• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.40 no.3
• /
• pp.172-180
• /
• 2003

The purpose of this study is to observe the heat transfer process in in-vivo human muscle based on Proton Resonance Frequency(PRF) method in Magnetic Resonance Imaging(MRI). MRI was obtained to measure the temperature variation according to the heat transfer in phantom and in-vivo human calf muscle. A phantom(2% agarose gel) was used in this experiment. MR temperature measurement was compared with the direct temperature measurement using a T-type thermocouple. After heating agarose gel to more than 5$0^{\circ}C$ in boiling hot water, raw data were acquired every 3 minutes during one hour cooling period for a phantom case. For human study heat was forced to deliver into volunteer's calf muscle using hot pack. Reference data were once acquired before a hot pack emits heat and raw data were acquired every 2 minutes during 30minutes. Acquired raw data were reconstructed to phase-difference images with reference image to observe the temperature change. Phase-difference of the phantom was linearly proportional to the temperature change in the range of 34.2$^{\circ}C$ and 50.2$^{\circ}C$. Temperature resolution was 0.0457 radian /$^{\circ}C$(0.0038 ppm/$^{\circ}C$) in phantom case. In vivo-case, mean phase-difference in near region from the hot pack is smaller than that in far region. Different temperature distribution was observed in proportion to a distance from heat source.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.38
• /
• pp.16.1-16.9
• /
• 2016

Background: The association of biomaterial combined with repair factor-like platelet-rich plasma (PRP) has prospective values. Bovine-derived xenograft has been identified as an osteoconductive and biocompatible grafting material that provides osseointegration ability. PRP has become a valuable adjunctive agent to promote healing in a lot of dental and oral surgery procedures. However, there are controversies with respect to the regenerative capacity of PRP and the real benefits of its use in bone grafts. The purpose of this study was to assess the influence of PRP combined with xenograft for the repair of peri-implant bone defects. Methods: Twelve rabbits were used in this study, and the experimental surgery with implant installation was performed simultaneously. Autologous PRP was prepared before the surgical procedure. An intrabony defect (7.0 mm in diameter and 3.0 mm deep) was created in the tibia of each rabbit; then, 24 titanium dental implants (3.0 mm in diameter and 8.5 mm long) were inserted into these osteotomy sites. Thus, a standardized gap (4.0 mm) was established between the surrounding bony walls and the implant surface. The gaps were treated with either xenograft alone (control group) or xenograft combined with PRP (experimental group). After healing for 1, 2, 3, 4, 5, and 6 weeks, the rabbits were sacrificed with an overdose of KCl solution. Two rabbits were killed at each time, and the samples including dental implants and surrounding bone were collected and processed for histological analysis. Results: More newly formed bone and a better bone healing process were observed in control group. The histomorphometric analysis revealed that the mean percentage of bone-to-implant contact in the control group was significantly higher than that of the experimental group (25.23 vs. 8.16 %; P < 0.05, independent-simple t test, analysis of variance [ANOVA]). Conclusions: The results indicate that in the addition of PRP to bovine-derived xenograft in the repair of bone defects around the implant, PRP may delay peri-implant bone healing.

• Archives of Plastic Surgery
• /
• v.38 no.1
• /
• pp.27-34
• /
• 2011

Purpose: Anterolateral thigh (ALT) perforator free flap is commonly used because of its various benefits. The author reports important factors of preoperative and perioperative ALT perforator free flap and causes of failure. Methods: 84 patients who were treated with ALT perforator free flap from December 2004 to 2008, and February 2010 to April 2010 were studied. 61 patients were male and 23 were female. The mean age of patients was 51.1. The main cause was neoplasm and the main reconstructive areas were head and neck area. The size of flap was various from $3{\times}4$ to $12{\times}18$ cm. 6 patients received split thickness skin graft at donor site. Preoperative angiography was checked to all patients. Results: Among the 84 patients, partial necrosis of flaps occurred in 4 patients because of atherosclerosis, varicose vein, or inattention of patient, etc. And total flap necrosis in 5 patients because of abnormal vessels of recipient area or delay of operation, etc. One case of serous cyst was found as the complication of donor area. Two cases of skin graft on donor site were done because of suspected muscle compartment syndrome, 4 cases of that because of large flap. Septocutaneous perforators were found in 7 cases. The author couldn't find reliable perforator in 3 cases, ipsilateral anteromedial thigh perforator and contralateral ALT perforator and latissimus dorsi musculocutaneous free flap were done instead of ALT. There was no case which needed reoperation because of the impairment of blood supply, and 3 cases were revised by leech because of the burn injury by a lamp or venous congestion. Conclusion: Although ALT perforator free flap is widely used with its various merits, many factors such as preoperative condition of donor or recipient area, morphology of defect and operating time need to consider to prevent flap necrosis. And operators should need careful technique because septocutaneous perforator is uncommon, and musculocutaneous perforator is common but difficult to dissect.

• 한국환경농학회:학술대회논문집
• /
• 2009.07a
• /
• pp.329-338
• /
• 2009

Emission of ammonia to the atmosphere are considered a threat to the environment. The application of livestock manure and compost contributes significantly to the emission of ammonia from agriculture. The reduction in NH3 losses from field-applied manure and compost would be a good strategy to reduce national $NH_3$ emission. In this study, various application techniques of liquid manure and compost were compared to evaluate their potential for reducing $NH_3$ emission. In compost application, the reductions in $NH_3$ emission were 70 and 15% for immediately rotary after application (IRA) and rotary at 3-day after application (RA-3d) in comparison with surface application (SA). Total ammonia emissions for 13 days, expressed as % ammonia-N applied in compost, were 42, 35.7, and 12.7% for SA, RA-3d, and IRA treatments, respectively. Mean reductions in NH3 emission from application of liquid pig manure were 26 and 50% for rotary harrow after surface broadcast application in spring and fall, respectively, in comparison with surface broadcast application. Ammonia emission rate was decreased with increasing water content in soil due to dilution effect, but this reduction only was temporary up to 12 hours after application and cumulative $NH_3$ emission was increased with increasing water content in soil. However, the delay would be beneficial because it allows time for rotary hallow of the applied liquid pig manure. Therefor, ammonia emission can be reduced by immediately incorporation of liquid manure and compost after surface application.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.4C
• /
• pp.331-340
• /
• 2006

In this Paper, we propose to extend the TSS-LS(Two-Step Search scheme with Linear search based Second step) scheme which was already proposed by the authors for coherent UWB(Ultra Wide Band) systems, to rapid and reliable acquisition of noncoherent UWB systems in multipath channels. The proposed noncoherent TSS-LS employing simple energy window banks utilizes two different thresholds and search windows to achieve fast acquisition. Furthermore, the linear search is adopted for the second step in the proposed scheme to correctly find the starting point in the range of effective delay spread of the multipath channels, and to obtain reliable BER(Bit Error Rate) performance of the noncoherent UWB systems. Simulation results with multipath channel models by IEEE 802.15.3a show that the proposed two-step search scheme can achieve significant reduction of the required mean acquisition time as compared to general search schemes. ]n addition, the proposed scheme achieves quite good BER performance for large signal-to-noise ratios, which is favorably comparable to the case of ideal perfect timing.

• Archives of Plastic Surgery
• /
• v.36 no.5
• /
• pp.583-590
• /
• 2009

Purpose: In the cases of a vascular compromised condition in an injured lower extremity, soft tissue coverage with free tissue transfer presents a challenging problem to the reconstructive surgeon. For this reason, cross - leg flaps are still used in unusual circumstances. Advances in surgical technique has made the cross - leg free flap possible although it may require long operation time along with significant donor site morbidity. Therefore, a pedicled cross - leg muscle flap may be an alternative treatment modality when local flap or free flap is not possible. Methods: Twelve patients(9 males and 3 females) underwent the operation between October of 2001 and December of 2008. The patients' age ranged from 6 to 82 years. The unusual defects included the regions such as the knee, popliteal fossa, distal third of the tibia, dorsal foot, and the heel. Indications for the cross - leg gastrocnemius flap are inadequate recipient vessels for free flap(in eight cases), extensive soft tissue injuries(in three cases) and free flap failure(in one case). The muscle flap was elevated from contralateral leg and transferred to the soft tissue defect on the lower leg while both legs were immobilized with two connected external fixator systems. Delay procedure was performed 2 weeks postoperatively, and detachment was done after the establishment of the adequate circulation. The average period from the initial flap surgery to detachment was 32 days (3 to 6 weeks). Mean follow - up period was 4 years. Results: Stable coverage was achieved in all twelve patients without any flap complications. Donor site had minimal scarring without any functional and cosmetic problems. No severe complications such as deep vein thrombosis or flap necrosis were noted although mild to moderate contracture of the knee and ankle joint developed due to external fixation requiring 3 to 4 weeks of physical treatment. All patients were able to walk without crutches 3 months postoperatively. Conclusion: Although pedicled cross - leg flaps may not substitute free flap surgery, it may be an alternative method of treatment when free flap is not feasible. Using this modification of the gastrocnemius flap we managed to close successfully soft tissue defects in twelve patients without using free tissue transfers.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.4
• /
• pp.396-402
• /
• 2014

The spring season in Korea features a dynamic landscape with a variety of flowers such as magnolias, azaleas, forsythias, cherry blossoms and royal azaleas flowering sequentially one after another. However, the narrowing of south-north differences in flowering dates and those among the flower species was observed in 2014, taking a toll on economic and shared communal values of seasonal landscape. This study was carried out to determine whether the 2014 incidence is an outlier or a mega trend in spring phenology. Data on flowering dates of forsythias and cherry blossoms, two typical spring flower species, as observed for the recent 60 years in 6 weather stations of Korea Meteorological Administration (KMA) indicate that the difference spanning the flowering date of forsythias, the flower blooming earlier in spring, and that of cherry blossoms that flower later than forsythias was 30 days at the longest and 14 days on an average in the climatological normal year for the period 1951-1980, comparing with the period 1981-2010 when the difference narrowed to 21 days at the longest and 11 days on an average. The year 2014 in particular saw the gap further narrowing down to 7 days, making it possible to see forsythias and cherry blossoms blooming at the same time in the same location. 'Cherry blossom front' took 20 days in traveling from Busan, the earliest flowering station, to Incheon, the latest flowering station, in the case of the 1951-1980 normal year, while 16 days for the 1981-2010 and 6 days for 2014 were observed. The delay in flowering date of forsythias for each time period was 20, 17, and 12 days, respectively. It is presumed that the recent climate change pattern in the Korean Peninsula as indicated by rapid temperature hikes in late spring contrastive to slow temperature rise in early spring immediately after dormancy release brought forward the flowering date of cherry blossoms which comes later than forsythias which flowers early in spring. Thermal time based heating requirements for flowering of 2 species were estimated by analyzing the 60 year data at the 6 locations and used to predict flowering date in 2014. The root mean square error for the prediction was within 2 days from the observed flowering dates in both species at all 6 locations, showing a feasibility of thermal time as a prognostic tool.

• Journal of Yeungnam Medical Science
• /
• v.24 no.1
• /
• pp.41-54
• /
• 2007

Background : The causes of chest pain vary but the leading cause of chest pain is ischemic heart disease. Mortality from ischemic chest pain has increased more than two fold over the last ten years. The purpose of this study was to determine the data necessary for rapid treatment of patients with signs and symptoms of ischemic chest pain in the emergency department (ED). Materials and Methods : We interviewed 170 patients who had ischemic chest pain in the emergency department of Yeungnam University Hospital over 6 months with a protocol developed for the evaluation. The protocol used included gender, age, arriving time, prior hospital visits, methods of transportation to the hospital, past medical history, final diagnosis, and outcome information from follow up. Results : Among 170 patients, there were 118 men (69.4%) and the mean age was 63 years. The patients diagnosed with acute myocardial infarction (AMI) were 106 (62.4%) and with angina pectoris (AP) were 64 (37.6%). The patients who had visited another hospital were 68.8%, twice the number that came directly to this hospital (p<0.05). The ratio of patients who visited another hospital were higher for the AMI (75.5%) than the AP (59.4%) patients (p<0.05). The median time spent deciding whether to go to hospital was 521 minutes and for transportation was 40 minutes. With regard to patients that visited another hospital first, the median time spent at the other hospital was 40 minutes. The total median time spent before arriving at our hospital was 600 minutes (p>0.05). The patients who had a total time delay of over 6 hours was similar 54.8% in the AMI group and 57.9% in the AP group (p>0.05). As a result, only 12.2% of the patients with an AMI received thrombolytics, and 48.8% of them had a simultaneous percutaneous coronary intervention (PCI). In the emergency department 8.5% of the patients with an AMI died. Conclusion : Timing is an extremely important factor for the treatment of ischemic heart disease. Most patients arrive at the hospital after a long time lapse from the onset of chest pain. In addition, most patients present to a different hospital before they arrive at the final hospital for treatment. Therefore, important time is lost and opportunities for treatment with thrombolytics and/or PCI are diminished leading to poor outcomes for many patients in the ED. The emergency room treatment must improve for the identification and treatment of ischemic heart disease so that patients can present earlier and treatment can be started as soon as they present to an emergency room.

• Clinical and Experimental Pediatrics
• /
• v.52 no.11
• /
• pp.1207-1215
• /
• 2009

Purpose:To review and determine the complications in 76 child abuse cases recorded by a multidisciplinary hospital-based child protection team between 1987 and 2007. Methods:We retrospectively reviewed the reports and medical records of child abuse cases maintained by a university hospital-based child protection team. We devised a questionnaire for standardized interviews with the victims' guardians to determine the current physical and mental status of the children; questionnaires were answered by social workers of the child protection team who interviewed the present fosterers of 24 (35.8%) children. Results:Of the 76 children, 6 were infants, 10 were 1-3 years old, were 3-10 years old, and 19 were over 10 years old. Seven children (9.2%) were neglected and 27 (35.5%) and 44 (57.9%) were sexually and physically abused, respectively. In more than half of the cases, the perpetrators were the father or mother of the children. Most children (41 cases, 53.9%) were abused at their homes. The mean follow-up duration from the time of abuse infliction was $54.3{\pm}49.2$ months, and the current mean age of the children was $8.3{\pm}6.4$ years. Moderate and severe developmental delay and physical disability were observed in 6 (25.0%) and 3 (12.5%) cases, respectively. In 13 children (54.2%), the Global Assessment of Functioning Scale (GAF) score was less than 60, which indicates mild mental disability. Conclusion:A hospital-based child protection team may witness the different proportion of abuse types and patterns by conducting a nation-wide survey of child abuse cases.

• Pediatric Infection and Vaccine
• /
• v.17 no.2
• /
• pp.74-82
• /
• 2010

Purpose : The Dipslide culture test is a rapid method for diagnosis of urinary tract infection (UTI). The aim of this study is to determine the diagnostic availability of a urine Dipslide test for evaluation of UTI in febrile children. Methods : Urine specimens from 151 febrile infants were inoculated by a routine blood agar urine culture method and the Dipslide test at the same time. Following incubation for 16-24 hours, the results of the Dipslide test were read at the next visit. Both results of Dipslide and those of routine culture were compared. Results : The mean age of subjects was 15${\pm}$10.6 months. There were 150 infants (99.3%) who had fever with a mean duration of 2.6${\pm}$2.6 days. Thirty two infants (21.2%) were diagnosed as having UTI. Sensitivity and specificity of Uricult Trio CLED medium were 59.4% and 84.8%, respectively. Sensitivity and specificity of Uricult Trio E. coli medium were 60.0% and 96.2%, respectively. The Pearson correlation coefficient between results of Uricult Trio CLED medium and urine culture was 0.438 (P=0.01). Correlation between results of Uricult Trio E. coli medium and urine culture was 0.617 (P=0.01). Conclusion : The Dipslide test requires only 16-24 hours with high specificity in terms of UTI caused by E. coli without the problems associated with specimen delay. This test seems to be helpful for exclusion of UTI in febrile infants and it may reduce unnecessary hospitalization and antibiotic use. However, further studies are required before the product can be recommended as a routine diagnostic tool.