1,351 research outputs found

    Disposable Integrated Microfluidic Biochip for Blood Typing by Plastic Microinjection Moulding

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    Blood typing is the most important test for both transfusion recipients and blood donors. In this paper, a low cost disposable blood typing integrated microfluidic biochip has been designed, fabricated and characterized. In the biochip, flow splitting microchannels, chaotic micromixers, reaction microchambers and detection microfilters are fully integrated. The loaded sample blood can be divided by 2 or 4 equal volumes through the flow splitting microchannel so that one can perform 2 or 4 blood agglutination tests in parallel. For the purpose of obtaining efficient reaction of agglutinogens on red blood cells (RBCs) and agglutinins in serum, we incorporated a serpentine laminating micromixer into the biochip, which combines two chaotic mixing mechanisms of splitting/recombination and chaotic advection. Relatively large area reaction microchambers were also introduced for the sake of keeping the mixture of the sample blood and serum during the reaction time before filtering. The gradually decreasing multi-step detection microfilters were designed in order to effectively filter the reacted agglutinated RBCs, which show the corresponding blood group. To achieve the cost-effectiveness of the microfluidic biochip for disposability, the biochip was realized by the microinjection moulding of COC (cyclic olefin copolymer) and thermal bonding of two injection moulded COC substrates in mass production with a total fabrication time of less than 20 min. Mould inserts of the biochip for the microinjection moulding were fabricated by SU-8 photolithography and the subsequent nickel electroplating process. Human blood groups of A, B and AB have been successfully determined with the naked eye, with 3 mu l of the whole sample bloods, by means of the fabricated biochip within 3 min.X11100104sciescopu

    Transantral Orbital Floor Fracture Repair Using a Folded Silastic Tube

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    ObjectivesThe purpose of this study was to evaluate the advantages and limitations of using a silicon tube to support the fractured orbital floor by a transantral approach.MethodsA retrospective study was conducted from January 2000 to December. 2011 in 51 patients with pure orbital floor fractures. The patients underwent reduction surgery via a transantral approach for inserting a folded silastic tube to support the fractured orbital floor in the maxillary sinus. A chart review of preoperative and postoperative ocular symptoms, operation records, and complications was maintained.ResultsIn 18 out of 25 patients with diplopia, postoperative improvement was seen. In 13 out of 15 patients with extraocular muscle limitation, postoperative improvement was seen. Enophthalmos resolved postoperatively in four of five patients. Postsurgical complications occurred in three patients: an overcorrection, an infection in the maxillary sinus, and an implant extrusion, all of which were resolved by revision surgeries.ConclusionDuring the course of the study, we sensed reduction using a folded silastic tube via a transantral approach as an easy and effective technique with good postoperative results, and minimal implant related complications. This novel procedure is recommended as a surgical option for the reduction of orbital floor fractures

    Ruthenium Bottom Electrode Prepared by Electroplating for a High-density DRAM Capacitor

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    The possibility of Ru electroplating for application as the bottom electrode in high density dynamic random access memory ~DRAM! capacitors was investigated. Prior to Ru electroplating on a TiN substrate, HF cleaning and Pd activation were performed. Removal of Ti oxide from the TiN substrate by HF treatment enabled Pd activation, which enhanced the nucleation of Ru on TiN substrate. Optimized pretreatments led to a continuous Ru film deposition. The surface roughness was measured to be 4.4 nm at 45 nm Ru film on the bare substrate. Moreover Ru electroplating method was also applied to a capacitor node-type TiN wafer. The deposition rate of Ru on the patterned wafer was the same as that on a bare wafer. The film showed 93% step coverage and good adhesion, comparable to CVD Ru films

    Bone quality and growth characteristics of growth plates following limb transplantation between animals of different ages - Results of an experimental study in male syngeneic rats

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    <p>Abstract</p> <p>Introduction</p> <p>The purpose of this study was to identify graft osteoporosis post transplantation by micro-CT analysis, and the growth potential of growth plates in the transplanted limb.</p> <p>Methods</p> <p>Ten juvenile to juvenile and five juvenile to adult hind limb transplants were performed in male syngeneic Lewis rats. Upper tibial bone density in isochronograft and heterochronograft limbs was measured by 3D micro-CT and compared with that of the opposite non-operated limbs.</p> <p>Results</p> <p>We observed inferior bone quality (p < 0.05) in heterochronografts compared to isochronografts. After transplantation, isochronografts did not exhibit increases in tibial lengths compared to opposite juvenile non-operated tibias (p = 0.66) or heterochronograft tibias (p = 0.61). However, significant differences were observed between heterochrongraft tibial lengths when and opposite adult non operated tibial lengths (p < 0.001).</p> <p>Conclusions</p> <p>Age dependent alterations affect bone quality, resulting in post transplantation osteoporosis in heterochronografts, but not isochronografts. However, the growth plates of transplanted limbs retain their properties of longitudinal growth and continue to grow at the same rate.</p

    Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation

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    Background: Titanium dioxide (TiO2) has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25-70) together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25-70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein, Bax. Elucidating the molecular mechanisms by which nanosized particles induce activation of cell death signaling pathways would be critical for the development of prevention strategies to minimize the cytotoxicity of nanomaterials.This work was supported by the Korea Ministry of Environment and The Eco-Technopia 21 Project (091-091-081)

    Enhancement of seawater corrosion resistance in copper using acetone-derived graphene coating

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    We show that acetone-derived graphene coating can effectively enhance the corrosion efficiency of copper (Cu) in a seawater environment (0.5-0.6 M (???3.0-3.5%) sodium chloride). By applying a drop of acetone (???20 ??l cm-2) on Cu surfaces, rapid thermal annealing allows the facile and rapid synthesis of graphene films on Cu surfaces with a monolayer coverage of almost close to ???100%. Under optimal growth conditions, acetone-derived graphene is found to have a relatively high crystallinity, comparable to common graphene grown by chemical vapor deposition. The resulting graphene-coated Cu surface exhibits 37.5 times higher corrosion resistance as compared to that of mechanically polished Cu. Further, investigation on the role of graphene coating on Cu surfaces suggests that the outstanding corrosion inhibition efficiency (IE) of 97.4% is obtained by protecting the underlying Cu against the penetration of both dissolved oxygen and chlorine ions, thanks to the closely spaced atomic structure of the graphene sheets. The increase of graphene coating thickness results in the enhancement of the overall corrosion IE up to ???99%, which can be attributed to the effective blocking of the ionic diffusion process via grain boundaries. Overall, our results suggest that the acetone-derived graphene film can effectively serve as a corrosion-inhibiting coating in the seawater level and that it may have a promising role to play for potential offshore coating.close0

    Assessing Feasibility and Safety of Using Ultrasonic Bone Aspirator for Revision Endoscopic Sinus Surgery

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    Background and Objectives This study introduced and evaluated the efficacy of an ultrasonic bony aspirator (UBA) in revision endoscopic sinus surgery and compared the outcomes to those of the traditional cold instrument approach. Methods This retrospective study enrolled 57 patients who underwent revision endoscopic sinus surgery between June 2010 and December 2017, 17 patients with a UBA approach and 40 patients with traditional instruments. Results Median Lund–Kennedy scores showed a statistically significant difference between the two groups at 3 months (p=0.004). Synechiae occurred in 17.6% and 35% of cases in the UBA and traditional groups, respectively. The mean operative time was significantly shorter in the traditional group (p=0.001). Conclusion The use of a UBA in revision endoscopic sinus surgery was safe and effective

    Juvenile Paget's Disease with Paranasal Sinus Aplasia

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    Juvenile Paget's disease (JPD) is a rare skeletal disorder that's characterized by bone demineralization and elevated levels of serum alkaline phosphatase. JPD involves the paranasal sinuses in extremely rare cases. We report here on a 25-month-old Asian male who was diagnosed of JPD associated with aplasia of the paranasal sinuses, but not the ethmoid sinuses. The patient was successfully treated by surgery and we undertook no medical intervention. This appears to be the first reported case of JPD associated with bilateral paranasal sinus aplasia

    Reperfusion Injury after Autologous Cranioplasty in a Patient with Sinking Skin Flap Syndrome

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    The sinking skin flap syndrome is a rare complication after a large craniectomy. It consists of a sunken skin above the bone defect with neurological symptoms such as severe headache, mental changes, focal deficits, or seizures. In patient with sinking skin flap syndrome, cerebral blood flow and cerebral metabolism are decreased by sinking skin flap syndrome, and it may cause the deterioration of autoregulation of brain. We report a case of a patient with sinking skin flap syndrome who suffered from reperfusion injury after cranioplasty with review of pertinent literature
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