Publications by authors named "Jae Kyun Kim"

As a renewable energy from biomass, isobutanol is considered as a promising alternative to fossil fuels. To biotechnologically produce isobutanol, strain development using industrial microbial hosts, such as Escherichia coli, has been conducted by introducing a heterologous isobutanol synthetic pathway. However, the toxicity of produced isobutanol inhibits cell growth, thereby restricting improvements in isobutanol titer, yield, and productivity.

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Background: The lignocellulosic biomass feedstocks such as empty fruit bunches (EFBs) prove to be potential renewable resources owing to their abundance, low prices, and high carbohydrate contents. Generally, the conversion of lignocellulosic biomass into chemicals, fuels, and materials mainly includes pretreatment, enzymatic hydrolysis, fermentation, and recovery of final products. To increase the economic viability of such processes, the cost of cellulase production and enzymatic hydrolysis should be reduced.

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Purpose: Cigarette smoking (CS) is one of the major risk factors of cerebral atherosclerotic disease, however, its level of contribution to extracranial and intracranial atherosclerotic stenosis (ECAS and ICAS) was not fully revealed yet. The purpose of our study was to assess the association of CS to cerebral atherosclerosis along with other risk factors.

Materials And Methods: All consecutive patients who were angiographically confirmed with severe symptomatic cerebral atherosclerotic disease between January 2002 and December 2012 were included in this study.

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Background: To compare pain, tolerability, and complications associated with fine needle aspiration (FNA) versus core needle biopsy (CNB).

Methods: FNAs were performed using 23-gauge needles and CNBs were performed using 18-gauge double-action spring-activated needles in 100 patients for each procedure. Patients were asked to record a pain score using a 10-cm visual analog scale and procedure tolerability.

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Background And Objective: Changes in cerebral blood flow (CBF) immediately after cigarette smoking (CS) are still unclear. Our purpose was to evaluate the hemodynamic changes in each intracranial vessel after CS by using quantitative magnetic resonance angiography (MRA).

Material And Methods: Fifteen healthy male smokers less than 45 years old with more than 3 pack-year smoking history were enrolled in this study.

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Background: In patients undergoing active surveillance of papillary thyroid microcarcinoma, definitive therapy-usually preceded by a definitive diagnostic procedure-is not recommended until evidence of disease progression is obtained, as stated in the American Thyroid Association guidelines. This is because the deferring of definitive diagnosis and therapy until disease progression has no impact on the disease-specific survival. This study evaluated the malignancy rate and probability of thyroid nodules, which was further stratified based on the size cutoff value of 1 cm, with suspicious findings on ultrasonography (US), by using various malignant stratification systems.

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Recently developed flow diverters, such as the pipeline embolization device (PED), allow for safe and efficacious treatment of giant intracranial aneurysms, with high occlusion rates and a low incidence of complications. However, incomplete obliteration after PED treatment may lead to aneurysm regrowth and delayed rupture. Herein, we report a case of a partially thrombosed giant aneurysm of the cavernous internal carotid artery that showed progressive recanalization at 1-3 months after application of a PED.

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Background: After amputation, the brain is known to be reorganized especially in the primary motor cortex. We report a case to show changes in the corticospinal tract in a patient with serial bilateral transtibial amputations using diffusion tensor imaging. Case Description and Methods: A 78-year-old man had a transtibial amputation on his left side in 2008 and he underwent a right transtibial amputation in 2011.

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Background: The purpose of this study was to evaluate the role of core-needle biopsy (CNB) by comparing the results of CNB and repeat fine-needle aspiration (FNA) for thyroid nodules that are initially read as atypia/follicular lesion of undetermined significance (AUS/FLUS) on FNA.

Methods: Among 2631 initial AUS/FLUS FNA results, 505 consecutive nodules (295 repeat FNAs and 210 CNBs) were retrospectively analyzed. The primary outcome was inconclusive (ie, nondiagnostic or AUS/FLUS).

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Objective: To validate a new risk stratification system for thyroid nodules, the Korean Thyroid Imaging Reporting and Data System (K-TIRADS), using a prospective design.

Materials And Methods: From June 2013 to May 2015, 902 thyroid nodules were enrolled from four institutions. The type and predictive value of ultrasonography (US) predictors were analyzed according to the combination of the solidity and echogenicity of nodules; in addition, we determined malignancy risk and diagnostic performance for each category of K-TIRADS, and compared the efficacy of fine-needle aspiration (FNA) with a three-tier risk categorization system published in 2011.

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Background Although there are many well-known prognostic predictors of medullary thyroid carcinoma (MTC), the ultrasonography (US) findings of MTC have not been sufficiently validated in this regard. Purpose To investigate the US findings of MTC and their relationship with the biological behavior of MTC. Material and Methods The US findings and clinical and pathology records of 123 MTC nodules from 108 patients were retrospectively analyzed at two tertiary referral hospitals.

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Objectives: To present the various complications of ultrasound (US)-guided core needle biopsy (CNB) of thyroid lesions in a large patient series.

Methods: From January 2008 to March 2013, 6,169 patients underwent US-guided CNB of 6,687 thyroid nodules at a single institution. We assessed the number and types of major and minor complications, and evaluated the factors associated with complications.

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Mucoceles are one of the most common benign soft tissue masses of the oral cavity. When they occur in the tongue, the ventral surface is the usual location. Mucoceles at the base of the tongue are extremely rare and must be differentiated from intralingual thyroglossal duct cysts.

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Cardiac myxoma is the most common primary tumor of the heart. It is a rare cause of acute ischemic stroke and commonly not detected until after the stroke. There is no current guideline for the treatment of cardiac myxoma stroke and only a few cases of mechanical thrombectomy have been reported.

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Purpose: To evaluate the influence of different flush methods on transfemoral cerebral angiography (TFCA).

Materials And Methods: This single-blind randomized controlled trial included 50 patients who had undergone TFCA. Balanced block randomization was used to allocate participants into intermittent-flush (n = 25) and continuous-flush (n = 25) groups.

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Objectives: Early detection and diagnosis of metastasis to the thyroid gland is important. This study aims to evaluate the clinical value of core-needle biopsy (CNB) by comparing the results of CNB and fine-needle aspiration (FNA) in patients with clinically suspected metastasis to the thyroid gland.

Study Design: Case series with chart review.

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Background: Although ultrasonography (US) has an essential role in assessing the malignancy risk of thyroid nodules, a malignancy risk-stratification system has not been established. The purpose of this study was to develop a clinically feasible US risk-stratification system--the Thyroid Imaging Reporting and Data System (TIRADS)--primarily based on the solidity and echogenicity of thyroid nodules.

Methods: From January 2010 to May 2011, a total of consecutive 2000 thyroid nodules (≥ 1 cm) with final diagnoses were enrolled from the database of low and high cancer volume institutions (1000 nodules from each institution).

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Background: The aim of this study was to evaluate the role of core-needle biopsy (CNB) as a first-line diagnostic tool for initially detected thyroid nodules.

Methods: This observational study evaluated 632 initially detected thyroid nodules in 632 consecutive patients who underwent CNB between October 2008 and December 2011. CNB results were categorized into the six categories of the Bethesda System.

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Objective: To compare single-session radiofrequency ablation (RFA) and ethanol ablation (EA) for treating predominantly cystic thyroid nodules (PCTNs).

Materials And Methods: This single-blind, randomized trial was approved by the Institutional Review Board of two centers and informed consent was obtained from all patients before enrollment. Fifty patients with a single PCTN (cystic portion less than 90% and greater than 50%) were randomly assigned to be treated by either RFA (25 patients) or EA (25 patients) at two hospitals.

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Purpose: Hypothesizing that the parent artery (PA) diameter of the aneurysm-neck segment is larger than those of normal segments, especially in wide-necked aneurysm cases, we conducted 3D angiographic analyses in wide-necked aneurysm cases focusing on the luminal morphologic change of the PA.

Materials And Methods: Under the approval of local IRB, we enrolled 26 patients with distal internal carotid artery (ICA) aneurysms, which were treated with stent assisted coiling. The PA diameters along the centerline were measured at 6 points with built-in software by two observers.

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Purpose: Diffusion-weighted MR images (DWI) obtained after endovascular treatment of cerebral aneurysms frequently show multiple high-signal intensity (HSI) dots. The purpose of this study was to see whether we could reduce their incidence after embolization of unruptured cerebral aneurysms by modification of our coiling technique, which involves the deliberate aspiration of the microcatheter lumen right after delivery of each detachable coil into the aneurysm sac.

Materials And Methods: From January 2011 to June 2011, all 71 patients with unruptured cerebral aneurysms were treated using various endovascular methods.

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Objective: The incidence and risk factors of microembolic lesions on MR diffusion-weighted imaging (DWI) were analyzed after the endovascular coiling of unruptured intracranial aneurysms (UIAs).

Methods: Data obtained from 271 consecutive patients (70 men and 201 women; median age 57 years; range 23-79 years) who presented with UIA for coil embolization between July 2011 and June 2013 were analyzed. Two independent reviewers examined the DWI and apparent diffusion coefficient maps obtained the following day for the presence of restrictive diffusion spots and counted the number of spots.

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Objective: The accurate diagnosis of thyroid nodules is important for making management decisions. The purpose of this study was to evaluate the feasibility of core-needle biopsy with BRAF(V600E) mutation analysis (CNB + BRAF(V600E) ) and to compare the clinical usefulness of CNB + BRAF(V600E) and fine-needle aspiration with BRAF(V600E) mutation analysis (FNA + BRAF(V600E) ) in the diagnosis of thyroid malignancy.

Design, Patients And Measurements: The results of BRAF(V600E) mutation analyses of 820 nodules from 820 patients (153 men, 667 women; mean age, 51·1 years), who underwent CNB + BRAF(V600E) (n = 256) or FNA + BRAF(V600E) (n = 564) between January 2011 and March 2012 were retrospectively evaluated.

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Objective: To evaluate the diagnostic performance of fine needle aspiration (FNA) and core needle biopsy (CNB) in patients with anaplastic thyroid cancer (ATC) or thyroid lymphoma (TL).

Methods: Between January 2000 and March 2012, 104 patients were diagnosed with ATC or TL by means of ultrasound (US)-guided FNA, CNB, or surgery. This study ultimately included 99 patients with ATC (n = 59) or TL (n = 40).

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