• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.640-658
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• 1996

The purpose of this study was to examine the mechanism of improving acid resistance of Nd-YAG laser irradiated tooth enamel and determine the most effective energy density for improving acid resistance. The bovine tooth enamel were lased with a pulsed Nd-YAG laser. The energy densities of exposed laser beam were varied from 10 to $70\;J/cm^2$. To investigate the degree of improving acid resistance by irradiation, all the samples were submerged to demineralize in 0.5 N $HClO_4$ solution for 1 minute. After 1 minute, 0.05 % $LaCl_3$ was added to the solution for interrupting the demineralization reaction. The amounts of dissolved calcium and phosphate in the solution were measured by using an atomic absorption spectrophotometer and the UV/VIS spectrophotometer, respectively. To examine the mechanism of improving acid resistance, X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy were taken. The X-ray diffraction pattern of the samples were obtained in the $10^{\circ}{\sim}80^{\circ}2{\theta}$ range with $Cu-K{\alpha}$ radiation using M18HF(Mac Science Co.) with X-ray diffractometer operating at 40 KV and 300 mA. The infra-red spectra of the ground samples in 300 mg KBr pellets 10 mm diameter were obtained in the $4000cm^{-1}\;to\;400cm^{-1}$ range using JASCO 300E spectrophotometer. The scanning electron microscopy was carried out using JSM6400(JEOL Co.) with $500{\sim}2000$ times magnification. The results were as follow 1. The concentration of calcium dissolved from laser irradiated enamel with $50J/cm^2$ was significantly lesser than that of unlased control group (p<0.05) 2. From the result of the X-ray diffraction analysis, $\beta$-TCP, which increases acid solubility, was identified in lased enamel but the diffraction peaks of (002) and (004) became sharp with increasing energy density of laser irradiation. This means that the crystals in lased samples were grown through the c-axis and subsequently, the acid solubility of enamel decreased. 3. The a-axis parameter was slightly increased by laser irradiation, whereas the c-axis parameter was almost constant except for a little decrease at $50J/cm^2$. 4. In the infra-red spectra of lased enamels, phosphate bands ($600{\sim}500cm^{-1}$), B-carbonate bands (870, $1415{\sim}1455cm^{-1}$), and A-carbonate band ($1545cm^{-1}$) were observed. The amounts of phosphate bands and the B-carbonate bands were reduced, on the other hand, the amount of the A-carbonate band was increased by increase the energy density. 5. The SEM experiments reveal that the surface melting and recrystallization were appeared at $30J/cm^2$ and the cracks were observed at $70J/cm^2$. From above results, It may be suggested that the most effective energy density for improving acid resistance of tooth enamel with the irradiation of Nd-YAG laser was $50J/cm^2$. The mechanism of improving acid resistance were reduction of permeability due to surface melting and recrystallization of lased enamel and reduction of acid solubility of enamel due to decrease of carbonate content and growth of crystal.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.8 no.1
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• pp.31-40
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• 2005

Purpose: This study aimed to provide, as a basic material, the experiences of endoscopy in diagnosis and treatment of tumorous conditions in the upper gastrointestinal tract in children. Methods: The objects were 26 patients diagnosed as having tumorous conditions in the upper gastrointestinal tract among 1,283 patients who underwent upper gastrointestinal endoscopic examination at the Department of Pediatrics, Pusan National University Hospital, from January 1994 to July 2004 retrospectively. The characteristics of patients, the chief complaints for endoscopic examination, the sorts of tumors diagnosed, the endoscopic findings of tumors, and the treatment of tumors were analysed. Results: 1) Eleven male and fifteen female were included, whose mean age was $6.93{\pm}4.02years$. 2) The chief complaints for endoscopic examination were abdominal pain (80.7%), vomiting or nausea (30.8%), and gastrointestinal beeding (30.7%) in order. 3) Six cases of ectopic pancreas, five cases of sentinel polyp, three cases of papilloma and vallecular cyst, two cases of Brunner's gland hyperplasia and gastric submucosal tumor, one case of gastrointestinal stromal tumor, duodenal intramural hematoma, T cell lymphoma, lipoma, and Peutz-Jeghers syndrome were diagnosed by endoscopy with or without biopsy. 4) The location of tumors was in the pharynx (19.2%), esophagus (7.7%), gastro-esophageal junction (23.0%), stomach (30.7%) and duodeneum (26.9%). 5) The size of tumors was less than 10 mm in 53.8%, 10~20 mm in 26.9%, more than 20 mm 19.2%. 6) Treatments for tumors included resection by laser, surgical resection, endoscopic polypectomy with a forcep or snare, and observation 7) There was no significant complication. Conclusion: Various and not a few tumors were found in the upper gastrointestinal tract. The endoscopy was accurate, effective, and safe means for diagnosis and treatment of those lesions in children.

• Korean Journal of Acupuncture
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• v.22 no.2
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• pp.9-24
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• 2005

Objective: We have studied the effects of acupuncture and low level He-Ne laser therapy(LLLT) at $SI_3$, $BL_{40}$ on the tibial, sural nerve injury due to sports-damage or traffic accident and L5 spinal nerve ligature model like general herniation of nucleus pulposus(HNP) in a rat of neuopathic pain. Methods: A model of neuropathic pain was made by injuring tibial nerve and sural nerve while common peroneal nerve was maintained. Also, it was made by isolating left 5th lumbar spinal nerve. Three weeks after the neuropathic surgery, acupuncture and LLLT was injected at $SI_3$,$BL_{40}$ one time a day for one week. LLLT was divided three groups, that is LLLT-1(5mW), LLLT-2(10mW) and LLLT-3(30mW). After that, we examined the withdrawal response of neuropathic rats' legs by Von frey filament and acetone stimulation. And also we examined c-Fos, Nocieptin and KOR-3 in the midbrain central gray of neuropathic rats. Results: As we have observed the effect of mechanical allodynia, LLLT-3 group were diminished on 4 day, 5 day, 6 day and 7 day in the resection model compared with control model, LLLT-1 group were diminished on 5 day, LLLT-2 group were diminished on 3 day and 6 day, LLLT-3 group were diminished on 3 day, 4 day, 5 day, 6 day and 7 day in connected model compared with control group. As we have observed the effect of cold allodynia, LLLT-3 group were diminished on 7 day in the resection model compared with control model, LLLT-1 group were diminished on 6 day, 7 day, LLLT-3 group were diminished on 7 day in connected model compared with control group. As we have observed the effect of activity of c-Fos in the central gray part, LLLT-3 were diminished in resection model compared with control group, LLLT-1 group were diminished in connected model compared with control group. As we have observed the effect of activity of Nociceptin in the central gray part, resection model were not increased compared with control group, LLLT-1 group and LLLT-3 group were increased in connected model compared with control model. As we have observed the effect of activity of KOR-3 in the central gray part, resection model were not increased compared with control group, LLLT-3 group were increased in connected model compared with control model. Conclusions: We have noticed that LLLT-1 and LLLT-3 group have more controllable effect than acupuncture group. This study can be used in clinical therapy for neuropathic pain. But it is not reliability that Nociceptin and KOR-3 have effectively to control pain. Therefore We have to follow up about that.

• Journal of the Korea Society of Computer and Information
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• v.26 no.6
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• pp.173-181
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• 2021

Chinese people have increasingly high interests in skin care and trust and prefer medical institution products and equipment to treat skin problems. The purpose of this study is to examine skin types and skin care situations, skin care recognition, and skin care satisfaction by gender in medical skin care center patients from in their 10s to 50s in Hainan Province, China. The questionnaire survey consisted of general characteristics(n=8), skin care situations(n=6), skin care recognition(n=11), and skin care satisfaction(n=21). A total of 328 questionnaires were researched from December 21, 2020 to January 9, 2021 using WeChat and Wenjuanxing program. Data were analyzed by SPSSWIN 21.0. Frequency analysis was applied for general characteristics, skin care situations, skin care recognition, and skin care satisfaction and Cronbach's α was used for the reliability of skin care recognition and satisfaction. The relationship among skin care situations, skin care recognition, and skin care satisfaction was analyzed by χ² test and t-test. As a result, the common skin types by gender was dry skin in females and oily skin in males. The highest skin trouble was melasma and pigments in females and pimple in males. The most common way to manage troubled skin was homecare in both females and males, followed by the dermatology department in females and pharmacy in males, suggesting a significant difference. The common period of skin trouble was from one year to three years and the most effective way to improve skin was good life habit, followed by laser treatment in both females and males. The most important consideration to choose a hospital was a famous franchise hospital and the most important matters in management was doctor or skin care professionalism. Skin care and treatment recognition was high in external effects for females and internal effects for males. Skin care satisfaction was high in service for females and effect for males. Skin care satisfaction was significantly higher in males than in females. In conclusion, there was a difference in skin types, skin troubles, skin problems, skin care ways, and skin care satisfaction by gender in Chinese medical skin care center patients. Therefore, this study suggests the development of various products and the need of systematic management programs.