Effect of Mesoporous TiO₂ in Facilitated Olefin Transport Membranes Containing Ag Nanoparticles

김상진,정정표,김동준,김종학,Kim, Sang Jin,Jung, Jung Pyu,Kim, Dong Jun,Kim, Jong Hak The Membrane Society of Korea 2015 멤브레인 Vol.25 No.5

용액-확산 메커니즘에 의해 결정되는 기존의 고분자에서와는 달리, 촉진수송은 투과도와 선택도를 동시에 향상시킬 수 있는 기술이다. 본 연구에서는 은 나노입자, 폴리비닐피롤리돈, 7,7,8,8-테트라시야노퀴노디메탄으로 구성된 촉진수송 올레핀 분리막에 있어서, 메조기공 티타늄산화물($m-TiO_2$)에 대한 영향을 연구하였다. 특히 메조기공 티타늄산화물은 폴리비닐클로라이드-g-폴리옥시에틸렌 메타크릴레이트 가지형 공중합체를 템플레이트로 하여 쉽고 대량 생산이 가능한 방법으로 제조하였다. 엑스레이 회절분석에 따르면, 제조된 메조기공 티타늄산화물은 아나타제와 루타일 상의 혼합으로 구성되어 있으며, 결정의 크기가 약 16 nm 정도 되었다. 메조기공 티타늄산화물을 첨가하였을 때, 분리막의 확산도가 증가하여 혼합기체 투과도가 1.6에서 16 GPU로 증가하였고 선택도는 45에서 37로 약간 감소하였다. 메조기공 티타늄산화물이 첨가되지 않은 분리막은 장시간 성능이 유지되었으나, 메조기공 티타늄산화물이 첨가된 분리막의 경우 시간이 지남에 따라 투과도와 선택도가 감소하였다. 이는 티타늄산화물과 은 사이의 화학적 상호작용으로 은 나노입자의 올레핀 운반체로써의 활성을 감소시키기 때문으로 사료된다. Facilitated transport is considered to be a possible solution to simultaneously improve permeability and selectivity, which is challenging in normal polymeric membranes based on solution-diffusion transport only. We investigated the effect of adding mesoporous $TiO_2$ ($m-TiO_2$) upon the separation performance of facilitated olefin transport membranes comprising poly(vinyl pyrrolidone), Ag nanoparticles, and 7,7,8,8-tetracyanoquinodimethane as the polymer matrix, olefin carrier, and electron acceptor, respectively. In particular, $m-TiO_2$ was prepared by means of a facile, mass-producible method using poly(vinyl chloride)-g-poly(oxyethylene methacrylate) graft copolymer as the template. The crystal phase of $m-TiO_2$ consisted of an anatase/rutile mixture, of crystallite size approximately 16 nm as determined by X-ray diffraction. The introduction of $m-TiO_2$ increased the membrane diffusivity, thereby increasing the mixed-gas permeance from 1.6 to 16.0 GPU ($1GPU=10^{-6}cm^3$(STP)/($s{\times}cm^2{\times}cmHg$), and slightly decreased the propylene/propane selectivity from 45 to 37. However, both the mixed-gas permeance and selectivity of the membrane containing $m-TiO_2$ rapidly decreased over time, whereas the membrane without $m-TiO_2$ had more stable long-term performance. This difference might be attributed to specific chemical interactions between $TiO_2$ and Ag nanoparticles, causing Ag to lose activity as an olefin carrier.

흰쥐에서 ATP 결핍에 의한 혈중 Mg²⁺ 농도조절

김상진,백성수,심소연,오성숙,김진상,Kim, Shang-jin,Baek, Sung-soo,Shim, So-yeon,Oh, Sung-suck,Kim, Jin-shang 대한수의학회 2000 大韓獸醫學會誌 Vol.40 No.2

Since intracellular free $Mg^{2+}$ ($[Mg^{2+}]_i$) appears to be tightly regulated following cellular energy depletion, we hypothesized that the increase in $[Mg^{2+}]_i$ would result in $Mg^{2+}$ extrusion into circulation. Extracellualr $Mg^{2+}$ contents ($[Mg^{2+}]_o$) were measured in rat erythrocytes, the perfused heart and liver, and plasma in the anesthetized rat. Animals were injected intraperitoneally with sodium nitrite ($NaNO_2$) and plasma $Mg^{2+}$ was measured after the injection and then 10 and 20 minutes later. An increase in circulating (plasma) $Mg^{2+}$ ($[Mg^{2+}]_c$) and methemoglobin was observed in animals injected with $NaNO_2$ (30 mg/Kg). The time course of the effects demonstrated that $[Mg^{2+}]_c$ and methemoglobin continued to increase 10 minutes after the $NaNO_2$ injection. Under these conditions, there was a sustained increase in $[Mg^{2+}]_c$, but not in methemoglobin, which was inhibited by pretreatment with potassium cyanide (KCN, 4 mg/Kg), indicating that an increase in $[Mg^{2+}]_c$ was accompanied by ATP depletion. Injection of rotenone (0.9 mg/Kg) or 2,4-dinitrophenol (15 mg/Kg) also induced an increase in $[Mg^{2+}]_c$. Reduced respiration rate from 100/min to 10/min during 30 minutes also caused a time-dependent rise in $[Mg^{2+}]_c$. These increase in $[Mg^{2+}]_c$ were inhibited by pretreatment with KCN. In addition, ATP depletion by $NaNO_2$ or KCN sustainedly increased the $[Mg^{2+}]_o$ in rat erythrocytes. $Mg^{2+}$ efflux was stimulated by KCN in the perfused heart and liver, but not by $NaNO_2$. These results suggest that the activation of $Mg^{2+}$ effluxes into the circulation is directly dependent on the ATP depletion-induced increase in $[Mg^{2+}]_i$ and heart, liver and erythrocytes have a major pool of $Mg^{2+}$ that can be mobilized upon cellular energy state.

재발된 간헐외사시로 재수술한 환자의 임상분석

김상진,최동규,Sang Jin Kim,Dong Gyu Choi 대한안과학회 2007 대한안과학회지 Vol.48 No.2

Purpose: To analyze the clinical course and relationships between the factors and surgical outcomes after reoperation for recurrent intermittent exotropia. Methods: Surgical results were retrospectively investigated in 38 patients who had undergone reoperation at least 3 months after surgical correction. Recurrence was defined as an exodeviation of more than 10 prism diopters at the primary position. We investigated the recurrence rate according to the follow-up duration with survival analysis, and analyzed the relationships between the factors and surgical outcome. Results: The mean survival period was 22.7±20.2 months (range, 3 to 72 months). As the follow-up duration increased, the recurrence rate progressively increased. The hazard ratio for recurrence of a unilateral medial rectus resection as a reoperation was significantly higher than that for a unilateral lateral rectus recession and medial rectus resection (recession and resection)(p=0.021). After using unilateral recession and resection as the primary surgery, the hazard ratio for recurrence of unilateral recession and resection as a reoperation was not significantly different from that for unilateral lateral rectus recession (p=0.480). After a bilateral lateral rectus recession, the hazard ratio for recurrence of unilateral medial rectus resection was not significantly different from that for bilateral medial rectus resection (p=0.076). Conclusions: The surgical options for recurrent intermittent exotropia are contralateral recession and resection or contralateral lateral rectus recession. The procedure chosen depends on the operator`s preference after performing unilateral recession and resection as the primary surgery. After a bilateral lateral rectus recession, the hazard ratio for recurrence of unilateral medial rectus resection was not significantly higher than that for a bilateral medial rectus resection, but even so, a bilateral medial rectus resection may be more effective than unilateral medial rectus resection for recurrent intermittent exotropia.

흰쥐 대동맥 수축에 대한 xylamine의 억제효과

김상진,강형섭,김진상,Kim, Sang-Jin,Kang, Hyung-sub,Kim, Jin-shang 대한수의학회 2004 大韓獸醫學會誌 Vol.44 No.3

The therapeutic efficacy of xylamine in the field of psychological medicine has been recognized for years and the drug is used to treat depression and some other conditions, but little is known about its mechanism of action on vascular system. Therefore, the present study was designed to investigate the influence of xylamine on the contractile responses of isolated rat thoracic arteries to phenylephrine(PE) and potassium chloride(KCl). Xylamine produced a concentration-dependent relaxation in PE-precontracted endothelium intact(+E) rat aortic rings, but not in a KCl-precontracted aortic rings. Also, xylamine inhibited the PE-induced contraction in concentration-dependent manner, but not in the high KCl-induced contraction in +E rings. This concentration-dependent inhibition was suppressed by the removal of the endothelium (-E). The inhibitory effects of xylamine($0.3{\mu}M$) on the PE-induced contractions were suppressed by N(G)-nitro-L-arginine(L-NNA), N(omega)-nitro-L-arginine methyl ester(L-NAME), aminoguanidine, dexamethasone, methylene blue, 1H-[1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one(ODQ), indomethacin, ryanodine, tetrabutylammonium(TBA), lidocaine, procaine and 0 mM extracellular $Na^+$, but not by 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate(NCDC), lithium, nifedipine, verapamil, 0 mM extracellular $Ca^{2+}$, glibenclamide and clotrimazole. These findings suggest that xylamine could act as a vasorelaxant and direct inhibitor of arterial contraction. This vasorelaxation involves an endothelial nitric oxide (NO)/cGMP (guanosine 3',5'-cyclic monophosphate) pathway or cyclooxygenase system, and an interference with $Ca^{2+}$ release, TBA-sensitive $Ca^{2+}$-activated $K^+$ channels and $Na^+$$ channels.

흰쥐 대동맥에서 phospholipase C를 경유한 melatonin의 혈관 이완 작용

김상진,백성수,강형섭,김진상,Kim, Shang-Jin,Baek, Sung-Soo,Kang, Hyung-Sub,Kim, Jin-Shang 대한수의학회 2005 大韓獸醫學會誌 Vol.45 No.4

Melatonin, the principal hormone of the vertebral pineal gland, participates in the regulation of cardiovascular system in vitro and in vivo. However, the effects of melatonin on vascular tissues are still vague. The aim of this study was to assess the relationship between phospholipase C (PLC) and nitric oxide synthase (NOS)/cyclic guanosine 3',5'-monophosphate (cGMP) signaling cascade in the relaxatory action of melatonin in isolated rat aorta. Melatonin induced a concentration-dependent relaxation in phenylephrine (PE)- and KCl-precontracted endothelium intact (+E) aortic rings. In KCl-precontracted +E aortic rings, the melatonin-induced vasorelaxation was not inhibited by endothelium removal or by pretreatment with NOS inhibitors, L-$N^G$-nitor-arginine (L-NNA) and L-$N^G$-nitor-arginine methyl ester (L-NAME), guanylate cyclase (GC) inhibitors, methylene blue (MB) and 1H-[1,2,4] oxadiazolo-[4,3-a] quinoxalin-1-one (ODQ). In PE-precontracted +E aortic rings, the melatonin-induced vasorelaxation was inhibited by endothelium removal or by pretreatment with L-NNA, L-NAME, MB, ODQ and 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC). Moreover, in without endothelium (-E) aortic rings and in the presence of L-NNA, L-NAME, MB and ODQ in +E aortic rings, the melatonin-induced residual relaxations and residual contractile responses to PE were not affected by NCDC, a PLC inhibitor. It is concluded that melatonin can evoke vasorelaxation due to inhibition of PLC pathway through the protein kinase G activation of endothelial NOS/cGMP signaling cascade.

산소유발망막병증 쥐 모델에서 커큐민의 효과

김상진,구용리,김영주,유형곤,Sang Jin Kim,MD,Young Ri Gu,Young Joo Kim,Hyeong Gon Yu,MD,PhD 대한안과학회 2013 대한안과학회지 Vol.54 No.10

Purpose: To investigate the effect of curcumin, known to inhibit hypoxia-inducible factor-1, on retinal neovascularization in a mouse model of oxygen-induced retinopathy (OIR). Methods: OIR was induced by exposing C57BL/6 mice on postnatal day 7 (P7) to 75% hyperoxia for 5 days, followed by 5 days in a room with normal oxygen level. Curcumin was administered intraperitoneally once a day for 5 days from P12 or intravitreally once on P13. Mice retinas on P17 were analyzed for retinal neovascularization, which was compared between curcumin-treated and control mice. Results: After intraperitoneal and intravitreal administration of curcumin, qualitative assessment of retinal neovascularization of flat-mounted retina showed no significant difference compared to control retinas. Quantitative assessment of retinal neovascularization also showed no significant difference between curcumin-treated and control mice. Conclusions: Both intraperitoneal and intravitreal administration of curcumin did not reduce retinal neovascularization in an OIR mouse model. Further investigation including development of new formulations is required for the use of curcumin as an anti-angiogenic agent for retinal neovascularization.

흰쥐에서 혈관내피 의존적인 혈관이완과 혈압하강에 대한 propofol의 억제 효과

김상진,김정곤,조성건,강형섭,김진상,Kim, Shang-Jin,Kim, Jeong-gon,Joe, Sung-gun,Kang, Hyung-sub,Kim, Jin-shang 대한수의학회 2004 大韓獸醫學會誌 Vol.44 No.3

We studied the effect of propofol (PPF) on the endothelium-dependent vascular responses in isolated rat thoracic aorta. In aortic rings with endothelium, PPF inhibited the phenylephrine (PE)-induced contraction in a concentration-dependent manner. In PE-precontracted preparations, PPF attenuated the endothelium-dependent relaxation by acetylcholine but not by A23187. And PPF did not attenuate the endothelium-independent relaxation by sodium nitroprusside (SNP). The relaxation induced by acetylcholine in PE-precontracted aortic rings was significantly augmented by zaprinast, a cGMP-specific phosphodiesterase inhibitor, and this augmentation was inhibited by PPF. Although SNP-induced relaxation was significantly augmented by zaprinast, this augmentation was not inhibited by PPF. In preparations preconstricted with PE, the PPF-induced relaxation was inhibited by atropine. In addition, PPF attenuated the vasorelaxation by phosphodiesterase inhibitors (IBMX, Ro20-1724 or zaprinast except milrinone). In vivo, the infusion of acetylcholine and SNP showed decreased arterial blood pressure in rats. The pre-injection of PPF inhibited the acetylcholine-induced blood pressure lowering, but not the SNP-induced blood pressure lowering. These results suggest that PPF can attenuate in part the acetylcholine-induced vasorelaxation and blood pressure lowering through the inhibition of the acetylcholine receptor-mediated endothelium-derived relaxing factor by acting on endothelium. It is considered that the inhibitory effect of PPF on the vasorelaxation is due to the decreased level of cGMP which can be attributed to the inhibition of the muscarinic receptor and/or receptor-G-protein interaction.

능동형 센서의 깊이 정보를 이용한 3D 객체 생성

김상진,유지상,이승현,Kim, Sang-Jin,Yoo, Ji-Sang,Lee, Seung-Hyun 한국컴퓨터산업학회 2006 컴퓨터産業敎育學會論文誌 Vol.7 No.5

본 논문에서는 능동형 센서를 이용하여 실사 객체에 대한 깊이 정보 및 칼라 정보를 획득하고 획득된 데이터를 이용하여 3D 객체를 생성하였다. 길이 정보를 획득하는 방법은 능동형 센서 모듈을 내장한 $Zcam^{TM}$ 카메라를 이용하였다. <중략>세 번째, 세부 파라미터를 조절하여 깊이 정보의 왜곡을 보정하고 보정된 깊이 정보를 이용하여 3D 메쉬 모델을 생성한 후, 서로 인접한 외곽 점들을 연결하여 완전한 객체 메쉬 모델을 만든다. 최종적으로, 완성된 객체 메쉬 모델에 칼라 영상 데이터의 칼라 값을 적용해 매핑 처리를 수행함으로써 3D 객체를 생성하였다. 실험을 통해 능동형 센서가 장착된 카메라로 획득한 데이터만으로 3D 객체를 생성할 수 있다는 가능성을 제시하였으며, 3차원 전용 스캐너를 이용한 것보다 데이터 획득이 간편하고 용이함을 알 수 있었다. In this paper, 3D objects is created from the real scene that is used by an active sensor, which gets depth and RGB information. To get the depth information, this paper uses the $Zcam^{TM}$ camera which has built-in an active sensor module. <중략> Thirdly, calibrate the detailed parameters and create 3D mesh model from the depth information, then connect the neighborhood points for the perfect 3D mesh model. Finally, the value of color image data is applied to the mesh model, then carries out mapping processing to create 3D object. Experimentally, it has shown that creating 3D objects using the data from the camera with active sensors is possible. Also, this method is easier and more useful than the using 3D range scanner.

미국.일본의 심해생명공학 연구동향

김상진,Kim, Sang-Jin 한국미생물학회 2003 微生物과 産業 Vol.29 No.2

대규모 도시화재에 의한 광역 부력유동의 수치해석에 대한 연구

김상진,Kim, Sang-Jin 한국방재학회 2003 한국도시방재학회지 Vol.3 No.2