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        검색결과 22

        3.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        BNKT Ceramics, one of the representative Pb free based piezoelectric ceramics, constitutes a perovskite(ABO3) structure. At this time, the perovskite structure (ABO3) is in the form where the corners of the octahedrons are connected, and in the unit cell, two ions, A and B, are cations, A ion is located at the body center, B ion is located at each corner, and an anion O is located at the center of each side. Since Bi, Na, and K sources constituting the A site are highly volatile at a sintering temperature of 1100℃ or higher, it is difficult to maintain uniformity of the composition. In order to solve this problem, there should be suppression of volatilization of the A site material or additional compensation of the volatilized. In this study, the basic composition of BNKT Ceramics was set to Bi0.5(Na0.78K0.22)0.5TiO3 (= BNKT), and volatile site (Bi, Na, and K sources) were coated in the form of a shell to compensate additionally for the A site ions. In addition, the physical and electrical properties of BNKT and its coated with shell additives(= @BNK) were compared and analyzed, respectively. As a result of analyzing the crystal structure through XRD, both BNKT(Core) and @BNK(Shell) had perovskite phases, and the crystallinity was almost similar. Although the Curie temperature of the two sintered bodies was almost the same (TC = 290 ~ 300 ℃), it was confirmed that the d33 (piezoelectric coefficient) and Pr (residual polarization) values were different. The experimental results indicated that the additional compensation for a shell additive causes the coarsening, resulting in a decrease in sintering density and Pr(remanent polarization). However, coating shell additives to compensate for A site ion is an effective way to suppress volatilization. Based on these experimental results, it would be the biggest advantage to develop an eco-friendly material (Lead-free) that replaced lead (Pb), which is harmful to the human body. This lead-free piezoelectric material can be applied to a biomedical device or products(ex. earphones (hearing aids), heart rate monitors, ultrasonic vibrators, etc.) and skin beauty improvement products (mask packs for whitening and wrinkle improvement).
        4,000원
        4.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon-based materials have emerged as an excellent class of biomedical materials due to their exceptional mechanical properties, lower surface friction, and resistance to wear, tear, and corrosion. Experimental studies have shown the promising results of carbon-based coatings in the field of biomedical implants. The reasons for their successful applications are their ability to suppress thrombo-inflammatory reactions which are evoked as an immune response due to foreign body object implantation. Different types of carbon coatings such as diamond-like carbon, pyrolytic carbon, silicon carbide, and graphene have been extensively studied and utilized in various fields of life including the biomedical industry. Their atomic arrangement and structural properties give rise to unique features which make them suitable for multiple applications. Due to the specificity and hardness of carbon-based precursors, only a specific type of coating technique may be utilized for nanostructure development and fabrication. In this paper, different coating techniques are discussed which were selected based on the substrate material, the type of implant, and the thickness of coating layer. Chemical vapor deposition-based techniques, thermal spray coating, pulsed laser deposition, and biomimetic coatings are some of the most common techniques that are used in the field of biomaterials to deposit a coating layer on the implant. Literature gathered in this review has significance in the field of biomedical implant industry to reduce its failure rate by making surfaces inert, decreasing corrosion related issues and enhancing biocompatibility.
        5,200원
        5.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Medicinal plant-derived carbon dots are eco-friendly and possess therapeutic properties. Among the medicinal plants studied throughout the world, Centella asiatica (L.) Urb. is known for its medicinal values, especially its neuroceutical and cogniceutical properties. This work discusses the green synthesis of carbon dots (CDs) using C. asiatica leaves as the carbon source via fast and cost-effective microwave-assisted method, and its physico-chemical characterization via UV–visible, fluorescence and FTIR spectrometry, XRD, SEM, AFM, TEM, SAED, EDX and zeta potential analyses. The study revealed quasi-spherical CDs having size ~ 3–6 nm, polycrystalline nature, and presence of various functional groups like –COOH, –H, =CH2 and C–O–C with UV absorption peaks at 213 and 322 nm. Interestingly, the C. asiatica-derived CDs exhibited blue fluorescence under UV with maximum emission wavelength of 460 nm when excited at 400 nm. Further, these CDs were evaluated for their biological applications, which uncovered their potential in therapeutics such as antimicrobial properties against both Gram-positive and Gram-negative bacteria at a dose of 10 μg, strong antioxidant activity with IC50 values of 165.28 and 128.48 μg mL− 1 in DPPH and H2O2 assays, respectively, and profound anti-inflammatory activity with IC50 value of 106.20 μg mL− 1 in protein denaturation assay. The CDs were also assessed for cytotoxicity using whole blood cells and were found to be safe for in vitro administration. Thus, the C. asiatica-derived CDs can be exploited for their potent biomedicinal properties. Fluorescent carbon dots (CDs) were prepared by microwave-assisted pyrolysis of Centella asiatica leaf extract and purification. The as synthesized CDs were subjected to various physico-chemical characterization and biomedical assays to understand its properties.
        4,800원
        7.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the past decade, there has been phenomenal progress in the field of nanomaterials, especially in the area of carbon nanotubes (CNTs). In this review, we have elucidated a contemporary synopsis of properties, synthesis, functionalization, toxicity, and several potential biomedical applications of CNTs. Researchers have reported remarkable mechanical, electronic, and physical properties of CNTs which makes their applications so versatile. Functionalization of CNTs has been valuable in modifying their properties, expanding their applications, and reducing their toxicity. In recent years, the use of CNTs in biomedical applications has grown exponentially as they are utilized in the field of drug delivery, tissue engineering, biosensors, bioimaging, and cancer treatment. CNTs can increase the lifespan of drugs in humans and facilitate their delivery directly to the targeted cells; they are also highly efficient biocompatible biosensors and bioimaging agents. CNTs have also shown great results in detecting the SARS COVID-19 virus and in the field of cancer treatment and tissue engineering which is substantially required looking at the present conditions. The concerns about CNTs include cytotoxicity faced in in vivo biomedical applications and its high manufacturing cost are discussed in the review.
        5,500원
        9.
        2021.01 구독 인증기관 무료, 개인회원 유료
        Purpose: The purpose of this study was to describe the perception of biomedical ethics in nurses and nurse’s aide of comprehensive nursing care service. Methods: The subjects were 287 registered nurses and 81 nurse’s aides who were working in comprehensive nursing care service. The data were collected from December 2 to 15, 2019 using a 4-point Likert scale questions. The data were analyzed by descriptive statistics, t-test, ANOVA, Scheffé test and Dunnett T3 test, using the SPSS/WIN 23 program. Results: The average score of perception of biomedical ethics in nurses were 2.95±0.25 and nurse’s aides were 3.08±0.25 points. The perception of biomedical ethics by general characteristics related to age and marital status(p=.001), education(p=.007), a total career length and a career length of comprehensive nursing care service(p<.001), job satisfaction(p=.004) of the nurse biomedical ethics score was high and statistically significant. However, the higher the age of nurse’s aide, the higher the score was statistically significant(p=.007). The perception of biomedical ethics by characteristics related to biomedical ethics was statistically higher among nurses saying that the values of biomedical ethics were very firm (p =.002), those who have experience of having issues biomedical ethics (p =.001), those who believed that rules and procedures for biomedical ethics in a hospital were well organized (p =.003), those who believed that biomedical ethics problems would become more complex and increase in the future (p =.017), and those who experienced ethical dilemmas (p =.019). Conclusion: In the future, biomedical ethics education should be provided for nursing service teams.
        4,800원
        10.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Graphene nanoribbons materialize as a next-generation carrier for development of nanodimensional diagnostic devices and drug delivery systems due to the unique and cutting-edge electronic, thermal, mechanical and optical properties associated with graphene. This review article focuses on the important applications of GNRs in the field of biomedicine and biosensing. Graphene nanoribbons are highly developed form of graphene with a wide importance due to their distinctive properties such as large surface area, enhanced mechanical strength and improved electro-conductivity. GNRs are effective substitutes for conventional silicon-based transistors used in biochemical reactions and exploited in the fields of biomedicine and diagnostics due to their effective uptake by mammalian cells. The cellular interactions of GNRs consist of highly specific receptormediated transport, phagocytosis and non-specific transport systems involving copious forces of adhesion. The presence of quantum chains in GNRs increases their potential for fabrication of technically challenging sensing devices in the future.
        4,200원
        12.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Stem cells are progenitor cells that are capable of self-renewal and differentiation into various cells. Especially, pluripotent stem cells (PSCs) have in vivo and in vitro differentiation capacity into three germ layers and can proliferate infinitely. The differentiation ability of PSCs can be applied for regenerative medicine and tissue engineering. In domestic animals, their PSCs have a potential for preclinical therapy as well as the production of transgenic animals and agricultural usage such as cultured meat. Among several domestic animals, a pig is considered as an ideal model for biomedical and agricultural purposes mentioned above. In this reason, studies for pig PSCs including embryonic stem cells (ESCs), embryonic germ cells (EGCs) and induced pluripotent stem cells (iPSCs) have been conducted for decades. Therefore, this review will discuss the history of PSCs derived from various origins and recent progress in pig PSC research field.
        4,000원
        13.
        2011.12 구독 인증기관 무료, 개인회원 유료
        Cellular uptake of nanoparticles for stem cell labeling and tracking is a critical technique for biomedical therapeutic applications. However, current techniques suffer from low intracellular labeling efficiency and cytotoxic effects, which has led to great interest in the development of a new labeling strategy. Using silica-coated nanoparticles conjugated with rhodamine B isothiocyanate (RITC) (SR), we tested the cellular uptake efficiency, biocompatibility, proliferation or differentiation ability with murine bone marrow derived hematopoietic stem/progenitor cells. The bone marrow hematopoietic cells showed efficient uptake with SR with dose or time dependent manner and also provided a higher uptake on hematopoietic stem/progenitor cells. Biocompatibility tests revealed that the SR had no deleterious effects on cell cytotoxicity, proliferation, or multi-differentiation capacities in vitro and in vivo. SR nanoparticles are advantageous over traditional labeling techniques as they possess a high level of cellular internalization without limiting the biofunctionality of the cells. Therefore, SR provides a useful alternative for gene or drug delivery into hematopoietic stem/progenitor cells for basic research and clinical applications.
        4,000원
        14.
        2011.09 구독 인증기관 무료, 개인회원 유료
        In this study, a nanofibrous scaffold was obtained by co-electrospinning poly (3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) and collagen in 2,2,2-trifluoroethanol at a ratio of 3/7. The fiber diameters were in the range of 250-600 nm. It was found that PHBV/Collagen (PHCP) nanofibrous scaffold showed greater proliferation than the PHBV nanofibrous scaffold induced by oxidant in NIH3T3 cells. Otherwise, in the early-stage wound-healing mouse model, wound closure was evaluated according to wound size reduction and histology of regenerated skin on the backs of mice. Each of the tissues removed on day 0, 3, 6, 9, 12, 15, and 18 was used for analysis of biochemical and pathological changes. None of the nanofiber-attached mice showed significant difference on the third day, however, from the third day until the ninth day, significantly faster healing was observed in PHCP-attached mice, compared to control wounds in epithelialization, wound contraction, and histopathological examinations. These results strongly support the beneficial effects of biomedical application of PHCP nanofiber in acceleration of the initial phase of wound healing through α-SM actin contraction.
        4,000원
        15.
        2007.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Al-42wt%Nb powder was prepared by high-energy mechanical milling(HEMM). The particle size, phase transformation and microstructure of the as-milled powder were investigated by particle size distribution (PSD) analyzer, scanning electron microscopy (SEM), X-ray diffractometery (XRD), transmission electron microscopy (TEM)and differential thermal analysis (DTA). The milled powders were heated to a sintering temperature at 1000C with under vaccum with vaccum tube furnace. Microstructural examination of sintered Ti-42wt%Nb alloy using 4h-milled powder showed Ti-rich phases (α-Ti) which are fine and homogeneously distributed in the matrix (Nb-rich phase: β-Ti). The sintered Ti-42wt%Nb alloy with milled powder showed higher hardness. The microstructure of the as quenched specimens fabricated by sintering using mixed and milled powder almost are same, but the hardness of as quenched specimen fabricated by using mixed powder increased due to solution hardening of Nb in Ti matrix. The aging effect of these specimens on microstructural change and hardening is not prominent.
        4,000원
        17.
        2006.04 구독 인증기관·개인회원 무료
        Direct Metal Laser Sintering (DMLS) has been utilized for prototype manufacturing of functional metal components for years now. During this period the surface quality, mechanical properties, detail resolution and easiness of the process have been improved to the level suitable for direct production of complex metallic components for various applications. The paper will present the latest DMLS technology utilizing EOSINT M270 laser sintering machine and EOSTYLE support generation software for direct and rapid production of complex shaped metallic components for various purposes. The focus of the presentation will be in rapid manufacturing of customized biomedical implants and surgical devices of the latest stainless steel, titanium and cobalt-chromium-molybdenum alloys. In addition to biomedical applications, other application areas where complex metallic parts with stringent requirements are being needed will be presented.
        19.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        21세기를 선도할 기술로 전 세계적으로 각광을 받고 연구가 활발히 진행되고 있는 분야는 나노기술(W), 생명공학기술(BT), 정보통신기술(IT)이라고 할수 있다. 우리나라에서도 최근 이에 대한 연구 및 교육 지원 프로그램을 세워 법정부적으로 지원을 하고 있다. 특히 나노기술은 다른 분야와의 기술융합이 가장 활발하게 진행되고 있다. 이러한 분야들은 우리나라와 같이 부존자원이 매우 적은 나라로써는 세계열강과 경쟁하기 위한 새로운 돌파구로 활용될 수 있을 것
        4,000원
        20.
        2000.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
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