• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.153-158
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• 2011

Objective: The aim of this study was to investigate whether anti-M$\ddot{u}$llerian hormone (AMH) levels could be predict ovarian poor/hyper response and IVF cycle outcome. Methods: Between May 2010 and January 2011, serum AMH levels were evaluated with retrospective analysis. Three hundred seventy infertile women undergoing 461 IVF cycles between the ages of 20 and 42 were studied. We defined the poor response as the number of oocytes retrieved was equal or less than 3, and the hyper response as more than 25 oocytes retrieved. Serum AMH was measured by commercial enzymelinked immunoassay. Results: The number of oocytes retrieved was more correlated with the serum AMH level (r=0.781, $p$ <0.01) than serum FSH (r=-0.412, $p$ <0.01). The cut-off value of serum AMH levels for poor response was 1.05 ng/mL (receiver operating characteristic [ROC] curves/area under the curve [AUC], $ROC_{AUC}$=0.85, sensitivity 74%, specificity 87%). Hyper response cut-off value was 3.55 ng/mL $ROC_{AUC}$=0.91, sensitivity 94%, specificity 81%). When the study group was divided according to the serum AMH levels (low: <1.05 ng/mL, middle: 1.05 ng/mL - 3.55 ng/mL, high: >3.55 ng/mL), the groups showed no statistical differences in mature oocyte rates (71.6% vs. 76.5% vs. 74.8%) or fertilization rates (76.9% vs. 76.6% vs. 73.8%), but showed significant differences in clinical pregnancy rates (21.7% vs. 24.1% vs. 40.8%, $p$=0.017). Conclusion: The serum AMH level can be used to predict the number of oocytes retrieved in patients, distinguishing poor and high responders.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.4
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• pp.11-17
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• 2001

In this paper, we propose a polarity decision carrier recovery algorithm for high order QAM(Quadrature Amplitude Modulation), which has robust and large frequency acquisition performance in the high order QAM modem. The proposed polarity decision PD(Phase Detector) output and its variance characteristic are mathematically derived and the simulation results are compared with conventional DD(Decision-Directed) method. While the conventional DD algorithm has linear range of $3.5^{\circ}{\sim}3.5^{\circ}$, the proposed polarity decision PD algorithm has linear range as large as $-36^{\circ}{\sim}36^{\circ}$ at ${\gamma}-17.9$. The conventional DD algorithm can only acquire offsets less than ${\pm}10\;KHz$ in the case of the 256 QAM while an analog front-end circuit generally can reduce the carrier-frequency offset down to only ${\pm}100\;KHz$. Thus, in this case additional AFC or phase detection circuit for carrier recovery is required. But by adopting the proposed polarity decision algorithm, we can find the system can acquire up to ${\pm}300\;KHz$at SNR = 30dB without aided circuit.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.1-9
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• 2011

Hemorrhagic shock is a clinically widespread syndrome characterized by inadequate oxygenation and supply. It is important to diagnose hemorrhagic shock in its early stage for improving treatment effects and survival rate. However, an accurate diagnosis and treatment could be delayed in the early stage of hemorrhagic shock by evaluating only vital signs such as heart rate and blood pressure. There have been many studies for the early diagnosis of hemorrhagic shock, reporting that lactate concentration and perfusion were useful variables for tissue hypoxia and metabolic acidosis. In this study, we measured both perfusion using a laser Doppler flowmeter and lactate concentration from the volume controlled hemorrhagic shock using rats. We also proposed a new shock index which was calculated by dividing lactate concentration by perfusion for early diagnosis. As a result of the survival prediction by the proposed index with the receiver operating characteristic curve method, the sensitivity, specificity, and accuracy of survival were 90.0, 96.7 and 94.0%, respectively. The proposed index showed the fastest significant difference among the other parameters such as blood pressure and heart rate. It could offer early diagnosis and effective treatment for human hemorrhagic shock if it is applicable to humans.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.1
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• pp.47-52
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• 2011

Objective: To determine whether characteristics of sperm motility obtained by computer-assisted sperm analysis (CASA) could predict pregnancy after intrauterine insemination (IUI) in couples with unexplained infertility. Methods: Three hundred eighty-three cycles of intrauterine insemination with superovulation were retrospectively analyzed. Semen analysis was performed with CASA before and after swim-up and the parameters were compared between pregnant and non-pregnant women. Results: The pregnancy rate per cycle was 14.1%. Pregnant and non-pregnant women were comparable in terms of age, infertility duration, the number of dominant follicles. While sperm concentration, motility, and parameters such as average path velocity (VAP) and percentage rapid (RAPID) before semen preparation were significantly different between the pregnancy and non-pregnancy groups, there were no differences in sperm parameters when comparing the two groups after preparation. Using a receiver operating characteristic curve to measure sensitivity and specificity, the optimal threshold value for the predictors of pregnancy was revealed to be a concentration of ${\geq}111{\times}10^6/mL$, a motility of ${\geq}$ 51.4%, and RAPID ${\geq}$ 30.1% before preparation for IUI. Conclusion: Sperm parameters including concentration, motility, and RAPID before sperm preparation could have predictive value for pregnancy outcome after intrauterine insemination with superovulation in couples with unexplained infertility, and would be helpful when counseling patients before they make the decision to proceed with IVF/ICSI-ET.

• Journal of the Korean Solar Energy Society
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• v.39 no.6
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• pp.15-25
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• 2019

As the installation of photovoltaic systems increases, fire accidents of PV system grow every year. Most of PV system fires have been reported to be caused by electrical components. The majority of fire accidents occurred in combiner box, which is presumed to be short-circuit accidents due to dustproof and waterproof failures or heat deterioration of blocking diode. For this reason, the blocking diode installation became optional by revised PV combiner regulation. In this paper, according to the revised regulation, reverse current that generated by voltage mismatch was measured and analyzed in PV array without a blocking diode. The factors that cause voltage mismatch in array are assumed to be shaded PV module and short circuit failure of bypass diode. As the result of experiment, there is no reverse current to flow under shading condition in module, but reverse current flows on the failure of bypass diode in module. According to the module's I-V characteristic curve analysis, open voltage was slightly reduced due to operation of bypass diode in shading. However, it showed that open circuit voltage has decreased significantly in the failure of bypass diode. This indicates that the difference in open voltage reduction of voltage mismatch factor causes reverse current to flow.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.5
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• pp.293-301
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• 2020

Background: The success rate of intubation under direct laryngoscopy is greatly influenced by laryngoscopic grade using the Cormack-Lehane classification. However, it is not known whether grade under direct laryngoscopy can also affects the success rate of nasotracheal intubation using a fiberoptic bronchoscpe, so this study investigated the same. In addition, we investigated other factors that influence the success rate of fiberoptic nasotracheal intubation (FNI). Methods: FNI was performed by 18 anesthesiology residents under general anesthesia in patients over 15 years of age who underwent elective oral and maxillofacial operations. In all patients, the Mallampati grade was measured. Laryngeal view grade under direct laryngoscopy, and the degree of secretion and bleeding in the oral cavity was measured and divided into 3 grades. The time required for successful FNI was measured. If the intubation time was > 5 minutes, it was evaluated as a failure and the airway was managed by another method. The failure rate was evaluated using appropriate statistical method. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were also measured. Results: A total of 650 patients were included in the study, and the failure rate of FNI was 4.5%. The patient's sex, age, height, weight, Mallampati, and laryngoscopic view grade did not affect the success rate of FNI (P > 0.05). BMI, the number of FNI performed by residents (P = 0.03), secretion (P < 0.001), and bleeding (P < 0.001) grades influenced the success rate. The AUCs of bleeding and secretion were 0.864 and 0.798, respectively, but the AUC of BMI, the number of FNI performed by residents, Mallampati, and laryngoscopic view grade were 0.527, 0.616, 0.614, and 0.544, respectively. Conclusion: Unlike in intubation under direct laryngoscopy, in the case of FNI, oral secretion and nasal bleeding had a significant effect on FNI difficulty than Mallampati grade or Laryngeal view grade.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.198-205
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• 2015

Impacts of climate change on aquatic ecosystems range from changes in physiological processes of aquatic organisms to species distribution. In this study, MaxEnt that has high prediction power without nonoccurrence data was used to simulate fish distribution changes in the Geum river watershed according to climate change. The fish distribution in 2050 and 2100 was predicted with RCP 8.5 climate change scenario using fish occurrence data (a total of 47 species, including 17 endemic species) from 2007 to 2009 at 134 survey points and 9 environmental variables (monthly lowest, highest and average air temperature, monthly precipitation, monthly lowest, highest and average water temperature, altitude and slope). The fitness of MaxEnt modeling was successful with the area under the relative operating characteristic curve (AUC) of 0.798, and environmental variables that showed a high level of prediction were as follows: altitude, monthly average precipitation and monthly lowest water temperature. As climate change proceeds until 2100, the probability of occurrence for Odontobutis interrupta and Acheilognathus yamatsuatea (endemic species) decreases whereas the probability of occurrence for Microphysogobio yaluensis and Lepomis macrochirus (exotic species) increases. In particular, five fish species (Gnathopogon strigatus, Misgurnus mizolepis, Erythroculter erythropterus, A. yamatsuatea and A. koreensis) were expected to become extinct in the Geum river watershed in 2100. In addition, the species rich area was expected to move to the northern part of the Geum river watershed. These findings suggest that water temperature increase caused by climate change may disturb the aquatic ecosystem of Geum river watershed significantly.

• Journal of Chest Surgery
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• v.44 no.1
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• pp.44-50
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• 2011

Background: Cardiovascular complications are major causes of morbidity and mortality following non-cardiac thoracic operations. Recent studies have demonstrated that elevation of N-Terminal Pro-B-type natriuretic peptide (NT-proBNP) levels can predict cardiac complications following non-cardiac major surgery as well as cardiac surgery. However, there is little information on the correlation between lung resection surgery and NT-proBNP levels. We evaluated the role of NT-proBNP as a potential marker for the risk stratification of cardiac complications following lung resection surgery. Material and Methods: Prospectively collected data of 98 patients, who underwent elective lung resection from August 2007 to February 2008, were analyzed. Postoperative adverse cardiac events were categorized as myocardial injury, ECG evidence of ischemia or arrhythmia, heart failure, or cardiac death. Results: Postoperative cardiac complications were documented in 9 patients (9/98, 9.2%): Atrial fibrillation in 3, ECG-evidenced ischemia in 2 and heart failure in 4. Preoperative median NT-proBNP levels was significantly higher in patients who developed postoperative cardiac complications than in the rest (200.2 ng/L versus 45.0 ng/L, p=0.009). NT-proBNP levels predicted adverse cardiac events with an area under the receiver operating characteristic curve of 0.76 [95% confidence interval (CI) 0.545~0.988, p=0.01]. A preoperative NT-proBNP value of 160 ng/L was found to be the best cut-off value for detecting postoperative cardiac complication with a positive predictive value of 0.857 and a negative predictive value of 0.978. Other factors related to cardiac complications by univariate analysis were a higher American Society of Anesthesiologists grade, a higher NYHA functional class and a history of hypertension. In multivariate analysis, however, high preoperative NT-proBNP level (>160 ng/L) only remained significant. Conclusion: An elevated preoperative NT-proBNP level is identified as an independent predictor of cardiac complications following lung resection surgery.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.666-680
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• 2006

To obtain basic data for the utilization of saltwort (Salicornia herbacea L.) as a functional ingredient in steamed foam cake, the optimum component ratios for major raw ingredients (saltwort, salt, and wheat flour) as independent variables that affect the product quality were scientifically determined using RSM (response surface methodology) technique. A three-factor and five-level rotational central composite design was used for treatment arrangement. The complete design consisted of 16 experimental points. The three independent variables selected for the RSM experiment were amounts of saltwort (X$_1$, 5${\sim}$25 g), salt (X$_2$, 0${\sim}$10 g), and wheat flour (X$_3$, 470${\sim}$530 g). The optimum responses in specific gravity of the batter and volume, color, texture, and sensory evaluation result of the cake were obtained. The specific gravity and viscosity of the batter at p<0.01 was verified from the regression curve. The characteristic of the batter was influenced by all independent variables, but was extremely dependent on the amount of saltwort ordinary points of the surface responses from the batter formed the minimum points for specific gravities of the batter while viscosities of the batter appeared with the saddle points. Analysis of the response indicated that the amount of saltwort was the most influential factor over the physical properties of the cake, among the dependent variables. Ordinary points of the surface responses from the cake formed the maximum points for loaf volume, hardness gumminess, and chewiness, while Hunter colorimetric parameters appeared with the saddle points. The result indicated that level of the saltwort deviating more or less from the optimal amount decreased the volume and increased the specific gravity with less tender product. Ordinary points of the surface responses of the sensory evaluation scores from the cake formed the maximum points for appearance, flavor, softness, and overall acceptability, while color values appeared with the saddle points. The result also indicated that the level of the saltwort deviating more or less from the optimal amount reduced the preference for the product. Integration of the optimum responses common to all dependent variables that overlapped all the contour maps finally indicated that the combination of 8.3${\sim}$13.8 g saltwort, 2.5${\sim}$6.6 g salt, and 486.5${\sim}$511.5 g wheat flour under the selected preparation recipe optimized the physical and sensory properties in the teamed foam cakes. Practical preparation of the product with median amounts of the ingredients, i.e., 11.0 g saltwort, 4.6 g salt, and 499.0 g wheat flour resulted in similar qualities to the predicted responses. In conclusion, these study results indicated that preparation of steamed foam cake with added saltwort ingredient could potentially produce a more nutritious product with less salt. Further research is required to acquire the optimum levels for sub-ingredients to improve the product quality.

• Gut and Liver
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• v.12 no.6
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• pp.714-721
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• 2018

Background/Aims: Recently reported prognostic models for primary biliary cholangitis (PBC) have been shown to be effective in Western populations but have not been well-validated in Asian patients. This study aimed to compare the performance of prognostic models in Korean patients and to investigate whether inflammation-based scores can further help in prognosis prediction. Methods: This study included 271 consecutive patients diagnosed with PBC in Korea. The following prognostic models were evaluated: the Barcelona model, the Paris-I/II model, the Rotterdam criteria, the GLOBE score and the UK-PBC score. The neutrophil-to-lymphocyte ratio (NLR) was analyzed with reference to its association with prognosis. Results: For predicting liver transplant or death at the 5-year and 10-year follow-up examinations, the UK-PBC score (areas under the receiver operating characteristic curve [AUCs], 0.88 and 0.82) and GLOBE score (AUCs, 0.85 and 0.83) were significantly more accurate in predicting prognosis than the other scoring systems (all p<0.05). There was no significant difference between the performance of the UK-PBC and GLOBE scores. In addition to the prognostic models, a high NLR (>2.46) at baseline was an independent predictor of reduced transplant-free survival in the multivariate analysis (adjusted hazard ratio, 3.74; p<0.01). When the NLR was applied to the prognostic models, it significantly differentiated the prognosis of patients. Conclusions: The UK-PBC and GLOBE scores showed good prognostic performance in Korean patients with PBC. In addition, a high NLR was associated with a poorer prognosis. Including the NLR in prognostic models may further help to stratify patients with PBC.