• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.2
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• pp.189-194
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• 2023

Backgrounds/Aims: Postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD) is a source of major morbidity and mortality. Early diagnosis and treatment of POPF is mandatory to improve patient outcomes and clinical risk scores may be ombined with postoperative drain fluid amylase (DFA) values to stratify patients. The aim of this pilot study was to etermine if intraoperative fluid amylase (IFA) values correlate with DFA1 and POPF. Methods: In patients undergoing PD from February to November 2020, intraoperative samples of intra-abdominal fluid adjacent to the pancreatic anastomosis were taken and sent for fluid amylase measurement prior to abdominal closure. Data regarding patient demographics, postoperative DFA values, complications, and mortality were prospectively collected. Results: Data were obtained for 52 patients with a median alternative Fistula Risk Score (aFRS) of 9.9. Postoperative complications occurred in 20 (38.5%) patients (five Clavien grade ≥ 3). There were eight POPFs and two patients died (pneumonia/sepsis). There was a significant correlation between IFA and DFA1 (R² = 0.713; p < 0.001) and DFA3 (p < 0.001), and the median IFA was higher in patients with POPF than patients without (1,232.5 vs. 122; p = 0.0003). IFA > 260 U/L predicted POPF with sensitivity, specificity, positive and negative predictive values of 88.0%, 75.0%, 39.0%, and 97.0%, respectively. The incidence of POPF was 43.0% in high-risk (high aFRS/IFA) and 0% in lowrisk patients (low aFRS/IFA). Conclusions: IFA correlated with POPF and may be a useful adjunct to clinical risk scores to stratify patients during PD. Larger, prospective studies are needed to determine whether IFA has clinical utility.

• The Journal of Engineering Geology
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• v.15 no.3
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• pp.337-348
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• 2005

Jurassic granite from Pocheon area were tested to investigate the effect of microcracks on mechanical properties of the granite. Three oriented core specimens were used for uniaxial compressive tests and each core specimen are perpendicular to the axes'R'(rift plane),'c'(grain plane) and'H'(hardway plane), respectively Among vacious elastic constants, the variation of Poisson's ratio as function of the directions was examined. From the related chart between ratio of failure strength and Poisson's ratio, H-specimen shows the highest range in Poisson's ratio and Poisson's ratio decreases in the order of C-specimen and R-specimen. The curve pattern is nearly linear in stage $I\simIII$ but the slope increases abruptly in stage H-3. As shown in the related chart, diverging point of a curve is formed when ratio of failure strength is $0.92\sim0.96$ Stage IV -3 is out of elastic region. The behaviour of rock in the four fracturing stages was analyzed in term of the stress-volumetric strain me. From the stress increment-volumetric strain equations governing the behaviour of rock, characteristic material constants, a, n, Q, m and $\varepsilon_v^{mcf}$, were determined. Among these, inherent microcrack porosity$(a, 10^{-3})$ and compaction exponent(n) in the microcrack closure region(stage I ) show an order of $a^R(3.82)>a^G(3.38)>a^H(2.32)\;and\;n^R(3.69)>n^G(2.79)>n^H(1.99)4, respectively. Especially, critical volumetric microcrack strain($\varepsilon_v^{mcf}$) in the stage W is highest in the H-specimen, normal to the hardway plane. These results indicate a strong correlation between two major sets of microcracks and mechanical properties such as Poisson's ratio and material constants. Correlation of strength anisotropy with microcrack orientation can have important application in rock fracture studies.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.6
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• pp.59-76
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• 2019

Most technology-based entrepreneurship(TBE) go through an process of decline or disappear without overcoming the valley of death(VoD). The purpose of this study is to identify the growth dimension of TBE and to test the influence of firms activities on firms growth over time. This study identified the two-dimensional growth dimension divided by size and profit through exploratory factor analysis(EFA) of a number of growth indicators. Then, we defined the discrete state of growth firm in four states, divided by size and profit, and five states, including the closure of business. Multi-nomial logit model is used to predict the effect of TBE activities on a discrete state of growth firm(size×profit, closure of business) based on multiple independent variables. The independent variables are based on five representative firms activities: employment, marketing, R&D, financial activities, and general management activities. The growth stage of TBE over time has been categorized into three stages: early stage, middle stage, and late stage of business, taking into account the main periods during which the survival rate of startups sharply decreases. The analytical data of this study was based on the secondary data of the start-up supporting companies of government and public institutions. The subjects of analysis were TBE within 10 years. As a result of the empirical analysis, the employment and marketing activities of TBE show that early and mid-term activities had an effect on the state of firms growth. However, if there is a difference, employment activities have both positive and negative effects, while marketing activities have only a positive effect on size and profit growth. And besides, R&D activities, financial activities, and general management activities throughout the entire process of firms growth were found to be firms activities that have both positive and negative effects on firms growth. In addition, the age of the founder, the firms' industry, and the geographic location of the firms, which are general characteristics of the company, were found to have a distinctive effect on the growth status of the firms according to the growth stage.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.267-272
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• 2008

Purpose: Donor site seroma is the most common complication of extended latissimus dorsi flap for breast reconstruction. One of preventive treatments is to use the fibrin sealant in donor site before closure. Experimentally, it has been used successfully in the prevention of latissimus donor site seroma, but its clinical efficacy and results were very controversial. Thus, the purpose of this study is to evaluate the clinical efficacy and to determine the optimal dose of fibrin sealant. Methods: A retrospective study was done of patients operated under same surgical conditions by one operator with variable doses of fibrin sealant. The study group consisted of 60 consecutive patients who underwent breast reconstruction with extended latissimus flap reconstructions from January 2005 to December 2006. Patients were divided into 4 group by applied fibrin sealant amount(group 1=0 mL, group 2=1 mL, group 3=2 mL, group 4=4 mL). Retrospective data were obtained from total postoperative drainage amount, time from surgery to drain removal, and incidence and quantity of seroma formation in matched patients group. Results: Total drainage amount decreased relative to the amount of fibrin sealant. The seroma formation rate of 30% in the study group 4 was significantly less than group 1 rate of 71%(p<0.05). It was an improvement over the rates of as much as 79% described previously in the literature. Also, time from surgery to drain removal was shortened significantly in group 4 patients(p<0.05). Conclusion: The use of fibrin sealant in the extended latissimus dorsi flap donor site appears effective in preventing seroma. However, important factors to obtain lower seroma formation rates are proper techniques and proper amounts such as the authors suggested amount: $0.01mL/cm^2$ with spray type fibrin sealant.

• Biomedical Science Letters
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• v.13 no.1
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• pp.25-32
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• 2007

The purpose of this study was to investigate the effect of the high voltage pulsed Current (HVPC) stimulation on the healing rate and the proliferative activity of keratinocytes and IGF-I mRNA expression of an incisional wound in rat skin. Twenty male Sprague-Dawley rats ($265{\sim}290g$) were randomly divided into HVPC (n=10) and control group (n=10). Rats received 10 mm length of full-thickness incision wound on the back under the anesthesia. The HVPC group received electrical stimulation with a Current intensity of 50 V at 100 pps for a duration of 30 minutes, while the control group was given the same treatment without electricity for a week. Polarity was negative in first three days and positive thereafter. The wound length was measured and evaluated as percentage. The mean number of nucleolar organizer regions (NORs) per nucleus and level of IGF-I mRNA expression were calculated. The mean percent of wound closure were $51.17{\pm}17.76%$ and $80.71{\pm}11.91%$, respectively, in the sham treated control and HVPC stimulated groups (t=-4.308, P<0.001). The mean NOR number per nucleus of the keratinocytes in the control and HVPC group were $1.85{\pm}0.20$ and $2.70{\pm}0.23$, respectively (t=8.638, P<0.001). The IGF-I mRNA level were $0.76{\pm}0.44$ and $1.32{\pm}0.41$, respectively, in the control and HVPC stimulated wounds (t=2.906, P<0.01). There was a positive correlation between the mean NOR number per nucleus and IGF-l mRNA level with a Pearson product moment correlation coefficient of 0.72 (P<0.05). These findings suggest that the HVPC may activate the rRNA of the basal keratinocytes and upregulate the IGF-I mRNA levels by alteration of the electrical environment, and it may increase proliferative activity of the keratinocytes in the skin wound of the rat.

• Applied Microscopy
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• v.27 no.1
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• pp.71-86
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• 1997

The regeneration and differentiation of the cutaneous pigment system in the goldfish, Carassius auratus during the wound healing process were studied with high magnification electron microscope. The cutaneous pigment cells of the normal tissues were composed of three kinds of dermal chromatophores-xanthophores, leucoiphores and melanophores. While xanthophores contain two kinds of pigment granules-pterinosomes and carotenoid vesicles, leucophores and melanophores contain amorphous pigment granules (leucosomes) and oval shaped electron dense melanin pigment granules (melanosomes) respectively. After injury, primary wound healing responses being carried out by migration of epidermal cells and hemocytes spreading over the wound surface at the day of wounding. And at the time of primary wound closure, 5 to 7 days after wounding, rER rich cells-presumably common precursors of dermal chromatophores-immigrated into the wound area. First redifferentiated chromatophores appeared 3 weeks after wounding. Pigment granules of the chromatophores were emerged from the cytoplasmic Golgi complex via rough endoplasmic reticulum. Pinocytotic vesicles which associated with accumulation of pigment material, appeared only at the inner surface of the chromatophores adhering to the rER rich cells, characteristically. The differentiation of each chromatophore in addition to integumental wound repair were accomplished within 4 weeks after wounding at most cases, however the total numbers and densities of these repaired chromatophores still primitive state. Moreover, It has been revealed that complete repair of chromatophores at wounded tissues from burns requirs more than 3 months in normal environment.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.3
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• pp.233-241
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• 2015

The aim of this study was to determine the bite force and lip closing force in preschool children and to analyze the correlation between these forces by age, height and weight, respectively. Data were obtained from 98 children (56 males, 42 females) ranging from 3 to 6 years of age. The magnitude of the bite force was measured bilaterally corresponding with the 2nd primary molars using a bite force gauge, $GM10^{(R)}$ (Nagano Keiki) and the force of lip closure was measured using LIP DE $CUM^{(R)}$ (Cosmo Instruments). The averages of bite force for boys and girls were 217.69 N and 205.05 N, respectively. The relationship between bite force with age, height, and weight present significant positive correlation (p < 0.001, p < 0.001, and p < 0.001, respectively). The averages of lip closing force for boys and girls were 4.81 N and 4.07 N respectively. The relationship between lip closing force with age, height, and weight present significant positive correlation (p < 0.001, p < 0.001, and p < 0.001, respectively). No significant differences were observed between boys and girls (p > 0.05) in both forces. A significant correlation was observed between lip closing force and bite force (p = 0.002).

• Journal of Chest Surgery
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• v.32 no.4
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• pp.373-378
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• 1999

Background: Minimally invasive technique for various cardiac surgeries has become widely accepted since it has been proven to have distinct advantages for the patients. We describe here the results of our experiences of minimal incision in cardiac surgery. Material and Method: From February 1997 to November 1998, we successfully performed 31 cases of minimally invasive cardiac surgery. Male and female ratio was 17:14, and the patients age ranged from 1 to 75 years. A left parasternal incision was used in 9 patients with single vessel coronary heart disease. A direct coronary bypass grafting was done under the condition of the beating heart without cardiopulmonary bypass support(MIDCAB). Among these, one was a case of a reoperation 1 week after the first operation due to a kinked mammary artery graft. A right parasternal incision was used in one case of a redo mitral valve replacement. Mini-sternotomy was used in the remaining 21 patients. The procedures were mitral valve replacement and tricuspid annuloplasty in 6 patients, mitral valve replacement 5, double valve replacement 2, aortic valve replacement 1, removal of left atrial myxoma 1, closure of atrial septal defect 2, repair of ventricular septal defect 2, and primary closure of r ght ventricular stab wound 1. The initial 5 cases underwent a T-shaped mini-sternotomy, however, we adopted an arrow-shaped ministernotomy in the remaining cases because it provided better exposure of the aortic root and stability of the sternum after a sternal wiring. Result: The operation time, the cardiopulmonary bypass time, the aorta cross-clamping time, the mechanical ventilation time, the amount of chest tube drainage until POD#1, the chest tube indwelling time, and the duration of intensive care unit staying were in an acceptable range. There were two surgical mortalities. One was due to a rupture of the aorta cannulation site after double valve replacement on POD#1 in the mini-sternotomy case, and the other was due to a sudden ventricular arrhythmia after MIDCAB on POD#2 in the parasternal incision case. Postoperative complications were observed in 2 cases in which a cerebral embolism developed on POD#2 after a mini-sternotomy in mitral valve replacement and wound hematoma developed after a right parasternal incision in a single coronary bypass grafting. Neither mortality nor complication was directly related to the incision technique itself. Conclusion: Minimally invasive surgery using parasternal or mini-sternotomy incision can be used in cardiac surgeries since it is as safe as the standard full sternotomy incisions.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.128-136
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• 2006

This study was conducted for developing the stability parameter in uncontrolled landfill by using a biomolecular investigation on the microbial community growing through leachate plume. Landfill J(which is in Cheonan) and landfill T(which is in Wonju) were chosen for this study among a total of 244 closed uncontrolled landfills. It addressed the genetic diversity of the microbial community in the leachate by 165 rDNA gene cloning using PCR and compared quantitative analysis of denitrifiers and methanotrophs with the conventional water quality parameters. From the BLAST search, genes of 47.6% in landfill J, and 32.5% in landfill T, respectively, showed more than 97% of the similarity where Proteobacteria phylum was most significantly observed. It showed that the numbers of denitrification genes, i.e. nirS gene and cnorB gene in the J site are 7 and 4 times higher than those in T site, which is well reflecting from a difference of site closure showing 7 and 13 years after being closed, respectively. In addition, the quantitative analysis on methane formation gene showed that J1 spot immediately bordering with the sources has the greatest number of methane formation bacteria, and it was decreased rapidly according to distribute toward the outer boundary of landfill. The comparative investigation between the number of genes, i.e. nirS gene, cnorB gene and MCR gene, md the conventional monitoring parameters, i.e. TOC, $NH_3-N,\;NO_3-N,\;NO_2-N,\;Cl^-$, alkalinity, addressed that more than 99% of the correlation was observed except for the $NO_3-N$. It was concluded that biomolecular investigation was well consistent with the conventional monitoring parameters to interpret their influences and stability made by leachate plume formed in downgradient around the uncontrolled sites.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.491-499
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• 2015

Purpose: This study was to examine how decline of visual function affects visual perception by assessing visual perception after improving visual function through visual training, and observing the change in the cognitive ability of visual perception. Methods: This study analyzes the visual perceptual evaluation (TVPS_R) of 23 children below age 13($8.75{\pm}1.66$) who have visual abnormalities, and improves visual function after conducting vision training (vision therapy) of the children. Results: Convergence increased from average $3.39{\pm}2.52{\Delta}$ (prism) to $13.87{\pm}6.04{\Delta}$ in the measurement of long-distance disparate points, and from average $5.48{\pm}3.42{\Delta}$ to $18.43{\pm}7.58{\Delta}$ in the measurement of short-distance disparate points. Short-distance diplopia points increased from $25.87{\pm}7.33cm$ to $7.48{\pm}2.87cm$, and as for accommodative insufficiency, short-distance blur points increased from $19.57{\pm}7.16cm$ to $7.09{\pm}1.88cm$. In the visual perceptual evaluation performed before and after improving visual function, 6 items except visual memory showed statistically significant improvement. By order of significant improvement, response gap was highest with $17.74{\pm}16.94$(p=0.000) in visual closure, followed by $15.65{\pm}17.11$(p=0.000) in visual sequential-memory, $13.65{\pm}16.63$(p=0.001) in visual figure-ground, $12.74{\pm}18.41$(p=0.003) in visual form-constancy, $6.48{\pm}10.07$ (p=0.005) in visual discrimination, and $4.17{\pm}9.33$(p=0.043) in visual spatial-relationship. In the visual perception quotient that added up these scores, the response gap was $15.22{\pm}8.66$(p=0.000), showing a more significant result. Conclusions: Vision training enables efficient visual processing and improves visual perceptual ability. It was confirmed that improvement of visual function through visual training not only improves abnormal visual function but also affects visual perception of children such as learning, perception and recognition.