Publications by authors named "Chun-Il Kim"

As the design and scalable technology development of tough, yet stiff, polymer nanocomposites receive attention in the automotive industry, fundamental understating of underlying toughening mechanisms at the nanoscale is inevitable. However, mechanical tests on rubber-toughened nanocomposites have shown that their overall fracture properties are significantly smaller than theoretical predictions. Our previous study showed that major factors in this regard are the simultaneous operation of different toughening mechanisms and the nanostructural features of the interface.

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Nanocomposite technologies can be significantly enhanced through a careful exploration of the effects of agglomerates on mechanical properties. Existing models are either overly simplified (e.g.

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The interface plays a crucial role in the physical and functional properties of polymer nanocomposites, yet its effects have not been fully recognized in the setting of classical continuum-based modeling. In the present study, we investigate the roles of interface and interfiber interactions on the toughening effects of rubber nanofibers embodied in thermoplastic-based materials. Emphasis is placed on establishing comprehensive theoretical and atomistic descriptions of the nanocomposite systems subjected to pull-out and uniaxial extension in the longitudinal and transverse directions.

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The bending resonance of micro-sized resonators has been utilized to study adsorption of analyte molecules in complex fluids of picogram quantity. Traditionally, the analysis to characterize the resonance frequency has focused solely on the mass change, whereas the effect of interfacial tension of the fluid has been largely neglected. By observing forced vibrations of a microfluidic cantilever filled with a series of alkanes using a laser Doppler vibrometer (LDV), we studied the effect of surface and interfacial tension on the resonance frequency.

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Respiratory protection is key in infection prevention of airborne diseases, as highlighted by the COVID-19 pandemic for instance. Conventional technologies have several drawbacks (i.e.

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We study the morphology of lipid membranes subjected to intra-membrane viscous flows and interactions with elliptical cylinder substrates. From the non-linear theory of elastic surfaces, a linearized shape equation and admissible boundary conditions are formulated in elliptical coordinates via the Monge representation of a surface. In particular, the intra-membrane viscosity terms are linearized and mapped into elliptic coordinates in order to accommodate more general forms of viscous flow.

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An ex vivo heart perfusion device preserves the donor heart in a warm beating state during transfer between extraction and implantation surgeries. One of the current challenges includes the use of rigid and noncompliant plastic tubes, which causes injuries to the heart at the junction between the tissue and the tube. The compliant and rapidly strain-stiffening mechanical property that generates a "J-shaped" stress-strain behavior is necessary for producing the Windkessel effect, which ensures continuous flow of blood through the aorta.

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We present a linear theory of lipid membranes which accommodates the effects of intra-membrane viscosity into the model of deformations. Within the Monge parameterization, a linearized version of the shape equation describing membrane morphology is derived. Admissible boundary conditions are taken from the existing non-linear model but reformulated and adopted to the present framework.

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Purpose: Update and reanalysis of our experience of active surveillance (AS) for prostate cancer (PCa) in Korea.

Materials And Methods: A prospective, single-arm, cohort study was initiated in January 2008. Patients were selected according to the following criteria: Gleason sum ≤6 with single positive core with ≤30% core involvement, clinical stage≤T1c, prostate-specific antigen (PSA)≤10 ng/mL, and negative magnetic resonance imaging (MRI) results.

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Purpose: To evaluate prospectively the role of prostate-specific antigen (PSA) density in predicting Gleason score upgrading in prostate cancer patients eligible for active surveillance (T1/T2, biopsy Gleason score≤6, PSA≤10 ng/mL, and ≤2 positive biopsy cores).

Materials And Methods: Between January 2010 and November 2013, among patients who underwent greater than 10-core transrectal ultrasound-guided biopsy, 60 patients eligible for active surveillance underwent radical prostatectomy. By use of the modified Gleason criteria, the tumor grade of the surgical specimens was examined and compared with the biopsy results.

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Introduction: This study was conducted to investigate the relationships between the effect of sunitinib and immature microvessels which are not covered by pericytes.

Materials And Methods: This study involved 29 patients with clear-cell renal cell carcinoma (RCC) who took sunitinib after radical nephrectomy or biopsy due to metastatic RCC. Associations among clinicopathological factors, responses to sunitinib, and patient survival were reviewed.

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Purpose: This study was conducted to describe our early experience with active surveillance (AS).

Materials And Methods: Between January 2008 and December 2012, 35 patients were treated with AS. Selection criteria included the following: Gleason score ≤6 with single positive core, clinical stage ≤T1c, prostate-specific antigen (PSA) ≤10 ng/mL, and unremarkable imaging results.

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Purpose: The utility of the expression of glucose-regulated protein 78 (GRP78) in the evaluation of prognosis depends on the type of tumor. Hence, we aimed to examine the impact of expression of GRP78 and Bcl-2, which are used in the existing prognostic evaluation of ureter tumors, in the evaluation of recurrence and survival rates of ureter tumors.

Materials And Methods: In 53 patients who had undergone radical nephroureterectomy for a ureter tumor from March 2002 to March 2012, age, sex, T stage, nuclear grade, bladder recurrence, and survival rate were analyzed at the time of the patient's surgery depending on the extent of immunohistochemical expression of GRP78 and Bcl-2.

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Purpose: A ureter obstruction caused by a ureteral stone results in inflammatory changes in the proximal submucosal layer and prevents the spontaneous passage of the ureteral stone. Accordingly, we analyzed the relationship between the spontaneous passage rates of ureteral stones less than 8 mm in size and serum C-reactive protein (CRP) levels and neutrophil percentages.

Materials And Methods: A total of 187 patients who were diagnosed with ureteral stones less than 8 mm in size and were managed consecutively at Keimyung University Dongsan Medical Center from January 2001 to January 2011 were retrospectively analyzed.

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Purpose: We compared the effects of alpha-adrenergic receptor blocker (α-blocker) monotherapy with those of combination therapy with α-blocker and 5-alpha-reductase inhibitor (5-ARI) on benign prostatic hyperplasia (BPH) progression for over 10 years.

Materials And Methods: A total of 620 patients with BPH who received α-blocker monotherapy (α-blocker group, n=368) or combination therapy (combination group, n=252) as their initial treatment were enrolled from January 1989 to June 2000. The incidences of acute urinary retention (AUR) and BPH-related surgery were compared between the two groups.

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Objective: To survey cases of benign prostatic hyperplasia (BPH) among patients visiting urologists with lower urinary tract symptoms (LUTS) at general hospitals in Korea and to investigate treatment outcomes in current clinical practice.

Methods: This was a multicenter, prospective study conducted in 18 urology centers in Korea. The symptoms of BPH were observed via the International Prostate Symptoms Score (IPSS), transrectal ultrasonography, uroflometry, prostate, specific, antigen, PSA) and postvoid residual volume at the baseline, 1 week, 4 weeks, 12 weeks, 24 weeks, and 52 weeks after initial evaluation.

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Purpose: A great variety of studies on preoperative serum testosterone as a predictor of progression of prostate cancer have been reported recently. The purpose of this study was to investigate the relationship of preoperative serum testosterone levels in patients who underwent radical prostatectomy with prognostic factors.

Materials And Methods: Clinical data were collected from 60 patients who underwent radical prostatectomy.

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Purpose: We evaluated the correlation between the expression of CXCR4 and prognostic factors in patients with prostate cancer.

Materials And Methods: A total of 57 patients who had undergone surgery for prostate cancer were enrolled. Specimens were obtained before any treatment and were stained with antihuman CXCR4 antibody.

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Purpose: To evaluate the efficacy and tolerability of tamsulosin 0.4 mg once daily in Korean patients with symptomatic benign prostatic hyperplasia (BPH) and investigate whether tamsulosin 0.4 mg can improve symptoms in patients with refractory lower urinary tract symptoms (LUTS) who were previously receiving tamsulosin 0.

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Purpose: We aimed to verify the current status of transurethral resection of the prostate (TURP) in Korea.

Materials And Methods: The medical records of 1,341 men who underwent TURP in 9 Korean medical centers between 2004 and 2008 were reviewed. The patients were divided into two groups according to time periods: 2004-2005 (group 1) and 2006-2008 (group 2).

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Purpose: We analyzed the impact of immediate intravesical mitomycin C instillation after transurethral resection of the bladder (TURB) on tumor recurrence and progression in patients with periodic mitomycin C instillation.

Materials And Methods: Between June 2000 and June 2006, a retrospective study was performed in a total of 115 patients with primary bladder tumors receiving a 6-week course of mitomycin C instillation after TURB. The patients were assigned to two groups: 53 patients in the immediate mitomycin C (I-MMC) group were treated by immediate instillation of mitomycin C after TURB and periodic instillation (6 times, 1 time per week), and 62 patients in the MMC group received only periodic instillation.

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Purpose: We investigated the correlations between the expression of claudin-1 and claudin-7 in clear cell renal cell carcinoma (clear cell RCC) and clinical parameters.

Materials And Methods: The subjects of this study were 119 patients with confirmed clear cell RCC between January 2000 and December 2007. Their RCC tissues were immunohistochemically stained for claudin-1 and claudin-7.

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Purpose: We evaluated the long-term effects of loxoprofen on nocturia in patients with benign prostatic hyperplasia (BPH).

Materials And Methods: Between January 2006 and December 2008, 40 BPH patients with 2 or more episodes of nocturia received an alpha-blocker, 5-alpha reductase inhibitor, and a single dose of 60 mg of loxoprofen at night before sleep for 12 months (Group I). During the same period, 38 BPH patients selected as the control group received an alpha-blocker and 5-alpha reductase inhibitor (Group II).

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Purpose: This study was performed to investigate the relationship between cyclooxygenase-2 (COX-2) expression and apoptosis/angiogenesis in inflammatory and noninflammatory benign prostatic hyperplasia (BPH) and prostate cancer (PC).

Materials And Methods: This study involved 64 BPH and 57 PC patients. The BPH histopathologies were classified by the presence of chronic inflammation as follows: noninflammatory BPH (NI-BPH; n=23) and inflammatory BPH (I-BPH; n=41).

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Objective: To analyze the relationship between serum prostate-specific antigen (PSA) and body mass index (BMI) according to age in a population of ostensibly healthy Korean men.

Patients And Methods: Between 2002 and 2006, data from 13,025 men who visited health promotion centers were evaluated. All men underwent anthropometric measurements and serum PSA determination.

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