with analogous parameters calculated from the IR spectra. Collagen cross-linking (XLR), as determined through peak fitting and directly from the IR spectra, were highly correlated. The mineral/matrix ratio in the Raman spectra was evaluated with multiple different peaks representing the organic matrix. The results showed high correlation with each other. After comparison with the bone mineral density (BMD) values from micro-computed tomography (micro-CT) imaging measurements and crystal size from XRD measurements, it is suggested that Raman microspectroscopy is more sensitive than FT-IR microspectroscopy for the inorganic matrix of the bone. In the literature, similar spectroscopic parameters obtained with FT-IR and NIR Raman microspectroscopic techniques are often compared. According to the present results, however, caution is required when performing this kind of comparison.

Dural Repair in Cranial Surgery Is Associated with Moderate Rates of Complications with Both Autologous and Nonautologous Dural Substitutes.

PubMed

Azzam, Daniel; Romiyo, Prasanth; Nguyen, Thien; Sheppard, John P; Alkhalid, Yasmine; Lagman, Carlito; Prashant, Giyarpuram N; Yang, Isaac

2018-05-01

Duraplasty, a common neurosurgical intervention, involves synthetic or biological graft placement to ensure dural closure. The objective of this study is to advance our understanding of the use of dural substitutes in cranial surgery. The PubMed database was systematically searched to identify studies published over the past decade (2007-2017) that described duraplasty procedures. Clinical data were disaggregated and analyzed for the comparisons of biological versus synthetic grafts. A total of 462 cases were included in the quantitative synthesis. Overall, the most common indication for duraplasty was tumor resection (53%). Allografts were more frequently used in decompression for Chiari malformations compared with xenografts and synthetic grafts (P < 0.001). Xenografts were more frequently used in decompressive hemicraniectomy procedures for evacuation of acute subdural hematomas over allografts and synthetics (P < 0.001). Synthetic grafts were more frequently used in tumor cases than biological grafts (P = 0.002). The cumulative complication rate for dural substitutes of all types was 11%. There were no significant differences in complication rates among the 3 types of dural substitutes. Dural substitutes are commonly used to ensure dural closure in a variety of cranial procedures. This study provides greater insight into duraplasty practices and highlights the moderate complication rate associated with the procedure. Future studies are needed to determine the safety and efficacy of such procedures in larger prospective cohorts. Copyright © 2018. Published by Elsevier Inc.

Effect of Ni and Ti substitutions on Li1.05Mn2O4-δ electrical conductivities at high temperature

NASA Astrophysics Data System (ADS)

Abe, Satoko; Iwasaki, Shoko; Shimonishi, Yuta; Komine, Shigeki; Munakata, Fumio

2016-10-01

Samples of Li1.05Mn2O4-δ, Li1.05Mn1.5Ni0.5O4-δ, and Li1.05Mn1.0Ni0.5Ti0.5O4-δ were prepared by a solid-state reaction technique and ultimately refined to a space group Fd-3m of spinel structure by the Rietveld method using synchrotron powder X-ray diffraction data. Comparison of lattice constants suggested that Ni-substitution increased the covalency in the bonding of MO6 (M: metal ion at 16d site) octahedrals, but Ni/Ti co-substitution decreased the covalency of M-O bonds and introduced structural distortion. Electrical conductivity measurements by a four-probe method resulted in the determination that electrical conduction (within all samples) exhibits a nonadiabatic hopping process at high temperatures. The activation energies of Li1.05Mn2O4-δ and Li1.05Mn1.5Ni0.5O4-δ were found to be of similar values. The Ni/Ti co-substituted sample of Li1.05Mn1.0Ni0.5Ti0.5O4-δ, on the other hand, showed the highest activation energy among all the measured samples. Substitution reduced the electrical conductivity relative to Li1.05Mn2O4-δ; furthermore, both the substituted samples (Li1.05Mn1.5Ni0.5O4-δ and Li1.05Mn1.0Ni0.5Ti0.5O4-δ) were found to exhibit functional independence from oxygen partial pressure (PO2).

Impact of substituting added sugar in carbonated soft drinks by intense sweeteners in young adults in the Netherlands: example of a benefit-risk approach.

PubMed

Hendriksen, Marieke A; Tijhuis, Mariken J; Fransen, Heidi P; Verhagen, Hans; Hoekstra, Jeljer

2011-02-01

Substituting added sugar in carbonated soft drinks with intense sweeteners may have potential beneficial, but also adverse health effects. This study assessed the benefits and risks associated with substituting added sugar in carbonated soft drinks with intense sweeteners in young adults in the Netherlands. A tiered approach was used analogous to the risk assessment paradigm, consisting of benefit and hazard identification, exposure assessment and finally benefit and risk characterization and comparison. Two extreme scenarios were compared in which all carbonated soft drinks were sweetened with either intense sweeteners or added sugar. National food consumption survey data were used, and intake of added sugar and intense sweeteners was calculated using the food composition table or analytical data for sweetener content. Reduction in dental caries and body weight were identified as benefits of substituting sugar. The mean difference in total energy intake between the scenarios was 542 kJ per day in men and 357 kJ per day in women, under the assumption that no compensation takes place. In the 100% sweetener scenario, the average BMI decreased 1.7 kg/m(2) in men and 1.3 kg/m(2) in women when compared to the 100% sugar scenario. Risks are negligible, as the intake of intense sweeteners remains below the ADI in the substitution scenario. Substitution of added sugar by intense sweeteners in carbonated soft drinks has beneficial effects on BMI and the reduction in dental caries, and does not seem to have adverse health effects in young adults, given the available knowledge and assumptions made.

Interspecies protein substitution to investigate the role of the lyssavirus glycoprotein.

PubMed

Marston, Denise A; McElhinney, Lorraine M; Banyard, Ashley C; Horton, Daniel L; Núñez, Alejandro; Koser, Martin L; Schnell, Matthias J; Fooks, Anthony R

2013-02-01

European bat lyssaviruses type 1 (EBLV-1) and type 2 (EBLV-2) circulate within bat populations throughout Europe and are capable of causing disease indistinguishable from that caused by classical rabies virus (RABV). However, the determinants of viral fitness and pathogenicity are poorly understood. Full-length genome clones based on the highly attenuated, non-neuroinvasive, RABV vaccine strain (SAD-B19) were constructed with the glycoprotein (G) of either SAD-B19 (SN), of EBLV-1 (SN-1) or EBLV-2 (SN-2). In vitro characterization of SN-1 and SN-2 in comparison to wild-type EBLVs demonstrated that the substitution of G affected the final virus titre and antigenicity. In vivo, following peripheral infection with a high viral dose (10(4) f.f.u.), animals infected with SN-1 had reduced survivorship relative to infection with SN, resulting in survivorship similar to animals infected with EBLV-1. The histopathological changes and antigen distribution observed for SN-1 were more representative of those observed with SN than with EBLV-1. EBLV-2 was unable to achieve a titre equivalent to that of the other viruses. Therefore, a reduced-dose experiment (10(3) f.f.u.) was undertaken in vivo to compare EBLV-2 and SN-2, which resulted in 100 % survivorship for all recombinant viruses (SN, SN-1 and SN-2) while clinical disease developed in mice infected with the EBLVs. These data indicate that interspecies replacement of G has an effect on virus titre in vitro, probably as a result of suboptimal G-matrix protein interactions, and influences the survival outcome following a peripheral challenge with a high virus titre in mice.

Molecular characterization of infectious bursal disease virus isolates from Nepal based on hypervariable region of VP2 gene.

PubMed

Sharma, K; Hair-Bejo, M; Omar, A R; Aini, I

2005-01-01

Two Infectious bursal disease virus (IBDV) isolates, NP1SSH and NP2K were obtained from a severe infectious bursal disease (IBD) outbreak in Nepal in 2002. The hypervariable (HV) region of VP2 gene (1326 bp) of the isolates was generated by RT-PCR and sequenced. The obtained nucleotide sequences were compared with those of twenty other IBDV isolates/strains. Phylogenetic analysis based on this comparison revealed that NP1SSH and NP2K clustered with very virulent (vv) IBDV strains of serotype 1. In contrast, classical, Australian classical and attenuated strains of serotype 1 and avirulent IBDV strains of serotype 2 formed a different cluster. The deduced amino acid sequences of the two isolates showed a 98.3% identity with each other and 97.1% and 98.3% identities, respectively with very virulent IBDV (vvIBDV) isolates/strains. Three amino acids substitutions at positions 300 (E-->A), 308 (I-->F) and 334 (A-->P) within the HV region were common for both the isolates. The amino acids substitutions at positions 27 (S-->T), 28 (I-->T), 31 (D-->A), 36 (H-->Y), 135 (E-->G), 223 (G-->S), 225 (V-->I), 351 (L-->I), 352 (V-->E) and 399 (I-->S) for NP1SSH and at position 438 (I-->S) for NP2K were unique and differed from other IBDV isolates/strains. NP1SSH and NP2K showed highest similarity (97.8%) with the BD399 strain from Bangladesh as compared with other vvIBDV isolates/strains. We conclude that the NP1SSH and NP2K isolates of IBDV from Nepal represent vvIBDV of serotype 1.

An experimental and modeling study of the autoignition of 3-methylheptane

DOE PAGES

Wang, Weijing; Li, Zhenhua; Oehlschlaeger, Matthew A.; ...

2013-01-01

An experimental and kinetic modeling study of the autoignition of 3-methylheptane, a compound representative of the high molecular weight lightly branched alkanes found in large quantities in conventional and synthetic aviation kerosene and diesel fuels, is reported. Shock tube and rapid compression machine ignition delay time measurements are reported over a wide range of conditions of relevance to combustion engine applications: temperatures from 678 to 1356 K; pressures of 6.5, 10, 20, and 50 atm; and equivalence ratios of 0.5, 1.0, and 2.0. The wide range of temperatures examined provides observation of autoignition in three reactivity regimes, including the negativemore » temperature coefficient (NTC) regime characteristic of paraffinic fuels. Comparisons made between the current ignition delay measurements for 3-methylheptane and previous results for n-octane and 2-methylheptane quantifies the influence of a single methyl substitution and its location on the reactivity of alkanes. It is found that the three C8 alkane isomers have indistinguishable high-temperature ignition delay but their ignition delay times deviate in the NTC and low-temperature regimes in correlation with their research octane numbers. The experimental results are compared with the predictions of a proposed kinetic model that includes both high- and low-temperature oxidation chemistry. The model mechanistically explains the differences in reactivity for n-octane, 2-methylheptane, and 3-methylheptane in the NTC through the influence of the methyl substitution on the rates of isomerization reactions in the low-temperature chain branching pathway, that ultimately leads to ketohydroperoxide species, and the competition between low-temperature chain branching and the formation of cyclic ethers, in a chain propagating pathway.« less

[Sound improves distinction of low intensities of light in the visual cortex of a rabbit].

PubMed

Polianskiĭ, V B; Alymkulov, D E; Evtikhin, D V; Chernyshev, B V

2011-01-01

Electrodes were implanted into cranium above the primary visual cortex of four rabbits (Orictolagus cuniculus). At the first stage, visual evoked potentials (VEPs) were recorded in response to substitution of threshold visual stimuli (0.28 and 0.31 cd/m2). Then the sound (2000 Hz, 84 dB, duration 40 ms) was added simultaneously to every visual stimulus. Single sounds (without visual stimuli) did not produce a VEP-response. It was found that the amplitude ofVEP component N1 (85-110 ms) in response to complex stimuli (visual and sound) increased 1.6 times as compared to "simple" visual stimulation. At the second stage, paired substitutions of 8 different visual stimuli (range 0.38-20.2 cd/m2) by each other were performed. Sensory spaces of intensity were reconstructed on the basis of factor analysis. Sensory spaces of complexes were reconstructed in a similar way for simultaneous visual and sound stimulation. Comparison of vectors representing the stimuli in the spaces showed that the addition of a sound led to a 1.4-fold expansion of the space occupied by smaller intensities (0.28; 1.02; 3.05; 6.35 cd/m2). Also, the addition of the sound led to an arrangement of intensities in an ascending order. At the same time, the sound 1.33-times narrowed the space of larger intensities (8.48; 13.7; 16.8; 20.2 cd/m2). It is suggested that the addition of a sound improves a distinction of smaller intensities and impairs a dis- tinction of larger intensities. Sensory spaces revealed by complex stimuli were two-dimensional. This fact can be a consequence of integration of sound and light in a unified complex at simultaneous stimulation.

Identifying and Ordering Scalar Adjectives Using Lexical Substitution

ERIC Educational Resources Information Center

Wilkinson, Bryan

2017-01-01

Lexical semantics provide many important resources in natural language processing, despite the recent preferences for distributional methods. In this dissertation we investigate an under-represented lexical relationship, that of scalarity. We define scalarity as it relates to adjectives and introduce novel methods to identify words belonging to a…

20 CFR 408.802 - When will we suspend your SVB payments?

Code of Federal Regulations, 2010 CFR

2010-04-01

....802 Section 408.802 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Suspensions and Terminations Suspension § 408.802 When will we suspend your SVB... underway for a substitute representative payee.) (b) Effect of suspension. When we correctly suspend your...

Charged dopants in neutral supercells through substitutional donor (acceptor): nitrogen donor charging of the nitrogen-vacancy center in diamond

NASA Astrophysics Data System (ADS)

Löfgren, Robin; Pawar, Ravinder; Öberg, Sven; Larsson, J. Andreas

2018-02-01

Charged defects are traditionally computed by adding (subtracting) electrons for negative (positive) impurities. When using periodic boundary conditions this results in artificially charged supercells that also require a compensating background charge of the opposite sign, which makes slab supercells problematic because of an arbitrary dependence on the vacuum thickness. In this work, we test the method of using neutral supercells through the use of a substitutional electron donor (acceptor) to describe charged systems. We use density functional theory (DFT) to compare the effects of charging the well-studied NV-center in diamond by a substitutional donor nitrogen. We investigate the influence of the donor-N on the NV-center properties as a function of the distance between them, and find that they converge toward those obtained when adding an electron. We analyze the spin density and conclude that the donor-N has a zero magnetic moment, and thus, will not be seen in electron spin resonance. We validate our DFT energies through comparison to GW simulations. Charging the NV-center with a substitutional donor-N enables accurate calculations of slabs, without the ambiguity of using charged supercells. Implantation of donor-N atoms opens up the possibility to engineer NV-centers with the desired charge state for future ICT and sensor applications.

Effect of heat moisture treatment (HMT) on product quality of sorghum starch

NASA Astrophysics Data System (ADS)

Haryani, Kristinah; Hadiyanto, Handayani, Noera; Nugraheni, Dwi; Suryanto

2015-12-01

Sorghum is a cereal plant that rich of nutrition contents. The high content of carbohydrate in sorghum make this plant can be processed into one of the processed food i.e vermicelli. To give better quality, it is necessary to use flour substitution from sorghum starch. The aim of this study was to evaluate the treatment of natural sorghum starch substitution, the addition of CMC, and a comparison of the natural starch with starch sorghum forage sorghum against solid losses value, rehydration weight and texture profiles. The variable used in this study: amount of natural sorghum starch subtituion (10%, 20%, 30%, 40%, 50%), the addition of CMC (0.1%; 0.2%; 0.3%; 0.4%; 0.5%) and substituting sorghum starch Natural: HMT sorghum starch (1: 1; 1: 2; 1: 3; 1: 4; 1: 5) and the quality parameters were evaluated. The result indicated that to substitute sorghum starch naturally at a rate of 50% had the best results with a value of solid losses 5.1% (white sorghum) 5.83% (red sorghum) and weighing rehydration 301.82% (white sorghums) 293.16% (red sorghum), the addition of CMC with 0.5% concentration of 3.96% solid losses value (red sorghum) 4:21% (white sorghums) and weight rehydration 252.71% (white sorghums) 244.45% (red sorghums).

Influence of Avocado Purée as a Fat Replacer on Nutritional, Fatty Acid, and Organoleptic Properties of Low-Fat Muffins.

PubMed

Othman, Nurul Ain; Abdul Manaf, Marina; Harith, Sakinah; Wan Ishak, Wan Rosli

2018-04-13

The feasibility of developing reduced-fat muffins with avocado is investigated by preparing muffins with 25%, 50%, 75%, and 100% avocado purée as a fat (butter) replacer. The resulting products were compared to the control muffin, which was made with 100% butter. Muffins were analyzed for nutritional content, fatty acid profiles, and sensory acceptability. Muffins incorporated with avocado purée revealed a significant increase (p < 0.05) with respect to moisture, ash, and carbohydrate in comparison with the control sample. However, no significant changes (p > 0.05) were detected in all muffin formulations for protein and dietary fiber content. Both fat content and caloric value of muffins incorporated with avocado purée were significantly decreased (p < 0.05). The fatty acid profile showed that there was an increment in the monounsaturated fatty acids (MUFA) content by 16.51% at full-fat substitution. The sensory evaluation test demonstrated that muffins had acceptability at up to 50% substitution. Fat substitution at higher than 50% lead to undesirable flavor and aftertaste, which was significant (p < 0.05) to the panelists. The findings indicated the feasibility of avocado purée in fat-reduced muffin preparation with an optimal level of 50% avocado purée substitution.

Candida potacharoeniae sp. nov. and Candida spenceri sp. nov., two novel galactose-containing ascomycetous anamorphic yeast species isolated in Thailand.

PubMed

Nakase, Takashi; Jindamorakot, Sasitorn; Imanishi, Yumi; Am-In, Somjit; Ninomiya, Shinya; Kawasaki, Hiroko; Limtong, Savitree

2010-08-01

Fifteen strains of anamorphic yeasts isolated from various natural substrates collected in various places in Thailand were found to represent two novel species of anamorphic yeast genus Candida based on the sequence analysis of the D1/D2 domain of the large subunit rRNA genes, chemotaxonomic and conventional properties used for the classification of yeasts. These strains are located in the clade including Candida etchellsii and Candida magnoliae. Fourteen strains represented by ST-490(T) (BCC 15176(T)=NBRC 106439(T)= CBS 11674(T)) are closely related to Candida sorbosivorans in the D1/D2 sequences but 11 nucleotides (2.4%) were substituted. The remaining strain, ST-594(T) (=BCC 15278(T)=NBRC 106446(T)=CBS 11673(T)) showed a close relationship to Candida geochares but 21 nucleotides (4.7%) were substituted. Apparently, these strains represent two novel Candida species of the Starmerella clade. The two species are described as Candida potacharoeniae sp. nov. and Candida spenceri sp. nov. in the present paper. Like the most species of this clade, the two species contain galactose in the cells in addition to glucose and mannose and have high mol% G + C of 54.4-55.9 and 54.9, respectively.

An integrated system for identifying the hidden assassins in traditional medicines containing aristolochic acids

NASA Astrophysics Data System (ADS)

Wu, Lan; Sun, Wei; Wang, Bo; Zhao, Haiyu; Li, Yaoli; Cai, Shaoqing; Xiang, Li; Zhu, Yingjie; Yao, Hui; Song, Jingyuan; Cheng, Yung-Chi; Chen, Shilin

2015-08-01

Traditional herbal medicines adulterated and contaminated with plant materials from the Aristolochiaceae family, which contain aristolochic acids (AAs), cause aristolochic acid nephropathy. Approximately 256 traditional Chinese patent medicines, containing Aristolochiaceous materials, are still being sold in Chinese markets today. In order to protect consumers from health risks due to AAs, the hidden assassins, efficient methods to differentiate Aristolochiaceous herbs from their putative substitutes need to be established. In this study, 158 Aristolochiaceous samples representing 46 species and four genera as well as 131 non-Aristolochiaceous samples representing 33 species, 20 genera and 12 families were analyzed using DNA barcodes based on the ITS2 and psbA-trnH sequences. Aristolochiaceous materials and their non-Aristolochiaceous substitutes were successfully identified using BLAST1, the nearest distance method and the neighbor-joining (NJ) tree. In addition, based on sequence information of ITS2, we developed a Real-Time PCR assay which successfully identified herbal material from the Aristolochiaceae family. Using Ultra High Performance Liquid Chromatography-Mass Spectrometer (UHPLC-HR-MS), we demonstrated that most representatives from the Aristolochiaceae family contain toxic AAs. Therefore, integrated DNA barcodes, Real-Time PCR assays using TaqMan probes and UHPLC-HR-MS system provides an efficient and reliable authentication system to protect consumers from health risks due to the hidden assassins (AAs).

Marketing of breast-milk substitutes in Zambia: evaluation of compliance to the international regulatory code.

PubMed

Funduluka, P; Bosomprah, S; Chilengi, R; Mugode, R H; Bwembya, P A; Mudenda, B

2018-03-01

We sought to assess the level of non-compliance with the International Code of Marketing breast-milk substitutes (BMS) and/or Statutory Instrument (SI) Number 48 of 2006 of the Laws of Zambia in two suburbs, Kalingalinga and Chelstone, in Zambia. This was a cross sectional survey. Shop owners (80), health workers (8) and mothers (214) were interviewed. BMS labels and advertisements (62) were observed. The primary outcome was mean non-compliance defined as the number of article violations divided by the total 'obtainable' violations. The score ranges from 0 to 1 with 0 representing no violations in all the articles and one representing violations in all the articles. A total of 62 BMS were assessed. The mean non-compliance score by manufacturers in terms of violations in labelling of BMS was 0.33 (SD = 0.28; 95% CI: 0.26, 0.40). These violations were mainly due to labels containing pictures or graphics representing an infant. 80 shops were also assessed with mean non-compliance score in respect of violations in tie-in-sales, special display, and contact with mothers at the shop estimated as 0.14 (SD = 0.14; 95% CI: 0.11, 0.18). Non-compliance with the Code and/or the local SI is high after 10 years of domesticating the Code.

Genomic resources for Myzus persicae: EST sequencing, SNP identification, and microarray design

PubMed Central

Ramsey, John S; Wilson, Alex CC; de Vos, Martin; Sun, Qi; Tamborindeguy, Cecilia; Winfield, Agnese; Malloch, Gaynor; Smith, Dawn M; Fenton, Brian; Gray, Stewart M; Jander, Georg

2007-01-01

Background The green peach aphid, Myzus persicae (Sulzer), is a world-wide insect pest capable of infesting more than 40 plant families, including many crop species. However, despite the significant damage inflicted by M. persicae in agricultural systems through direct feeding damage and by its ability to transmit plant viruses, limited genomic information is available for this species. Results Sequencing of 16 M. persicae cDNA libraries generated 26,669 expressed sequence tags (ESTs). Aphids for library construction were raised on Arabidopsis thaliana, Nicotiana benthamiana, Brassica oleracea, B. napus, and Physalis floridana (with and without Potato leafroll virus infection). The M. persicae cDNA libraries include ones made from sexual and asexual whole aphids, guts, heads, and salivary glands. In silico comparison of cDNA libraries identified aphid genes with tissue-specific expression patterns, and gene expression that is induced by feeding on Nicotiana benthamiana. Furthermore, 2423 genes that are novel to science and potentially aphid-specific were identified. Comparison of cDNA data from three aphid lineages identified single nucleotide polymorphisms that can be used as genetic markers and, in some cases, may represent functional differences in the protein products. In particular, non-conservative amino acid substitutions in a highly expressed gut protease may be of adaptive significance for M. persicae feeding on different host plants. The Agilent eArray platform was used to design an M. persicae oligonucleotide microarray representing over 10,000 unique genes. Conclusion New genomic resources have been developed for M. persicae, an agriculturally important insect pest. These include previously unknown sequence data, a collection of expressed genes, molecular markers, and a DNA microarray that can be used to study aphid gene expression. These resources will help elucidate the adaptations that allow M. persicae to develop compatible interactions with its host plants, complementing ongoing work illuminating plant molecular responses to phloem-feeding insects. PMID:18021414

A comparison of somatic mutational spectra in healthy study populations from Russia, Sweden and USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noori, P; Hou, S; Jones, I M

Comparison of mutation spectra at the hypoxanthine-phosphoribosyl transferase (HPRT) gene of peripheral blood T lymphocytes may provide insight into the aetiology of somatic mutation contributing to carcinogenesis and other diseases. To increase knowledge of mutation spectra in healthy people, we have analyzed HPRT mutant T-cells of 50 healthy Russians originally recruited as controls for a study of Chernobyl clean-up workers (Jones et al. Radiation Res. 158, 2002, 424). Reverse transcriptase polymerase chain reactions and DNA sequencing identified 161 independent mutations among 176 thioguanine resistant mutants. Forty (40) mutations affected splicing mechanisms and 27 deletions or insertions of 1 to 60more » nucleotides were identified. Ninety four (94) single base substitutions were identified, including 62 different mutations at 55 different nucleotide positions, of which 19 had not previously been reported in human T-cells. Comparison of this base substitution spectrum with mutation spectra in a USA (Burkhart-Schultz et al. Carcinogenesis 17, 1996, 1871) and two Swedish populations (Podlutsky et al, Carcinogenesis 19, 1998, 557, Podlutsky et al. Mutation Res. 431, 1999, 325) revealed similarity in the type, frequency and distribution of mutations in the four spectra, consistent with aetiologies inherent in human metabolism. There were 15-19 identical mutations in the three pair-wise comparisons of Russian with USA and Swedish spectra. Intriguingly, there were 21 mutations unique to the Russian spectrum, and comparison by the Monte Carlo method of Adams and Skopek (J. Mol. Biol. 194, 1987, 391) indicated that the Russian spectrum was different from both Swedish spectra (P=0.007, 0.002) but not different from the USA spectrum (P=0.07), when Bonferroni correction for multiple comparisons was made (p < 0.008 required for significance). Age and smoking did not account for these differences. Other factors causing mutational differences need to be explored.« less

Energetics of Single Substitutional Impurities in NiTi

NASA Technical Reports Server (NTRS)

Good, Brian S.; Noebe, Ronald

2003-01-01

Shape-memory alloys are of considerable current interest, with applications ranging from stents to Mars rover components. In this work, we present results on the energetics of single substitutional impurities in B2 NiTi. Specifically, energies of Pd, Pt, Zr and Hf impurities at both Ni and Ti sites are computed. All energies are computed using the CASTEP ab initio code, and, for comparison, using the quantum approximate energy method of Bozzolo, Ferrante and Smith. Atomistic relaxation in the vicinity of the impurities is investigated via quantum approximate Monte Carlo simulation, and in cases where the relaxation is found to be important, the resulting relaxations are applied to the ab initio calculations. We compare our results with available experimental work.

Diffusion of anthracene derivatives on Cu(111) studied by STM and DFT

NASA Astrophysics Data System (ADS)

Wyrick, Jonathan; Bartels, Ludwig; Einstein, Theodore

2014-03-01

Substituted anthracenes have drawn attention due to their ability to diffuse uniaxially on a Cu(111) surface. We compare anthracene to three of its derivatives whose 9,10 hydrogens are replaced by elements of the chalcogen group that act as linkers binding the molecules to a Cu(111) substrate. DFT calculations shed light on STM imaging and diffusion studies on the three substituted species. We present an analysis of the DFT results in which energetic contributions to the diffusion barriers are partitioned among the Kohn-Sham orbitals, allowing us to make assignments as to how each orbital affects diffusion for each species and draw comparisons between them. Present address: Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD.

The Comprehension of Rapid Speech by the Blind: Part III. Final Report.

ERIC Educational Resources Information Center

Foulke, Emerson

Accounts of completed and ongoing research conducted from 1964 to 1968 are presented on the subject of accelerated speech as a substitute for the written word. Included are a review of the research on intelligibility and comprehension of accelerated speech, some methods for controlling the word rate of recorded speech, and a comparison of…

Uses and Gratifications of Social Media: A Comparison of Facebook and Instant Messaging

ERIC Educational Resources Information Center

Quan-Haase, Anabel; Young, Alyson L.

2010-01-01

Users have adopted a wide range of digital technologies into their communication repertoire. It remains unclear why they adopt multiple forms of communication instead of substituting one medium for another. It also raises the question: What type of need does each of these media fulfill? In the present article, the authors conduct comparative work…

Development of Reliable and Valid Short Forms of the Marlowe-Crowne Social Desirability Scale.

ERIC Educational Resources Information Center

Reynolds, William M.

1982-01-01

Developed, on the basis of responses from 608 undergraduate students to the 33-item Marlowe-Crowne Social Desirability Scale, three short forms of the scale. Comparisons made between the short forms examined in this investigation suggest the 13-item form as a viable substitute for the regular 33-item Marlowe-Crowne scale. (Author)

Comparison of insect vacuums for sampling Asian citrus psyllid (Homoptera: Psyllidae) on citrus trees

USDA-ARS?s Scientific Manuscript database

Three vacuum devices were compared for sampling psyllid populations. One was an AC rechargeable, handheld, cordless model and a second was a handheld, DC model powered through a cord connected to a 12V vehicle battery. Each of these devices had a mesh cylinder (substituted for a dust bag) in which...

The Oxidation of Ascorbic Acid by Hexacyanoferrate(III) Ion in Acidic Aqueous Media.

ERIC Educational Resources Information Center

Martins, Luis J. A.; da Costa, J. Barbosa

1988-01-01

Describes a kinetic and mechanistic investigation of ascorbic acid by a substitution-inert complex in acidic medium suitable for the undergraduate level. Discusses obtaining the second order rate constant for the rate determining step at a given temperature and comparison with the value predicted on the basis of the Marcus cross-relation. (CW)

Biodegradation of chloro- and bromobenzoic acids: effect of milieu conditions and microbial community analysis.

PubMed

Gaza, Sarah; Felgner, Annika; Otto, Johannes; Kushmaro, Ariel; Ben-Dov, Eitan; Tiehm, Andreas

2015-04-28

Monohalogenated benzoic acids often appear in industrial wastewaters where biodegradation can be hampered by complex mixtures of pollutants and prevailing extreme milieu conditions. In this study, the biodegradation of chlorinated and brominated benzoic acids was conducted at a pH range of 5.0-9.0, at elevated salt concentrations and with pollutant mixtures including fluorinated and iodinated compounds. In mixtures of the isomers, the degradation order was primarily 4-substituted followed by 3-substituted and then 2-substituted halogenated benzoic acids. If the pH and salt concentration were altered simultaneously, long adaptation periods were required. Community analyses were conducted in liquid batch cultures and after immobilization on sand columns. The Alphaproteobacteria represented an important fraction in all of the enrichment cultures. On the genus level, Afipia sp. was detected most frequently. In particular, Bacteroidetes were detected in high numbers with chlorinated benzoic acids. Copyright © 2015 Elsevier B.V. All rights reserved.

Electronic characterization of defects in narrow gap semiconductors

NASA Technical Reports Server (NTRS)

Patterson, James D.

1993-01-01

The study of point defects in semiconductors has a long and honorable history. In particular, the detailed understanding of shallow defects in common semiconductors traces back to the classic work of Kohn and Luttinger. However, the study of defects in narrow gap semiconductors represents a much less clear story. Here, both shallow defects (caused by long range potentials) and deep defects (from short range potentials) are far from being completely understood. In this study, all results are calculational and our focus is on the chemical trend of deep levels in narrow gap semiconductors. We study substitutional (including antisite), interstitial and ideal vacancy defects. For substitutional and interstitial impurities, the efects of relaxation are included. For materials like Hg(1-x)Cd(x)Te, we study how the deep levels vary with x, of particular interest is what substitutional and interstitial atoms yield energy levels in the gap i.e. actually produce deep ionized levels. Also, since the main technique utilized is Green's functions, we include some summary of that method.

Selectivity in the Addition Reactions of Organometallic Reagents to Aziridine-2-carboxaldehydes: The Effects of Protecting Groups and Substitution Patterns

PubMed Central

Kulshrestha, Aman; Schomaker, Jennifer M.; Holmes, Daniel; Staples, Richard J.; Jackson, James E.; Borhan, Babak

2014-01-01

Good to excellent stereo-selectivity has been found in the addition reactions of Grignard and organo-zinc reagents to N-protected aziridine-2-carboxaldehydes. Specifically, high syn selectivity was obtained with benzyl-protected cis, tert-butyloxycar-bonyl-protected trans, and tosyl-pro-tected 2,3-disubstituted aziridine-2-car-boxaldehydes. Furthermore, rate and selectivity effects of ring substituents, temperature, solvent, and Lewis acid and base modifiers were studied. The diastereomeric preference of addition is dominated by the substrate aziri-dines’ substitution pattern and especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6–31G* level of theory with the SM8 solvation model to account for solvent effects. PMID:21928447

New alloys to conserve critical elements. [replacing chromium in steels

NASA Technical Reports Server (NTRS)

Stephens, J. R.

1978-01-01

Previous studies and surveys on availability of domestic reserves have shown that chromium is a most critical element within the U.S. metal industry. More precisely, the bulk of chromium is consumed in the production of stainless steels, specifically Type 304 stainless steel (304SS) which contains 18% Cr. The present paper deals with means of reducing chromium in commercial stainless steels by substituting more abundant or less expensive elements with the intent of maintaining the properties of 304SS. The discussion focuses on some of the oxidation and corrosion properties of new substitute stainless steels with only 12% Cr, which represents a potential saving of 33% of the chromium consumed in the production of 304SS. The alloying elements substituted for Cr in 304SS are selected according to their potential for protective oxide formation during high-temperature oxidation; these are Al, Si, Ti, Y, and misch metal which is 99.7% rare-earth metals containing 50 to 55% cerium. Other alloying elements to impart corrosion resistance are Mn, Mo, and V.

Memory-Based Simple Heuristics as Attribute Substitution: Competitive Tests of Binary Choice Inference Models.

PubMed

Honda, Hidehito; Matsuka, Toshihiko; Ueda, Kazuhiro

2017-05-01

Some researchers on binary choice inference have argued that people make inferences based on simple heuristics, such as recognition, fluency, or familiarity. Others have argued that people make inferences based on available knowledge. To examine the boundary between heuristic and knowledge usage, we examine binary choice inference processes in terms of attribute substitution in heuristic use (Kahneman & Frederick, 2005). In this framework, it is predicted that people will rely on heuristic or knowledge-based inference depending on the subjective difficulty of the inference task. We conducted competitive tests of binary choice inference models representing simple heuristics (fluency and familiarity heuristics) and knowledge-based inference models. We found that a simple heuristic model (especially a familiarity heuristic model) explained inference patterns for subjectively difficult inference tasks, and that a knowledge-based inference model explained subjectively easy inference tasks. These results were consistent with the predictions of the attribute substitution framework. Issues on usage of simple heuristics and psychological processes are discussed. Copyright © 2016 Cognitive Science Society, Inc.

A framework for assessing supply-side wildlife conservation.

PubMed

Phelps, J; Carrasco, L R; Webb, E L

2014-02-01

Market-based, supply-side interventions such as domestication, cultivation, and wildlife farming have been proposed as legal substitutes for wild-collected plants and animals in the marketplace. Based on the literature, we devised a list of the conditions under which supply-side interventions may yield positive conservation outcomes. We applied it to the trade of the orchid Rhynchostylis gigantea, a protected ornamental plant. We conducted a survey of R. gigantea at Jatujak Market in Bangkok, Thailand. Farmed (legal) and wild (illegal, protected) specimens of R. gigantea were sold side-by-side at market. These results suggest farmed specimens are not being substituted for wild plants in the marketplace. For any given set of physical plant characteristics (size, condition, flowers), the origin of the plants (wild vs. farmed) did not affect price. For all price classes, farmed plants were of superior quality to wild-collected plants on the basis of most physical variables. These results suggest wild and farmed specimens represent parallel markets and may not be substitutable goods. Our results with R. gigantea highlight a range of explanations for why supply-side interventions may lack effectiveness, for example, consumer preferences for wild-collected products and low financial incentives for farming. Our results suggest that market-based conservation strategies may not be effective by themselves and may be best utilized as supplements to regulation and education. This approach represents a broad, multidisciplinary evaluation of supply-side interventions that can be applied to other plant and animal species. © 2013 Society for Conservation Biology.

Prototypical Recombinant Multi-Protease-Inhibitor-Resistant Infectious Molecular Clones of Human Immunodeficiency Virus Type 1

PubMed Central

Varghese, Vici; Mitsuya, Yumi; Fessel, W. Jeffrey; Liu, Tommy F.; Melikian, George L.; Katzenstein, David A.; Schiffer, Celia A.; Holmes, Susan P.

2013-01-01

The many genetic manifestations of HIV-1 protease inhibitor (PI) resistance present challenges to research into the mechanisms of PI resistance and the assessment of new PIs. To address these challenges, we created a panel of recombinant multi-PI-resistant infectious molecular clones designed to represent the spectrum of clinically relevant multi-PI-resistant viruses. To assess the representativeness of this panel, we examined the sequences of the panel's viruses in the context of a correlation network of PI resistance amino acid substitutions in sequences from more than 10,000 patients. The panel of recombinant infectious molecular clones comprised 29 of 41 study-defined PI resistance amino acid substitutions and 23 of the 27 tightest amino acid substitution clusters. Based on their phenotypic properties, the clones were classified into four groups with increasing cross-resistance to the PIs most commonly used for salvage therapy: lopinavir (LPV), tipranavir (TPV), and darunavir (DRV). The panel of recombinant infectious molecular clones has been made available without restriction through the NIH AIDS Research and Reference Reagent Program. The public availability of the panel makes it possible to compare the inhibitory activities of different PIs with one another. The diversity of the panel and the high-level PI resistance of its clones suggest that investigational PIs active against the clones in this panel will retain antiviral activity against most if not all clinically relevant PI-resistant viruses. PMID:23796938

Synthesis and characterization of a 1D chain-like Cu{sub 6} substituted sandwich-type phosphotungstate with pendant dinuclear Cu–azido complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yan-Ying; Zhao, Jun-Wei, E-mail: zhaojunwei@henu.edu.cn; Wei, Qi

A novel Cu–azido complex modified hexa-Cu{sup II} substituted sandwich-type phosphotungstate [Cu(en){sub 2}]([Cu{sub 2}(en){sub 2}(μ-1,1-N{sub 3}){sub 2}(H{sub 2}O)]{sub 2}[Cu{sub 6}(en){sub 2}(H{sub 2}O){sub 2}(B-α-PW{sub 9}O{sub 34}){sub 2}])·6H{sub 2}O (1) (en=ethylene-diamine) has been prepared under hydrothermal conditions and structurally characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1 displays a beautiful 1-D chain architecture constructed from sandwich-type [Cu{sub 2}(en){sub 2}(μ-1,1-N{sub 3}){sub 2}(H{sub 2}O)]{sub 2}[Cu{sub 6}(en){sub 2}(H{sub 2}O){sub 2}(B-α-PW{sub 9}O{sub 34}){sub 2}]{sup 2−} units and [Cu(en){sub 2}]{sup 2+} linkers. To our knowledge, 1 represents the first hexa-Cu{sup II} sandwiched phosphotungstate with supporting Cu–azido complexes. - Graphical abstract: Themore » first hexa-Cu{sup II} sandwiched phosphotungstate with supporting Cu–azido complexes has been prepared and characterized. Display Omitted - Highlights: • Hexa-copper-substituted phosphotungstate. • Cu–azido complexes modified hexa-Cu{sup II} substituted sandwich-type polyoxometalate. • 1-D chain architecture built by hexa-copper-substituted polyoxotungstate units.« less

Saccharin Aza Bioisosteres-Synthesis and Preclinical Property Comparisons.

PubMed

Chen, Yantao; Aurell, Carl-Johan; Pettersen, Anna; Lewis, Richard J; Hayes, Martin A; Lepistö, Matti; Jonson, Anna C; Leek, Hanna; Thunberg, Linda

2017-06-08

Saccharin is a well-known scaffold in drug discovery. Herein, we report the synthesis and preclinical property comparisons of three bioisosteres of saccharin: aza-pseudosaccharins (cluster B ), and two new types of aza-saccharins (clusters C and D ). We demonstrate a convenient protocol to selectively synthesize products in cluster C or D when primary amines are used. Preclinical characterization of selected matched-pair products is reported. Through comparison of two diastereomers, we highlight how stereochemistry affects the preclinical properties. Given that saccharin-based derivatives are widely used in many chemistry fields, we foresee that structures exemplified by clusters C and D offer new opportunities for novel drug design, creating a chiral center on the sulfur atom and the option of substitution at two different nitrogens.

Evaluation of outgassing, tear strength, and detail reproduction in alginate substitute materials.

PubMed

Baxter, R T; Lawson, N C; Cakir, D; Beck, P; Ramp, L C; Burgess, J O

2012-01-01

To compare three alginate substitute materials to an alginate impression material for cast surface porosity (outgassing), tear strength, and detail reproduction. Detail reproduction tests were performed following American National Standards Institute/American Dental Association (ANSI/ADA) Specification No. 19. To measure tear strength, 12 samples of each material were made using a split mold, placed in a water bath until testing, and loaded in tension until failure at a rate of 500 mm/min using a universal testing machine. For cast surface porosity testing, five impressions of a Teflon mold with each material were placed in a water bath (37.8°C) for the in-mouth setting time and poured with vacuum-mixed Silky Rock die stone at 5, 10, 30, and 60 minutes from the start of mixing. The gypsum samples were analyzed with a digital microscope for surface porosity indicative of hydrogen gas release by comparing the surface obtained at each interval with four casts representing no, little, some, and significant porosity. Data analysis was performed using parametric and Kruskal-Wallis analysis of variance (ANOVA), Tukey/Kramer post-hoc tests (α=0.05), and individual Mann-Whitney U tests (α=0.0167). All alginate substitute materials passed the detail reproduction test. Tear strength of the alginate substitute materials was significantly better than alginate and formed three statistically different groups: AlgiNot had the lowest tear strength, Algin-X Ultra had the highest tear strength, and Position Penta Quick had intermediate tear strength. Significant variation in outgassing existed between materials and pouring times (p<0.05). All alginate substitute materials exhibited the least outgassing and cast porosity 60 minutes after mixing. Detail reproduction and tear strength of alginate substitute materials were superior to traditional alginate. The outgassing effect was minimal for most materials tested. Alginate substitute materials are superior replacements for irreversible hydrocolloid.

40 CFR 790.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... substance or mixture is able to represent or substitute for another in a test or series of tests, and that... submitted to EPA and ends after an amount of time equal to that which had been required to develop data or after five years, whichever is later. Sponsor means the person or persons who design, direct and finance...

40 CFR 790.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... represent or substitute for another in a test or series of tests, and that the data from one substance can... and ends after an amount of time equal to that which had been required to develop data or after five years, whichever is later. Sponsor means the person or persons who design, direct and finance the...

40 CFR 790.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... substance or mixture is able to represent or substitute for another in a test or series of tests, and that... submitted to EPA and ends after an amount of time equal to that which had been required to develop data or after five years, whichever is later. Sponsor means the person or persons who design, direct and finance...

40 CFR 790.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... substance or mixture is able to represent or substitute for another in a test or series of tests, and that... submitted to EPA and ends after an amount of time equal to that which had been required to develop data or after five years, whichever is later. Sponsor means the person or persons who design, direct and finance...

Students' Multi-Modal Re-Presentations of Scientific Knowledge and Creativity

ERIC Educational Resources Information Center

Koren, Yitzhak; Klavir, Rama; Gorodetsky, Malka

2005-01-01

The paper brings the results of a project that passed on to students the opportunity for re-presenting their acquired knowledge via the construction of multi-modal "learning resources". These "learning resources" substituted for lectures and books and became the official learning sources in the classroom. The rational for the…

Modern Amphibious Operations: Why the United States Must Maintain a Joint Amphibious Forcible Entry Capability

DTIC Science & Technology

2012-03-23

be reminded that the aforementioned movies depicted events that happened nearly 70 years ago.48 These films neither represent modem amphibious...contemporary sources. Few are more contemporary than those in this genre . Nothing can substitute a simple Google web search to get ideas about where

A low-complexity add-on score for protein remote homology search with COMER.

PubMed

Margelevicius, Mindaugas

2018-06-15

Protein sequence alignment forms the basis for comparative modeling, the most reliable approach to protein structure prediction, among many other applications. Alignment between sequence families, or profile-profile alignment, represents one of the most, if not the most, sensitive means for homology detection but still necessitates improvement. We aim at improving the quality of profile-profile alignments and the sensitivity induced by them by refining profile-profile substitution scores. We have developed a new score that represents an additional component of profile-profile substitution scores. A comprehensive evaluation shows that the new add-on score statistically significantly improves both the sensitivity and the alignment quality of the COMER method. We discuss why the score leads to the improvement and its almost optimal computational complexity that makes it easily implementable in any profile-profile alignment method. An implementation of the add-on score in the open-source COMER software and data are available at https://sourceforge.net/projects/comer. The COMER software is also available on Github at https://github.com/minmarg/comer and as a Docker image (minmar/comer). Supplementary data are available at Bioinformatics online.

Changing selective pressure during antigenic changes in human influenza H3.

PubMed

Blackburne, Benjamin P; Hay, Alan J; Goldstein, Richard A

2008-05-02

The rapid evolution of influenza viruses presents difficulties in maintaining the optimal efficiency of vaccines. Amino acid substitutions result in antigenic drift, a process whereby antisera raised in response to one virus have reduced effectiveness against future viruses. Interestingly, while amino acid substitutions occur at a relatively constant rate, the antigenic properties of H3 move in a discontinuous, step-wise manner. It is not clear why this punctuated evolution occurs, whether this represents simply the fact that some substitutions affect these properties more than others, or if this is indicative of a changing relationship between the virus and the host. In addition, the role of changing glycosylation of the haemagglutinin in these shifts in antigenic properties is unknown. We analysed the antigenic drift of HA1 from human influenza H3 using a model of sequence change that allows for variation in selective pressure at different locations in the sequence, as well as at different parts of the phylogenetic tree. We detect significant changes in selective pressure that occur preferentially during major changes in antigenic properties. Despite the large increase in glycosylation during the past 40 years, changes in glycosylation did not correlate either with changes in antigenic properties or with significantly more rapid changes in selective pressure. The locations that undergo changes in selective pressure are largely in places undergoing adaptive evolution, in antigenic locations, and in locations or near locations undergoing substitutions that characterise the change in antigenicity of the virus. Our results suggest that the relationship of the virus to the host changes with time, with the shifts in antigenic properties representing changes in this relationship. This suggests that the virus and host immune system are evolving different methods to counter each other. While we are able to characterise the rapid increase in glycosylation of the haemagglutinin during time in human influenza H3, an increase not present in influenza in birds, this increase seems unrelated to the observed changes in antigenic properties.

The substitutability of cigarettes and food: A behavioral economic comparison in normal weight and overweight or obese smokers.

PubMed

Murphy, Cara M; Owens, Max M; Sweet, Lawrence H; MacKillop, James

2016-12-01

Obesity and cigarette smoking contribute to a multitude of preventable deaths in the United States and eating and smoking behavior may influence each other. The field of behavioral economics integrates principles from psychology and economics and permits systematic examination of how commodities interrelate with one another. Using this framework, the current study evaluated the effects of rising food and cigarette prices on consumption to investigate their substitutability and their relationship to BMI and associated variables. Behavioral economics categorizes commodities as substitutable when the consumption of one increases as a function of a price increase in the other. Smokers (N = 86) completed a 2-part hypothetical task in which money was allocated to purchase cigarettes and fast-food-style reinforcers (e.g., hamburgers, ice cream) at various prices. Results indicated that food and cigarettes were not substitutes for one another (cross-price elasticity coefficients < .20). Food purchases were independent of cigarette price, whereas cigarette purchases decreased as food price rose. Cross-price elasticity coefficients were significantly associated with confidence in one's ability to control weight without smoking (rs = -.23 and .29), but not BMI (rs = .04 and .04) or postcessation weight concerns (rs = -.05 and .12). Perceived ability to manage weight without cigarettes may influence who substitutes food for cigarettes when quitting. In addition, given observed decreases in purchases of both commodities as food prices increased, these findings imply that greater taxation of fast-food-style reinforcers could potentially reduce consumption of these foods and also cigarettes among smokers. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Human Lineage-Specific Transcriptional Regulation through GA-Binding Protein Transcription Factor Alpha (GABPa)

PubMed Central

Perdomo-Sabogal, Alvaro; Nowick, Katja; Piccini, Ilaria; Sudbrak, Ralf; Lehrach, Hans; Yaspo, Marie-Laure; Warnatz, Hans-Jörg; Querfurth, Robert

2016-01-01

A substantial fraction of phenotypic differences between closely related species are likely caused by differences in gene regulation. While this has already been postulated over 30 years ago, only few examples of evolutionary changes in gene regulation have been verified. Here, we identified and investigated binding sites of the transcription factor GA-binding protein alpha (GABPa) aiming to discover cis-regulatory adaptations on the human lineage. By performing chromatin immunoprecipitation-sequencing experiments in a human cell line, we found 11,619 putative GABPa binding sites. Through sequence comparisons of the human GABPa binding regions with orthologous sequences from 34 mammals, we identified substitutions that have resulted in 224 putative human-specific GABPa binding sites. To experimentally assess the transcriptional impact of those substitutions, we selected four promoters for promoter-reporter gene assays using human and African green monkey cells. We compared the activities of wild-type promoters to mutated forms, where we have introduced one or more substitutions to mimic the ancestral state devoid of the GABPa consensus binding sequence. Similarly, we introduced the human-specific substitutions into chimpanzee and macaque promoter backgrounds. Our results demonstrate that the identified substitutions are functional, both in human and nonhuman promoters. In addition, we performed GABPa knock-down experiments and found 1,215 genes as strong candidates for primary targets. Further analyses of our data sets link GABPa to cognitive disorders, diabetes, KRAB zinc finger (KRAB-ZNF), and human-specific genes. Thus, we propose that differences in GABPa binding sites played important roles in the evolution of human-specific phenotypes. PMID:26814189

Determinants of Base-Pair Substitution Patterns Revealed by Whole-Genome Sequencing of DNA Mismatch Repair Defective Escherichia coli.

PubMed

Foster, Patricia L; Niccum, Brittany A; Popodi, Ellen; Townes, Jesse P; Lee, Heewook; MohammedIsmail, Wazim; Tang, Haixu

2018-06-15

Mismatch repair (MMR) is a major contributor to replication fidelity, but its impact varies with sequence context and the nature of the mismatch. Mutation accumulation experiments followed by whole-genome sequencing of MMR-defective E. coli strains yielded ≈30,000 base-pair substitutions, revealing mutational patterns across the entire chromosome. The base-pair substitution spectrum was dominated by A:T > G:C transitions, which occurred predominantly at the center base of 5'N A C3'+5'G T N3' triplets. Surprisingly, growth on minimal medium or at low temperature attenuated these mutations. Mononucleotide runs were also hotspots for base-pair substitutions, and the rate at which these occurred increased with run length. Comparison with ≈2000 base-pair substitutions accumulated in MMR-proficient strains revealed that both kinds of hotspots appeared in the wild-type spectrum and so are likely to be sites of frequent replication errors. In MMR-defective strains transitions were strand biased, occurring twice as often when A and C rather than T and G were on the lagging-strand template. Loss of nucleotide diphosphate kinase increases the cellular concentration of dCTP, which resulted in increased rates of mutations due to misinsertion of C opposite A and T. In an mmr ndk double mutant strain, these mutations were more frequent when the template A and T were on the leading strand, suggesting that lagging-strand synthesis was more error-prone or less well corrected by proofreading than was leading strand synthesis. Copyright © 2018, Genetics.

Choice of mineral fertilizer substitution principle strongly influences LCA environmental benefits of nutrient cycling in the agri-food system.

PubMed

Hanserud, Ola Stedje; Cherubini, Francesco; Øgaard, Anne Falk; Müller, Daniel B; Brattebø, Helge

2018-02-15

Increased nutrient cycling in the agri-food system is a way to achieve a healthier nutrient stewardship and more sustainable food production. In life cycle assessment (LCA) studies, use of recycled fertilizer products is often credited by the substitution method, which subtracts the environmental burdens associated with avoided production of mineral fertilizer from the system under study. The environmental benefits from avoided fertilizer production can make an important contribution to the results, but different calculation principles and often implicit assumptions are used to estimate the amount of avoided mineral fertilizer. This may hinder comparisons between studies. The present study therefore examines how the choice of substitution principles influences LCA results. Three different substitution principles, called one-to-one, maintenance, and adjusted maintenance, are identified, and we test the importance of these in a case study on cattle slurry management. We show that the inventory of avoided mineral fertilizer varies greatly when the different principles are applied, with strong influences on two-thirds of LCA impact categories. With the one-to-one principle, there is a risk of systematically over-estimating the environmental benefits from nutrient cycling. In a sensitivity analysis we show that the difference between the principles is closely related to the application rate and levels of residual nutrients in the soil. We recommend that LCA practitioners first and foremost state and justify the substitution method they use, in order to increase transparency and comparability with other studies. Copyright © 2017 Elsevier B.V. All rights reserved.

The Substitutability of Cigarettes and Food: A Behavioral Economic Comparison in Normal Weight and Overweight or Obese Smokers

PubMed Central

Murphy, Cara M.; Owens, Max M.; Sweet, Lawrence H.; MacKillop, James

2017-01-01

Obesity and cigarette smoking contribute to a multitude of preventable deaths in the US and eating and smoking behavior may influence each other. The field of behavioral economics integrates principles from psychology and economics and permits systematic examination of how commodities interrelate with one another. Using this framework, the current study evaluated the effects of rising food and cigarette prices on consumption to investigate their substitutability and their relationship to BMI and associated variables. Behavioral economics categorizes commodities as substitutable when the consumption of one increases as a function of a price increase in the other. Smokers (N = 86) completed a two-part hypothetical task in which money was allocated to purchase cigarettes and fast food-style reinforcers (e.g., hamburgers, ice cream) at various prices. Results indicated that food and cigarettes were not substitutes for one another (cross-price elasticity coefficients > .20). Food purchases were independent of cigarette price, whereas cigarette purchases decreased as food price rose. Cross-price elasticity coefficients were significantly associated with confidence in one’s ability to control weight without smoking (rs = −.23 and .29), but not BMI (rs = .04 and .04) or post-cessation weight concerns (rs = −.05 and .12). Perceived ability to manage weight without cigarettes may influence who substitutes food for cigarettes when quitting. In addition, given observed decreases in purchases of both commodities as food prices increased, these findings imply that greater taxation of fast food-style reinforcers could potentially reduce consumption of these foods and also cigarettes among smokers. PMID:27736143

The comparison study of bioactivity between composites containing synthetic non-substituted and carbonate-substituted hydroxyapatite.

PubMed

Borkowski, Leszek; Sroka-Bartnicka, Anna; Drączkowski, Piotr; Ptak, Agnieszka; Zięba, Emil; Ślósarczyk, Anna; Ginalska, Grażyna

2016-05-01

Apatite forming ability of hydroxyapatite (HAP) and carbonate hydroxyapatite (CHAP) containing composites was compared. Two composite materials, intended for filling bone defects, were made of polysaccharide polymer and one of two types of hydroxyapatite. The bioactivity of the composites was evaluated in vitro by soaking in a simulated body fluid (SBF), and the formation of the apatite layer was determined by scanning electron microscopy with energy-dispersive spectrometer and Raman spectroscopy. The results showed that both the composites induced the formation of apatite layer on their surface after soaking in SBF. In addition, the sample weight changes and the ion concentration of the SBF were scrutinized. The results showed the weight increase for both materials after SBF treatment, higher weight gain and higher uptake of calcium ions by HAP containing scaffolds. SBF solution analysis indicated loss of calcium and phosphorus ions during experiment. All these results indicate apatite forming ability of both biomaterials and suggest comparable bioactive properties of composite containing pure hydroxyapatite and carbonate-substituted one. Copyright © 2016 Elsevier B.V. All rights reserved.

Inter- and intraspecific mitochondrial DNA variation in North American bears (Ursus)

USGS Publications Warehouse

Cronin, Matthew A.; Amstrup, Steven C.; Garner, Gerald W.; Vyse, Ernest R.

1991-01-01

We assessed mitochondrial DNA variation in North American black bears (Ursus americanus), brown bears (Ursus arctos), and polar bears (Ursus maritimus). Divergent mitochondrial DNA haplotypes (0.05 base substitutions per nucleotide) were identified in populations of black bears from Montana and Oregon. In contrast, very similar haplotypes occur in black bears across North America. This discordance of haplotype phylogeny and geographic distribution indicates that there has been maintenance of polymorphism and considerable gene flow throughout the history of the species. Intraspecific mitochondrial DNA sequence divergence in brown bears and polar bears is lower than in black bears. The two morphological forms of U. arctos, grizzly and coastal brown bears, are not in distinct mtDNA lineages. Interspecific comparisons indicate that brown bears and polar bears share similar mitochondrial DNA (0.023 base substitutions per nucleotide) which is quite divergent (0.078 base substitutions per nucleotide) from that of black bears. High mitochondrial DNA divergence within black bears and paraphyletic relationships of brown and polar bear mitochondrial DNA indicate that intraspecific variation across species' ranges should be considered in phylogenetic analyses of mitochondrial DNA.

Is nevtral NEUTRAL? Visual similarity effects in the early phases of written-word recognition.

PubMed

Marcet, Ana; Perea, Manuel

2017-08-01

For simplicity, contemporary models of written-word recognition and reading have unspecified feature/letter levels-they predict that the visually similar substituted-letter nonword PEQPLE is as effective at activating the word PEOPLE as the visually dissimilar substituted-letter nonword PEYPLE. Previous empirical evidence on the effects of visual similarly across letters during written-word recognition is scarce and nonconclusive. To examine whether visual similarity across letters plays a role early in word processing, we conducted two masked priming lexical decision experiments (stimulus-onset asynchrony = 50 ms). The substituted-letter primes were visually very similar to the target letters (u/v in Experiment 1 and i/j in Experiment 2; e.g., nevtral-NEUTRAL). For comparison purposes, we included an identity prime condition (neutral-NEUTRAL) and a dissimilar-letter prime condition (neztral-NEUTRAL). Results showed that the similar-letter prime condition produced faster word identification times than the dissimilar-letter prime condition. We discuss how models of written-word recognition should be amended to capture visual similarity effects across letters.

Complete chloroplast genome of Tetragonia tetragonioides: Molecular phylogenetic relationships and evolution in Caryophyllales.

PubMed

Choi, Kyoung Su; Kwak, Myounghai; Lee, Byoungyoon; Park, SeonJoo

2018-01-01

The chloroplast genome of Tetragonia tetragonioides (Aizoaceae; Caryophyllales) was sequenced to provide information for studies on phylogeny and evolution within Caryophyllales. The chloroplast genome of Tetragonia tetragonioides is 149,506 bp in length and includes a pair of inverted repeats (IRs) of 24,769 bp that separate a large single copy (LSC) region of 82,780 bp and a small single copy (SSC) region of 17,188 bp. Comparative analysis of the chloroplast genome showed that Caryphyllales species have lost many genes. In particular, the rpl2 intron and infA gene were not found in T. tetragonioides, and core Caryophyllales lack the rpl2 intron. Phylogenetic analyses were conducted using 55 genes in 16 complete chloroplast genomes. Caryophyllales was found to divide into two clades; core Caryophyllales and noncore Caryophyllales. The genus Tetragonia is closely related to Mesembryanthemum. Comparisons of the synonymous (Ks), nonsynonymous (Ka), and Ka/Ks substitution rates revealed that nonsynonymous substitution rates were lower than synonymous substitution rates and that Ka/Ks rates were less than 1. The findings of the present study suggest that most genes are a purified selection.

A new β chain hemoglobin variant with increased oxygen affinity: Hb Santa Giusta Sardegna [β93(F9)Cys→Trp; HBB c.282T>G].

PubMed

Fais, Antonella; Sollaino, Maria Carla; Barella, Susanna; Perseu, Lucia; Era, Benedetta; Corda, Marcella

2012-01-01

During a screening program for the identification of β-thalassemia (β-thal) carriers in Sardinia, Italy, we identified two subjects with increased hemoglobin (Hb) levels and an abnormal Hb variant. The same variant was detected in a family member. DNA sequencing revealed a TGT > TGG mutation at codon 93 of the β-globin gene. Structural analysis demonstrated that the cystine residue at position 93 of the β chain was substituted by tryptophan. Since this amino acid substitution had not yet been reported, we designated this variant Hb Santa Giusta Sardegna for the place of birth of the subjects. This amino acid substitution occurs at the tyrosine pocket of the β chain as well as at the α1β2/α2β1 contact of the quaternary structure of the molecule. The presence of this Hb in the hemolysate causes an increased oxygen affinity, a slightly reduced Bohr effect and a reduced heme-heme interaction (n(50), Hill's constant) in comparison with those of Hb A.

Salt microspheres and potassium chloride usage for sodium reduction: Case study with sushi.

PubMed

Đorđević, Đani; Buchtová, Hana; Macharáčková, Blanka

2018-01-01

The aim of the study was to estimate possibilities of salt substitutes usage in the preparation of two sushi types (nigiri and maki) prepared with different seafood (salmon: Salmo salar, tuna: Thunnus albacares, and shrimp: Pleoticus muelleri). Potassium chloride (Mary samples), Soda-Lo (hollowed microsphere of regular salt crystals), and regular salt (sodium chloride) were used in the experiment. Sushi samples (n = 1960) were evaluated by 40 trained panelists who noticed that maki shrimp samples prepared with Mary salt had higher bitterness (21.48 ± 28.01) in comparison with 2% sodium chloride (7.91 ± 8.80). The saltiness was lower in nigiri tuna prepared with Mary (49.59 ± 17.47) than 2% sodium chloride (61.11 ± 15.75). The study clearly showed the possibility of lowering sodium content in sushi meal with the usage of salt substitutes, with emphasis that Soda-Lo should be considered as a better option due to the retention of sensory properties in sushi samples prepared with this salt substitute.

Nonneutral mitochondrial DNA variation in humans and chimpanzees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nachman, M.W.; Aquadro, C.F.; Brown, W.M.

1996-03-01

We sequenced the NADH dehydrogenase subunit 3 (ND3) gene from a sample of 61 humans, five common chimpanzees, and one gorilla to test whether patterns of mitochondrial DNA (mtDNA) variation are consistent with a neutral model of molecular evolution. Within humans and within chimpanzees, the ratio of replacement to silent nucleotide substitutions was higher than observed in comparisons between species, contrary to neutral expectations. To test the generality of this result, we reanalyzed published human RFLP data from the entire mitochondrial genome. Gains of restriction sites relative to a known human mtDNA sequence were used to infer unambiguous nucleotide substitutions.more » We also compared the complete mtDNA sequences of three humans. Both the RFLP data and the sequence data reveal a higher ratio of replacement to silent nucleotide substitutions within humans than is seen between species. This pattern is observed at most or all human mitochondrial genes and is inconsistent with a strictly neutral model. These data suggest that many mitochondrial protein polymorphisms are slightly deleterious, consistent with studies of human mitochondrial diseases. 59 refs., 2 figs., 8 tabs.« less

Fluoride-containing podophyllum derivatives exhibit antitumor activities through enhancing mitochondrial apoptosis pathway by increasing the expression of caspase-9 in HeLa cells

PubMed Central

Zhao, Wei; Yang, Yong; Zhang, Ya-Xuan; Zhou, Chen; Li, Hong-Mei; Tang, Ya-Ling; Liang, Xin-Hua; Chen, Tao; Tang, Ya-Jie

2015-01-01

This work aims to provide sampling of halogen-containing aniline podophyllum derivatives and their mode of action with an in-depth comparison among fluorine, chloride and bromide for clarifying the important role and impact of fluorine substitution on enhancing antitumor activity, with an emphasis on the development of drug rational design for antitumor drug. The tumor cytotoxicity of fluoride-containing aniline podophyllum derivatives were in general improved by 10–100 times than those of the chloride and bromide-containing aniline podophyllum derivatives since fluoride could not only strongly solvated in protic solvents but also forms tight ion pairs in most aprotic solvents. When compared with chloride and bromide, the higher electronegativity fluoride substituted derivatives significantly enhanced mitochondrial apoptosis pathway by remarkably increasing the expression of caspase-9 in HeLa cells. The current findings would stimulate an enormous amount of research directed toward exploiting novel leading compounds based on podophyllum derivatives, especially for the fluoride-substituted structures with promising antitumor activity. PMID:26608216

Purification and characterization of galanin and scyliorhinin I from the hybrid sturgeon, Scaphirhynchus platorynchus x Scaphirhynchus albus (Acipenseriformes).

PubMed

Wang, Y; Barton, B A; Thim, L; Nielsen, P F; Conlon, J M

1999-01-01

The sturgeons (order Acipenseriformes) are extant representatives of a group of ancient Actinopterygian (ray-finned) fish. Galanin and scyliorhinin I (a tachykinin with limited structural similarity to mammalian substance P) have been isolated from an extract of the gastrointestinal tract of a sturgeon (an F1 hybrid between the shovelnose sturgeon, Scaphirhynchus platorynchus, and the pallid sturgeon, Scaphirhynchus albus). The primary structure of sturgeon galanin (Gly-Trp-Thr-Leu-Asn-Ser-Ala-Gly-Tyr-Leu10-Leu-Gly-Pro-His-Ala-Val -As p-Gly-His-Arg20-Ser-Leu-Ser-Asp-Lys-His-Gly-Leu-Pro.NH2) contains only two amino acid substitutions (Ser23 --> Asn and Pro29 --> Ala) compared with galanin from the bowfin, Amia calva (Amiiformes), but five amino acid substitutions compared with galanin from the trout (Teleostei). Similarly, the sturgeon tachykinin (Ser-Lys-Tyr-His-Gln-Phe-Tyr-Gly-Leu-Met.NH2) contains only one amino acid substitution (Tyr3 --> Ser) compared with scyliorhinin I previously isolated from bowfin stomach but five amino acid substitutions compared with trout substance P. The data support the hypothesis that the Acipenseriformes and the basal Neopterygians (gars and bowfin) share a close phylogenetic relationship. Copyright 1999 Academic Press.

The impact of generic substitution on the turnover and gross margin of pharmaceutical companies a survey 1 year and 5 years after the introduction of generic substitution in Finland.

PubMed

Timonen, Johanna; Karttunen, Pekka; Bengtström, Marina; Ahonen, Riitta

2009-10-01

To explore and compare the impact of generic substitution (GS) on the turnover and gross margin per cent of pharmaceutical companies representing mainly original or generic products in Finland. A mail survey to pharmaceutical companies with an office in Finland and substitutable medicines in the Finnish pharmaceutical market 1 year (2004) and nearly 5 years (2008) after GS. The questionnaire were answered by 16 original and 7 generic product companies in 2004 (response rate 56%, n=41) and by 16 original and 6 generic product companies in 2008 (response rate 56%, n=39). Turnover had decreased in the original product companies and increased in the generic product companies. The gross margin per cent had decreased in the original and generic product companies, and the companies had also compensated for it in many ways. The study suggests that GS has promoted the sales of generic product companies in Finland. However, price competition caused by GS has generally decreased the proportion of profit from turnover in the original and generic product companies. The companies have also compensated for their decreased gross margin, which suggests that the profit in euros has not been sufficient to cover fixed costs in the companies.

Beta-methyl substitution of cyclohexylalanine in Dmt-Tic-Cha-Phe peptides results in highly potent delta opioid antagonists.

PubMed

Tóth, Géza; Ioja, Eniko; Tömböly, Csaba; Ballet, Steven; Tourwé, Dirk; Péter, Antal; Martinek, Tamás; Chung, Nga N; Schiller, Peter W; Benyhe, Sándor; Borsodi, Anna

2007-01-25

The opioid peptide TIPP (H-Tyr-Tic-Phe-Phe-OH, Tic:1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) was substituted with Dmt (2',6'-dimethyltyrosine) and a new unnatural amino acid, beta-MeCha (beta-methyl-cyclohexylalanine). This double substitution led to a new series of opioid peptides displaying subnanomolar delta antagonist activity and mu agonist or antagonist properties depending on the configuration of the beta-MeCha residue. The most promising analog, H-Dmt-Tic-(2S,3S)-beta-MeCha-Phe-OH was a very selective delta antagonist both in the mouse vas deferens (MVD) assay (Ke = 0.241 +/- 0.05 nM) and in radioligand binding assay (K i delta = 0.48 +/- 0.05 nM, K i mu/K i delta = 2800). The epimeric peptide H-Dmt-Tic-(2S,3R)-beta-MeCha-Phe-OH and the corresponding peptide amide turned out to be mixed partial mu agonist/delta antagonists in the guinea pig ileum and MVD assays. Our results constitute further examples of the influence of Dmt and beta-methyl substitution as well as C-terminal amidation on the potency, selectivity, and signal transduction properties of TIPP related peptides. Some of these compounds represent valuable pharmacological tools for opioid research.

Peanut cake as a substitute for soybean meal in the diet of goats.

PubMed

Silva, T Mariniello; de Medeiros, A Nunes; Oliveira, R Lopes; Gonzaga Neto, S; Ribeiro, M Divino; Bagaldo, A Regina; Ribeiro, O Lolato

2015-06-01

This study aimed to test the hypothesis that peanut cake can substitute for soybean meal in the feed of ruminants on the basis of the intake, performance, digestion, and serum urea and glucose concentration in crossbred Boer × indigenous goat kids. Forty intact vaccinated and dewormed crossbred Boer × indigenous goat kids (average age = 5 mo, average BW = 15.6 ± 2.7 kg) were used. The goats were fed Tifton-85 (Cynodon dactylon) hay and concentrate mixes of corn bran, soybean meal, premix mineral, and peanut cake substituted for soybean meal at rates of 0.0%, 33.33%, 66.67%, and 100%. The animals were confined for 62 d, and the digestibility trial was performed from d 27 to 31 of confinement. Samples of orts and feces were quantified and collected from each animal during this period. On the d 32 of confinement, a blood sample was taken from animals to measure urea N and glucose. Data were analyzed with a regression model. Substitution of soybean meal with peanut cake in the diet of the animals resulted in a reduction in intake of DM (P = 0.02), CP (P = 0.03), NDF (P = 0.03), nonfiber carbohydrate (NFC; P = 0.01), and TDN (P = 0.02) and an increase in intake of ether extract (P < 0.001). The total and daily average weight gains decreased (P = 0.02) with substitution, whereas G:F was not influenced (P = 0.11). With the exception of ether extract digestibility, which increased (P < 0.001) with substitution, digestibility of DM (P = 0.13), OM (P = 0.18), CP (P = 0.54), NDF (P = 0.20), and NFC (P = 0.73) was not influenced by diets. The concentration of serum urea N was influenced quadratically by the postprandial time for treatments with 33.33%, 66.67%, and 100.00% substitution. Peanut cake is not a complete, equal substitute for soybean meal in goat feed. However, peanut cake may represent an eventual replacer able to reduce goat producers’ dependence on traditional ingredients in the feed of growing goat kids.

Reproducible Crystallite Size of Mono-Dispersed and Scalable Biologically Produced Metal-Substituted Nanometer-Sized Magnetites

NASA Astrophysics Data System (ADS)

Moon, J.; Rawn, C.; Rondinone, A.; Love, L.; Roh, Y.; Lauf, R.; Phelps, T.

2008-12-01

Our previous research demonstrated that biosynthesized magnetite (biomagnetite) exhibited similar properties as chemically synthesized magnetite. To complement uses of the traditional chemically synthesized magnetite (chem-magnetite) biomagnetite must be exhibit highly reproducible sizes and be available in scalable qualities. Here we emphasize potentially advantageous properties of biomagnetite regarding size, reproducibility and scaling availability. Average crystallite size (ACS) of biomagnetites ranging from 10-100 nm was determined after varied 1) incubation times, 2) substitution of metal and lanthanide species, 3) degrees of congruent incorporation or retardation of substitution elements, 4) bacterial species with their varied ability to substitute elemental species, and 6) incubation temperature that can influence coalescence. The microbial production of biomagnetite has demonstrated capacity to make highly crystalline nanoscale particles of metal-substituted ferrites including compounds of Co, Ni, Cr, Mn, Zn and the rare earths in large quantity. Selected Zn-substituted magnetite (nominal composition of Zn0.6Fe2.4O4) has been recovered at over 1 kg (wet weight) in batches from 30 L fermentations. The massively produced extracellular magnetites were confirmed to exhibit good mono- dispersity via transmission electron microscopy (TEM). TEM also validated highly reproducible ACS of 13.1±0.8 nm size as determined through X-ray diffraction (N=7) at a 99 % confidence level. Based on the scale-up experiments performed using the 35 L reactor, the reduction in ACS variability and shorted incubation times of several days may be attributed to increases of electron donor input, and availability of divalent ions of the substitution metal with less ferrous ions in the case of doped magnetite, or a combination of the above. While costs of commercial nanometer sized magnetite (25-50 nm) may vary from 500/kg to > 1,000/kg, microbial mass production is likely capable of producing 13-90 nm magnetite or doped magnetites at a fraction of the cost of traditional chemical synthesis. While there are numerous approaches for the synthesis of nanoparticles, bacterial fermentation of magnetite or metal-substituted magnetite may represent a disruptive manufacturing technology with respect to yield, reproducibility and scalability.

Inhibition Of Molecular And Biological Processes Using Modified Oligonucleotides

DOEpatents

Kozyavkin, Sergei A.; Malykh, Andrei G.; Polouchine, Nikolai N.; Slesarev, Alexei I.

2003-04-15

A method of inhibiting at least one molecular process in a sample, comprising administering to the sample an oligonucleotide or polynucleotide containing at least one monomeric unit having formula (I): wherein A is an organic moiety, n is at least 1, and each X is independently selected from the group consisting of --NRCOCONu, --NHCOCR.sub.2 CR.sub.2 CONu, --NHCOCR.dbd.CRCONu, and --NHCOSSCONu, wherein each R independently represents H or a substituted or unsubstituted alkyl group, and Nu represents a nucleophile, or a salt of the compound.

Comparison of the Performance of College Students Classified as ADHD, LD, and LD/ADHD in Foreign Language Courses

ERIC Educational Resources Information Center

Sparks, Richard L.; Javorsky, James; Philips, Lois

2005-01-01

In this study, college students classified as having attention deficit hyperactivity disorder (ADHD) who had fulfilled the foreign language (FL) requirement were compared with students classified as learning disabled (LD) or both LD and ADHD who had either substituted courses for the college FL requirement petition or had passed FL courses…

[Analysis of regions determining resistence to fluoroquinolones in genes gyrA and parC in clinical isolates of Mycoplasma hominis].

PubMed

Gushchin, A E; Ladygina, V G; Govorun, V M; Taraskina, A M; Savicheva, A M

2000-01-01

Fifteen strains of M. hominis isolated from patients with urogenital inflammations were analyzed. Variations in the quinolone resistance-determining regions (QRDR) have been found in fluoroquinolone-resistant M. hominis clinical isolates in comparison with the reference PG21 strain. In one isolate, parC had Asn substitute at position 91.

Reading, Comprehension, and Memory Processes: Abstracts of Doctoral Dissertations Published in "Dissertation Abstracts International," July through September 1978 (Vol. 39 Nos. 1 through 3).

ERIC Educational Resources Information Center

ERIC Clearinghouse on Reading and Communication Skills, Urbana, IL.

This collection of abstracts is part of a continuing series providing information on recent doctoral dissertations. The 12 titles deal with the following topics: advance organizers; a comparison of the effectiveness and efficiency of behavioral objectives and sample tests; anaphoric nominal substitution and its relationship to reading…

Induction of lycopene and lycopene precursors in germinating cottonseedwith the substituted triethylamine compound MPTA

USDA-ARS?s Scientific Manuscript database

Treatment of dark germinating cottonseed (Gossypium hirsutum Acala cultivar) with 0.72 mM 2(4-methylphenoxy) triethylamine (MPTA) resulted in a 18-fold increase in carotenoid biosynthesis. In comparison to H2O treated control seed germinating in the dark that formed 8.4 ug/g fr wt of lutein and 1.6 ...

Suitability of unmalted quinoa for beer production.

PubMed

Kordialik-Bogacka, Edyta; Bogdan, Paulina; Pielech-Przybylska, Katarzyna; Michałowska, Dorota

2018-03-30

This study provides the first detailed investigation into the effect of partially substituting barley malt with quinoa (Chenopodium quinoa Willd.) on the characteristics of wort and beer. Quinoa seeds and flakes were compared in terms of their suitability for brewing. The benefits of applying a commercial enzyme mixture during beer production with quinoa were also investigated. These findings show that quinoa is a good starchy raw material for brewing. Even without exogenous enzymes, it is possible to substitute barley malt with up to 30% quinoa. The form in which quinoa is used has a negligible influence on the quality of the wort and beer. The foam stability of beer made with quinoa was better than that of all-malt beer, despite there being a lower level of soluble nitrogen in quinoa beer in comparison with all-malt beer and more than twice the amount of fat in quinoa in comparison to barley malt. The addition of unmalted quinoa does not give unpleasant characteristics to the beer and was even found to have a positive effect on its overall sensory quality. This offers brewers an opportunity to develop good beers with new sensory characteristics. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Anti-progestins suppress the growth of established tumors induced by 7,12-dimethylbenz(a)anthracene: comparison between RU486 and a new 21-substituted-19-nor-progestin.

PubMed

Wiehle, Ronald D; Christov, Konstantin; Mehta, Rajendra

2007-07-01

In this report, we evaluate the effects of a 21-substituted-19-nor-progestin, CDB-4124, on 7,12,-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis in rats in comparison with RU486. Sprague-Dawley female rats were treated with DMBA at 50 days of age in order to induce mammary tumors. When the tumors reached the size of 10-12 mm, the animals were treated for 28 days with the vehicle, RU486, progesterone, CDB-4124 at various doses, or CDB-4124 plus progesterone. Anti-progestins resulted in the regression in the size of the existing tumors, and in the suppressed development of new tumors and tumor multiplicity. Progesterone treatment, however, increased the size and multiplicity. Progesterone rendered an increased number of growing tumors as compared to the regression in the anti-progesterone treatment groups. The combination of CDB-4124 and high doses of progesterone opposed the efficacy of CDB-4124. The growth inhibitory effects of the anti-progestins were correlated with increased apoptosis and reduced cell proliferation. These results indicate that anti-progestins should be developed for the chemoprevention and treatment of hormone-responsive breast cancer.

Steam Reforming of CH4 Using Ni- Substituted Pyrochlore Catalysts

NASA Astrophysics Data System (ADS)

Haynes, Daniel J.

The steam reforming of methane (SMR) continues to remain an important industrial reaction for large-scale production of H2 as well as synthesis gas mixtures which can be used for the production of useful chemicals (e.g. methanol). Although SMR is a rather mature technology, traditional nickel based catalysts used industrially are subjected to severe temperatures and reaction conditions, which lead to irreversible activity loss through sintering, support collapse, and carbon formation. Pyrochlore-based mixed oxide have been identified as refractory materials that can be modified through the substitution of catalytic metals and other promoting species into the structure to mitigate these issues causing deactivation. For this study, a lanthanum zirconate pyrochlore catalyst was substituted with Ni to determine whether the oxide structure could effectively stabilize the activity of the catalytic metal during the SMR. The effect of different variables including calcination temperature, a comparison of a substituted versus supported Ni pyrochlore catalyst, Ni weight loading, and Sr promotion have been evaluated to determine the location of the Ni in the structure, and their effect on catalytic behavior. It was revealed that the effect of calcination temperature on a 6wt% Ni substituted pyrochlore produced by the Pechini method demonstrated very little Ni was soluble in the pyrochlore lattice. It was further revealed that by XRD, TEM, and atom probe tomography that, despite the metal loading, Ni exsolves from the structure upon crystallization of the pyrochlore at 700°C, and forms NiO at the surface and grain boundaries. An additional separate La2ZrNiO6 perovskite phase also began to form at higher temperatures (>800°C). Increasing calcination temperature was found to lead to slight sintering of the NiO at the surface, which made the NiO more reducible. Meanwhile decreasing the Ni weight loading was found to produce a lower reduction temperature due to the presence of less lanthanum at the surface. Comparing the XANES and EXAFS profiles for the supported and substituted Ni catalysts showed no detectable difference between the spectra, further confirming the Ni to be present as NiO after substitution. Activity testing found the NiO on the surface to be the active catalytic form. However, the Ni proved to be highly sensitive to sintering and oxidation by steam, especially under high pressures (1.8 MPa), which caused all catalysts to suffer irreversible activity loss. Low reaction pressures (0.23 MPa) elicited an activation effect in which the Ni initially lost activity, but then recovered to near equilibrium yields after nearly 10 hours time on stream. The activation was correlated with an increase in Ni particle size, as observed by XRD. It is speculated from similar behavior reported in the literature that ability to recovery activity was linked to a redox cycling of the Ni particles under reaction conditions, in which a small amount of the Ni was redistributed over the surface through the volatilization with steam, as well as the exsolution of the Sr from the structure which helped stabilize the Ni. A comparison of the supported and substituted forms of Ni showed the substituted form to have a weaker interaction with the pyrochlore surface, which is the likely cause for the rapid sintering and deactivation by steam. It was also found that the substitution of more Sr into the structure produced only strong basic sites, which resulted in a lower degree of activity loss and more stable activity under high pressure conditions (1.8 MPa) compared to the catalyst with less Sr. Carbon formation was not an issue for these materials, due to the rapid sintering and oxidation of the metal in-situ. Fitting the Ni particle size growth with time showed a parabolic relationship with growth proportional to time by the power 0.28. This value is close to results observed in the literature which indicates the Ni agglomerates via atomic migration.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Occena, J.; Jen, T.; Rizzi, E. E.

We have examined the influence of bismuth (Bi) and nitrogen (N) fluxes on N and Bi incorporation during molecular-beam epitaxy of GaAs 1-x-yN xBi y alloys. The incorporation of Bi is found to be independent of N flux, while the total N incorporation and the fraction of N atoms occupying non-substitutional lattice sites increase with increasing Bi flux. A comparison of channeling nuclear reaction analysis along the [100], [110], and [111] directions with Monte Carlo-Molecular Dynamics simulations indicates that the non-substitutional N primarily incorporate as (N-As) As interstitial complexes. We discuss the influence of Bi adatoms on the formation ofmore » arsenic-terminated [110]-oriented step-edges and the resulting enhancement in total N incorporation via the formation of additional (N-As) As.« less

Comparative investigation of diagnosis media for induction machine mechanical unbalance fault.

PubMed

Salah, Mohamed; Bacha, Khmais; Chaari, Abdelkader

2013-11-01

For an induction machine, we suggest a theoretical development of the mechanical unbalance effect on the analytical expressions of radial vibration and stator current. Related spectra are described and characteristic defect frequencies are determined. Moreover, the stray flux expressions are developed for both axial and radial sensor coil positions and a substitute diagnosis technique is proposed. In addition, the load torque effect on the detection efficiency of these diagnosis media is discussed and a comparative investigation is performed. The decisive factor of comparison is the fault sensitivity. Experimental results show that spectral analysis of the axial stray flux can be an alternative solution to cover effectiveness limitation of the traditional stator current technique and to substitute the classical vibration practice. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Bi-enhanced N incorporation in GaAsNBi alloys

NASA Astrophysics Data System (ADS)

Occena, J.; Jen, T.; Rizzi, E. E.; Johnson, T. M.; Horwath, J.; Wang, Y. Q.; Goldman, R. S.

2017-06-01

We have examined the influence of bismuth (Bi) and nitrogen (N) fluxes on N and Bi incorporation during molecular-beam epitaxy of GaAs1-x-yNxBiy alloys. The incorporation of Bi is found to be independent of N flux, while the total N incorporation and the fraction of N atoms occupying non-substitutional lattice sites increase with increasing Bi flux. A comparison of channeling nuclear reaction analysis along the [100], [110], and [111] directions with Monte Carlo-Molecular Dynamics simulations indicates that the non-substitutional N primarily incorporate as (N-As)As interstitial complexes. We discuss the influence of Bi adatoms on the formation of arsenic-terminated [110]-oriented step-edges and the resulting enhancement in total N incorporation via the formation of additional (N-As)As.

Novel platelet substitutes: disk-shaped biodegradable nanosheets and their enhanced effects on platelet aggregation.

PubMed

Okamura, Yosuke; Fukui, Yoshihito; Kabata, Koki; Suzuki, Hidenori; Handa, Makoto; Ikeda, Yasuo; Takeoka, Shinji

2009-10-21

We have studied biocompatible spherical carriers carrying a dodecapeptide, HHLGGAKQAGDV (H12), on their surface as platelet substitutes. This peptide is a fibrinogen γ-chain carboxy-terminal sequence (γ400-411) and specifically recognizes the active form of glycoprotein IIb/IIIa on activated platelets. Our purpose is to assess the possibility of making a novel platelet substitute consisting of disk-shaped nanosheets having a large contact area for the targeting site, rather than conventional small contact area spherical carriers. The H12 peptide was conjugated to the surface of the free-standing nanosheets made of biodegradable poly(d,l-lactide-co-glycolide) (PLGA). These H12-PLGA nanosheets were fabricated onto 3 μm disk-shaped patterned hydrophobic octadecyl regions on a SiO(2) substrate. By way of comparison, spherical H12-PLGA microparticles with the same surface area and conjugation number of H12 were also prepared. The resulting H12-PLGA nanosheets specifically interacted with the activated platelets adhered on the collagen surface at twice the rate of the H12-PLGA microparticles under flow conditions, and showed platelet thrombus formation in a two-dimensional spreading manner. Thus, H12-PLGA nanosheets might be a suitable candidate novel platelet alternative substitute for infused human platelet concentrates for the treatment of bleeding in patients with severe thrombocytopenia.

DNA-fiber EPR investigation of the influence of amino-terminal residue stereochemistry on the DNA binding orientation of Cu(II)•Gly-Gly-His-derived metallopeptides

PubMed Central

Hamada, Hirokazu; Abe, Yuko; Nagane, Ryoichi; Fang, Ya-Yin; Lewis, Mark A.; Long, Eric C.; Chikira, Makoto

2007-01-01

DNA fiber EPR was used to investigate the DNA binding stabilities and orientations of Cu(II)•Gly-Gly-His-derived metallopeptides containing d- vs. l-amino acid substitutions in the first peptide position. This examination included studies of Cu(II)•d-Arg-Gly-His and Cu(II)•d-Lys-Gly-His for comparison to metallopeptides containing l-Arg/Lys substitutions, and also the diastereoisomeric pairs Cu(II)•d/l-Pro-Gly-His and Cu(II)•d/l-Pro-Lys-His. Results indicated that l-Arg/Lys to d-Arg/Lys substitutions considerably randomized the orientation of the metallopeptides on DNA whereas the replacement of l-Pro by d-Pro in Cu(II)•l-Pro-Gly-His caused a decrease in randomness. The difference in the extent of randomness of d- vs. l-Pro-Gly-His complexes was diminished through the substitution of Gly for Lys in the middle peptide position, supporting the notion that the ε-amino group of Lys triggered further randomization, likely through hydrogen bonding or electrostatic interactions that disrupt binding of the metallopeptide equatorial plane and the DNA. The relationship between the stereochemistry of amino acid residues and the binding and reaction of M(II)•Xaa-Xaa’-His metallopeptides with DNA are also discussed. PMID:17706784

Coevolution between Nuclear-Encoded DNA Replication, Recombination, and Repair Genes and Plastid Genome Complexity

PubMed Central

Zhang, Jin; Ruhlman, Tracey A.; Sabir, Jamal S. M.; Blazier, John Chris; Weng, Mao-Lun; Park, Seongjun; Jansen, Robert K.

2016-01-01

Disruption of DNA replication, recombination, and repair (DNA-RRR) systems has been hypothesized to cause highly elevated nucleotide substitution rates and genome rearrangements in the plastids of angiosperms, but this theory remains untested. To investigate nuclear–plastid genome (plastome) coevolution in Geraniaceae, four different measures of plastome complexity (rearrangements, repeats, nucleotide insertions/deletions, and substitution rates) were evaluated along with substitution rates of 12 nuclear-encoded, plastid-targeted DNA-RRR genes from 27 Geraniales species. Significant correlations were detected for nonsynonymous (dN) but not synonymous (dS) substitution rates for three DNA-RRR genes (uvrB/C, why1, and gyrA) supporting a role for these genes in accelerated plastid genome evolution in Geraniaceae. Furthermore, correlation between dN of uvrB/C and plastome complexity suggests the presence of nucleotide excision repair system in plastids. Significant correlations were also detected between plastome complexity and 13 of the 90 nuclear-encoded organelle-targeted genes investigated. Comparisons revealed significant acceleration of dN in plastid-targeted genes of Geraniales relative to Brassicales suggesting this correlation may be an artifact of elevated rates in this gene set in Geraniaceae. Correlation between dN of plastid-targeted DNA-RRR genes and plastome complexity supports the hypothesis that the aberrant patterns in angiosperm plastome evolution could be caused by dysfunction in DNA-RRR systems. PMID:26893456

Asymmetric allylation of α-ketoester-derived N-benzoylhydrazones promoted by chiral sulfoxides/N-oxides Lewis bases: highly enantioselective synthesis of quaternary α-substituted α-allyl-α-amino acids.

PubMed

Reyes-Rangel, Gloria; Bandala, Yamir; García-Flores, Fred; Juaristi, Eusebio

2013-09-01

Chiral sulfoxides/N-oxides (R)-1 and (R,R)-2 are effective chiral promoters in the enantioselective allylation of α-keto ester N-benzoylhydrazone derivatives 3a-g to generate the corresponding N-benzoylhydrazine derivatives 4a-g, with enantiomeric excesses as high as 98%. Representative hydrazine derivatives 4a-b were subsequently treated with SmI2, and the resulting amino esters 5a-b with LiOH to obtain quaternary α-substituted α-allyl α-amino acids 6a-b, whose absolute configuration was assigned as (S), with fundament on chemical correlation and electronic circular dichroism (ECD) data. © 2013 Wiley Periodicals, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schafer, Marion; Bobev, Svilen

This paper presents results from our exploratory work in the systems K-Cd-Ge, Rb-Cd-Ge, and Cs-Cd-Ge, which yielded the novel type-I clathrates with refined compositions K 8Cd 3.77(7)Ge 42.23, Rb 8Cd 3.65(7)Ge 42.35, and Cs 7.80(1)Cd 3.65(6)Ge 42.35. The three compounds represent rare examples of clathrates of germanium with the alkali metals, where a d 10 element substitutes a group 14 element. The three structures, established by single-crystal X-ray diffraction, indicate that the framework-building Ge atoms are randomly substituted by Cd atoms on only one of the three possible crystallographic sites. Furthermore, this and several other details of the crystal chemistrymore » are elaborated.« less

Asymmetric Radical Cyclopropanation of Alkenes with In Situ-Generated Donor-Substituted Diazo Reagents via Co(II)-Based Metalloradical Catalysis.

PubMed

Wang, Yong; Wen, Xin; Cui, Xin; Wojtas, Lukasz; Zhang, X Peter

2017-01-25

Donor-substituted diazo reagents, generated in situ from sulfonyl hydrazones in the presence of base, can serve as suitable radical precursors for Co(II)-based metalloradical catalysis (MRC). The cobalt(II) complex of D 2 -symmetric chiral porphyrin [Co(3,5-Di t Bu-Xu(2'-Naph)Phyrin)] is an efficient metalloradical catalyst that is capable of activating different N-arylsulfonyl hydrazones for asymmetric radical cyclopropanation of a broad range of alkenes, affording the corresponding cyclopropanes in high yields with effective control of both diastereo- and enantioselectivity. This Co(II)-based metalloradical system represents the first catalytic protocol that can effectively utilize donor-type diazo reagents for asymmetric olefin cyclopropanation.

Genome-scale reconstruction of the sigma factor network in Escherichia coli: topology and functional states

PubMed Central

2014-01-01

Background At the beginning of the transcription process, the RNA polymerase (RNAP) core enzyme requires a σ-factor to recognize the genomic location at which the process initiates. Although the crucial role of σ-factors has long been appreciated and characterized for many individual promoters, we do not yet have a genome-scale assessment of their function. Results Using multiple genome-scale measurements, we elucidated the network of σ-factor and promoter interactions in Escherichia coli. The reconstructed network includes 4,724 σ-factor-specific promoters corresponding to transcription units (TUs), representing an increase of more than 300% over what has been previously reported. The reconstructed network was used to investigate competition between alternative σ-factors (the σ70 and σ38 regulons), confirming the competition model of σ substitution and negative regulation by alternative σ-factors. Comparison with σ-factor binding in Klebsiella pneumoniae showed that transcriptional regulation of conserved genes in closely related species is unexpectedly divergent. Conclusions The reconstructed network reveals the regulatory complexity of the promoter architecture in prokaryotic genomes, and opens a path to the direct determination of the systems biology of their transcriptional regulatory networks. PMID:24461193

Total cross sections for positron scattering from benzene, cyclohexane, and aniline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zecca, Antonio; Moser, Norberto; Perazzolli, Chiara

2007-08-15

We use a linear transmission technique to measure total cross sections for positron scattering from benzene, cyclohexane, and aniline. In the case of cyclohexane, the energy range of the present study is 0.1-20 eV, while for benzene and aniline it is 0.2-20 eV. With respect to benzene and cyclohexane, comparison is made to the only other existing results we know of [Makochekanwa and co-workers, Phys. Rev. A 68, 032707 (2003); 72, 042705 (2005)]. Agreement with those data is only marginal, being particularly poor at the overlap lower energies. Unlike Kimura et al. [J. Phys. B 37, 1461 (2004)], we findmore » the low-energy dependence of the positron-benzene total cross sections to be qualitatively similar to those found in the electron channel [Gulley et al., J. Phys. B 31, 2735 (1998)]. We believe that the present positron-aniline total cross sections represent the first time such data have been measured. These cross sections are almost identical to those we found for benzene, suggesting that substitution of hydrogen by the amine group on the aromatic ring is largely irrelevant to the scattering process in the energy regimes considered.« less

40 CFR 419.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

...), the Regional Administrator may substitute TOC as a parameter in lieu of COD Effluent limitations for TOC shall be based on effluent data from the plant correlating TOC to BOD5. If in the judgment of the Regional Administrator, adequate correlation data are not available, the effluent limitations for TOC shall...

New small-molecule inhibitor class targeting human immunodeficiency virus type 1 virion maturation.

PubMed

Blair, Wade S; Cao, Joan; Fok-Seang, Juin; Griffin, Paul; Isaacson, Jason; Jackson, R Lynn; Murray, Edward; Patick, Amy K; Peng, Qinghai; Perros, Manos; Pickford, Chris; Wu, Hua; Butler, Scott L

2009-12-01

A new small-molecule inhibitor class that targets virion maturation was identified from a human immunodeficiency virus type 1 (HIV-1) antiviral screen. PF-46396, a representative molecule, exhibits antiviral activity against HIV-1 laboratory strains and clinical isolates in T-cell lines and peripheral blood mononuclear cells (PBMCs). PF-46396 specifically inhibits the processing of capsid (CA)/spacer peptide 1 (SP1) (p25), resulting in the accumulation of CA/SP1 (p25) precursor proteins and blocked maturation of the viral core particle. Viral variants resistant to PF-46396 contain a single amino acid substitution in HIV-1 CA sequences (CAI201V), distal to the CA/SP1 cleavage site in the primary structure, which we demonstrate is sufficient to confer significant resistance to PF-46396 and 3-O-(3',3'-dimethylsuccinyl) betulinic acid (DSB), a previously described maturation inhibitor. Conversely, a single amino substitution in SP1 (SP1A1V), which was previously associated with DSB in vitro resistance, was sufficient to confer resistance to DSB and PF-46396. Further, the CAI201V substitution restored CA/SP1 processing in HIV-1-infected cells treated with PF-46396 or DSB. Our results demonstrate that PF-46396 acts through a mechanism that is similar to DSB to inhibit the maturation of HIV-1 virions. To our knowledge, PF-46396 represents the first small-molecule HIV-1 maturation inhibitor that is distinct in chemical class from betulinic acid-derived maturation inhibitors (e.g., DSB), demonstrating that molecules of diverse chemical classes can inhibit this mechanism.

Reactivity of Toluate Dioxygenase with Substituted Benzoates and Dioxygen

PubMed Central

Ge, Yong; Vaillancourt, Frédéric H.; Agar, Nathalie Y. R.; Eltis, Lindsay D.

2002-01-01

Toluate dioxygenase (TADO) of Pseudomonas putida mt-2 catalyzes the dihydroxylation of a broad range of substituted benzoates. The two components of this enzyme were hyperexpressed and anaerobically purified. Reconstituted TADO had a specific activity of 3.8 U/mg with m-toluate, and each component had a full complement of their respective Fe2S2 centers. Steady-state kinetics data obtained by using an oxygraph assay and by varying the toluate and dioxygen concentrations were analyzed by a compulsory order ternary complex mechanism. TADO had greatest specificity for m-toluate, displaying apparent parameters of KmA = 9 ± 1 μM, kcat = 3.9 ± 0.2 s−1, and KmO2 = 16 ± 2 μM (100 mM sodium phosphate, pH 7.0; 25°C), where KmO2 represents the Km for O2 and KmA represents the Km for the aromatic substrate. The enzyme utilized benzoates in the following order of specificity: m-toluate > benzoate ≃ 3-chlorobenzoate > p-toluate ≃ 4-chlorobenzoate ≫ o-toluate ≃ 2-chlorobenzoate. The transformation of each of the first five compounds was well coupled to O2 utilization and yielded the corresponding 1,2-cis-dihydrodiol. In contrast, the transformation of ortho-substituted benzoates was poorly coupled to O2 utilization, with >10 times more O2 being consumed than benzoate. However, the apparent Km of TADO for these benzoates was >100 μM, indicating that they do not effectively inhibit the turnover of good substrates. PMID:12107126

Molecular Docking and Pharmacological Investigations of Rivastigmine-Fluoxetine and Coumarin-Tacrine hybrids against Acetyl Choline Esterase.

PubMed

Babitha, Pallikkara Pulikkal; Sahila, Mohammed Marunnan; Bandaru, Srinivas; Nayarisseri, Anuraj; Sureshkumar, Sivanpillai

2015-01-01

The present AChE inhibitors have been successful in the treatment of Alzheimer׳s Diseases however suffers serious side effects. Therefore in this view, the present study was sought to identify compounds with appreciable pharmacological profile targeting AChE. Analogue of Rivastigmine and Fluoxetine hybrid synthesized by Toda et al, 2003 (dataset1), and Coumarin-Tacrine hybrids synthesized by Qi Sun et al (dataset2) formed the test compounds for the present pharmacological evaluation. p-cholorophenyl substituted Rivastigmine and Fluoxetine hybrid compound (26d) from dataset 1 and -OCH3 substitute Coumarin-Tacrine hybrids (1h) from dataset 2 demonstrated superior pharmacological profile. 26 d showed superior pharmacological profile comparison to the entire compounds in either dataset owing to its better electrostatic interactions and hydrogen bonding patterns. In order to identify still better compound with pharmacological profile than 26 d and 1h, virtual screening was performed. The best docked compound (PubCId: PubCid: 68874404) showed better affinity than its parent 26 d, however showed poor ADME profile and AMES toxicity. CHEMBL2391475 (PubCid: 71699632) similar to 1h had reduced affinity in comparison to its parent compound 1h. From, our extensive analysis involving binding affinity analysis, ADMET properties predictions and pharmacophoric mappings, we report p-cholorophenyl substituted rivastigmine and fluoxetine hybrid (26d) to be a potential candidate for AcHE inhibition which in addition can overcome narrow therapeutic window of present AChE inhibitors in clinical treatment of Alzheimer׳s disease. AD - Alzheimer׳s Disease, AChE - Acetyl Choline Estarase, OPLS - Optimized Potentials for Liquid Simulations, PDB - Protein Data Bank.

Healing bone lesion defects using injectable CaSO4 /CaPO4 -TCP bone graft substitute compared to cancellous allograft bone chips in a canine model.

PubMed

Hall, Deborah J; Turner, Thomas M; Urban, Robert M

2018-04-16

CaSO 4 /CaPO 4 -TCP bone graft substitute has been shown to be effective for treatment of bone lesion defects, but its mechanical, histological, and radiographic characteristics have not been studied in direct comparison with a conventional treatment such as cancellous allograft bone. Thirteen canines had a critical-size axial defect created bilaterally into the proximal humerus. CaSO 4 /CaPO 4 -TCP bone graft substitute (PRO-DENSE™, Wright Medical Technology) was injected into the defect in one humerus, and an equal volume of freeze-dried cancellous allograft bone chips was placed in the contralateral defect. The area fraction of new bone, residual graft, and fibrous tissue and the compressive strength and elastic modulus of bone within the defects were determined after 6, 13, or 26 weeks and correlated with radiographic changes. The data were analyzed using Friedman and Mann-Whitney tests. There was more bone in defects treated with the CaSO 4 /CaPO 4 -TCP bone graft substitute compared to defects treated with cancellous bone allograft at all three time points, and the difference at 13 weeks was significant (p = 0.025). The new bone was significantly stronger and stiffer in defects treated with the CaSO 4 /CaPO 4 -TCP bone graft substitute compared to defects treated with cancellous bone allograft at 13 (p = 0.046) and 26 weeks (p = 0.025). At 26 weeks, all defects treated with CaSO 4 /CaPO 4 -TCP bone graft substitute demonstrated complete healing with new bone, whereas healing was incomplete in all defects treated with cancellous allograft chips. The CaSO 4 /CaPO 4 -TCP bone graft substitute could provide faster and significantly stronger healing of bone lesions compared to the conventional treatment using freeze-dried cancellous allograft bone. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

Electronic characterization of defects in narrow gap semiconductors

NASA Technical Reports Server (NTRS)

Patterson, James D.

1994-01-01

We use a Green's function technique to calculate the position of deep defects in narrow gap semiconductors. We consider substitutional (including antisite), vacancy, and interstitial (self and foreign) deep defects. We also use perturbation theory to look at the effect of nonparabolic bands on shallow defect energies and find nonparabolicity can increase the binding by 10 percent or so. We consider mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS). For substitutional and interstitial defects we look at the situation with and without relaxation. For substitutional impurities in MCT, MZT, and MZS, we consider x (the concentration of Cd or Zn) in the range 0.1 less than x less than 0.3 and also consider appropriate x so E(sub g) = 0.1 eV for each of the three compounds. We consider several cation site s-like deep levels and anion site p-like levels. For E(sub g) = 0.1 eV, we also consider the effects of relaxation. Similar comments apply to the interstitial deep levels whereas no relaxation is considered for the ideal vacancy model. Relaxation effects can be greater for the interstitial than the substitutional cases. Specific results are given in figures and tables and comparison to experiment is made in a limited number of cases. We find, for example, that I, Se, S, Rn, and N are possible cation site, s-like deep levels in MCT and Zn and Mg are for anion site, p-like levels (both levels for substitutional cases). The corresponding cation and anion site levels for interstitial deep defects are (Au, Ag, Hg, Cd, Cu, Zn) and (N, Ar, O, F). For the substitutional cases we have some examples of relaxation moving the levels into the band gap, whereas for the interstitial case we have examples where relaxation moves it out of the band gap. Future work involves calculating the effects of charge state interaction and seeing the effect of relaxation on vacancy levels.

Evolution of TEM-type enzymes: biochemical and genetic characterization of two new complex mutant TEM enzymes, TEM-151 and TEM-152, from a single patient.

PubMed

Robin, Frédéric; Delmas, Julien; Schweitzer, Cédric; Tournilhac, Olivier; Lesens, Olivier; Chanal, Catherine; Bonnet, Richard

2007-04-01

Two clinical isolates of Escherichia coli, CF1179 and CF1295, were isolated from a patient hospitalized in the hematology unit of the University Hospital of Clermont-Ferrand, Clermont-Ferrand, France. They were resistant to penicillin-clavulanate combinations and to ceftazidime. The double-disk synergy test was positive only for isolate CF1179. Molecular comparison of the isolates showed that they were clonally related. E. coli recombinant strains exhibiting the resistance phenotype of the clinical strains were obtained by cloning. The clones corresponding to strains CF1179 and CF1295 produced TEM-type beta-lactamases with pI values of 5.7 and 5.3, respectively. Sequencing analysis revealed two novel blaTEM genes encoding closely related complex mutant TEM enzymes, designated TEM-151 (pI 5.3) and TEM-152 (pI 5.7). These two genes also harbored a new promoter region which presented a 9-bp deletion. The two novel beta-lactamases differed from the parental enzyme, TEM-1, by the substitution Arg164His, previously observed in extended-spectrum beta-lactamases (ESBLs), and by the substitutions Met69Val and Asn276Asp, previously observed in the inhibitor-resistant penicillinase TEM-36/IRT-7. They differed by two amino acid substitutions: TEM-152 harbored a Glu240Lys ESBL-type substitution and TEM-151 had an Ala284Gly substitution. Functional analysis of TEM-151 and TEM-152 showed that both enzymes had hydrolytic activity against ceftazidime (kcat, 5 and 16 s-1, respectively). TEM-152 was more resistant than TEM-151 to the inhibitor clavulanic acid (50% inhibitory concentrations, 1 versus 0.17 microM). These results confirm the evolution of TEM-type enzymes toward complex enzymes harboring the two kinds of substitutions which confer an extended spectrum of action against beta-lactam antibiotics and resistance to inhibitors.

Alternatives to Autologous Bone Graft in Alveolar Cleft Reconstruction: The State of Alveolar Tissue Engineering.

PubMed

Liang, Fan; Leland, Hyuma; Jedrzejewski, Breanna; Auslander, Allyn; Maniskas, Seija; Swanson, Jordan; Urata, Mark; Hammoudeh, Jeffrey; Magee, William

2018-05-01

Alveolar cleft reconstruction has historically relied on autologous iliac crest bone grafting (ICBG), but donor site morbidity, pain, and prolonged hospitalization have prompted the search for bone graft substitutes. The authors evaluated bone graft substitutes with the highest levels of evidence, and highlight the products that show promise in alveolar cleft repair and in maxillary augmentation. This comprehensive review guides the craniofacial surgeon toward safe and informed utilization of biomaterials in the alveolar cleft.A literature search was performed to identify in vitro human studies that fulfilled the following criteria: Level I or Level II of evidence, ≥30 subjects, and a direct comparison between a autologous bone graft and a bone graft substitute. A second literature search was performed that captured all studies, regardless of level of evidence, which evaluated bone graft substitutes for alveolar cleft repair or alveolar augmentation for dental implants. Adverse events for each of these products were tabulated as well.Sixteen studies featuring 6 bone graft substitutes: hydroxyapatite, demineralized bone matrix (DBM), β-tricalcium phosphate (TCP), calcium phosphate, recombinant human bone morphogenic protein-2 (rhBMP-2), and rhBMP7 fit the inclusion criteria for the first search. Through our second search, the authors found that DBM, TCP, rhBMP-2, and rhBMP7 have been studied most extensively in the alveolar cleft literature, though frequently in studies using less rigorous methodology (Level III evidence or below). rhBMP-2 was the best studied and showed comparable efficacy to ICBG in terms of volume of bone regeneration, bone density, and capacity to accommodate tooth eruption within the graft site. Pricing for products ranged from $290 to $3110 per 5 mL.The balance between innovation and safety is a complex process requiring constant vigilance and evaluation. Here, the authors profile several bone graft substitutes that demonstrate the most promise in alveolar cleft reconstruction.

Mapping the neutralizing epitopes on the glycoprotein of infectious haematopoietic necrosis virus, a fish rhabdovirus

USGS Publications Warehouse

Huang, C.; Chien, M.S.; Landolt, M.L.; Batts, W.; Winton, J.

1996-01-01

Twelve neutralizing monoclonal antibodies (MAbs) against the fish rhabdovirus, infectious haematopoietic necrosis virus (IHNV), were used to select 20 MAb escape mutants. The nucleotide sequence of the entire glycoprotein (G) gene was determined for six mutants representing differing cross-neutralization patterns and each had a single nucleotide change leading to a single amino acid substitution within one of three regions of the protein. These data were used to design nested PCR primers to amplify portions of the G gene of the 14 remaining mutants. When the PCR products from these mutants were sequenced, they also had single nucleotide substitutions coding for amino acid substitutions at the same, or nearby, locations. Of the 20 mutants for which all or part of the glycoprotein gene was sequenced, two MAbs selected mutants with substitutions at amino acids 230-231 (antigenic site I) and the remaining MAbs selected mutants with substitutions at amino acids 272-276 (antigenic site II). Two MAbs that selected mutants mapping to amino acids 272-276, selected other mutants that mapped to amino acids 78-81, raising the possibility that this portion of the N terminus of the protein was part of a discontinuous epitope defining antigenic site II. CLUSTAL alignment of the glycoproteins of rabies virus, vesicular stomatitis virus and IHNV revealed similarities in the location of the neutralizing epitopes and a high degree of conservation among cysteine residues, indicating that the glycoproteins of three different genera of animal rhabdoviruses may share a similar three-dimensional structure in spite of extensive sequence divergence.

Arylethynyl Substituted 9,lO-Anthraquinones: Tunable Stokes Shifts by Substitution and Solvent Polarity

NASA Technical Reports Server (NTRS)

Yang, Jinhua; Dass, Amala; Rawashdeh, Abdel-Monem M.; Sotiriou-Leventis, Chariklia; Panzner, Matthew J.; Tyson, Daniel S.; Kinder, James D.; Leventis, Nicholas

2004-01-01

2-Arylethynyl- and 2,6- and 2,7-diarylethynyl-substituted 9,lO-anthraquinones were synthesized via Sonogashira coupling reactions of 2-bromo-, 2,6-dibromo-, and 2,7-dibromo-9,10- anthraquinone with para-substituted phenylacetylenes. While the redox properties of those compounds are almost insensitive to substitution, their absorption maxima are linearly related to the Hammett constants with different slopes for electron donors and electron acceptors. ABI compounds are photoluminescent both in solution (quantum yields of emission <= 6 %), and as solids. The emission spectra have the characteristics of charge-transfer bands with large Stokes shifts (100-250 nm). The charge-transfer character of the emitting state is supported by large dipole moment differences between the ground and the excited state as concluded on the basis of molecular modeling and Lippert-Mataga correlations of the Stokes shifts with solvent polarity. Maximum Stokes shifts are attained by both electron-donating and -withdrawing groups. This is explained by a destabilization of the HOMO by electron donors and a stabilization of the LUMO by electron acceptors. X-ray crystallographic analysis of, for example, 2,7-bisphenylethynfl- 9,lO-anthraquinone reveals a monoclinic P21In space group and no indication for pi-overlap that would promote quenching, thus explaining emission from the solid state. Representative reduced forms of the title compounds were isolated as stable acetates of the corresponding dihydrs-9,10- anthraquinones. The emission of these compounds is blue-shifted relative to the parent oxidized forms and is attributed to internal transitions in the dihydro-9,lO-anthraquinone core.

Comparison of six bone-graft substitutes regarding to cell seeding efficiency, metabolism and growth behaviour of human mesenchymal stem cells (MSC) in vitro.

PubMed

Seebach, Caroline; Schultheiss, Judith; Wilhelm, Kerstin; Frank, Johannes; Henrich, Dirk

2010-07-01

Various synthetic bone-graft substitutes are used commercially as osteoconductive scaffolds in the treatment of bone defects and fractures. The role of bone-graft substitutes is changing from osteoconductive conduits for growth to an delivery system for biologic fracture treatments. Achieving optimal bone regeneration requires biologics (e.g. MSC) and using the correct scaffold incorporated into a local environment for bone regeneration. The need for an unlimited supply with high quality bone-graft substitutes continue to find alternatives for bone replacement surgery. This in vitro study investigates cell seeding efficiency, metabolism, gene expression and growth behaviour of MSC sown on six commercially clinical available bone-graft substitutes in order to define their biological properties: synthetic silicate-substituted porous hydroxyapatite (Actifuse ABX), synthetic alpha-TCP (Biobase), synthetic beta-TCP (Vitoss), synthetic beta-TCP (Chronos), processed human cancellous allograft (Tutoplast) and processed bovines hydroxyapatite ceramic (Cerabone). 250,000 MSC derived from human bone marrow (n=4) were seeded onto the scaffolds, respectively. On days 2, 6 and 10 the adherence of MSC (fluorescence microscopy) and cellular activity (MTT assay) were analysed. Osteogenic gene expression (cbfa-1) was analysed by RT-PCR and scanning electron microscopy was performed. The highest number of adhering cells was found on Tutoplast (e.g. day 6: 110.0+/-24.0 cells/microscopic field; p<0.05) followed by Chronos (47.5+/-19.5, p<0.05), Actifuse ABX (19.1+/-4.4), Biobase (15.7+/-9.9), Vitoss (8.8+/-8.7) and Cerabone (8.1+/-2.2). MSC seeded onto Tutoplast showed highest metabolic activity and gene expression of cbfa-1. These data are confirmed by scanning electron microscopy. The cell shapes varied from round-shaped cells to wide spread cells and cell clusters, depending on the bone-graft substitutes. Processed human cancellous allograft is a well-structured and biocompatible scaffold for ingrowing MSC in vitro. Of all other synthetical scaffolds, beta-tricalcium phosphate (Chronos) have shown the best growth behaviour for MSC. Our results indicate that various bone-graft substitutes influence cell seeding efficiency, metabolic activity and growth behaviour of MSC in different manners. We detected a high variety of cellular integration of MSC in vitro, which may be important for bony integration in the clinical setting. 2010 Elsevier Ltd. All rights reserved.

Chiral discrimination in diastereomeric salts of chlorine-substituted mandelic acid and phenylethylamine.

PubMed

He, Quan; Gomaa, Hassan; Rohani, Sohrab; Zhu, Jesse; Jennings, Michael

2010-08-01

The crystal structures of diastereomeric salts of chloromandelic acid and phenylethylamine were determined and are presented herein. The structure comparison between less soluble salts and more soluble salts shows that weak interactions such as CH/pi interactions and van der Waals gain importance and contribute to chiral recognition when the hydrogen bonding patterns are very similar. Copyright 2010 Wiley-Liss, Inc.

Design, synthesis, and evaluation of a novel series of alpha-substituted phenylpropanoic acid derivatives as human peroxisome proliferator-activated receptor (PPAR) alpha/delta dual agonists for the treatment of metabolic syndrome.

PubMed

Kasuga, Jun-ichi; Yamasaki, Daisuke; Araya, Yoko; Nakagawa, Aya; Makishima, Makoto; Doi, Takefumi; Hashimoto, Yuichi; Miyachi, Hiroyuki

2006-12-15

A series of alpha-alkyl-substituted phenylpropanoic acids was prepared as dual agonists of peroxisome proliferator-activated receptors alpha and delta (PPARalpha/delta). Structure-activity relationship studies indicated that the shape of the linking group and the shape of the substituent at the distal benzene ring play key roles in determining the potency and the selectivity of PPAR subtype transactivation. Structure-activity relationships among the amide series (10) and the reversed amide series (13) are similar, but not identical, especially in the case of the compounds bearing a bulky hydrophobic substituent at the distal benzene ring, indicating that the hydrophobic tail part of the molecules in these two series binds at somewhat different positions in the large binding pocket of PPAR. alpha-Alkyl-substituted phenylpropanoic acids of (S)-configuration were identified as potent human PPARalpha/delta dual agonists. Representative compounds exhibited marked nuclear receptor selectivity for PPARalpha and PPARdelta. Subtype-selective PPAR activation was also examined by analysis of the mRNA expression of PPAR-regulated genes.

8-Substituted Pyrido[3,4-d]pyrimidin-4(3H)-one Derivatives As Potent, Cell Permeable, KDM4 (JMJD2) and KDM5 (JARID1) Histone Lysine Demethylase Inhibitors

PubMed Central

2016-01-01

We report the discovery of N-substituted 4-(pyridin-2-yl)thiazole-2-amine derivatives and their subsequent optimization, guided by structure-based design, to give 8-(1H-pyrazol-3-yl)pyrido[3,4-d]pyrimidin-4(3H)-ones, a series of potent JmjC histone N-methyl lysine demethylase (KDM) inhibitors which bind to Fe(II) in the active site. Substitution from C4 of the pyrazole moiety allows access to the histone peptide substrate binding site; incorporation of a conformationally constrained 4-phenylpiperidine linker gives derivatives such as 54j and 54k which demonstrate equipotent activity versus the KDM4 (JMJD2) and KDM5 (JARID1) subfamily demethylases, selectivity over representative exemplars of the KDM2, KDM3, and KDM6 subfamilies, cellular permeability in the Caco-2 assay, and, for 54k, inhibition of H3K9Me3 and H3K4Me3 demethylation in a cell-based assay. PMID:26741168

Tuning the hybridization and magnetic ground state of electron and hole doped CeOs2Al10 : An x-ray spectroscopy study

NASA Astrophysics Data System (ADS)

Chen, Kai; Sundermann, Martin; Strigari, Fabio; Kawabata, Jo; Takabatake, Toshiro; Tanaka, Arata; Bencok, Peter; Choueikani, Fadi; Severing, Andrea

2018-04-01

Here we present linear and circular polarized soft x-ray absorption spectroscopy (XAS) data at the Ce M4 ,5 edges of the electron (Ir) and hole-doped (Re) Kondo semiconductor CeOs2Al10 . Both substitutions have a strong impact on the unusual high Néel temperature TN=28.5 K, and also the direction of the ordered moment in case of Ir. The substitution dependence of the linear dichroism is weak thus validating the crystal-field description of CeOs2Al10 being representative for the Re and Ir substituted compounds. The impact of electron and hole doping on the hybridization between conduction and 4 f electrons is related to the amount of f0 in the ground state and reduction of x-ray magnetic circular dichroism. A relationship of c f -hybridization strength and enhanced TN is discussed. The direction and doping dependence of the circular dichroism strongly supports the idea of strong Kondo screening along the crystallographic a direction.

Shifts in the evolutionary rate and intensity of purifying selection between two Brassica genomes revealed by analyses of orthologous transposons and relics of a whole genome triplication.

PubMed

Zhao, Meixia; Du, Jianchang; Lin, Feng; Tong, Chaobo; Yu, Jingyin; Huang, Shunmou; Wang, Xiaowu; Liu, Shengyi; Ma, Jianxin

2013-10-01

Recent sequencing of the Brassica rapa and Brassica oleracea genomes revealed extremely contrasting genomic features such as the abundance and distribution of transposable elements between the two genomes. However, whether and how these structural differentiations may have influenced the evolutionary rates of the two genomes since their split from a common ancestor are unknown. Here, we investigated and compared the rates of nucleotide substitution between two long terminal repeats (LTRs) of individual orthologous LTR-retrotransposons, the rates of synonymous and non-synonymous substitution among triplicated genes retained in both genomes from a shared whole genome triplication event, and the rates of genetic recombination estimated/deduced by the comparison of physical and genetic distances along chromosomes and ratios of solo LTRs to intact elements. Overall, LTR sequences and genic sequences showed more rapid nucleotide substitution in B. rapa than in B. oleracea. Synonymous substitution of triplicated genes retained from a shared whole genome triplication was detected at higher rates in B. rapa than in B. oleracea. Interestingly, non-synonymous substitution was observed at lower rates in the former than in the latter, indicating shifted densities of purifying selection between the two genomes. In addition to evolutionary asymmetry, orthologous genes differentially regulated and/or disrupted by transposable elements between the two genomes were also characterized. Our analyses suggest that local genomic and epigenomic features, such as recombination rates and chromatin dynamics reshaped by independent proliferation of transposable elements and elimination between the two genomes, are perhaps partially the causes and partially the outcomes of the observed inter-specific asymmetric evolution. © 2013 Purdue University The Plant Journal © 2013 John Wiley & Sons Ltd.

Direct comparison of oligochaete erythrocruorins as potential blood substitutes

PubMed Central

Zimmerman, Devon; DiIusto, Matthew; Dienes, Jack; Abdulmalik, Osheiza

2017-01-01

Abstract While many blood substitutes are based on mammalian hemoglobins (e.g., human hemoglobin, HbA), the naturally extracellular hemoglobins of invertebrates (a.k.a. erythrocruorins, Ecs) are intriguing alternative oxygen carriers. Specifically, the erythrocruorin of Lumbricus terrestris has been shown to effectively deliver oxygen in mice and rats without the negative side effects observed with HbA. In this study, the properties of six oligochaete Ecs (Lumbricus terrestris, Eisenia hortensis, Eisenia fetida, Eisenia veneta, Eudrilus eugeniae, and Amynthas gracilis) were compared in vitro to identify the most promising blood substitute candidate(s). Several metrics were used to compare the Ecs, including their oxidation rates, dissociation at physiological pH, thermal stability, and oxygen transport characteristics. Overall, the Ecs of Lumbricus terrestris (LtEc) and Eisenia fetida (EfEc) were identified as promising candidates, since they demonstrated high thermal and oligomeric stability, while also exhibiting relatively low oxidation rates. Interestingly, the O2 affinity of LtEc (P 50 = 26.25 mmHg at 37 °C) was also observed to be uniquely lower than EfEc and all of the other Ecs (P 50 = 9.29–13.62 mmHg). Subsequent alignment of the primary sequences of LtEc and EfEc revealed several significant amino acid substitutions within the D subunit interfaces that may be responsible for this significant change in O2 affinity. Nonetheless, these results show that LtEc and EfEc are promising potential blood substitutes that are resistant to oxidation and denaturation, but additional experiments will need to be conducted to determine their safety, efficacy, and the effects of their disparate oxygen affinities in vivo. PMID:29313031

A plasmid borne, functionally novel glycoside hydrolase family 30 subfamily 8 endoxylanase from solventogenic Clostridium

PubMed Central

Dietrich, Diane; Crooks, Casey; Balogun, Peter; deSerrano, Vesna; Pozharski, Edwin; Smith, James Kennon; Bales, Elizabeth; Hurlbert, Jason

2018-01-01

Glycoside hydrolase family 30 subfamily 8 (GH30-8) β-1,4-endoxylanases are known for their appendage-dependent function requiring recognition of an α-1,2-linked glucuronic acid (GlcA) common to glucuronoxylans for hydrolysis. Structural studies have indicated that the GlcA moiety of glucuronoxylans is coordinated through six hydrogen bonds and a salt bridge. These GlcA-dependent endoxylanases do not have significant activity on xylans that do not bear GlcA substitutions such as unsubstituted linear xylooligosaccharides or cereal bran arabinoxylans. In the present study, we present the structural and biochemical characteristics of xylanase 30A from Clostridium acetobutylicum (CaXyn30A) which was originally selected for study due to predicted structural differences within the GlcA coordination loops. Amino acid sequence comparisons indicated that this Gram-positive-derived GH30-8 more closely resembles Gram-negative derived forms of these endoxylanases: a hypothesis borne out in the developed crystallographic structure model of the CaXyn30A catalytic domain (CaXyn30A-CD). CaXyn30A-CD hydrolyzes xylans to linear and substituted oligoxylosides showing the greatest rate with the highly arabinofuranose (Araf)-substituted cereal arabinoxylans. CaXyn30A-CD hydrolyzes xylooligosaccharides larger than xylotriose and shows an increased relative rate of hydrolysis for xylooligosaccharides containing α-1,2-linked arabinofuranose substitutions. Biochemical analysis confirms that CaXyn30A benefits from five xylose-binding subsites which extend from the −3 subsite to the +2 subsite of the binding cleft. These studies indicate that CaXyn30A is a GlcA-independent endoxylanase that may have evolved for the preferential recognition of α-1,2-Araf substitutions on xylan chains. PMID:29626157

Emergence of Avian Influenza Viruses with Enhanced Transcription Activity by a Single Amino Acid Substitution in the Nucleoprotein during Replication in Chicken Brains ▿

PubMed Central

Tada, Tatsuya; Suzuki, Koutaro; Sakurai, Yu; Kubo, Masanori; Okada, Hironao; Itoh, Toshihiro; Tsukamoto, Kenji

2011-01-01

To explore the genetic basis of the pathogenesis and adaptation of avian influenza viruses (AIVs) to chickens, the A/duck/Yokohama/aq10/2003 (H5N1) (DkYK10) virus was passaged five times in the brains of chickens. The brain-passaged DkYK10-B5 caused quick death of chickens through rapid and efficient replication in tissues, accompanied by severe apoptosis. Genome sequence comparison of two viruses identified a single amino acid substitution at position 109 in NP from isoleucine to threonine (NP I109T). By analyzing viruses constructed by the reverse-genetic method, we established that the NP I109T substitution also contributed to increased viral replication and polymerase activity in chicken embryo fibroblasts, but not in duck embryo fibroblasts. Real-time RT-PCR analysis demonstrated that the NP I109T substitution enhances mRNA synthesis quickly and then cRNA and viral RNA (vRNA) synthesis slowly. Next, to determine the mechanism underlying the appearance of the NP I109T substitution during passages, four H5N1 highly pathogenic AIVs (HPAIVs) were passaged in the lungs and brains of chicken embryos. Single-nucleotide polymorphism analysis, together with a database search, suggests that the NP I109T mutation would be induced frequently during replication of HPAIVs in brains, but not in lungs. These results demonstrate that the amino acid at position 109 in NP enhances viral RNA synthesis and the pathogenicity of highly pathogenic avian influenza viruses in chickens and that the NP mutation emerges quickly during replication of the viruses in chicken brains. PMID:21795332

Exergetic life cycle assessment of hydrogen production from renewables

NASA Astrophysics Data System (ADS)

Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

Life cycle assessment is extended to exergetic life cycle assessment and used to evaluate the exergy efficiency, economic effectiveness and environmental impact of producing hydrogen using wind and solar energy in place of fossil fuels. The product hydrogen is considered a fuel for fuel cell vehicles and a substitute for gasoline. Fossil fuel technologies for producing hydrogen from natural gas and gasoline from crude oil are contrasted with options using renewable energy. Exergy efficiencies and greenhouse gas and air pollution emissions are evaluated for all process steps, including crude oil and natural gas pipeline transportation, crude oil distillation and natural gas reforming, wind and solar electricity generation, hydrogen production through water electrolysis, and gasoline and hydrogen distribution and utilization. The use of wind power to produce hydrogen via electrolysis, and its application in a fuel cell vehicle, exhibits the lowest fossil and mineral resource consumption rate. However, the economic attractiveness, as measured by a "capital investment effectiveness factor," of renewable technologies depends significantly on the ratio of costs for hydrogen and natural gas. At the present cost ratio of about 2 (per unit of lower heating value or exergy), capital investments are about five times lower to produce hydrogen via natural gas rather than wind energy. As a consequence, the cost of wind- and solar-based electricity and hydrogen is substantially higher than that of natural gas. The implementation of a hydrogen fuel cell instead of an internal combustion engine permits, theoretically, an increase in a vehicle's engine efficiency of about of two times. Depending on the ratio in engine efficiencies, the substitution of gasoline with "renewable" hydrogen leads to (a) greenhouse gas (GHG) emissions reductions of 12-23 times for hydrogen from wind and 5-8 times for hydrogen from solar energy, and (b) air pollution (AP) emissions reductions of 38-76 times for hydrogen from wind and 16-32 times for hydrogen from solar energy. By comparison, substitution of gasoline with hydrogen from natural gas allows reductions in GHG emissions only as a result of the increased efficiency of a fuel cell engine, and a reduction of AP emissions of 2.5-5 times. These data suggest that "renewable" hydrogen represents a potential long-term solution to many environmental problems.

Mechanistic Insights from the Crystal Structure of Bacillus subtilis o-Succinylbenzoyl-CoA Synthetase Complexed with the Adenylate Intermediate.

PubMed

Chen, Yaozong; Jiang, Yiping; Guo, Zhihong

2016-12-06

o-Succinylbenzoyl-CoA (OSB-CoA) synthetase, or MenE, catalyzes an essential step in vitamin K biosynthesis and is a valuable drug target. Like many other adenylating enzymes, it changes its structure to accommodate substrate binding, catalysis, and product release along the path of a domain alternation catalytic mechanism. We have determined the crystal structure of its complex with the adenylation product, o-succinylbenzoyl-adenosine monophosphate (OSB-AMP), and captured a new postadenylation state. This structure presents unique features such as a strained conformation for the bound adenylate intermediate to indicate that it represents the enzyme state after completion of the adenylation reaction but before release of the C domain in its transition to the thioesterification conformation. By comparison to the ATP-bound preadenylation conformation, structural changes are identified in both the reactants and the active site to allow inference about how these changes accommodate and facilitate the adenylation reaction and to directly support an in-line backside attack nucleophilic substitution mechanism for the first half-reaction. Mutational analysis suggests that the conserved His196 plays an important role in desolvation of the active site rather than stabilizing the transition state of the adenylation reaction. In addition, comparison of the new structure with a previously determined OSB-AMP-bound structure of the same enzyme allows us to propose a release mechanism of the C domain in its alteration to form the thioesterification conformation. These findings allow us to better understand the domain alternation catalytic mechanism of MenE as well as many other adenylating enzymes.

UV-Visible Spectra of PAHs and Derivatives Seeded in Supersonic Jet. Astrophysical Implications

NASA Astrophysics Data System (ADS)

Salma, Bejaoui; Salama, Farid

2018-06-01

Laboratory absorption spectra of Polycyclic Aromatic Hydrocarbons (PAHs) and PAH derivatives measured under astrophysical relevant conditions are crucial to test the PAHs-DIBs hypothesis as well as the PAH model for the IR emission bands. Our dedicated experimental setup on the COsmic SImulation Chamber (COSmIC) provides an excellent platform to study neutral and ionized PAHs under the low temperature and pressure conditions that are representative of interstellar environments [1]. In this work, we study the effect of the substitution of CH bond(s) by a nitrogen atom(s) on the electronic spectra of phenanthrene. The electronic transitions associated with the lower excited states of neutral phenanthrene (C14H10) and phenanthridine (C13H9N) are measured in gas phase in the 315-345 nm region. Molecules are seeded in a supersonic expansion of argon gas and the absorption spectra are measured using the Cavity Ring Down Spectroscopy (CRDS) technique. Additional measurements of the absorption spectra of phenanthrene, phenantridine and 1,10-phenanthroline (C12H8N2) isolated in 10 K argon matrices are also performed. The comparison between the CRDS spectra with the absorption of the matrix-isolated molecules highlight the matrix-induced perturbations in band position, profiles and broadening and illustrates the need of gas phase measurements for more accurate comparisons with astronomical spectra.[1] Salama, F., Galazutdinov, G., Krelowski, et al. ApJ 728, 154[FS1] (2011).[2] A. Tielens, ApJ 526 Pt 1265–273 (2008),Acknowledgements: This research is supported by the APRA Program of NASA SMD

Importance of Tensile Strength on the Shear Behavior of Discontinuities

NASA Astrophysics Data System (ADS)

Ghazvinian, A. H.; Azinfar, M. J.; Geranmayeh Vaneghi, R.

2012-05-01

In this study, the shear behavior of discontinuities possessing two different rock wall types with distinct separate compressive strengths was investigated. The designed profiles consisted of regular artificial joints molded by five types of plaster mortars, each representing a distinct uniaxial compressive strength. The compressive strengths of plaster specimens ranged from 5.9 to 19.5 MPa. These specimens were molded considering a regular triangular asperity profile and were designed so as to achieve joint walls with different strength material combinations. The results showed that the shear behavior of discontinuities possessing different joint wall compressive strengths (DDJCS) tested under constant normal load (CNL) conditions is the same as those possessing identical joint wall strengths, but the shear strength of DDJCS is governed by minor joint wall compressive strength. In addition, it was measured that the predicted values obtained by Barton's empirical criterion are greater than the experimental results. The finding indicates that there is a correlation between the joint roughness coefficient (JRC), normal stress, and mechanical strength. It was observed that the mode of failure of asperities is either pure tensile, pure shear, or a combination of both. Therefore, Barton's strength criterion, which considers the compressive strength of joint walls, was modified by substituting the compressive strength with the tensile strength. The validity of the modified criterion was examined by the comparison of the predicted shear values with the laboratory shear test results reported by Grasselli (Ph.D. thesis n.2404, Civil Engineering Department, EPFL, Lausanne, Switzerland, 2001). These comparisons infer that the modified criterion can predict the shear strength of joints more precisely.

Independent Emergence of the Cosmopolitan Asian Chikungunya Virus, Philippines 2012.

PubMed

Tan, Kim-Kee; Sy, Ava Kristy D; Tandoc, Amado O; Khoo, Jing-Jing; Sulaiman, Syuhaida; Chang, Li-Yen; AbuBakar, Sazaly

2015-07-23

Outbreaks involving the Asian genotype Chikungunya virus (CHIKV) caused over one million infections in the Americas recently. The outbreak was preceded by a major nationwide outbreak in the Philippines. We examined the phylogenetic and phylogeographic relationships of representative CHIKV isolates obtained from the 2012 Philippines outbreak with other CHIKV isolates collected globally. Asian CHIKV isolated from the Philippines, China, Micronesia and Caribbean regions were found closely related, herein denoted as Cosmopolitan Asian CHIKV (CACV). Three adaptive amino acid substitutions in nsP3 (D483N), E1 (P397L) and E3 (Q19R) were identified among CACV. Acquisition of the nsP3-483N mutation in Compostela Valley followed by E1-397L/E3-19R in Laguna preceded the nationwide spread in the Philippines. The China isolates possessed two of the amino acid substitutions, nsP3-D483N and E1-P397L whereas the Micronesian and Caribbean CHIKV inherited all the three amino acid substitutions. The unique amino acid substitutions observed among the isolates suggest multiple independent virus dissemination events. The possible biological importance of the specific genetic signatures associated with the rapid global of the virus is not known and warrant future in-depth study and epidemiological follow-up. Molecular evidence, however, supports the Philippines outbreak as the possible origin of the CACV.

Independent Emergence of the Cosmopolitan Asian Chikungunya Virus, Philippines 2012

PubMed Central

Tan, Kim-Kee; Sy, Ava Kristy D.; Tandoc, Amado O.; Khoo, Jing-Jing; Sulaiman, Syuhaida; Chang, Li-Yen; AbuBakar, Sazaly

2015-01-01

Outbreaks involving the Asian genotype Chikungunya virus (CHIKV) caused over one million infections in the Americas recently. The outbreak was preceded by a major nationwide outbreak in the Philippines. We examined the phylogenetic and phylogeographic relationships of representative CHIKV isolates obtained from the 2012 Philippines outbreak with other CHIKV isolates collected globally. Asian CHIKV isolated from the Philippines, China, Micronesia and Caribbean regions were found closely related, herein denoted as Cosmopolitan Asian CHIKV (CACV). Three adaptive amino acid substitutions in nsP3 (D483N), E1 (P397L) and E3 (Q19R) were identified among CACV. Acquisition of the nsP3-483N mutation in Compostela Valley followed by E1-397L/E3-19R in Laguna preceded the nationwide spread in the Philippines. The China isolates possessed two of the amino acid substitutions, nsP3-D483N and E1-P397L whereas the Micronesian and Caribbean CHIKV inherited all the three amino acid substitutions. The unique amino acid substitutions observed among the isolates suggest multiple independent virus dissemination events. The possible biological importance of the specific genetic signatures associated with the rapid global of the virus is not known and warrant future in-depth study and epidemiological follow-up. Molecular evidence, however, supports the Philippines outbreak as the possible origin of the CACV. PMID:26201250

On the use of Lineal Energy Measurements to Estimate Linear Energy Transfer Spectra

NASA Technical Reports Server (NTRS)

Adams, David A.; Howell, Leonard W., Jr.; Adam, James H., Jr.

2007-01-01

This paper examines the error resulting from using a lineal energy spectrum to represent a linear energy transfer spectrum for applications in the space radiation environment. Lineal energy and linear energy transfer spectra are compared in three diverse but typical space radiation environments. Different detector geometries are also studied to determine how they affect the error. LET spectra are typically used to compute dose equivalent for radiation hazard estimation and single event effect rates to estimate radiation effects on electronics. The errors in the estimations of dose equivalent and single event rates that result from substituting lineal energy spectra for linear energy spectra are examined. It is found that this substitution has little effect on dose equivalent estimates in interplanetary quiet-time environment regardless of detector shape. The substitution has more of an effect when the environment is dominated by solar energetic particles or trapped radiation, but even then the errors are minor especially if a spherical detector is used. For single event estimation, the effect of the substitution can be large if the threshold for the single event effect is near where the linear energy spectrum drops suddenly. It is judged that single event rate estimates made from lineal energy spectra are unreliable and the use of lineal energy spectra for single event rate estimation should be avoided.

How well do you see what you hear? The acuity of visual-to-auditory sensory substitution

PubMed Central

Haigh, Alastair; Brown, David J.; Meijer, Peter; Proulx, Michael J.

2013-01-01

Sensory substitution devices (SSDs) aim to compensate for the loss of a sensory modality, typically vision, by converting information from the lost modality into stimuli in a remaining modality. “The vOICe” is a visual-to-auditory SSD which encodes images taken by a camera worn by the user into “soundscapes” such that experienced users can extract information about their surroundings. Here we investigated how much detail was resolvable during the early induction stages by testing the acuity of blindfolded sighted, naïve vOICe users. Initial performance was well above chance. Participants who took the test twice as a form of minimal training showed a marked improvement on the second test. Acuity was slightly but not significantly impaired when participants wore a camera and judged letter orientations “live”. A positive correlation was found between participants' musical training and their acuity. The relationship between auditory expertise via musical training and the lack of a relationship with visual imagery, suggests that early use of a SSD draws primarily on the mechanisms of the sensory modality being used rather than the one being substituted. If vision is lost, audition represents the sensory channel of highest bandwidth of those remaining. The level of acuity found here, and the fact it was achieved with very little experience in sensory substitution by naïve users is promising. PMID:23785345

Insights into the Hydrogen-Atom Transfer of the Blue Aroxyl.

PubMed

Bächle, Josua; Marković, Marijana; Kelterer, Anne-Marie; Grampp, Günter

2017-10-19

An experimental and theoretical study on hydrogen-atom transfer dynamics in the hydrogen-bonded substituted phenol/phenoxyl complex of the blue aroxyl (2,4,6-tri-tert-butylphenoxyl) is presented. The experimental exchange dynamics is determined in different organic solvents from the temperature-dependent alternating line-width effect in the continuous-wave ESR spectrum. From bent Arrhenius plots, effective tunnelling contributions with parallel heavy-atom motion are concluded. To clarify the transfer mechanism, reaction paths for different conformers of the substituted phenol/phenoxyl complex are modelled theoretically. Various DFT and post-Hartree-Fock methods including multireference methods are applied. From the comparison of experimental and theoretical data it is concluded that the system favours concerted hydrogen-atom transfer along a parabolic reaction path caused by heavy-atom motion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bi-enhanced N incorporation in GaAsNBi alloys

DOE PAGES

Occena, J.; Jen, T.; Rizzi, E. E.; ...

2017-06-12

We have examined the influence of bismuth (Bi) and nitrogen (N) fluxes on N and Bi incorporation during molecular-beam epitaxy of GaAs 1-x-yN xBi y alloys. The incorporation of Bi is found to be independent of N flux, while the total N incorporation and the fraction of N atoms occupying non-substitutional lattice sites increase with increasing Bi flux. A comparison of channeling nuclear reaction analysis along the [100], [110], and [111] directions with Monte Carlo-Molecular Dynamics simulations indicates that the non-substitutional N primarily incorporate as (N-As) As interstitial complexes. We discuss the influence of Bi adatoms on the formation ofmore » arsenic-terminated [110]-oriented step-edges and the resulting enhancement in total N incorporation via the formation of additional (N-As) As.« less

Selenium-substituted polymers for improved photovoltaic performance.

PubMed

Yu, Jiangsheng; Ding, Guanqun; Hai, Jiefeng; Zhu, Enwei; Yin, Xinxing; Xu, Zhongsheng; Zhou, Baojing; Zhang, Fujun; Ma, Wanli; Tang, Weihua

2016-03-21

Four isostructural donor-acceptor alternating polymers of benzodithiophene (BDT)/naphthodifuran (NDF) and benzoselenadiazole (BSe)/benzothiadiazole (BT) have been developed and evaluated for organic photovoltaics. The substitution of one-atom (Se for S) in the accepting units exerts remarkable impact on the optoelectronic properties of polymers. Extended absorption, narrowed bandgap and higher HOMO energy levels were observed for Se-containing polymers in comparison to their S-containing counterparts. Theoretical calculations confirmed the measurable effect on energy levels as found in experimental studies. Bulk-heterojuction solar cells based on the BDT-BSe copolymer and [6,6]-phenyl-C71-butyric acid methyl ester (1 : 2, w/w) blend films deliver the best PCE of 5.40%. BSe-based polymers showed enhanced photovoltaic performances than BT-based polymers. The device performance is found to be strongly dependent on the processing conditions and morphology of the active layers.

Synthesis of highly substituted 2,3-dihydropyrimido[4,5-d]pyrimidin-4(1H)-ones from 4,6-dichloro-5-formylpyrimidine, amines and aldehydes.

PubMed

Xiang, Jinbao; Geng, Chao; Yi, Lang; Dang, Qun; Bai, Xu

2011-11-01

A practical strategy was developed for the preparation of highly substituted 2,3-dihydropyrimido[4,5-d]pyrimidin-4(1H)-ones from 4,6-dichloro-5-formylpyrimidine, primary amines, and aldehydes. The key step for this synthesis entails a cyclization reaction involving an intramolecular amide addition to an iminium intermediate formed in situ from 4-amino-pyrimidine-5-carboxamide 2 and aldehydes to form the pyrimido[4,5-d]pyrimidine core with a strategically placed 5-Cl group for further derivatization. The utility of this methodology was demonstrated through the preparation of a 27-membered library of representative 2,3-dihydropyrimido[4,5-d]pyrimidin-4(1H)-ones in moderate to good yields.

Oxidation and corrosion behavior of modified-composition, low-chromium 304 stainless steel alloys

NASA Technical Reports Server (NTRS)

Stephens, J. R.; Barrett, C. A.

1977-01-01

The effects of substituting less strategic elements than Cr on the oxidation and corrosion resistance of AISI 304 stainless steel were investigated. Cyclic oxidation resistance was evaluated at 870 C. Corrosion resistance was determined by exposure of specimens to a boiling copper-rich solution of copper sulfate and sulfuric acid. Alloy substitutes for Cr included Al, Mn, Mo, Si, Ti, V, Y, and misch metal. A level of about 12% Cr was the minimum amount of Cr required for adequate oxidation and corrosion resistance in the modified composition 304 stainless steels. This represents a Cr saving of at least 33%. Two alloys containing 12% Cr and 2% Al plus 2% Mo and 12% Cr plus 2.65% Si were identified as most promising for more detailed evaluation.

40 CFR 419.33 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TOC) based upon an analysis of any single grab or composite sample. (2) If contaminated runoff is... which exceeds 110 mg/l TOC is not commingled or treated with any other type of wastewater, the quantity... (1,000 ppm), the permitting authority may substitute TOC as a parameter in lieu of COD. A TOC...

40 CFR 419.53 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TOC) based upon an analysis of any single grab or composite sample. (2) If contaminated runoff is... which exceeds 110 mg/l TOC is not commingled or treated with any other type of wastewater, the quantity... (1,000 ppm), the permitting authority may substitute TOC as a parameter in lieu of COD. A TOC...

40 CFR 419.23 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TOC) based upon an analysis of any single grab or composite sample. (2) If contaminated runoff is... which exceeds 110 mg/l TOC is not commingled or treated with any other type of wastewater, the quantity... (1,000 ppm), the permitting authority may substitute TOC as a parameter in lieu of COD. A TOC...

POST-HIGH SCHOOL CURRICULUM FOR THE GRAIN, FEED, SEED AND FARM SUPPLY INDUSTRY.

ERIC Educational Resources Information Center

CLARK, RAYMOND M.; OLIVER, ALVIN E.

A COMMITTEE OF EDUCATION AND INDUSTRY REPRESENTATIVES RECOMMENDED 20 ESSENTIAL AND THREE SUBSTITUTE COURSES FOR A 2-YEAR POST-HIGH SCHOOL PROGRAM FOR TRAINING YOUNG MEN FOR THE NATIONAL GRAIN, FEED, SEED, AND FARM SUPPLY INDUSTRY. SOME ESSENTIAL COURSES WERE (1) SOIL SCIENCE I AND II, (2) CROP PRODUCTION, (3) APPLIED ANIMAL BIOCHEMISTRY, (4)…

Medical research in emergency research in the European Union member states: tensions between theory and practice.

PubMed

Kompanje, Erwin J O; Maas, Andrew I R; Menon, David K; Kesecioglu, Jozef

2014-04-01

In almost all of the European Union member states, prior consent by a legal representative is used as a substitute for informed patient consent for non-urgent medical research. Deferred (patient and/or proxy) consent is accepted as a substitute in acute emergency research in approximately half of the member states. In 12 European Union member states emergency research is not mentioned in national law. Medical research in the European Union is covered by the Clinical Trial Directive 2001/20/EC. A proposal for a regulation by the European Commission is currently being examined by the European Parliament and the Council and will replace Directive 2001/20/EC. Deferred patient and/or proxy consent is allowed in the proposed regulation, but does not fit completely in the practice of emergency research. For example, deferred consent is only possible when legal representatives are not available. This criterion will delay inclusion of patients in acute life-threatening conditions in short time frames. As the regulation shall be binding in its entirety in all member states, emergency research in acute situations is still not possible as it should be.

Worldwide Spread of Dengue Virus Type 1

PubMed Central

Villabona-Arenas, Christian Julián; Zanotto, Paolo Marinho de Andrade

2013-01-01

Background DENV-1 is one of the four viral serotypes that causes Dengue, the most common mosquito-borne viral disease of humans. The prevalence of these viruses has grown in recent decades and is now present in more than 100 countries. Limited studies document the spread of DENV-1 over the world despite its importance for human health. Methodology/Principal Findings We used representative DENV-1 envelope gene sequences to unravel the dynamics of viral diffusion under a Bayesian phylogeographic approach. Data included strains from 45 distinct geographic locations isolated from 1944 to 2009. The estimated mean rate of nucleotide substitution was 6.56×10−4 substitutions/site/year. The larger genotypes (I, IV and V) had a distinctive phylogenetic structure and since 1990 they experienced effective population size oscillations. Thailand and Indonesia represented the main sources of strains for neighboring countries. Besides, Asia broadcast lineages into the Americas and the Pacific region that diverged in isolation. Also, a transmission network analysis revealed the pivotal role of Indochina in the global diffusion of DENV-1 and of the Caribbean in the diffusion over the Americas. Conclusions/Significance The study summarizes the spatiotemporal DENV-1 worldwide spread that may help disease control. PMID:23675416

Nutritional Attributes, Substitutability, Scalability, and Environmental Intensity of an Illustrative Subset of Current and Future Protein Sources for Aquaculture Feeds: Joint Consideration of Potential Synergies and Trade-offs.

PubMed

Pelletier, Nathan; Klinger, Dane H; Sims, Neil A; Yoshioka, Janice-Renee; Kittinger, John N

2018-05-15

Aquaculture is anticipated to play an increasingly important role in global food security because it may represent one of the best opportunities to increase the availability of healthy animal protein in the context of resource and environmental constraints. However, the growth and sustainability of the aquaculture industry faces important bottlenecks with respect to feed resources, which may be derived from diverse sources. Here, using a small but representative subset of potential aquafeed inputs (which we selected to highlight a range of relevant attributes), we review a core suite of considerations that need to be accommodated in concert in order to overcome key bottlenecks to the continued development and expansion of the aquaculture industry. Specifically, we evaluate the nutritional attributes, substitutability, scalability, and resource and environmental intensity of each input. On this basis, we illustrate a range of potential synergies and trade-offs within and across attributes that are characteristic of ingredient types. We posit that the recognition and management of such synergies and trade-offs is imperative to satisfying the multi-objective decision-making associated with sustainable increases in future aquaculture production.

Chewing gum--facts and fiction: a review of gum-chewing and oral health.

PubMed

Imfeld, T

1999-01-01

The world market for chewing gum is estimated to be 560,000 tons per year, representing approximately US $5 billion. Some 374 billion pieces of chewing gum are sold worldwide every year, representing 187 billion hours of gum-chewing if each piece of gum is chewed for 30 minutes. Chewing gum can thus be expected to have an influence on oral health. The labeling of sugar-substituted chewing gum as "safe for teeth" or "tooth-friendly" has been proven beneficial to the informed consumer. Such claims are allowed for products having been shown in vivo not to depress plaque pH below 5.7, neither during nor for 30 minutes after the consumption. However, various chewing gum manufacturers have recently begun to make distinct health promotion claims, suggesting, e.g., reparative action or substitution for mechanical hygiene. The aim of this critical review--covering the effects of the physical properties of chewing gum and those of different ingredients both of conventional and of functional chewing gum--is to provide a set of guidelines for the interpretation of such claims and to assist oral health care professionals in counseling patients.

Plastome Sequences of Lygodium japonicum and Marsilea crenata Reveal the Genome Organization Transformation from Basal Ferns to Core Leptosporangiates

PubMed Central

Gao, Lei; Wang, Bo; Wang, Zhi-Wei; Zhou, Yuan; Su, Ying-Juan; Wang, Ting

2013-01-01

Previous studies have shown that core leptosporangiates, the most species-rich group of extant ferns (monilophytes), have a distinct plastid genome (plastome) organization pattern from basal fern lineages. However, the details of genome structure transformation from ancestral ferns to core leptosporangiates remain unclear because of limited plastome data available. Here, we have determined the complete chloroplast genome sequences of Lygodium japonicum (Lygodiaceae), a member of schizaeoid ferns (Schizaeales), and Marsilea crenata (Marsileaceae), a representative of heterosporous ferns (Salviniales). The two species represent the sister and the basal lineages of core leptosporangiates, respectively, for which the plastome sequences are currently unavailable. Comparative genomic analysis of all sequenced fern plastomes reveals that the gene order of L. japonicum plastome occupies an intermediate position between that of basal ferns and core leptosporangiates. The two exons of the fern ndhB gene have a unique pattern of intragenic copy number variances. Specifically, the substitution rate heterogeneity between the two exons is congruent with their copy number changes, confirming the constraint role that inverted repeats may play on the substitution rate of chloroplast gene sequences. PMID:23821521

[Extruded rice flour as a gluten substitute in the poduction of rice bread].

PubMed

Clerici, Maria Teresa Pedrosa Silva; El-Dash, Ahmed A

2006-09-01

Research regarding the production of gluten-free bread (GFB) is very important nutritionally, technically and economically speaking, both to celiac patients and to developing countries who import wheat. The main technological problem in the production of GFB is obtaining a gluten substitute that is both inexpensive and capable of retaining gas during bread fermentation and baking. The use of gelatinized starch as an alternative for gluten seems promising. In this project, rice bread was made using pregelatinized extruded rice flour as a gluten substitute. Pre-gelatinized rice flours (PRF) were manufactured in a single screw Brabender extruder, varying extrusion temperature (108-192 degrees C) and the moisture of the raw material (19.2 - 24.8%), and were used in a proportion of 10 g for every 100 g of raw rice flour, in the production of gluten-free bread. Results showed that rice flour extruded at a high temperature (180 degrees) and low moisture content (20%), rendered bread with the best technological characteristics, presenting crust and crumb color similar to those of conventional wheat bread, although with volume and texture not as satisfactory in the same comparison.

Femtosecond transient photoluminescence of the substituted poly(diphenylacetulene)s.

NASA Astrophysics Data System (ADS)

Piskun, N. V.; Wang, D. K.; Lim, H.; Epstein, A. J.; Vanwoerkom, L. D.; Gustafson, T. L.

2000-03-01

We present the results of a femtosecond transient photoluminescence (PL) study of solutions of two derivatives of substituted poly(diphenylacetylene) using an up-conversion technique. n-Butyl (nBu) and p-carbazole (Cz) substituted poly(diphenylacetylene), PDPA-nBu and PDPA-Cz respectively, have band gaps determined by maxima in the slope of absorption vs. energy of 2.75 eV and 2.63 eV. The steady state emission peaks are at 2.4 eV for PDPA-nBu and at 2.3 eV for PDPA-Cz respectively. The PL peak for PDPA-Cz is red shifted in comparison to the PL peak for PDPA-nBu. Roles of phenyl groups, electron donating effect of the carbazole side units and planarity of the backbone are discussed. Exciting at 3.1 eV, the fs PL shows a faster decay for PDPA-Cz than that for PDPA-nBu, in accord with the decrease of PL quantum efficiency of PDPA-Cz. The 200 fs - 80 ps PL(t) agrees with ~1 ns lifetime. The PDPA-Cz has larger red shift in the 0.2-20 ps time frame. The origin of that shift will be discussed. This work is supported in part by ONR.

Selenite sorption by carbonate substituted apatite

DOE PAGES

Moore, Robert C.; Rigali, Mark J.; Brady, Patrick

2016-08-31

The sorption of selenite, SeO 3 2–, by carbonate substituted hydroxylapatite was investigated using batch kinetic and equilibrium experiments. The carbonate substituted hydroxylapatite was prepared by a precipitation method and characterized by SEM, XRD, FT-IR, TGA, BET and solubility measurements. The material is poorly crystalline, contains approximately 9.4% carbonate by weight and has a surface area of 210.2 m 2/g. Uptake of selenite by the carbonated hydroxylapatite was approximately an order of magnitude higher than the uptake by uncarbonated hydroxylapatite reported in the literature. Distribution coefficients, K d, determined for the carbonated apatite in this work ranged from approximately 4200more » to over 14,000 L/kg. A comparison of the results from kinetic experiments performed in this work and literature kinetic data indicates the carbonated apatite synthesized in this study sorbed selenite 23 times faster than uncarbonated hydroxylapatite based on values normalized to the surface area of each material. Furthermore, the results indicate carbonated apatite is a potential candidate for use as a sorbent for pump-and-treat technologies, soil amendments or for use in permeable reactive barriers for the remediation of selenium contaminated sediments and groundwaters.« less

Elastomeric enriched biodegradable polyurethane sponges for critical bone defects: a successful case study reducing donor site morbidity.

PubMed

Lavrador, Catarina; Mascarenhas, Ramiro; Coelho, Paulo; Brites, Cláudia; Pereira, Alfredo; Gogolewski, Sylwester

2016-03-01

Bone substitutes have been a critical issue as the natural source can seldom provide enough bone to support full healing. No bone substitute complies with all necessary functions and characteristics that an autograft does. Polyurethane sponges have been used as a surgical alternative to cancellous bone grafts for critical bone defect donor sites. Critical bone defects were created on the tibial tuberosity and iliac crest using an ovine model. In group I (control-untreated), no bone regeneration was observed in any animal. In group II (defects left empty but covered with a microporous polymeric membrane), the new bone bridged the top ends in all animals. In groups III and IV, bone defects were implanted with polyurethane scaffolds modified with biologically active compounds, and bone regeneration was more efficient than in group II. In groups III and IV there were higher values of bone regeneration specific parameters used for evaluation (P < 0.05) although the comparison between these groups was not possible. The results obtained in this study suggest that biodegradable polyurethane substitutes modified with biologically active substances may offer an alternative to bone graft, reducing donor site morbidity associated with autogenous cancellous bone harvesting.

Cost comparison and economic implications of commonly used originator and generic chemotherapy drugs in India.

PubMed

Lopes, G de L

2013-09-01

Cancer treatments have improved outcomes but access to medications is an issue around the world and especially so in low- and middle-income countries, such as India. Generic substitution may lead to significant cost savings. The author aimed to compare the cost and estimate potential cost savings per cycle, per patient, and for the country as a whole with generic substitution of frequently used chemotherapy drugs in the treatment of common cancers in India. Generic paclitaxel (Taxol), docetaxel (Taxotere), gemcitabine, oxaliplatin and irinotecan cost from 8.9% to 36% of their equivalent branded originator drug, resulting in cost savings of ~ Indian Rupees (INR) 11,000 to >INR 90,000 (USD 200-1600, Euro 160-1300) per cycle; and ~INR 50,000 to >INR 240,000 (USD 900-4300, Euro 700-3400) per patient. Overall, potential yearly savings for health systems in India were nearly INR 47 billion (~USD 843 million, Euro 670 million). In conclusion, generic substitution for frequently used chemotherapy drugs in the treatment of common cancers has an enormous potential to generate significant cost savings and increase access to cancer treatments in India and other low- and middle-income countries.

Cholecystokinin octapeptide analogues stable to brain proteolysis.

PubMed

Knight, M; Barone, P; Tamminga, C A; Steardo, L; Chase, T N

1985-01-01

Based on recent findings identifying the initial degradative cleavage of CCK-8 at the Met3-Gly4 bond by a metalloendopeptidase, two analogues of CCK-8 with D-Ala and D-Trp substitutions at the Gly4 position were synthesized as stable analogues. Their stability to proteolysis by brain membranes and their binding potency at central CCK receptors were quantified. Both peptides are stable to degradation by peptidases in cortical synaptic membrane preparations. The analogues are nearly equipotent to CCK-8 in their affinities for inhibition of 125I-CCK-33 binding to guinea pig cortical membranes. L-Ala and L-Trp substituted peptides were synthesized for comparison. Both these peptides are degraded by synaptic membranes and the L-Trp substituted peptide possesses a greatly reduced affinity for central CCK receptors. Therefore, the structure of CCK due to the D conformation of Gly is more capable of interacting with brain CCK receptors. Further conformational analysis will establish whether the stabilized structure is a beta-bend or a beta-turn. Since these peptides are highly potent and stable to brain proteolysis they may be useful as stable CCK analogues for in vivo application.

Novel mutations and mutation combinations of ryanodine receptor in a chlorantraniliprole resistant population of Plutella xylostella (L.)

PubMed Central

Guo, Lei; Liang, Pei; Zhou, Xuguo; Gao, Xiwu

2014-01-01

A previous study documented a glycine to glutamic acid mutation (G4946E) in ryanodine receptor (RyR) was highly correlated to diamide insecticide resistance in field populations of Plutella xylostella (Lepidoptera: Plutellidae). In this study, a field population collected in Yunnan province, China, exhibited a 2128-fold resistance to chlorantraniliprole. Sequence comparison between resistant and susceptible P. xylostella revealed three novel mutations including a glutamic acid to valine substitution (E1338D), a glutamine to leucine substitution (Q4594L) and an isoleucine to methionine substitution (I4790M) in highly conserved regions of RyR. Frequency analysis of all four mutations in this field population showed that the three new mutations showed a high frequency of 100%, while the G4946E had a frequency of 20%. Furthermore, the florescent ligand binding assay revealed that the RyR containing multiple mutations displayed a significantly lower affinity to the chlorantraniliprole. The combined results suggested that the co-existence of different combinations of the four mutations was involved in the chlorantraniliprole resistance. An allele-specific PCR based method was developed for the diagnosis of the four mutations in the field populations of P. xylostella. PMID:25377064

Effects of lactoferrin derived peptides on simulants of biological warfare agents.

PubMed

Sijbrandij, Tjitske; Ligtenberg, Antoon J; Nazmi, Kamran; Veerman, Enno C I; Bolscher, Jan G M; Bikker, Floris J

2017-01-01

Lactoferrin (LF) is an important immune protein in neutrophils and secretory fluids of mammals. Bovine LF (bLF) harbours two antimicrobial stretches, lactoferricin and lactoferampin, situated in close proximity in the N1 domain. To mimic these antimicrobial domain parts a chimeric peptide (LFchimera) has been constructed comprising parts of both stretches (LFcin17-30 and LFampin265-284). To investigate the potency of this construct to combat a set of Gram positive and Gram negative bacteria which are regarded as simulants for biological warfare agents, the effect on bacterial killing, membrane permeability and membrane polarity were determined in comparison to the constituent peptides and the native bLF. Furthermore we aimed to increase the antimicrobial potency of the bLF derived peptides by cationic amino acid substitutions. Overall, the bactericidal activity of the peptides could be related to membrane disturbing effects, i.e. membrane permeabilization and depolarization. Those effects were most prominent for the LFchimera. Arginine residues were found to be crucial for displaying antimicrobial activity, as lysine to arginine substitutions resulted in an increased antimicrobial activity, affecting mostly LFampin265-284 whereas arginine to lysine substitutions resulted in a decreased bactericidal activity, predominantly in case of LFcin17-30.

Recyclable catalysts methods of making and using the same

DOEpatents

Dioumaev, Vladimir K.; Bullock, R. Morris

2006-02-28

Organometallic complexes are provided, which include a catalyst containing a transition metal, a ligand and a component having the formula GAr.sup.F. Ar.sup.F is an aromatic ring system selected from phenyl, naphthalenyl, anthracenyl, fluorenyl, or indenyl. The aromatic ring system has at least a substituent selected from fluorine, hydrogen, hydrocarbyl or fluorinated hydrocarbyl, G is substituted or unsubstituted (CH.sub.2).sub.n or (CF.sub.2).sub.n, wherein n is from 1 to 30, wherein further one or more CH.sub.2 or CF.sub.2 groups are optionally replaced by NR, PR, SiR.sub.2, BR, O or S, or R is hydrocarbyl or substituted hydrocarbyl, GAr.sup.F being covalently bonded to either said transition metal or said ligand of said catalyst, thereby rendering said cationic organometallic complex liquid. The catalyst of the organometallic complex can be [CpM(CO).sub.2(NHC)L.sub.k].sup.+A.sup.-, wherein M is an atom of molybdenum or tungsten, Cp is substituted or unsubstituted cyclopentadienyl radical represented by the formula [C.sub.5Q.sup.1Q.sup.2Q.sup.3Q.sup.4Q.sup.5], wherein Q.sup.1 to Q.sup.5 are independently selected from the group consisting of H radical, GAr.sup.F C.sub.1-20 hydrocarbyl radical, substituted hydrocarbyl radical, substituted hydrocarbyl radical substituted by GAr.sup.F, halogen radical, halogen-substituted hydrocarbyl radical, --OR, --C(O)R', --CO.sub.2R', --SiR'.sub.3 and --NR'R'', wherein R' and R'' are independently selected from the group consisting of H radical, C.sub.1-20 hydrocarbyl radical, halogen radical, and halogen-substituted hydrocarbyl radical, wherein said Q.sup.1 to Q.sup.5 radicals are optionally linked to each other to form a stable bridging group, NHC is any N-heterocyclic carbene ligand, L is either any neutral electron donor ligand, wherein k is a number from 0 to 1 or L is an anionic ligand wherein k is 2, and A.sup.- is an anion. Processes using the organometallic complexes as catalysts in catalytic reactions, such as for example, the hydrosilylation of aldehydes, ketones and esters are also provided.

Consumer acceptance of dishes in which beef has been partially substituted with mushrooms and sodium has been reduced.

PubMed

Guinard, Jean-Xavier; Myrdal Miller, Amy; Mills, Kelly; Wong, Thomas; Lee, Soh Min; Sirimuangmoon, Chirat; Schaefer, Sarah E; Drescher, Greg

2016-10-01

We tested the hypothesis that because of their flavor-enhancing properties, mushrooms could be used as a healthy substitute for meat and a mitigating agent for sodium (salt) reduction without reduction in sensory appeal among consumers. In a fully-randomized design for each product, 147 consumers evaluated blind two carne asada and six taco blend recipes in which beef had been partially substituted with mushrooms and/or salt had been reduced by 25%, for overall liking, liking of appearance, flavor, texture and mouth feel on the 9-point hedonic scale, and adequacy of level of saltiness, spiciness and moistness on 5-point just-about-right (JAR) scales. Overall consumer acceptance of the carne asada, and liking for its appearance, flavor and texture/mouth feel decreased significantly when half the steak was substituted with mushrooms. The taco blend recipes with full sodium were also liked more overall than those with 25% less sodium. But there was no significant difference in overall liking among the three full-salt recipes, nor among the three reduced-salt recipes, indicating that across the consumer population we tested, acceptance of the mushroom-containing recipes was on par with that of the 100% beef recipe. The preference mapping analysis of the overall liking ratings of the taco blends uncovered four preference segments, two of which, representing a majority of the consumers, gave higher acceptance scores to the mushroom-substituted recipes. Furthermore, the largest preference segment liked the full- and reduced-sodium recipes equally, and another liked the reduced-sodium recipes significantly more. This research demonstrates that through their flavor enhancing properties, mushrooms can be used successfully to substitute for beef and even possibly mitigate sodium reduction without significant change in acceptance for a majority of consumers. Copyright © 2016 Elsevier Ltd. All rights reserved.

OPHIDIAN L-AMINO ACID OXIDASE. THE NATURE OF THE ENZYME-SUBSTRATE COMPLEXES.

PubMed

ZELLER, E A; RAMACHANDER, G; FLEISHER, G A; ISHIMARU, T; ZELLER, V

1965-04-01

1. To investigate the kinetics of ophidian l-amino acid oxidase, V and K(m) were determined for phenylalanines that were substituted in every ring position with groups of various size and reactivity, and for a few ring-substituted tryptophans and histidines. The venom of one representative from each of three major classes of poisonous snakes, Naja melanoleuca, Vipera russelli and Crotalus adamanteus, served as a source of the ophidian l-amino acid oxidase. Both crude and crystalline enzyme from the venom of C. adamanteus were tested. 2. The introduction of a benzene ring into glycine and alanine caused some increase of V and a very marked depression of K(m). 3. With the exception of fluorine, residues in the ortho position of phenylalanine led to a decrease of V. The rates induced by various substitutions follow the pattern: meta >/= para >/= ortho. Within the halogen series, the effects become more pronounced with increasing atomic number. 4. Ring substitution in heterocyclic amino acids also affected the V values markedly. For methyl-substituted tryptophans the pattern was: 5-methyl >/= 6-methyl >/= 4-methyl. In a few instances ring substitution accounts for a considerable elevation of V, as shown for beta-quinol-4-ylalanine and its 6-methoxy derivative. 5. The kinetic constants appear to be unaffected by relatively high concentrations of the corresponding d-amino acids. 6. A general principle that permits a uniform interpretation of a vast body of information is suggested. It is based on the assumption that most substrates form not only eutopic but also dystopic complexes with the enzyme. The latter, in contrast with the former, do not permit the formation of reaction products. K values for eutopic and dystopic complexes are computed. Similar concepts have been presented to elucidate the action of alpha-chymotrypsin (Hein & Niemann, 1962) and of monoamine oxidase.

Coevolution between Nuclear-Encoded DNA Replication, Recombination, and Repair Genes and Plastid Genome Complexity.

PubMed

Zhang, Jin; Ruhlman, Tracey A; Sabir, Jamal S M; Blazier, John Chris; Weng, Mao-Lun; Park, Seongjun; Jansen, Robert K

2016-02-17

Disruption of DNA replication, recombination, and repair (DNA-RRR) systems has been hypothesized to cause highly elevated nucleotide substitution rates and genome rearrangements in the plastids of angiosperms, but this theory remains untested. To investigate nuclear-plastid genome (plastome) coevolution in Geraniaceae, four different measures of plastome complexity (rearrangements, repeats, nucleotide insertions/deletions, and substitution rates) were evaluated along with substitution rates of 12 nuclear-encoded, plastid-targeted DNA-RRR genes from 27 Geraniales species. Significant correlations were detected for nonsynonymous (dN) but not synonymous (dS) substitution rates for three DNA-RRR genes (uvrB/C, why1, and gyrA) supporting a role for these genes in accelerated plastid genome evolution in Geraniaceae. Furthermore, correlation between dN of uvrB/C and plastome complexity suggests the presence of nucleotide excision repair system in plastids. Significant correlations were also detected between plastome complexity and 13 of the 90 nuclear-encoded organelle-targeted genes investigated. Comparisons revealed significant acceleration of dN in plastid-targeted genes of Geraniales relative to Brassicales suggesting this correlation may be an artifact of elevated rates in this gene set in Geraniaceae. Correlation between dN of plastid-targeted DNA-RRR genes and plastome complexity supports the hypothesis that the aberrant patterns in angiosperm plastome evolution could be caused by dysfunction in DNA-RRR systems. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Comparison between three different saliva substitutes in patients with hyposalivation.

PubMed

Skrinjar, Ivana; Vucicevic Boras, Vanja; Bakale, Iva; Andabak Rogulj, Ana; Brailo, Vlaho; Vidovic Juras, Danica; Alajbeg, Ivan; Vrdoljak, Danko Velimir

2015-04-01

The aim of the present study was to compare the efficiency of oral spray based on thermal spring water (Buccotherm®) versus commercial saliva substitute (Xeros®) and marshmallow root on the quality of life in patients with hyposalivation. A total of 60 patients with unstimulated salivary flow rate <0.2 ml/min were randomized into three groups. In the first group, 30 patients were using Buccotherm®; in the second group, 15 patients were using Xeros®; and in the third group, 15 patients were using marshmallow root. Therapy lasted for 2 weeks; everyday, patients used one of the products four times a day. Quality of life was measured by the Croatian version of Oral Health Impact Profile 14 questionnaire, and visual analog scale was used to determine the intensity of dry mouth before and after therapy. Statistical analysis was performed by Wilcoxon signed-rank test and Kruskal-Wallis test. Standardized effect size was calculated for OHIP following treatment. Buccotherm® has shown the biggest effect on quality of life in patients with hyposalivation. Intensity of dry mouth was lower after the applied therapy whatever substitute patients used. We recommend the use of all three saliva substitutes for decreasing the intensity of dry mouth symptoms as well as improvement in the quality of life. Although all tested agents showed beneficial effect in alleviating hyposalivation symptoms, it seems that Buccotherm® was superior to Xeros® and marshmallow root.

Structural evolution of luciferase activity in Zophobas mealworm AMP/CoA-ligase (protoluciferase) through site-directed mutagenesis of the luciferin binding site.

PubMed

Prado, R A; Barbosa, J A; Ohmiya, Y; Viviani, V R

2011-07-01

The structural origin and evolution of bioluminescent activity of beetle luciferases from AMP/CoA ligases remains a mystery. Previously we cloned the luciferase-like enzyme from Zophobas morio mealworm, a reasonable protoluciferase model that could shine light on this mystery. Kinetic characterization and studies with D- and L-luciferin and their adenylates showed that stereoselectivity constitutes a critical feature for the origin of luciferase activity in AMP/CoA ligases. Comparison of the primary structures and modeling studies of this protoluciferase and the three main families of beetle luciferases showed that the carboxylic acid substrate binding site of this enzyme is smaller and more hydrophobic than the luciferin binding site of beetle luciferases, showing several substitutions of otherwise conserved residues. Thus, here we performed a site-directed mutagenesis survey of the carboxylic binding site motifs of the protoluciferase by replacing their residues by the respective conserved ones found in beetle luciferases in order to identify the structural determinants of luciferase/oxygenase activity. Although most of the substitutions had negative impact on the luminescence activity of the protoluciferase, only the substitution I327T improved the luminescence activity, resulting in a broad and 15 nm blue-shifted luminescence spectrum. Such substitution indicates the importance of the loop motif 322YGMSEI327 (341YGLTETT347 in Photinus pyralis luciferase) for luciferase activity, and indicates a possible route for the evolution of bioluminescence function of beetle luciferases.

Predicting hydration Gibbs energies of alkyl-aromatics using molecular simulation: a comparison of current force fields and the development of a new parameter set for accurate solvation data.

PubMed

Garrido, Nuno M; Jorge, Miguel; Queimada, António J; Gomes, José R B; Economou, Ioannis G; Macedo, Eugénia A

2011-10-14

The Gibbs energy of hydration is an important quantity to understand the molecular behavior in aqueous systems at constant temperature and pressure. In this work we review the performance of some popular force fields, namely TraPPE, OPLS-AA and Gromos, in reproducing the experimental Gibbs energies of hydration of several alkyl-aromatic compounds--benzene, mono-, di- and tri-substituted alkylbenzenes--using molecular simulation techniques. In the second part of the paper, we report a new model that is able to improve such hydration energy predictions, based on Lennard Jones parameters from the recent TraPPE-EH force field and atomic partial charges obtained from natural population analysis of density functional theory calculations. We apply a scaling factor determined by fitting the experimental hydration energy of only two solutes, and then present a simple rule to generate atomic partial charges for different substituted alkyl-aromatics. This rule has the added advantages of eliminating the unnecessary assumption of fixed charge on every substituted carbon atom and providing a simple guideline for extrapolating the charge assignment to any multi-substituted alkyl-aromatic molecule. The point charges derived here yield excellent predictions of experimental Gibbs energies of hydration, with an overall absolute average deviation of less than 0.6 kJ mol(-1). This new parameter set can also give good predictive performance for other thermodynamic properties and liquid structural information.

Metal Binding by the D,DX35E Motif of Human Immunodeficiency Virus Type 1 Integrase: Selective Rescue of Cys Substitutions by Mn2+ In Vitro

PubMed Central

Gao, Kui; Wong, Steven; Bushman, Frederic

2004-01-01

The D,DX35E motif characteristic of retroviral integrase enzymes (INs) is expected to bind the required metal cofactors (Mg2+ or Mn2+), but direct evidence for a catalytic role has been lacking. Here we used a metal rescue strategy to investigate metal binding. We established conditions for analysis of an activity of IN, disintegration, in both Mg2+ and Mn2+, and tested IN mutants with cysteine substitutions in each acidic residue of the D,DX35E motif. Mn2+ but not Mg2+ can bind tightly to Cys, so if metal binding at the acidic residues is mechanistically important, it is expected that the Cys-substituted enzymes would be active in the presence of Mn2+ only. Of the three acidic residues, a strong metal rescue effect was obtained for D116C, a weaker rescue was seen for D64C, and no rescue was seen with E152C. Modest rescue could also be detected for D116C in normal integration in vitro. Comparison to Ser and Ala substitutions at D116 established that the rescue was selective for Cys. Further studies of the response to pH suggest that the metal cofactor may stabilize the deprotonated nucleophile active in catalysis, and studies of the response to NaCl titrations disclose an additional role for the metal cofactor in stabilizing the IN-DNA complex. PMID:15194746

Quality Protein Maize for Africa: Closing the Protein Inadequacy Gap in Vulnerable Populations12

PubMed Central

Nuss, Emily T.; Tanumihardjo, Sherry A.

2011-01-01

Africa shares a unique relationship with maize (Zea mays). After its introduction from New World explorers, maize was quickly adopted as the cornerstone of local cuisine, especially in sub-Saharan countries. Although maize provides macro- and micronutrients required for humans, it lacks adequate amounts of the essential amino acids lysine and tryptophan. For those consuming >50% of their daily energy from maize, pandemic protein malnutrition may exist. Severe protein and energy malnutrition increases susceptibility to life-threatening diseases such as tuberculosis and gastroenteritis. A nutritionally superior maize cultivar named quality protein maize (QPM) represents nearly one-half century of research dedicated to malnutrition eradication. Compared with traditional maize types, QPM has twice the amount of lysine and tryptophan, as well as protein bioavailability that rivals milk casein. Animal and human studies suggest that substituting QPM for common maize results in improved health. However, QPM’s practical contribution to maize-subsisting populations remains unresolved. Herein, total protein and essential amino acid requirements recommended by the WHO and the Institute of Medicine were applied to estimate QPM target intake levels for young children and adults, and these were compared with mean daily maize intakes by African country. The comparisons revealed that ∼100 g QPM is required for children to maintain adequacy of lysine, the most limiting amino acid, and nearly 500 g is required for adults. This represents a 40% reduction in maize intake relative to common maize to meet protein requirements. The importance of maize in Africa underlines the potential for QPM to assist in closing the protein inadequacy gap. PMID:22332054

Treatment of Peripheral T-Cell Lymphoma: Many Shades of Gray.

PubMed

Lunning, Matthew A

2015-08-01

Previously obscured within other designations of aggressive lymphomas, peripheral T-cell lymphoma (PTCL) now represents 23 different subtypes of non-Hodgkin lymphoma (NHL). Despite the many subtypes now recognized, PTCL represents only approximately 10% of all NHL cases diagnosed. Positron emission tomography/computed tomography has become essential to accurate staging and response-evaluation for PTCL. In comparison to aggressive B-cell NHL, patients with PTCL will more often be refractory to initial therapy, and chemosensitive patients will have shorter disease-free periods. Anthracycline-based regimens, often with the inclusion of etoposide, are commonly used during induction therapy. Consolidation with high-dose therapy and autologous stem cell transplantation (ASCT) in first chemosensitive remission appears to provide the best outcome in common nodal PTCL subtypes. The commonly defined nodal subtypes are PTCL not otherwise specified, angioimmunoblastic T-cell lymphoma, and anaplastic lymphoma kinase (ALK)-positive or ALK-negative anaplastic large-cell lymphoma (ALCL). Four agents have been approved by the US Food and Drug Administration for use in the relapsed/refractory (rel/ref) setting, including belinostat (2014), romidepsin (2011), brentuximab vedotin (2011), and pralatrexate (2009). Brentuximab vedotin was approved only for the ALCL subtype. These agents continue to be studied as combinations in the rel/ref setting and as additions or substitutions for other agents in upfront multiagent chemotherapy regimens. Patients who have responded to treatment in the rel/ref setting and are considered transplant-eligible should be considered for allogeneic stem cell transplantation, especially those with previous ASCT. Upfront allogeneic stem cell transplantation remains a research question in the majority of PTCL subtypes, but data are emerging.

Differential Effects of the G118R, H51Y, and E138K Resistance Substitutions in Different Subtypes of HIV Integrase

PubMed Central

Quashie, Peter K.; Oliviera, Maureen; Veres, Tamar; Osman, Nathan; Han, Ying-Shan; Hassounah, Said; Lie, Yolanda; Huang, Wei; Mesplède, Thibault

2014-01-01

ABSTRACT Dolutegravir (DTG) is the latest antiretroviral (ARV) approved for the treatment of human immunodeficiency virus (HIV) infection. The G118R substitution, previously identified with MK-2048 and raltegravir, may represent the initial substitution in a dolutegravir resistance pathway. We have found that subtype C integrase proteins have a low enzymatic cost associated with the G118R substitution, mostly at the strand transfer step of integration, compared to either subtype B or recombinant CRF02_AG proteins. Subtype B and circulating recombinant form AG (CRF02_AG) clonal viruses encoding G118R-bearing integrases were severely restricted in their viral replication capacity, and G118R/E138K-bearing viruses had various levels of resistance to dolutegravir, raltegravir, and elvitegravir. In cell-free experiments, the impacts of the H51Y and E138K substitutions on resistance and enzyme efficiency, when present with G118R, were highly dependent on viral subtype. Sequence alignment and homology modeling showed that the subtype-specific effects of these mutations were likely due to differential amino acid residue networks in the different integrase proteins, caused by polymorphic residues, which significantly affect native protein activity, structure, or function and are important for drug-mediated inhibition of enzyme activity. This preemptive study will aid in the interpretation of resistance patterns in dolutegravir-treated patients. IMPORTANCE Recognized drug resistance mutations have never been reported for naive patients treated with dolutegravir. Additionally, in integrase inhibitor-experienced patients, only R263K and other previously known integrase resistance substitutions have been reported. Here we suggest that alternate resistance pathways may develop in non-B HIV-1 subtypes and explain how “minor” polymorphisms and substitutions in HIV integrase that are associated with these subtypes can influence resistance against dolutegravir. This work also highlights the importance of phenotyping versus genotyping when a strong inhibitor such as dolutegravir is being used. By characterizing the G118R substitution, this work also preemptively defines parameters for a potentially important pathway in some non-B HIV subtype viruses treated with dolutegravir and will aid in the inhibition of such a virus, if detected. The general inability of strand transfer-related substitutions to diminish 3′ processing indicates the importance of the 3′ processing step and highlights a therapeutic angle that needs to be better exploited. PMID:25552724

Differential effects of the G118R, H51Y, and E138K resistance substitutions in different subtypes of HIV integrase.

PubMed

Quashie, Peter K; Oliviera, Maureen; Veres, Tamar; Osman, Nathan; Han, Ying-Shan; Hassounah, Said; Lie, Yolanda; Huang, Wei; Mesplède, Thibault; Wainberg, Mark A

2015-03-01

Dolutegravir (DTG) is the latest antiretroviral (ARV) approved for the treatment of human immunodeficiency virus (HIV) infection. The G118R substitution, previously identified with MK-2048 and raltegravir, may represent the initial substitution in a dolutegravir resistance pathway. We have found that subtype C integrase proteins have a low enzymatic cost associated with the G118R substitution, mostly at the strand transfer step of integration, compared to either subtype B or recombinant CRF02_AG proteins. Subtype B and circulating recombinant form AG (CRF02_AG) clonal viruses encoding G118R-bearing integrases were severely restricted in their viral replication capacity, and G118R/E138K-bearing viruses had various levels of resistance to dolutegravir, raltegravir, and elvitegravir. In cell-free experiments, the impacts of the H51Y and E138K substitutions on resistance and enzyme efficiency, when present with G118R, were highly dependent on viral subtype. Sequence alignment and homology modeling showed that the subtype-specific effects of these mutations were likely due to differential amino acid residue networks in the different integrase proteins, caused by polymorphic residues, which significantly affect native protein activity, structure, or function and are important for drug-mediated inhibition of enzyme activity. This preemptive study will aid in the interpretation of resistance patterns in dolutegravir-treated patients. Recognized drug resistance mutations have never been reported for naive patients treated with dolutegravir. Additionally, in integrase inhibitor-experienced patients, only R263K and other previously known integrase resistance substitutions have been reported. Here we suggest that alternate resistance pathways may develop in non-B HIV-1 subtypes and explain how "minor" polymorphisms and substitutions in HIV integrase that are associated with these subtypes can influence resistance against dolutegravir. This work also highlights the importance of phenotyping versus genotyping when a strong inhibitor such as dolutegravir is being used. By characterizing the G118R substitution, this work also preemptively defines parameters for a potentially important pathway in some non-B HIV subtype viruses treated with dolutegravir and will aid in the inhibition of such a virus, if detected. The general inability of strand transfer-related substitutions to diminish 3' processing indicates the importance of the 3' processing step and highlights a therapeutic angle that needs to be better exploited. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Dihydroberkleasmin A: a new eremophilane sesquiterpenoid from the fermentation broth of the plant endophytic fungus Pestalotiopsis photiniae.

PubMed

Yang, Xiao-Long; Zhang, Su; Zhu, Hua-Jie; Luo, Du-Qiang

2011-02-23

Dihydroberkleasmin A (1), a new ester-substituted sesquiterpenoid related to the eremophilane class, together with the known compound berkleasmin C (2), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis photiniae. The structure of dihydroberkleasmin A (1) was elucidated by extensive spectroscopic analysis. The stereochemistry was assigned by comparison of the NMR spectroscopic data with those of berkleasmin A.

Volatiles from the xylarialean fungus Hypoxylon invadens.

PubMed

Dickschat, Jeroen S; Wang, Tao; Stadler, Marc

2018-01-01

The volatiles emitted by agar plate cultures of the xylarialean fungus Hypoxylon invadens were investigated by use of a closed loop stripping apparatus in combination with GC-MS. Several aromatic compounds were found that could only be identified by comparison to all possible constitutional isomers with different ring substitution patterns. For the set of identified compounds a plausible biosynthetic scheme was suggested that gives further support for the assigned structures.

Environmental Enrichment of Laboratory Rodents: The Answer Depends on the Question

DTIC Science & Technology

2011-01-01

that offer enhanced sensory , motor, and cognitive stimulation of brain neuronal systems in comparison with standard caging13 and, alternatively, as...benefit the animal in a signifi- cant way in terms of stimulation of positive species-typical behaviors and/or prevention of abnormal or undesirable...naturalistic nesting materials, as compared with less natural substitutes, al- lows laboratory mice to construct complex dome-shaped, multi - layered nests

Comparison of serum and plasma measurements of Müllerian inhibiting substance.

PubMed

Merhi, Zaher O; Messerlian, Geralyn M; Minkoff, Howard; Eklund, Elizabeth E; Macura, Jerzy; Feldman, Joseph; Rodriguez, Carlos; Seifer, David B

2008-06-01

The authors sought to determine whether measurement of plasma Müllerian inhibiting substance (MIS) is a suitable substitute for measurement of serum MIS. Eighteen samples of serum and plasma were examined that were drawn simultaneously. Levels of MIS were measured with an ELISA kit, and plasma levels were studied in parallel to serum samples. A 98.5% correlation was found between serum and plasma MIS values.

Army Aviation Maintenance Career Management Field 67 Study

DTIC Science & Technology

1980-10-08

Occupational Specialties (MOS) Specifications 121 Current Inventory Impacts 121 MOS Substitutability 122 Elimination of MOS 67W 123 *ilization of Females in CMF...Operating Strength 67 3-6 Impact of New MACRIT on TOE 78 3-7 67 Series Authorizations Without Technical Supervision 81 3-8 68 Series Authorizations...restructuring and duty realignment necessitated the development of new MOS duty descriptions. (6) CURRENT INVENTORY IMPACT . A comparison of current and

A Comparison of the Ecological Effects of Herbicide and Prescribed Fire in a Mature Longleaf Pine Forest: Response of Juvenile and Overstory Pine

Treesearch

Jennifer L. Gagnon; Steven B. Jack

2004-01-01

Prescribed fire may be removed as a forest management tool by regulatory agencies concerned about air quality issues. Herbicides have been proposed as substitutes for prescribed fires in southern pine forests, but we are aware of no studies that examine the effects of herbicide application in mature, fire maintained longleaf pine (Pinus palustris...

Influence of Si substitution on the reactivity of α-tricalcium phosphate.

PubMed

Motisuke, Mariana; Mestres, Gemma; Renó, Caroline O; Carrodeguas, Raúl G; Zavaglia, Cecília A C; Ginebra, Maria-Pau

2017-06-01

Silicon substituted calcium phosphates have been widely studied over the last ten years due to their enhanced osteogenic properties. Notwithstanding, the role of silicon on α-TCP reactivity is not clear yet. Therefore, the aim of this work was to evaluate the reactivity and the properties of Si-α-TCP in comparison to α-TCP. Precursor powders have similar properties regarding purity, particle size distribution and specific surface area, which allowed a better comparison of the Si effects on their reactivity and cements properties. Both Si-α-TCP and α-TCP hydrolyzed to a calcium-deficient hydroxyapatite when mixed with water but their conversion rates were different. Si-α-TCP exhibited a slower setting rate than α-TCP, i.e. k SSA for Si-TCP (0.021g·m -2 ·h -1 ) was almost four times lower than for α-TCP (0.072g·m -2 ·h -1 ). On the other hand, the compressive strength of the CPC resulting from fully reacted Si-α-TCP was significantly higher (12.80±0.38MPa) than that of α-TCP (11.44±0.54MPa), due to the smaller size of the entangled precipitated apatite crystals. Copyright © 2017. Published by Elsevier B.V.

Fracture behaviour of WC-Co hardmetals with WC partially substituted by titanium carbide

NASA Astrophysics Data System (ADS)

Szutkowska, M.; Boniecki, M.; Cygan, S.; Kalinka, A.; Grilli, M. L.; Balos, S.

2018-03-01

The addition of various amounts of TiC0.9 phase in the range from 5wt.% to 20wt.% substituting WC phase was applied in WC-Co hardmetals with 9.5 wt.% bonding cobalt phase. The hardmetals were consolidated using Hot Isostatic Pressing (HIP) method at temperature of 1573K and pressure of 1500 atm. The plain strain fracture toughness has been determined from 3PB test on a precracking single edge notched beam (SENB) specimen. The indentation fracture toughness with Vickers cracks for comparison was also measured, which changed from 12 to 9.0 MPa·m1/2. The amount of the TiC0.9 phase affected the mechanical and physical properties: Vickers hardness from 12.5 to 14.0 GPa, Young’s modulus from 550 to 460 GPa, density from 13.1 to 9.6 g/cm3, friction coefficient from 0.24 to 0.45, fracture toughness from 16.8 to 11.0 MPa·m1/2. Scanning electron microscopy (SEM), X-ray and electron diffraction phase analysis were used to examine the WC-Co hardmetal with addition of the TiC0.9 phase. For comparison, physical and mechanical properties of the WC-Co hardmetals before modification were tested.

Resistance to pyridine-based inhibitor KF116 reveals an unexpected role of integrase in HIV-1 Gag-Pol polyprotein proteolytic processing.

PubMed

Hoyte, Ashley C; Jamin, Augusta V; Koneru, Pratibha C; Kobe, Matthew J; Larue, Ross C; Fuchs, James R; Engelman, Alan N; Kvaratskhelia, Mamuka

2017-12-01

The pyridine-based multimerization selective HIV-1 integrase (IN) inhibitors (MINIs) are a distinct subclass of allosteric IN inhibitors. MINIs potently inhibit HIV-1 replication during virion maturation by inducing hyper- or aberrant IN multimerization but are largely ineffective during the early steps of viral replication. Here, we investigated the mechanism for the evolution of a triple IN substitution (T124N/V165I/T174I) that emerges in cell culture with a representative MINI, KF116. We show that HIV-1 NL4-3(IN T124N/V165I/T174I) confers marked (>2000-fold) resistance to KF116. Two IN substitutions (T124N/T174I) directly weaken inhibitor binding at the dimer interface of the catalytic core domain but at the same time markedly impair HIV-1 replication capacity. Unexpectedly, T124N/T174I IN substitutions inhibited proteolytic processing of HIV-1 polyproteins Gag and Gag-Pol, resulting in immature virions. Strikingly, the addition of the third IN substitution (V165I) restored polyprotein processing, virus particle maturation, and significant levels of replication capacity. These results reveal an unanticipated role of IN for polyprotein proteolytic processing during virion morphogenesis. The complex evolutionary pathway for the emergence of resistant viruses, which includes the need for the compensatory V165I IN substitution, highlights a relatively high genetic barrier exerted by MINI KF116. Additionally, we have solved the X-ray structure of the drug-resistant catalytic core domain protein, which provides means for rational development of second-generation MINIs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

First quadruple-glycine bridging mono-lanthanide-substituted borotungstate hybrids.

PubMed

Liu, Jiancai; Yu, Jing; Han, Qing; Wen, Yue; Chen, Lijuan; Zhao, Junwei

2016-10-18

A class of novel organic-inorganic hybrid lanthanide (Ln)-substituted Keggin-type borotungstates K 4 Na 4 H 4 [Ln 2 (gly) 4 (α-BW 11 O 39 ) 2 ]·23H 2 O [Ln = Ce 3+ (1), Pr 3+ (2), Nd 3+ (3), Sm 3+ (4), Eu 3+ (5), Tm 3+ (6); gly = glycine] have been synthesized from the reaction of K 8 [BW 11 O 39 H]·13H 2 O, NaAc·6H 2 O and Ln(NO 3 ) 3 ·6H 2 O by employing gly ligands as structure-stabilizing agents in the conventional aqueous solution system and structurally characterized by elemental analyses, IR spectroscopy, thermogravimetric (TG) analyses, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. The common prominent structural feature of isomorphic 1-6 is that all of them consist of two mono-Ln-substituted Keggin [Ln(α-BW 11 O 39 )] 6- fragments linked by four gly ligands, furnishing an intriguing dimeric assembly of the quadruple-gly-connective mono-Ln-substituted borotungstate, in which each carboxylic oxygen atom from gly ligands is bound to Ln 3+ cations in the μ 2 -O or μ 3 -O mode. To the best of our knowledge, 1-6 represent the first examples of inorganic-organic hybrid Ln-substituted borotungstates functionalized by quadruple amino acid bridges. The solid-state photoluminescence properties of 3-5 have been determined at ambient temperature and the photoluminescence emission spectra exhibit the characteristic emission bands derived from Ln 3+ centers. The thermostability of 1-6 has been studied and the thermal decomposition procedure of 3 has been comprehensively investigated with the assistance of variable-temperature PXRD patterns and variable-temperature IR spectra. Furthermore, magnetic susceptibility measurements of 1, 2 and 4 have been conducted.

Calibration of Multiple Poliovirus Molecular Clocks Covering an Extended Evolutionary Range▿ †

PubMed Central

Jorba, Jaume; Campagnoli, Ray; De, Lina; Kew, Olen

2008-01-01

We have calibrated five different molecular clocks for circulating poliovirus based upon the rates of fixation of total substitutions (Kt), synonymous substitutions (Ks), synonymous transitions (As), synonymous transversions (Bs), and nonsynonymous substitutions (Ka) into the P1/capsid region (2,643 nucleotides). Rates were determined over a 10-year period by analysis of sequences of 31 wild poliovirus type 1 isolates representing a well-defined phylogeny derived from a common imported ancestor. Similar rates were obtained by linear regression, the maximum likelihood/single-rate dated-tip method, and Bayesian inference. The very rapid Kt [(1.03 ± 0.10) × 10−2 substitutions/site/year] and Ks [(1.00 ± 0.08) × 10−2] clocks were driven primarily by the As clock [(0.96 ± 0.09) × 10−2], the Bs clock was ∼10-fold slower [(0.10 ± 0.03) × 10−2], and the more stochastic Ka clock was ∼30-fold slower [(0.03 ± 0.01) × 10−2]. Nonsynonymous substitutions at all P1/capsid sites, including the neutralizing antigenic sites, appeared to be constrained by purifying selection. Simulation of the evolution of third-codon positions suggested that saturation of synonymous transitions would be evident at 10 years and complete at ∼65 years of independent transmission. Saturation of synonymous transversions was predicted to be minimal at 20 years and incomplete at 100 years. The rapid evolution of the Kt, Ks, and As clocks can be used to estimate the dates of divergence of closely related viruses, whereas the slower Bs and Ka clocks may be used to explore deeper evolutionary relationships within and across poliovirus genotypes. PMID:18287242

Mineralogical, chemical, and crystallographic properties of supergene jarosite-group minerals from the Xitieshan Pb-Zn sulfide deposit, northern Tibetan Plateau, China

USGS Publications Warehouse

Chen, Lei; Li, Jian-Wei; Rye, Robert O.; Benzel, William H.; Lowers, H.A.; He, Ming-Zhong

2013-01-01

Supergene jarosite-group minerals are widespread in weathering profiles overlying Pb-Zn sulfide ores at Xitieshan, northern Tibetan Plateau, China. They consist predominantly of K-deficient natrojarosite, with lesser amounts of K-rich natrojarosite and plumbojarosite. Electron microprobe (EMP) analyses, scanning electron microcopy (SEM) investigation, and X-ray mapping reveal that the jarosite-group minerals are characterized by spectacular oscillatory zoning composed of alternating growth bands of K-deficient and K-bearing natrojarosite (K2O >1 wt.%). Plumbojarosite, whenever present, occurs as an overgrowth in the outermost bands, and its composition can be best represented by K0.29Na0.19Pb0.31Fe2.66Al0.22(SO4)1.65(PO4)0.31(AsO4)0.04(OH)7.37. The substitution of monovalent for divalent cations at the A site of plumbojarosite is charge balanced by the substitution of five-valent for six-valent anions in XO,4/sub> at the X site. Thermogravimetric analysis (TGA) of representative samples reveal mass losses of 11.46 wt.% at 446.6 °C and 21.42 wt.% at 683.4 °C due to dehydroxylation and desulfidation, respectively. TGA data also indicate that the natrojarosite structure collapses at 446.6 °C, resulting in the formation of NaFe(SO4)2 and minor hematite. The decomposition products of NaFe(SO4) are hematite and Na,2SO4. Powder X-ray diffraction (XRD) analyses show that the jarosite-group minerals have mean unit-cell parameters of a=7.315 ä and c=016.598 ä. XRD and EMP data support the view that substitutions of Na for K in the A site and full Fe occupancy in the B site can considerably decrease the unit-cell parameter c, but only slightly increase a. The results from this study suggest that the observed oscillatory zoning of jarosite-group minerals at Xitieshan resulted mainly from substitutions of K for Na at the A site and P for S at the X site.

The nearly neutral and selection theories of molecular evolution under the fisher geometrical framework: substitution rate, population size, and complexity.

PubMed

Razeto-Barry, Pablo; Díaz, Javier; Vásquez, Rodrigo A

2012-06-01

The general theories of molecular evolution depend on relatively arbitrary assumptions about the relative distribution and rate of advantageous, deleterious, neutral, and nearly neutral mutations. The Fisher geometrical model (FGM) has been used to make distributions of mutations biologically interpretable. We explored an FGM-based molecular model to represent molecular evolutionary processes typically studied by nearly neutral and selection models, but in which distributions and relative rates of mutations with different selection coefficients are a consequence of biologically interpretable parameters, such as the average size of the phenotypic effect of mutations and the number of traits (complexity) of organisms. A variant of the FGM-based model that we called the static regime (SR) represents evolution as a nearly neutral process in which substitution rates are determined by a dynamic substitution process in which the population's phenotype remains around a suboptimum equilibrium fitness produced by a balance between slightly deleterious and slightly advantageous compensatory substitutions. As in previous nearly neutral models, the SR predicts a negative relationship between molecular evolutionary rate and population size; however, SR does not have the unrealistic properties of previous nearly neutral models such as the narrow window of selection strengths in which they work. In addition, the SR suggests that compensatory mutations cannot explain the high rate of fixations driven by positive selection currently found in DNA sequences, contrary to what has been previously suggested. We also developed a generalization of SR in which the optimum phenotype can change stochastically due to environmental or physiological shifts, which we called the variable regime (VR). VR models evolution as an interplay between adaptive processes and nearly neutral steady-state processes. When strong environmental fluctuations are incorporated, the process becomes a selection model in which evolutionary rate does not depend on population size, but is critically dependent on the complexity of organisms and mutation size. For SR as well as VR we found that key parameters of molecular evolution are linked by biological factors, and we showed that they cannot be fixed independently by arbitrary criteria, as has usually been assumed in previous molecular evolutionary models.

The Nearly Neutral and Selection Theories of Molecular Evolution Under the Fisher Geometrical Framework: Substitution Rate, Population Size, and Complexity

PubMed Central

Razeto-Barry, Pablo; Díaz, Javier; Vásquez, Rodrigo A.

2012-01-01

The general theories of molecular evolution depend on relatively arbitrary assumptions about the relative distribution and rate of advantageous, deleterious, neutral, and nearly neutral mutations. The Fisher geometrical model (FGM) has been used to make distributions of mutations biologically interpretable. We explored an FGM-based molecular model to represent molecular evolutionary processes typically studied by nearly neutral and selection models, but in which distributions and relative rates of mutations with different selection coefficients are a consequence of biologically interpretable parameters, such as the average size of the phenotypic effect of mutations and the number of traits (complexity) of organisms. A variant of the FGM-based model that we called the static regime (SR) represents evolution as a nearly neutral process in which substitution rates are determined by a dynamic substitution process in which the population’s phenotype remains around a suboptimum equilibrium fitness produced by a balance between slightly deleterious and slightly advantageous compensatory substitutions. As in previous nearly neutral models, the SR predicts a negative relationship between molecular evolutionary rate and population size; however, SR does not have the unrealistic properties of previous nearly neutral models such as the narrow window of selection strengths in which they work. In addition, the SR suggests that compensatory mutations cannot explain the high rate of fixations driven by positive selection currently found in DNA sequences, contrary to what has been previously suggested. We also developed a generalization of SR in which the optimum phenotype can change stochastically due to environmental or physiological shifts, which we called the variable regime (VR). VR models evolution as an interplay between adaptive processes and nearly neutral steady-state processes. When strong environmental fluctuations are incorporated, the process becomes a selection model in which evolutionary rate does not depend on population size, but is critically dependent on the complexity of organisms and mutation size. For SR as well as VR we found that key parameters of molecular evolution are linked by biological factors, and we showed that they cannot be fixed independently by arbitrary criteria, as has usually been assumed in previous molecular evolutionary models. PMID:22426879

Apparent loss-of-function mutant GPCRs revealed as constitutively desensitized receptors.

PubMed

Wilbanks, Alyson M; Laporte, Stéphane A; Bohn, Laura M; Barak, Larry S; Caron, Marc G

2002-10-08

The DRY motif is a triplet amino acid sequence (aspartic acid, arginine, and tyrosine) that is highly conserved in G protein-coupled receptors (GPCRs). Recently, we have shown that a molecular determinant for nephrogenic diabetes insipidus, the vasopressin receptor with a substitution at the DRY motif arginine (V2R R137H), is a constitutively desensitized receptor that is unable to couple to G proteins due to its constitutive association with beta-arrestin [Barak, L. S. (2001) Proc. Natl. Acad. Sci. U.S.A. 98, 93-98]. Additionally, the mutant receptors are localized in endocytic vesicles, identical to wild-type receptors stimulated with agonist. In this study, we asked whether the constitutively desensitized phenotype observed in the V2R R137H represents a general paradigm that may be extended to other GPCRs. We show that arginine substitutions in the DRY motifs of the alpha(1B) adrenergic receptor (alpha(1B)-AR) and angiotensin II type 1A receptor (AT(1A)R) result in receptors that are uncoupled from G proteins, associated with beta-arrestins, and found localized in endocytic vesicles rather than at the plasma membrane in the absence of agonists. The localization of the alpha(1B)-ARs and AT(1A)Rs with arginine substitutions can be restored to the plasma membrane by either using selective antagonists or preventing the endocytosis of the beta-arrestin-receptor complexes. These results indicate that the arginine residue of the DRY motif is essential for preserving the localization of the inactive receptor complex. Furthermore, constitutive desensitization may underlie some loss-of-function receptor phenotypes and represent an unappreciated mechanism of hormonal resistance.

Comparison of base flows to selected streamflow statistics representative of 1930-2002 in West Virginia

USGS Publications Warehouse

Wiley, Jeffrey B.

2012-01-01

Base flows were compared with published streamflow statistics to assess climate variability and to determine the published statistics that can be substituted for annual and seasonal base flows of unregulated streams in West Virginia. The comparison study was done by the U.S. Geological Survey, in cooperation with the West Virginia Department of Environmental Protection, Division of Water and Waste Management. The seasons were defined as winter (January 1-March 31), spring (April 1-June 30), summer (July 1-September 30), and fall (October 1-December 31). Differences in mean annual base flows for five record sub-periods (1930-42, 1943-62, 1963-69, 1970-79, and 1980-2002) range from -14.9 to 14.6 percent when compared to the values for the period 1930-2002. Differences between mean seasonal base flows and values for the period 1930-2002 are less variable for winter and spring, -11.2 to 11.0 percent, than for summer and fall, -47.0 to 43.6 percent. Mean summer base flows (July-September) and mean monthly base flows for July, August, September, and October are approximately equal, within 7.4 percentage points of mean annual base flow. The mean of each of annual, spring, summer, fall, and winter base flows are approximately equal to the annual 50-percent (standard error of 10.3 percent), 45-percent (error of 14.6 percent), 75-percent (error of 11.8 percent), 55-percent (error of 11.2 percent), and 35-percent duration flows (error of 11.1 percent), respectively. The mean seasonal base flows for spring, summer, fall, and winter are approximately equal to the spring 50- to 55-percent (standard error of 6.8 percent), summer 45- to 50-percent (error of 6.7 percent), fall 45-percent (error of 15.2 percent), and winter 60-percent duration flows (error of 8.5 percent), respectively. Annual and seasonal base flows representative of the period 1930-2002 at unregulated streamflow-gaging stations and ungaged locations in West Virginia can be estimated using previously published values of statistics and procedures.

Technical change in forest sector models: the global forest products model approach

Treesearch

Joseph Buongiorno; Sushuai Zhu

2015-01-01

Technical change is developing rapidly in some parts of the forest sector, especially in the pulp and paper industry where wood fiber is being substituted by waste paper. In forest sector models, the processing of wood and other input into products is frequently represented by activity analysis (input–output). In this context, technical change translates in changes...

40 CFR 419.12 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... organic carbon (TOC) based upon an analysis of any single grab or composite sample. (2) If contaminated... contaminated runoff which exceeds 15 mg/l oil and grease or 110 mg/l TOC is not commingled or treated with any... substitute TOC as a parameter in lieu of COD. A TOC effluent limitation shall be based on effluent data from...

40 CFR 419.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (TOC) based upon an analysis of any single grab or composite sample. (2) If contaminated runoff is... which exceeds 15 mg/l oil and grease or 110 mg/l TOC is not commingled or treated with any other type of... the effluent exceeds 1,000 mg/l (1,000 ppm), the permitting authority may substitute TOC as a...

40 CFR 419.43 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 110 mg/l total organic carbon (TOC) based upon an analysis of any single grab or composite sample. (2... solely of contaminated runoff which exceeds 110 mg/l TOC is not commingled or treated with any other type... effluent exceeds 1,000 mg/l (1,000 ppm), the permitting authority may substitute TOC as a parameter in lieu...

Synthesis of (±)-amathaspiramide F and discovery of an unusual stereocontrolling element for the [2,3]-Stevens rearrangement.

PubMed

Soheili, Arash; Tambar, Uttam K

2013-10-04

A formal total synthesis of (±)-amathaspiramide F through a tandem palladium-catalyzed allylic amination/[2,3]-Stevens rearrangement is reported. The unexpected diastereoselectivity of the [2,3]-Stevens rearrangement was controlled by the substitution patterns of an aromatic ring. This discovery represents a new stereocontrolling element for [2,3]-sigmatropic rearrangements in complex molecular settings.

Ionic conductors for solid oxide fuel cells

DOEpatents

Krumpelt, Michael; Bloom, Ira D.; Pullockaran, Jose D.; Myles, Kevin M.

1993-01-01

An electrolyte that operates at temperatures ranging from 600.degree. C. to 800.degree. C. is provided. The electrolyte conducts charge ionically as well as electronically. The ionic conductors include molecular framework structures having planes or channels large enough to transport oxides or hydrated protons and having net-positive or net-negative charges. Representative molecular framework structures include substituted aluminum phosphates, orthosilicates, silicoaluminates, cordierites, apatites, sodalites, and hollandites.

Can spatial patterns along climatic gradients predict ecosystem responses to climate change? Experimenting with reaction-diffusion simulations.

PubMed

Roitberg, Elena; Shoshany, Maxim

2017-01-01

Following a predicted decline in water resources in the Mediterranean Basin, we used reaction-diffusion equations to gain a better understanding of expected changes in properties of vegetation patterns that evolve along the rainfall transition between semi-arid and arid rainfall regions. Two types of scenarios were investigated: the first, a discrete scenario, where the potential consequences of climate change are represented by patterns evolving at discrete rainfall levels along a rainfall gradient. This scenario concerns space-for-time substitutions characteristic of the rainfall gradient hypothesis. The second, a continuous scenario, represents explicitly the effect of rainfall decline on patterns which evolved at different rainfall levels along the rainfall gradient prior to the climate change. The eccentricity of patterns that emerge through these two scenarios was found to decrease with decreasing rainfall, while their solidity increased. Due to their inverse modes of change, their ratio was found to be a highly sensitive indicator for pattern response to rainfall decline. An eccentricity ratio versus rainfall (ER:R) line was generalized from the results of the discrete experiment, where ERs above this line represent developed (recovered) patterns and ERs below this line represent degraded patterns. For the rainfall range of 1.2 to 0.8 mm/day, the continuous rainfall decline experiment with ERs that lie above the ER:R line, yielded patterns less affected by rainfall decline than would be expected according to the discrete representation of ecosystems' response. Thus, for this range, space-for-time substitution represents an overestimation of the consequences of the expected rainfall decline. For rainfall levels below 0.8 mm/day, eccentricity ratios from the discrete and continuous experiments practically converge to the same trend of pattern change along the ER:R line. Thus, the rainfall gradient hypothesis may be valid for regions characterized by this important rainfall range, which typically include desert fringe ecosystems.

ortho-Substituted (Aryl)(3-nitrobenzo[b]thiophen-2-yl)amines: Study of the Electrochemical Behavior

NASA Astrophysics Data System (ADS)

Cosimelli, Barbara; Lanza, Camilla Zaira; Scavetta, Erika; Severi, Elda; Spinelli, Domenico; Stenta, Marco; Tonelli, Domenica

2009-08-01

The reduction potentials of the title compounds 4 have been measured by cyclic voltammetry. The effect of the substituents has been evaluated by using a linear free energy relationship treatment, thus evidencing that the present ortho-substituents affect the Epc values basically by electronic effects. A comparison with data previously collected on ortho-substituted (aryl)(2-nitrobenzo[b]thiophen-3-yl)amines 3 has provided some interesting information. Different electrochemical behaviors are observed during the reduction (a reversible process and an irreversible process are operating in 3 and 4, respectively): to elucidate the reasons for this different behavior, the "reversible" reduction potentials of 5 and of 6 have been measured. Moreover, higher susceptibility constants have been calculated for compounds of series 4 with respect to those of series 3 (ρ4 = 329 and ρ3 = 182, respectively). A rationale for all of these findings has been offered.

Efficient chemoenzymatic dynamic kinetic resolution of 1-heteroaryl ethanols.

PubMed

Vallin, Karl S A; Wensbo Posaric, David; Hamersak, Zdenko; Svensson, Mats A; Minidis, Alexander B E

2009-12-18

The scope and limitation of the combined ruthenium-lipase induced dynamic kinetic resolution (DKR) through O-acetylation of racemic heteroaromatic secondary alcohols, i.e., 1-heteroaryl substituted ethanols, was investigated. After initial screening of reaction conditions, Candida antarctica lipase B (Novozyme 435, N435) together with 4-chloro-phenylacetate as acetyl-donor for kinetic resolution (KR), in conjunction with the ruthenium-based Shvo catalyst for substrate racemization in toluene at 80 degrees C, enabled DKR with high yields and stereoselectivity of various 1-heteroaryl ethanols, such as oxadiazoles, isoxazoles, 1H-pyrazole, or 1H-imidazole. In addition, DFT calculations based on a simplified catalyst complex model for the catalytic (de)hydrogenation step are in agreement with the previously reported outer sphere mechanism. These results support the further understanding of the mechanistic aspects behind the difference in reactivity of 1-heteroaryl substituted ethanols in comparison to reference substrates, as often referred to in the literature.

A nucleotide substitution in one of the beta-tubulin genes of Trichoderma viride confers resistance to the antimitotic drug methyl benzimidazole-2-yl-carbamate.

PubMed

Goldman, G H; Temmerman, W; Jacobs, D; Contreras, R; Van Montagu, M; Herrera-Estrella, A

1993-07-01

We characterized a Trichoderma viride strain that is resistant to the antimitotic drug methyl benzimidazole-2-yl-carbamate (MBC). This species has two beta-tubulin genes (tub1 and tub2) and by reverse genetics we showed that a mutation in the tub2 gene confers MBC resistance in this strain. Comparison of the tub2 sequence of the mutant strain with that of the wild type revealed that a single amino acid substitution of tyrosine for histidine at a position 6 is responsible for the MBC tolerance. Furthermore, we showed that this gene can be used as a homologous dominant selectable marker in T. viride transformation. Both tubulin genes were completely sequenced. They differ by 48 residues and the degree of identity between their deduced amino acid sequences is 86.3%.

Fracture properties of concrete specimens made from alkali activated binders

NASA Astrophysics Data System (ADS)

Šimonová, Hana; Kucharczyková, Barbara; Topolář, Libor; Bílek, Vlastimil, Jr.; Keršner, Zbyněk

2017-09-01

The aim of this paper is to quantify crack initiation and other fracture properties - effective fracture toughness and specific fracture energy - of two types of concrete with an alkali activated binder. The beam specimens with a stress concentrator were tested in a three-point bending test after 28, 90, and 365 days of maturing. Records of fracture tests in the form of load versus deflection (P-d) diagrams were evaluated using effective crack model and work-of-fracture method and load versus mouth crack opening displacement (P-CMOD) diagrams were evaluated using the Double-K fracture model. The initiation of cracks during the fracture tests for all ages was also monitored by the acoustic emission method. The higher value of monitored mechanical fracture parameters of concrete with alkali activated blast furnace slag were achieved with substitution blast furnace slag by low calcium fly ash in comparison with substitution by cement kiln dust.

Effects of nucleoside analog incorporation on DNA binding to the DNA binding domain of the GATA-1 erythroid transcription factor.

PubMed

Foti, M; Omichinski, J G; Stahl, S; Maloney, D; West, J; Schweitzer, B I

1999-02-05

We investigate here the effects of the incorporation of the nucleoside analogs araC (1-beta-D-arabinofuranosylcytosine) and ganciclovir (9-[(1,3-dihydroxy-2-propoxy)methyl] guanine) into the DNA binding recognition sequence for the GATA-1 erythroid transcription factor. A 10-fold decrease in binding affinity was observed for the ganciclovir-substituted DNA complex in comparison to an unmodified DNA of the same sequence composition. AraC substitution did not result in any changes in binding affinity. 1H-15N HSQC and NOESY NMR experiments revealed a number of chemical shift changes in both DNA and protein in the ganciclovir-modified DNA-protein complex when compared to the unmodified DNA-protein complex. These changes in chemical shift and binding affinity suggest a change in the binding mode of the complex when ganciclovir is incorporated into the GATA DNA binding site.

Efficient n-type doping of zinc-blende III-V semiconductor nanowires

NASA Astrophysics Data System (ADS)

Besteiro, Lucas V.; Tortajada, Luis; Souto, J.; Gallego, L. J.; Chelikowsky, James R.; Alemany, M. M. G.

2014-03-01

We demonstrate that it is preferable to dope III-V semiconductor nanowires by n-type anion substitution as opposed to cation substitution. Specifically, we show the dopability of zinc-blende nanowires is more efficient when the dopants are placed at the anion site as quantified by formation energies and the stabilization of DX-like defect centers. The comparison with previous work on n - type III-V semiconductor nanocrystals also allows to determine the role of dimensionality and quantum confinement on doping characteristics of materials. Our results are based on first-principles calculations of InP nanowires by using the PARSEC code. Work supported by the Spanish MICINN (FIS2012-33126) and Xunta de Galicia (GPC2013-043) in conjunction with FEDER. JRC acknowledges support from DoE (DE-FG02-06ER46286 and DESC0008877). Computational support was provided in part by CESGA.

Antiviral Activity and Resistance Analysis of NS3/4A Protease Inhibitor Grazoprevir and NS5A Inhibitor Elbasvir in Hepatitis C Virus GT4 Replicons.

PubMed

Asante-Appiah, Ernest; Curry, Stephanie; McMonagle, Patricia; Ingravallo, Paul; Chase, Robert; Nickle, David; Qiu, Ping; Howe, Anita; Lahser, Frederick C

2017-07-01

Although genotype 4 (GT4)-infected patients represent a minor overall percentage of the global hepatitis C virus (HCV)-infected population, the high prevalence of the genotype in specific geographic regions coupled with substantial sequence diversity makes it an important genotype to study for antiviral drug discovery and development. We evaluated two direct-acting antiviral agents-grazoprevir, an HCV NS3/4A protease inhibitor, and elbasvir, an HCV NS5A inhibitor-in GT4 replicons prior to clinical studies in this genotype. Following a bioinformatics analysis of available GT4 sequences, a set of replicons bearing representative GT4 clinical isolates was generated. For grazoprevir, the 50% effective concentration (EC 50 ) against the replicon bearing the reference GT4a (ED43) NS3 protease and NS4A was 0.7 nM. The median EC 50 for grazoprevir against chimeric replicons encoding NS3/4A sequences from GT4 clinical isolates was 0.2 nM (range, 0.11 to 0.33 nM; n = 5). The difficulty in establishing replicons bearing NS3/4A resistance-associated substitutions was substantially overcome with the identification of a G162R adaptive substitution in NS3. Single NS3 substitutions D168A/V identified from de novo resistance selection studies reduced grazoprevir antiviral activity by 137- and 47-fold, respectively, in the background of the G162R replicon. For elbasvir, the EC 50 against the replicon bearing the reference full-length GT4a (ED43) NS5A gene was 0.0002 nM. The median EC 50 for elbasvir against chimeric replicons bearing clinical isolates from GT4 was 0.0007 nM (range, 0.0002 to 34 nM; n = 14). De novo resistance selection studies in GT4 demonstrated a high propensity to suppress the emergence of amino acid substitutions that confer high-potency reductions to elbasvir. Phenotypic characterization of the NS5A amino acid substitutions identified (L30F, L30S, M31V, and Y93H) indicated that they conferred 15-, 4-, 2.5-, and 7.5-fold potency losses, respectively, to elbasvir. The activity profiles of grazoprevir and elbasvir supported the testing of the direct-acting antivirals in clinical studies. Copyright © 2017 American Society for Microbiology.

Inhibition of the pore-forming protein perforin by a series of aryl-substituted isobenzofuran-1(3H)-ones.

PubMed

Spicer, Julie A; Huttunen, Kristiina M; Miller, Christian K; Denny, William A; Ciccone, Annette; Browne, Kylie A; Trapani, Joseph A

2012-02-01

An aryl-substituted isobenzofuran-1(3H)-one lead compound was identified from a high throughput screen designed to find inhibitors of the lymphocyte pore-forming protein perforin. A series of analogs were then designed and prepared, exploring structure-activity relationships through variation of 2-thioxoimidazolidin-4-one and furan subunits on an isobenzofuranone core. The ability of the resulting compounds to inhibit the lytic activity of both isolated perforin protein and perforin delivered in situ by intact KHYG-1 natural killer effector cells was determined. Several compounds showed excellent activity at concentrations that were non-toxic to the killer cells. This series represents a significant improvement on previous classes of compounds, being substantially more potent and largely retaining activity in the presence of serum. Copyright © 2011 Elsevier Ltd. All rights reserved.

Spiroborate Ester-Mediated Asymmetric Synthesis of β-Hydroxy Ethers and its Conversion to Highly Enantiopure β-Amino Ethers

PubMed Central

Huang, Kun; Ortiz-Marciales, Margarita; Correa, Wildeliz; Pomales, Edgardo; López, Xaira Y.

2009-01-01

Borane-mediated reduction of aryl and alkyl ketones with α-aryl- and α-pyridyloxy groups affords β-hydroxy ethers in high enantiomeric purity (up to 99% ee) and in good yield, using as catalyst 10 mol % of spiroborate ester 1 derived from (S)-diphenylprolinol. Representative β-hydroxy ethers are successfully converted to β-amino ethers, with minor epimerization, by phthalimide substitution under Mitsunobu’s conditions followed by hydrazinolysis, to obtain primary amino ethers or by imide reduction with borane to afford β-2,3-dihydro-1H-isoindol ethers. Non-racemic Mexiletine and nAChR analogues with potential biological activity are also synthesized in excellent yield by mesylation of key β-hydroxy pyridylethers and substitution with 5, 6 and 7 member ring heterocyclic amines. PMID:19413288

Coralline hydroxyapatite bone graft substitutes.

PubMed

Elsinger, E C; Leal, L

1996-01-01

The authors present a review of the various bone grafts currently available with special attention to coral bone grafts. Several of the benefits of coralline hydroxyapatite bone graft substitutes, such as safety and biocompatibility, will be addressed in this article, part of an ongoing investigation of coral bone grafts used in triple arthrodesis procedures. To date, eight cases have been performed. In seven cases, granular chips were employed to pack the subtalar joint. The final case, presented in this article, represents a 26-year-old male who, 2 years previously, sustained a calcaneal fracture with resultant shortening along the lateral column. A coralline hydroxyapatite block was used at the calcaneocuboid joint to achieve distraction. Clinically, the patient is progressing well at 10 months postoperatively. Radiographically, one can still clearly appreciate the margins of the bone graft at 5 months.

ETA-MACRO: A user's guide

NASA Astrophysics Data System (ADS)

Manne, A. S.

1981-02-01

The ETA-MACRO model is designed to estimate the extent of two way linkage between the energy sector and the balance of the economy. It represents a merger between ETA (a process analysis for energy technology assessment) together with a macroeconomic growth model providing for substitution between capital, labor, and energy inputs. The ETA-MACRO allows explicitly for: (1) energy economy interactions; (2) cost effective conservation; (3) interfuel substitution, and (4) new supply technologies, each with its own difficulties and uncertainties on dates and rates of introduction. This user's guide includes an overview of the model, an illustrative application to long term US energy projections, and technical descriptions of the macro and ETA submodels. It also includes an analysis of how market penetration rates may be related to the profitability of new technologies. Finally, the appendices provide a detailed guide to the computer implementation.

Effect of substitutional defects on Kambersky damping in L10 magnetic materials

NASA Astrophysics Data System (ADS)

Qu, T.; Victora, R. H.

2015-02-01

Kambersky damping, representing the loss of magnetic energy from the electrons to the lattice through the spin orbit interaction, is calculated for L10 FePt, FePd, CoPt, and CoPd alloys versus chemical degree of order. When more substitutional defects exist in the alloys, damping is predicted to increase due to the increase of the spin-flip channels allowed by the broken symmetry. It is demonstrated that this corresponds to an enhanced density of states (DOS) at the Fermi level, owing to the rounding of the DOS with loss of long-range order. Both the damping and the DOS of the Co-based alloy are found to be less affected by the disorder. Pd-based alloys are predicted to have lower damping than Pt-based alloys, making them more suitable for high density spintronic applications.

A comparison of classical and H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism in wild type and EK211 cattle following intracranial inoculation

USDA-ARS?s Scientific Manuscript database

In 2006, a case of H-type bovine spongiform encephalopathy (BSE-H) was diagnosed in a cow that was associated with a heritable polymorphism in the bovine prion protein gene (PRNP) resulting in a lysine for glutamine amino acid substitution at codon 211 (called E211K) of the prion protein. Although t...

Microwave-Assisted Synthesis of Phenothiazine and Quinoline Derivatives

PubMed Central

Găină, Luiza; Cristea, Castelia; Moldovan, Claudia; Porumb, Dan; Surducan, Emanoil; Deleanu, Călin; Mahamoud, Abdalah; Barbe, Jacques; Silberg, Ioan A.

2007-01-01

Application of a dynamic microwave power system in the chemical synthesis of some phenothiazine and quinoline derivatives is described. Heterocyclic ring formation, aromatic nucleophilic substitution and heterocyclic aldehydes/ketones condensation reactions were performed on solid support, or under solvent free reaction conditions. The microwave-assisted Duff formylation of phenothiazine was achieved. Comparison of microwave-assisted synthesis with the conventional synthetic methods demonstrates advantages related to shorter reaction times and in some cases better reaction yields.

Operating Room Telephone Microbial Flora

DTIC Science & Technology

2005-05-24

times of the bacteria most frequently implicated in surgical site infections on hands and inanimate surfaces . These bacteria are: S . aureus, CNS...variants of S . aureus and Enterococcus spp. Due to the lack of studies specific to telephone surfaces , we also used plastic surfaces as a substitute search...comparison with tube Coagulase test on S . aureus isolates has been found to have a relative sensitivity of 99.4%, a relative specificity of 95.5% and

Primary Stability of Zirconium vs Titanium Implants: An In Vitro Comparison

DTIC Science & Technology

2015-06-05

Zirconia implant and 4x11.5 Titanium implant placed in artificial bone ( polyurethane foam ) at .08 rotations /sec…………………………………28   viii...measurements as they relate to primary Implant Stability. Artificial Bone made of solid ridged polyurethane foam was used as an alternative test...30 pound per cubic foot solid rigid polyurethane blocks used to substitute human cancellous bone

Candida funiuensi sp. nov., a cellobiose-fermenting yeast species isolated from rotten wood.

PubMed

Wang, Yun; Ren, Yong-Cheng; Zhang, Zheng-Tian; Wu, Fu-Hua; Ke, Tao; Hui, Feng-Li

2015-06-01

Two strains of an asexual cellobiose-fermenting yeast species were isolated from rotten wood samples collected in Funiu Mountain Nature Reserve in Henan Province, central China. Molecular phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) rDNA showed that these strains belonged to the Candida kruisii clade, with Candida kruisii and Candida cretensis as their closest phylogenetic neighbours. The nucleotide differences between the novel strains and the type strains of C. kruisii and C. cretensis were 30 and 36 substitutions, respectively, in the D1/D2 LSU rDNA, 40 and 44 substitutions, respectively, in the ITS region and 19 and 23 substitutions, respectively, in the SSU rDNA. The novel strains can also be distinguished from their closest described species, C. kruisii and C. cretensis, by a number of physiological characteristics, and represent a novel species of the genus Candida, for which the name Candida funiuensis sp. nov. is proposed. The type strain is NYNU 14625T ( = CICC 33050T = CBS 13911T). The Mycobank number is MB 811503.

Bone tissue engineering: state of the art and future trends.

PubMed

Salgado, António J; Coutinho, Olga P; Reis, Rui L

2004-08-09

Although several major progresses have been introduced in the field of bone regenerative medicine during the years, current therapies, such as bone grafts, still have many limitations. Moreover, and in spite of the fact that material science technology has resulted in clear improvements in the field of bone substitution medicine, no adequate bone substitute has been developed and hence large bone defects/injuries still represent a major challenge for orthopaedic and reconstructive surgeons. It is in this context that TE has been emerging as a valid approach to the current therapies for bone regeneration/substitution. In contrast to classic biomaterial approach, TE is based on the understanding of tissue formation and regeneration, and aims to induce new functional tissues, rather than just to implant new spare parts. The present review pretends to give an exhaustive overview on all components needed for making bone tissue engineering a successful therapy. It begins by giving the reader a brief background on bone biology, followed by an exhaustive description of all the relevant components on bone TE, going from materials to scaffolds and from cells to tissue engineering strategies, that will lead to "engineered" bone. Scaffolds processed by using a methodology based on extrusion with blowing agents.

A camel-derived MERS-CoV with a variant spike protein cleavage site and distinct fusion activation properties

PubMed Central

Millet, Jean Kaoru; Goldstein, Monty E; Labitt, Rachael N; Hsu, Hung-Lun; Daniel, Susan; Whittaker, Gary R

2016-01-01

Middle East respiratory syndrome coronavirus (MERS-CoV) continues to circulate in both humans and camels, and the origin and evolution of the virus remain unclear. Here we characterize the spike protein of a camel-derived MERS-CoV (NRCE-HKU205) identified in 2013, early in the MERS outbreak. NRCE-HKU205 spike protein has a variant cleavage motif with regard to the S2′ fusion activation site—notably, a novel substitution of isoleucine for the otherwise invariant serine at the critical P1′ cleavage site position. The substitutions resulted in a loss of furin-mediated cleavage, as shown by fluorogenic peptide cleavage and western blot assays. Cell–cell fusion and pseudotyped virus infectivity assays demonstrated that the S2′ substitutions decreased spike-mediated fusion and viral entry. However, cathepsin and trypsin-like protease activation were retained, albeit with much reduced efficiency compared with the prototypical EMC/2012 human strain. We show that NRCE-HKU205 has more limited fusion activation properties possibly resulting in more restricted viral tropism and may represent an intermediate in the complex pattern of MERS-CoV ecology and evolution. PMID:27999426

Novel thiophene-based cycloruthenated compounds: synthesis, characterization, and reactivity.

PubMed

Cuesta, Luciano; Maluenda, Irene; Soler, Tatiana; Navarro, Rafael; Urriolabeitia, Esteban P

2011-01-03

The reactions between a series of thiophene-based imines with [(η(6)-C(6)H(6))RuCl(μ-Cl)](2), in a basic medium, and in MeCN give a family of ruthenacycles of stoichiometry [Ru(C^N)(NCMe)(4)]PF(6) (C^N = orthometalated thiopheneimine). In these species, the C-H activation process is produced in most cases at the thiophene ring. When two C-H bonds are competing (thiophene vs aryl), the cyclometalation can be driven regioselectively to the thiophene unit or to the aryl ring as a function of the location of the iminic C=N bond. Cyclometalation can also be oriented to positions 2 or 3 of the thiophene depending on the situation of the imine in the heterocycle (3 or 2, respectively). In all studied cases, the η(6)-C(6)H(6) ligand was substituted by acetonitrile. The X-ray structures of two representative complexes have been determined. These thiophene-based metallacycles react with iodine under very mild conditions affording, after hydrolysis, substituted 3-iodo-2-formyl(benzo)thiophenes or substituted 2-iodo-3-formyl(benzo)thiophenes, as a function of the organometallic precursor.

Adaptation of avian influenza A (H6N1) virus from avian to human receptor-binding preference

PubMed Central

Wang, Fei; Qi, Jianxun; Bi, Yuhai; Zhang, Wei; Wang, Min; Zhang, Baorong; Wang, Ming; Liu, Jinhua; Yan, Jinghua; Shi, Yi; Gao, George F

2015-01-01

The receptor-binding specificity of influenza A viruses is a major determinant for the host tropism of the virus, which enables interspecies transmission. In 2013, the first human case of infection with avian influenza A (H6N1) virus was reported in Taiwan. To gather evidence concerning the epidemic potential of H6 subtype viruses, we performed comprehensive analysis of receptor-binding properties of Taiwan-isolated H6 HAs from 1972 to 2013. We propose that the receptor-binding properties of Taiwan-isolated H6 HAs have undergone three major stages: initially avian receptor-binding preference, secondarily obtaining human receptor-binding capacity, and recently human receptor-binding preference, which has been confirmed by receptor-binding assessment of three representative virus isolates. Mutagenesis work revealed that E190V and G228S substitutions are important to acquire the human receptor-binding capacity, and the P186L substitution could reduce the binding to avian receptor. Further structural analysis revealed how the P186L substitution in the receptor-binding site of HA determines the receptor-binding preference change. We conclude that the human-infecting H6N1 evolved into a human receptor preference. PMID:25940072

Nature of the Electrochemical Properties of Sulphur Substituted LiMn2O4 Spinel Cathode Material Studied by Electrochemical Impedance Spectroscopy

PubMed Central

Bakierska, Monika; Świętosławski, Michał; Dziembaj, Roman; Molenda, Marcin

2016-01-01

In this work, nanostructured LiMn2O4 (LMO) and LiMn2O3.99S0.01 (LMOS1) spinel cathode materials were comprehensively investigated in terms of electrochemical properties. For this purpose, electrochemical impedance spectroscopy (EIS) measurements as a function of state of charge (SOC) were conducted on a representative charge and discharge cycle. The changes in the electrochemical performance of the stoichiometric and sulphur-substituted lithium manganese oxide spinels were examined, and suggested explanations for the observed dependencies were given. A strong influence of sulphur introduction into the spinel structure on the chemical stability and electrochemical characteristic was observed. It was demonstrated that the significant improvement in coulombic efficiency and capacity retention of lithium cell with LMOS1 active material arises from a more stable solid electrolyte interphase (SEI) layer. Based on EIS studies, the Li ion diffusion coefficients in the cathodes were estimated, and the influence of sulphur on Li+ diffusivity in the spinel structure was established. The obtained results support the assumption that sulphur substitution is an effective way to promote chemical stability and the electrochemical performance of LiMn2O4 cathode material. PMID:28773819

Modelling the influence of inulin as a fat substitute in comminuted meat products on their physico-chemical characteristics and eating quality using a mixture design approach.

PubMed

Keenan, Derek F; Resconi, Virginia C; Kerry, Joseph P; Hamill, Ruth M

2014-03-01

The effects of fat substitution using two commercial inulin products on the physico-chemical properties and eating quality of a comminuted meat product (breakfast sausage) were modelled using a specialised response surface experiment specially developed for mixtures. 17 treatments were assigned representing a different substitution level for fat with inulin. Sausages were formulated to contain pork shoulder, back fat/inulin, water, rusk and seasoning (44.3, 18.7, 27.5, 7 and 2.5% w/w). Composition, sensory, instrumental texture and colour characteristics were assessed. Fructan analysis showed that inulin was unaffected by heat or processing treatments. Models showed increasing inulin inclusions decreased cook loss (p<0.0017) and improved emulsion stability (p<0.0001) but also resulted in greater textural and eating quality modification of sausages. Hardness values increased (p<0.0001) with increasing inulin concentration, with panellists also scoring products containing inulin as less tender (p<0.0112). Optimisation predicted two acceptable sausage formulations with significantly lower fat levels than the control, which would contain sufficient inulin to deliver a prebiotic health effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sensory substitution information informs locomotor adjustments when walking through apertures.

PubMed

Kolarik, Andrew J; Timmis, Matthew A; Cirstea, Silvia; Pardhan, Shahina

2014-03-01

The study assessed the ability of the central nervous system (CNS) to use echoic information from sensory substitution devices (SSDs) to rotate the shoulders and safely pass through apertures of different width. Ten visually normal participants performed this task with full vision, or blindfolded using an SSD to obtain information regarding the width of an aperture created by two parallel panels. Two SSDs were tested. Participants passed through apertures of +0, +18, +35 and +70 % of measured body width. Kinematic indices recorded movement time, shoulder rotation, average walking velocity across the trial, peak walking velocities before crossing, after crossing and throughout a whole trial. Analyses showed participants used SSD information to regulate shoulder rotation, with greater rotation associated with narrower apertures. Rotations made using an SSD were greater compared to vision, movement times were longer, average walking velocity lower and peak velocities before crossing, after crossing and throughout the whole trial were smaller, suggesting greater caution. Collisions sometimes occurred using an SSD but not using vision, indicating that substituted information did not always result in accurate shoulder rotation judgements. No differences were found between the two SSDs. The data suggest that spatial information, provided by sensory substitution, allows the relative position of aperture panels to be internally represented, enabling the CNS to modify shoulder rotation according to aperture width. Increased buffer space indicated by greater rotations (up to approximately 35 % for apertures of +18 % of body width) suggests that spatial representations are not as accurate as offered by full vision.

A Comparison of the β-Substitution Method and a Bayesian Method for Analyzing Left-Censored Data

PubMed Central

Huynh, Tran; Quick, Harrison; Ramachandran, Gurumurthy; Banerjee, Sudipto; Stenzel, Mark; Sandler, Dale P.; Engel, Lawrence S.; Kwok, Richard K.; Blair, Aaron; Stewart, Patricia A.

2016-01-01

Classical statistical methods for analyzing exposure data with values below the detection limits are well described in the occupational hygiene literature, but an evaluation of a Bayesian approach for handling such data is currently lacking. Here, we first describe a Bayesian framework for analyzing censored data. We then present the results of a simulation study conducted to compare the β-substitution method with a Bayesian method for exposure datasets drawn from lognormal distributions and mixed lognormal distributions with varying sample sizes, geometric standard deviations (GSDs), and censoring for single and multiple limits of detection. For each set of factors, estimates for the arithmetic mean (AM), geometric mean, GSD, and the 95th percentile (X0.95) of the exposure distribution were obtained. We evaluated the performance of each method using relative bias, the root mean squared error (rMSE), and coverage (the proportion of the computed 95% uncertainty intervals containing the true value). The Bayesian method using non-informative priors and the β-substitution method were generally comparable in bias and rMSE when estimating the AM and GM. For the GSD and the 95th percentile, the Bayesian method with non-informative priors was more biased and had a higher rMSE than the β-substitution method, but use of more informative priors generally improved the Bayesian method’s performance, making both the bias and the rMSE more comparable to the β-substitution method. An advantage of the Bayesian method is that it provided estimates of uncertainty for these parameters of interest and good coverage, whereas the β-substitution method only provided estimates of uncertainty for the AM, and coverage was not as consistent. Selection of one or the other method depends on the needs of the practitioner, the availability of prior information, and the distribution characteristics of the measurement data. We suggest the use of Bayesian methods if the practitioner has the computational resources and prior information, as the method would generally provide accurate estimates and also provides the distributions of all of the parameters, which could be useful for making decisions in some applications. PMID:26209598

Design of cryogenic tanks for launch vehicles

NASA Technical Reports Server (NTRS)

Copper, Charles; Pilkey, Walter D.; Haviland, John K.

1990-01-01

During the period since January 1990, work was concentrated on the problem of the buckling of the structure of an ALS (advanced launch systems) tank during the boost phase. The primary problem was to analyze a proposed hat stringer made by superplastic forming, and to compare it with an integrally stiffened stringer design. A secondary objective was to determine whether structural rings having the identical section to the stringers will provide adequate support against overall buckling. All of the analytical work was carried out with the TESTBED program on the CONVEX computer, using PATRAN programs to create models. Analyses of skin/stringer combinations have shown that the proposed stringer design is an adequate substitute for the integrally stiffened stringer. Using a highly refined mesh to represent the corrugations in the vertical webs of the hat stringers, effective values were obtained for cross-sectional area, moment of inertia, centroid height, and torsional constant. Not only can these values be used for comparison with experimental values, but they can also be used for beams to replace the stringers and frames in analytical models of complete sections of tank. The same highly refined model was used to represent a section of skin reinforced by a stringer and a ring segment in the configuration of a cross. It was intended that this would provide a baseline buckling analysis representing a basic mode, however, the analysis proved to be beyond the scope of the CONVEX computer. One quarter of this model was analyzed, however, to provide information on buckling between the spot welds. Models of large sections of the tank structure were made, using beam elements to model the stringers and frames. In order to represent the stiffening effects of pressure, stresses and deflections under pressure should first be obtained, and then the buckling analysis should be made on the structure so deflected. So far, uncharacteristic deflections under pressure were obtained from the TESTBED program using two types of structural elements. Similar results were obtained using the ANSYS program on a mainframe computer, although two finite element programs on microcomputers have yielded realistic results.

[Guidelines for substitution treatments in prison populations].

PubMed

Michel, L; Maguet, O

2005-01-01

Care access for the drug addict patients in prison (in particular for the treatments of substitution) in France is very unequal from one establishment to another. This reflects the great variability of the practices of substitution and especially the absence of consensus on the methods of adaptation of these practices to the prison environment. Because of difficulties expressed by prisoners and medical staff on this subject and of stakes (let us recall that approximately 30% of the prisoners are dependent or abusers of one or more psychoactive substances), the formulation of recommendations or of a good practices guide of substitution in prison appeared necessary. Work that we detail here answers a ordering of the Advisory Commission of the Treatments of Substitution (September 2001) whose authors are members. It was presented at the session April 2003. It results from the confrontation of a review of the literature (including legal texts and official reports concerning substitution, the organization of the care in prison environment and the lawful framework), with a vast investigation. The latter was carried out near medical staff (22 prisons), penitentiary staff (3 prisons, 27 people met including directors of these establishments) and prisoners (7 establishments, 28 prisoners met) in the form of individual talks (semi-directing interviews with evaluation of the type of existing device and its knowledge by the penitentiary staff and the prisoners; statement of the suggestions, needs and requests of the medical, penitentiary staffs and of the prisoners). In the whole visited prisons, 7.8% (870) of the prisoners received substitution treatments (6.35% by buprenorphine, 1.44% by methadone), representing a proportion of substituted drug addicts (870 substituted for an evaluation of 3,350 prisoners drug addicts among the 11,168 prisoners of the 22 visited prisons) notably lower than that in free environment (56%, ie 96,000 substituted for an evaluated population of drug addicts for heroin of 160,000). There are however considerable variations (from 0 to 16.2%) of the proportion of substituted of one establishment for the other according to the type of prison, of its size, its localization and the type of medical device present. If a consensus exists for methadone (daily delivery with sanitary control), the organization of the care relating to the buprenorphine is extremely variable from one establishment to another, often putting in difficulty as well the medical teams as the prisoners. One recommendation is essential: the formulation of an individualized therapeutic project. Thirteen other recommendations are made in the following fields: renewal of substitution treatments, initiation of substitution treatments, urinary controls, methods of prescription, methods of delivery, co-prescriptions, global care, confidentiality, files, exits and transfers, extractions, formation, accompaniment of the teams. These recommendations being formulated, many medical concerns remain present and several questions open. The report of joint mission IGAS/IGSJ of June 2001 on the health of the prisoners underlines the principal persistent gaps: hygiene and public health, treatment of the mental disorders, the follow-up of the sexual delinquents, handling ageing, handicap and the end of lifetime. In the same way, the difficulties listed in prison environment concerning substitution are only the exacerbation of those existing outside: the misuses and traffics are common in free environment, risk reduction in prison, as outside, handle with obstacles related to the penalization of the drug use and can hardly evolve except questioning the law of 1970. The prison practice opens also questions: that of the "duration" of the substitution, frequently posed by the prisoners; concern to see the prison becoming a privileged place of access to the care, combining sanction and care whereas the law of 1970 allows the alternative (care or sanction); that of the clinic of the misuse, particularly "readable" in prison environment; and finally the question of the shared secrecy, extremely delicate in prison context although clarified by the law of March 04, 2002.

Should patients with esophageal atresia be submitted to esophageal substitution before they start walking?

PubMed

Tannuri, U; Tannuri, A C A

2011-01-01

Esophagocoloplasty and gastric transposition are two major methods for esophageal substitution in children with esophageal atresia, and there is broad agreement that these operations should not be performed before the children start walking. However, there are some reported advantages of performing such operations in the first months of life or in the neonatal period. In this study, we compared our experience with esophageal substitution procedures performed in walking children with esophageal atresia, with the outcomes of children who had the operation before the third month of life reported in the literature. The purpose of this study was to establish if we have to wait until the children start walking before indicating the esophageal replacement procedure. From February 1978 to October 2009, 129 children with esophageal atresia underwent esophageal replacement in our hospital (99 colonic interpositions and 30 gastric transpositions). The records of these patients were reviewed for data regarding demographics, complications (leaks, graft failures, strictures, and graft torsion), and mortality and compared with those reported in the two main articles on esophageal replacement in the neonatal period or in patients less than 3 months of age. The main complication of our casuistic was cervical anastomosis leakage, which sealed spontaneously in all except in four patients. One patient of the esophagocoloplasty group developed graft necrosis and three patients in the gastric transposition group had gastric outlet obstruction, secondary to axial torsion of the stomach placed in the retrosternal space. The long-term outcome of the patients in both groups was considered good to excellent in terms of normal weight gain, absence of dysphagia, and other gastrointestinal symptoms. The comparisons of the main complications and mortality rates in walking children with esophageal substitutions performed in the first months of life showed that the incidences of cervical anastomotic leaks and graft failures were similar, but mortality rate in the first few months of life was significantly greater than that observed in our group of patients (P= 0.001). Based on the comparison of our results with those of published series, we conclude that the recommendation of performing esophagocoloplasty or total gastric transposition in children with esophageal atresia after they start walking is still valid. © 2010 Copyright the Authors. Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Chiral mutagenesis of insulin. Contribution of the B20-B23 beta-turn to activity and stability.

PubMed

Nakagawa, Satoe H; Hua, Qing-xin; Hu, Shi-Quan; Jia, Wenhua; Wang, Shuhua; Katsoyannis, Panayotis G; Weiss, Michael A

2006-08-04

Insulin contains a beta-turn (residues B20-B23) interposed between two receptor-binding elements, the central alpha-helix of the B chain (B9-B19) and its C-terminal beta-strand (B24-B28). The turn contains conserved glycines at B20 and B23. Although insulin exhibits marked conformational variability among crystal forms, these glycines consistently maintain positive phi dihedral angles within a classic type-I beta-turn. Because the Ramachandran conformations of GlyB20 and GlyB23 are ordinarily forbidden to L-amino acids, turn architecture may contribute to structure or function. Here, we employ "chiral mutagenesis," comparison of corresponding D- and L-Ala substitutions, to investigate this turn. Control substitutions are introduced at GluB21, a neighboring residue exhibiting a conventional (negative) phi angle. The D- and L-Ala substitutions at B23 are associated with a marked stereospecific difference in activity. Whereas the D-AlaB23 analog retains native activity, the L analog exhibits a 20-fold decrease in receptor binding. By contrast, D- and L-AlaB20 analogs each exhibit high activity. Stereospecific differences between the thermodynamic stabilities of the analogs are nonetheless more pronounced at B20 (delta deltaG(u) 2.0 kcal/mole) than at B23 (delta deltaG(u) 0.7 kcal/mole). Control substitutions at B21 are well tolerated without significant stereospecificity. Chiral mutagenesis thus defines the complementary contributions of these conserved glycines to protein stability (GlyB20) or receptor recognition (GlyB23).

Processing and electrical properties of gallium-substituted lead zirconate titanate ceramics

NASA Astrophysics Data System (ADS)

Hajra, Sugato; Sharma, Pulkit; Sahoo, Sushrisangita; Rout, P. K.; Choudhary, R. N. P.

2017-12-01

In the present paper, the effect of gallium (Ga) substitution on structural, microstructural, electrical conductivity of Pb(ZrTi)O3 (PZT) in the morphotropic phase boundary (MPB) region (i.e., Pb0.96Ga0.04(Zr0.48Ti0.52)0.99O3 (PGaZT-4)) was investigated. Increased grain density increases the resistivity of the Ga-modified PZT system. Preliminary structural analysis using X-ray diffraction pattern and data showed the existence of two phases [major tetragonal (T) and minor monoclinic (M)]. Field emission scanning electron micrograph (FESEM) showed the distribution of spherical as well as platelet type grains with small pores. The behavior of dielectric constant with temperature of PGaZT-4 exhibited the suppression of the ferroelectric phase transition [i.e., disappearance of Curie temperature ( T c)]. The complex impedance spectroscopy (CIS) technique helped to investigate the impedance parameters of PGaZT-4 in MPB region in a wide range of temperature (250-500 °C) and frequency (1-1000 kHz) region. The impedance parameters of the material are found to be strongly dependent on frequency of AC electric field and temperature. The substitution of gallium at the Pb site of PZT generally enhances the dielectric constant and decreases loss tangent. The AC conductivity vs frequency ( f = ω2 π) in the region of dispersion follows the universal response of Jonscher's equation. Enhanced resistive characteristics were observed for Ga-substituted PZT in comparison to the pure PZT, which was well ensured from the studies of electrical parameters, such as impedance and AC conductivity.

Amino acid substitutions in the thymidine kinase gene of induced acyclovir-resistant herpes simplex virus type 1

NASA Astrophysics Data System (ADS)

Hussin, Ainulkhir; Nor, Norefrina Shafinaz Md; Ibrahim, Nazlina

2013-11-01

Acyclovir (ACV) is an antiviral drug of choice in healthcare setting to treat infections caused by herpes viruses, including, but not limited to genital herpes, cold sores, shingles and chicken pox. Acyclovir resistance has emerged significantly due to extensive use and misuse of this antiviral in human, especially in immunocompromised patients. However, it remains unclear about the amino acid substitutions in thymidine (TK) gene, which specifically confer the resistance-associated mutation in herpes simplex virus. Hence, acyclovir-resistant HSV-1 was selected at high concentration (2.0 - 4.5 μg/mL), and the TK-gene was subjected to sequencing and genotypic characterization. Genotypic sequences comparison was done using HSV-1 17 (GenBank Accesion no. X14112) for resistance-associated mutation determination whereas HSV-1 KOS, HSV-1 473/08 and HSV clinical isolates sequences were used for polymorphism-associated mutation. The result showed that amino acid substitutions at the non-conserved region (UKM-1: Gln34Lys, UKM-2: Arg32Ser & UKM-5: Arg32Cys) and ATP-binding site (UKM-3: Tyr53End & UKM-4: Ile54Leu) of the TK-gene. These discoveries play an important role to extend another dimension to the evolution of acyclovir-resistant HSV-1 and suggest that selection at high ACV concentration induced ACV-resistant HSV-1 evolution. These findings also expand the knowledge on the type of mutations among acyclovir-resistant HSV-1. In conclusion, HSV-1 showed multiple strategies to exhibit acyclovir resistance, including amino acid substitutions in the TK gene.

Structure and thermodynamics of uranium-containing iron garnets

NASA Astrophysics Data System (ADS)

Guo, Xiaofeng; Navrotsky, Alexandra; Kukkadapu, Ravi K.; Engelhard, Mark H.; Lanzirotti, Antonio; Newville, Matthew; Ilton, Eugene S.; Sutton, Stephen R.; Xu, Hongwu

2016-09-01

Use of crystalline garnet as a waste form phase appears to be advantageous for accommodating actinides from nuclear waste. Previous studies show that large amounts of uranium (U) and its analogues such as cerium (Ce) and thorium (Th) can be incorporated into the garnet structure. In this study, we synthesized U loaded garnet phases, Ca3UxZr2-xFe3O12 (x = 0.5-0.7), along with the endmember phase, Ca3(Zr2)SiFe3+2O12, for comparison. The oxidation states of U were determined by X-ray photoelectron and absorption spectroscopies, revealing the presence of mixed pentavalent and hexavalent uranium in the phases with x = 0.6 and 0.7. The oxidation states and coordination environments of Fe were measured using transmission 57Fe-Mössbauer spectroscopy, which shows that all iron is tetrahedrally coordinated Fe3+. U substitution had a significant effect on local environments, the extent of U substitution within this range had a minimal effect on the structure, and unlike in the x = 0 sample, Fe exists in two different environments in the substituted garnets. The enthalpies of formation of garnet phases from constituent oxides and elements were first time determined by high temperature oxide melt solution calorimetry. The results indicate that these substituted garnets are thermodynamically stable under reducing conditions. Our structural and thermodynamic analysis further provides explanation for the formation of natural uranium garnet, elbrusite-(Zr), and supports the potential use of Ca3UxZr2-xFe3O12 as viable waste form phases for U and other actinides.

Effect of field-of-view size on gray values derived from cone-beam computed tomography compared with the Hounsfield unit values from multidetector computed tomography scans.

PubMed

Shokri, Abbas; Ramezani, Leila; Bidgoli, Mohsen; Akbarzadeh, Mahdi; Ghazikhanlu-Sani, Karim; Fallahi-Sichani, Hamed

2018-03-01

This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol. In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes ( P <.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.

Latin American Clinical Epidemiology Network Series - Paper 8: Ticagrelor was cost-effective vs. clopidogrel in acute coronary syndrome in Chile.

PubMed

De la Puente, Catherine; Vallejos, Carlos; Bustos, Luis; Zaror, Carlos; Velasquez, Monica; Lanas, Fernando

2017-06-01

To evaluate the incremental cost-effectiveness ratio (ICER) of the use of ticagrelor as a substitute for clopidogrel for secondary prevention of acute coronary syndrome in Chile. Cost-effectiveness analysis based on a Markov model: Safety and effectiveness data of ticagrelor were obtained from a systematic review of the literature. Costs are expressed in Chilean pesos (CLP) as of 2013. The evaluation was conducted from the payer standpoint. A probabilistic sensitivity analysis comprising discount rates and national cost variability was done. A budget impact analysis estimated for 2015 was conducted to calculate the total cost for both treatments. The ICER with a discount rate of 6% for ticagrelor vs. clopidogrel was CLP 4,893,126 per quality-adjusted life-year (QALY) gained (=9,689 US$). In the budget impact analysis for the baseline scenario, considering 100% of treatment, coverage, and adherence, ticagrelor represented an additional cost of CLP 5,233,854,272, for 979 QALYs gained compared with clopidogrel. Ticagrelor is cost-effective in comparison with clopidogrel for the secondary prevention of acute coronary syndrome. These findings are similar to those reported in other international cost-effectiveness studies. Copyright © 2016 Elsevier Inc. All rights reserved.

OEDIPE: a new graphical user interface for fast construction of numerical phantoms and MCNP calculations.

PubMed

Franck, D; de Carlan, L; Pierrat, N; Broggio, D; Lamart, S

2007-01-01

Although great efforts have been made to improve the physical phantoms used to calibrate in vivo measurement systems, these phantoms represent a single average counting geometry and usually contain a uniform distribution of the radionuclide over the tissue substitute. As a matter of fact, significant corrections must be made to phantom-based calibration factors in order to obtain absolute calibration efficiencies applicable to a given individual. The importance of these corrections is particularly crucial when considering in vivo measurements of low energy photons emitted by radionuclides deposited in the lung such as actinides. Thus, it was desirable to develop a method for calibrating in vivo measurement systems that is more sensitive to these types of variability. Previous works have demonstrated the possibility of such a calibration using the Monte Carlo technique. Our research programme extended such investigations to the reconstruction of numerical anthropomorphic phantoms based on personal physiological data obtained by computed tomography. New procedures based on a new graphical user interface (GUI) for development of computational phantoms for Monte Carlo calculations and data analysis are being developed to take advantage of recent progress in image-processing codes. This paper presents the principal features of this new GUI. Results of calculations and comparison with experimental data are also presented and discussed in this work.

A Tradeoff Drives the Evolution of Reduced Metal Resistance in Natural Populations of Yeast

PubMed Central

Chang, Shang-Lin; Leu, Jun-Yi

2011-01-01

Various types of genetic modification and selective forces have been implicated in the process of adaptation to novel or adverse environments. However, the underlying molecular mechanisms are not well understood in most natural populations. Here we report that a set of yeast strains collected from Evolution Canyon (EC), Israel, exhibit an extremely high tolerance to the heavy metal cadmium. We found that cadmium resistance is primarily caused by an enhanced function of a metal efflux pump, PCA1. Molecular analyses demonstrate that this enhancement can be largely attributed to mutations in the promoter sequence, while mutations in the coding region have a minor effect. Reconstruction experiments show that three single nucleotide substitutions in the PCA1 promoter quantitatively increase its activity and thus enhance the cells' cadmium resistance. Comparison among different yeast species shows that the critical nucleotides found in EC strains are conserved and functionally important for cadmium resistance in other species, suggesting that they represent an ancestral type. However, these nucleotides had diverged in most Saccharomyces cerevisiae populations, which gave cells growth advantages under conditions where cadmium is low or absent. Our results provide a rare example of a selective sweep in yeast populations driven by a tradeoff in metal resistance. PMID:21483812

An investigation into the effectiveness of smartphone experiments on students’ conceptual knowledge about acceleration

NASA Astrophysics Data System (ADS)

Mazzella, Alessandra; Testa, Italo

2016-09-01

This study is a first attempt to investigate effectiveness of smartphone-based activities on students’ conceptual understanding of acceleration. 143 secondary school students (15-16 years old) were involved in two types of activities: smartphone- and non-smartphone activities. The latter consisted in data logging and ‘cookbook’ activities. For the sake of comparison, all activities featured the same phenomena, i.e., the motion on an inclined plane and pendulum oscillations. A pre-post design was adopted, using open questionnaires as probes. Results show only weak statistical differences between the smartphone and non-smartphone groups. Students who followed smartphone activities were more able to design an experiment to measure acceleration and to correctly describe acceleration in a free fall motion. However, students of both groups had many difficulties in drawing acceleration vector along the trajectory of the studied motion. Results suggest that smartphone-based activities may be effective substitutes of traditional experimental settings and represent a valuable aid for teachers who want to implement laboratory activities at secondary school level. However, to achieve a deeper conceptual understanding of acceleration, some issues need to be addressed: what is the reference system of the built-in smartphone sensor; relationships between smartphone acceleration graphs and experimental setup; vector representation of the measured acceleration.

Comparison of Doppler and oscillometric ankle blood pressure measurement in patients with angiographically documented lower extremity arterial occlusive disease.

PubMed

Nukumizu, Yoshihito; Matsushita, Masahiro; Sakurai, Tsunehisa; Kobayashi, Masayoshi; Nishikimi, Naomichi; Komori, Kimihiro

2007-01-01

To assess the reliability of the oscillometric method in patients with peripheral vascular disease, ankle blood pressure measurement by Doppler and oscillometry was compared. This study represents a prospective, non-blinded examination of pressure measurements in 168 patients. Twenty-two patients were included who had abdominal aortic aneurysms (AAA) and 146 had peripheral arterial occlusive disease (PAOD). Patients with PAOD were divided into 2 groups according to angiography results: a crural artery occlusion group (CAO, n = 32), and a no crural artery occlusion group (NCAO, n = 114). All subjects underwent pressure measurement by both Doppler and oscillometry. The correlation coefficient was 0.928 in AAA patients and 0.922 in PAOD patients. In CAO patients, there were significantly fewer patients whose oscillometric pressure was equivalent to the Doppler pressure (DP), as compared to NCAO patients, because the oscillometric pressure (OP) was 10% higher than DP in 44% of CAO patients. A high correlation exists between Doppler and oscillometric ankle pressure measurements irrespective of the type of vascular disease. However, the oscillometric method could not be substituted for the Doppler method completely, because there were several patients whose OP was greater than DP especially in those with crural artery occlusive disease.

Comparison of nanoparticular hydroxyapatite pastes of different particle content and size in a novel scapula defect model

PubMed Central

Hruschka, Veronika; Tangl, Stefan; Ryabenkova, Yulia; Heimel, Patrick; Barnewitz, Dirk; Möbus, Günter; Keibl, Claudia; Ferguson, James; Quadros, Paulo; Miller, Cheryl; Goodchild, Rebecca; Austin, Wayne; Redl, Heinz; Nau, Thomas

2017-01-01

Nanocrystalline hydroxyapatite (HA) has good biocompatibility and the potential to support bone formation. It represents a promising alternative to autologous bone grafting, which is considered the current gold standard for the treatment of low weight bearing bone defects. The purpose of this study was to compare three bone substitute pastes of different HA content and particle size with autologous bone and empty defects, at two time points (6 and 12 months) in an ovine scapula drillhole model using micro-CT, histology and histomorphometry evaluation. The nHA-LC (38% HA content) paste supported bone formation with a high defect bridging-rate. Compared to nHA-LC, Ostim® (35% HA content) showed less and smaller particle agglomerates but also a reduced defect bridging-rate due to its fast degradation The highly concentrated nHA-HC paste (48% HA content) formed oversized particle agglomerates which supported the defect bridging but left little space for bone formation in the defect site. Interestingly, the gold standard treatment of the defect site with autologous bone tissue did not improve bone formation or defect bridging compared to the empty control. We concluded that the material resorption and bone formation was highly impacted by the particle-specific agglomeration behaviour in this study. PMID:28233833

Environmental and water sustainability of milk production in Northeast Spain.

PubMed

Noya, I; González-García, S; Berzosa, J; Baucells, F; Feijoo, G; Moreira, M T

2018-03-01

This study focuses on the assessment of the environmental profile of a milk farm, representative of the dairy sector in Northeast Spain, from a cradle-to-gate perspective. The Life Cycle Assessment (LCA) principles established by ISO standards together with the carbon footprint guidelines proposed by International Dairy Federation (IDF) were followed. The environmental results showed two critical contributing factors: the production of the livestock feed (e.g., alfalfa) and the on-farm emissions from farming activities, with contributions higher than 50% in most impact categories. A comparison with other LCA studies was carried out, which confirmed the consistency of these results with the values reported in the literature for dairy systems from several countries. Additionally, the Water Footprint (WF) values were also estimated according to the Water Footprint Network (WFN) methodology to reveal that feed and fodder production also had a predominant influence on the global WF impacts, with contributions of 99%. Green WF was responsible for remarkable environmental burdens (around 88%) due to the impacts associated with the cultivation stage. Finally, the substitution of alfalfa by other alternative protein sources in animal diets were also proposed and analysed due to its relevance as one of the main contributors of livestock feed. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Aromatic Fluorine Substitution on Protonated Neurotransmitters: The Case of 2-Phenylethylamine.

PubMed

Schütz, Markus; Bouchet, Aude; Chiavarino, Barbara; Crestoni, Maria Elisa; Fornarini, Simonetta; Dopfer, Otto

2016-06-06

Fluorination of pharmaceutical compounds is a common tool to modulate their physiochemical properties. We determine the effects of site-specific aromatic fluorine substitution on the geometric, energetic, vibrational, and electronic properties of the protonated neurotransmitter 2-phenylethylamine (xF-H(+) PEA, x=ortho, meta, para) by infrared multiphoton photodissociation (IRMPD) in the fingerprint range (600-1750 cm(-1) ) and quantum chemical calculations at the B3LYP-D3/aug-cc-pVTZ level. The IRMPD spectra of all ions are assigned to their folded gauche conformers stabilized by intramolecular NH(+) ⋅⋅⋅π hydrogen bonds (H-bonds) between the protonated amino group and the aromatic ring. H→F substitution reduces the symmetry and allows for additional NH(+) ⋅⋅⋅F interactions in oF-H(+) PEA, leading to three distinct gauche conformers. In comparison to oF-H(+) PEA, the fluorination effects on the energy landscape (energy ordering and isomerization barriers) in pF-H(+) PEA and mF-H(+) PEA with one and two gauche conformers are less pronounced. The strengths of the intramolecular NH(+) ⋅⋅⋅F and NH(+) ⋅⋅⋅π bonds are analyzed by the noncovalent interaction (NCI) method. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of the x-ray attenuation properties of breast calcifications, aluminium, hydroxyapatite and calcium oxalate.

PubMed

Warren, L M; Mackenzie, A; Dance, D R; Young, K C

2013-04-07

Aluminium is often used as a substitute material for calcifications in phantom measurements in mammography. Additionally, calcium oxalate, hydroxyapatite and aluminium are used in simulation studies. This assumes that these materials have similar attenuation properties to calcification, and this assumption is examined in this work. Sliced mastectomy samples containing calcification were imaged at ×5 magnification using a digital specimen cabinet. Images of the individual calcifications were extracted, and the diameter and contrast of each calculated. The thicknesses of aluminium required to achieve the same contrast as each calcification when imaged under the same conditions were calculated using measurements of the contrast of aluminium foils. As hydroxyapatite and calcium oxalate are also used to simulate calcifications, the equivalent aluminium thicknesses of these materials were also calculated using tabulated attenuation coefficients. On average the equivalent aluminium thickness was 0.85 times the calcification diameter. For calcium oxalate and hydroxyapatite, the equivalent aluminium thicknesses were 1.01 and 2.19 times the thickness of these materials respectively. Aluminium and calcium oxalate are suitable substitute materials for calcifications. Hydroxyapatite is much more attenuating than the calcifications and aluminium. Using solid hydroxyapatite as a substitute for calcification of the same size would lead to excessive contrast in the mammographic image.

Nicotine absorption from electronic cigarette use: comparison between first and new-generation devices.

PubMed

Farsalinos, Konstantinos E; Spyrou, Alketa; Tsimopoulou, Kalliroi; Stefopoulos, Christos; Romagna, Giorgio; Voudris, Vassilis

2014-02-26

A wide range of electronic cigarette (EC) devices, from small cigarette-like (first-generation) to new-generation high-capacity batteries with electronic circuits that provide high energy to a refillable atomizer, are available for smokers to substitute smoking. Nicotine delivery to the bloodstream is important in determining the addictiveness of ECs, but also their efficacy as smoking substitutes. In this study, plasma nicotine levels were measured in experienced users using a first- vs. new-generation EC device for 1 hour with an 18 mg/ml nicotine-containing liquid. Plasma nicotine levels were higher by 35-72% when using the new- compared to the first-generation device. Compared to smoking one tobacco cigarette, the EC devices and liquid used in this study delivered one-third to one-fourth the amount of nicotine after 5 minutes of use. New-generation EC devices were more efficient in nicotine delivery, but still delivered nicotine much slower compared to tobacco cigarettes. The use of 18 mg/ml nicotine-concentration liquid probably compromises ECs' effectiveness as smoking substitutes; this study supports the need for higher levels of nicotine-containing liquids (approximately 50 mg/ml) in order to deliver nicotine more effectively and approach the nicotine-delivery profile of tobacco cigarettes.

The origin of the variola virus.

PubMed

Babkin, Igor V; Babkina, Irina N

2015-03-10

The question of the origin of smallpox, one of the major menaces to humankind, is a constant concern for the scientific community. Smallpox is caused by the agent referred to as the variola virus (VARV), which belongs to the genus Orthopoxvirus. In the last century, smallpox was declared eradicated from the human community; however, the mechanisms responsible for the emergence of new dangerous pathogens have yet to be unraveled. Evolutionary analyses of the molecular biological genomic data of various orthopoxviruses, involving a wide range of epidemiological and historical information about smallpox, have made it possible to date the emergence of VARV. Comparisons of the VARV genome to the genomes of the most closely related orthopoxviruses and the examination of the distribution their natural hosts' ranges suggest that VARV emerged 3000 to 4000 years ago in the east of the African continent. The VARV evolution rate has been estimated to be approximately 2 × 10-6 substitutions/site/year for the central conserved genomic region and 4 × 10-6 substitutions/site/year for the synonymous substitutions in the genome. Presumably, the introduction of camels to Africa and the concurrent changes to the climate were the particular factors that triggered the divergent evolution of a cowpox-like ancestral virus and thereby led to the emergence of VARV.

Plant parts substitution based approach as a viable conservation strategy for medicinal plants: A case study of Premna latifolia Roxb.

PubMed

Jena, Ashish Kumar; Karan, Maninder; Vasisht, Karan

Rapid population growth and catastrophic harvesting methods of wild medicinal plants especially trees, result in the exploitation of natural sources and its management is the need of the hour. Dashamoolarishta is an amalgam of roots of ten plants of a popular Ayurvedic FDC formulation consisting of the root of Premna latifolia Roxb. as one of its ingredients. Presently, their populations like many other trees are under threat due to extensive use of the roots by the herbal drug industry. With an aim to conserve the biodiversity, a systematic study based on a rational approach by substituting root/root bark with alternative and renewable parts was conducted. The fingerprint profile together with anti-inflammatory and analgesic effect of different parts of the plant was established for comparison. The results based on chemical and biological study indicated close similarity between the roots and the leaves and suggest the possible use of latter over root/root bark. The study proposes that the substitution of the root with alternate renewable parts of the same plant shall form the best strategy towards conservation of the trees like P. latifolia. Copyright © 2016 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

A Comparison of Two Single-Stranded DNA Binding Models by Mutational Analysis of APOBEC3G

PubMed Central

Shindo, Keisuke; Li, Ming; Gross, Phillip J.; Brown, William L.; Harjes, Elena; Lu, Yongjian; Matsuo, Hiroshi; Harris, Reuben S.

2012-01-01

APOBEC3G is the best known of several DNA cytosine deaminases that function to inhibit the replication of parasitic genetic elements including the lentivirus HIV. Several high-resolution structures of the APOBEC3G catalytic domain have been generated, but none reveal how this enzyme binds to substrate single-stranded DNA. Here, we constructed a panel of APOBEC3G amino acid substitution mutants and performed a series of biochemical, genetic, and structural assays to distinguish between “Brim” and “Kink” models for single-strand DNA binding. Each model predicts distinct sets of interactions between surface arginines and negatively charged phosphates in the DNA backbone. Concordant with both models, changing the conserved arginine at position 313 to glutamate abolished both catalytic and restriction activities. In support of the Brim model, arginine to glutamate substitutions at positions 213, 215, and 320 also compromised these APOBEC3G activities. Arginine to glutamate substitutions at Kink model residues 374 and 376 had smaller effects. These observations were supported by A3G catalytic domain-ssDNA chemical shift perturbation experiments. The overall data set is most consistent with the Brim model for single-stranded DNA binding by APOBEC3G. PMID:24832226

Moisture sorption curves of fruit and nut cereal bar prepared with sugar and sugar substitutes.

PubMed

Pallavi, Byrappa Vasu; Chetana, Ramakrishna; Ravi, Ramaswamy; Reddy, Sunkireddy Yella

2015-03-01

Low sugar, low fat, dry fruit and nut cereal bars without sugar were prepared using cereals, nuts, and sugar substitutes. The sorption characteristics of the bars prepared with sugar substitutes in comparison with that of sugar were studied by keeping the bars at water activity (aw) from 0.1 to 0.9. The sorption isotherms of low sugar bars were practically identical below aw of 0.5 but above aw of 0.5, a clear differentiation in the isotherms could be observed compared to that of sugar counterpart. A sharp increase in moisture content was observed in the bars prepared with alternative sweeteners, above aw 0.6, whereas a gradual increase in aw was observed in the case of bar prepared with sugar. The ERH (Equilibrium relative humidity) value for bar with sugar was 50 %, and for bars prepared with alternative sweeteners, it was about 60 %. Low sugar cereal bar prepared with sorbitol + maltitol (SM) syrup scored higher sensory quality compared to other product prepared with sorbitol + nutriose (SN) as the former retained softness and chewiness on storage. Thus, it was observed that bars with alternative sweeteners will be more stable as their ERH is closer to normal ambient conditions compared to that prepared with sugar.

Improvement of thermostability and halostability of β-1,3-1,4-glucanase by substituting hydrophobic residue for Lys48.

PubMed

Lee, Jong Min; Moon, Soo Young; Kim, Yu-Ri; Kim, Kang Woong; Lee, Bong-Joo; Kong, In-Soo

2017-01-01

The aim of this study was to improve the stability of β-1,3-1,4-glucanase by substituting hydrophobic residue for specific amino acid. The results indicated that the catalytic efficiency, thermostability and halostability were enhanced simultaneously by replacement of Lys48 with Ala (K48A) or Leu (K48L). Comparison of kinetic parameters revealed that catalytic efficiency of mutants is enhanced as a result of the increase in substrate affinity. A great improvement in thermostability and halostability was observed. The half-lives of mutants significantly increased (up to ∼7-fold) at 60-70°C. Moreover, relative enzymatic activities of mutants were observed more than 80% even in the presence of 30% NaCl, and half-lives were increased to 3-fold that of wild-type. Based on above results, when applied to ionic liquid, mutants were more active and stable compared to wild-type. These were the results from improvement of protein functions by the substitution of hydrophobic single residue in adjacent with forming carbohydrate binding cavity. Therefore, this report could be helpful for improvement of the enzyme property and for biotechnological application as well. Copyright © 2016 Elsevier B.V. All rights reserved.

40 CFR 419.42 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... exceed 15 mg/l oil and grease and 110 mg/l total organic carbon (TOC) based upon an analysis of any... 110 mg/l TOC is not commingled or treated with any other type of wastewater, the quantity of... exceeds 1,000 mg/l (1,000 ppm), the permitting authority may substitute TOC as a parameter in lieu of COD...

40 CFR 419.32 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... discharged if it does not exceed 15 mg/l oil and grease and 110 mg/l total organic carbon (TOC) based upon an... and grease or 110 mg/l TOC is not commingled or treated with any other type of wastewater, the... effluent exceeds 1,000 mg/l (1,000 ppm), the permitting authority may substitute TOC as a parameter in lieu...

40 CFR 419.52 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... mg/l total organic carbon (TOC) based upon an analysis of any single grab or composite sample. (2) If... contaminated runoff which exceeds 15 mg/l oil and grease or 110 mg/l TOC is not commingled or treated with any... substitute TOC as a parameter in lieu of COD. A TOC effluent limitation shall be based on effluent data from...

Genome build information is an essential part of genomic track files.

PubMed

Kanduri, Chakravarthi; Domanska, Diana; Hovig, Eivind; Sandve, Geir Kjetil

2017-09-14

Genomic locations are represented as coordinates on a specific genome build version, but the build information is frequently missing when coordinates are provided. We show that this information is essential to correctly interpret and analyse the genomic intervals contained in genomic track files. Although not a substitute for best practices, we also provide a tool to predict the genome build version of genomic track files.

InChIKey collision resistance: an experimental testing

PubMed Central

2012-01-01

InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be a nearly unique substitute for the parent InChI. However, a single InChIKey may occasionally map to two or more InChI strings (collision). The appearance of collision itself does not compromise the signature as collision-free hashing is impossible; the only viable approach is to set and keep a reasonable level of collision resistance which is sufficient for typical applications. We tested, in computational experiments, how well the real-life InChIKey collision resistance corresponds to the theoretical estimates expected by design. For this purpose, we analyzed the statistical characteristics of InChIKey for datasets of variable size in comparison to the theoretical statistical frequencies. For the relatively short second block, an exhaustive direct testing was performed. We computed and compared to theory the numbers of collisions for the stereoisomers of Spongistatin I (using the whole set of 67,108,864 isomers and its subsets). For the longer first block, we generated, using custom-made software, InChIKeys for more than 3 × 1010 chemical structures. The statistical behavior of this block was tested by comparison of experimental and theoretical frequencies for the various four-letter sequences which may appear in the first block body. From the results of our computational experiments we conclude that the observed characteristics of InChIKey collision resistance are in good agreement with theoretical expectations. PMID:23256896

InChIKey collision resistance: an experimental testing.

PubMed

Pletnev, Igor; Erin, Andrey; McNaught, Alan; Blinov, Kirill; Tchekhovskoi, Dmitrii; Heller, Steve

2012-12-20

InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be a nearly unique substitute for the parent InChI. However, a single InChIKey may occasionally map to two or more InChI strings (collision). The appearance of collision itself does not compromise the signature as collision-free hashing is impossible; the only viable approach is to set and keep a reasonable level of collision resistance which is sufficient for typical applications.We tested, in computational experiments, how well the real-life InChIKey collision resistance corresponds to the theoretical estimates expected by design. For this purpose, we analyzed the statistical characteristics of InChIKey for datasets of variable size in comparison to the theoretical statistical frequencies. For the relatively short second block, an exhaustive direct testing was performed. We computed and compared to theory the numbers of collisions for the stereoisomers of Spongistatin I (using the whole set of 67,108,864 isomers and its subsets). For the longer first block, we generated, using custom-made software, InChIKeys for more than 3 × 1010 chemical structures. The statistical behavior of this block was tested by comparison of experimental and theoretical frequencies for the various four-letter sequences which may appear in the first block body.From the results of our computational experiments we conclude that the observed characteristics of InChIKey collision resistance are in good agreement with theoretical expectations.

Synthetic Strategies for Engineering Intravenous Hemostats

PubMed Central

Chan, Leslie W.-G.; White, Nathan J.; Pun, Suzie H.

2015-01-01

While there are currently many well-established topical hemostatic agents for field administration, there are still limited tools to staunch bleeding at less accessible injury sites. Current clinical methods of restoring hemostasis after large volume blood loss include platelet and clotting factor transfusion, which have respective drawbacks of short shelf-life and risk of viral transmission. Therefore, synthetic hemostatic agents that can be delivered intravenously and encourage stable clot formation after localizing to sites of vascular injury are particularly appealing. In the past three decades, platelet substitutes have been prepared using drug delivery vehicles such as liposomes and PLGA nanoparticles that have been modified to mimic platelet properties. Additionally, structural considerations such as particle size, shape, and flexibility have been addressed in a number of reports. Since platelets are the first responders after vascular injury, platelet substitutes represent an important class of intravenous hemostats under development. More recently, materials affecting fibrin formation have been introduced to induce faster or more stable blood clot formation through fibrin crosslinking. Fibrin represents a major structural component in the final blood clot, and a fibrin-based hemostatic mechanism acting downstream of initial platelet plug formation may be a safer alternative to platelets to avoid undesired thrombotic activity. This review explores intravenous hemostats under development and strategies to optimize their clotting activity. PMID:25803791

Synthesis and Characterization of Novel Biotinylated Carboxyl-terminal Parathyroid Hormone Peptides that Specifically Crosslink to the CPTH-receptor

PubMed Central

Banerjee, Santanu; Selim, Hafez; Suliman, Gihan; Geller, Andrew I.; Jüppner, Harald; Bringhurst, F. Richard; Divieti, Paola

2006-01-01

Parathyroid hormone (PTH) regulates calcium, phosphorous and skeletal homeostasis via interaction with the G protein-coupled PTH/PTHrP receptor, which is fully activated by the amino-terminal 34 amino-acid portion of the hormone. Recent evidence points to the existence of another class of receptors for PTH that recognize the carboxyl (C)-terminal region of intact PTH(1–84) (CPTHRs) and are highly expressed by osteocytes. Here we report the synthesis and characterization of two novel bifunctional CPTH ligands that include benzoylphenylalanine (Bpa) substitutions near their amino-termini and carboxyl-terminal biotin moieties, as well as a tyrosine34 substitution to enable radioiodination. These peptides are shown to bind to CPTHRs with affinity similar to that of PTH (1–84) and to be specifically and covalently cross-linked to CPTHRs upon exposure to ultraviolet light. Crosslinking to osteocytes or osteoblastic cells generates complexes of 80kDa and 220kDa, of which the larger form represents an aggregate that can be resolved into the 80kDa. The crosslinked products can be further purified using immunoaffinity and avidin-based affinity procedures. While the molecular structure of the CPTHR(s) remains undefined, these bifunctional ligands represent powerful new tools for use in isolating and characterizing CPTHR protein(s). PMID:17028061

Optimization of fly ash and bottom ash substitution against paving block manufacture according to SNI 03-0691-1996

NASA Astrophysics Data System (ADS)

Karolina, R.; Syahrizal; Bahri, N.

2018-02-01

The waste of coal burning has a very negative impact on the environment if the waste is not managed as well as possible. The remaining waste of coal combustion consists of fly ash and bottom ash. FA and BA can be developed into substitution materials in the process of making paving blocks. The purpose of this study was to determine the quality of paving block in accordance with SK SNI 03-0691-1996 with optimization in the use of FA and BA. This study uses a 351 paving block sample size of 20x10x6 cm. Paving blocks are divided by 4 categories, namely normal paving block, paving block with FA substitution, BA substitution and combination of FA-BA with each variation 0%, 25%, 50%, 75% and 100%. Each variation amounted to 27 samples. Paving block quality measurement is done through 4 tests: absorption, compressive strength, sodium sulphate resistance and Los Angeles tests. The result of the test shows the absorption of normal paving block is 3,229%, paving block with 25% FA is 3,889%, paving block with 50% BA is 5,560% and paving block with 25% FA-BA combination is 5,794%. Compressive strength in normal paving block is 25,50 MPa, paving block with 25% FA is 25,28 MPa, paving block with 25% BA is equal to 27,61 MPa and paving block with 25% FA-BA is 26, 00 MPa. In testing of sodium sulfate resistance, almost all test specimens are eligible except for paving block with 50% FA and 75% FA. In the test of wear resistance, no specimen is eligible according to SK SNI 03-0691-1996. The comparison of the strength of the test specimen can be seen in substitution with 25% BA which reaches maximum strength.

[Genetic evolution and substitution frequency of avian influenza virus HA gene in chicken H9N2 subtype in China in the last 20 years].

PubMed

Meng, Fang; Xu, Huaiying; Zhang, Wei; Huang, Dihai; Zhang, Zaihui; Liu, Xia; Chang, Weishan; Qin, Zhuoming

2016-01-04

Low pathogenic avian influenza (LPAI) H9N2 subtype virus has been prevalent in domestic poultry in China over two decades. This study was to determine the genetic evolution trend of H9N2 avian influenza virus (AIV) under immune pressure of vaccine. H9 HA sequences of 40 isolates from the present study and 136 pandemic strains and 7 classical strains from China downloaded from GenBank, were genetically analyzed to determine evolution, molecular characteristic, and mutation frequency. Phylogenetic trees analysis suggested that H9N2 subtypes AIV could be clustered into 5 distinct lineages: G1-like, BJ94-like, Y280-like, S2-like and Americans lineages. Most H9N2 isolates in 2005-2014 belonged to S2-like sub-genotype, suggesting that this genotype was the dominate isolates in China. Further more, comparison based on the amino acid sequence showed that different lineages have their distinct characteristics, and significant accumulations of amino acid variation were also found. In addition, in comparison with reference Ck/BJ/1/1994 HA gene, average annual substitution rates of H9N2 pandemic strain nucleotide and amino acid were 5.73 x 10⁻³ and 4.25 x 10⁻³ from 1994 to 2014, respectively. Substitution rate during 2011-2014 were 6.35 x 10⁻³ and 5.32 x 10⁻³, higher than that during the period of 2006-2010 (5.22 x 10⁻³ and 3.70 x 10⁻³) and even much higher than that during the 1999-2005 (0.74 x 10⁻³ and 0.50 x 10⁻³), when the vaccines were initially applied in the field. Overall, these data indicate that the mismatch between H9N2 vaccine strains and pandemic strains drives the virus to quickly mutate.

Comparison of Cervical Spine Anatomy in Calves, Pigs and Humans.

PubMed

Sheng, Sun-Ren; Xu, Hua-Zi; Wang, Yong-Li; Zhu, Qing-An; Mao, Fang-Min; Lin, Yan; Wang, Xiang-Yang

2016-01-01

Animals are commonly used to model the human spine for in vitro and in vivo experiments. Many studies have investigated similarities and differences between animals and humans in the lumbar and thoracic vertebrae. However, a quantitative anatomic comparison of calf, pig, and human cervical spines has not been reported. To compare fundamental structural similarities and differences in vertebral bodies from the cervical spines of commonly used experimental animal models and humans. Anatomical morphometric analysis was performed on cervical vertebra specimens harvested from humans and two common large animals (i.e., calves and pigs). Multiple morphometric parameters were directly measured from cervical spine specimens of twelve pigs, twelve calves and twelve human adult cadavers. The following anatomical parameters were measured: vertebral body width (VBW), vertebral body depth (VBD), vertebral body height (VBH), spinal canal width (SCW), spinal canal depth (SCD), pedicle width (PW), pedicle depth (PD), pedicle inclination (PI), dens width (DW), dens depth (DD), total vertebral width (TVW), and total vertebral depth (TVD). The atlantoaxial (C1-2) joint in pigs is similar to that in humans and could serve as a human substitute. The pig cervical spine is highly similar to the human cervical spine, except for two large transverse processes in the anterior regions ofC4-C6. The width and depth of the calf odontoid process were larger than those in humans. VBW and VBD of calf cervical vertebrae were larger than those in humans, but the spinal canal was smaller. Calf C7 was relatively similar to human C7, thus, it may be a good substitute. Pig cervical vertebrae were more suitable human substitutions than calf cervical vertebrae, especially with respect to C1, C2, and C7. The biomechanical properties of nerve vascular anatomy and various segment functions in pig and calf cervical vertebrae must be considered when selecting an animal model for research on the spine.

Effects of substituting ytterbium for scandium on the microstructure and properties of Al-Sc and Al-Mg-Sc alloys =

NASA Astrophysics Data System (ADS)

Tuan, Nguyen Quoc

Al(Sc) alloys represent a new class of potential alloys for high performance structural applications. The excellent properties obtained from the combination of solid-solution hardening and precipitation hardening in Al-Mg-Sc alloys make these alloys very attractive to automotive, aerospace, and structural applications. However, the Sc high cost limits the applications and the addition of cheaper alloying elements that substitutes partially Sc are not only desirable but crucial. In order to reduce the cost of Sc-containing Al alloys and maintain their mechanical properties, the microstructure and mechanical properties of Al-Sc-Yb and Al-Mg-Sc-Yb alloys in comparison with Al-Sc and Al-Mg-Sc alloys were studied. The results showed the similarity of microstructure, hardness and aging behaviour of Al-0.24Sc-0.07Yb alloy in comparison with Al-0.28Sc alloy and Al-4 wt% Mg-0.3 wt% Sc alloy with Al-4 wt% Mg-0.24 wt% Sc-0.06 wt% Yb alloy. The approximately spheroidal Al3Sc and Al3(Sc,Yb) precipitates were uniformly distributed throughout the alpha-Al matrix. The precipitates remain fully coherent with alpha-Al matrix even after aging at high temperature for long time. In another aspect, the grain refinement in Al-Mg-Sc alloys with and without ultrasonic treatment at various pouring temperatures was investigated. The average grain size of Al-Mg-Sc alloy remarkably decreases by increasing the content of Mg or by adding 0.3 wt% of Sc. The pouring temperature has a strong effect on the microstructure of Al-1Mg-0.3Sc alloy. Lower pouring temperature leads to smaller grain size and more homogeneous microstructure. Ultrasonic vibration proved to be a potential grain refinement technique of Al-1Mg-0.3Sc. Significant grain refinement was obtained by applying ultrasonic treatment within the temperature range from 700 to 740 °C. The corrosion behaviour of Al-Sc, Al-Sc-Yb, Al-Mg, Al-Mg-Sc and Al-Mg-Sc-Yb alloys in 3.5 wt% NaCl solution was investigated by immersion and potentiodynamic polarisation analysis in order to understand the effect of Sc, Yb, and heat treatment on the localized corrosion and electrochemical behaviour. The addition of Yb decreases the corrosion tendency and improves the pitting corrosion resistance of Al-Sc alloy. The addition of Sc and Yb to Al-4Mg alloy decrease the susceptibility to corrosion of the heat treated alloys.

Detector absorptivity measuring method and apparatus

NASA Technical Reports Server (NTRS)

Sheets, R. E. (Inventor)

1976-01-01

A method and apparatus for measuring the absorptivity of a radiation detector by making the detector an integral part of a cavity radiometer are described. By substituting the detector for the surface of the cavity upon which the radiation first impinges a comparison is made between the quantity of radiation incident upon the detector and the quantity reflected from the detector. The difference between the two is a measurement of the amount of radiation absorbed by the detector.

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

PubMed Central

Moreno-Marrodan, Carmen; Liguori, Francesca

2017-01-01

The catalytic partial hydrogenation of substituted alkynes to alkenes is a process of high importance in the manufacture of several market chemicals. The present paper shortly reviews the heterogeneous catalytic systems engineered for this reaction under continuous flow and in the liquid phase. The main contributions appeared in the literature from 1997 up to August 2016 are discussed in terms of reactor design. A comparison with batch and industrial processes is provided whenever possible. PMID:28503209

Gold for the generation and control of fluxional barbaralyl cations.

PubMed

McGonigal, Paul R; de León, Claudia; Wang, Yahui; Homs, Anna; Solorio-Alvarado, César R; Echavarren, Antonio M

2012-12-21

The frog prince with his two identities pales in comparison with the shape-shifting barbaralyl cation, which exists as a mixture of 181,400 degenerate forms. Gold-catalyzed cycloisomerizations of 7-alkynyl cyclohepta-1,3,5-trienes were found to proceed via fluxional barbaralyl intermediates. The evolution of the intermediates into 1- or 2-substituted indenes could be controlled by the choice of gold complex. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Survivorship comparison of all-polyethylene and metal-backed tibial components in cruciate-substituting total knee arthroplasty--Chinese experience.

PubMed

Shen, Bin; Yang, Jing; Zhou, Zongke; Kang, Pengde; Wang, Liao; Pei, Fuxing

2009-10-01

Considering its cost saving, the all-polyethylene tibial component is of potential interest in developing countries like China. But to our knowledge, a survivorship comparison of all-polyethylene and metal-backed tibial components in posterior cruciate ligament-substituting total knee arthroplasty (PS-TKA) has not been studied in China previously. Using survivorship analysis, we have studied the midterm outcome of 34 cemented PS-TKA using an all-polyethylene tibial component and of 34 cemented PS-TKA using a metal-backed tibial component which has an identical articular surface with all-polyethylene tibial components. All operations were performed by the same group of surgeons; 58 patients underwent a unilateral operation and five patients a bilateral operation. These patients had a mean follow-up of 5.9 years (range: 5-7 years); three patients were lost to follow-up and one was revised for infection. No significant difference between the two groups was reported regarding HSS scores, ROM, clinical and radiographic parameters measured and survival rates. Although the Asian lifestyle includes more squatting and bending of the knee, the results of this series of TKA using all-polyethylene tibial components in Chinese people are comparable to the satisfactory results of other reported all-polyethylene series whose patients are mainly Western people. Considering its cost saving and excellent clinical result, the all-polyethylene tibial component is of potential interest in developing countries.

Evaluation of statistical treatments of left-censored environmental data using coincident uncensored data sets. II. Group comparisons

USGS Publications Warehouse

Antweiler, Ronald C.

2015-01-01

The main classes of statistical treatments that have been used to determine if two groups of censored environmental data arise from the same distribution are substitution methods, maximum likelihood (MLE) techniques, and nonparametric methods. These treatments along with using all instrument-generated data (IN), even those less than the detection limit, were evaluated by examining 550 data sets in which the true values of the censored data were known, and therefore “true” probabilities could be calculated and used as a yardstick for comparison. It was found that technique “quality” was strongly dependent on the degree of censoring present in the groups. For low degrees of censoring (<25% in each group), the Generalized Wilcoxon (GW) technique and substitution of √2/2 times the detection limit gave overall the best results. For moderate degrees of censoring, MLE worked best, but only if the distribution could be estimated to be normal or log-normal prior to its application; otherwise, GW was a suitable alternative. For higher degrees of censoring (each group >40% censoring), no technique provided reliable estimates of the true probability. Group size did not appear to influence the quality of the result, and no technique appeared to become better or worse than other techniques relative to group size. Finally, IN appeared to do very well relative to the other techniques regardless of censoring or group size.

A new firefly luciferase with bimodal spectrum: identification of structural determinants of spectral pH-sensitivity in firefly luciferases.

PubMed

Viviani, Vadim R; Oehlmeyer, T L; Arnoldi, F G C; Brochetto-Braga, M R

2005-01-01

Fireflies emit flashes in the green-yellow region of the spectrum for the purpose of sexual attraction. The bioluminescence color is determined by the luciferases. It is well known that the in vitro bioluminescence color of firefly luciferases can be shifted toward the red by lower pH and higher temperature; for this reason they are classified as pH-sensitive luciferases. However, the mechanism and structural origin of pH sensitivity in fireflies remains unknown. Here we report the cloning of a new luciferase from the Brazilian twilight active firefly Macrolampis sp2, which displays an unusual bimodal spectrum. The recombinant luciferase displays a sensitive spectrum with the peak at 569 nm and a shoulder in the red region. Comparison of the bioluminescence spectra of Macrolampis, Photinus and Cratomorphus firefly luciferases shows that the distinct colors are determined by the ratio between green and red emitters under luciferase influence. Comparison of Macrolampis luciferase with the highly similar North American Photinus pyralis luciferase (91%) showed few substitutions potentially involved with the higher spectral sensitivity in Macrolampis luciferase. Site-directed mutagenesis showed that the natural substitution E354N determines the appearance of the shoulder in the red region of Macrolampis luciferase bioluminescence spectrum, helping to identify important interactions and residues involved in the pH-sensing mechanism in firefly luciferases.

DNA barcoding detects contamination and substitution in North American herbal products

PubMed Central

2013-01-01

Background Herbal products available to consumers in the marketplace may be contaminated or substituted with alternative plant species and fillers that are not listed on the labels. According to the World Health Organization, the adulteration of herbal products is a threat to consumer safety. Our research aimed to investigate herbal product integrity and authenticity with the goal of protecting consumers from health risks associated with product substitution and contamination. Methods We used DNA barcoding to conduct a blind test of the authenticity for (i) 44 herbal products representing 12 companies and 30 different species of herbs, and (ii) 50 leaf samples collected from 42 herbal species. Our laboratory also assembled the first standard reference material (SRM) herbal barcode library from 100 herbal species of known provenance that were used to identify the unknown herbal products and leaf samples. Results We recovered DNA barcodes from most herbal products (91%) and all leaf samples (100%), with 95% species resolution using a tiered approach (rbcL + ITS2). Most (59%) of the products tested contained DNA barcodes from plant species not listed on the labels. Although we were able to authenticate almost half (48%) of the products, one-third of these also contained contaminants and or fillers not listed on the label. Product substitution occurred in 30/44 of the products tested and only 2/12 companies had products without any substitution, contamination or fillers. Some of the contaminants we found pose serious health risks to consumers. Conclusions Most of the herbal products tested were of poor quality, including considerable product substitution, contamination and use of fillers. These activities dilute the effectiveness of otherwise useful remedies, lowering the perceived value of all related products because of a lack of consumer confidence in them. We suggest that the herbal industry should embrace DNA barcoding for authenticating herbal products through testing of raw materials used in manufacturing products. The use of an SRM DNA herbal barcode library for testing bulk materials could provide a method for 'best practices? in the manufacturing of herbal products. This would provide consumers with safe, high quality herbal products. PMID:24120035

The role of evidence and the expert in contemporary processes of governance: the case of opioid substitution treatment policy in England.

PubMed

Duke, Karen; Thom, Betsy

2014-09-01

This paper is based on research examining stakeholder involvement in substitution treatment policy which was undertaken as part of the EU funded FP7 ALICE-RAP (Addictions and Lifestyles in Contemporary Europe - Reframing Addictions Project). In England, the research coincided with a policy shift towards a recovery orientated drug treatment framework and a heated debate surrounding the role of substitute prescribing. The study aimed to explore the various influences on the development of the new 'recovery' policy from the perspectives of the key stakeholders involved. The paper is based on documentary analyses and key informant interviews with a range of stakeholders, including representatives of user organisations, treatment providers, civil servants, and members of expert committees. Drawing on the theoretical insights offered by Backstrand's 'civic science' framework, the changing role of evidence and the position of experts in the processes of drugs policy governance are explored. 'Evidence' was used to problematise the issue of substitution treatment and employed to legitimise, justify and construct arguments around the possible directions of policy and practice. Conflicting beliefs about drug treatment and about motivation for policy change emerge in the argumentation, illustrating tensions in the governance of drug treatment and the power differentials separating different groups of stakeholders. Their role in the production of evidence also illustrates issues of power regarding the definition and development of 'usable knowledge'. There were various attempts at greater representation of different forms of evidence and participation by a wider group of stakeholders in the debates surrounding substitution treatment. However, key national and international experts and the appointment of specialist committees continued to play dominant roles in building consensus and translating scientific evidence into policy discourse. Substitution treatment policy has witnessed a challenge to the dominance of 'scientific evidence' within policy decision making, but in the absence of alternative evidence with an acceptable credibility and legitimacy base, traditional notions of what constitutes evidence based policy persist and there is a continuing lack of recognition of 'civic science'. Copyright © 2014 Elsevier B.V. All rights reserved.

Bromomethylthioindole Inspired Carbazole Hybrids as Promising Class of Anti-MRSA Agents.

PubMed

Cheng, Chia-Yi; Chang, Chun-Ping; Lauderdale, Tsai-Ling Yang; Yu, Guann-Yi; Lee, Jinq-Chyi; Jhang, Yi-Wun; Wu, Chien-Huang; Ke, Yi-Yu; Sadani, Amit A; Yeh, Ching-Fang; Huang, I-Wen; Kuo, Yi-Ping; Tsai, De-Jiun; Yeh, Teng-Kuang; Tseng, Chen-Tso; Song, Jen-Shin; Liu, Yu-Wei; Tsou, Lun K; Shia, Kak-Shan

2016-12-08

Series of N -substituted carbazole analogues bearing an indole ring were synthesized as anti-methicillin-resistant Staphylococcus aureus (MRSA) agents from a molecular hybridization approach. The representative compound 19 showed an MIC = 1 μg/mL against a panel of MRSA clinical isolates as it possessed comparable in vitro activities to that of vancomycin. Moreover, compound 19 also exhibited MIC = 1 μg/mL activities against a recent identified Z172 MRSA strain (vancomycin-intermediate and daptomycin-nonsusceptible phenotype) and the vancomycin-resistant Enterococcus faecalis (VRE) strain. In a mouse model with lethal infection of MRSA (4N216), a 75% survival rate was observed after a single dose of compound 19 was intravenously administered at 20 mg/kg. In light of their equipotent activities against different MRSA isolates and VRE strain, the data underscore the importance of designed hybrid series for the development of new N -substituted carbazoles as potential anti-MRSA agents.

Effect of substitutional defects on Kambersky damping in L1{sub 0} magnetic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qu, T.; Victora, R. H., E-mail: victora@umn.edu; Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455

2015-02-16

Kambersky damping, representing the loss of magnetic energy from the electrons to the lattice through the spin orbit interaction, is calculated for L1{sub 0} FePt, FePd, CoPt, and CoPd alloys versus chemical degree of order. When more substitutional defects exist in the alloys, damping is predicted to increase due to the increase of the spin-flip channels allowed by the broken symmetry. It is demonstrated that this corresponds to an enhanced density of states (DOS) at the Fermi level, owing to the rounding of the DOS with loss of long-range order. Both the damping and the DOS of the Co-based alloymore » are found to be less affected by the disorder. Pd-based alloys are predicted to have lower damping than Pt-based alloys, making them more suitable for high density spintronic applications.« less

Preparation and characterization of a novel skin substitute.

PubMed

Castagnoli, Carlotta; Fumagalli, Mara; Alotto, Daniela; Cambieri, Irene; Casarin, Stefania; Ostorero, Alessia; Casimiri, Raffaella; Germano, Patrizia; Pezzuto, Carla; Stella, Maurizio

2010-01-01

Autologous epidermal cell cultures (CEA) represent a possibility to treat extensive burn lesions, since they allow a significative surface expansion which cannot be achieved with other surgical techniques based on autologous grafting. Moreover currently available CEA preparations are difficult to handle and their take rate is unpredictable. This study aimed at producing and evaluating a new cutaneous biosubstitute made up of alloplastic acellular glycerolized dermis (AAGD) and CEA to overcome these difficulties. A procedure that maintained an intact basement membrane was developed, so as to promote adhesion and growth of CEA on AAGD. Keratinocytes were seeded onto AAGD and cultured up to 21 days. Viability tests and immunohistochemical analysis with specific markers were carried out at 7, 14, and 21 days, to evaluate keratinocyte adhesion, growth, and maturation. Our results support the hypothesis that this newly formed skin substitute could allow its permanent engraftment in clinical application.

[Hypothyreodism. From the latent functional disorder up to coma].

PubMed

Hintze, G; Derwahl, M

2010-05-01

An autoimmune thyroiditis represents the main reason of hypothyroidism, defined as a lack of thyroid hormone. This autoimmune process results in destruction of functioning thyroid follicles. While subclinical or latent hypothyroidism is defined on the basis of laboratory values (an elevation of TSH with normal peripheral hormone levels), the typical signs and symptoms are associated with hypothyroidism. In about 80% of cases antibodies against thyroid peroxidase can be measured, but only in about 40-50% of cases antibodies against thyroglobulin are detectable. If hypothyrodism has been diagnosed, substitution with levothyroxine should be initiated, with the therapeutic goal to decrease TSH level to the lower normal range. In cases of subclinical hypothyroidism, levothyroxine medication should be started in patients with a high TSH value, positive antibodies and/or the typical ultrasound of autoimmune thyroiditis. However, substitution with levothyroxine in any case of elevated TSH values should be avoided.

Autism, intellectual disability, and a challenge to our understanding of proxy consent.

PubMed

Graber, Abraham

2017-06-01

This paper focuses on a hypothetical case that represents an intervention request familiar to those who work with individuals with intellectual disability. Stacy has autism and moderate intellectual disability. Her parents have requested treatment for her hand flapping. Stacy is not competent to make her own treatment decisions; proxy consent is required. There are three primary justifications for proxy consent: the right to an open future, substituted judgment, and the best interest standard. The right to an open future justifies proxy consent on the assumption of future autonomy whereas substituted judgment justifies proxy consent via reference to past autonomy. Neither applies. Stacy has not been, nor will she be, competent to make her own treatment decisions. The best interest standard justifies proxy consent on the grounds of beneficence. It is unlikely that hand flapping harms Stacy. None of the three primary means of justifying proxy consent apply to Stacy's case.

Evolution of quantum criticality in CeNi(9-x)Cu(x)Ge(4).

PubMed

Peyker, L; Gold, C; Scheidt, E-W; Scherer, W; Donath, J G; Gegenwart, P; Mayr, F; Unruh, T; Eyert, V; Bauer, E; Michor, H

2009-06-10

Crystal structure, specific heat, thermal expansion, magnetic susceptibility and electrical resistivity studies of the heavy fermion system CeNi(9-x)Cu(x)Ge(4) (0≤x≤1) reveal a continuous tuning of the ground state by Ni/Cu substitution from an effectively fourfold-degenerate non-magnetic Kondo ground state of CeNi(9)Ge(4) (with pronounced non-Fermi-liquid features) towards a magnetically ordered, effectively twofold-degenerate ground state in CeNi(8)CuGe(4) with T(N) = 175 ± 5 mK. Quantum critical behavior, [Formula: see text], is observed for [Formula: see text]. Hitherto, CeNi(9-x)Cu(x)Ge(4) represents the first system where a substitution-driven quantum phase transition is connected not only with changes of the relative strength of the Kondo effect and RKKY interaction, but also with a reduction of the effective crystal field ground state degeneracy.

Elements of Scenario-Based Learning on Suicidal Patient Care Using Real-Time Video.

PubMed

Lu, Chuehfen; Lee, Hueying; Hsu, Shuhui; Shu, Inmei

2016-01-01

This study aims understanding of students' learning experiences when receiving scenario-based learning combined with real-time video. Videos that recorded student nurses intervention with a suicidal standardized patient (SP) were replayed immediately as teaching materials. Videos clips and field notes from ten classes were analysed. Investigators and method triangulation were used to boost the robustness of the study. Three key elements, emotional involvement, concretizing of the teaching material and substitute learning were identified. Emotions were evoked among the SP, the student performer and the students who were observing, thus facilitating a learning effect. Concretizing of the teaching material refers to students were able to focus on the discussions using visual and verbal information. Substitute learning occurred when the students watching the videos, both the strengths and weaknesses represented were similar to those that would be likely to occur. These key elements explicate their learning experience and suggested a strategic teaching method.

Evaluation of readily accessible azoles as mimics of the aromatic ring of D-phenylalanine in the turn region of gramicidin S.

PubMed

van der Knaap, Matthijs; Lageveen, Lianne T; Busscher, Henk J; Mars-Groenendijk, Roos; Noort, Daan; Otero, José M; Llamas-Saiz, Antonio L; van Raaij, Mark J; van der Marel, Gijsbert A; Overkleeft, Herman S; Overhand, Mark

2011-05-02

The influence of replacing the d-phenylalanine residue with substituted and unsubstituted azoles on the structure and biological activity of the antibiotic gramicidin S was investigated against a representative panel of Gram-positive and Gram-negative bacteria strains. Substituted triazole derivatives, obtained using a convergent synthetic strategy, are as active as gramicidin S, provided that any substituent on the triazole moiety is not too large. The unsubstituted triazole derivative was biologically less active than the parent natural product, gramicidin S. In general for the triazole series, the hemolytic activity could be correlated with the antibacterial activity, that is, the higher the antibacterial activity, the higher the toxicity towards blood cells. Interestingly, its imidazole counterpart showed high antibacterial activity, combined with significantly diminished hemolytic activity. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Taxation and tobacco control: the cases of Brazil and Mexico].

PubMed

de Miera-Juárez, Belén Sáenz; Iglesias, Roberto

2010-01-01

This study analyzes the achievements, obstacles and challenges related to cigarette taxes in Brazil and Mexico. Both countries have increased cigarette taxes in recent years and have included a specific tax, which allows maximizing the impact of tax increases on prices. However, it seems they have not taken full advantage of these measures. Three recommendations follow from these experiences: 1) specific taxes must represent a significant percentage of final prices; 2) specific taxes must be regularly adjusted to keep pace with cumulative inflation; and 3) specific taxes must be adjusted to compensate increases in personal income. It is also important to consider that taxes on legal substitutes of cigarettes must be similar to cigarette taxes. As for illegal substitutes, the issue is to reduce the incentives for illicit trade and to make illegal transactions more difficult. Modifications to national legislation and international cooperation constitute key elements to achieve this.

DNA Barcoding Meets Nanotechnology: Development of a Universal Colorimetric Test for Food Authentication.

PubMed

Valentini, Paola; Galimberti, Andrea; Mezzasalma, Valerio; De Mattia, Fabrizio; Casiraghi, Maurizio; Labra, Massimo; Pompa, Pier Paolo

2017-07-03

Food trade globalization and the growing demand for selected food varieties have led to the intensification of adulteration cases, especially in the form of species substitution and mixing with cheaper taxa. This phenomenon has huge economic impact and sometimes even public health implications. DNA barcoding represents a well-proven molecular approach to assess the authenticity of food items, although its use is hampered by analytical constraints and timeframes that are often prohibitive for the food market. To address such issues, we have introduced a new technology, named NanoTracer, that allows for rapid and naked-eye molecular traceability of any food and requires limited instrumentation and cost-effective reagents. Moreover, unlike sequencing, this method can be used to identify not only the substitution of a fine ingredient, but also its dilution with cheaper ones. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficient ultrasound-assisted synthesis, spectroscopic, crystallographic and biological investigations of pyrazole-appended quinolinyl chalcones

NASA Astrophysics Data System (ADS)

Prasath, R.; Bhavana, P.; Sarveswari, S.; Ng, Seik Weng; Tiekink, Edward R. T.

2015-02-01

Two series of new quinolinyl chalcones containing a pyrazole group, 3a-f and 4a-r, have been synthesized by Claisen-Schmidt condensation of the derivatives of 2-methyl-3-acetylquinoline with either substituted 1,3-diphenyl-1H-pyrazole-4-carbaldehyde or 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde in 76-93% yield under ultrasonic method. The compounds were characterized using IR, 1H NMR and ESI-MS spectroscopic methods and, for representative compounds, by X-ray crystallography. An E-configuration about the Cdbnd C ethylene bond has been established via 1H NMR spectroscopy and X-ray crystallography. These compounds show promising anti-microbial properties, with 4a and 3e being the most potent against bacterial and fungal strains, respectively and the methoxy substituted compounds showed moderate anti-oxidant activity.

High-throughput sequencing of three Lemnoideae (duckweeds) chloroplast genomes from total DNA.

PubMed

Wang, Wenqin; Messing, Joachim

2011-01-01

Chloroplast genomes provide a wealth of information for evolutionary and population genetic studies. Chloroplasts play a particularly important role in the adaption for aquatic plants because they float on water and their major surface is exposed continuously to sunlight. The subfamily of Lemnoideae represents such a collection of aquatic species that because of photosynthesis represents one of the fastest growing plant species on earth. We sequenced the chloroplast genomes from three different genera of Lemnoideae, Spirodela polyrhiza, Wolffiella lingulata and Wolffia australiana by high-throughput DNA sequencing of genomic DNA using the SOLiD platform. Unfractionated total DNA contains high copies of plastid DNA so that sequences from the nucleus and mitochondria can easily be filtered computationally. Remaining sequence reads were assembled into contiguous sequences (contigs) using SOLiD software tools. Contigs were mapped to a reference genome of Lemna minor and gaps, selected by PCR, were sequenced on the ABI3730xl platform. This combinatorial approach yielded whole genomic contiguous sequences in a cost-effective manner. Over 1,000-time coverage of chloroplast from total DNA were reached by the SOLiD platform in a single spot on a quadrant slide without purification. Comparative analysis indicated that the chloroplast genome was conserved in gene number and organization with respect to the reference genome of L. minor. However, higher nucleotide substitution, abundant deletions and insertions occurred in non-coding regions of these genomes, indicating a greater genomic dynamics than expected from the comparison of other related species in the Pooideae. Noticeably, there was no transition bias over transversion in Lemnoideae. The data should have immediate applications in evolutionary biology and plant taxonomy with increased resolution and statistical power.

High-Throughput Sequencing of Three Lemnoideae (Duckweeds) Chloroplast Genomes from Total DNA

PubMed Central

Wang, Wenqin; Messing, Joachim

2011-01-01

Background Chloroplast genomes provide a wealth of information for evolutionary and population genetic studies. Chloroplasts play a particularly important role in the adaption for aquatic plants because they float on water and their major surface is exposed continuously to sunlight. The subfamily of Lemnoideae represents such a collection of aquatic species that because of photosynthesis represents one of the fastest growing plant species on earth. Methods We sequenced the chloroplast genomes from three different genera of Lemnoideae, Spirodela polyrhiza, Wolffiella lingulata and Wolffia australiana by high-throughput DNA sequencing of genomic DNA using the SOLiD platform. Unfractionated total DNA contains high copies of plastid DNA so that sequences from the nucleus and mitochondria can easily be filtered computationally. Remaining sequence reads were assembled into contiguous sequences (contigs) using SOLiD software tools. Contigs were mapped to a reference genome of Lemna minor and gaps, selected by PCR, were sequenced on the ABI3730xl platform. Conclusions This combinatorial approach yielded whole genomic contiguous sequences in a cost-effective manner. Over 1,000-time coverage of chloroplast from total DNA were reached by the SOLiD platform in a single spot on a quadrant slide without purification. Comparative analysis indicated that the chloroplast genome was conserved in gene number and organization with respect to the reference genome of L. minor. However, higher nucleotide substitution, abundant deletions and insertions occurred in non-coding regions of these genomes, indicating a greater genomic dynamics than expected from the comparison of other related species in the Pooideae. Noticeably, there was no transition bias over transversion in Lemnoideae. The data should have immediate applications in evolutionary biology and plant taxonomy with increased resolution and statistical power. PMID:21931804

Psoas muscle area is not representative of total skeletal muscle area in the assessment of sarcopenia in ovarian cancer.

PubMed

Rutten, Iris J G; Ubachs, Jorne; Kruitwagen, Roy F P M; Beets-Tan, Regina G H; Olde Damink, Steven W M; Van Gorp, Toon

2017-08-01

Computed tomography measurements of total skeletal muscle area can detect changes and predict overall survival (OS) in patients with advanced ovarian cancer. This study investigates whether assessment of psoas muscle area reflects total muscle area and can be used to assess sarcopenia in ovarian cancer patients. Ovarian cancer patients (n = 150) treated with induction chemotherapy and interval debulking were enrolled retrospectively in this longitudinal study. Muscle was measured cross sectionally with computed tomography in three ways: (i) software quantification of total skeletal muscle area (SMA); (ii) software quantification of psoas muscle area (PA); and (iii) manual measurement of length and width of the psoas muscle to derive the psoas surface area (PLW). Pearson correlation between the different methods was studied. Patients were divided into two groups based on the extent of change in muscle area, and agreement was measured with kappa coefficients. Cox-regression was used to test predictors for OS. Correlation between SMA and both psoas muscle area measurements was poor (r = 0.52 and 0.39 for PA and PLW, respectively). After categorizing patients into muscle loss or gain, kappa agreement was also poor for all comparisons (all κ < 0.40). In regression analysis, SMA loss was predictive of poor OS (hazard ratio 1.698 (95%CI 1.038-2.778), P = 0.035). No relationship with OS was seen for PA or PLW loss. Change in psoas muscle area is not representative of total muscle area change and should not be used to substitute total skeletal muscle to predict survival in patients with ovarian cancer. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

Preliminary study of silica aerogel as a gas-equivalent material in ionization chambers

NASA Astrophysics Data System (ADS)

Caresana, M.; Zorloni, G.

2017-12-01

Since about two decades, a renewed interest on aerogels has risen. These peculiar materials show fairly unique properties. Thus, they are under investigation for both scientific and commercial purposes and new optimized production processes are studied. In this work, the possibility of using aerogel in the field of radiation detection is explored. The idea is to substitute the gas filling in a ionization chamber with the aerogel. The material possesses a density about 100 times greater than ambient pressure air. Where as the open-pore structure should allow the charge carriers to move freely. Small hydrophobic silica aerogel samples were studied. A custom ionization chamber, capable of working both with aerogel or in the classic gas set up, was built. The response of the chamber in current mode was investigated using an X-ray tube. The results obtained showed, under proper conditions, an enhancement of about 60 times of the current signal in the aerogel configuration with respect to the classic gas one. Moreover, some unusual behaviours were observed, i.e. time inertia of the signal and super-/sub-linear current response with respect to the dose rate. While testing high electric fields, aerogel configuration seemed to enhance the Townsend's effects. In order to represent the observed trends, a trapping-detrapping model is proposed, which is capable to predict semi-empirically the steady state currents measured. The time evolution of the signal is semi-quantitatively represented by the same model. The coefficients estimated by the fits are in agreement with similar trapping problems in the literature. In particular, a direct comparison between the benchmark of the FET silica gates and aerogel case endorses the idea that the same type of phenomenon occurs in the studied case.

Modelling and validation of electromechanical shock absorbers

NASA Astrophysics Data System (ADS)

Tonoli, Andrea; Amati, Nicola; Girardello Detoni, Joaquim; Galluzzi, Renato; Gasparin, Enrico

2013-08-01

Electromechanical vehicle suspension systems represent a promising substitute to conventional hydraulic solutions. However, the design of electromechanical devices that are able to supply high damping forces without exceeding geometric dimension and mass constraints is a difficult task. All these challenges meet in off-road vehicle suspension systems, where the power density of the dampers is a crucial parameter. In this context, the present paper outlines a particular shock absorber configuration where a suitable electric machine and a transmission mechanism are utilised to meet off-road vehicle requirements. A dynamic model is used to represent the device. Subsequently, experimental tests are performed on an actual prototype to verify the functionality of the damper and validate the proposed model.

A statistical model of extreme storm rainfall

NASA Astrophysics Data System (ADS)

Smith, James A.; Karr, Alan F.

1990-02-01

A model of storm rainfall is developed for the central Appalachian region of the United States. The model represents the temporal occurrence of major storms and, for a given storm, the spatial distribution of storm rainfall. Spatial inhomogeneities of storm rainfall and temporal inhomogeneities of the storm occurrence process are explicitly represented. The model is used for estimating recurrence intervals of extreme storms. The parameter estimation procedure developed for the model is based on the substitution principle (method of moments) and requires data from a network of rain gages. The model is applied to a 5000 mi2 (12,950 km2) region in the Valley and Ridge Province of Virginia and West Virginia.