Preparation and Properties of Water-Resistant Antibacterial Curcumin/Silver Composite Nanofiber

Meiping Chen,Chao Ma,Change Zhou,Zhiguang Li,Rong Li 한국섬유공학회 2023 Fibers and polymers Vol.24 No.11

The water-resistant antibacterial PVA nanofibers containing curcumin (Cur) and silver nanoparticles (AgNPs) were prepared by electrospinning, and the AgNps were prepared by in situ reduction in the spinning solution. The prepared PVA nanofibers were measured by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectrophotometer (FT-IR). The breathable, hygroscopic, antibacterial, anti-inflammatory, and antioxidants functions of the prepared nanofibers were evaluated. The results indicated that the prepared nanofiber membrane has high swelling rate, moisture permeability, good mechanical properties, good biocompatibility, anti-inflammatory, antioxidant, and bacteriostatic activities with no cytotoxicity. Curcumin and AgNPs in the prepared nanofiber have effect on antibacterial activity and wound healing. The functionalized silver nanoparticles developed have effective activities against both Gram-negative bacteria and Gram-positive bacteria. In short, Cur/AgNPs composite nanofibers can be used as a potential medical dressing with antibacterial, anti-inflammatory, and antioxidant properties.

Dual Mediation Model of Major Awareness and Hope Between Learning Motive and Academic Achievement in College Students

Meiping Wu,이창식 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.10

Students majoring in health education are unable to reach the level of a college major because they do not know how their major is connected to the workplace and therefore, what and to what extent they should learn in college. Accordingly, research on awareness of the major and related variables is needed. This study aims to suggest ways to increase the academic achievement of college students by identifying the dual mediators effect of major awareness and hope in the link between learning motive and academic achievement. A total of 314 respondents were purposively sampled from undergraduates and graduates of one of the colleges in Guangdong of China, and data were collected using a questionnaire survey method. The collected data were analyzed utilizing SPSS PC+ Win. Ver. 26.0 and PROCESS macro Ver. 4.2. The applied statistical techniques were frequency analysis, reliability analysis, correlation analysis, and dual mediation effect analysis. The dual mediating effect was verified by the bootstrap method. First, research findings revealed that there was a positive and significant correlation between learning motive, major awareness, hope, and academic achievement. Second, it was revealed that major awareness and hope were dual mediators in the association between learning motive and academic achievement. It was confirmed that learning motive has a positive relation with academic achievement via major awareness and hope. To improve academic achievement for college students, program development and implementation to improve major awareness and hope were suggested.

日语基础写作课程的教学设计与实践研究

魏美平(Meiping Wei) YIXIN 출판사 2023 教育教学研究论丛 Vol.1 No.2

为了改变学生被动式日语学习的现象,本论文对在日语学习过程中驱动力的产生问题进行了考察和分析。遵循认知过程的自然规律,运用学习内驱力产生机制及多种教学方法进行了教学设计。以学习过程的“知识连续体”概念为基础,笔者在日语基础写作课程的教学设计中将整个学期分成五个阶段,并将每个阶段中的课堂均设为翻转课堂。经过半年的教学实践,笔者对课后反馈、课后的教学反思日志进行了考察并通过问卷调查对教学实践进行了评价。通过分析发现学生的学习观滞后是影响教学改革的因素之一,另外对话式互动型课堂在学生主动学习方面起到了促进作用,对学生在学习过程中内驱动力的产生有一定帮助。 In order to change the phenomenon of passive Japanese learning, this paper investigates and analyzes the generation of driving force in the process of Japanese learning. Following the natural law of the cognitive process, the teaching design is carried out by using the mechanism of learning internal drive and various teaching methods. Based on the concept of “knowledge continuum” in the learning process, the author divides the entire semester into five stages in the teaching design of the basic Japanese writing course, and sets the classroom in each stage as a flipped classroom. After half a year of teaching practice, the author inspected the after-class feedback, the after-class teaching reflection log, and evaluated the teaching practice through a questionnaire survey. Through the analysis, it is found that the lagging of students’ learning concept is one of the factors affecting the teaching reform. In addition, the dialogue and interactive classroom has played a role in promoting students’ active learning, which is helpful to the generation of internal driving force in the learning process of students.

Engineering Realization of Full Attitude System Based On GPS Carrier Phase and MEMS IMU

Kanghua Tang,Meiping Wu,Xiaoping Hu 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

This paper describes the design and realization of full attitude system based on MEMS IMU and GPS carrier phase. The work can be divided into two parts: First, initial heading is determined by using two GPS receivers. And this paper discusses the usage of space geometry conditions to reduce the range of ambiguity search. The method presented in this paper was tested on the static. On the static condition, an accuracy better than 0.06 degrees for heading for 3.48m long baseline has been achieved. Integration of GPS and low cost MEMS IMU are used to realize the real-time heading attitude system. Second, level attitude (pitch and roll) is determined using the method of frequency-velocity for the feedback control. At the same time, the method using the attitude based on MEMS IMU to help determination of the range of ambiguity search is proposed. The results done on the sea show that an alternative means to provide real-time, cost-effective, accurate and reliable attitude information for attitude surveys. Though motivated by a big ships application, the design can be applied to other vehicles.

GO Enhanced, Irradiation Cross-linked UHMWPE/VE Nanocomposites with Increased Hardness and Scratch Resistance

Jitai Han,Meiping Wu,Weipeng Duan 한국고분자학회 2020 폴리머 Vol.44 No.5

In this study, a way to reinforce the properties of ultrahigh molecular weight polyethylene (UHMWPE)/vitamin E (VE) nanocomposites was put to use by adding graphene oxide (GO) combined with gamma-ray irradiation cross-linking. The influences of adding GO and irradiation cross-linking treatment on the thermal and mechanical properties were studied, especially the effect of GO doping on irradiation cross-linked UHMWPE/VE nanocomposites. The results show that GO filling has no significant effect on melting temperature and gel content decreased at a small degree, but the crystallinity has been improved obviously. In addition, the ball indentation hardness and scratch resistance were enhanced as well. The comprehensive effects of improved crystallinity and reduced cross-linking degree as well as the good mechanical properties of GO doping were responsible for this result.

Fabrication of Stable Fluorine-Free Hydrophobic Cotton Fabrics with Prominent Antibacterial Property

Fengyi Qian,Meiping Chen,Zhiguang Li,Change Zhou,Rong Li,Xuehong Ren 한국섬유공학회 2023 Fibers and polymers Vol.24 No.11

Multifunctional cotton fabrics with antibacterial property and hydrophobicity were prepared using surface modification. Cotton fabrics were treated with the coating solution containing N-halamine compound poly[5,5-dimethyl-3-(3’-triethoxysilylpropyl) hydantoin] (PSPH) and TiO2 nanoparticles, followed by treated with polydimethylsiloxane (PDMS) to reduce the surface energy of cotton fabrics. The prepared cotton fabrics were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), and X-ray diffractometry (XRD). After chlorination, the prepared cotton fabrics exhibited excellent hydrophobicity with contact angle of 143°. The antibacterial results demonstrated that the prepared cotton fabrics had excellent antibacterial activity and could completely inactivate 4.54 cfu/sample of S.aureus and 4.92 cfu/sample of E. coli O157:H7 within 30 min of contact. The treated cotton fabrics also possessed robust stability under washing, UV light irradiation, and abrasion. Moreover, the breaking strength and air permeability of cotton fabric could maintain to the required values for practical application after treatment.

The Antibacterial and Hydrophobic Cotton Fabrics Constructed by Multifunctional Polysiloxane and TiO2 Nanoparticles

Fengyi Qian,Meiping Chen,Change Zhou,Zhiguang Li,Rong Li,Xuehong Ren 한국섬유공학회 2023 Fibers and polymers Vol.24 No.2

Multifunctional polysiloxane was synthesized by introducing N-halamine compound precursor and stearyl methacrylateinto polyhydromethylsiloxane, and characterized by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance(NMR). Cotton fabrics with antibacterial and hydrophobic properties were prepared via a simple one-pot method with thesynthesized polysiloxane and rutile TiO2nanoparticles. The prepared cotton fabrics was characterized by scanning electronmicroscopy (SEM), FT-IR, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results demonstratedthat prepared cotton fabrics could inactivate 3.9 × 106cfu/sample of S. aureus and 4.8 × 106cfu/sample of E. coli O157:H7within 30 min of contact time, and the water contact angle of the treated fabrics was 133°. The prepared cotton fabrics alsoexhibited excellent stability against 50 abrasion cycles. After 50 washing cycles, 72% of the chlorine content on preparedcotton fabrics could be recovered after rechlorination. And the antibacterial hydrophobic cotton fabrics loaded with TiO2possessed higher UV stability than cotton fabrics only treated with PTSAMS-Cl. Furthermore, the breaking strength ofantibacterial hydrophobic cotton fabrics was decreased while the wrinkle resistance was improved.

Study on Corrosion Resistance and Bio‑Tribological Behavior of Porous Structure Based on the SLM Manufactured Medical Ti6Al4V

Peipei Lu,Meiping Wu,Xin Liu,Weipeng Duan,Jitai Han 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.8

Titanium and its alloy, especially Ti6Al4V is one of the most widely used metal due to its excellent properties. Selectivelaser melting, which is known as additive manufacturing is considered as a suitable method to manufacture Ti6Al4V parts. To print a more analogous Ti6Al4V artificial bone, laser power was changed by taking volume porosity, corrosion resistanceand wear resistance into consideration. The testing results showed that sample printed using 200 W showed a relative optimalcorrosion resistance and volume porosity in all these five samples (the value of corrosion voltage is − 0.352 V), while itshowed the best bio-tribological behavior, and its wear volume is as low as 5.90 μm3. Summarize the 5 sets of experimentalsamples, the Ti6Al4V part printed using 180–200 W were the most prominent in the test, its overall performance was, indeed,best fit to print artificial Ti6Al4V bone, because it is similar to bone, there are a large number of microporous structures.

[교정] GO 강화 및 조사 가교된 UHMWPE/VE 나노복합재료의 경도와 스크래치 저항의 증가

Jitai Han,Meiping Wu,Weipeng Duan 한국고분자학회 2020 폴리머 Vol.44 No.6

Effect of Carbon Nanotubes on the Transport and Retention of Bacteria in Saturated Porous Media

Yang, Haiyan,Tong, Meiping,Kim, Hyunjung American Chemical Society 2013 Environmental science & technology Vol.47 No.20

<P>This study investigated the influence of carbon nanotubes (CNTs) on the transport and retention behaviors of bacteria (<I>E. coli</I>) in packed porous media at both low and high ionic strength in NaCl and CaCl<SUB>2</SUB> solutions. At low ionic strengths (5 mM NaCl and 0.3 mM CaCl<SUB>2</SUB>), both breakthrough curves and retained profiles of bacteria with CNTs (both 5 and 10 mg L<SUP>–1</SUP>) were equivalent to those without CNTs, indicating the presence of CNTs did not affect the transport and retention of <I>E. coli</I> at low ionic strengths. The results were supported by those from cell characterization tests (i.e., viability, surface properties, sizes), which showed no significant difference between with and without CNTs. In contrast, breakthrough curves of bacteria with CNTs were lower than those without CNTs at high ionic strengths (25 mM NaCl and 1.2 mM CaCl<SUB>2</SUB>), suggesting that the presence of CNTs decreased cell transport at high ionic strengths. The enhanced bacterial deposition in the presence of CNTs was mainly observed at segments near the column inlet, leading to much steeper retained profiles relative to those without CNTs. Additional transport experiments conducted with sand columns predeposited with CNTs revealed that the codeposition of bacteria with CNTs, as well as the deposition of the cell–CNTs cluster formed in cell suspension due to cell bridging effect, largely contributed to the increased deposition of bacteria at high ionic strengths in porous media.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2013/esthag.2013.47.issue-20/es4022415/production/images/medium/es-2013-022415_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es4022415'>ACS Electronic Supporting Info</A></P>