• Progress in Medical Physics
• /
• v.24 no.4
• /
• pp.303-314
• /
• 2013

Image quality of computed tomography (CT) is very vulnerable to metal artifacts. Recently, the thickness and background normalization techniques have been introduced. Since they provide flat sinograms, it is easy to determine metal traces and a simple linear interpolation would be enough to describe the missing data in sinograms. In this study, we have developed a theory describing two normalization methods and compared two methods with respect to various sizes and numbers of metal inserts by using simple numerical simulations. The developed theory showed that the background normalization provide flatter sinograms than the thickness normalization, which was validated with the simulation results. Numerical simulation results with respect to various sizes and numbers of metal inserts showed that the background normalization was better than the thickness normalization for metal artifact corrections. Although the residual artifacts still existed, we have showed that the background normalization without the segmentation procedure was better than the thickness normalization for metal artifact corrections. Since the background normalization without the segmentation procedure is simple and it does not require any users' intervention, it can be readily installed in conventional CT systems.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.10
• /
• pp.1648-1654
• /
• 2008

Superoxide dismutase (SOD) removes damaging reactive oxygen species from the cellular environment by catalyzing the dismutation of two superoxide radicals to hydrogen peroxide and oxygen. Extracellular superoxide dismutase (EC-SOD) is a tetramer and is present in the extracellular space and to a lesser extent in the extracellular fluids. Increasing therapeutic applications for recombinant human extracellular superoxide dismutase (rEC-SOD) has broadened interest in optimizing methods for its purification, with a native conformation of tetramer. We describe a solid phase refolding procedure that combines immobilized metal affinity chromatography (IMAC) and gel filtration chromatography in the purification of rEC-SOD from Escherichia coli. The purified rEC-SOD tetramer from the $Ni^{2+}$-column chromatography is refolded in Tris buffer. This method yields greater than 90% of the tetramer form. Greater than 99% purity is achieved with further purification over a Superose 12PC 3.2/30 column to obtain the tetramer and specific activities as determined via DCFHDA assay. The improved yield of rEC-SOD in a simple chromatographic purification procedure promises to enhance the development and therapeutic application of this biologically potent molecule.

• Journal of Chest Surgery
• /
• v.47 no.2
• /
• pp.124-128
• /
• 2014

Background: A closed pleural biopsy is commonly performed for diagnosing patients exhibiting pleural effusion if prior thoracentesis is not diagnostic. However, the diagnostic yield of such biopsies is unsatisfactory. Instead, a thoracoscopic pleural biopsy is more useful and less painful. Methods: We compared the diagnostic yield of needle thoracoscopic pleural biopsy performed under local anesthesia with that of closed pleural biopsy. Sixty-seven patients with pleural effusion were randomized into groups A and B. Group A patients were subjected to closed pleural biopsies, and group B patients were subjected to pleural biopsies performed using needle thoracoscopy under local anesthesia. Results: The diagnostic yields and complication rates of the two groups were compared. The diagnostic yield was 55.6% in group A and 93.5% in group B (p<0.05). Procedure-related complications developed in seven group A patients but not in any group B patients. Of the seven complications, five were pneumothorax and two were vasovagal syncope. Conclusion: Needle thoracoscopic pleural biopsy under local anesthesia is a simple and safe procedure that has a high diagnostic yield. This procedure is recommended as a useful diagnostic modality if prior thoracentesis is non-diagnostic.

• Imaging Science in Dentistry
• /
• v.47 no.2
• /
• pp.123-127
• /
• 2017

Purpose: Obstructive and inflammatory disease often occurs in the major salivary glands, and no predictive treatment has yet been developed for this condition. The aim of this report was to introduce an intraductal irrigation procedure and to illustrate its application to practical patient cases. Materials and Methods: Two patients complaining of pain and swelling in the parotid gland during meals who underwent sialography were diagnosed as having sialodochitis with sialadenitis. Intraductal irrigation was then performed on the parotid gland on the side of the complaint. The irrigation procedure was conducted in the same manner as the sialography procedure, except that saline was used as the filling solution. Symptom severity was evaluated with a numerical rating scale (NRS) at the initial visit and a month after the irrigation. Results: The initial NRS value of patient 1 was 10. The value decreased to 6 and then to 0 after 2 irrigation procedures. The NRS value of patient 2 regarding the symptoms involving the left parotid gland decreased from 4-5 to 1 after 4 irrigation procedures performed at 1-month intervals. Conclusion: Intraductal irrigation of the salivary gland may be a simple, safe, and effective treatment option for patients with obstructive and inflammatory disease of the salivary gland that is capable of resolving their symptoms.

• Journal of the Korean Society for Precision Engineering
• /
• v.7 no.3
• /
• pp.26-36
• /
• 1990

This paper describes the Computer Aided Design (CAD) of dies for direct hot extrusion of structural shapes such as Z's and U's from aluminum alloys. A simple analysis of the direct extrusion process is developed and used to formulate a disign procedure for determining the optimal shape of the extrusion dies. A computer software system has been developed to design flat-faced dies for non-lubricated hot extrusion process. This software is a system of computer programs which are written to logical design procedure. Computer programs are based on empirical and analytical relationships, as well as on established knowledge based system. In the interactive mode of operation, the reaults at various tages of the design process are plotted on a screen. At any stage, the designer can interact with the computer to change or modify the design, based on his experience. The output from the program is (a) the design of the flat-faced die, (b) information on extrusion load, reduction ratio, and other process variables, etc. The implementation of this CAD system is expected to (a) provide scientific basis and rationalize the die design procedure, (b) optimize extrusion variables to maximize yield and production rate, (c) improve utilization of existing press capacity, etc.

• Journal of Trauma and Injury
• /
• v.31 no.1
• /
• pp.12-15
• /
• 2018

Rib fixations for flail chest or displaced rib fractures are not a new technique. However, reports on rib fixations involving costal cartilage fractures are very few and surprisingly there are no reports of internal fixations involving only the costal cartilage in the English literature. The diagnosis is difficult and the necessity of the procedure may be quite controversial. Placing plates in screws into the costal cartilage alone may seem unstable and easily dislodged or stripped through the cartilage. We report a 31-year-old male scuba diver instructor who underwent rib fixations over his 7th and 8th costal cartilage ribs for severe pain. The procedure was done with conventional plates and screws. He had the plates and screws removed 2 months later due to lingering pain, but with them removed he is now quite happy with the results without pain. The procedure for fixation of painful overlapped costal cartilage is quite simple and can be done with the usual conventional methods, fixating plate and screws directly over the cartilage alone without fixation over the bony rib.

• Archives of Plastic Surgery
• /
• v.32 no.2
• /
• pp.262-266
• /
• 2005

In some blepharochalasis patients, upper blepharoplasty alone is not satisfactory because of narrow distance between eyebrow and eyelash. On that occasion, eyebrow lift is advisable. There are many methods of classical eyebrow lift, such as direct excision, transblepharoplasty approach, anterior hairline technique, and so on. But they are not so effective, have a tendency to recur and also give rise to side effects; unacceptable scar, facial nerve palsy, sensory loss and hematoma, etc. Some patients who have prominent nasolabial folds, are reluctant to perform face lift procedure due to psychologic or economic burden. The authors performed the eyebrow lift procedure separately or simultaneously with face lift or forehead lift. After making 2 or 3 slit incisions, we passed absorbable suture material, 3-0 vicryl, through suborbicularis oculi fat layer. Then it was passed through subperiosteal plane and fixated to the temporalis fascia. When patients complain prominent nasolabial folds, malar fat pad was elevated also in the same manner. This methods is effective and has minimal complication such as facial nerve palsy, scar, sensory loss. Recurrent tendency was rarely observed during follow-up. Dimples were observed at slit incision sites but they disappeared within 2 or 3 weeks. Eyebrow lift and malar fat lift by absorbable suture elevation with subperiosteal dissection is a simple and less morbid. Because of its effectiveness and little side effect or complication, this procedure can be a useful method.

• Journal of Multimedia Information System
• /
• v.5 no.3
• /
• pp.201-208
• /
• 2018

High Efficiency Video Coding range extensions (HEVC RExt) is a kind of extension model of HEVC. HEVC RExt was specially designed for dealing the high quality images. HEVC RExt is very essential for studio editing which handle the very high quality and various type of images. There are some problems to dealing these massive data in studio editing. One of the most important procedure is re-encoding and decoding procedure during the editing. Various codecs are widely used for studio data editing. But most of the codecs have common problems to dealing the massive data in studio editing. First, the re-encoding and decoding processes are frequently occurred during the studio data editing and it brings enormous time-consuming and video quality loss. This paper, we suggest new video coding structure for the efficient studio video editing. The coding structure which is called "ultra-low delay (ULD)". It has the very simple and low-delayed referencing structure. To simplify the referencing structure, we can minimize the number of the frames which need decoding and re-encoding process. It also prevents the quality degradation caused by the frequent re-encoding. Various fast coding algorithms are also proposed for efficient editing such as tool-level optimization, multi-serve based distributed coding and SIMD (Single instruction, multiple data) based parallel processing. It can reduce the enormous computational complexity during the editing procedure. The proposed method shows 9500 times faster coding speed with negligible loss of quality. The proposed method also shows better coding gain compare to "intra only" structure. We can confirm that the proposed method can solve the existing problems of the studio video editing efficiently.

• Journal of Korean Society of Transportation
• /
• v.17 no.3
• /
• pp.117-130
• /
• 1999

Earthquakes damage roadway bridges and structures, resulting in significant impacts on transportation system Performance and regional economy. Seismic risk analysis (SRA) procedures establish retrofit priorities for vulnerable highway bridges. SRA procedures use average daily traffic volumes to determine the relative importance of a bridge. This research develops a cost-effective transportation network analysis (TAN) procedure for evaluating numerous traffic flow analyses in terms of the additional system cost due to failure. An important feature of the TNA Procedure is the use of an associative memory (AM) approach in the artificial intelligence held. A simple seven-zone network is developed and used to evaluate the TNA procedure. A subset of link failure system states is randomly selected to simulate synthetic post-earthquake network flows. The performance of different AM model is evaluated. Results from numerous link-failure scenarios demonstrate the applicability of the AM models to traffic flow estimation.

• The Journal of Advanced Prosthodontics
• /
• v.3 no.4
• /
• pp.177-185
• /
• 2011

PURPOSE. The aim of this study was to evaluate the effect of dimensional stability of splinting material on the accuracy of master casts. MATERIALS AND METHODS. A stainless steel metal model with 6 implants embedded was used as a master model. Implant level impressions were made after square impression copings were splinted using 5 different techniques as follows. (1) Splinted with autopolymerizing resin and sectioned, reconnected to compensate polymerization shrinkage before the impression procedure. (2) Splinted with autopolymerizing resin just before impression procedure. (3) Primary impression made with impression plaster and secondary impression were made over with polyether impression material. (4) Splinted with impression plaster. (5) Splinted with VPS bite registration material. From master model, 5 impressions and 5 experimental casts, total 25 casts were made for each of 5 splinting methods. The distortion values of each splinting methods were measured using coordinate measuring machine, capable of recordings in the x-, y-, z- axes. A one-way analysis of variance (ANOVA) at a confidence level of 95% was used to evaluate the data and Tukey's studentized range test was used to determine significant differences between the groups. RESULTS. Group 1 showed best accuracy followed by Group 3 & 4. Group 2 and 5 showed relatively larger distortion value than other groups. No significant difference was found between group 3, 4, 5 in x-axis, group 2, 3, 4 in y-axis and group 1, 3, 4, 5 in z-axis (P<.0001). CONCLUSION. Both Splinting impression copings with autopolymerizing resin following compensation of polymerization shrinkage and splinting method with impression plaster can enhance the accuracy of master cast and impression plaster can be used simple and effective splinting material for implant impression procedure.