The effect of IDS (immediate dentin sealing) on dentin bond strength under various thermocycling periods

Lee, sungbok Richard,Lee, Sang-Min,Park, Su-Jung,Lee, Suk-Won,Lee, Do Yun,Im, Byung-Jin,Ahn, Su-Jin The Korean Academy of Prosthodonitics 2015 The Journal of Advanced Prosthodontics Vol.7 No.3

PURPOSE. The purpose of this study was to find out the effect of immediate dentin sealing (IDS) on bond strength of ceramic restoration under various thermocycling periods with DBA (dentin bonding agent system). MATERIALS AND METHODS. Fifty freshly extracted human mandibular third molars were divided into 5 groups (1 control and 4 experimental groups) of 10 teeth. We removed enamel layer of sound teeth and embedded them which will proceed to be IDS, using All Bond II. A thermocycling was applied to experimental groups for 1, 2, 7, 14 days respectively and was not applied to control group. IPS Empress II for ceramic was acid-etched with ceramic etchant (9.5% HF) and silane was applied. Each ceramic disc was bonded to specimens with Duo-link, dual curable resin cement by means of light curing for 100 seconds. After the cementation procedures, shear bond strength measurement and SEM analysis of the fractured surface were done. The data were analyzed with a one-way ANOVA and Tukey multiple comparison test (${\alpha}$=.05). RESULTS. There were no statistically significant differences between 4 experimental groups and control group, however the mean value started to decrease in group 7d, and group 14d showed the lowest mean bond strength in all groups. Also, group 7d and 14d showed distinct exposed dentin and collapsed hybrid layer was observed in SEM analysis. CONCLUSION. In the present study, it can be concluded that ceramic restorations like a laminate veneer restoration should be bonded using resin cement within one week after IDS procedure.

The Effect of Fibronectin-Immobilized Microgrooved Titanium Substrata on Cell Proliferation and Expression of Genes and Proteins in Human Gingival Fibroblasts

Kim, Eun-Cheol,Lee, Do Yun,Lee, Myung-Hyun,Lee, Hong Jae,Kim, Kyung-Hee,Leesungbok, Richard,Ahn, Su-Jin,Park, Su-Jung,Yoon, Joon-Ho,Jee, Yu-Jin,Lee, Sang Cheon,Lee, Suk Won Springer-Verlag 2018 조직공학과 재생의학 Vol.15 No.5

Tunneling decay of self-gravitating vortices

Dupuis, É,ric,Gobeil, Yan,Lee, Bum-Hoon,Lee, Wonwoo,MacKenzie, Richard,Paranjape, Manu B.,Yajnik, Urjit A.,Yeom, Dong-han,Gwak, B.,Kang, G.,Kim, C.,Kim, H.-C.,Lee, C.-H.,Lee, J.,Lee, S.,Lee, W. EDP Sciences 2018 The European Physical Journal Conferences Vol.168 No.-

<P>We investigate tunneling decay of false vortices in the presence of gravity, in which vortices are trapped in the false vacuum of a theory of scalar electrodynamics in three dimensions. The core of the vortex contains magnetic flux in the true vacuum, while outside the vortex is the appropriate topologically nontrivial false vacuum. We numerically obtain vortex solutions which are classically stable; however, they could decay via tunneling. To show this phenomenon, we construct the proper junction conditions in curved spacetime. We find that the tunneling exponent for the vortices is half that for Coleman-de Luccia bubbles and discuss possible future applications.</P>

Single-molecule views of MutS on mismatched DNA

Lee, Jong-Bong,Cho, Won-Ki,Park, Jonghyun,Jeon, Yongmoon,Kim, Daehyung,Lee, Seung Hwan,Fishel, Richard Elsevier 2014 DNA repair Vol.20 No.-

<P><B>Abstract</B></P> <P>Base-pair mismatches that occur during DNA replication or recombination can reduce genetic stability or conversely increase genetic diversity. The genetics and biophysical mechanism of mismatch repair (MMR) has been extensively studied since its discovery nearly 50 years ago. MMR is a strand-specific excision-resynthesis reaction that is initiated by MutS homolog (MSH) binding to the mismatched nucleotides. The MSH mismatch-binding signal is then transmitted to the immediate downstream MutL homolog (MLH/PMS) MMR components and ultimately to a distant strand scission site where excision begins. The mechanism of signal transmission has been controversial for decades. We have utilized single molecule Forster Resonance Energy Transfer (smFRET), Fluorescence Tracking (smFT) and Polarization Total Internal Reflection Fluorescence (smP-TIRF) to examine the interactions and dynamic behaviors of single <I>Thermus aquaticus</I> MutS (TaqMutS) particles on mismatched DNA. We determined that TaqMutS forms an incipient clamp to search for a mismatch in ∼1s intervals by 1-dimensional (1D) thermal fluctuation-driven rotational diffusion while in continuous contact with the helical duplex DNA. When MutS encounters a mismatch it lingers for ∼3s to exchange bound ADP for ATP (ADP→ATP exchange). ATP binding by TaqMutS induces an extremely stable clamp conformation (∼10min) that slides off the mismatch and moves along the adjacent duplex DNA driven simply by 1D thermal diffusion. The ATP-bound sliding clamps rotate freely while in discontinuous contact with the DNA. The visualization of a train of MSH proteins suggests that dissociation of ATP-bound sliding clamps from the mismatch permits multiple mismatch-dependent loading events. These direct observations have provided critical clues into understanding the molecular mechanism of MSH proteins during MMR.</P>

Screening for<i>Escherichia coli</i>K-12 genes conferring glyoxal resistance or sensitivity by transposon insertions

Lee, Changhan,Kim, Jihong,Kwon, Minsuk,Lee, Kihyun,Min, Haeyoung,Kim, Seong Hun,Kim, Dongkyu,Lee, Nayoung,Kim, Jiyeun,Kim, Doyun,Ko, Changmin,Park, Chankyu,Calendar, Richard Published by Elsevier/North Holland on behalf of t 2016 FEMS microbiology letters Vol.363 No.18

CURRENT GLOBAL STATUS OF LABORATORY ANIMALS

Richard C.S. Lee 건국대학교 동물자원연구센터 1993 국제 심포지움 Vol.- No.4

실험동물학은 급속히 변화하면서 성장하는 생명과학영역의 한 분야이다. 또한 생물의학 사회에 그 중요성이 부각되면서 우리 모두가 의식하고 적극적으로 참여하여 보다 훌륭한 과학과 보다 나은 상식으로써 그것을 개선해 나아가는 데에 많은 새 문제점들이 나타난다. 국제적인 회사인 찰스리버 연구소는 위의 사실을 잘 인식하고 인류의 궁극적인 복리를 위해 우리 직원 및 고객과 긴밀히 협력하여 연구용 동물 및 관련제품과 서비스를 제공함에 있어 세계의 리더로서 그 우수성을 인정받고자 노력해 왔다. 최근에 우리가 상기한 언명을 이루기 위해 부단히 애써온 방법을 첨언하면 다음과 같다. 1. 남북미, 유럽, 아시아 등 13개국의 생산시설과 서비스점을 갖는 진정한 세계적인 기업이 됨으로써 2. 국제적인 평준화추세에 필수불가결한 국제규격에 정말 합당한 고품질의 실험동물을 공급하는 최고의 회사가 됨으로써 3. 동물연구분야의 정보교환을 위한 국제센타로서 활동함으로써 4. 보다 우수한 품질의 연구용 동물과 서비스를 제공하여 보다 우수한 과학의 주요한 추진자가 됨으로써, 이것은 중국, 한국, 동유럽 및 남미와 같은 여러국가에서도 마찬가지이다. In summary, the laboratory animal science field is growing but rapidly changing in the life sciences sector. Its rising importance to the biomedical research community also raises many new issues that all of us should be aware of and proactively work on to improve them through better sciences and better common senses. As an international company, Charles River Laboratories well recognizes the above facts and has committed ourselves to meet researcher's needs and be recognized for excellence as the world leader in providing research animals and related products and services in close partnership with our employees and customers for the ultimate benefits of mankind. Currently, we have worked hard towards the above commitment by: 1. Becoming a truely global corporation with production facilities and service offices in 13 countries in North/South Americas, Europe and Asia; 2. By being a prime source for high quality laboratory animals that truly meet international standards which are also vital to the international harmonization trend; 3. By acting as an international center for informational exchange in the animal research field; and 4. By becoming one of the key promoters of better sciences by providing better quality research animal and services, including in newcomer countries such as China, Korea, Eastern Europe and South America.

Disruption of<i>Nfic</i>Causes Dissociation of Odontoblasts by Interfering With the Formation of Intercellular Junctions and Aberrant Odontoblast Differentiation

Lee, Tae-Yeon,Lee, Dong-Seol,Kim, Hyun-Man,Ko, Jea Seung,Gronostajski, Richard M.,Cho, Moon-Il,Son, Ho-Hyun,Park, Joo-Cheol SAGE Publications 2009 The Journal of histochemistry and cytochemistry Vol.57 No.5

<P>We reported previously that Nfic-deficient mice exhibit short and abnormal molar roots and severely deformed incisors. The objective of this study is to address the mechanisms responsible for these changes using morphological, IHC, and RT-PCR analysis. Nfic-deficient mice exhibited aberrant odontoblasts and abnormal dentin formation in molar roots and the labial crown analog of incisors. The most striking changes observed in these aberrant odontoblasts were the loss of intercellular junctions and the decreased expression of ZO-1 and occludin. As a result, they became dissociated, had a round shape, and lost their cellular polarity and arrangement as a sheet of cells. Furthermore, the dissociated odontoblasts became trapped in dentin-like mineralized tissue, resembling osteodentin in the overall morphology. These findings suggest that loss of the Nfic gene interferes with the formation of intercellular junctions that causes aberrant odontoblast differentiation and abnormal dentin formation. Collectively, these changes in odontoblasts contributed to development of molars with short and abnormal roots in Nfic-deficient mice.</P>

Regulation of Hepatic Gluconeogenesis by an ER-Bound Transcription Factor, CREBH

Lee, Min-Woo,Chanda, Dipanjan,Yang, Jianqi,Oh, Hyunhee,Kim, Su Sung,Yoon, Young-Sil,Hong, Sungpyo,Park, Keun-Gyu,Lee, In-Kyu,Choi, Cheol Soo,Hanson, Richard W.,Choi, Hueng-Sik,Koo, Seung-Hoi Elsevier 2010 Cell metabolism Vol.11 No.4

<P><B>Summary</B></P><P>Endoplasmic reticulum (ER)-bound transcription factor families are shown to be involved in the control of various metabolic pathways. Here, we report a critical function of ER-bound transcription factor, CREBH, in the regulation of hepatic gluconeogenesis. Expression of CREBH is markedly induced by fasting or in the insulin-resistant state in rodents in a dexamethasone- and PGC-1α-dependent manner, which results in the accumulation of active nuclear form of CREBH (CREBH-N). Overexpression of constitutively active CREBH activates transcription of <I>PEPCK-C</I> or <I>G6Pase</I> by binding to its enhancer site that is distinct from the well-characterized CREB/CRTC2 regulatory sequences in vivo. Of interest, knockdown of CREBH in liver significantly reduces blood glucose levels without altering expression of genes involved in the ER stress signaling cascades in mice. These data suggest a crucial role for CREBH in the regulation of hepatic glucose metabolism in mammals.</P> <P><B>Highlights</B></P><P>► PGC-1α/GR activates CREBH expression under fasting or insulin-resistant conditions ► CREBH enhances hepatic gluconeogenesis via a CRTC2-dependent manner ► Depletion of CREBH in the liver ameliorates fasting hyperglycemia in diabetic mice</P>

Salt Induces Adipogenesis/Lipogenesis and Inflammatory Adipocytokines Secretion in Adipocytes

Lee, Myoungsook,Sorn, Sungbin Richard,Lee, Yunkyoung,Kang, Inhae MDPI 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.1

<P>It is well known that high salt intake is associated with cardiovascular diseases including hypertension. However, the research on the mechanism of obesity due to high salt intake is rare. To evaluate the roles of salt on obesity prevalence, the gene expression of adipogenesis/lipogenesis and adipocytokines secretion according to adipocyte dysfunction were investigated in salt-loading adipocytes. High salt dose-dependently increased the expression of adipogenic/lipogenic genes, such as <I>PPAR-γ, C/EBPα</I>, <I>SREBP1c, ACC, FAS,</I> and <I>aP2</I>, but decreased the gene of lipolysis like <I>AMPK</I>, ultimately resulting in fat accumulation. With SIK-2 and Na<SUP>+</SUP>/K<SUP>+</SUP>-ATPase activation, salt increased the metabolites involved in the renin-angiotensin-aldosterone system (RAAS) such as <I>ADD1, CYP11β2,</I> and <I>MCR.</I> Increasing insulin dependent insulin receptor substrate (IRS)-signaling, resulting in the insulin resistance, mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and Akt-mTOR were activated but AMPK(Thr<SUP>172</SUP>) was depressed in salt-loading adipocytes. The expression of pro-inflammatory adipocytokines, TNFα, MCP-1, COX-2, IL-17A, IL-6, leptin, and leptin to adiponectin ratio (LAR) were dose-dependently increased by salt treatment. Using the inhibitors of MAPK/ERK, U0126, we found that the crosstalk among the signaling pathways of MAPK/ERK, Akt-mTOR, and the inflammatory adipogenesis can be the possible mechanism of salt-linked obesity. The possibilities of whether the defense mechanisms against high dose of intracellular salts provoke signaling for adipocytes differentiation or interact with surrounding tissues through other pathways will be explored in future research.</P>

Growth of Nanosized Single Crystals for Efficient Perovskite Light-Emitting Diodes

Lee, Seungjin,Park, Jong Hyun,Nam, Yun Seok,Lee, Bo Ram,Zhao, Baodan,Di Nuzzo, Daniele,Jung, Eui Dae,Jeon, Hansol,Kim, Ju-Young,Jeong, Hu Young,Friend, Richard H.,Song, Myoung Hoon American Chemical Society 2018 ACS NANO Vol.12 No.4

<P>Organic-inorganic hybrid perovskites are emerging as promising emitting materials due to their narrow full-width at half-maximum emissions, color tunability, and high photoluminescence quantum yields (PLQYs). However, the thermal generation of free charges at room temperature results in a low radiative recombination rate and an excitation-intensity-dependent PLQY, which is associated with the trap density. Here, we report perovskite films composed of uniform nanosized single crystals (average diameter = 31.7 nm) produced by introducing bulky amine ligands and performing the growth at a lower temperature. By effectively controlling the crystal growth, we maximized the radiative bimolecular recombination yield by reducing the trap density and spatially confining the charges. Finally, highly bright and efficient green emissive perovskite light-emitting diodes that do not suffer from electroluminescence blinking were achieved with a luminance of up to 55 400 cd m<SUP>-2</SUP>, current efficiency of 55.2 cd A<SUP>-1</SUP>, and external quantum efficiency of 12.1%.</P> [FIG OMISSION]</BR>