• Journal of Korean Foot and Ankle Society
• /
• v.7 no.2
• /
• pp.250-257
• /
• 2003

Purpose: Pilon fracture is caused by high energy and axial compression forces, and it is often associated with severe comminution and soft tissue injury. Recently, limited internal fixation of this fracture may avoid the soft tissue complications associated with formal open reduction and internal fixation and avoid incongruity of joint margin associated with conservative treatment. We have treated Ovadia and Beals type II or III pilon fracture with limited internal fixation and the results were satisfactory. Materials and Methods: We analyzed 15 cases of Ovadia and Beals type II or III fractures who were treated by limited internal fixation(K-wire or screw fixation) from January 1995 to December 2000. The average follow up period was 20 months(range, 12 to 38 months). According to the Ovadia and Beals classification, seven cases were type II, and eight cases were type III. Radiographic results were assessed by Ovadia and Beals criteria. We also assessed the functional results by Mast and Teipner criteria. Results: Radiographic results showed good in 67% and fair in 33% of cases. Clinical results showed good in 73% and fair in 27% of cases. There were no complications such as wound infection and skin necrosis, but traumatic arthritis were 2 cases. Conclusion: Pilon fractures are high energy injuries with significantly associated soft tissue damage and traumatic arthritis. Limited internal fixation offers good solution to Ovadia and Beals type II or III fracture.

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.2
• /
• pp.147-156
• /
• 2006

Statement of problem: The high melting temperature and chemical reactivity of titanium necessitates casting machines different from those used in conventional casting. Despite the new developments in Ti casting systems , inadequate mold filling and internal porosity are frequently observed casting defects. Therefore, the study on the fabrication technique including sprue design to solve these casting defects is still necessary. Purpose: The purpose of this study was to evaluate the effect of sprue design and cross sectional area of sprue on the internal porosity. Materials and methods: 30 simulated cast three units titanium crowns were prepared. 5 cast crowns for each with different sprue design(sinlge sprue, double sprue and plate sprue) of two cross sectional areas (small and large cross sectional areas) were fabricated. The sections of titanium castings were photographed in a microscope at ${\times}100$ magnification to record internal porosities. Results and Conclusion: Within the limits of this study, the following conclusions were drawn: 1. There was a significantly lower in internal porosity of titanium castings for large cross sectional area of sprue group than the small group (P<.05) 2. There was no significant difference in internal porosity among sprue designs in similar cross sectional area of sprue (P>.05).

• Journal of Electrical Engineering and Technology
• /
• v.7 no.6
• /
• pp.959-964
• /
• 2012

Internal pressure of vacuum interrupter (VI) is one of the most important parameters in VI operation and may increase due to the outgassing from the materials inside VI or gas permeation through metal flange or ceramic vessel. The increase of the pressure above a certain level leads to the failures of switching or insulation. Therefore, an effective pressure check of VI is essential and an analysis of partial discharge (PD) characteristics is an effective monitoring method to identify the degree of the internal pressure of VI. This paper introduces a research work on monitoring the internal pressure of VI by analyzing PDs which were measured using a capacitive PD coupler. The authors have developed cost effective capacitive coupler based on the ceramic material that has an excellent insulation properties and the main component of the capacitive coupler is made by SrTiO3. Detectable internal pressure range and distinguishability of the internal pressure of VI were investigated. From the PD tests results, the internal pressure range, from $10^{-2}$ torr to 500 torr, can be monitored by PD measurements using the capacitive coupler and PD inception voltage (PDIV) follows the Paschen's law. In addition, rise time of PD pulse at 13.2kV decreases with the increase of the internal pressure of VI.

• The Journal of Advanced Prosthodontics
• /
• v.13 no.5
• /
• pp.333-342
• /
• 2021

PURPOSE. To evaluate the impact of five different tooth preparation designs on the marginal and internal fit discrepancies of cobalt-chromium (CoCr) crowns produced by computer-aided designing (CAD) and selective laser melting (SLM) processes. MATERIALS AND METHODS. Five preparation data were constructed, after which design crowns were obtained. Actual crowns were fabricated using an SLM process. After the data of actual crowns were obtained with structural light scanning, intaglio surfaces of the design crown and actual crown were virtually superimposed on the preparation. The fit-discrepancies were displayed with colors, while the root means square was calculated and analyzed with one-way analysis of variance (ANOVA), Tukey's test or Kruskal-Wallis test (α = .05). RESULTS. The marginal or internal color-coded images in the five design groups were not identical. The shoulder-lip and sharp line angle groups in the CAD or SLM process had larger marginal or internal fit discrepancies compared to other groups (P < .05). In the CAD process, the mean marginal and internal fit discrepancies were 10.0 to 24.2 ㎛ and 29.6 to 31.4 ㎛, respectively. After the CAD and SLM processes, the mean marginal and internal fit discrepancies were 18.4 to 40.9 ㎛ and 39.1 to 47.1 ㎛, respectively. The SLM process itself resulted in a positive increase of the marginal (6.0 - 16.7 ㎛) and internal (9.0 - 15.7 ㎛) fit discrepancies. CONCLUSION. The CAD and SLM processes affected the fit of CoCr crowns and varied based on the preparation designs. Typically, the shoulder-lip and sharp line angle designs had a more significant effect on crown fit. However, the differences between the design groups were relatively small, especially when compared to fit discrepancies observed clinically.

• Advances in nano research
• /
• v.16 no.2
• /
• pp.111-125
• /
• 2024

Recently, a lot of research has been done on the analysis of axial vibrations of homogeneous and FG nanotubes (nanorods) with various aspects of vibrations that have been fully mentioned in history. However, there is a lack of investigation of the dynamic internal resonances of FG nanotubes (nanorods) between them. This is one of the essential or substantial characteristics of nonlinear vibration systems that have many applications in various fields of engineering (making actuators, sensors, etc.) and medicine (improving the course of diseases such as cancers, etc.). For this reason, in this study, for the first time, the dynamic internal resonances of FG nanorods in the simultaneous presence of large-amplitude size dependent behaviour, inertial and shear effects are investigated for general state in detail. Such theoretical patterns permit as to carry out various numerical experiments, which is the key point in the expansion of advanced nano-devices in different sciences. This research presents an AFG novel nano resonator model based on the axial vibration of the elastic nanorod system in terms of derivation from large-amplitude size dependent internal modals interactions. The Hamilton's Principle is applied to achieve the basic equations in movement and boundary conditions, and a harmonic deferential quadrature method, and a multiple scale solution technique are employed to determine a semi-analytical solution. The interest of the current solution is seen in its specific procedure that useful for deriving general relationships of internal resonances of FG nanorods. The numerical results predicted by the presented formulation are compared with results already published in the literature to indicate the precision and efficiency of the used theory and method. The influences of gradient index, aspect ratio of FG nanorod, mode number, nonlinear effects, and nonlocal effects variations on the mechanical behavior of FG nanorods are examined and discussed in detail. Also, the inertial and shear traces on the formations of internal resonances of FG nanorods are studied, simultaneously. The obtained valid results of this research can be useful and practical as input data of experimental works and construction of devices related to axial vibrations of FG nanorods.

• Journal of Construction Engineering and Project Management
• /
• v.4 no.4
• /
• pp.1-8
• /
• 2014

The broad aim of this paper is to provide a detailed understanding of the post-war problems associated with materials for reconstruction in Libya, and to identify key problems and obstructions. Theoretical and empirical studies are being conducted in Libya. The theoretical study focuses on materials for construction and the key issues such as sources, transport and storage of materials, as well as their impact on the national economy, the nation's socio-economic development and the environment. This empirical study employed questionnaires, observations and a series of interviews with researchers, academics, suppliers and manufacturers, supported by the researcher's three decades of experience of working in the construction industry and its associated processes and operations. The empirical study illustrated that materials for post-disaster reconstruction in Libya suffer from external problems related to policies and decision-making in terms of availability of materials, fluctuation of prices of materials, specifications, building codes, legislation and regulations, and internal problems related to the construction and building material's key players: construction companies, consultancy firms, manufacturers and suppliers.

• Journal of Gastric Cancer
• /
• v.24 no.3
• /
• pp.327-340
• /
• 2024

Purpose: Results of initial endoscopic biopsy of gastric lesions often differ from those of the final pathological diagnosis. We evaluated whether an artificial intelligence-based gastric lesion detection and diagnostic system, ENdoscopy as AI-powered Device Computer Aided Diagnosis for Gastroscopy (ENAD CAD-G), could reduce this discrepancy. Materials and Methods: We retrospectively collected 24,948 endoscopic images of early gastric cancers (EGCs), dysplasia, and benign lesions from 9,892 patients who underwent esophagogastroduodenoscopy between 2011 and 2021. The diagnostic performance of ENAD CAD-G was evaluated using the following real-world datasets: patients referred from community clinics with initial biopsy results of atypia (n=154), participants who underwent endoscopic resection for neoplasms (Internal video set, n=140), and participants who underwent endoscopy for screening or suspicion of gastric neoplasm referred from community clinics (External video set, n=296). Results: ENAD CAD-G classified the referred gastric lesions of atypia into EGC (accuracy, 82.47%; 95% confidence interval [CI], 76.46%-88.47%), dysplasia (88.31%; 83.24%-93.39%), and benign lesions (83.12%; 77.20%-89.03%). In the Internal video set, ENAD CAD-G identified dysplasia and EGC with diagnostic accuracies of 88.57% (95% CI, 83.30%-93.84%) and 91.43% (86.79%-96.07%), respectively, compared with an accuracy of 60.71% (52.62%-68.80%) for the initial biopsy results (P<0.001). In the External video set, ENAD CAD-G classified EGC, dysplasia, and benign lesions with diagnostic accuracies of 87.50% (83.73%-91.27%), 90.54% (87.21%-93.87%), and 88.85% (85.27%-92.44%), respectively. Conclusions: ENAD CAD-G is superior to initial biopsy for the detection and diagnosis of gastric lesions that require endoscopic resection. ENAD CAD-G can assist community endoscopists in identifying gastric lesions that require endoscopic resection.

• The Journal of Internal Korean Medicine
• /
• v.33 no.4
• /
• pp.465-475
• /
• 2012

Objectives : This study was performed to investigate the antineoplastic effect of ethanol extracts from Sanguisorbae Radix on cholangiocarcinoma cells that was established from biliary tract cancer tissue. Materials and Methods : Two cholangiocarcinoma cell lines, SNU-1079 and SNU-1196, were studied. The mRNA expression of Caspase 3, 8, 9, Bcl-2, Bax, P53, and P21 was examined by RT-PCR. Cell viability was determined by MTT assay. The cell cycle was analyzed by flow cytometry and apoptosis by cell death detection ELISA kit. Results : Proliferation of SNU-1079 and SNU-1196 was inhibited by Sanguisorbae Radix treatment in a dose-dependent manner. All cells treated with Sanguisorbae Radix showed increased dose- and time-dependent apoptosis. The expression of caspase 3, 8, 9, p53, and p21 was increased in all cells after the treatment of Sanguisorbae Radix. The expression of Bcl-2 was decreased in SNU-1196 and Bax expression was increased in all cells after the treatment of Sanguisorbae Radix. Conclusions : These results suggest that Sanguisorbae Radix would be beneficial in the treatment of cholangiocarcinoma.

• The Journal of Internal Korean Medicine
• /
• v.32 no.4
• /
• pp.519-529
• /
• 2011

Objectives : This study was performed to investigate the effects of Injinchunggan-tang on cell growth and apoptosis in human hepatic stellate cell line LX2. Materials and Methods : Hepatic stellate cells were treated with various concentrations of Injinchunggan-tang extract for 24, 48 and 72 hours. The extraction was done with distilled water. After the treatment, cell viability, proliferation, apoptosis, caspase activity, caspase inhibitor and the mRNA of the Bcl-2, and Bax with ${\beta}$-actin were measured by using MTT assay, apoptosis assay and RT-PCR. Results : Proliferation, and mRNA expression of the hepatic stellate cells were inhibited by Injinchunggan-tang treatment in a dose-dependent manner. This indicates the prescription has inhibitory effect on fibrogenesis of the liver by regulating the fibrogenesis-associated genes in transcription. Cell viability was inhibited in time- and dose-dependent manners. Conclusions : These results suggest that Injinchunggan-tang would be beneficial in the treatment of cirrhotic patients as well as for the patients with chronic hepatitis.

• The Journal of Internal Korean Medicine
• /
• v.32 no.4
• /
• pp.504-518
• /
• 2011

Objectives : This study was performed to investigate the anti-fibrogenic effect of greater celandine on cultured rat hepatic stellate cells. Materials and Methods : Hepatic stellate cells (HSC-T6) were treated with various concentrations of greater celandine extract for 24, 48, and 72 hours. The extraction was done with distilled water. After the treatment, cell viability, proliferation, mRNA of the ${\alpha}SMA$, TIMP-1, TIMP-2, collagen I ${\alpha}$ 1, MMP-2, IL-6, TGF-${\beta}1$, PDGFr-${\beta}1$, Bcl-2, Bax, Bcl-xl, caspase-3, caspase-9 and the activities of SOD and catalase were measured by using MTT assay, BrdU assay, real-time PCR, superoxide dismutase assay and catalase assay. Results : The viability, proliferation, mRNA expression and synthesis of collagen of the hepatic stellate cells were inhibited as the concentration increased, which indicates the herb has an inhibitory effect on fibrogenesis of the liver by regulating the fibrosis associated genes in transcription. Conclusions : These results suggest that greater celandine would be beneficial in the treatment of fibrotic patients as well as for patients with chronic hepatitis.