Thermal and mechanical properties of poly(latic acid) reinforced with silanized basalt scales

Shan-Shan Yao,Ming-Zhan Gao,Zhao-Yang Feng,Fan-Long Jin,박수진 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.7

Biodegradable poly(lactic acid) (PLA)-based composites were prepared using PLA and basalt scale (BS) viaa solution-blending method. BS surfaces were treated using a silane coupling agent, and their surface properties werecharacterized by high-resolution scanning electron microscopy, energy-dispersive X-ray spectrometry, and X-ray photoelectronspectrometry. Moreover, the influence of BS content on the thermal properties, flexural properties, impactstrength, and morphology of the PLA/silane-coupling-agent-treated BS (KH-BS) composites was analyzed. The thermalstability of the composites significantly increased due to the addition of KH-BS. Impact strength tests showed thatthe impact strength of the PLA/KH-BS composite with 4 wt% KH-BS was 3.14 kJ/m2, which is 51% higher than that ofpristine PLA (2.07 kJ/m2). The analysis of the fracture surfaces of the composites after the impact strength tests revealeda rough morphology with numerous river-like micro-cracks. The study results demonstrate that the addition of KH-BSsignificantly improves the thermal stability and impact strength of PLA/KH-BS composites.

Research on the Expert System of Mathematics Application Question Teaching

Feng Shan,Meng Pan,Wang Yaling 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.12

In view of the automatic solution process of the elementary school mathematics application question, this article has carried on the research to the mathematics application question teaching expert system. Firstly, this paper introduces the definition and structure of the expert system. Then the system structure and function module of the mathematics application question teaching expert system design, gives a detailed description and design of information extraction module, application of rule base, application type library and application question solving process. In this paper, the application of the problem is divided into an integer one step calculation problem, the integer two steps to calculate the application and fractional scores of three parts of the application. At the same time, according to different types of applications, the structural characteristics of the analysis. According to the information extraction model and mathematical operation rules, the overall framework and function modules of the design mathematics teaching expert system are designed. And the realization process is studied. The research results show that the system can be used to demonstrate the solution of mathematical problems in detail. Help students to understand the application of the problem solving process. Make it better learn to know how to solve the problem. And it is helpful for teachers to easily understand method and carry on the teaching process. This also means that the system has practical application value. As a bridge between mathematical theory and practice, mathematical application problems have become more and more important in the implementation of mathematical quality education. It is necessary to cultivate students' mathematics application consciousness and optimize the students' thinking quality. After leaving school, every student can still think about problems and solve the problem mathematically. In consequence, pay more attention to the teaching of application problems, make the cultivation of the consciousness of "use" of mathematics throughout the whole high school stage, and integrate training students' ability of solving mathematics application question into daily teaching, which is conductive to promote the development of students' mathematical innovation, stimulate mathematics learning interest, and improve internal drive of mathematics learning. In our country, many middle school mathematics teachers have carried on the thorough research on the mathematics application problems teaching, which also has made some progress. However, there are still a lot of mistakes in the application teaching in the daily used system. In particular, the college entrance examination still has its influences, teaching material adjustment is not in place, how to teach the application problems plays a crucial role in the overall implementation of the quality education reform.

Isolation and identification of a canine coronavirus strain from giant pandas (Ailuropoda melanoleuca)

Feng-Shan Gao,Xian-zhu Xia,Yu-Wei Gao,Ya-Duo Bai,Xiao-Huan Zou,Gui-Xue Hu 대한수의학회 2009 Journal of Veterinary Science Vol.10 No.3

Two giant pandas (Ailuropoda melanoleuca) died of unknown causes in a Chinese zoo. The clinical disease profile suggested that the pandas may have suffered a viral infection. Therefore, a series of detection including virus isolation, electron microscopy, cytobiological assay, serum neutralization and RT-PCR were used to identify the virus. It was determined that the isolated virus was a canine coronavirus (CCV), on the basis of coronavirus, neutralization by canine anti-CCV serum, and 84.3% to 100% amino acid sequence similarity with CCV. The results suggest that the affected pandas had been infected with CCV.

A SYNCRO-PARALLEL NONSMOOTH PGD ALGORITHM FOR NONSMOOTH OPTIMIZATION

Feng, Shan,Pang, Li-Ping 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.24 No.1

A nonsmooth PGD scheme for minimizing a nonsmooth convex function is presented. In the parallelization step of the algorithm, a method due to Pang, Han and Pangaraj (1991), [7], is employed to solve a subproblem for constructing search directions. The convergence analysis is given as well.

Prevalence and Age, Gender and Geographical Area Distribution of Esophageal Squamous Cell Carcinomas in North China from 1985 to 2006

Feng, Xiao-Shan,Yang, Yan-Tong,Gao, She-Gan,Ru, Yi,Wang, Gong-Ping,Zhou, Bo,Wang, Yu-Feng,Zhang, Peng-Fei,Li, Pu-Yu,Liu, Yong-Xuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

Objective: To establish the prevalence and distribution profile of esophageal squamous cell carcinomas (ESCCs) over a 22-yr period in North China. Methods: Using endoscopy for primary diagnosis and histological analysis for the further confirmation, a total of 74,854 ESCC patients aged 20-89 between January 1985 and December 2006 were investigated to analyze the epidemiological profile including prevalence rates, distribution of age-of-onset, gender and geographical area of ESCC in Luoyang, the highest incidence area of North China. Results: A total of 4092 cases of ESCC were finally diagnosed among 74,854 patients who had their first endoscopies. The prevalence among males was higher than that among females (p<0.01), resulting in an overall male:female OR of 1.2 (95%CI, 1.2-1.3). The prevalence in rural areas was higher than in urban areas (p<0.01), resulting in an overall rural:urban OR of 2.6 (95%CI, 2.4-2.9). The rural:urban ORs and the 95% CI increased continuously from 2.6, 2.3-3.0 to 2.7, 2.2-3.3, respectively, for 4 consecutive periods during the 22-yr study period. Moreover, the median age of onset among females was higher than that among males (p<0.01). For both sexes and in both areas, the prevalence rates declined and the median age of onset rose for 4 consecutive periods in the 22-yrs time frame (p<0.01). Conculsions: These data reveal the epidemiological profile of ESCC in the area of North China, and suggest that urban areas and rural people account for a growing proportion of the ESCC patients although the prevalence of ESCC significantly declined and the median age-of-onset postponed over the 22-yrs period. Moreover, the prevalence status of ESCC in rural areas also underlines the need for public health initiatives aimed at reducing risk factors of this fatal disease.

IQGAP1 is overexpressed in hepatocellular carcinoma and promotes cell proliferation by Akt activation

Feng Chen,Zhi Chen,Hai-Hong Zhu,Lin-Fu Zhou,Shan-Shan Wu,Jing Wang 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.7

The scaffold protein IQGAP1 shows elevated levels in several cancer types, but its expression in hepatocellular carcinoma is unknown. We found that 58%of human hepatocellular carcinoma tissue samples had increased IQGAP1 expression compared to adjacent normal tissue. Overexpressing IQGAP1 raised the in vivo tumorigenicity of hepatocellular carcinoma cells, and forced overexpression of IQGAP1 in vitro stimulated cell proliferation. Cell growth was reduced by knockdown or mutation of IQGAP1, or by treatment of cells with a phosphotidylinositol 3-kinase inhibitor. To determine the mechanism by which IQGAP1 overexpression affected hepatocellular carcinoma cells,we confirmed its interaction in these cells with mammalian target of rapamycin (mTOR), a serine/threonine kinase that integrates signals about nutrient and energy status with downstream effectors that influence cell division. In addition, we discovered a new interaction involving IQGAP1, mTOR and Akt, which is a downstream target of mTOR. Akt phosphorylation on Ser-473, which is catalyzed by mTOR and required for Akt activation, increased with increasing amounts of IQGAP1, and decreased with IQGAP1 mutation. We hypothesize that IQGAP1 is a scaffold that facilitates mTOR and Akt interaction.

IQGAP1 is overexpressed in hepatocellular carcinoma and promotes cell proliferation by Akt activation

Chen, Feng,Zhu, Hai-Hong,Zhou, Lin-Fu,Wu, Shan-Shan,Wang, Jing,Chen, Zhi Korean Society for Biochemistry and Molecular Bion 2010 Experimental and molecular medicine Vol.42 No.7

The scaffold protein IQGAP1 shows elevated levels in several cancer types, but its expression in hepatocellular carcinoma is unknown. We found that 58% of human hepatocellular carcinoma tissue samples had increased IQGAP1 expression compared to adjacent normal tissue. Overexpressing IQGAP1 raised the in vivo tumorigenicity of hepatocellular carcinoma cells, and forced overexpression of IQGAP1 in vitro stimulated cell proliferation. Cell growth was reduced by knockdown or mutation of IQGAP1, or by treatment of cells with a phosphotidylinositol 3-kinase inhibitor. To determine the mechanism by which IQGAP1 overexpression affected hepatocellular carcinoma cells, we confirmed its interaction in these cells with mammalian target of rapamycin (mTOR), a serine/threonine kinase that integrates signals about nutrient and energy status with downstream effectors that influence cell division. In addition, we discovered a new interaction involving IQGAP1, mTOR and Akt, which is a downstream target of mTOR. Akt phosphorylation on Ser-473, which is catalyzed by mTOR and required for Akt activation, increased with increasing amounts of IQGAP1, and decreased with IQGAP1 mutation. We hypothesize that IQGAP1 is a scaffold that facilitates mTOR and Akt interaction.

On positive influence dominating sets in social networks

Wang, Feng,Du, Hongwei,Camacho, Erika,Xu, Kuai,Lee, Wonjun,Shi, Yan,Shan, Shan Elsevier 2011 Theoretical computer science Vol.412 No.3

<P><B>Abstract</B></P><P>In this paper, we investigate the positive influence dominating set (PIDS) which has applications in social networks. We prove that PIDS is APX-hard and propose a greedy algorithm with an approximation ratio of H(δ) where H is the harmonic function and δ is the maximum vertex degree of the graph representing a social network.</P>

Gram-Scale Production of Ginsenoside F1 Using a Recombinant Bacterial β-Glucosidase

( Dong-shan An ),( Chang-hao Cui ),( Muhammad Zubair Siddiqi ),( Hong Shan Yu ),( Feng-xie Jin ),( Song-gun Kim ),( Wan-taek Im ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.9

Naturally occurring ginsenoside F1 (20-O-β-D-glucopyranosyl-20(S)-protopanaxatriol) is rare. Here, we produced gram-scale quantities of ginsenoside F1 from a crude protopanaxatriol saponin mixture comprised mainly of Re and Rg1 through enzyme-mediated biotransformation using recombinant β-glucosidase (BgpA) cloned from a soil bacterium, Terrabacter ginsenosidimutans Gsoil 3082^T. In a systematic step-by-step process, the concentrations of substrate, enzyme, and NaCl were determined for maximal production of F1. At an optimized NaCl concentration of 200 mM, the protopanaxatriol saponin mixture (25 mg/ml) was incubated with recombinant BgpA (20 mg/ml) for 3 days in a 2.4 L reaction. Following octadecylsilyl silica gel column chromatography, 9.6 g of F1 was obtained from 60 g of substrate mixture at 95% purity, as assessed by chromatography. These results represent the first report of gram-scale F1 production via recombinant enzyme-mediated biotransformation.

베이징 대잡원(大雜院)의 공간 구성에 드러난 이웃 관계 - 영화 석조가(夕照街)를 중심으로

풍산(Feng, Shan),백진(Baek, Jin) 대한건축학회 2023 대한건축학회 학술발표대회 논문집 Vol.43 No.1