Role of Tartaric Acid in Chemical, Mechanical and Self-Healing Behaviors of a Calcium-Aluminate Cement Blend with Fly Ash F under Steam and Alkali Carbonate Environments at 270°C

DOE PAGES

Pyatina, Tatiana; Sugama, Toshifumi

2017-03-25

Tartaric acid (TA) changes short-term mechanical behavior and phase composition of sodium-metasilicate activated calcium-aluminate cement blend with fly ash, type F, when used as a set control additive to allow sufficient pumping time for underground well placement. The present work focuses on TA effect on self-healing properties of the blend under steam or alkali carbonate environments at 270°C applicable to geothermal wells. Compressive strength recoveries and cracks sealing were examined to evaluate self-healing of the cement after repeated crush tests followed by two consecutive healing periods of 10 and 5 days at 270°C. Optical and scanning electron microscopes, X-ray diffraction,more » Fourier Transform infrared and EDX measurements along with thermal gravimetric analyses were used to identify phases participating in the healing processes. Samples with 1% mass fraction of TA by weight of blend demonstrated improved strength recoveries and crack plugging properties, especially in alkali carbonate environment. This effect was attributed to silicon-rich (C,N)-A-S-H amorphous phase predominant in TA-modified samples, high-temperature stable zeolite phases along with the formation of tobermorite-type crystals in the presence of tartaric acid.« less

Antilisterial activity and consumer acceptance of irradiated chicken breast meat vacuum-infused with grape seed and green tea extracts and tartaric acid.

PubMed

Over, K F; Hettiarachchy, N S; Perumalla, A V S; Johnson, M G; Meullenet, J-F; Dickson, J S; Holtzbauer, M J; Niebuhr, S E; Davis, B

2010-09-01

Contamination of poultry with pathogenic bacteria contributes to human foodborne disease, causes damage to industry brand names, and has a significant economic impact on the food industry in the form of both damage to industry brand names and losses associated with recalls. Irradiation is a safe and effective means of decontaminating poultry products, but the maximum dose strengths allowed negatively impact poultry sensory quality characteristics. The 1st objective of this study was to investigate the potential interactive inhibitory effects of natural antimicrobials as components of a vacuum-marination in addition to various dose levels of irradiation. Tartaric acid (TA) at 2 levels and grape seed (GS) and green tea (GT) extracts were combined, vacuum-infused into chicken breast fillets, and irradiated at 1, 2, and 3 kGy by electron beam irradiation. The 2nd objective was to use a consumer test group to evaluate TA and plant extract infusion into chicken breast fillets with and without irradiation at 2 kGy on overall impression, flavor, texture, appearance, and tenderness. The results showed that samples vacuum-infused with TA at 37.5 and 75.0 mM and irradiated at 1 kGy significantly reduced Listeria monocytogenes (L.m.) levels by 2 and 3 log CFU/g compared to the control after 12 d of refrigerated storage. Vacuum-infusion of TA at 37.5 and 75.0 mM at 2 and 3 kGy irradiation, reduced L.m. to near nondetectable levels. The addition of TA and GS and GT to chicken breast fillets with and without irradiation did not significantly impact consumer preference, tenderness, appearance, or flavor. The addition of tartaric acid and natural plant extracts to chicken marinades could contribute to the prevention of L.m. contamination.

Gas-phase Conformational Analysis of (R,R)-Tartaric Acid, its Diamide, N,N,N',N'- Tetramethyldiamide and Model Compounds

NASA Astrophysics Data System (ADS)

Hoffmann, Marcin; Szarecka, Agnieszka; Rychlewski, Jacek

A review over most recent ab initio studies carried out at both RHF and MP2 levels on (R,R)-tartaric acid (TA), its diamide (DA), tetramethyldiamide (TMDA) and on three prototypic model systems (each of them constitutes a half of the respective parental molecule), i.e. 2-hydroxyacetic acid (HA), 2-hydroxyacetamide (HD) and 2-hydroxy-N,N-dimethylacetamide (HMD) is presented. (R,R)-tartaric acid and the derivatives have been completely optimized at RHF/6-31G* level and subsequently single-point energies of all conformers have been calculated with the use of second order perturbation theory according to the scheme: MP2/6-31G*//RHF/6-31G*. In the complete optimization of the model molecules at RHF level we have employed relatively large basis sets, augmented with polarisation and diffuse functions, namely 3-21G, 6-31G*, 6-31++G** and 6-311++G**. Electronic correlation has been included with the largest basis set used in this study, i.e. MP2/6-311++G**//RHF/6-311++G** single-point energy calculations have been performed. General confomational preferences of tartaric acid derivatives have been analysed as well as an attempt has been made to define main factors affecting the conformational behaviour of these molecules in the isolated state, in particular, the role and stability of intramolecular hydrogen bonding. In the case of the model compounds, our study principally concerned the conformational preferences and hydrogen bonding structure within the [alpha]-hydroxy-X moiety, where X=COOH, CONH2, CON(CH3)2.

Ascorbate metabolism and the developmental demand for tartaric and oxalic acids in ripening grape berries

PubMed Central

2009-01-01

Background Fresh fruits are well accepted as a good source of the dietary antioxidant ascorbic acid (Asc, Vitamin C). However, fruits such as grapes do not accumulate exceptionally high quantities of Asc. Grapes, unlike most other cultivated fruits do however use Asc as a precursor for the synthesis of both oxalic (OA) and tartaric acids (TA). TA is a commercially important product in the wine industry and due to its acidifying effect on crushed juice it can influence the organoleptic properties of the wine. Despite the interest in Asc accumulation in fruits, little is known about the mechanisms whereby Asc concentration is regulated. The purpose of this study was to gain insights into Asc metabolism in wine grapes (Vitis vinifera c.v. Shiraz.) and thus ascertain whether the developmental demand for TA and OA synthesis influences Asc accumulation in the berry. Results We provide evidence for developmentally differentiated up-regulation of Asc biosynthetic pathways and subsequent fluctuations in Asc, TA and OA accumulation. Rapid accumulation of Asc and a low Asc to dehydroascorbate (DHA) ratio in young berries was co-ordinated with up-regulation of three of the primary Asc biosynthetic (Smirnoff-Wheeler) pathway genes. Immature berries synthesised Asc in-situ from the primary pathway precursors D-mannose and L-galactose. Immature berries also accumulated TA in early berry development in co-ordination with up-regulation of a TA biosynthetic gene. In contrast, ripe berries have up-regulated expression of the alternative Asc biosynthetic pathway gene D-galacturonic acid reductase with only residual expression of Smirnoff-Wheeler Asc biosynthetic pathway genes and of the TA biosynthetic gene. The ripening phase was further associated with up-regulation of Asc recycling genes, a secondary phase of increased accumulation of Asc and an increase in the Asc to DHA ratio. Conclusion We demonstrate strong developmental regulation of Asc biosynthetic, recycling and catabolic

Rapid Photodegradation of Methyl Orange (MO) Assisted with Cu(II) and Tartaric Acid

PubMed Central

Guo, Jing; Chen, Xue; Shi, Ying; Lan, Yeqing; Qin, Chao

2015-01-01

Cu(II) and organic carboxylic acids, existing extensively in soil and aquatic environments, can form complexes that may play an important role in the photodegradation of organic contaminants. In this paper, the catalytic role of Cu(II) in the removal of methyl orange (MO) in the presence of tartaric acid with light was investigated through batch experiments. The results demonstrate that the introduction of Cu(II) could markedly enhance the photodegradation of MO. In addition, high initial concentrations of Cu(II) and tartaric acid benefited the decomposition of MO. The most rapid removal of MO assisted by Cu(II) was achieved at pH 3. The formation of Cu(II)-tartaric acid complexes was assumed to be the key factor, generating hydroxyl radicals (•OH) and other oxidizing free radicals under irradiation through a ligand-to-metal charge-transfer pathway that was responsible for the efficient degradation of MO. Some intermediates in the reaction system were also detected to support this reaction mechanism. PMID:26241043

Influence of tartaric acid on linear-nonlinear optical and electrical properties of KH2PO4 crystal

NASA Astrophysics Data System (ADS)

Baig, M. I.; Anis, Mohd; Muley, G. G.

2017-10-01

KH2PO4 (KDOP) is widely demanded technological crystal for applications in laser driven photonic devices. Therefore, present article is focused to investigate the effect of tartaric acid (TA) on laser induced nonlinear optical properties of KDOP crystal. The optically transparent TA doped KDOP crystal of size 15 × 10 × 04 mm3 has been grown by slow solvent evaporation technique at 35 °C. The structural analysis of pure and TA doped KDOP crystal has been achieved by means of single crystal X-ray diffraction technique. The functional groups of TA doped KDOP crystal has been identified by means of Fourier transform infrared spectral analysis. The UV-visible studies have been performed to determine the optical transparency and evaluate the linear optical constants of pure and TA doped KDOP crystal. The Kurtz-Perry test has been employed to confirm the frequency doubling phenomenon of crystal and the SHG efficiency of TA doped KDOP crystal is found to be 5.68 times higher than that of standard KDP material. The Z-scan technique has been employed to explore the third order nonlinear optical (TONLO) refraction (n2), absorption (β) and susceptibility (χ3) of pure and TA doped KDOP crystal at 632.8 nm. The TA facilitated optical switching in TONLO response of KDOP crystal is found to be an interesting effect to examine. The laser damage threshold of TA doped KDOP crystal has been determined at 1064 nm using the Nd:YAG laser. The comparative electrical analysis on pure and TA doped KDOP crystal has been accomplished by means of dielectric and photoconductivity characterization studies.

Metabolism of hydroxycinnamic acids and their tartaric acid esters by Brettanomyces and Pediococcus in red wines.

USDA-ARS?s Scientific Manuscript database

Caffeic, p-coumaric, and ferulic acids and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric, respectively) are found in wines in varying concentrations. While Brettanomyces and Pediococcus can utilize the free acids, it is not known whether they can metabolize the correspon...

Control of oenological products: discrimination between different botanical sources of L-tartaric acid by isotope ratio mass spectrometry.

PubMed

Moreno Rojas, Jose Manuel; Cosofret, Sorin; Reniero, Fabiano; Guillou, Claude; Serra, Francesca

2007-01-01

Following previous studies on counterfeit of wines with synthetic ingredients, the possibility of frauds by natural external L-tartaric acid has also been investigated. The aim of this research was to map the stable isotope ratios of L-tartaric acid coming from botanical species containing large amounts of this compound: grape and tamarind. Samples of L-tartaric acid were extracted from the pulp of tamarind fruits originating from several countries and from grape must. delta(13)C and delta(18)O were measured for all samples. Additional delta(2)H measurements were performed as a complementary analysis to help discrimination of the botanical origin. Different isotopic patterns were observed for the different botanical origins. The multivariate statistical analysis of the data shows clear discrimination among the different botanical and synthetic sources. This approach could be a complementary tool for the control of L-tartaric acid used in oenology. Copyright (c) 2007 John Wiley & Sons, Ltd.

Chemical speciation and mobilization of copper and zinc in naturally contaminated mine soils with citric and tartaric acids.

PubMed

Pérez-Esteban, Javier; Escolástico, Consuelo; Moliner, Ana; Masaguer, Alberto

2013-01-01

A one-step extraction procedure and a leaching column experiment were performed to assess the effects of citric and tartaric acids on Cu and Zn mobilization in naturally contaminated mine soils to facilitate assisted phytoextraction. A speciation modeling of the soil solution and the metal fractionation of soils were performed to elucidate the chemical processes that affected metal desorption by organic acids. Different extracting solutions were prepared, all of which contained 0.01 M KNO(3) and different concentrations of organic acids: control without organic acids, 0.5 mM citric, 0.5 mM tartaric, 10 mM citric, 10 mM tartaric, and 5 mM citric +5 mM tartaric. The results of the extraction procedure showed that higher concentrations of organic acids increased metal desorption, and citric acid was more effective at facilitating metal desorption than tartaric acid. Metal desorption was mainly influenced by the decreasing pH and the dissolution of Fe and Mn oxides, not by the formation of soluble metal-organic complexes as was predicted by the speciation modeling. The results of the column study reported that low concentrations of organic acids did not significantly increase metal mobilization and that higher doses were also not able to mobilize Zn. However, 5-10 mM citric acid significantly promoted Cu mobilization (from 1 mg kg(-1) in the control to 42 mg kg(-1) with 10 mM citric acid) and reduced the exchangeable (from 21 to 3 mg kg(-1)) and the Fe and Mn oxides (from 443 to 277 mg kg(-1)) fractions. Citric acid could efficiently facilitate assisted phytoextraction techniques. Copyright © 2012 Elsevier Ltd. All rights reserved.

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

Code of Federal Regulations, 2014 CFR

2014-04-01

... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food and... Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or...

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

Code of Federal Regulations, 2013 CFR

2013-04-01

... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food and... Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or...

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

Code of Federal Regulations, 2012 CFR

2012-04-01

... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food and... Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or...

Structural, vibrational and thermal studies of a new nonlinear optical material: L-asparagine-L-tartaric acid.

PubMed

Moovendaran, K; Srinivasan, Bikshandarkoil R; Kalyana Sundar, J; Martin Britto Dhas, S A; Natarajan, S

2012-06-15

Crystals of a new nonlinear optical (NLO) material, viz., L-asparagine-L-tartaric acid (LALT) (1) were grown by slow evaporation of an aqueous solution containing equimolar concentrations of L-asparagine and L-tartaric acid. The structure of the title compound which crystallizes in the non-centrosymmetric monoclinic space group P2(1) consists of a molecule of L-asparagine and a molecule of free l-tartaric acid both of which are interlinked by three varieties of H-bonding interactions namely O-H···O, N-H···O and C-H···O. The UV-Vis-NIR spectrum of 1 reveals its transparent nature while the vibrational spectra confirm the presence of the functional groups in 1. The thermal stability and second harmonic generation (SHG) conversion efficiency of 1 were investigated. Copyright © 2012 Elsevier B.V. All rights reserved.

Transcriptome mining and in silico structural and functional analysis of ascorbic acid and tartaric acid biosynthesis pathway enzymes in rose-scanted geranium.

PubMed

Narnoliya, Lokesh K; Sangwan, Rajender S; Singh, Sudhir P

2018-06-01

Rose-scented geranium (Pelargonium sp.) is widely known as aromatic and medicinal herb, accumulating specialized metabolites of high economic importance, such as essential oils, ascorbic acid, and tartaric acid. Ascorbic acid and tartaric acid are multifunctional metabolites of human value to be used as vital antioxidants and flavor enhancing agents in food products. No information is available related to the structural and functional properties of the enzymes involved in ascorbic acid and tartaric acid biosynthesis in rose-scented geranium. In the present study, transcriptome mining was done to identify full-length genes, followed by their bioinformatic and molecular modeling investigations and understanding of in silico structural and functional properties of these enzymes. Evolutionary conserved domains were identified in the pathway enzymes. In silico physicochemical characterization of the catalytic enzymes revealed isoelectric point (pI), instability index, aliphatic index, and grand average hydropathy (GRAVY) values of the enzymes. Secondary structural prediction revealed abundant proportion of alpha helix and random coil confirmations in the pathway enzymes. Three-dimensional homology models were developed for these enzymes. The predicted structures showed significant structural similarity with their respective templates in root mean square deviation analysis. Ramachandran plot analysis of the modeled enzymes revealed that more than 84% of the amino acid residues were within the favored regions. Further, functionally important residues were identified corresponding to catalytic sites located in the enzymes. To, our best knowledge, this is the first report which provides a foundation on functional annotation and structural determination of ascorbic acid and tartaric acid pathway enzymes in rose-scanted geranium.

Spectra investigation on surface characteristics of graphene oxide nanosheets treated with tartaric, malic and oxalic acids.

PubMed

Teng, Xiyao; Yan, Manqing; Bi, Hong

2014-01-24

The surface characteristics of graphene oxide nanosheets (GO) treated respectively with tartaric acid, malic acid and oxalic acid, have been investigated by mainly using optical spectroscopic methods including Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible (UV-Vis) absorption and Raman spectroscopy. Additionally, the electrochemical property of the products has also been studied. The data revealed that oxygen-containing groups such as OH, COOH and CO on the GO surface have been almost removed and thus reduced graphene oxide nanosheets (RGN) were obtained. Interestingly, the number of sp(2) domains of RGN increases as treated by tartaric acidacidacid whereas the steric hindrance (SH) decreases and the ionization constant (IC) differs among these three acids. Furthermore, the specific capacitances (Cs) of GO have been greatly promoted from 2.4 F g(-1) to 100.8, 112.4, and 147 F g(-1) after treated with tartaric, malic and oxalic acids, respectively. This finding agrees well with the spectra result of the tendency of surface conjugated degree alteration. We claim that the difference in both SH and IC among these acids is the main reason for the diverse surface characteristics as well as the improved Cs of the RGN. Copyright © 2013 Elsevier B.V. All rights reserved.

INTERACTION OF AQUEOUS SOLUTIONS OF CHLORINE WITH MALIC ACID, TARTARIC ACID, AND VARIOUS FRUIT JUICES, A SOURCE OF MUTAGENS

EPA Science Inventory

The interactions of aqueous solutions of chlorine with some fruit acids (citric acid, DL-malic acid, and L-tartaric acid) at different pH values were studied. iethyl ether extraction followed by GC/MS analysis indicated that a number of mutagens (certain chlorinated propanones an...

Highly Selective Deoxydehydration of Tartaric Acid over Supported and Unsupported Rhenium Catalysts with Modified Acidities.

PubMed

Li, Xiukai; Zhang, Yugen

2016-10-06

The deoxydehydration (DODH) of sugar acids to industrially important carboxylic acids is a very attractive topic. Oxorhenium complexes are the most-often employed DODH catalysts. Because of the acidity of the rhenium catalysts, the DODH products of sugar acids were usually in the form of mixture of free carboxylic acids and esters. Herein, we demonstrate strategies for the selective DODH of sugar acids to free carboxylic acids by tuning the Lewis acidity or the Brønsted acidity of the rhenium-based catalysts. Starting from tartaric acid, up to 97 % yield of free maleic acid was achieved. Based on our strategies, functional polymer immobilized heterogeneous rhenium catalysts were also developed for the selective DODH conversion of sugar acids. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tartaric Acid as a Non-toxic and Environmentally-Friendly Anti-scaling Material for Using in Cooling Water Systems: Electrochemical and Surface Studies

NASA Astrophysics Data System (ADS)

Asghari, Elnaz; Gholizadeh-Khajeh, Maryam; Ashassi-Sorkhabi, Habib

2016-10-01

Because of the major limitations in drinking water resources, the industries need to use unprocessed water sources for their cooling systems; these water resources contain major amount of hardening cations. So, mineral scales are formed in cooling water systems during the time and cause major problems. The use of green anti-scaling materials such as carboxylic acids is considered due to their low risks of environmental pollution. In the present work, the scale inhibition performance of tartaric acid as a green organic material was evaluated. Chemical screening tests, cathodic and anodic voltammetry measurements and electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FESEM), energy-dispersive x-ray and x-ray diffraction, were used for the evaluation of the scale inhibition performance. The results showed that tartaric acid can prevent calcium carbonate precipitation significantly. The hard water solution with 2.0 mM of tartaric acid indicated the highest scale inhibition efficiency (ca. 68%). The voltammetry, EIS and FESEM results verified that tartaric acid can form smooth and homogeneous film on steel surface through formation of Fe(III)-tartrate complexes and retard the local precipitation of calcium carbonate deposits.

Identification of oxalic acid and tartaric acid as major persistent pain-inducing toxins in the stinging hairs of the nettle, Urtica thunbergiana.

PubMed

Fu, Han Yi; Chen, Shiang Jiuun; Chen, Ruei Feng; Ding, Wang Hsien; Kuo-Huang, Ling Long; Huang, Rong Nan

2006-07-01

Once human skin contacts stinging hairs of Urtica spp. (stinging nettles), the irritant is released and produces pain, wheals or a stinging sensation which may last for >12 h. However, the existence of pain-inducing toxins in the stinging hairs of Urtica thunbergiana has never been systematically demonstrated. Experiments were therefore conducted to identify the persistent pain-inducing agents in the stinging hairs of U. thunbergiana. The stinging hairs of U. thunbergiana were removed and immersed in deionized water. After centrifugation, the clear supernatants were then subjected to high-performance liquid chromatography (HPLC), enzymatic analysis and/or behavioural bioassays. The HPLC results showed that the major constituents in the stinging hairs of U. thunbergiana were histamine, oxalic acid and tartaric acid. However, the well-recognized pain-inducing agents, serotonin and formic acid, existed at a low concentration as estimated by HPLC and/or enzymatic analyses. The behavioural tests showed that 2% oxalic acid and 10% tartaric acid dramatically elicited persistent pain sensations in rats. In contrast, 10% formic acid and 2% serotonin only elicited moderate pain sensation in the first 10 min. Moreover, no significant pain-related behavioural response was observed after injecting 10% acetylcholine and histamine in rats. Oxalic acid and tartaric acid were identified, for the first time, as major long-lasting pain-inducing toxins in the stinging hairs of U. thunbergiana. The general view that formic acid, histamine and serotonin are the pain-inducing agents in the stinging hairs of U. dioica may require updating, since their concentrations in U. thunbergiana were too low to induce significant pain sensation in behavioural bioassays.

Performance, kinetics, and equilibrium of methylene blue adsorption on biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids.

PubMed

Sun, Lei; Chen, Dongmei; Wan, Shungang; Yu, Zebin

2015-12-01

Biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids at low temperatures was utilized as adsorbent to remove methylene blue (MB) from aqueous solutions. Fourier transform infrared spectroscopy analysis showed that the carboxyl group was introduced on the biochar surface. Adsorption experiment data indicated that eucalyptus saw dust modified with citric acid showed higher MB adsorption efficiency than that modified with tartaric and acetic acids. Pseudo-second-order kinetics was the most suitable model for describing MB adsorption on biochar compared with pseudo-first-order, Elovich, and intraparticle diffusion models. The calculated values of ΔG(0) and ΔH(0) indicated the spontaneous and endothermic nature of the adsorption process. MB adsorption on biochar followed the Langmuir isotherm. The maximum adsorption capacities for eucalyptus saw dust modified with citric, tartaric, and acetic acids were 178.57, 99.01, and 29.94 mg g(-1), respectively, at 35°C. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tartaric acid assisted hydrothermal synthesis of different flower-like ZnO hierarchical architectures with tunable optical and oxygen vacancy-induced photocatalytic properties

NASA Astrophysics Data System (ADS)

Liu, Tingzhi; Li, Yangyang; Zhang, Hao; Wang, Min; Fei, Xiaoyan; Duo, Shuwang; Chen, Ying; Pan, Jian; Wang, Wei

2015-12-01

Different flower-like ZnO hierarchical architectures were prepared by tartaric acid assisted hydrothermal synthesis, especially four flower-like ZnO nanostructures were obtained simultaneously under the same reaction condition. The cauliflower-like ZnO is assembled by spherical shaped nanoparticles, and the chrysanthemum-like and other flower-like ZnO nanostructures are assembled by hexagonal rods/prisms with from planar to semi-pyramid, and to pyramid tips. TA acts as a capping agent and structure-directing agent during the synthesis. All ZnO possess the hexagonal wurtzite structure. The PL spectra can be tuned by changing TA concentration. XRD, PL and Raman spectra confirmed that oxygen vacancies mainly come from the ZnO surface. The flower-like samples of 1:4.5 and 1:3 with the largest aspect ratios have highest photocatalytic performance. They decompose 85% MB within 60 min. Combining PL Gaussian fitting with K, the higher content of oxygen vacancy is, the higher photocatalytic activity is. The enhanced photocatalytic performance is mainly induced by oxygen vacancy of ZnO. The possible formation mechanism, growth and change process of flower-like ZnO were proposed.

Comparison between different types of carboxylmethylcellulose and other oenological additives used for white wine tartaric stabilization.

PubMed

Guise, R; Filipe-Ribeiro, L; Nascimento, D; Bessa, O; Nunes, F M; Cosme, F

2014-08-01

Carboxylmethylcellulose (CMC) is authorised to prevent wine tartaric instability. The effect of CMC structural characteristics on their effectiveness is not well understood. The main purpose of this study was to compare the impact of CMC's with different degrees of substitution and molecular weight, on tartaric stability, tartaric acid, mineral concentration, phenolic compounds, chromatic and sensory characteristics in white wines, and compare its effectiveness with other oenological additives. Mini-contact test showed that all CMC's and metatartaric acid stabilized the wines; however, some arabic gums and mannoproteins do not stabilized the wines. CMC's had no significant effect on tartaric acid, potassium, calcium and sensory attributes. Tartaric stabilization effectiveness depends on CMC's degree of substitution, but also on wine matrix, probably its initial potassium content. Results suggest that CMC is a good alternative to white wine tartaric stabilization; nevertheless deeper structure knowledge is necessary in order to choose the appropriate CMC for a given tartaric instability. Copyright © 2014 Elsevier Ltd. All rights reserved.

The structure, vibrational spectra and nonlinear optical properties of the L-lysine × tartaric acid complex—Theoretical studies

NASA Astrophysics Data System (ADS)

Drozd, M.; Marchewka, M. K.

2006-05-01

The room temperature X-ray studies of L-lysine × tartaric acid complex are not unambiguous. The disorder of three atoms of carbon in L-lysine molecule is observed. These X-ray studies are ambiguous. The theoretical geometry study performed by DFT methods explain the most doubts which are connected with crystallographic measurements. The theoretical vibrational frequencies and potential energy distribution (PED) of L-lysine × tartaric acid were calculated by B3LYP method. The calculated frequencies were compared with experimental measured IR spectra. The complete assignment of the bands has been made on the basis of the calculated PED. The restricted Hartee-Fock (RHF) methods were used for calculation of the hyperpolarizability for investigated compound. The theoretical results are compared with experimental value of β.

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

Code of Federal Regulations, 2010 CFR

2010-04-01

... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food and... Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty... edible fat-forming fatty acids. (b) Conditions of use. This substance is generally recognized as safe...

21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

Code of Federal Regulations, 2011 CFR

2011-04-01

... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food and... Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty... edible fat-forming fatty acids. (b) Conditions of use. This substance is generally recognized as safe...

Voltammetric determination of tartaric acid in wines by electrocatalytic oxidation on a cobalt(II)-phthalocyanine-modified electrode associated with multiway calibration.

PubMed

Lourenço, Anabel S; Nascimento, Raphael F; Silva, Amanda C; Ribeiro, Williame F; Araujo, Mario C U; Oliveira, Severino C B; Nascimento, Valberes B

2018-05-30

The electrocatalytic oxidation of tartaric acid on a carbon paste electrode modified with cobalt (II)-phthalocyanine was demonstrated and applied to the development of a highly sensitive, simple, fast and inexpensive voltammetric sensor to determine tartaric acid. The electrochemical behavior of the modified electrode was investigated by cyclic and square wave voltammetry, and the effect of experimental variables, such as dispersion and loading of cobalt (II)-phthalocyanine, together with optimum conditions for sensing the analyte by square wave voltammetry were assessed. In addition, the absence of a significant memory effect combined with the ease of electrode preparation led to the development of a sensitive and direct method to determine tartaric acid in wines. Interferences from other low molecular weight organic acids commonly present in wines were circumvented by using a multiway calibration technique, successfully obtaining the second order advantage by modeling voltammetric data with unfolded partial least square with residual bilinearization (U-PLS/RBL). A linear response range between 10 and 100 μmol L -1 (r = 0.9991), a relative prediction error of 4.55% and a recovery range from 96.41 to 102.43% were obtained. The proposed method is non-laborious, since it does not use sample pretreatment such as filtration, extraction, pre-concentration or cleanup procedures. Copyright © 2018 Elsevier B.V. All rights reserved.

Electrochemical characterization and electrode kinetics for antimony electrodeposition from its oxychloride solution in the presence of tartaric acid

NASA Astrophysics Data System (ADS)

Majidzade, Vusala Asim; Guliyev, Parvin Heydar; Aliyev, Akif Shikhan; Elrouby, Mahmoud; Tagiyev, Dilgam Babir

2017-05-01

This work is devoted to investigate the process of the electrochemical deposition of antimony from antimony oxychloride solution in the presence of tartaric acid in aqueous media. The kinetics and the mechanism of the electrodeposition process at the electrode surface are studied and proposed by the aid of cyclic, linear sweep voltammetric and chronoamperometric characterization methods. It is found that, the process is affected by the presence of tartaric acid and some factors during the electro-reduction process. The results also show that, the temperature, the potential sweep rate and the concentration of antimony have a great influence on the achievement of the electrodeposition process. Some important parameters are calculated such as, the activation energy of the electrochemical reaction, the diffusion coefficient and the number of saturated nucleation sites. The electrodeposited film is examined using X-ray diffraction, scanning electron microscopy and Energy Dispersive Spectroscopy.

Surface chirality of CuO thin films.

PubMed

Widmer, Roland; Haug, Franz-Josef; Ruffieux, Pascal; Gröning, Oliver; Bielmann, Michael; Gröning, Pierangelo; Fasel, Roman

2006-11-01

We present X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD) investigations of CuO thin films electrochemically deposited on an Au(001) single-crystal surface from a solution containing chiral tartaric acid (TA). The presence of enantiopure TA in the deposition process results in a homochiral CuO surface, as revealed by XPD. On the other hand, XPD patterns of films deposited with racemic tartaric acid or the "achiral" meso-tartaric acid are completely symmetric. A detailed analysis of the experimental data using single scattering cluster calculations reveals that the films grown with l(+)-TA exhibit a CuO(1) orientation, whereas growth in the presence of d(-)-TA results in a CuO(11) surface orientation. A simple bulk-truncated model structure with two terminating oxygen layers reproduces the experimental XPD data. Deposition with alternating enantiomers of tartaric acid leads to CuO films of alternating chirality. Enantiospecifity of the chiral CuO surfaces is demonstrated by further deposition of CuO from a solution containing racemic tartaric acid. The pre-deposited homochiral films exhibit selectivity toward the same enantiomeric deposition pathway.

The Scale Formation of Barite (BaSO4) from Laminar Flowing Water in The Presence of Tartaric Acid and Ba2+ Concentration Variation of Solution

NASA Astrophysics Data System (ADS)

Fatra, F.; Ivanto, G.; Dera, N. S.; Muryanto, S.; Bayuseno, A. P.

2017-05-01

The barite (BaSO4) scale is a mineral deposit that can be precipitated during the process of drilling oil and gas in the offshore. Deposite scale in pipes can cause a narrowing of the diameter of pipes, and can reduce water flowing in the pipe. The aim of this study is to investigation the effect of the tartaric acid additive and Ba2+ concentration on the growth o the scale formation of barite in the laminar flow of the piping system. Solution forming barite crystal was prepared by mixing equimolar solutions of barium chloride (BaCl2) and sodium sulfate (Na2SO4) with concentration variations of Ba2+ of 3000, 3500, 4000, 4500, and 5000 ppm. The flow rate of solution is 40 ml/min at temperature of 50 °C. Various concentrations of tartaric acid (C4H6O6) of 0 ppm, 5 ppm and 10 ppm were added to the solutions. The formation of barite from the solution was observed by ion conductivity measurement. The obtained barite crystals before and after adding tartaric acid were dried and characterized by using SEM/EDX for morphology and elemental analysis, and XRD for phase identification. The SEM results show that the morphology of the crystals are star-like particles, while XRD analysis confirmed that the barite crystals were produced during the experiments are high purity. Moreover, the tartaric acid can inhibit the crystal growth of barite.

Synergistic effect of tartaric acid with 2,6-diaminopyridine on the corrosion inhibition of mild steel in 0.5 M HCl

PubMed Central

Qiang, Yujie; Guo, Lei; Zhang, Shengtao; Li, Wenpo; Yu, Shanshan; Tan, Jianhong

2016-01-01

The inhibitive ability of 2,6-diaminopyridine, tartaric acid and their synergistic effect towards mild steel corrosion in 0.5 M HCl solution was evaluated at various concentrations using potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS), and weight loss experiments. Corresponding surfaces of mild steel were examined by atomic force microscope (AFM), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) analysis. The experimental results are in good agreement and reveal a favorable synergistic effect of 2,6-diaminopyridine with tartaric acid, which could protect mild steel from corrosion effectively. Besides, quantum chemical calculations and Monte Carlo simulation were used to clarify the inhibition mechanism of the synergistic effect. PMID:27628901

The effects of egg and diacetyl tartaric acid esters of monoglycerides addition on gluten-free sorghum bread quality

USDA-ARS?s Scientific Manuscript database

The impact of whole egg addition (as is) at 20, 25, or 30% (flour basis) on sorghum bread quality was evaluated. The use of the antistaling agent diacetyl tartaric acid esters of monoglycerides (DATEM) at 0.5% (flour basis) at each of the egg addition levels was also studied. Evaluated quality facto...

Four Structures of Tartaric Acid Revealed in the Gas Phase

NASA Astrophysics Data System (ADS)

Cortijo, Vanessa; Díez, Verónica; Alonso, Elena R.; Mata, Santiago; Alonso, José L.

2017-06-01

The tartaric acid, one of the most important organic compounds, has been transferred into the gas phase by laser ablation of its natural crystalline form (m.p.174°C) and probed in a supersonic expansion by chirped-pulse Fourier transform microwave spectroscopy (CP-FTMW). Four stable structures, two with an extended (trans) disposition of the carbon chain and two with a bent (gauche) disposition, have been unequivocally identified on the basis of the experimental rotational constants in conjunction with ab initio predictions. The intramolecular interactions that govern the conformational preferences are dominated by cooperative O-H...O=C type and O-H?O hydrogen bonds extended along the entire molecule. The observation of only μc- type spectra for one "trans" and one "gauche" conformers, support the existence of a C2 symmetry for each structure.

Preparation of long alumina fibers by sol-gel method using tartaric acid

NASA Astrophysics Data System (ADS)

Tan, Hong-Bin

2011-12-01

Long alumina fibers were prepared by sol-gel method. The spinning sol was obtained by mixing aluminum nitrate, tartaric acid, and polyvinylpyrrolidone with a mass ratio of 10:3:1.5. Thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the properties of the gel and ceramic fibers. A little of α-Al2O3 phase is observed in the alumina precursor gel fibers sintered at 1273 K. The fibers with a uniform diameter can be obtained when sintered at 1473 K, and its main phase is also indentified as α-Al2O3.

Optimization of the 3-Point Bending Failure of Anodized Aluminum Formed in Tartaric/Sulphuric Acid Using Doehlert Design

NASA Astrophysics Data System (ADS)

Bensalah, W.; Feki, M.; De-Petris Wery, M.; Ayedi, H. F.

2015-02-01

The bending failure of anodized aluminum in tartaric/sulphuric acid bath was modeled using Doehlert design. Bath temperature, anodic current density, sulphuric acid, and tartaric acid concentrations were retained as variables. Thickness measurements and 3-point bending experiments were conducted. The deflection at failure ( D f) and the maximum load ( F m) of each sample were, then, deducted from the corresponding flexural responses. The treatment of experimental results has established mathematical models of second degree reflecting the relation of cause and effect between the factors and the studied properties. The optimum path study of thickness, deflection at failure, and maximum load, showed that the three optima were opposite. Multicriteria optimization using the desirability function was achieved in order to maximize simultaneously the three responses. The optimum conditions were: C tar = 18.2 g L-1, T = 17.3 °C, J = 2.37 A dm-2, C sul = 191 g L-1, while the estimated response values were e = 57.7 µm, D f = 5.6 mm, and F m = 835 N. Using the established models, a mathematical correlation was found between deflection at failure and thickness of the anodic oxide layer. Before bending tests, aluminum oxide layer was examined by scanning electron microscopy (SEM) and atomic force microscopy. After tests, the morphology and the composition of the anodic oxide layer were inspected by SEM, optical microscopy, and glow-discharge optical emission spectroscopy.

Importance of Unimolecular HO 2 Elimination in the Heterogeneous OH Reaction of Highly Oxygenated Tartaric Acid Aerosol

DOE PAGES

Cheng, Chiu Tung; Chan, Man Nin; Wilson, Kevin R.

2016-07-09

Oxygenated organic molecules are abundant in atmospheric aerosols and are transformed by oxidation reactions near the aerosol surface by gas-phase oxidants such as hydroxyl (OH) radicals. To gain better insights into how the structure of an organic molecule, particularly in the presence of hydroxyl groups, controls the heterogeneous reaction mechanisms of oxygenated organic compounds, this paper investigates the OH-radical initiated oxidation of aqueous tartaric acid (C 4H 6O 6) droplets using an aerosol flow tube reactor. The molecular composition of the aerosols before and after reaction is characterized by a soft atmospheric pressure ionization source (Direct Analysis in Real Time)more » coupled with a high-resolution mass spectrometer. The aerosol mass spectra reveal that four major reaction products are formed: a single C 4 functionalization product (C 4H 4O 6) and three C 3 fragmentation products (C 3H 4O 4, C 3H 2O 4, and C 3H 2O 5). The C 4 functionalization product does not appear to originate from peroxy radical self-reactions but instead forms via an α-hydroxylperoxy radical produced by a hydrogen atom abstraction by OH at the tertiary carbon site. The proximity of a hydroxyl group to peroxy group enhances the unimolecular HO 2 elimination from the α-hydroxylperoxy intermediate. This alcohol-to-ketone conversion yields 2-hydroxy-3-oxosuccinic acid (C 4H 4O 6), the major reaction product. While in general, C–C bond scission reactions are expected to dominate the chemistry of organic compounds with high average carbon oxidation states (OS C), our results show that molecular structure can play a larger role in the heterogeneous transformation of tartaric acid (OS C = 1.5). Finally, these results are also compared with two structurally related dicarboxylic acids (succinic acid and 2,3-dimethylsuccinic acid) to elucidate how the identity and location of functional groups (methyl and hydroxyl groups) alter heterogeneous reaction mechanisms.« less

Effect of Tartaric Acid on Hydration of a Sodium-Metasilicate-Activated Blend of Calcium Aluminate Cement and Fly Ash F

PubMed Central

Pyatina, Tatiana; Sugama, Toshifumi; Moon, Juhyuk; James, Simon

2016-01-01

An alkali-activated blend of aluminum cement and class F fly ash is an attractive solution for geothermal wells where cement is exposed to significant thermal shocks and aggressive environments. Set-control additives enable the safe cement placement in a well but may compromise its mechanical properties. This work evaluates the effect of a tartaric-acid set retarder on phase composition, microstructure, and strength development of a sodium-metasilicate-activated calcium aluminate/fly ash class F blend after curing at 85 °C, 200 °C or 300 °C. The hardened materials were characterized with X-ray diffraction, thermogravimetric analysis, X-ray computed tomography, and combined scanning electron microscopy/energy-dispersive X-ray spectroscopy and tested for mechanical strength. With increasing temperature, a higher number of phase transitions in non-retarded specimens was found as a result of fast cement hydration. The differences in the phase compositions were also attributed to tartaric acid interactions with metal ions released by the blend in retarded samples. The retarded samples showed higher total porosity but reduced percentage of large pores (above 500 µm) and greater compressive strength after 300 °C curing. Mechanical properties of the set cements were not compromised by the retarder. PMID:28773543

Effect of Tartaric Acid on Hydration of a Sodium-Metasilicate-Activated Blend of Calcium Aluminate Cement and Fly Ash F

DOE PAGES

Pyatina, Tatiana; Sugama, Toshifumi; Moon, Juhyuk; ...

2016-05-27

An alkali-activated blend of aluminum cement and class F fly ash is an attractive solution for geothermal wells where cement is exposed to significant thermal shocks and aggressive environments. Set-control additives enable the safe cement placement in a well but may compromise its mechanical properties. Here, this work evaluates the effect of a tartaric-acid set retarder on phase composition, microstructure, and strength development of a sodium-metasilicate-activated calcium aluminate/fly ash class F blend after curing at 85 °C, 200 °C or 300 °C. The hardened materials were characterized with X-ray diffraction, thermogravimetric analysis, X-ray computed tomography, and combined scanning electron microscopy/energy-dispersivemore » X-ray spectroscopy and tested for mechanical strength. With increasing temperature, a higher number of phase transitions in non-retarded specimens was found as a result of fast cement hydration. The differences in the phase compositions were also attributed to tartaric acid interactions with metal ions released by the blend in retarded samples. The retarded samples showed higher total porosity but reduced percentage of large pores (above 500 µm) and greater compressive strength after 300 °C curing. Lastly, mechanical properties of the set cements were not compromised by the retarder.« less

Effect of Tartaric Acid on Hydration of a Sodium-Metasilicate-Activated Blend of Calcium Aluminate Cement and Fly Ash F.

PubMed

Pyatina, Tatiana; Sugama, Toshifumi; Moon, Juhyuk; James, Simon

2016-05-27

An alkali-activated blend of aluminum cement and class F fly ash is an attractive solution for geothermal wells where cement is exposed to significant thermal shocks and aggressive environments. Set-control additives enable the safe cement placement in a well but may compromise its mechanical properties. This work evaluates the effect of a tartaric-acid set retarder on phase composition, microstructure, and strength development of a sodium-metasilicate-activated calcium aluminate/fly ash class F blend after curing at 85 °C, 200 °C or 300 °C. The hardened materials were characterized with X-ray diffraction, thermogravimetric analysis, X-ray computed tomography, and combined scanning electron microscopy/energy-dispersive X-ray spectroscopy and tested for mechanical strength. With increasing temperature, a higher number of phase transitions in non-retarded specimens was found as a result of fast cement hydration. The differences in the phase compositions were also attributed to tartaric acid interactions with metal ions released by the blend in retarded samples. The retarded samples showed higher total porosity but reduced percentage of large pores (above 500 µm) and greater compressive strength after 300 °C curing. Mechanical properties of the set cements were not compromised by the retarder.

Synthesis, structures and properties of two new chiral rare earth-organic frameworks constructed by L/D-tartaric acid

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

Hu, Gonghao; Zhang, Haitao; Miao, Hao

2015-09-15

Hydrothermal reactions of rare earth cerium with L- or D- tartaric acid afford a pair of novel chiral enantiomer coordination polymers, namely, [Ce(L-tart)(CH{sub 2}OHCH{sub 2}OH)(H{sub 2}O)]Cl (L-1) and [Ce(D-tart)(CH{sub 2}OHCH{sub 2}OH)(H{sub 2}O)]Cl (D-1). Their structures were determined by single crystal X-ray diffraction analyses and further characterized by elemental analyses, XRD, IR spectra, and TG analyses. The circular dichroism (CD) spectra and second-harmonic generation (SHG) efficiency measurements proved that they are of structural chirality in the bulk samples. To the best of our knowledge, the enantiomers of L-1 and D-1 are the first 2D chiral dilayer frameworks constructed from L/D-tartrate ligands,more » ancillary ligand ethanediol and lanthanide ion Ce. - Graphical abstract: Hydrothermal reactions of rare earth cerium with L- or D- tartaric acid afford a pair of novel chiral enantiomer coordination polymers, namely, [Ce(L-tart)(CH{sub 2}OHCH{sub 2}OH)(H{sub 2}O)]Cl (L-1) and [Ce(D-tart)(CH{sub 2}OHCH{sub 2}OH)(H{sub 2}O)]Cl (D-1). Structural analysis indicates that the enantiomers of L-1 and D-1 are the first 2D chiral dilayer frameworks constructed from L/D-tartrate ligands and ancillary ligands ethanediol reacted with lanthanide ions Ce.« less

Acids with an equivalent taste lead to different erosion of human dental enamel.

PubMed

Beyer, Markus; Reichert, Jörg; Bossert, Jörg; Sigusch, Bernd W; Watts, David C; Jandt, Klaus D

2011-10-01

The consumption of acidic soft drinks may lead to demineralization and softening of human dental enamel, known as dental erosion. The aims of this in vitro study were to determine: (i) if different acids with a similar sensorial acidic taste lead to different hardness loss of enamel and (ii) if the fruit acids tartaric, malic, lactic or ascorbic acid lead to less hardness loss of enamel than citric or phosphoric acid when their concentration in solution is based on an equivalent sensorial acidic taste. Enamel samples of non-erupted human third molars were treated with acidic solutions of tartaric (TA), malic (MA), lactic (LA), ascorbic (AA), phosphoric (PA) and citric (CA) acids with a concentration that gave an equivalent sensorial acidic taste. The acidic solutions were characterized by pH value and titratable acidity. Atomic force microscopy (AFM) based nanoindentation was used to study the nano mechanical properties and scanning electron microscopy (SEM) was used to study the morphology of the treated enamel samples and the untreated control areas, respectively. The investigated acids fell into two groups. The nano hardnesses of MA, TA and CA treated enamel samples (group I) were statistically significantly greater (p<0.05) than the nano hardnesses of PA, AA and LA treated enamel samples (group II). Within each group the nano hardness was not statistically significantly different (p>0.05). The SEM micrographs showed different etch prism morphologies depending on the acid used. In vitro, the acids investigated led to different erosion effects on human dental enamel, despite their equivalent sensorial acidic taste. This has not been reported previously. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

TaOPR2 encodes a 12-oxo-phytodienoic acid reductase involved in the biosynthesis of jasmonic acid in wheat (Triticum aestivum L.).

PubMed

Wang, Yukun; Yuan, Guoliang; Yuan, Shaohua; Duan, Wenjing; Wang, Peng; Bai, Jianfang; Zhang, Fengting; Gao, Shiqing; Zhang, Liping; Zhao, Changping

2016-01-29

The 12-oxo-phytodienoic acid reductases (OPRs) are involved in the various processes of growth and development in plants, and classified into the OPRⅠ and OPRⅡ subgroups. In higher plants, only OPRⅡ subgroup genes take part in the biosynthesis of endogenous jasmonic acid. In this study, we isolated a novel OPRⅡ subgroup gene named TaOPR2 (GeneBank accession: KM216389) from the thermo-sensitive genic male sterile (TGMS) wheat cultivar BS366. TaOPR2 was predicted to encode a protein with 390 amino acids. The encoded protein contained the typical oxidored_FMN domain, the C-terminus peroxisomal-targeting signal peptide, and conserved FMN-binding sites. TaOPR2 was mapped to wheat chromosome 7B and located on peroxisome. Protein evolution analysis revealed that TaOPR2 belongs to the OPRⅡ subgroup and shares a high degree of identity with other higher plant OPR proteins. The quantitative real-time PCR results indicated that the expression of TaOPR2 is inhibited by abscisic acid (ABA), salicylic acid (SA), gibberellic acid (GA3), low temperatures and high salinity. In contrast, the expression of TaOPR2 can be induced by wounding, drought and methyl jasmonate (MeJA). Furthermore, the transcription level of TaOPR2 increased after infection with Puccinia striiformis f. sp. tritici and Puccinia recondite f. sp. tritici. TaOPR2 has NADPH-dependent oxidoreductase activity. In addition, the constitutive expression of TaOPR2 can rescue the male sterility phenotype of Arabidopsis mutant opr3. These results suggest that TaOPR2 is involved in the biosynthesis of jasmonic acid (JA) in wheat. Copyright © 2016 Elsevier Inc. All rights reserved.

A validated densitometric method for analysis of atorvastatin calcium and metoprolol tartarate as bulk drugs and in combined capsule dosage forms.

PubMed

Patole, Sm; Khodke, As; Potale, Lv; Damle, Mc

2011-01-01

A simple, accurate and precise high-performance thin-layer chromatographic method has been developed for the estimation of Atorvastatin Calcium and Metoprolol Tartarate simultaneously from a capsule dosage form. The method employed Silica gel 60F (254s)precoated plates as stationary phase and a mixture of Chloroform: Methanol: Glacial acetic acid (dil.) :: (9:1.5:0.2 ml %v/v) as mobile phase. Densitometric scanning was performed at 220 nm using Camag TLC scanner 3. The method was linear in the drug concentrations' range of 500 to 2500 ng/spot for Atorvastatin Calcium, also for Metoprolol Tartarate with correlation coefficient of 0.984 for Atorvastatin Calcium and 0.995 for Metoprolol Tartarate respectively. The retention factor for Atorvastatin Calcium was 0.45 ± 0.04 and for Metoprolol Tartarate was 0.25 ± 0.02. The method was validated as per ICH (International Conference on Harmonisation) Guidelines, proving its utility in estimation of Atorvastatin Calcium and Metoprolol Tartarate in combined dosage form.

Structural, optical, thermal and mechanical properties of Urea tartaric acid single crystals.

PubMed

Vinothkumar, P; Rajeswari, K; Kumar, R Mohan; Bhaskaran, A

2015-06-15

Urea tartaric acid (UT) an organic nonlinear optical (NLO) material was synthesized from aqueous solution and the crystals were grown by the slow evaporation technique. The single crystal X-ray diffraction (XRD) analysis revealed that the UT crystal belongs to the orthorhombic system. The functional groups of UT have been identified by the Fourier transform infrared spectral studies. The optical transparent window in the visible and near the IR regions was investigated. The transmittance of UT has been used to calculate the refractive index (n) as a function of the wavelength. The nonlinear optical property of the grown crystal has been confirmed by the Kurtz powder second harmonic generation test. The birefringence of the crystal was determined using a tungsten halogen lamp source. The laser induced surface damage threshold for the grown crystal was measured using the Nd:YAG laser. The anisotropic in mechanical property of the grown crystals was studied using Vicker's microhardness tester at different planes. The etch pit density of UT crystals was investigated. The thermal behavior of UT was investigated using the TG-DTA and DSC studies. Copyright © 2015 Elsevier B.V. All rights reserved.

De novo transcriptome analysis of rose-scented geranium provides insights into the metabolic specificity of terpene and tartaric acid biosynthesis.

PubMed

Narnoliya, Lokesh K; Kaushal, Girija; Singh, Sudhir P; Sangwan, Rajender S

2017-01-13

Rose-scented geranium (Pelargonium sp.) is a perennial herb that produces a high value essential oil of fragrant significance due to the characteristic compositional blend of rose-oxide and acyclic monoterpenoids in foliage. Recently, the plant has also been shown to produce tartaric acid in leaf tissues. Rose-scented geranium represents top-tier cash crop in terms of economic returns and significance of the plant and plant products. However, there has hardly been any study on its metabolism and functional genomics, nor any genomic expression dataset resource is available in public domain. Therefore, to begin the gains in molecular understanding of specialized metabolic pathways of the plant, de novo sequencing of rose-scented geranium leaf transcriptome, transcript assembly, annotation, expression profiling as well as their validation were carried out. De novo transcriptome analysis resulted a total of 78,943 unique contigs (average length: 623 bp, and N50 length: 752 bp) from 15.44 million high quality raw reads. In silico functional annotation led to the identification of several putative genes representing terpene, ascorbic acid and tartaric acid biosynthetic pathways, hormone metabolism, and transcription factors. Additionally, a total of 6,040 simple sequence repeat (SSR) motifs were identified in 6.8% of the expressed transcripts. The highest frequency of SSR was of tri-nucleotides (50%). Further, transcriptome assembly was validated for randomly selected putative genes by standard PCR-based approach. In silico expression profile of assembled contigs were validated by real-time PCR analysis of selected transcripts. Being the first report on transcriptome analysis of rose-scented geranium the data sets and the leads and directions reflected in this investigation will serve as a foundation for pursuing and understanding molecular aspects of its biology, and specialized metabolic pathways, metabolic engineering, genetic diversity as well as molecular breeding.

Selective Precipitation of Thorium lodate from a Tartaric Acid-Hydrogen Peroxide Medium Application to Rapid Spectrophotometric Determination of Thorium in Silicate Rocks and in Ores

USGS Publications Warehouse

Grimaldi, F.S.

1957-01-01

This paper presents a selective iodate separation of thorium from nitric acid medium containing d-tartaric acid and hydrogen peroxide. The catalytic decomposition of hydrogen peroxide is prevented by the use of 8quinolinol. A few micrograms of thorium are separated sufficiently clean from 30 mg. of such oxides as cerium, zirconium, titanium, niobium, tantalum, scandium, or iron with one iodate precipitation to allow an accurate determination of thorium with the thoronmesotartaric acid spectrophotometric method. The method is successful for the determination of 0.001% or more of thorium dioxide in silicate rocks and for 0.01% or more in black sand, monazite, thorite, thorianite, eschynite, euxenite, and zircon.

Evaluation of tartar control dentifrices in in vitro models of dentin sensitivity.

PubMed

Mason, S; Levan, A; Crawford, R; Fisher, S; Gaffar, A

1991-01-01

The effects of anticalculus dentifrices were compared with other commercially available dentifrices in in vitro models of dentin sensitivity. Changes in the hydraulic conductance of dentin discs were measured with and without a smear layer before and after treatment and also after a post-treatment acid etch. The capacity of dentifrices to occlude open dentinal tubules in vitro was also assessed by scanning electron microscopy (SEM). There was good correlation (R = 0.98) between our test and values reported in the literature. Tartar control dentifrices gave reductions in fluid flow rates through the dentin discs comparable to those obtained with Promise, Sensodyne, Thermodent and Denquel. Additionally, tartar control dentifrices did not remove microcrystalline debris (smear layers) from the surfaces of dentin in vitro. These results were confirmed by SEM. Thus, according to the hydrodynamic theory of dentin sensitivity, these in vitro results suggest that pyrophosphate-containing dentifrices should reduce dentinal sensitivity.

Analytical Method Development and Validation for the Quantification of Acetone and Isopropyl Alcohol in the Tartaric Acid Base Pellets of Dipyridamole Modified Release Capsules by Using Headspace Gas Chromatographic Technique

PubMed Central

2018-01-01

A simple, sensitive, accurate, robust headspace gas chromatographic method was developed for the quantitative determination of acetone and isopropyl alcohol in tartaric acid-based pellets of dipyridamole modified release capsules. The residual solvents acetone and isopropyl alcohol were used in the manufacturing process of the tartaric acid-based pellets of dipyridamole modified release capsules by considering the solubility of the dipyridamole and excipients in the different manufacturing stages. The method was developed and optimized by using fused silica DB-624 (30 m × 0.32 mm × 1.8 µm) column with the flame ionization detector. The method validation was carried out with regard to the guidelines for validation of analytical procedures Q2 demanded by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). All the validation characteristics were meeting the acceptance criteria. Hence, the developed and validated method can be applied for the intended routine analysis. PMID:29686931

Analytical Method Development and Validation for the Quantification of Acetone and Isopropyl Alcohol in the Tartaric Acid Base Pellets of Dipyridamole Modified Release Capsules by Using Headspace Gas Chromatographic Technique.

PubMed

Valavala, Sriram; Seelam, Nareshvarma; Tondepu, Subbaiah; Jagarlapudi, V Shanmukha Kumar; Sundarmurthy, Vivekanandan

2018-01-01

A simple, sensitive, accurate, robust headspace gas chromatographic method was developed for the quantitative determination of acetone and isopropyl alcohol in tartaric acid-based pellets of dipyridamole modified release capsules. The residual solvents acetone and isopropyl alcohol were used in the manufacturing process of the tartaric acid-based pellets of dipyridamole modified release capsules by considering the solubility of the dipyridamole and excipients in the different manufacturing stages. The method was developed and optimized by using fused silica DB-624 (30 m × 0.32 mm × 1.8  µ m) column with the flame ionization detector. The method validation was carried out with regard to the guidelines for validation of analytical procedures Q2 demanded by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). All the validation characteristics were meeting the acceptance criteria. Hence, the developed and validated method can be applied for the intended routine analysis.

Crystallization Caught in the Act with Terahertz Spectroscopy: Non-Classical Pathway for l-(+)-Tartaric Acid.

PubMed

Soltani, Amin; Gebauer, Denis; Duschek, Lennart; Fischer, Bernd M; Cölfen, Helmut; Koch, Martin

2017-10-12

Crystal formation is a highly debated problem. This report shows that the crystallization of l-(+)-tartaric acid from water follows a non-classical path involving intermediate hydrated states. Analytical ultracentrifugation indicates solution clusters of the initial stages aggregate to form an early intermediate. Terahertz spectroscopy performed during water evaporation highlights a transient increase in the absorption during nucleation; this indicates the recurrence of water molecules that are expelled from the intermediate phase. Besides, a transient resonance at 750 GHz, which can be assigned to a natural vibration of large hydrated aggregates, vanishes after the final crystal has formed. Furthermore, THz data reveal the vibration of nanosized clusters in the dilute solution indicated by analytical ultracentrifugation. Infrared spectroscopy and wide-angle X-ray scattering highlight that the intermediate is not a crystalline hydrate. These results demonstrate that nanoscopic intermediate units assemble to form the first solvent-free crystalline nuclei upon dehydration. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Growth, structural, optical, thermal and dielectric properties of lanthanum chloride—thiourea—L tartaric acid coordinated complex

NASA Astrophysics Data System (ADS)

Slathia, Goldy; Bamzai, K. K.

2017-11-01

Lanthanum chloride—thiourea—l tartaric acid coordinated complex was grown in the form of single crystal by slow evaporation of supersaturated solutions at room temperature. This coordinated complex crystallizes in orthorhombic crystal system having space group P nma. The crystallinity and purity was tested by powder x-ray diffraction. Fourier transform infra red and Raman spectroscopy analysis provide the evidences on structure and mode of coordination. The scanning electron microscopy (SEM) analysis shows the morphology evolution as brought by the increase in composition of lanthanum chloride. The band transitions due to C=O and C=S chromophores remain active in grown complexes and are recorded in the UV-vis optical spectrum. The thermal effects such as dehydration, melting and decomposition were observed by the thermogravimetric and differential thermo analytical (TGA/DTA) analysis. Electrical properties were studied by dielectric analysis in frequency range 100-30 MHz at various temperatures. Increase in values of dielectric constant was observed with change in lanthanum concentration in the coordinated complex.

[Effects of low molecular weight organic acids on redox reactions of mercury].

PubMed

Zhao, Shi-Bo; Sun, Rong-Guo; Wang, Ding-Yong; Wang, Xiao-Wen; Zhang, Cheng

2014-06-01

To study the effects of the main component of vegetation root exudates-low molecular weight organic acids on the redox reactions of mercury, laboratory experiments were conducted to investigate the roles of tartaric, citric, and succinic acid in the redox reactions of mercury, and to analyze their interaction mechanism. The results indicated that tartaric acid significantly stimulated the mercury reduction reaction, while citric acid had inhibitory effect. Succinic acid improved the reduction rate at low concentration, and inhibited the reaction at high concentration. The mercury reduction rate by tartaric acid treatment was second-order with respect to Hg2+ concentration, ranging from 0.0014 L x (ng x min)(-1) to 0.005 6 L x (ng x min)(-1). All three organic acids showed a capacity for oxidating Hg(0) in the early stage, but the oxidized Hg(0) was subsequently reduced. The oxidation capacity of the three organic acids was in the order of citric acid > tartaric acid > succinic acid.

Effect of organic acids as additives on the performance of thermoplastic starch/polyester blown films.

PubMed

Olivato, J B; Grossmann, M V E; Bilck, A P; Yamashita, F

2012-09-01

The influence of citric acid (CA), malic acid (MA) and tartaric acid (TA) in starch/poly (butylene adipate co-terephthalate) blown films was evaluated by examining the barrier, structural and mechanical properties of the films. These properties were analysed in different relative humidities. Greater concentrations of TA and CA (1.5 wt%) produced films with improved tensile strength (6.8±0.3 and 6.7±0.3 MPa, respectively), reduced water vapour permeability and a more homogeneous structure. The compatibilising effect of MA was less efficient, as shown in the scanning electron microscopy (SEM) images. Changes in the relative humidity (RH) affected the elongation of the films, which reached values of 5.7±0.5 at 33% RH and increased to 312.4±89.5% at 53% RH. The FT-IR spectra showed no additional reactions caused by the incorporation of the additives, and the observed results are attributed to the esterification reactions and/or hydrolysis of the starch, producing films with interesting properties. This process represents an alternative to the use of non-biodegradable materials. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Effects of Low-Molecular-Weight Organic Acids on the Speciation of Pb in Purple Soil and Soil Solution].

PubMed

Liu, Jiang; Jiang, Tao; Huang, Rong; Zhang, Jin-zhong; Chen, Hong

2016-04-15

Lead (Pb) in purple soil was selected as the research target, using one-step extraction method with 0.01 mol · L⁻¹ sodium nitrate as the background electrolyte to study the release effect of citric acid (CA), tartaric acid (TA) and acetic acid (AC) with different concentrations. Sequential extraction and geochemical model (Visual Minteq v3.0) were applied to analyze and predict the speciation of Pb in soil solid phase and soil solution phase. Then the ebvironmental implications and risks of low-molecule weight organic acid (LMWOA) on soil Pb were analyzed. The results indicated that all three types of LMWOA increased the desorption capacity of Pb in purple soil, and the effect followed the descending order of CA > TA > AC. After the action of LMWOAs, the exchangeable Pb increased; the carbonate-bound Pb and Fe-Mn oxide bound Pb dropped in soil solid phase. Organic bound Pb was the main speciation in soil solution phase, accounting for 45.16%-75.05%. The following speciation of Pb in soil solution was free Pb, accounting for 22.71%-50.25%. For CA and TA treatments, free Pb ions and inorganic bound Pb in soil solution increased with increasing LMWOAs concentration, while organic bound Pb suffered a decrease in this process. An opposite trend for AC treatment was observed compared with CA and TA treatments. Overall, LMWOAs boosted the bioavailability of Pb in purple soil and had a potential risk to contaminate underground water. Among the three LMWOAs in this study, CA had the largest potential to activate soil Pb.

[Effects of low molecular weight organic acids on speciation of exogenous Cu in an acid soil].

PubMed

Huang, Guo-Yong; Fu, Qing-Ling; Zhu, Jun; Wan, Tian-Ying; Hu, Hong-Qing

2014-08-01

In order to ascertain the effect of LMWOA (citric acid, tartaric acid, oxalic acid) on Cu-contaminated soils and to investigate the change of Cu species, a red soil derived from quartz sandstone deposit was added by Cu (copper) in the form of CuSO4 x 5H2O so as to simulate soil Cu pollution, keeping the additional Cu concentrations were 0, 100, 200, 400 mg x kg(-1) respectively. After 9 months, different LMWOA was also added into the simulated soil, keeping the additional LMWOAs in soil were 0, 5, 10, 20 mmol x kg(-1) respectively. After 2 weeks incubation, the modified sequential extraction method on BCR (European Communities Bureau of Reference) was used to evaluate the effects of these LMWOAs on the changes of copper forms in soil. The result showed that the percentage of weak acid dissolved Cu, the most effective form in the soil increased with three organic acids increase in quantity in the simulated polluted soil. And there was a good activation effect on Cu in the soil when organic acid added. Activation effects on Cu increased with concentration of citric acid increasing, but it showed a rise trend before they are basically remained unchanged in the case of tartaric acid and oxalic acid added in the soil. On the contrary, the state of the reduction of copper which was regarded as a complement for effective state decreased with the increased concentration of organic acid in the soil, especially with citric acid. When 20 mmol x kg(-1) oxalic acid and citric acid were added into the soil, the activation effect was the best; whereas for tartaric, the concentration was 10 mmol x kg(-1). In general, the effect on the changes of Cu forms in the soil is citric acid > tartaric acid > oxalic acid.

Oral tranexamic acid (TA) in the treatment of melasma: A retrospective analysis.

PubMed

Lee, Hwee Chyen; Thng, Tien Guan Steven; Goh, Chee Leok

2016-08-01

Melasma is a common pigmentary disorder among Asians and treatment is challenging. Oral tranexamic acid (TA) has emerged as a potential treatment for refractory melasma. Large-scale studies on its use, outcomes, and safety are limited. We sought to evaluate treatment outcomes and adverse effects of oral TA in melasma in an Asian population. We conducted a retrospective analysis of patients who received oral TA for melasma in a tertiary dermatologic center from January 2010 to June 2014. In all, 561 patients (91.4% female, 8.6% male) were enrolled. Median duration of treatment was 4 months. The majority (503 [89.7%]) improved, 56 (10.0%) had no improvement, and 2 (0.4%) worsened. Patients without family history of melasma had better response rates than those with family history (90.6% vs 60.0%, P = .01). Of the 503 who improved, response was seen within 2 months of TA initiation, with a relapse rate of 27.2%. Adverse events occurred in 40 (7.1%). Most were transient, but 1 developed deep vein thrombosis requiring prompt discontinuation. She was later given the diagnosis of familial protein S deficiency. This was a retrospective study. Oral TA may be an effective adjunct for refractory melasma. Careful screening for personal and familial risk factors for thromboembolism should be done before initiation. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Functionalized polycarbonate derived from tartaric acid: enzymatic ring-opening polymerization of a seven-membered cyclic carbonate.

PubMed

Wu, Ruizhi; Al-Azemi, Talal F; Bisht, Kirpal S

2008-10-01

Enantiomerically pure functional polycarbonate was synthesized from a novel seven-membered cyclic carbonate monomer derived from naturally occurring L-tartaric acid. The monomer was synthesized in three steps and screened for polymerization with four commercially available lipases from different sources at 80 degrees C, in bulk. The ring-opening polymerization (ROP) was affected by the source of the enzyme; the highest number-average molecular weight, M(n) = 15500 g/mol (PDI = 1.7; [alpha]D(20) = +77.8, T(m) = 58.8 degrees C) optically active polycarbonate was obtained with lipase Novozyme-435. The relationship between monomer conversion, reaction time, molecular weight, and molecular weight distribution were investigated for Novozyme-435 catalyzed ROP. Deprotection of the ketal groups was achieved with minimal polymer chain cleavage (M(n) = 10000 g/mol, PDI = 2.0) and resulted in optically pure polycarbonate ([alpha]D(20) = +56) bearing hydroxy functional groups. Deprotected poly(ITC) shows T(m) of 60.2 degrees C and DeltaH(f) = 69.56 J/g and similar to that of the poly(ITC), a glass transition temperature was not found. The availability of the pendant hydroxyl group is expected to enhance the biodegradability of the polymer and serves in a variety of potential biomedical applications such as polymeric drug delivery systems.

Design and in vitro evaluation of multiparticulate floating drug delivery system of zolpidem tartarate.

PubMed

Amrutkar, P P; Chaudhari, P D; Patil, S B

2012-01-01

Zolpidem tartarate is a non-benzodiazepine, sedative-hypnotic, which finds its major use in various types of insomnia. The present work relates to development of multiparticulate floating drug delivery system based on gas generation technique to prolong the gastric residence time and to increase the overall bioavailability. Modified release dosage form of zolpidem tartarate adapted to release over a predetermined time period, according to biphasic profile of dissolution, where the first phase is immediate release phase for inducing the sleep and the second phase is modified release phase for maintaining the sleep up to 10 h. The system consists of zolpidem tartarate layered pellets coated with effervescent layer and polymeric membrane. The floating ability and in vitro drug release of the system were dependent on amount of the effervescent agent (sodium bicarbonate) layered onto the drug layered pellets, and coating level of the polymeric membrane (Eudragit(®) NE 30D). The system could float completely within 5 min and maintain the floating over a period of 10 h. The multiparticulate floating delivery system of zolpidem tartarate with rapid floating and modified drug release was obtained. Copyright © 2011 Elsevier B.V. All rights reserved.

A novel oral delivery system consisting in "drug-in cyclodextrin-in nanostructured lipid carriers" for poorly water-soluble drug: vinpocetine.

PubMed

Lin, Congcong; Chen, Fen; Ye, Tiantian; Zhang, Lina; Zhang, Wenji; Liu, Dandan; Xiong, Wei; Yang, Xinggang; Pan, Weisan

2014-04-25

The purpose of this study was to develop a new delivery system based on drug cyclodextrin (CD) complexation and loading into nanostructured lipid carriers (NLC) to improve the oral bioavailability of vinpocetine (VP). Three different CDs and three different methods to obtain solid vinpocetine-cyclodextrin-tartaric acid complexes (VP-CD-TA) were contrasted. The co-evaporation vinpocetine-β-cyclodextrin-tartaric acid loaded NLC (VP-β-CD-TA COE-loaded NLC) was obtained by emulsification ultrasonic dispersion method. VP-β-CD-TA COE-loaded NLC was suitably characterized for particle size, polydispersity index, zeta potential, entrapment efficiency and the morphology. The crystallization of drug in VP-CD-TA and NLC was investigated by differential scanning calorimetry (DSC). The in vitro release study was carried out at pH 1.2, pH 6.8 and pH 7.4 medium. New Zealand rabbits were applied to investigate the pharmacokinetic behavior in vivo. The VP-β-CD-TA COE-loaded NLC presented a superior physicochemical property and selected to further study. In the in vitro release study, VP-β-CD-TA COE-loaded NLC exhibited a higher dissolution rate in the pH 6.8 and pH 7.4 medium than VP suspension and VP-NLC. The relative bioavailability of VP-β-CD-TA COE-loaded NLC was 592% compared with VP suspension and 92% higher than VP-NLC. In conclusion, the new formulation significantly improved bioavailability of VP for oral delivery, demonstrated a perspective way for oral delivery of poorly water-soluble drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

TaEDS1 genes positively regulate resistance to powdery mildew in wheat.

PubMed

Chen, Guiping; Wei, Bo; Li, Guoliang; Gong, Caiyan; Fan, Renchun; Zhang, Xiangqi

2018-04-01

Three EDS1 genes were cloned from common wheat and were demonstrated to positively regulate resistance to powdery mildew in wheat. The EDS1 proteins play important roles in plant basal resistance and TIR-NB-LRR protein-triggered resistance in dicots. Until now, there have been very few studies on EDS1 in monocots, and none in wheat. Here, we report on three common wheat orthologous genes of EDS1 family (TaEDS1-5A, 5B and 5D) and their function in powdery mildew resistance. Comparisons of these genes with their orthologs in diploid ancestors revealed that EDS1 is a conserved gene family in Triticeae. The cDNA sequence similarity among the three TaEDS1 genes was greater than 96.5%, and they shared sequence similarities of more than 99.6% with the respective orthologs from diploid ancestors. The phylogenetic analysis revealed that the EDS1 family originated prior to the differentiation of monocots and dicots, and EDS1 members have since undergone clear structural differentiation. The transcriptional levels of TaEDS1 genes in the leaves were obviously higher than those of the other organs, and they were induced by Blumeria graminis f. sp. tritici (Bgt) infection and salicylic acid (SA) treatment. The BSMV-VIGS experiments indicated that knock-down the transcriptional levels of the TaEDS1 genes in a powdery mildew-resistant variety of common wheat compromised resistance. Contrarily, transient overexpression of TaEDS1 genes in a susceptible common wheat variety significantly reduced the haustorium index and attenuated the growth of Bgt. Furthermore, the expression of TaEDS1 genes in the Arabidopsis mutant eds1-1 complemented its susceptible phenotype to powdery mildew. The above evidences strongly suggest that TaEDS1 acts as a positive regulator and confers resistance against powdery mildew in common wheat.

Combinatorial metabolic engineering of industrial Gluconobacter oxydans DSM2343 for boosting 5-keto-D-gluconic acid accumulation.

PubMed

Yuan, Jianfeng; Wu, Mianbin; Lin, Jianping; Yang, Lirong

2016-05-17

L-(+)-tartaric acid (L-TA) is an important organic acid, which is produced from the cream of tartar or stereospecific hydrolysis of the cis-epoxysuccinate. The former method is limited by the availability of raw material and the latter is dependent on the petrochemical material. Thus, new processes for the economical preparation of L-TA from carbohydrate or renewable resource would be much more attractive. Production of 5-keto-D-gluconate (5-KGA) from glucose by Gluconobacter oxydans is the first step to produce L-TA. The aim of this work is to enhance 5-KGA accumulation using combinatorial metabolic engineering strategies in G. oxydans. The sldAB gene, encoding sorbitol dehydrogenase, was overexpressed in an industrial strain G. oxydans ZJU2 under a carefully selected promoter, P0169. To enhance the efficiency of the oxidation by sldAB, the coenzyme pyrroloquinoline quinone (PQQ) and respiratory chain were engineered. Besides, the role in sldAB overexpression, coenzyme and respiratory chain engineering and their subsequent effects on 5-KGA production were investigated. An efficient, stable recombinant strain was constructed, whereas the 5-KGA production could be enhanced. By self-overexpressing the sldAB gene in G. oxydans ZJU2 under the constitutive promoter P0169, the resulting strain, G. oxydans ZJU3, produced 122.48 ± 0.41 g/L of 5-KGA. Furthermore, through the coenzyme and respiratory chain engineering, the titer and productivity of 5-KGA reached 144.52 ± 2.94 g/L and 2.26 g/(L · h), respectively, in a 15 L fermenter. It could be further improved the 5-KGA titer by 12.10 % through the fed-batch fermentation under the pH shift and dissolved oxygen tension (DOT) control condition, obtained 162 ± 2.12 g/L with the productivity of 2.53 g/(L · h) within 64 h. The 5-KGA production could be significantly enhanced with the combinatorial metabolic engineering strategy in Gluconobacter strain, including sldAB overexpression, coenzyme

Impact of fluorescent lighting on the browning potential of model wine solutions containing organic acids and iron.

PubMed

Grant-Preece, Paris; Barril, Celia; Schmidtke, Leigh M; Clark, Andrew C

2018-03-15

Model wine solutions containing organic acids, individually or combined, and iron(III), were exposed to light from fluorescent lamps or stored in darkness for four hours. (-)-Epicatechin was then added, and the solutions incubated in darkness for 10days. Browning was monitored by UV-visible absorption spectrophotometry and UHPLC-DAD. The pre-irradiated solutions containing tartaric acid exhibited increased yellow/brown coloration compared to the dark controls mainly due to reaction of the tartaric acid photodegradation product glyoxylic acid with (-)-epicatechin to form xanthylium cation pigments. In these solutions, browning decreased as the concentrations of organic acids other than tartaric acid increased. Xanthylium cations were also detected in the pre-irradiated malic acid solution. However, in the malic acid, succinic acid, citric acid and lactic acid solutions, any coloration was mainly due to the production of dehydrodiepicatechin A, which was largely independent of prior light exposure, but strongly affected by the organic acid present. Copyright © 2017 Elsevier Ltd. All rights reserved.

TaALMT1 promoter sequence compositions, acid tolerance, and Al tolerance in wheat cultivars and landraces from Sichuan in China.

PubMed

Han, C; Dai, S F; Liu, D C; Pu, Z J; Wei, Y M; Zheng, Y L; Wen, D J; Zhao, L; Yan, Z H

2013-11-18

Previous genetic studies on wheat from various sources have indicated that aluminum (Al) tolerance may have originated independently in USA, Brazil, and China. Here, TaALMT1 promoter sequences of 92 landraces and cultivars from Sichuan, China, were sequenced. Five promoter types (I', II, III, IV, and V) were observed in 39 cultivars, and only three promoter types (I, II, and III) were observed in 53 landraces. Among the wheat collections worldwide, only the Chinese Spring (CS) landrace native to Sichuan, China, carried the TaALMT1 promoter type III. Besides CS, two other Sichuan-bred landraces and six cultivars with TaALMT1 promoter type III were identified in this study. In the phylogenetic tree constructed based on the TaALMT1 promoter sequences, type III formed a separate branch, which was supported by a high bootstrap value. It is likely that TaALMT1 promoter type III originated from Sichuan-bred wheat landraces of China. In addition, the landraces with promoter type I showed the lowest Al tolerance among all landraces and cultivars. Furthermore, the cultivars with promoter type IV showed better Al tolerance than landraces with promoter type II. A comparison of acid tolerance and Al tolerance between cultivars and landraces showed that the landraces had better acid tolerance than the cultivars, whereas the cultivars showed better Al tolerance than the landraces. Moreover, significant difference in Al tolerance was also observed between the cultivars raised by the National Ministry of Agriculture and by Sichuan Province. Among the landraces from different regions, those from the East showed better acid tolerance and Al tolerance than those from the South and West of Sichuan. Additional Al-tolerant and acid-tolerant wheat lines were also identified.

[The matrix effects of organic acid compounds in ICP-MS].

PubMed

Nie, Xi-Du; He, Xiao-Mei; Li, Li-Bo; Xie, Hua-Lin

2007-07-01

The matrix effects arising from oxalic acid, lactic acid, tartaric acid and citric acid in inductively coupled plasma mass spectrometry (ICP-MS) were investigated. It has been proved that the sensitivity of analytes can be significantly enhanced by adding small amounts of organic acid compounds with adjusted nebulizer gas flow-rate, especially for the elements with ionization potential between 9 and 11 eV. The tartaric acid has higher enhancement effect on the signal intensity of the hard-to-ionize elements than oxalic acid, lactic acid and citric acid. The mechanism of the enhancement was investigated. The method has been used to determine Be, Zn, As, Se, Sb and Hg in water standard reference materials (SRM). The analytical results are very close to the certified values.

A Ta/W mixed addenda heteropolyacid with excellent acid catalytic activity and proton-conducting property

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

Li, Shujun; Peng, Qingpo; Chen, Xuenian, E-mail: xnchen@htu.edu.cn

A new HPAs H{sub 20}[P{sub 8}W{sub 60}Ta{sub 12}(H{sub 2}O){sub 4}(OH){sub 8}O{sub 236}]·125H{sub 2}O (H-1) which comprises a Ta/W mixed addenda heteropolyanion, 20 protons, and 125 crystalline water molecules has been prepared through ion-exchange method. The structure and properties of H-1 have been explored in detail. AC impedance measurements indicate that H-1 is a good solid state proton conducting material at room temperature with a conductivity value of 7.2×10{sup −3} S cm{sup −1} (25 °C, 30% RH). Cyclic voltammograms of H-1 indicate the electrocatalytic activity towards the reduction of nitrite. Hammett acidity constant H{sub 0} of H-1 in CH{sub 3}CN ismore » −2.91, which is the strongest among the present known HPAs. Relatively, H-1 exhibits excellent catalytic activities toward acetal reaction. - Highlights: • A Ta/W mixed addenda Heteropolyacid (H-1) was isolated. • Hammett acidity constant H{sub 0} of H-1 is the strongest among the present known HPAs. • H-1 exhibits excellent catalytic activities toward acetal reaction. • H-1 is a good solid state proton conducting material at room temperature.« less

New insights into the initial stages of Ta oxide nanotube formation on polycrystalline Ta electrodes.

PubMed

El-Sayed, Hany A; Horwood, Corie A; Abhayawardhana, Anusha D; Birss, Viola I

2013-02-21

Ta oxide nanotubes (NTs) were formed by the anodization of Ta at 15 V in a solution of concentrated sulfuric acid containing 0.8-1.0 M hydrofluoric acid. To study the initial stages of NT formation, FESEM images of samples anodized for very short times were obtained. The results contradict the existing explanation of the current-time data collected during anodization, which has persisted in the literature for more than two decades. In addition to providing a first-time morphological study of Ta oxide NT formation at very early stages of anodization, we also propose a new interpretation of the i-t response, showing that pores are already present in the first few milliseconds of anodization and that NTs are formed well before present models predict. This behaviour may also extend to the anodization of other valve metals, such as Al, Ti, Zr, W, and Nb.

Surface Modification of Ti-35Nb-10Ta-1.5Fe by the Double Acid-Etching Process

PubMed Central

Amigó, Angélica

2018-01-01

Surface topography and composition influence the osteoblastic proliferation and osseointegration rates, which favor the biomechanical stability of bone anchoring and implants. In recent years, beta titanium alloys have been developed, and are composed of biocompatible elements, have low elastic modulus, high corrosion resistance, and mechanical properties to improve the long performance behavior of biomaterials. In the present research, the influence of the acid-etching process was studied in Ti6Al4V ELI and Ti35Nb10Ta1.5Fe. Samples were etched in a two-step acid treatment. Surface roughness parameters were quantified under a confocal microscope, topography was studied by scanning electron microscopy, and surface composition was analyzed with energy dispersive X-ray spectroscopy. The results revealed that the two-step acid treatment changes the topography of the β alloy, increases the surface area, and changes the chemical composition of the surface. Two differentiated regions were identified in the Ti35Nb10Ta1.5Fe alloy after the acid-etching process: The α + β region with higher values of mean roughness due to the lower chemical resistance of this region; and the β region with lower values of roughness parameters. PMID:29587427

Synthesis, spectroscopic characterization and structural studies of a new proton transfer (H-bonded) complex of o-phenylenediamine with L-tartaric acid

NASA Astrophysics Data System (ADS)

Khan, Ishaat M.; Ahmad, Afaq

2013-10-01

A proton transfer or H-bonded (CT) complex of o-phenylenediamine (OPD) as donor with L-tartaric acid (TART) as acceptor was synthesized and characterized by spectral techniques such as FTIR, 1H NMR, elemental analysis, TGA-TDA, X-ray crystallography and spectrophotometric studies. The structural investigations exhibit that the cation [OPD+] and anion [TART-] are linked together through strong N+-H⋯O- type hydrogen bonds due to transfer of proton from acceptor to donor. Formed H-bonded complex exhibits well resolved proton transfer bands in the regions where neither donor nor acceptor has any absorption. The stoichiometry of the H-bonded complex (HBC) was found to be 1:1, determined by straight line methods. Spectrophotometric studies have been performed at room temperature and Benesi-Hildebrand equation was used to determine formation constant (KCT), molar extinction coefficient (ɛCT) and also transition energy (ECT) of the H-bonded complex. Spectrophotomeric and crystallographic studies have ascertained the formation of 1:1 H-bonded complex. Thermal analysis (TGA-DTA) was also used to confirm the thermal fragmentation and the stability of the synthesized H-bonded complex.

Drought-responsive WRKY transcription factor genes TaWRKY1 and TaWRKY33 from wheat confer drought and/or heat resistance in Arabidopsis.

PubMed

He, Guan-Hua; Xu, Ji-Yuan; Wang, Yan-Xia; Liu, Jia-Ming; Li, Pan-Song; Chen, Ming; Ma, You-Zhi; Xu, Zhao-Shi

2016-05-23

Drought stress is one of the major causes of crop loss. WRKY transcription factors, as one of the largest transcription factor families, play important roles in regulation of many plant processes, including drought stress response. However, far less information is available on drought-responsive WRKY genes in wheat (Triticum aestivum L.), one of the three staple food crops. Forty eight putative drought-induced WRKY genes were identified from a comparison between de novo transcriptome sequencing data of wheat without or with drought treatment. TaWRKY1 and TaWRKY33 from WRKY Groups III and II, respectively, were selected for further investigation. Subcellular localization assays revealed that TaWRKY1 and TaWRKY33 were localized in the nuclei in wheat mesophyll protoplasts. Various abiotic stress-related cis-acting elements were observed in the promoters of TaWRKY1 and TaWRKY33. Quantitative real-time PCR (qRT-PCR) analysis showed that TaWRKY1 was slightly up-regulated by high-temperature and abscisic acid (ABA), and down-regulated by low-temperature. TaWRKY33 was involved in high responses to high-temperature, low-temperature, ABA and jasmonic acid methylester (MeJA). Overexpression of TaWRKY1 and TaWRKY33 activated several stress-related downstream genes, increased germination rates, and promoted root growth in Arabidopsis under various stresses. TaWRKY33 transgenic Arabidopsis lines showed lower rates of water loss than TaWRKY1 transgenic Arabidopsis lines and wild type plants during dehydration. Most importantly, TaWRKY33 transgenic lines exhibited enhanced tolerance to heat stress. The functional roles highlight the importance of WRKYs in stress response.

Effect of organic acids and marination ingredients on the survival of Campylobacter jejuni on meat.

PubMed

Birk, Tina; Grønlund, Anne Christine; Christensen, Bjarke Bak; Knøchel, Susanne; Lohse, Kristin; Rosenquist, Hanne

2010-02-01

The aim of this study was to determine whether marination of chicken meat in different food ingredients can be used to reduce populations of Campylobacter jejuni. C. jejuni strains were exposed to different organic acids (tartaric, acetic, lactic, malic, and citric acids) and food marinating ingredients at 4 degrees C in broth and on chicken meat. The organic acids (0.5%) reduced populations of C. jejuni in broth (chicken juice and brain heart infusion broth) by 4 to 6 log units (after 24 h); tartaric acid was the most efficient treatment. Large strain variation was observed among 14 C. jejuni isolates inoculated in brain heart infusion broth containing 0.3% tartaric acid. On chicken meat medallions, reductions of C. jejuni were 0.5 to 2 log units when tartaric acid solutions (2, 4, 6, and 10%) were spread onto the meat. Analysis of acidic food ingredient (e.g., vinegar, lemon juice, pomegranate syrup, and soya sauce) revealed that such ingredients reduced counts of C. jejuni by at least 0.8 log units on meat medallions. Three low pH marinades (pH < 3) based on pomegranate syrup, lemon juice, and white wine vinegar were prepared. When applied to whole filets, these marinades resulted in a reduction of approximately 1.2 log units after 3 days of storage. Taste evaluations of chicken meat that had been marinated and then fried were graded positively for flavor and texture. Thus, success was achieved in creating a marinade with an acceptable taste that reduced the counts of C. jejuni.

Wheat TaSP gene improves salt tolerance in transgenic Arabidopsis thaliana.

PubMed

Ma, Xiaoli; Cui, Weina; Liang, Wenji; Huang, Zhanjing

2015-12-01

A novel salt-induced gene with unknown functions was cloned through analysis of gene expression profile of a salt-tolerant wheat mutant RH8706-49 under salt stress. The gene was named Triticum aestivum salt-related protein (TaSP) and deposited in GenBank (Accession No. KF307326). Quantitative polymerase chain reaction (qPCR) results showed that TaSP expression was induced under salt, abscisic acid (ABA), and polyethylene glycol (PEG) stresses. Subcellular localization revealed that TaSP was mainly localized in cell membrane. Overexpression of TaSP in Arabidopsis could improve salt tolerance of 35S::TaSP transgenic Arabidopsis. 35S::TaSP transgenic Arabidopsis lines after salt stress presented better physiological indexes than the control group. In the non-invasive micro-test (NMT), an evident Na(+) excretion was observed at the root tip of salt-stressed 35S::TaSP transgenic Arabidopsis. TaSP promoter was cloned, and its beta-glucuronidase (GUS) activities before and after ABA, salt, cold, heat, and salicylic acid (SA) stresses were determined. Full-length TaSP promoter contained ABA and salt response elements. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Resolution of 1-n-butyl-3-methyl-3-phospholene 1-oxide with TADDOL derivatives and calcium salts of O,O'-Dibenzoyl-(2R,3R)- or O,O'-di-p-toluoyl-(2R,3R)-tartaric acid.

PubMed

Bagi, Péter; Fekete, András; Kállay, Mihály; Hessz, Dóra; Kubinyi, Miklós; Holczbauer, Tamás; Czugler, Mátyás; Fogassy, Elemér; Keglevich, György

2014-03-01

The resolution methods applying (-)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane ("TADDOL"), (-)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol ("spiro-TADDOL"), as well as the acidic and neutral Ca(2+) salts of (-)-O,O'-dibenzoyl- and (-)-O,O'-di-p-toluoyl-(2R,3R)-tartaric acid were extended for the preparation of 1-n-butyl-3-methyl-3-phospholene 1-oxide in optically active form. In one case, the intermediate diastereomeric complex could be identified by single-crystal X-ray analysis. The absolute P-configuration of the enantiomers of the phospholene oxide was also determined by comparing the experimentally obtained and calculated CD spectra. © 2014 Wiley Periodicals, Inc.

Metabolism of hydroxycinnamic acids and esters by Brettanomyces in different red wines

USDA-ARS?s Scientific Manuscript database

Depending on the cultivars and other factors, differing concentrations of hydroxycinnamic acids (caffeic, p-coumaric, and ferulic acids) and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric acid, respectively) are found in red wines. Hydroxycinnamic acids are metabolized by...

21 CFR 184.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium acid tartrate. 184.1077 Section 184.1077... Listing of Specific Substances Affirmed as GRAS § 184.1077 Potassium acid tartrate. (a) Potassium acid tartrate (C4H5KO6, CAS Reg. No. 868-14-4) is the potassium acid salt of l−(+)−tartaric acid and is also...

21 CFR 184.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium acid tartrate. 184.1077 Section 184.1077... GRAS § 184.1077 Potassium acid tartrate. (a) Potassium acid tartrate (C4H5KO6, CAS Reg. No. 868-14-4) is the potassium acid salt of l−(+)−tartaric acid and is also called potassium bitartrate or cream of...

21 CFR 184.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium acid tartrate. 184.1077 Section 184.1077... Listing of Specific Substances Affirmed as GRAS § 184.1077 Potassium acid tartrate. (a) Potassium acid tartrate (C4H5KO6, CAS Reg. No. 868-14-4) is the potassium acid salt of l−(+)−tartaric acid and is also...

The clinical anticalculus efficacy of a tartar control whitening dentifrice for the prevention of supragingival calculus in a three-month study.

PubMed

Sowinski, J; Petrone, D M; Battista, G; Petrone, M E; Crawford, R; Patel, S; DeVizio, W; Chaknis, P; Volpe, A R; Proskin, H M

1999-01-01

The objective of this double-blind clinical study was to compare the effect of a new dentifrice (Colgate Tartar Control Plus Whitening Fluoride Toothpaste) for the prevention of supragingival calculus, with that of a commercially available calculus-inhibiting dentifrice (Crest Tartar Control Toothpaste). The study involved adult male and female subjects who had pre-qualified for participation by developing sufficient supragingival calculus (greater than 7.0 on the Volpe-Manhold Calculus Index) during an eight-week screening period. Subjects received a full oral prophylaxis, and were stratified into two treatment groups balanced for age, sex and qualifying calculus score. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice using a soft-bristled toothbrush. Examinations for dental calculus were performed after twelve weeks' use of the study dentifrices, using the Volpe-Manhold Calculus Index, Fifty-eight (58) subjects complied with the protocol and completed the entire study. The Colgate Tartar Control Plus Whitening group exhibited a statistically significant (p < 0.001) 34.6% reduction in mean calculus score compared to the Crest Tartar Control group.

27 CFR 24.182 - Use of acid to correct natural deficiencies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... acid, fumaric acid, malic acid, lactic acid or tartaric acid, or a combination of two or more of these... citric acid for other fruit (including berries). (d) Other use of acid. A winemaker desiring to use an... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Use of acid to correct...

27 CFR 24.182 - Use of acid to correct natural deficiencies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... acid, fumaric acid, malic acid, lactic acid or tartaric acid, or a combination of two or more of these... citric acid for other fruit (including berries). (d) Other use of acid. A winemaker desiring to use an... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Use of acid to correct...

27 CFR 24.182 - Use of acid to correct natural deficiencies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... acid, fumaric acid, malic acid, lactic acid or tartaric acid, or a combination of two or more of these... citric acid for other fruit (including berries). (d) Other use of acid. A winemaker desiring to use an... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Use of acid to correct...

27 CFR 24.182 - Use of acid to correct natural deficiencies.

Code of Federal Regulations, 2013 CFR

2013-04-01

... acid, fumaric acid, malic acid, lactic acid or tartaric acid, or a combination of two or more of these... citric acid for other fruit (including berries). (d) Other use of acid. A winemaker desiring to use an... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Use of acid to correct...

Metabolism of nonesterified and esterified hydroxycinnamic acids in red wines by Brettanomyces bruxellensis

USDA-ARS?s Scientific Manuscript database

While Brettanomyces can metabolize non–esterified hydroxycinnamic acids found in grape musts/wines (caffeic, p–coumaric, and ferulic acids), it was not known whether this yeast could utilize the corresponding tartaric acid esters (caftaric, p–coutaric, and fertaric acids, respectively). Red wines fr...

Validation of a rapid conductimetric test for the measurement of wine tartaric stability.

PubMed

Bosso, Antonella; Motta, Silvia; Petrozziello, Maurizio; Guaita, Massimo; Asproudi, Andriani; Panero, Loretta

2016-12-01

This work was aimed at optimizing a rapid and reproducible conductivity test for the evaluation of wine tartaric stability, in order to improve the practices for the prevention of tartaric precipitations during bottle aging. The test consists in measuring the drop of conductivity in wines kept under stirring for a fixed time, at low temperature, after the addition of micronized potassium bitartrate crystals (KHT). An experimental design was planned to study three factors affecting the test: temperature, duration and dose of added potassium bitartrate. A standard protocol was defined to produce a micronized potassium bitartrate starting from available commercial products, since the dimensions of the crystals can affect the final conductivity values. After the choice of the best conditions the method was validated. Two different stability thresholds were defined for white wines and for red/rosé wines by comparing the results of the mini-contact test with those of the cold test. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential metabolism of hydroxycinnamic acids by two Brettanomyces bruxellensis strains grown in red wines

USDA-ARS?s Scientific Manuscript database

Hydroxycinnamic acids (caffeic, p-coumaric, and ferulic acids) and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric acids, respectively) are found in red wines in varying concentrations depending on cultivars and other factors. While some Brettanomyces form volatile phenols...

Sol-gel synthesis, phase composition, morphological and structural characterization of Ca10(PO4)6(OH)2: XRD, FTIR, SEM, 3D SEM and solid-state NMR studies

NASA Astrophysics Data System (ADS)

Kareiva, Simonas; Klimavicius, Vytautas; Momot, Aleksandr; Kausteklis, Jonas; Prichodko, Aleksandra; Dagys, Laurynas; Ivanauskas, Feliksas; Sakirzanovas, Simas; Balevicius, Vytautas; Kareiva, Aivaras

2016-09-01

Aqueous sol-gel chemistry route based on ammonium-hydrogen phosphate as the phosphorus precursor, calcium acetate monohydrate as source of calcium ions, and 1,2-ethylendiaminetetraacetic acid (EDTA), or 1,2-diaminocyclohexanetetracetic acid (DCTA), or tartaric acid (TA), or ethylene glycol (EG), or glycerol (GL) as complexing agents have been used to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp). The phase transformations, composition, and structural changes in the polycrystalline samples were studied by infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRD), and scanning electron microscopy (SEM). The local short-range (nano- and mezo-) scale effects in CHAp were studied using solid-state NMR spectroscopy. The spatial 3D data from the SEM images of CHAp samples obtained by TA, EG and GL sol-gel routes were recovered for the first time to our knowledge.

Enhancement of carvedilol solubility by solid dispersion technique using cyclodextrins, water soluble polymers and hydroxyl acid.

PubMed

Yuvaraja, K; Khanam, Jasmina

2014-08-05

Aim of the present work is to enhance aqueous solubility of carvedilol (CV) by solid dispersion technique using wide variety of carriers such as: β-cyclodextrin (βCD), hydroxypropyl-β-cyclodextrin (HPβCD), tartaric acid (TA), polyvinyl pyrrolidone K-30 (PVP K-30) and poloxamer-407 (PLX-407). Various products of 'CV-solid dispersion' had been studied extensively in various pH conditions to check enhancement of solubility and dissolution characteristics of carvedilol. Any physical change upon interaction between CV and carriers was confirmed by instrumental analysis: XRD, DSC, FTIR and SEM. Negative change of Gibb's free energy and complexation constants (Kc, 75-240M(-1), for cyclodextrins and 1111-20,365M(-1), for PVP K-30 and PLX-407) were the evidence of stable nature of the binding between CV and carriers. 'Solubility enhancement factor' of ionized-CV was found high enough (340 times) with HPβCD in presence of TA. TA increases the binding efficiency of cyclodextrin and changing the pH of microenvironment in dissolution medium. In addition, ionization process was used to increase the apparent intrinsic solubility of drug. In vitro, dissolution time of CV was remarkably reduced in the solid dispersion system compared to that of pure drug. This may be attributed to increased wettability, dispersing ability and transformation of crystalline state of drug to amorphous one. Copyright © 2014 Elsevier B.V. All rights reserved.

Production of starch with antioxidative activity by baking starch with organic acids.

PubMed

Miwa, Shoji; Nakamura, Megumi; Okuno, Michiko; Miyazaki, Hisako; Watanabe, Jun; Ishikawa-Takano, Yuko; Miura, Makoto; Takase, Nao; Hayakawa, Sachio; Kobayashi, Shoichi

2011-01-01

A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment.

Novel properties of the wheat aluminum tolerance organic acid transporter (TaALMT1) revealed by electrophysiological characterization in Xenopus Oocytes: functional and structural implications.

PubMed

Piñeros, Miguel A; Cançado, Geraldo M A; Kochian, Leon V

2008-08-01

Many plant species avoid the phytotoxic effects of aluminum (Al) by exuding dicarboxylic and tricarboxylic acids that chelate and immobilize Al(3+) at the root surface, thus preventing it from entering root cells. Several novel genes that encode membrane transporters from the ALMT and MATE families recently were cloned and implicated in mediating the organic acid transport underlying this Al tolerance response. Given our limited understanding of the functional properties of ALMTs, in this study a detailed characterization of the transport properties of TaALMT1 (formerly named ALMT1) from wheat (Triticum aestivum) expressed in Xenopus laevis oocytes was conducted. The electrophysiological findings are as follows. Although the activity of TaALMT1 is highly dependent on the presence of extracellular Al(3+) (K(m1/2) of approximately 5 microm Al(3+) activity), TaALMT1 is functionally active and can mediate ion transport in the absence of extracellular Al(3+). The lack of change in the reversal potential (E(rev)) upon exposure to Al(3+) suggests that the "enhancement" of TaALMT1 malate transport by Al is not due to alteration in the transporter's selectivity properties but is solely due to increases in its anion permeability. The consistent shift in the direction of the E(rev) as the intracellular malate activity increases indicates that TaALMT1 is selective for the transport of malate over other anions. The estimated permeability ratio between malate and chloride varied between 1 and 30. However, the complex behavior of the E(rev) as the extracellular Cl(-) activity was varied indicates that this estimate can only be used as a general guide to understanding the relative affinity of TaALMT1 for malate, representing only an approximation of those expected under physiologically relevant ionic conditions. TaALMT1 can also mediate a large anion influx (i.e. outward currents). TaALMT1 is permeable not only to malate but also to other physiologically relevant anions such as Cl

Synthesis of α-MoO{sub 3} nanoplates using organic aliphatic acids and investigation of sunlight enhanced photodegradation of organic dyes

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

Kumar, V. Vinod; Gayathri, K.; Anthony, Savarimuthu Philip, E-mail: philip@biotech.sastra.edu

Graphical abstract: Thermodynamically stable α-MoO{sub 3} nanoplates and nanorods were synthesized using organic structure controlling agents and demonstrated sun light enhanced photocatalytic degradation of methylene blue (MB) and rhodamine blue (Rh-B) dyes in aqueous solution. - Highlights: • α-MoO{sub 3} hexagonal nanoplates using organic structure controlling agents. • Tunable optical band gap of MoO{sub 3}. • Demonstrated strong sun light mediated enhanced photodegradation of methylene blue and rhodamine blue. • Photodegradation did not use any other external oxidizing agents. - Abstract: Thermodynamically stable α-MoO{sub 3} nanoplates were synthesized using organic aliphatic acids as structure controlling agents and investigated photocatalytic degradationmore » of methylene blue (MB) and rhodamine blue (Rh-B) in presence of sun light. Three different organic aliphatic acids, citric acid (CA), tartaric acid (TA) and ethylene diamine tetra-acetic acid (EDTA), were employed to control morphologies. CA and TA predominantly produced extended hexagonal plates where EDTA gave nanorods as well as nanoplates. PXRD studies confirmed the formation of α-MoO{sub 3} nanoparticles. HR-TEM and FE-SEM reveal the formation of plate morphologies with 20–40 nm thickness, 50–100 nm diameter and 600 nm lengths. The different morphologies of α-MoO{sub 3} nanoparticles lead to the tunable optical band gap between 2.80 and 2.98 eV which was obtained from diffused reflectance spectra (DRS). Interestingly, the synthesized α-MoO{sub 3} nanoplates exhibited strong photocatalytic degradation of MB and Rh-B up to 99% in presence of sun light without using any oxidizing agents.« less

Influence of carboxylic acid type on microstructure and magnetic properties of polymeric complex sol-gel driven NiFe2O4

NASA Astrophysics Data System (ADS)

Hessien, M. M.; Mostafa, Nasser Y.; Abd-Elkader, Omar H.

2016-01-01

Citric, oxalic and tartaric acids were used for synthesis of NiFe2O4 using polymeric complex precursor route. The dry precursor gels were calcined at various temperatures (400-1100 °C) for 2 h. All carboxylic acids produce iron-deficient NiFe2O4 with considerable amount of α-Fe2O3 at 400 °C. Increase in the annealing temperature caused reaction of α-Fe2O3 with iron-deficient ferrite phase. The amount of initially formed α-Fe2O3 is directly correlated with stability constant and inversely correlated with the decomposition temperature of Fe(III) carboxylate precursors. In case of tartaric acid precursor, single phase of the ferrite was obtained at 450 °C. However, in case of oxalic acid and citric acid precursors, single phase ferrite was obtained at 550 °C and 700 °C, respectively. The lattice parameters were increased with increasing annealing temperature and with decreasing the amount of α-Fe2O3. Maximum saturation magnetization (55 emu/g) was achieved using tartaric acid precursor annealed at 1100 °C.

Assessment of iron chelates efficiency for photo-Fenton at neutral pH.

PubMed

De Luca, Antonella; Dantas, Renato F; Esplugas, Santiago

2014-09-15

In this study, homogeneous photo-Fenton like at neutral pH was applied to remove sulfamethoxazole from water. The process was performed using different chelating agents in order to solubilize iron in a neutral water solution. The chelating agents tested were: ethylenediaminetetraacetic acid (EDTA); nitrilotriacetic acid (NTA); oxalic acid (OA) and tartaric acid (TA). The iron leaching was monitored over reaction time to evaluate the chelates stability and their resistance to HO· and UV-A radiation. Chelates of EDTA and NTA presented more stability than OA and TA, which also confirmed their higher efficiency. Total Organic Carbon (TOC) analyses were also performed to evaluate the contribution in terms of solution contamination related to the use of chelating agents. The better properties of biodegradability in respect of EDTA combined with better efficiency in terms of microcontaminant removal and the smallest TOC contribution indicate that NTA could represent a useful option to perform photo-Fenton processes at neutral pH. Copyright © 2014 Elsevier Ltd. All rights reserved.

Organic acids influence iron uptake in the human epithelial cell line Caco-2.

PubMed

Salovaara, Susan; Sandberg, Ann-Sofie; Andlid, Thomas

2002-10-09

It has previously been suggested that organic acids enhance iron absorption. We have studied the effect of nine organic acids on the absorption of Fe(II) and Fe(III) in the human epithelial cell line Caco-2. The effect obtained was dose-dependent, and the greatest increase (43-fold) was observed for tartaric acid (4 mmol/L) on Fe(III) (10 micromol/L). Tartaric, malic, succinic, and fumaric acids enhanced Fe(II) and Fe(III) uptake. Citric and oxalic acid, on the other hand, inhibited Fe(II) uptake but enhanced Fe(III) uptake. Propionic and acetic acid increased the Fe(II) uptake, but had no effect on Fe(III) uptake. Our results show a correlation between absorption pattern and chemical structure; e.g. hydroxyl groups, in addition to carboxyls, were connected with a positive influence. The results may be important for elucidating factors affecting iron bioavailability in the small intestine and for the development of foods with improved iron bioavailability.

Determination of enantiomeric vigabatrin by derivatization with diacetyl-l-tartaric anhydride followed by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry.

PubMed

Zhao, Jing; Shin, Yujin; Jin, Yan; Jeong, Kyung Min; Lee, Jeongmi

2017-01-01

Vigabatrin, one of the most widely used antiepileptic drugs, is marketed and administered as a racemic mixture, while only S-enantiomer is therapeutically effective. In the present study, diacetyl-l-tartaric acid anhydride was used as an inexpensive and effective chiral derivatization reagent to produce tartaric acid monoester derivatives of vigabatrin enantiomers that could be readily resolved by reversed phase chromatography. Derivatization conditions were statistically optimized by response surface methodology, resulting in an optimal reaction temperature of 44°C and an optimal reaction time of 30min. The derivatized diastereomers of vigabatrin and internal standard (gabapentin) were analyzed using ultra-high performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry. For this analysis, an Agilent ZORBAX Rapid Resolution High Definition Eclipse Plus C18 column (100mm×2.1mm, 1.8μm) was employed for chromatographic separation using 10mM ammonium formate (pH 3.0) and methanol as mobile phase at a flow rate of 0.2mLmin -1 . The established method was validated in terms of specificity, linearity, precision, accuracy, dilution integrity, recovery, matrix effect, stability, and incurred sample reanalysis. It was linear over a range of 0.25-100.0mgL -1 for both S- and R-enantiomers (R 2 ≥0.9987 for both). Intra- and inter-day precisions and accuracies were within acceptable ranges. The method was successfully applied to determine the levels of vigabatrin enantiomers in mouse serum after administration of vigabatrin racemate. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel Properties of the Wheat Aluminum Tolerance Organic Acid Transporter (TaALMT1) Revealed by Electrophysiological Characterization in Xenopus Oocytes: Functional and Structural Implications1[OA

PubMed Central

Piñeros, Miguel A.; Cançado, Geraldo M.A.; Kochian, Leon V.

2008-01-01

Many plant species avoid the phytotoxic effects of aluminum (Al) by exuding dicarboxylic and tricarboxylic acids that chelate and immobilize Al3+ at the root surface, thus preventing it from entering root cells. Several novel genes that encode membrane transporters from the ALMT and MATE families recently were cloned and implicated in mediating the organic acid transport underlying this Al tolerance response. Given our limited understanding of the functional properties of ALMTs, in this study a detailed characterization of the transport properties of TaALMT1 (formerly named ALMT1) from wheat (Triticum aestivum) expressed in Xenopus laevis oocytes was conducted. The electrophysiological findings are as follows. Although the activity of TaALMT1 is highly dependent on the presence of extracellular Al3+ (Km1/2 of approximately 5 μm Al3+ activity), TaALMT1 is functionally active and can mediate ion transport in the absence of extracellular Al3+. The lack of change in the reversal potential (Erev) upon exposure to Al3+ suggests that the “enhancement” of TaALMT1 malate transport by Al is not due to alteration in the transporter's selectivity properties but is solely due to increases in its anion permeability. The consistent shift in the direction of the Erev as the intracellular malate activity increases indicates that TaALMT1 is selective for the transport of malate over other anions. The estimated permeability ratio between malate and chloride varied between 1 and 30. However, the complex behavior of the Erev as the extracellular Cl− activity was varied indicates that this estimate can only be used as a general guide to understanding the relative affinity of TaALMT1 for malate, representing only an approximation of those expected under physiologically relevant ionic conditions. TaALMT1 can also mediate a large anion influx (i.e. outward currents). TaALMT1 is permeable not only to malate but also to other physiologically relevant anions such as Cl−, NO3−, and

Characterization of metabolic network of oxalic acid biosynthesis through RNA seq data analysis of developing spikes of finger millet (Eleusine coracana): Deciphering the role of key genes involved in oxalate formation in relation to grain calcium accumulation.

PubMed

Akbar, Naved; Gupta, Supriya; Tiwari, Apoorv; Singh, K P; Kumar, Anil

2018-04-05

In the present study, we identified seven major genes of oxalic acid biosynthesis pathway (SGAT, GGAT, ICL, GLO, MHAR, APO and OXO) from developing spike transcriptome of finger millet using rice as a reference. Sequence alignment of identified genes showed high similarity with their respective homolog in rice except for OXO and GLO. Transcript abundance (FPKM) reflects the higher accumulation of identified genes in GP-1 (low calcium genotype) as compared to GP-45 (high calcium genotype) which was further confirmed by qRT-PCR analysis, indicating differential oxalate formation in both genotypes. Determination of oxalic acid and tartaric acid content in developing spikes explain that higher oxalic acid content in GP-1 however, tartaric acid content was more in GP-45. Higher calcium content in GP-45 and lower oxalate accumulation may be due to the diversion of more ascorbic acid into tartaric acid and may correspond to less formation of calcium oxalate. Our results suggest that more than one pathway for oxalic acid biosynthesis might be present in finger millet with probable predominance of ascorbate-tartarate pathway rather than glyoxalate-oxalate conversion. Thus, finger millet can be use as an excellent model system for understanding more specific role of nutrients-antinutrients interactions, as evident from the present study. Copyright © 2018 Elsevier B.V. All rights reserved.

Chiral SiO2 and Ag@SiO2 Materials Templated by Complexes Consisting of Comblike Polyethyleneimine and Tartaric Acid.

PubMed

Yao, Dong-Dong; Murata, Hiroki; Tsunega, Seiji; Jin, Ren-Hua

2015-10-26

A facile avenue to fabricate micrometer-sized chiral (L-, D-) and meso-like (dl-) SiO2 materials with unique structures by using crystalline complexes (cPEI/tart), composed of comblike polyethyleneimine (cPEI) and L-, D-, or dl-tartaric acid, respectively, as catalytic templates is reported. Interestingly, both chiral crystalline complexes appeared as regularly left- and right-twisted bundle structures about 10 μm in length and about 5 μm in diameter, whereas the dl-form occurred as circular structures with about 10 μm diameter. Subsequently, SiO2 @cPEI/tart hybrids with high silica content (>55.0 wt %) were prepared by stirring a mixture containing tetramethoxysilane (TMOS) and the aggregates of the crystalline complexes in water. The chiral SiO2 hybrids and calcined chiral SiO2 showed very strong CD signals and a nanofiber-based morphology on their surface, whereas dl-SiO2 showed no CD activity and a nanosheet-packed disklike shape. Furthermore, metallic silver nanoparticles (Ag NPs) were encapsulated in each silica hybrid to obtain chiral (D and L forms) and meso-like (dl form) Ag@SiO2 composites. Also, the reaction between L-cysteine (Lcys) and these Ag@SiO2 composites was preliminarily investigated. Only chiral L- and D-Ag@SiO2 composites promoted the reaction between Lcys and Ag NPs to produce a molecular [Ag-Lcys]n complex with remarkable exciton chirality, whereas the reaction hardly occurred in the case of meso-like (dl-) Ag@SiO2 composite. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Biopolymer Composite Films Using a Microfluidization Technique for Carboxymethylcellulose and Apple Skin Particles

PubMed Central

Choi, Inyoung; Chang, Yoonjee; Shin, So-Hyang; Joo, Eunmi; Song, Hyun Ju; Eom, Haeyoung; Han, Jaejoon

2017-01-01

Biopolymer films based on apple skin powder (ASP) and carboxymethylcellulose (CMC) were developed with the addition of apple skin extract (ASE) and tartaric acid (TA). ASP/CMC composite films were prepared by mixing CMC with ASP solution using a microfluidization technique to reduce particle size. Then, various concentrations of ASE and TA were incorporated into the film solution as an antioxidant and an antimicrobial agent, respectively. Fourier transform infrared (FTIR), optical, mechanical, water barrier, and solubility properties of the developed films were then evaluated to determine the effects of ASE and TA on physicochemical properties. The films were also analyzed for antioxidant effect on 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica, and Shigella flexneri. From the results, the ASP/CMC film containing ASE and TA was revealed to enhance the mechanical, water barrier, and solubility properties. Moreover, it showed the additional antioxidant and antimicrobial properties for application as an active packaging film. PMID:28617325

Transgenic barley (Hordeum vulgare L.) expressing the wheat aluminium resistance gene (TaALMT1) shows enhanced phosphorus nutrition and grain production when grown on an acid soil.

PubMed

Delhaize, Emmanuel; Taylor, Phillip; Hocking, Peter J; Simpson, Richard J; Ryan, Peter R; Richardson, Alan E

2009-06-01

Barley (Hordeum vulgare L.), genetically modified with the Al(3+) resistance gene of wheat (TaALMT1), was compared with a non-transformed sibling line when grown on an acidic and highly phosphate-fixing ferrosol supplied with a range of phosphorus concentrations. In short-term pot trials (26 days), transgenic barley expressing TaALMT1 (GP-ALMT1) was more efficient than a non-transformed sibling line (GP) at taking up phosphorus on acid soil, but the genotypes did not differ when the soil was limed. Differences in phosphorus uptake efficiency on acid soil could be attributed not only to the differential effects of aluminium toxicity on root growth between the genotypes, but also to differences in phosphorus uptake per unit root length. Although GP-ALMT1 out-performed GP on acid soil, it was still not as efficient at taking up phosphorus as plants grown on limed soil. GP-ALMT1 plants grown in acid soil possessed substantially smaller rhizosheaths than those grown in limed soil, suggesting that root hairs were shorter. This is a probable reason for the lower phosphorus uptake efficiency. When grown to maturity in large pots, GP-ALMT1 plants produced more than twice the grain as GP plants grown on acid soil and 80% of the grain produced by limed controls. Expression of TaALMT1 in barley was not associated with a penalty in either total shoot or grain production in the absence of Al(3+), with both genotypes showing equivalent yields in limed soil. These findings demonstrate that an important crop species can be genetically engineered to successfully increase grain production on an acid soil.

Crystal growth and physical characterization of picolinic acid cocrystallized with dicarboxylic acids

NASA Astrophysics Data System (ADS)

Somphon, Weenawan; Haller, Kenneth J.

2013-01-01

Pharmaceutical cocrystals are multicomponent materials containing an active pharmaceutical ingredient with another component in well-defined stoichiometry within the same unit cell. Such cocrystals are important in drug design, particularly for improving physicochemical properties such as solubility, bioavailability, or chemical stability. Picolinic acid is an endogenous metabolite of tryptophan and is widely used for neuroprotective, immunological, and anti-proliferative effects within the body. In this paper we present cocrystallization experiments of a series of dicarboxylic acids, oxalic acid, succinic acid, DL-tartaric acid, pimelic acid, and phthalic acid, with picolinic acid. Characterization by FT-IR and Raman spectroscopy, DSC and TG/DTG analysis, and X-ray powder diffraction show that new compounds are formed, including a 1:1 picolinium tartrate monohydrate, a 2:1 monohydrate adduct of picolinic acid and oxalic acid, and a 2:1 picolinic acid-succinic acid monohydrate cocrystal.

Two members of TaRLK family confer powdery mildew resistance in common wheat.

PubMed

Chen, Tingting; Xiao, Jin; Xu, Jun; Wan, Wentao; Qin, Bi; Cao, Aizhong; Chen, Wei; Xing, Liping; Du, Chen; Gao, Xiquan; Zhang, Shouzhong; Zhang, Ruiqi; Shen, Wenbiao; Wang, Haiyan; Wang, Xiue

2016-01-25

Powdery mildew, caused by Blumeria graminearum f.sp. tritici (Bgt), is one of the most severe fungal diseases of wheat. The exploration and utilization of new gene resources is the most effective approach for the powdery mildew control. We report the cloning and functional analysis of two wheat LRR-RLKs from T. aestivum c.v. Prins- T. timopheevii introgression line IGV1-465, named TaRLK1 and TaRLK2, which play positive roles in regulating powdery mildew resistance in wheat. The two LRR-RLKs contain an ORF of 3,045 nucleotides, encoding a peptide of 1014 amino acids, with seven amino acids difference. Their predicted proteins possess a signal peptide, several LRRs, a trans-membrane domain, and a Ser/Thr protein kinase domain. In response to Bgt infection, the TaRLK1/2 expression is up-regulated in a developmental-stage-dependent manner. Single-cell transient over-expression and gene-silencing assays indicate that both genes positively regulate the resistance to mixed Bgt inoculums. Transgenic lines over-expressing TaRLK1 or TaRLK2 in a moderate powdery mildew susceptible wheat variety Yangmai 158 led to significantly enhanced powdery mildew resistance. Exogenous applied salicylic acid (SA) or hydrogen peroxide (H2O2) induced the expression of both genes, and H2O2 had a higher accumulation at the Bgt penetration sites in RLK over-expression transgenic plants, suggesting a possible involvement of SA and altered ROS homeostasis in the defense response to Bgt infection. The two LRR-RLKs are located in the long arm of wheat chromosome 2B, in which the powdery mildew resistance gene Pm6 is located, but in different regions. Two members of TaRLK family were cloned from IGV1-465. TaRLK1 and TaRLK2 contribute to powdery mildew resistance of wheat, providing new resistance gene resources for wheat breeding.

TaCHP: a wheat zinc finger protein gene down-regulated by abscisic acid and salinity stress plays a positive role in stress tolerance.

PubMed

Li, Cuiling; Lv, Jian; Zhao, Xin; Ai, Xinghui; Zhu, Xinlei; Wang, Mengcheng; Zhao, Shuangyi; Xia, Guangmin

2010-09-01

The plant response to abiotic stresses involves both abscisic acid (ABA)-dependent and ABA-independent signaling pathways. Here we describe TaCHP, a CHP-rich (for cysteine, histidine, and proline rich) zinc finger protein family gene extracted from bread wheat (Triticum aestivum), is differentially expressed during abiotic stress between the salinity-sensitive cultivar Jinan 177 and its tolerant somatic hybrid introgression cultivar Shanrong No.3. TaCHP expressed in the roots of seedlings at the three-leaf stage, and the transcript localized within the cells of the root tip cortex and meristem. TaCHP transcript abundance was higher in Shanrong No.3 than in Jinan 177, but was reduced by the imposition of salinity or drought stress, as well as by the exogenous supply of ABA. When JN17, a salinity hypersensitive wheat cultivar, was engineered to overexpress TaCHP, its performance in the face of salinity stress was improved, and the ectopic expression of TaCHP in Arabidopsis (Arabidopsis thaliana) also improved the ability of salt tolerance. The expression level of a number of stress reporter genes (AtCBF3, AtDREB2A, AtABI2, and AtABI1) was raised in the transgenic lines in the presence of salinity stress, while that of AtMYB15, AtABA2, and AtAAO3 was reduced in its absence. The presence in the upstream region of the TaCHP open reading frame of the cis-elements ABRE, MYBRS, and MYCRS suggests that it is a component of the ABA-dependent and -independent signaling pathways involved in the plant response to abiotic stress. We suggest that TaCHP enhances stress tolerance via the promotion of CBF3 and DREB2A expression.

TaRAR1 and TaSGT1 associate with TaHsp90 to function in bread wheat (Triticum aestivum L.) seedling growth and stripe rust resistance.

PubMed

Wang, Guan-Feng; Fan, Renchun; Wang, Xianping; Wang, Daowen; Zhang, Xiangqi

2015-04-01

RAR1 and SGT1 are important co-chaperones of Hsp90. We previously showed that TaHsp90.1 is required for wheat seedling growth, and that TaHsp90.2 and TaHsp90.3 are essential for resistance (R) gene mediated resistance to stripe rust fungus. Here, we report the characterization of TaRAR1 and TaSGT1 genes in bread wheat. TaRAR1 and TaSGT1 each had three homoeologs, which were located on wheat groups 2 and 3 chromosomes, respectively. Strong inhibition of seedling growth was observed after silencing TaSGT1 but not TaRAR1. In contrast, decreasing the expression of TaRAR1 or TaSGT1 could all compromise R gene mediated resistance to stripe rust fungus infection. Protein-protein interactions were found among TaRAR1, TaSGT1 and TaHsp90. The N-terminus of TaHsp90, the CHORD-I and CHORD-II domains of TaRAR1 and the CS domain of TaSGT1 may be instrumental for the interactions among the three proteins. Based on this work and our previous study on TaHsp90, we speculate that the TaSGT1-TaHsp90.1 interaction is important for maintaining bread wheat seedling growth. The TaRAR1-TaSGT1-TaHsp90.2 and TaRAR1-TaSGT1-TaHsp90.3 interactions are involved in controlling the resistance to stripe rust disease. The new information obtained here should aid further functional investigations of TaRAR1-TaSGT1-TaHsp90 complexes in regulating bread wheat growth and disease resistance.

Effects of surfactants on low-molecular-weight organic acids to wash soil zinc.

PubMed

Chen, Yue; Zhang, Shirong; Xu, Xiaoxun; Yao, Ping; Li, Ting; Wang, Guiyin; Gong, Guoshu; Li, Yun; Deng, Ouping

2016-03-01

Soil washing is an effective approach to the removal of heavy metals from contaminated soil. In this study, the effects of the surfactants sodium dodecyl sulfate, Triton X-100, and non-ionic polyacrylamide (NPAM) on oxalic acid, tartaric acid, and citric acid used to remove zinc from contaminated soils were investigated. The Zn removal efficiencies of all washing solutions showed a logarithmic increase with acid concentrations from 0.5 to 10.0 g/L, while they decreased as pH increased from 4 to 9. Increasing the reaction time enhanced the effects of surfactants on Zn removal efficiencies by the acids during washing and significantly (P < 0.05) improved the removal under some mixed cases. Oxalic acid suffered antagonistic effects from the three surfactants and seriously damaged soil nutrients during the removal of soil Zn. Notably, the three surfactants caused synergistic effects on tartaric and citric acid during washing, with NPAM leading to an increase in Zn removal by 5.0 g/L citric acid of 10.60 % (P < 0.05) within 2 h. NPAM also alleviated the loss of cation exchange capacity of washed soils and obviously improved soil nitrogen concentrations. Overall, combining citric acid with NPAM offers a promising approach to the removal of zinc from contaminated soil.

The Electrochemical Behavior of Mo-Ta Alloy in Phosphoric Acid Solution for TFT-LCD Application.

PubMed

Lee, Sang-Hyuk; Kim, Byoung O; Seo, Jong Hyun

2015-10-01

Molybdenum-tantalum alloy thin film is a suitable material for the higher corrosion resistance and low resistivity for gate and data metal lines. In this study, Mo-Ta alloy thin films were prepared by using a DC magnetron co-sputtering system on a glass substrate. An abrupt increase in the etching rates of low Mo-Ta alloys was observed. From the observed impedance analysis, the defect densities in the MoTa oxide films increased from 5.4 x 10(21) (cm(-3)) to 8.02 x 10(21) (cm(-3)) up to the 6 at% of tantalum level; and above the 6 at% of tantalum level, the defect densities decreased. This electrochemical behavior is explained by the mechanical instability of the MoTa oxide film.

Differential effect of buffering agents on the crystallization of gemcitabine hydrochloride in frozen solutions.

PubMed

Patel, Mehulkumar; Munjal, Bhushan; Bansal, Arvind K

2014-08-25

The purpose of this study was to evaluate the differential effect of buffering agents on the crystallization of gemcitabine hydrochloride (GHCl) in frozen solutions. Four buffering agents, viz. citric acid (CA), malic acid (MA), succinic acid (SA) and tartaric acid (TA) were selected and their effect on GHCl crystallization was monitored using standard DSC and low temperature XRD. Onset of GHCl crystallization during heating run in DSC was measured to compare the differential effect of buffering agents. Glass transition temperature (Tg'), unfrozen water content in the freeze concentrate and crystallization propensity of the buffering agents was also determined for mechanistic understanding of the underlying effects. CA and MA inhibited while SA facilitated crystallization of GHCl even at 25 mM concentration. Increasing the concentration enhanced their effect. However, TA inhibited GHCl crystallization at concentrations <100mM and facilitated it at concentrations ≥100 mM. Lyophilization of GHCl with either SA or TA yielded elegant cakes, while CA and MA caused collapse. Tg' failed to explain the inhibitory effects of CA, MA and TA as all buffering agents lowered the Tg' of the system. Differential effect of buffering agents on GHCl crystallization could be explained by consideration of two opposing factors: (i) their own crystallization tendency and (ii) unfrozen water content in the freeze concentrate. In conclusion, it was established that API crystallization in frozen solution is affected by the type and concentration of the buffering agents. Copyright © 2014 Elsevier B.V. All rights reserved.

Semimicrodetermination of tantalum with selenous acid

USGS Publications Warehouse

Grimaldi, F.S.; Schnepfe, M.M.

1958-01-01

Tantalum is separated and determined gravimetrically by precipitation with selenous acid from a highly acidic solution containing oxalic and tartaric acids. The method is selective for the determination of up to 30 mg. of tantalum pentoxide, and tolerates relatively large amounts of scandium, yttrium, cerium, titanium, zirconium, thorium, vanadium, niobium, molybdenum, tungsten, uranium, iron, aluminum, gallium, tin, lead, antimony, and bismuth. The separation of tantalum from niobium and titanium is not strictly quantitative, and correction is made colorimetrically for the small amounts of niobium and titanium co-precipitating with the tantalum. The method was applied to the determination of tantalum in tantaloniobate ores.

Evolutionary Optimization of a Charge Transfer Ionic Potential Model for Ta/Ta-Oxide Heterointerfaces

DOE PAGES

Sasikumar, Kiran; Narayanan, Badri; Cherukara, Mathew; ...

2017-03-19

Heterostructures of tantalum and its oxide are of tremendous technological interest for a myriad of technological applications, including electronics, thermal management, catalysis and biochemistry. In particular, local oxygen stoichiometry variation in TaO x memristors comprising of thermodynamically stable metallic (Ta) and insulating oxide (Ta 2O 5) have been shown to result in fast switching on the subnanosecond timescale over a billion cycles. This rapid switching opens up the potential for advanced functional platforms such as stateful logic operations and neuromorphic computation. Despite its broad importance, an atomistic scale understanding of oxygen stoichiometry variation across Ta/TaO x heterointerfaces, such as duringmore » early stages of oxidation and oxide growth, is not well understood. This is mainly due to the lack of a unified interatomic potential model for tantalum oxides that can accurately describe metallic (Ta), ionic (TaO x) as well as mixed (Ta/TaO x interfaces) bonding environments simultaneously. To address this challenge, we introduce a Charge Transfer Ionic Potential (CTIP) model for Ta/Ta-oxide system by training against lattice parameters, cohesive energies, equations of state (EOS), elastic properties, and surface energies of the various experimentally observed Ta 2O 5 polymorphs (hexagonal, orthorhombic and monoclinic) obtained from density functional theory (DFT) calculations. The best CTIP parameters are determined by employing a global optimization scheme driven by genetic algorithms followed by local Simplex optimization. Our newly developed CTIP potential accurately predicts structure, thermodynamics, energetic ordering of polymorphs, as well as elastic and surface properties of both Ta and Ta 2O 5, in excellent agreement with DFT calculations and experiments. We employ our newly parameterized CTIP potential to investigate the early stages of oxidation and atomic scale mechanisms associated with oxide growth on Ta surface

Direct evidence on Ta-Metal Phases Igniting Resistive Switching in TaOx Thin Film

PubMed Central

Kyu Yang, Min; Ju, Hyunsu; Hwan Kim, Gun; Lee, Jeon-Kook; Ryu, Han-Cheol

2015-01-01

A Ta/TaOx/Pt stacked capacitor-like device for resistive switching was fabricated and examined. The tested device demonstrated stable resistive switching characteristics including uniform distribution of resistive switching operational parameters, highly promising endurance, and retention properties. To reveal the resistive switching mechanism of the device, micro structure analysis using high-resolution transmission electron microscope (HR-TEM) was performed. From the observation results, two different phases of Ta-metal clusters of cubic α-Ta and tetragonal β-Ta were founded in the amorphous TaOx mother-matrix after the device was switched from high resistance state (HRS) to low resistance state (LRS) by externally applied voltage bias. The observed Ta metal clusters unveiled the origin of the electric conduction paths in the TaOx thin film at the LRS. PMID:26365532

Direct evidence on Ta-Metal Phases Igniting Resistive Switching in TaOx Thin Film

NASA Astrophysics Data System (ADS)

Kyu Yang, Min; Ju, Hyunsu; Hwan Kim, Gun; Lee, Jeon-Kook; Ryu, Han-Cheol

2015-09-01

A Ta/TaOx/Pt stacked capacitor-like device for resistive switching was fabricated and examined. The tested device demonstrated stable resistive switching characteristics including uniform distribution of resistive switching operational parameters, highly promising endurance, and retention properties. To reveal the resistive switching mechanism of the device, micro structure analysis using high-resolution transmission electron microscope (HR-TEM) was performed. From the observation results, two different phases of Ta-metal clusters of cubic α-Ta and tetragonal β-Ta were founded in the amorphous TaOx mother-matrix after the device was switched from high resistance state (HRS) to low resistance state (LRS) by externally applied voltage bias. The observed Ta metal clusters unveiled the origin of the electric conduction paths in the TaOx thin film at the LRS.

TaMAPK4 Acts as a Positive Regulator in Defense of Wheat Stripe-Rust Infection

PubMed Central

Wang, Bing; Song, Na; Zhang, Qiong; Wang, Ning; Kang, Zhensheng

2018-01-01

Highly conserved mitogen-activated protein kinase (MAPK) cascades regulate numerous plant processes, including hormonal responses, stress, and innate immunity. In this research, TaMAPK4 was predicted to be a target of tae-miR164. We verified the binding and suppression of TaMAPK4 by co-expression in Nicotiana benthamiana. Moreover, we found TaMAPK4 was localized in the cytoplasm and nucleus using transient expression analyses. TaMAPK4 transcripts increased following salicylic acid (SA) treatment and when host plants were infected with an avirulent race of the stripe-rust pathogen. Silencing of TaMAPK4 by virus-induced gene silencing permitted increased colonization by the avirulent pathogen race. Detailed histological results showed increased Puccinia striiformis (Pst) hyphal length, hyphal branches, and infection uredinial size compared to the non-silenced control. SA accumulation and the transcript levels of TaPR1, TaPR2, and TaPR5 were significantly down-regulated in TaMAPK4 knockdown plants. Overall, these results suggest that TaMAPK4 plays an important role in signaling during the wheat-Pst interaction. These results present new insights into MAPK signaling in wheat defense to rust pathogen. PMID:29527215

Synthesis, processing and properties of TaC-TaB2-C Ceramics

DTIC Science & Technology

2010-01-01

powder used. • A very important conclusion from the present study is that the grain size of nominally pure TaC ceramics is a strong function of carbon...ceramics at temperatures as low as 1500 ◦C. The grain size of nominally pure TaC ceramics was a strong function of carbon stoichiometry. Enhanced grain...evaluate the properties of ceramics in the TaC–TaB2–C system. Published by Elsevier Ltd. Keywords: A . Sintering; B. Microstructure; D. Carbides; D. Carbon

Low temperature and binding to food components inhibit the antibacterial activity of carvacrol against Listeria monocytogenes in steak tartare.

PubMed

Veldhuizen, Edwin J A; Creutzberg, T Olaf; Burt, Sara A; Haagsman, Henk P

2007-09-01

Carvacrol is a major component of thyme and oregano essential oils and has potential uses as a food preservative. The effect of carvacrol on the growth of Listeria monocytogenes was investigated in vitro and in steak tartare. Carvacrol had strong antilisterial activity in growth medium (MIC = 1.6 mM), but no effect was observed when carvacrol was tested in steak tartare. There were two reasons for this reduced activity: the antilisterial activity of carvacrol was strongly reduced at lower temperatures (10 versus 30 degrees C), and the presence of food components interfered with the activity of carvacrol. Both bovine serum albumin and egg yolk inhibited carvacrol activity at > 0.2% (wt/vol) in growth medium. For the first time, carvacrol was found to bind to albumin, suggesting that the reduced antilisterial activity of carvacrol in foods such as dairy products and uncooked meats is the result of fewer free unbound carvacrol molecules available to interact with bacteria.

75 FR 43556 - TA-W-73,381, MT Rail Link, Inc., Missoula, MT; TA-W-73,381A, Billings, MT; TA-W-73,381B, Laurel...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-26

... DEPARTMENT OF LABOR Employment and Training Administration TA-W-73,381, MT Rail Link, Inc., Missoula, MT; TA-W-73,381A, Billings, MT; TA-W-73,381B, Laurel, MT; TA-W-73,381C, Livingston, MT; TA-W-73... Helena, Montana. The amended notice applicable to TA-W-73,381 is hereby issued as follows: All workers of...

A CBL-Interacting Protein Kinase TaCIPK2 Confers Drought Tolerance in Transgenic Tobacco Plants through Regulating the Stomatal Movement.

PubMed

Wang, Yan; Sun, Tao; Li, Tingting; Wang, Meng; Yang, Guangxiao; He, Guangyuan

2016-01-01

In plants, the CBL-CIPK signaling pathways play key roles in the response to abiotic stresses. However, functional studies of CIPKs in the important staple crop wheat are very rare. In this study, we identified a CIPK gene from wheat, designated TaCIPK2. Expression analysis results showed that TaCIPK2 could be up-regulated in wheat leaves by polyethylene glycol, abscisic acid and H2O2 treatments. Subcellular localization analyses revealed that TaCIPK2 was present in whole wheat epidermal cells. A yeast two-hybrid assay indicated that TaCIPK2 interacted with TaCBL1, 2, 3 and 4 in vitro. Transgenic tobacco plants over-expressing TaCIPK2 exhibited increased drought tolerance, indicated by a larger proportion of green cotyledons and higher survival rates under the osmotic and drought stress conditions compared with control plants. Additionally, physiological index analyses revealed that the transgenic tobacco plants had lower water loss rates and ion leakage, accumulated less malondialdehyde and H2O2, and had higher catalase and superoxide dismutase activities than the control plants. The transgenic plants also exhibited faster stomatal closure following exposure to osmotic stress conditions. The seed germination rates and stomatal aperture of TaCIPK2-overexpressing tobacco plants decreased after exogenous abscisic acid treatment was applied, implying that the transgenic tobacco plants were more sensitive to exogenous abscisic acid than the control plants. Our results indicate that TaCIPK2 plays a positive regulatory role in drought stress responses in transgenic tobacco plants.

Escherichia coli O157:H7 Outbreak Associated with the Consumption of Beef and Veal Tartares in the Province of Quebec, Canada, in 2013.

PubMed

Gaulin, Colette; Ramsay, Danielle; Catford, Angela; Bekal, Sadjia

2015-07-01

An Escherichia coli O157:H7 outbreak occurred in 2013 that was associated with the consumption of beef and veal tartares in the province of Quebec. This report describes the results of the ensuing investigation. As the outbreak was identified, all individuals in the province of Quebec affected with the same strain of E. coli O157:H7 as defined by pulsed-field gel electrophoresis were interviewed using a standardized questionnaire. Cases reported from other provinces in Canada were interviewed by their public health authorities and the results were reported to the Quebec public health authorities. Microbiological and environmental investigations were conducted by the Sous-ministériat à la santé animale et à l'inspection des aliments du Ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec, by the Ville de Montréal's Food Inspection Branch, and by the Canadian Food Inspection Agency at the restaurants, suppliers, and slaughterhouses identified. In total, seven individuals in three different Canadian provinces became ill following infection with the same outbreak strain of E. coli O157:H7. Two cases were hospitalized and one had severe hemolytic uremic syndrome. No deaths were reported. Two restaurant locations serving different tartare meals including, beef, veal, salmon, tuna, and duck were identified as potential sources of the outbreak. No deficiencies at the restaurant locations were observed during inspections by food inspectors. The risk of consuming tartare can be lowered when basic hygienic rules are followed, temperature is strictly controlled, and fresh meat is used. However, even if handling, chopping, and temperature control during storage of the meat are considered adequate, tartare is a raw product and the risk of contamination is present. Consumers should be advised that consuming this product can lead to serious illness.

Thoron-meso-tartaric acid system for determination of thorium

USGS Publications Warehouse

Fletcher, M.H.; Grimaldi, F.S.; Jenkins, L.B.

1957-01-01

In the spectrophotometric determination of thorium with thoron, mesotartaric acid is used as a masking reagent for zirconium. The effects of different experimental variables such as the concentrations of the reagents, time, and temperature, and the behavior of 35 ions which might be present in thorium ores are discussed. A dilution procedure is given for the direct determination of thorium in zircon (ZrSiO4) that is also generally applicable to other materials.

Acidic and basic solutions dissolve protein plugs made of lithostathine complicating choledochal cyst/pancreaticobiliary maljunction.

PubMed

Kaneko, Kenitiro; Ono, Yasuyuki; Tainaka, Takahisa; Sumida, Wataru; Ando, Hisami

2009-07-01

Symptoms of choledochal cysts are caused by protein plugs made of lithostathine, which block the long common channel and increase pancreaticobiliary ductal pressure. Agents that dissolve protein plugs can provide relief from or prevent symptoms. In the present study, drugs reportedly effective for pancreatic and biliary stones were used in dissolution tests. Protein plugs were obtained from choledochal cysts during surgery in two children (5- and 6-year-old girls). Plugs approximately 2 mm in diameter were immersed in citric acid, tartaric acid, dimethadione, bromhexine, dehydrocholic acid, sodium citrate, hydrochloric acid, and sodium hydroxide solutions under observation with a digital microscope. The pH of each solution was measured using a pH meter. Plugs dissolved in citric acid (5.2 mM; pH 2.64), tartaric acid (6.7 mM; pH 2.51), dimethadione (75 mM; pH 3.70), hydrochloric acid (0.5 mM; pH 3.13), and sodium hydroxide (75 mM; pH 12.75) solutions. Plugs did not dissolve in dimethadione (7.5 mM; pH 4.31), bromhexine (0.1%; pH 4.68), dehydrocholic acid (5%; pH 7.45), and sodium citrate (75 mM; pH 7.23) solutions. Protein plugs in choledochal cysts are dissolved in acidic and basic solutions, which may eliminate longitudinal electrostatic interactions of the lithostathine protofibrils.

High-pressure phases of Weyl semimetals NbP, NbAs, TaP, and TaAs

NASA Astrophysics Data System (ADS)

Guo, ZhaoPeng; Lu, PengChao; Chen, Tong; Wu, JueFei; Sun, Jian; Xing, DingYu

2018-03-01

In this study, we used the crystal structure search method and first-principles calculations to systematically explore the highpressure phase diagrams of the TaAs family (NbP, NbAs, TaP, and TaAs). Our calculation results show that NbAs and TaAs have similar phase diagrams, the same structural phase transition sequence I41 md→ P6¯ m2→ P21/ c→ Pm3¯ m, and slightly different transition pressures. The phase transition sequence of NbP and TaP differs somewhat from that of NbAs and TaAs, in which new structures emerge, such as the Cmcm structure in NbP and the Pmmn structure in TaP. Interestingly, we found that in the electronic structure of the high-pressure phase P6¯ m2-NbAs, there are coexistingWeyl points and triple degenerate points, similar to those found in high-pressure P6¯ m2-TaAs.

A study of nitrogen behavior in the formation of Ta/TaN and Ti/TaN alloyed metal electrodes on SiO2 and HfO2 dielectrics

NASA Astrophysics Data System (ADS)

Gassilloud, R.; Maunoury, C.; Leroux, C.; Piallat, F.; Saidi, B.; Martin, F.; Maitrejean, S.

2014-04-01

We studied Ta, TaN, and sub-stoichiometric TaNx electrodes (obtained by nitrogen redistribution in Ta/TaN or Ti/TaN bilayers) deposited on thermal SiO2 and HfO2/IL (0.8 nm SiO2 IL, i.e., interlayer) stacks. Effective work-functions (WF) were extracted on MOS capacitor structures on SiO2 bevelled insulator of 4.2 eV for pure Ta, 4.6 eV for TaN, and 4.3 eV for sub-stoichiometric TaNx. This intermediate WF value is explained by TaN nitrogen redistribution with reactive Ta or Ti elements shifting the gate work-function toward the Si conduction band. The same electrodes deposited on an HfO2/IL dielectric showed different behavior: First, the Ta/HfO2/IL stack shows a +200 meV WF increase (towards the Si valence band) compared to the SiO2 dielectric stack. This increase is explained by the well-known HfO2/IL dipole formation. Second, in contrast to electrodes deposited on SiO2, sub-stoichiometric TaNx/HfO2 is found to have a lower WF (4.3 eV), than pure Ta on HfO2 (4.4 eV). This inversion in work-function behavior measured on SiO2 vs. HfO2 is explained by the nitrogen redistribution in Ta/TaN bilayer together with diffusion of nitrogen through the HfO2 layer, leading to Si-N formation which prevents dipole formation at the HfO2/IL interface.

78 FR 28627 - TA-W-80,340; TA-W-80,340A; TA-W-80,340B

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-15

...] Bush Industries, Inc., Mason Drive Facility, Including On-Site Leased Workers From Morris Security...., Mason Drive Facility, Jamestown, New York (TA-W-80,340) and Bush Industries, Inc., Allen Street Facility... applicable to TA-W-80,340 is hereby issued as follows: All workers of Bush Industries, Inc., Mason Drive...

Identification and characterization of Theileria ovis surface protein (ToSp) resembled TaSp in Theileria annulata.

PubMed

Shayan, P; Jafari, S; Fattahi, R; Ebrahimzade, E; Amininia, N; Changizi, E

2016-05-01

Ovine theileriosis is an important hemoprotozoal disease of sheep and goats in tropical and subtropical regions which caused high economic loses in the livestock industry. Theileria annulata surface protein (TaSp) was used previously as a tool for serological analysis in livestock. Since the amino acid sequences of TaSp is, at least, in part very conserved in T. annulata, Theileria lestoquardi and Theileria china I and II, it is very important to determine the amino acid sequence of this protein in Theileria ovis as well, to avoid false interpretation of serological data based on this protein in small animal. In the present study, the nucleotide sequence and amino acid sequence of T. ovis surface protein (ToSp) were determined. The comparison of the nucleotide sequence of ToSp showed 96, 96, 99, and 86 % homology to the corresponding nucleotide sequence of TaSp genes by T. annulata, T. China I, T. China II and T. lestoquardi, previously registered in GenBank under accession nos. AJ316260.1, AY274329.1, DQ120058.1, and EF092924.1 respectively. The amino acid sequence analysis showed 95, 81, 98 and 70 % homology to the corresponding amino acid sequence of T. annulata, T chinaI, T china II and T. lestoquardi, registered in GenBank under accession nos. CAC87478.1, AAP36993.1, AAZ30365.1 and AAP36999.11, respectively. Interestingly, in contrast to the C terminus, a significant difference in amino acid sequence in the N teminus of the ToSp protein could be determined compared to the other known corresponding TaSp sequences, which make this region attractive for designing of a suitable tool for serological diagnosis.

Drought-Up-Regulated TaNAC69-1 is a Transcriptional Repressor of TaSHY2 and TaIAA7, and Enhances Root Length and Biomass in Wheat.

PubMed

Chen, Dandan; Richardson, Terese; Chai, Shoucheng; Lynne McIntyre, C; Rae, Anne L; Xue, Gang-Ping

2016-10-01

A well-known physiological adaptation process of plants encountering drying soil is to achieve water balance by reducing shoot growth and maintaining or promoting root elongation, but little is known about the molecular basis of this process. This study investigated the role of a drought-up-regulated Triticum aestivum NAC69-1 (TaNAC69-1) in the modulation of root growth in wheat. TaNAC69-1 was predominantly expressed in wheat roots at the early vegetative stage. Overexpression of TaNAC69-1 in wheat roots using OsRSP3 (essentially root-specific) and OsPIP2;3 (root-predominant) promoters resulted in enhanced primary seminal root length and a marked increase in maturity root biomass. Competitive growth analysis under water-limited conditions showed that OsRSP3 promoter-driven TaNAC69-1 transgenic lines produced 32% and 35% more above-ground biomass and grains than wild-type plants, respectively. TaNAC69-1 overexpression in the roots down-regulated the expression of TaSHY2 and TaIAA7, which are from the auxin/IAA (Aux/IAA) transcriptional repressor gene family and are the homologs of negative root growth regulators SHY2/IAA3 and IAA7 in Arabidopsis. The expression of TaSHY2 and TaIAA7 in roots was down-regulated by drought stress and up-regulated by cytokinin treatment, which inhibited root growth. DNA binding and transient expression analyses revealed that TaNAC69-1 bound to the promoters of TaSHY2 and TaIAA7, acted as a transcriptional repressor and repressed the expression of reporter genes driven by the TaSHY2 or TaIAA7 promoter. These data suggest that TaNAC69-1 is a transcriptional repressor of TaSHY2 and TaIAA7 homologous to Arabidopsis negative root growth regulators and is likely to be involved in promoting root elongation in drying soil. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Wheat Transcription Factor TaAREB3 Participates in Drought and Freezing Tolerances in Arabidopsis.

PubMed

Wang, Jingyi; Li, Qian; Mao, Xinguo; Li, Ang; Jing, Ruilian

2016-01-01

AREB (ABA response element binding) proteins in plants play direct regulatory roles in response to multiple stresses, but their functions in wheat (Triticum aestivum L.) are not clear. In the present study, TaAREB3, a new member of the AREB transcription factor family, was isolated from wheat. Sequence analysis showed that the TaAREB3 protein is composed of three parts, a conserved N-terminal, a variable M region, and a conserved C-terminal with a bZIP domain. It belongs to the group A subfamily of bZIP transcription factors. TaAREB3 was constitutively expressed in stems, leaves, florets, anthers, pistils, seeds, and most highly, in roots. TaAREB3 gene expression was induced with abscisic acid (ABA) and low temperature stress, and its protein was localized in the nucleus when transiently expressed in tobacco epidermal cells and stably expressed in transgenic Arabidopsis. TaAREB3 protein has transcriptional activation activity, and can bind to the ABRE cis-element in vitro. Overexpression of TaAREB3 in Arabidopsis not only enhanced ABA sensitivity, but also strengthened drought and freezing tolerances. TaAREB3 also activated RD29A, RD29B, COR15A, and COR47 by binding to their promoter regions in transgenic Arabidopsis. These results demonstrated that TaAREB3 plays an important role in drought and freezing tolerances in Arabidopsis.

Wheat Transcription Factor TaAREB3 Participates in Drought and Freezing Tolerances in Arabidopsis

PubMed Central

Wang, Jingyi; Li, Qian; Mao, Xinguo; Li, Ang; Jing, Ruilian

2016-01-01

AREB (ABA response element binding) proteins in plants play direct regulatory roles in response to multiple stresses, but their functions in wheat (Triticum aestivum L.) are not clear. In the present study, TaAREB3, a new member of the AREB transcription factor family, was isolated from wheat. Sequence analysis showed that the TaAREB3 protein is composed of three parts, a conserved N-terminal, a variable M region, and a conserved C-terminal with a bZIP domain. It belongs to the group A subfamily of bZIP transcription factors. TaAREB3 was constitutively expressed in stems, leaves, florets, anthers, pistils, seeds, and most highly, in roots. TaAREB3 gene expression was induced with abscisic acid (ABA) and low temperature stress, and its protein was localized in the nucleus when transiently expressed in tobacco epidermal cells and stably expressed in transgenic Arabidopsis. TaAREB3 protein has transcriptional activation activity, and can bind to the ABRE cis-element in vitro. Overexpression of TaAREB3 in Arabidopsis not only enhanced ABA sensitivity, but also strengthened drought and freezing tolerances. TaAREB3 also activated RD29A, RD29B, COR15A, and COR47 by binding to their promoter regions in transgenic Arabidopsis. These results demonstrated that TaAREB3 plays an important role in drought and freezing tolerances in Arabidopsis. PMID:26884722

Pressure-induced ferroelectric to paraelectric transition in LiTaO 3 and (Li,Mg)TaO 3

DOE PAGES

Yamanaka, Takamitsu; Nakamoto, Yuki; Takei, Fumihiko; ...

2016-02-16

X-ray powder diffraction and Raman scattering of LiTaO 3 (LT) and (Li,Mg)TaO 3 (LMT) have been measured under pressure up to 46 GPa. Above 30 GPa, the ferroelectric rhombohedral phase (R3c, Z – 6) of LiTaO 3 transforms to a paraelectric orthorhombic phase (Pnma with Z – 4) with a large hysteresis. Rietveld profile fitting analysis shows that the Li-O bond is compressed and approaches that of Ta-O with pressure. The cation distribution analysis of the orthorhombic perovskite structure shows that Li and Ta are located in the octahedral 8-fold coordination sites. Difference Fourier |F obs(hkl)| - |F cal(hkl)| mapsmore » of LiTaO 3 and (Li,Mg)TaO 3 indicate polarization in the c axis direction and a more distinct electron density distribution around the Ta position for (Li,Mg)TaO 3 compared to LiTaO 3. The observed effective charges indicate that for (Li,Mg)TaO 3 without vacancies Ta 5+ becomes less ionized as a function of Mg substitution. Considering both site occupancy and effective charge analysis, Ta 5+ is reduced to Ta 4.13+. Mg 2+ and O 2- change to Mg 1.643+ and O 1.732 -, respectively. The space- and time-averaged structures of the dynamical vibration of atoms can be elucidated from the electron density analysis by difference Fourier and temperature factors T(hkl) in the structure refinement. The refinement of the temperature factor is consistent with the cation distribution assuming full stoichiometry. The residual electron density induced from the excess electron in (Li,Mg)TaO 3 indicates more electrons around the Ta site, as confirmed by the effective charge analysis. Raman spectra of LiTaO 3 and (Li,Mg)TaO 3 show notable changes over the measured pressure range. Raman peaks centered at 250 cm –1 and 350 cm –1 at ambient pressure merge above 8 GPa, which we associate with the diminishing of difference in distances between Li-O and Ta-O bonds with pressure in both materials. Finally, Raman spectra show significant changes at 28 GPa and 33 GPa for

Effect of tartarate and citrate based food additives on the micellar properties of sodium dodecylsulfate for prospective use as food emulsifier.

PubMed

Banipal, Tarlok S; Kaur, Harjinder; Kaur, Amanpreet; Banipal, Parampaul K

2016-01-01

Citrate and tartarate based food preservatives can be used to enhance the emulsifying properties of sodium dodecylsulfate (SDS) based micellar system and thus making it appropriate for food applications. Exploration of interactions between the two species is the key constraint for execution of such ideas. In this work various micellar and thermodynamic parameters of SDS like critical micellar concentration (CMC), standard Gibbs free energy of micellization (ΔG(0)mic.) etc. have been calculated in different concentrations of disodium tartarate (DST) and trisodium citrate (TSC) in the temperature range (288.15-318.15)K from the conductivity and surface tension measurements. The parameters obtained from these studies reveal the competitive nature of both the additives with SDS for available positions at the air/water interface. TSC is found to be more effective additive in order to make SDS micellar system better for its potential applications as food emulsifier. Copyright © 2015 Elsevier Ltd. All rights reserved.

Conditions and chemometrics for the determination of heavy metals in natural and waste waters by stripping voltammetry with UV irradiation

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

Volkova, V.N.; Zakharova, E.A.; Khustenko, L.A.

The number of supporting electrolytes for stripping voltammetry with photochemical oxygen deactivation was broadened. The following agents are recommended: formic, lactic, tartaric, citric, and malonic acids at pH 2-4; salts of lactic, tartaric, and citric acids at pH 6-7; and salts of lactic, tartaric, citric, and glutaric acids at pH 12-14. A rapid method was developed for simultaneously determining Zn, Cd, Pb, and Cu in a 0.5 M formic acid supporting electrolyte. The method is chemometrically sound and cost-effective.

Orientation dependences of atomic structures in chemically heterogeneous Cu{sub 50}Ta{sub 50}/Ta glass-crystal interfaces

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

Yang, Guiqin; Gao, Xiaoze; Li, Jinfu

2015-01-07

Molecular dynamics simulations based on an angular-dependent potential were performed to examine the structural properties of chemically heterogeneous interfaces between amorphous Cu{sub 50}Ta{sub 50} and crystalline Ta. Several phenomena, namely, layering, crystallization, intermixing, and composition segregation, were observed in the Cu{sub 50}Ta{sub 50} region adjacent to the Ta layers. These interfacial behaviors are found to depend on the orientation of the underlying Ta substrate: Layering induced by Ta(110) extends the farthest into Cu{sub 50}Ta{sub 50}, crystallization in the Cu{sub 50}Ta{sub 50} region is most significant for interface against Ta(100), while inter-diffusion is most pronounced for Ta(111). It turns out thatmore » the induced layering behavior is dominated by the interlayer distances of the underlying Ta layers, while the degree of inter-diffusion is governed by the openness of the Ta crystalline layers. In addition, composition segregations are observed in all interface models, corresponding to the immiscible nature of the Cu-Ta system. Furthermore, Voronoi polyhedra 〈0,5,2,6〉 and 〈0,4,4,6〉 are found to be abundant in the vicinity of the interfaces for all models, whose presence is believed to facilitate the structural transition between amorphous and body centered cubic.« less

The role of the F-box gene TaFBA1 from wheat (Triticum aestivum L.) in drought tolerance.

PubMed

Zhou, Shumei; Sun, Xiudong; Yin, Suhong; Kong, Xiangzhu; Zhou, Shan; Xu, Ying; Luo, Yin; Wang, Wei

2014-11-01

Drought is one of the most important factors limiting plant growth and development. We identified a gene in wheat (Triticum aestivum L.) under drought stress named TaFBA1. TaFBA1 encodes a putative 325-amino-acid F-box protein with a conserved N-terminal F-box domain and a C-terminal AMN1 domain. Real-time RT-PCR analysis revealed that TaFBA1 transcript accumulation was upregulated by high-salinity, water stress, and abscisic acid (ABA) treatment. To evaluate the functions of TaFBA1 in the regulation of drought stress responses, we produced transgenic tobacco lines overexpressing TaFBA1. Under water stress conditions, the transgenic tobacco plants had a higher germination rate, higher relative water content, net photosynthesis rate (Pn), less chlorophyll loss, and less growth inhibition than WT. These results demonstrate the high tolerance of the transgenic plants to drought stress compared to the WT. The enhanced oxidative stress tolerance of these plants, which may be involved in their drought tolerance, was indicated by their lower levels of reactive oxygen species (ROS) accumulation, MDA content, and cell membrane damage under drought stress compared to WT. The antioxidant enzyme activities were higher in the transgenic plants than in WT, which may be related to the upregulated expression of some antioxidant genes via overexpression of TaFBA1. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Characterization of a wheat (Triticum aestivum L.) expansin gene, TaEXPB23, involved in the abiotic stress response and phytohormone regulation.

PubMed

Han, Yang yang; Li, Ai xiu; Li, Feng; Zhao, Mei rong; Wang, Wei

2012-05-01

Expansins are proteins that are generally accepted to be key regulators of cell wall extension and plant growth. We examined the expression pattern of TaEXPB23, a wheat (Triticum aestivum L.) expansin gene, under exogenous phytohormone and abiotic stress treatments. In addition, we evaluated its function in the tolerance to salt stress and high temperature (HT) by overexpressing it in transgenic tobacco plants. In subcellular localization assays, TaEXPB23 localized to the cell wall. Expression analysis demonstrated that the transcription pattern of TaEXPB23 corresponded to wheat coleoptile growth. Real-time RT-PCR analysis revealed that TaEXPB23 transcript expression was upregulated by exogenous methyl jasmonate (MeJA) and salt stress, but downregulated by exogenous gibberellins (GA₃), ethylene (ET), indole-3-acetic acid (IAA) and α-naphthlcetic acid (NAA). Overexpression of TaEXPB23 in tobacco (tabacum) conferred tolerance to salt stress by enhancing water retention ability (WRA) and decreasing osmotic potential (OP). However, transgenic plants overexpressing TaEXPB23 did not show any improvement in the tolerance to HT stress. These results suggested that TaEXPB23 is regulated by phytohormones and is involved in the regulation of salt stress tolerance. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Electrodeposition of Al-Ta alloys in NaCl-KCl-AlCl3 molten salt containing TaCl5

NASA Astrophysics Data System (ADS)

Sato, Kazuki; Matsushima, Hisayoshi; Ueda, Mikito

2016-12-01

To form Al-Ta alloys for high temperature oxidation resistance components, molten salt electrolysis was carried out in an AlCl3-NaCl-KCl melt containing TaCl5 at 423 K. The voltammogram showed two cathodic waves at 0.45 V and 0.7 V vs. Al/Al(III), which may correspond to reduction from Ta(V) to Ta(III) and from Ta(III) to tantalum metal, respectively. Electrodeposits of Al and Ta were obtained in the range from -0.05 to 0.3 V and the highest concentration of Ta in the electrodeposit was 72 at% at 0.3 V. With increasing Ta content in the alloy, the morphology of the electrodeposits became powdery and the particle size smaller.

Tannic acid-mediated green synthesis of antibacterial silver nanoparticles.

PubMed

Kim, Tae Yoon; Cha, Song-Hyun; Cho, Seonho; Park, Youmie

2016-04-01

The search for novel antibacterial agents is necessary to combat microbial resistance to current antibiotics. Silver nanoparticles (AgNPs) have been reported to be effective antibacterial agents. Tannic acid is a polyphenol compound from plants with antioxidant and antibacterial activities. In this report, AgNPs were prepared from silver ions by tannic acid-mediated green synthesis (TA-AgNPs). The reaction process was facile and involved mixing both silver ions and tannic acid. The absorbance at 423 nm in the UV-Visible spectra demonstrated that tannic acid underwent a reduction reaction to produce TA-AgNPs from silver ions. The synthetic yield of TA-AgNPs was 90.5% based on inductively coupled plasma mass spectrometry analysis. High-resolution transmission electron microscopy and atomic force microscopy images indicated that spherical-shaped TA-AgNPs with a mean particle size of 27.7-46.7 nm were obtained. Powder high-resolution X-ray diffraction analysis indicated that the TA-AgNP structure was face-centered cubic with a zeta potential of -27.56 mV. The hydroxyl functional groups of tannic acid contributed to the synthesis of TA-AgNPs, which was confirmed by Fourier transform infrared spectroscopy. The in vitro antibacterial activity was measured using the minimum inhibitory concentration (MIC) method. The TA-AgNPs were more effective against Gram-negative bacteria than Gram-positive bacteria. The MIC for the TA-AgNPs in all of the tested strains was in a silver concentration range of 6.74-13.48 μg/mL. The tannic acid-mediated synthesis of AgNPs afforded biocompatible nanocomposites for antibacterial applications.

Enantioselective recognition of mandelic acid by a 3,6-dithiophen-2-yl-9H-carbazole-based chiral fluorescent bisboronic acid sensor.

PubMed

Wu, Yubo; Guo, Huimin; James, Tony D; Zhao, Jianzhang

2011-07-15

We have prepared chiral fluorescent bisboronic acid sensors with 3,6-dithiophen-2-yl-9H-carbazole as the fluorophore. The thiophene moiety was used to extend the π-conjugation framework of the fluorophore in order to red-shift the fluorescence emission and, at the same time, to enhance the novel process where the fluorophore serves as the electron donor of the photoinduced electron transfer process (d-PET) of the boronic acid sensors; i.e., the background fluorescence of the sensor 1 at acidic pH is weaker compared to that at neutral or basic pH, in stark contrast to the typical a-PET boronic acid sensors (where the fluorophore serves as the electron acceptor of the photoinduced electron transfer process). The benefit of the d-PET boronic acid sensors is that the recognition of the hydroxylic acids can be achieved at acidic pH. We found that the thiophene moiety is an efficient π-conjugation linker and electron donor; as a result, the d-PET contrast ratio of the sensors upon variation of the pH is improved 10-fold when compared to the previously reported d-PET sensors without the thiophene moiety. Enantioselective recognition of tartaric acid was achieved at acid pH, and the enantioselectivity (total response K(D)I(F)(D)/K(L)I(F)(L)) is 3.3. The fluorescence enhancement (I(F)(Sample)/I(F)(Blank)) of sensor 1 upon binding with tartaric acid is 3.5-fold at pH 3.0. With the fluorescent bisboronic acid sensor 1, enantioselective recognition of mandelic acid was achieved for the first time. To the best of our knowledge, this is the first time that the mandelic acid has been enantioselectively recognized using a chiral fluorescent boronic acid sensor. Chiral monoboronic acid sensor 2 and bisboronic acid sensor 3 without the thiophene moiety failed to enantioselectively recognize mandelic acid. Our findings with the thiophene-incorporated boronic acid sensors will be important for the design of d-PET fluorescent sensors for the enantioselective recognition of �

EUSO-TA prototype telescope

NASA Astrophysics Data System (ADS)

Bisconti, Francesca; JEM-EUSO Collaboration

2016-07-01

EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

Mussel inspired polymerized P(TA-TETA) for facile functionalization of carbon nanotube

NASA Astrophysics Data System (ADS)

Si, Shuxian; Gao, Tingting; Wang, Junhao; Liu, Qinze; Zhou, Guowei

2018-03-01

This article describes a novel and effective approach for non-covalent modification of carbon nanotube (CNT) via the mussel inspired polymerization of tannic acid (TA) and triethylenetetramine (TETA) and subsequent surface initiated atom transfer radical polymerization (SI-ATRP). Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photograph were used to study the successful preparation of polymer brush grafted CNT (CNT-P(TA-TETA)-PDMAEMA) composite as well as the pH-responsive behavior of the composite. Furthermore, by amine protonation and in situ reduction, gold nanoparticles were successfully uploaded and the catalytic property of CNT-P(TA-TETA)-PDMAEMA/Au was investigated. We believe that the surface functionalization strategy can be extended to graphene and other substrates, and the surface properties can be regulated by grafting polymer brushes with different functionalities.

Formation and characterization of Ta2O5/TaOx films formed by O ion implantation

NASA Astrophysics Data System (ADS)

Ruffell, S.; Kurunczi, P.; England, J.; Erokhin, Y.; Hautala, J.; Elliman, R. G.

2013-07-01

Ta2O5/TaOx (oxide/suboxide) heterostructures are fabricated by high fluence O ion-implantation into deposited Ta films. The resultant films are characterized by depth profiling X-ray photoelectron spectroscopy (XPS), cross-sectional transmission electron microscopy (XTEM), four-point probe, and current-voltage and capacitance-voltage measurements. The measurements show that Ta2O5/TaOx oxide/suboxide heterostructures can be fabricated with the relative thicknesses of the layers controlled by implantation energy and fluence. Electrical measurements show that this approach has promise for high volume manufacturing of resistive switching memory devices based on oxide/suboxide heterostructures.

The Novel Wheat Transcription Factor TaNAC47 Enhances Multiple Abiotic Stress Tolerances in Transgenic Plants

PubMed Central

Zhang, Lina; Zhang, Lichao; Xia, Chuan; Zhao, Guangyao; Jia, Jizeng; Kong, Xiuying

2016-01-01

NAC transcription factors play diverse roles in plant development and responses to abiotic stresses. However, the biological roles of NAC family members in wheat are not well understood. Here, we reported the isolation and functional characterization of a novel wheat TaNAC47 gene. TaNAC47 encoded protein, localizing in the nucleus, is able to bind to the ABRE cis-element and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional activator. We also showed that TaNAC47 is differentially expressed in different tissues, and its expression was induced by the stress treatments of salt, cold, polyethylene glycol and exogenous abscisic acid. Furthermore, overexpression of TaNAC47 in Arabidopsis resulted in ABA hypersensitivity and enhancing tolerance of transgenic plants to drought, salt, and freezing stresses. Strikingly, overexpression of TaNAC47 was found to activate the expression of downstream genes and change several physiological indices that may enable transgenic plants to overcome unfavorable environments. Taken together, these results uncovered an important role of wheat TaNAC47 gene in response to ABA and abiotic stresses. PMID:26834757

The Novel Wheat Transcription Factor TaNAC47 Enhances Multiple Abiotic Stress Tolerances in Transgenic Plants.

PubMed

Zhang, Lina; Zhang, Lichao; Xia, Chuan; Zhao, Guangyao; Jia, Jizeng; Kong, Xiuying

2015-01-01

NAC transcription factors play diverse roles in plant development and responses to abiotic stresses. However, the biological roles of NAC family members in wheat are not well understood. Here, we reported the isolation and functional characterization of a novel wheat TaNAC47 gene. TaNAC47 encoded protein, localizing in the nucleus, is able to bind to the ABRE cis-element and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional activator. We also showed that TaNAC47 is differentially expressed in different tissues, and its expression was induced by the stress treatments of salt, cold, polyethylene glycol and exogenous abscisic acid. Furthermore, overexpression of TaNAC47 in Arabidopsis resulted in ABA hypersensitivity and enhancing tolerance of transgenic plants to drought, salt, and freezing stresses. Strikingly, overexpression of TaNAC47 was found to activate the expression of downstream genes and change several physiological indices that may enable transgenic plants to overcome unfavorable environments. Taken together, these results uncovered an important role of wheat TaNAC47 gene in response to ABA and abiotic stresses.

Compositional Variation in Sugars and Organic Acids at Different Maturity Stages in Selected Small Fruits from Pakistan

PubMed Central

Mahmood, Tahir; Anwar, Farooq; Abbas, Mateen; Boyce, Mary C.; Saari, Nazamid

2012-01-01

Selected soluble sugars and organic acids were analyzed in strawberry, sweet cherry, and mulberry fruits at different ripening stages by HPLC. The amounts of fructose, glucose and sucrose were found to be: strawberry (1.79–2.86, 1.79–2.25 and 0.01–0.25 g/100 g FW), sweet cherry (0.76–2.35, 0.22–3.39 and 0.03–0.13 g/100 g) and mulberry (3.07–9.41, 1.53–4.95 and 0.01–0.25 g/100 g) at un-ripened to fully-ripened stages, respectively. The strawberry, sweet cherry and mulberry mainly contained tartaric, citric and ascorbic acids in the range of 16–55, 70–1934 and 11–132 mg/100 g; 2–8, 2–10 and 10–17 mg/100 g; 2–118, 139–987 and 2–305 mg/100 g at un-ripened to fully-ripened stages, respectively. Fructose and glucose were established to be the major sugars in all the tested fruit while citric and ascorbic acid were the predominant organic acids in strawberry and mulberry while tartaric acid was mainly present in sweet cherry. The tested fruits mostly showed an increase in the concentration of sugars and organic acids with ripening. PMID:22408396

Nanostructured TaON/Ta3N5 as a highly efficient type-II heterojunction photoanode for photoelectrochemical water splitting.

PubMed

Pei, Lang; Wang, Hongxu; Wang, Xiaohui; Xu, Zhe; Yan, Shicheng; Zou, Zhigang

2018-06-20

Enhancing the charge separation by a semiconductor heterojunction is greatly promising and challenging for photoelectrochemical (PEC) water splitting. Here, we report for the first time the design and fabrication of a TaON/Ta3N5 heterojunction photoanode, in which the electrode Ta3N5 is the primary light absorber and TaON acts as an electron conductor. By combining the merits of the substantial light harvesting of Ta3N5 with the excellent charge transport capability of TaON, the TaON/Ta3N5 heterojunction photoanode, without any co-catalysts, shows a 350 mV negative shift of photocurrent onset potential to 0.65 V versus the reversible hydrogen electrode (RHE) compared to that of the Ta3N5 photoanode. The design and fabrication scheme can be readily extended to other (oxy)nitride semiconductors for heterojunction construction.

Functional, structural and phylogenetic analysis of domains underlying the Al-sensitivity of the aluminium-activated malate/anion transporter, TaALMT1

USDA-ARS?s Scientific Manuscript database

TaALMT1 (Triticum aestivum Aluminum Activated Malate Transporter) is the founding member of a novel gene family of anion transporters (ALMTs) that mediate the efflux of organic acids. A small subgroup of root-localized ALMTs, including TaALMT1, is physiologically associated with in planta aluminum (...

Silicide formation process of Er films with Ta and TaN capping layers.

PubMed

Choi, Juyun; Choi, Seongheum; Kim, Jungwoo; Na, Sekwon; Lee, Hoo-Jeong; Lee, Seok-Hee; Kim, Hyoungsub

2013-12-11

The phase development and defect formation during the silicidation reaction of sputter-deposited Er films on Si with ∼20-nm-thick Ta and TaN capping layers were examined. TaN capping effectively prevented the oxygen incorporation from the annealing atmosphere, which resulted in complete conversion to the ErSi2-x phase. However, significant oxygen penetration through the Ta capping layer inhibited the ErSi2-x formation, and incurred the growth of several Er-Si-O phases, even consuming the ErSi2-x layer formed earlier. Both samples produced a number of small recessed defects at an early silicidation stage. However, large rectangular or square-shaped surface defects, which were either pitlike or pyramidal depending on the capping layer identity, were developed as the annealing temperature increased. The origin of different defect generation mechanisms was suggested based on the capping layer-dependent silicidation kinetics.

Occurrence of Polyphenols, Organic Acids, and Sugars among Diverse Elderberry Genotypes Grown in Three Missouri (USA) Locations

PubMed Central

Thomas, A.L.; Byers, P.L.; Gu, S.; Avery, J.D.; Kaps, M.; Datta, A.; Fernando, L.; Grossi, P.; Rottinghaus, G.E.

2016-01-01

Elderberry (Sambucus spp.) is an emerging horticultural crop used in a variety of foods, wines, and dietary supplements. A better understanding of the elderberry juice complex including its putative health-promoting compounds in relation to genetic and environmental parameters is needed. A multi-location planting of nine elderberry genotypes was established in 2008 at three geographically-diverse sites in Missouri, USA. Fruits were harvested from replicated plots 2009-2011, frozen, and later prepared for laboratory analysis. Polyphenols, organic acids, and sugars were quantified by HPLC and the results evaluated for response to genotype, site, and year. The American genotypes ‘Ocoee’ and ‘Ozark’ were consistently higher in chlorogenic acids compared to other genotypes, whereas ‘Ocoee’ was significantly higher in rutin than ‘Ozark’. The European ‘Marge’ was significantly higher in isoquercitrin and other flavonoids compared to most North American genotypes. Significant differences in polyphenols were also detected among sites and production years. Malic, citric, and tartaric acids varied significantly among genotypes, sites, and years, whereas succinic, shikimic, and fumaric acids generally did not. Levels of lactic, acetic, and propionic acids were negligible in most samples. The American genotype ‘Ocoee’ was higher in citric and tartaric acids, while lower in malic acid. The sugars glucose and fructose also responded significantly to genotype, site, and year. ‘Ocoee’, ‘Ozark’, and ‘Marge’ perform very well in Missouri horticulturally and appear to have additional potential as cultivars based on their unique juice characteristics. PMID:27156707

Bone response to a novel Ti-Ta-Nb-Zr alloy.

PubMed

Stenlund, Patrik; Omar, Omar; Brohede, Ulrika; Norgren, Susanne; Norlindh, Birgitta; Johansson, Anna; Lausmaa, Jukka; Thomsen, Peter; Palmquist, Anders

2015-07-01

Commercially pure titanium (cp-Ti) is regarded as the state-of-the-art material for bone-anchored dental devices, whereas the mechanically stronger alloy (Ti-6Al-4V), made of titanium, aluminum (Al) and vanadium (V), is regarded as the material of choice for high-load applications. There is a call for the development of new alloys, not only to eliminate the potential toxic effect of Al and V but also to meet the challenges imposed on dental and maxillofacial reconstructive devices, for example. The present work evaluates a novel, dual-stage, acid-etched, Ti-Ta-Nb-Zr alloy implant, consisting of elements that create low toxicity, with the potential to promote osseointegration in vivo. The alloy implants (denoted Ti-Ta-Nb-Zr) were evaluated after 7 days and 28 days in a rat tibia model, with reference to commercially pure titanium grade 4 (denoted Ti). Analyses were performed with respect to removal torque, histomorphometry and gene expression. The Ti-Ta-Nb-Zr showed a significant increase in implant stability over time in contrast to the Ti. Further, the histological and gene expression analyses suggested faster healing around the Ti-Ta-Nb-Zr, as judged by the enhanced remodeling, and mineralization, of the early-formed woven bone and the multiple positive correlations between genes denoting inflammation, bone formation and remodeling. Based on the present experiments, it is concluded that the Ti-Ta-Nb-Zr alloy becomes osseointegrated to at least a similar degree to that of pure titanium implants. This alloy is therefore emerging as a novel implant material for clinical evaluation. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Fogging low concentrated organic acid in a fattening pig unit - Effect on animal health and microclimate.

PubMed

Stein, Heiko; Schulz, Jochen; Kemper, Nicole; Tichy, Alexander; Krauss, Ines; Knecht, Christian; Hennig-Pauka, Isabel

2016-12-23

In intensive pig production aerial contaminates are potential hazards for the health of animals and humans. In this study, the effect of fogging a low concentrated tartaric acid solution on pigs' health, environmental and hygiene parameters were evaluated in an inhabited fattening unit. Pigs were housed in separate units (control group n=109 and experimental group n=110). During the whole fattening period, twice a week at 48 hour intervals, a 0.1% tartaric acid solution was aerosolized by a cold-fogging system for 20 minutes in the experimental unit. Environmental parameters were spot-checked on days of fogging. Sedimentation dust and surfaces were analysed for bacterial and fungal load. Dust particle size distribution was assessed. Pigs were clinically examined weekly. Standard meat examination at an abattoir was extended by individual quantification of lung alterations. The fogging procedure had no influence on ammonia concentrations. A significant reduction of mould, but not of bacteria, was found in sedimentation dust, and bacterial and mould scores of surface samples were improved. A significant reduction of particle size classes 1.6-2.0 µm, 4.0-5.0 µm, 7.5-10 µm, as well as 10-15 µm was observed. The high sound level of the fogging machine (82-102 dB) led to higher activity and pen-mate directed behaviour. More skin alterations, conjunctivitis and sneezing were recorded in the experimental group. Gross pathological lung alterations did not differ between both groups. Although fogging of tartaric acid is limited to a concentration of 0.1% due to its irritating effect on the respiratory mucosa, reduction of microbial load can be achieved, but it would be enhanced by using more powerful fogging systems.

Three TaFAR genes function in the biosynthesis of primary alcohols and the response to abiotic stresses in Triticum aestivum

PubMed Central

Wang, Meiling; Wang, Yong; Wu, Hongqi; Xu, Jing; Li, Tingting; Hegebarth, Daniela; Jetter, Reinhard; Chen, Letian; Wang, Zhonghua

2016-01-01

Cuticular waxes play crucial roles in protecting plants against biotic and abiotic stresses. They are complex mixtures of very-long-chain fatty acids and their derivatives, including C20–C32 fatty alcohols. Here, we report the identification of 32 FAR-like genes and the detailed characterization of TaFAR2, TaFAR3 and TaFAR4, wax biosynthetic genes encoding fatty acyl-coenzyme A reductase (FAR) in wheat leaf cuticle. Heterologous expression of the three TaFARs in wild-type yeast and mutated yeast showed that TaFAR2, TaFAR3 and TaFAR4 were predominantly responsible for the accumulation of C18:0, C28:0 and C24:0 primary alcohols, respectively. Transgenic expression of the three TaFARs in tomato fruit and Arabidopsis cer4 mutant led to increased production of C22:0–C30:0 primary alcohols. GFP-fusion protein injection assay showed that the three encoded TaFAR proteins were localized to the endoplasmic reticulum (ER), the site of wax biosynthesis. The transcriptional expression of the three TaFAR genes was induced by cold, salt, drought and ABA. Low air humidity led to increased expression of TaFAR genes and elevated wax accumulation in wheat leaves. Collectively, these data suggest that TaFAR2, TaFAR3 and TaFAR4 encode active alcohol-forming FARs involved in the synthesis of primary alcohol in wheat leaf and the response to environmental stresses. PMID:27112792

Assessment of relative Ti, Ta, and Nb (TiTaN) enrichments in global ocean island basalts

NASA Astrophysics Data System (ADS)

Peters, B.; Day, J. M.

2013-12-01

The relative sensitivity of trace element concentrations to processes governing solid-melt and solid-fluid interactions has made them particularly useful for tracing the effects of partial melting, fractional crystallization, metasomatism and similar processes on the composition of a parental melt to a rock or mineral. Radiogenic and stable isotope compositions, in contrast, can provide information on the long-term history and provenance of magmas. Despite the distinct information derived from relative and absolute abundances of trace elements compared with isotopes, numerous studies of ocean island basalts (OIB) have attempted to use trace elements as diagnostic geochemical tracers to understand parental magma compositions. In particular, attempts have been made to correlate 'TiTaN' (Ti, Ta and Nb) anomalies to the He-Os isotopic compositions of OIB based on contributions from recycled eclogite, a theoretical high-TiTaN reservoir, and peridotite, a theoretical high-3He/4He reservoir (Jackson, et al., 2008 G-cubed). These authors have proposed that TiTaN anomalies can be used as independent indicators for recycled oceanic crust and lithospheric mantle in OIB sources, a distinction previously reserved for isotopic data. However, TiTaN anomalies appear uncorrelated to OIB mantle source composition for three reasons. First, a new geochemical compilation of global OIB shows a wide range of Ti (Ti/Ti* = 0.28 - 2.35), Ta (Ta/Ta* = 0.11 - 93.42) and Nb (Nb/Nb* = 0.13 - 17.79) anomalies that do not correlated with each other or noble gas systematics, indicating that: (i) TiTaN anomalies alone do not correspond to the primitive source traced by high-3He/4He or the solar neon component and (ii) Ti, Ta and Nb anomalies may each reflect distinct processes or origins, rather than tracing a single source or process together. Second, positive Ti anomalies can be generated by low-degree (1-10%), non-modal batch partial melting of garnet lherzolite at temperatures and pressures

Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat.

PubMed

Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

2016-01-01

Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat, while total soluble phenolic acid, soluble ferulic acid, and vanillic acid levels were significantly higher in purple and red wheat than in white wheat. Ferulic acid and syringic acid levels peaked at 14 days after anthesis (DAA), whereas p-coumaric acid and caffeic acid levels peaked at 7 DAA, and vanillic acid levels gradually increased during grain filling and peaked near ripeness (35 DAA). Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acids levels. White wheat had higher phenolic acid contents and relatively high gene expression at the early stage, while purple wheat had the highest phenolic acid contents and gene expression levels at later stages. These results suggest that the expression of phenolic acid biosynthesis genes may be closely related to phenolic acids accumulation.

Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat

PubMed Central

Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

2016-01-01

Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat, while total soluble phenolic acid, soluble ferulic acid, and vanillic acid levels were significantly higher in purple and red wheat than in white wheat. Ferulic acid and syringic acid levels peaked at 14 days after anthesis (DAA), whereas p-coumaric acid and caffeic acid levels peaked at 7 DAA, and vanillic acid levels gradually increased during grain filling and peaked near ripeness (35 DAA). Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acids levels. White wheat had higher phenolic acid contents and relatively high gene expression at the early stage, while purple wheat had the highest phenolic acid contents and gene expression levels at later stages. These results suggest that the expression of phenolic acid biosynthesis genes may be closely related to phenolic acids accumulation. PMID:27148345

Tribological properties of self-lubricating Ta-Cu films

NASA Astrophysics Data System (ADS)

Qin, Wen; Fu, Licai; Zhu, Jiajun; Yang, Wulin; Li, Deyi; Zhou, Lingping

2018-03-01

In this paper, Ta and TaCu films were deposited by using magnetron sputtering, and the tribological properties of the films against Si3N4 balls were investigated under the loads of 2 N and 5 N. The average grain sizes of both films are below 25 nm. Ta and TaCu films have approximate hardness. While the wear rate of TaCu film is much smaller than that of Ta film. Post-wear testing XRD, Raman and XPS revealed the formation of tantalum oxide on the worn surface of both Ta and TaCu films. Tantalum oxidation is effectively lubricating to reduce friction coefficient. So the friction coefficient of both Ta and TaCu film is about 0.45 under different applied loads. Meanwhile, the addition of Cu could increase the toughness of the film, and avoid the generation of wear debris, resulting in a significant increase in wear resistance.

Hyaluronan/Tannic Acid Nanoparticles Via Catechol/Boronate Complexation as a Smart Antibacterial System.

PubMed

Montanari, Elita; Gennari, Arianna; Pelliccia, Maria; Gourmel, Charlotte; Lallana, Enrique; Matricardi, Pietro; McBain, Andrew J; Tirelli, Nicola

2016-12-01

Nanoparticles based on hyaluronic acid (HA) are designed to deliver tannic acid (TA) as an antimicrobial agent. The presence of HA makes these particles potentially useful to target bacteria that colonize cells presenting HA membrane receptors (e.g. CD44), such as macrophages. HA bearing 3-aminophenyl boronic acid groups (HA-APBA) is reacted with TA, yielding nanoparticles with a size that decreases with decreasing HA molecular weight (e.g. 200 nm for 44 kDa, 400 nm for 737 kDa). The boronate esters make the nanoparticles stable at physiological pH, but their hydrolysis in an acidic environment (pH = 5) leads to swelling/solubilization, therefore potentially allowing TA release in endosomal compartments. We have assessed the nanoparticle toxicity profile (on RAW 264.7 macrophages) and their antimicrobial activity (on E. coli and on both methicillin-sensitive and -resistant S. aureus). The antibacterial effect of HA-APBA/TA nanoparticles was significantly higher than that of TA alone, and has very similar activity to TA coformulated with a reducing agent (ascorbic acid), which indicates both the nanoparticles to protect TA catechols from oxidation, and the effective release of TA after nanoparticle internalization. Therefore, there is potential for these nanoparticles to be used in stable, effective, and potentially targetable nanoparticle-based antimicrobial formulations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Purification and characterization of vanillin dehydrogenases from alkaliphile Micrococcus sp. TA1 and neutrophile Burkholderia cepacia TM1.

PubMed

Mitsui, Ryoji; Hirota, Mizuho; Tsuno, Takuo; Tanaka, Mitsuo

2010-02-01

Vanillin dehydrogenases (VDHs) were purified and characterized from two bacterial strains that have different pH dependencies for growth. The alkaliphile Micrococcus sp. TA1, isolated from an alkaline spa, can grow on several aromatic compounds such as ferulic acid, vanillin, vanillic acid, and protocatechuic acid under alkaline conditions. The neutrophile Burkholderia cepacia TM1, which was isolated previously, also grew on the above-mentioned compounds because they functioned as the sole carbon source under neutral conditions. Purified VDHs showed activities toward some aromatic aldehydes. These enzymes have the same subunit molecular mass of about 57 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but differed in some of their observed properties. Native molecular masses also differed between the purified enzymes. These were 250 kDa for the enzyme from alkaliphilic strain TA1 and 110 kDa for that from neutrophilic strain TM1, as determined by gel filtration. The enzyme from strain TA1 required NADP(+) as a coenzyme for its activity, but that from strain TM1 required NAD(+). These results are important because this is the first report of an alkaliphilic bacterium consuming lignin monomers.

Wheat transcription factor TaWRKY70 is positively involved in high-temperature seedling plant resistance to Puccinia striiformis f. sp. tritici.

PubMed

Wang, Junjuan; Tao, Fei; An, Fei; Zou, Yiping; Tian, Wei; Chen, Xianming; Xu, Xiangming; Hu, Xiaoping

2017-06-01

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease of wheat (Triticum aestivum) worldwide. Wheat high-temperature seedling plant (HTSP) resistance to Pst is non-race-specific and durable. WRKY transcription factors have been proven to play important roles in plant defence responses to attacks by several pathogens. However, there is no direct evidence as to whether WRKY transcription factors play a role in HTSP resistance to Pst. We isolated a WRKY gene, named TaWRKY70, from wheat cultivar Xiaoyan 6. The expression level of TaWRKY70 was increased significantly when exposed to high temperatures (HTs) during the initial symptom expression stage of Pst infection. The expression of this gene increased in plants treated with ethylene (ET), salicylic acid (SA) and cold (4°C) stresses, but decreased in plants treated with methyl jasmonate (MeJA) and heat (40°C) stresses. Silencing of TaWRKY70 led to greater susceptibility to Pst (in terms of the increase in length of uredinial pustules and the decrease in the number of necrotic cells) compared with non-silenced plants when exposed to HT during the initial symptom expression stage of Pst infection, coinciding with expression changes of the ET- and SA-responsive genes TaPIE1 and TaPR1.1. In contrast, the expression level of the jasmonic acid (JA)-responsive gene TaAOS was not affected by TaWRKY70. These results indicate that TaWRKY70 is positively involved in HTSP resistance, during which SA and ET signalling are probably activated. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Tuning the effective parameters in (Ta/Cu/[Ni/Co]x/Ta) multilayers with perpendicular magnetic anisotropy

NASA Astrophysics Data System (ADS)

Ayareh, Zohreh; Moradi, Mehrdad; Mahmoodi, Saman

2018-06-01

In this paper, we report perpendicular magnetic anisotropy (PMA) in a (Ta/Cu/[Ni/Co]x/Ta) multilayers structure. These typical structures usually include a multilayer of ferromagnetic and transition metal thin films. Usually, magnetic anisotropy is characterized by magnetization loops determined by magnetometer or magneto-optical Kerr effect (MOKE). The interface between ferromagnetic and metallic layers plays an important role in magnetic anisotropy evolution from out-of-plane to in-plane in (Ta/Cu/[Ni/Co]/Ta) structure. Obtained results from MOKE and magnetometry of these samples show that they have different easy axes due to change in thickness of Cu as spacer layer and difference in number of repetition of [Ni/Co] stacks.

Characterization of a common wheat (Triticum aestivum L.) TaSnRK2.7 gene involved in abiotic stress responses

PubMed Central

Zhang, Hongying; Mao, Xinguo; Jing, Ruilian; Chang, Xiaoping; Xie, Huimin

2011-01-01

Sucrose non-fermenting-1-related protein kinase 2 (SnRK2) plays a key role in the plant stress signalling transduction pathway via phosphorylation. Here, a SnRK2 member of common wheat, TaSnRK2.7, was cloned and characterized. Southern blot analysis suggested that the common wheat genome contains three copies of TaSnRK2.7. Subcellular localization showed the presence of TaSnRK2.7 in the cell membrane, cytoplasm, and nucleus. Expression patterns revealed that TaSnRK2.7 is expressed strongly in roots, and responds to polyethylene glycol, NaCl, and cold stress, but not to abscisic acid (ABA) application, suggesting that TaSnRK2.7 might participate in non-ABA-dependent signal transduction pathways. TaSnRK2.7 was transferred to Arabidopsis under the control of the CaMV-35S promoter. Function analysis showed that TaSnRK2.7 is involved in carbohydrate metabolism, decreasing osmotic potential, enhancing photosystem II activity, and promoting root growth. Its overexpression results in enhanced tolerance to multi-abiotic stress. Therefore, TaSnRK2.7 is a multifunctional regulatory factor in plants, and has the potential to be utilized in transgenic breeding to improve abiotic stress tolerance in crop plants. PMID:21030389

Electronic structure and optical properties of Ta-doped and (Ta, N)-codoped SrTiO3 from hybrid functional calculations

NASA Astrophysics Data System (ADS)

Liu, Yanyu; Zhou, Wei; Wu, Ping

2017-02-01

A systematic study has been carried out to research the effect of Ta monodoping and (Ta, N)-codoping on the electronic structure and optical properties of SrTiO3. The results indicate that the incorporation of N into the SrTiO3 lattice is in favor of the substitution of Ta at a Ti site, which is the most favorable structure with respect to both the energetic stability and high photocatalytic activity. Furthermore, the carrier recombination centers induced by Ta monodoping are passivated in the (Ta, N)-codoped SrTiO3 system with Ta at a Ti site. Simultaneous incorporation of N and Ta results in a band gap decreasing about 0.7 eV due to the appearance of the new states hybridized by N-p states with the O-p states above the valence band. The band alignment verifies that the (Ta, N)-codoped SrTiO3 simultaneously meets the criteria of band-edge energetic positions and band gap for the overall water splitting under visible light.

TaNAC29, a NAC transcription factor from wheat, enhances salt and drought tolerance in transgenic Arabidopsis.

PubMed

Huang, Quanjun; Wang, Yan; Li, Bin; Chang, Junli; Chen, Mingjie; Li, Kexiu; Yang, Guangxiao; He, Guangyuan

2015-11-04

NAC (NAM, ATAF, and CUC) transcription factors play important roles in plant biological processes, including phytohormone homeostasis, plant development, and in responses to various environmental stresses. TaNAC29 was introduced into Arabidopsis using the Agrobacterium tumefaciens-mediated floral dipping method. TaNAC29-overexpression plants were subjected to salt and drought stresses for examining gene functions. To investigate tolerant mechanisms involved in the salt and drought responses, expression of related marker genes analyses were conducted, and related physiological indices were also measured. Expressions of genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). A novel NAC transcription factor gene, designated TaNAC29, was isolated from bread wheat (Triticum aestivum). Sequence alignment suggested that TaNAC29 might be located on chromosome 2BS. TaNAC29 was localized to the nucleus in wheat protoplasts, and proved to have transcriptional activation activities in yeast. TaNAC29 was expressed at a higher level in the leaves, and expression levels were much higher in senescent leaves, indicating that TaNAC29 might be involved in the senescence process. TaNAC29 transcripts were increased following treatments with salt, PEG6000, H2O2, and abscisic acid (ABA). To examine TaNAC29 function, transgenic Arabidopsis plants overexpressing TaNAC29 were generated. Germination and root length assays of transgenic plants demonstrated that TaNAC29 overexpression plants had enhanced tolerances to high salinity and dehydration, and exhibited an ABA-hypersensitive response. When grown in the greenhouse, TaNAC29-overexpression plants showed the same tolerance response to salt and drought stresses at both the vegetative and reproductive period, and had delayed bolting and flowering in the reproductive period. Moreover, TaNAC29 overexpression plants accumulated lesser malondialdehyde (MDA), H2O2, while had higher superoxide dismutase (SOD) and

O-GlcNAc-mediated interaction between VER2 and TaGRP2 elicits TaVRN1 mRNA accumulation during vernalization in winter wheat

PubMed Central

Xiao, Jun; Xu, Shujuan; Li, Chunhua; Xu, Yunyuan; Xing, Lijing; Niu, Yuda; Huan, Qing; Tang, Yimiao; Zhao, Changping; Wagner, Doris; Gao, Caixia; Chong, Kang

2014-01-01

Vernalization, sensing of prolonged cold, is important for seasonal flowering in eudicots and monocots. While vernalization silences a repressor (FLC, MADS-box transcription factor) in eudicots, it induces an activator (TaVRN1, an AP1 clade MADS-box transcription factor) in monocots. The mechanism for TaVRN1 induction during vernalization is not well understood. Here we reveal a novel mechanism for controlling TaVRN1 mRNA accumulation in response to prolonged cold sensing in wheat. The carbohydrate-binding protein VER2, a jacalin lectin, promotes TaVRN1 upregulation by physically interacting with the RNA-binding protein TaGRP2. TaGRP2 binds to TaVRN1 pre-mRNA and inhibits TaVRN1 mRNA accumulation. The physical interaction between VER2 and TaGRP2 is controlled by TaGRP2 O-GlcNAc modification, which gradually increases during vernalization. The interaction between VER2 and O-GlcNAc-TaGRP2 reduces TaGRP2 protein accumulation in the nucleus and/or promotes TaGRP2 dissociation from TaVRN1, leading to TaVRN1 mRNA accumulation. Our data reveal a new mechanism for sensing prolonged cold in temperate cereals. PMID:25091017

Superstructure Ta2O5 mesocrystals derived from (NH4)2Ta2O3F6 mesocrystals with efficient photocatalytic activity.

PubMed

Yu, Xin; Li, Wei; Huang, Jian; Li, Zhonghua; Liu, Jiawen; Hu, PingAn

2018-02-06

Superstructured mesocrystalline Ta 2 O 5 nanosheets were successfully prepared from mesocrystalline (NH 4 ) 2 Ta 2 O 3 F 6 nanorods by the annealing method for the first time. The as-prepared mesocrystalline Ta 2 O 5 nanosheets in this work showed remarkable visible light absorption, mainly due to the formation of oxygen vacancy defects in the mesocrystalline Ta 2 O 5 nanosheets, which was also confirmed by XPS spectra, Raman spectra and EPR spectra. Besides, the mesocrystalline Ta 2 O 5 nanosheets showed a highly enhanced photocatalytic activity of 11 268.24 μmol g -1 h -1 , about 3.95 times that of commercial Ta 2 O 5 . Moreover, the specific surface area of the mesocrystalline Ta 2 O 5 -800 nanosheets was 16.34 m 2 g -1 , about 5.32 times that of the commercial Ta 2 O 5 (3.072 m 2 g -1 ). The valence band XPS spectra indicated a strong oxidizing ability of the mesocrystalline Ta 2 O 5 nanosheets in comparison to that of commercial Ta 2 O 5 . The formation of superstructured Ta 2 O 5 mesocrystals generated long lifetime carriers and effective conduction pathways, which greatly enhanced the photocatalytic activity for hydrogen production.

Fermi surface interconnectivity and topology in Weyl fermion semimetals TaAs, TaP, NbAs, and NbP

DOE PAGES

Lee, Chi-Cheng; Xu, Su-Yang; Huang, Shin-Ming; ...

2015-12-01

The family of binary compounds including TaAs, TaP, NbAs, and NbP was recently discovered as the first realization of Weyl semimetals. In order to develop a comprehensive description of the charge carriers in these Weyl semimetals, we performed detailed and systematic electronic band structure calculations which reveal the nature of Fermi surfaces and their complex interconnectivity in TaAs, TaP, NbAs, and NbP. In conclusion, our work reports a comparative and comprehensive study of Fermi surface topology and band structure details of all known members of the Weyl semimetal family and hence provides the fundamental knowledge for realizing the many predictedmore » exotic topological quantum physics of Weyl semimetals based on the TaAs class of materials.« less

Effects of various chemical compounds on spontaneous and hydrogen peroxide-induced reversion in strain TA104 of Salmonella typhimurium.

PubMed

Han, J S

1992-04-01

In experiments designed to determine which active oxygen species contribute to hydrogen peroxide (HP)-induced reversion in strain TA104 of Salmonella typhimurium, 1,10-phenanthroline (an iron chelator, which prevents the formation of hydroxyl radicals from HP and DNA-bound iron by the Fenton reaction), sodium azide (a singlet oxygen scavenger), and potassium iodide (an hydroxyl radical scavenger) inhibited HP-induced reversion. These results indicate that hydroxyl radicals generated from HP by the Fenton reaction, and perhaps singlet oxygen, contribute to HP-induced reversion in TA104. However, reduced glutathione (reduces Fe3+ to Fe2+ and/or HP to water), diethyldithiocarbamic acid (an inhibitor of superoxide dismutase), diethyl maleate (a glutathione scavenger), and 3-amino-1,2,4-triazole (an inhibitor of catalase) did not inhibit HP-induced reversion in TA104. Thus, superoxide radical anions and HP itself do not appear to be the cause of HP-induced reversion in this strain. In experiments on the effect of 5 common dietary compounds (beta-carotene, retinoic acid, and vitamins A, C and E), chlorophyllin (CHL), and ergothioneine, the frequency of revertants in TA104 increased above the spontaneous frequency in the presence of beta-carotene or vitamin C (about 2-fold) or vitamin A (about 3-fold). The 5 dietary antimutagens and CHL did not inhibit HP-induced reversion in TA104. However, L-ergothioneine inhibited HP-induced reversion in this strain. Therefore, it is likely that L-ergothioneine is a scavenger of hydroxyl radicals or an inhibitor of their formation, and perhaps of singlet oxygen, at the concentrations tested in TA104.

Retention Model of TaO/HfO x and TaO/AlO x RRAM with Self-Rectifying Switch Characteristics.

PubMed

Lin, Yu-De; Chen, Pang-Shiu; Lee, Heng-Yuan; Chen, Yu-Sheng; Rahaman, Sk Ziaur; Tsai, Kan-Hsueh; Hsu, Chien-Hua; Chen, Wei-Su; Wang, Pei-Hua; King, Ya-Chin; Lin, Chrong Jung

2017-12-01

A retention behavior model for self-rectifying TaO/HfO x - and TaO/AlO x -based resistive random-access memory (RRAM) is proposed. Trapping-type RRAM can have a high resistance state (HRS) and a low resistance state (LRS); the degradation in a LRS is usually more severe than that in a HRS, because the LRS during the SET process is limited by the internal resistor layer. However, if TaO/AlO x elements are stacked in layers, the LRS retention can be improved. The LRS retention time estimated by extrapolation method is more than 5 years at room temperature. Both TaO/HfO x - and TaO/AlO x -based RRAM structures have the same capping layer of TaO, and the activation energy levels of both types of structures are 0.38 eV. Moreover, the additional AlO x switching layer of a TaO/AlO x structure creates a higher O diffusion barrier that can substantially enhance retention, and the TaO/AlO x structure also shows a quite stable LRS under biased conditions.

Resonances in odd-odd 182Ta

NASA Astrophysics Data System (ADS)

Brits, C. P.; Wiedeking, M.; Bello Garrote, F. L.; Bleuel, D. L.; Giacoppo, F.; Görgen, A.; Guttormsen, M.; Hadynska-Klek, K.; Hagen, T. W.; Ingeberg, V. W.; Kheswa, B. V.; Klintefjord, M.; Larsen, A. C.; Malatji, K. L.; Nyhus, H. T.; Papka, P.; Renstrøm, T.; Rose, S.; Sahin, E.; Siem, S.; Tveten, G. M.; Zeiser, F.

2017-09-01

Enhanced γ-decay on the tail of the giant electric dipole resonance, such as the scissors or pygmy resonances, can have significant impact on (n,γ) reaction rates. These rates are important input for modeling processes that take place in astrophysical environments and nuclear reactors. Recent results from the University of Oslo indicate the existence of a significant enhancement in the photon strength function for nuclei in the actinide region due to the scissors resonance. Further, the M1 strength distribution of the scissors resonances in rare earth nuclei has been studied extensively over the years. To investigate the evolution and persistence of the scissor resonance in other mass regions, an experiment was performed utilizing the NaI(Tl) γ-ray detector array (CACTUS) and silicon particle telescopes (SiRi) at the University of Oslo Cyclotron laboratory. Particle-γ coincidences from the 181Ta(d,p)182Ta and 181Ta(d,d')181Ta reactions were used to measure the nuclear level density and photon strength function of the well-deformed 181Ta and 182Ta systems, to investigate the existence of resonances below the neutron separation energy. Note to the reader: the title of this article has been corrected on September 19, 2017.

STUDY ON SYNTHESIS AND EVOLUTION OF NANOCRYSTALLINE Mg4Ta2O9 BY AQUEOUS SOL-GEL PROCESS

NASA Astrophysics Data System (ADS)

Wu, H. T.; Yang, C. H.; Wu, W. B.; Yue, Y. L.

2012-06-01

Nanosized and highly reactive Mg4Ta2O9 were successfully synthesized by aqueous sol-gel method compared with conventional solid-state method. Ta-Mg-citric acid solution was first formed and then evaporated resulting in a dry gel for calcination in the temperature ranging from 600°C to 800°C for crystallization in oxygen atmosphere. The crystallization process from the gel to crystalline Mg4Ta2O9 was identified by thermal analysis and phase evolution of powders was studied using X-ray diffraction (XRD) technique during calcinations. Particle size and morphology were examined by transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HR-SEM). The results revealed that sol-gel process showed great advantages over conventional solid-state method and Mg4Ta2O9 nanopowders with the size of 20-30 nm were obtained at 800°C.

75 FR 43564 - TA-W-71,483, Continental Airlines, Inc., Reservations Division, Houston, TX; TA-W-71,483A...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-26

... DEPARTMENT OF LABOR Employment and Training Administration TA-W-71,483, Continental Airlines, Inc., Reservations Division, Houston, TX; TA-W-71,483A, Continental Airlines, Inc., Reservations Division, Tampa, FL; TA-W-71,483B, Continental Airlines, Inc., Reservations Division, Salt Lake City, UT; Notice of Negative Determination Regarding...

The Triticum aestivum non-specific lipid transfer protein (TaLtp) gene family: comparative promoter activity of six TaLtp genes in transgenic rice.

PubMed

Boutrot, Freddy; Meynard, Donaldo; Guiderdoni, Emmanuel; Joudrier, Philippe; Gautier, Marie-Françoise

2007-03-01

Plant non-specific lipid transfer proteins (nsLTPs) are encoded by a multigene family and support physiological functions, which remain unclear. We adapted an efficient ligation-mediated polymerase chain reaction (LM-PCR) procedure that enabled isolation of 22 novel Triticum aestivum nsLtp (TaLtp) genes encoding types 1 and 2 nsLTPs. A phylogenetic tree clustered the wheat nsLTPs into ten subfamilies comprising 1-7 members. We also studied the activity of four type 1 and two type 2 TaLtp gene promoters in transgenic rice using the 1-Glucuronidase reporter gene. The activities of the six promoters displayed both overlapping and distinct features in rice. In vegetative organs, these promoters were active in leaves and root vascular tissues while no beta-Glucuronidase (GUS) activity was detected in stems. In flowers, the GUS activity driven by the TaLtp7.2a, TaLtp9.1a, TaLtp9.2d, and TaLtp9.3e gene promoters was associated with vascular tissues in glumes and in the extremities of anther filaments whereas only the TaLtp9.4a gene promoter was active in anther epidermal cells. In developing grains, GUS activity and GUS immunolocalization data evidenced complex patterns of activity of the TaLtp7.1a, TaLtp9.2d, and TaLtp9.4a gene promoters in embryo scutellum and in the grain epicarp cell layer. In contrast, GUS activity driven by TaLtp7.2a, TaLtp9.1a, and TaLtp9.3e promoters was restricted to the vascular bundle of the embryo scutellum. This diversity of TaLtp gene promoter activity supports the hypothesis that the encoded TaLTPs possess distinct functions in planta.

TaCPK2-A, a calcium-dependent protein kinase gene that is required for wheat powdery mildew resistance enhances bacterial blight resistance in transgenic rice.

PubMed

Geng, Shuaifeng; Li, Aili; Tang, Lichuan; Yin, Lingjie; Wu, Liang; Lei, Cailin; Guo, Xiuping; Zhang, Xin; Jiang, Guanghuai; Zhai, Wenxue; Wei, Yuming; Zheng, Youliang; Lan, Xiujin; Mao, Long

2013-08-01

Calcium-dependent protein kinases (CPKs) are important Ca2+ signalling components involved in complex immune and stress signalling networks; but the knowledge of CPK gene functions in the hexaploid wheat is limited. Previously, TaCPK2 was shown to be inducible by powdery mildew (Blumeria graminis tritici, Bgt) infection in wheat. Here, its functions in disease resistance are characterized further. This study shows the presence of defence-response and cold-response cis-elements on the promoters of the A subgenome homoeologue (TaCPK2-A) and D subgenome homoeologue (TaCPK2-D), respectively. Their expression patterns were then confirmed by quantitative real-time PCR (qRT-PCR) using genome-specific primers, where TaCPK2-A was induced by Bgt treatment while TaCPK2-D mainly responded to cold treatment. Downregulation of TaCPK2-A by virus-induced gene silencing (VIGS) causes loss of resistance to Bgt in resistant wheat lines, indicating that TaCPK2-A is required for powdery mildew resistance. Furthermore, overexpression of TaCPK2-A in rice enhanced bacterial blight (Xanthomonas oryzae pv. oryzae, Xoo) resistance. qRT-PCR analysis showed that overexpression of TaCPK2-A in rice promoted the expression of OsWRKY45-1, a transcription factor involved in both fungal and bacterial resistance by regulating jasmonic acid and salicylic acid signalling genes. The opposite effect was found in wheat TaCPK2-A VIGS plants, where the homologue of OsWRKY45-1 was significantly repressed. These data suggest that modulation of WRKY45-1 and associated defence-response genes by CPK2 genes may be the common mechanism for multiple disease resistance in grass species, which may have undergone subfunctionalization in promoters before the formation of hexaploid wheat.

TaCPK2-A, a calcium-dependent protein kinase gene that is required for wheat powdery mildew resistance enhances bacterial blight resistance in transgenic rice

PubMed Central

Geng, Shuaifeng; Li, Aili; Tang, Lichuan; Lan, Xiujin; Mao, Long

2013-01-01

Calcium-dependent protein kinases (CPKs) are important Ca2+ signalling components involved in complex immune and stress signalling networks; but the knowledge of CPK gene functions in the hexaploid wheat is limited. Previously, TaCPK2 was shown to be inducible by powdery mildew (Blumeria graminis tritici, Bgt) infection in wheat. Here, its functions in disease resistance are characterized further. This study shows the presence of defence-response and cold-response cis-elements on the promoters of the A subgenome homoeologue (TaCPK2-A) and D subgenome homoeologue (TaCPK2-D), respectively. Their expression patterns were then confirmed by quantitative real-time PCR (qRT-PCR) using genome-specific primers, where TaCPK2-A was induced by Bgt treatment while TaCPK2-D mainly responded to cold treatment. Downregulation of TaCPK2-A by virus-induced gene silencing (VIGS) causes loss of resistance to Bgt in resistant wheat lines, indicating that TaCPK2-A is required for powdery mildew resistance. Furthermore, overexpression of TaCPK2-A in rice enhanced bacterial blight (Xanthomonas oryzae pv. oryzae, Xoo) resistance. qRT-PCR analysis showed that overexpression of TaCPK2-A in rice promoted the expression of OsWRKY45-1, a transcription factor involved in both fungal and bacterial resistance by regulating jasmonic acid and salicylic acid signalling genes. The opposite effect was found in wheat TaCPK2-A VIGS plants, where the homologue of OsWRKY45-1 was significantly repressed. These data suggest that modulation of WRKY45-1 and associated defence-response genes by CPK2 genes may be the common mechanism for multiple disease resistance in grass species, which may have undergone subfunctionalization in promoters before the formation of hexaploid wheat. PMID:23918959

ABI-like transcription factor gene TaABL1 from wheat improves multiple abiotic stress tolerances in transgenic plants.

PubMed

Xu, Dong-Bei; Gao, Shi-Qing; Ma, You-Zhi; Xu, Zhao-Shi; Zhao, Chang-Ping; Tang, Yi-Miao; Li, Xue-Yin; Li, Lian-Cheng; Chen, Yao-Feng; Chen, Ming

2014-12-01

The phytohormone abscisic acid (ABA) plays crucial roles in adaptive responses of plants to abiotic stresses. ABA-responsive element binding proteins (AREBs) are basic leucine zipper transcription factors that regulate the expression of downstream genes containing ABA-responsive elements (ABREs) in promoter regions. A novel ABI-like (ABA-insensitive) transcription factor gene, named TaABL1, containing a conserved basic leucine zipper (bZIP) domain was cloned from wheat. Southern blotting showed that three copies were present in the wheat genome. Phylogenetic analyses indicated that TaABL1 belonged to the AREB subfamily of the bZIP transcription factor family and was most closely related to ZmABI5 in maize and OsAREB2 in rice. Expression of TaABL1 was highly induced in wheat roots, stems, and leaves by ABA, drought, high salt, and low temperature stresses. TaABL1 was localized inside the nuclei of transformed wheat mesophyll protoplast. Overexpression of TaABL1 enhanced responses of transgenic plants to ABA and hastened stomatal closure under stress, thereby improving tolerance to multiple abiotic stresses. Furthermore, overexpression of TaABL1 upregulated or downregulated the expression of some stress-related genes controlling stomatal closure in transgenic plants under ABA and drought stress conditions, suggesting that TaABL1 might be a valuable genetic resource for transgenic molecular breeding.

Pre-Test Analysis Predictions for the Shell Buckling Knockdown Factor Checkout Tests - TA01 and TA02

NASA Technical Reports Server (NTRS)

Thornburgh, Robert P.; Hilburger, Mark W.

2011-01-01

This report summarizes the pre-test analysis predictions for the SBKF-P2-CYL-TA01 and SBKF-P2-CYL-TA02 shell buckling tests conducted at the Marshall Space Flight Center (MSFC) in support of the Shell Buckling Knockdown Factor (SBKF) Project, NASA Engineering and Safety Center (NESC) Assessment. The test article (TA) is an 8-foot-diameter aluminum-lithium (Al-Li) orthogrid cylindrical shell with similar design features as that of the proposed Ares-I and Ares-V barrel structures. In support of the testing effort, detailed structural analyses were conducted and the results were used to monitor the behavior of the TA during the testing. A summary of predicted results for each of the five load sequences is presented herein.

TA-55 change control manual

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

Blum, T.W.; Selvage, R.D.; Courtney, K.H.

This manual is the guide for initiating change at the Plutonium Facility, which handles the processing of plutonium as well as research on plutonium metallurgy. It describes the change and work control processes employed at TA-55 to ensure that all proposed changes are properly identified, reviewed, approved, implemented, tested, and documented so that operations are maintained within the approved safety envelope. All Laboratory groups, their contractors, and subcontractors doing work at TA-55 follow requirements set forth herein. This manual applies to all new and modified processes and experiments inside the TA-55 Plutonium Facility; general plant project (GPP) and line itemmore » funded construction projects at TA-55; temporary and permanent changes that directly or indirectly affect structures, systems, or components (SSCs) as described in the safety analysis, including Facility Control System (FCS) software; and major modifications to procedures. This manual does not apply to maintenance performed on process equipment or facility SSCs or the replacement of SSCs or equipment with documented approved equivalents.« less

Molecular Characterization of TaFAR1 Involved in Primary Alcohol Biosynthesis of Cuticular Wax in Hexaploid Wheat.

PubMed

Wang, Yong; Wang, Meiling; Sun, Yulin; Hegebarth, Daniela; Li, Tingting; Jetter, Reinhard; Wang, Zhonghua

2015-10-01

Cuticular waxes are complex mixtures of very long chain (VLC) fatty acids and their derivatives in which primary alcohols are the most abundant components in the leaf surface of common wheat (Triticum aestivum L.). However, the genes involved in primary alcohol biosynthesis in wheat are still largely unknown. Here we identified, via a homology-based approach, the TaFAR1 gene belonging to the fatty acyl-CoA reductases (FARs) from wheat. Heterologous expression of TaFAR1 in yeast (Saccharomyces cerevisiae) and in the Arabidopsis (Arabidopsis thaliana) cer4-3 mutant afforded production of C22 primary alcohol and C22-C24 primary alcohols, respectively, and transgenic expression of TaFAR1 in tomato (Solanum lycopersicum) cv MicroTom leaves and fruits resulted in the accumulation of C26-C30 primary alcohols and C30-C34 primary alcohols, respectively. The TaFAR1 protein was localized to the endoplasmic reticulum (ER) in rice (Oryza sativa L.) leaf protoplasts. Moreover, the TaFAR1 expression pattern across various organs correlated with the levels of primary alcohols accumulating in corresponding waxes, and with the presence of platelet-shaped epicuticular wax crystals formed by primary alcohols. A nullisomic-tetrasomic wheat line lacking TaFAR1 had significantly reduced levels of primary alcohols in its leaf blade and anther wax. TaFAR1 was located on chromosome 4AL and appeared to be highly conserved, with only one haplotype among 32 wheat cultivars. Finally, TaFAR1 expression was induced by drought and cold stress in an ABA-dependent manner. Taken together, our results show that TaFAR1 is an active enzyme forming primary alcohols destined for the wheat cuticle. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Preparation and in vitro/in vivo characterization of porous sublingual tablets containing ternary kneaded solid system of vinpocetine with î-cyclodextrin and hydroxy Acid.

PubMed

Aburahma, Mona H; El-Laithy, Hanan M; Hamza, Yassin El-Said

2010-01-01

The demand for sublingual tablets has been growing during the previous decades especially for drugs with extensive hepatic first-pass metabolism. Vinpocetine, a widely used neurotropic agent, has low oral bioavailability due to its poor aqueous solubility and marked first-pass metabolism. Accordingly, the aim of this work was to develop tablets for the sublingual delivery of vinpocetine. Initially, the feasibility of improving vinpocetineâs poor aqueous solubility by preparing kneaded solid systems of the drug with Î-Cyclodextrin and hydroxy acids (citric acid and tartaric acid) was assessed. The solid system with improved solubility and dissolution properties was incorporated into porous tablets that rapidly disintegrate permitting fast release of vinpocetine into the sublingual cavity. The pores were induced into these tablets by directly compressing the tabletsâ excipients with a sublimable material, either camphor or menthol, which was eventually sublimated leaving pores. The obtained results demonstrated that the tablets prepared using camphor attained sufficient mechanical strength for practical use together with rapid disintegration and dissolution. In vivo absorption study performed in rabbits indicated that the sublingual administration of the proposed porous tablets containing vinpocetine solid system with Î-Cyclodextrin and tartaric acid could be useful for therapeutic application.

Preparation and In Vitro/In Vivo Characterization of Porous Sublingual Tablets Containing Ternary Kneaded Solid System of Vinpocetine with β-Cyclodextrin and Hydroxy Acid

PubMed Central

Aburahma, Mona H.; El-Laithy, Hanan M.; Hamza, Yassin El-Said

2010-01-01

The demand for sublingual tablets has been growing during the previous decades especially for drugs with extensive hepatic first-pass metabolism. Vinpocetine, a widely used neurotropic agent, has low oral bioavailability due to its poor aqueous solubility and marked first-pass metabolism. Accordingly, the aim of this work was to develop tablets for the sublingual delivery of vinpocetine. Initially, the feasibility of improving vinpocetine’s poor aqueous solubility by preparing kneaded solid systems of the drug with β-Cyclodextrin and hydroxy acids (citric acid and tartaric acid) was assessed. The solid system with improved solubility and dissolution properties was incorporated into porous tablets that rapidly disintegrate permitting fast release of vinpocetine into the sublingual cavity. The pores were induced into these tablets by directly compressing the tablets’ excipients with a sublimable material, either camphor or menthol, which was eventually sublimated leaving pores. The obtained results demonstrated that the tablets prepared using camphor attained sufficient mechanical strength for practical use together with rapid disintegration and dissolution. In vivo absorption study performed in rabbits indicated that the sublingual administration of the proposed porous tablets containing vinpocetine solid system with β-Cyclodextrin and tartaric acid could be useful for therapeutic application. PMID:21179352

Heterologous expression of wheat VERNALIZATION 2 (TaVRN2) gene in Arabidopsis delays flowering and enhances freezing tolerance.

PubMed

Diallo, Amadou; Kane, Ndjido; Agharbaoui, Zahra; Badawi, Mohamed; Sarhan, Fathey

2010-01-13

The vernalization gene 2 (VRN2), is a major flowering repressor in temperate cereals that is regulated by low temperature and photoperiod. Here we show that the gene from Triticum aestivum (TaVRN2) is also regulated by salt, heat shock, dehydration, wounding and abscissic acid. Promoter analysis indicates that TaVRN2 regulatory region possesses all the specific responsive elements to these stresses. This suggests pleiotropic effects of TaVRN2 in wheat development and adaptability to the environment. To test if TaVRN2 can act as a flowering repressor in species different from the temperate cereals, the gene was ectopically expressed in the model plant Arabidopsis. Transgenic plants showed no alteration in morphology, but their flowering time was significantly delayed compared to controls plants, indicating that TaVRN2, although having no ortholog in Brassicaceae, can act as a flowering repressor in these species. To identify the possible mechanism by which TaVRN2 gene delays flowering in Arabidopsis, the expression level of several genes involved in flowering time regulation was determined. The analysis indicates that the late flowering of the 35S::TaVRN2 plants was associated with a complex pattern of expression of the major flowering control genes, FCA, FLC, FT, FVE and SOC1. This suggests that heterologous expression of TaVRN2 in Arabidopsis can delay flowering by modulating several floral inductive pathways. Furthermore, transgenic plants showed higher freezing tolerance, likely due to the accumulation of CBF2, CBF3 and the COR genes. Overall, our data suggests that TaVRN2 gene could modulate a common regulator of the two interacting pathways that regulate flowering time and the induction of cold tolerance. The results also demonstrate that TaVRN2 could be used to manipulate flowering time and improve cold tolerance in other species.

Fabrication of electrocatalytic Ta nanoparticles by reactive sputtering and ion soft landing.

PubMed

Johnson, Grant E; Moser, Trevor; Engelhard, Mark; Browning, Nigel D; Laskin, Julia

2016-11-07

About 40 years ago, it was shown that tungsten carbide exhibits similar catalytic behavior to Pt for certain commercially relevant reactions, thereby suggesting the possibility of cheaper and earth-abundant substitutes for costly and rare precious metal catalysts. In this work, reactive magnetron sputtering of Ta in the presence of three model hydrocarbons (2-butanol, heptane, and m-xylene) combined with gas aggregation and ion soft landing was employed to prepare organic-inorganic hybrid nanoparticles (NPs) on surfaces for evaluation of catalytic activity and durability. The electrocatalytic behavior of the NPs supported on glassy carbon was evaluated in acidic aqueous solution by cyclic voltammetry. The Ta-heptane and Ta-xylene NPs were revealed to be active and robust toward promotion of the oxygen reduction reaction, an important process occurring at the cathode in fuel cells. In comparison, pure Ta and Ta-butanol NPs were essentially unreactive. Characterization techniques including atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were applied to probe how different sputtering conditions such as the flow rates of gases, sputtering current, and aggregation length affect the properties of the NPs. AFM images reveal the focused size of the NPs as well as their preferential binding along the step edges of graphite surfaces. In comparison, TEM images of the same NPs on carbon grids show that they bind randomly to the surface with some agglomeration but little coalescence. The TEM images also reveal morphologies with crystalline cores surrounded by amorphous regions for NPs formed in the presence of 2-butanol and heptane. In contrast, NPs formed in the presence of m-xylene are amorphous throughout. XPS spectra indicate that while the percentage of Ta, C, and O in the NPs varies depending on the sputtering conditions and hydrocarbon employed, the electron binding energies of the elements are similar for

Scaling of anomalous Hall effect in Ta/CoFeB/MgAl2O4/Ta multilayers

NASA Astrophysics Data System (ADS)

Wu, Yong; Zhang, Qimeng; Meng, Kangkang; Chen, Jikun; Xu, Xiaoguang; Miao, Jun; Jiang, Yong

2017-06-01

The anomalous Hall effect (AHE) is studied in Ta/CoFeB/MgAl2O4/Ta multilayers with different thicknesses of MgAl2O4 (t), which causes in-plane magnetic anisotropy (IMA) for t = 1.0 nm and perpendicular magnetic anisotropy (PMA) for t ≥ 1.2 nm. Conventional scaling was demonstrated to be not inadequate in our case. The origin of the AHE in Ta/CoFeB/MgAl2O4/Ta multilayers is mainly an extrinsic mechanism. The contribution of skew scattering (SS) is unneglectable, and both the SS and side jump are enhanced when the magnetic anisotropy changes from IMA to PMA, indicating that the oxidation at the interface of CoFeB/MgAl2O4 has a dominant influence on the AHE.

Photocatalytic ozonation of terephthalic acid: a by-product-oriented decomposition study.

PubMed

Fuentes, Iliana; Rodríguez, Julia L; Poznyak, Tatyana; Chairez, Isaac

2014-11-01

Terephthalic acid (TA) is considered as a refractory model compound. For this reason, the TA degradation usually requires a prolonged reaction time to achieve mineralization. In this study, vanadium oxide (VxOy) supported on titanium oxide (TiO2) served as a photocatalyst in the ozonation of the TA with light-emitting diodes (LEDs), having a bandwidth centered at 452 nm. The modified catalyst (VxOy/TiO2) in combination with ozone and LEDs improved the TA degradation and its by-products. The results obtained by this system were compared with photolysis, single ozonation, catalytic ozonation, and photocatalytic ozonation of VxOy/TiO2 with UV lamp. The LED-based photocatalytic ozonation showed almost the same decomposition efficiency of the TA, but it was better in comparison with the use of UV lamp. The oxalic acid accumulation, as the final product of the TA decomposition, was directly influenced by either the presence of VxOy or/and the LED irradiation. Several by-products formed during the TA degradation, such as muconic, fumaric, and oxalic acids, were identified. Besides, two unidentified by-products were completely removed during the observed time (60 min). It was proposed that the TA elimination in the presence of VxOy/TiO2 as catalyst was carried out by the combination of different mechanisms: molecular ozone reaction, indirect mechanism conducted by ·OH, and the surface complex formation.

Cloning and characterization of a calcium binding EF-hand protein gene TaCab1 from wheat and its expression in response to Puccinia striiformis f. sp. tritici and abiotic stresses.

PubMed

Feng, Hao; Wang, Xiaomin; Sun, Yanfei; Wang, Xiaojie; Chen, Xianming; Guo, Jun; Duan, Yinghui; Huang, Lili; Kang, Zhensheng

2011-08-01

Calcium is a ubiquitous and essential secondary messenger in eukaryotic signal transduction pathways. Calcium binding protein, as a component of pathways, plays various roles in response to biotic and abiotic stresses, as well as in developmental processes in plants. In this study, a calcium binding protein gene, designated as TaCab1 (Triticum aestivum calcium binding EF-hand protein 1), was isolated and characterized from wheat leaves (cv. Suwon 11) infected by Puccinia striiformis f. sp. tritici by in silico cloning and reverse transcription PCR (RT-PCR). TaCab1 did not have an intron and was predicted to encode a 216 amino acid protein which possesses an N-terminal region with a signal peptide, a transmembrane domain, an EF-hand motif and a caleosin domain. The results of transient assays with constructs of TaCab1 with green fluorescent protein (GFP) gene indicated that TaCab1 encodes a transmembrane protein. Quantitative real-time PCR (qRT-PCR) analyses revealed that TaCab1 was highly expressed in leaves than roots and stems. Although up-regulated expression profiles of TaCab1 were quite similar in both incompatible and compatible interactions, its transcript accumulation in the compatible interaction was much higher than in the incompatible interaction. The transcription of TaCab1 was also up-regulated at different degrees after treated by phytohormones [abscisic acid, benzyl adenine, ethylene, methyl jasmonate and salicylic acid (SA)] and stress stimuli [wounding, low temperature, polyethylene glycol and high salinity]. These results suggest that TaCab1 is involved in the plant-pathogen recognition, symptom development, and the basal tolerance to biotic and abiotic stresses through the SA signaling pathway.

Two transcription factors TaPpm1 and TaPpb1 co-regulate anthocyanin biosynthesis in purple pericarps of wheat

PubMed Central

Jiang, Wenhui; Liu, Tianxiang; Nan, Wenzhi; Jeewani, Diddugodage Chamila; Niu, Yanlu; Li, Chunlian; Shi, Xue; Wang, Cong; Wang, Jiahuan; Li, Yang; Wang, Zhonghua

2018-01-01

Abstract Purple pericarps of bread wheat (Triticum aestivum L.) are a useful source of dietary anthocyanins. Previous mapping results indicated that the purple pericarp trait is controlled by two complementary genes located on chromosomes 7D and 2A. However, the identity of the genes and the mechanisms by which they regulate the trait are unknown. In this study, two transcription factors were characterised as anthocyanin activators in purple pericarps: TaPpm1 (purple pericarp-MYB 1) and TaPpb1 (purple pericarp-bHLH 1). Three non-functional variants were detected in the coding sequence of TaPpm1 from non-purple seed lines, in which the function of TaPpm1 was destroyed either by insertion-induced frame shifts or truncated peptides. There were six 261-bp tandem repeats in the promoter region of TaPpb1 in the purple-grained varieties, while there was only one repeat unit present in the non-purple varieties. Furthermore, using yeast two-hybrid, dual luciferase, yeast one-hybrid, and transient assays, we were able to demonstrate that the interaction of TaPpm1 and TaPpb1 co-regulates the synthesis of anthocyanin. Overall, our results provide a better understanding of the molecular basis of anthocyanin synthesis in the wheat pericarp and indicate the existence of an integrated regulatory mechanism that controls production. PMID:29562292

Overexpression of TaNAC2D Displays Opposite Responses to Abiotic Stresses between Seedling and Mature Stage of Transgenic Arabidopsis

PubMed Central

Huang, Quanjun; Wang, Yan

2016-01-01

Environmental stresses frequently affect plant growth and development, and many genes have been found to be induced by unfavorable environmental conditions. Here, we reported the biological functions of TaNAC2D, a stress-related NAC (NAM, ATAF, and CUC) gene from wheat. TaNAC2D showed transcriptional activator activity in yeast. TaNAC2D-GFP fusion protein was localized in the nucleus of wheat mesophyll protoplasts. TaNAC2D transcript abundance was significantly induced by NaCl, PEG6000, and abscisic acid (ABA) at seedling stage, and repressed by NaCl and PEG6000 at mature plant stage. When TaNAC2D was introduced into Arabidopsis, the 35-day-old soil-grown TaNAC2D-overexpression (TaNAC2D-OX) plants displayed slower stomatal closure, higher water loss rate, and more sensitivity to salt and drought stresses compared with WT plants. In contrast, TaNAC2D-OX seedlings, grown on 1/2 MS medium supplemented with different concentrations of NaCl, Mannitol, and MV, had enhanced tolerances to salt, osmotic and oxidative stresses during seed germination and post-germination periods. The opposite stress-responsive phenotypes of transgenic Arabidopsis were consistent with the expression patterns of TaNAC2D in wheat. Moreover, under high salinity and dehydration conditions, three marker genes, including NCED3, RD29A, and RD29B, were down-regulated in 35-day-old TaNAC2D-OX plants grown in soil and up-regulated in 14-day-old TaNAC2D-OX seedlings grown on 1/2 MS medium. Our results suggest that the change in growth stages and environmental conditions may regulate TaNAC2D’s function. PMID:27933076

The Wheat Mediator Subunit TaMED25 Interacts with the Transcription Factor TaEIL1 to Negatively Regulate Disease Resistance against Powdery Mildew.

PubMed

Liu, Jie; Zhang, Tianren; Jia, Jizeng; Sun, Jiaqiang

2016-03-01

Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici, is a major limitation for the production of bread wheat (Triticum aestivum). However, to date, the transcriptional regulation of bread wheat defense against powdery mildew remains largely unknown. Here, we report the function and molecular mechanism of the bread wheat Mediator subunit 25 (TaMED25) in regulating the bread wheat immune response signaling pathway. Three homoalleles of TaMED25 from bread wheat were identified and mapped to chromosomes 5A, 5B, and 5D, respectively. We show that knockdown of TaMED25 by barley stripe mosaic virus-induced gene silencing reduced bread wheat susceptibility to the powdery mildew fungus during the compatible plant-pathogen interaction. Moreover, our results indicate that MED25 may play a conserved role in regulating bread wheat and barley (Hordeum vulgare) susceptibility to powdery mildew. Similarly, bread wheat ETHYLENE INSENSITIVE3-LIKE1 (TaEIL1), an ortholog of Arabidopsis (Arabidopsis thaliana) ETHYLENE INSENSITIVE3, negatively regulates bread wheat resistance against powdery mildew. Using various approaches, we demonstrate that the conserved activator-interacting domain of TaMED25 interacts physically with the separate amino- and carboxyl-terminal regions of TaEIL1, contributing to the transcriptional activation activity of TaEIL1. Furthermore, we show that TaMED25 and TaEIL1 synergistically activate ETHYLENE RESPONSE FACTOR1 (TaERF1) transcription to modulate bread wheat basal disease resistance to B. graminis f. sp. tritici by repressing the expression of pathogenesis-related genes and deterring the accumulation of reactive oxygen species. Collectively, we identify the TaMED25-TaEIL1-TaERF1 signaling module as a negative regulator of bread wheat resistance to powdery mildew. © 2016 American Society of Plant Biologists. All Rights Reserved.

Efficiency of several leaching reagents on removal of Cu, Pb, Cd, and Zn from highly contaminated paddy soil.

PubMed

Gao, Ruili; Zhu, Pengfei; Guo, Guangguang; Hu, Hongqing; Zhu, Jun; Fu, Qingling

2016-11-01

The efficiency of five different single leaching reagents (tartaric acid (TA), citric acid (CA), CaCl 2 , FeCl 3 , EDTA) and two different composite leaching reagents (CA + FeCl 3 , CA + EDTA) on removing Cu, Pb, Zn, and Cd from contaminated paddy soil in Hunan Province (in China) was studied. The results indicated that the efficiencies of CA, FeCl 3 , and EDTA on extracting Cu, Pb, Cd, and Zn from soil were greater than that of TA and CaCl 2 , and their extraction efficiencies were EDTA ≥ FeCl 3 > CA. The efficiencies of CA + FeCl 3 on extracting Cu, Pb, Cd, and Zn were higher than that of single CA or FeCl 3 . The 25 mmol L -1 CA + 20 mmol L -1 FeCl 3 was a promising composite leaching reagent for paddy soil, and it could remove Cu (57.6 %), Pb (59.3 %), Cd (84.8 %), and Zn (28.0 %), respectively. With the same amount of leaching reagent, the efficiency of continuous leaching by several times was higher than that by once. In addition, the easily reducible and oxidizable fractions of heavy metals showed significant decrease during the process of leaching.

Structural and electronic investigations of PbTa4O11 and BiTa7O19 constructed from α-U3O8 types of layers

NASA Astrophysics Data System (ADS)

Boltersdorf, Jonathan; Maggard, Paul A.

2015-09-01

The PbTa4O11 and BiTa7O19 phases were prepared by ion-exchange and solid-state methods, respectively, and their structures were characterized by neutron time-of-flight diffraction and Rietveld refinement methods (PbTa4O11, R 3 (No. 146), a=6.23700(2) Å, c=36.8613(1) Å; BiTa7O19, P 6 bar c 2 (No. 188), a=6.2197(2) Å, c=20.02981(9) Å). Their structures are comprised of layers of TaO6 octahedra surrounded by three 7-coordinate Pb(II) cations or two 8-coordinate Bi(III) cations. These layers alternate down the c-axis with α-U3O8 types of single and double TaO7 pentagonal bipyramid layers. In contrast to earlier studies, both phases are found to crystallize in noncentrosymmetric structures. Symmetry-lowering structural distortions within PbTa4O11, i.e. R 3 bar c →R3, are found to be a result of the displacement of the Ta atoms within the TaO7 and TaO6 polyhedra, towards the apical and facial oxygen atoms, respectively. In BiTa7O19, relatively lower reaction temperatures leads to an ordering of the Bi/Ta cations within a lower-symmetry structure, i.e., P63/mcm→ P 6 bar c 2 . In the absence of Bi/Ta site disorder, the Ta-O-Ta bond angles decrease and the Ta-O bond distances increase within the TaO7 double layers. Scanning electron microscopy images reveal two particle morphologies for PbTa4O11, hexagonal rods and finer irregularly-shaped particles, while BiTa7O19 forms as aggregates of irregularly-shaped particles. Electronic-structure calculations confirm the highest-energy valence band states are comprised of O 2p-orbitals and the respective Pb 6s-orbital and Bi 6s-orbital contributions. The lowest-energy conduction band states are composed of Ta 5d-orbital contributions that are delocalized over the TaO6 octahedra and layers of TaO7 pentagonal bipyramids. The symmetry-lowering distortions in the PbTa4O11 structure, and the resulting effects on its electronic structure, lead to its relatively higher photocatalytic activity compared to similar structures without

Structure and Electrical Conductivity of AgTaS 3

NASA Astrophysics Data System (ADS)

Kim, Changkeun; Yun, Hoseop; Lee, Youngju; Shin, Heekyoon; Liou, Kwangkyoung

1997-09-01

Single crystals of the compound AgTaS 3have been prepared through reactions of the elements with halide mixtures. The structure of AgTaS 3has been analyzed by single-crystal X-ray diffraction methods. AgTaS 3crystallizes in the space group D172h- Cmcmof the orthorhombic system with four formula units in a cell of dimensions a=3.378(2), b=14.070(5), c=7.756(3) Å. The structure of AgTaS 3consists of two-dimensional 2∞[TaS -3] layers separated by Ag +cations. The layer is composed of Ta-centered bicapped trigonal prisms stacked on top of each other by sharing triangular faces. These chains are linked to form the infinite two-dimensional 2∞[TaS -3] slabs. These layers are held together through van der Waals interactions, and Ag +ions reside in the distorted octahedral sites between the layers. The temperature dependence of the electrical conductivity along the needle axis of AgTaS 3shows the typical behavior of an extrinsic semiconductor.

Tannic acid for remediation of historically arsenic-contaminated soils.

PubMed

Gusiatin, Zygmunt Mariusz; Klik, Barbara; Kulikowska, Dorota

2017-12-22

Soil washing effectively and permanently decreases soil pollution. Thus, it can be considered for the removal of the most toxic elements, for example arsenic (As). In this study, historically As-contaminated soils (2041-4294 mg/kg) were remediated with tannic acid (TA) as the washing agent. The scope of this study included optimization of the operational conditions of As removal, determination of As distribution in soil before and after double soil washing, and measurement of TA loss during washing. The optimum conditions for As removal were 4% TA, pH 4 and 24 h washing time. The average As removal after single and double washings was 38% and 63%, respectively. TA decreased As content in amorphous and poorly crystalline oxides by >90%. Although TA increased the amount of As in the easily mobilizable As fraction, the stability of As in washed soils increased, with reduced partition indexes of 0.52-0.66 after washing. The maximum capacity of the soils to adsorb TA (q max ) was 50.2-70.4 g C/kg. TA sorption was higher at alkaline than at acidic conditions. Only TA removes As from soils effectively if the proportion of As in amorphous and poorly crystalline oxides is high. Thus, it can be considered for remediation of historically contaminated soils.

Flavor of fresh blueberry juice and the comparison to amount of sugars, acids, anthocyanidins, and physicochemical measurements.

PubMed

Bett-Garber, Karen L; Lea, Jeanne M; Watson, Michael A; Grimm, Casey C; Lloyd, Steven W; Beaulieu, John C; Stein-Chisholm, Rebecca E; Andrzejewski, Brett P; Marshall, Donna A

2015-04-01

Six cultivars of southern highbush (SHB) and rabbiteye (RE) blueberry samples were harvested on 2 different dates. Each treatment combination was pressed 2 times for repeated measures. Fresh juice was characterized for 18 flavor/taste/feeling factor attributes by a descriptive flavor panel. Each sample was measured for sugars, acids, anthocyanidins, Folin-Ciocalteu, soluble solids (BRIX), titratable acidity (TA), and antioxidant capacity (ORACFL ). Flavors were correlated with the composition and physicochemical data. Blueberry flavor correlated with 3 parameters, and negatively correlated with 2. Strawberry correlated with oxalic acid and negatively correlated with sucrose and quinic acid. Sweet aroma correlated with oxalic and citric acid, but negatively correlated with sucrose, quinic, and total acids. Sweet taste correlated with 11 parameters, including the anthocyanidins; and negatively correlated with 3 parameters. Neither bitter nor astringent correlated with any of the antioxidant parameters, but both correlated with total acids. Sour correlated with total acids and TA, while negatively correlating with pH and BRIX:TA. Throat burn correlated with total acids and TA. Principal component analysis negatively related blueberry, sweet aroma, and sweet to sour, bitter, astringent, tongue tingle, and tongue numbness. The information in this component was related to pH, TA, and BRIX:TA ratio. Another principal component related the nonblueberry fruit flavors to BRIX. This PC, also divided the SHB berries from the RE. This work shows that the impact of juice composition on flavor is very complicated and that estimating flavor with physicochemical parameters is complicated by the composition of the juice. © 2015 Institute of Food Technologists®

Ectopic expression of a wheat WRKY transcription factor gene TaWRKY71-1 results in hyponastic leaves in Arabidopsis thaliana.

PubMed

Qin, Zhen; Lv, Hongjun; Zhu, Xinlei; Meng, Chen; Quan, Taiyong; Wang, Mengcheng; Xia, Guangmin

2013-01-01

Leaf type is an important trait that closely associates with crop yield. WRKY transcription factors exert diverse regulatory effects in plants, but their roles in the determination of leaf type have not been reported so far. In this work, we isolated a WRKY transcription factor gene TaWRKY71-1 from a wheat introgression line SR3, which has larger leaves, superior growth capacity and higher yield than its parent common wheat JN177. TaWRKY71-1 specifically expressed in leaves, and produced more mRNA in SR3 than in JN177. TaWRKY71-1 localized in the nucleus and had no transcriptional activation activity. TaWRKY71-1 overexpression in Arabidopsis resulted in hyponastic rosette leaves, and the hyponastic strength was closely correlative with the transcription level of the transgene. The spongy mesophyll cells at abaxial side of leaves were drastically compacted by TaWRKY71-1 overexpression. In TaWRKY71-1 overexpression Arabidopsis, the expression of IAMT1 that encodes a methyltransferase converting free indole-3-acetic acid (IAA) to methyl-IAA ester (MeIAA) to alter auxin homeostatic level was induced, and the induction level was dependent on the abundance of TaWRKY71-1 transcripts. Besides, several TCP genes that had found to be restricted by IAMT1 had lower expression levels as well. Our results suggest that TaWRKY71-1 causes hyponastic leaves through altering auxin homeostatic level by promoting the conversion of IAA to MeIAA.

The Wheat Mediator Subunit TaMED25 Interacts with the Transcription Factor TaEIL1 to Negatively Regulate Disease Resistance against Powdery Mildew1

PubMed Central

Zhang, Tianren; Jia, Jizeng; Sun, Jiaqiang

2016-01-01

Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici, is a major limitation for the production of bread wheat (Triticum aestivum). However, to date, the transcriptional regulation of bread wheat defense against powdery mildew remains largely unknown. Here, we report the function and molecular mechanism of the bread wheat Mediator subunit 25 (TaMED25) in regulating the bread wheat immune response signaling pathway. Three homoalleles of TaMED25 from bread wheat were identified and mapped to chromosomes 5A, 5B, and 5D, respectively. We show that knockdown of TaMED25 by barley stripe mosaic virus-induced gene silencing reduced bread wheat susceptibility to the powdery mildew fungus during the compatible plant-pathogen interaction. Moreover, our results indicate that MED25 may play a conserved role in regulating bread wheat and barley (Hordeum vulgare) susceptibility to powdery mildew. Similarly, bread wheat ETHYLENE INSENSITIVE3-LIKE1 (TaEIL1), an ortholog of Arabidopsis (Arabidopsis thaliana) ETHYLENE INSENSITIVE3, negatively regulates bread wheat resistance against powdery mildew. Using various approaches, we demonstrate that the conserved activator-interacting domain of TaMED25 interacts physically with the separate amino- and carboxyl-terminal regions of TaEIL1, contributing to the transcriptional activation activity of TaEIL1. Furthermore, we show that TaMED25 and TaEIL1 synergistically activate ETHYLENE RESPONSE FACTOR1 (TaERF1) transcription to modulate bread wheat basal disease resistance to B. graminis f. sp. tritici by repressing the expression of pathogenesis-related genes and deterring the accumulation of reactive oxygen species. Collectively, we identify the TaMED25-TaEIL1-TaERF1 signaling module as a negative regulator of bread wheat resistance to powdery mildew. PMID:26813794

Metabolism of nonesterified and esterified hydroxycinnamic acids in red wines by Brettanomyces bruxellensis.

PubMed

Schopp, Lauren M; Lee, Jungmin; Osborne, James P; Chescheir, Stuart C; Edwards, Charles G

2013-11-27

While Brettanomyces can metabolize nonesterified hydroxycinnamic acids found in grape musts/wines (caffeic, p-coumaric, and ferulic acids), it was not known whether this yeast could utilize the corresponding tartaric acid esters (caftaric, p-coutaric, and fertaric acids, respectively). Red wines from Washington and Oregon were inoculated with B. bruxellensis, while hydroxycinnamic acids were monitored by HPLC. Besides consuming p-coumaric and ferulic acids, strains I1a, B1b, and E1 isolated from Washington wines metabolized 40-50% of caffeic acid, a finding in contrast to strains obtained from California wines. Higher molar recoveries of 4-ethylphenol and 4-ethylguaiacol synthesized from p-coumaric and ferulic acids, respectively, were observed in Washington Cabernet Sauvignon and Syrah but not Merlot. This finding suggested that Brettanomyces either (a) utilized vinylphenols formed during processing of some wines or (b) metabolized other unidentified phenolic precursors. None of the strains of Brettanomyces studied metabolized caftaric or p-coutaric acids present in wines from Washington or Oregon.

Overexpression of wheat ferritin gene TaFER-5B enhances tolerance to heat stress and other abiotic stresses associated with the ROS scavenging.

PubMed

Zang, Xinshan; Geng, Xiaoli; Wang, Fei; Liu, Zhenshan; Zhang, Liyuan; Zhao, Yue; Tian, Xuejun; Ni, Zhongfu; Yao, Yingyin; Xin, Mingming; Hu, Zhaorong; Sun, Qixin; Peng, Huiru

2017-01-14

The yield of wheat (Triticum aestivum L.), an important crop, is adversely affected by heat stress in many regions of the world. However, the molecular mechanisms underlying thermotolerance are largely unknown. A novel ferritin gene, TaFER, was identified from our previous heat stress-responsive transcriptome analysis of a heat-tolerant wheat cultivar (TAM107). TaFER was mapped to chromosome 5B and named TaFER-5B. Expression pattern analysis revealed that TaFER-5B was induced by heat, polyethylene glycol (PEG), H 2 O 2 and Fe-ethylenediaminedi(o-hydroxyphenylacetic) acid (Fe-EDDHA). To confirm the function of TaFER-5B in wheat, TaFER-5B was transformed into the wheat cultivar Jimai5265 (JM5265), and the transgenic plants exhibited enhanced thermotolerance. To examine whether the function of ferritin from mono- and dico-species is conserved, TaFER-5B was transformed into Arabidopsis, and overexpression of TaFER-5B functionally complemented the heat stress-sensitive phenotype of a ferritin-lacking mutant of Arabidopsis. Moreover, TaFER-5B is essential for protecting cells against heat stress associated with protecting cells against ROS. In addition, TaFER-5B overexpression also enhanced drought, oxidative and excess iron stress tolerance associated with the ROS scavenging. Finally, TaFER-5B transgenic Arabidopsis and wheat plants exhibited improved leaf iron content. Our results suggest that TaFER-5B plays an important role in enhancing tolerance to heat stress and other abiotic stresses associated with the ROS scavenging.

Analysis of NiAlTa precipitates in beta-NiAl + 2 at. pct Ta alloy

NASA Technical Reports Server (NTRS)

Pathare, V.; Michal, G. M.; Vedula, K.; Nathal, M. V.

1987-01-01

Results are reported from experiments performed to identify the precipitates, and their orientation in the matrix, in a beta-NiAl alloy containing 2 at. pct. Ta after undergoing creep test at 1300 K. Test specimens formed by extruding hot powders were compressed at 1300 K for about 50 hr at a strain rate averaging 6/1 million per sec. The specimens were then thinned and examined under an electron microscope and by X-ray diffractometry. An intermetallic NiAlTa compound with a hexagonal Cl4 structure appeared as second phase precipitates in the samples, exhibiting plate-like shapes and a habit plane close to (012). The prism planes of the hexagonal NiAlTa precipitates paralleled the closest packed planes in the cubic beta-NiAl matrix.

Superconductivity in palladium-doped 2H-TaS2

NASA Astrophysics Data System (ADS)

Zhou, M. H.; Li, X. C.; Dong, C.

2018-06-01

A series of Pd x TaS2 (0.01 ≤ x ≤ 0.08) samples were prepared and characterized via scanning electron microscope, x-ray powder diffraction, resistivity, magnetization and specific heat measurements. The lattice parameter c associated with the interlayer distance increases monotonically with the Pd content while the parameter a remains essentially constant. The crystal structure of Pd0.08TaS2 has been determined and refined by Rietveld refinement. Pd0.08TaS2 is hexagonal (space group: P31c) with lattice parameters a = 3.3151(1) Å, c = 12.1497(9) Å. The superconducting transition temperature T c (0.8 K) of TaS2 can be dramatically enhanced by Pd doping, and the maximum T c of 4.2 K, about five times the T c of pure TaS2, is obtained in Pd0.04TaS2. We have determined the superconducting parameters of Pd0.04TaS2, and found that the enhancement of T c can be attributed to the increase of density of states at the Fermi level. The charge density wave (CDW) of TaS2 is gradually suppressed with Pd doping and disappears in Pd0.06TaS2. This suggests that there is a competitive interplay between superconductivity and CDW in this system.

Functional, structural and phylogenetic analysis of domains underlying the Al sensitivity of the aluminum-activated malate/anion transporter, TaALMT1.

PubMed

Ligaba, Ayalew; Dreyer, Ingo; Margaryan, Armine; Schneider, David J; Kochian, Leon; Piñeros, Miguel

2013-12-01

Triticum aestivum aluminum-activated malate transporter (TaALMT1) is the founding member of a unique gene family of anion transporters (ALMTs) that mediate the efflux of organic acids. A small sub-group of root-localized ALMTs, including TaALMT1, is physiologically associated with in planta aluminum (Al) resistance. TaALMT1 exhibits significant enhancement of transport activity in response to extracellular Al. In this study, we integrated structure-function analyses of structurally altered TaALMT1 proteins expressed in Xenopus oocytes with phylogenic analyses of the ALMT family. Our aim is to re-examine the role of protein domains in terms of their potential involvement in the Al-dependent enhancement (i.e. Al-responsiveness) of TaALMT1 transport activity, as well as the roles of all its 43 negatively charged amino acid residues. Our results indicate that the N-domain, which is predicted to form the conductive pathway, mediates ion transport even in the absence of the C-domain. However, segments in both domains are involved in Al(3+) sensing. We identified two regions, one at the N-terminus and a hydrophobic region at the C-terminus, that jointly contribute to the Al-response phenotype. Interestingly, the characteristic motif at the N-terminus appears to be specific for Al-responsive ALMTs. Our study highlights the need to include a comprehensive phylogenetic analysis when drawing inferences from structure-function analyses, as a significant proportion of the functional changes observed for TaALMT1 are most likely the result of alterations in the overall structural integrity of ALMT family proteins rather than modifications of specific sites involved in Al(3+) sensing. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Combined effects of organic acids and salt depending on type of acids and pathogens in laboratory media and acidified pickle.

PubMed

Bae, Y-M; Lee, S-Y

2015-08-01

In this study, the effectiveness of combining each of seven types of acids with 3% salt as a treatment against pathogens was investigated in laboratory media and acidified food. When 0.5% malic, 0.5% tartaric, 0.5% citric or 0.25% phosphoric acid was combined with 3% salt, there was a higher reduction in Gram-negative bacteria (Escherichia coli O157:H7 and Salmonella Typhimurium) compared to when using acid alone. However, when 0.5% acetic, 0.5% propionic or 0.25% lactic acid was combined with 3% salt, the salt provided protection against the acid treatment. However, the antagonistic effects of acetic, propionic and lactic acid seen with Gram-negative bacteria were not observed in Listeria monocytogenes. Antagonistic effects were similarly observed when E. coli O157:H7 was treated with acetic acid and salt in food. These results show that the addition of salt increases the resistance of Gram-negative bacteria to acid treatments when using acetic, propionic and lactic acid. This study shows that antagonistic effects were observed when Gram-negative bacteria were treated with organic acids of simple structure. It may provide useful information for understanding the acid resistance mechanism of Gram-negative bacteria and developing methods for preserving acidified food. © 2015 The Society for Applied Microbiology.

Determination of alpha-hydroxy acids in cosmetic products by high-performance liquid chromatography with a narrow-bore column.

PubMed

Nicoletti, I; Corradini, C; Cogliandro, E; Cavazza, A

1999-08-01

This paper reports the results of a study carried out to develop a simple, rapid and sensitive method for the separation, identification and quantitative measurement of alpha-hydroxy acids in commercial cosmetics using high-performance liquid chromatography (HPLC). This method is successfully applied to the simultaneous identification and quantitative determination of glycolic, lactic, malic, tartaric and citric acids employing a reversed phase narrow-bore column under isocratic condition and UV detection. The method is validated by determining the precision of replicate analyses and accuracy by analyzing samples with and without adding know amount of the alpha-hydroxy acids. The procedure is suitable for routine analyses of commercial cosmetics.

Phase relationships in the BaO-Ga2O3-Ta2O5 system and the structure of Ba6Ga21TaO40.

PubMed

Cao, Jiang; Yu, Xiaodi; Kuang, Xiaojun; Su, Qiang

2012-07-16

Phase relationships in the BaO-Ga(2)O(3)-Ta(2)O(5) ternary system at 1200 °C were determined. The A(6)B(10)O(30) tetragonal tungsten bronze (TTB) related solution in the BaO-Ta(2)O(5) subsystem dissolved up to ~11 mol % Ga(2)O(3), forming a ternary trapezoid-shaped TTB-related solid solution region defined by the BaTa(2)O(6), Ba(1.1)Ta(5)O(13.6), Ba(1.58)Ga(0.92)Ta(4.08)O(13.16), and Ba(6)GaTa(9)O(30) compositions in the BaO-Ga(2)O(3)-Ta(2)O(5) system. Two ternary phases Ba(6)Ga(21)TaO(40) and eight-layer twinned hexagonal perovskite solid solution Ba(8)Ga(4-x)Ta(4+0.6x)O(24) were confirmed in the BaO-Ga(2)O(3)-Ta(2)O(5) system. Ba(6)Ga(21)TaO(40) crystallized in a monoclinic cell of a = 15.9130(2) Å, b = 11.7309(1) Å, c = 5.13593(6) Å, β = 107.7893(9)°, and Z = 1 in space group C2/m. The structure of Ba(6)Ga(21)TaO(40) was solved by the charge flipping method, and it represents a three-dimensional (3D) mixed GaO(4) tetrahedral and GaO(6)/TaO(6) octahedral framework, forming mixed 1D 5/6-fold tunnels that accommodate the Ba cations along the c axis. The electrical property of Ba(6)Ga(21)TaO(40) was characterized by using ac impedance spectroscopy.

Electrospun polymer nanofibers reinforced by tannic acid/Fe+++ complexes

USDA-ARS?s Scientific Manuscript database

Nanofibers and fibrous mats of polyvinyl alcohol (PVA) loaded with tannic acid (TA) and ferric ion (Fe+++) complexes (TA-Fe+++) were synthesized by the electrospinning technique. The spinning solutions were characterized for surface tension, electrical conductivity, and viscosity. It was found that ...

Preliminary analysis of EUSO—TA data

NASA Astrophysics Data System (ADS)

Fenu, F.; Piotrowski, L. W.; Shin, H.; Jung, A.; Bacholle, S.; Bisconti, F.; Capel, F.; Eser, J.; Kawasaki, Y.; Kuznetsov, E.; Larsson, O.; Mackovjak, S.; Miyamoto, H.; Plebaniak, Z.; Prevot, G.; Putis, M.; Shinozaki, K.; Adams, J.; Bertaina, M.; Bobik, P.; Casolino, M.; Matthews, J. N.; Ricci, M.; Wiencke, L.; EUSO-TA Collaboration

2016-05-01

The EUSO-TA detector is a pathfinder for the JEM-EUSO project and is currently installed in Black Rock Mesa (Utah) on the site of the Telescope Array fluorescence detectors. Aim of this experiment is to validate the observation principle of JEM-EUSO on air showers measured from ground. The experiment gets data in coincidence with the TA triggers to increase the likelihood of cosmic ray detection. In this framework the collaboration is also testing the detector response with respect to several test events from lasers and LED flashers. Moreover, another aim of the project is the validation of the stability of the data acquisition chain in real sky condition and the optimization of the trigger scheme for the rejection of background. Data analysis is ongoing to identify cosmic ray events in coincidence with the TA detector. In this contribution we will show the response of the EUSO-TA detector to all the different typologies of events and we will show some preliminary results on the trigger optimization performed on such data.

Electrical and thermal properties of Cu-Ta films prepared by magnetron sputtering

NASA Astrophysics Data System (ADS)

Qin, Wen; Fu, Licai; Zhu, Jiajun; Yang, Wulin; Sang, Jianquan; Li, Deyi; Zhou, Lingping

2018-06-01

The microstructure, electrical resistivity and thermal conductivity of the sputtering deposited Cu-Ta films were investigated as a function of Ta content. The results showed that the amorphous phase formed between 20 at.% and 60 at.% Ta, and out of this range α-Cu(Ta) and β-Ta(Cu) solid solutions formed. Because the lattice distortion and β-Ta structure could significantly increase the probability of electron scattering, the electrical resistivity of the Cu-Ta films shows a 'N' type change with the increase of Ta content, and the inflection point appears at 50 at.% Ta and 60 at.% Ta respectively. As the thermal conductance is also dominated by electrons in metals films, an opposite variation tendency is found in the thermal conductivity of the Cu-Ta films. According to our knowledge, this is the first time to measure the thermal conductivity of Cu-Ta thin films.

The mutagenic assessment of an electronic-cigarette and reference cigarette smoke using the Ames assay in strains TA98 and TA100.

PubMed

Thorne, D; Crooks, I; Hollings, M; Seymour, A; Meredith, C; Gaca, M

2016-12-01

Salmonella typhimurium strains TA98 and TA100 were used to assess the mutagenic potential of the aerosol from a commercially available, rechargeable, closed system electronic-cigarette. Results obtained were compared to those for the mainstream smoke from a Kentucky reference (3R4F) cigarette. Two different test matrices were assessed. Aerosol generated from the e-cigarette was trapped on a Cambridge filter pad, eluted in DMSO and compared to cigarette smoke total particulate matter (TPM), which was generated in the same manner for mutagenicity assessment in the Salmonella assay. Fresh e-cigarette and cigarette smoke aerosols were generated on the Vitrocell ® VC 10 smoking robot and compared using a modified scaled-down 35mm air agar interface (AAI) methodology. E-cigarette aerosol collected matter (ACM) was found to be non-mutagenic in the 85mm plate incorporation Ames assay in strains TA98 and TA100 conducted in accordance with OECD 471, when tested up to 2400μg/plate. Freshly generated e-cigarette aerosol was also found to be negative in both strains after an AAI aerosol exposure, when tested up to a 1L/min dilution for up to 3h. Positive control responses were observed in both strains, using benzo[a]pyrene, 2-nitrofluorene, sodium azide and 2-aminoanthracene in TA98 and TA100 in the presence and absence of metabolic activation respectively. In contrast, cigarette smoke TPM and aerosol from 3R4F reference cigarettes were found to be mutagenic in both tester strains, under comparable test conditions to that of e-cigarette exposure. Limited information exists on the mutagenic activity of captured e-cigarette particulates and whole aerosol AAI approaches. With the lower toxicant burden of e-cigarette aerosols compared to cigarette smoke, it is clear that a more comprehensive Ames package of data should be generated when assessing e-cigarettes, consisting of the standard OECD-five, TA98, TA100, TA1535, TA1537 (or TA97) and E. coli (or TA102). In addition, TA104

The wheat homolog of putative nucleotide-binding site-leucine-rich repeat resistance gene TaRGA contributes to resistance against powdery mildew.

PubMed

Wang, Defu; Wang, Xiaobing; Mei, Yu; Dong, Hansong

2016-03-01

Powdery mildew, one of the most destructive wheat diseases worldwide, is caused by Blumeria graminis f. sp. tritici (Bgt), a fungal species with a consistently high mutation rate that makes individual resistance (R) genes ineffective. Therefore, effective resistance-related gene cloning is vital for breeding and studying the resistance mechanisms of the disease. In this study, a putative nucleotide-binding site-leucine-rich repeat (NBS-LRR) R gene (TaRGA) was cloned using a homology-based cloning strategy and analyzed for its effect on powdery mildew disease and wheat defense responses. Real-time reverse transcription-PCR (RT-PCR) analyses revealed that a Bgt isolate 15 and salicylic acid stimulation significantly induced TaRGA in the resistant variety. Furthermore, the silencing of TaRGA in powdery mildew-resistant plants increased susceptibility to Bgt15 and prompted conidia propagation at the infection site. However, the expression of TaRGA in leaf segments after single-cell transient expression assay highly increased the defense responses to Bgt15 by enhancing callose deposition and phenolic autofluorogen accumulation at the pathogen invading sites. Meanwhile, the expression of pathogenesis-related genes decreased in the TaRGA-silenced plants and increased in the TaRGA-transient-overexpressing leaf segments. These results implied that the TaRGA gene positively regulates the defense response to powdery mildew disease in wheat.

TaOx-based resistive switching memories: prospective and challenges

PubMed Central

2013-01-01

Resistive switching memories (RRAMs) are attractive for replacement of conventional flash in the future. Although different switching materials have been reported; however, low-current operated devices (<100 μA) are necessary for productive RRAM applications. Therefore, TaOx is one of the prospective switching materials because of two stable phases of TaO2 and Ta2O5, which can also control the stable low- and high-resistance states. Long program/erase endurance and data retention at high temperature under low-current operation are also reported in published literature. So far, bilayered TaOx with inert electrodes (Pt and/or Ir) or single layer TaOx with semi-reactive electrodes (W and Ti/W or Ta/Pt) is proposed for real RRAM applications. It is found that the memory characteristics at current compliance (CC) of 80 μA is acceptable for real application; however, data are becoming worst at CC of 10 μA. Therefore, it is very challenging to reduce the operation current (few microampere) of the RRAM devices. This study investigates the switching mode, mechanism, and performance of low-current operated TaOx-based devices as compared to other RRAM devices. This topical review will not only help for application of TaOx-based nanoscale RRAM devices but also encourage researcher to overcome the challenges in the future production. PMID:24107610

Analysis of organic acids and phenols of interest in the wine industry using Langmuir-Blodgett films based on functionalized nanoparticles.

PubMed

Medina-Plaza, C; García-Cabezón, C; García-Hernández, C; Bramorski, C; Blanco-Val, Y; Martín-Pedrosa, F; Kawai, T; de Saja, J A; Rodríguez-Méndez, M L

2015-01-01

A chemically modified electrode consisting of Langmuir-Blodgett (LB) films of n-dodecanethiol functionalized gold nanoparticles (SDODAuNP-LB), was investigated as a voltammetric sensor of organic and phenolic acids of interest in the wine industry. The nanostructured films demonstrated interfacial properties being able to detect the main organic acids present in grapes and wines (tartaric, malic, lactic and citric). Compared to a bare ITO electrode, the modified electrodes exhibited a shift of the reduction potential in the less positive direction and a marked enhancement in the current response. Moreover, the increased electrocatalytic properties made it possible to distinguish between the different dissociable protons of polyprotic acids. The SDODAuNP-LB sensor was also able to provide enhanced responses toward aqueous solutions of phenolic acids commonly found in wines (caffeic and gallic acids). The presence of nanoparticles increased drastically the sensitivity toward organic acids and phenolic compounds. Limits of detection as low as 10(-6) mol L(-1) were achieved. Efficient catalytic activity was also observed in mixtures of phenolic acid/tartaric in the range of pHs typically found in wines. In such mixtures, the electrode was able to provide simultaneous information about the acid and the phenol concentrations with a complete absence of interferences. The excellent sensing properties shown by these sensors could be attributed to the electrocatalytic properties of the nanoparticles combined with the high surface to volume ratio and homogeneity provided by the LB technique used for the immobilization. Moreover, the LB technique also provided an accurate method to immobilize the gold nanoparticles giving rise to stable and reproducible sensors showing repeatability lower than 2% and reproducibility lower than 4% for all the compounds analyzed. Copyright © 2014. Published by Elsevier B.V.

Effect of Ta concentration on the refractive index of TiO{sub 2}:Ta studied by spectroscopic ellipsometry

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

Nurfani, Eka, E-mail: ekanurfani@gmail.com; Kurniawan, Robi; Muhammady, Shibghatullah

2016-04-19

We have investigated optical properties of Ta-doped TiO{sub 2} thin film on LaAlO{sub 3} (LAO) substrate using Spectroscopic Ellipsometry (SE) at room temperature. Amplitude ratio Ψ and phase difference L1 between p- and s- polarized light waves are obtained by multiple incident angles measurement (60°, 70°, and 80°) at energy range of 0.5 – 6.5 eV. In order to obtain optical properties for every Ta concentrations (0.01, 0.4, and 5 at. %), multilayer modelling was performed simultaneously by using Drude-Lorentz model. Refractive index and optical dispersion parameters were determined by Wemple-DiDomenico relation. In general, refractive index at zero photon energymore » n(0) increases by increasing Ta concentration. Furthermore, optical band gap shows a significant increasing due to presence of Ta dopant. In addition, other optical constants are discussed as well.« less

Exploring the trans-acting short interfering RNAs (ta-siRNAs) technology for virus control in plants

USDA-ARS?s Scientific Manuscript database

Small ribonucleic acid (RNAs) (~20-24nt) processed from double-stranded RNA in plants can trigger degradation of the target mRNAs in cytoplasm or de novo DNA methylation in nucleus leading to gene silencing. Trans-acting short-interfering RNAs (ta-siRNAs) have been shown to enhance the target mRNA d...

Effects of thickness and annealing condition on magnetic properties and thermal stabilities of Ta/Nd/NdFeB/Nd/Ta sandwiched films

NASA Astrophysics Data System (ADS)

Liu, Wen-Feng; Zhang, Min-Gang; Zhang, Ke-Wei; Zhang, Hai-Jie; Xu, Xiao-Hong; Chai, Yue-Sheng

2016-11-01

Ta/Nd/NdFeB/Nd/Ta sandwiched films are deposited by magnetron sputtering on Si (100) substrates, and subsequently annealed in vacuum at different temperatures for different time. It is found that both the thickness of NdFeB and Nd layer and the annealing condition can affect the magnetic properties of Ta/Nd/NdFeB/Nd/Ta films. Interestingly, the thickness and annealing temperature show the relevant behaviors that can affect the magnetic properties of the film. The high coercivity of 24.1 kOe (1 Oe = 79.5775 A/m) and remanence ratio (remanent magnetization/saturation magnetization) of 0.94 can be obtained in a Ta/Nd(250 nm)/NdFeB(600 nm)/Nd(250 nm)/Ta film annealed for 3 min at 1023 K. In addition, the thermal stability of the film is also linked to the thickness of NdFeB and Nd layer and the annealing temperature as well. The excellent thermal stability can be achieved in a Ta/Nd(250 nm)/NdFeB(600 nm)/Nd(250 nm)/Ta film annealed at 1023 K. Program supported by the National Natural Science Foundation of China (Grant No. 51305290), the Higher Education Technical Innovation Project of Shanxi Province, China (Grant No. 2013133), the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals of Shanxi Province, China (Grant No. 2015003), and the Program for the Key Team of Scientific and Technological Innovation of Shanxi Province, China (Grant No. 2013131009).

Crosslinked self-assemblies of lipoid acid-substituted low molecular weight (1800 Da) polyethylenimine as reductive-sensitive non-viral gene vectors

NASA Astrophysics Data System (ADS)

Chen, Xiaojiao; Yuan, Zhefan; Yi, Xiaoqing; Zhuo, Renxi; Li, Feng

2012-10-01

In this study, amphiphilic polyethylenimine-graft-thioctic acid (PEI-TA) and polyethylenimine-graft-lauric acid (PEI-LA) were synthesized. Both PEI-TA and PEI-LA could self-assemble into micelles. Due to the existence of disulfide-linked rings at the end of hydrophobic moieties, PEI-TA could form stable micelles with disulfide crosslinked cores (PEI-TA-SS). In comparison with the PEI-LA micelle, PEI-TA-SS possessed higher DNA binding ability according to the gel retardation assay and heparin replacement assay. In vitro transfection experiments indicated that PEI-TA-SS showed comparably high transfection efficiency as compared to 25 kDa PEI. More interestingly, the luciferase expression of PEI-TA-SS was superior to that of PEI-LA at low N/P ratio, which might be ascribed to the stronger binding capacity of PEI-TA-SS facilitating the entering of PEI-TA-SS/pDNA complexes into cells.

Effects of low molecular weight organic acids on (137)Cs release from contaminated soils.

PubMed

Chiang, Po Neng; Wang, Ming Kuang; Huang, Pan Ming; Wang, Jeng Jong

2011-06-01

Radio pollutant removal is one of several priority restoration strategies for the environment. This study assessed the effect of low molecular weight organic acid on the lability and mechanisms for release of (137)Cs from contaminated soils. The amount of (137)Cs radioactivity released from contaminated soils reacting with 0.02 M low molecular weight organic acids (LMWOAs) specifically acetic, succinic, oxalic, tartaric, and citric acid over 48 h were 265, 370, 760, 850, and 1002 Bq kg(-1), respectively. The kinetic results indicate that (137)Cs exhibits a two-step parabolic diffusion equation and a good linear relationship, indicating that the parabolic diffusion equation describes the data quite well, as shown by low p and high r(2) values. The fast stage, which was found to occur within a short period of time (0.083-3 h), corresponds to the interaction of LMWOAs with the surface of clay minerals; meanwhile, during the slow stage, which occurs over a much longer time period (3-24 h), desorption primarily is attributed to inter-particle or intra-particle diffusion. After a fifth renewal of the LMWOAs, the total levels of (137)Cs radioactivity released by acetic, succinic, oxalic, tartaric, and citric acid were equivalent to 390, 520, 3949, 2061, and 4422 Bq kg(-1) soil, respectively. H(+) can protonate the hydroxyl groups and oxygen atoms at the broken edges or surfaces of the minerals, thereby weakening Fe-O and Al-O bonds. After protonation of H(+), organic ligands can attack the OH and OH(2) groups in the minerals easily, to form complexes with surface structure cations, such as Al and Fe. The amounts of (137)Cs released from contaminated soil treated with LMWOAs were substantially increased, indicating that the LMWOAs excreted by the roots of plants play a critical role in (137)Cs release. Copyright © 2011 Elsevier Ltd. All rights reserved.

Functional analysis of a pathogenesis-related thaumatin-like protein gene TaLr35PR5 from wheat induced by leaf rust fungus.

PubMed

Zhang, Jiarui; Wang, Fei; Liang, Fang; Zhang, Yanjun; Ma, Lisong; Wang, Haiyan; Liu, Daqun

2018-05-04

Plants have evolved multifaceted defence mechanisms to resist pathogen infection. Production of the pathogenesis-related (PR) proteins in response to pathogen attack has been implicated in plant disease resistance specialized in systemic-acquired resistance (SAR). Our earlier studies have reported that a full length TaLr35PR5 gene, encoding a protein exhibiting amino acid and structural similarity to a sweet protein thaumatin, was isolated from wheat near-isogenic line TcLr35. The present study aims to understand the function of TaLr35PR5 gene in Lr35-mediated adult resistance to Puccinia triticina. We determined that the TaLr35PR5 protein contained a functional secretion peptide by utilizing the yeast signal sequence trap system. Using a heterologous expression assay on onion epidermal cells we found that TaLr35PR5 protein was secreted into the apoplast of onion cell. Expression of TaLr35PR5 was significantly reduced in BSMV-induced gene silenced wheat plants, and pathology test on these silenced plants revealed that Lr35-mediated resistance phenotype was obviously altered, indicating that Lr35-mediated resistance was compromised. All these findings strongly suggest that TaLr35PR5 is involved in Lr35-mediated adult wheat defense in response to leaf rust attack.

Myxobacterium-Produced Antibiotic TA (Myxovirescin) Inhibits Type II Signal Peptidase

PubMed Central

Xiao, Yao; Gerth, Klaus; Müller, Rolf

2012-01-01

Antibiotic TA is a macrocyclic secondary metabolite produced by myxobacteria that has broad-spectrum bactericidal activity. The structure of TA is unique, and its molecular target is unknown. Here, we sought to elucidate TA's mode of action (MOA) through two parallel genetic approaches. First, chromosomal Escherichia coli TA-resistant mutants were isolated. One mutant that showed specific resistance toward TA was mapped and resulted from an IS4 insertion in the lpp gene, which encodes an abundant outer membrane (Braun's) lipoprotein. In a second approach, the comprehensive E. coli ASKA plasmid library was screened for overexpressing clones that conferred TAr. This effort resulted in the isolation of the lspA gene, which encodes the type II signal peptidase that cleaves signal sequences from prolipoproteins. In whole cells, TA was shown to inhibit Lpp prolipoprotein processing, similar to the known LspA inhibitor globomycin. Based on genetic evidence and prior globomycin studies, a block in Lpp expression or prevention of Lpp covalent cell wall attachment confers TAr by alleviating a toxic buildup of mislocalized pro-Lpp. Taken together, these data argue that LspA is the molecular target of TA. Strikingly, the giant ta biosynthetic gene cluster encodes two lspA paralogs that we hypothesize play a role in producer strain resistance. PMID:22232277

Structure of metal-oxide Ti-Ta-(Ti,Ta)xOy coatings during spark alloying and induction-thermal oxidation

NASA Astrophysics Data System (ADS)

Koshuro, V.; Fomin, A.; Fomina, M.; Rodionov, I.; Brzhozovskii, B.; Martynov, V.; Zakharevich, A.; Aman, A.; Oseev, A.; Majcherek, S.; Hirsch, S.

2016-08-01

The study focuses on combined spark alloying of titanium and titanium alloy surface and porous matrix structure oxidation. The metal-oxide coatings morphology is the result of melt drop transfer, heat treatment, and oxidation. The study establishes the influence of technological regimes of alloying and oxidation on morphological heterogeneity of metal- oxide system Ti-Ta-(Ti,Ta)xOy.

Effects of grinding and humidification on the transformation of conglomerate to racemic compound in optically active drugs.

PubMed

Piyarom, S; Yonemochi, E; Oguchi, T; Yamamoto, K

1997-04-01

The effects of grinding and humidification on the transformation of conglomerate to racemic compound have been investigated by X-ray powder diffraction (XPD), differential scanning calorimetry (DSC) and infrared (IR) spectroscopy for leucine, norleucine, valine, serine, tartaric acid and malic acid. Racemic physical mixtures were prepared by physical mixing of equimolar quantities of D and I. crystals using a mortar and pestle. Ground mixtures were obtained by grinding the physical mixtures with a vibrational mill. Humidification was performed by storing the physical mixtures and the ground mixtures in a desiccator containing saturated aqueous salt solutions at 40 degrees C. When physical mixtures of malic acid, tartaric acid and serine were ground, the XPD peaks of the racemic compounds were observed. The XPD patterns of humidified physical mixtures of these compounds also showed the formation of the racemic compounds. This indicated that grinding or humidification of malic acid, tartaric acid and serine induced the transformation of conglomerate to racemic compound crystals. When, on the other hand, the physical mixtures of valine, leucine and norleucine were ground, peaks of racemic compounds were not detected in the XPD pattern. After humidification of the ground mixtures of valine, leucine and norleucine, however, the XPD peaks of racemic compounds were observed. DSC and IR studies revealed consistent results. We concluded that grinding or humidification of malic acid, tartaric acid and serine could induce the transformation of a conglomerate to racemic compound. In contrast, humidifying after grinding was needed to bring about the transformation in leucine, norleucine and valine.

Characterisation of the nicotianamine aminotransferase and deoxymugineic acid synthase genes essential to Strategy II iron uptake in bread wheat (Triticum aestivum L.)

PubMed Central

Johnson, Alexander A. T.

2017-01-01

Iron (Fe) uptake in graminaceous plant species occurs via the release and uptake of Fe-chelating compounds known as mugineic acid family phytosiderophores (MAs). In the MAs biosynthetic pathway, nicotianamine aminotransferase (NAAT) and deoxymugineic acid synthase (DMAS) enzymes catalyse the formation of 2’-deoxymugineic acid (DMA) from nicotianamine (NA). Here we describe the identification and characterisation of six TaNAAT and three TaDMAS1 genes in bread wheat (Triticum aestivum L.). The coding sequences of all six TaNAAT homeologs consist of seven exons with ≥88.0% nucleotide sequence identity and most sequence variation present in the first exon. The coding sequences of the three TaDMAS1 homeologs consist of three exons with ≥97.8% nucleotide sequence identity. Phylogenetic analysis revealed that the TaNAAT and TaDMAS1 proteins are most closely related to the HvNAAT and HvDMAS1 proteins of barley and that there are two distinct groups of TaNAAT proteins—TaNAAT1 and TaNAAT2 –that correspond to the HvNAATA and HvNAATB proteins, respectively. Quantitative reverse transcription-PCR analysis revealed that the TaNAAT2 genes are expressed at highest levels in anther tissues whilst the TaNAAT1 and TaDMAS1 genes are expressed at highest levels in root tissues of bread wheat. Furthermore, the TaNAAT1, TaNAAT2 and TaDMAS1 genes were differentially regulated by plant Fe status and their expression was significantly upregulated in root tissues from day five onwards during a seven-day Fe deficiency treatment. The identification and characterization of the TaNAAT1, TaNAAT2 and TaDMAS1 genes provides a valuable genetic resource for improving bread wheat growth on Fe deficient soils and enhancing grain Fe nutrition. PMID:28475636

Enhanced pulmonary absorption of poorly soluble itraconazole by micronized cocrystal dry powder formulations.

PubMed

Karashima, Masatoshi; Sano, Noriyasu; Yamamoto, Syunsuke; Arai, Yuta; Yamamoto, Katsuhiko; Amano, Nobuyuki; Ikeda, Yukihiro

2017-06-01

Micronized cocrystal powders and amorphous spray-dried formulations were prepared and evaluated in vivo and in vitro as pulmonary absorption enhancement formulations of poorly soluble itraconazole (ITZ). ITZ cocrystals with succinic acid (SA) or l-tartaric acid (TA) with a particle size diameter of <2μm were successfully micronized using the jet-milling system. The cocrystal crystalline morphologies observed using scanning electron microscopy (SEM) suggested particle shapes that differed from those of the crystalline or spray-dried amorphous ITZ. The micronized ITZ cocrystal powders showed better intrinsic dissolution rate (IDR) and pulmonary absorption profile in rats than that of the amorphous spray-dried formulation and crystalline ITZ with comparable particle sizes. Specifically, in rat pharmacokinetic studies following pulmonary administration, micronized ITZ-SA and ITZ-TA cocrystals showed area under the curve from 0 to 8h (AUC 0-8h ) values approximately 24- and 19-fold higher than those of the crystalline ITZ and 2.0- and 1.6-fold higher than the spray-dried ITZ amorphous values, respectively. The amorphous formulation appeared physically instable during the studies due to rapid crystallization of ITZ, which was its disadvantage compared to the crystalline formulations. Therefore, this study demonstrated that micronized cocrystals are promising formulations for enhancing the pulmonary absorption of poorly soluble compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

Improvement in Wood Bonding Strength of Poly (Vinyl Acetate-Butyl Acrylate) Emulsion by Controlling the Amount of Redox Initiator

PubMed Central

Zhang, Yun; Pang, Bo; Yang, Sen; Fang, Wei; Yang, Sheng; Yuan, Tong-Qi; Sun, Run-Cang

2018-01-01

Polyvinyl acetate emulsion adhesive has been widely used due to its good bonding performance and environmentally friendly properties. Indeed, the bonding performance can be further improved by copolymerizing with other monomers. In this study, the effect of the adjunction of redox initiator (hydrogen peroxide–tartaric acid, H2O2–TA) on the properties of the poly (vinyl acetate-butyl acrylate) (P (VAc–BA)) emulsion adhesive was investigated. With increasing dosage, the reaction became more complete and the obtained film was more compact, as identified via SEM. The core-shell structure of the emulsion particles was confirmed via TEM. Results indicate that while the initiator content increased from 0.5 to 1.0%, a clearer core-shell structure was obtained and the bonding strength of the plywood improved from 2.34 to 2.97 MPa. With the further incorporation of H2O2–TA (i.e., 1.5%), the bonding performance deteriorated. The optimum wood bonding strength (2.97 MPa) of the prepared P (VAc-BA) emulsion adhesive was even better than that (2.55 MPa) of a commercial PVAc emulsion adhesive, suggesting its potential application for the wood industry. PMID:29316725

77 FR 47671 - TA-W-81,520, T-Mobile USA, Inc., Call Center, Allentown, PA; TA-W-81,520G, T-Mobile USA, Inc...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-09

... DEPARTMENT OF LABOR Employment and Training Administration TA-W-81,520, T-Mobile USA, Inc., Call Center, Allentown, PA; TA- W-81,520G, T-Mobile USA, Inc., Headquarters Office, Bellevue, WA; Amended... of T-Mobile USA, Inc., Call Center, Allentown, Pennsylvania (TA-W-81,520), Fort Lauderdale, Florida...

21 CFR 582.1099 - Tartaric acid.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582... recognized as safe when used in accordance with good manufacturing or feeding practice. ...

Showing Enantiomorphous Crystals of Tartaric Acid

ERIC Educational Resources Information Center

Andrade-Gamboa, Julio

2007-01-01

Most of the articles and textbooks that show drawings of enantiomorphous crystals use an inadequate view to appreciate the fact that they are non-superimposable mirror images of one another. If a graphical presentation of crystal chirality is not evident, the main attribute of crystal enantiomorphism can not be recognized by students. The classic…

21 CFR 582.1099 - Tartaric acid.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582... recognized as safe when used in accordance with good manufacturing or feeding practice. ...

21 CFR 582.1099 - Tartaric acid.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582... recognized as safe when used in accordance with good manufacturing or feeding practice. ...

21 CFR 582.1099 - Tartaric acid.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582... recognized as safe when used in accordance with good manufacturing or feeding practice. ...

21 CFR 582.1099 - Tartaric acid.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582... recognized as safe when used in accordance with good manufacturing or feeding practice. ...

Influence of Ta doping in resistive switching behavior of TiO2

NASA Astrophysics Data System (ADS)

Barman, Arabinda; Saini, Chetan P.; Deshmukh, Sujit; Dhar, Sankar; Kanjilal, Aloke

An approach has been made to understand the resistive switching behavior in Ta-doped TiO2 films on Pt substrates. Prior to thin film deposition, Ta-doped TiO2 powder has been synthesized chemically using Ta and Ti precursor solutions. However, the Ta doping has seriously been affected by increasing Ta concentration above 1 at% due to the segregation of Ta2O5 phase. The Ta-doped TiO2 targets have been prepared for pulsed laser deposition of the films on Pt substrates using an excitation wavelength of 248 nm. The structural and chemical properties of the Ta-doped TiO2 films have been investigated in details with the help of XRD, SIMS, XAS and XPS. The stoichiometry of the Ta-doped TiO2 films with increasing depth has been verified initially by SIMS. The electrical study of the corresponding device structures further suggests that the optimized resistive switching effect can be accomplished up to a threshold Ta-doping of 1 at%. Nevertheless, a highly conducting behavior has been shown when the TiO2 films are doped with 2 at% Ta. These results will be discussed in details in the light of defect induced resistive switching phenomenon.

Lack of interaction between thioctic acid, glibenclamide and acarbose

PubMed Central

Gleiter, C H; Schreeb, K H; Freudenthaler, S; Thomas, M; Elze, M; Fieger-Büschges, H; Potthast, H; Schneider, E; Schug, B S; Blume, H H; Hermann, R

1999-01-01

Aims Thioctic acid (TA), glibenclamide and acarbose are widely used to either alone or concomitantly treat patients suffering from noninsulin-dependent diabetes (NIDDM). This study systematically investigated drug–drug interactions between TA and glibenclamide and TA and acarbose. Methods Fourteen male and 10 female healthy volunteers participated a randomized, open three period cross over trial (treatments A–C) followed by a fourth period (treatment D). A baseline profile for plasma insulin and glucose concentrations, variables which served as pharmacodynamic measures, was assessed before entering the trial. Treatments were A=600 mg TA orally, B=3.5 mg glibenclamide orally, C=600 mg TA+3.5 mg glibenclamide, D=600 mg TA+50 mg acarbose. Time courses of R(+)-TA and S(−)-TA as well as glibenclamide concentrations were measured with specific analytical methods. Results There was no clinically relevant change of TA enantiomer pharmacokinetics by glibenclamide or acarbose. Also, glibenclamide pharmacokinetics were not altered by TA to a clinically meaningful extent. Plasma insulin and glucose concentrations did not indicate an interaction between TA and glibenclamide or TA and acarbose. Glibenclamide had the expected effect on insulin and glucose levels independent of comedication. There were only minor and short lasting adverse events with the majority being (expected) hypoglycaemic symptoms occurring during the treatments with glibenclamide. Conclusions Coadministration of single doses of TA and glibenclamide or TA and acarbose does not appear to cause drug–drug interactions. PMID:10594485

Redetermination of Na(3)TaF(8).

PubMed

Langer, Vratislav; Smrcok, Lubomír; Boca, Miroslav

2010-09-01

The crystal structure of trisodium octafluoridotantalate, Na(3)TaF(8), has been redetermined using diffractometer data collected at 153 K, resulting in more accurate bond distances and angles than obtained from a previous structure determination based on film data. The structure is built from layers running along [101], which are formed by distorted [TaF(8)] antiprisms and [NaF(6)] rectangular bipyramids sharing edges and corners. The individual layers are separated by eight-coordinated Na ions. Two atoms in the asymmetric unit are in special positions: the Ta atom is on a twofold axis in Wyckoff position 4e and one of the Na ions lies on an inversion centre in Wyckoff site 4d.

Removal of Pb and Zn from contaminated soil by different washing methods: the influence of reagents and ultrasound.

PubMed

Wang, Jiaming; Jiang, Jianguo; Li, Dean; Li, Tianran; Li, Kaimin; Tian, Sicong

2015-12-01

Pb and Zn contamination in agricultural soils has become an important issue for human health and the environment. Washing is an effective method for remediating polluted soil. Here, we compare several washing materials and methods in the treatment of Pb- and Zn-polluted farmland soil. We examined four washing reagents, hydrochloric acid, citric acid, Na2EDTA, and tartaric acid, all of which independently removed Zn at rates >65 %. Combining washing reagents markedly enhanced heavy metal removal, by using Na2EDTA and either tartaric acid or lactate in sequence: Pb and Zn removal rates improved to 84.1 and 82.1 % for Na2EDTA-tartaric acid; and to 88.3 and 89.9 % for Na2EDTA-lactate, respectively. Additionally, combining ultrasound with conventional washing methods markedly improved washing efficiency, by shortening washing duration by 96 %. We achieved similar removal rates using ultrasound for 10 min, compared with traditional mechanical vibration alone for 4 h. We concluded that treating Pb- and Zn-contaminated soil with appropriate washing reagents under optimal conditions can greatly enhance the remediation of polluted farmland soils.

TaLHY, a 1R-MYB Transcription Factor, Plays an Important Role in Disease Resistance against Stripe Rust Fungus and Ear Heading in Wheat

PubMed Central

Zhang, Zijin; Chen, Jieming; Su, Yongying; Liu, Hanmei; Chen, Yanger; Luo, Peigao; Du, Xiaogang; Wang, Dan; Zhang, Huaiyu

2015-01-01

LHY (late elongated hypocotyl) is an important gene that regulates and controls biological rhythms in plants. Additionally, LHY is highly expressed in the SSH (suppression subtractive hybridization) cDNA library-induced stripe rust pathogen (CYR32) in our previous research. To identify the function of the LHY gene in disease resistance against stripe rust, we used RACE-PCR technology to clone TaLHY in the wheat variety Chuannong19. The cDNA of TaLHY is 3085 bp long with an open reading frame of 1947 bp. TaLHY is speculated to encode a 70.3 kDa protein of 648 amino acids , which has one typical plant MYB-DNA binding domain; additionally, phylogenetic tree shows that TaLHY has the highest homology with LHY of Brachypodium distachyon(BdLHY-like). Quantitative fluorescence PCR indicates that TaLHY has higher expression in the leaf, ear and stem of wheat but lower expression in the root. Infestation of CYR32 can result in up-regulated expression of TaLHY, peaking at 72 h. Using VIGS (virus-induced gene silencing) technology to disease-resistant wheat in the fourth leaf stage, plants with silenced TaLHY cannot complete their heading stage. Through the compatible interaction with the stripe rust physiological race CYR32, Chuannong 19 loses its immune capability toward the stripe rust pathogen, indicating that TaLHY may regulate and participate in the heading of wheat, as well as the defense responses against stripe rust infection. PMID:26010918

Synthesis and mutagenicity of a ring-A-aromatized bile acid, 3-hydroxy-19-nor-1,3,5(10)-cholatrien-24-oic acid.

PubMed

Namba, T; Hirota, T; Hayakawa, S

1988-06-01

It has been presumed that ring-A-aromatized bile acids are produced from biliary bile acids by intestinal flora and the acids thus formed participate in the large bowel carcinogenesis. One of these acids is probably 3-hydroxy-19-nor-1,3,5(10)-cholatrien-24-oic acid, judged from the literatures. Consequently, this acid was synthesized from previously prepared 3-methoxy-19-nor-1,3,5(10)-cholatrien-24-ol. The phenolic ether was successively oxidized with pyridinium chlorochromate and wet silver oxide to give 3-methoxy-19-nor-1,3,5(10)-cholatrien-24-oic acid in high yield, which, after successive treatments with methanol containing a catalytic amount of p-toluenesulfonic acid, a combination of aluminum chloride and ethanethiol, and alkali, gave the desired compound in satisfactory yield. The compound was not mutagenic in Salmonella tester strains TA 98 and TA 100, but it increased the mutagenicity of 2-aminoanthracene when both were applied to plates together. When compared with cholic, deoxycholic, and lithocholic acids, the investigated compound exhibited about two to threefold increase of mutagenicity in the latter assay.

Improved interface properties of Ge metal-oxide-semiconductor capacitor with TaTiO gate dielectric by using in situ TaON passivation interlayer

NASA Astrophysics Data System (ADS)

Ji, F.; Xu, J. P.; Liu, J. G.; Li, C. X.; Lai, P. T.

2011-05-01

TaON is in situ formed as a passivating interlayer in Ge metal-oxide-semiconductor (MOS) capacitors with high-k TaTiO gate dielectric fabricated simply by alternate sputtering of Ta and Ti. Also, postdeposition annealing is performed in wet N2 to suppress the growth of unstable GeOx at the Ge surface. As a result, excellent electrical properties of the Ge MOS devices are demonstrated, such as high equivalent dielectric constant (22.1), low interface-state density (7.3×1011 cm-2 eV), small gate leakage current (8.6×10-4 A cm-2 at Vg-Vfb=1 V), and high device reliability. Transmission electron microscopy and x-ray photoelectron spectroscopy support that all these should be attributed to the fact that the nitrogen barrier in the TaON interlayer can effectively block the interdiffusions of Ge and Ta, and the wet-N2 anneal can significantly suppress the growth of unstable low-k GeOx.

Effect of new synthetic PEGylated ferulic acids in comparison with ferulic acid and commercial surfactants on the properties of wheat flour dough and bread.

PubMed

Nicks, François; Richel, Aurore; Dubrowski, Thomas; Wathelet, Bernard; Wathelet, Jean-Paul; Blecker, Christophe; Paquot, Michel

2013-08-15

Ferulic acid esterified with poly(ethylene glycol) with three different average molecular weights (200, 400 and 1000 g mol(-1)) was studied in bread-making. The effects of these antioxidants on the properties of wheat flour dough and bread were analysed and compared with those obtained with ferulic acid and two commercial surfactants, the diacetyl tartaric acid ester of mono- and diglycerides and sodium stearoyl lactylate. Farinographic and alveographic methods as well as weight, volume and bread firmness measurements were used for this purpose. Similar to ferulic acid, when the PEGylated derivatives were implemented in the dough (5000 ppm), it accelerated the breakdown of the dough and decreased its rheological properties. However, the important diminution of loaf volume, observed when dough supplemented with ferulic acid was baked, was avoided. That decrease in volume was related to the inhibition of the yeast (Saccharomyces cerevisae) by the unesterified ferulic acid. Moreover, two of the PEGylated ferulic acids even contributed to an increase of loaf volumes (5-6%) and demonstrated crumb softener properties. The addition of ferulic acid to wheat flour dough caused the inhibition of the yeast, which resulted in decreased bread volume. That effect could be avoid by the esterification of ferulic acid with poly(ethylene glycol). © 2013 Society of Chemical Industry.

Argon Shrouded Plasma Spraying of Tantalum over Titanium for Corrosion Protection in Fluorinated Nitric Acid Media

NASA Astrophysics Data System (ADS)

Vetrivendan, E.; Jayaraj, J.; Ningshen, S.; Mallika, C.; Kamachi Mudali, U.

2018-02-01

Argon shrouded plasma spraying (ASPS) was used to deposit a Ta coating on commercially pure Ti (CP-Ti) under inert argon, for dissolver vessel application in the aqueous spent fuels reprocessing plant with high plutonium content. Oxidation during plasma spraying was minimized by shrouding argon system. Porosity and oxide content were controlled by optimizing the spraying parameters, to obtain a uniform and dense Ta coating. The Ta particle temperature and velocity were optimized by judiciously controlling the spray parameters, using a spray diagnostic charge-coupled device camera. The corrosion resistance of the Ta coatings developed by ASPS was investigated by electrochemical studies in 11.5 M HNO3 and 11.5 M HNO3 + 0.05 M NaF. Similarly, the durability of the ASPS Ta coating/substrate was evaluated as per ASTM A262 Practice-C test in boiling nitric acid and fluorinated nitric acid for 240 h. The ASPS Ta coating exhibited higher corrosion resistance than the CP-Ti substrate, as evident from electrochemical studies, and low corrosion rate with excellent coating stability in boiling nitric, and fluorinated nitric acid. The results of the present study revealed that tantalum coating by ASPS is a promising strategy for improving the corrosion resistance in the highly corrosive reprocessing environment.

Enhanced degradation of Herbicide Isoproturon in wheat rhizosphere by salicylic acid.

PubMed

Lu, Yi Chen; Zhang, Shuang; Miao, Shan Shan; Jiang, Chen; Huang, Meng Tian; Liu, Ying; Yang, Hong

2015-01-14

This study investigated the herbicide isoproturon (IPU) residues in soil, where wheat was cultivated and sprayed with salicylic acid (SA). Provision of SA led to a lower level of IPU residues in rhizosphere soil compared to IPU treatment alone. Root exudation of tartaric acid, malic acid, and oxalic acids was enhanced in rhizosphere soil with SA-treated wheat. We examined the microbial population (e.g., biomass and phospholipid fatty acid), microbial structure, and soil enzyme (catalase, phenol oxidase, and dehydrogenase) activities, all of which are associated with soil activity and were activated in rhizosphere soil of SA-treated wheat roots. We further assessed the correlation matrix and principal component to figure out the association between the IPU degradation and soil activity. Finally, six IPU degraded products (derivatives) in rhizosphere soil were characterized using ultraperformance liquid chromatography with a quadrupole-time-of-flight tandem mass spectrometer (UPLC/Q-TOF-MS/MS). A relatively higher level of IPU derivatives was identified in soil with SA-treated wheat than in soil without SA-treated wheat plants.

Low emissivity Ag/Ta/glass multilayer thin films deposited by sputtering

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

Park, Sun Ho; Lee, Kee Sun; Green Home Energy Technology Center, Cheonan City

Ta is deposited on a glass substrate as an interlayer for the two-dimensional growth of Ag thin films because Ta has good thermal stability and can induce a negative surface-energy change in Ag/glass. From the transmission electron microscopy results, we concluded that the Ag crystals in the bottom layer (seemingly on Ag/Ta) were flattened; this was rarely observed in the three-dimensional growth mode. Comparing Ag/Ta/glass with Ag/glass, we found that the Ta interlayer was effective in reducing both the resistance and the emissivity, accompanied by the relatively high transmittance in the visible region. In particular, Ag(9 nm)/Ta(1 nm)/glass film showedmore » 0.08 of the emissivity, including {approx}61% of the transmittance in the visible region (wavelength: 550 nm).« less

Fluorescent carbon nanodots for sensitive and selective detection of tannic acid in wines.

PubMed

Ahmed, Gaber Hashem Gaber; Laíño, Rosana Badía; Calzón, Josefa Angela García; García, Marta Elena Díaz

2015-01-01

Herein we describe an easy one step synthesis of carbon nanodots (C-dots) by thermal carbonization of 6-bromohexylboronic acid using two different amine compounds, polyethyleneglycol bis(3-aminopropyl (PEGA) and 1,2-aminopropane (DPA), at 180 °C in atmospheric oxygen. The as-synthesized C-dots were characterized by FTIR, HRTEM, NMR and fluorescence. The C-dots prepared using PEGA showed a strong emission at 440 nm with excitation at 362 nm. These C-dots exhibited analytical potential as sensing probes for tannic acid (TA) determination. pH effect, interferences, and analytical performance of the method were investigated. The method was found effective in the linear concentration range from 0.1 to 10 mg L(-1) TA achieving a limit of detection equal 0.018 mg L(-1) TA. The applicability of the method was demonstrated by direct measurements of TA in red and white wine samples. Validation of the method was achieved by spiking the wine samples with different standard TA concentrations obtaining recoveries in the range (90-112.5%). A probable mechanism by which TA quenched the C-dots fluorescence was proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

HPLC method for the simultaneous quantification of the major organic acids in Angeleno plum fruit

NASA Astrophysics Data System (ADS)

Wang, Yanwei; Wang, Jing; Cheng, Wei; Zhao, Zhilei; Cao, Jiankang

2014-08-01

A method was developed to profile major organic acids in Angeleno fruit by high performance liquid chromatography. Organic acids in plum were extracted by water with ultra- sonication at 50°C for 30 min. The extracts were chromatographed on Waters Atlantis T3 C18 column (4.6 mm×250 mm, 5 μm) with 0.01mol/L sulfuric acid and water as mobile phase, and flow rate was 0.5 ml/min. The column temperature was 40C, and chromatography was monitored by a diode array detector at 210 nm. The result showed that malic acid, citric acid, tartaric acid, oxalic acid, pyruvic acid, acetic acid, succinic acid in Angeleno plum, and the malic acid was the major organic acids. The coefficient of determination of the standard calibration curve is R2 > 0.999. The organic acids recovery ranged from 99.11% for Malic acid to 106.70% for Oxalic acid, and CV (n=6) ranged from 0.95% for Malic acid to 6.23% for Oxalic acid, respectively. The method was accurate, sensitive and feasible in analyzing the organic acids in Angeleno plum.

Growth of <111>-oriented Cu layer on thin TaWN films

NASA Astrophysics Data System (ADS)

Takeyama, Mayumi B.; Sato, Masaru

2017-07-01

In this study, we examine the growth of a <111>-oriented Cu layer on a thin TaWN ternary alloy barrier for good electromigration reliability. The strongly preferentially oriented Cu(111) layer is observed on a thin TaWN barrier even in the as-deposited Cu (100 nm)/TaWN (5 nm)/Si system. Also, this system tolerates annealing at 700 °C for 1 h without silicide reaction. It is revealed that the TaWN film is one of the excellent barriers with thermal stability and low resistivity. Simultaneously, the TaWN film is a candidate for a superior underlying material to achieve the Cu(111) preferential orientation.

Efficient Visible-Light-Driven Z-Scheme Overall Water Splitting Using a MgTa2O(6-x)N(y)/TaON Heterostructure Photocatalyst for H2 Evolution.

PubMed

Chen, Shanshan; Qi, Yu; Hisatomi, Takashi; Ding, Qian; Asai, Tomohiro; Li, Zheng; Ma, Su Su Khine; Zhang, Fuxiang; Domen, Kazunari; Li, Can

2015-07-13

An (oxy)nitride-based heterostructure for powdered Z-scheme overall water splitting is presented. Compared with the single MgTa2O(6-x)N(y) or TaON photocatalyst, a MgTa2O(6-x)N(y)/TaON heterostructure fabricated by a simple one-pot nitridation route was demonstrated to effectively suppress the recombination of carriers by efficient spatial charge separation and decreased defect density. By employing Pt-loaded MgTa2O(6-x)N(y)/TaON as a H2-evolving photocatalyst, a Z-scheme overall water splitting system with an apparent quantum efficiency (AQE) of 6.8% at 420 nm was constructed (PtO(x)-WO3 and IO3(-)/I(-) pairs were used as an O2-evolving photocatalyst and a redox mediator, respectively), the activity of which is circa 7 or 360 times of that using Pt-TaON or Pt-MgTa2O(6-x)N)y) as a H2-evolving photocatalyst, respectively. To the best of our knowledge, this is the highest AQE among the powdered Z-scheme overall water splitting systems ever reported. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Visible Light Assisted Photocatalytic Hydrogen Generation by Ta 2O 5/Bi 2O 3, TaON/Bi 2O 3, and Ta 3N 5/Bi 2O 3 Composites

DOE PAGES

Adhikari, Shiba; Hood, Zachary D.; More, Karren Leslie; ...

2015-06-15

Composites comprised of two semiconducting materials with suitable band gaps and band positions have been reported to be effective at enhancing photocatalytic activity in the visible light region of the electromagnetic spectrum. Here, we report the synthesis, complete structural and physical characterizations, and photocatalytic performance of a series of semiconducting oxide composites. UV light active tantalum oxide (Ta2O5) and visible light active tantalum oxynitride (TaON) and tantalum nitride (Ta 3N 5) were synthesized, and their composites with Bi 2O 3 were prepared in situ using benzyl alcohol as solvent. The composite prepared using equimolar amounts of Bi 2O 3 andmore » Ta 2O 5 leads to the formation of the ternary oxide, bismuth tantalate (BiTaO 4) upon calcination at 1000 °C. The composites and single phase bismuth tantalate formed were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) surface area measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectroscopy, and photoluminescence. The photocatalytic activities of the catalysts were evaluated for generation of hydrogen using aqueous methanol solution under visible light irradiation (λ ≥ 420 nm). The results show that as-prepared composite photocatalysts extend the light absorption range and restrict photogenerated charge-carrier recombination, resulting in enhanced photocatalytic activity compared to individual phases. The mechanism for the enhanced photocatalytic activity for the heterostructured composites is elucidated based on observed activity, band positions calculations, and photoluminescence data.« less

Developing tTA Transgenic Rats for Inducible and Reversible Gene Expression

PubMed Central

Zhou, Hongxia; Huang, Cao; Yang, Min; Landel, Carlisle P; Xia, Pedro Yuxing; Liu, Yong-Jian; Xia, Xu Gang

2009-01-01

To develop transgenic lines for conditional expression of desired genes in rats, we generated several lines of the transgenic rats carrying the tetracycline-controlled transactivator (tTA) gene. Using a vigorous, ubiquitous promoter to drive the tTA transgene, we obtained widespread expression of tTA in various tissues. Expression of tTA was sufficient to strongly activate its reporter gene, but was below the toxicity threshold. We examined the dynamics of Doxycycline (Dox)-regulated gene expression in transgenic rats. In the two transmittable lines, tTA-mediated activation of the reporter gene was fully subject to regulation by Dox. Dox dose-dependently suppressed tTA-activated gene expression. The washout time for the effects of Dox was dose-dependent. We tested a complex regime of Dox administration to determine the optimal effectiveness and washout duration. Dox was administered at a high dose (500 μg/ml in drinking water) for two days to reach the effective concentration, and then was given at a low dose (20 μg/ml) to maintain effectiveness. This regimen of Dox administration can achieve a quick switch between ON and OFF statuses of tTA-activated gene expression. In addition, administration of Dox to pregnant rats fully suppressed postnatal tTA-activated gene expression in their offspring. Sufficient levels of Dox are present in mother's milk to produce maximal efficacy in nursing neonates. Administration of Dox to pregnant or nursing rats can provide a continual suppression of tTA-dependent gene expression during embryonic and postnatal development. The tTA transgenic rat allows for inducible and reversible gene expression in the rat; this important tool will be valuable in the development of genetic rat models of human diseases. PMID:19214245

Uptake of Alkylamines on Dicarboxylic Acids Relevant to Secondary Organic Aerosol Formation

NASA Astrophysics Data System (ADS)

Marrero-Ortiz, W.; Secrest, J.; Zhang, R.

2017-12-01

Aerosols play a critical role in climate directly by scattering and absorbing solar radiation, and indirectly by functioning as cloud condensation nuclei (CCN); both represent the largest uncertainties in climate predictions. New particle formation contributes significantly to CCN production; however, the mechanisms related to particle nucleation and growth processes are not well understood. Organic acids are atmospherically abundant, and their neutralization by low molecular weight amines may result in the formation of stable low volatility aminium salt products contributing to the growth of secondary organic aerosols and even the alteration of the aerosol properties. The acid-base neutralization of particle phase succinic acid and tartaric acid by low molecular weight aliphatic amines, i.e. methylamine, dimethylamine, and trimethylamine, has been investigated by employing a low-pressure fast flow reactor at 298K with an ion drift - chemical ionization mass spectrometer (ID-CIMS). The heterogeneous uptake is time dependent and influenced by organic acids functionality, alkylamines basicity, and steric effect. The implications of our results to atmospheric nanoparticle growth will be discussed.

TaDIR1-2, a Wheat Ortholog of Lipid Transfer Protein AtDIR1 Contributes to Negative Regulation of Wheat Resistance against Puccinia striiformis f. sp. tritici

PubMed Central

Ahmed, Soyed M.; Liu, Peng; Xue, Qinghe; Ji, Changan; Qi, Tuo; Guo, Jia; Guo, Jun; Kang, Zhensheng

2017-01-01

Very few LTPs have been shown to act through plasma membrane receptors or to be involved in the hypersensitive response (HR). DIR1, a new type of plant LTP interacts with lipids in vitro, moves to distant tissues during systemic acquired resistance (SAR) and therefore is thought to be involved in long-distance signaling during SAR. However, the exact functions of DIR1 orthologs in cereal species under biotic and abiotic stresses have not been thoroughly defined. In this study, a novel wheat ortholog of the DIR1 gene, TaDIR1-2, was isolated from Suwon11, a Chinese cultivar of wheat and functionally characterized. Phylogenetic analysis indicated that TaDIR1-2 is clustered within the nsLTP-Type II group and shows a closer relationship with DIR1 orthologs from monocots than from eudicots. TaDIR1-2 was localized in the cytoplasm and the cell membrane of wheat mesophyll protoplast. Transcription of TaDIR1-2 was detected in wheat roots, stems and leaves. TaDIR1-2 transcript was significantly induced during the compatible interaction of wheat with the stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst). Treatments with salicylic acid (SA) and low temperature significantly up-regulated the expression of TaDIR1-2. Transient overexpression of TaDIR1-2 did not induce cell death or suppress Bax-induced cell death in tobacco leaves. Knocking down the expression of TaDIR1-2 through virus-induced gene silencing increased wheat resistance to Pst accompanied by HR, increased accumulation of H2O2 and SA, increased expression of TaPR1, TaPR2, TaPAL, and TaNOX, and decreased expression of two reactive oxygen species (ROS) scavenging genes TaCAT and TaSOD. Our results suggest that TaDIR1-2 acts as a negative regulator in wheat resistance to Pst by modulating ROS and/or SA-induced signaling. PMID:28443114

New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta2OsB2 and TaRuB

NASA Astrophysics Data System (ADS)

Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W. G.; Gladisch, Fabian C.; Fokwa, Boniface P. T.

2016-10-01

The new ternary transition metal-rich borides Ta2OsB2 and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta2OsB2 and TaRuB crystallize in the tetragonal Nb2OsB2 (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B2-dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta2OsB2 through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B4- or B2-units are predicted, the former being the most thermodynamically stable modification.

Evolution of resistive switching mechanism through H2O2 sensing by using TaOx-based material in W/Al2O3/TaOx/TiN structure

NASA Astrophysics Data System (ADS)

Chakrabarti, Somsubhra; Panja, Rajeswar; Roy, Sourav; Roy, Anisha; Samanta, Subhranu; Dutta, Mrinmoy; Ginnaram, Sreekanth; Maikap, Siddheswar; Cheng, Hsin-Ming; Tsai, Ling-Na; Chang, Ya-Ling; Mahapatra, Rajat; Jana, Debanjan; Qiu, Jian-Tai; Yang, Jer-Ren

2018-03-01

Understanding of resistive switching mechanism through H2O2 sensing and improvement of switching characteristics by using TaOx-based material in W/Al2O3/TaOx/TiN structure have been reported for the first time. Existence of amorphous Al2O3/TaOx layer in the RRAM devices has been confirmed by transmission electron microscopy. By analyzing the oxidation states of Ta2+/Ta5+ for TaOx switching material and W0/W6+ for WOx layer at the W/TaOx interface through X-ray photoelectron spectroscopy and H2O2 sensing, the reduction-oxidation mechanism under Set/Reset occurs only in the TaOx layer for the W/Al2O3/TaOx/TiN structures. This leads to higher Schottky barrier height at the W/Al2O3 interface (0.54 eV vs. 0.46 eV), higher resistance ratio, and long program/erase endurance of >108 cycles with 100 ns pulse width at a low operation current of 30 μA. Stable retention of more than 104 s at 85 °C is also obtained. Using conduction mechanism and reduction-oxidation reaction, current-voltage characteristic has been simulated. Both TaOx and WOx membranes have high pH sensitivity values of 47.65 mV/pH and 49.25 mV/pH, respectively. Those membranes can also sense H2O2 with a low concentration of 1 nM in an electrolyte-insulator-semiconductor structure because of catalytic activity, while the Al2O3 membrane does not show sensing. The TaOx material in W/Al2O3/TaOx/TiN structure does not show only a path towards high dense, small size memory application with understanding of switching mechanism but also can be used for H2O2 sensors.

Survival of nature's rarest isotope {sup 180}Ta under stellar conditions

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

Mohr, P.; Kaeppeler, F.; Gallino, R.

2007-01-15

The nucleosynthesis of nature's rarest isotope {sup 180}Ta depends sensitively on the temperature of the astrophysical environment because of depopulation of the long-living isomeric state via intermediate states to the short-living ground state by thermal photons. Reaction rates for this transition have been measured in the laboratory. These ground state rates underestimate the stellar rates dramatically because under stellar conditions intermediate states are mainly populated by excitations from thermally excited states in {sup 180m}Ta. Full thermalization of {sup 180}Ta is already achieved for typical s-process temperatures around kT=25 keV. Consequently, for the survival of {sup 180}Ta in the s-process fastmore » convective mixing is required which has to transport freshly synthesized {sup 180}Ta to cooler regions. In supernova explosions {sup 180}Ta is synthesized by photon- or neutrino-induced reactions at temperatures above T{sub 9}=1 in thermal equilibrium; independent of the production mechanism, freeze-out from thermal equilibrium occurs at kT{approx_equal}40 keV, and only 35{+-}4% of the synthesized {sup 180}Ta survive in the isomeric state.« less

Vibrational properties of TaW alloy using modified embedded atom method potential

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

Chand, Manesh, E-mail: maneshchand@gmail.com; Uniyal, Shweta; Joshi, Subodh

2016-05-06

Force-constants up to second neighbours of pure transition metal Ta and TaW alloy are determined using the modified embedded atom method (MEAM) potential. The obtained force-constants are used to calculate the phonon dispersion of pure Ta and TaW alloy. As a further application of MEAM potential, the force-constants are used to calculate the local vibrational density of states and mean square thermal displacements of pure Ta and W impurity atoms with Green’s function method. The calculated results are found to be in agreement with the experimental measurements.

Functional Conservation and Divergence among Homoeologs of TaSPL20 and TaSPL21, Two SBP-Box Genes Governing Yield-Related Traits in Hexaploid Wheat1[OPEN

PubMed Central

Mao, Xinguo; Li, Ang; Wang, Jingyi; Chang, Xiaoping; Zhang, Xueyong

2017-01-01

Maintaining high and stable yields has become an increasing challenge in wheat breeding due to climate change. Although Squamosa-promoter binding protein (SBP)-box genes have important roles in plant development, very little is known about the actual biological functions of wheat SBP-box family members. Here, we dissect the functional conservation, divergence, and exploitation of homoeologs of two paralogous TaSPL wheat loci during domestication and breeding. TaSPL20 and TaSPL21 were highly expressed in the lemma and palea. Ectopic expressions of TaSPL20/21 in rice exhibited similar functions in terms of promoting panicle branching but had different functions during seed development. We characterized all six TaSPL20/21 genes located across the three homoeologous (A, B, and D) genomes. According to the functional analysis of naturally occurring variants in 20 environments, four favorable haplotypes were identified. Together, they reduced plant height by up to 27.5%, and TaSPL21-6D-HapII increased 1000-grain weight by 9.73%. Our study suggests that TaSPL20 and TaSPL21 homoeologs underwent diversification in function with each evolving its own distinctive characteristics. During domestication and breeding of wheat in China, favorable haplotypes of each set were selected and exploited to varying degrees due to their large effects on plant height and 1000-grain weight. PMID:28424214

Dependence of Interfacial Dzyaloshinskii-Moriya Interaction on Layer Thicknesses in Ta /Co -Fe -B /TaOx Heterostructures from Brillouin Light Scattering

NASA Astrophysics Data System (ADS)

Chaurasiya, Avinash Kumar; Choudhury, Samiran; Sinha, Jaivardhan; Barman, Anjan

2018-01-01

The interfacial Dzyaloshinskii-Moriya interaction (IDMI) has recently drawn extensive research interest due to its fundamental role in stabilizing chiral spin textures in ultrathin ferromagnets, which are suitable candidates for future magnetic-memory devices. Here, we explore the ferromagnetic and heavy-metal layer-thickness dependence of IDMI in technologically important Ta /Co20Fe60B20/TaOx heterostructures by measuring nonreciprocity in spin-wave frequency using the Brillouin light-scattering technique. The observed value of the IDMI constant agrees with that obtained from a separate measurement of in-plane angular dependence of frequency nonreciprocity, which is also in good agreement with the theory predicted by Cortes-Ortuno and Landeros. Linear scaling behavior of IDMI with the inverse of Co-Fe-B thicknesses suggests that IDMI originates primarily from the interface in these heterostructures, whereas we observe a weak dependence of Ta thickness on the strength of IDMI. Importantly, the observed value of the IDMI constant is reasonably large by a factor of 3 compared to annealed Ta /Co -Fe -B /MgO heterostructures. We propose that the observation of large IDMI is likely due to the absence of boron diffusion towards the Ta /Co -Fe -B interface as the heterostructures are as deposited. Our detailed investigation opens up a route to designing thin-film heterostructures with the tailored IDMI constant for controlling Skyrmion-based magnetic-memory devices.

The vacuolar channel VvALMT9 mediates malate and tartrate accumulation in berries of Vitis vinifera.

PubMed

De Angeli, Alexis; Baetz, Ulrike; Francisco, Rita; Zhang, Jingbo; Chaves, Maria Manuela; Regalado, Ana

2013-08-01

Vitis vinifera L. represents an economically important fruit species. Grape and wine flavour is made from a complex set of compounds. The acidity of berries is a major parameter in determining grape berry quality for wine making and fruit consumption. Despite the importance of malic and tartaric acid (TA) storage and transport for grape berry acidity, no vacuolar transporter for malate or tartrate has been identified so far. Some members of the aluminium-activated malate transporter (ALMT) anion channel family from Arabidopsis thaliana have been shown to be involved in mediating malate fluxes across the tonoplast. Therefore, we hypothesised that a homologue of these channels could have a similar role in V. vinifera grape berries. We identified homologues of the Arabidopsis vacuolar anion channel AtALMT9 through a TBLASTX search on the V. vinifera genome database. We cloned the closest homologue of AtALMT9 from grape berry cDNA and designated it VvALMT9. The expression profile revealed that VvALMT9 is constitutively expressed in berry mesocarp tissue and that its transcription level increases during fruit maturation. Moreover, we found that VvALMT9 is targeted to the vacuolar membrane. Using patch-clamp analysis, we could show that, besides malate, VvALMT9 mediates tartrate currents which are higher than in its Arabidopsis homologue. In summary, in the present study we provide evidence that VvALMT9 is a vacuolar malate channel expressed in grape berries. Interestingly, in V. vinifera, a tartrate-producing plant, the permeability of the channel is apparently adjusted to TA.

Using the TA to Prepare Graduate Students for Research and Employment

NASA Astrophysics Data System (ADS)

Heller, Kenneth

One of the most underused components of the physics graduate program is the time spent being a teaching assistant (TA). Often the TA duties consist of grading and trying to help undergraduates survive a physics course. How those duties are accomplished is left to each TA. The most common TA preparation, if it exists, has a narrow focus on the class being taught. Preparation consists of describing, or perhaps practicing, specific teaching skills and gaining familiarity with the equipment used in the laboratory portion of the class. Instead TAs can be integrated into the entire course in which they function so that they learn the course as a system. This means treating a course in the same way one approaches a research project with the TAs as members of the research team headed by a faculty advisor. TA preparation is broadened and support includes the management, teamwork, and communication skills necessary. This makes the TAs more efficient and effective teachers while explicitly connecting the TA experience to the ``soft'' skills they need in their own research careers whether in industry, national laboratories, or academia. This talk describes such a program, functioning for over 20 years at the University of Minnesota, that takes no more time than the usual TA but results in graduate students that are more satisfied with their TA experience, are better prepared to function in research groups, and provide a better classroom experience for their undergraduate students.

TaER Expression Is Associated with Transpiration Efficiency Traits and Yield in Bread Wheat

PubMed Central

Zheng, Jiacheng; Yang, Zhiyuan; Madgwick, Pippa J.; Carmo-Silva, Elizabete; Parry, Martin A. J.; Hu, Yin-Gang

2015-01-01

ERECTA encodes a receptor-like kinase and is proposed as a candidate for determining transpiration efficiency of plants. Two genes homologous to ERECTA in Arabidopsis were identified on chromosomes 6 (TaER2) and 7 (TaER1) of bread wheat (Triticum aestivum L.), with copies of each gene on the A, B and D genomes of wheat. Similar expression patterns were observed for TaER1 and TaER2 with relatively higher expression of TaER1 in flag leaves of wheat at heading (Z55) and grain-filling (Z73) stages. Significant variations were found in the expression levels of both TaER1 and TaER2 in the flag leaves at both growth stages among 48 diverse bread wheat varieties. Based on the expression of TaER1 and TaER2, the 48 wheat varieties could be classified into three groups having high (5 varieties), medium (27 varieties) and low (16 varieties) levels of TaER expression. Significant differences were also observed between the three groups varying for TaER expression for several transpiration efficiency (TE)- related traits, including stomatal density (SD), transpiration rate, photosynthetic rate (A), instant water use efficiency (WUEi) and carbon isotope discrimination (CID), and yield traits of biomass production plant-1 (BYPP) and grain yield plant-1 (GYPP). Correlation analysis revealed that the expression of TaER1 and TaER2 at the two growth stages was significantly and negatively associated with SD (P<0.01), transpiration rate (P<0.05) and CID (P<0.01), while significantly and positively correlated with flag leaf area (FLA, P<0.01), A (P<0.05), WUEi (P<0.05), BYPP (P<0.01) and GYPP (P<0.01), with stronger correlations for TaER1 than TaER2 and at grain-filling stage than at heading stage. These combined results suggested that TaER involved in development of transpiration efficiency -related traits and yield in bread wheat, implying a function for TaER in regulating leaf development of bread wheat and contributing to expression of these traits. Moreover, the results indicate

TaER Expression Is Associated with Transpiration Efficiency Traits and Yield in Bread Wheat.

PubMed

Zheng, Jiacheng; Yang, Zhiyuan; Madgwick, Pippa J; Carmo-Silva, Elizabete; Parry, Martin A J; Hu, Yin-Gang

2015-01-01

ERECTA encodes a receptor-like kinase and is proposed as a candidate for determining transpiration efficiency of plants. Two genes homologous to ERECTA in Arabidopsis were identified on chromosomes 6 (TaER2) and 7 (TaER1) of bread wheat (Triticum aestivum L.), with copies of each gene on the A, B and D genomes of wheat. Similar expression patterns were observed for TaER1 and TaER2 with relatively higher expression of TaER1 in flag leaves of wheat at heading (Z55) and grain-filling (Z73) stages. Significant variations were found in the expression levels of both TaER1 and TaER2 in the flag leaves at both growth stages among 48 diverse bread wheat varieties. Based on the expression of TaER1 and TaER2, the 48 wheat varieties could be classified into three groups having high (5 varieties), medium (27 varieties) and low (16 varieties) levels of TaER expression. Significant differences were also observed between the three groups varying for TaER expression for several transpiration efficiency (TE)- related traits, including stomatal density (SD), transpiration rate, photosynthetic rate (A), instant water use efficiency (WUEi) and carbon isotope discrimination (CID), and yield traits of biomass production plant-1 (BYPP) and grain yield plant-1 (GYPP). Correlation analysis revealed that the expression of TaER1 and TaER2 at the two growth stages was significantly and negatively associated with SD (P<0.01), transpiration rate (P<0.05) and CID (P<0.01), while significantly and positively correlated with flag leaf area (FLA, P<0.01), A (P<0.05), WUEi (P<0.05), BYPP (P<0.01) and GYPP (P<0.01), with stronger correlations for TaER1 than TaER2 and at grain-filling stage than at heading stage. These combined results suggested that TaER involved in development of transpiration efficiency -related traits and yield in bread wheat, implying a function for TaER in regulating leaf development of bread wheat and contributing to expression of these traits. Moreover, the results indicate

21 CFR 341.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... administration. It contains, in addition to the active ingredient(s), mixtures of acids (citric acid, tartaric acid) and sodium bicarbonate, which release carbon dioxide when dissolved in water. [51 FR 35339, Oct...

21 CFR 341.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... administration. It contains, in addition to the active ingredient(s), mixtures of acids (citric acid, tartaric acid) and sodium bicarbonate, which release carbon dioxide when dissolved in water. [51 FR 35339, Oct...

21 CFR 341.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... administration. It contains, in addition to the active ingredient(s), mixtures of acids (citric acid, tartaric acid) and sodium bicarbonate, which release carbon dioxide when dissolved in water. [51 FR 35339, Oct...

21 CFR 341.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... administration. It contains, in addition to the active ingredient(s), mixtures of acids (citric acid, tartaric acid) and sodium bicarbonate, which release carbon dioxide when dissolved in water. [51 FR 35339, Oct...

[Antimutagenic action of superoxide dismutase on sodium azide- and nitrosoguanidine-induced mutagenesis in Salmonella typhimurium TA 1535].

PubMed

Vorob'eva, L I; Cherdyntseva, T A; Aver'ianov, A A; Abilev, S K

1993-05-01

It was shown that superoxide dismutase (SOD) decreased the mutagenic action of sodium azide (NaN3) and N-methyl-N'-nitro-N-nitrosoguanidine in Salmonella typhimurium TA1535. Catalase and quenchers of hydroxyl radicals showed, unlike SOD no effect on the mutagenicity of NaN3. Cell extract from propionic acid bacteria also possessed the antimutagenic activity, only partially depending on the SOD activity.

Processing and characterization of zeta-Ta4C 3-x: A high toughness tantalum carbide

NASA Astrophysics Data System (ADS)

Sygnatowicz, Michael M.

Tantalum carbides are commonly processed by hot-pressing, canned hot-isostatic-pressing, or spark-plasma sintering because of their high melting temperatures and low diffusivities. This study reports processing of dense ζ-Ta4C 3-x by reaction sintering of a Ta and TaC powder mixture (C/Ta atomic ratio = 0.66). ζ-Ta4C3-x is of interest due to its rhombohedral (trigonal) crystal structure that may be characterized as a polytype with both face-centered-cubic (fcc) and hexagonal-close-packed (hcp) Ta stacking sequences interrupted by stacking faults and missing carbon layers. This structure leads to easy cleaving on the basal planes and high fracture toughness. A key step in processing is the hydrogenation of the Ta powder to produce beta-TaH x, a hard and brittle phase that enables efficient comminution during milling and production of small, equiaxed Ta particles that can be packed to high green density with the TaC powder. Studies of phase evolution by quantitative X-ray diffraction during sintering revealed several intermediate reactions: (a) decomposition of beta-TaHx to Ta, (b) diffusion of C from gamma-TaC to Ta leading to the formation of α-Ta2Cy' with the kinetics described by the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation with an exponent, n = 0.5, and an activation energy of 221 kJ/mole, (c) equilibration of α-Ta2Cy' and gamma-TaC 0.78 phases, and (d) formation of ζ-Ta4C2.56 from the equilibrated α-Ta2C and gamma-TaC0.78 phases with the kinetics characterized by a higher JMAK exponent ( n ≈ 3) and higher activation energy (1089 kJ/mole). The microstructure showed evidence of nucleation and growth of the ζ-Ta4C 2.56 phase in both the α-Ta2C and gamma-TaC0.78 parent phases with distinct difference in the morphology due to the different number of variants of the habit plane. A hot-pressed and hot-isostatic-pressed (HIPed) material (C/Ta atomic ratio = 0.66), having formed 95 w% ζ-phase, attained a fracture toughness of 15.6 +/- 0.5 MPa√m and a

Electrochemical Corrosion Behavior of Ta2N Nanoceramic Coating in Simulated Body Fluid

PubMed Central

Cheng, Jian; Xu, Jiang; Liu, Lin Lin; Jiang, Shuyun

2016-01-01

In order to improve the corrosion and wear resistance of biomedical Ti-6Al-4V implants, a Ta2N nanoceramic coating was synthesized on a Ti-6Al-4V substrate by the double glow discharge plasma process. The Ta2N coating, composed of fine nanocrystals, with an average grain size of 12.8 nm, improved the surface hardness of Ti-6Al-4V and showed good contact damage tolerance and good adhesion strength to the substrate. The corrosion resistance of the Ta2N coating in Ringer’s physiological solution at 37 °C was evaluated by different electrochemical techniques: potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), potentiostatic polarization and capacitance measurements (Mott-Schottky approach). The evolution of the surface composition of the passive films at different applied potentials was determined by X-ray photoelectron spectroscopy (XPS). The results indicated that the Ta2N coating showed higher corrosion resistance than both commercially pure Ta and uncoated Ti-6Al-4V in this solution, because of the formed oxide film on the Ta2N coating having a smaller carrier density (Nd) and diffusivity (Do) of point defects. The composition of the surface passive film formed on the Ta2N coating changed with the applied potential. At low applied potentials, the oxidation of the Ta2N coating led to the formation of tantalum oxynitride (TaOxNy) but, subsequently, the tantalum oxynitride (TaOxNy) could be chemically converted to Ta2O5 at higher applied potentials. PMID:28773893

21 CFR 163.112 - Breakfast cocoa.

Code of Federal Regulations, 2012 CFR

2012-04-01

... oxide, used as such, or in aqueous solution; (2) Neutralizing agents. Phosphoric acid, citric acid and L-tartaric acid, used as such, or in aqueous solution; (3) Spices, natural and artificial flavorings, and...

21 CFR 163.112 - Breakfast cocoa.

Code of Federal Regulations, 2014 CFR

2014-04-01

... oxide, used as such, or in aqueous solution; (2) Neutralizing agents. Phosphoric acid, citric acid and L-tartaric acid, used as such, or in aqueous solution; (3) Spices, natural and artificial flavorings, and...

21 CFR 163.112 - Breakfast cocoa.

Code of Federal Regulations, 2013 CFR

2013-04-01

... oxide, used as such, or in aqueous solution; (2) Neutralizing agents. Phosphoric acid, citric acid and L-tartaric acid, used as such, or in aqueous solution; (3) Spices, natural and artificial flavorings, and...

Determination of organic acids by high-performance liquid chromatography with electrochemical detection during wine brewing.

PubMed

Kotani, Akira; Miyaguchi, Yuji; Tomita, Eiji; Takamura, Kiyoko; Kusu, Fumiyo

2004-03-24

Voltammetric determination of acids by means of the electrochemical reduction of quinone was applied to high-performance liquid chromatography (HPLC) with electrochemical detection (ED) for determining organic acids in fruit wines. A two-channel HPLC-ED system was fabricated by use of an ion-exclusion column and an electrochemical detector with a glassy carbon working electrode. Aqueous solution of 0.1 mM HClO(4) and ethanol containing 2-methyl-1,4-naphthoquinone served as a mobile phase and reagent solution, respectively. Determination of acetic, citric, lactic, malic, succinic, and tartaric acids was made by measuring the peak areas of the flow signals due to the reduction current of quinone caused by the eluted acids. The peak area was found to be linearly related to the acid amount ranging from 0.1 to 40 nmol per 20 microL injection. The present method was characterized by reproducibility with the simple and rapid procedure without derivatization of analytes. The method was shown as an effective means for following acid contents in fruit juices during fermentation with wine yeast.

Nanostructured Ti-Ta thin films synthesized by combinatorial glancing angle sputter deposition

NASA Astrophysics Data System (ADS)

Motemani, Yahya; Khare, Chinmay; Savan, Alan; Hans, Michael; Paulsen, Alexander; Frenzel, Jan; Somsen, Christoph; Mücklich, Frank; Eggeler, Gunther; Ludwig, Alfred

2016-12-01

Ti-Ta alloys are attractive materials for applications in actuators as well as biomedical implants. When fabricated as thin films, these alloys can potentially be employed as microactuators, components for micro-implantable devices and coatings on surgical implants. In this study, Ti100-x Ta x (x = 21, 30) nanocolumnar thin films are fabricated by glancing angle deposition (GLAD) at room temperature using Ti73Ta27 and Ta sputter targets. Crystal structure, morphology and microstructure of the nanostructured thin films are systematically investigated by XRD, SEM and TEM, respectively. Nanocolumns of ˜150-160 nm in width are oriented perpendicular to the substrate for both Ti79Ta21 and Ti70Ta30 compositions. The disordered α″ martensite phase with orthorhombic structure is formed in room temperature as-deposited thin films. The columns are found to be elongated small single crystals which are aligned perpendicular to the (20\\bar{4}) and (204) planes of α″ martensite, indicating that the films’ growth orientation is mainly dominated by these crystallographic planes. Laser pre-patterned substrates are utilized to obtain periodic nanocolumnar arrays. The differences in seed pattern, and inter-seed distances lead to growth of multi-level porous nanostructures. Using a unique sputter deposition geometry consisting of Ti73Ta27 and Ta sputter sources, a nanocolumnar Ti-Ta materials library was fabricated on a static substrate by a co-deposition process (combinatorial-GLAD approach). In this library, a composition spread developed between Ti72.8Ta27.2 and Ti64.4Ta35.6, as confirmed by high-throughput EDX analysis. The morphology over the materials library varies from well-isolated nanocolumns to fan-like nanocolumnar structures. The influence of two sputter sources is investigated by studying the resulting column angle on the materials library. The presented nanostructuring methods including the use of the GLAD technique along with pre-patterning and a

Tannic Acid as a Potential Modulator of Norfloxacin Resistance in Staphylococcus Aureus Overexpressing norA.

PubMed

Diniz-Silva, Helena Taina; Cirino, Isis Caroline da Silva; Falcão-Silva, Vivyanne Dos Santos; Magnani, Marciane; de Souza, Evandro Leite; Siqueira-Júnior, José P

2016-01-01

Tannins have shown inhibitory effects against pathogenic bacteria, and these properties make tannins potential modifying agents in bacterial resistance. The minimum inhibitory concentration (MIC) of tannic acid (TA), gallic acid (GA) and norfloxacin (Nor) against Staphylococcus aureus SA-1119 (NorA-effluxing strain) was determined using broth microdilution tests. To assess the modulation of antibiotic resistance, the MIC of Nor was determined in growth media with or without TA or GA at a subinhibitory concentration (1/4 MIC). The checkerboard method was performed to obtain the fractional inhibitory concentration index (FICI) for the combined application of TA and Nor. TA displayed a weak inhibitory effect (MIC 512 μg/ml) against S. aureus SA-1119, while no inhibitory effect was displayed by GA (MIC >512 μg/ml). However, when TA was tested at a subinhibitory concentration in combination with Nor, the MIC of Nor against S. aureus SA-1119 decreased from 128 to 4 μg/ml (32-fold); this effect was not observed for GA. In the checkerboard assay, the MIC of TA and Nor decreased from 512 to 128 μg/ml (4-fold) and from 128 to 8 μg/ml (16-fold), respectively. The combination of TA and Nor presented an FICI as low as 0.31, which indicates a synergistic interaction. TA is a potential agent for increasing the clinical efficacy of Nor to control resistant S. aureus. © 2016 S. Karger AG, Basel.

Nitroreductase-dependent mutagenicity of p-nitrophenylhydroxylamine and its N-acetyl and N-formyl hydroxamic acids.

PubMed

Corbett, M D; Wei, C; Corbett, B R

1985-05-01

p-Nitrophenylhydroxylamine (NPH) and two hydroxamic acids derived from it were synthesized and subjected to mutagenicity testing in Salmonella typhimurium strains TA98, TA98NR, TA1538 and TA1538NR. In addition, p-dinitrobenzene (DNB), p-nitroaniline (NA) and p-nitroacetanilide (AcNA) were simultaneously examined for mutagenic action against these four tester strains. NPH, its N-acetyl (AcNPH) and N-formyl (FoNPH) derivatives, and also DNB displayed strong mutagenic action to the nitroreductase-containing strains, TA98 and TA1538. NPH was the most potent chemical in this series against both of these strains, while the two hydroxamic acids AcNPH and FoNPH, and also DNB displayed approximately the same degree of mutagenicity. In the nitroreductase-deficient strains, TA98NR and TA1538NR, the mutagenicity of these four compounds was markedly reduced. The necessity for nitroreduction in order to activate these promutagens is fairly certain; however, the lack of mutagenicity of NA and AcNA towards all four tester strains made the interpretation of these data somewhat more complicated. Several possible bioactivation pathways were presented, with one mechanism in particular being proposed. This mechanism requires only that the strong electron-withdrawing nitro group be converted to an electron-donating group by bacterial nitroreductase. Such a mechanism is unique for the bioactivation of nitro aromatics by nitroreductase, since the enzymatic reduction need not produce the intermediary hydroxylamine metabolite.

TaCYP78A5 regulates seed size in wheat (Triticum aestivum).

PubMed

Ma, Meng; Zhao, Huixian; Li, Zhaojie; Hu, Shengwu; Song, Weining; Liu, Xiangli

2016-03-01

Seed size is an important agronomic trait and a major component of seed yield in wheat. However, little is known about the genes and mechanisms that determine the final seed size in wheat. Here, we isolated TaCYP78A5, the orthologous gene of Arabidopsis CYP78A5/KLUH in wheat, from wheat cv. Shaan 512 and demonstrated that the expression of TaCYP78A5 affects seed size. TaCYP78A5 encodes the cytochrome P450 (CYP) 78A5 protein in wheat and rescued the phenotype of the Arabidopsis deletion mutant cyp78a5. By affecting the extent of integument cell proliferation in the developing ovule and seed, TaCYP78A5 influenced the growth of the seed coat, which appears to limit seed growth. TaCYP78A5 silencing caused a 10% reduction in cell numbers in the seed coat, resulting in a 10% reduction in seed size in wheat cv. Shaan 512. By contrast, the overexpression of TaCYP78A5 increased the number of cells in the seed coat, resulting in seed enlargement of ~11-35% in Arabidopsis. TaCYP78A5 activity was positively correlated with the final seed size. However, TaCYP78A5 overexpression significantly reduced seed set in Arabidopsis, possibly due to an ovule development defect. TaCYP78A5 also influenced embryo development by promoting embryo integument cell proliferation during seed development. Accordingly, a working model of the influence of TaCYP7A5 on seed size was proposed. This study provides direct evidence that TaCYP78A5 affects seed size and is a potential target for crop improvement. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Low-temperature, high yield synthesis, and convenient isolation of the high-electron-density cluster compound Ta6Br14.8H2O for use in biomacromolecular crystallographic phase determination.

PubMed

Hay, Daniel N T; Messerle, Louis

2002-09-01

Reduction of TaBr(5) with Ga in the presence of KBr in a sealed borosilicate ampule at 400 degrees, followed by aqueous Soxhlet extraction and addition of stannous bromide and hydrobromic acid to the extract, yielded Ta(6)Br(14).8H(2)O in 80-84% yield. The new procedure provides a convenient, low temperature, high yield route to the synthesis of the title compound from inexpensive precursors.

Removal of zinc (II) ion from aqueous solution by adsorption onto activated palm midrib bio-sorbent

NASA Astrophysics Data System (ADS)

Mulana, F.; Mariana; Muslim, A.; Mohibah, M.; Halim, K. H. Ku

2018-03-01

In this paper, palm midrib that was activated with mixed citric acid and tartaric acid as biosorbent was used to remove Zn (II) ion from aqueous solution. The aim of this research is to activate palm midrib by using a mixed citric acid and tartaric acid and to determine adsorption capacity of activated palm midrib biosorbent on Zn (II) ion uptake from aqueous solution. The effect of several parameters such as contact time, initial Zn (II) ion concentration and activator concentration on the degree of Zn (II) ion removal was examined. Atomic Absorption Spectroscopy method was performed to determine adsorbed amount of Zn (II) ion into activated biosorbent. The result showed that the adsorption process was relatively not so fast and equilibrium was reached after contact time of 120 min. The adsorption capacity of biosorbent reached a maximum when the concentration of mixed citric acid and tartaric acid was 1.6 M. The optimum adsorption capacity was 5.72 mg/g. The result was obtained on initial Zn (II) ion concentration of 80 ppm for 120-min contact time. Langmuir isotherm was found as the best fit for the equilibrium data indicating homogeneous adsorption of metal ions onto the biosorbent surface.

Growth mechanisms of MgO nanocrystals via a sol-gel synthesis using different complexing agents

PubMed Central

2014-01-01

In the preparation of nanostructured materials, it is important to optimize synthesis parameters in order to obtain the desired material. This work investigates the role of complexing agents, oxalic acid and tartaric acid, in the production of MgO nanocrystals. Results from simultaneous thermogravimetric analysis (STA) show that the two different synthesis routes yield precursors with different thermal profiles. It is found that the thermal profiles of the precursors can reveal the effects of crystal growth during thermal annealing. X-ray diffraction confirms that the final products are pure, single phase and of cubic shape. It is also found that complexing agents can affect the rate of crystal growth. The structures of the oxalic acid and tartaric acid as well as the complexation sites play very important roles in the formation of the nanocrystals. The complexing agents influence the rate of growth which affects the final crystallite size of the materials. Surprisingly, it is also found that oxalic acid and tartaric acid act as surfactants inhibiting crystal growth even at a high temperature of 950°C and a long annealing time of 36 h. The crystallite formation routes are proposed to be via linear and branched polymer networks due to the different structures of the complexing agents. PMID:24650322

Skin permeation and retention of topical bead formulation containing tranexamic acid.

PubMed

Vijayakumar, Ajay; Baskaran, Rengarajan; Yoo, Bong Kyu

2017-02-01

The objective of this study is to develop a topical bead formulation of tranexamic acid (TA) which can be used concomitantly with laser treatment. The bead formulation of TA (TAB) was successfully prepared by fluidized bed drying method. Physicochemical properties of the TAB were evaluated in terms of chemical stability of TA and differential scanning calorimetry. TA in the bead was stable up to six months at 25°C and existed as amorphous state. In vitro skin permeation and in vivo skin retention of TA in the beads were significantly higher compared to a commercial product. When the bead was dissolved into distilled water and applied concomitantly with laser treatment, the amount of TA retained in the skin in the in vivo study was inversely proportional to the energy levels of laser treatment, indicating absorption into subcutaneous tissue and drainage to systemic circulation. Therefore, when laser treatment is used concomitantly with TAB, energy level should be very carefully monitored to avoid possible adverse events associated with systemic side effects of TA.

Promising Ta-Ti-Zr-Si metallic glass coating without cytotoxic elements for bio-implant applications

NASA Astrophysics Data System (ADS)

Lai, J. J.; Lin, Y. S.; Chang, C. H.; Wei, T. Y.; Huang, J. C.; Liao, Z. X.; Lin, C. H.; Chen, C. H.

2018-01-01

Tantalum (Ta) is considered as one of the most promising metal due to its high corrosion resistance, excellent biocompatibility and cell adhesion/in-growth capabilities. Although there are some researches exploring the biomedical aspects of Ta and Ta based alloys, systematic characterizations of newly developed Ta-based metallic glasses in bio-implant applications is still lacking. This study employs sputtering approach to produced thin-film Ti-based metallic glasses due to the high melting temperature of Ta (3020 °C). Two fully amorphous Ta-based metallic glasses composed of Ta57Ti17Zr15Si11 and Ta75Ti10Zr8Si7 are produced and experimentally characterized in terms of their mechanical properties, bio-corrosion properties, surface hydrophilic characteristics, and in-vitro cell viability and cells attachment tests. Compare to conventional pure Ti and Ta metals, the developed Ta-based metallic glasses exhibit higher hardness and lower modulus which are better match to the mechanical properties of bone. MTS assay results show that Ta-based metallic glasses show comparable cell viability and cell attachment rate compared to that of pure Ti and Ta surface in a 72 h in-vitro test.

The Joint Strength and Fracture Mechanisms of TC4/TC4 and TA0/TA0 Brazed with Ti-25Cu-15Ni Braze Alloy

NASA Astrophysics Data System (ADS)

Zou, Zhihuan; Zeng, Fanhao; Wu, Haobo; Liu, Jian; Li, Yi; Gu, Yi; Yuan, Tiechui; Zhang, Fuqin

2017-05-01

In this paper, Ti-25Cu-15Ni (mass ratio) braze alloys were prepared by vacuum arc melting. Additionally, the TA0 pure titanium and TC4 titanium alloy were brazed with the Ti-25Cu-15Ni braze alloy at 960, 980, 1000, 1020, and 1040 °C. The effects of the braze temperature on the tensile strength of the TA0 and TC4 joints and their fracture mechanisms were studied. The maximum tensile strength of the TA0 joints of 219.9 ± 0.1 MPa was achieved at a brazing temperature of 980 °C, and the maximum tensile strength of the TC4 joints of 832.9 ± 0.1 MPa was achieved at the same brazing temperature. These results indicate that their ideal joint strength is comparable. According to the fractography results of the TA0 joints, a mixed fracture morphology is indicated. The TA0 fracture surface is dominated by cleavage fracture with a small contribution from ductile fracture. The TC4 joint fracture arises from cleavage.

Ta-Pt Alloys as Gate Materials for Metal-Oxide-Semiconductor Field Effect Transistor Application

NASA Astrophysics Data System (ADS)

Huang, Chih-Feng; Tsui, Bing-Yue

2009-03-01

In this work we explore the thermal stability of sputter-deposited Ta-rich Ta-Pt alloys. The effects of group III and V impurities on their work function are also investigated. The Ta content ranges from 65 to 82 at. %. The main phase is σ Ta-Pt. The binding energies of core-level electrons of Ta and Pt are changed due to the intermixing of Ta and Pt, which is evidence that the work function of alloys is changed in metallic alloy systems. Binding energies are thermally stable up to 800 °C. Moreover, the incorporation of Pt in Ta film induces poor crystallization and a compound phase of Ta-Pt alloys. Transmission electron microscopy analysis confirmed the absence of a clear grain boundary in Ta-Pt alloys. The Ta and Pt depth profile shows uniformity in depth after 800 °C annealing for 30 min. The diffusion and distribution of impurities in the alloys were studied by secondary ion mass spectroscopy. Arsenic cannot diffuse in the alloys following annealing at 800 °C for 30 s. In contrast, boron can easily diffuse at 800 °C. The incorporation of impurities with a dosage of 5 ×1015 cm-2 in 60 nm Ta-Pt alloy by implantation did not significantly change the flat-band voltage following annealing at 800 °C.

Amorphization of Ta2O5 under swift heavy ion irradiation

NASA Astrophysics Data System (ADS)

Cusick, Alex B.; Lang, Maik; Zhang, Fuxiang; Sun, Kai; Li, Weixing; Kluth, Patrick; Trautmann, Christina; Ewing, Rodney C.

2017-09-01

Crystalline Ta2O5 powder is shown to amorphize under 2.2 GeV 197Au ion irradiation. Synchrotron X-ray diffraction (XRD), Raman spectroscopy, small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM) were used to characterize the structural transition from crystalline to fully-amorphous. Based on Rietveld refinement of XRD data, the initial structure is orthorhombic (P2mm) with a very large unit cell (a = 6.20, b = 40.29, c = 3.89 Å; V = 971.7 Å3), ideally containing 22 Ta and 55 O atoms. At a fluence of approximately 3 × 1011 ions/cm2, a diffuse amorphous background becomes evident, increasing in intensity relative to diffraction maxima until full amorphization is achieved at approximately 3 × 1012 ions/cm2. An anisotropic distortion of the orthorhombic structure occurred during the amorphization process, with an approximately constant unit cell volume. The amorphous phase fraction as a function of fluence was determined, yielding a trend that is consistent with a direct-impact model for amorphization. SAXS and TEM data indicate that ion tracks exhibit a core-shell morphology. Raman data show that the amorphous phase is comprised of TaO6 and TaO5 coordination-polyhedra in contrast to the TaO6 and TaO7 units that exist in crystalline Ta2O5. Analysis of Raman data shows that oxygen-deficiency increases with fluence, indicating a loss of oxygen that leads to an estimated final stoichiometry of Ta2O4.2 at a fluence of 1 × 1013 ions/cm2.

Optical spectroscopy of the Weyl semimetal TaAs

DOE PAGES

Xu, B.; Dai, Y. M.; Zhao, L. X.; ...

2016-03-24

Here, we present a systematic study of both the temperature and frequency dependence of the optical response in TaAs, a material that has recently been realized to host the Weyl semimetal state. Our study reveals that the optical conductivity of TaAs features a narrow Drude response alongside a conspicuous linear dependence on frequency. The weight of the Drude peak decreases upon cooling, following a T 2 temperature dependence, in good agreement with theoretical predictions. Two linear components with distinct slopes dominate the low-temperature optical conductivity. A comparison between our experimental results and theoretical calculations suggests that the linear conductivity belowmore » ~230 cm –1 arises purely from interband transitions near the Weyl points, providing rich information about the Weyl semimetal state in TaAs.« less

Copper-tolfenamic acid: evaluation of stability and anti-cancer activity.

PubMed

Hurtado, Myrna; Sankpal, Umesh T; Chhabra, Jaya; Brown, Deondra T; Maram, Rajasekhar; Patel, Rafid; Gurung, Raj K; Simecka, Jerry; Holder, Alvin A; Basha, Riyaz

2018-05-15

The non-steroidal anti-inflammatory drug, Tolfenamic acid (TA) acts as an anti-cancer agent in several adult and pediatric cancer models. Copper (Cu) is an important element with multiple biological functions and has gained interest in medical applications. Recently, [Cu(TA) 2 (bpy)] (Cu-TA) has been synthesized in order to enhance therapeutic activity. In this study, we synthesized Cu-TA using an established method, characterized it by UV visible spectroscopy and Fourier-transform infrared spectroscopy (FTIR), and tested its anti-cancer activity using twelve cell lines representing various cancers, such as Ewing sarcoma, glioblastoma, medulloblastoma, neuroblastoma, pancreatic and prostate. The anti-proliferative activity of Cu-TA was determined at 48 h post-treatment and compared with the parental compound, TA. The IC 50 values were calculated using GraphPad Prism software. The biological stability of Cu-TA was evaluated using twelve-month-old powder and six-month-old stock solution. Cardiomyocytes (H9C2) were used to test the cytotoxicity in non-malignant cells. Cu-TA showed higher anti-proliferative activity, and the IC 50 values were 30 to 80% lower when compared with TA. H9C2 cells were non-responsive to Cu-TA, suggesting that it is selective towards malignant cells. Comparison of the twelve-month-old powder and six-month-old stock solution using the Panc1 cell line showed similar IC 50 values (<5% variation), confirming the stability of Cu-TA either in powder or solution form. These findings demonstrate the potential of Cu-TA as an effective anti-cancer agent. Further studies to delineate the detailed mechanism of action of Cu-TA for specific cancer model are underway.

Room-Temperature and High-Temperature Tensile Mechanical Properties of TA15 Titanium Alloy and TiB Whisker-Reinforced TA15 Matrix Composites Fabricated by Vacuum Hot-Pressing Sintering

PubMed Central

Feng, Yangju; Zhang, Wencong; Zeng, Li; Cui, Guorong; Chen, Wenzhen

2017-01-01

In this paper, the microstructure, the room-temperature and high-temperature tensile mechanical properties of monolithic TA15 alloy and TiB whisker-reinforced TA15 titanium matrix composites (TiBw/TA15) fabricated by vacuum hot-pressing sintering were investigated. The microstructure results showed that there were no obvious differences in the microstructure between monolithic TA15 alloy and TiBw/TA15 composites, except whether or not the grain boundaries contained TiBw. After sintering, the matrix microstructure presented a typical Widmanstätten structure and the size of primary β grain was consistent with the size of spherical TA15 titanium metallic powders. This result demonstrated that TiBw was not the only factor limiting grain coarsening of the primary β grain. Moreover, the grain coarsening of α colonies was obvious, and high-angle grain boundaries (HAGBs) were distributed within the primary β grain. In addition, TiBw played an important role in the microstructure evolution. In the composites, TiBw were randomly distributed in the matrix and surrounded by a large number of low-angle grain boundaries (LAGBs). Globularization of α phase occurred prior, near the TiBw region, because TiBw provided the nucleation site for the equiaxed α phase. The room-temperature and high-temperature tensile results showed that TiBw distributed at the primary β grain boundaries can strengthen the grain boundary, but reduce the connectivity of the matrix. Therefore, compared to the monolithic TA15 alloy fabricated by the same process, the tensile strength of the composites increased, and the tensile elongation decreased. Moreover, with the addition of TiBw, the fracture mechanism was changed to a mixture of brittle fracture and ductile failure (composites) from ductile failure (monolithic TA15 alloy). The fracture surfaces of TiBw/TA15 composites were the grain boundaries of the primary β grain where the majority of TiB whiskers distributed, i.e., the surfaces of the

Room-Temperature and High-Temperature Tensile Mechanical Properties of TA15 Titanium Alloy and TiB Whisker-Reinforced TA15 Matrix Composites Fabricated by Vacuum Hot-Pressing Sintering.

PubMed

Feng, Yangju; Zhang, Wencong; Zeng, Li; Cui, Guorong; Chen, Wenzhen

2017-04-18

In this paper, the microstructure, the room-temperature and high-temperature tensile mechanical properties of monolithic TA15 alloy and TiB whisker-reinforced TA15 titanium matrix composites (TiBw/TA15) fabricated by vacuum hot-pressing sintering were investigated. The microstructure results showed that there were no obvious differences in the microstructure between monolithic TA15 alloy and TiBw/TA15 composites, except whether or not the grain boundaries contained TiBw. After sintering, the matrix microstructure presented a typical Widmanstätten structure and the size of primary β grain was consistent with the size of spherical TA15 titanium metallic powders. This result demonstrated that TiBw was not the only factor limiting grain coarsening of the primary β grain. Moreover, the grain coarsening of α colonies was obvious, and high-angle grain boundaries (HAGBs) were distributed within the primary β grain. In addition, TiBw played an important role in the microstructure evolution. In the composites, TiBw were randomly distributed in the matrix and surrounded by a large number of low-angle grain boundaries (LAGBs). Globularization of α phase occurred prior, near the TiBw region, because TiBw provided the nucleation site for the equiaxed α phase. The room-temperature and high-temperature tensile results showed that TiBw distributed at the primary β grain boundaries can strengthen the grain boundary, but reduce the connectivity of the matrix. Therefore, compared to the monolithic TA15 alloy fabricated by the same process, the tensile strength of the composites increased, and the tensile elongation decreased. Moreover, with the addition of TiBw, the fracture mechanism was changed to a mixture of brittle fracture and ductile failure (composites) from ductile failure (monolithic TA15 alloy). The fracture surfaces of TiBw/TA15 composites were the grain boundaries of the primary β grain where the majority of TiB whiskers distributed, i.e., the surfaces of the

Anisotropic thermal transport in Weyl semimetal TaAs: a first principles calculation.

PubMed

Ouyang, Tao; Xiao, Huaping; Tang, Chao; Hu, Ming; Zhong, Jianxin

2016-06-22

A fundamental understanding of the phonon transport property is crucial to predict the thermal management performance in micro/nano-electronic devices. By combining first principle calculations and Boltzmann phonon transport equation, we investigate thermal transport in TaAs-a typical Weyl semimetal. The lattice thermal conductivity of TaAs at room temperature was found to be 39.26 W mK(-1) and 24.78 W mK(-1) along the a(b) and c crystal axis, respectively, showing obvious anisotropy. Detailed analyses of the mode level phonon properties further revealed that the three acoustic phonon modes dominate the overall thermal transport and the major phonon scattering channels in this typical Weyl semimetal were TA1/TA2/LA + O ↔ O and A + A ↔ O. The representative phonon mean free path of TaAs was also calculated in this paper, which provide helpful guidance for the thermal management of TaAs-based electronic devices.

Stoichiometry and tribological behavior of thick Ta(N) coatings produced by direct current magnetron sputtering (DCMS)

NASA Astrophysics Data System (ADS)

Guo, Xiaotong; Niu, Yunsong; Chen, Minghui; Sun, Wenyao; Zhu, Shenglong; Wang, Fuhui

2018-01-01

Thick Ta(N) coating of 51 μm has been successfully obtained by DCMS technology. Ta(N) is a kind of distorted Ta matrix, which is inter-soluble with N-defect lattice structure, forming the disabled bcc structure. From the XRD and XPS investigations, the composition of Ta(N) coating is consisted of bcc-Ta and bcc-TaN0.06, while that of Ta coating mainly contains β-Ta phase. It can be concluded from wear test, nanoindentation test and SEM observations, wear resistance of Ta(N) coating is much better than that of Ta coating, due to its high hardness, H/E, H3/E2 value and low COF value. The wear mechanism of Ta coating is the compound fatigue and abrasive wear, while that of Ta(N) coating is transformed into adhesive wear mechanism. The secondary adhesion of the plastic deformation for the Ta(N) coating can reinforce the coated surface, to improve the load-bearing and anti-wear capacities, and thus improve the wear resistance.

Kinetics of Ta ions penetration into porous low-k dielectrics under bias-temperature stress

NASA Astrophysics Data System (ADS)

He, Ming; Ou, Ya; Wang, Pei-I.; Lu, Toh-Ming

2010-05-01

It is known that Ta, a popular diffusion barrier material, can itself penetrate into low-k dielectrics under bias-temperature stress. In this work, we derived a model which directly correlates the diffusivity of Ta ions to the rate of flatband voltage shift (FBS) of the Ta/methyl silsesquixane (MSQ)/Si capacitors. From our experimentally measured constant FBS rate, the Ta diffusivity and activation energy were determined. It appears that an increase in the porosity of MSQ film enhances the Ta diffusivity but does not affect the associated activation energy. This suggests the Ta ion diffusion is mainly through interconnected pore surfaces.

Preliminary study of the biomechanical behavior and physical characteristics of tantalum (Ta)-coated prostheses.

PubMed

Duan, Yonghong; Liu, Lie; Wang, Ling; Guo, Fei; Li, Haoping; Shi, Lei; Li, Mao; Yin, Dayu; Jiang, Chi; Zhu, Qingsheng

2012-03-01

Use of Ta biomaterials in medicine started in the middle of the last century. The good biocompatibility and chemical stability, and the unique physical characteristics of Ta metal have resulted in many possible developments of Ta biomaterials. In this study, histopathological observation, histomorphometric analysis, scanning electron microscope (SEM) observation, energy-dispersive X-ray spectroscopy (EDX) analysis, biomechanical testing, and examination of the coating's mechanical strength have been used to evaluate the value of clinical application of Ta-coated prostheses prepared by a plasma-spraying process. Histopathological observation has demonstrated that the periprosthetic new bone tissues tightly and stably adhere to the Ta coating after the implantation, with no signs of loosening. Early after implantation, there is no significant difference in periprosthetic bone volume and ultimate shear strength between Ta-coated and Ti-coated prostheses (P > 0.05). EDX analysis suggests that the ultimate shear stress does not damage Ta coating. Mechanical strength testing shows that the adhesive strength and Vicker's surface hardness (HV) of the Ta coating are significantly higher than those of the Ti coating (P < 0.01). Ta coating has good stability and bone biocompatibility; the extraordinary physical characteristics of Ta coating have great significance in maintaining prosthetic stability and surface porosity after implantation.

Magnetic, thermal, and optical properties of single-crystalline CoTa2O6 and FeTa2O6 and their anisotropic magnetocaloric effect

NASA Astrophysics Data System (ADS)

Christian, A. B.; Schye, A. T.; White, K. O.; Neumeier, J. J.

2018-05-01

The magnetic, thermal, and optical properties of single-crystalline CoTa2O6 and FeTa2O6 are reported. Optical dichroism was observed in CoTa2O6. Magnetic susceptibility χ(T) measurements reveal long-range antiferromagnetic order with Néel temperatures K and 8.11(5) K, respectively, and anisotropy in χ. The thermal expansion coefficients exhibit significant anisotropy and the influence of the magnetic ions and long-range order. A structural phase transition to orthorhombic occurs below T N for FeTa2O6. Magnetic field H lowers T N with its affect largest when H is directed along either [1 1 0] or [1  0], and smallest when directed along [0 0 1]. This leads to an anisotropic magnetocaloric effect that is investigated through measurements of the specific heat and magnetization in applied magnetic field.

D-erythroascorbic acid: Its preparations, chemistry, and metabolism (fungi and plants)

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

Loewus, F.A.; Seib, P.A.

1991-01-01

The origin of oxalate in plants has received considerable attention and glycolate metabolism has been generally regarded as a prime precursor candidate although studies on the metabolism of L-ascorbic acid single out that plant constituent as well. Experiments with oxalate-accumulating plants that contain little or no tartaric acid revealed the presence of a comparable L-ascorbic acid metabolism with the exception that the cleavage products were oxalic acid and L-threonic acid or products of L-threonic acid metabolism. A reasonable mechanism for cleavage of L-ascorbic acid at the endiolic bond is found in studies on the photooxygenation of L-ascorbic acid. Presumably, analogsmore » of L-ascorbic acid that differ only in the substituent at C4 also form a hydroperoxide in the presence of alkaline hydrogen peroxide and subsequently yield oxalic acid and the corresponding aldonic acid or its lactone. We became interested in such a possibility when we discovered that L-ascorbic acid was rare or absent in certain yeasts and fungi whereas a L-ascorbic acid analog, D-glycero-pent-2-enono- 1,4-lactone (D-erythroascorbic acid), was present. It has long been known that oxalate occurs in yeasts and fungi and its production plays a role in plant pathogenesis. As to the biosynthetic origin of fungal oxalic acid there is little information although it is generally assumed that oxaloacetate or possibly, glycolate, might be that precursor.« less

Emerging good practices for Translatability Assessment (TA) of Patient-Reported Outcome (PRO) measures.

PubMed

Acquadro, Catherine; Patrick, Donald L; Eremenco, Sonya; Martin, Mona L; Kuliś, Dagmara; Correia, Helena; Conway, Katrin

2017-01-01

This paper presents emerging Good Practices for Translatability Assessment (TA) of Patient-Reported Outcome (PRO) Measures. The ISOQOL Translation and Cultural Adaptation Special Interest Group (TCA-SIG) undertook the review of several TA approaches, with the collaboration of organizations who are involved in conducting TA, and members of the TCA-SIG. The effort led to agreement by the writing group on Good Practices for 1) the terminology to be used in referring to translatability process, 2) the best definition of TA, 3) the methodology that is recommended at each step of the process, 4) the persons involved in TA, 5) the timing of assessment, 6) the review criteria for TA, and 7) the recommendations to be made at the end of the TA process. With input from the TCA-SIG membership and in consultation with experts in the field, these emerging good practices can guide the future use of TA in the development of PROs.

Correlation between the transport mechanisms in conductive filaments inside Ta2O5-based resistive switching devices and in substoichiometric TaOx thin films

NASA Astrophysics Data System (ADS)

Rosário, Carlos M. M.; Thöner, Bo; Schönhals, Alexander; Menzel, Stephan; Wuttig, Matthias; Waser, Rainer; Sobolev, Nikolai A.; Wouters, Dirk J.

2018-05-01

Conductive filaments play a key role in redox-based resistive random access memory (ReRAM) devices based on the valence change mechanism, where the change of the resistance is ascribed to the modulation of the oxygen content in a local region of these conductive filaments. However, a deep understanding of the filaments' composition and structure is still a matter of debate. We approached the problem by comparing the electronic transport, at temperatures from 300 K down to 2 K, in the filaments and in TaOx films exhibiting a substoichiometric oxygen content. The filaments were created in Ta (15 nm)/Ta2O5 (5 nm)/Pt crossbar ReRAM structures. In the TaOx thin films with various oxygen contents, the in-plane transport was studied. There is a close similarity between the electrical properties of the conductive filaments in the ReRAM devices and of the TaOx films with x ˜ 1, evidencing also no dimensionality difference for the electrical transport. More specifically, for both systems there are two different conduction processes: one in the higher temperature range (from 50 K up to ˜300 K), where the conductivity follows a √{ T } dependence, and one at lower temperatures (<50 K), where the conductivity follows the exp(-1 / √{ T } ) dependence. This suggests a strong similarity between the material composition and structure of the filaments and those of the substoichiometric TaOx films. We also discuss the temperature dependence of the conductivity in the framework of possible transport mechanisms, mainly of those normally observed for granular metals.

K(3)TaF(8) from laboratory X-ray powder data.

PubMed

Smrcok, Lubomír; Cerný, Radovan; Boca, Miroslav; Macková, Iveta; Kubíková, Blanka

2010-02-01

The crystal structure of tripotassium octafluoridotantalate, K(3)TaF(8), determined from laboratory powder diffraction data by the simulated annealing method and refined by total energy minimization in the solid state, is built from discrete potassium cations, fluoride anions and monocapped trigonal-prismatic [TaF(7)](2-) ions. All six atoms in the asymmetric unit are in special positions of the P6(3)mc space group: the Ta and one F atom in the 2b (3m) sites, the K and two F atoms in the 6c (m) sites, and one F atom in the 2a (3m) site. The structure consists of face-sharing K(6) octahedra with a fluoride anion at the center of each octahedron, forming chains of composition [FK(3)](2+) running along [001] with isolated [TaF(7)](2-) trigonal prisms in between. The structure of the title compound is different from the reported structure of Na(3)TaF(8) and represents a new structure type.

What does nitric acid really do to carbon nanofibers? [What nitric acid really does to carbon nanofibers

DOE PAGES

Sainio, S.; Nordlund, D.; Gandhiraman, R.; ...

2016-09-15

Understanding the chemical nature of the surface of carbon nanofibers (CNF) is critical in assessing their fundamental properties and tailoring them for the right application. To gain such knowledge, we present here a detailed X-ray adsorption spectroscopy (XAS) study accompanied by high resolution transmission electron microscopy (TEM) micrographs of two morphologically different CNF pairs (tetrahedral amorphous carbon (ta-C) grown “open structured” fibers and traditional bamboo-like “closed structured” fibers), where the surface chemical properties and structural features of the fibers are investigated in depth and the effects of nitric acid treatment on the fibers are revealed. The morphology of the fibermore » and/or the original seed- and adhesion layers markedly affect the response of the fibers to the acid treatment. Results also show that the nitric acid treatment increases the observed sp 2 intensity and modifies the two types of fibers to become more-alike both structurally and with respect to their oxygen functionalities. Furthermore, the XAS and HRTEM results confirm that a short nitric acid treatment does not remove the Ni catalyst particle but, instead, oxidizes their surfaces, especially in the case of ta-C grown fibers.« less

What does nitric acid really do to carbon nanofibers? [What nitric acid really does to carbon nanofibers

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

Sainio, S.; Nordlund, D.; Gandhiraman, R.

Understanding the chemical nature of the surface of carbon nanofibers (CNF) is critical in assessing their fundamental properties and tailoring them for the right application. To gain such knowledge, we present here a detailed X-ray adsorption spectroscopy (XAS) study accompanied by high resolution transmission electron microscopy (TEM) micrographs of two morphologically different CNF pairs (tetrahedral amorphous carbon (ta-C) grown “open structured” fibers and traditional bamboo-like “closed structured” fibers), where the surface chemical properties and structural features of the fibers are investigated in depth and the effects of nitric acid treatment on the fibers are revealed. The morphology of the fibermore » and/or the original seed- and adhesion layers markedly affect the response of the fibers to the acid treatment. Results also show that the nitric acid treatment increases the observed sp 2 intensity and modifies the two types of fibers to become more-alike both structurally and with respect to their oxygen functionalities. Furthermore, the XAS and HRTEM results confirm that a short nitric acid treatment does not remove the Ni catalyst particle but, instead, oxidizes their surfaces, especially in the case of ta-C grown fibers.« less

Integrated electrochemical gluconic acid biosensor based on self-assembled monolayer-modified gold electrodes. Application to the analysis of gluconic acid in musts and wines.

PubMed

Campuzano, S; Gamella, M; Serra, B; Reviejo, A J; Pingarrón, J M

2007-03-21

An integrated amperometric gluconic acid biosensor constructed using a gold electrode (AuE) modified with a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA) on which gluconate dehydrogenase (GADH, 0.84 U) and the mediator tetrathiafulvalene (TTF, 1.5 micromol) were coimmobilized by covering the electrode surface with a dialysis membrane is reported. The working conditions selected were Eapp=+0.15 V and 25+/-1 degrees C. The useful lifetime of one single TTF-GADH-MPA-AuE was surprisingly long. After 53 days of continuous use, the biosensor exhibited 86% of the original sensitivity. A linear calibration plot was obtained for gluconic acid over the 6.0x10(-7) to 2.0x10(-5) M concentration range, with a limit of detection of 1.9x10(-7) M. The effect of potential interferents (glucose, fructose, galactose, arabinose, and tartaric, citric, malic, ascorbic, gallic, and caffeic acids) on the biosensor response was evaluated. The behavior of the biosensor in a flow-injection system in connection with amperometric detection was tested. The analytical usefulness of the biosensor was evaluated by determining gluconic acid in wine and must samples, and the results obtained were validated by comparison with those provided by using a commercial enzyme test kit.

Photo-Induced depopulation of the 180mTa isomer

NASA Astrophysics Data System (ADS)

Bhike, Megha; Krishichayan, Fnu; Tornow, W.

2015-10-01

The 180mTa nucleus is the rarest isotope in the universe, existing only in an isomeric state at 77.2 keV (Jπ = 9-) with half-life of greater than 7.1 ×1015 years. The stellar production of this high-spin isomer has been a challenging astrophysical problem. Cross-section measurements for the depopulation of the 180mTa isomer with monoenergetic photon beams of energies 2.5 and 3.1 MeV have been carried out at the HI γS facility. The activated Ta foils of natural abundance and containing 14.4 mg of 180mTa were γ-ray counted at TUNL's low background facility using a 13% planar HPGe detector. A 8'' ×12'' NaI detector in combination with the standard HI γS scintillator paddle system was employed for absolute photon-flux determination. Preliminary results will be discussed, and measurements at lower energies are planned. This work was supported by the U.S. DOE under Grant NO. DE-FG02-97ER41033.

Expression of the nuclear gene TaF(A)d is under mitochondrial retrograde regulation in anthers of male sterile wheat plants with timopheevii cytoplasm.

PubMed

Xu, Pei; Yang, Yuwen; Zhang, Zhengzhi; Chen, Weihua; Zhang, Caiqin; Zhang, Lixia; Zou, Sixiang; Ma, Zhengqiang

2008-01-01

Alterations of mitochondrial-encoded subunits of the F(o)F(1)-ATP synthase are frequently associated with cytoplasmic male sterility (CMS) in plants; however, little is known about the relationship of the nuclear encoded subunits of this enzyme with CMS. In the present study, the full cDNA of the gene TaF(A)d that encodes the putative F(A)d subunit of the F(o)F(1)-ATP synthase was isolated from the wheat (Triticum aestivum) fertility restorer '2114' for timopheevii cytoplasm-based CMS. The deduced 238 amino acid polypeptide is highly similar to its counterparts in dicots and other monocots but has low homology to its mammalian equivalents. TaF(A)d is a single copy gene in wheat and maps to the short arm of the group 6 chromosomes. Transient expression of the TaF(A)d-GFP fusion in onion epidermal cells demonstrated TaF(A)d's mitochondrial location. TaF(A)d was expressed abundantly in stem, leaf, anther, and ovary tissues of 2114. Nevertheless, its expression was repressed in anthers of CMS plants with timopheevii cytoplasm. Genic male sterility did not affect its expression in anthers. The expression of the nuclear gene encoding the 20 kDa subunit of F(o) was down-regulated in a manner similar to TaF(A)d in the T-CMS anthers while that of genes encoding the 6 kDa subunit of F(o) and the gamma subunit of F(1) was unaffected. These observations implied that TaF(A)d is under mitochondrial retrograde regulation in the anthers of CMS plants with timopheevii cytoplasm.

The Effect of Various Acids to the Gelation Process to the Silica Gel Characteristic Using Organic Silica

NASA Astrophysics Data System (ADS)

Rahman, NA; Widiyastuti, W.; Sigit, D.; Ajiza, M.; Sujana, W.

2018-01-01

Bagasse ash is solid waste of cane sugar industry which contain of silica more than 51%. Some previous study of silica gel from bagasse ash have been conducted often and been applied. This study concerns about the effect of various acid used in the process of gelation to the characteristic of silica gel produced. Then, this silica gel will be used as adsorbent. As that, the silica gel must fulfill the requirements of adsorbent, as have good pores characteristics, fit in mesoporous size so that adsorbent diffusion process is not disturbed. A fitted pores size of silica gel can be prepared by managing acid concentration used. The effect of acid, organic acid (tartaric acid) and inorganic acid (hydrochloric acid), is investigated in detail. The acid is added into sodium silicate solution in that the gel is formed, the pores structures can be investigated with BET, the crystal form is analyzed with XRD and the pore structure is analyzed visually with SEM. By managing the acid concentration added, it gets the effect of acid to the pore structure of silica gel. The bigger concentration is, the bigger the pore’s size of silica gel produced.

Magnetic, thermal, and optical properties of single-crystalline CoTa2O6 and FeTa2O6 and their anisotropic magnetocaloric effect.

PubMed

Christian, A B; Schye, A T; White, K O; Neumeier, J J

2018-05-16

The magnetic, thermal, and optical properties of single-crystalline CoTa 2 O 6 and FeTa 2 O 6 are reported. Optical dichroism was observed in CoTa 2 O 6 . Magnetic susceptibility χ(T) measurements reveal long-range antiferromagnetic order with Néel temperatures [Formula: see text] K and 8.11(5) K, respectively, and anisotropy in χ. The thermal expansion coefficients exhibit significant anisotropy and the influence of the magnetic ions and long-range order. A structural phase transition to orthorhombic occurs below T N for FeTa 2 O 6 . Magnetic field H lowers T N with its affect largest when H is directed along either [1 1 0] or [1 [Formula: see text] 0], and smallest when directed along [0 0 1]. This leads to an anisotropic magnetocaloric effect that is investigated through measurements of the specific heat and magnetization in applied magnetic field.

Timeline and bibliography of early isolations of plant metabolites (1770-1820) and their impact to pharmacy: A critical study.

PubMed

Drobnik, Jacek; Drobnik, Elżbieta

2016-10-27

Plant metabolites became objects of chemical research for pharmaceutical and medicinal reasons. The period of pure plant substances in chemistry started 1770 with isolation of tartaric acid from wine (wine in pharmacy is a plant-derived preparation). Carl Scheele isolated 7 plant acids: tartaric, benzoic, citric, oxalic, malic, glucuronic and gallic. The era of alkaloids started 1803 when narcotine was discovered and published. Since that time, pharmacists and toxicologists began to recognize alkaloids (or substances regarded as such) as highly active principles responsible for their powerful, thus easily-observed actions to humans and test animals. By 1820 when solanine was isolated, pharmaceutical chemistry has dealt with increasing number of natural plant-derived substances as organic medicines or reagents. The following historical facts have been unknown: Scheele's tartaric acid was introduced officially as a medicinal substance as early as in 1775, benzoic, citric and oxalic acids became official by the end of the 18th century. Morphine was effectively published in 1806 (not 1804), hence the first alkaloid known in isolated state is narcotine (published 1803, official since 1827). Morphine became official in French pharmacy in 1818. And, 1814 is the year when 2 first toxicological accounts on plant-derived acids (oxalic and tartaric) appeared. Practical use in therapy, sometimes soon after discovery, inspired practical pharmacy and stimulated the progress of toxicology. We studied the earliest 50years of plant metabolites isolations era. A revised bibliography and a timeline chart for 24 plant substances from this period is provided. Plants from original publications are taxonomically identified. Copyright © 2016 Elsevier B.V. All rights reserved.

Wheat Gene TaATG8j Contributes to Stripe Rust Resistance.

PubMed

Mamun, Md Abdullah-Al; Tang, Chunlei; Sun, Yingchao; Islam, Md Nazrul; Liu, Peng; Wang, Xiaojie; Kang, Zhensheng

2018-06-05

Autophagy-related 8 (ATG8) protein has been reported to be involved in plant's innate immune response, but it is not clear whether such genes play a similar role in cereal crops against obligate biotrophic fungal pathogens. Here, we reported an ATG8 gene from wheat ( Triticum aestivum ), designated TaATG8j . This gene has three copies located in chromosomes 2AS, 2BS, and 2DS. The transcriptions of all three copies were upregulated in plants of the wheat cultivar Suwon 11, inoculated with an avirulent race (CYR23) of Puccinia striiformis f. sp. tritici ( Pst ), the causal fungal pathogen of stripe rust. The transient expression of TaATG8j in Nicotiana benthamiana showed that TaATG8j proteins were distributed throughout the cytoplasm, but mainly in the nucleus and plasma membrane. The overexpression of TaATG8j in N. benthamiana slightly delayed the cell death caused by the mouse apoptotic protein BAX (BCL2-associated X protein). However, the expression of TaATG8j in yeast ( Schizosaccharomyces pombe ) induced cell death. The virus-induced gene silencing of all TaATG8j copies rendered Suwon 11 susceptible to the avirulent Pst race CYR23, accompanied by an increased fungal biomass and a decreased necrotic area per infection site. These results indicate that TaATG8j contributes to wheat resistance against stripe rust fungus by regulating cell death, providing information for the understanding of the mechanisms of wheat resistance to the stripe rust pathogen.

The effect of growth sequence on magnetization damping in Ta/CoFeB/MgO structures

NASA Astrophysics Data System (ADS)

Liu, Bo; Huang, Dawei; Gao, Ming; Tu, Hongqing; Wang, Kejie; Ruan, Xuezhong; Du, Jun; Cai, Jian-Wang; He, Liang; Wu, Jing; Wang, Xinran; Xu, Yongbing

2018-03-01

Magnetization damping is a key parameter to control the critical current and the switching speed in magnetic random access memory, and here we report the effect of the growth sequence on the magnetic dynamics properties of perpendicularly magnetized Ta/CoFeB/MgO structures. Ultrathin CoFeB films have been grown between Ta and MgO but with different stack sequences, i.e. substrate/Ta/CoFeB/MgO/Ta and substrate/Ta/MgO/CoFeB/Ta. The magnetization dynamics induced by femtosecond laser was investigated by using all-optical pump-probe measurements. We found that the Gilbert damping constant was modulated by reversing stack structures, which offers the potential to tune the damping parameter by the growth sequence. The Gilbert damping constant was enhanced from 0.017 for substrate/Ta/CoFeB/MgO/Ta to 0.027 for substrate/Ta/MgO/CoFeB/Ta. We believe that this enhancement originates from the increase of intermixing at the CoFeB/Ta when the Ta atom layer was grown after the CoFeB layer.

Platelet Adhesion and Activation on Chiral Surfaces: The Influence of Protein Adsorption.

PubMed

Fan, Yonghong; Luo, Rifang; Han, Honghong; Weng, Yajun; Wang, Hong; Li, Jing'an; Yang, Ping; Wang, Yunbing; Huang, Nan

2017-10-03

Adsorbed proteins and their conformational change on blood-contacting biomaterials will determine their final hemocompatibility. It has frequently been reported that surface chirality of biomaterials may highly influence their protein adsorption behavior. Here, lysine and tartaric acid with different chirality were immobilized onto TiO 2 films respectively, and the influence of surface chirality on protein adsorption, platelet adhesion, and activation was also investigated. It showed that the l- and d-molecule grafted samples had almost the same grafting density, surface topography, chemical components, and hydrophilicity in this study. However, biological behaviors such as protein adsorption, platelet adhesion, and activation were quite different. The d-lysine grafted surface had a greater ability to inhibit both bovine serum albumin and fibrinogen adsorption, along with less degeneration of fibrinogen compared to the l-lysine anchored surface. However, the d-tartaric acid grafted surface adsorbed more protein but with less denatured fibrinogen compared to the l-tartaric acid grafted one. Further studies showed that the secondary structural change of the adsorbed albumin and fibrinogen on all surfaces with deduction of the α-helix content and increase of disordered structure, while the changing degree was apparently varied. As a result, the d-lysine immobilized surface absorbed less platelets and red blood cells and achieved slightly increased platelet activation. For tartaric acid anchored surfaces, a larger number of platelets adhered to the D-surface but were less activated compared to the L-surface. In conclusion, the surface chirality significantly influenced the adsorption and conformational change of blood plasma protein, which in turn influenced both platelet adhesion and activation.

Love-type surface acoustic wave on Y-X LiTaO3 with amorphous Ta2O5 thin film

NASA Astrophysics Data System (ADS)

Kakio, Shoji; Fukasawa, Haruka; Hosaka, Keiko

2015-07-01

In this study, to obtain a substrate structure with a lower phase velocity, the propagation properties of a Love-type surface acoustic wave (Love SAW) on Y-X LiTaO3 (LT) with an amorphous tantalum pentoxide (a-Ta2O5) thin film were investigated using a simple delay line and a resonator with a wavelength λ of 8 µm. The insertion loss of a simple delay line was decreased markedly by loading with an a-Ta2O5 film owing to a transformation from a leaky SAW (LSAW) to a non-leaky Love SAW. A phase velocity of 3,340 m/s, a coupling factor of 5.8%, and a propagation loss of 0.03 dB/λ were obtained for a normalized thickness h/λ of 0.120. Moreover, the resonance properties of the Love SAW were almost equal or superior to those for an LSAW on Al/36° Y-X LT, except for the fractional bandwidth.

Effects of crystal structure and composition on the photocatalytic performance of Ta-O-N functional materials.

PubMed

Liu, Qing-Lu; Zhao, Zong-Yan; Yi, Jian-Hong

2018-05-07

For photocatalytic applications, the response of a material to the solar spectrum and its redox capabilities are two important factors determined by the band gap and band edge position of the electronic structure of the material. The crystal structure and composition of the photocatalyst are fundamental for determining the above factors. In this article, we examine the functional material Ta-O-N as an example of how to discuss relationships among these factors in detail with the use of theoretical calculations. To explore how the crystal structure and composition influence the photocatalytic performance, two groups of Ta-O-N materials were considered: the first group included ε-Ta 2 O 5 , TaON, and Ta 3 N 5 ; the second group included β-Ta 2 O 5 , δ-Ta 2 O 5 , ε-Ta 2 O 5 , and amorphous-Ta 2 O 5 . Calculation results indicated that the band gap and band edge position are determined by interactions between the atomic core and valence electrons, the overlap of valence electronic states, and the localization of valence states. Ta 3 N 5 and TaON are suitable candidates for efficient photocatalysts owing to their photocatalytic water-splitting ability and good utilization efficiency of solar energy. δ-Ta 2 O 5 has a strong oxidation potential and a band gap suitable for absorbing visible light. Thus, it can be applied to photocatalytic degradation of most pollutants. Although a-Ta 2 O 5 , ε-Ta 2 O 5 , and β-Ta 2 O 5 cannot be directly used as photocatalysts, they can still be applied to modify conventional Ta-O-N photocatalysts, owing to their similar composition and structure. These calculation results will be helpful as reference data for analyzing the photocatalytic performance of more complicated Ta-O-N functional materials. On the basis of these findings, one could design novel Ta-O-N functional materials for specific photocatalytic applications by tuning the composition and crystal structure.

Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat, Barley, Maize, and Rice[W][OA

PubMed Central

Dionisio, Giuseppe; Madsen, Claus K.; Holm, Preben B.; Welinder, Karen G.; Jørgensen, Malene; Stoger, Eva; Arcalis, Elsa; Brinch-Pedersen, Henrik

2011-01-01

Barley (Hordeum vulgare) and wheat (Triticum aestivum) possess significant phytase activity in the mature grains. Maize (Zea mays) and rice (Oryza sativa) possess little or virtually no preformed phytase activity in the mature grain and depend fully on de novo synthesis during germination. Here, it is demonstrated that wheat, barley, maize, and rice all possess purple acid phosphatase (PAP) genes that, expressed in Pichia pastoris, give fully functional phytases (PAPhys) with very similar enzyme kinetics. Preformed wheat PAPhy was localized to the protein crystalloid of the aleurone vacuole. Phylogenetic analyses indicated that PAPhys possess four conserved domains unique to the PAPhys. In barley and wheat, the PAPhy genes can be grouped as PAPhy_a or PAPhy_b isogenes (barley, HvPAPhy_a, HvPAPhy_b1, and HvPAPhy_b2; wheat, TaPAPhy_a1, TaPAPhy_a2, TaPAPhy_b1, and TaPAPhy_b2). In rice and maize, only the b type (OsPAPhy_b and ZmPAPhy_b, respectively) were identified. HvPAPhy_a and HvPAPhy_b1/b2 share 86% and TaPAPhya1/a2 and TaPAPhyb1/b2 share up to 90% (TaPAPhy_a2 and TaPAPhy_b2) identical amino acid sequences. despite of this, PAPhy_a and PAPhy_b isogenes are differentially expressed during grain development and germination. In wheat, it was demonstrated that a and b isogene expression is driven by different promoters (approximately 31% identity). TaPAPhy_a/b promoter reporter gene expression in transgenic grains and peptide mapping of TaPAPhy purified from wheat bran and germinating grains confirmed that the PAPhy_a isogene set present in wheat/barley but not in rice/maize is the origin of high phytase activity in mature grains. PMID:21220762

Use of tranexamic acid in primary total knee replacement: effects on perioperative blood loss.

PubMed

Volquind, Daniel; Zardo, Remi Antônio; Winkler, Bruno Costamilan; Londero, Bruno Bertagnolli; Zanelatto, Natália; Leichtweis, Gisele Perondi

2016-01-01

The use of tranexamic acid in primary total knee replacement surgeries has been the subject of constant study. The strategies to reduce bleeding are aimed at reducing the need for blood transfusion due to the risks involved. In this study we evaluated the use of tranexamic acid in reducing bleeding, need for blood transfusion, and prevalence of postoperative deep vein thrombosis in primary total knee replacement. 62 patients undergoing primary total knee replacement were enrolled in the study, from June 2012 to May 2013, and randomized to receive a single dose of 2.5g of intravenous tranexamic acid (Group TA) or saline (Group GP), 5min before opening the pneumatic tourniquet, respectively. Hemoglobin, hematocrit, and blood loss were recorded 24h after surgery. Deep vein thrombosis was investigated during patient's hospitalization and 15 and 30 days after surgery in review visits. There was no demographic difference between groups. Group TA had 13.89% decreased hematocrit (p=0.925) compared to placebo. Group TA had a decrease of 12.28% (p=0.898) in hemoglobin compared to Group GP. Group TA had a mean decrease of 187.35mL in blood loss (25.32%) compared to group GP (p=0.027). The number of blood transfusions was higher in Group GP (p=0.078). Thromboembolic events were not seen in this study. Tranexamic acid reduced postoperative bleeding without promoting thromboembolic events. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Model of the synthesis of trisporic acid in Mucorales showing bistability.

PubMed

Werner, S; Schroeter, A; Schimek, C; Vlaic, S; Wöstemeyer, J; Schuster, S

2012-12-01

An important substance in the signalling between individuals of Mucor-like fungi is trisporic acid (TA). This compound, together with some of its precursors, serves as a pheromone in mating between (+)- and (-)-mating types. Moreover, intermediates of the TA pathway are exchanged between the two mating partners. Based on differential equations, mathematical models of the synthesis pathways of TA in the two mating types of an idealised Mucor-fungus are here presented. These models include the positive feedback of TA on its own synthesis. The authors compare three sub-models in view of bistability, robustness and the reversibility of transitions. The proposed modelling study showed that, in a system where intermediates are exchanged, a reversible transition between the two stable steady states occurs, whereas an exchange of the end product leads to an irreversible transition. The reversible transition is physiologically favoured, because the high-production state of TA must come to an end eventually. Moreover, the exchange of intermediates and TA is compared with the 3-way handshake widely used by computers linked in a network.

Fragment distribution in 78,86Kr+181Ta reactions

NASA Astrophysics Data System (ADS)

Zhang, Dong-Hong; Zhang, Feng-Shou

2018-05-01

Within the framework of the isospin-dependent quantum molecular dynamics model, along with the GEMINI model, the 86Kr+181Ta reaction at 80, 120 and 160 MeV/nucleon and the 78Kr+181Ta reaction at 160 MeV/nucleon are studied, and the production cross sections of the generated fragments are calculated. More inter-mediate and large mass fragments can be produced in the reactions with a large range of impact parameter. The production cross sections of nuclei such as the isotopes of Si and P generally decrease with increasing incident energy. Isotopes near the neutron drip line are produced more in the neutron-rich system 86Kr+181Ta. Supported by Youth Research Foundation of Shanxi Datong University (2016Q10)

Tandem Core–Shell Si–Ta 3N 5 Photoanodes for Photoelectrochemical Water Splitting

DOE PAGES

Narkeviciute, Ieva; Chakthranont, Pongkarn; Mackus, Adriaan J. M.; ...

2016-11-22

Here, nanostructured core–shell Si–Ta 3N 5 photoanodes were designed and synthesized to overcome charge transport limitations of Ta 3N 5 for photoelectrochemical water splitting. The core–shell devices were fabricated by atomic layer deposition of amorphous Ta 2O 5 onto nanostructured Si and subsequent nitridation to crystalline Ta 3N 5. Nanostructuring with a thin shell of Ta 3N 5 results in a 10-fold improvement in photocurrent compared to a planar device of the same thickness. In examining thickness dependence of the Ta 3N 5 shell from 10 to 70 nm, superior photocurrent and absorbed-photon-to-current efficiencies are obtained from the thinner Tamore » 3N 5 shells, indicating minority carrier diffusion lengths on the order of tens of nanometers. The fabrication of a heterostructure based on a semiconducting, n-type Si core produced a tandem photoanode with a photocurrent onset shifted to lower potentials by 200 mV. CoTiO x and NiO x water oxidation cocatalysts were deposited onto the Si–Ta 3N 5 to yield active photoanodes that with NiO x retained 50–60% of their maximum photocurrent after 24 h chronoamperometry experiments and are thus among the most stable Ta 3N 5 photoanodes reported to date.« less

Preparation of reference material for UGT1A1 (TA)n polymorphism genotyping.

PubMed

Mlakar, Vid; Mlakar, Simona Jurković; Marc, Janja; Ostanek, Barbara

2014-08-05

Gilbert's syndrome is one of the most common metabolic syndromes in the human population characterised by mild unconjugated hyperbilirubinemia resulting from reduced activity of the bilirubin conjugating enzyme UDP-glucuronosyltransferase (UGT1A1). Although Gilbert's syndrome is usually quite benign UGT1A1(TA)n genotyping is important in exclusion of more serious causes of hyperbilirubinemia and since it has significant implications for personalised medicine. The aim of our study was to develop plasmid based reference materials which could be used for UGT1A1(TA)n genotyping. Plasmids were generated using recombinant DNA technology and their number of repeats as well as the entire sequence verified by Sanger sequencing. Their suitability as reference materials was tested using sizing by capillary electrophoresis and denaturing high performance liquid chromatography. Plasmids containing all four different alleles (TA)5, (TA)6, (TA)7 and (TA)8 that are present in the human population as well as a plasmid with (TA)4 repeats were successfully generated. Prepared plasmid reference materials allow the creation of all possible UGT1A1(TA)n polymorphism genotypes and can serve as an efficient substitute for the human genomic DNA reference material in routine genotyping and in the development of new genotyping tests. Copyright © 2014 Elsevier B.V. All rights reserved.

Suboxide/subnitride formation on Ta masks during magnetic material etching by reactive plasmas

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

Li, Hu; Muraki, Yu; Karahashi, Kazuhiro

2015-07-15

Etching characteristics of tantalum (Ta) masks used in magnetoresistive random-access memory etching processes by carbon monoxide and ammonium (CO/NH{sub 3}) or methanol (CH{sub 3}OH) plasmas have been examined by mass-selected ion beam experiments with in-situ surface analyses. It has been suggested in earlier studies that etching of magnetic materials, i.e., Fe, Ni, Co, and their alloys, by such plasmas is mostly due to physical sputtering and etch selectivity of the process arises from etch resistance (i.e., low-sputtering yield) of the hard mask materials such as Ta. In this study, it is shown that, during Ta etching by energetic CO{sup +}more » or N{sup +} ions, suboxides or subnitrides are formed on the Ta surface, which reduces the apparent sputtering yield of Ta. It is also shown that the sputtering yield of Ta by energetic CO{sup +} or N{sup +} ions has a strong dependence on the angle of ion incidence, which suggests a correlation between the sputtering yield and the oxidation states of Ta in the suboxide or subnitride; the higher the oxidation state of Ta, the lower is the sputtering yield. These data account for the observed etch selectivity by CO/NH{sub 3} and CH{sub 3}OH plasmas.« less

TaGW2, a Good Reflection of Wheat Polyploidization and Evolution

PubMed Central

Qin, Lin; Zhao, Junjie; Li, Tian; Hou, Jian; Zhang, Xueyong; Hao, Chenyang

2017-01-01

Hexaploid wheat consists of three subgenomes, namely, A, B, and D. These well-characterized ancestral genomes also exist at the diploid and tetraploid levels, thereby rendering wheat as a good model species for studying polyploidization. Here, we performed intra- and inter-species comparative analyses of wheat and its relatives to dissect polymorphism and differentiation of the TaGW2 genes. Our results showed that genetic diversity of TaGW2 decreased with progression from the diploids to tetraploids and hexaploids. The strongest selection occurred in the promoter regions of TaGW2-6A and TaGW2-6B. Phylogenetic trees clearly indicated that Triticum urartu and Ae. speltoides were the donors of the A and B genomes in tetraploid and hexaploid wheats. Haplotypes detected among hexaploid genotypes traced back to the tetraploid level. Fst and π values revealed that the strongest selection on TaGW2 occurred at the tetraploid level rather than in hexaploid wheat. This infers that grain size enlargement, especially increased kernel width, mainly occurred in tetraploid genotypes. In addition, relative expression levels of TaGW2s significantly declined from the diploid level to tetraploids and hexaploids, further indicating that these genes negatively regulate kernel size. Our results also revealed that the polyploidization events possibly caused much stronger differentiation than domestication and breeding. PMID:28326096

TaGW2, a Good Reflection of Wheat Polyploidization and Evolution.

PubMed

Qin, Lin; Zhao, Junjie; Li, Tian; Hou, Jian; Zhang, Xueyong; Hao, Chenyang

2017-01-01

Hexaploid wheat consists of three subgenomes, namely, A, B, and D. These well-characterized ancestral genomes also exist at the diploid and tetraploid levels, thereby rendering wheat as a good model species for studying polyploidization. Here, we performed intra- and inter-species comparative analyses of wheat and its relatives to dissect polymorphism and differentiation of the TaGW2 genes. Our results showed that genetic diversity of TaGW2 decreased with progression from the diploids to tetraploids and hexaploids. The strongest selection occurred in the promoter regions of TaGW2-6A and TaGW2-6B . Phylogenetic trees clearly indicated that Triticum urartu and Ae. speltoides were the donors of the A and B genomes in tetraploid and hexaploid wheats. Haplotypes detected among hexaploid genotypes traced back to the tetraploid level. Fst and π values revealed that the strongest selection on TaGW2 occurred at the tetraploid level rather than in hexaploid wheat. This infers that grain size enlargement, especially increased kernel width, mainly occurred in tetraploid genotypes. In addition, relative expression levels of TaGW2s significantly declined from the diploid level to tetraploids and hexaploids, further indicating that these genes negatively regulate kernel size. Our results also revealed that the polyploidization events possibly caused much stronger differentiation than domestication and breeding.

Efficacy and possible mechanisms of topical tranexamic acid in melasma.

PubMed

Kim, S J; Park, J-Y; Shibata, T; Fujiwara, R; Kang, H Y

2016-07-01

Tranexamic acid (TA) has been suggested as an effective treatment for melasma. To investigate the effects and mechanism of action of topical TA in the treatment of melasma. In this study, 23 participants with melasma applied a 2% TA formulation to the whole face for 12 weeks. Clinical effects were evaluated using the modified Melasma Area and Severity Index (mMASI) and a chromameter. Skin biopsies were obtained from 10 participants to evaluate pigmentation, vascularity and the expression levels of possible paracrine factors contributing to the effect of TA. Most of the participants had mild melasma, with mMASI of < 5. The mMASI scores significantly improved in 22 of 23 participants after application. The L* values were increased and the a* values were decreased in both lesional and perilesional normal skin. Fontana-Masson staining showed a significant decrease in melanin content in the epidermis. The number of CD31-positive vessels and the expression of the vascular endothelial growth factor both tended to decrease. Endothelin (ET)-1 was found to be downregulated with TA. Topical TA is effective for melasma. This immunohistochemical study found that suppression of ET-1 could be one of the mechanisms of action of TA on melasma. © 2016 British Association of Dermatologists.

Combination of 13 cis-retinoic acid and tolfenamic acid induces apoptosis and effectively inhibits high-risk neuroblastoma cell proliferation.

PubMed

Shelake, Sagar; Eslin, Don; Sutphin, Robert M; Sankpal, Umesh T; Wadwani, Anmol; Kenyon, Laura E; Tabor-Simecka, Leslie; Bowman, W Paul; Vishwanatha, Jamboor K; Basha, Riyaz

2015-11-01

Chemotherapeutic regimens used for the treatment of Neuroblastoma (NB) cause long-term side effects in pediatric patients. NB arises in immature sympathetic nerve cells and primarily affects infants and children. A high rate of relapse in high-risk neuroblastoma (HRNB) necessitates the development of alternative strategies for effective treatment. This study investigated the efficacy of a small molecule, tolfenamic acid (TA), for enhancing the anti-proliferative effect of 13 cis-retinoic acid (RA) in HRNB cell lines. LA1-55n and SH-SY5Y cells were treated with TA (30μM) or RA (20μM) or both (optimized doses, derived from dose curves) for 48h and tested the effect on cell viability, apoptosis and selected molecular markers (Sp1, survivin, AKT and ERK1/2). Cell viability and caspase activity were measured using the CellTiter-Glo and Caspase-Glo kits. The apoptotic cell population was determined by flow cytometry with Annexin-V staining. The expression of Sp1, survivin, AKT, ERK1/2 and c-PARP was evaluated by Western blots. The combination therapy of TA and RA resulted in significant inhibition of cell viability (p<0.0001) when compared to individual agents. The anti-proliferative effect is accompanied by a decrease in Sp1 and survivin expression and an increase in apoptotic markers, Annexin-V positive cells, caspase 3/7 activity and c-PARP levels. Notably, TA+RA combination also caused down regulation of AKT and ERK1/2 suggesting a distinct impact on survival and proliferation pathways via signaling cascades. This study demonstrates that the TA mediated inhibition of Sp1 in combination with RA provides a novel therapeutic strategy for the effective treatment of HRNB in children. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization and Modeling of Nonfilamentary Ta/TaOx/TiO2/Ti Analog Synaptic Device

PubMed Central

Wang, Yu-Fen; Lin, Yen-Chuan; Wang, I-Ting; Lin, Tzu-Ping; Hou, Tuo-Hung

2015-01-01

A two-terminal analog synaptic device that precisely emulates biological synaptic features is expected to be a critical component for future hardware-based neuromorphic computing. Typical synaptic devices based on filamentary resistive switching face severe limitations on the implementation of concurrent inhibitory and excitatory synapses with low conductance and state fluctuation. For overcoming these limitations, we propose a Ta/TaOx/TiO2/Ti device with superior analog synaptic features. A physical simulation based on the homogeneous (nonfilamentary) barrier modulation induced by oxygen ion migration accurately reproduces various DC and AC evolutions of synaptic states, including the spike-timing-dependent plasticity and paired-pulse facilitation. Furthermore, a physics-based compact model for facilitating circuit-level design is proposed on the basis of the general definition of memristor devices. This comprehensive experimental and theoretical study of the promising electronic synapse can facilitate realizing large-scale neuromorphic systems. PMID:25955658

Genetic variation of an acid phosphatase (Acp-2) in the laboratory rat: possible homology with mouse AP-1 and human ACP2.

PubMed

Bender, K; Bissbort, S; Kuhn, A; Nagel, M; Günther, E

1986-02-01

A genetic locus controlling the electrophoretic mobility of an acid phosphatase in the rat (Rattus norvegicus) is described. The locus, designed Acp-2, is not expressed in erythrocytes but is expressed in all other tissues studied. The product of Acp-2 hydrolyzes a wide variety of phosphate monoesters and is inhibited by L(+)-tartaric acid. Inbred rat strains have fixed either allele Acp-2a or allele Acp-2b. Codominant expression is observed in the respective F1 hybrids. Backcross progenies revealed the expected 1:1 segregation ratio. Possible loose linkage was found between the Acp-2 and the Pep-3 gene loci at a recombination frequency of 0.36 +/- 0.06.

Structure of screw dislocation core in Ta at high pressure

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

Wang, Shaofeng, E-mail: sfwang@cqu.edu.cn; Jiang, Na; Wang, Rui

2014-03-07

The core structure and Peierls stress of the 1/2 〈111〉(110) screw dislocation in Ta have been investigated theoretically using the modified Peierls–Nabarro theory that takes into account the discreteness effect of crystal. The lattice constants, the elastic properties, and the generalized-stacking-fault energy(γ-surface) under the different pressures have been calculated from the electron density functional theory. The core structure of dislocation is determined by the modified Peierls equation, and the Peierls stress is evaluated from the dislocation energy that varies periodically as dislocation moves. The results show the core width and Peierls stress in Ta are weakly dependent of the pressuremore » up to 100 GPa when the length and stress are measured separately by the Burgers vector b and shear modulus μ. This indicates that core structure is approximately scaling invariant for the screw dislocation in Ta. The scaled plasticity of Ta changes little in high pressure environment.« less

A wheat salinity-induced WRKY transcription factor TaWRKY93 confers multiple abiotic stress tolerance in Arabidopsis thaliana.

PubMed

Qin, Yuxiang; Tian, Yanchen; Liu, Xiuzhi

2015-08-21

Wheat is an important crop in the world. But most of the cultivars are salt sensitive, and often adversely affected by salt stress. WRKY transcription factors play a major role in plant responses to salt stress, but the effective salinity regulatory WRKYs identified in bread wheat are limited and the mechanism of salt stress tolerance is also not well explored. Here, we identified a salt (NaCl) induced class II WRKY transcription factor TaWRKY93. Its transcript level was strongly induced by salt (NaCl) and exogenous abscisic acid (ABA). Over-expression of TaWRKY93 in Arabidopsis thaliana enhanced salt (NaCl), drought, low temperature and osmotic (mannitol) stress tolerance, mainly demonstrated by transgenic plants forming longer primary roots or more lateral roots on MS plates supplemented with NaCl and mannitol individually, higher survival rate under drought and low temperature stress. Further, transgenic plants maintained a more proline content, higher relative water content and less electrolyte leakage than the wild type plants. The transcript abundance of a series of abiotic stress-related genes was up-regulated in the TaWRKY93 transgenic plants. In summary, TaWRKY93 is a new positive regulator of abiotic stress, it may increase salinity, drought and low temperature stress tolerance through enhancing osmotic adjustment, maintaining membrane stability and increasing transcription of stress related genes, and contribute to the superior agricultural traits of SR3 through promoting root development. It can be used as a candidate gene for wheat transgenic engineering breeding against abiotic stress. Copyright © 2015 Elsevier Inc. All rights reserved.

Molecular cloning of TA16, a transcriptional repressor that may mediate glucocorticoid-induced growth arrest of leiomyosarcoma cells.

PubMed

Fan, W; Ma, J X; Cheng, L; Norris, J S

1997-08-01

The DDT1 MF2 smooth muscle tumor cell line was derived from an estrogen/androgen-induced leiomyosarcoma that arose in the ductus deferens of a Syrian hamster. The growth of this cell line is arrested at the G0/G1 phase of the cell cycle after treatment with glucocorticoids. To identify the putative gene(s) that are potentially involved in this hormone-induced cell growth arrest, we have used a differential screening technique to clone those genes whose expression is induced or up-regulated by glucocorticoids. A number of glucocorticoid response genes were thereby isolated from the leiomyosarcoma cells. One of these clones, termed TA16, was found to be markedly up-regulated by glucocorticoids in DDT1 MF2 cells, but only marginally changed in GR1 cells, a glucocorticoid-resistant variant that was selected from the wild type DDT1 MF2 cell. Isolation and sequencing of its intact cDNA indicated that the TA16 encodes a protein 485 amino acids long, and its sequence is closely homologous to a novel transcriptional repressor that presumably represses the transcription activity of some zinc finger transcriptional factors through a direct interaction. Transfection assays demonstrated that introduction of an antisense TA16 cDNA expression vector, controlled by an MMTV promoter, into the DDT1 MF2 cell significantly relieved the glucocorticoid-induced cell growth arrest. This finding suggests that TA16 might participate in the mediation of glucocorticoid-induced cell cycle arrest in leiomyosarcoma cells.

[Nutrition, acid-base metabolism, cation-anion difference and total base balance in humans].

PubMed

Mioni, R; Sala, P; Mioni, G

2008-01-01

The relationship between dietary intake and acid-base metabolism has been investigated in the past by means of the inorganic cation-anion difference (C(+)(nm)-A(-)(nm)) method based on dietary ash-acidity titration after the oxidative combustion of food samples. Besides the inorganic components of TA (A(-)(nm)-C(+)(nm)), which are under renal control, there are also metabolizable components (A(-)(nm)-C(+)(nm)) of TA, which are under the control of the intermediate metabolism. The whole body base balance, NBb(W), is obtained only by the application of C(+)(nm)-A(-)(nm) to food, feces and urine, while the metabolizable component (A(-)(nm)-C(+)(nm)) is disregarded. A novel method has been subsequently suggested to calculate the net balance of fixed acid, made up by the difference between the input of net endogenous acid production: NEAP = SO(4)(2-)+A(-)(m)-(C(+)(nm)-A(-)(nm)), and the output of net acid excretion: NAE = TA + NH(4)(+) - HCO(3)(-). This approach has been criticized because 1) it includes metabolizable acids, whose production cannot be measured independently; 2) the specific control of metabolizable acid and base has been incorrectly attributed to the kidney; 3) the inclusion of A-m in the balance input generates an acid overload; 4) the object of measurement in making up a balance has to be the same, a condition not fulfilled as NEAP is different from NAE. Lastly, by rearranging the net balance of the acid equation, the balance of nonmetabolizable acid equation is obtained. Therefore, any discrepancy between these two equations is due to the inaccuracy in the urine measurement of metabolizable cations and/or anions.

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

Fu, Jiayi; Vasiliadou, Efterpi S.; Goulas, Konstantinos A.

A novel one-step process for the selective production of succinic acid from tartaric acid is developed. High succinic yield is achieved in an efficient catalytic system comprised of MoO x/BC, HBr and acetic acid under hydrogen atmosphere.

Identification of 9α-Hydroxy-17-Oxo-1,2,3,4,10,19-Hexanorandrostan-5-Oic Acid in Steroid Degradation by Comamonas testosteroni TA441 and Its Conversion to the Corresponding 6-En-5-Oyl Coenzyme A (CoA) Involving Open Reading Frame 28 (ORF28)- and ORF30-Encoded Acyl-CoA Dehydrogenases

PubMed Central

Hayashi, Toshiaki; Koshino, Hiroyuki; Malon, Michal; Hirota, Hiroshi; Kudo, Toshiaki

2014-01-01

Comamonas testosteroni TA441 degrades steroids via aromatization and meta-cleavage of the A ring, followed by hydrolysis, and produces 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid as an intermediate compound. Herein, we identify a new intermediate compound, 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid. Open reading frame 28 (ORF28)- and ORF30-encoded acyl coenzyme A (acyl-CoA) dehydrogenase was shown to convert the CoA ester of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid to the CoA ester of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrost-6-en-5-oic acid. A homology search of the deduced amino acid sequences suggested that the ORF30-encoded protein is a member of the acyl-CoA dehydrogenase_fadE6_17_26 family, whereas the deduced amino acid sequence of ORF28 showed no significant similarity to specific acyl-CoA dehydrogenase family proteins. Possible steroid degradation gene clusters similar to the cluster of TA441 appear in bacterial genome analysis data. In these clusters, ORFs similar to ORFs 28 and 30 are often found side by side and ordered in the same manner as ORFs 28 and 30. PMID:25092028

21 CFR 150.141 - Artificially sweetened fruit jelly.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably compensates for... in paragraph (c) of this section, with a jelling ingredient as specified in paragraph (d) of this...

21 CFR 150.141 - Artificially sweetened fruit jelly.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably compensates for... in paragraph (c) of this section, with a jelling ingredient as specified in paragraph (d) of this...

21 CFR 150.141 - Artificially sweetened fruit jelly.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably compensates for... in paragraph (c) of this section, with a jelling ingredient as specified in paragraph (d) of this...

21 CFR 150.141 - Artificially sweetened fruit jelly.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably compensates for... in paragraph (c) of this section, with a jelling ingredient as specified in paragraph (d) of this...

Superconducting order from disorder in 2H-TaSe2-xSx

NASA Astrophysics Data System (ADS)

Li, Lijun; Deng, Xiaoyu; Wang, Zhen; Liu, Yu; Abeykoon, Milinda; Dooryhee, Eric; Tomic, Aleksandra; Huang, Yanan; Warren, John B.; Bozin, Emil S.; Billinge, Simon J. L.; Sun, Yuping; Zhu, Yimei; Kotliar, Gabriel; Petrovic, Cedomir

2017-12-01

We report on the emergence of robust superconducting order in single crystal alloys of TaSe2-xSx (0 ≤ × ≤ 2). The critical temperature of the alloy is surprisingly higher than that of the two end compounds TaSe2 and TaS2. The evolution of superconducting critical temperature Tc(x) correlates with the full width at half maximum of the Bragg peaks and with the linear term of the high-temperature resistivity. The conductivity of the crystals near the middle of the alloy series is higher or similar than that of either one of the end members 2H-TaSe2 and/or 2H-TaS2. It is known that in these materials superconductivity is in close competition with charge density wave order. We interpret our experimental findings in a picture where disorder tilts this balance in favor of superconductivity by destroying the charge density wave order.

D-erythroascorbic acid: Its preparations, chemistry, and metabolism (fungi and plants). Final report

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

Loewus, F.A.; Seib, P.A.

1991-12-31

The origin of oxalate in plants has received considerable attention and glycolate metabolism has been generally regarded as a prime precursor candidate although studies on the metabolism of L-ascorbic acid single out that plant constituent as well. Experiments with oxalate-accumulating plants that contain little or no tartaric acid revealed the presence of a comparable L-ascorbic acid metabolism with the exception that the cleavage products were oxalic acid and L-threonic acid or products of L-threonic acid metabolism. A reasonable mechanism for cleavage of L-ascorbic acid at the endiolic bond is found in studies on the photooxygenation of L-ascorbic acid. Presumably, analogsmore » of L-ascorbic acid that differ only in the substituent at C4 also form a hydroperoxide in the presence of alkaline hydrogen peroxide and subsequently yield oxalic acid and the corresponding aldonic acid or its lactone. We became interested in such a possibility when we discovered that L-ascorbic acid was rare or absent in certain yeasts and fungi whereas a L-ascorbic acid analog, D-glycero-pent-2-enono- 1,4-lactone (D-erythroascorbic acid), was present. It has long been known that oxalate occurs in yeasts and fungi and its production plays a role in plant pathogenesis. As to the biosynthetic origin of fungal oxalic acid there is little information although it is generally assumed that oxaloacetate or possibly, glycolate, might be that precursor.« less

SEMICONDUCTOR TECHNOLOGY: TaN wet etch for application in dual-metal-gate integration technology

NASA Astrophysics Data System (ADS)

Yongliang, Li; Qiuxia, Xu

2009-12-01

Wet-etch etchants and the TaN film method for dual-metal-gate integration are investigated. Both HF/HN O3/H2O and NH4OH/H2O2 solutions can etch TaN effectively, but poor selectivity to the gate dielectric for the HF/HNO3/H2O solution due to HF being included in HF/HNO3/H2O, and the fact that TaN is difficult to etch in the NH4OH/H2O2 solution at the first stage due to the thin TaOxNy layer on the TaN surface, mean that they are difficult to individually apply to dual-metal-gate integration. A two-step wet etching strategy using the HF/HNO3/H2O solution first and the NH4OH/H2O2 solution later can fully remove thin TaN film with a photo-resist mask and has high selectivity to the HfSiON dielectric film underneath. High-k dielectric film surfaces are smooth after wet etching of the TaN metal gate and MOSCAPs show well-behaved C-V and Jg-Vg characteristics, which all prove that the wet etching of TaN has little impact on electrical performance and can be applied to dual-metal-gate integration technology for removing the first TaN metal gate in the PMOS region.

A natural antioxidant, tannic acid mitigates iron-overload induced hepatotoxicity in Swiss albino mice through ROS regulation.

PubMed

Basu, Tapasree; Panja, Sourav; Shendge, Anil Khushalrao; Das, Abhishek; Mandal, Nripendranath

2018-05-01

Tannic acid (TA), a water soluble natural polyphenol with 8 gallic acids groups, is abundantly present in various medicinal plants. Previously TA has been investigated for its antimicrobial and antifungal properties. Being a large polyphenol, TA chelates more than 1 metal. Hence TA has been explored for potent antioxidant activities against reactive oxygen species (ROS), reactive nitrogen species (RNS) and as iron chelator in vitro thereby mitigating iron-overload induced hepatotoxicity in vivo. Iron dextran was injected intraperitoneally in Swiss albino mice to induce iron-overload triggered hepatotoxicity, followed by oral administration of TA for remediation. After treatment, liver, spleen, and blood samples were processed from sacrificed animals. The liver iron, serum ferritin, serum markers, ROS, liver antioxidant status, and liver damage parameters were assessed, followed by histopathology and protein expression studies. Our results show that TA is a prominent ROS and RNS scavenger as well as iron chelator in vitro. It also reversed the ROS levels in vivo and restricted the liver damage parameters as compared to the standard drug, desirox. Moreover, this natural polyphenol exclusively ameliorates the histopathological and fibrotic changes in liver sections reducing the iron-overload, along with chelation of liver iron and normalization of serum ferritin. The protective role of TA against iron-overload induced apoptosis in liver was further supported by changed levels of caspase 3, PARP as well as Bax/BCl-2 ratio. Thus, TA can be envisaged as a better orally administrable iron chelator to reduce iron-overload induced hepatotoxicity through ROS regulation. © 2018 Wiley Periodicals, Inc.

Interface structure in Cu/Ta2O5/Pt resistance switch: a first-principles study.

PubMed

Xiao, Bo; Watanabe, Satoshi

2015-01-14

The interface structures of a Cu/Ta2O5/Pt resistance switch under various oxidation conditions have been examined from first-principles. The O-rich Cu/Ta2O5 interface is found to be stable within a wide range of O chemical potentials. In this interface structure, a considerable number of interface Cu atoms tend to migrate to the amorphous Ta2O5 (a-Ta2O5) layer, which causes the formation of the Cu2O layer. The interface Cu atoms become more ionized with an increase in the interface O concentration and/or temperature. These ionized Cu(+) ions could function as one of the main sources for the formation of conduction filaments in the Cu/a-Ta2O5/Pt resistance switch. In contrast, the ionization of the interface Cu atoms is not observed in the Cu/crystal-Ta2O5 interface primarily due to the much lower Cu ionic conductivity in crystal-Ta2O5 than that in amorphous state. In addition, the Pt electrode could not be ionized, irrespective of the interface O concentration and temperature. The formation of interface O vacancies in Pt/Ta2O5 is always energetically more stable than that in Cu/Ta2O5, which may be partly responsible for the cone shape of conduction filament formed in the Cu/a-Ta2O5/Pt resistance switch, where the base of the cone lies on the Pt/Ta2O5 interface.

Chromatin modification contributes to the expression divergence of three TaGS2 homoeologs in hexaploid wheat

PubMed Central

Zhang, Wei; Fan, Xiaoli; Gao, Yingjie; Liu, Lei; Sun, Lijing; Su, Qiannan; Han, Jie; Zhang, Na; Cui, Fa; Ji, Jun; Tong, Yiping; Li, Junming

2017-01-01

Plastic glutamine synthetase (GS2) is responsible for ammonium assimilation. The reason that TaGS2 homoeologs in hexaploid wheat experience different selection pressures in the breeding process remains unclear. TaGS2 were minimally expressed in roots but predominantly expressed in leaves, and TaGS2-B had higher expression than TaGS2-A and TaGS2-D. ChIP assays revealed that the activation of TaGS2-B expression in leaves was correlated with increased H3K4 trimethylation. The transcriptional silencing of TaGS2 in roots was correlated with greater cytosine methylation and less H3K4 trimethylation. Micrococcal nuclease and DNase I accessibility experiments indicated that the promoter region was more resistant to digestion in roots than leaves, which indicated that the closed nucleosome conformation of the promoter region was important to the transcription initiation for the spatial-temporal expression of TaGS2. In contrast, the transcribed regions possess different nuclease accessibilities of three TaGS2 homoeologs in the same tissue, suggesting that nucleosome conformation of the transcribed region was part of the fine adjustment of TaGS2 homoeologs. This study provides evidence that histone modification, DNA methylation and nuclease accessibility coordinated the control of the transcription of TaGS2 homoeologs. Our results provided important evidence that TaGS2-B experienced the strongest selection pressures during the breeding process. PMID:28300215

Interfacial Microstructure and Mechanical Strength of 93W/Ta Diffusion-Bonded Joints with Ni Interlayer

NASA Astrophysics Data System (ADS)

Luo, Guoqiang; Zhang, Jian; Li, Meijuan; Wei, Qinqin; Shen, Qiang; Zhang, Lianmeng

2013-02-01

93W alloy and Ta metal were successfully diffusion bonded using a Ni interlayer. Ni4W was found at the W-Ni interface, and Ni3Ta and Ni2Ta were formed at the Ni-Ta interface. The shear strength of the joints increases with increasing holding time, reaching a value of 202 MPa for a joint prepared using a 90-minute holding time at 1103 K (830 °C) and 20 MPa. The fracture of this joint occurred within the Ni/Ta interface.

Chemical sporulation and germination: cytoprotective nanocoating of individual mammalian cells with a degradable tannic acid-FeIII complex

NASA Astrophysics Data System (ADS)

Lee, Juno; Cho, Hyeoncheol; Choi, Jinsu; Kim, Doyeon; Hong, Daewha; Park, Ji Hun; Yang, Sung Ho; Choi, Insung S.

2015-11-01

Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-FeIII nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradation of the TA-FeIII nanocoat, mimicking the sporulation and germination processes found in nature.Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-FeIII nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradation of the TA-FeIII nanocoat, mimicking the sporulation and germination processes found in nature. Electronic supplementary information (ESI) available: Experimental details, LSCM images, and SEM and TEM images. See DOI: 10.1039/c5nr05573c

21 CFR 150.161 - Artificially sweetened fruit preserves and jams.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., spice extract. (2) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably... without water and a jelling ingredient as specified in paragraph (d) of this section. The quantity of the...

21 CFR 150.161 - Artificially sweetened fruit preserves and jams.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., spice extract. (2) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably... without water and a jelling ingredient as specified in paragraph (d) of this section. The quantity of the...

21 CFR 150.161 - Artificially sweetened fruit preserves and jams.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., spice extract. (2) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably... without water and a jelling ingredient as specified in paragraph (d) of this section. The quantity of the...

21 CFR 150.161 - Artificially sweetened fruit preserves and jams.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., spice extract. (2) A vinegar, lemon juice, lime juice, citric acid, lactic acid, malic acid, tartaric acid, fumaric acid, or any combination of two or more of these, in a quantity which reasonably... without water and a jelling ingredient as specified in paragraph (d) of this section. The quantity of the...

Local indigenous fruit-derived juices as alternate source of acidity regulators.

PubMed

D'souza, Cassandra; Fernandes, Rosaline; Kudale, Subhash; Naik, Azza Silotry

2018-03-01

Acidity regulators are additives that alter and control food acidity. The objective of this study was to explore local indigenous fruits as sources of natural acidity regulators. Juices extracted from Garcinia indica (kokum), Embilica officinalis (amla) and Tamarindus indica (tamarind) were used as acidulants for media such as coconut milk and bottle gourd juice. The buffering capacity β, acid composition, antioxidant activity and shelf-life study of the acidified media were estimated. Potentiometric titration showed G. indica to possess the highest buffering capacity in both ranges. High-performance liquid chromatography analysis showed T. indica contained a high level of tartaric acid (4.84 ± 0.01 mg g -1 ), while G. indica had citric acid (22.37 ± 0.84 mg g -1 ) and E. officinalis had citric acid (2.75 ± 0.02 mg g -1 ) along with ascorbic acid (2.68 ± 0.01 mg g -1 ). 1,1-Diphenyl-2-picrylhydrazyl scavenging activity was high for E. officinalis (91.24 ± 0.66%) and T. indica (90.93 ± 0.817%) and relatively lower for G. indica (34.61 ± 3.66%). The shelf-life study showed total plate count to be within the prescribed limits up to a week, in accordance with safety regulations. This investigation confirmed the suitability of indigenous fruit juices as alternatives to existing acidity regulators. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Oxidation of TaSi2-Containing ZrB2-SiC Ultra-High Temperature Materials

NASA Technical Reports Server (NTRS)

Opila, Elizabeth J.; Smith, Jim; Levine, Stanley R.; Lorincz, Jonathan; Reigel, Marissa

2010-01-01

Hot pressed coupons of composition ZrB2-20 v% SiC-5 v% TaSi2 and ZrB2-20 v% SiC-20 v% TaSi2 were oxidized in stagnant air at temperatures of 1627 and 1927C for one, five and ten 10-minute cycles. The oxidation reactions were characterized by weight change kinetics, x-ray diffraction, and SEM/EDS. Detailed WDS/microprobe quantitative analyses of the oxidation products were conducted for the ZrB2-20 v% SiC-20 v% TaSi2 sample oxidized for five 10-minute cycles at 1927C. Oxidation kinetics and product formation were compared to ZrB2-20 v% SiC with no TaSi2 additions. It was found that the 20 v% TaSi2 composition exhibited improved oxidation resistance relative to the material with no TaSi2 additions at 1627C. However, for exposures at 1927C less oxidation resistance and extensive liquid phase formation were observed compared to the material with no TaSi2 additions. Attempts to limit the liquid phase formation by reducing the TaSi2 content to 5 v% were unsuccessful. In addition, the enhanced oxidation resistance at 1627C due to 20 v% TaSi2 additions was not achieved at the 5 v% addition level. The observed oxidation product evolution is discussed in terms of thermodynamics and phase equilibria for the TaSi2-containing ZrB2-SiC material system. TaSi2-additions to ZrB2-SiC at any level are not recommended for ultra-high temperature (>1900C) applications due to excessive liquid phase formation.

Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA

PubMed Central

Lee, Seonghee; Jia, Yulin; Jia, Melissa; Gealy, David R.; Olsen, Kenneth M.; Caicedo, Ana L.

2011-01-01

The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing. PMID:22043312

TaN resistor process development and integration.

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

Romero, Kathleen; Martinez, Marino John; Clevenger, Jascinda

This paper describes the development and implementation of an integrated resistor process based on reactively sputtered tantalum nitride. Image reversal lithography was shown to be a superior method for liftoff patterning of these films. The results of a response surface DOE for the sputter deposition of the films are discussed. Several approaches to stabilization baking were examined and the advantages of the hot plate method are shown. In support of a new capability to produce special-purpose HBT-based Small-Scale Integrated Circuits (SSICs), we developed our existing TaN resistor process, designed for research prototyping, into one with greater maturity and robustness. Includedmore » in this work was the migration of our TaN deposition process from a research-oriented tool to a tool more suitable for production. Also included was implementation and optimization of a liftoff process for the sputtered TaN to avoid the complicating effects of subtractive etching over potentially sensitive surfaces. Finally, the method and conditions for stabilization baking of the resistors was experimentally determined to complete the full implementation of the resistor module. Much of the work to be described involves the migration between sputter deposition tools - from a Kurt J. Lesker CMS-18 to a Denton Discovery 550. Though they use nominally the same deposition technique (reactive sputtering of Ta with N{sup +} in a RF-excited Ar plasma), they differ substantially in their design and produce clearly different results in terms of resistivity, conformity of the film and the difference between as-deposited and stabilized films. We will describe the design of and results from the design of experiments (DOE)-based method of process optimization on the new tool and compare this to what had been used on the old tool.« less

Synthesis of Ti-Ta alloys with dual structure by incomplete diffusion between elemental powders.

PubMed

Liu, Yong; Li, Kaiyang; Wu, Hong; Song, Min; Wang, Wen; Li, Nianfeng; Tang, Huiping

2015-11-01

In this work, powder metallurgical (PM) Ti-Ta alloys were sintered using blended elemental powders. A dual structure, consisting of Ti-rich and Ta-rich zones, was formed due to the insufficient diffusion between Ti and Ta powders. The microstructure, mechanical properties and in vitro biological properties of the alloys were studied. Results indicated that the alloys have inhomogenous microstructures and compositions, but the grain structures were continuous from the Ti-rich zone to the Ta-rich zone. The Ta-rich zone exhibited a much finer grain size than the Ti-rich zone. The alloys had a high relative density in the range of 95-98%, with the porosity increasing with the content of Ta due to the increased difficulty in sintering and the formation of Kirkendall pores. The alloys had a good combination of low elastic modulus and high tensile strength. The strength of alloys was almost doubled compared to that of the ingot metallurgy alloys with the same compositions. The low elastic modulus was due to the residual pores and the alloying effect of Ta, while the high tensile strength resulted from the strengthening effects of solid solution, fine grain size and α phase. The alloys had a high biocompatibility due to the addition of Ta, and were suitable for the attachment of cells due to the surface porosity. It was also indicated that PM Ti-(20-30)Ta alloys are promising for biomedical applications after the evaluations of both the mechanical and the biological properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Determination of traces of palladium in stream sediment and auto catalyst by FI-ICP-OES using on-line separation and preconcentration with QuadraSil TA.

PubMed

Nakajima, Junichi; Ohno, Masashi; Chikama, Katsumi; Seki, Tatsuya; Oguma, Koichi

2009-09-15

A flow injection analysis (FIA) method using on-line separation and preconcentration with a novel metal scavenger beads, QuadraSil TA, has been developed for the ICP-OES determination of traces of palladium. QuadraSil TA contains diethylenetriamine as a functional group on spherical silica beads and shows the highest selectivity for Pd(II) at pH 1 (0.1 mol l(-1) hydrochloric acid) solution. An aliquot of the sample solution prepared as 0.1 mol l(-1) in hydrochloric acid was passed through the QuadraSil TA column. After washing the column with the carrier solution, the Pd(II) retained on the column was eluted with 0.05 mol l(-1) thiourea solution and the eluate was directly introduced into an ICP-OES. The proposed method was successfully applied to the determination of traces of palladium in JSd-2 stream sediment certified reference material [0.019+/-0.001 microg g(-1) (n=3); provisional value: 0.0212 microg g(-1)] and SRM 2556 used auto catalyst certified reference material [315+/-4 microg g(-1) (n=4); certified value: 326 microg g(-1)]. The detection limit (3 sigma) of 0.28 ng ml(-1) was obtained for 5 ml of sample solution. The sample through puts for 5 ml and 100 microl of the sample solutions were 10 and 15 h(-1), respectively.

From Ba{sub 3}Ta{sub 5}O{sub 14}N to LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2}: Decreasing the optical band gap of a photocatalyst

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

Anke, B.; Bredow, T.; Pilarski, M.

Yellow LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} was successfully synthesized as phase-pure material crystallizing isostructurally to previously reported Ba{sub 3}Ta{sub 5}O{sub 14}N and mixed-valence Ba{sub 3}Ta{sup V}{sub 4}Ta{sup IV}O{sub 15}. The electronic structure of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} was studied theoretically with the range-separated hybrid method HSE06. The most stable structure was obtained when lanthanum was placed on 2a and nitrogen on 4h sites confirming Pauling's second rule. By incorporating nitrogen, the measured band gap decreases from ∼3.8 eV for the oxide via 2.74 eV for Ba{sub 3}Ta{sub 5}O{sub 14}N to 2.63 eV for the new oxide nitride, giving risemore » to an absorption band well in the visible-light region. Calculated fundamental band gaps confirm the experimental trend. The atom-projected density of states has large contributions from N2p orbitals close to the valence band edge. These are responsible for the observed band gap reduction. Photocatalytic hydrogen formation was investigated and compared with that of Ba{sub 3}Ta{sub 5}O{sub 14}N revealing significantly higher activity for LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} under UV-light. - Graphical abstract: X-ray powder diffraction pattern of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} with the results of the Rietveld refinements. Inset: Unit cell of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} and polyhedral representation of the crystal structure. - Highlights: • Synthesis of a new oxide nitride LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2}. • Refinement of the crystal structure. • Quantum chemical calculations provided band gap close to the measured value. • New phase shows a higher photocatalytic H{sub 2} evolution rate compared to prior tested Ba{sub 3}Ta{sub 5}O{sub 14}N.« less

Surfactant-enhanced disinfection of the human norovirus surrogate, Tulane virus, with organic acids and surfactant

USDA-ARS?s Scientific Manuscript database

Combination treatments of surfactants and phenolic or short-chained organic acids (SCOA) may act synergistically or additively as sanitizers to inactive foodborne viruses and prevent outbreaks. The purpose of this study was to investigate the effect of gallic acid (GA), tannic acid (TA), p-coumaric ...

Ectopic expression of Triticum aestivum SERK genes (TaSERKs) control plant growth and development in Arabidopsis.

PubMed

Singh, Akanksha; Khurana, Paramjit

2017-09-28

Somatic embryogenesis receptor kinases (SERKs) belong to a small gene family of receptor-like kinases involved in signal transduction. A total of 54 genes were shortlisted from the wheat genome survey sequence of which 5 were classified as SERKs and 49 were identified as SERK-like (SERLs). Tissue- specific expression of TaSERKs at major developmental stages of wheat corroborates their indispensable role during somatic and zygotic embryogenesis. TaSERK transcripts show inherent differences in their hormonal sensitivities, i.e. TaSERK2 and TaSERK3 elicits auxin- specific responses while TaSERK1, 4 and 5 were more specific towards BR-mediated regulation. The ectopic expression of TaSERK1, 2, 3, 4 and 5 in Arabidopsis led to enhanced plant height, larger silique size and increased seed yield. Zygotic embryogenesis specific genes showed a differential pattern in TaSERK Arabidopsis transgenics specifically in the silique tissues. Elongated hypocotyls and enhanced root growth were observed in the overexpression transgenic lines of all five TaSERKs. The inhibitory action of auxin and brassinosteroid in all the TaSERK transgenic lines indicates their role in regulating root development. The results obtained imply redundant functions of TaSERKs in maintaining plant growth and development.

The ERF transcription factor TaERF3 promotes tolerance to salt and drought stresses in wheat.

PubMed

Rong, Wei; Qi, Lin; Wang, Aiyun; Ye, Xingguo; Du, Lipu; Liang, Hongxia; Xin, Zhiyong; Zhang, Zengyan

2014-05-01

Salinity and drought are major limiting factors of wheat (Triticum aestivum) productivity worldwide. Here, we report the function of a wheat ERF transcription factor TaERF3 in salt and drought responses and the underlying mechanism of TaERF3 function. Upon treatment with 250 mM NaCl or 20% polyethylene glycol (PEG), transcript levels of TaERF3 were rapidly induced in wheat. Using wheat cultivar Yangmai 12 as the transformation recipient, four TaERF3-overexpressing transgenic lines were generated and functionally characterized. The seedlings of the TaERF3-overexpressing transgenic lines exhibited significantly enhanced tolerance to both salt and drought stresses as compared to untransformed wheat. In the leaves of TaERF3-overexpressing lines, accumulation levels of both proline and chlorophyll were significantly increased, whereas H₂O₂ content and stomatal conductance were significantly reduced. Conversely, TaERF3-silencing wheat plants that were generated through virus-induced gene silencing method displayed more sensitivity to salt and drought stresses compared with the control plants. Real-time quantitative RT-PCR analyses showed that transcript levels of ten stress-related genes were increased in TaERF3-overexpressing lines, but compromised in TaERF3-silencing wheat plants. Electrophoretic mobility shift assays showed that the TaERF3 protein could interact with the GCC-box cis-element present in the promoters of seven TaERF3-activated stress-related genes. These results indicate that TaERF3 positively regulates wheat adaptation responses to salt and drought stresses through the activation of stress-related genes and that TaERF3 is an attractive engineering target in applied efforts to improve abiotic stress tolerances in wheat and other cereals. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Overexpression of heat stress-responsive TaMBF1c, a wheat (Triticum aestivum L.) Multiprotein Bridging Factor, confers heat tolerance in both yeast and rice.

PubMed

Qin, Dandan; Wang, Fei; Geng, Xiaoli; Zhang, Liyuan; Yao, Yingyin; Ni, Zhongfu; Peng, Huiru; Sun, Qixin

2015-01-01

Previously, we found an ethylene-responsive transcriptional co-activator, which was significantly induced by heat stress (HS) in both thermo-sensitive and thermo-tolerant wheat. The corresponding ORF was isolated from wheat, and named TaMBF1c (Multiprotein Bridging Factor1c). The deduced amino acid sequence revealed the presence of conserved MBF1 and helix-turn-helix domains at the N- and C-terminus, respectively, which were highly similar to rice ERTCA (Ethylene Response Transcriptional Co-Activator) and Arabidopsis MBF1c. The promoter region of TaMBF1c contained three heat shock elements (HSEs) and other stress-responsive elements. There was no detectable mRNA of TaMBF1c under control conditions, but the transcript was rapidly and significantly induced by heat stress not only at the seedling stage, but also at the flowering stage. It was also slightly induced by drought and H2O2 stresses, as well as by application of the ethylene synthesis precursor ACC, but not, however, by circadian rhythm, salt, ABA or MeJA treatments. Under normal temperatures, TaMBF1c-eGFP protein showed predominant nuclear localization with some levels of cytosol localization in the bombarded onion epidermal cells, but it was mainly detected in the nucleus with almost no eGFP signals in cytosol when the bombarded onion cells were cultured under high temperature conditions. Overexpression of TaMBF1c in yeast imparted tolerance to heat stress compared to cells expressing the vector alone. Most importantly, transgenic rice plants engineered to overexpress TaMBF1c showed higher thermotolerance than control plants at both seedling and reproductive stages. In addition, transcript levels of six Heat Shock Protein and two Trehalose Phosphate Synthase genes were higher in TaMBF1c transgenic lines than in wild-type rice upon heat treatment. Collectively, the present data suggest that TaMBF1c plays a pivotal role in plant thermotolerance and holds promising possibilities for improving heat tolerance

Seismic assessment of Technical Area V (TA-V).

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

Medrano, Carlos S.

The Technical Area V (TA-V) Seismic Assessment Report was commissioned as part of Sandia National Laboratories (SNL) Self Assessment Requirement per DOE O 414.1, Quality Assurance, for seismic impact on existing facilities at Technical Area-V (TA-V). SNL TA-V facilities are located on an existing Uniform Building Code (UBC) Seismic Zone IIB Site within the physical boundary of the Kirtland Air Force Base (KAFB). The document delineates a summary of the existing facilities with their safety-significant structure, system and components, identifies DOE Guidance, conceptual framework, past assessments and the present Geological and Seismic conditions. Building upon the past information and themore » evolution of the new seismic design criteria, the document discusses the potential impact of the new standards and provides recommendations based upon the current International Building Code (IBC) per DOE O 420.1B, Facility Safety and DOE G 420.1-2, Guide for the Mitigation of Natural Phenomena Hazards for DOE Nuclear Facilities and Non-Nuclear Facilities.« less

Interleukin-8 gene polymorphism -251T>A contributes to Alzheimer's disease susceptibility.

PubMed

Qin, Biyong; Li, Li; Wang, Shanshan; Wu, Jun; Huang, Yulan; Zhou, Ping; Bai, Jiao; Zheng, Yan

2016-09-01

Published association studies have investigated the correlation between interleukin-8 (IL-8) gene polymorphism -251T>A and susceptibility to Alzheimer's disease (AD); however, the results are conflicting. Thus, we conducted the meta-analysis to reassess the effect of IL-8 gene -251T>A variant on the risk of AD. Relevant studies regarding this association were electronically searched and identified from the PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and the Chinese Biomedicine Database. The odds ratios (ORs) with the corresponding 95% confidence intervals (95% CIs) were pooled to calculate the strength of this association. Nine studies with a total of 1406 cases and 2152 controls were included in the meta-analysis. Overall, a significant association of IL-8 gene -251T>A polymorphism with increased risk of AD was observed in several genetic models (allele, A vs T: OR=1.32, 95%CI=1.16-1.50; homozygous, AA vs TT: OR=1.70, 95%CI=1.21-2.21; heterozygous, TA vs TT: OR=1.37, 95%CI=1.12-1.69; recessive, AA vs TA+TT: OR=1.40, 95%CI=1.12-1.75). Similarly, such association was also revealed both in Asian and European populations in the subgroup analysis by ethnicity. The current study suggested that IL-8 gene polymorphism -251T>A may contribute to the susceptibility to AD.

27 CFR 24.178 - Amelioration.

Code of Federal Regulations, 2011 CFR

2011-04-01

... is calculated as tartaric acid for grapes, malic acid for apples, and citric acid for other fruit... natural wine from juice having a fixed acid level exceeding 5.0 grams per liter, the winemaker may adjust the fixed acid level by adding ameliorating material (water, sugar, or a combination of both) before...

27 CFR 24.178 - Amelioration.

Code of Federal Regulations, 2010 CFR

2010-04-01

... is calculated as tartaric acid for grapes, malic acid for apples, and citric acid for other fruit... natural wine from juice having a fixed acid level exceeding 5.0 grams per liter, the winemaker may adjust the fixed acid level by adding ameliorating material (water, sugar, or a combination of both) before...

New structures and composition of cell wall teichoic acids from Nocardiopsis synnemataformans, Nocardiopsis halotolerans, Nocardiopsis composta and Nocardiopsis metallicus: a chemotaxonomic value.

PubMed

Tul'skaya, Elena M; Shashkov, Alexander S; Streshinskaya, Galina M; Potekhina, Natalia V; Evtushenko, Ludmila I

2014-12-01

The structures of the cell wall teichoic acids (TA) from some species of the genus Nocardiopsis were established by chemical and NMR spectroscopic methods. The cell walls of Nocardiopsis synnemataformans VKM Ac-2518(T) and Nocardiopsis halotolerans VKM Ac-2519(T) both contain two TA with unique structures-poly(polyol phosphate-glycosylpolyol phosphate)-belonging to the type IV TA. In both organisms, the minor TA have identical structures: poly(glycerol phosphate-N-acetyl-β-galactosaminylglycerol phosphate) with the phosphodiester bond between C-3 of glycerol and C-4 of the amino sugar. This structure is found for the first time. The major TA of N. halotolerans has a hitherto unknown structure: poly(glycerol phosphate-N-acetyl-β-galactosaminylglycerol phosphate), the N-acetyl-β-galactosamine being acetalated with pyruvic acid at positions 4 and 6. The major TA of N. synnemataformans is a poly(glycerol phosphate-N-acetyl-β-galactosaminylglycerol phosphate) with the phosphodiester bond between C-3 of glycerol and C-3 of the amino sugar. The cell walls of Nocardiopsis composta VKM Ac-2520 and N. composta VKM Ac-2521(T) contain only one TA, namely 1,3-poly(glycerol phosphate) partially substituted with N-acetyl-α-glucosamine. The cell wall of Nocardiopsis metallicus VKM Ac-2522(T) contains two TA. The major TA is 1,5-poly(ribitol phosphate), each ribitol unit carrying a pyruvate ketal group at positions 2 and 4. The structure of the minor TA is the same as that of N. composta. The results presented correlate well with the phylogenetic grouping of strains and confirm the species and strain specific features of cell wall TA in members of the genus Nocardiopsis.

Structural Stability of Diffusion Barriers in Cu/Ru/MgO/Ta/Si

PubMed Central

Hsieh, Shu-Huei; Chen, Wen Jauh; Chien, Chu-Mo

2015-01-01

Various structures of Cu (50 nm)/Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm)/Si were prepared by sputtering and electroplating techniques, in which the ultra-thin trilayer of Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm) is used as the diffusion barrier against the interdiffusion between Cu film and Si substrate. The various structures of Cu/Ru/MgO/Ta/Si were characterized by four-point probes for their sheet resistances, by X-ray diffractometers for their crystal structures, by scanning electron microscopes for their surface morphologies, and by transmission electron microscopes for their cross-section and high resolution views. The results showed that the ultra-thin tri-layer of Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm) is an effective diffusion barrier against the interdiffusion between Cu film and Si substrate. The MgO, and Ta layers as deposited are amorphous. The mechanism for the failure of the diffusion barrier is that the Ru layer first became discontinuous at a high temperature and the Ta layer sequentially become discontinuous at a higher temperature, the Cu atoms then diffuse through the MgO layer and to the substrate at the discontinuities, and the Cu3Si phases finally form. The maximum temperature at which the structures of Cu (50 nm)/Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm)/Si are annealed and still have low sheet resistance is from 550 to 750 °C for the annealing time of 5 min and from 500 to 700 °C for the annealing time of 30 min. PMID:28347099

The Efficiency of Delone Coverings of the Canonical Tilings T}(*(A_4)) -> T^*(A4) and T^*(D6)

NASA Astrophysics Data System (ADS)

Papadopolos, Zorka; Kasner, Gerald

This chapter is devoted to the coverings of the two quasiperiodic canonical tilings T}(*(A_4)) -> T^*(A4) and T^*(D6) T^*(2F), obtained by projection from the root lattices A4 and D6, respectively. In the first major part of this chapter, in Sect. 5.2, we shall introduce a Delone covering T}(*(A_4)}) -> C^sT^*(A4) of the 2-dimensional decagonal tiling T}(*(A_4)) -> T^*(A4). In the second major part of this chapter, Sect. 5.3, we summarize the results related to the Delone covering of the icosahedral tiling T^*(D6), CT^*(D6) and determine the zero-, single-, and double- deckings and the resulting thickness of the covering. In the conclusions section, we give some suggestions as to how the definition of the Delone covering might be changed in order to reach some real (full) covering of the icosahedral tiling T^*(D6). In Section 5.2 the definition of the Delone covering is also changed in order to avoid an unnecessary large thickness of the covering.

Tranexamic Acid in the Treatment of Melasma: A Review of the Literature.

PubMed

Perper, Marina; Eber, Ariel Eva; Fayne, Rachel; Verne, Sebastian Hugo; Magno, Robert James; Cervantes, Jessica; ALharbi, Mana; ALOmair, Ibrahim; Alfuraih, Abdulkarem; Nouri, Keyvan

2017-06-01

Melasma is a common acquired pigmentary disorder marked by irregular hyperpigmented macules or patches and most commonly occurs in women of darker skin color. It is a chronic often-relapsing condition that causes negative psychosocial effects in those affected. Current treatments such as hydroquinone, kojic acid, and retinoids, among others, demonstrate variable efficacy and side-effect profiles. We conducted a comprehensive literature review examining the use of tranexamic acid (TA), a well-known anti-fibrinolytic agent, in the treatment of melasma. TA delivered orally, topically, and through physical methods works via the inhibition of ultraviolet (UV)-induced plasmin activity in keratinocytes. Predefined search terms were entered into PubMed. Articles were then independently screened by two authors to include only those written in the English language and relating to human subjects with at least mild melasma. The search identified 28 articles, 15 of which met the criteria for full review. The review revealed that TA treatment for melasma is equally effective or more effective than other standard therapies and may induce fewer side effects. Our comprehensive review suggests that TA may be a promising treatment option for melasma because of its demonstrated effectiveness alone and in combination with other modalities as well as its limited side-effect profile.

Organic acids, amino acids compositions in the root exudates and Cu-accumulation in castor (Ricinus communis L.) Under Cu stress.

PubMed

Huang, Guoyong; Guo, Guangguang; Yao, Shiyuan; Zhang, Na; Hu, Hongqing

2016-01-01

Ricinus communis L. is a hyperaccumulation plant newly discovered in an abandoned land of Cu mine in China. A hydroponic experiment was then carried out to determine the root exudates in the Cu-tolerant castor (Ricinus communis L.). Plants were grown in nutrient solution with increasing level of Cu doses (0, 100, 250, 500, and 750 μmol/L Cu) in the form of CuSO4. Cu accumulation in the roots and shoots of castor, and root exudates collected from the castor were measured. The results indicated that the castor had a high Cu accumulation capacity and the Cu concentrations in the shoots and roots of the castor treated with 750 μmol/L Cu were 177.1, 14586.7 mg/kg, respectively. Tartaric was the largest in the root exudates in terms of concentrations, which reached up to 329.13 μmol/g (dry plant) in the level of 750 μmol/L Cu. There was a significantly positive linear relationship between the Cu concentration in root and the concentration of succinic (R = 0.92, P < 0.05), tartaric (R = 0.96, P < 0.01), and citric (R = 0.89, P < 0.05). These results indicated that the difference in root exudation from castor could affect their Cu tolerance. What is more, significant is that the high tartaric and citric, the low oxalic and cysteine in the root exudation of castor contributed to toleration of high Cu concentrations.

Oxygen related recombination defects in Ta{sub 3}N{sub 5} water splitting photoanode

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

Fu, Gao; Yu, Tao, E-mail: yscfei@nju.edu.cn, E-mail: yutao@nju.edu.cn; Zou, Zhigang

2015-10-26

A key route to improving the performance of Ta{sub 3}N{sub 5} photoelectrochemical film devices in solar driving water splitting to hydrogen is to understand the nature of the serious recombination of photo-generated carriers. Here, by using the temperature-dependent photoluminescence (PL) spectrum, we confirmed that for the Ta{sub 3}N{sub 5} films prepared by nitriding Ta{sub 2}O{sub 5} precursor, one PL peak at 561 nm originates from deep-level defects recombination of the oxygen-enriched Ta{sub 3}N{sub 5} phases, and another one at 580 nm can be assigned to band recombination of Ta{sub 3}N{sub 5} itself. Both of the two bulk recombination processes may decrease themore » photoelectrochemical performance of Ta{sub 3}N{sub 5}. It was difficult to remove the oxygen-enriched impurities in Ta{sub 3}N{sub 5} films by increasing the nitriding temperatures due to their high thermodynamically stability. In addition, a broadening PL peak between 600 and 850 nm resulting from oxygen related surface defects was observed by the low-temperature PL measurement, which may induce the surface recombination of photo-generated carriers and can be removed by increasing the nitridation temperature. Our results provided direct experimental evidence to understand the effect of oxygen-related crystal defects in Ta{sub 3}N{sub 5} films on its photoelectric performance.« less

Experimental design for extraction and quantification of phenolic compounds and organic acids in white "Vinho Verde" grapes.

PubMed

Dopico-García, M S; Valentão, P; Guerra, L; Andrade, P B; Seabra, R M

2007-01-30

An experimental design was applied for the optimization of extraction and clean-up processes of phenolic compounds and organic acids from white "Vinho Verde" grapes. The developed analytical method consisted in two steps: first a solid-liquid extraction of both phenolic compounds and organic acids and then a clean-up step using solid-phase extraction (SPE). Afterwards, phenolic compounds and organic acids were determined by high-performance liquid chromatography (HPLC) coupled to a diode array detector (DAD) and HPLC-UV, respectively. Plackett-Burman design was carried out to select the significant experimental parameters affecting both the extraction and the clean-up steps. The identified and quantified phenolic compounds were: quercetin-3-O-glucoside, quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, isorhamnetin-3-O-glucoside, quercetin, kaempferol and epicatechin. The determined organic acids were oxalic, citric, tartaric, malic, shikimic and fumaric acids. The obtained results showed that the most important variables were the temperature (40 degrees C) and the solvent (acid water at pH 2 with 5% methanol) for the extraction step and the type of sorbent (C18 non end-capped) for the clean-up step.

μX-ray fluorescence analysis of traces and calcium phosphate phases on tooth tartar interfaces using synchrotron radiation

NASA Astrophysics Data System (ADS)

Abraham, J. A.; Grenón, M. S.; Sánchez, H. J.; Valentinuzzi, M. C.; Perez, C. A.

2007-07-01

Hard dental tissues like dentine and cementum with calcified deposits (dental calculi) were studied in several human dental pieces of adult individuals from the same geographic region. A couple of cross cuts were performed at dental root level resulting in a planar slice with calculus and dental tissue exposed for analysis. The elemental content along a linear path crossing the dentine-cementum-tartar interfaces and also all over a surface was measured by X-ray fluorescence microanalysis using synchrotron radiation (μSRXRF). The concentration of elemental traces like K, V, Cu, Zn, As, Br and Sr showed different features on the analyzed regions. The possible connections with the dynamic of mineralization and biological implications are discussed. The concentrations of major elements Ca and P were also determined and the measured Ca/P molar ratio was used to estimate the average composition of calcium phosphate phases in the measured points. A deeper knowledge of the variations of the elemental compositions and the changes of the different phases will help to a better understanding of the scarcely known mechanism of calculus growing.

Tannic acid induces in vitro acantholysis of keratinocytes via IL-1alpha and TNF-alpha.

PubMed

Feliciani, C; Ruocco, E; Zampetti, A; Toto, P; Amerio, Pa; Tulli, A; Amerio, P; Ruocco, V

2007-01-01

The mechanism of acantholysis in pemphigus vulgaris (PV) is an intriguing argument since several chemical mediators are implicated. We previously reported a central role for IL-1alpha and TNF- alpha, both able to regulate complement activation and plasminogen activators. Very little is known about what triggers the disease (drugs, viruses or food). In this study, we evaluate the molecular role of tannins in acantholysis. By HPLC chromatography we measured tannic acid (TA) and gallic acid (GA) in blister fluid of 4 groups of patients divided according to their dietary habits, including a regular diet, a diet rich in tannins, a diet free of tannins, and a group of pemphigus patients. Blister fluid was obtained from patients using a suction blister apparatus. We show that people with a diet rich in tannins have increased tannin metabolites (TA and GA) in the skin in respect to controls (tannin-rich diet: GA = 194.52+/-2.39 nmol/ml; TA = 348.28+/-1.4 nmol/ml versus tannin-Mediterranean diet: GA = 15.28+/-1.63 nmol/ml; TA = 22.81+/-1.68 nmol/ml). PV patients showed similar values to the Mediterranean diet population (PV patients: GA = 95.8+/-1.97 nmol/ml; TA = 199.09+/-4.15 nmol/ml versus Mediterranean diet: GA = 83.53+/-2.35 nmol/ml; TA = 195.1+/-2.50 nmol/ml). In an in vitro acantholysis system using TA and PV-IgG we show that TA 0.1 mM in NHEK culture is able to induce acantholysis. This effect was able to amplify the acantholytic action of PV-IgG in vitro. A blocking study using anti IL-1 alpha and anti TNF-alpha antibodies showed a reduction in TA-induced acantholysis. Taken together, these results suggest that a diet rich in tannins could be a trigger in genetically predisposed patients. If these data are confirmed, a complementary diet poor in tannins may be useful in patients affected by PV.

Superconducting order from disorder in 2H-TaSe 2-xS x

DOE PAGES

Li, Lijun; Deng, Xiaoyu; Wang, Zhen; ...

2017-02-24

Here, we report on the emergence of robust superconducting order in single crystal alloys of TaSe 2$ -$x S x (0 ≤ × ≤2). The critical temperature of the alloy is surprisingly higher than that of the two end compounds TaSe2 and TaS2. The evolution of superconducting critical temperature T c(x) correlates with the full width at half maximum of the Bragg peaks and with the linear term of the high-temperature resistivity. The conductivity of the crystals near the middle of the alloy series is higher or similar than that of either one of the end members 2H-TaSe 2 and/ormore » 2H-TaS 2. It is known that in these materials superconductivity is in close competition with charge density wave order. We interpret our experimental findings in a picture where disorder tilts this balance in favor of superconductivity by destroying the charge density wave order.« less

Experiment and density functional theory analyses of GdTaO4 single crystal

NASA Astrophysics Data System (ADS)

Ding, Shoujun; Kinross, Ashlie; Wang, Xiaofei; Yang, Huajun; Zhang, Qingli; Liu, Wenpeng; Sun, Dunlu

2018-05-01

GdTaO4 is a type of excellent materials that can be used as scintillation, laser matrix as well as self-activated phosphor has generated significant interest. Whereas its band structure, electronic structure and optical properties are still need elucidation. To solve this intriguing problem, high-quality GdTaO4 single crystal (M-type) was grown successfully using Czochralski method. Its structure as well as optical properties was determined in experiment. Moreover, a systematic theoretical calculation based on the density function theory methods were performed on M-type and M‧-type GdTaO4 and their band structure, density of state as well as optical properties were obtained. Combine with the performed experiment results, the calculated results were proved with high reliability. Hence, the calculated results obtained in this work could provide a deep understanding of GdTaO4 material, which also useful for the further investigation on GdTaO4 material.

Effect of Manufacturing Process on the Biocompatibility and Mechanical Properties of Ti-30Ta Alloy

NASA Astrophysics Data System (ADS)

Gill, P.; Munroe, N.; Pulletikurthi, C.; Pandya, S.; Haider, W.

2011-07-01

Ti alloys have been widely used in the aerospace, chemical, and biomedical industries for their high strength/weight ratio and corrosion resistance. However, Nitinol's usage in the latter industry has been fraught with concerns of allergic and toxic effects of Ni released from implants. Recently, much attention has been placed on the development of Ni-free Ti-Ta alloys, which are considered prime candidates for applications such as metal-on-metal spinal disk replacements, orthopedic implants, cardiovascular stents, dental posts, and guide wires. In this research, the biocompatibility of Ti-30Ta alloys manufactured by powder metallurgy (PM) and arc melting (ARC) were investigated. The corrosion resistance of each alloy was determined in accordance with ASTM F 2129-08 in phosphate buffered saline (PBS) and PBS with amino acids at 37 °C. The concentration of metal ions released during corrosion was measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Scanning Electron Microscopy (SEM) was used to assess the morphology of the alloys before and after corrosion. Vicker's hardness tests were performed to compare the hardness and tensile strength of the alloys. Human osteoblast cells were successfully grown on the surface of both alloys.

Insights into teichoic acid biosynthesis by Bifidobacterium bifidum PRL2010.

PubMed

Colagiorgi, Angelo; Turroni, Francesca; Mancabelli, Leonardo; Serafini, Fausta; Secchi, Andrea; van Sinderen, Douwe; Ventura, Marco

2015-09-01

Bifidobacteria are colonizers of the human gut, where they are interacting with their host as well as with other members of the intestinal microbiota. Teichoic acids (TAs) have previously been shown to play an important role in modulating microbe-host interactions in the human gut. However, so far, there is a paucity of information regarding the presence of TAs in the cell envelope of bifidobacteria. In silico analyses targeting the chromosomes of all 48 (sub)species that currently represent the genus Bifidobacterium revealed the presence of genes responsible for TA biosynthesis, suggesting that bifidobacteria contain both wall TAs and lipoteichoic acids. Transcriptome analyses of the infant gut commensal Bifidobacterium bifidum PRL2010 highlighted that the transcription of the presumptive TA biosynthetic loci is modulated in response to environmental conditions reflecting those of the human gut. Furthermore, chemical characterization of TAs produced by PRL2010 indicates the presence of lipoteichoic acids. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nano suboxide layer generated in Ta{sub 2}O{sub 5} by Ar{sup +} ion irradiation

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

Song, W. D., E-mail: song-wendong@dsi.a-star.edu.sg, E-mail: ying-ji-feng@dsi.a-star.edu.sg; Ying, J. F., E-mail: song-wendong@dsi.a-star.edu.sg, E-mail: ying-ji-feng@dsi.a-star.edu.sg; He, W.

2015-01-19

Ta{sub 2}O{sub 5}/TaO{sub x} heterostructure has become a leading oxide layer in memory cells and/or a bidirectional selector for resistive random access memory (RRAM). Although atomic layer deposition (ALD) was found to be uniquely suitable for depositing uniform and conformal films on complex topographies, it is hard to use ALD to grow suboxide TaO{sub x} layer. In this study, tantalum oxide films with a composition of Ta{sub 2}O{sub 5} were grown by ALD. Using Ar{sup +} ion irradiation, the suboxide was formed in the top layer of Ta{sub 2}O{sub 5} films by observing the Ta core level shift toward lowermore » binding energy with angle-resolved X-ray photoelectron spectroscopy. By controlling the energy and irradiation time of an Ar{sup +} ion beam, Ta{sub 2}O{sub 5}/TaO{sub x} heterostructure can be reliably produced on ALD films, which provides a way to fabricate the critical switching layers of RRAM.« less

Investigation of the Formation Process of Two Piracetam Cocrystals during Grinding

PubMed Central

Rehder, Sönke; Klukkert, Marten; Löbmann, Korbinian A. M.; Strachan, Clare J.; Sakmann, Albrecht; Gordon, Keith; Rades, Thomas; Leopold, Claudia S.

2011-01-01

Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e., piracetam-citric acid and piracetam-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to progress via an amorphous intermediate stage, which was more evident for the piracetam-citric acid than for the piracetam-tartaric acid cocrystal. It was shown that liquid-assisted grinding led to faster cocrystal formation than dry grinding, which may be explained by the higher transformation rate due to the presence of liquid. The cocrystal formation rate did not depend on the applied polymorphic form of the piracetam and no polymorphic cocrystals were obtained. PMID:24309304

Synthesis and electrochemical characterization of Ti{sub x}Ta{sub y}Al{sub z}N{sub 1-δ}O{sub γ} for fuel cell catalyst supports

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

Wakabayashi, Ryo H.; Abruña, Héctor D., E-mail: hda1@cornell.edu; DiSalvo, Francis J., E-mail: fjd3@cornell.edu

2017-02-15

Quinary Ti{sub x}Ta{sub y}Al{sub z}N{sub 1-δ}O{sub γ} of various compositions have been prepared by a co-precipitation method followed by ammonolysis. The nitride samples were examined as potential catalyst supports in polymer electrolyte membrane fuel cells. The nitride products crystallized in the rock salt (NaCl) structure over a wide range of compositions. The addition of Ta and Al was highly beneficial towards improving the chemical and electrochemical stability of TiN, without a significant loss of electrical conductivity. Platinum particles were successfully deposited on the (oxy)nitride samples, and the composite samples at some compositions were found to be comparable to Pt/carbon inmore » their stability and catalytic activity even without optimizing the Pt deposition and dispersion processes. - Graphical abstract: The effect of additions of Ta and Al into TiN structure. Shifts the lattice constant, and increases its chemical stability in acidic environment.« less

Mechanism of the reset process in bipolar-resistance-switching Ta/TaOx/Pt capacitors based on observation of the capacitance and resistance

NASA Astrophysics Data System (ADS)

Na, Sang-Chul; Kim, Jae-Jun; Chul Chun, Min; Hee Jin, Da; Ahn, Seung-Eon; Soo Kang, Bo

2014-03-01

The capacitance (C) and the resistance (R) were measured at various states as the reset process progressed in bipolar-resistance-switching Ta/TaOx/Pt thin film capacitors. The reset process was found to undergo three sequential stages where C and R showed different behavior: increasing C and constant R before an abrupt reset transition, the rapid increase of both C and R upon transition, and saturated C thereafter. These behaviors can be explained in terms of the annihilation of the oxygen vacancies followed by rupture of the conducting channels.

Brittle and ductile adjustable cement derived from calcium phosphate cement/polyacrylic acid composites.

PubMed

Chen, Wen-Cheng; Ju, Chien-Ping; Wang, Jen-Chyan; Hung, Chun-Cheng; Chern Lin, Jiin-Huey

2008-12-01

Bone filler has been used over the years in dental and biomedical applications. The present work is to characterize a non-dispersive, fast setting, modulus adjustable, high bioresorbable composite bone cement derived from calcium phosphate-based cement combined with polymer and binding agents. This cement, we hope, will not swell in simulated body fluid and keep the osteogenetic properties of the dry bone and avoid its disadvantages of being brittle. We developed a calcium phosphate cement (CPC) of tetracalcium phosphate/dicalcium phosphate anhydrous (TTCP/DCPA)-polyacrylic acid with tartaric acid, calcium fluoride additives and phosphate hardening solution. The results show that while composite, the hard-brittle properties of 25wt% polyacrylic acid are proportional to CPC and mixing with additives is the same as those of the CPC without polyacrylic acid added. With an increase of polyacrylic acid/CPC ratio, the 67wt% samples revealed ductile-tough properties and 100wt% samples kept ductile or elastic properties after 24h of immersion. The modulus range of this development was from 200 to 2600MPa after getting immersed in simulated body fluid for 24h. The TTCP/DCPA-polyacrylic acid based CPC demonstrates adjustable brittle/ductile strength during setting and after immersion, and the final reaction products consist of high bioresorbable monetite/brushite/calcium fluoride composite with polyacrylic acid.

Investigations into Ti-(Nb,Ta)-Fe alloys for biomedical applications.

PubMed

Biesiekierski, Arne; Lin, Jixing; Li, Yuncang; Ping, Dehai; Yamabe-Mitarai, Yoko; Wen, Cuie

2016-03-01

In this study, a Ti-(Ta,Nb)-Fe system was investigated with aims toward the development of high strength, biocompatible titanium alloy suitable for the development of porous orthopedic biomaterials with minimal processing. Notable findings include yield strengths of 740, 1250 and 1360 MPa for the Ti-12Nb-5Fe, Ti-7Ta-5Fe and Ti-10Ta-4Fe alloys, respectively, with elastic moduli comparable to existing Ti-alloys, yielding admissible strains of 0.9 ± 0.3, 1.2 ± 0.2 and 1.13 ± 0.02% for the Ti-12Nb-5Fe, Ti-7Ta-5Fe and Ti-10Ta-4Fe alloys, respectively; more than twice that of human bone. Observed microstructure varied significantly depending on alloy; near pure β-phase was seen in Ti-12Nb-5Fe, β with some ω precipitation in Ti-10Ta-4Fe, and a duplex α+β structure was observed throughout the Ti-7Ta-5Fe. In addition to suitable mechanical parameters, all investigated alloys exhibited promising corrosion potentials on the order of -0.24 V SCE, equalling that seen for a C.P.-Ti control at -0.25V SCE, and substantially more noble than that seen for Ti-6Al-4V. Electrochemical corrosion rates of 0.5-3 μm/year were likewise seen to agree well with that measured for C.P.-Ti. Further, no statistically significant difference could be seen between any of the alloys relative to a C.P.-Ti control regards to cell proliferation, as investigated via MTS assay and confocal microscopy. As such, the combination of high admissible strain and low corrosion indicate all investigated alloys show significant promise as potential porous biomaterials while in the as-cast state, with the Ti-10Ta-4Fe alloy identified as the most promising composition investigated. The findings of this paper are of significance to the field of metallic biomaterials as they detail the development of alloys of satisfactory biocompatibility and electrochemical behaviour, that furthermore display exceptional mechanical properties. Notably, both extremely high compressive yield strengths and admissible strains

Wheat TaPUB1 modulates plant drought stress resistance by improving antioxidant capability.

PubMed

Zhang, Guangqiang; Zhang, Meng; Zhao, Zhongxian; Ren, Yuanqing; Li, Qinxue; Wang, Wei

2017-08-08

E3 ligases play significant roles in plant stress tolerance by targeting specific substrate proteins for post-translational modification. In a previous study, we cloned TaPUB1 from Triticum aestivum L., which encodes a U-box E3 ligase. Real-time polymerase chain reaction revealed that the gene was up-regulated under drought stress. To investigate the function of TaPUB1 in the response of plants to drought, we generated transgenic Nicotiana benthamiana (N. benthamiana) plants constitutively expressing TaPUB1 under the CaMV35S promoter. Compared to wild type (WT), the transgenic plants had higher germination and seedling survival rates as well as higher photosynthetic rate and water retention, suggesting that the overexpression of TaPUB1 enhanced the drought tolerance of the TaPUB1 overexpressing (OE) plants. Moreover, less accumulation of reactive oxygen species (ROS) and stronger antioxidant capacity were detected in the OE plants than in the WT plants. To characterize the mechanisms involved, methyl viologen (MV) was used to induce oxidative stress conditions and we identified the functions of this gene in the plant tolerance to oxidative stress. Our results suggest that TaPUB1 positively modulates plant drought stress resistance potential by improving their antioxidant capacity.

Effects of a Ta interlayer on the phase transition of TiSi2 on Si(111)

NASA Astrophysics Data System (ADS)

Jeon, Hyeongtag; Jung, Bokhee; Kim, Young Do; Yang, Woochul; Nemanich, R. J.

2000-09-01

This study examines the effects of a thin Ta interlayer on the formation of TiSi2 on Si(111) substrate. The Ta interlayer was introduced by depositing Ta and Ti films sequentially on an atomically clean Si(111) substrate in an ultrahigh vacuum (UHV) system. Samples of 100 Å Ti with 5 and 10 Å Ta interlayers were compared to similar structures without an interlayer. After deposition, the substrates were annealed for 10 min, in situ, at temperatures between 500 and 750 °C in 50 °C increments. The TiSi2 formation with and without the Ta interlayer was analyzed with an X-ray diffractometer, Auger electron spectroscopy (AES), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and a four-point probe. The AES analysis data showed a 1:2 ratio of Ti:Si in the Ti-silicide layer and indicated that the Ta layer remained at the interface between TiSi2 and the Si(111) substrate. The C 49-C 54 TiSi2 phase transition temperature was lowered by ˜200 °C. The C 49-C 54 TiSi2 phase transition temperature was 550 °C for the samples with a Ta interlayer and was 750 °C for the samples with no Ta interlayer. The sheet resistance of the Ta interlayered Ti silicide showed lower values of resistivity at low temperatures which indicated the change in phase transition temperature. The C 54 TiSi2 displayed different crystal orientation when the Ta interlayer was employed. The SEM and TEM micrographs showed that the TiSi2 with a Ta interlayer significantly suppressed the tendency to islanding and surface agglomeration.

75 FR 66794 - Notice of Affirmative Determination Regarding Application for Reconsideration: TA-W-71,572...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-29

...., Steubenville, OH By applications dated May 15 and May 21, 2010, United Steel, Paper and Forestry, Rubber... back plate coils (TA-W-71,572A), hot rolled coils (TA- W-71,572B), and cold rolled coils (TA-W-71,572C...

Virus-Induced Gene Silencing Identifies an Important Role of the TaRSR1 Transcription Factor in Starch Synthesis in Bread Wheat.

PubMed

Liu, Guoyu; Wu, Yufang; Xu, Mengjun; Gao, Tian; Wang, Pengfei; Wang, Lina; Guo, Tiancai; Kang, Guozhang

2016-09-23

The function of a wheat starch regulator 1 (TaRSR1) in regulating the synthesis of grain storage starch was determined using the barley stripe mosaic virus-virus induced gene-silencing (BSMV-VIGS) method in field experiments. Chlorotic stripes appeared on the wheat spikes infected with barley stripe mosaic virus-virus induced gene-silencing- wheat starch regulator 1 (BSMV-VIGS-TaRSR1) at 15 days after anthesis, at which time the transcription levels of the TaRSR1 gene significantly decreased. Quantitative real-time PCR was also used to measure the transcription levels of 26 starch synthesis-related enzyme genes in the grains of BSMV-VIGS-TaRSR1-silenced wheat plants at 20, 27, and 31 days after anthesis. The results showed that the transcription levels of some starch synthesis-related enzyme genes were markedly induced at different sampling time points: TaSSI, TaSSIV, TaBEIII, TaISA1, TaISA3, TaPHOL, and TaDPE1 genes were induced at each of the three sampling time points and TaAGPS1-b, TaAGPL1, TaAGPL2, TaSSIIb, TaSSIIc, TaSSIIIb, TaBEI, TaBEIIa, TaBEIIb, TaISA2, TaPHOH, and TaDPE2 genes were induced at one sampling time point. Moreover, both the grain starch contents, one thousand kernel weights, grain length and width of BSMV-VIGS-TaRSR1-infected wheat plants significantly increased. These results suggest that TaRSR1 acts as a negative regulator and plays an important role in starch synthesis in wheat grains by temporally regulating the expression of specific starch synthesis-related enzyme genes.

Virus-Induced Gene Silencing Identifies an Important Role of the TaRSR1 Transcription Factor in Starch Synthesis in Bread Wheat

PubMed Central

Liu, Guoyu; Wu, Yufang; Xu, Mengjun; Gao, Tian; Wang, Pengfei; Wang, Lina; Guo, Tiancai; Kang, Guozhang

2016-01-01

The function of a wheat starch regulator 1 (TaRSR1) in regulating the synthesis of grain storage starch was determined using the barley stripe mosaic virus—virus induced gene-silencing (BSMV-VIGS) method in field experiments. Chlorotic stripes appeared on the wheat spikes infected with barley stripe mosaic virus-virus induced gene-silencing- wheat starch regulator 1 (BSMV-VIGS-TaRSR1) at 15 days after anthesis, at which time the transcription levels of the TaRSR1 gene significantly decreased. Quantitative real-time PCR was also used to measure the transcription levels of 26 starch synthesis-related enzyme genes in the grains of BSMV-VIGS-TaRSR1-silenced wheat plants at 20, 27, and 31 days after anthesis. The results showed that the transcription levels of some starch synthesis-related enzyme genes were markedly induced at different sampling time points: TaSSI, TaSSIV, TaBEIII, TaISA1, TaISA3, TaPHOL, and TaDPE1 genes were induced at each of the three sampling time points and TaAGPS1-b, TaAGPL1, TaAGPL2, TaSSIIb, TaSSIIc, TaSSIIIb, TaBEI, TaBEIIa, TaBEIIb, TaISA2, TaPHOH, and TaDPE2 genes were induced at one sampling time point. Moreover, both the grain starch contents, one thousand kernel weights, grain length and width of BSMV-VIGS-TaRSR1-infected wheat plants significantly increased. These results suggest that TaRSR1 acts as a negative regulator and plays an important role in starch synthesis in wheat grains by temporally regulating the expression of specific starch synthesis-related enzyme genes. PMID:27669224

Tannic acid mitigates the DMBA/croton oil-induced skin cancer progression in mice.

PubMed

Majed, Ferial; Rashid, Summya; Khan, Abdul Quaiyoom; Nafees, Sana; Ali, Nemat; Ali, Rashid; Khan, Rehan; Hasan, Syed Kazim; Mehdi, Syed Jafar; Sultana, Sarwat

2015-01-01

Skin cancer is the most common malignancy in the world and also one of the major causes of death worldwide. The toxic environmental pollutant 7,12-dimethylbenz[a]anthracene (DMBA) is a skin-specific carcinogen. Tannic acid (TA) is reported to be effective against various types of chemical-induced toxicities and carcinogenesis as well. In the present study, we have evaluated the therapeutic potential of tannic acid in DMBA + croton oil-induced skin cancer in Swiss albino mice. Protective effect of TA against skin cancer was evaluated in terms of antioxidant enzymes activities, lipid peroxidation, histopathological changes and expression of inflammation and early tumour markers. DMBA + croton oil causes depletion of antioxidant enzymes (p < 0.001) and elevation of early inflammatory and tumour promotional events. TA prevents the DMBA + croton oil-induced toxicity through a protective mechanism that involves the reduction of oxidative stress as well as COX-2, i-NOS, PCNA protein expression and level of proinflammatory cytokine such as IL-6 release at a very significant level (p < 0.001). It could be concluded from our results that TA attenuates DMBA + croton oil-induced tumour promotional potential possibly by inhibiting oxidative and inflammatory responses and acts as antioxidant, anti-inflammatory and antiproliferative agent.

Methylmercury production in soil in the water-level-fluctuating zone of the Three Gorges Reservoir, China: The key role of low-molecular-weight organic acids.

PubMed

Yin, Deliang; Wang, Yongmin; Jiang, Tao; Qin, Caiqing; Xiang, Yuping; Chen, Qiuyu; Xue, Jinping; Wang, Dingyong

2018-04-01