Tribology Property of Benzoxazine–Bismaleimide Composites with Hyperbranched Polysilane-Grafted Multi-Walled Carbon Nanotubes

YUAN JIA,HONGXIA YAN,Song Li,Tianye Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6

To reveal the wear mechanism of hyperbranched polysilane (HBPSi) grafted multi-walled carbon nanotubes (HBPSi–MWCNTs) modified benzoxazine–bismaleimide (BOZ–BMI) resin (HBPSi– MWCNTs/BOZ–BMI), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) were employed. The results indicated that the suitable addition of HBPSi–MWCNTs could largely enhance the tribological properties of BOZ– BMI composites. The worn surface of the composites showed that the severe wear of the BOZ– BMI resin was converted from adhesive wear to abrasive wear with the addition of HBPSi– MWCNTs. The excellent tribological properties can be attributed to the improved interfacial adhesion between HBPSi–MWCNTs and the BOZ–BMI resin matrix. The TGA demonstrated that the composite with 0.8 wt.% HBPSi–MWCNTs exhibits better thermal resistance; thus, it can inhibit adhesive wear during the friction process. The XPS spectra and the surface energy showed that the HBPSi–MWCNTs could be exposed on the worn surface of the composite to improve the anti-wear capacity of the composites further.

The Inhibitory Effect of Plant Water Extracts on Tyrosinase and Elastase

Jia Yuan,Inshik Park 한국식품영양학회 2013 한국식품영양학회 학술대회논문집(학술심포지움) Vol.2013 No.06

Good to Great : Build strong and vital teams

Jia Yuan,Runtian Jing 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.1

Single-Source-Precursor Synthesis of Hafnium-Containing Ultrahigh-Temperature Ceramic Nanocomposites (UHTC-NCs)

Yuan, Jia,Hapis, Stefania,Breitzke, Hergen,Xu, Yeping,Fasel, Claudia,Kleebe, Hans-Joachim,Buntkowsky, Gerd,Riedel, Ralf,Ionescu, Emanuel American Chemical Society 2014 Inorganic chemistry Vol.53 No.19

<P>Amorphous SiHfBCN ceramics were prepared from a commercial polysilazane (HTT 1800, AZ-EM), which was modified upon reactions with Hf(NEt<SUB>2</SUB>)<SUB>4</SUB> and BH<SUB>3</SUB>·SMe<SUB>2</SUB>, and subsequently cross-linked and pyrolyzed. The prepared materials were investigated with respect to their chemical and phase composition, by means of spectroscopy techniques (Fourier transform infrared (FTIR), Raman, magic-angle spinning nuclear magnetic resonance (MAS NMR)), as well as X-ray diffraction (XRD) and transmission electron microscopy (TEM). Annealing experiments of the SiHfBCN samples in an inert gas atmosphere (Ar, N<SUB>2</SUB>) at temperatures in the range of 1300–1700 °C showed the conversion of the amorphous materials into nanostructured UHTC-NCs. Depending on the annealing atmosphere, HfC/HfB<SUB>2</SUB>/SiC (annealing in argon) and HfN/Si<SUB>3</SUB>N<SUB>4</SUB>/SiBCN (annealing in nitrogen) nanocomposites were obtained. The results emphasize that the conversion of the single-phase SiHfBCN into UHTC-NCs is thermodynamically controlled, thus allowing for a knowledge-based preparative path toward nanostructured ultrahigh-temperature stable materials with adjusted compositions.</P><P>Amorphous SiHfBCN ceramics were prepared from a suitable single-source precursor. Annealing experiments of the SiHfBCN samples in an inert gas atmosphere at temperatures of 1300−1700 °C led to their conversion nanostructured UHTC-NCs, such as HfC/HfB<SUB>2</SUB>/SiC nanocomposites (in argon) and HfN/Si<SUB>3</SUB>N<SUB>4</SUB>/SiBCN nanocomposites (in nitrogen), thus revealing a convenient preparative approach to nanostructured ultrahigh-temperature stable materials starting from a greatly flexible single-source precursor.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2014/inocaj.2014.53.issue-19/ic501512p/production/images/medium/ic-2014-01512p_0016.gif'></P>

Research on Thymopentin Loaded Oral N-Trimethyl Chitosan Nanoparticles

Yuan, Xiao-Jia,Zhang, Zhi-Rong,Song, Qing-Guo,He, Qin The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.9

Peptides, although high efficacy and specificity in their physiological function, usually have low therapeutical activities due to their poor bioavailability when administrated orally. Nanoparticles have been regarded as a useful vector for targeted drug delivery system because they can protect drug from being degraded quickly and pass the gastrointestinal barriers. Here we described a novel oral N-trimethyl chitosan nanoparticles formulation containing thymopentin (Tp5-TMC-NP). N-trimethyl chitosan (TMC) was synthesized and then used to prepare Tp5-TMC-NP by ionotropic gelation. A three-factor, five-level CCD (Central Composite Design) design was used in the optimization procedure, with HPLC as the analyzing method. The resulting Tp5-TMC-NP had a regular spherical surface and a narrow particle size range with a mean diameter of 110.6 nm. The average entrapment efficiency was 78.8%. The lyophilized Tp5-TMC-NP formulation was stable in $4^{\circ}C\;or\;-20^{\circ}C$ after storage of 3 months without obvious changes in morphology, particle size, pH and entrapment ratio. The results of the flow cytometer determination showed that the ratio of $CD4^+/CD8^+$ of Wistar female rat given Tp5-TMC-NP (ig) was 2.59 time that of the group given Tp5 (ig).

Fabrication of PHBV/Keratin Composite Nanofibrous Mats for Biomedical Applications

Yuan, Jiang,Xing, Zhi-Cai,Park, Suk-Woo,Geng, Jia,Kang, Inn-Kyu,Yuan, Jiang,Shen, Jian,Meng, Wan,Shim, Kyoung-Jin,Han, In-Suk,Kim, Jung-Chul The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.11

Keratin is an important protein used in wound healing and tissue recovery. In this study, keratin was modified chemically with iodoacetic acid (IAA) to enhance its solubility in organic solvent. Poly(hydroxybutylate-co-hydroxyvalerate) (PHBV) and modified keratin were dissolved in hexafluoroisopropanol (HFIP) and electrospun to produce nanofibrous mats. The resulting mats were surface-characterized by ATR-FTIR, field-emission scanning electron microscopy (FE-SEM) and electron spectroscopy for chemical analysis (ESCA). The pure m-keratin mat was cross-linked with glutaraldehyde vapor to make it insoluble in water. The biodegradation test in vitro showed that the mats could be biodegraded by PHB depolymerase and trypsin aqueous solution. The results of the cell adhesion experiment showed that the NIH 3T3 cells adhered more to the PHBV/m-keratin nanofibrous mats than the PHBV film. The BrdU assay showed that the keratin and PHBV/m-keratin nanofibrous mats could accelerate the proliferation of fibroblast cells compared to the PHBV nanofibrous mats.

Mitogen-Activated Protein Kinase Signal Transduction in Solid Tumors

Lei, Yuan-Yuan,Wang, Wei-Jia,Mei, Jin-Hong,Wang, Chun-Liang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

Mitogen-activated protein kinase (MAPK) is an important signaling pathway in living beings in response to extracellular stimuli. There are 5 main subgroups manipulating by a set of sequential actions: ERK(ERK1/ERK2), c-Jun N(JNK/SAPK), p38 MAPK($p38{\alpha}$, $p38{\beta}$, $p38{\gamma}$ and $p38{\delta}$), and ERK3/ERK4/ERK5. When stimulated, factors of upstream or downstream change, and by interacting with each other, these groups have long been recognized to be related to multiple biologic processes such as cell proliferation, differentiation, death, migration, invasion and inflammation. However, once abnormally activated, cancer may occur. Several components of the MAPK network have already been proposed as targets in cancer therapy, such as p38, JNK, ERK, MEK, RAF, RAS, and DUSP1. Among them, alteration of the RAS-RAF-MEK-ERK-MAPK(RAS-MAPK) pathway has frequently been reported in human cancer as a result of abnormal activation of receptor tyrosine kinases or gain-of-function mutations in genes. The reported roles of MAPK signaling in apoptotic cell death are controversial, so that further in-depth investigations are needed to address these controversies. Based on an extensive analysis of published data, the goal of this review is to provide an overview on recent studies about the mechanism of MAP kinases, and how it generates certain tumors, as well as related treatments.

Professionals’ experiences and attitudes toward use of Traditional Chinese Medicine in hospice palliative inpatient care units: A multicenter survey in Taiwan

Yu-Jia Lin,Hsiao-Ting Chang,Ming-Hwai Lin,Ru-Yih Chen,Ping-Jen Chen,Wen-Yuan Lin,Jyh-Gang Hsieh,Ying-Wei Wang,Chung-Chieh Hu,Yi-Sheng Liou,Tai-Yuan Chiu,Chun-Yi Tu,Yi-Jen Wang,Bo-Ren Cheng,Tzeng-Ji Ch 한국한의학연구원 2021 Integrative Medicine Research Vol.10 No.2

Background: Medical staff may have difficulties in using conventional medicine to manage symptoms among terminally ill patients, including adverse effects of the treatment. Traditional Chinese medicine (TCM) is regarded as a complementary or alternative medicine, and has been increasingly used in the field of palliative medicine in recent years. This study aimed to investigate the experiences of and attitudes toward using TCM among palliative care professionals, and to provide preliminary information about its use in palliative care. Methods: This was a cross-sectional survey study conducted in eight inpatient hospice wards in Taiwan between December 2014 and February 2016. The questionnaire was self-administered, and was analyzed with descriptive statistics including Pearson’s Chi-square test and Fisher’s exact test. Results: A total of 251 palliative care professionals responded to the questionnaire, of whom 89.7% and 88.9% believed that the use of TCM could improve the physical symptoms and quality of life in terminally ill patients, respectively. Overall, 59.8%, of respondents suggested that TCM had rare side effects, and 58.2% were worried that TCM could affect the liver and kidney function of patients. In total, 89.7% and 88.0% of professionals agreed there were no suitable clinical practice guidelines and educational programs, respectively, for TCM use in palliative care. Conclusions: Most of the respondents agreed there was insufficient knowledge, skills-training, and continuing education on the use of TCM in terminally ill patients in Taiwan. These results show that to address patient safety considerations, guidelines about use of TCM in palliative care should be established.

Effect of Fluorescence Light on Phenolic Compounds and Antioxidant Activities of Soybeans (Glycine max L. Merrill) during Germination

Ming Yuan,Xuejing Jia,ChunBang Ding,Haiqiong Zeng,Lei Du,Shu Yuan,Zhongwei Zhang,Qi Wu,Chao Hu,Jing Liu 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.5

Effects of light on phenolic compounds and antioxidant activities during germination of soybean seeds were studied. Soybean seeds were germinated in the presence and absence of light. Chlorophylls and morphological characteristics of sprouts were evaluated daily. Antioxidant activities were determined using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and ferric reducing activity power methods. Morphological characteristics of light-grown sprouts were superior to dark-grown sprouts and the metabolism of phenolic compounds was regulated by light. Light treatment improved accumulation of phenolic compounds in soybean sprouts and increased antioxidant activities. The optimum harvest time of light-grown sprouts was on the seventh day when sprouts achieved the best nutraceutical value. Green sprouts can serve as a good vegetable source for the human diet.

Dark current suppression of amorphous selenium based photosensors by the ZnO hole blocking layer

Tung-Yuan Yu,Fu-Ming Pan,Cheng-Yi Chang,Tien Hu,Jenn-Fang Chen,Jia-Feng Wang,Jia-Feng Wang,Cheng-Lu Lin,Te-Ming Chen 한국물리학회 2014 Current Applied Physics Vol.14 No.5

To study the influence of defects in the hole blocking layer (HBL) on the dark current of amorphous selenium (a-Se) based photosensors, we prepared ZnO thin films by reactive sputter deposition (RSD) for the use as the HBL of the photosensors. The ZnO HBL layers prepared with different oxygen flow rates were characterized by X-ray photoelectron spectroscopy, Raman scattering analysis and photoluminescence, indicating that the density of oxygen vacancies in the ZnO thin films is significantly affected by the oxygen flow rate. The deep level transient spectroscopy measurement reveals two hole trap levels present in the RSD deposited ZnO thin films; one is at 0.94 eV and the other at 0.24 eV above the valence band edge. The electrical performance of the a-Se photosensor is largely influenced by the amount of oxygen vacancies in the ZnO thin film. The a-Se photosensor with the ZnO HBL of the most oxygen vacancies has the lowest dark current and demonstrates the highest breakdown field.