macromolecular synthesis operon: Topics by WorldWideScience.org

Molecular characterization of cap3A, a gene from the operon required for the synthesis of the capsule of Streptococcus pneumoniae type 3: sequencing of mutations responsible for the unencapsulated phenotype and localization of the capsular cluster on the pneumococcal chromosome.

The synthesis of an extracellular ribbon of cellulose in the bacterium Acetobacter xylinum takes place from linearly arranged, membrane-localized, cellulose-synthesizing and extrusion complexes that...Full Text Available

1994-09-01

2

narI region of the Escherichia coli nitrate reductase (nar) operon contains two genes.

The complete nucleotide sequence of the cap3A gene of Streptococcus pneumoniae, which is directly responsible for the transformation of some unencapsulated, serotype 3 mutants to the encapsulated phenotype,...Full Text Available

1994-10-01

3

Nonnative Proteins Induce Expression of the Bacillus subtilis CIRCE Regulon

In previous studies it has been established that in Escherichia coli the three known subunits of anaerobic nitrate reductase are encoded by the narGHI operon. From the nucleotide sequence of the narI...Full Text Available

1988-04-01

4

Expression of fully functional tetrameric human hemoglobin in Escherichia coli

The chaperone-encoding groESL and dnaK operons constitute the CIRCE regulon of Bacillus subtilis. Both operons are under negative control of the repressor...Full Text Available

1998-06-01

5

Role of Na+ in transport of Hg2+ and induction of the Tn21 mer operon.

Synthesis genes encoding the human #alpha#- and #beta#-globin polypeptides have been expressed from a single operon in Escherichia coli. The #alpha#- and #beta#-globin polypeptides associate into soluble tetramers, incorporate heme, and accumulate to >5% of the total cellular protein. Purified recombinant hemoglobin has the correct stoichiometry of #alpha#- and #beta#-globin chains and contains a full complement of heme. Each globin chain also contains an additional methionine as an extension to the amino terminus. The recombinant hemoglobin has a C_4 reversed-phase HPLC profile essentially identical to that of human hemoglobin A_0 and comigrates with hemoglobin A_0 on SDS/PAGE. The visible spectrum and oxygen affinity are similar to that of native human hemoglobin A_0. The authors have also expressed the #alpha#- and #beta#-globin genes separately and found that the expression of the #alpha#-globin gene alone results in a marked decrease in ...

6

Open Reading Frame all0601 from Anabaena sp. Strain PCC 7120 Represents a Novel Gene, cnaT, Required for Expression of the Nitrate Assimilation nir Operon

The effects of sodium ions on the uptake of Hg2+ and induction of the Tn21 mer operon were studied by using Escherichia coli HMS174 harboring the reporter plasmids pRB28 and pOS14. Plasmid pRB28 carries...Full Text Available

1994-10-01

7

Solid-state ¹³C NMR spectroscopy of a ¹³C carbonyl-labeled polypeptide

Expression of the nitrate assimilation nir operon in the filamentous, heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 requires the action of both the...Full Text Available

2003-09-01

8

Methylprednisolone acetate induced release of cartilage proteoglycans: determination by high performance liquid chromatography.

High resolution structural elucidation of macromolecular structure by solid-state nuclear magnetic resonance requires the preparation of uniformly aligned samples that are isotopically labeled. In...Full Text Available

1992-06-01

9

Fourier Transform Infrared Imaging and MR Microscopy Studies Detect Compositional and Structural Changes in Cartilage in a Rabbit Model of Osteoarthritis

A high performance liquid chromatography (HPLC) procedure suitable for the simultaneous determination of the molecular size and concentration of macromolecular hyaluronate and proteoglycans in synovial...Full Text Available

1992-02-01

10

Evolution of macromolecular import pathways in mitochondria, hydrogenosomes and mitosomes

Assessment of subtle changes in the primary macromolecular components of cartilage, proteoglycan (PG) and collagen, is critical for the diagnosis of early stages of osteoarthritis (OA), but...Full Text Available

2007-03-01

11

¹³C-NMR Assessment of the Pattern of Organic Matter Transformation during Domestic Wastewater Treatment by Autothermal Aerobic Digestion (ATAD)

All eukaryotes require mitochondria for survival and growth. The origin of mitochondria can be traced down to a single endosymbiotic event between two probably prokaryotic organisms. Subsequent evolution...Full Text Available

2010-03-12

12

flhDC, the Flagellar Master Operon of Xenorhabdus nematophilus: Requirement for Motility, Lipolysis, Extracellular Hemolysis, and Full Virulence in Insects

The pattern of biodegradation and the chemical changes occurring in the macromolecular fraction of domestic sludge during autothermal thermophilic aerobic digestion (ATAD) was monitored and characterised...Full Text Available

2009-08-01

13

The interplay of StyR and IHF regulates substrate-dependent induction and carbon catabolite repression of styrene catabolism genes in Pseudomonas fluorescens ST

Xenorhabdus is a major insect pathogen symbiotically associated with nematodes of the family Steinernematidae. This motile bacterium displays swarming behavior on suitable media, but...Full Text Available

2000-01-01

14

Role of the nac gene product in the nitrogen regulation of some NTR-regulated operons of Klebsiella aerogenes.

BackgroundIn Pseudomonas fluorescens ST, the promoter of the styrene catabolic operon, PstyA, is induced by styrene and is subject to catabolite...Full Text Available

15

NasFED Proteins Mediate Assimilatory Nitrate and Nitrite Transport in Klebsiella oxytoca (pneumoniae) M5al

A positive, genetic selection against the activity of the nitrogen regulatory (NTR) system was used to isolate insertion mutations affecting nitrogen regulation in Klebsiella aerogenes. Two classes...Full Text Available

1990-12-01

16

Characterization of the H(+)-pumping F1F0 ATPase of Vibrio alginolyticus.

Klebsiella oxytoca can use nitrate and nitrite as sole nitrogen sources. The enzymes required for nitrate and nitrite assimilation are encoded by the nasFEDCBA operon....Full Text Available

1998-03-01

17

Characterization of Two New Genes, amoR and amoD, in the amo Operon of the Marine Ammonia Oxidizer Nitrosococcus oceani ATCC 19707?

The F1F0 ATPase of Vibrio alginolyticus was cloned from a chromosomal lambda library. The unc operon, which contains the structural genes for the ATPase, was sequenced and shown to have a gene organization...Full Text Available

1990-12-01

18

A Response Regulator That Represses Transcription of Several Virulence Operons in the Group A Streptococcus

Molecular analysis of the amo gene cluster in Nitrosococcus oceani revealed that it consists of five genes, instead of the three known genes, amoCAB....Full Text Available

2008-01-01

19

A Coxiella burnetti repeated DNA element resembling a bacterial insertion sequence.

A search for homologs of the Bacillus subtilis PhoP response regulator in the group A streptococcus (GAS) genome revealed three good candidates. Inactivation of one of these, recently...Full Text Available

1999-06-01

20

Source tracking of Escherichia coli by 16S-23S intergenic spacer region denaturing gradient gel electrophoresis (DGGE) of the rrnB ribosomal operon.

A DNA fragment located on the 3' side of the Coxiella burnetii htpAB operon was determined by Southern blotting to exist in approximately 19 copies in the Nine Mile I genome. The DNA sequences of this...Full Text Available

1992-09-01

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Homo-d-lactic acid production from mixed sugars using xylose-assimilating operon-integrated Lactobacillus plantarum

This research validates a novel approach for source tracking based on denaturing gradient gel electrophoresis (DGGE) analysis of DNA extracted from Escherichia coli isolates. Escherichia coli from different animal sources and from river samples upstream from, at, and downstream of a combined sewer overflow were subjected to DGGE to determine sequence variations within the 16S-23S intergenic spacer region (ISR) of the rrnB ribosomal operon. The ISR was analyzed to determine if E. coli isolates from various animal sources could be differentiated from each other. DNA isolated from the E. coli animal sources was PCR amplified to isolate the rrnB operon. To prevent amplification of all 7 E. coli ribosomal operons by PCR amplification using universal primers, sequence-specific primers were utilized for the rrnB operon. Another primer set was then used to prepare samples of the 16S-23S ISR for DGGE. Comparison ...

2007-10-01

22

British Library Electronic Table of Contents (United Kingdom)

In order to achieve efficient d-lactic acid fermentation from a mixture of xylose and glucose, the xylose-assimilating xylAB operon from Lactobacillus pentosus (PXylAB) was introduced into an l-lactate dehydrogenase gene (ldhL1)-deficient Lactobacillus plantarum (?ldhL1-xpk1::tkt-?xpk2) strain in which the phosphoketolase 1 gene (xpk1) was replaced with the transketolase gene (tkt) from Lactococcus lactis, and the phosphoketolase 2 (xpk2) gene was deleted. Two copies of xylAB introduced into the genome significantly improved the xylose fermentation ability, raising it to the same level as that of ?ldhL1-xpk1::tkt-?xpk2 harboring a xylAB operon-expressing plasmid. Using the two-copy xylAB integrated strain, successful homo-d-lactic acid production was achieved from a mixture of 25?g/l xylos...

2011-01-01

23

Nucleomorph Ribosomal DNA and Telomere Dynamics in Chlorarachniophyte Algae

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT. Chlorarachniophytes are enigmatic marine unicellular algae that acquired photosynthesis by secondary endosymbiosis. Chlorarachniophytes are unusual in that the nucleus of the engulfed algal cell (a green alga) persists in a miniaturized form, termed a nucleomorph. The nucleomorph genome of the model chlorarachniophyte, Bigelowiella natans CCMP621, is 373 kilobase pairs (kbp) in size, the smallest nuclear genome characterized to date. The B. natans nucleomorph genome is composed of three chromosomes, each with canonical eukaryotic telomeres and sub telomeric ribosomal DNA (rDNA) operons transcribed away from the chromosome end. Here we present the complete rDNA operon and telomeric region from the nucleomorph genome of Lotharella oceanica CCMP622, a newly characterized chlorarachn...

2010-01-01

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The implementation of SOMO (SOlution MOdeller) in the UltraScan analytical ultracentrifugation data analysis suite: enhanced capabilities allow the reliable hydrodynamic modeling of virtually any kind of biomacromolecule

Synthesis of Perfluoroaliphatic Ether Monomers

The interpretation of solution hydrodynamic data in terms of macromolecular structural parameters is not a straightforward task. Over the years, several approaches have been developed to cope...Full Text Available

2010-02-01

25

Glycosaminoglycan synthesis by human corneal explants

... R OFFICIAL FILE COPY SYNTHESIS OF PERFLUOROALIPHATIC ETHER MONOMERS PCR, Inc. ... Synthesis of Perfluoroaliphatic Ether Monomers ...

1977-07-01

26

The hrpK Operon of Pseudomonas syringae pv. tomato DC3000 Encodes Two Proteins Secreted by the Type III (Hrp) Protein Secretion System: HopB1 and HrpK, a Putative Type III Translocator

No abstract prepared.

1998-07-01

27

Evidence for Na⁺ Influx via the NtpJ Protein of the KtrII K⁺ Uptake System in Enterococcus hirae

Pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type III protein secretion system (TTSS) and the effector proteins it translocates into plant...Full Text Available

2005-01-01

28

Synthesis of [3,3-D[sub 2

The ntpJ gene, a cistron located at the tail end of the vacuolar-type Na⁺-ATPase (ntp) operon of Enterococcus hirae, encodes a transporter...Full Text Available

2000-05-01

29

Chiral crystallization and the origin of chiral life on earth

The synthesis of [3, 3-D[sub 2

1993-01-01

30

British Library Electronic Table of Contents (United Kingdom)

Abstract The creation of chirality on Earth and the development of chiral life have been discussed in this highlight. Convincing evidence for the introduction of chirality on Earth is still fragmentary. We believe that by a combination of chiral crystallization and formation of helical polymers with preferred chiral conformational structure is the key to this question. This concept of macromolecular asymmetry has inspired ideas and resulted in possible rules for how chiral life as we know it, could have been introduced. These investigations needed the understanding of the requirements for chiral crystallization, for the stereochemistry of the initial formation of helical polymers, the measurements of optical activity of solids and their coordination with the fundamentals of chirality. Spac...

2011-01-01

31

Studies for the Synthesis of Xenicane Diterpenes. A Stereocontrolled Total Synthesis of 4-Hydroxydictyolactone

Inhibition of Ribonucleic Acid Synthesis by Nalidixic Acid in Escherichia coli

The stereocontrolled total synthesis of 4-hydroxydictyolactone (4), a member of the xenicane diterpene family of natural products, is described. These studies feature the development...Full Text Available

2009-07-01

32

Synthesis of metallic oxides particles by hydrolysis of aqueous solutions

The effect of low concentrations of nalidixic acid on ribonucleic acid (RNA) synthesis in Escherichia coli was examined. It was observed that RNA synthesis in exponentially growing...Full Text Available

1974-10-01

33

Synthesis and biological evaluation of ABCD ring fragments of the kibdelones.

Short communication.

1990-11-05

34

Synthesis and antimicrobial effects of colloidal silver nanoparticles in chitosan by?-irradiation

PMID:21370327

2011-02-18

35

Combinatorial Spray-Based Synthesis of PEM FC Electrocatalysts

Not Available

2010-04-01

36

Studies of coupled chemical and catalytic coal conversion methods

No abstract prepared.

2003-11-02

37

Diffraction applications using the energy dispersive beamline X6A at the National Synchrotron Light Source

The objective of this research was to convert coal into a soluble substance under mild conditions. The strategy involved two steps, first to breakdown the macromolecular network of coal, and second to add hydrogen catalytically. We investigated different basic reagents that could, in priciple, break down coal's structure and alkylation strategies that might enhance its solubility. We examined O- and C-alkylation, the importance of the strength of the base, the character of the added alkyl groups and other reaction parameters. This work provided new information concerning the way in which hydrogen bonding, polarization interactions between aromatic structures and covalent bonding could be disrupted and solubility enhanced. The objective of our research was to explore new organochromium chemistry that might be feasible for the hydrogenation of coal under mild conditions.

1991-12-01

38

Total Synthesis and Evaluation of C26-Hydroxyepothilone D Derivatives for Photoaffinity Labeling of ?-Tubulin

The energy dispersive beamline X6A at the National Synchrotron Light Source employs a curved crystal monochromator (polychromator) which focuses a range ([similar to]1 keV) of x-ray energies into a narrow (100--120 [mu]m) line image. Although this beamline was constructed primarily for time-dependent EXAFS experiments, we have begun to explore the use of this instrument for energy dispersive diffraction experiments with different types of sample including macromolecular crystals. The tunability ([ital E]=6.5 to 21 keV) and flexibility ([Delta][ital E]=100--1000 eV) of the instrument makes the beamline ideal as a test bed for the application of polychromatic single-crystal diffraction techniques to different chemical or biological materials.

1995-02-01

39

Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [Clln(SCH2(CO)O)2]2-[(4-MepyH)2]2+

Three photaffinity labeled derivatives of epothilone D were prepared by total synthesis, using efficient novel asymmetric synthesis methods for the preparation of two important synthetic building...Full Text Available

2010-01-01

40

Synthesis and Structural Characterization of a Novel Indium ...

The synthesis and structural characterization of a novel In(III) complex is described. The reaction

2004-01-01

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41

New approaches to the synthesis of aromatic polyesters

Robert A. Martock. Cleveland State University, Cleveland, Ohio. Synthesis and Structural Characterization of a. Novel Indium Mercapto Derivative. [Clln(SCH. 2 ...

42

British Library Electronic Table of Contents (United Kingdom)

A new method of the synthesis of high molecular polybutylene terephthalate (PBT) is developed with the use of Irganox 1010, tris(nonylphenyl) phosphite and hypophosphite as stabilizers and boron nitride or boron oxide as a catalyst is proposed.

2009-01-01

43

Development of a 2-Aza-Cope-[3+2] Dipolar Cycloaddition Strategy for the Synthesis of Quaternary Proline Scaffolds

Synthesis of substituted ["1"2"5I]iodophenyl amine derivatives: possible brain imaging agents

A one-pot multicomponent procedure for the synthesis of highly functionalized pyrrolidine rings through a domino...Full Text Available

2010-09-03

44

Synthesis of substituted (/sup 125/I)iodophenyl amine derivatives: possible brain imaging agents

Brief item.

45

Synthesis of Some 2-Amino-5-Substituted-1,3,4-Oxadiazoles Through the Electrooxidation of Semicarbazone

Brief item.

1989-01-01

46

Synthesis of Ordered Mesoporous Manganese Oxides by Double Replication for Use as an Electrode Material

Full Text Available

2009-04-01

47

Synthesis of Nano Sized Cobalt Powder from Cobalt Sulfate Heptahydrate by Liquid Phase Reduction

Full Text Available

2011-01-01

48

Synthesis and structure of the (tetrahydroxy)oligosiloxane [(tBuO)3SiOSi(OH)2]2O

Full Text Available

2011-06-01

49

Synthesis and Magnetic Properties of Zn, Co and Ni Substituted Manganese Ferrite Powders by Sol-gel Method

No abstract prepared.

2000-01-25

50

Synthesis and Magnetic Properties of Nano-sized Mn Ferrite Powder and Film

Full Text Available

2010-12-01

51

Synthesis and Characterization of New Blue Light Emitting Alternating Terphenylenevinylene Carbazylenevinylene Copolymer

Full Text Available

2011-03-01

52

Room temperature synthesis of tri-, tetrasubstituted imidazoles and bis-analogues by mercaptopropylsilica (MPS) in aqueous methanol: application to the synthesis of the drug trifenagrel

Full Text Available

2005-10-01

53

British Library Electronic Table of Contents (United Kingdom)

The heterogeneous solid catalyst, mercaptopropylsilica (MPS), has been prepared by a modified procedure in water and its structure confirmed by solid state carbon-13 CP-MAS NMR spectrum. This catalyst has been efficiently utilized for the synthesis of a wide variety of tri-, tetrasubstituted imidazoles and their bis-analogues at room temperature. The protocol was further explored for the synthesis of the drug trifenagrel.

2010-01-01

54

Electro-oxidation of Cyclohexanol on a Copper Electrode Modified by Copper-dimethylglyoxime Complex Formed by Electrochemical Synthesis

Effect of nitric oxide on endoplasmic reticulum calcium homeostasis, protein synthesis and energy metabolism

Full Text Available

2009-12-01

55

Design, synthesis and a novel application of quorum sensing agonists as potential drug-delivery vehicles

ATPase, endoplasmic reticulum, calcium, ischaemia

2000-01-01

56

Contribution to the radiation preparation of wood-plastic materials. Pt. 7

Abstract Not Provided

2009-01-01

57

Contribution to the radiation preparation of wood-plastic materials. Pt. 6

... odd nuclei organic compounds radiation effects radioisotopes synthesis

1974-01-01

58

Noise bias in the refinement of structures derived from single particles

... compounds polymers polyolefins polyvinyls radiation effects SYNTHESIS.

1974-01-01

59

Mechanism of trypsin inactivation by intact Hymenolepis diminuta (Cestoda)

One of the main goals in the determination of three-dimensional macromolecular structures from electron microscope images of individual molecules and complexes (single particles) is a sufficiently high spatial resolution, about 4 A, at which the interpretation with an atomic model becomes possible. To reach high resolution, an iterative refinement procedure using an expectation maximization algorithm is often used that leads to a more accurate alignment of the positional and orientational parameters for each particle. We show here the results of refinement algorithms that use a phase residual, a linear correlation coefficient, or a weighted correlation coefficient to align individual particles. The algorithms were applied to computer-generated data sets that contained projections from model structures, as well as noise. The algorithms show different degrees of over-fitting, especially at high resolution where the signal is weak. We demonstrate that the degree of ...

2004-12-15

60

Formation of colloidal silver nanoparticles stabilized by Na+-poly(gamma-glutamic acid)-silver nitrate complex via chemical reduction process.

The mechanism of trypsin inactivation by intact Hymenolepis diminuta has been investigated by biochemical and autoradiographic methods. Although worms inactivate trypsin and chymotrypsin in vitro, no inactivation of other endoproteases (subtilisin, pepsin and papain) could be demonstrated. Trypsin inactivation, as demonstrated by macromolecular substrates (azoalbumin, hemoglobin and casein), could not be detected using low molecular weight synthetic substrates such as N-p-benzoyl-DL-arginine-p-nitroanilide (BAPA) or N-p-tosyl-L-arginine methyl ester (TAME). In addition, the kinetic parameters (K/sub m/ and k_3) for H. diminuta-inactivated trypsin, using BAPA as the substrate, were not different from those of the native enzyme. The number of active sites for both native and inactivated trypsin were determined by titration with p-nitro-phenyl-p'-guanidinobenzoate. Absorbance values for both titrations were found to be identical. Dialysis, heating to 50 C, or repeated ...

1979-01-01

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61

An arsenic metallochaperone for an arsenic detoxification pump

Macromolecular and polyanionic Na(+)-poly(gamma-glutamic acid) (PGA) silver nitrate complex acted as both a metal ion provider and a particle protector to fabricate nanosized silver colloids under chemical reduction by dextrose. The formation and size of particles have been characterized from transmission electron microscopy (TEM), dynamic light scattering analysis and UV-vis spectrophotometer. The results showed that the average particle size was 17.2+/-3.4 to 37.3+/-5.5 nm, apparently depending on the complex concentration. It was found that the rate constant and conversion of silver nanoparticles were proportional to the concentration of PGA. The growth mechanism of nanosized silver colloid was fully discussed. In addition, the in vitro cytotoxicity evaluated by L929 fibroblasts proliferation and antibacterial activity against Gram-positive strain (methicillin-resistant S. aureus (MRSA)) and Gram-negative strain (P. aeruginosa) bacteria have been assessed. ...

2007-05-18

62

The chemical synthesis of oligoribonucleotides VII. A comparison of condensing agents in the coupling of silylated ribonucleosides.

Environmental arsenic is a world-wide health issue, making it imperative for us to understand mechanisms of metalloid uptake and detoxification. The predominant intracellular form is the highly mephitic arsenite, which is detoxified by removal from cytosol. What prevents arsenite toxicity as it diffuses through cytosol to efflux systems? Although intracellular copper is regulated by metallochaperones, no chaperones involved in conferring resistance to other metals have been identified. In this article, we report identification of an arsenic chaperone, ArsD, encoded by the arsRDABC operon of Escherichia coli. ArsD transfers trivalent metalloids to ArsA, the catalytic subunit of an As(III)/Sb(III) efflux pump. Interaction with ArsD increases the affinity of ArsA for arsenite, thus increasing its ATPase activity at lower concentrations of arsenite and enhancing the rate of arsenite extrusion. Cells are consequently resistant to environmental concentrations of arsenic. ...

2006-10-17

63

T-2 mycotoxin inhibits mitochondrial protein synthesis

The t-butyldimethylsilyl group is shown to be an ideal protecting group for the 2T-hydroxyl function of ribonucleosides during the synthesis of ribonucleotides using any of nine commonly used condensing...Full Text Available

1980-05-10

64

Synthesis and characterization of thermoresponsive polyamidoamine-polyethylene glycol-poly (D, L-lactide) (PAMAM-PEG-PDLLA) core-shell nanoparticles

The authors investigated the effect of T-2 toxin on rat liver mitochondrial protein synthesis. Isolated rat liver mitochondria were supplemented with an S-100 supernatant from rat liver and an external ATP-generating system. An in-vitro assay employing cycloheximide, and inhibitor of cytoplasmic protein synthesis, and chloramphenicol, and inhibitor of mitochondrial protein synthesis, to distinguish mitochondrial protein synthesis from the cytoplasmic process. Amino acid incorporation into mitochondria was dependent on the concentration of mitochondria and was inhibited by chloramphenicol. The rate of uptake of tritium leucine into mitochondrial protein was unaffected by the addition of T-2 toxin and was not a rate-limiting step in incorporation. However, 0.02 micrograms/ml of T-2 toxin decreased the rate of protein synthesis inhibition correlated with the amount of T-2 toxin taken ...

1988-01-01

65

Strand displacement synthesis capability of Moloney murine leukemia virus reverse transcriptase.

This work describes the synthesis and characterization of novel thermoresponsive highly-branched polyamidoamine-polyethylene glycol-poly (D, L-lactide) (PAMAM-PEG-PDLLA) core-shell nanoparticles....Full Text Available

2010-03-01

66

Simultaneous rapid chemical synthesis of over one hundred oligonucleotides on a microscale

The accepted model of retroviral reverse transcription includes a circular DNA intermediate which requires strand displacement synthesis for linearization and creation of an integration-competent, long...Full Text Available

1994-08-01

67

Research progress in the electrochemical synthesis of ferrate(VI)

An inexpensive, extremely rapid manual method for simultaneous synthesis of large numbers of oligodeoxyribonucleotides on 50 or 150 nanomole scale is described. The oligonucleotides are assembled in...Full Text Available

1984-04-01

68

Recent progress on the total synthesis of acetogenins from Annonaceae

There is renewed interest in the +6 oxidation state of iron, ferrate (VI) (FeVIO42-), because of its potential as a benign oxidant for organic synthesis, as a chemical in developing cleaner ('greener') technology for remediation processes, and as an alternative for environment-friendly battery cathodes. This interest has led many researchers to focus their attention on the synthesis of ferrate(VI). Of the three synthesis methods, electrochemical, wet chemical and thermal, electrochemical synthesis has received the most attention due to its ease and the high purity of the product. Moreover, electrochemical processes use an electron as a so-called clean chemical, thus avoiding the use of any harmful chemicals to oxidize iron to the +6 oxidation state. This paper reviews the development of electrochemical methods to synthesize ferrate(VI). The approaches chosen by different laboratories to overcome some of ...

2009-04-01

69

ROMP from ROMP: A New Approach to Graft Copolymer Synthesis

SummaryAn overview of recent progress on the total synthesis of acetogenins from Annonaceae during the past 12 years is provided. These include mono-tetrahydrofurans, adjacent bis-tetrahydrofurans,...Full Text Available

70

Prevention of guanine modification and chain cleavage during the solid phase synthesis of oligonucleotides using phosphoramidite derivatives.

A new strategy is presented for the synthesis of graft copolymers using only the ring-opening metathesis polymerization (ROMP). From a ROMP-derived main chain, pendant maleimide functional groups...Full Text Available

2009-06-23

71

Phytochelatin Synthesis and Glutathione Levels in Response to Heavy Metals in Tomato Cells ¹

Phosphoramidite reagents can phosphitylate guanine bases at the O6-position during solid phase synthesis and serious chain cleavage occurs if the base phosphitylation is not eliminated before the iodine/water...Full Text Available

1986-08-26

72

Malate- and Pyruvate-Dependent Fatty Acid Synthesis in Leucoplasts from Developing Castor Endosperm 1

Cell suspension cultures of tomato, Lycopersicon esculentum Mill. cv VFNT-Cherry, produce phytochelatins (poly[γ-glutamylcysteinyl]glycines) when exposed to cadmium. The synthesis...Full Text Available

1987-12-01

73

Leucoplasts were isolated from the endosperm of developing castor (Ricinis communis) endosperm using a discontinuous Percoll gradient. The rate of fatty acid synthesis was highest...Full Text Available

1992-04-01

74

Indirect liquefaction

Effect of hypophysectomy on liver nuclear ribonucleic acid synthesis in aging rats.

Research programs, presented at the contractor's review meeting on indirect liquefaction, are presented on the following topics: oxygenates (methanol) synthesis; Fischer-Tropsch synthesis; product upgrading; and process support engineering evaluations. A total of 18 reports are included. Individual projects are processed separately for the data bases. (CBS)

1989-01-01

75

Determination of Adenosine Triphosphate on Marine Particulates:Synthesis of Methods for Use on OTEC Samples

Changes in RNA synthesis in liver nuclei were observed at different ages and after hypophysectomy and hormone replacement in female Sprague-Dawley rats. As determined by the incorporation of [3H]UMP...Full Text Available

1979-12-15

76

Characterization of Thermoanaerobacter Glucose Isomerase in Relation to Saccharidase Synthesis and Development of Single-Step Processes for Sweetener Production

Adenosine triphosphate (ATP) is an indicator of living biomass in marine particulates. This report details the method used by Lawrence Berkeley Laboratory to analyze particulate ATP in samples taken from oligotrophic, tropical ocean waters. It represents a synthesis of previously published methods.

1982-08-01

77

Attachment Stimulates Exopolysaccharide Synthesis by a Bacterium

Regulation of glucose isomerase synthesis was studied in Thermoanaerobacter strain B6A, which fermented a wide variety of carbohydrates including glucose, xylose, lactose, starch, and...Full Text Available

1990-09-01

78

Application of the Chloro Ketal Claisen Reaction to the Total Synthesis of Squalene^*

This study examined the hypothesis that solid surfaces may stimulate attached bacteria to produce exopolymers. Addition of sand to shake-flask cultures seemed to induce exopolymer synthesis by a number...Full Text Available

1993-10-01

79

ANTITUMOR ACTIVITY OF HYALURONIC ACID SYNTHESIS INHIBITOR 4-METHYLUMBELLIFERONE IN PROSTATE CANCER CELLS

A short, highly stereoselective (over 97%) synthesis of all-trans squalene is described. Starting with succinaldehyde, a tetraenedichlorodione having the complete squalene skeleton...Full Text Available

1970-11-01

80

ADP-Glucose Pyrophosphorylase, a Regulatory Enzyme for Bacterial Glycogen Synthesis

4-methylumbelliferone (4-MU) is a hyaluronic acid (HA) synthesis inhibitor with anticancer properties; the mechanism of its anticancer effects is unknown. We evaluated the effects of 4-MU on...Full Text Available

2010-04-01

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81

Synthesis, Chemical Characterization and Catalytic Activity of Transition Metal Complexes Having Imine Based Nitrogen Donor Ligand

The accumulation of α-1,4-polyglucans is an important strategy to cope with transient starvation conditions in the environment. In bacteria and plants, the synthesis of glycogen and starch occurs...Full Text Available

2003-06-01

82

Synthesis of model compounds for coal liquification research

Full Text Available

2010-02-01

83

Synthesis of esters from lupeol isolated from Maytenus salicifolia (Celastraceae)

Research continued on the synthesis of model compounds for coal liquefaction research. This report covers the actual laboratory investigation performed during the reporting period in order to attain the stated objective of the project, viz, the synthesis of a model compound containing tetrahydronaphthalene, naphthalene and phenyl moieties linked by methylene, ethylene and ether bonds. The overall synthetic approach aimed at obtaining the end product has been broken down into three major steps that involve the synthesis of three key reactive intermediates. These are: (1) 3,5-dimethyl-5-bromobenzyl chloride, (2) 1-chloromethylene-2-hydroxytetralin and (3) 2-chloromethylene-1-hydroxynaphthalene.

1990-10-08

84

Synthesis of Some New 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone Derivatives

Portuguese 2009 1 p. Brazil Magalhaes, Cassia Goncalves Silva, Gracia

85

Self-Propagating High-Temperature Synthesis Technologies

Full Text Available

2011-04-01

86

International Science & Technology Center (ISTC)

Development of SHS-technologies for SiC, Si3N4 and Ceramic Composites on Their Basis from Rocks

87

Possible processes of abiogenic synthesis of biologically important compounds on surface of small bodies in the Solar System

Los Alamos National Laboratory's Hydrogeologic Studies of the Pajarito Plateau: A Synthesis of Hydrogeologic Workplan Activities (1998--2004)

A mixture of aminoacids was irradiated by a scattered proton beam, its energy varying from 4 to 6.6 MeV, by doses up to 5 x 10"1"1 proton/cm"2 for studying the potentiality of abiogenic synthesis of biologically important compounds in space. It was ascertained that increase in the radiation dose and reduction of proton energy involve increase in effectiveness both of destruction of the initial aminoacid (tryptophan, tyrosine, glycine) and synthesis of the relevant dipeptide. Essential influence of mineral substrate on abiogenic synthesis of natural nucleotides under the action of diverse energy sources was pointed out

2004-04-01

88

Effects of optisol-GS incubation on the profile of corneal synthesis and secretion- partial characterization of the secreted p{sub 25} fraction

No abstract prepared.

2005-12-13

89

Cyanide-bridged Trinuclear and Ethylenediamine-bridged One-dimensional Cobalt(III)-Manganese(II) Complexes: Synthesis, Crystal Structures and Magnetic Properties

No abstract prepared.

2007-07-01

90

Total synthesis of cis-solamin A, a mono-tetrahydrofuran acetogenin isolated from Annona muricata

Full Text Available

91

British Library Electronic Table of Contents (United Kingdom)

Total synthesis of cis-solamin A was accomplished without using protecting groups starting from (-)-muricatacin in 11 steps with an overall yield of 4.5%. The backbone of cis-solamin A was constructed by olefin cross-metathesis between the tetrahydrofuran moiety and g-lactone moiety. An enzymatic kinetic transesterification procedure was successfully applied to the synthesis of an optically pure g-lactone moiety.

2008-01-01

92

Robotics for the production of several short-lived positron-emitting radiopharmaceuticals

Regulation of expression of a soybean storage protein subunit gene. Progress report

We have recently shown the applicability of robotics to the synthesis of a positron-emitting radiopharmaceutical, namely 16#alpha#[F-18]fluoroestradiol-17#beta#, a breast tumor imaging agent. We now report the application of the robot to the synthesis of two additional radiopharmaceuticals, [F-18]spiroperiodol and [C-11]butanol. This achievement shows the power of a robot as a multifunctional automated device for the synthesis of several positron-emitting radiopharmaceuticals in limited laboratory space. (author).

93

Process for producing dimethyl ether form synthesis gas

We have found that the methionine repression of the ..beta..-subunit gene expression is not due to degradation of the ..beta..-subunit but is due to an effect on synthesis of the ..beta..-subunit. The effect of methionine on the synthesis of the ..beta..-is due to an inhibition of ..beta..-subunit mRNA synthesis. 3 references, 1 figure.

1984-04-23

94

A Facile One-Pot Expeditious Synthesis of Thiazolyl-pyrazolones

This invention pertains to a Fischer Tropsch process for converting synthesis gas to an oxygenated hydrocarbon with particular emphasis on dimethyl ether. Synthesis gas comprising carbon monoxide and hydrogen are converted to dimethyl ether by carrying out the reaction in the presence of an alkali metal-manganese-iron carbonyl cluster incorporated onto a zirconia-alumina support.

1985-01-01

95

British Library Electronic Table of Contents (United Kingdom)

A novel, one-pot, multicomponent synthesis of 4-arylidene-3-methyl-1-(4-arylthiazol-2-yl)-1H-pyrazol-5(4H)-ones is described using phenacyl bromides, thiosemicarbazide, ethylacetoacetate, and aryl aldehydes. This synthesis involves simultaneous formation of two heterocycles like thiazole and pyrazolone along with condensation of active methylene group by aldehydes via Knoevenagel reaction. The methodology is mild, efficient, and high yielding. GRAPHICAL ABSTRACT[image omitted

2011-01-01

96

Solid state electrochemistry and spectroelectrochemistry of poly(arylene bisimide-alt-oligoether)s

Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction

Two electroactive polymeric arylene bisimides, namely poly[(4,7,10-trioxatrideca-1,13-diyl)-(1,4,5,8-naphthalenetetracarboxylic bisimide-N,N'-diyl)] and its perylene analogue - poly[(4,7,10-trioxatrideca-1,13-diyl)-(3,4,9,10-perylenetetracarboxylic bisimide-N,N'-diyl)] have been synthesized and studied by cyclic voltammetry, UV-vis-NIR as well as Raman spectroeletrochemistry. Contrary to low molecular weight arylene bisimides, which show a clear two electron, double-step electrochemical reduction (neutral form to radical anion and from radical anion to dianion), in the synthesized polymers multielectron transfers are observed, accompanied with a strong electrochromic effect. However, as probed by cyclic voltammetry, their first reduction step is retarded and covers a wider potential range. We attribute this effect to macromolecular nature of the compounds being reduced and their structural inhomogeneity caused by ?-stacking induced nanoaggregation of bisimide ...

2011-04-01

97

Effect of vitamin D on the intestinal absorption of 203Pb and 47Ca in chicks

Low-temperature catalytic pretreatment is a promising approach to the development of an improved liquefaction process- This work is a fundamental study on effects of pretreatments on coal structure and reactivity in liquefaction. The main objectives of this project are to study the coal structural changes induced by low-temperature catalytic and thermal pretreatments by using spectroscopic techniques; and to clarify the pretreatment-induced changes in reactivity or convertibility of coals in the subsequent liquefaction. This report describes the recent progress of our work. Substantial progress has been made in the spectroscopic characterization of structure and pretreatment-liquefaction reactions of a Montana subbituminous Coal (DECS-9), and thermochemical analysis of three mw and reacted bituminous coals. Temperature programmed liquefaction has been performed on three low-rank coals both in the presence and absence of dispersed molybdenum sulfide catalyst. We also performed a ...

1992-08-01

98

Effect of vitamin D on the intestinal absorption of /sup 203/Pb and /sup 47/Ca in chicks

The transfer of 203Pb and/or 47Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). 203Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of 203Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of 203Pb by intestinal tissue but did accelerate 203Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased 47Ca tissue levels and increased 47Ca absorption. In rachitic chicks, the rate of absorption of 203Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in al segments was similar, indicting the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum greater than ileum. An acute dose of 1,25(OH)2D3 to rachitic chicks also enhanced both ...

1982-03-01

99

Copper removal by algal biomass: Biosorbents characterization and equilibrium modelling

The transfer of /sup 203/Pb and/or /sup 47/Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). /sup 203/Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of /sup 203/ Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of /sup 203/Pb by intestinal tissue but did accelerate /sup 203/Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased /sup 47/Ca tissue levels and increased /sup 47/Ca absorption. In rachitic chicks, the rate of absorption of /sup 203/Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in all segments was similar, indicating the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum > ileum. An acute dose of ...

1982-03-01

100

Analysis of organic sulfur and nitrogen in coal via tandem degradation methods. Technical report, 1 December 1992--28 February 1993

The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g{sup -1}) and proton binding parameters (pK{sup '}{sub H}=5.0,5.3and4.4;m{sub H} = 0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A non-ideal, semi-empirical, thermodynamically consistent (NICCA) isotherm fitted better ...

2009-04-30

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101

Synthesis of CdSe nanoparticles and their effect on the antioxidant activity of Spirulina platensis and Porphyridium cruentum cells

N/C and S/C ratios show only minor differences between asphaltenes and coal on this basis, the asphaltenes continue to appear to be good surrogates for the characterization of organic acid rain precursors in coal. Alkylmethoxythiophene carboxylic acids (ATCA) are detected in all dichromate oxidation products analyzed to date. Relative concentrations of ATCA compounds are directly proportional to the sample`s bulk organic sulfur contents. Concentrations of ATCA compounds in oxidation products decrease upon repeated oxidation. This may indicate that the thiophenic groups tend to be located in external positions on the coal macromolecular structure and a high proportion of them can be stripped away with only one mild oxidation step. If true, this may make industrial-scale removal of organic sulfur easier than expected. Using analytical micropyrolysis-gas chromatography with a sulfur-selective flame photometric detector, it is possible to easily see a full distribution ...

1993-05-01

102

Performance of trickle-bed bioreactors for converting synthesis gas to methane

Single-crystalline cadmium selenide nanoparticles were obtained using high-temperature solution phase synthesis (HTSPS) synthesis. X-Ray powder diffraction and transmission electron microscopy were used to confirm the crystallinity and morphology of the resulting nanoparticles. To study the action of CdSe on antioxidant activity, we selected two biotechnological important strains of microalgae: cyanobacteria Spirulina platensis and red microalgae Porphyridium cruentum. In the case of Porphyridium cruentum, the obtained results demonstrated an increase in the productivity. For Spirulina platensis, the presence of the compound in the cultivating medium decreased the productivity of cyanobacteria.

2011-07-07

103

Total synthesis of solanoeclepin A

Carbon monoxide, H{sub 2}, and CO{sub 2} in synthesis gas can be converted to CH{sub 4} by employing a triculture of Rhodospirillum rubrum, Methanosarcina barkeri, and Methanobacterium formicicum. Trickle-bed reactors have been found to be effective for this conversion because of their high mass-transfer coefficients. This paper compares results obtained for the conversion of synthesis gas to CH{sub 4} in 5-cm- and 16.5-cm-diameter trickle-bed reactors. Mass-transfer and scale-up parameters are defined, and light requirements for R. rubrum are considered in bioreactor design.

1991-12-31

104

British Library Electronic Table of Contents (United Kingdom)

Cyst nematodes are troublesome parasites that live on, and destroy, a range of important host vegetable plants. Damage caused by the potato cyst nematode has now been reported in over 50 countries. One approach to eliminating the problem is to stimulate early hatching of the nematodes, but key hatching stimuli are not naturally available in sufficient quantities to do so. Here, we report the first chemical synthesis of solanoeclepin A, the key hatch-stimulating substance for potato cyst nematode. The crucial steps in our synthesis are an intramolecular cyclization reaction for construction of the highly strained tricyclo[5.2.1.01,6]decane skeleton (DEF ring system) and an intramolecular Diels???Alder reaction of a furan derivative for the synthesis of the ABC carbon framework. The present ...

2011-01-01

105

Synthesis, Characterization and Chondroprotective Properties of a Hyaluronan Thioethyl Ether Derivative

Synthesis of iodine-125 labelled aryl and vinyl iodides

Hyaluronan (HA), a non-sulfated glycosaminoglycan, is widely used in the clinic for viscosurgery, viscosupplementation, and treatment of osteoarthritis. Four decades of chemical modification...Full Text Available

2008-04-01

106

Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Using HClO4-SiO2 as a Heterogeneous and Recyclable Catalyst

Iodine-125 labelled vinyl and aryl iodides are formed via the reaction of sodium iodide-125 with vinyl- and arylboronic acids. Good yields of isomerically pure products are obtained.

1982-06-01

107

Synthesis and characterization of platinum(II) complexes containing tetracycline derivatives like ligands; Sintese e caracterizacao de complexos de platina(II) contendo derivados de tetraciclina como ligantes

Full Text Available

2008-09-01

108

Synthesis and characterization of a oxovanadium(IV) tetracycline binuclear complex; Sintese e caracterizacao de um complexo binuclear de oxovanadio(IV) da tetraciclina

No abstract prepared.

2005-07-01

109

Synthesis and biodistribution of ["1"2"3I]-4-Iodo-N-(2-morpholino-ethyl)benzamide - one molecule in a class of potential brain imaging agents

No abstract prepared

1996-12-31

110

Standard of mineralocorticoid secretion in the Cushing Syndrome: evidences of inhibition of the aldosterone path synthesis in the glomerulus zone

Short communication.

111

Simultaneous Consolidation of Titanium Diboride with Self-Propagating High-Temperature Synthesis, Direct Contact-Heating, and Pressure: Modeling of Temperature Distribution and the Relationship between Applied Energy and Densification

Portuguese 1984. p. 146. Brazil Czepielewski, MA Kater, CE Biglieri, EG Escola

1984-10-27

112

Science and Technology Centers

Full Text Available

1995-07-01

113

Molecules | Special Issue: Neuroactive Compounds

... MPS) Advanced Liquid Crystalline Optical Materials Superconductivity Computation and Visualization ... Cement-Based Materials Synthesis, Growth, and Analysis of Electronic Materials Photoinduced Charge ...

114

NAME=\\

Wastenet

...Synthesis of low-temperature, fast, single-firing body for porcelain stoneware tiles with coal gangue Synthesis of low-temperature, fast, single-firing body for porcelain stoneware ... tiles with coal gangue Synthesis of low-temperature, fast, single-firing body for porcelain stoneware tiles with coal gangue Wei et al.,... Article Synthesis of low-temperature, fast, single-firing body for porcelain stoneware tiles with coal gangue Qiangwei Wei1, Wenyuan Gao1*, and Xinguo ...According to phase diagram theory, a low-temperature, fast, single-firing body mix for porcelain stoneware tiles was designed in the quaternary system CaO-MgO-Al2O3-SiO2, using ...

115

Wastenet

... Here we will summarize the synthesis, structure activity relationships , and molecular sites of action of mGluR5 PAMs. We will also review preclinical studies ...

116

Modeling protein synthesis from a physicist's perspective: a toy model

Metastability of yttrium-oxides.

Proteins are polymers of amino acids. These macromolecules are synthesized by intracellular machines called {\\it ribosome}. Although, traditionally, the experimental investigation of protein synthesis has been an active area of research in molecular cell biology, important quantitative models of this phenomenon have been reported mostly in the research journals devoted to statistical physics and related interdisciplinary topics. From the perspective of a physicist, protein synthesis is a phenomenon of {\\it classical transport of interacting ribosomes on a messenger RNA (mRNA) template} that dictates the sequence of the amino acids on the protein. Here we bring this frontier area of contemporary research into the classroom by appropriate simplification of the models and methods. In particular, we develope a simple toy model and analyze it by some elementary techniques of non-equilibrium statistical mechanics to predict the average rate of ...

2007-01-01

117

Induction and Repression of Nitrate Reductase in Neurospora crassa

Metastable yttrium-oxide films are synthesized using reactive sputter deposition. The yttrium concentration of the as-deposited film is found to vary as a function of the sputter deposition rate. In addition to the synthesis of the cubic equilibrium phase...

1993-01-01

118

General Disclaimer One or more of the Following Statements may ...

Synthesis of wild-type Neurospora crassa assimilatory nitrate reductase is induced in the presence of nitrate ions and repressed in the presence of ammonium ions. Effects of several...Full Text Available

1978-02-01

119

Extracellular Synthesis of Infectious Ribonucleoprotein on ...

Hie synthesis of diverse biologically important compounds, under condi- tions which existed on the earth in the initial period of its evolution, ha; ...

120

Epidemiologic Evidence on the Health Effects of Perfluorooctanoic Acid (PFOA)

... 0.2 ml each were taken. The reaction was stopped by the addition of 1 ml LO% trichloracetic acid (TCA) in 0.1 mole of pyrophosphate ...

2011-05-13

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

121

DNA synthesis inhibition in mammalian cells as a test for mutagenic carcinogens

Objective and sourcesWe reviewed the epidemiologic literature for PFOA.Data synthesisPerfluorooctanoic acid (PFOA) does not occur naturally but is...Full Text Available

2010-08-01

122

Centers of Research Excellence in Science and Technology

Current models of DNA repair of biological damage are reviewed correlating the similarity between carcinogenesis and mutagenesis theories. (PCS)

1979-01-01

123

COAST and MRO to Join Forces

... 4? Program History 5? Center for Advanced Materials and Smart Structures 6? Center for Systems ... Systems 14? Center for Photonic Materials Research 15? Synthesis, Manufacturing and Characterization ...

124

A practical microreactor for electrochemistry in flow

Cambridge scientists in the late 1980's. This same team, then headed by Professor John Baldwin, built the world's first separated-element optical/infrared aperture synthesis...

2011-09-15

125

Unraveling photosystems. Final technical report

SummaryA microreactor for electrochemical synthesis has been designed and fabricated. It has been shown that different reactions can be carried out successfully using simple protocols.

126

l-Proline-catalyzed one-pot expeditious synthesis of highly substituted pyridines at room temperature

This report highlights four main points. (1) A residue substitution in phosphoribulokinase of Synechocystis PCC 6803 renders the mutant light-sensitive. The authors isolated a light-sensitive mutant (BRLS) of the photosynthetic cyanobacterium Synechocystis 6803 that does not survive exposure to bright light; 70% of BRLS cells die upon exposure to light of > 3000 lux for 2 hr. (2) Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. A greenish mutant of the normally bule-green cyanobacterium Synechocystis sp. PC 6803, designated UV6p, was isolated and characterized. UV6p possesses functional photosystems I and II but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. (3) Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp. PCC 6803 leads to the activation of the cryptic psbG2 gene. The genes psbG1 and psbG2 in ...

1997-09-01

127

British Library Electronic Table of Contents (United Kingdom)

Only 15mol% of l-proline in ethanol proved to be a very efficient catalyst for the one-pot synthesis of a wide variety of highly substituted pyridines at room temperature. The methodology is mild, efficient, high yielding, and the products can be directly recrystallized from hot ethanol.

2010-01-01

128

Variable Frequency Microwave Synthesis of Silver Nanoparticles

Utilization of plastic wastes in a blast furnace - a contribution to ecological and economical recycling of plastic wastes; Kunststoffverwertung im Hochofen - ein Beitrag zum oekologischen und oekonomischen Recycling von Altkunststoffen

Synthesis of silver nanoparticles based on a polyol process and variable frequency microwave (VFM) was investigated. Comparing to a thermal method, the reaction by VFM radiation was much faster. The effects of silver nitrate concentration, poly(N-vinylpyrrolidone) (PVP) concentration, reaction time and reaction temperature were studied. It was found that the higher concentration of silver nitrate, longer reaction time and higher temperature increased the particle size while the higher concentration of PVP decreased the particle size.

2006-02-15

129

Using decoupled characteristic in the synthesis of stabilizers in multimachine systems

This article describes the utilization of plastic wastes in a blast furnace. The plastic waste is a substitution for petroleum and coal as a raw material for synthesis gas production. The synthesis gas is the reducing agent in the blast furnace for the reduction of iron ores. You can find here an ecological and economical analysis of this process in comparison to the utilization of petroleum and coal. (SR)

1996-12-31

130

Synthesis, properties and biologic activity of nitro-benzo (B) of thiophene- and 2,3-di-hydro-benzo (B) thiophene-1,1-dioxides

A decoupled characteristic between the damping of a specific swing mode and the stabilizer gain of the corresponding machine in multimachine power systems is identified. Using this decoupled characteristic a power system stabilizer (PSS) synthesis approach which is based on the phase compensation concept is verified on a 9-machine system and the dynamic performance of this system is significantly improved. This method is proved to be effective, simple and it can provide useful guidance for the PSS field tuning.

1987-02-01

131

Synthesis of non-steroidal anti-inflammatory drug analogues for selective studies on the COX-II enzyme

The purpose of work is systematical studying of benzo (B) of thiophene-1,1-dioxides and their 2,3-di-hydro derivatives behaviour in the reactions of electrophflic, radical, nucleophilic nitration, reduction of nitro group, embodiment of synthesis of N-amino derivatives, investigation of sulfur containing hetero-cyclic compounds, including of residues of some steroids

1998-01-01

132

Synthesis of b-functionalized Temoporfin derivatives for an application in photodynamic therapy

Synthesis of the azido substituted non-steroidal anti-inflammatory drug 2-(2,6-dichloroanilino)phenylacetic acid and isotope labeling of this compound have been performed and are described. Initial evaluation of the binding ability and photoreactivity indicates that this compound has potential for photoaffinity labeling as well as enzyme selectivity studies. (author).

133

British Library Electronic Table of Contents (United Kingdom)

The synthesis of novel b-functionalized derivatives of the clinically used photosensitizer Temoporfin has been achieved by nucleophilic addition reactions to a corresponding diketo chlorin. The b-substituted dihydroxychlorin products exhibit a strong absorption in the red spectral region, a high singlet oxygen quantum yield, and were found to be highly effective in in vitro assays against HT-29 tumor cells.

2011-01-01

134

Synthesis of /sup 14/C-labeled 10,11-epoxyfarnesyl diazoacetate, a potential photoaffinity labeling reagent for insect juvenile hormone binding proteins

Synthesis and cloning of the genes of antisense peptides of human calcitonin and miniproinsulin

The synthesis of (/sup 14/C)-10,11-Epoxy-(2E,6E)-farnesyl diazoacetate in one vessel, starting from (/sup 14/C)-glyoxylic acid, is described. This compound is useful as a potential photoaffinity labeling agent for juvenile hormone binding sites.

1982-04-01

135

Suppression of glycosaminoglycan synthesis by articular cartilage, but not of hyaluronic acid synthesis by synovium, after exposure to radiation

With the aim of an experimental check on the validity of the theory of molecular recognition, the authors have carried out the chemical-enzymatic synthesis and cloning of the gene of human calcitonin and also of the genes of antisense polypeptides to human calcitonin and miniproinsulin. It has been shown that recombinant plasmids obtained on the basis of these synthetic genes are capable of ensuring the biosynthesis of the given polypeptides in E. coli cells as hybrid proteins with the IgG-binding domain of staphylococcal protein A.

1994-07-20

136

Strange matter and Big Bang helium synthesis

We recently found that injection of 2 mCi of yttrium 90 (90Y; approximately 23,000 rads) into normal canine knees stimulated glycosaminoglycan (GAG) synthesis by femoral condylar cartilage. The present investigation was conducted to determine whether radiation affects cartilage metabolism directly. Rates of GAG synthesis and degradation in normal canine articular cartilage were studied following irradiation. Cultured synovium from the same knees was treated similarly, to determine the effects of irradiation on hyaluronic acid synthesis. Twenty-four hours after exposure to 1,000 rads, 10,000 rads, or 50,000 rads, 35S-GAG synthesis by the cartilage was 93%, 69%, and 37%, respectively, of that in control, nonirradiated cartilage. The effect was not rapidly reversible: 120 hours after exposure to 50,000 rads, GAG synthesis remained at only 28% of the control level. Autoradiography ...

1989-01-01

137

Strange matter and Big Bang helium synthesis

Stable strange quark matter produced in the QCD phase transition in the early universe will trap neutrons and repel protons, thus reducing primordial helium production, Ysub(p). For reasonable values of Ysub(p), the radius of strange droplets must exceed 10/sup -6/ cm if strange matter shall solve the dark-matter problem without spoiling Big Bang helium synthesis. (orig.).

1985-08-15

138

Statistical mapping analysis of serotonin synthesis images generated in healthy volunteers using positron-emission tomography and alpha-[11C]methyl-L-tryptophan.

Stable strange quark matter produced in the QCD phase transition in the early universe will trap neutrons and repel protons, thus reducing primordial helium production, Ysub(p). For reasonable values of Ysub(p), the radius of strange droplets must exceed 10/sup 6/ cm if strange matter shall solve the dark-matter problem without spoiling Big Bang helium synthesis. (orig.).

1985-08-15

139

Signal transduction pathway controlling synthesis of a class of degradative enzymes in Bacillus subtilis: expression of the regulatory genes and analysis of mutations in degS and degU.

OBJECTIVES: To assess the suitability of analyzing functional images of brain serotonin (5-HT) synthesis with statistical parametric mapping (SPM), and to investigate further possible sex-related regional...Full Text Available

2000-09-01

140

ONR-NRL Superconducting Materials Symposium: A forecast

The rates of synthesis of a class of both secreted and intracellular degradative enzymes in Bacillus subtilis are controlled by a signal transduction pathway defined by at least four regulatory genes:...Full Text Available

1990-02-01

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141

Equine infectious anemia virus and human immunodeficiency virus DNA synthesis in vitro: characterization of the endogenous reverse transcriptase reaction.

Partial Contents: Ternary Compounds; Granular Superconductors; Superconductivity in (SN)x and its Halogen Derivative (SNBr0.4)x; Studies of cuCl at Elevated Pressures; Superconducting Properties of Hydride Systems; Thin Film Superconducting Materials Research; Synthesis of Superconducting Nb3Si using High Pressures; Synthesis of Unstable A-15 Compounds by Epitaxial Recrystallization of Ion Implanted Layers; and Sputtering of Nb3Si.

1979-01-01

142

Enzymic Synthesis of Indole-3-Acetyl-1-O-?-d-Glucose ¹

The endogenous reverse transcriptase reaction of equine infectious anemia virus (EIAV) has been studied, and conditions allowing synthesis of full-length minus-strand DNA have been determined. In contrast...Full Text Available

1991-04-01

143

Characterization and engineering of sequences controlling in vivo synthesis of brome mosaic virus subgenomic RNA.

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-β-d-glucose...Full Text Available

1988-12-01

144

Changes in the extracellular matrix and glycosaminoglycan synthesis during the initiation of regeneration in adult newt forelimbs

Expression of brome mosaic virus (BMV) coat protein and internal genes of many other positive-strand RNA viruses requires initiation of subgenomic mRNA synthesis from specific internal sites on minus-strand...Full Text Available

1988-07-01

145

Regulation of human ribosomal RNA transcription.

The extracellular matrix (ECM) of the distal tissues in a newt limb stump is completely reorganized in the 2-3-week period following amputation. In view of numerous in vitro studies showing that extracellular material influences cellular migration and proliferation, it is likely that the changes in the limb's ECM are important activities in the process leading to regeneration of such limbs. Using biochemical, autoradiographic, and histochemical techniques we studied temporal and spatial differences in the synthesis of glycosaminoglycans (GAGs) during the early, nerve-dependent phase of limb regeneration. Hyaluronic acid synthesis began with the onset of tissue dedifferentiation, became maximal within 1 weeks, and continued throughout the period of active cell proliferation. Chondroitin sulfate synthesis began somewhat later, increased steadily, and reached very high levels during chondrogenesis. During the first 10 days ...

1986-01-01

146

Crystal structure of Spot 14, a modulator of fatty acid synthesis

We have used a cell-free polymerase I transcription system derived from HeLa cells to study the regulation of human rRNA synthesis. Analysis of deletion mutants spanning the start site of transcription at nucleotide +1 indicates that the control region affecting initiation of human rRNA synthesis is contained within sequences from nucleotides -158 to +18. This promoter region can be subdivided into (i) a central segment of approximately 40 base pair that is required for transcription and (ii) flanking sequences that influence the efficiency of transcription in vitro. We have examined the in vitro transcriptional activity of the human extract under various conditions that are thought to modulate rRNA synthesis in vivo. Cell-free extracts prepared from HeLa cells infected with adenovirus 2 synthesize human rRNA at levels greatly decreased relative to uninfected cell extracts. By contrast, in vitro transcription of human rRNA ...

1983-06-01

147

The Burden and Determinants of Neck Pain in the General Population

Spot 14 (S14) is a protein that is abundantly expressed in lipogenic tissues and is regulated in a manner similar to other enzymes involved in fatty acid synthesis. Deletion of S14 in mice decreased lipid synthesis in lactating mammary tissue, but the mechanism of S14's action is unknown. Here we present the crystal structure of S14 to 2.65 {angstrom} and biochemical data showing that S14 can form heterodimers with MIG12. MIG12 modulates fatty acid synthesis by inducing the polymerization and activity of acetyl-CoA carboxylase, the first committed enzymatic reaction in the fatty acid synthesis pathway. Coexpression of S14 and MIG12 leads to heterodimers and reduced acetyl-CoA carboxylase polymerization and activity. The structure of S14 suggests a mechanism whereby heterodimer formation with MIG12 attenuates the ability of MIG12 to activate ACC.

2011-09-06

148

British Library Electronic Table of Contents (United Kingdom)

Study Design Best evidence synthesis. Objective To undertake a best evidence synthesis of the published evidence on the burden and determinants of neck pain and its associated disorders in the general population. Summary of Background Data The evidence on burden and determinants of neck has not previously been summarized. Methods The Bone and Joint Decade 2000?2010 Task Force on Neck Pain and Its Associated Disorders performed a systematic search and critical review of literature published between 1980 and 2006 to assemble the best evidence on neck pain. Studies meeting criteria for scientific validity were included in a best evidence synthesis. Results We identified 469 studies on burden and determinants of neck pain, and judged 249 to be scientifically admissible; 101 articles related to...

2008-01-01

149

Synthesis and antimicrobial activity of (E) stilbene derivatives

British Library Electronic Table of Contents (United Kingdom)

Plants use multiple defence mechanisms comprising both constitutive and inducible barriers to prevent entering of phytopathogenic micro-organisms. In many plant species one of the most efficient responses to combat attacking microbes is the rapid synthesis of antimicrobial low molecular weight phytoalexins, for example, resveratrol, 3,5,4prime-trihydroxystilbene (1). Resveratrol and its natural derivatives, however, display only moderate antimicrobial effects. Nevertheless, resveratrol may be a useful lead structure for the chemical synthesis of antimicrobials. In this study, several series of stilbenes have been synthesized, starting from the aldehydes using Wittig reactions to access the corresponding styrenes that were subjected to Mizoroki-Heck reactions to yield the stilbenes in good ...

2011-01-01

150

Stoichio-kinetic modeling and optimization of chemical synthesis: Application to the aldolic condensation of furfural on acetone

British Library Electronic Table of Contents (United Kingdom)

The condensation reaction of furfural (F) on acetone (Ac) gives a high added value product, the 4-(2-furyl)-3-buten-2-one (FAc), used as aroma in alcohol free drinks, ice, candies, gelatines and other products of current life. This synthesis valorises the residues of sugar cane treatment since furfural is obtained by hydrolysis of sugar cane bagasse followed by vapor training extraction. In the face of numerous and complex reactions involved in this synthesis, it is very complicated to define the kinetic laws from exact stoichiometry. A solution allowing to cope the problem consists in identifying an appropriate stoichiometric model. It does not attempt to represent exactly all the reaction mechanisms, but proposes a mathematical support to integrate available knowledge on the transformati...

2008-01-01

151

New synthesis routes for Sialon and Sialon-bonded ceramics

Mitochondria-localized NAD biosynthesis by nicotinamide mononucleotide adenylyltransferase in Jerusalem artichoke (Helianthus tuberosus L.) heterotrophic tissues

The use of Sialon ceramics has been restricted by the high temperature required for synthesis and the expense of the pure oxide and nitride raw materials required. For refractory applications the purity required is less demanding and it has been possible to exploit the outstanding durability of the Sialons at moderate cost. New low cost manufacturing routes are being developed by nitriding silicon metal powder at relatively low temperature with clay and various additives depending on the Sialon required. For example the introduction of carbon or fine silicon carbide allows the preparation of beta Sialons and alpha Sialons which can be stabilised by including the appropriate cations. A wide range of composite Sialon bodies with diverse properties can be prepared by a one step process. Current projects developing the synthesis routes are aimed, in the first instance, at refractory manufacture but are showing promise for more sophisticated ...

1998-09-28

152

British Library Electronic Table of Contents (United Kingdom)

Current studies in plants suggest that the content of the coenzyme NAD is variable and potentially important in determining cell fate. In cases that implicate NAD consumption, re-synthesis must occur to maintain dinucleotide pools. Despite information on the pathways involved in NAD synthesis in plants, the existence of a mitochondrial nicotinamide mononucleotide adenylyltransferase (NMNAT) activity which catalyses NAD synthesis from nicotinamide mononucleotide (NMN) and ATP has not been reported. To verify the latter assumed pathway, experiments with purified and bioenergetically active mitochondria prepared from tubers of Jerusalem artichoke (Helianthus tuberosus L.) were performed. To determine whether NAD biosynthesis might occur, NMN was added to Jerusalem artichoke mitochondria (JAM)...

2011-01-01

153

Mechanical-activation-assisted combustion synthesis of #alpha#-SiAlON in air

In-situ solid-state synthesis of Mg composite with Mg{sub 2}Si dispersoids

With the assistance of mechanical activation, yttrium-stabilized #alpha#-SiAlON was prepared by combustion synthesis in air, instead of high-pressure N_2 atmosphere for the first time. The reaction activity of metallic particles was remarkably enhanced by mechanical activation, which conduced the reduction of grain size, increased the total surface area and formation of fresh surface. The formation of #alpha#-SiAlON by combustion synthesis in air was explained by a kinetically induced reaction mechanism, in which both initial formation of #alpha#-SiAlON and following avoidance of oxidation were fulfilled by the retardation of O_2 infiltration owing to the short reaction period and fast cooling rate.

2007-06-05

154

A Logic Programming Framework for Combinational Circuit Synthesis

Super light and high performance Mg{sub 2}Si/Mg composites, which had excellent mechanical properties, were developed via the combination of solid-state synthesis and hot extrusion process. In this study, cold compacting (CP) and repeated plastic working (RPW) were firstly carried out for the mixture of Mg-Si powders, and the refinement of both Mg grains and dispersoids. Each specimen was evaluated by observation of microstructure and tensile test. As a result, it was understood that Mg{sub 2}Si dispersoids were refined and dispersed into Mg matrix, and were flowed along extrusion direction. And their mechanical properties were higher than the conventional die casting alloys. Also the effect of RPW as the improvement of properties and the decrease of synthesis temperature were confirmed. (orig.)

2005-07-01

155

Identification and characterization of noncoding small RNAs in Streptococcus pneumoniae serotype 2 strain D39.

Logic Programming languages and combinational circuit synthesis tools share a common "combinatorial search over logic formulae" background. This paper attempts to reconnect the two fields with a fresh look at Prolog encodings for the combinatorial objects involved in circuit synthesis. While benefiting from Prolog's fast unification algorithm and built-in backtracking mechanism, efficiency of our search algorithm is ensured by using parallel bitstring operations together with logic variable equality propagation, as a mapping mechanism from primary inputs to the leaves of candidate Leaf-DAGs implementing a combinational circuit specification. After an exhaustive expressiveness comparison of various minimal libraries, a surprising first-runner, Strict Boolean Inequality "<" together with constant function "1" also turns out to have small transistor-count implementations, competitive to NAND-only or NOR-only libraries. As a practical outcome, a ...

2008-01-01

156

Vectors containing a prokaryotic dihydrofolate reductase gene transform Drosophila cells to methotrexate-resistance.

We report a search for small RNAs (sRNAs) in the low-GC, gram-positive human pathogen Streptococcus pneumoniae. Based on bioinformatic analyses by Livny et al. (J. Livny, A. Brencic, S. Lory, and M. K. Waldor, Nucleic Acids Res. 34:3484-3493, 2006), we tested 40 candidates by Northern blotting and confirmed the expression of nine new and one previously reported (CcnA) sRNAs in strain D39. CcnA is one of five redundant sRNAs reported by Halfmann et al. (A. Halfmann, M. Kovacs, R. Hakenbeck, and R. Bruckner, Mol. Microbiol. 66:110-126, 2007) that are positively controlled by the CiaR response regulator. We characterized 3 of these 14 sRNAs: Spd-sr17 (144 nucleotides [nt]; decreased in stationary phase), Spd-sr37 (80 nt; strongly expressed in all growth phases), and CcnA (93 nt; induced by competence stimulatory peptide). Spd-sr17 and CcnA likely fold into structures containing single-stranded regions between hairpin structures, whereas Spd-sr37 forms a base-paired structure. Primer ...

2010-01-01

157

Translation Elongation Factor 1A Facilitates the Assembly of the Tombusvirus Replicase and Stimulates Minus-Strand Synthesis

Transformed Drosophila Kc cell lines, resistant to methotrexate, an inhibitor of de novo purine and pyrimidine synthesis, have been obtained by calcium phosphate transfection of plasmids containing...Full Text Available

1983-01-01

158

Towards hyperpolarized ¹³C-succinate imaging of brain cancer

Replication of plus-strand RNA viruses depends on host factors that are recruited into viral replicase complexes. Previous studies showed that eukaryotic translation elongation factor (eEF1A) is one...Full Text Available

2010-11-01

159

Thermodynamic modeling of integrated SOFC systems for power and hydrogen productions

We describe a novel ¹³C enriched precursor molecule, sodium 1-¹³C acetylenedicarboxylate, which after hydrogenation by PASADE-NA (Parahydrogen and Synthesis Allows Dramatically...Full Text Available

2007-05-01

160

The photoaffinity ligand [3,5-"3H] 4-azidoclonidine. Synthesis and characterization details

Electricity generation from natural gas in gas turbine units can be made substantially more efficient by preliminary methane conversion to a synthesis gas containing hydrogen and carbon monoxide and/or by the use of some of the synthesis gas produced in industry. An alternative improvement involves the introduction of solid oxide fuel cells (SOFCs) and the use of the synthesis gas in them. In this study, a modified scheme of gas turbine cycle that includes an SOFC, a membrane reactor (instead of a traditional combustion chamber), and a catalytic reactor to perform methane conversion to produce hydrogen (synthesis gas) is proposed. Variations of the energy and exergy efficiencies of the integrated system with operating conditions are provided, showing, for example, that SOFC efficiency is enhanced if the fuel cell active area is augmented. The SOFC stack efficiency can be maximized by reducing the steam ...

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161

Synthesis, Salvage, and Catabolism of Uridine Nucleotides in Boron-Deficient Squash Roots ¹

[3,5-"3H] 4-Azidoclonidine 6 was prepared from [3,5-"3H] 4-aminoclonidine 4 and has emerged as a valuable tool to study the alpha-2-adrenergic receptor. (author)

2004-07-01

162

Synthesis of deuterated eicosanoids

Previous work has provided evidence that plants may require boron to maintain adequate levels of pyrimidine nucleotides, suggesting that the state of boron deficiency may actually be one of pyrimidine...Full Text Available

1981-12-01

163

Synthesis of Rh[16aneS4-diol]"2"1"1At and Ir[16aneS4-diol]"2"1"1At complexes - possibly new precursors for labelling with astatine

Deuterated lipoxygenase and cyclooxygenase derivatives of eicosatetraenoic acid (arachidonic acid) and their metabolites are indispensable tools for organic trace analysis, biomedical studies, and mechanistic investigations on the corresponding endogenous (unlabelled) eicosanoids. Methods for the preparation of deuterated eicosanoids are reviewed.

1986-03-01

164

Synthesis of (18-/sup 14/C)octatriacontane from (1-/sup 14/C)stearic acid

... Technology; Warsaw (Poland) 978-83-909690-8-4 221 p. RADIOLOGY AND

2008-09-15

165

Synthesis and degradation of dinoflagellate plastid-encoded psbA proteins are light-regulated, not circadian-regulated

A method was developed to synthesize /sup 14/C-labelled n-alkanes for use in cigarette smoke studies. Specifically, n-(18-/sup 14/C)-octatriacontane was synthesized from 1 mCi (1-/sup 14/C)stearic acid in a radiochemical yield of 20%. The key features of this synthesis were two consecutive alkylations of tosylmethyl isocyanide followed by acid hydrolysis to (18-/sup 14/C)-19-octatriacontanone and modified Wolff-Kishner reduction to the n-alkane. After purification on silica gel 25 mg of (18-/sup 14/C)octatriacontane was obtained with a total radioactivity of 200 ..mu..Ci, a specific activity of 4.3 mCi/mmol, and a radiochemical purity in excess of 98% by thin layer radiochromatography. The method has also been applied to the synthesis of unlabeled n-pentatriacontane and is considered to be generally applicable to the synthesis of radiolabeled alkanes from radiolabeled fatty acids.

1987-01-01

166

Synthesis and characterization of new platinum(II) complexes containing oxalate and derivatives of ethylenediamine as ligands; Sintese e caracterizacao de novos complexos de platina (II) contendo oxalato e derivados da etilenodiamina como ligantes

In many dinoflagellate species, the plastid genome has been proposed to exist as a limited number of single-gene minicircles, and many genes normally found in the plastid genome are nuclear-encoded....Full Text Available

2005-02-22

167

Synthesis and characterization of a biotinylated organophosphorus ester for detection and affinity purification of a brain serine esterase: neuropathy target esterase.

No abstract prepared.

2006-07-01

168

Synthesis and characterization of PVP-coated large core iron oxide nanoparticles as an MRI contrast agent

We have synthesized a novel stable precursor, saligenin phosphorotrichloridate, which, on reaction with N-monobiotinyldiamines, generates a series of biotinylated covalent inhibitors of serine esterases....Full Text Available

1994-07-15

169

Synthesis and Phosphorylation of Maize Acidic Ribosomal Proteins1

The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI)...Full Text Available

2008-04-01

170

Stage-specific protein synthesis during early embryogenesis in Drosophila melanogaster.

The objective of this research was to determine the role of acidic ribosomal protein (ARP) phosphorylation in translation. Ribosomes (Rbs) from germinated maize (Zea mays L.) axes had...Full Text Available

1998-01-01

171

Sequential effects in two-choice reaction time tasks: Decomposition and synthesis of mechanisms

The changes in protein species synthesized during early Drosophila embryogenesis were characterized by two-dimensional electrophoresis. Of the 261 proteins scored, 68 (26%) show dramatic changes in...Full Text Available

1983-01-01

172

Role of interferon-gamma in interleukin 12-induced pathology in mice.

Performance on serial tasks is influenced by first- and higher-order sequential effects, respectively due to the immediately previous and earlier trials. As response-to-stimulus interval (RSI)...Full Text Available

2009-09-01

173

Ricin inhibition of in vitro protein synthesis by plant ribosomes

Interleukin 12 (IL-12) activates natural killer (NK) and T cells with the secondary synthesis and release of interferon-gamma (IFN-gamma) and other cytokines. IL-12-induced organ alterations are reported...Full Text Available

1995-12-01

174

Reviewing the Environmental and Human Health Knowledge Base of Carbon Nanotubes

In vitro translation systems were prepared with supernatant factors from wheat germ and 80S ribosomes from wheat germ, barley embryos, watermelon cotyledons, pea cotyledons, and castor...Full Text Available

1982-10-01

175

Regulation of hyaluronan secretion into rabbit synovial joints in vivo by protein kinase C

Carbon nanotubes (CNTs) are considered one of the most promising materials in nanotechnology, with attractive properties for many technologic applications. The different synthesis, purification, and...Full Text Available

2007-08-01

176

RU486 did not exacerbate cytokine release in mice challenged with LPS nor in db/db mice

Hyaluronan (HA) is important for joint cavitation, lubrication, volume regulation and synovial fluid drainage but little is known about the regulation of joint HA synthesis/secretion in vivo....Full Text Available

2003-07-15

177

Pyridinium based amphiphilic hydrogelators as potential antibacterial agents

BackgroundGlucocorticoids down-regulate cytokine synthesis and suppress inflammatory responses. The glucocorticoid receptor (GR) antagonist RU486 may exacerbate the inflammatory...Full Text Available

178

Prostaglandin H₂ synthase-1 and -2 expression in guinea pig gestational tissues during late pregnancy and parturition

SummaryThe numerous applications of hydrogelators have led to rapid expansion of this field. In the present work we report the facile synthesis of amphiphilic hydrogelators having a quaternary...Full Text Available

179

Prevention of chain cleavage in the chemical synthesis of 2'-silylated oligoribonucleotides.

Increased intrauterine prostaglandin (PG) production is crucial for the initiation of parturition. To investigate the mechanisms controlling intrauterine PG synthesis, we examined the expression of...Full Text Available

2005-12-15

180

Practical, Stereoselective Synthesis of Cecropia Juvenile Hormone

Strong aqueous ammonium hydroxide used to remove N-acyl protecting groups from synthetic oligoribonucleotides causes removal of some alkylsilyl protecting groups from 2'-hydroxyls and leads to chain...Full Text Available

1989-05-11

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181

The high-yield, stereoselective conversion of geraniol (3,7-dimethyl-trans-2,6-octadien-1-ol) to the insect juvenile hormone, methyl 12,14-dihomojuvenate (methyl cis-10-epoxy-3,11-dimethyl-7-ethyl-trans,...Full Text Available

1971-06-01

182

Oil from coal

Nyctohemeral Rhythm in Melatonin Response to Isoproterenol In vitro: Comparison of Rats and Syrian Hamsters,

The conversion of coal to oil can be carried out in two ways. A synthesis route and a degradation route. Each of these routes are described and several degradation processes are explored. The testing of several fuels produced from coal is also given considerations.

1986-06-01

183

NOAA ESRL Marine and Air-Sea Interaction Working Group

The in vitro response of melatonin synthesis was assessed by incubation of individual whole pineal glands for 4 hr without or with different concentrations of isoproterenol in the medium. Pineals were taken either at the end of the 14-hr light phase (day)...

1987-01-01

184

Modification of guanine bases by nucleoside phosphoramidite reagents during the solid phase synthesis of oligonucleotides.

Climate Observations Joint Air-Sea Monsoon Investigation: JASMINE Nauru '99 NTAS PACS SHEBA STRATUS VOCALS WHOTS Data Cruises Tropical Eastern Pacific Synthesis The Research...

2011-10-15

185

Microbial Anaerobic Demethylation and Dechlorination of Chlorinated Hydroquinone Metabolites Synthesized by Basidiomycete Fungi

Nucleoside 3'-phosphoramidite and chlorophosphite reagents have been found to react with the lactam function of guanine. This reaction caused unsatisfactory results when oligodeoxyribonucleotides containing...Full Text Available

1985-09-25

186

Mechanisms mediating the trophic effect of nerves during vertebrate limb regeneration

The synthesis and degradation of anthropogenic and natural organohalides are the basis of a global halogen cycle. Chlorinated hydroquinone metabolites (CHMs) synthesized by basidiomycete fungi and present...Full Text Available

2004-01-01

187

Lipoprotein lipase deficiency is associated with elevated acylation stimulating protein plasma levels

Salamanders regenerate their appendages after amputation and nerves are required for this process. Experiments were designed to test the idea that one way nerves could affect blastema cell proliferation is by influencing the metabolism of extracellular matrix (ECM) components and to identify neurotrophic factors which promote blastema cell mitosis. Temporal and spatial differences of glycosaminoglycans (GAGs) synthesis is innervated and denervated limbs were examined. Hyaluronic acid (HA) was found to be the major GAG produced during the proliferative period and chondroitin sulfate during differentiation. Denervation reduced synthesis of both these components by half. Dorsal root ganglia and fibroblast growth factor (FGF), a brain-derived mitogen, similarly doubled GAG synthesis in cultured blastemas, the FGF-effect being primarily on HA production. Histochemical and autoradiographical results confirmed the biochemical ...

1986-01-01

188

Influence of invertase activity and glycerol synthesis and retention on fermentation of media with a high sugar concentration by Saccharomyces cerevisiae.

Acylation stimulating protein (ASP, C3adesArg) is an adipose tissue derived hormone that stimulates triglyceride (TG) synthesis. ASP stimulates lipoprotein lipase (LPL) activity by relieving feedback...Full Text Available

2009-06-01

189

Induction of autolysis in nongrowing Escherichia coli.

In the past, the fermentation activity of Saccharomyces cerevisiae in substrates with a high concentration of sucrose (HSuc), such as sweet bread doughs, has been linked inversely to invertase activity...Full Text Available

1997-01-01

190

Identification of a new gene, molR, essential for utilization of molybdate by Escherichia coli.

Unless relaxation of the stringent response is achieved, all nongrowing bacteria rapidly develop resistance to autolysis induced by a variety of agents, including all classes of cell wall synthesis...Full Text Available

1986-09-01

191

Heterogeneous catalytic alcoholysis of benzonitrile

A mutation in a new gene, molR, prevented the synthesis in Escherichia coli of molybdoenzymes, including the two formate dehydrogenase isoenzymes, nitrate reductase and trimethylamine-N-oxide reductase....Full Text Available

1990-04-01

192

Hereditary Connective Tissue Diseases in Young Adult Stroke: A Comprehensive Synthesis

The authors investigate the possibility of the direct heterogeneous catalytic synthesis of ethylbenzoate from benzonitrile. The catalysts tested were oxides of aluminium, titanium, and vanadium. The main conversion product detected chromatographically was ethylbenzoate; benzaldehyde, benzamide, and benzanilide were also identified. Aluminium oxide was found to be the most effective catalyst.

1986-04-01

193

Genomic but Not Antigenomic Hepatitis Delta Virus RNA Is Preferentially Exported from the Nucleus Immediately after Synthesis and Processing

Though the genetic background of ischaemic and haemorrhagic stroke is often polygenetic or multifactorial, it can in some cases result from a monogenic disease, particularly in young adults. Besides...Full Text Available

194

Fragment condensation of peptides on teflon with radiationally grafted polystyrene

Hepatitis delta virus (HDV) contains a viroid-like circular RNA that replicates via a double rolling circle replication mechanism. It is generally assumed that HDV RNA is synthesized and remains exclusively...Full Text Available

2002-04-01

195

Fragment condensation of peptides on teflon with radiationally grafted polystyrene

In the synthesis of the peptidyl-polymer corresponding to the sequence (57-100) of the ..beta.. chain of human hemoglobin on Teflon with radiationally grafted polystyrene a comparative study was made of different methods of fragment condensation. It was shown that the most effective methods are azide condensation and condensation with the use of complex F.

1986-12-10

196

Fiscal Year 1996 Career Program Awards (by state/university)

In the synthesis of the peptidyl-polymer corresponding to the sequence (57-100) of the #beta# chain of human hemoglobin on Teflon with radiationally grafted polystyrene a comparative study was made of different methods of fragment condensation. It was shown that the most effective methods are azide condensation and condensation with the use of complex F.

197

Expression of embryonic hemoglobin genes in. cap alpha. -thalassemic and in. beta. -duplication mice

... of Viscous Liquids, Glasses, and Crystalline Materials Under Extremes of Pressure and Temperature ... Materials 9624724 ENG AZ U of Arizona Gervay Jacquelyn Synthesis of Novel Materials Utilizing Sialic ...

198

Evidence of synthesis by Lumbricus terrestris of specific substances in response to an immunization with a synthetic hapten.

The results of a study of the expression of embryonic hemoglobin genes in mice which show an imbalance of alpha and non-alpha chain synthesis are reported. (ACR)

1979-01-01

199

Evaluating the Involvement of Alternative Sigma Factors SigF and SigG in Clostridium perfringens Sporulation and Enterotoxin Synthesis?

Lumbricus terrestris (Annelid, Oligocheta) is capable of cellular- and humoral-specific reactions against natural antigens. Is this earthworm able to elaborate a response of antibody type against a...Full Text Available

1985-12-01

200

Epigallocatechin gallate inhibits HBV DNA synthesis in a viral replication - inducible cell line

Clostridium perfringens type A food poisoning is the second most commonly identified bacterial food-borne illness. Sporulation contributes to this disease in two ways: (i) most food-poisoning...Full Text Available

2010-10-01

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201

Enzymic Capacities of Purified Cauliflower Bud Plastids for Lipid Synthesis and Carbohydrate Metabolism ¹

AIM: To analyze the antiviral mechanism of Epigallocatechin gallate (EGCG) against hepatitis B virus (HBV) replication.METHODS: In this research, the HBV-replicating cell line HepG2.117 was used...Full Text Available

2011-03-21

202

Enhanced cadmium cytotoxicity in A549 cells with reduced glutathione levels is due to neither enhanced cadmium accumulation nor reduced metallothionein synthesis

Isolated cauliflower (Brassica oleracea) bud plastids, purified by isopycnic centrifugation in density gradients of Percoll, were found to be highly intact, to be practically devoid...Full Text Available

1985-10-01

203

Electrochemical Processes : Lecture Notes for a course in Applied Inorganic Chemistry

Glutathione (GSH) depletion sensitizes human lung carcinoma (A549-T27) cells to the cytotoxic effects of Cd++. The effects of GSH depletion on Cd++ accumulation and Cd++-induced metallothionein (MT) content were investigated to determine the possible role of these Cd++ responses in the sensitization process. Cellular GSH was depleted to 20% to 25% of control levels with buthionine sulfoximine (BSO), or diethyl maleate (DEM), respectively. Neither treatment significantly affected Cd++-induced accumulation of exogenous 35s-cysteine into intracellular MT in a dose-dependent fashion. The results indicate that neither enhanced Cd++ accumulation nor reduced MT synthesis plays a primary role in affecting enhanced Cd++ cytotoxicity in A549 cells with reduced GSH levels. Although BSO inhibition of GSH synthesis enhanced MT synthesis, it sensitized the cells to Cd++, which suggests an additive effect of GSH and MT in cadmium ...

204

Effects of NaCl on Proline Synthesis and Utilization in Excised Barley Leaves 1

The notes describe in detail primary and secondary galvanic cells, fuel cells, electrochemical synthesis and electroplating processes, corrosion: measurments, inhibitors, cathodic and anodic protection, details of metal dissolution reactions, Pourbaix diagrams and purification of waste water from galvanic industries.

1997-01-01

205

Effects of DGAT1 deficiency on energy and glucose metabolism are independent of adiponectin

Proline accumulation in NaCl-treated excised barley (Hordeum vulgare var Larker) leaves was studied. Leaves were treated by placing the cut end in NaCl solutions and allowing the salt...Full Text Available

1983-07-01

206

Effects of Cycling Temperatures on Fiber Metabolism in Cultured Cotton Ovules ¹

Mice lacking acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), an enzyme that catalyzes the terminal step in triacylglycerol synthesis, have enhanced insulin sensitivity and are protected from...Full Text Available

2006-08-01

207

Does Water Deficit Stress Promote Ethylene Synthesis by Intact Plants? ¹

The effects of temperature on rates of cellulose synthesis, respiration, and long-term glucose uptake were investigated using cultured cotton ovules (Gossypium hirsutum L. cv Acala...Full Text Available

1992-10-01

208

Discovering Networks of Perturbed Biological Processes in Hepatocyte Cultures

The effect of plant water deficit on ethylene production by intact plants was tested in three species, beans (Phaseolus vulgaris L.), cotton (Gossypium hirsutum L.)...Full Text Available

1990-12-01

209

DNA base mismatch detection with bulky rhodium intercalators: synthesis and applications

The liver plays a vital role in glucose homeostasis, the synthesis of bile acids and the detoxification of foreign substances. Liver culture systems are widely used to test adverse effects of drugs...Full Text Available

210

DNA Display I. Sequence-Encoded Routing of DNA Populations

The syntheses and applications of two metallointercalators, Rh(bpy)₂(chrysi)³⁺ and Rh(bpy)₂(phzi)³⁺, that target single base mismatches in DNA are...Full Text Available

2007-01-01

211

Core Synthesis Facility: Bridging the Gap between Chemistry and Biology

Recently reported technologies for DNA-directed organic synthesis and for DNA computing rely on routing DNA populations through complex networks. The reduction of these ideas to practice has been limited...Full Text Available

2004-07-01

212

Conditional deletion of Abca3 in alveolar type II cells alters surfactant homeostasis in newborn and adult mice

CF-23“The biggest stumbling block for biological sciences turned out to be synthetic organic chemistry” – Elias A. Zerhouni, Former NIH Director in Chemical...Full Text Available

2010-09-01

213

Comparison of estimation capabilities of response surface methodology (RSM) with artificial neural network (ANN) in lipase-catalyzed synthesis of palm-based wax ester

ATP-binding cassette A3 (ABCA3) is a lipid transport protein required for synthesis and storage of pulmonary surfactant in type II cells in the alveoli. Abca3 was conditionally deleted...Full Text Available

2010-05-01

214

Comparative genomics reveals 104 candidate structured RNAs from bacteria, archaea, and their metagenomes

BackgroundWax esters are important ingredients in cosmetics, pharmaceuticals, lubricants and other chemical industries due to their excellent wetting property. Since the naturally...Full Text Available

215

Chemiosmotic model for plant mitochondria

BackgroundStructured noncoding RNAs perform many functions that are essential for protein synthesis, RNA processing, and gene regulation. Structured RNAs can be detected by comparative...Full Text Available

2010-01-01

216

Cerebrospinal fluid zinc concentrations in febrile convulsions.

A balanced application of chemiosmosis to plant mitochondria is presented. Electron transport carriers are sequenced to achieve proton translocation across the inner membrane. The processes of proton translocation, use, and release are integrated to yield a description of the effective proton gradient available for metabolite transport and ATP synthesis. 27 references, 6 figures.

1983-12-01

217

An overview of PETC`s gas-to-liquids technology R&D Program

Zinc modulates the activity of glutamic acid decarboxylase, the rate limiting enzyme in the synthesis of gamma-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. Low cerebrospinal...Full Text Available

1995-10-01

218

An Arabidopsis Mutant Resistant to Thaxtomin A, a Cellulose Synthesis Inhibitor from Streptomyces SpeciesW?

The overall goal of the Gas-to-Liquids Program at the U.S. Department of Energy`s Pittsburgh Energy Technology Center (PETC) is to develop technologies for the production of hydrocarbon fuels and premium chemicals from light alkane gases. PETC`s current Gas-to-Liquids Program comprises the development of four primary advanced conversion technologies, namely, partial oxidation, oxidative coupling, oxyhydrochlorination, and novel conversion processes. Based on the current state of development, it can be concluded that, in the near future, one or more of these technologies will reach proof-of-concept demonstration. Oxyhydrochlorination is the most advanced direct conversion technology, and the synthesis of lower cost methyl chloride from natural gas would impact several commercial technologies that utilize methyl chloride as an intermediate to high value products. Technology development for the partial oxidation of methane to synthesis gas using ...

1995-04-01

219

AEROSPACE PRESSURE VESSEL DESIGN SYNTHESIS - NASA Technical ...

Thaxtomin A is a phytotoxin produced by Streptomyces scabies and other Streptomyces species, the causative agents of common scab disease in potato and other taproot...Full Text Available

2003-08-01

220

A second origin of DNA plus-strand synthesis is required for optimal human immunodeficiency virus replication.

Gerard, G. and Papirno, R. , "Ductility Ratio of Aged Beta Titanium Alloy,. I t. Transactions of the ASM, VO~. 55, NO. 3, pp. 373-388, Sept. 1962. ...

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221

A cytochrome P450 terpenoid hydroxylase linked to the suppression of insect juvenile hormone synthesis

We recently reported that human immunodeficiency virus type 1 (HIV-1) unintegrated linear DNA displays a discontinuity in its plus strand, precisely defined by a second copy of the polypurine tract...Full Text Available

1992-05-01

222

5-Fluorodeoxyuridine as an alternative to the synthesis of mixed hybridization probes for the detection of specific gene sequences.

A cDNA encoding a cytochrome P450 enzyme was isolated from a cDNA library of the corpora allata (CA) from reproductively active Diploptera punctata cockroaches. This P450 from the endocrine...Full Text Available

1998-10-27

223

2-[(4-MepyH)2]2+ - GLTRS - NASA

Synthetic complementary oligonucleotides are useful hybridization probes for the detection of mRNAs and genes encoding proteins for which only a partial amino acid sequence is known. Usually this involves...Full Text Available

1988-03-01

224

+ 2004 - The NASA Glenn Research Center Technical Report Server

Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [Clln(SCH2(CO)O)2]2-[(4-MepyH)2]2+. AUTHOR(S): ...

225

[Experimental and kinetic modeling of acid/base and redox reactions over oxide catalysts

May 31, 2011 ... Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [Clln(SCH2(CO)O)2]2-[(4-MepyH)2]2+. 284. System Mass ...

226

The high level and long lived radioactive wastes; Les dechets radioactifs a haute activite et a vie longue

The research has involved the characterization of catalyst acidity, [sup 2]D NMR studies of Bronsted acid sites, and kinetic, calorimetric, and spectroscopic studies of methylamine synthesis and related reactions over acid catalysts. Approach of this work was to explore quantitative correlations between factors that control the generation, type, strength, and catalytic properties of acid sites on zeolite catalysts. Microcalorimetry, thermogravimetric analysis, IR spectroscopy, and NMR spectroscopy have provided information about the nature and strength of acid sites in zeolites. This was vital in understanding the catalytic cycles involved in methylamine synthesis and related reactions over zeolite catalysts.

1993-01-01

227

The effect of mitochondrial dysfunction on cytosolic nucleotide metabolism

This report presents the main conclusions of 15 years of researches managed by the CEA. This report is the preliminary version of the 2005 final report. It presents the main conclusions of the actions on the axis 1 and 3 of the law of the 30 December 1991. The synthesis report on the axis 1 concerns results obtained on the long lived radionuclides separation and transmutation in high level and long lived radioactive wastes. the synthesis report on the axis 3 presents results obtained by the processes of conditioning and of ground and underground long term storage. (A.L.B.)

2005-07-01

228

Synthesis of high specific activity tritium labelled [2-{sup 3}H]-adenosine-5`-triphosphate

Several enzymes of the metabolic pathways responsible for metabolism of cytosolic ribonucleotides and deoxyribonucleotides are located in mitochondria. Studies described in this paper suggest dysfunction of the mitochondria to affect these metabolic pathways and limit the available levels of cytosolic ribonucleotides and deoxyribonucleotides, which in turn can result in aberrant RNA and DNA synthesis. Mitochondrial dysfunction has been linked to genomic instability, and it is possible that the limiting effect of mitochondrial dysfunction on the levels of nucleotides and resulting aberrant RNA and DNA synthesis in part can be responsible for this link. This paper summarizes the parts of the metabolic pathways responsible for nucleotide metabolism that can be affected by mitochondrial dysfunction.

2010-01-01

229

Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative (Clln(SCH2(CO) O)2)2-((4-MepyH)2)2+.

A procedure for high level tritium labelling at the C2-H position of adenosine 5`-triphosphate ([2-{sup 3}H]-ATP, 1), based on the tritiodehalogenation reaction of 2-bromoadenosine 5`-triphosphate (2) has been elaborated. This precursor was prepared in a six-step synthesis from guanosine. The tritiodehalogenation of (2) for three hours over palladium oxide in phosphate buffer yielded tritium labelled ATP with high specific activity, in good chemical yield. (author).

1996-08-01

230

Synthesis and Biophysical Characterization of Chlorambucil Anticancer Ether Lipid Prodrugs

The synthesis and structural characterization of a novel In(III) complex is described. The reaction between InCl3 with sodium mercapto-acetic acid, (NaSCH2(CO)OH) in 4-methylpyridine, (CH3(C5H5N), (4-Mepy)) at 25 C affords (ClIn(SCH2(CO)O)2)2- ((4-MepyH)2...

2004-01-01

231

Preparation of silver nanofluid by the submerged arc nanoparticle synthesis system (SANSS)

The synthesis and biophysical characterization of four prodrug ether phospholipid conjugates are described. The lipids are prepared from the anticancer drug chlorambucil and have C16 and C18 ether chains with phosphatidylcholine or phosphatidylglycerol headgroups. All four prodrugs have the ability to form unilamellar liposomes (86-125 nm) and are hydrolyzed by phospholipase A2, resulting in chlorambucil release. Liposomal formulations of prodrug lipids displayed cytotoxicity toward HT-29, MT-3, and ES-2 cancer cell lines in the presence of phospholipase A2, with IC50 values in the 8-36 ?M range.

2009-01-01

232

Indirect liquefaction contractors' review meeting: Proceedings

The purpose of this study is fabrication and characterization of silver nanofluid by the submerged arc nanoparticle synthesis system (SANSS). The silver metal electrodes under the electrical discharge will melt and evaporate rapidly and condense to form the nanoparticles in the lower temperature dielectric liquid and produce the suspended nanoparticle. The results showed that the spherical nanosilver particle formed in the ethylene glycol and the mean particle size is about 12.5 nm. The prepared silver nanofluid was irradiated under the 410 nm visible light, electrons could be excited from the valence band to the conduction band. The silver nanofluid more closely resembles Newtonian fluids.

2007-05-31

233

Improved synthesis of (/sup 15/N) 16-Doxyl stearic acid

The Eighth Indirect Liquefaction Contractors' Review Meeting was held November 15-17, 1988 at the Pittsburgh Hyatt Hotel. Twenty-eight presentations were made by contractors, invited speakers, and Pittsburgh Energy Technology Center R and D personnel. Six areas of research were covered: synthesis gas conversion to oxygenates; light hydrocarbon gas conversion; slurry reactor hydrodynamics; production, clean-up and conversion to hydrocarbon fuels; Fischer-Tropsch products upgrading; and, synthesis gas bioconversion. The meetings also included a panel discussion on direct methane conversion research. Individual projects are processed separately for the data bases.

1988-01-01

234

Effect of protein malnutrition on the metabolism of bone collagen in albino rats

An improved method for the synthesis of (/sup 15/N) 16-Doxyl stearate, a fatty-acid spin label, is reported. The method requires only one mole of (/sup 15/N) 2-amino-2-methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1-3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.

1987-10-01

235

ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

The effect of protein malnutrition on the metabolism of collagen in bone was studied in young female albino rats after a single injection of "3H-proline. Both specific and total radioactivities of hydroxyproline in the total collagen of the bone were found to decrease in the protein-deficient animals, indicating decreased rate of collagen synthesis. In the urine the amount of hydroxyproline excreted and total radioactivity of "3H-hydroxyproline were greatly decreased. The results of the present investigation therefore clearly indicate decreased synthesis and catabolism of collagen in bones of protein deficient animals compared to controls. (auth.).

1981-01-01

236

ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through February 1999.

1999-03-01

237

Amberlyst A-15: Reusable catalyst for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted-1H-imidazoles under MW irradiation

The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through September 1999.

1999-10-01

238

British Library Electronic Table of Contents (United Kingdom)

One-pot multi-component condensation of benzyl, aldehydes, ammonium acetate and primary amines were used for synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted-1H-imidazole derivatives under MW radiation using amberlyst A-15 as a catalysts. This catalyst has several advantages (simple work-up, low cost and reusability).

2011-01-01

239

Action of radiation on biosynthesis of hemoglobin and some of its electrophoretic fractions

Nonaqueous synthesis of metal oxide nanoparticles: Short review and doped titanium dioxide as case study for the preparation of transition metal-doped oxide nanoparticles

Biosynthesis of hemoglobin and some of its electrophoretic fractions in red cells of peripheral blood and spleen of irradiated (650 R) rats has been studied. Hemoglobin synthesis is found to be most drastically inhibited in the first and second fractions on the first and eighth days after irradiation and in the fifth and sixth fractions on the eighth day (less expressed). The synthesis is restored on the twelfth day, the process under study proceeding more slowly in the above-mentioned fractions than in others. In the course of radiation sickness, the biosynthesis of certain hemoglobin fractions varies differently in the hemoglobin-synthesizing cells of peripheral blood than in the cells of spleenic erythroid series.

240

Study of the physical and mechanical changes in packaging materials used in radiation processing - measuring methods of physical and mechanical properties

The liquid-phase synthesis of metal oxide nanoparticles in organic solvents under exclusion of water is nowadays a well-established alternative to aqueous sol-gel chemistry. In this article, we highlight some of the advantages of these routes based on selected examples. The first part reviews some recent developments in the synthesis of ternary metal oxide nanoparticles by surfactant-free nonaqueous sol-gel routes, followed by the discussion of the morphology-controlled synthesis of lanthanum hydroxide nanoparticles, and the presentation of structural peculiarities of manganese oxide nanoparticles with an ordered Mn vacancy superstructure. These examples show that nonaqueous systems, on the one hand, allow the preparation of compositionally complex oxides, and, on the other hand, make use of the organic components (initially present or formed in situ) in the reaction mixture to tailor the morphology. Furthermore, obviously ...

2008-07-15

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241

Response of photosynthesis, starch and sucrose synthesis to increased CO sub 2 and lowered O sub 2

The behaviour of the packaging materials under radiation field has a great importance in radiation processing, because, in most cases, they are finally responsible for the preservation of the beneficent changes achieved in irradiated products. For example, in radiation sterilisation and food irradiation, the packages must preserve the sterilisation, respectively the sanitisation. They must preserve also the physical barrier feature. The radiation effects on plastics were extensively studied in the last decades for nuclear industry and more recently for radiation processing. The two major effects of nuclear radiation on polymeric materials are the degradation and cross-linking. The degradation consists in breaking of macromolecules after interaction with nuclear particles, amplified by the free radicals which persist long periods, especially in crystalline polymers. Oxygen could penetrate the sample and interact with free radicals so that the degradation process continues after the ...

242

Regulation of sulfated glycosaminoglycan production by prostaglandin E2 in cultured lung fibroblasts

Increasing photosynthesis rate by raising CO{sub 2} and lowering O{sub 2} usually results in measured rates lower than those expected from the kinetics of rubisco. The failure of leaves to utilize the increased efficiency of rubisco has been attributed to limitations in rates of either starch or sucrose synthesis, which lead to a lowering of Pi and a reduction in the rate of ATP synthesis. In sugar beet leaves, increasing CO{sub 2} from 350 to 600 {mu}L L{sup {minus}1} usually increased photosynthesis only about 10%, compared to the 45% expected, and lowering O{sub 2} from 2 to 21% increased photosynthesis only an additional 20%, compared to the additional 40% expected. In some cases, raising CO{sub 2} increased photosynthesis the full 30% with no further increase occurring upon lowering O{sub 2}. In all cases, rates of starch and sucrose synthesis consistently increased in proportion to increasing photosynthesis rate. ...

1990-05-01

243

Kinetics and FTIR studies of hydrocarbon synthesis on Pd/ZSM5 catalysts. Final report

Prostaglandin E2 (PGE2) has been shown to increase the synthesis of hyaluronic acid in cultured fibroblasts by increasing the activity of hyaluronate synthetase, a group of plasma membrane-bound synthetic enzymes. We examined whether PGE2 also increased the activity of those enzyme systems involved in the synthesis of sulfated glycosaminoglycan in the human embryonic lung fibroblast. Exposure of cells to PGE2 resulted in dose-dependent increases in glucosamine incorporation into all sulfated glycosaminoglycan subtypes. PGE2 at 10(-7) mol/L increased total glycosaminoglycan per dish to 21.6 +/- 3.1 micrograms versus 12.0 +/- 2.5 micrograms in control untreated cultures. Stimulation of endogenous PGE2 production by bradykinin had a similar effect on glycosaminoglycan synthesis. To examine whether PGE2 affected sulfated glycosaminoglycan protein core production, cells were labeled with tritiated glucosamine in the presence of ...

1989-08-01

244

From coal gas to liquid product. The Topsoe TIGAS technology

Hydrocarbon synthesis during CO hydrogenation over Pd/M-ZSM5 (M=H,Na,La) and Pd/SiO/sub 2/ has been investigated. Overall activity depended on the cation-exchanged form of the support and decreased in the order Pd/La-ZSM5 = Pd/Na-ZSM5 > Pd/H-ZSM5 > Pd/SiO/sub 2/. The zeolite-supported catalysts showed high selectivity towards saturated C/sub 2/-C/sub 6/ hydrocarbons, whereas Pd/SiO/sub 2/ favored methanol production. Increasing temperature and H/sub 2//CO feed ratio led to higher reaction rates, lower yields of C/sub 2/-C/sub 6/ products, and increased lighter hydrocarbons. A mechanical mixture of Pd/SiO/sub 2/ and Na-ZSM5 showed similar product distribution as Pd/Na-ZSM5. Infrared spectra of the catalysts under reaction conditions indicate the presence of adsorbed oxygenates on the zeolite. Changes in the IR bands during the initial stages of the reaction suggest that surface species on the zeolite are not methanol synthesis ...

1986-10-15

245

Effect of transforming growth factor beta on synthesis of glycosaminoglycans by human lung fibroblasts

Conversion of coal gas into liquid products is a multistep process which involves numerous unit processes. Compared with similar processes using natural gas as feedstock, there are challenges, particularly with the gas purification. There are, however, also advantages when using a carbon-monoxide-rich gas which ultimately may result in a greatly simplified process. This paper discusses the challenges when converting a gas from an entrained coal gasifier into a liquid product and the paper presents the various options available. The following issues will be touched upon: sour gas shift and adjustment of the H{sub 2}/CO ratio; acid Gas Removal (AGR) - when and how; syngas purification; methanol and combined methanol/DME synthesis; gasoline synthesis; future integrated processes. Here, various options are available depending on the gasifier; not only dry or slurry feed but also the question of quench as well as the selected scrubbing temperature ...

2009-07-01

246

Unsymmetrically substituted n-type perylene bisimides with liquid crystalline properties

The processes of lung growth, injury, and repair are characterized by alterations in fibroblast synthesis and interstitial distribution of extracellular matrix components. Transforming growth factor beta (TGF-beta), which is postulated to play a role in modulating lung repair, alters the distribution of several matrix components such as collagen and fibronectin. We studied the effect of TGF-beta on the synthesis and distribution of the various glycosaminoglycans (GAGs) and whether these effects may explain its role in lung repair. Human diploid lung fibroblasts (IMR-90) were exposed to various concentrations of TGF-beta (0-5 nM) for variable periods of time (0-18 h). Newly synthesized GAGs were labeled with either (3H)glucosamine or (35S)sulfate. Individual GAGs were separated by size exclusion chromatography after serial enzymatic and chemical digestions and quantitated using scintillation counting. There was a dose-dependent increase in total ...

1990-09-01

247

The synthesis of 5-[1-"1"1C]ethyl barbiturates from labelled malonic esters

Perylene bisimides (PBIs) represent an important class of organic n-type semiconductors exhibiting a relatively high electron affinity among large-band-gap materials. Herein synthesis and characterization of several unsymmetrical N-substituted PBI dyes is presented and the thermotropic behavior, which is strongly affected by the respective N-substituents was investigated. Two different series of highly soluble and fluorescent derivatives have been synthesized: (1) PBIs bearing swallow-tailed alkyl chains, different in size or (2) one swallow-tailed alkyl chain and one branched oligoethylenglycolether. Synthesis of these PBIs is generally feasible by two distinct divergent synthesis approaches. Thermotropic behavior was studied by DSC, POM and XRD measurements. Inherent {pi}-{pi} interactions between cofacially orientated perylene molecules and the elliptic shape of the molecule favor the ordering in columns and ...

2009-07-01

248

Regulation of starch synthesis in potato tubers

The synthesis of ["1"1C]phenobarbital, ["1"1C]pentobarbital and["1"1C]amobarbital labelled in the 5-[1-"1"1C]ethyl position is reported. The malonic esters R- CH(CO_2Et)_2 [R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with [1-"1"1C]ethyl iodide prepared from ["1"1C]carbon dioxide. Ring closure of the 2-[1-"1"1C]ethyl-labelled malonic esters with urea afforded 5-[1-"1"1C]ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from ["1"1C] carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) ["1"1C]carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author).

249

Psychoanalysis and psychosomatics: a new synthesis.

Following tuber excision from the mother plant sucrose synthase activity fell from 3,120 to 960 nmol/g.f. wt./h within 7 days and starch synthesis ({sup 14}C sucrose incorporated into isolated discs) from 23 to 7 nmol/g.f. wt./h. While the maximum catalytic activity of sucrose synthase was more than sufficient to account for the observed rate of starch synthesis a maximum of 27% of sucrose incorporated by discs was converted into starch within 3 h. This compared with 80% conversion of {sup 14}C glucose incorporated. Tuber excision also reduced the rate of starch biosynthesis with glucose as a substrate (from 206 to 64 nmol/g.f. wt./h). The activities of UDPG-pyrophosphorylase, PPi-PFK, ATP-PFK, starch synthase and hexokinase (glucose or fructose substrates) were unaffected by tuber removal. ADPG pyrophosphorylase activity was reduced from 8,000 to 4,500 nmol/g.f. wt./h. Preliminary experiments indicate that the decline in sucrose synthease ...

1990-05-01

250

Production of radiopharmaceuticals for positron emission tomography via laboratory robotics

The usefulness of psychoanalysis to psychosomatic medicine has been limited by the longstanding assumption that the psychological disorder in psychosomatic patients resembles the conflict-based psychopathology that Freud identified in psychoneurotic patients. Recent investigations of the alexithymia construct, and the discovery that social relationships can influence health over the entire life span, have challenged this assumption and created an opportunity for a new and active involvement of psychoanalysis with psychosomatic medicine. In this contribution, I offer a synthesis of contemporary psychoanalytic observations and theories with concepts and research findings from developmental psychology, developmental biology, and the biomedical sciences. The proposed synthesis is consistent with the view that living organisms are self-regulating cybernetic systems; it also extends an evolving new psychosomatic model that conceptualizes illnesses ...

1992-01-01

251

Predicted UV properties of very metal-poor starburst

The production of radiopharmaceuticals used in positron emission tomography (PET) can require large amounts of activity at the start of synthesis in order to yield sufficient labeled material for clinical studies. Several investigators have developed remote and automated systems for the routine production of PET radiopharmaceuticals in order to reduce radiation exposure to personnel. Such devices, however, suffer from limited flexibility and can be relatively complicated in design. These systems are also limited to the production of a single or a few closely related compounds. Furthermore, changes in chemistry would require considerable modifications in hardware and/or software in order to bring the device back into operation. To circumvent the above limitations associated with the remote production of PET radiopharmaceuticals, the authors have investigated the use of laboratory robotics as a flexible alternative to the synthesis of several ...

1987-11-15

252

Polarised foreground removal at low radio frequencies using rotation measure synthesis: Uncovering the signature of hydrogen reionisation

We study the expected properties of starbursts in order to provide the point of reference for interpretation of high-z galaxy surveys and of very metal-poor galaxies. We concentrate mainly on the UV characteristics such as the ionizing spectra, the UV continuum, the Ly alpha and HeII 1640 A line and two-photon continuum emission. We use evolutionary synthesis models covering metallicities from Pop III to solar and a wide range of IMFs. We also combine the synthetic SEDs with the CLOUDY photoionization code for more accurate predictions of nebular emission, and to study possible departures from case B assumed in the synthesis models. The ionizing fluxes, UV continuum properties, and predicted Ly alpha and HeII 1640 A line strengths are presented for synthesis models covering a wider range of parameter space than our earlier calculations. Strong departures from case B predictions are obtained for Ly alpha and two-photon ...

2010-01-01

253

Nanocrystal conversion chemistry: A unified and materials-general strategy for the template-based synthesis of nanocrystalline solids

Measurement of redshifted 21-cm emission from neutral hydrogen promises to be the most effective method for studying the reionisation history of hydrogen and, indirectly, the first galaxies. These studies will be limited not by raw sensitivity to the signal, but rather, by bright foreground radiation from Galactic and extragalactic radio sources and the Galactic continuum. In addition, leakage due to gain errors and non-ideal feeds conspire to further contaminate low-frequency radio obsevations. This leakage leads to a portion of the complex linear polarisation signal finding its way into Stokes I, and inhibits the detection of the non-polarised cosmological signal from the epoch of reionisation. In this work, we show that rotation measure synthesis can be used to recover the signature of cosmic hydrogen reionisation in the presence of contamination by polarised foregrounds. To achieve this, we apply the rotation measure synthesis technique to ...

2010-01-01

254

In-situ synthesis of poly(dimethylsiloxane)-gold nanoparticles composite films and its application in microfluidic systems.

The concept of nanocrystal conversion chemistry, which involves the use of pre-formed nanoparticles as templates for chemical transformation into derivative solids, has emerged as a powerful approach for designing the synthesis of complex nanocrystalline solids. The general strategy exploits established synthetic capabilities in simple nanocrystal systems and uses these nanocrystals as templates that help to define the composition, crystal structure, and morphology of product nanocrystals. This article highlights key examples of 'conversion chemistry' approaches to the synthesis of nanocrystalline solids using a variety of techniques, including galvanic replacement, diffusion, oxidation, and ion exchange. The discussion is organized according to classes of solids, highlighting the diverse target systems that are accessible using similar chemical concepts: metals, oxides, chalcogenides, phosphides, alloys, intermetallic compounds, sulfides, and ...

2008-07-01

255

Glycosaminoglycan synthesis by subpopulations of epithelial cells from a mammary adenocarcinoma

We presented a simple approach for in-situ synthesis of poly(dimethylsiloxane) (PDMS)-gold nanoparticles composite film based on the special characteristics of PDMS itself. It is an environmentally safe synthesis method without the requirement of additional reducing/stabilizing agents. The region where the resulting gold nanoparticles distribute (in the matrix or on the surface of the polymer) and the size of the nanoparticles, as well as the colour of the free-standing films, can be simply controlled by adjusting the ratio of curing agent and the PDMS monomer. The chemical and optical properties of these composite films were studied. Using such a method, gold nanoparticle micropatterns on PDMS surfaces can be performed. And based on the gold nanoparticles micropattern, further modification with antibodies, antigens, enzymes and other biomolecules can be achieved. To verify this ability, an immobilized glucose oxidase (GOx) reactor in ...

2007-11-14

256

Fluxnet Synthesis Dataset Collaboration Infrastructure

Glycosaminoglycan synthesis by two subpopulations of a mouse mammary tumor cell line was compared. The two sublines express distinctly different growth characteristics in vitro and in vivo which indicate differences in growth regulation. Newly made glycosaminoglycans were recovered from the culture media, the cell surfaces, and residual cellular material. The cell population which grows more aggressively in vivo (+SA subline, a subline that grows in soft agarose) incorporated about 8 times more (/sup 14/C)glucosamine per cell into total glycosaminoglycans than did the slower-growing population (-SA subline, which does not grow in soft agarose). Appropriate control experiments indicated that the apparent difference in rates of synthesis was not due to discrepancies in glucosamine uptake. The main residual cellular molecule labeled was heparan sulfate, but the predominant molecule at the cell surface and in the culture fluid was hyaluronic acid. ...

1982-06-01

257

Efforts intensify to convert methane to fuels directly

The Fluxnet synthesis dataset originally compiled for the La Thuile workshop contained approximately 600 site years. Since the workshop, several additional site years have been added and the dataset now contains over 920 site years from over 240 sites. A data refresh update is expected to increase those numbers in the next few months. The ancillary data describing the sites continues to evolve as well. There are on the order of 120 site contacts and 60proposals have been approved to use thedata. These proposals involve around 120 researchers. The size and complexity of the dataset and collaboration has led to a new approach to providing access to the data and collaboration support and the support team attended the workshop and worked closely with the attendees and the Fluxnet project office to define the requirements for the support infrastructure. As a result of this effort, a new website (http://www.fluxdata.org) has been created to provide access to the Fluxnet ...

2008-02-06

258

Effect of hydrogen sulfide on chemical looping of coal-derived synthesis gas over bentonite-supported metal---oxide oxygen carriers

Until now the assumption has been that synthesis gas - mixtures of carbon monoxide and hydrogen - would be the principal source for many of the chemicals and fuels to be made via C/sub 1/ chemistry. Efforts to make cheap synthesis gas continue. But the pressure to circumvent the stranglehold that OPEC has on petroleum has caused other avenues to be explored. The current oversupply of natural gas offers an interim solution to the problem of nonpetroleum alternate source materials for C/sub 1/ chemicals production. The paper discusses the constraints and advantages of four processes: conventional steam reforming, steam reforming with oxygen secondary, partial oxidation, and catalytic partial oxidation. The end product in all cases is methanol. Direct use of methanol as a fuel has encountered numerous difficulties. conversion of methanol is, thus, of more immediate interest in C/sub 1/ chemistry. The Mobil MTG process and its second-generation ...

1987-06-01

259

Chiral salicyloxazolines as auxiliaries for the asymmetric synthesis of ruthenium polypyridyl complexes.

The effect of hydrogen sulfide (H2S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxidesssuch as iron oxide, nickel oxide, manganese oxide, and copper oxideswas investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H2S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H2S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H2S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation ...

2009-01-01

260

Chemical modification of soybean oil for lubricant

Chiral auxiliaries are promising emerging tools for the asymmetric synthesis of octahedral metal complexes. We recently introduced chiral salicyloxazolines as coordinating bidentate chiral ligands which provide excellent control over the metal-centered configuration in the course of ligand substitution reactions and can be removed afterward in an acid-induced fashion under complete retention of configuration (J. Am. Chem. Soc. 2009, 131, 9602-9603). Here reported is our detailed investigation of this sequence of reactions, affording virtually enantiopure ruthenium polypyridyl complexes. The control of the metal-centered chirality by the coordinated chiral salicyloxazolinate ligand was evaluated as a function of reaction conditions, the employed bidentate 2,2'-bipyridine and 1,10-phenanthroline ligands, and the substituent at the asymmetric 5-position of the oxazoline heterocycle. Most striking was the strong influence of the reaction solvent, with aprotic solvents ...

2010-09-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

261

Biological conversion of synthesis gas: Quarterly report [No. 3-4, July 1, 1993--September 3, 1993

This paper presents a series of structural modifications of soybean oils for lubricant. The reaction was monitored and products were confirmed by NMR and FTIR. The structural modification is carried out in four stages, (1) synthesis of soybean oil isooctyl ester from soybean oil; (2) synthesis of epoxy-soybean oil isooctyl ester from soybean oil isooctyl ester; (3) synthesis of hydroxylated products from epoxy soybean oil isooctyl ester with fatty acid; (4) esterification of the hydroxylated product with anhydride. Rheological behaviour of the products was measured. Pour points of the products (3) were observed as low as -24 C (lauric acid) and -15 C (isooctanoic acid) respectively. When the hydroxyl groups in the products were esterified with and acid anhydride, the pour points were became higher, which were -21 C (lauric acid) and -6 C (isooctanoic acid) without pour point depressant, and -27 C (lauric acid) and -24 C ...

2008-07-01

262

Automated synthesis of hypoxia imaging agent [18F]FMISO based upon a modified Explora FDG4 module

This report details the status of the Biological Conversion of Synthesis Gas Project. The following tasks are described as being completed: (1) the test plan, (2) culture development, and (3) the mass transfer/kinetic studies. The bioreactor studies (Task 4) are underway. The continuous stirred tank reactor system for the conversion of H{sub 2}S to elemental sulfur using Chlorobium thiosulfatophilum has been studied for varying light intensities. The system was also modified to include both sulfur recovery and cell recycle using ceramic membranes. Studies were also performed to observe the effects of cell recycle using a polysulfone hollow filter membrane module. Work on Task 5, limiting conditions/scale-up, includes a scale-up study with three different size reactors to establish the optimum operating conditions for hydrogen production from synthesis gas by the biological water-gas shift reaction using the photosynthetic bacterium ...

1993-10-01

263

British Library Electronic Table of Contents (United Kingdom)

A new automated synthesis procedure of 1-H-1-(3-[18F]fluoro-2-hydroxypropyl)-2-nitroimidazole ([18F]FMISO), a specific hypoxia imaging agent with great significances for the noninvasive, dynamic hypoxia evaluation of cancer, was developed by modifying Explora FDG4 module, a commercial [18F]FDG production system, in this study. Its radiochemical synthesis was carried out via two sequent reaction steps, i.e. the nucleophilic displacement of labeling precursor 1-(2?-nitro-1?-imidazolyl)-2-O-tetrahydropyranyl-3-O-tosyl-propaned iol (NITTP) with activated 18F- ion at 100 ?C for 8 minutes, and the following hydrolysis with 1M HCl at 100 ?C for 5 minutes and neutralization with 1M NaOH. Two-pot reaction with two independent separations was adopted to assure the good separation of final product vi...

2009-01-01

264

Apoferritin Templated Synthesis of Metal Phosphate Nanoparticle Labels for Electrochemical Immunoassay

Ammonia synthesis and ER-MCFC-technology - a profitable combination?

W have introduced template-synthesized metal phosphate nanoparticle labels for electrochemical immunoassay. Such use of an apoferritin template offers a simple and convenient route to prepare metallic nanoparticle labels for electrochemical immunoassays and avoid the complicated and time-consuming nanoparticle synthesis process (QD synthesis). Releasing metal ions from metal phosphate in an acetate buffer (pH 4.6) eliminates the harsh condition in the traditional metallic nanoparticle dissolution (e.g., strong acid dissolution of QDs and gold nanoparticles). This method is ultrasensitive and its DL is low to 77fM. The simultaneous detection of multiple protein targets is easily performed by using different metal phosphate nanoparticle labels (cadmium phosphate and lead phosphate). This approach can be extended to prepare multiple metal (such as zinc, lead, cadmium, copper, indium, gold, silver) phosphate nanoparticle labels or hybrid metal ...

2006-08-29

265

A plasma process for the synthesis of cubic-shaped silicon nanocrystals for nanoelectronic devices

Similar to stand-alone ER-MCFC power systems industrial ammonia production facilities include hydrogen-rich synthesis-gas production. Therefore, integration of ER-MCFC stacks in a conventional industrial ammonia plant was investigated. By preliminary process design calculations three promising process structures were evaluated: (1) ER-MCFC is fed by the ammonia plant`s steam-reformer; anode off-gas to firing (2) similar to structure 1; in this case the anode off-gas is redirected to the ammonia process (3) ER-MCFC is fed by ammonia-synthesis purge gas The results indicate that for options 1 and 3 a return-on-investment for the ER-MCFC of around 8% is achievable at a stack cost of $250/kW and a revenue of 7c/kWh. Option 2 is not profitable, because of the associated reduction in ammonia production. The degree of hydrogen-utilization in the ER-MCFC to be selected for maximum profit varies with the process structure and indicates that there is ...

1996-12-31

266

A facile method for the room-temperature synthesis of water-soluble magnetic Fe3O4 nanoparticles: Combination of in situ synthesis and decomposition of polymer hydrogel

Low pressure silane plasmas are known for their ability to synthesize silicon nanoparticles via gas phase nucleation. While in the past this particle formation has often been considered from the viewpoint of a contamination problem in semiconductor processing, we here describe a silane low pressure plasma that enables the synthesis of highly oriented, cubic-shaped silicon nanocrystals with a rather monodisperse size distribution. These silicon nanocubes have successfully been used in the manufacture of single nanoparticle vertical transistors. We discuss the advantages of this new paradigm of building nanoelectronic devices. The plasma synthesis process is characterized in more detail than in prior work. The particle nucleation, growth and shape evolution are studied. Results indicate that the process provides two spatially distinct zones: a diffuse plasma for particle growth and a constricted plasma zone for particle annealing. Measurements of ...

2007-04-21

267

British Library Electronic Table of Contents (United Kingdom)

We propose and demonstrate a facile room-temperature synthetic method for obtaining water-soluble magnetic Fe3O4 nanoparticles (NPs) by combining the in situ synthesis and decomposition of a magnetic polymer hydrogel. The Fe3O4 NPs with average diameters of 6.3-8.3nm were synthesized in a cross-linked polyacrylamide (PAAm) hydrogel by coprecipitating iron ions. The decomposition of the magnetic polymer hydrogel by an aqueous solution of sodium hydroxide led to the transfer of Fe3O4 NPs into the aqueous medium. The NPs can be dispersed stably in water for more than three months. The Fe3O4 NPs were characterized by X-ray photoelectron spectra (XPS), X-ray powder diffraction (XRD), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). The saturation magn...

2011-01-01

268

3. 3-Bis (azidomethyl) oxetane (BAMO)-based propellants. (1). ; Synthesis and characterizatio of BAMO-based polymers. BAMO kei suishin yaku no kenkyu. (1). ; BAMO kei jugotai no gosei to tokusei hyoka

Using of Itaipu hydroelectric power plant-Brazil-electric power surplus for ammonia synthesis in nitrogen fertilizers production; Utilizacao da energia junto a Usina Hidreletrica de Itaipu para a sintese de amonia para fertilizantes nitrogenados

Concerning high performance composite solid propellant BAMO and BAMO-based copolymers, synthetic method and properties of them were studied. Comparison graph of theoretical specific impulse for various propellants were shown, by that, reason why highest specific impulse BAMO was selected as direction of the study. As the orientation of synthesis, those were indicated that radicals at both ends should be hydroxyl so as urethane bonding was available, that liquid at normal temperature was required for easy handling, and that glass transition temperature is required to be low enough. Synthesis was conducted by ring-opening polymerization of ring ether detail procedures of which were explained. Measurements of properties was performed for thermochemical properties, thermal decomposition, combution heat, and friction sensitivity test to confirm safety. As the result, those were understood that thermal decomposition was divided into two phases, rapid ...

1990-08-31

269

The surface chemistry of iron Fischer-Tropsch catalysts

Secondary energy can be described as a surplus of electrical energy in a hydropower because the lower demand of energy in some period of the day and the excess of water in the reservoir during the rainy periods. This study proposes the using of the excess of energy at Itaipu Bi nacional for electrolytically hydrogen production and ammonia for nitrogenous fertilizers. Ammonia is a raw material for nitrogenous fertilizers synthesis and produced using hydrogen and nitrogen from the atmosphere. This paper determines the minimal cost of hydrogen production and the capacity of hydrogen production, with this data and according the ammonia market for nitrogenous fertilizers in the Centre/South region was estimated the better capacity of ammonia production for one plant near Itaipu. The process of ammonia production using energy excess is the most environmental acceptable. (author)

2000-07-01

270

The Path to Metallicity: Synthesis of CNO Elements inStandard BBN

The indirect conversion of coal to liquid hydrocarbons via steam gasification followed by synthesis gas (CO/H/sub 2/) chemistry has been the subject of intensive study for a number of decades. A key technological challenge facing researchers in this area is control over the product distribution during the hydrocarbon synthesis step. In the case of iron Fischer-Tropsch catalysts, it has been known that the addition of alkali to the metal catalyst has a significant impact on the product distribution. Iron catalysts treated with alkali produce less methane more alkenes and higher molecular weight products. In spite of numerous investigations, the details of this promotional effect are not understood on a molecular level. To explore the role of alkali in the surface chemistry of iron catalysts, the authors have carried out a combined surface science and catalytic kinetic study of a model iron catalyst with and without surface alkali.

1986-04-01

271

Synthesis of novel tellurium containing analogues of choline and acetylcholine and their quantitation by pyrolysis-gas chromatography-mass spectrometry.

We perform an analysis of the production of elements with mass number A {ge} 12 in a standard Big Bang Nucleosynthesis scenario. The goal is to provide a more accurate estimate of the very low and yet poorly explored abundance of such elements, relevant for the pristine Population III stars. We examine the synthesis channels for these elements in a critically revised and updated version of the Wagoner-Kawano code, as well as in a further enlarged version including four additional nuclides and a significantly extended nuclear network. Our results show no major discrepancies with the ones obtained using a smaller nuclear network. The robustness of the standard predictions--the early generation of star developed in a metal-free environment--is confirmed.

2007-02-12

272

Synthesis of N-(3-azido-4-chlorophenyl)-N'-["3H-methyl] thiourea, an efficient photoaffinity probe for the urea carrier

Methods for the synthesis and quantitation of the novel choline analogues, telluronium choline and acetyltelluronium choline, are described. An assay procedure utilizing pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) with cold trapping was developed with [2H4]telluronium choline and [2H4]acetyltelluronium choline as internal standards. The telluronium compounds were ion-pair extracted from tissue with dipicrylamine, washed with 2-butanone, and pyrolyzed prior to GC-MS analysis. The compounds were monitored using selected ion monitoring at m/z 232 and m/z 190 for acetyltelluronium and telluronium choline, respectively, and at m/z 236 and m/z 194 for the analogous deuterated internal standards. The assay was linear over a range of 20 pmol-20 nmol of compound taken through the assay. PMID:8130881

1993-12-31

273

Synthesis of I-125 labeled photoaffinity rapamycin analogs

Starting from commercial 4-chloro-3-nitroaniline, through a 5 step synthesis, 3-azido-4-chlorophenylisothiocyanate was prepared and reacted with ["3H]-methylamine. The latter was obtained by three methods: (i) ["3H]-LiA1T_4 reduction of benzylcarbamate gave rise to ["3H]-methylamine (S.A.: > 70 Ci/mmol). (ii) Catalytic reduction of HCN with "3H_2 lead to ["3H]-CH_3NH_2 (S.A.: 0.7 Ci/mmol). (III) Schmidt rearrangement of ["3H]-sodium acetate gave ["3H]-CH_3NH_2 (S.A.: 29 Ci/mmol). (author).

274

Synthesis of C-11 iodoantipyrine for positron emission tomography

Two no-carrier-added "1"2"5I-labelled photoaffinity rapamycin analogs were prepared: 7-demethoxy-7-(4-azido-3-"1"2"5I-benzyloxy) rapamycin and its C_2_8-C_2_9 seco analog. The key reactions of the synthesis were substitution of the C_7 methoxyl of rapamycin with 4-azido-3-tributylstannylbenzyloxy group, exchange of tributyltin with "1"2"5I using Na"1"2"5I and Chloramine-T, and a ZnCl_2 mediated retro-Aldol cleavage of the C_2_8-C_2_9 bond of rapamycin. (author).

275

Synthesis of 3-O-sulphamoyl glucofuranose derivatives

We have developed a method for the synthesis of C-11 iodoantipyrine. Carbon-11-labeled methyl iodide, prepared from /sup 11/CO2, was used to methylate 3-methyl-1-phenyl-2-pyrazolin-5-one to form C-11 antipyrine. Following silica-gel column chromatography and iodination, radiochemical purity of the C-11 iodoantipyrine was more than 99.5%, with a 10% yield and a specific activity of 30 mCi/mumol. Preliminary animal studies showed complete cerebral extraction and local cerebral blood-flow values that were within 4.6% of those obtained using C-14 iodoantipyrine. The C-11 analog, with positron emission tomography, will facilitate local cerebral blood-flow studies in human subjects.

1981-06-01

276

Synthesis by plasma and characterization of semiconductor compounds derived of polyacetylene; Sintesis por plasma y caracterizacion de compuestos semiconductores derivados del poliacetileno

The synthesis of 3-O-sulphamoyl derivatives of 1,2:5,6-di-O-isopropylidene-#alpha#-D-glucofuranose, 1,2-O-isopropylidene-#alpha#-D-glucofuranose, and 5,6-di-O-acetyl-1,2-O-isopropylidene-#alpha#-D-glucofuranose is described. A study of the reactions of carbohydrate chlorosulphates with azide has demonstrated the relative case with which certain chlorosulphonyloxy groups may be converted into azidosulphates. These azidosulphates could have potential synthetic value if a facile method for their conversion into sulphamoyl (aminosulphate) derivatives were available, since some sulphamoyl carbohydrates have been shown to possess antibiotic and antitrypanosomal activity. This report deals with the application of sodium borohydride and platinum oxide-hydrogen to the reduction of some 3-O-azidosulphate glucofuranose derivatives. "1H-n.m.r. spectra and infrared spectra were used.

277

Synthesis and Crystal Structures of Octahedral Metal Complexes containing the New Dianion [PhP(Se,O)Se-Se(O,Se)PPh]2-

In this work it is made a study of the structure and electric properties of chlorate polyethylene (PE-CI) with double and simple bonds obtained by continuous plasma with resistive coupling to 13.5 MHz. The synthesis conditions are power between 10 and 14 W and pressure of (6-7) x 10{sup -2} Torr. The synthesized PE-Cl in that way is soluble in acetone what indicates that probably is formed of short chains and not it shows the generalized inter crossing that is presented in some syntheses by plasma and that it can degrade the electric properties of these polymers. The IR and XPS analysis show the vibration of the C-C, C=C and C-CI bonds. The morphology of the polymer after being dissolved shows a compact and flat configuration. The electric conductivity has an approximately lineal behavior in an interval of 35 to 90% of relative humidity. (Author)

2003-07-01

278

British Library Electronic Table of Contents (United Kingdom)

The synthesis and structures of three new compounds are reported. [Mg2{PhP(Se,O)Se-Se(O,Se)PPh}2(thf)7(H2O)3] (1), [Mg{PhP(Se,O)Se-Se(O,Se)PPh}(thf)3(H2O)] (2), and [Mn{PhP(Se,O)Se-Se(O,Se)PPh}(thf)3(H2O)] (3) were prepared by treatment of Woollins reagent [PhP(Se)(m-Se)]2 with the corresponding hydrated metal acetates.

2007-01-01

279

Surface modification and characterization for dispersion stability of inorganic nanometer-scaled particles in liquid media

Structure and Optical Properties of Silicon Layers with GaSb Nanocrystals Created by Ion-Beam Synthesis

Inorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM). Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect of surface ...

2010-08-01

280

Practical superconductor development for electrical power applications

We have studied the ion-beam synthesis of GaSb nanocrystals in Si by high-fluence '' hot '' implantation of Sb and Ga ions followed by thermal annealing. The Rutherford backscattering, transmission electron microscopy/transmission electron diffraction, Raman spectroscopy and photoluminescence were used to characterize the implanted layers. It was found that the nanocrystal size increases from 5 to 60 nm in the samples annealed at 900"oC up to 20-90 nm in those annealed at 1100"oC. For the samples annealed at 900"oC a broad band in the region of 0.75-1.05 eV is registered in the photoluminescence spectra. The nature of this photoluminescence band is discussed. (author)

2011-07-01

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281

One-step synthesis of Pt-supported carbon nanohorns for fuel cell electrode by arc plasma in liquid nitrogen

Development of useful high-critical-temperature (high-{Tc}) superconductors requires synthesis of superconducting compounds; fabrication of wires, tapes, and films from these compounds; production of composite structures that incorporate stabilizers or insulators; and design and testing of efficient components. This report describes technical progress of research and development efforts aimed at producing superconducting components based on the Y-Ba-Cu, Bi-Sr-Ca-Cu, Bi-Pb-Sr-Ca-Cu, and Tl-Ba-Ca-Cu oxides systems. Topics discussed are synthesis and heat treatment of high-{Tc} superconductors, formation of monolithic and composite wires and tapes, superconductor/metal connectors, characterization of structures and superconducting and mechanical properties, and fabrication and properties of thin films. Collaborations with industry and academia are also documented. 10 figs.

1991-10-01

282

Oligoaryl Cruciform Structures as Model Compounds for Coordination-Induced Single-Molecule Switches (Eur. J. Org. Chem. 5/2010)

One-step synthesis of Pt-loaded carbon nanoparticles including single-wall carbon nanohorns (SWNHs) by arc plasma in liquid nitrogen was demonstrated using Pt-contained graphite anode. The size distribution of Pt particles can be controlled by adjusting the concentration of Pt in the graphite anode. In the observation by transmission electron microscope, the diameter of less than 5 nm of Pt particles were observed as approximately 90% among the Pt particles when Pt was contained in the anode at 1.3 at.%. When Pt concentration in the anode was decreased to 0.4 at.%, the percentage of Pt particles whose diameter is less than 5 nm decreased to approximately 60%. It was verified that the as-grown Pt-loaded products produced by this method can be useful for the power generation by polymer electrolyte fuel cell.

2006-10-10

283

British Library Electronic Table of Contents (United Kingdom)

The cover picture shows the fertile combination of synthetic chemistry and experimental physics, both permanently making central contributions to hot scientific topics in spite of being classical scientific disciplines with long-standing traditions. The displayed scientist struggles with the synthesis of cruciform structures (displayed on the black board) for single-molecule-transport investigations in a mechanically controlled break junction setup (sketched in the inset at the upper right corner). More information on the design and synthesis of the cruciform structures, such as their immobilization experiments, is found in the article by M. Calame, M. Mayor et al. on p. 833 ff. Serafin Pazdera is greatly acknowledged for the cover artwork.

2010-01-01

284

ON THE BINDING ENERGY PARAMETER #lambda# OF COMMON ENVELOPE EVOLUTION

New b-amino-a-trifluoromethyl alcohols and their exploration in the synthesis of trifluoromethylated imidazole derivatives

The binding energy parameter #lambda# plays an important role in common envelope evolution. Previous works have already pointed out that #lambda# varies throughout the stellar evolution, though it has been adopted as a constant in most of the population synthesis calculations. We have systematically calculated the binding energy parameter #lambda# for both Population I and Population II stars of masses 1-20 M _s_u_n, taking into account the contribution from the internal energy of stellar matter. We present fitting formulae for #lambda# that can be incorporated into future population synthesis investigations. We also briefly discuss the possible applications of the results in binary evolutions.

2010-06-10

285

British Library Electronic Table of Contents (United Kingdom)

Racemic and enantiomerically pure b-amino-a-trifluoromethyl alcohols were obtained via sequential nucleophilic trifluoromethylation of selected a-imino ketones, derived from arylglyoxals, and subsequent removal of the MeO or Ph(Me)CH substituent, respectively, located at the N-atom. The obtained products, containing a primary amino group, were used for the synthesis of imidazole N-oxides bearing a trifluoromethyl group as a part of the N(1)-alkyl chain. Imidazole N-oxides with an electron-withdrawing ester group at C(4) underwent spontaneous isomerization under the reaction conditions, and the corresponding imidazol-2-ones derivatives were isolated as final products.

2011-01-01

286

Nanoscale calcium bismuth mixed oxide with enhanced photocatalytic performance under visible light

British Library Electronic Table of Contents (United Kingdom)

The objective of materials research is the development of economical, safe and efficient synthesis routes that lead to the formation of a photocatalyst which is able to overcome performance problems related to particle size, crystallinity, or low surface area. Here, we report high-quality functional nanoparticles of calcium bismuth mixed oxide with 15nm nominal size corresponding to a specific surface area of 41m^2/g which were produced by single-step flame spray synthesis (FSS). The high temperature of the flame afforded creation of oxygen vacancies which were quantified by near edge X-ray absorption fine structure (NEXAFS) spectra. These two parameters, developed active surface area and created in the flame oxygen vacancies, allowed to enhance the photocatalytic activity of calcium bismu...

2010-01-01

287

Modular Design in Natural and Biomimetic Soft Materials

British Library Electronic Table of Contents (United Kingdom)

Abstract Under eons of evolutionary and environmental pressure, biological systems have developed strong and lightweight peptide-based polymeric materials by using the 20 naturally occurring amino acids as principal monomeric units. These materials outperform their man-made counterparts in the following ways: 1)-multifunctionality/tunability, 2)-adaptability/stimuli-responsiveness, 3)-synthesis and processing under ambient and aqueous conditions, and 4)-recyclability and biodegradability. The universal design strategy that affords these advanced properties involves -bottom-up- synthesis and modular, hierarchical organization both within and across multiple length-scales. The field of -biomimicry--elucidating and co-opting nature-s basic material design principles and molecular building blo...

2011-01-01

288

Lipid composition of liver microsomes and mitochondria after acute and chronic {gamma}-irradiation of rats

In situ synthesis of silver chloride nanoparticles into bacterial cellulose membranes

Acute {gamma}-irradiation of rats at doses of 100 and 270 Gy stimulates lipid synthesis and changes the lipid composition of liver cell organelles. The content of cholesterol and cholesterol esters in microsomes increased at 100 Gy and decreased at 270 Gy, with total phospholipid content remaining unchanged. The lipid content in mitochondria decreased considerably 1 h after irradiation at 270 Gy. This change was significantly less pronounced 47 h later. Under chronic {gamma}-irradiation (0.129 Gy/day), cholesterol and cardiolipin in mitochondria increased. The changes in lipid content caused by acute irradiation are presumed to be related to activated synthesis of lipids in the liver. The modification of the lipid content of mitochondria observed in chronically irradiated rats may indicate that energy-metabolizing liver cell systems are involved in the adaptation to irradiation.

1994-07-01

289

British Library Electronic Table of Contents (United Kingdom)

In situ synthesis of silver chloride (AgCl) nanoparticles was carried out under ambient conditions in nanoporous bacterial cellulose (BC) membranes as nanoreactors. The growth of the nanoparticles was readily obtained by alternating dipping of BC membranes in the solution of silver nitrate or sodium chloride followed by a rinse step. X-ray diffraction (XRD) patterns indicated the existence of AgCl nanoparticles in the BC and scanning electron microscopy (SEM) images showed that the AgCl nanoparticles well dispersed on the surface of BC and penetrated into the BC network. The AgCl nanoparticle-impregnated BC membranes exhibited high hydrophilic ability and strong antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The preparative proced...

2009-01-01

290

Impact of developing technology on indirect liquefaction

Fullerene-Derivatized Amino Acids: Synthesis, Characterization, Antioxidant Properties, and Solid-Phase Peptide Synthesis

The status of commercial technology for indirect liquefaction, as exemplified by SASOL facilities in South Africa, is reviewed. The impact of substituting more advanced gasifiers and synthesis systems is then investigated. Slagging BGC/Lurgi, Texaco and Shell-Koppers gasifiers were substituted for the Dry Ash Lurgi units used at SASOL. SASOL SYNTHOL synthesis units were replaced by slurry phase Fischer-Tropsch units employing technology pioneered by Kolbel. The advanced systems were found to have a highly favorable impact on plant efficiency, product distribution and gasoline cost. If all the projected technical improvements can be realized for indirect liquefaction, the yields of refined transportation fuels per ton of coal will approach those anticipated for direct liquefaction processes.

1980-11-01

291

British Library Electronic Table of Contents (United Kingdom)

A series of [60]fullerene-substituted phenylalanine (Baa) and lysine derivatives have been prepared by the condensation of 1,2-(4prime-oxocyclohexano)fullerene with the appropriately protected (4-amino)phenylalanine and lysine, respectively. Conversion of the imine to the corresponding amine is achieved by di-acid catalyzed hydroboration. The reduction of the imine is not accompanied by hydroboration of the fullerene cage. The [70]fullerene phenylalanine derivative has also been prepared as have the di-amino acid derivatives. The compounds were characterized by MALDI-TOF mass spectrometry, UV/Vis spectroscopy, and cyclic voltammetry. 1H and 13C NMR spectroscopy allowed the observation of diastereomers. Fullerene-substituted peptides may be synthesized on relatively large scale by solid-pha...

2007-01-01

292

Free electron laser inertial thermonuclear synthesis

Controlled Synthesis of Water-Dispersible Faceted Crystalline Copper Nanoparticles and Their Catalytic Properties

The paper proposes a concept of power driver for industrial thermonuclear reactor based on inertial thermonuclear synthesis (ITS). The circuit is based on the application of free electron laser (FEL) as a energy source for thermonuclear target compression which becomes feasible due to the application of a radically new circuit of FEL-amplifier. In the project under consideration the FEL-based laser system operates on the wave length of 0.5 micrometer. The full energy of laser radiation equals 1 MJ. This energy is delivered to the target in the pulse whose length is controlled within the range of 0.1-2 ns. The laser system brightness is 4 x 10"2"2 W cm"-"2. The FEL operating pulse repetition frequency is 40 Hz, full efficiency of electricity conversion into the energy of optical radiation is 11%. 9 refs., 3 figs., 2 tabs.

293

British Library Electronic Table of Contents (United Kingdom)

We report a solution-phase synthetic route to copper nanoparticles with controllable size and shape. The synthesis of the nanoparticles is achieved by the reduction of copper(II) salt in aqueous solution with hydrazine under air atmosphere in the presence of poly(acrylic acid) (PAA) as capping agent. The results suggest that the pH plays a key role for the formation of pure copper nanoparticles, whereas the concentration of PAA is important for controlling the size and geometric shape of the nanoparticles. The average size of the copper nanoparticles can be varied from 30 to 80 nm, depending on the concentration of PAA. With a moderate amount of PAA, faceted crystalline copper nanoparticles are obtained. The as-synthesized copper nanoparticles appear red in color and are stable for weeks, ...

2010-01-01

294

Constrained NBMPR analogue synthesis, pharmacophore mapping and 3D-QSAR modeling of equilibrative nucleoside transporter 1 (ENT1) inhibitory activity

British Library Electronic Table of Contents (United Kingdom)

Conformationally constrained analogue synthesis was undertaken to aid in pharmacophore mapping and 3D-QSAR analysis of nitrobenzylmercaptopurine riboside (NBMPR) congeners as equilibriative nucleoside transporter 1 (ENT1) inhibitors. In our previous study [J. Med. Chem. 2003, 46, 831-837], novel regioisomeric nitro-1,2,3,4-tetrahydroisoquinoline conformationally constrained analogues of NBMPR were synthesized and evaluated as ENT1 ligands. 7-NO2-1,2,3,4-Tetrahydroisoquino-2-yl purine riboside was identified as the analogue with the nitro group in the best orientation at the NBMPR binding site of ENT1. In the present study, further conformational constraining was introduced by synthesizing 5prime-O,8-cyclo derivatives. The flow cytometrically determined binding affinities indicated that the...

2008-01-01

295

Combining adjusted and unadjusted findings in mixed research synthesis

British Library Electronic Table of Contents (United Kingdom)

Abstract Rationale, aims and objectives- Finding ways to incorporate disparate types of evidence into research syntheses has the potential to build a better evidence base for clinical practice and policy. Yet conducting such mixed research synthesis studies is challenging. Researchers have to determine whether and how to use adjusted and unadjusted quantitative findings in combination with each other and with qualitative findings. Methods- Among quantitative findings, adjustment for confounding, either via study design or statistical analysis, can be a considerable source of heterogeneity. Yet there is no consensus about the best way to synthesize findings resulting from different methods for addressing confounding. When synthesizing qualitative and quantitative findings, additional consid...

2011-01-01

296

Catalytic hot gas conditioning of biomass derived product gas

Banana peel extract mediated novel route for the synthesis of palladium nanoparticles

Biomass gasification provides the potential to efficiently and economically produce a renewable source of a clean gaseous fuel suitable for power generation or synthesis gas (syngas) applications. An important side benefit of the use of biomass is the effective minimization of the primary greenhouse gas, carbon dioxide (CO{sub 2}), by providing a means to close-loop the CO{sub 2} cycle. However, high molecular weight hydrocarbon constituents (tar) in the product gas from gasification can complicate the downstream uses of the gas. This paper discusses both the development of a low cost, disposable catalyst system that can eliminate these heavy hydrocarbons from the gas and the use of the catalyst in conjunction with the Battelle high-throughput gasification process for power generation and synthesis applications. (author)

1997-12-31

297

British Library Electronic Table of Contents (United Kingdom)

Bio-inspired palladium nanoparticles were synthesized by using banana peel extract (BPE), a non-toxic eco-friendly material. Boiled, crushed, acetone precipitated, air-dried peel powder was used to reduce palladium chloride. The palladium nanoparticles were characterized by using UV-Visible spectroscopy, scanning electron microscope-energy dispersive spectra (SEM-EDS) and X-ray diffraction (XRD) analysis. Dynamic light scattering (DLS) studies revealed the average size of nanoparticles to be 50nm. Fourier transform infra red spectroscopy (FTIR) implicated the role of carboxyl, amine and hydroxyl groups in the synthetic process. This paper thus describes a novel green method for the synthesis of palladium nanoparticles.

2010-01-01

298

A wave effect enabling universal frequency scaling, monostatic passive radar, incoherent aperture synthesis, and general immunity to jamming and interference

A data centered collaboration portal to support global carbon flux analysis

A fundamental Doppler-like but asymmetric wave effect that shifts received signals in frequency in proportion to their respective source distances, was recently described as means for a whole new generation of communication technology using angle and distance, potentially replacing TDM, FDM or CDMA, for multiplexing. It is equivalent to wave packet compression by scaling of time at the receiver, converting path-dependent phase into distance-dependent shifts, and can multiply the capacity of physical channels. The effect was hitherto unsuspected in physics, appears to be responsible for both the cosmological acceleration and the Pioneer 10/11 anomaly, and is exhibited in audio data. This paper discusses how it may be exploited for instant, passive ranging of signal sources, for verification, rescue and navigation; incoherent aperture synthesis for smaller, yet more accurate radars; universal immunity to jamming or interference; and precision frequency scaling of ...

2008-01-01

299

British Library Electronic Table of Contents (United Kingdom)

Abstract Carbon climate, like other environmental sciences, has been changing. Large scale synthesis studies are becoming more common. These synthesis studies are often conducted by science teams that are geographically distributed and on data sets that are global in scale. A broad array of collaboration and data analytics tools are now available that could support these science teams. However, building tools that scientists actually use is difficult. Also, moving scientists from an informal collaboration structure to one mediated by technology often exposes inconsistencies in the understanding of the rules of engagement between collaborators. We have developed a scientific collaboration portal, called fluxdata.org, which serves the community of scientists providing and analyzing the globa...

2010-01-01

300

Use of the 2-Pyridinealdoxime/N,N?-Donor Ligand Combination in Cobalt(III) Chemistry: Synthesis and Characterization of Two Cationic Mononuclear Cobalt(III) Complexes

Use of gamma radiation for thermoplastics synthesis

The use of 2-pyridinealdoxime (paoH)/N,N′-donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)₂(L-L)]⁺,...Full Text Available

2010-01-01

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301

Transgenerational Effects of Di (2-Ethylhexyl) Phthalate in the Male CRL:CD(SD) Rat: Added Value of Assessing Multiple Offspring per Litter

Samples of vynil-benzene and vinyl acetate were irradiated with gamma rays from a sup(60)Co source. Viscosity analysis performed by using the method of Stokes showed an increase in the viscosity of the materials up to the total solidification for increased doses of gamma rays. This result characterized the formation of macromolecules of two thermal plastics, the poly (vinyl-benzene) and the poly (vinyl acetate). (author).

1991-05-27

302

Toughness of membranes applied in polymer electrolyte fuel cells

In the rat, some phthalates alter sexual differentiation at relatively low dosage levels by altering fetal Leydig cell development and hormone synthesis, thereby inducing abnormalities of the testis,...Full Text Available

2009-08-01

303

The synthesis and photophysical property of [HNEt3][Cuq2IEu(hfac)3] complex

Since several years we apply the radiation-grafting technique to prepare polymeric membranes for application in polymer electrolyte fuel cells (PEFCs). Our investigations presented here focus on changes in toughness of these materials after the various synthesis steps and the importance of membrane toughness for their application in PEFCs. (author) 2 figs., 4 refs.

1999-08-01

304

British Library Electronic Table of Contents (United Kingdom)

A new bimetallic complex [HNEt3][Cuq2IEu(hfac)3] (q^- = 8-hydroxyquinolinato, hfac^- = hexafluoroacetylacetonate) was prepared simply with only one step and characterized. Upon excitation of the organic ligand q^-, the sensitized europium luminescence was achieved.

2011-01-01

305

The role of the mesenchyme in mouse neural fold elevation. II. Patterns of hyaluronate synthesis and distribution in embryos developing in vitro

The potential of non-toxic tannins to improve the utilisation of nitrogen compounds in grass silage by ruminants

Hyaluronate (HA) distribution patterns were examined in the cranial mesenchyme underlying the mesencephalic neural folds of mouse embryos maintained in roller tube culture. Using standard image-processing techniques, the digitized images of Alcian blue-stained or 3H-glucosamine-labeled sections digested with an enzyme specific for HA, were subtracted from adjacent, undigested sections. The resultant difference picture images (DPI) accurately depicted the distribution of stained or labeled HA within the cranial mesenchyme. 3H-glucosamine-labeled HA was distributed uniformly throughout the cranial mesenchyme as 12, 18, and 24 hr of culture. By contrast, the mesenchyme was uniformly stained with Alcian blue at 12 hr, but stain intensity decreased in the central regions of the mesenchyme at 18 and 24 hr. HA distribution patterns were also examined in the cranial mesenchyme of embryos cultured in the presence of diazo-oxo-norleucine (DON), a glutamine analogue that inhibits ...

1990-06-01

306

Environmental Research Database

DescriptionInefficient utilisation of dietary nitrogen (N) by animals results in the excretion of N in varying forms, with adverse environmental consequences. Grass silage is a major component of the diet of ruminant livestock in the UK, but the protein in silage is very highly degraded as a result of the ensilage process. This results in poor capture of the silage N by rumen microbes leading to overall poor utilisation for the synthesis of milk or meat. As a result, significant quantities of dietary N are [continued...

2006-01-31

307

The liquid phase oxidation of n-butane: a search for plausible mechanisms

The chemistry of the p-block elements with thioether, selenoether and telluroether ligands.

This articles deals with an approach that has given some key information about the mechanisms of the liquid phase oxidation of butane to acetic acid. This procedure has been developed over the last 34 years; however, much of what will be discussed represents a synthesis of previous insights. Many of the observations are relatively recent and have not been previously published. In principle, this approach should be applicable to many oxidation processes. (orig.)

1998-12-31

308

Synthesis, antifungal activity and antibacterial evaluation of some 3-piperazinylmethyl-5-aryl-1H-1,2,4-triazoles.

The synthesis and structures of acyclic and macrocyclic thio-, seleno- and telluro-ether complexes of the metallic and metalloid elements of Groups 13-16 reported since 2000 are described. The diverse structures range from discrete monomers through to infinite 1-, 2- or 3-D polymers. The coordination chemistry in this area is quite different to familiar d-block chemistry and the underlying factors are explored. PMID:21706103

2011-06-27

309

Synthesis, Characterization, and Biological Activity Studies of Copper(II) Mixed Compound with Histamine and Nalidixic Acid

Some new 3-piperazinylmethyl-5-aryl-1H-1,2,4-triazoles have been prepared and tested for their antifungal and antimicrobial activity. Among them, compounds 3g and 3h exhibited higher antifungal activity than ketoconazole against Cladosporium cladosporoides and Aspergillus niger respectively. PMID:9825120

1998-10-01

310

Synthesis, Characterization and Biological Properties of Anions of Bivalent Transition Metal [Co(II) and Ni(II)] Complexes With Acylhydrazine Derived ONO Donor Schiff Bases

A mixed copper complex with deprotonated nalidixic acid (nal) and histamine (hsm) was synthesized and characterized by FTIR, UV-Vis, elemental analysis, and conductivity. The crystal structure of [Cu(hsm)(nal)H₂O]Cl·3H₂O...Full Text Available

2009-01-01

311

Synthesis of new ternary alkali metal GICs at high pressures

Some acylhydrazine derived ONO donor Schiff bases and their Co(II) and Ni(II) complexes have been prepared having the same metal ion (cation) but different anions. These synthesized metal(II)...Full Text Available

2000-01-01

312

Synthesis of 5-nitro-isatine of isonitrosoacetanilide

Graphite intercalation compounds, Rb{sub x}KC{sub 8}, Cs{sub x}KC{sub 8} and Na{sub x}KC{sub 8}, x{approx equal}1-1.3, are obtained under pressures up to 80 kbar using KC{sub 8} as the initial compound. Total contents of alkali metals in these compounds correspond to the formula MC{sub 3.5-4.0}. (orig.).

1992-07-01

313

Synthesis and stereochemical effects of pyrrolidinyl-acetylenic thieno[3,2-d]pyrimidines as EGFR and ErbB-2 inhibitors

This article describes the preparation of 5-nitroisatin and of 5-chloroisatin from isonitrosoacetanilide in a single step, using readily available and inexpensive reagents. These reactions require around 90 minutes and may be carried out as an undergraduate experiment, providing an opportunity to discuss the electrophilic aromatic substitution mechanism, as well as spectroscopic techniques for product identification. (author)

314

British Library Electronic Table of Contents (United Kingdom)

A novel class of pyrrolidinyl-acetyleneic thieno[3,2-d]pyrimidines has been identified which potently inhibit the EGFR and ErbB-2 receptor tyrosine kinases. Synthetic modifications of the pyrrolidine carbamate moiety result in a range of effects on enzyme and cellular potency. In addition, the impact of the absolute stereochemical configuration on cellular potency and oral mouse pharmacokinetics is described.

2009-01-01

315

Synthesis and properties of N,N-dialkyl-P-phenylphosphonamidous iodides

Synthesis and physicochemical properties of iron (2) perrhenates

N,N-Dialkyl-P-phenylphosphonamidous iodides are formed in the reactions of phenylphosphonus diiodide with silylated secondary amines. N,N-Dialkyl-P-phenylphosphonamidous iodides react with electrophilic reagents (methyl iodide, benzenesulfonyl azide, and phenyl azide) by the usual schemes with the formation of alkylation and oxidative-imination products. Iodine catalyzes the disproportionation of morpholinophenylphosphinous iodide into dimorphomorpholinophenylphosphinous iodide with iodine are iododimorpholinophenylphosphonium triiodide and phenylphosphonous diiodide.

1987-01-20

316

Synthesis and characterization of new platinum(II) complexes with N-alkylated ligands of longer chain containing a hydroxyl group derivatives of 1,2-etano diamine;Sintese e caracterizacao de novos complexos de platina(II) com ligantes N-alquilados de cadeia longa contendo um grupo hidroxila derivados da 1,2-etanodiamina

By dissolution of iron (2) carbonate in rhenium acid iron (2) perrhenate of the Fe(ReO/sub 4/)/sub 2/x4H/sub 2/O composition is obtained. By the method of thermal analysis the limits of tetra-, dihydrate and anhydrous iron (2) perrhenate stability are revealed. By means of X ray phase and IR spectroscopic analysis methods modification of structure in the process of synthesized salt dehydration is shown.

1983-01-01

317

Synthesis and biodistribution of labelled rho-iodo phentermine (IP), N,N,-dimethyl-rho-iodo phentermine (IDMP) and N-isopropyl-rho-iodo phentermine (IIP) in rats

No abstract prepared.

2009-07-01

318

Study of an industrial process for the synthesis of high molar mass ethylene oxide-propylene oxide copolymers usable as extrusible electrolyte; Etude d`un procede industriel de synthese de copolymeres oxyde d`ethylene-oxyde de propylene de hautes masses molaires utilisables comme electrolyte extrudable

rho-Iodo-phentermine (IP) and two of its derivatives, N,N,-dimethyl-rho-iodo-phentermine (IDMP) and N-isopropyl-rho-iodo-phentermine (IIP) were synthesized and radiolabelled with iodine by isotopic exchange. They were evaluated as potential brain imaging agents and compared to IAMP. Biodistribution studies in rats did not show that these compounds were superior to IAMP.

1987-06-01

319

State of coal gasification for production of fuel gas and synthesis gas

The aim of this work is to develop an industrial process for the synthesis of an extrusible electrolyte polymer for lithium batteries. From literature data and precise specifications the high molar mass EO/OP copolymers synthesis by coordinative catalysis has been studied in order to reach a high productivity and to minimize the treatment steps. Two catalytic systems have been studied: the aluminium alkoxide-based Vandenberg-type catalysis and the calcium alcoholate amides catalysis. The first catalysis performed in solution gives excellent results. Its adaptation to silicon supported catalysis leads to a directly usable polymer in suspension but the productivity falls down and remains to be optimized. The calcium amide catalysis in heptane suspension generates acceptable productivities but also a too high proportion of low molar masses. Various approaches have been studied to minimize this proportion due to the presence of secondary sites that ...

1996-12-31

320

Silicon electrochemistry related to the formation of porous silicon

The fundamental principles of coal gasification are discussed including the reactions, their course and influencing parameters. Said principles are illustrated considering heat balance as well as process performance. Coal gasification processes are presented which are under development on a pilot plant scale or which are approved on an industrial scale.

1984-04-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

321

We have examined in detail the electrochemistry of both n- and p-type single crystal (100) silicon in the porous silicon formation regime using a rotating Si disk apparatus with a Ag/AgCl reference electrode. Our findings impact the use and optimization of buried n- or p-type layer anodization for silicon-on-insulator (SOI) wafer synthesis. Results are briefly discussed. 3 refs.

1988-01-01

322

Sasol

Ribose metabolism and nucleic acid synthesis in normal and glucose-6-phosphate dehydrogenase-deficient human erythrocytes infected with Plasmodium falciparum.

This extended article describes Sasol, the synthetic fuel producing plant in South Africa. It produces other fuels in addition to synfuel, from local coal. A very thorough review covering all aspects of the plant is given. These include: economic; chemical and environmental. The chemistry of the processes involved, the Fischer-Tropsch synthesis and the Lurgi process are described in some detail. Consideration is also given to the establishment of new plants, research and development projects, marketing and available coal resources.

1985-06-14

323

Renewable energies in France: the main 2001 results; Les energies renouvelables en France: les principaux resultats en 2001

The metabolism of pentose-phosphate was investigated in Plasmodium falciparum-infected normal and glucose-6-phosphate dehydrogenase (G6PD)-deficient human red blood cells in vitro. 5'-Phosphoribosyl-1-pyrophosphate...Full Text Available

1986-04-01

324

RecA protein acts at the initiation of stable DNA replication in rnh mutants of Escherichia coli K-12.

This 2001 status on the use of renewable energies in France makes a synthesis of the electric and heat productions of renewable origin. It lists the primary or secondary productions of renewable energies, and details the uses corresponding to each renewable energy production source and their respective satisfaction of consumer's needs (residential, industry and agriculture sectors). A detail statistical status for 1999, 2000 and 2001 is presented in tables. (J.S.)

2002-05-01

325

Preparation of radioactive lead complexes utilizing Chelex methodology

Escherichia coli rnh mutants lacking RNase H activity are capable of recA+-dependent DNA replication in the absence of concomitant protein synthesis (stable DNA replication). In rnh dnaA::Tn10 and rnh...Full Text Available

1985-08-01

326

Preparation of radioactive lead complexes utilizing Chelex methodology

The use of Chelex resin for the synthesis of radioactive lead complexes has been explored. The process involved immobilization of {sup 203}Pb on the resin and subsequent elution of complexed lead by chelating agents. {sup 203}Pb complexes derived from meso- and racemic dimercaptosuccinic acid (meso-DMSA, rac-DMSA) were prepared and assessed for stability in vitro.

1996-11-01

327

Preparation and Characterization of Fe₃O₄/CdTe Magnetic/Fluorescent Nanocomposites and their Applications in Immuno-labeling and Fluorescent Imaging of Cancer Cells

The use of Chelex resin for the synthesis of radioactive lead complexes has been explored. The process involved immobilization of "2"0"3Pb on the resin and subsequent elution of complexed lead by chelating agents. "2"0"3Pb complexes derived from meso- and racemic dimercaptosuccinic acid (meso-DMSA, rac-DMSA) were prepared and assessed for stability in vitro.

1996-11-01

328

Polysulfone/Metal Nanocomposites by Simultaneous Photoinduced Crosslinking and Redox Reaction

The synthesis of a new kind of magnetic, fluorescent multifunctional nanoparticles (~30 nm in diameter) was demonstrated, where multiple fluorescent CdTe quantum dots (QDs) are covalently linked...Full Text Available

2010-01-19

329

British Library Electronic Table of Contents (United Kingdom)

Abstract A diacrylate polysulfone oligomer is synthesized and used as the acrylic oligomer for the in situ synthesis of noble metal/PSU nanocomposites through UV-induced simultaneous radical polymerization of acrylic functionalities and NP formation by reduction of their precursors. Thus, silver or gold NPs are formed in situ during polymer network formation. FESEM analysis of the morphology of the cured systems demonstrates that the nanoparticles of the noble metals are homogeneously distributed in the network without macroscopic agglomeration.

2011-01-01

330

Piperazine sulfonamide BACE1 inhibitors: Design, synthesis, and in vivo characterization

British Library Electronic Table of Contents (United Kingdom)

With collaboration between chemistry, X-ray crystallography, and molecular modeling, we designed and synthesized a series of novel piperazine sulfonamide BACE1 inhibitors. Iterative exploration of the non-prime side and S2prime sub-pocket of the enzyme culminated in identification of an analog that potently lowers peripheral Ab40 in transgenic mice with a single subcutaneous dose.

2010-01-01

331

Physical and functional characterization of the gene cluster encoding the polyketide phytotoxin coronatine in Pseudomonas syringae pv. glycinea.

Oxygen Inhibition of Nitrate Reductase Biosynthesis in Detached Corn Leaves via Inhibition of Total Soluble Protein Synthesis ¹

Pseudomonas syringae pv. glycinea PG4180 produces the polyketide phytotoxin coronatine. The coronatine synthesis genes in PG4180 were previously shown to reside on a 90-kb plasmid designated p4180A....Full Text Available

1992-03-01

332

Nuclear forensics in law enforcement applications

Detached first leaves of 3-day-old corn seedlings (Zea mays L. W64AxW183E) were incubated with nitrate in air or 100% O₂ in the light. Nitrate accumulation in the leaves...Full Text Available

1989-11-01

333

Novel photoaffinity label for the dopamine D2 receptor: synthesis of 4-azido-5-iodo-2-methoxy-N-1-(phenylmethyl)-4-piperidinyl benzamide (iodoazidoclebopride, IAC) and the corresponding "1"2"5I-labeled analogue ("1"2"5IAC)

Over the past several years, the Livermore Forensic Science Center has conducted analyses of nuclear-related samples in conjunction with domestic and international criminal investigations. Law enforcement officials have sought conventional and nuclear-forensic analyses of questioned specimens that have typically consisted of miscellaneous metal species or actinide salts. The investigated activities have included nuclear smuggling and the proliferation of alleged fissionable materials, nonradioactive hoaxes such as 'Red Mercury', and the interdiction of illegal laboratories engaged in methamphetamine synthesis. (author)

1998-09-01

334

Mutations at the accommodation gate of the ribosome impair RF2-dependent translation termination

... affinity azido compounds biosynthesis dopamine iodine compounds iodine

335

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Wastenet

... OnlineFirst PDF Synthesis of low-temperature, fast, single-firing body for porcelain stoneware tiles... Wei et al. Waste Manag Res.2009; 0: 0734242X09351734v1 To view this item, select one of the options below: ISWA Member Sign In ISWA Members, please sign in at ISWA to access the journal online. Sign In Already an individual subscriber? If so, please sign in to ...

336

Microwave Combustion and Sintering Without Isostatic Pressure

During protein synthesis, aminoacyl-tRNA (aa-tRNA) and release factors 1 and 2 (RF1 and RF2) have to bind at the catalytic center of the ribosome on the 50S subunit where they take part in peptide bond...Full Text Available

2010-09-01

337

Methanol -a perspective raw material for the chemical industry

This investigation involves a study of the influence of key processing parameters on the heating of materials using microwave energy. Selective and localized heating characteristics of microwaves will be utilized in the sintering of ceramics without hydrostatic pressure. In addition, combustion synthesis will be studied for the production of powders, carbides, and nitrides by combining two or more solids or a solid and a gas to form new materials. The insight gained from the interaction of microwaves with various materials will be utilized in the mobilization and subsequent redeposition of uranium.

1998-10-20

338

Metallic aggregate synthesis by radiolysis of simple or complex salt aqueous solutions. Study by electron microscope of aggregate grafting on carbon membranes

Several new development trends in the processing of methanol to various chemical products are discussed. The production of acetic acid by carbonylation of methanol will increase. In the future, methanol is expected to represent the raw material in the production of lower alkenes. The synthesis of lower alcohols, of synthetic gas (homologation), and of aromatic hydrocarbons from methanol are in the research stage.

1983-08-01

339

Metabolism and Synthesis of Indole-3-Acetic Acid (IAA) in Zea mays (Levels of IAA during Kernel Development and the Use of in Vitro Endosperm Systems for Studying IAA Biosynthesis).

French ... Title Synthese d'agregats metalliques par radiolyse de solutions aqueuses de sels simples ou complexes. Etude par M. E. du greffage des agregats sur membranes de carbone.

1987-05-20

340

Mechanism for the anti-thyroid action of minocycline

Kernels of Zea mays on an intact plant accumulate indole-3-acetic acid (IAA) at the rate of 190 ng g-1 fresh weight h-1. Of the IAA synthesized, 97% is in the esterified form and less than 3% remains...Full Text Available

1994-09-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

341

Large-scale production of biofuels through biomass (co)-gasification and Fischer Tropsch synthesis

Administration of minocycline (MN), a tetracycline antibiotic, produces a black pigment in the thyroids of humans and several species of experimental animals and antithyroid effects in rodents. We have previously shown that these effects appear to be related to interactions of MN with thyroid peroxidase (TPO), the key enzyme in thyroid hormone synthesis. In the present study, the mechanisms for inhibition of TPO-catalyzed iodination and coupling reactions by MN were investigated. 37 refs., 7 figs., 3 tabs.

1997-01-01

342

Ion conducting interpenetrated lattices for lithium generators; Reseaux interpenetres conducteurs ioniques pour generateurs au lithium

In this work the production of sustainable syngas has been investigated for use in a co-production plant for electricity and Fischer Tropsch diesel at the Willem-Alexander Centrale in Buggenum, the Netherlands, and has also been compared to the co-production of SNG. From the analysis for this specific situation it is determined that the co-production of Fischer Tropsch liquids is economically more beneficial than co-production of SNG.

2002-07-01

343

Influence of the jet pressure ratio on the performance of an AGARD single flow afterbody in the 0.60-0.95 Mach range

Interpenetrated lattices (IPL) are combinations of reticulated polymers linked together by permanent crisscross. This structure is well-adapted to combined highly incompatible pairs of polymers. The in-situ sequential method has been applied successfully to the synthesis of ethylene poly-oxides / poly-siloxanes IPLs. The results concerning the preparation of such lattices and their behaviour as solid polymer electrolytes are presented in this paper. (J.S.) 24 refs.

1996-12-31

344

Induction of Porphyrin Synthesis in Etiolated Bean Leaves by Chelators of Iron ¹²

The synthesis of experimental data concerning the effect of jet stagnation conditions on the drag of various afterbodies is presented. Jet pressure ratio effect on boattail pressure and on boundary layer separation is analyzed. This study is made for several values of the boundary layer thickness, taking into account the fact that some test rigs make its control possible by means of tangential blowing.

1975-10-01

345

Incorporation of "1"4C-linoleic acid in cerebrosides of psoriatic and normal human skin

Primary leaves of 7- to 9-day-old etiolated seedlings of Phaseolus vulgaris L. var. Red Kidney infiltrated in darkness with aqueous solutions of α, α′-dipyridyl,...Full Text Available

1974-02-01

346

Immunocytochemical techniques reveal multiple, distinct cellular pools of PtdIns4P and PtdIns(4,5)P₂

It was shown that the incorporation of "1"4C-linoleic acid in cerebrosides of normal and psoriatic human skin is different. In psoriatic epidermis and corium the turnover of this fatty acid is significantly elevated. It is suggested that in psoriasis the epidermal cell is not able to build up a regular carbohydrate sequences of lipids because the false carbohydrate chain activates the degradation of glycolipids and in compensating for the increased degradation raises the synthesis rate of glycolipids. (orig./MG).

347

Hydrothermal synthesis of tobermorite/hydroxyapatite composites

PtdIns4P is the major precursor for the synthesis of the multifunctional plasma membrane lipid, PtdIns(4,5)P₂. Yet PtdIns4P also functions...Full Text Available

2009-08-15

348

British Library Electronic Table of Contents (United Kingdom)

A tobermorite/hydroxyapatite composite was prepared by hydrothermal treatment using diatomaceous earth, ?-tricalcium phosphate and slaked lime starting materials. The XRD patterns of the composite confirmed that tobermorite and hydroxyapatite were formed after the hydrothermal process. The bending strength of the composite reached a level higher than 9?MPa after the hydrothermal process. The development of the bending strength was due to the formation of tobermorite and hydroxyapatite during the hydrothermal process. The composite had a high specific surface area due to these newly formed crystals.

2008-01-01

349

Growth differentiation factor-9 stimulates progesterone synthesis in granulosa cells via a prostaglandin E₂/EP2 receptor pathway

Growth differentiation factor-9 (GDF-9), an oocyte-secreted member of the transforming growth factor β superfamily, progesterone receptor, cyclooxygenase 2 (Cox2; Ptgs2), and the EP2 prostaglandin...Full Text Available

2000-08-29

350

Flux mapping system for TAPS 3 and 4: software perspective

The author draws the connections between the work he has done over the last ten years and related research. Connections with industry are also mentioned, and future prospects are considered. Topics discussed include research into the synthesis of olefins and into liquid phase oxidation, the catalytic effects of transition metal compounds, and coal liquefaction. (35 refs.) (In Japanese)

1982-01-01

351

Exploiting industrial robotics

The Flux Mapping System (FMS) of 540 MWe PHWR is a system, which is first of its kind used in Indian PHWRs. It is used to compute a detailed flux/power distribution of the reactor core using modal synthesis method .The paper brings out the high availability features of FMS and the software design philosophy. The paper emphasizes on framework based reusable architectural design, which simplifies and speeds up the development of data acquisition systems. (author)

2010-02-01

352

Evidence for the synthesis of {sup 267}110 produced by the {sup 59}Co + {sup 209}Bi reaction

Advances in robotic technologies reflected in commercially available and demonstrated capabilities provide exceptional alternatives to the designer of new and upgraded production processes. This paper discusses the states of the art of these technologies, describes some of the research and application engineering which has extended and exploited these capabilities, and provides some conceptual synthesis of advanced robotics and other industrial automation to hypothetical nuclear industry/laboratory tasks. Nuclear industry applications are oriented upon tasks in hazardous and contaminating environments and with hazardous materials.

1990-01-15

353

Essential Role for Cellular Phosphoglucomutase in Virulence of Type 3 Streptococcus pneumoniae

An experiment to synthesize element 110 by the {sup 59}Co+{sup 209}Bi reaction has bee performed at the SuperHILAC at the Lawrence Berkeley Laboratory. One event with many of the expected characteristics of a successful of {sup 267}110 was observed. This event corresponds to a production cross section of about one picobarn.

1994-09-01

354

Enzymic synthesis of 1-O-(indol-3-ylacetyl)-beta-D-glucose. Purification of the enzyme from Zea mays, and preparation of antibodies to the enzyme.

Synthesis of the Streptococcus pneumoniae type 3 capsule requires the pathway glucose-6-phosphate (Glc-6-P) → Glc-1-P → UDP-Glc → UDP-glucuronic acid (UDP-GlcUA)...Full Text Available

2001-04-01

355

Efficient synthesis of unsymmetric diarylalkynes from decarboxylative coupling in a continuous flow reaction system

The enzyme indol-3-ylacetylglucose synthase (UDP-glucose:indol-3-ylacetate beta-D-glucosyltransferase) catalyses the reaction: [formula: see text] This is the first step in the series of reactions leading...Full Text Available

1991-10-15

356

British Library Electronic Table of Contents (United Kingdom)

Unsymmetric diaryl alkynes were synthesized from the palladium-catalyzed decarboxylative coupling of aryl halides and propiolic acid using a continuous flow reaction system. This flow chemistry system continuously gave the desired products in moderate to good yields, and produced less byproduct than was formed in the batch reaction.

2011-01-01

357

Effect of laser induced plasma nitriding on al surface microstructure

Effect of laser induced plasma nitriding on al surface microstructure

In this paper, aluminium nitride synthesis is carried out by direct laser irradiation onto an aluminium target surface in a nitrogen containing atmosphere. The influence of various processing parameters on the microstructure of AlN thin films is investigated in order to improve their tribological properties. The main microstructural characteristics: nature, concentration, in depth distribution and morphology of various phases are studied versus processing parameters by TEM and GIXD. (author). 2 refs., 1 fig., 2 photos.

1996-12-31

358

Discovery and investigation of properties of new inorganic and organic compounds of astatine

In this paper, aluminium nitride synthesis is carried out by direct laser irradiation onto an aluminium target surface in a nitrogen containing atmosphere. The influence of various processing parameters on the microstructure of AlN thin films is investigated in order to improve their tribological properties. The main microstructural characteristics: nature, concentration, in depth distribution and morphology of various phases are studied versus processing parameters by TEM and GIXD. (author). 2 refs., 1 fig., 2 photos.

359

Design, synthesis, and testing of difluoroboron derivatized curcumins as near infrared probes for in vivo detection of amyloid-? deposits

Short review of works on astatine chemistry carried out by authors for the last thirty years are done. Discovery of single-charged cation stable in aqueous solutions is predominant attainment of authors in the branch of inorganic chemistry. The first successful synthesis of heptavalent astatine compounds is a new and significant result of the last years. New direction in the chemistry of the fifth halogen is organic chemistry of astatine

360

Cyclopeptide alkaloids. Synthesis of the ring system and its ion affinity

Amyloid-β (Aβ) deposits have been identified as key players in the progression of Alzheimer’s disease (AD). Recent evidence indicates that the deposits probably precede...Full Text Available

2009-10-28

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

361

Cumulus expansion, nuclear maturation and connexin 43, cyclooxygenase-2 and FSH receptor mRNA expression in equine cumulus-oocyte complexes cultured in vitro in the presence of FSH and precursors for hyaluronic acid synthesis

Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pattern and amide conformation of the linear peptide precursors. Both the synthetic models and a naturally occurring cyclopeptide alkaloid, ceanothine B, bind monovalent (Li"+) and divalent (Ca"2"+, Mg"2"+) cations. 4 figures, 1 table.

362

Control mechanisms operating for lipid biosynthesis differ in oil-palm (Elaeis guineensis Jacq.) and olive (Olea europaea L.) callus cultures.

The aim of this study was to investigate cumulus expansion, nuclear maturation and expression of connexin 43, cyclooxygenase-2 and FSH receptor transcripts in equine cumuli oophori during in vivo and...Full Text Available

363

Coal liquefaction in Canada: the CANMET program

As a prelude to detailed flux control analysis of lipid synthesis in plants, we have examined the latter in tissue cultures from two important oil crops, olive (Olea europaea L.) and oil palm (Elaeis...Full Text Available

2002-06-01

364

Chemicals from coal: New processes

In Canada, the federal government, through CANMET, is actively supporting coal liquefaction research and development in a number of areas. A review of the basic principles and some of the processes in the production of liquid fuels from coal is presented with reference to the characteristics of the Canadian coal resource base. An overview of the CANMET coal liquefaction contract program is presented and specific results from the batch autoclave studies carried out with Saskatchewan lignite and Nova Scotia high-volatile bituminous coals are discussed. The development of a laboratory-scale continuous-flow coal liquefaction unit at the Energy Research Laboratories of CANMET to investigate the co-processing of coal and bitumen/heavy oil is also described. In principle, there are only two routes to the production of liquid fuels from coal - a degradation route and a synthesis route. The degradation route partially breaks the complex coal structure into simpler ...

1981-02-01

365

Carbon nitride film deposition by active screen plasma nitriding

This book deals specifically with the development of new processes of converting coal into useful chemical feedstocks. The major topic in this volume is the generation of syngas and its catalytic conversion to chemicals via the Fischer-Tropsch synthesis. Describes processes involved in conversion, recent catalytic developments, and the commercially important Sasol process. Also includes chapters on the carbide process and potential of future developments in the field.

1987-01-01

366

British Library Electronic Table of Contents (United Kingdom)

Deposition of CN-based films by a novel version of active screen plasma nitriding, aiming at surface modification of polymers, is reported. The approach relies on the use of pure graphite as the grid material, which was found to act both as an active screen and as a dry source of carbon atoms for the synthesis of thin films consisting mainly of a stoichiometric CN layer with columnar-type structure and dome-like nanostructured morphology.

2011-01-01

367

Boron in nuclear medicine: New synthetic approaches to PET and SPECT. Final report, May 1, 1986--April 30, 1996

An improved synthesis of [5'-"3H]-3'-azido-3'-deoxythymidine, tritiated Zidovudine

Research is described in the development of organometallic reagents in which the boron was attached to a nonreactive organic or inorganic matrix such as polystyrene, silica, or alumina. We developed the synthesis of oxygen-15 labelled butanol, which has been found to be a valuable blood flow agent in humans. We have also developed a series of polymeric borane derivatives which were used to prepare nitrogen-13 labelled amines.

1997-08-01

368

Workshop on stems and trunks in plant form and function. Final report

[5'-"3H]-3'-Azido-3'-deoxythymidine (3) was prepared at a specific activity of 14.0 Ci/mmol by a two-step synthetic sequence involving controlled oxidation of the unlabelled compound (1) to the 5'-aldehyde (2) followed by reduction with ["3H]-NaBH_4. Purification was performed by preparative TLC. The radiochemical purity was 99.2%. (author).

369

The synthesis of (1',3'- sup 3 H)4-(4'-azido-5',6',7',8'-tetrahydro-5',5',8',8'-tetramethyl -2'-anthracenyl)benzoic acid as a probe of the retinoic acid receptor

This document is the final report on the workshop on stems and trunks in plant form and function relating to DOE grant DE-FG06-93ER20128 which took place at Oregon State University in February 1994. The resulting book is organized into four sections and a synthesis: roles of stem architecture in plant performance, roles of stems in transport and storage of water, roles of live stem cells in plant performance, and the roles of stems in preventing or reacting to response to plant injury. The synthesis stemmed from debated and discussion by the authors and a few dozen other workshop participants. The authors cover many stem functions, although the list is not exhaustive, and the focus is on terrestrial woody tree stems, primarily of temperate and boreal zones. More research on trunks, branches and twigs is important for a baseline understanding of plant biology. In the face of anticipated human-caused changes to most environments, we need not only ...

1995-03-01

370

Synthesis, structural activity-relationships, and biological evaluation of novel amide-based allosteric binding site antagonists in NR1A/NR2B N-methyl-d-aspartate receptors

The synthesis of (1',3'-{sup 3}H)4-(4'-azido-5',6',7',8'-tetrahydro-5'5'8',8'-tetramethyl-2'-anthracenyl)benzoic acid is described. This retinoid was designed as a photoaffinity probe of the receptor sites of cellular retinoic acid-binding protein and the nuclear retinoic acid receptor protein. The ({sup 3}H)azidoretinoid was prepared from 1,2,3,4-tetrahydro-1,1,4,4-tetra-methyl-7-(4-methylphenyl)-5-nitroanthracene in five steps in 15% yield (89% radiochemical purity by HPLC). {sup 1}H and {sup 3}H NMR was used to confirm the sites of {sup 3}H substitution on the ring. (author).

1990-01-01

371

British Library Electronic Table of Contents (United Kingdom)

The synthesis and structure-activity relationship analysis of a novel class of amide-based biaryl NR2B-selective NMDA receptor antagonists are presented. Some of the studied compounds are potent, selective, non-competitive, and voltage-independent antagonists of NR2B-containing NMDA receptors. Like the founding member of this class of antagonists (ifenprodil), several interesting compounds of the series bind to the amino terminal domain of the NR2B subunit to inhibit function. Analogue potency is modulated by linker length, flexibility, and hydrogen bonding opportunities. However, unlike previously described classes of NR2B-selective NMDA antagonists that exhibit off-target activity at a variety of monoamine receptors, the compounds described herein show much diminished effects against the...

2009-01-01

372

Synthesis of nanoporous carbon as a gas adsorbent by reverse replication process of silica template

Synthesis of Poly (D L-lactide-co-dl-3,6 dimethyl-morpholine, 2,5 - dione)

Porous carbon with high surface area and pore volume was prepared by a reverse replication process and its toluene equilibrium adsorption behavior was investigated. The preparation process of the porous carbon was composed of following sub-processes in series: synthesis and template preparation of silica gel, impregnation and polymerization of DVB monomer in silica template, carbonization of DVB polymer in a silica-polymer composite, and HF-assisted selective etching of silica in carbon-silica composite, The prepared porous carbon was nano porous and had ultrahigh specific surface area (2007 m{sup 2}/g) and large pore volume (3.07cm{sup 3}/g). The nanoporous carbon showed rapid toluene adsorption rate and good toluene adsorption capacity, compared with a commercial Y-type zeolite, In the present study, a reverse replication process to prepare nanoporous carbons will be introduced and its application potential as a gas adsorbent will be discussed. (author). 17 ...

2003-06-01

373

Synthesis and characterization of luminescent square-planar platinum(II) complexes containing dithiolate or dithiocarbamate ligands

Polypeptides, copolymers of #alpha#-amino acids and #alpha#-hydroxy acids, could prove to be a valuable new class of synthetic biodegradable polymers. In this paper. steps in synthesis of poly (dl-lactide-co-3, 6-dimethylmorpholine-2,5-dione) from dl-lactide and dl-3,6-dimethylmorpholine-2,5-dione was explained. dl-Lactide was synthesized from lactic acid. In the reaction of 2-bromopropionyl chloride and dl-alanine, N-(2-bromopropionyl)-dl-alanine was prepared and this material was converted to its salt and finally this salt was converted to 3,6-dimethylmorpholine-2,5-dione in a sublime r. These two monomers, that is d l-lactide and dl-3,6-dimethylmorpholine-2,5-dione was polymerized by ring-opening polymerization. F T-IR, "1H NMR, "1"3C NMR Spectra were used for structure elucidation of all intermediate compounds and final product.

2001-09-01

374

Synthesis and characterization of MoO_3 nanostructures by solution combustion method employing morphology and size control

The synthesis, characterization, and emission properties of a series of Pt(L{sub 2})(S-S) complexes are reported. The (L{sub 2}) ligands include 4,7-diphenyl-1,10-phenanthroline (Ph{sub 2}phen), 4,4{prime}-dimethyl-2,2{prime}-bipyridine (Me{sub 2}bpy), 1,5-cyclo-octadiene (COD), trimethyl phosphite (P(OMe){sub 3}), and the {alpha}-C-deprotonated form of 2-phenylpyridine (2-phpy). The (S-S) ligands include 1-(tert-butoxycarbonyl)-1-cyanoethylene-2,2-dithiolate (tbcda), 1-(diethoxyphosphinyl)-1-cyanoethylene-2,2-dithiolate (cpdt), cis-1,2-dicarbomethoxyethylene-1,2-dithiolate (met), and N,N-diethyldithio-carbamate (Et{sub 2}dtc). The complexes are readily synthesized by the addition of the dithiolate or thiolate ligand to Pt(L{sub 2})Cl{sub 2} except for Pt(P(OMe){sub 3}){sub 2}(met), which is prepared by the addition of 2 equiv of trimethyl phosphite to Pt(COD)(met).

1994-06-22

375

Synthesis and characterization of Al{sub 2}O{sub 3}/ZrO{sub 2}, Al{sub 2}O{sub 3}/TiO{sub 2} and Al{sub 2}O{sub 3}/ZrO{sub 2}/TiO{sub 2} ceramic composite particles prepared by ultrasonic spray pyrolysis

Molybdenum oxide nanostructures were synthesized utilizing the solution combustion method where the ammonium molybdate powder and an organic additive were used as precursors. Different organic additives including ethylene diamine tetra-acetic acid (EDTA), polyethylene glycol 200 (PEG 200), sorbitol and urea were used as surfactants in order to investigate the effect of additive structure on morphology and particle size of products. Also various reaction parameters such as the additive/Mo molar ratio, concentration of metal ion in solution, pH of the reaction, and temperature of the synthesis media were changed to study effects on product morphology and size. Outcomes were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction, and Transmission Electron Microscopy (TEM) techniques. Results show a variety of MoO_3 nanoparticles and nanorods produced within the size range of 10-80 nm. Furthermore, microrods and microsheets were also obtained through ...

2010-05-01

376

Synthesis and characterization of Al_2O_3/ZrO_2, Al_2O_3/TiO_2 and Al_2O_3/ZrO_2/TiO_2 ceramic composite particles prepared by ultrasonic spray pyrolysis

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been proposed.

2002-08-01

377

Some technical subjects on production of hydrocarbon fuel from synthetic gas

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been proposed.

2002-08-01

378

Silylated Co/SBA-15 catalysts for Fischer-Tropsch synthesis

Since fuel oil meeting the requirements of current petroleum products can be produced by SASOL F-T synthetic process, the manufacturing process of hydrocarbon fuel oil from the coal-derived synthesis gas, downstream processes are being successively investigated. Mobile M-gasoline, MTG, process which produces gasoline from the natural gas-derived synthesis gas through methanol went into commercial operation in New Zealand in 1986. Although the gasoline suffices the quality of commercial gasoline by both fixed bed and fluidized bed systems, the price and service life of catalyst and control of by-product durene must be improved. Any STG processes have not been completed yet and the yield and quality of gasoline are inferior to those of gasoline produced by the MTG process. Applying two-stage process, the STG process will be more economically effective.(21 refs, 4 figs, 10 tabs)

1987-06-20

379

Radiation-induced changes in the cell membrane of cultured human endothelial cells

A series of silylated Co/SBA-15 catalysts were prepared via the reaction of surface Si-OH of SBA-15 with hexamethyldisilazane (HMDS) under anhydrous, vapor-phase conditions, and then characterized by FT-IR, N2 physisorption, TG, XRD, and TPR-MS. The results showed that organic modification led to a silylated SBA-15 surface composed of stable hydrophobic Si-(CH3)3 species even after calcinations and H2 reduction at 673 K. Furthermore, the hydrophobic surface strongly influenced both metal dispersion and reducibility. Compared with non-silylated Co/SBA, Co/S-SBA (impregnation after silylation) showed a high activity, due to the better cobalt reducibility on the hydrophobic support. However, S-Co/SBA (silylation after impregnation) had the lowest FT activity among all the catalysts, due to the lower cobalt reducibility along with the steric hindrance of grafted -Si(CH3)3 for the re-adsorption of ?-olefins. -- Graphical abstract: The silylation of an SBA-15 before cobalt impregnation ...

2011-03-01

380

Nitrogen-15-labeled deoxynucleosides. 3. Synthesis of (3- sup 15 N)-2 prime -deoxyadenosine

We investigated the effect of irradiation on the kinetic characteristics of amino acid and glucose transport, and the effect on the activity of the cell membrane-bound enzyme 5'-nucleotidase and on the receptor-mediated stimulation of cyclic adenosine monophosphate synthesis by prostaglandin E1. Irradiation inhibited the sodium-dependent amino acid transport by a reduced binding of the amino acid to the transport unit. The transport of glucose, which appeared to be a sodium-independent process, was temporarily stimulated by increased maximal velocity of the transport. No effect was found on the binding to the transport unit. Irradiation increased the 5'-nucleotidase activity and decreased the prostaglandin E1-stimulated cyclic adenosine monophosphate synthesis 48 h after exposure to 20 Gy. It is concluded that irradiation decreases sodium-dependent transport by impairment of the transport unit, does not impair a ...

1985-12-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

381

Microwave induced combustion synthesis of ceramic and ceramic-metal composites

The synthesis of (3-{sup 15}N)-labeled adenine has been reported by several groups. Each of these syntheses followed essentially the same route, in which the {sup 15}N is introduced by nitration of 4-bromoimidazole under forcing conditions using ({sup 15}N)-HNO{sub 3}. The authors have devised an alternate route which uses an azo coupling reaction for introduction of the {sup 15}N and proceeds through the intermediacy of (5-{sup 15}N)-labeled 5-aminoimidazole-4-carboxamide (AICA). An unrelated route to the (5-{sup 15}N)-labeled 5-amino-imidazole ribonucleoside (AIRs) was recently reported. AICA is a versatile precursor, which is most commonly used for entry into the guanine or isoguanine families, although it is usually used as the AICA-riboside rather than the heterocycle itself. The authors have found that AICA also can be used for the adenine family by cyclization to hypoxanthine using diethoxymethyl acetate in DMF at reflux. Although these conditions are more ...

1990-10-24

382

LiPF{sub 6}. Synthesis and stability in EC/DMC and PC/DMC mixtures; LiPF{sub 6}. Synthese et stabilite dans les melanges EC/DMC et PC/DMC

Microwaves were used to induce self-propagating high temperature synthesis (SHS) in the reaction 3TiO{sub 2}+3C+(4+x)Al {yields} 3TiC+2Al{sub 2}O{sub 3}+xAl. The SHS process was studied for x = 0 and 4, using slow and fast heating rates and with and without the application of uniaxial pressure. Less than 50 watts was required to internally ignite the samples using a TE{sub 102} microwave cavity mode. Uniaxial stresses in the range of 200-1400 psi were continuously applied along the vertical axis of some of the processed samples as the SHS reactions were initiated. SEM photomicrographs clearly indicate differences in the formation of whiskers and other microstructural features in the products obtained from microwave and conventional hot wire techniques. The x = 0 samples processed with fast and slow microwave heating rates reached higher densities than the conventionally processed samples.

1995-12-31

383

H{infinity} Control Synthesis for Power System Stabilizer Design using LMI Optimization Method

Lithium hexa-fluoro-phosphate LiPF{sub 6} is recommended for the replacement of the toxic LiAsF{sub 6} and the explosive perchlorates (like LiClO{sub 4}) in rechargeable lithium electrochemical generators. The aim of this work is to develop a new method of synthesis of this salt and to check its stability with respect to carbonated solvents: ethylene carbonate (EC), propylene carbonate (PC) and dimethyl-carbonate (DMC) in already optimized EC/DMC and PC/DMC binary mixtures. Two methods using HPF{sub 6} are proposed: the first one uses the direct neutralization of this commercial acid by LiOH in aqueous, alcoholic or acetonitrile environment, while in the second one LiPF{sub 6} is obtained from pyridinium hexa-fluoro-phosphate synthesized from HPF{sub 6} using a new and simple protocol. (J.S.) 24 refs.

1996-12-31

384

Hydrothermal synthesis of semiconductive PZT solid solutions and electromechancal properties of sintered bodies. Suinetsuho ni yoru handosei PZT koyotai no gosei to shoketsutai no denki kikaiteki seishitsu

This paper presents the application of H{infinity} control synthesis using LMI optimization method to power system stabilizer(PSS) design. Since power system is usually operated under circumstance of unmeasurable uncertainties and external disturbances, the improvement of small signal stability becomes one of the most important issue for securing system stability and preventing low frequency oscillation phenomena. The LMI optimized H{infinity} PSS provides robust performance and guarantees the internal stability under these operating conditions. The global optimal H{infinity} norm is found using LMI convex optimization method which is more systematic than standard two Riccati solution method. The design results are simulated for a case study. We verified that the LMI method shown the best performance characteristic among standard Riccati method and conventional lead/lag method. (author). 19 refs., 12 figs., 3 tabs.

2000-04-01

385

Facile synthesis of additive-assisted nano goethite powder and its application for fluoride remediation

Semiconductive crystalline PZT powders doped with Bi and K were synthesized by hydrothermal reaction at 200{degree}C for 48 hours. The synthesis of the crystalline powders became difficult with an increase in doped amount of Bi and K, and in Zr/(Ti+Zr) ratio. Since substantial amounts of Pb remained in solution after hydrothermal reaction, the addition of Pb in excess of 25% was necessary to obtain the stoichiometric composition of the PZT solid solution. Bi contents in the powders were identical to those in starting materials, while K contents were less than expected ones. The electromechanical properties of the sintered bodies could be precisely measured by an admittance-curve-fitting method. The electromechanical coupling factor and piezoelectric coefficient of the sintered bodies varied with the Bi content like those of specimens prepared by solid state reaction, and showed the maximum values at a given Bi content. However, the change in conductivity with the ...

1989-10-01

386

Effect of processing variables on synthesis of b-Si3N4 particles

The present article describes a novel synthesis route for nano-sized goethite ({alpha}-FeOOH) using hydrazine sulphate as an additive. The X-ray diffraction (XRD) peaks of synthesized powder matched well with those of {alpha}-FeOOH. Transmission electron microscopy (TEM) showed the particles of irregular shape in the range of 1-10 nm. Batch adsorption experiments for fluoride uptake were performed to study the influence of various experimental parameters such as contact time (10 min to 7 h), initial fluoride concentration (10-150 mg L{sup -1}), pH (2-11.6) and the presence of competing anions. The time data fitted well to pseudo-second-order kinetic model. The fluoride removal passed through broad maxima in pH ranges of 6-8. High adsorption capacity of 59 mg g{sup -1} goethite was obtained. The isothermic data fitted well to Freundlich model. The presence of other ions namely chloride and sulphate adversely affected fluoride removal. Fluoride from contaminated ...

2010-02-15

387

British Library Electronic Table of Contents (United Kingdom)

Synthesis of highly anisotropic rod-like b-Si3N4 particles with different morphological characteristics was accomplished using commercial a-Si3N4. A number of powder mixtures were prepared with additions of various oxides (Al2O3+RE2O3, being RE=Y, La or Yb) that were subsequently heat treated in a loose powder state in the temperature range of 1750-1950degreeC and dwell times from 10 to 180min under high pressure of N2 (60MPa) in a hot isostatic press. The obtained aggregated porous bodies were lightly crushed by hand using an alumina mortar and pestle and subsequently subjected to sequential chemical treatments to eliminate the glassy phases and possible residual crystalline compounds, and to separate the synthesized b-Si3N4 particles. Resulting b-Si3N4 particles were characterized by X-r...

2008-01-01

388

Effect of increased CO sub 2 and decreased O sub 2 on photosynthesis, and carbon allocation in source leaves

Economic evaluation of the solar thermal co-production of zinc, synthesis gas, and hydrogen

The effect of raising the rate of photosynthesis on the allocation of carbon between sucrose and starch was studied by means of steady-state radiolabeling. Sugar beet source leaves on intact plants were exposed to ambient levels of CO{sub 2} and O{sub 2} for 3 hrs. Next CO{sub 2} was raised to 600 {mu}LL{sup {minus}3} for 3 hrs then O{sub 2} was decreased to 2% for 3 hrs. Rates of net carbon exchange (NCE), export, and starch and sucrose synthesis were measured. NCER increased by 30% under the combined treatments and the proportion of photosynthate allocated to starch and to sucrose did not change. When O{sub 2} concentration was lowered, NCER increased but export did not and sucrose accumulated. This observation, and our earlier conclusion that export rate usually equals sucrose synthesis rate, lead us to conclude that low O{sub 2} directly inhibited export. Low O{sub 2} treatment causes sucrose to accumulate in a sugar beet leaf which usually ...

1990-05-01

389

Does adenine incorporation into nucleic acids measure total microbial production:: a response to comments by Fuhrman et al

The use of concentrated solar energy for co-producing Zn and synthesis gas from Zn O and natural gas upgrades the calorific value of the initial reactants by 39% and, when compared to the traditional carbothermic reduction of Zn O, has the potential of reducing CO{sub 2} emissions by up to 78%. An economic assessment for an industrial thermochemical plant, 30 to 51 MW solar input, indicates that the cost of solar production of zinc ranges between 89-133 $/t (excluding the cost of Zn O feed and credit for pollution abatement), and thus might be competitive with conventional fossil-fuel-based processes at current fuel prices. The cost of solar H{sub 2}, produced by splitting water with zinc, is estimated to be in the range 0.10-0.14 $/kWh, and it is a favorable long term prospect once the cost of energy will account for the environmental externalities from fossil fuel burning such as the costs for CO{sub 2} mitigation and pollution abatement. (author) 1 fig., 2 ...

1999-08-01

390

DNA alterations photosensitized by tetracycline and some of its derivatives

The uptake and incorporation of (/sup 3/H)adenine as a measure of total microbial (bacteria and unicellular algae) nucleic acid synthesis depends on the validity of several assumptions. A unique characteristic of the (/sup 3/H)adenine method is the ability to measure the specific radioactivity (nCi pmol/sup -1/) of the immediate precursor pool of the adenine incorporated into nucleic acids. This measurement permits correction for isotope dilution when the added radiotracer mixes with exogenous pools of structurally related compounds before uptake and with endogenous pools after transport into the cells. The immediate precursors to (/sup 3/H)adenine incorporation into cellular RNA and DNA are ATP and dATP. Since the intracellular dATP pool is in isotopic equilibrium with the ATP pool, one can determine the specific radioactivity of both precursor pools by measuring that of the intracellular ATP pool. If the specific activity of the precursor pool is not measured, ...

1986-11-01

391

CoSi_2 nanostructures by writing FIB ion beam synthesis

Bacteriophage M13 mp10 DNA were irradiated with near-UV light in the presence of tetracycline derivatives and primed with synthetic oligonucleotide to be used for DNA synthesis using Escherichia coli DNA polymerase. Chain terminations were observed by denaturing polyacrylamide gel electrophoresis and mapped precisely. All the synthesis stops occurred before or at the level of guanine residues, showing that the photoreaction mediated by tetracycline derivatives led to a preferential alteration of guanine residues. These lesions were demonstrated to be induced in DNA through a pathway involving singlet oxygen. Tetracycline derivatives also photoinduced the breakage of the DNA sugar-phosphate backbone monitored by the conversion of supercoiled phi X174 DNA to a relaxed form. This lesion was shown to be initiated by hydroxyl radicals. The production of this free radical has been confirmed by electron paramagnetic resonance (EPR) spin trapping ...

1986-06-01

392

Biological conversion of synthesis gas. Limiting conditions/scale-up

A mass separated focused ion beam (FIB) is a very useful tool to fabricate nanostructures by writing implantation within an ion beam synthesis process. In these investigations the IMSA-OrsayPhysics FIB, equipped with a Co_3_6Nd_6_4 alloy liquid metal ion source, was applied. Si(100) and (111) wafers were implanted with 60 keV Co"+"+ ions in the dose range of 2 . 10"1"6 to 2 . 10"1"7 cm"-"2. Implantation parameters were investigated, like pixel dwell time, relaxation time (time between two cycles), dose rate as well as the pixel overlapping factor. The subsequent annealing was done in a two step process, namely 600 deg. C for 60 min and 1000 deg. C for 30 min in a N_2 ambient. The results obtained by SEM investigations in terms of continuous nanowire structures following the direction and interrupted CoSi_2 pattern in the direction show a clear dependence on the time scale as well as the scanning mode of the irradiation. Structure sizes as small as 10 nm are ...

2006-07-01

393

Alteration of the enterohepatic recirculation of bile acids in rats after exposure to ionizing radiation

The purpose of this research is to develop a technically and economically feasible process for biologically producing H(sub 2) from synthesis gas while, at the same time, removing harmful sulfur gas compounds. Six major tasks are being studied: 1. Culture development, where the best cultures are selected and conditions optimized for simultaneous hydrogen production and sulfur gas removal; 2. Mass transfer and kinetic studies in which equations necessary for process design are developed; 3. Bioreactor design studies, where the cultures chosen in Task 1 are utilized in continuous reaction vessels to demonstrate process feasibility and define operating conditions; 4. Evaluation of biological synthetic gas conversion under limiting conditions in preparation for industrial demonstration studies; 5. Process scale-up where laboratory data are scaled to larger-size units in preparation for process demonstration in a pilot-scale unit; and 6. Economic evaluation, where ...

1993-09-01

394

A new solid-state process for synthesis of LiMn{sub 1.5}Ni{sub 0.5}O{sub 4-{delta}} spinel

The aim of this work was to study acute alterations of the enterohepatic recirculation (EHR) of bile acids 3 days after an 8-Gy radiation exposure in vivo in the rat by a washout technique. Using this technique in association with HPLC analysis, the EHR of the major individual bile acids was determined in control and irradiated animals. Ex vivo ileal taurocholate absorption was also studied in Ussing chambers. Major hepatic enzyme activities involved in bile acid synthesis were also measured. Measurements of bile acid intestinal content and intestinal absorption efficiency calculation from washout showed reduced intestinal absorption with significant differences from one bile acid to another: absorption of taurocholate and tauromuricholate was decreased, whereas absorption of the more hydrophobic taurochenodeoxycholate was increased, suggesting that intestinal passive diffusion was enhanced, whereas ileal active transport might be reduced. Basal hepatic secretion ...

2004-02-01

395

The influence of plastic materials on the formation of tars in the gasification of urban waste wood

A new two-step solid-state process was developed for synthesis of a pure phase 4.7 V LiMn{sub 1.5}Ni{sub 0.5}O{sub 4-{delta}} (LMNO) spinel of good electrochemical properties. This process which was based on formation of stable Ni{sub 1-x}Mn{sub 2}O{sub 4-{delta}} (x {<=} 0.33) spinel followed by subsequent lithiation, demonstrated the emerging of LiMn{sub 1.5}Ni{sub 0.5}O{sub 4-{delta}} frame work at temperatures of as low as 350 C. During this lithiation process, migration of metal ions (Ni/Mn) from partially occupied tetrahedral 8a sites (in Ni{sub 0.67}Mn{sub 2}O{sub 4-{delta}}) toward octahedral 16d site occurred. The resultant spinel material displayed low irreversible loss, a 97% columbic efficiency and 6% loss in discharge capacity after 100 cycles at 60 C. (author)

2010-08-01

396

The effect of the precursor nanopowder size on the thermoelectric properties of nanostructured Bi-Sb-Te bulk materials

Gasification experiments were performed using urban waste wood (Altholz) with additions of polymers typical for separately collected waste plastics. The resulting tar product distributions are discussed in this paper. The amount of tars is shown to be a function of operation parameters of the gasifier as well as the fuel. Plastics admixture yields higher concentrations of aromatic tar compounds in the gases, even if the plastic used is not aromatic in its structure. Such mixtures can be gasified for the production of synthesis gas, but clearly a larger effort will be required in cleaning the gases. (author)

2001-03-01

397

Synthesis of polyacrylonitrile (PAN) with different stereoregularity by urea radiation inclusion polymerization and its application to carbon fiber

This paper presents the effect of precursor powder size on the thermoelectric properties of sintered nanostructured bulk materials. The transport properties of the nanostructured bulk show a dramatic size effect. There are a lower thermal and electrical conductivity for the bulk with smaller nanopowders. The dimensionless figure-of merit values (ZT) of almost all the samples are much lower than those of the list reported data in the paper because the decrease in the thermal conductivity is counteracted by the reduction in the electrical conductivity and the Seebeck coefficient. The combination route of hydro/solvothermal synthesis and spark-plasma-sintering method provide a well controlled way to significantly reduce the thermal conductivity.

2010-12-15

398

Synthesis of model compounds for coal liquefaction research: Final report, June 21, 1990--July 30, 1993

Application to carbon fiber started in this Year. In this paper, a spinning and calcination process are explained. Fiber was obtained by wet spinning of the PAN solution. Ten solvents were tested and the results proved that dimethyl sulfoxide (DMSO) was the best solvent. Glycerine was used as a coagulating bath. The thin fiber (10 to 50 denier) was produced under the conditions of about 20wt% concentration at about 110degC. Heat-treat temperature was about 270 to 275degC. The viscosity-tacticity relationship and T{sub sol} vs. inverse tacticity were shown in the paper. (S.Y.)

1998-01-01

399

Synthesis of histidine-stabilized cadmium sulfide quantum dots: Study of their fluorescence behaviour in the presence of adenine and guanine

The objectives of this project were to develop feasible synthetic routes to produce (1) 4(4{prime}-hydroxy-5{prime}6{prime},7{prime}8{prime}-tetrahydro-1{prime}-naphthylmethyl)-6-methyldibenzothiophene, and (2) a 1-hydroxynaphthalene-dibenzothiophene polymer. These compounds are thought to be representative of sulfur containing molecules in coal. The program was divided into two technical tasks. Unfortunately, the attempted syntheses of these compounds was unsuccessful due to their unusual reactivities. Attempted synthetic routes and possible future routes are described, and Appendix A lists the compounds that were synthesized during this program.

1993-07-01

400

British Library Electronic Table of Contents (United Kingdom)

Cadmium sulfide particles have been synthesized in the aqueous medium using the amino acid histidine as a stabilizing agent. These particles demonstrate the phenomenon of size quantization effect. The fluorescence of histidine-stabilized CdS was found to be enhanced and quenched by the addition of DNA bases adenine and guanine, respectively. The fluorescence enhancement of CdS in the presence of adenine has been explained on the basis of interaction between the quantum dot stabilizer and the amino group of adenine. Quenching of CdS fluorescence by guanine occurs due to interaction of the substrate with the quantum dot surface.

2010-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

401

Synthesis and tissue distribution study of iodine-labeled benzyl- and xylylamines

Synthesis and scintillation properties of GdCl_3:Ce"3"+ (Gd_1_-_xCe_xCl_3_,x = 0.005-0.08)

Four /sup 125/I labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogues of the previously reported /sup 75/Se labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after intravenous injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 approximately 18 h), which is desirable for brain imaging. In contrast, the benzylamine is rapidly cleared from brain tissue (t1/2 approximately 15 min).

1982-07-01

402

Synthesis and photonic band calculations of NCP face-centered cubic photonic crystals of TiO2 hollow spheres.

Single crystals of GdCl_3 doped with different concentrations of Ce"3"+ have been grown using the Bridgman-Stockbarger technique and their luminescence and scintillation properties were investigated. The luminescence spectrum of GdCl_3:Ce"3"+ is complex and consists of two bands with maxima at 350 nm and 370 nm. The maximal light yield in GdCl_3:Ce"3"+ was observed at #approx#1 mol% of Ce"3"+ (more than 38 000 ph/MeV).

2009-07-08

403

Synthesis and characterization of pH-dependent glycol chitosan and dextran sulfate nanoparticles for effective brain cancer treatment.

With the help of self-assembly, thermal sintering, selective etching techniques and sol-gel process, the non-close packed (ncp) face-centered cubic (fcc) photonic crystals of titanium dioxide (TiO2) hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The photonic bandgap calculations indicate that the ncp structure of TiO2 hollow spheres was easier to open the pseudogaps than close packed system at the lowest energy. PMID:17097102

2006-10-21

404

Synthesis and characterization of nickel(II), chromium(III), cobalt(II), copper(II), zinc(II), and cadmium(II) complexes with isatin- isonicotinoylhydrazone

A novel drug delivery system for the treatment of brain tumors was formulated by methotrexate (MTX)-loaded polymeric nanoparticles (NPs) based on Glycol chitosan (GCS) and Dextran sulfate (DS). The physicochemical properties of resulting particles were investigated, evidencing the contribution of these nanoparticles for brain targeting. In vitro release of MTX was also evaluated. The GCS-DS nanoparticles have been developed based on the modulation of ratio show promise as a system for controlled delivery of the drug to the brain. PMID:21782844

2011-07-19

405

Synthesis and characterization of Rosebengal/folicacid-functionalized multiwall carbon nanotubes

A few metal complexes of isatin-isonicotinoylhydrazone with Ni(II), Cr(III), Co(II), Cu(II), Zn(II) and Cd(II) have been prepared and characterized on the basis of elemental analyses, infrared and electronic spectra as well as "1H NMR spectra, conductivity and magnetic measurements. In view of the results obtained, it has been found that two molecules of isatin-isonicotinoylhydrazone are chelated to the central metal ion as bis-uninegative ONO tridentate ligand forming non-electrolytic octahedral metal complexes. (author)

1997-03-01

406

British Library Electronic Table of Contents (United Kingdom)

Multiwall carbon nanotubes (MWCNTs) were functionalized with a photosensitizer, rosebengal (RB), and folicacid (FA), an anti-cancer drug simultaneously and individually, which was characterized with various analytical instruments like Fourier Transform Iinfrared (FTIR) spectroscopy, UV?Vis spectroscopy, Thermogravimetric analysis (TGA), Photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Transmission electron microscopy (TEM). FTIR spectra confirmed the chemical modification of MWCNT. The chemical functionalization of MWCNT with RB was further supported by UV?Vis and PL spectra.

2011-01-01

407

State and prospects of the experimental and stand base for fundamental investigations of the RF Ministry for Atomic Energy

Solution-chemical syntheses of nanostructure HgTe via a simple hydrothermal process

The aim of the report is to describe the state and prospects of the experimental and stand base (ESB) for fundamental investigations in the RF Ministry for Atomic Energy. The ESB includes the following scientific directions: high energy physics, nuclear physics, solid state physics (including superconductivity), plasma physics and controlled thermonuclear synthesis, nuclear reactors and reactor materials testing, lasers, energy conversion and others. Main economical, scientific and technical data on the ESB as a whole and on its most large scientific centers are presented

2003-06-03

408

Solid-state ozone synthesis by energetic ions

HgTe rod-shape composed of crystalline particles has been prepared by a hydrothermal method, and characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM). The effects of capping agents, reductants, reaction temperatures, and reaction times on crystal structures and shapes of HgTe have been investigated. The results showed that the CTAB as capping agent plays a crucial role in the hydrothermal process. The synthesis procedure is simple and uses less toxic reagents than the previously reported methods.

2010-06-04

409

Solid-phase synthesis and pharmacological evaluation of novel nucleoside-tethered dinuclear platinum(II) complexes

We have synthesized ozone by irradiating thin solid films of oxygen and oxygen-water mixtures with 100 keV protons, motivated by recent reports of condensed O_3 on icy satellites in the outer Solar system. We measured the depth of the Hartley absorption band in the ultraviolet by reflectance spectroscopy and used it to quantify the column density of ozone. We analyzed the results using a three-component (O, O_2 and O_3) model that successfully explains the fluence dependence of ozone production.

1999-08-02

410

British Library Electronic Table of Contents (United Kingdom)

Three novel inosine-based dinuclear platinum complexes have been synthesized via a solid-phase strategy. In these compounds, the metal is linked both to the N-7 of the purine nucleus and to the terminal amine group of a hexylamine side chain installed on N-1. Cis- or trans- diamine as well as ethylenediamine ligands are coordinated to platinum along with a chloride. The synthesised complexes were tested against four different human tumor cell lines. One of these complexes proved to be more cytotoxic than cisplatin against the MCF7 cancer cell line in a short-term exposure assay.

2011-01-01

411

Refinement of conventional PSS design in multimachine system by modal analysis

Radioiodinated phenoxyacetic acid derivatives as potential brain imaging agents, 1; Efficient synthesis via trimethylsilyl intermediates

The design of the lead/lag network in a conventional power system stabilizer (PSS) is intended to provide the correct compensation in order to obtain an electrical torque component in phase with the speed variation. It is shown that, for a multimachine system, the conventional design analysis and synthesis tend to oversimplify the system representation and hence the interaction effects. A more rigorous approach is preferred considering four torque (or power) components instead of the conventional single component. Based on modal analysis, the significance of these other components is revealed, the more comprehensive treatment using a generalized multimachine representation is justified and a reliable means for optimizing the PSS parameters is explained.

1993-05-01

412

Radiation induced synthesis of low molecular weight of PTFE and their crosslinking in acetone medium

The usefulness of radioiodination via demetallation of aryltrimethylsilanes was demonstrated. The radioiodination reaction was found to be very rapid and the regiospecific incorporation of radioiodine could be carried out with high radiochemical yields and high radiospecific activity. {sup 125}I-Labeled dimethylaminoethyl iodophenoxyacetate derivatives (5a-e), dimethylaminoethyl iodophenoxyacetamide derivatives (7a-c), iodophenoxyethyl ethylenediamine derivatives (9,14) and an iodophenoxyethylpiperazine derivative (18) were efficiently synthesized from the corresponding aryltrimethylsilyl intermediates (4a-e, 6a-c, 8, 13, 17) by this method. (author).

1989-09-01

413

Process for producing two-carbon atom oxygenated compounds from synthesis gas with minimal production of methane

Polytetrafluoroethylene was obtained by radiation induced polymerization of tetrafluoroethylene in acetone at 195 K. An average diameter of the products was very small compared with commercial one; it was about 0.3 micro-meters. The yield was reached to 100% with a dose of 4 kGy. The crystallinity of the products is decreasing with increasing dose. The products become amorphous, for higher irradiation doses. It was found that PTFE obtained by irradiation of TFE in acetone at 195 K has branching structure. This was demonstrated by means of "1"9F MAS NMR. (Author)

2007-09-03

414

Preparation of NiZn-ferrite nanofibers by electrospinning for DNA separation

A process is claimed for selectively preparing a mixture of two-carbon atom oxygenated hydrocarbons, namely, acetic acid, ethanol and acetaldehyde, by continuously contacting a gaseous reaction mixture containing hydrogen and carbon monoxide with a solid catalyst comprising rhodium in combination with one or more alkali metals selected from the group consisting of lithium, potassium, cesium and rubidium at reaction conditions correlated so as to favor the formation of a substantial proportion of such two-carbon atom products.

1980-11-25

415

Preparation of 17-amino-22-(4'-azido-3'-"1"2"5iodophenacyl)-17-demethoxygeldanamycin (1): an ansamycin for photoaffinity labeling

We present the synthesis, magnetic and UV spectrometry of NiZn-ferrite nanofiber. The single phase of spinel ferrite was obtained at 600 {sup o}C. The NiZn-ferrite fibers fabricated by an electrospinning process were formed as a polygonal grain growth with firing temperature in fiber matrix. It appeared that the saturation magnetization (M{sub S}) of NiZn-ferrite nanofiber was dependent on Ni/Zn molar ratio which is similar to that of the inverse spinel ferrites. The NiZn-ferrite fibers showed good DNA adsorption efficiency that can be modified and utilized for DNA separation with magnetic nanofiber as a novel material in clinical applications.

2009-05-15

416

Preparation of 17-amino-22-(4'-azido-3'-[sup 125]iodophenacyl)-17-demethoxygeldanamycin (1): an ansamycin for photoaffinity labeling

An azido-"1"2"5iodo-ansamycin (1) in the geldanamycin family was prepared in two steps in one reaction vessel from 17-amino-22-(4'-aminophenacyl)-17-demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. An alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies. (Author).

417

Perovskite-type SrTi1-xNbx(O,N)3 compounds: Synthesis, crystal structure and optical properties

An azido-[sup 125]iodo-ansamycin (1) in the geldanamycin family was prepared in two steps in one reaction vessel from 17-amino-22-(4'-aminophenacyl)-17-demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. An alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies. (Author).

1994-06-01

418

On the influence of silicon oxide nanoparticles on the optical and surface properties of hybrid (inorganic-organic) barrier materials

The synthesis, crystal structure, thermal stability and absorbance spectra of perovskite-type oxynitrides with the general formula SrTi1-xNbx(O,N)3 (x=0.05, 0.10, 0.20, 0.50, 0.80, 0.90, 0.95) have been investigated. Oxide samples were prepared by a polymerized complex synthesis route and post-treated under ammonia at 850 oC for 24 h to substitute nitrogen for oxygen. Synchrotron X-ray powder diffraction (XRD) evidenced that the mixed oxide phases were all transformed into oxynitrides with perovskite-type structure during a thermal ammonolysis. SrTi1-xNbx(O,N)3 with compositions x?0.80 crystallized in a cubic and samples with x?0.90 in a tetragonal structure. The Rietveld refinement indicated a continuous enlargement of the lattice parameters towards higher niobium content of the samples. Thermogravimetric analysis (TGA) and hotgas extraction revealed the dependence of the nitrogen incorporation upon the degree of niobium substitution. It ...

2011-04-01

419

More Polish coal mines needed

One of the major scientific and technological challenges for the production of flexible organic electronic devices is the device protection against atmospheric molecule permeation, which causes corrosion reducing its operation and lifetime. In this work, Spectroscopic Ellipsometry has been implemented to investigate the influence of silicon dioxide nanoparticles on the optical properties of hybrid polymers. The spectra analysis revealed valuable information about the electronic and vibrational response as well as the cross-linking mechanisms of these materials. The correlation of the optical properties with the synthesis parameters and the barrier response will contribute towards their optimization in order to be used as high barrier coatings for flexible organic electronics applications.

2009-10-01

420

Medical and pharmaceutical applications of polymers: A review paper

The economy of Poland depends to a large extent upon the exploitation of its vast rich coal reserves for which new mines will have to be sunk and existing mines modernized. Two avenues of coal conversion are being followed. Both involve hydrogenation but one is based on solvent extraction of coal and the other on its pyrolysis. At present large scale established methods of chemical treatment are those which involve the production of coke, production of town-gas, production of synthesis gas and partial oxydation. Total weight amounts to 21,000,000 tons.

1977-11-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

421

LYCOS: The Lyngby Co-Synthesis System

This review begins with an historical account of biomaterials applications followed by a concise description of the phenomena taking place between the living tissues and non-living materials containing them. After describing the requirements for biodegradability and the mechanisms involved, a thorough literature survey of such polymers is presented. In the end a very short review of the work done in this area by the authors in recent years is given, including: the synthesis of a wide variety of biodegradable di-and tri-block copolymers, preparation of microparticles; stealth-and immuno-liposomes; dendrosomes and polymersomes; and some of their applications in drug and gene delivery.

422

Ionizing Radiation and Life

This paper describes the LYCOS system, an experimental co-synthes is environment. We present the motivation and philosophy of LYCOS and after an overview of the entire system, the individual parts are described. We use a single CPU, single ASIC target architecture and we describe the techniques we use to estimate metrics concerning hardware, software and communication in this architecture. Finally we present a novel partitioning technique called PACE, which has shown to produce excellent results, and we demonstrate how partitioning is used to do design space exploration.

1997-01-01

423

British Library Electronic Table of Contents (United Kingdom)

Abstract Ionizing radiation is a ubiquitous feature of the Cosmos, from exogenous cosmic rays (CR) to the intrinsic mineral radioactivity of a habitable world, and its influences on the emergence and persistence of life are wide-ranging and profound. Much attention has already been focused on the deleterious effects of ionizing radiation on organisms and the complex molecules of life, but ionizing radiation also performs many crucial functions in the generation of habitable planetary environments and the origins of life. This review surveys the role of CR and mineral radioactivity in star formation, generation of biogenic elements, and the synthesis of organic molecules and driving of prebiotic chemistry. Another major theme is the multiple layers of shielding of planetary surfaces from th...

2011-01-01

424

Influence of the reductive preparation conditions on the morphology and on the electrochemical performance of Sn/SnSb

Influence of chromatin molecular changes on RNA synthesis during embryonic development

Lithium storage metals and alloys can be suitable high-capacity anode materials for lithium-ion batteries, when the morphology is specifically designed. Here, we compare three different Sn/SnSb multiphase anode materials in powder form, which have been prepared in aqueous and organic solution by chemical precipitation using NaBH{sub 4} or Zn as reductive agents. The obtained morphologies, chemical compositions, and the electrochemical performance will be comparatively discussed. The variety of synthesis parameters which have an effect on the morphology of the obtained anode materials will be particularly highlighted.

2004-03-15

425

High octane ethers from synthesis gas-derived alcohols

Two aspects of the chromatin repeat length (r_l) are discussed: (i) Why is r_l longer for slowly dividing cells than in rapidly dividing cells?, and (ii) Why is the temporal evolution of r_l a decreasing function of time (t) in mammalian cortical neurons whereas it is an increasing function of t for granule cells around the time of birth? These questions are discussed in terms of a hypothesis which assumes a correlation between deoxyribonucleic acid (DNA) packaging, transcription, and replication. (author). 27 refs.

426

Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were proposed

Catalytic testing of inorganic catalysts was continued with the highly active sulfate-modified zirconia catalyst prepared here. Using isobutanol as the only reactant over this catalyst, it was demonstrated that high conversion and selectivity to isobutene was achieved at 175[degrees]C. In addition, the high selectivity to isobutene, i.e. 79--86 mol%, was maintained at higher space velocities and higher temperatures. A high productivity of 11.35 mol isobutene was achieved at 225[degrees]C. Utilizing a methanol/isobutanol = 2/1 molar ratio reactant mixture over the ZrO[sub 2]/SO[sub 4][sup 2[minus

1992-10-01

427

British Library Electronic Table of Contents (United Kingdom)

Objective: Results of reliability and agreement studies are intended to provide information about the amount of error inherent in any diagnosis, score, or measurement. The level of reliability and agreement among users of scales, instruments, or classifications is widely unknown. Therefore, there is a need for rigorously conducted interrater and intrarater reliability and agreement studies. Information about sample selection, study design, and statistical analysis is often incomplete. Because of inadequate reporting, interpretation and synthesis of study results are often difficult. Widely accepted criteria, standards, or guidelines for reporting reliability and agreement in the health care and medical field are lacking. The objective was to develop guidelines for reporting reliability and...

2011-01-01

428

Explosives synthesis at Los Alamos

Evaluation of wastewater treatment requirements for thermochemical biomass liquefaction

During the past two decades, the explosives synthetic effort at Los Alamos has been directed toward energetic heterocylic compounds and has produced some useful thermally stable explosives. The recent evolution of crystal-density predictive methods is guiding our current efforts toward ultrahigh performance explosives. Much of our effort is now on the development of new methods for preparing unique nitro compounds that are inaccessible by conventional techniques. This paper reviews the Los Alamos synthetic program with emphasis on the development of novel thermally stable explosives, and current efforts to synthesize high-density/performance explosives will be discussed.

1986-03-01

429

Enzymatic synthesis of N- and O-linked glycopeptides

Biomass can provide a substantial energy source. Liquids are preferred for use as transportation fuels because of their high energy density and handling ease and safety. Liquid fuel production from biomass can be accomplished by any of several different processes including hydrolysis and fermentation of the carbohydrates to alcohol fuels, thermal gasification and synthesis of alcohol or hydrocarbon fuels, direct extraction of biologically produced hydrocarbons such as seed oils or algae lipids, or direct thermochemical conversion of the biomass to liquids and catalytic upgrading to hydrocarbon fuels. This report discusses direct thermochemical conversion to achieve biomass liquefaction and the requirements for wastewater treatment inherent in such processing. 21 refs.

1992-04-01

430

Environmental sciences and applications. Volume 4. Strategy for the ozone layer

This paper describes the study of kinetically controlled enzymatic coupling of N- and O-glycopeptide fragments using subtilisin BPN' and two of its variants developed for use in high concentrations of dimethylformamide and in aqueous solution, respectively. Glycosyl amino acids were exploited as the P[sub 1], P[sub 2], P[sub 3], P'[sub 1], P'[sub 2], or P'[sub 3] residue in the enzymatic coupling. Glycosyltransferase-mediated glycosylation of the glycopeptide fragments obtained prior to or after enzymatic peptide bond formation is demonstrated. 19 refs., 5 figs., 1 tab.

1993-07-14

431

Effect of lead nitrate on thyroid function on the Indian palm squirrel, Funambulus pennanti (Wroughton)

A synthesis of papers based on the United Nations Environment Programme meeting on the ozone layer, Washington DC, this book contains valuable information on ongoing and planned activities concerned with stratospheric ozone problems, and presents the recommendations for further action resulting from the meeting. Possible changes in the characteristics of the ozone layer are discussed, together with the environmental, ecological, climatic, economic, and health implications of stratospheric ozone depletion. A comprehensive survey of current research in five European countries, the USA, Canada, and Australia is included and the volume is concluded by the UNEP report of the meeting and a world plan of action.

1980-01-01

432

Double-lock ratchet mechanism revealing the role of ?SER-344 in F_oF₁ ATP synthase

Some of the known toxic effects of lead in mammals including man are, impaired heme synthesis, anemia, nepatopathy, nephropathy, behavioral disorders and neuropathy. However, very little is known about the effect of lead on endocrine physiology. Some data are available on lead induced impairment of thyroid function in occupationally exposed men and experimental rats. As lead nitrate is largely consumed through water and food, in this study the wild rodents Funambulus pennanti were administered lead through their drinking water and their thyroid structure, radioiodine 131-I percentage uptake and protein bound iodine (PBI) level were assessed.

1987-06-01

433

Design, synthesis and evaluation of redox radiopharmaceuticals: a potential new approach for the development of brain imaging agents

In a majority of living organisms, F_oF₁ ATP synthase performs the fundamental process of ATP synthesis. Despite the simple net reaction formula, ADP + P_i → ATP + H₂O,...Full Text Available

2011-03-22

434

Design of a Fractional Order PID Controller Using Particle Swarm Optimization Technique

The goals of this paper are to describe the fabrication and complete evaluation of a dihydropyridine <- -> pyridinium salt type redox system for the delivery of radioiodinated agents to the brain. Tissue distribution studies of "1"2"5I-labeled 4-iodoaniline and the redox agents were performed in rats. ["1"2"5I]Iodoaniline initially showed moderate brain uptake with subsequent release of the radioactivity from the brain. ["1"2"5I]Iodoaniline, however, when coupled to a dihydropyridine carrier showed significantly higher uptake and retention in the brain. (author).

435

Crystal chemistry of hydroxyl and water in silicate minerals. Final technical report

Particle Swarm Optimization technique offers optimal or suboptimal solution to multidimensional rough objective functions. In this paper, this optimization technique is used for designing fractional order PID controllers that give better performance than their integer order counterparts. Controller synthesis is based on required peak overshoot and rise time specifications. The characteristic equation is minimized to obtain an optimum set of controller parameters. Results show that this design method can effectively tune the parameters of the fractional order controller.

2008-01-01

436

Coordination lanthanide compounds with thiosemicarbazide diacetic acid

This was a project to investigate the crystal chemistry of OH and H{sub 2}O substitution in silicate minerals by use of X-ray and neutron diffraction methods combined with IR spectroscopy and to interpret and generalize the results using an electrostatic model for these mineral structures. Using these data together with published H position data electrostatic parameters for H sites were calculated from a simple electrostatic model. The data were then used to refine the model for incorporation of H into the wadsleyite structure. This has led to recent work on the synthesis and characterization of hydrous wadsleyites.

1998-06-01

437

Coordination lanthanide compounds with thiosemicarbazide diacetic acid

A study was made on complex formation of thiosemicarbazide diacetic acid (H/sub 2/L) with neodymium (3), holmium (3) and erbium (3) in solutions and formation of complexes of metal: ligand=4:1 composition was revealed. Synthesis conditions were developed and products of LnLClxnH/sub 2/O, LnLOHxnH/sub 2/O, Na(LnL/sub 2/)xnH/sub 2/O composition were separated in crystalline state. It was shown, that H/sub 2/L behaves in these compounds as tripod ligand with O, O, N, N donor atoms.

1983-02-01

438

Biodegradation in oils as a geological natural analogue

A study was made on complex formation of thiosemicarbazide diacetic acid (H_2L) with neodymium (3), holmium (3) and erbium (3) in solutions and formation of complexes of metal: ligand=4:1 composition was revealed. Synthesis conditions were developed and products of LnLClxnH_2O, LnLOHxnH_2O, Na[LnL_2]xnH_2O composition were separated in crystalline state. It was shown, that H_2L behaves in these compounds as tripod ligand with O, O, N, N donor atoms.

439

A one-pot radiosynthesis of ["1"2"5I]iodoazido photoaffinity labels

A synthesis of scientific knowledge about petroleum biodegradation linked to uranium mineralisation is firstly done. Then the genesis of Huemul Uranium ore deposit (Malargue Town, Mendoza Province) is discussed, where Uranium ore is linked only with one type of asphaltite (there are three other types) from an oil field close by. This asphaltite type would be an efficient natural geological barrier for Uranium migration and it could be linked to a particular kind of biodegradation. The authors think that the International Wonuc Conference would be a good opportunity to discuss a way for future investigations. (author)

440

A one-pot radiosynthesis of ( sup 125 I)iodoazido photoaffinity labels

A useful method for preparing radioiodinated photoaffinity labels from alkyl anilines which offer significant advantages over present methods is described. The one-pot synthesis gives good radiochemical yields (40-64%) of pure, high specific activity (350-1500 mCi/#mu#mol) "1"2"4I labelled iodaryl azides while minimising manipulation of radioactive materials. Purification of the ["1"2"5I]iodoazido photoaffinity labels is achieved by high performance liquid chromatography. (author).

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

441

A high capacity, template-electroplated Ni-Sn intermetallic electrode for lithium ion battery

A useful method for preparing radioiodinated photoaffinity labels from alkyl anilines which offer significant advantages over present methods is described. The one-pot synthesis gives good radiochemical yields (40-64%) of pure, high specific activity (350-1500 mCi/{mu}mol) {sup 124}I labelled iodaryl azides while minimising manipulation of radioactive materials. Purification of the ({sup 125}I)iodoazido photoaffinity labels is achieved by high performance liquid chromatography. (author).

1989-11-01

442

British Library Electronic Table of Contents (United Kingdom)

In this paper we describe a Ni-Sn intermetallic material obtained via template electroplating synthesis. The structure and the morphology of this material are investigated by X ray diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. We demonstrate that Ni-Sn behaves as a sub-micrometric electrode showing a favourable response when cycled in a lithium cell. The results here reported suggest that the template electroplating is a promising synthetic approach that can lead to an optimized structure and morphology of the Ni-Sn electrode, such as to confer it a role of a high capacity anode in advanced lithium ion batteries.

2011-01-01

443

(Pittsburgh Energy Technology Center): Quarterly technical progress report for the period ending June 30, 1987. [Advanced Coal Research and Technology Development Programs

Synthesis of model compounds for coal liquefaction research. Final report, April 15, 1990--April 14, 1991

Research programs on coal and coal liquefaction are presented. Topics discussed are: coal science, combustion, kinetics, surface science; advanced technology projects in liquefaction; two stage liquefaction and direct liquefaction; catalysts of liquefaction; Fischer-Tropsch synthesis and thermodynamics; alternative fuels utilization; coal preparation; biodegradation; advanced combustion technology; flue gas cleanup; environmental coordination, and technology transfer. Individual projects are processed separately for the data base. (CBS)

1988-02-01

444

Synthesis of model compounds for coal liquefaction research

Coal liquefaction investigations required the availability of model compounds for mechanistic investigations. Towards this end, IITRI was funded to develop an approach for the synthesis of one of the target compound. This study was carried out in several phases as outlined here. Initial synthetic investigations on obtaining 2-tetrolol was carried out using high pressure and temperature reduction with Raney nickel catalyst. The next step consisted in incorporation of a hydroxymethyelene group at the C-3 position. This was successfully carried out utilizing 2-tetrolol, formaldehyde, and calcium oxide. An alternate improved method was developed using 3-carboxyl-2-naphthol. This required less time, gave a cheer product in higher yield. Efforts at the introduction of a chloromethylene group only yielded polymeric material or starting material in spite of protection the phenolic group by various groups. They synthesis of 3, 5-dimethyl-6- bromobenzyl ...

1991-11-01

445

Solid-state NMR and XRD study of #alpha#-SiAlON powders prepared by combustion synthesis

Coal liquefaction investigations required the availability of model compounds for mechanistic investigations. Towards this end, IITRI was funded to develop an approach for the synthesis of one of the target compound. This study was carried out in several phases as outlined here. Initial synthetic investigations on obtaining 2-tetrolol was carried out using high pressure and temperature reduction with Raney nickel catalyst. The next step consisted in incorporation of a hydroxymethyelene group at the C-3 position. This was successfully carried out utilizing 2-tetrolol, formaldehyde, and calcium oxide. An alternate improved method was developed using 3-carboxyl-2-naphthol. This required less time, gave a cheer product in higher yield. Efforts at the introduction of a chloromethylene group only yielded polymeric material or starting material in spite of protection the phenolic group by various groups. They synthesis of 3, 5-dimethyl-6- bromobenzyl ...

1991-11-01

446

Research progress in high voltage spinel LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} material

"2"7Al and "2"9Si solid-state NMR spectra and X-ray diffraction (XRD) patterns were obtained for #alpha#-SiAlON powders prepared by combustion synthesis, according to which the phase transformation and structure evolution of #alpha#-SiAlON were studied. It was found that in #alpha#-SiAlON "2"9Si chemical shift values (-48 < #delta# _S_i < -47) were close to those in #beta#-Si_3N_4 and #alpha#-Si_3N_4, indicating that Si atoms kept SiN_4 coordination to a large extent in #alpha#-SiAlON despite the presence of O atoms. Dissimilarly, "2"7Al chemical shift values in #alpha#-SiAlON deviated clearly from that corresponding to AlN_4 coordination (#delta# _A_l #approx# 112) and occurred in a range from #delta# _A_l 95.5 to 99.9, which should be assigned to tetrahedral AlO _xN_4_-_x (0 #<=# x #<=# 4) coordination. The broadening effect of AlO _xN_4_-_x peaks was noticed, which was suggested to induced by slight dispersion of #alpha#-SiAlON compositions. "2"7Al ...

2007-07-31

447

Research progress in high voltage spinel LiNi0.5Mn1.5O4 material

Lithium-ion batteries are now considered to be the technology of choice for future hybrid electric and full electric vehicles to address global warming. LiCoO{sub 2} has been the most widely used cathode material in commercial lithium-ion batteries. Since LiCoO{sub 2} has economic and environmental issues, intensive research has been directed towards the development of alternative low cost, environmentally friendly cathode materials as possible replacement of LiCoO{sub 2}. Among them, spinel LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} material is one of the promising and attractive cathode materials for next generation lithium-ion batteries because of its high voltage (4.7 V), acceptable stability, and good cycling performance. Research advances in high voltage spinel LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} are reviewed in this paper. Developments in synthesis, structural characterization, effect of doping, and effect of coating are presented. In addition to conventional ...

2010-09-01

448

Prostaglandin (PG) E3 synthesis elicted by adrenergic stimuli in guinea-pig trachea (GPT) is mediated primarily by B2 adrenergic receptors

Lithium-ion batteries are now considered to be the technology of choice for future hybrid electric and full electric vehicles to address global warming. LiCoO2 has been the most widely used cathode material in commercial lithium-ion batteries. Since LiCoO2 has economic and environmental issues, intensive research has been directed towards the development of alternative low cost, environmentally friendly cathode materials as possible replacement of LiCoO2. Among them, spinel LiNi0.5Mn1.5O4 material is one of the promising and attractive cathode materials for next generation lithium-ion batteries because of its high voltage (4.7 V), acceptable stability, and good cycling performance. Research advances in high voltage spinel LiNi0.5Mn1.5O4 are reviewed in this paper. Developments in synthesis, structural characterization, effect of doping, and effect of coating are presented. In addition to conventional synthesis methods, several alternative ...

2010-09-01

449

Prostaglandin (PG) E3 synthesis elicted by adrenergic stimuli in guinea-pig trachea (GPT) is mediated primarily by B2 adrenergic receptors

The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ({sup 14}C)AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ({sup 14}C)AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2{alpha}. Trace amounts of PGD2 and 6-keto-PGF1{alpha} but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10{sup {minus}7}, 10{sup {minus}7}M respectively). In contrast, dobutamine, norepinephrine, ...

1990-02-26

450

Preliminary study on zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction

The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ["1"4C]AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ["1"4C]AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2#alpha#. Trace amounts of PGD2 and 6-keto-PGF1#alpha# but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10"-"7, 10"-"7M respectively). In contrast, dobutamine, norepinephrine, phenylnephrine and xylazine (up to 10"-"6M) did not ...

1991-04-21

451

Insulin regulation of protein biosynthesis in differentiated 3T3 adipocytes. Regulation of glyceraldehyde-3-phosphate dehydrogenase

A zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction is reported in this paper. It possesses functions of both zincate reduction and electrochemical preparation, showing the potential for increasing the electronic energy utilization. Charge/discharge tests and scanning electron microscopy (SEM) micrographs reveal that when a nickel sheet plated with the high-H{sub 2}-overpotential metal, cadmium, was used as the negative substrate electrode, the dendritic formation and hydrogen evolution are suppressed effectively, and granular zinc deposits become larger but relatively dense with the increase of charge time. The performance of batteries is favorable even if the charge time is as long as 5 h at the current density of 20 mA cm{sup -2}. Better discharge performance is achieved using a 'cavity-opening' configuration for the discharge cell rather than a 'gas-introducing' configuration. The ...

2009-03-01

452

Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system

The effect of insulin on protein biosynthesis was examined in differentiated 3T3-L1 and 3T3-F442A adipocytes. Insulin altered the relative rate of synthesis of specific proteins independent of its ability to hasten conversion of the fibroblast (preadipocyte) phenotype to the adipocyte phenotype. Although more than one pattern of response to insulin was observed, the authors focused on the induction of a Mr 33,000 protein which was identified as the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Exposure of 3T3 adipocytes to insulin throughout differentiation specifically increased GAPDH activity and protein content by 2- to 3-fold as compared to 3T3 adipocytes differentiated in the absence of insulin. These changes in enzyme activity and content could be accounted for by a 4-fold increase in the relative rate of synthesis of GAPDH and a 9-fold increase in hybridizable mRNA levels. Within 2 h of insulin addition to 3T3 ...

1985-10-05

453

Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of /sup 203/Pb and /sup 47/Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol (1,25(OH)/sub 2/D/sub 3/) as their only source of the vitamin, the absorption of both /sup 47/Ca and /sup 203/Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in /sup 47/Ca and /sup 203/Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with 1,25(OH)/sub ...

1984-04-01

454

Comparative investigation on chemical looping combustion of coal-derived synthesis gas containing H2S over supported NiO oxygen carriers

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of "2"0"3Pb and "4"7Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol [1,25(OH)_2D_3] as their only source of the vitamin, the absorption of both "4"7Ca and "2"0"3Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in "4"7Ca and "2"0"3Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with 1,25(OH)_2D_3, the intestinal absorption of ...

455

(/sup 14/C)sucrose uptake and labeling of starch in developing grains of normal segl barley

Chemical looping combustion (CLC) of simulated coal-derived synthesis gas was conducted with NiO oxygen carriers supported on SiO2, ZrO2, TiO2, and sepiolite. The effect of H2S on the performance of these samples for the CLC process was also evaluated. Five-cycle thermogravimetric analysis (TGA) tests at 800 C indicated that all oxygen carriers had a stable performance at 800 C, except NiO/SiO2. Full reduction/oxidation reactions of the oxygen carrier were obtained during the five-cycle test. It was found that support had a significant effect on reaction performance of NiO both in reduction and oxidation rates. The reduction reaction was significantly faster than the oxidation reaction for all oxygen carriers, while the oxidation reaction is fairly slow due to oxygen diffusion on NiO layers. The reaction profile was greatly affected by the presence of H2S, but there was no effect on the capacity due to the presence of H2S in synthesis gas. The ...

2010-01-01

456

The role of surfactant in synthesis of magnetic nanocrystalline powder of NiFe2O4 by sol-gel auto-combustion method

Previous work showed that the segl mutant of barley (Hordeum vulgare o Betzes) did not differ from normal Betzes in plant growth, photosynthesis, or fertility, but it produced only shrunken seeds regardless of pollen source. To determine whether defects in sucrose uptake or starch synthesis resulted in the shrunken condition, developing grains of Betzes and segl were cultured in (/sup 14/C)sucrose solutions after slicing transversely to expose the endosperm cavity and free space. In both young grains (before genotypes differed in dry weight) and older grains (17 days after anthesis, when segl grains were smaller than Betzes), sucrose uptake and starch synthesis were similar in both genotypes on a dry weight basis. To determine if sucrose was hydrolyzed during uptake, spikes of Betzes and segl were allowed to take up (fructose-U-/sup 14/C)sucrose 14 days after anthesis and the radioactivity of endosperm sugars was examined during 3 hours of ...

1984-01-01

457

British Library Electronic Table of Contents (United Kingdom)

In this work, a new sol-gel auto-combustion method has been performed to synthesize single phase nickel ferrite nanocrystalline powders by using n-cetyltrimethylammonium bromide, as a cationic surfactant. The gels were prepared from ferric and nickel nitrates and citric acid. Ammonia was used as pH adjusting agent as well. The effects of the surfactant on the after combustion calcination process and the reduction of the resulting powder crystallite size which affects the magnetic properties of the material were investigated by XRD and DTA/TGA techniques. The results showed that the ignition of the gels in air have a self-propagating behavior. Addition of surfactant to the starting solution affected the crystallite size of the synthesized powders and their phase constitution. The crystallit...

2008-01-01

458

The effect of thermally pulsating asymptotic giant branch stars on the evolution of the rest-frame near-infrared galaxy luminosity function

British Library Electronic Table of Contents (United Kingdom)

Abstract We address the fundamental question of matching the rest-frame K-band luminosity function (LF) of galaxies over the Hubble time using semi-analytic models after modification of the stellar population modelling. We include the Maraston evolutionary synthesis models, which feature a higher contribution by the thermally pulsating asymptotic giant branch (TP-AGB) stellar phase, into three different semi-analytic models, namely the De Lucia and Blaizot version of the Munich model, morgana and the Menci model. We leave all other input physics and parameters unchanged. We find that the modification of the stellar population emission can solve the mismatch between models and the observed rest-frame K-band luminosity from the brightest galaxies derived from UKIRT Infrared Deep Sky Survey d...

2011-01-01

459

Tetrazine explosives

Synthesis, crystal structure, spectroscopic properties, antibacterial activity and theoretical studies of a novel difunctional acylhydrazone

The synthesis and properties of various 1,2,4,5-tetrazine explosives and energetic materials are described. These are the nitrate and perchlorate salts of 3,6-diguanidino-1,2,4,5-tetrazine, the nitrate and perchlorate salts of 3,6-diguanidino-1,2,4,5-tetrazine-1,4-di-N-oxide, 3,6-bis(1H-1,2,3,4-tetrazol-5-ylamino)-1,2,4,5-tetrazine and its 1,4-di-N-oxide derivative, 3,3'-azobis(6-amino-1,2,4,5-tetrazine) and its oxidation products. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

2004-08-01

460

British Library Electronic Table of Contents (United Kingdom)

A novel difunctional acylhydrazone has been synthesized by the reaction of 5-methylisoxazole-4-carboyl hydrazine with benzaldehyde and characterized by X-ray crystallography and spectroscopy. The obtained results demonstrate the crystal belongs to triclinic, space group Formula Not Shown . Moreover, the spectroscopic properties were evaluated through density functional theory (DFT) and time-dependent density functional theory (TD DFT) calculations. The results reveal that UV-Vis absorption peaks at 194, 217.5 and 290.5nm are mainly attributed to (p, p)p*, partly (p, p)p* and partly pp*, and predominantly pp*, respectively, with intraligand charge-transfer transition (ILCT) character. The fluorescence emission peak at 485.96nm should be assigned to ILCT. In addition, the results of antibact...

2011-01-01

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461

Synthesis of monohydric alcohols from CO and H2 on Fe/Sibunit catalysts

British Library Electronic Table of Contents (United Kingdom)

It was demonstrated that R 2?R 4 saturated monohydric alcohols can be synthesized from CO and H2 in the presence of Fe catalysts containing a carbon support of the Sibunit type with granule sizes of 3?5, 1?2, and 0.05?0.1 mm in a fixed-bed reactor at 3 MPa and 240?300?C. It was found that the activity of Fe/Sibunit catalysts and their selectivity for the formation of liquid synthetic products increased with the size of granules and the amount of iron. The catalysts make it possible to obtain fatty alcohols, in which the fraction of R 2?R 4 alcohols is as high as 75%, in yields to 56 g/m3.

2011-01-01

462

Synthesis of metallic nanoparticles in SiO{sub 2} matrices; Sintesis de nanoparticulas metalicas en matrices de SiO{sub 2}

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method

Metallic nanoparticles was synthesized in SiO{sub 2} matrices by means of a process of two stages. The first one proceeded via sol-gel, incorporating the metallic precursors to the reaction system before the solidification of the matrix. Later on, the samples underwent a thermal treatment in atmosphere of H{sub 2}, carrying out the reduction of the metals that finally formed to the nanoparticles. Then it was detected the presence of smaller nanoparticles than 20 nm, dispersed and with the property of being liberated easily of the matrix, conserving a free surface, chemically reactive and with response to external electromagnetic radiation. The system SiO{sub 2}-Pd showed an important thermoluminescent response. (Author)

2004-07-01

463

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe{sup 3+} and Fe{sup 2+}) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-15

464

Synthesis and tissue distribution study of iodine-labeled benzyl- and xylylamines

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe"3"+ and Fe"2"+) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-01

465

Synthesis and enhanced light absorption of alumina matrix nanocomposites containing multilayer oxide nanorods and silver nanoparticles

Four "1"2"5I labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogues of the previously reported "7"5Se labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after intravenous injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 approximately 18 h), which is desirable for brain imaging. In contrast, the benzylamine is rapidly cleared from brain tissue (t1/2 approximately 15 min).

466

British Library Electronic Table of Contents (United Kingdom)

In this paper, multilayer oxide nanorods were deposited in the nanopores of anodic aluminum oxide (AAO) via solution infiltration followed by heat treatment. The nanorods have a core-shell structure. First, the shell (nanotube) with the thickness of about 40nm was made of TiO"2 through the hydrolysis of (NH"4)"2TiF"6. Second, silver nanoparticles with the diameter of about 3nm were added into the TiO"2 layer through thermal decomposition of AgNO"3 at elevated temperatures. Then, cylindrical cores (nanorods) of CoO and ZnO with 200nm diameter were prepared, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and composition of the nanorods. UV-vis light absorption measurements in the wavelength range from 350 to...

2011-01-01

467

Synthesis and electrochemical properties of lithium ion conductive glass, Li[sub 3]PO[sub 4]-Li[sub 2]S-SiS[sub 2

Synthesis and characterization of myristic acid capped silver nanoparticles

As a continuation of our previous study, further experiments were performed on Li[sub 3]PO[sub 4]-Li[sub 2]S-SiS[sub 2] lithium ion conductive glass. In the present study, we employed a twin roller for quenching process instead of liquid nitrogen. We found that the glass forming region expands by twin roller technique and conductivity up to 1.5x10[sup -3] S/cm was achieved. Structural analysis on the glass revealed that Li[sub 3]PO[sub 4] doping changes the glass structure of Li[sub 2]S-SiS[sub 2], thereby enhancing the electrical conductivity

1994-02-01

468

Synthesis and characterization of Co-Ag core-shell nanoparticles

Reduction of silver myristate (AgMy) under mild thermal reaction conditions in a dipolar aprotic solvent i.e. N, N-dimethylformamide (DMF) has been carried out. UV-visible absorption measurements of dried and re-dispersible brown flocculants showed broad features of surface plasmon resonance (SPR) due to silver nanoparticles. The freshly isolated particles showed absorption bands at 414 and 485 nm, respectively, due to inter-particle coupling or clustering of silver ions and silver atoms. X-ray diffraction (XRD) pattern of fcc zero-valent silver resulted in crystallite size of about 10 nm. Scanning electron microscopy (SEM) revealed formation of rod shaped silver with increasing reaction temperature. Thermal analysis (TGA) showed about 10% weight loss due to organic capping.

2008-08-15

469

Sterically stabilized water based magnetic fluids: Synthesis, structure and properties

A micellar method has been used to prepare silver-coated cobalt (Co-Ag) nanoparticles. The synthesized particles have been deeply characterized by several methods, i.e., XRD, UV-Vis, TEM, XPS, and electrochemical techniques. There is every indication that the obtained particles show a truly core-shell structure. All the nanoparticles obtained under different conditions are in the size range 3-5 nm. High-resolution TEM (HRTEM), Fast Fourier Transformation (FFT), and Selected Area Electron Diffraction (SAED) indicated that the presence of hcp-Co and fcc-Ag, in which cobalt is located in the central area; meanwhile silver is at the edges of the nanoparticle. The absorption band of the Co-Ag colloid shifts to a longer wavelength and broadens relative to that of pure silver colloid. Voltammetric characterization allowed to determine the coverage of the cobalt core.

2010-08-15

470

Silica Polyamine Composites: New Supramolecular Materials for Cation and Anion Recovery and Remediation

Magnetic fluids (MFs), prepared by chemical co-precipitation followed by double layer steric and electrostatic (combined) stabilization of magnetite nanoparticles dispersed in water, are presented. Several combinations of surfactants with different chain lengths (lauric acid (LA), myristic acid (MA), oleic acid (OA) and dodecyl-benzene-sulphonic acid (DBS)) were used, such as LA+LA, MA+MA, LA+DBS, MA+DBS, OA+DBS, OA+OA and DBS+DBS. Static light scattering, transmission electron microscopy, small angle neutron scattering, magnetic and magneto-rheological measurements revealed that MFs with MA+MA or LA+LA biocompatible double layer covered magnetite nanoparticles are the most stable colloidal systems among the investigated samples, and thus suitable for biomedical applications.

2007-04-15

471

British Library Electronic Table of Contents (United Kingdom)

Summary: The surface coverage of amorphous silica gels used in the synthesis of silica polyamine composites has been investigated by 29Si NMR. By diluting the polyamine anchor silane, chloropropyl trichlorosilane, with methyl trichlorosilane it was found that surface coverage could be markedly improved for a range of amine polymers after grafting to the silica surface. The commensurate decrease in the number of anchor points and increase in the number of free amines results in an increase in metal capacity and/or an improvement in capture kinetics. Solid state CPMAS-13C NMR has been employed to investigate the structure and metal ion binding of a series of these composite materials. It is reported that the highly branched polymer, poly(ethyleneimine) (PEI) exhibits much broader 13C NMR res...

2006-01-01

472

Selegiline-functionalized, PEGylated poly(alkyl cyanoacrylate) nanoparticles: Investigation of interaction with amyloid-b peptide and surface reorganization

British Library Electronic Table of Contents (United Kingdom)

Alzheimer's disease (AD) is a neurodegenerative disorder for which the research of new treatments is highly challenging. Since the fibrillogenesis of amyloid-b peptide 1-42 (Ab1-42) peptide is considered as a major cause of neuronal degeneration, specific interest has been focused on aromatic molecules for targeting this peptide. In this paper, the synthesis of selegiline-functionalized and fluorescent poly(alkyl cyanoacrylate) nanoparticles (NPs) and their evaluation for the targeting of the Ab1-42 peptide are reported. The synthetic strategy relied on the design of amphiphilic copolymers by tandem Knoevenagel-Michael addition of cyanoacetate derivatives, followed by their self-assembly in aqueous solutions to give the corresponding NPs. Different cyanoacetates were used: (i) hexadecyl cy...

2011-01-01

473

Rapamycin (sirolimus) protects against hypoxic damage in primary heart cultures via Na^+/Ca^2^+ exchanger activation

British Library Electronic Table of Contents (United Kingdom)

Aims: Rapamycin (sirolimus) is an antibiotic that inhibits protein synthesis through mammalian targeting of rapamycin (mTOR) signaling, and is used as an immunosuppressant in the treatment of organ rejection in transplant recipients. Rapamycin confers preconditioning-like protection against ischemic-reperfusion injury in isolated mouse heart cultures. Our aim was to further define the role of rapamycin in intracellular Ca^2^+ homeostasis and to investigate the mechanism by which rapamycin protects cardiomyocytes from hypoxic damage. Main methods: We demonstrate here that rapamycin protects rat heart cultures from hypoxic-reoxygenation (H/R) damage, as revealed by assays of lactate dehydrogenase (LDH) and creatine kinase (CK) leakage to the medium, by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-d...

2011-01-01

474

Preparation of AgX (X = Cl, I) nanoparticles using ionic liquids

Pool critical assembly benchmark solutions using MCNP and THREEDANT

Nanoparticles of silver halides have been prepared by mixing silver halide powder with a single liquid phase consisting of an ionic liquid, isooctane, n-decanol and water. Much higher nanoparticle concentrations may be formed with ionic liquids using this new simple method than are found with conventionally applied surfactants. This method also emphasizes the applicability of ionic liquids as versatile components in microemulsions and as solvents for the synthesis of nanomaterials. The effect on the nanoparticles of changing the composition of the liquid mixtures and the nature of the ionic liquid is analysed. High nanoparticle concentrations were only found with chloride based ionic liquids, indicating the importance of the ionic liquid anion in the mechanism of the reaction.

2008-03-12

475

Palladium polypyridyl complexes: synthesis, characterization, DNA interaction and biological activity on Leishmania (L.) mexicana

Analyses of pressure vessel damage resulting from neutron irradiation have primarily relied on two-dimensional transport calculations and a spatial-synthesis methodology to accommodate three-dimensional effects in the results of two two-dimensional calculations. In this paper, the authors report on calculations made on the Pool Critical Assembly (PCA) Benchmark, Configuration 12/13, using the three-dimensional, continuous energy Monte Carlo transport code, MCNP, and the three-dimensional, multigroup, diffusion accelerated discrete ordinates transport code THREEDANT. Neutron fluxes and activation rates as determined from these two calculations are compared to each other and to experimental results in the literature. The authors also draw some conclusions on the value of 3D calculations on the interpretation of experimental results.

1994-12-31

476

One-step synthesis of reduced graphite oxide-silver nanocomposite

This paper describes the search for new potential chemotherapeutic agents based on transition metal complexes with planar ligands. In this study, palladium polypyridyl complexes were synthesized and characterized by elemental analysis, NMR, UV-VIS and IR spectroscopies. The interaction of the complexes with DNA was also investigated by spectroscopic methods. All metal-to-ligand charge transfer (MLCT) bands of the palladium polypyridyl complexes exhibited hypochromism and red shift in the presence of DNA. The binding constant and viscosity data suggested that the complexes [PdCl{sub 2}(phen)] and [PdCl{sub 2}(phendiamine)] interact with DNA by electrostatic forces. Additionally, these complexes induced an important leishmanistatic effect on L. (L.) mexicana promastigotes at the final concentration of 10 {mu}mol L{sup -1} in 48 h. (author)

2008-07-01

477

British Library Electronic Table of Contents (United Kingdom)

Here, a general approach for the preparation of reduced graphite oxide (rGO)-silver nanocomposite has been investigated. Graphite oxide (GO) sheets are used as the nanoscale substrates for the formation of rGO-silver composite. GO sheets and Ag ions can be reduced at the same time, under a mild condition using l-ascorbic acid (l-AA) as reducing agent. This simple approach should find practical applications in the production of rGO-silver nanocomposite. The SEM analysis indicates that the silver particles are dispersed on graphene sheets. Raman signals of rGO in the composite are increased by the attached silver nanoparticles, displaying surface-enhanced Raman scattering activity. The degree of enhancement can be adjusted by varying the quantity of silver nanoparticles in the composite. In ...

2011-01-01

478

Microemulsion-mediated synthesis of cobalt (pure fcc and hexagonal phases) and cobalt-nickel alloy nanoparticles

British Library Electronic Table of Contents (United Kingdom)

By choosing appropriate microemulsion systems, hexagonal cobalt (Co) and cobalt-nickel (1:1) alloy nanoparticles have been obtained with cetyltrimethylammonium bromide as a cationic surfactant at 500degreeC. This method thus stabilizes the hcp cobalt even at sizes (<10nm) at which normally fcc cobalt is predicted to be stable. On annealing the hcp cobalt nanoparticles in H2 at 700degreeC we could transform them to fcc cobalt nanoparticles. Microscopy studies show the formation of spherical nanoparticles of hexagonal and cubic forms of cobalt and Co-Ni (1:1) alloy nanoparticles with the average size of 4, 8 and 20nm, respectively. Electrochemical studies show that the catalytic property towards oxygen evolution is dependent on the applied voltage. At low voltage (less than 0.65V) the Co (he...

2009-01-01

479

Log live high activity radioactive wastes / Researches and results law of the 30 December 1991. Separation and transmutation of long lived radionuclides; Les dechets radioactifs a haute activite et a vie longue / recherches et resultats Loi du 30 decembre 1991. Separation et transmutation des radionucleides a vie longue

Ionic conduction in polyether-based lithium arylfluorosulfonimide ionic melt electrolytes

The law of the 30 December 1991 on the high activity long lived radioactive wastes reached the end. This synthesis final document presents the scientific and technological results, obtained still the end of 2005, on the separation and the transmutation of long lived radionuclides of high activity long lived radioactive wastes. It is organized in five chapters: a presentation of the context and the historical aspects, the researches, the objectives and the strategy of the axis 1, the researches results on the advanced separation, the researches results on the transmutation, the scenario of separation-transmutation and their environmental, technical and economical impacts. (A.L.B.)

2005-12-15

480

Ionic conduction in polyether-based lithium arylfluorosulfonimide ionic melt electrolytes

We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10{sup -6} S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

2009-10-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

481

Green synthesis of iron nanoparticles and their application as a Fenton-like catalyst for the degradation of aqueous cationic and anionic dyes

We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10-6 S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

2009-10-01

482

British Library Electronic Table of Contents (United Kingdom)

Iron nanoparticles were produced using extracts of green tea leaves (GT-Fe NPs). The materials were characterized using TEM, SEM/EDX, XPS, XRD, and FTIR techniques and were shown to contain mainly iron oxide and iron oxohydroxide. The obtained nanoparticles were then utilized as a Fenton-like catalyst for decolorization of aqueous solutions containing methylene blue (MB) and methyl orange (MO) dyes. The related experiments investigated the removal kinetics and the effect of concentration for both MB and MO. The concentrations of dyes in aqueous solution were monitored using ultraviolet-visible (UV-vis) spectroscopy. The results indicated fast removal of the dyes with the kinetic data of MB following a second order removal rate, while those of MO were closer to a first order removal rate. T...

2011-01-01

483

Gasification of waste from furniture industries for generation of sustainable energy

Formation of Cu2O Quantum Dots on SrTiO3 (100): Self-Assembly and Directed Self-Assembly

The global interest in renewable energy is attributed to the decline in fossil fuel sources and the need for technical, economic, social and environmental sustainability. This study focused on the new techniques that have been developed for the use of biomass for energy from wood wastes from the forest-based industry. As an energy source, wood waste contributes positively to the environment by reducing environmental problems related to contamination of soil, air and water through improper disposal of waste. Biomass gasification has the advantage of converting biomass into a combustible gas that can be used for heat generation, electricity and synthesis of chemicals. Syngas produced from gasification of eucalyptus residues has significant potential, with an average High Heating Value of 6.60 MJ/m{sup 3}, and regular composition during the process, with predominance of carbon monoxide, followed by hydrogen, carbon dioxide and methane.

2010-07-01

484

Forkhead box protein P1 as a downstream target of transforming growth factor-b induces collagen synthesis and correlates with a more stable plaque phenotype

Nanoscale islands of Cu2O have been synthesized on single-crystal SrTiO3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (OPA-MBE). Island growth location has been controlled by using an ex-situ Ga+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. Analysis of Cu2O dot growth on unmodified substrate regions revealed an evolution of dot size and array density. Atomic force microscopy studies show that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of islands. Islands initially formed in the FIB-generated surface topography and filled those features before nucleating on neighboring unmodified surface regions.

2006-11-09

485

British Library Electronic Table of Contents (United Kingdom)

Objective: Atherosclerosis is an inflammatory disease, modulated by plaque stabilizing and de-stabilizing cell populations such as infiltrating monocytes and vascular smooth muscle cells (vSMCs). Transcription factors regulating proliferation and differentiation of atherosclerosis relevant cell types are of interest in this context. The forkhead box transcription factor FoxP1 modulates monocyte differentiation. We studied FoxP1 expression in atherosclerotic tissue, correlated FoxP1 expression with plaque characteristics and identified associations between FoxP1 and plaque proteins. Methods: 116 Atherosclerotic plaques from carotid endarterectomy samples were histologically classified (fibrous, fibroatheromatous, atheromatous) and subjected to semi-quantitative protein analysis. Macrophage,...

2011-01-01

486

Focused-ion-beam directed self-assembly of Cu_2O islands on SrTiO_3(100)

Electrostatic droplets assisted synthesis of alginate microcapsules

Nanoscale islands of Cu_2O have been synthesized on single-crystal SrTiO_3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (MBE). Island growth location has been controlled by using an ex situ Ga"+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex situ atomic force microscopy study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.

2004-06-21

487

British Library Electronic Table of Contents (United Kingdom)

This paper demonstrates a proof-of-concept approach for encapsulating the insulin and Fe3O4 nanoparticles into size-controllable alginate microcapsules utilizing the electrostatic droplets (ESD) technique. We have established that the combination of ESD and external gelation is quite effective in producing uniform-sized polymer particles. In addition, using the external gelation technique, the droplets containing a sodium-alginate were gelled in situ by immersion in Ca2+, Ba2+, or Cu2+ ions for a few minutes. The results show that different-type divalent cations caused various surface features to appear on the microcapsules (e.g., cracking, orange peel, pitting, splitting, wrinkling, etc.). The particle size can be adjusted from a few micrometers to ca. 1,000??m by electrostatic force. The...

2011-01-01

488

Electrogenerated chemiluminescence sensor for itopride with Ru(bpy)32+-doped silica nanoparticles/chitosan composite films modified electrode

British Library Electronic Table of Contents (United Kingdom)

A electrogenerated chemiluminescence (ECL) sensor for itopride was developed based on tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)32+)-doped silica (RuDS) nanoparticles/biopolymer chitosan composites membrane modified glassy carbon electrode (GCE). The RuDS nanoparticles (52+-5nm) were prepared by a modified Stber synthesis method and were characterized by electrochemical, fluorometric and transmission electron microscopy technology. The Ru(bpy)32+ encapsulation interior of the silica nanoparticle maintains its electrochemical activities and also reduces Ru(bpy)32+ leaching from the silica matrix when immersed in water due to the electrostatic interaction. The ECL analytical performances of this ECL sensor for itopride based on its enhancement ECL emission of Ru(bpy)32+ were investigated in d...

2008-01-01

489

Electrochemical method for the synthesis of silver nanoparticles

Double promotion of palladium/silica catalysts by iron and magnesium oxide in the synthesis of methanol from carbon monoxide and hydrogen

The article deals with a novel electrochemical method of preparing long-lived silver nanoparticles suspended in aqueous solution as well as silver powders. The method does not involve the use of any chemical stabilising agents. The morphology of the silver nanoparticles obtained was studied using transmission electron microscopy, scanning electron microscopy, atomic force microscopy and dynamic light scattering measurements. Silver nanoparticles suspended in water solution that were produced by the present technique are nearly spherical and their size distribution lies in the range of 2 to 20 nm, the average size being about 7 nm. Silver nanoparticles synthesised by the proposed method were sufficiently stable for more than 7 years even under ambient conditions. Silver crystal growth on the surface of the cathode in the electrochemical process used was shown to result in micron-sized structures consisting of agglomerated silver nanoparticles with the sizes below 40 nm.

2009-07-15

490

Design, synthesis and evaluation of 2-deoxy-2-iodovinyl-branched carbohydrates as potential brain imaging agents

The structure and catalytic properties of 2 wt.-% Pd/SiO/sub 2/ catalysts promoted with 2 wt.-% MgO and 0.2-5 wt.-% iron have been investigated. Catalysts were characterized by TPR, hydrogen chemisorption, and Moessbauer spectroscopy and their catalytic performance in methanol formation was also measured. At 16 at.-% iron a sharp maximum was observed in the activity which can be interpreted as being due to simultaneous promotion with iron and MgO. Independent mechanisms of promotion were found for the two modifiers: iron influenced the metallic component by forming bimetallic PdFe particles while MgO changed the properties of silica in a favourable way. 6 figs., 29 refs., 1 tab.

1988-12-01

491

Design, synthesis and evaluation of 2-deoxy-2-iodovinyl-branched carbohydrates as potential brain imaging agents

Radioiodinated carbohydrates such as 2-deoxy-2-iodo-D-glucose and 3-deoxy-3-iodo-D-glucose undergo facile chemical or in vivo deiodination which precludes their use as radiotracers of glucose metabolism in tissues. To overcome the problems resulting from in vivo deiodination, we explored the concept of stabilizing radioiodide on a model carbohydrate, (E)-C-3-iodovinyl-D-allose (10) as an iodovinyl moiety. This agent did not exhibit brain specificity but showed low in vivo deiodination which demonstrated for the first time that radioiodide can be stabilized on a carbohydrate. The goal of this study was to develop a deoxy-branched carbohydrate with radioiodide stabilized as a vinyliodide with the objective of achieving high brain uptake. 10 refs., 1 fig., 1 tab.

2007-01-01

492

Coordinated synthesis of multimachine power system stabilizer using an efficient decentralized modal control (DMC) algorithm

Radioiodinated carbohydrates such as 2-deoxy-2-iodo-D-glucose and 3-deoxy-3-iodo-D-glucose undergo facile chemical or in vivo deiodination which precludes their use as radiotracers of glucose metabolism in tissues. To overcome the problems resulting from in vivo deiodination, we explored the concept of stabilizing radioiodide on a model carbohydrate, (E)-C-3-iodovinyl-D-allose as an iodovinyl moiety. This agent did not exhibit brain specificity but showed low in vivo deiodination which demonstrated for the first time that radioiodide can be stabilized on a carbohydrate. The goal of this study was to develop a deoxy-branched carbohydrate with radioiodide stabilized as a vinyliodide with the objective of achieving high brain uptake. (author).

493

Communication Estimation for Hardware/Software Codesign

This paper presents a new method for simultaneously selecting the power system stabilizer (PSS) parameters in multimachine power systems. Design of local output feedback power system stabilizer using local signal of the generator (e.g. speed or power) is formulated as a decentralized modal control (DMC) problem. Exact model reduction based on modal control theory is proposed to make the determination of PSS parameters highly efficient. Results obtained from the coordinated tuning of the parameters of three power system stabilizers equipped on a multimachine power system show that exact assignment of the eigenvalues associated with the poorly damped electromechanical modes can be achieved in a very efficient manner.

1986-01-01

494

Chemical sensors based on surface-confined dendrimers

This paper presents a general high level estimation model of communication throughput for the implementation of a given communication protocol. The model, which is part of a larger model that includes component price, software driver object code size and hardware driver area, is intended to be general enough to be able to capture the characteristics of a wide range of communication protocols and yet to be sufficiently detailed as to allow the designer or design tool to efficiently explore tradeoffs between throughput, bus widths, burst/non-burst transfers and data packing strategies. Thus it provides a basis for decision making with respect to communication protocols/components and communication driver design in the initial design space exploration phase of a co-synthesis process where a large number of possibilities must be examined and where fast estimators are therefore necessary. The fill model allows for additional (money) cost, software code size and hardware ...

1998-01-01

495

A novel single-step synthesis of N-doped TiO"2 via a sonochemical method

The use of dendrimers for preparing chemically sensitive interfaces for detecting volatile organic compounds (VOCs) using surface acoustic wave (SAW) device transducers is described. Specifically, the synthesis of the dendrimers and the means by which they are affixed to SAW devices is discussed, followed by a detailed spectroscopic analysis of the surface-confined dendrimers and a discussion of their interaction with different VOCs. Most of these preliminary experiments focus on dendrimer surface modification using benzoylchloride, which leads to phenyl terminal groups linked to the dendrimer via amide groups. The results of this study lead us to conclude that dendrimers: (1) provide general specificity towards classes of functional groups and are therefore suitable for array-based sensing schemes; (2) are intermediate in structure between monolayers and polymers and exhibit the desirable properties of both; (3) can be straightforwardly attached to the surfaces of ...

1997-10-01

496

British Library Electronic Table of Contents (United Kingdom)

A novel single-step synthetic method for the preparation of anatase N-doped TiO"2 nanocrystalline at low temperature has been devoleped. The N-doped anatase TiO"2 nanoparticles were synthesized by sonication of the solution of tetraisopropyl titanium and urea in water and isopropyl alcohol at 80^oC for 150min. The as-prepared sample was characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectrum. The product structure depends on the reaction temperature and reaction time. The photocatalytic activity of the as-prepared photocatalyst was evaluated via the photodegradation of an azo dye direct sky blue 5B. The results show that the N-doped TiO"2 nanocrystalline prepared via sonication exhibit an excellent photocatalytic...

2011-01-01

497

A facile and green preparation of high-quality CdTe semiconductor nanocrystals at room temperature

6-Substituted imidazo[1,2-a]pyridines: Synthesis and biological activity against colon cancer cell lines HT-29 and Caco-2

One chemical reagent, hydrazine hydrate, was discovered to accelerate the growth of semiconductor nanocrystals (cadmium telluride) instead of additional energy, which was applied to the synthesis of high-quality CdTe nanocrystals at room temperature and ambient conditions within several hours. Under this mild condition the mercapto stabilizers were not destroyed, and they guaranteed CdTe nanocrystal particle sizes with narrow and uniform distribution over the largest possible range. The CdTe nanocrystals (photoluminescence emission range of 530-660 nm) synthesized in this way had very good spectral properties; for instance, they showed high photoluminescence quantum yield of up to 60%. Furthermore, we have succeeded in detecting the living Borrelia burgdorferi of Lyme disease by its photoluminescence image using CdTe nanocrystals.

2008-06-18

498

British Library Electronic Table of Contents (United Kingdom)

A range of 6-substituted imidazo[1,2-a]pyridines were synthesized using a multicomponent coupling reaction. Most of these compounds were found to exhibit excellent activity against the colon cancer cell lines HT-29 and Caco-2, whilst not showing significant toxicity against white blood cells. Our studies have shown that the proteolytic phase of apoptosis was initiated 2 h after treatment with these imidazo-[1,2-a]pyridines. The data suggests that the imidazo[1,2-a]pyridine-induced cell death in HT-29 and Caco-2 cells is mediated via pathway(s) that include the release of cytochrome c from the mitochondria to the cytosol and the activation of caspase 3 and caspase 8.

2011-01-01

499

5,8,11,14-Eicosatetraynoic acid-induced destruction of mitochondria in human prostate cells (PC-3).