• Transactions of the Korean Society of Automotive Engineers
• /
• v.17 no.5
• /
• pp.91-96
• /
• 2009

The number of vehicles applied diesel engine are rapidly rising for fuel economy. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced emission regulation. The Diesel Particulate Filter (DPF) system is considered as the most efficient method to reduce particulate matter by car makers but also in retrofit market. In this paper we discussed the optimization of active regeneration timing by comparing the fuel consumption from back pressure caused by PM loading and from active regeneration. The effects of back pressure of DPFs during PM loading, active regeneration condition and engine emission(PM) on additional fuel consumption are experimentally investigated and the proper regeneration timings according to DPF systems and fuel loss for 160,000km are determined.

• Development and Reproduction
• /
• v.22 no.3
• /
• pp.245-252
• /
• 2018

To improve survival rates of vitrified pig oocytes, the treatment of cytoskeletal stabilizer on an appropriate time is one of the possible approaches. However, the exact treatment timing and effect of cytoskeletal stabilizer such as cytochalasin B (CB) is not well known during oocyte vitrification procedures. Thus, the present study was conducted to determine optimal treatment timing of CB during vitrification and warming procedures. In experiment 1, the survival rates of the postwarming pig oocytes were analyzed by fluorescein diacetate (FDA) assays with 4 classifications. In results, post-warming oocytes showed significantly (p<0.05) decreased number of alive oocytes (31.8% vs. 86.4%) compared to fresh control. In detail, the significant difference (p<0.05) was found only in strong fluorescence (18.2% vs. 70.5%) not in intermediate fluorescence groups (13.6% vs. 15.9%). In experiment 2, CB was treated before (CB-Vitri) and after (Vitri-CB) vitrification. In results, group of Vitri-CB showed significantly (p<0.05) higher (91.6%) survival rates compared to group of CB-Vitri (83.7%), significantly (p<0.05) and comparable with group of Vitri Control (88.7%) by morphological inspection. In FDA assay results, group of Vitri-CB showed significantly (p<0.05) higher (44.2%) survival rates compared to groups of CB-Vitri (36.7%) and Vitri Control (35.1%). In conclusion, the increased survival rates of post-warming pig oocyte treated with Vitri-CB method are firstly described here. The main finding of present study is that the CB treatment during recovery could be helpful to refresh the post-warming pig oocyte resulting its improved survival rates.

• Clinical and Experimental Pediatrics
• /
• v.50 no.9
• /
• pp.841-847
• /
• 2007

Acute liver failure (ALF) is a very rare but devastating illness in children. Specific treatment to recovery is often not available, and the underlying cause of the liver failure is often unknown and diverse especially in children. Liver transplantation has increased the chance of survival; however it needs an optimal timing to reach the best result which is not familiar to pediatrician. This article discusses the current knowledge of the epidemiology, backgrounds and factors to be considered before establishing the treatment of ALF in children.

• Archives of Plastic Surgery
• /
• v.39 no.3
• /
• pp.222-226
• /
• 2012

Background : Immediate breast reconstruction after mastectomy and delayed breast reconstruction with post-supplementary treatment are the two types of breast reconstruction currently performed when treating breast cancer. Post-mastectomy radiation therapy (PMRT) not only reduces local recurrence but also improves overall survival. However, the complications and survival rates associated with PMRT need to be clear when determining the timing of breast reconstruction. Accordingly, we investigated the optimal timing of breast reconstruction by observing patients who underwent mastectomy followed by PMRT, based on their overall health and aesthetic satisfaction. Methods : We retrospectively reviewed 21 patients who underwent breast reconstruction with PMRT between November 2004 and November 2010. We collected data regarding the various methods of mastectomy, and the modality of adjuvant therapy, such as chemotherapy, hormone therapy, and radiotherapy. Telephone interviews were conducted to study the general and aesthetic satisfaction. Results : Patients who received PMRT after breast reconstruction showed a greater complication rate than those undergoing breast reconstruction after PMRT (P=0.02). Aesthetic satisfaction was significantly higher in the groups undergoing breast reconstruction after PMRT (P=0.03). Patients who underwent breast reconstruction before PMRT developed complications more frequently, but they expressed greater aesthetic satisfaction with the treatment. Conclusions : It is recommended that the complication rates and aesthetic satisfaction after breast reconstruction be carefully considered when determining the optimal timing for radiotherapy.

• Food Science and Preservation
• /
• v.10 no.3
• /
• pp.381-387
• /
• 2003

‘Fuji’ apples were treated by gamma irradiation (0 - 3 kGy) or methyl bromide fumigation at commercial conditions (MeBr, 26 g/kg, 4 hr) for quarantine purposes at two different treatment timing after harvest and stored under air at 0$^{\circ}C$ for 4 months. Associated with the treatment timing of irradiation or fumigation, after 40 days of storage at 0$^{\circ}C$ following harvest was more adequate than immediately after harvest in keeping qualities of stored apples. However, more than 2 kGy irradiation and MeBr fumigation were detrimental to physiological and chemical qualities of the fruits. These results show that less than 1 kGy irradiation at the delayed timing has a possibility to be applied as a quarantine procedure without significant changes in the quality of apples.

• Clinics in Orthopedic Surgery
• /
• v.10 no.4
• /
• pp.448-454
• /
• 2018

Background: Traumatic spinal cord injury (SCI) is a tragic event that has a major impact on individuals and society as well as the healthcare system. The purpose of this study was to investigate the strength of association between surgical treatment timing and neurological improvement. Methods: Fifty-six patients with neurological impairment due to traumatic SCI were included in this study. From January 2013 to June 2017, all their medical records were reviewed. Initially, to identify the factors affecting the recovery of neurological deficit after an acute SCI, we performed univariate logistic regression analyses for various variables. Then, we performed a multivariate logistic regression analysis for variables that showed a p-value of < 0.2 in the univariate analyses. The Hosmer-Lemeshow test was used to determine the goodness of fit for the multivariate logistic regression model. Results: In the univariate analysis on the strength of associations between various factors and neurological improvement, the following factors had a p-value of < 0.2: surgical timing (early, < 8 hours; late, 8-24 hours; p = 0.033), completeness of SCI (complete/incomplete; p = 0.033), and smoking (p = 0.095). In the multivariate analysis, only two variables were significant: surgical timing (odds ratio [OR], 0.128; p = 0.004) and completeness of SCI (OR, 9.611; p = 0.009). Conclusions: Early surgical decompression within 8 hours after traumatic SCI appeared to improve neurological recovery. Furthermore, incomplete SCI was more closely related to favorable neurological improvement than complete SCI. Therefore, we recommend early decompression as an effective treatment for traumatic SCI.

• Journal of Gastric Cancer
• /
• v.9 no.3
• /
• pp.128-135
• /
• 2009

Purpose: The aim of this study was to compare synchronous and metachronous hepatic metastases in patients with gastric cancer to determine clinicopathologic features and differences in prognosis as a function of the timing of the metastasis and the treatment modality rendered. Materials and Methods: Sixty-seven patients who were diagnosed with gastric cancer metastatic to the liver and treated at the Hanyang University Hospital between June 1992 and December 2006 were retrospectively analyzed to study the pertinent clinicopathologic features and effect of treatment methods. Results: There was a significant difference with respect to lymphatic (P=0.041) and vascular invasion (P=0.036) in comparing the clinicopathologic features between the patients with synchronous and metachronous hepatic metastases. The 1-year survival rate and median survival time of patients with gastric cancer and liver metastases were 38.9% and 9.2 months in the entire patient cohort, 30.9% and 9.2 months in the synchronous group, and 44.5% and 9.7 months in the metachronus group, respectively (P=0.436). The group of patients undergoing local treatment (such as surgery and radiologic intervention) followed by systemic chemotherapy, the group of patients receiving systemic chemotherapy only, and the untreated group of patients were compared, and there was no difference between the synchronous and metachronous groups. The synchronous and metachronous groups had high survival rates with local treatment. Conclusion: In patients with gastric cancer and liver metastases, there was no difference in prognosis based on the timing of the hepatic metastases. Independent of the timing of hepatic metastasis, aggressive treatment, such as surgery and radiologic intervention, may help improve the prognosis.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.47 no.3
• /
• pp.235-247
• /
• 2020

The purpose of this study was to evaluate the skeletal and dentoalveolar effects and optimal timing for treatment of class II malocclusion with functional appliances in children and adolescents. A group of 30 patients with class II malocclusion were divided into 3 groups according to their use of functional appliance: Twin block, Activator, Fränkel appliance. The group was also divided into 2 groups according to the cervical vertebrae maturation method. Lateral cephalometric radiographs were analyzed pretreatment (T0) and posttreatment (T1). Among the functional appliances, treatment with Twin block and Activator showed significant increase in the length of the mandible (Co-Gn) and the lower anterior facial height (ANS to Me), whereas the overjet and overbite were significantly reduced. Treatment with Fränkel appliance showed significant improvement in the relationship of maxilla and mandible. In addition, if the functional appliance was used during the period of pubertal growth peak, there was a significant increase in mandibular length, improvement in the relationship of maxilla and mandible, labial inclination of lower incisors and decrease in overjet compared to the treatment before pubertal growth peak. Therefore, this study indicates that using functional appliances for patients with class II malocclusion is effective and the optimal timing for using functional appliances is during pubertal growth peak.

• Journal of Yeungnam Medical Science
• /
• v.28 no.1
• /
• pp.31-44
• /
• 2011

Background: The optimal timing of treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKI) in NSCLC patients has not yet been determined. Methods: We separated 228 patients with advanced /metastatic NSCLC treated with gefitinib into an early gefitinib group (patients who received gefitinib as first- or second-line treatment) and a delayed gefitinib group (patients who received gefitinib as third or fourth-line treatment) and attempted to determine whether the timing of gefitinib treatment affected clinical outcomes. Results: Median overall survival (OS), progression free survival (PFS), and median OS from first-line treatment of advanced/metastatic disease (OSt) for 111 patients in the early gefitinib group were 6.2 months, 3.3 months, and 11.6 months. However, median OS, PFS, and OSt for 84 patients in the delayed gefitinib group were 7.8 months, 2.3 months, and 22.7 months. No differences in OS and PFS were observed between the 2 groups. However, OSt was significantly longer in the delayed gefitnib group. Timing of gefitinib therapy was one of the independent predictors of OSt. Hb ${\geq}$ 10 g/dl, and having never smoked, and ECOG performance status ${\leq}1$ were independent predictors of better PFS. Conclusion：Deferral of gefitinib therapy in patientswith advanced ormetastatic NSCLC may be preferable if they are able to tolerate chemotherapy.

• The Korean Journal of Health Service Management
• /
• v.8 no.1
• /
• pp.151-164
• /
• 2014

This study was conducted to investigate the effect of timing of surgery on outcomes of spine operated patients for lumbar herniated intervertebral disc. The research design was cohort study and based on the data of claims for the medical expenses of health insurance. 21,475 cases who had primary spine surgery between January 1, and December 31, 2003, observed to conservative treatment period in the past two years from preoperative primary diagnosis to timing of primary surgery. According to one and five year follow up monitoring, the probability of occurrence of reoperation was not statistically significant with preoperative duration of symptom. Also one year follow up, the probability of occurrence of complication, was not statistically significant with preoperative duration of symptom. But five year follow up, groups who had one to two month preoperative duration of symptom decreased complication rate than less than a month(95%CI:0.594-0.927). Thus, from the onset of symptoms of back pain before primary surgery with enough and adequate time observation is required. Also, medical consumers or providers to choose surgery in determining prudence is required.