Performance and carrier transport analysis of In_0.7Ga_0.3As quantum-well MOSFETs with Al₂O₃/HfO₂ gate stack

Son, S.W.,Park, J.H.,Baek, J.M.,Kim, J.S.,Kim, D.K.,Shin, S.H.,Banerjee, S.K.,Lee, J.H.,Kim, T.W.,Kim, D.H. Pergamon Press ; Elsevier Science Ltd 2016 Solid-State Electronics Vol.123 No.-

In this paper, we have fabricated and characterized In<SUB>0.7</SUB>Ga<SUB>0.3</SUB>As quantum-well (QW) metal-oxide-semiconductor field-effect-transistors (MOSFETs). We have employed the gate dielectric of the Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> (0.6/2nm) bi-layer stack by ALD. The fabricated device with L<SUB>g</SUB>=4μm exhibits a record maximum transconductance (g<SUB>m_max</SUB>) in excess of 520μS/μm at >1μm region, and reasonably good electrostatic integrity, such as SS=110mV/decade and DIBL=43mV/V. Also, we have investigated the gate length scaling behavior in terms of output, transconductance, and transfer characteristics. In particular, our devices feature very uniform values of the electrostatic integrity, such as SS=100-110mV/decade, V<SUB>T</SUB>=-0.25V to -0.2V and DIBL=40-50mV/V, as L<SUB>g</SUB> decreases from 10μm to 4μm. Furthermore, we have explored the impact of source resistance (R<SUB>S</SUB>) onto the device characteristics of the InGaAs QW MOSFETs. In doing so, we have modeled both measured extrinsic transconductance (g<SUB>m_ext</SUB>) and intrinsic transconductance (g<SUB>m_int</SUB>) as a function of L<SUB>g</SUB>.

The Use of Collagen Content as Determined by Spectral Domain Polarization-Sensitive Optical Coherence Tomography to Assess Colon Anastomosis Healing in a Rat Model

Son, K.H.,Jeong, H.-W.,Jung, W.-W.,Kim, H.-S.,Lee, S.K.,Kim, K.T.,Ahn, C.B.,Park, K.Y.,Kim, B.-M.,Lee, S.H. S. Karger AG 2014 European surgical research Vol.52 No.1

<P>Abstract</P><P><B><I>Background/Purpose:</I></B> Many studies have been undertaken to prevent anastomosis leakage of the colon, and several methods have been used to assess anastomosis healing, such as measurement of bursting pressure or hydroxyproline (a marker of collagen) content at the anastomosis site. However, these methods are inappropriate for comparing anastomosis healing at two time points in the same animals. In the present study, we measured the collagen level by spectral domain polarization-sensitive optical coherence tomography (SD-PS-OCT) to assess anastomosis healing. <B><I>Methods:</I></B> Sprague-Dawley rats were divided into groups C (saline-administered controls; study group) and M [a 5-fluorouracil (5-FU)-administered experimental group]. Immediately after end-to-end anastomosis of the colon, SD-PS-OCT images of anastomoses were taken (baseline). Animals were administered saline or 5-FU for 7 days. On the 7th postoperative day, SD-PS-OCT images were acquired, a histopathologic exam was performed, and hydroxyproline levels as well as mRNA expressions of collagen-1 and collagen-3 were measured at the anastomosis site. <B><I>Results:</I></B> Fibroblast proliferation and inflammatory cell infiltration were greater in group C than in group M. The mRNA expressions of collagen-1 and collagen-3 were substantially higher in group C. Hydroxyproline levels were higher in group M than in group C. Though collagen levels measured by SD-PS-OCT at 7 days were elevated compared with baseline in group C, no such changes were observed for group M. <B><I>Conclusion:</I></B> Collagen levels at the colon anastomosis site, measured with SD-PS-OCT, were not increased at 7 days postoperatively versus baseline when 5-FU was injected, but were increased in saline-treated controls. The measurement of collagen content by SD-PS-OCT was found to provide a good means of assessing anastomosis healing, because it allows in situ assessment of collagen contents at baseline and during the postoperative period.</P><P>© 2014 S. Karger AG, Basel</P>

Biochemical, pharmaceutical and therapeutic properties of long-acting lithocholic acid derivatized exendin-4 analogs

Chae, S.Y.,Jin, C.H.,Shin, J.H.,Son, S.,Kim, T.H.,Lee, S.,Youn, Y.S.,Byun, Y.,Lee, M.S.,Lee, K.C. Elsevier Science Publishers 2010 Journal of controlled release Vol.142 No.2

Alterations in the physicochemical characteristics of peptide drugs can transform their biological and pharmaceutical features. In the present study, we explored the potentials of lithocholic acid (LCA)-modified exendin-4 derivatives as novel long-acting GLP-1 receptor agonists. Exendin-4 was modified with lithocholic acid at two lysine residues to produce three derivatives that were obtained by reverse-phase HPLC separation, namely, Lys<SUP>12</SUP>-LCA-exendin-4 (LCA-M2), Lys<SUP>27</SUP>-LCA-exendin-4 (LCA-M1), and Lys<SUP>12,27</SUP>-LCA-exendin-4 (LCA-Di)). The biological, pharmacological, and physicochemical characteristics of these three exendin-4 analogues were then investigated. Although slight reductions in the GLP-1 receptor binding capacity and insulinotropic activity of exendin-4 were observed after derivatization, the mono-LCA substitutions, especially LCA-M1, well-preserved antidiabetic activity in type 2 diabetic mice when administered subcutaneously or intraperitoneally. Furthermore, the pharmacokinetic characteristics were dramatically enhanced, that is, absorption was delayed and elimination half-life was increased (1.6+/-0.4 and 9.7+/-1.4h by exendin-4 and LCA-M1, respectively). The enhanced long-acting characteristics of the derivative was found to be due to albumin binding and nanoparticle formation, and these were verified by the restoration of normoglycemia in type 2 diabetic mice after single injection (>24h, >10nmol/kg, s.c.) and daily injections (15nmol/kg/day) maintained normoglycemia for the 4-week administration period. Furthermore, antidiabetic potentials, such as, glucose clearance kinetics and percentage areas occupied by pancreatic β-cells were also enhanced by long-term LCA-M1 administration. The present study demonstrates that the derivatization of exendin-4 with LCA offers a possible means of producing a long-acting GLP-1 receptor agonist.

放射菌을 利用한 異種間 原形質體 融合과 그 融合體의 安定性에 관한 硏究(Ⅱ)

閔洪基,金昌珉,孫麗源,韓惠勝,崔英珠,丁大映,韓康玄,李相燮,李欽淑,元奉必 국립보건연구원 1992 국립보건원보 Vol.29 No.2

Pinoresinol-4,4'-di-O-β-d-glucoside from Valeriana officinalis root stimulates calcium mobilization and chemotactic migration of mouse embryo fibroblasts

Do, K.H.,Choi, Y.W.,Kim, E.K.,Yun, S.J.,Kim, M.S.,Lee, S.Y.,Ha, J.M.,Kim, J.H.,Kim, C.D.,Son, B.G.,Kang, J.S.,Khan, I.A.,Bae, S.S. G. Fischer 2009 Phytomedicine Vol.16 No.6

Lignans are major constituents of plant extracts and have important pharmacological effects on mammalian cells. Here we showed that pinoresinol-4,4'-di-O-β-d-glucoside (PDG) from Valeriana officinalis induced calcium mobilization and cell migration through the activation of lysophosphatidic acid (LPA) receptor subtypes. Stimulation of mouse embryo fibroblast (MEF) cells with 10μM PDG resulted in strong stimulation of MEF cell migration and the EC<SUB>50</SUB> was about 2μM. Pretreatment with pertussis toxin (PTX), an inhibitor of G<SUB>i</SUB> protein, completely blocked PDG-induced cell migration demonstrating that PDG evokes MEF cell migration through the activation of the G<SUB>i</SUB>-coupled receptor. Furthermore, pretreatment of MEF cells with Ki16425 (10μM), which is a selective antagonist for LPA<SUB>1</SUB> and LPA<SUB>3</SUB> receptors, completely blocked PDG-induced cell migration. Likewise, PDG strongly induced calcium mobilization, which was also blocked by Ki16425 in a dose-dependent manner. Prior occupation of the LPA receptor with LPA itself completely blocked PDG-induced calcium mobilization. Finally, PDG-induced MEF cell migration was attenuated by pretreatment with a phosphatidylinositol 3-kinase (PI3K) inhibitor such as LY294002. Cells lacking downstream mediator of PI3K such as Akt1 and Akt2 (DKO cells) showed loss of PDG-induced migration. Re-expression of Akt1 (but not Akt2) completely restored PDG-induced DKO cell migration. Given these results, we conclude that PDG is a strong inducer of cell migration. We suggest that the pharmacological action of PDG may occur through the activation of an LPA receptor whereby activation of PI3K/Akt signaling pathway mediates PDG-induced MEF cell migration.

Alterations of contractions and L-type Ca²⁺ currents by murrayafoline-A in rat ventricular myocytes

Son, M.J.,Chidipi, B.,Kim, J.C.,Huong, T.T.,Tai, B.H.,Kim, Y.H.,Ahn, J.R.,Cuong, N.M.,Woo, S.H. North-Holland ; Elsevier Science Ltd 2014 european journal of pharmacology Vol.740 No.-

We examined the effects of murrayafoline-A (1-methoxy-3-methylcarbazole, Mu-A), which is isolated from the dried roots of Glycosmis stenocarpa, on cell shortenings and L-type Ca<SUP>2+</SUP> currents (I<SUB>Ca,L</SUB>) in rat ventricular myocytes. Cell shortenings and I<SUB>Ca,L</SUB> were measured using the video edge detection method and patch-clamp techniques, respectively. Mu-A transiently increased cell shortenings in a concentration-dependent manner with an EC<SUB>50</SUB> of ~20μM. The maximal effect of Mu-A, approximately 175% of the control, was observed at ≥100μM. The positive inotropic effect of Mu-A (25μM) reached a maximum after ~2-min exposures, and then decayed after a ~1-min steady-state. During the Mu-A-induced positive inotropy, the rate of contraction was accelerated, whereas the rate of relaxation was not significantly altered. To understand the possible mechanism for the Mu-A-induced positive inotropy, the I<SUB>Ca,L</SUB> was assessed. Mu-A transiently enhanced the I<SUB>Ca,L</SUB>. Concentration-dependence of the increase in I<SUB>Ca,L</SUB> by Mu-A was similar to that of positive inotropic effect of Mu-A. The maximal effect of Mu-A (25μM) on I<SUB>Ca,L</SUB> was observed at 2-3min after the application of Mu-A. A partial inhibition of I<SUB>Ca,L</SUB> using verapamil (1μM) induced a right shift of concentration-response curve of the positive inotropic effect of Mu-A and significantly attenuated the effect. These results suggest that Mu-A may transiently enhance contractility, at least in part, by increasing the Ca<SUP>2+</SUP> influx through the L-type Ca<SUP>2+</SUP> channels in rat ventricular myocytes.

FABRICATION AND ELECTRICAL PROPERTIES OF PZT-PVDF 0-3 TYPE COMPOSITE FILM

Son, Y. H.,Kweon, S. Y.,Kim, S. J.,Kim, Y. M.,Hong, T. W.,Lee, Y. G. Taylor Francis 2007 Integrated ferroelectrics Vol.88 No.1

<P> A film speaker was fabricated with 0-3 type piezoelectric composite. The 0-3 type composite was developed to incorporate the advantages of both ceramic and polymer. The pastes of PZT-PVDF composite were made with various mixing ratio. The paste was printed by conventional screen-printing method on ITO (Indium Tin Oxide) bottom electrode which was deposited on PET (polyethylene terephthalate) polymer film. The prepared composite film was about 80 μm in thickness. After printing the top-electrode of silver-paste, 4 kV/mm of DC field was applied at 120°C for an hour to align the electric dipole in the 0-3 composite film. The piezoelectric charge constant of d33 was increased with increasing the PZT weight percent. The maximum value was 24 pC/N at 70 wt% of PZT. But the piezoelectric voltage constant of g33 had the maximum value about 32 mV · m/N at 65 wt% of PZT. The SPL (Sound Pressure Level) of the speaker fabricated with the 65:35 composite film was tested at various driving voltages of 1 ∼ 100Vrms. The SPL was saturated at the driving voltage of 70Vrms and the value was about 68 dB at 1 kHz.</P>

Long-channel In_0.7Ga_0.3As/In_0.52Al_0.48As quantum-well MOSFETs on InP substrate with record <i>μ_{n_eff}</i> = 6960 cm²/V-s

Son, S.-W.,Shin, S.H.,Park, J.H.,Baek, J.-M.,Kim, D.-K.,Lee, J.-H.,Kim, T.-W.,Kim, D.-H. IET 2017 Electronics letters Vol.53 No.18

<P>Long-channel In0.7Ga0.3As/In0.52Al0.48As quantum-well (QW) metaloxide- semiconductor field-effect-transistors (MOSFETs) on InP substrate have been fabricated and characterised. The fabricated device with L-g = 4 mu m exhibits excellent maximum transconductance (g(m_ max)) in excess of 0.48 mS/mu m at V-DS = 0.95 V, together with reasonably good electrostatic integrity of drain-induced-barrier-lowering < 40 mV/V and subthreshold-swing < 100 mV/decade. Besides, the effective mobility (mu(n_eff)) of the same device has been extracted, revealing that the device in this work yields excellent mu(n_eff) = 6960 cm(2)/V-s at room temperature. To the knowledge of the authors, the value of mu(n_eff) in this work is the highest in any surface-channel InGaAs MOSFET technology.</P>

박막자기헤드의 집적공정 기술개발에 관한 연구

이석윤,허명수,손동수,황병철,조동율,천희곤,오태희,송병무,송한식,이우형,이광철,김오규,권영규,구경완 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

The thin film growing processes and the photolithographic techniques involved in the manufacturing of thin film magnetic heads are discussed. The thin film heads are composed of the hundreds of electromagnetic transducers on a single wafer and are made of Al_(2)O_(3)-TiC substrate on which Al_(2)O_(3) film as a insulating, protective layer and gap material, Cu film as a multi-turn coil and permalloy film as a magnetic material are deposited and patterned. In this article we will introduce how the thin film heads is fabricated and differ from an integrated semiconductor device. An effort is devoted to develop the formation of PR frame using a lithography process and finally the thin film heads manufacturing technologies.

간호대생과 비보건계열 여대생의 미세먼지 위험에 대한 인식과 지식, 건강 관리행위 비교 연구

김선미,김슬기,김진선,박주형,배다희,유수빈,유영주,임지향,최유진,Chen Mengyao,양숙자,손지희 이화여자대학교 간호과학대학 2019 이화간호학회지 Vol.- No.53

Purpose: This study aimed to know whether there is a comparison of perception, knowledge and health promoting behaviors about particular matter between nursing students and non-health departments college students. Methods: A quantitative research is used. Data were collected from August 1 to 19. The study sample was nursing students and non-health departments students. For the similar condition of samples, this study excluded whose first language is not Korean. Independent T-test and pearson’s correlation was used for this study. Results: A significant positive correlation did not existed between difference of major and perception(t=0.017, p=0.986), knwledge(t=0.652, p=.516) and health promoting behaviors(t=-0.114, p=.910) about particular matters. Conclusion: Based on the study results, there is no significant correlation of perception and actions about particular matters between nursing students and non-health department college students.