Regular embeddings of complete multipartite graphs

Du, Shao-Fei,Kwak, Jin Ho,Nedela, Roman Elsevier 2005 European journal of combinatorics : Journal europ& Vol.26 No.3

<P><B>Abstract</B></P><P>In this paper, we classify all regular embeddings of the complete multipartite graphs <I>K</I><SUB><I>p</I>,…,<I>p</I></SUB> for a prime <I>p</I> into orientable surfaces. Also, the same work is done for the regular embeddings of the lexicographical product of any connected arc-transitive graph of prime order <I>q</I> with the complement of the complete graph of prime order <I>p</I>, where <I>q</I> and <I>p</I> are not necessarily distinct. Lots of regular maps found in this paper are Cayley maps.</P>

Establishment of and Comparison between Orthotopic Xenograft and Subcutaneous Xenograft Models of Gallbladder Carcinoma

Du, Qiang,Jiang, Lei,Wang, Xiao-Qian,Pan, Wei,She, Fei-Fei,Chen, Yan-Ling Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Background: Gallbladder carcinoma (GBC) is the most common carcinoma of the biliary system. Among its research models, orthotopic xenograft models, important research tools, have been rarely reported in the literature however. Aim: To explore establishment of an orthotopic xenograft model and to evaluate the advantage and disadvantage as compared with other models. Materials and Methods: Subcutaneous xenograft and orthotopic xenograft models of gallbladder carcinoma in nude mice were established and compared with human gallbladder carcinomas. Results: For the orthotopic xenograft model and clinical gallbladder carcinomas, the lymph node metastatic rates were 69.2% and 53.3% (p>0.05); ascites generation rates, 38.5% and 11.7%(p<0.05); liver invasive rates, 100% and 61.7%(p<0.05); and lymphatic vessel densities (LVD), $10.4{\pm}3.02$ and $8.77{\pm}2.92$ (p>0.05), respectively. In the subcutaneous xenograft model, no evidence of ascites generation, lymph node metastasis and liver metastasis were found, and its LVD was lower ($4.56{\pm}1.53$, p<0.05). Conclusions: Compared with the subcutaneous xenograft model, the orthotopic xenograft model better simulates clinical gallbladder carcinoma in terms of metastasis and invasion, which may be attributed to the difference in microenvironment and LVD.

Classification of regular embeddings of hypercubes of odd dimension

Du, Shao-Fei,Kwak, Jin Ho,Nedela, Roman Elsevier 2007 Discrete mathematics Vol.307 No.1

<P><B>Abstract</B></P><P>By a regular embedding of a graph into a closed surface we mean a 2-cell embedding with the automorphism group acting regularly on flags. Recently, Kwon and Nedela [Non-existence of nonorientable regular embeddings of n-dimensional cubes, Discrete Math., to appear] showed that no regular embeddings of the <I>n</I>-dimensional cubes <SUB>Qn</SUB> into nonorientable surfaces exist for any positive integer n>2. In 1997, Nedela and Škoviera [Regular maps from voltage assignments and exponent groups, European J. Combin. 18 (1997) 807–823] presented a construction giving for each solution of the congruence <SUP>e2</SUP>≡1(modn) a regular embedding <SUB>Me</SUB> of the hypercube <SUB>Qn</SUB> into an orientable surface. It was conjectured that all regular embeddings of <SUB>Qn</SUB> into orientable surfaces can be constructed in this way. This paper gives a classification of regular embeddings of hypercubes <SUB>Qn</SUB> into orientable surfaces for <I>n</I> odd, proving affirmatively the conjecture of Nedela and Škoviera for every odd <I>n</I>.</P>

Ethanol extract of Piper longum L. attenuates gentamicin-induced hair cell loss in neonatal cochlea cultures.

Du, Xiao Fei,Song, Jae-Jun,Hong, Seungug,Kim, Jihye Govi-Verlag Pharmazeutischer Verlag [etc.] ; Verla 2012 Die Pharmazie Vol.67 No.6

<P>Piper longum L. (PL), also as known as long pepper, a well-known spice and traditional medicine in Asia and Pacific islands, has been reported to exhibit wide spectrum activity including antioxidant activity. However, little information is available on its protective effect on gentamicin (GM) induced ototoxicity which is commonly regarded as being mediated by reactive oxygen species and reactive nitrogen species. This study was undertaken to investigate the protective effect of PL ethanol extract on gentamicin-induced hair cell loss in neonatal cochlea cultures. Cochlea cultures from postnatal day 2-3 mice were used for analysis of the protective effects of PL against gentamicin-induced hair cell loss by phalloidin staining. E. coil cultures were used to determine whether PL interferes with the antibiotic activity of GM. Nitric oxide (NO)-scavenging activity of PL was also measured in vitro. GM induced significant dose-dependent hair cell loss in cochlea cultures. However, without interfering with the antibiotic activity of GM, PL showed a significant and concentration-dependent protective effect against GM-induced hair cell loss, and hair cells retained their stereocilia well. In addition, PL expressed direct scavenging activity toward NO radical liberated within solution of sodium nitroprusside. These findings demonstrate the protective effect of PL on GM-induced hair cell loss in neonatal cochlea cultures, and suggest that it might be of therapeutic benefit for treatment of GM-induced ototoxicity.</P>

Synergistic Immunostimulating Activity of Pidotimod and Red Ginseng Acidic Polysaccharide against Cyclophosphamide-induced Immunosuppression

Du, Xiao Fei,Jiang, Cheng Zhe,Wu, Chun Fu,Won, Eun-Kyung,Choung, Se-Young 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9

We investigated the synergistic effect of combined treatment with red ginseng acidic polysaccharide (RGAP) from Panax ginseng C.A. Meyer and pidotimod in cyclophosphamide-treated mice. The combination of pidotimod and RGAP restored concanavalin A-induced splenic T cell proliferation and LPS-stimulated B cell proliferation significantly. The production of nitric oxide from peritoneal macrophages was increased by the combinations. NK cell activity was increased by RGAP alone or in combination with pidotimod. A synergistic increase in the level of serum IL-12 and interferongamm was observed when the combination of the two was used. RGAP alone or in combination with pidotimod modulated the level of serum C-reactive protein to a near-normal level. These results indicate that combinations of pidotimod and RGAP are synergistic and suggest that combination therapy using pidotimod and RGAP for improving immune activity may provide an additional benefit over the use of the two drugs by themselves.

Packaging Framework System Under International Trade Rules

Xue-Fei Du,조현숙 강원대학교 경영경제연구소 2022 Asia-Pacific Journal of Business Vol.13 No.3

Purpose - The purpose of this study was to expound the packaging framework system(PFS) under international trade rules. Design/methodology/approach - This study analyzed packaging framework system and packaging regulations and technical standards in international regulations and major countries and classified these in some standards Findings - First, the study provides packaging provisions associated with packaging regulations and technical standards (PRTS). Then, the basis of PFS in international trade rules was proposed; it is believed that the PFS was composed of packaging legal system in WTO institutional framework (WTO-PLS), international organization packaging standard system (IO-PSS) and major countries or regions packaging regulatory system (MCR-PRS). Secondly, this paper expounded relations and legal characteristics of the three packaging systems. Finally, This study investigated PRTS coverage under technical barriers to trade (TBT) and Sanitary and Phytosanitary measures (SPS). Research implications or Originality The regulations associated with PRTS have played a key role in challenges to merchandise trade in international trade. This study has significance in classifying packaging related reticulations into several criteria unlike previous studies. Therefore it is hope that this study can provide a supplementary document for the existing research of PRTS.

Synergistic Immunostimulating Activity of Pidotimod and Red Ginseng Acidic Polysaccharide against Cyclophosphamide-induced Immunosuppression

Xiao Fei Du,Cheng Zhe Jiang,Chun Fu Wu,원은경,정세영 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9

We investigated the synergistic effect of combined treatment with red ginseng acidic polysaccharide (RGAP) from Panax ginseng C.A. Meyer and pidotimod in cyclophosphamide-treated mice. The combination of pidotimod and RGAP restored concanavalin A-induced splenic T cell proliferation and LPS-stimulated B cell proliferation significantly. The production of nitric oxide from peritoneal macrophages was increased by the combinations. NK cell activity was increased by RGAP alone or in combination with pidotimod. A synergistic increase in the level of serum IL-12 and interferongamm was observed when the combination of the two was used. RGAP alone or in combination with pidotimod modulated the level of serum C-reactive protein to a near-normal level. These results indicate that combinations of pidotimod and RGAP are synergistic and suggest that combination therapy using pidotimod and RGAP for improving immune activity may provide an additional benefit over the use of the two drugs by themselves.

Case Study of the Impact of Packing Regulations and Technical Standards on Expert Trade

Xue-Fei Du,Hyun-Sook Cho 강원대학교 경영경제연구소 2021 Asia-Pacific Journal of Business Vol.12 No.3

technical standard barrier on export trade. Design/methodology/approach - This study analyzed cases related to packing in major countries such as US, EU and so on. It is also show the example of export volume changed based on PRTS. Findings - First, the role of packaging and the reason why countries issued relevant packaging provisions were introduced. Then, the impacts of PRTS on export trade were expounded. And next, we focused on investigating some PRTS related cases in export trade and gave an example of export volume changed based on PRTS. Finally, we produced implications for business leaders to aware of the importance of PRTS in export. Research implications or Originality This study provide PRTS information to traders. Trade pratitioners can respond to PRTS related regulations, actively develop PRTS technology, and take relavant to deal with PRTS barriers to eliminate or weaken the adverse effects of PRTS on export trade.

A Study on Green Packaging Barriers Related to China’s Export

Xue-fei Du,Hyun-Sook Cho 한국무역통상학회 2021 무역통상학회지 Vol.21 No.1

Green packaging (GP), also known as sustainable packaging, which is considered to protect environment and save resources, was meeting the requirements of sustainable development. In trade area, through the important role in the ecological environment and human health, GP and its system might effect on China’s export a new trade protection measure. Here, this paper explained the definition and reimbursement of GP/GPB. It also provided packaging regulations in China’s major trading partners such as the European Union, the United States and South Korea and showed some trade cases related to packaging. Finally, in order to deal with GPBs effectively and eliminate or be weaken the impact of GPBs on China’s export trade, this paper proposed some suggestions. It is hoped that through the study of this paper, the research and development (R&D) of GP can be promoted, and the application value of GP can be exerted in China’s foreign trade and social production.

Synthesis and Properties of Arylacetylene Resins with Siloxane Units

Fei Gao,Lingling Zhang,Lemin Tang,Jian Zhang,Yan Zhou,Farong Huang,Lei Du 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.4

A series of arylacetylene resins with siloxane units were synthesized by the condensation reactions of m-diethynylbenzene magnesium reagents with various α,ω-bis(chloro)dimethylsiloxanes. These resins are liquids and are miscible with common organic solvents at room temperature. The structures of the resins were characterized by FT-IR, 1H NMR,13C NMR, 29Si NMR, and gel permeation chromatography (GPC). The thermal behaviors of the resins were examined with differential scanning calorimetry (DSC). These resins have good processability. They can be thermally crosslinked through the ethynyl groups to produce cured resins. The thermal and thermooxidative stabilities of the cured resins were studied by thermogravimetric analysis (TGA). The cured resins possess high thermal and thermooxidative stability. Their decomposition occurs at above 500 oC in both N2 and air. With increasing the length of siloxane units in the resins, the thermal stability of the cured resins decreases in N2. When the cured resins were sintered above 1450 oC under argon, hard and glassy SiOC ceramics were obtained. These SiOC ceramics have the decomposition temperatures at 5% weight loss above 800 oC in air.