자궁경부암조직에서 Polymerase Chain Reaction, In Situ Hybridization 및 Polymerase Chain Reaction In Situ 기법을 이용한 인형 유두종 바이러스의 검출

김세찬,서순팔,기승정,신명근,변동억,신종희,송정원,박창수,최호선 대한임상병리학회 1997 대한임상병리학회지 Vol.17 No.2

Pore-scale study of in-situ surfactant flooding with strong oil emulsification in sandstone based on X-ray microtomography

Yun She,Chunwei Zhang,Mohammad Azis Mahardika,Anindityo Patmonoaji,Yingxue Hu,Shintaro Matsushita,Tetsuya Suekane 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

This study presented a pore-scale investigation on the dynamic displacement of oil subjected to ex-situand in-situ surfactantflooding using X-ray microtomography. The ex-situ surfactant solution was preprepared,whereas the in-situ surfactant was generated directly with the chemical reaction inside porousmedia. The results showed that oil removal from the pore spaces relied on the combination of piston-like,pore-bodyfilling and a weak emulsification mechanism in the ex-situ system, whereas the in-situ systemwas dominated by a strong emulsification process. The threshold capillary pressure was decreasedsignificantly owing to interfacial tension reduction and wettability alteration, which enhanced the oilcluster mobilization. Therefore, the in-situ system produced the highest oil recovery efficiency of 86.9%compared with ex-situ system and waterflooding. The emulsifying ability was evaluated through oilcluster size distributions and their dynamic evolution. The networks or branches disappeared andemulsified into small oil ganglia and singlets, thereby leading to a significant decrease in the averageequivalent diameter. Finally, strong emulsification in the in-situ system was attributed to quick andprecise surfactant aggregation at the oil–water interface that induced blebbing, whereas the ex-situ casewas dominated by slow surfactant transport relying on advection and diffusion in theflow mainstream.

Catechol-rich gelatin hydrogels <i>in situ</i> hybridizations with silver nanoparticle for enhanced antibacterial activity

Le Thi, Phuong,Lee, Yunki,Hoang Thi, Thai Thanh,Park, Kyung Min,Park, Ki Dong Elsevier 2018 Materials science & engineering. C, Materials for Vol.92 No.-

<P><B>Abstract</B></P> <P>Recently, the interest in antimicrobial hydrogels with impregnated antibacterial agents has significantly increased because of their ability to combat infection in biomedical applications, including wound management, tissue engineering, and biomaterial surface coating. Among these antibacterial reagents, silver nanoparticles (AgNP) show good antibacterial activity against both gram-negative and gram-positive bacteria, including highly multi-resistant strains. However, the entrapment of AgNP within a hydrogel matrix is often associated with toxicity issues because of the use of chemical reductants (<I>e.g.</I>, commonly sodium borohydride), burst leaching, or unwanted agglomeration of AgNP in the absence of surfactants or stabilizers. In this study, we present catechol-rich gelatin hydrogels with <I>in situ</I> hybridization of AgNP for enhanced antimicrobial activities. AgNP were formed through a redox reaction between silver ions and the catechol moieties of a gelatin derivative polymer, without the addition of any chemical reductants. The AgNP with an average size of 20 nm were entrapped within hydrogel matrices and showed sustained release from the hydrogel matrix (8.7% for 14 days). The resulting hydrogels could kill both gram-negative and gram-positive bacteria, depending on the amount of AgNP released from the hydrogels and did not have a significant influence on mammalian cell viability. We believe that our catechol-rich hydrogels <I>in situ</I> hybridizations with AgNP have great potential for biomedical applications, such as wound management and surface coating, because of their excellent antibacterial activities and biocompatibility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Silver nanoparticles incorporation (AgNP) impart the antimicrobial properties to injectable gelatin hydrogel. </LI> <LI> AgNP was <I>in situ</I> synthesized within the hydrogel matrix, with controllable size and sustained release. </LI> <LI> The nanocomposite hydrogels significantly inhibited bacterial growth without affecting viability of mammalian cells. </LI> <LI> These <I>in situ</I> forming GHD/AgNP hydrogels are potential for a wide range of biomedical applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A simple method using catecholic chemistry to prepare an injectable nanocomposite hydrogel with excellent antimicrobial activities. Silver nanoparticles (AgNP) were <I>in situ</I> synthesized within the gelatin hydrogel matrix, during the hydrogelation without use of toxic reductants. The hydrogels inhibited bacterial growth while not affected the viability of mammalian cells. This injectable hydrogel is easy to fabricate <I>in vivo</I> with promising potential for biomedical applications, where advantageous antibacterial activities are required to reduce the infection rates, for example wound dressing, tissue adhesives, biomaterial surface coatings …</P> <P>[DISPLAY OMISSION]</P>

Synthesis of Al₂O₃/Ti₃Al composites by in-situ displacement reactions

Enrique Rocha-Rangel 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.1

The employment of aluminothermic reactions of displacement as an alternative for the production of Al₂O₃/Ti₃Al composite materials has been investigated. Compacted samples from an intensely ground mixture of powders of TiO₂+Al₂O₃ +Al were sintered at 1500ºC during 1 hour by hot pressing in an argon atmosphere. The TiO₂ is used as predecessor to generate in-situ Al₂O₃ via its reduction by means of metallic Al. Al reacts also in a simultaneous way with the reduced titanium to form an intermetallic alloy of the type TixAly. The Al₂O₃ employed in the precursor materials is used as a way for the dissipation of the heat build-up during the aluminothermic reduction of the TiO₂. The results of the characterizations indicate that Al₂O₃- based composite materials were obtained with reinforcement particles of TixAly. The microstructure of these materials is dense, fine and homogeneous. The preliminary characterization of the microstructure and its composition features subsequent to the cycle of in-situ processing are presented here. The employment of aluminothermic reactions of displacement as an alternative for the production of Al₂O₃/Ti₃Al composite materials has been investigated. Compacted samples from an intensely ground mixture of powders of TiO₂+Al₂O₃ +Al were sintered at 1500ºC during 1 hour by hot pressing in an argon atmosphere. The TiO₂ is used as predecessor to generate in-situ Al₂O₃ via its reduction by means of metallic Al. Al reacts also in a simultaneous way with the reduced titanium to form an intermetallic alloy of the type TixAly. The Al₂O₃ employed in the precursor materials is used as a way for the dissipation of the heat build-up during the aluminothermic reduction of the TiO₂. The results of the characterizations indicate that Al₂O₃- based composite materials were obtained with reinforcement particles of TixAly. The microstructure of these materials is dense, fine and homogeneous. The preliminary characterization of the microstructure and its composition features subsequent to the cycle of in-situ processing are presented here.

반응소결된 Si3N4-SiO2-BN 복합체의 기계적 강도 및 유전물성에 관한 연구

이현민,이승준,백승수,김도경 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5

Silicon nitride (Si3N4) is regarded as one of the most promising materials for high temperature structural applications due to itsexcellent mechanical properties at both room and elevated temperatures. However, one high-temperature Si3N4 material intended foruse in radomes has a relatively high dielectric constant of 7.9 - 8.2 at 8 - 10 GHz. In order to reduce the dielectric constant of the Si3N4,an in-situ reaction process was used to fabricate Si3N4-SiO2-BN composites. In the present study, an in-situ reaction between B2O3and Si3N4, with or without addition of BN in the starting powder mixture, was used to form the composite. The in-situ reaction processresulted in the uniform distribution of the constituents making up the composite ceramic, and resulted in good flexural strength anddielectric constant. The composite was produced by pressure-less sintering and hot-pressing at 1650oC in a nitrogen atmosphere. Microstructure, flexural strength, and dielectric properties of the composites were evaluated with respect to their compositions andsintering processes. The highest flexural strength (193 MPa) and lowest dielectric constant (5.4) was obtained for the hot-pressedcomposites. The strength of these Si3N4-SiO2-BN composites decreased with increasing BN content.

반응소결된 Si₃N₄-SiO₂-BN 복합체의 기계적 강도 및 유전물성에 관한 연구

이현민,이승준,백승수,김도경,Lee, Hyun Min,Lee, Seung Jun,Baek, Seungsu,Kim, Do Kyung 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5

Silicon nitride ($Si_3N_4$) is regarded as one of the most promising materials for high temperature structural applications due to its excellent mechanical properties at both room and elevated temperatures. However, one high-temperature $Si_3N_4$ material intended for use in radomes has a relatively high dielectric constant of 7.9 - 8.2 at 8 - 10 GHz. In order to reduce the dielectric constant of the $Si_3N_4$, an in-situ reaction process was used to fabricate $Si_3N_4-SiO_2$-BN composites. In the present study, an in-situ reaction between $B_2O_3$ and $Si_3N_4$, with or without addition of BN in the starting powder mixture, was used to form the composite. The in-situ reaction process resulted in the uniform distribution of the constituents making up the composite ceramic, and resulted in good flexural strength and dielectric constant. The composite was produced by pressure-less sintering and hot-pressing at $1650^{\circ}C$ in a nitrogen atmosphere. Microstructure, flexural strength, and dielectric properties of the composites were evaluated with respect to their compositions and sintering processes. The highest flexural strength (193 MPa) and lowest dielectric constant (5.4) was obtained for the hot-pressed composites. The strength of these $Si_3N_4-SiO_2$-BN composites decreased with increasing BN content.

Investigating continuous co-intercalation of solvated lithium ions and graphite exfoliation in propylene carbonate-based electrolyte solutions

Song, Hee-Youb,Jeong, Soon-Ki Elsevier 2018 Journal of Power Sources Vol.373 No.-

<P><B>Abstract</B></P> <P>Forming an effective solid electrolyte interphase (SEI) is a significant issue in lithium ion batteries that utilize graphite as a negative electrode material, because the SEI determines the reversibility of the intercalation and de-intercalation of lithium ions into graphite for secondary batteries. In propylene carbonate (PC)-based electrolyte solutions, ceaseless co-intercalation of solvated lithium ions takes place because no effective SEI is formed. It is indisputable that this continuous co-intercalation leads to graphite exfoliation; however, the reason for this is currently not well understood. In this study, we investigate interfacial reactions that contribute to SEI formation on highly oriented pyrolytic graphite (HOPG) in ethylene carbonate (EC) and PC-based electrolyte solutions by in situ atomic force microscopy. The blisters formed on HOPG after the decomposition of solvated lithium ions within the graphite layers do not change over the course of ten electrochemical cycles in an EC-based electrolyte solution. In contrast, when cycling in PC-based electrolytes, the blisters continually change, and the height at the vicinity of the graphite edge plane increases. These morphological changes are attributed to the continuous co-intercalation of solvated lithium ions in PC-based electrolyte solutions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Graphite exfoliation is a problem in propylene carbonate (PC)-based electrolytes. </LI> <LI> Interfacial reactions affecting SEI formation were studied by in-situ AFM and CV. </LI> <LI> No changes were observed over 10 cycles in ethylene carbonate-based electrolytes. </LI> <LI> Overlapping blisters caused graphite exfoliation in PC-based electrolytes. </LI> <LI> PC-solvated Li ions can pass through the blister structures freely. </LI> </UL> </P>

A fabricated microfluidic paper-based analytical device (μPAD) for in situ rapid colorimetric detection of microorganisms in environmental water samples

김자영,여민경 대한독성 유전단백체 학회 2016 Molecular & cellular toxicology Vol.12 No.1

In this study, we developed a fabricated microfluidic paper-based analytical device (μPAD) for in situ rapid colorimetric detection of microorganisms in environmental water samples. We fabricated the μPAD with the wax printing method at curing conditions of 100°C for 7 seconds. For quick bacterial detection, we modified the catalase test with Fenton’s reaction as a colorimetric biochemical reaction. This modified catalase test provided a color indicator according to the concentration of Escherichia coli (E. coli , XL-1 Blue strain). All of the image data from the detection chamber of the μPAD was analyzed at the precision of 300 pixels for each color space component (i.e., hue, saturation, and value in HSV color). In addition, environmental samples were tested with our μPAD, and the data were fitted in the range of colorimetric reference chart for E. coli sample testing. Twenty microliters of 50% hydrogen peroxide solution was used for a single-color detection test. Before adding the E. coli sample on the chip, the detection chambers were loaded twice with 1 μL of ferrous sulfate (0.3 g/mL, 0.97 M) and dried. The mean values for all of the samples (n=10) were rounded to the nearest integer. The P values (P<0.01, P<0.05) for all three of the color space components of HSV were considered to be statistically significant.

In-Situ Raman Spectroscopic Evidence of Conproportionation of Methyl Viologen

Choi, Chan Soo 대전대학교 기초과학연구소 2001 自然科學 Vol.12 No.1

전해질 용액중의 메칠 바이올로젼이 충분히 환원된 종, MV°의 산화 스트리핑 반응을 조사하기 위하여 금 전극 위에서 전기화학적 및 인시투 라만 분광학적으로 연구되었다. 최대 네 개의 산화 스트리핑 봉우리가 발견되었다. 첫 번째와 두 번째 스트리핑 봉우리는 MV°의 무정질형과 결정형 각각의 산화에 해당되었다. 셋째 산화 스트리핑 봉우리는 전하 전달(CT) 착물의 산화에 해당되었다. 마지막 산화 스트리핑 봉우리는 메칠 바이올로젼의 양이온 래디컬의 산화에 해당되었다. 이들 반응들은 전형적인 화학-전자 전달 반응(CE 메카니즘)인 것으로 발견되었다. 첫 번째 산화 봉우리 전위에서 나타나기 위한 MV°의 무정질형의 생존시간은 산화환원 순환(ORC) 실험으로부터 약 2.5~5.0초 이하로 밝혀졌고, 지체시간 실험으로부터 0.56~1.4초 이하로 밝혀졌다. CT 착물의 생존시간은 ORC 시험으로부터 0.627~104초 사이인 것으로 밝혀졌다. 인시투 라만 자료는 특징적 MV°. MV^(1+), 및 MV^(2+) 스펙트라를 보였으며 이들 세 가지 화학종을 식별하게 하였다. 균등화반응은 전하 전달 착물 형을 거쳐서 일어나는 것이 발견되었으며 ORC 자료와 1029㎝^(-1) and 994㎝^(-1)의 인시투 란만 변화로부터 고찰될 수 있었다. Methyl viologen in an electrolyte solution was studied electrochemically and in-situ Raman spectroscopically on the Au electrode to examine the anodic stripping reactions of the fully reduced species, MV° The maximum four anodic stripping peaks were found The first anodic stripping peak and the second anodic stripping peak corresponded to oxidations of an amorphous form and a crystalline form of MV°, respectively The third anodic stripping peak corresponded to oxidation of the charge transfer complex The last anodic stripping peak corresponded to oxidation of the cation radical of methyl viologen These reactions were found to be a typical chemical and electron-transfer reaction (CE mechanism) The survival lime of the amorphous form of MV° for appearing at the first anodic peak potential was found to be less than 25 to 50 seconds from oxidation-reduction cycle (ORC) experiments, and less than 056 to 14 seconds from holding time experiments That of the CT complex form was found to be between 0627 seconds and 104 seconds from ORC experiments In-situ Raman data showed characteristic MV°, MV^(+), and MV^(2+) spectra, and allowed us to distinguish between these three species The conproportionation were found to occur through a charge transfer complex form, which could be speculated from the ORC data and the in-situ Raman changes of 1029 cm^(-1) and 994 cm^(-1)

Reaction-induced pore formation and superconductivity in in situ processed MgB₂ superconductors

Kim, C.J.,Yi, J.H.,Jun, B.H.,You, B.Y.,Park, S.D.,Choo, K.N. North-Holland 2014 Physica. C, Superconductivity Vol.502 No.-

The pore formation in in situ processed MgB<SUB>2</SUB> bulk superconductors was systematically examined in terms of a reaction temperature and time. Powder compacts of magnesium (Mg) and boron (B) were heat-treated at a temperature below or above the melt point (m. p., 649<SUP>o</SUP>C) of Mg for various time periods. As the reaction time increased at each reaction temperatures, the size of the powder compacts increased and the compact weight was decreased. The de-densification (so-called the pellet expansion) phenomena at the temperature above the m. p. of Mg was more remarkable. The density decrease was attributed to the three main factors of the pore formation, the out-growth of MgB<SUB>2</SUB> plates and the Mg evaporation during the formation reaction of MgB<SUB>2</SUB>. The microstructure investigation for the initial formation stage of MgB<SUB>2</SUB> at the temperature below the m. p. showed that the pores begun to form at the Mg/matrix interfaces and the spaces that the Mg powders occupied turned into open space (pores) gradually as a reaction time increased. This result indicates that the pores formation at the solid state (temperatures below the m. p.) is attributed to the large difference in diffusivity between Mg and B. In comparison to the solid state, the pore formation at the liquid state (temperatures above the m. p.) was attributed to the melting of Mg powders and the subsequent rapid movement of the melt due to the capillary force. Due to the faster mass transfer through the liquid, the pore formation at temperatures above the m. p. was much faster than that below the m. p. The critical current density of the MgB<SUB>2</SUB> superconductor prepared at 600<SUP>o</SUP>C was higher than that at 900<SUP>o</SUP>C owing the higher pellet density and the smaller grain size.