• Korean Journal of Materials Research
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• v.31 no.6
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• pp.345-352
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• 2021

In this study, Ni nanoparticle supported by graphene oxide (GO) (Ni-GO) is successfully synthesized through hydrothermal synthesis and calcination, and Cr(VI) is extracted from aqueous solution. The morphology and structure of Ni-GO composites are characterized by scanning electron microscopy (SEM), trans mission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). High-resolution transmission electron microscopy (HRTEM) and XRD confirms the high dispersion of Ni nanoparticle after support by GO. Loading Ni on GO can obviously enhance the stability of Ni-GO composites. It can be calculated from TGA that the mass percentage of Ni is about 60.67 %. The effects of initial pH and reaction time on Cr(VI) removal ability of Ni-GO are investigated. The results indicate that the removal efficiency of Cr(VI) is greater than that of bared GO. Ni-GO shows fast removal capacity for Cr(VI) (<25 min) with high removal efficiency. Dynamic experiments show that the removal process conforms to the quasi-second order model of adsorption, which indicates that the rate control step of the removal process is chemical adsorption. The removal capacity increases with the increase of temperature, indicating that the reaction of Cr(VI) on Ni-GO composites is endothermic and spontaneous. Combined with tests and characterization, the mechanism of Cr(VI) removal by rapidly adsorption on the surface of Ni-GO and reduction by Ni nanoparticle is investigated. The above results show that Ni-GO can be used as a potential remediation agent for Cr(VI)-contaminated groundwater.

• The Journal of Internal Korean Medicine
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• v.44 no.5
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• pp.957-967
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• 2023

Background: According to Vaccine Adverse Events Reporting System data, generalized edema followed by the COVID-19 vaccine is uncommon, with only 333 reported cases, and of those, 224 (69%) are associated with the Pfizer-BioNTech vaccine. Case report: A 76-year-old male patient with heart failure with preserved ejection fraction presented with spontaneous generalized edema and otherwise normal cardiac exams following administration of BNT162b2 (Pfizer-BioNTech) COVID-19 vaccination that had lasted for approximately 60 days and was treated successfully using Korean medicine treatment. After the administration of Korean medicine treatment, the patient's symptoms in the bilateral limbs were dramatically controlled, without recurrence, for 2 months. As a result, generalized edema, which had been present for approximately 50 days, dramatically improved. Conclusion: This clinical case study suggests that a Korean medicine approach with Mokbangki-tang and Oryeong-san might be effective for the pleural effusion resolution of generalized edema after COVID-19 vaccination.

• Clinical and Experimental Pediatrics
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• v.52 no.8
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• pp.917-921
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• 2009

Purpose : Although renal ultrasonography (USG) has improved the detection rate of hydronephrosis (HN), its clinical courses and postnatal management remains controversial. Here, we reviewed the clinical features of patients with HN according to the grades. Methods : We retrospectively studied 207 patients who were regularly followed-up among 367 patients with HN detected by renal USG postnatally between April 1998 and December 2007. These patients were grouped into four groups, grades 1-4, according to renal pelvic diameter (RPD). For analysis, each group was merged into two categories (mild: grade 1, 2; severe: grade 3, 4). Results : During follow-up, 128 episodes of urinary tract infection (UTI) occurred in 91 patients. According to grades from 1 to 4, 35/89 (39.3%), 41/88 (46.5%), 11/22 (50%), and 4/8 (50%), respectively, had UTI, without any significance between the mild and severe groups. However, the severe group presented a higher risk in cumulative episodes of UTI per year (P=0.041). The spontaneous resolution of HN was observed in 103 (58.8%) of the 175 mild group patients and in 3 (10.7%) of the 28 severe group patients (P<0.001). Furthermore, the detection rate of prenatal HN by prenatal USG was much higher in patients with severe RPD (P<0.001). Conclusion : We found that the severer the grade of HN, the lower was the rate of spontaneous resolution and higher was the frequency of UTI. Therefore, the establishment of guidelines for managing treatments such as antibiotic prophylaxis for patients with HN is needed to improve renal prognosis.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.13 no.2
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• pp.128-133
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• 2010

Purpose: Intussusception is one of the most common causes of an acute abdomen in infancy. The majority of pediatric cases of intussusception are of the ileocolic type and usually idiopathic. Small bowel intussusception is rarely diagnosed in children, and few cases have been reported. The purpose of this study was to determine the clinical features and causes of small bowel intussusception in children. Methods: We retrospectively reviewed the clinical and radiologic findings of 21 children with small bowel intussusception who were admitted to Seoul National University Children's Hospital between March 2005 and January 2010. Results: The clinical presentation of small bowel intussusception included abdominal pain or irritability (85%), vomiting (23%), fever (14%), bloody stools (14%), and abdominal masses (4%). Six patients required surgical management. Ultrasonography showed that the mean diameter of the lesions and mean thickness of the outer rims were 1.6${\pm}$0.7 and 1.7${\pm}$1.8 mm, respectively. Eleven lesions were located in the left abdominal or paraumbilical regions. Children who underwent surgical management were older than children with transient small bowel intussusception (mean age, 51 vs. 109 months). The mean diameter of the lesions and mean thickness of the outer rims were greater in the surgically-managed group. The location of intussusception was not significantly different between the two groups. Conclusion: Small bowel intussusception was spontaneously reduced in a large number of pediatric patients. However, sonographic demonstration of larger size, older age, and pathologic lead point warrant surgical intervention.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.31-31
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• 2010

The growth of the high-quality GaN epilayers is of significant technological importance because of their commercializedoptoelectronic applications as high-brightness light-emitting diodes (LEDs) and laser diodes (LDs) in the visible and ultraviolet spectral range. The GaN-based heterostructural epilayers have the polar c-axis of the hexagonal structure perpendicular to the interfaces of the active layers. The Ga and N atoms in the c-GaN are alternatively stacked along the polar [0001] crystallographic direction, which leads to spontaneous polarization. In addition, in the InGaN/GaN MQWs, the stress applied along the same axis contributes topiezoelectric polarization, and thus the total polarization is determined as the sum of spontaneous and piezoelectric polarizations. The total polarization in the c-GaN heterolayers, which can generate internal fields and spatial separation of the electron and hole wave functions and consequently a decrease of efficiency and peak shift. One of the possible solutions to eliminate these undesirable effects is to grow GaN-based epilayers in nonpolar orientations. The polarization effects in the GaN are eliminated by growing the films along the nonpolar [$11\bar{2}0$] ($\alpha$-GaN) or [$1\bar{1}00$] (m-GaN) orientation. Although the use of the nonpolar epilayers in wurtzite structure clearly removes the polarization matters, however, it induces another problem related to the formation of a high density of planar defects. The large lattice mismatch between sapphiresubstrates and GaN layers leads to a high density of defects (dislocations and stacking faults). The dominant defects observed in the GaN epilayers with wurtzite structure are one-dimensional (1D) dislocations and two-dimensional (2D) stacking faults. In particular, the 1D threading dislocations in the c-GaN are generated from the film/substrate interface due to their large lattice and thermal coefficient mismatch. However, because the c-GaN epilayers were grown along the normal direction to the basal slip planes, the generation of basal stacking faults (BSFs) is localized on the c-plane and the generated BSFs did not propagate into the surface during the growth. Thus, the primary defects in the c-GaN epilayers are 1D threading dislocations. Occasionally, the particular planar defects such as prismatic stacking faults (PSFs) and inversion domain boundaries are observed. However, since the basal slip planes in the $\alpha$-GaN are parallel to the growth direction unlike c-GaN, the BSFs with lower formation energy can be easily formed along the growth direction, where the BSFs propagate straightly into the surface. Consequently, the lattice mismatch between film and substrate in $\alpha$-GaN epilayers is mainly relaxed through the formation of BSFs. These 2D planar defects are placed along only one direction in the cross-sectional view. Thus, the nonpolar $\alpha$-GaN films have different atomic arrangements along the two orthogonal directions ($[0001]_{GaN}$ and $[\bar{1}100]_{GaN}$ axes) on the $\alpha$-plane, which are expected to induce anisotropic biaxial strain. In this study, the anisotropic strain relaxation behaviors in the nonpolar $\alpha$-GaN epilayers grown on ($1\bar{1}02$) r-plane sapphire substrates by metalorganic chemical vapor deposition (MOCVO) were investigated, and the formation mechanism of the abnormal zigzag shape PSFs was discussed using high-resolution transmission electron microscope (HRTEM).

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.26-32
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• 2009

Purpose : The increasing use of ultrasonography has allowed for an increase in the of the detection of congenital hydronephrosis, and the clinical outcomes of congenital hydronephrosis are widely varied. In this study, the necessity of voiding cystourethrography in neonate with hydronephrosis to rule out vesicoureteral reflux (VUR) was evaluated. Methods : Between January 2004 and December 2007, we reviewed the medical record of 157 childrens with congenital hydronephrosis detected within 1 month of age. The severity of hydronephrosis was graded by SFU (Society of Fetal Urology) system, and anterior posterior pelvic diameter (APPD). We evaluated the relationship between severity of hydronephrosis and incidence of VUR by using SPSS windows version 16.0. A P-value<0.05 is considered to be statistically significant. Results : Total renal unit number was 254, and 20(7.8%) renal units had VUR. We did not find any relationship between hydronephrosis grade the presence of VUR grade (P>0.05). In addition, there was no statistical significance between APPD, laterality of hydronephrosis and VUR incidence. However, renal units with VUR had lower spontaneous resolution rate (P<0.05), compared to renal units without VUR. Conclusion : In this study, there was no statistical significance between the severity of hydronephrosis and presence of VUR. Therefore, voiding cystourethrogram is recommended for all children with hydronephrosis to rule out VUR, regardless of the severity of hydronephrosis.

• The Korean Journal of Pain
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• v.5 no.2
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• pp.258-262
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• 1992

Herpes zoster is an acute infectious viral disease which affects the posterior spinal root ganglion of the spinal nerve. A single posterior spinal root ganglion or a small number of adjacent ones may be affected, usually on the same side. The corresponding ganglia of the cranial nerve may also be similarly affected. The causative virus, varicella zoster, belongs to the group of host-specific DNA viruses. Postherpetic neuralgia is a continuation of herpes zoster in older patients. Although spontaneous resolution of herpes zoster may be expected in most patients, a significant number experience intractable pain. Postherpetic neuralgia is one of the most difficult problems encountered by physicians. There are many methods for management of postherpetic neuralgia, but there is no method that results in complete remission. Laser has lately come into use to reduce several acute or chronic pains. In order to determine the degree of pain relief by laser, 27 patients of postherpetic neuralgia were irradiated with He Ne, Infrared, and $CO_2$ combine scan moded lasers two to three times per week. The results were as follows: 1) The most frequent site was thoracic vertebral nerve area. 2) Patients younger than 70 years of age showed an improvement rate of 57% vs 27% for those patients older than 70 years of age. 3) Laser therapy proved effective of those patients who received the laser treatment within one month of the onset of the disease. 4) For those patients who received treatment within one month of the disease and reflecting a 50% improvement rate, the average irradiation time was 5.7.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.5
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• pp.497-506
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• 2000

This study is comprised of data obtained from the files of 346 patients with temporomandibular disorders. All patients were diagnosed, treated and followed in the Department of Dentistry at the Inha university hospital, Incheon, Korea. The patients had treated with medications, physical therapy, occlusal splint and arthrocentesis. The study data were obtained from the medical records and telephone interviews that were conducted by research assistants. The results were as follows 1. The patient's main complaint was pain(77%), and mouth opening limitation was 17%. 2. An analysis of the medical records of the 346 patients disclosed that 82% were improved and 17% had no improvement when they were dismissed. 1% of the patients had become worse during therapy. 3. A success rate of 82% was achieved when medication assisted physical therapy was included. In the current status at the telephone interview, 270 patients(89%) reported that they were doing well with 56% describing themselves as asymtomatic and 32% experiencing only minor residual or recurrent symptoms. 11% regarded themselves as unimproved and worse. 4. In the current status of the unsuccessfully treated patients by medications and physical therapy, 64% of patients were doing well(3% as asymptomatic and 56% as only minor residual or recurrent symptom). But 36% of patients was reported as unimproved and worse. 5. TMJ has a remarkable adaptive potential and TMJ disorder has a natural history of spontaneous fluctuations and favorable prognosis during the subsequent natural course. 6. In the treatment of the temporomandibular disorders, there is a treatment ladder, starting with the simplest and least expensive treatment, that is ascended until resolution of the patient's symptoms occur. These findings suggest that conservative reversible therapies are both sufficient and appropriate for management of temporomandibular disorder in most patients. Major alterations of mandibular position or dentoalveolar relationships do not appear to be necessary for obtaining either short term or long term success and therefore they can be generally regards as inappropriate treatment for this disorder. The fact that physical therapy is non-invasive and does not appear to be fraught with irreversible changes, makes it a very applicable vehicle in the area of clinical TMJ disorder management.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.88-94
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• 2011

Ranula is a mucosal cyst that occurs in the mouth floor. This is a pseudo cyst caused by mucous retention within the tissue due to the rupture of catheter in the salivary gland. Ranula occurs mainly in a unilateral form and is characterized by painless bluish transparent swelling, with a increasing mass size. If the size is large, it can cause discomfort during swallowing, pronounciation, and mastication, but external swelling and infection is rare. Treatments include observation for spontaneous resolution, simple incision and drainage, marsupialization and excision. Marsupialization done by removing parts of the cyst wall and connecting it to the oral mucosa. It is a conservative procedure and recommended for children. It has advantages such as maintaining outline of oral tissue and less risk of damaging anatomic structure. Recurrence is common, mostly occurring within 4 months after surgery. This case is about a eight-year-old girl with ranula on the right mouth floor. This patient was treated with marsupialization that is one of treatment for ranula, and recurrence was not observed.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.3
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• pp.393-398
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• 1997

Cytogenetic analysis was performed in 1321 couples and 141 women with history of abnormal reproductive outcome during 1988-1996. The use of high resolution banding technique and fluorescence in situ hybridization (FISH) in the chromosome analysis has made the precise evaluation of chromosome aberrations. The prevalence of balanced chromosomal translocation carriers were 3.74% (104/2783 patients). 70 cases (2.52%) were reciprocal translocation carriers and 34 (1.22%) had Robertsonian translocations. Chromosome aberrations were more frequent in women (73 cases) than in men (31 cases). No phenotypical abnormalities were found in all carriers, but they experienced abnormal reproductive outcomes such as recurrent spontaneous abortions, anomalous offsprings or infertility problem. Prenatal diagnosis was carried out on 36 subsequent pregnancies in balanced translocation carriers. The fetal karyotypes showed that 12 cases (33%) were normal, 22 (61%) were balanced translocations, and two (6%) were unbalanced translocations. It is concluded that the prevalence of balanced chromosomal translocations in patients with abnormal reproductive outcome is higher than that of the normal population. Most of the fetal samples showed normal karyotypes or balanced translocations. Although the incidence of chromosomal imbalance in the fetuses was relatively low in prenatal diagnosis, individuals with balanced translocations are predisposed to abnormal offspring with partial trisomy or monosomy. Therefore we recommend that genetic counselling and cytogenetic prenatal diagnosis for translocation carriers have to be offered to prevent recurrent chromosomal abnormal babies.