New triterpenoids from Staphylea bumalda flower buds and their neuroprotective activity against H2O2-induced injury in vitro

Zheng-Xi Zhang,Kun Feng,Xian-Jin Sui,Wen-Shu Wang,Lin Wang,Dong-Hong Wang,Xiao-Min Luo,Xiao-Fei Chen 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

Four new acylated triterpene glycosides with aliphatic chains (4–7) as well as five known triterpenoids were isolated from the flower buds of Staphylea bumalda with bioassay guidance. Their structures were determined on the basis of spectral techniques, including IR, 1D and 2D NMR, and HR-APCI-MS. Most compounds (except 8) were isolated from S. bumalda for the first time. Additionally, the neuroprotective effects of 1 and 4–9 on suckling rat primary cultured hippocampal neurons against H2O2-induced injury were evaluated in vitro. The four new triterpenoids (4–7) showed neuroprotective effects, which increased the cell viability to over 74% at different concentrations, which was higher than the negative control (59%), while compounds 1 and 8–9 exhibited cytotoxic activity.

Soy Isoflavones and Osteoporotic Bone Loss: A Review with an Emphasis on Modulation of Bone Remodeling

Xi Zheng,Sun-Kyeong Lee,Ock K. Chun 한국식품영양과학회 2016 Journal of medicinal food Vol.19 No.1

Osteoporosis is an age-related disorder that affects both women and men, although estrogen deficiency induced by menopause accelerates bone loss in older women. As the demographic shifts to a more aged population, a growing number of men and women will be afflicted with osteoporosis. Since the current drug therapies available have multiple side effects, including increased risk of developing certain types of cancer or complications, a search for potential nonpharmacologic alternative therapies for osteoporosis is of prime interest. Soy isoflavones (SI) have demonstrated potential bone-specific effects in a number of studies. This article provides a systematic review of studies on osteoporotic bone loss in relation to SI intake from diet or supplements to comprehensively explain how SI affect the modulation of bone remodeling. Evidence from epidemiologic studies supports that dietary SI attenuate menopause-induced osteoporotic bone loss by decreasing bone resorption and stimulating bone formation. Other studies have also illustrated that bone site-specific trophic and synergistic effects combined with exercise intervention might contribute to improve the bioavailability of SI or strengthen the bonespecific effects. To date, however, the effects of dietary SI on osteoporotic bone loss remain inconclusive, and study results vary from study to study. The current review will discuss the potential factors that result in the conflicting outcomes of these studies, including dosages, intervention materials, study duration, race, and genetic differences. Further well-designed studies are needed to fully understand the underlying mechanism and evaluate the effects of SI on osteoporosis in humans.

Anthocyanin-Rich Blackcurrant Extract Attenuates Ovariectomy-Induced Bone Loss in Mice

Xi Zheng,Sewhan Mun,이상길,Terrence M. Vance,Patrice Hubert,Sung I. Koo,Sun-Kyeong Lee,Ock K. Chun 한국식품영양과학회 2016 Journal of medicinal food Vol.19 No.4

Although several animal and cell studies have indicated that blackcurrant anthocyanins exert antioxidative andanti-inflammatory properties, which could potentially improve bone mass, the effect of blackcurrant on bone health has notbeen reported yet. Thus, this study was aimed to evaluate the effect of blackcurrant anthocyanins on bone mass in an estrogendeficiency mouse model. Fourteen-week-old C57BL/6J mice (n = 54) were ovariectomized or sham operated. The ovariectomizedmice were divided into two groups, basal diet (OVX) or basal diet with 1% anthocyanin-rich blackcurrant extract(OVX+BC), and sacrificed at 4, 8, and 12 weeks. Femoral bone mineral density (BMD) and trabecular bone volume by dualenergyX-ray absorptiometry and micro-computed tomography, respectively, and serum bone markers were measured. Ovariectomy significantly reduced BMD and trabecular bone volume at all time points (P < .05). Blackcurrant supplementationattenuated ovariectomy-induced bone loss measured by BMD and trabecular bone volume at 8 weeks (P = .055 andP = .057) and the effect was more pronounced at 12 weeks (P = .053 and P < .05). Ovariectomy and blackcurrant treatment didnot alter serum biomarkers of bone formation and resorption. Bone marrow cells extracted from OVX mice significantlyinduced osteoclast-like (OCL) cell formation compared with cells from sham controls (P < .05). Blackcurrant treatmentdecreased the number of TRAP(+) OCL compared with OVX mice at 8 and 12 weeks (P < .05). Furthermore, blackcurrantsupplementation reduced bone resorption activity when measured by resorption pit assay, compared with OVX group(P < .05). These results demonstrate that blackcurrant may be effective in mitigating osteoclast-induced postmenopausalbone loss.

Acetylcholinesterase Inhibitive Activity-Guided Isolation of Two New Alkaloids from Seeds of Peganum Nigellastrum Bunge by an In Vitro TLC- Bioautographic Assay

Xi-yuan Zheng,Chang-hong Wang,Zi-jia Zhang,Gui-xin Chou,Tao Wu,Xue-mei Cheng,Zheng-tao Wang 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.9

Acetylcholinesterase inhibitors (AChEIs) currently form the basis of the newest drugs available for the treatment of Alzheimer's disease. For the aim of screening effective AChEIs, the methanol extracts of the seeds of genus Peganum were found to show significant inhibitory activity of acetylcholinesterase enzyme (AChE) using an in vitro TLC-bioautographic assay. In further studies to seed of P. nigellastrum Bunge, activity-guided fractionation led to the isolation of two new alkaloids nigellastrine Ⅰ (9) and nigellastrine Ⅱ (10), and along with eight known alkaloids, vasicinone (1), vasicine (2), harmine (3), deoxyvasicinone (4), deoxyvasicine (5), harmaline (6), harmol (7), harman (8), in which harmol and harman were first isolated from species P. nigellastrum Bunge. As active constituents, all compounds showed good inhibitory activities against AChE. The results of in vitro semi-quality TLC-bioautographic assay showed that harmine, harmaline and harmol displayed a similar AChE inhibitive activities comparing to galanthamine. These results indicated that these alkaloids in P. nigellastrum Bunge could be a potent class of AChEIs.

Mesenchymal Stem Cells on a Decellularized Cartilage Matrix for Cartilage Tissue Engineering

Xi-Fu Zheng,Shi-Bi Lu,Wei-Guo Zhang,Shu-Yun Liu,Jing-Xiang Huang,Quan-Yi Guo 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.3

An ideal scaffold for cartilage tissue engineering should be biomimetic in not only its biochemical composition, but also in the morphological structure of the scaffold. In this study, we fabricated a scaffold with an oriented structure using a nanofibrous articular cartilage extracellular matrix (ACECM), in which the ACECM was used to mimic the biochemical composition and oriented structure of articular cartilage. Histology analysis showed that the scaffold contained cartilage ECM (GAGs and collagen II). Scanning electron microscopy (SEM) indicated that the scaffolds were composed of nanofibers and possessed vertical microtubules. Chondrogenic differentiation-induced mesenchymal stem cells (MSCs) were seeded on the scaffold in vitro. SEM showed that MSCs proliferated well and aligned along the vertical microtubules,which mimicked the orientation of deep zone articular cartilage. A cell proliferation assay and live/dead cell staining demonstrated that the ACECM possessed good cell affinity, which favored cell adherence and proliferation. The MSCs that had been labeled with the fluorescent dye PKH26 and seeded on scaffolds were implanted into nude mice. The differentiated cells/ACECM implants formed cartilage-like tissue 4 weeks after implantation, and stained positive for collagen type II and toluidine blue. In addition,the in vivo fluorescent images verified that the MSCs in the implants were the labeled MSCs. These results demonstrated that the oriented ACECM scaffolds hold great promise for use in cartilage tissue engineering applications.

CNT/Cu 복합입자 소결코팅의 비등열전달 특성에 대한 연구

정희여(Xi Ru Zheng),애드워드(E.J.Pialago),유다영(Da Yong You),박찬우(Chan Woo Park) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7

In the present study, the effect of CNTs coating on boiling heat transfer is being investigated under a pool of saturated R134a. The coating of metal surface with carbon nanotubes (CNTs) has been studied for the heat transfer enhancement of the boiling and condensation of refrigerant. we make the multiwall carbon nanotube/copper composite powder by th attrition milling, and the multiwall carbon nanotube/copper composite powder, which has been coated on the copper wafer by electrostatic powder coating and sintered with electric furnace. The influence of the temperature of the sintering, the ball milling time for the powder fabrication and the CNTs content on the heat transfer was studied. Finally, the boiling performance of a CNTs coated surface is compared with that of bare surface, pure copper powder coated surface by sintering.

열전달 촉진을 위한 탄소나노튜브(CNT)/금속 복합체 소결 코팅에 관한 연구

정희여 ( Xi Ru Zheng ),김민수 ( Min Soo Kim ),박찬우 ( Chan Woo Park ) 한국복합재료학회 2013 Composites research Vol.26 No.6

냉매의 비등이나 응축같은 열전달 향상을 위하여 금속 표면위에 탄소나노튜브(CNT)를 코팅하는 것을 연구하였다. 다중벽 탄소나노튜브/구리 복합소재는 어트리션 볼밀에 의해서 제작되었으며, 정전 도장 장치로 복합 분말을 구리 기판위에 코팅한 후 전기로에서 소결하였다. 본 논문에서는 CNT/Cu 코팅 표면의 분석 및 소결전후의 탄소나노튜브의 변화를 파악하기 위하여 샘플들을 주사전자현미경, EDAX, 라만분광법에 의해 분석하였다. 아울러 열전달 촉진은 비등열전달로 확인하였다. The coating of metal surface with carbon nanotubes (CNTs) has been studied for the heat transfer enhancement of the boiling and condensation of refrigerant. The MWCNT/copper composite powder was made by the attrition ball milling, which has been coated on the copper wafer by electrostatic powder coating and sintered with electric furnace. In this paper, experiments were performed to assess the characterization and comparison of CNT before and after sinterning and the morphology changes of the CNT/Cu-coated surface. The samples were examined by the scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDAX) and raman spectroscopy. To verify the heat transfer enhancement, boiling heat transfer tests were performed.

Pretreatment with Trichoderma sp. AH promotes directional conversion of organic nitrogen compounds in supercritical methanolysis of wheat straw

Quan-Xi Zheng,Chuan-Yong Yan,Mu-Wei Zhu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

The specificity and conversion of supercritical methanolysis of wheat straw (WS) and rice straw (RS) canbe enhanced by Pretreatment using Trichoderma sp. AH, particularly the esters of the methanol-solubleportion (MSP) of WS and RS in supercritical methanolysis. However, only about 100 organic compoundsof lower volatility and polarity could be detected in MSP by gas chromatography-mass spectrometry. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry was used to determinethe organic nitrogen compounds (ONCs) in the MSPs from supercritical methanolysis of raw andpretreated WS with Trichoderma sp. AH. The most prevalent ONCs in the MSPs of native and pretreatedWSs in the positive ion mode would be N2On (n = 1–9) species having twin-bonding equivalence values(2–25) together with carbon-atom numbers of 4–35. Peak prevalent ONC within prior-treated WS MSPs isN2O4, with the most abundant ONC in raw WS MSPs is N2O5. These results help to understand the impactof Trichoderma sp. AH pretreatment upon converting ability/specificity for ONCs within WS methanolysisand employing MSP in producing jet fuel.

조선족 문화변동과 문화정체성

鄭喜淑(ZHENG XI SHU) 한국외국어대학교 역사문화연구소 2010 역사문화연구 Vol.35 No.-

“우리는 누구인가?”라는 조선족 민족 정체성에 관한 질문에 대해 필자는 그 답을 문화변동이론으로 접근하여 해석하려 한다. 다시 말해, 조선족 문화변동에 따른 조선족의 황무지개간, 벼농사 등 농경문화의 적응, 조선족의 언어, 문학, 음악, 무용, 조선족의 의식주, 의례와 놀이문화사례 등의 관찰을 통해 조선족문화가 한국이나 조선의 문화도 중국의 문화도 아닌 조선족 그 자체 문화임을 설명하고자 한다. 필자는 조선족사회에서 이슈로 떠오르고 있는 “조선족문화”설을 <일본조선족문화 심포지엄>에서 경험한 바 있는데, 이를 바탕으로 조선족문화에 대한 이해가 사회에서 수행하는 기능을 서술하고, 조선족의 ‘사과배’ 문화와 조선족 언어문화에 대한 규범화에 따른 사례로 ‘조선족문화’란 바로 “조선족 그 자체 문화”라는 황유복의 이론을 확인했다. 나아가 조선족문화도 21세기에 맞는 정체성 확립을 위해서는 지속가능한 새로운 문화를 창출하여야 하며, 그 발전 대책으로 디지털문화콘텐츠산업의 육성을 제안한다. To the question—“Who are we?”—about Chinese Korean national identity, this essay tries to find out the answer through theory of culture change. That is, the present writer explains that ethnic Korean culture in China is the Chinese Korean culture itself, neither Korean nor Chinese culture, by observing and analyzing ethnic Korean cultural cases such as cultivation, rice farming, language, arts, the necessities of life, rituals, pastime culture and so on. Remembering the experience of the emerging issue of Chinese Korean culture at a symposium in Japan, the writer describes social function of understanding the Chinese Korean culture and confirms Youfu Huang's opinion that the Chinese Korean culture is “Chinese Korean its own culture” as a model case for standardization of the ethnic Korean “apple-pear” culture and language culture. In order to establish its identity for the 21st century, Chinese Korean culture should create a new sustainable culture; and the writer suggests promotion of the digital cultural contents industry as measures for its development.

Graphene 입자 코팅 표면의 비등 열전달 특성에 대한 연구

정희여(Xi Ru Zheng),애드워드(E.J. Pialago),박찬우(Chan Woo Park) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

In the present study, the effect of graphene coating on boiling heat transfer is being investigated under a pool of saturated R134a. The influence of the coating thickness and the graphene content on the heat transfer was studied. Finally, the boiling performance of a graphene coated surface is compared with that of carbon nanotubes, acid-treated grapheme, diamond, copper coated surface.