ABSTRACT
PURPOSE: The purpose of this study was to investigate the corrosion behaviors of dental implant alloy after micro-sized surface modification in electrolytes containing Mn ion. MATERIALS AND METHODS: Mn-TiO₂ coatings were prepared on the Ti-6Al-4V alloy for dental implants using a plasma electrolytic oxidation (PEO) method carried out in electrolytes containing different concentrations of Mn, namely, 0%, 5%, and 20%. Potentiodynamic method was employed to examine the corrosion behaviors, and the alternating-current (AC) impedance behaviors were examined in 0.9% NaCl solution at 36.5℃±1.0℃ using a potentiostat and an electrochemical impedance spectroscope. The potentiodynamic test was performed with a scanning rate of 1.667 mV s⁻¹ from −1,500 to 2,000 mV. A frequency range of 10⁻¹ to 10⁵ Hz was used for the electrochemical impedance spectroscopy (EIS) measurements. The amplitude of the AC signal was 10 mV, and 5 points per decade were used. The morphology and structure of the samples were examined using field-emission scanning electron microscopy and thin-film X-ray diffraction. The elemental analysis was performed using energy-dispersive X-ray spectroscopy. RESULT: The PEO-treated surface exhibited an irregular pore shape, and the pore size and number of the pores increased with an increase in the Mn concentration. For the PEO-treated surface, a higher corrosion current density (I(corr)) and a lower corrosion potential (E(corr)) was obtained as compared to that of the bulk surface. However, the current density in the passive regions (I(pass)) was found to be more stable for the PEO-treated surface than that of the bulk surface. As the Mn concentration increased, the capacitance values of the outer porous layer and the barrier layer decreased, and the polarization resistance of the barrier layers increased. In the case of the Mn/Ca-P coatings, the corroded surface was found to be covered with corrosion products. CONCLUSION: It is confirmed that corrosion resistance and polarization resistance of PEO-treated alloy increased as Mn content increased, and PEO-treated surface showed lower current density in the passive region.
Subject(s)
Alloys , Corrosion , Dental Implants , Dielectric Spectroscopy , Electric Impedance , Electrolytes , Manganese , Methods , Microscopy, Electron, Scanning , Plasma , Spectrum Analysis , X-Ray DiffractionABSTRACT
PURPOSE: Serum level of 25-hydroxyvitamin D (25-OHD) is considered as the most appropriate marker of vitamin D status. However, only a few studies have investigated the relationship between 25-OHD and parathyroid hormone (PTH) in children. To this end, this study was aimed at evaluating the lowest 25-OHD level that suppresses the production of parathyroid hormone in children. METHODS: A retrospective record review was performed for children aged 0.2 to 18 years (n=193; 106 boys and 87 girls) who underwent simultaneous measurements of serum 25-OHD and PTH levels between January 2010 and June 2014. RESULTS: The inflection point of serum 25-OHD level for maximal suppression of PTH was at 18.0 ng/mL (95% confidence interval, 14.3–21.7 ng/mL). The median PTH level of the children with 25-OHD levels of <18.0 ng/mL was higher than that of children with 25-OHD levels ≥ 18.0 ng/mL (P<0.0001). The median calcium level of children with 25-OHD levels<18.0 ng/mL was lower than that of children with 25-OHD levels≥18.0 ng/mL (P=0.0001). The frequency of hyperparathyroidism was higher in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels≥18.0 ng/mL (P<0.0001). Hypocalcemia was more prevalent in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels≥18.0 ng/mL (P<0.0001). CONCLUSION: These data suggest that a vitamin D level of 18.0 ng/mL could be the criterion for 25-OHD deficiency in children at the inflection point of the maximal suppression of PTH.
Subject(s)
Child , Humans , Calcium , Hyperparathyroidism , Hypocalcemia , Parathyroid Hormone , Retrospective Studies , Vitamin D , Vitamin D DeficiencyABSTRACT
Kawasaki disease (KD) is the self-limited and multisystem vasculitis which accompanies many complications. Ophthalmic findings in KD are bilateral conjunctival injection, iridocyclitis, superficial keratitis, vitreous opacities and subconjunctival hemorrhage. Optic disc swelling is a rare ophthalmic complication in KD. We describe a 3-year-old boy who presented with 7 days of fever, both conjunctival injection without discharge, and right cervical lymph node enlargement of more than 1.5 cm. He was diagnosed as incomplete KD. He had no ocular symptom except bilateral conjunctival injection. On ophthalmic examination, he was diagnosed by anterior uveitis with optic disc swelling. The brain magnetic resonance imaging was performed and revealed no evidence of increased intracranial pressure. Echocardiography revealed the dilated right coronary artery up to 3.4 mm. Fever subsided and optic disc swelling was completely improved after intravenous immunoglobulin (2 g/kg) treatment. Optic disc swelling is a rare ophthalmic complication in KD.
Subject(s)
Child, Preschool , Humans , Male , Brain , Coronary Vessels , Echocardiography , Fever , Hemorrhage , Immunoglobulins , Intracranial Pressure , Iridocyclitis , Keratitis , Lymph Nodes , Magnetic Resonance Imaging , Mucocutaneous Lymph Node Syndrome , Papilledema , Uveitis , Uveitis, Anterior , VasculitisABSTRACT
Malignant salivary gland tumors only represent 0.08% of all childhood tumors and mucoepidermoid carcinoma (MEC) is the most common histologic type. Although there are many reports describing second malignant neoplasm (SMN) in patients treated for childhood cancer, salivary gland tumors rarely appears. In Korea, there has been no report about MEC that developed in children as a SMN. We report a MEC in a 4 years and 8 months old female child that developed after completing treatment for yolk sac tumor of lower abdomen. The primary tumor presented with metastasis at the time of diagnosis, and therefore, the child underwent high-dose chemotherapy with autologous peripheral blood stem cell transplantation along with surgery and radiotherapy. Three years and five months after completing treatment, MEC developed in her submandibular gland. She was treated with surgery and radiotherapy and is in disease free state for 5 months at the time of this writing.
Subject(s)
Child , Female , Humans , Abdomen , Carcinoma, Mucoepidermoid , Diagnosis , Drug Therapy , Endodermal Sinus Tumor , Korea , Neoplasm Metastasis , Peripheral Blood Stem Cell Transplantation , Radiotherapy , Salivary Gland Neoplasms , Salivary Glands , Submandibular Gland , WritingABSTRACT
Malignant salivary gland tumors only represent 0.08% of all childhood tumors and mucoepidermoid carcinoma (MEC) is the most common histologic type. Although there are many reports describing second malignant neoplasm (SMN) in patients treated for childhood cancer, salivary gland tumors rarely appears. In Korea, there has been no report about MEC that developed in children as a SMN. We report a MEC in a 4 years and 8 months old female child that developed after completing treatment for yolk sac tumor of lower abdomen. The primary tumor presented with metastasis at the time of diagnosis, and therefore, the child underwent high-dose chemotherapy with autologous peripheral blood stem cell transplantation along with surgery and radiotherapy. Three years and five months after completing treatment, MEC developed in her submandibular gland. She was treated with surgery and radiotherapy and is in disease free state for 5 months at the time of this writing.
Subject(s)
Child , Female , Humans , Abdomen , Carcinoma, Mucoepidermoid , Diagnosis , Drug Therapy , Endodermal Sinus Tumor , Korea , Neoplasm Metastasis , Peripheral Blood Stem Cell Transplantation , Radiotherapy , Salivary Gland Neoplasms , Salivary Glands , Submandibular Gland , WritingABSTRACT
PURPOSE: The purpose of this study was to measure patient satisfaction among injured workers and determine the factors that affect satisfaction of the hospital services. METHODS: The subjects of this study were 231 injured workers hospitalized in I WC Hospital and D WC Hospital located in one of the major cities in Korea, all of whom agreed to participate in this research. The questionnaires were selected as literature suggested for explaining satisfaction of the hospital services, general characteristics of injured workers, characteristics of the hospital services. The data were analyzed with descriptive statistics, t-test, ANOVA, multiple regression analysis by SPSS/WIN 18.0. RESULTS: The patient satisfaction level is at 3.2 point, which is lower than general patient satisfaction in previous study. There were significant differences in satisfaction scores, depending on the gender, degree of medical treatments, the specialty of medical team, staff's kindness, medical treatment process, the cleanliness of hospital and the convenience of facilities. It was found that the patient satisfaction among injured workers is affected by the characteristics of the hospital services. CONCLUSION: It is necessary to promote medical facilities, specialization of doctors and nurses, staff's kindness, medical treatment process and hospital cleanliness for developing Workers' Compensation hospital services.