• Advances in nano research
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• v.17 no.1
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• pp.87-94
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• 2024

Nanotechnology is one of the leading edges of science and technology today, holding out the promise for revolutionary advances in just about any discipline. With the integration of nanoscale concepts into K-12 STEM education comes a special opportunity pertaining to the cultivation of future innovators and scientists who are more adept at traveling in this burgeoning field. It discusses some strategies and frameworks for effectively bringing nanotechnology into the K-12 curriculum. Hands-on activities, interdisciplinary approaches, and age-appropriate educational materials have been used with an emphasis on improving student engagement and enhancing understanding in nanoscale phenomena. Thus, early exposure to the principles of nanotechnology can be effectively used by teachers to develop curiosity, critical thinking, and problem-solving skills, which are necessary for technological advancement. These results highlight the potential of nanotechnology education integration in the development of future STEM professionals. It results in an increase in the enrollment rate. Hence, this proves that there is a lasting impact of the intervention on the choice that students made while in school.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.947-954
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• 2009

This paper proposed a new balanced power amplifier using the reflected input of conventional balanced power amplifiers composed of branch line hybrid coupler. In general, the single-ended amplifier in balanced amplifiers does not have the perfect matching, so the reflected input power, in other words the leakage power, is terminated conventionally at the isolation port of hybrid coupler. However in this work, the leakage power is injected into the auxiliary amplifier, and its output power is combined to the output power of balanced amplifier. Therefore output power, efficiency, and 2-tone IMD3 performances of the proposed balanced amplifier are highly improved compared to the conventional balanced amplifier. For the verification of the proposed balanced amplifier, a conventional balanced amplifier and the proposed balanced amplifier are designed, fabricated and measured, and the measured results are compared. The proposed balanced amplifier shows the improvement in the output power(Pout), power added efficiency (PAE), and 2-tone IMD3 by 3dB, 5.2%, and $5{\sim}10dBc$, respectively, from the measurement.

• Mycobiology
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• v.45 no.1
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• pp.15-19
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• 2017

This study proposed a rapid method to quantify the colonization rate of arbuscular mycorrhizal fungi (AMF) in plant roots. The method involved the use of an image analysis software (WinRHIZO Pro). The colonization rate is defined as the ratio of the fungal body to the plant root area in a micrograph. Three seedlings of Chengiopanax sciadophylloides, a woody species that accumulates radiocesium, were collected from a secondary forest in the Yamakiya district of Kawamata, Fukushima Prefecture during May-September 2014. The colonization of AMF structures was examined under a light microscope, and the percentage of colonization was determined using the WinRHIZO method. The superiority of the new method was verified by comparing with a modified grid-line intersect method. The colonization of AMF was confirmed in all the seedlings, and a significant coefficient of determination ($R^2=0.94$) was found with both the methods. The results suggested that the WinRHIZO method is reliable for estimating the colonization of AMF in C. sciadophylloides.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.2
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• pp.132-135
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• 2019

Spasmodic dysphonia is a focal laryngeal dystonia that results in involuntary spasms during speech. The etiology of spasmodic dysphonia is not yet defined, but it is presumed to be a neurological abnormality of central nervous system motor function. The treatment of choice for spasmodic dysphonia is botulinum toxin injection directly at the laryngeal muscles. However botulinum toxin injection requires repeated procedures. Many different kinds of surgical treatments have been introduced but the recurrence rate is still high. So we performed myomectomy with LASER and neurectomy with specially designed electrical surgical knife which can cut recurrent laryngeal nerve branch selectively with its noble curved section. We report a case of a 43-year-old male patient with spasmodic dysphonia treated by thyroarytenoid myoneurectomy.

• Journal of Korean Neurosurgical Society
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• v.42 no.5
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• pp.413-415
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• 2007

A 26-year-old man was admitted to our department due to intermittent left hemiparesis for 3 months. Magnetic resonance Image showed subacute infarction in the right precentral gyrus. Digital subtraction angiography and magnetic resonance angiography revealed an aneurysmal protrusion at the right middle cerebral artery (MCA) bifurcation. It was difficult to differentiate the aneurysm from the occlusion of the middle trunk of the MCA trifurcation. Brain single photon emission computerized tomography showed a decrease in perfusion in the right posterior frontal lobe without vascular reserve. Therefore, we planned a superficial temporal artery MCA anastomosis with an exploration of the right MCA bifurcation. Intraoperatively, the aneurysmal opacification on preoperative angiography proved to be the proximal stump of the occluded middle trunk of the MCA trifurcation. An aneurysmal protrusion at the MCA bifurcation does not always indicate an aneurysm. In diagnosing protruding vascular lesions at the MCA bifurcation, the possibility of a vascular stump should be considered according to their angioanatomical appearance and the history of the patient.

• Journal of Korean Neurosurgical Society
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• v.51 no.2
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• pp.91-93
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• 2012

Acute spontaneous subdural hematoma (SDH) of arterial origin is very rare. We report a case of acute spontaneous SDH that showed contrast media extravasation from cortical artery on angiograms. A 58-year-old male patient developed sudden onset headache and right hemiparesis. Brain CT scan demonstrated acute SDH at left convexity. The patient was drowsy mentality on admission. He had no history of head trauma. Cerebral angiography was performed and revealed a localized extravasation of the contrast media from distal cortical MCA branch. After angiography, the patient deteriorated to comatose mentality. Decompressive craniectomy for removal of SDH was performed. We verified the arterial origin of the bleeding and coagulated the bleeding focus. The histological diagnosis was aneurysmal artery. He recovered after surgery with mild disability. In a case of acute spontaneous SDH, the possibility of a cortical artery origin should be considered.

• Archives of Craniofacial Surgery
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• v.21 no.4
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• pp.244-248
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• 2020

The infraorbital nerve is a branch of the trigeminal nerve. Injury to the infraorbital nerve can be caused by trauma, including various facial fractures. Due to this nerve injury, patients complain of numbness and pain in the entire cheek, the ala of nose, and upper lip. In general, spontaneous sensory recovery is expected after decompressive surgery. If nerve transection is confirmed, however, neurorrhaphy is typically performed. Here, we present a case in which microsurgery was not performed in a patient with Sunderland grade V avulsion injury of the infraorbital nerve due to a facial bone fracture. Gradual nerve function recovery was confirmed to be possible with conservative treatment and rehabilitation alone. These findings suggest that the nerve function recovery can be expected with conservative treatment, even for severe nerve injury for which microsurgery cannot be considered.

• Journal of the Korean Institute of Rural Architecture
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• v.1 no.3
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• pp.97-108
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• 1999

A decrease in population in a rural region have raised a problem that small-scale schools got to be a branch school or abolished. Consequently, a function as a leading role in a community also have declined. Also residential districts of the outer of cities' development have increased for the change of residential environment consciousness. According to peoples who live in CBD move to residential districts of the outer of cities have been become devoid of substance. For this reason, the number of students in urban primary schools has declined more and more, and a number of unused classrooms came out, automatically. This study is to survey the utilization of unused classrooms in urban and rural primary schools in order to proffer basic data to new improvement methods of school facilities planning and to contribute a effect that induce parents of students and residents to use the facilities actively.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.93-98
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• 2009

Stephania delavayi Diels. has been used as an immune activator or an anti-inflammatory drug in China. We examined the immune modulation effect and 7-days repeated-dose toxicity to validate its biological safety and efficiency. Mice were repeatedly administrated with 50 mg/kg S. delavayi Diels. daily by I.P for 7 days. S. delavayi Diels. induced B cell activation but had no effect on other immune cells such as T cell, natural killer (NK) cell, and macrophage ($M{\varphi}$). S. delavayi Diels.-treated group exhibited no statistical significance from the control group in physical conditions; body weight, complete blood count (CBC), serum biochemical indexes etc. There was no difference between the control group and S. delavayi Diels.-treated group in gross findings such as histopathological alteration. In conclusion, S. delavayi Diels. is safe above the dose of immune modulation.

• Smart Structures and Systems
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• v.13 no.6
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• pp.1041-1063
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• 2014

This work introduces a two-module robotic pipe inspection system with ultrasonic NDE device to evaluate the integrity of pipe structures. The proposed robotic platform has high mobility. The two module mobile robot platform overcomes pipe obstacle structures such as elbow, or T-branch joints by cooperative maneuvers. Also, it can climb up the straight pipeline at a fast speed due to the wheel driven mechanism. For inspection of pipe structure, SH-waves generated by EMAT are applied with additional signal processing methods. A wavelet transform is implemented to extract a meaningful and specific signal from the superposed SH-wave signals. Intensity ratio which is normalized the defect signals intensity by the maximum intensity of directly transmitted signals in the wavelet transforms spectrum is applied to evaluate defects quantitatively. It is experimentally verified that the robotic ultrasonic inspection system with EMAT is capable of non-destructive inspection and evaluation of defects in pipe structure successfully by applying signal processing method based on wavelet transform.