| 95 matches found in 55 documents. Search time: 0.154 seconds. |
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Score: 8.00 |
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| Title: Kinetics of C60 fullerene dispersion in water enhanced by natural organic matter and sunlight .
| | Author: Li Q Xie B Hwang YS Xu Y | | Journal: Environ Sci Technol Citation: V : 43 P : 3574-9 . Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19544857 Accession (PMID): 19544857 | | Abstract: The industrial-scale production of Buckminster fullerene C60 elicits concerns over its impact on human health and ecosystems because of the reported , albeit debatable , toxicity .
Assessment of the overall environment risk requires a good estimate of the level of exposure and careful characterization of the physicochemical properties of C60 in natural aqueous environments .
The reported study investigates the role of various environmental factors , ie , ionic composition , natural organic matter ( NOM ) , and light in dispersion of C60 in the aqueous phase by simple mixing .
The presence of NOM greatly enhances C60 dispersion , and the dispersion process is further accelerated by sunlight .
At typical NOM concentrations found in natural waters , C60 concentrations of a few to tens of milligrams per liter can occur within 10 days of mixing , regardless of its extremely low water solubility .
The rate of dispersing decreases with the increase of ionic strength .
However , calcium ions significantly increase C60 concentration in the aqueous phase .
Results from UV/vis absorbance characterization strongly suggest that C60 may have been chemically modified when dispersed in an NOM solution in the presence of sunlight .
This reaction pathway has significant implication on the fate , transport , and environmental impact of C60 fullerene .
| Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: The industrial-scale production of Buckminster fullerene C60 elicits concerns over its impact on human health and ecosystems because of the reported , albeit debatable , toxicity .
[ Sen. 2, subscore: 1.00 ]: Assessment of the overall environment risk requires a good estimate of the level of exposure and careful characterization of the physicochemical properties of C60 in natural aqueous environments .
[ Sen. 3, subscore: 1.00 ]: The reported study investigates the role of various environmental factors , ie , ionic composition , natural organic matter ( NOM ) , and light in dispersion of C60 in the aqueous phase by simple mixing .
[ Sen. 4, subscore: 1.00 ]: The presence of NOM greatly enhances C60 dispersion , and the dispersion process is further accelerated by sunlight .
[ Sen. 5, subscore: 1.00 ]: At typical NOM concentrations found in natural waters , C60 concentrations of a few to tens of milligrams per liter can occur within 10 days of mixing , regardless of its extremely low water solubility .
[ Sen. 7, subscore: 1.00 ]: However , calcium ions significantly increase C60 concentration in the aqueous phase .
[ Sen. 8, subscore: 1.00 ]: Results from UV/vis absorbance characterization strongly suggest that C60 may have been chemically modified when dispersed in an NOM solution in the presence of sunlight .
[ Sen. 9, subscore: 1.00 ]: This reaction pathway has significant implication on the fate , transport , and environmental impact of C60 fullerene .
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Score: 7.00 |
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| Title: Computational study on the mechanism and rate constant for the C6H5 + C6H5NO reaction .
| | Author: Xu ZF Lin MC .
| | Journal: Citation: V : 109 ( 40 ) P : 9054-60 Year: 2005 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub16332011 Accession (PMID): 16332011 | | Abstract: The reaction mechanism of C6H5 + C6H5NO involving four product channels on the doublet-state potential energy surface has been studied at the B3LYP/6-31+G ( d , p ) level of theory .
The first reaction channel occurs by barrierless association forming ( C6H5 ) 2NO ( biphenyl nitroxide ) , which can undergo isomerization and decomposition .
The second channel takes place by substitution reaction producing C12H10 ( biphenyl ) and NO .
The third and fourth channels involve direct hydrogen abstraction reactions producing C6H4NO + C6H6 and C6H5NOH + C6H4 , respectively .
Bimolecular rate constants of the above four product channels have been calculated in the temperature range 300-2000 K by the microcanonical Rice-Ramsperger-Kassel-Marcus theory and/or variational transition-state theory .
The result shows the dominant reactions are channel 1 at lower temperatures ( T < 800 K ) and channel 3 at higher temperatures ( T > 800 K ) .
The total rate constant at 7 Torr He is predicted to be k ( t ) = 3 . 94 x 10 ( 21 ) T ( -3 . 09 ) exp ( -699/T ) for 300-500 K , 2 . 09 x 10 ( 20 ) T ( -3 . 56 ) exp ( 2315/T ) for 500-1000 K , and 1 . 51 x 10 ( 2 ) T ( 3 . 30 ) exp ( -3043/T ) for 1000-2000 K ( in units of cm3 mol ( -1 ) s ( -1 ) ) , agreeing reasonably with the experimental data within their reported errors .
The heats of formation of key products including biphenyl nitroxide , hydroxyl phenyl amino radical , and N-hydroxyl carbazole have been estimated .
| Matching Sentences:
[ Sen. 4, subscore: 4.00 ]: The third and fourth channels involve direct hydrogen abstraction reactions producing C6H4NO + C6H6 and C6H5NOH + C6H4 , respectively .
[ Sen. 1, subscore: 2.00 ]: The reaction mechanism of C6H5 + C6H5NO involving four product channels on the doublet-state potential energy surface has been studied at the B3LYP/6-31+G ( d , p ) level of theory .
[ Sen. 2, subscore: 1.00 ]: The first reaction channel occurs by barrierless association forming ( C6H5 ) 2NO ( biphenyl nitroxide ) , which can undergo isomerization and decomposition .
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Score: 7.00 |
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| Title: [ A new rice dwarf1 mutant caused by a frame-shift mutation ] .
| | Author: Chen HX Zhou CB Xing YZ | | Journal: Yi Chuan Citation: V : 33 P : 397-403 Year: 2011 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub21482531 Accession (PMID): 21482531 | | Abstract: A dwarf mutant C6PS , which has the similar phenotype as the recessive mutant Dwarf1 ( d1 ) , was produced from it issue-cultured plants of Zhonghua 11 .
In its progeny ( T2 ) , the ratio of tall to dwarf plants was in agreement with the expected segregation ratio ( 3 : 1 ) of a single Mendelian inheritance gene , which indicated that the variation of plant height is caused by a single gene .
To locate the mutation , C6PS was crossed with Zhenshan 97 and Mudanjiang 8 for producing two F2 populations of F2 ( CM ) and F2 ( CZ ) , respectively .
The plant height in each F2 population also showed the same segregation pattern as that in T2 generation .
SSR marker RM430 closely linked to Dwarf1 was preferentially used to genotype the F2 ( CZ ) population because C6PS showed the similar phenotype to d1 mutant .
RM430 was significantly associated with plant height , which indicated that the mutant gene might be D1 .
Comparative sequencing of D1 between C6PS and Zhonghua 11 showed a 6 bp deletion occurred in the splice site of its ninth exon .
The marker C6PS-D1L/R designed on the 6 bp deletion was co-segregated with plant height in T2 generation .
The results indicated that C6PS was a new mutant of D1 .
This mutation led to a 26 bp deletion of the transcript and resulted in a frame-shift mutation and a premature stop codon in C6PS , which could not translate the functional Galpha protein .
C6PS was weakly sensitive to Brassinolide based on the leaf inclination angle test | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: A dwarf mutant C6PS , which has the similar phenotype as the recessive mutant Dwarf1 ( d1 ) , was produced from it issue-cultured plants of Zhonghua 11 .
[ Sen. 3, subscore: 1.00 ]: To locate the mutation , C6PS was crossed with Zhenshan 97 and Mudanjiang 8 for producing two F2 populations of F2 ( CM ) and F2 ( CZ ) , respectively .
[ Sen. 5, subscore: 1.00 ]: SSR marker RM430 closely linked to Dwarf1 was preferentially used to genotype the F2 ( CZ ) population because C6PS showed the similar phenotype to d1 mutant .
[ Sen. 7, subscore: 1.00 ]: Comparative sequencing of D1 between C6PS and Zhonghua 11 showed a 6 bp deletion occurred in the splice site of its ninth exon .
[ Sen. 9, subscore: 1.00 ]: The results indicated that C6PS was a new mutant of D1 .
[ Sen. 10, subscore: 1.00 ]: This mutation led to a 26 bp deletion of the transcript and resulted in a frame-shift mutation and a premature stop codon in C6PS , which could not translate the functional Galpha protein .
[ Sen. 11, subscore: 1.00 ]: C6PS was weakly sensitive to Brassinolide based on the leaf inclination angle test
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Score: 5.00 |
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| Title: Comparative photoactivity and antibacterial properties of C60 fullerenes and titanium dioxide nanoparticles .
| | Author: Brunet L Lyon DY Hotze EM Alvarez PJ Wiesner MR | | Journal: Environ Sci Technol Citation: V : 43 P : 4355-60 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19603646 Accession (PMID): 19603646 | | Abstract: The production of reactive oxygen species ( ROS ) by aqueous suspensions of fullerenes and nano-TiO2 ( Degussa P25 ) was measured both in ultrapure water and in minimal Davis ( MD ) microbial growth medium .
Fullerol ( hydroxylated C60 ) produced singlet oxygen ( 1O2 ) in ultrapure water and both 1O2 and superoxide ( O2-* ) in MD medium , but no hydroxyl radicals ( OH* ) were detected in either case .
PVP/C60 ( C60 encapsulated with poly ( N-vinylpyrrolidone ) ) was more efficient than fullerol in generating singlet oxygen and superoxide .
However , two other aggregates of C60 , namely THF/nC60 ( prepared with tetrahydofuran as transitional solvent ) and aqu/nC60 ( prepared by vigorous stirring of C60 powder in water ) , were not photoactive .
Nano-TiO2 ( also present as aggregates ) primarily produced hydroxyl radicals in pure water and superoxide in MD medium .
Bacterial ( Escherichia coli ) toxicity tests suggest that , unlike nano-TiO2 which was exclusively phototoxic , the antibacterial activity of fullerene suspensions was linked to ROS production .
Nano-TiO2 may be more efficient for water treatment involving UV or solar energy , to enhance contaminant oxidation and perhaps for disinfection .
However , fullerol and PVP/ C60 may be useful as water treatment agents targeting specific pollutants or microorganisms that are more sensitive to either superoxide or singlet oxygen .
| Matching Sentences:
[ Sen. 4, subscore: 2.00 ]: However , two other aggregates of C60 , namely THF/nC60 ( prepared with tetrahydofuran as transitional solvent ) and aqu/nC60 ( prepared by vigorous stirring of C60 powder in water ) , were not photoactive .
[ Sen. 2, subscore: 1.00 ]: Fullerol ( hydroxylated C60 ) produced singlet oxygen ( 1O2 ) in ultrapure water and both 1O2 and superoxide ( O2-* ) in MD medium , but no hydroxyl radicals ( OH* ) were detected in either case .
[ Sen. 3, subscore: 1.00 ]: PVP/C60 ( C60 encapsulated with poly ( N-vinylpyrrolidone ) ) was more efficient than fullerol in generating singlet oxygen and superoxide .
[ Sen. 8, subscore: 1.00 ]: However , fullerol and PVP/ C60 may be useful as water treatment agents targeting specific pollutants or microorganisms that are more sensitive to either superoxide or singlet oxygen .
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Score: 5.00 |
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| Title: Characterization and mapping of cDNA encoding aspartate aminotransferase in rice , Oryza sativa L | | Author: Song J Yamamoto K Shomura A Yano M Minobe Y Sasaki T | | Journal: DNA Res .
Citation: V : 3 ( 5 ) P : 303-10 Year: 1996 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub9039500 Accession (PMID): 9039500 | | Abstract: Fifteen cDNA clones , putatively identified as encoding aspartate aminotransferase ( AST , EC 2 . 6 . 1 . 1 . ) , were isolated and partially sequenced .
Together with six previously isolated clones putatively identified to encode ASTs ( Sasaki , et al 1994 , Plant Journal 6 , 615-624 ) , their sequences were characterized and classified into 4 cDNA species .
Two of the isolated clones , C60213 and C2079 , were full-length cDNAs , and their complete nucleotide sequences were determined .
C60213 was 1612 bp long and its deduced amino acid sequence showed 88% homology with that of Panicum miliaceum L mitochondrial AST .
The C60213-encoded protein had an N-terminal amino acid sequence that was characteristic of a mitochondrial transit peptide .
On the other hand , C2079 was 1546 bp long and had 91% amino acid sequence homology with P miliaceum L cytosolic AST but lacked in the transit peptide sequence .
The homologies of nucleotide sequences and deduced amino acid sequences of C2079 and C60213 were 54% and 52% , respectively .
C2079 and C60213 were mapped on chromosomes 1 and 6 , respectively , by restriction fragment length polymorphism linkage analysis .
Northern blot analysis using C2079 as a probe revealed much higher transcript levels in callus and root than in green and etiolated shoots , suggesting it issue-specific variations of AST gene expression . | Matching Sentences:
[ Sen. 3, subscore: 1.00 ]: Two of the isolated clones , C60213 and C2079 , were full-length cDNAs , and their complete nucleotide sequences were determined .
[ Sen. 4, subscore: 1.00 ]: C60213 was 1612 bp long and its deduced amino acid sequence showed 88% homology with that of Panicum miliaceum L mitochondrial AST .
[ Sen. 5, subscore: 1.00 ]: The C60213-encoded protein had an N-terminal amino acid sequence that was characteristic of a mitochondrial transit peptide .
[ Sen. 7, subscore: 1.00 ]: The homologies of nucleotide sequences and deduced amino acid sequences of C2079 and C60213 were 54% and 52% , respectively .
[ Sen. 8, subscore: 1.00 ]: C2079 and C60213 were mapped on chromosomes 1 and 6 , respectively , by restriction fragment length polymorphism linkage analysis .
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