The word "Delayed" in the legend of Figure 2 should have been written as "Controls."

INTRODUNTION: The objective of the present study was to investigate bedtime, rise time and time-in-bed of Korean college students, separately on weekday and on weekend and to compare them. In addition, this study also aimed to evaluate the influence of gender, age and grade on the above sleep parmeters in Korean college students. METHODS: Information regarding bedtime and rise time, separately on weekday and on weekend, of Korean college students were obtained by self-administered questionnaire. Questionnaires of 1,825 students (1,416 females and 409 males, age 18-30 ; mean age 21.1+/-2.2) were used for statistical analyses. RESULTS: Korean college students retired to bed 50 minutes later (00 : 49 on weekday ; 01 : 40 on weekend ; t=39.67, p<0.001), rose 1 hour 58 minutes later (07 : 52 on weekday ; 09 : 50 on weekend ; t=39.46, p<0.001), and slept 1 hour 8 minutes longer (t=13.33, p<0.001) on weekend. Compared to male students, female students had earlier rise time (t=8.96, p<0.01 ; t=3.89, p<0.01) and earlier bedtime both on weekday and weekend (t=7.10, p<0.01; t=6.04, p<0.01), and shorter time-in-bed on weekday (t=1.99, p<0.01). In addition, rise time delay and time-in-bed increase on weekend were more prominent in female students than in male students (t=3.41, p<0.01 ; t=3.68, p<0.01). Grade was correlated with bedtime and rise time on weekday (beta=0.1022, p<0.01 ; beta=0.1009, p<0.01), bedtime and time-in-bed on weekend (beta=0.1096, p<0.01 ; beta=-0.0990, p<0.01), and differences between weekday and weekend of the rise time and the time-in-bed (beta=-0.0906, p<0.01 ; beta=-0.1115, p=0.02). CONCLUSIONS: In this study, Korean college students had earlier bedtime/rise time and shorter time-in-bed on weekday than on weekend. These findings suggest that weekday sleep-wake schedule of Korean college students may be advanced relative to their biological sleep-wake cycle and that this discrepancy may be associated with weekday sleep deprivation. In addition, differences of sleep patterns between weekday and weekend were more prominent in female students and students with lower grade. Therefore, discrepancy between weekday sleep-wake schedule and biological sleep-wake cycle, as well as weekday sleep deprivation, might be more serious in female or lower-grade students.
Appointments and Schedules ; Female ; Humans ; Male ; Surveys and Questionnaires ; Sleep Deprivation

PURPOSE: This prospective pilot study is a part of the Korean NIH's effort to characterize con- genital anomalies and genetic disorders in Korea and to establish a National Genetic Database. METHODS: This population-based study was conducted at all hospitals that deliver in the province of Suwon; a total of 39 hospitals from May 1, 1997 to April 30, 1999 for a two-year period. All outcome of pregnancies, including liveborn, stillborn, and TOP over 20wks gestation were subjects of this study for the presence of major congenital anomalies. Delivery records of each hospital and pediatric records of one tertiary hospital were collected and analyzed. RESULTS: The total number of pregnancy was 30,319 yielding 30,653 deliveries, including 269 still-born and 27 TOPs. The overall incidence of congenital anomalies was 1.2Yo(366 cases among 30,653 deliveries) with 0.5Yo from primary hospital, 1.4Yo of general hospital deliveries and 4.5Yo of tertiary hospital deliveries. The incidences of selective major congenital anomalies per 1,000 deliveries were 0.82 for Down syndrome, 1.79 for cleft lip with or without cleft palate, and 0.39 for open neural tube defect. CONCLUSION: This pilot study represented the first community-based population data on congenital anomalies in Korea, differing from previous studies based on selective population of relative high-risk population from tertiary hospital delivery. Search for congenital anomalies among cohort by reviewing pediatric records yielded 38Yo of total anomalies, indicating the importance of combining both delivery and pediatrics records in generating accurate data for the incidence of congenital anomalies. (J Korean Pediatr Soc 2000;43:738-745)
Cleft Lip ; Cleft Palate ; Cohort Studies ; Congenital Abnormalities* ; Databases, Genetic ; Down Syndrome ; Epidemiologic Studies* ; Gyeonggi-do ; Hospitals, General ; Incidence ; Korea ; Neural Tube Defects ; Parturition* ; Pediatrics ; Pilot Projects* ; Pregnancy ; Prospective Studies* ; Tertiary Care Centers

Purpose: The aim of this study was to compare the accuracy of dies fabricated using 3D printing system to conventional method and to evaluate overall volumetric changes by arranging the superimposed surfaces. Materials and Methods: A mandibular right first molar from a dental model was prepared, scanned and fabricated with composites of polyetherketoneketone (PEKK). Master dies were classified into 4 groups. For the conventional method, the impression was taken with polyvinylsiloxane and the impression was poured with Type IV dental stone. For the 3D printing, the standard die was scanned and converted into models using three different 3D printers. Each of four methods was used to make 10 specimens. Scanned files were superimposed with the standard die by using 3D surface matching software. For statistical analysis, Kruskal-Wallis test and Mann-Whitney U test were done (P < 0.05). Results: Compared to the standard model, the volumetric changes of dies fabricated by each method were significantly different except the models fabricated by conventional method and 3D printer of Stereolithography (P < 0.05). The conventional dies showed the lowest volumetric change than 3D printed dies (P < 0.05). 3D printed dies fabricated by Stereolithography showed the lowest volumetric change among the different 3D printers (P < 0.05). Conclusion The conventional dies were more accurate than 3D printed dies, though 3D printed dies were within clinically acceptable range. Thus, 3D printed dies can be used for fabricating restorations.

BACKGROUND: The lateral radiograph-based system described by Tsuyama is used widely to classify ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. However, OPLL is a complex 3-dimensional (3-D) lesion, not a simple and uniplanar one, which is often difficult to identify on a lateral radiograph. Furthermore, its reliability among spine surgeons has not been investigated. Given the popularity of a reconstructed computed tomography (CT), this study examined the inter- and intra-observer reliability of lateral radiograph-based OPLL classification using that modality. METHODS: Five spine surgeons independently reviewed the lateral radiograph, axial CT, 2-D (sagittal) and 3-D reconstructed CT images of 108 OPLL patients on 2 separate occasions. Based on these images, the reviewers classified each OPLL case according to the Tsuyama's system. The kappa values were used to assess the statistical reliability. RESULTS: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images. CONCLUSIONS: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images.
Adult ; Aged ; Cervical Vertebrae/radiography ; Female ; Humans ; Image Processing, Computer-Assisted ; Male ; Middle Aged ; Observer Variation ; Ossification of Posterior Longitudinal Ligament/*classification/*radiography ; *Tomography, X-Ray Computed

In order to investigate the level of anxiety, depression and repression, and the coping style in response to the stress of the delinquent adolescents, we examined 158 delinquent adolescents and 60 student adolescents using anxiety scale, depression scale, repression sensitivity scale and coping scale. Data were processed by IBM PC AT computer using SPSS program and were statistically analyzed by ANOVA. The level of anxiety, depression and repression of delinquent adolescents was significantly higher and the score of maladaptive coping scale was significantly higher than those of student adolescents. In conclusion, delinquent adolescents were more anxious, depressive, repressive, and more maladaptive than student adolescents.
Adolescent* ; Anxiety* ; Depression* ; Humans ; Repression, Psychology*

Nowadays, 3 dimentional (3D) printing, especially Direct Metal Laser Sintering (DMLS) system is used in dentistry. DMLS system has recently been introduced for fabrication metal framework for metal ceramic crowns to overcome the disadvantages of the casting method and computer aided design/computer aided manufacturing (CAD/CAM) milling system. DMLS system uses a high-temperature laser beam to selectively heat a substructure metal powder based on the CAD data with the framework design. A thin layer of the beamed area becomes fused, and the metal framework is completed by laminating these thin layers. Utilizing DMLS system to fabricate fixed prostheses is expected to achieve free-from shaping without mold and limitations from cutting tools, fabricate prostheses with complex geometry, prevent distortion and fabrication defects that inherent to conventional fabrication methods. The purpose of this case report is to demonstrate various fixed prostheses such as long span fixed prostheses, post to achieve satisfactory results in functional and esthetic aspects.
Ceramics ; Crowns ; Dentistry ; Fungi ; Hot Temperature ; Methods ; Printing, Three-Dimensional ; Prostheses and Implants*

BACKGROUND: Coal workers' pneumoconiosis is a fibrotic lung disease resulting from chronic inhalation of coal dust. The precise mechanism of lung fibrosis in coal workers' pneumoconiosis is uncertain. However, a relationship between the stimulation of fibroblast proliferation and collagen production by mediators released from inflammatory and resident lung cells is thought to be a major factor. The transforming growth factor-β(TGF-β), a multifunctional cytokine and growth factor, plays a key role in the scarring and fibrotic processes due to its ability to induce extracellular matrix proteins and modulate the growth and immune function of many cell types. To determine the involvement of TGF-βin the development of lung fibrosis in coal workers' pneumoconiosis, the TGF-β1 level in plasma was measured in patients with coal workers' pneumoconiosis. METHODS: Plasma was collected from 40 patients with coal workers' pneumoconiosis (20 with simple coal workers' pneumoconiosis and 20 with complicated coal workers' pneumoconiosis) and from 10 normal controls. The ELISA method was used to measure the plasma TGF-β1 concentration. RESULTS: Compared to the control group (0.63±0.18 ng/mL), there was no significant difference in the plasma TGF-β1 level in patients with simple coal workers' pneumoconiosis (0.64±0.17 ng/mL) (p>.05). However, in patients with complicated coal workers' pneumoconiosis the plasma TGF-β1 level (0.79±0.18 ng/mL) was significantly higher than in patients with simple coal workers' pneumoconiosis and control group (p<0.05). CONCLUSION: The data suggests that TGF-β1 has some influence in the development of lung fibrosis in coal workers' pneumoconiosis.
Cicatrix ; Coal* ; Collagen ; Dust ; Enzyme-Linked Immunosorbent Assay ; Extracellular Matrix Proteins ; Fibroblasts ; Fibrosis ; Humans ; Inhalation ; Lung ; Lung Diseases ; Plasma* ; Pneumoconiosis* ; Pulmonary Fibrosis