Two dimensional nuclear magnetic resonance analysis of bis(2,2 '-bipyridine)(2,2 '-bipyridine-4,4 '-dicarboxylic acid)ruthenium(II) hexafluorophosphate

The H-1 and C-13 nuclear magnetic resonance(NMR) spectra are reported for bis(2, 2'-bipyridine)(2, 2'-bipyridine-,4,4'-dicarboxylic acid) ruthenium(II) hexafluoruphosphate that has been used as a tagged molecule of electrochemiluminescent immunoassay. Because of the effect of Ru atom on ligands, it is difficult to assign its NMR spectra. BS' means of two dimensional H-1-H-1 COSY and H-1-C-13 COSY techniques, the H-1 and C-13 NMR spectra of bis (2, 2'-bipylidine) (2, 2'-bipyridine-4, 4-dicarboxylic acid) ruthenium(II) hexafluorophosphate are assigned completely. This provides a basis for NMR characterization of the nerv similar tagged molecules.

Analysis of 2D-nuclear magnetic resonance for Ru(2,2 '-bipyridine)(2)(4,4 '-dimethyl-2,2 '-bipyridine) (PF6)(2)

The H-1 and C-13 NMR spectra are reported for Ru(2,2'-bipyridine)(2)(4,4'-dimethyl-2,2'-bipyridine)(PF6)(2) that may be used as elechochemiluminescent species. Because of the effect of Ru atom on ligands and complex steric configuration, it is, difficult to attribute the spectra of the title molecular. By using 2D H-1-H-1 COSY and H-1-C-13 COSY methods, the proton and carbon-13 spectra are assigned completely. This also provides a basis for NMR characterization of the-similar new compounds.

Nuclear magnetic resonance spectral assignments of 2,2 '-bis(p-aminobenzoic ester)-1,1 '-binaphthyl

H-1 and C-13 nuclear magnetic resonance (NMR) spectra of 2, 2'-bis(p-aminobenzoic ester)-1,1'-binaphthyl were assigned and confirmed using 2D H-1-H-1 COSY, C-13-H-1 HETCOR and C-13-H-1 long-range HETCOR methods. This provided a basis for NMR characterization of the similar compounds.

INVESTIGATION OF PHASE SEPARATION BEHAVIOR IN POLY (METHYL METHACRYLATE)/POLY (STYRENE-CO-ACRYLONITRILE) MIXTURES WITH PULSED NUCLEAR MAGNETIC RESONANCE

Thermally induced phase separation in the mixture of poly (methyl methacrylate) (PMMA) with poly(styrene-co-acrylonitite (SAN) has intern studied with pulsed nuclear magnetic resonance(NMR) in single spin-lattice retaxation time T-1 of the eornpatibl. mixture two T-1 corresponding to those of PM MA-rich and SAN-rich comairis. Meanwhile, both T-1 gradually changing with annealing time provides the direct evidence that the phase separation takes place with a decomposition mechanism. Diffusion coeffieient was to lac negative, indicating an uphal diffusion characteristics, The basic parameters governing its kinetics were estimated using NMR date which were in good agreement with those evaluated from time-resolved light scattering experiments for a 60/40(PMMA/SAN) mixture annealed at 180.0 degrees C.

Phylogeography of the Northern Atlantic species Chondrus crispus (Gigartinales, Rhodophyta) inferred from nuclear rDNA internal transcribed spacer sequences

Eighteen isolates of the red algae Chondrus crispus were collected from Northern Atlantic sites, together with C. ocellatus, C. yendoi and C. pinnulatus from the North Pacific. The nuclear rDNA internal transcribed spacer (ITS) was sequenced and compared, spanning both the ITS regions and the 5.8S rRNA gene. Percentage of nucleotide variation for C. crispus ranged from 0.3% to 4.0%. Phylogenetic analyses were performed using maximum parsimony (MP), neighbor-joining (NJ) and minimum evolution methods. They showed that two main clades existed within the C. crispus samples examined and that suggested C. crispus had a single Atlantic origin. The clustering however did not follow the geographic origin. We hypothesized that the current distribution of C. crispus populations might be a result of three main factors: temperature boundaries, paleoclimate and paleoceanography. ITS data exhibited abundant molecular information not only for phylogeographical investigation but also for systematics studies.

Molecular cloning and characterization of proliferating cell nuclear antigen (PCNA) from Chinese shrimp Fenneropenaeus chinensis

The proliferating cell nuclear antigen gene was cloned from Fenneropenaeus chinensis (FcPCNA). The full-length cDNA sequence of FcPCNA encodes 260 amino acids showing high identity with PCNAs reported in other species. FcPCNA expressed especially high in proliferating tissues of shrimp such as haematopoietic tissue (HPT) and ovary. In order to understand the response of HPT to bacteria and virus challenge, mRNA level of FcPCNA in HPT was analyzed after shrimp were challenged by Vibrio anguillarum and white spot syndrome virus (WSSV). FcPCNA expression in HPT of shrimp was responsive to WSSV and Vibrio challenge, but different expression profiles were obtained after challenge by these two pathogens. The data provide additional information to understand the defense mechanisms of shrimp against virus and bacteria. (c) 2008 Elsevier Inc. All rights reserved.

Ulva and Enteromorpha (Ulvaceae, Chlorophyta) from two sides of the Yellow Sea: analysis of nuclear rDNA ITS and plastid rbcL sequence data

Ulvacean green seaweeds are common worldwide; they formed massive green tides in the Yellow Sea in recent years, which caused marine ecological problems as well as a social issue. We investigated two major genera of the Ulvaceae, Ulva and Enteromorpha, and collected the plastid rbcL and nuclear ITS sequences of specimens of the genera in two sides of the Yellow Sea and analyzed them. Phylogenetic trees of rbcL data show the occurrence of five species of Enteromorpha (E. compressa, E. flexuosa, E. intestinalis, E. linza and E. prolifera) and three species of Ulva (U. pertusa, U. rigida and U. ohnoi). However, we found U. ohnoi, which is known as a subtropical to tropical species, at two sites on Jeju Island, Korea. Four ribotypes in partial sequences of 5.8S rDNA and ITS2 from E. compressa were also found. Ribotype network analysis revealed that the common ribotype, occurring in China, Korea and Europe, is connected with ribotypes from Europe and China/Japan. Although samples of the same species were collected from both sides of the Yellow Sea, intraspecific genetic polymorphism of each species was low among samples collected worldwide.

No C_4 Plants Found at the Haibei Alpine Meadow Ecosystem Research Station in Qinghai, China: Evidence from Stable Carbon Isotope Studies

Using the measurement of stable carbon isotopes in leaves as a tool to investigate photosyn-thetic pathway of 102 plant species grown at an alpine meadow ecosystem, at the foot of the Qilian Mountain, Qinghai, China. The results indicate that the δ~(3)C values of plants have a narrow range from -28.24‰ to -24.84‰, which means that none of the species examined belongs to C_4 and crassulaceous acid metabolism (CAM) photosynthetic pathway and all of these species perform photosynthesis through the C_3 pathway. This is likely due to a long-term adaptation to environments at the alpine meadow ecosystem.

Molecular systematics and biogeography of Crawfurdia, Metagentiana and Tripterospermum (Gentianaceae) based on nuclear ribosomal and plastid DNA sequences

Background and Aims The systematic position of the genus Metagentiana and its phylogenetic relationships with Crawfurdia, Gentiana and Tripterospermum have not been explicitly addressed. These four genera belong to one of two subtribes (Gentianinae) of Gentianeae. The aim of this paper is to examine the systematic position of Crawfurdia, Metagentiana and Tripterospermum and to clarify their phylogenetic affinities more clearly using ITS and trnL intron sequences.Methods Nucleotide sequences from the internal transcribed spacers (ITS) of nuclear ribosomal DNA and the plastid DNA trnL (UAA) intron were analysed phylogenetically. Ten of fourteen Metagentiana species were sampled, together with 40 species of other genera in the subtribe Gentianinae.Key Results The data support several previously published conclusions relating to the separation of Metagentiana from Gentiana and its closer relationships to Crawfurdia and Tripterospermum based on studies of gross morphology, floral anatomy, chromosomes, palynology, embryology and previous molecular data. The molecular clock hypothesis for the tested sequences in subtribe Gentianinae was not supported by the data (P < 0.05), so the clock-independent non-parametric rate smoothing method was used to estimate divergence time. This indicates that the separation of Crawfurdia, Metagentiana and Tripterospermum from Gentiana occurred about 11.4-21.4 Mya (million years ago), and the current species of these three genera diverged at times ranging from 0.4 to 6.2 Mya.Conclusions The molecular analyses revealed that Crawfurdia, Metagentiana and Tripterospermum do not merit status as three separate genera, because sampled species of Crawfurdia and Tripterospermum are embedded within Metagentiana. The speciation and rapid radiation of these three genera is likely to have occurred in western China as a result of upthrust of the Himalayas during the late Miocene and the Pleistocene.

Ecological basis of Alpine meadow ecosystem management in Tibet: Haibei Alpine Meadow Ecosystem Research Station

Alpine meadow and shrub are the main pasture types on the Tibetan Plateau, and they cover about 35% of the total land area. In order to understand the structural and functional aspects of the alpine ecosystem and to promote a sustainable animal production system, the Haibei Alpine Meadow Research Station was established in 1976. A series of intensive studies on ecosystem structure and function, including the energy flow and nutrient cycling of the ecosystem, were the main tasks during the first 10 years. Meanwhile, studies with 5 different grazing intensities on both summer and winter pasture have been conducted. In the early years of the 1990s, the research station started to focus its research work on global warming, biodiversity and sustainable animal production systems in pastoral areas. Various methods for improving degraded pasturelands have been developed in the region.