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.

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>

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.

전기분해장치를 이용한 선박평형수관리장치의 배출수에 대한 해양생태독성 및 해양환경위해성에 관한 연구

손명백(M.-B. Shon),손민호(M.H. Son),이지현(J. Lee),손영준(Y.-J. Son),문창호(C.H. Moon),임수연(S.-Y. Im),김영수(Y.-S. Kim) 한국해양환경·에너지학회 2012 한국해양환경·에너지학회 학술대회논문집 Vol.2012 No.11

전기분해장치를 사용하여 선박의 평형수를 처리하는 AquaStar™ BWMS가 개발되었고, 이로부터 방류되는 배출수가 해양생태계에 미치는 영향을 파악하기 위하여 Skeletonema costatum, Brachionus plicatilis 및 Paralichtys olivaceus를 이용하여 배출수독성시험과 생성된 화학물질에 대한 환경위해성 평가를 수행하였다. 배출수독성시험결과 가장 민감한 생물은 S. costatum이었고 20 psu 배출수에 노출되었을 때 NOEC 25.00%, LOEC 50.00% 및 72hr-EC??이 69.97%였다. AquaStar™ BWMS에서 생성된 물질은 총 18개로, bromate, 7개의 volatile halogenated organic compounds, 7개의 halogenated acetic acids, 3개의 halogenated acetonitriles 및 chloropicrin이었다. 그러나 MAMPEC을 이용하여 생성된 18개 물질의 PEC 산출결과는 4.58E-04~4.87E+00 ㎍ L?¹였고, PNEC는 0.016~320.00 ㎍ L?¹였다. 18개 화확물질의 PEC/PNEC 비율은 1을 초과하지 않았고, PBT 특성을 보이지 않았다. 따라서 환경위해성평가결과는 AquaStar™ BWMS에 의하여 처리된 해수가 해양생태계에 수용 불가한 영향을 미치지 않을 것임을 시사하였다. In this study, WET (whole effluent toxicity) test with Skeletonema costatum, Brachionus plicatilis and Paralichthys olivaceus, chemical analysis and ERA (environmental risk assessment) were conducted to assess the unacceptable effect on marine ecosystem by emitting the discharge water treated with AquaStar™ BWMS (ballast water management system) using electrolyzer as main treatment equipment. The most sensitive test organism on discharge water treated with AquaStar™ BWMS was S. costatum that gave the NOEC value of 25.00%, LOEC value of 50.00% and 72hr-EC?? value of 69.97% from WET test result for 20 psu treated discharge water. In the chemical analysis results, total number of substances produced by AquaStar™ BWMS was 18 which were bromate, 7 volatile halogenated organic compounds, 7 halogenated acetic acids, 3 halogenated acetonitriles and chloropicrin. Eighteen substances did not consider as persistence and bioaccumulative chemicals. Uncertainty of toxic property of 18 substances was high. However, the PEC/PNEC ratio of 18 substances did not exceed 1. Therefore, ERA for produced substances indicate that the discharge water treated with AquaStar™ BWMS does not pose unacceptable effect on marine life.

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.