• Journal of Korean Ophthalmic Optics Society
• /
• v.21 no.3
• /
• pp.281-288
• /
• 2016

Purpose: The present study was aimed to investigate the change of optical quality in fully cured eyes from central serous chorioretionopathy(CSC) and CSC under treatment, respectively. Methods: A total of 136 eyes(68 subjects) was divided into CMC under treatment and its asymptomatic contralateral eye, fully cured eyes after being diagnosed with CMC and its contralateral eye, and normal eyes. Objective scattering index, cut-off value in modulation transfer function, focusing rate, PSF(Point Spread Function) width at 50%, 10% and the contrast sensitivity were measured and analyzed. Results: CMC under treatment showed statistically significant decrease in all evaluations of optical quality compared with asymptomatic contralateral eyes, fully cured eyes and normal eyes. Although there was no significant difference in optical quality between asymptomatic contralateral eyes of CMC under treatment and fully cured eyes, there was tendence in optical quality decreasing compared with normal eyes. Conclusions: From the study, it was revealed that the optical quality was different according to the treatment phase in CMC. The use of optical quality assessment for the decision of complete cure and the evaluation of prognosis in CMC is also proposed.

• Clinical and Experimental Reproductive Medicine
• /
• v.42 no.4
• /
• pp.143-148
• /
• 2015

Objective: The aim of the current study was to determine the predictive value of anti-$M{\ddot{u}}llerian$ hormone (AMH) levels for pregnancy outcomes in patients over 40 years of age who underwent in vitro fertilization or intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) cycles. Methods: We retrospectively analyzed the medical records of 188 women aged 40 to 44 years who underwent IVF/ICSI-fresh ET cycles due to unexplained infertility in the fertility center of CHA Gangnam Medical Center. Patients were divided into group A, with AMH levels <1.0 ng/mL (n=97), and group B, with AMH levels ${\geq}1.0ng/mL$ (n=91). We compared the clinical pregnancy rate (CPR) in the two groups and performed logistic regression analysis to identify factors that had a significant effect on the CPR. Results: The CPR was significantly lower in group A than group B (7.2% vs. 24.2%, p<0.001). In multivariate logistic regression analysis, AMH levels were the only factor that had a significant impact on the CPR (odds ratio, 1.510; 95% confidence interval, 1.172-1.947). The area under the receiver operating characteristic curve for AMH levels as a predictor of the CPR was 0.721. When the cut-off level of AMH was set at 1.90 ng/ mL, the CPR was 6.731-fold higher in the group with AMH levels ${\geq}1.90ng/mL$ than in the group with AMH levels <1.90 ng/mL (p<0.001). Conclusion: Our study showed that AMH levels were predictive of clinical pregnancy in infertility patients over 40 years of age. Further prospective studies should be conducted to validate the predictive capability of AMH levels for the outcome of clinical pregnancy.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.4
• /
• pp.1861-1864
• /
• 2016

Although early diagnosis of thyroid nodule type is very important, the diagnostic accuracy of standard tests is a challenging issue. We here aimed to find an optimal combination of factors to improve diagnostic accuracy for distinguishing malignant from benign thyroid nodules before surgery. In a prospective study from 2008 to 2012, 345 patients referred for thyroidectomy were enrolled. The sample size was split into a training set and testing set as a ratio of 7:3. The former was used for estimation and variable selection and obtaining a linear combination of factors. We utilized smoothly clipped absolute deviation (SCAD) logistic regression to achieve the sparse optimal combination of factors. To evaluate the performance of the estimated model in the testing set, a receiver operating characteristic (ROC) curve was utilized. The mean age of the examined patients (66 male and 279 female) was $40.9{\pm}13.4years$ (range 15- 90 years). Some 54.8% of the patients (24.3% male and 75.7% female) had benign and 45.2% (14% male and 86% female) malignant thyroid nodules. In addition to maximum diameters of nodules and lobes, their volumes were considered as related factors for malignancy prediction (a total of 16 factors). However, the SCAD method estimated the coefficients of 8 factors to be zero and eliminated them from the model. Hence a sparse model which combined the effects of 8 factors to distinguish malignant from benign thyroid nodules was generated. An optimal cut off point of the ROC curve for our estimated model was obtained (p=0.44) and the area under the curve (AUC) was equal to 77% (95% CI: 68%-85%). Sensitivity, specificity, positive predictive value and negative predictive values for this model were 70%, 72%, 71% and 76%, respectively. An increase of 10 percent and a greater accuracy rate in early diagnosis of thyroid nodule type by statistical methods (SCAD and ANN methods) compared with the results of FNA testing revealed that the statistical modeling methods are helpful in disease diagnosis. In addition, the factor ranking offered by these methods is valuable in the clinical context.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.14
• /
• pp.5551-5556
• /
• 2014

Background: The prognostic value of human epidermal growth factor receptor-2 (HER-2/neu) for survival of patients with colorectal cancer (CRC) is still ambiguous. We therefore performed a meta-analysis to evaluate its prognostic significance. Materials and Methods: We searched the MEDLINE and EMBASE databases for published literature investigating associations between HER-2/neu status and overall survival of patients with CRC. A meta-analysis was performed using a DerSimonian-Laird model and publication bias was investigated by Begg's and Egger's tests. Subgroup analysis was also conducted according to the study design type, study quality score, cut-off value for HER-2/neu overexpression, publication region, patient number and publication year. Results: A total of 17 eligible studies involving 2,347 patients were identified for this meta-analysis. The combined hazard ratio (HR) was 1.31 (95% confidence interval (CI): 0.96-1.79), suggesting that HER-2/neu overexpression was not significantly associated with overall survival of patients with CRC. However, subgroup analysis revealed that HER-2/neu overexpression had an unfavorable impact on survival when the analysis was restricted to subgroups of study quality score ${\leq}5 $(HR=1.56, 95%CI: 1.17-2.10), Asian patients (HR=1.74, 95%CI: 1.22-2.49), patient number ${\leq}106$ (HR=1.57, 95%CI: 1.01-2.44), publication year before 2003 (HR=1.59, 95%CI: 1.02-2.49), and prospectively designed study (HR=3.62, 95%CI: 1.42-9.24). The effect disappeared in subgroups of study quality scores > 5 (HR=0.69, 95%CI: 0.33-1.44), non Asian patients (HR=1.14, 95%CI: 0.77-1.70), patients' number > 106 (HR=1.07, 95%CI: 0.67-1.72), publication year after 2003 (HR=1.13, 95%CI: 0.76-1.69), and retrospectively designed study (HR=1.22, 95%CI: 0.89-1.67). Conclusions: Our meta-analysis suggests that HER-2/neu overexpression might not be a significantly prognostic indicator for patients with CRC. Further studies are required to confirm these results.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.1
• /
• pp.68-74
• /
• 1999

The optimum conditions for selective .elimination of salt from tuna boiled extract (TBE) by electrodialysis were determined. The desalination conditions of TBE were determined at various pH's, concentrations and volumes of TBE. The ion-exchange membrane with a molecular weight cut off 100Da was used for desalting of TBE. The desalination times on $1\%$ and $10\%$ of TBE concentrations were 40 min and 240 min, respectively. The electrodialysis process could removed above $95\%$ of the initial salt content in $1\%$ and $10\%$ of TBE concentrations. The desalination of TBE at pH 4.0 was $14\%$ higher than that at pH 9.0 The amount of water transferred by the electrodialysis was determined. The electrodialysis process could remove above $90\%$ of the initial salt content in $5\%$ TBE for 80 min. The initial volume and the permeate did not have significant effects on desalination time and ratio. The key parameters for the desalination of TBE were pH and concentration of TBA.

• The Korean Journal of Nuclear Medicine
• /
• v.31 no.1
• /
• pp.83-89
• /
• 1997

About one-third of radiologically indeterminate solitary pulmonary nodules (SPN) are eventually turned out to be malignant. It is very important to noninvasively determine whether the SPN is malignant or not for the decision of its way of management. PET imaging is highlighted by its unique ability of imaging the function and metabolism of cells. Glucose metabolism is increased in malignant transformed cells. We peformed FDG-PET studies in patients who had radiologically indeterminate SPN and compared the findings with histologic diagnoses to assess the diagnostic accuracy in the detection of malignancy and to decide which parameter is the most suitable for clinical practice among peak SUV (pSUV), average SUV (aSUV), 50/10 ratio, and time-activity curve (TAC), Thirty patients were included in this study and the most useful parameter was pSUV. The sensitivity and specificity in the detection of malignant SPN using 3.5 as a cut off pSUV were both 87%. Interestingly, all 2 false-negative cases were bronch-ioloalveolar carcinoma on histologic examination. If these cases, which could be strongly suspected by CT findings, were excluded, the sensitivity of pSUV was 100%. In conclusion, PET imaging is very helpful for determining malignancy in indeterminate SPN and pSUV is a conveniently measurable parameter which is valuable for interpretation.

• Journal of Trauma and Injury
• /
• v.27 no.4
• /
• pp.133-138
• /
• 2014

Purpose: If the survival of patients suffering from severe blunt trauma is to be improved, appropriate interventions should be taken immediately. The purpose of this study is to evaluate the clinical utility of end-tidal carbon dioxide ($ETCO_2$) as a surrogate marker for predicting both the need for intervention and the prognosis. Methods: This is a prospective observational study. Nasal cannula was applied to measure $ETCO_2$, and the following parameters, which are known to be related to the prognosis for a patient, were recorded: injury severity score (ISS), revised trauma score (RTS), arterial blood gas (ABG), lactate, and hemoglobin (Hb). To evaluate the outcome, we investigated the details of emergent interventions and expired patients. Results: A total of 93 patients were enrolled in this study. Emergent intervention was significantly associated with systolic blood pressure (sBP, p-value=0.001), $ETCO_2$ (p-value<0.001), serum lactate level (p-value<0.001), pH (p-value< 0.003), $HCO_3$ (p-value=0.004), base excess (p-value<0.002), ISS (p-value<0.001) and RTS (p-value=0.005). In the multivariate logistic regression, only $ETCO_2$ (odds ratio (OR): 0.897, 95% confidence interval (CI): 0.792-0.975, p-value= 0.048) and ISS (OR: 1.132, 95% CI: 1.053-1.233, p-value=0.002) were associated with emergent intervention whereas $ETCO_2$ (p-value=0.973) and ISS (p-value=0.511) were not statistically significant in predicting the survival of patients in the univariate analysis. An optimal ETCO cut-off of 29 mmHg on the ROC curve was determined, with the area under the ROC curve (AUC) being 0.824 (0.732-0.917)]. Conclusion: This study has revealed that $ETCO_2$, which can be rapid and easily measured through a nasal cannula, and the ISS may be prognostic indicators of emergent interventions in Emergency Departments.

• Journal of Sensor Science and Technology
• /
• v.12 no.2
• /
• pp.66-71
• /
• 2003

Pt/AlGaN Schottky-type UV photodetectors were designed and fabricated. A low-temperature AlGaN interlayer buffer was grown between the AlGaN and GaN film in the diode structure epitaxy to obtain crack-free AlGaN active layers. A comparison was then made of the structural, electrical, and optical characteristics of two different diodes: one with an AlGaN($0.5\;{\mu}m$)/n+-GaN(2 nm) structure (type 1) and the other with an AlGaN($0.5\;{\mu}m$)/AlGaN interlayer($150\;{\AA}$)/n+-GaN($3\;{\mu}m$) structure(type 2). A crack-free AlGaN film was obtained by the insertion of a low-temperature AlGaN interlayer with an aluminum mole fraction of 26% into the $Al_xGa_{1-x}N$ layer. The fabricated Pt/$Al_{0.33}Ga_{0.67}N$ photodetector had a leakage current of 1 nA for the type 1 diode and $0.1\;{\mu}A$ for the type 2 diode at a reverse bias of -5 V. For the photoresponse measurement, the type 2 diode exhibited a cut-off wavelength of 300 nm, prominent responsivity of 0.15 A/W at 280 nm, and UV-visible extinction ratio of $1.5{\times}10^4$. Accordingly, the Pt/$Al_{0.33}Ga_{0.67}N$ Schottky-type ultraviolet photodetector with an AlGaN interlayer exhibited superior electrical and optical characteristics and improved UV detecting properties.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.7
• /
• pp.486-493
• /
• 2003

Schottky type A $l_{0.33}$G $a_{0.67}$N ultraviolet photodetectors were fabricated on the MOCVD grown AlGaN/ $n^{＋}$-GaN and AlGaN/AlGaN interlayer/ $n^{＋}$-GaN structures. The grown layers have the carrier concentrations of -$10^{18}$, and the mobilities were 236 and 269 $\textrm{cm}^2$/V.s, respectively. After mesa etching by ICP etching system, the Si3N4 layer was deposited for passivation between the contacts and Ti/AL/Ni/Au and Pt were deposited for ohmic and Schottky contact, respectively. The fabricated Pt/A $l_{0.33}$G $a_{0.67}$N Schottky diode revealed a leakage current of 1 nA for samples with interlayer and 0.1$\mu\textrm{A}$ for samples without interlayer at a reverse bias of -5 V. In optical measurement, the Pt/A $l_{0.33}$G $a_{0.67}$N diode with interlayer showed a cut-off wavelength of 300 nm, a prominent responsivity of 0.15 A/W at 280 nm and a UV-visible extinction ratio of 1.5x$10^4./TEX>.

• Journal of Korean Foot and Ankle Society
• /
• v.23 no.4
• /
• pp.159-165
• /
• 2019

Purpose: This study investigated the recurrence rate after performing hallux valgus correction using scarf and Akin osteotomy, and also identified the correlation and cut-off values of both the preoperative and postoperative radiographic parameters as risk factors for the recurrence of hallux valgus. Materials and Methods: We reviewed 87 hallux valgus patients (122 feet) who received scarf and Akin osteotomy from January 2007 to August 2015. The clinical outcomes were evaluated using the visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) scores. The radiological outcome measures included the hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA) as determined on the serial weight bearing radiographs. Recurrence was defined as more than 20 degrees of HVA noted on the final follow-up radiograph. Those radiological factors associated with recurrence were evaluated and analyzed. Results: The mean follow-up duration was 20.6 months (12.0~46.5 months) and the mean age was 44 years (13~80 years). The VAS and AOFAS scores were significantly improved at the time of the final follow-up (7.0 to 2.0, p<0.001; 78.0 to 92.0, p<0.001; respectively). Significant corrections in the HVA, IMA, and DMAA were obtained (p<0.001). Eleven (9.0%: 11/122) cases experienced recurrent hallux valgus deformity. The postoperative IMA, DMAA and HVA showed significant moderate to strong correlation with HVA at the final follow-up (Pearson correlation coefficient: 0.44, 0.70, and 0.88, respectively; p<0.001). Postoperative HVA>16.7 degrees, postoperative DMAA>13.9 degrees, and postoperative IMA>8.2 degrees showed statistically significant correlation with radiological recurrence at the last follow-up, and the odds ratio of each variable was high in order. Conclusion: Our radiographic results indicated that postoperative HVA>16.7 degrees, postoperative DMAA>13.9 degrees, and postoperative IMA>8.2 degrees can be risk factors for hallux valgus recurrence. These risk factors may be helpful for modifying surgical procedures and preventing the recurrence of hallux valgus.