Tailorable Trimethyl chitosans as adjuvant for intranasal immunization

NARCIS (Netherlands)

Verheul, R.J.

2010-01-01

Tailorable Trimethyl Chitosans as Adjuvant for Intranasal Immunization Active vaccination has proven to be the most (cost) effective tool in the fight against infectious diseases. Nowadays, most vaccines are administered via parenteral injection. However, the risk of contaminated needles and need

Synthesis, characterization, magnetic and electrochemical properties of a new 3D hexa-copper-substituted germanotungstate

International Nuclear Information System (INIS)

Li, Yanzhou; Luo, Jie; Zhang, Yanting; Zhao, Junwei; Chen, Lijuan; Ma, Pengtao; Niu, Jingyang

2013-01-01

An inorganic–organic hybrid hexa-copper-substituted germanotungstate Na 2 [Cu(dap) 2 ] 2 [Cu(dap) 2 ] ([Cu 6 (H 2 O) 2 (dap) 2 ][B-α-GeW 9 O 34 ] 2 )·4H 2 O (1) (dap=1,2-diaminopropane) has been hydrothermally prepared and characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP–AES) analyses, IR spectra, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. 1 displays the six-connected 3D network with the long topological (O′Keefe) vertex symbol is 4·4·6 4 ·4·4·4·4·6 4 ·4·4·4·6 4 ·4·4·4 and the short vertex (Schläfli) symbol of 4 12 6 3 . Magnetic measurements indicate that there are the overall ferromagnetic exchange interactions in the belt-like hexa-Cu II cluster in 1. Furthermore, the electrochemical behavior and electrocatalysis of 1 modified carbon paste electrode (1-CPE) have been studied. The reductions of nitrite, bromate and hydrogen peroxide are principally mediated by the W VI -based wave. - Graphical abstract: A hexa-Cu II sandwiched germanotungstate has been synthesized and structurally characterized. The magnetic, solid-state electrochemical and electrocatalytic properties have been investigated. Display Omitted - Highlights: • Transition-metal substituted polyoxometalates. • Hexa-copper-substituted germanotungstate. • Six-connected 3D network. • Electrocatalytic reduction of nitrite, bromate and hydrogen peroxide

Synergistic extraction of actinides : Part I. Hexa-and pentavalent actinides

International Nuclear Information System (INIS)

Patil, S.K.; Ramakrishna, V.V.

1980-01-01

A detailed discussion on the reported literature on the synergistic extraction of hexa- and pentavalent actinide ions, by different combinations of extractants and from different aqueous media, is presented. Structural aspects of the various complexes involved in synergism also are reviewed. A short account of the applications based on synergistic extraction is also given. (author)

Fragrance material review on β,β,3-trimethyl-benzenepropanol.

Science.gov (United States)

Scognamiglio, J; Jones, L; Letizia, C S; Api, A M

2012-09-01

A toxicologic and dermatologic review of β,β,3-trimethyl-benzenepropanol when used as a fragrance ingredient is presented. β,β,3-Trimethyl-benzenepropanol is a member of the fragrance structural group Aryl Alkyl Alcohols and is a primary alcohol. The AAAs are a structurally diverse class of fragrance ingredients that includes primary, secondary, and tertiary alkyl alcohols covalently bonded to an aryl (Ar) group, which may be either a substituted or unsubstituted benzene ring. The common structural element for the AAA fragrance ingredients is an alcohol group -C-(R1)(R2)OH and generically the AAA fragrances can be represented as an Ar-C-(R1)(R2)OH or Ar-Alkyl-C-(R1)(R2)OH group. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for β,β,3-trimethyl-benzenepropanol were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, photoallergy, repeated dose, and genotoxicity data. A safety assessment of the entire Aryl Alkyl Alcohols will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all Aryl Alkyl Alcohols in fragrances. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of nickel treatment on H3K4 trimethylation and gene expression.

Directory of Open Access Journals (Sweden)

Kam-Meng Tchou-Wong

Full Text Available Occupational exposure to nickel compounds has been associated with lung and nasal cancers. We have previously shown that exposure of the human lung adenocarcinoma A549 cells to NiCl(2 for 24 hr significantly increased global levels of trimethylated H3K4 (H3K4me3, a transcriptional activating mark that maps to the promoters of transcribed genes. To further understand the potential epigenetic mechanism(s underlying nickel carcinogenesis, we performed genome-wide mapping of H3K4me3 by chromatin immunoprecipitation and direct genome sequencing (ChIP-seq and correlated with transcriptome genome-wide mapping of RNA transcripts by massive parallel sequencing of cDNA (RNA-seq. The effect of NiCl(2 treatment on H3K4me3 peaks within 5,000 bp of transcription start sites (TSSs on a set of genes highly induced by nickel in both A549 cells and human peripheral blood mononuclear cells were analyzed. Nickel exposure increased the level of H3K4 trimethylation in both the promoters and coding regions of several genes including CA9 and NDRG1 that were increased in expression in A549 cells. We have also compared the extent of the H3K4 trimethylation in the absence and presence of formaldehyde crosslinking and observed that crosslinking of chromatin was required to observe H3K4 trimethylation in the coding regions immediately downstream of TSSs of some nickel-induced genes including ADM and IGFBP3. This is the first genome-wide mapping of trimethylated H3K4 in the promoter and coding regions of genes induced after exposure to NiCl(2. This study may provide insights into the epigenetic mechanism(s underlying the carcinogenicity of nickel compounds.

Synthesis, characterization, magnetic and electrochemical properties of a new 3D hexa-copper-substituted germanotungstate

Energy Technology Data Exchange (ETDEWEB)

Li, Yanzhou; Luo, Jie; Zhang, Yanting [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); Zhao, Junwei, E-mail: zhaojunwei@henu.edu.cn [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); Basic Experiment Teaching Center, Henan University, Kaifeng, Henan 475004 (China); Chen, Lijuan, E-mail: ljchen@henu.edu.cn [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Ma, Pengtao; Niu, Jingyang [Institute of Molecular and Crystal Engineering, Henan Key Lab of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China)

2013-09-15

An inorganic–organic hybrid hexa-copper-substituted germanotungstate Na{sub 2}[Cu(dap){sub 2}]{sub 2}[Cu(dap){sub 2}] ([Cu{sub 6}(H{sub 2}O){sub 2}(dap){sub 2}][B-α-GeW{sub 9}O{sub 34}]{sub 2})·4H{sub 2}O (1) (dap=1,2-diaminopropane) has been hydrothermally prepared and characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP–AES) analyses, IR spectra, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. 1 displays the six-connected 3D network with the long topological (O′Keefe) vertex symbol is 4·4·6{sub 4}·4·4·4·4·6{sub 4}·4·4·4·6{sub 4}·4·4·4 and the short vertex (Schläfli) symbol of 4{sup 12}6{sup 3}. Magnetic measurements indicate that there are the overall ferromagnetic exchange interactions in the belt-like hexa-Cu{sup II} cluster in 1. Furthermore, the electrochemical behavior and electrocatalysis of 1 modified carbon paste electrode (1-CPE) have been studied. The reductions of nitrite, bromate and hydrogen peroxide are principally mediated by the W{sup VI}-based wave. - Graphical abstract: A hexa-Cu{sup II} sandwiched germanotungstate has been synthesized and structurally characterized. The magnetic, solid-state electrochemical and electrocatalytic properties have been investigated. Display Omitted - Highlights: • Transition-metal substituted polyoxometalates. • Hexa-copper-substituted germanotungstate. • Six-connected 3D network. • Electrocatalytic reduction of nitrite, bromate and hydrogen peroxide.

Synthesis,thermal property and hydrolytic degradation of a novel star-shaped hexa[p-(carbonylglycinomethylester)phenoxy]cyclotriphosphazene

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

A novel star-shaped cyclotriphosphazene substituted by glycinomethylesterphenoxy and its intermediates are synthesized from hexachlorocyclotriphosphazene (HCCP). The structures are characterized by 1H NMR,13C NMR,31P NMR,FTIR and elemental analysis. Their thermal properties are clarified by thermogravimetric analysis (TGA),differential scanning calorimentry (DSC) and FTIR,while hydrolytic degradation behaviour is studied with UV-vis spectrophotometer and by measuring the weight loss,and the phosphorus content of residue. According to hydrolysis behaviour of hexa[p-(carbonylglycinomethylester)phenoxy]cyclotriphosphazene (HGPCP) under different conditions,it is easy to hydrolyze in hydrochloric acid (pH 1.0) than in phosphate buffer (pH 7.4) at 37℃. And the sample hydrolytic degradation still remains at the stage of side groups’ break. The TGA data show that the thermal stability of the hexa[p-(aldehyde)phenoxy]cyclotriphosphazene (HAPCP),hexa[p-(carboxyl) phenoxy]cyclotriphosphazene (HCPCP) and HGPCP is so high that their char residues are 75%,47% and 47% at 800℃,respectively,probably due to cross-linking between molecules.

Measurements of temperature of the tungsten hexa-ethoxide pyrolysis flame using IR camera

CSIR Research Space (South Africa)

Mudau, AE

2010-09-01

Full Text Available In laser pyrolysis, temperature measurement and control plays a vital role during the development of nanoparticles. Authors present the results of temperature measurements using infrared camera on a tungsten hexa-ethoxide pyrolysis flame used...

Tay–Sachs disease mutations in HEXA target the α chain of hexosaminidase A to endoplasmic reticulum–associated degradation

Science.gov (United States)

Dersh, Devin; Iwamoto, Yuichiro; Argon, Yair

2016-01-01

Loss of function of the enzyme β-hexosaminidase A (HexA) causes the lysosomal storage disorder Tay–Sachs disease (TSD). It has been proposed that mutations in the α chain of HexA can impair folding, enzyme assembly, and/or trafficking, yet there is surprisingly little known about the mechanisms of these potential routes of pathogenesis. We therefore investigated the biosynthesis and trafficking of TSD-associated HexA α mutants, seeking to identify relevant cellular quality control mechanisms. The α mutants E482K and G269S are defective in enzymatic activity, unprocessed by lysosomal proteases, and exhibit altered folding pathways compared with wild-type α. E482K is more severely misfolded than G269S, as observed by its aggregation and inability to associate with the HexA β chain. Importantly, both mutants are retrotranslocated from the endoplasmic reticulum (ER) to the cytosol and are degraded by the proteasome, indicating that they are cleared via ER-associated degradation (ERAD). Leveraging these discoveries, we observed that manipulating the cellular folding environment or ERAD pathways can alter the kinetics of mutant α degradation. Additionally, growth of patient fibroblasts at a permissive temperature or with chemical chaperones increases cellular Hex activity by improving mutant α folding. Therefore modulation of the ER quality control systems may be a potential therapeutic route for improving some forms of TSD. PMID:27682588

Rapid identification of HEXA mutations in Tay-Sachs patients.

Science.gov (United States)

Giraud, Carole; Dussau, Jeanne; Azouguene, Emilie; Feillet, François; Puech, Jean-Philippe; Caillaud, Catherine

2010-02-19

Tay-Sachs disease (TSD) is a recessively inherited neurodegenerative disorder due to mutations in the HEXA gene resulting in a beta-hexosaminidase A (Hex A) deficiency. The purpose of this study was to characterize the molecular abnormalities in patients with infantile or later-onset forms of the disease. The complete sequencing of the 14 exons and flanking regions of the HEXA gene was performed with a unique technical condition in 10 unrelated TSD patients. Eleven mutations were identified, including five splice mutations, one insertion, two deletions and three single-base substitutions. Four mutations were novel: two splice mutations (IVS8+5G>A, IVS2+4delAGTA), one missense mutation in exon 6 (c.621T>G (p.D207E)) and one small deletion (c.1211-1212delTG) in exon 11 resulting in a premature stop codon at residue 429. The c.621T>G missense mutation was found in a patient presenting an infantile form. Its putative role in the pathogenesis of TSD is suspected as residue 207 is highly conserved in human, mouse and rat. Moreover, structural modelling predicted changes likely to affect substrate binding and catalytic activity of the enzyme. The time-saving procedure reported here could be useful for the characterization of Tay-Sachs-causing mutations, in particular in non-Ashkenazi patients mainly exhibiting rare mutations. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Methods of use of calcium hexa aluminate refractory linings and/or chemical barriers in high alkali or alkaline environments

Science.gov (United States)

McGowan, Kenneth A; Cullen, Robert M; Keiser, James R; Hemrick, James G; Meisner, Roberta A

2013-10-22

A method for improving the insulating character/and or penetration resistance of a liner in contact with at least one of an alkali and/or alkaline environments is provided. The method comprises lining a surface that is subject to wear by an alkali environment and/or an alkaline environment with a refractory composition comprising a refractory aggregate consisting essentially of a calcium hexa aluminate clinker having the formula CA.sub.6, wherein C is equal to calcium oxide, wherein A is equal to aluminum oxide, and wherein the hexa aluminate clinker has from zero to less than about fifty weight percent C.sub.12A.sub.7, and wherein greater than 98 weight percent of the calcium hexa aluminate clinker having a particle size ranging from -20 microns to +3 millimeters, for forming a liner of the surface. This method improves the insulating character/and or penetration resistance of the liner.

Improving accuracy of Tay Sachs carrier screening of the non-Jewish population: analysis of 34 carriers and six late-onset patients with HEXA enzyme and DNA sequence analysis.

Science.gov (United States)

Park, Noh Jin; Morgan, Craig; Sharma, Rajesh; Li, Yuanyin; Lobo, Raynah M; Redman, Joy B; Salazar, Denise; Sun, Weimin; Neidich, Julie A; Strom, Charles M

2010-02-01

The purpose of this study was to determine whether combining different testing modalities namely beta-hexosaminidase A (HEXA) enzyme analysis, HEXA DNA common mutation assay, and HEXA gene sequencing could improve the sensitivity for carrier detection in non-Ashkenazi (AJ) individuals. We performed a HEXA gene sequencing assay, a HEXA DNA common mutation assay, and a HEXA enzyme assay on 34 self-reported Tay-Sachs disease (TSD) carriers, six late-onset patients with TSD, and one pseudodeficiency allele carrier. Sensitivity of TSD carrier detection was 91% for gene sequencing compared with 91% for the enzyme assay and 52% for the DNA mutation assay. Gene sequencing combined with enzyme testing had the highest sensitivity (100%) for carrier detection. Gene sequencing detected four novel mutations, three of which are predicted to be disease causing [118.delT, 965A-->T (D322V), and 775A-->G (T259A)]. Gene sequencing is useful in identifying rare mutations in patients with TSD and their families, in evaluating spouses of known carriers for TSD who have indeterminate enzyme analysis and negative for common mutation analysis, and in resolving ambiguous enzyme testing results.

Biological significance of lysine mono-, di- and trimethylation on histone and non-histone proteins

International Nuclear Information System (INIS)

Perez-Burgos, L.

2006-01-01

Histones are the proteins that compact DNA into the repeating unit of chromatin known as the nucleosome. The N-termini of histones are subject to a series of post-translational modifications, one of which is methylation. This modification is termed 'epigenetic' because it extends the information encoded in the genome. Lysines can be mono-, di- or tri-methylated at different positions on histones H1, H3 and H4. In order to study the biological role of histone lysine methylation, antibodies were generated against mono-, di- and trimethylated H3-K9 and H3-27. Indeed, different chromatin domains in the mouse nucleus are enriched in distinct forms of histone lysine methylation, such as pericentric heterochromatin and the inactive X chromosome. Interestingly, heterochromatin in Arabidopsis thaliana is enriched in the mono- and di-, but not the trimethylated form of H3-K9. Furthermore, there exists a hierarchy of epigenetic modifications in which H3-K9 trimethylation is found to be upstream of DNA methylation on mouse major satellites. Histone lysine methylation is also involved in gene regulation upon development. One example is the chicken 61538;-globin locus, a region of facultative chromatin that undergoes a loss of di- and trimethylated H3-K27 in mature red blood cells, concomitant with expression of the 61538;-globin genes. SET-domain proteins are enzymes that methylate histones, but some of them are also able to methylate non-histone substrates. In particular, p53 is methylated by Set9 on lysine 372, G9a and Glp-1 on lysine 373 and by Smyd2 on lysine 370. Smyd2 transcript levels are greatly increased upon irradiation and dimethylated p53-370 specifically binds to 53BP1, a protein involved in recognizing DNA double-stranded breaks upon ionizing radiation. These results argue for a novel role of p53-K370 methylation in the biology of DNA damage. In summary, lysine methylation is a post-translational modification that can occur both on histone and non-histone proteins

GM2 gangliosidoses in Spain: analysis of the HEXA and HEXB genes in 34 Tay-Sachs and 14 Sandhoff patients.

Science.gov (United States)

Gort, Laura; de Olano, Natalia; Macías-Vidal, Judit; Coll, M A Josep

2012-09-10

The GM2 gangliosidoses are autosomal recessive lysosomal storage diseases caused by a deficiency of the β-hexosaminidase A enzyme. This enzyme is composed of two polypeptide chains designated the α- and β- subunits and it interacts with the GM2 activator protein. The HEXA and HEXB genes encode the α-subunit and the β-subunit, respectively. Mutations in these genes are causative of Tay-Sachs disease (HEXA) and Sandhoff disease (HEXB). We analyzed the complete HEXA gene in 34 Spanish patients with Tay-Sachs disease and the HEXB gene in 14 Spanish patients with Sandhoff disease. We identified 27 different mutations, 14 of which were novel, in the HEXA gene and 14 different mutations, 8 of which unreported until now, in the HEXB gene, and we attempted to correlate these mutations with the clinical presentation of the patients. We found a high frequency of c.459+5G>A (IVS4+5G>A) mutation in HEXA affected patients, 22 of 68 alleles, which represent the 32.4%. This is the highest percentage found of this mutation in a population. All patients homozygous for mutation c.459+5G>A presented with the infantile form of the disease and, as previously reported, patients carrying mutation p.R178H in at least one of the alleles presented with a milder form. In HEXB affected patients, the novel deletion c.171delG accounts for 21.4% of the mutant alleles (6/28). All patients with this deletion showed the infantile form of the disease. The Spanish GM2 gangliosidoses affected patients show a great mutational heterogeneity as seen in other inherited lisosomal diseases in this country. Copyright © 2012. Published by Elsevier B.V.

GM2 gangliosidosis associated with a HEXA missense mutation in Japanese Chin dogs: a potential model for Tay Sachs disease.

Science.gov (United States)

Sanders, Douglas N; Zeng, Rong; Wenger, David A; Johnson, Gary S; Johnson, Gayle C; Decker, Jared E; Katz, Martin L; Platt, Simon R; O'Brien, Dennis P

2013-01-01

GM2 gangliosidosis is a fatal lysosomal storage disease caused by a deficiency of β-hexosaminidase (EC 3.2.1.52). There are two major isoforms of the enzyme: hexosaminidase A composed of an α and a β subunit (encoded by HEXA and HEXB genes, respectively); and, hexosaminidase B composed of two β subunits. Hexosaminidase A requires an activator protein encoded by GM2A to catabolize GM2 ganglioside, but even in the absence of the activator protein, it can hydrolyze the synthetic substrates commonly used to assess enzyme activity. GM2 gangliosidosis has been reported in Japanese Chin dogs, and we identified the disease in two related Japanese Chin dogs based on clinical signs, histopathology and elevated brain GM2 gangliosides. As in previous reports, we found normal or elevated hexosaminidase activity when measured with the synthetic substrates. This suggested that the canine disease is analogous to human AB variant of G(M2) gangliosidosis, which results from mutations in GM2A. However, only common neutral single nucleotide polymorphisms were found upon sequence analysis of the canine ortholog of GM2A from the affected Japanese Chins. When the same DNA samples were used to sequence HEXA, we identified a homozygous HEXA:c967G>A transition which predicts a p.E323K substitution. The glutamyl moiety at 323 is known to make an essential contribution to the active site of hexosaminidase A, and none of the 128 normal Japanese Chins and 92 normal dogs of other breeds that we tested was homozygous for HEXA:c967A. Thus it appears that the HEXA:c967G>A transition is responsible for the GM2 gangliosidosis in Japanese Chins. Copyright © 2012 Elsevier Inc. All rights reserved.

Fluorescence spectroscopic study of the aggregation behavior of non-cross-linked and cross-linked poly(alkylmethyldiallylammonium bromides) having decyl, octyl, and hexyl side chains in aqueous solution

NARCIS (Netherlands)

Wang, G.J; Engberts, J.B.F.N.

1996-01-01

The conformational state of a series of non-cross-linked and cross-linked poly(alkylmethyldiallylammonium bromides) bearing decyl, octyl, and hexyl side chains ((CL)-CopolC1-10, (CL)-CopolC1-8, and (CL)-CopolC1-6, respectively) in aqueous solutions were investigated by fluorescence spectroscopy

Trichloro(1,4,7-trimethyl-1,4,7-triazacyclononane)chromium(III)

DEFF Research Database (Denmark)

Klitgaard, Søren Kegnaes; Schau-Magnussen, Magnus

2005-01-01

The 1,4,7-trimethyl-1,4,7-triazacyclononane (tmtacn) ligand has become one of the classic ligands in coordination chemistry (Wieghardt et al., 1982 [Wieghardt, K., Chaudhuri, P., Nuber, B. & Weiss, J. (1982). Inorg. Chem. 21, 3086-3090.] ). In recent years, tmtacn-metal complexes ...

Poloxamer surface modified trimethyl chitosan nanoparticles for the effective delivery of methotrexate in osteosarcoma.

Science.gov (United States)

Li, Shenglong; Xiong, Yuyuan; Zhang, Xiaojing

2017-06-01

The present work is an effort to explore the poloxamer-modified trimethyl chitosan (TMC) encapsulated MTX for osteosarcoma treatment in order to improve the therapeutic efficacy and minimize severe toxicity associated with the clinical usage of MTX. The methotrexate-loaded pluronic-chitosan nanoparticles (MTCN) was nanosized and exhibited a controlled release of drug from the carrier system. The MTCN showed higher accumulation in cell cytoplasm region evident by the high red fluorescence indicating its uptake through energy-dependent endocytosis process. MTCN exhibited the increased cytotoxicity in MG63 cells compared free MTX due to its enhanced cellular uptake. Especially, MTCN exhibited a superior apoptosis effect with bright chromatin condensation and nuclear fragmentation was observed and showed remarkably higher apoptosis (∼48%) compared to that of free drug. The results of this investigation clearly demonstrate that the poloxamer-modified trimethyl chitosan (TMC) seems to have a great potential as a drug carrier in cancer chemotherapy. The present research work offers immense scope for further exploitation of poloxamer-modified trimethyl chitosan (TMC) in future for the development of nanoparticulate drug delivery system for cancer chemotherapy. Copyright © 2017. Published by Elsevier Masson SAS.

Tay-Sachs disease mutations in HEXA target the α chain of hexosaminidase A to endoplasmic reticulum-associated degradation.

Science.gov (United States)

Dersh, Devin; Iwamoto, Yuichiro; Argon, Yair

2016-12-01

Loss of function of the enzyme β-hexosaminidase A (HexA) causes the lysosomal storage disorder Tay-Sachs disease (TSD). It has been proposed that mutations in the α chain of HexA can impair folding, enzyme assembly, and/or trafficking, yet there is surprisingly little known about the mechanisms of these potential routes of pathogenesis. We therefore investigated the biosynthesis and trafficking of TSD-associated HexA α mutants, seeking to identify relevant cellular quality control mechanisms. The α mutants E482K and G269S are defective in enzymatic activity, unprocessed by lysosomal proteases, and exhibit altered folding pathways compared with wild-type α. E482K is more severely misfolded than G269S, as observed by its aggregation and inability to associate with the HexA β chain. Importantly, both mutants are retrotranslocated from the endoplasmic reticulum (ER) to the cytosol and are degraded by the proteasome, indicating that they are cleared via ER-associated degradation (ERAD). Leveraging these discoveries, we observed that manipulating the cellular folding environment or ERAD pathways can alter the kinetics of mutant α degradation. Additionally, growth of patient fibroblasts at a permissive temperature or with chemical chaperones increases cellular Hex activity by improving mutant α folding. Therefore modulation of the ER quality control systems may be a potential therapeutic route for improving some forms of TSD. © 2016 Dersh et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Efficient and accurate stereotactic radiotherapy using flattening filter free beams and HexaPOD robotic tables

DEFF Research Database (Denmark)

Nielsen, Morten; Hansen, C. R.; Brink, C.

2016-01-01

Flattening filter free (FFF) high dose rate beam technique was introduced for brain stereotactic radiosurgery (SRS) and lung Stereotactic Body Radiotherapy (SBRT). Furthermore, a HexaPOD treatment table was introduced for the brain SRS to enable correction of rotational setup errors. 19 filter fl...

HexaMob—A Hybrid Modular Robotic Design for Implementing Biomimetic Structures

Directory of Open Access Journals (Sweden)

Sasanka Sankhar Reddy CH.

2017-10-01

Full Text Available Modular robots are capable of forming primitive shapes such as lattice and chain structures with the additional flexibility of distributed sensing. The biomimetic structures developed using such modular units provides ease of replacement and reconfiguration in co-ordinated structures, transportation etc. in real life scenarios. Though the research in the employment of modular robotic units in formation of biological organisms is in the nascent stage, modular robotic units are already capable of forming such sophisticated structures. The modular robotic designs proposed so far in modular robotics research vary significantly in external structures, sensor-actuator mechanisms interfaces for docking and undocking, techniques for providing mobility, coordinated structures, locomotions etc. and each robotic design attempted to address various challenges faced in the domain of modular robotics by employing different strategies. This paper presents a novel modular wheeled robotic design - HexaMob facilitating four degrees of freedom (2 degrees for mobility and 2 degrees for structural reconfiguration on a single module with minimal usage of sensor-actuator assemblies. The crucial features of modular robotics such as back-driving restriction, docking, and navigation are addressed in the process of HexaMob design. The proposed docking mechanism is enabled using vision sensor, enhancing the capabilities in docking as well as navigation in co-ordinated structures such as humanoid robots.

MLL2 conveys transcription-independent H3K4 trimethylation in oocytes

Czech Academy of Sciences Publication Activity Database

Hanna, C. W.; Taudt, A.; Huang, J.; Gahurová, Lenka; Kranz, A.; Andrews, S.; Dean, W.; Francis Stewart, A.; Colomé-Tatché, M.; Kelsey, G.

2018-01-01

Roč. 25, č. 1 (2018), s. 73-82 ISSN 1545-9993 Institutional support: RVO:67985904 Keywords : H3K4 trimethylation Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 12.595, year: 2016

Phase equilibria of microemulsion forming system n-decyl-(beta)-D-glucopyranoside/water/n-octane/1-butanol

DEFF Research Database (Denmark)

Kahl, Heike; Quitzsch, Konrad; Stenby, Erling Halfdan

1997-01-01

of multicomponent system is the coexistence of a highly structural liquid phase enriched with amphiphilic compounds and an excess water or an excess oil phase or both of them. The phase behaviour was studied experimentally by use of turbidity titration and HPLC measurements and theoretically by application...... of the UNIQUAC-equation and the UNIFAC-method. The UNIFAC-method is able to describe the phase behaviour in the quaternary system qualitatively, without fitting parameters. However, by applying the UNIQUAC-method, with adjustable parameters, it was only possible to model the ternary subsystems. The modelling......A systematic investigation of the phase behaviour involving microemulsions is presented with respect to experimental and calculated data for the four-component system n-decyl-(beta)-D-glucopyranoside/water/n-octane/1-butanol and its corresponding ternaries at 25°C. The main feature of this kind...

Local Structure in Americium and Californium Hexa-cyanoferrates - Comparison with Their Lanthanide Analogues

International Nuclear Information System (INIS)

Dupouy, G.; Bonhoure, I.; Dumas, Th.; Moisy, Ph.; Petit, S.; Den Auwer, Ch.; Conradson, St.D.; Hennig, Ch.; Scheinost, A.C.; Le Naour, C.; Simoni, E.

2011-01-01

Metal hexa-cyanoferrates are well known molecular solids for a large variety of cations, although very little has been described for actinide adducts. Two new members of actinide(III) hexa-cyanoferrates were synthesized with the cations americium and californium. They were structurally characterized by infrared and X-ray absorption spectroscopy. Combined EXAFS data at the iron K edge and actinide L 3 edge provide evidence for a three-dimensional model for these two new compounds. Structural data in terms of bond lengths were compared to those reported for the parent lanthanide(III) compounds, neodymium and gadolinium hexa-cyanoferrates, respectively: the americium compound with (KNd(III)Fe(II)-Fe-III(CN) 6 .4H 2 O and the californium compound with (KGd(III)Fe(II)(CN) . 3.5H 2 O and (KGd(III)Fe(II)(CN) 6 .3H 2 O. This comparison between actinide and lanthanide homologues has been carried out on the basis of ionic radii considerations. The americium and neodymium environments appear to be very similar and are arranged in a tri-capped trigonal prism polyhedron of coordination number 9 (CN: 9), in which the americium atom is bonded to six nitrogen atoms and to three water molecules. For the californium adduct, a similar comparison and bond length and angle values derived from EXAFS studies suggest that the californium cation sits in a bi-capped trigonal prism (CN: 8) as in (KGd(III)Fe(II)(CN) 6 . 3H 2 O. This arrangement differs from that in the structure of (KGd(III)Fe(II)(CN) 6 .3.5H 2 O, in which the gadolinium atom is surrounded by 9 atoms. This is one of the rare pieces of information revealed by EXAFS spectroscopy for americium and californium in comparison to lanthanide atoms in molecular solid compounds. A discussion on the decrease in bond length and coordination number from americium to californium is also provided, on the basis of crystallographic results reported in the literature for actinide(III) and lanthanide(III) hydrate series. (authors)

Structure of methylene chloride addition product to zirconium tetrachloride complex with 1-tert.-butyl-2,4,4-trimethyl-2-thio-trimethylsilyl-1,3,2,4-diazaphosphasilatedine

International Nuclear Information System (INIS)

Brusilovets, A.I.; Rusanov, Eh.B.; Chernega, A.N.

1995-01-01

Complex of zirconium tetrachloride with 1-tert.-butyl-2,4,4-trimethyl--2-thio-3-trimethyl-silyl-1,3,2,4-diazaphosphasilatedine interacts with methylene chloride with formation of bis[3-tert.-butyl-2,4,4-trimethyl-1--trimethylsilyl-2-chloremethylthio-1,3,2,4-diazaphosphasilatedinium] decachlorodizirconate. Specific features of crystal and molecular structure of the compound prepared have been studied by X-ray diffraction method. 21 refs.; 2 figs.; 2 tabs

Accessibility of ribosomal genes to trimethyl psoralen in nuclei of Physarum polycephalum

International Nuclear Information System (INIS)

Judelson, H.S.; Vogt, V.M.

1982-01-01

The authors have probed the accessibility of the genes for rRNA in Physarum polycephalum by using the photoreactive DNA cross-linking agent 4,5',8-trimethyl psoralen. Nuclei isolated from actively growing Physarum were treated with trimethyl psoralen and irradiated with 360-nm light in order to form cross-links. The palindromic, extrachromosomal rDNA then was isolated, and the positions of cross-links were determined by electron microscopy of the DNA under totally denaturing conditions. The results indicate that the frequency of cross-linking, after correction for base sequence bias of the reaction, is up to sixfold higher in the transcribed regions than in the central or the terminal spacer regions. There is no detectable heterogeneity among the different rDNA molecules or between the halves of a single molecule. Cross-linked molecules invariably occur in a linear as opposed to a cruciform structure. The preferential cross-linking of the transcribed region is nearly eliminated in spherules, a dormant transcriptionally inactive form in the Physarum life cycle

Multiple-Site Trimethylation of Ribosomal Protein L11 by the PrmA Methyltransferase

Energy Technology Data Exchange (ETDEWEB)

Demirci,H.; Gregory, S.; Dahlberg, A.; Jogl, G.

2008-01-01

Ribosomal protein L11 is a universally conserved component of the large subunit, and plays a significant role during initiation, elongation, and termination of protein synthesis. In Escherichia coli, the lysine methyltransferase PrmA trimethylates the N-terminal a-amino group and the -amino groups of Lys3 and Lys39. Here, we report four PrmA-L11 complex structures in different orientations with respect to the PrmA active site. Two structures capture the L11 N-terminal a-amino group in the active site in a trimethylated postcatalytic state and in a dimethylated state with bound S-adenosyl-L-homocysteine. Two other structures show L11 in a catalytic orientation to modify Lys39 and in a noncatalytic orientation. The comparison of complex structures in different orientations with a minimal substrate recognition complex shows that the binding mode remains conserved in all L11 orientations, and that substrate orientation is brought about by the unusual interdomain flexibility of PrmA.

Structural and magnetic Properties of TbZn-substituted calcium barium M-type nano-structured hexa-ferrites

Energy Technology Data Exchange (ETDEWEB)

Khan, Hasan M. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Department of Electronics, University of York, York YO10 5DD (United Kingdom); Islam, M.U., E-mail: dr.misbahulislam@bzu.edu.pk [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Xu, Yongbing [Department of Electronics, University of York, York YO10 5DD (United Kingdom); Nanjing–York International Centre of Spintronics and Nano-Engineering, Nanjing University, Nanjing 210093 (China); Asif Iqbal, M. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); National University of Science and Technology, College of E and ME, Islamabad (Pakistan); Ali, Irshad [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan)

2014-03-15

Highlights: • Tb–Zn substituted Ca{sub 0.5}Ba{sub 0.5}Fe{sub 12}O{sub 19} samples exhibit single magnetoplumbite phase. • Lattice parameters a and c have increasing values. • Coercivity can be tuned at lower substitution level • Crystallites size was found in the range 18–25 nm by TEM and by Scherrer formula. • These hexa-ferrites are suitable for microwave devices and magnetic recording media. -- Abstract: Effect of TbZn substitution on the structural and magnetic properties of Ca{sub 0.5}Ba{sub 0.5−x}Tb{sub x}Zn{sub y}Fe{sub 12−y}O{sub 19}, (x = 0.00–0.10; y = 0.00–1.00) ferrites prepared by sol–gel auto combustion is reported. The synthesized samples were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Vibrating Sample magnetometery. The X-ray diffraction analysis confirmed single phase M-type hexa-ferrite structure. The lattice parameters were found to increase as TbZn contents increases, which is attributed to the ionic sizes of the implicated cations. The TbZn seems to be completely soluble in the lattice. The results of scanning electron microscopy and transmission electron microscopy shows that the grain size decreases with increase of TbZn substitution. The coercivity values (1277–2025 Oe) of all samples lies in the range of M-type hexa-ferrite and indicate that an increase of anisotropy was achieved by substitution of TbZn, while the size of nanoparticles was drastically reduced between 18 and 25 nm. The increased anisotropy and fine particle size are useful for many applications, such as improving signal noise ratio of recording devices.

The Meiotic Recombination Activator PRDM9 Trimethylates Both H3K36 and H3K4 at Recombination Hotspots In Vivo.

Science.gov (United States)

Powers, Natalie R; Parvanov, Emil D; Baker, Christopher L; Walker, Michael; Petkov, Petko M; Paigen, Kenneth

2016-06-01

In many mammals, including humans and mice, the zinc finger histone methyltransferase PRDM9 performs the first step in meiotic recombination by specifying the locations of hotspots, the sites of genetic recombination. PRDM9 binds to DNA at hotspots through its zinc finger domain and activates recombination by trimethylating histone H3K4 on adjacent nucleosomes through its PR/SET domain. Recently, the isolated PR/SET domain of PRDM9 was shown capable of also trimethylating H3K36 in vitro, raising the question of whether this reaction occurs in vivo during meiosis, and if so, what its function might be. Here, we show that full-length PRDM9 does trimethylate H3K36 in vivo in mouse spermatocytes. Levels of H3K4me3 and H3K36me3 are highly correlated at hotspots, but mutually exclusive elsewhere. In vitro, we find that although PRDM9 trimethylates H3K36 much more slowly than it does H3K4, PRDM9 is capable of placing both marks on the same histone molecules. In accord with these results, we also show that PRDM9 can trimethylate both K4 and K36 on the same nucleosomes in vivo, but the ratio of K4me3/K36me3 is much higher for the pair of nucleosomes adjacent to the PRDM9 binding site compared to the next pair further away. Importantly, H3K4me3/H3K36me3-double-positive nucleosomes occur only in regions of recombination: hotspots and the pseudoautosomal (PAR) region of the sex chromosomes. These double-positive nucleosomes are dramatically reduced when PRDM9 is absent, showing that this signature is PRDM9-dependent at hotspots; the residual double-positive nucleosomes most likely come from the PRDM9-independent PAR. These results, together with the fact that PRDM9 is the only known mammalian histone methyltransferase with both H3K4 and H3K36 trimethylation activity, suggest that trimethylation of H3K36 plays an important role in the recombination process. Given the known requirement of H3K36me3 for double strand break repair by homologous recombination in somatic cells, we

Ion-specific weak adsorption of salts and water/octanol transfer free energy of a model amphiphilic hexa-peptide

International Nuclear Information System (INIS)

Dejugnat, Ch.; Dufreche, J.F.; Zemb, Th.; Dejugnat, Ch.

2011-01-01

An amphiphilic hexa-peptide has been used as a model to quantify how specific ion effects induced by addition of four salts tune the hydrophilic/hydrophobic balance and induce temperature-dependant coacervate formation from aqueous solution. The hexa-peptide chosen is present as a dimer with low transfer energy from water to octanol. Taking sodium chloride as the reference state in the Hofmeister scale, we identify water activity effects and therefore measure the free energy of transfer from water to octanol and separately the free energy associated to the adsorption of chaotropic ions or the desorption of kosmotropic ions for the same amphiphilic peptide. These effects have the same order of magnitude: therefore, both energies of solvation as well as transfer into octanol strongly depend on the nature of the electrolytes used to formulate any buffer. Model peptides could be used on separation processes based on criteria linked to 'Hofmeister' but different from volume and valency. (authors)

Physical stability, centrifugation tests, and entrapment efficiency studies of carnauba wax-decyl oleate nanoparticles used for the dispersion of inorganic sunscreens in aqueous media.

Science.gov (United States)

Villalobos-Hernández, J R; Müller-Goymann, C C

2006-06-01

Aqueous nanoscale lipid dispersions consisting of carnauba wax-decyl oleate mixtures acting as carriers or accompanying vehicles for inorganic sunscreens such as barium sulfate, strontium carbonate, and titanium dioxide were prepared by high pressure homogenization. For the manufacture of these nanosuspensions, three pigment concentrations (%wt), namely 2, 4, and 6, and two carnauba wax-decyl oleate ratios, 1:1 and 2:1, were used, being some of these combinations chosen for stability studies. Six-month physical stability tests at 4, 20, and 40 degrees C selecting the mean particle size and the polydispersity index of the nanosuspensions as reference parameters were performed. Centrifugation tests of the nanosuspensions assessed by transmission electron microscopy and by the determination of the content of pigments and carnauba wax in the separated fractions were done. The mean particle sizes and the polydispersity indices of the nanosuspensions were not altered after six-month storages at 20 and at 40 degrees C. However, the storage of those at 4 degrees C considerably increased the particle size and polydispersity of the systems, particularly when wax-oil ratios (2:1) were used for the entrapment of the pigments. Transmission electron micrographs of centrifuged samples denoted the presence of three major fractions showing the different types of particles integrated into the nanosuspensions. Furthermore, it was observed that not all the carnauba wax participated in the entrapment of the pigment. Regarding the amount of pigment being encapsulated or bonded by the wax-oil matrices, entrapment efficiencies higher than 85.52% were reported.

Two novel exonic point mutations in HEXA identified in a juvenile Tay-Sachs patient: role of alternative splicing and nonsense-mediated mRNA decay.

Science.gov (United States)

Levit, A; Nutman, D; Osher, E; Kamhi, E; Navon, R

2010-06-01

We have identified three mutations in the beta-hexoseaminidase A (HEXA) gene in a juvenile Tay-Sachs disease (TSD) patient, which exhibited a reduced level of HEXA mRNA. Two mutations are novel, c.814G>A (p.Gly272Arg) and c.1305C>T (p.=), located in exon 8 and in exon 11, respectively. The third mutation, c.1195A>G (p.Asn399Asp) in exon 11, has been previously characterized as a common polymorphism in African-Americans. Hex A activity measured in TSD Glial cells, transfected with HEXA cDNA constructs bearing these mutations, was unaltered from the activity level measured in normal HEXA cDNA. Analysis of RT-PCR products revealed three aberrant transcripts in the patient, one where exon 8 was absent, one where exon 11 was absent and a third lacking both exons 10 and 11. All three novel transcripts contain frameshifts resulting in premature termination codons (PTCs). Transfection of mini-gene constructs carrying the c.814G>A and c.1305C>T mutations proved that the two mutations result in exon skipping. mRNAs that harbor a PTC are detected and degraded by the nonsense-mediated mRNA decay (NMD) pathway to prevent synthesis of abnormal proteins. However, although NMD is functional in the patient's fibroblasts, aberrant transcripts are still present. We suggest that the level of correctly spliced transcripts as well as the efficiency in which NMD degrade the PTC-containing transcripts, apparently plays an important role in the phenotype severity of the unique patient and thus should be considered as a potential target for drug therapy.

Identification of novel mutations in HEXA gene in children affected with Tay Sachs disease from India.

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Mehul Mistri

Full Text Available Tay Sachs disease (TSD is a neurodegenerative disorder due to β-hexosaminidase A deficiency caused by mutations in the HEXA gene. The mutations leading to Tay Sachs disease in India are yet unknown. We aimed to determine mutations leading to TSD in India by complete sequencing of the HEXA gene. The clinical inclusion criteria included neuroregression, seizures, exaggerated startle reflex, macrocephaly, cherry red spot on fundus examination and spasticity. Neuroimaging criteria included thalamic hyperdensities on CT scan/T1W images of MRI of the brain. Biochemical criteria included deficiency of hexosaminidase A (less than 2% of total hexosaminidase activity for infantile patients. Total leukocyte hexosaminidase activity was assayed by 4-methylumbelliferyl-N-acetyl-β-D-glucosamine lysis and hexosaminidase A activity was assayed by heat inactivation method and 4-methylumbelliferyl-N-acetyl-β-D-glucosamine-6-sulphate lysis method. The exons and exon-intron boundaries of the HEXA gene were bidirectionally sequenced using an automated sequencer. Mutations were confirmed in parents and looked up in public databases. In silico analysis for mutations was carried out using SIFT, Polyphen2, MutationT@ster and Accelrys Discovery Studio softwares. Fifteen families were included in the study. We identified six novel missense mutations, c.340 G>A (p.E114K, c.964 G>A (p.D322N, c.964 G>T (p.D322Y, c.1178C>G (p.R393P and c.1385A>T (p.E462V, c.1432 G>A (p.G478R and two previously reported mutations. c.1277_1278insTATC and c.508C>T (p.R170W. The mutation p.E462V was found in six unrelated families from Gujarat indicating a founder effect. A previously known splice site mutation c.805+1 G>C and another intronic mutation c.672+30 T>G of unknown significance were also identified. Mutations could not be identified in one family. We conclude that TSD patients from Gujarat should be screened for the common mutation p.E462V.

Identification of novel mutations in HEXA gene in children affected with Tay Sachs disease from India.

Science.gov (United States)

Mistri, Mehul; Tamhankar, Parag M; Sheth, Frenny; Sanghavi, Daksha; Kondurkar, Pratima; Patil, Swapnil; Idicula-Thomas, Susan; Gupta, Sarita; Sheth, Jayesh

2012-01-01

Tay Sachs disease (TSD) is a neurodegenerative disorder due to β-hexosaminidase A deficiency caused by mutations in the HEXA gene. The mutations leading to Tay Sachs disease in India are yet unknown. We aimed to determine mutations leading to TSD in India by complete sequencing of the HEXA gene. The clinical inclusion criteria included neuroregression, seizures, exaggerated startle reflex, macrocephaly, cherry red spot on fundus examination and spasticity. Neuroimaging criteria included thalamic hyperdensities on CT scan/T1W images of MRI of the brain. Biochemical criteria included deficiency of hexosaminidase A (less than 2% of total hexosaminidase activity for infantile patients). Total leukocyte hexosaminidase activity was assayed by 4-methylumbelliferyl-N-acetyl-β-D-glucosamine lysis and hexosaminidase A activity was assayed by heat inactivation method and 4-methylumbelliferyl-N-acetyl-β-D-glucosamine-6-sulphate lysis method. The exons and exon-intron boundaries of the HEXA gene were bidirectionally sequenced using an automated sequencer. Mutations were confirmed in parents and looked up in public databases. In silico analysis for mutations was carried out using SIFT, Polyphen2, MutationT@ster and Accelrys Discovery Studio softwares. Fifteen families were included in the study. We identified six novel missense mutations, c.340 G>A (p.E114K), c.964 G>A (p.D322N), c.964 G>T (p.D322Y), c.1178C>G (p.R393P) and c.1385A>T (p.E462V), c.1432 G>A (p.G478R) and two previously reported mutations. c.1277_1278insTATC and c.508C>T (p.R170W). The mutation p.E462V was found in six unrelated families from Gujarat indicating a founder effect. A previously known splice site mutation c.805+1 G>C and another intronic mutation c.672+30 T>G of unknown significance were also identified. Mutations could not be identified in one family. We conclude that TSD patients from Gujarat should be screened for the common mutation p.E462V.

Chemical degradation of trimethyl phosphate as surrogate for organo-phosporus pesticides on nanostructured metal oxides

Czech Academy of Sciences Publication Activity Database

Štengl, Václav; Henych, Jiří; Matys Grygar, Tomáš; Pérez, Raul

2015-01-01

Roč. 61, JAN (2015), s. 259-269 ISSN 0025-5408 R&D Projects: GA ČR(CZ) GAP106/12/1116 Institutional support: RVO:61388980 Keywords : Nanostructured oxides * Stoichiometric degradation * Trimethyl phosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 2.435, year: 2015

Tay-Sachs disease in an Arab family due to c.78G>A HEXA nonsense mutation encoding a p.W26X early truncation enzyme peptide.

Science.gov (United States)

Haghighi, Alireza; Masri, Amira; Kornreich, Ruth; Desnick, Robert J

2011-12-01

Tay-Sachs disease (TSD), a pan-ethnic, autosomal recessive, neurodegenerative, lysosomal disease, results from deficient β-hexosaminidase A activity due to β-hexosaminidase α-subunit (HEXA) mutations. Prenatal/premarital carrier screening programs in the Ashkenazi Jewish community have markedly reduced disease occurrence. We report the first Jordanian Arab TSD patient diagnosed by deficient β-hexosaminidase A activity. HEXA mutation analysis revealed homozygosity for a nonsense mutation, c.78G>A (p.W26X). Previously reported in Arab patients, this mutation is a candidate for TSD screening in Arab populations. Copyright © 2011 Elsevier Inc. All rights reserved.

Photochemical synthesis of ultrafine organosilicon particles from trimethyl(2-propynyloxy)silane and carbon disulfide

Czech Academy of Sciences Publication Activity Database

Morita, H.; Nozawa, R.; Bastl, Zdeněk; Šubrt, Jan; Pola, Josef

2006-01-01

Roč. 179, 1-2 (2006), s. 142-148 ISSN 1010-6030 Grant - others:MEXT(JP) 767/15085203 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40320502; CEZ:AV0Z40720504 Keywords : ultrafine particles * photo-polymerization * trimethyl(2-propynyloxy)silane * carbon disulfide Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.098, year: 2006

Loss of acetylation at Lys16 and trimethylation at Lys20 of histone H4 is a common hallmark of human cancer.

Science.gov (United States)

Fraga, Mario F; Ballestar, Esteban; Villar-Garea, Ana; Boix-Chornet, Manuel; Espada, Jesus; Schotta, Gunnar; Bonaldi, Tiziana; Haydon, Claire; Ropero, Santiago; Petrie, Kevin; Iyer, N Gopalakrishna; Pérez-Rosado, Alberto; Calvo, Enrique; Lopez, Juan A; Cano, Amparo; Calasanz, Maria J; Colomer, Dolors; Piris, Miguel Angel; Ahn, Natalie; Imhof, Axel; Caldas, Carlos; Jenuwein, Thomas; Esteller, Manel

2005-04-01

CpG island hypermethylation and global genomic hypomethylation are common epigenetic features of cancer cells. Less attention has been focused on histone modifications in cancer cells. We characterized post-translational modifications to histone H4 in a comprehensive panel of normal tissues, cancer cell lines and primary tumors. Using immunodetection, high-performance capillary electrophoresis and mass spectrometry, we found that cancer cells had a loss of monoacetylated and trimethylated forms of histone H4. These changes appeared early and accumulated during the tumorigenic process, as we showed in a mouse model of multistage skin carcinogenesis. The losses occurred predominantly at the acetylated Lys16 and trimethylated Lys20 residues of histone H4 and were associated with the hypomethylation of DNA repetitive sequences, a well-known characteristic of cancer cells. Our data suggest that the global loss of monoacetylation and trimethylation of histone H4 is a common hallmark of human tumor cells.

Next-generation DNA sequencing of HEXA: a step in the right direction for carrier screening

Science.gov (United States)

Hoffman, Jodi D; Greger, Valerie; Strovel, Erin T; Blitzer, Miriam G; Umbarger, Mark A; Kennedy, Caleb; Bishop, Brian; Saunders, Patrick; Porreca, Gregory J; Schienda, Jaclyn; Davie, Jocelyn; Hallam, Stephanie; Towne, Charles

2013-01-01

Tay-Sachs disease (TSD) is the prototype for ethnic-based carrier screening, with a carrier rate of ∼1/27 in Ashkenazi Jews and French Canadians. HexA enzyme analysis is the current gold standard for TSD carrier screening (detection rate ∼98%), but has technical limitations. We compared DNA analysis by next-generation DNA sequencing (NGS) plus an assay for the 7.6 kb deletion to enzyme analysis for TSD carrier screening using 74 samples collected from participants at a TSD family conference. Fifty-one of 74 participants had positive enzyme results (46 carriers, five late-onset Tay-Sachs [LOTS]), 16 had negative, and seven had inconclusive results. NGS + 7.6 kb del screening of HEXA found a pathogenic mutation, pseudoallele, or variant of unknown significance (VUS) in 100% of the enzyme-positive or obligate carrier/enzyme-inconclusive samples. NGS detected the B1 allele in two enzyme-negative obligate carriers. Our data indicate that NGS can be used as a TSD clinical carrier screening tool. We demonstrate that NGS can be superior in detecting TSD carriers compared to traditional enzyme and genotyping methodologies, which are limited by false-positive and false-negative results and ethnically focused, limited mutation panels, respectively, but is not ready for sole use due to lack of information regarding some VUS. PMID:24498621

Attainment of barium hexa ferrite nanoparticles by a Pechini method

International Nuclear Information System (INIS)

Galvao, Sheila B.; Timoteo, Flavio Junior J.; Machado, Tercio G.; Souto, Kesia K.O.; Floreoto, Neide T.; Paskocimas, Carlos A.

2009-01-01

The barium hexa ferrites (BaFe 12 O 19 ) are used as a compound of materials applied in electronic devices, as medical devices, satellites, dada servers systems, wireless systems and others. The general properties are strongly related to the microstructure and morphology, and the particles size decrease results in advantages to the majority applications, mainly the high-tech thumbnail devices. These magnetic ceramic materials, with perovskite structure, are traditionally prepared my conventional oxide mixture synthesis. In this work was studied the nanoparticle synthesis of BaFe 12 O 19 by the precursors polymeric method (Pechini), using as precursors the barium carbonate and the iron nitrate, under different thermal treatment conditions. The samples were characterized by XRD, Raman spectroscopy, SEM, BET, DTA and TGA. The results presented the attainment of a monophasic powder with particles size around 100 nm. (author)

Fragrance material review on 1-(3,5,6-trimethyl-3-cyclohexen-1-yl)ethan-1-one.

Science.gov (United States)

Scognamiglio, J; Letizia, C S; Api, A M

2013-12-01

A toxicologic and dermatologic review of 1-(3,5,6-trimethyl-3-cyclohexen-1-yl)ethan-1-one when used as a fragrance ingredient is presented. 1-(3,5,6-Trimethyl-3-cyclohexen-1-yl)ethan-1-one is a member of the fragrance structural group Alkyl Cyclic Ketones. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 1-(3,5,6-trimethyl-3-cyclohexen-1-yl)ethan-1-one were evaluated then summarized and includes physical properties, skin irritation, and skin sensitization data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013. A Toxicologic and Dermatologic Assessment of Alkyl Cyclic Ketones When Used as Fragrance Ingredients (submitted for publication)) for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. Copyright © 2013 Elsevier Ltd. All rights reserved.

Next-generation DNA sequencing of HEXA: a step in the right direction for carrier screening

OpenAIRE

Hoffman, Jodi D; Greger, Valerie; Strovel, Erin T; Blitzer, Miriam G; Umbarger, Mark A; Kennedy, Caleb; Bishop, Brian; Saunders, Patrick; Porreca, Gregory J; Schienda, Jaclyn; Davie, Jocelyn; Hallam, Stephanie; Towne, Charles

2013-01-01

Tay-Sachs disease (TSD) is the prototype for ethnic-based carrier screening, with a carrier rate of ∼1/27 in Ashkenazi Jews and French Canadians. HexA enzyme analysis is the current gold standard for TSD carrier screening (detection rate ∼98%), but has technical limitations. We compared DNA analysis by next-generation DNA sequencing (NGS) plus an assay for the 7.6 kb deletion to enzyme analysis for TSD carrier screening using 74 samples collected from participants at a TSD family conference. ...

The Effect Of Coupling Agent On Composite Magnet Characteristic Based On Hexa ferrite (Sr M/Ba M) With Polyester And Epoxy Binder

International Nuclear Information System (INIS)

Sudirman; Ridwan; Mujamilah; Karo Karo, Aloma; Handayani, Ari; Rukihati

2004-01-01

Magnetic composites are mixtures of hexa ferrite powder and non magnetic materials such as polymers as binders. These composites have been investigated because they are light, elastic, and cheap. In this study thermoset polymer (epoxy and polyester) were used as binders. Inside study of coupling agent added effect on mechanical properties, hardness and microstructure. The composites were prepared by mixture thermoset polymer epoxy or polyester with hexa ferrite powder Sr M (SrFe 12 O 19 ) or Ba M (BaFe 12 O 19 ) with volume fraction of 40,50 and 60 % v/v, coupling agent of the Tetra Isopropyl Titanate in the amount of 5 ml or 10 ml are added before mix turing of the thermoset polymer epoxy or polyester with hexa ferrite powder. The resulting composite were characterized mechanically (tensile strength), hardness and microstructure test. The results showed that the tensile strength and hardness of the composite magnet were increased by increasing the composition of magnetic powder, either Sr M or Ba M, it caused by microstructure of particle Sr M magnetic powder 1.6 μm in the form splinter, where as the Ba M magnetic powder 1,2 μm in nodular form. Thermoset polymer epoxy as binder have tensile strength and hardness is bigger than composite magnet based on polyester, either Sr M or Ba M. The addition of coupling agent is very influenced on the tensile strength and hardness composite magnet, the more coupling magnet addition causes the more tensile strength and hardness of the composite magnet

μ-Hexa-thio-metadiphosphato-bis-[(1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-κ(6) O)rubidium] aceto-nitrile disolvate.

Science.gov (United States)

Gjikaj, Mimoza; Pook, Niels-Patrick; Qarri, Flora

2013-12-01

The asymmetric unit of the title compound, [Rb2(P2S6)(C12H24O6)2]·2CH3CN, contains one half of an [Rb(18-crown-6)2]2[P2S6] unit and one aceto-nitrile solvent mol-ecule. The [Rb(18-crown-6)]2[P2S6] unit is completed by inversion symmetry. Its Rb(+) ion is situated near the centre of the macrocyclic cavity, but is displaced by 0.8972 (1) Å from the O atoms of the crown in the direction of the [P2S6](2-) moiety. The overall coordination number of the cation is eight, defined by the six crown ether O atoms and by two terminal S atoms of the [P2S6](2-) anion. The hexa-thio-metadiphosphate anion is built up from two tetra-hedral PS4 units joined together by a common edge. The crystal structure is characterized by alternating layers of [Rb(18-crown-6)]2[P2S6] and aceto-nitrile solvent mol-ecules stacked along [010].

Fragrance material review on 1-(2,6,6-trimethyl-2-cyclohexen-1-yl)pent-1-en-3-one.

Science.gov (United States)

Scognamiglio, J; Letizia, C S; Api, A M

2013-12-01

A toxicologic and dermatologic review of 1-(2,6,6-trimethyl-2-cyclohexen-1-yl)pent-1-en-3-one when used as a fragrance ingredient is presented. 1-(2,6,6-Trimethyl-2-cyclohexen-1-yl)pent-1-en-3-one is a member of the fragrance structural group Alkyl Cyclic Ketones. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 1-(2,6,6-trimethyl-2-cyclohexen-1-yl)pent-1-en-3-one were evaluated then summarized and includes physical properties data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013. A Toxicologic and Dermatologic Assessment of Alkyl Cyclic Ketones when used as fragrance ingredients. Submitted for publication) for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. Copyright © 2013 Elsevier Ltd. All rights reserved.

40 CFR 721.7270 - 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl derivs., chloride.

Science.gov (United States)

2010-07-01

...-trimethyl-N-soya acyl derivs., chloride. 721.7270 Section 721.7270 Protection of Environment ENVIRONMENTAL...-soya acyl derivs., chloride. (a) Chemical substance and significant new uses subject to reporting. (1...., chloride (PMN P-01-646; CAS No. 391232-99-8) is subject to reporting under this section for the significant...

Synthetic studies with Pinus elliottiis rosin derivatives. Oxidation of maleopimaric anhydride methyl ester and trimethyl fumaropimarate

Directory of Open Access Journals (Sweden)

Hess Sonia C.

2000-01-01

Full Text Available Ozonolysis of maleopimaric anhydride methyl ester in the presence of tetracyanoethylene led to an epoxide and an ozonide. Ozonolysis of the trimethyl fumaropimarate, followed by treatment with Me2S, led to an epoxide, a diene, a keto-acid and an allylic oxidation product. Some of the compounds obtained were active against Staphylococcus aureus, Bacillus subtilis and Micrococcus luteus.

Materials Synthesis Of Barium Hexa ferrite Used Local Natural Resources

International Nuclear Information System (INIS)

Ridwan; Sulungbudi, Grace Tj.; Mujamilah

2003-01-01

The magnetic materials of barium hexa ferrites, Ba O.6Fe 2 O 3 successfully synthesized by powder metallurgy method used local natural resources from materials waste of steel fabrication (HSM, CRM), waste of polymer fabrication (LK) as well as iron sands (PBA). These waste as well as iron sands were the main resources of iron oxide, Fe 2 O 3 . The barium oxide used in this experiments are from BaCO 3 product of Merck, and BaCO 4 which is commercially available in the market as barite. Phase identification by x-ray diffraction technique show the synthesized magnetic materials are agreed with the available commercial product, (SUMI). The energy product maximum (BH) max measured by vibrating sample magnetometer (VSM) for the samples used HSM-, CRM- and BaCO 3 as basic materials are 1.141 MGOe and 1.136 MGOe while SUMI is 1.142 MGOe. However for the samples made from LK-, PBA- used of BaCO 3 or CRM- with barite, the energy product maximum (BH) max are relatively lower than commercial product

Targeted disruption of the Hexa gene results in mice with biochemical and pathologic features of Tay-Sachs disease

Energy Technology Data Exchange (ETDEWEB)

Proia, R.L.; Yamanaka, S.; Johnson, M.D. [and others

1994-09-01

Tay-Sachs disease, the prototype of the G{sub M2} gangliosidoses, is a catastrophic neurodegenerative disorder of infancy. The disease is caused by mutations in the HEXA gene resulting in an absence of the lysosomal enzyme, {beta}-hexosaminidase A. As consequence of the enzyme deficiency, G{sub M2} ganglioside accumulates progressively, beginning early in fetal life, to excessive amounts in the central nervous system (CNS). Rapid mental and motor deterioration starting in the first year of life leads to death by 2 to 4 years of age. Through the targeted disruption of the Hexa gene in embryonic stem cells, we have produced mice with biochemical and neuropathologic features of Tay-Sachs disease. The mutant mice exhibited less than 1% of normal {beta}-hexosaminidase A activity and accumulated G{sub M2} ganglioside in their CNS in an age-dependent manner. The accumulated ganglioside was stored in neurons as membranous cytoplasmic bodies characteristically found in the neurons of Tay-Sachs disease patients. At three to five months of age the mutant mice showed no apparent defects in motor or memory function. These {beta}-hexosaminidase A deficient mice should be useful for devising strategies to introduce functional enzymes and genes into the CNS. This model may also be valuable for studying the biochemical and pathologic changes occurring during the course of the disease.

In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax-decyl oleate nanoparticles.

Science.gov (United States)

Villalobos-Hernández, J R; Müller-Goymann, C C

2007-01-01

This paper describes the in vitro photoprotection in the UV-A range, i.e. 320-400 nm obtained by the use of carnauba wax-decyl oleate nanoparticles either as encapsulation systems or as accompanying vehicles for inorganic sunscreens such as barium sulfate, strontium carbonate and titanium dioxide. Lipid-free inorganic sunscreen nanosuspensions, inorganic sunscreen-free wax-oil nanoparticle suspensions and wax-oil nanoparticle suspensions containing inorganic sunscreens dispersed either in their oil phase or their aqueous phase were prepared by high pressure homogenization. The in vitro erythemal UV-A protection factors (EUV-A PFs) of the nanosuspensions were calculated by means of a sun protection analyzer. EUV-A PFs being no higher than 4 were obtained by the encapsulation of barium sulfate and strontium carbonate, meanwhile by the distribution of titanium dioxide in presence of wax-oil nanoparticles, the EUV-A PFs varied between 2 and 19. The increase in the EUV-A PFs of the titanium dioxide obtained by the use of wax-oil nanoparticles demonstrated a better performance of the sun protection properties of this pigment in the UV-A region.

Profiling of histone H3 lysine 9 trimethylation levels predicts transcription factor activity and survival in acute myeloid leukemia

DEFF Research Database (Denmark)

Müller-Tidow, Carsten; Klein, Hans-Ulrich; Hascher, Antje

2010-01-01

Acute Myeloid Leukemia (AML) is commonly associated with alterations in transcription factors due to altered expression or gene mutations. These changes might induce leukemia- specific patterns of histone modifications. We used ChIP-Chip to analyze histone H3 Lysine 9 trimethylation (H3K9me3) pat...

Generation of HEXA-deficient hiPSCs from fibroblasts of a Tay-Sachs disease patient

Directory of Open Access Journals (Sweden)

Zhong Liu

2016-09-01

Full Text Available Human iPSC line TSD-01-hiPSC was generated from fibroblasts of a patient with infantile Tay-Sachs disease (TSD. The patient is compound heterozygous at the HEXA gene by carrying a 1278insTATC allele and an IVS12+1G>C allele. STEMCCA lentivirus, which expresses OCT4, SOX2, KLF4, and c-MYC from a polycistronic transcript, were used for reprogramming. TSD-01-hiPSC express pluripotency markers such as OCT4, SOX2, NANOG, Tra-1-60, and alkaline phosphatase, and can differentiate into tissues from all the three embryonic germ layers. This TSD patient-derived hiPSC line may serve as a valuable in vitro tool for disease modeling and drug test.

Regulatory network controlling extracellular proteins in Erwinia carotovora subsp. carotovora: FlhDC, the master regulator of flagellar genes, activates rsmB regulatory RNA production by affecting gacA and hexA (lrhA) expression.

Science.gov (United States)

Cui, Yaya; Chatterjee, Asita; Yang, Hailian; Chatterjee, Arun K

2008-07-01

Erwinia carotovora subsp. carotovora produces an array of extracellular proteins (i.e., exoproteins), including plant cell wall-degrading enzymes and Harpin, an effector responsible for eliciting hypersensitive reaction. Exoprotein genes are coregulated by the quorum-sensing signal, N-acyl homoserine lactone, plant signals, an assortment of transcriptional factors/regulators (GacS/A, ExpR1, ExpR2, KdgR, RpoS, HexA, and RsmC) and posttranscriptional regulators (RsmA, rsmB RNA). rsmB RNA production is positively regulated by GacS/A, a two-component system, and negatively regulated by HexA (PecT in Erwinia chrysanthemi; LrhA [LysR homolog A] in Escherichia coli) and RsmC, a putative transcriptional adaptor. While free RsmA, an RNA-binding protein, promotes decay of mRNAs of exoprotein genes, binding of RsmA with rsmB RNA neutralizes the RsmA effect. In the course of studies of GacA regulation, we discovered that a locus bearing strong homology to the flhDC operon of E. coli also controls extracellular enzyme production. A transposon insertion FlhDC(-) mutant produces very low levels of pectate lyase, polygalacturonase, cellulase, protease, and E. carotovora subsp. carotovora Harpin (Harpin(Ecc)) and is severely attenuated in its plant virulence. The production of these exoproteins is restored in the mutant carrying an FlhDC(+) plasmid. Sequence analysis and transcript assays disclosed that the flhD operon of E. carotovora subsp. carotovora, like those of other enterobacteria, consists of flhD and flhC. Complementation analysis revealed that the regulatory effect requires functions of both flhD and flhC products. The data presented here show that FlhDC positively regulates gacA, rsmC, and fliA and negatively regulates hexA (lrhA). Evidence shows that FlhDC controls extracellular protein production through cumulative effects on hexA and gacA. Reduced levels of GacA and elevated levels of HexA in the FlhDC(-) mutant are responsible for the inhibition of rsmB RNA

Regulatory Network Controlling Extracellular Proteins in Erwinia carotovora subsp. carotovora: FlhDC, the Master Regulator of Flagellar Genes, Activates rsmB Regulatory RNA Production by Affecting gacA and hexA (lrhA) Expression▿

Science.gov (United States)

Cui, Yaya; Chatterjee, Asita; Yang, Hailian; Chatterjee, Arun K.

2008-01-01

Erwinia carotovora subsp. carotovora produces an array of extracellular proteins (i.e., exoproteins), including plant cell wall-degrading enzymes and Harpin, an effector responsible for eliciting hypersensitive reaction. Exoprotein genes are coregulated by the quorum-sensing signal, N-acyl homoserine lactone, plant signals, an assortment of transcriptional factors/regulators (GacS/A, ExpR1, ExpR2, KdgR, RpoS, HexA, and RsmC) and posttranscriptional regulators (RsmA, rsmB RNA). rsmB RNA production is positively regulated by GacS/A, a two-component system, and negatively regulated by HexA (PecT in Erwinia chrysanthemi; LrhA [LysR homolog A] in Escherichia coli) and RsmC, a putative transcriptional adaptor. While free RsmA, an RNA-binding protein, promotes decay of mRNAs of exoprotein genes, binding of RsmA with rsmB RNA neutralizes the RsmA effect. In the course of studies of GacA regulation, we discovered that a locus bearing strong homology to the flhDC operon of E. coli also controls extracellular enzyme production. A transposon insertion FlhDC− mutant produces very low levels of pectate lyase, polygalacturonase, cellulase, protease, and E. carotovora subsp. carotovora Harpin (HarpinEcc) and is severely attenuated in its plant virulence. The production of these exoproteins is restored in the mutant carrying an FlhDC+ plasmid. Sequence analysis and transcript assays disclosed that the flhD operon of E. carotovora subsp. carotovora, like those of other enterobacteria, consists of flhD and flhC. Complementation analysis revealed that the regulatory effect requires functions of both flhD and flhC products. The data presented here show that FlhDC positively regulates gacA, rsmC, and fliA and negatively regulates hexA (lrhA). Evidence shows that FlhDC controls extracellular protein production through cumulative effects on hexA and gacA. Reduced levels of GacA and elevated levels of HexA in the FlhDC− mutant are responsible for the inhibition of rsmB RNA production

Exploring advantages/disadvantages and improvements in overcoming gene delivery barriers of amino acid modified trimethylated chitosan.

Science.gov (United States)

Zheng, Hao; Tang, Cui; Yin, Chunhua

2015-06-01

Present study aimed at exploring advantages/disadvantages of amino acid modified trimethylated chitosan in conquering multiple gene delivery obstacles and thus providing comprehensive understandings for improved transfection efficiency. Arginine, cysteine, and histidine modified trimethyl chitosan were synthesized and employed to self-assemble with plasmid DNA (pDNA) to form nanocomplexes, namely TRNC, TCNC, and THNC, respectively. They were assessed by structural stability, cellular uptake, endosomal escape, release behavior, nuclear localization, and in vitro and in vivo transfection efficiencies. Besides, sodium tripolyphosphate (TPP) was added into TRNC to compromise certain disadvantageous attributes for pDNA delivery. Optimal endosomal escape ability failed to bring in satisfactory transfection efficiency of THNC due to drawbacks in structural stability, cellular uptake, pDNA liberation, and nuclear distribution. TCNC evoked the most potent gene expression owing to multiple advantages including sufficient stability, preferable uptake, efficient pDNA release, and high nucleic accumulation. Undesirable stability and insufficient pDNA release adversely affected TRNC-mediated gene transfer. However, incorporation of TPP could improve such disadvantages and consequently resulted in enhanced transfection efficiencies. Coordination of multiple contributing effects to conquer all delivery obstacles was necessitated for improved transfection efficiency, which would provide insights into rational design of gene delivery vehicles.

Line-on-line organic-organic heteroepitaxy of quaterrylene on hexa-peri-hexabenzocoronene on Au(111).

Science.gov (United States)

Kasemann, Daniel; Wagner, Christian; Forker, Roman; Dienel, Thomas; Müllen, Klaus; Fritz, Torsten

2009-11-03

In a recent paper, we discussed the optical properties of a heterostructure consisting of a highly ordered monolayer of quaterrylene (QT), electronically decoupled from the gold substrate by a predeposited epitaxial monolayer of hexa-peri-hexabenzocoronene (HBC). Here we now present the detailed structural investigation of this organic double-layer system. We show that the structure of the heterosystem can be identified as line-on-line coincidence (lol), a new type of epitaxy discovered by us previously for the system 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on HBC on highly oriented pyrolytic graphite (HOPG). Additionally, we provide evidence on the basis of advanced potential energy calculations that indeed energetic gain drives this lol growth mode.

Three-component synthesis of dialkyl 2-(alkylimino-methylene)3- (2,2,5-trimethyl-4,6-dioxo-1,3-dioxan-5-yl)-succinates.

Science.gov (United States)

Yavari, Issa; Zare, Hasan; Mohtat, Bita

2006-05-01

The adduct produced in the reaction between alkyl isocyanides and dialkyl acetylenedicarboxylates was trapped by 2,2,5-trimethyl-1,3-dioxane-4,6-dione (methyl Meldrum's acid), to afford highly functionalized ketenimines in good yields.

Exfoliation of graphite into graphene in polar solvents mediated by amphiphilic hexa-peri-hexabenzocoronene.

Science.gov (United States)

Kabe, Ryota; Feng, Xinliang; Adachi, Chihaya; Müllen, Klaus

2014-11-01

A water-soluble surfactant consisting of hexa-peri-hexabenzocoronene (HBC) as hydrophobic aromatic core and hydrophilic carboxy substituents was synthesized. It exhibited a self-assembled nanofiber structure in the solid state. Profiting from the π interactions between the large aromatic core of HBC and graphene, the surfactant mediated the exfoliation of graphite into graphene in polar solvents, which was further stabilized by the bulky hydrophilic carboxylic groups. A graphene dispersion with a concentration as high as 1.1 mg L(-1) containing 2-6 multilayer nanosheets was obtained. The lateral size of the graphene sheets was in the range of 100-500 nm based on atomic force microscope (AFM) and transmission electron microscope (TEM) measurements. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Generation of HEXA-deficient hiPSCs from fibroblasts of a Tay-Sachs disease patient.

Science.gov (United States)

Liu, Zhong; Zhao, Rui

2016-09-01

Human iPSC line TSD-01-hiPSC was generated from fibroblasts of a patient with infantile Tay-Sachs disease (TSD). The patient is compound heterozygous at the HEXA gene by carrying a 1278insTATC allele and an IVS12+1G>C allele. STEMCCA lentivirus, which expresses OCT4, SOX2, KLF4, and c-MYC from a polycistronic transcript, were used for reprogramming. TSD-01-hiPSC express pluripotency markers such as OCT4, SOX2, NANOG, Tra-1-60, and alkaline phosphatase, and can differentiate into tissues from all the three embryonic germ layers. This TSD patient-derived hiPSC line may serve as a valuable in vitro tool for disease modeling and drug test. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Fragrance material review on 3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-3-en-2-one.

Science.gov (United States)

Scognamiglio, J; Letizia, C S; Api, A M

2013-12-01

A toxicologic and dermatologic review of 3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-3-en-2-one when used as a fragrance ingredient is presented. 3-Methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-3-en-2-one is a member of the fragrance structural group Alkyl Cyclic Ketones. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-3-en-2-one were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, sensitization, phototoxicity, photoallergy, and genotoxicity data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013. A Toxicologic and Dermatologic Assessment of Alkyl Cyclic Ketones when used as fragrance ingredients. Submitted for publication) for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development and Evaluation of Diclofenac Sodium Loaded-N-Trimethyl Chitosan Nanoparticles for Ophthalmic Use.

Science.gov (United States)

Asasutjarit, Rathapon; Theerachayanan, Thitaree; Kewsuwan, Prartana; Veeranodha, Sukitaya; Fuongfuchat, Asira; Ritthidej, Garnpimol C

2015-10-01

The ophthalmic preparation of diclofenac sodium (DC) for relieving ocular inflammation is presently available in the market only as an eye drop solution. Due to its low occular bioavailability, it requires frequent application leading to low patients' compliance and quality of life. This study was conducted to develop formulations of DC loaded-N-trimethyl chitosan nanoparticles (DC-TMCNs) for ophthalmic use to improve ocular biavailabiltiy of DC. DC-TMCNs varied in formulation compositions were prepared using ionic gelation technique and evaluated for their physicochemical properties, drug release, eye irritation potential, and ophthalmic absorption of diclofenac sodium. N-Trimethyl chitosan (TMC) with a 49.8% degree of quaternization was synthesized and used for DC-TMCNs production. The obtained DC-TMCNs had particle size in a range of 130-190 nm with zeta potential values of +4 to +9 mV and drug entrapment efficiencies of more than 70% depending on the content of TMC and sodium tripolyphosphate (TPP). The optimized DC-TMCNs formulation contained TMC, DC, and TPP at a weight ratio of TMC/DC/TPP = 3:1:1. Their lyophilized product reconstituted with phosphate buffer solution pH 5.5 possessed a drug release pattern that fitted within the zero-order model. The eye irritation tests showed that DC-TMCNs were safe for ophthalmic use. The in vivo ophthalmic drug absorption study performed on rabbits indicated that DC-TMCNs could improve ophthalmic bioavailability of DC. Results of this study suggested that DC-TMCNs had potential for use as an alternative to conventional DC eye drops for ophthalmic inflammation treatment.

Mechanical Properties Analysis Of Composite Magnetic Base On hexa ferrite And Polyester Or Epoxy Matrix With Silane Additive Addition

International Nuclear Information System (INIS)

Sudirman; Ridwan; Mujamilah; K K, Aloma; Rembulan, Marisa; Fitriyanti

2003-01-01

Application of composite magnetic especially hexa ferrite magnet for industry and home industry in Indonesia has been used. Research purposes were making composite magnetic by mixing hexa ferrite powder with polyester or epoxy and studying the effect of coupling agent 3-aminopropyltriethoxysilane (3-APE) addition on mechanical properties of composite magnetic. The coupling agent may increase bonding properties between magnetic powder and matrix polymer, so that tensile strength of magnetic composite will increase without decreasing the magnetic properties. Magnetic powder (SrM or BaM) wich be coated by coupling agent were added to matrix polyester and mekpo or epoxy and versamid, mixed until homogen then pressing into to the dumbbell form molding. For epoxy matrix, pressing was done in hot press at 70 deg. C and 150 kg/cm 2 following by cooling in cold press, while for polyester matrix pressing was done in hydraulic press and following by curing at 70 deg. C in an oven for 1 hour. The composition of magnetic powder were varied to 30, 40 and 50% volume fraction and coupling agent were varied to 5, 10 and 15 ml for every volume fraction. The result showed that 10 ml added of coupling agent was give best mechanical properties both polyester and epoxy matrix. However generally, increasing of magnetic powder content decreased the tensile strength of magnetic composite. The properties of magnetic composite SrM was better than BaM either in polyester or epoxy matrix

Variation of intrinsic magnetic parameters of single domain Co-N interstitial nitrides synthesized via hexa-ammine cobalt nitrate route

Energy Technology Data Exchange (ETDEWEB)

Ningthoujam, R.S. [Department of Chemistry, Indian Institute of Technology, Kanpur 208016 (India); Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Panda, R.N., E-mail: rnp@bits-goa.ac.in [Chemistry Group, Birla Institute of Technology and Science-Pilani, Goa Campus, Zuari Nagar, Goa 403726 (India); Gajbhiye, N.S. [Department of Chemistry, Indian Institute of Technology, Kanpur 208016 (India)

2012-05-15

Highlights: Black-Right-Pointing-Pointer Variation of intrinsic magnetic parameters of Co-N. Black-Right-Pointing-Pointer Synthesis by hexa-ammine cobalt complex route. Black-Right-Pointing-Pointer Tuning of coercivity by variation of size. - Abstract: We report the variation of Curie temperature (T{sub c}) and coercivity (H{sub c}) of the single domain Co-N interstitial materials synthesized via nitridation of the hexa-ammine Cobalt(III) nitrate complex at 673 K. Co-N materials crystallize in the fcc cubic structure with unit cell parameter, a = 3.552 Angstrom-Sign . The X-ray diffraction (XRD) peaks are broader indicating the materials to be nano-structured with crystallite sizes of 5-14 nm. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies confirm the nanocrystalline nature of the materials. TEM images show chain-like clusters indicating dipolar interactions between the particles. Magnetic studies focus on the existence of giant magnetic Co atoms in the Co-N lattice that are not influenced by the thermal relaxation. The values of the H{sub c} could be tuned with the dimension of the particles. The values of T{sub c} of the nitride materials are masked by the onset of the ferromagnetic to superparamagnetic transition at higher temperatures. Thermomagnetic studies show an increasing trend in the Curie temperature, T{sub c}, with decrease in particle dimension. This result has been explained qualitatively on the basis of ferromagnetic to superparamagnetic transition and finite size scaling effects.

Solution processable monosubstituted hexa-peri-hexabenzocoronene self-assembling dyes

Energy Technology Data Exchange (ETDEWEB)

Ren, Shijie; Yan, Chao; Vak, Doojin; Jones, David J.; Holmes, Andrew B.; Wong, Wallace W.H. [School of Chemistry, University of Melbourne, Bio21 Institute, Parkville, Victoria (Australia)

2012-05-23

Molecular organization behavior and visible light absorption ability are important factors for organic materials to be used in efficient bulk heterojunction solar cells applications. In this context, a series of monosubstituted fluorenyl hexa-peri-hexabenzocoronene (FHBC) are synthesized with the aim to combine the self-association property of the FHBC unit with broadened light absorption of a small molecule organic dye, bisthienylbenzothiadiazole (TBT). Optical and electrochemical properties of the FHBC compounds vary according to their structures. Introduction of a TBT unit into the FHBC system broadens the absorption. All of the FHBC compounds show strong {pi}-{pi} intermolecular association in solution. X-ray scattering measurements on thermally extruded filaments and thin films showed ordered alignment of these compounds in the solid state. In atomic force microscopy experiments, nanoscale phase separation is observed in thin films of FHBC and fullerene derivative blends. Solar cell devices with these compounds as donors are fabricated. FHBC compounds with the TBT unit show higher short circuit current while the high open circuit voltages are maintained. With C{sub 60} derivative as acceptor, power conversion efficiency of 1.12% is achieved in the unoptimized solar cell devices under simulated solar irradiation. The efficiency was further improved to 1.64% when C{sub 70} derivative was used as the acceptor. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

N-Trimethyl chitosan (TMC) nanoparticles loaded with influenza subunit antigen for intranasal vaccination : Biological properties and immunogenicity in a mouse model

NARCIS (Netherlands)

Amidi, Maryam; Romeijn, Stefan G.; Verhoef, J. Coos; Junginger, Hans E.; Bungener, Laura; Huckriede, Anke; Crommelin, Daan J. A.; Jiskoot, Wim

2007-01-01

In this study, the potential of N-trimethyl chitosan (TMC) nanoparticles as a carrier system for the nasal delivery of a monovalent influenza subunit vaccine was investigated. The antigen-loaded nanoparticles were prepared by mixing a solution containing TMC and monovalent influenza A subunit H3N2

A Mesopore-Dependent Catalytic Cracking of n-Hexane Over Mesoporous Nanostructured ZSM-5.

Science.gov (United States)

Qamar, M; Ahmed, M I; Qamaruddin, M; Asif, M; Sanhoob, M; Muraza, O; Khan, M Y

2018-08-01

Herein, pore size, crystalinity, and Si/Al ratio of mesoporous ZSM-5 (MFI) nanocrystals was controlled by synthesis parameters, such as surfactant concentration ([3-(trimethoxysilyl)propyl] hexa-decyl dimethyl ammonium chloride), sodium hydroxide concentrations, synthesis temperature and time. The morphology, surface structure and composition of the MFI particles was systematically investigated. More notably, the mesopore-dependent catalytic activity of ZSM-5 was evaluated by studying the cracking of n-hexane. The findings suggest the porosity has pronounced impact on the catalytic activity, selectivity and stability of ZSM-5 nanocrystals. Critical surface attributes such as nature of acid sites (Brønsted and Lewis), concentration, and strength are obtained by the infrared study of adsorbed probe molecules (pyridine) and the temperature programmed desorption. In spite of being weaker in Si/Al ratio or acidic strength, mesoporous catalysts showed more stable and efficient cracking of n-hexane suggesting that acidity seems not the predominant factor operative in the activity, selectivity and stability.

Synthesis and properties of new cationic polymers on 2-[(methacryloyloxy)ethyl]trimethyl ammonium chloride and N-isopropylacrylamidet base

International Nuclear Information System (INIS)

Sergaziev, A.; Khutoryanskij, V.; Bajzhumanova, T.; Fefelova, N.; Nurkeeva, Z.

2003-01-01

New water-soluble cationic polyelectrolytes were synthesized by γ-radiation copolymerization of 2-[(methacryloyloxy)ethyl]trimethyl ammonium chloride and N-isopropylacrylamide. The phase transition of aqueous solutions of copolymers was studied with temperature increase in presence and absence of inorganic salts. The copolymers complexation with potassium hexacyano ferrates (II, III) was investigated. It was shown that the poly-complexes solubility depends on concentration of interacting reagents and temperature. (author)

Aryl-NHC-group 13 trimethyl complexes: structural, stability and bonding insights

KAUST Repository

Wu, Melissa M.; Gill, Arran M.; Yunpeng, Lu; Yongxin, Li; Ganguly, Rakesh; Falivene, Laura; Garcí a, Felipe

2016-01-01

Treatment of aromatic N-substituted N-heterocyclic carbenes (NHCs) with trimethyl-gallium and -indium yielded the new Lewis acid-base adducts, IMes·GaMe3 (1), SIMes·GaMe3 (2), IPr·GaMe3 (3), SIPr·GaMe3 (4), IMes·InMe3 (5), SIMes·InMe3 (6), IPr·InMe3 (7), and SIPr·InMe3 (8), with all complexes being identified by X-ray diffraction, IR, and multinuclear NMR analyses. Complex stability was found to be largely dependent on the nature of the constituent NHC ligands. Percent buried volume (%VBur) and topographic steric map analyses were employed to quantify and elucidate the observed trends. Additionally, a detailed bond snapping energy (BSE) decomposition analysis focusing on both steric and orbital interactions of the M-NHC bond (M = Al, Ga and In) has been performed.

Aryl-NHC-group 13 trimethyl complexes: structural, stability and bonding insights

KAUST Repository

Wu, Melissa M.

2016-12-14

Treatment of aromatic N-substituted N-heterocyclic carbenes (NHCs) with trimethyl-gallium and -indium yielded the new Lewis acid-base adducts, IMes·GaMe3 (1), SIMes·GaMe3 (2), IPr·GaMe3 (3), SIPr·GaMe3 (4), IMes·InMe3 (5), SIMes·InMe3 (6), IPr·InMe3 (7), and SIPr·InMe3 (8), with all complexes being identified by X-ray diffraction, IR, and multinuclear NMR analyses. Complex stability was found to be largely dependent on the nature of the constituent NHC ligands. Percent buried volume (%VBur) and topographic steric map analyses were employed to quantify and elucidate the observed trends. Additionally, a detailed bond snapping energy (BSE) decomposition analysis focusing on both steric and orbital interactions of the M-NHC bond (M = Al, Ga and In) has been performed.

Comparative Analyses of H3K4 and H3K27 Trimethylations Between the Mouse Cerebrum and Testis

KAUST Repository

Cui, Peng; Liu, Wanfe; Zhao, Yuhui; Lin, Qiang; Zhang, Daoyong; Ding, Feng; Xin, Chengqi; Zhang, Zhang; Song, Shuhui; Sun, Fanglin; Yu, Jun; Hu, Songnian

2012-01-01

The global features of H3K4 and H3K27 trimethylations (H3K4me3 and H3K27me3) have been well studied in recent years, but most of these studies were performed in mammalian cell lines. In this work, we generated the genome-wide maps of H3K4me3 and H3K

DFT investigation on the adsorption behavior of dimethyl and trimethyl amine molecules on borophene nanotube

Science.gov (United States)

Bhuvaneswari, R.; Chandiramouli, R.

2018-06-01

The electronic properties of borophene nanotube (BNT) are witnessed and the adsorption properties of dimethyl amine (DMA) and trimethyl amine (TMA) molecules on borophene nanotube are explored through non-equilibrium Green's function (NEGF) and density functional theory (DFT) method. The device density of states spectrum interprets the change in peak maxima, thus indicating the electron transition between DMA, TMA molecules and BNT base material. I-V characteristics strengthen the adsorption property of DMA and TMA on BNT by pointing out the variation in the current. The present work assures that borophene nanotube (BNT) can be employed as DMA and TMA sensor.

Molecular docking studies of (1E,3E,5E)-1,6-Bis(substituted phenyl)hexa-1,3,5-triene and 1,4-Bis(substituted trans-styryl)benzene analogs as novel tyrosinase inhibitors.

Science.gov (United States)

Ha, Young Mi; Lee, Hye Jin; Park, Daeui; Jeong, Hyoung Oh; Park, Ji Young; Park, Yun Jung; Lee, Kyung Jin; Lee, Ji Yeon; Moon, Hyung Ryong; Chung, Hae Young

2013-01-01

We simulated the docking of the tertiary structure of mushroom tyrosinase with our compounds. From the structure-tyrosinase inhibitory activity relationship, it is notable that compounds 4, 8 and 11 showed similar or better activity rates than kojic acid which was used as a positive control. Compounds 17, 21, and 23 among benzene analogs that possess the same substituent showed significantly lower tyrosinase inhibitory effects. Therefore, we have confirmed that among the compounds showing better tyrosinase inhibitory effects than kojic acid, the compounds with triene analogs have better tyrosinase inhibitory effect than the compounds with benzene analogs. Docking simulation suggested the mechanism of compounds by several key residues which had possible hydrogen bonding interactions. The pharmacophore model underlined the features of active compounds, 4,4'-((1E,3E,5E)-hexa-1,3,5-triene-1,6-diyl)diphenol, 5,5'-((1E,3E,5E)-hexa-1,3,5-triene-1,6-diyl)bis(2-methoxy-phenol), and 5,5'-((1E,3E,5E)-hexa-1,3,5-triene-1,6-diyl)dibenzene-1,3-diol among triene derivatives which had several hydrogen bond groups on both terminal rings. The soundness of the docking results and the agreement with the pharmacophores suggest that it can be conveniently exploited to design inhibitors with an improved affinity for tyrosinase.

Effects of magnetic pre-alignment of nano-powders on formation of high textured barium hexa-ferrite quasi-single crystals via a magnetic forming and liquid participation sintering route

International Nuclear Information System (INIS)

Liu, Junliang; Zeng, Yanwei; Zhang, Xingkai; Zhang, Ming

2015-01-01

Highly textured barium hexa-ferrite quasi-single crystal with narrow ferromagnetic resonance line-width is believed to be a potential gyromagnetic material for self-biased microwave devices. To fabricate barium hexa-ferrite quasi-single crystal with a high grain orientation degree, a magnetic forming and liquid participation sintering route has been developed. In this paper, the effects of the pre-alignment of the starting nano-powders on the formation of barium quasi-single crystal structures have been investigated. The results indicated that: the crystallites with large sizes and small specific surfaces were easily aligned for they got higher driving forces and lower resistances during magnetic forming. The average restricting magnetic field was about 4.647 kOe to overcome the average friction barrier between crystallites. The pre-aligned crystallites in magnetic forming acted as the “crystal seeds” for oriented growth of the un-aligned crystallites during liquid participation sintering to achieve a high grain orientation. To effectively promote the grain orientation degrees of the sintered pellets, the grain orientation degrees of the green compacts must be higher than a limited value of 15.0%. Barium hexa-ferrite quasi-single crystal with a high grain orientation degree of 98.6% was successfully fabricated after sintering the green compact with its grain orientation degree of 51.1%. - Highlights: • Aligned particles acted as “crystal seeds” for un-aligned ones' oriented growth. • Magnetic field of 4.647 kOe was needed to overcome crystallites' friction barrier. • GOD dramatically increased after sintering if starting GOD exceeded to 15.0%. • Quasi-single crystal was prepared by sintering green compact with GOD of 51.1%

Effects of magnetic pre-alignment of nano-powders on formation of high textured barium hexa-ferrite quasi-single crystals via a magnetic forming and liquid participation sintering route

Energy Technology Data Exchange (ETDEWEB)

Liu, Junliang, E-mail: liujunliang@yzu.edu.cn [Key Laboratory of Environmental Materials and Engineering of Jiangsu Province, School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Zeng, Yanwei [State Key Laboratory of Materials-Oriented Chemical Engineering, School of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China); Zhang, Xingkai [Key Laboratory of Environmental Materials and Engineering of Jiangsu Province, School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Zhang, Ming [Key Laboratory of Environmental Materials and Engineering of Jiangsu Province, School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Testing Center of Yangzhou University, Yangzhou 225002 (China)

2015-05-15

Highly textured barium hexa-ferrite quasi-single crystal with narrow ferromagnetic resonance line-width is believed to be a potential gyromagnetic material for self-biased microwave devices. To fabricate barium hexa-ferrite quasi-single crystal with a high grain orientation degree, a magnetic forming and liquid participation sintering route has been developed. In this paper, the effects of the pre-alignment of the starting nano-powders on the formation of barium quasi-single crystal structures have been investigated. The results indicated that: the crystallites with large sizes and small specific surfaces were easily aligned for they got higher driving forces and lower resistances during magnetic forming. The average restricting magnetic field was about 4.647 kOe to overcome the average friction barrier between crystallites. The pre-aligned crystallites in magnetic forming acted as the “crystal seeds” for oriented growth of the un-aligned crystallites during liquid participation sintering to achieve a high grain orientation. To effectively promote the grain orientation degrees of the sintered pellets, the grain orientation degrees of the green compacts must be higher than a limited value of 15.0%. Barium hexa-ferrite quasi-single crystal with a high grain orientation degree of 98.6% was successfully fabricated after sintering the green compact with its grain orientation degree of 51.1%. - Highlights: • Aligned particles acted as “crystal seeds” for un-aligned ones' oriented growth. • Magnetic field of 4.647 kOe was needed to overcome crystallites' friction barrier. • GOD dramatically increased after sintering if starting GOD exceeded to 15.0%. • Quasi-single crystal was prepared by sintering green compact with GOD of 51.1%.

A comparative study on the thermophysical properties for two bis[(trifluoromethyl)sulfonyl]imide-based ionic liquids containing the trimethyl-sulfonium or the trimethyl-ammonium cation in molecular solvents.

Science.gov (United States)

Couadou, Erwan; Jacquemin, Johan; Galiano, Hervé; Hardacre, Christopher; Anouti, Mérièm

2013-02-07

Herein, we present a comparative study of the thermophysical properties of two homologous ionic liquids, namely, trimethyl-sulfonium bis[(trifluoromethyl)sulfonyl]imide, [S(111)][TFSI], and trimethyl-ammonium bis[(trifluoromethyl)sulfonyl]imide, [HN(111)][TFSI], and their mixtures with propylene carbonate, acetonitrile, or gamma butyrolactone as a function of temperature and composition. The influence of solvent addition on the viscosity, conductivity, and thermal properties of IL solutions was studied as a function of the solvent mole fraction from the maximum solubility of IL, x(s), in each solvent to the pure solvent. In this case, x(s) is the composition corresponding to the maximum salt solubility in each liquid solvent at a given temperature from 258.15 to 353.15 K. The effect of temperature on the transport properties of each binary mixture was then investigated by fitting the experimental data using Arrhenius' law and the Vogel-Tamman-Fulcher (VTF) equation. The experimental data shows that the residual conductivity at low temperature, e.g., 263.15 K, of each binary mixture is exceptionally high. For example, conductivity values up to 35 and 42 mS·cm(-1) were observed in the case of the [S(111)][TFSI] + ACN and [HN(111)][TFSI] + ACN binary mixtures, respectively. Subsequently, a theoretical approach based on the conductivity and on the viscosity of electrolytes was formulated by treating the migration of ions as a dynamical process governed by ion-ion and solvent-ion interactions. Within this model, viscosity data sets were first analyzed using the Jones-Dole equation. Using this theoretical approach, excellent agreement was obtained between the experimental and calculated conductivities for the binary mixtures investigated at 298.15 K as a function of the composition up to the maximum solubility of the IL. Finally, the thermal characterization of the IL solutions, using DSC measurements, showed a number of features corresponding to different solid

Conservation of complete trimethylation of lysine-43 in the rotor ring of c-subunits of metazoan adenosine triphosphate (ATP) synthases.

Science.gov (United States)

Walpole, Thomas B; Palmer, David N; Jiang, Huibing; Ding, Shujing; Fearnley, Ian M; Walker, John E

2015-04-01

The rotors of ATP synthases turn about 100 times every second. One essential component of the rotor is a ring of hydrophobic c-subunits in the membrane domain of the enzyme. The rotation of these c-rings is driven by a transmembrane proton-motive force, and they turn against a surface provided by another membrane protein, known as subunit a. Together, the rotating c-ring and the static subunit a provide a pathway for protons through the membrane in which the c-ring and subunit a are embedded. Vertebrate and invertebrate c-subunits are well conserved. In the structure of the bovine F1-ATPase-c-ring subcomplex, the 75 amino acid c-subunit is folded into two transmembrane α-helices linked by a short loop. Each bovine rotor-ring consists of eight c-subunits with the N- and C-terminal α-helices forming concentric inner and outer rings, with the loop regions exposed to the phospholipid head-group region on the matrix side of the inner membrane. Lysine-43 is in the loop region and its ε-amino group is completely trimethylated. The role of this modification is unknown. If the trimethylated lysine-43 plays some important role in the functioning, assembly or degradation of the c-ring, it would be expected to persist throughout vertebrates and possibly invertebrates also. Therefore, we have carried out a proteomic analysis of c-subunits across representative species from different classes of vertebrates and from invertebrate phyla. In the twenty-nine metazoan species that have been examined, the complete methylation of lysine-43 is conserved, and it is likely to be conserved throughout the more than two million extant metazoan species. In unicellular eukaryotes and prokaryotes, when the lysine is conserved it is unmethylated, and the stoichiometries of c-subunits vary from 9-15. One possible role for the trimethylated residue is to provide a site for the specific binding of cardiolipin, an essential component of ATP synthases in mitochondria. © 2015 by The American

Studies on the obtention and characterization of N,N,N-trimethyl chitosan (TMC)

International Nuclear Information System (INIS)

Curti, Elisabete; Campana Filho, Sergio P.

2001-01-01

In this work, a study was developed on the obtention of N,N,N-trimethyl chitosan (TMC) aiming the preparation of samples with different average degrees of quaternization under controlled experimental conditions. The effects of previous treatments of chitosan on the reactivity toward its N-alkylation were evaluated and it was concluded that the purification method previously applied to chitosan strongly influenced the reaction yield. The average degrees of quaternization of the TMC samples were determined by nuclear magnetic resonance spectroscopy and they ranged from 4,0% to 22%, depending on the previous treatment to which the chitosan was submitted and on the reaction conditions. It was also concluded that an average degree of quaternization close to 4,0% is already high enough to impart water solubility to this chitosan derivative. (author)

N-Decyl-S-trityl-(R)-cysteine, a new chiral selector for "green" ligand-exchange chromatography applications.

Science.gov (United States)

Carotti, Andrea; Ianni, Federica; Camaioni, Emidio; Pucciarini, Lucia; Marinozzi, Maura; Sardella, Roccaldo; Natalini, Benedetto

2017-09-10

In search for new enantioselectivity profiles, the N-decyl-S-trityl-(R)-cysteine [C 10 -(R)-STC] was synthesized through a one-step procedure and then hydrophobically adsorbed onto an octadecylsilica surface to generate a stable chiral stationary phase for ligand-exchange chromatography (CLEC-CSP) applications. The CLEC analysis was carried out on underivatized amino acids, by using a Cu(II) sulphate (1.0mM) containing aqueous eluent system. Most of the analysed compounds (34 out of 45) were enantiodiscriminated by the C 10 -(R)-STC-based CSP, with resolution factor (R S ) values up to 8.86. Conformationally rigid and hydrophobic ligands often experienced the largest enantioselectivity effects. A high loadability emerged from the analysis of rac-NorVal (selected as prototype test compound): up to 20mg/mL were efficiently enantioseparated with the CLEC-CSP. Two in-line hand-made cartridges filled with a strong cation-exchange resin allowed the effective catching of Cu(II) ions after the semi-preparative enantioseparation. The quantitative recovery of the rac-NorVal enantiomers was made possible by flowing through the cartridge a 5% (v) ammonia solution. The CLEC phase proved successful in the enantioselective analysis of a commercially available (S)-Leu containing tablet. Furthermore, in order to understand the molecular basis for a successful use of the C 10 -(R)-STC-based CLEC system, a descriptive structure-separation relationship study was performed. As a result, all compounds with a MEAN-QPlogS (a hydrophilicity descriptor) value lower than 0.373 can be most likely enantioseparated with the CLEC system under investigation. In the work, the numerous aspects complying with the principles of green chromatography are highlighted and discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel nanoparticulate carrier system based on carnauba wax and decyl oleate for the dispersion of inorganic sunscreens in aqueous media.

Science.gov (United States)

Villalobos-Hernández, J R; Müller-Goymann, C C

2005-05-01

The purpose of this study was to characterize carrier systems for inorganic sunscreens based on a matrix composed of carnauba wax and decyl oleate. Ultraviolet radiation attenuators like barium sulfate, strontium carbonate and titanium dioxide were tested. The lipid matrices were used either as capsules or as accompanying vehicles for the pigments in aqueous dispersions. Manufacturing was performed using high pressure homogenization at 300bar and a temperature of 75 degrees C. To evaluate the effect of the pigments on the crystalline structure of the wax-oil mixture, X-ray diffraction and differential scanning calorimetry were used. Further parameters determined were particle size, polydispersity index, z-potential, viscosity and sun protection factor (SPF). Transmission electron microscopy was also applied for visualization of nanoparticles. The X-ray diffraction patterns and the melting points of the lipid mixtures remained unchanged after the pigments were added. The particle sizes of the encapsulated species ranged from 239 to 749.9nm showing polydispersity values between 0.100 and 0.425. Surface charge measurements comprising values up to -40.8mV denoted the presence of stable dispersions. The formulations could be described as ideal viscous presenting viscosities in a range of 1.40-20.5mPas. Significant increases in SPF up to about 50 were reported after the encapsulation of titanium dioxide. Freeze fracture micrographs confirmed the presence of encapsulated inorganic crystals.

Tailorable thiolated trimethyl chitosans for covalently stabilized nanoparticles.

Science.gov (United States)

Verheul, Rolf J; van der Wal, Steffen; Hennink, Wim E

2010-08-09

A novel four-step method is presented to synthesize partially thiolated trimethylated chitosan (TMC) with a tailorable degree of quaternization and thiolation. First, chitosan was partially N-carboxylated with glyoxylic acid and sodium borohydride. Next, the remaining amines were quantitatively dimethylated with formaldehyde and sodium borohydride and then quaternized with iodomethane in NMP. Subsequently, these partially carboxylated TMCs dissolved in water were reacted with cystamine at pH 5.5 using EDC as coupling agent. After addition of DTT and dialysis, thiolated TMCs were obtained, varying in degree of quaternization (25-54%) and degree of thiolation (5-7%), as determined with (1)H NMR and Ellman's assay. Gel permeation chromatography with light scattering detection indicated limited intermolecular cross-linking. All thiolated TMCs showed rapid oxidation to yield disulfide cross-linked TMC at pH 7.4, while the thiolated polymers were rather stable at pH 4.0. When Calu-3 cells were used, XTT and LDH cell viability tests showed a slight reduction in cytotoxicity for thiolated TMCs as compared to the nonthiolated polymers with similar DQs. Positively charged nanoparticles loaded with fluorescently labeled ovalbumin were made from thiolated TMCs and thiolated hyaluronic acid. The stability of these particles was confirmed in 0.8 M NaCl, in contrast to particles made from nonthiolated polymers that dissociated under these conditions, demonstrating that the particles were held together by intermolecular disulfide bonds.

The magnetic properties of aligned M hexa-ferrite fibres

International Nuclear Information System (INIS)

Pullar, R.C.; Bhattacharya, A.K.

2006-01-01

Aligned and random fibres of strontium hexa ferrite (SrM, SrFe 12 O 19 ) and barium hexaferrite (BaM, BaFe 12 O 19 ) were manufactured by blow spinning from an aqueous inorganic sol-gel precursor, which was then fired to give the hexagonal ferrite fibre. Their magnetic properties were studied by VSM, investigating the evolution of these properties with firing and measurement temperature, and in particular the effects of fibre alignment. It has been predicted that aligned ferrite fibres will demonstrate an enhanced magnetisation along the axis of alignment with respect to perpendicular to the axis, and this has been demonstrated here for the first time. The optimum firing temperature was 1000 deg. C, at which point they still had submicron grains. In BaM random fibres M s =63.8 emu g -1 and H c =428.1 kA m -1 , and in SrM random fibres M s =63.3 emu g -1 and H c =452.8 kA m -1 , high values for polycrystalline materials. Fibres aligned parallel to the applied field had saturation magnetisation (M s ) values equal to those of the random fibres, whilst fibres aligned perpendicular to the field had M s values 62% and 75% lower, for BaM and SrM, respectively. There was no change in coercivity (H c ) between random or aligned fibres of any orientation, and fibres aligned 45 deg. and parallel to H appeared identical. Therefore, properties along the axis of alignment were superior when compared to measurements perpendicular to the axis of alignment, giving a directionality to the magnetisation in an otherwise randomly oriented ferrite material

μ-Hexa­thio­metadiphosphato-bis­[(1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane-κ6 O)rubidium] aceto­nitrile disolvate

Science.gov (United States)

Gjikaj, Mimoza; Pook, Niels-Patrick; Qarri, Flora

2013-01-01

The asymmetric unit of the title compound, [Rb2(P2S6)(C12H24O6)2]·2CH3CN, contains one half of an [Rb(18-crown-6)2]2[P2S6] unit and one aceto­nitrile solvent mol­ecule. The [Rb(18-crown-6)]2[P2S6] unit is completed by inversion symmetry. Its Rb+ ion is situated near the centre of the macrocyclic cavity, but is displaced by 0.8972 (1) Å from the O atoms of the crown in the direction of the [P2S6]2− moiety. The overall coordination number of the cation is eight, defined by the six crown ether O atoms and by two terminal S atoms of the [P2S6]2− anion. The hexa­thio­metadiphosphate anion is built up from two tetra­hedral PS4 units joined together by a common edge. The crystal structure is characterized by alternating layers of [Rb(18-crown-6)]2[P2S6] and aceto­nitrile solvent mol­ecules stacked along [010]. PMID:24860286

Synthesis of 8-phenyl-10H-pyrido[1,2-α]indole salts from 2,3,3-trimethyl-3H-indole chlorides with cinnamaldehyde

International Nuclear Information System (INIS)

Shachkus, A.A.; Degutis, Yu.A.

1987-01-01

Reaction of 2,3,3-trimethyl-3H-indole chloride with cinnamic and 4-dimethylaminocinnamic aldehydes led to salts of 8-phenyl and 8-(4-dimethylaminophenyl)-10,10-dimethyl-10H-pyrido[1,2-α]indole. PMR spectra were recorded on a Tesla BS-487C (80 MHz) instrument (internal standard HMDS) and IR spectra on a UR-20 spectrometer (KBr pellets)

An association between diet quality index for Koreans (DQI-K) and total mortality in Health Examinees Gem (HEXA-G) study.

Science.gov (United States)

Lim, Jiyeon; Lee, Yunhee; Shin, Sangah; Lee, Hwi-Won; Kim, Claire E; Lee, Jong-Koo; Lee, Sang-Ah; Kang, Daehee

2018-06-01

Diet quality scores or indices, based on dietary guidelines, are used to summarize dietary intake into a single numeric variable. The aim of this study was to examine the association between the modified diet quality index for Koreans (DQI-K) and mortality among Health Examinees-Gem (HEXA-G) study participants. The DQI-K was modified from the original diet quality index. A total of 134,547 participants (45,207 men and 89,340 women) from the HEXA-G study (2004 and 2013) were included. The DQI-K is based on eight components: 1) daily protein intake, 2) percent of energy from fat, 3) percent of energy from saturated fat, 4) daily cholesterol intake, 5) daily whole-grain intake, 6) daily fruit intake, 7) daily vegetable intake, and 8) daily sodium intake. The association between all-cause mortality and the DQI-K was examined using Cox proportional hazard regression models. Hazard ratios and confidence intervals were estimated after adjusting for age, gender, income, smoking status, alcohol drinking, body mass index, and total energy intake. The total DQI-K score was calculated by summing the scores of the eight components (range 0-9). In the multivariable adjusted models, with good diet quality (score 0-4) as a reference, poor diet quality (score 5-9) was associated with an increased risk of all-cause mortality (hazard ratios = 1.23, 95% confidence intervals = 1.06-1.43). Moreover, a one-unit increase in DQI-K score resulted in a 6% higher mortality risk. A poor diet quality DQI-K score was associated with an increased risk of mortality. The DQI-K in the present study may be used to assess the diet quality of Korean adults.

Molecular characterization of a novel HEXA mutation at the +3 position of intron 8 in a Tay-Sachs disease patient

Energy Technology Data Exchange (ETDEWEB)

Richard, M.; Triggs-Raine, B. [Univ. of Manitoba, Winnipeg (Canada); Natowicz, M. [E.K. Shriver Center, Waltham, MA (United States)

1994-09-01

Tay-Sachs disease is an autosomal recessive lysosomal storage disorder resulting from mutations in the HEXA gene that cause a deficiency in the activity of that enzyme {beta}-hexosaminidase A (Hex A). This deficiency leads to the build-up of G{sub M2} ganglioside, resulting in neurodegeneration and death. Biochemical analysis of a non-Jewish patient with a late-infantile form of Tay-Sachs disease revealed a substantial level of Hex A activity (38.4%) when 4-MUG was used as the substrate. However, when a substrate (4-MUGS) specific for the {alpha}-subunit of Hex A ({alpha}{beta}) was used, almost no activity was detected in the HEXA gene of the patient using SSCP analysis followed by sequencing. The first mutation, a G533A substitution in exon 5, is previously described and associated with the B1 form of Tay-Sachs disease. The second mutation is a novel a-to-g base change at the +3 position of intron 8. This was confirmed using the AIRS method, whereby a MaeIII site was created in the presence of the mutation. Normal and patient mRNA was reverse transcribed and exons 7 to 9 were PCR-amplified from the cDNA. An abnormally sized amplification product detected only in the patient cDNA was sequenced; exon 8 had been deleted and exons 7 and 9 were spliced together. A substantial level of normally-sized PCR product was also detected in the patient`s cDNA. Experiments are in progress to determine if this is produced from the allele harboring the G533A mutation. Given that previous mutations of this type have been associated with 97-100% abnormal splicing, this mutation is likely to be the cause, together with the G533A mutation, of Tay-Sachs disease in this patient.

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

International Nuclear Information System (INIS)

Hamada, E.S.

1994-01-01

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

Perchlorate adsorption by granular activated carbon modified with cetyl trimethyl ammonium chloride

International Nuclear Information System (INIS)

Yin-Xian, P.; Lu, Z.; Cui-Yun, C.; Ming-Long, Z.; Yang, Z.; Chun-Du, W.

2012-01-01

To improve the adsorption of perchlorate (ClO/sub 4/ in contaminated water, granular activated carbon (GAC) was modified with cetyl trimethyl ammonium chloride (CTAC). To investigate the adsorption mechanism of perchlorate the structure of GAC-CTAC was characterized by scanning electron microscopy (SEM) and FTIR spectroscopy. Then the GAC-CTAC was used for the adsorption of perchlorate in water. The effects of the adsorption time, pH, initial ClO/sub 4/ concentration, and co-existed anions on perchlorate adsorbed by GAC-CTAC were studied. The results show that the GAC-CTAC could absorb perchlorate better in water. The adsorption capacity of perchlorate on GAC-CTAC decreases in the alkaline solution, and increases with increasing the - initial concentration. The competitive adsorption exists between co-existed anions and ClO/sub 4/ on GAC-CTAC. In addition, adsorption of ClO/sub 4/ on GAC-CTAC fits the Langmuir, Freundlich and Tempkin isothermal models in the range of the experimental concentration. The adsorption process follows pseudo-second order kinetics. (author)

Dose- and time-dependent pharmacokinetics of apigenin trimethyl ether.

Science.gov (United States)

Elhennawy, Mai Gamal; Lin, Hai-Shu

2018-06-15

Apigenin trimethyl ether (5,7,4'-trimethoxyflavone, ATE), one of the key polymethoxyflavones present in black ginger (rhizome of Kaempferia parviflora) possesses various health-promoting activities. To optimize its medicinal application, the pharmacokinetics of ATE was assessed in Sprague-Dawley rats with emphases to identify the impacts from dose and repeated dosing on its major pharmacokinetic parameters. Plasma ATE levels were monitored by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Upon single intravenous administration (2 mg/kg), plasma levels of ATE declined through an apparent first-order process while dose-escalation to 4 and 8 mg/kg led to its non-linear disposition, which could be described by the Michaelis-Menten model. Similarly, dose-dependent oral pharmacokinetics was confirmed and when the dose was escalated from 5 to 15 and 45 mg/kg, much longer mean residence time (MRT 0→last ), higher dose-normalized maximal plasma concentration (C max /Dose) and exposure (AUC/Dose) were observed at 15 and/or 45 mg/kg. One-week daily oral administration of ATE at 15 mg/kg caused its accelerated elimination and the plasma exposure (AUC) after intravenous (2 mg/kg) and oral administration (15 mg/kg) dropped ~40 and 60%, respectively. As ATE displayed both dose- and time-dependent pharmacokinetics, caution is needed in the medicinal applications of ATE and/or black ginger. Copyright © 2018 Elsevier B.V. All rights reserved.

Synchrotron x-ray study of the orientational ordering D2-D1 structural phase transition of freely suspended discotic strands in triphenylene hexa-n-dodecanoate

International Nuclear Information System (INIS)

Safinya, C.R.; Liang, K.S.; Varady, W.A.; Clark, N.A.; Andersson, G.

1984-01-01

We demonstrate the feasibility of x-ray scattering studies of freely suspended strands of discotic liquid crystals (of triphenylene hexa-n-dodecanoate). We are able to grow strands, which are stable for days, of diameter >50 μm with a few single crystal domains. Unexpectedly, we find that the quasi two-dimensional structural phase transition from columnar D2 to columnar D1 corresponds to the orientational ordering of columns of molecules with the molecules tilted at finite angles to the column axis in both phases

[Reduction of 137caesium contamination in wild boars by supplementing offered food with ammonium-iron-hexa-cyanoferrate].

Science.gov (United States)

Morfeld, P; Reddemann, J; Schungel, P; Kienzle, E

2014-01-01

This replication study investigated whether the 137caesium (137Cs) contamination of wild boars could be relevantly reduced under field conditions by adding ammonium-iron-hexa-cyanoferrate (AFCF; Prussian blue) to the food. In 285 wild boars that had been shot in six Bavarian hunting territories during the season (November until May) between 01 November 2010 and 10 December 2011 137Cs contamination was analysed. Thirty-five animals originated from two hunting territories in which offered food had been supplemented with 1250 mg AFCF per kilogram food. The control animals showed a mean 137Cs contamination of 522 Bq/kg lean skeletal muscle meat. Direct (univariable) comparisons of the two experimental territories with the four control territories yielded a mean reduction in 137Cs contamination due to Prussian bluefeeding by -211 Bq/kg (p contamination by -380 Bq/kg due to the feeding of Prussian blue in other territories.

Expression of the benign HEXA mutations, Arg247Trp and Arg249Trp, associated with beta-hexosaminidase A pseudodeficiency

Energy Technology Data Exchange (ETDEWEB)

Cao, Z.; Petroulakis, E.; Salo, T. [Univ. of Manitoba (Canada)] [and others

1994-09-01

{beta}-Hexosaminidase (Hex A) is a heterodimer of {alpha} and {beta} subunits encoded by the HEXA and HEXB genes, respectively. Mutations in the HEXA gene typically cause Tay-Sachs disease or less severe forms of G{sub M2} gangliosidosis. However, two benign mutations (Arg247Trp and Arg249Trp) in the {alpha}-subunit of Hex A account for Hex A deficiency in {approximately}36% of non-Jewish enzyme-defined Tay-Sachs disease carriers. These mutations do not result in any apparent clinical phenotype in individuals who are genetic compounds with a second disease-causing mutation. We expressed the {alpha}-subunit harboring each of the benign mutations separately to study activity toward the synthetic substrate, 4-MUGS, for comparison to activity from enzymes containing mutations associated with other forms of G{sub M2} gangliosidosis. The C739T (Arg247Trp;benign), C745T (Arg 249Trp; benign), G805A (Gly269Ser; adult-onset), G749A (Gly250Asp; juvenile), and C508T (Arg170Trp; infantile) mutations were introduced into the {alpha}-subunit cDNA. These were transfected alone, or with the {beta}-subunit cDNA, to generate Hex S ({alpha}{alpha}) or Hex A ({alpha}{beta}), respectively. The activities were monitored using 4-MUGS, and the levels of {alpha}-subunit protein were assessed by Western blotting. Repeated experiments show that the benign mutations produce approximately 35% of normal Hex S and 40% of normal Hex A activity. This level is much higher than that of Hex A harbouring the Gly169Ser adult-onset mutation (12%). A sequential decrease in expressed Hex A activity is observed as mutations associated with more severe phenotypes are expressed. The benign mutations also result in lower levels of mature {alpha}-subunit protein compared to normal, and slightly reduced levels of {alpha}-subunit precursor protein. The Hex A deficiency resulting from benign mutations is not as great as that associated with disease-causing mutations.

The corrosion inhibition of pure zinc in NH{sub 4}Cl aqueous solutions by N-Alkyl quaternary ammonium bromides

Energy Technology Data Exchange (ETDEWEB)

Branzoi, V.; Pilan, Luisa; Pruna, Alina [University ' Politehnica' of Bucharest, Faculty of Industrial Chemistry, Department of Physical Chemistry and Electrochemistry, Calea Grivitei, 132, Bucharest (Romania); Branzoi, Florina [Institute of Physical Chemistry Bucharest, Splaiul Independentei, 202, Bucharest (Romania)

2004-07-01

The corrosion of zinc in NH{sub 4}Cl solutions of different concentrations has been studied by potentiostatic and potentiodynamic methods and by impedance measurements. The results obtained in a potential region near the zinc corrosion potential showed that the cathodic reaction of hydrogen discharge does not fit a simple exponential law because the Tafel coefficient appears to be electrode potential dependent. At low overvoltages, in the anodic region, the corrosion process is under activation control, while at high overvoltages the process is under diffusion control. N-dodecyl, n-tetra-decyl and n-hexa-decyl ammonium bromides were used as organic inhibitors. The potentiostatic and potentiodynamic polarization studies and EIS measurements showed that each quaternary ammonium salt inhibits the corrosion of pure zinc in 1M NH{sub 4}Cl at 30 deg. C. The inhibition efficiency of the cations was discussed on the basis of Coulomb adsorption behaviour, using molecular coverage areas and polar substituent constant. The inhibition efficiency obtained from the corrosion currents was found to increase linearly with an increase in the molecular coverage area (A) for the series of tetra-alkyl ammonium ions. The efficiency of the cations increased with an increase in the positive charge of the nitrogen atom, which was due to the inductive effect of the electron-attractive groups. This effect on the Coulomb adsorption of the cations was, however, far less than that of the electron donating groups on the chemisorption of un-protonated amines. The steric requirements for the adsorption of the quaternaries with branched alkyl chains were small. Each organic compound exhibits Langmuir behaviour and inhibition increases with increasing alkyl chain length. This is attributed to cohesive Van der Waals forces between the positive head groups co-adsorbed with bromide ions on the positively charged zinc surface. (authors)

Gamma sterilization of diclofenac sodium loaded- N-trimethyl chitosan nanoparticles for ophthalmic use.

Science.gov (United States)

Asasutjarit, Rathapon; Theerachayanan, Thitaree; Kewsuwan, Prartana; Veeranondha, Sukitaya; Fuongfuchat, Asira; Ritthidej, Garnpimol C

2017-02-10

This study was conducted to investigate the effect of gamma irradiation on physicochemical properties of N-trimethyl chitosan (TMC), diclofenac sodium (DC) and diclofenac sodium loaded N-trimethylchitosan nanoparticles (DC-TMCNs), and to determine suitable doses of gamma rays for sterilization of DC-TMCNs. Physicochemical properties of TMC, DC and DC-TMCNs before and after exposure to gamma rays at various doses were investigated. It was found that gamma irradiation at doses of 5-25kGy did not cause any significant changes in physical and chemical properties of TMC, DC and DC-TMCNs. The bioburden of DC-TMCNs was 1.5×10 6 CFU/vial. The initial contaminating bacteria were radiosensitive bacteria. A number of microorganisms was reduced to 10 -6 after exposure to 9.9kGy of gamma rays. Therefore, DC-TMCNs could be sterilized by gamma irradiation at a dose of 10kGy, which did not alter their physicochemical properties and did not produce any substances toxic to the eye. Copyright © 2016 Elsevier Ltd. All rights reserved.

Kinetics Modeling and Isotherms for Adsorption of Phosphate from Aqueous Solution by Modified Clinoptilolit

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Mohammad Malakootian

2012-01-01

Full Text Available The Phosphorous discharge into the surface water led to excessive growth of algae and eutrophication in lakes and rivers. Therefore the phosphorus removal is important due to negative effect on water resources. The aim of this study was to investigat the modification of clinoptilolite and application of modified clinoptilolite for phosphorous adsorption from aqueous solution and isotherms and kinetics modeling. Hexadecyl Trimethyl Ammonium bromide (HDTMA-Br, Hexadecyl trimethyl Ammonium Chloride (HDTMA-Cl, Sodium Decyl Sulphate (SDS and Cetrimide-C were used for modification of clinoptilolite. Experiments were conducted using jar apparatus and batch system. The effect of pH, adsorbent doses, contact time, phosphate initial concentration and particle size were studied surveyed on phosphate adsorption by modified clinoptilolite. The most common isotherms and the kinetics adsorption equations were used for determination of adsorption rate and dynamic reaction. The results showed that maximum phosphate adsorption was obtained in the pH of 7 and contact time 90min. Also it was found with the increasing of phosphate initial concentration, phosphate removal efficiency decreased significantly. Langmuir No 2 showed a good correlation compared to other isotherms (R2=0.997. Maximum adsorption capacity was obtained in 20g/L adsorbent dose (22.73mg/g. Also Interaparticle diffusion kinetics well fits with experimental data (R2=0.999 with constant rate of 3.84mg/g min0.5. The result showed that modified clinoptilolite can be used successfully as low cost and effective absorbent for phosphate removal.

Defense of cutaneous cells against uv irradiation. II. Restricted photomediated binding of trimethyl psoralen to pigmented skin in vivo

International Nuclear Information System (INIS)

Carter, D.M.; Jegasothy, B.V.; Condit, E.S.

1973-01-01

Distinct differences in grain distribution were seen in autoradiographs of pigmented and nonpigmented skin from spotted guinea-pig ears subjected to photosensitizing conditions by the topical application of tritiated trimethyl psoralen ( 3 H TMP) and exposure to uv irradiation at 365 nm. Grains were localized over cells throughout the epidermis in nonpigmented skin, but they were not seen beneath the stratum corneum in pigmented skin. Since TMP covalently binds to epidermal nucleic acids only after irradiation, these experiments demonstrate that the compacted melanized cells of the outer epidermis shield the DNA of underlying cells by severely restricting the penetration of uv light into the skin. (auth)

NITROAROMATIC COMPOUND SENSING APPLICATION OF HEXA-ARMED DANSYL END-CAPPED POLY(epsilon-CAPROLACTONE STAR POLYMER WITH PHOSPHAZENE CORE

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Merve DANDAN DOGANCI

2016-09-01

Full Text Available Hexa-armed dansyl end-capped poly(ε-caprolactone star polymer with phosphazene core (N3P3-(PCL-Dansyl6 was prepared in a two-step synthetic procedure including ring opening polymerization (ROP of ε-caprolactone (ε-CL and esterification reactions. The obtained fluorescence-active polymer was employed as a fluorescent probe towards certain nitroaromatic compounds (2,4,6-trinitrotoluene (TNT, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitrotoluene, 3-nitrotoluene, 2,4,6-trinitrophenol (picric acid, 2,4-dinitrophenol, 4-nitrophenol, and 1,2-dinitrobenzene. Fluorescence intensity of N3P3-(PCL-Dansyl6 was decreased gradually upon the addition of nitroaromatic compounds and the highest quenching efficiency was found to be 100% with TNT. Besides, N3P3-(PCL-Dansyl6 gave exceptionally selective response toward nitroaromatic compounds, even in the presence of toxic metal cations such as Pb2+, Co2+, Hg2+, Mn2+, Cd2+ and Zn2+.

Trimethyl and carboxymethyl chitosan carriers for bio-active polymer-inorganic nanocomposites.

Science.gov (United States)

Geisberger, Georg; Gyenge, Emina Besic; Maake, Caroline; Patzke, Greta R

2013-01-02

The carrier properties of carboxymethyl chitosan (CMC) and trimethyl chitosan (TMC) in combination with polyoxometalates (POMs) as inorganic drug prototypes are compared with respect to the influence of polymer matrix charge and structure on the emerging composites. A direct crosslinking approach with TMC and K(6)H(2)[CoW(11)TiO(40)]·13H(2)O ({CoW(11)TiO(40)}) as a representative anticancer POM affords nanocomposites with a size range of 50-90nm. The obtained POM-chitosan composites are characterized with a wide range of analytical methods, and POM encapsulation into positively charged TMC brings forward different nanocomposite morphologies and properties than CMC as a carrier material. Furthermore, uptake of fluorescein isothiocyanate (FITC) labeled POM-CMC and POM-TMC by HeLa cells was monitored, and the influence of chlorpromazine (CP) as inhibitor of the clathrin mediated pathway revealed different cellular uptake behavior of composites and pristine carriers. TMC/{CoW(11)TiO(40)} nanocomposites are taken up by HeLa cells after short incubation times around 30 min at low concentrations. The anticancer activity of pristine {CoW(11)TiO(40)} and its TMC-nanocomposites was investigated in vitro with MTT assays and compared to a reference POM. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enhancement of methylbenzene adsorption capacity through cetyl trimethyl ammonium bromide-modified activated carbon derived from Astragalus residue

Science.gov (United States)

Feng, Ningchuan; Zhang, Yumei; Fan, Wei; Zhu, Meilin

2018-02-01

Activated carbon was prepared from astragalus residue by KOH and then treated with cetyl trimethyl ammonium bromide (CTAB) and used for the removal of methylbenzene from aqueous solution. The samples were characterized by FTIR, XRD, SEM and Boehm titration. The results showed that CTAB changed the physicochemical properties of activated carbon significantly. The isotherm adsorption studies of methylbenzene onto the astragalus residue activated carbon (ASC) and CTAB-modified astragalus residue activated carbon (ASCCTAB) were examined by using batch techniques and agreed well with the Langmuir model. The maximum adsorption capacity of ASC and ASC-CTAB for methylbenzene determined from the Langmuir model was183.56 mg/g and 235.18 mg/g, respectively. The results indicated that using CTAB as a modifier for ASC modification could markedly enhance the methylbenzene removal from water.

40 CFR 180.1281 - S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1-cyclohex-2-enyl)-3-methyl-penta-(2Z,4E...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false S-Abscisic Acid, (S)-5-(1-hydroxy-2,6... Exemptions From Tolerances § 180.1281 S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1-cyclohex-2... from the requirement of a tolerance is established for residues of S-Abscisic Acid in or on all food...

Development of new additive for drilling fluid from the partial hydrophobization N,N,N-trimethyl chitosan (TMC)

International Nuclear Information System (INIS)

Carmo, Thacyla C. do; Lopes, Grazielle; Silva, Joaquim F.M. da; Nascimento, Regina S.V.

2009-01-01

N,N,N-trimethyl chitosan (TMC) hydrophobically modified can act as an excellent additive for drilling fluids water based, working as inhibitor of reactive shales and rheological modifiers. The cationic chitosan was obtained by reaction of chitosan with CH 3 I in N-methyl-2-pyrrolidone to obtain the TMC and chitosan was also hydrophobically modified with palmitoil chloride to get Quit P. Through another route, Quit P was modified to obtain the cationic TMCP. The derivatives were characterized by FT-IR and 1 HNMR spectrophotometry allowing the calculation of the degree of quaternization of the TMC. The rheology tests showed that the system with TMCP presented pseudo plastic behavior, while the system with TMC behaved as a Newtonian fluid. The results indicated that TMCP can act as rheology modifier for water-based drilling fluids. (author)

4,4',5'-trimethyl-8-azapsoralen, a new-photoreactive and non-skin-phototoxic bifunctional bioisoster of psoralen.

Science.gov (United States)

Vedaldi, D; Dall'Acqua, F; Caffieri, S; Baccichetti, F; Carlassare, F; Bordin, F; Chilin, A; Guiotto, A

1991-01-01

Photochemical and photobiological properties of a new isoster of psoralen, 4,4',5'-trimethyl-8-azapsoralen (4,4',5'-TMAP), have been studied. This compound shows a high DNA-photobinding rate, higher than that of 8-methoxypsoralen (8-MOP), forming both monoadducts and inter-strand cross-links. The yield of cross-links, however, is markedly lower than that of 8-MOP. Antiproliferative activity of 4,4',5'-TMAP, in terms of DNA synthesis inhibition in Ehrlich ascites tumor cells, is higher than that of 8-MOP. Mutagenic activity on E. coli WP2 R46+ cells appeared similar to or even lower than that of 8-MOP. This new compound applied on depilated guinea pig skin and irradiated with UVA did not show any skin-phototoxicity. On the basis of these properties 4,4',5'-TMAP appears to be a potential photochemotherapeutic agent.

Mitochondrial-Targeted Decyl-Triphenylphosphonium Enhances 2-Deoxy-D-Glucose Mediated Oxidative Stress and Clonogenic Killing of Multiple Myeloma Cells.

Directory of Open Access Journals (Sweden)

Jeanine Schibler

Full Text Available Therapeutic advances have markedly prolonged overall survival in multiple myeloma (MM but the disease currently remains incurable. In a panel of MM cell lines (MM.1S, OPM-2, H929, and U266, using CD138 immunophenotyping, side population staining, and stem cell-related gene expression, we demonstrate the presence of stem-like tumor cells. Hypoxic culture conditions further increased CD138low stem-like cells with upregulated expression of OCT4 and NANOG. Compared to MM cells, these stem-like cells maintained lower steady-state pro-oxidant levels with increased uptake of the fluorescent deoxyglucose analog. In primary human MM samples, increased glycolytic gene expression correlated with poorer overall and event-free survival outcomes. Notably, stem-like cells showed increased mitochondrial mass, rhodamine 123 accumulation, and orthodox mitochondrial configuration while more condensed mitochondria were noted in the CD138high cells. Glycolytic inhibitor 2-deoxyglucose (2-DG induced ER stress as detected by qPCR (BiP, ATF4 and immunoblotting (BiP, CHOP and increased dihydroethidium probe oxidation both CD138low and CD138high cells. Treatment with a mitochondrial-targeting agent decyl-triphenylphosphonium (10-TPP increased intracellular steady-state pro-oxidant levels in stem-like and mature MM cells. Furthermore, 10-TPP mediated increases in mitochondrial oxidant production were suppressed by ectopic expression of manganese superoxide dismutase. Relative to 2-DG or 10-TPP alone, 2-DG plus 10-TPP combination showed increased caspase 3 activation in MM cells with minimal toxicity to the normal hematopoietic progenitor cells. Notably, treatment with polyethylene glycol conjugated catalase significantly reduced 2-DG and/or 10-TPP-induced apoptosis of MM cells. Also, the combination of 2-DG with 10-TPP decreased clonogenic survival of MM cells. Taken together, this study provides a novel strategy of metabolic oxidative stress-induced cytotoxicity of MM

Effect of intermolecular dipole-dipole interactions on interfacial supramolecular structures of C3-symmetric hexa-peri-hexabenzocoronene derivatives.

Science.gov (United States)

Mu, Zhongcheng; Shao, Qi; Ye, Jun; Zeng, Zebing; Zhao, Yang; Hng, Huey Hoon; Boey, Freddy Yin Chiang; Wu, Jishan; Chen, Xiaodong

2011-02-15

Two-dimensional (2D) supramolecular assemblies of a series of novel C(3)-symmetric hexa-peri-hexabenzocoronene (HBC) derivatives bearing different substituents adsorbed on highly oriented pyrolytic graphite were studied by using scanning tunneling microscopy at a solid-liquid interface. It was found that the intermolecular dipole-dipole interactions play a critical role in controlling the interfacial supramolecular assembly of these C(3)-symmetric HBC derivatives at the solid-liquid interface. The HBC molecule bearing three -CF(3) groups could form 2D honeycomb structures because of antiparallel dipole-dipole interactions, whereas HBC molecules bearing three -CN or -NO(2) groups could form hexagonal superstructures because of a special trimeric arrangement induced by dipole-dipole interactions and weak hydrogen bonding interactions ([C-H···NC-] or [C-H···O(2)N-]). Molecular mechanics and dynamics simulations were performed to reveal the physics behind the 2D structures as well as detailed functional group interactions. This work provides an example of how intermolecular dipole-dipole interactions could enable fine control over the self-assembly of disklike π-conjugated molecules.

Investigation of the deposition and thermal behavior of striped phases of unsymmetric disulfide self-assembled monolayers on Au(111): The case of 11-hydroxyundecyl decyl disulfide

Energy Technology Data Exchange (ETDEWEB)

Albayrak, Erol [Department of Materials and Metallurgical Engineering, Ahi Evran University, Kırşehir 40000 (Turkey); Karabuga, Semistan [Department of Chemistry, Kahramanmaraş Sütçü İmam University, Kahramanmaraş 46030 (Turkey); Bracco, Gianangelo [CNR-IMEM and Department of Physics, University of Genoa, via Dodecaneso 33, Genoa 16146 (Italy); Danışman, M. Fatih, E-mail: danisman@metu.edu.tr [Department of Chemistry, Middle East Technical University, Ankara 06800 (Turkey)

2015-01-07

Self-assembled monolayers (SAMs) of unsymmetric disulfides on Au(111) are used to form mixed SAMs that can be utilized in many applications. Here, we have studied 11-hydroxyundecyl decyl disulfide (CH{sub 3}–(CH{sub 2}){sub 9}–S–S–(CH{sub 2}){sub 11}–OH, HDD) SAMs produced by supersonic molecular beam deposition and characterized by He diffraction. The film growth was monitored at different temperatures up to a coverage which corresponds to a full lying down phase and the diffraction analysis shows that below 250 K the phase is different from the phase measured above 300 K. During the annealing of the film, two phase transitions were observed, at 250 K and 350 K. The overall data suggest that the former is related to an irreversible phase separation of HDD above 250 K to decanethiolate (–S–(CH{sub 2}){sub 9}–CH{sub 3}, DTT) and hydroxyundecylthiolate (–S–(CH{sub 2}){sub 11}–OH, MUDT), while the latter to a reversible melting of the film. Above 450 K, the specular intensity shows an increase related to film desorption and different chemisorbed states were observed with energies in the same range as observed for decanethiol (H–S–(CH{sub 2}){sub 9}–CH{sub 3}, DT) and mercaptoundecanol (H–S–(CH{sub 2}){sub 11}–OH, MUD) SAMs.

CFP1 Regulates Histone H3K4 Trimethylation and Developmental Potential in Mouse Oocytes

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Chao Yu

2017-08-01

Full Text Available Trimethylation of histone H3 at lysine-4 (H3K4me3 is associated with eukaryotic gene promoters and poises their transcriptional activation during development. To examine the in vivo function of H3K4me3 in the absence of DNA replication, we deleted CXXC finger protein 1 (CFP1, the DNA-binding subunit of the SETD1 histone H3K4 methyltransferase, in developing oocytes. We find that CFP1 is required for H3K4me3 accumulation and the deposition of histone variants onto chromatin during oocyte maturation. Decreased H3K4me3 in oocytes caused global downregulation of transcription activity. Oocytes lacking CFP1 failed to complete maturation and were unable to gain developmental competence after fertilization, due to defects in cytoplasmic lattice formation, meiotic division, and maternal-zygotic transition. Our study highlights the importance of H3K4me3 in continuous histone replacement for transcriptional regulation, chromatin remodeling, and normal developmental progression in a non-replicative system.

Reduction of 137caesium contamination in wild boars by supplementing offered food with ammonium-iron-hexa-cyanoferrate

International Nuclear Information System (INIS)

Morfeld, P.; Kienzle, E.

2014-01-01

This replication study investigated whether the 137 caesium ( 137 Cs) contamination of wild boars could be relevantly reduced under field conditions by adding ammonium-iron-hexa-cyanoferrate (AFCF; Prussian blue) to the food. In 285 wild boars that had been shot in six Bavarian hunting territories during the season (November until May) between 01 November 2010 and 10 December 2011 137 Cs contamination was analysed. Thirty-five animals originated from two hunting territories in which offered food had been supplemented with 1250 mg AFCF per kilogram food. The control animals showed a mean 137 Cs contamination of 522 Bq/kg lean skeletal muscle meat. Direct (univariable) comparisons of the two experimental territories with the four control territories yielded a mean reduction in 137 Cs contamination due to Prussian bluefeeding by -211 Bq/kg (p < 0.001). Multivariable mo dels that took potential confounders into account (age, weight, sex, hunting date, territory) estimated the effect to be -344 Bq/kg (p < 0.05). This replication study confirmed the finding of Kienzle et al. (12) who described a statistically significant reduction in 137 Cs contamination by -380 Bq/kg due to the feeding of Prussian blue in other territories. [de

Contribution to the coordination chemistry of penta, hexa and heptavalent ions of 5f elements

International Nuclear Information System (INIS)

Musikas, Claude.

1978-01-01

This report has two main parts in which are discussed results dealing with: - aquo and hydroxo complexes of penta, hexa and heptavalent ions of 5f elements - pseuso halides complexes of these ions (SCN - , N 3 - , CN - ). It has been shown, by spectrophotometric and electrochemical measurements that U (V) possesses an aquo ion more acid than the known UO 2 + ion. This form is observed as insoluble hydroxid near pH 3.0 or as soluble polynuclear hydroxo complexes at lower pH. Hydroxo anionic complexes of U (VI) have been observed and one can precise the mecanism of hydrolysis of UO 2 ++ ions beyond he hydroxid UO 2 (OH) 2 . At pH 9 to 12, polynuclear species with low negative charge have been observed. At pH 13, others OH - ions enter in the coordination sphere of UO 2 ++ and mononuclear species are obtained. Reduction of polynuclear species leads to mixed hydroxo complexes of 'blue type'. Studies of hydrolysis of NpO 2 + allow to propose an hydrolysis mechanism similar to UO 2 ++ one. With electrochemical methods that in acidic media Np (VII) is present as NpO 3 + ions. Solubility product of NpO 3 OH has been measured. The second part is devoted to pseudohalides complexes of UO 2 ++ , UO 2 + and NpO 2 + ions [fr

Regulatory Network Controlling Extracellular Proteins in Erwinia carotovora subsp. carotovora: FlhDC, the Master Regulator of Flagellar Genes, Activates rsmB Regulatory RNA Production by Affecting gacA and hexA (lrhA) Expression▿

OpenAIRE

Cui, Yaya; Chatterjee, Asita; Yang, Hailian; Chatterjee, Arun K.

2008-01-01

Erwinia carotovora subsp. carotovora produces an array of extracellular proteins (i.e., exoproteins), including plant cell wall-degrading enzymes and Harpin, an effector responsible for eliciting hypersensitive reaction. Exoprotein genes are coregulated by the quorum-sensing signal, N-acyl homoserine lactone, plant signals, an assortment of transcriptional factors/regulators (GacS/A, ExpR1, ExpR2, KdgR, RpoS, HexA, and RsmC) and posttranscriptional regulators (RsmA, rsmB RNA). rsmB RNA produc...

Promotion of the transdermal delivery of protein drugs by N-trimethyl chitosan nanoparticles combined with polypropylene electret.

Science.gov (United States)

Tu, Ye; Wang, Xinxia; Lu, Ying; Zhang, He; Yu, Yuan; Chen, Yan; Liu, Junjie; Sun, Zhiguo; Cui, Lili; Gao, Jing; Zhong, Yanqiang

We recently reported that electret, which was prepared by a corona charging system with polypropylene film, could enhance the transdermal delivery of several drugs of low molecular weight. The aim of this study was to investigate whether electret could enhance the transdermal delivery of protein drugs by N -trimethyl chitosan nanoparticles (TMC NPs) prepared by an ionic gelation method. A series of experiments were performed, including in vitro skin permeation assays and anti-inflammatory effects, to evaluate the transdermal delivery of protein drugs by TMC NPs in the presence of electret. The results showed that in the presence of electret, the transdermal delivery of protein drugs in TMC NPs was significantly enhanced, as demonstrated by in vitro permeation studies and confocal laser scanning microscopy. Notably, superoxide dismutase-loaded TMC NPs combined with electret exhibited the best inhibitory effect on the edema of the mouse ear. TMC NPs combined with electret represent a novel platform for the transdermal delivery of protein drugs.

Expanding the spectrum of HEXA mutations in Indian patients with Tay-Sachs disease.

Science.gov (United States)

Sheth, Jayesh; Mistri, Mehul; Datar, Chaitanya; Kalane, Umesh; Patil, Shekhar; Kamate, Mahesh; Shah, Harshuti; Nampoothiri, Sheela; Gupta, Sarita; Sheth, Frenny

2014-01-01

Tay-Sachs disease is an autosomal recessive neurodegenerative disorder occurring due to impaired activity of β-hexosaminidase-A (EC 3.2.1.52), resulting from the mutation in HEXA gene. Very little is known about the molecular pathology of TSD in Indian children except for a few mutations identified by us. The present study is aimed to determine additional mutations leading to Tay-Sachs disease in nine patients confirmed by the deficiency of β-hexosaminidase-A (C (D175A) and c.805G>C (p.G269R) in one case; and one small 1 bp deletion c.426delT (p.F142LfsX57) and one splice site mutation c.459+4A>C in the other two cases respectively. None of these mutations were detected in 100 chromosomes from healthy individuals of the same ethnic group. Three previously reported missense mutations, (i) c.532C>T (p.R178C), (ii) c.964G>T (p.D322Y), and (iii) c.1385A>T (p.E462V); two nonsense mutations (i) c.709C>T (p.Q237X) and (ii) c.1528C>T (p.R510X), one 4 bp insertion c.1277_1278insTATC (p.Y427IfsX5) and one splice site mutation c.459+5G>A were also identified in six cases. We observe from this study that novel mutations are more frequently observed in Indian patients with Tay-Sachs disease with clustering of ~ 73% of disease causing mutations in exons 5 to 12. This database can be used for a carrier rate screening in the larger population of the country.

Molecular orbital calculations for the formation of GaN layers on ultra-thin AlN/6H-SiC surface using alternating pulsative supply of gaseous trimethyl gallium (TMG) and NH sub 3

CERN Document Server

Seong, S Y

2001-01-01

The steps for the generation of very thin GaN films on ultrathin AlN/6H-SiC surface by alternating a pulsative supply (APS) of trimethyl gallium and NH sub 3 gases have been examined by ASED-MO calculations. We postulate that the gallium clusters was formed with the evaporation of CH sub 4 gases via the decomposition of trimethyl gallium (TMG), dimethyl gallium (DMG), and monomethyl gallium (MMG). During the injection of NH sub 3 gas into the reactor, the atomic hydrogens were produced from the thermal decomposition of NH sub 3 molecule. These hydrogen gases activated the Ga-C bond cleavage. An energetically stable GaN nucleation site was formed via nitrogen incorporation into the layer of gallium cluster. The nitrogen atoms produced from the thermal degradation of NH sub 3 were expected to incorporate into the edge of the gallium cluster since the galliums bind weakly to each other (0.19 eV). The structure was stabilized by 2.08 eV, as an adsorbed N atom incorporated into a tetrahedral site of the Ga cluster...

Spectrophotometric determination of some metal ions using hydrazones

International Nuclear Information System (INIS)

Mohammed, M. S.

2000-05-01

In this research many starting materials were prepared, like methyl salicylate and salicylic acid hydrazide from which different derivatives of hydrazones were synthesized by coupling with carbonyl compounds like benzil monoxime and benzil mono hydrazone which are prepared and others like salicylaldehyde and benzoin. The hydrazones that were synthesized are salicylaldehyde salicylic acid hydrazone, benzoin salicylic acid hydrazone, benzil mono hydrazone salicylic acid hydrazone and benzil monoxime salicylic acid hydrazone. These reagents were determined by different methods, IR spectrophotometric determination, the nitrogen content method and melting point determination. These hydrazones act as ligands for determination of some metal ions by making different coloured complexes that were prepared for eight hydrazones with eight metal ions U (VI), Fe (II), Fe (III), Co (II), V (II), Mo (VI), Ni (II) and Cu (II). These complexes were determined by ultraviolet and visible spectrophotometer (UV/VIS) to detect their absorbance and wavelengths (λ max). The two hydrazones salicylaldehyde salicylic acid-hydrazone and benzoin salicylic acid hydrazone, were selected for determination of five metal ions (Fe (II), Fe (III), U (VI), Ni (II) and Cu (II)), using two micelles sodium n-dodecyl sulphate and pyridinium hexa decyl bromide mono hydrate. Their absorbance and wavelengths were detected using UV/VIS spectrophotometer. (Author)

Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30, 1993

Energy Technology Data Exchange (ETDEWEB)

Somasundaran, P.

1994-07-01

The aim of this research project is to investigate mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy will be determined. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability; is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the first year of this three year contract, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Surfactants studied include alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amount of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed.

Preparation of poly(trimethyl-2-methacroyloxyethylammonium chloride-co-ethylene glycol dimethacrylate) monolith and its application in solid phase microextraction of brominated flame retardants.

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Yang, Ting-ting; Zhou, Lin-feng; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin; Chen, Hong-yuan

2013-05-24

A capillary poly(trimethyl-2-methacroyloxyethylammonium chloride-co-ethylene glycol dimethacrylate) monolith was in situ synthesized by thermally initiated free radical co-polymerization using trimethyl-2-methacroyloxyethylammonium chloride (MATE) and ethylene glycol dimethacrylate (EGDMA) as functional monomer and cross-linker, respectively. N,N-dimethylformamide and polyethylene glycol 6000 were used as solvent and porogen, respectively. The morphology and porous structure of the resulting monoliths were assessed by scanning electron microscope. In order to prepare practically useful poly(MATE-co-EGDMA) monoliths with low flow resistance and good mechanical strength, some parameters such as PEG-6000 to DMF ratio, total monomer to porogen ratio, and crosslinker to monomer ratio were optimized systematically. Moreover, the extraction mechanism was evaluated using two series of compounds, alkylbenzenes and weak acids, as model compounds on poly(MATE-co-EGDMA) monoliths as liquid chromatographic stationary phase. Finally, the monoliths were applied as the solid phase microextraction medium, and a simple off-line method for simultaneous determination of three brominated flame retardants, 2,4,6-tribromophenol (TBP), tetrabromobisphenol A (TBBPA) and 4,4'-dibrominated diphenyl ether (DBDPE), in environmental waters was developed by coupling the polymer monolith microextraction to HPLC with UV detection. The regression equations for these three brominated flame retardants showed good linearity from their limit of quantification to 5000ng/mL. The limits of detection were 0.20, 0.15 and 0.10ng/mL for TBP, TBBPA and DBDPE, respectively. The recovery of the proposed method was 78.7-106.1% with intra-day relative standard deviation of 1.3-4.4%. Copyright © 2013 Elsevier B.V. All rights reserved.

Recovery of Boron and Separation of Lithium from Uyuni Salar Brine using 2, 2, 4-Trimethyl -1, 3-Pentanediol (TPD)

International Nuclear Information System (INIS)

Kumar, Jyothi Rajesh; Kim, Chul-Joo; Yoon, Ho-Sung; Lee, Jin-Young; Kang, Dong-Jun

2015-01-01

In the present study, extraction and separation possibilities have been established for boron and lithium from Uyuni salar brine. Diols were shown to be effective extraction reagents for boron. The present scientific study was developed with 2, 2, 4-trimethyl-1, 3-pentanediol (TPD) as an extractant system. For fixing the diluent system, various diluents were tested and it was found that chloroform is a better diluent for boron extraction. Further, experimental studies on the extraction equilibrium time, pH influence, and phase ratio effects on boron extraction were conducted and the conditions for boron recovery and lithium separation were optimized. The McCabe Thiele diagram was established to optimize the number of extraction stages for boron extraction. Finally, stripping studies of boron from the loaded organic phase using various salts were performed.

Expanding the spectrum of HEXA mutations in Indian patients with Tay–Sachs disease

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Jayesh Sheth

2014-01-01

Full Text Available Tay–Sachs disease is an autosomal recessive neurodegenerative disorder occurring due to impaired activity of β-hexosaminidase-A (EC 3.2.1.52, resulting from the mutation in HEXA gene. Very little is known about the molecular pathology of TSD in Indian children except for a few mutations identified by us. The present study is aimed to determine additional mutations leading to Tay–Sachs disease in nine patients confirmed by the deficiency of β-hexosaminidase-A (C (D175A and c.805G>C (p.G269R in one case; and one small 1 bp deletion c.426delT (p.F142LfsX57 and one splice site mutation c.459+4A>C in the other two cases respectively. None of these mutations were detected in 100 chromosomes from healthy individuals of the same ethnic group. Three previously reported missense mutations, (i c.532C>T (p.R178C, (ii c.964G>T (p.D322Y, and (iii c.1385A>T (p.E462V; two nonsense mutations (i c.709C>T (p.Q237X and (ii c.1528C>T (p.R510X, one 4 bp insertion c.1277_1278insTATC (p.Y427IfsX5 and one splice site mutation c.459+5G>A were also identified in six cases. We observe from this study that novel mutations are more frequently observed in Indian patients with Tay–Sachs disease with clustering of ~73% of disease causing mutations in exons 5 to 12. This database can be used for a carrier rate screening in the larger population of the country.

Synthesis of 2D polymeric dicyanamide bridged hexa-coordinated Cu(II) complex: Structural characterization, spectral studies and TDDFT calculation

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Konar, Saugata; Saha, Urmila; Dolai, Malay; Chatterjee, Sudipta

2014-10-01

A rare 2D polymeric dicyanamide bridged hexa-coordinated copper(II) complex [Cu(L1‧)(μ1,5-dca)2]n (1) (L1‧ = 2-carboxypyrazine) has been synthesized from the reaction of Cu(NO3)2ṡ6H2O, 2-pyrazinecarbonitrile (L1) and sodium dicyanamide (Nadca) in methanolic medium. Single crystal X-ray analysis reveals that the complex has a 2D infinite zigzag chain structure in which copper(II) ions are bridged by single dicyanamide ligand in an end-to-end fashion. Such 2-carboxypyrazine can be obtained on the way of metal-assisted nitrile hydrolysis which well connected with Cu(NO3)2ṡ6H2O and dicyanamide (dca) to give rare 2D Cu(II) polymeric complex due to the flexibility in the coordination ability of the copper(II) ions within the polymeric chain. The geometry of the asymmetric unit of the complex was optimized in singlet state by DFT method with multilayer ONIOM model at doublet spin state accordance with repeating asymmetric unit only. The electronic spectrum of the complex is explained using TDDFT calculation.

Molecular structure of the discotic liquid crystalline phase of hexa-peri-hexabenzocoronene/oligothiophene hybrid and their charge transport properties

International Nuclear Information System (INIS)

Bag, Saientan; Maingi, Vishal; Maiti, Prabal K.; Yelk, Joe; Glaser, Matthew A.; Clark, Noel A.; Walba, David M.

2015-01-01

Using atomistic molecular dynamics simulation, we study the discotic columnar liquid crystalline (LC) phases formed by a new organic compound having hexa-peri-Hexabenzocoronene (HBC) core with six pendant oligothiophene units recently synthesized by Nan Hu et al. [Adv. Mater. 26, 2066 (2014)]. This HBC core based LC phase was shown to have electric field responsive behavior and has important applications in organic electronics. Our simulation results confirm the hexagonal arrangement of columnar LC phase with a lattice spacing consistent with that obtained from small angle X-ray diffraction data. We have also calculated various positional and orientational correlation functions to characterize the ordering of the molecules in the columnar arrangement. The molecules in a column are arranged with an average twist of 25° having an average inter-molecular separation of ∼5 Å. Interestingly, we find an overall tilt angle of 43° between the columnar axis and HBC core. We also simulate the charge transport through this columnar phase and report the numerical value of charge carrier mobility for this liquid crystal phase. The charge carrier mobility is strongly influenced by the twist angle and average spacing of the molecules in the column

Green synthesis of antimicrobial and antitumor N,N,N-trimethyl chitosan chloride/poly (acrylic acid)/silver nanocomposites.

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Abu Elella, Mahmoud H; Mohamed, Riham R; Abdel-Aziz, Marwa M; Sabaa, Magdy W

2018-05-01

The present study is imported to solve two critical problems we face in our daily life which are microbial pollution and colon cancer. One pot green synthesis of a water soluble polyelectrolyte complex (PEC) between cationic polysaccharide as N,N,N-trimethyl chitosan chloride (TMC) and anionic polymer as poly (acrylic acid) (PAA) in presence of silver nanoparticles to yield (TMC/PAA/Ag) nanocomposites with different Ag weight ratios. Structure of TMC, PAA and TMC/PAA (PEC) were proved via different analysis tools. TMC/PAA and its Ag nanocomposites are used as antimicrobial agents against different pathogenic bacteria and fungi to solve microbial pollution. TMC/PAA-Silver nanocomposites had the highest antimicrobial activity which increases with increasing Ag %. Cytotoxicity data confirmed also that TMC/PAA/Ag (3%) had the most cytotoxic effect (the less cell viability %) towards colon cancer. TMC/PAA (PEC) was formed through electrostatic interactions between N-quaternized (-N + R 3 ) groups in TMC and carboxylate (-COO - ) groups in PAA. Copyright © 2018 Elsevier B.V. All rights reserved.

Ethylene–propylene–diene terpolymer/hexa fluoropropylene–vinylidinefluoride dipolymer rubber blends: Thermal and mechanical properties

International Nuclear Information System (INIS)

Balachandran Nair, Ajalesh; Kurian, Philip; Joseph, Rani

2012-01-01

Highlights: ► The EPDM/MA-g-EPDM/FKM blends show good mechanical properties. ► In compatibilized blends, better thermal and swelling resistance was obtained. ► Random nucleation mechanism is the rate controlling process in degradation. ► Good phase morphology is obtained in the case of compatibilized blends. -- Abstract: Hexa fluoropropylene–vinylidinefluoride dipolymer, fluoroelastomer (FKM) and ethylene propylene diene rubber (EPDM) blends with and without compatibilizer (MA-g-EPDM) were prepared by two-roll mill mixing. The effects of blend ratio and amount of compatibilizer on mechanical properties and thermal stability were investigated. The cure characteristics and mechanical properties of EPDM, FKM and their blends of varying compositions were studied for unaged and aged samples. The 50:50 (w/w) FKM/EPDM showed highest mechanical properties. The tensile properties of all the composites, especially those with higher proportion of FKM increased with aging. Swelling of the blends was reduced after aging. The thermal stability of FKM/EPDM rubber blends was studied using thermogravimetric analysis (TGA). The incorporation of FKM rubber improved the thermal stability of EPDM rubber. The apparent degradation activation energy (E) of EPDM/FKM reactive blends was calculated by the Coats–Redfern method. The results showed that the EPDM/FKM reactive blends had higher thermal stability but lower E than FKM. The thermal degradation process of both EPDM/FKM reactive blends and FKM were determined by nucleation and growth mechanism. The differential scanning calorimetry (DSC) results suggest that glass transition temperature (T g ) peak for EPDM region is shifted to FKM phase, due to improved compatibility on addition of compatibilizer. The morphology of blends was investigated using scanning electron microscopy (SEM).

Synthesis, characterization, antimicrobial and anthelmentic activities of some metal complexes with a new Schiff base 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one

International Nuclear Information System (INIS)

Reddy, K. R. K; Mahendra, K.N.

2008-01-01

The complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), dioxouranium(VI), and Th(IV) with a new Schiff base, 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one formed by the condensation of isatin (Indole-2.3-dione) with isophoronediamine(5-amino-1,3,3-trimethyl-cyclohexane methylamine) were synthesized and characterized by microanalysis, conductivity, UV-visible, FT-IR, 1 H NMR, TGA, and magnetic susceptibility measurements. All the complexes exhibit 1: 1 metal to ligand ratio except for the dioxouranium(VI) and thorium(IV) complexes, where the metal: ligand stoichiometry is 1: 2. The spectral data revealed that the ligand acts as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen and carbonyl oxygen of the isatin moiety. Tetrahedral geometry for Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes, square planar geometry for Cu(II) complexes, and the coordination numbers 6 and 8 for UO 2 (VI) and Th(IV) complexes, respectively, are proposed. Both the ligand and the metal complexes were screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa, and the complexes are more potent bactericides than the ligand. The anthelmintic activity of the ligand and its complexes against earthworms was also investigated [ru

Drug permeability and mucoadhesion properties of thiolated trimethyl chitosan nanoparticles in oral insulin delivery.

Science.gov (United States)

Yin, Lichen; Ding, Jieying; He, Chunbai; Cui, Liming; Tang, Cui; Yin, Chunhua

2009-10-01

Trimethyl chitosan-cysteine conjugate (TMC-Cys) was synthesized in an attempt to combine the mucoadhesion and the permeation enhancing effects of TMC and thiolated polymers related to different mechanisms for oral absorption. TMC-Cys with various molecular weights (30, 200, and 500 kDa) and quaternization degrees (15 and 30%) was allowed to form polyelectrolyte nanoparticles with insulin through self-assembly, which demonstrated particle size of 100-200 nm, zeta potential of +12 to +18 mV, and high encapsulation efficiency. TMC-Cys/insulin nanoparticles (TMC-Cys NP) showed a 2.1-4.7-fold increase in mucoadhesion compared to TMC/insulin nanoparticles (TMC NP), which might be partly attributed to disulfide formation between TMC-Cys and mucin as evidenced by DSC measurement. Compared to insulin solution and TMC NP, TMC-Cys NP induced increased insulin transport through rat intestine by 3.3-11.7 and 1.7-2.6 folds, promoted Caco-2 cell internalization by 7.5-12.7 and 1.7-3.0 folds, and augmented uptake in Peyer's patches by 14.7-20.9 and 1.7-5.0 folds, respectively. Such results were further confirmed by in vivo experiment with the optimal TMC-Cys NP. Biocompatibility assessment revealed lack of toxicity of TMC-Cys NP. Therefore, self-assembled nanoparticles between TMC-Cys and protein drugs could be an effective and safe oral delivery system.

Non-covalently anchored multi-walled carbon nanotubes with hexa-decafluorinated zinc phthalocyanine as ppb level chemiresistive chlorine sensor

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Sharma, Anshul Kumar; Mahajan, Aman; Bedi, R. K.; Kumar, Subodh; Debnath, A. K.; Aswal, D. K.

2018-01-01

A cost effective solution assembly method has been explored for preparing zinc(II)1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexa-decafluoro-29H,31H-phthalocyanine/multi-walled carbon nanotubes (F16ZnPc/MWCNTs-COOH) hybrid. Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) investigations confirm the non-covalent anchoring of F16ZnPc onto MWCNTs-COOH through п-п stacking interactions. Further, a highly sensitive and selective chemiresistive Cl2 sensor has been fabricated using F16ZnPc/MWCNTs-COOH hybrid. The response of sensor is found to be 21.28% for 2 ppm of Cl2 with a response time of 14 s and theoretical detection limit of the sensor is found down to 0.06 ppb. The improved Cl2 sensing characteristics of hybrid are found to be originated from the synergetic interaction between F16ZnPc and MWCNTs-COOH. The underlying mechanism for improved gas sensing performance of F16ZnPc/MWCNTs-COOH sensor towards Cl2 has been explained using Raman, X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS) studies.

Gene silencing activity of siRNA polyplexes based on thiolated N,N,N-trimethylated chitosan.

Science.gov (United States)

Varkouhi, Amir K; Verheul, Rolf J; Schiffelers, Raymond M; Lammers, Twan; Storm, Gert; Hennink, Wim E

2010-12-15

N,N,N-Trimethylated chitosan (TMC) is a biodegradable polymer emerging as a promising nonviral vector for nucleic acid and protein delivery. In the present study, we investigated whether the introduction of thiol groups in TMC enhances the extracellular stability of the complexes based on this polymer and promotes the intracellular release of siRNA. The gene silencing activity and the cellular cytotoxicity of polyplexes based on thiolated TMC were compared with those based on the nonthiolated counterpart and the regularly used lipidic transfection agent Lipofectamine. Incubation of H1299 human lung cancer cells expressing firefly luciferase with siRNA/thiolated TMC polyplexes resulted in 60-80% gene silencing activity, whereas complexes based on nonthiolated TMC showed less silencing (40%). The silencing activity of the complexes based on Lipofectamine 2000 was about 60-70%. Importantly, the TMC-SH polyplexes retained their silencing activity in the presence of hyaluronic acid, while nonthiolated TMC polyplexes hardly showed any silencing activity, demonstrating their stability against competing anionic macromolecules. Under the experimental conditions tested, the cytotoxicity of the thiolated and nonthiolated siRNA complexes was lower than those based on Lipofectamine. Given the good extracellular stability and good silencing activity, it is concluded that polyplexes based on TMC-SH are attractive systems for further in vivo evaluations.

Transcriptome and H3K27 tri-methylation profiling of Ezh2-deficient lung epithelium

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Aliaksei Z. Holik

2015-09-01

Full Text Available The adaptation of the lungs to air breathing at birth requires the fine orchestration of different processes to control lung morphogenesis and progenitor cell differentiation. However, there is little understanding of the role that epigenetic modifiers play in the control of lung development. We found that the histone methyl transferase Ezh2 plays a critical role in lung lineage specification and survival at birth. We performed a genome-wide transcriptome study combined with a genome-wide analysis of the distribution of H3K27 tri-methylation marks to interrogate the role of Ezh2 in lung epithelial cells. Lung cells isolated from Ezh2-deficient and control mice at embryonic day E16.5 were sorted into epithelial and mesenchymal populations based on EpCAM expression. This enabled us to dissect the transcriptional and epigenetic changes induced by the loss of Ezh2 specifically in the lung epithelium. Here we provide a detailed description of the analysis of the RNA-seq and ChIP-seq data, including quality control, read mapping, differential expression and differential binding analyses, as well as visualisation methods used to present the data. These data can be accessed from the Gene Expression Omnibus database (super-series accession number GSE57393.

Molecular orbital calculations for the formation of GaN layers on ultra-thin AlN/6H-SiC surface using alternating pulsative supply of gaseous trimethyl gallium (TMG) and NH3

International Nuclear Information System (INIS)

Seong, See Yearl; Hwang, Jin Soo

2001-01-01

The steps for the generation of very thin GaN films on ultrathin AlN/6H-SiC surface by alternating a pulsative supply (APS) of trimethyl gallium and NH 3 gases have been examined by ASED-MO calculations. We postulate that the gallium clusters was formed with the evaporation of CH 4 gases via the decomposition of trimethyl gallium (TMG), dimethyl gallium (DMG), and monomethyl gallium (MMG). During the injection of NH 3 gas into the reactor, the atomic hydrogens were produced from the thermal decomposition of NH 3 molecule. These hydrogen gases activated the Ga-C bond cleavage. An energetically stable GaN nucleation site was formed via nitrogen incorporation into the layer of gallium cluster. The nitrogen atoms produced from the thermal degradation of NH 3 were expected to incorporate into the edge of the gallium cluster since the galliums bind weakly to each other (0.19 eV). The structure was stabilized by 2.08 eV, as an adsorbed N atom incorporated into a tetrahedral site of the Ga cluster. This suggests that the adhesion of the initial layer can be reinforced by the incorporation of nitrogen atom through the formation of large grain boundary GaN crystals at the early stage of GaN film growth

Interaction of PLGA and trimethyl chitosan modified PLGA nanoparticles with mixed anionic/zwitterionic phospholipid bilayers studied using molecular dynamics simulations

Science.gov (United States)

Novak, Brian; Astete, Carlos; Sabliov, Cristina; Moldovan, Dorel

2012-02-01

Poly(lactic-co-glycolic acid) (PLGA) is a biodegradable polymer. Nanoparticles of PLGA are commonly used for drug delivery applications. The interaction of the nanoparticles with the cell membrane may influence the rate of their uptake by cells. Both PLGA and cell membranes are negatively charged, so adding positively charged polymers such as trimethyl chitosan (TMC) which adheres to the PLGA particles improves their cellular uptake. The interaction of 3 nm PLGA and TMC-modified-PLGA nanoparticles with lipid bilayers composed of mixtures of phosphatidylcholine and phosphatidylserine lipids was studied using molecular dynamics simulations. The free energy profiles as function of nanoparticles position along the normal direction to the bilayers were calculated, the distribution of phosphatidylserine lipids as a function of distance of the particle from the bilayer was calculated, and the time scale for particle motion in the directions parallel to the bilayer surface was estimated.

Crystal water as the mol-ecular glue for obtaining different co-crystal ratios: the case of gallic acid tris-caffeine hexa-hydrate.

Science.gov (United States)

Vella-Zarb, L; Baisch, U

2018-04-01

The crystal structure of the hexa-hydrate co-crystal of gallic acid and caffeine, C 7 H 6 O 5 ·3C 8 H 10 N 4 O 2 ·6H 2 O or GAL3CAF·6H 2 O , is a remarkable example of the importance of hydrate water acting as structural glue to facilitate the crystallization of two components of different stoichiometries and thus to compensate an imbalance of hydrogen-bond donors and acceptors. The water mol-ecules provide the additional hydrogen bonds required to form a crystalline solid. Whereas the majority of hydrogen bonds forming the inter-molecular network between gallic acid and caffeine are formed by crystal water, only one direct classical hydrogen bond between two mol-ecules is formed between the carb-oxy-lic oxygen of gallic acid and the carbonyl oxygen of caffeine with d ( D ⋯ A ) = 2.672 (2) Å. All other hydrogen bonds either involve crystal water or utilize protonated carbon atoms as donors.

Controlled synthesis of N,N,N-trimethyl chitosan for modulated bioadhesion and nasal membrane permeability.

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Pardeshi, Chandrakantsing V; Belgamwar, Veena S

2016-01-01

In an experiment to explore the bioadhesion, biocompatibility, and membrane permeation properties, the controlled synthesis of N,N,N-trimethyl chitosan (TMC) was carried out by two-step reductive methylation of chitosan (CHT). Methylation was confirmed by (1)H NMR (δ=3.1 ppm) and FTIR analysis (CH stretch at 1,485 cm(-1)). The TMC was further characterized by DSC, TGA, XRD, HR-TEM, SEM, and elemental analysis. Findings revealed improved solubility, enhanced viscosity, increased swelling index and higher molecular weight of TMC over CHT. Comparative evaluation validated increased bioadhesion potential, and improved ex vivo biocompatibility of TMC compared to CHT. Increased bioadhesion of TMC NPs over CHT NPs can be attributed to the strong electrostatic interactions between cationic amino groups with anionic sialic and sulfonic acid moieties contained in the mucin of the nasal mucus. Ex vivo biocompatibility studies suggested that the NP formulations of both biopolymers were biocompatible and could be applied safely on the nasal epithelium. Ex vivo permeation studies executed on excised cattle nasal mucosa illustrated improved permeability of TMC NPs over CHT NPs. In the author's opinion, two-step reductive methylation of CHT could be an attractive strategy to improve its solubility, bioadhesion, and permeation characteristics without affecting biocompatibility across the mucosal surfaces. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and characterization of N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chloride for potential application in gene delivery.

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Xiao, Bo; Wan, Ying; Wang, Xiaoyu; Zha, Qichen; Liu, Haoming; Qiu, Zhiye; Zhang, Shengmin

2012-03-01

A series of N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chloride (HTCC) samples with various degrees of quaternization ranging from 12.4 to 43.7% was synthesized. The structures and properties of HTCC were investigated by FT-IR, (1)H NMR, conductometric titration and XRD analysis. It was found that HTCC had a more amorphous structure than chitosan. HTCC samples showed significantly lower cytotoxicity than polyethyleneimine in HepG2 and HeLa cell lines. The samples spontaneously formed complexes with pGL3 luciferase plasmid. These complexes had desirable particle sizes (160-300 nm) and zeta potentials (10.8-18.7 mV) when the weight ratios of HTCC to plasmid altered in the range of 3:1-20:1. In vitro gene transfection results indicated that HTCC had significantly high transfection efficiency compared with chitosan for delivering pGL3 luciferase plasmid to HeLa cells. The results suggest that HTCC could be a promising non-viral vector for safe and efficient DNA delivery. Copyright © 2011 Elsevier B.V. All rights reserved.

Cyclodextrin based ternary system of modafinil: Effect of trimethyl chitosan and polyvinylpyrrolidone as complexing agents.

Science.gov (United States)

Patel, Parth; Agrawal, Y K; Sarvaiya, Jayrajsinh

2016-03-01

Modafinil is an approved drug for the treatment of narcolepsy and have a strong market presence in many countries. The drug is widely consumed for off-label uses and currently listed as a restricted drug. Modafinil has very low water solubility. To enhance the aqueous solubility of modafinil by the formation of a ternary complex with Hydroxypropyl-β-cyclodextrin and two hydrophilic polymers was the main objective of the present study. Pyrrolidone (PVP K30) and a water soluble chitosan derivative, trimethyl chitosan (TMC) were studied by solution state and solid state characterization methods for their discriminatory efficiency in solubility enhancement of modafinil. Phase solubility study depicted the highest complexation efficiency (2.22) of cyclodextrin derivative in the presence of TMC compared to the same in the presence of PVP K30 (0.08) and in the absence of any polymer (0.92). FT-IR analysis of binary and ternary complex expressed comparable contribution of both polymers in formation of inclusion complex. The thermal behaviour of binary and ternary complex, involving individual polymers disclosed the influence of TMC on polymorphism of the drug. DSC study revealed efficiency of TMC to prevent conversion of metastable polymorphic form to stable polymorphic form. Ternary complex, involving TMC enhanced water solubility of the drug 1.5 times more compared to the binary complex of the drug whereas PVP K30 reduced the Solubility. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization and obtainment of thin films based on N,N,N-trimethyl chitosan and heparin through the technical layer-by-layer

International Nuclear Information System (INIS)

Martins, Alessandro F.; Follmann, Heveline D.M.; Rubira, Adley F.; Muniz, Edvani C.

2011-01-01

Thin films of Heparin (HP) and N,N,N-trimethyl chitosan (TMC) with a high degree of quaternization (DQ) were obtained at pH 7.4 through the layer-by-layer (LbL) technique. Polystyrene (PS) was oxidized with aqueous solution of sodium persulfate and subsequently employed as substrate. The characterization of TMC and the respective determination of DQ were performed through 1 H NMR spectroscopy. The thin films de TMC/HP were characterized by FTIR-ATR and AFM. Both techniques confirmed the adsorption of TMC and HP in surface of the PS. The increasing of the bilayers provides a decrease of the projections and/or roughness, further of minimizing the depressions at the surface of the films. Studies of thin films the base of TMC/HP prepared from the LbL technique has not been reported in the literature. It is expected that the thin films of TMC/HP present anti-adhesive and antimicrobial properties. (author)

Differences in relative amounts of two novel mutant HEXA transcripts in a juvenile TSD Druze patient

Energy Technology Data Exchange (ETDEWEB)

Drucker, L.; Navon, R. [Tel Aviv Univ. (Israel)]|[Sapir Medical Center, Kfar Sava (Israel)

1994-09-01

An Israeli-Druze patient with juvenile Tay-Sachs disease, born to first cousins, was found to be a compound heterozygote for two novel mutant HEXA alleles. SSCP analysis of the parents` genomic DNA revealed alterations in both exons 5 and 8. Direct sequencing showed a novel missense mutation T{sup 835}{r_arrow}C (Ser{sup 279}{r_arrow}Pro) in exon 8, of maternal origin. The mutant allele of paternal origin carried a novel double mutation in exon 5, (i) a C{sup 496} deletion, resulting in a frameshift and eventually a stop codon, (ii) a C{sup 496}{r_arrow}G transition which is a silent mutation. Both these latter mutations occur in the same codon. New restriction sites for ScrFI were introduced into the two mutant alleles, enabling rapid screening for their presence. In order to detect differences of the relative levels of the transcripts originating from the two mutant alleles, we applied allele-specific transcripts polymerase chain reaction (AST-PCR) to the RNA extractions prepared from the heterozygous parents (each carry a normal and mutant allele). In order to distinguish between the transcripts originating from the normal allele and those originating from each of the mutant alleles, the transcripts were digested by ScrFI. A severe depletion of the mRNA coded by the allele carrying the mutation in exon 5 was found. The phenomena corresponds with citations in the literature in cases of stop mutations. The allele carrying the transversion in exon 8, contrary to our expectations, also had a distinctly lower level of transcripts. The AST-PCR approach offers a molecular tool to study allele-specific gene expression in heterozygous individuals.

An assessment of different extraction and quantification methods of penta- and hexa-chlorobenzene from SRF fly-ash

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Dimitris E. Balampanis

2017-06-01

Full Text Available Highly chlorinated benzenes, produced in the presence of organic matter and chlorine, are considered PCDD/Fs precursors, and are used as cost and time convenient substitute indicators for the indirect measurement of the latter. In this study penta- and hexa-chlorobenzene are quantified for the determination of the organochloride load of fly ash from solid recovered fuel incineration. Some of the chlorobenzenes are formed under ‘de novo’ conditions, through heterogeneous (ash particles/flue gases reactions and are therefore deeply incorporated within fly ash. Accelerated solvent extraction (ASE and ultrasonic solvent extraction (USE, along with the equivalent clean-up methods suggested by literature were compared to traditional Soxhlet. The extraction efficiencies achieved were 83 ± 7.5% for Soxhlet, 111 ± 19% for PFE, and 67 ± 17% for ultrasonication. Soxhlet extraction and clean-up through a multilayer silica gel column gave more precise results compared to the other sample preparation methods. Furthermore, performance comparison of gas chromatography fitted with either a mass spectrometer operated in single ion monitoring mode (GC-MS-SIM, or electron capture detector (GC- ECD highlighted that ECD can be used for measuring chlorobenzenes traces down to 0.21 ng g−1, when the equivalent LOQ for MS-SIM was 3.26 ng g−1. The results further suggest that ECD can provide better peak integration than MS-SIM in the detection of chlorobenzenes in fly ash extracts, due to the detector's sensitivity to halogenated compounds.

Di-?-cyanido-tetra?cyanido(5,5,7,12,12,14-hexa?methyl-1,4,8,11-tetra?aza?cyclo?tetra?decane)[N-(quinolin-8-yl)quinoline-2-carboxamidato]diiron(III)nickel(II) 2.07-hydrate

OpenAIRE

Yang, Yuqi; Zhou, Hongbo; Shen, Xiaoping

2013-01-01

The asymmetric unit of the title complex, [Fe2Ni(C19H12N3O)2(CN)6(C16H36N4)]?2.07H2O, contains one [Fe(qcq)(CN)3]? anion, half a [Ni(teta)]2+ cation and two partially occupied inter?stitial water mol?ecules [qcq? is the N-(quinolin-8-yl)quinoline-2-carboxamidate anion and teta is 5,5,7,12,12,14-hexa?methyl-1,4,8,11-tetra?aza?cyclo?tetra?deca?ne]. In the complex mol?ecule, two [Fe(qcq)(CN)3]? anions additionally coordinate the central [Ni(teta)]2+ cation through cyanide groups in a trans mode,...

Cobalt-boron amorphous alloy prepared in water/cetyl-trimethyl-ammonium bromide/n-hexanol microemulsion as anode for alkaline secondary batteries

International Nuclear Information System (INIS)

Tong, D.G.; Wang, D.; Chu, W.; Sun, J.H.; Wu, P.

2010-01-01

Amorphous cobalt-boron (Co-B) with uniform nanoparticles was prepared for the first time via reduction of cobalt acetate by potassium borohydride in the water/cetyl-trimethyl-ammonium bromide/n-hexanol microemulsion system. The sample was characterized by X-ray diffraction, transmission electron microscopy, nitrogen adsorption-desorption, X-ray photoelectron spectroscopy, inductively coupled plasma, cyclic voltammetry, differential scanning calorimetry, temperature-programmed desorption, scanning electron microscopy, charge-discharge test and electrochemical impedance spectra. The results demonstrate that electrochemical activity of the as-synthesized Co-B was higher than that of the regular Co-B prepared in aqueous solution. It indicates that the homogeneous distribution and large specific surface area helped the electrochemical hydrogen storage of the as-synthesized Co-B. Furthermore, the as-synthesized Co-B even had 347 mAh g -1 after 50 cycles, while the regular Co-B prepared in aqueous solution only had 254 mAh g -1 after 30 cycles at a current of 100 mA g -1 . The better cycling performance can be ascribed to its smaller interfacial impedance between electrode and electrolyte.

(4bS,8aS-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthren-2-yl acetate

Directory of Open Access Journals (Sweden)

Radouane Oubabi

2014-03-01

Full Text Available The hemisynthesis of the title compound, C22H32O2, was carried out through direct acetylation reaction of the naturally occurring diterpene totarol [systematic name: (4bS,8aS-4b,8,8-trimethyl-1-propan-2-yl-5,6,7,8a,9,10-hexahydrophenanthren-2-ol]. The molecule is built up from three fused six membered rings, one saturated and two unsaturated. The central unsaturated ring has a half-chair conformation, whereas the other unsaturated ring displays a chair conformation. The absolute configuration is deduced from the chemical pathway. The value of the Hooft parameter [−0.10 (6] allowed this absolute configuration to be confirmed.

Differential regulation of the phosphorylation of Trimethyl-lysine27 histone H3 at serine 28 in distinct populations of striatal projection neurons

DEFF Research Database (Denmark)

Bonito-Oliva, Alessandra; Södersten, Erik; Spigolon, Giada

2016-01-01

Phosphorylation of histone H3 (H3) on serine 28 (S28) at genomic regions marked by trimethylation of lysine 27 (H3K27me3) often correlates with increased expression of genes normally repressed by Polycomb group proteins (PcG). We show that amphetamine, an addictive psychostimulant, and haloperidol...... of the protein phosphatase-1 inhibitor, dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32), reduces the phosphorylation of H3K27me3S28 produced by amphetamine and haloperidol. In contrast, knockout of the mitogen- and stress activated kinase 1 (MSK1), which is implicated in the phosphorylation...... of histone H3, decreases the effect of amphetamine, but not that of haloperidol. Chromatin immunoprecipitation analysis shows that amphetamine and haloperidol increase the phosphorylation of H3K27me3S28 at the promoter regions of Atf3, Npas4 and Lipg, three genes repressed by PcG. These results identify H3K...

No-carrier-added (NCA) synthesis of 6-[18F]fluoro-L-DOPA using 3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[6S-(6α, 8α, 8αβ)]-6,8-methano-2H-1,4-benzoxazin-2-one

International Nuclear Information System (INIS)

Horti, A.; Yale Univ., West Haven, CT; Redmond, D.E. Jr.; Soufer, R.

1995-01-01

3,5,6,7,8,8a-Hexahydro-7,7,8a-trimethyl-[6S-(6α,8α , 8αβ)]-6,8-methano-2H-1,4-benzoxazino-2-one (2) was investigated as chiral auxiliary for asymmetric NCA nucleophilic synthesis of 6-[ 18 F]Fluoro-L-DOPA. Direct condensation of 3,4-dimethoxy-2-[ 18 F]fluorobenzaldehyde (1a) or 6-[ 18 F]fluoro-piperonal (1b) in the presence of NaH with 2 gave the corresponding [ 18 F]-3-[(2-fluorophenyl)methylene]-3,5,6,7,8,8a-hexahydro-7,7,8 a-trimethyl-[6S-(3Z,3α,6α,8α,8αβ)]-6, 8-methano-2H-1,4-benzoxazin-2-one derivative 3a or 3b as a single stereoisomer. L-Selectride promoted hydrogenation of the olefinic double bond of these derivatives, in presence of tertbutyl alcohol, afforded the corresponding [ 18 F]-3-[(2-fluorophenyl) methyl]-3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[3S-(3α, 6α, 8α8αβ)]-6,8-methano-2H-1,4-benzoxazin-2-one derivatives (4a,b) without affecting the orientation of diasterofacial discrimination. Deprotection of the derivatives 4a,b yielded 6-[ 18 F]fluoro-L-DOPA (e.e. >90%, 3% radiochemical yield (EOB), total synthesis time 125 min, specific activity >2000 mCi/μmol). Direct deprotection/reduction of the compounds 3a,b provides the enantiomeric mixture of 6-[ 18 F]fluoro-D,L-DOPA (10-12% radiochemical yield) and, after chiral separation, 6-[ 18 F]fluoro-L-DOPA (e.e. 98%, 4-5% radiochemical yield). (author)

Molecular analysis of HEXA gene in Argentinean patients affected with Tay-Sachs disease: possible common origin of the prevalent c.459+5A>G mutation.

Science.gov (United States)

Zampieri, Stefania; Montalvo, Annalisa; Blanco, Mariana; Zanin, Irene; Amartino, Hernan; Vlahovicek, Kristian; Szlago, Marina; Schenone, Andrea; Pittis, Gabriela; Bembi, Bruno; Dardis, Andrea

2012-05-15

Tay-Sachs disease (TSD) is a recessively inherited disorder caused by the deficient activity of hexosaminidase A due to mutations in the HEXA gene. Up to date there is no information regarding the molecular genetics of TSD in Argentinean patients. In the present study we have studied 17 Argentinean families affected by TSD, including 20 patients with the acute infantile form and 3 with the sub-acute form. Overall, we identified 14 different mutations accounting for 100% of the studied alleles. Eight mutations were novel: 5 were single base changes leading to drastic residue changes or truncated proteins, 2 were small deletions and one was an intronic mutation that may cause a splicing defect. Although the spectrum of mutations was highly heterogeneous, a high frequency of the c.459+5G>A mutation, previously described in different populations was found among the studied cohort. Haplotype analysis suggested that in these families the c.459+5G>A mutation might have arisen by a single mutational event. Copyright © 2012 Elsevier B.V. All rights reserved.

Photocatalytic degradation of hexadecyl trimethyl ammonium chloride C/sub 19/H/sub 42/NCl

International Nuclear Information System (INIS)

Hassan, M.U.; Anwar, J.; Saif, M.J.

2008-01-01

Surfactants in the environment are a prerequisite for the sustainable development of human health and ecosystems. Surfactants are important in daily life in households as well as in industrial cleansing processes. It is important to have a detailed knowledge about their lifetime in the environment, their biodegradability in wastewater treatment plants and in natural waters, and their ecotoxicity. Most of the issues on environmental acceptability focus on the effects on the environment associated with the use and disposal of these surfactants. These effects are taken into account by a risk assessment. The first step in a risk assessment is an estimate of the concentrations of surf act ants in the environmental compartment of interest, such as wastewater treatment plant effluents, surface waters, sediments, and soils. This estimate is generated either by actual measurement or by prediction via modelling. The measured or predicted concentrations are then compared to the concentrations of surfactant known to be toxic to organisms living in these environmental compartments. There are many situations where industry is producing both heavy metals ions and organic pollutants, Successful treatment of effluents of this type to achieve legislative compliance will depend on whether the heavy metals effect the process of degradation of the organic species and whether the presence of organic molecules hinder the process of removal of heavy metals. Degradation of cationic surfactant was studied with a photolytic cell system. Compressed air was used as oxidant and the temperature was maintained at 25-30 degree C. Effect of UV source, hydrogen peroxide (H/sub 2/O/sub 2/) and titanium (TiO/sub 2/) on Hexadecyl trimethyl ammonium Chloride C/sub 19/H/sub 42/NCl were recorded. HPLC and IR were used to analyse to study the rate of degradation of C/sub 19/H/sub 42/NCl. (author)

Restraining Na-Montmorillonite Delamination in Water by Adsorption of Sodium Dodecyl Sulfate or Octadecyl Trimethyl Ammonium Chloride on the Edges

Directory of Open Access Journals (Sweden)

Hongliang Li

2016-08-01

Full Text Available The delamination of montmorillonite in water leads to sliming in ore slurry, which is detrimental to mineral flotation and solid/water separation. In this work, the delamination of Na-montmorillonite (Na-MMT has been restrained by sodium dodecyl sulfate (SDS or octadecyl trimethyl ammonium chloride (1831 through the adsorption on the edge of the mineral. The experimental results have shown that the pretreatment by adding SDS and 1831 could greatly reduce the Stokes size percentage of −1.1 µm particles in the aqueous Na-MMT suspension. From the X-ray diffractometer (XRD results, the interlayer spacing of the MMT pre-treated by SDS and 1831 is smaller than that of original MMT particles. Adsorption position of SDS and 1831 on MMT surfaces was analyzed by the measurements of adsorption capacity of SDS and 1831, inductively-coupled plasma spectra, and zeta potential before and after the plane surface of MMT was covered with tetraethylenepentaminecopper ([Cu(tetren]2+. The results indicated that SDS and 1831 are adsorbed on the edge and the whole surface of Na-MMT, respectively. Delamination of MMT could be well restrained by the adsorption of SDS and 1831 on the edges of MMT.

No-carrier-added (NCA) synthesis of 6-[{sup 18}F]fluoro-L-DOPA using 3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[6S-(6{alpha}, 8{alpha}, 8{alpha}{beta})]-6,8-methano-2H-1,4-benzoxazin-2-one

Energy Technology Data Exchange (ETDEWEB)

Horti, A. [Yale Univ., New Haven, CT (United States). School of Medicine]|[Yale Univ., West Haven, CT (United States). PET Center; Redmond, D.E. Jr. [Yale Univ., New Haven, CT (United States). School of Medicine; Soufer, R. [Yale Univ., West Haven, CT (United States). PET Center

1995-12-31

3,5,6,7,8,8a-Hexahydro-7,7,8a-trimethyl-[6S-(6{alpha},8{alpha} , 8{alpha}{beta})]-6,8-methano-2H-1,4-benzoxazino-2-one (2) was investigated as chiral auxiliary for asymmetric NCA nucleophilic synthesis of 6-[{sup 18}F]Fluoro-L-DOPA. Direct condensation of 3,4-dimethoxy-2-[{sup 18}F]fluorobenzaldehyde (1a) or 6-[{sup 18}F]fluoro-piperonal (1b) in the presence of NaH with 2 gave the corresponding [{sup 18}F]-3-[(2-fluorophenyl)methylene]-3,5,6,7,8,8a-hexahydro-7,7,8 a-trimethyl-[6S-(3Z,3{alpha},6{alpha},8{alpha},8{alpha}{beta})]-6, 8-methano-2H-1,4-benzoxazin-2-one derivative 3a or 3b as a single stereoisomer. L-Selectride promoted hydrogenation of the olefinic double bond of these derivatives, in presence of tertbutyl alcohol, afforded the corresponding [{sup 18}F]-3-[(2-fluorophenyl) methyl]-3,5,6,7,8,8a-hexahydro-7,7,8a-trimethyl-[3S-(3{alpha}, 6{alpha}, 8{alpha}8{alpha}{beta})]-6,8-methano-2H-1,4-benzoxazin-2-one derivatives (4a,b) without affecting the orientation of diasterofacial discrimination. Deprotection of the derivatives 4a,b yielded 6-[{sup 18}F]fluoro-L-DOPA (e.e. >90%, 3% radiochemical yield (EOB), total synthesis time 125 min, specific activity >2000 mCi/{mu}mol). Direct deprotection/reduction of the compounds 3a,b provides the enantiomeric mixture of 6-[{sup 18}F]fluoro-D,L-DOPA (10-12% radiochemical yield) and, after chiral separation, 6-[{sup 18}F]fluoro-L-DOPA (e.e. 98%, 4-5% radiochemical yield). (author).

Study of radiation induced grafting of [(methacryloylamino)-propyl] trimethyl ammonium chlorite (MPTAC) on to cotton fabrics and its application

International Nuclear Information System (INIS)

Selambakkannu, S.

2014-01-01

Quaternary ammonium salt, [(methacryloylamino)-propyl] trimethyl ammonium chlorite (MPTAC) had been used as monomer in mutual radiation grafting process on cotton fabrics with the aid of high energy gamma radiation source. The polymer chains of MPTAC were successfully grafted covalently onto cotton fabrics. Effect of selected experimental variables such as irradiation dose, monomer concentration, and ambient conditions and effect of inhibitors on extent of grafting had been analyzed. Grafting yield increases steadily with monomer concentration. The highest grafting yield obtained at 2 kGy and reduces thereafter then become almost constant at higher dose range. The grafted samples characterized for its surface morphology. Finally the grafted cotton subjected to its dye uptake capacity and antibacterial efficacy. The grafted cotton fiber was used in absorption studies of aqueous basic dye solution, namely AB74. The grafted cotton posses very good dye uptake capacity. The maximum dye uptake capacity of the grafted cotton sample was 150 mg/g. Antibacterial efficacy has been tested by qualitative and quantitative methods against model bacteria S. aureus and E. coli from gram positive and gram negative respectively. 20 % grafted cotton was found to be responsible of 2 log cycle reductions for the E.coli and S.aureus colonies. (author)

Adsorption and desorption of carbaryl on hexadecyl trimethyl ammonium bromide modified zeolite NaY using RGB portable photometer

Science.gov (United States)

Patdhanagul, Nopbhasinthu; Chanpaka, Saiphon; Intharaksa, Orapan; Sirival, Rujikarn; Thanomsith, Kannikar; Wongkwanklom, Sarayuth

2018-04-01

The carbaryl adsorption-desorption isotherms of zeolite NaY and hexadecyl trimethyl ammonium bromide (HTAB) modified zeolite NaY were investigated. Zeolite NaY was synthesized and modified by HTAB in the concentration range 0.1 - 10.0 mM. The adsorption isotherms indicated that zeolite modified with HTAB could significantly enhance the carbaryl adsorption capacity. Zeolite NaY modified with 5.0 mM HTAB gave great carbaryl adsorption because of hydrophilic surface. The 5.0 mM HTAB could adsorb up to 145.75 ppm g-1 of carbaryl which was equivalent to a 36.7% increase. The Surface area characterization showed the remaining of pore volume and pore size diameter and external surface area whereas the BET surface area and micropore surface area of modified zeolite slightly decreased. The XRD results indicate that modification of zeolite NaY with HTAB does not change the crystallinity of the starting zeolite. The elemental analysis indicated that the Si/Al ratio of synthesized zeolite NaY was close to 2.43. Desorption of carbaryl was tested by organic solvents such as methanol, ethanol, tetrahydrofuran, hexane and Deionized water. The results demonstrated that the percentage desorption of methanol is the highest. Carbaryl was quantitatively desorbed with percentage desorption of 82-100 %. It indicated sorption mechanism of carbaryl on the modified sorbent which was principally driven by hydrophobic forces.

Murine Sialidase Neu3 facilitates GM2 degradation and bypass in mouse model of Tay-Sachs disease.

Science.gov (United States)

Seyrantepe, Volkan; Demir, Secil Akyildiz; Timur, Zehra Kevser; Von Gerichten, Johanna; Marsching, Christian; Erdemli, Esra; Oztas, Emin; Takahashi, Kohta; Yamaguchi, Kazunori; Ates, Nurselin; Dönmez Demir, Buket; Dalkara, Turgay; Erich, Katrin; Hopf, Carsten; Sandhoff, Roger; Miyagi, Taeko

2018-01-01

Tay-Sachs disease is a severe lysosomal storage disorder caused by mutations in Hexa, the gene that encodes for the α subunit of lysosomal β-hexosaminidase A (HEXA), which converts GM2 to GM3 ganglioside. Unexpectedly, Hexa -/- mice have a normal lifespan and show no obvious neurological impairment until at least one year of age. These mice catabolize stored GM2 ganglioside using sialidase(s) to remove sialic acid and form the glycolipid GA2, which is further processed by β-hexosaminidase B. Therefore, the presence of the sialidase (s) allows the consequences of the Hexa defect to be bypassed. To determine if the sialidase NEU3 contributes to GM2 ganglioside degradation, we generated a mouse model with combined deficiencies of HEXA and NEU3. The Hexa -/- Neu3 -/- mice were healthy at birth, but died at 1.5 to 4.5months of age. Thin-layer chromatography and mass spectrometric analysis of the brains of Hexa -/- Neu3 -/- mice revealed the abnormal accumulation of GM2 ganglioside. Histological and immunohistochemical analysis demonstrated cytoplasmic vacuolation in the neurons. Electron microscopic examination of the brain, kidneys and testes revealed pleomorphic inclusions of many small vesicles and complex lamellar structures. The Hexa -/- Neu3 -/- mice exhibited progressive neurodegeneration with neuronal loss, Purkinje cell depletion, and astrogliosis. Slow movement, ataxia, and tremors were the prominent neurological abnormalities observed in these mice. Furthermore, radiographs revealed abnormalities in the skeletal bones of the Hexa -/- Neu3 -/- mice. Thus, the Hexa -/- Neu3 -/- mice mimic the neuropathological and clinical abnormalities of the classical early-onset Tay-Sachs patients, and provide a suitable model for the future pre-clinical testing of potential treatments for this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of cyclic, low dose pyrimethamine treatment in patients with Late Onset Tay Sachs: an open label, extended pilot study.

Science.gov (United States)

Osher, Etty; Fattal-Valevski, Aviva; Sagie, Liora; Urshanski, Nataly; Sagiv, Nadav; Peleg, Leah; Lerman-Sagie, Tally; Zimran, Ari; Elstein, Deborah; Navon, Ruth; Valevski, Avi; Stern, Naftali

2015-04-17

Late Onset Tay- Sachs disease (LOTS) is a rare neurodegenerative lysosomal storage disease which results from mutations in the gene encoding the α subunit (HEXA) of β-hexosaminidase enzyme (HexA). At the present time, no effective treatment exists for LOTS and other neurodegenerative diseases involving the central nerve system (CNS). Pyrimethamine (PMT) was previously shown to act as a HexA chaperone in human fibroblasts in vitro carrying some (e.g., αG269S), but not all LOTS-related mutations. The present study assessed the effect of cyclic, low dose and long term pyrimethamine treatment on HexA in subjects with LOTS. In an open label trial in 4 LOTS patients, PMT was initiated at an average daily dose of ~2.7 mg and administered cyclically guided by blood lymphocyte HexA activity for a mean duration of 82.8 (±22.5; SD) weeks (~1.5 year). HexA activity rose in all subjects, with a mean peak increase of 2.24 folds (±0.52; SD) over baseline activity (range 1.87-3). The mean treatment time required to attain this peak was of 15.7 (±4.8; SD) weeks. Following increase in activity, HexA gradually declined with the continued use of PMT, which was then stopped, resulting in the return of HexA activity to baseline. A second cycle of PMT treatment was then initiated, resulting again in an increase in HexA activity. Three of the patients experienced a measurable neuropsychiatric deterioration whereas one subject remained entirely stable. Cyclic low dose of PMT can increase HexA activity in LOTS patients. However, the observed increase is repeatedly transient and not associated with discernible beneficial neurological or psychiatric effects.

Análise estática e dinâmica, linear e não-linear geométrica, através de elementos hexaédricos de oito nós com um ponto de integração

OpenAIRE

Luiz Alberto Duarte Filho

2002-01-01

Para a análise estática e dinâmica, linear e não-linear de placas, cascas e vigas, implementa-se neste trabalho o elemento hexaédrico com integração reduzida, livre de travamento volumétrico e travamento de cisalhamento e que não apresenta modos espúrios. Na formulação do elemento, utiliza-se apenas um ponto de integração. Desta forma, a matriz de rigidez é dada de forma explícita e o tempo computacional é significativamente reduzido, especialmente em análise não-linear. Os modos espúrios são...

Trimethyl Chitosan Nanoparticles Encapsulated Protective Antigen Protects the Mice Against Anthrax

Directory of Open Access Journals (Sweden)

Anshu Malik

2018-03-01

Full Text Available Anthrax is an era old deadly disease against which there are only two currently available licensed vaccines named anthrax vaccine adsorbed and precipitated (AVP. Though they can provide a protective immunity, their multiple side-effects owing to their ill-defined composition and presence of toxic proteins (LF and EF of Bacillus anthracis, the causative organism of anthrax, in the vaccine formulation makes their widespread use objectionable. Hence, an anthrax vaccine that contains well-defined and controlled components would be highly desirable. In this context, we have evaluated the potential of various vaccine formulations comprising of protective antigen (PA encapsulated trimethyl-chitosan nanoparticles (TMC-PA in conjunction with either CpG-C ODN 2395 (CpG or Poly I:C. Each formulation was administered via three different routes, viz., subcutaneous (SC, intramuscular (IM, and intraperitoneal in female BALB/c mice. Irrespective of the route of immunization, CpG or Poly I:C adjuvanted TMC-PA nanoparticles induced a significantly higher humoral response (total serum IgG and its isotypes viz., IgG1, IgG2a, and IgG2b, compared to their CpG or Poly I:C PA counterparts. This clearly demonstrates the synergistic behavior of CpG and Poly I:C with TMC nanoparticles. The adjuvant potential of TMC nanoparticles could be observed in all the three routes as the TMC-PA nanoparticles by themselves induced IgG titers (1–1.5 × 105 significantly higher than both CpG PA and Poly I:C PA groups (2–8 × 104. The effect of formulations on T-helper (Th cell development was assessed by quantifying the Th1-dependant (TNF-α, IFN-γ, and IL-2, Th2-dependant (IL-4, IL-6, and IL-10, and Th17-type (IL-17A cytokines. Adjuvanation with CpG and Poly I:C, the TMC-PA nanoparticles triggered a Th1 skewed immune response, as suggested by an increase in the levels of total IgG2a along with IFN-γ cytokine production. Interestingly, the TMC-PA group showed a Th2-biased

Preparing photochromic nanofibers and animal cells using a photochromic compound of 1′,3′,3′-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2′-indoline)

DEFF Research Database (Denmark)

Li, Xiaoqiang; Lin, Lin; Kanjwal, Muzafar Ahmed

2012-01-01

In this work, the photochromic compound 1′,3′,3′-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2′-indoline) (NOSP) was synthesized by a two step process. The photochromic properties of NOSP were investigated by ultraviolet–visible (UV–Vis) spectrophotometry. The results showed that NOSP was very...... electrospinning were characterized by water contact angle measurements, ultraviolet–visible (UV–Vis) spectrophotometry and fluorescence microscopy. Morphology of photochromic PIEC was observed by fluorescence microscopy after being irradiated. It was shown that nanofibers from electrospun polymers and NOSP...... sensitive to UV irradiation with absorption peaks at about 336nm and 567nm. Our hypothesis was that both photochromic nanofibers and photochromic living animal cells could be obtained by combining them with NOSP. To test the hypothesis, photochromic nanofibers were fabricated by electrospinning from various...

Thermochemistry of organic azides revisited

International Nuclear Information System (INIS)

Emel'yanenko, Vladimir N.; Algarra, Manuel; Esteves da Silva, Joaquim C.G.; Hierrezuelo, Jesús; López-Romero, Juan M.; Verevkin, Sergey P.

2014-01-01

Highlights: • Pure samples of 4-nitro-phenyl azide, 1-octyl- and 1-decyl-azides were prepared. • Vapour pressures, sublimation and vaporization enthalpies measured by transpiration. • Enthalpy of formation of 1-alkyl azides measured by combustion calorimetry. • Enthalpy of fusion of 4-nitro-phenyl azide measured by DSC. • Experimental gas enthalpies of formation were in agreement with calculated by G4. - Abstract: Highly pure samples of 4-nitro-phenyl azide, 1-octyl azide and 1 decyl-azide were prepared for thermochemical studies. Vapour pressures over the solid and the liquid sample of 4-nitro-phenyl azide have been determined by the transpiration method. The molar enthalpies of vaporization/sublimation for this compound were derived from the temperature dependencies of vapour pressures. The molar enthalpy of fusion of 4-nitro-phenyl azide was measured by DSC. The measured data set for 4-nitro-phenyl azide was successfully checked for internal consistency. Molar enthalpies of vaporization of 1-octyl azide and 1 decyl-azide were measured by transpiration. The molar enthalpies of formation of the liquid 1-octyl azide and 1 decyl-azides were derived from the combustion calorimetry. New experimental results for these organic azides have been used to derive their molar enthalpies of formation in the gas state and for comparison with results from quantum-chemical method G4

The colorimetric detection of Pb2+ by using sodium thiosulfate and hexadecyl trimethyl ammonium bromide modified gold nanoparticles.

Science.gov (United States)

Zhang, Yujie; Leng, Yumin; Miao, Lijing; Xin, Junwei; Wu, Aiguo

2013-04-21

A simple, rapid colorimetric detection method for Pb(2+) in aqueous solution has been developed by using sodium thiosulfate (Na2S2O3) and hexadecyl trimethyl ammonium bromide (CTAB) modified gold nanoparticles (Au NPs). Na2S2O3 was added into the Au NP solution and thiosulfate ions (S2O3(2-)) were adsorbed on the surface of the Au NPs due to electrostatic interactions. Au atoms on the surface of the Au NPs were then oxidized to Au(i) by the O2 that existed in the solution in presence of thiosulfate. The addition of Pb(2+) (the final concentration was lower than 10 μM), accelerated the leaching of the Au NPs, and Pb-Au alloys also formed on the surface of the Au NPs. There was an obvious decrease in the surface plasmon resonance (SPR) absorption of the Au NPs. The lowest concentration for Pb(2+) that could be detected by the naked eye was 0.1 μM and using UV-vis spectroscopy was 40 nM. This is lower than the lead toxic level defined by the US Environmental Protection Agency (US EPA), which is 75 nM. In this method, CTAB, as a stabilizing agent for Au NPs, can accelerate the adsorption of S2O3(2-) on the surface of the Au NPs, which shortened the detection time to within 30 min. Moreover, this detection method is simple, cheap and environmentally friendly.

Roles of oxygen radicals and elastase in citric acid-induced airway constriction of guinea-pigs

OpenAIRE

Lai, Y -L; Chiou, W -Y; Lu, F J; Chiang, L Y

1999-01-01

Antioxidants attenuate noncholinergic airway constriction. To further investigate the relationship between tachykinin-mediated airway constriction and oxygen radicals, we explored citric acid-induced bronchial constriction in 48 young Hartley strain guinea-pigs, divided into six groups: control; citric acid; hexa(sulphobutyl)fullerenes+citric acid; hexa(sulphobutyl)fullerenes+phosphoramidon+citric acid; dimethylthiourea (DMTU)+citric acid; and DMTU+phosphoramidon+citric acid. Hexa(sulphobutyl...

Development of Nanofluids as Lubricant to Study Friction and Wear Behavior of Stainless Steels

Science.gov (United States)

Sahoo, Rashmi Ranjan; Bhattacharjee, Santu; Das, Tuhin

A number of nanofluids have been prepared to study the effect of lubrication properties of nanofluids on stainless steels taking Kaolin and Boron Nitride (BN) as the lubricant particles and Sodium Dodecyl Sulfate (SDS), Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Hexa Meta Phosphate (SHMP) as dispersants in the same liquid medium i.e. water. A pin on disc tribometer is being used to access the tribological behaviour of the prepared nanofluids. The particle size of these particle dispersions are examined with a nanoparticle size analyzer. It has been found that the use of dispersants significantly control the particle size and tribological behavior of the nanofluids as for Boron Nitride particle with Sodium Dodecyl Sulfate (SDS) as dispersant has got a very low value of coefficient of friction being equal to 0.142 while without dispersant the value is 0.498. Similarly, in case of Kaolin water with SDS as dispersant the value of coefficient of friction obtained is 0.161 and without dispersant it is 0.333. Sodium Dodecyl Sulfate (SDS) as dispersant has resulted a very low coefficient of friction compared to other dispersants tested even though it doesn’t always assure a least particle size. The role of SDS in yielding the lowest friction has pursued significant attention for further investigation.

Mono-, di- and trimethylated homologues of isoprenoid tetraether lipid cores in archaea and environmental samples: mass spectrometric identification and significance.

Science.gov (United States)

Knappy, Chris; Barillà, Daniela; Chong, James; Hodgson, Dominic; Morgan, Hugh; Suleman, Muhammad; Tan, Christine; Yao, Peng; Keely, Brendan

2015-12-01

Higher homologues of widely reported C(86) isoprenoid diglycerol tetraether lipid cores, containing 0-6 cyclopentyl rings, have been identified in (hyper)thermophilic archaea, representing up to 21% of total tetraether lipids in the cells. Liquid chromatography-tandem mass spectrometry confirms that the additional carbon atoms in the C(87-88) homologues are located in the etherified chains. Structures identified include dialkyl and monoalkyl ('H-shaped') tetraethers containing C(40-42) or C(81-82) hydrocarbons, respectively, many representing novel compounds. Gas chromatography-mass spectrometric analysis of hydrocarbons released from the lipid cores by ether cleavage suggests that the C(40) chains are biphytanes and the C(41) chains 13-methylbiphytanes. Multiple isomers, having different chain combinations, were recognised among the dialkyl lipids. Methylated tetraethers are produced by Methanothermobacter thermautotrophicus in varying proportions depending on growth conditions, suggesting that methylation may be an adaptive mechanism to regulate cellular function. The detection of methylated lipids in Pyrobaculum sp. AQ1.S2 and Sulfolobus acidocaldarius represents the first reported occurrences in Crenarchaeota. Soils and aquatic sediments from geographically distinct mesotemperate environments that were screened for homologues contained monomethylated tetraethers, with di- and trimethylated structures being detected occasionally. The structural diversity and range of occurrences of the C(87-89) tetraethers highlight their potential as complementary biomarkers for archaea in natural environments. Copyright © 2015 John Wiley & Sons, Ltd.

Molecular restrictions for human eye irritation by chemical vapors

International Nuclear Information System (INIS)

Cometto-Muniz, J. Enrique; Cain, William S.; Abraham, Michael H.

2005-01-01

Previous research showed a cut-off along homologous volatile organic compounds (VOCs) in their ability to produce acute human mucosal irritation. The present study sought to specify the particular cut-off homolog for sensory eye irritation in an acetate and n-alcohol series. A 1900-ml glass vessel system and a three-alternative forced-choice procedure served to test nonyl, decyl, and dodecyl acetate, and 1-nonanol, 1-decanol, and 1-undecanol. Flowrate to the eye ranged from 2 to 8 L/min and time of exposure from 3 to 24 s. Decyl acetate and 1-undecanol were the shortest homologs that failed to produce eye irritation under all conditions, producing a cut-off effect. Increasing the vapor concentration of decyl acetate and 1-undecanol by 3 and 8 times, respectively, via heating them to 37 deg C made either or both VOCs detectable to only half of the 12 subjects tested, even though the higher vapor concentration was well above a predicted eye irritation threshold. When eye irritation thresholds for homologous acetates and n-alcohols were plotted as a function of the longest unfolded length of the molecule, the values for decyl acetate and 1-undecanol fell within a restricted range of 18 to 19 A. The outcome suggests that the basis for the cut-off is biological, that is, the molecule lacks a key size or structure to trigger transduction, rather than physical, that is, the vapor concentration is too low to precipitate detection

Transcription factor 19 interacts with histone 3 lysine 4 trimethylation and controls gluconeogenesis via the nucleosome-remodeling-deacetylase complex.

Science.gov (United States)

Sen, Sabyasachi; Sanyal, Sulagna; Srivastava, Dushyant Kumar; Dasgupta, Dipak; Roy, Siddhartha; Das, Chandrima

2017-12-15

Transcription factor 19 (TCF19) has been reported as a type 1 diabetes-associated locus involved in maintenance of pancreatic β cells through a fine-tuned regulation of cell proliferation and apoptosis. TCF19 also exhibits genomic association with type 2 diabetes, although the precise molecular mechanism remains unknown. It harbors both a plant homeodomain and a forkhead-associated domain implicated in epigenetic recognition and gene regulation, a phenomenon that has remained unexplored. Here, we show that TCF19 selectively interacts with histone 3 lysine 4 trimethylation through its plant homeodomain finger. Knocking down TCF19 under high-glucose conditions affected many metabolic processes, including gluconeogenesis. We found that TCF19 overexpression represses de novo glucose production in HepG2 cells. The transcriptional repression of key genes, induced by TCF19, coincided with NuRD (nucleosome-remodeling-deacetylase) complex recruitment to the promoters of these genes. TCF19 interacted with CHD4 (chromodomain helicase DNA-binding protein 4), which is a part of the NuRD complex, in a glucose concentration-independent manner. In summary, our results show that TCF19 interacts with an active transcription mark and recruits a co-repressor complex to regulate gluconeogenic gene expression in HepG2 cells. Our study offers critical insights into the molecular mechanisms of transcriptional regulation of gluconeogenesis and into the roles of chromatin readers in metabolic homeostasis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Impact of flavouring substances on the aggregation behaviour of dissolved barley β-glucans in a model beer.

Science.gov (United States)

Kupetz, M; Sacher, B; Becker, T

2016-06-05

Structural polymers such as cereal β-glucan may cause various processing problems in beverage industry depending on concentration, molar size distribution and agglomeration behaviour. In this context, influences of the beer volatiles dodecanoic acid, octyl butanoate, ethyl decanoate and decyl acetate on molar mass and radii of barley β-glucan were investigated in ethanolic (4% w/w) model solution. After addition of 100mg/l ethyl decanoate and decyl acetate to the β-glucan solution, a wider-ranging molar mass distribution could be observed by means of asymmetric field-flow-fractionation. Due to agglomeration, average molar mass of β-glucan standard (MW=6.8×10(6)g/mol) increased by 2×10(6)g/mol (P<0.05) in solution containing decyl acetate. Furthermore, a significant growth (P<0.05) from 86 to 102 nm in gyration radius was measured. The obtained results elucidate the importance of fatty acid derived flavouring substance composition in beer regarding the aggregation behaviour of β-glucan. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular and electronic structure of actinide hexa-cyanoferrates; Structure moleculaire et electronique des hexacyanoferrates d'actinides

Energy Technology Data Exchange (ETDEWEB)

Bonhoure, I

2001-07-01

The goal of this work is to improve our knowledge on the actinide-ligand bond properties. To this end, the hexacyanoferrate entities have been used as pre-organized ligand. We have synthesized, using mild chemistry, the following series of complexes: An{sup IV}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Th, U, Np, Pu); Am{sup III}[Fe{sup III}(CN){sub 6}].xH{sub 2}O; Pu {sup III}[Co{sup III}(CN){sub 6}].xH{sub 2}O and K(H?)An{sup III}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Pu, Am). The metal oxidation states have been obtained thanks to the {nu}{sub CN}, stretching vibration and to the actinide L{sub III} absorption edge studies. As Prussian Blue, the An{sup IV}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Np, Pu) are class II of Robin and Day compounds. X-ray Diffraction has shown besides that these complexes crystallize in the P6{sub 3}/m space group, as the isomorphic LaKFe(CN){sub 6}.4H{sub 2}O complex used as structural model. The EXAFS oscillations at the iron K edge and at the An L{sub III} edge allowed to determine the An-N, An-O, Fe-C and Fe-N distances. The display of the multiple scattering paths for both edges explains the actinide contribution absence at the iron edge, whereas the iron signature is present at the actinide edge. We have shown that the actinide coordination sphere in actinides hexa-cyanoferrates is comparable to the one of lanthanides. However, the actinides typical behavior towards the lanthanides is brought to the fore by the An{sup IV} versus Ln{sup III} ions presence in this family of complexes. Contrarily to the 4f electrons, the 5f electrons influence the electronic properties of the compounds of this family. However, the gap between the An-N and Ln-N distances towards the corresponding metals ionic radii do not show any covalence bond evolution between the actinide and lanthanide series. (author)

Late onset Tay-Sachs disease in mice with targeted disruption of the Hexa gene: behavioral changes and pathology of the central nervous system.

Science.gov (United States)

Miklyaeva, Elena I; Dong, Weijia; Bureau, Alexandre; Fattahie, Roya; Xu, Yongqin; Su, Meng; Fick, Gordon H; Huang, Jing-Qi; Igdoura, Suleiman; Hanai, Nobuo; Gravel, Roy A

2004-03-19

Tay-Sachs disease is an autosomal recessive neurodegenerative disease resulting from a block in the hydrolysis of GM2 ganglioside, an intermediate in ganglioside catabolism. The mouse model of Tay-Sachs disease (Hexa -/-) has been described as behaviorally indistinguishable from wild type until at least 1 year of age due to a sialidase-mediated bypass of the metabolic defect that reduces the rate of GM2 ganglioside accumulation. In this study, we have followed our mouse model to over 2 years of age and have documented a significant disease phenotype that is reminiscent of the late onset, chronic form of human Tay-Sachs disease. Onset occurs at 11-12 months of age and progresses slowly, in parallel with increasing storage of GM2 ganglioside. The disease is characterized by hind limb spasticity, weight loss, tremors, abnormal posture with lordosis, possible visual impairment, and, late in the disease, muscle weakness, clasping of the limbs, and myoclonic twitches of the head. Immunodetection of GM2 ganglioside showed that storage varies widely in different regions, but is most intense in pyriform cortex, hippocampus (CA3 field, subiculum), amygdala, hypothalamus (paraventricular supraoptic, ventromedial and arcuate nuclei, and mammilary body), and the somatosensory cortex (layer V) in 1- to 2-year-old mutant mice. We suggest that the Tay-Sachs mouse model is a phenotypically valid model of disease and may provide for a reliable indicator of the impact of therapeutic strategies, in particular geared to the late onset, chronic form of human Tay-Sachs disease.

Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride).

Science.gov (United States)

Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

2013-01-02

Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 Ω cm2 and 0.83, respectively.

Mice doubly-deficient in lysosomal hexosaminidase A and neuraminidase 4 show epileptic crises and rapid neuronal loss.

Directory of Open Access Journals (Sweden)

Volkan Seyrantepe

2010-09-01

Full Text Available Tay-Sachs disease is a severe lysosomal disorder caused by mutations in the HexA gene coding for the α-subunit of lysosomal β-hexosaminidase A, which converts G(M2 to G(M3 ganglioside. Hexa(-/- mice, depleted of β-hexosaminidase A, remain asymptomatic to 1 year of age, because they catabolise G(M2 ganglioside via a lysosomal sialidase into glycolipid G(A2, which is further processed by β-hexosaminidase B to lactosyl-ceramide, thereby bypassing the β-hexosaminidase A defect. Since this bypass is not effective in humans, infantile Tay-Sachs disease is fatal in the first years of life. Previously, we identified a novel ganglioside metabolizing sialidase, Neu4, abundantly expressed in mouse brain neurons. Now we demonstrate that mice with targeted disruption of both Neu4 and Hexa genes (Neu4(-/-;Hexa(-/- show epileptic seizures with 40% penetrance correlating with polyspike discharges on the cortical electrodes of the electroencephalogram. Single knockout Hexa(-/- or Neu4(-/- siblings do not show such symptoms. Further, double-knockout but not single-knockout mice have multiple degenerating neurons in the cortex and hippocampus and multiple layers of cortical neurons accumulating G(M2 ganglioside. Together, our data suggest that the Neu4 block exacerbates the disease in Hexa(-/- mice, indicating that Neu4 is a modifier gene in the mouse model of Tay-Sachs disease, reducing the disease severity through the metabolic bypass. However, while disease severity in the double mutant is increased, it is not profound suggesting that Neu4 is not the only sialidase contributing to the metabolic bypass in Hexa(-/- mice.

Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30 1995

Energy Technology Data Exchange (ETDEWEB)

Casteel, J. [Bartlesville Project Office, OK (United States)

1996-07-01

The aim of this research project was to investigate mechanisms governing adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy have been determined. A multi-pronged approach consisting of micro & nano spectroscopy, electrokinetics, surface tension and wettability is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the three years contract period, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride were the surfactants studied. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes in interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amounts of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactants in mixed aggregate leads to shielding of the charge of ionic surfactants which in turn promotes aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution on adsorption as well as correlations between monomer concentration in mixtures and adsorption were revealed.

Tay-Sachs Carrier Screening by Enzyme and Molecular Analyses in the New York City Minority Population.

Science.gov (United States)

Mehta, Nikita; Lazarin, Gabriel A; Spiegel, Erica; Berentsen, Kathleen; Brennan, Kelly; Giordano, Jessica; Haque, Imran S; Wapner, Ronald

2016-09-01

Carrier screening for Tay-Sachs disease is performed by sequence analysis of the HEXA gene and/or hexosaminidase A enzymatic activity testing. Enzymatic analysis (EA) has been suggested as the optimal carrier screening method, especially in non-Ashkenazi Jewish (non-AJ) individuals, but its utilization and efficacy have not been fully evaluated in the general population. This study assesses the reliability of EA in comparison with HEXA sequence analysis in non-AJ populations. Five hundred eight Hispanic and African American patients (516 samples) had EA of their leukocytes performed and 12 of these patients who tested positive by EA ("carriers") had subsequent HEXA gene sequencing performed. Of the 508 patients, 25 (4.9%) were EA positive and 40 (7.9%) were inconclusive. Of the 12 patients who were sequenced, 11 did not carry a pathogenic variant and one carried a likely deleterious mutation (NM_000520.4(HEXA):c.1510C>T). High inconclusive rates and poor correlation between positive/inconclusive enzyme results and identification of pathogenic mutations suggest that ethnic-specific recalibration of reference ranges for EA may be necessary. Alternatively, HEXA gene sequencing could be performed.

Intranasal delivery of Huperzine A to the brain using lactoferrin-conjugated N-trimethylated chitosan surface-modified PLGA nanoparticles for treatment of Alzheimer’s disease

Directory of Open Access Journals (Sweden)

Meng QQ

2018-02-01

Full Text Available Qingqing Meng,1,* Aiping Wang,1,2,* Hongchen Hua,1 Ying Jiang,1 Yiyun Wang,1 Hongjie Mu,1 Zimei Wu,1 Kaoxiang Sun1 1School of Pharmacy, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, People’s Republic of China; 2State Key Laboratory of Long-Acting and Targeting Drug Delivery System, Shandong Luye Pharmaceutical Co., Ltd, Yantai, People’s Republic of China *These authors contributed equally to this work Background: Safe and effective delivery of therapeutic drugs to the brain is important for successful therapy of Alzheimer’s disease (AD.Purpose: To develop Huperzine A (HupA-loaded, mucoadhesive and targeted polylactide-co-glycoside (PLGA nanoparticles (NPs with surface modification by lactoferrin (Lf-conjugated N-trimethylated chitosan (TMC (HupA Lf-TMC NPs for efficient intranasal delivery of HupA to the brain for AD treatment.Methods: HupA Lf-TMC NPs were prepared using the emulsion–solvent evaporation method and optimized using the Box–Behnken design. The particle size, zeta potential, drug entrapment efficiency, adhesion and in vitro release behavior were investigated. The cellular uptake was investigated by fluorescence microscopy and flow cytometry. MTT assay was used to evaluate the cytotoxicity of the NPs. In vivo imaging system was used to investigate brain targeting effect of NPs after intranasal administration. The biodistribution of Hup-A NPs after intranasal administration was determined by liquid chromatography–tandem mass spectrometry.Results: Optimized HupA Lf-TMC NPs had a particle size of 153.2±13.7 nm, polydispersity index of 0.229±0.078, zeta potential of +35.6±5.2 mV, drug entrapment efficiency of 73.8%±5.7%, and sustained release in vitro over a 48 h period. Adsorption of mucin onto Lf-TMC NPs was 86.9%±1.8%, which was significantly higher than that onto PLGA NPs (32.1%±2.5%. HupA Lf-TMC NPs showed lower toxicity

Photoabsorption and time-of-flight mass spectroscopy for gas-phase trimethyl phosphate following valence shell excitation

International Nuclear Information System (INIS)

Homem, M.G.P.; Rosa, L.F.S.; Farenzena, L.S.; Hasse, A.; Iza, P.; Cavasso Filho, R.L.; Lee, M.T.; Iga, I.

2012-01-01

Full text: In this work we report an experimental study on photoabsorption of trimethyl phosphate (TMP) molecules in the vacuum-ultraviolet energy range. More specifically, absolute photoabsorption cross sections and photoionization yields are measured and reported in the (11.11-21.45) eV energy range. The photoionization and neutral-decay cross sections in absolute scale are also derived and reported. Details of our experimental setup and procedure for cross-section determination can be found in our previous work [1]. Essentially, the measurements were performed using a double-ion-chamber technique [2]. The experimental cross-section results are analyzed in comparison with PES measurements. Oscillator strengths sum rules over the extrapolated experimental data gives a value of 71.6 au for the static dipole polarizability of TMP, which is in excellent agreement with the value of 72.3 au reported in literature. In addition, the ionic dissociation in the same energy range has been studied by time-of-flight mass spectrometry [3]. The detected product cations are C 3 H 9 O 4 P + , C 3 H 8 O 4 P + , CH 3 O 4 P + , C 2 H 6 O 3 P + , PO 4 + , CH 5 O 2 P + , PO 3 + , and CH 3 + . The observed ionic branching ratios are converted in absolute scale by using the measured photoionization cross sections. The presence of two ionic metastable states corresponding to the C 3 H 9 O 4 P + and CH 3 O 4 P + fragments are reported and their metastable ion mean lives are estimated in (152±5) ns and (248±30) ns. The results and discussion will be presented during the workshop. [1] M. G. P. Homem, P. Iza, L. S. Farenzena, R. L. Cavasso-Filho, M. T. Lee and I. Iga, J. Phys. B: At. Mol. Opt. Phys. 42, 235204 (2009). [2] J. A. R. Samson and Lifeng Yin, J. Opt. Soc. Am B 6, 2326 (1989). [3] F. Burmeister, L. H. Coutinho, R. R. T. Marinho, M. G. P. Homem, M. A. A. Morais, A. Mocellin, O. Bjorneholm, S. L. Sorensen, P. T. Fonseca, A. Lindgren and A. Naves de Brito, J. Electron Spectrosc

(2aR*,5S*,6aS*,8aS*,E-Ethyl 5-hydroxy-7,7,8a-trimethyl-8-oxo-2,2a,6,6a,7,8,8a,8b-octahydro-1H-pentaleno[1,6-bc]oxepine-4-carboxylate

Directory of Open Access Journals (Sweden)

Goverdhan Mehta

2012-12-01

Full Text Available The title compound, C17H24O5, featuring a 2-carbethoxy-3-oxepanone unit in its intramolecularly O—H...O hydrogen-bonded enol form, was obtained via [(CF3CO22Rh]2-catalysed intramolecular O—H bond insertion in the α-diazo-ω-hydroxy-β-ketoester, ethyl 4-[(1S,3aS,6R,6aS-6-hydroxy-2,2,3a-trimethyl-3-oxo-octahydropentalen-1-yl]-2-diazo-3-oxobutanoate. The seven-membered oxacyclic ring, thus constructed on a cis-fused diquinane platform, was found to adopt a distorted boat–sofa conformation.

Comparative Analyses of H3K4 and H3K27 Trimethylations Between the Mouse Cerebrum and Testis

KAUST Repository

Cui, Peng

2012-06-08

The global features of H3K4 and H3K27 trimethylations (H3K4me3 and H3K27me3) have been well studied in recent years, but most of these studies were performed in mammalian cell lines. In this work, we generated the genome-wide maps of H3K4me3 and H3K27me3 of mouse cerebrum and testis using ChIP-seq and their high-coverage transcriptomes using ribominus RNA-seq with SOLiD technology. We examined the global patterns of H3K4me3 and H3K27me3 in both tissues and found that modifications are closely-associated with tissue-specific expression, function and development. Moreover, we revealed that H3K4me3 and H3K27me3 rarely occur in silent genes, which contradicts the findings in previous studies. Finally, we observed that bivalent domains, with both H3K4me3 and H3K27me3, existed ubiquitously in both tissues and demonstrated an invariable preference for the regulation of developmentally-related genes. However, the bivalent domains tend towards a “winner-takes-all” approach to regulate the expression of associated genes. We also verified the above results in mouse ES cells. As expected, the results in ES cells are consistent with those in cerebrum and testis. In conclusion, we present two very important findings. One is that H3K4me3 and H3K27me3 rarely occur in silent genes. The other is that bivalent domains may adopt a “winner-takes-all” principle to regulate gene expression.

Effect of cetyl trimethyl ammonium bromide concentration on structure, morphology and carbon dioxide adsorption capacity of calcium hydroxide based sorbents

International Nuclear Information System (INIS)

Hlaing, Nwe Ni; Vignesh, K.; Sreekantan, Srimala; Pung, Swee-Yong; Hinode, Hirofumi; Kurniawan, Winarto; Othman, Radzali; Thant, Aye Aye; Mohamed, Abdul Rahman; Salim, Chris

2016-01-01

Graphical abstract: Carbonation conversions of (a) CC, (b) CH-2, (c) CH-4, (d) CH-6, (e) CH-8 precursor adsorbents for 10 cycles. - Highlights: • Ca(OH)_2 precursor was synthesized using precipitation method. • The effect of CTAB concentration on the synthesis of Ca(OH)_2 was studied. • The sorbent synthesized using 0.8 M of CTAB showed good CO_2 adsorption capacity. • The cyclic stability of Ca(OH)_2 was increased with increase of CTAB concentration. - Abstract: Calcium hydroxide (Ca(OH)_2) has been proposed as an important material for industrial, architectural, and environmental applications. In this study, calcium acetate was used as a precursor and cetyl trimethyl ammonium bromide (CTAB) was used as a surfactant to synthesize Ca(OH)_2 based adsorbents for carbon dioxide (CO_2) capture. The effect of CTAB concentration (0.2–0.8 M) on the structure, morphology and CO_2 adsorption performance of Ca(OH)_2 was studied in detail. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), BET surfaced area and thermogravimetry-differential thermal analysis (TG–DTA) techniques. The phase purity, crystallite size, Brunauer–Emmett–Teller (BET) surface area and CO_2 adsorption performance of Ca(OH)_2 precursor adsorbents were significantly increased when the concentration of CTAB was increased. XRD results showed that pure Ca(OH)_2 phase was obtained at the CTAB concentration of 0.8 M. TGA results exhibited that 0.8 M of CTAB-assisted Ca(OH)_2 precursor adsorbent possessed a residual carbonation conversion of ∼56% after 10 cycles.

Construction of a hybrid β-hexosaminidase subunit capable of forming stable homodimers that hydrolyze GM2 ganglioside in vivo

Directory of Open Access Journals (Sweden)

Michael B Tropak

2016-01-01

Full Text Available Tay-Sachs or Sandhoff disease result from mutations in either the evolutionarily related HEXA or HEXB genes encoding respectively, the α- or β-subunits of β-hexosaminidase A (HexA. Of the three Hex isozymes, only HexA can interact with its cofactor, the GM2 activator protein (GM2AP, and hydrolyze GM2 ganglioside. A major impediment to establishing gene or enzyme replacement therapy based on HexA is the need to synthesize both subunits. Thus, we combined the critical features of both α- and β-subunits into a single hybrid µ-subunit that contains the α-subunit active site, the stable β-subunit interface and unique areas in each subunit needed to interact with GM2AP. To facilitate intracellular analysis and the purification of the µ-homodimer (HexM, CRISPR-based genome editing was used to disrupt the HEXA and HEXB genes in a Human Embryonic Kidney 293 cell line stably expressing the µ-subunit. In association with GM2AP, HexM was shown to hydrolyze a fluorescent GM2 ganglioside derivative both in cellulo and in vitro. Gene transfer studies in both Tay-Sachs and Sandhoff mouse models demonstrated that HexM expression reduced brain GM2 ganglioside levels.

Construction of a hybrid β-hexosaminidase subunit capable of forming stable homodimers that hydrolyze GM2 ganglioside in vivo

Science.gov (United States)

Tropak, Michael B; Yonekawa, Sayuri; Karumuthil-Melethil, Subha; Thompson, Patrick; Wakarchuk, Warren; Gray, Steven J; Walia, Jagdeep S; Mark, Brian L; Mahuran, Don

2016-01-01

Tay-Sachs or Sandhoff disease result from mutations in either the evolutionarily related HEXA or HEXB genes encoding respectively, the α- or β-subunits of β-hexosaminidase A (HexA). Of the three Hex isozymes, only HexA can interact with its cofactor, the GM2 activator protein (GM2AP), and hydrolyze GM2 ganglioside. A major impediment to establishing gene or enzyme replacement therapy based on HexA is the need to synthesize both subunits. Thus, we combined the critical features of both α- and β-subunits into a single hybrid µ-subunit that contains the α-subunit active site, the stable β-subunit interface and unique areas in each subunit needed to interact with GM2AP. To facilitate intracellular analysis and the purification of the µ-homodimer (HexM), CRISPR-based genome editing was used to disrupt the HEXA and HEXB genes in a Human Embryonic Kidney 293 cell line stably expressing the µ-subunit. In association with GM2AP, HexM was shown to hydrolyze a fluorescent GM2 ganglioside derivative both in cellulo and in vitro. Gene transfer studies in both Tay-Sachs and Sandhoff mouse models demonstrated that HexM expression reduced brain GM2 ganglioside levels. PMID:26966698

Incorporation of μ3-CO3 into an MnIII/MnIV Mn12 cluster: {[(cyclam)MnIV(μ-O)2MnIII(H2O)(μ-OH)]6(μ3-CO3)2}Cl8·24H2O

Science.gov (United States)

Levaton, Ben B.; Olmstead, Marilyn M.

2010-01-01

The centrosymmetric title cluster, hexa­aquadi-μ3-carbonato-hexa­cyclamhexa-μ2-hydroxido-dodeca-μ2-oxido-hexa­mang­an­ese(IV)hexa­manganese(III) octa­chloride tetra­cosa­hydrate, [Mn12(CO3)2O12(OH)6(C10H24N4)6(H2O)6]Cl8·24H2O, has two μ3-CO3 groups that not only bridge octahedrally coordinated MnIII ions but also act as acceptors to two different kinds of hydrogen bonds. The carbonate anion is planar within experimental error and has an average C—O distance of 1.294 (4) Å. The crystal packing is stabilized by O—H⋯Cl, O—H⋯O, N—H⋯Cl and N—H⋯O hydrogen bonds. Two of the four independent chloride ions are disordered over five positions, and eight of the 12 independent water mol­ecules are disordered over 21 positions. PMID:21587382

Effect of cetyl trimethyl ammonium bromide concentration on structure, morphology and carbon dioxide adsorption capacity of calcium hydroxide based sorbents

Energy Technology Data Exchange (ETDEWEB)

Hlaing, Nwe Ni, E-mail: nwenihlaing76@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Vignesh, K., E-mail: vignesh134@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Anano Sphere Sdn Bhd, Lorong Industri 11, Kawasan Industri Bukit Panchor, 14300 Nibong Tebal, Penang (Malaysia); Sreekantan, Srimala, E-mail: srimala@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Pung, Swee-Yong [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hinode, Hirofumi; Kurniawan, Winarto [Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Othman, Radzali [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Malacca (Malaysia); Thant, Aye Aye [Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Mohamed, Abdul Rahman [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Salim, Chris [Department of Environmental Engineering, Surya University, Tangerang 15810, Banten (Indonesia)

2016-02-15

Graphical abstract: Carbonation conversions of (a) CC, (b) CH-2, (c) CH-4, (d) CH-6, (e) CH-8 precursor adsorbents for 10 cycles. - Highlights: • Ca(OH){sub 2} precursor was synthesized using precipitation method. • The effect of CTAB concentration on the synthesis of Ca(OH){sub 2} was studied. • The sorbent synthesized using 0.8 M of CTAB showed good CO{sub 2} adsorption capacity. • The cyclic stability of Ca(OH){sub 2} was increased with increase of CTAB concentration. - Abstract: Calcium hydroxide (Ca(OH){sub 2}) has been proposed as an important material for industrial, architectural, and environmental applications. In this study, calcium acetate was used as a precursor and cetyl trimethyl ammonium bromide (CTAB) was used as a surfactant to synthesize Ca(OH){sub 2} based adsorbents for carbon dioxide (CO{sub 2}) capture. The effect of CTAB concentration (0.2–0.8 M) on the structure, morphology and CO{sub 2} adsorption performance of Ca(OH){sub 2} was studied in detail. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), BET surfaced area and thermogravimetry-differential thermal analysis (TG–DTA) techniques. The phase purity, crystallite size, Brunauer–Emmett–Teller (BET) surface area and CO{sub 2} adsorption performance of Ca(OH){sub 2} precursor adsorbents were significantly increased when the concentration of CTAB was increased. XRD results showed that pure Ca(OH){sub 2} phase was obtained at the CTAB concentration of 0.8 M. TGA results exhibited that 0.8 M of CTAB-assisted Ca(OH){sub 2} precursor adsorbent possessed a residual carbonation conversion of ∼56% after 10 cycles.

Development of new additive for drilling fluid from the partial hydrophobization N,N,N-trimethyl chitosan (TMC); Desenvolvimento de novos aditivos para fluidos de perfuracao a partir da hidrofobizacao parcial da N,N,N trimetilquitosana (TMQ)

Energy Technology Data Exchange (ETDEWEB)

Carmo, Thacyla C. do; Lopes, Grazielle; Silva, Joaquim F.M. da; Nascimento, Regina S.V., E-mail: cycyla@hotmail.co [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Polo de Xistoquimica

2009-07-01

N,N,N-trimethyl chitosan (TMC) hydrophobically modified can act as an excellent additive for drilling fluids water based, working as inhibitor of reactive shales and rheological modifiers. The cationic chitosan was obtained by reaction of chitosan with CH{sub 3}I in N-methyl-2-pyrrolidone to obtain the TMC and chitosan was also hydrophobically modified with palmitoil chloride to get Quit P. Through another route, Quit P was modified to obtain the cationic TMCP. The derivatives were characterized by FT-IR and {sup 1}HNMR spectrophotometry allowing the calculation of the degree of quaternization of the TMC. The rheology tests showed that the system with TMCP presented pseudo plastic behavior, while the system with TMC behaved as a Newtonian fluid. The results indicated that TMCP can act as rheology modifier for water-based drilling fluids. (author)

Photoabsorption and time-of-flight mass spectroscopy for gas-phase trimethyl phosphate following valence shell excitation

Energy Technology Data Exchange (ETDEWEB)

Homem, M.G.P.; Rosa, L.F.S.; Farenzena, L.S.; Hasse, A. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Iza, P. [Escuela Superior Politecnica del Litoral, Guayaquil Guaya (Ecuador); Cavasso Filho, R.L. [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil); Lee, M.T.; Iga, I. [Universidade Federal de Sao Carlos (UFSCar), Sao Carlos, SP (Brazil)

2012-07-01

Full text: In this work we report an experimental study on photoabsorption of trimethyl phosphate (TMP) molecules in the vacuum-ultraviolet energy range. More specifically, absolute photoabsorption cross sections and photoionization yields are measured and reported in the (11.11-21.45) eV energy range. The photoionization and neutral-decay cross sections in absolute scale are also derived and reported. Details of our experimental setup and procedure for cross-section determination can be found in our previous work [1]. Essentially, the measurements were performed using a double-ion-chamber technique [2]. The experimental cross-section results are analyzed in comparison with PES measurements. Oscillator strengths sum rules over the extrapolated experimental data gives a value of 71.6 au for the static dipole polarizability of TMP, which is in excellent agreement with the value of 72.3 au reported in literature. In addition, the ionic dissociation in the same energy range has been studied by time-of-flight mass spectrometry [3]. The detected product cations are C{sub 3}H{sub 9}O{sub 4}P{sup +}, C{sub 3}H{sub 8}O{sub 4}P{sup +}, CH{sub 3}O{sub 4}P{sup +}, C{sub 2}H{sub 6}O{sub 3}P{sup +}, PO{sub 4}{sup +}, CH{sub 5}O{sub 2}P{sup +}, PO{sub 3}{sup +}, and CH{sub 3}{sup +}. The observed ionic branching ratios are converted in absolute scale by using the measured photoionization cross sections. The presence of two ionic metastable states corresponding to the C{sub 3}H{sub 9}O{sub 4}P{sup +} and CH{sub 3}O{sub 4}P{sup +} fragments are reported and their metastable ion mean lives are estimated in (152{+-}5) ns and (248{+-}30) ns. The results and discussion will be presented during the workshop. [1] M. G. P. Homem, P. Iza, L. S. Farenzena, R. L. Cavasso-Filho, M. T. Lee and I. Iga, J. Phys. B: At. Mol. Opt. Phys. 42, 235204 (2009). [2] J. A. R. Samson and Lifeng Yin, J. Opt. Soc. Am B 6, 2326 (1989). [3] F. Burmeister, L. H. Coutinho, R. R. T. Marinho, M. G. P. Homem, M. A

The impact of kappa number composition on eucalyptus kraft pulp bleachability

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M. M. Costa

2007-03-01

Full Text Available Consumption of chemicals during ECF bleaching of kraft pulp correlates reasonably well with kappa number, which measures with KMnO4 the total amount of oxidizable material in the pulp. However, the method does not distinguish between the oxidizable material in residual lignin and other structures susceptible to oxidation, such as hexenuronic acids (HexAs, extractives and carbonyl groups in the pulp. In this study an attempt is made to separate the main contributors to the kappa number in oxygen - delignified eucalyptus Kraft pulps and evaluate how these fractions behave during ECF bleaching using chlorine dioxide as the sole oxidant (DEDD sequence. Residual lignin and HexAs proved to be the main fractions contributing to the kappa number and chlorine dioxide consumption in ECF bleaching. Pulp bleachability with chlorine dioxide increases with increasing HexAs content of the pulp but chlorine dioxide per se does not react with HexAs. Reduction of pulp with sodium borohydride under conditions for removing carbonyl groups has no impact on bleachability. No correlation was found between the pulp of the extractive content and pulp bleachability. The removal of HexAs prior to ECF bleaching significantly decreases the formation of chlorinated organics in the pulp (OX and filtrates (AOX as well as of oxalic acids in the filtrates.

Identification of ftalates used as additives in the geo membrane of a la Florida reservoir through gas chromatography-mass spectrometry

International Nuclear Information System (INIS)

Blanco, M.; Rico, G.; Pargada, L.; Aguiar, E.; Castillo, F.

2009-01-01

This article studies the behaviour of the plastified poly (vinyl chloride) (PVC-P) applied as synthetic geo membrane for the waterproofing of the La Florida reservoir. We show the results of the initial examen of its properties and its most significant characteristics eighteen years after being applied. Furthermore we isolate and identify the quantitative and qualitative aspects of the plasticizers used in its formula through infrared spectroscopy, gas chromatography and mass spectrometry technic. We have identified as the said plasticizers di-n-octyl phthalate, di-n-decyl phthalate and n-decyl n-octyl phthalate, and we calculate the joint average molecular weight using Wilsons equation. The results found that the geo membranes we have studied has shown an excellent behaviour along through time. (Author) 53 refs

Cell lineage specific distribution of H3K27 trimethylation accumulation in an in vitro model for human implantation.

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Gijs Teklenburg

Full Text Available Female mammals inactivate one of their two X-chromosomes to compensate for the difference in gene-dosage with males that have just one X-chromosome. X-chromosome inactivation is initiated by the expression of the non-coding RNA Xist, which coats the X-chromosome in cis and triggers gene silencing. In early mouse development the paternal X-chromosome is initially inactivated in all cells of cleavage stage embryos (imprinted X-inactivation followed by reactivation of the inactivated paternal X-chromosome exclusively in the epiblast precursors of blastocysts, resulting temporarily in the presence of two active X-chromosomes in this specific lineage. Shortly thereafter, epiblast cells randomly inactivate either the maternal or the paternal X-chromosome. XCI is accompanied by the accumulation of histone 3 lysine 27 trimethylation (H3K27me3 marks on the condensed X-chromosome. It is still poorly understood how XCI is regulated during early human development. Here we have investigated lineage development and the distribution of H3K27me3 foci in human embryos derived from an in-vitro model for human implantation. In this system, embryos are co-cultured on decidualized endometrial stromal cells up to day 8, which allows the culture period to be extended for an additional two days. We demonstrate that after the co-culture period, the inner cell masses have relatively high cell numbers and that the GATA4-positive hypoblast lineage and OCT4-positive epiblast cell lineage in these embryos have segregated. H3K27me3 foci were observed in ∼25% of the trophectoderm cells and in ∼7.5% of the hypoblast cells, but not in epiblast cells. In contrast with day 8 embryos derived from the co-cultures, foci of H3K27me3 were not observed in embryos at day 5 of development derived from regular IVF-cultures. These findings indicate that the dynamics of H3K27me3 accumulation on the X-chromosome in human development is regulated in a lineage specific fashion.

Xylanase XYN IV from Trichoderma reesei showing exo- and endo-xylanase activity

Science.gov (United States)

A novel xylanase from Trichoderma reesei Rut C30, named XYN IV, was purified from the cellulolytic system of the fungus. The enzyme was discovered on its ability to attack aldotetraohexenuronic acid (HexA-2Xyl-4Xyl-4Xyl, HexA3Xyl3), releasing the reducing-end xylose residue. XYN IV exhibited catalyt...

Xylanase-Aided Chlorine Dioxide Bleaching of Bagasse Pulp to Reduce AOX Formation

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Yi Dai

2016-02-01

Full Text Available Xylanase pretreatment was used to improve the chlorine dioxide bleaching of bagasse pulp. The pulp was pretreated with xylanase, which was followed by a chlorine dioxide bleaching stage. The HexA content of the pulp and the AOX content of the bleaching effluent were measured using UV-Vis and GC-MS methods, respectively. The results showed that a good correlation occurred between HexA and kappa number. HexA content of the pulp decreased significantly after the xylanase pretreatment. The AOX content of the bleaching effluent decreased as HexA was removed from the pulp. It was found that AOX could be reduced by up to 29.8%, comparing XD0 with a D0 stage. Fourier transform infrared spectroscopy (FTIR was employed to determine the breakage of chemical bonds in the pulp. It revealed that some lignin and hemicellulose were removed after xylanase treatment. The GC-MS results showed that some toxic chloride such as 2,4,6-trichlorophenol could be completely removed after xylanase pretreatment.

Differential regulation of the phosphorylation of Trimethyl-lysine27 histone H3 at serine 28 in distinct populations of striatal projection neurons.

Science.gov (United States)

Bonito-Oliva, Alessandra; Södersten, Erik; Spigolon, Giada; Hu, Xiaochen; Hellysaz, Arash; Falconi, Anastasia; Gomes, Ana-Luisa; Broberger, Christian; Hansen, Klaus; Fisone, Gilberto

2016-08-01

Phosphorylation of histone H3 (H3) on serine 28 (S28) at genomic regions marked by trimethylation of lysine 27 (H3K27me3) often correlates with increased expression of genes normally repressed by Polycomb group proteins (PcG). We show that amphetamine, an addictive psychostimulant, and haloperidol, a typical antipsychotic drug, increase the phosphorylation of H3 at S28 and that this effect occurs in the context of H3K27me3. The increases in H3K27me3S28p occur in distinct populations of projection neurons located in the striatum, the major component of the basal ganglia. Genetic inactivation of the protein phosphatase-1 inhibitor, dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32), reduces the phosphorylation of H3K27me3S28 produced by amphetamine and haloperidol. In contrast, knockout of the mitogen- and stress activated kinase 1 (MSK1), which is implicated in the phosphorylation of histone H3, decreases the effect of amphetamine, but not that of haloperidol. Chromatin immunoprecipitation analysis shows that amphetamine and haloperidol increase the phosphorylation of H3K27me3S28 at the promoter regions of Atf3, Npas4 and Lipg, three genes repressed by PcG. These results identify H3K27me3S28p as a potential mediator of the effects exerted by amphetamine and haloperidol, and suggest that these drugs may act by re-activating PcG repressed target genes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Di-μ-cyanido-tetra-cyanido(5,5,7,12,12,14-hexa-methyl-1,4,8,11-tetra-aza-cyclo-tetra-decane)[N-(quinolin-8-yl)quinoline-2-carboxamidato]diiron(III)nickel(II) 2.07-hydrate.

Science.gov (United States)

Yang, Yuqi; Zhou, Hongbo; Shen, Xiaoping

2013-05-01

The asymmetric unit of the title complex, [Fe2Ni(C19H12N3O)2(CN)6(C16H36N4)]·2.07H2O, contains one [Fe(qcq)(CN)3](-) anion, half a [Ni(teta)](2+) cation and two partially occupied inter-stitial water mol-ecules [qcq(-) is the N-(quinolin-8-yl)quinoline-2-carboxamidate anion and teta is 5,5,7,12,12,14-hexa-methyl-1,4,8,11-tetra-aza-cyclo-tetra-deca-ne]. In the complex mol-ecule, two [Fe(qcq)(CN)3](-) anions additionally coordinate the central [Ni(teta)](2+) cation through cyanide groups in a trans mode, resulting in a trinuclear structure with the Ni(2+) cation lying on an inversion centre. The two inter-stitial water mol-ecules are partially occupied, with occupancy factors of 0.528 (10) and 0.506 (9). O-H⋯O and O-H⋯N hydrogen bonding involving the two lattice water molecules and the carbonyl function and a teta N atom in an adjacent cluster leads to the formation of layers extending parallel to (010).

Syntheses, Protonation Constants and Antimicrobial Activity of 2 ...

African Journals Online (AJOL)

carboxaldehyde and N-alkylimidazole-2-methanol derivatives [alkyl = benzyl, methyl, ethyl, propyl, butyl, heptyl, octyl and decyl] have been synthesized and the protonation constants determined. The antimicrobial properties of the compounds were tested ...

Removal of Hexavalent Chromium from Aqueous Solutions Using Magnetic Nanoparticles Coated with Alumina and Modified by Cetyl Trimethyl Ammonium Bromide

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Mohammad Malakootian

2015-12-01

Full Text Available Introduction: The development of an effective method regarding chromium removal from the environment is of great importance. Therefore, the present study aimed to examiner magnetic nanoparticles coated with alumina modified by Cetyl Trimethyl Ammonium Bromide (CTAB in the removal of Cr6+ through magnetic solid phase extraction method. Materials & Methods: At first, iron oxide nanoparticles were synthesized, coated with alumina, modified with CTAB and characterized with suitable instruments. The factors affecting the process of chromium removal were investigated, including the concentration of CTAB, the pH, the amount of nanoparticles, the sample volume, a proper eluent, the adsorption and desorption time, and the effect of interfering ions. Moreover, the chromium concentration was determined by flame atomic absorption spectrometric (FAAS technique. The adsorption isotherm, adsorption capacity, and recoverability of the adsorbent were further examined. Results: The modified magnetic nanoparticles were demonstrated to be homogeneous, spherical, with a size lower than 20 nanometer having a magnetic property. The optimal conditions for chromium removal entailed 7*10-6 mol/L concentration of CTAB, pH range of 6-8, 0.1 g of the nanoparticles, 10 mL volume of the chromium sample (5 &mug mL-1, nitric acid 2 M as a suitable eluent, 15 minutes of adsorption and desorption, and no interference of interfering ions in the process of chromium separation. The process efficiency under optimal conditions was determined to be over 95%, which this process followed the Langmuir adsorption isotherm. The adsorption capacity proved to be 23.8 mg/g. Reusing after four times of adsorbent recovering was effective in the chromium removal (80%. The method accuracy for five measurement times was 4.155% and the method’s LOD was 0.081 mg/L. Conclusion: The method enjoys the benefits of convenient preparation of the adsorbent, high selectivity, high accuracy, short process

Probing photochromic properties by correlation of UV-visible and infra-red absorption spectroscopy: a case study with cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene.

Science.gov (United States)

Spangenberg, Arnaud; Piedras Perez, Jose Alejandro; Patra, Abhijit; Piard, Jonathan; Brosseau, Arnaud; Métivier, Rémi; Nakatani, Keitaro

2010-02-01

Quantification of the relative composition of the isomers in a photochromic system at any irradiation time interval is a critical issue in determining absolute quantum yields. For this purpose, we have developed a simple and convenient protocol involving combination of UV-visible and infra-red absorption spectroscopy. Photochromic cyclization reaction of cis-l,2-dicyano-l,2-bis(2,4,5-trimethyl-3-thieny1)ethene (CMTE) is analyzed to demonstrate the efficiency of the proposed methodology. This approach is based on the fact that the two isomers show distinctive infra-red bands. Detailed investigations of the UV-visible and infra-red spectra of the mixture obtained at different irradiation times in CCl(4) supported by quantum chemical computations lead to the unambiguous estimation of molar absorption coefficients of the closed isomer (epsilon(CF) = 4650 L mol(-1) cm(-1) at 512 nm). It facilitates the first determination of absolute quantum yields of this reversible photochromic reaction in CCl(4) by fitting the UV-visible spectral data (Phi(OF-->CF) = 0.41 +/- 0.05 and Phi(CF-->OF) = 0.12 +/- 0.02 at 405 nm and 546 nm, respectively).

Safety and immune response to a challenge dose of hepatitis B vaccine in healthy children primed 10years earlier with hexavalent vaccines in a 3, 5, 11-month schedule: An open-label, controlled, multicentre trial in Italy.

Science.gov (United States)

Zanetti, Alessandro; Desole, Maria Giuseppina; Romanò, Luisa; d'Alessandro, Antonio; Conversano, Michele; Ferrera, Giuseppe; Panico, Maria Grazia; Tomasi, Alberto; Zoppi, Giorgio; Zuliani, Massimo; Thomas, Stéphane; Soubeyrand, Benoît; Eymin, Cécile; Lockhart, Stephen

2017-07-13

The strategy of vaccinating infants to prevent hepatitis B virus infection in adolescence or adulthood requires durable immunity. This study investigated responses to a challenge dose of monovalent hepatitis B vaccine in children primed with three doses of either Hexavac® or Infanrix hexa® 10years earlier during infancy. This open-label, controlled, multicentre study conducted in Italy, enrolled 751 healthy pre-adolescents (aged 11-13years) who were given either Hexavac (n=409) or Infanrix hexa (n=342) at 3, 5 and 11months of life. All participants received a challenge dose of a monovalent hepatitis B vaccine (HBVaxPro® 5µg). The concentrations of antibodies to hepatitis B surface antigen (anti-HBs) were measured before and 1month after the challenge dose. The analysis was descriptive and no formal hypothesis was tested. One month post-challenge, 331 participants in the Hexavac cohort [83.6%, 95% CI: 79.6; 87.1] and 324 in the Infanrix hexa cohort [96.4%, 95% CI: 93.8; 98.1] had anti-HBs concentrations ≥10mIU/mL. Before the challenge dose, an anti-HBs concentration of ≥10mIU/mL was found in 94 children in the Hexavac cohort [23.9%, 95% CI: 19.7; 28.4] and in 232 children in the Infanrix hexa cohort [69%, 95% CI: 63.8; 74.0]. Among children with a pre-challenge anti-HBs concentration of children (>80%) at least 10years after a two-dose primary and booster vaccination schedule with a hexavalent vaccine (Hexavac or Infanrix hexa). EudraCT Number: 2013-001602-28; clinicaltrials.gov: NCT02012998. Copyright © 2017 Elsevier Ltd. All rights reserved.

Kraft pulping and ECF bleaching of Eucalyptus globulus pretreated by the white-rot fungus Ceriporiopsis subvermispora - doi: 10.4025/actascitechnol.v34i3.12410

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Claudio Salazar

2012-05-01

Full Text Available Eucalyptus globulus wood chips were decayed by the lignin-degrading fungus Ceriporiopsis subvermispora as a pretreatment step before kraft pulping. Weight and component losses of wood after the biotreatment were the following: weight (5%, glucans (1.5%, xylans (4.3%, lignin (5.7% and extractives (57.5%. The residual amount of lignin (expressed by the kappa number in pulps from biotreated wood chips was lower than that of pulps from the undecayed control. Depending on the delignification degree, kraft biopulps presented similar or up to 4% increase in pulp yield and 20% less hexenuronic acids (HexA than control pulps. The extended delignification with O2 decreases approximately 50% of the kappa number of the pulps and increases brightness, but had no effect in HexA reduction. The bleaching steps with chlorine dioxide (D0ED1 sequence decreased the kappa number up to 97%, increased pulp brightness up to 84% ISO and decreased HexA amount up to 91%. The use of C. subvermispora in biopulping of E. globulus generated important benefits during the production of kraft pulps that are reflected in a high pulp yield, low residual lignin content, low HexA amount, high brightness and viscosity of the biopulps as compared with pulps produced from untreated wood chips.

Pheromone-induced priming of a defensive response in Western flower thrips

NARCIS (Netherlands)

de Bruijn, P.J.A.; Egas, M.; Janssen, A.; Sabelis, M.W.

2006-01-01

Abstract The Western flower thrips Frankliniella occidentalis produces conspicuous anal droplets that function as a direct defense against various predators. These droplets also function in pheromonal communication in that they contain a mixture of decyl acetate and dodecyl acetate, which acts as an

A step-by-step approach to study the influence of N-acetylation on the adjuvanticity of N,N,N-trimethyl chitosan (TMC) in an intranasal nanoparticulate influenza virus vaccine.

Science.gov (United States)

Verheul, Rolf J; Hagenaars, Niels; van Es, Thomas; van Gaal, Ethlinn V B; de Jong, Pascal H J L F; Bruijns, Sven; Mastrobattista, Enrico; Slütter, Bram; Que, Ivo; Heldens, Jacco G M; van den Bosch, Han; Glansbeek, Harrie L; Hennink, Wim E; Jiskoot, Wim

2012-03-12

Recently we reported that reacetylation of N,N,N-trimethyl chitosan (TMC) reduced the adjuvant effect of TMC in mice after intranasal (i.n.) administration of whole inactivated influenza virus (WIV) vaccine. The aim of the present study was to elucidate the mechanism of this lack of adjuvanticity. Reacetylated TMC (TMC-RA, degree of acetylation 54%) was compared with TMC (degree of acetylation 17%) at six potentially critical steps in the induction of an immune response after i.n. administration in mice. TMC-RA was degraded in a nasal wash to a slightly larger extent than TMC. The local i.n. distribution and nasal clearance of WIV were similar for both TMC types. Fluorescently labeled WIV was taken up more efficiently by Calu-3 cells when formulated with TMC-RA compared to TMC and both TMCs significantly reduced transport of WIV over a Calu-3 monolayer. Murine bone-marrow derived dendritic cell activation was similar for plain WIV, and WIV formulated with TMC-RA or TMC. The inferior adjuvant effect in mice of TMC-RA over that of TMC might be caused by a slightly lower stability of TMC-RA-WIV in the nasal cavity, rather than by any of the other factors studied in this paper. Copyright © 2011 Elsevier B.V. All rights reserved.

Characterization and obtainment of thin films based on N,N,N-trimethyl chitosan and heparin through the technical layer-by-layer; Caracterizacao e obtencao de filmes finos de N,N,N-trimetil quitosana e heparina atraves da tecnica layer-by-layer

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

Thin films of Heparin (HP) and N,N,N-trimethyl chitosan (TMC) with a high degree of quaternization (DQ) were obtained at pH 7.4 through the layer-by-layer (LbL) technique. Polystyrene (PS) was oxidized with aqueous solution of sodium persulfate and subsequently employed as substrate. The characterization of TMC and the respective determination of DQ were performed through {sup 1}H NMR spectroscopy. The thin films de TMC/HP were characterized by FTIR-ATR and AFM. Both techniques confirmed the adsorption of TMC and HP in surface of the PS. The increasing of the bilayers provides a decrease of the projections and/or roughness, further of minimizing the depressions at the surface of the films. Studies of thin films the base of TMC/HP prepared from the LbL technique has not been reported in the literature. It is expected that the thin films of TMC/HP present anti-adhesive and antimicrobial properties. (author)

Crystal structure of heterodimeric hexaprenyl diphosphate synthase from Micrococcus luteus B-P 26 reveals that the small subunit is directly involved in the product chain length regulation.

Science.gov (United States)

Sasaki, Daisuke; Fujihashi, Masahiro; Okuyama, Naomi; Kobayashi, Yukiko; Noike, Motoyoshi; Koyama, Tanetoshi; Miki, Kunio

2011-02-04

Hexaprenyl diphosphate synthase from Micrococcus luteus B-P 26 (Ml-HexPPs) is a heterooligomeric type trans-prenyltransferase catalyzing consecutive head-to-tail condensations of three molecules of isopentenyl diphosphates (C(5)) on a farnesyl diphosphate (FPP; C(15)) to form an (all-E) hexaprenyl diphosphate (HexPP; C(30)). Ml-HexPPs is known to function as a heterodimer of two different subunits, small and large subunits called HexA and HexB, respectively. Compared with homooligomeric trans-prenyltransferases, the molecular mechanism of heterooligomeric trans-prenyltransferases is not yet clearly understood, particularly with respect to the role of the small subunits lacking the catalytic motifs conserved in most known trans-prenyltransferases. We have determined the crystal structure of Ml-HexPPs both in the substrate-free form and in complex with 7,11-dimethyl-2,6,10-dodecatrien-1-yl diphosphate ammonium salt (3-DesMe-FPP), an analog of FPP. The structure of HexB is composed of mostly antiparallel α-helices joined by connecting loops. Two aspartate-rich motifs (designated the first and second aspartate-rich motifs) and the other characteristic motifs in HexB are located around the diphosphate part of 3-DesMe-FPP. Despite the very low amino acid sequence identity and the distinct polypeptide chain lengths between HexA and HexB, the structure of HexA is quite similar to that of HexB. The aliphatic tail of 3-DesMe-FPP is accommodated in a large hydrophobic cleft starting from HexB and penetrating to the inside of HexA. These structural features suggest that HexB catalyzes the condensation reactions and that HexA is directly involved in the product chain length control in cooperation with HexB.

21 CFR 177.1210 - Closures with sealing gaskets for food containers.

Science.gov (United States)

2010-04-01

... cetyl sulfate 1 percent. Sodium decylbenzenesulfonate Do. Sodium decyl sulfate Do. Sodium formaldehyde sulfoxylate 0.05 percent. Sodium lauryl sulfate 1 percent. Sodium lignin sulfonate 0.2 percent. Sodium myristyl sulfate (sodium tetradecyl sulfate) 0.6 percent. Sodium nitrite 0.2 percent; for use only in...

Acidic Pretreatment of Wheat Straw in Decanol for the Production of Surfactant, Lignin and Glucose

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Boris Estrine

2011-12-01

Full Text Available Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted during a single step operation into decyl pentoside surfactants and the remaining material has been preserved keeping all its promises as potential feedstock for fuels or value added platform chemicals such as hydroxymethylfurfural (HMF. The enzymatic digestibility of the cellulose contained in the straw residue has been evaluated and the lignin prepared from the material characterized. Wheat-based surfactants thus obtained have exhibited superior surface properties compared to fossil-based polyethoxylates decyl alcohol or alkyl oligoglucosides, some of which are largely used surfactants. In view of the growing importance of renewable resource-based molecules in the chemical industry, this approach may open a new avenue for the conversion of wheat straw into various chemicals.

Complete dechlorination of 2,4-dichlorophenol in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel composite electrode

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhirong, E-mail: zrsun@bjut.edu.cn [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Wei, Xuefeng; Han, Yanbo; Tong, Shan [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Hu, Xiang, E-mail: huxiang99@163.com [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

2013-01-15

Highlights: ► Pd/PPy-CTAB/foam-Ni electrode with high surface area and low Pd content was prepared. ► The composite electrode was applied to dechlorination of 2,4-DCP in aqueous solution. ► Complete dechlorination of 2,4-DCP was achieved with higher current efficiency. ► Removal efficiency kept 100% after 10 times dechlorination on the stable electrode. ► The electrochemically reductive activation energy was 25.8 kJ mol{sup −1} in this system. -- Abstract: The electrochemically reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel electrode (Pd/PPy-CTAB/foam-Ni electrode) was investigated in this paper. Pd/PPy-CTAB/foam-Ni electrode was prepared and characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The influences of some experimental factors such as the dechlorination current, dechlorination time and the initial pH on the removal efficiency and the current efficiency of 2,4-DCP dechlorination on Pd/PPy-CTAB/foam-Ni electrode were studied. Complete removal of 2,4-DCP was achieved and the current efficiency of 47.4% could be obtained under the conditions of the initial pH of 2.2, the dechlorination current of 5 mA and the dechlorination time of 50 min when the initial 2,4-DCP concentration was 100 mg L{sup −1}. The analysis of high performance liquid chromatography (HPLC) identified that the intermediate products were 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP). The final products were mainly phenol. Its further reduction product cyclohexanone was also detected. The electrocatalytic dechlorination pathways of 2,4-DCP on Pd/PPy-CTAB/foam-Ni electrode were discussed. The stability of the electrode was favorable that it could keep dechlorination efficiency at 100% after having been reused

The first family with Tay-Sachs disease in Cyprus: Genetic analysis reveals a nonsense (c.78G>A) and a silent (c.1305C>T) mutation and allows preimplantation genetic diagnosis.

Science.gov (United States)

Georgiou, Theodoros; Christopoulos, George; Anastasiadou, Violetta; Hadjiloizou, Stavros; Cregeen, David; Jackson, Marie; Mavrikiou, Gavriella; Kleanthous, Marina; Drousiotou, Anthi

2014-12-01

Tay-Sachs disease (TSD) is a recessively inherited neurodegenerative disorder caused by mutations in the HEXA gene resulting in β-hexosaminidase A (HEX A) deficiency and neuronal accumulation of GM2 ganglioside. We describe the first patient with Tay-Sachs disease in the Cypriot population, a juvenile case which presented with developmental regression at the age of five. The diagnosis was confirmed by measurement of HEXA activity in plasma, peripheral leucocytes and fibroblasts. Sequencing the HEXA gene resulted in the identification of two previously described mutations: the nonsense mutation c.78G>A (p.Trp26X) and the silent mutation c.1305C>T (p.=). The silent mutation was reported once before in a juvenile TSD patient of West Indian origin with an unusually mild phenotype. The presence of this mutation in another juvenile TSD patient provides further evidence that it is a disease-causing mutation. Successful preimplantation genetic diagnosis (PGD) and prenatal follow-up were provided to the couple.

21 CFR 178.3480 - Fatty alcohols, synthetic.

Science.gov (United States)

2010-04-01

... derived lauryl alcohol permitted as an intermediate in the synthesis of sodium lauryl sulfate used in..._locations.html. (1) Synthetic fatty alcohols. (i) Hexyl, octyl, decyl, lauryl, myristyl, cetyl, and stearyl... they may contain not more than 0.8 weight percent total diols. (ii) Lauryl, myristyl, cetyl, and...

p38 MAPK activation and H3K4 trimethylation is decreased by lactate in vitro and high intensity resistance training in human skeletal muscle.

Directory of Open Access Journals (Sweden)

Lena Willkomm

Full Text Available Exercise induces adaptation of skeletal muscle by acutely modulating intracellular signaling, gene expression, protein turnover and myogenic activation of skeletal muscle stem cells (Satellite cells, SCs. Lactate (La-induced metabolic stimulation alone has been shown to modify SC proliferation and differentiation. Although the mechanistic basis remains elusive, it was demonstrated that La affects signaling via p38 mitogen activated protein kinase (p38 MAPK which might contribute to trimethylation of histone 3 lysine 4 (H3K4me3 known to regulate satellite cell proliferation and differentiation. We investigated the effects of La on p38 MAPK and H3K4me3 in a model of activated SCs. Differentiating C2C12 myoblasts were treated with La (20 mM and samples analysed using qRT-PCR, immunofluorescence, and western blotting. We determined a reduction of p38 MAPK phosphorylation, decreased H3K4me3 and reduced expression of Myf5, myogenin, and myosin heavy chain (MHC leading to decreased differentiation of La-treated C2C12 cells after 5 days of repeated La treatment. We further investigated whether this regulatory pathway would be affected in human skeletal muscle by the application of two different resistance exercise regimes (RE associated with distinct metabolic demands and blood La accumulation. Muscle biopsies were obtained 15, 30 min, 1, 4, and 24 h post exercise after moderate intensity RE (STD vs. high intensity RE (HIT. Consistent with in vitro results, reduced p38 phosphorylation and blunted H3K4me3 were also observed upon metabolically demanding HIT RE in human skeletal muscle. Our data provide evidence that La-accumulation acutely affects p38 MAPK signaling, gene expression and thereby cell differentiation and adaptation in vitro, and likely in vivo.

p38 MAPK activation and H3K4 trimethylation is decreased by lactate in vitro and high intensity resistance training in human skeletal muscle.

Science.gov (United States)

Willkomm, Lena; Gehlert, Sebastian; Jacko, Daniel; Schiffer, Thorsten; Bloch, Wilhelm

2017-01-01

Exercise induces adaptation of skeletal muscle by acutely modulating intracellular signaling, gene expression, protein turnover and myogenic activation of skeletal muscle stem cells (Satellite cells, SCs). Lactate (La)-induced metabolic stimulation alone has been shown to modify SC proliferation and differentiation. Although the mechanistic basis remains elusive, it was demonstrated that La affects signaling via p38 mitogen activated protein kinase (p38 MAPK) which might contribute to trimethylation of histone 3 lysine 4 (H3K4me3) known to regulate satellite cell proliferation and differentiation. We investigated the effects of La on p38 MAPK and H3K4me3 in a model of activated SCs. Differentiating C2C12 myoblasts were treated with La (20 mM) and samples analysed using qRT-PCR, immunofluorescence, and western blotting. We determined a reduction of p38 MAPK phosphorylation, decreased H3K4me3 and reduced expression of Myf5, myogenin, and myosin heavy chain (MHC) leading to decreased differentiation of La-treated C2C12 cells after 5 days of repeated La treatment. We further investigated whether this regulatory pathway would be affected in human skeletal muscle by the application of two different resistance exercise regimes (RE) associated with distinct metabolic demands and blood La accumulation. Muscle biopsies were obtained 15, 30 min, 1, 4, and 24 h post exercise after moderate intensity RE (STD) vs. high intensity RE (HIT). Consistent with in vitro results, reduced p38 phosphorylation and blunted H3K4me3 were also observed upon metabolically demanding HIT RE in human skeletal muscle. Our data provide evidence that La-accumulation acutely affects p38 MAPK signaling, gene expression and thereby cell differentiation and adaptation in vitro, and likely in vivo.

Glucose-independent persistence of PAI-1 gene expression and H3K4 tri-methylation in type 1 diabetic mouse endothelium: implication in metabolic memory.

Science.gov (United States)

Takizawa, Fumihiko; Mizutani, Shuki; Ogawa, Yoshihiro; Sawada, Naoki

2013-03-29

Clinical trials with type 1 and type 2 diabetes have identified a phenomenon known as "metabolic memory" in which previous periods of hyperglycemia result in the long-lasting deleterious impact on cardiovascular events. Emerging evidence shows that transient hyperglycemic exposure of human endothelial cells induces histone 3 lysine 4 mono-methylation (H3K4me1) on the promoter and persistent mRNA expression of RelA and IL-8 genes, suggesting that epigenetic histone modification and chromatin structure remodeling is a key event underlying metabolic memory. This burgeoning hypothesis, however, critically remains to be tested for relevance in the disease process of diabetes in vivo, and for broader applicability to an array of genes involved in endothelial dysfunction. To address this, we used type 1 diabetes mouse model induced by streptozocin to be hyperglycemic for 8 weeks, and isolated endothelial cells that were used either freshly after isolation or after 2 to 3-week cell culture in normoglycemic conditions. mRNA expression profiling in diabetic mouse endothelial cells revealed significant and persistent up-regulation of Serpine1 encoding PAI-1, the hypo-fibrinolytic mediator leading to thrombotic diseases in diabetes, along with Rock2, Fn1 and Ccl2, whereas only Serpine 1 was persistently elevated in high glucose-treated mouse endothelial cells. Chromosome immunoprecipitation assay in type 1 diabetic mouse endothelial cells showed predominant enrichment of H3K4 tri-methylation on Serpine1 promoter, suggesting a unique epigenetic regulation in diabetic mice as opposed to high glucose-treated human ECs. Our study demonstrates the importance of combining in vivo models of diabetes with high glucose-treated cell culture to better assess the epigenetic mechanisms relevant to disease. Copyright © 2013 Elsevier Inc. All rights reserved.

Interaction of (NH4)2ZrF6 and (NH4)3ZrF7 with strontium and lead nitrates

International Nuclear Information System (INIS)

Krysenko, G.F.; Mel'nichenko, E.I.; Ehpov, D.G.; Polishchuk, S.A.

1991-01-01

Methods of chemical, X-ray phase, thermogravimetric analysis and IR spectroscopy were used to study reactions between ammonium fluorozirconates and strontium and lead nitrates. Formation of anhydrous hexa- and octafluorozirconates of strontium and lead in the form of MZrF 6 ·0.5NH 4 F and M 2 ZrF 8 ·0.5NH 4 F double salts, which decompose at 315-430 deg C to corresponding hexa- and octafluorozirconates, was established. Effect of hydrofluoric acid on composition of lead fluorozirconates was studied

OCTANOL/WATER PARTITION COEFFICIENTS AND WATER SOLUBILITIES OF PHTHALATE ESTERS

Science.gov (United States)

Measurements of the octanol/water partition coefficients (K-ow) and water solubilities of di-n-octyl phthalate (DnOP) and di-n-decyl phthalate (DnDP) by the slow-stirring method are reported. The water solubility was also measured for di-n-hexyl phthalate (DnHP). The log K-ow val...

Tumor tracking and motion compensation with an adaptive tumor tracking system (ATTS): System description and prototype testing

International Nuclear Information System (INIS)

Wilbert, Juergen; Meyer, Juergen; Baier, Kurt; Guckenberger, Matthias; Herrmann, Christian; Hess, Robin; Janka, Christian; Ma Lei; Mersebach, Torben; Richter, Anne; Roth, Michael; Schilling, Klaus; Flentje, Michael

2008-01-01

A novel system for real-time tumor tracking and motion compensation with a robotic HexaPOD treatment couch is described. The approach is based on continuous tracking of the tumor motion in portal images without implanted fiducial markers, using the therapeutic megavoltage beam, and tracking of abdominal breathing motion with optical markers. Based on the two independently acquired data sets the table movements for motion compensation are calculated. The principle of operation of the entire prototype system is detailed first. In the second part the performance of the HexaPOD couch was investigated with a robotic four-dimensional-phantom capable of simulating real patient tumor trajectories in three-dimensional space. The performance and limitations of the HexaPOD table and the control system were characterized in terms of its dynamic behavior. The maximum speed and acceleration of the HexaPOD were 8 mm/s and 34.5 mm/s 2 in the lateral direction, and 9.5 mm/s and 29.5 mm/s 2 in longitudinal and anterior-posterior direction, respectively. Base line drifts of the mean tumor position of realistic lung tumor trajectories could be fully compensated. For continuous tumor tracking and motion compensation a reduction of tumor motion up to 68% of the original amplitude was achieved. In conclusion, this study demonstrated that it is technically feasible to compensate breathing induced tumor motion in the lung with the adaptive tumor tracking system

Antibacterial properties of 3 H-spiro[1-benzofuran-2,1'-cyclohexane] derivatives from Heliotropium filifolium.

Science.gov (United States)

Urzúa, Alejandro; Echeverría, Javier; Rezende, Marcos C; Wilkens, Marcela

2008-10-01

A re-examination of cuticular components of Heliotropium filifolium allowed the isolation of four new compounds: 3'-hydroxy-2',2',6'-trimethyl-3H-spiro[1-benzo-furan-2,1'-cyclohexane]-5-carboxylic acid(2), methyl 3'-acetyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carboxylate (3), methyl 3'-isopentanoyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carboxylate (4) and methyl 3'-benzoyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carboxylate (5).Compounds 2-5 were identified by their spectroscopic analogies with filifolinol (1), and their structures confirmed by chemical correlation with 1. The antimicrobial properties of the compounds were tested against Gram positive and Gram negative bacteria. Some of them proved to be active against Gram positive, but inactive against Gram negative bacteria. In searching for structure-activity relationships from the obtained MIC values, lipophilicity was shown to be an important variable.

Induced alignment of a solution-cast discotic hexabenzocoronene derivative for electronic devices investigated by surface X-ray diffraction

DEFF Research Database (Denmark)

Bunk, Oliver; Nielsen, Martin Meedom; Sølling, Theis Ivan

2003-01-01

A surface X-ray diffraction study is presented showing that highly ordered and uniaxially aligned hexa(3,7-dimethyl-octanyl)hexa-peri-hexabenzocoronene (HBC-C8,2) films can be fabricated by crystallization from solution onto friction-transferred poly(tetrafluoroethylene) (PTFE) layers. Three...... crystalline HBC-C8,2 majority phases result. In all three phases, the HBC-C8,2 molecules self-organize into columns which are uniaxially aligned along the direction defined by the PTFE macromolecules of the substrate. The three phases are quite similar, the major difference being their orientation...

Intrinsic acid-base properties of a hexa-2'-deoxynucleoside pentaphosphate, d(ApGpGpCpCpT): neighboring effects and isomeric equilibria.

Science.gov (United States)

Domínguez-Martín, Alicia; Johannsen, Silke; Sigel, Astrid; Operschall, Bert P; Song, Bin; Sigel, Helmut; Okruszek, Andrzej; González-Pérez, Josefa María; Niclós-Gutiérrez, Juan; Sigel, Roland K O

2013-06-17

The intrinsic acid-base properties of the hexa-2'-deoxynucleoside pentaphosphate, d(ApGpGpCpCpT) [=(A1∙G2∙G3∙C4∙C5∙T6)=(HNPP)⁵⁻] have been determined by ¹H NMR shift experiments. The pKa values of the individual sites of the adenosine (A), guanosine (G), cytidine (C), and thymidine (T) residues were measured in water under single-strand conditions (i.e., 10% D₂O, 47 °C, I=0.1 M, NaClO₄). These results quantify the release of H⁺ from the two (N7)H⁺ (G∙G), the two (N3)H⁺ (C∙C), and the (N1)H⁺ (A) units, as well as from the two (N1)H (G∙G) and the (N3)H (T) sites. Based on measurements with 2'-deoxynucleosides at 25 °C and 47 °C, they were transferred to pKa values valid in water at 25 °C and I=0.1 M. Intramolecular stacks between the nucleobases A1 and G2 as well as most likely also between G2 and G3 are formed. For HNPP three pKa clusters occur, that is those encompassing the pKa values of 2.44, 2.97, and 3.71 of G2(N7)H⁺, G3(N7)H⁺, and A1(N1)H⁺, respectively, with overlapping buffer regions. The tautomer populations were estimated, giving for the release of a single proton from five-fold protonated H₅(HNPP)(±) , the tautomers (G2)N7, (G3)N7, and (A1)N1 with formation degrees of about 74, 22, and 4%, respectively. Tautomer distributions reveal pathways for proton-donating as well as for proton-accepting reactions both being expected to be fast and to occur practically at no "cost". The eight pKa values for H₅(HNPP)(±) are compared with data for nucleosides and nucleotides, revealing that the nucleoside residues are in part affected very differently by their neighbors. In addition, the intrinsic acidity constants for the RNA derivative r(A1∙G2∙G3∙C4∙C5∙U6), where U=uridine, were calculated. Finally, the effect of metal ions on the pKa values of nucleobase sites is briefly discussed because in this way deprotonation reactions can easily be shifted to the physiological pH range. Copyright © 2013 WILEY

Novel Vector Design and Hexosaminidase Variant Enabling Self-Complementary Adeno-Associated Virus for the Treatment of Tay-Sachs Disease.

Science.gov (United States)

Karumuthil-Melethil, Subha; Nagabhushan Kalburgi, Sahana; Thompson, Patrick; Tropak, Michael; Kaytor, Michael D; Keimel, John G; Mark, Brian L; Mahuran, Don; Walia, Jagdeep S; Gray, Steven J

2016-07-01

GM2 gangliosidosis is a family of three genetic neurodegenerative disorders caused by the accumulation of GM2 ganglioside (GM2) in neuronal tissue. Two of these are due to the deficiency of the heterodimeric (α-β), "A" isoenzyme of lysosomal β-hexosaminidase (HexA). Mutations in the α-subunit (encoded by HEXA) lead to Tay-Sachs disease (TSD), whereas mutations in the β-subunit (encoded by HEXB) lead to Sandhoff disease (SD). The third form results from a deficiency of the GM2 activator protein (GM2AP), a substrate-specific cofactor for HexA. In their infantile, acute forms, these diseases rapidly progress with mental and psychomotor deterioration resulting in death by approximately 4 years of age. After gene transfer that overexpresses one of the deficient subunits, the amount of HexA heterodimer formed would empirically be limited by the availability of the other endogenous Hex subunit. The present study used a new variant of the human HexA α-subunit, μ, incorporating critical sequences from the β-subunit that produce a stable homodimer (HexM) and promote functional interactions with the GM2AP- GM2 complex. We report the design of a compact adeno-associated viral (AAV) genome using a synthetic promoter-intron combination to allow self-complementary (sc) packaging of the HEXM gene. Also, a previously published capsid mutant, AAV9.47, was used to deliver the gene to brain and spinal cord while having restricted biodistribution to the liver. The novel capsid and cassette design combination was characterized in vivo in TSD mice for its ability to efficiently transduce cells in the central nervous system when delivered intravenously in both adult and neonatal mice. This study demonstrates that the modified HexM is capable of degrading long-standing GM2 storage in mice, and it further demonstrates the potential of this novel scAAV vector design to facilitate widespread distribution of the HEXM gene or potentially other similar-sized genes to the nervous system.

Molecular Evolution of the Substrate Specificity of Chloroplastic Aldolases/Rubisco Lysine Methyltransferases in Plants.

Science.gov (United States)

Ma, Sheng; Martin-Laffon, Jacqueline; Mininno, Morgane; Gigarel, Océane; Brugière, Sabine; Bastien, Olivier; Tardif, Marianne; Ravanel, Stéphane; Alban, Claude

2016-04-04

Rubisco and fructose-1,6-bisphosphate aldolases (FBAs) are involved in CO2 fixation in chloroplasts. Both enzymes are trimethylated at a specific lysine residue by the chloroplastic protein methyltransferase LSMT. Genes coding LSMT are present in all plant genomes but the methylation status of the substrates varies in a species-specific manner. For example, chloroplastic FBAs are naturally trimethylated in both Pisum sativum and Arabidopsis thaliana, whereas the Rubisco large subunit is trimethylated only in the former species. The in vivo methylation status of aldolases and Rubisco matches the catalytic properties of AtLSMT and PsLSMT, which are able to trimethylate FBAs or FBAs and Rubisco, respectively. Here, we created chimera and site-directed mutants of monofunctional AtLSMT and bifunctional PsLSMT to identify the molecular determinants responsible for substrate specificity. Our results indicate that the His-Ala/Pro-Trp triad located in the central part of LSMT enzymes is the key motif to confer the capacity to trimethylate Rubisco. Two of the critical residues are located on a surface loop outside the methyltransferase catalytic site. We observed a strict correlation between the presence of the triad motif and the in vivo methylation status of Rubisco. The distribution of the motif into a phylogenetic tree further suggests that the ancestral function of LSMT was FBA trimethylation. In a recent event during higher plant evolution, this function evolved in ancestors of Fabaceae, Cucurbitaceae, and Rosaceae to include Rubisco as an additional substrate to the archetypal enzyme. Our study provides insight into mechanisms by which SET-domain protein methyltransferases evolve new substrate specificity. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

In silico probing and biological evaluation of SETDB1/ESET-targeted novel compounds that reduce tri-methylated histone H3K9 (H3K9me3) level

Science.gov (United States)

Park, Insun; Hwang, Yu Jin; Kim, TaeHun; Viswanath, Ambily Nath Indu; Londhe, Ashwini M.; Jung, Seo Yun; Sim, Kyoung Mi; Min, Sun-Joon; Lee, Ji Eun; Seong, Jihye; Kim, Yun Kyung; No, Kyoung Tai; Ryu, Hoon; Pae, Ae Nim

2017-10-01

ERG-associated protein with the SET domain (ESET/SET domain bifurcated 1/SETDB1/KMT1E) is a histone lysine methyltransferase (HKMT) and it preferentially tri-methylates lysine 9 of histone H3 (H3K9me3). SETDB1/ESET leads to heterochromatin condensation and epigenetic gene silencing. These functional changes are reported to correlate with Huntington's disease (HD) progression and mood-related disorders which make SETDB1/ESET a viable drug target. In this context, the present investigation was performed to identify novel peptide-competitive small molecule inhibitors of the SETDB1/ESET by a combined in silico-in vitro approach. A ligand-based pharmacophore model was built and employed for the virtual screening of ChemDiv and Asinex database. Also, a human SETDB1/ESET homology model was constructed to supplement the data further. Biological evaluation of the selected 21 candidates singled out 5 compounds exhibiting a notable reduction of the H3K9me3 level via inhibitory potential of SETDB1/ESET activity in SETDB1/ESET-inducible cell line and HD striatal cells. Later on, we identified two compounds as final hits that appear to have neuronal effects without cytotoxicity based on the result from MTT assay. These compounds hold the calibre to become the future lead compounds and can provide structural insights into more SETDB1/ESET-focused drug discovery research. Moreover, these SETDB1/ESET inhibitors may be applicable for the preclinical study to ameliorate neurodegenerative disorders via epigenetic regulation.

In silico probing and biological evaluation of SETDB1/ESET-targeted novel compounds that reduce tri-methylated histone H3K9 (H3K9me3) level.

Science.gov (United States)

Park, Insun; Hwang, Yu Jin; Kim, TaeHun; Viswanath, Ambily Nath Indu; Londhe, Ashwini M; Jung, Seo Yun; Sim, Kyoung Mi; Min, Sun-Joon; Lee, Ji Eun; Seong, Jihye; Kim, Yun Kyung; No, Kyoung Tai; Ryu, Hoon; Pae, Ae Nim

2017-10-01

ERG-associated protein with the SET domain (ESET/SET domain bifurcated 1/SETDB1/KMT1E) is a histone lysine methyltransferase (HKMT) and it preferentially tri-methylates lysine 9 of histone H3 (H3K9me3). SETDB1/ESET leads to heterochromatin condensation and epigenetic gene silencing. These functional changes are reported to correlate with Huntington's disease (HD) progression and mood-related disorders which make SETDB1/ESET a viable drug target. In this context, the present investigation was performed to identify novel peptide-competitive small molecule inhibitors of the SETDB1/ESET by a combined in silico-in vitro approach. A ligand-based pharmacophore model was built and employed for the virtual screening of ChemDiv and Asinex database. Also, a human SETDB1/ESET homology model was constructed to supplement the data further. Biological evaluation of the selected 21 candidates singled out 5 compounds exhibiting a notable reduction of the H3K9me3 level via inhibitory potential of SETDB1/ESET activity in SETDB1/ESET-inducible cell line and HD striatal cells. Later on, we identified two compounds as final hits that appear to have neuronal effects without cytotoxicity based on the result from MTT assay. These compounds hold the calibre to become the future lead compounds and can provide structural insights into more SETDB1/ESET-focused drug discovery research. Moreover, these SETDB1/ESET inhibitors may be applicable for the preclinical study to ameliorate neurodegenerative disorders via epigenetic regulation.

Di-μ-cyanido-tetra­cyanido(5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane)[N-(quinolin-8-yl)quinoline-2-carboxamidato]diiron(III)nickel(II) 2.07-hydrate

Science.gov (United States)

Yang, Yuqi; Zhou, Hongbo; Shen, Xiaoping

2013-01-01

The asymmetric unit of the title complex, [Fe2Ni(C19H12N3O)2(CN)6(C16H36N4)]·2.07H2O, contains one [Fe(qcq)(CN)3]− anion, half a [Ni(teta)]2+ cation and two partially occupied inter­stitial water mol­ecules [qcq− is the N-(quinolin-8-yl)quinoline-2-carboxamidate anion and teta is 5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­deca­ne]. In the complex mol­ecule, two [Fe(qcq)(CN)3]− anions additionally coordinate the central [Ni(teta)]2+ cation through cyanide groups in a trans mode, resulting in a trinuclear structure with the Ni2+ cation lying on an inversion centre. The two inter­stitial water mol­ecules are partially occupied, with occupancy factors of 0.528 (10) and 0.506 (9). O—H⋯O and O—H⋯N hydrogen bonding involving the two lattice water molecules and the carbonyl function and a teta N atom in an adjacent cluster leads to the formation of layers extending parallel to (010). PMID:23723777

Isolation and identification of an allelopathic substance from Hibiscus sabdariffa.

Science.gov (United States)

Suwitchayanon, Prapaipit; Pukclai, Piyatida; Ohno, Osamu; Suenaga, Kiyotake; Kato-Noguchi, Hisashi

2015-05-01

In this study, an allelopathic substance was isolated from an aqueous methanol extract of Hibiscus sabdariffa L. by column chromatography and reverse phase HPLC. The chemical structure of the substance was determined by 1H NMR spectroscopy and mass spectrometry as trimethyl allo-hydroxycitrate. Trimethyl allo-hydroxycitrate inhibited the growth of cress hypocotyls and roots at concentrations greater than 10 mM. The concentrations required for 50% growth inhibition of the hypocotyls and roots of cress were 20.3 and 14.4 mM, respectively. The inhibitory activity of trimethyl allo-hydroxycitrate suggests that the substance may act as an allelopathic substance of H. sabdariffa.

Photoelectron spectroscopy of phosphites and phosphates

Energy Technology Data Exchange (ETDEWEB)

Chattopadhyay, S.; Findley, G.L.; McGlynn, S.P.

1981-01-01

The ultraviolet photoelectron spectra (UPS) of trimethyl and triethyl phosphite, trimethyl and triethyl phosphate and four substituted phosphates are presented. Assignments are based on analogies to the UPS of phosphorus trichloride and phosphoryl trichloride and are substantiated by CNDO/2 computations. The mechanisms of P-O (axial) bond formation is discussed.

Detailed analysis of polybrominated biphenyl congeners in bird eggs from Norway

International Nuclear Information System (INIS)

Vetter, Walter; Recke, Roland von der; Herzke, Dorte; Nygard, Torgeir

2008-01-01

Individual eggs of six species of birds from Norway representing different food chains were analysed for residues of polybrominated biphenyls (PBBs). In all species, the residue pattern was dominated by hexaBBs. The dominating congeners were PBB 153, PBB 154, and PBB 155. Whereas PBB 153 is present in technical hexabromobiphenyl, PBB 154 and PBB 155 are formed by the reductive debromination of decabromobiphenyl. This was evidenced by the detection of several heptaBBs and octaBBs all of which are typical degradation intermediates of PBB 209. Hepta- and octaBBs were more than one order of magnitude less abundant than the hexaBBs. The second most prevailing homologue group was pentaBBs. The most relevant pentabrominated isomers were PBB 99 and PBB 101. Concentrations of the three hexaBBs - PBB 153, PBB 154, and PBB 155 - amounted to 1.3-13 ng/g wet weight or 3-23% of the contamination with polybrominated diphenyl ethers. - We provide for the first time detailed information on the PBB congeners present in eggs of bird of prey, and quantified three hexabromo congeners

AGARD Corrosion Handbook. Volume 1. Aircraft Corrosion: Causes and Case Histories

Science.gov (United States)

1985-07-01

the first scientist who originally isolated the fungus in Germany from the resin Pinus excelsior and named it Harmodendrum resinae Lindau (Ref. 15...mixture of two organic compounds: 2,2’-oxybis(4,4,6-trimethyl-l,3,2-dioxaborinane)and 2,2’-(l-methyltrimethylenedioxy)bis-(4- methyl -l,3,2-dioxaborinane

Tay-Sachs disease in Jacob sheep.

Science.gov (United States)

Torres, Paola A; Zeng, Bai Jin; Porter, Brian F; Alroy, Joseph; Horak, Fred; Horak, Joan; Kolodny, Edwin H

2010-12-01

Autopsy studies of four Jacob sheep dying within their first 6-8 months of a progressive neurodegenerative disorder suggested the presence of a neuronal storage disease. Lysosomal enzyme studies of brain and liver from an affected animal revealed diminished activity of hexosaminidase A (Hex A) measured with an artificial substrate specific for this component of β-hexosaminidase. Absence of Hex A activity was confirmed by cellulose acetate electrophoresis. Brain lipid analyses demonstrated the presence of increased concentrations of G(M2)-ganglioside and asialo-G(M2)-ganglioside. The hexa cDNA of Jacob sheep was cloned and sequenced revealing an identical number of nucleotides and exons as in human HexA and 86% homology in nucleotide sequence. A missense mutation was found in the hexa cDNA of the affected sheep caused by a single nucleotide change at the end of exon 11 resulting in skipping of exon 11. Transfection of normal sheep hexa cDNA into COS1 cells and human Hex A-deficient cells led to expression of Hex S but no increase in Hex A indicating absence of cross-species dimerization of sheep Hex α-subunit with human Hex β-subunits. Using restriction site analysis, the heterozygote frequency of this mutation in Jacob sheep was determined in three geographically separate flocks to average 14%. This large naturally occurring animal model of Tay-Sachs disease is the first to offer promise as a means for trials of gene therapy applicable to human infants. Copyright © 2010 Elsevier Inc. All rights reserved.

Synthesis, characterization, and antibacterial activity of N,O-quaternary ammonium chitosan.

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Xu, Tao; Xin, Meihua; Li, Mingchun; Huang, Huili; Zhou, Shengquan; Liu, Juezhao

2011-11-08

N,N,N-Trimethyl O-(2-hydroxy-3-trimethylammonium propyl) chitosans (TMHTMAPC) with different degrees of O-substitution were synthesized by reacting O-methyl-free N,N,N-trimethyl chitosan (TMC) with 3-chloro-2-hydroxy-propyl trimethyl ammonium chloride (CHPTMAC). The products were characterized by (1)H NMR, FTIR and TGA, and investigated for antibacterial activity against Staphylococcus aureus and Escherichia coli under weakly acidic (pH 5.5) and weakly basic (pH 7.2) conditions. TMHTMAPC exhibited enhanced antibacterial activity compared with TMC, and the activity of TMHTMAPC increased with an increase in the degree of substitution. Divalent cations (Ba(2+) and Ca(2+)) strongly reduced the antibacterial activity of chitosan, O-carboxymethyl chitosan and N,N,N-trimethyl-O-carboxymethyl chitosan, but the repression on the antibacterial activity of TMC and TMHTMAPC was weaker. This indicates that the free amino group on chitosan backbone is the main functional group interacting with divalent cations. The existence of 100 mM Na(+) slightly reduced the antibacterial activity of both chitosan and its derivatives. Copyright © 2011 Elsevier Ltd. All rights reserved.

Study of a magnetically oriented lyotropic mesophase

International Nuclear Information System (INIS)

Amaral, L.Q.; Pimentel, C.A.; Tavares, M.R.; Vanin, J.A.

A study of a magnetically oriented lyomesophase formed by a quaternary system (Na decyl sulfate/water/decanol/ Na sulfate) is reported. Small angle X-ray diffraction measurements have been performed on unoriented samples and samples previously subjected to the action of magnetic fields (H vector). A model of finite planar micelles surrounded by water is proposed [pt

Kinetic, stereochemical, and molecular association factors in the hydralumination of group IV subtituted alkynes. The role of p/sub π/-d/sub π/ conjugation in the addition of diisobutylaluminum hydride to trimethyl(phenylethynyl)silane

International Nuclear Information System (INIS)

Eisch, J.J.; Rhee, S.G.

1975-01-01

The kinetic, stereochemistry, and molecular association factors for the addition of diisobutylaluminum hydride to trimethyl(phenylethynyl)silane were studied in the temperature range of -10 to 38 0 . Hydralumination was found to have a kinetic true order of essentially one in the alkyne and one-third in the hydride. Although the trans adduct is the predominating product (approximately 99 percent) after completion of the hydralumination, the variation of the proportion of cis adduct and the initial rate law are consistent with a kinetically controlled cis hydralumination by monomeric R 2 'AlH, followed by a rapid isomerization to the trans adduct. The trans adduct formed a complex with l equivalent to the hydride. This complexation had to be taken into account, in order to explain the observed rate retardation and to obtain satisfactory integrated rate expressions for hydraluminations monitored to high conversion. Since in hydralumination this silylacetylene shows a stereospecificity and regiospecificity exactly opposite that of tert-butyl(phenyl)acetylene, as well as a heightened reactivity, a critical consideration of possible p/sub π/--d/sub π/ electronic effects was undertaken. The unusually facile isomerization of the resulting silyl-substituted vinylalanes, however, does seem more persuasive evidence for a p/sub π/--d/sub π/ effect, which promotes isomerization by electrophilic attack of R 2 'AlH on the carbon α to the Me 3 Si group. (U.S.)

Amide and Ester-Functionalized Humic Acid for Fuel Combustion Enhancement

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Riggs, Mark

Humic acid is a class of naturally occurring molecules composed of large sheet-like regions of cyclic aromatic hydrocarbon networks with surface and edge functional groups including phenols, carboxylic acids, and epoxides. These naturally occurring molecules are found in brown coal deposits near lignite formations. Humic acid has gained attention from the scientific community as a precursor for graphene. Graphene is a 2-dimensional honeycomb structure of fully unsaturated carbon atoms that has exceptional material properties and inherent aromaticity. Graphene's incredible properties are matched by the difficulty associated with reproducibly manufacturing it on a large scale. This issue has limited the use of graphene for commercial applications. The polar functional groups of humic acid contribute to the hydrophilic nature of the molecule, limiting its miscibility in any alkyl-based solvent. Surfactants containing long alkyl chains can affect the miscibility of the molecule in an organic solvent. Surfactants are often difficult to remove from the system. It is theorized that alkylation of the functional sites of humic acid can affect the hydrophilic nature of the molecule, and effectively enable its dispersion into organic solvents without simultaneous incorporation of surfactants. This dissertation investigated the amidation and esterification of humic acid molecules extracted from leonardite. The resulting change in the modified humic acid dispersibility in organic solvents and its potential usage as a fuel additive were evaluated. Butyl, hexyl, octyl, and decyl amide-modified and ester-modified humic acids were synthesized. These products were characterized to confirm successful chemical reaction through thermogravimetric analysis, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The decyl-modified humic acids remained suspended in kerosene mixtures for longer than 1 week. Other organo-humic acids showed varying degrees of flocculation

KdmB, a Jumonji Histone H3 Demethylase, Regulates Genome-Wide H3K4 Trimethylation and Is Required for Normal Induction of Secondary Metabolism in Aspergillus nidulans.

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Agnieszka Gacek-Matthews

2016-08-01

Full Text Available Histone posttranslational modifications (HPTMs are involved in chromatin-based regulation of fungal secondary metabolite biosynthesis (SMB in which the corresponding genes-usually physically linked in co-regulated clusters-are silenced under optimal physiological conditions (nutrient-rich but are activated when nutrients are limiting. The exact molecular mechanisms by which HPTMs influence silencing and activation, however, are still to be better understood. Here we show by a combined approach of quantitative mass spectrometry (LC-MS/MS, genome-wide chromatin immunoprecipitation (ChIP-seq and transcriptional network analysis (RNA-seq that the core regions of silent A. nidulans SM clusters generally carry low levels of all tested chromatin modifications and that heterochromatic marks flank most of these SM clusters. During secondary metabolism, histone marks typically associated with transcriptional activity such as H3 trimethylated at lysine-4 (H3K4me3 are established in some, but not all gene clusters even upon full activation. KdmB, a Jarid1-family histone H3 lysine demethylase predicted to comprise a BRIGHT domain, a zinc-finger and two PHD domains in addition to the catalytic Jumonji domain, targets and demethylates H3K4me3 in vivo and mediates transcriptional downregulation. Deletion of kdmB leads to increased transcription of about ~1750 genes across nutrient-rich (primary metabolism and nutrient-limiting (secondary metabolism conditions. Unexpectedly, an equally high number of genes exhibited reduced expression in the kdmB deletion strain and notably, this group was significantly enriched for genes with known or predicted functions in secondary metabolite biosynthesis. Taken together, this study extends our general knowledge about multi-domain KDM5 histone demethylases and provides new details on the chromatin-level regulation of fungal secondary metabolite production.

Epigenetics and sex differences in the brain: A genome-wide comparison of histone-3 lysine-4 trimethylation (H3K4me3) in male and female mice.

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Shen, Erica Y; Ahern, Todd H; Cheung, Iris; Straubhaar, Juerg; Dincer, Aslihan; Houston, Isaac; de Vries, Geert J; Akbarian, Schahram; Forger, Nancy G

2015-06-01

Many neurological and psychiatric disorders exhibit gender disparities, and sex differences in the brain likely explain some of these effects. Recent work in rodents points to a role for epigenetics in the development or maintenance of neural sex differences, although genome-wide studies have so far been lacking. Here we review the existing literature on epigenetics and brain sexual differentiation and present preliminary analyses on the genome-wide distribution of histone-3 lysine-4 trimethylation in a sexually dimorphic brain region in male and female mice. H3K4me3 is a histone mark primarily organized as 'peaks' surrounding the transcription start site of active genes. We microdissected the bed nucleus of the stria terminalis and preoptic area (BNST/POA) in adult male and female mice and used ChIP-Seq to compare the distribution of H3K4me3 throughout the genome. We found 248 genes and loci with a significant sex difference in H3K4me3. Of these, the majority (71%) had larger H3K4me3 peaks in females. Comparisons with existing databases indicate that genes and loci with increased H3K4me3 in females are associated with synaptic function and with expression atlases from related brain areas. Based on RT-PCR, only a minority of genes with a sex difference in H3K4me3 has detectable sex differences in expression at baseline conditions. Together with previous findings, our data suggest that there may be sex biases in the use of epigenetic marks. Such biases could underlie sex differences in vulnerabilities to drugs or diseases that disrupt specific epigenetic processes. Copyright © 2014 Elsevier Inc. All rights reserved.

Histone demethylase JMJD3 regulates CD11a expression through changes in histone H3K27 tri-methylation levels in CD4+ T cells of patients with systemic lupus erythematosus.

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Yin, Heng; Wu, Haijing; Zhao, Ming; Zhang, Qing; Long, Hai; Fu, Siqi; Lu, Qianjin

2017-07-25

Aberrant CD11a overexpression in CD4+ T cells induces T cell auto-reactivity, which is an important factor for systemic lupus erythematosus (SLE) pathogenesis. Although many studies have focused on CD11a epigenetic regulation, little is known about histone methylation. JMJD3, as a histone demethylase, is capable of specifically removing the trimethyl group from the H3K27 lysine residue, triggering target gene activation. Here, we examined the expression and function of JMJD3 in CD4+ T cells from SLE patients. Significantly decreased H3K27me3 levels and increased JMJD3 binding were detected within the ITGAL (CD11a) promoter locus in SLE CD4+ T cells compared with those in healthy CD4+ T cells. Moreover, overexpressing JMJD3 through the transfection of pcDNA3.1-JMJD3 into healthy donor CD4+ T cells increased JMJD3 enrichment and decreased H3K27me3 enrichment within the ITGAL (CD11a) promoter and up-regulated CD11a expression, leading to T and B cell hyperactivity. Inhibition of JMJD3 via JMJD3-siRNA in SLE CD4+ T cells showed the opposite effects. These results demonstrated that histone demethylase JMJD3 regulates CD11a expression in lupus T cells by affecting the H3K27me3 levels in the ITGAL (CD11a) promoter region, and JMJD3 might thereby serve as a potential therapeutic target for SLE.

Functional characterization of the Woronin body protein WscA of the pathogenic mold Aspergillus fumigatus.

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Leonhardt, Yannik; Beck, Julia; Ebel, Frank

2016-05-01

Woronin bodies are fungal-specific organelles that seal damaged hyphal compartments and thereby contribute to the stress resistance and virulence of filamentous fungi. In this study, we have characterized the Aspergillus fumigatus Woronin body protein WscA. WscA is homologous to Neurospora crassa WSC, a protein that was shown to be important for biogenesis, segregation and positioning of Woronin bodies. WscA and WSC both belong to the Mpv17/PMP22 family of peroxisomal membrane proteins. An A. fumigatus ΔwscA mutant is unable to form Woronin bodies, and HexA, the protein that forms the crystal-like core of Woronin bodies, accumulates in large peroxisomes instead. The ΔwscA mutant showed no defect in segregation of HexA containing organelles, as has been reported for the corresponding N. crassa mutant. In the peroxisomes of the A. fumigatus mutant, HexA assembles into compact, donut-shaped structures. Experiments with GFP fusion proteins revealed that WscA function is highly sensitive to these modifications, in particular to an N-terminal fusion of GFP. In N. crassa, WSC was shown to be essentially required for Woronin body positioning, but the respective domain is not conserved in most other Pezizomycotina, including A. fumigatus. We have recently found evidence that HexA may have a direct role in WB positioning, since a HexA-GFP fusion protein, lacking a functional PTS1 motif, is efficiently recruited to the septal pore. In the current study we show that this targeting of HexA-GFP is independent of WscA. Copyright © 2016 Elsevier GmbH. All rights reserved.

Lipid binding to cytoglobin leads to a change in haem co-ordination: a role for cytoglobin in lipid signalling of oxidative stress.

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Reeder, Brandon J; Svistunenko, Dimitri A; Wilson, Michael T

2011-03-15

Cytoglobin is a recently discovered hexa-co-ordinate haemoglobin that does not appear to function as a classical oxygen-binding protein. Its function is unknown and studies on the effects of changes in its expression have not decisively determined its role within the cell. In the present paper, we report that the protein is transformed from hexa-co-ordinate to penta-co-ordinate on binding a lipid molecule. This transformation occurs with the ferric oxidation state of the protein, but not the ferrous state, indicating that this process only occurs under an oxidative environment and may thus be related to redox-linked cell signalling mechanisms. Oleate binds to the protein in a 1:1 stoichiometry and with high affinity (K(d)=0.7 μM); however, stopped-flow kinetic measurements yield a K(d) value of 110 μM. The discrepancy between these K(d) values may be rationalized by recognizing that cytoglobin is a disulfide-linked dimer and invoking co-operativity in oleate binding. The lipid-induced transformation of cytoglobin from hexa-co-ordinate to penta-co-ordinate does not occur with similar hexa-co-ordinate haemoglobins such as neuroglobin, and therefore appears to be a unique property of cytoglobin among the haemoglobin superfamily. The lipid-derived transformation may explain why cytoglobin has enhanced peroxidatic activity, converting lipids into various oxidized products, a property virtually absent from neuroglobin and much decreased in myoglobin. We propose that the binding of ferric cytoglobin to lipids and their subsequent transformation may be integral to the physiological function of cytoglobin, generating cell signalling lipid molecules under an oxidative environment.

Labelling of m-trimethyl silylphenyl-ethylidene-1, i-bisphosphonate with /sup 99m/Tc and its evaluation as an imaging agent

International Nuclear Information System (INIS)

Sajid, K.M.; Mahmood, R.

2012-01-01

Technetium-99m labeled phosphates and phosphonates have since long been in use for bone imaging to diagnose bone infection, bone metastasis and bone fracture. /sup 131/ I -labeled bisphosphonates have also been prepared for targeted radiotherapy of bone metastasis. Although animal experiments show good accumulation of bisphosphonates in bone. The agent has never been tried in humans because of high gamma and beta energy. The agent must first be tested in humans using a relatively safe radioisotope. Technitium-99m (/sup 99m/Tc) a radioisotope with relatively low gamma energy 99m and short half-life can serve as a good label. Whether /sup 99m/Tc-labeled bisphosphonates can be used as good imaging agents is another aspect that needs further investigation. A study was therefore, conducted to label m-trimethyl silylphenyl)-ethylidene-1, 1-bisphosphonate with /sup 99m/Tc and standardize the labeling procedure. The labeling procedure - involved reduction of technetium (TcO/sub 4/) with stannous chloride followed by chelation of technetium with bisphosphonates. Radiochemical purity was checked by paper chromatography. Pyrogenicity was checked by administration of the labeled compound into rabbits. The stability of the compound was determined by noting the radiochemical binding at several intervals of half an hour after preparation. Biodistribution of the agent was studied by injecting the labeled compound into rabbits. The results showed that the compound could be labeled with /sup 99m/Tc without any difficulty. The ease of binding was excellent. There was more than 95% binding of technetium with the compound and the labelled compound was reasonably stable for 5 hours after labeling. The rectal temperature remained stable during this period, which showed that the animal accepted the compound and there were no pyrogenic reactions. Biodistribution studies on rabbit showed that accumulation of agent was poor in bones and the labeled compound remains in blood even after 4

Effect of silibinin-loaded nano-niosomal coated with trimethyl chitosan on miRNAs expression in 2D and 3D models of T47D breast cancer cell line.

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Yazdi Rouholamini, Seyede Elmira; Moghassemi, Saeid; Maharat, Zahra; Hakamivala, Amirhossien; Kashanian, Susan; Omidfar, Kobra

2018-05-01

Silibinin is a natural flavonoid with a strong antioxidant property and weak cytotoxic activity. It has demonstrated anti-tumoural activity against many types of malignancies; however, due to its hydrophobic structure, it has poor water solubility, bioavailability and permeability across intestinal epithelial cells. To improve the effect of silibinin, we have vehiculated silibinin by a highly stable niosomal nanostructure based on a Span 60/cholesterol (CH)/N-trimethyl chitosan (TMC) system in order to study its potential application for the delivery of silibinin in T47D cultured under three-dimensional (3D) and two-dimensional (2D) conditions. To study the effect of nanodrug on miRNAs expression, we evaluated quantitative expression of miRNA-21 and miRNA-15a as well as miR-141 and miR-200c which act as oncogene and tumour suppressors by real-time PCR. Results demonstrated that the mechanism of nanodrug action as well as the response of tumour cells differed in 3D culture as compared to 2D. Delivery of silibinin-loaded niosomes coated with TMC was found to be more effective in inhibiting the growth of tumour cells and inducing apoptosis than free silibinin administration. In silibinin-treated cells, death occurred in a dose- and time- dependent manner by induction of apoptosis and alteration of the cell cycle. Real-time PCR analysis revealed a decrease in miR-21, miR-15a and miR-141while increase in miR-200c expression levels was observed in silibinin-treated cells relative to the levels in the untreated cells. The results show that nanodrug delivery was more effective than free silibinin administration in changing the level of miRNAs expression in cancer cells. Therefore, niosomal nanostructure with TMC could be a suitable vehicle for hydrophobic compounds, such as silibinin, by improving their action in cancer therapy.

Efficiency of radical yield in alkylthymine and alkyluracil by high-LET irradiation

International Nuclear Information System (INIS)

Nakagawa, Seiko; Ohta, Nobuaki; Murakami, Takeshi

2010-01-01

Penthylthymines and hexyl-, nonyl-, and decyl- uracils were irradiated by C-ion (3.5 GeV) and γ-ray at 77 K. ESR spectra were measured to study radiation induced radicals in the temperature range from 108 to 273 K. A dihydro-5-yl (5-yl) radical formed by H addition to C6 carbon and a secondary alkyl radical by C-H bond fission at the second carbon from the end of the alkyl group were produced at 108 K. A dihydrouracil-6-yl (6-yl) radical formed by H addition to C5 carbon increased with increasing temperature for alkyluracils. The spectral feature obtained by C-ion irradiation was coincident with that by γ-irradiation. Total radical yields increased by alkylation and with increasing the length of alkyl chain. Yields of both 5-yl and secondary alkyl radicals irradiated by C-ion were less than those by γ-ray for penthylthymines and hexyluracil. On the contrary, radical yields were almost the same between ion and γ-ray irradiation for nonyl- and decyl-uracil. Mechanism of radical formation and effect of high-LET irradiation were discussed.

Characterization and stability studies of emulsion systems containing pumice

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Marilene Estanqueiro

2014-04-01

Full Text Available Emulsions are the most common form of skin care products. However, these systems may exhibit some instability. Therefore, when developing emulsions for topical application it is interesting to verify whether they have suitable physical and mechanical characteristics and further assess their stability. The aim of this work was to study the stability of emulsion systems, which varied in the proportion of the emulsifying agent cetearyl alcohol (and sodium lauryl sulfate (and sodium cetearyl sulfate (LSX, the nature of the oily phase (decyl oleate, cyclomethicone or dimethicone and the presence or absence of pumice (5% w/w. While maintaining the samples at room temperature, rheology studies, texture analysis and microscopic observation of formulations with and without pumice were performed. Samples were also submitted to an accelerated stability study by centrifugation and to a thermal stress test. Through the testing, it was found that the amount of emulsifying agent affects the consistency and textural properties such as firmness and adhesiveness. So, formulations containing LSX (5% w/w and decyl oleate or dimethicone as oily phase had a better consistency and remained stable with time, so exhibited the best features to be used for skin care products.

Intranasal delivery of Huperzine A to the brain using lactoferrin-conjugated N-trimethylated chitosan surface-modified PLGA nanoparticles for treatment of Alzheimer's disease.

Science.gov (United States)

Meng, Qingqing; Wang, Aiping; Hua, Hongchen; Jiang, Ying; Wang, Yiyun; Mu, Hongjie; Wu, Zimei; Sun, Kaoxiang

2018-01-01

Safe and effective delivery of therapeutic drugs to the brain is important for successful therapy of Alzheimer's disease (AD). To develop Huperzine A (HupA)-loaded, mucoadhesive and targeted polylactide-co-glycoside (PLGA) nanoparticles (NPs) with surface modification by lactoferrin (Lf)-conjugated N-trimethylated chitosan (TMC) (HupA Lf-TMC NPs) for efficient intranasal delivery of HupA to the brain for AD treatment. HupA Lf-TMC NPs were prepared using the emulsion-solvent evaporation method and optimized using the Box-Behnken design. The particle size, zeta potential, drug entrapment efficiency, adhesion and in vitro release behavior were investigated. The cellular uptake was investigated by fluorescence microscopy and flow cytometry. MTT assay was used to evaluate the cytotoxicity of the NPs. In vivo imaging system was used to investigate brain targeting effect of NPs after intranasal administration. The biodistribution of Hup-A NPs after intranasal administration was determined by liquid chromatography-tandem mass spectrometry. Optimized HupA Lf-TMC NPs had a particle size of 153.2±13.7 nm, polydispersity index of 0.229±0.078, zeta potential of +35.6±5.2 mV, drug entrapment efficiency of 73.8%±5.7%, and sustained release in vitro over a 48 h period. Adsorption of mucin onto Lf-TMC NPs was 86.9%±1.8%, which was significantly higher than that onto PLGA NPs (32.1%±2.5%). HupA Lf-TMC NPs showed lower toxicity in the 16HBE cell line compared with HupA solution. Qualitative and quantitative cellular uptake experiments indicated that accumulation of Lf-TMC NPs was higher than nontargeted analogs in 16HBE and SH-SY5Y cells. In vivo imaging results showed that Lf-TMC NPs exhibited a higher fluorescence intensity in the brain and a longer residence time than nontargeted NPs. After intranasal administration, Lf-TMC NPs facilitated the distribution of HupA in the brain, and the values of the drug targeting index in the mouse olfactory bulb, cerebrum (with hippocampus

New synthesis of a stereoisomeric mixture of methyl 12-trishomofarnesoate, a juvenile hormone mimic useful in sericulture by increasing silk production.

Science.gov (United States)

Mori, Kenji

2017-01-01

A mixture of (E,Z)-isomers of methyl 12-trishomofarnesoate (methyl 3,7,11-trimethyl-2,6,10-pentadecatrienoate), a juvenile hormone mimic, was synthesized in nine steps (32.6% overall yield) by starting from only four commercially available materials: 2-hexanone, vinylmagnesium bromide, methyl acetoacetate and trimethyl phosphonoacetate. The mimic is useful in increasing the yield of silk by elongating the larval period of the silkworm, Bombyx mori (L.).

Roles for common MLL/COMPASS subunits and the 19S proteasome in regulating CIITA pIV and MHC class II gene expression and promoter methylation.

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Koues, Olivia I; Mehta, Ninad T; Truax, Agnieszka D; Dudley, R Kyle; Brooks, Jeanne K; Greer, Susanna F

2010-02-04

Studies indicate that the 19S proteasome contributes to chromatin reorganization, independent of the role the proteasome plays in protein degradation. We have previously shown that components of the 19S proteasome are crucial for regulating inducible histone activation events in mammalian cells. The 19S ATPase Sug1 binds to histone-remodeling enzymes, and in the absence of Sug1, a subset of activating epigenetic modifications including histone H3 acetylation, H3 lysine 4 trimethylation and H3 arginine 17 dimethylation are inhibited at cytokine-inducible major histocompatibilty complex (MHC)-II and class II transactivator (CIITA) promoters, implicating Sug1 in events required to initiate mammalian transcription. Our previous studies indicate that H3 lysine 4 trimethylation at cytokine-inducible MHC-II and CIITA promoters is dependent on proteolytic-independent functions of 19S ATPases. In this report, we show that multiple common subunits of the mixed lineage leukemia (MLL)/complex of proteins associated with Set I (COMPASS) complexes bind to the inducible MHC-II and CIITA promoters; that overexpressing a single common MLL/COMPASS subunit significantly enhances promoter activity and MHC-II HLA-DRA expression; and that these common subunits are important for H3 lysine 4 trimethylation at MHC-II and CIITA promoters. In addition, we show that H3 lysine 27 trimethylation, which is inversely correlated with H3 lysine 4 trimethylation, is significantly elevated in the presence of diminished 19S ATPase Sug1. Taken together, these experiments suggest that the 19S proteasome plays a crucial role in the initial reorganization of events enabling the relaxation of the repressive chromatin structure surrounding inducible promoters.

Roles for common MLL/COMPASS subunits and the 19S proteasome in regulating CIITA pIV and MHC class II gene expression and promoter methylation

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Koues Olivia I

2010-02-01

Full Text Available Abstract Background Studies indicate that the 19S proteasome contributes to chromatin reorganization, independent of the role the proteasome plays in protein degradation. We have previously shown that components of the 19S proteasome are crucial for regulating inducible histone activation events in mammalian cells. The 19S ATPase Sug1 binds to histone-remodeling enzymes, and in the absence of Sug1, a subset of activating epigenetic modifications including histone H3 acetylation, H3 lysine 4 trimethylation and H3 arginine 17 dimethylation are inhibited at cytokine-inducible major histocompatibilty complex (MHC-II and class II transactivator (CIITA promoters, implicating Sug1 in events required to initiate mammalian transcription. Results Our previous studies indicate that H3 lysine 4 trimethylation at cytokine-inducible MHC-II and CIITA promoters is dependent on proteolytic-independent functions of 19S ATPases. In this report, we show that multiple common subunits of the mixed lineage leukemia (MLL/complex of proteins associated with Set I (COMPASS complexes bind to the inducible MHC-II and CIITA promoters; that overexpressing a single common MLL/COMPASS subunit significantly enhances promoter activity and MHC-II HLA-DRA expression; and that these common subunits are important for H3 lysine 4 trimethylation at MHC-II and CIITA promoters. In addition, we show that H3 lysine 27 trimethylation, which is inversely correlated with H3 lysine 4 trimethylation, is significantly elevated in the presence of diminished 19S ATPase Sug1. Conclusion Taken together, these experiments suggest that the 19S proteasome plays a crucial role in the initial reorganization of events enabling the relaxation of the repressive chromatin structure surrounding inducible promoters.

Cubane Derivatives for Propellant Applicationsxb

Science.gov (United States)

1989-07-03

cycloperitanone ketal containing 2-3% cyclopentanone and trace amounts of toluene. Approximately 4 liters of purified cyclopentanone ketal per day could be...such as reaction with trimethyl phosphite , also gave inconsistent results. In reactions involving 45 moles of ketal in a 20 gallon Pfaudler reactor...Dioxane treated with trimethyl phosphite Dehydrohalogenation and Dimerization of the Tribromo Ketal to the Bisketal. In-0 0 stop 3 0 Gr r or [to"t

Intranasal delivery of Huperzine A to the brain using lactoferrin-conjugated N-trimethylated chitosan surface-modified PLGA nanoparticles for treatment of Alzheimer’s disease

Science.gov (United States)

Hua, Hongchen; Jiang, Ying; Wang, Yiyun; Mu, Hongjie; Wu, Zimei

2018-01-01

Background Safe and effective delivery of therapeutic drugs to the brain is important for successful therapy of Alzheimer’s disease (AD). Purpose To develop Huperzine A (HupA)-loaded, mucoadhesive and targeted polylactide-co-glycoside (PLGA) nanoparticles (NPs) with surface modification by lactoferrin (Lf)-conjugated N-trimethylated chitosan (TMC) (HupA Lf-TMC NPs) for efficient intranasal delivery of HupA to the brain for AD treatment. Methods HupA Lf-TMC NPs were prepared using the emulsion–solvent evaporation method and optimized using the Box–Behnken design. The particle size, zeta potential, drug entrapment efficiency, adhesion and in vitro release behavior were investigated. The cellular uptake was investigated by fluorescence microscopy and flow cytometry. MTT assay was used to evaluate the cytotoxicity of the NPs. In vivo imaging system was used to investigate brain targeting effect of NPs after intranasal administration. The biodistribution of Hup-A NPs after intranasal administration was determined by liquid chromatography–tandem mass spectrometry. Results Optimized HupA Lf-TMC NPs had a particle size of 153.2±13.7 nm, polydispersity index of 0.229±0.078, zeta potential of +35.6±5.2 mV, drug entrapment efficiency of 73.8%±5.7%, and sustained release in vitro over a 48 h period. Adsorption of mucin onto Lf-TMC NPs was 86.9%±1.8%, which was significantly higher than that onto PLGA NPs (32.1%±2.5%). HupA Lf-TMC NPs showed lower toxicity in the 16HBE cell line compared with HupA solution. Qualitative and quantitative cellular uptake experiments indicated that accumulation of Lf-TMC NPs was higher than nontargeted analogs in 16HBE and SH-SY5Y cells. In vivo imaging results showed that Lf-TMC NPs exhibited a higher fluorescence intensity in the brain and a longer residence time than nontargeted NPs. After intranasal administration, Lf-TMC NPs facilitated the distribution of HupA in the brain, and the values of the drug targeting index in the mouse

EFFECT OF SODIUM PHOSPHATES ON SELECTED FOOD GRADE BACTERIA

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Stanislav Kráčmar

2011-04-01

Full Text Available The aim of this study was to examine the inhibitory effect in vitro of selected sodium phosphates (under the corporate names Hexa 68, Hexa 70, Trikrystal, FST, Pyro 52, KPS, Didi on selected gram-positive and gram-negative bacteria. Seven different concentrations of each phosphate were used. Sensitivity of the bacterial strains to phosphates was observed in broth supplemented with salts. In vitro was showed a negative effect of various phosphates on growth of selected gram-positive bacteria. Orthophosphates and diphosphates (pyrophosphates did not have significant inhibitory effect on tested bacteria at neutral pH. With the exception of phosphate Trikrystal has not been found in vitro significant inhibitory effects on gram-negative bacteria.doi:10.5219/141

Inhibition of mild steel corrosion by 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile and synergistic effect of halide ion in 0.5 M H{sub 2}SO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Mourya, Punita, E-mail: mouryapunita025@gmail.com [Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Singh, Praveen [Department of Chemistry, Banaras Hindu University, Varanasi 221005 (India); Rastogi, R.B.; Singh, M.M. [Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

2016-09-01

Highlights: • TODPCN is a good corrosion inhibitor for mild steel in 0.5 M H{sub 2}SO{sub 4} solution. • Addition of iodide ion increases the inhibition efficiency of the studied nitrile derivative. • Inhibition efficiency successively increases with concentration. • XPS study has revealed the chemical composition of the protective film. - Abstract: The effect of iodide ions on inhibitive performance of 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (TODPCN) on mild steel (MS) corrosion in 0.5 M H{sub 2}SO{sub 4} was studied using gravimetric and electrochemical measurements. TODPCN inhibits the corrosion of MS to the extent of 62.3% at its lowest concentration (0.5 mM) and its inhibition efficiency (η) further increases on increasing concentration at 298 K. The adsorption of TODPCN on MS was found to follow the Langmuir adsorption isotherm. The value of η increased on the addition of 2.0 mM KI. The value of synergism parameter being more than unity indicates that the enhanced η value in the presence of iodide ions is only due to synergism. Thus, a cooperative mechanism of inhibition exists between the iodide anion and TODPCN cations. The increase in surface coverage in the presence of KI indicates that iodide ions enhance the adsorption of TODPCN. The surface morphology of corroded/inhibited MS was studied by atomic force microscopy. X-ray photoelectron spectroscopy of inhibited MS surface was carried out to determine the composition of the adsorbed film. Some quantum chemical parameters and the Mulliken charge densities for TODPCN calculated by density functional theory provided further insight into the mechanism of inhibition.

1-Decyl-6-nitro-1H-benzimidazol-2(3H-one

Directory of Open Access Journals (Sweden)

Younes Ouzidan

2011-11-01

Full Text Available The title molecule, C17H25N3O3, is built up from fused six- and five-membered rings linked to a –C10H21 chain. The fused-ring system is essentially planar, the largest deviation from the mean plane being 0.009 (2 Å. The chain is roughly perpendicular to this plane, making a dihedral angle of 79.5 (2°. In the crystal, N—H...O hydrogen bonds build infinite chains along [010]. There are channels in the structure containing disordered hexane. The contribution of this solvent to the scattering power was suppressed using the SQUEEZE option in PLATON [Spek (2009. Acta Cryst. D65, 148–155].

Immunogenicity and safety of primary and booster vaccination with 2 investigational formulations of diphtheria, tetanus and Haemophilus influenzae type b antigens in a hexavalent DTPa-HBV-IPV/Hib combination vaccine in comparison with the licensed Infanrix hexa

Science.gov (United States)

Vesikari, Timo; Rivera, Luis; Korhonen, Tiina; Ahonen, Anitta; Cheuvart, Brigitte; Hezareh, Marjan; Janssens, Winnie; Mesaros, Narcisa

2017-01-01

ABSTRACT Safety and immunogenicity of 2 investigational formulations of diphtheria, tetanus and Haemophilus influenzae type b antigens of the combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliomyelitis-Hib vaccine (DTPa-HBV-IPV/Hib) were evaluated in a Primary (NCT01248884) and a Booster vaccination (NCT01453998) study. In the Primary study, 721 healthy infants (randomized 1:1:1) received 3 doses of DTPa-HBV-IPV/Hib formulation A (DATAPa-HBV-IPV/Hib), or B (DBTBPa-HBV-IPV/Hib) or the licensed DTPa-HBV-IPV/Hib vaccine (Infanrix hexa, GSK; control group) at 2, 3, 4 months of age. Infants were planned to receive a booster dose at 12–15 months of age with the same formulation received in the Primary study; however, following high incidence of fever associated with the investigational formulations in the Primary study, the Booster study protocol was amended and all infants yet to receive a booster dose (N = 385) received the licensed vaccine. In the Primary study, non-inferiority of 3-dose vaccination with investigational formulations compared with the licensed vaccine was not demonstrated due to anti-pertactin failing to meet the non-inferiority criterion. Post-primary vaccination, most infants had seroprotective levels of anti-diphtheria (100% of infants), anti-tetanus antigens (100%), against hepatitis B (≥ 97.5% across groups), polyribosyl-ribitol-phosphate (≥ 88.0%) and poliovirus types 1–3 (≥ 90.5%). Seropositivity rates for each pertussis antigen were 100% in all groups. Higher incidence of fever (> 38°C) was reported in infants receiving the investigational formulations (Primary study: 75.0% [A] and 72.1% [B] vs 58.8% [control]; Booster study, before amendment: 49.4% and 46.6% vs 37.4%, respectively). The development of the investigational formulations was not further pursued. PMID:28340322

Monosaccharides as Versatile Units for Water-Soluble Supramolecular Polymers.

Science.gov (United States)

Leenders, Christianus M A; Jansen, Gijs; Frissen, Martijn M M; Lafleur, René P M; Voets, Ilja K; Palmans, Anja R A; Meijer, E W

2016-03-18

We introduce monosaccharides as versatile water-soluble units to compatibilise supramolecular polymers based on the benzene-1,3,5-tricarboxamide (BTA) moiety with water. A library of monosaccharide-based BTAs is evaluated, varying the length of the alkyl chain (hexyl, octyl, decyl and dodecyl) separating the BTA and saccharide units, as well as the saccharide units (α-glucose, β-glucose, α-mannose and α-galactose). In all cases, the monosaccharides impart excellent water compatibility. The length of the alkyl chain is the determining factor to obtain either long, one-dimensional supramolecular polymers (dodecyl spacer), small aggregates (decyl spacer) or molecularly dissolved (octyl and hexyl) BTAs in water. For the BTAs comprising a dodecyl spacer, our results suggest that a cooperative self-assembly process is operative and that the introduction of different monosaccharides does not significantly change the self- assembly behaviour. Finally, we investigate the potential of post-assembly functionalisation of the formed supramolecular polymers by taking advantage of dynamic covalent bond formation between the monosaccharides and benzoxaboroles. We observe that the supramolecular polymers readily react with a fluorescent benzoxaborole derivative permitting imaging of these dynamic complexes by confocal fluorescence microscopy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Robotic motion compensation for applications in radiation oncology

Energy Technology Data Exchange (ETDEWEB)

Herrmann, Christian

2013-07-22

Radiation therapy today, on account of improvements in treatment procedures over the last 60 years, allows precise treatment of static tumors inside the human body. However, irradiation of moving tumors is still a challenging task as moving tumors often leave the treatment beam and the radiation dose delivered to the tumor reduces simultaneously increasing that on healthy tissue. This research work aims to push the frontiers of radiation therapy in order to enable precise treatment of moving tumors with focus on research and development of a unique real-time system enabling active motion compensation through robotic means to compensate tumor motion. During treatment, patients lie on a treatment couch which is normally used for static position corrections of patient set-up errors prior to radiation treatment. The treatment couch used, called HexaPOD, is a parallel manipulator with six degrees of freedom which can precisely position heavy loads inside a small region. Despite the HexaPOD not initially built with dynamics in mind, it is used in this work for sustained motion compensation by moving patients such that tumors stay precisely located at the center of the treatment beam during the complete course of treatment. In order to realize real-time tumor motion compensation by means of the HexaPOD, several challenges need to be addressed. Real-time aspects are covered by the adoption of a hard real-time operation system in combination with measurement and estimation of latencies of all physical quantities in the compensation system such as tumor or breathing position measurements. Accurate timing information is respected consistently in the whole system and all software-induced latencies are adaptively compensated for. This requires knowledge of future tumor positions from predictors. Several predictors for breathing and tumor motion predictions are proposed and evaluated in terms of a variety of different performance metrics. Extensions to prediction algorithms are

Robotic motion compensation for applications in radiation oncology

International Nuclear Information System (INIS)

Herrmann, Christian

2013-01-01

Radiation therapy today, on account of improvements in treatment procedures over the last 60 years, allows precise treatment of static tumors inside the human body. However, irradiation of moving tumors is still a challenging task as moving tumors often leave the treatment beam and the radiation dose delivered to the tumor reduces simultaneously increasing that on healthy tissue. This research work aims to push the frontiers of radiation therapy in order to enable precise treatment of moving tumors with focus on research and development of a unique real-time system enabling active motion compensation through robotic means to compensate tumor motion. During treatment, patients lie on a treatment couch which is normally used for static position corrections of patient set-up errors prior to radiation treatment. The treatment couch used, called HexaPOD, is a parallel manipulator with six degrees of freedom which can precisely position heavy loads inside a small region. Despite the HexaPOD not initially built with dynamics in mind, it is used in this work for sustained motion compensation by moving patients such that tumors stay precisely located at the center of the treatment beam during the complete course of treatment. In order to realize real-time tumor motion compensation by means of the HexaPOD, several challenges need to be addressed. Real-time aspects are covered by the adoption of a hard real-time operation system in combination with measurement and estimation of latencies of all physical quantities in the compensation system such as tumor or breathing position measurements. Accurate timing information is respected consistently in the whole system and all software-induced latencies are adaptively compensated for. This requires knowledge of future tumor positions from predictors. Several predictors for breathing and tumor motion predictions are proposed and evaluated in terms of a variety of different performance metrics. Extensions to prediction algorithms are

The Study of the Influence of Urea and Hexa Methylene Tetramine (HMTA) Additive on the Total Gelation Process of Uranium on the Chemical Characteristic of the Poly (Uranate-Vinyl Alcohol) Gel

International Nuclear Information System (INIS)

Damunir

2007-01-01

The study of the influence of urea and Hexa methylene tetramine (HMTA) additive on the total gelation process of uranium on the chemical characteristic of the poly (uranate-vinyl alcohol) gel was done. First of all the 1M uranyl nitrate solution was heated at 70 °C, then variation the 1,2,3,4 and 5M urea additive was studied. Urea was added to the hot solution, and stirred for 10 minutes, producing the colloid particles of UO 3 . The mixing and heating up for 20 minutes, the colloid of UO 3 solution reacted by mixed of THF-PVA 1:1 solution. The solution was cooled at 32°C for 2 hours, and then variation the 1,2,3,4 and 5M HMTA additive was studied. HMTA was added into solution at 32°C and was stirred to form the homogenous sol solution. For the poly (urinate-vinyl) gel formation, the sol solution was dropped to the medium solution of 5M NH 5 OH at ambient condition. Gel formatted was microsphere then soaked, washed by NH 4 OH and hot water to release the chemical matters which were unreacted, was dried at 60°C and then dried at 150°C for 4 hours. The chemical characteristic of gel was made, covering the analyzed of colour, shape and diameter microsphere using optical microscope. Next, the analysis of molecular composition of the gel, using Fourier transform infra red spectroscopic (FTIR), was made. The analytical were the qualitative analysis of the absorption band of infra red spectrum on O-U-O-U-O bond, U-O bond and NH 3 , C-OH, C-H and OH functional group at 300-4000 wave numbers. The result of the research showed that the addition of urea and HMTA additive influences on chemical characteristic of the poly (uranate-vinyl alcohol) gel. The optimum condition was at 2-3 M urea and 2- M HMTA concentration. The analyze of absorption band of infra red spectrum showed that the molecular composition of poly (vinyl alcohol) gel was the uranium trioxide, ammonia, water and polyvinyl alcohol molecular contain with the molecular formulas of [2UO 3 .2 NH 3 .H 2 O

Spontaneous appearance of Tay-Sachs disease in an animal model.

Science.gov (United States)

Zeng, B J; Torres, P A; Viner, T C; Wang, Z H; Raghavan, S S; Alroy, J; Pastores, G M; Kolodny, E H

2008-01-01

Tay-Sachs disease (TSD) is a progressive neurodegenerative disorder due to an autosomal recessively inherited deficiency of beta-hexosaminidase A (Hex A). Deficiency of Hex A in TSD is caused by a defect of the alpha-subunit resulting from mutations of the HEXA gene. To date, there is no effective treatment for TSD. Animal models of genetic diseases, similar to those known to exist in humans, are valuable and essential research tools for the study of potentially effective therapies. However, there is no ideal animal model of TSD available for use in therapeutic trials. In the present study, we report an animal model (American flamingo; Phoenicopterus ruber) of TSD with Hex A deficiency occurring spontaneously in nature, with accumulation of G(M2)-ganglioside, deficiency of Hex A enzymatic activity, and a homozygous P469L mutation in exon 12 of the hexa gene. In addition, we have isolated the full-length cDNA sequence of the flamingo, which consists of 1581 nucleotides encoding a protein of 527 amino acids. Its coding sequence indicates approximately 71% identity at the nucleotide level and about 72.5% identity at the amino acid level with the encoding region of the human HEXA gene. This animal model, with many of the same features as TSD in humans, could represent a valuable resource for investigating therapy of TSD.

Exploratory Development of an Ultra fast-Curing Wound Dressing

Science.gov (United States)

1990-11-30

sterilization of medical devices. The principle advantage of using ionization techniques is that the dressings can be sterilized in hermetically...containing these combinations were no more advantageous than any of the other combinations; and (2) the existing chromatographic methods were not...Chromatography was performed on an AllTech OctaDecyl Silane I (ODS) column (4.6 mm x 250 mm - 5 u) using 1% acetic acid-methanol (60:40) as the mobile phase

Effect of physical exertion on the biological monitoring of exposure to various solvents following exposure by inhalation in human volunteers: II. n-Hexane.

Science.gov (United States)

Tardif, Robert; Nadeau, Véronique; Truchon, Ginette; Brochu, Martin

2007-07-01

This study evaluated the impact of physical exertion on two n-hexane (HEX) exposure indicators in human volunteers exposed under controlled conditions in an inhalation chamber. A group of four volunteers (two women, two men) were exposed to HEX (50 ppm; 176 mg/m(3)) according to several scenarios involving several periods when volunteers performed either aerobic (AERO), muscular (MUSC), or both AERO/MUSC types of exercise. The target intensities for 30-min exercise periods separated by 15-min rest periods were the following: REST, 50W AERO [time-weighted average intensity including resting period (TWAI): 38W], 50W AERO/MUSC (TWAI: 34W), 100W AERO/MUSC (TWAI: 63W), and 100W AERO (TWAI: 71W) for 7 hr (two 3-hr exposure periods separated by 1 hr without exposure) and 50W MUSC for 3 hr (TWAI: 31W). Alveolar air and urine samples were collected at different time intervals before, during, and after exposure to measure unchanged HEX in expired air (HEX-A) and urinary 2,5-hexanedione (2,5-HD). HEX-A levels during exposures involving AERO activities (TWAI: 38W and 71W) were significantly enhanced (approximately +14%) compared with exposure at rest. MUSC or AERO/MUSC exercises were also associated with higher HEX-A levels but only at some sampling times. In contrast, end-of-exposure (7 hr) urinary 2,5-HD (mean +/- SD) was not modified by physical exertion: 4.14 +/- 1.51 micromol/L (REST), 4.02 +/- 1.52 micromol/L (TWAI 34W), 4.25 +/- 1.53 micromol/L (TWAI 38W), 3.73 +/- 2.09 micromol/L (TWAI 63W), 3.6 +/- 1.34 micromol/L (TWAI 71W) even though a downward trend was observed. Overall, this study showed that HEX kinetics is practically insensitive to moderate variations in workload intensity; only HEX-A levels increased slightly, and urinary 2,5-HD levels remained unchanged despite the fact that all types of physical exercise increased the pulmonary ventilation rate.

Immunoprecipitation of Tri-methylated Capped RNA.

Science.gov (United States)

Hayes, Karen E; Barr, Jamie A; Xie, Mingyi; Steitz, Joan A; Martinez, Ivan

2018-02-05

Cellular quiescence (also known as G 0 arrest) is characterized by reduced DNA replication, increased autophagy, and increased expression of cyclin-dependent kinase p27 Kip1 . Quiescence is essential for wound healing, organ regeneration, and preventing neoplasia. Previous findings indicate that microRNAs (miRNAs) play an important role in regulating cellular quiescence. Our recent publication demonstrated the existence of an alternative miRNA biogenesis pathway in primary human foreskin fibroblast (HFF) cells during quiescence. Indeed, we have identified a group of pri-miRNAs (whose mature miRNAs were found induced during quiescence) modified with a 2,2,7-trimethylguanosine (TMG)-cap by the trimethylguanosine synthase 1 (TGS1) protein and transported to the cytoplasm by the Exportin-1 (XPO1) protein. We used an antibody against (TMG)-caps (which does not cross-react with the (m 7 G)-caps that most pri-miRNAs or mRNAs contain [Luhrmann et al ., 1982]) to perform RNA immunoprecipitations from total RNA extracts of proliferating or quiescent HFFs. The novelty of this assay is the specific isolation of pri-miRNAs as well as other non-coding RNAs containing a TMG-cap modification.

Corrosion inhibition performance of imidazolium ionic liquids and their influence on surface ferrous carbonate layer formation

Science.gov (United States)

Yang, Dongrui

Corrosion inhibitors as effective anti-corrosion applications were widely studied and drawn much attention in both academe and industrial area. In this work, a systematic work, including inhibitors selection, anti-corrosion property and characterization, influence on scale formation, testing system design and so on, were reported. The corrosion inhibition performance of four imidazolium ionic liquids in carbon dioxide saturated NaCl solution was investigated by using electrochemical and surface analysis technologies. The four compounds are 1-ethyl-3-methylimidazolium chloride (a), 1-butyl-3-methylimidazolium chloride (b), 1-hexyl-3-methylimidazolium chloride (c), 1-decyl-3-methylimidazolium chloride (d). Under the testing conditions, compound d showed the highest inhibition efficiency and selected as the main object of further study. As a selected representative formula, 1-decyl-3-methylimidazolium chloride was studied in detail about its corrosion inhibition performance on mild steel in carbon dioxide saturated NaCl brine at pH 3.8 and 6.8. Electrochemical and surface analysis techniques were used to characterize the specimen corrosion process during the immersion in the blank and inhibiting solutions. The precorrosion of specimen surface showed significant and different influences on the anti-corrosion property of DMICL at pH 3.8 and 6.8. The corrosion inhibition efficiency (IE) was calculated based on parameters obtained from electrochemical techniques; the achieved IE was higher than 98% at the 25th hour for the steel with a well-polished surface at pH 3.8. The fitting parameters obtained from electrochemical data helped to account for the interfacial changes. As proved in previous research, 1-decyl-3-methylimidazolium chloride could be used as good corrosion inhibitors under certain conditions. However, under other conditions, such chemicals, as well as other species in oil transporting system, could be a factor influencing the evolution of protective surface

Posttranslational Modifications of the Histone 3 Tail and Their Impact on the Activity of Histone Lysine Demethylases In Vitro

DEFF Research Database (Denmark)

Lohse, Brian; Helgstrand, Charlotte; Andersson, Jan Legaard

2013-01-01

mimicking histone H3. Various combinations with other PTMs were employed to study possible cross-talk effects by comparing enzyme kinetic characteristics. We compared the kinetics of histone tail substrates for truncated histone lysine demethylases KDM4A and KDM4C containing only the catalytic core (cc...... toward bis-trimethylated substrates could be observed. Furthermore, a significant difference in the catalytic activity between dimethylated and trimethylated substrates was found for full length demethylases in line with what has been reported previously for truncated demethylases. Histone peptide...

EFFECT OF IMPREGNATION PROCEDURE OF Pt/γ-Al2O3 CATALYSTS UPON CATALYTIC OXIDATION OF CO

Directory of Open Access Journals (Sweden)

Triyono Triyono

2010-06-01

Full Text Available The oxidation of carbon monoxide by oxygen using two catalysts prepared by two different methods has been investigated. In the first method, catalyst prepared by immersing γ-Al2O3 into the hexa-chloroplatinic acid solution at 80oC for 4 h, resulted Pt/γ-Al2O3 catalyst having platinum highly dispersed on the support. While that of immersing γ-Al2O3 in the hexa-chloroplatinic acid solution at room temperature for 12 h, produced Pt/ γ-Al2O3 catalyst where platinum dispersion was much lower. Catalytic activity test showed that platinum well dispersed on the support enhanced the activity of oxidation of carbon monoxide. The platinum impregnated at room temperature resulted in the poor activity.   Keyword: Catalyst, CO Oxidation, Platinum.

Late-onset Tay-Sachs disease: the spectrum of peripheral neuropathy in 30 affected patients.

Science.gov (United States)

Shapiro, Barbara E; Logigian, Eric L; Kolodny, Edwin H; Pastores, Gregory M

2008-08-01

Late-onset Tay-Sachs (LOTS) disease is a chronic, progressive, lysosomal storage disorder caused by a partial deficiency of beta-hexosaminidase A (HEXA) activity. Deficient levels of HEXA result in the intracellular accumulation of GM2-ganglioside, resulting in toxicity to nerve cells. Clinical manifestations primarily involve the central nervous system (CNS) and lower motor neurons, and include ataxia, weakness, spasticity, dysarthria, dysphagia, dystonia, seizures, psychosis, mania, depression, and cognitive decline. The prevalence of peripheral nervous system (PNS) involvement in LOTS has not been well documented, but it has traditionally been thought to be very low. We examined a cohort of 30 patients with LOTS who underwent clinical and electrophysiologic examination, and found evidence of a predominantly axon loss polyneuropathy affecting distal nerve segments in the lower and upper extremities in eight patients (27%).

Insights into Surface Structure and Performance of Fluorinated Silicates from Cohesive Energy Studies

Science.gov (United States)

2016-03-17

inhomogeneity, and texture each affect wetting properties.. As-coated, Ra = 4 nm Annealed 110 °C, 270 min., Ra = 11 nm 8Distribution A: Approved for public...enables potential competition among multiple driving forces during film formation when mixed with PMMA, cast, dried, and subsequently annealed ...mL total solids; 20-50 wt% F-decyl-M2, prepared via pin casting @ 1500 rpm for 30 sec Thermal annealing of films at temperatures of 80-110 C for 30

Adeno-Associated Virus Gene Therapy in a Sheep Model of Tay-Sachs Disease.

Science.gov (United States)

Gray-Edwards, Heather L; Randle, Ashley N; Maitland, Stacy A; Benatti, Hector R; Hubbard, Spencer M; Canning, Peter F; Vogel, Matthew B; Brunson, Brandon L; Hwang, Misako; Ellis, Lauren E; Bradbury, Allison M; Gentry, Atoska S; Taylor, Amanda R; Wooldridge, Anne A; Wilhite, Dewey R; Winter, Randolph L; Whitlock, Brian K; Johnson, Jacob A; Holland, Merilee; Salibi, Nouha; Beyers, Ronald J; Sartin, James L; Denney, Thomas S; Cox, Nancy R; Sena-Esteves, Miguel; Martin, Douglas R

2018-03-01

Tay-Sachs disease (TSD) is a fatal neurodegenerative disorder caused by a deficiency of the enzyme hexosaminidase A (HexA). TSD also occurs in sheep, the only experimental model of TSD that has clinical signs of disease. The natural history of sheep TSD was characterized using serial neurological evaluations, 7 Tesla magnetic resonance imaging, echocardiograms, electrodiagnostics, and cerebrospinal fluid biomarkers. Intracranial gene therapy was also tested using AAVrh8 monocistronic vectors encoding the α-subunit of Hex (TSD α) or a mixture of two vectors encoding both the α and β subunits separately (TSD α + β) injected at high (1.3 × 10 13 vector genomes) or low (4.2 × 10 12 vector genomes) dose. Delay of symptom onset and/or reduction of acquired symptoms were noted in all adeno-associated virus-treated sheep. Postmortem evaluation showed superior HexA and vector genome distribution in the brain of TSD α + β sheep compared to TSD α sheep, but spinal cord distribution was low in all groups. Isozyme analysis showed superior HexA formation after treatment with both vectors (TSD α + β), and ganglioside clearance was most widespread in the TSD α + β high-dose sheep. Microglial activation and proliferation in TSD sheep-most prominent in the cerebrum-were attenuated after gene therapy. This report demonstrates therapeutic efficacy for TSD in the sheep brain, which is on the same order of magnitude as a child's brain.

Comparative study of the interaction of meso-tetrakis (N-para-trimethyl-anilium) porphyrin (TMAP) in its free base and Fe derivative form with oligo(dA.dT)15 and oligo(dG.dC)15.

Science.gov (United States)

Bathaie, S Zahra; Ajloo, Davood; Daraie, Marzieh; Ghadamgahi, Maryam

2015-01-01

Interaction between a cationic porphyrin and its ferric derivative with oligo(dA.dT)15 and oligo(dG.dC)15 was studied by UV-vis spectroscopy, resonance light scattering (RLS), and circular dichroism (CD) at different ionic strengths; molecular docking and molecular dynamics simulation were also used for completion. Followings are the observed changes in the spectral properties of meso-tetrakis (N-para-trimethyl-anilium) porphyrin (TMAP), as a free-base porphyrin with no axial ligand, and its Fe derivative (FeTMAP) upon interaction with oligo(dA.dT)15 and oligo(dG.dC)15: (1) the substantial red shift and hypochromicity at the Soret maximum in the UV-vis spectra; (2) the increased RLS intensity by increasing the ionic strength; and (3) an intense bisignate excitonic CD signal. All of them are the reasons for TMAP and FeTMAP binding to oligo(dA.dT)15 and oligo(dG.dC)15 with the outside binding mode, accompanied by the self-stacking of the ligands along the oligonucleotide helix. The CD results demonstrated a drastic change from excitonic in monomeric behavior at higher ionic strengths, which indicates the groove binding of the ligands with oligonucleotides. Molecular docking also confirmed the groove binding mode of the ligands and estimated the binding constants and energies of the interactions. Their interaction trend was further confirmed by molecular dynamics technique and structure parameters obtained from simulation. It showed that TMAP reduced the number of intermolecular hydrogen bonds and increased the solvent accessible surface area in the oligonucleotide. The self-aggregation of ligands at lower concentrations was also confirmed.

Destabilization of mitochondrial functions as a target against breast cancer progression: Role of TPP+-linked-polyhydroxybenzoates

International Nuclear Information System (INIS)

Sandoval-Acuña, Cristian; Fuentes-Retamal, Sebastián; Guzmán-Rivera, Daniela; Peredo-Silva, Liliana; Madrid-Rojas, Matías; Rebolledo, Solange; Castro-Castillo, Vicente; Pavani, Mario; Catalán, Mabel; Maya, Juan Diego; Jara, José A.; Parra, Eduardo; Calaf, Gloria M.

2016-01-01

Mitochondrion is an accepted molecular target in cancer treatment since it exhibits a higher transmembrane potential in cancer cells, making it susceptible to be targeted by lipophilic-delocalized cations of triphenylphosphonium (TPP + ). Thus, we evaluated five TPP + -linked decyl polyhydroxybenzoates as potential cytotoxic agents in several human breast cancer cell lines that differ in estrogen receptor and HER2/neu expression, and in metabolic profile. Results showed that all cell lines tested were sensitive to the cytotoxic action of these compounds. The mechanism underlying the cytotoxicity would be triggered by their weak uncoupling effect on the oxidative phosphorylation system, while having a wider and safer therapeutic range than other uncouplers and a significant lowering in transmembrane potential. Noteworthy, while the TPP + -derivatives alone led to almost negligible losses of ATP, when these were added in the presence of an AMP-activated protein kinase inhibitor, the levels of ATP fell greatly. Overall, data presented suggest that decyl polyhydroxybenzoates-TPP + and its derivatives warrant future investigation as potential anti-tumor agents. - Highlights: • TPP + -polyhydroxybenzoates are cytotoxic to various subtypes of breast cancer cells. • Cytotoxicity is not-dependent on the expression of estrogen/growth factor receptors. • Cytotoxicity appears to be triggered by a weak mitochondrial uncoupling effect. • Effects include loss of transmembrane potential and apoptosis was detected. • TPP + -polyhydroxybenzoates inhibit migration of highly metastatic cells.

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

Energy Technology Data Exchange (ETDEWEB)

Naejus, R.; Coudert, R.; Lemordant, D. [Laboratoire P.I.M.I.R. EA, Sciences et Techniques, 37 - Tours (France); Willmann, P. [CNES, 31 - Toulouse (France)

1996-12-31

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.

Novel method to prepare multiwalled carbon nanotube/poly(dimethyl siloxane) (MWCNT/PDMS) non-conducting composites

DEFF Research Database (Denmark)

Goswami, Kaustav; Daugaard, Anders Egede; Skov, Anne Ladegaard

In this study a new method of carbon nanotube (CNT) incorporation was employed for the preparation of ultraviolet (UV) curable CNT filled poly (dimethyl siloxane) (PDMS) composites. The composites were designed to contain loadings of CNT above the percolation threshold without becoming conductive...... due to a localized distribution of CNT. Ultrasonicated and dispersed multiwalled CNTs were mixed with short chain ,- vinyl terminated PDMS. When the whole mixture containing dispersed CNT and short chain PDMS was irradiated with UV radiation in presence of deficient amount of hexa functional thiol...... PDMS crosslinker and a photoinitiator, hyperbranced PDMS layer was formed over the CNTs. The prepared hyperbranched CNTs were mixed in different weight ratios (0.33%, 0.66%, 1%) with long chain ,- vinyl terminated PDMS and crosslinked subsequently with the same hexa functional thiol PDMS via UV...

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

Energy Technology Data Exchange (ETDEWEB)

Naejus, R; Coudert, R; Lemordant, D [Laboratoire P.I.M.I.R. EA, Sciences et Techniques, 37 - Tours (France); Willmann, P [CNES, 31 - Toulouse (France)

1997-12-31

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.

Structure of zone-cast HBC-C12H25 films

DEFF Research Database (Denmark)

Breiby, Dag Werner; Bunk, Oliver; Pisula, W.

2005-01-01

The structure of a thin zone-cast film of the hexa-n-dodecyl-substituted hexa-peri-benzocoronene (HBC) has been investigated using grazing incidence X-ray diffraction. A model with an orthorhombic unit cell containing two molecules accounts well for the observations. The molecules are arranged...... in a "herringbone" structure resembling the packing observed for unsubstituted HBC. The molecular disk planes are oriented perpendicularly to the substrate, rotated by approximately 39 degrees about the film normal. The relatively long side chains of dodecyl were found to be in an ordered interdigitated state....... The aliphatic side chains and the aromatic HBC-cores segregate to form regular vertical domains spanning the film thickness. For in-plane rocking scans a discrete orientation distribution is observed with peaks at regular angle intervals. We interpret this as a grain boundary effect induced by alkyl chain...

Identification and Characterization of a Novel Human Methyltransferase Modulating Hsp70 Protein Function through Lysine Methylation*

Science.gov (United States)

Jakobsson, Magnus E.; Moen, Anders; Bousset, Luc; Egge-Jacobsen, Wolfgang; Kernstock, Stefan; Melki, Ronald; Falnes, Pål Ø.

2013-01-01

Hsp70 proteins constitute an evolutionarily conserved protein family of ATP-dependent molecular chaperones involved in a wide range of biological processes. Mammalian Hsp70 proteins are subject to various post-translational modifications, including methylation, but for most of these, a functional role has not been attributed. In this study, we identified the methyltransferase METTL21A as the enzyme responsible for trimethylation of a conserved lysine residue found in several human Hsp70 (HSPA) proteins. This enzyme, denoted by us as HSPA lysine (K) methyltransferase (HSPA-KMT), was found to catalyze trimethylation of various Hsp70 family members both in vitro and in vivo, and the reaction was stimulated by ATP. Furthermore, we show that HSPA-KMT exclusively methylates 70-kDa proteins in mammalian protein extracts, demonstrating that it is a highly specific enzyme. Finally, we show that trimethylation of HSPA8 (Hsc70) has functional consequences, as it alters the affinity of the chaperone for both the monomeric and fibrillar forms of the Parkinson disease-associated protein α-synuclein. PMID:23921388

A Brillouin scattering study of the effect of chemical passivation on the elastic properties of porous silicon

Science.gov (United States)

Fan, H. J.; Kuok, M. H.; Ng, S. C.; Boukherroub, R.; Lockwood, D. J.

2002-07-01

Brillouin scattering has been performed to probe acoustic waves in porous silicon films that have been chemically modified with either 1-decene, decyl aldehyde, undecylenic acid, or ethyl undecylenate. The shift in the frequencies of acoustic modes in the passivated porous silicon samples, relative to those in freshly prepared porous silicon, is different for different chemical modifiers. The magnitude of the frequency shift is qualitatively correlated with the change, caused by the passivation, in the average densities and elastic constants of the samples.

Complex epigenetic regulation of engrailed-2 (EN-2) homeobox gene in the autism cerebellum.

Science.gov (United States)

James, S J; Shpyleva, Svitlana; Melnyk, Stepan; Pavliv, Oleksandra; Pogribny, I P

2013-02-19

The elucidation of epigenetic alterations in the autism brain has potential to provide new insights into the molecular mechanisms underlying abnormal gene expression in this disorder. Given strong evidence that engrailed-2 (EN-2) is a developmentally expressed gene relevant to cerebellar abnormalities and autism, the epigenetic evaluation of this candidate gene was undertaken in 26 case and control post-mortem cerebellar samples. Assessments included global DNA methylation, EN-2 promoter methylation, EN-2 gene expression and EN-2 protein levels. Chromatin immunoprecipitation was used to evaluate trimethylation status of histone H3 lysine 27 (H3K27) associated with gene downregulation and histone H3 lysine 4 (H3K4) associated with gene activation. The results revealed an unusual pattern of global and EN-2 promoter region DNA hypermethylation accompanied by significant increases in EN-2 gene expression and protein levels. Consistent with EN-2 overexpression, histone H3K27 trimethylation mark in the EN-2 promoter was significantly decreased in the autism samples relative to matched controls. Supporting a link between reduced histone H3K27 trimethylation and increased EN-2 gene expression, the mean level of histone H3K4 trimethylation was elevated in the autism cerebellar samples. Together, these results suggest that the normal EN-2 downregulation that signals Purkinje cell maturation during late prenatal and early-postnatal development may not have occurred in some individuals with autism and that the postnatal persistence of EN-2 overexpression may contribute to autism cerebellar abnormalities.

Tocopherol metabolites 2, 5, 7, 8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC) and 2, 7, 8-trimethyl-2-(2'-carboxyethyl)-6-hydroxychroman (gamma-CEHC) in human serum after a single dose of natural vitamin E.

Science.gov (United States)

Radosavac, Dragan; Graf, Peter; Polidori, M Cristina; Sies, Helmut; Stahl, Wilhelm

2002-06-01

alpha- and gamma-Tocopherol are vitamin E compounds in human blood and tissues. alpha-CEHC (2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman) and gamma-CEHC (2,7,8-trimethyl-2-(2'-carboxyethyl)-6-hydroxychroman) have been identified as water-soluble metabolites which are excreted with the urine in humans. To assess over-time changes of serum levels of alpha- and gamma-CEHC in humans after a single dose of vitamin E from a natural source. Twenty-one healthy subjects ingested a single dose of vitamin E (306 mg of RRR-alpha-tocopherol and 1.77 mg of gamma-tocopherol). Blood was collected before (baseline) and 2, 6, 12, 24, 35, 50, and 74 h after ingestion. Serum was separated and levels of alpha- and gamma-tocopherol and alpha- and gamma-CEHC were determined by HPLC. After vitamin E ingestion, a statistically significant increase was observed for alpha-tocopherol and alpha-CEHC. Maximum serum levels for both compounds were measured 12 h after application (33.3 +/- 11.1 micromol alpha-toco-pherol /L and 42.4 +/- 18.3 nmol alpha-CEHC /L); baseline values were reached again after 72 h. While gamma-tocopherol levels decreased during the study period, an increase in the metabolite gamma-CEHC was observed. The optical isomer formed in the metabolism of RRR-alpha-tocopherol was assigned as S-alpha-CEHC. alpha-CEHC levels increase after administration of a single dose of natural vitamin E in humans. The appearance of the metabolite in blood parallels that of the parent compound. The gamma-tocopherol analog appears to be metabolized more efficiently than alpha-tocopherol.

Distribution characteristics of polychlorinated biphenyls (PCBs) in coastal areas of Okinawa Island, Japan

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Surface sediment and seawater samples were collected from coastal areas around Okinawa Island from September 2001 to May 2002. The samples were analyzed for total polychlorinated biphenyl (PCB) levels and homolog composition. The results show that total PCB levels ranged from 0.32 to 128.7 ng/g (dry wt.) in sediment and 1.59 to 2.48 ng/L in seawater. The levels exceed the Environmental Quality Standard (EQS) for water pollution of Japan. The distribution of PCB homolog showed different patterns in the sediments and seawaters. Penta-chlorobiphenyls (CBs) comprised the main congener group in seawater, while hexa-CBs were more abundant homologs in the sediments. The heavily contaminated sites featured higher CBs, including penta-CBs, hexa-CBs, and hepta-CBs, than those in less contaminated sites where tri-CBs dominated. This study provides current distribution and geochemical behavior of PCBs in the coastal areas around Okinawa Island.

PCB138, but not PCB153 and PCB180, acts as a weak antiandrogen in vitro

DEFF Research Database (Denmark)

Vinggaard, A.M.; Bonefeld-Jørgensen, Eva Cecilie

2000-01-01

The polychlorinated biphenyls (PCBs) constitute a group of persistent environmental chemicals including 209 possible congeners exhibiting a variety of chlorine substitution patterns. Due to their lipophilic nature and resistance toward biotransformation, PCBs accumulate in the food chain and all...... environmental matrixes including human adipose tissue, blood and milk. In most biological extracts PCB#138 (2,2',3,4,4',5-hexaCB), PCB#153 (2,2',4,4',5,5'-hexaCB), and PCB#180 (2,2',3,4,4',5,5'-heptaCB) are the dominating components. Depending on the position and number of chlorine substitutions, different...... classes of PCB congeners elicit a complex spectrum of biological and toxic responses in in vivo and in vitro models. Some PCBs exert dioxin-like activities mediated through the aryl hydrocarbon receptor (Ah receptor) giving rise to health risk such as organ toxicity and carcinogenesis. Although reports...

Fusion of Nonionic Vesicles

DEFF Research Database (Denmark)

Bulut, Sanja; Oskolkova, M. Z.; Schweins, R.

2010-01-01

We present an experimental study of vesicle fusion using light and neutron scattering to monitor fusion events. Vesicles are reproducibly formed with an extrusion procedure using an single amphiphile triethylene glycol mono-n-decyl ether in water. They show long-term stability for temperatures ar...... a barrier to fusion changing from 15 k(B)T at T = 26 degrees C to 10k(H) T at T = 35 degrees C. These results are compatible with the theoretical predictions using the stalk model of vesicle fusion....

Structure of sodium alkyl sulphate micelles

International Nuclear Information System (INIS)

Vass, Sz.

1990-05-01

Micellar aggregation numbers of aggregated sodium octyl, decyl, dodecyl and tetradecyl sulphate molecules obtained from small-angle neutron scattering (SANS) measurements are reported. The surfactant concentration and solution temperature were varied systematically. A survey of the physical models and evaluation algorithms applied for SANS are presented. By utilizing a new least square fitting algorithm, the formation and annihilation parameters of orthopositronium in the micellar pseudophase and in the aqueous solvent is deduced by evaluating positron lifetime spectra measured by conventional technqiues. (R.P.) 157 refs.; 10 figs

Real-world problem-based learning: a case study evaluated | de ...

African Journals Online (AJOL)

The Hexa-C Metamodel is used as inquiry tool to evaluate the student project according to contemporary learning and instructional theories, using the criteria of Creativity, Collaborative learning, Customization, Components, Cognitive learning, and Constructivism. Background to the particular course is provided followed by ...

Immunogenicity of meningococcal PorA antigens in OMV vaccines

NARCIS (Netherlands)

Luijkx, T.A.

2006-01-01

For the prevention of meningococcal infection caused by group B meningococci, the Netherlands Vaccine Institute (NVI) has developed a hexavalent Porin A (PorA) based Outer Membrane Vesicle (OMV) vaccine (Hexamen). In various clinical studies with HexaMen, differences in the immune responses to the

Effects of nickel, chromate, and arsenite on histone 3 lysine methylation

International Nuclear Information System (INIS)

Zhou Xue; Li Qin; Arita, Adriana; Sun Hong; Costa, Max

2009-01-01

Occupational exposure to nickel (Ni), chromium (Cr), and arsenic (As) containing compounds has been associated with lung cancer and other adverse health effects. Their carcinogenic properties may be attributable in part, to activation and/or repression of gene expression induced by changes in the DNA methylation status and histone tail post-translational modifications. Here we show that individual treatment with nickel, chromate, and arsenite all affect the gene activating mark H3K4 methylation. We found that nickel (1 mM), chromate (10 μM), and arsenite (1 μM) significantly increase tri-methyl H3K4 after 24 h exposure in human lung carcinoma A549 cells. Seven days of exposure to lower levels of nickel (50 and 100 μM), chromate (0.5 and 1 μM) or arsenite (0.1, 0.5 and 1 μM) also increased tri-methylated H3K4 in A549 cells. This mark still remained elevated and inherited through cell division 7 days following removal of 1 μM arsenite. We also demonstrate by dual staining immunofluorescence microscopy that both H3K4 tri-methyl and H3K9 di-methyl marks increase globally after 24 h exposure to each metal treatment in A549 cells. However, the tri-methyl H3K4 and di-methyl H3K9 marks localize in different regions in the nucleus of the cell. Thus, our study provides further evidence that a mechanism(s) of carcinogenicity of nickel, chromate, and arsenite metal compounds may involve alterations of various histone tail modifications that may in turn affect the expression of genes that may cause transformation

Biodegradation of gasoline in environment: from total assessment to the case of recalcitrant hydrocarbons; Biodegradabilite de l'essence dans l'environnement: de l'evaluation globale au cas des hydrocarbures recalcitrants

Energy Technology Data Exchange (ETDEWEB)

Solano-Serena, F.

1999-11-26

Because of their massive utilisation, hydrocarbons are major pollutants of soils and aquifers. Biodegradation is a key aspect of the fate of pollutants in the environment. Such knowledge, concerns in particular the intrinsic biodegradability of the products and the distribution in the environment of competent degradative microflora. In this study, a methodology has been developed to assess the aerobic biodegradability of gasoline. It is based on the direct gas chromatographic analysis of all hydrocarbons, after incubation in optimal conditions, of gasoline fractions and of model mixtures. The results demonstrated first the quasi-total biodegradability of gasoline ({>=} 94%). Concerning the distribution in the environment of degradative capacities, even microflora from non polluted sites exhibited a high performance (total degradation rates at least 85%) but were limited concerning the degradation of trimethyl-alkanes, such as 2,2,4-trimethyl-pentane (iso-octane) and 2,3,4-trimethyl-pentane, and of cyclohexane. Samples of polluted sites exhibited more extensive degradative capacities with total degradation in half of the cases studied. Cyclohexane was always degraded by mutualism and/or co-metabolism. Trimethyl-alkanes with quaternary carbons such as iso-octane and/or alkyl groups on consecutive carbons were degraded by co-metabolism but could also support growth of specialized strains. A strain of Mycobacterium austroafricanum (strain IFP 2173) growing on iso-octane was isolated from a gasoline polluted sample. This strain exhibited the capacity to co-metabolize various hydrocarbons (cyclic and branched alkanes, aromatics) and in particular cyclohexane. M austroafricanum lFP 2173 was also able to use a large spectrum of hydrocarbons (n- and iso-alkanes, aromatics) as sole carbon and energy source. (author)

Human METTL20 methylates lysine residues adjacent to the recognition loop of the electron transfer flavoprotein in mitochondria.

Science.gov (United States)

Rhein, Virginie F; Carroll, Joe; He, Jiuya; Ding, Shujing; Fearnley, Ian M; Walker, John E

2014-08-29

In mammalian mitochondria, protein methylation is a relatively uncommon post-transcriptional modification, and the extent of the mitochondrial protein methylome, the modifying methyltransferases, and their substrates have been little studied. As shown here, the β-subunit of the electron transfer flavoprotein (ETF) is one such methylated protein. The ETF is a heterodimer of α- and β-subunits. Lysine residues 199 and 202 of mature ETFβ are almost completely trimethylated in bovine heart mitochondria, whereas ETFα is not methylated. The enzyme responsible for the modifications was identified as methyltransferase-like protein 20 (METTL20). In human 143B cells, the methylation of ETFβ is less extensive and is diminished further by suppression of METTL20. Tagged METTL20 expressed in HEK293T cells specifically associates with the ETF and promotes the trimethylation of ETFβ lysine residues 199 and 202. ETF serves as a mobile electron carrier linking dehydrogenases involved in fatty acid oxidation and one-carbon metabolism to the membrane-associated ubiquinone pool. The methylated residues in ETFβ are immediately adjacent to a protein loop that recognizes and binds to the dehydrogenases. Suppression of trimethylation of ETFβ in mouse C2C12 cells oxidizing palmitate as an energy source reduced the consumption of oxygen by the cells. These experiments suggest that the oxidation of fatty acids in mitochondria and the passage of electrons via the ETF may be controlled by modulating the protein-protein interactions between the reduced dehydrogenases and the β-subunit of the ETF by trimethylation of lysine residues. METTL20 is the first lysine methyltransferase to be found to be associated with mitochondria. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Synthesis and Utilization of Trialkylammonium-Substituted Cyclodextrins as Water-Soluble Chiral NMR Solvating Agents for Anionic Compounds.

Science.gov (United States)

Dowey, Alison E; Puentes, Cira Mollings; Carey-Hatch, Mira; Sandridge, Keyana L; Krishna, Nikhil B; Wenzel, Thomas J

2016-04-01

Cationic trialkylammonium-substituted α-, β-, and γ-cyclodextrins containing trimethyl-, triethyl-, and tri-n-propylammonium substituent groups were synthesized and analyzed for utility as water-soluble chiral nuclear magnetic resonance (NMR) solvating agents. Racemic and enantiomerically pure (3-chloro-2-hydroxypropyl)trimethyl-, triethyl-, and tri-n-propyl ammonium chloride were synthesized from the corresponding trialkyl amine hydrochloride and either racemic or enantiomerically pure epichlorohydrin. The ammonium salts were then reacted with α-, β-, and γ-cyclodextrins at basic pH to provide the corresponding randomly substituted cationic cyclodextrins. The (1) H NMR spectra of a range of anionic, aromatic compounds was recorded with the cationic cyclodextrins. Cyclodextrins with a single stereochemistry at the hydroxy group on the (2-hydroxypropyl)trialkylammonium chloride substituent were often but not always more effective than the corresponding cyclodextrin in which the C-2 position was racemic. In several cases, the larger triethyl or tri-n-propyl derivatives were more effective than the corresponding trimethyl derivative at causing enantiomeric differentiation. None of the cyclodextrin derivatives were consistently the most effective for all of the anionic compounds studied. © 2016 Wiley Periodicals, Inc.

Degradation of exogenous caffeine by Populus alba and its effects on endogenous caffeine metabolism.

Science.gov (United States)

Pierattini, Erika C; Francini, Alessandra; Raffaelli, Andrea; Sebastiani, Luca

2016-04-01

This is the first study reporting the presence of endogenous caffeine, theobromine, and theophylline in all organs of poplar plants. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used in order to evaluate the uptake, translocation, and metabolism of caffeine-(trimethyl-(13)C) in Populus alba L. Villafranca clone grown in hydroponic conditions. We investigated the remediation of caffeine since it is one of the most widely consumed drugs and it is frequently detected in wastewater treatment plant effluents, surface water, and groundwater worldwide. Our results demonstrated that poplar can absorb and degrade exogenous caffeine without negative effects on plant health. Data showed that concentrations of all endogenous compounds varied depending on caffeine-(trimethyl-(13)C) treatments. In particular, in control conditions, endogenous caffeine, theobromine, and theophylline were mainly distributed in roots. On the other hand, once caffeine-(trimethyl-(13)C) was provided, this compound and its dimethy-(13)C metabolites are mainly localized at leaf level. In conclusion, our results support the possible use of Villafranca clone in association with other water treatment systems in order to complete the process of caffeine remediation.

Abscisic acid-type sesquiterpenes and ansamycins from Amycolatopsis alba DSM 44262.

Science.gov (United States)

Li, Xiao-Mei; Li, Xiao-Man; Lu, Chun-Hua

2017-10-01

Two new abscisic acid-type sesquiterpenes (1, 2), and one new ansamycin (3), together with four known ansamycins, namely ansacarbamitocins 4-7, were isolated from the fermentation extract of Amycolatopsis alba DSM 44262. The structures of the new compounds were elucidated to be (E)-3-methyl-5-(2,6,6-trimethyl-3-oxocyclohex-1-enyl)pent-2-enoic acid (1) and (E)-3-methyl-5-(2,6,6-trimethyl-4-oxocyclohex-2-enyl)pent-2-enoic acid (2), and 9-O-methylansacarbamitocin A1 (3), on the basis of comprehensive analysis of spectroscopic data, respectively. The antimicrobial activities were also evaluated for all seven compounds.

Destabilization of mitochondrial functions as a target against breast cancer progression: Role of TPP{sup +}-linked-polyhydroxybenzoates

Energy Technology Data Exchange (ETDEWEB)

Sandoval-Acuña, Cristian [Clinical and Molecular Pharmacology Program, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Av. Independencia 1027, Santiago 8380453 (Chile); Laboratory of Antioxidants, Nutrition and Food Technology Institute, University of Chile, El Líbano 5524, Santiago 7830490 (Chile); Fuentes-Retamal, Sebastián; Guzmán-Rivera, Daniela; Peredo-Silva, Liliana [Clinical and Molecular Pharmacology Program, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Av. Independencia 1027, Santiago 8380453 (Chile); Madrid-Rojas, Matías; Rebolledo, Solange [Department of Chemistry, Faculty of Basic Sciences, Metropolitan Educational Sciences University, Av. José Pedro Alessandri 774, Santiago 7760197 (Chile); Castro-Castillo, Vicente [Department of Organic and Physical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santos Dumont 964, Santiago 8380494 (Chile); Pavani, Mario; Catalán, Mabel; Maya, Juan Diego [Clinical and Molecular Pharmacology Program, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Av. Independencia 1027, Santiago 8380453 (Chile); Jara, José A. [Unit of Pharmacology and Pharmacogenetics, Institute of Dental Sciences Research (ICOD), Faculty of Dentistry, University of Chile, Sergio Livingstone Polhammer 94, Santiago 8380492 (Chile); Parra, Eduardo [School of Medicine, Faculty of Health Sciences, University of Tarapacá, Av. General Velásquez 1775, Arica 1000007 (Chile); Calaf, Gloria M. [Institute for Advanced Research, University of Tarapacá, Antofagasta 1520, Arica 1001236 (Chile); and others

2016-10-15

Mitochondrion is an accepted molecular target in cancer treatment since it exhibits a higher transmembrane potential in cancer cells, making it susceptible to be targeted by lipophilic-delocalized cations of triphenylphosphonium (TPP{sup +}). Thus, we evaluated five TPP{sup +}-linked decyl polyhydroxybenzoates as potential cytotoxic agents in several human breast cancer cell lines that differ in estrogen receptor and HER2/neu expression, and in metabolic profile. Results showed that all cell lines tested were sensitive to the cytotoxic action of these compounds. The mechanism underlying the cytotoxicity would be triggered by their weak uncoupling effect on the oxidative phosphorylation system, while having a wider and safer therapeutic range than other uncouplers and a significant lowering in transmembrane potential. Noteworthy, while the TPP{sup +}-derivatives alone led to almost negligible losses of ATP, when these were added in the presence of an AMP-activated protein kinase inhibitor, the levels of ATP fell greatly. Overall, data presented suggest that decyl polyhydroxybenzoates-TPP{sup +} and its derivatives warrant future investigation as potential anti-tumor agents. - Highlights: • TPP{sup +}-polyhydroxybenzoates are cytotoxic to various subtypes of breast cancer cells. • Cytotoxicity is not-dependent on the expression of estrogen/growth factor receptors. • Cytotoxicity appears to be triggered by a weak mitochondrial uncoupling effect. • Effects include loss of transmembrane potential and apoptosis was detected. • TPP{sup +}-polyhydroxybenzoates inhibit migration of highly metastatic cells.

TETRACHLORO ZINCATE (II) [H2pymo][ZnCl4

African Journals Online (AJOL)

assembly of a hexa-palladium bowl-shaped cluster, ... mimic the properties of conventional porous solids. A number of ... mg (2 mmol) of [H2pymo]Cl were ground ... Figure 2: The anion environment in the structure of [H2pymo]2[ZnCl4]. Figure ...

Lipopolysaccharides with acylation defects potentiate TLR4 signaling and shape T cell responses.

Directory of Open Access Journals (Sweden)

Anna Martirosyan

Full Text Available Lipopolysaccharides or endotoxins are components of Gram-negative enterobacteria that cause septic shock in mammals. However, a LPS carrying hexa-acyl lipid A moieties is highly endotoxic compared to a tetra-acyl LPS and the latter has been considered as an antagonist of hexa-acyl LPS-mediated TLR4 signaling. We investigated the relationship between the structure and the function of bacterial LPS in the context of human and mouse dendritic cell activation. Strikingly, LPS with acylation defects were capable of triggering a strong and early TLR4-dependent DC activation, which in turn led to the activation of the proteasome machinery dampening the pro-inflammatory cytokine secretion. Upon activation with tetra-acyl LPS both mouse and human dendritic cells triggered CD4(+ T and CD8(+ T cell responses and, importantly, human myeloid dendritic cells favored the induction of regulatory T cells. Altogether, our data suggest that LPS acylation controlled by pathogenic bacteria might be an important strategy to subvert adaptive immunity.

Mushroom body glycolysis is required for olfactory memory in Drosophila.

Science.gov (United States)

Wu, Chia-Lin; Chang, Ching-Ching; Wu, Jie-Kai; Chiang, Meng-Hsuan; Yang, Chu-Huai; Chiang, Hsueh-Cheng

2018-04-01

Glucose catabolism, also known as glycolysis, is important for energy generation and involves a sequence of enzymatic reactions that convert a glucose molecule into two pyruvate molecules. The glycolysis process generates adenosine triphosphate as a byproduct. In this study, we investigated whether glycolysis plays a role in maintaining neuronal functions in the Drosophila mushroom bodies (MBs), which are generally accepted to be an olfactory learning and memory center. Our data showed that individual knockdown of glycolytic enzymes in the MBs, including hexokinase (HexA), phosphofructokinase (Pfk), or pyruvate kinase (PyK), disrupts olfactory memory. Whole-mount brain immunostaining indicated that pyruvate kinase is strongly expressed in the MB αβ, α'β', and γ neuron subsets. We conclude that HexA, Pfk, and PyK are required in each MB neuron subset for olfactory memory formation. Our data therefore indicates that glucose catabolism in the MBs is important for olfactory memory formation in Drosophila. Copyright © 2018 Elsevier Inc. All rights reserved.

Phthalates in toys available in Indian market.

Science.gov (United States)

Johnson, Sapna; Saikia, Nirmali; Sahu, Ramakant

2011-06-01

Twenty four children's toys and child care articles available in the local market of India were analyzed for eight phthalates as children toys are plasticized with phthalates. All toy samples showed the presence of one or more phthalates including di-(2-ethylhexyl) phthalate (96% of the samples), di-iso-nonyl phthalate and di-iso-decyl phthalate (42% of the samples) at a concentration ranging from 0.1% to 16.2%. Soft toys contain higher levels of phthalates as compared to hard toys as primary function of phthalates is softening of hard plastic materiel.

New insights into the acid mediated disproportionation of pentavalent uranyl

Energy Technology Data Exchange (ETDEWEB)

Mougel, Victor; Biswas, Biplab; Pecaut, Jacques; Mazzanti, Marinella [Laboratoire de Reconnaissance Ionique et Chimie de Coordination, SCIB, UMR-E 3 CEA-UJF FRE 3200 CNRS, INAC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 09 (France)

2010-07-01

The reaction of benzoic acid with the uranyl(V) complex [(UO{sub 2}Py{sub 5})(KI{sub 2}Py{sub 2})] in pyridine leads to immediate disproportionation with formation of a hexa-nuclear U(IV) benzoate cluster, a bis-benzoate complex of uranyl(VI) and water. (authors)

Cross-reactivity of antibodies against PorA after vaccination with a meningococcal B outer membrane vesicle vaccine

NARCIS (Netherlands)

Vermont, C. L.; van Dijken, H. H.; Kuipers, A. J.; van Limpt, C. J. P.; Keijzers, W. C. M.; van der Ende, A.; de Groot, R.; van Alphen, L.; van den Dobbelsteen, G. P. J. M.

2003-01-01

The cross-reactivity of PorA-specific antibodies induced by a monovalent P1.7-2,4 (MonoMen) and/or a hexavalent (HexaMen) meningococcal B outer membrane vesicle vaccine (OMV) in toddlers and school children was studied by serum bactericidal assays (SBA). First, isogenic vaccine strains and

Column study of enhanced Cr(VI) removal and longevity by coupled abiotic and biotic processes using Fe⁰ and mixed anaerobic culture

DEFF Research Database (Denmark)

Zhong, Jiawei; Yin, Weizhao; Li, Yongtao

2017-01-01

In this study, Fe(0) and mixed anaerobic culture were integrated in one column to investigate the coupled abiotic and biotic effects on hexa-valent chromium (Cr(VI)) removal and column longevity with an abiotic Fe(0) column in the control experiments. According to the breakthrough study, a slower...

Aging as Evolution-Facilitating Program and a Biochemical Approach to Switch It Off

Science.gov (United States)

Skulachev, Vladimir P.

A concept is presented considering aging of living organisms as a final step of their ontogenetic program. It is assumed that such an aging program was invented by biological evolution to facilitate the evolutionary process. Indications are summarized suggesting that controlled production of toxic forms of oxygen (so called reactive oxygen species) by respiring intracellular organelles (mitochondria) is an obligatory component of the aging program. First results of a research project devoted to an attempt to interrupt aging program by antioxidants specifically addressed to mitochondria have been described. Within the framework of the project, antioxidants of a new type (SkQ) were synthesized. SkQs are composed of (i) plastoquinone (an antioxidant moiety), (ii) a penetrating cation, and (iii) a decane or pentane linker. Using planar bilayer phospholipid membranes, we selected SkQ derivatives of the highest penetrability, namely plastoquinonyl decyl triphenylphosphonium (SkQ1), plastoquinonyl decyl rhodamine 19 (SkQR1), and methylplastoquinonyl decyl triphenylphosphonium (SkQ3). Anti- and prooxidant properties of these substances and also of ubiquinonyl-decyl-triphenylphosphonium (MitoQ) were tested in isolated mitochondria. Micromolar concentrations of cationic quinones are found to be very strong prooxidants, but in the lower (sub-micromolar) concentrations they display antioxidant activity which decreases in the series SkQ1 = SkQR1 > SkQ3 > MitoQ. Thus, the window between the anti- and prooxidant effects is the smallest for MitoQ and the largest for SkQ1 and SkQR1. SkQ1 is rapidly reduced by complex III of the mitochondrial respiratory chain, i.e. it is a rechargeable antioxidant. Extremely low concentrations of SkQ1 and SkQR1 completely arrest the H2O2-induced apoptosis in human fibroblasts and HeLa cells (for SkQ1, C 1/2 = 8 · 10-9M). Higher concentrations of SkQ1 are required to block necrosis initiated by reactive oxygen species (ROS). In mice, SkQ1

Antibacterial Properties of 3 H-Spiro[1-benzofuran-2,1’-cyclohexane] Derivatives from Heliotropium filifolium

Directory of Open Access Journals (Sweden)

Marcela Wilkens

2008-10-01

Full Text Available A re-examination of cuticular components of Heliotropium filifolium allowed the isolation of four new compounds: 3’-hydroxy-2’,2’,6’-trimethyl-3H-spiro[1-benzo-furan-2,1’-cyclohexane]-5-carboxylic acid(2, methyl 3’-acetyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (3, methyl 3’-isopentanoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (4 and methyl 3’-benzoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (5.Compounds 2-5 were identified by their spectroscopic analogies with filifolinol (1, and their structures confirmed by chemical correlation with 1. The antimicrobial properties of the compounds were tested against Gram positive and Gram negative bacteria. Some of them proved to be active against Gram positive, but inactive against Gram negative bacteria. In searching for structure-activity relationships from the obtained MIC values, lipophilicity was shown to be an important variable.

The SUVR4 histone lysine methyltransferase binds ubiquitin and converts H3K9me1 to H3K9me3 on transposon chromatin in Arabidopsis.

Directory of Open Access Journals (Sweden)

Silje V Veiseth

2011-03-01

Full Text Available Chromatin structure and gene expression are regulated by posttranslational modifications (PTMs on the N-terminal tails of histones. Mono-, di-, or trimethylation of lysine residues by histone lysine methyltransferases (HKMTases can have activating or repressive functions depending on the position and context of the modified lysine. In Arabidopsis, trimethylation of lysine 9 on histone H3 (H3K9me3 is mainly associated with euchromatin and transcribed genes, although low levels of this mark are also detected at transposons and repeat sequences. Besides the evolutionarily conserved SET domain which is responsible for enzyme activity, most HKMTases also contain additional domains which enable them to respond to other PTMs or cellular signals. Here we show that the N-terminal WIYLD domain of the Arabidopsis SUVR4 HKMTase binds ubiquitin and that the SUVR4 product specificity shifts from di- to trimethylation in the presence of free ubiquitin, enabling conversion of H3K9me1 to H3K9me3 in vitro. Chromatin immunoprecipitation and immunocytological analysis showed that SUVR4 in vivo specifically converts H3K9me1 to H3K9me3 at transposons and pseudogenes and has a locus-specific repressive effect on the expression of such elements. Bisulfite sequencing indicates that this repression involves both DNA methylation-dependent and -independent mechanisms. Transcribed genes with high endogenous levels of H3K4me3, H3K9me3, and H2Bub1, but low H3K9me1, are generally unaffected by SUVR4 activity. Our results imply that SUVR4 is involved in the epigenetic defense mechanism by trimethylating H3K9 to suppress potentially harmful transposon activity.

In vitro metabolism of 2,2',3,4',5,5',6-heptachlorobiphenyl(CB187) with liver microsomes of rats, hamsters and guinea pigs

Energy Technology Data Exchange (ETDEWEB)

Koga, N.; Ohta, C.; Kanamaru, T. [Nakamura Gakuen Univ., Fukuoka (Japan); Haraguchi, K. [Daiichi Coll. of Pharmaceutical Sciences, Fukuoka (Japan); Kato, Y.; Yamada, S. [Univ. of Shizuoka, Shizuoka (Japan)

2004-09-15

PCB congeners possess extremely high lipophilicity and biological stability, and as a result they are not easily eliminated from the body once ingested. In particular, not only 2,4,5-trichlorosubstituted but also 6 or more chlorine-substituted PCBs such as 2,2',3',4,4',5-hexa-chlorobiphenyl (hexaCB) (CB138), 2,2',4,4',5,5'-hexaCB (CB153), 2,2',3,4,4',5,5'-heptachloro-biphenyl (heptaCB) (CB180) and 2,2',3,4',5,5',6-heptaCB (CB187) have been detected in blood and adipose tissues of mammals and human mother's milk at higher concentration. In addition, the 4-hydroxy (OH)-metabolite of CB187 has been reported to be present in human blood at the highest concentration of that derived from other PCB congeners. Although CB187, a tri-ortho-PCB, is one of the minor component in the commercial PCB preparations such as Clophen, Aroclor and Kanechlor, the toxic equivalency factor (TEF) which is used for dioxin-like PCB congeners including coplanar-PCBs and mono-ortho-PCBs to assess the potency of the toxicity has not been set up for di- and tri-ortho-PCB congeners. These facts indicate that 4-OH-PCB187 become more persistent and more important toxicologically than the parent CB187. However, there is little report about biotransformation in vivo or in vitro of CB187 in animals. Therefore, we examined CB187 metabolism by liver microsomes of rats, hamsters and guinea pigs.

CPAD, Curated Protein Aggregation Database: A Repository of Manually Curated Experimental Data on Protein and Peptide Aggregation.

Science.gov (United States)

Thangakani, A Mary; Nagarajan, R; Kumar, Sandeep; Sakthivel, R; Velmurugan, D; Gromiha, M Michael

2016-01-01

Accurate distinction between peptide sequences that can form amyloid-fibrils or amorphous β-aggregates, identification of potential aggregation prone regions in proteins, and prediction of change in aggregation rate of a protein upon mutation(s) are critical to research on protein misfolding diseases, such as Alzheimer's and Parkinson's, as well as biotechnological production of protein based therapeutics. We have developed a Curated Protein Aggregation Database (CPAD), which has collected results from experimental studies performed by scientific community aimed at understanding protein/peptide aggregation. CPAD contains more than 2300 experimentally observed aggregation rates upon mutations in known amyloidogenic proteins. Each entry includes numerical values for the following parameters: change in rate of aggregation as measured by fluorescence intensity or turbidity, name and source of the protein, Uniprot and Protein Data Bank codes, single point as well as multiple mutations, and literature citation. The data in CPAD has been supplemented with five different types of additional information: (i) Amyloid fibril forming hexa-peptides, (ii) Amorphous β-aggregating hexa-peptides, (iii) Amyloid fibril forming peptides of different lengths, (iv) Amyloid fibril forming hexa-peptides whose crystal structures are available in the Protein Data Bank (PDB) and (v) Experimentally validated aggregation prone regions found in amyloidogenic proteins. Furthermore, CPAD is linked to other related databases and resources, such as Uniprot, Protein Data Bank, PUBMED, GAP, TANGO, WALTZ etc. We have set up a web interface with different search and display options so that users have the ability to get the data in multiple ways. CPAD is freely available at http://www.iitm.ac.in/bioinfo/CPAD/. The potential applications of CPAD have also been discussed.

Safety assessment of decyl glucoside and other alkyl glucosides as used in cosmetics.

Science.gov (United States)

Fiume, Monice M; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

2013-01-01

The Cosmetic Ingredient Review (CIR) Expert Panel assessed the safety of 19 alkyl glucosides as used in cosmetics and concluded that these ingredients are safe in the present practices of use and concentration when formulated to be nonirritating. Most of these ingredients function as surfactants in cosmetics, but some have additional functions as skin-conditioning agents, hair-conditioning agents, or emulsion stabilizers. The Panel reviewed the available animal and clinical data on these ingredients. Since glucoside hydrolases in human skin are likely to break down these ingredients to release their respective fatty acids and glucose, the Panel also reviewed CIR reports on the safety of fatty alcohols and were able to extrapolate data from those previous reports to support safety.

Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

Energy Technology Data Exchange (ETDEWEB)

King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [Nottingham Univ. (United Kingdom). School of Chemistry; Tuna, Floriana; McInnes, Eric J.L. [Manchester Univ. (United Kingdom). School of Chemistry

2013-04-26

Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). [German] Die direkte Oxidation eines Triamidoamin-Uran(III)-Komplexes mit Trimethyl-N-oxid liefert einen terminalen Uran(V)-Mono(oxo)komplex, der das erste gesicherte Beispiel eines Uran(V)-Einzelmolekuelmagnets ist. Dieser monometallische Komplex zeigt eindeutig, dass ein starkes axiales und somit anisotropes Ligandenfeld die begrenzte magnetische Anisotropie von Uran(V) beseitigen kann.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Surface modified Al2O3 in fluorinated polyimide/Al2O3 nanocomposites: Synthesis ... show the characteristic surface plasmon resonance of gold nanoparticles. pp 947-956. Structural and optical properties of Zn doped CuInS2 thin films .... Synthesis and characterization of nickel/barium hexa-aluminate composite coatings.

African Journal of Biotechnology Vol

African Journals Online (AJOL)

DR TONUKARI NYEROVWO

2011-01-10

Jan 10, 2011 ... reverse-transcription polymerase chain reaction; CTAB, cetyl trimethyl ammonium .... Shanghai Sangon Biological Engineering Technology & Services. Co., Ltd. ..... tolerance in harvested banana fruit. Postharvest Biol.

Norisoprenoids from the Brown Alga Sargassum naozhouense Tseng et Lu

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Yan Peng

2018-02-01

Full Text Available A new C11-norisoprenoid derivative, sargassumone (1, has been isolated from Sargassum naozhouense together with six known norisoprenoids and a highly oxygenated cyclopentene: (2R,6S,8S,9S-hexahydro-2,9-dihydroxy-4,4,8-trimethyl-6-acetyloxy-3(2H-benzofuranone (2, (6S,8S,9R-hexahydro-6,9-dihydroxy-4,4,8-trimethyl-2(2H-benzofuranone (3, (6S,8S,9R-hexahydro-6,9-dihydroxy-4,4,8-trimethyl-2(2H-benzofuranone (4, loliolide (5, (+-epiloliolide (6, spheciospongones A (7, and (+-kjellmanianone (8. Compound 1 was identified on the basis of nuclear magnetic resonance (NMR and mass spectrometry (MS analysis, and the absolute stereochemistry was defined by NOESY spectroscopy, minimizing energy calculation, and circular dichroism (CD spectra. The known compounds 2–8, isolated from S. naozhouense for the first time, were identified by comparison of their physical and spectroscopic data with those reported in the literature. Compound 6 was tested for its inhibitory activity against protein tyrosine phosphatase 1B (PTP1B, antioxidant activity with 1,1-diphyl-2-picrylhydrazyl (DPPH free radicals, and antimicrobial activity against resistant clinical isolates of Candida albicans, methicillin-resistant Staphylococcus aureus (MRSA, and Escherichia coli.

Synthesis And Characterization Of Mebrofenin For Hepatobiliary Imaging

International Nuclear Information System (INIS)

Purwoko; Tamat, Swasono R.; Yunita, Fitri; Kristanti, Eti

2003-01-01

Mebrofenin labeled with Technetium-99m is a new radiopharmaceutical having superior and ideal characteristic as a hepatobiliary-imaging agent. The synthesis and characterization of Mebrofenin (3-Bromo-2,4,6-trimethyl acetanilido iminodiacetic acid) as IDA derivative has been carried out involving three steps of reaction i.e. : acetyllization of 2,4,6-Trimethyl aniline to get 2,4,6-trimethyl chloro acetanilide which upon bromination gives the intermediate bromotrimethyl derivative and [mally by nucleophilic substitution this intermediate product with iminodiacetic acid (IDA) gives mebrofenin. The acetylation and bromination reactions were carried out in acetic acid condition while the substitution was carried out by reflux for 5 hours in ethanol and water adjusted at pH 11. The ethanol was then removed under low pressure, and the unreacted compound was removed by filtration. The filtrate was adjusted to pH 2 - 2.5, and the resulting mebrofenin was isolated by filtration and recrystallized 3 times in ethanol. Characterization of the mebrofenin product was performed by observing its melting point (197-l99 o C), ultra violet and infra red spectra as well as mass spectrometric and high performance liquid chromatographic analysis. The results showed that the product was highly pure and the yield was around 20%

Preparation of Na4UO2(CO3)3 in presence of Ce-141. I, Influence of the post-reaction time in the concentration of anion species of Ce-141

International Nuclear Information System (INIS)

Lopez M, B.E.; Rodriguez S, A.; Iturbe G, J.L.

1991-10-01

An effective condition to minimize the presence of Ce-141, in the final product of recovery like hexa hydrated uranyl nitrate has been obtained. It is considered to this condition like a pre purification stage in the recovery process of the non-fissioned residual uranium in the fission production of Mo-99. (Author)

Aroma characterization of tangerine hybrids by gas-chromatography-olfactometry and sensory evaluation

Science.gov (United States)

Although a total of 150 volatiles were detected by GC-MS, only 49 aroma active peaks were found in a consensus by the three panelists. Aldehydes were the most important group with odor activity, as well as monoterpenes, esters, alcohols and ketones. 1,8-Cineole, ·-myrcene, (E,E)-2,4-nonadienal, hexa...

Preparation of Na{sub 4}UO{sub 2}(CO{sub 3}){sub 3} in presence of Ce-141. I, Influence of the post-reaction time in the concentration of anion species of Ce-141; Preparacion del Na{sub 4}UO{sub 2}(CO{sub 3}){sub 3} en presencia de Ce-141. I, Influencia del tiempo de post-reaccion en la concentracion de especies anionicas de Ce-141

Energy Technology Data Exchange (ETDEWEB)

Lopez M, B.E.; Rodriguez S, A.; Iturbe G, J.L

1991-10-15

An effective condition to minimize the presence of Ce-141, in the final product of recovery like hexa hydrated uranyl nitrate has been obtained. It is considered to this condition like a pre purification stage in the recovery process of the non-fissioned residual uranium in the fission production of Mo-99. (Author)

Characterization and two-dimensional crystallization of membrane component AlkB of the medium-chain alkane hydroxylase system from Pseudomonas putida GPo1.

Science.gov (United States)

Alonso, Hernan; Roujeinikova, Anna

2012-11-01

The alkane hydroxylase system of Pseudomonas putida GPo1 allows it to use alkanes as the sole source of carbon and energy. Bacterial alkane hydroxylases have tremendous potential as biocatalysts for the stereo- and regioselective transformation of a wide range of chemically inert unreactive alkanes into valuable reactive chemical precursors. We have produced and characterized the first 2-dimensional crystals of the integral membrane component of the P. putida alkane hydroxylase system, the nonheme di-iron alkane monooxygenase AlkB. Our analysis reveals for the first time that AlkB reconstituted into a lipid bilayer forms trimers. Addition of detergents that do not disrupt the AlkB oligomeric state (decyl maltose neopentyl glycol [DMNG], lauryl maltose neopentyl glycol [LMNG], and octaethylene glycol monododecyl ether [C(12)E(8)]) preserved its activity at a level close to that of the detergent-free control sample. In contrast, the monomeric form of AlkB produced by purification in n-decyl-β-D-maltopyranoside (DM), n-dodecyl-β-D-maltopyranoside (DDM), octyl glucose neopentyl glycol (OGNG), and n-dodecyl-N,N-dimethylamine-N-oxide (LDAO) was largely inactive. This is the first indication that the physiologically active form of membrane-embedded AlkB may be a multimer. We present for the first time experimental evidence that 1-octyne acts as a mechanism-based inhibitor of AlkB. Therefore, despite the lack of any significant full-length sequence similarity with members of other monooxygenase classes that catalyze the terminal oxidation of alkanes, AlkB is likely to share a similar catalytic mechanism.

Immobilization of cholesterol esterase in mesoporous silica materials and its hydrolytic activity toward diethyl phthalate

Energy Technology Data Exchange (ETDEWEB)

Orita, Toru, E-mail: nqj45366@nifty.com [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Taiyo Kagaku Co. Ltd., 800 Yamada-cho, Yokkaichi, Mie 512-1111 (Japan); Tomita, Masahiro [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Saito, Takao; Nishida, Nasakazu; Kato, Katsuya [National Institute of Advanced Industrial Science and Technology, 2266-78 Anagahora, Moriyamaku, Nagoya, Aichi 463-8560 (Japan)

2012-05-01

Cholesterol esterase (CE, cholesteryl ester hydrolase, EC 3.1.1.13) from porcine pancreas (molecular weight 400-500 kDa) exhibits hydrolytic activity toward various toxic organic phthalate esters. CE was confined in the nanospace (diameter 3-30 nm) of five types of mesoporous silica (MPS) that differ in structural properties such as pore diameter, pore volume, and particle morphology. These structural properties were characterized by transmission electron microscopy, small-angle X-ray diffraction, N{sub 2} adsorption-desorption experiments, solid-state {sup 13}C nuclear magnetic resonance (NMR), and solid-state {sup 29}Si NMR. Catalytic activities of immobilized and free CE were evaluated by the hydrolysis of diethyl phthalate in phosphate buffer solutions containing an organic cosolvent. Optimal activity recovery was achieved when CE was immobilized in n-decane-functionalized MPS, which had a large pore size (22.5 nm). The immobilization also protected against effects of temperature within the range 30 Degree-Sign C-60 Degree-Sign C; CE immobilized in n-decyl-functionalized MPS exhibited better thermal stability than in non-functionalized MPS or free CE. Moreover, it retained approximately 60% of its catalytic activity even after six catalytic cycles. - Highlights: Black-Right-Pointing-Pointer The highest activity of immobilized CE was shown in MPS with a pore size of 22.5 nm. Black-Right-Pointing-Pointer Catalytic efficiency improved when MPS was functionalized by n-decyl substitution. Black-Right-Pointing-Pointer Immobilized CE exhibited good thermal stability and reusability. Black-Right-Pointing-Pointer Organic co-solvent and the substrate structures affected enzyme activities.

Facile and High-Yielding Synthesis of TAM Biradicals and Monofunctional TAM Radicals.

Science.gov (United States)

Trukhin, Dmitry V; Rogozhnikova, Olga Yu; Troitskaya, Tatiana I; Vasiliev, Vladimir G; Bowman, Michael K; Tormyshev, Victor M

2016-04-01

Facile and high-yielding procedures for synthesis of monocarboxylic acid derivatives of triarylmethyl radicals (TAMs) were developed. Reaction of methyl thioglycolate with tris(2,3,5,6-tetrathiaaryl)methyl cation smoothly afforded the monosubstituted TAM derivative, which was hydrolyzed to a monocarboxylic acid, with the TAM moiety attached to thioglycolic acid via the sulfur atom. Alternatively, the diamagnetic tricarboxylic acid precursor of Finland trityl was transformed to a trimethyl ester and partially hydrolyzed under controlled conditions. The diester product was isolated and the remaining fractions were converted back to the trimethyl ester for production of more diester. The first representatives of TAM biradicals with different TAM cores and interspin distances were obtained by reaction of these new TAM monocaboxylic acids with N,N'-dimethylethylenediamine.

New 3H-Indole Synthesis by Fischer’s Method. Part I.

Directory of Open Access Journals (Sweden)

Sami Sajjadifar

2010-04-01

Full Text Available Methyl indolenines (4a-c and(5a-c were prepared in high yield by a Fischer indole synthesis reaction of o,m-tolylhydrazine hydrochlorides (1a-b with isopropyl methyl ketone (2 and 2-methylcyclohexanone (3 in acetic acid at room temperature. o,p- Nitrophenylhydrazines (1c-d were reacted with 2-methylcyclohexanone (3 in acetic acid at reflux to give nitroindolenines (5d-e, while the attempted reactions of o,p-nitrohydrazines with isopropyl methyl ketone (2 in acetic acid were not successful. Compounds(1c-d were reacted with isopropyl methyl ketone (2 in acetic acid/HCl to give 2,3,3-trimethyl-5-nitro-indolenine (4e and 2,3,3-trimethyl-7-nitroindolenine (4d.

Combination of acid-resistor and -scavenger improves the SEI stability and cycling ability of tin–nickel battery anodes in LiPF6-containing electrolyte

International Nuclear Information System (INIS)

Choo, Myeong-Ho; Nguyen, Cao Cuong; Hong, Sukhyun; Kwon, Yo Han; Woo, Sang-Wook; Kim, Je Young; Song, Seung-Wan

2013-01-01

Control of electrode–electrolyte interfacial reactivity and the formation of the solid electrolyte interphase (SEI) layer is a key technology for high performance rechargeable lithium batteries. Here we present the first report on a promising interfacial approach for Sn–Ni electrode that the use of acid-resisting and -scavenging fluorine-dopant on Sn combined with acid-scavenging trimethyl phosphite electrolyte additive to LiPF 6 -contiaing carbonate-based organic electrolyte improves the interfacial stability of Sn to acidic electrolyte species. As a result, a stable SEI layer consisting of a plenty of carbonate decomposition products forms and cycling ability significantly improves, in contrast to less efficient SEI formation and rapid performance fade for the electrodes without fluorine-dopant or trimethyl phosphite additive

A second mutation associated with apparent [beta]-hexosaminidase A pseudodeficiency: Identification and frequency estimation

Energy Technology Data Exchange (ETDEWEB)

Cao, Z.; Chabot, T.; Triggs-Raine, B.L. (Univ. of Manitoba, Winnepeg (Canada)); Natowicz, M.R.; Prence, E.M. (Shriver Center for Mental Retardation, Waltham, MA (United States) Harvard Medical School, Boston, MA (United States)); Kaback, M.M.; Lim-Steele, S.T.; Brown, D. (Children' s Hospital, San Diego, CA (United States) Univ. of California, San Diego, CA (United States))

1993-12-01

Deficient activity of [beta]-hexosaminidase A (Hex A), resulting from mutations in the HEXA gene, typically causes Tay-Sachs disease. However, healthy individuals lacking Hex A activity against synthetic substrates (i.e., individuals who are pseudodeficient) have been described. Recently, an apparently benign C[sub 739]-to-T (Arg247Trp) mutation was found among individuals with Hex A levels indistinguishable from those of carriers of Tay-Sachs disease. This allele, when in compound heterozygosity with a second [open quotes]disease-causing[close quotes] allele, results in Hex A pseudodeficiency. The authors examined the HEXA gene of a healthy 42-year-old who was Hex A deficient but did not have the C[sub 739]-to-T mutation. The HEXA exons were PCR amplified, and the products were analyzed for mutations by using restriction-enzyme digestion or single-strand gel electrophoresis. A G[sub 805]-to-A (Gly269Ser) mutation associated with adult-onset G[sub m2] gangliosidosis was found on one chromosome. A new mutation, C[sub 745]-to-T (Arg 249Trp), was identified on the second chromosome. This mutation was detected in an additional 4/63 (6%) non-Jewish and 0/218 Ashkenazi Jewish enzyme-defined carriers. Although the Arg249Trp change may result in a late-onset form of G[sub M2] gangliosidosis, any phenotype must be very mild. This new mutation and the benign C[sub 739]-to-T mutation together account for [approximately]38% of non-Jewish enzyme-defined carriers. Because carriers of the C[sub 739]-to-T and C[sub 745]-to-T mutations cannot be differentiated from carriers of disease-causing alleles by using the classical biochemical screening approaches, DNA-based analyses for these mutations should be offered for non-Jewish enzyme-defined heterozygotes, before definitive counseling is provided. 46 refs., 5 figs., 2 tabs.

Synthesis and crystal structures of multifunctional tosylates as basis for star-shaped poly(2-ethyl-2-oxazolines

Directory of Open Access Journals (Sweden)

Richard Hoogenboom

2010-09-01

Full Text Available The synthesis of well-defined polymer architectures is of major importance for the development of complex functional materials. In this contribution, we discuss the synthesis of a range of multifunctional star-shaped tosylates as potential initiators for the living cationic ring-opening polymerization (CROP of 2-oxazolines resulting in star-shaped polymers. The synthesis of the tosylates was performed by esterification of the corresponding alcohols with tosyl chloride. Recrystallization of these tosylate compounds afforded single crystals, and the X-ray crystal structures of di-, tetra- and hexa-tosylates are reported. The use of tetra- and hexa-tosylates, based on (dipentaerythritol as initiators for the CROP of 2-ethyl-2-oxazoline, resulted in very slow initiation and ill-defined polymers, which is most likely caused by steric hindrance in these initiators. As a consequence, a porphyrin-cored tetra-tosylate initiator was prepared, which yielded a well-defined star-shaped poly(2-ethyl-2-oxazoline by CROP as demonstrated by SEC with RI, UV and diode-array detectors, as well as by 1H NMR spectroscopy.

Ammonia Uptake and Release in the MnX2–NH3 (X = Cl, Br Systems and Structure of the Mn(NH3nX2 (n = 6, 2 Ammines

Directory of Open Access Journals (Sweden)

Duncan H. Gregory

2012-04-01

Full Text Available Hexa-ammine complexes, Mn(NH36X2 (X = Cl, Br, have been synthesized by ammoniation of the corresponding transition metal halide and characterized by Powder X-ray diffraction (PXRD and Raman spectroscopy. The hexa-ammine complexes are isostructural (Cubic, Fm-3m, Z = 4; a = 10.2742(6 Å and 10.527(1 Å for X = Cl, Br respectively. Temperature programmed desorption (TPD demonstrated that ammonia release from Mn(NH36X2 complexes occurred in three stages corresponding to the release of 4, 1 and 1 NH3 equivalents respectively. The chloride and bromide both exhibit a deammoniation onset temperature below 323 K. The di-ammoniates from the first desorption step were isolated during TPD measurements and their crystal structures determined by Rietveld refinement against PXRD data (X = Cl: orthorhombic Cmmm, a = 8.1991(9 Å, b = 8.2498(7 Å, c = 3.8212(4 Å, Z = 2; X = Br: orthorhombic Pbam, a = 6.0109(5 Å, b = 12.022(1 Å, c = 4.0230(2 Å, Z = 2.

PCBs in air, soil and milk in industrialized and urban areas of KwaZulu-Natal, South Africa

International Nuclear Information System (INIS)

Batterman, S.; Chernyak, S.; Gouden, Y.; Hayes, J.; Robins, T.; Chetty, S.

2009-01-01

Information regarding polychlorinated biphenyls (PCBs) in environmental media in Africa is limited. This paper presents results of a monitoring program conducted in KwaZulu-Natal Province, South Africa designed to characterize levels, trends and sources of airborne PCBs. Particulate and vapor samples were sampled over the 2004-2005 period at three sites. The total PCB concentration averaged 128 ± 47 pg m -3 , and levels were highest in winter. Tri- through hexa-congeners predominated, and the vapor fraction was predominant. Several tetra- through hexa-chlorinated congeners had levels comparable to those at urban sites in the northern hemisphere, but hepta- through deca-congeners resembled levels at background sites. PCB source areas, deduced using spatial and temporal patterns, compositional information and trajectory analyses, likely included local, regional and global sources. Soils at three rural sites showed high PCB concentrations, and milk from a local dairy showed PCB concentrations comparable to USA levels in year 2000. - Airborne PCBs in KwaZulu-Natal, South Africa have similar concentrations but distinctive congener patterns compared to areas of historically high PCB use

PCBs in air, soil and milk in industrialized and urban areas of KwaZulu-Natal, South Africa

Energy Technology Data Exchange (ETDEWEB)

Batterman, S. [Environmental Health Sciences, University of Michigan School of Public Health, 109 Observatory Street, Ann Arbor, MI 48109-2029 (United States)], E-mail: stuartb@umich.edu; Chernyak, S. [Environmental Health Sciences, University of Michigan School of Public Health, 109 Observatory Street, Ann Arbor, MI 48109-2029 (United States); Gouden, Y. [Centre for Occupational and Environmental Health, University of KwaZulu-Natal, 719 Umbilo Road, Private Bag 7, Congella, 4013 Durban (South Africa); Hayes, J.; Robins, T. [Environmental Health Sciences, University of Michigan School of Public Health, 109 Observatory Street, Ann Arbor, MI 48109-2029 (United States); Chetty, S. [Pollution Control Support Unit, Health Department, eThekwini Municipality (South Africa)

2009-02-15

Information regarding polychlorinated biphenyls (PCBs) in environmental media in Africa is limited. This paper presents results of a monitoring program conducted in KwaZulu-Natal Province, South Africa designed to characterize levels, trends and sources of airborne PCBs. Particulate and vapor samples were sampled over the 2004-2005 period at three sites. The total PCB concentration averaged 128 {+-} 47 pg m{sup -3}, and levels were highest in winter. Tri- through hexa-congeners predominated, and the vapor fraction was predominant. Several tetra- through hexa-chlorinated congeners had levels comparable to those at urban sites in the northern hemisphere, but hepta- through deca-congeners resembled levels at background sites. PCB source areas, deduced using spatial and temporal patterns, compositional information and trajectory analyses, likely included local, regional and global sources. Soils at three rural sites showed high PCB concentrations, and milk from a local dairy showed PCB concentrations comparable to USA levels in year 2000. - Airborne PCBs in KwaZulu-Natal, South Africa have similar concentrations but distinctive congener patterns compared to areas of historically high PCB use.

Structure-based drug design of novel peptidomimetic cellulose derivatives as HCV-NS3 protease inhibitors.

Science.gov (United States)

Saleh, Noha A; Elshemey, Wael M

2017-10-15

Hepatitis C Virus (HCV) represents a global health threat not only due to the large number of reported worldwide HCV infections, but also due to the absence of a reliable vaccine for its prevention. HCV NS3 protease is one of the most important targets for drug design aiming at the deactivation of HCV. In the present work, molecular docking simulations are carried out for suggested novel NS3 protease inhibitors applied to the Egyptian genotype 4. These inhibitors are modifications of dimer cellulose by adding a hexa-peptide to the cellulose at one of the positions 2, 3, 6, 2', 3' or 6'. Results show that the inhibitor compound with the hexa-peptide at position 6 shows significantly higher simulation docking score with HCV NS3 protease active site. This is supported by low total energy value of docking system, formation of two H-bonds with HCV NS3 protease active site residues, high binding affinity and increased stability in the interaction system. Copyright © 2017 Elsevier Inc. All rights reserved.

Bioconcentration and acute toxicity of polycyclic musks in two benthic organisms (Chironomus riparius and Lumbriculus variegatus)

NARCIS (Netherlands)

Artola-Garicano, E.; Sinnige, T.L.; Holsteijn, I. van; Vaes, W.H.J.; Hermens, J.L.M.

2003-01-01

In the current study, the bioconcentration behavior and acute toxicity of two polycyclic musks, Tonalide® 7-acetyl-1,1,3,4,4,6,-hexamethyl-1,2,3,4,-tetrahydronaphthalene (AHTN) and Galaxolide® 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methyl-cyclopenta[γ]-2- benzopyran (HHCB), were studied in two

supp1.doc

Indian Academy of Sciences (India)

hexa decane]-2'(7'),4',6',8'-tetraene-2,5,13',15'-tetrone (cis-3a). Pale pink solid, mp: 118-120 oC; Rf = 0.23 (60% ethylacetate: petroleum ether); IR (KBr): 1196, 1352, 1715, 2961, 3235 cm-1; 1H NMR (500 MHz, CDCl3): δ 2.86 (d, 1H, J = 18.3 ...

Superresolution imaging reveals structurally distinct periodic patterns of chromatin along pachytene chromosomes

Science.gov (United States)

Fournier, David; Redl, Stefan; Best, Gerrit; Borsos, Máté; Tiwari, Vijay K.; Tachibana-Konwalski, Kikuë; Ketting, René F.; Parekh, Sapun H.; Cremer, Christoph; Birk, Udo J.

2015-01-01

During meiosis, homologous chromosomes associate to form the synaptonemal complex (SC), a structure essential for fertility. Information about the epigenetic features of chromatin within this structure at the level of superresolution microscopy is largely lacking. We combined single-molecule localization microscopy (SMLM) with quantitative analytical methods to describe the epigenetic landscape of meiotic chromosomes at the pachytene stage in mouse oocytes. DNA is found to be nonrandomly distributed along the length of the SC in condensed clusters. Periodic clusters of repressive chromatin [trimethylation of histone H3 at lysine (Lys) 27 (H3K27me3)] are found at 500-nm intervals along the SC, whereas one of the ends of the SC displays a large and dense cluster of centromeric histone mark [trimethylation of histone H3 at Lys 9 (H3K9me3)]. Chromatin associated with active transcription [trimethylation of histone H3 at Lys 4 (H3K4me3)] is arranged in a radial hair-like loop pattern emerging laterally from the SC. These loops seem to be punctuated with small clusters of H3K4me3 with an average spread larger than their periodicity. Our findings indicate that the nanoscale structure of the pachytene chromosomes is constrained by periodic patterns of chromatin marks, whose function in recombination and higher order genome organization is yet to be elucidated. PMID:26561583

Polyphenolics free DNA isolation and optimization of PCR-RAPD for ...

African Journals Online (AJOL)

, and good quality high molecular weight DNA samples. DNA was isolated from the mature and fresh young tender leaves obtained from various Italian wild populations of fennel. We performed a modified cetyl trimethyl ammonium bromide ...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

piperazino- and 5-morpholinoacetyl-2,2,4-trimethyl-1, 5-benzodiazepines ... Department of Physics, Anna Adarsh College for Women, Chennai 600 040, Tamil Nadu, India; P G & Research Department of Physics, Queen Mary's College, Chennai ...

Sonochemical precipitation of amorphous uranium phosphates from trialkyl phosphate solutions and their thermal conversion to UP2O7

Czech Academy of Sciences Publication Activity Database

Doroshenko, I.; Žurková, J.; Moravec, Z.; Bezdička, Petr; Pinkas, J.

2015-01-01

Roč. 26, SEP (2015), s. 157-162 ISSN 1350-4177 Institutional support: RVO:61388980 Keywords : Uranium * Phosphates * Sonochemistry * Nuclear waste * Trimethyl phosphate * Triethyl phosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 4.556, year: 2015

Synthesis and crystal structure of trans-[Ni(pyzdcH)M 2 (H 2 O) 2 ...

African Journals Online (AJOL)

The determined structure of the title compound C24H20Ni2N8O20 consists of the mononuclear trans-[Ni(pyzdc)2(H2O)2], (pyzdc = pyrazine-2,3- dicarboxylate). The Ni(II) atom is hexa-coordinated by two (pyzdcH)- groups and two water molecules. The coordinated water molecules are in trans-diaxial positions and the ...

Determination of the radioactive concentration of 137Cs in water

International Nuclear Information System (INIS)

1986-01-01

The recently accepted standard method to determine the radioactive concentration of 137 Cs in water is based on the selective retention of cesium ions on ammonium-phosphorous-molybdate followed by the dissolution of the sorbent and the selective precipitation of cesium-hexa-chloro-platinate. The radioactive concentration is determined by the measurement of β disintegration rate of the preparate. (V.N.)

Studies on new complexes of dioxo uranium(VI) and thorium(IV) with some schiff bases derived from trimethoprime salicyldehyde and o-vanillin (Paper No. AL-50)

International Nuclear Information System (INIS)

Pujar, M.A.; Pirgonde, B.R.

1990-02-01

Dioxouranium(VI) and thorium(IV) form 1:1(Metal:Ligands) complexes with some schiff bases. The complexes have been characterized through elemental analyses, electronic and IR spectral, conductance and magnetic susceptibility measurements. They are considered dimeric or polymeric hexa or octa-coordinated arrangement around metal ion moiety. Force constants and U-O bond lengths have been calculated. (author). 1 tab

Low-Temperature Band Transport and Impact of Contact Resistance in Organic Field-Effect Transistors Based on Single-Crystal Films of Ph-BTBT-C10

Science.gov (United States)

Cho, Joung-min; Mori, Takehiko

2016-06-01

Transistors based on single-crystal films of 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) fabricated using the blade-coating method are investigated by the four-probe method down to low temperatures. The four-probe mobility is as large as 18 cm2/V s at room temperature, and increases to 45 cm2/V s at 80 K. At 60 K the two-probe mobility drops abruptly by about 50%, but the mobility drop is mostly attributed to the increase of the source resistance. The carrier transport in the present single-crystal film is regarded as essentially bandlike down to 30 K.

Gold-catalyzed oxidation of substituted phenols by hydrogen peroxide

KAUST Repository

Cheneviere, Yohan; Caps, Valerie; Tuel, Alain

2010-01-01

Gold nanoparticles deposited on inorganic supports are efficient catalysts for the oxidation of various substituted phenols (2,6-di-tert-butyl phenol and 2,3,6-trimethyl phenol) with aqueous hydrogen peroxide. By contrast to more conventional

Chemisorption of uranium hexa-fluoride on sodium fluoride pellets

Energy Technology Data Exchange (ETDEWEB)

Kalburgi, A K; Sanyal, A; Puranik, V D; Bhattacharjee, B [Chemical Technology Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

This paper comprises kinetics of chemical reaction or rather chemisorption of uranium hexafluoride gas on sodium fluoride pellets. The chemisorption is essentially irreversible at room temperature, while the process reverses at high temperature above 280 deg C. This chemisorption process was experimentally conducted in static condition at room temperature and its kinetics was studied. In the experiments, practically pure UF{sub 6} was used and the effects of gas pressure and weight of NaF pellets, were studied. In this heterogenous reaction, in which diffusion through ash layer is followed by chemical reaction, the reaction part is instantaneous and is first order with respect to gas concentration. Since the process of chemisorption is not only pure chemical reaction but also gas diffusion through ash layer, the rate constant depreciates with the percentage loading of UF{sub 6} on NaF pellets. The kinetic equation for the above process has been established for a particular size of NaF pellets and pellet porosity. (author). 5 refs., 3 figs., 3 tabs.

Determination of the ionisation potential of certain hydrocarbons in the liquid phase

International Nuclear Information System (INIS)

Casanovas, J.; Grob, R.; Brunet, G.; Sabattier, R.; Guelfucci, J.P.; Blanc, D.

1978-01-01

The first results obtained are presented on the determination of the ionisation potential of four alkanes (n-hexane, n-pentane, cyclopentane and trimethyl-2,2,4 pentane) in the liquid phase. In the gaseous phase, the ionisation potential values of these hydrocarbons are respectively 10.18 eV for n-hexane, 10.35 eV for n-pentane, 10.53 eV for cyclopentane and 9.86 eV for trimethyl-2,2,4 pentane. Consequently rare gas resonance lamps (krypton and Xenon) were made, sealed and excited by an ultra-high frequency wave, which emit photons in the energy field concerned, i.e. from 8.5 eV to 11eV. The energy of the photons emitted by these lamps is respectively 8.44 eV (100%) and 9.57 eV (2%) for xenon and 10.03 eV (100%) and 10.64 eV (5%) for krypton. From the extent of the induced ionisation currents and particularly the value of the ratio of the currents induced by the photons of the krypton and xenon lamps, a minimum value of the ionisation potential drop can be deduced compared with the gas phase of 0.61 eV for n-hexane, 0.78 eV for n-pentane, 0.96 eV for cyclopentane and a maximum value of 1.42 eV for trimethyl-2,2,4 pentane [fr

VOCs emission characteristics and priority control analysis based on VOCs emission inventories and ozone formation potentials in Zhoushan

Science.gov (United States)

Wang, Qiaoli; Li, Sujing; Dong, Minli; Li, Wei; Gao, Xiang; Ye, Rongmin; Zhang, Dongxiao

2018-06-01

Zhoushan is an island city with booming tourism and service industry, but also has many developed VOCs and/or NOX emission industries. It is necessary to carry out regional VOCs and O3 pollution control in Zhoushan as the only new area owns the provincial economic and social administration rights. Anthropogenic VOCs emission inventories were built based on emission factor method and main emission sources were identified according to the emission inventories. Then, localized VOCs source profiles were built based on in-site sampling and referring to other studies. Furthermore, ozone formation potentials (OFPs) profiles were built through VOCs source profiles and maximum incremental reactivity (MIR) theory. At last, the priority control analysis results showed that industrial processes, especially surface coating, are the key of VOCs and O3 control. Alkanes were the most emitted group, accounting for 58.67%, while aromatics contributed the most to ozone production accounting for 69.97% in total OFPs. n-butane, m/p-xylene, i-pentane, n-decane, toluene, propane, n-undecane, o-xylene, methyl cyclohexane and ethyl benzene were the top 10 VOC species that should be preferentially controlled for VOCs emission control. However, m/p-xylene, o-xylene, ethylene, n-butane, toluene, propene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, ethyl benzene and 1,2,3-trimethyl benzene were the top 10 VOC species that required preferential control for O3 pollution control.

Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants

International Nuclear Information System (INIS)

Jardon S, C. C.; Olguin G, M. T.; Diaz N, M. C.

2009-01-01

In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants;Adsorcion de colorantes azul vegetal y azul acuarela por zeolitas naturales modificadas con surfactantes

Energy Technology Data Exchange (ETDEWEB)

Jardon S, C. C.; Olguin G, M. T. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Diaz N, M. C., E-mail: teresa.olguin@inin.gob.m [Instituto Tecnologico de Toluca, Av. Instituto Tecnologico s/n, Ex-Rancho la Virgen, 52140 Metepec, Estado de Mexico (Mexico)

2009-07-01

In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

Two distinct modes for propagation of histone PTMs across the cell cycle

DEFF Research Database (Denmark)

Alabert, Constance; Barth, Teresa K; Reverón-Gómez, Nazaret

2015-01-01

Epigenetic states defined by chromatin can be maintained through mitotic cell division. However, it remains unknown how histone-based information is transmitted. Here we combine nascent chromatin capture (NCC) and triple-SILAC (stable isotope labeling with amino acids in cell culture) labeling...... to track histone modifications and histone variants during DNA replication and across the cell cycle. We show that post-translational modifications (PTMs) are transmitted with parental histones to newly replicated DNA. Di- and trimethylation marks are diluted twofold upon DNA replication, as a consequence...... of new histone deposition. Importantly, within one cell cycle, all PTMs are restored. In general, new histones are modified to mirror the parental histones. However, H3K9 trimethylation (H3K9me3) and H3K27me3 are propagated by continuous modification of parental and new histones because the establishment...

Enhanced protein loading on a planar Si(111)-H surface with second generation NTA

Science.gov (United States)

Liu, Xiang; Han, Huan-Mei; Liu, Hong-Bo; Xiao, Shou-jun

2010-08-01

A Si(111)-H surface was modified via a direct reaction between Si-H and 1-undecylenic acid (UA) under microwave irradiation to form molecular monolayers with terminal carboxyl groups. After esterifying carboxylic acid being esterified with N-hydroxysuccinimide (NHS), aminobutyl nitrilotriacetic acid (ANTA) was bound to the silicon surface through amidation (pH = 8.0) between its primary amino group and NHS-ester, producing nitrilotriacetic acid (NTA) anions. Then hexa-histidine tagged thioredoxin-urodilatin (his-tagged protein) and FITC-labeled hexa-histidine tagged thioredoxin-urodilatin (FITC-his-tagged protein) can be anchored after NTA was coordinated with Ni 2+. Furthermore, the NTA-terminated chip was acidified with 0.1 M HCl and subsequently esterified with NHS and then amidated with ANTA again to produce a second generation NTA. Thus the surface density of nitrilotriacetic acid anions was improved and resultantly that of anchored proteins was also enhanced through the iterative reactions. Both multiple transmission-reflection infrared spectroscopy (MTR-IR) and fluorescence scanning measurements demonstrated a proximate 1.63 times of anchored proteins on the second generation NTA/Ni 2+ as that on the first generation NTA/Ni 2+ monolayer.

Making of Magnet Barium Ferit Anisotropic

International Nuclear Information System (INIS)

Idayati, Novrita; Dedi

2003-01-01

Barium Hexa ferrite (BaFe 12 O 19 ) is ceramic and materials which usually used for making of permanent magnet. In this research Barium Hexa ferrite were made Anisotropic, and applied for loudspeaker, electro motors, dynamo, KWh metre, etc. this Magnet is commonly used due to its high Induction of Remanen (Br) and coercivity (high Hc). Besides it applies a more simple and easier process technology, cheaper raw material, and easy to find it, hence the magnetic component is much cheaper. Powder Metallurgy was used for the process technology, by reacting all materials in the powder (oxide), with a certain size distribution and a tight preparation step. The next step was mixing ferrite and Barium Carbonate (in the form of oxide), calcination, compaction, cantering and characterisation. The Anisotropic particle effects a high Induce Remanen (Br) and of koersifitas (high Hc). All the process steps will is determine physical and chemical characteristics of the magnet. The best Magnet characteristic of the magnet produced in this research is Induction of Remanen (Br) = 4,27 kg, Coercivity (Hc) = 1,745 kOe, Energy Product max (BHmaks) = 2,31 MGOe

CCDC 959634: Experimental Crystal Structure Determination : octakis(mu~3~-Hydroxo)-undecakis(mu~2~-2-fluorobenzoato)-(N,N-dimethylformamide)-nitrato-hexa-aqua-hexa-terbium

KAUST Repository

Guillerm, Vincent; Weseliński, Łukasz J.; Belmabkhout, Youssef; Cairns, Amy J.; D'Elia, Valerio; Wojtas, Łukasz; Adil, Karim; Eddaoudi, Mohamed

2014-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Pore ordering in mesoporous matrices induced by different directing agents

Czech Academy of Sciences Publication Activity Database

Putz, A.-M.; Cecilia, S.; Ianasi, C.; Dudás, Z.; Székely, N. K.; Plocek, Jiří; Sfarloaga, P.; Sacarescu, L.; Almásy, L.

2015-01-01

Roč. 22, č. 2 (2015), s. 321-331 ISSN 1380-2224 Institutional support: RVO:61388980 Keywords : Mesoporous silica * MCM-41 * Dodecyl-trimethyl ammonium bromide * Hexadecyl-trimethylammonium bromide Subject RIV: CA - Inorganic Chemistry Impact factor: 1.385, year: 2015

Air emission in France. Metropolitan area persistent organic pollutants; Emissions dans l'air en France. Metropole produits organiques persistants

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-04-01

Substances and index currently in survey are: Persistent Organic Pollutants (POP): dioxines et furans (Diox), Polycyclic Aromatic Hydrocarbons (PAHs), poly-chloro-biphenyls (PCBs) and hexa-chloro-benzene (HCB). Density ratios relating to population, area, gross product, primary energy consumption, etc. Annual emissions are provided for each substance since 1990. Dates corresponding to the maximum and minimum values are also included. Results are provisional for 2001. (author)

The uranium (VI) determination method in the technological products

International Nuclear Information System (INIS)

Fursa, L.I.; Belykevich, N.A.

1994-01-01

The method includes an extraction of the uranyl nitrate by solution' hexa butyl tries amide of phosphoric acid in the hexane, a reextraction of uranium by arsenazo III solution under pH 2 and following the solution' photometry. With the purpose of excluding the emulsion' formation under uranium reextraction has been added chloroform in volume ratio to hexane 1:(3.0-7.5). tabs. 2

Mesoporous SSZ-13 zeolite prepared by a dual template method with improved performance in the methanol to Olefins reaction

NARCIS (Netherlands)

Wu, L.; Degirmenci, V.; Magusin, P.C.M.M.; Lousberg, N.J.H.G.M.; Hensen, E.J.M.

2013-01-01

Hierarchical SSZ-13 zeolites were synthesized by combining N,N,N-trimethyl-1-adamantanammonium hydroxide (TMAdOH) as the structure-directing agent for chabazite formation with mono- and diquaternary ammonium-type and organosilane mesoporogens and extensively characterized for their structural,

Crystal structures and spectroscopic properties of 2¿3 phospha-1,3-dionates and 1,3-dionates of calcium ¿ comparative studies on the 1,3-diphenyl- and 1,3-Di(tert-butyl) derivatives¿

NARCIS (Netherlands)

Becker, Gerd; Niemeyer, Mark; Mundt, Otto; Schwarz, Wolfgang; Westerhausen, Matthias; Ossberger, Manfred W.; Mayer, Peter; Nöth, Heinrich; Zhong, Zhiyuan; Dijkstra, Pieter J.; Feijen, Jan

2004-01-01

Der Wasserstoff-Metall-Austausch zwischen Dibenzoylphosphan und Calciumcarbid in Tetrahydrofuran (THF) ergibt nach Zusatz des Liganden 1, 3, 5-Trimethyl-1, 3, 5-triazinan (TMTA) den als Kokristallisat mit Benzol isolierten zweikernigen Komplex Bis[(tmta-N, N, N)calcium-bis(dibenzoylphosphanid)

Diversity and evolutionary relationship of nucleotide binding site ...

Indian Academy of Sciences (India)

PRAKASH KUMAR

site-encoding disease-resistance gene analogues in sweet potato. (Ipomoea batatas Lam.) ... terminal domain of the protein, this class of R-genes can be subdivided into TIR ... from young leaflets using the modified 2.0% (w/v) cetyl trimethyl ...

Quantitative interaction proteomics and genome-wide profiling of epigenetic histone marks and their readers

DEFF Research Database (Denmark)

Vermeulen, Michiel; Eberl, H Christian; Matarese, Filomena

2010-01-01

Trimethyl-lysine (me3) modifications on histones are the most stable epigenetic marks and they control chromatin-mediated regulation of gene expression. Here, we determine proteins that bind these marks by high-accuracy, quantitative mass spectrometry. These chromatin "readers" are assigned...

Investigations of the nuclear magnetic resonance of phosphorus compounds. XXXII. Borontrifluoride adducts of some methylenephosphoranes

Energy Technology Data Exchange (ETDEWEB)

Fluck, E; Bayha, H; Heckmann, G [Stuttgart Univ. (TH) (Germany F.R.). Inst. fuer Anorganische Chemie

1976-03-01

The synthesis of the hitherto unknown BF/sub 3/ adducts of trimethyl- and triethyl-methylenephosphorane is described. The /sup 31/P-, /sup 11/B-, /sup 19/F- and /sup 1/H-nmr spectra of these compounds are reported and interpreted.

Reduction of {sup 137}caesium contamination in wild boars by supplementing offered food with ammonium-iron-hexa-cyanoferrate; Reduktion der {sup 137}Caesium-Aktivitaet in Wildschweinen durch Zusatz von Ammonium-Eisen-Hexacyanoferrat (''Berliner Blau'') zum Kirrfutter

Energy Technology Data Exchange (ETDEWEB)

Morfeld, P. [Evonik Industries AG, Essen (Germany). Inst. fuer Epidemiologie und Risikobewertung in der Arbeitswelt (IERA); Koeln Univ. (Germany). Inst. und Poliklinik fuer Arbeitsmedizin, Umweltmedizin und Praeventionsforschung; Reddemann, J.; Schungel, P. [Landesjagdverband Bayern e.V., Feldkirchen (Germany); Kienzle, E. [Muenchen Univ., Oberschleissheim (Germany). Lehrstuhl fuer Tierernaehrung und Diaetetik

2014-06-15

This replication study investigated whether the {sup 137}caesium ({sup 137}Cs) contamination of wild boars could be relevantly reduced under field conditions by adding ammonium-iron-hexa-cyanoferrate (AFCF; Prussian blue) to the food. In 285 wild boars that had been shot in six Bavarian hunting territories during the season (November until May) between 01 November 2010 and 10 December 2011 {sup 137}Cs contamination was analysed. Thirty-five animals originated from two hunting territories in which offered food had been supplemented with 1250 mg AFCF per kilogram food. The control animals showed a mean {sup 137}Cs contamination of 522 Bq/kg lean skeletal muscle meat. Direct (univariable) comparisons of the two experimental territories with the four control territories yielded a mean reduction in {sup 137}Cs contamination due to Prussian bluefeeding by -211 Bq/kg (p < 0.001). Multivariable mo dels that took potential confounders into account (age, weight, sex, hunting date, territory) estimated the effect to be -344 Bq/kg (p < 0.05). This replication study confirmed the finding of Kienzle et al. (12) who described a statistically significant reduction in {sup 137}Cs contamination by -380 Bq/kg due to the feeding of Prussian blue in other territories. [German] Gegenstand und Ziel: Diese Replikationsstudie pruefte, ob unter Feldbedingungen die Kontamination von Wildschweinen mit {sup 137}Caesium ({sup 137}Cs) durch Zugabe vn Ammonium-Eisen-Hexacyanoferrat (AFCF, ''Berliner Blau'') zum ausgelegten Futter relevant verringert werden kann. Material und Methoden: Bei 285 Wildschweinen, die zwischen dem 01.11.2010 und dem 10.12.2011 waehrend der Jagdsaison (November bis Mai) in sechs bayerischen Jagdrevieren erlegt worden waren, erfolgte eine Analyse der {sup 137}Cs-Aktivitaet. Von diesen Tieren stammten 35 aus zwei Revieren, in denen das ausgelegte Futter mit 1250 mg AFCF/kg Futter supplementiert worden war. Ergebnisse: Die Kontrolltiere wiesen eine

Semi-robotic 6 degree of freedom positioning for intracranial high precision radiotherapy; first phantom and clinical results

International Nuclear Information System (INIS)

Wilbert, Jürgen; Guckenberger, Matthias; Polat, Bülent; Sauer, Otto; Vogele, Michael; Flentje, Michael; Sweeney, Reinhart A

2010-01-01

To introduce a novel method of patient positioning for high precision intracranial radiotherapy. An infrared(IR)-array, reproducibly attached to the patient via a vacuum-mouthpiece(vMP) and connected to the table via a 6 degree-of-freedom(DoF) mechanical arm serves as positioning and fixation system. After IR-based manual prepositioning to rough treatment position and fixation of the mechanical arm, a cone-beam CT(CBCT) is performed. A robotic 6 DoF treatment couch (HexaPOD™) then automatically corrects all remaining translations and rotations. This absolute position of infrared markers at the first fraction acts as reference for the following fractions where patients are manually prepositioned to within ± 2 mm and ± 2° of this IR reference position prior to final HexaPOD-based correction; consequently CBCT imaging is only required once at the first treatment fraction. The preclinical feasibility and attainable repositioning accuracy of this method was evaluated on a phantom and human volunteers as was the clinical efficacy on 7 pilot study patients. Phantom and volunteer manual IR-based prepositioning to within ± 2 mm and ± 2° in 6DoF was possible within a mean(± SD) of 90 ± 31 and 56 ± 22 seconds respectively. Mean phantom translational and rotational precision after 6 DoF corrections by the HexaPOD was 0.2 ± 0.2 mm and 0.7 ± 0.8° respectively. For the actual patient collective, the mean 3D vector for inter-treatment repositioning accuracy (n = 102) was 1.6 ± 0.8 mm while intra-fraction movement (n = 110) was 0.6 ± 0.4 mm. This novel semi-automatic 6DoF IR-based system has been shown to compare favourably with existing non-invasive intracranial repeat fixation systems with respect to handling, reproducibility and, more importantly, intra-fraction rigidity. Some advantages are full cranial positioning flexibility for single and fractionated IGRT treatments and possibly increased patient comfort

Semi-robotic 6 degree of freedom positioning for intracranial high precision radiotherapy; first phantom and clinical results

Directory of Open Access Journals (Sweden)

Flentje Michael

2010-05-01

Full Text Available Abstract Background To introduce a novel method of patient positioning for high precision intracranial radiotherapy. Methods An infrared(IR-array, reproducibly attached to the patient via a vacuum-mouthpiece(vMP and connected to the table via a 6 degree-of-freedom(DoF mechanical arm serves as positioning and fixation system. After IR-based manual prepositioning to rough treatment position and fixation of the mechanical arm, a cone-beam CT(CBCT is performed. A robotic 6 DoF treatment couch (HexaPOD™ then automatically corrects all remaining translations and rotations. This absolute position of infrared markers at the first fraction acts as reference for the following fractions where patients are manually prepositioned to within ± 2 mm and ± 2° of this IR reference position prior to final HexaPOD-based correction; consequently CBCT imaging is only required once at the first treatment fraction. The preclinical feasibility and attainable repositioning accuracy of this method was evaluated on a phantom and human volunteers as was the clinical efficacy on 7 pilot study patients. Results Phantom and volunteer manual IR-based prepositioning to within ± 2 mm and ± 2° in 6DoF was possible within a mean(± SD of 90 ± 31 and 56 ± 22 seconds respectively. Mean phantom translational and rotational precision after 6 DoF corrections by the HexaPOD was 0.2 ± 0.2 mm and 0.7 ± 0.8° respectively. For the actual patient collective, the mean 3D vector for inter-treatment repositioning accuracy (n = 102 was 1.6 ± 0.8 mm while intra-fraction movement (n = 110 was 0.6 ± 0.4 mm. Conclusions This novel semi-automatic 6DoF IR-based system has been shown to compare favourably with existing non-invasive intracranial repeat fixation systems with respect to handling, reproducibility and, more importantly, intra-fraction rigidity. Some advantages are full cranial positioning flexibility for single and fractionated IGRT treatments and possibly increased patient

Random amplified polymorphic DNA (RAPD) markers reveal genetic ...

African Journals Online (AJOL)

The present study evaluated genetic variability of superior bael genotypes collected from different parts of Andaman Islands, India using fruit characters and random amplified polymorphic DNA (RAPD) markers. Genomic DNA extracted from leaf material using cetyl trimethyl ammonium bromide (CTAB) method was ...

Diphtheria toxoid-containing microparticulate powder formulations for pulmonary vaccination : Preparation, characterization and evaluation in guinea pigs

NARCIS (Netherlands)

Amidi, Maryam; Pellikaan, Hubert C.; Hirschberg, Hoang; de Boerd, Anne H.; Crommelin, Daan J. A.; Hennink, Wim E.; Kersten, Gideon; Jiskoot, Wim

2007-01-01

this study, the potential of N-Trimethyl chitosan (TMC, degree of quaternization 50%) and dextran microparticles for pulmonary delivery of diphtheria toxoid (DT) was investigated. The antigen-containing microparticles were prepared by drying of an aqueous solution of polymer and DT through a

3-(2-Fluorophenylsulfinyl-2,5,7-trimethyl-1-benzofuran

Directory of Open Access Journals (Sweden)

Hong Dae Choi

2013-06-01

Full Text Available In the title compound, C17H15FO2S, the benzofuran ring system, being essentially planar, with an r.m.s. deviation from the least-squares plane of 0.009 (2 Å, makes a dihedral angle of 79.02 (5° with the plane of the 2-fluorophenyl group. In the crystal, molecules are linked by pairs of weak C—H...O hydrogen bonds into centrosymmetric dimers.

Confirmation of the reaction pathway for obtaining 1-(stearamidoethyl-2-hepta-decyl-2-i midazoline

Directory of Open Access Journals (Sweden)

Ružić Nenad Lj.

2002-01-01

Full Text Available 2-lmidazolines are components of many products, used in industry and households. 1-(Stearamidoethyl-2-heptadecyl-2-imidazoline is a surface active compound, which after quaternization with dimethyl sulfate, is used in lubricants, detergents, shampoos, softeners and cosmetics products. Due to its importance, it was essential to establish the exact reaction pathway for obtaining this compound. Diethylene triamine and stearic acid were used as the starting components. Using titrimetric analysis, and IR and 1H NMR spectros-copic analysis, as well as UV-Vis spectrophotometry it was established that the main intermediate was the 1,3-diamide bis(stearamidoethylamine. Earlier investigations conducted by some authors, using exclusively titrimetric analysis, showed that the main intermediate was the 1,2-diamide. In this paper it was proved that the assumption of these authors that salicylaldehiyde would react only with the primary and not the secondary amine groups was wrong. 1,2-Diamide is the main product of the hydrolysis of 1-(stearamido-ethyl-2-heptadecyl-2-imidazoline. It was shown, in this paper that the reaction of diethylene triamine with stearic acid in xylene at the reflux temperature, yields the salt of 1-(stearamidoethyl-2-heptadecyl-2-imidazoline and stearic acid.

Characterization of Chloroplastic Fructose 1,6-Bisphosphate Aldolases as Lysine-methylated Proteins in Plants*

Science.gov (United States)

Mininno, Morgane; Brugière, Sabine; Pautre, Virginie; Gilgen, Annabelle; Ma, Sheng; Ferro, Myriam; Tardif, Marianne; Alban, Claude; Ravanel, Stéphane

2012-01-01

In pea (Pisum sativum), the protein-lysine methyltransferase (PsLSMT) catalyzes the trimethylation of Lys-14 in the large subunit (LS) of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), the enzyme catalyzing the CO2 fixation step during photosynthesis. Homologs of PsLSMT, herein referred to as LSMT-like enzymes, are found in all plant genomes, but methylation of LS Rubisco is not universal in the plant kingdom, suggesting a species-specific protein substrate specificity of the methyltransferase. In this study, we report the biochemical characterization of the LSMT-like enzyme from Arabidopsis thaliana (AtLSMT-L), with a focus on its substrate specificity. We show that, in Arabidopsis, LS Rubisco is not naturally methylated and that the physiological substrates of AtLSMT-L are chloroplastic fructose 1,6-bisphosphate aldolase isoforms. These enzymes, which are involved in the assimilation of CO2 through the Calvin cycle and in chloroplastic glycolysis, are trimethylated at a conserved lysyl residue located close to the C terminus. Both AtLSMT-L and PsLSMT are able to methylate aldolases with similar kinetic parameters and product specificity. Thus, the divergent substrate specificity of LSMT-like enzymes from pea and Arabidopsis concerns only Rubisco. AtLSMT-L is able to interact with unmethylated Rubisco, but the complex is catalytically unproductive. Trimethylation does not modify the kinetic properties and tetrameric organization of aldolases in vitro. The identification of aldolases as methyl proteins in Arabidopsis and other species like pea suggests a role of protein lysine methylation in carbon metabolism in chloroplasts. PMID:22547063

Genome-wide RNA polymerase II profiles and RNA accumulation reveal kinetics of transcription and associated epigenetic changes during diurnal cycles.

Directory of Open Access Journals (Sweden)

Gwendal Le Martelot

Full Text Available Interactions of cell-autonomous circadian oscillators with diurnal cycles govern the temporal compartmentalization of cell physiology in mammals. To understand the transcriptional and epigenetic basis of diurnal rhythms in mouse liver genome-wide, we generated temporal DNA occupancy profiles by RNA polymerase II (Pol II as well as profiles of the histone modifications H3K4me3 and H3K36me3. We used these data to quantify the relationships of phases and amplitudes between different marks. We found that rhythmic Pol II recruitment at promoters rather than rhythmic transition from paused to productive elongation underlies diurnal gene transcription, a conclusion further supported by modeling. Moreover, Pol II occupancy preceded mRNA accumulation by 3 hours, consistent with mRNA half-lives. Both methylation marks showed that the epigenetic landscape is highly dynamic and globally remodeled during the 24-hour cycle. While promoters of transcribed genes had tri-methylated H3K4 even at their trough activity times, tri-methylation levels reached their peak, on average, 1 hour after Pol II. Meanwhile, rhythms in tri-methylation of H3K36 lagged transcription by 3 hours. Finally, modeling profiles of Pol II occupancy and mRNA accumulation identified three classes of genes: one showing rhythmicity both in transcriptional and mRNA accumulation, a second class with rhythmic transcription but flat mRNA levels, and a third with constant transcription but rhythmic mRNAs. The latter class emphasizes widespread temporally gated posttranscriptional regulation in the mouse liver.

Extraction of plutonium from lean residues by room-temperature fluoride volatility

International Nuclear Information System (INIS)

Campbell, G.M.; Foropoulos, J.; Kennedy, R.C.; Dye, B.A.; Behrens, R.G.

1990-01-01

The use of dioxygen difluoride and krypton difluoride for the recovery of plutonium from lean residues by conversion to gaseous plutonium hexa-fluoride is being investigated. The synthesis of dioxygen difluoride in practical quantity has been demonstrated. Fluorination of plutonium compounds under ideal conditions supports the contention that a viable process can be developed. Application of the method to lean plutonium residues is in the early stage of development

Synthesis of BaTiO3 powder from barium titanyl oxalate (BTO ...

Indian Academy of Sciences (India)

Unknown

the synthesis of BaTiO3 from the mixture of barium car- bonate and titanium dioxide employing microwave heat- ing. They observed that hypostoichiometric TiO2 (TiO2–x) reacted with BaCO3 in the presence of microwave field at temperature as low as 350°C to give the mixture of hexa- gonal and tetragonal forms of BaTiO3 ...

CCDC 866711: Experimental Crystal Structure Determination : catena-((mu~12~-5,5',5''-(Benzene-1,3,5-triyltris(methyleneoxy))-tri-isophthalato)-hexa-aqua-hexa-copper)

KAUST Repository

Eubank, J.F.; Nouar, F.; Luebke, Ryan; Cairns, Amy; Wojtas, L.; Al Kordi, Mohamed; Bousquet, T.; Hight, M.R.; Eckert, J.; Embs, J.P.; Georgiev, P.A.; Eddaoudi, Mohamed

2013-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 1408397: Experimental Crystal Structure Determination : catena-(tris(mu-5,5'-diazene-1,2-diyldi-isophthalato)-bis(mu-oxo)-hexa-aqua-hexa-indium hydrate)

KAUST Repository

Cairns, Amy J.; Eckert, Juergen; Wojtas, Lukasz; Thommes, Matthias; Wallacher, Dirk; Georgiev, Peter A.; Forster, Paul M.; Belmabkhout, Youssef; Ollivier, Jacques; Eddaoudi, Mohamed

2016-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 1408398: Experimental Crystal Structure Determination : catena-(tris(mu-5,5'-diazene-1,2-diyldi-isophthalato)-bis(mu-oxo)-hexa-aqua-hexa-indium hydrate)

KAUST Repository

Cairns, Amy J.; Eckert, Juergen; Wojtas, Lukasz; Thommes, Matthias; Wallacher, Dirk; Georgiev, Peter A.; Forster, Paul M.; Belmabkhout, Youssef; Ollivier, Jacques; Eddaoudi, Mohamed

2016-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

CCDC 948060: Experimental Crystal Structure Determination : catena-[bis(mu3-Oxo)-dodecakis(mu3-isonicotonato)-hexaqua-hexa-chromium-hexa-silver hexanitrate bis(tetrafluoroborate) hydrate

KAUST Repository

Schoedel, Alexander; Wojtas, Lukasz; Kelley, Stephen P.; Rogers, Robin D.; Eddaoudi, Mohamed; Zaworotko, Michael J.

2013-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Chromatographic-mass spectrometric analysis of ethanol extract of ...

African Journals Online (AJOL)

Purpose: This study analyzes the chemical composition of ethanol root extracts of Maesa perlaria var. formosana by .... obtained over a scanning range of 50 to 550 amu at 2 scans/s. .... 142.53 (2,2,6-Trimethyl-bicyclo[4.1.0]hept-1-yl)-methanol.

78 FR 55641 - Polyurethane-Type Polymers; Tolerance Exemption

Science.gov (United States)

2013-09-11

...-Type Polymers; Tolerance Exemption AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule... polymers produced by the reaction of either 1,6-hexanediisocyanate; 2,4,4-trimethyl-1,6-hexanediisocyanate... (also known as polyurethane-type polymers), when used as an inert ingredient in a pesticide chemical...

Secondary metabolites from the gorgonian Echinomuraceae splendens (Thomson and Simson)

Digital Repository Service at National Institute of Oceanography (India)

Parameswaran, P.S.; Naik, C; Govenkar, M.B.

Two xanthine derivatives, caffeine (1,3,7-trimethyl-xanthine 1) and its 2-O-methyl analog 2, N-methylpyrazole-5-carboxylic acid 3 and a tetrahydroxysterol, 1b, 3b, 5a, 6b-tetrahydro-xycholes-ane 4 have been isolated from the methanol extract...

Binary Molecular Complexes and the Nature of Molecular Association

African Journals Online (AJOL)

NJD

2004-06-15

Jun 15, 2004 ... their values in the non-interacting monomer.20 We have selected as examples of hydrogen-bonded complexes for study those formed between methanol as proton donor and trimethylamine, dimethyl ether, methyl fluoride, trimethyl phosphine, dimethyl sulphide and methyl chloride as proton acceptors.

Chemical states of molybdenum in radioactive waste glass

International Nuclear Information System (INIS)

Ishiguro, Katsuhiko; Kawanishi, Nobuo; Nagaki, Hiroshi; Naito, Aritsune

1982-01-01

In order to confirm an expectation that the chemical state of molybdenum in glass reflects the phase separation tendency of the yellow solid from the melt of borosilicate glass, simulated waste glasses were prepared, and ESCA analysis was performed using a commercially available electron spectrometer (PHI550 E) with an excitation source consisting of Mg Kα-ray. The effects of the concentration of Mo and FE 2 O 3 and the melting atmosphere (oxidizing or reducing) in which the samples were prepared on the chemical state of Mo and the solubility of MoO 3 were examined. From the observation of Mo spectra, it was shown that Mo in waste glass had several valencies, e.g., Mo(3), Mo(4), Mo(5) and Mo(6), while Mo in the yellow solid separated from the melts exhibited hexa-valent state, the peak intensity of higher valencies increased relatively with the increase of MoO 3 concentration, but the chemical state of Mo did not change remarkably around the solubility limit of MoO 3 , the melting atmosphere influenced on the Mo state in the waste glass, the peak intensity of Mo(6) increased relatively with the increasing Fe 2 O 3 concentration, and Mo in devitrified glass exhibited hexa-valent state. (Yoshitake, I.)

An orthogonal ferromagnetically coupled tetracopper(II) 2 x 2 homoleptic grid supported by micro-O4 bridges and its DFT study.

Science.gov (United States)

Roy, Somnath; Mandal, Tarak Nath; Barik, Anil Kumar; Pal, Sachindranath; Butcher, Ray J; El Fallah, Mohamed Salah; Tercero, Javier; Kar, Susanta Kumar

2007-03-28

A pyrazole based ditopic ligand (PzOAP), prepared by the reaction between 5-methylpyrazole-3-carbohydrazide and methyl ester of imino picolinic acid, reacts with Cu(NO3)2.6H2O to form a self-assembled, ferromagnetically coupled, alkoxide bridged tetranuclear homoleptic Cu(II) square grid-complex [Cu4(PzOAP)4(NO3)2] (NO3)2.4H2O (1) with a central Cu4[micro-O4] core, involving four ligand molecules. In the Cu4[micro-O4] core, out of four copper centers, two copper centers are penta-coordinated and the remaining two are hexa-coordinated. In each case of hexa-coordination, the sixth position is occupied by the nitrate ion. The complex 1 has been characterized structurally and magnetically. Although Cu-O-Cu bridge angles are too large (138-141 degrees) and Cu-Cu distances are short (4.043-4.131 A), suitable for propagation of expected antiferromagnetic exchange interactions within the grid, yet intramolecular ferromagnetic exchange (J = 5.38 cm(-1)) is present with S = 4/2 magnetic ground state. This ferromagnetic interaction is quite obvious from the bridging connections (d(x2-y2)) lying almost orthogonally between the metal centers. The exchange pathways parameters have been evaluated from density functional calculations.

Determination of lithium in organic matrix by potentiometric titration using fluoride ion selective electrode

International Nuclear Information System (INIS)

Govindan, R.; Alamelu, D.; Shah, Raju; Aggarwal, S.K.

2008-01-01

A method has been developed for the determination of lithium (Li) present in organic matrix containing hexa methylene tetramine (HMTA) and urea used in the sol-gel process for preparing lithium titanate microspheres, using fluoride ion selective electrode and potentiometric end point. Lithium is present in the wash solutions of the Sol-Gel process employed for the preparation of lithium titanate microspheres, proposed to be used in TBM (Test Blanket Module) of International Thermonuclear Experimental Reactor (ITER) project. Methods such as ICP-AES, AAS etc. used in aqueous solutions cannot be employed directly for lithium determination in organic matrix containing hexa methylene tetramine (HMTA), urea, NH 4 NO 3 , NH 4 Cl etc. A potentiometric method using a combination fluoride ion selective electrode for end point detection was developed and has been employed for lithium determination in the process streams from sol-gel process. The method is simple and rapid and an accuracy of about 0.5 % was achieved for the determination of Li in the range of 1 to 20 mg. The method is based on the complexation of Li by adding a known excess of NH 4 F solution, followed by potentiometric end point detection using fluoride ISE

Electrocatalytic activity of atomic layer deposited Pt-Ru catalysts onto N-doped carbon nanotubes

NARCIS (Netherlands)

Johansson, A.-C.; Larsen, J.V.; Verheijen, M.A.; Haugshøj, K.B.; Clausen, H.; Kessels, W.M.M.; Christensen, L.H.; Thomsen, E.V.

2014-01-01

Pt-Ru catalysts of various compositions, between 0 and 100 at.% of Ru, were deposited onto N-doped multi-walled carbon nanotubes (N-CNTs) by atomic layer deposition (ALD) at 250 C. The Pt and Ru precursors were trimethyl(methylcyclopentadienyl)platinum (MeCpPtMe3) and

Intensification of conversion of glucose to lactic acid : equilibria and kinetics for back extraction of lactic acid using trimethylamine

NARCIS (Netherlands)

Wasewar, Kailas L.; Heesink, A. Bert M.; Versteeg, Geert F.; Pangarkar, Vishwas G.

2004-01-01

Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

Intensification of conversion of glucose to lactic acid: equilibria and kinetics for back extraction of lactic acid using trimethylamine

NARCIS (Netherlands)

Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

2004-01-01

Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

SETD2 loss-of-function promotes renal cancer branched evolution through replication stress and impaired DNA repair

DEFF Research Database (Denmark)

Kanu, N.; Grönroos, E.; Martinez, P.

2015-01-01

Defining mechanisms that generate intratumour heterogeneity and branched evolution may inspire novel therapeutic approaches to limit tumour diversity and adaptation. SETD2 (Su(var), Enhancer of zeste, Trithorax-domain containing 2) trimethylates histone-3 lysine-36 (H3K36me3) at sites of active t...

From Single Atoms to Nanoparticles : Autocatalysis and Metal Aggregation in Atomic Layer Deposition of Pt on TiO2 Nanopowder

NARCIS (Netherlands)

Grillo, Fabio; Van Bui, Hao; La Zara, Damiano; Aarnink, Antonius A.I.; Kovalgin, Alexey Y.; Kooyman, Patricia; Kreutzer, Michiel T.; van Ommen, Jan Rudolf

2018-01-01

A fundamental understanding of the interplay between ligand-removal kinetics and metal aggregation during the formation of platinum nanoparticles (NPs) in atomic layer deposition of Pt on TiO2 nanopowder using trimethyl(methylcyclo-pentadienyl)platinum(IV) as the precursor and O2 as the coreactant

Structure elucidation and chemical synthesis of stigmolone, a novel type of prokaryotic pheromone.

Science.gov (United States)

Hull, W E; Berkessel, A; Plaga, W

1998-09-15

Approximately 2 micromol of a novel prokaryotic pheromone, involved in starvation-induced aggregation and formation of fruiting bodies by the myxobacterium Stigmatella aurantiaca, were isolated by a large-scale elution procedure. The pheromone was purified by HPLC, and high-resolution MS, IR, 1H-NMR, and 13C-NMR were used to identify the active substance as the hydroxy ketone 2,5, 8-trimethyl-8-hydroxy-nonan-4-one, which has been named stigmolone. The analysis was complicated by a solvent-dependent equilibrium between stigmolone and the cyclic enol-ether 3,4-dihydro-2,2, 5-trimethyl-6-(2-methylpropyl)-2H-pyran formed by intramolecular nucleophilic attack of the 8-OH group at the ketone C4 followed by loss of H2O. Both compounds were synthesized chemically, and their structures were confirmed by NMR analysis. Natural and synthetic stigmolone have the same biological activity at ca. 1 nM concentration.

Synthesis and characterization of chitosan quaternary ammonium salt and its application as drug carrier for ribavirin.

Science.gov (United States)

Li, Si-Dong; Li, Pu-Wang; Yang, Zi-Ming; Peng, Zheng; Quan, Wei-Yan; Yang, Xi-Hong; Yang, Lei; Dong, Jing-Jing

2014-11-01

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) is hydro-soluble chitosan (CS) derivative, which can be obtained by the reaction between epoxypropyl trimethyl ammonium chloride (ETA) and CS. The preparation parameters for the synthesis of HTCC were optimized by orthogonal experimental design. ETA was successfully grafted into the free amino group of CS. Grafting of ETA with CS had great effect on the crystal structure of HTCC, which was confirmed by the XRD results. HTCC displayed higher capability to form nanoparticles by crosslinking with negatively charged sodium tripolyphosphate (TPP). Ribavrin- (RIV-) loaded HTCC nanoparticles were positively charged and were spherical in shape with average particle size of 200 nm. More efficient drug encapsulation efficiency and loading capacity were obtained for HTCC in comparison with CS, however, HTCC nanoparticles displayed faster release rate due to its hydro-soluble properties. The results suggest that HTCC is a promising CS derivative for the encapsulation of hydrophilic drugs in obtaining sustained release of drugs.

Transcriptionally Active Heterochromatin in Rye B Chromosomes[W

Science.gov (United States)

Carchilan, Mariana; Delgado, Margarida; Ribeiro, Teresa; Costa-Nunes, Pedro; Caperta, Ana; Morais-Cecílio, Leonor; Jones, R. Neil; Viegas, Wanda; Houben, Andreas

2007-01-01

B chromosomes (Bs) are dispensable components of the genomes of numerous species. Thus far, there is a lack of evidence for any transcripts of Bs in plants, with the exception of some rDNA sequences. Here, we show that the Giemsa banding-positive heterochromatic subterminal domain of rye (Secale cereale) Bs undergoes decondensation during interphase. Contrary to the heterochromatic regions of A chromosomes, this domain is simultaneously marked by trimethylated H3K4 and by trimethylated H3K27, an unusual combination of apparently conflicting histone modifications. Notably, both types of B-specific high copy repeat families (E3900 and D1100) of the subterminal domain are transcriptionally active, although with different tissue type–dependent activity. No small RNAs were detected specifically for the presence of Bs. The lack of any significant open reading frame and the highly heterogeneous size of mainly polyadenylated transcripts indicate that the noncoding RNA may function as structural or catalytic RNA. PMID:17586652

Synthesis of Poly(styrene-co-butyl acrylate/Clay Nanocomposite via In Situ AGET ATRP

Directory of Open Access Journals (Sweden)

laleh Ahmadian-Alam

2012-12-01

Full Text Available Poly(styrene-co-butyl acrylate/clay nanocomposites were synthesized via in situ atom transfer radical polymerization using activators generated by electron transfer in the presence of a montmorillonite ion-exchanged with mixed surfactants of dodecyl trimethyl ammonium bromide and vinyl trimethyl ammonium chloride. The living nature of polymerization is confrmed by occurrence of narrow molecular weight distribution of the nanocomposites in which copolymers with polydispersity index of about 1.13-1.15 were obtained. Partial exfoliation of clay layers in the copolymer matrix was demonstrated by XRD patterns and further studies of TEM images. Thermogravimetric analysis (TGA results demonstrated a slight increase in the thermal stability of nanocomposites in comparison with the neat copolymer. DSC results indicated a decrease in the glass transition temperature (Tg of nanocomposites by the addition of clay content which are attributed to low molecular weights of the copolymers and weaker interactions between polymer chains. The chemical structure and composition of copolymers was identifed by 1H NMR analysis.

Ruled by Ubiquitylation: A New Order for Polycomb Recruitment

Directory of Open Access Journals (Sweden)

Yuri B. Schwartz

2014-07-01

Full Text Available Polycomb complexes are found in most cells, but they must be targeted to specific genes in specific cell types in order to regulate pluripotency and differentiation. The recruitment of Polycomb complexes to specific targets has been widely thought to occur in two steps: first, one complex, PRC2, produces histone H3 lysine 27 (H3K27 trimethylation at a specific gene, and then the PRC1 complex is recruited by its ability to bind to H3K27me3. Now, three new articles turn this model upside-down by showing that binding of a variant PRC1 complex and subsequent H2A ubiquitylation of surrounding chromatin is sufficient to trigger the recruitment of PRC2 and H3K27 trimethylation. These studies also show that ubiquitylated H2A is directly sensed by PRC2 and that ablation of PRC1-mediated H2A ubiquitylation impairs genome-wide PRC2 binding and disrupts mouse development.

The gas phase reaction of ozone with 1,3-butadiene: formation yields of some toxic products

Science.gov (United States)

Kramp, Franz; Paulson, Suzanne E.

The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product yields. In separate experiments, small quantities of 1,3,5-trimethyl benzene were added as a tracer for OH. Formation yields of acrolein of (52±7)%, 1,2-epoxy-3-butene of (3.1±0.5)% and OH radicals of (13±3)% were observed. In addition, the rate coefficient of the gas-phase reaction of ozone with 1,2-epoxy-3-butene was measured both directly and relative to propene, finding an average of (1.6±0.4)×10 -18 cm 3 molecule -1 s -1, respectively, at 296±2 K. The results are briefly discussed in terms of the effect of atmospheric processing on the toxicity of 1,3-butadiene.

Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

KAUST Repository

Tong, Guanghu

2013-05-17

The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

KAUST Repository

Tong, Guanghu; Zhu, Bo; Lee, Richmond; Yang, Wenguo; Tan, Davin; Yang, Caiyun; Han, Zhiqiang; Yan, Lin; Huang, Kuo-Wei; Jiang, Zhiyong

2013-01-01

The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

Electron Correlations and Two-Photon States in Polycyclic Aromatic Hydrocarbon Molecules: A Peculiar Role of Geometry

OpenAIRE

Aryanpour, K.; Shukla, A.; Mazumdar, S.

2013-01-01

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene and circumcoronene, all possessing $D_{6h}$ point group symmetry versus ovalene with $D_{2h}$ symmetry, within the Pariser-Parr-Pople model of interacting $\\pi$-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitat...

Crystal structure and solid-state properties of discrete hexa cationic ...

Indian Academy of Sciences (India)

Subsequently, weight loss of 33% in two stages from 242 to 691◦C can be assigned to the decomposition of triazole ligands. 3.3 Description of the crystal structure. The solid-state structure of ZnT was unambiguously determined by the single crystal X-ray diffraction tech- nique (figures 2 and 3). Compound ZnT crystallizes in.

Catalytic bleaching of cotton: molecular and macroscopic aspects

NARCIS (Netherlands)

Topalovic, T.

2007-01-01

The scope of this thesis was to investigate the possibility of low-temperature cotton bleaching employing dinuclear tri- -oxo bridged manganese(IV) complex of the ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (MnTACN) as the catalyst in the system with hydrogen peroxide. With this objective in

Spatial atmospheric atomic layer deposition of alxzn1-xo

NARCIS (Netherlands)

Illiberi, A.; Scherpenborg, R.; Wu, Y.; Roozeboom, F.; Poodt, P.

2013-01-01

The possibility of growing multicomponent oxides by spatial atmospheric atomic layer deposition has been investigated. To this end, Al xZn1-xO films have been deposited using diethyl zinc (DEZ), trimethyl aluminum (TMA), and water as Zn, Al, and O precursors, respectively. When the metal precursors

Epigenetic inactivation of Notch-Hes pathway in human B-cell acute lymphoblastic leukemia.

Science.gov (United States)

Kuang, Shao-Qing; Fang, Zhihong; Zweidler-McKay, Patrick A; Yang, Hui; Wei, Yue; Gonzalez-Cervantes, Emilio A; Boumber, Yanis; Garcia-Manero, Guillermo

2013-01-01

The Notch pathway can have both oncogenic and tumor suppressor roles, depending on cell context. For example, Notch signaling promotes T cell differentiation and is leukemogenic in T cells, whereas it inhibits early B cell differentiation and acts as a tumor suppressor in B cell leukemia where it induces growth arrest and apoptosis. The regulatory mechanisms that contribute to these opposing roles are not understood. Aberrant promoter DNA methylation and histone modifications are associated with silencing of tumor suppressor genes and have been implicated in leukemogenesis. Using methylated CpG island amplification (MCA)/DNA promoter microarray, we identified Notch3 and Hes5 as hypermethylated in human B cell acute lymphoblastic leukemia (ALL). We investigated the methylation status of other Notch pathway genes by bisulfite pyrosequencing. Notch3, JAG1, Hes2, Hes4 and Hes5 were frequently hypermethylated in B leukemia cell lines and primary B-ALL, in contrast to T-ALL cell lines and patient samples. Aberrant methylation of Notch3 and Hes5 in B-ALL was associated with gene silencing and was accompanied by decrease of H3K4 trimethylation and H3K9 acetylation and gain of H3K9 trimethylation and H3K27 trimethylation. 5-aza-2'-deoxycytidine treatment restored Hes5 expression and decreased promoter hypermethylation in most leukemia cell lines and primary B-ALL samples. Restoration of Hes5 expression by lentiviral transduction resulted in growth arrest and apoptosis in Hes5 negative B-ALL cells but not in Hes5 expressing T-ALL cells. These data suggest that epigenetic modifications are implicated in silencing of tumor suppressor of Notch/Hes pathway in B-ALL.

Backbone structure of Yersinia pestis Ail determined in micelles by NMR-restrained simulated annealing with implicit membrane solvation

International Nuclear Information System (INIS)

Marassi, Francesca M.; Ding, Yi; Schwieters, Charles D.; Tian, Ye; Yao, Yong

2015-01-01

The outer membrane protein Ail (attachment invasion locus) is a virulence factor of Yersinia pestis that mediates cell invasion, cell attachment and complement resistance. Here we describe its three-dimensional backbone structure determined in decyl-phosphocholine (DePC) micelles by NMR spectroscopy. The NMR structure was calculated using the membrane function of the implicit solvation potential, eefxPot, which we have developed to facilitate NMR structure calculations in a physically realistic environment. We show that the eefxPot force field guides the protein towards its native fold. The resulting structures provide information about the membrane-embedded global position of Ail, and have higher accuracy, higher precision and improved conformational properties, compared to the structures calculated with the standard repulsive potential

Tree Coring as an initial screening tool for typical pollutants in the subsurface

DEFF Research Database (Denmark)

Nielsen, Mette Algreen; Trapp, Stefan

2014-01-01

Previous guidelines report that tree coring is more or less useful for a variety of VOCs, such as BTEX, MTBE, trimethyl benzene, and chlorinated solvents (PCE, TCE, DCE, VC). This new guideline goes beyond the previous guidelines by including the use of a technique to screen for heavy metals, plus...

Atmospheric spatial atomic layer deposition of in-doped ZnO

NARCIS (Netherlands)

Illiberi, A.; Scherpenborg, R.; Roozeboom, F.; Poodt, P.

2014-01-01

Indium-doped zinc oxide (ZnO:In) has been grown by spatial atomic layer deposition at atmospheric pressure (spatial-ALD). Trimethyl indium (TMIn), diethyl zinc (DEZ) and deionized water have been used as In, Zn and O precursor, respectively. The metal content of the films is controlled in the range

EZH2 and BMI1 inversely correlate with prognosis and TP53 mutation in breast cancer

NARCIS (Netherlands)

Pietersen, Alexandra M.; Horlings, Hugo M.; Hauptmann, Michael; Langerod, Anita; Ajouaou, Abderrahim; Cornelissen-Steijger, Paulien; Wessels, Lodewijk F.; Jonkers, Jos; van de Vijver, Marc J.; van Lohuizen, Maarten

2008-01-01

Introduction PolycombGroup (PcG) proteins maintain gene repression through histone modifications and have been implicated in stem cell regulation and cancer. EZH2 is part of Polycomb Repressive Complex 2 (PRC2) and trimethylates H3K27. This histone mark recruits the BMI1-containing PRC1 that

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Maleic-grafted PP (MAPP) was used as compatibilizer for making PP hydrophilic. Surface modification of Na–MMT was made by using amino propyl trimethoxy silane (APS) and trimethyl amine as coupling agent with surface grafting catalyst, respectively. A fracture mechanics approach has been adopted by mode I test and ...

Purification and characterization of a gentiohexaose obtained from botryosphaeran by partial acid hydrolysis

International Nuclear Information System (INIS)

Silva, Iara Ribeiro; Monteiro, Nilson Kobori; Martinez, Paula Felippe; Izeli, Nataly Lino; Vasconcelos, Ana Flora Dalberto; Cardoso, Marilsa de Stefani; Silva, Maria de Lourdes Corradi da; Silva, Gil Valdo Jose da; Moraes, Luis Alberto Beraldo de

2008-01-01

A hexa-oligosaccharide was obtained by partial acid hydrolysis from botryosphaeran, an exopolysaccharide (EPS) β(1→3; 1→6)-D-glucan type, produced by the ascomyceteous fungus Botryosphaeria rhodina. The oligosaccharide was purified by gel filtration and charcoal-Celite column chromatography and the analysis was followed by HPAEC/ PAD. The structure was determined by NMR spectroscopy and mass spectrometry, which showed that the oligosaccharide consists of six β-D-glucopyranosyl units O-6 substituted (gentiohexaose). (author)

Binuclear new complexes of dioxouranium (VI) and thorium (IV) with some Schiff bases derived from 4,4'-diamino stilbene-2,2'-disulphonic acid-vanillin and O-vanillin

International Nuclear Information System (INIS)

Pujar, M.A.; Siddappa, K.

1992-01-01

Dioxouranium (VI) and thorium (IV) form 1:1 (metal:ligand) complexes with some Schiff bases. The complexes have been characterized through elemental analyses, conductance, UV-Visible, IR, NMR, TG data and magnetic susceptibility measurements. They are found to be dimeric with hexa or octa-coordinated arrangement around metal ion moiety. The Fsub(U-O) (mdyn A o ) and the length R UO (A o ) of U-O bond are calculated from the IR data. (author). 8 refs., 1 tab

Tay-Sachs disease preconception screening in Australia: self-knowledge of being an Ashkenazi Jew predicts carrier state better than does ancestral origin, although there is an increased risk for c.1421 + 1G > C mutation in individuals with South African heritage

OpenAIRE

Lew, Raelia; Burnett, Leslie; Proos, Anné

2011-01-01

The Australasian Community Genetics Program provided a preconception screening for Tay-Sachs disease (TSD) to 4,105 Jewish high school students in Sydney and Melbourne over the 12-year period 1995–2007. By correlating the frequencies of mutant HEXA, MIM *606869 (gene map locus 15q23-q24) alleles with subjects’ nominated ethnicity (Ashkenazi/Sephardi/Mixed) and grandparental birthplaces, we established that Ashkenazi ethnicity is a better predictor of TSD carrier status than grandparental ance...

78 FR 65561 - D-Glucopyranose, oligomeric, decyl octyl glycosides; Exemption from the Requirement of a Tolerance

Science.gov (United States)

2013-11-01

... metabolize D-glucopyranose, oligomeric, C 10 -C 16 -alkyl glycosides to water-soluble substances... polyoxyethylene polymers and fatty acids; carriers such as clay and diatomaceous earth; thickeners such as... exposure through drinking water and in residential settings, but does not include occupational exposure...

Structural basis for site-specific reading of unmodified R2 of histone H3 tail by UHRF1 PHD finger

Institute of Scientific and Technical Information of China (English)

Chengkun Wang; Jie Shen; Zhongzheng Yang; Ping Chen; Bin Zhao; Wei Hu; Wenxian Lan

2011-01-01

Dear Editor,We report two NMR complex structures of PHDUHRF1 binding to unmodified or K9 trimethylated histone tails,which clarify a controversy regarding how the binding of UHRF1 to H3 tails is mediated.Based on our structures,H3R2,not H3K9,mediates PHD binding.

Polycomb Group Protein Displacement and Gene Activation through MSK-Dependent H3K27me3S28 Phosphorylation

DEFF Research Database (Denmark)

Gehani, Simmi Suman; Agrawal-Singh, Shuchi; Dietrich, Nikolaj

2010-01-01

Epigenetic regulation of chromatin structure is essential for the expression of genes determining cellular specification and function. The Polycomb repressive complex 2 (PRC2) di- and trimethylates histone H3 on lysine 27 (H3K27me2/me3) to establish repression of specific genes in embryonic stem ...

Patterned deposition by atmospheric pressure plasma-enhanced spatial atomic layer deposition

NARCIS (Netherlands)

Poodt, P.; Kniknie, B.J.; Branca, A.; Winands, G.J.J.; Roozeboom, F.

2011-01-01

An atmospheric pressure plasma enhanced atomic layer deposition reactor has been developed, to deposit Al2O3 films from trimethyl aluminum and an He/O2 plasma. This technique can be used for 2D patterned deposition in a single in-line process by making use of switched localized plasma sources. It

Novel high band gap pendant-borylated carbazole polymers with deep HOMO levels through direct ⁺N=B^- interaction for organic photovoltaics

DEFF Research Database (Denmark)

Brandt, Rasmus G.; Sveegaard, Steffen G.; Xiao, Manjun

2016-01-01

In this communication, we investigate the direct and still conjugated intramolecular +N=B- interactions in novel high band gap borylated carbazole containing polymers, namely, poly(3,6-(N-di(2,4,6-trimethyl)-phenylboryl-carbazole)-alt- 4,8-di(5-(2-ethylhexyl)thiophene-2-yl)benzo[1,2-b: 4,5-b...

The role of salicylic acid, L-ascorbic acid and oxalic acid in promoting the oxidation of alkenes with H(2)O(2) catalysed by [Mn(IV) (2)(O)(3)(tmtacn)(2)](2+)

NARCIS (Netherlands)

de Boer, Johannes W.; Alsters, Paul L.; Meetsma, Auke; Hage, Ronald; Browne, Wesley R.; Feringa, Ben L.

2008-01-01

The role played by the additives salicylic acid, L-ascorbic acid and oxalic acid in promoting the catalytic activity of [Mn(IV) (2)(O)(3)(tmtacn)(2)](PF(6))(2) {1(PF(6))(2), where tmtacn = N, N ', N ''-trimethyl-1,4,7-triazacyclononane} in the epoxidation and cis-dihydroxylation of alkenes with

Synthesis of new heterocyclic compounds using 2-(4,7-dichloro-3,3-dimethyl-indolin-2-ylidenemalonaldehyde

Directory of Open Access Journals (Sweden)

Razieh Mohammadnejad Aghdam

2013-01-01

Full Text Available 1-(2,5-Dichlorophenylhydrazine was converted via Fischer synthesis with isopropylmethylketone into 4,7-dichloro-2,3,3-trimethyl-3H-indole. Exposure of the indolenine to the vilsmeier reagent produced amino methylene malondialdehyde which reacted with hydrazine, arylhydrazine, urea, cyanoacetamide and thiourea to give pyrazols, pyrimidones and thiopyrimidone, respectively.

Evaluation of genetic diversity in rice using simple sequence repeats ...

African Journals Online (AJOL)

The genetic diversity of 64 rice genotypes using 20 SSR primers on chromosome number 7-12 was investigated. DNA was extracted by modified cetyl trimethyl ammonium bromide (CTAB) method. The banding pattern was recorded in the form of 0-1 data sheet which was analyzed using unweighted pair group method with ...

CCDC 870534: Experimental Crystal Structure Determination : Dichloro-trimethyl-tantalum(v)

KAUST Repository

Chen, Yin; Callens, E.; Abou-Hamad, E.; Merle, N.; White, A.J.P.; Taoufik, M.; Coperet, C.; Le Roux, E.; Basset, J.-M.

2013-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

2,4,6-Trimethyl-3,5-bis[(phenylcarbonothioylsulfanylmethyl]benzyl benzenecarbodithioate

Directory of Open Access Journals (Sweden)

M. Kannan

2010-06-01

Full Text Available In the title compound C33H30S6, the three pendant methylene benzodithioate groups lie to one side of the central benzene ring in a cis-cis-cis `tripod' arrangement. The dihedral angles between the central benzene ring and the three pendant rings are 72.54 (4, 89.68 (4 and 86.74 (4°. In the crystal structure, one of the benzene rings is disordered over two orientations in a 0.559 (13:0.441 (13 ratio.

Preparation of N, N, N-trimethyl chitosan-functionalized retinoic acid ...

African Journals Online (AJOL)

nanocarrier (TR-SLNs) with enhanced anti-cancer activity. ... Retinoic acid (RA), a derivative of vitamin A, is a potential ... intravenous (i.v.) administration; therefore, RA ... °C. Preparation of TMC. TMC was synthesized by reductive methylation.

N,N,N′-Trimethyl-N′′-(4-nitrophenyl-N′-phenylguanidine

Directory of Open Access Journals (Sweden)

Ioannis Tiritiris

2014-05-01

Full Text Available The C—N bond lengths in the guanidine unit of the title compound, C16H18N4O2, are 1.298 (2, 1.353 (2 and 1.401 (3 Å, indicating double- and single-bond character. The N—C—N angles are 115.81 (16, 118.90 (18 and 125.16 (18°, showing a deviation of the CN3 plane from an ideal trigonal–planar geometry. In the crystal, C—H...O hydrogen bonds are observed between the methyl- and aromatic-H atoms and nitro-O atoms. One H atom of the phenyl ring and of the NMe2 group associate with the O atoms of the nitro group, giving chains along the a- and b-axis directions. Cross-linking of these two chains results in a two-dimensional network along bc.

Preparation of N, N, N-trimethyl chitosan-functionalized retinoic acid ...

African Journals Online (AJOL)

encapsulated solid lipid nanoparticles for the effective treatment of glioma. Methods: Retinoic acid-loaded solid lipid nanoparticles (R-SLNs) were prepared using homogenization followed by sonication. R-SLN surfaces were functionalized electrostatically ...

Characteristics of poly- and mono-crystalline BeO and SiO{sub 2} as thermal and cold neutron filters

Energy Technology Data Exchange (ETDEWEB)

Adib, M.; Habib, N. [Reactor Physics Department, NRC, Atomic Energy Authority, Cairo (Egypt); Bashter, I.I. [Physics Department, Faculty of Science, Zagazig University (Egypt); Morcos, H.N.; El-Mesiry, M.S. [Reactor Physics Department, NRC, Atomic Energy Authority, Cairo (Egypt); Mansy, M.S., E-mail: drmohamedmansy88@hotmail.com [Reactor Physics Department, NRC, Atomic Energy Authority, Cairo (Egypt)

2015-09-01

Highlights: • Neutron filtering features of BeO and SiO{sub 2} poly- and mono-crystals. • Calculations of the cold and thermal neutron cross sections and transmission with the code “HEXA-FILTERS”. • Optimal mosaic spread, thicknesses and cutting planes for BeO and SiO{sub 2} mono-crystals. - Abstract: A simple model along with a computer code “HEXA-FILTERS” is used to carry out the calculation of the total cross-sections of BeO and SiO{sub 2} having poly or mono-crystalline form as a function of neutron wavelength at room (R.T.) and liquid nitrogen (L.N.) temperatures. An overall agreement is indicated between the calculated neutron cross-sections and experimental data. Calculation shows that 25 cm thick of polycrystalline BeO cooled at liquid nitrogen temperature was found to be a good filter for neutron wavelengths longer than 0.46 nm. While, 50 cm of SiO{sub 2}, with much less transmission, for neutrons with wavelengths longer than 0.85 nm. It was also found that 10 cm of BeO and 15 cm SiO{sub 2} thick mono-crystals cut along their (0 0 2) plane, with 0.5° FWHM on mosaic spread and cooled at L.N., are a good thermal neutron filter, with high effect-to-noise ratio.

Terminal elimination half-lives of the brominated flame retardants TBBPA, HBCD, and lower brominated PBDEs in humans

Energy Technology Data Exchange (ETDEWEB)

Geyer, H.J.; Schramm, K.W.; Feicht, E.A.; Fried, K.W.; Henkelmann, B.; Lenoir, D. [GSF-National Research Center, Institute of Ecological Chemistry, Neuherberg (Germany); Darnerud, P.O.; Aune, M. [Swedish National Food Administration, Uppsala (Sweden); Schmid, P. [Swiss Federal Laboratories for Materials Testing and Research, Laboratory of Organic Chemistry, EMPA Duebendorf (Switzerland); McDonald, T.A. [Office of Environmental Health Assessment, California EPA, Oakland, CA (United States)

2004-09-15

Brominated flame retardants (BFRs) are widely used in polymers and textiles and applied in electronic equipment, construction materials, and furniture for the purpose of fire prevention. BFRs with the highest production volume are tetrabromobisphenol A (TBBPA), 1,2,5,6,9,10- hexabromocyclododecanes (HBCDs: {alpha}-HBCD + {beta}-HBCD + {gamma}-HBCD), and polybrominated diphenyl ethers (PBDEs). Several BFRs are highly lipophilic persistent organic pollutants (POPs) which have been identified in the aquatic and terrestrial environment including wildlife and humans. In exposed organisms including humans toxic effects, bioaccumulation, metabolism, and pharmacokinetics (especially half-life t{sub 1/2}) are important criterions in the hazard assessment. The aim of the present study was to estimate the terminal elimination half-lives (t{sub 1/2H}) of the main BFRs from the whole body (also named body-burden half-life) and/or from the adipose tissue (fat) of adult humans. The t{sub 1/2H} data for the following BFRs were evaluated: TBBPA, HBCD, 2,2',4,4'- tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentaBDE (BDE-99), 2,2',4,4',6-pentaBDE (BDE- 100), 2,2',4,4',5,5'-hexaBDE (BDE-153), and 2,2',4,4',5,6-hexaBDE (BDE-154).

Current status and future prospects of uranium resources

International Nuclear Information System (INIS)

Kuronuma, Chosuke

1997-01-01

Uranium is contained in various things in natural world, for example, 3 ppm in granite and 3x10 -3 ppm in seawater. Uranium exists in the state of tetra, penta and hexa-valence in nature, and in oxidizing environment, it exists as uranyl radical of hexa-valence, forms soluble complexes, and easily moves with water. In reducing environment, it becomes insoluble state of tetra-valence and precipitates. This property of uranium is deeply related to the way of forming the deposit, and it is explained. The uranium resources of the recovery cost being 80 dollars per kg U or less are 2,120,000 t, and 60% of the total exists in Australia, Kazakstan and Canada. The cumulative production of uranium in the world from 1945 to 1995 was 1,810,000 t. Of the total production, 875,000 t was used for civil purpose, and 750,000 t was used for military purpose. The uranium deposits in Canada are very high quality, and produce 1/3 of the world uranium production. There are the inventories of 150,000-200,000 t U. The diversion of military high enriched uranium to civil purpose is reported. The state of uranium market, the prospect of demand and supply of uranium, and the exploration and development of uranium resources are described. (K.I.)

A mass balance of tri-hexabrominated diphenyl ethers in lactating cows.

Science.gov (United States)

Kierkegaard, Amelie; De Wit, Cynthia A; Asplund, Lillemor; McLachlan, Michael S; Thomas, Gareth O; Sweetman, Andrew J; Jones, Kevin C

2009-04-01

Beef and dairy products can be important vectors of human exposure to polybrominated diphenylethers (BDEs), and hence an understanding of BDE transfer from feed to cows' milk and tissue is important for BDE exposure assessment The fate of tri- to hexaBDEs in lactating cows exposed to a naturally contaminated diet was studied by analyzing feed, feces, and milk samples from a mass balance study. Tissue distribution was studied in one cowslaughtered afterthe experiment The carryover rates from feed to milk ranged from 0.15 to 0.35 for the major congeners. Lower values were observed for several of the tetrabrominated congeners, and this was attributed to metabolism. The dietary absorption efficiency decreased with increasing octanol-water partition coefficient of the BDE congener. The absorption behavior was consistent with a model based on chemical lipophilicity, but agreed less well with a model based on effective molecular diameter, and it violated Lipinski's "rule of 5". The lipid normalized concentrations were similar in all tissues analyzed including liver and milk, suggesting that tissue distribution is governed by partitioning into lipids. Overall, the behavior of the tri- to hexaBDEs was consistent with that observed for other classes of halogenated aromatic contaminants such as PCBs and PCDD/Fs, but it differed markedly from the behavior of the hepta- decaBDEs.

Quantitative proteomic profiling for clarification of the crucial roles of lysosomes in microbial infections.

Science.gov (United States)

Xu, Benhong; Gao, Yanpan; Zhan, Shaohua; Ge, Wei

2017-07-01

Lysosomes play vital roles in both innate and adaptive immunity. It is widely accepted that lysosomes do not function exclusively as a digestive organelle. It is also involved in the process of immune cells against pathogens. However, the changes in the lysosomal proteome caused by infection with various microbes are still largely unknown, and our understanding of the proteome of the purified lysosome is another obstacle that needs to be resolved. Here, we performed a proteomic study on lysosomes enriched from THP1 cells after infection with Listeria monocytogenes (L.m), Herpes Simplex Virus 1 (HSV-1) and Vesicular Stomatitis Virus (VSV). In combination with the gene ontology (GO) analysis, we identified 284 lysosomal-related proteins from a total of 4560 proteins. We also constructed the protein-protein interaction networks for the differentially expressed proteins and revealed the core lysosomal proteins, including SRC in the L. m treated group, SRC, GLB1, HEXA and HEXB in the HSV-1 treated group and GLB1, CTSA, CTSB, HEXA and HEXB in the VSV treated group, which are involved in responding to diverse microbial infections. This study not only reveals variable lysosome responses depending on the bacterial or virus infection, but also provides the evidence based on which we propose a novel approach to proteome research for investigation of the function of the enriched organelles. Copyright © 2017 Elsevier Ltd. All rights reserved.

CCDC 866713: Experimental Crystal Structure Determination : catena-(bis(mu~12~-5,5',5''-(1,3,5-benzenetriyltris(methyleneoxy))-tris(1,3-benzenedicarboxylato))-hexa-aqua-hexa-cobalt)

KAUST Repository

Eubank, J.F.; Nouar, F.; Luebke, Ryan; Cairns, Amy; Wojtas, L.; Al Kordi, Mohamed; Bousquet, T.; Hight, M.R.; Eckert, J.; Embs, J.P.; Georgiev, P.A.; Eddaoudi, Mohamed

2013-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Epigenetic inactivation of Notch-Hes pathway in human B-cell acute lymphoblastic leukemia.

Directory of Open Access Journals (Sweden)

Shao-Qing Kuang

Full Text Available The Notch pathway can have both oncogenic and tumor suppressor roles, depending on cell context. For example, Notch signaling promotes T cell differentiation and is leukemogenic in T cells, whereas it inhibits early B cell differentiation and acts as a tumor suppressor in B cell leukemia where it induces growth arrest and apoptosis. The regulatory mechanisms that contribute to these opposing roles are not understood. Aberrant promoter DNA methylation and histone modifications are associated with silencing of tumor suppressor genes and have been implicated in leukemogenesis. Using methylated CpG island amplification (MCA/DNA promoter microarray, we identified Notch3 and Hes5 as hypermethylated in human B cell acute lymphoblastic leukemia (ALL. We investigated the methylation status of other Notch pathway genes by bisulfite pyrosequencing. Notch3, JAG1, Hes2, Hes4 and Hes5 were frequently hypermethylated in B leukemia cell lines and primary B-ALL, in contrast to T-ALL cell lines and patient samples. Aberrant methylation of Notch3 and Hes5 in B-ALL was associated with gene silencing and was accompanied by decrease of H3K4 trimethylation and H3K9 acetylation and gain of H3K9 trimethylation and H3K27 trimethylation. 5-aza-2'-deoxycytidine treatment restored Hes5 expression and decreased promoter hypermethylation in most leukemia cell lines and primary B-ALL samples. Restoration of Hes5 expression by lentiviral transduction resulted in growth arrest and apoptosis in Hes5 negative B-ALL cells but not in Hes5 expressing T-ALL cells. These data suggest that epigenetic modifications are implicated in silencing of tumor suppressor of Notch/Hes pathway in B-ALL.

The KDM₅ family is required for activation of pro-proliferative cell cycle genes during adipocyte differentiation

DEFF Research Database (Denmark)

Brier, Ann-Sofie B; Loft, Anne; Madsen, Jesper G S

2017-01-01

The KDM5 family of histone demethylases removes the H3K4 tri-methylation (H3K4me3) mark frequently found at promoter regions of actively transcribed genes and is therefore generally considered to contribute to corepression. In this study, we show that knockdown (KD) of all expressed members of th...

1,2- and 1,3-dihydroxylated and hydroxynitrogenated monoterpenes as chiral ligands in the asymmetric reformatsky reaction

International Nuclear Information System (INIS)

Ribeiro, Carlos Magno R.; Morita, Cristina M.; Maia, Monica P.

2008-01-01

This study describes the use of three (-)-α-pinene derivatives, one diol-1,2 [(-)- (1R, 2R, 3S, 5R)-2,6,6-trimethylbicyclo[3.1.1]heptane-2,3-diol 4] and two pyridine-hydroxy derivatives [(+)-(1R,2S,3R,5S)-2,6,6- trimethyl-3-(2-pyridinylmethyl)bicyclo[3.1.1]heptane-3-ol 7 and (-)-(1R,2S,3R,5S)-2,6,6-trimethyl-3-[2-(2-pyridinyl) ethyl]bicyclo[3.1.1]heptane-3-ol 8]; one diol-1,3 [(-)-(1S,2R,5S)-2-(1-hydroxy-1-methylethyl)-5-methylcyclohexanol 5] derived from (+)-isopulegol 2 and one diol-1,3 [(+)-(1R,2R,5R)-2-(1-hydroxy-1-methylethyl)-5-methylcyclohexanol 6] derived from (+)-neoisopulegol 3, as ligands in the asymmetric Reformatsky reaction. The best enantiomeric excess of β-hydroxy ester obtained in the Reformatsky asymmetric reaction was 18% using ligand 6, and the chemical yield of the reactions was 65% on average. (author)

Biotransformation of 1,8-cineole by solid-state fermentation of Eucalyptus waste from the essential oil industry using Pleurotus ostreatus and Favolus tenuiculus.

Science.gov (United States)

Omarini, Alejandra; Dambolena, José Sebastián; Lucini, Enrique; Jaramillo Mejía, Santiago; Albertó, Edgardo; Zygadlo, Julio A

2016-03-01

Biotechnological conversion of low-cost agro-industrial by-products, such as industrial waste or terpenes from the distillation of essential oils from plants into more valuable oxygenated derivatives, can be achieved by using microbial cells or enzymes. In Argentina, the essential oil industry produces several tons of waste each year that could be used as raw materials in the production of industrially relevant and value-added compounds. In this study, 1,8-cineole, one of the components remaining in the spent leaves of the Eucalyptus cinerea waste, was transformed by solid-state fermentation (SSF) using the two edible mushrooms Pleurotus ostreatus and Favolus tenuiculus. As a result, two new oxygenated derivatives of 1,8-cineole were identified: 1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-ol and 1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-one. Additionally, changes in the relative percentages of other aroma compounds present in the substrate were observed during SSF. Both fungal strains have the ability to produce aroma compounds with potential applications in the food and pharmaceutical industries.

Regulation of DU145 prostate cancer cell growth by Scm-like with four mbt domains 2.

Science.gov (United States)

Lee, Kwanghyun; Na, Wonho; Maeng, Je-Heon; Wu, Hongjin; Ju, Bong-Gun

2013-03-01

Mammalian SFMBTs have been considered to be polycomb group repressors. However, molecular mechanisms underlying mammalian SFMBTs-mediated gene regulation and their biological function have not been characterized. In the present study, we identified YY1 and methylated histones as interacting proteins of human SFMBT2. We also found that human SFMBT2 binds preferentially to methylated histone H3 and H4 that are associated with transcriptional repression. Using DU145 prostate cancer cells as a model, we showed that SFMBT2 has a transcriptional repression activity on HOXB13 gene expression. In addition, occupancy of SFMBT2 coincided with enrichment of diand tri-methylated H3K9 and H4K20 as well as tri-methylated H3K27 at the HOXB13 gene promoter. When SFMBT2 was depleted by siRNA in DU145 prostate cancer cells, significant up-regulation of HOXB13 gene expression and decreased cell growth were observed. Collectively, our findings indicate that human SFMBT2 may regulate cell growth via epigenetic regulation of HOXB13 gene expression in DU145 prostate cancer cells.

FvSet2 regulates fungal growth, pathogenicity, and secondary metabolism in Fusarium verticillioides.

Science.gov (United States)

Gu, Qin; Wang, Zhenzhong; Sun, Xiao; Ji, Tiantian; Huang, Hai; Yang, Yang; Zhang, Hao; Tahir, Hafiz Abdul Samad; Wu, Liming; Wu, Huijun; Gao, Xuewen

2017-10-01

Histone H3 lysine 36 methylation (H3K36me) is generally associated with activation of gene expression in most eukaryotic cells. However, the function of H3K36me in filamentous fungi is largely unknown. Set2 is the sole lysine histone methyltransferase (KHMTase) enzyme responsible for the methylation of H3K36 in Saccharomyces cerevisiae. In the current study, we identified a single ortholog of S. cerevisiae Set2 in Fusarium verticillioides. We report that FvSet2 is responsible for the trimethylation of H3K36 (H3K36me3). The FvSET2 deletion mutant (ΔFvSet2) showed significant defects in vegetative growth, FB 1 biosynthesis, pigmentation, and fungal virulence. Furthermore, trimethylation of H3K36 was found to be important for active transcription of genes involved in FB 1 and bikaverin biosyntheses. These data indicate that FvSet2 plays an important role in the regulation of secondary metabolism, vegetative growth and fungal virulence in F. verticillioides. Copyright © 2017 Elsevier Inc. All rights reserved.

Epigenetic regulation of facultative heterochromatinisation in Planococcus citri via the Me(3)K9H3-HP1-Me(3)K20H4 pathway.

Science.gov (United States)

Bongiorni, Silvia; Pasqualini, Barbara; Taranta, Monia; Singh, Prim B; Prantera, Giorgio

2007-03-15

Using RNA interference (RNAi) we have conducted a functional analysis of the HP1-like chromobox gene pchet2 during embryogenesis of the mealybug Planococcus citri. Knocking down pchet2 expression results in decondensation of the male-specific chromocenter that normally arises from the developmentally-regulated facultative heterochromatinisation of the paternal chromosome complement. Together with the disappearance of the chromocenter the staining levels of two associated histone modifications, tri-methylated lysine 9 of histone H3 [Me(3)K9H3] and tri-methylated lysine 20 of histone H4 [Me(3)K20H4], are reduced to undetectable levels. Embryos treated with double-stranded RNA (dsRNA) targeting pchet2 also exhibit chromosome abnormalities, such as aberrant chromosome condensation, and also the presence of metaphases that contain 'lagging' chromosomes. We conclude that PCHET2 regulates chromosome behavior during metaphase and is a crucial component of a Me(3)K9H3-HP1-Me(3)K20H4 pathway involved in the facultative heterochromatinisation of the (imprinted) paternal chromosome set.

STABILIZATION OF UNUSUAL SUBSTRATE COORDINATION MODES IN DINUCLEAR MACROCYCLIC COMPLEXES

Directory of Open Access Journals (Sweden)

Vasile Lozan

2010-06-01

Full Text Available The steric protection offered by the macrobinucleating hexaazaditiophenolate ligand (L allows for the preparation of the first stable dinuclear nickel(II borohydride bridged complex, which reacts rapidly with elemental sulphur producing a tetranuclear nickel(II complex [{(LNi2}2(μ-S6]2+ bearing a helical μ4-hexa- sulfide ligand. The [(LCoII 2]2+ fragment have been able to trap a monomethyl orthomolybdate in the binding pocket. Unusual coordination modes of substrate in dinuclear macrocyclic compounds was demonstrated.

Number of nucleoli in diploids and polyploids of the genus Achillea L.

Directory of Open Access Journals (Sweden)

Janina Dąbrowska

2014-01-01

Full Text Available Nucleoli were counted in 9228 interphase nuclei of the apical root meristem of 40 Achillea L. taxa (di-, tetra-. hexa- and octoploids. It was established that the distribution of nucleoli number in an interphase nucleus can be used as a rough practical indicator to distinguish between diploids and polyploids. The highest number of nucleoli (12 was found in an octoploid Achillea pannonica, but only in a small percentage of the nuclei (0.3% out of 283 nuclei.

Internal energy deposition with silicon nanoparticle-assisted laser desorption/ionization (SPALDI) mass spectrometry

Science.gov (United States)

Dagan, Shai; Hua, Yimin; Boday, Dylan J.; Somogyi, Arpad; Wysocki, Ronald J.; Wysocki, Vicki H.

2009-06-01

The use of silicon nanoparticles for laser desorption/ionization (LDI) is a new appealing matrix-less approach for the selective and sensitive mass spectrometry of small molecules in MALDI instruments. Chemically modified silicon nanoparticles (30 nm) were previously found to require very low laser fluence in order to induce efficient LDI, which raised the question of internal energy deposition processes in that system. Here we report a comparative study of internal energy deposition from silicon nanoparticles to previously explored benzylpyridinium (BP) model compounds during LDI experiments. The internal energy deposition in silicon nanoparticle-assisted laser desorption/ionization (SPALDI) with different fluorinated linear chain modifiers (decyl, hexyl and propyl) was compared to LDI from untreated silicon nanoparticles and from the organic matrix, [alpha]-cyano-4-hydroxycinnamic acid (CHCA). The energy deposition to internal vibrational modes was evaluated by molecular ion survival curves and indicated that the ions produced by SPALDI have an internal energy threshold of 2.8-3.7 eV. This is slightly lower than the internal energy induced using the organic CHCA matrix, with similar molecular survival curves as previously reported for LDI off silicon nanowires. However, the internal energy associated with desorption/ionization from the silicon nanoparticles is significantly lower than that reported for desorption/ionization on silicon (DIOS). The measured survival yields in SPALDI gradually decrease with increasing laser fluence, contrary to reported results for silicon nanowires. The effect of modification of the silicon particle surface with semifluorinated linear chain silanes, including fluorinated decyl (C10), fluorinated hexyl (C6) and fluorinated propyl (C3) was explored too. The internal energy deposited increased with a decrease in the length of the modifier alkyl chain. Unmodified silicon particles exhibited the highest analyte internal energy

Multifunctional Ultra-High Vacuum Apparatus for Studies of the Interactions of Chemical Warfare Agents on Complex Surfaces

Science.gov (United States)

2014-01-02

How- ever, the complete absence of trace amounts of CWAs from the system is never guaranteed. Therefore, prior to venting the chamber and opening a...Gay, A. J. McFarlan, and B. A. Morrow, “Trimethyl phosphite ad- sorbed on silica - An NMR and infrared study,” J. Phys. Chem. 95(3), 1360–1368 (1991

Simultaneous precipitation of the carbonato complexes of uranium and plutonium by cationic surfactants

International Nuclear Information System (INIS)

Heckmann, K.; Strnad, J.

1990-01-01

Concerning the simultaneous precipitation of U and Pu or Th, preliminary experiments were made with various alkyl pyridinium salts and alkyl trimethyl ammonium salts to determine their precipitation properties with regard to carbonato and hydroxo complexes. The first experiments were made with cetyl pyridinium nitrate, with Th and U being precipitated from solutions with different carbonate concentrations. (DG) [de

TALE-directed local modulation of H3K9 methylation shapes exon recognition

Czech Academy of Sciences Publication Activity Database

Bieberstein, Nicole; Kozáková, Eva; Huranová, Martina; Thakur, P.K.; Krchňáková, Zuzana; Krausová, Michaela; Oesterreich, F.C.; Staněk, David

2016-01-01

Roč. 6, jaro (2016), č. článku 29961. ISSN 2045-2322 R&D Projects: GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:68378050 Keywords : histone h3 * human genome * efficient design * chromatin * methyltransferase * transcription * trimethylation * identification * recruitment * annotation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.259, year: 2016

Structural Basis of Histone Demethylase KDM6B Histone 3 Lysine 27 Specificity

DEFF Research Database (Denmark)

Jones, Sarah E; Olsen, Lars; Gajhede, Michael

2018-01-01

KDM subfamily 6 enzymes KDM6A and KDM6B specifically catalyze demethylation of di- and trimethylated lysine on histone 3 lysine 27 (H3K27me3/2) and play an important role in repression of developmental genes. Despite identical amino acid sequence in the immediate surroundings of H3K9me3/2 (ARKS...

Total synthesis of (3S, 5R, 3'S, 5'R)-capsorubin

International Nuclear Information System (INIS)

Frederico, Daniel; Constantino, Mauricio G.; Donate, Paulo M.

2009-01-01

The total synthesis of enantiomerically enriched (3S, 5R, 3'S, 5'R)-capsorubin (1) by aldol condensation of (1R, 4S)-1-(4-hydroxy-1,2,2-trimethyl-cyclopentyl)ethanone (2a) and crocetindial (3) is described. An alternative, short eight-step synthesis of the optically active compound 2a (ee 89%) is also reported. (author)

Apparent and partial molar volumes of long-chain alkyldimethylbenzylammonium chlorides and bromides in aqueous solutions at T=15 deg. C and T=25 deg. C

International Nuclear Information System (INIS)

Gonzalez-Perez, A.; Ruso, J.M.; Nimo, J.; Rodriguez, J.R.

2003-01-01

Density measurements of dodecyl- (C 12 DBACl), tetradecyl- (C 14 DBACl), hexadecyldimethylbenzylammonium chloride (C 16 DBACl) and of decyl- (C 10 DBABr) and dodecyldimethylbenzylammonium bromide (C 12 DBABr) in aqueous solutions at T=15 deg. C and T=25 deg. C have been carried out. From these results, apparent and partial molar volumes were calculated. Positive deviations from the Debye-Hueckel limiting law provide evidence for limited association at concentrations below the critical micelle concentration. The change of the apparent molar volume upon micellization was calculated. The relevant parameters have been presented in function of the alkyl chain length. Apparent molar volumes of the present compounds in the micellar phase, V phi m , and the change upon micellization, ΔV phi m , have been discussed in terms of temperature and type of counterion

On the critical temperature, normal boiling point, and vapor pressure of ionic liquids.

Science.gov (United States)

Rebelo, Luis P N; Canongia Lopes, José N; Esperança, José M S S; Filipe, Eduardo

2005-04-07

One-stage, reduced-pressure distillations at moderate temperature of 1-decyl- and 1-dodecyl-3-methylimidazolium bistriflilamide ([Ntf(2)](-)) ionic liquids (ILs) have been performed. These liquid-vapor equilibria can be understood in light of predictions for normal boiling points of ILs. The predictions are based on experimental surface tension and density data, which are used to estimate the critical points of several ILs and their corresponding normal boiling temperatures. In contrast to the situation found for relatively unstable ILs at high-temperature such as those containing [BF(4)](-) or [PF(6)](-) anions, [Ntf(2)](-)-based ILs constitute a promising class in which reliable, accurate vapor pressure measurements can in principle be performed. This property is paramount for assisting in the development and testing of accurate molecular models.

Two distinct metacommunities characterize the gut microbiota in Crohn's disease patients

DEFF Research Database (Denmark)

He, Qing; Gao, Yuan; Jie, Zhuye

2017-01-01

The inflammatory intestinal disorder Crohn's disease (CD) has become a health challenge worldwide. The gut microbiota closely interacts with the host immune system, but its functional impact in CD is unclear. Except for studies on a small number of CD patients, analyses of the gut microbiota in CD......). Based on signature taxa, CD microbiotas clustered into two distinct metacommunities indicating individual variability in CD microbiome structure. Metacommunity-specific functional shifts in CD showed enrichment in producers of the pro-inflammatory hexa-acylated lipopolysaccharide variant and a reduction...

CCDC 831219: Experimental Crystal Structure Determination : catena-(bis(mu~12~-2,4,6-tris(3,5-Dicarboxylatophenylamino)-1,3,5-triazine)-hexa-aqua-hexa-copper unknown solvate)

KAUST Repository

Li, Baiyan; Zhang, Zhijuan; Li, Yi; Yao, Kexin; Zhu, Yihan; Deng, Zhiyong; Yang, Fen; Zhou, Xiaojing; Li, Guanghua; Wu, Haohan; Nijem, N.; Chabal, Y.J.; Lai, Zhiping; Han, Yu; Shi, Zhan; Feng, Shouhua; Li, Jing

2012-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Interaction of bentonite with dodecyl-benzyl-dimethylammonium bromide and N(1-(ethoxy carbonyl)penta-decyl)trimethylammonium bromide

Czech Academy of Sciences Publication Activity Database

Kalousová, J.; Votinský, J.; Beneš, Ludvík; Melánová, Klára; Zima, Vítězslav

1998-01-01

Roč. 4, - (1998), s. 65-73 ISSN 1211-5541 R&D Projects: GA ČR GA203/97/1010; GA AV ČR KSK2050602 Grant - others:Klíčový projekt AV ČR(CZ) No.12 Institutional research plan: CEZ:MSM 253100101; CEZ:AV0Z4050913 Subject RIV: CA - Inorganic Chemistry

76 FR 6342 - n-Octyl Alcohol and n-Decyl Alcohol; Exemption From the Requirement of a Tolerance

Science.gov (United States)

2011-02-04

... produce sensitization in guinea pigs. A 90-day dermal toxicity study in rats with fatty alcohol blend (56... pesticide manufacturer. Potentially affected entities may include, but are not limited to: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing (NAICS code 311). Pesticide...

Magnetoactive elastomeric composites: Cure, tensile, electrical and ...

Indian Academy of Sciences (India)

M/s Godrej Soap Ltd, India. N-(1,3-dimethylbutyl)-N-phenyl-P-phenylenediamene M/s Bayer India. 1,2-Dihydro-2,2,4-trimethyl quinoline. M/s Bayer India. Carbon black, FEF N 550. M/s Philips Carbon Black Ltd, Kochi. Carbon black, HAF N 330. M/s Philips Carbon Black Ltd, Kochi. Lead oxide (red lead). M/s Glaxo, Mumbai.

Undergraduate Analytical Chemistry Experiment: The Determination of Formation Constants for Acetate and Mono-and Dichloroacetate Salts of Primary, Secondary, and Tertiary Methyl-and Ethylamines

Science.gov (United States)

D'Amelia, Ronald P.; Chiang, Stephanie; Pollut, Stephanie; Nirode, William F.

2014-01-01

The formation and the hydrolysis of organic salts produced by the titration of a 0.1 M solution of the following amines: methyl-, dimethyl-, trimethyl-, ethyl-, diethyl-, and triethylamine with a 0.1 M solution of acetic, chloroacetic, and dichloracetic acids are studied. The pK[subscript b] of the amine and the pH at the end point were determined…

Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

International Nuclear Information System (INIS)

King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T.; Tuna, Floriana; McInnes, Eric J.L.

2013-01-01

Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). [de

Time-trends and congener profiles of PBDEs and PCBs in California peregrine falcons (Falco peregrinus).

Science.gov (United States)

Park, June-Soo; Holden, Arthur; Chu, Vivian; Kim, Michele; Rhee, Alexandra; Patel, Puja; Shi, Yating; Linthicum, Janet; Walton, Brian J; McKeown, Karen; Jewell, Nicholas P; Hooper, Kim

2009-12-01

High levels (microg/g lw) of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in peregrine falcon eggs from California (n = 90 eggs from 52 birds, 38 nest sites, collected 1986-2007, SigmaPBDEs median = 4.53, range = 0.08-53.1). Over the past 22 years, PBDE levels more than tripled each decade in the eggs, whereas PCB levels had no significant changes. PBDE levels were highest in eggs from major California cities ("Big Cities"), whereas PCBs showed no difference across the regions. For PBDEs, Big City eggs had markedly different patterns from Coastal eggs: BDE-209 and the higher brominated PBDEs (hexa-nona) were dominant congeners in Big City eggs, while BDE-47 and -99 were dominant in Coastal eggs. In many of the birds that gave multiple eggs over time ("time series"), PBDE patterns changed over time: the high proportions of BDE-209 and higher brominated PBDEs (short half-lives) in young birds contrasted with increasingly higher proportions of BDE-153 (long half-life) and other lower brominated PBDEs as the birds aged. These data are consistent with metabolic debromination of BDE-209 (t(1/2) = 1-2 weeks) to the lower brominated PBDEs, with accumulation over time of BDE-153 (t(1/2) = 3-4 years). In contrast, PCB patterns showed no differences by locations, and did not change over time. Diet (prey birds) may explain the urban PBDE pattern, as the patterns in urban pigeons and peregrines were similar, with high proportions of BDE-209 and the higher-brominated PBDEs. Also, our prey data (feathers from peregrine nests) showed urban peregrines having a higher proportion (>2 fold) of granivorous/opportunistic birds (e.g., "introduced feral" pigeons, mourning doves, starlings) in their diet than coastal peregrines. In summary, these data indicate that BDE-209 exits consumer products as an environmental contaminant to be taken up by wildlife (particularly in urban locations), and undergoes metabolic debromination to the banned lower

Mechanistic insights into dioxygen activation, oxygen atom exchange and substrate epoxidation by AsqJ dioxygenase from quantum mechanical/molecular mechanical calculations.

Science.gov (United States)

Song, Xudan; Lu, Jiarui; Lai, Wenzhen

2017-08-02

Herein, we use in-protein quantum mechanical/molecular mechanical (QM/MM) calculations to elucidate the mechanism of dioxygen activation, oxygen atom exchange and substrate epoxidation processes by AsqJ, an Fe II /α-ketoglutarate-dependent dioxygenase (α-KGD) using a 2-His-1-Asp facial triad. Our results demonstrated that the whole reaction proceeds through a quintet surface. The dioxygen activation by AsqJ leads to a quintet penta-coordinated Fe IV -oxo species, which has a square pyramidal geometry with the oxo group trans to His134. This penta-coordinated Fe IV -oxo species is not the reactive one in the substrate epoxidation reaction since its oxo group is pointing away from the target C[double bond, length as m-dash]C bond. Instead, it can undergo the oxo group isomerization followed by water binding or the water binding followed by oxygen atom exchange to form the reactive hexa-coordinated Fe IV -oxo species with the oxo group trans to His211. The calculated parameters of Mössbauer spectra for this hexa-coordinated Fe IV -oxo intermediate are in excellent agreement with the experimental values, suggesting that it is most likely the experimentally trapped species. The calculated energetics indicated that the rate-limiting step is the substrate C[double bond, length as m-dash]C bond activation. This work improves our understanding of the dioxygen activation by α-KGD and provides important structural information about the reactive Fe IV -oxo species.

Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

Energy Technology Data Exchange (ETDEWEB)

Malik, Riffat Naseem, E-mail: r_n_malik2000@yahoo.co.uk [Environmental Biology Laboratory, Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PO 45320 (Pakistan); Moeckel, Claudia [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Jones, Kevin C.; Hughes, David [Centre for Chemicals Management, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ (United Kingdom)

2011-10-15

Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of {Sigma}PBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher {Sigma}hexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured {Sigma}PBDEs pose no risk to egret population. - Highlights: > Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. > PBDE-47 and -100 frequent in feathers of fish eating egrets. > BDE-99 dominant in feathers of egrets feed in terrestrial habitats. > Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. > Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

International Nuclear Information System (INIS)

Malik, Riffat Naseem; Moeckel, Claudia; Jones, Kevin C.; Hughes, David

2011-01-01

Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of ΣPBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher Σhexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured ΣPBDEs pose no risk to egret population. - Highlights: → Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. → PBDE-47 and -100 frequent in feathers of fish eating egrets. → BDE-99 dominant in feathers of egrets feed in terrestrial habitats. → Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. → Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

The Relationship between Dioxin Congeners in the Breast Milk of Vietnamese Women and Sister Chromatid Exchange

Directory of Open Access Journals (Sweden)

Hiroyuki Suzuki

2014-04-01

Full Text Available The aim of this study was to clarify the relationship between dioxin concentrations in breast milk and the sister chromatid exchange (SCE frequency in women from herbicide-sprayed and non sprayed areas. Blood samples were taken from 21 women with high TCDD (tetrachlorodibenzo-p-dioxin levels from sprayed areas, 23 women with moderate TCDD levels from sprayed areas, and 19 women from non sprayed areas to determine their SCE frequency. The SCE frequencies for the high and moderate TCDD groups from the sprayed area and for the non sprayed area group were 2.40, 2.19, and 1.48 per cell, respectively. Multiple regression analysis showed that the standardized β values for 1,2,3,6,7,8-hexaCDD (β = 0.60, 1,2,3,4,6,7,8-heptaCDD (β = 0.64, and octaCDD (β = 0.65 were higher than those for TCDD (β = 0.34 and 1,2,3,7,8-pentaCDD (β = 0.42. The adjusted R2 value for polyCDDs (R2 = 0.38 was higher than that for polyCDD toxic equivalents (TEQ (toxic equivalents; R2 = 0.23. This study therefore shows that levels of hexa-, hepta-, and octaCDD, which were previously regarded as being less toxic than TCDD, are closely related to SCE frequency and that the level of dioxin (pg/g lipid is potentially more useful as an indicator than TEQ value for explaining SCE frequency.

Quantum chemical analysis of the electronic structure and Moessbauer spectra parameters for low spin cyanide- and pyridine-hemichromes

International Nuclear Information System (INIS)

Khleskov, V.I.; Kolpakov, E.V.; Smirnov, A.B.

1992-01-01

The work contains results of quantum-chemical calculations of electronic structure and Moessbauer spectra parameters for low spin S=1/2 hexa-coordinated ferri-porphyrin complexes with cyanide (CN) and pyridine (Py) as axial ligands. Theoretical results made it possible to explain experimentally observed regularity of anomalous quadrupole splitting decrease after substitution of Py-ligands by CN. Comparison of theoretical and experimental data indicated that 2 E g must be the ground state of investigated hemichromes. In this state unpaired electron symmetrically occupies d π -orbitals of Fe-ion. (orig.)

Synthesis, spectroscopy and antimicrobial activity of vanadium(III) and vanadium(IV) complexes involving Schiff bases derived from tranexamic acid and X-ray structure of Zwitter ion of tranexamic acid

International Nuclear Information System (INIS)

Shahzadi, S.; Ali, S.; Badshah, A.; Parvez, M.; Ahmed, E.; Malik, A.

2007-01-01

The synthesis of six new vanadium complexes of Schiff base derived from Tranexamic acid is reported. All the complexes were characterized by elemental analysis, infrared, electronic spectra, and mass spectrometry. FTIR data reveals that the Schiff base acts as a bidentate and the complexes exhibit the hexa-coordinated geometry in solid state. These complexes were screened for their biological activity against various bacterial and fungal strains. All the ligands show higher activity after complexation. The crystal structure of the Zwitter ion of the Tranexamic acid has been determined by X-ray single crystal diffraction [ru

CAA modeling of helicopter main rotor in hover

Science.gov (United States)

Kusyumov, Alexander N.; Mikhailov, Sergey A.; Batrakov, Andrey S.; Kusyumov, Sergey A.; Barakos, George

In this work rotor aeroacoustics in hover is considered. Farfield observers are used and the nearfield flow parameters are obtained using the in house HMB and commercial Fluent CFD codes (identical hexa-grids are used for both solvers). Farfield noise at a remote observer position is calculated at post processing stage using FW-H solver implemented in Fluent and HMB. The main rotor of the UH-1H helicopter is considered as a test case for comparison to experimental data. The sound pressure level is estimated for different rotor blade collectives and observation angles.

Determination of the radioactive concentration of 137Cs in soil

International Nuclear Information System (INIS)

1987-01-01

According to the latest Hungarian standard valid from January 1987 the activity concentration of 137 Cs in soil is determined based on the measurement of beta disintegration rate following the radiochemical separation of cesium ion. Soil samples are destructed with strong acid. Dissolved cesium is retained selectively by ammonium-molybdo-phosphate in a batch process. The inorganic ion-exchanger is dissoled with concentrated sodium-hydroxide, and, finally, cesium ion is precipitated with hexa-chloro-platinate. In the course of beta detection self-absoprtion of the precipitate must be corrected. (V.N.)

An introduction to the chemistry of complex compounds

CERN Document Server

Grinberg, Aleksander Abramovich; Trimble, R F

1962-01-01

An Introduction to the Chemistry of Complex Compounds discusses the fundamental concepts that are essential in understanding the underlying principles of complex compounds. The coverage of the book includes the compounds of the hexa, penta, and tetrammine type; compounds of the tri, dl, monoamine and hexacido types for the coordination number of 6; and complex compounds with a coordination number of 4. The text also covers the effects and chemical properties of complex compounds, such as the nature of the force of complex formation; the mutual effects of coordinated groups; and acid-base prope

Uranium thiolate complexes

International Nuclear Information System (INIS)

Leverd, Pascal C.

1994-01-01

This research thesis proposes a new approach to the chemistry of uranium thiolate complexes as these compounds are very promising for various uses (in bio-inorganic chemistry, in some industrial processes like oil desulphurization). It more particularly addresses the U-S bond or more generally bonds between polarizable materials and hard metals. The author thus reports the study of uranium organometallic thiolates (tricyclo-penta-dienic and mono-cyclo-octa-tetraenylic complexes), and of uranium homoleptic thiolates (tetra-thiolate complexes, hexa-thiolate complexes, reactivity of homoleptic thiolate complexes) [fr

Cationic Tungsten(VI) Penta-Methyl Complex: Synthesis, Characterization and its Application in Olefin Metathesis Reaction

KAUST Repository

Dey, Raju; Samantaray, Manoja; Callens, Emmanuel; Hamieh, Ali Imad Ali; Emwas, Abdul-Hamid M.; Abou-Hamad, Edy; Kavitake, Santosh Giridhar; Basset, Jean-Marie

2016-01-01

Tungsten-hexa-methyl readily reacts with B(C6F5)3 in dichloromethane and generates the corresponding well-defined cationic tungsten-penta-methyl complex which was identified precisely by 1H NMR, 13C NMR, 1H-13C NMR correlation spectroscopy. Unlike WMe6, this cationic complex has low energy barrier to form tungsten carbene intermediate, which was further supported by the fact that WMe6 alone has no activity in olefin metathesis reaction whereas the cationic complex shows catalytic activity for self-metathesis of 1-octene.

Cationic Tungsten(VI) Penta-Methyl Complex: Synthesis, Characterization and its Application in Olefin Metathesis Reaction

KAUST Repository

Dey, Raju

2016-04-13

Tungsten-hexa-methyl readily reacts with B(C6F5)3 in dichloromethane and generates the corresponding well-defined cationic tungsten-penta-methyl complex which was identified precisely by 1H NMR, 13C NMR, 1H-13C NMR correlation spectroscopy. Unlike WMe6, this cationic complex has low energy barrier to form tungsten carbene intermediate, which was further supported by the fact that WMe6 alone has no activity in olefin metathesis reaction whereas the cationic complex shows catalytic activity for self-metathesis of 1-octene.

Microbial and biochemical studies on phytase enzyme in some microorganisms

International Nuclear Information System (INIS)

Abdelbary, N.A.

1997-01-01

Mixed calcium and magnesium salts of phytic acid myoinositol hexa phosphoric acid are widely distributed in food stuffs of plant origin, they may bind essential proteins, phospholipids and microelements to form indigestible compounds. In this concern, destruction of phytic acid and its salts by different methods is very important, one of them is by using microbial phytase. This study aims to produce phytase enzyme from microorganisms and study the best conditions of production and purification and also the properties of the partially purified phytase. 22 figs., 29 tabs., 61 refs

Nitrosyl hemoglobins: EPR above 80 K

Energy Technology Data Exchange (ETDEWEB)

Wajnberg, E.; Bemski, G.; El-Jaick, L.J.; Alves, O.C.

1995-03-01

The EPR spectra of nitrosyl hemoglobin and myoglobin in different conditions (native, denatured and lyophilized), as well as of hematin-NO were obtained in the temperature range of 80 K-280 K. There is a substantial and reversible.decrease of the areas of the EPR spectra of all the hemoglobin samples above 150 K. The interpretation of the results implies the existence of two conformational states in thermal equilibrium only one of which is EPR detectable. Thermodynamical parameters are determined for the hexa and penta-coordinated cases. (author). 25 refs, 3 figs.

Nitrosyl hemoglobins: EPR above 80 K

International Nuclear Information System (INIS)

Wajnberg, E.; Bemski, G.; El-Jaick, L.J.; Alves, O.C.

1995-03-01

The EPR spectra of nitrosyl hemoglobin and myoglobin in different conditions (native, denatured and lyophilized), as well as of hematin-NO were obtained in the temperature range of 80 K-280 K. There is a substantial and reversible.decrease of the areas of the EPR spectra of all the hemoglobin samples above 150 K. The interpretation of the results implies the existence of two conformational states in thermal equilibrium only one of which is EPR detectable. Thermodynamical parameters are determined for the hexa and penta-coordinated cases. (author). 25 refs, 3 figs

Oxidative desulfurization of diesel fuel using amphiphilic quaternary ammonium phosphomolybdate catalysts

Energy Technology Data Exchange (ETDEWEB)

Qiu, Jianghua; Wang, Guanghui; Zeng, Danlin; Tang, Yan [College of Chemical Engineering and Technology, Wuhan University of Science and Technology, Wuhan 430081 (China); Wang, Meng; Li, Yanjun [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

2009-12-15

Phosphomolybdic acid (HPMo) modified respectively with tetramethyl ammonium chloride (TMAC), dodecyl trimethyl ammonium chloride (DTAC) and hexadecyl trimethyl ammonium chloride (HTAC) as the catalysts were prepared and characterized by FT-IR, XRD and SEM. The catalysts were evaluated for the oxidative desulfurization of benzothiophene (BT), dibenzothiophene (DBT) and straight-run diesel using hydrogen peroxide as an oxidant. Results show that all of the catalysts keep the Keggin structures and are finely dispersed with mixing of quaternary ammonium salts. Hexadecyl chains are more favorable to wrap up DBT to the catalytic center and form stable emulsion system with higher conversion rates of DBT. The shorter dodecyl chains can wrap up BT more suitably and bring smaller steric hindrance, which display higher conversion rates of BT. The oxidative reactions fit apparent first-order kinetics, and the apparent activation energies of DBT are much lower than those of BT. The desulfurization rate of straight-run diesel can be up to 84.4% with the recovery rate of 98.1% catalyzed by [HPMo][HTAC]{sub 2} in 2 h. When increasing the extraction times, the desulfurization rates increase, but the recovery rates of diesel decrease significantly. (author)

Síntese e avaliação da atividade fitotóxica de lactonas derivadas do 2,4-dimetil-8-oxabiciclo[3.2.1]-oct-6-en-3-ona

Directory of Open Access Journals (Sweden)

Barbosa Luiz Cláudio de Almeida

2002-01-01

Full Text Available The alkene 2,4-dimethyl-8-oxabicyclo[3.2.1]-oct-6-en-3-one (3 was converted to 1,3,10-trimethyl-8-oxabicyclo[5.3.0]-dec-3-ene-2,9-dione (7 and 1,3-dimethyl-8-oxabicyclo[5.3.0]-dec-3-ene-2,9-dione (8 with a 55% overall yield in both cases. Lactones (7 and (8 were converted in two steps to 1,3,4-trimethyl-13-methylene-6-oxatricyclo[8.3.0.0(3,7]-trideca-2,5,12-trione (12 (63% and 1,3-dimethyl-13-methylene-6-oxatricycle[8.3.0.0(3,7]-trideca-2,5,12-trione (13 (45% from 8. The effect of lactones (7, (8, (12, (13 and the intermediates (5 and (6, at the concentration of 250 mug mL-1, on the growth of Cucumis sativus L. and Sorghum bicolor L. was evaluated. The best results were observed for lactone (13 that caused 100% inhibition on the root growth of C. sativus and lactone (12 that inhibited 90% of the root growth for S. bicolor.

Synthesis and characterization of organosilicon compounds as novel precursors for CVD processes

Energy Technology Data Exchange (ETDEWEB)

Ermakova, E.N.; Sysoev, S.V.; Nikulina, L.D. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 3, Novosibirsk 630090 (Russian Federation); Tsyrendorzhieva, I.P.; Rakhlin, V.I. [Favorskii Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorskii Str. 1, Irkutsk 664033 (Russian Federation); Kosinova, M.L., E-mail: marina@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 3, Novosibirsk 630090 (Russian Federation)

2015-12-20

Highlights: • The temperature dependences of vapor pressure of four precursors have been measured. • The experimental data were used to calculate standard thermodynamic functions. • The thermodynamic modelling of SiC{sub x}N{sub y} films formation has been performed. - Abstract: Chemical vapor deposition using single-source organosilicon precursors is one of the most effective ways to produce multifunctional SiC{sub x}N{sub y} films. It is worth mentioning that the precursor molecule design affects both the composition and properties of films. Four organosilicon compounds containing a phenyl substituent (namely, trimethylphenylsilane, trimethyl(phenylamino) silane, trimethyl(benzylamino)silane and bis(trimethylsilyl)phenylamine) have been synthesized and characterized as potential CVD precursors for SiC{sub x}N{sub y} films synthesis. The compounds have been shown to be volatile and stable enough to be used in chemical vapor deposition of SiC{sub x}N{sub y} films. Thermodynamic modeling of the film deposition from the gaseous mixture of trimethylphenylsilane and ammonia in Si–C–N–H system has demonstrated that SiC{sub x}N{sub y} films can be deposited, and there is an opportunity to determine the area of appropriate deposition conditions.

The tumor suppressor Rb and its related Rbl2 genes are regulated by Utx histone demethylase

Energy Technology Data Exchange (ETDEWEB)

Terashima, Minoru; Ishimura, Akihiko; Yoshida, Masakazu [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan); Suzuki, Yutaka; Sugano, Sumio [Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Chiba (Japan); Suzuki, Takeshi, E-mail: suzuki-t@staff.kanazawa-u.ac.jp [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan)

2010-08-20

Research highlights: {yields} Utx increases expression of Rb and Rbl2 genes through its demethylase activity. {yields} Utx changes histone H3 methylation on the Rb and Rbl2 promoters. {yields} Utx induces decreased cell proliferation of mammalian primary cells. -- Abstract: Utx is a candidate tumor suppressor gene that encodes histone H3 lysine 27 (H3K27) demethylase. In this study, we found that ectopic expression of Utx enhanced the expression of retinoblastoma tumor suppressor gene Rb and its related gene Rbl2. This activation was dependent on the demethylase activity of Utx, and was suggested to contribute to the decreased cell proliferation induced by Utx. A chromatin immunoprecipitation assay showed that over-expressed Utx was associated with the promoter regions of Rb and Rbl2 resulting in the removal of repressive H3K27 tri-methylation and the increase in active H3K4 tri-methylation. Furthermore, siRNA-mediated knockdown of Utx revealed the recruitment of endogenous Utx protein on the promoters of Rb and Rbl2 genes. These results indicate that Rb and Rbl2 are downstream target genes of Utx and may play important roles in Utx-mediated cell growth control.

Synthesis and purification of some alkyl phenanthrenes and presentation of their infrared, ultraviolet, nuclear magnetic resonance and mass spectra; Synthese et purification de quelques alcoylphenanthrenes et presentation ds leurs spectres d'absorption infrarouge, ultraviolette, de resonance magnetique nucleaire et de masse

Energy Technology Data Exchange (ETDEWEB)

Persaud, K. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-01-01

We have carried out the synthesis of: - phenanthrene - its five monomethyl derivatives - three dimethyl derivatives - two trimethyl derivatives. We have then purified these products as well as a certain number of others obtained from various sources. We have been able to obtain in the majority of cases, a purity of 99.5 per cent or over, these figures being obtained by low voltage mass spectrometry. Finally we have recorded the infrared, ultraviolet, nuclear magnetic resonance and mass spectra of these products for which an atlas has been drawn up. (author) [French] Nous avons realise la synthese: - du phenanthrene - de ses cinq derives monomethyles - de trois de ses derives dimethyles - de deux de ses derives trimethyles. Nous avons ensuite purifie ces produits ainsi qu'un certain nombre d'autres que nous avons obtenus de sources differentes. Nous avons pu atteindre, dans la plupart des cas, une purete egale ou superieure a 99,5 pour cent, chiffres determines par la spectrometrie de masse a basse tension. Enfin, nous avons enregistre les spectres infrarouges, ultraviolets, de resonance magnetique nucleaire et de masse de ces produits dont nous avons fait un atlas. (auteur)

ATRX ADD domain links an atypical histone methylation recognition mechanism to human mental-retardation syndrome

Energy Technology Data Exchange (ETDEWEB)

Iwase, Shigeki; Xiang, Bin; Ghosh, Sharmistha; Ren, Ting; Lewis, Peter W.; Cochrane, Jesse C.; Allis, C. David; Picketts, David J.; Patel, Dinshaw J.; Li, Haitao; Shi, Yang (Harvard-Med); (Ottawa Hosp.); (MSKCC); (Rockefeller); (CH-Boston); (Tsinghua); (Mass. Gen. Hosp.)

2011-07-19

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at pericentromeric heterochromatin; thus, we have discovered a unique histone-recognition mechanism underlying the ATR-X etiology.

ATRX ADD Domain Links an Atypical Histone Methylation Recognition Mechanism to Human Mental-Retardation Syndrome

Energy Technology Data Exchange (ETDEWEB)

S Iwase; B Xiang; S Ghosh; T Ren; P Lewis; J Cochrane; C Allis; D Picketts; D Patel; et al.

2011-12-31

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at pericentromeric heterochromatin; thus, we have discovered a unique histone-recognition mechanism underlying the ATR-X etiology.

Electrochemical determination of resveratrol in dietary supplements at a boron-doped diamond electrode in the presence of hexadecyltrimethylammonium bromide using square-wave adsorptive stripping voltammetry

Directory of Open Access Journals (Sweden)

Yardim Yavuz

2017-01-01

Full Text Available A sensitive electroanalytical methodology for the determination of resveratrol is presented for the first time using adsorptive stripping voltammetry at a bare boron-doped diamond (BDD electrode. In cyclic voltammetry, resveratrol shows one irreversible and an adsorption-controlled oxidation peak at a BDD electrode. The voltammetric results indicated that in the presence of hexadecyl trimethyl ammonium bromide, the BDD electrode remarkably enhanced the oxidation of resveratrol, which leads to an improvement in the peak current with a shift of the peak potential to more positive values. Using the square-wave stripping mode, the compound yielded a well-defined voltammetric response in 0.1 M nitric acid solution containing 100 μmol L-1 hexadecyl trimethyl ammonium bromide at 0.74 V (vs. Ag/AgCl, after 60 s accumulation at the open-circuit condition. A linear calibration graph was obtained in the concentration range 0.025 to 60.0 μg mL-1, with a detection limit of 0.0063 μg mL-1. The applicability of the proposed method was verified by analysis of resveratrol in commercial dietary supplements.

Mouse MORC3 is a GHKL ATPase that localizes to H3K4me3 marked chromatin.

Science.gov (United States)

Li, Sisi; Yen, Linda; Pastor, William A; Johnston, Jonathan B; Du, Jiamu; Shew, Colin J; Liu, Wanlu; Ho, Jamie; Stender, Bryan; Clark, Amander T; Burlingame, Alma L; Daxinger, Lucia; Patel, Dinshaw J; Jacobsen, Steven E

2016-08-30

Microrchidia (MORC) proteins are GHKL (gyrase, heat-shock protein 90, histidine kinase, MutL) ATPases that function in gene regulation in multiple organisms. Animal MORCs also contain CW-type zinc finger domains, which are known to bind to modified histones. We solved the crystal structure of the murine MORC3 ATPase-CW domain bound to the nucleotide analog AMPPNP (phosphoaminophosphonic acid-adenylate ester) and in complex with a trimethylated histone H3 lysine 4 (H3K4) peptide (H3K4me3). We observed that the MORC3 N-terminal ATPase domain forms a dimer when bound to AMPPNP. We used native mass spectrometry to show that dimerization is ATP-dependent, and that dimer formation is enhanced in the presence of nonhydrolyzable ATP analogs. The CW domain uses an aromatic cage to bind trimethylated Lys4 and forms extensive hydrogen bonds with the H3 tail. We found that MORC3 localizes to promoters marked by H3K4me3 throughout the genome, consistent with its binding to H3K4me3 in vitro. Our work sheds light on aspects of the molecular dynamics and function of MORC3.

Phthalates production from Curvularia senegalensis (Speg.) Subram, a fungal species associated to crops of commercial value.

Science.gov (United States)

Lucas, Esther M F; Abreu, Lucas M; Marriel, Ivanildo E; Pfenning, Ludwig H; Takahashi, Jacqueline A

2008-01-01

The fungal species Curvularia senegalensis was isolated from a soil sample collected at a Brazilian region of cerrado transition. This microorganism was grown in vitro and the extract of the culture medium was fractionated by chromatographic methods yielding an oil rich in phthalates, from which seven derivatives were identified by infrared, 1H and 13C NMR and mass spectrometry as 1-hexyl-2-propylphthalate, 1-ethyl-2-heptylphthalate, 1-hexyl-2-butylphthalate, 1-heptyl-2-proylphthalate, 1-propyl-2-nonylphthalate and two positional isomers of 1-decyl-2-butane phthalate. This is the first report on the phthalates production by Curvularia senegalensis revealing a scientific basis for the use of this species on biodegradation experiments. Since C. senegalensis is a very common pathogen in some commercial crops, presence of highly toxic phthalates on the final feed products should be investigated.

Biological stereoselective reduction of 3,3,5-trimethylcyclohexanone by Glomerella cingulata.

Science.gov (United States)

Okamura, S; Kameoka, H; Miyazawa, M

2001-01-01

The microbial transformation of 3,3,5-trimethylcyclohexanone was investigated using the plant pathogenic fungus, Glomerella cingulata. With this organism 3,3,5-trimethylcyclohexanone gave the corresponding cis- and trans-3,3,5-trimethylcyclohexanols with the ratio of 20:1 forming the cis-isomer highly stereoselectively, upon 5 days incubation together with 3,3,5-trimethyl-2-cyclohexen-1-one (isophrone) as a minor product.

Engineering Design Handbook Short Fiber Plastic Base Composites

Science.gov (United States)

1975-07-31

A adduct f. neopentyl glycol g. trimethyl pentanediol a. styrene b. methyl methacrylate c. vinyl toluene Characteristics a. lowest cost...dibasic acid or an unsaturated anhydride with a glycol . Most polyesters include as a third component a saturated dibasic acid or anhydride. The...anhydride, propylene glycol , and styrene monomer are used for lowest cost; isophthalic acid may be added for higher heat resistance and improved

Synthesis of Secondary Aromatic Amides via Pd-Catalyzed Aminocarbonylation of Aryl Halides Using Carbamoylsilane as an Amide Source.

Science.gov (United States)

Tong, Wenting; Cao, Pei; Liu, Yanhong; Chen, Jianxin

2017-11-03

Using N-methoxymethyl-N-organylcarbamoyl(trimethyl)silanes as secondary amides source, the direct transformation of aryl halides into the corresponding secondary aromatic amides via palladium-catalyzed aminocarbonylation is described. The reactions tolerated a broad range of functional groups on the aryl ring except big steric hindrance of substituent. The types and the relative position of substituents on the aryl ring impact the coupling efficiency.

Resin for processing radioactive waste water

International Nuclear Information System (INIS)

Onozuka, Teruo; Shindo, Manabu; Kiba, Hideaki; Kubota, Hirohisa; Sawada, Shintaro.

1995-01-01

The present invention concerns an anionic exchange resin having a long service life with less radiation degradation. The resin is an anionic exchange resin in which a trimethyl ammonium group is introduced to a copolymer of 4-bromo-butoxymethyl styrene and divinyl benzene. The resin is excellent in economic performance, and can reduce the frequency for the exchange of cross-linked anionic exchangers. (T.M.)

Resin for processing radioactive waste water

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Teruo; Shindo, Manabu [Tohoku Electric Power Co., Inc., Sendai (Japan); Kiba, Hideaki; Kubota, Hirohisa; Sawada, Shintaro

1995-11-07

The present invention concerns an anionic exchange resin having a long service life with less radiation degradation. The resin is an anionic exchange resin in which a trimethyl ammonium group is introduced to a copolymer of 4-bromo-butoxymethyl styrene and divinyl benzene. The resin is excellent in economic performance, and can reduce the frequency for the exchange of cross-linked anionic exchangers. (T.M.).

40 CFR Table 2a to Subpart E of... - Reactivity Factors

Science.gov (United States)

2010-07-01

....49 Monoisopropanol Amine (1-Amino-2-Propanol) 78-96-6 13.42 Trichloroethylene 79-01-6 0.60 Propionic... Acetate (1-Methoxy-2-Propyl Acetate) 108-65-6 1.71 1,3,5-Trimethyl Benzene 108-67-8 11.22 Di-Isobutyl...-(2-Methoxyethoxy) Ethanol) 111-77-3 2.90 n-Nonane 111-84-2 0.95 2-(2-Ethoxyethoxy) Ethanol 111-90-0 3...

Post-Translational Modifications of Desulfovibrio vulgaris Hildenborough Sulfate Reduction Pathway Proteins

Energy Technology Data Exchange (ETDEWEB)

Gaucher, S.P.; Redding, A.M.; Mukhopadhyay, A.; Keasling, J.D.; Singh, A.K.

2008-03-01

Recent developments in shotgun proteomics have enabled high-throughput studies of a variety of microorganisms at a proteome level and provide experimental validation for predicted open reading frames in the corresponding genome. More importantly, advances in mass spectrometric data analysis now allow mining of large proteomics data sets for the presence of post-translational modifications(PTMs). Although PTMs are a critical aspectof cellular activity, such information eludes cell-wide studies conducted at the transcript level. Here, we analyze several mass spectrometric data sets acquired using two-dimensional liquid chromatography tandem mass spectrometry, 2D-LC/MS/MS, for the sulfate reducing bacterium, Desulfovibrio vulgaris Hildenborough. Our searches of the raw spectra led us to discover several post-translationally modified peptides in D. vulgaris. Of these, several peptides containing a lysine with a +42 Da modification were found reproducibly across all data sets. Both acetylation and trimethylation have the same nominal +42 Da mass, and are therefore candidates for this modification. Several spectra were identified having markers for trimethylation, while one is consistent with an acetylation. Surprisingly, these modified peptides predominantly mapped to proteins involved in sulfate respiration. Other highly expressed proteins in D. vulgaris, such as enzymes involved in electron transport and other central metabolic processes, did not contain this modification. Decoy database searches were used to control for random spectrum/sequence matches. Additional validation for these modifications was provided by alternate workflows, for example, two-dimensional gel electrophoresis followed by mass spectrometry analysis of the dissimilatory sulfite reductase gamma-subunit(DsrC) protein. MS data for DsrC in this alternate workflow also contained the +42 Da modification at the same loci. Furthermore, the DsrC homologue in another sulfate reducing bacterium

The methyltransferase NSD3 has chromatin-binding motifs, PHD5-C5HCH, that are distinct from other NSD (nuclear receptor SET domain) family members in their histone H3 recognition.

Science.gov (United States)

He, Chao; Li, Fudong; Zhang, Jiahai; Wu, Jihui; Shi, Yunyu

2013-02-15

The NSD (nuclear receptor SET domain-containing) family members, consisting of NSD1, NSD2 (MMSET/WHSC1), and NSD3 (WHSC1L1), are SET domain-containing methyltransferases and aberrant expression of each member has been implicated in multiple diseases. They have specific mono- and dimethylase activities for H3K36, whereas play nonredundant roles during development. Aside from the well characterized catalytic SET domain, NSD proteins have multiple potential chromatin-binding motifs that are clinically relevant, including the fifth plant homeodomain (PHD5) and the adjacent Cys-His-rich domain (C5HCH) located at the C terminus. Herein, we report the crystal structures of the PHD5-C5HCH module of NSD3, in the free state and in complex with H3(1-7) (H3 residues 1-7), H3(1-15) (H3 residues 1-15), and H3(1-15)K9me3 (H3 residues 1-15 with trimethylation on K9) peptides. These structures reveal that the PHD5 and C5HCH domains fold into a novel integrated PHD-PHD-like structural module with H3 peptide bound only on the surface of PHD5 and provide the molecular basis for the recognition of unmodified H3K4 and trimethylated H3K9 by NSD3 PHD5. Structural studies and binding assays show that differences exist in histone binding specificity of the PHD5 domain between three members of the NSD family. For NSD2, the PHD5-C5HCH:H3 N terminus interaction is largely conserved, although with a stronger preference for unmethylated H3K9 (H3K9me0) than trimethylated H3K9 (H3K9me3), and NSD1 PHD5-C5HCH does not bind to H3 peptides. Our results shed light on how NSD proteins that mediate H3K36 methylation are localized to specific genomic sites and provide implications for the mechanism of functional diversity of NSD proteins.

Reactions of alkylnitrosoureas in aqueous solution

International Nuclear Information System (INIS)

Snyder, J.K.; Stock, L.M.

1980-01-01

The acid- and base-catalyzed decompositions of N-methyl-,N,N'-dimethyl-, and N,N',N'-trimethyl-N-nitrosourea in aqueous solution have been studied. Below pH 2, the N-methyl compound undergoes both denitrosation and hydrolysis to yield methylurea, nitrous acid, methylamine, nitrogen, and carbon dioxide. The acid-catalyzed denitrosation and hydrolysis of the trimethylnitrosourea are somewhat more rapid than the corresponding reactions of N-methyl-N-nitrosourea. The solvent isotope effect, k/sub H 2 O//k/sub D 2 O/ = 1.3, and the absence of chloride ion catalysis suggest that the denitrosation reaction proceeds by a rate-determining proton transfer which is followed by the rapid loss of the nitroso group. The results for the hydrolysis reaction are compatible with a formulation in which a hydrate of the nitrosourea is protonated in a rate-determining step to form a tetrahedral intermediate which subsequently decomposes to yield methyldiazonium hydroxide and a carbamic acid derivative. The base-catalyzed reactions of the mono, di-, and trimethylnitrosoureas are first order in hydroxide ion over a broad pH range. The hydrolysis of N-methyl-N-nitrosourea yields methanol and derivatives of carbamic acid. Salt effects on the reaction rate are negligible except for the influence of lithium ion. The rate constants for the hydrolysis of the mono- and dimethyl compounds depend upon the buffer concentrationat pH 9.5. The rate constants for the hydrolysis of the trimethyl compound also depend upon the buffer concentration, but a limiting value is not achieved. The solvent isotope effect for the base-catalyzed reaction, the exchange reaction of water- 18 O with the carbonyl group of the urea, and the fact that N-methyl-N-nitrosourea is hydrolyzed about 2.2 x 10 4 times more rapidly than N,N',N'-trimethyl-N-nitrosourea suggest that the hydrolysis occurs by a mechanism in which a tetrahedral intermediate is formed

Occurrence and formation of endogenous histidine hexa-coordination in cold-adapted hemoglobins.

Science.gov (United States)

Merlino, Antonello; Howes, Barry D; Prisco, Guido di; Verde, Cinzia; Smulevich, Giulietta; Mazzarella, Lelio; Vergara, Alessandro

2011-05-01

Spectroscopic and crystallographic evidence of endogenous (His) ligation at the sixth coordination site of the heme iron has been reported for monomeric, dimeric, and tetrameric hemoglobins (Hbs) in both ferrous (hemochrome) and ferric (hemichrome) oxidation states. In particular, the ferric bis- histidyl adduct represents a common accessible ordered state for the β chains of all tetrameric Hbs isolated from Antarctic and sub-Antarctic fish. Indeed, the crystal structures of known tetrameric Hbs in the bis-His state are characterized by a different binding state of the α and β chains. An overall analysis of the bis-histidyl adduct of globin structures deposited in the Protein Data Bank reveals a marked difference between hemichromes in tetrameric Hbs compared to monomeric/dimeric Hbs. Herein, we review the structural, spectroscopic and stability features of hemichromes in tetrameric Antarctic fish Hbs. The role of bis-histidyl adducts is also addressed in a more evolutionary context alongside the concept of its potential physiological role. Copyright © 2011 Wiley Periodicals, Inc.

The effects of acute L-carnitine administration on ventilatory breakpoint and exercise performanceduring incremental exercise

OpenAIRE

Mojtaba Kaviani; Maryam Nourshahi; Farhad Shokoohi

2009-01-01

(Received 31 October, 2009 ; Accepted 10 March, 2010)AbstractBackground and purpose: Many athletes adopt nutritional manipulations to improve their performance. Among the substances generally consumed is carnitine (L-trimethyl-3-hydroxy-ammoniobutanoate) which has been used by athletes as an ergogenic aid, due to its role in the transport of long-chain fatty acids across mitochondrial membranes. Nutritional supplements containing carbohydrates, proteins, vitamins, and minerals have been widel...

The 1:1 adduct of caffeine and 2-(1,3-dioxoisoindolin-2-ylacetic acid

Directory of Open Access Journals (Sweden)

Moazzam H. Bhatti

2011-09-01

Full Text Available In the crystal structure of the title adduct [systematic name: 2-(1,3-dioxoisoindolin-2-ylacetic acid–1,3,7-trimethyl-1,2,3,6-tetrahydro-7H-purine-2,6-dione (1/1], C8H10N4O2·C10H7NO4, the components are linked by an O—H...N hydrogen-bond and no proton transfer occurs.

A cohort study to evaluate persistence of hepatitis B immunogenicity after administration of hexavalent vaccines

Directory of Open Access Journals (Sweden)

Chionne Paola

2008-07-01

Full Text Available Abstract Background In 2001, two hexavalent vaccines were licensed in Italy (Hexavac®, Infanrix Hexa®, and since 2002 were extensively used for primary immunization in the first year of life (at 3, 5, 11/12 months of age. In 2005, the market authorization of Hexavac® was precautionary suspended by EMEA, because of doubts on long-term protection against hepatitis B virus. The objectives of this study were to evaluate the persistence of antibodies to anti-HBs, in children in the third year of life, and to investigate the response to a booster dose of hepatitis B vaccine. Methods Participant children were enrolled concomitantly with the offering of anti-polio booster dose, in the third year of life. Anti-HBs titers were determined on capillary blood samples. A booster dose of hepatitis B vaccine was administered to children with anti-HBs titers Results Sera from 113 children previously vaccinated with Hexavac®, and from 124 vaccinated with Infanrix Hexa® were tested for anti-HBs. Titers were ≥ 10 mIU/ml in 69% and 96% (p Post-booster, 93% of children achieved titers ≥ 10 mIU/ml, with no significant difference by vaccine group. Discussion Fifteen months after third dose administration, a significant difference in anti-HBs titers was noted in the two vaccine groups considered. Monovalent hepatitis B vaccine administration in 3-year old children induced a proper booster response, confirming that immunologic memory persists in children with anti-HBs titers

Structural, spectral and magnetic studies of two Co(II)-N-heterocyclic diphosphonates based on multinuclear units

Science.gov (United States)

Zhao, Chen; Ma, Kui-Rong; Zhang, Yu; Kan, Yu-He; Li, Rong-Qing; Hu, Hua-You

2016-01-01

Two examples of Co(II)-N-heterocyclic coordination polymers based on 1-hydroxyethylidenediphosphonic acid (H5L = CH3C(OH)(PO3H2)2), namely 0.5(H3NCH2CH2NH3)·[Co6(Cl2)(H3L)2(H2L)(HL)(2,2‧-bipy)6] 1 and 2(NH4)·[Co3(HL)2(H2O)2(phen)2]·2(H2O) 2, have been solvothermally obtained by introducing the second ligands 2,2‧-bipyridine/1,10-phenanthroline (2,2‧-bipy/phen) and characterized by powder X-ray diffraction (PXRD), elemental analysis, IR, TG-DSC. The single-crystal X-ray diffractions show that compound 1 possesses a 0-D structure with hexa-nuclear cluster [Co6(O-P-O)8] built through single/double O-P-O bridges and compound 2 displays a 1-D ladder-like chain structure with magnetic topology building blocks [Co4(O-P-O)4]n. Then H-bonding and π-π stacking interactions further expand the two low-dimensional structures into three-dimensional supramolecular frameworks. Fluorescent measurements reveal that both the maximum emission peaks of 1-2 are centered at 423 nm, mainly deriving from intraligand π*-π transition state of N-heterocyclic ligand 2,2‧-bipy/phen, respectively. Magnetism data indicate that 1 exhibits antiferromagnetic behavior within hexa-nuclear Co(II) clusters, while 2 shows weak ferromagnetic interactions in 1-D topology Co(II)-chain, showing promising potential as magnetic materials.

CCDC 860715: Experimental Crystal Structure Determination : catena-[bis(mu-oxido)-tris(mu-5,5'-ethyne-1,2-diyldiisophthalato)-hexa-aqua-hexa-indium dinitrate acetonitrile N,N-dimethylformamide solvate sesquihydrate

KAUST Repository

Zheng, Bing; Sun, Xiaodong; Li, Guanghua; Cairns, Amy J.; Kravtsov, Victor Ch.; Huo, Qisheng; Liu, Yunling; Eddaoudi, Mohamed

2016-01-01

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Neutron spin-echo investigation of the microemulsion dynamics. in bicontinuous lamellar and droplet phases

CERN Document Server

Mihailescu, M; Endo, H; Allgaier, J; Gompper, G; Stellbrink, J; Richter, D; Jakobs, B; Sottmann, T; Faragó, B

2002-01-01

Using neutron spin-echo (NSE) spectroscopy in combination with dynamic light scattering (DLS), we performed an extensive investigation of the bicontinuous phase in ternary water-surfactant-oil microemulsions, with extension to lamellar and droplet phases. The dynamical behavior of surfactant monolayers of decyl-polyglycol-ether (C sub 1 sub 0 E sub 4) molecules, or mixtures of surfactant with long amphiphilic block-copolymers of type poly-ethylene propylene/poly-ethylene oxide (PEP-PEO) was studied, under comparable conditions. The investigation techniques provide access to different length scales relative to the characteristic periodicity length of the microemulsion structure. Information on the elastic bending modulus is obtained from the local scale dynamics in view of existing theoretical descriptions and is found to be in accordance with small angle neutron scattering (SANS) studies. Evidence for the modified elastic properties and additional interaction of the amphiphilic layers due to the polymer is mo...

Alternative process for treating radioactive effluents

International Nuclear Information System (INIS)

Puget, Flavia P.; Massarani, Giulio

2002-01-01

In this work an alternative process for treating a wastewater containing dissolved uranium is considered. In order to develop this work, a continuous separation unit, characterized by the solvent extraction, carried out inward the ejector is used. Alamina 336 (a mixture of tri-octyl and tri-decyl amines) is used as extractant in this process. The splitting of the amine-water emulsion formed is carried out in a gravitational separation tank. The result showed that it is possible to reach an efficiency of about 95% for the uranium extraction, for metal concentration in the feed of 10 ppm and a Q fa /Q fo ratio around 500. Furthermore, an efficiency of about 50% is reached for metal concentration in the feed of 1 ppm and for aQ fa /Q fo ratio around 1000, when the liquid flow rate is equal 1200 L/h. (author)

pH regulation of the kinetic stability of the lipase from Thermomyces lanuginosus

DEFF Research Database (Denmark)

Wang, H.; Andersen, Kell Kleiner; Sehgal, P.

2013-01-01

Thermomyces lanuginosus lipase (TlL) is a kinetically stable protein, resistant toward both denaturation and refolding in the presence of the ionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant decyl maltoside (DecM). We investigate the pH dependence of this kinetic stability....... At pH 8, TlL remains folded and enzymatically active at multimillimolar surfactant concentrations but fails to refold from the acid urea-denatured state at submillimolar concentrations of SDS and DecM, indicating a broad concentration range of kinetic trapping or hysteresis. At pH 8, very few SDS...... molecules bind to TlL. The hysteresis SDS concentration range shrinks when moving to pH 4–6; in this pH range, SDS binds as micellelike clusters. Although hysteresis can be eliminated by reducing disulfide bonds, destabilizing the native state, and lowering the unfolding activation barrier, SDS sensitivity...

Extraction of cobalt ion from textile using a complexing macromolecular surfactant in supercritical carbon dioxide

International Nuclear Information System (INIS)

Chirat, Mathieu; Ribaut, Tiphaine; Clerc, Sebastien; Lacroix-Desmazes, Patrick; Charton, Frederic; Fournel, Bruno

2013-01-01

Cobalt ion under the form of cobalt nitrate is removed from a textile lab coat using supercritical carbon dioxide extraction. The process involves a macromolecular additive of well-defined architecture, acting both as a surfactant and a complexing agent. The extraction efficiency of cobalt reaches 66% when using a poly(1,1,2,2-tetrahydroperfluoro-decyl-acrylate-co-vinyl-benzylphosphonic diacid) gradient copolymer in the presence of water at 160 bar and 40 C. The synergy of the two additives, namely the copolymer and water which are useless if used separately, is pointed out. The potential of the supercritical carbon dioxide process using complexing macromolecular surfactant lies in the ability to modulate the complexing unit as a function of the metal as well as the architecture of the surface-active agent for applications ranging for instance from nuclear decontamination to the recovery of strategic metals. (authors)

Partition Coefficients of Amino Acids, Peptides, and Enzymes in Dextran + Poly(Ethylene Glycol) + Water Aqueous Two-Phase Systems

Energy Technology Data Exchange (ETDEWEB)

Kakisaka, Keijiro.; Shindo, Takashi.; Iwai, Yoshio.; Arai, Yasuhiko. [Kyushu University, Fukuoka (Japan). Department of Chemical Systems and Engineering

1998-12-01

Partition coefficients are measured for five amino acids(aspartic acid, asparagine, methionine, cysteine and histidine) and tow peptides(glycyl-glycine and hexa-glycine) in dextran + poly(ethylene glycol) + water aqueous two-phase system. The partition coefficients of the amino acids and peptides are aorrelated using the osmotic virial equation. The interaction coefficients contained in the equation can be calculated by hydrophilic group parameters. The partition coefficients of {alpha}-amylase calculated by the osmotic virial equation with the hydrophilic group parameters are in fairly good agreement with the experimental data, though a relatively large discrepancy is shown for {beta}-amylase. (author)

Partition Coefficients of Amino Acids, Peptides, and Enzymes in Dextran + Poly(Ethylene Glycol) + Water Aqueous Two-Phase Systems

Energy Technology Data Exchange (ETDEWEB)

Kakisaka, Keijiro.; Shindo, Takashi.; Iwai, Yoshio.; Arai, Yasuhiko. (Kyushu University, Fukuoka (Japan). Department of Chemical Systems and Engineering)

1998-12-01

Partition coefficients are measured for five amino acids(aspartic acid, asparagine, methionine, cysteine and histidine) and tow peptides(glycyl-glycine and hexa-glycine) in dextran + poly(ethylene glycol) + water aqueous two-phase system. The partition coefficients of the amino acids and peptides are aorrelated using the osmotic virial equation. The interaction coefficients contained in the equation can be calculated by hydrophilic group parameters. The partition coefficients of [alpha]-amylase calculated by the osmotic virial equation with the hydrophilic group parameters are in fairly good agreement with the experimental data, though a relatively large discrepancy is shown for [beta]-amylase. (author)

CAA modeling of helicopter main rotor in hover

Directory of Open Access Journals (Sweden)

Kusyumov Alexander N.

2017-01-01

Full Text Available In this work rotor aeroacoustics in hover is considered. Farfield observers are used and the nearfield flow parameters are obtained using the in house HMB and commercial Fluent CFD codes (identical hexa-grids are used for both solvers. Farfield noise at a remote observer position is calculated at post processing stage using FW–H solver implemented in Fluent and HMB. The main rotor of the UH-1H helicopter is considered as a test case for comparison to experimental data. The sound pressure level is estimated for different rotor blade collectives and observation angles.

Oxovanadium (iv) complexes with n/o- and o-donor ligands: their synthesis, characterization, semiempirical study and alkaline phosphatase activity (abstract)

International Nuclear Information System (INIS)

Munawar, K.S.; Ali, S.; Khan, A.N.

2011-01-01

Various N/O- and O-donor ligands and their oxovanadium complexes have been synthesized and characterized by different techniques such as FTIR, elemental analysis, thermogravimetery and conductometry. The IR data show the bidentate nature of the ligands and reveals hexa-coordinated geometry in the solid state which is also confirmed by semi-empirical study. Conductance measurements reveal the non-electrolytic nature of the complexes. These complexes have been checked for their alkaline phosphatase activity in the presence and absence of inhibitor which shows that by the addition of inhibitor the activity of enzyme decreases and at higher concentration it is completely inhibited. (author)

Method of preparation of tritiated benzene for measuring in hydrology low level tritium in a liquid scintillator

International Nuclear Information System (INIS)

Pichat, L.; Sharefkin, D.; Herbert, M.

1962-01-01

It is given a preliminary account of the preparation of tritiated benzene by decarboxylation of calcium mellitate (calcium benzene-hexa-carboxylate) at 500 deg C by an excess of tritiated barium or calcium hydroxide yield is 64-72 pour cent based on used calcium mellitate. Benzene obtained after a single distillation is free from seriously quenching impurities. It is obtained 10-15 g benzene per batch. It remains to determine the occurrence of an isotope effect during the reaction. Various improvements and modifications are still necessary to increase the size of the sample to be treated. (authors) [fr

Mechatronics control technology

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-03-15

This book consists six chapters, which are an assembler grammar and practical use on Z801 8041/8048 and kind of assemblers and how to use, control of a microprocessor and mechatro with application of 8255, interface circuit and direction of DA converter, control of stepping motor such as introduction of it, sequence switch, drive program of stepping motor, control for DC motor such as normal rotation and abnormal rotation operation of DC motor by personal computer, control AC motor like PWM inverter and data communication among systems such as RS-232C and INTEL-HEXA format program.

Mechatronics control technology

International Nuclear Information System (INIS)

1988-03-01

This book consists six chapters, which are an assembler grammar and practical use on Z801 8041/8048 and kind of assemblers and how to use, control of a microprocessor and mechatro with application of 8255, interface circuit and direction of DA converter, control of stepping motor such as introduction of it, sequence switch, drive program of stepping motor, control for DC motor such as normal rotation and abnormal rotation operation of DC motor by personal computer, control AC motor like PWM inverter and data communication among systems such as RS-232C and INTEL-HEXA format program.

Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C2-symmetric building block: a strategy for the synthesis of decanolide natural products

Directory of Open Access Journals (Sweden)

Bernd Schmidt

2013-11-01

Full Text Available Starting from the conveniently available ex-chiral pool building block (R,R-hexa-1,5-diene-3,4-diol, the ten-membered ring lactones stagonolide E and curvulide A were synthesized using a bidirectional olefin-metathesis functionalization of the terminal double bonds. Key steps are (i a site-selective cross metathesis, (ii a highly diastereoselective extended tethered RCM to furnish a (Z,E-configured dienyl carboxylic acid and (iii a Ru–lipase-catalyzed dynamic kinetic resolution to establish the desired configuration at C9. Ring closure was accomplished by macrolactonization. Curvulide A was synthesized from stagonolide E through Sharpless epoxidation.

Comparative study of the singularity in the optical properties of congruent doped LiNbO3 crystals

International Nuclear Information System (INIS)

Jaque, F.; Han, T.P.J.; Lifante, G.

2003-01-01

A comparison of the optical properties such as optical absorption band edge, ordinary and extraordinary refractive indices, powder second harmonic generation and the non-linear coefficient, d 33 , of congruent LiNbO 3 crystals doped with di-, tri- and hexa-valent cations is reported. It has been found that the referred parameters show a clear concentration singularity depending on the valency of the cation. A charge compensation mechanism is proposed to explain the role of the cation. The experimental data of n o and n e are described by a generalised Sellmeier equation considering the different ions sites in the crystal