• Title/Summary/Keyword: Magnetic beads

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Removal of Cu(II) ions by Alginate/Carbon Nanotube/Maghemite Composite Magnetic Beads

  • Jeon, Son-Yeo;Yun, Ju-Mi;Lee, Young-Seak;Kim, Hyung-Il
    • Carbon letters
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    • v.11 no.2
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    • pp.117-121
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    • 2010
  • The composites of alginate, carbon nanotube, and iron(III) oxide were prepared for the removal of heavy metal in aqueous pollutant. Both alginate and carbon nanotube were used as an adsorbent material and iron oxide was introduced for the easy recovery after removal of heavy metal to eliminate the secondary pollution. The morphology of composites was investigated by FE-SEM showing the carbon nanotubes coated with alginate and the iron oxide dispersed in the alginate matrix. The ferromagnetic properties of composites were shown by including iron(III) oxide additive. The copper ion removal was investigated with ICP AES. The copper ion removal efficiency increased greatly over 60% by using alginate-carbon nanotube composites.

Fabrication and Characteristics of a Highly Sensitive GMR-SV Biosensor for Detecting of Micron Magnetic Beads (미크론 자성비드 검출용 바이오센서에 대한 고감도 GMR-SV 소자의 제작과 특성 연구)

  • Choe, Jong-Gu;Park, Gwang-Jun;Lee, Ju-Hyeong;Lee, Sang-Seok;Lee, Jang-Ro
    • Proceedings of the Korean Magnestics Society Conference
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    • 2012.11a
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    • pp.146-148
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    • 2012
  • 미크론 자성비드 검출용 바이오센서에 활용하는 GMR-SV 박막을 이온빔 스퍼터링 증착법으로 glass/Ta(5.8 nm)/NiFe(5 nm)/Cu(t nm)/NiFe(3 nm)/FeMn(12 nm)/Ta(5.8 nm)의 구조를 갖도록 증착하였다. 비자성체 Cu의 두께가 3.0 nm에서 2.2 nm까지 얇아질수록 교환결합력은 증가하였으며 자기저항비는 다소 낮았다. 비자성체의 두께가 얇으면 반강자성체의 층간 교환작용이 강자성체의 고정층 뿐만 아니라 자유층의 스핀배열에도 영향을 주고 있음을 확인할 수 있었다. 또한 리소그래피 공정 과정을 거쳐 GMR-SV 소자를 제작하여 미트론 자기비드를 검출하였다. 여기서 자기비드를 떨어뜨리기 전과 후의 자기저항비, 교환결합력, 보자력은 각각 0.9%, 3 Oe, 2 Oe의 값을 나타내었다. 이것으로 미크론단위의 바이오센서로서 활용할 수 있는 가능성을 보여주었다.

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Fluroscopic Removal of the Foreign Bodies from Gastroesophagus Using the Magnet (자석을 이용한 식도 위 이물 제거술)

  • Park, Youn-Joon;Lee, Doo-Sun
    • Advances in pediatric surgery
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    • v.13 no.2
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    • pp.112-118
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    • 2007
  • Ingested foreign bodies are common occurrences in the pediatric population. From October 2002 to April 2006, eight patients (6 male, mean age: $30.9{\pm}14.4$ months, range: 7~45 months) who had ingested metallic foreign bodies, such as bar magnets, coin-type magnets, screws, metal beads, and disk batteries, were selected for foreign body removal using a magnetic device under floroscopic control. A 1-cm-long cylindrical magnet (6 mm in diameter) was placed at the end of a 150-cm-long plastic tube from an IV set. The magnet was passed through the mouth into the stomach. Under fluoroscopic control, the magnet was maneuvered so that it attached to the metallic foreign bodies. The forgeign body was then easily removed by retracting the magnet with the metallic object attached. This procedure was successful in six patients of 8 patients. This procedure is a minimally-invasive and may avoid the use of anesthesics, endoscopy or surgery.

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Opsonized Streptococcus mutans influenced maturation of human dendritic cells

  • Ida, N.;Ozaki, K.;Suenobu, S.;Takashi, K.;Yamaguchi, D.;Matsuo, T.
    • Proceedings of the KACD Conference
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    • 2003.11a
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    • pp.602-602
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    • 2003
  • I. Objectives It is reported that there are complements and immunogloblins in serum from dental pulp in dentinal tubules, and it is thought that dental caries bacteria is opsonized by these serum ingredients, and it is presented by dendritic cells(DCs) in dental pulp. So, we examined whether a maturational difference of DCs occured when S. mutans was opsonized. II. Materials and Methods PBMC was divided from normal human peripheral blood and collected CD14 positive cells by magnetic beads system. Adherent cells were incubated in 5% FCS-RPMI medium included GM-CSF, IL-4 for seven days.(omitted)

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Regional Distribution of Isotropy Magnetic Property of Dual-type Giant Magnetoresistance-Spin Valve Multilayer (이중구조 거대자기저항-스핀밸브 박막의 자기등방성 영역분포에 관한 연구)

  • Khajidmaa, Purevdorj;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • v.23 no.6
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    • pp.193-199
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    • 2013
  • The regional distribution of magnetic isotropy depending on the post annealing condition for the dual-type structure GMR-SV (giant magnetoresistance-spin valve) of NiFe/Cu/NiFe/IrMn/NiFe/Cu/NiFe multilayer was investigated. The rotation of in-plane ferromagnetic layer induced by controlment of the post annealing temperature inside of the vacuum chamber. The magnetoresistive curves of a dual-type IrMn based GMR-SV depending on the direction of the magnetization easy axis of the free layer and the pinned layer are measured by between $0^{\circ}$ and $360^{\circ}$ angles for the applied fields. The optimum annealing temperature having a steady and isotropy magnetic sensitivity of 1.52 %/Oe was $107^{\circ}C$ in the rotational section of $0{\sim}90^{\circ}$. By investigating the switching process of magnetization for an arbitrary measuring direction, the in-plane orthogonal magnetization for the dual-type GMR-SV multilayer can be used by a high sensitive biosensor for detection of magnetized micro-beads.

Rapid, Sensitive, and Specific Detection of Salmonella Enteritidis in Contaminated Dairy Foods using Quantum Dot Biolabeling Coupled with Immunomagnetic Separation

  • Kim, Hong-Seok;Chon, Jung-Whan;Kim, Hyunsook;Kim, Dong-Hyeon;Yim, Jin-Hyuk;Song, Kwang-Young;Kang, Il-Byung;Kim, Young-Ji;Lee, Soo-Kyung;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.33 no.4
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    • pp.271-275
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    • 2015
  • Colloidal semiconductor CdSe-ZnS core-shell nanocrystal quantum dot (Qdot) are luminescent inorganic fluorophores that show potential to overcome some of the functional limitations encountered with organic dyes in fluorescence labeling applications. Salmonella Enteritidis has emerged as a major cause of human salmonellosis worldwide since the 1980s. A rapid, specific, and sensitive method for the detection of Salmonella Enteritidis was developed using Qdot as a fluorescence marker coupled with immunomagnetic separation. Magnetic beads coated with anti-Salmonella Enteritidis antibodies were employed to selectively capture the target bacteria, and biotin-conjugated anti-Salmonella antibodies were added to form sandwich immune complexes. After magnetic separation, the immune complexes were labeled with Qdot via biotin-streptavidin conjugation, and fluorescence measurement was carried out using a fluorescence measurement system. The detection limit of the Qdot method was a Salmonella Enteritidis concentration of $10^3$ colony-forming units (CFU)/mL, whereas the conventional fluorescein isothiocyanate-based method required over $10^5CFU/mL$. The total detection time was within 2 h. In addition to the potential for general nanotechnology development, these results suggest a new rapid detection method of various pathogenic bacteria from a complex food matrix.

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Characterization of growth hormone-like sequence of loach, Misgurnus mizolepis (미꾸라지 성장 호르몬 염기 서열의 특성에 대하여)

  • Kim, Jin-Kyung;Song, Young-Hwan
    • Journal of fish pathology
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    • v.7 no.2
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    • pp.95-103
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    • 1994
  • We have prepared cDNA libray of loach. M. mizolepis in order to isolate cDNA clone of growth hormone gene. Total RNA was isolated from pituitary of loach, and then mRNA was further purified from total RNA by oligo (dT)-coupled magnetic beads. The purified mRNA was used as substrates to prepare cDNA. The resulting cDNA was ligated into the EcoRV/Smal site of pBlueKS+. The ligation mixture have transformed E. coli JM109 strain with electroporator to obtain high yield of transformation efficiency. All the transformants was screened with DIG-labeled Tilapia growth hormone gene by high density colony hybridization. After isolating 10 putative colonies showing the positive signals, secondary colony hybridization and southern hybridization could confirm it as true clones. The nucleotide sequence of one candidate, pCGHI, was compared with 312 bp DNA fragment used as DNA probe and show 52% relative homology to Tilapia growth hormone gene.

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Comparative Serum Proteomic Analysis of Serum Diagnosis Proteins of Colorectal Cancer Based on Magnetic Bead Separation and MALDI-TOF Mass Spectrometry

  • Deng, Bao-Guo;Yao, Jin-Hua;Liu, Qing-Yin;Feng, Xian-Jun;Liu, Dong;Zhao, Li;Tu, Bin;Yang, Fan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.6069-6075
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    • 2013
  • Background: At present, the diagnosis of colorectal cancer (CRC) requires a colorectal biopsy which is an invasive procedure. We undertook this pilot study to develop an alternative method and potential new biomarkers for diagnosis, and validated a set of well-integrated tools called ClinProt to investigate the serum peptidome in CRC patients. Methods: Fasting blood samples from 67 patients diagnosed with CRC by histological diagnosis, 55 patients diagnosed with colorectal adenoma by biopsy, and 65 healthy volunteers were collected. Division was into a model construction group and an external validation group randomly. The present work focused on serum proteomic analysis of model construction group by ClinProt Kit combined with mass spectrometry. This approach allowed construction of a peptide pattern able to differentiate the studied populations. An external validation group was used to verify the diagnostic capability of the peptidome pattern blindly. An immunoassay method was used to determine serum CEA of CRC and controls. Results: The results showed 59 differential peptide peaks in CRC, colorectal adenoma and health volunteers. A genetic algorithm was used to set up the classification models. Four of the identified peaks at m/z 797, 810, 4078 and 5343 were used to construct peptidome patterns, achieving an accuracy of 100% (> CEA, P<0.05). Furthermore, the peptidome patterns could differentiate the validation group with high accuracy close to 100%. Conclusions: Our results showed that proteomic analysis of serum with MALDI-TOF MS is a fast and reproducible approach, which may provide a novel approach to screening for CRC.

Development of an Automatic PCR System Combined with Magnetic Bead-based Viral RNA Concentration and Extraction

  • MinJi Choi;Won Chang Cho;Seung Wook Chung;Daehong Kim;Il-Hoon Cho
    • Biomedical Science Letters
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    • v.29 no.4
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    • pp.363-370
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    • 2023
  • Human respiratory viral infections such as COVID-19 are highly contagious, so continuous management of airborne viruses is essential. In particular, indoor air monitoring is necessary because the risk of infection increases in poorly ventilated indoors. However, the current method of detecting airborne viruses requires a lot of time from sample collection to confirmation of results. In this study, we proposed a system that can monitor airborne viruses in real time to solve the deficiency of the present method. Air samples were collected in liquid form through a bio sampler, in which case the virus is present in low concentrations. To detect viruses from low-concentration samples, viral RNA was concentrated and extracted using silica-magnetic beads. RNA binds to silica under certain conditions, and by repeating this binding reaction, bulk samples collected from the air can be concentrated. After concentration and extraction, viral RNA is specifically detected through real-time qPCR (quantitative polymerase chain reaction). In addition, based on liquid handling technology, we have developed an automatic machine that automatically performs the entire testing process and can be easily used even by non-experts. To evaluate the system, we performed air sample collection and automated testing using bacteriophage MS2 as a model virus. As a result, the air-collected samples concentrated by 45 times then initial volume, and the detection sensitivity of PCR also confirmed a corresponding improvement.

Microdevice for Separation of Circulating Tumor Cells Using Embedded Magnetophoresis with V-shaped Ni-Co Nanowires and Immuno-nanomagnetic Beads

  • Park, Jeong Won;Lee, Nae-Rym;Cho, Sung Mok;Jung, Moon Youn;Ihm, Chunhwa;Lee, Dae-Sik
    • ETRI Journal
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    • v.37 no.2
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    • pp.233-240
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    • 2015
  • The novelty of this study resides in a 6"-wafer-level microfabrication protocol for a microdevice with a fluidic control system for the separation of circulating tumor cells (CTCs) from human whole blood cells. The microdevice utilizes a lateral magnetophoresis method based on immunomagnetic nanobeads with anti-epithelial cell adhesive molecule antibodies that selectively bind to epithelial cancer cells. The device consists of a top polydimethylsiloxane substrate for microfluidic control and a bottom substrate for lateral magnetophoretic force generation with embedded v-shaped soft magnetic microwires. The microdevice can isolate about 93% of the spiked cancer cells (MCF-7, a breast cancer cell line) at a flow rate of 40/100 mL/min with respect to a whole human blood/buffer solution. For all isolation, it takes only 10 min to process 400 mL of whole human blood. The fabrication method is sufficiently simple and easy, allowing the microdevice to be a mass-producible clinical tool for cancer diagnosis, prognosis, and personalized medicine.