Showing papers by "Won Ho Kim published in 2006"
TL;DR: Nine factors have been found to be associated with IPPB and polypectomy should be undertaken with caution under these conditions, and eight of them were significant risk factors for IPPB.
241 citations
TL;DR: This study demonstrates for the first time that NFATc4 and ATF3 function as negative regulators of adiponectin gene expression, which may play critical roles in downregulating adip onectin expression in obesity and type 2 diabetes.
Abstract: Expression of adiponectin decreases with obesity and insulin resistance. At present, the mechanisms responsible for negatively regulating adiponectin expression in adipocytes are poorly understood. In this investigation, we analyzed the effects of 5' serial deletion constructs on the murine adiponectin promoter. Here, we identified the repressor region located between -472 and -313 bp of the promoter. Removal of the putative nuclear factor of activated T-cells (NFATs) binding site increased the promoter activity, and overexpression of NFATc4 reduced the promoter activity. Treatment with the calcium ionophore A23187, an activator of NFAT, reduced mRNA as well as promoter activity. The binding of NFATc4 to the promoter was associated with increased recruitment of histone deacetylase 1 and reduced acetylation of histone H3 at the promoter site. In addition, binding of activating transcription factor 3 (ATF3) to the putative activator protein-1 site located adjacent to the NFAT binding site also repressed the promoter activity. Treatment with thapsigargin, an inducer of ATF3, reduced both mRNA and promoter activity. Importantly, the binding activities of NFATc4 and ATF3, increased significantly in white adipose tissues of ob/ob and db/db mice compared with controls. Taken together, this study demonstrates for the first time that NFATc4 and ATF3 function as negative regulators of adiponectin gene expression, which may play critical roles in downregulating adiponectin expression in obesity and type 2 diabetes.
110 citations
TL;DR: The authors show distinct mitochondrial retrograde signalling, where Irs1 is downregulated through ATF3 in a Ca2+-, JNK- and p38 MAPK-dependent manner, and IRS1 is inactivated, which causes aberrant insulin signalling and abnormal utilisation of glucose, as observed in many insulin resistance states.
Abstract: Mitochondrial dysfunction is considered a critical component in the development of diabetes. The aim of this study was to elucidate the molecular mechanisms involved in the development of insulin resistance and diabetes through investigation of mitochondrial retrograde signalling. Mitochondrial function of C2C12 myotube cells was impaired by genetic (ethidium bromide) and metabolic (oligomycin) stress, and changes in target molecules related to insulin signalling were analysed. Concomitant with reductions in mitochondrial membrane potential (ΔΨm) and ATP synthesis, production of IRS1 and solute carrier family 2 (facilitated glucose transporter), member 4 (SLC2A4, formerly known as GLUT4) were reduced. Moreover, serine phosphorylation of IRS1 increased, resulting in decreased tyrosine phosphorylation. This indicates that mitochondrial dysfunction decreases insulin-stimulated SLC2A4 translocation and glucose uptake. Mitochondrial stress activated c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) signalling in a Ca2+-dependent manner, and removal of free Ca2+ by BAPTA-AM, as well as inhibition of JNK and p38 MAPK, abrogated mitochondrial stress-induced reductions in IRS1 and SLC2A4 production. Mitochondrial dysfunction after oligomycin treatment significantly increased levels of activating transcription factor 3 (ATF3), which represses Irs1 promoter activity. Removal of the 5′ flanking region of Irs1 demonstrated that the promoter region within 191 bases from the transcription site may be involved in the transcriptional repression of Irs1 by mitochondrial stress. We show distinct mitochondrial retrograde signalling, where Irs1 is downregulated through ATF3 in a Ca2+-, JNK- and p38 MAPK-dependent manner, and IRS1 is inactivated. Therefore, mitochondrial dysfunction causes aberrant insulin signalling and abnormal utilisation of glucose, as observed in many insulin resistance states.
74 citations
TL;DR: It is suggested that chronic ethanol consumption decreases hepatic NK activity, thereby accelerating MCMV-induced hepatitis and liver injury.
Abstract: Background: Chronic alcohol drinking accelerates the progression of liver disease in patients with hepatitis viral infection; however, the underlying mechanisms are not fully understood. Methods: Here, we examined the effects of chronic ethanol feeding on hepatic natural killer (NK) cells and liver injury in 2 murine models of liver injury: injection of synthetic double-stranded RNA polyinosinic-polycytidylic acid (poly I:C), which mimics viral infection, and infection with murine cytomegalovirus (MCMV). Mice were fed the Lieber-DeCarli liquid diet containing 5% (vol/vol) ethanol for 8 weeks, resulting in a significant decrease in the percentage and total number of NK cells in the liver. Results: In control, pair-fed mice, poly I:C injection induced NK cell accumulation in the liver and activated hepatic NK cell cytotoxicity, whereas such induction and activation were diminished in ethanol-fed mice. Treatment with poly I:C also induced expression of NKG2D, granzyme B, perforin, Fas L, TRAIL, and IFN-g on liver lymphocytes, which were delayed or reduced in ethanol-treated mice compared with pair-fed mice. In contrast, chronic ethanol feeding did not affect poly I:C–induced mild liver injury. Furthermore, MCMV infection activated hepatic NK cells and induced hepatic inflammation and injury. Chronic ethanol consumption inhibited hepatic NK cell activation during MCMV infection, but enhanced MCMV-induced liver injury, viral titer, and inflammation in the liver. Conclusions: Taken together, these findings suggest that chronic ethanol consumption decreases hepatic NK activity, thereby accelerating MCMV-induced hepatitis and liver injury.
61 citations
TL;DR: This was the first multicenter colonoscopy survey that examined the characteristics of colorectal neoplasm in Asia and the results will have important implications on the planning for future coloreCTal cancer screening in this region.
58 citations
TL;DR: Patients with anti-Saccharomyces cerevisiae antibody (+) intestinal Behçet’s disease were more likely to receive surgical treatment and the cumulative relapse rates were not different between the two groups.
Abstract: This study was designed to assess anti-Saccharomyces cerevisiae antibody positive rate in Behcet’s disease and intestinal Behcet’s disease and to evaluate whether anti-Saccharomyces cerevisiae antibody expression is associated with clinical findings at diagnosis and clinical course of intestinal Behcet’s disease. One hundred six patients with intestinal Behcet’s disease, 30 patients with Behcet’s disease, and 45 healthy control subjects were included. Anti-Saccharomyces cerevisiae antibody was detected by indirect immunofluorescence assay. According to anti-Saccharomyces cerevisiae antibody expression, the various parameters at diagnosis, cumulative relapse rates, and cumulative probabilities of operation were analyzed. Anti-Saccharomyces cerevisiae antibody positive rate was 44.3 percent in intestinal Behcet’s disease, 3.3 percent in Behcet’s disease, and 8.8 percent in healthy control subjects. In patients with intestinal Behcet’s disease, age, gender, distribution of Behcet’s disease subtype, symptoms, laboratory tests, and colonoscopic findings at diagnosis were not different according to anti-Saccharomyces cerevisiae antibody expression. Cumulative probability of a first operation was significantly higher in anti-Saccharomyces cerevisiae antibody (+) intestinal Behcet’s disease than in anti-Saccharomyces cerevisiae antibody (−) intestinal Behcet’s disease: 44.8 and 17.2 percent at one year, and 53 and 24.3 percent at two years after diagnosis, respectively (P = 0.006). The number of patients who underwent two or more operations was higher in anti-Saccharomyces cerevisiae antibody (+) intestinal Behcet’s disease than in anti-Saccharomyces cerevisiae antibody (−) intestinal Behcet’s disease (21.3 vs. 8.5 percent). The cumulative relapse rates were not different between the two groups. Anti-Saccharomyces cerevisiae antibody positive rate was 44.3 percent in intestinal Behcet’s disease. Clinical findings at diagnosis and cumulative relapse rates of intestinal Behcet’s disease were not found to be associated with anti-Saccharomyces cerevisiae antibody expression. However, patients with anti-Saccharomyces cerevisiae antibody (+) intestinal Behcet’s disease were more likely to receive surgical treatment.
48 citations
TL;DR: GF-AS may alleviate alcohol-induced hepatotoxicity through increasing ethanol and lipid metabolism, as well as antioxidant defense systems in livers injured by acute- and chronic-alcohol treatment.
Abstract: The protective effect of a 30 kDa glycoprotein (GF-AS) isolated from the stem bark of Acanthopanax senticosus against acute and chronic alcohol-induced hepatotoxicity were studied. N-terminal amino acid sequence of GF-AS showed NH2-Val-Ala-Tyr-Pro-Trp-Ala-Gly-Phe-Ala-Leu-Ser-Leu-Glx-Pro-Pro-Ala-Gly-Tyr-. GF-AS significantly increases the activities of alcohol-metabolizing enzymes, including alcohol dehydrogenase, microsomal ethanol metabolizing system, and acetaldehyde dehydrogenase in rats acutely treated with alcohol, resulting in decreased plasma alcohol levels. GF-AS also increases the activities of antioxidant enzymes and glutathione level. Markers of liver injury induced by alcohol: elevated serum levels of aspartate aminotransferase, alanine aminotransferase, triglyceride and cholesterol, are reduced by GF-AS in both acutely and chronically treated rats. The activities of lipogenic enzymes including malic enzyme, glucose-6-phosphate dehydrogenase, and 6-phosphoglucuronic acid dehydrogenase in chronic alcohol-treated rats are significantly decreased by GF-AS. Furthemore, GF-AS improves histological change in fatty liver and hepatic lesions induced by alcohol. Collectively, GF-AS may alleviate alcohol-induced hepatotoxicity through increasing ethanol and lipid metabolism, as well as antioxidant defense systems in livers injured by acute- and chronic-alcohol treatment.
42 citations
TL;DR: Although the difference in insertion time was not substantial, a history of abdominal or pelvic surgery is associated with difficulty in colonoscopy, and a surgical history lost statistical power as a predictor for prolonged insertion time in multivariate analysis.
Abstract: Goals: This large prospective study attempted to analyze the effect of various prior surgery on colonoscopy performance. Background: It is generally presumed that colonoscopy in patients with a history of abdominal or pelvic surgery is difficult. This difficulty is apparently due to adhesions and anatomic alterations after surgery but the incidence, site, and severity of adhesions are different according to the types of surgery. Study: We analyzed completion rate and insertion time in 4089 consecutive colonoscopies in patients with intact colon. Results: The adjusted completion rate for colonoscopy was 96.7%. The mean insertion time was 6.2 ± 4.0 minutes. Not only old age [odds ratio (OR) 1.46; 95% confidence interval (CI) [1.04, 2.04]] and inadequate bowel cleansing (OR 5.82; 95% CI [4.19, 8.09]) but also a surgical history (OR 1.71; 95% CI [1.18, 2.48]) were independent factors associated with procedural incompleteness. Of surgical history, gastrectomy and hysterectomy were significantly associated with procedural incompleteness (P 10min), but a surgical history lost statistical power as a predictor for prolonged insertion time in multivariate analysis. Conclusions: Although the difference in insertion time was not substantial, a history of abdominal or pelvic surgery is associated with difficulty in colonoscopy.
41 citations
Journal Article•
TL;DR: Because preoperative self-expandable metallic stent insertion for obstructive colorectal cancer had better postoperative results and shorter hospital days than emergent diverting colostomy, this procedure is a good "bridge to surgery".
Abstract: BACKGROUND/AIMS As the treatment of acute malignant obstruction of the left colon, self-expandable metallic stent insertion has been clinically used with good results. The aim of this study is to analyze the outcome of planned operation after stent insertion for obstructive colorectal cancer. METHODOLOGY From 2000 to 2003, among 37 patients treated for obstructive colorectal cancer, we compared hospital days and complications between Group A (n=18) and Group B (n=19). Group A included the patients who underwent planned operation after stent insertion and Group B included the patients who underwent planned operation after emergency temporary colostomy formation. RESULTS In Group A, complications after stent insertion were perforation with abscess formation (n=1) and stent migration (n=2). Complications after definitive operation were not observed. In Group B, complications after temporary colostomy involed stoma site wound infection (n=2). Complications after definitive surgery were as follows: anastomotic leakage (n=1), pneumonia with acute renal failure (n= 1), wound infection (n=2). In group A and group B, hospital day after decompressive procedure was 5+/-4.0 days (range, 1-16 days) vs. 14+/-4.7 days (range, 7-27 days) (P=0.000). Hospital day after definitive operation was 11+/-4.0 days (range 8-22 days) vs. 16+/-9.2 days (range 10-41 days) (P=0.002). CONCLUSIONS Because preoperative self-expandable metallic stent insertion for obstructive colorectal cancer had better postoperative results and shorter hospital days than emergent diverting colostomy, this procedure is a good "bridge to surgery".
30 citations
TL;DR: In this article, a thin interlayer between indium tin oxide (ITO) and a hole transporting layer (HTL) in a multi-layered, organic, light-emitting diode (OLEDs) was placed as well as a well-stacked CuPc layer.
Abstract: Vacuum deposited copper phthalocyanine (CuPc) was placed as a thin interlayer between indium tin oxide (ITO) electrode and a hole transporting layer (HTL) in a multi-layered, organic, light-emitting diode (OLEDs). The well-stacked CuPc layer increased the stability and efficiency of the devices. Thermal annealing after CuPc deposition and magnetic field treatment during CuPc deposition were performed to obtain a stacked-CuPc layer; the former increased the stacking density of the CuPc molecules and the alignment of the CuPc film. Thermal annealing at about 100°C increased the current flow through the CuPc layer by over 25%. Surface roughness decreased from 4.12 to 3.65 nm and spikes were lowered at the film surface as well. However, magnetic field treatment during deposition was less effective than thermal treatment. Eventually, a higher luminescence at a given voltage was obtained when a thermally-annealed CuPc layer was placed in the present, multi-layered, ITO/CuPc/NPD/Alq3/LiF/Al devices. Thermal annealing at about 100°C for 3 h produced the most efficient, multi-layered EL devices in the present study.
27 citations
TL;DR: Thyroid metastasis with hypothyroidism developing acutely from metastatic colon adenocarcinoma was diagnosed and the patient was started on palliative chemotherapy with thyroid hormone replacement and gradually became euthyroid.
Abstract: An 85-year-old man who had undergone a right hemicolectomy for colon cancer presented with severe hypothyroidism and hoarseness 21 months after the operation. The serum thyrotropin (TSH) was markedly elevated to 118.14 μIU/mL and serum free thyroxine (fT4) level was markedly suppressed to 0.34 ng/dL. Symptoms of hoarseness and neck swelling were already evident 4 months prior at which time tests for normal thyroid function were performed. The patient was referred due to aggravated pain on his diffusely enlarged hard goiter. An enlarged thyroid with some calcification was noticed in the neck ultrasonography with multiple cervical lymphadenopathies. Core biopsy of the thyroid gland showed invasion of poorly differentiated adenocarcinoma cells. Immunohistochemical studies showed positive staining only for carcinoembryonic antigen (CEA). There were multiple lung parenchymal nodules and adrenal masses at the time of evaluation. The patient was started on palliative chemotherapy with thyroid hormone replacement and gradually became euthyroid. From these findings and the clinical observations, thyroid metastasis with hypothyroidism developing acutely from metastatic colon adenocarcinoma was diagnosed.
15 Oct 2006-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the neutron-induced prompt gamma-ray analysis method was evaluated for the detection of explosives by measuring the H, C(C/H), and N(N/H) concentrations of samples at a research nuclear reactor.
Abstract: Neutron-induced prompt gamma-ray analysis method was evaluated for the detection of explosives by measuring the H, C(C/H), and N(N/H) concentrations of samples at a research nuclear reactor. The hydrogen concentration was measured from the calibration curves obtained from various samples which contained hydrogen, and the detection limit for the determination of hydrogen in the samples was estimated. Standard reference materials (NIST SRMs) were used as analytical controls. The γ- spectra obtained here will be directly used for further studies as a training set for a pattern recognition to develop suitable discriminant classes with which explosives can be distinguished from innocuous materials.
TL;DR: Age, gender, and referral for Colonoscopy from primary care physician constituted important independent predictors of advanced CRN in patients undergoing colonoscopy in patients facing advanced colorectal cancer.
Abstract: BACKGROUND AND STUDY AIMS The factors that more accurately predict the detection of colorectal cancers and adenomas at colonoscopy are different. We conducted a prospective multicenter study to evaluate which indications were most closely associated with advanced colorectal neoplasm (CRN), including colorectal cancer, in a group of patients undergoing colonoscopy. PATIENTS AND METHODS The 17 468 patients were enrolled in this study between July 2003 and March 2004, from 11 tertiary medical centers in Korea. They were recruited according to 11 itemized colonoscopic indications. The term "advanced adenoma" refers here to tubular adenomas of diameter of 11 mm or more, or to tubulovillous, villous, or severely dysplastic adenomas, irrespective of their size. Cancer was defined as the invasion of malignant cells beyond the muscularis mucosa. Advanced CRN was defined as advanced adenoma or invasive cancer. RESULTS Advanced CRN was found in 1227/17 307 patients (1176 advanced adenomas plus 51 carcinomas, 7.1 %). According to univariate and multivariate analysis, the factors associated with advanced CRN included age >60 years (odds ratio (OR) 2.1, 95 % confidence interval (CI) 1.8 - 2.4, P < 0.0001), male gender (OR 2.1, 95 %CI 1.7 - 2.7, P < 0.0001), referral for colonoscopy from primary care physician (OR 3.1, 95 %CI 2.5 - 3.7, P < 0.0001), and several other indications (OR 1.8, 95 %CI 1.5 - 2.3, P < 0.001). The yield of colonoscopy for advanced CRN was lower (2.2 %) than expected in patients with iron-deficiency anemia (OR 0.5, 95 %CI 0.2 - 0.9, P = 0.03). CONCLUSIONS Age, gender, and referral for colonoscopy from primary care physician constituted important independent predictors of advanced CRN in patients undergoing colonoscopy.
TL;DR: A 41-year-old woman was admitted to hospital with intermit− tent abdominal pain which she experi− enced during defecation and was charged from hospital 8 days after the op− eration of a benign mature cystic teratoma which had ruptured, leading to the formation of a colonic fistula.
Abstract: A 41−year−old woman (gravida 2, para 2) was admitted to hospital with intermit− tent abdominal pain which she experi− enced during defecation. Her medical his− tory was uneventful. Colonoscopy re− vealed a hyperemic, polypoid mass with a stalk, 15 cm from the anal verge (Fig− ure 1); computed tomography revealed a right ovarian mass that was continuous with the intraluminal lesion in the sig− moid colon. At surgery, a right ovarian mass was identified which was adhering to the sigmoid colon and to the pelvic peritoneum on the right side. Right sal− pingo−oophorectomy and an anterior re− section with a colorectal anastomosis were performed. The resected specimen included a pedunculated polyp of the sig− moid colon, which was continuous with an ovarian mass (Figure 2). The length of the polyp stalk was 1.8 cm. The pathologi− cal diagnosis was a benign mature cystic teratoma which had ruptured, leading to the formation of a colonic fistula, and which had subsequently protruded into the colonic lumen. The patient had no postoperative complications and was dis− charged from hospital 8 days after the op− eration.
Journal Article•
TL;DR: Stent placement is a useful alternative to emergency surgery for the management of malignant colorectal obstruction and has the tendency to be shorter for group A than for group B.
Abstract: Background/Aims: The aim of this study was to compare the outcome of colorectal stenting with that of performing emergency operation for the patients with malignant left-sided colon obstruction. Methods: The patients with obstructing left-sided colorectal cancer were treated with 'bridge to surgery stenting' and this was followed by operation (group A, n=20), emergency operation (group B, n=21), palliative stenting (group C, n=16), and emergency palliative operation (group D, n=15). Results: The primary anastomosis rate was significantly higher for group A than for group B (65.0 vs. 33.3%, respectively, p＜0.05). None of the patients in group A required intensive care and 3 patients in group B required intensive care. Post-operative complications occurred in 2 and 3 patients in group A and B, respectively. The mean hospital stay showed the tendency to be shorter for group A than for group B (24 vs. 31 days, respectively, p＞0.05). In regard to palliative treatment, the stoma creation rate was 86.7% for group D, and 2 patients in group D needed intensive care. The mean hospital stay was significantly shorter for group C than for group D (9.3 vs. 20.7 days, respectively, p＜0.05). Conclusions: Stent placement is a useful alternative to emergency surgery for the management of malignant colorectal obstruction.
Journal Article•
TL;DR: In this paper, a linear relationship between track diameter and particle size is used as a useful first stage analytical tool as an efficient and convenient inspection guide, and the significance of the simple linear model was also judged using the usual statistical tests.
TL;DR: In this paper, the boron isotopic ratio can be measured by observing the number of alpha tracks for different concentrated standard solutions with various isotopic compositions using a solid state track detector.
Abstract: The determination of the boron isotopic ratio in solutions was achieved by means of a solid state track detector by using an alpha track The neutron flux was optimized by using a Cd-foil to find the optimum conditions for counting the number of alpha tracks on the selected solid detector caused by the (n, ) nuclear reaction of boron The home-made multi-dot detector plate was utilized in this study to increase the reproducibility of the measurement by uniformly drying the boron solution within the marked circle area on the detector plate The experimental results of this study verified that the isotopic ratio can be measured by observing the number of alpha tracks for different concentrated standard solutions with various isotopic compositions This technique was applied to the determination of enrichment factor in a biological sample for a boron neutron capture therapy
01 Jan 2006
TL;DR: In this paper, two types of OLS are prepared, i.e. dodecylamine (primary amine) modified montmorillonite (DA-MMT) and N, N-dimethyldodecylamine (tertiary amino) modified MMT (DDA -MMT), and X-ray diffraction (XRD) and transmission electron microscopy (TEM) are employed to characterize the layer distance and the morphology of the nanocomposites.
Abstract: SBR (styrene-butadiene rubber; 25 wt% of solid contents) nanocomposites reinforced with OLS(organically modified layered silicates) were manufactured via the latex method. Two types of OLS are prepared, i.e. dodecylamine (primary amine) modified montmorillonite (DA-MMT) and N, N-dimethyldodecylamine (tertiary amino) modified MMT (DDA-MMT). X-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to characterize the layer distance of OLS and the morphology of the nanocomposites. SBR nanocomposites reinforced with ternary phase filler (carbon black/silica/OLS) systems also manufactured. Dynamic mechanical thermal analysis (DMTA) was performed on these composites to determine the loss factor (tan ) over a range of temperature(). The results showed that there was significant changes on the values or tan with the addition of small amount of the OLS. By increasing the contents of OLS, the values of tan at increased but those of tan at decreased with increasing OLS contents.
01 Jan 2006
TL;DR: In this paper, modified DA-MMT filled NR/DAMMT nanocomposites were manufactured by a latex method and a compounding method and the degree of intercalation and dispersion was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).
Abstract: In this study, modified DA-MMT filled NR/DA-MMT nanocomposites were manufactured by a latex method and a compounding method. Cure characteristics and mechanical properties of the Cloisite 15A, carbon black, Na-MMT filled NR compounds and the DA-MMT filled NR compound by a latex method were also evaluated. The filler content of all compounds was 10phr except the carbon black filled compound. Degree of intercalation and dispersion was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). According to the XRD diffraction pattern and TEM analysis, extensive intercalation and homogeneous dispersion of the clay were obtained after the two-roll milling. Although the layer distance was increased, some parts of DA-MMT showed the layer distance of Na-MMT after vulcanization. DA-MMT filled NR compounds showed the highest ODR torques, tensile strength, modulus, and tear energy. The NR/DA-MMT nanocomposite (by a latex method) compared with a NR/DA-MMT nanocomposite (by a compounding method) was found that the improvement of the mechanical properties was mainly due to the degree of dispersion of the clay.
TL;DR: Kim et al. as discussed by the authors assessed the predictive value of initial patient and adenoma characteristics during surveillance colonoscopy and found that male sex, older age, current or former smoking, and low physical activity are important indicators of colorectal adnoma recurrence.
TL;DR: In this article, the effects of parameters such as contents of the triblock copolymer, cure temperature, and contents of catalyst on the morphology of the blend systems were studied, and the effect of these parameters on fracture toughness and impact energy absorption was found.
Abstract: The shortcoming of epoxy resin is the brittleness of this material though it shows excellent chemical, mechanical and electric properties. To improve fracture toughness of epoxy resin, rubbery materials that show high values in toughness but low values in glass transition temperature and mechanical properties, and thermoplastics that show high values in thermal and mechanical properties but relatively small increase in toughness were blended with epoxy. ATPEI-CTBN-ATPEI triblock copolymer, which consists of rubbery and thermoplastics blocks, was synthesized, and the triblock copolymer was blended with epoxy resin. The effects of parameters such as contents of the triblock copolymer, cure temperature, and contents of catalyst on the morphology of the blend systems were studied. From 30 wt% of the contents of the triblock copolymer, fracture toughness and impact energy absorption of the blend systems were increased significantly. This was due to the generation of nodular morphology in the system.
TL;DR: In this paper, a common glass vial was used for the convenient NIR quantification of DEHPA in the presence of the interference from a solvent absorption by using NIR spectroscopic technique equipped with a user-friendly commercial software for a multivariate calibration.
Abstract: were the conventional method reported for the determination of DEHPA, while the spectrophotometric analysis of DEHPA in an organic solvent has not been taken into account. Total organic carbon method as a general quantitative determination tool for most organic materials cannot be used in organic media such as hexane. Despite the disadvantages of requiring the time-consuming calibration and validation with plenty of samples as well as a proper understanding of chemometric techniques in near infrared (NIR) technique for industrial applications, practically useful instrumentations such as attractive portable NIR system have been suggested recently. 7 In this study, common glass vial was used for the convenient NIR quantification of DEHPA in the presence of the interference from a solvent absorption by using NIR spectroscopic technique equipped with a user-friendly commercial software for a multivariate calibration. This will be technically useful for various field applications. Simple wavelength selection and effect of pathlength were also investigated.