DMF as an amine source: iron-catalyzed cyclization of 2-azirines to imidazoles.

A novel method has been developed for the synthesis of 1-methyl-4,5-diaryl-1-imidazoles through Fe(II)-catalyzed cyclization of 2-azirines and ,-dimethylformamide (DMF) as an amine source. This transformation involves the cleavage of C-N and CN double bonds and the construction of new C-N and CN double bonds. The reaction has readily available starting materials, a wide range of substrates and mild reaction conditions.

[Response of Soil Nitrifier and Denitrifier Community and Activity to Elevated Atmospheric CO Concentration and Temperature].

Elevated atmospheric CO concentration and temperature may affect nitrifiers and denitrifiers which are related to soil N turnover. A climate change experiment was conducted in the rice-wheat rotation ecosystem. This study was used to investigate effects of elevated CO and temperature on soil microbial community structure, as well as abundance and activity of nitrifiers and denitrifiers.

A Colorimetric and Fluorescent Sensor for Iron Recognition Based on Rhodamine Derivative.

A novel rhodamine based fluorescent sensor, L, was developed and investigated as a colorimetric and fluorescent sensor for Fe in dimethyl sulfoxide. The compound L showed a good selectivity and sensitivity toward Fe in the presence of large excess of other competitive ions. L can be used as a colorimetric and fluorescent sensor for Iron recognition in potential.

A novel rosamine based fluorescent sensor for Ag(+) recognition.

Rosamine derivative, N-(9-(4-(bis(2-(ethylthio)ethyl)amino)phenyl)-6-(diethylamino)-3H-xanthen-3-ylidene)-N-ethylethanaminium hexafluorophosphate, L, bearing an NS2 group as receptor, was synthesized as a turn on chemosensor for silver ion in ethanol solution. Sensor L exhibited high selectivity toward Ag(+) in comparison to other metal cations (Cd(2+), Cu(2+), Hg(2+), Na(+), Mg(2+), Ni(2+), Pb(2+), Fe(3+), and Zn(2+)). The detection limit for Ag(+) was in 10(-7) level.

A highly selective turn on fluorescence sensor for Hg2+ based on rhodamine derivative.

A novel fluorescent rhodamine based chemosensor (E)-3',6'-bis(diethylamino)-2-((2-(pyridin-2-ylmethoxy)benzylidene)amino)spiro[isoindoline-1,9'-xanthen]-3-one, RSP, had been successfully developed and well characterized by NMR, FT-IR and Mass spectroscopy. The chemosensor exhibits high selectivity for Hg(2+) over other ions (Ag(+), Pb(2+), Cu(2+), Ni(2+), Fe(3+), Co(2+), Zn(2+) and Cd(2+)) with fluorescence enhancement in ethanol solution. More over the detection limit of the sensor is in the 10(-6) M level.

Novel rhodamine derivate as high selective detection lead sensor.

A novel rhodamine based sensor 1 has been synthesized and characterized by NMR, FT-IR and mass. The binding properties of sensor 1 were investigated in the presence of various metal ions by UV-Vis spectroscopy and fluorescence spectroscopy. Sensor 1 showed colorimetric and high emission intensity enhancement in the presence of Pb(2+) in chloroform-THF (7:3).

A Selective Fluorescent Sensor for Hg(2+).

A novel rhodamine based fluorescent chemosensor RQP was prepared and characterized by (1)HNMR, (13)CNMR and HR-MS. The properties of RQP were studied through UV-Vis spectroscopy and fluorescence spectroscopy. RQP showed highly selectivity toward Hg(2+) over other metal ions, including Ag(+), Cd(2+), Cu(2+), Na(+), Mg(2+), Ni(2+), Pb(2+), Fe(3+), and Zn(2+) in aqueous solutions.

[Screening of the binding peptides of Mycobacterium tuberculosis H(37)Rv].

Objective: To screen the Mycobacterium tuberculosis H(37)Rv binding peptide using phage-displayed random peptide libraries, and to analyze the binding capacity of the peptide with Mycobacterium tuberculosis.

Methods: Inactive Mycobacterium tuberculosis H(37)Rv was used for screening of the binding peptide from the Ph.D.

[Fine root biomass and its nutrient storage in karst ecosystems under different vegetations in Central Guizhou, China].

The degeneration of karst ecosystem is closely associated with the reduction of soil nutrients and fine root biomass, and the retention of soil nutrients is of significance in sustaining ecosystem functioning. To understand the changes in the fine root biomass and soil nutrient retention in degenerated karst ecosystems, a comparative study was conducted with three typical vegetation stands (forest, shrub, and shrub-grass) in Central Guizhou of Southwest China. Soil samples with fine roots were collected from the depths 0-5 cm, 5-10 cm, and 10-15 cm, with the related indices of fine roots and nutrients measured.

Changes in cropland topsoil organic carbon with different fertilizations under long-term agro-ecosystem experiments across mainland China.

Topsoil soil organic carbon (SOC) data were collected from long-term Chinese agro-ecosystem experiments presented in 76 reports with measurements over 1977 and 2006. The data set comprised 481 observations (135 rice paddies and 346 dry croplands) of SOC under different fertilization schemes at 70 experimental sites (28 rice paddies and 42 dry croplands). The data set covered 16 dominant soil types found in croplands across 23 provinces of mainland China.

[Effects of heavy metals pollution on paddy soil aggregates composition and heavy metals distribution].

Topsoil samples were collected from a polluted and an adjacent non-polluted paddy field in the Taihu Lake region of China. Different particle size fractions of soil aggregates were separated by low-energy dispersion procedure, and their mass composition and Pb, Cd, Hg, and As concentrations were determined. Under heavy metals pollution, the mass composition of sand-sized fractions reduced, while that of clay-sized fractions increased.

[Responses of enzyme activities in different particle-size aggregates of paddy soil in Taihu Lake region of China to long-term fertilization].

Taking a long-term fertilized paddy soil in Taihu Lake region as research object, the enzyme activities in <2, 2-20, 20-200, and 200-2000 microm aggregates under no fertilization (NF), chemical fertilization (CF), chemical fertilization plus straw return (CFS), and chemical fertilization plus pig manure (CFM) were investigated. Fertilization promoted the formation of 200-2000 microm aggregates significantly. The enzyme activities differed with aggregates' particle-size.

Two-step scheme for rapid identification and differentiation of Legionella pneumophila and non-Legionella pneumophila species.

A rapid two-step scheme based on PCR amplification and enzymatic digestion analysis of a 226-bp fragment of the 16S rRNA gene was developed to identify the Legionella genus by PCR amplification and to differentiate the Legionella pneumophila and non-Legionella pneumophila species by enzymatic digestion analysis. Among 42 ATCC strains (16 strains of L. pneumophila and 26 strains of non-L.

[Variation of Cd, Zn and Se contents of polished rice and the potential health risk for subsistence-diet farmers from typical areas of South China].

In this study, a total of 70 polished rice samples were randomly collected at agro-product markets from some typical regions of South China. Their contents of Cd, Zn and Se were determined by atomic adsorption spectrophotometers (AAS) and atomic fluorescence spectrometry (AES) respectively. The variation of the contents with rice areas was described in terms of soil conditions and the potential health risk by food exposure to these rice rains for subsistence-diet fanners is discussed.

Evolutional selection of a combinatorial phage library displaying randomly-rearranged various single domains of immunoglobulin (Ig)-binding proteins (IBPs) with four kinds of Ig molecules.

Background: Protein A, protein G and protein L are three well-defined immunoglobulin (Ig)-binding proteins (IBPs), which show affinity for specific sites on Ig of mammalian hosts. Although the precise functions of these molecules are not fully understood, it is thought that they play an important role in pathogenicity of bacteria. The single domains of protein A, protein G and protein L were all demonstrated to have function to bind to Ig.

Topsoil organic carbon mineralization and CO2 evolution of three paddy soils from South China and the temperature dependence.

Carbon mineralization and its response to climatic warming have been receiving global attention for the last decade. Although the virtual influence of temperature effect is still in great debate, little is known on the mineralization of organic carbon (SOC) of paddy soils of China under warming. SOC mineralization of three major types of China's paddy soils is studied through laboratory incubation for 114 d under soil moisture regime of 70% water holding capacity at 20 degrees C and 25 degrees C respectively.

[Detection of diarrheagenic escherichia coil harboring genomic O island 28 isolated from children diarrhea in Taiyuan].

Objective: To investigate the etiologic value of diarrheagenic E. coil harboring genomic O island 28(OI-28) containing five putative virulence genes (Z0608, Z0609, Z0615, Z0634 and Z0635), which were related to RTX (Repeat in toxin) toxin family isolated from children with diarrheal disease in Taiyuan.

Methods: In the study, 257 fecal samples from children with diarrheal disease collected in Shanxi Children's Hospital.

Distribution of Cu and Pb in particle size fractions of urban soils from different city zones of Nanjing, China.

Soil samples from 4 defined city zones of Nanjing were randomly collected at 0-5 cm and 5-20 cm intervals and size fractions of soil particles were separated from undisturbed bulk soils by low energy dispersion procedure. The total contents of Cu and Pb in the different particle size fractions of the urban soils were analyzed by HNO3-HF-HClO4 digestion and flame atomic absorption spectrophotometer determination. The total content of Cu and Pb in soil particle size fractions varied with their size and with city zones as well.

[Cd uptake and accumulation in grains by hybrid rice in two paddy soils: interactive effect of soil type and cultivars].

Cd translocation through soil-food crop-diet is considered as one of most important pathway for human Cd exposure. Rice is considered as a particular crop with high Cd uptake and accumulation in grains among the main food crops. In this study, a pot experiment was conducted to elucidate mutual interaction of soil and cultivars on uptake and grain accumulation of Cd by hybrid rice with or without Cd spiking at 2.

[Effect of submerging and wetting-redrying on Cd speciation and uptake by Sorghum hybrid Sudangrass in two paddy soils under spiked Cd].

Effect of continuous submerging and wetting-redrying on cadmium speciation and uptake by Sorghum hybrid Sudangrass in a Ferric-accumulic Stagnic Anthrosol and a Tipical Hapludult collected from the Taihu Lake region and the rolling downs of Yingtan, Jiangxi, China respectively, was studied by pot experiment with Cd spike in 2003. Compared to that under wetting-redrying treatment, the MgCl2-extracted pool of Cd in Huangnitu with spiked Cd of 5mg x kg(-1) and 10mg x kg(-1) was decreased from 21.8% and 28.

Two new borates containing the first examples of large isolated polyborate anions: chain [B7O9(OH)5]2- and ring [B14O20(OH)6]4-.

Two novel hydrated borates were synthesized under mild solvothermal conditions. One is hydrated rubidium borate, Rb2B7O9(OH)5, which contains the first example of the isolated chain heptaborate anion, [B7O9(OH)5]2-. The other is hydrated diethylenetriamine borate, [(C4H15N3)]2[B14O20(OH)6], which contains the first example of the largest isolated ring tetradecaborate anion, [B14O20(OH)6]4-.

[Association of vitamin D receptor gene Apa I polymorphism with vitamin D deficiency rickets].

Objective: To study the association between vitamin D receptor (VDR) gene Apa I polymorphism and vitamin D deficiency rickets in children of Shanxi Han ethnic group, and to explore the significance of individual hereditary factors in the development of rickets.

Methods: This was a case control study. The grouping criteria were serum 25(OH)D(3) level, blood bone alkaline phosphatase and clinical symptom, respectively.

Organic carbon stock in topsoil of Jiangsu Province, China, and the recent trend of carbon sequestration.

Data collection of soil organic carbon(SOC) of 154 soil series of Jiangsu, China from the second provincial soil survey and of recent changes in SOC from a number of field pilot experiments across the province were collected. Statistical analysis of SOC contents and soil properties related to organic carbon storage were performed. The provincial total topsoil SOC stock was estimated to be 0.