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1.
J Vet Sci ; 21(6): e86, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33263233

ABSTRACT

BACKGROUND: Dicyemids are parasites found in the renal sac of cephalopods. The first species of dicyemid was found from kidneys of the Korean common octopus Callistoctopus minor. OBJECTIVES: This study aimed to identify the dicyemid and investigate the effect on renal sac of host. METHODS: In this study, we compared the morphological characteristics of isolate to dicyemids (Dicyema sphyrocephalum, Dicyema clavatum, and Dicyema dolichocephalum) reported from C. minor in Japan. We compared the 18S ribosomal RNA (rDNA) and cytochrome c oxidase subunit I (COI) sequences of isolate to the sequences of D. shyrocephalum and D. clavatum. The infected octopuses renal tissues were histologically compared with the tissues of uninfected individuals. RESULTS: The morphological characteristic of this isolated species corresponds to D. sphyrocephalum. The sequences similarities of 18S rDNA and COI gene of isolate are 99.7% and 98.1% with D. sphyrocephalum. We observed morphological changes in the epithelia folds of kidney at the dicyemids attached areas. CONCLUSIONS: The present study identified the isolate as D. sphyrocephalum and this is the first report of dicyemid species from Republic of Korea. Further studies on the effects of dicyemids on growth and health status of cephalopods will be needed.


Subject(s)
Animal Distribution , Invertebrates/physiology , Octopodiformes/parasitology , Animals , Electron Transport Complex IV/analysis , Invertebrates/genetics , Kidney/parasitology , Phylogeny , RNA, Ribosomal, 18S/analysis , Republic of Korea
2.
Arthroscopy ; 36(1): 150-155, 2020 01.
Article in English | MEDLINE | ID: mdl-31864569

ABSTRACT

PURPOSE: The purposes of this study are (1) to measure the ischiofemoral distance (IFD) in nondiseased hips and (2) to reveal patient demographic and anatomical factors associated with IFD. METHODS: In this retrospective study, we identified patients who had unilateral osteonecrosis of the femoral head on computed tomography (CT) scan from November 2005 to July 2018 and assessed the unaffected contralateral hips of the patients. Among the contralateral hips, we excluded hips with hip pain, incomplete or poor-quality CT image, incomplete medical record, degenerative arthritis of the hip, or previous hip surgery. IFD was measured on the axial CT image, and correlated demographic factors (age, sex, height, weight, and body mass index) and anatomical parameters (neck-shaft angle of the femur and femoral anteversion) with IFD were evaluated. RESULTS: Five hundred seventeen patients (517 hips) were evaluated. There were 302 men and 215 women, and their mean age was 51.7 years (range 15-83 years). The mean IFD was 33.2 (±9.2) mm in men and 24.3 (±8.9) mm in women (P < .001). Interobserver and intraobserver reliability (intraclass correlation coefficients) were 0.99 (95% confidence interval 0.98-1.0) and 0.98 (95% confidence interval 0.97-0.99), respectively. The mean neck-shaft angle was 129.31° ± 5.04° in males and 129.93° ± 6.29° in females. The mean femoral anteversion was 9.72° ± 7.95° in males and 12.61° ± 8.91° in females. IFD was positively correlated with height (correlation coefficient [r] = 0.464, P < .001) and weight (0.286, P < .001), whereas it was negatively correlated with age (-0.198, P < .001), neck-shaft angle (-0.123, P = .005), and femoral anteversion (-0.346, P < .001). There was no correlation between body mass index and IFD (P = .522). In multivariate regression analysis, IFD was positively associated with height (ß = .632), and negatively associated with neck-shaft angle of the femur and femoral anteversion (ß = -0.155 and -0.328. respectively). CONCLUSIONS: In asymptomatic hips, the mean IFD was 33.2 ± 9.2 mm in males and 24.3 ± 8.9 mm in females. The IFD was positively correlated with height and negatively with neck-shaft angle of the femur and femoral anteversion. LEVEL OF EVIDENCE: Level III, retrospective comparative study.


Subject(s)
Femoracetabular Impingement/diagnosis , Femur/diagnostic imaging , Ischium/diagnostic imaging , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Aged, 80 and over , Asymptomatic Diseases , Female , Follow-Up Studies , Humans , Male , Middle Aged , ROC Curve , Reproducibility of Results , Retrospective Studies , Young Adult
3.
Surg Technol Int ; 35: 417-421, 2019 11 10.
Article in English | MEDLINE | ID: mdl-31571188

ABSTRACT

INTRODUCTION: Osteonecrosis of the femoral head (ONFH) usually affects patients younger than 50 years and frequently leads to collapse of the femoral head and subsequent osteoarthritis of the hip. Joint-preserving procedures are attempted in the early stages without collapse, while total hip arthroplasty (THA) is done during more advanced stages with femoral head collapse or a fracture in the necrotic portion. Thus, accurate staging of the disease is mandatory to decide therapeutic strategy. The purpose of this study is to determine the prevalence of occult fracture in the necrotic portion among osteonecrotic femoral heads, which were classified as Association Research Circulation Osseous (ARCO) stage 1 or 2 on radiographs. MATERIALS AND METHODS: A preoperative computer tomography (CT) scan was routinely performed to obtain an adequate cup position in patients undergoing THA at our institution. Radiographs and CT scans of 308 patients, who underwent unilateral THA due to ONFH from January 2011 to December 2014, were assessed by two orthopedic surgeons to compare the stage based on simple radiography and that based on CT scans. RESULTS: Among the 308 hips, which were classified as stage I or II lesions on simple radiography, fracture inside the necrotic portion was seen in 63 hips (20.5%) on CT scans. Fifty-nine of the 63 patients were followed for two to five years. Further collapse of the femoral head occurred in 41 patients, and 36 of them underwent THA during the follow up. CONCLUSION: In this study, 20.5% of hips classified as ARCO stage I or II on simple radiography were found to be ARCO stage III on CT imaging. When a joint-preserving treatment is considered for early stage ONFH, CT examination is necessary for more precise staging of the disease.


Subject(s)
Arthroplasty, Replacement, Hip , Femur Head Necrosis , Femur Head , Femur Head Necrosis/diagnostic imaging , Humans , Retrospective Studies , Tomography, X-Ray Computed
4.
Clin Orthop Surg ; 11(2): 137-141, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31156763

ABSTRACT

Transtrochanteric curved varus osteotomy (TCVO) and transtrochanteric rotational osteotomy (TRO) are joint-preserving procedures for osteonecrosis of the femoral head. The purpose of this review is to provide up-to-date guidelines for the osteotomies. One retrospective comparison revealed that TCVO has shorter operation time, less bleeding, lower incidence of osteophyte formation, and lower rate of secondary collapse. To obtain successful results of the osteotomy, the patient should be younger than 40 years and should have a body mass index of less than 24 kg/m2. The osteotomy should be performed in early stages of femoral head osteonecrosis before marked collapse of the femoral head. The patient should have a medium-size lesion and an enough viable bone to restore the intact articular surface and subchondral bone in the weight-bearing area.


Subject(s)
Femur Head Necrosis/surgery , Osteotomy/methods , Age Factors , Blood Loss, Surgical/prevention & control , Body Mass Index , Humans , Operative Time , Osteophyte/prevention & control , Postoperative Complications/prevention & control
5.
J Biomed Mater Res A ; 106(5): 1299-1310, 2018 05.
Article in English | MEDLINE | ID: mdl-29316218

ABSTRACT

Nuclear factor of activated T cells (NFAT)-c1 is known as a key regulator in osteoclast differentiation and immune response. This study is a follow-up to our previous study showing the antiresorptive activity of VIVIT, a peptide type NFATc1 inhibitor, using absorbable collagen sponge (ACS). This study aimed to investigate the effective concentration range of local VIVIT that suppresses early excessive osteoclast activation and inflammation induced by high-dose recombinant human bone morphogenetic protein (rhBMP)-2 and concomitantly enhances bone healing in a rat critical-sized calvaria defect model. High-dose rhBMP-2 (40 µg/defect) alone significantly increased in vivo osteoclast activation and expression of the inflammatory cytokines interleukin-1ß and transforming necrosis factor-α on the scaffold at 7 days after surgery. However, rhBMP-2 had no direct effect on osteoclast activation in vitro. Osteoclast activation by rhBMP-2 was significantly suppressed by combined treatment with VIVIT at concentrations of 75 and 150 µM, but not at 15 µM, whereas suppression of inflammation occurred at all doses of VIVIT. Microcomputed tomography at 4 and 8 weeks after implantation revealed that the combination of rhBMP-2 and VIVIT at 75 µM VIVIT led to a greater bone fraction at the initial defect area, compared with rhBMP-2 alone. These findings revealed that local administration of VIVIT at certain concentrations has multiple positive effects that weaken early excessive osteoimmunological responses and enhance bone healing after rhBMP-2 administration. VIVIT has the potential to expand the therapeutic area of high-dose rhBMP-2 therapy to inflammatory bone loss. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1299-1310, 2018.


Subject(s)
Bone Resorption/drug therapy , Inflammation/drug therapy , NFATC Transcription Factors/antagonists & inhibitors , Oligopeptides/therapeutic use , Animals , Bone Morphogenetic Protein 2 , Bone Resorption/complications , Bone and Bones/drug effects , Bone and Bones/pathology , Inflammation/complications , Inflammation/pathology , NFATC Transcription Factors/metabolism , Oligopeptides/pharmacology , Osteoclasts/cytology , Osteoclasts/drug effects , Osteoclasts/metabolism , Osteogenesis/drug effects , Rats, Sprague-Dawley , Recombinant Proteins , Signal Transduction , Transforming Growth Factor beta
6.
J Biomed Mater Res A ; 106(2): 311-320, 2018 02.
Article in English | MEDLINE | ID: mdl-28884512

ABSTRACT

Continuing from our previous study, we hypothesized that combining electrical stimulation (ES) and three-dimensional (3D) culture would be a useful strategy to obtain more bioactive factors in conditioned medium (CM) derived from human mesenchymal stem cells (hMSC). Our aim in this study was to investigate the bone-healing capacity of CM derived from hMSC after 4 days of culture on a collagen sponge-exposed (CM-ES) or unexposed (CM-control; CM-CON) to ES in comparison with that of hMSC implantation. A cytokine assay of both CMs revealed the presence of cytokines, growth factors, and trophic factors. In vitro evaluation of both CMs showed increased cell growth and alkaline phosphatase activity of the hMSC, with little difference between CMs. We investigated the bone-healing effect using two bone disease models: bone defect and inflammatory bone loss. The calvaria defect was implanted with whole CM or 3D-precultured hMSC unexposed to ES. Microcomputed tomography analysis after 4 weeks indicated a twofold greater bone volume in the CM-CON and CM-ES groups than in the hMSC and vehicle groups, though we found no difference between the CM groups. However, CM-ES enhanced the bone healing of interleukin-1-induced bone loss to a level comparable with hMSC, whereas CM-CON did not. These results show that 3D-cultured CM had a greater or similar capacity for bone healing as treatment using hMSC transplantation, and CM-ES was especially effective against inflammatory bone loss. Thus, 3D-cultured CM with or without ES presents an encouraging alternative to MSC-based bone healing. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 311-320, 2018.


Subject(s)
Cell Culture Techniques/methods , Collagen/pharmacology , Culture Media, Conditioned/pharmacology , Mesenchymal Stem Cells/cytology , Skull/pathology , Wound Healing/drug effects , Animals , Bone Regeneration/drug effects , Bone Resorption/pathology , Cytokines/metabolism , Disease Models, Animal , Electric Stimulation , Humans , Inflammation/pathology , Male , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/metabolism , Rats, Sprague-Dawley , Skull/diagnostic imaging , X-Ray Microtomography , Young Adult
7.
Tissue Eng Part A ; 23(23-24): 1343-1360, 2017 12.
Article in English | MEDLINE | ID: mdl-28457207

ABSTRACT

Choice of appropriate biomaterial is a key factor for the success of recombinant human bone morphogenetic protein (rhBMP)-2 therapy. Inspired by osteogenic cell-differentiating and osteoclast-suppressing capabilities of alendronate (ALN), we manufactured a composite type of ALN-loaded collagen sponge (ALN-CS), which controls the early detrimental effect of high-dose rhBMP-2. This study aimed to evaluate ALN-CS as a high-dose rhBMP-2 carrier by investigating its initial biomolecular effect and efficacy on intramembranous ossification at 1, 4, 8, and 24 weeks using a rat calvarial defect model compared with nonloaded CS. The in vitro rhBMP-2 release in the ALN-CS showed a low initial burst and steady release phase during the rest period despite lack of calcium compared with that in CS alone. ALN release showed the same tendency as rhBMP-2 release. In vitro characterization showed that osteoblast differentiation and mineralization of mesenchymal stromal cells were more enhanced with ALN-CS. The ALN-CS-BMP group showed higher expression of bone-forming and -resorbing markers in vivo than the CS-BMP group after the first 7 days, which might be attributable to the relatively large amount of rhBMP-2 remaining. However, osteoclast activation in the ALN-CS-BMP group was significantly reduced compared with the CS-BMP group. Radiological and histological analyses revealed that ALN-CS-BMP promoted early and dense ossification at the initial defect, with 100% greater bone mass, 20% greater bone density, and less fatty marrow tissue than CS-BMP, which continued during the whole healing period. However, CS or ALN-CS alone failed to show complete defect closure even at the 24-week healing interval. Our results demonstrate that ALN-CS has remarkable advantages over CS alone in high-dose BMP-2 delivery, with potent suppression of resorption, early and dense ossification at the target area with less fatty marrow formation, and continuation of bone quality over the long term, which highlights its great clinical potential as a rhBMP carrier for bone regeneration at intramembranous ossification sites.


Subject(s)
Alendronate , Bone Morphogenetic Protein 2 , Calcification, Physiologic/drug effects , Collagen , Osteoblasts , Osteogenesis/drug effects , Skull , Alendronate/chemistry , Alendronate/pharmacology , Animals , Antigens, Differentiation/biosynthesis , Bone Morphogenetic Protein 2/chemistry , Bone Morphogenetic Protein 2/pharmacology , Cell Differentiation/drug effects , Collagen/chemistry , Collagen/pharmacology , Humans , Male , Osteoblasts/metabolism , Osteoblasts/pathology , Rats , Rats, Sprague-Dawley , Skull/injuries , Skull/metabolism , Skull/pathology
8.
Article in English | MEDLINE | ID: mdl-27727104

ABSTRACT

OBJECTIVES: Osteonecrosis of the jaw has been increasing after dentoalveolar surgery in patients treated with an antiresorptive bisphosphonate (BP), especially strong zoledronate (ZA). The pathophysiology underlying why osteonecrosis occurs exclusively in the jaw bone remains unclear. This study investigated skeletal site-specific bone healing during the use of BPs to explore the preferential incidence of osteonecrosis of the jaw bone. STUDY DESIGN: Extraction of mandibular molar and creation of a tibia defect were performed in rats 2 weeks after weekly intravenous injections with the potent ZA and the weaker BP etidronate. Bone healing was evaluated radiographically and histologically 1 and 4 weeks after defect creation. RESULTS: Bone healing at the extracted socket showed that resorption precedes bone formation, while it was the opposite at the tibia defect. ZA use potentially suppressed bone remodeling, which led to impaired healing at the extracted socket but full regeneration of the tibia defect. However, etidronate showed less suppression of bone remodeling and resulted in increased bone formation at the extracted socket and full regeneration of the tibia defect. CONCLUSIONS: These results suggest that skeletal site-dependent differences in the bone healing process underlie BP-related preferential occurrence of osteonecrosis of the jaw bone.


Subject(s)
Bone Density Conservation Agents/pharmacology , Diphosphonates/pharmacology , Etidronic Acid/pharmacology , Imidazoles/pharmacology , Tibia/drug effects , Tooth Socket/drug effects , Wound Healing/drug effects , Animals , Bisphosphonate-Associated Osteonecrosis of the Jaw/pathology , Bone Density/drug effects , Bone Regeneration/drug effects , Female , Random Allocation , Rats , Rats, Sprague-Dawley , Tibia/surgery , Tooth Extraction , X-Ray Microtomography , Zoledronic Acid
9.
Tissue Eng Part A ; 22(9-10): 801-17, 2016 05.
Article in English | MEDLINE | ID: mdl-27098389

ABSTRACT

Sustained release of bone morphogenetic protein (BMP)-2 by heparin-contained biomaterials is advantageous for bone tissue regeneration using low-dose BMP-2. However, its effect with high-dose BMP-2 is still unclear and should be clarified considering the clinical use of a high dose of BMP-2 in spine and oral surgery. This study aimed to evaluate the efficacy of a heparin-conjugated collagen sponge (HCS) with high-dose BMP-2 delivery by investigating in vivo initial osteogenic regulation and bone healing over 12 weeks in comparison with that of an absorbable collagen sponge (ACS). The in vitro BMP-2 release profile in the HCS exhibited a lower burst followed by a sustained release of BMP-2, whereas that of the ACS showed an initial burst phase only. As a result of a lower burst, the HCS-BMP group showed higher expression of bone-forming/resorbing markers and enhanced activation of osteoclasts than the ACS-BMP group within the scaffold of defect after 7 days, which is presumed to be because of retention of relatively higher amounts of BMP-2. However, the surrounding calvariae were less resorbed in the HCS-BMP group, compared with the aggressive resorptive response in the ACS-BMP group. Microcomputed tomography and histology revealed that HCS-BMP guided more effective bone regeneration of central defect over time inducing minor ossification at the defect exterior, whereas ACS-BMP exhibited excessive ossification at the defect exterior. These results showed that HCS-mediated BMP-2 delivery at a high dose has advantages over ACS, including less early resorption of surrounding bone tissue and higher efficacy in compact bone regeneration over a longer period, highlighting a clinical feasibility of this technology.


Subject(s)
Bone Morphogenetic Protein 2 , Bone Resorption/drug therapy , Collagen , Heparin , Osteoclasts/metabolism , Animals , Bone Morphogenetic Protein 2/chemistry , Bone Morphogenetic Protein 2/pharmacokinetics , Bone Morphogenetic Protein 2/pharmacology , Bone Resorption/metabolism , Bone Resorption/pathology , Collagen/chemistry , Collagen/pharmacokinetics , Collagen/pharmacology , Delayed-Action Preparations/chemistry , Delayed-Action Preparations/pharmacokinetics , Delayed-Action Preparations/pharmacology , Heparin/chemistry , Heparin/pharmacokinetics , Heparin/pharmacology , Osteoclasts/pathology , Rats , Rats, Sprague-Dawley
10.
Clin Orthop Surg ; 8(1): 65-70, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26929801

ABSTRACT

BACKGROUND: To evaluate the effect of spondylolisthesis on lumbar lordosis on the OSI (Jackson; Orthopaedic Systems Inc.) frame. Restoration of lumbar lordosis is important for maintaining sagittal balance. Physiologic lumbar lordosis has to be gained by intraoperative prone positioning with a hip extension and posterior instrumentation technique. There are some debates about changing lumbar lordosis on the OSI frame after an intraoperative prone position. We evaluated the effect of spondylolisthesis on lumbar lordosis after an intraoperative prone position. METHODS: Sixty-seven patients, who underwent spinal fusion at the Department of Orthopaedic Surgery of Gwangmyeong Sungae Hospital between May 2007 and February 2012, were included in this study. The study compared lumbar lordosis on preoperative upright, intraoperative prone and postoperative upright lateral X-rays between the simple stenosis (SS) group and spondylolisthesis group. The average age of patients was 67.86 years old. The average preoperative lordosis was 43.5° (± 14.9°), average intraoperative lordosis was 48.8° (± 13.2°), average postoperative lordosis was 46.5° (± 16.1°) and the average change on the frame was 5.3° (± 10.6°). RESULTS: Among all patients, 24 patients were diagnosed with simple spinal stenosis, 43 patients with spondylolisthesis (29 degenerative spondylolisthesis and 14 isthmic spondylolisthesis). Between the SS group and spondylolisthesis group, preoperative lordosis, intraoperative lordosis and postoperative lordosis were significantly larger in the spondylolisthesis group. The ratio of patients with increased lordosis on the OSI frame compared to preoperative lordosis was significantly higher in the spondylolisthesis group. The risk of increased lordosis on frame was significantly higher in the spondylolisthesis group (odds ratio, 3.325; 95% confidence interval, 1.101 to 10.039; p = 0.033). CONCLUSIONS: Intraoperative lumbar lordosis on the OSI frame with a prone position was larger in the SS patients than the spondylolisthesis patients, which also produced a larger postoperative lordosis angle after posterior spinal fusion surgery. An increase in lumbar lordosis on the OSI frame should be considered during posterior spinal fusion surgery, especially in spondylolisthesis patients.


Subject(s)
Intraoperative Care/methods , Lumbar Vertebrae/surgery , Postoperative Complications/prevention & control , Prone Position/physiology , Spinal Stenosis/surgery , Spondylolisthesis/surgery , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Posture/physiology , Retrospective Studies
11.
ScientificWorldJournal ; 2014: 646953, 2014.
Article in English | MEDLINE | ID: mdl-25258730

ABSTRACT

Owing to a paradigm shift toward Internet of Things (IoT), researches into IoT services have been conducted in a wide range of fields. As a major application field of IoT, waste management has become one such issue. The absence of efficient waste management has caused serious environmental problems and cost issues. Therefore, in this paper, an IoT-based smart garbage system (SGS) is proposed to reduce the amount of food waste. In an SGS, battery-based smart garbage bins (SGBs) exchange information with each other using wireless mesh networks, and a router and server collect and analyze the information for service provisioning. Furthermore, the SGS includes various IoT techniques considering user convenience and increases the battery lifetime through two types of energy-efficient operations of the SGBs: stand-alone operation and cooperation-based operation. The proposed SGS had been operated as a pilot project in Gangnam district, Seoul, Republic of Korea, for a one-year period. The experiment showed that the average amount of food waste could be reduced by 33%.


Subject(s)
Food , Garbage , Internet , Waste Management/methods , Algorithms , Geography , Humans , Pilot Projects , Reproducibility of Results , Republic of Korea
12.
Lab Chip ; 7(5): 557-64, 2007 May.
Article in English | MEDLINE | ID: mdl-17476373

ABSTRACT

Valving is critical in microfluidic systems. Among many innovative microvalves used in lab-on-a-chip applications, phase change based microvalves using paraffin wax are particularly attractive for disposable biochip applications because they are simple to implement, cost-effective and biocompatible. However, previously reported paraffin-based valves require embedded microheaters and therefore multi-step operation of many microvalves was a difficult problem. Besides, the operation time was relatively long, 2-10 s. In this paper, we report a unique phase change based microvalve for rapid and versatile operation of multiple microvalves using a single laser diode. The valve is made of nanocomposite materials in which 10 nm-sized iron oxide nanoparticles are dispersed in paraffin wax and used as nanoheaters when excited by laser irradiation. Laser light of relatively weak intensity was able to melt the paraffin wax with the embedded iron oxide nanoparticles, whereas even a very intense laser beam does not melt wax alone. The microvalves are leak-free up to 403.0 +/- 7.6 kPa and the response times to operate both normally closed and normally opened microvalves are less than 0.5 s. Furthermore, a sequential operation of multiple microvalves on a centrifugal microfluidic device using a single laser diode was demonstrated. It showed that the optical control of multiple microvalves is fast, robust, simple to operate, and requires minimal chip space and thus is well suited for fully integrated lab-on-a-chip applications.


Subject(s)
Centrifugation/instrumentation , Centrifugation/methods , Lighting , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Nanostructures/chemistry , Lasers
13.
Lab Chip ; 7(5): 565-73, 2007 May.
Article in English | MEDLINE | ID: mdl-17476374

ABSTRACT

We report a fully integrated, pathogen-specific DNA extraction device utilizing centrifugal microfluidics on a polymer based CD platform. By use of the innovative laser irradiated Ferrowax microvalve (LIFM) together with the rapid cell lysis method using laser irradiation on magnetic particles, we could, for the first time, demonstrate a fully integrated pathogen specific DNA extraction from whole blood on a CD. As a model study, DNA extraction experiments from whole blood spiked with Hepatitis B virus (HBV) and E.coli were conducted. The total process of the plasma separation, mixing with magnetic beads conjugated with target specific antibodies, removal of plasma residual, washing and DNA extraction was finished within 12 min with only one manual step, the loading of 100 microL of whole blood. Real-time PCR results showed that the concentration of DNA prepared on a CD using a portable sample preparation device was as good as those by conventional bench top protocol. It demonstrates that our novel centrifugal microfluidics platform enables a full integration of complex biological reactions that require multi-step fluidic control.


Subject(s)
Centrifugation/instrumentation , Centrifugation/methods , DNA, Bacterial/blood , DNA, Bacterial/isolation & purification , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Escherichia coli/genetics , Escherichia coli/pathogenicity , Humans , Magnetics
14.
Opt Express ; 14(19): 8654-60, 2006 Sep 18.
Article in English | MEDLINE | ID: mdl-19529246

ABSTRACT

The nano-imprint lithography method was employed to incorporate wide-area (375 x 330 mum(2)) photonic-crystal (PC) patterns onto the top surface of GaN-based LEDs. When the 280-nm-thick p-GaN was partly etched to ~140 nm, the maximal extraction-efficiency was observed without deteriorating electrical properties. After epoxy encapsulation, the light output of the PC LED was enhanced by 25% in comparison to the standard LED without pattern, at a standard current of 20 mA. By three-dimensional finite-difference time-domain method, we found that the extraction efficiency of the LED tends to be saturated as the etch-depth in the GaN epitaxial-layer becomes larger than the wavelength of the guided modes.

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