The heavy atom effect on photocleavage of DNA by mono-hydroxyl halogenated corroles

<正>DNA photocleavage properties of halogenated mono-hydroxyl corrole 1-5 were investigated.It was found that these corroles were able to photocleavage supercoiled pBR 322 DNA(SC) into nicked-circular DNA(NC).The activity of these corroles follows an order of 432≈15.The photosensitized singlet oxygen(Φ_△) quantum yield by these corroles also follows that same order,showing the photocleavage activity is related to the heavy atom effect of halogen atoms on corroles.     

Copper(I)-catalyzed asymmetric alkene aziridination mediated by PhI(OAc)2: a facile one-pot procedure

A facile one-pot procedure for copper-catalyzed PhI(OAc)₂-mediated asymmetric alkene aziridination had been developed. Commercially available PhI(OAc)₂ and sulfonamides were used to generate the nitrene precursors (PhINR) in situ for olefin aziridination. This one-pot procedure had been optimized using 4-nitrobenzenesulfonamide as the nitrene source. With 5 mol % of the chiral copper catalyst, these conditions afforded 94% yield of the isolated product with 75% ee. We had also developed a simple and rapid method to monitor the rate of this one-pot aziridination.     

Conditions under which the order of two non-negative Hermitian matrices is preserved when taking integral powers

Let A and B be two n×n non-negative matrices. We write A ? B iff

$\text{u}{}^1\text{(A ? B)u ? 0}$

for all column vectors u in Cⁿ. Here u¹ is the conjugate transpose of u. In this paper are stated equivalent conditions under which A^k ? B^k for all natural numbers k. The result is then generalized to Hermitian operators in a Hilbert space.     

Determination of catechins and catechin gallates in biological fluids by HPLC with coulometric array detection and solid phase extraction

Tea polyphenols are well known for their beneficial health effects that involve their anti-carcinogenic, anti-mutagenic, anti-pathogenic and anti-oxidative properties. The main polyphenols of green tea are favan-3-ols (catechins) and their corresponding gallate compounds, which constitute about one-third of the dry weight of tea leaves. Their main ingredients are (+)-catechin (C), (−)-epicatechin (EC), (−)-gallocatechin (GC), (−)-epigallocatechin (EGC), (−)-catechin gallate (CG), (−)-epicatechin gallate (ECG), (−)-gallocatechin gallate (GCG) and (−)-epigallocatechin gallate (EGCG). Each has slightly different biological properties. We have developed a method to simultaneously analyze all these compounds in plasma and urine. The samples were first incubated with β-d-glucuronidase and sulfatase to release the catechin residues from their corresponding conjugates for subsequent extraction by selective solid phase column, Waters Oasis HLB extraction cartridges. The extracted molecules were resolved by reversed phase HPLC and monitored by coulometric chemical detection on a CoulArray detector. All eight catechin compounds were analyzed in a single chromatogram within 25 min. For plasma and urine analyses, good linearity (>0.9950) was validated in the range 10-2000 and 10-5000 ng/ml, respectively. The coefficients of variance (CV) were less than 5%. Absolute recovery was greater than 85% and detection limit was 5 ng/ml. The chromatogram exhibited minimal interference as a result of the highly selective solid phase extraction and CoulArray detection.     

Reference material for radionuclides in sediment IAEA-384 (Fangataufa Lagoon sediment)

A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (⁴⁰K, ⁶⁰Co, ¹⁵⁵Eu, ²³⁰Th, ²³⁸U, ²³⁸Pu, ^239+240Pu and ²⁴¹Am). Information values are given for 12 radionuclides (⁹⁰Sr, ¹³⁷Cs, ²¹⁰Pb (²¹⁰Po), ²²⁶Ra, ²²⁸Ra, ²³²Th, ²³⁴U, ²³⁵U, ²³⁹Pu, ²⁴⁰Pu and ²⁴¹Pu). Less reported radionuclides include ²²⁸Th, ²³⁶U, ²³⁹Np and ²⁴²Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units. Retired from IAEA in 2003.     

Liquid scintillation spectrometry of beta-emitters in marine samples

Liquid scintillation spectrometry has become the most widespread method for quantitative analysis of low level -emitters in environmental samples. This technique has been applied in the measurements of ²⁴¹Pu, ³H and ⁹⁰Sr in seawater and sediment samples. ²⁴¹Pu can be measured by direct analysis of an electrodeposited source using - discrimination or by extraction of electrodeposited plutonium into a liquid form compatible with scintillation cocktail. Sediment from Mururoa and Fangataufa atolls showed activities ranging from 18 to 44 Bq/kg. A sediment profile sampled around Bikini Atoll in 1997 showed ²⁴¹Pu activities ranging from 0.3 to 30 Bq/kg. ³H activities in pore water sediment from Mururoa and Fangataufa atolls were of the order of 10³ Bq/m³ which demonstrated its underground origin. ⁹⁰Sr was measured in the presence of ⁹⁰Y. The counting efficiency was 92.41.5% and the background 0.027±0.001 s^-1. The average chemical recovery for ⁹⁰Sr was 673%.     

Catalytic Phosphination and Arsination

The catalytic, user-friendly phosphination and arsination of aryl halides and triflates by triphenylphosphine and triphenylarsine using palladium catalysts have provided a facile synthesis of functionalized aryl phosphines and arsines in neutral media. Modification of the cynaoarisne yielded optically active N, As ligands which will be screened in various asymmetric catalysis.     

Rheological parameters analysis: Different technical approach

Conclusion In clinical states, we did not found any correlation between the techniques using these two viscometers which appear complementary; probably in erythrocyte dysfunction, they allow a better approach of the environment and the influence, in some cases, of plasmatic factors upon erythrocyte deformability. From this point of view, we actually consider that different techniques are necessary to establish in vitro a schedule of rheological behavior.

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Analyse von rheologischen Parametern: verschiedene Techniken

     

Rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction

An interesting rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction was developed. A chiral atropisomeric dipyridyldiphosphane ligand was found to be highly effective in this system. This operationally simple protocol allows both catalyst and reactants to be handled under air without precautions. Various enynes were transformed to the corresponding bicyclic cyclopentenones in good yield and enantiomeric excess (up to 95 % ee). A study of the electronic effects of the enyne substrates revealed a correlation between the electronic properties of the substrates and the ee value obtained in the product of the Pauson-Khand-type reaction. A linear free-energy relationship was observed from a Hammett study.     

Improvement of the efficiency of phthalocyanine organic Schottky solar cells with ITO electrode treatment

The devices investigated in this work consisted of an indium tin oxide (ITO)-coated glass substrate, phthalocyanine (Pc) layer and an aluminum electrode. The Schottky cell exhibits optimal performance with one ohmic and one barrier contact. The work function of the ITO film is typically around 4.5–4.8 eV, while the HOMO level of phthalocyanine films is typically around 5.2 eV. It is known that surface treatment of ITO can change its work function. We investigated various ITO surface treatments for improving the performance of phthalocyanine-based Schottky solar cells. We found that cells of ITO treated with HCl and UV ozone exhibited the best performance. Four different phthalocyanines (Pcs), namely nickel phthalocyanine (NiPc), copper phthalocyanine (CuPc), iron phthalocyanine (FePc) and cobalt phthalocyanine (CoPc) were investigated. A power conversion efficiency as high as 10% was achieved for the CuPc cell with monochromatic excitation at 632.8 nm, with a light intensity of 2.7 W/cm². PACS 72.40.+w; 73.61.Ph