The effects of primer precuring on the shear bond strength between gold alloy surfaces and metal brackets

The objective of this study was to investigate the effects of precuring of primer coated on bracket bases on the strength of bonds between metal brackets and gold alloy. Square type III gold alloy plates were sandblasted with 30 μm silicon dioxide. After silica coating, excessive particles were removed gently with air. Silane was then applied, and maxillary central incisor metal brackets were bonded to each conditioned alloy surface with Transbond XT. Half of the specimens were precured at the bracket base after primer coating and the other half was not precured before bonding to the alloy surface. After bracket positioning, samples were cured using a light emitting diode (LED) for 40 seconds. Shear bond strengths were tested and adhesive remnant index (ARI) was evaluated after 1 hour and 24 hours. The primer precuring and 24 hours group exhibited highest bond strength (12.53 MPa) and the no precuring and 1 hour group showed lowest bond strength (5.58 MPa). Precured groups showed lower ARI scores. Due to the shallow curing depth of LED light and inhibition of transillumination at the metal surface, primer precuring at the bracket base is required for secure bracket bonding on gold alloy surfaces using LED curing units.     

Mutations in UBQLN2 and SIGMAR1 genes are rare in Korean patients with amyotrophic lateral sclerosis

Mutations in the UBQLN2 and SIGMAR1 genes were recently identified in X-linked dominant amyotrophic lateral sclerosis and/or frontotemporal dementia (ALS and/or FTD) and FTD and/or motor neuron disease, respectively. Subsequent studies, however, found that UBQLN2 mutations were rare, and the pathogenicity of SIGMAR1 mutation in FTD and/or motor neuron disease was controversial. In the present study, we analyzed mutations in the UBQLN2 and SIGMAR1 genes in a Korean cohort of 258 patients with familial ALS (n = 9) or sporadic (sALS; n = 258) ALS. One novel UBQLN2 variant (p.D314E) was observed in 2 patients with sALS and 5 of 727 controls indicating that this variant might be a rare polymorphism rather than a disease-causing mutation. A novel SIGMAR1 gene variant in the 3′-untranslated region (c.*58T>C) was found in 1 sALS and was absent in 727 control samples. Taken together, our data suggest that causative mutations in the UBQLN2 and SIGMAR1 genes are rare in Korean patients with either familial or sporadic ALS.     

Preoperative Oral Carbohydrate Loading in Laparoscopic Gynecologic Surgery: A Randomized Controlled Trial

Study ObjectiveTo determine whether carbohydrate loading improves the postoperative quality of recovery (QoR) better than the midnight fasting policy in laparoscopic gynecologic surgeries.DesignRandomized, parallel-group trial.SettingTertiary university hospital.PatientsFemale patients scheduled for laparoscopic gynecologic surgery for nonmalignant gynecologic diseases.InterventionsEighty-eight women were randomly assigned to the midnight fasting group (nil per os, NPO group) or the carbohydrate loading group (carbohydrate group). Patients in both groups adhered to the enhanced recovery after surgery protocol except for carbohydrate intake in the carbohydrate group.Measurements and Main ResultsThe postoperative QoR was evaluated using the QoR 15-item questionnaire on postoperative day 2. The times to readiness for discharge of the groups were compared. The QoR 15-item questionnaire scores were 97.7 ± 23.0 in the NPO group and 99.6 ± 22.4 in the carbohydrate group; they were not statistically different (p = .702). The times to readiness for discharge of both groups were also not different: 36.8 ± 12.2 hours in the NPO group and 37.6 ± 11.8 hours in the carbohydrate group (p = .684).ConclusionThe benefit of carbohydrate beverage intake was not significant in laparoscopic gynecologic surgeries when following the enhanced recovery after surgery protocol.     

Process Steps for High Quality Si-Based Epitaxial Growth at Low Temperature via RPCVD

The key process steps for growing high-quality Si-based epitaxial films via reduced pressure chemical vapor deposition (RPCVD) are investigated herein. The quality of the epitaxial films is largely affected by the following steps in the epitaxy process: ex-situ cleaning, in-situ bake, and loading conditions such as the temperature and gaseous environment. With respect to ex-situ cleaning, dry cleaning is found to be more effective than wet cleaning in 1:200 dilute hydrofluoric acid (DHF), while wet cleaning in 1:30 DHF is the least effective. However, the best results of all are obtained via a combination of wet and dry cleaning. With respect to in-situ hydrogen bake in the presence of H₂ gas, the level of impurities is gradually decreased as the temperature increases from 700 °C to a maximum of 850 °C, at which no peaks of O and F are observed. Further, the addition of a hydrogen chloride (HCl) bake step after the H₂ bake results in effective in-situ bake even at temperatures as low as 700 °C. In addition, the effects of temperature and environment (vacuum or gas) at the time of loading the wafers into the process chamber are compared. Better quality epitaxial films are obtained when the samples are loaded into the process chamber at low temperature in a gaseous environment. These results indicate that the epitaxial conditions must be carefully tuned and controlled in order to achieve high-quality epitaxial growth.     

Comparative Study on Corrosion Protection of Reinforcing Steel by Using Amino Alcohol and Lithium Nitrite Inhibitors

In this study, the ability of lithium nitrite and amino alcohol inhibitors to provide corrosion protection to reinforcing steel was investigated. Two types of specimens—reinforcing steel and a reinforced concrete prism that were exposed to chloride ion levels resembling the chloride attack environment—were prepared. An autoclave accelerated corrosion test was then conducted. The variables tested included the chloride-ion concentration and molar ratios of anti-corrosion ingredients in a CaOH₂-saturated aqueous solution that simulated a cement-pore solution. A concentration of 25% was used for the lithium nitrite inhibitor LiNO₂, and an 80% solution of dimethyl ethanolamine ((CH₃)₂NCH₂CH₂OH, hereinafter DMEA) was used for the amino alcohol inhibitor. The test results indicated that the lithium nitrite inhibitor displayed anti-corrosion properties at a molar ratio of inhibitor of ≥0.6; the amino alcohol inhibitor also displayed anti-corrosion properties at molar ratios of inhibitor greater than approximately 0.3.     

Primary ovarian fibrosarcoma with long-term survival: a report of two cases

We report on two cases of primary ovarian fibrosarcoma detected in two women aged 44 and 34 years old. In the first case, an 18 x 17 x 10 cm multilobular tumor was detected in the left ovary. In the second case, a 13 x 9 x 3 cm and a 7 x 6 x 2 cm tumor were found in the left and right ovaries, respectively. In addition, a large quantity of ascitic fluid was detected. In both cases, a total hysterectomy with bilateral adnexectomy and an omentectomy were performed. No evidence of lymph-node enlargement was detected in either case. Microscopic findings demonstrated densely, cellular spindle-shaped tumor cells with increased mitotic activity (17 and 8/10 high-power fields, respectively). Immunohistochemical analyses showed that tumor cells were positive for vimentin and negative for smooth muscle actin, S-100, and estrogen receptor. Progesterone receptor was positive only in the second case. After surgery, both patients received several courses of combination chemotherapy. Neither patient demonstrated any evidence of disease recurrence during follow-up for 10 years and 5 years, respectively.     

Relationship of Bone Mineral Density and Knee Osteoarthritis (Kellgren-Lawrence Grade): Fifth Korea National Health and Nutrition Examination Survey

BackgroundOsteoarthritis (OA) and osteoporosis (OP) are the 2 most common bone disorders associated with aging. We can simply assume that older patients have a higher incidence of OA and OP with more severity. Although several papers have conducted studies on the relationship between OA and OP, none of them has demonstrated a conclusive link. In this study, we used radiological knee OA and bone mineral density (BMD; T-score of the total hip and lumbar spine) to analyze the incidence of OA and OP in a large population. We aimed to determine the relationship between OA and OP and investigate the associated risk factorsMethodsThis cross-sectional study used data extracted from the 2010–2012 Korea National Health and Nutrition Examination Survey. We evaluated a total of 4,250 participants aged ≥ 50 years who underwent knee radiography and dual-energy X-ray absorptiometry and their laboratory results. The relationship between radiological knee OA and BMD was assessed. The generalized linear model was used to evaluate the relationship between BMD and Kellgren-Lawrence (KL) grade.ResultsThe higher KL grade was associated with older age, higher body mass index (BMI), female sex, and lower hemoglobin level (p < 0.001). No significant association was found between OA and the following variables: white blood cell, platelet, total cholesterol, vitamin D, alkaline phosphatase, parathyroid hormone, hypertension, diabetes, asthma, dyslipidemia, smoking status, alcohol consumption, and regular exercise (p > 0.05). After adjusting for confounding factors (age, BMI, diabetes, hypertension, smoking, and alcohol consumption), the average T-scores of total hip and lumbar spine were the highest in the mild OA group with KL grade 2 (−0.22 ± 1.08 and −0.89 ± 1.46, respectively, p < 0.001). The average T-scores of the total hip and lumbar spine significantly decreased as OA progressed from moderate (KL grade 3; −0.49 ± 1.05 and −1.33 ± 1.38, respectively, p < 0.001) to severe (KL grade 4; −0.73 ± 1.13 and −1.74 ± 1.75, respectively, p < 0.001). T-scores of the moderate-to-severe OA group were significantly lower than those of the non-OA group (KL grades 0 and 1, p < 0.001).ConclusionsCompared with the non-OA group, BMD (T-scores of the total hip and lumbar spine) was higher in the mild OA group and lower in the moderate-to-severe OA group.