Kwang S. Suh

Korea University, Sŏul, Seoul, South Korea

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Publications (88)311.69 Total impact

  • Ho Seok Lee · Jong Eun Kim · TaeYoung Kim · Kwang S. Suh ·
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    ABSTRACT: We report on a polyol synthesis of highly branched hybrid crystals of Ag and AgCl (Ag:AgCl) using ionic liquid of 1-butyl-3-imidazolium chloride as a precursor and an efficient shape controlling agent. By rationally varying the concentration of ionic liquid, we achieved the control over structure and morphology of Ag:AgCl hybrid crystals in a way to have multi-arms grown from the corners of cubic seed particles. The formation of Ag:AgCl octapods relies on the preferential overgrowth on {1 1 1} facets of cubic seeds, enabled by the selective adsorption of imidazolium-based ionic liquids on {1 1 0} facets. The obtained Ag:AgCl octapods exhibited enhanced photocatalytic activity for degradation of methylene blue under visible light irradiation, compared with those with cubic morphologies.
    Journal of Alloys and Compounds 02/2015; 621:378-382. DOI:10.1016/j.jallcom.2014.09.222 · 3.00 Impact Factor
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    ABSTRACT: High-quality silver (Ag) nanowires with specific dimensions were synthesized by a polyol method with detailed control of the synthesis conditions. For the same amount of AgNO3, the Ag nanowire density became higher as the nanowire diameter decreases and the length increases. This trend was replicated in Ag nanowire films coated on poly(ethylene terephthalate) films and higher densities of Ag nanowires and their junctions were observed in thinner and shorter nanowire networks. Nanowire films with a low sheet resistance (<100 Ω sq−1) and a high transmittance (>90%) resulted from thin, long Ag nanowires. A modified percolation model, which emphasized the importance of the nanowire junction density, was in good agreement with the experimental observations. Meanwhile, long Ag nanowires were found to be undesirable in respect of their uniform coating over a large area. These results offer important design rules of Ag nanowires for highly conductive and transparent nanowire films.
    Acta Materialia 01/2015; 83. DOI:10.1016/j.actamat.2014.09.042 · 4.47 Impact Factor
  • Ho Seok Lee · Jin-Seo Noh · Kwang S Suh ·
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    ABSTRACT: Almost monodisperse, crystalline Bi nanoparticle arrays were synthesized using a newly developed method, magnetically assisted growth of Bi nanoparticles (MAGBINs). The MAGBIN utilizes co-sputtering from Bi and Co targets at an elevated temperature. Crystalline Bi nanoparticles with hexagonal morphology were formed in situ on a Si substrate with a thin surface oxide during this process. The size and density of Bi nanoparticles could be controlled by adjusting the relative powers applied to Bi and Co targets, and they showed opposite trends against the relative powers. Several physical processes such as Co agglomeration, element-selective growth, and Ostwald ripening were proposed to be involved in this Bi nanoparticle growth. The MAGBIN is a facile method to synthesize crystalline Bi nanoparticle arrays, which does not need any chemical agents, complex process, or lithography.
    Nanotechnology 12/2014; 25(49):495605. DOI:10.1088/0957-4484/25/49/495605 · 3.82 Impact Factor
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    ABSTRACT: MicroRNA (miRNA) expression is known to be deregulated in cervical carcinomas. However, no data is available about the miRNA expression pattern for the minimal deviation adenocarcinoma (MDA) of uterine cervix. We sought to detect deregulated miRNAs in MDA in an attempt to find the most dependable miRNA or their combinations to understand their tumorigenesis pathway and to identify diagnostic or prognostic biomarkers. We also investigated the association between those miRNAs and their target genes, especially Notch1 and Notch2. We evaluated miRNA expression profiles via miRNA microarray and validated them using.real-time PCR assays with 24 formalin-fixed, paraffin-embedded tissue blocks of MDA and 11 normal proliferative endocervical tissues as control. Expression for Notch1 and 2 was assessed by immunohistochemistry. MiRNA-135a-3p, 192-5p, 194-5p, and 494 were up-regulated, whereas miR-34b-5p, 204-5p, 299-5p, 424-5p, and 136-3p were down-regulated in MDA compared with normal proliferative endocervical tissues (all P <0.05). Considering the second-order Akaike Information Criterion consisting of likelihood ratio and number of parameters, miR-34b-5p showed the best discrimination power among the nine candidate miRNAs. A combined panel of miR-34b-5p and 194-5p was the best fit model to discriminate between MDA and control, revealing 100% sensitivity and specificity. Notch1 and Notch2, respective target genes of miR-34b-5p and miR-204-5p, were more frequently expressed in MDA than in control (63% vs. 18%; 52% vs. 18%, respectively, P <0.05). MiR-34b-5p expression level was higher in Notch1-negative samples compared with Notch1-positive ones (P <0.05). Down-regulated miR-494 was associated with poor patient survival (P =0.036). MDA showed distinctive expression profiles of miRNAs, Notch1, and Notch2 from normal proliferative endocervical tissues. In particular, miR-34b-5p and 194-5p might be used as diagnostic biomarkers and miR-494 as a prognostic predictor for MDA. The miR-34b-5p/Notch1 pathway as well as Notch2 might be important oncogenic contributors to MDA.
    World Journal of Surgical Oncology 11/2014; 12(1):334. DOI:10.1186/1477-7819-12-334 · 1.41 Impact Factor
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    ABSTRACT: For the first time, highly efficient and flexible polymer light emitting diodes (PLEDs) based on silver nanowire (AgNW) electrode, with improved operational stability by simply applying pre-bias conditioning treatment, are demonstrated. Reverse bias conditioning performed before J–V–L measurement of the PLEDs enables the rough AgNW networks to function properly as a bottom electrode by stabilizing current characteristics, and the devices continue to show consistent operational performances. Conditions of applied bias and thicknesses of active layer are controlled for optimization and it is found that high reverse voltage is required to obtain current stabilization. Adequate thickness of polymer is also necessary to avoid breakdown induced by reverse bias. The essential effect of pre-bias conditioning on the improved performances of PLEDs is investigated, and it is found that morphological change of AgNW networks contribute to the improvement in device performance. Some of the AgNWs that appear to be pathway of leakage current are deformed, and surface roughness (RMS) of the AgNW film is decreased while the sheet resistance of the film is maintained when the reverse bias conditioning is applied. It is also revealed that pre-bias conditioning is independent from directionality of the applied bias when utilizing insulating polymer sandwiched between two electrodes.
    Advanced Functional Materials 11/2014; 24(41). DOI:10.1002/adfm.201401197 · 11.81 Impact Factor
  • Young Ju Lee · Bo Bae Choi · Kwang Sun Suh ·
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    ABSTRACT: Invasive cribriform carcinoma (ICC) of the breast is a rare type of invasive carcinoma which shows a favorable prognosis and a lower frequency of axillary nodal metastases. Few imaging findings related to ICC have been reported.
    Acta Radiologica 06/2014; 56(6). DOI:10.1177/0284185114538425 · 1.60 Impact Factor
  • Dongsun Kim · Wonjoon Ho · Kwang S. Suh ·
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    ABSTRACT: LCD manufacturing processes are often exposed to the electrostatic hazards due to going through various optic film processes. In this paper, we report the electrostatic discharge failure that occurred during the detachment process of protective film to attach consecutive one on a panel. The effects of modified surface treatment on an adhesive layer of the protective film and the entry sequence of the stage to move the following process in the peeling process of protective film were analyzed. The difference of the respective surface properties of the protective film was investigated using scanning electron microscope (SEM) and the electrostatic voltage measurements during a peeling process. The surface characterization of the film, when it is being rubbed and separated from main film, affects the amount and variation of electrostatic charge generation. Modified surface treatment of a protective film showed significant effect to reduce the failure rate and the maximum friction charge. And it was found that changing solely the entry sequence of the following stage with the modified protective film has a residual electrostatic problem. As a result, a main cause of the failure is considered that the variation of the capacitance between the panel and the stage when charges are generated during a peeling process.
    Journal of Electrostatics 06/2014; 72(3). DOI:10.1016/j.elstat.2014.03.003 · 0.86 Impact Factor
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    ABSTRACT: Quantum chemo-resistive vapour sensors have been synthesized from the assembly of magnetic nanoparticles-decorated reduced graphene oxide (Fe3O4-RGO) with poly(3,4-ethylene dioxythiophene) (PEDOT) and poly(ionic liquid) (PIL). This new hybrid sensing material demonstrated enhanced sensitivity, selectivity, signal-to-noise ratio and reduced response time compared to its elementary constituents (also sensitive), which suggests that a positive synergy of properties has been reached through the structuring of the conducting architecture by spray layer-by-layer. The Fe3O4-RGO/PIL-PEDOT sensor exhibited stable and reproducible signals at room temperature for both polar (ethanol, methanol, acetone, water) and non-polar (chloroform, styrene, dichlorobenzene, toluene) volatile organic compounds (VOC), considered as food degradation biomarkers. Since sensor’s responses are still well defined at the ppm level (and may be even at the subppm level) as attested by a SNR around 10, an application such smart packaging could be envisaged.
    Carbon 03/2014; 74:104-112. DOI:10.1016/j.carbon.2014.03.009 · 6.20 Impact Factor
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    ABSTRACT: Hybrids of silver nanoparticle-decorated reduced graphene oxide (Ag-RGO) have been prepared with the use of poly(ionic liquid) (PIL) as a versatile capping agent to develop volatile organic compound (VOC) sensors. The hybrid materials of Ag-RGO/PIL were assembled into three-dimensional-laminated nanostructures, where spherical Ag nanoparticles with diameters between 50 and 300 nm were homogeneously distributed on the graphene sheets and interspaced between them. Ag-RGO/PIL sensors were fabricated by spray layer-by-layer technique and used to detect a set of polar (methanol, ethanol, methyl acetate, acetone and water) and non-polar (chloroform, dichlorobenzene, toluene and styrene) organic vapours. Much higher sensitivity and discriminability were obtained for polar vapours although non-polar ones could also be detected. In comparison with either simple reduced graphene oxide or carbon nanotubes (CNT) functionalised by PIL, the hybrid Ag-RGO/PIL-based sensors showed superior performances in terms of sensitivity, selectivity, stability and high reliability. For example, a signal-to-noise ratio up to 168 was obtained for 1 ppm of methanol and signals drift between two experiments spaced out in the time of 3 months was less than 3 %. It is expected that by extrapolation, a limit of detection at the parts per billion level can be reached. These results are promising to design e-noses based on high stability chemoresistive sensors for emerging applications such as anticipated diagnostic of food degradation or diseases by the analysis of VOC, some of them being in this case considered as biomarkers.
    Analytical and Bioanalytical Chemistry 01/2014; 406(16):3995-4004. DOI:10.1007/s00216-013-7557-y · 3.44 Impact Factor
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    ABSTRACT: A hybrid of graphene and conducting polymer holds great potential as the active materials for high performance chemical sensor application. In this work, a thin hybrid film of reduced graphene oxide (RG-O) and poly(3,4-ethylenedioxythiophene) (PEDOT) was fabricated by means of vapor phase polymerization and explored as active material for chemical sensors. The chemical sensors based on hybrid film of RG-O and PEDOT are capable of detecting electrical signals caused by the absorption of trace levels of different analyte vapors with high sensitivity, selectivity and fast response.
    Organic Electronics 11/2013; 14(11):2789-2794. DOI:10.1016/j.orgel.2013.07.038 · 3.83 Impact Factor
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    ABSTRACT: Background The aim of this study was to evaluate the clinical characteristics of nondiabetic nephropathy in type 2 diabetes mellitus patients and to find a clinical significance of renal biopsy and immunosuppressive treatment in such a patient. Methods Renal biopsy results, clinical parameters, and renal outcomes were analyzed in 75 diabetic patients who underwent kidney biopsy at Chungnam National University Hospital from January 1994 to December 2010. Results The three most common reasons for renal biopsy were nephrotic range proteinuria (44%), proteinuria without diabetic retinopathy (20%), and unexplained decline in renal function (20.0%). Ten patients (13.3%) had only diabetic nephropathy (Group I); 11 patients (14.7%) had diabetic nephropathy with superimposed nondiabetic nephropathy (Group II); and 54 patients (72%) had only nondiabetic nephropathy (Group III). Membranous nephropathy (23.1%), IgA nephropathy (21.5%), and acute tubulointerstitial nephritis (15.4%) were the three most common nondiabetic nephropathies. Group III had shorter duration of diabetes and lesser diabetic retinopathy than Groups I and II (P=0.008). Group II had the lowest baseline estimated glomerular filtration rate (P=0.002), with the greatest proportion of renal deterioration during follow-up (median 38.0 months, P<0.0001). The patients who were treated with intensive method showed better renal outcomes (odds ratio 4.931; P=0.01). Absence of diabetic retinopathy was associated with favorable renal outcome in intensive treatment group (odds ratio 0.114; P=0.032). Conclusion Renal biopsy should be recommended for type 2 diabetic patients with atypical nephropathy because a considerable number of these patients may have nondiabetic nephropathies. And intensive treatment including corticosteroid or immunosuppressants could be recommended for type 2 diabetic patients with nondiabetic nephropathy, especially if the patients do not have diabetic retinopathy.
    09/2013; 32(3):115–120. DOI:10.1016/j.krcp.2013.07.002
  • Taeyoung Kim · Gyujin Jung · Seonmi Yoo · Kwang S Suh · Rodney S Ruoff ·
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    ABSTRACT: Electric double layer capacitors (or supercapacitors) store charges through the physisorption of electrolyte ions onto porous carbon electrodes. The control over structure and morphology of carbon electrode materials is therefore an effective strategy to render them high surface area and efficient paths for ion diffusion. Here we demonstrate the fabrication of highly porous graphene-derived carbons with hierarchical pore structures in which mesopores are integrated into macroporous scaffolds. The macropores were introduced by assembling graphene-based hollow spheres and the mesopores were derived from the chemical activation with potassium hydroxide. The unique three-dimensional pore structures in the produced graphene-derived carbons gives rise to a Brunauer-Emmett-Teller surface area value of up to 3,290 m2 g-1 and provide efficient pathway of electrolyte ions to diffuse into the interior surfaces of bulk electrode particles. These carbons exhibit both high gravimetric (174 F g-1) and volumetric (~100 F cm-3) specific capacitance in ionic liquid electrolyte in acetonitrile. The energy density and power density of the cell assembled with this carbon electrode are also high with gravimetric values of 74 Wh kg-1 and 338 kW kg-1, and volumetric values of 44 Wh L-1 and 199 kW L-1, respectively. The supercapacitor performance achieved with these graphene-derived carbons is attributed to their unique pore structure and make them potentially promising for diverse energy storage devices.
    ACS Nano 07/2013; 7(8). DOI:10.1021/nn402077v · 12.88 Impact Factor
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    ABSTRACT: Large-scale integration of vanadium dioxide (VO2) on mechanically flexible substrates is critical to the realization of flexible smart window films that can respond to environmental temperatures to modulate light transmittance. Up until now, the formation of highly crystalline and stoichiometric VO2 on flexible substrate has not been demonstrated due to the high temperature condition for VO2 growth. Here, we demonstrate a VO2-based thermochromic film with unprecedented mechanical flexibility by employing graphene as a versatile platform for VO2. The graphene effectively function as an atomically thin, flexible, yet robust support which enables the formation of stoichiometric VO2 crystals with temperature-driven phase transition characteristics. The graphene-supported VO2 was capable of being transferred to plastic substrate, forming a new type of flexible thermochromic film. The flexible VO2 films were then integrated into the mock-up house, exhibiting its efficient operation to reduce the in-house temperature under infrared irradiation. These results provide important progress for the fabrication of flexible thermochromic films for energy-saving windows.
    ACS Nano 06/2013; 7(7). DOI:10.1021/nn400358x · 12.88 Impact Factor

  • Advanced Functional Materials 03/2013; 23(10):1225-1225. DOI:10.1002/adfm.201370048 · 11.81 Impact Factor
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    ABSTRACT: The fabrication and design principles for using silver-nanowire (AgNW) networks as transparent electrodes for flexible film heaters are described. For best practice, AgNWs are synthesized with a small diameter and network structures of the AgNW films are optimized, demonstrating a favorably low surface resistivity in transparent layouts with a high figure-of-merit value. To explore their potential in transparent electrodes, a transparent film heater is constructed based on uniformly interconnected AgNW networks, which yields an effective and rapid heating of the film at low input voltages. In addition, the AgNW-based film heater is capable of accommodating a large amount of compressive or tensile strains in a completely reversible fashion, thereby yielding an excellent mechanical flexibility. The AgNW networks demonstrated here possess attractive features for both conventional and emerging applications of transparent flexible electrodes.
    Advanced Functional Materials 03/2013; 23(10). DOI:10.1002/adfm.201202013 · 11.81 Impact Factor
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    ABSTRACT: Background Rifampin is one of the most important drugs in first-line therapies for tuberculosis. The renal toxicity of rifampin has been reported sporadically and acute tubulointerstitial nephritis (ATIN) is a frequent histological finding. We describe for the first time a case of ATIN and Fanconi syndrome presenting as hypokalemic paralysis, associated with the use of rifampin. Case presentation A 42-year-old man was admitted with sudden-onset lower extremity paralysis and mild renal insufficiency. He had been treated for pulmonary tuberculosis with isoniazid, rifampin, and ethambutol for 2 months. Laboratory tests revealed proteinuria, profound hypokalemia, hyperchloremic metabolic acidosis with a normal anion gap, positive urine anion gap, hypophosphatemia with hyperphosphaturia, hypouricemia with hyperuricosuria, glycosuria with normal serum glucose level, generalized aminoaciduria, and β2-microglobulinuria. A kidney biopsy revealed findings typical of ATIN and focal granular deposits of immunoglubulin A and complement 3 in the glomeruli and tubules. Electron microscopy showed epithelial foot process effacement and electron-dense deposits in the subendothelial and mesangial spaces. Cessation of rifampin resolved the patient’s clinical presentation of Fanconi syndrome, and improved his renal function and proteinuria. Conclusion This case demonstrates that rifampin therapy can be associated with Fanconi syndrome presenting as hypokalemic paralysis, which is a manifestation of ATIN. Kidney function and the markers of proximal tubular injury should be carefully monitored in patients receiving rifampin.
    BMC Nephrology 01/2013; 14(1):13. DOI:10.1186/1471-2369-14-13 · 1.69 Impact Factor
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    Tran Thanh Tung · Ji Hye Yeon · Tae Young Kim · Kwang S. Suh ·

    Synthetic Metals 12/2012; 162(23):2182. DOI:10.1016/j.synthmet.2012.08.002 · 2.25 Impact Factor
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    ABSTRACT: Accurate diagnosis of ovarian clear cell carcinoma (CCC) is important because of its poor prognosis with chemoresistance and a high recurrent rate. The clinicopathologic characteristics and prognostic significance of the cell cycle regulator [early mitotic inhibitor-1 (Emi1)] and galactoside-binding protein (Galectin-3) were evaluated. Among 155 CCCs from 18 hospitals in Korea between 1995 and 2006, 129 pure CCCs were selected with consensus using immunohistochemical stains for hepatocyte nuclear factor-1β, Wilms' tumor protein, and estrogen receptor. The expressions of Emi1, Galectin-3, p53, and Ki-67 labeling index were analyzed with clinicopathologic parameters and the patient's survival. The mean age of the patients was 49.6 yr; the tumors were bilateral in 10.9%, and the average size was 12 cm. Adenofibromatous component was found in 7%, and endometriosis in 48.1% of the cases. Psammoma body was seen in 16.3%. Disease-free survival and overall survival rates were 78.3% and 79.1%, respectively. The International Federation of Obstetrics and Gynecology (FIGO) stage was the most important prognostic indicator. Emi1 expression (>5%) was seen in 23.3% of CCCs, and associated with high FIGO grades and poor overall survival (P<0.05). High Galectin-3 (≥80%) expression was seen in 59.7% of CCCs, and associated with FIGO stages III and IV, and high Ki-67 labeling index. High Ki-67 labeling index (≥50%) and p53 expression (≥50%) were seen in 27.1% and 18.6% of CCCs, respectively, but there was no clinicopathologic and prognostic significance. On the basis of the fact that the expression of Emi1 in CCC was correlated with a high histologic grade and worse overall survival, target therapy using inhibitors of Emi1 may be tried in the management of CCC patients with Emi1 expression.
    International journal of gynecological pathology: official journal of the International Society of Gynecological Pathologists 11/2012; 32(1). DOI:10.1097/PGP.0b013e31825554e9 · 1.67 Impact Factor
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    ABSTRACT: Sensing skins made of reduced graphene oxydes (RGO) based quantum resistive vapour sensors (vQRS) have been developed by combining two original processes, i.e., the synthesis of phase transferable graphene sheets using ionic liquid polymers (PIL) and the structuring of 3D conducting architectures by spray layer by layer (sLbL). Many advantages can be derived from this new technology such as versatility of fabrication (sprayability, no need for clean room), flexibility, potential transparency and low cost, making vQRS skins very attractive to develop the next generation of e-noses with quick response time (less than 3 s), room temperature operability, high sensitivity and adjustable selectivity. This can open the door to a wide range of applications, in particular smart packaging, making possible the monitoring of the quality/safety of food by following of VOC biomarkers emitted during its alteration. RGO based QRS are also expected to be biocompatible, exempt of cytotoxycity and the risks of migration of RGO sheets in food must be very limited thanks to their very large surface/thickness ratio and to their embedment into a polymer matrix. Comparing pristine RGO, RGO-PIL and RGO-PIL/PEDOT QRS undoubtedly establishes the superiority of the later in terms of sensitivity and selectivity for the detection of volatile organic solvents (VOC) released from food during its degradation. The reason for this can be found in the unique architecture of the transducer, optimizing functionalization in solution by the combined action of PIL and PEDOT and structuring in the solid state by the assembly step by step in 3D by sLbL.
    Journal of Materials Chemistry 10/2012; 22:21754-21766. DOI:10.1039/c2jm34806c · 7.44 Impact Factor
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    ABSTRACT: A prospective multicenter trial has been started in Korea to investigate the treatment efficacy of a levonorgestrel-releasing intrauterine system plus medroxyprogesterone acetate in young women with early-stage endometrial cancer. A number of studies have reported the effectiveness of hormonal therapy using systemic progestin in women clinically diagnosed with early endometrial adenocarcinoma at Stage IA, Grade 1, who want to maintain reproductive potential. In addition, several recent studies reported the use of a levonorgestrel-releasing intrauterine system to treat patients at a high risk of perioperative complications who cannot tolerate systemic progesterone because of its adverse effects. However, there has been no prospective multicenter trial that investigated the effectiveness of treatment with systemic progesterone in combination with intrauterine progesterone in young women with endometrial cancer. Young patients with histologically confirmed Grade 1 endometrioid adenocarcinoma that is presumably confined to the endometrium, who desired to preserve their fertility potential, undergo levonorgestrel-releasing intrauterine system insertion and are administered medroxyprogesterone acetate at a dosage of 500 mg/day concurrently. The follow-up and treatment response assessment were implemented at a 3-month interval with office endometrial aspiration biopsy with the levonorgestrel-releasing intrauterine system in place, and dilatation and curettage after removal of the levonorgestrel-releasing intrauterine system. The primary endpoint is the complete response rate. The secondary endpoint is to estimate the consistency of the results of the office endometrial aspiration biopsy with the levonorgestrel-releasing intrauterine system in the uterus and a dilatation and curettage after removal of the levonorgestrel-releasing intrauterine system.
    Japanese Journal of Clinical Oncology 10/2012; 42(12). DOI:10.1093/jjco/hys171 · 2.02 Impact Factor

Publication Stats

2k Citations
311.69 Total Impact Points


  • 1995-2015
    • Korea University
      • Department of Materials Science and Engineering
      Sŏul, Seoul, South Korea
  • 2001-2014
    • Chungnam National University
      • • Department of Pathology
      • • Department of Internal Medicine
      Daiden, Daejeon, South Korea
  • 2000-2014
    • Chungnam National University Hospital
      Sŏul, Seoul, South Korea