• Wind and Structures
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• v.35 no.6
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• pp.419-430
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• 2022

In wind-resistant designs, wind velocity is assumed to be a Gaussian process; however, local complex topography may result in strong non-Gaussian wind features. This study investigates the non-Gaussian wind features over complex terrain under atmospheric turbulent boundary layers by the large eddy simulation (LES) model, and the turbulent inlet of LES is generated by the consistent discretizing random flow generation (CDRFG) method. The performance of LES is validated by two different complex terrains in Changsha and Mianyang, China, and the results are compared with wind tunnel tests and onsite measurements, respectively. Furthermore, the non-Gaussian parameters, such as skewness, kurtosis, probability curves, and gust factors, are analyzed in-depth. The results show that the LES method is in good agreement with both mean and turbulent wind fields from wind tunnel tests and onsite measurements. Wind fields in complex terrain mostly exhibit a left-skewed Gaussian process, and it changes from a softening Gaussian process to a hardening Gaussian process as the height increases. A reduction in the gust factors of about 2.0%-15.0% can be found by taking into account the non-Gaussian features, except for a 4.4% increase near the ground in steep terrain. This study can provide a reference for the assessment of extreme wind loads on structures in complex terrain.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.168-172
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• 2021

Acquired digital fibrokeratoma is very a rare, benign, fibrous, and hyperkeratotic skin tumor that develops most frequently on the finger or toe. The tumor usually occurs in adults as a solitary, dome-shaped lesion. Sometimes, it appears as a rudimentary supernumerary digit and may be misdiagnosed as an accessory nail (double nail) or verruca vulgaris. The pathophysiology of an acquired digital fibrokeratoma is unknown. On the other hand, trauma has often been proposed as a predisposing factor for an acquired type of digital fibrokeratoma. This paper reports a case of trauma-related acquired digital fibrokeratoma presenting as a supernumerary digit and nail in a 36-year-old male. This case is presented with a 0.5 cm×0.4 cm×1.3 cm sized, firm, hyperkeratotic, protruding mass over the left second finger nail.

• Clinical and Experimental Pediatrics
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• v.65 no.5
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• pp.262-268
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• 2022

Background: The delayed diagnosis of developmental dysplasia of the hip (DDH) requires complex treatment and sometimes progresses to hip osteoarthritis. Purpose: This study aimed to evaluate the risk factors and screening time for DDH in preterm infants. Methods: A total of 155 preterm infants with a gestational age <32 weeks screened for DDH with ultrasonography were enrolled in this retrospective chart review. Results: The incidence of DDH was 6.45% (10 of 155). Gestational age, birth weight, sex ratio, and breech presentation did not differ significantly between infants treated for DDH (n=10) and nontreated infants (n=145) (gestational age, 29.2±1.4 weeks vs. 29.6±2.0 weeks, P=0.583; birth weight, 1,240±237 g vs. 1,295±335 g, P=0.607; female sex, 7 of 10 (70.0%) vs. 77 of 145 (53.1%), P=0.346; and breech presentation, 5 of 10 (50.0%) vs. 43 of 145 (29.7%), P=0.286, respectively). Performing the first ultrasonography earlier than 38 weeks of postmenstrual age (PMA) increased the risk of an abnormal finding by 3.76 times compared to performing it at ≥38 weeks of PMA. These abnormal findings on ultrasonography resolved spontaneously. Breech presentation increased the risk of minor abnormal findings on the first ultrasonography by 3.11 times versus nonbreech presentation and resolved spontaneously. DDH in preterm infants did not occur predominantly on the left side or in infants born with breech presentation. Conclusion: Performing ultrasonography screening earlier than 38 weeks of PMA caused unnecessary subsequent ultrasonography and overtreatment. Breech presentation was not a risk factor for DDH in preterm infants. However, breech presentation could increase the risk of minor abnormal findings at the 1st ultrasonography compared to nonbreech presentation, which resolved spontaneously. The etiology and risk factors for DDH in preterm infants are somewhat different from those for DDH in term infants.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1264-1264
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• 2001

The affect of surface temperatures of fruits on spectrum which measures actual sugar contents was observed. PLSR was applied to develop the sugar content evaluation system that was not affected by temperature. The reflected spectrum was used at the wavelengths of 654 and 1052nm with the separation distance of 2.5nm. To increase the conformance of a model using unknown samples, let the minimum value of PRESS be an optimum factor. 71 Shingo pears stored in a refrigerator were left in a room temperature for a while and these temperatures and reflected spectrums were measured. Reflected spectrums were measured at the wavelengths of 654 and 1052nm, 3 samples in one second. To measure these at different temperatures, the experiment was repeated hourly and four times. Starting temperatures of 2-3 were increased up to 17. The total number of measured spectrum was 284. To develop a sugar content evaluation system model using measured reflected spectrum, three groups of samples were considered. First group had 51 samples at 14 and second group had 141 samples with lower or higher temperatures than 14. Third group had 155 samples with well distributed temperatures. Other samples were used as validations to ensure the conformance. Measuring the sugar contents of samples with surface temperatures other than 14 were difficult with PLS model I, developed by using a sample temperature of 14. If the sugar contents were compensated using samples' temperatures, results of prediction would be close to the expected results and it would be one of the most important factors to develop this system. PLS models I and II could compensate the temperature but the precision would not come up to the standard. High precision was expected by using samples with wide ranges of temperatures and sugar contents. Both models showed the possibility of an improvement of a sugar content evaluation system disregarding the temperature. For practical use of a system, selecting samples should be done carefully to reduce the effect of the temperature.

• Journal of Chest Surgery
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• v.56 no.5
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• pp.295-303
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• 2023

Background: The use of Adriamycin (ADR), also known as doxorubicin, as a chemotherapy agent is limited by its detrimental adverse effects, especially cardiotoxicity. Recent studies have emphasized the crucial role of angiotensin II (Ang-II) in the development of ADR-induced cardiomyopathy. This study aimed to explore the potential cardioprotective effects of losartan in a rat model of ADR-induced cardiomyopathy. Methods: Male Sprague-Dawley rats were randomly divided into 3 groups: a control group (group C), an ADR-treated group (ADR 5 mg/kg/wk for 3 weeks via intraperitoneal injections; group A), and co-treatment of ADR with losartan group (same dose of ADR and losartan; 10 mg/kg/day per oral for 3 weeks; group L). Western blot analysis was conducted to demonstrate changes in brain natriuretic peptide, collagen 1, tumor necrosis factor (TNF)-α, interleukin-6, matrix metalloproteinase (MMP)-2, B-cell leukemia/lymphoma (Bcl)-2, Bcl-2-associated X (Bax), and caspase-3 protein expression levels in left ventricular (LV) tissues from each group. Results: Losartan administration reduced LV hypertrophy, collagen content, and the expression of pro-inflammatory factors TNF-α and MMP-2 in LV tissue. In addition, losartan led to a decrease in the expression of the pro-apoptotic proteins Bax and caspase-3 and an increase in the expression of the anti-apoptotic protein Bcl-2. Moreover, losartan treatment induced a reduction in the apoptotic area compared to group A. Conclusion: In an ADR-induced cardiomyopathy rat model, co-administration of ADR with losartan presented cardioprotective effects by attenuating LV hypertrophy, pro-inflammatory factors, and apoptosis in LV tissue.

• Journal of Oral Medicine and Pain
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• v.47 no.1
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• pp.27-37
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• 2022

Purpose: This study aimed to broaden our understanding of the predisposing factor and treatment of dislocation by analyzing and evaluating the morphology of the articular eminence (AE) in subjects with temporomandibular joint (TMJ) dislocation using cone beam computed tomography (CBCT). Methods: The subjects were divided into two groups: dislocation (31 subjects) and control (32 subjects). CBCT was used to examine 126 TMJs in 63 subjects (26 males, 37 females). The height, width, and posterior slope of the AE were measured in the parasagittal plane. The posterior slope was measured using the "top-roof line angle (TR angle)" method and the "best-fit line angle (BF angle)" method. The AE on the left side (AEL) and the AE on the right side (AER) of the subjects in the dislocation group were separately analyzed and compared with the control group after taking measurements. The average value of both sides was used when comparing with subjects with bilateral dislocation. Results: Dislocations were more frequent in females (67.7%) than in males (32.3%). The dislocation group showed a gentler TR angle than the control group in the AER and in the average of AE on the both sides (AEB). The same group also showed a wider AE in the AEL and the AER (p<0.05). In subjects with unilateral dislocation, the width of the AE with dislocation was narrower and the TR angle and BF angle was steeper than the other side without dislocation (p<0.05). Conclusions: In subjects with unilateral TMJ dislocation, the posterior slope of the AE is steeper, and the width is narrower at the site of dislocation compared to the site without dislocation. However, in subjects with bilateral TMJ dislocation, AEB were wider, and the mean value of the posterior slope of AEB was gentler than that of the control group.

• Journal of Yeungnam Medical Science
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• v.40 no.2
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• pp.187-192
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• 2023

Background: This study aimed to present the short- and midterm outcomes after complete atrioventricular canal defect (CAVC) repair using a single-patch technique. Methods: This study included 30 children who underwent surgical correction of the CAVC using a single-patch technique. Results: The median age of the patients was 5.7 months (interquartile range [IQR], 5.0-7.5 months), and 23 patients (76.7%) had type A CAVC. Fourteen patients (46.7%) were female and 17 (56.7%) had been diagnosed with Down syndrome. The in-hospital mortality rate was 0%. No deaths were observed during a median follow-up of 4 years (IQR, 3.5-5.0 years). Patients without Down syndrome were associated with late moderate mitral regurgitation (MR) (p=0.02). Late MR less than moderate degree was observed in 96.6%, 78.5%, and 50% of patients after 2, 4, and 5 years of follow-up, respectively, while late tricuspid valve regurgitation less than moderate degree was observed in 96.7%, 85.9%, and 59.0% of patients after 2, 4, and 6 years of follow-up, respectively. After a median follow-up of 4 years, only one patient had required surgical repair of a left ventricular outflow tract obstruction, which occurred 26 months after the first operation. Multivariable logistic regression analysis adjusted for the type of CAVC, sex, Down syndrome, age, and weight revealed that the absence of Down syndrome was a risk factor for late moderate MR (MR-2) (odds ratio, 0.05; 95% confidence interval, 0.006-0.50; p=0.01). Conclusion: A single-patch technique for CAVC surgical repair is a safe method with acceptable short- and midterm results.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.4
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• pp.345-356
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• 2023

This study aimed to assess the effects of exogenous hydrogen sulfide (H₂S) on abdominal aorta coarctation (AAC) induced myocardial fibrosis (MF) and autophagy in rats. Forty-four Sprague-Dawley rats were randomly divided into control group, AAC group, AAC + H₂S group, and H₂S control group. After a model of rats with AAC was built surgically, AAC + H₂S group and H₂S group were injected intraperitoneally with H₂S (100 µmol/kg) daily. The rats in the control group and the AAC group were injected with the same amount of PBS. We observed that H₂S can improve left ventricular function and the deposition of myocardial collagen fibers, inhibit pyroptosis, down-regulate the expression of P-eif2α in myocardial tissue, and inhibit cell autophagy by activating the phosphatidylinositol 3-kinase (PI3K)/AKT1 signaling pathway (p < 0.05). In addition, angiotensin II (1 µM) H9c2 cardiomyocytes were injured in vitro experiments, and it was also observed that pyroptosis was inhibited after H₂S (400 µmol/kg) intervention, the expression of P-eif2α in cardiomyocytes was significantly down-regulated, and the PI3K/AKT1 signaling pathway was activated at the same time. Therefore, increasing the expression of P-eif2α reverses the activation of the PI3K/AKT1 signaling pathway by H₂S. In conclusion, these findings suggest that exogenous H₂S can ameliorate MF in rats with AAC by inhibiting pyroptosis, and the mechanism may be associated with inhibiting the phosphorylation of eif2α and activating the PI3K/AKT1 signaling pathway to inhibit excessive cell autophagy.

• Journal of Digestive Cancer Research
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• v.5 no.1
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• pp.23-27
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• 2017

Although laparoscopic pancreaticoduodenectomy (LPD) is considered as minimally invasive surgery, an advanced level of laparoscopic skill is still required. LPD comprises various procedures including reconstruction. Therefore, establishment of a safe approach at each step is needed. Prevention of intraoperative bleeding is the most important factor in safe completion of LPD. The establishment of effective retraction methods is also important at each site to prevent vascular injury. I also recommend the "uncinate process first" approach during initial cases of LPD, in which the branches of the inferior pancreaticoduodenal artery are dissected first, at points where they enter the uncinate process. This approach is performed at the left side of the superior mesenteric artery (SMA) before isolating the pancreatic head from the right aspect of the SMA, which allows safe dissection without bleeding. Safe and reliable reconstruction is also important to prevent postoperative complications. Laparoscopic pancreatojejunostomy requires highly skilled suturing technique. Pancreatojejunostomy through a small abdominal incision, as in hybrid-LPD, facilitates reconstruction. In LPD, the surgical view is limited. Therefore, we must carefully verify the position of the pancreaticobiliary limb. A twisted mesentery may cause severe congestion of the pancreaticobiliary limb following reconstruction, resulting in severe complications. We must secure the appropriate position of the pancreaticobiliary limb before starting reconstruction. We describe the incidence of intraoperative and postoperative complications and appropriate technique for safe performance of LPD.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.2
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• pp.133-136
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• 2023

Purpose: Prolactin in the blood is separated into three types, and over 90% of prolactin presents as a double monomer (23 KDa). Rarely, it can exist in the size of big prolactin (150 KDa), which is called macroprolactin and is known as an autoantibody complex. When macroprolactin accounts for more than 60% of prolactin in the blood, it is called macroprolactinemia. The presence of such macroprolactin was first reported in a patient with hyperprolactinemia but without typical symptoms. Macroprolactinemia is emerging as an important cause of idiopathic hyperprolactinemia. The polyethylene glycol (PEG) precipitation method using the property of precipitating large-molecular-weight proteins is simple and recently has been widely used as a screening test. The results are in good agreement with the results of gel chromatography. The purpose of this study was to confirm the measurement method and reference value verification of monomeric prolactin in blood prolactin using the PEG precipitation method. Materials and Methods: For 40 examinees who visited the Gangnam Center of Seoul National University Hospital in 2021, the prolactin level was verified using radioimmunoassay (RIA). For macroprolactinemia PEG precipitation method, 25% PEG (molecular weight 6000kDa) solution and serum were mixed in equal amounts in a test tube, then left at room temperature for 20 minutes and centrifuged at 4℃ for 30 minutes (1500g). The prolactin level was measured in the supernatant. Results : After confirming that more than 90% of the 40 tested samples within the reference range <25 ng/mL, the same value as the reference value for prolactin was applied. Since the concentration of monomeric prolactin in serum from which macroprolactin has been removed from blood is diluted 1:1 with PEG, our laboratory is currently reporting the result by multiplying the result by a dilution factor of 2. Conclusion: Radioimmunoassay using PEG precipitation method using the property of precipitating large molecular weight proteins is simple and effective for quantitative measurement of monomeric prolactin in blood prolactin.