A new magnesium borate MgO·3B 2 O 3 ·3.5H 2 O has been synthesized by the method o f phase transformation of 2MgO·2B 2 O 3 ·MgCl 2 ·14H 2 O in boric acid solution and characte rized by XRD,FT-...A new magnesium borate MgO·3B 2 O 3 ·3.5H 2 O has been synthesized by the method o f phase transformation of 2MgO·2B 2 O 3 ·MgCl 2 ·14H 2 O in boric acid solution and characte rized by XRD,FT-IR and Raman spectra as well as by TG.The structural formula of this compound was Mg[B 6 O 9 (OH) 2 ]·2.5H 2 O.The main polyborate anions and their interaction in borate aqueous solution of preparation reactio n have been proposed according to the Raman spectrum of borate solution.The relation between the existing forms of polyborate anions and the crystalliz ing solid phase has been gained.展开更多
In order to investigate molecular phylogenetic relationships of Drosophila immigransspecies group,nucleotide sequences of H2a-H2b spacer regions and partial nucleotide sequences of Cytochrome b gene for five specieses...In order to investigate molecular phylogenetic relationships of Drosophila immigransspecies group,nucleotide sequences of H2a-H2b spacer regions and partial nucleotide sequences of Cytochrome b gene for five specieses subgroup in Drosophila immigrans species group and D.hydei which was selected as outgroup were acquired. Phylogenetic trees were reconstructed using maximum parsimony,maximum likelihood,neighbor joining and Bayesian methods based on H2a-H2b and Cyt b DNA sequences. The results indicated that Drosophila curviceps species subgroup is located at the base of molecular trees, diverged first in this group; the second clade is Drosophila quadrilineata species subgroup; the third is Drosophila hypocausta species subgroup; the fourth is Drosophila immigrans species subgroup; Drosophila nasuta species subgroup is the last diverged clade. Moreover,the phylogentic relationships of seven specieses in Drosophila nasuta subgroup was investigated.展开更多
With the identification of increasing number of chromatin modifiers, histone variants, histone post-translational modifications and their cross-talk, it is essential to validate these findings and interactions in vitr...With the identification of increasing number of chromatin modifiers, histone variants, histone post-translational modifications and their cross-talk, it is essential to validate these findings and interactions in vitro for which pure histone complexes are required. Although, the production of such complexes has been described earlier but still it remains a challenge for a non-specialist lab. Here we describe a protocol to quickly obtain large quantities of highly pure histones using bacterial expression system for GST pull-down and reconstitution experiments. In addition, we describe methods to quickly reconstitute and purify H2A/H2B dimers, H3/H4 tetramers and histone octamers for in vitro experiments. We demonstrate that these sub-complexes are properly folded and are hence, true representatives of the actual substrates in vivo. We also show that histones have a propensity to be non-specifically cleaved by proteases. Our results suggest that TEV protease is the most suitable protease while working with histones. The methodology described here should allow researchers to purify histone complexes in three days enabling functional and structural analyses of histone variants, mutants and post-translational modifications.展开更多
1 Introduction Chabocuo Lake is located in the territory of Gaize County Ali area Tibet,the altitude of the lake-surface is4505 m with a total area of 32 Km2.It is a typical sulfate type saline and rich in boron and l...1 Introduction Chabocuo Lake is located in the territory of Gaize County Ali area Tibet,the altitude of the lake-surface is4505 m with a total area of 32 Km2.It is a typical sulfate type saline and rich in boron and lithium.In the natural evaporation process,several mineral sylvites cocrystallize out,thus increases the difficulties for separating and展开更多
文摘A new magnesium borate MgO·3B 2 O 3 ·3.5H 2 O has been synthesized by the method o f phase transformation of 2MgO·2B 2 O 3 ·MgCl 2 ·14H 2 O in boric acid solution and characte rized by XRD,FT-IR and Raman spectra as well as by TG.The structural formula of this compound was Mg[B 6 O 9 (OH) 2 ]·2.5H 2 O.The main polyborate anions and their interaction in borate aqueous solution of preparation reactio n have been proposed according to the Raman spectrum of borate solution.The relation between the existing forms of polyborate anions and the crystalliz ing solid phase has been gained.
文摘In order to investigate molecular phylogenetic relationships of Drosophila immigransspecies group,nucleotide sequences of H2a-H2b spacer regions and partial nucleotide sequences of Cytochrome b gene for five specieses subgroup in Drosophila immigrans species group and D.hydei which was selected as outgroup were acquired. Phylogenetic trees were reconstructed using maximum parsimony,maximum likelihood,neighbor joining and Bayesian methods based on H2a-H2b and Cyt b DNA sequences. The results indicated that Drosophila curviceps species subgroup is located at the base of molecular trees, diverged first in this group; the second clade is Drosophila quadrilineata species subgroup; the third is Drosophila hypocausta species subgroup; the fourth is Drosophila immigrans species subgroup; Drosophila nasuta species subgroup is the last diverged clade. Moreover,the phylogentic relationships of seven specieses in Drosophila nasuta subgroup was investigated.
文摘With the identification of increasing number of chromatin modifiers, histone variants, histone post-translational modifications and their cross-talk, it is essential to validate these findings and interactions in vitro for which pure histone complexes are required. Although, the production of such complexes has been described earlier but still it remains a challenge for a non-specialist lab. Here we describe a protocol to quickly obtain large quantities of highly pure histones using bacterial expression system for GST pull-down and reconstitution experiments. In addition, we describe methods to quickly reconstitute and purify H2A/H2B dimers, H3/H4 tetramers and histone octamers for in vitro experiments. We demonstrate that these sub-complexes are properly folded and are hence, true representatives of the actual substrates in vivo. We also show that histones have a propensity to be non-specifically cleaved by proteases. Our results suggest that TEV protease is the most suitable protease while working with histones. The methodology described here should allow researchers to purify histone complexes in three days enabling functional and structural analyses of histone variants, mutants and post-translational modifications.
文摘1 Introduction Chabocuo Lake is located in the territory of Gaize County Ali area Tibet,the altitude of the lake-surface is4505 m with a total area of 32 Km2.It is a typical sulfate type saline and rich in boron and lithium.In the natural evaporation process,several mineral sylvites cocrystallize out,thus increases the difficulties for separating and
