W(110) 표면에 CO의 흡착

이경희,유위량,한현석,부진효,이순보,곽현태 성균관대학교 기초과학연구소 1998 論文集 Vol.49 No.-

The interaction of CO with W(110) surface was investigated through LEED, TDS, and photoelectron spectroscopy using synchrotron radiation under UHV condition. After CO saturation at RT, two desorption states, called α and β , were observed at about 400 and 1150 K in thermal desorption spectra, respectively. The kinetics of 3-CO followed the first order kinetics, indicating the existence of molecular CO on W(110) surface. This is contrary to the previous results. The O 1s BE(binding energy) of CO adsorbed on W(110) surface at room temperature was 529.9 eV. On the other hand, the O 1s BE of β-CO after heating to 900 K was different from that of oxygen adsorbed W(110) surface, suggesting a different adsorption state. According to the UP valence band spectra, we observed two peaks at near -10.7 eV (4σ) and -7.0 eV (5σ+1π), indicating the molecular adsorption of CO at room temperature. Furthermore we could see the 4σ peak at the various photon energy and elevated temperatures. Comparing the energy separation, Δ(4σ-1π) , between 4σ and 1π UP peaks of chemisorbed CO, we found that an increased separation reflects an decreased C-O bond strength. Therefore on the basis of TDS and photoelectron spectroscopy, we could suggest that β state of CO on W(110) may not be dissociated and has an adsorption geometry of lying-down mode.

Prophylactic Intraoperative Nasolacrimal Duct Intubation in Surgical Treatment of Facial Fractures—Is There a Role?

Teoh Ryan Liang Wei,Fong Pei Yuan,Cai Elijah Zhengyang,Yap Yan Lin,Hing Eileen Chor Hoong,Lee Han Jing,Nallathamby Vigneswaran,Ong Wei Chen,Lim Jane,Sundar Gangadhara,Lim Thiam Chye 대한성형외과학회 2022 Archives of Plastic Surgery Vol.49 No.1

Nasolacrimal duct (NLD) damage is associated in the majority of type II and III naso-orbito-ethmoid (NOE) fractures.1 Our study aims to investigate the efficacy and safety of prophylactic NLD intubation in the setting of facial fractures, by comparing incidence of postoperative epiphora and wound infection. A retrospective matched control study was conducted on all patients with surgically treated facial fractures from 2008 to 2013 (n = 280) (IRB ref number: DSRB 2013/01198). Patients with the following fracture types were included: NOE (n = 16), frontal sinus (n = 2), Le Fort II/III (n = 8), and > 1 type (n = 48). All patients in this study were included with the intention to treat. The study group comprised patients who were intubated, while the control group patients were not intubated. Each group had 37 patients matched for age, gender, fracture type, and injury type. A single oculoplastic surgeon skilled in lacrimal surgery performed the procedure for all intubated patients. Patients with more severe and complex facial fractures were intubated with bicanalicular Crawford stents. Postoperative epiphora and infective complications (both facial wound and dacryocystitis) were assessed at 1, 3, 6, and 12 months. There was no significant difference in incidence of either postoperative epiphora (p = 0.152) or wound infection (p = 0.556) comparing both groups. Reduced incidence of postoperative epiphora in the study group is statistically not significant and does not support the need for prophylactic intubation. If radiographic evidence of NLD disruption or regurgitation seen on syringing on the NLD intraoperatively is present, intubation is safe and efficacious only if performed by an expert.

Prophylactic Intraoperative Nasolacrimal Duct Intubation in Surgical Treatment of Facial Fractures—Is There a Role?

Teoh Ryan Liang Wei,Fong Pei Yuan,Cai Elijah Zhengyang,Yap Yan Lin,Hing Eileen Chor Hoong,Lee Han Jing,Nallathamby Vigneswaran,Ong Wei Chen,Lim Jane,Sundar Gangadhara,Lim Thiam Chye 대한성형외과학회 2022 Archives of Plastic Surgery Vol.49 No.2

Nasolacrimal duct (NLD) damage is associated in the majority of type II and III naso-orbito-ethmoid (NOE) fractures.1 Our study aims to investigate the efficacy and safety of prophylactic NLD intubation in the setting of facial fractures, by comparing incidence of postoperative epiphora and wound infection. A retrospective matched control study was conducted on all patients with surgically treated facial fractures from 2008 to 2013 (n = 280) (IRB ref number: DSRB 2013/01198). Patients with the following fracture types were included: NOE (n = 16), frontal sinus (n = 2), Le Fort II/III (n = 8), and > 1 type (n = 48). All patients in this study were included with the intention to treat. The study group comprised patients who were intubated, while the control group patients were not intubated. Each group had 37 patients matched for age, gender, fracture type, and injury type. A single oculoplastic surgeon skilled in lacrimal surgery performed the procedure for all intubated patients. Patients with more severe and complex facial fractures were intubated with bicanalicular Crawford stents. Postoperative epiphora and infective complications (both facial wound and dacryocystitis) were assessed at 1, 3, 6, and 12 months. There was no significant difference in incidence of either postoperative epiphora (p = 0.152) or wound infection (p = 0.556) comparing both groups. Reduced incidence of postoperative epiphora in the study group is statistically not significant and does not support the need for prophylactic intubation. If radiographic evidence of NLD disruption or regurgitation seen on syringing on the NLD intraoperatively is present, intubation is safe and efficacious only if performed by an expert.

p62 Sequestosome 1/Light Chain 3b Complex Confers Cytoprotection on Lung Epithelial Cells after Hyperoxia

Liang, Xiaoliang,Wei, Shu-Quan,Lee, Seon-Jin,Fung, James K.,Zhang, Meng,Tanaka, Akihiko,Choi, Augustine M. K.,Jin, Yang American Thoracic Society 2013 American journal of respiratory cell and molecular Vol.48 No.4

Reviewing the Applications of Three Countries' Ground Water Flow Modeling Regulatory Guidelines to Nuclear Facilities in Korea

Lee, Chung-Mo,Hamm, Se-Yeong,Hyun, Seung Gyu,Cheong, Jae-Yeol,Wei, Ming Liang Korean Society of Soil and Groundwater Environment 2017 지하수토양환경 Vol.22 No.3

The numerical analysis of groundwater flow is indispensable for predicting problems associated with water resource development, civil works, environmental hazards, and nuclear power plant construction. Korea lacks public regulatory procedures and guidelines for groundwater flow modeling, especially in nuclear facility sites, which makes adequate evaluation difficult. Feasible step-by-step guidelines are also unavailable. Consequently, reports on groundwater flow modeling have low-grade quality and often present controversial opinions. Additionally, without public guidelines, maintaining consistency in reviewing reports and enforcing laws is more challenging. In this study, the guidelines for groundwater flow modeling were reviewed for three countries - the United States (Documenting Groundwater Modeling at Sites Contaminated with Radioactive Substances), Canada (Guidelines for Groundwater Modelling to Assess Impacts of Proposed Natural Resource Development Activities), and Australia (Australian Groundwater Modelling Guidelines), with the aim of developing groundwater flow modeling regulatory guidelines that can be applied to nuclear facilities in Korea, in accordance with the Groundwater Act, Environmental Impact Assessment Act, and the Nuclear Safety Act.

Minced Pulp as Source of Pulpal Mesenchymal Stem Cells with Odontogenic Differentiation Capacity

Liang, Zhangrui,Kawano, Satoshi,Chen, Wei,Sadrkhani, Moein Seyed,Lee, Chaehwan,Kim, Euiseong,Moshaverinia, Alireza,Kim, Reuben H.,Kang, Mo K. Elsevier 2018 JOURNAL OF ENDODONTICS - Vol.44 No.1

<P><B>Abstract</B></P> <P><B>Introduction</B></P> <P>Pulp tissue regeneration is becoming a reality after discovery of mesenchymal stem cells (MSCs) residing in the pulp tissues through various clinical innovations, although MSC transplantation into the pulp space has met with challenges of <I>in vitro</I> cell expansion and cultures. As a way to circumvent the regulatory and technical complexities of <I>in vitro</I> MSC culture, we investigated the use of minced pulp tissues as a source of pulpal MSCs for tissue regeneration.</P> <P><B>Methods</B></P> <P>We characterized the phenotype of cells explanted from minced pulp (MP), namely MP-derived MSCs (MP-MSCs), compared with dental pulp stem cells (DPSCs) established from pulp tissues by enzyme digestion. Phenotypic characterization included replication kinetics, immunophenotyping, and multilineage differentiation. Using the tooth slice model, we assessed odonto/osteogenic differentiation of DPSCs, MP-MSCs, and minced pulp tissues <I>in situ</I>.</P> <P><B>Results</B></P> <P> <I>In vitro</I> replication of MP-MSCs occurred more rapidly during the initial phase of subcultures compared with DPSCs; however, MP-MSCs arrived at senescence at population doubling 47, whereas DPSCs replicated until population doubling 64, indicating shorter replicative lifespan. MP-MSCs also demonstrated stronger odonto/osteogenic differentiation than DPSCs by alkaline phosphatase activity and the protein expression. Both MP-MSCs and DPSCs demonstrated odonto/osteogenic and adipogenic differentiation capacities. Both cell types also showed mineralized tissue formation in the tooth slice model. Seeding minced pulp tissue on poly-L-lactic acid scaffold allowed for migration of MP-MSCs from the tissues and odontogenic differentiation with dentin sialophosphoprotein expression in the tooth slice model.</P> <P><B>Conclusions</B></P> <P>These data indicated that MP may be an alternative source of pulpal MSCs that may allow <I>de novo</I> pulp-dentin regeneration without the need for <I>in vitro</I> culture and expansion.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Revascularization leads to ectopic tissue formation and falls short in <I>bone fide</I> pulp-dentin regeneration. Prior studies show requirement of pulp cell transplantation for pulp tissue regeneration. </LI> <LI> Cells that migrate from the explanted pulp tissues demonstrate distinct replicative and differentiation phenotype from dental pulp stem cell cultures established by enzyme digestion, whereas both cell types exhibit similar surface markers. </LI> <LI> Direct seeding of minced pulp tissue on synthetic scaffold in tooth slice model yielded migrating pulp cells with odontogenic differentiation capacity. </LI> </UL> </P>

Advances in Research on Stem Cell-Based Pulp Regeneration

Lee Hua-Nien,Liang Cheng,Liao Li,Tian Wei-Dong 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.6

Although root canal therapy is the most common and widely used treatment at clinical presentation, there are still some postoperative complications. As cell biology and tissue engineering techniques advance rapidly, the use of biological therapy to regenerate dental pulp has become a new trend; Relevant literatures in recent five years were searched using key words such as “root canal therapy”, “Dental pulp stem cells”, “Dental pulp regeneration”, and “Cell homing” in PubMed, Web of Science, etc; Dental pulp stem cells (DPSCs) have multi-differentiation potential, self-renewal capability, and high proliferative ability. Stem cell-based dental pulp regeneration has emerged as a new research hot spot in clinical therapy. Recently, dental pulp-like structures have been generated by the transplantation of exogenous DPSCs or the induction of homing of endogenous DPSCs. Studies on DPSCs are important and significant for dental pulp regeneration and dental restoration; In this review, the existing clinical treatment methods, dental pulp regeneration, and DPSC research status are revealed, and their application prospects are discussed. The stem cell-based pulp regeneration exerts promising potential in clinical therapy for pulp regeneration.

GreenIoT Architecture for Internet of Things Applications

( Yi-wei Ma ),( Jiann-liang Chen ),( Yung-sheng Lee ),( Hsin-yi Chang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.2

A power-saving mechanism for smartphone devices is developed by analyzing the features of data that are received from Internet of Things (IoT) sensors devices to optimize the data processing policies. In the proposed GreenIoT architecture for power-saving in IoT, the power saving and feedback mechanism are implemented in the IoT middleware. When the GreenIoT application in the power-saving IoT architecture is launched, IoT devices collect the sensor data and send them to the middleware. After the scanning module in the IoT middleware has received the data, the data are analyzed by a feature evaluation module and a threshold analysis module. Based on the analytical results, the policy decision module processes the data in the device or in the cloud computing environment. The feedback mechanism then records the power consumed and, based on the history of these records, dynamically adjusts the threshold value to increase accuracy. Two smart living applications, a biomedical application and a smart building application, are proposed. Comparisons of data processed in the cloud computing environment show that the power-saving mechanism with IoT architecture reduces the power consumed by these applications by 24% and 9.2%.

Dynamic Profiles of Ubiquitination and Autophagy Associated with Paternal Mitochondria Degradation during Mouse Postfertilization Development

Xing-Wei Liang,Yong-Xun Jin,Ga-Young An,Seul-Ki Lee,Jung-Woo Kwon,Xiang-Shun Cui,Nam-Hyung Kim 한국동물번식학회 2012 Reproductive & Developmental Biology(Supplement) Vol.36 No.2s

It is well established that mitochondrial genome is strictly maternally inherited in mammalian, despite the fact that paternal mitochondria enter into oocyte during fertilization. To date, although some mechanisms have been extrapolated to interpret the elimination of paternal mitochondria, the exact mechanism still is unclear. Recent studies suggest that autophagy process and the ubiquitin-mediated degradation pathway may be involved in elimination of paternal mitochondria. However, the dynamic profiles of autophagy and ubiquitination associated with paternal mitochondria degradation have not been determined in mouse model. Through immunostaining with specific antibody LC3 and Ubiquitin and confocal microscopy, we investigated the dynamic profiles of LC3 and Ubiquitin signals in mouse embryos during preimplantation development. In addition, embryos were stained with MitoTracker Red for tracking the degradation process of paternal mitochondria. Our results showed that paternal mitochondria gradually degraded during postfertilization development, and sporadic paternal mitochondria were found at least in 16 cell embryos. LC3 and Ubiquitin signals appeared in the midpiece of sperm at 3 h postfertilization, and they were strictly colocalizated with paternal mitochondria from zygote to 2 cell embryo. Nevertheless, the colocalization became loose at 4 cell embryos, and gradually disappeared beyond 4 cell embryos. Our results confirmed that autophagy process and the ubiquitin-mediated degradation pathway may take part in the postfertilization remove of paternal mitochondria.

Using Chlorophyll Fluorescence and Vegetation Indices to Predict the Timing of Nitrogen Demand in Pentas lanceolata

Chun-Wei Wu,Kuan-Hung Lin,Ming-Chih Lee,Yung-Liang Peng,Ting-Yi Chou,Yu-Sen Chang 한국원예학회 2015 원예과학기술지 Vol.33 No.6

The objective of this study was to predict the timing of nitrogen (N) demand through analyzing chlorophyll fluorescence (ChlF), soil-plant analysis development (SPAD), and normalized difference vegetation index (NDVI), which are positively correlated with foliar N concentration in star cluster (Pentas lanceolata). The plants were grown in potting soil under optimal conditions for 30 d, followed by weekly irrigation with five concentrations (0, 4, 8, 16, and 24 mM) of N for an additional 30 d. These five N application levels corresponded to leaf N concentrations of 2.62, 3.48, 4.00, 4.23, and 4.69%, respectively. We measured 13 morphological and physiological parameters, as well as the responses of these parameters to various N-fertilizer treatments. The general increases in Dickson’s quality index (DQI), above-ground dry weight (DW), total DW, flowering rate, △F/Fm’, and qP in response to t reatment with 0 to 8 mM N were similar to those of SPAD, NDVI, and Fv/Fm. Consistent and s trong correlations (R² = 0.60 to 0.85) were observed between leaf N concentration (%) and SPAD, NDVI, △F/Fm’, and above-ground DW. Validation of leaf S PAD, NDVI, and △F/Fm’ revealed that these vegetation indices are accurate predictors of leaf N concentration that can be used for non-destructive estimation of the proper timing for N-solution irrigation of P. lanceolata. Moreover, irrigation with 8 mM N-fertilizer i s recommended w hen leaf N concentration, SPAD, NVDI, and △F/Fm’ ratios are reduced from their saturation values of 4.00, 50.68, 0.64, and 0.137%, respectively.