1.Measurements and Comparative Considerations of Velocities of Primary Bloodstain Spatters using a High Speed Camera.
Young Il SEO ; Byung Sun MOON ; Young Jin CHO ; Woo Jeong JEON ; Seong Jin KIM ; Bu Nam SON ; Ki Jeong KIM ; Young Gyu KIM ; Chang Woo CHOO ; Seung Hoon LEE ; Woo Han HONG ; Chae Won LIM ; Jong Hoon LEE ; Kyung Jin RYU ; Je Seol YU ; Yong Seok CHOI ; Nam Kyu PARK
Korean Journal of Legal Medicine 2011;35(1):27-31
Bloodstain pattern analysis is a forensic discipline that reconstruct events of a crime scene by analyzing sizes, shapes, distributions, positions of bloodstains. Bloodstain pattern can be classified into the low velocity, medium velocity, and high velocity system. Velocities in this system represent the velocity of the wounding agent (the force applied) and not to the velocity of the blood in flight. Thus there is no reference system about the velocity of the blood in flight in the existing bloodstain classification system. Applying bloodstain pattern analysis to the real crime case, we needed to have the reference system of velocities of impact spatter, cast-off spatter, and expectorate spatter. Therefore we measured the velocities of these spatters using high speed camera and we analyzed the results. In this experiments the average velocity of impact spatter that generated by swinging a hammer with all experimenter's strength at the pool of blood is about 4.7 times faster than that of swing cast-off spatter that generated by swinging a red-wat hammer with all experimenter's strength, and about 3.9 times faster than that of expectorate spatter that generated by emitting blood from the mouth with all experimenter's strength. The velocities of cast-off spatter and expectorate spatter, however, showed similar distributions. Our experiments that measure the velocities of droplets of blood spatters in flight under the specific conditions that generated at fastest speed can give some reference to the classification system of velocities of bloodstains which is not distinct up to now, as well as some real bloodshed crime cases.
Crime
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Enzyme Multiplied Immunoassay Technique
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Mouth
2.Effects of silanation time on shear bond strength between a gold alloy surface and metal bracket.
Min Ho JUNG ; Won Jun SHON ; Young Seok PARK ; Shin Hye CHUNG
The Korean Journal of Orthodontics 2013;43(3):127-133
OBJECTIVE: We aimed to investigate the effects of silanation time on the shear bond strength (SBS) of metal brackets on gold alloy in a silicoating procedure and compare the SBS of metal brackets on gold alloy and enamel. METHODS: Type III gold alloy plates were sandblasted with 30-microm silicon dioxide. Excess particles were removed with gentle air after silica coating, and silane was applied. Maxillary central-incisor metal brackets were bonded to each conditioned alloy surface with a light curing resin adhesive for 1 s, 30 s, 60 s, or 120 s after applying silane. The brackets were also bonded to 36 upper central incisors with the same adhesive. All samples were cured for 40 s with a light emitting diode curing light. The SBS was tested after 1 h and after 24 h. The adhesive remnant index (ARI) of the samples was also compared. RESULTS: The 60-s and 120-s silanation time groups showed a higher SBS than the other groups (p < 0.05). Samples tested after 24 h showed a significantly higher SBS than did the samples tested after 1 h (p < 0.05). The 1-s group showed higher ARI scores. The one-way analysis of variance and Student-Newman-Keuls test showed that the SBS values of the 60-s and 120-s silanation time groups were not significantly different from the SBS values of enamel. CONCLUSIONS: Adequate silanation time is required to produce sufficient bond strength during silicoating.
Adhesives
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Alloys
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Enzyme Multiplied Immunoassay Technique
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Incisor
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Light
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Silicon Dioxide
3.Effect of infection control barrier thickness on light curing units.
Hoon Sang CHANG ; Seok Ryun LEE ; Sung Ok HONG ; Hyun Wook RYU ; Chang Kyu SONG ; Kyung San MIN
Journal of Korean Academy of Conservative Dentistry 2010;35(5):368-373
OBJECTIVES: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. MATERIALS AND METHODS: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eight-fold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. RESULTS: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). CONCLUSIONS: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.
Diffusion
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Enzyme Multiplied Immunoassay Technique
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Hand
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Humans
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Infection Control
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Light
4.Physical Artifact Correction in Nuclear Medicine Imaging: Normalization and Attenuation Correction.
Jin Su KIM ; Jae Sung LEE ; Gi Jeong CHEON
Nuclear Medicine and Molecular Imaging 2008;42(2):112-117
Artifact corrections including normalization and attenuation correction were important for quantitative analysis in Nuclear Medicine Imaging. Normalization is the process of ensuring that all lines of response joining detectors in coincidence have the same effective sensitivity. Failure to account for variations in LOR sensitivity leads to bias and high-frequency artifacts in the reconstructed images. Attenuation correction is the process of the correction of attenuation phenomenon lies in the natural property that photons emitted by the radiopharmaceutical will interact with tissue and other materials as they pass through the body. In this paper, we will review the several approaches for normalization and attenuation correction strategies.
Artifacts
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Bias (Epidemiology)
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Enzyme Multiplied Immunoassay Technique
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Nuclear Medicine
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Photons
5.The Principles of Intense Pulsed Light and Its Clinical Application.
Hyun Sun PARK ; Bang Soon KIM ; Tae Heung KIM ; Mira CHOI ; Kyu Han KIM
Korean Journal of Dermatology 2010;48(9):735-740
Intense pulsed light (IPL) is a high-intensity pulsed light source emitting polychromatic, non-coherent, and defocused light with a broad wavelength spectrum. However, IPL can similarly work as a conventional laser with the help of variable cut-off filters. It enables selective destruction of target chromophores based upon the theory of selective photothermolysis. Clinicians can combine variable factors including wavelengths, pulse durations, and fluences in IPL systems, which allow great versatility in treating wide ranges of dermatologic diseases and flexibility in optimizing individual treatment parameters according to different skin types or indications. These properties are of great advantage for skilled and experienced clinicians but can be a source of unwanted serious adverse effects for untrained ones at the same time. Therefore, we summarized the basic principles and clinical application of IPL devices to provide the practical guidance. In addition, critical diagnostics, a great deal of experience, and a thorough knowledge of skin pathology and physiology are required for an effective and safe IPL treatment.
Enzyme Multiplied Immunoassay Technique
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Imidazoles
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Light
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Nitro Compounds
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Pliability
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Skin
6.The Measurement of Optimal Power Distance in LEDs.
Mi Kyung PARK ; Beom Joon KIM ; Myeung Nam KIM ; Seog Kyun MUN ; Hyuck Ki HONG ; Yeon Shik CHOI ; Young Chang JO
Korean Journal of Dermatology 2011;49(2):125-130
BACKGROUND: The use of light technology in dermatology has grown rapidly over the last decade, with many developments in its use for the treatment of a wide variety of skin conditions from non-melanoma skin cancers to facial resurfacing for photo-damaged skin. Light-emitting diodes (LEDs) have attracted much attention in medical fields. OBJECTIVE: (1) To assess the optimal distance of 630 nm LEDs (OmniLux(R), (Phototherapeutics Ltd, the UK)) and 830 nm LEDs (Healite(R) (Lutronic, Korea)) for maximum power as determined by a power meter and (2) to apply theory to practical use. METHODS: Two separate hinged planar light emitting diode arrays were studied: 1) the Omnilux Revive(TM) (Phototherapeutics Ltd, the UK), which delivers non-coherent red light at a wavelength of 633+/-3 nm and 2) the Lutronic Healite (Korea), which delivers non-coherent light at a wavelength of 830+/-5 nm. An X93 power meter (Gigahertz-Optik, Germany) was placed against a black background in order to reduce the amount of reflected light. We measured the LED powers over a range of 3~25 cm in 1 cm increments. RESULTS: On the irradiation side of the LED, power increases according to the mass effect of the radiation angle. However, at a certain distance, the power decline effect predominated over the amassment effect. In this respect, the LED light was estimated to be emitted in a reverse V shape. The proper irradiation distance for use in medical fields can thus be determined. CONCLUSION: The proper irradiation distance of LED will be useful and the proper use of LED under the subjects' shape will be done in many medical fields.
Dermatology
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Enzyme Multiplied Immunoassay Technique
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Light
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Skin
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Skin Neoplasms
7.The Effect of Full Spectrum Light Phototherapy for Patients with Tinea pedis.
Wan Ik CHO ; Juhee PARK ; Hye In LEE ; Beom Joon KIM ; Myeung Nam KIM
Korean Journal of Medical Mycology 2010;15(1):12-17
BACKGROUND: Tinea pedis is the most common dermatophytosis which is usually treated by antifungal agent. Recently, there has been a resurgence of interest in potential phototherapy for the local treatment of bacterial and fungal infection. OBJECTIVE: The aim of this study is to evaluate the therapeutic effect of full spectrum light (F.S.L) phototherapy for patients with tinea pedis. METHODS: Lesions were irradiated for 20 minutes, 2 times a week for 4 consecutive weeks with F.S.L. emitting wavelengths from 320 nm to 5000 nm. Clinical symptoms were observed and KOH direct smear and fungal culture were done. RESULTS: Global assessment score was improved after the application of eight sessions of F.S.L phototherapy. 18% of total patient were cleared, 45.4% a marked improvement, 27.3% a mild improvement and 9.1% of patients had no effect. And the fungal exams, KOH direct smear and culture, were conversion to negative in 7 out of 11 patients. Significant adverse effects were not observed. CONCLUSION: F.S.L phototherapy might be another treatment option for the tinea pedis patients.
Enzyme Multiplied Immunoassay Technique
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Humans
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Light
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Phototherapy
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Tinea
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Tinea Pedis
8.Effect of Color of Light Emitting Diode on Development of Fruit Body in Hypsizygus marmoreus.
Myoung Jun JANG ; Yun Hae LEE ; Young Cheol JU ; Seong Min KIM ; Han Mo KOO
Mycobiology 2013;41(1):63-66
This study was conducted to identify a suitable color of light for development of the fruit body in Hypsizygus marmoreus. To accomplish this, samples were irradiated with blue (475 nm), green (525 nm), yellow (590 nm), or red (660 nm) light emitting diodes (LEDs) to induce the formation of fruiting bodies after mycelia growth. The diameter and thickness of the pileus and length of stipes in samples subjected to blue LED treatment were similar to those of subjected to fluorescent light (control), and the lengths of the stipes were highest in response to treatment with the red LED and darkness. The commercial yields of plants subjected to blue and green LED treatment were similar to those of the control. In conclusion, cultivation of H. marmoreus coupled with exposure to blue LED is useful for inducing high quality fruit bodies as well as higher levels of ergosterol, DPPH radical scavenging activity, total polyphenol content and reducing power.
Agaricales
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Darkness
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Enzyme Multiplied Immunoassay Technique
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Ergosterol
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Fruit
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Light
9.Shear bond strength of dentin bonding agents cured with a Plasma Arc curing light.
Youngchul KWON ; Sun Young KIM ; Sae Joon CHUNG ; Young Chul HAN ; In Bog LEE ; Ho Hyun SON ; Chung Moon UM ; Byeong Hoon CHO
Journal of Korean Academy of Conservative Dentistry 2008;33(3):213-223
The objective of this study was to compare dentin shear bond strength (DSBS) of dentin bonding agents (DBAs) cured with a plasma arc (PAC) light curing unit (LCU) and those cured with a light emitting diode (LED) LCU. Optical properties were also analyzed for Elipar freelight 2 (3M ESPE); LED LCU, Apollo 95E (DMT Systems); PAC LCU and VIP Junior (Bisco); Halogen LCU. The DBAs used for DSBS test were Scotchbond Multipurpose (3M ESPE), Singlebond 2 (3M ESPE) and Clearfil SE Bond (Kuraray). After DSBS testing, fractured specimens were analyzed for failure modes with SEM. The total irradiance and irradiance between 450 nm and 490 nm of the LCUs were different. LED LCU showed narrow spectral distribution around its peak at 462 nm whereas PAC and Halogen LCU showed a broad spectrum. There were no significant differences in mean shear bond strength among different LCUs (P > 0.05) but were significant differences among different DBAs (P < 0.001).
Dentin
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Dentin-Bonding Agents
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Enzyme Multiplied Immunoassay Technique
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Light
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Plasma
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Resin Cements
10.The Evaluation of Scattering Effects for Various Source Locations within a Phantom in Gamma Camera.
A Ram YU ; Young Sub LEE ; Jin Su KIM ; Kyeong Min KIM ; Gi Jeong CHEON ; Hee Joung KIM
Korean Journal of Medical Physics 2009;20(4):216-224
(131)I is a radiological isotope being used widely for treatment of cancer as emitting gamma-ray and it is also applied to estimate the function of thyroid for its accumulation in thyroid. However, (131)I is more difficult to quantitate comapred to (99m)Tc, because (131)I has multiple energy gamma-ray emissions compared to (99m)Tc which is a mono energetic gamma-ray source. Especially, scattered ray and septal penetration resulted by high energy gamma ray have a bad influence upon nuclear medicine image. The purpose of this study was to estimate scatter components depending on the different source locations within a phantom using Monte Carlo simulation (GATE). The simulation results were validated by comparing with the results of real experiments. Dual-head gamma camera (ECAM, Chicago, Illinois Siemens) with high energy, general-purpose, and parallel hole collimators (hole radius: 0.17 cm, septal thickness: 0.2 cm, length: 5.08 cm) was used in this experiment. The NaI crystal is 44.5x59.1 cm in height and width and 0.95 cm in thickness. The diameter and height of PMMA phantom were 16 cm and 15 cm, respectively. The images were acquired at 5 different locations of (131)I point source within the phantom and the images of (99m)Tc were also acquired for comparison purpose with low energy source. The simulation results indicated that the scattering was influenced by the location of source within a phantom. The scattering effects showed the same tendency in both simulation and actual experiment, and the results showed that the simulation was very adequate for further studies. The results supported that the simulation techniques may be used to generalize the scattering effects as a function of a point source location within a phantom.
Chicago
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Enzyme Multiplied Immunoassay Technique
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Gamma Cameras
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Gamma Rays
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Illinois
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Nuclear Medicine
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Polymethyl Methacrylate
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Thyroid Gland