Transcrystalline growth of PLLA on carbon fiber grafted with nano-SiO2 towards boosting interfacial bonding in bone scaffold

Pei Feng,Jiye Jia,Shuping Peng,Yang Shuai,Hao Pan,Xinna Bai,CIJUN SHUAI 한국생체재료학회 2022 생체재료학회지 Vol.26 No.1

Background: The reinforcement effect of fiber-reinforced polymer composites is usually limited because of the poor interfacial interaction between fiber and polymer, though fiber reinforcement is regarded as an effective method to enhance the mechanical properties of polymer. Methods: In this study, nano-SiO2 particles grafted by 3-Glycidoxypropyltrimethoxysilane (KH560) were introduced onto the surface of 3-Aminopropyltriethoxysilane (KH550) modified carbon fiber (CF) by a self-assembly strategy to improve the interfacial bonding between CF and biopolymer poly (lactic acid) (PLLA). Results: The results indicated that PLLA chains preferred to anchor at the surface of nano-SiO2 particles and then formed high order crystalline structures. Subsequently, PLLA spherulites could epitaxially grow on the surface of functionalized CF, forming a transcrystalline structure at the CF/PLLA interface. Meanwhile, the nano-SiO2 particles were fixed in the transcrystalline structure, which induced a stronger mechanical locking effect between CF and PLLA matrix. The results of tensile experiments indicated that the PLLA/CF-SiO2 scaffold with a ratio of CF to SiO2 of 9:3 possessed the optimal strength and modulus of 10.11 MPa and 1.18 GPa, respectively. In addition, in vitro tests including cell adhesion and fluorescence indicated that the scaffold had no toxicity and could provide a suitable microenvironment for the growth and proliferation of cell. Conclusion: In short, the PLLA/CF-SiO2 scaffold with good mechanical properties and cytocompatibility had great potential in the application of bone tissue engineering.

Dominant genera of cyanobacteria in Lake Taihu and their relationships with environmental factors

Lijun Feng,Shiyou Liu,Wenxian Wu,Jiawen Ma,Pei Li,Hailing Xu,Na Li,Yaoyu Feng 한국미생물학회 2016 The journal of microbiology Vol.54 No.7

Cyanobacterial blooms in freshwaters have become one of the most widespread of environmental problems and threaten water resources worldwide. Previous studies on cyanobacteria in Lake Taihu often collected samples from one site (like Meiliang Bay or Zhushan Bay) and focused on the variation in patterns or abundance of Microcystis during the blooming season. However, the distribution of cyanobacteria in Lake Taihu shows differing pattern in various seasons. In this study, water samples were collected monthly for one year at five sites in Lake Taihu with different trophic status and a physicochemical analysis and denaturing gradient gel electrophoresis (DGGE) were conducted. DGGE fingerprint analysis showed that Microcystis (7/35 bands) and Synechococcus (12/35 bands) were the two most dominant genera present during the study period at all five sites. Cyanobium (3/35 bands) was the third most common genus which has seldom been previously reported in Lake Taihu. Redundancy analysis (RDA) indicated that the cyanobacterial community structure was significantly correlated with NO3 --N, CODMn, and NH4 +-N in the winter and spring, whereas it was correlated with water temperature in the summer and autumn. Limiting the nutrient input (especially of N and C loading) in Lake Taihu would be a key factor in controlling the growth of different genera of cyanobacteria.

Enhancing the Anaerobic Digestion of Corn Stalks Using Composite Microbial Pretreatment

( Xu Feng Yuan ),( Pei Pei Li ),( Hui Wang ),( Xiao Fen Wang ),( Xu Cheng ),( Zong Jun Cui ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.7

A composite microbial system (XDC-2) was used to pretreat and hydrolyze corn stalk to enhance anaerobic digestion. The results of pretreatment indicated that sCOD concentrations of hydrolysate were highest (8,233 mg/l) at the fifth day. XDC-2 efficiently degraded the corn stalk by nearly 45%, decreasing the cellulose content by 22.7% and the hemicellulose content by 74.1%. Total levels of volatile products peaked on the fifth day. The six major compounds present were ethanol (0.29 g/l), acetic acid (0.55 g/l), 1,2-ethanediol (0.49 g/l), propionic acid (0.15 g/l), butyric acid (0.22 g/l), and glycerine (2.48 g/l). The results of anaerobic digestion showed that corn stalks treated by XDC-2 produced 68.3% more total biogas and 87.9% more total methane than untreated controls. The technical digestion time for the treated corn stalks was 35.7% shorter than without treatment. The composite microbial system pretreatment could be a cost-effective and environmentally friendly microbial method for efficient biological conversion of corn stalk into bioenergy.

解讀唐代文官最佳升遷途徑的一把新鑰匙

馮培紅(Feng Pei-hong) 경북대학교 아시아연구소 2010 아시아연구 Vol.- No.8

賴瑞和씨의 저서 당대중층문관(唐代中層文官)은 그의 당대 문관에 대한 전체 3부작의 연구 가운데 제2부에 해당하는 것이다. 삼원어사(三院御史)․습유(拾遺)․보궐(補闕)․낭관(郎官) 등의 경관(京官)과, 현령(縣令).사록(司錄)이나 참군(參軍) 등의 지방관, 그리고 막부관(幕府官)으로서의 판관(判官) 등을 포함하여 그가 정의하고 있는 당대 중층 문관들의 10가지 관직들에 대하여 주로 토론하고 있다. 본문에서는 시각이나 방법, 그리고 참신한 점이나 생각해야 할 문제 점 등의 방면에서 이 책을 평론하고 있다. 일반적인 당대 관제(官制)를 다룬 저술과 다른 점은 이 책이 특출나게 봉연(封演)의 ‘팔준도(八儁圖)’와 백거이(白居易)의 책문(策文)에서 계시(啓示)를 얻었다는 점이다. 팔준(八儁)의 기초 위에 이를 관직으로 약간 확충하여서, 당대 문관의 가장 바람직한 승진 과정을 잡아서 당대 사인(士人)의 임관 규율을 그려내었고, 그들의 임관 모델을 만들어내었다. 이것이 당대 관제 연구의 새로운 방식을 만들어 낸 것이다. 연구방법상에서 작자는 안례(案例)의 방법을 사용하여 전기(傳記) 가운데에서 제도사(制度史)를 찾아내는데 힘썼으며, 대량의 생동적인 관력(官歷)을 예증을 운영하여 제도사 연구의 정태적이고 무미건조한 서술에서 벗어나서 당대 중층 문관들의 승진 과정을 명확하게 밝혔다. 그는 또한 전해져 내려온 역사물과 전기물, 시문과 소설, 묘지명과 비석문, 출토된 문서와 여러 종류의 문헌들을 힘껏 운용하는 다양한 증거방법을 사용하였다. 그리하여, 이를 서로 비교하여 상세히 밝혀내어서, 이로서 이전에 밝히지 못하던 것을 밝혀낼 수 있게 되었다. 예컨대 계관(階官)화, 공관(勳官)화, 주현의 등급, 관원의 환유(宦游) 등의 방면에서 그는 새로운 의미의 관점을 풍부하게 제시하여서, 당대 관제의 연구를 심화하고 넓히는 데에 기여하였다. 아울러 일련의 새로운 연구 과제로서, 산(散)․공(勳)․위(衛) 관제, 기술관(伎術官), 청관(清官), 당시(唐詩)와 관제(官制)등을 제시하여서, 연구를 진일보시키기 위해서 새로운 연구방향을 제시하였다. 또한 본서는 새로운 시각에만 그친 것이 아니라 새로이 밝혀낸 바도 크다. 또한, 문필이 아름답고 활발하고 생동감 있으며, 지금으로서는 당대 관제 연구의 가장 새로운 의미를 갖고 있으며, 가장 읽을 만한 저작이라고 할 수 있다. 당연히, 본서는 관직의 표준적인 채용과 세 계층의 문관의 분류원칙 부분에 있어서는 여전히 토론해야할 여지를 남겨놓고 있다. 또한 여러 관점에서는 아직 더 논의되어야 할 여지를 남겨두고 있다. 또한, 너무나도 많은 오탈(誤脫)자가 존재한다. 관제는 중국역사를 연구하는 데에서 4가지 열쇄 가운데 하나이다. 賴瑞和씨는 새로운 열쇄하나를 찾아낸 셈이다. 그가 당대 관제 연구의 새로운 영역을 새로이 열어놓은 것을 통해서, 이왕의 연구 규범을 돌파하고, 이정표를 마련한 것과 같은 의미를 갖추고 있다고 할 수 있다. As the second book of Lai Swee-fo’s trilogy about civil officials in the Tang dynasty, Civil Officials in the Middle-Level in the Tang Dynasty, studies ten kinds of officials, which contains some officials working in the capital such as Jianchayushi, Dianzhong-shiyushi, Shiyushi, Shiyi, Buque, Langzhong and Yuanwailang, as well as some local officials, such as Xianling and Silu(or Lushi)-canjun, and Panguan. I write a review to this new book about the visual angle, research methods, innovations and some problems. Quite different from other similar subject works, this book discovered and griped a law of the civil official career in the Tang dynasty, which was enlightened by Feng Yan’s “bajun-tu” and Bai Ju-yi’s works. Prof. Lai added a few officials on the base of “bajun” to construct a perfect route of promotion of civil officials. I think this is a new and important discovery in research field of official system in the Tang dynasty. In order to describe a vivid promotion process of the middle-level civil officials more clearly, Prof. Lai concentrated on biography to study history of official system. He used the method of case study and analyzed a large mount of vivid instances of official career, which avoided static and uninteresting narratives. He also used the method of multi-evidence with history records, poems, novels, epitaphs, inscriptions and unearthed documents and made unprecedented achievements. After that, Prof. Lai put forward several new ideas such as official system for jieguan and xunguan, rank of zhou and xian, being an official everywhere, which deepened and expanded the studies of official system in the Tang dynasty. At the same time, he also came up with many new research issues such as sanguan, xunguan, weiguan, jishuguan, qingguan, poem and official system, and pointed out research direction in the future. I think this is the most innovative, deepest and most interesting book about official system in the Tang dynasty because of new visual angle, important innovations and vivid writing. However, there are still some problems in this book. For instance, the standard of selecting officials, the principle of classifying civil officials with three levels, some mistakes of viewpoints and words. Official system is considered as one of four keys to study Chinese ancient history. I held the idea that Prof. Lai discovered a new key in the research field to study official system in the Tang dynasty. It broke through the convention and became an important milestone in this research field.

소셜 네트워크 기반의 콘텐츠 추천 시스템의 개발

배운봉 ( Yun-feng Pei ),왕청 ( Qing Wang ),권경락 ( Kyung-lag Kwon ),손종수 ( Jong-soo Sohn ),정인정 ( In-jeong Chung ) 한국정보처리학회 2010 한국정보처리학회 학술대회논문집 Vol.17 No.2

오늘날의 인터넷은 웹 2.0 의 출현으로 인하여 콘텐츠의 생산주체가 서비스 제공자에서 서비스 수요자인 사용자들로 변화되고 있다. 이에 따라 사용자들의 경험은 콘텐츠의 품질에 큰 영향을 미치고 있으며 소셜 네트워크에서 취득한 콘텐츠는 검색으로 취득한 콘텐츠보다 신뢰를 받고 있다. 본 논문에서는 소셜 네트워크를 기반으로 사용자들에게 양질의 콘텐츠를 추천하기 위한 방법과 그 개발을 보인다. 소셜 네트워크는 XML 기반의 사용자 프로파일 기술 언어인 FOAF 를 이용하여 수집하며 이를 통해 사용자와 사용자 사이의 관계를 수집한다. 그리고 웹 콘텐츠 출판언어인 RSS 를 이용하여 각 사용자들이 블로그 등을 통해 배포한 콘텐츠를 수집한다. 본 논문에서 보이는 시스템은 FOAF 와 RSS 를 기초로 입력된 키워드에 대해 사용자와 콘텐츠의 관계를 분석하고 이를 통해 콘텐츠를 추천하는 기능을 가진다. 본 논문에서 보이는 시스템은 전통적인 콘텐츠 추천 시스템과 달리 사용자가 속한 소셜 네트워크에서 콘텐츠 생산자가 대한 중요도가 반영되므로 보다 신뢰성 있는 결과를 얻을 수 있다.

Computer simulation of stereochemical structure of biodegradable poly(d,l-lactide-co-l-lactide)

Pei-Hua He,Yan Wu,Ruo-Feng Wu 한국물리학회 2007 Current Applied Physics Vol.7 No.s1

poly(D,L-lactide-co-L-lactide) (PDLLA). The Monte Carlo model is set up according to the reactivity probabilities of two kinds of isomerRR and SS during ring-opening chain propagation. The simulation results for Tetrads and Hexads intensities are in good agreement withexperimental results for13C NMR. Some other important parameters for the stereochemical structure of PDLLA are also obtained fromRun numbers. The inuence of reactivity ratiorand feed ratiop on the stereochemical structure is analyzed and discussed in detail. Thiscomputer simulation method has proved to be a convenient method for establishing structureproperties relationships of certain poly-mers whose stereoregularity can be adjusted, such as PDLLA.

Gemcitabine Inhibits the Progression of Pancreatic Cancer by Restraining the WTAP/MYC Chain in an m6A-Dependent Manner

Pei Cao,Weigang Zhang,Junyi Qiu,Zuxiong Tang,Xiaofeng Xue,Tingting Feng 대한암학회 2024 Cancer Research and Treatment Vol.56 No.1

Purpose Pancreatic cancer (PC) is a common malignant tumor of the digestive system, and its 5-year survival rate is only 4%. N6-methyladenosine (m6A) RNA methylation is the most common post-transcriptional modification and dynamically regulates cancer development, while its role in PC treatment remains unclear.Materials and Methods We treated PC cells with gemcitabine and quantified the overall m6A level with m6A methylation quantification. Real-time quantitative reverse transcription polymerase chain reaction and Western blot analyses were used to detect expression changes of m6A regulators. We verified the m6A modification on the target genes through m6A-immunoprecipitation (IP), and further <i>in vivo</i> experiments and immunofluorescence (IF) assays were applied to verify regulation of gemcitabine on Wilms’ tumor 1–associated protein (WTAP) and MYC.Results Gemcitabine inhibited the proliferation and migration of PC cells and reduced the overall level of m6A modification. Additionally, the expression of the “writer” WTAP was significantly downregulated after gemcitabine treatment. We knocked down WTAP in cells and found target gene MYC expression was significantly downregulated, m6A-IP also confirmed the m6A modification on MYC. Our experiments showed that m6A-MYC may be recognized by the “reader” IGF2BP1. <i>In vivo</i> experiments revealed gemcitabine inhibited the tumorigenic ability of PC cells. IF analysis also showed that gemcitabine inhibited the expression of WTAP and MYC, which displayed a significant trend of co-expression.Conclusion Our study confirmed that gemcitabine interferes with WTAP protein expression in PC, reduces m6A modification on MYC and RNA stability, thereby inhibiting the downstream pathway of MYC, and inhibits the progression of PC.

Dynamic Heart

Pei Lin,Feng Shu 한국디자인학회 2023 한국디자인학회 국제초대전도록 Vol.2023 No.10

Dynamic reliability of structures: the example of multi-grid composite walls

Pei Liu,Qian-Feng Yao 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.4

Based on damage accumulation of multi-grid composite walls, a method of dynamic reliability estimations is proposed. The multi-grid composite wall is composed of edge frame beam, edge frame columns, grid beams, grid columns and filling blocks. The equations including stiffness, shear forces at filling blocks cracking and multi-grid composite walls yielding, ultimate displacement, and damage index are obtained through tests of 13 multi-grid composite wall specimens. Employing these equations in reliability calculations, procedures of dynamic reliability estimations based on damage accumulation of multi-grid composite walls subjected to random earthquake excitations are proposed. Finally the proposed method is applied to the typical composite wall specimen subjected to random earthquake excitations which can be specified by a finite number of input random variables. The dynamic reliability estimates, when filling blocks crack under earthquakes corresponding to 63% exceedance in 50 years and when the composite wall reach limit state under earthquakes corresponding to 2-3% exceedance in 50 years, are obtained using the proposed method by taking damage indexes as thresholds. The results from the proposed method which show good agreement with those from Monte-Carlo simulations demonstrate the proposed method is effective.

A FREE BREATHING IMPEDANCE RHEOGRAM APPARATUS MADE OF MICROPROCESSOR

Feng Jian Hua,Zhang Xin Chao,Zheng Wei,Jin Pei Xuan,Bai Yan Qiou 대한전자공학회 1992 대한전자공학회 Conference Vol.1992 No.2