Polarity affects the antioxidant and antimicrobial activities of jellyfish (Acromitus hardenbergi) extracts

Khong, Nicholas M.H.,Foo, Su Chern,Yau, Sook Kun,Chan, Kim Wei,Yusoff, Fatimah Md. The Korean Society of Fisheries and Aquatic Scienc 2022 Fisheries and Aquatic Sciences Vol.25 No.4

Jellyfish is an emerging aquaculture species, farmed for Oriental cuisines and nutraceutical ingredients. This study aimed to examine antioxidative and antimicrobial potentials of various fractions of the jellyfish, Acromitus hardenbergi. The bell and oral arms of the jellyfish were sequentially extracted with petroleum ether (PE), dichloromethane (DCM), chloroform (CHCl₃), methanol (MeOH), and water (H₂O) to extract its bioactive in an increasing polarity gradient. Test fractions were assayed for antiradical activities using electron spin resonance spectrometry, β-carotene-linoleate model and Folin-Ciocalteu assay; and antimicrobial activity against 2 Gram-negative bacteria, 4 Gram-positive bacteria and 2 fungal species using the disc diffusion assay. All fractions were also subjected to Fourier Transform Infrared (FTIR) analysis to identify types of functional groups present. It was found that the hydrophilic extracts (H₂O fractions) possessed the most effective radical scavenging activity (p < 0.05) while the lipophilic extracts (PE fractions) the most active antimicrobial activity, especially against Gram-positive bacteria (p < 0.05). Total oxidation substrates content was found to be highest in the PE fractions of jellyfish bell and oral arms (p < 0.05). FTIR data showed that the H₂O and MeOH fractions contains similar functional groups including -OH, -C=O, -N-H and -S=O groups, while the PE, DCM, and CHCl₃ fractions, the -CH₃, -COOH groups. This study showed that A. hardenbergi contains antioxidants and antimicrobials, thereby supporting the traditional claim of the jellyfish as an anti-aging and health-promoting functional food. Bioassay-guided fractionation approach serves as a critical milestone for the strategic screening, purification, and elucidation of therapeutically significant actives from jellyfish.

힘 보조형 전동 휠체어를 위한 구동 의지 제어 시스템 개발

공정식(Khong, Jung-Shik),이보희(Lee, Bo-Hee) 한국산학기술학회 2012 한국산학기술학회논문지 Vol.13 No.3

본 논문은 힘 보조형 휠체어에 있어 사용자의 구동 의지력을 측정하고 이를 통해 사용자의 구동 의지에 따 른 휠체어 구동 제어를 수행할 수 있는 시스템 개발에 관한 논문이다. 최근 고령자의 증가에 따른 다양한 편의 기구 가 증가되고 있으며 이에 따라 휠체어에 대한 관심이 증가되고 있다. 특히 힘 보조형 휠체어의 경우 기존의 전동 휠 체어가 갖고 있는 운동 부족 등의 문제점을 해결할 수 있도록 고안된 휠체어이다. 본 논문에서는 이러한 힘 보조형 휠체어에 있어 사용자의 구동 의지력을 측정할 수 있는 센서를 제안하였고 이를 통해 사용자의 구동 의지력에 따른 휠체어 제어를 수행하였으며 이를 실험을 통해 검증하였다. This paper deals with development of the driving-will control system in power-assisted electric wheelchair. Nowadays, population of elderly people has been increased rapidly, and also an electric wheelchair has been considered as the device for the elderly. Especially, power-assisted electric wheelchair can overcome problems that a conventional electric wheelchair holds, such as lack of movement of wheelchair user. In this paper, we propose the sensors system to measure the driving-will force and perform the control action for a power-assisted electric wheelchair. And motion performance of the proposed system is verified through the experiment.

Avian Influenza outbreak and Control in Vietnam

Viet Khong Nguyen 한국가금학회 2015 한국가금학회 심포지움 Vol.2015 No.5

Arborinane Triterpenoids from <i>Rubia philippinensis</i> Inhibit Proliferation and Migration of Vascular Smooth Muscle Cells Induced by the Platelet-Derived Growth Factor

Quan, Khong Trong,Park, Hyun-Soo,Oh, Joonseok,Park, Hyun Bong,Ferreira, Daneel,Myung, Chang-Seon,Na, MinKyun American Chemical Society and American Society of 2016 Journal of natural products Vol.79 No.10

<P>The abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are associated with cardiovascular diseases and related complications. Such deleterious proliferation and migration events are triggered by cytokines and growth factors, and among them, platelet-derived growth factor (PDGF) is recognized as the most potent inducer. Despite the genus Rubia being researched to identify valuable commercial and medicinal virtues, Rubia philippinensis has rarely been investigated. Nine arborinane-type triterpenoids (1-9) were identified from this underutilized plant species. In particular, 4 was identified as the first arborinane derivative carrying a ketocarbonyl motif at C-19. The presence of the cyclopentanone moiety and the associated configurational assignment were determined by utilizing NOE and coupling constant analysis. These compounds were assessed for their inhibitory potential on PDGF-induced proliferation and the migration of VSMCs. Treatment with 5 mu M compound 5 (62.6 +/- 10.7%) and compound 9 (41.1 +/- 4.7%) impeded PDGF-stimulated proliferation without exerting cytotoxicity. Compound 7 exhibited antimigration activity in a dose-dependent manner (38.5 +/- 3.0% at 10 mu M, 57.6 +/- 3.2% at 30 mu M). These results suggest that the arborinane-type triterpenoids may be a pertinent starting point for the development of cardiovascular drugs capable of preventing the intimal accumulation of VSMCs.</P>

비평탄 지형에서의 경사 인식을 통한 전동 휠체어 제어 알고리즘 개발

공정식(Khong, Jung-Shik) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.9

본 논문은 경사 인식을 통한 비평탄 지형에서의 전동 휠체어 제어 알고리즘에 관한 내용이다. 최근 고령자가 인구가 급격하게 증가되고 있으며, 이에 따라 휠체어 사용 인구 또한 급격하게 증가되고 있다. 하지만 대부분의 휠체어는 사용자의 안전성을 확보할 수 있는 어떠한 장치 없이 사용자가 직접 제어하고 있다. 이로 인해 경사로에서는 중력의 영향으로 인한 차량 제어에 어려움을 겪게 된다. 이에 본 논문에서는 차량이 경사지에서 이동할 경우 평지에서 이동하는 것과 유사한 모션 제어를 수행할 수 있도록 차량 제어 알고리즘을 제안한다. 이때 다른 센서를 적용하지 않고 사용자의 제어 입력에 대비 차량 의 이동 상태를 파악하여 차량이 경사지에 이동하는 과정에서 발생하는 오차를 인식하여 이를 최소화 할 수 있도록 제어기를 구성함으로써 차량이 사용자가 원하는 상태로 제어할 수 있도록 한다. 이러한 경사에 의해 발생하는 오차 및 이에 대한 차량 제어에 대해 시뮬레이션을 통해 이를 검증하였다. This paper evaluated an electric wheelchair control algorithm by slope recognition on uneven terrain. Nowadays, the population using wheelchair has been increasing rapidly due to increases in the elderly population. On the other hand, most wheelchairs are directly controlled by the user without any device capable of securing the safety of the user. This causes difficulties in wheelchair control from the influence of gravity on the slope. This paper proposes a vehicle control algorithm that can move a wheelchair similar to moving on a plane. At that time, sensors are not used to recognize the degree of the slope. All processes were verified by simulation.

Luncheon Symposium : New Update of Antiemetics Therapy

( Justin Khong Wee Chin ) 대한임상종양학회 2008 대한임상종양연구 심포지엄 Vol.2008 No.14

힘 보조형 스마트 휠체어를 위한 차량 제어 알고리즘 구현

공정식(Khong, Jung-Shik) 한국산학기술학회 2011 한국산학기술학회논문지 Vol.12 No.8

본 논문은 힘 보조형 휠체어에 있어 힘 센서 없이 사용자의 구동 의지를 측정하는 방법과 이를 통한 차량 제어 방법을 제시한다. 이를 위해 먼저 모터의 수학적 모델을 이용하여 사용자의 구동 의지력을 추정하는 알고리즘을 도출한다. 이후 도출된 외력을 기반으로 사용자가 원하는 차량 속도 및 방향을 추정한다. 이를 토대로 차량의 이동량 을 결정하고 차량이 이에 따라 구동되도록 알고리즘을 구성하였으며 이를 시뮬레이션을 통해 검증하였다. This paper deals with method to measure the user's driving-will force and to control the power-assisted wheelchair. To solve this problem, we extract the user's driving-will by using the mathematical motor model. And then, we get the linear and angular velocity at the center of the vehicle. Wheel velocities are also measured from center velocity. Finally, power-assisted electric wheelchairs are controlled by these data. Here all processes are verified by simulation.

ANALYSING SENTIMENTS OF ONLINE REVIEWS ON RESTAURANTS IN MALAYSIA USING PREDICTIVE TEXT ANALYTICS

Kok Wei Khong,Fon Sim Ong,Babajide AbuBakr Muritala,Ken Kyid Yeoh 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

This study aims to analyse the overall sentiments of online reviews on restaurants in Malaysia using predictive text analytics. As we know in opinion mining, sentiment analysis is a prominent technique in predictive text mining. It is a technique that categorises opinions in unstructured text format into binary classification (ie. good or bad). The authors attempt to go beyond the binary classification by viewing texts as empirical entities derived using the Term Frequency - Inverse Document Frequency (TF-IDF) weighting algorithm. These empirical entities, based on online reviews of restaurants in Malaysia, are then manifested into hypothetically defined constructs closely reflecting their thematic and semantic nature. The were 4914 customer reviews from restaurants across 20 towns and cities in Malaysia scraped off TripAdvisor.com using web crawler tools. Then a series of analytical tests were carried out. First the online reviews were parsed, filtered and clustered using SAS Text Miner. Then the online reviews underwent the TF-IDF process to identify significant terms and weightages were assigned according to their importance. The TF-IDF process resulted in a series of important nouns and adjectives from the text corpus. Using these weightages of nouns and adjectives, the authors went on to thematise these terms based on their semantic nature to manifest hypothetical constructs. These constructs were based on the Mehrabian–Russell Stimulus Response Model. Subsequently the authors tested the associations among the constructs using variance-based and covariance-based Structural Equation Modelling (SEM). The authors were encouraged by this exploratory methodological approach in formulating predictive text analytics using SEM. Results indicated that sentiments were generally positive towards restaurants and the important terms derived were price, hospitality, location, waiting time, availability of parking and size of food portion.

New Update of Antiemetics

Chin, Justin Khong-wee 대한종양외과학회 2008 대한임상종양학회 학술대회지 Vol.2008 No.3

미세먼지센서 기반 자동 환기시스템의 개발

홍승기(S.KHong),송상원(S.W.Song),이지석(J.S.Lee),강유미(Y.M.Kang),이회문(H.M.Lee),조동욱(D.U.Cho) 한국통신학회 2017 한국통신학회 학술대회논문집 Vol.2017 No.6