Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on dete...Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on determination of residual protein in lincomycin hydrochloride. Methods The chromatographic conditions were SuperdexTM peptide column, 0.01 mol*L-1 phosphate buffer solution as mobile phase, and flow rate of 1 mL·min-1. Five hundred microliters of lincomycin hydrochloride solution (3 g of lincomycin hydrochloride dissolved in 10 mL of mobile phase) was injected into the chromatograph and the eluted solution was collected between 6 min and 14.5 min (protein eluted from column within this period), and the residual content of total protein in the eluted solution was assayed using Bradford assay method. Results The average recovery was more than 90% for bovine serum albumin, the calibration equation for the range of 0-12 μg·mL-1 of protein was y=-0.002 4x2+0.064 2x+0.002 9, r2=0.999 9, RSD=0.1%-0.9%, and the LOD and LOQ were 3 and 10 ng·mL-1 of protein, respectively. Conclusion The novel method for determining the residual protein in ferment antibio-tics is simple, rapid, and precise.展开更多
[Objective]The aim was to study the effect of herbicide on the growth of early seedlings of rye（Secale cereale）.[Method]Effect of two kinds of herbicide（Atrazine and APM）on seedling growth of rye was investigated ...[Objective]The aim was to study the effect of herbicide on the growth of early seedlings of rye（Secale cereale）.[Method]Effect of two kinds of herbicide（Atrazine and APM）on seedling growth of rye was investigated at the physiological,biochemical and cellular level.[Result]The Atrazin significantly decreased the contents of chlorophyll a,b and soluble proteins.Rye seeds were treated with 0.01-1 mg/L Atrazine for 16 h,the contents of chlorophyll a and b decreased from 1.26（a）,0.49（b）mg/g FW（control）to 1.15（a）,0.46（b）mg/g FW（0.1 mg/L）and 0.81（a）,0.33（b）mg/g FW（1.0 mg/L）.The content of soluble protein decreased with the increasing concentration of Atrazin.Atrazin had no significant influence on the cell division and chromosome structure variation.The contents of chlorophyll a,b and soluble proteins had no significantly change under the treatment of APM,but the number of chromosome structure variation such as chromosome bridge,multipolar division cells,lagging chromosome and unequal division cells increased significantly.[Conclusion]The critical concentration of Atrazine was 0.1-1.0 mg/L and 4 mg/L of APM in rye.展开更多
The study of dyeability of the modified flax that uses dye-uptake to reflect its modifying effect is reported in this paper. The optimal technological condition is that the concentration of the modifying agent is 4 g/...The study of dyeability of the modified flax that uses dye-uptake to reflect its modifying effect is reported in this paper. The optimal technological condition is that the concentration of the modifying agent is 4 g/l, and NaOH is 6 g/l at liquor ratio of 1∶30 for 60 min. at 85℃.Dyeability include uptake rate and color fastness. Dye-uptake of the modified flax is twice more than that of the unmodified. And their color fastness doesnt fall and some of them raise 0.51 level.展开更多
Let G be a simple graph. Let f be a mapping from V（G） U E（G） to {1, 2,..., k}. Let Cf（v） = {f（v）} U {f（vw）｜w ∈ V（G）,vw ∈ E（G）} for every v ∈ V（G）. If f is a k-propertotal-coloring, and if Cf（u） ...Let G be a simple graph. Let f be a mapping from V（G） U E（G） to {1, 2,..., k}. Let Cf（v） = {f（v）} U {f（vw）｜w ∈ V（G）,vw ∈ E（G）} for every v ∈ V（G）. If f is a k-propertotal-coloring, and if Cf（u） ≠ Cf（v） for uv ∈ V（G）,uv E E（G）, then f is called k-adjacentvertex-distinguishing total coloring of G（k-AVDTC of G for short）. Let χat（G） = min{k｜G has a k-adjacent-vertex-distinguishing total coloring}. Then χat（G） is called the adjacent-vertex-distinguishing total chromatic number. The adjacent-vertex-distinguishing total chromatic number on the Cartesion product of path Pm and complete graph Kn is obtained.展开更多
A k-adjacent strong edge coloring of graph G(V, E) is defined as a proper k-edge coloring f of graph G(V, E) such that f[u] ≠ f[v] for every uv ∈ E(G), where f[u] = {f(uw)|uw ∈ E(G)} and f(uw) denotes the color of ...A k-adjacent strong edge coloring of graph G(V, E) is defined as a proper k-edge coloring f of graph G(V, E) such that f[u] ≠ f[v] for every uv ∈ E(G), where f[u] = {f(uw)|uw ∈ E(G)} and f(uw) denotes the color of uw, and the adjacent strong edge chromatic number is defined as x'as(G) = min{k| there is a k-adjacent strong edge coloring of G}. In this paper, it has been proved that △ ≤ x'as(G) ≤ △ + 1 for outer plane graphs with △(G) ≥ 5, and X'as(G) = △ + 1 if and only if there exist adjacent vertices with maximum degree.展开更多
A graph G is called to be chromatic choosable if its choice number is equal to its chromatic number. In 2002, Ohba conjectured that every graph G with 2Х（G） ＋ 1 or fewer vertices is chromatic choosable. It is easy...A graph G is called to be chromatic choosable if its choice number is equal to its chromatic number. In 2002, Ohba conjectured that every graph G with 2Х（G） ＋ 1 or fewer vertices is chromatic choosable. It is easy to see that Ohba＇s conjecture is true if and only if it is true for complete multipartite graphs. But at present only for some special cases of complete multipartite graphs, Ohba＇s conjecture have been verified. In this paper we show that graphs K6,3,2＊（k-6）,1＊4 （k ≥ 6） is chromatic choosable and hence Ohba＇s conjecture is true for the graphs K6,3,2＊（k-6）,1＊4 and all complete k-partite subgraphs of them.展开更多
Genetic information embedded in DNA sequence and the epigenetic information marked by modifications on DNA and his- tones are essential for the life of eukaryotes. Cells have evolved mechanisms of DNA duplication and ...Genetic information embedded in DNA sequence and the epigenetic information marked by modifications on DNA and his- tones are essential for the life of eukaryotes. Cells have evolved mechanisms of DNA duplication and chromatin restoration to ensure the inheritance of genetic and epigenetic information during cell division and development. In this review, we focus on the maintenance of epigenetic landscape during chromatin dynamics which requires the orchestration of histories and their chaperones. We discuss how epigenetic marks are re-established in the assembly of new chromatin after DNA replication and repair, highlighting the roles of CAF-1 in the process of changing chromatin state. The functions of CAF-1 provide a link be- tween chromatin assembly and epigenetic restoration.展开更多
文摘Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on determination of residual protein in lincomycin hydrochloride. Methods The chromatographic conditions were SuperdexTM peptide column, 0.01 mol*L-1 phosphate buffer solution as mobile phase, and flow rate of 1 mL·min-1. Five hundred microliters of lincomycin hydrochloride solution (3 g of lincomycin hydrochloride dissolved in 10 mL of mobile phase) was injected into the chromatograph and the eluted solution was collected between 6 min and 14.5 min (protein eluted from column within this period), and the residual content of total protein in the eluted solution was assayed using Bradford assay method. Results The average recovery was more than 90% for bovine serum albumin, the calibration equation for the range of 0-12 μg·mL-1 of protein was y=-0.002 4x2+0.064 2x+0.002 9, r2=0.999 9, RSD=0.1%-0.9%, and the LOD and LOQ were 3 and 10 ng·mL-1 of protein, respectively. Conclusion The novel method for determining the residual protein in ferment antibio-tics is simple, rapid, and precise.
基金Supported by Key Project for Science Researches of Ministry of Education(02010)~~
文摘[Objective]The aim was to study the effect of herbicide on the growth of early seedlings of rye（Secale cereale）.[Method]Effect of two kinds of herbicide（Atrazine and APM）on seedling growth of rye was investigated at the physiological,biochemical and cellular level.[Result]The Atrazin significantly decreased the contents of chlorophyll a,b and soluble proteins.Rye seeds were treated with 0.01-1 mg/L Atrazine for 16 h,the contents of chlorophyll a and b decreased from 1.26（a）,0.49（b）mg/g FW（control）to 1.15（a）,0.46（b）mg/g FW（0.1 mg/L）and 0.81（a）,0.33（b）mg/g FW（1.0 mg/L）.The content of soluble protein decreased with the increasing concentration of Atrazin.Atrazin had no significant influence on the cell division and chromosome structure variation.The contents of chlorophyll a,b and soluble proteins had no significantly change under the treatment of APM,but the number of chromosome structure variation such as chromosome bridge,multipolar division cells,lagging chromosome and unequal division cells increased significantly.[Conclusion]The critical concentration of Atrazine was 0.1-1.0 mg/L and 4 mg/L of APM in rye.
文摘The study of dyeability of the modified flax that uses dye-uptake to reflect its modifying effect is reported in this paper. The optimal technological condition is that the concentration of the modifying agent is 4 g/l, and NaOH is 6 g/l at liquor ratio of 1∶30 for 60 min. at 85℃.Dyeability include uptake rate and color fastness. Dye-uptake of the modified flax is twice more than that of the unmodified. And their color fastness doesnt fall and some of them raise 0.51 level.
基金the Science and Research Project of Education Department of Gansu Province (0501-02)
文摘Let G be a simple graph. Let f be a mapping from V（G） U E（G） to {1, 2,..., k}. Let Cf（v） = {f（v）} U {f（vw）｜w ∈ V（G）,vw ∈ E（G）} for every v ∈ V（G）. If f is a k-propertotal-coloring, and if Cf（u） ≠ Cf（v） for uv ∈ V（G）,uv E E（G）, then f is called k-adjacentvertex-distinguishing total coloring of G（k-AVDTC of G for short）. Let χat（G） = min{k｜G has a k-adjacent-vertex-distinguishing total coloring}. Then χat（G） is called the adjacent-vertex-distinguishing total chromatic number. The adjacent-vertex-distinguishing total chromatic number on the Cartesion product of path Pm and complete graph Kn is obtained.
基金National Natural Science Foundation of China (No. 19871036) Qinglan talent Funds of Lanzhou Jiaotong University.
文摘A k-adjacent strong edge coloring of graph G(V, E) is defined as a proper k-edge coloring f of graph G(V, E) such that f[u] ≠ f[v] for every uv ∈ E(G), where f[u] = {f(uw)|uw ∈ E(G)} and f(uw) denotes the color of uw, and the adjacent strong edge chromatic number is defined as x'as(G) = min{k| there is a k-adjacent strong edge coloring of G}. In this paper, it has been proved that △ ≤ x'as(G) ≤ △ + 1 for outer plane graphs with △(G) ≥ 5, and X'as(G) = △ + 1 if and only if there exist adjacent vertices with maximum degree.
基金the Science Foundation of the Education Department of Hebei Province (2005108).
文摘A graph G is called to be chromatic choosable if its choice number is equal to its chromatic number. In 2002, Ohba conjectured that every graph G with 2Х（G） ＋ 1 or fewer vertices is chromatic choosable. It is easy to see that Ohba＇s conjecture is true if and only if it is true for complete multipartite graphs. But at present only for some special cases of complete multipartite graphs, Ohba＇s conjecture have been verified. In this paper we show that graphs K6,3,2＊（k-6）,1＊4 （k ≥ 6） is chromatic choosable and hence Ohba＇s conjecture is true for the graphs K6,3,2＊（k-6）,1＊4 and all complete k-partite subgraphs of them.
基金supported by the National Natural Science Foundation of China (Grant No. 31071087)National Basic Research Program of China (Grant No. 2009CB918702)
文摘Genetic information embedded in DNA sequence and the epigenetic information marked by modifications on DNA and his- tones are essential for the life of eukaryotes. Cells have evolved mechanisms of DNA duplication and chromatin restoration to ensure the inheritance of genetic and epigenetic information during cell division and development. In this review, we focus on the maintenance of epigenetic landscape during chromatin dynamics which requires the orchestration of histories and their chaperones. We discuss how epigenetic marks are re-established in the assembly of new chromatin after DNA replication and repair, highlighting the roles of CAF-1 in the process of changing chromatin state. The functions of CAF-1 provide a link be- tween chromatin assembly and epigenetic restoration.
