Magnetic tunnel junctions (MTJs), which consisted of amorphous ferromagnetic NiFeSiB free layers, were investigated. The NiFeSiB layers were used to substitute for the traditionally used CoFe and/or NiFe layers with the emphasis being given to obtaining an understanding of the effect of the amorphous free layer on the switching characteristics of the MTJs. $Ni_{16}Fe_{62}Si_{8}B_{14}$ has a lower saturation magnetization ($M_{s}:\;800\;emu/cm^{3}$) than $Co_{90}Fe_{10}$ and a higher anisotropy constant ($K_{u}:\;2700\;erg/cm^{3}$) than $Ni_{80}Fe_{20}$. The $Si/SiO_{2}/Ta$ 45/Ru 9.5/IrMn 10/CoFe $7/AlO_{x}/CoFeSiB\;(t)/Ru\;60\;(in\;nanometers)$structure was found to be beneficial for the switching characteristics of the MTJ, leading to a reduction in the coercivity ($H_{c}$) and an increase in the sensitivity resulted from its lower saturation magnetization and higher uniaxial anisotropy. Furthermore, by inserting a very thin CoFe layer at the tunnel barrier/NiFeSiB interface, the TMR ratio and switching squareness were improved more with the increase of NiFeSiB layer thickness up to 11 nm.
Curcumin, of which a critical characteristic is the capacity of crossing the blood-brain barrier, has been reported to induce the expression of neuroprotective heme oxygenase (HO)-1. The aim of this study is to compare HO-1-inducing capacity and neuroprotective activity of curcumin, its demethoxy (demethoxycurcumin, DMC; bis-demethoxycurcumin, BDMC) and hydrogenated derivatives (tetrahydrocurcumin, THC) in mouse hippocampal HT22 cells. Curcumin attenuated glutamate-induced cell death through HO-1 expression. DMC lacking a methoxy group on one of the aromatic rings possessed slightly lower activity in HO-1 expression and neuroprotection than curcumin. Similarly, BDMC, which lacks two methoxy groups on both of the aromatic rings, showed less activity than curcumin. These findings suggest that the presence of methoxy groups on the aromatic ring is required to enhance neuroprotective HO-1 expression. The reduction of the diarylheptadienone chain of curcumin by hydrogen, as in THC, was accompanied by a complete loss of ability to induce HO-1 expression and neuroprotection, suggesting that the conjugated double bonds of the central seven-carbon chain of curcumin may be essential for its ability to induce neuroprotective HO-1 expression. Our findings may provide useful information for further development of neuroprotective HO-1 inducers.
Lee Jung-Min;Kim Yung-Soo;Kim Chang-Whe;Han Jung-Suk
The Journal of Korean Academy of Prosthodontics
/
v.41
no.3
/
pp.325-341
/
2003
Statement of problem: In cases where bony defects were present, guided bone regenerations have been performed to aid the placement of implants. Nowadays, the accepted concept is to isolate bone from soft tissue by using barrier membranes to allow room for generation of new bone. Nonresorbable membranes have been used extensively since the 1980's. However, this material has exhibited major shortcomings. To overcome these faults, efforts were made to develop resorbable membranes. Guided bone regenerations utilizing resorbable membranes were tried by a number of clinicians. $Bio-Gide^{(R)}$ is such a bioresorbable collagen that is easy to use and has shown fine clinical results. Purpose: The aim of this study was to evaluate the histological results of guided bone regenerations performed using resorbable collagen membrane($Bio-Gide^{(R)}$) with autogenous bone, bovine drived xenograft and combination of the two. Surface morphology and chemical composition was analyzed to understand the physical and chemical characteristics of bioresorbable collagen membrane and their effects on guided bone regeneration. Material and methods: Bioresorbable collagen membrane ($Bio-Gide^{(R)}$), Xenograft Bone(Bio-Oss), Two healthy, adult mongrel dogs were used. Results : 1. Bioresorbable collagen membrane is pure collagen containing large amounts of Glysine, Alanine, Proline and Hydroxyproline. 2. Bioresorbable collagen membrane is a membrane with collagen fibers arranged more loosely and porously compared to the inner surface of canine mucosa: This allows for easier attachment by bone-forming cells. Blood can seep into these spaces between fibers and form clots that help stabilize the membrane. The result is improved healing. 3. Bioresorbable collagen membrane has a bilayered structure: The side to come in contact with soft tissue is smooth and compact. This prevents soft tissue penetration into bony defects. As the side in contact with bone is rough and porous, it serves as a stabilizing structure for bone regeneration by allowing attachment of bone-forming cells. 4. Regardless of whether a membrane had been used or not, the group with autogenous bone and $Bio-Oss^{(R)}$ filling showed the greatest amount of bone fill inside a hole, followed by the group with autogenous bone filling, the group with blood and the group with $Bio-Oss^{(R)}$ Filling in order. 5. When a membrane was inserted, regardless of the type of bone substitute used, a lesser amount of resorption occurred compared to when a membrane was not inserted. 6. The border between bone substitute and surrounding bone was the most indistinct with the group with autogenous bone filling, followed by the group with autogenous bone and $Bio-Oss^{(R)}$ filling, the group with blood, and the group with $Bio-Oss^{(R)}$ filling. 7. Three months after surgery, $Bio-Gide^{(R)}$ and $Bio-Oss^{(R)}$ were distinguishable. Conclusion: The best results were obtained with the group with autogenous bone and $Bio-Oss^{(R)}$ filling used in conjunction with a membrane.
PURPOSE. The objective of this study was to conduct an in vitro comparative evaluation of polished and laser-dimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti. MATERIALS AND METHODS. Forty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had $5-{\mu}m$ dimples at $10-{\mu}m$ intervals, and SM30 (n=16) had $5-{\mu}m$ dimples at $25-{\mu}m$ intervals in a $2{\times}4mm^2$ area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences. RESULTS. The adhesion strength of epithelial cells was higher on Ti surfaces with $5-{\mu}m$ laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins. CONCLUSION. These findings demonstrate that laser dimpling may contribute to improving the peri-implant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment.
Modified atmosphere packaging (MAP) was evaluated for the storage of pumpkin rice cake as a means of preserving quality and extending shelf-life. Retail-sized amounts of rice cake were packaged in trays under different modified atmosphere conditions (air, vacuum, 60% $CO_2$/40% $N_2$ and 100% $CO_2$) using gas-barrier plastic film; control was in air-permeable stretch wrap. The packages were stored at $20^{\circ}C$ with periodical measurement of package atmosphere and cake quality attributes. The modified atmosphere packages of 60% $CO_2$/40% $N_2$ and 100% $CO_2$ inhibited the growth of molds/yeasts completely and significantly retarded the growth of aerobic bacteria. All the packages except that of 100% $CO_2$ showed the reduction of internal $O_2$ concentration and increase of the $CO_2$ with storage time due to the microbial activity. There has been slight decrease of $CO_2$ concentration for 60% $CO_2$/40% $N_2$ and 100% $CO_2$ packages just after start of the storage possibly due to dissolution of headspace $CO_2$ into the cake. Any MAP conditions did not affect the retrogradation of the rice cake. Surface color of the cake within affordable microbial quality limit was not affected significantly by packaging conditions.
Journal of the Korean Society for Library and Information Science
/
v.49
no.2
/
pp.51-73
/
2015
The Web now provides instant access to an unprecedented amount of information that was unthinkable even 20-30 years ago. However, the full potential of the contents available through the Internet can only be realized when one can speak and understand foreign languages, especially English which accounts for more than half of web contents. In this study, we try to investigate the effect of search task languages and task complexity on searching performance. A total of thirty students enrolled at a top private university in Korea were recruited as study subjects. We set up a quasi-experimental design in which thirty subjects are randomly assigned to a set of eight different search tasks containing an equal number of simple and complex tasks and an equal number of tasks in Korean and in English. The results show that there is a significant difference between simple and complex tasks in terms of SERP time, number of queries used, correctness of results and total search time. However, task language does not seem to have affected search performance for this study group. In addition, students with high English proficiency test scores show comparable search performance in English tasks compared with lower test scores. But we note differences in behavioral patterns (different search engines used and search tactics) among the study participants.
The crystallized CuPc(copper phthalocyanine) film on a p-type <100> Si substrate is prepared at the substrate temperature of $300^{\circ}C$ by thermal evaporation. X -ray diffraction analysis showed the CuPc film to have a-axis oriented structure. For the measurement of photovoltaic characteristics of the CuPc/Si film and the Si substrate, a transverse current-voltage (I-V) curve is observed. In the dark, the Au/Si junction is shown to be ohmic contact. However, under illumination, a photovoltaic effect is not observed. The I-V curve in the dark indicates that the CuPc film on Si may form an ohmic contact. Since the CuPc film is a p-type semiconductor, the CuPc/p-Si junction has no barrier at the interface. Under illumination, the CuPc/Si junction shows a large photocurrent comparing with that of the wafer. The result indicates that the CuPc layer plays an important role in the photocarrier generation under red illumination (600 nm). The CuPc/Si film shows the photo voltaic characteristics with a short-circuit photocurrent ($J_{sc}$) of $4.29\;mA/cm^{2}$ and an open-circuit voltage ($V_{oc}$) of 12 mA.
The purpose of this study was to look into impacts of career barriers and college major satisfactions on career preparation behaviors of Security major college students. The subjects of this study were collected among 200 security major students attending universities in Choungnam and Junnam Provinces, and 170 out of 200 were analyzed. Based on collected data, exploratory factor analysis, correlation analysis, multiple regression analysis, and one-way ANOVA were conducted using SPSS 18.0. According to the result, career barriers showed negative correlations on career preparation behaviors, and self-concept clarity deficiency showed significant impact on it. College major satisfactions showed positive correlations, and major satisfaction showed significant impact on it. Also result shows college junior and senior students experience less career barriers compare to freshman and sophomore students, and college junior and senior students were more satisfied on the college major satisfactions as well. The study has found important implications of impacts of career barriers and college major satisfaction on career preparation behaviors. In long term, the finding of the study seem to provide useful insights for security major students and Human Resource Personnel to execute the process of career preparations and related counseling effectively.
The relationships between children's health behavior and variables that effect children's health behavior has been investigated in a number of previous studies. This study was conducted to examine the effects of a peer's social reinforcement on children's dental health behavior in an elementary school. The research design was a nonequivalent pre and post-test quasi-experimental design and the study subjects with one hundred and thirteen eight to nine years old children, and their mothers (57 experimental group, 56 control group) were selected as a study group. Subjects were selected by the convenience sampling method. The study was carried out in an elementary school in Namwon city, Korea, from the 26th of April to the 12th of June in 1999. Data were collected in both the pre and post-test portions. Using the "Health Belief Model", each item of the questionnaire for measurement of dental health behavior was modified and administered for the children and their mothers. The questionnaire for the measurement of dental health behavior was developed by Oh, Y.B.(1994). The Cronbach's ${\alpha}$ of the questionnaire for children were .81, and for the mother were .79. In this study, the health belief model consists of "perceived susceptibility", "perceived seriousness", "perceived barrier", "perceived salience", and "perceived benefit". The questionnaire for the children was composed of 37 items, and the questionnaire for the mother was composed of 40 items. Data were analyzed by frequency, ${\chi}^2-test$, ANOVA, Pearson's Correlation, and multiple regression analysis by a SAS program. The results of this study were summarized as follows ; 1. The first hypothesis that the experimental group would have more change in the frequency of brushing per week than that of control group was accepted(t=3.817, p=0.000). Mean tooth brushing scores in the experimental group improved significantly from pre-test to post-test, but in the control group there was no significant improvement in tooth brushing scores. 2. The second hypothesis that the experimental group would have more change in score of dental health behavior than that of control group was accepted(benefit : t=2.804, p=0.006, salience: t=2.608, p=0,010). An evaluation between the experimental group and the control group showed significant change from pre-test to post-test in health behavior scores. 3. The third hypothesis that higher scores of social reinforcement would create more change in the scores of tooth brushing frequency in the experimental group was accepted(${\beta}$=0.169, p=0.000. Multiple regression was used to examine the peer's social reinforcement scores and the relative influence of significant variables in previous ANOVA and Pearson's correlation test on children's frequency of brushing during the post-test. The results of the study indicated that the combination of social reinforcement of peers with variables pertaining to mother and householder were significantly related and effectively improved a child's tooth brushing.
Kim, Keyyoung;Paik, Namwon;Kim, Yonghee;Yoo, Kwanho
Journal of Korean Society of Occupational and Environmental Hygiene
/
v.28
no.1
/
pp.61-79
/
2018
Objectives: The objective of this study was to examine the effect of non-thermal dielectric barrier discharge(DBD) plasma on decontamination of Staphylococcus aureus(S. aureus) and Escherichia coli(E. coli) as common pathogens. Methods: This experiment was carried out in a chamber($0.64m^3$)designed by the authors. The plasma was continuously generated by a non-thermal DBD plasma generator(Model TB-300, Shinyoung Air tech, Korea). Suspensions of S. aureus and E. coli of 0.5 McFarland standard($1.5{\times}10^8CFU/mL$) were prepared using a Densi-Check photometer(bio $M{\acute{e}}rieux$, France). The suspensions were diluted1:1000 in sterile PBS solutions(approximately$10^{4-5}CFU/mL$) and inoculated on tryptic soy agar(TSA) in Petri dishes. The Petri dishes(80mm internal diameter)were exposed to the non -thermal DBD plasma in the chamber. Results: The results showed that 95% of S. aureus colonies were killed after a six-hour exposure to the DBD plasma. In the case of E. coli, it took two hours to kill 100% of the colonies. The gram-negative E. coli had a greater reduction than the gram-positive S. aureus. This difference may be due to the structure of their cell membranes. The thickness of gram-positive bacteria is greater than that of gram-negative bacteria. The S. aureus is more resistant to DBD plasma exposures than is E. coli. It should be noted that average concentrations of ozone, a byproduct of the DBD plasma generator, were monitored throughout the experiment and the results were well below the criteria, 50 ppb, recommended by the Korean Ministry of the Environment. Thus, non-thermal DBD plasma is deemed safe for use in hospital and public facilities. Conclusions: There was evidence that non-thermal DBD plasma can effectively kill S. aureus and E. coli. The results indicate that DBD plasma technology can greatly contribute to the control of infections in hospitals and other public and private facilities.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.