Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion.

PubMed

Aslan, Selcuk; Hofvander, Per; Dutta, Paresh; Sun, Chuanxin; Sitbon, Folke

2015-12-01

Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future.

Tailoring Pore Size and Chemical Interior of near 1 nm Sized Pores in a Nanoporous Polymer Based on a Discotic Liquid Crystal

PubMed Central

2017-01-01

A triazine based disc shaped molecule with two hydrolyzable units, imine and ester groups, was polymerized via acyclic diene metathesis in the columnar hexagonal (Colhex) LC phase. Fabrication of a cationic nanoporous polymer (pore diameter ∼1.3 nm) lined with ammonium groups at the pore surface was achieved by hydrolysis of the imine linkage. Size selective aldehyde uptake by the cationic porous polymer was demonstrated. The anilinium groups in the pores were converted to azide as well as phenyl groups by further chemical treatment, leading to porous polymers with neutral functional groups in the pores. The pores were enlarged by further hydrolysis of the ester groups to create ∼2.6 nm pores lined with −COONa surface groups. The same pores could be obtained in a single step without first hydrolyzing the imine linkage. XRD studies demonstrated that the Colhex order of the monomer was preserved after polymerization as well as in both the nanoporous polymers. The porous anionic polymer lined with −COOH groups was further converted to the −COOLi, −COONa, −COOK, −COOCs, and −COONH4 salts. The porous polymer lined with −COONa groups selectively adsorbs a cationic dye, methylene blue, over an anionic dye. PMID:28416888

Graphene oxide based sol-gel stainless steel fiber for the headspace solid-phase microextraction of organophosphate ester flame retardants in water samples.

PubMed

Jin, Tingting; Cheng, Jing; Cai, Cuicui; Cheng, Min; Wu, Shiju; Zhou, Hongbin

2016-07-29

In this paper, graphene oxide was coated onto a stainless steel wire through sol-gel technique and it was used as a solid phase microextraction (SPME) fiber. The prepared fiber was characterized by scanning electron microscopy (SEM), which displayed that the fiber had crinkled surface and porous structure The application of the fiber was evaluated through the headspace SPME of nine organophosphate ester flame retardants (OPFRs) with different characteristics in water samples followed by gas chromatography and nitrogen-phosphorous detector (GC/NPD). The major factors influencing the extraction efficiency, including the extraction and desorption conditions, were studied and optimized. Under the optimum conditions, the proposed method was evaluated, and applied to the analysis of organophosphate ester flame retardants in real environmental water samples. The results demonstrated the HS-SPME method based on GO sol-gel fiber had good linearity (R>0.9928), and limits of detection (1.4-135.6ngL(-1)), high repeatability (RSD<9.8%) and good recovery (76.4-112.4%). The GO based sol-gel fiber displayed bigger extraction capability than the commercial PDMS fiber and the pure sol-gel fiber for both polar and apolar organophosphate esters, especially for the OPFRs containing benzene rings. Copyright © 2016 Elsevier B.V. All rights reserved.

Relationship between columnar cell changes and low-grade carcinoma in situ of the breast--a cytogenetic study.

PubMed

Go, Edna May L; Tsang, Julia Y S; Ni, Yun-Bi; Yu, Alex M; Mendoza, Paulo; Chan, Siu-Ki; Lam, Christopher C; Lui, Philip C; Tan, Puay-Hoon; Tse, Gary M

2012-11-01

Columnar cell lesions of the breast include columnar cell changes without atypia and columnar cell changes with atypia. The latter frequently coexist and share molecular changes with low-grade carcinoma in situ and invasive carcinoma, suggesting that columnar cell changes may be precursors to progression of low-grade advanced lesions. In this study, we assessed chromosomal aberrations at 16q, hallmark for low-grade lesions, in columnar cell changes with or without atypia and their adjacent carcinoma in situ by fluorescent in situ hybridization using 3 region-specific probes spanning the entire chromosomal arm. The results were correlated with the histomorphological features of the corresponding lesions. Forty-four percent of low-grade carcinoma in situ and 31% of high-grade carcinoma in situ were associated with columnar cell changes with atypia, suggesting a link between columnar cell changes with atypia and low-grade carcinoma in situ. For the genetic aberrations, heterozygous deletion of 16q was present in 56% of low-grade carcinoma in situ but only in 19% of high-grade carcinoma in situ. Conversely, aneuploidy was found mostly in high-grade carcinoma in situ (88%). Twenty percent of columnar cell changes with atypia but none of the columnar cell changes without atypia showed heterozygous deletion of 16q. Interestingly, the same changes in 16q were observed in the columnar cell changes and their associated low-grade carcinoma in situ lesions. These findings demonstrated a genetic commonality between columnar cell changes with atypia and low-grade carcinoma in situ and substantiated the precursor role of columnar cell changes with atypia for low-grade carcinoma in situ but not high-grade carcinoma in situ of the breast. Copyright © 2012 Elsevier Inc. All rights reserved.

The role of basal cells in adhesion of columnar epithelium to airway basement membrane.

PubMed

Evans, M J; Plopper, C G

1988-08-01

In this report, we present a new concept of the role of the basal cell in airway epithelium. Previously, the basal cell was thought to be the progenitor cell for the columnar epithelium. However, several studies have shown that this concept may not be correct. The morphologic aspects of the basal cell suggest that it could play a role in adhesion of the columnar epithelium to the basement membrane. Basal cells form attachments with columnar cells (desmosomes) and with the basement membrane (hemidesmosomes). Columnar cells do not form hemidesmosome attachments with the basement membrane. Basal cells could strengthen the adhesion of columnar cells to the basement membrane by forming hemidesmosome attachments to the basement membrane and desmosome attachments with adjacent columnar cells. Incidental evidence from 2 existing publications concerning airway microanatomy support this concept. As columnar cells grow taller, the proportion of the cell surface in contact with the basement membrane becomes progressively smaller, and thus the cell surface area related to adhesion also becomes smaller. It was found that the number of basal cells per millimeter of basement membrane was closely related to the height of the columnar cell epithelium (r = 0.98), but not to the number of columnar cells (r = 0.42). The consistency of the relationship between increased columnar cell height (and thus decreased surface area for adhesion) and the number of basal cells present (r = 0.98) supports the concept that the basal cell plays a role in adhesion of columnar cells to the basement membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Microwave spectroscopy and curious molecular dynamics of ethyl trifluoroacetate

NASA Astrophysics Data System (ADS)

Bohn, Robert K.; Montgomery, John A.; Harvey Michels, H.; Acharte, Christian

2017-05-01

The first ethyl ester whose structure was determined by microwave spectroscopy is ethyl formate. It exists in two conformations. In the 1970s, that study was used as a model to determine the structures of other ethyl esters, ethyl cyanoformate, chloroformate, and trifluoroacetate. They display the same conformations as ethyl formate. But under the experimental conditions used, Stark modulation with a maximum electric field, static low pressure gas, rapid sweeping, and long detector time constants, each of those esters displays bands of an additional third species. A careful, high resolution study of ethyl cyanoformate only observed two conformers. A model has been proposed that the third species derives from a dense array of torsionally excited states with broadened transitions due to short lifetimes. The present study of ethyl trifluoroacetate in a pulsed jet Fourier Transform spectrometer is intended to clarify the earlier results. Two conformers are observed including all their monosubstituted 13C and 18O isotopologs. In a pulsed jet Fourier Transform spectrometer using argon as the carrier gas, only one conformer is observed. Switching to helium as the carrier gas, another, higher energy conformer is also observed.

Polyphenol fatty acid esters as serine protease inhibitors: a quantum-chemical QSAR analysis.

PubMed

Viskupicova, Jana; Danihelova, Martina; Majekova, Magdalena; Liptaj, Tibor; Sturdik, Ernest

2012-12-01

We investigated the ability of polyphenol fatty acid esters to inhibit the activity of serine proteases trypsin, thrombin, elastase and urokinase. Potent protease inhibition in micromolar range was displayed by rutin and rutin derivatives esterified with medium and long chain, mono- and polyunsaturated fatty acids (1e-m), followed by phloridzin and esculin esters with medium and long fatty acid chain length (2a-d, 3a-d), while unmodified compounds showed only little or no effect. QSAR study of the compounds tested provided the most significant parameters for individual inhibition activities, i.e. number of hydrogen bond donors for urokinase, molecular volume for thrombin, and solvation energy for elastase. According to the statistical analysis, the action of elastase inhibitors is opposed to those of urokinase and thrombin. Cluster analysis showed two groups of compounds: original polyphenols together with rutin esters with short fatty acid chain length and rutin esters with long fatty acid chain length.

Naturally Occurring Cinnamic Acid Sugar Ester Derivatives.

PubMed

Tian, Yuxin; Liu, Weirui; Lu, Yi; Wang, Yan; Chen, Xiaoyi; Bai, Shaojuan; Zhao, Yicheng; He, Ting; Lao, Fengxue; Shang, Yinghui; Guo, Yu; She, Gaimei

2016-10-24

Cinnamic acid sugar ester derivatives (CASEDs) are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3',6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM), presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae . This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

Comparative analysis of the Flavobacterium columnare genomovar I and II genomes

USDA-ARS?s Scientific Manuscript database

Columnaris disease caused by Gram-negative rod Flavobacterium columnare is one of the most common diseases of catfish. F. columnare is also a common problem in other cultured fish species worldwide. F. columnare has three major genomovars; we have sequenced a representative strain from genomovar I (...

Influence of Grape Composition on Red Wine Ester Profile: Comparison between Cabernet Sauvignon and Shiraz Cultivars from Australian Warm Climate.

PubMed

Antalick, Guillaume; Šuklje, Katja; Blackman, John W; Meeks, Campbell; Deloire, Alain; Schmidtke, Leigh M

2015-05-13

The relationship between grape composition and subsequent red wine ester profile was examined. Cabernet Sauvignon and Shiraz, from the same Australian very warm climate vineyard, were harvested at two different stages of maturity and triplicate wines were vinified. Grape analyses focused on nitrogen and lipid composition by measuring 18 amino acids by HPLC-FLD, 3 polyunsaturated fatty acids, and 6 C6-compounds derived from lipid degradation by GC-MS. Twenty esters and four higher alcohols were analyzed in wines by HS-SPME-GC-MS. Concentrations of the ethyl esters of branched acids were significantly affected by grape maturity, but the variations were inconsistent between cultivars. Small relative variations were observed between wines for ethyl esters of fatty acids, whereas higher alcohol acetates displayed the most obvious differences with concentrations ranging from 1.5- to 26-fold higher in Shiraz than in Cabernet Sauvignon wines regardless of the grape maturity. Grape analyses revealed the variations of wine ester composition might be related to specific grape juice nitrogen composition and lipid metabolism. To the authors' knowledge the present study is the first to investigate varietal differences in the ester profiles of Shiraz and Cabernet Sauvignon wines made with grapes harvested at different maturity stages.

Other factors to consider in the formation of chloropropandiol fatty esters in oil processes.

PubMed

Ramli, Muhamad Roddy; Siew, Wai Lin; Ibrahim, Nuzul Amri; Kuntom, Ainie; Abd Razak, Raznim Arni

2015-01-01

This paper examines the processing steps of extracting palm oil from fresh fruit bunches in a way that may impact on the formation of chloropropandiol fatty esters (3-MCPD esters), particularly during refining. Diacylglycerols (DAGs) do not appear to be a critical factor when crude palm oils are extracted from various qualities of fruit bunches. Highly hydrolysed oils, in spite of the high free fatty acid (FFA) contents, did not show exceptionally high DAGs, and the oils did not display a higher formation of 3-MCPD esters upon heat treatment. However, acidity measured in terms of pH appears to have a strong impact on 3-MCPD ester formation in the crude oil when heated at high temperatures. The differences in the extraction process of crude palm oil from current commercial processes and that from a modified experimental process showed clearly the effect of acidity of the oil on the formation of 3-MCPD esters. This paper concludes that the washing or dilution step in palm oil mills removes the acidity of the vegetative materials and that a well-optimised dilution/washing step in the extraction process will play an important role in reducing formation of 3-MCPD esters in crude palm oil upon further heat processing.

The Role of Electrolyte Upon the SEI Formation Characteristics and Low Temperature Performance of Lithium-Ion Cells With Graphite Anodes

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Greenbaum, S.; Surampudi, S.

2000-01-01

Quarternary lithium-ion battery electrolyte solutions containing ester co-solvents in mixtures of carbonates have been demonstrated to have high conductivity at low temperatures (< -20C). However, in some cases the presence of such co-solvents does not directly translate into improved low temperature cell performance, presumably due to the formation of ionically resistive surface films on carbonaceous anodes. In order to understand this behavior, a number of lithium-graphite cells have been studied containing electrolytes with various ester co-solvents, including methyl acetate (MA), ethyl acetate (EA), ethyl propionate (EP), and ethyl butyrate (EB). The charge/discharge characterization of these cells indicates that the higher molecular weight esters result in electrolytes which possess superior low temperature performance in contrast to the lower molecular weight ester-containing solutions, even though these solutions display lower conductivity values.

Rational selection of non-Saccharomyces wine yeasts for mixed starters based on ester formation and enological traits.

PubMed

Viana, Fernando; Gil, José V; Genovés, Salvador; Vallés, Salvador; Manzanares, Paloma

2008-09-01

Thirty-eight yeast strains belonging to the genera Candida, Hanseniaspora, Pichia, Torulaspora and Zygosaccharomyces were screened for ester formation on synthetic microbiological medium. The genera Hanseniaspora and Pichia stood out as the best acetate ester producers. Based on the ester profile Hanseniaspora guilliermondii 11027 and 11102, Hanseniaspora osmophila 1471 and Pichia membranifaciens 10113 and 10550 were selected for further characterization of enological traits. When growing on must H. osmophila 1471, which displayed a glucophilic nature and was able to consume more than 90% of initial must sugars, produced levels of acetic acid, medium chain fatty acids and ethyl acetate, within the ranges described for wine. On the other hand, it was found to be a strong producer of 2-phenylethyl acetate. Our data suggest that H. osmophila 1471 is a good candidate for mixed starters, although the possible interactions with S. cerevisiae deserve further research.

Synthesis and biological evaluation of arctigenin ester and ether derivatives as activators of AMPK.

PubMed

Shen, Sida; Zhuang, Jingjing; Chen, Yijia; Lei, Min; Chen, Jing; Shen, Xu; Hu, Lihong

2013-07-01

A series of new arctigenin and 9-deoxy-arctigenin derivatives bearing different ester and ether side chains at the phenolic hydroxyl positions are designed, synthesized, and evaluated for activating AMPK potency in L6 myoblasts. Initial biological evaluation indicates that some alkyl ester and phenethyl ether arctigenin derivatives display potential activities in AMPK phosphorylation improvement. Further structure-activity relationship analysis shows that arctigenin ester derivatives 3a, 3h and 9-deoxy-arctigenin phenethyl ether derivatives 6a, 6c, 6d activate AMPK more potently than arctigenin. Moreover, the 2-(3,4-dimethoxyphenyl)ethyl ether moiety of 6c has been demonstrated as a potential functional group to improve the effect of AMPK phosphorylation. The structural optimization of arctigenin leads to the identification of 6c as a promising lead compound that exhibits excellent activity in AMPK activation. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Yield surface evolution for columnar ice

NASA Astrophysics Data System (ADS)

Zhou, Zhiwei; Ma, Wei; Zhang, Shujuan; Mu, Yanhu; Zhao, Shunpin; Li, Guoyu

A series of triaxial compression tests, which has capable of measuring the volumetric strain of the sample, were conducted on columnar ice. A new testing approach of probing the experimental yield surface was performed from a single sample in order to investigate yield and hardening behaviors of the columnar ice under complex stress states. Based on the characteristic of the volumetric strain, a new method of defined the multiaxial yield strengths of the columnar ice is proposed. The experimental yield surface remains elliptical shape in the stress space of effective stress versus mean stress. The effect of temperature, loading rate and loading path in the initial yield surface and deformation properties of the columnar ice were also studied. Subsequent yield surfaces of the columnar ice have been explored by using uniaxial and hydrostatic paths. The evolution of the subsequent yield surface exhibits significant path-dependent characteristics. The multiaxial hardening law of the columnar ice was established experimentally. A phenomenological yield criterion was presented for multiaxial yield and hardening behaviors of the columnar ice. The comparisons between the theoretical and measured results indicate that this current model is capable of giving a reasonable prediction for the multiaxial yield and post-yield properties of the columnar ice subjected to different temperature, loading rate and path conditions.

Non-equlibrium relaxation of vortex lines in disordered type-II superconductors

NASA Astrophysics Data System (ADS)

Dobramysl, Ulrich; Assi, Hiba; Pleimling, Michel; T&äUber, Uwe C.

2013-03-01

Vortex matter in disordered type-II superconductors display a remarkable wealth of behavior, ranging from hexagonally arranged crystals and a vortex liquid to glassy phases. The type and strength of the disorder has a profound influence on the structural properties of the vortex matter: Randomly distributed weak point pinning sites lead to the destruction of long range order and a Bragg glass phase; correlated, columnar disorder can yield a Bose glass phase with infinite tilt modulus. We employ a three-dimensional elastic line model and apply a Langevin molecular dynamics algorithm to simulate the dynamics of vortex lines in a dissipative medium. We investigate the relaxation of a system of lines that were initially prepared in an out-of-equilibrium state and characterize the transient behavior via two-time quantities. We vary the disorder type and strength and compare our results for random and columnar disorder. Research supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award DE-FG02-09ER46613.

Residual stress in obliquely deposited MgF2 thin films.

PubMed

Jaing, Cheng-Chung; Liu, Ming-Chung; Lee, Cheng-Chung; Cho, Wen-Hao; Shen, Wei-Ting; Tang, Chien-Jen; Liao, Bo-Huei

2008-05-01

MgF(2) films with a columnar microstructure are obliquely deposited on glass substrates by resistive heating evaporation. The columnar angles of the films increases with the deposition angle. Anisotropic stress does not develop in the films with tilted columns. The residual stresses in the films depend on the deposition and columnar angles in a columnar microstructure.

Columnar metaplasia in a surgical mouse model of gastro-esophageal reflux disease is not derived from bone marrow-derived cell.

PubMed

Aikou, Susumu; Aida, Junko; Takubo, Kaiyo; Yamagata, Yukinori; Seto, Yasuyuki; Kaminishi, Michio; Nomura, Sachiyo

2013-09-01

The incidence of esophageal adenocarcinoma has increased in the last 25 years. Columnar metaplasia in Barrett's mucosa is assumed to be a precancerous lesion for esophageal adenocarcinoma. However, the induction process of Barrett's mucosa is still unknown. To analyze the induction of esophageal columnar metaplasia, we established a mouse gastro-esophageal reflux disease (GERD) model with associated development of columnar metaplasia in the esophagus. C57BL/6 mice received side-to-side anastomosis of the esophagogastric junction with the jejunum, and mice were killed 10, 20, and 40 weeks after operation. To analyze the contribution of bone marrow-derived cells to columnar metaplasia in this surgical GERD model, some mice were transplanted with GFP-marked bone marrow after the operation. Seventy-three percent of the mice (16/22) showed thickened mucosa in esophagus and 41% of mice (9/22) developed columnar metaplasia 40 weeks after the operation with a mortality rate of 4%. Bone marrow-derived cells were not detected in columnar metaplastic epithelia. However, scattered epithelial cells in the thickened squamous epithelia in regions of esophagitis did show bone marrow derivation. The results demonstrate that reflux induced by esophago-jejunostomy in mice leads to the development of columnar metaplasia in the esophagus. However, bone marrow-derived cells do not contribute directly to columnar metaplasia in this mouse model. © 2013 Japanese Cancer Association.

Evaluation of the hormonal state of columnar apple trees (Malus x domestica) based on high throughput gene expression studies.

PubMed

Krost, Clemens; Petersen, Romina; Lokan, Stefanie; Brauksiepe, Bastienne; Braun, Peter; Schmidt, Erwin R

2013-02-01

The columnar phenotype of apple trees (Malus x domestica) is characterized by a compact growth habit with fruit spurs instead of lateral branches. These properties provide significant economic advantages by enabling high density plantings. The columnar growth results from the presence of a dominant allele of the gene Columnar (Co) located on chromosome 10 which can appear in a heterozygous (Co/co) or homozygous (Co/Co) state. Although two deep sequencing approaches could shed some light on the transcriptome of columnar shoot apical meristems (SAMs), the molecular mechanisms of columnar growth are not yet elaborated. Since the influence of phytohormones is believed to have a pivotal role in the establishment of the phenotype, we performed RNA-Seq experiments to study genes associated with hormone homeostasis and clearly affected by the presence of Co. Our results provide a molecular explanation for earlier findings on the hormonal state of columnar apple trees. Additionally, they allow hypotheses on how the columnar phenotype might develop. Furthermore, we show a statistically approved enrichment of differentially regulated genes on chromosome 10 in the course of validating RNA-Seq results using additional gene expression studies.

Thermal expansion coefficients of obliquely deposited MgF2 thin films and their intrinsic stress.

PubMed

Jaing, Cheng-Chung

2011-03-20

This study elucidates the effects of columnar angles and deposition angles on the thermal expansion coefficients and intrinsic stress behaviors of MgF2 films with columnar microstructures. The behaviors associated with temperature-dependent stresses in the MgF2 films are measured using a phase-shifting Twyman-Green interferometer with a heating stage and the application of a phase reduction algorithm. The thermal expansion coefficients of MgF2 films at various columnar angles were larger than those of glass substrates. The intrinsic stress in the MgF2 films with columnar microstructures was compressive, while the thermal stress was tensile. The thermal expansion coefficients of MgF2 films with columnar microstructures and their intrinsic stress evidently depended on the deposition angle and the columnar angle.

Incorporation of fragmentation into a volume average solidification model

NASA Astrophysics Data System (ADS)

Zheng, Y.; Wu, M.; Kharicha, A.; Ludwig, A.

2018-01-01

In this study, a volume average solidification model was extended to consider fragmentation as a source of equiaxed crystals during mixed columnar-equiaxed solidification. The formulation suggested for fragmentation is based on two hypotheses: the solute-driven remelting is the dominant mechanism; and the transport of solute-enriched melt through an interdendritic flow in the columnar growth direction is favorable for solute-driven remelting and is the necessary condition for fragment transportation. Furthermore, a test case with Sn-10 wt%Pb melt solidifying vertically downward in a 2D domain (50 × 60 mm2) was calculated to demonstrate the model’s features. Solidification started from the top boundary, and a columnar structure developed initially with its tip growing downward. Furthermore, thermo-solutal convection led to fragmentation in the mushy zone near the columnar tip front. The fragments transported out of the columnar region continued to grow and sink, and finally settled down and piled up in the bottom domain. The growing columnar structure from the top and pile-up of equiaxed crystals from the bottom finally led to a mixed columnar-equiaxed structure, in turn leading to a columnar-to-equiaxed transition (CET). A special macrosegregation pattern was also predicted, in which negative segregation occurred in both columnar and equiaxed regions and a relatively strong positive segregation occurred in the middle domain near the CET line. A parameter study was performed to verify the model capability, and the uncertainty of the model assumption and parameter was discussed.

Environmentally Friendly Procedure Based on Supercritical Fluid Chromatography and Tandem Mass Spectrometry Molecular Networking for the Discovery of Potent Antiviral Compounds from Euphorbia semiperfoliata.

PubMed

Nothias, Louis-Félix; Boutet-Mercey, Stéphanie; Cachet, Xavier; De La Torre, Erick; Laboureur, Laurent; Gallard, Jean-François; Retailleau, Pascal; Brunelle, Alain; Dorrestein, Pieter C; Costa, Jean; Bedoya, Luis M; Roussi, Fanny; Leyssen, Pieter; Alcami, José; Paolini, Julien; Litaudon, Marc; Touboul, David

2017-10-27

A supercritical fluid chromatography-based targeted purification procedure using tandem mass spectrometry and molecular networking was developed to analyze, annotate, and isolate secondary metabolites from complex plant extract mixture. This approach was applied for the targeted isolation of new antiviral diterpene esters from Euphorbia semiperfoliata whole plant extract. The analysis of bioactive fractions revealed that unknown diterpene esters, including jatrophane esters and phorbol esters, were present in the samples. The purification procedure using semipreparative supercritical fluid chromatography led to the isolation and identification of two new jatrophane esters (13 and 14) and one known (15) and three new 4-deoxyphorbol esters (16-18). The structure and absolute configuration of compound 16 were confirmed by X-ray crystallography. This compound was found to display antiviral activity against Chikungunya virus (EC 50 = 0.45 μM), while compound 15 proved to be a potent and selective inhibitor of HIV-1 replication in a recombinant virus assay (EC 50 = 13 nM). This study showed that a supercritical fluid chromatography-based protocol and molecular networking can facilitate and accelerate the discovery of bioactive small molecules by targeting molecules of interest, while minimizing the use of toxic solvents.

Liquid Crystalline Thermosets from Ester, Ester-Imide, and Ester-Amide Oligomers

NASA Technical Reports Server (NTRS)

Dingemans, Theodornus J. (Inventor); Weiser, Erik S. (Inventor); SaintClair, Terry L. (Inventor)

2005-01-01

Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,OOO grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end- capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

Thermal properties and nanodispersion behavior of synthesized β-sitosteryl acyl esters: a structure-activity relationship study.

PubMed

Panpipat, Worawan; Dong, Mingdong; Xu, Xuebing; Guo, Zheng

2013-10-01

The efficiency (dose response) of cholesterol-lowering effect of phytosterols in humans depends on their chemical forms (derived or non-derived) and formulation methods in a delivery system. With a series of synthesized β-sitosteryl fatty acid esters (C2:0-C18:0 and C18:1-C18:3), this work examined their thermal properties and applications in preparation of nanodispersion with β-sitosterol as a comparison. Inspection of the melting point (Tm) and the heat of fusion (ΔH) of β-sitosteryl fatty acid esters and the chain length and unsaturation degree of fatty acyl moiety revealed a pronounced structure-property relationship. The nanodispersions prepared with β-sitosterol and β-sitosteryl saturated fatty acid (SFA) esters displayed different particle size distribution patterns (polymodal vs bimodal), mean diameter (115 nm vs less than 100 nm), and polydispersity index (PDI) (0.50 vs 0.23-0.38). β-sitosteryl unsaturated fatty acid (USFA) esters showed a distinctly different dispersion behavior to form nanoemulsions, rather than nanodispersions, with more homogeneous particle size distribution (monomodal, mean diameter 27-63 nm and PDI 0.18-0.25). The nanodispersion of β-sitosteryl medium chain SFA ester (C14:0) demonstrated a best storage stability. Copyright © 2013 Elsevier Inc. All rights reserved.

Liquid crystalline thermosets from ester, ester-imide, and ester-amide oligomers

NASA Technical Reports Server (NTRS)

Dingemans, Theodorous J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

2005-01-01

Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end-capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

Discovery of columnar jointing on Mars

USGS Publications Warehouse

Milazzo, M.P.; Keszthelyi, L.P.; Jaeger, W.L.; Rosiek, M.; Mattson, S.; Verba, C.; Beyer, R.A.; Geissler, P.E.; McEwen, A.S.

2009-01-01

We report on the discovery of columnar jointing in Marte Valles, Mars. These columnar lavas were discovered in the wall of a pristine, 16-km-diameter impact crater and exhibit the features of terrestrial columnar basalts. There are discontinuous outcrops along the entire crater wall, suggesting that the columnar rocks covered a surface area of at least 200 km2, assuming that the rocks obliterated by the impact event were similarly jointed. We also see columns in the walls of other fresh craters in the nearby volcanic plains of Elysium Planitia-Amazonis Planitia, which include Marte Vallis, and in a well-preserved crater in northeast Hellas. ?? 2009 The Geological Society of America.

The discovery of columnar jointing on Mars

USGS Publications Warehouse

Milazzo, M.P.; Keszthelyi, L.P.; Jaeger, W.L.; Rosiek, M.; Mattson, S.; Verba, C.; Beyer, R.A.; Geissler, P.E.; McEwen, A.S.; ,

2009-01-01

We report on the discovery of columnar jointing in Marte Valles, Mars. These columnar lavas were discovered in the wall of a pristine, 16-km-diameter impact crater and exhibit the features of terrestrial columnar basalts. There are discontinuous outcrops along the entire crater wall, suggesting that the columnar rocks covered a surface area of at least 200 km2, assuming that the rocks obliterated by the impact event were similarly jointed. We also see columns in the walls of other fresh craters in the nearby volcanic plains of Elysium Planitia–Amazonis Planitia, which include Marte Vallis, and in a well-preserved crater in northeast Hellas.

Estimation of dark and active dielectric constants in the sub-THz frequency domain of an optically tunable organic semiconductor blend of poly(3-hexylthiophene) and phenyl-C61-butyric acid methyl ester

NASA Astrophysics Data System (ADS)

Andy, Andre S.; Kneller, James W. E.; Sushko, Oleksandr; Dubrovka, Rostyslav; Parini, Clive; Scott, Ken; Kreouzis, Theo; Donnan, Robert S.

2018-06-01

The dielectric properties of a 95% poly(3-hexylthiophene):5% phenyl-C61-butyric acid methyl ester blend are measured in the dark and under white light illumination by quasi-optical transmissometry and terahertz time-domain spectroscopy. The real part of the dielectric constant varies monotonically between 2.75 and 3.50, in agreement with the literature, and displays a reversible photoinduced drop of 0.05–0.55 at sub-THz. The imaginary part fluctuates between 0.1 and 1.5 in the dark and displays a reversible increase upon illumination of 0.10–0.52 at sub-THz. The corresponding charge carrier concentration under illumination (using transient and steady-state photoconduction) is 1014 to 1015 cm‑3.

Digital mammography: more microcalcifications, more columnar cell lesions without atypia.

PubMed

Verschuur-Maes, Anoek H J; van Gils, Carla H; van den Bosch, Maurice A A J; De Bruin, Peter C; van Diest, Paul J

2011-09-01

The incidence of columnar cell lesions in breast core needle biopsies since full-field digital mammography in comparison with screen-filmed mammography was analyzed. As tiny microcalcifications characterize columnar cell lesions at mammography, we hypothesized that more columnar cell lesions are diagnosed since full-field digital mammography due to its higher sensitivity for microcalcifications. In all, 3437 breast core needle biopsies performed in three hospitals and resulting from in total 55 159 mammographies were revised: 1424 taken in the screen-filmed mammography and 2013 in the full-field digital mammography period. Between the screen-filmed mammography and full-field digital mammography periods, we compared the proportion of mammographies that led to core needle biopsies, the mammographic indication for core needle biopsies (density, microcalcifications, or both) and the proportion of columnar cell lesions with or without atypia. The columnar cell lesions were graded according to Schnitt, and we included atypical ductal hyperplasia arising in the context of columnar cell lesions. Proportions were compared using χ(2) tests and prevalence ratios were adjusted for age and hospital. We found that more core needle biopsies per mammogram were taken in the full-field digital mammography period (7.6%) compared with the screen-filmed mammography period (5.0%, P<0.0001). Microcalcifications were more often diagnosed with full-field digital mammography than with screen-filmed mammography (adjusted prevalence ratio: 1.14, confidence interval 95%: 1.01-1.28). Core needle biopsies from the full-field digital mammography era showed more columnar cell lesions (10.8%) than those from the screen-filmed mammography era (4.9%; adjusted prevalence ratio: 1.93, confidence interval 95%: 1.48-2.51), particularly due to more columnar cell lesions without atypia (8.2% respectively 2.8%) while the proportion of columnar cell lesions with atypia remained nearly constant (2.0 vs 2.6%). In conclusion, since the implementation of full-field digital mammography, more microcalcifications are seen at mammography, more often resulting in core needle biopsies, which especially yields more columnar cell lesions without atypia.

Columnar joint morphology and cooling rate: A starch-water mixture experiment

NASA Astrophysics Data System (ADS)

Toramaru, A.; Matsumoto, T.

2004-02-01

An analogue experiment using a starch-water mixture has been carried out in order to understand the effect of cooling rate on the morphological characteristics of a basalt columnar joint. If the contraction of material is essential for the formation of columnar joint structure, the water loss rate by desiccation (hereafter referred to as desiccation rate) in the experiment is analogous to the cooling rate in solidifying basalt. In the experiment the desiccation rate is controlled by varying the distance between the starch-water mixture and a lamp used as the heat source. We find that there are three regimes in the relation between joint formation and desiccation rate: (1) At desiccation rates higher than ˜1.4 × 10-2 (g cm-2 h-1) (normal columnar joint regime), the average cross-sectional area S of a column is inversely proportional to the average desiccation rate, (i.e., S ∝ -δ, with δ = 1). (2) Between that desiccation rate and a critical desiccation rate, 0.8 × 10-2 (g/cm2h), S approaches infinity as decreases close to a critical desiccation rate (i.e., exponent δ monotonically increases from unity to infinity) (critical regime). (3) Below the critical desiccation rate, no columnar structure forms (no columnar joint regime forms). Applying the present experimental result to the formation of basalt column, the basalt columnar cross-sectional area is inversely proportional to the cooling rate with factors including elasticity, crack growth coefficient, thermal expansion, glass transition temperature, and crack density ratio at stress maximum. Also, it can be predicted that there exists a critical cooling rate below which the columnar joint does not form; the presence of a critical regime between the normal columnar jointing and no columnar jointing during a certain cooling rate range can also be predicted. We find that at higher cooling rate the preferred column shape is a pentagon, whereas at lower cooling rate it is a hexagon.

Morphology of the epithelium of the lower rectum and the anal canal in the adult human.

PubMed

Tanaka, Eiichi; Noguchi, Tsuyoshi; Nagai, Kaoruko; Akashi, Yuichi; Kawahara, Katsunobu; Shimada, Tatsuo

2012-06-01

The anal canal is an important body part clinically. However, there is no agreement about the epithelium of the anal canal, the anal transitional zone (ATZ) epithelium in particular. The aim of this study is to clarify the structure of the epithelium of the human lower rectum and anal canal. Intact rectum and anus obtained from patients who underwent surgery for rectal carcinoma were examined by light and scanning electron microscopy (LM and SEM). By LM, three types of epithelium were observed in the anal canal: simple columnar epithelium, stratified squamous epithelium, and stratified columnar epithelium. The lower rectum was composed of simple columnar epithelium. SEM findings showed stratified squamous epithelium that consisted of squamous cells with microridges, changing to simple columnar epithelium consisting of columnar cells with short microvilli at the anorectal line. LM and SEM observations in a one-to-one ratio revealed that the area of stratified columnar epithelium based on LM corresponded to the anal crypt and sinus. In conclusion, the epithelium of the human anal canal was fundamentally composed of simple columnar epithelium and stratified squamous epithelium. We found no evidence of the ATZ.

Columnar to Nematic Mesophase Transition: Binary Mixtures of Copper Soaps with Hydrocarbons

NASA Astrophysics Data System (ADS)

Seghrouchni, R.; Skoulios, A.

1995-09-01

Copper (II) soaps are known to produce columnar mesophases at high temperatures. The polar groups of the soap molecules are stacked over one another within columns surrounded by the paraffin chains in a disordered conformation and laterally arranged according to a two-dimensional hexagonal lattice. Upon addition of a hydrocarbon, the mesophases swell homogeneously. The hydrocarbon molecules locate themselves among the disordered chains of the soap molecules, the columnar cores remain perfectly unchanged, keeping a constant intra-columnar stacking period, and the hexagonal lattice expands in proportion to the amount of hydrocarbon added to the system. Beyond a certain degree of swelling, the columnar mesophases suddenly turn into a nematic mesophase through a first-order phase transition. The structural elements that align parallel to the nematic director are the very same molecular columns that are involved in the columnar mesophases. The columnar to nematic mesophase transition was studied systematically as a function of the molecular size of the soaps and hydrocarbons used as diluents and discussed on a molecular level, emphasizing such aspects as the persistence length of the paraffin chains and the location of the solvent molecules among the columns.

Enhancing the Efficiency of Bulk Heterojunction Solar Cells via Templated Self Assembly

NASA Astrophysics Data System (ADS)

Pan, Cheng; Li, Hongfei; Akgun, Bulent; Satijia, Sushil; Gersappe, Dilip; Zhu, Yimei; Rafailovich, Miriam

2013-03-01

Bulk Heterojunction (BHJ) polymer solar cells are an area of intense interest due to their flexibility and relatively low cost. The mixture of polythiophene derivatives (donor) and fullerenes (acceptor) is spin coated on substrate as the active layer, and are phase-separated into interconnected domains. However, due to the disordered inner structures in the active layer, donor or acceptor domains isolated from electrodes and long path conduction, the power conversion efficiency (PCE) of BHJ solar cell is low. Therefore, morphology control in bulk heterojunction (BHJ) solar cell is considered to be critical for the power conversion efficiency (PCE). Here, we present a novel approach that introduces non-photoactive polymer that organizes the poly(3-hexylthiophene) (P3HT) into columnar phases decorated by [6,6]-phenyl C61-butyric acid methyl ester (PCBM) at the interface. This structure represents a realization of an idealized morphology of an organic solar cell, in which, both exiciton dissociation and the carrier transport are optimized leading to increased power conversion efficiency.

Fish mucus alters the Flavobacterium columnare transcriptome

USDA-ARS?s Scientific Manuscript database

Columnaris disease which is caused by Flavobacterium columnare severely impacts the production of freshwater finfish species. Due to the impact on the aquaculture industry, research efforts to better understand the biological processes of F. columnare including the formation of biofilms and their co...

Tetrahedral Arrangements of Perylene Bisimide Columns via Supramolecular Orientational Memory.

PubMed

Sahoo, Dipankar; Peterca, Mihai; Aqad, Emad; Partridge, Benjamin E; Heiney, Paul A; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Percec, Virgil

2017-01-24

Chiral, shape, and liquid crystalline memory effects are well-known to produce commercial macroscopic materials with important applications as springs, sensors, displays, and memory devices. A supramolecular orientational memory effect that provides complex nanoscale arrangements was only recently reported. This supramolecular orientational memory was demonstrated to preserve the molecular orientation and packing within supramolecular units of a self-assembling cyclotriveratrylene crown at the nanoscale upon transition between its columnar hexagonal and Pm3̅n cubic periodic arrays. Here we report the discovery of supramolecular orientational memory in a dendronized perylene bisimide (G2-PBI) that self-assembles into tetrameric crowns and subsequently self-organizes into supramolecular columns and spheres. This supramolecular orientation memory upon transition between columnar hexagonal and body-centered cubic (BCC) mesophases preserves the 3-fold cubic [111] orientations rather than the 4-fold [100] axes, generating an unusual tetrahedral arrangement of supramolecular columns. These results indicate that the supramolecular orientational memory concept may be general for periodic arrays of self-assembling dendrons and dendrimers as well as for other periodic and quasiperiodic nanoscale organizations comprising supramolecular spheres, generated from other organized complex soft matter including block copolymers and surfactants.

Cytological lesions in the midgut of Tribolium confusum larvae exposed to gamma radiation

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

Jafri, R.H.; Ismail, M.

1977-01-01

The major cytological lesions in Tribolium confusum after irradiation were displayed by the midgut epithelium. At 24 hr following exposure to 5.3 kR, the regenerative cells called nidi appeared numerous. They gradually disappeared with increases in dosage and time in accordance with Arndt-Schulze's Law. The columnar epithelial cells and their nuclei appeared swollen and vacuolated on the fifth and twelfth day following exposure to 5.3 kR. They appeared disorganized and shed into the lumen of the midgut on the twelfth and fifth day following 50- and 70-kR irradiation, respectively. The basement membrane and the muscularis appeared loose on the fifthmore » and twelfth day dollowing 70-kR irradiation. It was observed that once the catabolic activity, i.e., histolysis, was initiated in the midgut, it continued to accelerate with increasing dose and time. Thus, the last effects at low doses, 5.3 and 10 kR, appeared as immediate effects at high doses, 50 and 70 kR. The differentiated cells, i.e., columnar epithelial cells, appeared radioresistant as compared to undifferentiated cells, i.e., regenerative cells, which appeared radiosensitive in accordance with the principle of Bergonie and Tribondeau.« less

A statistical model to predict total column ozone in Peninsular Malaysia

NASA Astrophysics Data System (ADS)

Tan, K. C.; Lim, H. S.; Mat Jafri, M. Z.

2016-03-01

This study aims to predict monthly columnar ozone in Peninsular Malaysia based on concentrations of several atmospheric gases. Data pertaining to five atmospheric gases (CO2, O3, CH4, NO2, and H2O vapor) were retrieved by satellite scanning imaging absorption spectrometry for atmospheric chartography from 2003 to 2008 and used to develop a model to predict columnar ozone in Peninsular Malaysia. Analyses of the northeast monsoon (NEM) and the southwest monsoon (SWM) seasons were conducted separately. Based on the Pearson correlation matrices, columnar ozone was negatively correlated with H2O vapor but positively correlated with CO2 and NO2 during both the NEM and SWM seasons from 2003 to 2008. This result was expected because NO2 is a precursor of ozone. Therefore, an increase in columnar ozone concentration is associated with an increase in NO2 but a decrease in H2O vapor. In the NEM season, columnar ozone was negatively correlated with H2O (-0.847), NO2 (0.754), and CO2 (0.477); columnar ozone was also negatively but weakly correlated with CH4 (-0.035). In the SWM season, columnar ozone was highly positively correlated with NO2 (0.855), CO2 (0.572), and CH4 (0.321) and also highly negatively correlated with H2O (-0.832). Both multiple regression and principal component analyses were used to predict the columnar ozone value in Peninsular Malaysia. We obtained the best-fitting regression equations for the columnar ozone data using four independent variables. Our results show approximately the same R value (≈ 0.83) for both the NEM and SWM seasons.

Spacer length controlled lamello-columnar to oblique-columnar mesophase transition in liquid crystalline DNA - discotic cationic lipid complexes

NASA Astrophysics Data System (ADS)

Zhu, Lei; Cui, Li; Miao, Jianjun

2006-03-01

A series of asymmetric triphenylene imidazolium salts with different spacer lengths (C5, C8, and C11) were synthesized and their ionic complexes with double-strand DNA were prepared in aqueous solution. The molecular composition of the complexes was determined by FTIR analysis. The liquid crystalline morphology was characterized by polarized light microscopy, X-ray diffraction (XRD), and transmission electron microscope. 2D XRD results indicated an oblique columnar phase for the complex with a short spacer length of C5, while lamello-columnar phases for those with longer spacer lengths (C8 and C11). Thin film circular dichroism results showed the disappearing of any helical conformation in the DNA in all the complexes. Instead, the complexation between single-strand RNA and discotic cationic lipids did not show columnar morphology; therefore, the columnar liquid crystalline morphology in the DNA-discotic cationic lipid complexes was attributed to the DNA double-strand chain rigidity.

Optical and structural properties of cobalt-permalloy slanted columnar heterostructure thin films

NASA Astrophysics Data System (ADS)

Sekora, Derek; Briley, Chad; Schubert, Mathias; Schubert, Eva

2017-11-01

Optical and structural properties of sequential Co-column-NiFe-column slanted columnar heterostructure thin films with an Al2O3 passivation coating are reported. Electron-beam evaporated glancing angle deposition is utilized to deposit the sequential multiple-material slanted columnar heterostructure thin films. Mueller matrix generalized spectroscopic ellipsometry data is analyzed with a best-match model approach employing the anisotropic Bruggeman effective medium approximation formalism to determine bulk-like and anisotropic optical and structural properties of the individual Co and NiFe slanted columnar material sub-layers. Scanning electron microscopy is applied to image the Co-NiFe sequential growth properties and to verify the results of the ellipsometric analysis. Comparisons to single-material slanted columnar thin films and optically bulk solid thin films are presented and discussed. We find that the optical and structural properties of each material sub-layer of the sequential slanted columnar heterostructure film are distinct from each other and resemble those of their respective single-material counterparts.

Disclosing the temperature of columnar jointing in lavas.

PubMed

Lamur, Anthony; Lavallée, Yan; Iddon, Fiona E; Hornby, Adrian J; Kendrick, Jackie E; von Aulock, Felix W; Wadsworth, Fabian B

2018-04-12

Columnar joints form by cracking during cooling-induced contraction of lava, allowing hydrothermal fluid circulation. A lack of direct observations of their formation has led to ambiguity about the temperature window of jointing and its impact on fluid flow. Here we develop a novel thermo-mechanical experiment to disclose the temperature of columnar jointing in lavas. Using basalts from Eyjafjallajökull volcano (Iceland) we show that contraction during cooling induces stress build-up below the solidus temperature (980 °C), resulting in localised macroscopic failure between 890 and 840 °C. This temperature window for incipient columnar jointing is supported by modelling informed by mechanical testing and thermal expansivity measurements. We demonstrate that columnar jointing takes place well within the solid state of volcanic rocks, and is followed by a nonlinear increase in system permeability of <9 orders of magnitude during cooling. Columnar jointing may promote advective cooling in magmatic-hydrothermal environments and fluid loss during geothermal drilling and thermal stimulation.

Microseismic monitoring of columnar jointed basalt fracture activity: a trial at the Baihetan Hydropower Station, China

NASA Astrophysics Data System (ADS)

Chen, Bing-Rui; Li, Qing-Peng; Feng, Xia-Ting; Xiao, Ya-Xun; Feng, Guang-Liang; Hu, Lian-Xing

2014-10-01

Severe stress release has occurred to the surrounding rocks of the typically columnar jointed basalt after excavation at the Baihetan Hydropower Station, Jinsha River, China, where cracking, collapse, and other types of failure may take place occasionally due to relaxation fracture. In order to understand the relaxation fracture characteristics of the columnar jointed basalt in the entire excavation process at the diversion tunnel of the Baihetan Hydropower Station, real-time microseismic monitoring tests were performed. First, the applicability of a geophone and accelerometer was analyzed in the columnar jointed basalt tunnel, and the results show that the accelerometer was more applicable to the cracking monitoring of the columnar jointed basalt. Next, the waveform characteristics of the microseismic signals were analyzed, and the microseismic signals were identified as follows: rock fracture signal, drilling signal, electrical signal, heavy vehicle passing signal, and blast signal. Then, the attenuation characteristics of the microseismic signals in the columnar jointed basalt tunnel were studied, as well as the types and characteristics of the columnar jointed basalt fracture. Finally, location analysis was conducted on the strong rock fracture events, in which four or more sensors were triggered, to obtain the temporal and spatial evolution characteristics and laws of the columnar jointed basalt relaxation fracture after excavation. The test results are not only of important reference value to the excavation and support of diversion tunnel at the Baihetan Hydropower Station, but also of great referential significance and value to the conduction of similar tests.

Isolation and characterization of Flavobacterium columnare strains infecting fishes inhabiting the Laurentian Great Lakes basin

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare, the etiological agent of columnaris disease, causes significant losses in fish worldwide. In this study, F. columnare infection prevalence was assessed in representative Great Lakes fish species. Over 2,000 wild, feral, and hatchery-propagated salmonids, percids, centrarc...

Phenotypic characterization and genetic diversity of Flavobacterium columnare isolated from red tilapia, Oreochromis sp. in Thailand

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare is the etiologic agent of columnaris disease and severely affects various freshwater aquaculture fish species worldwide. The objectives of this study were to determine the phenotypic characteristics and genetic variability among F. columnare isolates isolated from red tilapi...

VIRULENCE OF Flavobacterium columnare GENOMOVARS IN RAINBOW TROUT (Oncorhynchus mykiss)

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare is the causative agent of columnaris disease and is responsible for significant economic losses in aquaculture. F. columnare is a Gram-negative bacterium, and five genetic types or genomovars have been described based on restriction fragment length polymorphism of the 16S rR...

Identification of four distinct phylogenetic groups in Flavobacterium columnare with fish host associations

USDA-ARS?s Scientific Manuscript database

Columnaris disease, caused by the Gram-negative bacterium Flavobacterium columnare, is one of the most prevalent fish diseases worldwide. An exceptionally high level of genetic diversity among isolates of F. columnare has long been recognized, whereby six established genomovars have been described t...

Evaluation of potassium permanganate against an experimental subacute infection of Flavobacterium columnare in channel catfish, Icatlurus punctatus

USDA-ARS?s Scientific Manuscript database

The efficacy of potassium permanganate (KMnO4) as a prophylactic and therapeutic treatment for subacute infection of Flavobacterium columnare was demonstrated in experimentally infected channel catfish, Ictalurus punctatus. Catfish experimentally infected with F. columnare to mimic a subacute infec...

Submucosal glands in the columnar-lined oesophagus: evidence of an association with metaplasia and neosquamous epithelium.

PubMed

Lörinc, Ester; Öberg, Stefan

2012-07-01

A multipotential stem cell, possibly located in the submucosal gland ducts, has been suggested as the origin of metaplastic mucosa in the oesophagus. The topographic distribution of these glands and their excretory ducts (SMG) within the columnar lined oesophagus (CLO) is largely unknown. The aim of this study was to examine the distribution of SMG in relation to the type of overlying epithelium in patients with CLO. Seven oesophageal resection specimens were examined histologically in toto. The median frequency of SMG was similar in the metaplastic segments (0.12 SMG/mm) and the normal squamous segments (0.10 SMG/mm). Within the metaplastic segments, the median frequency of SMG beneath the squamous islands was significantly higher than that observed under the columnar lined parts (0.22 versus 0.08 SMG/mm, P = 0.046), There was a strong accumulation of SMG at the squamo-columnar transition zones (0.53 SMG/mm), which was significantly greater than that found in the columnar and squamous parts (P = 0.001 and 0.002, respectively). The relative accumulation of SMG beneath squamous islands and the squamo-columnar junctions within the metaplastic segment supports the hypothesis that both metaplastic columnar mucosa and neosquamous epithelium originate from a progenitor in the SMG. © 2012 Blackwell Publishing Ltd.

Colorimetric Method of Loop-Mediated Isothermal Amplification with the Pre-Addition of Calcein for Detecting Flavobacterium columnare and its Assessment in Tilapia Farms.

PubMed

Suebsing, Rungkarn; Kampeera, Jantana; Sirithammajak, Sarawut; Withyachumnarnkul, Boonsirm; Turner, Warren; Kiatpathomchai, Wansika

2015-03-01

Flavobacterium columnare, the causative agent of columnaris disease in fish, affects many economically important freshwater fish species. A colorimetric method of loop-mediated isothermal amplification with the pre-addition of calcein (LAMP-calcein) was developed and used to detect the presence of F. columnare in farmed tilapia (Nile Tilapia Oreochromis niloticus and red tilapia [Nile Tilapia × Mozambique Tilapia O. mossambicus]) and rearing water. The detection method, based on a change in color from orange to green, could be performed within 45 min at 63°C. The method was highly specific, as it had no cross-detections with 14 other bacterial species, including other fish pathogens and two Flavobacterium species. The method has a minimum detection limit of 2.2 × 10(2) F. columnare CFU; thus, it is about 10 times more sensitive than conventional PCR. With this method, F. columnare was detected in gonad, gill, and blood samples from apparently healthy tilapia broodstock as well as in samples of fertilized eggs, newly hatched fry, and rearing water. The bacteria isolated from the blood were further characterized biochemically and found to be phenotypically identical to F. columnare. The amplified products from the LAMP-calcein method had 97% homology with the DNA sequence of F. columnare.

Comparative challenge model of Flavobacterium columnare using abraded and unabraded channel catfish, Ictalurus punctatus (Rafinesque).

PubMed

Bader, J A; Nusbaum, K E; Shoemaker, C A

2003-08-01

The early entry of the fish pathogen Flavobacterium columnare and enhancement by abrasion was studied in channel catfish, Ictalurus punctatus (Rafinesque), using the polymerase chain reaction and a species-specific primer set for a bacterial 16S rRNA gene product. Evaluations were conducted following an abrasion bath immersion challenge with F. columnare. Abrasion, a practice which has historically been used prior to bacterial challenge, had significant effects on the early entry of the pathogen and on cumulative percent survival (CPS). The FvpF1-FvpR1 primer set was useful in detecting the early entry of F. columnare in mucus, skin, gill, blood, liver and trunk kidney tissues in both abraded and unabraded fish following immersion challenge at 29 +/- 2 degrees C. Bacteria were detected earlier in all tissues in abraded fish, except in the trunk kidney. These differences were not significant, except in the case of blood. Mucus, skin and gill tissues were positive for F. columnare earliest regardless of treatment (after 5 min in abraded fish and after 15 min in unabraded fish). CPS following challenge with F. columnare was significantly affected by abrasion, which supports the use of abrasion for the F. columnare challenge model for channel catfish.

Frictional and structural characterization of ion-nitrided low and high chromium steels

NASA Technical Reports Server (NTRS)

Spalvins, T.

1985-01-01

Low Cr steels AISI 41410, AISI 4340, and high Cr austenitic stainless steels AISI 304, AISI 316 were ion nitrided in a dc glow discharge plasma consisting of a 75 percent H2 - 25 percent N2 mixture. Surface compound layer phases were identified, and compound layer microhardness and diffusion zone microhardness profiles were established. Distinct differences in surface compound layer hardness and diffusion zone profiles were determined between the low and high Cr alloy steels. The high Cr stainless steels after ion nitriding displayed a hard compound layer and an abrupt diffusion zone. The compound layers of the high Cr stainless steels had a columnar structure which accounts for brittleness when layers are exposed to contact stresses. The ion nitrided surfaces of high and low Cr steels displayed a low coefficient of friction with respect to the untreated surfaces when examined in a pin and disk tribotester.

Esters of Quinoxaline 1ˏ4-Di-N-oxide with Cytotoxic Activity on Tumor Cell Lines Based on NCI-60 Panel

PubMed Central

Rivera, Gildardo; Ahmad Shah, Syed Shoaib; Arrieta-Baez, Daniel; Palos, Isidro; Mongue, Antonio; Sánchez-Torres, Luvia Enid

2017-01-01

Quinoxalines display diverse and interesting pharmacological activities as antibacterial, antiviral, antiparasitic and anticancer agents. Particularly, their 1ˏ4-di-N-oxide derivatives have proved to be cytotoxic agents that are active under hypoxic conditions as that of solid tumours. A new series of quinoxaline 1ˏ4-di-N-oxide substitutes at 7-position with esters group were synthetized and characterized by infrared (IR), proton nuclear magnetic resonance (1H-NMR), spectroscopy, and elemental analysis. Seventeen derivatives (M1-M3, E1-E8, P1-P3 and DR1-DR3) were selected and evaluated for antitumor activities using the NCI-60 human tumor cell lines screen. Results showed that E7, P3 and E6 were the most active compounds against the cell lines tested. Substitutions at 7-position with esters group not necessarily affect the biological activity, but the nature of the esters group could exert an influence on the selectivity. Additionally, substitutions at 2-position influenced the cytotoxic activity of the compounds. PMID:29201086

Esters of Quinoxaline 1`4-Di-N-oxide with Cytotoxic Activity on Tumor Cell Lines Based on NCI-60 Panel.

PubMed

Rivera, Gildardo; Ahmad Shah, Syed Shoaib; Arrieta-Baez, Daniel; Palos, Isidro; Mongue, Antonio; Sánchez-Torres, Luvia Enid

2017-01-01

Quinoxalines display diverse and interesting pharmacological activities as antibacterial, antiviral, antiparasitic and anticancer agents. Particularly, their 1`4-di- N -oxide derivatives have proved to be cytotoxic agents that are active under hypoxic conditions as that of solid tumours. A new series of quinoxaline 1`4-di- N -oxide substitutes at 7-position with esters group were synthetized and characterized by infrared (IR), proton nuclear magnetic resonance ( 1 H-NMR), spectroscopy, and elemental analysis. Seventeen derivatives (M1-M3, E1-E8, P1-P3 and DR1-DR3) were selected and evaluated for antitumor activities using the NCI-60 human tumor cell lines screen. Results showed that E7, P3 and E6 were the most active compounds against the cell lines tested. Substitutions at 7-position with esters group not necessarily affect the biological activity, but the nature of the esters group could exert an influence on the selectivity. Additionally, substitutions at 2-position influenced the cytotoxic activity of the compounds.

Lipophilization of ascorbic acid: a monolayer study and biological and antileishmanial activities.

PubMed

Kharrat, Nadia; Aissa, Imen; Sghaier, Manel; Bouaziz, Mohamed; Sellami, Mohamed; Laouini, Dhafer; Gargouri, Youssef

2014-09-17

Ascorbyl lipophilic derivatives (Asc-C2 to Asc-C(18:1)) were synthesized in a good yield using lipase from Staphylococcus xylosus produced in our laboratory and immobilized onto silica aerogel. Results showed that esterification had little effect on radical-scavenging capacity of purified ascorbyl esters using DPPH assay in ethanol. However, long chain fatty acid esters displayed higher protection of target lipids from oxidation. Moreover, compared to ascorbic acid, synthesized derivatives exhibited an antibacterial effect. Furthermore, ascorbyl derivatives were evaluated, for the first time, for their antileishmanial effects against visceral (Leishmania infantum) and cutaneous parasites (Leishmania major). Among all the tested compounds, only Asc-C10, Asc-C12, and Asc-C(18:1) exhibited antileishmanial activities. The interaction of ascorbyl esters with a phospholipid monolayer showed that only medium and unsaturated long chain (Asc-C10 to Asc-C(18:1)) derivative esters were found to interact efficiently with mimetic membrane of leishmania. These properties would make ascorbyl derivatives good candidates to be used in cosmetic and pharmaceutical lipophilic formulations.

Growing large columnar grains of CH3NH3PbI3 using the solid-state reaction method enhanced by less-crystallized nanoporous PbI2 films

NASA Astrophysics Data System (ADS)

Zheng, Huifeng; Wang, Weiqi; Liu, Yangqiao; Sun, Jing

2017-03-01

Compact, pinhole-free and PbI2-free perovskite films, are desirable for high-performance perovskite solar cells (PSCs), especially if large columnar grains are obtained in which the adverse effects of grain boundaries will be minimized. However, the conventional solid-state reaction methods, originated from the two-step method, failed to grow columnar grains of CH3NH3PbI3 in a facile way. Here, we demonstrate a strategy for growing large columnar grains of CH3NH3PbI3, by less-crystallized nanoporous PbI2 (ln-PbI2) film enhanced solid-state reaction method. We demonstrated columnar grains were obtainable only when ln-PbI2 films were applied. Therefore, the replacement of compact PbI2 by ln-PbI2 in the solid-sate reaction, leads to higher power conversion efficiency, better reproducibility, better stability and less hysteresis. Furthermore, by systematically investigating the effects of annealing temperature and duration, we found that an annealing temperature ≥120 °C was also critical for growing columnar grains. With the optimal process, a champion efficiency of 16.4% was obtained and the average efficiency reached 14.2%. Finally, the mechanism of growing columnar grains was investigated, in which a VPb″ -assisted hooping model was proposed. This work reveals the origins of grain growth in the solid-state reaction method, which will contribute to preparing high quality perovskite films with much larger columnar grains.

Isolation and Characterization of EstC, a New Cold-Active Esterase from Streptomyces coelicolor A3(2)

PubMed Central

Brault, Guillaume; Shareck, François; Hurtubise, Yves; Lépine, François; Doucet, Nicolas

2012-01-01

The genome sequence of Streptomyces coelicolor A3(2) contains more than 50 genes coding for putative lipolytic enzymes. Many studies have shown the capacity of this actinomycete to store important reserves of intracellular triacylglycerols in nutrient depletion situations. In the present study, we used genome mining of S. coelicolor to identify genes coding for putative, non-secreted esterases/lipases. Two genes were cloned and successfully overexpressed in E. coli as His-tagged fusion proteins. One of the recombinant enzymes, EstC, showed interesting cold-active esterase activity with a strong potential for the production of valuable esters. The purified enzyme displayed optimal activity at 35°C and was cold-active with retention of 25% relative activity at 10°C. Its optimal pH was 8.5–9 but the enzyme kept more than 75% of its maximal activity between pH 7.5 and 10. EstC also showed remarkable tolerance over a wide range of pH values, retaining almost full residual activity between pH 6–11. The enzyme was active toward short-chain p-nitrophenyl esters (C2–C12), displaying optimal activity with the valerate (C5) ester (k cat/K m = 737±77 s−1 mM−1). The enzyme was also very active toward short chain triglycerides such as triacetin (C2:0) and tributyrin (C4:0), in addition to showing good primary alcohol and organic solvent tolerance, suggesting it could function as an interesting candidate for organic synthesis of short-chain esters such as flavors. PMID:22396747

Flavobacterium columnare isolated from red tilapia (Oreochromis sp.): emphasis on genetic characterization and virulence of rhizoid and non-rhizoid morphotypes

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare is the causative agent of columnaris disease and severely affects various freshwater fish species worldwide. Here, we described the phenotypic and genetic characterization of F. columnare isolates isolated from farmed red tilapia in Thailand. Additionally, the virulence as w...

Complete genome sequence of the fish pathogen Flavobacterium columnare strain C#2

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare is a Gram-negative bacterial pathogen that causes columnaris disease of freshwater fish. Flavobacterium columnare strain C#2 was isolated from a diseased warm water fish and is typed as genomovar II. The genome consists of a single 3.33 Mb circular chromosome with 2,689 pred...

Evidence for regulation of columnar habit in apple by a putative 2OG-Fe(II) oxygenase.

PubMed

Wolters, Pieter J; Schouten, Henk J; Velasco, Riccardo; Si-Ammour, Azeddine; Baldi, Paolo

2013-12-01

Understanding the genetic mechanisms controlling columnar-type growth in the apple mutant 'Wijcik' will provide insights on how tree architecture and growth are regulated in fruit trees. In apple, columnar-type growth is controlled by a single major gene at the Columnar (Co) locus. By comparing the genomic sequence of the Co region of 'Wijcik' with its wild-type 'McIntosh', a novel non-coding DNA element of 1956 bp specific to Pyreae was found to be inserted in an intergenic region of 'Wijcik'. Expression analysis of selected genes located in the vicinity of the insertion revealed the upregulation of the MdCo31 gene encoding a putative 2OG-Fe(II) oxygenase in axillary buds of 'Wijcik'. Constitutive expression of MdCo31 in Arabidopsis thaliana resulted in compact plants with shortened floral internodes, a phenotype reminiscent of the one observed in columnar apple trees. We conclude that MdCo31 is a strong candidate gene for the control of columnar growth in 'Wijcik'. No claim to original European Union works. New Phytologist © 2013 New Phytologist Trust.

Mono- and tri-ester hydrogenolysis using tandem catalysis. Scope and mechanism.

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

Lohr, Tracy L.; Li, Zhi; Assary, Rajeev S.

The scope and mechanism of thermodynamically leveraged ester RC(O)O-R' bond hydrogenolysis by tandem metal triflate + supported Pd catalysts are investigated both experimentally and theoretically by DFT and energy span analysis. This catalytic system has a broad scope, with relative cleavage rates scaling as, tertiary 4 secondary 4 primary ester at 1 bar H-2, yielding alkanes and carboxylic acids with high conversion and selectivity. Benzylic and allylic esters display the highest activity. The rate law is nu = k[M(OTf )(n)](1)[ester](0)[H-2](0) with an H/D kinetic isotope effect = 6.5 +/- 0.5, implying turnover-limiting C-H scission following C-O cleavage, in agreement withmore » theory. Intermediate alkene products are then rapidly hydrogenated. Applying this approach with the very active Hf(OTf)(4) catalyst to bio-derived triglycerides affords near-quantitative yields of C-3 hydrocarbons rather than glycerol. From model substrates, it is found that RC(O)O-R' cleavage rates are very sensitive to steric congestion and metal triflate identity. For triglycerides, primary/external glyceryl CH2-O cleavage predominates over secondary/internal CH-O cleavage, with the latter favored by less acidic or smaller ionic radius metal triflates, raising the diester selectivity to as high as 48% with Ce(OTf)(3).« less

A new simple phthalimide-based fluorescent probe for highly selective cysteine and bioimaging for living cells

NASA Astrophysics Data System (ADS)

Shen, Youming; Zhang, Xiangyang; Zhang, Youyu; Zhang, Chunxiang; Jin, Junling; Li, Haitao

2017-10-01

A new turn-on phthalimide fluorescent probe has designed and synthesized for sensing cysteine (Cys) based on excited state intramolecular proton transfer (ESIPT) process. It is consisted of a 3-hydroxyphthalimide derivative moiety as the fluorophore and an acrylic ester group as a recognition receptor. The acrylic ester acts as an ESIPT blocking agent. Upon addition of cystein, intermolecular nucleophilic attack of cysteine on acrylic ester releases the fluorescent 3-hydroxyphthalimide derivative, thereby enabling the ESIPT process and leading to enhancement of fluorescence. The probe displays high sensitivity, excellent selectivity and with large Stokes shift toward cysteine. The linear interval range of the fluorescence titration ranged from 0 to 1.0 × 10- 5 M and detection limit is low (6 × 10- 8 M). In addition, the probe could be used for bio-imaging in living cells.

Immunohistochemical analysis of metaplastic non-goblet columnar lined oesophagus shows phenotypic similarities to Barrett's oesophagus: a study in an Asian population.

PubMed

Srivastava, Supriya; Liew, Mei Shan; McKeon, Frank; Xian, Wa; Yeoh, Khay Guan; Ho, Khek Yu; Teh, Ming

2014-02-01

Barrett's oesophagus is a premalignant condition, predisposing to oesophageal adenocarcinoma. However, some adenocarcinoma may arise in columnar lined oesophagus without goblet cells. Our aim was to evaluate the biological properties of non-goblet columnar lined oesophagus only and elucidate its relationship with Barrett's oesophagus and associated neoplasia. Endoscopic biopsies from patients with Barrett's oesophagus (n=30), non-goblet columnar lined oesophagus (n=14), Barrett's oesophagus associated high grade dysplasia (n=6) and adenocarcinoma (n=4) were selected. Immunostaining for villin, claudin 3 and MUC4 was performed. Statistical analysis was performed and a p value <0.05 was considered significant. Villin and MUC4 were positive in 42%, 100% each and 50% in non-goblet columnar lined oesophagus, Barrett's oesophagus, high grade dysplasia and adenocarcinoma respectively, while claudin 3 was 100% positive in all the groups. In non-goblet columnar lined oesophagus, six cases that were villin immunopositive, showed positive expression for claudin 3 and/or MUC4 and there was no difference from the high grade dysplasia or adenocarcinoma (p>0.05). Our results indicate that a subset of non-goblet columnar lined oesophagus shows an intestinal phenotype representing an early stage of Barrett's oesophagus. This subset probably harbours the potential to change into adenocarcinoma in the long term. Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Impact of oral and waterborne administration of rhamnolipids on the susceptibility of channel catfish (Ictalurus punctatus) to Flavobacterium columnare infection

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare is the causative agent of columnaris disease and causes tremendous morbidity and mortality of farmed fish globally. Previously, we identified a potential lectin-mediator (a rhamnose-binding lectin; RBL1a) of F. columnare adhesion and showed higher RBL1a expression in suscept...

Evaluation of the therapeutic effect of potassium permanganate at early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus)

USDA-ARS?s Scientific Manuscript database

The efficacy of potassium permanganate (KMnO4) against early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus) was evaluated. Fish were experimentally challenged, by waterborne exposure for 2 h to F. columnare after cutaneous abrasion, an...

Composition of Extracellular Polymeric Substances (EPS) produced by Flavobacterium columnare isolated from tropical fish in Brazil.

PubMed

de Alexandre Sebastião, Fernanda; Pilarski, Fabiana; Lemos, Manoel Victor Franco

2013-01-01

Thirty nine isolates of Flavobacterium columnare from Brazilian fish farms had their carbohydrate composition of EPS evaluated by high efficiency liquid chromatography, using the phenol-sulfuric acid method of EPS. The occurrence of capsules on F. columnare cells was not directly related to biofilm formation, and the predominant monosaccharide is glucose.

Investigation of the mechanism for phthalate-induced toxicity during male sexual differentiation in the rat

EPA Science Inventory

Male rats exposed to phthalate esters during sexual differentiation (GDI4-GDI8) display various developmental abnormalities of the reproductive tract that are manifested later in adult life. Induction of these malformations is associated with declines in fetal testicular testoste...

Investigation of the mechanism for phthalate-induced toxicity during male sexual differentiation in the rat.

EPA Science Inventory

Male rats exposed to phthalate esters during sexual differentiation (GDI4-GDI8) display various reproductive developmental abnormalities later in adult life which are associated with declines in fetal testicular testosterone (T) production and insulin-like three hormone (lnsl-3...

Strain hardening and fracture behavior during tension of directionally solidified high-nitrogen austenitic steel

NASA Astrophysics Data System (ADS)

Maier, Galina; Astafurova, Elena; Melnikov, Eugene; Moskvina, Valentina; Galchenko, Nina

2017-12-01

The effect of grain orientation relative to tensile load on the strain hardening behavior and fracture mechanism of directionally solidified high-nitrogen steel Fe-20Cr-22Mn-1.5V-0.2C-0.6N (in wt %) was studied. The tensile samples oriented along the longitudinal direction of columnar grains demonstrated the improved mechanical properties compared to specimens with the transversal directions of columnar grains: the values of tensile strength and strain-to-fracture were as high as 1080 MPa and 22%, respectively, for tension along the columnar grains and 870 MPa and 11%, respectively, for the tension transversal to the columnar grains. The change in the grain orientation relative to the tensile load varies a fracture mode of the steel. The fraction of the transgranular fracture was higher in the samples with longitudinal directions of the columnar grains compared to the transversal ones.

Composition of Extracellular Polymeric Substances (EPS) produced by Flavobacterium columnare isolated from tropical fish in Brazil

PubMed Central

de Alexandre Sebastião, Fernanda; Pilarski, Fabiana; Lemos, Manoel Victor Franco

2013-01-01

Thirty nine isolates of Flavobacterium columnare from Brazilian fish farms had their carbohydrate composition of EPS evaluated by high efficiency liquid chromatography, using the phenol-sulfuric acid method of EPS. The occurrence of capsules on F. columnare cells was not directly related to biofilm formation, and the predominant monosaccharide is glucose. PMID:24516426

Mucinous breast carcinoma with tall columnar cells.

PubMed

Tsoukalas, N; Kiakou, M; Tolia, M; Kostakis, I D; Galanopoulos, M; Nakos, G; Tryfonopoulos, D; Kyrgias, G; Koumakis, G

2018-05-01

Mucinous carcinoma of the breast represents 1%-4% of all breast cancers. The World Health Organization classification divides this type of tumour into three different subtypes: mucinous carcinoma, mucinous carcinoma with tall columnar cells (mucinous cystadenocarcinoma and columnar cell mucinous carcinoma) and signet ring cell carcinoma. A 74-year-old woman presented a tumour with inflammatory features in the upper outer quadrant of her left breast, 7 cm in diameter. The core biopsy showed infiltrating ductal carcinoma of no specific type. The tumour-node-metastasis clinical staging was T4cN3M0 (Stage IIIC). She received neoadjuvant chemotherapy, underwent left mastectomy with radical axillary resection and subsequently received radiotherapy and chemotherapy. The histological examination of the surgical specimen revealed two solid tumors in the tail of Spence, which corresponded to adenocarcinoma with high columnar cells. The patient died 16 months after the diagnosis, suffering from pulmonary metastases and anterior chest wall infiltration. A review of the literature revealed only 21 reports of mucinous carcinoma of the breast with tall columnar cells, including our case. This is only the third time that the specific histological type of columnar cell mucinous carcinoma has been reported in the literature.

Radiating columnar joints in Gyeongju, Korea as a educational site

NASA Astrophysics Data System (ADS)

Woo, H.; Kim, J. H.; Jang, Y. D.

2015-12-01

Gyeongju is located in the central eastern part of South Korea. There are various directional columnar joint sets in Tertiary trachytic basalt formation along the shore. In particular, rare radiating columnar joints occur in this area. Columnar joints are parallel, prismatic columns that are formed as a result of contraction during the rapid cooling of lava flow, forming a three dimensional fracture network. In general, the radius and direction of the rock column represent the cooling rate and surface respectively. Radiating direction of columns here indicates that dome- or lobe-shaped lava was cooled from its surface to the core during the viscous lava flow. The fact that the trachytic textures of plagioclase laths are indistinct suggests that the radiating columnar joints are equivalent to the frontal end of the lava lobes. This area is currently has a shore trail course, which is being developed into a picturesque educational park. There are corresponding information boards on the trail near each type of columnar joints to explain not only the forming process and geological mechanisms but the importance of nature conservation to visitors, especially students. A variety of educational materials and educational programs linked to regular school curriculum are also being developed.

Complete genome sequence analysis of the fish pathogen Flavobacterium columnare provides insights into antibiotic resistance and pathogenicity related genes.

PubMed

Zhang, Yulei; Zhao, Lijuan; Chen, Wenjie; Huang, Yunmao; Yang, Ling; Sarathbabu, V; Wu, Zaohe; Li, Jun; Nie, Pin; Lin, Li

2017-10-01

We analyzed here the complete genome sequences of a highly virulent Flavobacterium columnare Pf1 strain isolated in our laboratory. The complete genome consists of a 3,171,081 bp circular DNA with 2784 predicted protein-coding genes. Among these, 286 genes were predicted as antibiotic resistance genes, including 32 RND-type efflux pump related genes which were associated with the export of aminoglycosides, indicating inducible aminoglycosides resistances in F. columnare. On the other hand, 328 genes were predicted as pathogenicity related genes which could be classified as virulence factors, gliding motility proteins, adhesins, and many putative secreted proteases. These genes were probably involved in the colonization, invasion and destruction of fish tissues during the infection of F. columnare. Apparently, our obtained complete genome sequences provide the basis for the explanation of the interactions between the F. columnare and the infected fish. The predicted antibiotic resistance and pathogenicity related genes will shed a new light on the development of more efficient preventional strategies against the infection of F. columnare, which is a major worldwide fish pathogen. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evolution of oesophageal adenocarcinoma from metaplastic columnar epithelium without goblet cells in Barrett's oesophagus.

PubMed

Lavery, Danielle L; Martinez, Pierre; Gay, Laura J; Cereser, Biancastella; Novelli, Marco R; Rodriguez-Justo, Manuel; Meijer, Sybren L; Graham, Trevor A; McDonald, Stuart A C; Wright, Nicholas A; Jansen, Marnix

2016-06-01

Barrett's oesophagus commonly presents as a patchwork of columnar metaplasia with and without goblet cells in the distal oesophagus. The presence of metaplastic columnar epithelium with goblet cells on oesophageal biopsy is a marker of cancer progression risk, but it is unclear whether clonal expansion and progression in Barrett's oesophagus is exclusive to columnar epithelium with goblet cells. We developed a novel method to trace the clonal ancestry of an oesophageal adenocarcinoma across an entire Barrett's segment. Clonal expansions in Barrett's mucosa were identified using cytochrome c oxidase enzyme histochemistry. Somatic mutations were identified through mitochondrial DNA sequencing and single gland whole exome sequencing. By tracing the clonal origin of an oesophageal adenocarcinoma across an entire Barrett's segment through a combination of histopathological spatial mapping and clonal ordering, we find that this cancer developed from a premalignant clonal expansion in non-dysplastic ('cardia-type') columnar metaplasia without goblet cells. Our data demonstrate the premalignant potential of metaplastic columnar epithelium without goblet cells in the context of Barrett's oesophagus. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Sinapic acid or its derivatives interfere with abscisic acid homeostasis during Arabidopsis thaliana seed germination.

PubMed

Bi, Baodi; Tang, Jingliang; Han, Shuang; Guo, Jinggong; Miao, Yuchen

2017-06-06

Sinapic acid and its esters have broad functions in different stages of seed germination and plant development and are thought to play a role in protecting against ultraviolet irradiation. To better understand the interactions between sinapic acid esters and seed germination processes in response to various stresses, we analyzed the role of the plant hormone abscisic acid (ABA) in the regulation of sinapic acid esters involved in seed germination and early seedling growth. We found that exogenous sinapic acid promotes seed germination in a dose-dependent manner in Arabidopsis thaliana. High-performance liquid chromatography mass spectrometry analysis showed that exogenous sinapic acid increased the sinapoylcholine content of imbibed seeds. Furthermore, sinapic acid affected ABA catabolism, resulting in reduced ABA levels and increased levels of the ABA-glucose ester. Using mutants deficient in the synthesis of sinapate esters, we showed that the germination of mutant sinapoylglucose accumulator 2 (sng2) and bright trichomes 1 (brt1) seeds was more sensitive to ABA than the wild-type. Moreover, Arabidopsis mutants deficient in either abscisic acid deficient 2 (ABA2) or abscisic acid insensitive 3 (ABI3) displayed increased expression of the sinapoylglucose:choline sinapoyltransferase (SCT) and sinapoylcholine esterase (SCE) genes with sinapic acid treatment. This treatment also affected the accumulation of sinapoylcholine and free choline during seed germination. We demonstrated that sinapoylcholine, which constitutes the major phenolic component in seeds among various minor sinapate esters, affected ABA homeostasis during seed germination and early seedling growth in Arabidopsis. Our findings provide insights into the role of sinapic acid and its esters in regulating ABA-mediated inhibition of Arabidopsis seed germination in response to drought stress.

Absorption and metabolism of the food contaminant 3-chloro-1,2-propanediol (3-MCPD) and its fatty acid esters by human intestinal Caco-2 cells.

PubMed

Buhrke, Thorsten; Weisshaar, Rüdiger; Lampen, Alfonso

2011-10-01

3-Chloro-1,2-propanediol (3-MCPD) fatty acid esters are formed upon thermal processing of fat-containing foods in the presence of chloride ions. Upon hydrolytic cleavage, these substances could release free 3-MCPD. This compound is toxicologically well characterised and displayed cancerogenic potential in rodent models. Recently, serious contaminations of different food products with 3-MCPD fatty acid esters have been reported. In regard to a risk assessment, the key question is to which degree these 3-MCPD fatty acid esters are hydrolysed in the human gut. Therefore, the aim of the present project was to examine the hydrolysis of 3-MCPD fatty acid esters and the resulting release of free 3-MCPD by using differentiated Caco-2 cells, a cellular in vitro model for the human intestinal barrier. Here, we show that 3-MCPD fatty acid esters at a concentration of 100 μM were neither absorbed by the cells nor the esters were transported via a Caco-2 monolayer. 3-MCPD-1-monoesters were hydrolysed in the presence of Caco-2 cells. In contrast, a 3-MCPD-1,2-diester used in this study was obviously absorbed and metabolised by the cells. Free 3-MCPD was not absorbed by the cells, but the substance migrated through a Caco-2 monolayer by paracellular diffusion. From these in vitro studies, we conclude that 3-MCPD-1-monoesters are likely to be hydrolysed in the human intestine, thereby increasing the burden with free 3-MCPD. In contrast, intestinal cells seem to have the capacity to metabolise 3-MCPD diesters, thereby detoxifying the 3-MCPD moiety.

21 CFR 880.6970 - Liquid crystal vein locator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Liquid crystal vein locator. 880.6970 Section 880.6970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... skin by displaying the color changes of heat sensitive liquid crystals (cholesteric esters). (b...

21 CFR 880.6970 - Liquid crystal vein locator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Liquid crystal vein locator. 880.6970 Section 880.6970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... skin by displaying the color changes of heat sensitive liquid crystals (cholesteric esters). (b...

Research on non-direct reflection columnar microstructure

NASA Astrophysics Data System (ADS)

Wu, B. Q.; Wang, X. Z.; Dong, L. H.

2015-10-01

To minimize the risk of laser accidents, especially those involving eye and skin injuries, it is crucial to pay more attention to laser safety. To control the risk of injury, depending on the laser power and wavelength, a number of required safety measures have been put forward, such as specific protection walls, and wearing safety goggles when operating lasers. The direct reflection columnar microstructure can also be used for laser safety. Based on mathematical foundations , a columnar microstructure is designed by the optical design software LightTools. Simulation showed that there is a tilt angle between the emergent and incident light, the incident light being perpendicular to the microstructure, as well as the phenomenon of no direct reflection happened. A novel testing platform was built for the columnar microstructure after it was machined. The applied testing method can measure the angle between the emergent and incident light. The method lays the condition for the further research. It is shown that the columnar microstructure with no direct reflection can be utilized in laser protection systems.

Direct comparison of Viking 2.3-GHz signal phase fluctuation and columnar electron density between 2 and 160 solar radii

NASA Technical Reports Server (NTRS)

Berman, A. L.; Wackley, J. A.; Hietzke, W. H.

1982-01-01

The relationship between solar wind induced signal phase fluctuation and solar wind columnar electron density has been the subject of intensive analysis during the last two decades. In this article, a sizeable volume of 2.3-GHz signal phase fluctuation and columnar electron density measurements separately and concurrently inferred from Viking spacecraft signals are compared as a function of solar geometry. These data demonstrate that signal phase fluctuation and columnar electron density are proportional over a very wide span of solar elongation angle. A radially dependent electron density model which provides a good fit to the columnar electron density measurements and, when appropriately scaled, to the signal phase fluctuation measurements, is given. This model is also in good agreement with K-coronameter observations at 2 solar radii (2r0), with pulsar time delay measurements at 10r0, and with spacecraft in situ electron density measurements at 1 AU.

Columnar organization of orientation domains in V1

NASA Astrophysics Data System (ADS)

Liedtke, Joscha; Wolf, Fred

In the primary visual cortex (V1) of primates and carnivores, the functional architecture of basic stimulus selectivities appears similar across cortical layers (Hubel & Wiesel, 1962) justifying the use of two-dimensional cortical models and disregarding organization in the third dimension. Here we show theoretically that already small deviations from an exact columnar organization lead to non-trivial three-dimensional functional structures. We extend two-dimensional random field models (Schnabel et al., 2007) to a three-dimensional cortex by keeping a typical scale in each layer and introducing a correlation length in the third, columnar dimension. We examine in detail the three-dimensional functional architecture for different cortical geometries with different columnar correlation lengths. We find that (i) topological defect lines are generally curved and (ii) for large cortical curvatures closed loops and reconnecting topological defect lines appear. This theory extends the class of random field models by introducing a columnar dimension and provides a systematic statistical assessment of the three-dimensional functional architecture of V1 (see also (Tanaka et al., 2011)).

Simulation of the as-cast structure of Al-4.0wt.%Cu ingots with a 5-phase mixed columnar-equiaxed solidification model

NASA Astrophysics Data System (ADS)

Wu, M.; Ahmadein, M.; Kharicha, A.; Ludwig, A.; Li, J. H.; Schumacher, P.

2012-07-01

Empirical knowledge about the formation of the as-cast structure, mostly obtained before 1980s, has revealed two critical issues: one is the origin of the equiaxed crystals; one is the competing growth of the columnar and equiaxed structures, and the columnar-to-equiaxed transition (CET). Unfortunately, the application of empirical knowledge to predict and control the as-cast structure was very limited, as the flow and crystal transport were not considered. Therefore, a 5-phase mixed columnar-equiaxed solidification model was recently proposed by the current authors based on modeling the multiphase transport phenomena. The motivation of the recent work is to determine and evaluate the necessary modeling parameters, and to validate the mixed columnar-equiaxed solidification model by comparison with laboratory castings. In this regard an experimental method was recommended for in-situ determination of the nucleation parameters. Additionally, some classical experiments of the Al-Cu ingots were conducted and the as-cast structural information including distinct columnar and equiaxed zones, macrosegregation, and grain size distribution were analysed. The final simulation results exhibited good agreement with experiments in the case of high pouring temperature, whereas disagreement in the case of low pouring temperature. The reasons for the disagreement are discussed.

Role of microstructure and doping on the mechanical strength and toughness of polysilicon thin films

DOE PAGES

Yagnamurthy, Sivakumar; Boyce, Brad L.; Chasiotis, Ioannis

2015-03-24

We investigated the role of microstructure and doping on the mechanical strength of microscale tension specimens of columnar grain and laminated polysilicon doped with different concentrations of phosphorus. The average tensile strengths of undoped columnar and laminated polysilicon specimens were 1.3 ± 0.1 and 2.45 ± 0.3 GPa, respectively. Heavy doping reduced the strength of columnar polysilicon specimens to 0.9 ± 0.1 GPa. On grounds of Weibull statistics, the experimental results from specimens with gauge sections of 1000 μm × 100 μm × 1 μm predicted quite well the tensile strength of specimens with gauge sections of 150 μm ×more » 3.75 μm × 1 μm, and vice versa. The large difference in the mechanical strength between columnar and laminated polysilicon specimens was due to sidewall flaws in columnar polysilicon, which were introduced during reactive ion etching (RIE) and were further exacerbated by phosphorus doping. Moreover, the removal of the large defect regions at the sidewalls of columnar polysilicon specimens via ion milling increased their tensile strength by 70%-100%, approaching the strength of laminated polysilicon, which implies that the two types of polysilicon films have comparable tensile strength. Measurements of the effective mode I critical stress intensity factor, KIC,eff, also showed that all types of polysilicon films had comparable resistance to fracture. Therefore, additional processing steps to eliminate the edge flaws in RIE patterned devices could result in significantly stronger microelectromechanical system components fabricated by conventional columnar polysilicon films.« less

Tracing a key player in the regulation of plant architecture: the columnar growth habit of apple trees (Malus × domestica).

PubMed

Petersen, Romina; Krost, Clemens

2013-07-01

Plant architecture is regulated by a complex interplay of some key players (often transcription factors), phytohormones and other signaling molecules such as microRNAs. The columnar growth habit of apple trees is a unique form of plant architecture characterized by thick and upright stems showing a compaction of internodes and carrying short fruit spurs instead of lateral branches. The molecular basis for columnar growth is a single dominant allele of the gene Columnar, whose identity, function and gene product are unknown. As a result of marker analyses, this gene has recently been fine-mapped to chromosome 10 at 18.51-19.09 Mb [according to the annotation of the apple genome by Velasco (2010)], a region containing a cluster of quantitative trait loci associated with plant architecture, but no homologs to the well-known key regulators of plant architecture. Columnar apple trees have a higher auxin/cytokinin ratio and lower levels of gibberellins and abscisic acid than normal apple trees. Transcriptome analyses corroborate these results and additionally show differences in cell membrane and cell wall function. It can be expected that within the next year or two, an integration of these different research methodologies will reveal the identity of the Columnar gene. Besides enabling breeders to efficiently create new apple (and maybe related pear, peach, cherry, etc.) cultivars which combine desirable characteristics of commercial cultivars with the advantageous columnar growth habit using gene technology, this will also provide new insights into an elevated level of plant growth regulation.

Columnar cell lesions and pseudoangiomatous hyperplasia like stroma: is there an epithelial-stromal interaction?

PubMed

Recavarren, Rosemary A; Chivukula, Mamatha; Carter, Gloria; Dabbs, David J

2009-10-10

The significance of association between cancer and its microenvironment has been increasingly recognized. It has been shown in animal models that interaction between neoplastic epithelial cells and adjacent stroma can modulate tumor behavior. Carcinoma associated stromal cells can transform normal epithelial cells into neoplastic cells. In breast, columnar cell lesions are non-obligate precursors of low grade ductal carcinoma in situ. Columnar cell lesions can be seen intimately associated with PASH-like-stroma, a lesion we termed as CCPLS. Our aim is to investigate epithelial-stromal interactions in CCPLS and compare them to PASH without columnar cell lesions in breast core needle biopsies. Normal terminal duct lobular unit (TDLU) epithelium was seen in association with columnar cell lesions as well as PASH. Eight (8) cases of each category were examined by a panel of immunostains: CD117 (C-kit), CD34, CD105, bFGF, AR, ER-beta, MIB-1. We observed a markedly decreased expression of c-kit in columnar cell lesions compared to TDLU-epithelium. CD105 showed a quantitative increase in activated vessels in CCPLS compared to PASH. A subset of CCPLS and PASH were androgen receptor positive. A strong nuclear positivity for ER-beta is observed in the epithelium and stroma of all CCPLS cases. We conclude that (1) activated blood vessels predominate in CCPLS; (2) A molecular alteration is signified by c-kit loss in columnar cell lesions; (3) ER-beta and androgen receptor positivity indicate CCPLS are hormonally responsive lesions. Our study suggests an intimate vascular and hormone dependent epithelial-stromal interaction exists in CCPLS lesions.

Genomic biomarkers of phthalate-induced male reproductive developmental toxicity: A targeted rtPCR array approach for defining relative potency

EPA Science Inventory

Male rat fetuses exposed to certain phthalate esters (PEs) during sexual differentiation display reproductive tract malformations due to reductions in testosterone (T) production and the expression of steroidogenesis-and INSL3-related genes. In the current study} we used a 96well...

Creep Deformation and Rupture Behavior of Single- and Dual-Pass 316LN Stainless-Steel-Activated TIG Weld Joints

NASA Astrophysics Data System (ADS)

Vijayanand, V. D.; Vasudevan, M.; Ganesan, V.; Parameswaran, P.; Laha, K.; Bhaduri, A. K.

2016-06-01

Creep deformation and rupture behavior of single-pass and dual-pass 316LN stainless steel (SS) weld joints fabricated by an autogenous activated tungsten inert gas welding process have been assessed by performing metallography, hardness, and conventional and impression creep tests. The fusion zone of the single-pass joint consisted of columnar zones adjacent to base metals with a central equiaxed zone, which have been modified extensively by the thermal cycle of the second pass in the dual-pass joint. The equiaxed zone in the single-pass joint, as well as in the second pass of the dual-pass joint, displayed the lowest hardness in the joints. In the dual-pass joint, the equiaxed zone of the first pass had hardness comparable to the columnar zone. The hardness variations in the joints influenced the creep deformation. The equiaxed and columnar zone in the first pass of the dual-pass joint was more creep resistant than that of the second pass. Both joints possessed lower creep rupture life than the base metal. However, the creep rupture life of the dual-pass joint was about twofolds more than that of the single-pass joint. Creep failure in the single-pass joint occurred in the central equiaxed fusion zone, whereas creep cavitation that originated in the second pass was blocked at the weld pass interface. The additional interface and strength variation between two passes in the dual-pass joint provides more restraint to creep deformation and crack propagation in the fusion zone, resulting in an increase in the creep rupture life of the dual-pass joint over the single-pass joint. Furthermore, the differences in content, morphology, and distribution of delta ferrite in the fusion zone of the joints favors more creep cavitation resistance in the dual-pass joint over the single-pass joint with the enhancement of creep rupture life.

Schistosomicidal Activity of Dihydrobenzofuran Neolignans.

PubMed

Dias, Herbert J; Patrocínio, Andressa B; Pagotti, Mariana C; Fukui, Murilo J; Rodrigues, Vanderlei; Magalhães, Lizandra G; Crotti, Antônio E M

2018-05-13

We have evaluated the antischistosomal activity of synthetic dihydrobenzofuran neolignans (DBNs) derived from (±)-trans-dehydrodicoumarate dimethyl ester (1) and (±)-trans-dehydrodiferulate dimethyl ester (2) against adult Schistosoma mansoni worms in vitro. Compound 4 ((±)-4-O-acetyl-trans-dehydrodiferulate dimethyl ester) displays the most promising activity; at 200 μM, it kills 100±0% of worms after 24 h, which resembles the result achieved with praziquantel (positive control) at 1.56 μM. Hydrogenation of the double bond between C7' and C8', introduction of an additional methyl group at C3', and a double bond between C7 and C8 decreases the schistosomicidal activity of DBNs. On the other hand, the presence of the acetoxy group at C4 plays an interesting role in this activity. These results demonstrate the interesting schistosomicidal potential of DBNs, which could be further exploited. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Liquid crystalline composites toward organic photovoltaic application (Conference Presentation)

NASA Astrophysics Data System (ADS)

Shimizu, Yo; Sosa-Vargas, Lydia; Shin, Woong; Higuchi, Yumi; Itani, Hiromichi; Kawano, Koki; Dao, Quang Duy; Fujii, Akihiko; Ozaki, Masanori

2017-02-01

Liquid crystalline semiconductor is an interesting category of organic electronic materials and also has been extensively studied in terms of "Printed Electronics". For the wider diversity in research toward new applications, one can consider how to use a combination of miscibility and phase separation in liquid crystals. Here we report discotic liquid crystals in making a composite of which structural order is controlled in nano-scale toward photovoltaic applications. Discotic columnar LCs were studied on their resultant molecular order and carrier transport properties. Liquid crystals of phthalocyanine and its analogues which exhibit columnar mesomorphism with high carrier mobility (10-1 cm2/Vs) were examined with making binary phase diagrams and the correlation to carrier transport properties by TOF measurements was discussed. The shape-analogues in chemical structure shows a good miscibility even for the different lattice-type of columnar arrangement and the carrier mobility is mostly decrease except for a case of combination with a metal-free and the metal complex. For the mixtures with non-mesogenic C60 derivatives, one sees a phase-separated structure due to its immiscibility, though the columnar order is remained in a range of component ratio.Especially, in a range of the ratio, it was observed the phase separated C60 derivatives are fused into the matrix of columnar bundles, indicating C60 derivatives could be diffused in columnar arrays in molecular level.

Retaining {1 0 0} texture from initial columnar grains in 6.5 wt% Si electrical steels

NASA Astrophysics Data System (ADS)

Liang, Ruiyang; Yang, Ping; Mao, Weimin

2017-11-01

6.5 wt% Si electrical steel is a superior soft magnetic material with excellent magnetic properties which highly depends on texture. In this study, based on the heredity of 〈0 0 1〉 orientation in columnar grains, columnar grains are used as the initial material to prepare non-oriented 6.5 wt% Si electrical steel with excellent magnetic properties. EBSD and XRD techniques are adopted to explore the structure and texture evolution during hot rolling, warm rolling, cold rolling and annealing. The results show that, due to the heredity of "structure and texture" from the initial strong {1 0 0} columnar grains, annealed sheet with {1 0 0}〈0 0 1〉 texture had better magnetic properties, which can be used as non-oriented high-silicon electrical steel. Both preferred cube grain nucleation in deformed {1 1 3}〈3 6 1〉 grains in subsurface and coarse {1 0 0}〈0 0 1〉 deformed grains in center layer show the effect of initial columnar grains with {1 0 0} texture.

Modulating laser intensity profile ellipticity for microstructural control during metal additive manufacturing

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

Roehling, Tien T.; Wu, Sheldon S. Q.; Khairallah, Saad A.

Additively manufactured (AM) metals are often highly textured, containing large columnar grains that initiate epitaxially under steep temperature gradients and rapid solidification conditions. These unique microstructures partially account for the massive property disparity existing between AM and conventionally processed alloys. Although equiaxed grains are desirable for isotropic mechanical behavior, the columnar-to-equiaxed transition remains difficult to predict for conventional solidification processes, and much more so for AM. In this study, the effects of laser intensity profile ellipticity on melt track macrostructures and microstructures were studied in 316L stainless steel. Experimental results were supported by temperature gradients and melt velocities simulated usingmore » the ALE3D multi-physics code. As a general trend, columnar grains preferentially formed with increasing laser power and scan speed for all beam profiles. However, when conduction mode laser heating occurs, scan parameters that result in coarse columnar microstructures using Gaussian profiles produce equiaxed or mixed equiaxed-columnar microstructures using elliptical profiles. Furthermore, by modulating spatial laser intensity profiles on the fly, site-specific microstructures and properties can be directly engineered into additively manufactured parts.« less

Modulating laser intensity profile ellipticity for microstructural control during metal additive manufacturing

DOE PAGES

Roehling, Tien T.; Wu, Sheldon S. Q.; Khairallah, Saad A.; ...

2017-02-12

Additively manufactured (AM) metals are often highly textured, containing large columnar grains that initiate epitaxially under steep temperature gradients and rapid solidification conditions. These unique microstructures partially account for the massive property disparity existing between AM and conventionally processed alloys. Although equiaxed grains are desirable for isotropic mechanical behavior, the columnar-to-equiaxed transition remains difficult to predict for conventional solidification processes, and much more so for AM. In this study, the effects of laser intensity profile ellipticity on melt track macrostructures and microstructures were studied in 316L stainless steel. Experimental results were supported by temperature gradients and melt velocities simulated usingmore » the ALE3D multi-physics code. As a general trend, columnar grains preferentially formed with increasing laser power and scan speed for all beam profiles. However, when conduction mode laser heating occurs, scan parameters that result in coarse columnar microstructures using Gaussian profiles produce equiaxed or mixed equiaxed-columnar microstructures using elliptical profiles. Furthermore, by modulating spatial laser intensity profiles on the fly, site-specific microstructures and properties can be directly engineered into additively manufactured parts.« less

Molecular Basis of Prodrug Activation by Human Valacyclovirase, an [alpha]-Amino Acid Ester Hydrolase

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

Lai, Longsheng; Xu, Zhaohui; Zhou, Jiahai

2008-07-08

Chemical modification to improve biopharmaceutical properties, especially oral absorption and bioavailability, is a common strategy employed by pharmaceutical chemists. The approach often employs a simple structural modification and utilizes ubiquitous endogenous esterases as activation enzymes, although such enzymes are often unidentified. This report describes the crystal structure and specificity of a novel activating enzyme for valacyclovir and valganciclovir. Our structural insights show that human valacyclovirase has a unique binding mode and specificity for amino acid esters. Biochemical data demonstrate that the enzyme hydrolyzes esters of {alpha}-amino acids exclusively and displays a broad specificity spectrum for the aminoacyl moiety similar tomore » tricorn-interacting aminopeptidase F1. Crystal structures of the enzyme, two mechanistic mutants, and a complex with a product analogue, when combined with biochemical analysis, reveal the key determinants for substrate recognition; that is, a flexible and mostly hydrophobic acyl pocket, a localized negative electrostatic potential, a large open leaving group-accommodating groove, and a pivotal acidic residue, Asp-123, after the nucleophile Ser-122. This is the first time that a residue immediately after the nucleophile has been found to have its side chain directed into the substrate binding pocket and play an essential role in substrate discrimination in serine hydrolases. These results as well as a phylogenetic analysis establish that the enzyme functions as a specific {alpha}-amino acid ester hydrolase. Valacyclovirase is a valuable target for amino acid ester prodrug-based oral drug delivery enhancement strategies.« less

The hydrolysis kinetics of monobasic and dibasic aminoalkyl esters of ketorolac.

PubMed

Qandil, Amjad M; Jamhawi, Noor M; Tashtoush, Bassam M; Al-Ajlouni, Ahmad M; Idkaidek, Nasir M; Obaidat, Aiman A

2013-09-01

Six aminoethyl and aminobutyl esters of ketorolac containing 1-methylpiperazine (MPE and MPB), N-acetylpiperazine (APE and APB) or morpholine (ME and MB), were synthesized and their hydrolysis kinetics were studied. The hydrolysis was studied at pH 1 to 9 (for MPE, APE and ME) and pH 1 to 8 (for MPB, APB and MB) in aqueous phosphate buffer (0.16 M) with ionic strength (0.5 M) at 37°C. Calculation of k(obs), construction of the pH-rate profiles and determination of the rate equations were performed using KaleidaGraph® 4.1. The hydrolysis displays pseudo-first order kinetics and the pH-rate profiles shows that the aminobutyl esters, MPE, APB and MB, are the most stable. The hydrolysis of the ethyl esters MPE, APE and ME, depending on the pH, is either fast and catalyzed by the hydroxide anion or slow and uncatalyzed for the diprotonated, monoprotonated and nonprotonated forms. The hydrolysis of the butyl esters showed a similar profile, albeit it was also catalyzed by hydronium cation. In addition, the hydroxide anion is 105 more effective in catalyzing the hydrolysis than the hydronium cation. The hydrolysis pattern of the aminoethyl esters is affected by the number and pKa of its basic nitrogen atoms. The monobasic APE and ME, show a similar hydrolysis pattern that is different than the dibasic MPE. The length of the side chain and the pKa of the basic nitrogen atoms in the aminoethyl moiety affect the mechanism of hydrolysis as the extent of protonation at a given pH is directly related to the pKa.

CHANGES IN FETAL TESTIS GENE EXPRESSION AND STEROID HORMONE SYNTHESIS INDUCED IN MALE OFFSPRING AFTER MATERNAL TREATMENT WITH PHTHALATE ESTERS

EPA Science Inventory

Targeted inactivation of the insulin-like hormone 3 (insl3) gene in male mice results in altered gubernacular development, disrupted testis decent, and cryptorchidism. Cryptorchidism is a fairly common human malformation, being displayed in 1-3% of males at birth. Since only a s...

Simvastatin and Dipentyl Phthalate Display Different Mechanisms of Action but Exhibit Dose Additive Effects on Fetal Testicular Testosterone Production in Sprague Dawley Rats

EPA Science Inventory

Sex differentiation of the male reproductive tract in mammals is driven, in part, by fetal androgen production. In utero exposure to some phthalate esters (PEs) alters fetal Leydig cell differentiation, reducing the expression of several genes associated with steroid synthesis/tr...

Combining multiple regression and principal component analysis for accurate predictions for column ozone in Peninsular Malaysia

NASA Astrophysics Data System (ADS)

Rajab, Jasim M.; MatJafri, M. Z.; Lim, H. S.

2013-06-01

This study encompasses columnar ozone modelling in the peninsular Malaysia. Data of eight atmospheric parameters [air surface temperature (AST), carbon monoxide (CO), methane (CH4), water vapour (H2Ovapour), skin surface temperature (SSKT), atmosphere temperature (AT), relative humidity (RH), and mean surface pressure (MSP)] data set, retrieved from NASA's Atmospheric Infrared Sounder (AIRS), for the entire period (2003-2008) was employed to develop models to predict the value of columnar ozone (O3) in study area. The combined method, which is based on using both multiple regressions combined with principal component analysis (PCA) modelling, was used to predict columnar ozone. This combined approach was utilized to improve the prediction accuracy of columnar ozone. Separate analysis was carried out for north east monsoon (NEM) and south west monsoon (SWM) seasons. The O3 was negatively correlated with CH4, H2Ovapour, RH, and MSP, whereas it was positively correlated with CO, AST, SSKT, and AT during both the NEM and SWM season periods. Multiple regression analysis was used to fit the columnar ozone data using the atmospheric parameter's variables as predictors. A variable selection method based on high loading of varimax rotated principal components was used to acquire subsets of the predictor variables to be comprised in the linear regression model of the atmospheric parameter's variables. It was found that the increase in columnar O3 value is associated with an increase in the values of AST, SSKT, AT, and CO and with a drop in the levels of CH4, H2Ovapour, RH, and MSP. The result of fitting the best models for the columnar O3 value using eight of the independent variables gave about the same values of the R (≈0.93) and R2 (≈0.86) for both the NEM and SWM seasons. The common variables that appeared in both regression equations were SSKT, CH4 and RH, and the principal precursor of the columnar O3 value in both the NEM and SWM seasons was SSKT.

Functional trade-offs in succulent stems predict responses to climate change in columnar cacti.

PubMed

Williams, David G; Hultine, Kevin R; Dettman, David L

2014-07-01

Columnar cacti occur naturally in many habitats and environments in the Americas but are conspicuously dominant in very dry desert regions. These majestic plants are widely regarded for their cultural, economic, and ecological value and, in many ecosystems, support highly diverse communities of pollinators, seed dispersers, and frugivores. Massive amounts of water and other resources stored in the succulent photosynthetic stems of these species confer a remarkable ability to grow and reproduce during intensely hot and dry periods. Yet many columnar cacti are potentially under severe threat from environmental global changes, including climate change and loss of habitat. Stems in columnar cacti and other cylindrical-stemmed cacti are morphologically diverse; stem volume-to-surface area ratio (V:S) across these taxa varies by almost two orders of magnitude. Intrinsic functional trade-offs are examined here across a broad range of V:S in species of columnar cacti. It is proposed that variation in photosynthetic gas exchange, growth, and response to stress is highly constrained by stem V:S, establishing a mechanistic framework for understanding the sensitivity of columnar cacti to climate change and drought. Specifically, species that develop stems with low V:S, and thus have little storage capacity, are expected to express high mass specific photosynthesis and growth rates under favourable conditions compared with species with high V:S. But the trade-off of having little storage capacity is that low V:S species are likely to be less tolerant of intense or long-duration drought compared with high V:S species. The application of stable isotope measurements of cactus spines as recorders of growth, water relations, and metabolic responses to the environment across species of columnar cacti that vary in V:S is also reviewed. Taken together, our approach provides a coherent theory and required set of observations needed for predicting the responses of columnar cacti to climate change. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Occurrence of thyroid hormone activities in drinking water from eastern China: contributions of phthalate esters.

PubMed

Shi, Wei; Hu, Xinxin; Zhang, Fengxian; Hu, Guanjiu; Hao, Yingqun; Zhang, Xiaowei; Liu, Hongling; Wei, Si; Wang, Xinru; Giesy, John P; Yu, Hongxia

2012-02-07

Thyroid hormone is essential for the development of humans. However, some synthetic chemicals with thyroid disrupting potentials are detectable in drinking water. This study investigated the presence of thyroid active chemicals and their toxicity potential in drinking water from five cities in eastern China by use of an in vitro CV-1 cell-based reporter gene assay. Waters were examined from several phases of drinking water processing, including source water, finished water from waterworks, tap water, and boiled tap water. To identify the responsible compounds, concentrations and toxic equivalents of a list of phthalate esters were quantitatively determined. None of the extracts exhibited thyroid receptor (TR) agonist activity. Most of the water samples exhibited TR antagonistic activities. None of the boiled water displayed the TR antagonistic activity. Dibutyl phthalate accounted for 84.0-98.1% of the antagonist equivalents in water sources, while diisobutyl phthalate, di-n-octyl phthalate and di-2-ethylhexyl phthalate also contributed. Approximately 90% of phthalate esters and TR antagonistic activities were removable by waterworks treatment processes, including filtration, coagulation, aerobic biodegradation, chlorination, and ozonation. Boiling water effectively removed phthalate esters from tap water. Thus, this process was recommended to local residents to reduce certain potential thyroid related risks through drinking water.

Controlled release from aspirin based linear biodegradable poly(anhydride esters) for anti-inflammatory activity.

PubMed

Dasgupta, Queeny; Movva, Sahitya; Chatterjee, Kaushik; Madras, Giridhar

2017-08-07

This work reports the synthesis of a novel, aspirin-loaded, linear poly (anhydride ester) and provides mechanistic insights into the release of aspirin from this polymer for anti-inflammatory activity. As compared to conventional drug delivery systems that rely on diffusion based release, incorporation of bioactives in the polymer backbone is challenging and high loading is difficult to achieve. In the present study, we exploit the pentafunctional sugar alcohol (xylitol) to provide sites for drug (aspirin) attachment at its non-terminal OH groups. The terminal OH groups are polymerized with a diacid anhydride. The hydrolysis of the anhydride and ester bonds under physiological conditions release aspirin from the matrix. The resulting poly(anhydride ester) has high drug loading (53%) and displays controlled release kinetics of aspirin. The polymer releases 8.5 % and 20%, of the loaded drug in one and four weeks, respectively and has a release rate constant of 0.0035h -0.61 . The release rate is suitable for its use as an anti-inflammatory agent without being cytotoxic. The polymer exhibits good cytocompatibility and anti-inflammatory properties and may find applications as injectable or as an implantable bioactive material. The physical insights into the release mechanism can provide development of other drug loaded polymers. Copyright © 2017 Elsevier B.V. All rights reserved.

A High T(sub g) PMR Polyimide Composites (DMBZ-15)

NASA Technical Reports Server (NTRS)

Chuang, Kathy C.; Bowles, Kenneth J.; Papadopoulos, Demitrios S.; Hardy-Green, DeNise; Mccorkle, Linda

2000-01-01

A high T(sub g) thermosetting PMR-type polyimide, designated as DMBZ-15, was developed by replacing methylene dianline (MDA) in PMR-15 with 2,2'-dimethylbenzidine. Polyimide/carbon fiber (T650-35) composites were fabricated from a formulation of 3,3', 4,4'-benzophenonetetracarboxylic acid dimethyl ester (BTDE) and 2,2'-dimethylbenzidine (DMBZ), along with nadic ester (NE) as the endcap. DMBZ-15 displays a higher glass transition temperature (T(sub g) = 414 C) than PMR-15 (T(sub g) = 345 C), and thus retains better mechanical properties for brief exposure above 400 C. The physical properties and longterm thermo-oxidative stability of the DMBZ-15 polyimide/carbon fiber composites are also compared to that of PMR-15.

Synthesis of heteroaromatic tropeines and heterogeneous binding to glycine receptors.

PubMed

Maksay, Gábor; Vincze, Zoltán; Nemes, Péter

2009-10-01

Heteroaromatic carboxylic esters of (nor)tropine were synthesized. Tropine esters displaced [(3)H]strychnine binding to glycine receptors of rat spinal cord with low Hill slopes. Two-site displacement resulted in nanomolar IC(50,1) and micromolar IC(50,2) values, and IC(50,2)/IC(50,1) ratios up to 615 depending on the heteroaromatic rings and N-methyl substitution. Nortropeines displayed high affinity and low heterogeneity. IC(50,1) and IC(50,2) values of tropeines did not correlate suggesting different binding modes/sites. Glycine potentiated only the nanomolar displacement reflecting positive allosteric interactions and potentiation of ionophore function. Affinities of three (nor)tropeines were different for glycine receptors but identical for 5-HT(3) receptors.

Enantiomerically Enriched α-Methyl Amino Acids. Use of an Acyclic, Chiral Alanine-Derived Dianion with a High Diastereofacial Bias.†

PubMed Central

Berkowitz, David B.; Smith, Marianne K.

2018-01-01

Hindered esters derived from N-benzoylalanine and the following chiral alcohols have been synthesized: (1) (−)-isopinocampheol; (2) (−)-trans-2-phenylcyclohexanol and (3) (−)-8-phenylmenthol. Sequential treatment of these esters with LDA (1.2 equiv.) and n-butyllithium (2.4 equiv.) at −78°C in THF generates the corresponding chiral dianions. Alkylation of each of these with benzyl bromide reveals that only the (−)-8-phenylmenthyl auxiliary confers a high diastereofacial bias upon its derivative dianion. In fact, that dianion (6) consistently displays diastereomeric ratios in the range of 89:11 to 94:6 for alkylations with a spectrum of nine alkyl halides. If one recrystallization step is included, a single diastereomeric product may be obtained, as is demonstrated for the benzylation of 6. Of particular note, the alkylation with 3,4-bis(tert-butyldimethylsilyloxy)benzyl bromide (18) (94:6 diast. ratio, 72% yield) constitutes a formal synthesis of the clinically important antihypertensive (S)-α-methyl-DOPA (Aldomet), in enantiomerically enriched from. In all cases studied, yields are markedly improved, yet diastereoselectivities unchanged, by the addition of 10% HMPA to the reaction milieu. The (−)-8-phenylmenthol chiral auxiliary is conveniently recovered via ester cleavage with KO2/18-crown-6, following alkylation. Complete deprotection affords enantiomerically enriched (S)-α-methyl amino acids, in all cases examined, indicating that dianion 6 displays a substantial bias in favor of si face alkylation. This sense of diastereoselection is consistent with a chain-extended, internal chelate model for the reactive conformation of the dianion.

Effect of boundary heat flux on columnar formation in binary alloys: A phase-field study

NASA Astrophysics Data System (ADS)

Du, Lifei; Zhang, Peng; Yang, Shaomei; Chen, Jie; Du, Huiling

2018-02-01

A non-isothermal phase-field model was employed to simulate the columnar formation during rapid solidification in binary Ni-Cu alloy. Heat flux at different boundaries was applied to investigate the temperature gradient effect on the morphology, concentration and temperature distributions during directional solidifications. With the heat flux input/extraction from boundaries, coupling with latent heat release and initial temperature gradient, temperature distributions are significantly changed, leading to solute diffusion changes during the phase-transition. Thus, irregular columnar structures are formed during the directional solidification, and the concentration distribution in solid columnar arms could also be changed due to the different growing speeds and temperature distributions at the solid-liquid interfaces. Therefore, applying specific heat conditions at the solidifying boundaries could be an efficient way to control the microstructure during solidifications.

Role of intragastric and intraoesophageal alkalinisation in the genesis of complications in Barrett's columnar lined lower oesophagus.

PubMed Central

Attwood, S E; Ball, C S; Barlow, A P; Jenkinson, L; Norris, T L; Watson, A

1993-01-01

Patients with Barrett's columnar lined lower oesophagus have severe acid gastrooesophageal reflux and may develop complications, including ulceration, stricture, and carcinoma. The aim of this study was to establish if a relationship exists between the pH profile in the oesophagus and stomach and the development of complications in patients with Barrett's columnar lined lower oesophagus. Twenty four hour ambulatory oesophageal pH monitoring was performed in 26 patients with Barrett's columnar lined lower oesophagus and combined with 24 hour ambulatory gastric pH monitoring in 16. Ten of the 26 with Barrett's columnar lined lower oesophagus had complications including stricture (eight), deep ulceration (one), and carcinoma (one). Oesophageal acid exposure (% time < pH 4) was similar in patients with or without complications (19.2% v 19.3% p > 0.05). Oesophageal alkaline exposure (% time > pH 7) was greater in patients with complications (24.2% v 8.4% p > 0.05). Of the 16 patients who underwent gastric pH monitoring there was a clear relationship between gastric and oesophageal alkalinisation in 13. These results support the hypothesis that complications in Barrett's columnar lined lower oesophagus develop in association with increased exposure of the oesophagus to an alkaline environment which appears to be secondary to duodenogastric reflux. The routine use of 24 hour ambulatory gastric pH monitoring in conjunction with oesophageal pH monitoring can help identify those patients at risk. PMID:8432439

Columnar Self-Assembly of Electron-Deficient Dendronized Bay-Annulated Perylene Bisimides.

PubMed

Gupta, Ravindra Kumar; Shankar Rao, Doddamane S; Prasad, S Krishna; Achalkumar, Ammathnadu S

2018-03-07

Three new heteroatom bay-annulated perylene bisimides (PBIs) have been synthesized by microwave-assisted synthesis in excellent yield. N-annulated and S-annulated perylene bisimides exhibited columnar hexagonal phase, whereas Se-annulated perylene bisimide exhibited low temperature columnar oblique phase in addition to the high temperature columnar hexagonal phase. The cup shaped bay-annulated PBIs pack into columns with enhanced intermolecular interactions. In comparison to PBI, these molecules exhibited lower melting and clearing temperature, with good solubility. A small red shift in the absorption was seen in the case of N-annulated PBI, whereas S- and Se-annulated PBIs exhibited blue-shifted absorption spectra. Bay-annulation increased the HOMO and LUMO levels of the N-annulated perylene bisimide, whereas a slight increase in the LUMO level and a decrease in the HOMO levels were observed in the case of S- and Se-annulated perylene bisimides, in comparison to the simple perylene bisimide. The band gaps of PBI and PBI-N were almost same, whereas an increase in the band gaps were observed in the case of S- and Se-annulated PBIs. The tendency to freeze in the ordered glassy columnar phase for PBI-N and PBI-S will help to overcome the charge traps due to crystallization, which are detrimental to one-dimensional charge carrier mobility. These solution processable electron deficient columnar semiconductors possessing good thermal stability may form an easily accessible promising class of n-type materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mucosal polyamine metabolism in the columnar lined oesophagus.

PubMed Central

Gray, M R; Wallace, H M; Goulding, H; Hoffman, J; Kenyon, W E; Kingsnorth, A N

1993-01-01

Mucosal ornithine decarboxylase activity and polyamine content has been proposed as a possible marker for malignant potential in gastrointestinal mucosa. Polyamine content and histological findings were examined in 107 pairs of endoscopic biopsy specimens taken from gastric fundus, fundic and specialised Barrett's oesophagus and Barrett's adenocarcinoma. The content of putrescine (median nmol/mg protein, range) the primary product of ornithine decarboxylase showed a progressive increase from gastric fundus (0.41, 0.15-1.5); fundic (0.45, 0.01-4.08); specialised Barrett's oesophagus (0.54, 0.01-2.0); dysplastic columnar lined oesophagus (0.56, 0.31-3.1) to adenocarcinoma (1.23, 0.29-8.98). Adenocarcinoma putrescine content was significantly greater than gastric fundus (p < 0.018) and fundic (p < 0.03). Mucosal spermine, spermidine, and total polyamine values were greater in gastric fundus than fundic, specialised Barrett's oesophagus, and dysplastic columnar lined oesophagus (all p < 0.001) suggesting failure to further metabolise putrescine to its higher polyamines in the metaplastic epithelium. Although metaplastic columnar lined oesophagus shows significant differences in polyamine metabolic activity from the stomach the important distinction between specialised and dysplastic columnar lined oesophagus cannot be made by measuring the polyamine content. PMID:8504955

Columnar to Nematic Mesophase Transition: Binary Mixtures of Unlike Copper Soaps

NASA Astrophysics Data System (ADS)

Seghrouchni, R.; Skoulios, A.

1995-10-01

Copper (II) soaps are known to produce columnar mesophases at high temperature. The polar groups of the soap molecules are stacked over one another within columns surrounded by the alkyl chains in a disordered conformation and laterally arranged according to a two-dimensional hexagonal lattice. The present work studies the mesomorphic behaviour of binary mixtures of copper soaps using differential scanning calorimetry, polarizing microscopy, and X-ray diffraction. When the soaps are of comparable molecular sizes the mixtures are homogeneous and columnar at all compositions. The columns of the two soaps, remaining intact in the mixture, are distributed randomly on the nodes of a hexagonal Bravais lattice. Crystallographic homogeneity is obtained by transfer of methylene groups from cell to cell. When, on the other hand, the soaps are different enough in molecular sizes, the columnar structure of the mixtures is interrupted in the middle range of compositions for the benefit of a nematic one. The transfer of methylene groups gets indeed harder to achieve and the distortion of the hexagonal units cells becomes important. The columnar to nematic phase transition is discussed on a molecular and a topological level.

The immunophenotypic relationship between the submucosal gland unit, columnar metaplasia and squamous islands in the columnar-lined oesophagus.

PubMed

Lörinc, Ester; Mellblom, Lennart; Öberg, Stefan

2015-12-01

To characterize the immunophenotypic relationship between the squamous and the glandular compartments in the oesophagus of patients with columnar-lined oesophagus (CLO). Eight tissue blocks from three oesophageal resection specimens from patients who underwent oesophagectomy for adenocarcinoma of the oesophagus were selected for immunohistochemical analysis. The markers of intestinal differentiation [CK20, CDX2 and MUC2] were all expressed in the expected pattern, solely in the glandular compartment of the resection specimens. CK4, CK17 and lysozyme were expressed in both the glandular and the squamous compartments. In addition, CK17 expression was found on both the squamous and glandular margins of the squamocolumnar transformation zones and in the submucosal gland (SMG) intraglandular and excretory ducts. There is an immunophenotypic relationship between the squamous and the glandular compartments of the CLO, with expression of lysozyme, CK4 and CK17 in both squamous and columnar cells. These overlapping immunophenotypes indicate similar differentiation paths, and link the SMG unit with the columnar metaplasia and the neosquamous islands in CLO. Our findings support the theory of a cellular origin of CLO and neosquamous islands from the SMG unit. © 2015 John Wiley & Sons Ltd.

Multifunctional Parylene-C Microfibrous Thin Films

NASA Astrophysics Data System (ADS)

Chindam, Chandraprakash

Towards sustainable development, multifunctional products have many advantageous over single-function products: reduction in number of parts, raw material, assembly time, and cost involved in a product's life cycle. My goal for this thesis was to demonstrate the multifunctionalities of Parylene-C microfibrous thin films. To achieve this goal, I chose Parylene C, a polymer, because the fabrication of periodic mediums of Parylene C in the form of microfibrous thin films (muFTFs) was already established. A muFTFs is a parallel arrangement of identical micrometer-sized fibers of shapes cylindrical, chevronic, or helical. Furthermore, Parylene C had three existing functions: in medical-device industries as corrosion-resistive coatings, in electronic industries as electrically insulating coatings, and in biomedical research for tissue-culture substrates. As the functionalities of a material are dependent on the microstructure and physical properties, the investigation made for this thesis was two-fold: (1) Experimentally, I determined the wetting, mechanical, and dielectric properties of columnar muFTFs and examined the microstructural and molecular differences between bulk films and muFTFs. (2) Using physical properties of bulk film, I computationally determined the elastodynamic and determined the electromagnetic filtering capabilities of Parylene-C muFTFs. Several columnar muFTFs of Parylene C were fabricated by varying the monomer deposition angle. Following are the significant experimental findings: 1. Molecular and microstructural characteristics: The dependence of the microfiber inclination angle on the monomer deposition angle was classified into four regimes of two different types. X-ray diffraction experiments indicated that the columnar muFTFs contain three crystal planes not evident in bulk Parylene-C films and that the columnar muFTFs are less crystalline than bulk films. Infrared absorbance spectra revealed that the atomic bonding is the same in all columnar muFTFs and bulk films. The static hydrophobicity of columnar muFTFs was found to be anisotropic and can be maximized by a proper choice of monomer deposition angle. In contrast, the hydrophobicity of bulk film is isotropic. 2. Mechanical properties: Dynamic storage and loss moduli of columnar muFTFs were determined in the 1 to 80 Hz frequency range for temperatures between -40 °C and 125 °C in one of two orthogonal directions lying wholly in the substrate plane: either (i) normal or (ii) parallel to the morphologically significant plane of the muFTF. The storage and loss moduli for normal loading did not exceed their counterparts for parallel loading. All columnar muFTFs were found to be softer than a bulk film. In both bulk and columnar forms, Parylene C was found to be rheologically not simple. 3. Relative permittivity: The charge-storage and absorption properties measured for the columnar muFTFs in the 100 Hz-1 MHz frequency range over temperatures between -40 °C and 125 °C were lower than the bulk film. Internal surfaces of the columnar muFTFs were found to increase the charge-storage capacity. The lower charge-storage capability of columnar muFTFs suggests their possible applications as interlayer dielectrics. The frequency dependence of the relative permittivity of the columnar muFTFs was identified in terms of the Hashin-Shrtikmann model. The elastodynamic bandgaps of Parylene-C muFTFs as phononic crystals were computationally determined for the columnar, chevronic, and chiral muFTFs. Microfibers were arranged either on a square or a hexagonal lattice with the host medium as either water or air. Following are the significant findings: 1. All bandgaps were observed to lie in the 0.01-162.9-MHz regime. The upper limit of the frequency of bandgaps was the highest for the columnar muFTFs and the lowest for the chiral muFTFs. More bandgaps were found to exist when the host medium is water than air. The presence of complete bandgaps suggests their use as bulk-acoustic-wave and surface-acoustic-wave filters. The softness of the Parylene-C muFTFs makes them mechanically tunable, and their bandgaps can be exploited in multiband ultrasonic filters. An investigation was made to demonstrate Parylene-C muFTFs as circular-polarization filters. 1. The relative permittivity of bulk Parylene C was determined as a function of frequency between 15 THz and 149 THz. Potential application of chiral muFTFs as reflectors of thermal energy was identified. The circular Bragg regime for chiral muFTFs of Parylene C was identified as 31.8-35.2 THz, making them useful as circular-polarization band-rejection filters.

Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

PubMed

Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

2013-01-01

A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage.

Shape-Persistent, Sterically Crowded Star Mesogens: From Exceptional Columnar Dimer Stacks to Supermesogens.

PubMed

Lehmann, Matthias; Maier, Philipp

2015-08-10

Hexasubstituted C3 -symmetric benzenes with three oligophenylenevinylene (OPV) arms and three pyridyl or phenyl substituents are shape-persistent star mesogens that are sterically crowded in the center. Such molecular structures possess large void spaces between their arms, which have to be filled in condensed phases. For the neat materials, this is accomplished by an exceptional formation of dimers and short-range helical packing in columnar mesophases. The mesophase is thermodynamically stable for the pyridyl compound. Only this derivative forms filled star-shaped supermesogens in the presence of various carboxylic acids. The latter do not arrange as dimers, but as monomers along the columnar stacks. In this liquid crystal (LC) phase, the guests are completely enclosed by the hosts. Therefore, the host can be regarded as a new LC endoreceptor, which allows the design of columnar functional structures in the future. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ISS-Experiments of Columnar-to-Equiaxed Transition in Solidification Processing

NASA Technical Reports Server (NTRS)

Sturz, Laszlo; Zimmermann, Gerhard; Gandin, Charles, Andre; Billia, Bernard; Magelinck, Nathalie; Nguyen-Thi, Henry; Browne, David John; Mirihanage, Wajira U.; Voss, Daniela; Beckermann, Christoph;

Frequency preference and attention effects across cortical depths in the human primary auditory cortex.

PubMed

De Martino, Federico; Moerel, Michelle; Ugurbil, Kamil; Goebel, Rainer; Yacoub, Essa; Formisano, Elia

2015-12-29

Columnar arrangements of neurons with similar preference have been suggested as the fundamental processing units of the cerebral cortex. Within these columnar arrangements, feed-forward information enters at middle cortical layers whereas feedback information arrives at superficial and deep layers. This interplay of feed-forward and feedback processing is at the core of perception and behavior. Here we provide in vivo evidence consistent with a columnar organization of the processing of sound frequency in the human auditory cortex. We measure submillimeter functional responses to sound frequency sweeps at high magnetic fields (7 tesla) and show that frequency preference is stable through cortical depth in primary auditory cortex. Furthermore, we demonstrate that-in this highly columnar cortex-task demands sharpen the frequency tuning in superficial cortical layers more than in middle or deep layers. These findings are pivotal to understanding mechanisms of neural information processing and flow during the active perception of sounds.

Diatomite-supported Pd-M (M=Cu, Co, Ni) bimetal nanocatalysts for selective hydrogenation of long-chain aliphatic esters.

PubMed

Huang, Changliang; Zhang, Hongye; Zhao, Yanfei; Chen, Sha; Liu, Zhimin

2012-11-15

Diatomite supported Pd-M (M=Cu, Co, Ni) bimetal nanocatalysts with various metal compositions were prepared and characterized by means of X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. It was demonstrated that the metal nanoparticles were uniformly distributed on the support, and their size was centered around 8 nm with a relatively narrow size distribution. The catalysts were used to catalyze hydrogenation of long-chain aliphatic esters, including methyl palmitate, methyl stearate, and methyl laurate. It was indicated that the all diatomite-supported Pd-based bimetal catalysts were active to the selective hydrogenation of long-chain esters to corresponding alcohols at 270°C, originated from the synergistic effect between the metal particles and the diatomite support. For the selective hydrogenation of methyl palmitate, Pd-Cu/diatomite with metal loading of 1% and Pd/Cu=3 displayed the highest performance, giving a 1-hexadecanol yield of 82.9% at the substrate conversion of 98.8%. Copyright © 2012 Elsevier Inc. All rights reserved.

Injectable hyperbranched poly(β-amino ester) hydrogels with on-demand degradation profiles to match wound healing processes.

PubMed

Xu, Qian; Guo, Linru; A, Sigen; Gao, Yongsheng; Zhou, Dezhong; Greiser, Udo; Creagh-Flynn, Jack; Zhang, Hong; Dong, Yixiao; Cutlar, Lara; Wang, Fagang; Liu, Wenguang; Wang, Wei; Wang, Wenxin

2018-02-28

Adjusting biomaterial degradation profiles to match tissue regeneration is a challenging issue. Herein, biodegradable hyperbranched poly(β-amino ester)s (HP-PBAEs) were designed and synthesized via "A2 + B4" Michael addition polymerization, and displayed fast gelation with thiolated hyaluronic acid (HA-SH) via a "click" thiol-ene reaction. HP-PBAE/HA-SH hydrogels showed tunable degradation profiles both in vitro and in vivo using diamines with different alkyl chain lengths and poly(ethylene glycol) diacrylates with varied PEG spacers. The hydrogels with optimized degradation profiles encapsulating ADSCs were used as injectable hydrogels to treat two different types of humanized excisional wounds - acute wounds with faster healing rates and diabetic wounds with slower healing and neo-tissue formation. The fast-degrading hydrogel showed accelerated wound closure in acute wounds, while the slow-degrading hydrogel showed better wound healing for diabetic wounds. The results demonstrate that the new HP-PBAE-based hydrogel in combination with ADSCs can be used as a well-controlled biodegradable skin substitute, which demonstrates a promising approach in the treatment of various types of skin wounds.

Biochemical characterization and substrate specificity of jojoba fatty acyl-CoA reductase and jojoba wax synthase.

PubMed

Miklaszewska, Magdalena; Banaś, Antoni

2016-08-01

Wax esters are used in industry for production of lubricants, pharmaceuticals and cosmetics. The only natural source of wax esters is jojoba oil. A much wider variety of industrial wax esters-containing oils can be generated through genetic engineering. Biotechnological production of tailor-made wax esters requires, however, a detailed substrate specificity of fatty acyl-CoA reductases (FAR) and wax synthases (WS), the two enzymes involved in wax esters synthesis. In this study we have successfully characterized the substrate specificity of jojoba FAR and jojoba WS. The genes encoding both enzymes were expressed heterologously in Saccharomyces cerevisiae and the activity of tested enzymes was confirmed by in vivo studies and in vitro assays using microsomal preparations from transgenic yeast. Jojoba FAR exhibited the highest in vitro activity toward 18:0-CoA followed by 20:1-CoA and 22:1-CoA. The activity toward other 11 tested acyl-CoAs was low or undetectable as with 18:2-CoA and 18:3-CoA. In assays characterizing jojoba WS combinations of 17 fatty alcohols with 14 acyl-CoAs were tested. The enzyme displayed the highest activity toward 14:0-CoA and 16:0-CoA in combination with C16-C20 alcohols as well as toward C18 acyl-CoAs in combination with C12-C16 alcohols. 20:1-CoA was efficiently utilized in combination with most of the tested alcohols. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Analysis of EDZ Development of Columnar Jointed Rock Mass in the Baihetan Diversion Tunnel

NASA Astrophysics Data System (ADS)

Hao, Xian-Jie; Feng, Xia-Ting; Yang, Cheng-Xiang; Jiang, Quan; Li, Shao-Jun

2016-04-01

Due to the time dependency of the crack propagation, columnar jointed rock masses exhibit marked time-dependent behaviour. In this study, in situ measurements, scanning electron microscope (SEM), back-analysis method and numerical simulations are presented to study the time-dependent development of the excavation damaged zone (EDZ) around underground diversion tunnels in a columnar jointed rock mass. Through in situ measurements of crack propagation and EDZ development, their extent is seen to have increased over time, despite the fact that the advancing face has passed. Similar to creep behaviour, the time-dependent EDZ development curve also consists of three stages: a deceleration stage, a stabilization stage, and an acceleration stage. A corresponding constitutive model of columnar jointed rock mass considering time-dependent behaviour is proposed. The time-dependent degradation coefficient of the roughness coefficient and residual friction angle in the Barton-Bandis strength criterion are taken into account. An intelligent back-analysis method is adopted to obtain the unknown time-dependent degradation coefficients for the proposed constitutive model. The numerical modelling results are in good agreement with the measured EDZ. Not only that, the failure pattern simulated by this time-dependent constitutive model is consistent with that observed in the scanning electron microscope (SEM) and in situ observation, indicating that this model could accurately simulate the failure pattern and time-dependent EDZ development of columnar joints. Moreover, the effects of the support system provided and the in situ stress on the time-dependent coefficients are studied. Finally, the long-term stability analysis of diversion tunnels excavated in columnar jointed rock masses is performed.

Expression of a putative dioxygenase gene adjacent to an insertion mutation is involved in the short internodes of columnar apples (Malus × domestica).

PubMed

Okada, Kazuma; Wada, Masato; Moriya, Shigeki; Katayose, Yuichi; Fujisawa, Hiroko; Wu, Jianzhong; Kanamori, Hiroyuki; Kurita, Kanako; Sasaki, Harumi; Fujii, Hiroshi; Terakami, Shingo; Iwanami, Hiroshi; Yamamoto, Toshiya; Abe, Kazuyuki

2016-11-01

Determining the molecular mechanism of fruit tree architecture is important for tree management and fruit production. An apple mutant 'McIntosh Wijcik', which was discovered as a bud mutation from 'McIntosh', exhibits a columnar growth phenotype that is controlled by a single dominant gene, Co. In this study, the mutation and the Co gene were analyzed. Fine mapping narrowed the Co region to a 101 kb region. Sequence analysis of the Co region and the original wild-type co region identified an insertion mutation of an 8202 bp long terminal repeat (LTR) retroposon in the Co region. Segregation analysis using a DNA marker based on the insertion polymorphism showed that the LTR retroposon was closely associated with the columnar growth phenotype. RNA-seq and RT-PCR analysis identified a promising Co candidate gene (91071-gene) within the Co region that is specifically expressed in 'McIntosh Wijcik' but not in 'McIntosh'. The 91071-gene was located approximately 16 kb downstream of the insertion mutation and is predicted to encode a 2-oxoglutarate-dependent dioxygenase involved in an unknown reaction. Overexpression of the 91071-gene in transgenic tobaccos and apples resulted in phenotypes with short internodes, like columnar apples. These data suggested that the 8202 bp retroposon insertion in 'McIntosh Wijcik' is associated with the short internodes of the columnar growth phenotype via upregulated expression of the adjacent 91071-gene. Furthermore, the DNA marker based on the insertion polymorphism could be useful for the marker-assisted selection of columnar apples.

Columnar lined Barrett's oesophagus.

PubMed

Sharma, Neel; Ho, Khek Yu

2015-12-01

Over the past few years, the definition of Barrett's oesophagus has altered with no real agreement on histological understanding. This article highlights the increasing confusion regarding Barrett's oesophagus with a focus on the all-too-frequently ignored aspect of the columnar lined oesophagus.

Multicolor Upconversion Nanoparticles for Protein Conjugation

PubMed Central

Wilhelm, Stefan; Hirsch, Thomas; Patterson, Wendy M.; Scheucher, Elisabeth; Mayr, Torsten; Wolfbeis, Otto S.

2013-01-01

We describe the preparation of monodisperse, lanthanide-doped hexagonal-phase NaYF4 upconverting luminescent nanoparticles for protein conjugation. Their core was coated with a silica shell which then was modified with a poly(ethylene glycol) spacer and N-hydroxysuccinimide ester groups. The nanoparticles were characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and dynamic light scattering. The N-hydroxysuccinimide ester functionalization renders them highly reactive towards amine nucleophiles (e.g., proteins). We show that such particles can be conjugated to proteins. The protein-reactive UCLNPs and their conjugates to streptavidin and bovine serum albumin display multicolor emissions upon 980-nm continuous wave laser excitation. Surface plasmon resonance studies were carried out to prove bioconjugation and to compare the affinity of the particles for proteins immobilized on a thin gold film. PMID:23606910

Water hardness influences Flavobacterium columnare pathogenesis in channel catfish

USDA-ARS?s Scientific Manuscript database

Studies were conducted to determine aspects of water chemistry responsible for large differences in pathogenesis and mortality rates in challenges of channel catfish Ictalurus punctatus with Flavobacterium columnare; challenges were conducted in water supplying the Stuttgart National Aquaculture Res...

Formalin treatment of Trichondina sp. reduced Flavobacterium columnare infection in tilapia

USDA-ARS?s Scientific Manuscript database

Bacterium Flavobacterium columnare and protozoan Trichodina spp. are common pathogens of cultured fish. Recent studies on parasite-bacterium interaction show evidence that concurrent infections increase severity of some infectious diseases, especially bacterial diseases. The effect of parasite treat...

[Effects of Guilin Watermelon Frost on the mRNA expressions of basic fibroblast growth factor in patients with uterine cervical columnar ectopy].

PubMed

Qiu-Yan, Jiang; Jin-Ling, Song; Hai-Xia, Mo

2012-01-01

To study the molecular biological effects of Guilin Watermelon Frost (GWF) on the mRNA expressions of basic fibroblast growth factor (bFGF) in patients with uterine uterine cervical columnar ectopy. One hundred and sixty patients with uterine cervical columnar ectopy were assigned to two groups by the random digit table. Patients in the treatment group were treated with local spray of GWF, while those in the control group were local applied with bFGF-collagen sponge. The mRNA expressions of bFGF of the uterine tissue were detected in the two groups before and after treatment using RT-PCR. Before treatment the mRNA expression of bFGF in the uterine cervical columnar ectopy was 0.55 +/- 0.10 in the treatment group and 0.58 +/- 0.13 in the control group, without insignificant difference (P > 0.05). After treatment it significantly increased in the two groups, being 0.82 +/- 0.17 and 0.78 +/- 0.15 respectively, showing statistical difference from before treatment (P < 0.01). But no statistical difference existed between the two groups after treatment (P > 0.05). GWF showed enhancement on the mRNA expressions of bFGF in patients with uterine cervical columnar ectopy.

Electron beam physical vapor deposition of YSZ electrolyte coatings for SOFCs

NASA Astrophysics Data System (ADS)

He, Xiaodong; Meng, Bin; Sun, Yue; Liu, Bochao; Li, Mingwei

2008-09-01

YSZ electrolyte coatings were prepared by electron beam physical vapor deposition (EB-PVD) at a high deposition rate of up to 1 μm/min. The YSZ coating consisted of a single cubic phase and no phase transformation occurred after annealing treatment at 1000 °C. A typical columnar structure was observed in this coating by SEM and feather-like characteristics appeared in every columnar grain. In columnar grain boundaries there were many micron-sized gaps and pores. In TEM image, many white lines were found, originating from the alignment of nanopores existing within feather-like columnar grains. The element distribution along the cross-section of the coating was homogeneous except Zr with a slight gradient. The coating exhibited a characteristic anisotropic behavior in electrical conductivity. In the direction perpendicular to coating surface the electrical conductivity was remarkably higher than that in the direction parallel to coating surface. This mainly attributed to the typical columnar structure for EB-PVD coating and the existence of many grain boundaries along the direction parallel to coating surface. For as-deposited coating, the gas permeability coefficient of 9.78 × 10 -5 cm 4 N -1 s -1 was obtained and this value was close to the critical value of YSZ electrolyte layer required for solid oxide fuel cell (SOFC) operation.

Gene expression analysis between planktonic and biofilm states of Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry continual efforts to better understand basic mechanisms that contribute to disease ...

Sickeningly sweet: L-rhamnose stimulates Flavobacterium columnare biofilm formation and virulence

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry continual efforts to better understand basic mechanisms that contribute to disease ...

The carbohydrate L-rhamnose promotes biofilm formation which enhances Flavobacterium columnare virulence

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry, continual efforts to better understand basic mechanisms that contribute to disease...

Conformationally restrained aromatic analogues of fosmidomycin and FR900098.

PubMed

Kurz, Thomas; Schlüter, Katrin; Pein, Miriam; Behrendt, Christoph; Bergmann, Bärbel; Walter, Rolf D

2007-07-01

The synthesis and in-vitro antimalarial activity of conformationally restrained bis(pivaloyloxymethyl) ester analogues of the natural product fosmidomycin is presented. In contrast to alpha-aryl-substituted analogues, conformationally restrained aromatic analogues exhibit only moderate in-vitro antimalarial activity against the chloroquine-sensitive strain 3D7 of Plasmodium falciparum. The most active derivative displays an IC(50) value of 47 microM.

Columnar and Equiaxed Solidification of Al-7 wt.% Si Alloys in Reduced Gravity in the Framework of the CETSOL Project

NASA Astrophysics Data System (ADS)

Zimmermann, G.; Sturz, L.; Nguyen-Thi, H.; Mangelinck-Noel, N.; Li, Y. Z.; Gandin, C.-A.; Fleurisson, R.; Guillemot, G.; McFadden, S.; Mooney, R. P.; Voorhees, P.; Roosz, A.; Ronaföldi, A.; Beckermann, C.; Karma, A.; Chen, C.-H.; Warnken, N.; Saad, A.; Grün, G.-U.; Grohn, M.; Poitrault, I.; Pehl, T.; Nagy, I.; Todt, D.; Minster, O.; Sillekens, W.

2017-08-01

During casting, often a dendritic microstructure is formed, resulting in a columnar or an equiaxed grain structure, or leading to a transition from columnar to equiaxed growth (CET). The detailed knowledge of the critical parameters for the CET is important because the microstructure affects materials properties. To provide unique data for testing of fundamental theories of grain and microstructure formation, solidification experiments in microgravity environment were performed within the European Space Agency Microgravity Application Promotion (ESA MAP) project Columnar-to-Equiaxed Transition in SOLidification Processing (CETSOL). Reduced gravity allows for purely diffusive solidification conditions, i.e., suppressing melt flow and sedimentation and floatation effects. On-board the International Space Station, Al-7 wt.% Si alloys with and without grain refiners were solidified in different temperature gradients and with different cooling conditions. Detailed analysis of the microstructure and the grain structure showed purely columnar growth for nonrefined alloys. The CET was detected only for refined alloys, either as a sharp CET in the case of a sudden increase in the solidification velocity or as a progressive CET in the case of a continuous decrease of the temperature gradient. The present experimental data were used for numerical modeling of the CET with three different approaches: (1) a front tracking model using an equiaxed growth model, (2) a three-dimensional (3D) cellular automaton-finite element model, and (3) a 3D dendrite needle network method. Each model allows for predicting the columnar dendrite tip undercooling and the growth rate with respect to time. Furthermore, the positions of CET and the spatial extent of the CET, being sharp or progressive, are in reasonably good quantitative agreement with experimental measurements.

Does flat epithelial atypia have rounder nuclei than columnar cell change/hyperplasia? A morphometric approach to columnar cell lesions of the breast.

PubMed

Yamashita, Yoshiko; Ichihara, Shu; Moritani, Suzuko; Yoon, Han-Seung; Yamaguchi, Masahiro

2016-06-01

Columnar cell lesions of the breast encompass columnar cell change/hyperplasia (CCC/CCH) and flat epithelial atypia (FEA). These have attracted researchers because emerging data suggest that FEA may represent the earliest histologically detectable non-obligate precursor of breast cancer. However, it is occasionally difficult to distinguish FEA from CCC/CCH because of similar histology. Although the nuclei of FEA are frequently described as relatively round compared with those of CCC/CCH, there are few morphometric studies to support this statement. The aim of this study was to provide objective data as to the nuclear shape in columnar cell lesions. As a shape descriptor, we adopted ellipticity that is defined by the formula 2b/2a, where a is the length of the long axis of the ellipse and b is the length of the short axis. Contrary to circularity, ellipticity reflects the overall configuration of an ellipse irrespective of surface irregularity. Our image analysis included generating whole slide images, extracting glandular cell nuclei, measuring nuclear ellipticity, and superimposing graded colors based on execution of results on the captured images. A total of 7917 nuclei extracted from 22 FEA images and 5010 nuclei extracted from 13 CCC/CCH images were analyzed. There was a significant difference in nuclear roundness between FEA and CCC/CCH with mean ellipticity values of 0.723 and 0.679, respectively (p < 0.001, Welch's t test). Furthermore, FEA with malignancy had significantly rounder nuclei than FEA without malignancy (p < 0.001). Our preliminary results suggest that nuclear ellipticity is a key parameter in reproducibly classifying columnar cell lesions of the breast.

Transitional basal cells at the squamous-columnar junction generate Barrett's oesophagus.

PubMed

Jiang, Ming; Li, Haiyan; Zhang, Yongchun; Yang, Ying; Lu, Rong; Liu, Kuancan; Lin, Sijie; Lan, Xiaopeng; Wang, Haikun; Wu, Han; Zhu, Jian; Zhou, Zhongren; Xu, Jianming; Lee, Dong-Kee; Zhang, Lanjing; Lee, Yuan-Cho; Yuan, Jingsong; Abrams, Julian A; Wang, Timothy C; Sepulveda, Antonia R; Wu, Qi; Chen, Huaiyong; Sun, Xin; She, Junjun; Chen, Xiaoxin; Que, Jianwen

2017-10-26

In several organ systems, the transitional zone between different types of epithelium is a hotspot for pre-neoplastic metaplasia and malignancy, but the cells of origin for these metaplastic epithelia and subsequent malignancies remain unknown. In the case of Barrett's oesophagus, intestinal metaplasia occurs at the gastro-oesophageal junction, where stratified squamous epithelium transitions into simple columnar cells. On the basis of a number of experimental models, several alternative cell types have been proposed as the source of this metaplasia but in all cases the evidence is inconclusive: no model completely mimics Barrett's oesophagus in terms of the presence of intestinal goblet cells. Here we describe a transitional columnar epithelium with distinct basal progenitor cells (p63 + KRT5 + KRT7 + ) at the squamous-columnar junction of the upper gastrointestinal tract in a mouse model. We use multiple models and lineage tracing strategies to show that this squamous-columnar junction basal cell population serves as a source of progenitors for the transitional epithelium. On ectopic expression of CDX2, these transitional basal progenitors differentiate into intestinal-like epithelium (including goblet cells) and thereby reproduce Barrett's metaplasia. A similar transitional columnar epithelium is present at the transitional zones of other mouse tissues (including the anorectal junction) as well as in the gastro-oesophageal junction in the human gut. Acid reflux-induced oesophagitis and the multilayered epithelium (believed to be a precursor of Barrett's oesophagus) are both characterized by the expansion of the transitional basal progenitor cells. Our findings reveal a previously unidentified transitional zone in the epithelium of the upper gastrointestinal tract and provide evidence that the p63 + KRT5 + KRT7 + basal cells in this zone are the cells of origin for multi-layered epithelium and Barrett's oesophagus.

The avian prechordal head region: a morphological study.

PubMed Central

Seifert, R; Jacob, M; Jacob, H J

1993-01-01

The axial mesoderm of the anterior head region was investigated in young chick and quail embryos by light and electron microscopy. Semithin sections showed that the axial head mesoderm consists of the head process and prechordal mesoderm. At the anterior end of the prechordal mesoderm, a group of columnar epithelial cells formed a pit-like structure. The bases of these columnar cells extended to the neural plate, thus limiting the prechordal mesoderm anteriorly. The cells lining the pit-like structure at its anterior end joined a cell accumulation made up of cells of mesenchymal character. Electron microscopy revealed that the columnar cells forming the pit-like structure were covered by a basal lamina which was discontinuous on its anterior aspect. No basal lamina was recognisable between the columnar epithelial cells and mesenchymal cells joining them anteriorly. The columnar epithelial cells bordering the prechordal mesoderm anteriorly were therefore assumed to be part of the endodermal germ layer. In agreement with the findings of other authors, it is proposed to term these axially located columnar cells of the endoderm the prechordal plate and to distinguish them from the prechordal mesoderm arising during gastrulation. For the mesenchymal cell accumulation anterior to the prechordal plate, participation in the formation of the prosencephalic mesenchyme is assumed. This implies that the definitive endodermal germ layer, like the ectodermal one represented by the neural crest, may also be able to contribute to mesenchyme formation in the head. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 PMID:8270478

Effect of anisotropy and texture on the low cycle fatigue behavior of Inconel 718 processed via electron beam melting

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

Kirka, Michael M.; Greeley, Duncan A.; Hawkins, Charles S.

Here in this study, the impact of texture (columnar/equiax grain structure) and influence of material orientation on the low cycle fatigue (LCF) behavior of hot isostatic pressed (HIP) and heat-treated Inconel 718 fabricated through electron beam melting (EBM) is investigated. Material was tested both parallel and perpendicular (transverse) to the build direction. In all instances, the EBM HIP and heat-treated Inconel 718 performed similarly or exceeded the LCF life of wrought Inconel 718 plate and bar stock under fully reversed strain-controlled loading at 650 °C. Amongst the textures, the columnar grains oriented parallel to the build direction exhibited the highestmore » life on average compared to the transverse columnar and equiax EBM material. Further, in relation to the reference wrought material the parallel columnar grain material exhibited a greater life. While a negligible life difference was observed in the equiax grained material between the two orientations, a consistently lower accumulated inelastic strain was measured for the material loaded parallel to the build direction than the transverse orientation. Failure of the parallel columnar material occurred in a transgranular manner with cracks emanating from the surface whereas the transverse columnar material failed in a intergranular manner, with crack growth occurring through repeated rupture of oxide at the crack-tip. Finally, in the case of the equiax material, an influence of material orientation was not observed on the failure mechanism with crack propagation occurring through a combination of debonded/cracked carbides and void formation along twin boundaries resulting in a mixture of intergranular and transgranular crack propagation.« less

Lytic bacteriophages specific to Flavobacterium columnare rescue catfish, Clarias batrachus (Linn.) from columnaris disease.

PubMed

Prasad, Yogendra; Arpana; Kumar, Dinesh; Sharma, A K

2011-03-01

This investigation was aimed to find out appropriate strategy against antibiotic resistant bacterial fish pathogen, F. columnare. This pathogen was found persistently associated with fishes causing columnaris disease and ensuing mass mortality in hatchery and culture system of Sub - Himalayan region. Nine lytic F. columnare phages (FCP1 - FCP9) specific to its fifteen isolates were isolated from the water and bottom sediments of various geo-climatic regions of North India. The F. columnare phage FCP1 (made of hexagonal head and non contractile long tail belonging to family Podovariedae, a member of DNA virus) exhibited broader host range to lyse 9 out of 15 isolates of F. columnare. Therapeutic ability of FCP1 phage was assessed in C. batrachus inoculated intramuscularly (im) with virulent bacterial isolate FC8 and post inoculated (PI) with FCP1 phage (@ 10(8) : 10(6):: cfu : pfu) through intramuscular (im), immersion (bath) and oral (phage impregnated feed) treatment. Significant (p < 0.001) reduction (less than 10(-3) cfu ml(-1)) in host bacterium in the sera, gill, liver and kidney of challenged fishes was noted after 6 hr of phage treatment. Quantum of phage played a significant role in bringing down bacterial population as in the sera of dose 1 (@ 4.55 x 10(6) pfu ml(-1)) and dose 2 (@ 9.15 x 10(6) pfu ml(-1)) treated fishes mean log10 cfu value reduced by 3 logs (58.39%) and 5 logs (73.77%) at 96 hr, respectively. Phage treatment led to disappearance of gross symptoms, negative bacteriological test, detectable phage and 100% survival in experimentally infected C. batrachus. Result of this study provides evidence of profound lytic impact of FCP1 phage and represents its interesting therapeutic importance against antibiotic resistant F. columnare.

Effect of anisotropy and texture on the low cycle fatigue behavior of Inconel 718 processed via electron beam melting

DOE PAGES

Kirka, Michael M.; Greeley, Duncan A.; Hawkins, Charles S.; ...

2017-09-11

Here in this study, the impact of texture (columnar/equiax grain structure) and influence of material orientation on the low cycle fatigue (LCF) behavior of hot isostatic pressed (HIP) and heat-treated Inconel 718 fabricated through electron beam melting (EBM) is investigated. Material was tested both parallel and perpendicular (transverse) to the build direction. In all instances, the EBM HIP and heat-treated Inconel 718 performed similarly or exceeded the LCF life of wrought Inconel 718 plate and bar stock under fully reversed strain-controlled loading at 650 °C. Amongst the textures, the columnar grains oriented parallel to the build direction exhibited the highestmore » life on average compared to the transverse columnar and equiax EBM material. Further, in relation to the reference wrought material the parallel columnar grain material exhibited a greater life. While a negligible life difference was observed in the equiax grained material between the two orientations, a consistently lower accumulated inelastic strain was measured for the material loaded parallel to the build direction than the transverse orientation. Failure of the parallel columnar material occurred in a transgranular manner with cracks emanating from the surface whereas the transverse columnar material failed in a intergranular manner, with crack growth occurring through repeated rupture of oxide at the crack-tip. Finally, in the case of the equiax material, an influence of material orientation was not observed on the failure mechanism with crack propagation occurring through a combination of debonded/cracked carbides and void formation along twin boundaries resulting in a mixture of intergranular and transgranular crack propagation.« less

Antibacterial activity of acylglucinol derivatives against Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Columnaris disease is one of the most common bacterial diseases of pond-raised channel catfish (Ictalurus punctatus) in the southeastern United States of America. The Gram-negative, rod-shaped bacterium Flavobacterium columnare is the cause of columnaris disease. Direct economic losses to catfish pr...

Ungeremine and its hemisynthetic analogues as bactericides against Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

The Gram-negative bacterium Flavobacterium columunare is the cause of colmunaris disease in channel catfish (Ictalurus punctatus). In a previous study, the betaine-type alkaloid ungeremine, 1 obtained from Pancratium maritimum L. was found to have strong antibacterial activity against F. columnare. ...

Assessment of Flavobacterium columnare from golden shiners Notemingonus crysoleucas subject to crowding stress

USDA-ARS?s Scientific Manuscript database

Intensive aquaculture practices and exposure to environmental stressors can trigger outbreaks of Flavobacterium columnare, a bacterial pathogen that causes columnaris disease in commercially important fish including Golden Shiners. A rapid assessment of the bacterial load is essential to prevent out...

Method for fabricating high aspect ratio structures in perovskite material

DOEpatents

Karapetrov, Goran T.; Kwok, Wai-Kwong; Crabtree, George W.; Iavarone, Maria

2003-10-28

A method of fabricating high aspect ratio ceramic structures in which a selected portion of perovskite or perovskite-like crystalline material is exposed to a high energy ion beam for a time sufficient to cause the crystalline material contacted by the ion beam to have substantially parallel columnar defects. Then selected portions of the material having substantially parallel columnar defects are etched leaving material with and without substantially parallel columnar defects in a predetermined shape having high aspect ratios of not less than 2 to 1. Etching is accomplished by optical or PMMA lithography. There is also disclosed a structure of a ceramic which is superconducting at a temperature in the range of from about 10.degree. K. to about 90.degree. K. with substantially parallel columnar defects in which the smallest lateral dimension of the structure is less than about 5 microns, and the thickness of the structure is greater than 2 times the smallest lateral dimension of the structure.

Constitutive Modeling of Superalloy Single Crystals and Directionally Solidified Materials

NASA Technical Reports Server (NTRS)

Walker, K. P.; Jordan, E. H.

1985-01-01

A unified viscoplastic constitutive relation based on crystallographic slip theory was developed for the deformation analysis of nickel base face centered cubic superalloy single crystals at elevated temperature. The single crystal theory is embedded in a self consistent method to derive a constitutive relation for a directionally solidified material comprised of a polycrystalline aggregate of columnar cylindrical grains. One of the crystallographic axes of the cylindrical crystals points in the columnar direction while the remaining crystallographic axes are oriented at random in the basal plane perpendicular to the columnar direction. These constitutive formulations are coded in FORTRAN for use in nonlinear finite element and boundary element programs.

Influence of native catfish mucus on Flavobacterium columnare growth and proteolytic activity

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare causes columnaris disease of farmed and wild freshwater fish. Skin mucus is an important factor in early stages of columnaris pathogenesis, albeit little studied. Our objectives were to 1) characterize the terminal glycosylation pattern (TGP) of catfish mucus, 2) determine t...

Kaolinitic clay protects against Flavobacterium columnare infection in channel catfish Ictalurus punctatus (Rafinesque)

USDA-ARS?s Scientific Manuscript database

Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem worldwide in aquaculture settings. Despite the far-reaching negative impacts of columnaris disease, safe and efficacious preventatives and curatives for this disease remain limited. In th...

More than just antibodies: protective mechanisms of a mucosal vaccine against fish pathogen Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

A recently developed attenuated vaccine (17-23) for Flavobacterium columnare has been demonstrated to provide superior protection for channel catfish, Ictalurus punctatus, against genetically diverse columnaris isolates. First, we were interested in elucidating the host responses generated by a viru...

Evaluation of the antibody response to the LV-359-01 strain of flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare, the causative agent of columnaris disease produces substantial mortality worldwide among numerous freshwater farmed finfish species. As aquaculture production continues to increase the frequency of columnaris disease will only continue to rise. Add to this an increase in re...

Extremophile extracts and enhancement techniques show promise for the development of a live vaccine against Flavobacterium columnare

USGS Publications Warehouse

Powell, D.B.; Palm, R.C.; MacKenzie, A.P.; Winton, J.R.

2009-01-01

The effects of temperature, ionic strength, and new cryopreservatives derived from polar ice bacteria were investigated to help accelerate the development of economical, live attenuated vaccines for aquaculture. Extracts of the extremophile Gelidibacter algens functioned very well as part of a lyophilization cryoprotectant formulation in a 15-week storage trial. The bacterial extract and trehalose additives resulted in significantly higher colony counts of columnaris bacteria (Flavobacterium columnare) compared to nonfat milk or physiological saline at all time points measured. The bacterial extract combined with trehalose appeared to enhance the relative efficiency of recovery and growth potential of columnaris in flask culture compared to saline, nonfat milk, or trehalose-only controls. Pre-lyophilization temperature treatments significantly affected F. columnare survival following rehydration. A 30-min exposure at 0 ??C resulted in a 10-fold increase in bacterial survival following rehydration compared to mid-range temperature treatments. The brief 30 and 35 ??C pre-lyophilization exposures appeared to be detrimental to the rehydration survival of the bacteria. The survival of F. columnare through the lyophilization process was also strongly affected by changes in ionic strength of the bacterial suspension. Changes in rehydration constituents were also found to be important in promoting increased survival and growth. As the sodium chloride concentration increased, the viability of rehydrated F. columnare decreased. ?? 2009 Elsevier Inc.

Exploring Redox States, Doping and Ordering of Electroactive Star-Shaped Oligo(aniline)s.

PubMed

Mills, Benjamin M; Fey, Natalie; Marszalek, Tomasz; Pisula, Wojciech; Rannou, Patrice; Faul, Charl F J

2016-11-14

We have prepared a simple star-shaped oligo(aniline) (TDPB) and characterised it in detail by MALDI-TOF MS, UV/Vis/NIR spectroscopy, time-dependent DFT, cyclic voltammetry and EPR spectroscopy. TDPB is part of an underdeveloped class of π-conjugated molecules with great potential for organic electronics, display and sensor applications. It is redox active and reacts with acids to form radical cations. Acid-doped TDPB shows behaviour similar to discotic liquid crystals, with X-ray scattering investigations revealing columnar self-assembled arrays. The combination of unpaired electrons and supramolecular stacking suggests that star-shaped oligo(aniline)s like TDPB have the potential to form conducting nanowires and organic magnetic materials. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

NASA combined file postings statistics based on NASA Thesaurus, January 1968 - January 1991

NASA Technical Reports Server (NTRS)

1991-01-01

The NASA Combined File Postings Statistics is published semiannually (January and July). This alphabetical listing of postable subject terms contained in the NASA Thesaurus is used to display the number of postings (documents) indexed by each subject term from 1968 to data. The postings totals per term are separated by announcement or other media into STAR, IAA, NLN, and OTHER columnar entries covering the NASA document collection (1968 to date). Over 595,000 book postings for NALNET Books held by NASA Libraries are included under the NLN column. CSTAR postings as well as some previously unreported series are listed under the 'other' column. The distribution of 18,748,083 postings among the 17,304 Thesaurus terms is tabulated on the last page of Combined File Postings Statistics.

Investigations of electromagnetic scattering by columnar ice crystals

NASA Technical Reports Server (NTRS)

Weil, H.; Senior, T. B. A.

1976-01-01

An integral equation approach was developed to determine the scattering and absorption of electromagnetic radiation by thin walled cylinders of arbitrary cross-section and refractive index. Based on this method, extensive numerical data was presented at infrared wavelengths for hollow hexagonal cross section cylinders which simulate columnar sheath ice crystals.

Compounds from Terminalli brownii extracts with toxicity against the fish pathogenic bacterium Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

The pond-raised channel catfish (Ictalurus punctatus) industry in the United States of America can incur losses of over a $100 million annually due to bacterial diseases including columnaris disease caused by Flavobacterium columnare. One management approach available to catfish producers is the use...

Columnaris (Flavobacterium columnare) challenge using fathead minnows (Pimephales promelas) in an ultra-low flow system

USDA-ARS?s Scientific Manuscript database

Arkansas baitfish farms routinely struggle with columnaris disease, which is caused by Flavobacterium columnare. Columnaris is ubiquitous in fathead minnows (Pimephales promelas) especially after harvest while they are being held in vats and during the transport prior to being sold. Columnaris disea...

The stress hormone cortisol: a (co)regulator of biofilm formation in Flavobacterum columnare?

USDA-ARS?s Scientific Manuscript database

Previously, we demonstrated a direct effect of cortisol on Flavobacterium columnare, a notorious fish pathogenic bacterium, engendering a new perspective to bacteria-host communication in aquaculture. As stressed fish harbour increased cortisol levels in the skin and gill mucus, highly virulent F. c...

The type IX secretion system is required for virulence of the fish pathogen Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes...

In vitro comparisons of the inhibitory activity of florfenicol copper sulfate and potassium permanganate towards Aeromonas hydrophila and Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Aeromonas hydrophila and Flavobacterium columnare, the etiological agents of motile aeromonas septicemia (MAS) and columnaris disease, respectively, have been recently causing crippling moralities to the sunshine bass, Morone chrysops female X Morone saxatilis male (Percichthyidae), industry in the ...

Effectiveness of copper sulfate and potassium permanganate on channel catfish infected with Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Copper sulfate (CuSO4) and potassium permanganate (KMnO4) were evaluated for their effectiveness to curtail mortality and decrease bacterial load in fish tissues and water in channel catfish Ictalurus punctatus naturally infected with Flavobacterium columnare, the causative agent of columnaris. Fis...

Quality control ranges for testing broth microdilution susceptibility of Flavobacterium columnare and F. psychrophilium to nine antimicrobials

USDA-ARS?s Scientific Manuscript database

A multi-laboratory broth microdilution method trial was performed to standardize the specialized test conditions required for fish pathogens Flavobacterium columnare and F. pyschrophilum. Nine laboratories tested the quality control (QC) strains Escherichia coli ATCC 25922 and Aeromonas salmonicid...

More than just antibodies: protective mechanisms of a muscosal vaccine against fish pathogen Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

A recently developed attenuated vaccine (17-23) for Flavobacterium columnare has been demonstrated to provide superior protection for channel catfish, Ictalurus punctatus, against genetically diverse columnaris isolates (Mohammed et al. 2013). We were interested in examining the mechanisms of this p...

Evaluating innate resistance to Flavobacterium Columnare in rainbow trout (Oncorhynchus mykiss)

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare (Fc) is the causative agent for columnaris disease and a problem for several fish species. Recently, columnaris has been recognized as an emerging problem in farmed trout cultured within the Hagerman valley of Idaho. A long term breeding program at the NCCCWA has produced ...

A high-performance renewable thermosetting resin derived from eugenol.

PubMed

Harvey, Benjamin G; Sahagun, Christopher M; Guenthner, Andrew J; Groshens, Thomas J; Cambrea, Lee R; Reams, Josiah T; Mabry, Joseph M

2014-07-01

A renewable bisphenol, 4,4'-(butane-1,4-diyl)bis(2-methoxyphenol), was synthesized on a preparative scale by a solvent-free, Ru-catalyzed olefin metathesis coupling reaction of eugenol followed by hydrogenation. After purification, the bisphenol was converted to a new bis(cyanate) ester by standard techniques. The bisphenol and cyanate ester were characterized rigorously by NMR spectroscopy and single-crystal X-ray diffraction studies. After complete cure, the cyanate ester exhibited thermal stability in excess of 350 °C and a glass transition temperature (Tg ) of 186 °C. As a result of the four-carbon chain between the aromatic rings, the thermoset displayed a water uptake of only 1.8% after a four day immersion in 85 °C water. The wet Tg of the material (167 °C) was only 19 °C lower than the dry Tg , and the material showed no significant degradation as a result of the water treatment. These results suggest that this resin is well suited for maritime environments and provide further evidence that full-performance resins can be generated from sustainable feedstocks. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Volatile Ester Formation in Roses. Identification of an Acetyl-Coenzyme A. Geraniol/Citronellol Acetyltransferase in Developing Rose Petals1

PubMed Central

Shalit, Moshe; Guterman, Inna; Volpin, Hanne; Bar, Einat; Tamari, Tal; Menda, Naama; Adam, Zach; Zamir, Dani; Vainstein, Alexander; Weiss, David; Pichersky, Eran; Lewinsohn, Efraim

2003-01-01

The aroma of roses (Rosa hybrida) is due to more than 400 volatile compounds including terpenes, esters, and phenolic derivatives. 2-Phenylethyl acetate, cis-3-hexenyl acetate, geranyl acetate, and citronellyl acetate were identified as the main volatile esters emitted by the flowers of the scented rose var. “Fragrant Cloud.” Cell-free extracts of petals acetylated several alcohols, utilizing acetyl-coenzyme A, to produce the corresponding acetate esters. Screening for genes similar to known plant alcohol acetyltransferases in a rose expressed sequence tag database yielded a cDNA (RhAAT1) encoding a protein with high similarity to several members of the BAHD family of acyltransferases. This cDNA was functionally expressed in Escherichia coli, and its gene product displayed acetyl-coenzyme A:geraniol acetyltransferase enzymatic activity in vitro. The RhAAT1 protein accepted other alcohols such as citronellol and 1-octanol as substrates, but 2-phenylethyl alcohol and cis-3-hexen-1-ol were poor substrates, suggesting that additional acetyltransferases are present in rose petals. The RhAAT1 protein is a polypeptide of 458 amino acids, with a calculated molecular mass of 51.8 kD, pI of 5.45, and is active as a monomer. The RhAAT1 gene was expressed exclusively in floral tissue with maximum transcript levels occurring at stage 4 of flower development, where scent emission is at its peak. PMID:12692346

Preclinical studies of steroid-linked nitrosoureas in murine pancreatic adenocarcinoma PANO2.

PubMed

Papageorgiou, A; Lialiaris, Th; Stergiou, E; Stergiou, I; Tsigris, C; Kourti, A; Geromichalos, G; Stravoravdi, P; Trafalis, D; Athanassiou, A E; Pitsas, A; Camoutsis, Ch

2008-01-01

In earlier studies, this laboratory carried out research on the synthesis and anticancer evaluation of hybrid compounds, which combine two molecules in one such as homo-aza-steroidal esters (HASE) of carboxylic derivatives of N, N-bis (2-chloroethyl) aniline. In this combination, steroidal hormones are employed as carriers for transporting the alkylating agents to specific targeted tissues. Aiming to continue our research, we used alkylating agents, as nitrosoureas, instead of nitrogen mustards. In this work the N-[N- (2-chloroethyl)-N-nitroso-carbomoyl]-L-alanine (CNC-ala) has been used and was bound to 7 newly synthesized modified steroidal esters (carrier molecule) of nitrosourea and the hybrid molecules were tested for antitumor activity against PANO2 murine pancreatic adenocarcinoma. PANO2 adenocarcinoma was used in this study. C57Bl mice were used for chemotherapy evaluation. The activity was assessed from the inhibition of tumor growth and the oncostatic parameter T/C %. The antitumor activity displayed by 7 hybrid steroidal esters of nitrosourea was quite interesting. It was able to discern 4 of 7 compounds that exhibited considerable antitumor activity, increasing the lifespan of the tumor-bearing mice by inhibiting the tumor growth. The comparative study of 7 newly synthesized hybrid steroidal esters of nitrosourea shows that the antitumor effects of compound 7, which has an enlarged (7 carbon atoms) A-lactamic ring and nitrosourea esterified at the position 17, which seems to be the most appropriate for the connection of a DNA cross-linking amino acid derivative is superior.

Processing of alnico permanent magnets by advanced directional solidification methods

DOE PAGES

Zou, Min; Johnson, Francis; Zhang, Wanming; ...

2016-07-05

Advanced directional solidification methods have been used to produce large (>15 cm length) castings of Alnico permanent magnets with highly oriented columnar microstructures. In combination with subsequent thermomagnetic and draw thermal treatment, this method was used to enable the high coercivity, high-Titanium Alnico composition of 39% Co, 29.5% Fe, 14% Ni, 7.5% Ti, 7% Al, 3% Cu (wt%) to have an intrinsic coercivity (H ci) of 2.0 kOe, a remanence (B r) of 10.2 kG, and an energy product (BH) max of 10.9 MGOe. These properties compare favorably to typical properties for the commercial Alnico 9. Directional solidification of highermore » Ti compositions yielded anisotropic columnar grained microstructures if high heat extraction rates through the mold surface of at least 200 kW/m 2 were attained. This was achieved through the use of a thin walled (5 mm thick) high thermal conductivity SiC shell mold extracted from a molten Sn bath at a withdrawal rate of at least 200 mm/h. However, higher Ti compositions did not result in further increases in magnet performance. Images of the microstructures collected by scanning electron microscopy (SEM) reveal a majority α phase with inclusions of secondary αγ phase. Transmission electron microscopy (TEM) reveals that the α phase has a spinodally decomposed microstructure of FeCo-rich needles in a NiAl-rich matrix. In the 7.5% Ti composition the diameter distribution of the FeCo needles was bimodal with the majority having diameters of approximately 50 nm with a small fraction having diameters of approximately 10 nm. The needles formed a mosaic pattern and were elongated along one <001> crystal direction (parallel to the field used during magnetic annealing). Cu precipitates were observed between the needles. Regions of abnormal spinodal morphology appeared to correlate with secondary phase precipitates. The presence of these abnormalities did not prevent the material from displaying superior magnetic properties in the 7.5% Ti composition. As a result, higher Ti compositions did not display the preferred spinodal microstructure, explaining their inferior magnetic properties.« less

Bioassay-directed isolation and evaluation of Harmine from the terrestrial plant Peganum harmala L. for antibacterial activity against Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

The antibacterial activities of crude extracts obtained from the aerial portions and roots of Peganum harmala L. were evaluated against the common fish pathogenic bacteria species Edwardsiella ictaluri, Flavobacterium columnare, and Streptococcus iniae using a rapid bioassay. Enteric septicemia of c...

The effect of high total ammonia concentration on the survival of channel catfish experimentally infected with Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Although it is generally accepted that elevated ammonia levels in the water increase mortalities of Flavobacterium columnare infected fish, recent observation at our laboratory indicated otherwise. Two trials were conducted to determine the effect of a single immersion flush treatment of total ammo...

Development of sequence-tagged site markers linked to the pillar growth type in peach (Prunus persica)

USDA-ARS?s Scientific Manuscript database

In peach [Prunus persica (L.) Batsch], trees showing columnar [also termed pillar or broomy] growth habit are of interest for high density production systems. While the selection of the columnar homozygote (pillar) phenotype (brbr) can be carried out prior to field planting, the intermediate hetero...

There must be something in the water (for F. columnare pathogenesis)

USDA-ARS?s Scientific Manuscript database

Why can we routinely produce columnaris infections in our lab, while the lab on the other side of the ditch can't? Anecdotal reports suggest that tannins may inhibit F. columnare. Do tannins in their water prevent this, or are other water chemistry parameters involved? In the first experiment, tw...

Identification of genes encoding the type IX secretion system and secreted proteins in Flavobacterium columnare IA-S-4

USDA-ARS?s Scientific Manuscript database

Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes...

Comparative effects of copper sulfate or potassium permanganate on channel catfish concurrently infected with Flavobacterium columnare and Ichthyobodo necator

USDA-ARS?s Scientific Manuscript database

An opportunistic study was conducted to determine the effects of two chemical therapeutants on channel catfish (CCF) Ictalurus punctatus concurrently infected Flavobacterium columnare and Ichthyobodo necator. Copper sulfate (CuSO4) and potassium permanganate (KMnO4) were investigated for their abil...

Characterization of tlr-4 in fathead minnow challenged with columnaris (flavobacterium columnare) in an ultra-low flow system

USDA-ARS?s Scientific Manuscript database

Columnaris disease, caused by the bacteria Flavobacterium columnare, is one of the most serious bacterial infections affecting the aquaculture industry today. Columnaris is transmitted horizontally from fish to fish. The disease is highly contagious and may be spread through contaminated nets, speci...

Monte Carlo random walk simulation of electron transport in confined porous TiO{sub 2} as a promising candidate for photo-electrode of nano-crystalline solar cells

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

Javadi, M.; Abdi, Y., E-mail: y.abdi@ut.ac.ir

2015-08-14

Monte Carlo continuous time random walk simulation is used to study the effects of confinement on electron transport, in porous TiO{sub 2}. In this work, we have introduced a columnar structure instead of the thick layer of porous TiO{sub 2} used as anode in conventional dye solar cells. Our simulation results show that electron diffusion coefficient in the proposed columnar structure is significantly higher than the diffusion coefficient in the conventional structure. It is shown that electron diffusion in the columnar structure depends both on the cross section area of the columns and the porosity of the structure. Also, wemore » demonstrate that such enhanced electron diffusion can be realized in the columnar photo-electrodes with a cross sectional area of ∼1 μm{sup 2} and porosity of 55%, by a simple and low cost fabrication process. Our results open up a promising approach to achieve solar cells with higher efficiencies by engineering the photo-electrode structure.« less

Monte Carlo random walk simulation of electron transport in confined porous TiO2 as a promising candidate for photo-electrode of nano-crystalline solar cells

NASA Astrophysics Data System (ADS)

Javadi, M.; Abdi, Y.

2015-08-01

Monte Carlo continuous time random walk simulation is used to study the effects of confinement on electron transport, in porous TiO2. In this work, we have introduced a columnar structure instead of the thick layer of porous TiO2 used as anode in conventional dye solar cells. Our simulation results show that electron diffusion coefficient in the proposed columnar structure is significantly higher than the diffusion coefficient in the conventional structure. It is shown that electron diffusion in the columnar structure depends both on the cross section area of the columns and the porosity of the structure. Also, we demonstrate that such enhanced electron diffusion can be realized in the columnar photo-electrodes with a cross sectional area of ˜1 μm2 and porosity of 55%, by a simple and low cost fabrication process. Our results open up a promising approach to achieve solar cells with higher efficiencies by engineering the photo-electrode structure.

Efficacy of a modified live Flavobacterium columnare vaccine in fish.

PubMed

Shoemaker, Craig A; Klesius, Phillip H; Drennan, John D; Evans, Joyce J

2011-01-01

Flavobacterium columnare is an aquatic bacterium that is responsible for columnaris disease. This aquatic pathogen has a worldwide distribution and is highly infectious to both warm and cold water fish. A modified live F. columnare vaccine was developed by repeated passage of a virulent strain on increasing concentrations of rifampicin that resulted in attenuation. Here we report vaccination/challenge trials to evaluate efficacy and safety. In separate laboratory trials, immersion vaccination of channel catfish (Ictalurus punctatus) fry between 10 to 48 days post hatch (DPH) with experimental vaccine or licensed product resulted in relative percent survival (RPS) between 57-94% following challenge. Similarly, a vaccination/challenge trial using largemouth bass (Micropterus salmoides) fry at 10 DPH was performed using various doses of licensed product under laboratory conditions. Results demonstrated safety of the vaccine and significant protection following challenge with RPS values between 74-94%, depending on vaccine dose. Together, these trials demonstrate the vaccine administered to early life-stage channel catfish and largemouth bass is safe and reduces mortality following challenge with F. columnare. Published by Elsevier Ltd.

Enhancement of ductility and improvement of abnormal Goss grain growth of magnetostrictive Fe-Ga rolled alloys

NASA Astrophysics Data System (ADS)

Li, Ji-heng; Yuan, Chao; Mu, Xing; Bao, Xiao-qian; Gao, Xue-xu

2018-04-01

The influences of initial microstructures on the mechanical properties and the recrystallization texture of magnetostrictive 0.1at% NbC-doped Fe83Ga17 alloys were investigated. The directionally solidified columnar-grained structure substantially enhanced the tensile elongation at intermediate temperatures by suppressing fracture along the transverse boundaries. Compared with tensile elongations of 1.0% at 300°C and 12.0% at 500°C of the hot-forged equiaxed-grained alloys, the columnar-grained alloys exhibited substantially increased tensile elongations of 21.6% at 300°C and 46.6% at 500°C. In the slabs for rolling, the introduction of <001>-oriented columnar grains also promotes the secondary recrystallization of Goss grains in the finally annealed sheets, resulting in an improvement of the saturation magnetostriction. For the columnar-grained specimens, the inhomogeneous microstructure and disadvantage in number and size of Goss grains are improved in the primarily annealed sheets, which is beneficial to the abnormal growth of Goss grains during the final annealing process.

Studies of the Influence of Beam Profile and Cooling Conditions on the Laser Deposition of a Directionally-Solidified Superalloy.

PubMed

Yang, Shuo; Du, Dong; Chang, Baohua

2018-02-04

In the laser deposition of single crystal and directionally-solidified superalloys, it is desired to form laser deposits with high volume fractions of columnar grains by suppressing the columnar-to-equiaxed transition efficiently. In this paper, the influence of beam profile (circular and square shapes) and cooling conditions (natural cooling and forced cooling) on the geometric morphology and microstructure of deposits were experimentally studied in the laser deposition of a directionally-solidified superalloy, IC10, and the mechanisms of influence were revealed through a numerical simulation of the thermal processes during laser deposition. The results show that wider and thinner deposits were obtained with the square laser beam than those with the circular laser beam, regardless of whether natural or forced cooling conditions was used. The heights and contact angles of deposits were notably increased due to the reduced substrate temperatures by the application of forced cooling for both laser beam profiles. Under natural cooling conditions, columnar grains formed epitaxially at both the center and the edges of the deposits with the square laser beam, but only at the center of the deposits with the circular laser beam; under forced cooling conditions, columnar grains formed at both the center and the edges of deposits regardless of the laser beam profile. The high ratios of thermal gradient and solidification velocity in the height direction of the deposits were favorable to forming deposits with higher volume fractions of columnar grains.

New hosts and genetic diversity of Flavobacterium columnare isolated from Brazilian native species and Nile tilapia.

PubMed

Barony, G M; Tavares, G C; Assis, G B N; Luz, R K; Figueiredo, H C P; Leal, C A G

2015-11-17

Flavobacterium columnare is responsible for disease outbreaks in freshwater fish farms. Several Brazilian native fish have been commercially exploited or studied for aquaculture purposes, including Amazon catfish Leiarius marmoratus × Pseudoplatystoma fasciatum and pacamã Lophiosilurus alexandri. This study aimed to identify the aetiology of disease outbreaks in Amazon catfish and pacamã hatcheries and to address the genetic diversity of F. columnare isolates obtained from diseased fish. Two outbreaks in Amazon catfish and pacamã hatcheries took place in 2010 and 2011. Four F. columnare strains were isolated from these fish and identified by PCR. The disease was successfully reproduced under experimental conditions for both fish species, fulfilling Koch's postulates. The genomovar of these 4 isolates and of an additional 11 isolates from Nile tilapia Oreochromis niloticus was determined by 16S rRNA restriction fragment length polymorphism PCR. The genetic diversity was evaluated by phylogenetic analysis of the 16S rRNA gene and repetitive extragenic palindromic PCR (REP-PCR). Most isolates (n = 13) belonged to genomovar II; the remaining 2 isolates (both from Nile tilapia) were assigned to genomovar I. Phylogenetic analysis and REP-PCR were able to demonstrate intragenomovar diversity. This is the first report of columnaris in Brazilian native Amazon catfish and pacamã. The Brazilian F. columnare isolates showed moderate diversity, and REP-PCR was demonstrated to be a feasible method to evaluate genetic variability in this bacterium.

Studies of the Influence of Beam Profile and Cooling Conditions on the Laser Deposition of a Directionally-Solidified Superalloy

PubMed Central

Yang, Shuo; Du, Dong

2018-01-01

In the laser deposition of single crystal and directionally-solidified superalloys, it is desired to form laser deposits with high volume fractions of columnar grains by suppressing the columnar-to-equiaxed transition efficiently. In this paper, the influence of beam profile (circular and square shapes) and cooling conditions (natural cooling and forced cooling) on the geometric morphology and microstructure of deposits were experimentally studied in the laser deposition of a directionally-solidified superalloy, IC10, and the mechanisms of influence were revealed through a numerical simulation of the thermal processes during laser deposition. The results show that wider and thinner deposits were obtained with the square laser beam than those with the circular laser beam, regardless of whether natural or forced cooling conditions was used. The heights and contact angles of deposits were notably increased due to the reduced substrate temperatures by the application of forced cooling for both laser beam profiles. Under natural cooling conditions, columnar grains formed epitaxially at both the center and the edges of the deposits with the square laser beam, but only at the center of the deposits with the circular laser beam; under forced cooling conditions, columnar grains formed at both the center and the edges of deposits regardless of the laser beam profile. The high ratios of thermal gradient and solidification velocity in the height direction of the deposits were favorable to forming deposits with higher volume fractions of columnar grains. PMID:29401715

Prediction of the As-Cast Structure of Al-4.0 Wt Pct Cu Ingots

NASA Astrophysics Data System (ADS)

Ahmadein, Mahmoud; Wu, M.; Li, J. H.; Schumacher, P.; Ludwig, A.

2013-06-01

A two-stage simulation strategy is proposed to predict the as-cast structure. During the first stage, a 3-phase model is used to simulate the mold-filling process by considering the nucleation, the initial growth of globular equiaxed crystals and the transport of the crystals. The three considered phases are the melt, air and globular equiaxed crystals. In the second stage, a 5-phase mixed columnar-equiaxed solidification model is used to simulate the formation of the as-cast structure including the distinct columnar and equiaxed zones, columnar-to-equiaxed transition, grain size distribution, macrosegregation, etc. The five considered phases are the extradendritic melt, the solid dendrite, the interdendritic melt inside the equiaxed grains, the solid dendrite, and the interdendritic melt inside the columnar grains. The extra- and interdendritic melts are treated as separate phases. In order to validate the above strategy, laboratory ingots (Al-4.0 wt pct Cu) are poured and analyzed, and a good agreement with the numerical predictions is achieved. The origin of the equiaxed crystals by the "big-bang" theory is verified to play a key role in the formation of the as-cast structure, especially for the castings poured at a low pouring temperature. A single-stage approach that only uses the 5-phase mixed columnar-equiaxed solidification model and ignores the mold filling can predict satisfactory results for a casting poured at high temperature, but it delivers false results for the casting poured at low temperature.

Effect of Suspension Plasma-Sprayed YSZ Columnar Microstructure and Bond Coat Surface Preparation on Thermal Barrier Coating Properties

NASA Astrophysics Data System (ADS)

Bernard, Benjamin; Quet, Aurélie; Bianchi, Luc; Schick, Vincent; Joulia, Aurélien; Malié, André; Rémy, Benjamin

2017-08-01

Suspension plasma spraying (SPS) is identified as promising for the enhancement of thermal barrier coating (TBC) systems used in gas turbines. Particularly, the emerging columnar microstructure enabled by the SPS process is likely to bring about an interesting TBC lifetime. At the same time, the SPS process opens the way to a decrease in thermal conductivity, one of the main issues for the next generation of gas turbines, compared to the state-of-the-art deposition technique, so-called electron beam physical vapor deposition (EB-PVD). In this paper, yttria-stabilized zirconia (YSZ) coatings presenting columnar structures, performed using both SPS and EB-PVD processes, were studied. Depending on the columnar microstructure readily adaptable in the SPS process, low thermal conductivities can be obtained. At 1100 °C, a decrease from 1.3 W m-1 K-1 for EB-PVD YSZ coatings to about 0.7 W m-1 K-1 for SPS coatings was shown. The higher content of porosity in the case of SPS coatings increases the thermal resistance through the thickness and decreases thermal conductivity. The lifetime of SPS YSZ coatings was studied by isothermal cyclic tests, showing equivalent or even higher performances compared to EB-PVD ones. Tests were performed using classical bond coats used for EB-PVD TBC coatings. Thermal cyclic fatigue performance of the best SPS coating reached 1000 cycles to failure on AM1 substrates with a β-(Ni,Pt)Al bond coat. Tests were also performed on AM1 substrates with a Pt-diffused γ-Ni/γ'-Ni3Al bond coat for which more than 2000 cycles to failure were observed for columnar SPS YSZ coatings. The high thermal compliance offered by both the columnar structure and the porosity allowed the reaching of a high lifetime, promising for a TBC application.

Volumetric and x-ray investigations of the crystalline and columnar phases of copper (II) soaps under pressure

NASA Astrophysics Data System (ADS)

Ibn-Elhaj, M.; Guillon, D.; Skoulios, A.

1992-12-01

Binuclear copper (II) carboxylates, Cu2(CnH2n+1O2)4, crystallize at room temperature in layered systems in which planes of polar cores are separated by a double layer of alkyl chains. These compounds are mesomorphic in nature above ca. 100 °C. Pseudopolymeric chains of regularly stacked binuclear cores are located at the nodes of a two-dimensional hexagonal lattice and are surrounded by disordered aliphatic chains. The transition from the crystal to the columnar mesophase is characterized by a change in the repeat distance of the binuclear cores along the pseudopolymeric axis. In the crystalline phase, these cores are all oriented in the same direction with a repeat distance of 5.2 Å in the columnar mesophase, the polar cores are perpendicular to the columnar axis and superposed in a fourfold helicoidal fashion, at least on a local scale, with a repeat distance of 4.7 Å. We present here the effect of pressure on these anisotropic systems in a direction parallel to the columnar axis, and in the plane of the two-dimensional lattice. In a first part, we report the pressure-volume-temperature (P-V-T) relationship of these compounds (n=12, 18, and 24) in the temperature range from 30 to 200 °C, and in the pressure range from 1 to 2000 bars. Isothermal compressibility and isobaric expansion are determined in the crystalline and mesomorphic phases. In the mesophase, pressure-volume isotherms can be described by the Tait equation, as in most liquids or molten polymers. In a second part, we discuss the x-ray-diffraction experiments performed under pressure. In the mesophase, the area of the two-dimensional lattice decreases with increasing pressure and, at sufficiently high pressure, the columnar mesophase transforms into a crystalline lamellar phase. By combining P-V-T and x-ray results, we deduce an increase of the stacking period of the binuclear cores as a function of increasing pressure.

Yeast cell surface display for lipase whole cell catalyst and its applications

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

Liu, Yun; Zhang, Rui; Lian, Zhongshuai

The cell surface display technique allows for the expression of target proteins or peptides on the microbial cell surface by fusing an appropriate protein as an anchoring motif. Yeast display systems, such as Pichia pastoris, Yarowia lipolytica and Saccharomyces cerevisiae, are ideal, alternative and extensive display systems with the advantage of simple genetic manipulation and post-translational modification of expressed heterologous proteins. Engineered yeasts show high performance characteristics and variant utilizations. Herein, we comprehensively summarize the variant factors affecting lipase whole cell catalyst activity and display efficiency, including the structure and size of target proteins, screening anchor proteins, type and chainmore » length of linkers, and the appropriate matching rules among the above-mentioned display units. Furthermore, we also address novel approaches to enhance stability and activity of recombinant lipases, such as VHb gene co-expression, multi-enzyme co-display technique, and the micro-environmental interference and self-assembly techniques. Finally, we represent the variety of applications of whole cell surface displayed lipases on yeast cells in non-aqueous phases, including synthesis of esters, PUFA enrichment, resolution of chiral drugs, organic synthesis and biofuels. We demonstrate that the lipase surface display technique is a powerful tool for functionalizing yeasts to serve as whole cell catalysts, and increasing interest is providing an impetus for broad application of this technique.« less

Discovery of synthesis and secretion of polyol esters of fatty acids by four basidiomycetous yeast species in the order Sporidiobolales.

PubMed

Garay, Luis A; Sitepu, Irnayuli R; Cajka, Tomas; Fiehn, Oliver; Cathcart, Erin; Fry, Russell W; Kanti, Atit; Joko Nugroho, Agustinus; Faulina, Sarah Asih; Stephanandra, Sira; German, J Bruce; Boundy-Mills, Kyria L

2017-06-01

Polyol esters of fatty acids (PEFA) are amphiphilic glycolipids produced by yeast that could play a role as natural, environmentally friendly biosurfactants. We recently reported discovery of a new PEFA-secreting yeast species, Rhodotorula babjevae, a basidiomycetous yeast to display this behavior, in addition to a few other Rhodotorula yeasts reported on the 1960s. Additional yeast species within the taxonomic order Sporidiobolales were screened for secreted glycolipid production. PEFA production equal or above 1 g L -1 were detected in 19 out of 65 strains of yeast screened, belonging to 6 out of 30 yeast species tested. Four of these species were not previously known to secrete glycolipids. These results significantly increase the number of yeast species known to secrete PEFA, holding promise for expanding knowledge of PEFA synthesis and secretion mechanisms, as well as setting the groundwork towards commercialization.

Bioactive Steroids with Methyl Ester Group in the Side Chain from a Reef Soft Coral Sinularia brassica Cultured in a Tank.

PubMed

Huang, Chiung-Yao; Su, Jui-Hsin; Liaw, Chih-Chuang; Sung, Ping-Jyun; Chiang, Pei-Lun; Hwang, Tsong-Long; Dai, Chang-Feng; Sheu, Jyh-Horng

2017-09-01

A c ontinuing chemical investigation of the ethyl acetate (EtOAc) extract of a reef soft coral Sinularia brassica , which was cultured in a tank, afforded four new steroids with methyl ester groups, sinubrasones A-D (1-4) for the first time. In particular, 1 possesses a β-D-xylopyranose. The structures of the new compounds were elucidated on the basis of spectroscopic analyses. The cytotoxicities of compounds 1-4 against the proliferation of a limited panel of cancer cell lines were assayed. The anti-inflammatory activities of these new compounds 1-4 were also evaluated by measuring their ability to suppress superoxide anion generation and elastase release in N -formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced human neutrophils. Compounds 2 and 3 were shown to exhibit significant cytotoxicity, and compounds 3 and 4 were also found to display attracting anti-inflammatory activities.

Influence of columnar defects on the thermodynamic properties of BSCCO

NASA Astrophysics Data System (ADS)

van der Beek, C. J.; Indenbom, M. V.; Berseth, V.; Konczykowski, M.; Li, T. W.; Kes, P. H.; Benoit, W.

1996-03-01

Amorphous columnar defects strongly affect the reversible magnetization of Bi2Sr2CaCu2O8+δ single crystals both in the vortex solid, where the change reflects the change in vortex energy due to pinning, and in the vortex liquid, where the randomly positioned columns disrupt the interaction between superconducting fluctuations.

Spleen size and plasma levels of mannose binding lectin in channel catfish Ictalurus punctatus families exhibiting different susceptibilities to Flavobacterium columnare and Edwardsiella ictaluri

USDA-ARS?s Scientific Manuscript database

Two major problems in the channel catfish (Ictalurus punctatus) aquaculture industry have been high disease losses to enteric septicemia of catfish (ESC), caused by the bacterium Edwardsiella ictaluri and columnaris disease, caused by the bacterium Flavobacterium columnare. Methods to control these...

Missing the target: DNAk is a dominant epitope in the humoral immune response of channel catfish (Ictalurus punctatus) to Flavobacterium columnare

USDA-ARS?s Scientific Manuscript database

Vaccination remains a viable alternative for bacterial disease protection in fish; however additional work is required to understand the mechanisms of adaptive immunity in the channel catfish. To assess the humoral immune response to Flavobacterium columnare; a group of channel catfish were first im...

Draft genome sequence of the fish pathogen Flavobacterium columnare strain CSF-298-10

USDA-ARS?s Scientific Manuscript database

We announce the genome assembly of Flavobacterium columnare strain CSF-298-10, a strain isolated from an outbreak of Columnaris disease at a commercial trout farm in Snake River Valley Idaho, USA. The complete genome consists of 13 contigs totaling 3,284,579 bp, average G+C content of 31.5% and 2933...

Mucinous cystadenocarcinoma of the breast.

PubMed

Koenig, C; Tavassoli, F A

1998-06-01

Four unusual cases of primary mammary mucinous cystadenocarcinoma composed predominantly of tall columnar cells with abundant intracytoplasmic mucin are reported; they were multicystic and appeared virtually identical to mucinous cystadenocarcinomas of the ovary and pancreas. Three of the women were white and one was black, they ranged in age from 49 to 67 years (average 58), and they had tumors that ranged from 0.8 to 19 cm in diameter. Microscopically, the tumors were characterized by cystic spaces lined by predominantly bland-appearing columnar mucinous cells with stratification, tufting, and papillary formations. Varying degrees of cytologic atypia were focally evident, with gradual loss of the intracytoplasmic mucin and transformation to an eosinophilic squamoid cell population. Multifocal invasion generally emanated from these eosinophilic, squamoid areas in all cases. All four tumors displayed immunoreactivity for MIB-1 (Ki-67) in a relatively high percentage of cells and failed to show immunoreactivity for estrogen receptors and progesterone receptors. All four stained positively with cytokeratin 7 (CK7) but were negative with cytokeratin 20 (CK20). Mastectomy and axillary lymph node dissection were performed in three cases and lumpectomy with lymph node dissection in the remaining case. Lymph node metastases, identified in only one patient, retained the distinctive morphology. Three of the patients are alive without evidence of disease 11, 22, and 24 months after the diagnosis; the fourth is a recent case. These tumors are a rare, clinicopathologically distinct type of primary breast carcinoma that should be distinguished from typical mucinous (colloid) carcinomas of the breast and, more importantly, metastases from other sites.

Sunphotometric Measurement of Columnar H2O and Aerosol Optical Depth During the 3rd Water Vapor IOP in Fall 2000 at the SGP ARM Site

NASA Technical Reports Server (NTRS)

Schmid, B; Eilers, J. A.; McIntosh, D. M.; Longo, K.; Livingston, J. M.; Redemann, J.; Russell, P. B.; Braun, J.; Rocken, C.; Hipskind, R. Stephen (Technical Monitor)

2001-01-01

We conducted ground-based measurements with the Ames Airborne Tracking 6-channel Sunphotometer (AATS-6) during the 3rd Water Vapor IOP (WVIOP3), September 18 - October 8, 2000 at the SGP ARM site. For this deployment our primary result was columnar water vapor (CWV) obtained from continuous solar transmittance measurements in the 0.94-micron band. In addition, we simultaneously measured aerosol optical depth (AOD) at 380, 450, 525, 864 and 1020 nm. During the IOP, preliminary results of CWV and AOD were displayed in real-time. The result files were made available to other investigators by noon of the next day. During WVIOP3 those data were shown on the daily intercomparison plots on the IOP web-site. Our preliminary results for CWV fell within the spread of values obtained from other techniques. After conclusion of WVIOP3, AATS-6 was shipped directly to Mauna Loa, Hawaii for post-mission calibration. The updated calibration, a cloud screening technique for AOD, along with other mostly cosmetic changes were applied to the WVIOP3 data set and released as version 0.1. The resulting changes in CWV are small, the changes in AOD and Angstrom parameter are more noticeable. Data version 0.1 was successfully submitted to the ARM External Data Center. In the poster we will show data examples for both CWV and AOD. We will also compare our CWV results with those obtained from a GPS (Global Positioning System) slant path method.

Kinetic studies and predictions on the hydrolysis and aminolysis of esters of 2-S-phosphorylacetates.

PubMed

Trmčić, Milena; Hodgson, David R W

2010-08-16

Heterobifunctional cross-linking agents are useful in both protein science and organic synthesis. Aminolysis of reactive esters in aqueous systems is often used in bioconjugation chemistry, but it must compete against hydrolysis processes. Here we study the kinetics of aminolysis and hydrolysis of 2-S-phosphorylacetate ester intermediates that result from displacement of bromide by a thiophosphate nucleophile from commonly used bromoacetate ester cross-linking agents. We found cross-linking between uridine-5'-monophosphorothioate and D-glucosamine using N-hydroxybenzotriazole and N-hydroxysuccinimde bromoacetates to be ineffective. In order to gain insight into these shortfalls, 2-S-(5'-thiophosphoryluridine)acetic acid esters were prepared using p-nitrophenyl bromoacetate or m-nitrophenyl bromoacetate in combination with uridine-5'-monophosphorothioate. Kinetics of hydrolysis and aminolysis of the resulting p- and m-nitrophenyl 2-S-(5'-thiophosphoryluridine)acetates were determined by monitoring the formation of phenolate ions spectrophotometrically as a function of pH. The p- and m-nitrophenyl 2-S-(5'-thiophosphoryluridine)acetates showed similar reactivity profiles despite the significant difference in the pK(aH) values of their nitrophenolate leaving groups. Both were more reactive with respect to hydrolysis and aminolysis in comparison to their simple acetate progenitors, but their calculated selectivity towards aminolysis vs hydrolysis, while reasonable, would not lead to clean reactions that do not require purification. Extrapolations of the kinetic data were used to predict leaving group pK(a) values that could lead to improved selectivity towards aminolysis while retaining reasonable reaction times. Both p- and m-nitrophenyl 2-S-(5'-thiophosphoryluridine)acetates show some selectivity towards aminolysis over hydrolysis, with the m-nitrophenolate system displaying slightly better selectivity. Extrapolation of the data for hydrolysis and aminolysis of these esters suggests that the use of readily accessible trifluoroethyl 2-S-(5'-thiophosphoryluridine)acetate with a leaving group pK(aH) of 12.4 should afford better selectivity while maintaining reasonable reaction times. Kinetically, p- and m-nitrophenyl 2-S-(5'-thiophosphoryluridine)acetates show similar properties to o-nitrophenyl 2-S-ethylacetate, and show no evidence for intramolecular catalysis of hydrolysis or aminolysis by the phosphoryl groups.

Abiotic tooth enamel

NASA Astrophysics Data System (ADS)

Yeom, Bongjun; Sain, Trisha; Lacevic, Naida; Bukharina, Daria; Cha, Sang-Ho; Waas, Anthony M.; Arruda, Ellen M.; Kotov, Nicholas A.

2017-03-01

Tooth enamel comprises parallel microscale and nanoscale ceramic columns or prisms interlaced with a soft protein matrix. This structural motif is unusually consistent across all species from all geological eras. Such invariability—especially when juxtaposed with the diversity of other tissues—suggests the existence of a functional basis. Here we performed ex vivo replication of enamel-inspired columnar nanocomposites by sequential growth of zinc oxide nanowire carpets followed by layer-by-layer deposition of a polymeric matrix around these. We show that the mechanical properties of these nanocomposites, including hardness, are comparable to those of enamel despite the nanocomposites having a smaller hard-phase content. Our abiotic enamels have viscoelastic figures of merit (VFOM) and weight-adjusted VFOM that are similar to, or higher than, those of natural tooth enamels—we achieve values that exceed the traditional materials limits of 0.6 and 0.8, respectively. VFOM values describe resistance to vibrational damage, and our columnar composites demonstrate that light-weight materials of unusually high resistance to structural damage from shocks, environmental vibrations and oscillatory stress can be made using biomimetic design. The previously inaccessible combinations of high stiffness, damping and light weight that we achieve in these layer-by-layer composites are attributed to efficient energy dissipation in the interfacial portion of the organic phase. The in vivo contribution of this interfacial portion to macroscale deformations along the tooth’s normal is maximized when the architecture is columnar, suggesting an evolutionary advantage of the columnar motif in the enamel of living species. We expect our findings to apply to all columnar composites and to lead to the development of high-performance load-bearing materials.

Simulation and observation of line-slip structures in columnar structures of soft spheres

NASA Astrophysics Data System (ADS)

Winkelmann, J.; Haffner, B.; Weaire, D.; Mughal, A.; Hutzler, S.

2017-07-01

We present the computed phase diagram of columnar structures of soft spheres under pressure, of which the main feature is the appearance and disappearance of line slips, the shearing of adjacent spirals, as pressure is increased. A comparable experimental observation is made on a column of bubbles under forced drainage, clearly exhibiting the expected line slip.

Simulation and observation of line-slip structures in columnar structures of soft spheres.

PubMed

Winkelmann, J; Haffner, B; Weaire, D; Mughal, A; Hutzler, S

2017-07-01

We present the computed phase diagram of columnar structures of soft spheres under pressure, of which the main feature is the appearance and disappearance of line slips, the shearing of adjacent spirals, as pressure is increased. A comparable experimental observation is made on a column of bubbles under forced drainage, clearly exhibiting the expected line slip.

Draft Genome Sequence of the Fish Pathogen Flavobacterium columnare Genomovar III Strain PH-97028 (=CIP 109753).

PubMed

Criscuolo, Alexis; Chesneau, Olivier; Clermont, Dominique; Bizet, Chantal

2018-04-05

Flavobacterium columnare strain PH-97028 (=CIP 109753) is a genomovar III reference strain that was isolated from a diseased Ayu fish in Japan. We report here the analysis of the first available genomovar III sequence of this species to aid in identification, epidemiological tracking, and virulence studies. Copyright © 2018 Criscuolo et al.

Assessment of Aquaflor (c), copper sulfate and potassium permanganate for control of Aeromonas hydrophila and Flavobacterium columnare infection in sunshine bass, Morone chrysops female x Morone saxatilis male

USDA-ARS?s Scientific Manuscript database

Two experiments were conducted to assess different therapeutants against a mixed infection of Aeromonas hydrophila and Flavobacterium columnare in sunshine bass (SB) (Morone chrysops female x Morone saxatilis male). Experiment 1 assessed the efficacy of copper sulfate (CuSO4), florfenicol-medicated...

Effect of Starting As-cast Structure on the Microstructure-Texture Evolution During Subsequent Processing and Finally Ridging Behavior of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Modak, Pranabananda; Patra, Sudipta; Mitra, Rahul; Chakrabarti, Debalay

2018-03-01

Effect of the initial as-cast structure on the microstructure-texture evolution during thermomechanical processing of 409L grade ferritic stainless steel was studied. Samples from the regions of cast slab having `columnar,' `equiaxed,' and a mixture of `columnar' and `equiaxed' grains were subjected to two different processing schedules: one with intermediate hot-band annealing before cold-rolling followed by final annealing, and another without any hot-band annealing. EBSD study reveals that large columnar crystals with cube orientation are very difficult to deform and recrystallize uniformly. Resultant variations in ferrite grain structure and retention of cube-textured band in cold-rolled and annealed sheet contribute to ridging behavior during stretch forming. Initial equiaxed grain structure is certainly beneficial to reduce or even eliminate ridging defect by producing uniform ferrite grain structure, free from any texture banding. Application of hot-band annealing treatment is also advantageous as it can maximize the evolution of beneficial gamma-fiber texture and eliminate the ridging defect in case of completely `equiaxed' starting structure. Such treatment reduces the severity of ridging even if the initial structure contains typically mixed `columnar-equiaxed' grains.

Effect of Starting As-cast Structure on the Microstructure-Texture Evolution During Subsequent Processing and Finally Ridging Behavior of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Modak, Pranabananda; Patra, Sudipta; Mitra, Rahul; Chakrabarti, Debalay

2018-06-01

Effect of the initial as-cast structure on the microstructure-texture evolution during thermomechanical processing of 409L grade ferritic stainless steel was studied. Samples from the regions of cast slab having `columnar,' `equiaxed,' and a mixture of `columnar' and `equiaxed' grains were subjected to two different processing schedules: one with intermediate hot-band annealing before cold-rolling followed by final annealing, and another without any hot-band annealing. EBSD study reveals that large columnar crystals with cube orientation are very difficult to deform and recrystallize uniformly. Resultant variations in ferrite grain structure and retention of cube-textured band in cold-rolled and annealed sheet contribute to ridging behavior during stretch forming. Initial equiaxed grain structure is certainly beneficial to reduce or even eliminate ridging defect by producing uniform ferrite grain structure, free from any texture banding. Application of hot-band annealing treatment is also advantageous as it can maximize the evolution of beneficial gamma-fiber texture and eliminate the ridging defect in case of completely `equiaxed' starting structure. Such treatment reduces the severity of ridging even if the initial structure contains typically mixed `columnar-equiaxed' grains.

Columnar alterations of NADH fluorescence during hypoxia-ischemia in immature rat brain.

PubMed

Welsh, F A; Vannucci, R C; Brierley, J B

1982-01-01

Cerebral hypoxia-ischemia was produced in 7-day postnatal rats by unilateral carotid artery ligation combined with systemic hypoxia (8% O2). Levels of high energy phosphates, which were only slightly altered in the contralateral hemisphere, were nearly depleted in the ipsilateral hemisphere during the 3-h hypoxic insult. With hypoxia of between 1 and 3 hours' duration, columnar alterations of cortical NADH fluorescence occurred in the same location and regional pattern as did histologic damage demonstrated previously (Rice et al., 1981). In regions exhibiting columns of NADH fluorescence, there was no evidence of a columnar reduction of high energy phosphates as levels of ATP and phosphocreatine were nearly zero. Recovery from 3 h of hypoxia was accompanied by partial and regionally heterogeneous restoration of ATP within the ipsilateral hemisphere. Columnar variations of NADH fluorescence were not detected in the recovery period; rather, regions with impaired restitution of high energy phosphates exhibited NADH fluorescence that was diminished diffusely compared to the contralateral hemisphere. The correlation between depressed NADH fluorescence and depleted ATP, present as cortical columns during hypoxia and as larger regions during recovery, suggests that decreased formation of NADH may be limiting the resynthesis of high energy phosphates.

Phase behavior and transitions of self-assembling nano-structured materials

NASA Astrophysics Data System (ADS)

Duan, Hu

Homologous series of supramolecular nanostructures have been investigated by a combination of transmission electron microscopy (TEM), electron diffraction (ED), thermal polarized optical microscopy and X-ray diffraction (XRD). Materials include amphiphilic oligomers and polymer such as charged complexes, dipeptide dendrons semi-fluorinated dendron and polyethyleneimines. Upon microphase separation, they self-assemble into either cylindrical or spherical shapes, which co-organize into a 2D P6mm hexagonal columnar phase or 3D Pm 3¯ n and Im 3¯ m cubic phases. Correlation between the phase selection and molecular architecture is established accordingly. The order-disorder transition (ODT) is explored by rheometry and rheo-optical microscopy in a model polymeric compound poly(N-[3,4-bis(n-dodecan-1-yloxy)benzoyl]ethyleneimine). Shear alignment of the hexagonal columnar liquid crystalline phase along the velocity direction at low temperature and shear disordering in the vicinity of the ODT were observed. After cessation of shear, transformation back to the stable columnar phase follows a row-nucleation mechanism. The order-order transition process is explored in a monodendron that exhibits a hexagonal columnar and a weakly birefringent mesophase. Polarized DIC microscopy strongly supports an epitaxial relationship between them.

Acid-degradable lactobionic acid-modified soy protein nanogels crosslinked by ortho ester linkage for efficient antitumor in vivo.

PubMed

Cheng, Xu; Qin, Jiejie; Wang, Xin; Zha, Qian; Yao, Weijing; Fu, Shengxiang; Tang, Rupei

2018-05-03

It remains a crucial challenge to achieve efficient cellular uptake and intracellular drug release in tumor cells for the nanoscale drug delivery systems. Herein, acid-degradable nanogels were prepared by cross-linking methacrylated soy protein with an acid-labile ortho ester cross-linker (NG1), and then modified with lactobionic acid (LA) to give tumor-targeted nanogels (NG2). Both NG1 and NG2 displayed excellent stability in neutral environment, while showed pH-triggered degradation behaviors under mildly acidic conditions resulting from the breakage of ortho ester bonds. Doxorubicin (DOX) was successfully loaded into nanogels, which exhibited an accelerated release at low pH. In vitro cell studies demonstrated that LA-modified nanogels could effectively improve cellular internalization, show higher cytotoxicity and apoptosis toward asialoglycoprotein receptor (ASGPR) over-expressed HepG2 cells. In vivo antitumor experimentproved that LA modification could significantly enhance the tumor-targeting ability of nanogels and increase DOX concentration in tumor site, leading to better therapeutic efficacy. Histological analysis further demonstrated that soy protein-based nanogels did not cause any damage to normal organs. Overall, these pH-sensitive and tumor-targeting soy protein-based nanogels can be potential drug carriers for efficient tumor treatment. Copyright © 2018. Published by Elsevier B.V.

Glycophenotype evaluation in cutaneous tumors using lectins labeled with acridinium ester.

PubMed

Lima, Luiza Rayanna Amorim; Bezerra, Matheus Filgueira; Almeida, Sinara Mônica Vitalino; Silva, Lúcia Patrícia Bezerra Gomes; Beltrão, Eduardo Isidoro Carneiro; Carvalho Júnior, Luiz Bezerra

2013-01-01

Tumor cells show alterations in their glycosylation patterns when compared to normal cells. Lectins can be used to evaluate these glycocode changes. Chemiluminescence assay is an effective technique for quantitative analysis of proteins, nucleic acids, and carbohydrates due to its high sensitivity, specificity, and rapid testing. To use histochemiluminescence based on lectin conjugated to acridinium ester (AE) for the investigation of glycophenotype changes in cutaneous tumors. Concanavalin A (Con A), Peanut agglutinin (PNA), Ulex europaeus agglutinin-I (UEA-I), and Maackia amurensis agglutinin (MAA) were conjugated to acridinium ester. Biopsies of cutaneous tumors and normal skin were incubated with the lectins-AE, and chemiluminescence was quantified and expressed as Relative Light Units (RLU). Results. Actinic keratosis (AK), keratoacanthoma (KA), squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) showed lower expression of α -D-glucose/mannose and α -L-fucose residues compared to normal tissue. Cutaneous tumors displayed higher expression of Gal- β (1-3)-GalNAc residues than normal tissue. AK and SCC exhibited higher expression of Neu5Ac- α (2,3)Gal residues than normal epidermis. KA and BCC showed equivalent RLU values compared to normal tissue. Lectin histochemiluminescence allowed quantitative assessment of the carbohydrate expression in cutaneous tissues, contributing to eliminate the subjectivity of conventional techniques used in the histopathological diagnosis.

Modulating lipophilicity of rohitukine via prodrug approach: Preparation, characterization, and in vitro enzymatic hydrolysis in biorelevant media.

PubMed

Kumar, Vikas; Bharate, Sonali S; Vishwakarma, Ram A

2016-09-20

Rohitukine is a medicinally important natural product which has inspired the discovery of two anticancer clinical candidates. Rohitukine is highly hydrophilic in nature which hampers its oral bioavailability. Thus, herein our objective was to improve the drug-like properties of rohitukine via prodrug-strategy. Various ester prodrugs were synthesized and studied for solubility, lipophilicity, chemical stability and enzymatic hydrolysis in plasma/esterase. All prodrugs displayed lower aqueous solubility and improved lipophilicity compared with rohitukine, which was in accordance with the criteria of compounds in drug-discovery. The stability of synthesized prodrugs was evaluated in buffers at different pH, SGF, SIF, rat plasma and in esterase enzyme. The rate of hydrolysis in all incubation media was dependent primarily on the acyl promoieties. Hexanoyl ester prodrug of rohitukine, 3d, was stable under chemical conditions; however it was completely hydrolyzed to rohitukine, in plasma and in esterase in 4h. Hexanoate ester 3d appeared to be the most promising prodrug as it remained intact at gastric/intestinal pH and was completely transformed to the parent compound in plasma as desired for an ideal prodrug. The data presented herein, will help in designing prodrugs with desired physicochemical properties in future in structurally similar chemotypes. Copyright © 2016 Elsevier B.V. All rights reserved.

Injectable hyperbranched poly(β-amino ester) hydrogels with on-demand degradation profiles to match wound healing processes† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc03913a

PubMed Central

Xu, Qian; Guo, Linru; A, Sigen; Gao, Yongsheng; Zhou, Dezhong; Greiser, Udo; Creagh-Flynn, Jack; Zhang, Hong; Dong, Yixiao; Cutlar, Lara; Wang, Fagang; Liu, Wenguang

2018-01-01

Adjusting biomaterial degradation profiles to match tissue regeneration is a challenging issue. Herein, biodegradable hyperbranched poly(β-amino ester)s (HP-PBAEs) were designed and synthesized via “A2 + B4” Michael addition polymerization, and displayed fast gelation with thiolated hyaluronic acid (HA-SH) via a “click” thiol–ene reaction. HP-PBAE/HA-SH hydrogels showed tunable degradation profiles both in vitro and in vivo using diamines with different alkyl chain lengths and poly(ethylene glycol) diacrylates with varied PEG spacers. The hydrogels with optimized degradation profiles encapsulating ADSCs were used as injectable hydrogels to treat two different types of humanized excisional wounds – acute wounds with faster healing rates and diabetic wounds with slower healing and neo-tissue formation. The fast-degrading hydrogel showed accelerated wound closure in acute wounds, while the slow-degrading hydrogel showed better wound healing for diabetic wounds. The results demonstrate that the new HP-PBAE-based hydrogel in combination with ADSCs can be used as a well-controlled biodegradable skin substitute, which demonstrates a promising approach in the treatment of various types of skin wounds. PMID:29719691

Columnar mesophases of hexabenzocoronene derivatives. II. Charge carrier mobility

NASA Astrophysics Data System (ADS)

Kirkpatrick, James; Marcon, Valentina; Kremer, Kurt; Nelson, Jenny; Andrienko, Denis

2008-09-01

Combining atomistic molecular dynamic simulations, Marcus-Hush theory description of charge transport rates, and master equation description of charge dynamics, we correlate the temperature-driven change of the mesophase structure with the change of charge carrier mobilities in columnar phases of hexabenzocoronene derivatives. The time dependence of fluctuations in transfer integrals shows that static disorder is predominant in determining charge transport characteristics. Both site energies and transfer integrals are distributed because of disorder in the molecular arrangement. It is shown that the contributions to the site energies from polarization and electrostatic effects are of opposite sign for positive charges. We look at three mesophases of hexabenzocoronene: herringbone, discotic, and columnar disordered. All results are compared to time resolved microwave conductivity data and show excellent agreement with no fitting parameters.

Discotic columnar liquid crystal studied in the bulk and nanoconfined states by molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Busselez, Rémi; Cerclier, Carole V.; Ndao, Makha; Ghoufi, Aziz; Lefort, Ronan; Morineau, Denis

2014-10-01

A prototypical Gay Berne discotic liquid crystal was studied by means of molecular dynamics simulations both in the bulk state and under confinement in a nanoporous channel. The phase behavior of the confined system strongly differs from its bulk counterpart: the bulk isotropic-to-columnar transition is replaced by a continuous ordering from a paranematic to a columnar phase. Moreover, a new transition is observed at a lower temperature in the confined state, which corresponds to a reorganization of the intercolumnar order. It reflects the competing effects of pore surface interaction and genuine hexagonal packing of the columns. The translational molecular dynamics in the different phases has been thoroughly studied and discussed in terms of collective relaxation modes, non-Gaussian behavior, and hopping processes.

The structures of the crystalline phase and columnar mesophase of rhodium (II) heptanoate and of its binary mixture with copper (II) heptanoate probed by EXAFS

NASA Astrophysics Data System (ADS)

Inb-Elhaj, M.; Guillon, D.; Skoulios, A.; Maldivi, P.; Giroud-Godquin, A. M.; Marchon, J.-C.

1992-12-01

EXAFS was used to investigate the local structure of the polar spines of rhodium (II) soaps in the columnar liquid crystalline state. It was also used to ascertain the degree of blending of the cores in binary mixtures of rhodium (II) and copper (II) soaps. For the pure rhodium soaps, the columns are shown to result from the stacking of binuclear metal-metal bonded dirhodium tetracarboxylate units bonded to one another by apical ligation of the metal atom of each complex with one of the oxygen atoms of the adjacent molecule. Mixtures of rhodium (II) and copper (II) soaps give a hexagonal columnar mesophase in which pure rhodium and pure copper columns are randomly distributed.

Columnar mesophases of hexabenzocoronene derivatives. II. Charge carrier mobility.

PubMed

Kirkpatrick, James; Marcon, Valentina; Kremer, Kurt; Nelson, Jenny; Andrienko, Denis

2008-09-07

Combining atomistic molecular dynamic simulations, Marcus-Hush theory description of charge transport rates, and master equation description of charge dynamics, we correlate the temperature-driven change of the mesophase structure with the change of charge carrier mobilities in columnar phases of hexabenzocoronene derivatives. The time dependence of fluctuations in transfer integrals shows that static disorder is predominant in determining charge transport characteristics. Both site energies and transfer integrals are distributed because of disorder in the molecular arrangement. It is shown that the contributions to the site energies from polarization and electrostatic effects are of opposite sign for positive charges. We look at three mesophases of hexabenzocoronene: herringbone, discotic, and columnar disordered. All results are compared to time resolved microwave conductivity data and show excellent agreement with no fitting parameters.

Dense zig-zag microstructures in YSZ thin films by pulsed laser deposition

NASA Astrophysics Data System (ADS)

Stender, Dieter; Schäuble, Nina; Weidenkaff, Anke; Montagne, Alex; Ghisleni, Rudy; Michler, Johann; Schneider, Christof W.; Wokaun, Alexander; Lippert, Thomas

2015-01-01

The very brittle oxygen ion conductor yttria stabilized zirconia (YSZ) is a typical solid electrolyte for miniaturized thin film fuel cells. In order to decrease the fuel cell operating temperature, the thickness of yttria stabilized zirconia thin films is reduced. Often, these thin membranes suffer from mechanical failure and gas permeability. To improve these mechanical issues, a glancing angle deposition approach is used to grow yttria stabilized zirconia thin films with tilted columnar structures. Changes of the material flux direction during the deposition result in a dense, zigzag-like structure with columnar crystallites. This structure reduces the elastic modulus of these membranes as compared to columnar yttria stabilized zirconia thin films as monitored by nano-indentation which makes them more adaptable to applied stress.

Transitional basal cells at the squamous-columnar junction generate Barrett’s oesophagus

PubMed Central

Jiang, Ming; Li, Haiyan; Zhang, Yongchun; Yang, Ying; Lu, Rong; Liu, Kuancan; Lin, Sijie; Lan, Xiaopeng; Wang, Haikun; Wu, Han; Zhu, Jian; Zhou, Zhongren; Xu, Jianming; Lee, Dong-Kee; Zhang, Lanjing; Lee, Yuan-Cho; Yuan, Jingsong; Abrams, Julian A.; Wang, Timothy G.; Sepulveda, Antonia R.; Wu, Qi; Chen, Huaiyong; Sun, Xin; She, Junjun; Chen, Xiaoxin; Que, Jianwen

2017-01-01

In several organ systems the transitional zone between different types of epithelia is a hotspot for pre-neoplastic metaplasia and malignancy1–3. However, the cell-of-origin for the metaplastic epithelium and subsequent malignancy, remains obscure1–3. In the case of Barrett’s oesophagus (BE), intestinal metaplasia occurs at the gastro-oesophageal junction, where stratified squamous epithelium transitions into simple columnar cells4. Based on different experimental models, several alternative cell types have been proposed as the source of the metaplasia, but in all cases the evidence is inconclusive and no model completely mimics BE with the presence of intestinal goblet cells5–8. Here, we describe a novel transitional columnar epithelium with distinct basal progenitor cells (p63+ KRT5+ KRT7+) in the squamous-columnar junction (SCJ) in the upper gastrointestinal tract of the mouse. We use multiple models and lineage tracing strategies to show that this unique SCJ basal cell population serves as a source of progenitors for the transitional epithelium. Moreover, upon ectopic expression of CDX2 these transitional basal progenitors differentiate into intestinal-like epithelium including goblet cells, thus reproducing Barrett’s metaplasia. A similar transitional columnar epithelium is present at the transitional zones of other mouse tissues, including the anorectal junction, and, importantly, at the gastro-oesophageal junction in the human gut. Acid reflux-induced oesophagitis and the multilayered epithelium (MLE) believed to be a precursor of BE are both characterized by the expansion of the transitional basal progenitor cells. Taken together our findings reveal the presence of a previously unidentified transitional zone in the epithelium of the upper gastrointestinal tract and provide evidence that the p63+ KRT7+ basal cells in this zone are the cell-of-origin for MLE and BE. PMID:29019984

Differentiation of anchoring junctions in tracheal basal cells in the growing rat.

PubMed

Evans, M J; Cox, R A; Burke, A S; Moller, P C

1992-02-01

A function of airway basal cells is to attach ciliated and nonciliated columnar cells to the basal lamina. The significance of the basal cell in attachment is related to the height of the columnar epithelium. In taller epithelia, basal cells are more numerous and differentiated with respect to anchoring junctional adhesion mechanisms (desmosomes, hemidesmosomes, and the cytoskeleton) than in shorter epithelia. In this study, we determined if basal cell anchoring junctional adhesion mechanisms differentiated during growth of the airway. Tracheas from five 3-day-old, five 30-day-old, and five 90-day-old rats were prepared for electron microscopy and morphometrically studied by standard techniques. The circumference of the trachea increased from 2.5 +/- 0.2 to 7.5 +/- 0.4 mm during growth. The height of the columnar cell increased from 13.4 +/- 1.5 to 24.6 +/- 3.9 microns, and the number of basal cells per millimeter increased from 3.2 +/- 0.7 to 9.6 +/- 1.8 during growth. The number of desmosomes per basal cell profile increased significantly from 1.5 +/- 0.1 to 2.1 +/- 0.1, as did keratin filament volume density from 0.046 +/- 0.05 to 0.098 +/- 0.032. The amount of hemidesmosome attachment per basal cell did not increase significantly during growth of the airway. These data demonstrate that as tracheas grow in circumference, the columnar cells increase in height, basal cells increase in number, and anchoring junctional adhesion mechanisms differentiate in the basal cells. These changes are closely related to the height of the epithelium and result in maintaining a constant amount of attachment between the columnar epithelium and the basal lamina as the epithelium increases in height.

Effect of Pseudomonas sp. MT5 baths on Flavobacterium columnare infection of rainbow trout and on microbial diversity on fish skin and gills.

PubMed

Suomalainen, L R; Tiirola, M A; Valtonen, E T

2005-01-25

Use of Pseudomonas sp. strain MT5 to prevent and treat Flavobacterium columnare infection was studied in 2 experiments with fingerling rainbow trout Oncorhynchus mykiss. In the first experiment, length heterogeneity analysis of PCR-amplified DNA fragments (LH-PCR) was used to assess the effect of antagonistic baths on the microbial diversity of healthy and experimentally infected fish. In the 148 samples studied, no difference was found between bathed and unbathed fish, and 3 fragment lengths were detected most frequently: 500 (in 75.7% of the samples), 523 (62.2%) and 517 bp (40.5%). The species contributing to these fragment sizes were Pseudomonas sp., Rhodococcus sp. and F. columnare, respectively. A specific PCR for detection of Pseudomonas sp. MT5 was designed, but none of the tissue samples were found to be positive, most likely indicating poor adhesion of the strain during bathing. LH-PCR was found to be a more powerful tool for detecting F. columnare in fish tissue than traditional culture methods (chi2 = 3.9, df = 1, p < 0.05). Antagonistic baths had no effect on the outbreak of infection or on fish mortality. F. columnare was also detected in healthy fish prior to and after experimental infection, indicating that these fish were carriers of the disease. In the second experiment, intensive Pseudomonas sp. MT5 antagonistic baths were given daily to rainbow trout suffering from a natural columnaris infection. Again, the antagonistic bacteria had no effect on fish mortality, which reached 95 % in both control and antagonist-treated groups in 7 d.

Columnaris disease in fish: a review with emphasis on bacterium-host interactions

PubMed Central

2013-01-01

Flavobacterium columnare (F. columnare) is the causative agent of columnaris disease. This bacterium affects both cultured and wild freshwater fish including many susceptible commercially important fish species. F. columnare infections may result in skin lesions, fin erosion and gill necrosis, with a high degree of mortality, leading to severe economic losses. Especially in the last decade, various research groups have performed studies aimed at elucidating the pathogenesis of columnaris disease, leading to significant progress in defining the complex interactions between the organism and its host. Despite these efforts, the pathogenesis of columnaris disease hitherto largely remains unclear, compromising the further development of efficient curative and preventive measures to combat this disease. Besides elaborating on the agent and the disease it causes, this review aims to summarize these pathogenesis data emphasizing the areas meriting further investigation. PMID:23617544

Orientation decoding depends on maps, not columns

PubMed Central

Freeman, Jeremy; Brouwer, Gijs Joost; Heeger, David J.; Merriam, Elisha P.

2011-01-01

The representation of orientation in primary visual cortex (V1) has been examined at a fine spatial scale corresponding to the columnar architecture. We present functional magnetic resonance imaging (fMRI) measurements providing evidence for a topographic map of orientation preference in human V1 at a much coarser scale, in register with the angular-position component of the retinotopic map of V1. This coarse-scale orientation map provides a parsimonious explanation for why multivariate pattern analysis methods succeed in decoding stimulus orientation from fMRI measurements, challenging the widely-held assumption that decoding results reflect sampling of spatial irregularities in the fine-scale columnar architecture. Decoding stimulus attributes and cognitive states from fMRI measurements has proven useful for a number of applications, but our results demonstrate that the interpretation cannot assume decoding reflects or exploits columnar organization. PMID:21451017

Oxidation of Peptides by Methyl(trifluoromethyl)dioxirane: the Protecting Group Matters

PubMed Central

Rella, Maria Rosaria; Williard, Paul G.

2011-01-01

Representative Boc protected and acetyl protected peptide methyl esters bearing alkyl side chains undergo effective oxidation using methyl(trifluoromethyl)dioxirane (1b) under mild conditions. We observe a protecting group dependency in the chemoselectivity displayed by the dioxirane 1b. N-hydroxylation occurs in the case of the Boc protected peptides, side chain hydroxylation takes place in the case of acetyl protected peptides. Both are attractive transformations since they yield derivatized peptides that serve as valuable synthons. PMID:17221970

The diagnosis and management of pre-invasive breast disease: Flat epithelial atypia – classification, pathologic features and clinical significance

PubMed Central

Schnitt, Stuart J

2003-01-01

Flat epithelial atypia is a descriptive term that encompasses lesions of the breast terminal duct lobular units in which variably dilated acini are lined by one to several layers of epithelial cells, which are usually columnar in shape and which display low-grade cytologic atypia. Observational studies have suggested that at least some of these lesions may represent either a precursor of ductal carcinoma in situ (DCIS) or the earliest morphological manifestation of DCIS. In contrast, the limited available clinical follow-up data suggest that the risk of both local recurrence and progression of these lesions to invasive cancer is extremely low, supporting the notion that categorizing such lesions as 'clinging carcinoma' and managing them as if they were fully developed DCIS will result in overtreatment of many patients. Additional studies are needed to better understand the biological nature and clinical significance of these lesions. PMID:12927037

Corrected Article: Simulation and observation of line-slip structures in columnar structures of soft spheres [Phys. Rev. E 96, 012610 (2017)

NASA Astrophysics Data System (ADS)

Winkelmann, J.; Haffner, B.; Weaire, D.; Mughal, A.; Hutzler, S.

2017-07-01

We present the computed phase diagram of columnar structures of soft spheres under pressure, of which the main feature is the appearance and disappearance of line slips, the shearing of adjacent spirals, as pressure is increased. A comparable experimental observation is made on a column of bubbles under forced drainage, clearly exhibiting the expected line slip.

Efficacy of florfenicol, copper sulfate and potassium permanganate in controlling a natural infection of Aeromonas hydrophila and Flavobacterium columnare in sunshine bass, Morone chrysops female x Morone saxatilis male

USDA-ARS?s Scientific Manuscript database

Sunshine bass (Morone chrysops female ' Morone saxatilis male) naturally infected with Aeromonas hydrophila and Flavobacterium columnare were randomly assigned to six treatments: 1) two treatments of waterborne exposures to copper sulfate (CuSO4), at 2.1 and at 4.2 mg/L (approximately one and two pe...

Do breast columnar cell lesions with atypia need to be excised?

PubMed

Datrice, Nicole; Narula, Navneet; Maggard, Melinda; Butler, John; Hsiang, David; Baick, Choong; Lane, Karen

2007-10-01

Columnar cell lesion with atypia (CCLA) is a newly recognized pathologic entity seen in breast specimens. The breast cancer risk associated with this finding is unclear, although CCLA had been found adjacent to both in situ and invasive carcinomas, but the incidence is unknown. Breast specimens from patients with a columnar cell lesion were reviewed by a pathologist for atypia. Twenty-one specimens with CCLA were identified [core biopsy (8), excisional biopsy (11), and simple mastectomy (2)]. Six of eight specimens with CCLA on core had adjacent abnormal pathology: infiltrating ductal carcinoma (IDC)/lobular carcinoma in situ (LCIS) (1), ductal carcinoma in situ (DCIS)/LCIS (1), DCIS (1), LCIS (1), and papillomatosis (2). Five of 11 specimens with CCLA on excisional biopsy had adjacent abnormal pathology: IDC (3), DCIS/LCIS (1), and atypical ductal hyperplasia/papilloma (1). Two of two simple mastectomy specimens had CCLA associated with IDC (1) and DCIS (1). Overall, abnormal pathology was found adjacent to CCLA in 62 per cent of specimens (13/21). Breast pathologic specimens containing a columnar cell lesion should be carefully examined for atypia. Surgical excision is warranted for CCLA found on core biopsy. The future risk of breast cancer based on the finding of CCLA alone requires further investigation.

Methylation of DAPK and THBS1 genes in esophageal gastric-type columnar metaplasia

PubMed Central

Herrera-Goepfert, Roberto; Oñate-Ocaña, Luis F; Mosqueda-Vargas, José Luis; Herrera, Luis A; Castro, Clementina; Mendoza, Julia; González-Barrios, Rodrigo

2016-01-01

AIM: To explore methylation of DAPK, THBS1, CDH-1, and p14 genes, and Helicobacter pylori (H. pylori) status in individuals harboring esophageal columnar metaplasia. METHODS: Distal esophageal mucosal samples obtained by endoscopy and histologically diagnosed as gastric-type (non-specialized) columnar metaplasia, were studied thoroughly. DNA was extracted from paraffin blocks, and methylation status of death-associated protein kinase (DAPK), thrombospondin-1 (THBS1), cadherin-1 (CDH1), and p14 genes, was examined using a methyl-sensitive polymerase chain reaction (MS-PCR) and sodium bisulfite modification protocol. H. pylori cagA status was determined by PCR. RESULTS: In total, 68 subjects (33 females and 35 males), with a mean age of 52 years, were included. H. pylori cagA positive was present in the esophageal gastric-type metaplastic mucosa of 18 individuals. DAPK, THSB1, CDH1, and p14 gene promoters were methylated by MS-PCR in 40 (58.8%), 33 (48.5%), 46 (67.6%), and 23 (33.8%) cases of the 68 esophageal samples. H. pylori status was associated with methylation of DAPK (P = 0.003) and THBS1 (P = 0.019). CONCLUSION: DNA methylation occurs in cases of gastric-type (non-specialized) columnar metaplasia of the esophagus, and this modification is associated with H. pylori cagA positive infection. PMID:27182166

Orientation Dependence of Columnar Dendritic Growth with Sidebranching Behaviors in Directional Solidification: Insights from Phase-Field Simulations

NASA Astrophysics Data System (ADS)

Xing, Hui; Dong, Xianglei; Wang, Jianyuan; Jin, Kexin

2018-04-01

In this study, a thin-interface phase-field model was employed to study the orientation dependence of the columnar dendritic growth with sidebranching behaviors in directional solidification. It was found that the dimensionless tip undercooling increases with the increase of misorientation angle for three pulling velocities. The primary spacing is found to be a function of misorientation angle, and the dimensionless primary spacing with respect to the misorientation angle follows the orientation correction given by Gandin and Rappaz (Acta. Metall. 42:2233-2246, 1994). For the analysis of the dendritic tip, the two-dimensional (2-D) form of the nonaxisymmetric needle crystal was used to determine the radius of the tilted columnar dendrite. Based on the definitions of open side and constrained side of the dendrite, the analysis of the width active sidebranches and the dendritic area in 2-D with respect to the distance from the dendritic tip was carried out to investigate the asymmetrical dendrite envelop and sidebranching behaviors on the two sides in directional solidification. The obtained prefactor and exponent with respect to misorientation angle are discussed, showing that the sidebranching behaviors of a tilted columnar dendritic array obey a similar power-law relationship with that of a free dendritic growth.

Immunohistochemical/histochemical double staining method in the study of the columnar metaplasia of the oesophagus.

PubMed

Cabibi, D; Giannone, A G; Mascarella, C; Guarnotta, C; Castiglia, M; Pantuso, G; Fiorentino, E

2014-03-05

Intestinal metaplasia in Barrett's oesophagus (BO) represents an important risk factor for oesophageal adenocarcinoma. Instead, few and controversial data are reported about the progression risk of columnar-lined oesophagus without intestinal metaplasia (CLO), posing an issue about its clinical management. The aim was to evaluate if some immunophenotypic changes were present in CLO independently of the presence of the goblet cells. We studied a series of oesophageal biopsies from patients with endoscopic finding of columnar metaplasia, by performing some immunohistochemical stainings (CK7, p53, AuroraA) combined with histochemistry (Alcian-blue and Alcian/PAS), with the aim of simultaneously assess the histochemical features in cells that shows an aberrant expression of such antigens. We evidenced a cytoplasmic expression of CK7 and a nuclear expression of Aurora A and p53,  both in goblet cells of BO and in non-goblet cells of CLO, some of which showing mild dysplasia. These findings suggest that some immunophenotypic changes are present in CLO and they can precede the appearance of the goblet cells or can be present independently of them, confirming the conception of BO as the condition characterized by any extention of columnar epithelium. This is the first study in which a combined immunohistochemical/histochemical method has been applied to Barrett pathology.

Microstructural Architecture, Microstructures, and Mechanical Properties for a Nickel-Base Superalloy Fabricated by Electron Beam Melting

NASA Astrophysics Data System (ADS)

Murr, L. E.; Martinez, E.; Gaytan, S. M.; Ramirez, D. A.; Machado, B. I.; Shindo, P. W.; Martinez, J. L.; Medina, F.; Wooten, J.; Ciscel, D.; Ackelid, U.; Wicker, R. B.

2011-11-01

Microstructures and a microstructural, columnar architecture as well as mechanical behavior of as-fabricated and processed INCONEL alloy 625 components produced by additive manufacturing using electron beam melting (EBM) of prealloyed precursor powder are examined in this study. As-fabricated and hot-isostatically pressed ("hipped") [at 1393 K (1120 °C)] cylinders examined by optical metallography (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive (X-ray) spectrometry (EDS), and X-ray diffraction (XRD) exhibited an initial EBM-developed γ″ (bct) Ni3Nb precipitate platelet columnar architecture within columnar [200] textured γ (fcc) Ni-Cr grains aligned in the cylinder axis, parallel to the EBM build direction. Upon annealing at 1393 K (1120 °C) (hot-isostatic press (HIP)), these precipitate columns dissolve and the columnar, γ, grains recrystallized forming generally equiaxed grains (with coherent {111} annealing twins), containing NbCr2 laves precipitates. Microindentation hardnesses decreased from 2.7 to 2.2 GPa following hot-isostatic pressing ("hipping"), and the corresponding engineering (0.2 pct) offset yield stress decreased from 0.41 to 0.33 GPa, while the UTS increased from 0.75 to 0.77 GPa. However, the corresponding elongation increased from 44 to 69 pct for the hipped components.

High frequency of coexistence of columnar cell lesions, lobular neoplasia, and low grade ductal carcinoma in situ with invasive tubular carcinoma and invasive lobular carcinoma.

PubMed

Abdel-Fatah, Tarek M A; Powe, Desmond G; Hodi, Zsolt; Lee, Andrew H S; Reis-Filho, Jorge S; Ellis, Ian O

2007-03-01

This study was undertaken to determine the morphologic features and frequency of putative precursor lesions involved in the development of some pure forms of special types and low grade breast carcinoma. We reviewed 147 successive tumor cases, comprising tubular carcinoma (TC); pure type (n=56) and mixed type (n=20), invasive lobular carcinoma (ILC); classic type (n=57), and tubulolobular carcinoma (TLC; n=14). The presence of preinvasive lesions including columnar cell lesions (CCLs), usual epithelial hyperplasia, ductal carcinoma in situ (DCIS), and lobular neoplasia (LN) was determined. Estrogen receptor and E-cadherin immunohistochemistry was performed. Ninety-five percent (95%) of pure TCs had associated CCLs with the majority showing flat epithelial atypia. Atypical ductal hyperplasia (ADH)/DCIS was present in 89% patients. Colocalization of CCL, ADH/DCIS, and TC was seen in 85% patients, all displaying the same cytologic-nuclear morphology in most cases. LN was seen in 16%. In ILC, 91% cases showed LN. CCL and ADH/DCIS were seen in 60% and 42% cases, respectively. E-cadherin was positive in TLC but reduced in TC and completely absent in ILC. In conclusion, our findings support the hypothesis that CCLs are associated with pure and mixed forms of TC, and that LN is involved in ILC development. Our observations suggest that these lesions represent family members of low grade precursor, in situ and invasive neoplastic lesions of the breast. Molecular studies are being performed to substantiate the hypothesis that tubular and lobular carcinomas have direct evolutionary links to CCLs and flat epithelial atypia.

Characterization of squamous esophageal cells resistant to bile acids at acidic pH: implication for Barrett's esophagus pathogenesis

PubMed Central

Goldman, Aaron; Chen, Hwu Dau Rw; Roesly, Heather B.; Hill, Kimberly A.; Tome, Margaret E.; Dvorak, Bohuslav; Bernstein, Harris

2011-01-01

Barrett's esophagus (BE) is a premalignant condition, where normal squamous epithelium is replaced by intestinal epithelium. BE is associated with an increased risk of developing esophageal adenocarcinoma (EAC). However, the BE cell of origin is not clear. We hypothesize that BE tissue originates from esophageal squamous cells, which can differentiate to columnar cells as a result of repeated exposure to gastric acid and bile acids, two components of refluxate implicated in BE pathology. To test this hypothesis, we repeatedly exposed squamous esophageal HET1A cells to 0.2 mM bile acid (BA) cocktail at pH 5.5 and developed an HET1AR-resistant cell line. These cells are able to survive and proliferate after repeated 2-h treatments with BA at pH 5.5. HET1AR cells are resistant to acidification and express markers of columnar differentiation, villin, CDX2, and cytokeratin 8/18. HET1AR cells have increased amounts of reactive oxygen species, concomitant with a decreased level and activity of manganese superoxide dismutase compared with parental cells. Furthermore, HET1AR cells express proteins and activate signaling pathways associated with inflammation, cell survival, and tumorigenesis that are thought to contribute to BE and EAC development. These include STAT3, NF-κB, epidermal growth factor receptor (EGFR), cyclooxygenase-2, interleukin-6, phosphorylated mammalian target of rapamycin (p-mTOR), and Mcl-1. The expression of prosurvival and inflammatory proteins and resistance to cell death could be partially modified by inhibition of STAT3 signaling. In summary, our study shows that long-term exposure of squamous cells to BA at acidic pH causes the cells to display the same characteristics and markers as BE. PMID:21127259

Controlling surface-segregation of a polymer to display carboxy groups on an outermost surface using perfluoroacyl groups.

PubMed

Nishimori, Keisuke; Kitahata, Shigeru; Nishino, Takashi; Maruyama, Tatsuo

2018-05-10

Controlling the surface properties of solid polymers is important for practical applications. We here succeeded in controlling the surface segregation of polymers to display carboxy groups on an outermost surface, which allowed the covalent immobilization of functional molecules via the carboxy groups on a substrate surface. Random methacrylate-based copolymers containing carboxy groups, in which carboxy groups were protected with perfluoroacyl (Rf) groups, were dip-coated on acrylic substrate surfaces. X-ray photoelectron spectroscopy and contact-angle measurements revealed that the Rf groups were segregated to the outermost surface of the dip-coated substrates. The Rf groups were removed by hydrolysis of the Rf esters in the copolymers, resulting in the display of carboxy groups on the surface. The quantification of carboxy groups on a surface revealed that the carboxy groups were reactive to a water-soluble solute in aqueous solution. The surface segregation was affected by the molecular structure of the copolymer used for dip-coating.

Three-dimensional quantitative structure-activity relationship modeling of cocaine binding by a novel human monoclonal antibody.

PubMed

Paula, Stefan; Tabet, Michael R; Farr, Carol D; Norman, Andrew B; Ball, W James

2004-01-01

Human monoclonal antibodies (mAbs) designed for immunotherapy have a high potential for avoiding the complications that may result from human immune system responses to the introduction of nonhuman mAbs into patients. This study presents a characterization of cocaine/antibody interactions that determine the binding properties of the novel human sequence mAb 2E2 using three-dimensional quantitative structure-activity relationship (3D-QSAR) methodology. We have experimentally determined the binding affinities of mAb 2E2 for cocaine and 38 cocaine analogues. The K(d) of mAb 2E2 for cocaine was 4 nM, indicating a high affinity. Also, mAb 2E2 displayed good cocaine specificity, as reflected in its 10-, 1500-, and 25000-fold lower binding affinities for the three physiologically relevant cocaine metabolites benzoylecgonine, ecgonine methyl ester, and ecgonine, respectively. 3D-QSAR models of cocaine binding were developed by comparative molecular similarity index analysis (CoMSIA). A model of high statistical quality was generated showing that cocaine binds to mAb 2E2 in a sterically restricted binding site that leaves the methyl group attached to the ring nitrogen of cocaine solvent-exposed. The methyl ester group of cocaine appears to engage in attractive van der Waals interactions with mAb 2E2, whereas the phenyl group contributes to the binding primarily via hydrophobic interactions. The model further indicated that an increase in partial positive charge near the nitrogen proton and methyl ester carbonyl group enhances binding affinity and that the ester oxygen likely forms an intermolecular hydrogen bond with mAb 2E2. Overall, the cocaine binding properties of mAb 2E2 support its clinical potential for development as a treatment of cocaine overdose and addiction.

A coumaroyl-ester-3-hydroxylase Insertion Mutant Reveals the Existence of Nonredundant meta-Hydroxylation Pathways and Essential Roles for Phenolic Precursors in Cell Expansion and Plant Growth1[W][OA

PubMed Central

Abdulrazzak, Nawroz; Pollet, Brigitte; Ehlting, Jürgen; Larsen, Kim; Asnaghi, Carole; Ronseau, Sebastien; Proux, Caroline; Erhardt, Mathieu; Seltzer, Virginie; Renou, Jean-Pierre; Ullmann, Pascaline; Pauly, Markus; Lapierre, Catherine; Werck-Reichhart, Danièle

2006-01-01

Cytochromes P450 monooxygenases from the CYP98 family catalyze the meta-hydroxylation step in the phenylpropanoid biosynthetic pathway. The ref8 Arabidopsis (Arabidopsis thaliana) mutant, with a point mutation in the CYP98A3 gene, was previously described to show developmental defects, changes in lignin composition, and lack of soluble sinapoyl esters. We isolated a T-DNA insertion mutant in CYP98A3 and show that this mutation leads to a more drastic inhibition of plant development and inhibition of cell growth. Similar to the ref8 mutant, the insertion mutant has reduced lignin content, with stem lignin essentially made of p-hydroxyphenyl units and trace amounts of guaiacyl and syringyl units. However, its roots display an ectopic lignification and a substantial proportion of guaiacyl and syringyl units, suggesting the occurrence of an alternative CYP98A3-independent meta-hydroxylation mechanism active mainly in the roots. Relative to the control, mutant plantlets produce very low amounts of sinapoyl esters, but accumulate flavonol glycosides. Reduced cell growth seems correlated with alterations in the abundance of cell wall polysaccharides, in particular decrease in crystalline cellulose, and profound modifications in gene expression and homeostasis reminiscent of a stress response. CYP98A3 thus constitutes a critical bottleneck in the phenylpropanoid pathway and in the synthesis of compounds controlling plant development. CYP98A3 cosuppressed lines show a gradation of developmental defects and changes in lignin content (40% reduction) and structure (prominent frequency of p-hydroxyphenyl units), but content in foliar sinapoyl esters is similar to the control. The purple coloration of their leaves is correlated to the accumulation of sinapoylated anthocyanins. PMID:16377748

Isolation, identification and antioxidant activity of bound phenolic compounds present in rice bran.

PubMed

Wang, Wei; Guo, Jia; Zhang, Junnan; Peng, Jie; Liu, Tianxing; Xin, Zhihong

2015-03-15

The bound phenolic compounds in rice bran were released and extracted with ethyl acetate based on alkaline digestion. An investigation of the chemical constituents of EtOAc extract has led to the isolation of a new compound, para-hydroxy methyl benzoate glucoside (8), together with nine known compounds, cycloeucalenol cis-ferulate (1), cycloeucalenol trans-ferulate (2), trans-ferulic acid (3), trans-ferulic acid methyl ester (4), cis-ferulic acid (5), cis-ferulic acid methyl ester (6), methyl caffeate (7), vanillic aldehyde (9) and para-hydroxy benzaldehyde (10). The structures of these compounds were determined using a combination of spectroscopic methods and chemical analysis. Among the compounds isolated, compound 3, 5 and 7 exhibited strong DPPH and ABTS(+) radical scavenging activities, followed by compounds 4 and 6. Compound 1 and 2 showed potent DPPH and ABTS(+) radical scavenging activities, compound 8 displayed moderate antioxidant activity against ABTS(+) radical, whereas compound 9 and 10 showed weak antioxidant activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

3D Microstructural Architectures for Metal and Alloy Components Fabricated by 3D Printing/Additive Manufacturing Technologies

NASA Astrophysics Data System (ADS)

Martinez, E.; Murr, L. E.; Amato, K. N.; Hernandez, J.; Shindo, P. W.; Gaytan, S. M.; Ramirez, D. A.; Medina, F.; Wicker, R. B.

The layer-by-layer building of monolithic, 3D metal components from selectively melted powder layers using laser or electron beams is a novel form of 3D printing or additive manufacturing. Microstructures created in these 3D products can involve novel, directional solidification structures which can include crystallographically oriented grains containing columnar arrays of precipitates characteristic of a microstructural architecture. These microstructural architectures are advantageously rendered in 3D image constructions involving light optical microscopy and scanning and transmission electron microscopy observations. Microstructural evolution can also be effectively examined through 3D image sequences which, along with x-ray diffraction (XRD) analysis in the x-y and x-z planes, can effectively characterize related crystallographic/texture variances. This paper compares 3D microstructural architectures in Co-base and Ni-base superalloys, columnar martensitic grain structures in 17-4 PH alloy, and columnar copper oxides and dislocation arrays in copper.

Flat epithelial atypia of the breast: characteristics and behaviors.

PubMed

Sudarshan, Monisha; Meguerditchian, Ari-Nareg; Mesurolle, Benoit; Meterissian, Sarkis

2011-02-01

Flat epithelial atypia (FEA) increasingly is being recognized as a pathologic entity on core needle biopsies. However, definitive management of this columnar cell lesion remains debatable because its malignant potential is unknown. A PubMed search for "flat epithelial atypia" and "columnar cell lesions" was performed. FEA commonly was encountered in the background of higher-grade lesions such as atypical ductal hyperplasia, ductal carcinoma in situ, and tubular and lobular carcinomas. Its molecular and cytogenetic profile revealed some alterations similar to precancerous lesions. Pure FEA on core needle biopsies was upgraded to higher-grade lesions on subsequent surgical excision. Current management of FEA is best achieved through a multidisciplinary review considering various factors to determine if surgical excision is warranted. Further studies are required to elucidate the malignant potential of this columnar cell lesion. Copyright © 2011 Elsevier Inc. All rights reserved.

Preparing highly ordered glasses of discotic liquid crystalline systems by vapor deposition

NASA Astrophysics Data System (ADS)

Gujral, Ankit; Gomez, Jaritza; Bishop, Camille E.; Toney, Michael F.; Ediger, M. D.

Anisotropic molecular packing, particularly in highly ordered liquid-crystalline arrangements, has the potential for optimizing performance in organic electronic and optoelectronic applications. Here we show that physical vapor deposition can be used to prepare highly organized out-of-equilibrium (glassy) solids of discotic liquid-crystalline (LC) systems. Using grazing incidence x-ray scattering, we compare 3 systems: a rectangular columnar LC, a hexagonal columnar LC and a non-liquid crystal former. The packing motifs accessible by vapor deposition are highly organized and vary from face-on to edge-on columnar arrangements depending upon substrate temperature. A subset of these structures cannot be accessed under equilibrium conditions. The structures formed at a given substrate temperature can be understood as the result of the system partially equilibrating toward the structure of the free surface of the equilibrium liquid crystal. Consistent with this view, the structures formed are independent of the substrate material.

Vapor-Deposited Glasses with Long-Range Columnar Liquid Crystalline Order

DOE PAGES

Gujral, Ankit; Gomez, Jaritza; Ruan, Shigang; ...

2017-10-04

Anisotropic molecular packing, particularly in highly ordered liquid crystalline arrangements, has the potential for optimizing performance in organic electronic and optoelectronic applications. Here we show that physical vapor deposition can be used to prepare highly organized glassy solids of discotic liquid crystalline systems. Using grazing incidence X-ray scattering, atomic force microscopy, and UV–vis spectroscopy, we compare three systems: a rectangular columnar liquid crystal, a hexagonal columnar liquid crystal, and a nonmesogen. The packing motifs accessible by vapor deposition are highly organized for the liquid crystalline systems with columns propagating either in-plane or out-of-plane depending upon the substrate temperature during deposition.more » As a result, the structures formed at a given substrate temperature can be understood as resulting from partial equilibration toward the structure of the equilibrium liquid crystal surface during the deposition process.« less

Modelling the viscoplastic behavior and the heterogeneous intracrystalline deformation of columnar ice polycrystals

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

Lebensohn, Ricardo A; Montagnat, Maurine; Mansuy, Philippe

2008-01-01

A full-field formulation based on Fast Fourier Transforms (FFT) has been adapted and used to predict the micromechanical fields that develop in columnar Ih ice polycrystals deforming in compression by dislocation creep. The predicted intragranular mechanical fields are in qualitative good agreement with experimental observations, in particular those involving the formation of shear and kink bands. These localization bands are associated with the large internal stresses that develop during creep in such anisotropic material, and their location, intensity, morphology and extension are found to depend strongly on the crystallographic orientation of the grains and on their interaction with neighbor crystals.more » The predictions of the model are also discussed in relation with the deformation of columnar sea and lake ice, and with the mechanical behavior of granular ice of glaciers and polar ice sheets, as well.« less

Columnar to nematic mesophase transition in mixtures of rhodium or copper soaps with hydrocarbon solvents

NASA Astrophysics Data System (ADS)

Ibn-Elhaj, M.; Guillon, D.; Skoulios, A.; Giroud-Godquin, A. M.; Marchon, J.-C.

1992-12-01

This paper describes observations of the mesomorphic behaviour of mixtures of rhodium eicosanoate or copper dodecanoate with solvents such as toluene, decahydronaphthalene, and (+) camphene. The mesophase found with these compounds at high temperatures turns from columnar to nematic when the weight fraction of the solvent (toluene, decahydronaphthalene is increased beyond a value of about 50%. The binary phase diagram of the copper compound with toluene was experimentally determined using polarizing optical microscopy, differential scanning calorimetry and X-ray diffraction. The novel feature of the nematic phase is that the basic physical object which align parallel to the nematic director are not individual molecules, but columns of molecules (one-dimensional supramolecular assemblies) which have lost the long-range lateral positional order characteristic of the columnar mesophase. These observations are discussed on the grounds of recent theoretical calculations. Cholesteric-like textures are observed for mixtures of rhodium eicosanoate with the chiral solvent (+) camphene.

Vapor-Deposited Glasses with Long-Range Columnar Liquid Crystalline Order

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

Gujral, Ankit; Gomez, Jaritza; Ruan, Shigang

Anisotropic molecular packing, particularly in highly ordered liquid crystalline arrangements, has the potential for optimizing performance in organic electronic and optoelectronic applications. Here we show that physical vapor deposition can be used to prepare highly organized glassy solids of discotic liquid crystalline systems. Using grazing incidence X-ray scattering, atomic force microscopy, and UV–vis spectroscopy, we compare three systems: a rectangular columnar liquid crystal, a hexagonal columnar liquid crystal, and a nonmesogen. The packing motifs accessible by vapor deposition are highly organized for the liquid crystalline systems with columns propagating either in-plane or out-of-plane depending upon the substrate temperature during deposition.more » As a result, the structures formed at a given substrate temperature can be understood as resulting from partial equilibration toward the structure of the equilibrium liquid crystal surface during the deposition process.« less

Microstructure-related properties of magnesium fluoride films at 193nm by oblique-angle deposition.

PubMed

Guo, Chun; Kong, Mingdong; Lin, Dawei; Liu, Cunding; Li, Bincheng

2013-01-14

Magnesium fluoride (MgF2) films deposited by resistive heating evaporation with oblique-angle deposition have been investigated in details. The optical and micro-structural properties of single-layer MgF2 films were characterized by UV-VIS and FTIR spectrophotometers, scanning electron microscope (SEM), atomic force microscope (AFM), and x-ray diffraction (XRD), respectively. The dependences of the optical and micro-structural parameters of the thin films on the deposition angle were analyzed. It was found that the MgF2 film in a columnar microstructure was negatively inhomogeneous of refractive index and polycrystalline. As the deposition angle increased, the optical loss, extinction coefficient, root-mean-square (rms) roughness, dislocation density and columnar angle of the MgF2 films increased, while the refractive index, packing density and grain size decreased. Furthermore, IR absorption of the MgF2 films depended on the columnar structured growth.

Characterization of a small acyl-CoA-binding protein (ACBP) from Helianthus annuus L. and its binding affinities.

PubMed

Aznar-Moreno, Jose A; Venegas-Calerón, Mónica; Du, Zhi-Yan; Garcés, Rafael; Tanner, Julian A; Chye, Mee-Len; Martínez-Force, Enrique; Salas, Joaquín J

2016-05-01

Acyl-CoA-binding proteins (ACBPs) bind to acyl-CoA esters and promote their interaction with other proteins, lipids and cell structures. Small class I ACBPs have been identified in different plants, such as Arabidopsis thaliana (AtACBP6), Brassica napus (BnACBP) and Oryza sativa (OsACBP1, OsACBP2, OsACBP3), and they are capable of binding to different acyl-CoA esters and phospholipids. Here we characterize HaACBP6, a class I ACBP expressed in sunflower (Helianthus annuus) tissues, studying the specificity of its corresponding recombinant HaACBP6 protein towards various acyl-CoA esters and phospholipids in vitro, particularly using isothermal titration calorimetry and protein phospholipid binding assays. This protein binds with high affinity to de novo synthetized derivatives palmitoly-CoA, stearoyl-CoA and oleoyl-CoA (Kd 0.29, 0.14 and 0.15 μM respectively). On the contrary, it showed lower affinity towards linoleoyl-CoA (Kd 5.6 μM). Moreover, rHaACBP6 binds to different phosphatidylcholine species (dipalmitoyl-PC, dioleoyl-PC and dilinoleoyl-PC), yet it displays no affinity towards other phospholipids like lyso-PC, phosphatidic acid and lysophosphatidic acid derivatives. In the light of these results, the possible involvement of this protein in sunflower oil synthesis is considered. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Glycophenotype Evaluation in Cutaneous Tumors Using Lectins Labeled with Acridinium Ester

PubMed Central

Lima, Luiza Rayanna Amorim; Almeida, Sinara Mônica Vitalino; Silva, Lúcia Patrícia Bezerra Gomes; Beltrão, Eduardo Isidoro Carneiro; Carvalho Júnior, Luiz Bezerra

2013-01-01

Background. Tumor cells show alterations in their glycosylation patterns when compared to normal cells. Lectins can be used to evaluate these glycocode changes. Chemiluminescence assay is an effective technique for quantitative analysis of proteins, nucleic acids, and carbohydrates due to its high sensitivity, specificity, and rapid testing. Objective. To use histochemiluminescence based on lectin conjugated to acridinium ester (AE) for the investigation of glycophenotype changes in cutaneous tumors. Methods. Concanavalin A (Con A), Peanut agglutinin (PNA), Ulex europaeus agglutinin-I (UEA-I), and Maackia amurensis agglutinin (MAA) were conjugated to acridinium ester. Biopsies of cutaneous tumors and normal skin were incubated with the lectins-AE, and chemiluminescence was quantified and expressed as Relative Light Units (RLU). Results. Actinic keratosis (AK), keratoacanthoma (KA), squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) showed lower expression of α-D-glucose/mannose and α-L-fucose residues compared to normal tissue. Cutaneous tumors displayed higher expression of Gal-β(1-3)-GalNAc residues than normal tissue. AK and SCC exhibited higher expression of Neu5Ac-α(2,3)Gal residues than normal epidermis. KA and BCC showed equivalent RLU values compared to normal tissue. Conclusions. Lectin histochemiluminescence allowed quantitative assessment of the carbohydrate expression in cutaneous tissues, contributing to eliminate the subjectivity of conventional techniques used in the histopathological diagnosis. PMID:24167360

Are all eggs created equal? A case study from the Hawaiian reef-building coral Montipora capitata

NASA Astrophysics Data System (ADS)

Padilla-Gamiño, Jacqueline L.; Bidigare, Robert R.; Barshis, Daniel J.; Alamaru, Ada; Hédouin, Laetitia; Hernández-Pech, Xavier; Kandel, Frederique; Leon Soon, Sherril; Roth, Melissa S.; Rodrigues, Lisa J.; Grottoli, Andrea G.; Portocarrero, Claudia; Wagenhauser, Stephanie A.; Buttler, Fenina; Gates, Ruth D.

2013-03-01

Parental effects have been largely unexplored in marine organisms and may play a significant role in dictating the phenotypic range of traits in coral offspring, influencing their ability to survive environmental challenges. This study explored parental effects and life-stage differences in the Hawaiian reef-building coral Montipora capitata from different environments by examining the biochemical composition of mature coral colonies and their eggs. Our results indicate that there are large biochemical differences between adults and eggs, with the latter containing higher concentration of lipids (mostly wax esters), ubiquitinated proteins (which may indicate high turnover rate of proteins) and antioxidants (e.g., manganese superoxide dismutase). Adults displayed high phenotypic plasticity, with corals from a high-light environment having more wax esters, lighter tissue δ13C signatures and higher Symbiodinium densities than adults from the low-light environment who had higher content of accessory pigments. A green-algal pigment (α-carotene) and powerful antioxidant was present in eggs; it is unclear whether this pigment is acquired from heterotrophic food sources or from endolithic green algae living in the adult coral skeletons. Despite the broad phenotypic plasticity displayed by adults, parental investment in the context of provisioning of energy reserves and antioxidant defense was the same in eggs from the different sites. Such equality in investment maximizes the capacity of all embryos and larvae to cope with challenging conditions associated with floating at the surface and to disperse successfully until an appropriate habitat for settlement is found.

Lipoamidase activity in normal and mutagenized pancreatic cholesterol esterase (bile salt-stimulated lipase).

PubMed Central

Hui, D Y; Hayakawa, K; Oizumi, J

1993-01-01

Purified human milk lipoamidase was digested with endoproteinase Lys-C and the digested peptides were subjected to gasphase microsequence analysis. The sequencing of three isolated peptides of human milk lipoamidase revealed the identity of this protein with human milk bile salt-stimulated lipase (pancreatic cholesterol esterase). The identity of the cholesterol esterase with lipoamidase was confirmed by expressing a recombinant form of rat pancreatic cholesterol esterase and testing for lipoamidase activity of the recombinant protein. The results showed that the recombinant cholesterol esterase displayed both lipolytic and lipoamidase activities and was capable of hydrolysing triacetin and lipoyl-4-aminobenzoate (LPAB). The mechanisms of the esterase and amidase activities of the enzyme were further tested by determining enzyme activity in a mutagenized cholesterol esterase with a His435-->Gln435 substitution. This mutation has been shown previously to abolish enzyme activity against esterase substrates [DiPersio, Fontaine and Hui (1991) J. Biol. Chem. 266, 4033-4036]. We showed that the mutagenized protein was effective in hydrolysing the amidase substrate LPAB and displayed similar enzyme kinetics to those of the native enzyme. These data indicate that the mechanism for the cholesterol esterase hydrolysis of lipoamides is different from that of the hydrolysis of substrates with an ester linkage. The presence of an enzyme in the gastrointestinal tract capable of both ester and amide hydrolysis suggests an important role for this protein in the digestion and absorption processes. PMID:8471055

Neuronal control of locomotor handedness in Drosophila.

PubMed

Buchanan, Sean M; Kain, Jamey S; de Bivort, Benjamin L

2015-05-26

Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are nonheritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality.

Cortical Structure Alterations and Social Behavior Impairment in p50-Deficient Mice.

PubMed

Bonini, Sara Anna; Mastinu, Andrea; Maccarinelli, Giuseppina; Mitola, Stefania; Premoli, Marika; La Rosa, Luca Rosario; Ferrari-Toninelli, Giulia; Grilli, Mariagrazia; Memo, Maurizio

2016-06-01

Alterations in genes that regulate neurodevelopment can lead to cortical malformations, resulting in malfunction during postnatal life. The NF-κB pathway has a key role during neurodevelopment by regulating the maintenance of the neural progenitor cell pool and inhibiting neuronal differentiation. In this study, we evaluated whether mice lacking the NF-κB p50 subunit (KO) present alterations in cortical structure and associated behavioral impairment. We found that, compared with wild type (WT), KO mice at postnatal day 2 present an increase in radial glial cells, an increase in Reelin protein expression levels, in addition to an increase of specific layer thickness. Moreover, adult KO mice display abnormal columnar organization in the somatosensory cortex, a specific decrease in somatostatin- and parvalbumin-expressing interneurons, altered neurite orientation, and a decrease in Synapsin I protein levels. Concerning behavior, KO mice, in addition to an increase in locomotor and exploratory activity, display impairment in social behaviors, with a reduction in social interaction. Finally, we found that risperidone treatment decreased hyperactivity of KO mice, but had no effect on defective social interaction. Altogether, these data add complexity to a growing body of data, suggesting a link between dysregulation of the NF-κB pathway and neurodevelopmental disorders pathogenesis. © The Author 2016. Published by Oxford University Press.

Phage display of an intracellular carboxylesterase of Bacillus subtilis: comparison of Sec and Tat pathway export capabilities.

PubMed

Dröge, Melloney J; Boersma, Ykelien L; Braun, Peter G; Buining, Robbert Jan; Julsing, Mattijs K; Selles, Karin G A; van Dijl, Jan Maarten; Quax, Wim J

2006-07-01

Using the phage display technology, a protein can be displayed at the surface of bacteriophages as a fusion to one of the phage coat proteins. Here we describe development of this method for fusion of an intracellular carboxylesterase of Bacillus subtilis to the phage minor coat protein g3p. The carboxylesterase gene was cloned in the g3p-based phagemid pCANTAB 5E upstream of the sequence encoding phage g3p and downstream of a signal peptide-encoding sequence. The phage-bound carboxylesterase was correctly folded and fully enzymatically active, as determined from hydrolysis of the naproxen methyl ester with Km values of 0.15 mM and 0.22 mM for the soluble and phage-displayed carboxylesterases, respectively. The signal peptide directs the encoded fusion protein to the cell membrane of Escherichia coli, where phage particles are assembled. In this study, we assessed the effects of several signal peptides, both Sec dependent and Tat dependent, on the translocation of the carboxylesterase in order to optimize the phage display of this enzyme normally restricted to the cytoplasm. Functional display of Bacillus carboxylesterase NA could be achieved when Sec-dependent signal peptides were used. Although a Tat-dependent signal peptide could direct carboxylesterase translocation across the inner membrane of E. coli, proper assembly into phage particles did not seem to occur.

Columnar jointing - the mechanics of thermal contraction in cooling lavas

NASA Astrophysics Data System (ADS)

Lavallée, Y.; Iddon, F.; Hornby, A. J.; Kendrick, J. E.; von Aulock, F. W.; Wadsworth, F. B.

2014-12-01

Columnar joints are spectacular features of volcanic rocks, which form by cracking during cooling-induced contraction of lava. The process, and resultant geometry, manifests a complex interplay between heat dissipation, contraction and tensile strength, yet the formation temperature of such joints remains elusive. Here, we present results from a combination of field survey, thermo-analytical characterisation and mechanical investigation to constrain conditions favourable for columnar jointing. Columnar joints at Seljavellir, a basaltic lava flow at the base of Eyjafjallajökull volcano (Iceland) produce quadratic to heptagonal cross sectional patterns with column widths ranging from 20 to 70 cm in size. The fracture surfaces are characterised by striae with spacing (between 1 to 6 cm) that shares a positive linear relationship to the joint spacing. The striae exhibit both a rough and smooth portion, interpreted to express a change in deformation regime from a ductile response as stress builds up to a fully brittle, mode-I fracture propagation at high stress accumulation. To test the thermo-mechanics of columnar joints we developed an experimental setup to investigate the stress, strain-to-failure and temperature at which basalts undergo tensile failure during cooling from the solidus temperature of 980 °C. We find that fractures initiate at ~800 °C, revealed by a change in stress accumulation (i.e., Young modulus), and complete failure completes after some 0.4% strain at ~670 °C. We interpret the two-stage fracture dynamics as the cause for the change in fracture surface roughness observed in nature. We coupled this dataset with Brazil tensile tests at 30, 400, 600, 800 and 1000 °C. We note that the strain to failure decrease from 1% (>800 °C) to 0.4% (<800 °C). Complementary dilatometric measurements (at 3mN of normal stress and a rate of 2 C/min) constrain the expansion coefficient to be linear and equal to 10-5/°C below the solid temperature. Simple ratio between strain-to-failure and expansion coefficient suggests that 400 °C of cooling (from the solidus) is require to achieve tensile failure by thermal contraction, supporting the first suite of experiments. We conclude that columnar jointing is not a phenomenon that takes place in molten lava, but rather occurs well within the solid state of volcanic rocks.

Changes in solidified microstructures

NASA Technical Reports Server (NTRS)

Wallace, J. F.

1984-01-01

The properties and casting behavior of metals are significantly affected by their cast structure. This structure is optimized by producing columnar versus equiaxed grains and coarse versus fine grains by controlling solidification conditions. The transition from columnar to equiaxed grains is favored by: constitutional supercooling with effective nucleation of free dendrites; melting off and transport of dendrite tips and arms; mechanical vibration; falling down of free dendrites from a chilled top surface; and induced flow in the solidifying structure by oscillation of rotation.

A comparison of Argo nominal surface and near-surface temperature for validation of AMSR-E SST

NASA Astrophysics Data System (ADS)

Liu, Zenghong; Chen, Xingrong; Sun, Chaohui; Wu, Xiaofen; Lu, Shaolei

2017-05-01

Satellite SST (sea surface temperature) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) is compared with in situ temperature observations from Argo profiling floats over the global oceans to evaluate the advantages of Argo NST (near-surface temperature: water temperature less than 1 m from the surface). By comparing Argo nominal surface temperature ( 5 m) with its NST, a diurnal cycle caused by daytime warming and nighttime cooling was found, along with a maximum warming of 0.08±0.36°C during 14:00-15:00 local time. Further comparisons between Argo 5-m temperature/Argo NST and AMSR-E SST retrievals related to wind speed, columnar water vapor, and columnar cloud water indicate warming biases at low wind speed (<5 m/s) and columnar water vapor >28 mm during daytime. The warming tendency is more remarkable for AMSR-E SST/Argo 5-m temperature compared with AMSR-E SST/Argo NST, owing to the effect of diurnal warming. This effect of diurnal warming events should be excluded before validation for microwave SST retrievals. Both AMSR-E nighttime SST/Argo 5-m temperature and nighttime SST/Argo NST show generally good agreement, independent of wind speed and columnar water vapor. From our analysis, Argo NST data demonstrated their advantages for validation of satellite-retrieved SST.

Micron-sized columnar grains of CH3NH3PbI3 grown by solvent-vapor assisted low-temperature (75 °C) solid-state reaction: The role of non-coordinating solvent-vapor

NASA Astrophysics Data System (ADS)

Zheng, Huifeng; Liu, Yangqiao; Sun, Jing

2018-04-01

The preparation of hybrid perovskite films with large columnar grains via low-temperature solid-state reaction remains a big challenge. Conventional solvent annealing using DMF, DMSO and ethanol, etc. fails to work effectively at low temperature (<100 °C). Here, we comprehensively investigated the effects of non-coordinating solvent vapor on the properties of perovskite film, and obtained micron-sized columnar grains (with an average grain size of 1.4 μm) of CH3NH3PbI3 even at a low temperature of 75 °C when annealed with benzyl alcohol vapor. The perovskite solar cells based on benzyl-alcohol-vapor annealing (75 °C), delivered much higher photovoltaic performance, better stability and smaller hysteresis than those based on conventional thermal annealing. Additionally, a champion power conversion efficiency (PCE) of 15.1% was obtained and the average PCE reached 12.2% with a tiny deviation. Finally, the mechanism of solvent annealing with non-coordinating solvent was discussed. Moreover, we revealed that high polarity and high boiling point of the solvent used for generating vapor, was critical to grow micron-sized columnar grains at such a low temperature (75 °C). This work will contribute to understanding the mechanism of grain growth in solvent annealing and improving its facility and effectiveness.

Development of Columnar Topography in the Excitatory Layer 4 to Layer 2/3 Projection in Rat Barrel Cortex

PubMed Central

Bender, Kevin J.; Rangel, Juliana; Feldman, Daniel E.

2011-01-01

The excitatory feedforward projection from layer (L) 4 to L2/3 in rat primary somatosensory (S1) cortex exhibits precise, columnar topography that is critical for columnar processing of whisker inputs. Here, we characterize the development of axonal topography in this projection using single-cell reconstructions in S1 slices. In the mature projection [postnatal day (P) 14 –26], axons of L4 cells extending into L2/3 were confined almost entirely to the home barrel column, consistent with previous results. At younger ages (P8 –11), however, axonal topography was significantly less columnar, with a large proportion of branches innervating neighboring barrel columns representing adjacent whisker rows. Mature topography developed from this initial state by targeted axonal growth within the home column and by growth of barrel columns themselves. Raising rats with all or a subset of whiskers plucked from P8 –9, manipulations that induce reorganization of functional whisker maps and synaptic depression at L4 to L2/3 synapses, did not alter normal anatomical development of L4 to L2/3 axons. Thus, development of this projection does not require normal sensory experience after P8, and deprivation-induced reorganization of whisker maps at this age is unlikely to involve physical remodeling of L4 to L2/3 axons. PMID:14507976

Activation of Wnt Planar Cell Polarity (PCP) signaling promotes growth plate column formation in vitro.

PubMed

Randall, Rachel M; Shao, Yvonne Y; Wang, Lai; Ballock, R Tracy

2012-12-01

Disrupting the Wnt Planar Cell Polarity (PCP) signaling pathway in vivo results in loss of columnar growth plate architecture, but it is unknown whether activation of this pathway in vitro is sufficient to promote column formation. We hypothesized that activation of the Wnt PCP pathway in growth plate chondrocyte cell pellets would promote columnar organization in these cells that are normally oriented randomly in culture. Rat growth plate chondrocytes were transfected with plasmids encoding the Fzd7 cell-surface Wnt receptor, a Fzd7 deletion mutant lacking the Wnt-binding domain, or Wnt receptor-associated proteins Ror2 or Vangl2, and then cultured as three-dimensional cell pellets in the presence of recombinant Wnt5a or Wnt5b for 21 days. Cellular morphology was evaluated using histomorphometric measurements. Activation of Wnt PCP signaling components promoted the initiation of columnar morphogenesis in the chondrocyte pellet culture model, as measured by histomorphometric analysis of the column index (ANOVA p = 0.01). Activation of noncanonical Wnt signaling through overexpression of both the cell-surface Wnt receptor Fzd7 and receptor-associated protein Ror2 with addition of recombinant Wnt5a promotes the initiation of columnar architecture of growth plate chondrocytes in vitro, representing an important step toward growth plate regeneration. Copyright © 2012 Orthopaedic Research Society.

Stability of smectic phases in hard-rod mixtures

NASA Astrophysics Data System (ADS)

Martínez-Ratón, Yuri; Velasco, Enrique; Mederos, Luis

2005-09-01

Using density-functional theory, we have analyzed the phase behavior of binary mixtures of hard rods of different lengths and diameters. Previous studies have shown a strong tendency of smectic phases of these mixtures to segregate and, in some circumstances, to form microsegregated phases. Our focus in the present work is on the formation of columnar phases which some studies, under some approximations, have shown to become thermodynamically stable prior to crystallization. Specifically we focus on the relative stability between smectic and columnar phases, a question not fully addressed in previous work. Our analysis is based on two complementary perspectives: on the one hand, an extended Onsager theory, which includes the full orientational degrees of freedom but with spatial and orientational correlations being treated in an approximate manner; on the other hand, we formulate a Zwanzig approximation of fundamental-measure theory on hard parallelepipeds, whereby orientations are restricted to be only along three mutually orthogonal axes, but correlations are faithfully represented. In the latter case novel, complete phase diagrams containing regions of stability of liquid-crystalline phases are calculated. Our findings indicate that the restricted-orientation approximation enhances the stability of columnar phases so as to preempt smectic order completely while, in the framework of the extended Onsager model, with full orientational degrees of freedom taken into account, columnar phases may preempt a large region of smectic stability in some mixtures, but some smectic order still persists.

Dependence of columnar aerosol size distribution, optical properties, and chemical components on regional transport in Beijing

NASA Astrophysics Data System (ADS)

Wang, Shuo; Zhao, Weixiong; Xu, Xuezhe; Fang, Bo; Zhang, Qilei; Qian, Xiaodong; Zhang, Weijun; Chen, Weidong; Pu, Wei; Wang, Xin

2017-11-01

Seasonal dependence of the columnar aerosol optical and chemical properties on regional transport in Beijing over 10 years (from January 2005 to December 2014) were analyzed by using the ground-based remote sensing combined with backward trajectory analysis. Daily air mass backward trajectories terminated in Beijing were computed with HYSPLIT-4 model and were categorized into five clusters. The columnar mass concentrations of black carbon (BC), brown carbon (BrC), dust (DU), aerosol water content (AW), and ammonium sulfate like aerosol (AS) of each cluster were retrieved from the optical data obtained from the Aerosol Robotic NETwork (AERONET) with five-component model. It was found that the columnar aerosol properties in different seasons were changed, and they were related to the air mass origins. In spring, aerosol was dominated by coarse particles. Summer was characterized by higher single scattering albedo (SSA), lower real part of complex refractive index (n), and obvious hygroscopic growth due to humid air from the south. During autumn and winter, there was an observable increase in absorption aerosol optical thickness (AAOT) and the imaginary part of complex refraction (k), with high levels of retrieved BC and BrC. However, concentrations of BC showed less dependence on the clusters during the two seasons owing to the widely spread coal heating in north China.

PTHrP and Indian hedgehog control differentiation of growth plate chondrocytes at multiple steps.

PubMed

Kobayashi, Tatsuya; Chung, Ung-Il; Schipani, Ernestina; Starbuck, Michael; Karsenty, Gerard; Katagiri, Takenobu; Goad, Dale L; Lanske, Beate; Kronenberg, Henry M

2002-06-01

In developing murine growth plates, chondrocytes near the articular surface (periarticular chondrocytes) proliferate, differentiate into flat column-forming proliferating cells (columnar chondrocytes), stop dividing and finally differentiate into hypertrophic cells. Indian hedgehog (Ihh), which is predominantly expressed in prehypertrophic cells, stimulates expression of parathyroid hormone (PTH)-related peptide (PTHrP) which negatively regulates terminal chondrocyte differentiation through the PTH/PTHrP receptor (PPR). However, the roles of PTHrP and Ihh in regulating earlier steps in chondrocyte differentiation are unclear. We present novel mouse models with PPR abnormalities that help clarify these roles. In mice with chondrocyte-specific PPR ablation and mice with reduced PPR expression, chondrocyte differentiation was accelerated not only at the terminal step but also at an earlier step: periarticular to columnar differentiation. In these models, upregulation of Ihh action in the periarticular region was also observed. In the third model in which the PPR was disrupted in about 30% of columnar chondrocytes, Ihh action in the periarticular chondrocytes was upregulated because of ectopically differentiated hypertrophic chondrocytes that had lost PPR. Acceleration of periarticular to columnar differentiation was also noted in this mouse, while most of periarticular chondrocytes retained PPR signaling. These data suggest that Ihh positively controls differentiation of periarticular chondrocytes independently of PTHrP. Thus, chondrocyte differentiation is controlled at multiple steps by PTHrP and Ihh through the mutual regulation of their activities.

Effects of aging treatment on the microstructure and superelasticity of columnar-grained Cu71Al18Mn11 shape memory alloy

NASA Astrophysics Data System (ADS)

Liu, Ji-li; Huang, Hai-you; Xie, Jian-xin

2016-10-01

The effect of aging treatment on the superelasticity and martensitic transformation critical stress in columnar-grained Cu71Al18Mn11 shape memory alloy (SMA) at the temperature ranging from 250°C to 400°C was investigated. The microstructure evolution during the aging treatment was characterized by optical microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results show that the plate-like bainite precipitates distribute homogeneously within austenitic grains and at grain boundaries. The volume fraction of bainite increases with the increase in aging temperature and aging time, which substantially improves the martensitic transformation critical stress of the alloy, whereas the bainite only slightly affects the superelasticity. This behavior is attributed to a coherent relationship between the bainite and the austenite, as well as to the bainite and the martensite exhibiting the same crystal structure. The variations of the martensitic transformation critical stress and the superelasticity of columnar-grained Cu71Al18Mn11 SMA with aging temperature and aging time are described by the Austin-Rickett equation, where the activation energy of bainite precipitation is 77.2 kJ·mol-1. Finally, a columnar-grained Cu71Al18Mn11 SMA with both excellent superelasticity (5%-9%) and high martensitic transformation critical stress (443-677 MPa) is obtained through the application of the appropriate aging treatments.

Scales of columnar jointing in igneous rocks: field measurements and controlling factors

NASA Astrophysics Data System (ADS)

Hetényi, György; Taisne, Benoît; Garel, Fanny; Médard, Étienne; Bosshard, Sonja; Mattsson, Hannes B.

2012-03-01

Columnar jointing is a common feature of solidified lavas, sills and dikes, but the factors controlling the characteristic stoutness of columns remain debated, and quantitative field observations are few in number. In this paper, we provide quantitative measurements on sizing of columnar joint sets and our assessment of the principal factors controlling it. We focus on (1) chemistry, as it is the major determinant of the physical (mechanical and thermal) properties of the lava, and (2) geology, as it influences the style of emplacement and lava geometry, setting boundary conditions for the cooling process and the rate of heat loss. In our analysis, we cover lavas with a broad range of chemical compositions (from basanite to phonolite, for six of which we provide new geochemical analyses) and of geological settings. Our field measurements cover 50 columnar jointing sites in three countries. We provide reliable, manually digitized data on the size of individual columns and focus the mathematical analysis on their geometry (23,889 data on side length, of which 17,312 are from full column sections and 3,033 data on cross-sectional area and order of polygonality). The geometrical observations show that the variation in characteristic size of columns between different sites exceeds one order of magnitude (side length ranging from 8 to 338 cm) and that the column-bounding polygons' average order is less than 6. The network of fractures is found to be longer than required by a minimum-energy hexagonal configuration, indicating a non-equilibrium, geologically quick process. In terms of the development and characteristic sizing of columnar joint sets, our observations suggest that columns are the result of an interplay between the geological setting of emplacement and magma chemistry. When the geological setting constrains the geometry of the emplaced body, it exerts a stronger control on characteristic column stoutness. At unconstrained geometries (e.g. unconfined lava flows), chemistry plays the major role, resulting in stouter columns in felsic lavas and slenderer columns in mafic lavas.

Structure elucidation of nigricanoside A through enantioselective total synthesis† †Electronic supplementary information (ESI) available: Complete experimental details and characterization data. See DOI: 10.1039/c5sc00281h Click here for additional data file.

PubMed Central

Chen, Jie; Koswatta, Panduka; DeBergh, J. Robb; Fu, Peng; Pan, Ende

2015-01-01

Nigricanoside A was isolated from green alga, and its dimethyl ester was found to display potent cytotoxicity. Its scarcity prevented a full structure elucidation, leaving total synthesis as the only means to determine its relative and absolute stereochemistry and to explore its biological activity. Here we assign the stereochemistry of the natural product through enantioselective total synthesis and provide initial studies of its cytotoxicity. PMID:26877863

Hybrid organic-inorganic system for producing biofuels

DOEpatents

Yeh, Yi-Chun; Singer, Steven W.; Chhabra, Swapnil R.; Beller, Harry R.; Mueller, Jana

2017-10-03

The present invention provides for a system for converting CO.sub.2 and H.sub.2 to one or more biologically derived compounds. In some embodiments, the system comprises a host cell comprising one or more nucleic acids encoding genes for a recombinant surface display protein which is capable of tethering an electrocatalyst molecule, such as a cobalt(II) complex supported by tetradentate polypyridyl ligand 2-bis(2-pyridyl)(methoxy)methyl-6-pyridylpyridine (PY4), and enzymes for synthesizing a biologically derived compound, such as an alkane, alcohol, fatty acid, ester, or isoprenoid.

A ring to rule them all: a cyclic ketene acetal comonomer controls the nitroxide-mediated polymerization of methacrylates and confers tunable degradability.

PubMed

Delplace, Vianney; Guégain, Elise; Harrisson, Simon; Gigmes, Didier; Guillaneuf, Yohann; Nicolas, Julien

2015-08-18

2-Methylene-4-phenyl-1,3-dioxolane (MPDL) was successfully used as a controlling comonomer in NMP with oligo(ethylene glycol) methyl ether methacrylate (MeOEGMA) to prepare well-defined and degradable PEG-based P(MeOEGMA-co-MPDL) copolymers. The level of ester group incorporation is controlled, leading to reductions in molecular weight of up to 95% on hydrolysis. Neither the polymer nor its degradation products displayed cytoxicity. The method was also successfully applied to methyl methacrylate.

Architecture of Columnar Nacre, and Implications for Its Formation Mechanism

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

Metzler, Rebecca A.; Olabisi, Ronke M.; Coppersmith, Susan N.

2007-06-29

We analyze the structure of Haliotis rufescens nacre, or mother-of-pearl, using synchrotron spectromicroscopy and x-ray absorption near-edge structure spectroscopy. We observe imaging contrast between adjacent individual nacre tablets, arising because different tablets have different crystal orientations with respect to the radiation's polarization vector. Comparing previous data and our new data with models for columnar nacre growth, we find the data are most consistent with a model in which nacre tablets are nucleated by randomly distributed sites in the organic matrix layers.

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

Ronchi, C.; Sari, C.

Lenticular pore migration rates in oxide nuclear fuels were measured in out-of-pile heating experiments. It is deduced that those pores which are in part responsible for the formation of columnar grains, are only produced in the absence of relevant amourts of filling gas. Specimens containing important concentrations of He, produced by Pu alpha decay, show columnar grain restructuring by grain boundary migration. Some consequences are drawn concerning the possible role played by lenticular pores in the mechanisms of fission gas release from nuclear fuels. (5 figures) (auth)

Enzymatically and reductively degradable α-amino acid-based poly(ester amide)s: synthesis, cell compatibility, and intracellular anticancer drug delivery.

PubMed

Sun, Huanli; Cheng, Ru; Deng, Chao; Meng, Fenghua; Dias, Aylvin A; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

2015-02-09

A novel and versatile family of enzymatically and reductively degradable α-amino acid-based poly(ester amide)s (SS-PEAs) were developed from solution polycondensation of disulfide-containing di-p-toluenesulfonic acid salts of bis-l-phenylalanine diesters (SS-Phe-2TsOH) with di-p-nitrophenyl adipate (NA) in N,N-dimethylformamide (DMF). SS-PEAs with Mn ranging from 16.6 to 23.6 kg/mol were obtained, depending on NA/SS-Phe-2TsOH molar ratios. The chemical structures of SS-PEAs were confirmed by (1)H NMR and FTIR spectra. Thermal analyses showed that the obtained SS-PEAs were amorphous with a glass transition temperature (Tg) in the range of 35.2-39.5 °C. The in vitro degradation studies of SS-PEA films revealed that SS-PEAs underwent surface erosion in the presence of 0.1 mg/mL α-chymotrypsin and bulk degradation under a reductive environment containing 10 mM dithiothreitol (DTT). The preliminary cell culture studies displayed that SS-PEA films could well support adhesion and proliferation of L929 fibroblast cells, indicating that SS-PEAs have excellent cell compatibility. The nanoparticles prepared from SS-PEA with PVA as a surfactant had an average size of 167 nm in phosphate buffer (PB, 10 mM, pH 7.4). SS-PEA nanoparticles while stable under physiological environment undergo rapid disintegration under an enzymatic or reductive condition. The in vitro drug release studies showed that DOX release was accelerated in the presence of 0.1 mg/mL α-chymotrypsin or 10 mM DTT. Confocal microscopy observation displayed that SS-PEA nanoparticles effectively transported DOX into both drug-sensitive and -resistant MCF-7 cells. MTT assays revealed that DOX-loaded SS-PEA nanoparticles had a high antitumor activity approaching that of free DOX in drug-sensitive MCF-7 cells, while more than 10 times higher than free DOX in drug-resistant MCF-7/ADR cells. These enzymatically and reductively degradable α-amino acid-based poly(ester amide)s have provided an appealing platform for biomedical technology in particular controlled drug delivery applications.

A New Columnar CsI(Tl) Scintillator for iQID detectors

PubMed Central

Han, Ling; Miller, Brian W.; Barber, H. Bradford; Nagarkar, Vivek V.; Furenlid, Lars R.

2015-01-01

A 1650 μm thick columnar CsI(Tl) scintillator for upgrading iQID detectors, which is a high-resolution photon-counting gamma-ray and x-ray detector recently developed at the Center for Gamma-Ray Imaging (CGRI), has been studied in terms of sensitivity, spatial resolution and depth-of-interaction effects. To facilitate these studies, a new frame-parsing algorithm for processing raw event data is also proposed that has more degrees of freedom in data processing and can discriminate against a special kind of noise present in some low-cost intensifiers. The results show that in comparison with a 450 μm-thickness columnar CsI(Tl) scintillator, the 1650 μm thick CsI(Tl) scintillator provides more than twice the sensitivity at the expense of some spatial resolution degradation. The depth-of-interaction study also shows that event size and amplitude vary with scintillator thickness, which can assist in future detector simulations and 3D-interaction-position estimation. PMID:26146444

A New Columnar CsI(Tl) Scintillator for iQID detectors.

PubMed

Han, Ling; Miller, Brian W; Barber, H Bradford; Nagarkar, Vivek V; Furenlid, Lars R

2014-09-12

A 1650 μm thick columnar CsI(Tl) scintillator for upgrading iQID detectors, which is a high-resolution photon-counting gamma-ray and x-ray detector recently developed at the Center for Gamma-Ray Imaging (CGRI), has been studied in terms of sensitivity, spatial resolution and depth-of-interaction effects. To facilitate these studies, a new frame-parsing algorithm for processing raw event data is also proposed that has more degrees of freedom in data processing and can discriminate against a special kind of noise present in some low-cost intensifiers. The results show that in comparison with a 450 μm-thickness columnar CsI(Tl) scintillator, the 1650 μm thick CsI(Tl) scintillator provides more than twice the sensitivity at the expense of some spatial resolution degradation. The depth-of-interaction study also shows that event size and amplitude vary with scintillator thickness, which can assist in future detector simulations and 3D-interaction-position estimation.

Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions

NASA Technical Reports Server (NTRS)

Gandin, Charles-Andre; Ratke, Lorenz

2008-01-01

The Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MSL-CETSOL and MICAST) are two investigations which supports research into metallurgical solidification, semiconductor crystal growth (Bridgman and zone melting), and measurement of thermo-physical properties of materials. This is a cooperative investigation with the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) for accommodation and operation aboard the International Space Station (ISS). Research Summary: Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) are two complementary investigations which will examine different growth patterns and evolution of microstructures during crystallization of metallic alloys in microgravity. The aim of these experiments is to deepen the quantitative understanding of the physical principles that govern solidification processes in cast alloys by directional solidification.

Fabrication of field-effect transistor utilizing oriented thin film of octahexyl-substituted phthalocyanine and its electrical anisotropy based on columnar structure

NASA Astrophysics Data System (ADS)

Ohmori, Masashi; Nakatani, Mitsuhiro; Kajii, Hirotake; Miyamoto, Ayano; Yoneya, Makoto; Fujii, Akihiko; Ozaki, Masanori

2018-03-01

Field-effect transistors with molecularly oriented thin films of metal-free non-peripherally octahexyl-substituted phthalocyanine (C6PcH2), which characteristically form a columnar structure, have been fabricated, and the electrical anisotropy of C6PcH2 has been investigated. The molecularly oriented thin films of C6PcH2 were prepared by the bar-coating technique, and the uniform orientation in a large area and the surface roughness at a molecular level were observed by polarized spectroscopy and atomic force microscopy, respectively. The field effect mobilities parallel and perpendicular to the column axis of C6PcH2 were estimated to be (1.54 ± 0.24) × 10-2 and (2.10 ± 0.23) × 10-3 cm2 V-1 s-1, respectively. The electrical anisotropy based on the columnar structure has been discussed by taking the simulated results obtained by density functional theory calculation into consideration.

A new spectroscopic imager for X-rays from 0.5 keV to 150 keV combining a pnCCD and a columnar CsI(Tl) scintillator

NASA Astrophysics Data System (ADS)

Schlosser, D. M.; Hartmann, R.; Kalok, D.; Bechteler, A.; Abboud, A.; Shokr, M.; Çonka, T.; Pietsch, U.; Strüder, L.

2017-04-01

By combining a low noise fully depleted pnCCD detector with a columnar CsI(Tl) scintillator an energy dispersive spatial resolving detector can be realized with a high quantum efficiency in the range from below 0.5 keV to above 150 keV. The used scintillator system increases the pulse height of gamma-rays converted in the CsI(Tl), due to focusing properties of the columnar scintillator structure by reducing the event size in indirect detection mode (conversion in the scintillator). In case of direct detection (conversion in the silicon of the pnCCD) the relative energy resolution is 0.7% at 122 keV (FWHM = 850 eV) and the spatial resolution is less than 75 μm. In case of indirect detection the relative energy resolution, integrated over all event sizes is about 9% at 122 keV with an expected spatial precision of below 75 μm.

Vortex Escape from Columnar Defect in a Current-Loaded Superconductor

NASA Astrophysics Data System (ADS)

Fedirko, V. A.; Kasatkin, A. L.; Polyakov, S. V.

2018-06-01

The problem of Abrikosov vortices depinning from extended linear (columnar) defect in 3D-anisotropic superconductor film under non-uniformly distributed Lorentz force is studied for the case of low temperatures, disregarding thermal activation processes. We treat it as a problem of mechanical behavior of an elastic vortex string settled in a potential well of a linear defect and exerted to Lorentz force action within the screening layer about the London penetration depth near the specimen surface. The stability problem for the vortex pinning state is investigated by means of numerical modeling, and conditions for the instability threshold are obtained as well as the critical current density j_c and its dependence on the film thickness and magnetic field orientation. The instability leading to vortex depinning from extended linear defect first emerges near the surface and then propagates inside the superconductor. This scenario of vortex depinning mechanism at low temperatures is strongly supported by some recent experiments on high-Tc superconductors and other novel superconducting materials, containing columnar defects of various nature.

Comparison of the columnar-thin-film and vacuum-metal-deposition techniques to develop sebaceous fingermarks on nonporous substrates.

PubMed

Williams, Stephanie F; Pulsifer, Drew P; Shaler, Robert C; Ramotowski, Robert S; Brazelle, Shelly; Lakhtakia, Akhlesh

2015-03-01

Both the columnar-thin-film (CTF) and the vacuum-metal-deposition (VMD) techniques for visualizing sebaceous fingermarks require the deposition of a material thereon in a vacuum chamber. Despite that similarity, there are many differences between the two techniques. The film deposited with the CTF technique has a columnar morphology, but the film deposited with the VMD technique comprises discrete islands. A split-print methodology on a variety of fingermarked substrates was used to determine that the CTF technique is superior for developing fingermarks on clear sandwich bags and partial bloody fingermarks on stainless steel. Both techniques are similar in their ability to develop fingermarks on glass but the CTF technique yields higher contrast. The VMD technique is superior for developing fingermarks on white grocery bags and the smooth side of Gloss Finish Scotch Multitask(™) tape. Neither technique worked well for fingermarks on black garbage bags. © 2014 American Academy of Forensic Sciences.

Structural investigation of spherical hollow excipient Mannit Q by X-ray microtomography.

PubMed

Kajihara, Ryusuke; Noguchi, Shuji; Iwao, Yasunori; Yasuda, Yuki; Segawa, Megumi; Itai, Shigeru

2015-11-10

The structure of Mannit Q particles, an excipient made by spray-drying a d-mannitol solution, and Mannit Q tablets were investigated by synchrotron X-ray microtomography. The Mannit Q particles had a spherical shape with a hollow core. The shells of the particles consisted of fine needle-shaped crystals, and columnar crystals were present in the hollows. These structural features suggested the following formation mechanism for the hollow particles:during the spray-drying process, the solvent rapidly evaporated from the droplet surface, resulting in the formation of shells made of fine needle-shaped crystals.Solvent remaining inside the shells then evaporated slowly and larger columnar crystals grew as the hollows formed. Although most of the Mannit Q particles were crushed on tableting, some of the particles retained their hollow structures, probably because the columnar crystals inside the hollows functioned as props. This demonstrated that the tablets with porous void spaces may be readily manufactured using Mannit Q. Copyright © 2015 Elsevier B.V. All rights reserved.

Estimation of columnar concentrations of absorbing and scattering fine mode aerosol components using AERONET data

NASA Astrophysics Data System (ADS)

Choi, Yongjoo; Ghim, Young Sung

2016-11-01

Columnar concentrations of absorbing and scattering components of fine mode aerosols were estimated using Aerosol Robotic Network (AERONET) data for a site downwind of Seoul. The study period was between March 2012 and April 2013 including the period of the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-Asia campaign in March to May 2012. The Maxwell Garnett mixing rule was assumed for insoluble components embedded in a host solution, while the volume average mixing rule was assumed for the aqueous solution of soluble components. During the DRAGON-Asia campaign the surface concentrations of major components of fine particles were measured. The columnar mass fractions of black carbon (BC), organic carbon (OC), mineral dust (MD), and ammonium sulfate (AS) were 1.5, 5.9, 6.6, and 52%, respectively, which were comparable to the mass fractions measured at the surface for BC, OC, and secondary inorganic aerosols at 2.3, 18, and 55%. The vertical distributions of BC and AS were investigated by employing the concept of a column height. While the column height for BC was similar to the planetary boundary layer (PBL) height, that for AS was 4.4 times higher than the PBL height and increased with air temperature from March to May. The monthly variations of the columnar mass concentrations during the study period were generally well explained in term of meteorology and emission characteristics. However, certain variations of MD were different from those typically observed primarily because only fine mode aerosols were considered.

Efficacy of oxytetracycline hydrochloride bath immersion to control external columnaris disease on walleye and channel catfish fingerlings

USGS Publications Warehouse

Rach, J.J.; Johnson, Aaron H.; Rudacille, J.B.; Schleis, S.M.

2008-01-01

The efficacy of oxytetracycline hydrochloride (OTC-HCl) in controlling external columnaris disease caused by Flavobacterium columnare on fingerling walleyes Sander vitreus and channel catfish Ictalurus punctatus was evaluated in two on-site hatchery trials. Microscopic examination of skin scrapings before treatment confirmed the presence of bacteria with characteristics indicative of F. columnare.in separate trials, walleyes (4.4 g) and channel catfish (1.5 g) were exposed to 60-min static bath treatments of OTC-HCl at 0, 10, and 20 mg/L (walleyes) or 0, 10, 20, and 40 mg/L (channel catfish) on three consecutive days. Each treatment regimen was tested in triplicate, and each replicate contained either 30 walleyes or 55 channel catfish. Posttreatment presumptive disease diagnosis indicated that F. columnare was the disease agent causing the mortality in both species of fish. Walleye survival at 10 d posttreatment was greater in the 10- and 20-mg/L treatment groups than in the control group; however, only the 10-mg/L treatment significantly (P < 0.05) increased walleye survival in comparison with controls. In the channel catfish trial, survival at 10 d posttreatment was significantly (P < 0.05) greater for all OTC-HCl treatment groups relative to controls. Results from these trials indicated that OTC-HCl treatments effectively reduced mortality in walleyes (10 mg/L only) and channel catfish infected with F. columnare. ?? Copyright by the American Fisheries Society 2008.

Intensive fish farming and the evolution of pathogen virulence: the case of columnaris disease in Finland

PubMed Central

Pulkkinen, K.; Suomalainen, L.-R.; Read, A. F.; Ebert, D.; Rintamäki, P.; Valtonen, E. T.

2010-01-01

Ecological changes affect pathogen epidemiology and evolution and may trigger the emergence of novel diseases. Aquaculture radically alters the ecology of fish and their pathogens. Here we show an increase in the occurrence of the bacterial fish disease Flavobacterium columnare in salmon fingerlings at a fish farm in northern Finland over 23 years. We hypothesize that this emergence was owing to evolutionary changes in bacterial virulence. We base this argument on several observations. First, the emergence was associated with increased severity of symptoms. Second, F. columnare strains vary in virulence, with more lethal strains inducing more severe symptoms prior to death. Third, more virulent strains have greater infectivity, higher tissue-degrading capacity and higher growth rates. Fourth, pathogen strains co-occur, so that strains compete. Fifth, F. columnare can transmit efficiently from dead fish, and maintain infectivity in sterilized water for months, strongly reducing the fitness cost of host death likely experienced by the pathogen in nature. Moreover, this saprophytic infectiousness means that chemotherapy strongly select for strains that rapidly kill their hosts: dead fish remain infectious; treated fish do not. Finally, high stocking densities of homogeneous subsets of fish greatly enhance transmission opportunities. We suggest that fish farms provide an environment that promotes the circulation of more virulent strains of F. columnare. This effect is intensified by the recent increases in summer water temperature. More generally, we predict that intensive fish farming will lead to the evolution of more virulent pathogens. PMID:19864284

Anomalous columnar order of charged colloidal platelets

NASA Astrophysics Data System (ADS)

Morales-Anda, L.; Wensink, H. H.; Galindo, A.; Gil-Villegas, A.

2012-01-01

Monte Carlo computer simulations are carried out for a model system of like-charged colloidal platelets in the isothermal-isobaric ensemble (NpT). The aim is to elucidate the role of electrostatic interactions on the structure of synthetic clay systems at high particle densities. Short-range repulsions between particles are described by a suitable hard-core model representing a discotic particle. This potential is supplemented with an electrostatic potential based on a Yukawa model for the screened Coulombic potential between infinitely thin disklike macro-ions. The particle aspect-ratio and electrostatic parameters were chosen to mimic an aqueous dispersion of thin, like-charged, rigid colloidal platelets at finite salt concentration. An examination of the fluid phase diagram reveals a marked shift in the isotropic-nematic transition compared to the hard cut-sphere reference system. Several statistical functions, such as the pair correlation function for the center-of-mass coordinates and structure factor, are obtained to characterize the structural organization of the platelets phases. At low salinity and high osmotic pressure we observe anomalous hexagonal columnar structures characterized by interpenetrating columns with a typical intercolumnar distance corresponding to about half of that of a regular columnar phase. Increasing the ionic strength leads to the formation of glassy, disordered structures consisting of compact clusters of platelets stacked into finite-sized columns. These so-called "nematic columnar" structures have been recently observed in systems of charge-stabilized gibbsite platelets. Our findings are corroborated by an analysis of the static structure factor from a simple density functional theory.

Nutrient limitation leads to penetrative growth into agar and affects aroma formation in Pichia fabianii, P. kudriavzevii and Saccharomyces cerevisiae.

PubMed

van Rijswijck, Irma M H; Dijksterhuis, Jan; Wolkers-Rooijackers, Judith C M; Abee, Tjakko; Smid, Eddy J

2015-01-01

Among fermentative yeast species, Saccharomyces cerevisiae is most frequently used as a model organism, although other yeast species may have special features that make them interesting candidates to apply in food-fermentation processes. In this study, we used three yeast species isolated from fermented masau (Ziziphus mauritiana) fruit, S. cerevisiae 131, Pichia fabianii 65 and Pichia kudriavzevii 129, and determined the impact of nitrogen and/or glucose limitation on surface growth mode and the production of volatile organic compounds (VOCs). All three species displayed significant changes in growth mode in all nutrient-limited conditions, signified by the formation of metafilaments or pseudohyphae. The timing of the transition was found to be species-specific. Transition in growth mode is suggested to be linked to the production of certain fusel alcohols, such as phenylethyl alcohol, which serve as quorum-sensing molecules. Interestingly, we did not observe concomitant increased production of phenylethyl alcohol and filamentous growth. Notably, a broader range of esters was found only for the Pichia spp. grown on nitrogen-limited agar for 21 days compared to nutrient-rich agar, and when grown on glucose- and glucose- plus nitrogen-limited agar. Our data suggest that for the Pichia spp., the formation of esters may play an important role in the switch in growth mode upon nitrogen limitation. Further biological or ecological implications of ester formation are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

Design and Synthesis of Novel Discotic Liquid Crystals

NASA Astrophysics Data System (ADS)

Kayal, Himadri Sekhar

Columnar mesophases of discotic liquid crystals (DLCs) have attracted much attention as organic semiconductors and have been tested as active materials in light-emitting diodes, photovoltaic solar cells, and field-effect transistors. However, devices based on DLCs have shown lower performance than devices based on polymeric and small molecule glass semiconductors, despite their superior charge conducting and advantages self-organizing properties. Most DLCs also require relatively complex processing conditions for the preparation of electronic devices, which is another significant disadvantage. Consequently, new types of DLCs are sought-after to overcome these limitations and described in this thesis are new types of discotic materials and their synthesis. Chapters 2 and 3 describe star-shaped discotic molecules for donor-acceptor columnar structures and as novel flexible core discotic molecules. Presented are the first examples of star-shaped heptamers of donor and acceptor discotic molecules which have six hexaalkoxy triphenylene ligands and a hexaazatriphenylene hexacarboxylate core or a hexaazatriphenylene hexaamide core. The hexaazatriphenylene cores were chosen because of their electron deficient character while the hexaalkoxy triphenylenes are known to be electron rich. Envisioned is the formation of super-columns in which the heptamers stack on top of each other and generate a material with electron acceptor and electron donor channels separated by aliphatic chains. This is an important difference to previously reported donor-acceptor star-shaped structures that were connected via conjugated linkers and do not form separate columnar stacks. Star-shaped DLCs based on small aromatic groups linked together by short flexible spacers may represent a novel type of discotic core structure that does not require peripheral flexible chains. Softening of the core by the spacer group is expected to sufficiently lower melting points and not interfere with the columnar stacking as long as a disc-shaped structure can be adopted. Presented here are synthetic approaches towards novel hexa(thiophen-2-yl)alkyl)benzene derivatives as star-shaped hetero-heptamer discotic cores. New ionic and polymerizable discotic liquid crystals based on the commercial dye tetraazaporphyrin are presented in Chapters 4 and 5. Both areas have been given little attention despite their importance for the preparation of stable films for devices. Tetraazaporphyrins containing azide and acetylene groups at the end of aliphatic spacers have been prepared and cross-linked by cycloaddition (click chemistry). Some derivatives form columnar mesophases and could be thermally cross-linked in their columnar mesophase and their copper catalyzed cross-linking in Langmuir and Langmuir-Blodgett layers was also successful.

Biochemical analysis of a papain-like protease isolated from the latex of Asclepias curassavica L.

PubMed

Liggieri, Constanza; Obregon, Walter; Trejo, Sebastian; Priolo, Nora

2009-02-01

Most of the species belonging to Asclepiadaceae family usually secrete an endogenous milk-like fluid in a network of laticifer cells in which sub-cellular organelles intensively synthesize proteins and secondary metabolites. A new papain-like endopeptidase (asclepain c-II) has been isolated and characterized from the latex extracted from petioles of Asclepias curassavica L. (Asclepiadaceae). Asclepain c-II was the minor proteolytic component in the latex, but showed higher specific activity than asclepain c-I, the main active fraction previously studied. Both enzymes displayed quite distinct biochemical characteristics, confirming that they are different enzymes. Crude extract was purified by cation exchange chromatography (FPLC). Two active fractions, homogeneous by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and mass spectrometry, were isolated. Asclepain c-II displayed a molecular mass of 23,590 Da, a pI higher than 9.3, maximum proteolytic activity at pH 9.4-10.2, and showed poor thermostability. The activity of asclepain c-II is inhibited by cysteine proteases inhibitors like E-64, but not by any other protease inhibitors such as 1,10-phenantroline, phenylmethanesulfonyl fluoride, and pepstatine. The Nterminal sequence (LPSFVDWRQKGVVFPIRNQGQCGSCWTFSA) showed a high similarity with those of other plant cysteine proteinases. When assayed on N-alpha-CBZ-amino acid-p-nitrophenyl esters, the enzyme exhibited higher preference for the glutamine derivative. Determinations of kinetic parameters were performed with N-alpha-CBZ-L-Gln-p-nitrophenyl ester as substrate: K(m)=0.1634 mM, k(cat)=121.48 s(-1), and k(cat)/K(m)=7.4 x 10(5) s(-1)/mM.

Synthesis and Evaluation of Ester Derivatives of 10-Hydroxycanthin-6-one as Potential Antimicrobial Agents.

PubMed

Zhao, Fei; Dai, Jiang-Kun; Liu, Dan; Wang, Shi-Jun; Wang, Jun-Ru

2016-03-21

As part of our continuing research on canthin-6-one antimicrobial agents, a new series of ester derivatives of 10-hydroxycanthin-6-one were synthesized using a simple and effective synthetic route. The structure of each compound was characterized by NMR, ESI-MS, FT-IR, UV, and elemental analysis. The antimicrobial activity of these compounds against three phytopathogenic fungi (Alternaria solani, Fusarium graminearum, and Fusarium solani) and four bacteria (Bacillus cereus, Bacillus subtilis, Ralstonia solanacearum, and Pseudomonas syringae) were evaluated using the mycelium linear growth rate method and micro-broth dilution method, respectively. The structure-activity relationship is discussed. Of the tested compounds, 4 and 7s displayed significant antifungal activity against F. graminearum, with inhibition rates of 100% at a concentration of 50 μg/mL. Compounds 5, 7s, and 7t showed the best inhibitory activity against all the tested bacteria, with minimum inhibitory concentrations (MICs) between 3.91 and 31.25 μg/mL. Thus, 7s emerged as a promising lead compound for the development of novel canthine-6-one antimicrobial agents.

Functional attributes of a new molecule-2-hydroxymethyl-benzoic acid 2'-hydroxy-tetradecyl ester isolated from Talaromyces purpureogenus CFRM02.

PubMed

Pandit, Saritha Gopal; Puttananjaih, Mohankumari H; Harohally, Nanishankar V; Dhale, Mohan Appasaheb

2018-07-30

An account of antioxidant and antimicrobial characteristics displayed by ethyl acetate extract of Talaromyces purpureogenus CFRM-02 cultivated by submerged fermentation on bengal gram husk (BegH) led to the isolation of a new molecule, which was purified via silica gel column chromatography. The TLC and HPLC data revealed the purity of the isolated compound. By employing an array of spectroscopic techniques, structural elucidation was accomplished, and the molecule was identified as 2-hydroxymethyl-benzoic acid 2'-hydroxy-tetradecyl ester and was also designated with a familiar name pentalsamonin. The pentalsamonin molecule scavenged DPPH (24%), H 2 O 2 (64%), superoxide anion (58%) with a reducing power (0.989 AU) at the given concentration. The MIC and MBC of pentalsamonin against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae are in the range 62.5-125 and 125-250 µg/ml, respectively. The antioxidant and antibacterial functional attributes of pentalsamonin suggest useful applications in food and nutraceuticals. Copyright © 2018 Elsevier Ltd. All rights reserved.

S-alkynyl esters of phosphorus thioacids as inhibitors of cholinesterases and as promising physiologically active compounds

NASA Astrophysics Data System (ADS)

Brestkin, A. P.; Vikhreva, L. A.; Godovikov, Nikolai N.; Zhukovskii, Yu G.; Kabachnik, Martin I.; Moralev, S. N.; Rosengart, V. I.; Sherstobitov, O. E.

1991-08-01

Data are given in the review on the anticholinesterase activity of 58 specially synthesised esters of phosphorus thioacids containing an acetylenic bond in the thioester group. It was established that compounds containing an acetylenic group in the β and especially in the α position of the thioester residue display an inhibitory action many times greater than that of their saturated analogues. A phosphorylated enzyme is formed by the reaction of the acetylenic organophosphorus inhibitors (OPIs) with the enzymes as in the case of reaction with the saturated analogues. It was shown that the acetylenic organophosphorus inhibitors possess high biological activity both for mammals and for arthropods. On replacing the phosphoryl oxygen (P=O) by sulphur (P=S) the toxicity of the acetylenic organophosphorus inhibitors for mammals was sharply reduced but was little changed for arthropods. This raises the possibility of obtaining highly selective insecto-acaricides. The mechanism of the antienzymic action of the acetylenic OPIs and the mechanism of detoxication of diethyl S-hexynyl dithiophosphate are considered. The bibliography includes 44 references.

Dietary intake of plant sterols stably increases plant sterol levels in the murine brain.

PubMed

Vanmierlo, Tim; Weingärtner, Oliver; van der Pol, Susanne; Husche, Constanze; Kerksiek, Anja; Friedrichs, Silvia; Sijbrands, Eric; Steinbusch, Harry; Grimm, Marcus; Hartmann, Tobias; Laufs, Ulrich; Böhm, Michael; de Vries, Helga E; Mulder, Monique; Lütjohann, Dieter

2012-04-01

Plant sterols such as sitosterol and campesterol are frequently administered as cholesterol-lowering supplements in food. Recently, it has been shown in mice that, in contrast to the structurally related cholesterol, circulating plant sterols can enter the brain. We questioned whether the accumulation of plant sterols in murine brain is reversible. After being fed a plant sterol ester-enriched diet for 6 weeks, C57BL/6NCrl mice displayed significantly increased concentrations of plant sterols in serum, liver, and brain by 2- to 3-fold. Blocking intestinal sterol uptake for the next 6 months while feeding the mice with a plant stanol ester-enriched diet resulted in strongly decreased plant sterol levels in serum and liver, without affecting brain plant sterol levels. Relative to plasma concentrations, brain levels of campesterol were higher than sitosterol, suggesting that campesterol traverses the blood-brain barrier more efficiently. In vitro experiments with brain endothelial cell cultures showed that campesterol crossed the blood-brain barrier more efficiently than sitosterol. We conclude that, over a 6-month period, plant sterol accumulation in murine brain is virtually irreversible.

Analytical ultrasonics for structural materials

NASA Technical Reports Server (NTRS)

Kupperman, D. S.

1986-01-01

The application of ultrasonic velocity and attenuation measurements to characterize the microstructure of structural materials is discussed. Velocity measurements in cast stainless steel are correlated with microstructural variations ranging from equiaxed (elastically isotropic) to columnar (elastically anisotropic) grain structure. The effect of the anisotropic grain structure on the deviation of ultrasonic waves in cast stainless steel is also reported. Field-implementable techniques for distinguishing equiaxed from columnar grain structures in cast strainless steel structural members are presented. The application of ultrasonic velocity measurements to characterize structural ceramics in the green state is also discussed.

VHF/UHF technique for the determination of the columnar electron contents of the plasmasphere and of the protonosphere using geostationary satellite transmission: Observations during magnetic storms

NASA Technical Reports Server (NTRS)

Almeida, O. G.

1972-01-01

Measurements of the total electron content of the plasmasphere up to geostationary heights were made using the beacon transmitters aboard the satellite ATS-3. The technique employed is a combination of the phase-path length difference and the Faraday rotation angle methods. Such a combination permits very accurate determination of the integration constant necessary to convert phase-path length difference data into information about the absolute value of the columnar content.

Fluorescent lamp unit with magnetic field generating means

DOEpatents

Grossman, Mark W.; George, William A.

1989-01-01

A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope.

Fluorescent lamp unit with magnetic field generating means

DOEpatents

Grossman, M.W.; George, W.A.

1989-08-08

A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope. 4 figs.

High rectification in organic diodes based on liquid crystalline phthalocyanines.

PubMed

Apostol, Petru; Eccher, Juliana; Dotto, Marta Elisa Rosso; Costa, Cassiano Batesttin; Cazati, Thiago; Hillard, Elizabeth A; Bock, Harald; Bechtold, Ivan H

2015-12-28

The optical and electrical properties of mesogenic metal-free and metalated phthalocyanines (PCs) with a moderately sized and regioregular alkyl periphery were investigated. In solution, the individualized molecules show fluorescence lifetimes of 4-6 ns in THF. When deposited as solid thin films the materials exhibit significantly shorter fluorescence lifetimes with bi-exponential decay (1.4-1.8 ns; 0.2-0.4 ns) that testify to the formation of aggregates viaπ-π intermolecular interactions. In diode structures, their pronounced columnar order outbalances the unfavorable planar alignment and leads to excellent rectification behavior. Field-dependent charge carrier mobilities are obtained from the J-V curves in the trap-limited space-charge-limited current regime and demonstrate that the metalated PCs display an improved electrical response with respect to the metal-free homologue. The excited-state lifetime characterization suggest that the π-π intermolecular interactions are stronger for the metal-free PC, confirming that the metallic centre plays an important role in the charge transport inside these materials.

Porosity and test ultrastructure of costate and non-costate Bulimina species

NASA Astrophysics Data System (ADS)

Grunert, Patrick; Piller, Werner E.

2017-04-01

SEM-based investigations of porosity and test wall ultrastructure of Recent costate and non-costate Bulimina species reveal significant differences in pore diameter, pore density and ultrastructural architecture between these two groups. Costate tests of B. inflata and B. mexicana display low pore density, a large pore diameter, and test walls built by a single type of columnar ultrastructural elements. In contrast, non-costate tests of B. aculeata and B. marginata are characterized by significantly higher pore density, smaller pore diameter, and an additional type of ultrastructural elements formed by oblique, tabular crystallite units which encase the pore channels. We interpret the observed combination of traits in B. aculeata and B. marginata as a set of adaptations to poorly oxygenated, intermediate to deep infaunal microhabitats which they typically occupy today. The evolutionary trend towards increased pore density in this group seemingly involved a major modification of the biomineralisation process resulting in the lining of pore channels with a specific type of ultrastructural element to ensure stability of the densely perforated test.

Ovarian teratoma displaying a wide variety of tissue components in a broiler chicken (Gallus Domesticus): morphological heterogeneity of pluripotential germ cell during tumorigenesis.

PubMed

Ohfuji, S

2016-01-01

Spontaneous ovarian teratoma was found in a seven-week-old female Chunky broiler chicken that was slaughtered for food. On post-mortem inspection, a spherical tumor mass attaching to a juvenile ovary was found in the abdominal cavity. Histopathologically, the tumor was comprised of immature mesenchymal stroma and a variety of mature tissue elements of mesodermal and ectodermal origin. In addition, there were multiple indistinguishable tissue elements, which showed no malignant cytological features but were unidentifiable as to corresponding embryological layer of origin. These heterogeneous teratoma tissues consisted of a variety of glandular, cystic, duct-like, and tubular structures, some of which exhibited a lining by a mixture of both keratinizing/non-keratinizing stratified squamous epithelial cells and cuboidal/columnar epithelial cells. The ovarian tetatoma was considered a benign and congenital one. The highly diverse differentiation of the teratoma might have manifested a morphological aspect of intrinsic character of the pluripotential germ cells during tumorigenesis.

Rab11 is phosphorylated by classical and novel protein kinase C isoenzymes upon sustained phorbol ester activation.

PubMed

Pavarotti, Martín; Capmany, Anahí; Vitale, Nicolas; Colombo, María Isabel; Damiani, María Teresa

2012-02-01

Rab11 is a small GTPase that controls diverse intracellular trafficking pathways. However, the molecular machinery that regulates the participation of Rab11 in those different transport events is poorly understood. In resting cells, Rab11 localizes at the endocytic recycling compartment (ERC), whereas the different protein kinase C (PKC) isoforms display a cytosolic distribution. Sustained phorbol ester stimulation induces the translocation of the classical PKCα and PKCβII isoenzymes to the ERC enriched in Rab11, and results in transferrin recycling inhibition. In contrast, novel PKCε and atypical PKCζ isoenzymes neither redistribute to the perinucleus nor modify transferrin recycling transport after phorbol ester stimulation. Although several Rabs have been shown to be phosphorylated, there is to date no evidence indicating Rab11 as a kinase substrate. In this report, we show that Rab11 appears phosphorylated in vivo in phorbol ester-stimulated cells. A bioinformatic analysis of Rab11 allowed us to identify several high-probability Ser/Thr kinase phosphorylation sites. Our results demonstrate that classical PKC (PKCα and PKCβII but not PKCβI) directly phosphorylate Rab11 in vitro. In addition, novel PKCε and PKCη but not PKCδ isoenzymes also phosphorylate Rab11. Mass spectrometry analysis revealed that Ser 177 is the Rab11 residue to be phosphorylated in vitro by either PKCβII or PKCε. In agreement, the phosphomimetic mutant, Rab11 S177D, retains transferrin at the ERC in the absence of phorbol-12-myristate-13-acetate stimulus. This report shows for the first time that Rab11 is differentially phosphorylated by distinct PKC isoenzymes and that this post-translational modification might be a regulatory mechanism of intracellular trafficking. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

Transfer of Vitamins E and A from yolk to embryo during development of the king penguin (Aptenodytes patagonicus).

PubMed

Surai, P F; Speake, B K; Decrock, F; Groscolas, R

2001-01-01

Since the yolk lipids of the king penguin (Aptenodytes patagonicus) are rich in n-3 fatty acids, which are potentially susceptible to peroxidative damage, the yolk contents and yolk-to-embryo transfer of antioxidants and lipid-soluble vitamins were investigated under conditions of natural incubation in the wild. The concentration of vitamin E in the unincubated egg was 155 microg/g wet yolk, of which 88% was alpha-tocopherol and the rest was gamma-tocopherol. Vitamin A (2.9 microg/g) was present in the yolk entirely as retinol; no retinyl esters were detected. Throughout the latter half of the incubation period, vitamins E and A were taken up from the yolk into the yolk sac membrane (YSM) and later accumulated in the liver, with vitamin A being transferred in advance of vitamin E. In the YSM, vitamin A was present almost entirely as retinyl ester, indicating that the free retinol of the yolk is rapidly esterified following uptake. Retinyl esters were also the predominant form in the liver. The retinyl esters of the liver and YSM displayed different fatty acid profiles. At hatching, the brain contained relatively little vitamin E (4.7 microg/g) compared to the much higher concentration in the liver (482.9 microg/g) at this stage. Ascorbic acid was not detected in the yolk but was present at a high concentration in the brain at day 27 (404.6 microg/g), decreasing to less than half this value by the time of hatching. This report is the first to delineate the yolk-to-embryo transfer of lipid-soluble vitamins for a free-living avian species. The yolk fatty acids of the king penguin provide an extreme example of potential oxidative susceptibility, forming a basis for comparative studies on embryonic antioxidant requirements among species of birds whose yolk lipids differ in their degree of unsaturation.

Columnar and ground-level aerosol optical properties: sensitivity to the transboundary pollution, daily and weekly patterns, and relationships.

PubMed

Perrone, M R; Romano, S; Orza, J A G

2015-11-01

Columnar and ground-level aerosol optical properties co-located in space and time and retrieved from sun/sky photometer and nephelometer measurements, respectively, have been analyzed to investigate the impact of local and transboundary pollution, to analyze their relationships, and hence to contribute to the aerosol load characterization over the Central Mediterranean. The aerosol optical depth (AOD) at 440 nm, the Ångström exponent (Å) calculated from the AOD at 440 and 675 nm, and the asymmetry parameter (g col ) at 440 nm represent the investigated columnar aerosol parameters. The scattering coefficient (σ p) at 450 nm, the scattering Ångström exponent (å) calculated from σ p at 450 and 635 nm, and the asymmetry parameter (g) at 450 nm are the corresponding ground-level parameters. It is shown that the columnar and ground-level aerosol properties were significantly and similarly affected by the main airflows identified with backtrajectory cluster analysis. The yearly averaged daily evolution of σ p, å, and g was fairly correlated to the one of the AOD, Å, and g col , respectively. These results indicate that the aerosol particles were on average characterized by similar yearly averaged optical properties up to the ground level. In particular, the yearly means of columnar and ground-level Ångström exponents, 1.3 ± 0.4 and 1.1 ± 0.4, respectively, which are close to one, reveal a coarse-mode aerosol contribution in addition to the fine-mode particle contribution up to the ground level. Hourly means, day-by-day, and seasonal daily patterns of ground-level parameters were, however, very weakly correlated with the corresponding columnar parameters. The large impact of the local meteorology on the daily evolution of the ground-level aerosol properties, which makes the impact of long-range transported particles less apparent, was mainly responsible for these last results. It has also been found that columnar Ångström exponents much smaller than one may not be linked to å values smaller than 1. This may occurs when coarse-mode particle plumes, advected at high altitudes, do not penetrate inside the planetary boundary layer. Ångström exponents smaller than 1 are due to a significant contribution of coarse-mode particles as dust particles. Therefore, it is shown that å represents one of the best parameters to infer the contribution of coarse-mode particles at the ground level. The daily evolution of the aerosol properties referring to working days (Monday to Friday) and Sunday and the weekly cycle have suggested that the aerosol source contributions varied during the weekends. In particular, the AOD was characterized by a negative weekly cycle (higher AOD values during the weekend than during the weekdays), the Sunday σ p daily mean was 11 % larger than the Monday value, and å reached the highest value on Sunday. The impact up to the ground level of the weekdays' transboundary pollution, which reaches the monitoring site during the weekends, has likely contributed to these results.

Transesterification of plant oils using Staphylococcus haemolyticus L62 lipase displayed on Escherichia coli cell surface using the OmpA signal peptide and EstAβ8 anchoring motif.

PubMed

Jo, Jin Chul; Kim, Soon-Ja; Kim, Hyung Kwoun

2014-12-01

Staphylococcus haemolyticus L62 (SHL62) lipase was displayed on the outer membrane of Escherichia coli using the OmpA signal peptide and the autotransporter EstAβ8 protein. Localization of SHL62 lipase on the outer membrane of E. coli was confirmed using immunofluorescence microscopy and flow cytometry analysis. Lipase activity of the displayed SHL62 lipase was also measured using spectrophotometry and pH titration. SHL62 lipase activity of whole cells reached 2.0U/ml culture (OD600nm of 10) when it was measured by the p-nitrophenyl caprylate assay after being induced with 1mM IPTG for 24h. The optimum temperature and pH for the lipase was 45°C and 10, respectively. Furthermore, it maintained more than 90% of maximum lipase activity at up to 50°C and in a pH range of 5-9. The hydrolytic activity assay conduted with various substrates confirmed that p-nitrophenyl caprylate and corn oil were preferred substrates among various synthetic and natural substrates, respectively. The displayed SHL62 lipase produced fatty acid esters from various alcohols and plant oils through transesterification. Copyright © 2014 Elsevier Inc. All rights reserved.

Power generating reflective-type liquid crystal displays using a reflective polariser and a polymer solar cell.

PubMed

Ho Huh, Yoon; Park, Byoungchoo

2015-06-23

We herein report the results of a study of a power generating reflective-type liquid crystal display (LCD), composed of a 90° twisted nematic (TN) LC cell attached to the top of a light-absorbing polymer solar cell (PSC), i.e., a Solar-LCD. The PSC consisted of a polymer bulk-heterojunction photovoltaic (PV) layer of poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl] and [6,6]-phenyl C71 butyric acid methyl ester (PCDTBT:PCBM70), and showed a high power conversion efficiency of about 5%. In order to improve the visibility of the Solar-LCD, between the TN-LC and the PV cells we inserted a reflective polariser of a giant birefringent optical (GBO) film. The reflectivity from the Solar-LCD was observed to be considerably increased by more than 13-15% under illumination by visible light. The Solar-LCD also exhibited a significantly improved contrast ratio of more than 17-19. We believe there is a clear case for using such Solar-LCDs in new power-generating reflective-type displays; taken as a whole these results also demonstrate the possibility of their application in a number of energy-harvesting opto-electrical display devices.

Striped Data Server for Scalable Parallel Data Analysis

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

Chang, Jin; Gutsche, Oliver; Mandrichenko, Igor

A columnar data representation is known to be an efficient way for data storage, specifically in cases when the analysis is often done based only on a small fragment of the available data structures. A data representation like Apache Parquet is a step forward from a columnar representation, which splits data horizontally to allow for easy parallelization of data analysis. Based on the general idea of columnar data storage, working on the [LDRD Project], we have developed a striped data representation, which, we believe, is better suited to the needs of High Energy Physics data analysis. A traditional columnar approachmore » allows for efficient data analysis of complex structures. While keeping all the benefits of columnar data representations, the striped mechanism goes further by enabling easy parallelization of computations without requiring special hardware. We will present an implementation and some performance characteristics of such a data representation mechanism using a distributed no-SQL database or a local file system, unified under the same API and data representation model. The representation is efficient and at the same time simple so that it allows for a common data model and APIs for wide range of underlying storage mechanisms such as distributed no-SQL databases and local file systems. Striped storage adopts Numpy arrays as its basic data representation format, which makes it easy and efficient to use in Python applications. The Striped Data Server is a web service, which allows to hide the server implementation details from the end user, easily exposes data to WAN users, and allows to utilize well known and developed data caching solutions to further increase data access efficiency. We are considering the Striped Data Server as the core of an enterprise scale data analysis platform for High Energy Physics and similar areas of data processing. We have been testing this architecture with a 2TB dataset from a CMS dark matter search and plan to expand it to multiple 100 TB or even PB scale. We will present the striped format, Striped Data Server architecture and performance test results.« less

Laminar iridium coating produced by pulse current electrodeposition from chloride molten salt

NASA Astrophysics Data System (ADS)

Zhu, Li'an; Bai, Shuxin; Zhang, Hong; Ye, Yicong

2013-10-01

Due to the unique physical and chemical properties, Iridium (Ir) is one of the most promising oxidation-resistant coatings for refractory materials above 1800 °C in aerospace field. However, the Ir coatings prepared by traditional methods are composed of columnar grains throughout the coating thickness. The columnar structure of the coating is considered to do harm to its oxidation resistance. The laminar Ir coating is expected to have a better high-temperature oxidation resistance than the columnar Ir coating does. The pulse current electrodeposition, with three independent parameters: average current density (Jm), duty cycle (R) and pulse frequency (f), is considered to be a promising method to fabricate layered Ir coating. In this study, laminar Ir coatings were prepared by pulse current electrodeposition in chloride molten salt. The morphology, roughness and texture of the coatings were determined by scanning electron microscope (SEM), profilometer and X-ray diffraction (XRD), respectively. The results showed that the laminar Ir coatings were composed of a nucleation layer with columnar structure and a growth layer with laminar structure. The top surfaces of the laminar Ir coatings consisted of cauliflower-like aggregates containing many fine grains, which were separated by deep grooves. The laminar Ir coating produced at the deposition condition of 20 mA/cm2 (Jm), 10% (R) and 6 Hz (f) was quite smooth (Ra 1.01 ± 0.09 μm) with extremely high degree of preferred orientation of <1 1 1>, and its laminar structure was well developed with clear boundaries and uniform thickness of sub-layers.

Columnar cell lesions without atypia initially diagnosed on breast needle biopsies: is imaging follow-up enough?

PubMed

Seo, Mirinae; Chang, Jung Min; Kim, Won Hwa; Park, In-Ae; Lee, Su Hyun; Cho, Nariya; Moon, Woo Kyung

2013-10-01

The purpose of this study was to evaluate the underestimation rate and predictive factor of underestimation of columnar cell lesions (CCLs) without atypia diagnosed through breast core needle biopsies (CNBs). From January 2007 through December 2011, 141 CCLs without atypia, including columnar cell change and columnar cell hyperplasia, were diagnosed in 138 women by CNB. Excisional (n = 16) or imaging follow-up (n = 125) findings were available in all cases. On a per-lesion basis, the underestimation rate and predictive factor of underestimation were evaluated. Among the 16 surgically excised lesions, there were two malignancies (one ductal carcinoma in situ and one invasive ductal carcinoma) and one lobular carcinoma in situ. Overall, the pooled underestimation rate of malignancy was 1.4% (2/141). With regard to lesion variables, the mean lesion size was significantly larger in the underestimation group of CCLs (p = 0.007). Fine pleomorphic morphology of microcalcifications (p < 0.001), the distribution of the microcalcifications (p = 0.007), BI-RADS final assessment (p = 0.001), and imaging-pathologic correlation (p < 0.001) were significantly associated with underestimation. Multivariate analysis showed that fine pleomorphic morphology of microcalcifications (p < 0.0001) was an independent predictor of underestimation in 58 lesions with microcalcifications on mammography. The overall underestimation rate of malignancy was 1.4%. Imaging follow-up is reasonable for CCLs without atypia at CNB, especially in small lesions with less suspicious imaging findings. Fine pleomorphic microcalcifications and higher BI-RADS category might be helpful in the prediction of underestimation of a high-risk lesion or malignancy.

Aberrant Epithelial-Mesenchymal Hedgehog Signaling Characterizes Barrett's Metaplasia

PubMed Central

Wang, David H.; Clemons, Nicholas J.; Miyashita, Tomoharu; Dupuy, Adam J.; Zhang, Wei; Szczepny, Anette; Corcoran-Schwartz, Ian M.; Wilburn, Daniel L.; Montgomery, Elizabeth A.; Wang, Jean S.; Jenkins, Nancy A.; Copeland, Neal A.; Harmon, John W.; Phillips, Wayne A.; Watkins, D. Neil

2010-01-01

Background & Aims The molecular mechanism underlying epithelial metaplasia in Barrett's esophagus remains unknown. Recognizing that Hedgehog signaling is required for early esophageal development, we sought to determine if the Hedgehog pathway is reactivated in Barrett's esophagus, and if genes downstream of the pathway could promote columnar differentiation of esophageal epithelium. Methods Immunohistochemistry, immunofluorescence, and quantitative real-time PCR were used to analyze clinical specimens, human esophageal cell lines, and mouse esophagi. Human esophageal squamous epithelial (HET-1A) and adenocarcinoma (OE33) cells were subjected to acid treatment and used in transfection experiments. Swiss Webster mice were used in a surgical model of bile reflux injury. An in vivo transplant culture system was created using esophageal epithelium from Sonic hedgehog transgenic mice. Results Marked upregulation of Hedgehog ligand expression, which can be induced by acid or bile exposure, occurs frequently in Barrett's epithelium and is associated with stromal expression of the Hedgehog target genes PTCH1 and BMP4. BMP4 signaling induces expression of SOX9, an intestinal crypt transcription factor, which is highly expressed in Barrett's epithelium. We further show that expression of DMBT1, the human homologue of the columnar cell factor Hensin, occurs in Barrett's epithelium and is induced by SOX9. Finally, transgenic expression of Sonic hedgehog in mouse esophageal epithelium induces expression of stromal Bmp4, epithelial Sox9 and columnar cytokeratins. Conclusions Epithelial Hedgehog ligand expression may contribute to the initiation of Barrett's esophagus through induction of stromal BMP4, which triggers reprogramming of esophageal epithelium in favor of a columnar phenotype. PMID:20138038

Development of Similar Broth Microdilution Methods to Determine the Antimicrobial Susceptibility of Flavobacterium columnare and F. psychrophilum.

PubMed

Gieseker, Charles M; Crosby, Tina C; Mayer, Tamara D; Bodeis, Sonya M; Stine, Cynthia B

2016-03-01

Flavobacterium columnare and F. psychrophilum are major fish pathogens that cause diseases that may require antimicrobial therapy. Choice of appropriate treatment is dependent upon determining the antimicrobial susceptibility of isolates. Therefore we optimized methods for broth microdilution testing of F. columnare and F. psychrophilum to facilitate standardizing an antimicrobial susceptibility test. We developed adaptations to make reproducible broth inoculums and confirmed the proper incubation time and media composition. We tested the stability of potential quality-control bacteria and compared test results between different operators. Log phase occurred at 48 h for F. columnare and 72-96 h for F. psychrophilum, confirming the test should be incubated at 28°C for approximately 48 h and at 18°C for approximately 96 h, respectively. The most consistent susceptibility results were achieved with plain, 4-g/L, dilute Mueller-Hinton broth supplemented with dilute calcium and magnesium. Supplementing the broth with horse serum did not improve growth. The quality-control strains, Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658, yielded stable minimal inhibitory concentrations (MIC) against all seven antimicrobials tested after 30 passes at 28°C and 15 passes at 18°C. In comparison tests, most MICs of the isolates agreed 100% within one drug dilution for ampicillin, florfenicol, and oxytetracycline. The agreement was lower with the ormetoprim-sulfdimethoxine combination, but there was at least 75% agreement for all but one isolate. These experiments have provided methods to help standardize antimicrobial susceptibility testing of these nutritionally fastidious aquatic bacteria. Received June 24, 2015; accepted October 2, 2015.

Multi-phase back contacts for CIS solar cells

DOEpatents

Rockett, A.A.; Yang, L.C.

1995-12-19

Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe{sub 2} where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Mo back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor. 15 figs.

Multi-phase back contacts for CIS solar cells

DOEpatents

Rockett, Angus A.; Yang, Li-Chung

1995-01-01

Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe.sub.2 where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Mo back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor.

Neurenteric Cyst or Neuroendodermal Cyst? Immunohistochemical Study and Pathogenesis.

PubMed

Chen, Chun-Ting; Lai, Hung-Yi; Jung, Shih-Ming; Lee, Ching-Yi; Wu, Chieh-Tsai; Lee, Shih-Tseng

2016-12-01

Neurenteric cysts are rare central nervous system lesions derived from an endodermal origin. There is no consensus concerning pathogenesis because of the paucity of occurrences. We report an immunohistochemical study of 10 cases with neurenteric cysts and postulate its pathogenesis. Ten patients underwent surgical treatment for neurenteric cysts from 1995 to 2015. We retrospectively reviewed clinical, radiologic, operative, and pathologic findings for these patients. Immunohistochemical stains were completed in all cases to distinguish cell type and origin. Three cell types were identified: pseudostratified-ciliated, goblet-columnar, and simple cuboidal cells. All cases were positive for cytokeratin 7, and negative for cytokeratin 20, caudal-type homeobox 2, mucin 2, thyroid transcription factor 1, human chorionic gonadotropin, placental alkaline phosphatase, and cluster of differentiation 31. Four of them had positive staining for mucin 5AC, with expression only in goblet-columnar cells. According to the immunohistochemical results, the cells resembled the respiratory tract (pseudostratified-ciliated), stomach (goblet-columnar), and respiratory bronchioles (simple cuboidal). Seventy-five percent of cases with recurrence had a goblet-columnar component, emphasizing the importance of total resection of the cyst and complete pathologic examination. We postulate that the cystic tumor was derived from multipotent endodermal cells that migrated and traveled along the neuroectoderm, with incomplete differentiation into various cell types as a result of an unsuitable microenvironment. Because the neurenteric canal was only the channel of migration rather than a component of the cysts, the term neuroendodermal cysts is more precise in presenting the embryopathogenesis. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

The tumor suppressor PTEN and the PDK1 kinase regulate formation of the columnar neural epithelium

PubMed Central

Grego-Bessa, Joaquim; Bloomekatz, Joshua; Castel, Pau; Omelchenko, Tatiana; Baselga, José; Anderson, Kathryn V

2016-01-01

Epithelial morphogenesis and stability are essential for normal development and organ homeostasis. The mouse neural plate is a cuboidal epithelium that remodels into a columnar pseudostratified epithelium over the course of 24 hr. Here we show that the transition to a columnar epithelium fails in mutant embryos that lack the tumor suppressor PTEN, although proliferation, patterning and apical-basal polarity markers are normal in the mutants. The Pten phenotype is mimicked by constitutive activation of PI3 kinase and is rescued by the removal of PDK1 (PDPK1), but does not depend on the downstream kinases AKT and mTORC1. High resolution imaging shows that PTEN is required for stabilization of planar cell packing in the neural plate and for the formation of stable apical-basal microtubule arrays. The data suggest that appropriate levels of membrane-associated PDPK1 are required for stabilization of apical junctions, which promotes cell elongation, during epithelial morphogenesis. DOI: http://dx.doi.org/10.7554/eLife.12034.001 PMID:26809587

The defects and microstructure in the fusion zone of multipass laser welded joints with Inconel 52M filler wire for nuclear power plants

NASA Astrophysics Data System (ADS)

Li, Gang; Lu, Xiaofeng; Zhu, Xiaolei; Huang, Jian; Liu, Luwei; Wu, Yixiong

2017-09-01

The defects and microstructure in the fusion zone of multipass laser welded joints with Inconel 52M filler wire are investigated for nuclear power plants. Experimental results indicate that the incomplete fusion forms as the deposited metals do not completely cover the groove during multipass laser welding. The dendritic morphologies are observed on the inner surface of the porosity in the fusion zone. Many small cellular are found in the zones near the fusion boundary. With solidification preceding, cellular gradually turn into columnar dendrites and symmetrical columnar dendrites are exhibited in the weld center of the fusion zone. The fine equiaxed grains form and columnar dendrites disappear in the remelted zone of two passes. The dendrite arm spacing in the fusion zone becomes widened with increasing welding heat input. Nb-rich carbides/carbonitrides are preferentially precipitated in the fusion zone of multipass laser welded joints. In respect to high cooling rate during multipass laser welding, element segregation could be insufficient to achieve the component of Laves phase.

Columnar Transitions in Microscale Evaporating Liquid Jets

NASA Astrophysics Data System (ADS)

Hunter, Hanif; Glezer, Ari

2007-11-01

Microscale evaporating liquid jets that are injected into a quiescent gaseous medium having adjustable ambient pressure are investigated over a range of jet speeds using a shadowgraph technique. The jets are formed by a laser-drilled 10 μm nozzle from a small-scale pressurized reservoir, and sub-atmospheric ambient pressure is maintained using a controllable, metered Venturi pump. The near-field jet features are captured by shadowgraph imaging using a pulsed ND-Yag laser and a 12 bit CCD camera where the field of view measured 200 μm on the side. As the ambient pressure is reduced, the jet column undergoes a series of spectacular transitions that are first marked by the appearance of vapor bubbles within the jet column. The transitions progress from columnar instabilities to series of column bifurcations to high-order branching and film formation and culminate in conical atomization of the jet column. In addition to the effects of the ambient pressure, the present investigation also considers effects of the liquid surface tension and vapor pressure on the onset, evolution, and hysteresis of the columnar transitions.

Who knows not where an anemone does wear his sting? Could polypeptides released from the columnar vesicles of Bunodosoma cangicum induce apoptosis in the ZF-L cell line?

PubMed

Bastos, Claudio L Q; Varela, Antonio Sergio; Ferreira, Shana Pires; Nornberg, Bruna Felix; Boyle, Robert Tew

2016-12-15

We provide ultrastructural and cytological evidence that the tentacles of the sea anemone Bunodosoma cangicum does not contain cytotoxic venom. However, we show that the stimulated secretion of an apparent mixture of biomolecules containing polypeptides from the columnar vesicles of Bunodosoma cangicum is apparently a potent inducer of apoptosis in the zebrafish cell line, ZF-L. Microscopic fluorescence, cell morphology and flow cytometric assays confirm the apoptotic activity. Crude vesicle venom was partially purified by size exclusion chromatography. PAGE analysis shows that this venom contains low weight polypeptides but no measurable protein. The apoptotic activity is heat labile, and the observed peptides concurrent with this activity have a molecular weight of approximately 2000 Da. This manuscript is the first report of biologically active molecules and peptides associated with columnar vesicles of anemones, and the first to confirm that the tentacles of B. cangicum do not contain cytotoxic venom, and express spirocytes exclusively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Strategy for Texture Management in Metals Additive Manufacturing

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

Kirka, Michael M.; Lee, Yousub; Greeley, Duncan A.

Additive manufacturing (AM) technologies have long been recognized for their ability to fabricate complex geometric components directly from models conceptualized through computers, allowing for complicated designs and assemblies to be fabricated at lower costs, with shorter time to market, and improved function. Lacking behind the design complexity aspect is the ability to fully exploit AM processes for control over texture within AM components. Currently, standard heat-fill strategies utilized in AM processes result in largely columnar grain structures. Here, we propose a point heat source fill for the electron beam melting (EBM) process through which the texture in AM materials canmore » be controlled. Using this point heat source strategy, the ability to form either columnar or equiaxed grain structures upon solidification through changes in the process parameters associated with the point heat source fill is demonstrated for the nickel-base superalloy, Inconel 718. Mechanically, the material is demonstrated to exhibit either anisotropic properties for the columnar-grained material fabricated through using the standard raster scan of the EBM process or isotropic properties for the equiaxed material fabricated using the point heat source fill.« less

Columnar domains and anisotropic growth laws in dipolar systems.

PubMed

Bupathy, Arunkumar; Banerjee, Varsha; Puri, Sanjay

2017-06-01

Magnetic and dielectric solids are well-represented by the Ising model with dipolar interactions (IM+DI). The latter are long-ranged, fluctuating in sign, and anisotropic. Equilibrium studies have revealed novel consequences of these complicated interactions, but their effect on nonequilibrium behavior is not explored. We perform a deep temperature quench to study the kinetics of domain growth in the d=3 IM+DI. Our main observations are (i) the emergence of columnar domains along the z axis (Ising axis) with a transient periodicity in the xy plane; (ii) anisotropic growth laws: ℓ_{ρ}(t)∼t^{ϕ}; ℓ_{z}(t)∼t^{ψ}, where ρ[over ⃗]=(x,y) and ℓ is the characteristic length scale; (iii) generalized dynamical scaling for the correlation function: C(ρ,z;t)=g(ρ/ℓ_{ρ},z/ℓ_{z}); and (iv) an asymptotic Porod tail in the corresponding structure factor: S(k_{ρ},0;t)∼k_{ρ}^{-3}; S(0,k_{z};t)∼k_{z}^{-2}. Our results explain the experimentally observed columnar morphologies in a wide range of dipolar systems, and they have important technological implications.

Effect of grain-boundary flux pinning in MgB 2 with columnar structure

NASA Astrophysics Data System (ADS)

Kim, D. H.; Hwang, T. J.; Cha, Y. J.; Seong, W. K.; Kang, W. N.

2009-10-01

We studied the flux pinning properties by grain boundaries in MgB 2 films prepared by using a hybrid physical chemical vapor deposition method on the c-axis oriented sapphire substrates. All the films we report here had the columnar grains with the growth direction perpendicular to the substrates and the grain sizes in the range of a few hundred nanometers. At very low magnetic fields, no discernable grain-boundary (GB) pinning effect was observed in all measuring temperatures, but above those fields, the effect of GB flux pinning was observed as enhanced critical current densities ( Jcs) and reduced resistances when an external magnetic field ( B) was aligned parallel to the c-axis. We interpret the B dependence of Jc in the terms of flux line lattice shear inside the columnar grains activated by dislocations of Frank-Read source while the flux lines pinned by GB act as anchors for dislocations. Magnetic field dependence of flux pinning force density for B parallel to the c-axis was reasonably explained by the above model.

Strategy for Texture Management in Metals Additive Manufacturing

DOE PAGES

Kirka, Michael M.; Lee, Yousub; Greeley, Duncan A.; ...

2017-01-31

Additive manufacturing (AM) technologies have long been recognized for their ability to fabricate complex geometric components directly from models conceptualized through computers, allowing for complicated designs and assemblies to be fabricated at lower costs, with shorter time to market, and improved function. Lacking behind the design complexity aspect is the ability to fully exploit AM processes for control over texture within AM components. Currently, standard heat-fill strategies utilized in AM processes result in largely columnar grain structures. Here, we propose a point heat source fill for the electron beam melting (EBM) process through which the texture in AM materials canmore » be controlled. Using this point heat source strategy, the ability to form either columnar or equiaxed grain structures upon solidification through changes in the process parameters associated with the point heat source fill is demonstrated for the nickel-base superalloy, Inconel 718. Mechanically, the material is demonstrated to exhibit either anisotropic properties for the columnar-grained material fabricated through using the standard raster scan of the EBM process or isotropic properties for the equiaxed material fabricated using the point heat source fill.« less

Influence of the liquid crystal behaviour on the Langmuir and Langmuir-Blodgett film supramolecular architecture of an ionic liquid crystal.

PubMed

Pérez-Gregorio, Víctor; Giner, Ignacio; López, M Carmen; Gascón, Ignacio; Cavero, Emma; Giménez, Raquel

2012-06-01

A new luminescent ionic liquid crystal, called Ipz-2, has been synthesised and its mesophase behaviour and also at the air-liquid interface has been studied and compared with Ipz, another ionic pyrazole derivative, with a similar molecular structure, previously studied. The X-ray diffraction pattern shows that Ipz-2 exhibits hexagonal columnar mesomorphism, while Ipz adopts lamellar mesophases. Langmuir films of both compounds are flat and homogeneous at large areas per molecule, but create different supramolecular structures under further compression. Ipz-2 Langmuir films have been transferred onto solid substrates, and Atomic Force Microscopy (AFM) images of the Langmuir-Blodgett films have shown that large columnar structures hundreds of nm in diameter are formed on top of the initial monolayer, in contrast with well-defined trilayer LB films obtained for Ipz. Our results show that Ipz-2 has a tendency to stack in columnar arrangements both in liquid crystalline bulk and in Langmuir and Langmuir-Blodgett films. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of diffusion annealing regimes on the structure of Nb3Sn layers in ITER-type bronze-processed wires

NASA Astrophysics Data System (ADS)

Valova-Zaharevskaya, E. G.; Popova, E. N.; Deryagina, I. L.; Abdyukhanov, I. M.; Tsapleva, A. S.

2018-03-01

The goal of the present study is to characterize the growth kinetics and structural parameters of the Nb3Sn layers formed under various regimes of the diffusion annealing of bronze-processed Nb/Cu-Sn composites. The structure of the superconducting layers is characterized by their thickness, average size of equiaxed grains and by the ratio of fractions of columnar and equiaxed grains. It was found that at higher diffusion annealing temperatures (above 650°C) thicker superconducting layers are obtained, but the average sizes of equiaxed Nb3Sn grains even under short exposures (10 h) are much larger than after the long low-temperature annealing. At the low-temperature (575 °C) annealing the relative fraction of columnar grains increases with increasing annealing time. Based on the data obtained, optimal regimes of the diffusion annealing can be chosen, which would on the one hand ensure complete transformation of Nb into Nb3Sn of close to the stoichiometric composition, and on the other hand prevent the formation of coarse and columnar grains.

Tissue analysis of the oyster Crassostrea virginica after the Deepwater Horizon oil spill

NASA Astrophysics Data System (ADS)

Roopnarine, D.; Roopnarine, P. D.; Anderson, L.; Chung, T.

2013-12-01

The Deepwater Horizon accident (DWH) of April 20th, 2010, in the Gulf of Mexico (GoM) released crude oil into the ocean column for 4 months. An estimated 685,000 tons of crude oil was released, making DWH spill the largest accidental spill in maritime history. The immediate impacts of the spill were evident, including oil slicks, fouled beaches and fouled, often dead wildlife. Longer-term impacts are less understood, and reliance on studies of past spills, e.g. Exxon Valdez, may not be applicable given the substantially greater magnitude of DWH (Valdez spilled 37,000 tons) and different environmental settings (predominantly rocky shorelines vs. saltmarsh-dominated coastlines). Many molluscan species exhibit responses to oil spills or other hydrocarbon contamination. Bivalved molluscs are commonly used as bioindicator organisms in part because they concentrate both metals and organic contaminants in their soft tissues. We used the American oyster Crassostrea virginica to measure exposure to and impact of the spill as the abnormal transformation of soft-tissues, or metaplasia. Metaplasia is the reversible transformation of one cell type into another. Molluscan metaplasia has been associated with exposure to petroleum contamination. While oyster epithelium is normally stratified columnar and ciliated, experimental exposures often result in metaplasia of gill, digestive and renal tissues. The occurrence and frequency of metaplasia may also be an indication of the longevity of a spill's impact. For example, individuals of the mussel Mytilus trossulus in Prince William Sound continued to exhibit metaplasia of the digestive gland more than 5 years after the Exxon Valdez spill, with an occurrence directly related to concentrations of PAHs in the animals. We focused on the hypothesis that DWH spill exposure resulted in metaplasia of gill and digestive epithelial tissues, both during and after the spill. Those transformations are eventually reversible, although on an unknown timescale. Specimens examined included: (1) Six individuals from Dauphin Island, Alabama and 7 from Apalachicola Bay, Florida during and after the spill in 2010; and (2) three individuals collected outside of the GoM, from Chesapeake Bay in 2013. All Chesapeake Bay specimens displayed normal, columnar, ciliated gill and digestive epithelia. Four Dauphin Island specimens displayed unciliated, stratified epithelia and vacuolated, atrophied digestive tracts. All Apalachicola Bay specimens presented similar metaplasia. Given the expectation of ciliated tissues, these results suggest a significant frequency of metaplasia in GoM specimens (Fisher's exact test, p=0.0179). The results are preliminary, however, and are being tested with increased sample sizes of control and exposed specimens, as well as GoM specimens collected in years 2011-2013.

Morphology and innervation pattern of the feline urogenital junction.

PubMed

Wrobel, K H; Gürtler, A

2004-12-01

The feline urogenital junction is situated between the extratesticular rete and the spacious initial segments of the efferent ductules. The rete epithelium is cuboidal to low columnar. The rete cells forming the junction rest on a wavy basal lamina, display deep mutual invaginations, possess central nuclei with several infoldings and form a distinct border with the columnar epithelial cells of the initial segments of the ductuli efferentes. The epithelium of the initial segments is composed of ciliated cells and non-ciliated principal cells. The latter are the dominating type and characterized by an apical brush-border and a supranuclear endocytotic apparatus. The stroma of the extratesticular rete contains an abundance of collagen whereas contractile cells are here generally absent. In contrast, the initial segments of the efferent ductules are surrounded by elastic fibres and a layer of contractile cells. All nerves for the feline urogenital junction come from the nervus spermaticus superior. In the epididymal head, small nerve bundles deviate into the septa between the ductules. Single fibres establish a dense network within the muscular coat of the ductuli. At the transition to the extratesticular rete, this network ends abruptly. Nerve fibres in the confines of the rete are associated with blood vessels or proceed to the testicular interior, but establish no relationships with the rete epithelium or the myofibroblasts of the mediastinum. The nervous network in the walls of the efferent ductules and their initial segments is not only composed of sympathetic but also parasympathetic, non-myelinated fibres. Particularly noteworthy is the abundance of calcitonin gene-related peptide (CGRP)- and substance P (SP)-containing axons around the initial segments. Both neuroproteins are consistent markers for sensory neurones. Taken together, it can be assumed that the entry of seminal fluid and spermatozoa into the efferent ductules is controlled by a regulatory nervous chain provided with afferent and efferent components.

Homeotropic alignment of dendritic columnar liquid crystal induced by hydrogen-bonded triphenylene core bearing fluoroalkyl chains.

PubMed

Ishihara, Shinsuke; Furuki, Yusuke; Hill, Jonathan P; Ariga, Katsuhiko; Takeoka, Shinji

2014-07-01

A 1:3 molar complex of the fluoroalkyl side chain-substituted 2,6,10-tris-carboxymethoxy-3,7,11-tris(4,4,5,5,6,6,7,7,7-nonafluoroheptyloxy)triphenylene (TPF4) with the second generation dendron 3,5-bis(3,4-bis-dodecyloxybenzyloxy)-N-pyridin-4-yl-benzamide (DN) assembled through complementary hydrogen bonding to form a supramolecular columnar liquid crystal, which exhibited homeotropic alignment when sandwiched between octadecyltrichlorosilane (OTS)-coated or indium tin oxide (ITO)-coated glass plates due to specific interactions between the fluoroalkyl side chains and the substrates.

Statistical mechanics of neocortical interactions. Derivation of short-term-memory capacity

NASA Astrophysics Data System (ADS)

Ingber, Lester

1984-06-01

A theory developed by the author to describe macroscopic neocortical interactions demonstrates that empirical values of chemical and electrical parameters of synaptic interactions establish several minima of the path-integral Lagrangian as a function of excitatory and inhibitory columnar firings. The number of possible minima, their time scales of hysteresis and probable reverberations, and their nearest-neighbor columnar interactions are all consistent with well-established empirical rules of human short-term memory. Thus, aspects of conscious experience are derived from neuronal firing patterns, using modern methods of nonlinear nonequilibrium statistical mechanics to develop realistic explicit synaptic interactions.

Beyond Scale-Free Small-World Networks: Cortical Columns for Quick Brains

NASA Astrophysics Data System (ADS)

Stoop, Ralph; Saase, Victor; Wagner, Clemens; Stoop, Britta; Stoop, Ruedi

2013-03-01

We study to what extent cortical columns with their particular wiring boost neural computation. Upon a vast survey of columnar networks performing various real-world cognitive tasks, we detect no signs of enhancement. It is on a mesoscopic—intercolumnar—scale that the existence of columns, largely irrespective of their inner organization, enhances the speed of information transfer and minimizes the total wiring length required to bind distributed columnar computations towards spatiotemporally coherent results. We suggest that brain efficiency may be related to a doubly fractal connectivity law, resulting in networks with efficiency properties beyond those by scale-free networks.

CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

NASA Astrophysics Data System (ADS)

Liu, D. R.; Mangelinck-Noël, N.; Gandin, Ch-A.; Zimmermann, G.; Sturz, L.; Nguyen Thi, H.; Billia, B.

2016-03-01

A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement.

Ultraviolet spectrophotometer for measuring columnar atmospheric ozone from aircraft

NASA Technical Reports Server (NTRS)

Hanser, F. A.; Sellers, B.; Briehl, D. C.

1978-01-01

An ultraviolet spectrophotometer (UVS) to measure downward solar fluxes from an aircraft or other high altitude platform is described. The UVS uses an ultraviolet diffuser to obtain large angular response with no aiming requirement, a twelve-position filter wheel with narrow (2-nm) and broad (20-nm) bandpass filters, and an ultraviolet photodiode. The columnar atmospheric ozone above the UVS (aircraft) is calculated from the ratios of the measured ultraviolet fluxes. Comparison with some Dobson station measurements gives agreement to 2%. Some UVS measured ozone profiles over the Pacific Ocean for November 1976 are shown to illustrate the instrument's performance.

Free and esterified oxysterol: formation during copper-oxidation of low density lipoprotein and uptake by macrophages.

PubMed

Brown, A J; Dean, R T; Jessup, W

1996-02-01

We have defined the lipid composition of copper-oxidized LDL (Cu-oxLDL) and a macrophage-foam cell model generated by the uptake of this modified lipoprotein. An HPLC method previously developed by our group for the measurement of lipid oxidation products of LDL was extended to permit the analysis of an array of 7-ketocholesteryl esters. Gas chromatography was used for the quantitation of oxysterols (free and esterified) in Cu-oxLDL and their subsequent uptake by macrophages. LDL (1.0 mg protein/ml) was oxidized using Cu(II) (20 microM) for up to 48 h at 37 degrees C. Resident mouse peritoneal macrophages were incubated with 24 h Cu-oxLDL (50 micrograms/ml) for 24 h. In 24 h Cu-oxLDL, cholesterol comprised approximately 50% of total sterols, 7-ketocholesterol comprised approximately 30% with five other oxysterols comprising the remainder (7 alpha- and 7 beta-hydroxycholesterol, cholesterol alpha- and beta-epoxides, and 6 beta-hydroxycholesterol). Macrophages that were incubated with 24 h Cu-oxLDL displayed a profile of oxysterols remarkably similar to that of 24 h Cu-oxLDL itself. The majority of cholesteryl esters and 7-ketocholesteryl esters in Cu-oxLDL and in Cu-oxLDL-loaded macrophages contained fatty acyl chains which are presumed oxidized. This work represents a comprehensive survey of free and esterified oxysterols in Cu-oxLDL and Cu-oxLDL-loaded macrophages and provides a basis for exploring how oxysterols are metabolized by macrophages and authentic human foam cells, and how, in turn, these oxysterols influence cellular metabolism.

Lipase-catalyzed kinetic resolution of novel antitubercular benzoxazole derivatives.

PubMed

Łukowska-Chojnacka, Edyta; Kowalkowska, Anna; Napiórkowska, Agnieszka

2018-04-01

Novel benzoxazole derivatives were synthesized, and their antitubercular activity against sensitive and drug-resistant Mycobacterium tuberculosis strains (M. tuberculosis H 37 Rv, M. tuberculosis sp. 210, M. tuberculosis sp. 192, Mycobacterium scrofulaceum, Mycobacterium intracellulare, Mycobacterium fortuitum, Mycobacterium avium, and Mycobacterium kansasii) was evaluated. The chemical step included preparation of ketones, alcohols, and esters bearing benzoxazole moiety. All racemic mixtures of alcohols and esters were separated in Novozyme SP 435-catalyzed transesterification and hydrolysis, respectively. The transesterification reactions were carried out in various organic solvents (tert-butyl methyl ether, toluene, diethyl ether, and diisopropyl ether), and depending on the solvent, the enantioselectivity of the reactions ranged from 4 to >100. The enzymatic hydrolysis of esters was performed in 2 phase tert-butyl methyl ether/phosphate buffer (pH = 7.2) system and provided also enantiomerically enriched products (ee 88-99%). The antitubercular activity assay has shown that synthesized compounds exhibit an interesting antitubercular activity. Racemic mixtures of alcohols, (±)-4-(1,3-benzoxazol-2-ylsulfanyl)butan-2-ol ((±)-3a), (±)-4-[(5-bromo-1,3-benzoxazol-2-yl)sulfanyl]butan-2-ol ((±)-3b), and (±)-4-[(5,7-dibromo-1,3-benzoxazol-2-yl)sulfanyl]butan-2-ol ((±)-3c), displayed as high activity against M. scrofulaceum, M. intracellulare, M. fortuitum, and M. kansasii as commercially available antituberculosis drug-Isoniazid. Moreover, these compounds exhibited twice higher activity toward M. avium (MIC 12.5) compared with Isoniazid (MIC 50). © 2017 Wiley Periodicals, Inc.

Substrate specificity and kinetic properties of enzymes belonging to the hormone-sensitive lipase family: comparison with non-lipolytic and lipolytic carboxylesterases.

PubMed

Chahinian, Henri; Ali, Yassine Ben; Abousalham, Abdelkarim; Petry, Stefan; Mandrich, Luigi; Manco, Guiseppe; Canaan, Stephane; Sarda, Louis

2005-12-30

We have studied the kinetics of hydrolysis of triacylglycerols, vinyl esters and p-nitrophenyl butyrate by four carboxylesterases of the HSL family, namely recombinant human hormone-sensitive lipase (HSL), EST2 from Alicyclobacillus acidocaldarius, AFEST from Archeoglobus fulgidus, and protein RV1399C from Mycobacterium tuberculosis. The kinetic properties of enzymes of the HSL family have been compared to those of a series of lipolytic and non-lipolytic carboxylesterases including human pancreatic lipase, guinea pig pancreatic lipase related protein 2, lipases from Mucor miehei and Thermomyces lanuginosus, cutinase from Fusarium solani, LipA from Bacillus subtilis, porcine liver esterase and Esterase A from Aspergilus niger. Results indicate that human HSL, together with other lipolytic carboxylesterases, are active on short chain esters and hydrolyze water insoluble trioctanoin, vinyl laurate and olive oil, whereas the action of EST2, AFEST, protein RV1399C and non-lipolytic carboxylesterases is restricted to solutions of short chain substrates. Lipolytic and non-lipolytic carboxylesterases can be differentiated by their respective value of K(0.5) (apparent K(m)) for the hydrolysis of short chain esters. Among lipolytic enzymes, those possessing a lid domain display higher activity on tributyrin, trioctanoin and olive oil suggesting, then, that the lid structure contributes to enzyme binding to triacylglycerols. Progress reaction curves of the hydrolysis of p-nitrophenyl butyrate by lipolytic carboxylesterases with lid domain show a latency phase which is not observed with human HSL, non-lipolytic carboxylesterases, and lipolytic enzymes devoid of a lid structure as cutinase.

CuH-catalysed hydroamination of arylalkynes with hydroxylamine esters – a computational scrutiny of rival mechanistic pathways† †Electronic supplementary information (ESI) available: Complete account of all examined pathways, computational details, full description of reported key species (energies and Cartesian coordinates in angstroms). See DOI: 10.1039/c7sc01107e Click here for additional data file.

PubMed Central

Tobisch, Sven

2017-01-01

An in-depth computational mechanistic probe of the CuH-mediated hydroamination of internal arylalkynes with an archetype hydroxylamine ester and hydrosilane by a (Xantphos)CuH catalyst (Xantphos ≡ {P^P} ≡ 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene) is presented. This first comprehensive computational study of the CuH-mediated electrophilic alkyne hydroamination has identified the most accessible pathway for the rival avenues for direct and reductive hydroamination. The mechanistic picture derived from smooth energy profiles obtained by employing a reliable computational protocol applied to a realistic catalyst model conforms to all available experimental data. The crucial vinyl- and alkylcopper intermediates were found to display a distinct chemodivergence in their reactivity towards amine electrophile and alcohol, which ensures the successful formation of α-branched alkylamines together with (E)-enamines. On the one hand, the vinylcopper is somewhat preferably approached by the alcohol, thereby rendering the reductive hydroamination avenue favourable in the presence of both amine electrophile and alcohol. In contrast, the greater kinetic demands for protonation versus electrophilic amination predicted for the alkylcopper prevents the reductive hydroamination avenue to become non-productive. Electronically modified hydroxylamine esters are found to influence the chemoselectivity in reactivity towards amine electrophile and alcohol achievable for the vinyl- and alkylcopper, thereby offering an opportunity for process improvement. PMID:28660063

Stabilization of Resveratrol in Blood Circulation by Conjugation to mPEG and mPEG-PLA Polymers: Investigation of Conjugate Linker and Polymer Composition on Stability, Metabolism, Antioxidant Activity and Pharmacokinetic Profile

PubMed Central

Siddalingappa, Basavaraj; Benson, Heather A. E.; Brown, David H.; Batty, Kevin T.; Chen, Yan

2015-01-01

Resveratrol is naturally occurring phytochemical with diverse biological activities such as chemoprevention, anti-inflammatory, anti-cancer, anti-oxidant. But undergoes rapid metabolism in the body (half life 0.13h). Hence Polymer conjugation utilizing different chemical linkers and polymer compositions was investigated for enhanced pharmacokinetic profile of resveratrol. Ester conjugates such as α-methoxy-ω-carboxylic acid poly(ethylene glycol) succinylamide resveratrol (MeO-PEGN-Succ-RSV) (2 and 20 kDa); MeO-PEG succinyl ester resveratrol (MeO-PEGO-Succ-RSV) (2 kDa); α-methoxy poly(ethylene glycol)-co-polylactide succinyl ester resveratrol (MeO-PEG-PLAO-Succ-RSV) (2 and 6.6kDa) were prepared by carbodiimide coupling reactions. Resveratrol-PEG ethers (2 and 5 kDa) were synthesized by alkali-mediated etherification. All polymer conjugates were fully characterized in vitro and the pharmacokinetic profile of selected conjugates was characterized in rats. Buffer and plasma stability of conjugates was dependent on polymer hydrophobicity, aggregation behavior and PEG corona, with MeO-PEG-PLAO-Succ-RSV (2 kDa) showing a 3h half-life in rat plasma in vitro. Polymer conjugates irrespective of linker chemistry protected resveratrol against metabolism in vitro. MeO-PEG-PLAO-Succ-RSV (2 kDa), Resveratrol-PEG ether (2 and 5 kDa) displayed improved pharmacokinetic profiles with significantly higher plasma area under curve (AUC), slower clearance and smaller volume of distribution, compared to resveratrol. PMID:25799413

Molecules mediating adhesion of T and B cells, monocytes and granulocytes to vascular endothelial cells.

PubMed Central

Prieto, J; Beatty, P G; Clark, E A; Patarroyo, M

1988-01-01

Leucocytes interact with vascular endothelial cells (EC), and adhesion between these two cell types in vitro is modulated by phorbol ester. Monocytes were found to display the highest basal adhesion to EC, followed by Epstein-Barr virus-immortalized normal B cells (EBV-B), T cells and granulocytes. Phorbol ester treatment increased the adhesion of all types of leucocytes, except monocytes. In the presence of this compound, monoclonal antibody 60.3 to GP90 (CD18, a leucocyte-adhesion protein which is non-covalently associated to either GP160, GP155, or GP130) was found to inhibit the adhesion of the four types of leucocytes to a considerable extent, while anti-lymphocyte function-associated antigen-1 (LFA-1) antibody to GP160 (CD11a) inhibited the adhesion of T and B cells only. Antibody 60.1 to GP155 (CD11b) had a major inhibitory activity exclusively on granulocytes, while antibody LB-2, which recognizes a distinct adhesion molecule (GP84) and, in contrast to the previous antibodies, reacts with EC, mainly inhibited adhesion of EBV-B and did not increase the inhibition obtained with antibody 60.3 alone. Fab fragments of antibody 60.3 inhibited leucocyte adhesion more efficiently, in either the absence or presence of phorbol ester, than the intact antibody molecule. It is concluded the GP90, either alone or associated to the larger glycoproteins, mediates the adhesion in all types of leucocytes, while GP84 mediates the adhesion of the activated B cells. Images Figure 2 PMID:3259203

Migration Rate Inhibition of Breast Cancer Cells Treated by Caffeic Acid and Caffeic Acid Phenethyl Ester: An In Vitro Comparison Study.

PubMed

Kabała-Dzik, Agata; Rzepecka-Stojko, Anna; Kubina, Robert; Jastrzębska-Stojko, Żaneta; Stojko, Rafał; Wojtyczka, Robert Dariusz; Stojko, Jerzy

2017-10-19

One of the deadliest cancers among women is a breast cancer. Research has shown that two natural substances occurring in propolis, caffeic acid (CA) and caffeic acid phenethyl ester (CAPE), have significant anticancer effects. The purpose of our in vitro study was to compare cytotoxic activity and migration rate inhibition using CA and CAPE (doses of 50 and 100 µm) against triple-negative, MDA-MB-231 breast adenocarcinoma line cells, drawn from Caucasian women. Viability was measured by XTT-NR-SRB assay (Tetrazolium hydroxide-Neutral Red-Sulforhodamine B) for 24 h and 48 h periods. Cell migration for wound healing assay was taken for 0 h, 8 h, 16 h, and 24 h periods. CAPE displayed more than two times higher cytotoxicity against MDA-MB-231 cells. IC 50 values for the XTT assay were as follows: CA for 24 h and 48 h were 150.94 µM and 108.42 µM, respectively, while CAPE was 68.82 µM for 24 h and 55.79 µM for 48 h. For the NR assay: CA was 135.85 µM at 24 h and 103.23 µM at 48 h, while CAPE was 64.04 µM at 24 h and 53.25 µM at 48 h. For the SRB assay: CA at 24 h was 139.80 µM and at 48 h 103.98 µM, while CAPE was 66.86 µM at 24 h and 47.73 µM at 48 h. Both agents suspended the migration rate; however, CAPE displayed better activity. Notably, for the 100 µM CAPE dose, motility of the tested breast carcinoma cells was halted.

Poly(ferulic acid-co-tyrosine): Effect of the Regiochemistry on the Photophysical and Physical Properties en Route to Biomedical Applications

PubMed Central

2015-01-01

The photophysical and mechanical properties of novel poly(carbonate-amide)s derived from two biorenewable resources, ferulic acid (FA) and l-tyrosine ethyl ester, were evaluated in detail. From these two bio-based precursors, a series of four monomers were generated (having amide and/or carbonate coupling units with remaining functionalities to allow for carbonate formation) and transformed to a series of four poly(carbonate-amide)s. The simplest monomer, which was biphenolic and was obtained in a single amidation synthetic step, displayed bright, visible fluorescence that was twice brighter than FA. Multidimensional fluorescence spectroscopy of the polymers in solution highlighted the strong influence that regioselectivity and the degree of polymerization have on their photophysical properties. The regiochemistry of the system had little effect on the wettability, surface free energy, and Young’s modulus (ca. 2.5 GPa) in the solid state. Confocal imaging of solvent-cast films of each polymer revealed microscopically flat surfaces with fluorescent emission deep into the visible region. Fortuitously, one of the two regiorandom polymers (obtainable from the biphenolic monomer in only an overall two synthetic steps from FA and l-tyrosine ethyl ester) displayed the most promising fluorescent properties both in the solid state and in solution, allowing for the possibility of translating this system as a self-reporting or imaging agent in future applications. To further evaluate the potential of this polymer as a biodegradable material, hydrolytic degradation studies at different pH values and temperatures were investigated. Additionally, the antioxidant properties of the degradation products of this polymer were compared with its biphenolic monomer and FA. PMID:25364040

Assembly, Elasticity, and Structure of Lyotropic Chromonic Liquid Crystals and Disordered Colloids

NASA Astrophysics Data System (ADS)

Davidson, Zoey S.

This dissertation describes experiments which explore the structure and dynamics in two classes of soft materials: lyotropic chromonic liquid crystals and colloidal glasses and super-cooled liquids. The first experiments found that the achiral LCLCs, sunset yellow FCF (SSY) and disodium cromoglycate (DSCG) both exhibit spontaneous mirror symmetry breaking in the nematic phase driven by a giant elastic anisotropy of their twist modulus compared to their splay and bend moduli. Resulting structures of the confined LCLCs display interesting director configurations due to interplay of topologically required defects and twisted director fields. At higher concentrations, the LCLC compounds form columnar phases. We studied the columnar phase confined within spherical drops and discovered and understood configurations of the LC that sometimes led to non-spherical droplet shapes. The second experiments with SSY LCLCs confined in hollow cylinders uncovered director configurations which were driven in large measure by an exotic elastic modulus known as saddle-splay. We measured this saddle-splay modulus in a LCLC for the first time and found it to be more than 50 times greater than the twist elastic modulus. This large relative value of the saddle-splay modulus violates a theoretical result/assumption known as the Ericksen inequality. A third group of experiments on LCLCs explored the drying process of sessile drops containing SSY solutions, including evaporation dynamics, morphology, and deposition patterns. These drops differ from typical, well-studied evaporating colloidal drops primarily due to the LCLC's concentration-dependent isotropic, nematic, and columnar phases. Phase separation occurs during evaporation, creating surface tension gradients and significant density and viscosity variation within the droplet. Thus, the drying multiphase drops exhibit new convective currents, drop morphologies, deposition patterns, as well as a novel ordered crystalline phase. Finally, experiments in colloidal glasses and super-cooled liquids were initiated to probe the relationship between structure and dynamics in their constituent particles. The displacements of individual particles in the colloids can be decomposed into small cage fluctuations and large rearrangements into new cages. We found a correlation between the rate of rearrangement and the local cage structure associated with each particle. Particle trajectories of a two-dimensional binary mixture of soft colloids are captured by video microscopy. We use a machine learning method to calculate particle "softness'', which indicates the likelihood of rearrangement based on many radial structural features for each particle. We measured the residence time between consecutive rearrangements and related probability distribution functions (PDFs). The softness-dependent conditional PDF is well fit by an exponential with decay time decreasing monotonically with increasing softness. Using these data and a simple thermal activation model, we determined activation energies for rearrangements.

Nitric oxide synthase and the acetylcholine receptor in the prefrontal cortex: metasynaptic organization of the brain.

PubMed

Csillik, B; Nemcsók, J; Boncz, I; Knyihár-Csillik, E

1998-01-01

Nitric oxide synthase (NOS) and the nicotinic acetylcholine receptor (nAChR) immunoreactivity of the cerebral cortex was studied in adult Macaca fascicularis monkeys at light- and electron microscopic levels. NOS was located by means of the polyclonal antibodies developed by Transduction Laboratories (Lexington, KY, USA), as primary serum, in a dilution of 1:1000, and nAChR was located by means of biotinylated alpha-bungarotoxin (BTX) obtained from Molecular probes (Eugene, Oregon, USA) in a dilution of 1:2000. While endothelial eNOS outlined blood vessels in the brain, brain-derived (neural) bNOS labelled three well-defined cell types in area 46 of the prefrontal cortex, viz. (a) bipolar cells, scattered through layers III to V, equipped with long dendrites which pass over the thickness of the cortex in a right angle to the pial surface, establishing dendritic bundles closely reminiscent of a columnar organization; (b) large multipolar cells, located mainly in layers V and VI, with axons which interconnect dendritic bundles of the bipolar cells and establish synapses with dendritic shafts and spines of the former; and (c) stellate cells, located in lamina II and III, which establish an axonal network in lamina zonalis (lamina I). This arrangement is most characteristic in area 46 of the prefrontal cortex; areas 10 and 12 display similar features. In contrast, the primary visual cortex (area 17), is lacking any sign of columnar organization. Localization of bNOS immunoreactivity is at marked variance to that of NADPH-diaphorase which labels large pyramidal cells in the primate cortex. Binding of alpha-bungarotoxin (BTX) which labels the alpha 7 subunit of nAChR is located in somata, dendrites and axons of interneurons scattered over the entire width of the prefrontal cortex; on the other hand, the monoclonal antibody mAb 35 which labels subunits alpha 1, alpha 3 and alpha 5 in the main immunogenic region of the receptor, visualizes apical dendritic shafts similar to those like bNOS. Strategic localization of bNOS in the primate prefrontal cortex fulfills criteria of producing a freely diffusing retrograde messenger molecule operative in signal transduction routes subserving topography and columnar organization of the cortex, as well as long-term potentiation and long-term depression phenomena underlying mnemonic and gnostic functions. Common occurrence of bNOS and nAChR in identical or similar structures in the prefrontal cortex suggests that interactions between nitrogen oxide and presynaptically released acetylcholine might be involved in the metasynaptic organization of the cerebral cortex, operating in a non-synaptic manner in maintaining optimal performance on cognitive tasks.

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

Peter, William H.; Nandwana, Peeyush; Kirka, Michael M.

In this project, Avure and ORNL evaluated the influence of hot isostatic pressing (HIP) and thermal cycling as standalone post processing techniques on the microstructure of electron beam powder bed deposited Ti-6Al-4V and Inconel 718 alloys. Electron beam powder bed deposition is an effective technology for fabricating complex net shape components that cannot be manufactured with conventional processes. However, material deposited by this technology results in columnar grain growth which is detrimental for many applications. For Ti-6Al-4V, it has been found that thermal cycling alone is not sufficient to breakdown the columnar microstructure that is typical of electron beam powdermore » bed technology. HIP, on the other hand, has the potential to be an effective technique to break down the columnar microstructure of Ti-6Al-4V into a more equiaxed and refined β grain structure, and provide a more homogeneous microstructure compared to the thermally cycled samples. Overall, the project showed that hot isostatic pressing reduced/eliminated porosity in both Ti-6Al-4V and Inconel 718 However, based on the unique thermal cycle and the application of pressure in the HIP vessel, Ti-6Al-4V e-beam deposited microstructures were modified from columnar grain growth to equiaxed microstructures; a significant outcome to this collaboration. Inconel 718, on the other hand, shows no change in the macrostructure as a result of the current HIP cycle based on the thermal history, and would require further investigation. Though the results of HIP cycle were very good at changing the microstructure, further development in optimizing the post heat treatments and HIP cycles is required to improve mechanical properties.« less

Applications of a pnCCD detector coupled to columnar structure CsI(Tl) scintillator system in ultra high energy X-ray Laue diffraction

NASA Astrophysics Data System (ADS)

Shokr, M.; Schlosser, D.; Abboud, A.; Algashi, A.; Tosson, A.; Conka, T.; Hartmann, R.; Klaus, M.; Genzel, C.; Strüder, L.; Pietsch, U.

2017-12-01

Most charge coupled devices (CCDs) are made of silicon (Si) with typical active layer thicknesses of several microns. In case of a pnCCD detector the sensitive Si thickness is 450 μm. However, for silicon based detectors the quantum efficiency for hard X-rays drops significantly for photon energies above 10 keV . This drawback can be overcome by combining a pixelated silicon-based detector system with a columnar scintillator. Here we report on the characterization of a low noise, fully depleted 128×128 pixels pnCCD detector with 75×75 μm2 pixel size coupled to a 700 μm thick columnar CsI(Tl) scintillator in the photon range between 1 keV to 130 keV . The excellent performance of the detection system in the hard X-ray range is demonstrated in a Laue type X-ray diffraction experiment performed at EDDI beamline of the BESSY II synchrotron taken at a set of several GaAs single crystals irradiated by white synchrotron radiation. With the columnar structure of the scintillator, the position resolution of the whole system reaches a value of less than one pixel. Using the presented detector system and considering the functional relation between indirect and direct photon events Laue diffraction peaks with X-ray energies up to 120 keV were efficiently detected. As one of possible applications of the combined CsI-pnCCD system we demonstrate that the accuracy of X-ray structure factors extracted from Laue diffraction peaks can be significantly improved in hard X-ray range using the combined CsI(Tl)-pnCCD system compared to a bare pnCCD.

Water availability and the competitive effect of a columnar cactus on its nurse plant

NASA Astrophysics Data System (ADS)

Flores-Martínez, Arturo; Ezcurra, Exequiel; Sánchez-Colón, Salvador

1998-02-01

A field study was conducted in a semi-arid tropical ecosystem in Mexico to test whether competition for soil water is the causal mechanism underlying the negative effect of the columnar cactus Neobuxbaumia tetetzo on its nurse plant Mimosa luisana and to examine how this relationship varies over time. The effect of irrigation was evaluated by recording the production of leaves, modules (i.e. internodes with an axillary bud), inflorescences and fruits in shrubs growing either isolated or associated with juvenile or adult columnar cacti. 4 001 of water, in five doses of 801 each every 15 d, were added to the treatment plants; no water other than rainfall was added to control plants. Additionally, to evaluate how the effect of the columnar cacti on the shrubs may vary among years we made a comparison of the production of plant structures between 2 years of contrasting rainfall. The irrigation treatment increased the production of modules, inflorescences and fruits, but not of leaves. Shrub response to watering was also dependent on class of association: those associated with juvenile cacti showed a higher response to irrigation than any other treatment. Our results show that water addition increases the production of structures and partially reduces the negative effect of the cactus on nurse shrub, thus supporting the hypothesis of competition for water. The negative effect of the cacti on their nurse plants was present during both years of observations, but the intensity of the negative effect varies from relatively wet to dry years. The results are discussed in relation to how temporal changes in resource availability affect the results of competitive interactions and the importance of this mechanism in the structure and dynamics of this dryland community.

Columnar Metaplasia in Three Types of Surgical Mouse Models of Esophageal Reflux.

PubMed

Terabe, Fabio; Aikou, Susumu; Aida, Junko; Yamamichi, Nobutake; Kaminishi, Michio; Takubo, Kaiyo; Seto, Yasuyuki; Nomura, Sachiyo

2017-07-01

Esophageal adenocarcinoma develops in the setting of gastroesophageal reflux and columnar metaplasia in distal esophagus. Columnar metaplasia arising in gastroesophageal reflux models has developed in rat; however, gastroesophageal reflux models in mice have not been well-characterized. One hundred thirty-five C57Bl/6J mice aged 8 weeks old were divided into the following operations: esophagogastrojejunostomy (side-to-side) (EGJ), esophageal separation and esophagojejunostomy (end-to-side) (EJ), and EJ and gastrectomy (end-to-side) (EJ/TG). The animals were euthanized after 40 weeks and the histology of the junction was examined. Immunohistochemistry for p53, PDX-1, and CDX-2 was performed. Metaplasia developed in 15/33 (45.5%) of EGJ, 0/38 (0%) of EJ, and 6/39 (15.4%) of EJ/TG ( P < .05) and dysplasia developed 7/33 (21.2%) of EGJ, 0% of EJ, and 1/39 (2.6%) of EJ/TG. p53 was positive in all of the dysplastic regions, 12/15 (80%) metaplasias in the EGJ model, and 1/6 (16.7%) metaplasia in the EJ/TG model. CDX-2 was positive in all cases of metaplasias, but decreased in some cases of dysplasia. PDX-1 was positive in 7/8 (88%) cases of dysplasia and in 15/21 (71%) cases of metaplasia ( P < .05). The EGJ model, which causes reflux of gastric acid and duodenal content, developed metaplasia and dysplasia most frequently. No metaplasia developed in the EJ model in which gastric juice and duodenal content mixed before reflux. Thus, duodenal contents alone can induce columnar metaplasia and dysplasia; however, the combination of gastric acid with duodenal content reflux can cause metaplasia and dysplasia more efficiently.

Methods of refining and producing dibasic esters and acids from natural oil feedstocks

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

Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

Methods and systems for making dibasic esters and/or dibasic acids using metathesis are generally disclosed. In some embodiments, the methods comprise reacting a terminal olefin ester with an internal olefin ester in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In some embodiments, the terminal olefin ester or the internal olefin ester are derived from a renewable feedstock, such as a natural oil feedstock. In some such embodiments, the natural oil feedstock, or a transesterified derivative thereof, is metathesized to make the terminal olefin ester or the internal olefin ester.

Methods of refining and producing isomerized fatty acid esters and fatty acids from natural oil feedstocks

DOEpatents

Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.; Beltran, Leslie V.; Kunz, Linda A.; Pals, Tessa M.; Quinn, Jordan R; Behrends, Jr., Raymond T.; Bernhardt, Randal J.

2016-07-05

Methods are provided for refining natural oil feedstocks and producing isomerized esters and acids. The methods comprise providing a C4-C18 unsaturated fatty ester or acid, and isomerizing the fatty acid ester or acid in the presence of heat or an isomerization catalyst to form an isomerized fatty ester or acid. In some embodiments, the methods comprise forming a dibasic ester or dibasic acid prior to the isomerizing step. In certain embodiments, the methods further comprise hydrolyzing the dibasic ester to form a dibasic acid. In certain embodiments, the olefin is formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having unsaturated esters.

Temperature-enhanced alumina HPLC method for the analysis of wax esters, sterol esters, and methyl esters.

PubMed

Moreau, Robert A; Kohout, Karen; Singh, Vijay

2002-12-01

Previous attempts at separating nonpolar lipid esters (including wax esters, sterol esters, and methyl esters) have achieved only limited success. Among the several normal-phase methods tested, a single recent report of a method employing an alumina column at 30 degrees C with a binary gradient system was the most promising. In the current study, modification of the alumina method by increasing the column temperature to 75 degrees C improved the separation of standards of wax esters and sterol esters. Elevated column temperature also enhanced the separation of FAME with differing degrees of unsaturation. Evidence was also presented to indicate that the method similarly separated phytosterol esters, based on their levels of unsaturation. With the increased interest in phytosterol- and phytostanol-ester enriched functional foods, this method should provide a technique to characterize and compare these products.

Identification of Osteoconductive and Biodegradable Polymers from a Combinatorial Polymer Library

PubMed Central

Brey, Darren M.; Chung, Cindy; Hankenson, Kurt D.; Garino, Jonathon P.; Burdick, Jason A.

2012-01-01

Combinatorial polymer syntheses are now being utilized to create libraries of materials with potential utility for a wide variety of biomedical applications. We recently developed a library of photopolymerizable and biodegradable poly(β-amino ester)s (PBAEs) that possessed a range of tunable properties. In this work, the PBAE library was assessed for candidate materials that met design criteria (e.g., physical properties such as degradation and mechanical strength and in vitro cell viability and osteoconductive behavior) for scaffolding in mineralized tissue repair. The most promising candidate, A6, was then processed into 3-dimensional porous scaffolds and implanted subcutaneously and only presented a mild inflammatory response. The scaffolds were then implanted intramuscularly and into a critically-sized cranial defect either alone or loaded with bone morphogenetic protein-2 (BMP-2). The samples in both locations displayed mineralized tissue formation in the presence of BMP-2, as evident through radiographs, micro-computed tomography, and histology, while samples without BMP-2 showed minimal or no mineralized tissue. These results illustrate a process to identify a candidate scaffolding material from a combinatorial polymer library, and specifically for the identification of an osteoconductive scaffold with osteoinductive properties via the inclusion of a growth factor. PMID:20198696

The microsomal dicarboxylyl-CoA synthetase.

PubMed Central

Vamecq, J; de Hoffmann, E; Van Hoof, F

1985-01-01

Dicarboxylic acids are products of the omega-oxidation of monocarboxylic acids. We demonstrate that in rat liver dicarboxylic acids (C5-C16) can be converted into their CoA esters by a dicarboxylyl-CoA synthetase. During this activation ATP, which cannot be replaced by GTP, is converted into AMP and PPi, both acting as feedback inhibitors of the reaction. Thermolabile at 37 degrees C, and optimally active at pH 6.5, dicarboxylyl-CoA synthetase displays the highest activity on dodecanedioic acid (2 micromol/min per g of liver). Cell-fractionation studies indicate that this enzyme belongs to the hepatic microsomal fraction. Investigations about the fate of dicarboxylyl-CoA esters disclosed the existence of an oxidase, which could be measured by monitoring the production of H2O2. In our assay conditions this H2O2 production is dependent on and closely follows the CoA consumption. It appears that the chain-length specificity of the handling of dicarboxylic acids by this catabolic pathway (activation to acyl-CoA and oxidation with H2O2 production) parallels the pattern of the degradation of exogenous dicarboxylic acids in vivo. PMID:4062873

A compound-based proteomic approach discloses 15-ketoatractyligenin methyl ester as a new PPARγ partial agonist with anti-proliferative ability

NASA Astrophysics Data System (ADS)

Vasaturo, Michele; Fiengo, Lorenzo; de Tommasi, Nunziatina; Sabatino, Lina; Ziccardi, Pamela; Colantuoni, Vittorio; Bruno, Maurizio; Cerchia, Carmen; Novellino, Ettore; Lupo, Angelo; Lavecchia, Antonio; Piaz, Fabrizio Dal

2017-01-01

Proteomics based approaches are emerging as useful tools to identify the targets of bioactive compounds and elucidate their molecular mechanisms of action. Here, we applied a chemical proteomic strategy to identify the peroxisome proliferator-activated receptor γ (PPARγ) as a molecular target of the pro-apoptotic agent 15-ketoatractyligenin methyl ester (compound 1). We demonstrated that compound 1 interacts with PPARγ, forms a covalent bond with the thiol group of C285 and occupies the sub-pocket between helix H3 and the β-sheet of the ligand-binding domain (LBD) of the receptor by Surface Plasmon Resonance (SPR), mass spectrometry-based studies and docking experiments. 1 displayed partial agonism of PPARγ in cell-based transactivation assays and was found to inhibit the AKT pathway, as well as its downstream targets. Consistently, a selective PPARγ antagonist (GW9662) greatly reduced the anti-proliferative and pro-apoptotic effects of 1, providing the molecular basis of its action. Collectively, we identified 1 as a novel PPARγ partial agonist and elucidated its mode of action, paving the way for therapeutic strategies aimed at tailoring novel PPARγ ligands with reduced undesired harmful side effects.

Synthesis and in vitro antitumor evaluation of dihydroartemisinin-cinnamic acid ester derivatives.

PubMed

Xu, Cang-Cang; Deng, Ting; Fan, Meng-Lin; Lv, Wen-Bo; Liu, Ji-Hua; Yu, Bo-Yang

2016-01-01

To explore novel high efficiency and low toxicity antitumor agents, a series of dihydroartemisinin-cinnamic acid ester derivatives modified on C-12 and/or C-9 position (s) were synthesized and the in vitro antitumor activities against PC-3, SGC-7901, A549 and MDA-MB-435s cancer cell lines were assessed. The hybrids (3-36) were prepared by esterification of 9α-hydroxyl-dihydroartemisinin (9α-OH DHA), the biotransformation product of dihydroartemisinin (DHA), and cinnamic acid derivatives. Compound 17 (IC50 = 0.20 μM) was the most potent anti-proliferative agent against the human lung carcinoma A549 cells, although it displayed low cytotoxicity on normal hepatic L-02 cells. The mechanism of action of compound 17 was further investigated by analysis of cell apoptosis and intracellular ROS generation. The results indicated that both ROS and ferrous ion contributed to the compound 17-induced cell death. Meanwhile, high intracellular ferrous ion and endogenous oxidative stress in A549 cells made them easier to suffer to compound 17-induced apoptosis. Our promising findings indicated the compound 17 could stand as drug candidate against lung cancer for further investigation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity.

PubMed

Régnier, Philippe; Bastias, Jorge; Rodriguez-Ruiz, Violeta; Caballero-Casero, Noelia; Caballo, Carmen; Sicilia, Dolores; Fuentes, Axelle; Maire, Murielle; Crepin, Michel; Letourneur, Didier; Gueguen, Virginie; Rubio, Soledad; Pavon-Djavid, Graciela

2015-05-07

Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases.

A compound-based proteomic approach discloses 15-ketoatractyligenin methyl ester as a new PPARγ partial agonist with anti-proliferative ability

PubMed Central

Vasaturo, Michele; Fiengo, Lorenzo; De Tommasi, Nunziatina; Sabatino, Lina; Ziccardi, Pamela; Colantuoni, Vittorio; Bruno, Maurizio; Cerchia, Carmen; Novellino, Ettore; Lupo, Angelo; Lavecchia, Antonio; Piaz, Fabrizio Dal

2017-01-01

Proteomics based approaches are emerging as useful tools to identify the targets of bioactive compounds and elucidate their molecular mechanisms of action. Here, we applied a chemical proteomic strategy to identify the peroxisome proliferator-activated receptor γ (PPARγ) as a molecular target of the pro-apoptotic agent 15-ketoatractyligenin methyl ester (compound 1). We demonstrated that compound 1 interacts with PPARγ, forms a covalent bond with the thiol group of C285 and occupies the sub-pocket between helix H3 and the β-sheet of the ligand-binding domain (LBD) of the receptor by Surface Plasmon Resonance (SPR), mass spectrometry-based studies and docking experiments. 1 displayed partial agonism of PPARγ in cell-based transactivation assays and was found to inhibit the AKT pathway, as well as its downstream targets. Consistently, a selective PPARγ antagonist (GW9662) greatly reduced the anti-proliferative and pro-apoptotic effects of 1, providing the molecular basis of its action. Collectively, we identified 1 as a novel PPARγ partial agonist and elucidated its mode of action, paving the way for therapeutic strategies aimed at tailoring novel PPARγ ligands with reduced undesired harmful side effects. PMID:28117438

A compound-based proteomic approach discloses 15-ketoatractyligenin methyl ester as a new PPARγ partial agonist with anti-proliferative ability.

PubMed

Vasaturo, Michele; Fiengo, Lorenzo; De Tommasi, Nunziatina; Sabatino, Lina; Ziccardi, Pamela; Colantuoni, Vittorio; Bruno, Maurizio; Cerchia, Carmen; Novellino, Ettore; Lupo, Angelo; Lavecchia, Antonio; Piaz, Fabrizio Dal

2017-01-24

Proteomics based approaches are emerging as useful tools to identify the targets of bioactive compounds and elucidate their molecular mechanisms of action. Here, we applied a chemical proteomic strategy to identify the peroxisome proliferator-activated receptor γ (PPARγ) as a molecular target of the pro-apoptotic agent 15-ketoatractyligenin methyl ester (compound 1). We demonstrated that compound 1 interacts with PPARγ, forms a covalent bond with the thiol group of C285 and occupies the sub-pocket between helix H3 and the β-sheet of the ligand-binding domain (LBD) of the receptor by Surface Plasmon Resonance (SPR), mass spectrometry-based studies and docking experiments. 1 displayed partial agonism of PPARγ in cell-based transactivation assays and was found to inhibit the AKT pathway, as well as its downstream targets. Consistently, a selective PPARγ antagonist (GW9662) greatly reduced the anti-proliferative and pro-apoptotic effects of 1, providing the molecular basis of its action. Collectively, we identified 1 as a novel PPARγ partial agonist and elucidated its mode of action, paving the way for therapeutic strategies aimed at tailoring novel PPARγ ligands with reduced undesired harmful side effects.

Skin delivery of antioxidant surfactants based on gallic acid and hydroxytyrosol.

PubMed

Alonso, Cristina; Lucas, Ricardo; Barba, Clara; Marti, Meritxell; Rubio, Laia; Comelles, Francesc; Morales, Juan Carlos; Coderch, Luisa; Parra, José Luís

2015-07-01

The aim of this study has been to investigate the dermal absorption profile of the antioxidant compounds gallic acid and hydroxytyrosol as well as their derivatives, hexanoate (hexyl gallate and hydroxytyrosol hexanoate) and octanoate (octyl gallate and octanoate derivative) alkyl esters (antioxidant surfactants). Previously, the scavenging capacity of these compounds, expressed as efficient dose ED50, has also determined. The percutaneous absorption of these compounds was obtained by an in vitro methodology using porcine skin biopsies on Franz static diffusion cells. The antiradical activity of compounds was determined using the 1,1-diphenyl-2-picrylhydrazyl free radical method. The percutaneous penetration results show the presence of antioxidants in all layers of the skin. The content of the cutaneously absorbed compound is higher for the antioxidant surfactants (ester derivatives). This particular behaviour could be due to the higher hydrophobicity of these compounds and the presence of surface activity in the antioxidant surfactants. These new antioxidant surfactants display optimum properties, which may be useful in the preparation of emulsified systems in cosmetic and pharmaceutical formulations because of their suitable surface activity and because they can protect the skin from oxidative damage. © 2015 Royal Pharmaceutical Society.

Motions in the interiors and atmospheres of Jupiter and Saturn. II - Barotropic instabilities and normal modes of an adiabatic planet

NASA Technical Reports Server (NTRS)

Ingersoll, A. P.; Miller, R. L.

1986-01-01

A rotating and adiabatic inviscid fluid planet possesses low frequency motions that are barotropic, quasi-geostrophic and quasi-columnar. The limiting curvature at which flow becomes unstable upon projection onto the planetary surface is negative, with an amplitude that is 3-4 times that for thin atmospheres, in planets in which density linearly decreases to zero at the surface. This result is shown to hold for all quasi-columnar perturbations. Both the phase speed of the normal mode oscillations and the barotropic stability criterion have features in common with Saturn and Jupiter oscillations.

Dielectrophoretic columnar focusing device

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

James, Conrad D; Galambos, Paul C; Derzon, Mark S

2010-05-11

A dielectrophoretic columnar focusing device uses interdigitated microelectrodes to provide a spatially non-uniform electric field in a fluid that generates a dipole within particles in the fluid. The electric field causes the particles to either be attracted to or repelled from regions where the electric field gradient is large, depending on whether the particles are more or less polarizable than the fluid. The particles can thereby be forced into well defined stable paths along the interdigitated microelectrodes. The device can be used for flow cytometry, particle control, and other process applications, including cell counting or other types of particle counting,more » and for separations in material control.« less

A technique for evaluating the influence of spatial sampling on the determination of global mean total columnar ozone

NASA Technical Reports Server (NTRS)

Tolson, R. H.

1981-01-01

A technique is described for providing a means of evaluating the influence of spatial sampling on the determination of global mean total columnar ozone. A finite number of coefficients in the expansion are determined, and the truncated part of the expansion is shown to contribute an error to the estimate, which depends strongly on the spatial sampling and is relatively insensitive to data noise. First and second order statistics are derived for each term in a spherical harmonic expansion which represents the ozone field, and the statistics are used to estimate systematic and random errors in the estimates of total ozone.

Columnar epitaxy of hexagonal and orthorhombic silicides on Si(111)

NASA Technical Reports Server (NTRS)

Fathauer, R. W.; Nieh, C. W.; Xiao, Q. F.; Hashimoto, Shin

1990-01-01

Columnar grains of PtSi and CrSi2 surrounded by high-quality epitaxial silicon are obtained by ultrahigh vacuum codeposition of Si and metal in an approximately 10:1 ratio on Si(111) substrates heated to 610-840 C. This result is similar to that found previously for CoSi2 (a nearly-lattice-matched cubic-fluorite crystal) on Si(111), in spite of the respective orthorhombic and hexagonal structures of PtSi and CrSi2. The PtSi grains are epitaxial and have one of three variants of the relation defined by PtSi(010)/Si(111), with PtSi 001 line/Si 110 line type.

Immunohistochemical expression of CK7, CK5/6, CK19, and p63 in Warthin tumor.

PubMed

Dăguci, Luminiţa; Stepan, A; Mercuţ, Veronica; Dăguci, C; Bătăiosu, Marilena; Florescu, Alma

2012-01-01

Our study included a number of 24 cases with Warthin tumor, diagnosed between 2007-2011, which were analyzed in terms of clinical, histopathological and immunohistochemistry point of view, using CK7, CK5/6, CK19, and p63 antibodies. Warthin tumor is most often a tumor with a slow evolution, painless, usually affecting males (M/F 3.2/1) in the seventh decade of life. Histopathologically, it is distinguished the predominance of the typical forms of the tumor, with a balanced ratio epithelium/stroma. The immunostaining for CK7 showed positivity in all the investigated cases both in the columnar luminal cells and basal cells. The immunostaining for CK5/6 was positive in all the investigated cases in bilayer epithelial basal cells, both in the structure of the cysts and the papillae. In the case of the immunostaining for p63 we noticed limited nuclear positivity in the basal cells, while the columnar cells' nucleus were negative. The immunohistochemical study of the bilayer epithelial component of Warthin tumor showed different immunstaining of the two types of epithelia, the oncocytary columnar and the basal on, similar to those found in the salivary gland ducts.

Doppler measurements of the ionosphere on the occasion of the Apollo-Soyuz test project. Part 1: Computer simulation of ionospheric-induced Doppler shifts

NASA Technical Reports Server (NTRS)

Grossi, M. D.; Gay, R. H.

1975-01-01

A computer simulation of the ionospheric experiment of the Apollo-Soyuz Test Project (ASTP) was performed. ASTP is the first example of USA/USSR cooperation in space and is scheduled for summer 1975. The experiment consists of performing dual-frequency Doppler measurements (at 162 and 324 MHz) between the Apollo Command Service Module (CSM) and the ASTP Docking Module (DM), both orbiting at 221-km height and at a relative distance of 300 km. The computer simulation showed that, with the Doppler measurement resolution of approximately 3 mHz provided by the instrumentation (in 10-sec integration time), ionospheric-induced Doppler shifts will be measurable accurately at all times, with some rare exceptions occurring when the radio path crosses regions of minimum ionospheric density. The computer simulation evaluated the ability of the experiment to measure changes of columnar electron content between CSM and DM (from which horizontal gradients of electron density at 221-km height can be obtained) and to measure variations in DM-to-ground columnar content (from which an averaged columnar content and the electron density at the DM can be deduced, under some simplifying assumptions).

Liquid-phase chromatography detector

DOEpatents

Voigtman, E.G.; Winefordner, J.D.; Jurgensen, A.R.

1983-11-08

A liquid-phase chromatography detector comprises a flow cell having an inlet tubular conduit for receiving a liquid chromatographic effluent and discharging it as a flowing columnar stream onto a vertically adjustable receiving surface spaced apart from and located vertically below and in close proximity to the discharge end of the tubular conduit; a receiver adapted to receive liquid overflowing from the receiving surface; an exit conduit for continuously removing liquid from the receiver; a light source for focusing fluorescence-producing light pulses on the flowing columnar stream as it passes from the outlet of the conduit to the receiving surface and a fluorescence detector to detect the produced fluorescence; a source of light pulse for producing acoustic waves in the columnar stream as it passes from the conduit outlet to the receiving surface; and a piezoelectric transducer adapted to detect those waves; and a source of bias voltage applied to the inlet tubular conduit and adapted to produce ionization of the liquid flowing through the flow cell so as to produce photocurrents therein and an electrical system to detect and record the photocurrents. This system is useful in separating and detecting individual chemical compounds from mixtures thereof. 5 figs.

Hierarchical columnar silicon anode structures for high energy density lithium sulfur batteries

NASA Astrophysics Data System (ADS)

Piwko, Markus; Kuntze, Thomas; Winkler, Sebastian; Straach, Steffen; Härtel, Paul; Althues, Holger; Kaskel, Stefan

2017-05-01

Silicon is a promising anode material for next generation lithium secondary batteries. To significantly increase the energy density of state of the art batteries with silicon, new concepts have to be developed and electrode structuring will become a key technology. Structuring is essential to reduce the macroscopic and microscopic electrode deformation, caused by the volume change during cycling. We report pulsed laser structuring for the generation of hierarchical columnar silicon films with outstanding high areal capacities up to 7.5 mAh cm-2 and good capacity retention. Unstructured columnar electrodes form a micron-sized block structure during the first cycle to compensate the volume expansion leading to macroscopic electrode deformation. At increased silicon loading, without additional structuring, pronounced distortion and the formation of cracks through the current collector causes cell failure. Pulsed laser ablation instead is demonstrated to avoid macroscopic electrode deformation by initial formation of the block structure. A full cell with lithiated silicon versus a carbon-sulfur cathode is assembled with only 15% overbalanced anode and low electrolyte amount (8 μl mgsulfur-1). While the capacity retention over 50 cycles is identical to a cell with high excess lithium anode, the volumetric energy density could be increased by 30%.

Columnar recombination for X-ray generated electron-holes in amorphous selenium and its significance in a-Se x-ray detectors

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

Bubon, O.; Thunder Bay Regional Research Institute, Thunder Bay, Ontario, P7A 7T1; Jandieri, K.

Although amorphous selenium (a-Se) has a long and successful history of application in optical and X-ray imaging, some of its fundamental properties are still puzzling. In particularly, the mechanism of carrier recombination following x-ray excitation and electric field and temperature dependences of the electron-hole pair creation energy (W{sub ehp}) remain unclear. Using the combination of X-ray photocurrent and pulse height spectroscopy measurements, we measure W{sub ehp} in a wide range of temperatures (218–320 K) and electric fields (10–100 V/µm) and show that the conventional columnar recombination model which assumes Langevin recombination within a column (a primary electron track) fails to explain experimentalmore » results in a wide range of electric fields and temperatures. The reason for the failure of the conventional model is revealed in this work, and the theory of the columnar recombination is modified to include the saturation of the recombination rate at high electric field in order to account for the experimental results in the entire range of fields and temperatures.« less

Quantized Self-Assembly of Discotic Rings in a Liquid Crystal Confined in Nanopores

NASA Astrophysics Data System (ADS)

Sentker, Kathrin; Zantop, Arne W.; Lippmann, Milena; Hofmann, Tommy; Seeck, Oliver H.; Kityk, Andriy V.; Yildirim, Arda; Schönhals, Andreas; Mazza, Marco G.; Huber, Patrick

2018-02-01

Disklike molecules with aromatic cores spontaneously stack up in linear columns with high, one-dimensional charge carrier mobilities along the columnar axes, making them prominent model systems for functional, self-organized matter. We show by high-resolution optical birefringence and synchrotron-based x-ray diffraction that confining a thermotropic discotic liquid crystal in cylindrical nanopores induces a quantized formation of annular layers consisting of concentric circular bent columns, unknown in the bulk state. Starting from the walls this ring self-assembly propagates layer by layer towards the pore center in the supercooled domain of the bulk isotropic-columnar transition and thus allows one to switch on and off reversibly single, nanosized rings through small temperature variations. By establishing a Gibbs free energy phase diagram we trace the phase transition quantization to the discreteness of the layers' excess bend deformation energies in comparison to the thermal energy, even for this near room-temperature system. Monte Carlo simulations yielding spatially resolved nematic order parameters, density maps, and bond-orientational order parameters corroborate the universality and robustness of the confinement-induced columnar ring formation as well as its quantized nature.

Analysis of the Microstructure and Thermal Shock Resistance of Laser Glazed Nanostructured Zirconia TBCs

NASA Astrophysics Data System (ADS)

Chen, Hui; Hao, Yunfei; Wang, Hongying; Tang, Weijie

2010-03-01

Nanostructured zirconia thermal barrier coatings (TBCs) have been prepared by atmospheric plasma spraying using the reconstituted nanosized yttria partially stabilized zirconia powder. Field emission scanning electron microscope was applied to examine the microstructure of the resulting TBCs. The results showed that the TBCs exhibited a unique, complex structure including nonmelted or partially melted nanosized particles and columnar grains. A CO2 continuous wave laser beam has been applied to laser glaze the nanostructured zirconia TBCs. The effect of laser energy density on the microstructure and thermal shock resistance of the as-glazed coatings has been systematically investigated. SEM observation indicated that the microstructure of the as-glazed coatings was very different from the microstructure of the as-sprayed nanostructured TBCs. It changed from single columnar grain to a combination of columnar grains in the fracture surface and equiaxed grains on the surface with increasing laser energy density. Thermal shock resistance tests have showed that laser glazing can double the lifetime of TBCs. The failure of the as-glazed coatings was mainly due to the thermal stress caused by the thermal expansion coefficient mismatch between the ceramic coat and metallic substrate.

Liquid-phase chromatography detector

DOEpatents

Voigtman, Edward G.; Winefordner, James D.; Jurgensen, Arthur R.

1983-01-01

A liquid-phase chromatography detector comprising a flow cell having an inlet tubular conduit for receiving a liquid chromatographic effluent and discharging it as a flowing columnar stream onto a vertically adjustable receiving surface spaced apart from and located vertically below and in close proximity to the discharge end of the tubular conduit; a receiver adapted to receive liquid overflowing from the receiving surface; an exit conduit for continuously removing liquid from the receiver; a light source for focussing fluorescence-producing light pulses on the flowing columnar stream as it passes from the outlet of the conduit to the receiving surface and a fluorescence detector to detect the produced fluorescence; a source of light pulse for producing acoustic waves in the columnar stream as it passes from the conduit outlet to the receiving surface; and a piezoelectric transducer adapted to detect those waves; and a source of bias voltage applied to the inlet tubular conduit and adapted to produce ionization of the liquid flowing through the flow cell so as to produce photocurrents therein and an electrical system to detect and record the photocurrents. This system is useful in separating and detecting individual chemical compounds from mixtures thereof.

Stable Isotopic Variations in Columnar Cacti: are Responses to Climate Recorded in Spines?

NASA Astrophysics Data System (ADS)

English, N. B.; Dettman, D. L.; Williams, D. G.

2004-12-01

The behavior of the North American monsoon (NAM), particularly with respect to times of continental drought and its relationship to the Pacific-North American (PNA) teleconnection pattern and the El Nino/Southern Oscillation (ENSO) is of great interest to paleoclimatologists and water managers. Long-term instrumental precipitation and tree ring records in the southwestern United States and northwestern Mexico at low elevations are sparse and this has hindered research on NAM variability at interannual timescales. Saguaro cacti (Carnegiea gigantea) and other columnar cacti in North and South America are long-lived and have the potential to record climate variability on land with high temporal and spatial resolution. The vertical sequence of spines on the saguaro's exterior represents a high resolution (4 to 6 per year), and long (over 150 years) record of environmental change. We present results from an experiment where we tracked the oxygen isotopic values in the source waters, stem tissue waters and spine tissue for three treatments over the course of three months. These data are then compared to a previously developed mechanistic model of isotopic variation that reflects the physiological responses of Saguaro to climate variation over seasonal to century long time-scales. We also present the rationale for a new method to determine the growth rate of columnar cacti using the radiocarbon bomb spike. Our measurements reveal that oxygen and hydrogen isotopic variation among the sequentially produced and persistent spines covering the saguaro body record fluctuations in saguaro water balance. The model successfully predicts isotopic variation in spines and constrains controlling variables, yielding a powerful and high-resolution stable isotope index of water stress in the low desert. The development and refinement of an isotopic model for saguaro will serve as the basis for models applied to other species of columnar cacti in North and South America. The role of the tropics in global climate change is poorly understood and precise chronologies of tropical climate change are needed to place empirical constraints on competing theories and models. In particular, the use of continental records from columnar cacti in South America could identify ENSO periods in the last century and provide empirical constraints on the inputs of Atlantic (monsoonal) versus Pacific (winter) moisture to the Altiplano during ENSO and other important climatological phenomena.

Fundamental Characterization of the Micellar Self-Assembly of Sophorolipid Esters.

PubMed

Koh, Amanda; Todd, Katherine; Sherbourne, Ezekiel; Gross, Richard A

2017-06-13

Surfactants are ubiquitous constituents of commercial and biological systems that function based on complex structure-dependent interactions. Sophorolipid (SL) n-alkyl esters (SL-esters) comprise a group of modified naturally derived glycolipids from Candida bombicola. Herein, micellar self-assembly behavior as a function of SL-ester chain length was studied. Surface tensions as low as 31.2 mN/m and critical micelle concentrations (CMCs) as low as 1.1 μM were attained for diacetylated SL-decyl ester (dASL-DE) and SL-octyl ester, respectively. For deacetylated SL-esters, CMC values reach a lower limit at SL-ester chains above n-butyl (SL-BE, 1-3 μM). This behavior of SL-esters with increasing hydrophobic tail length is unlike other known surfactants. Diffusion-ordered spectroscopy (DOSY) and T 1 relaxation NMR experiments indicate this behavior is due to a change in intramolecular interactions, which impedes the self-assembly of SL-esters with chain lengths above SL-BE. This hypothesis is supported by micellar thermodynamics where a disruption in trends occurs at n-alkyl ester chain lengths above those of SL-BE and SL-hexyl ester (SL-HE). Diacetylated (dA) SL-esters exhibit an even more unusual trend in that CMC increases from 1.75 to 815 μM for SL-ester chain lengths of dASL-BE and dASL-DE, respectively. Foaming studies, performed to reveal the macroscopic implications of SL-ester micellar behavior, show that the observed instability in foams formed using SL-esters are due to coalescence, which highlights the importance of understanding intermicellar interactions. This work reveals that SL-esters are an important new family of green high-performing surfactants with unique structure-property relationships that can be tuned to optimize micellar characteristics.

Magnesium oxide prepared via metal-chitosan complexation method: Application as catalyst for transesterification of soybean oil and catalyst deactivation studies

NASA Astrophysics Data System (ADS)

Almerindo, Gizelle I.; Probst, Luiz F. D.; Campos, Carlos E. M.; de Almeida, Rusiene M.; Meneghetti, Simoni M. P.; Meneghetti, Mario R.; Clacens, Jean-Marc; Fajardo, Humberto V.

2011-10-01

A simple method to prepare magnesium oxide catalysts for biodiesel production by transesterification reaction of soybean oil with ethanol is proposed. The method was developed using a metal-chitosan complex. Compared to the commercial oxide, the proposed catalysts displayed higher surface area and basicity values, leading to higher yield in terms of fatty acid ethyl esters (biodiesel). The deactivation of the catalyst due to contact with CO2 and H2O present in the ambient air was verified. It was confirmed that the active catalytic site is a hydrogenocarbonate adsorption site.

Antileishmanial activity of the hydroalcoholic extract of Miconia langsdorffii, isolated compounds, and semi-synthetic derivatives.

PubMed

Peixoto, Juliana A; Andrade E Silva, Márcio Luis; Crotti, Antônio E M; Cassio Sola Veneziani, Rodrigo; Gimenez, Valéria M M; Januário, Ana H; Groppo, Milton; Magalhães, Lizandra G; Dos Santos, Fransérgio F; Albuquerque, Sérgio; da Silva Filho, Ademar A; Cunha, Wilson R

2011-02-22

The in vitro activity of the crude hydroalcoholic extract of the aerial parts of Miconia langsdorffii Cogn. was evaluated against the promastigote forms of L. amazonensis, the causative agent of cutaneous leishmaniasis in humans. The bioassay-guided fractionation of this extract led to identification of the triterpenes ursolic acid and oleanolic acid as the major compounds in the fraction that displayed the highest activity. Several ursolic acid semi-synthetic derivatives were prepared, to find out whether more active compounds could be obtained. Among these ursolic acid-derived substances, the C-28 methyl ester derivative exhibited the best antileishmanial activity.

Parallel human genome analysis: microarray-based expression monitoring of 1000 genes.

PubMed Central

Schena, M; Shalon, D; Heller, R; Chai, A; Brown, P O; Davis, R W

1996-01-01

Microarrays containing 1046 human cDNAs of unknown sequence were printed on glass with high-speed robotics. These 1.0-cm2 DNA "chips" were used to quantitatively monitor differential expression of the cognate human genes using a highly sensitive two-color hybridization assay. Array elements that displayed differential expression patterns under given experimental conditions were characterized by sequencing. The identification of known and novel heat shock and phorbol ester-regulated genes in human T cells demonstrates the sensitivity of the assay. Parallel gene analysis with microarrays provides a rapid and efficient method for large-scale human gene discovery. Images Fig. 1 Fig. 2 Fig. 3 PMID:8855227

[Development of gas chromatography-mass spectrometry for determination of fatty acid esters of chloropropanols in milk powder and the pollution level of infant formula].

PubMed

Li, Shan; Miao, Hong; Cui, Xia; Zhao, Yunfeng; Wu, Yongning

2015-06-01

To establish a method for determination of fatty acid esters of chloropropanols (chloropropanols esters) in milk powder by isotope dilution-gas chromatography-mass spectrometry (GC-MS), and to acquire the pollution level of chloropropanols esters in infant formula and evaluate the dietary exposure risk of chloropropanols esters in infant formula for infants. A total of 111 infant formula samples were collected from supermarkets in Beijing, and the infant formula with no chloropropanols esters detected was served as the blank sample. The samples were ultrasonically extracted with hexane, followed by ester-bond cleavage reaction with sodium methylate-methanol and purification by matrix solid-supported liquid-liquid extraction, then being derivatived with heptafluoro butyrylimidazol. After extracted by sodium chloride solution, the derivatives were determined by GC-MS. The concentration of chloropropanols esters were quantified using the deuterium chloropropanols esters as the internal standards. The accuracy of the method was assessed by the recoveries of the blank spiked samples, and the relative standard deviations (RSD) of the recoveries represent the precision of the method. The contamination level of chloropropanols esters and the intake amount of the infant formula of the 6-month infant were used to estimate the dietary exposure assessment, and x (95% CI) and P97.5 of the contamination level of chloropropanols esters were used to represent the average dietary exposure and the high-end dietary exposure. The satisfied linear correlations in the range of 0.010-0.800 mg/L was acquired for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters with coefficient correlations of 0.999 9, 0.999 8, 0.999 5 and 0.999 6, respectively. The limits of detection (LOD) and the limits of quantitation (LOQ) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0.005, 0.005, 0.015, 0.015 mg/kg, and 0.015, 0.015, 0.045, 0.045 mg/kg. The average recoveries of the four chloropropanols esters spiked at 0.025, 0.050 and 0.100 mg/kg in blank matrix were in a range from 80.3% to 111.9%, with relative standard deviations (RSD) less than 11.4%. Of the 111 infant formula samples, the detection rates and the contamination levels of 3-MCPD esters and 2-MCPD esters were 77.5% (86/111), 11.7% (13/111) with the contamination levels in the range of ND-0.230 mg/kg and ND-0.039 mg/kg, respectively, and χ (95% CI) and P97.5 of 3-MCPD esters and 2-MCPD esters were 0.020 (0.003-0.113) and 0.006 (0.005-0.025) mg/kg, 0.113 and 0.025 mg/kg, respectively. 1,3-DCP esters and 2,3-DCP esters were not detected in the 111 samples. x (95% CI) and P75 of the six-month old infants to 3-MCPD esters were 0.304 (0.038-1.735) and 1.735 µg · kg⁻¹ · d⁻¹, respectively, which accounted for 15.2% and 86.7% of the PMTDI (2 µg · kg⁻¹ · d⁻¹) of 3-MCPD. This GC-MS method was accurate and rugged for the determination of chloropropanols esters in milk powder. Based on the exposure assessment results, the health risk of chloropropanols esters for infants caused by the intake of infant formula was acceptable.

Mumijo Traditional Medicine: Fossil Deposits from Antarctica (Chemical Composition and Beneficial Bioactivity)

PubMed Central

Aiello, Anna; Fattorusso, Ernesto; Menna, Marialuisa; Vitalone, Rocco; Schröder, Heinz C.; Müller, Werner E. G.

2011-01-01

Mumijo is a widely used traditional medicine, especially in Russia, Altai Mountains, Mongolia, Iran Kasachstan and in Kirgistan. Mumijo preparations have been successfully used for the prevention and treatment of infectious diseases; they display immune-stimulating and antiallergic activity as well. In the present study, we investigate the chemical composition and the biomedical potential of a Mumijo(-related) product collected from the Antarctica. The yellow material originates from the snow petrels, Pagodroma nivea. Extensive purification and chemical analysis revealed that the fossil samples are a mixture of glycerol derivatives. In vitro experiments showed that the Mumijo extract caused in cortical neurons a strong neuroprotective effect against the apoptosis-inducing amyloid peptide fragment β-fragment 25–35 (Aβ25–35). In addition, the fraction rich in glycerol ethers/wax esters displayed a significant growth-promoting activity in permanent neuronal PC12 cells. It is concluded that this new Mumijo preparation has distinct and marked neuroprotective activity, very likely due to the content of glycerol ether derivatives. PMID:18996940

Direct Determination of MCPD Fatty Acid Esters and Glycidyl Fatty Acid Esters in Vegetable Oils by LC–TOFMS

PubMed Central

Haines, Troy D.; Adlaf, Kevin J.; Pierceall, Robert M.; Lee, Inmok; Venkitasubramanian, Padmesh

2010-01-01

Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable oils. The results of the LC–TOFMS method were compared with the DGF method. The DGF method consistently gave results that were greater than the LC–TOFMS method. The levels of MCPD esters and glycidyl esters found in a variety of vegetable oils are reported. MCPD monoesters were not found in any oil samples. MCPD diesters were found only in samples containing palm oil, and were not present in all palm oil samples. Glycidyl esters were found in a wide variety of oils. Some processing conditions that influence the concentration of MCPD esters and glycidyl esters are discussed. PMID:21350591

Wax ester profiling of seed oil by nano-electrospray ionization tandem mass spectrometry

PubMed Central

2013-01-01

Background Wax esters are highly hydrophobic neutral lipids that are major constituents of the cutin and suberin layer. Moreover they have favorable properties as a commodity for industrial applications. Through transgenic expression of wax ester biosynthetic genes in oilseed crops, it is possible to achieve high level accumulation of defined wax ester compositions within the seed oil to provide a sustainable source for such high value lipids. The fatty alcohol moiety of the wax esters is formed from plant-endogenous acyl-CoAs by the action of fatty acyl reductases (FAR). In a second step the fatty alcohol is condensed with acyl-CoA by a wax synthase (WS) to form a wax ester. In order to evaluate the specificity of wax ester biosynthesis, analytical methods are needed that provide detailed wax ester profiles from complex lipid extracts. Results We present a direct infusion ESI-tandem MS method that allows the semi-quantitative determination of wax ester compositions from complex lipid mixtures covering 784 even chain molecular species. The definition of calibration prototype groups that combine wax esters according to their fragmentation behavior enables fast quantitative analysis by applying multiple reaction monitoring. This provides a tool to analyze wax layer composition or determine whether seeds accumulate a desired wax ester profile. Besides the profiling method, we provide general information on wax ester analysis by the systematic definition of wax ester prototypes according to their collision-induced dissociation spectra. We applied the developed method for wax ester profiling of the well characterized jojoba seed oil and compared the profile with wax ester-accumulating Arabidopsis thaliana expressing the wax ester biosynthetic genes MaFAR and ScWS. Conclusions We developed a fast profiling method for wax ester analysis on the molecular species level. This method is suitable to screen large numbers of transgenic plants as well as other wax ester samples like cuticular lipid extracts to gain an overview on the molecular species composition. We confirm previous results from APCI-MS and GC-MS analysis, which showed that fragmentation patterns are highly dependent on the double bond distribution between the fatty alcohol and the fatty acid part of the wax ester. PMID:23829499

Methods of refining and producing dibasic esters and acids from natural oil feedstocks

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

Snead, Thomas E; Cohen, Steven A; Gildon, Demond L

2015-04-07

Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

Methods of refining and producing dibasic esters and acids from natural oil feedstocks

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

Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

2016-03-15

Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

Comparative analysis of fruit aroma patterns in the domesticated wild strawberries “Profumata di Tortona” (F. moschata) and “Regina delle Valli” (F. vesca)

PubMed Central

Negri, Alfredo S.; Allegra, Domenico; Simoni, Laura; Rusconi, Fabio; Tonelli, Chiara; Espen, Luca; Galbiati, Massimo

2015-01-01

Strawberry is one of the most valued fruit worldwide. Modern cultivated varieties (Fragaria × ananassa) exhibit large fruits, with intense color and prolonged shell life. Yet, these valuable traits were attained at the cost of the intensity and the variety of the aroma of the berry, two characteristics highly appreciated by consumers. Wild species display smaller fruits and reduced yield compared with cultivated varieties but they accumulate broader and augmented blends of volatile compounds. Because of the large diversity and strength of aromas occurring in natural and domesticated populations, plant breeders regard wild strawberries as important donors of novel scented molecules. Here we report a comprehensive metabolic map of the aroma of the wild strawberry Profumata di Tortona (PdT), an ancient clone of F. moschata, considered as one of the most fragrant strawberry types of all. Comparison with the more renowned woodland strawberry Regina delle Valli (RdV), an aromatic cultivar of F. vesca, revealed a significant enrichment in the total level of esters, alcohols and furanones and a reduction in the content of ketones in in the aroma of PdT berries. Among esters, particularly relevant was the enhanced accumulation of methyl anthranilate, responsible for the intensive sweetish impression of wild strawberries. Interestingly, increased ester accumulation in PdT fruits correlated with enhanced expression of the Strawberry Alcohol Acyltransferase (SAAT) gene, a key regulator of flavor biogenesis in ripening berries. We also detected a remarkable 900-fold increase in the level of mesifurane, the furanone conferring the typical caramel notes to most wild species. PMID:25717332

Lipophilicity plays a major role in modulating the inhibition of monoamine oxidase B by 7-substituted coumarins.

PubMed

Carotti, Angelo; Altomare, Cosimo; Catto, Marco; Gnerre, Carmela; Summo, Luciana; De Marco, Agostino; Rose, Sarah; Jenner, Peter; Testa, Bernard

2006-02-01

A series of coumarin derivatives (1-22), bearing at the 7-position ether, ketone, ester, carbamate, or amide functions of varying size and lipophilicity, were synthesized and investigated for their in vitro monoamine oxidase-A and -B (MAO-A and -B) inhibitory activities. Most of the compounds acted preferentially as MAO-B inhibitors, with IC(50) values in the micromolar to low-nanomolar range. A structure-activity-relationship (SAR) study highlighted lipophilicity as an important property modulating the MAO-B inhibition potency of 7-substituted coumarins, as shown by a linear correlation (n=20, r(2)=0.72) between pIC(50) and calculated log P values. The stability of ester-containing coumarin derivatives in rat plasma provided information on factors that either favor (lipophilicity) or decrease (steric hindrance) esterase-catalyzed hydrolysis. Two compounds (14 and 22) were selected to investigate how lipophilicity and enzymatic stability may affect in vivo MAO activities, as assayed ex vivo in rat. The most-potent and -selective MAO-B inhibitor 22 (=7-[(3,4-difluorobenzyl)oxy]-3,4-dimethyl-1-benzopyran-2(2H)-one) within the examined series significantly inhibited (>60%) ex vivo rat-liver and striatal MAO-B activities 1 h after intraperitoneal administration of high doses (100 and 300 mumol kg(-1)), revealing its ability to cross the blood-brain barrier. At the same doses, liver and striatum MAO-A was less inhibited in vivo, somehow reflecting MAO-B selectivity, as assessed in vitro. In contrast, the metabolically less stable derivative 14, bearing an isopropyl ester in the lateral chain, had a weak effect on hepatic MAO-B activity in vivo, and none on striatal MAO-B, but, surprisingly, displayed inhibitory effects on MAO-A in both peripheral and brain tissues.

Impact of three phthalate esters on the sexual reproduction of the Monogonont rotifer, Brachionus calyciflorus.

PubMed

Cruciani, V; Iovine, C; Thomé, J-P; Joaquim-Justo, C

2016-01-01

Phthalate esters are widespread contaminants that can cause endocrine disruption in vertebrates. Studies showed that molecules with hormonal activities in vertebrates and invertebrates can affect asexual and sexual reproduction in rotifers. We investigated the impact of di-hexylethyl phthalate (DEHP), di-butyl phthalate (DBP) and butylbenzyl phthalate (BBP), on the asexual and sexual reproduction of the freshwater monogonont rotifer Brachionus calyciflorus in order to determine a potential environmental risk for sexual reproduction. We observed that DEHP has no significant impact on both asexual and sexual reproduction up to 2 mg/L. DBP has a positive effect on asexual reproduction at concentrations from 0.05 to 1 mg/L, but depresses it at 2 mg/L. Sexual reproduction is only affected at 2 mg/L and the impact observed is negative. BBP displayed a negative impact on both asexual and sexual reproduction at 1 and 2 mg/L. However we showed that the impacts of BBP on mixis and fertilization rates observed are due to the decrease in population growth rates at these concentrations and not to a direct impact of BBP on the mixis and the fertilization processes. Our results show that sexual reproduction in B. calyciflorus is not more sensitive than asexual reproduction to any of the substances tested which indicates the mode of action of these molecules is related to general toxicity and not to an interference with potential endocrine regulation of sexual reproduction. Comparison of effect concentrations and surface water contamination by phthalate esters suggests these compounds do not constitute a risk for primary consumers in these environments.

Fermentative behavior of Saccharomyces strains during microvinification of raspberry juice (Rubus idaeus L.).

PubMed

Duarte, Whasley F; Dragone, Giuliano; Dias, Disney R; Oliveira, José M; Teixeira, José A; Silva, João B Almeida E; Schwan, Rosane F

2010-10-15

Sixteen different strains of Saccharomyces cerevisiae and Saccharomyces bayanus were evaluated in the production of raspberry fruit wine. Raspberry juice sugar concentrations were adjusted to 16° Brix with a sucrose solution, and batch fermentations were performed at 22 °C. Various kinetic parameters, such as the conversion factors of the substrates into ethanol (Y(p/s)), biomass (Y(x/s)), glycerol (Y(g/s)) and acetic acid (Y(ac/s)), the volumetric productivity of ethanol (Q(p)), the biomass productivity (P(x)), and the fermentation efficiency (E(f)) were calculated. Volatile compounds (alcohols, ethyl esters, acetates of higher alcohols and volatile fatty acids) were determined by gas chromatography (GC-FID). The highest values for the E(f), Y(p/s), Y(g/s), and Y(x/s) parameters were obtained when strains commonly used in the fuel ethanol industry (S. cerevisiae PE-2, BG, SA, CAT-1, and VR-1) were used to ferment raspberry juice. S. cerevisiae strain UFLA FW 15, isolated from fruit, displayed similar results. Twenty-one volatile compounds were identified in raspberry wines. The highest concentrations of total volatile compounds were found in wines produced with S. cerevisiae strains UFLA FW 15 (87,435 μg/L), CAT-1 (80,317.01 μg/L), VR-1 (67,573.99 μg/L) and S. bayanus CBS 1505 (71,660.32 μg/L). The highest concentrations of ethyl esters were 454.33 μg/L, 440.33 μg/L and 438 μg/L for S. cerevisiae strains UFLA FW 15, VR-1 and BG, respectively. Similar to concentrations of ethyl esters, the highest concentrations of acetates (1927.67 μg/L) and higher alcohols (83,996.33 μg/L) were produced in raspberry wine from S. cerevisiae UFLA FW 15. The maximum concentration of volatile fatty acids was found in raspberry wine produced by S. cerevisiae strain VR-1. We conclude that S. cerevisiae strain UFLA FW 15 fermented raspberry juice and produced a fruit wine with low concentrations of acids and high concentrations of acetates, higher alcohols and ethyl esters. Copyright © 2010 Elsevier B.V. All rights reserved.

The development and characterization of degradable poly(vinyl ester) and poly(vinyl ester)/PEO block copolymers

NASA Astrophysics Data System (ADS)

Lipscomb, Corinne Elizabeth

The development of biodegradable materials is a challenging and important problem in polymer science. A review of the state of the art in degradable materials is presented, which reveals that current biodegradable materials do not exhibit the thermal or mechanical properties necessary for widespread applications. One strategy for toughening polymeric materials, which has previously been applied to non-degradable thermoplastics and thermoplastic elastomers, is the formation of block copolymers. Poly(vinyl esters) (PVE) homopolymers are known to have a wide range of properties, but PVE block copolymers comprise a class of inexpensive and (bio)degradable materials that were previously unknown. Therefore, the synthesis and properties of these block copolymers were explored in an effort to develop robust degradable materials. This thesis research probes the reaction conditions necessary for the reversible-addition fragmentation chain transfer (RAFT) polymerization and chain extension reactions of vinyl ester monomers. PVE di- and triblock copolymers are synthesized and studied, and the triblock copolymers display extremely poor toughness due to their relatively low molecular weights in light of the high entanglement molecular weight of the poly(vinyl acetate) center block. Attempts to improve the mechanical properties of these materials focus on the incorporation of poly(ethylene oxide) (PEO) as a low entanglement molecular weight and biocompatible center block in PVE-containing triblock copolymers. Depending on the choice of PVE endblocks and the overall polymer composition, crystallization of the PEO block can be controlled, confined, or inhibited. Polymers in which PEO crystallization is completely inhibited exhibit enhanced mechanical properties and behave as weak thermoplastics. In order to understand the relationship between the inhibition of PEO crystallization and the mechanical properties of PVE/PEO materials, these polymers were studied using dynamic mechanical spectroscopy, wide angle X-ray scattering, small angle X-ray scattering, differential scanning calorimetry, and uniaxial tensile tests. By combining insights gained from these techniques, a complex picture emerges that explains the enhanced mechanical properties of these materials based on the type and location of thermal transitions, amorphous PEO entanglements, and the strain-induced crystallization of PEO. This work represents an important step toward developing robust materials with tunable properties containing (bio)degradable components.

Synthesis and characterization of cadmium-calcium hydroxyapatite solid solutions

NASA Astrophysics Data System (ADS)

Zhao, Xin; Zhu, Yi-nian; Dai, Liu-qin

2014-06-01

A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges of Cd/(Cd+Ca) atomic ratio. In the results, both lattice parameters a and c display slight deviations from Vegard's rule when the Cd/(Cd+Ca) atomic ratio is greater than 0.6. The particles change from smaller acicular to larger hexagonal columnar crystals as the Cd/(Cd+Ca) atomic ratio increases from 0-0.60 to 0.60-1.00. The area of the phosphate peak for symmetric P-O stretching decreases with the increase in Cd/(Cd+Ca) atomic ratio, and the peak disappears when the Cd/(Cd+Ca) atomic ratio is greater than 0.6; the two phosphate peaks of P-O stretching gradually merge together for the Cd/(Cd+Ca) atomic ratio near 0.60. These variations can be explained by a slight tendency of larger Cd ions to occupy M(2) sites and smaller Ca ions to prefer M(1) sites in the structure.

NASA combined file postings statistics based on NASA thesaurus, Jan. 1968 - July 1988

NASA Technical Reports Server (NTRS)

1988-01-01

The NASA Combined File Postings Statistics is published semiannually (January and July). This alphabetical listing of postable subject terms contained in the NASA Thesaurus is used to display the numbers of postings (documents) indexed by each subject term from 1968 to date. The postings total per term are separated by announcement or other media into STAR, IAA, NLN, and OTHER columnar entries covering the NASA document collection (1968 to date). Nearly 594,000 book postings for NALNET Books held by NASA libraries are now included under the NLN column. CSTAR postings as well as some previously unreported series are now listed under the other column. File postings statistics for the Alternate Data Base covering the NASA collection from 1962 through 1967 were published on a one-time basis in September 1975. Subject terms for the Alternate Data Base are derived from the Subject Authority List, reprinted in 1985, which is available on request. The distribution of 16,919,195 postings among the 17,105 Thesaurus terms is tabulated on the last page of Combined File Postings Statistics.

NASA thesaurus combined file postings statistics

NASA Technical Reports Server (NTRS)

1993-01-01

The NASA Thesaurus Combined File Postings Statistics is published semiannually (January and July). This alphabetical listing of postable subject terms contained in the NASA Thesaurus is used to display the number of postings (documents) indexed by each subject term from 1968 to date. The postings totals per item are separated by announcement of other media into STAR, IAA, COSMIC, and OTHER, columnar entries covering the NASA document collection (1968 to date). This is a cumulative publication, and except for special cases, no reference is needed to previous issuances. Retention of the January 1992 issue could be helpful for book information. With the July 1992 issue, NALNET book statistics have been replaced by COSMIC statistics for NASA funded software. File postings statistics for the Alternate Data Base covering NASA collection from 1962 through 1967 were published on a one-time basis in September 1975. Subject terms for the Alternate Data Base are derived from the subject Authority List, reprinted 1985, which is available upon request. The distribution of 19,697,748 postings among the 17,446 NASA Thesaurus terms is tabulated on the last page of the NASA Thesaurus Combined File Postings Statistics.

Chlamydia trachomatis Is Responsible for Lipid Vacuolation in the Amniotic Epithelium of Fetal Gastroschisis.

PubMed

Feldkamp, Marcia L; Ward, Diane M; Pysher, Theodore J; Chambers, Christina T

2017-07-17

Vacuolated amniotic epithelium with lipid droplets in gastroschisis placentas is an unusual finding. Mass spectrometry of lipid droplets identified triglycerides, ester-linked to an unusual pattern of fatty acids. We hypothesize that these findings result from a Chlamydia trachomatis infection during the periconceptional period. The rising incidence of chlamydia infections has paralleled the increasing prevalence of gastroschisis among women less than 25 years of age. Histologically, young women are at greatest risk for a chlamydia infection due to their immature columnar epithelium, the preferential site for attachment of Chlamydia trachomatis infectious particle (elementary body). Chlamydia trachomatis survive in an inclusion, relying on its host to acquire essential nutrients, amino acids, and nucleotides for survival and replication. If essential nutrients are not available, the bacteria cannot replicate and may be trafficked to the lysosome for degradation or remain quiescent, within the inclusion, subverting innate immunologic clearance. Chlamydiae synthesize several lipids (phosphatidylethanolamine, phosphatidylserine, and phosphoatidylglycerol); however, their lipid content reveal eukaryotic lipids (sphingomyelin, cholesterol, phosphatidylcholine, and phosphatidylinositol), evidence that chlamydiae "hijack" host lipids for expansion and replication. The abnormal amniotic epithelial findings are supported by experimental evidence of the trafficking of host lipids into the chlamydiae inclusion. If not lethal, what harm will elementary bodies inflict to the developing embryo? Do these women have a greater pro-inflammatory response to an environmental exposure, whether cigarette smoking, change in partner, or a pathogen? Testing the hypothesis that Chlamydia trachomatis is responsible for amniotic epithelium vacuoles will be a critical first step. Birth Defects Research 109:1003-1010, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Analysis of the Properties of the Esters of Neopentyl Glycol,

DTIC Science & Technology

The esters of neopentyl glycol and monocarboxylic acids of normal and isomeric structure were synthesized. The esters are characterized by higher...indices of viscosity and solidification temperatures than the esters of the acids of isomeric structure. The esters of neopentyl glycol and industrial

Palladium-Catalyzed α-Arylation of Zinc Enolates of Esters: Reaction Conditions and Substrate Scope

PubMed Central

Hama, Takuo; Ge, Shaozhong; Hartwig, John F.

2013-01-01

The intermolecular α-arylation of esters by palladium-catalyzed coupling of aryl bromides with zinc enolates of esters is reported. Reactions of three different types of zinc enolates have been developed. α-Arylation of esters occurs in high yields with isolated Reformatsky reagents, with Reformatsky reagents generated from α-bromo esters and activated zinc, and with zinc enolates generated by quenching lithium enolates of esters with zinc chloride. The use of zinc enolates, instead of alkali metal enolates, greatly expands the scope of the arylation of esters. The reactions occur at room temperature or at 70 °C with bromoarenes containing cyano, nitro, ester, keto, fluoro, enolizable hydrogen, hydroxyl or amino functionality and with bromopyridines. The scope of esters encompasses acyclic acetates, propionates, and isobutyrates, α-alkoxyesters, and lactones. The arylation of zinc enolates of esters was conducted with catalysts bearing the hindered pentaphenylferrocenyl di-tert-butylphosphine (Q-phos) or the highly reactive dimeric Pd(I) complex {[P(t-Bu)3]PdBr}2. PMID:23931445

Comparative study of the antioxidant activities of some lipase-catalyzed alkyl dihydrocaffeates synthesized in ionic liquid.

PubMed

Gholivand, Somayeh; Lasekan, Ola; Tan, Chin Ping; Abas, Faridah; Wei, Leong Sze

2017-06-01

The solubility limitations of phenolic acids in many lipidic environments are now greatly improved by their enzymatic esterification in ionic liquids (ILs). Herein, four different ILs were tested for the esterification of dihydrocaffeic acid with hexanol and the best IL was selected for the synthesis of four other n-alkyl esters with different chain-lengths. The effect of alkyl chain length on the anti-oxidative properties of the resulted purified esters was investigated using β-carotene bleaching (BCB) and free radical scavenging method DPPH and compared with butylated hydroxytoluene (BHT) as reference compound. All four esters (methyl, hexyl, dodecyl and octadecyl dihydrocaffeates) exhibited relatively strong radical scavenging abilities. The scavenging activity of the test compounds was in the following order: methyl ester>hexyl ester⩾dodecyl ester>octadecyl ester>BHT while the order for the BCB anti-oxidative activity was; BHT>octadecyl ester>dodecyl ester>hexyl ester>methyl ester. Copyright © 2016 Elsevier Ltd. All rights reserved.

Large effect of columnar defects on the thermodynamic properties of Bi2Sr2CaCu2O8 single crystals

NASA Astrophysics Data System (ADS)

van der Beek, C. J.; Konczykowski, M.; Li, T. W.; Kes, P. H.; Benoit, W.

1996-07-01

The introduction of columnar defects by irradiation with 5.8-GeV Pb ions is shown to affect significantly the reversible magnetic properties of Bi2Sr2CaCu2O8+δ single crystals. Notably, the suppression of superconducting fluctuations on length scales greater than the separation between columns leads to the disappearance of the ``crossing point'' in the critical fluctuation regime. At lower temperatures, the strong modification of the vortex energy due to pinning leads to an important change of the reversible magnetization. The analysis of the latter permits the direct determination of the pinning energy.

["Vestigial cells" of the transitional area of the uterine-cervix. Comparative morphological study with the subcylindrical-reserve-cells (author's transl)].

PubMed

Minh, H N; Smadja, A; Lecomte, D; Orcel, L; Coupez, F

1982-01-01

The squamo-cylindrical junction represents a transitional area of unstable epithelium. It consists of slightly differentiated cells which disclosed resemblance in morphological pattern with germinal cells of the basal layer in the exocervical squamous epithelium. These unstable cells, according to the authors, may be derived from the cranial, most cephalic extend of the sinusal vaginal plate which had formed the epithelium of the entire vagina and the vaginal portion of the cervix up to the squamo-columnar junction. Ultrastructural analysis disclosed no similarities between cells of the squamo-columnar junction and subcylindrical reserve cells which exhibited sometimes resemblance to the "mesenchymal cells" found within the surrounding stroma.

Morphology-Dependent Hardness of Cr7C3-Ni-Rich Alloy Composite vs Orientation Independent Hardness of Cr7C3 Primary Phase in a Laser Clad Microstructure

NASA Astrophysics Data System (ADS)

Venkatesh, Lakshmi Narayanan; Suresh Babu, Pitchuka; Gundakaram, Ravi Chandra; Doherty, Roger D.; Joshi, Shrikant V.; Samajdar, Indradev

2017-04-01

Microstructural evolution with superheating was studied in chromium carbide-nickel coatings deposited by laser cladding. At lower superheating, selective growth of <0001> direction from the high density of Cr7C3 grains nucleated resulted in a columnar structure with (0001) texture. Increased superheating lead to the loss of columnar structure as well as the (0001) texture. The hexagonal Cr7C3 showed an unusual isotropic nanoindentation hardness evidently correlated with its low c/ a ratio. However, the rod-like morphology of the carbide dendrites resulted in significant anisotropy in the hardness of the composite.

21 CFR 172.854 - Polyglycerol esters of fatty acids.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyglycerol esters of fatty acids. 172.854... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including the decaglycerol esters, may be safely used in food in...

Variability of some diterpene esters in coffee beverages as influenced by brewing procedures.

PubMed

Moeenfard, Marzieh; Erny, Guillaume L; Alves, Arminda

2016-11-01

Several coffee brews, including classical and commercial beverages, were analyzed for their diterpene esters content (cafestol and kahweol linoleate, oleate, palmitate and stearate) by high performance liquid chromatography with diode array detector (HPLC-DAD) combined with spectral deconvolution. Due to the coelution of cafestol and kahweol esters at 225 nm, HPLC-DAD did not give accurate quantification of cafestol esters. Accordingly, spectral deconvolution was used to deconvolve the co-migrating profiles. Total cafestol and kahweol esters content of classical coffee brews ranged from 5-232 to 2-1016 mg/L, respectively. Commercial blends contained 1-54 mg/L of total cafestol esters and 2-403 mg/L of total kahweol esters. Boiled coffee had the highest diterpene esters content, while filtered and instant brews showed the lowest concentrations. However, individual diterpene esters content was not affected by brewing procedure as in terms of kahweol esters, kahweol palmitate was the main compound in all samples, followed by kahweol linoleate, oleate and stearate. Higher amounts of cafestol palmitate and stearate were also observed compared to cafestol linoleate and cafestol oleate. The ratio of diterpene esters esterified with unsaturated fatty acids to total diterpene esters was considered as measure of their unsaturation in analyzed samples which varied from 47 to 52%. Providing new information regarding the diterpene esters content and their distribution in coffee brews will allow a better use of coffee as a functional beverage.

Origin of estradiol fatty acid esters in human ovarian follicular fluid.

PubMed

Pahuja, S L; Kim, A H; Lee, G; Hochberg, R B

1995-03-01

The estradiol fatty acid esters are the most potent of the naturally occurring steroidal estrogens. These esters are present predominantly in fat, where they are sequestered until they are hydrolyzed by esterases. Thus they act as a preformed reservoir of estradiol. We have previously shown that ovarian follicular fluid from patients undergoing gonadotropin stimulation contains very high amounts of estradiol fatty acid esters (approximately 10(-7) M). The source of these esters is unknown. They can be formed by esterification of estradiol in the follicular fluid by lecithin:cholesterol acyltransferase (LCAT), or in the ovary by an acyl coenzyme A:acyltransferase. In order to determine which of these enzymatic processes is the source of the estradiol esters in the follicular fluid, we incubated [3H]estradiol with follicular fluid and cells isolated from human ovarian follicular fluid and characterized the fatty acid composition of the [3H]estradiol esters biosynthesized in each. In addition, we characterized the endogenous estradiol fatty acid esters in the follicular fluid and compared them to the biosynthetic esters. The fatty acid composition of the endogenous esters was different than those synthesized by the cellular acyl coenzyme A:acyltransferase, and the same as the esters synthesized by LCAT, demonstrating that the esters are produced in situ in the follicular fluid. Although the role of these estradiol esters in the ovary is not known, given their remarkable estrogenic potency it is highly probable that they have an important physiological role.

Palisade cell shape affects the light-induced chloroplast movements and leaf photosynthesis.

PubMed

Gotoh, Eiji; Suetsugu, Noriyuki; Higa, Takeshi; Matsushita, Tomonao; Tsukaya, Hirokazu; Wada, Masamitsu

2018-01-24

Leaf photosynthesis is regulated by multiple factors that help the plant to adapt to fluctuating light conditions. Leaves of sun-light-grown plants are thicker and contain more columnar palisade cells than those of shade-grown plants. Light-induced chloroplast movements are also essential for efficient leaf photosynthesis and facilitate efficient light utilization in leaf cells. Previous studies have demonstrated that leaves of most of the sun-grown plants exhibited no or very weak chloroplast movements and could accomplish efficient photosynthesis under strong light. To examine the relationship between palisade cell shape, chloroplast movement and distribution, and leaf photosynthesis, we used an Arabidopsis thaliana mutant, angustifolia (an), which has thick leaves that contain columnar palisade cells similar to those in the sun-grown plants. In the highly columnar cells of an mutant leaves, chloroplast movements were restricted. Nevertheless, under white light condition (at 120 µmol m -2 s -1 ), the an mutant plants showed higher chlorophyll content per unit leaf area and, thus, higher light absorption by the leaves than the wild type, which resulted in enhanced photosynthesis per unit leaf area. Our findings indicate that coordinated regulation of leaf cell shape and chloroplast movement according to the light conditions is pivotal for efficient leaf photosynthesis.

Study of the Formation Mechanism of A-Segregation Based on Microstructural Morphology

NASA Astrophysics Data System (ADS)

Zhang, Zhao; Bao, Yuchong; Liu, Lin; Pian, Song; Li, Ri

2018-04-01

A model that combines a cellular automaton (CA) and lattice Boltzmann method (LBM) is presented. The mechanism of A-segregation in an Fe-0.34 wt pct C alloy ingot is analyzed on the basis of microstructural morphology calculations. The CA is used to capture the solid/liquid interface, while the LBM is used to calculate the transport phenomena. (1) The solidification of global columnar dendrites was simulated, and two obvious A-segregation bands appeared in the middle-radius region between the ingot wall surface and the centerline. In addition, the angle of deflection to the centerline increased with the increasing heat dissipation rate of the wall surface. When natural convection was ignored, the A-segregation disappeared, and only positive segregation was present in the center and bottom corner of the ingot. (2) Mixed columnar-equiaxed solidification was simulated. Many A-segregation bands appeared in the ingot. (3) Global equiaxed solidification was simulated, and no A-segregation bands were found. The results show that the upward movement of the high-concentration melt is the key to the formation of A-segregation bands, and remelting and the emergence of equiaxed grains are not necessary conditions to develop these bands. However, the appearance of equiaxed grains accelerates the formation of vortexes; thus, many A-segregation bands appear during columnar-equiaxed solidification.

Wong-Type Dermatomyositis Showing Porokeratosis-Like Changes (Columnar Dyskeratosis): A Case Report and Review of the Literature

PubMed Central

Umanoff, Nicole; Fisher, Ari; Carlson, J. Andrew

2015-01-01

Background Wong-type dermatomyositis (DM) exhibits simultaneous pityriasis rubra pilaris (PRP) features. Case Report A 50-year-old woman presented with a heliotrope rash, Gottron's papules, and a poikilodermic, erythematous rash in shawl distribution without evidence of muscle weakness. Despite topical corticosteroids, the eruption progressed 9 months later to include generalized hyperkeratotic follicular papules, islands of sparing, and atrophic macules with a collarette of scale suggestive of porokeratosis. Mild dysphonia was the only sign of muscle weakness. Serology showed positive ANA. Histopathology revealed interface dermatitis with dermal mucin and melanophages, irregular psoriasiform hyperplasia, alternating mounds of para- and orthokeratosis, and tiers of dyskeratotic cells (columnar dyskeratosis). Systemic corticosteroid therapy was not tolerated; acitretin diminished the hyperkeratosis. While hyperpigmentation persisted, no progression of cutaneous or muscular symptoms has occurred after 22 months of follow-up and cessation of the therapy. Overall, her course did not differ from the natural history documented in the literature review of Wong-type DM. The most similar case also exhibited pseudocornoid lamella changes. Conclusion Wong-type DM is a clinicopathologic DM-PRP hybrid that can also exhibit porokeratosis-like features best described as columnar dyskeratosis. Recognizing these types of lesions in DM is warranted in order to make an accurate assessment of their prognostic significance. PMID:27047930

Structural and optical properties of glancing angle deposited In2O3 columnar arrays and Si/In2O3 photodetector

NASA Astrophysics Data System (ADS)

Mondal, A.; Shougaijam, B.; Goswami, T.; Dhar, J. C.; Singh, N. K.; Choudhury, S.; Chattopadhay, K. K.

2014-04-01

Ordered and perpendicular columnar arrays of In2O3 were synthesized on conducting ITO electrode by a simple glancing angle deposition (GLAD) technique. The as-deposited In2O3 columns were investigated by field emission gun-scanning electron microscope (FEG-SEM). The average length and diameter of the columns were estimated ˜400 nm and ˜100 nm, respectively. The morphology of the structure was examined by transmission electron microscopy (TEM). X-ray diffraction (XRD) analysis shows the polycrystalline nature of the sample which was verified by selective area electron diffraction (SAED) analysis. The growth mechanism and optical properties of the columns were also discussed. Optical absorption shows that In2O3 columns have a high band to band transition at ˜3.75 eV. The ultraviolet and green emissions were obtained from the In2O3 columnar arrays. The P-N junction was formed between In2O3 and P-type Si substrate. The GLAD synthesized In2O3 film exhibits low current conduction compared to In2O3 TF. However, the Si/GLAD-In2O3 detector shows ˜1.5 times enhanced photoresponsivity than that of Si/In2O3 TF.

Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions

PubMed Central

Chen, Jianzhong; Green, Kari B; Nichols, Kelly K

2015-01-01

A series of different types of wax esters (represented by RCOOR′) were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS3 (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2]+, [RCO]+ and [RCO – H2O]+ that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: 1) [RCOOH2]+ for saturated wax esters, 2) [RCOOH2]+, [RCO]+ and [RCO – H2O]+ for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and 3) [RCOOH2]+ and [RCO]+ for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R′]+ and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2]+ ions for all types of wax esters and [R′ – 2H]+ ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions. PMID:26178197

Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions.

PubMed

Chen, Jianzhong; Green, Kari B; Nichols, Kelly K

2015-08-01

A series of different types of wax esters (represented by RCOOR') were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS(3) (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2](+), [RCO](+) and [RCO-H2O](+) that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: (1) [RCOOH2](+) for saturated wax esters, (2) [RCOOH2](+), [RCO](+) and [RCO-H2O](+) for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and (3) [RCOOH2](+) and [RCO](+) for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R'](+) and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2](+) ions for all types of wax esters and [R'-2H](+) ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions.

Regulatory link between steryl ester formation and hydrolysis in the yeast Saccharomyces cerevisiae.

PubMed

Ploier, Birgit; Korber, Martina; Schmidt, Claudia; Koch, Barbara; Leitner, Erich; Daum, Günther

2015-07-01

Steryl esters and triacylglycerols are the major storage lipids of the yeast Saccharomyces cerevisiae. Steryl esters are formed in the endoplasmic reticulum by the two acyl-CoA:sterol acyltransferases Are1p and Are2p, whereas steryl ester hydrolysis is catalyzed by the three steryl ester hydrolases Yeh1p, Yeh2p and Tgl1p. To shed light on the regulatory link between steryl ester formation and hydrolysis in the maintenance of cellular sterol and free fatty acid levels we employed yeast mutants which lacked the enzymes catalyzing the degradation of steryl esters. These studies revealed feedback regulation of steryl ester formation by steryl ester hydrolysis although in a Δtgl1Δyeh1Δyeh2 triple mutant the gene expression levels of ARE1 and ARE2 as well as protein levels and stability of Are1p and Are2p were not altered. Nevertheless, the capacity of the triple mutant to synthesize steryl esters was significantly reduced as shown by in vitro and in vivo labeling of lipids with [(14)C]oleic acid and [(14)C]acetate. Enzymatic analysis revealed that inhibition of steryl ester formation occurred at the enzyme level. As the amounts and the formation of sterols and fatty acids were also decreased in the triple mutant we concluded that defects in steryl ester hydrolysis also caused feedback inhibition on the formation of sterols and fatty acids which serve as precursors for steryl ester formation. In summary, this study demonstrates a regulatory link within the steryl ester metabolic network which contributes to non-polar lipid homeostasis in yeast cells. Copyright © 2014 Elsevier B.V. All rights reserved.

21 CFR 172.854 - Polyglycerol esters of fatty acids.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyglycerol esters of fatty acids. 172.854 Section... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including the decaglycerol esters, may be safely used in food in...

Synthesis and low temperature characterization of iso-oleic ester derivatives

USDA-ARS?s Scientific Manuscript database

Three new iso-oleic ester derivatives (i.e., isopropyl esters (IOA-iPrE), n-butyl esters (IOA-n-BuE), and 2-ethylhexyl esters (IOA-2-EHE)) were synthesized from iso-oleic acid (IOA) using a standard esterification method. These esterified alcohols were chosen because of their bulky and branched-cha...

21 CFR 172.816 - Methyl glucoside-coconut oil ester.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Methyl glucoside-coconut oil ester. 172.816... § 172.816 Methyl glucoside-coconut oil ester. Methyl glucoside-coconut oil ester may be safely used in food in accordance with the following conditions: (a) It is the methyl glucoside-coconut oil ester...

Inter-observer variability between general pathologists and a specialist in breast pathology in the diagnosis of lobular neoplasia, columnar cell lesions, atypical ductal hyperplasia and ductal carcinoma in situ of the breast

PubMed Central

2014-01-01

Background This study aimed to assess inter-observer variability between the original diagnostic reports and later review by a specialist in breast pathology considering lobular neoplasias (LN), columnar cell lesions (CCL), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS) of the breast. Methods A retrospective, observational, cross-sectional study was conducted. A total of 610 breast specimens that had been formally sent for consultation and/or second opinions to the Breast Pathology Laboratory of Federal University of Minas Gerais were analysed between January 2005 and December 2010. The inter-observer variability between the original report and later review was compared regarding the diagnoses of LN, CCL, ADH, and DCIS. Statistical analyses were conducted using the Kappa index. Results Weak correlations were observed for the diagnoses of columnar cell change (CCC; Kappa = 0.38), columnar cell hyperplasia (CCH; Kappa = 0.32), while a moderate agreement (Kappa = 0.47) was observed for the diagnoses of flat epithelial atypia (FEA). Good agreement was observed in the diagnoses of atypical lobular hyperplasia (ALH; Kappa = 0.62) and lobular carcinoma in situ (LCIS; Kappa = 0.66). However, poor agreement was observed for the diagnoses of pleomorphic LCIS (Kappa = 0.22). Moderate agreement was observed for the diagnoses of ADH (Kappa = 0.44), low-grade DCIS (Kappa = 0.47), intermediate-grade DCIS (Kappa = 0.45), and DCIS with microinvasion (Kappa = 0.56). Good agreement was observed between the diagnoses of high-grade DCIS (Kappa = 0.68). Conclusions According to our data, the best diagnostic agreements were observed for high-grade DCIS, ALH, and LCIS. CCL without atypia and pleomorphic LCIS had the worst agreement indices. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1640072350119725. PMID:24948027

3D topology of orientation columns in visual cortex revealed by functional optical coherence tomography.

PubMed

Nakamichi, Yu; Kalatsky, Valery A; Watanabe, Hideyuki; Sato, Takayuki; Rajagopalan, Uma Maheswari; Tanifuji, Manabu

2018-04-01

Orientation tuning is a canonical neuronal response property of six-layer visual cortex that is encoded in pinwheel structures with center orientation singularities. Optical imaging of intrinsic signals enables us to map these surface two-dimensional (2D) structures, whereas lack of appropriate techniques has not allowed us to visualize depth structures of orientation coding. In the present study, we performed functional optical coherence tomography (fOCT), a technique capable of acquiring a 3D map of the intrinsic signals, to study the topology of orientation coding inside the cat visual cortex. With this technique, for the first time, we visualized columnar assemblies in orientation coding that had been predicted from electrophysiological recordings. In addition, we found that the columnar structures were largely distorted around pinwheel centers: center singularities were not rigid straight lines running perpendicularly to the cortical surface but formed twisted string-like structures inside the cortex that turned and extended horizontally through the cortex. Looping singularities were observed with their respective termini accessing the same cortical surface via clockwise and counterclockwise orientation pinwheels. These results suggest that a 3D topology of orientation coding cannot be fully anticipated from 2D surface measurements. Moreover, the findings demonstrate the utility of fOCT as an in vivo mesoscale imaging method for mapping functional response properties of cortex in the depth axis. NEW & NOTEWORTHY We used functional optical coherence tomography (fOCT) to visualize three-dimensional structure of the orientation columns with millimeter range and micrometer spatial resolution. We validated vertically elongated columnar structure in iso-orientation domains. The columnar structure was distorted around pinwheel centers. An orientation singularity formed a string with tortuous trajectories inside the cortex and connected clockwise and counterclockwise pinwheel centers in the surface orientation map. The results were confirmed by comparisons with conventional optical imaging and electrophysiological recordings.

Multilayered epithelium in a rat model and human Barrett's esophagus: Similar expression patterns of transcription factors and differentiation markers

PubMed Central

Chen, Xiaoxin; Qin, Rong; Liu, Ba; Ma, Yan; Su, Yinghao; Yang, Chung S; Glickman, Jonathan N; Odze, Robert D; Shaheen, Nicholas J

2008-01-01

Background In rats, esophagogastroduodenal anastomosis (EGDA) without concomitant chemical carcinogen treatment leads to gastroesophageal reflux disease, multilayered epithelium (MLE, a presumed precursor in intestinal metaplasia), columnar-lined esophagus, dysplasia, and esophageal adenocarcinoma. Previously we have shown that columnar-lined esophagus in EGDA rats resembled human Barrett's esophagus (BE) in its morphology, mucin features and expression of differentiation markers (Lab. Invest. 2004;84:753–765). The purpose of this study was to compare the phenotype of rat MLE with human MLE, in order to gain insight into the nature of MLE and its potential role in the development of BE. Methods Serial sectioning was performed on tissue samples from 32 EGDA rats and 13 patients with established BE. Tissue sections were immunohistochemically stained for a variety of transcription factors and differentiation markers of esophageal squamous epithelium and intestinal columnar epithelium. Results We detected MLE in 56.3% (18/32) of EGDA rats, and in all human samples. As expected, both rat and human squamous epithelium, but not intestinal metaplasia, expressed squamous transcription factors and differentiation markers (p63, Sox2, CK14 and CK4) in all cases. Both rat and human intestinal metaplasia, but not squamous epithelium, expressed intestinal transcription factors and differentiation markers (Cdx2, GATA4, HNF1α, villin and Muc2) in all cases. Rat MLE shared expression patterns of Sox2, CK4, Cdx2, GATA4, villin and Muc2 with human MLE. However, p63 and CK14 were expressed in a higher proportion of rat MLE compared to humans. Conclusion These data indicate that rat MLE shares similar properties to human MLE in its expression pattern of these markers, not withstanding small differences, and support the concept that MLE may be a transitional stage in the metaplastic conversion of squamous to columnar epithelium in BE. PMID:18190713

Multilayered epithelium in a rat model and human Barrett's esophagus: similar expression patterns of transcription factors and differentiation markers.

PubMed

Chen, Xiaoxin; Qin, Rong; Liu, Ba; Ma, Yan; Su, Yinghao; Yang, Chung S; Glickman, Jonathan N; Odze, Robert D; Shaheen, Nicholas J

2008-01-11

In rats, esophagogastroduodenal anastomosis (EGDA) without concomitant chemical carcinogen treatment leads to gastroesophageal reflux disease, multilayered epithelium (MLE, a presumed precursor in intestinal metaplasia), columnar-lined esophagus, dysplasia, and esophageal adenocarcinoma. Previously we have shown that columnar-lined esophagus in EGDA rats resembled human Barrett's esophagus (BE) in its morphology, mucin features and expression of differentiation markers (Lab. Invest. 2004;84:753-765). The purpose of this study was to compare the phenotype of rat MLE with human MLE, in order to gain insight into the nature of MLE and its potential role in the development of BE. Serial sectioning was performed on tissue samples from 32 EGDA rats and 13 patients with established BE. Tissue sections were immunohistochemically stained for a variety of transcription factors and differentiation markers of esophageal squamous epithelium and intestinal columnar epithelium. We detected MLE in 56.3% (18/32) of EGDA rats, and in all human samples. As expected, both rat and human squamous epithelium, but not intestinal metaplasia, expressed squamous transcription factors and differentiation markers (p63, Sox2, CK14 and CK4) in all cases. Both rat and human intestinal metaplasia, but not squamous epithelium, expressed intestinal transcription factors and differentiation markers (Cdx2, GATA4, HNF1alpha, villin and Muc2) in all cases. Rat MLE shared expression patterns of Sox2, CK4, Cdx2, GATA4, villin and Muc2 with human MLE. However, p63 and CK14 were expressed in a higher proportion of rat MLE compared to humans. These data indicate that rat MLE shares similar properties to human MLE in its expression pattern of these markers, not withstanding small differences, and support the concept that MLE may be a transitional stage in the metaplastic conversion of squamous to columnar epithelium in BE.

Columnar characteristics of aerosols by spectroradiometer measurements in the maritime area of the Cadiz Gulf (Spain)

NASA Astrophysics Data System (ADS)

Vergaz, Ricardo; Cachorro, Victoria E.; de Frutos, Ángel M.; Vilaplana, José M.; de La Morena, Benito A.

2005-11-01

Atmospheric aerosol characteristics represented by the spectral aerosol optical depth AOD) and the Ångström turbidity parameter were determined in the coastal area of the Gulf of Cádiz, (southwest of Spain). The columnar aerosol properties presented here correspond to the 1996-1999 period, and were obtained by solar direct irradiance measurements carried out by a Licor1800 spectroradiometer. The performance of this type of medium-spectral resolution radiometric system is analysed over the measured period. The detailed spectral information of these irradiance measurements enabled the use of selected non-absorption gases spectral windows to determine the columnar spectral AOD that was modelled by Ångström formula to obtain the coefficient. Temporal evolutions of instantaneous values together with a general statistical analysis represented by seasonal values, frequency distributions and some representative correlations for the AOD and the derived Ångström coefficient gave us the first insight of aerosol characteristics in this coastal area. Special attention was paid to the analysis of these aerosol properties at the nominal wavelengths of 440 nm, 670 nm, 870 nm and 1020 nm for the near-future comparisons with the Cimel sun-photometer data. However, taking the most representative aerosol wavelength of 500 nm, the variability of the AOD ranges from 0.005 to 0.53, with a mean of 0.12 (s.d = 0.07) and that of the parameter is given by a mean value of 0.93 (s.d. = 0.58) falling inside the range of marine aerosols. A quantitative discrimination of aerosol types was conducted on the basis of the spectral aerosol properties and air mass back trajectory analysis, which resulted in a mixed type because of the specificity of this area, given by very frequent desert dust episodes, continental and polluted local influences. This study represents the first extended data characterization about columnar properties of aerosols in Spain which has been continued by Cimel-AERONET data. Copyright

Involvement of two glycoside hydrolase family 19 members in colony morphotype and virulence in Flavobacterium columnare

NASA Astrophysics Data System (ADS)

Zhang, Xiaolin; Li, Nan; Qin, Ting; Huang, Bei; Nie, Pin

2017-11-01

Flavobacterium columnare is the pathogenic agent of columnaris disease in aquaculture. Using a recently developed gene deletion strategy, two genes that encode the Glyco_hydro_19 domain (GH19 domain) containing proteins, ghd-1 and ghd-2, were deleted separately and together from the F. columnare G4 wild type strain. Surprisingly, the single-, Δ ghd-1 and Δ ghd-2, and double-gene mutants, Δ ghd-1 Δghd -2, all had rhizoid and non-rhizoid colony morphotypes, which we named Δ ghd-1, Δ ghd-2, Δ ghd-1 Δ ghd-2, and NΔ ghd-1, NΔ ghd-2, and NΔ ghd-1 Δ ghd-2. However, chitin utilization was not detected in either these mutants or in the wild type. Instead, skimmed milk degradation was observed for the mutants and the wild type; the non-rhizoid strain NΔ ghd-2 exhibited higher degradation activity as revealed by the larger transparent circle on the skimmed milk plate. Using zebrafish as the model organism, we found that non-rhizoid mutants had higher LD50 values and were less virulent because zebrafish infected with these survived longer. Transcriptome analysis between the non-rhizoid and rhizoid colony morphotypes of each mutant, i.e., NΔ ghd -1 versus (vs) Δ ghd-1, NΔ ghd-2 vs Δ ghd-2, and NΔ ghd-1 Δ ghd-2 vs Δ ghd-1 Δ ghd-2, revealed a large number of differentially expressed genes, among which 39 genes were common in three of the pairs compared. Although most of these genes encode hypothetical proteins, a few molecules such as phage tail protein, rhs element Vgr protein, thiol-activated cytolysin, and TonB-dependent outer membrane receptor precursor, expression of which was down-regulated in non-rhizoid mutants but up-regulated in rhizoid mutants, may play a role F. columnare virulence.

Impact of oral and waterborne administration of rhamnolipids on the susceptibility of channel catfish (Ictalurus punctatus) to Flavobacterium columnare infection.

PubMed

Zhang, Dongdong; Beck, Benjamin H; Lange, Miles; Zhao, Honggang; Thongda, Wilawan; Ye, Zhi; Li, Chao; Peatman, Eric

2017-01-01

Flavobacterium columnare is the causative agent of columnaris disease and causes tremendous morbidity and mortality of farmed fish globally. Previously, we identified a potential lectin-mediator (a rhamnose-binding lectin; RBL1a) of F. columnare adhesion and showed higher RBL1a expression in susceptible channel catfish under basal conditions and following infection. Exposure of challenged fish to the carbohydrate ligand l-rhamnose just prior to a challenge substantially decreased columnaris mortality and pathogen adherence via the down-regulation of RBL1a. While highly effective in protecting fish from columnaris, l-rhamnose is prohibitively expensive, underscoring the need for alternative cost-effective sources of rhamnose for disease control. One such alternative may be microbially produced glycolipid compounds termed rhamnolipids (RLs), which feature abundant l-rhamnose moieties and are readily available from commercial sources. In the present study, we examined whether commercially available RLs (administered either by immersion or via feed) would function similarly to l-rhamnose in affording host protection against F. columnare. A four-week feeding trial with basal and RL top-coated diets (basal diet + RLs) was conducted in channel catfish fingerlings. Surprisingly, columnaris challenges revealed significantly lower survival following the 10 d challenge period in RL diet fed fish when compared with the basal treatment group (p < 0.001). In fish fed RLs, we observed a rapid and large-scale upregulation of RBL1a immediately after challenge combined with a suppression of mucin and lysozyme transcripts. Similarly, fish that were briefly pre-exposed to RLs by immersion and then challenged exhibited lower survival as compared to unexposed fish during a 4 d trial. In conclusion, RLs do not represent an alternative to rhamnose as an experimental treatment for protecting catfish from columnaris mortality. Further research is needed to find other affordable and efficacious alternative sources of l-rhamnose. Copyright © 2016 Elsevier Ltd. All rights reserved.

Immunogenicity and protective role of antigenic regions from five outer membrane proteins of Flavobacterium columnare in grass carp Ctenopharyngodon idella

NASA Astrophysics Data System (ADS)

Luo, Zhang; Liu, Zhixin; Fu, Jianping; Zhang, Qiusheng; Huang, Bei; Nie, Pin

2016-11-01

Flavobacterium columnare causes columnaris disease in freshwater fish. In the present study, the antigenic regions of five outer membrane proteins (OMPs), including zinc metalloprotease, prolyl oligopeptidase, thermolysin, collagenase and chondroitin AC lyase, were bioinformatically analyzed, fused together, and then expressed as a recombinant fusion protein in Escherichia coli. The expressed protein of 95.6 kDa, as estimated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was consistent with the molecular weight deduced from the amino acid sequence. The purified recombinant protein was used to vaccinate the grass carp, Ctenopharyngodon idella. Following vaccination of the fish their IgM antibody levels were examined, as was the expression of IgM, IgD and IgZ immunoglobulin genes and other genes such as MHC Iα and MHC IIβ, which are also involved in adaptive immunity. Interleukin genes ( IL), including IL-1β, IL-8 and IL-10, and type I and type II interferon ( IFN) genes were also examined. At 3 and 4 weeks post-vaccination (wpv), significant increases in IgM antibody levels were observed in the fish vaccinated with the recombinant fusion protein, and an increase in the expression levels of IgM, IgD and IgZ genes was also detected following the vaccinations, thus indicating that an adaptive immune response was induced by the vaccinations. Early increases in the expression levels of IL and IFN genes were also observed in the vaccinated fish. At four wpv, the fish were challenged with F. columnare, and the vaccinated fish showed a good level of protection against this pathogen, with 39% relative percent survival (RPS) compared with the control group. It can be concluded, therefore, that the five OMPs, in the form of a recombinant fusion protein vaccine, induced an immune response in fish and protection against F. columnare.

Inter-observer variability between general pathologists and a specialist in breast pathology in the diagnosis of lobular neoplasia, columnar cell lesions, atypical ductal hyperplasia and ductal carcinoma in situ of the breast.

PubMed

Gomes, Douglas S; Porto, Simone S; Balabram, Débora; Gobbi, Helenice

2014-06-19

This study aimed to assess inter-observer variability between the original diagnostic reports and later review by a specialist in breast pathology considering lobular neoplasias (LN), columnar cell lesions (CCL), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS) of the breast. A retrospective, observational, cross-sectional study was conducted. A total of 610 breast specimens that had been formally sent for consultation and/or second opinions to the Breast Pathology Laboratory of Federal University of Minas Gerais were analysed between January 2005 and December 2010. The inter-observer variability between the original report and later review was compared regarding the diagnoses of LN, CCL, ADH, and DCIS. Statistical analyses were conducted using the Kappa index. Weak correlations were observed for the diagnoses of columnar cell change (CCC; Kappa=0.38), columnar cell hyperplasia (CCH; Kappa=0.32), while a moderate agreement (Kappa=0.47) was observed for the diagnoses of flat epithelial atypia (FEA). Good agreement was observed in the diagnoses of atypical lobular hyperplasia (ALH; Kappa=0.62) and lobular carcinoma in situ (LCIS; Kappa=0.66). However, poor agreement was observed for the diagnoses of pleomorphic LCIS (Kappa=0.22). Moderate agreement was observed for the diagnoses of ADH (Kappa=0.44), low-grade DCIS (Kappa=0.47), intermediate-grade DCIS (Kappa=0.45), and DCIS with microinvasion (Kappa=0.56). Good agreement was observed between the diagnoses of high-grade DCIS (Kappa=0.68). According to our data, the best diagnostic agreements were observed for high-grade DCIS, ALH, and LCIS. CCL without atypia and pleomorphic LCIS had the worst agreement indices. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1640072350119725.

High-Speed Photorefractive Response Capability in Triphenylamine Polymer-Based Composites

NASA Astrophysics Data System (ADS)

Tsujimura, Sho; Kinashi, Kenji; Sakai, Wataru; Tsutsumi, Naoto

2012-06-01

We present here the poly(4-diphenylamino)styrene (PDAS)-based photorefractive composites with a high-speed response time. PDAS was synthesized as a photoconductive polymer and photorefractive polymeric composite (PPC) films by using triphenylamine (TPA) (or ethylcarbazole, ECZ), 4-homopiperidino-2-fluorobenzylidene malononitrile (FDCST), and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were investigated. The photorefractive quantities of the PDAS-based PPCs were determined by a degenerate four-wave mixing (DFWM) technique. Additionally, the holographic images were recorded through an appropriate PDAS-based PPC. Those holographic images clearly reconstruct the original motion with high-speed quality. The present approach provides a promising candidate for the future application of dynamic holographic displays.

Secondary metabolites from Penicillium pinophilum SD-272, a marine sediment-derived fungus.

PubMed

Wang, Ming-Hui; Li, Xiao-Ming; Li, Chun-Shun; Ji, Nai-Yun; Wang, Bin-Gui

2013-06-21

Two new secondary metabolites, namely, pinodiketopiperazine A (1) and 6,7-dihydroxy-3-methoxy-3-methylphthalide (2), along with alternariol 2,4-dimethyl ether (3) and L-5-oxoproline methyl ester (4), which were isolated from a natural source for the first time but have been previously synthesized, were characterized from the marine sediment-derived fungus Penicillium pinophilum SD-272. In addition, six known metabolites (5-10) were also identified. Their structures were elucidated by analysis of the NMR and mass spectroscopic data. The absolute configuration of compound 1 was determined by experimental and calculated ECD spectra. Compound 2 displayed potent brine shrimp (Artemia salina) lethality with LD₅₀ 11.2 μM.

A new phenolic compound with antioxidant activity from the branches and leaves of Pyrus pashia.

PubMed

Li, Zhen-Jie; Zheng, Xi; Wan, Chun-Ping; Cai, Le; Li, Ying; Huang, Lin; Ding, Zhong-Tao

2016-01-01

The branches and leaves of Pyrus pashia are used to cure abdominal pain and diarrhoea in Chinese folk medicine. A new phenilic compound, 4-O-β-d-glucopyranosylbenzyl-benzoate ester (1), along with 21 known ones (2-22) were isolated from the branches and leaves of this plant. Compounds 2 and 3 displayed remarkable antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl radical (IC50 = 13.26 ± 0.04 μM, 13.28 ± 0.11 μM, respectively), which were at the same grade as positive control rutin. The caffeoyl group in compounds 2 and 3 was supposed to play an important role in the antioxidant activities.

Fully convergent chemical synthesis of ester insulin: determination of the high resolution X-ray structure by racemic protein crystallography.

PubMed

Avital-Shmilovici, Michal; Mandal, Kalyaneswar; Gates, Zachary P; Phillips, Nelson B; Weiss, Michael A; Kent, Stephen B H

2013-02-27

Efficient total synthesis of insulin is important to enable the application of medicinal chemistry to the optimization of the properties of this important protein molecule. Recently we described "ester insulin"--a novel form of insulin in which the function of the 35 residue C-peptide of proinsulin is replaced by a single covalent bond--as a key intermediate for the efficient total synthesis of insulin. Here we describe a fully convergent synthetic route to the ester insulin molecule from three unprotected peptide segments of approximately equal size. The synthetic ester insulin polypeptide chain folded much more rapidly than proinsulin, and at physiological pH. Both the D-protein and L-protein enantiomers of monomeric DKP ester insulin (i.e., [Asp(B10), Lys(B28), Pro(B29)]ester insulin) were prepared by total chemical synthesis. The atomic structure of the synthetic ester insulin molecule was determined by racemic protein X-ray crystallography to a resolution of 1.6 Å. Diffraction quality crystals were readily obtained from the racemic mixture of {D-DKP ester insulin + L-DKP ester insulin}, whereas crystals were not obtained from the L-ester insulin alone even after extensive trials. Both the D-protein and L-protein enantiomers of monomeric DKP ester insulin were assayed for receptor binding and in diabetic rats, before and after conversion by saponification to the corresponding DKP insulin enantiomers. L-DKP ester insulin bound weakly to the insulin receptor, while synthetic L-DKP insulin derived from the L-DKP ester insulin intermediate was fully active in binding to the insulin receptor. The D- and L-DKP ester insulins and D-DKP insulin were inactive in lowering blood glucose in diabetic rats, while synthetic L-DKP insulin was fully active in this biological assay. The structural basis of the lack of biological activity of ester insulin is discussed.

Fully Convergent Chemical Synthesis of Ester Insulin: Determination of the High Resolution X-ray Structure by Racemic Protein Crystallography

PubMed Central

Avital-Shmilovici, Michal; Mandal, Kalyaneswar; Gates, Zachary P.; Phillips, Nelson B.; Weiss, Michael A.; Kent, Stephen B.H.

2013-01-01

Efficient total synthesis of insulin is important to enable the application of medicinal chemistry to the optimization of the properties of this important protein molecule. Recently we described ‘ester insulin’ – a novel form of insulin in which the function of the 35 residue C-peptide of proinsulin is replaced by a single covalent bond – as a key intermediate for the efficient total synthesis of insulin. Here we describe a fully convergent synthetic route to the ester insulin molecule from three unprotected peptide segments of approximately equal size. The synthetic ester insulin polypeptide chain folded much more rapidly than proinsulin, and at physiological pH. Both the D-protein and L-protein enantiomers of monomeric DKP ester insulin (i.e. [AspB10, LysB28, ProB29]ester insulin) were prepared by total chemical synthesis. The atomic structure of the synthetic ester insulin molecule was determined by racemic protein X-ray crystallography to a resolution of 1.6 Å. Diffraction quality crystals were readily obtained from the racemic mixture of {D-DKP ester insulin + L-DKP ester insulin}, whereas crystals were not obtained from the L-ester insulin alone even after extensive trials. Both the D-protein and L-protein enantiomers of monomeric DKP ester insulin were assayed for receptor binding and in diabetic rats, before and after conversion by saponification to the corresponding DKP insulin enantiomers. L-DKP ester insulin bound weakly to the insulin receptor, while synthetic L-DKP insulin derived from the L-DKP ester insulin intermediate was fully active in binding to the insulin receptor. The D- and L-DKP ester insulins and D-DKP insulin were inactive in lowering blood glucose in diabetic rats, while synthetic L-DKP insulin was fully active in this biological assay. The structural basis of the lack of biological activity of ester insulin is discussed. PMID:23343390

Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 1: Condensation of phthalic anhydride with acetoacetic and malonic ester

NASA Technical Reports Server (NTRS)

Oshkaya, V. P.; Vanag, G. Y.

1985-01-01

Phthalic anhydride was condensed with acetoacetic ester in acetic anhydride and triethylamine solution, and when phthalyl chloride was reacted with sodium acetoacetic ester compounds were formed of the phthalide and indandione series: phthalylacetoacetic ester and a derivative of indan-1,3-dione which after boiling with hydrochloric acid yielded indan-1,3-dione. Phthalylmalonic ester was obtained from phthalic anhydride and malonic ester in the presence of triethylamine.

Evaluation of Barrett esophagus by multiphoton microscopy.

PubMed

Chen, Jianxin; Wong, Serena; Nathanson, Michael H; Jain, Dhanpat

2014-02-01

Multiphoton microscopy (MPM) based on 2-photon excitation fluorescence and second-harmonic generation allows simultaneous visualization of cellular details and extracellular matrix components of fresh, unfixed, and unstained tissue. Portable multiphoton microscopes, which could be placed in endoscopy suites, and multiphoton endomicroscopes are in development, but their clinical utility is unknown. To examine fresh, unfixed endoscopic biopsies obtained from the distal esophagus and gastroesophageal junction to (1) define the MPM characteristics of normal esophageal squamous mucosa and gastric columnar mucosa, and (2) evaluate whether diagnosis of intestinal metaplasia/Barrett esophagus (BE) could be made reliably with MPM. The study examined 35 untreated, fresh biopsy specimens from 25 patients who underwent routine upper endoscopy. A Zeiss LSM 710 Duo microscope (Carl Zeiss, Thornwood, New York) coupled to a Spectra-Physics (Mountain View, California) Tsunami Ti:sapphire laser was used to obtain a MPM image within 4 hours of fresh specimen collection. After obtaining MPM images, the biopsy specimens were placed in 10% buffered formalin and submitted for routine histopathologic examination. Then, the MPM images were compared with the findings in the hematoxylin-eosin-stained, formalin-fixed, paraffin-embedded sections. The MPM characteristics of the squamous, gastric-type columnar and intestinal-type columnar epithelium were analyzed. In biopsies with discrepancy between MPM imaging and hematoxylin-eosin-stained sections, the entire tissue block was serially sectioned and reevaluated. A diagnosis of BE was made when endoscopic and histologic criteria were satisfied. Based on effective 2-photon excitation fluorescence of cellular reduced pyridine nucleotides and flavin adenine dinucleotide and lack of 2-photon excitation fluorescence of mucin and cellular nuclei, MPM could readily identify and distinguish among squamous epithelial cells, goblet cells, gastric foveolar-type mucous cells, and parietal cells in the area of gastroesophageal junction. Based on the cell types identified, the mucosa was defined as squamous, columnar gastric type (cardia/fundic-type), and metaplastic columnar intestinal-type/BE. Various types of mucosa seen in the study of 35 biopsies included normal squamous mucosa only (n = 14; 40%), gastric cardia-type mucosa only (n = 2; 6%), gastric fundic mucosa (n = 6; 17%), and both squamous and gastric mucosa (n = 13; 37%). Intestinal metaplasia was identified by the presence of goblet cells in 10 of 25 cases (40%) leading to a diagnosis of BE on MPM imaging and only in 7 cases (28%) by histopathology. In 3 of 35 biopsies (9%), clear-cut goblet cells were seen by MPM imaging but not by histopathology, even after the entire tissue block was sectioned. Based on effective 2-photon excitation fluorescence of elastin and second-harmonic generation of collagen, connective tissue in the lamina propria and the basement membrane was also visualized with MPM. Multiphoton microscopy has the ability to accurately distinguish squamous epithelium and different cellular elements of the columnar mucosa obtained from biopsies around the gastroesophageal junction, including goblet cells that are important for the diagnosis of BE. Thus, use of MPM in the endoscopy suite might provide immediate microscopic images during endoscopy, improving screening and surveillance of patients with BE.

21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glyceryl-lacto esters of fatty acids. 172.852... HUMAN CONSUMPTION Multipurpose Additives § 172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely used in food in...

Fatigue properties for the fracture strength of columnar accessory minerals embedded within metamorphic tectonites: implications for stress magnitude in continental crust at the depth of the brittle-plastic transition zone

NASA Astrophysics Data System (ADS)

Kimura, N.; Iwashita, N.; Masuda, T.

2009-04-01

1. Introduction Previous studies have compiled yield-strength profiles of continental lithosphere based on the results of laboratory measurements and numerical calculations; however, yield-strength values remain poorly constrained, especially at depths below the brittle-plastic transition zone. Recent studies by the authors have refined the microboudin technique for estimating palaeostress magnitude in the deep crust (> 10 km depth). This technique has the potential to provide important information on stress levels in the deep continental crust, an environment to which available in situ stress measurements and palaeopiezometric methods cannot be applied. In applying the microboudinage technique, obtaining an estimate of the palaeostress magnitude requires knowledge of the fracture strength of columnar accessory minerals (e.g., tourmaline, amphibole, and epidote) that are subjected to brittle fracturing during plastic deformation of the surrounding matrix minerals. The absolute magnitude of fracture strength is known to show a marked reduction in the case of fatigue fracture. Fatigue fracture falls into two categories: static fatigue and cyclic fatigue. In the field of experimental rock deformation, stress corrosion by water molecules (static fatigue) is commonly invoked as the mechanism of fatigue fracture; however, evidence of both static and cyclic fatigue has been reported from studies of natural geological samples. The present study focused on the fatigue properties of columnar accessory minerals at high temperatures, with the aim of improving the accuracy of estimates of natural palaeostress magnitude at depth in the crust. 2. Constant stress-rate test A constant stress-rate test was performed to determine the influence of static fatigue on the strength of columnar accessory minerals. The test was conducted under three-point bending with a span distance of 10 mm. Temperature conditions and the crosshead speed were set in the ranges of ambient to 600°C, and 0.0005 to 0.2 mm/min, respectively. Pressure and relative humidity were set to room conditions. Tourmaline was chosen for testing (as representative of columnar accessory minerals embedded within metamorphic tectonites) because this is the only mineral for which crystals are available of sufficient size and quality. A total of 120 prism-shaped tourmaline test pieces (dimensions, 2×2×12 mm) were prepared from a single tourmaline block collected from Minas Gerais, Brazil. The flexural strength of tourmaline shows a clear decrease with decreasing crosshead speed at ambient temperature (with n ≈ 15 as the static fatigue parameter); however, this trend weakens with increasing temperature (n > 50); that is, the influence of static fatigue on the strength of tourmaline decreases with increasing temperature. A comparable result has been reported for glass materials because of difficulties in the absorption of moisture on sample surfaces under high-temperature conditions. The fabric pattern of fracture planes developed in tourmaline specimens in the present study, which show rectilinear scratches, arrests, or Wallner lines on smooth surfaces, is similar to that observed for glass materials. 3. Fractography of naturally deformed minerals A ‘striation-like' pattern resulting from cyclic fatigue fracture was observed by scanning electron microscope (SEM) analysis of a natural fracture plane developed within marble-hosted amphibole. The sample was collected from the eastern flank of the Red River shear zone (Luc Yen district), northern Vietnam. The brittle fracturing of amphibole (open fractures were filled by calcite, which deforms plastically) is considered to have occurred at 6 km depth at 25 Ma, based on geological criteria. 4. Order of stress magnitude in continental crust at the depth of the brittle-plastic transition zone Assuming that the fracture behaviour of columnar accessory minerals during the development of microboudinage is independent of the mineral species, the above results raise the possibility that the fracturing of columnar accessory minerals at deep crustal levels is governed by cyclic fatigue, possibly attributed to mechanical degradation rather than stress corrosion associated with water molecules, and that the fracture behaviour of columnar accessory minerals is similar to that of glass materials. Thus, cyclic fatigue studies of glass materials are expected to provide a good reference for approximate estimates of the fatigue limit of columnar accessory minerals. According to the literature, the fatigue limit for many glass materials is approximately 10% of the ultimate tensile strength. Taking into account the influence of fatigue fracture, the obtained magnitudes of palaeodifferential stress at crustal depths of 10-20 km, as estimated using the microboudinage technique, are in the low tens of megapascals (e.g., 10 MPa at 9 km depth, as obtained from metacherts within high-pressure rocks in Japan; 25 MPa at 12 km depth, as obtained from metachert within a metamorphic sole in the UAE; 9 MPa at 18 km depth, as obtained from metachert within high-pressure rocks in China; and 14 MPa at 18 km depth, as obtained from metachert within high-pressure rocks in Turkey). These values are much lower than those obtained from laboratory measurements.

Myo-inositol esters of indole-3-acetic acid are endogenous components of Zea mays L. shoot tissue

NASA Technical Reports Server (NTRS)

Chisnell, J. R.

1984-01-01

Indole-3-acetyl-myo-inositol esters have been demonstrated to be endogenous components of etiolated Zea mays shoots tissue. This was accomplished by comparison of the putative compounds with authentic, synthetic esters. The properties compared were liquid and gas-liquid chromatographic retention times and the 70-ev mass spectral fragmentation pattern of the pentaacetyl derivative. The amount of indole-3-acetyl-myo-inositol esters in the shoots was determined to be 74 nanomoles per kilogram fresh weight as measured by isotope dilution, accounting for 19% of the ester indole-3-acetic acid of the shoot. This work is the first characterization of an ester conjugate of indole-3-acetate acid from vegetative shoot tissue using multiple chromatographic properties and mass spectral identification. The kernel and the seedling shoot both contain indole-3-acetyl-myo-inositol esters, and these esters comprise approximately the same percentage of the total ester content of the kernel and of the shoot.

Production of wax esters via microbial oil synthesis from food industry waste and by-product streams.

PubMed

Papadaki, Aikaterini; Mallouchos, Athanasios; Efthymiou, Maria-Nefeli; Gardeli, Chryssavgi; Kopsahelis, Nikolaos; Aguieiras, Erika C G; Freire, Denise M G; Papanikolaou, Seraphim; Koutinas, Apostolis A

2017-12-01

The production of wax esters using microbial oils was demonstrated in this study. Microbial oils produced from food waste and by-product streams by three oleaginous yeasts were converted into wax esters via enzymatic catalysis. Palm oil was initially used to evaluate the influence of temperature and enzyme activity on wax ester synthesis catalysed by Novozyme 435 and Lipozyme lipases using cetyl, oleyl and behenyl alcohols. The highest conversion yields (up to 79.6%) were achieved using 4U/g of Novozyme 435 at 70°C. Transesterification of microbial oils to behenyl and cetyl esters was achieved at conversion yields up to 87.3% and 69.1%, respectively. Novozyme 435 was efficiently reused for six and three cycles during palm esters and microbial esters synthesis, respectively. The physicochemical properties of microbial oil derived behenyl esters were comparable to natural waxes. Wax esters from microbial oils have potential applications in cosmetics, chemical and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta

NASA Astrophysics Data System (ADS)

Yang, Zhihui; Zhang, Xiangjing; Cai, Zhonghua

2009-05-01

As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP, DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.

Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity

PubMed Central

Régnier, Philippe; Bastias, Jorge; Rodriguez-Ruiz, Violeta; Caballero-Casero, Noelia; Caballo, Carmen; Sicilia, Dolores; Fuentes, Axelle; Maire, Murielle; Crepin, Michel; Letourneur, Didier; Gueguen, Virginie; Rubio, Soledad; Pavon-Djavid, Graciela

2015-01-01

Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases. PMID:25962124

Down-modulation of receptors for phorbol ester tumor promoter in primary epidermal cells

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

Solanki, V.; Slaga, T.J.

1982-01-01

The specific (20-/sup 3/H)phorbol 12,13-dibutyrate ((/sup 3/H)PDBu) binding to intact epidermal cells displayed the phenomenon of down-modulation, i.e., the specific binding of (/sup 3/H)PDBu to its receptors on primary epidermal cells reached a maximum within 1 h and steadily declined thereafter. The apparent down-modulation of radiolabel resulted from a partial loss in the total number of receptors; the affinity of receptors for the ligand was essentially unchanged. A number of agents such as chloroquine, methylamine, or arginine which are known to prevent clustering, down-modulation, and/or internalization of several hormone receptors did not affect the down-modulation of phorbol ester receptors. Furthermore,more » cycloheximide had no effect either on down-modulation or on the binding capacity of cells. The surface binding capacity of down-modulated cells following a 90-min incubation with unlabeled ligand was almost returned to normal within 1 h. The effect of the antidepressant drug chlorpromazine, which is known to interact with calmodulin, on (/sup 3/H)PDBu binding was also investigated. Our data indicate that the effect of chlorpromazine on (/sup 3/H)PDBu binding is probably unrelated to its calmodulin-binding activity.« less

Phytotoxic Metabolites Produced by Diaporthella cryptica, the Causal Agent of Hazelnut Branch Canker.

PubMed

Cimmino, Alessio; Nocera, Paola; Linaldeddu, Benedetto Teodoro; Masi, Marco; Gorecki, Marcin; Pescitelli, Gennaro; Montecchio, Lucio; Maddau, Lucia; Evidente, Antonio

2018-04-04

From the culture filtrates of Diaporthella cryptica, an emerging hazelnut pathogen, 2-hydroxy-3-phenylpropanoate methyl ester and its 3-(4-hydroxyphenyl) and 3-(1 H-indol-3-yl) analogues, named crypticins A-C, were isolated together with the well-known tyrosol. Crypticins A-C were identified by spectroscopic (essentially nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry) methods. The R absolute configuration (AC) of crypticin A was determined by comparing its optical rotation and electronic circular dichroism (ECD) spectrum with those of papuline, the methyl ester of (-)( S)-phenyllactic acid isolated as the main phytotoxin of Pseudomonas syringae pv.  papulans, responsible for apple blister spot. The ACs of crypticins B and C were determined by time-dependent density functional theory calculations of their ECD spectra. Papuline and the new metabolites herein isolated, except tyrosol, were tested at 1 mg/mL on cork oak, grapevine, hazelnut, and holm oak leaves using the leaf puncture assay. They were also tested on tomato cuttings at 0.5 and 0.05 mg/mL. In the leaf puncture assay, none of the compounds was found to be active. Crypticin C and papuline were active in the tomato cutting assay. Additionally, crypticin C displayed moderate inhibitory effect against Phytophthora cambivora.

[Development of the determination methods of fatty acid esters of chloropropanediols in fat-rich foods].

PubMed

Yan, Xiaobo; Wu, Shaoming; Li, Nan; Lü, Huadong; Fu, Wusheng

2013-02-01

Fatty acid esters of chloropropanediols are a kinds of newly emerged food contaminants, especially 3-monochloropropane-1,2-diol (3-MCPD) esters that have been detected in many foodstuffs such as infant formula and edible oils at relatively high levels. Based on the Tolerable Dose Intake (TDI) of 3-MCPD, the intake of 3-MCPD from 3-MCPD esters may cause the health risk to human beings. The researches for the analysis of 3-MCPD esters have been carried out in some institutes abroad, but there were only a few in China. This paper reviews the methods for the determination of 3-MCPD esters in fat-rich foods, including the extraction, hydrolysis, the derivatization of 3-MCPD esters, the total amount of 3-MCPD esters and the amounts of monoesters and diesters of 3-MCPD.

Plant Natural compounds with antibacterial activity towards common pathogens of pond-cultured channel catfish (Ictalurus punctatus).

PubMed

Schrader, Kevin K

2010-07-01

The bacteria Edwardsiella ictaluri and Flavobacterium columnare cause enteric septicemia and columnaris disease, respectively, in channel catfish (Ictalurus punctatus). Natural therapeutants may provide an alternative to current management approaches used by producers. In this study, a rapid bioassay identified plant compounds as potential therapeutants. Chelerythrine chloride and ellagic acid were the most toxic toward E. ictaluri, with 24-h IC50 of 7.3 mg/L and 15.1 mg/L, respectively, and MIC of 2.1 mg/L and 6.5 mg/L, respectively. Chelerythrine chloride, ellagic acid, β-glycyrrhetinic acid, sorgoleone, and wogonin were the most toxic towards two genomovars of F. columnare, and wogonin had the strongest antibacterial activity (MIC = 0.3 mg/L).

Optimization of esterification of oleic acid and trimethylolpropane (TMP) and pentaerythritol (PE)

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

Mahmud, Hamizah Ammarah; Salimon, Jumat

Vegetable oil (VO) is the most potential alternative to replace mineral oil for lubricant due to better lubricating properties and great physicochemical properties. Chemical modification has to be done to overcome low temperature performance and low oxidation instability due to the presence of β-hydrogen atoms of glycerol molecule. The optimization of esterification of oleic acid and polyhydric alcohol with sulfuric acid catalyst was carried out to find the optimum conditions with the highest yield. Reeaction variables such as; molar ratio, temperature, duration and catalyst concentration. Two types of polyhydric alcohol have been used; TMP and PE. The optimum results showedmore » oleic acid successfully converted 91.2% ester TMP and 92.7% ester PE at duration: 5 hours (Ester TMP), 6 hours (Ester PE); temperature: 150°C (ester TMP), 180°C (Ester PE); catalyst concentration: 1.5% (w/w); and mol ratio: 3.9:1 (ester TMP), 4.9:1 (ester PE). From the data obtained, mole ratio showed most influenced factors to the increasing yields of ester conversions.. The TMP/PE ester was confirmed using gas chromatography (GC-FID), Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR)« less

Metabolic engineering of Saccharomyces cerevisiae for production of fatty acid short- and branched-chain alkyl esters biodiesel.

PubMed

Teo, Wei Suong; Ling, Hua; Yu, Ai-Qun; Chang, Matthew Wook

2015-01-01

Biodiesel is a mixture of fatty acid short-chain alkyl esters of different fatty acid carbon chain lengths. However, while fatty acid methyl or ethyl esters are useful biodiesel produced commercially, fatty acid esters with branched-chain alcohol moieties have superior fuel properties. Crucially, this includes improved cold flow characteristics, as one of the major problems associated with biodiesel use is poor low-temperature flow properties. Hence, microbial production as a renewable, nontoxic and scalable method to produce fatty acid esters with branched-chain alcohol moieties from biomass is critical. We engineered Saccharomyces cerevisiae to produce fatty acid short- and branched-chain alkyl esters, including ethyl, isobutyl, isoamyl and active amyl esters using endogenously synthesized fatty acids and alcohols. Two wax ester synthase genes (ws2 and Maqu_0168 from Marinobacter sp.) were cloned and expressed. Both enzymes were found to catalyze the formation of fatty acid esters, with different alcohol preferences. To boost the ability of S. cerevisiae to produce the aforementioned esters, negative regulators of the INO1 gene in phospholipid metabolism, Rpd3 and Opi1, were deleted to increase flux towards fatty acyl-CoAs. In addition, five isobutanol pathway enzymes (Ilv2, Ilv5, Ilv3, Aro10, and Adh7) targeted into the mitochondria were overexpressed to enhance production of alcohol precursors. By combining these engineering strategies with high-cell-density fermentation, over 230 mg/L fatty acid short- and branched-chain alkyl esters were produced, which is the highest titer reported in yeast to date. In this work, we engineered the metabolism of S. cerevisiae to produce biodiesels in the form of fatty acid short- and branched-chain alkyl esters, including ethyl, isobutyl, isoamyl and active amyl esters. To our knowledge, this is the first report of the production of fatty acid isobutyl and active amyl esters in S. cerevisiae. Our findings will be useful for engineering S. cerevisiae strains toward high-level and sustainable biodiesel production.

Self-assembly modes of glycyrrhetinic acid esters in view of the crystal packing of related triterpene molecules.

PubMed

Langer, Dominik; Wicher, Barbara; Szczołko, Wojciech; Gdaniec, Maria; Tykarska, Ewa

2016-08-01

The crystal structures of three ester derivatives of glycyrrhetinic acid (GE) are reported. X-ray crystallography revealed that despite differences in the size of the ester substituents (ethyl, isopropyl and 2-morpholinoethyl) the scheme of molecular self-assembly is similar in all three cases but differs significantly from that observed in other known GE esters. According to our analysis, the two basic patterns of self-assembly of GE esters observed in their unsolvated crystals correspond to two distinct orientations of the ester groups relative to the triterpene backbone. Moreover, comparison of the self-assembly modes of GE esters in their unsolvated forms with the supramolecular organization of GE and carbenoxolone in their solvated crystals revealed that ester substituents replace solvent molecules hydrogen bonded to the COOH group at the triterpene skeleton, resulting in similar packing arrangements of these compounds.

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl and ethyl esters of fatty acids produced... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the...

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methyl and ethyl esters of fatty acids produced... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the...

Critical aggregates concentration of fatty esters present in biodiesel determined by turbidity and fluorescence.

PubMed

Froehner, Sandro; Sánez, Juan; Dombroski, Luiz Fernando; Gracioto, Maria Paula

2017-09-01

Biodiesel for combustible engine is available as mixture of fossil diesel and fatty esters obtained by transesterification of vegetable oils. The use of biodiesel reduces the amount of SO x , mainly. However, it was already observed that biodiesel has a different behavior in environment in cases of accidental spill and groundwater contamination. It was noticed that the biodegradation of hydrocarbons (cyclic and aliphatic) in the presence of biodiesel are speeded, although the mechanism is still unclear. Considering the chemical structure of fatty esters, it was investigated the formation of aggregates in water solution by fatty esters present in commercial biodiesel. In Brazil, biodiesel is composed by 95% of fossil diesel and 5% of fatty esters mixture. In this work, fatty esters were treated as neutral surfactant, i.e., it was treated as a molecule with polar and non-polar part. Turbidity and fluorescence were used to determine the critical aggregates concentration (CAC). Water solutions containing fatty esters were examined exploiting changes in turbidity and fluorescence intensity of pyrene. Abrupt changes were attributed to aggregates formation, following the same behavior of traditional amphiphilic compounds. It was determined the CAC for ethyl palmitate, ethyl stearate, ethyl oleate, and ethyl linoleate. The values of CAC for fatty esters varied from 1.91 to 4.27 μmol/L, while CAC for the mixture of esters (biodiesel) was 2.01 for methyl esters and 1.19 for ethyl esters, both prepared using soybean oil. The aggregates formation was also determined by fluorescence measurements considering the changes in intensity of peaks I and III of pyrene. Pyrene senses the changes in environment polarity. The values found of CAC by fluorescence for individual ethyl esters varied from 1.85 to 3.21 μmol/L, while mixtures of ethyl esters was 2.23 and 2.07 μmol/L for mixture of methyl esters. The results clearly showed that fatty esters form aggregates and might be responsible for speed degradation of compounds by accommodation of them in inner part of aggregates.

Separator for alkaline batteries and method of making same

NASA Technical Reports Server (NTRS)

Hoyt, H. E.; Pfluger, H. L. (Inventor)

1970-01-01

The preparation of membranes suitable for use as separators in concentrated alkaline battery cells by selective solvolysis of copolymers of methacrylate esters with acrylate esters followed by addition of a base and to the resultant products is described. The method of making copolymers by first copolymerizing a methacrylate ester (or esters) with a more readily hydrolyzable ester, followed by a selective saponification whereby the methacrylate ester moieties remain essentially intact and the readily hydrolyzable ester moiety is suponified and to the partial or complete neutralization of the relatively brittle copolymer acid with a base to make membranes which are sufficiently flexible in the dry state so that they may be wrapped around electrodes without damage by handling is described.

Engineering modular ester fermentative pathways in Escherichia coli.

PubMed

Layton, Donovan S; Trinh, Cong T

2014-11-01

Sensation profiles are observed all around us and are made up of many different molecules, such as esters. These profiles can be mimicked in everyday items for their uses in foods, beverages, cosmetics, perfumes, solvents, and biofuels. Here, we developed a systematic 'natural' way to derive these products via fermentative biosynthesis. Each ester fermentative pathway was designed as an exchangeable ester production module for generating two precursors- alcohols and acyl-CoAs that were condensed by an alcohol acyltransferase to produce a combinatorial library of unique esters. As a proof-of-principle, we coupled these ester modules with an engineered, modular, Escherichia coli chassis in a plug-and-play fashion to create microbial cell factories for enhanced anaerobic production of a butyrate ester library. We demonstrated tight coupling between the modular chassis and ester modules for enhanced product biosynthesis, an engineered phenotype useful for directed metabolic pathway evolution. Compared to the wildtype, the engineered cell factories yielded up to 48 fold increase in butyrate ester production from glucose. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Ultrastructure of the digestive tract of Gyliauchen nahaensis (Platyhelminthes, Digenea), an inhabitant of the hindgut of herbivorous fishes.

PubMed

Jones, M K; Hughes-Stamm, S R; East, R M; Cribb, T H

2000-12-01

Digenean parasites of vertebrates usually amplify the surface area of their gut by increasing the size of the absorptive caeca. Some members of the family Gyliauchenidae, however, have relatively small caeca but have a greatly expanded foregut. The morphology of the elongate gut of the digenean Gyliauchen nahaensis, an inhabitant of herbivorous fish of the family Siganidae, was examined by light and transmission electron microscopy. The extensive foregut, consisting of a mouth, pharynx, and esophagus, is lined with a syncytial tegument-like lining, which is connected to nucleated cell bodies sunken in the parenchyma. The apical cytoplasm in the mouth and anterior regions of the pharynx resembles that of the general body tegument, although some regional specialization is present. The lining of posterior regions of the pharynx is armed with large apical projections, which are thought to serve as filtration structures. The lining of the anterior and middle esophagus displays a peculiar form of surface amplification involving the formation of elongate flask-shaped invaginations of the apical cytoplasm. The cell bodies associated with these regions are rich in secretory vesicles and it is proposed that these regions of the esophagus are expanded to promote extracellular digestion. The posterior region of the esophagus lacks the invaginations of other esophageal regions, but displays instead large surface projections. The caeca consists of columnar cells lined by extensive apical microlamellae. The peculiar gut morphology of G. nahaensis, coupled with alterations in the arrangement of suckers, is interpreted to be an adaptation to the predominantly herbivorous diets of the definitive hosts.

Cobalt-catalyzed hydrogenation of esters to alcohols: unexpected reactivity trend indicates ester enolate intermediacy.

PubMed

Srimani, Dipankar; Mukherjee, Arup; Goldberg, Alexander F G; Leitus, Gregory; Diskin-Posner, Yael; Shimon, Linda J W; Ben David, Yehoshoa; Milstein, David

2015-10-12

The atom-efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious-metal-based catalysts, with few exceptions. Presented here is the first cobalt-catalyzed hydrogenation of esters to the corresponding alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Critical Involvement of Environmental Carbon Dioxide Fixation to Drive Wax Ester Fermentation in Euglena

PubMed Central

Nishio, Kazuki; Nakazawa, Masami; Nakamoto, Masatoshi; Okazawa, Atsushi; Kanaya, Shigehiko; Arita, Masanori

2016-01-01

Accumulation profiles of wax esters in Euglena gracilis Z were studied under several environmental conditions. The highest amount of total wax esters accumulated under hypoxia in the dark, and C28 (myristyl-myristate, C14:0-C14:0) was prevalent among all conditions investigated. The wax ester production was almost completely suppressed under anoxia in the light, and supplying exogenous inorganic carbon sources restored wax ester fermentation, indicating the need for external carbon sources for the wax ester fermentation. 13C-labeling experiments revealed specific isotopic enrichment in the odd-numbered fatty acids derived from wax esters, indicating that the exogenously-supplied CO2 was incorporated into wax esters via the propionyl-CoA pathway through the reverse tricarboxylic acid (TCA) cycle. The addition of 3-mercaptopicolinic acid, a phosphoenolpyruvate carboxykinase (PEPCK) inhibitor, significantly affected the incorporation of 13C into citrate and malate as the biosynthetic intermediates of the odd-numbered fatty acids, suggesting the involvement of PEPCK reaction to drive wax ester fermentation. Additionally, the 13C-enrichment pattern of succinate suggested that the CO2 assimilation might proceed through alternative pathways in addition to the PEPCK reaction. The current results indicate that the mechanisms of anoxic CO2 assimilation are an important target to reinforce wax ester fermentation in Euglena. PMID:27669566

Impact of thermooxidation of phytosteryl and phytostanyl fatty acid esters on cholesterol micellarization in vitro.

PubMed

Scholz, Birgit; Weiherer, Renate; Engel, Karl-Heinz

2017-09-01

The effects of thermooxidation of a phytosteryl/-stanyl and a phytostanyl fatty acid ester mixture on cholesterol micellarization were investigated using an in vitro digestion model simulating enzymatic hydrolysis by cholesterol esterase and subsequent competition of the liberated phytosterols/-stanols with cholesterol for incorporation into mixed micelles. As a first step, relationships between different doses of the ester mixtures and the resulting micellarized cholesterol were established. Subsequent subjection of the thermooxidized ester mixtures to the in vitro digestion model resulted in three principal observations: (i) thermal treatment of the ester mixtures led to substantial decreases of the intact esters, (ii) in vitro digestion of cholesterol in the presence of the thermooxidized ester mixtures resulted in significant increases of cholesterol micellarization, and (iii) the extents of the observed effects on cholesterol micellarization were strongly associated to the remaining contents of intact esters. The loss of efficacy to inhibit cholesterol micellarization due to thermally induced losses of intact esters corresponded to a loss of efficacy that would have been induced by an actual removal of these amounts of esters prior to the in vitro digestion. The obtained results suggest that in particular oxidative modifications of the fatty acid moieties might be responsible for the observed increases of cholesterol micellarization. Copyright © 2017 Elsevier Inc. All rights reserved.

Method for the determination of natural ester-type gum bases used as food additives via direct analysis of their constituent wax esters using high-temperature GC/MS.

PubMed

Tada, Atsuko; Ishizuki, Kyoko; Yamazaki, Takeshi; Sugimoto, Naoki; Akiyama, Hiroshi

2014-07-01

Natural ester-type gum bases, which are used worldwide as food additives, mainly consist of wax esters composed of long-chain fatty acids and long-chain fatty alcohols. There are many varieties of ester-type gum bases, and thus a useful method for their discrimination is needed in order to establish official specifications and manage their quality control. Herein is reported a rapid and simple method for the analysis of different ester-type gum bases used as food additives by high-temperature gas chromatography/mass spectrometry (GC/MS). With this method, the constituent wax esters in ester-type gum bases can be detected without hydrolysis and derivatization. The method was applied to the determination of 10 types of gum bases, including beeswax, carnauba wax, lanolin, and jojoba wax, and it was demonstrated that the gum bases derived from identical origins have specific and characteristic total ion chromatogram (TIC) patterns and ester compositions. Food additive gum bases were thus distinguished from one another based on their TIC patterns and then more clearly discriminated using simultaneous monitoring of the fragment ions corresponding to the fatty acid moieties of the individual molecular species of the wax esters. This direct high-temperature GC/MS method was shown to be very useful for the rapid and simple discrimination of varieties of ester-type gum bases used as food additives.

Method for the determination of natural ester-type gum bases used as food additives via direct analysis of their constituent wax esters using high-temperature GC/MS

PubMed Central

Tada, Atsuko; Ishizuki, Kyoko; Yamazaki, Takeshi; Sugimoto, Naoki; Akiyama, Hiroshi

2014-01-01

Natural ester-type gum bases, which are used worldwide as food additives, mainly consist of wax esters composed of long-chain fatty acids and long-chain fatty alcohols. There are many varieties of ester-type gum bases, and thus a useful method for their discrimination is needed in order to establish official specifications and manage their quality control. Herein is reported a rapid and simple method for the analysis of different ester-type gum bases used as food additives by high-temperature gas chromatography/mass spectrometry (GC/MS). With this method, the constituent wax esters in ester-type gum bases can be detected without hydrolysis and derivatization. The method was applied to the determination of 10 types of gum bases, including beeswax, carnauba wax, lanolin, and jojoba wax, and it was demonstrated that the gum bases derived from identical origins have specific and characteristic total ion chromatogram (TIC) patterns and ester compositions. Food additive gum bases were thus distinguished from one another based on their TIC patterns and then more clearly discriminated using simultaneous monitoring of the fragment ions corresponding to the fatty acid moieties of the individual molecular species of the wax esters. This direct high-temperature GC/MS method was shown to be very useful for the rapid and simple discrimination of varieties of ester-type gum bases used as food additives. PMID:25473499

The Role of Carbon in Grain Refinement of Cast CrFeCoNi High-Entropy Alloys

NASA Astrophysics Data System (ADS)

Liu, X. W.; Liu, L.; Liu, G.; Wu, X. X.; Lu, D. H.; Yao, J. Q.; Jiang, W. M.; Fan, Z. T.; Zhang, W. B.

2018-03-01

As a promising engineering material, high-entropy alloys (HEAs) CrFeCoNi system has attracted extensive attention worldwide. Their cast alloys are of great importance because of their great formability of complex components, which can be further improved through the transition of the columnar to equiaxed grains and grain refinement. In the current work, the influence of C contents on the grain structures and mechanical properties of the as-cast high-entropy alloy CrFeCoNi was chosen as the target and systematically studied via a hybrid approach of the experiments and thermodynamic calculations. The alloys with various C additions were prepared by arc melting and drop cast. The as-cast macrostructure and microstructure were characterized using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The cast HEAs transform from coarse columnar grains into equiaxed grains with the C level increased to ≥ 2 at. pct and the size of equiaxed grains is further decreased with the increasing C addition. It is revealed that the interdendritic segregation of Cr and C results in grain boundary precipitation of M23C6 carbides. The grain refinement is attributed to the additional constitutional supercoiling from the C addition. The yield stress and tensile strength at room temperature are improved due to the transition of columnar to equiaxed grains and grain refinement.

Evaluation of modified crystal violet chromoendoscopy procedure using new mucosal pit pattern classification for detection of Barrett's dysplastic lesions.

PubMed

Yuki, T; Amano, Y; Kushiyama, Y; Takahashi, Y; Ose, T; Moriyama, I; Fukuhara, H; Ishimura, N; Koshino, K; Furuta, K; Ishihara, S; Adachi, K; Kinoshita, Y

2006-05-01

Pit pattern diagnosis is important for endoscopic detection of dysplastic Barrett's lesions, though using magnification endoscopy can be difficult and laborious. We investigated the usefulness of a modified crystal violet chromoendoscopy procedure and utilised a new pit pattern classification for diagnosis of dysplastic Barrett's lesions. A total of 1,030 patients suspected of having a columnar lined oesophagus were examined, of whom 816 demonstrated a crystal violet-stained columnar lined oesophagus. The early group of patients underwent 0.05% crystal violet chromoendoscopy, while the later group was examined using 0.03% crystal violet with 3.0% acetate. A targeted biopsy of the columnar lined oesophagus was performed using crystal violet staining after making a diagnosis of closed or open type pit pattern with a newly proposed system of classification. The relationship between type of pit pattern and histologically identified dysplastic Barrett's lesions was evaluated. Dysplastic Barrett's lesions were identified in biopsy samples with an open type pit pattern with a sensitivity of 96.0%. Further, Barrett's mucosa with the intestinal predominant mucin phenotype was closely associated with the open type pit pattern (sensitivity 81.9%, specificity 95.6%). The new pit pattern classification for diagnosis of Barrett's mucosa was found to be useful for identification of cases with dysplastic lesions and possible malignant potential using a crystal violet chromoendoscopic procedure.

Columnar processing in primate pFC: evidence for executive control microcircuits.

PubMed

Opris, Ioan; Hampson, Robert E; Gerhardt, Greg A; Berger, Theodore W; Deadwyler, Sam A

2012-12-01

A common denominator for many cognitive disorders of human brain is the disruption of neural activity within pFC, whose structural basis is primarily interlaminar (columnar) microcircuits or "minicolumns." The importance of this brain region for executive decision-making has been well documented; however, because of technological constraints, the minicolumnar basis is not well understood. Here, via implementation of a unique conformal multielectrode recording array, the role of interlaminar pFC minicolumns in the executive control of task-related target selection is demonstrated in nonhuman primates performing a visuomotor DMS task. The results reveal target-specific, interlaminar correlated firing during the decision phase of the trial between multielectrode recording array-isolated minicolumnar pairs of neurons located in parallel in layers 2/3 and layer 5 of pFC. The functional significance of individual pFC minicolumns (separated by 40 μm) was shown by reduced correlated firing between cell pairs within single minicolumns on error trials with inappropriate target selection. To further demonstrate dependence on performance, a task-disrupting drug (cocaine) was administered in the middle of the session, which also reduced interlaminar firing in minicolumns that fired appropriately in the early (nondrug) portion of the session. The results provide a direct demonstration of task-specific, real-time columnar processing in pFC indicating the role of this type of microcircuit in executive control of decision-making in primate brain.

Hierarchical Self-Organization of Perylene Bisimides into Supramolecular Spheres and Periodic Arrays Thereof.

PubMed

Sahoo, Dipankar; Peterca, Mihai; Aqad, Emad; Partridge, Benjamin E; Heiney, Paul A; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Percec, Virgil

2016-11-09

Perylene bisimide derivatives (PBIs) are known to form only columnar or lamellar assemblies. There is no known example of a PBI self-assembling into a supramolecular sphere. Therefore, periodic and quasiperiodic arrays generated from spherical assemblies produced from PBIs are also not known. Here, a PBI functionalized at its imide groups with a second generation self-assembling dendron is reported to self-assemble into supramolecular spheres. These spheres self-organize in a body-centered cubic (BCC) periodic array, rarely encountered for self-assembling dendrons but often encountered in block copolymers. These supramolecular spheres also assemble into a columnar hexagonal array in which the supramolecular columns are unexpectedly and unprecedentedly made from spheres. At lower temperature, two additional columnar hexagonal phases consisting of symmetric and asymmetric tetrameric crowns of PBI are observed. Structural and retrostructural analysis via X-ray diffraction (XRD), molecular modeling, molecular simulation, and solid state NMR suggests that inversion of the symmetric tetrameric crowns at high temperature mediates their transformation into supramolecular spheres. The tetrameric crowns of PBIs are able to form an isotropic sphere in the cubic phase due to rapid molecular motion at high temperature, unobservable by XRD but demonstrated by solid state NMR studies. This mechanism of hierarchical self-organization of PBI into supramolecular spheres is most probably general and can be applied to other related planar molecules to generate new functions.

Crystalline Silicates in Comets: Modeling Irregularly-Shaped Forsterite Crystals and Its Implications on Condensation Conditions

NASA Technical Reports Server (NTRS)

Wooden, Diane H.; Lindsay, Sean S.

2011-01-01

Crystalline silicates in comets are a product of the condensation in the hot inner regions (T > or approx. equals 1400 K [1]) of our proto-planetary disk or annealing at somewhat lower temperatures (T > or approx. equals 1000-1200 K) [2, 3, 4] in shocks coupled with disk evolutionary processes that include radial transport of crystals from their formation locations out to the cold outer regions where comet nuclei formed. The grain shape of forsterite (crystals) could be indicative of their formation pathways at high temperatures through vapor-solid condensation or at lower temperatures through vapor-liquid-solid formation and growth [5, 6, 7]. Experiments demonstrate that crystals that formed from a rapidly cooled highly supersaturated silicate vapor are characterized by bulky, platy, columnar/needle and droplet shapes for values of temperature and supersaturation, T and sigma, of 1000-1450 C and < 97, 700-1000 C and 97-161, 580-820 C and 131-230, and <500 C and > 230, respectively [7]. The experimental columnar/needle shapes, which form by vapor-liquid-solid at lower temperatures (<820 C), are extended stacks of plates, where the extension is not correlated with an axial direction: columnar/needles may be extended in the c-axis or a-axis direction, can change directions, and/or are off-kilter or a bit askew extending in a combination of the a- and c-axis direction.

Columnar-Structured Mg-Al-Spinel Thermal Barrier Coatings (TBCs) by Suspension Plasma Spraying (SPS)

NASA Astrophysics Data System (ADS)

Schlegel, N.; Ebert, S.; Mauer, G.; Vaßen, R.

2015-01-01

The suspension plasma spraying (SPS) process has been developed to permit the feeding of sub-micrometer-sized powder into the plasma plume. In contrast to electron beam-physical vapor deposition and plasma spray-physical vapor deposition, SPS enables the cost-efficient deposition of columnar-structured coatings. Due to their strain tolerance, these coatings play an important role in the field of thermal barrier coatings (TBCs). In addition to the cost-efficient process, attention was turned to the TBC material. Nowadays, yttria partially stabilized zirconia (YSZ) is used as standard TBC material. However, its long-term application at temperatures higher than 1200 °C is problematic. At these high temperatures, phase transitions and sintering effects lead to the degradation of the TBC system. To overcome those deficits of YSZ, Mg-Al-spinel was chosen as TBC material. Even though it has a lower melting point (~2135 °C) and a higher thermal conductivity (~2.5 W/m/K) than YSZ, Mg-Al-spinel provides phase stability at high temperatures in contrast to YSZ. The Mg-Al-spinel deposition by SPS resulted in columnar-structured coatings, which have been tested for their thermal cycling lifetime. Furthermore, the influence of substrate cooling during the spraying process on thermal cycling behavior, phase composition, and stoichiometry of the Mg-Al-spinel has been investigated.

Hedgehog signaling regulates FOXA2 in esophageal embryogenesis and Barrett’s metaplasia

PubMed Central

Wang, David H.; Tiwari, Anjana; Kim, Monica E.; Clemons, Nicholas J.; Regmi, Nanda L.; Hodges, William A.; Berman, David M.; Montgomery, Elizabeth A.; Watkins, D. Neil; Zhang, Xi; Zhang, Qiuyang; Jie, Chunfa; Spechler, Stuart J.; Souza, Rhonda F.

2014-01-01

Metaplasia can result when injury reactivates latent developmental signaling pathways that determine cell phenotype. Barrett’s esophagus is a squamous-to-columnar epithelial metaplasia caused by reflux esophagitis. Hedgehog (Hh) signaling is active in columnar-lined, embryonic esophagus and inactive in squamous-lined, adult esophagus. We showed previously that Hh signaling is reactivated in Barrett’s metaplasia and overexpression of Sonic hedgehog (SHH) in mouse esophageal squamous epithelium leads to a columnar phenotype. Here, our objective was to identify Hh target genes involved in Barrett’s pathogenesis. By microarray analysis, we found that the transcription factor Foxa2 is more highly expressed in murine embryonic esophagus compared with postnatal esophagus. Conditional activation of Shh in mouse esophageal epithelium induced FOXA2, while FOXA2 expression was reduced in Shh knockout embryos, establishing Foxa2 as an esophageal Hh target gene. Evaluation of patient samples revealed FOXA2 expression in Barrett’s metaplasia, dysplasia, and adenocarcinoma but not in esophageal squamous epithelium or squamous cell carcinoma. In esophageal squamous cell lines, Hh signaling upregulated FOXA2, which induced expression of MUC2, an intestinal mucin found in Barrett’s esophagus, and the MUC2-processing protein AGR2. Together, these data indicate that Hh signaling induces expression of genes that determine an intestinal phenotype in esophageal squamous epithelial cells and may contribute to the development of Barrett’s metaplasia. PMID:25083987

Facilitation and Restoration of Cognitive Function in Primate Prefrontal Cortex by a Neuroprosthesis that Utilizes Minicolumn-Specific Neural Firing

PubMed Central

Hampson, Robert E.; Gerhardt, Greg A.; Marmarelis, Vasilis; Song, Dong; Opris, Ioan; Santos, Lucas; Berger, Theodore W.; Deadwyler, Sam A.

2012-01-01

Problem addressed Maintenance of cognitive control is a major concern for many human disease condition, therefore a major goal of human neuroprosthetics is to facilitate and/or recover cognitive function when such circumstances impair appropriate decision making. Methodology Nonhuman primates trained to perform a delayed match to sample (DMS) were employed to record mini-columnar activity in the prefrontal cortex (PFC) via custom designed conformal multielectrode arrays that provided inter-laminar recordings from neurons in PFC layer 2/3 and layer 5. Such recordings were analyzed via a previously demonstrated nonlinear multi-input multi-output (MIMO) neuroprosthesis in rodents, which extracted and characterized multi-columnar firing patterns during DMS performance. Results The MIMO model verified that the conformal recorded individual PFC minicolumns responded to entrained target selections in patterns critical for successful DMS performance. This allowed substitution of task-related layer 5 neuron firing patterns with electrical stimulation in the same recording regions during columnar transmission from layer 2/3 at the time of target selection. Such stimulation facilitated normal task performance, but more importantly, recovered performance when applied as a neuroprosthesis following pharmacological disruption of decision making in the same task. Significance and potential impact These findings provide the first successful application of a neuroprosthesis in primate brain designed specifically to restore or repair disrupted cognitive function. PMID:22976769

Interfacial stability of CoSi2/Si structures grown by molecular beam epitaxy

NASA Technical Reports Server (NTRS)

George, T.; Fathauer, R. W.

1992-01-01

The stability of CoSi2/Si interfaces was examined in this study using columnar silicide structures grown on (111) Si substrates. In the first set of experiments, Co and Si were codeposited using MBE at 800 C and the resulting columnar silicide layer was capped by epitaxial Si. Deposition of Co on the surface of the Si capping layer at 800 C results in the growth of the buried silicide columns. The buried columns grow by subsurface diffusion of the deposited Co, suppressing the formation of surface islands of CoSi2. The column sidewalls appear to be less stable than the top and bottom interfaces, resulting in preferential lateral growth and ultimately in the coalescence of the columns to form a continuous buried CoSi2 layer. In the second set of experiments, annealing of a 250 nm-thick buried columnar layer at 1000 C under a 100 nm-thick Si capping layer results in the formation of a surface layer of CoSi2 with a reduction in the sizes of the CoSi2 columns. For a sample having a thicker Si capping layer the annealing leads to Ostwald ripening producing buried equiaxed columns. The high CoSi2/Si interfacial strain could provide the driving force for the observed behavior of the buried columns under high-temperature annealing.

Hyperplasia of the submucosal glands of the columnar-lined oesophagus.

PubMed

Lörinc, Ester; Öberg, Stefan

2015-04-01

To evaluate the presence of multi-layered epithelium (ME) and to compare the distribution, size and morphology of the oesophageal submucosal glands (SMG) beneath reflux exposed metaplastic columnar mucosa with those of normal squamous epithelium in patients with columnar-lined oesophagus (CLO). In eight oesophageal resection specimens, the SMG of the metaplastic segments were significantly larger than those in the squamous segments of patients with CLO (0.81 versus 0.56 mm(2) , P = <0.001). There was an accumulation of SMG close to the neosquamocolumnar junction (NSCJ), as indicated by a higher median frequency of SMG (0.080 SMG/mm) compared with that of the squamous (0.013 SMG/mm) and metaplastic segments (0.031 SMG/mm) (P = 0.022). The frequency of ME was significantly higher in the metaplastic compared with the normal squamous segments (1/158 mm and 1/341 mm, respectively, P = 0.028) and ME was found almost exclusively (96%) in direct connection with the excretory ducts of SMG. Hyperplasia of SMG in the metaplastic segment, accumulation of SMG near the NSCJ, the presence of ME in connection with the excretory ducts of SMG and metaplasia are all reflux-induced morphological changes, possibly induced by stimulation of progenitors in the excretory ducts of the SMG. © 2014 John Wiley & Sons Ltd.

The Role of Carbon in Grain Refinement of Cast CrFeCoNi High-Entropy Alloys

NASA Astrophysics Data System (ADS)

Liu, X. W.; Liu, L.; Liu, G.; Wu, X. X.; Lu, D. H.; Yao, J. Q.; Jiang, W. M.; Fan, Z. T.; Zhang, W. B.

2018-06-01

As a promising engineering material, high-entropy alloys (HEAs) CrFeCoNi system has attracted extensive attention worldwide. Their cast alloys are of great importance because of their great formability of complex components, which can be further improved through the transition of the columnar to equiaxed grains and grain refinement. In the current work, the influence of C contents on the grain structures and mechanical properties of the as-cast high-entropy alloy CrFeCoNi was chosen as the target and systematically studied via a hybrid approach of the experiments and thermodynamic calculations. The alloys with various C additions were prepared by arc melting and drop cast. The as-cast macrostructure and microstructure were characterized using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The cast HEAs transform from coarse columnar grains into equiaxed grains with the C level increased to ≥ 2 at. pct and the size of equiaxed grains is further decreased with the increasing C addition. It is revealed that the interdendritic segregation of Cr and C results in grain boundary precipitation of M23C6 carbides. The grain refinement is attributed to the additional constitutional supercoiling from the C addition. The yield stress and tensile strength at room temperature are improved due to the transition of columnar to equiaxed grains and grain refinement.

A Columnar Storage Strategy with Spatiotemporal Index for Big Climate Data

NASA Astrophysics Data System (ADS)

Hu, F.; Bowen, M. K.; Li, Z.; Schnase, J. L.; Duffy, D.; Lee, T. J.; Yang, C. P.

2015-12-01

Large collections of observational, reanalysis, and climate model output data may grow to as large as a 100 PB in the coming years, so climate dataset is in the Big Data domain, and various distributed computing frameworks have been utilized to address the challenges by big climate data analysis. However, due to the binary data format (NetCDF, HDF) with high spatial and temporal dimensions, the computing frameworks in Apache Hadoop ecosystem are not originally suited for big climate data. In order to make the computing frameworks in Hadoop ecosystem directly support big climate data, we propose a columnar storage format with spatiotemporal index to store climate data, which will support any project in the Apache Hadoop ecosystem (e.g. MapReduce, Spark, Hive, Impala). With this approach, the climate data will be transferred into binary Parquet data format, a columnar storage format, and spatial and temporal index will be built and attached into the end of Parquet files to enable real-time data query. Then such climate data in Parquet data format could be available to any computing frameworks in Hadoop ecosystem. The proposed approach is evaluated using the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate reanalysis dataset. Experimental results show that this approach could efficiently overcome the gap between the big climate data and the distributed computing frameworks, and the spatiotemporal index could significantly accelerate data querying and processing.

Methods of making organic compounds by metathesis

DOEpatents

Abraham, Timothy W.; Kaido, Hiroki; Lee, Choon Woo; Pederson, Richard L.; Schrodi, Yann; Tupy, Michael John

2015-09-01

Described are methods of making organic compounds by metathesis chemistry. The methods of the invention are particularly useful for making industrially-important organic compounds beginning with starting compositions derived from renewable feedstocks, such as natural oils. The methods make use of a cross-metathesis step with an olefin compound to produce functionalized alkene intermediates having a pre-determined double bond position. Once isolated, the functionalized alkene intermediate can be self-metathesized or cross-metathesized (e.g., with a second functionalized alkene) to produce the desired organic compound or a precursor thereto. The method may be used to make bifunctional organic compounds, such as diacids, diesters, dicarboxylate salts, acid/esters, acid/amines, acid/alcohols, acid/aldehydes, acid/ketones, acid/halides, acid/nitriles, ester/amines, ester/alcohols, ester/aldehydes, ester/ketones, ester/halides, ester/nitriles, and the like.

Retinol esterification in bovine retinal pigment epithelium: reversibility of lecithin:retinol acyltransferase.

PubMed Central

Saari, J C; Bredberg, D L; Farrell, D F

1993-01-01

Esterification of all-trans-retinol is a key reaction of the vertebrate visual cycle, since it produces an insoluble, relatively non-toxic, form of the vitamin for storage and supplies substrate for the isomerization reaction. CoA-dependent and -independent pathways have been described for retinol esterification in retinal pigment epithelium (RPE). The CoA-independent reaction, catalysed by lecithin:retinol acyltransferase (LRAT) was examined in more detail in this study. Addition of retinol to RPE microsomes results in a burst of retinyl ester synthesis, followed by a rapid apparent cessation of the reaction. However, [3H]retinol, added when retinyl ester synthesis has apparently ceased, is rapidly incorporated into retinyl ester without a net increase in the amount of ester. The specific radioactivities of [3H]retinol and [3H]retinyl ester reach the same value. [14C]Palmitate from palmitoyl-CoA is incorporated into preexisting retinyl ester in the absence of net ester synthesis, too. These exchange reactions suggest that the reaction has reached equilibrium at the plateau of the progress curve and that only the accumulation of retinyl ester, and not its synthesis, has stopped during this phase of the reaction. Studies with geometrical isomers of retinol revealed that the rate of exchange of all-trans-retinol with all-trans-retinyl esters was about 6 times more rapid than exchange of 11-cis-retinol with 11-cis-retinyl ester. This is the first demonstration of the reversibility of LRAT and the first example of stereospecificity of retinyl ester synthesis in the visual system. Reversal of the LRAT reaction could contribute to the mobilization of 11-cis-retinol from 11-cis-retinyl ester pools. Images Figure 3 PMID:8489497

Analysis of methyloxime derivatives of intact esters of testosterone and boldenone in equine plasma using ultra high performance liquid chromatography tandem mass spectrometry.

PubMed

Gray, Bobby P; Teale, Phil; Pearce, Clive M

2011-04-01

Analysis of equine plasma samples to detect the abuse of anabolic steroids can be complicated when the parent steroid is endogenous to the animal. Anabolic steroids are usually administered intramuscularly as synthetic esters and therefore detection of the exogenous esters provides unequivocal proof of illegal administration. An ultra high performance liquid chromatography tandem mass spectrometric (UPLC-MSMS) method for the analysis of esters of testosterone (propionate, phenylpropionate, isocaproate, and decanoate) and boldenone (undecylenate) in equine plasma has been developed. Esters were extracted from equine plasma using a mixture of hexane and ethyl acetate and treated with methoxyamine hydrochloride to form methyloxime derivatives. Metenolone enanthate was used as an internal standard. After chromatographic separation, the derivatized steroid esters were quantified using selected reaction monitoring (SRM). The limit of detection for all of the steroid esters, based on a signal to noise ratio (S/N) of 3:1, was 1-3 pg/mL. The lower limit of quantification (LLOQ) for the all of the steroid esters was 5 pg/mL when 2 mL of plasma was extracted. Recovery of the steroid esters was 85-97% for all esters except for testosterone decanoate which was recovered at 62%. The intra-day coefficient of variation (CV) for the analysis of plasma quality control (QC) samples was less than 9.2% at 40 pg/mL and less than 6.0% at 400 pg/mL. The developed assay was used to successfully confirm the presence of intact testosterone esters in equine plasma samples following intramuscular injection of Durateston® (mixed testosterone esters). Copyright © 2011 John Wiley & Sons, Ltd.

N-Heterocyclic carbene-catalyzed direct cross-aza-benzoin reaction: Efficient synthesis of α-amino-β-keto esters.

PubMed

Uno, Takuya; Kobayashi, Yusuke; Takemoto, Yoshiji

2012-01-01

An efficient catalytic synthesis of α-amino-β-keto esters has been newly developed. Cross-coupling of various aldehydes with α-imino ester, catalyzed by N-heterocyclic carbene, leads chemoselectively to α-amino-β-keto esters in moderate to good yields with high atom efficiency. The reaction mechanism is discussed, and it is proposed that the α-amino-β-keto esters are formed under thermodynamic control.

Multi residue screening of intact testosterone esters and boldenone undecylenate in bovine hair using liquid chromatography electrospray tandem mass spectrometry.

PubMed

Nielen, Michel W F; Lasaroms, Johan J P; Mulder, Patrick P J; Van Hende, Johan; van Rhijn, J Hans A; Groot, Maria J

2006-01-02

The abuse of esters of natural androgenic steroids in cattle fattening and sports is hard to control via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously present in urine. In veterinary control strange findings of 17beta-testosterone and 17alpha-testosterone in urine are often ignored because of the lack of statistically sound reference data of naturally occurring levels. An interesting alternative for inconclusive urine analyses in veterinary control can be provided by the analysis of the administered steroids themselves, i.e. the analysis of intact steroid esters in hair. Unfortunately, the analysis of intact steroid esters is complicated not only by the vulnerability of the esters which precludes alkaline hydrolysis of the hair, but also by the wide polarity range of short and long-chain esters yielding very poor recoveries for either the one or the other. In this study, a multi-steroid esters LC/MS/MS screening method is presented for trace analysis of the synthetic intact esters of 17beta-testosterone and the undecylenate ester of 17beta-boldenone in bovine hair. The method, requiring only 200 mg of pulverised hair, features a mild digestion procedure using tris(2-carboxyethyl)phosphine hydrochloride (TCEP) and the use of four deuterium-labelled steroid esters as internal standards covering the wide polarity range of the analytes. In spiked hair samples for most of the analytes the limit of detection and the accuracy using isotope dilution were 2-5 ng/g and 97-105%, respectively. The applicability was demonstrated using hair samples from a controlled experiment in which six bovines were injected intramuscularly with two different doses of two commercial mixtures of testosterone esters, and with two different doses of boldenone undecylenate. Depending on the dose all administered testosterone- and boldenone esters were found to be incorporated in bovine hair following a single intramuscular injection, except testosterone propionate which dose might have been too low.

40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and.... (1) The chemical substances identified generically as alkenedioic acid, dialkyl ester, reaction...

40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125 Section... Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and.... (1) The chemical substances identified generically as alkenedioic acid, dialkyl ester, reaction...

Ethyl ester formation is enhanced by ethanol addition in mini Swiss cheese with and without added propionibacteria.

PubMed

Thierry, Anne; Maillard, Marie-Bernadette; Richoux, Romain; Lortal, Sylvie

2006-09-06

Esters are important contributors to cheese flavor, but their mechanisms of synthesis in cheese are largely unknown. This study aimed to determine whether ethanol concentration limits the formation of ethyl esters in cheese. Mini Swiss cheeses were manufactured with (E) or without (C) the addition of ethanol to cheese milk. Ethanol concentrations (enzymatic analysis) were 64 +/- 17 and 330 +/- 82 microg g(-1), respectively, in C and E cheeses. E cheeses also contained 5.4 +/- 2.3 times more of the five ethyl esters quantified than C cheeses, regardless of the concentrations of esters in C cheeses (range 1-128 ng g(-1)). Furthermore, the presence of propionibacteria added as acid-producing secondary starters was associated with greater concentrations of esters, due to the increase in acid concentrations that propionibacteria induced and/or to an involvement of propionibacteria enzymes in ester synthesis. This study demonstrates that ethanol is the limiting factor of ethyl ester synthesis in Swiss cheese.

Synthesis of TMP-ester biolubricant basestock from palm stearin fatty acids

NASA Astrophysics Data System (ADS)

Fadzel, Fatimatuzzahraa Mohd; Salimon, Jumat; Derawi, Darfizzi

2018-04-01

A potential biolubricant; TMP-ester was produced via esterification of fatty acids (FA) from palm stearin (PS) with trimethylolpropane (TMP). The synthesis was conducted at four conditions; temperature, time, molar ratio of FA:TMP and H2SO4 as catalyst (by percent based on the weight of FA and TMP) that are 150 °C, 2 hours, 4:1 and 1% of H2SO4 respectively. The composition of ester produced was determined using gas chromatography (GC-FID). The presence of ester group was confirmed by the means of FTIR by the existence of strong carboxyl band of ester, v(C=O) at 1746cm-1 and 1H and 13C NMR spectroscopy shows the chemical shift, δ of ester, C=O at 2.27-2.31 ppm and 173.45 ppm accordingly. From the esterification reaction, 95% product of TMP-ester was formed. The thermal and oxidative stability of TMP-ester is 200°C.

Asymmetric homologation of boronic esters bearing azido and silyloxy substituents.

PubMed

Singh, R P; Matteson, D S

2000-10-06

In the asymmetric homologation of boronic esters with a (dihalomethyl)lithium, substituents that can bind metal cations tend to interfere. Accordingly, we undertook the introduction of weakly basic oxygen and nitrogen substituents into boronic esters in order to maximize the efficiency of multistep syntheses utilizing this chemistry. Silyloxy boronic esters cannot be made efficiently by direct substitution, but a (hydroxymethyl)boronic ester has been silylated in the usual manner. Conversion of alpha-halo boronic esters to alpha-azido boronic esters has been carried out with sodium azide and a tetrabutylammonium salt as phase-transfer catalyst in a two-phase system with water and either nitromethane or ethyl acetate. These are safer solvents than the previously used dichloromethane, which can form an explosive byproduct with azide ion. Boronic esters containing silyloxy or alkoxy and azido substituents have been shown to react efficiently with (dihalomethyl)lithiums, resulting in efficient asymmetric insertion of the halomethyl group into the carbon-boron bond.

Flat Epithelial Atypia of the Breast.

PubMed

Collins, Laura C

2009-06-01

Lesions of the breast characterized by enlarged terminal duct lobular units lined by columnar epithelial cells are being encountered increasingly in breast biopsy specimens. Some of these lesions feature cuboidal to columnar epithelial cells in which the lining cells exhibit cytologic atypia. The role of these lesions (recently designated "flat epithelial atypia" [FEA]) in breast tumor progression is still emerging. FEA commonly coexists with well-developed examples of atypical ductal hyperplasia, low-grade ductal carcinoma in situ, lobular neoplasia, and tubular carcinoma. These findings and those of recent genetic studies suggest that FEA is a neoplastic lesion that may represent a precursor to or the earliest morphologic manifestation of ductal carcinoma in situ. Additional studies are needed to better understand the biologic nature and clinical significance of these lesions. Copyright © 2009 Elsevier Inc. All rights reserved.

Method and apparatus for calibrating the ionosphere and application to surveillance of geophysical events

NASA Technical Reports Server (NTRS)

Macdoran, P. F. (Inventor)

1984-01-01

The columnar electron content of the ionosphere between a spacecraft and a receiver is measured in realtime by cross correlating two coherently modulated signals transmitted at different frequencies (L1,L2) from the spacecraft to the receiver using a cross correlator. The time difference of arrival of the modulated signals is proportional to electron content of the ionosphere. A variable delay is adjusted relative to a fixed delay in the respective channels (L1,L2) to produce a maximum at the cross correlator output. The difference in delay required to produce this maximum is a measure of the columnar electron content of the ionosphere. A plurality of monitoring stations and spacecraft (Global Positioning System satellites) are employed to locate any terrestrial event that produces an ionospheric disturbance.

Summertime Dust Devil

NASA Technical Reports Server (NTRS)

2003-01-01

MGS MOC Release No. MOC2-464, 26 August 2003

Dust devils are spinning, columnar vortices of air that move across a landscape, picking up dust as they go. They are common occurrences during summer on Mars. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image, acquired during northern summer, shows a dust devil in the Phlegra region of Mars near 32.0oN, 182.1oW. Sunlight illuminates the scene from the lower left; the dust devil is casting a columnar shadow toward the upper right. Some dust devils on Mars make streaks as they disrupt the fine coating of dust on the surface--but others do not make streaks. This one did not make a streak. The view shown here is 3 km (1.9 mi) wide.

Multiple-layered effective medium approximation approach to modeling environmental effects on alumina passivated highly porous silicon nanostructured thin films measured by in-situ Mueller matrix ellipsometry

NASA Astrophysics Data System (ADS)

Mock, Alyssa; Carlson, Timothy; VanDerslice, Jeremy; Mohrmann, Joel; Woollam, John A.; Schubert, Eva; Schubert, Mathias

2017-11-01

Optical changes in alumina passivated highly porous silicon slanted columnar thin films during controlled exposure to toluene vapor are reported. Electron-beam evaporation glancing angle deposition and subsequent atomic layer deposition are utilized to deposit alumina passivated nanostructured porous silicon thin films. In-situ Mueller matrix generalized spectroscopic ellipsometry in an environmental cell is then used to determine changes in optical properties of the nanostructured thin films by inspection of individual Mueller matrix elements, each of which exhibit sensitivity to adsorption. The use of a multiple-layered effective medium approximation model allows for accurate description of the inhomogeneous nature of toluene adsorption onto alumina passivated highly porous silicon slanted columnar thin films.

Microwave nonlinearity and photoresponse of superconducting resonators with columnar defect micro-channels

NASA Astrophysics Data System (ADS)

Remillard, S. K.; Kirkendall, D.; Ghigo, G.; Gerbaldo, R.; Gozzelino, L.; Laviano, F.; Yang, Z.; Mendelsohn, N. A.; Ghamsari, B. G.; Friedman, B.; Jung, P.; Anlage, S. M.

2014-09-01

Micro-channels of nanosized columnar tracks were planted by heavy-ion irradiation into superconducting microwave microstrip resonators that were patterned from YBa2Cu3O7 - x thin films on LaAlO3 substrates. Three different ion fluences were used, producing different column densities, with each fluence having a successively greater impact on the microwave nonlinearity of the device, as compared to a control sample. Photoresponse (PR) images made with a 638 nm rastered laser beam revealed that the channel is a location of enhanced PR and a hot spot for the generation of intermodulation distortion. The microwave PR technique was also advanced in this work by investigating the role of coupling strength on the distribution of PR between inductive and resistive components.

Insertable fluid flow passage bridgepiece and method

DOEpatents

Jones, Daniel O.

2000-01-01

A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.

40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

Code of Federal Regulations, 2010 CFR

2010-07-01

... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

40 CFR 721.2950 - Carboxylic acid glycidyl esters.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Carboxylic acid glycidyl esters. 721... Substances § 721.2950 Carboxylic acid glycidyl esters. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as carboxylic acid glycidyl ester...

Enzymatic Synthesis of Glyserol-Coconut Oil Fatty Acid and Glycerol-Decanoic Acis Ester as Emulsifier and Antimicrobial Agents Using Candida rugosa Lipase EC 3.1.1.3

NASA Astrophysics Data System (ADS)

Handayani, Sri; Putri, Ayu Tanissa Tamara; Setiasih, Siswati; Hudiyono, Sumi

2018-01-01

In this research, enzymatic esterification was carried out between glycerol and fatty acid from coconut oil and decanoic acid using n-hexane as solvent. In this reaction Candida rugosa lipase was used as biocatalyst. Optimization esterification reaction was carried out for parameter of the substrate ratio. The mmol ratio between fatty acid and glycerol were used are 1:1, 1:2, 1:3, and 1: 4. The highest conversion percentage obtained at the mole ratio of 1: 4 with the value of 78.5% for the glycerol-decanoic acid ester and 55.4% for the glycerol coconut oil fatty acid ester. Esterification products were characterized by FT-IR. The FT-IR spectrum showed that the ester bond was formed as indicated by the wave number 1750-1739 cm-1. The esterification products were then examined by simple emulsion test and was proved to be an emulsifier. The glycerol-coconut oil fatty acid ester produced higher stability emulsion compare with glycerol decanoic ester. The antimicrobial activity assay using disc diffusion method showed that both glycerol-coconut oil fatty acid ester and glycerol-decanoic ester had the ability inhibiting the growth of Propionibacterium acnes and Staphylococcus epidermidis. Glycerol-decanoic ester shows higher antimicrobial activity than glycerol-coconut oil fatty acid ester.

Chemical and physical analyses of wax ester properties

PubMed Central

Patel, Sejal; Nelson, Dennis R.; Gibbs, Allen G.

2001-01-01

Wax esters are major constituents of the surface lipids in many terrestrial arthropods, but their study is complicated by their diversity. We developed a procedure for quantifying isomers in mixtures of straight-chain saturated and unsaturated wax esters having the same molecular weights, using single-ion monitoring of the total ion current data from gas chromatography-mass spectrometry. We examined the biological consequences of structural differences by measuring the melting temperatures, Tm, of >60 synthetic wax esters, containing 26–48 carbon atoms. Compounds containing saturated alcohol and acid moieties melted at 38–73°C. The main factor affecting Tm was the total chain length of the wax ester, but the placement of the ester bond also affected Tm. Insertion of a double bond into either the alcohol or acid moiety decreased Tm by ∼30°C. Simple mixtures of wax esters with n-alkanes melted several °C lower than predicted from the melting points of the component lipids. Our results indicate that the wax esters of primary alcohols that are most typically found on the cuticle of terrestrial arthropods occur in a solid state under physiological conditions, thereby conferring greater waterproofing. Wax esters of secondary alcohols, which occur on melanopline grasshoppers, melted >60°C below primary esters of the same molecular weight and reduced Tm of the total surface lipids to environmental values. PMID:15455064

Synthesis and amphiphilic properties of decanoyl esters of tri- and tetraethylene glycol.

PubMed

Zhu, Ying; Molinier, Valérie; Queste, Sébastien; Aubry, Jean-Marie

2007-08-15

Well-defined decanoyl triethylene glycol ester and decanoyl tetraethylene glycol ester were synthesized and compared to their ether counterparts (C(10)E(4) and C(10)E(3)). Their physicochemical properties i.e. critical micelle concentrations (CMC), cloud points, and equilibrium surface tensions were determined. Binary water-surfactant phase behavior was also studied by polarized optical microscopy. The stability of the ester bond was determined by investigating alkaline hydrolysis of the compounds. It was found that CMC, cloud point and equilibrium surface tension are roughly the same for corresponding ethers and esters. In the binary diagram, the esters form only lamellar phases, the area of which is smaller than that of the ether counterparts. These different behaviors can be related to the modification of the molecular conformation induced by the replacement of the ether group by the ester group.

Breast cancer stem cell selectivity of synthetic nanomolar-active salinomycin analogs.

PubMed

Huang, Xiaoli; Borgström, Björn; Kempengren, Sebastian; Persson, Lo; Hegardt, Cecilia; Strand, Daniel; Oredsson, Stina

2016-02-23

Cancer stem cells (CSCs) have been invoked in resistance, recurrence and metastasis of cancer. Consequently, curative cancer treatments may be contingent on CSC selective approaches. Of particular interest in this respect is the ionophore salinomycin, a natural product shown to be 100-fold more active against CSCs than clinically used paclitaxel. We have previously reported that synthetic salinomycin derivatives display increased activity against breast cancer cell lines. Herein we specifically investigate the CSC selectivity of the most active member in each class of C20-O-acylated analogs as well as a C1-methyl ester analog incapable of charge-neutral metal ion transport. JIMT-1 breast cancer cells were treated with three C20-O-acylated analogs, the C1-methyl ester of salinomycin, and salinomycin. The effects of treatment on the CSC-related CD44(+)/CD24(-) and the aldehyde dehydrogenase positive (ALDH(+)) populations were determined using flow cytometry. The survival ability of CSCs after treatment was investigated with a colony formation assay under serum free conditions. The effect of the compounds on cell migration was evaluated using wound-healing and Boyden chamber assays. The expression of vimentin, related to mesenchymal traits and expression of E-cadherin and β-catenin, related to the epithelial traits, were investigated using immunofluorescence microscopy. Treatment with each of the three C20-acylated analogs efficiently decreased the putative CSC population as reflected by reduction of the CD44(+)/CD24(-) and ALDH(+) populations already at a 50 nM concentration. In addition, colony forming efficiency and cell migration were reduced, and the expression of the epithelial markers E-cadherin and β-catenin at the cell surface were increased. In contrast, salinomycin used at the same concentration did not significantly influence the CSC population and the C1-methyl ester was inactive even at a 20 μM concentration. Synthetic structural analogs of salinomycin, previously shown to exhibit increased activity against cancer cells, also exhibited improved activity against CSCs across several assays even at nanomolar concentrations where salinomycin was found inactive. The methyl ester analog of salinomycin, incapable of charge-neutral metal ion transport, did not show activity in CSC assays, lending experimental support to ionophoric stress as the molecular initiating event for the CSC effects of salinomycin and related structures.

Elevation of Glutathione as a Therapeutic Strategy in Alzheimer Disease

PubMed Central

Pocernich, Chava B.; Butterfield, D. Allan

2011-01-01

Oxidative stress has been associated with the onset and progression of mild cognitive impairment (MCI) and Alzheimer disease (AD). AD and MCI brain and plasma display extensive oxidative stress as indexed by protein oxidation, lipid peroxidation, free radical formation, DNA oxidation, and decreased antioxidants. The most abundant endogenous antioxidant, glutathione, plays a significant role in combating oxidative stress. The ratio of oxidized to reduced glutathione is utilized as a measure of intensity of oxidative stress. Antioxidants have long been considered as an approach to slow down AD progression. In this review, we focus on the elevation on glutathione through N-acytl-cysteine (NAC) and γ-glutamylcysteine ethyl ester (GCEE) as a potential therapeutic approach for Alzheimer disease. PMID:22015471

Design, synthesis and pharmacological evaluation of (E)-3,4-dihydroxy styryl sulfonamides derivatives as multifunctional neuroprotective agents against oxidative and inflammatory injury.

PubMed

Ning, Xianling; Guo, Ying; Ma, Xiaoyan; Zhu, Renzong; Tian, Chao; Zhang, Zhili; Wang, Xiaowei; Ma, Zhizhong; Liu, Junyi

2013-09-01

A novel class of (E)-3,4-dihydroxy styryl sulfonamides and their 3,4-diacetylated derivatives as caffeic acid phenethyl ester (CAPE) analogs was designed and prepared for improving stability and solubility of the lead compound. Their neuroprotective properties were assessed by several models. The results showed that target compounds displayed positive free radical quenching abilities, superior to that of CAPE. Compounds 6j-k and 7j-k demonstrated remarkable protection effects against damage induced by hydrogen peroxide which were apparently stronger than that of CAPE. Most of target compounds could inhibit nitric oxide production. Additionally, target compounds showed high blood-brain barrier permeability. Copyright © 2013. Published by Elsevier Ltd.

Regioselective Synthesis of Cellulose Ester Homopolymers

Treesearch

Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

2012-01-01

Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

40 CFR 721.3140 - Vinyl epoxy ester.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

40 CFR 721.3140 - Vinyl epoxy ester.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

40 CFR 721.3140 - Vinyl epoxy ester.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

40 CFR 721.3140 - Vinyl epoxy ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

40 CFR 721.3140 - Vinyl epoxy ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

21 CFR 175.210 - Acrylate ester copolymer coating.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate...) The acrylate ester copolymer is a fully polymerized copolymer of ethyl acrylate, methyl methacrylate...

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Partial phosphoric acid esters of polyester resins... of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section... prescribed conditions: (a) For the purpose of this section, partial phosphoric acid esters of polyester...

40 CFR 721.10548 - Mixed alkyl phosphate esters alkoxylated (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed alkyl phosphate esters... Specific Chemical Substances § 721.10548 Mixed alkyl phosphate esters alkoxylated (generic). (a) Chemical... as mixed alkyl phosphate esters alkoxylated (PMN P-04-624) is subject to reporting under this section...

40 CFR 721.10685 - Phosphoric acid, mixed esters (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, mixed esters (generic... Specific Chemical Substances § 721.10685 Phosphoric acid, mixed esters (generic). (a) Chemical substance... phosphoric acid, mixed esters (PMN P-13-170) is subject to reporting under this section for the significant...

40 CFR 721.10548 - Mixed alkyl phosphate esters alkoxylated (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixed alkyl phosphate esters... Specific Chemical Substances § 721.10548 Mixed alkyl phosphate esters alkoxylated (generic). (a) Chemical... as mixed alkyl phosphate esters alkoxylated (PMN P-04-624) is subject to reporting under this section...

ESTIMATION OF HYDROLYSIS RATE CONSTANTS OF CARBOXYLIC ACID ESTER AND PHOSPHATE ESTER COMPOUNDS IN AQUEOUS SYSTEMS FROM MOLECULAR STRUCTURE BY SPARC

EPA Science Inventory

SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy diffe...

40 CFR 721.1579 - 1,2,4-Benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... [4-(ethenyloxy) butyl] ester. 721.1579 Section 721.1579 Protection of Environment ENVIRONMENTAL...-(ethenyloxy) butyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2,4-benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester (PMN P...

40 CFR 721.1579 - 1,2,4-Benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... [4-(ethenyloxy) butyl] ester. 721.1579 Section 721.1579 Protection of Environment ENVIRONMENTAL...-(ethenyloxy) butyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2,4-benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester (PMN P...

40 CFR 721.3085 - Brominated phthalate ester.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Brominated phthalate ester. 721.3085... Substances § 721.3085 Brominated phthalate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated phthalate ester (PMN P-90-581) is...