• Journal of the Korean Society for Library and Information Science
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• v.38 no.1
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• pp.13-34
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• 2004

The Reference Model for an Open Archival Information system(OAIS) was recommended for developing digital archives effectively and for implementing interoperability and resource sharing between digital archives. But as the Reference Model is high-level recommendation, it does not specify a design and an implementation. Therefore, this study investigates the architecture of several digital archives, suggestes three strategies for persistent archive, and proposes the conceptual model for developing trusted, persistent, and secure digital archive.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.523-528
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• 2001

The persistent infection of avian pneumovirus (APV) was studied in turkeys. After APV infection to turkeys, healthy birds were transferred to infected birds and commingled at 4 days, 3 weeks, 6 weeks, 9 weeks, and 15 weeks post-infection. The genome of APV was detected up to 10 days from two birds transferred and commingled with infected birds at 3 weeks post-infection. A bird transferred at 6 weeks post-infection was positive in RT-PCR detection after 5 days. From then on, no bird showed positive results of persistency of APV infection. These findings suggest that persistent APV infection may spread to the healthy birds from the infected birds until several weeks.

• Investigative Magnetic Resonance Imaging
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• v.10 no.2
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• pp.117-120
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• 2006

Atretic cephalocelces are defined as skin-covered midline subscalp lesions that contain meninges and rest of glial and/or central nervous system tissue. When the straight sinus is absent or rudimentary, the falcine sinus can be recanalized to enable venous drainage. Although the atretic cephalocele or persistent falcine sinus has largely been described in the pediatric population, it is a rarely observed in the adult population. We report a unique case of spontaneously involuted atretic cephalocele coexistent with persistent falcine sinus in an adult. MR images and MR venography were useful for diagnosis and accurate anatomical depiction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1208-1220
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• 1996

In this paper, the performance of a Carrier Sense Multiple Access/Collision avoidance (CSMA/CA) protocol using stop-and-Wait automatic Repeat reQuest, which is adapted as a draft standard in IEEE 802.11, is analyzed using a mathematical method based on a renewal theory, and simulation checks are performed, which confirm the goodness of our anlysis. In order to anlayze of CSMA/CA, we model that network is composed of finite populationand channel is slotted. And, we consider the CSMA/CA protocol as a hybrid protocol of 1-persistent CSMA and p-persistent CSMA protocol. As resuls of analysis, we have found that the throughput is degraded and packet delay is increased as the number of stations, Acknowledgement (ACK) length and Distributed coordination function Inter Frame Space (DIFS) length are increased.

• Molecules and Cells
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• v.37 no.7
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• pp.518-525
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• 2014

Gammaherpesvirus (${\gamma}HV$) infection of the central nervous system (CNS) has been implicated in diverse neurological diseases, and murine ${\gamma}HV$-68 (MHV-68) is known to persist in the brain after cerebral infection. The underlying molecular mechanisms of persistency of virus in the brain are poorly understood. Here, we characterized a unique pattern of MHV-68 persistent infection in neuroblastoma cells. On infection with MHV-68, both murine and human neuroblastoma cells expressed viral lytic proteins and produced virions. However, the infected cells survived productive infection and could be cultured for multiple passages without affecting their cellular growth. Latent infection as well as productive replication was established in these prolonged cultures, and lytic replication was further increased by treatment with lytic inducers. Our results provide a novel system to study persistent infection of ${\gamma}HVs$ in vitro following de novo infection and suggest application of MHV-68 as a potential gene transfer vector to the brain.

• Progress in Superconductivity and Cryogenics
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• v.15 no.4
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• pp.44-47
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• 2013

We had proposed a winding method so called "Wind-and-Flip", which enables a persistent current operation of an HTS pancake coil without any electrical joint. In order to improve the magnetic field drift characteristics, a prototype HTS coil with the technique was fabricated, and tested under various temperatures. Because the coil doesn't have any electric terminals for current leads, an HTS background magnet was used to induce the persistent current in the coil by field cooling process. A conduction cooling system with a GM cryocooler was prepared to keep the operating temperatures of the prototype coil much below the 77 K. We investigated the magnetic field drift characteristics under the various operating temperatures by measuring the center magnetic field with a cryogenic Hall sensor. The persistent current mode operation at 20 ~ 50K showed a strong possibility of the winding technique for the application such as MRI or NMR.

• Journal of Korean Academy of Nursing
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• v.50 no.2
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• pp.159-177
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• 2020

Purpose: This study aimed at identifying factors related to persistent postoperative pain after cardiac surgery and estimating their effect sizes. Methods: The literature search and selection was conducted in four different databases (CINAHL, Cochrane Library, PubMed, and PQDT) using the Preferred Reporting Items for Systematic Review and Meta-Analysis Statement. A total of 14 studies met the inclusion criteria and were systematically reviewed. For the meta-analysis, R was used to analyze 30 effect sizes of for both individual and operative factors as well as publication biases from a total of nine studies. Results: The meta-analysis revealed that persistent postoperative pain after cardiac surgery was related to one individual factor (gender) and two operative factors (acute postoperative pain and use of the internal mammary artery). Operative factors (OR=5.26) had a larger effect size than individual factors (OR=1.53). Conclusion: Female gender, acute pain after surgery, and use of the internal mammary artery are related factors to persistent postoperative pain. The development of interventions focusing on modifiable related factors, such as acute postoperative pain, may help to minimize or prevent PPP after cardiac surgery.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.163-167
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• 2007

Bovine viral diarrhea (BVD) is very important disease in cattle industry with a worldwide distribution. Detection and elimination of persistently infected calves with bovine viral diarrhea virus (BVDV) was valuable strategy for BVD eradication because those calves were main source for transmission. We surveyed persistent infection with BVDV by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) using whole blood and skin. Five hundred thirty nine Korean native calves were tested. Four calves (0.7%) were positive for BVDV antigen for both tests. Those calves remained positive for follow-up by RT-PCR and IHC. Therefore they were identified as persistently infected with BVDV. We confirmed that immunohistochemistry using skin biopsy samples was very useful tool to detect persistently infected calves with BVDV. As far as we know, this would be first report on persistent infection with BVDV in Korea.

• Korean Journal of Materials Research
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• v.30 no.8
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• pp.413-420
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• 2020

Lu₃Al_5-xGa_xO₁₂:Ce³⁺,Cr³⁺ powders are prepared using a solid-state reaction method. To determine the crystal structure, Rietveld refinement is performed. The results indicate that Ga³⁺ ions preferentially occupied tetrahedral rather than octahedral sites. The lattice constant linearly increases, obeying Vegard's law, despite the strong preference of Ga³⁺ for the tetrahedral sites. Increasing x led to a blue-shift of the Ce³⁺ emission band in the green region and a change in the emission intensity. Persistent luminescence is observed from the powders prepared with x = 2-3, occurring through a trapping and detrapping process between Ce³⁺ and Cr³⁺ ions. The longest persistent luminescence is achieved for x = 2; its lifetime is at least 30 min. The findings are explained using crystal structure refinement, crystal field splitting, optical band gap, and electron trapping mechanism.

• Journal of Veterinary Clinics
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• v.35 no.1
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• pp.26-29
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• 2018

A 6-month-old, female poodle presented with a three-month history of persistent regurgitation immediately after eating. On physical examination, the patient was emaciated and dehydrated. Thoracic radiography showed ventral displacement of the trachea and increased radiopacity in the mediastinum, cranial to the heart base. A severely dilated esophagus was identified cranial to the heart on esophagram. Computed tomography (CT) revealed the esophagus was filled with gas, fluid and a little of contrast and dilated from caudo-cervical to cranio-thoracic part. The esophageal diameter was markedly decreased at the heart base. In addition, the trachea was displaced to the left-ventral side of the right aortic trunk and an aberrant left subclavian artery originating from the aorta was identified. There was no evidence of abdominal vascular anomaly. Based on diagnostic imaging, persistent right aortic arch (PRAA) with an aberrant left subclavian artery was diagnosed. The patient did not undergo surgery and died at 15 days after diagnosis. This report describes imaging diagnosis, including CT and radiography in a weaned dog with regurgitation due to esophageal obstruction by PRAA. When PRAA is suspected and conventional radiography or contrast study is insufficient for diagnosis, CT may be helpful for diagnosing PRAA.