• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1253-1255
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• 1993

Double Injection(DI) switching devices consist of p+ and n+ contact separated by a nearly intrinsic semiconductor region containing deep trap. The FEM is chosen as a simulation method for DI switching device, because of the advantage in local mesh refinement and computer memory comparing with other methods. And Scharfetter-Gummel(S-G) scheme is applied, with which an accurate-seven point Gaussian Quadrature rule is combined. The existance of deed trap requires the modification of conventional equation set. So recombination rate equation is modified and a new equation is included in the equation set which conventionally consists of Poisson equation and current continuity equations.

• Journal of Korean Neurosurgical Society
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• v.29 no.3
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• pp.420-425
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• 2000

Epidural steroid injection(ESI) has been a commonly applied conservative therapy for the management of chronic low back pain and sciatica. However, there are many reports concerning various local, systemic and neurological complications related to ESI. We report two cases with fatal complications after ESI for low back pain and sciatica. In both patients, ventriculitis and meningitis were causative factors to be fatal. Aseptic procedures and careful post-procedure assessment are essential to avoid serious complications following ESI.

• Journal of Korean Neurosurgical Society
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• v.55 no.3
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• pp.167-169
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• 2014

Giant cell tumor (GCT) of the spine is a rare benign tumor, but can be aggressive and can exhibit a high local recurrence rate. Furthermore, GCT of the upper thoracic spine may pose diagnostic and management difficulties. Here, we report a rare case of GCT of the upper thoracic spine with soft tissue extension to the spinal canal. The patient was managed by decompressive laminectomy and posterolateral fusion followed by an injection of polymethylmethacrylate into the vertebral lesion. The patient recovered clinically and showed radiological improvement after surgical treatment without tumor recurrence at his last follow-up of postoperative 7 years. We present this unusual case of GCT and include a review of the literature.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.307-313
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• 2019

In order to design efficient Urea Decomposition Chamber (UDC) for the Low Pressure (LP) Selective Catalytic Reduction (SCR) system, numerical simulations were conducted with respect to various design parameters. The design parameters examined in this simulation include the chamber diameter, inlet and outlet shape of chamber, and urea injection point. Reaction kinetics for the urea decomposition was proposed and validated with the experimental data in the range of $300{\sim}450^{\circ}C$. The effects of design parameters on the performance of UDC were evaluated by the calculated urea conversion and pressure drop. As a result, the local optimum design values were derived by the parametric study.

• Brain Tumor Research and Treatment
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• v.6 no.2
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• pp.68-72
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• 2018

We report a rare case of arachnoid granulations mimicking multiple osteolytic bone lesions. A 66-year-old woman was admitted to a local clinic for a regular checkup. Upon admission, brain CT showed multiple osteolytic lesions in the occipital bone. These needed to be differentiated from multiple osteolytic bone tumor. Subsequent brain MRI revealed that the osteolytic lesions were isointense to cerebrospinal fluid, hyperintense on T2-weighted image, hypointense on T1-weighted image, and with subtle capsules around the osteolytic lesions that were visible after gadolinium injection. A bone scan revealed no radiotracer uptake. The lesions were in both the transverse sinuses and the torcular herophili. With typical radiological appearances of the lesions, the osteolytic lesions were diagnosed as multiple arachnoid granulations. No further treatment was planned. A 1-year follow-up brain CT scan revealed no change. We should consider the possibility of arachnoid granulations when multiple osteolytic lesions are observed in the occipital bone.

• Oral Biology Research
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• v.42 no.4
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• pp.241-247
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• 2018

Toothache is one of the most common discomforts experienced by patients in dental clinic. If clinical and radiographic examinations do not reveal any pathologic findings, we can suspect nonodontogenic toothache. Nonodontogenic toothache can be caused by a variety of causes such as muscle disorders, sinus and nasal mucosal problems, neuropathic pain, neurovascular pain, psychogenic problems, and cardiogenic disease. A thorough history and clinical examination should be performed to confirm the cause of the pain, and more accurate diagnosis can be established through local anesthetic injection. If the nonodontogenic toothache is misdiagnosed, unnecessary dental treatment such as root canal treatment, periodontal treatment, and extraction can be performed, and the patient's pain is not alleviated through such treatment. Therefore, the cause of toothache must be diagnosed correctly before dental treatment is performed, and clinicians should be fully aware of the diseases that may cause these symptoms.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.180-185
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• 2022

Objective : Drug-eluting stents and balloons are occasionally used to reduce restenosis in medically intractable intracranial atherosclerotic stenosis. The authors aimed to determine whether such drugs can cause neurotoxicity due to local effects in a rat model. Methods : Intra-arterial catheters were placed in the right common carotid artery of rats. Mannitol was injected to transiently open the brain-blood barrier (BBB), followed by high-dose drug (paclitaxel and rapamycin) injection. The optimal time interval of transient BBB opening for maximal drug penetration was determined to be 10 minutes. Paclitaxel and rapamycin were intra-arterially administered in various doses. All the rats were neurologically evaluated, and their brain tissues were histologically examined. Results : Neither neurological deficits nor histological abnormalities were observed in all the rats. Conclusion : Paclitaxel and rapamycin did not cause neurotoxicity in a rat model with transient BBB opening.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.16-26
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• 2023

Diabetes is an untreatable metabolic disorder characterized by alteration in blood sugar homeostasis, with submucosal insulin therapy being the primary treatment option. This route of drug administration is attributed to low patient comfort due to the risk of pain, distress, and local inflammation/infections. Nanoparticles have indeed been suggested as insulin carriers to allow the drug to be administered via less invasive routes other than injection, such as orally or nasally. The organic-based nanoparticles can be derived from various organic materials (for instance, polysaccharides, lipids, and so on) and thus are prevalently used to enhance the physical and chemical consistency of loaded bioactive compounds (drug) and thus their bioavailability. This review presents various forms of organic nanoparticles (for example, chitosan, dextron, gums, nanoemulsion, alginate, and so on) for enhanced hypoglycemic drug delivery relative to traditional therapies.

• Journal of Dental Anesthesia and Pain Medicine
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• v.24 no.4
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• pp.265-272
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• 2024

Effective pain management is crucial for the successful performance of various endodontic procedures. Painless treatments are made possible by anesthetizing the tooth to be treated using various nerve-block techniques. However, certain circumstances necessitate supplemental anesthetic techniques to achieve profound anesthesia, especially in situations involving a "hot tooth" in which intrapulpal anesthesia (IPA) is employed. IPA is a technique that involves the injection of an anesthetic solution directly into the pulp tissue and is often utilized as the last resort when all other anesthetic techniques have been unsuccessful in achieving complete pulpal anesthesia. This review focuses on the IPA procedure and the factors that influence its success. Additionally, the advantages, limitations, disadvantages, and future directions of IPA are discussed.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.2
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• pp.136-140
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• 2009

Background and Objectives: Recurrent respiratory papillomatosis (RRP) is difficult to treat because of its tendency to recur and spread throughout the aerodigestive tract. We aimed to estimate the effect of intralesional injections of cidofovir in patients with RRP. Materials and Method: Within the period from January 2003 to July 2007, 13 patients aged 2 to 61 years were treated with intralesional injections of cidofovir combined with surgical excision of RRP. Cidofovir was injected intralesionaly at a concentration of 5 mg/cc after complete removal of the papilloma with $CO_2$ laser or microdebrider. We evaluated the effect of intralesional cidofovir therapy by comparing pre-treatment mean interval of recurrence with post-treatment interval of recurrence. Results: Of 13 patients, two patients showed complete response during follow up period and four patients showed partial response. Seven patients did not respond to cidofovir at all. Mean pre-treatment mean interval of recurrence was 9 months and mean post-treatment interval of recurrence was 13.1 months (p=0.039). There was a statistical significance between the injected dose of cidofovir and post-treatment interval of recurrence (p=0.009). There were no local or systemic side effects caused by cidofovir. Conculsion : Intralesional injection of cidofovir seems to have a potential of a safe and effective adjuvant therapy of RRP. There was a positive correlation between the injected dose of cidofovir and patient clinical outcomes so that administration of higher doses and more frequency of injections should be needed to reduce recurrence. Further study regarding injection therapy regimen for RRP is required.