PURPOSE: Ni-Cr alloy does not contain Beryllium, causing the metal compound to form oxides in the furnace but by using Titanium as a chemical catalyst the forming of the oxides can be controlled, and by controlling the impurities formed on the metal surface, the possibility of the Ni-Cr alloy bond strength being increased can be analysed. MATERIALS AND METHODS: Titanium was used as a chemical catalyst in the porcelain for the oxidation of beryllium-free metal (Ni-Cr) alloy. The T1 group, which does not use Titanium power as a chemical catalyst is a reference model for comparison. The T2 group and T3 group used 10 g and 20 g of Titanium power, respectively. They are fabricated to observe the shear bond strength and surface properties. There was no significance when One-way ANOVA analysis/Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups (P > 0.05). RESULTS: Results of measuring the three-point flexural bond strength of the Ni-Cr alloy and thickness of the oxide film. Experiment T3 using 20 g Titanium chemical catalyst: 39.22 ± 3.41 MPa and 6.66 µm, having the highest bond strength and thinness of oxide film. Experiment T2 using 10 g Titanium chemical catalyst: 34.65 ± 1.39 MPa and 13.22 µm. Experiment T1 using no Titanium chemical catalyst: 32.37 ± 1.91 MPa and 22.22 µm. CONCLUSION: The T2 and T3 experiments using Titanium chemical catalyst showed higher bond strength for the Ni-Cr alloy and lower thickness of oxide film than experiment T1, and the titanium catalyst being able to increase bond strength was observed.
Alloys ; Beryllium ; Dental Porcelain ; Hot Temperature* ; Oxides ; Surface Properties ; Thinness ; Titanium*

Open long bone fracture is frequently difficult to reduce and maintain, especilly when there is extensive soft tissue damage. Infection, instability, malalignment and soft tissue complication often result in prolonged mobidity or failure. The Hoffmann's apparatus have merits, that can easily correct distracted, angular or rotational deformity of fracture site during early post-operative period, and stable fixation facilitates easily to the care of soft tissue injury. In addition, the affected limb can be elevated with balanced suspension, possible early exercise of neighboring joints. But we have exerienced some problems during treatment of fracture with Hoffmann's transfixation method. From February 1980 to December 1981, Hoffmann's transfixation method was employed in treatment of twenty-one patients that considered to have a poor prognosis with conversional forms of treatment. The results were obtained as follows; 1. For correction of distracted, angular, or rotational deformity, the fracture site should be reduced accurately. 2. Hoffmann pins should be transfixed as one plane and parrallel to each other. 3. Rigidity of fixation can be increased by increasing number of pins, actually three or more pins should be applied at each fragment of fracture. 4. Hoffmann's apparatus is more complex for management, more expensive and requires skillful technique compared with other external fixation apparatus. 5. The lateral view of fracture site could not be confirmed accurately due to overlapping of Hoffmann's adjustable connecting rod and bony shadow. 6. The main cause of injuries was due to traffic accidents in 17 cases (81%), involving tibia in 18 cases, femur in 2 cases and humerus in 1 case. 7. In the sixteen cases which could be assessed, the average times for external transfixation was 13.9 weeks and then followed by early weight bearing with P.T.B. cast or brace. The average time of bony union was 26.4 weeks. 8. The final result was excellent in 7 cases, good in 5 cases, acceptable in 3 cases, poor in 1 case.
Accidents, Traffic ; Braces ; Congenital Abnormalities ; Extremities ; Femur ; Fractures, Bone ; Fractures, Open ; Humans ; Humerus ; Joints ; Methods ; Prognosis ; Soft Tissue Injuries ; Tibia ; Weight-Bearing

The new trial to apply the closed I-M nailing for 23 cases of long bone fracture has been used our department, loss of hematoma, further damage to periosteum and soft tissue were prevented; the risk of infection was reduced; and the early functional use of extremities without additional superflous external fixation could be made. The results obtained were as follows; 1. There was no case of non-union or other complication. 2. The average bone union rate was 26.1 weeks in femur, 22 weeks in tibia, or 11.5 weeks in forearm. 3. The advantages is simple method and be able to do early ambulation without following muscular atrophy or ankylosis. 4. The patients were satisfactory about cosmetic problem after operation. 5. The merits of this operation were the short hospitalization and early adaptation of social activity. 6. In conclusion, closed I-M nailing is method of choice for long bone shaft fracture when internal fixation is indicated and our operative is useful and simple.
Ankylosis ; Early Ambulation ; Extremities ; Femur ; Forearm ; Fracture Fixation, Intramedullary ; Fractures, Bone ; Hematoma ; Hospitalization ; Humans ; Methods ; Muscular Atrophy ; Periosteum ; Tibia

Aim. A neurobehavioral test for workers exposed to organic solvents in the workplace can be affected by many factors : age, education, motivation, ethnicity, etc. To apply more suitable neurobehavioral test for Korean workers, we evaluated the validity of several items of computerized and traditional neurobehavioral tests. Methods. We have applied eleven tests : four items of computerized neurobehavioral test(Swedish Performance Evaluation System) including Addition, Symbol-Digit, Digit Span, and Finger tapping speed, and seven items of traditional neurobehavioral test consisting of Addition, Digit-Symbol , Digit Span, Benton visual retention test, Pursuit aiming, Pegboard, and Tapping. These tests were performed on 96 workers exposed to solvents, and 100 reference workers. The concurrent and construct validities were evaluated by group difference, correlation with age, educational level, hippuric acid level, neurotoxic symptom, current exposure level, multitrait-multimethod matrix, factor analysis, and discriminant analysis. Results. Statistically significant differences were observed between the workers exposed to solvents and referents in computerized Symbol-Digit, Finger tapping speed, traditional Digit-Symbol and Pegboard. The computerized Symbol-Digit, traditional Digit-Symbol, Addition, Benton visual retention test, and Pegboard were found to be related to the age. The performance of computerized Symbol-Digit, Addition, and traditional Digit-Symbol were found to be related to the educational level significantly. The computerized Symbol-Digit, Finger tapping speed, and traditional Digit-Symbol were found to be related to hippuric acid, and neurotoxic symptom. The discriminability of Finger tapping speed, and Pegboard was better than the other tests. In discriminant analysis, the model with two variables, the computerized Symbol-Digit and Pegboard, classified almost 70 percent of the workers correctly. Conclusions. These results suggest that the computerized Symbol-Digit, Finger tapping speed, and Pegboard are more satisfactory for our purpose, and the Addition, Tapping, Benton visual retention test, and Pursuit aiming are less valid than other items. These may allow the reasonable selection of core neurobehavioral tests for workers exposed to solvents in Korea.
Education ; Fingers ; Korea ; Motivation ; Solvents

PURPOSE: The present study investigated the influences of various gypsum materials on the precision of fit of CAD/CAM-fabricated prostheses and analyzed their correlation with surface roughness. MATERIALS AND METHODS: The master model of the mandibular right first molar was replicated, and four experimental groups based on two types of Type IV stone (GC Fujirock EP, Die keen) and two types of scannable stone (Aesthetic-Basegold, Everest Rock) were created to include a total of 40 specimens, 10 in each group. The surface roughness of the working models for the respective experimental groups was measured. Once the zirconia cores had been fabricated, the marginal and internal fits were measured with a digital microscope using the silicone replica technique. The mean and standard deviation of the respective points of measurement were computed and analyzed through the one-way ANOVA and Tukey's HSD test. The correlation between surface roughness and the precision of fit of the zirconia core was analyzed using the Pearson correlation analysis (alpha=.05). RESULTS: The zirconia cores fabricated from the scannable stone working models exhibited a superior precision of fit as compared to those fabricated from the Type IV stone working models. The correlation analysis results showed a clear positive correlation between surface roughness and the precision of fit of zirconia cores in all of the experimental groups (P<.05). CONCLUSION: The results confirmed that the surface roughness of dental working models has a decisive influence on the precision of fit of zirconia cores.
Calcium Sulfate* ; Molar ; Prostheses and Implants ; Replica Techniques ; Silicones

Conventional angiography still remains the procedure of choice in evaluation of cerebral aneurysm. However, MRI and MR angiography can play different roles in vizualizing cerebral aneurysm. A 43-year-old male was evaluated for recurrent seizure attacks. The brain MRI showed non-enhancing iso-signal mass on T1WI, signal voiding mass with stalk-like structure on coronal T2WI in the right temporal region. MRA also revealed dark round signal. However, the conventional cerebral angiography failed to visualize it. Finally, the mass was confirmed as a huge aneurysm filled with intraluminal thrombus on operation. It should seem that contrast media could not fill the aneurysmal sac because of intraluminal thrombus in conventional angiography. But aneurysmal sac seemed to be visible on MRA as paramagnetic artifact of thrombus. So, it can be assumed that MRA is superior to the conventional angiography in some cases of cerebral aneurysm, especially when it is associated with intraluminal thrombus.
Adult ; Aneurysm ; Angiography* ; Artifacts ; Brain ; Cerebral Angiography ; Contrast Media ; Humans ; Intracranial Aneurysm* ; Magnetic Resonance Imaging ; Male ; Seizures ; Thrombosis

To contribute to promotion of health and preservation of labor power of Korean laborers, the body height and body weight were measured for 10,407 workers (6,201 male, 4,206 female) in the age group of 20-29, engaged in manufactures in the Gumi industrial complex, Gumi city, Kyungpook province. The above data were extracted from the 1985 periodic examination chart for calculation of the mean body weight, mean body height, correlation coefficient and regression equation between weight and height, standard body weight, body mass index(BMI) and distribution of laborers within Garrow's classification of BMI by age and sex group. Mean body height of 20-29 age group was 168.2+/-5.61 cm for male and 155.9+/-5.26 cm for female. Mean body weight of 20-29 age group was 61.4+/-6.56 kg for male and 52.4+/-6.00 kg for female. Correlation coefficient and regression equation of 20-29 age group were +0.541 and Y(Wt)=0.632X(Ht)-44.975 for male and +0.559 and Y(Wt)=0.637X(Ht)-46.898 for female. Standard body weight of 20-29 age group was 53.0kg at 155cm, 59.3kg at 165cm, 65.6kg at 175cm for male and 51.8kg at 155cm, 58.2kg at 165cm, 64.6kg at 175 cm for female. Range of normal body weight of 20-29 age group was 47.5+/-58.5kg at 155cm, 53.8+/-64.8kg at 165cm, 60.1+/-72.1kg at 175cm for male and 46.9+/-56.8kg at 155cm, 53.2+/-63.2kg at 165cm, 59.6+/-69.6 kg at 175 cm for female. Range of obesity of 20-29 age group was 64.1kg and over at 155cm, 70.3kg and over at 165cm, 76.7kg and over at 175cm for male and 61.8kg and over at 155cm, 68.2kg and over at 165cm, 74.5kg and over at 175 cm for female. Body mass index (kg/m2) of 20-29 age group was 21.7+/-1.95 for male and 21.6+/-2.05 for female, 75.9% of male laborers and 71.3% of famale counterparts fall in the desirable range of BMI by Garrow's classification.
Body Height ; Body Mass Index ; Body Weight* ; Classification ; Female ; Gyeongsangbuk-do ; Health Promotion ; Humans ; Ideal Body Weight ; Male ; Obesity

Background: and Purpose Fingolimod (FTY) inhibits lymphocyte egress from lymphoid organs to cause lymphopenia, but the clinical implications of FTY-induced lymphopenia are not fully understood. We aimed to determine the frequency and severity of lymphopenia during FTY treatment among Korean patients with multiple sclerosis (MS), and its association with infections. Methods: We retrospectively reviewed the medical records of patients with MS treated using FTY from 12 referral centers in South Korea between March 2013 and June 2021. Patients were classified according to their nadir absolute lymphocyte count (ALC) during treatment:grade 1, 800–999/μL; grade 2, 500–799/μL; grade 3, 200–499/μL; and grade 4, <200/μL. Results: FTY treatment was administered to 69 patients with a median duration of 18 months (range=1–169 months), with 11 patients being treated for ≥7 years. During FTY treatment, mean ALCs were reduced after the first month (653.0±268.9/μL, mean±standard deviation) (p<0.0001) and remained low during treatment lasting up to 84 months. During follow-up, 41 (59.4%) and 7 (10.1%) patients developed grade-3 and grade-4 lymphopenia, respectively.No significant difference was found in age at FTY initiation, sex, baseline ALC, body mass index, or prior disease-modifying treatment between patients with and without grade-4 lymphopenia. Infections were observed in 11 (15.9%) patients, and the frequencies of patients with and without grade-4 lymphopenia were similar. Conclusions FTY treatment induced grade-4 lymphopenia in 10% of South Korean patients with MS, but did not appear to be associated with an increased infection risk.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.