A graph G is called chromatic-choosable if its choice number is equal to its chromatic number, namely ch（G） = X（G）. Ohba＇s conjecture states that every graph G with 2X（G）＋ 1 or fewer vertices is chromatic- cho...A graph G is called chromatic-choosable if its choice number is equal to its chromatic number, namely ch（G） = X（G）. Ohba＇s conjecture states that every graph G with 2X（G）＋ 1 or fewer vertices is chromatic- choosable. It is clear that Ohba＇s conjecture is true if and only if it is true for complete multipartite graphs. Recently, Kostochka, Stiebitz and Woodall showed that Ohba＇s conjecture holds for complete multipartite graphs with partite size at most five. But the complete multipartite graphs with no restriction on their partite size, for which Ohba＇s conjecture has been verified are nothing more than the graphs Kt＋3,2.（k-t-l）,l.t by Enotomo et al., and gt＋2,3,2.（k-t-2）,l.t for t ≤ 4 by Shen et al.. In this paper, using the concept of f-choosable （or Lo-size-choosable） of graphs, we show that Ohba＇s conjecture is also true for the graphs gt＋2,3,2.（k-t-2）,l.t when t ≥ 5. Thus, Ohba＇s conjecture is true for graphs Kt＋2,3,2,（k-t-2）,l＊t for all integers t 〉 1.展开更多
[目的]探讨红景天[Rhodiola crenulata(Hook.f.et.Thoms.)H.Ohba]提取物对小鼠免疫功能的影响。[方法]将192只BALB/c小鼠随机分为4批,每批分为4组,分别为低、中、高3个剂量组和1个溶剂对照组,连续灌药(20 m l/kg.体重)30 d,测定各免疫...[目的]探讨红景天[Rhodiola crenulata(Hook.f.et.Thoms.)H.Ohba]提取物对小鼠免疫功能的影响。[方法]将192只BALB/c小鼠随机分为4批,每批分为4组,分别为低、中、高3个剂量组和1个溶剂对照组,连续灌药(20 m l/kg.体重)30 d,测定各免疫指标。[结果]高剂量组红景天提取物可提高小鼠碳廓清能力(P<0.05);中剂量和高剂量组能增强绵羊红细胞诱导小鼠DTH能力(P<0.05),促进NK细胞活性(P<0.05)和血清凝血素的生成(P<0.05),增加抗体生成细胞数的生成(P<0.05),并且能提高小鼠腹腔巨噬细胞吞噬鸡红细胞的能力(P<0.05),但对免疫器官/体重质量值和ConA诱导的小鼠脾淋巴细胞转化能力无显著影响。[结论]红景天提取物具有增强正常小鼠免疫力的功能,该研究为开发有食用价值的保健食品提供了试验依据。展开更多
Objective:Rhodiolae Crenulatae Radix et Rhizoma(Hongjingtian in Chinese,RCRR),the roots and rhizomes of Rhodiola crenulata and its application in the medicinal market is very chaotic.In this study,DNA barcoding databa...Objective:Rhodiolae Crenulatae Radix et Rhizoma(Hongjingtian in Chinese,RCRR),the roots and rhizomes of Rhodiola crenulata and its application in the medicinal market is very chaotic.In this study,DNA barcoding database and identification engine of Rhodiola species were established,decoction pieces from the medicinal market were identified,and the application and challenges of DNA barcoding in the rapid radiation of Rhodiola species were analyzed.This study provides reference for the protection,rational development,and utilization of endangered resources within Rhodiola species.Methods:A total of 50 original plant samples from 20 species of the genus Rhodiola from Hebei,Xinjiang,Xizang,Jilin,and other major production areas were collected.Theses samples cover the typical distribution area(Qinghai-Tibetan Platea)of Rhodiola species and other scattered alpine regions(Changbai Mountain,Taibai Mountain,Lushan Mountain,etc.),it encompasses all Rhodiola species with thick rhizomes in China.ITS2 and psb A-trnH barcode of Rhodiola database(BORD)were established and an identification engine named Rhodiola-IDE was developed.The stability and accuracy of the standard DNA barcoding database were evaluated using two datasets.Rhodiola-IDE identified 31 decoction pieces of RCRR from the medicinal material market.Results:The BORD containing 1532 sequences of 88 Rhodiola species has been established,and the identification efficiency results showed good accuracy and stability.According to the Chinese Pharmacopoeia(2020 edition),23 samples(74.2%)were identified as authentic R.crenulata,while the rest of the marketed varieties were R.kirilowii,R.dumulosa,and R.fastigiata.The product label"Larger flower,Hongjingtian"was identified as R.crenulata.Samples labeled as"Smaller flower,Hongjingtian"were identified as R.crenulata,R.kirilowii,and R.fastigiata.Conclusion:ITS2 and psb A-trn H barcodes can identify monophyletic groups represented by R.crenulata.However,for non-monophyletic species,it is necessary to collect as many samples as possible and combine them with multiple markers for joint identification.This study discussed the application and challenges of DNA barcodes in Rhodiola under rapid radiation conditions,providing a scientific basis for the rational development and utilization of Rhodiola varieties.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
基金Supported by the National Natural Science Foundation of China(No.10871058)the project for mathematical research from the Natural Science Foundation of Hebei Province,China(No.08M004)Hebei Normal University of Science and Technology,China(ZDJS2009 and CXTD2012)
文摘A graph G is called chromatic-choosable if its choice number is equal to its chromatic number, namely ch（G） = X（G）. Ohba＇s conjecture states that every graph G with 2X（G）＋ 1 or fewer vertices is chromatic- choosable. It is clear that Ohba＇s conjecture is true if and only if it is true for complete multipartite graphs. Recently, Kostochka, Stiebitz and Woodall showed that Ohba＇s conjecture holds for complete multipartite graphs with partite size at most five. But the complete multipartite graphs with no restriction on their partite size, for which Ohba＇s conjecture has been verified are nothing more than the graphs Kt＋3,2.（k-t-l）,l.t by Enotomo et al., and gt＋2,3,2.（k-t-2）,l.t for t ≤ 4 by Shen et al.. In this paper, using the concept of f-choosable （or Lo-size-choosable） of graphs, we show that Ohba＇s conjecture is also true for the graphs gt＋2,3,2.（k-t-2）,l.t when t ≥ 5. Thus, Ohba＇s conjecture is true for graphs Kt＋2,3,2,（k-t-2）,l＊t for all integers t 〉 1.
文摘[目的]探讨红景天[Rhodiola crenulata(Hook.f.et.Thoms.)H.Ohba]提取物对小鼠免疫功能的影响。[方法]将192只BALB/c小鼠随机分为4批,每批分为4组,分别为低、中、高3个剂量组和1个溶剂对照组,连续灌药(20 m l/kg.体重)30 d,测定各免疫指标。[结果]高剂量组红景天提取物可提高小鼠碳廓清能力(P<0.05);中剂量和高剂量组能增强绵羊红细胞诱导小鼠DTH能力(P<0.05),促进NK细胞活性(P<0.05)和血清凝血素的生成(P<0.05),增加抗体生成细胞数的生成(P<0.05),并且能提高小鼠腹腔巨噬细胞吞噬鸡红细胞的能力(P<0.05),但对免疫器官/体重质量值和ConA诱导的小鼠脾淋巴细胞转化能力无显著影响。[结论]红景天提取物具有增强正常小鼠免疫力的功能,该研究为开发有食用价值的保健食品提供了试验依据。
基金supported by China Postdoctoral Science Foundation(No.2022M720504)the National Key Research and Development Program of China:Intergovernmental Cooperation in International Science and Technology Innovation(No.2022YFE0119300)+3 种基金CAMS Innovation Fund for Medical Sciences(CIFMS)(No.2021-I2M-1-029 and No.2021-I2M-1-032)Open project supported by Hebei(Chengde)Industrial Technology Institute of Chinese Medicinal Materials(No.CYKF202301)the graduate student innovation ability training of Education of Hebei Province Department(No.CXZZSS2024118)Key project at central government level:The ability establishment of sustainable use for valuable Chinese medicine resources(No.2060302)。
文摘Objective:Rhodiolae Crenulatae Radix et Rhizoma(Hongjingtian in Chinese,RCRR),the roots and rhizomes of Rhodiola crenulata and its application in the medicinal market is very chaotic.In this study,DNA barcoding database and identification engine of Rhodiola species were established,decoction pieces from the medicinal market were identified,and the application and challenges of DNA barcoding in the rapid radiation of Rhodiola species were analyzed.This study provides reference for the protection,rational development,and utilization of endangered resources within Rhodiola species.Methods:A total of 50 original plant samples from 20 species of the genus Rhodiola from Hebei,Xinjiang,Xizang,Jilin,and other major production areas were collected.Theses samples cover the typical distribution area(Qinghai-Tibetan Platea)of Rhodiola species and other scattered alpine regions(Changbai Mountain,Taibai Mountain,Lushan Mountain,etc.),it encompasses all Rhodiola species with thick rhizomes in China.ITS2 and psb A-trnH barcode of Rhodiola database(BORD)were established and an identification engine named Rhodiola-IDE was developed.The stability and accuracy of the standard DNA barcoding database were evaluated using two datasets.Rhodiola-IDE identified 31 decoction pieces of RCRR from the medicinal material market.Results:The BORD containing 1532 sequences of 88 Rhodiola species has been established,and the identification efficiency results showed good accuracy and stability.According to the Chinese Pharmacopoeia(2020 edition),23 samples(74.2%)were identified as authentic R.crenulata,while the rest of the marketed varieties were R.kirilowii,R.dumulosa,and R.fastigiata.The product label"Larger flower,Hongjingtian"was identified as R.crenulata.Samples labeled as"Smaller flower,Hongjingtian"were identified as R.crenulata,R.kirilowii,and R.fastigiata.Conclusion:ITS2 and psb A-trn H barcodes can identify monophyletic groups represented by R.crenulata.However,for non-monophyletic species,it is necessary to collect as many samples as possible and combine them with multiple markers for joint identification.This study discussed the application and challenges of DNA barcodes in Rhodiola under rapid radiation conditions,providing a scientific basis for the rational development and utilization of Rhodiola varieties.
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.
