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1.
Talanta ; 242: 123296, 2022 May 15.
Article in English | MEDLINE | ID: mdl-35167961

ABSTRACT

Selective detection and determination of silver ions are tricky due to the poor reactivity and the interference of various metal ions and halides. Only a few cases have been reported concerning sulfur-based functionality. This work proposes silver-selective probes exhibiting peculiar colorimetric and photothermal responses without the need for sulfur-functional groups. Tetrakis(4-dialklyaminophenyl)1,4-phenylenediamine containing hexyl and methoxytriethyleneglycol substituents, PTS1 and PTS2, respectively, are selectively oxidized by silver ions to form dicationic diimmonium salts. The resulting quinone diimminium salts show strong absorption in the near-infrared (NIR) region with intense color changes. The striking color change is observed from pale brown to intense olive green with immediate responses. PTS1 shows a higher binding constant and nanomolar detection limit, whereas PTS2 shows a sub-micromolar detection limit. Job's plot studies reveal the stoichiometric ratio as 1:2 (PTS1: Ag+). Due to the strong NIR absorption of the oxidized PTS probes, the temperature rise is monitored, after adding silver ions, by a thermal camera and in-contact thermal sensors. The concentration of the actual samples can be determined based on a calibration plot with a temperature change as a function of silver ion concentration. The current results offer highly selective and ultrasensitive probes for silver ions under multiple detection mediums, including naked eye and photothermal detection.


Subject(s)
Salts , Silver , Colorimetry/methods , Ions
2.
ACS Appl Mater Interfaces ; 13(39): 46886-46893, 2021 Oct 06.
Article in English | MEDLINE | ID: mdl-34570473

ABSTRACT

Recognition of enantiomeric molecules is essential in pharmaceutical and biomedical applications. In this Article, a novel approach is introduced to monitor chiral molecules via a helical magnetic field (hB), where chiral-inactive magnetoplasmonic nanoparticles (MagPlas NPs, Ag@Fe3O4 core-shell NPs) are assembled into helical nanochain structures to be chiral-active. An in-house generator of hB-induced chiral NP assembly, that is, a plasmonic chirality enhancer (PCE), is newly fabricated to enhance the circular dichroism (CD) signals from chiral plasmonic interaction of the helical nanochain assembly with circularly polarized light, reaching a limit of detection (LOD) of 10-10 M, a 1000-fold enhancement as compared to that of conventional CD spectrometry. These enhancements were successfully observed from enantiomeric molecules, oligomers, polymers, and drugs. Computational simulation studies also proved that total chiroptical properties of helical plasmonic chains could be readily changed by modifying the chiral structure of the analytes. The proposed PCE has the potential to be used as an advanced tool for qualitative and quantitative recognition of chiral materials, enabling further application in pharmaceutical and biomedical sensing and imaging.


Subject(s)
Amino Acids/analysis , Magnetite Nanoparticles/chemistry , Peptides/analysis , Proteins/analysis , Amino Acids/chemistry , Circular Dichroism , Limit of Detection , Peptides/chemistry , Proteins/chemistry , Silver/chemistry , Stereoisomerism
3.
BMC Gastroenterol ; 20(1): 123, 2020 Apr 21.
Article in English | MEDLINE | ID: mdl-32316932

ABSTRACT

BACKGROUND: The association between Helicobacter pylori and reflux esophagitis (RE) remains controversial. This study aimed to prospectively evaluate the effect of H. pylori eradication on RE and gastroesophageal reflux (GERD) symptoms in H. pylori-positive patients who underwent endoscopic resection of gastric neoplasm. METHODS: Of the 244 patients enrolled in this study, 173 H. pylori-positive patients underwent follow-up at least once. We evaluated the prevalence of RE and GERD symptoms in these patients following H. pylori eradication. RESULTS: There were 75.7% (131/173), 78.6% (125/159), and 78.9% (105/133) subjects who were successfully eradicated after 6, 12, and 18-24 months, respectively. During the 2-year follow-up period, the eradication of H. pylori did not increase the incidence of RE (OR 0.93; 95% CI, 0.49-1.77, p = 0.828). H. pylori status was also not associated with the development of GERD symptoms (OR 1.12; 95% CI, 0.47-2.95, p = 0.721). In the univariate analysis for RE, present smoking history (OR 4.79; 95% CI 1.98-11.60, p = 0.001), present alcohol consumption history (OR 2.18; 95% CI 1.03-4.63, p = 0.041), and diabetes mellitus (OR 2.44; 95% CI 1.02-5.86, p = 0.045) were found to be associated with RE. Multivariate analysis showed that present smoking history (OR 4.54; 95% CI 1.84-11.02, p = 0.001) was a significant risk factor for RE. CONCLUSIONS: H. pylori eradication did not increase the incidence of RE or GERD symptoms in patients who underwent endoscopic resection of gastric neoplasm.


Subject(s)
Esophagitis, Peptic/drug therapy , Gastroesophageal Reflux/drug therapy , Helicobacter Infections/drug therapy , Helicobacter pylori , Stomach Neoplasms/surgery , Adult , Aged , Endoscopic Mucosal Resection , Esophagitis, Peptic/microbiology , Female , Gastroesophageal Reflux/microbiology , Gastroscopy , Helicobacter pylori/isolation & purification , Humans , Male , Middle Aged , Prospective Studies , Stomach Neoplasms/microbiology , Treatment Outcome , Young Adult
4.
J Nanosci Nanotechnol ; 20(7): 4358-4363, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-31968474

ABSTRACT

We report the relation between the catalyst patterning conditions and the intensity of the 1st order Raman active modes in Au-catalyzed GaAs nanowire bundles. We fabricated e-beam lithographically Au-patterned GaAs(111)B substrates by varying the patterning conditions (e-beam dose rate, dot-size and interdot-spacings), and grew GaAs nanowires via vapor-liquid-solid process using a solid-source molecular beam epitaxy. To understand the effects of the substrate preparation conditions and resulting morphologies on the optical characteristics of 1st order transverse optical and longitudinal optical phonon modes of GaAs, we characterized the nanowire bundles using complementary µ-Raman spectroscopy and scanning electron microscopy as a function of the e-beam dose rate (145-595 µC/cm²), inter-dot spacing (100 and 150 nm) and pattern size (100 and 150 nm). Ensembles of single crystalline GaAs nanowires covered with different Au-thickness exhibit a downshift and asymmetric broadening of the 1st order transverse optical and longitudinal optical phonon peaks relative to GaAs bulk modes. We also showed that the sensitivity of a downshift and broadening of Raman spectra are directly related to morphological and surface coverage variations in as-grown nanowires. We observed clear increases of the transverse optical and longitudinal optical intensity as well as the relatively higher peak shift and broadening of Raman spectra from the 100 nm patterning in response to the dose rate change. Strong dependence of Raman spectra of the nanowire bundles on the e-beam dose rate changes are attributed to the variations in spatial density, size, shape and random growth orientation of the wires. We have shown that the identification of the changes in GaAs longitudinal optical and Arsenic anti-site peaks is good indicators to characterize the quality of as-grown GaAs nanowires. Our finding confirms the utilization of Raman spectroscopy as a powerful tool for characterizing chemical, structural, and morphological information of as-grown nanowires within the supporting substrate.

5.
J Nanosci Nanotechnol ; 20(7): 4444-4449, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-31968493

ABSTRACT

We report the systematic investigation of the surface optical phonon modes in Au-catalyzed GaAs nanowires grown on an Au pre-patterned GaAs(111)B substrate using µ-Raman spectroscopy. We employed electron-beam dose rate as a control parameter during the substrate patterning step for adjusting the nanowire base diameter and coverage, which are independent from the nanowire growth conditions. We have experimentally studied the effect of the fill factor and average diameter on the surface optical phonon modes and explained the red-shift and broadening of the surface optical phonon frequencies by employing the dielectric continuum model. The surface optical phonon mode shift is exhibited to be sensitive to fill factor, rather than base diameter. The decrease in the average diameter from 280 nm to 180 nm results in the asymmetric broadening and red-shift of the surface optical phonon frequency (~1.83 cm-1) but the theoretical calculation from the isolated single nanowire-based dielectric continuum model cannot solely explain the behaviors of the surface optical phonon mode. In contrast, the change in the fill factor from 0.01 to 0.83 results in a shift of the surface optical phonon frequency (~6.5 cm-1) from the GaAs bulk value. The red-shift and asymmetric broadening of the surface optical phonons, in an agreement with the Maxwell-Garnett approximation, are consequences of dipolar interaction of randomly aligned neighboring nanowires and the polar nature of GaAs nanowire bundles. This work suggests the pre-patterning parameter dependent surface optical phonon characteristics of GaAs nanowire bundles which are of great importance in the nondestructive characterization of low-dimensional opto-electronic materials and devices.

6.
J Gastroenterol Hepatol ; 33(6): 1213-1219, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29193280

ABSTRACT

BACKGROUND AND AIM: Preoperative chemoradiotherapy (CRT) followed by esophagectomy is a well-known treatment modality for patients with locally advanced esophageal cancer (EC). This study developed an algorithm to predict pathological complete response (CR) in these patients using post-CRT endoscopic category with biopsy and validated the proposed algorithm. METHODS: A retrospective review of 141 consecutive patients who completed preoperative CRT and underwent surgical resection for locally advanced EC was performed. The post-CRT endoscopic findings of each patient were stratified into five categories. RESULTS: The distribution of post-CRT endoscopic categories was significantly different between the pathological CR and non-pathological CR groups (P < 0.001). About 76.8% (73/95) of patients in category 0, 1, or 2 achieved pathological CR. In contrast, 91.3% (42/46) of endoscopic categories 3 and 4 patients did not achieve pathological CR. Sensitivity of post-CRT biopsy was 11.1%. Therefore, an algorithm combining biopsy results and dichotomized post-CRT endoscopic category (category 0, 1, or 2 vs category 3 or 4) was developed. The sensitivity, specificity, and accuracy in predicting pathological CR by the proposed algorithm were 64.8%, 95.9%, and 82.8%, respectively. In the multivariate analysis, the proposed algorithm remained a significant negative factor of survival (P < 0.001). CONCLUSIONS: Algorithm using post-CRT endoscopic category with biopsy may help identify locally advanced EC patients who achieved pathological CR after preoperative CRT. Modalities to accurately detect subepithelial remnant EC may further aid in predicting pathological CR.


Subject(s)
Chemoradiotherapy, Adjuvant , Esophageal Neoplasms/therapy , Esophagectomy , Esophagoscopy , Preoperative Care , Algorithms , Biopsy , Combined Modality Therapy , Esophageal Neoplasms/pathology , Female , Forecasting , Humans , Male , Middle Aged , Multivariate Analysis , Retrospective Studies
7.
Gut Liver ; 10(5): 731-8, 2016 Sep 15.
Article in English | MEDLINE | ID: mdl-27114414

ABSTRACT

BACKGROUND/AIMS: Pregnancy-associated gastric cancer is a rare condition. This case-control study was performed to identify the clinicopathological features and prognostic factors of pregnancy-associated gastric cancer. METHODS: All consecutive patients who presented to our tertiary referral hospital with pregnancy-associated gastric cancer from 1991 to 2012 were identified. Two age-, sex-, and stagematched controls for each case were also identified from the records. Clinicopathological, gynecological, and oncological outcomes were recorded. Immunohistochemical staining was performed for estrogen receptor, progesterone receptor, epidermal growth factor receptor, human epidermal growth factor receptor, and E-cadherin. Fluorescence in situ hybridization was performed for fibroblast growth factor receptor 2. RESULTS: The median overall survival rates of the pregnancyassociated gastric cancer and control groups were 7.0 months and 15.0 months, respectively (p=0.189). Poor prognostic factors included advanced stage and tumor location in the corpus or the entire stomach but not pregnancy status or loss of E-cadherin. Pregnancy-associated gastric cancer was associated with a longer time from diagnosis to treatment (21 days vs 7 days, p=0.021). The two groups did not differ in the expression of the receptors or E-cadherin. CONCLUSIONS: The dismal prognosis of pregnancy-associated gastric cancer may related to the tumor stage and location rather than to pregnancy itself.


Subject(s)
Pregnancy Complications, Neoplastic/mortality , Stomach Neoplasms/mortality , Adult , Biomarkers, Tumor/analysis , Cadherins/analysis , Case-Control Studies , ErbB Receptors/analysis , Female , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Neoplasm Staging , Pregnancy , Pregnancy Complications, Neoplastic/pathology , Prognosis , Receptor, Fibroblast Growth Factor, Type 2/analysis , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis , Stomach/pathology , Stomach Neoplasms/chemistry , Stomach Neoplasms/pathology , Survival Rate , Time-to-Treatment , Young Adult
8.
Clin Nephrol ; 85(3): 173-8, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26249547

ABSTRACT

BK virus is ubiquitous worldwide, with infection usually occurring in early childhood. BK virus replicates prolifically under immunosuppressive conditions, causing inflammation along the genitourinary tract and progressing clinically to hemorrhagic cystitis, ureteral stenosis, and tubulointerstitial nephritis. Most BK virusassociated nephropathy occurs in renal allograft patients after kidney transplantation, although some case reports have described BK virus-associated nephropathy in the native kidney, particularly in patients with human immunodeficiency virus infection. Here we present the case of a 49-year-old male with acquired immunodeficiency syndrome (AIDS) and renal dysfunction with hydronephrosis. The renal biopsy showed tubulointerstitial nephritis with lymphoplasmacytic infiltrates and intranuclear inclusions in the tubular epithelium, which are typical findings for BK virus-associated nephropathy. In addition, immunohistochemical staining revealed that the SV40 large T antigen exhibited a nuclear localization in tubular cells. To the best of our knowledge, this is the first case report of BK virus-associated nephropathy combined with hydronephrosis that was diagnosed by biopsy in a patient with AIDS.


Subject(s)
AIDS-Associated Nephropathy/virology , BK Virus/physiology , Hydronephrosis/virology , Polyomavirus Infections/diagnosis , Tumor Virus Infections/diagnosis , AIDS Dementia Complex/virology , AIDS-Associated Nephropathy/pathology , Biopsy/methods , Fatal Outcome , Humans , Hydronephrosis/pathology , Inclusion Bodies, Viral/virology , Intranuclear Inclusion Bodies/virology , JC Virus/physiology , Leukoencephalopathy, Progressive Multifocal , Lymphocytes/pathology , Male , Middle Aged , Nephritis, Interstitial/pathology , Nephritis, Interstitial/virology , Plasma Cells/pathology , Ureteral Diseases/virology
9.
Gut Liver ; 9(1): 59-65, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25170061

ABSTRACT

BACKGROUND/AIMS: We investigated the clinical outcomes according to the method of treatment in synchronous esophageal and gastric cancer. METHODS: Synchronous esophageal squamous cell carcinoma and gastric adenocarcinoma were diagnosed in 79 patients between 1996 and 2010. We divided the patients into four groups according to treatment; Group 1 received surgical resection for both cancers or surgery for gastric cancer with chemoradiotherapy for esophageal cancer (n=27); Group 2 was treated by endoscopic resection with or without additional treatment (n=14); Group 3 received chemoradiotherapy only (n=18); and Group 4 received supportive care only (n=20). RESULTS: The median survival times in groups 1 and 2 were 86 and 60 months, respectively. The recurrence rate and mortality were 23% and 48%, respectively, in group 1 and 21% and 4%, respectively, in group 2. The median survival time was 12 months in group 3 and 9 months in group 4. Multivariate analysis showed that age (p<0.001) and treatment group (p=0.019) were significantly associated with death. Compared with group 1, treatment in the intensive care unit (p=0.003), loss of body weight (p=0.042), and decrease in hemoglobin (p=0.033) were worse in group 1. CONCLUSIONS: Endoscopic resection for synchronous esophageal and gastric cancer could be considered as a possible alternative to surgery for early-stage cancer.


Subject(s)
Adenocarcinoma/surgery , Carcinoma, Squamous Cell/surgery , Endoscopy, Gastrointestinal/methods , Esophageal Neoplasms/surgery , Neoplasms, Multiple Primary/surgery , Stomach Neoplasms/surgery , Adenocarcinoma/mortality , Adenocarcinoma/therapy , Aged , Carcinoma, Squamous Cell/mortality , Carcinoma, Squamous Cell/therapy , Combined Modality Therapy , Esophageal Neoplasms/mortality , Esophageal Neoplasms/therapy , Female , Humans , Male , Middle Aged , Neoplasms, Multiple Primary/mortality , Neoplasms, Multiple Primary/therapy , Nutritional Status , Risk Factors , Stomach Neoplasms/mortality , Stomach Neoplasms/therapy , Survival Analysis
10.
Infect Chemother ; 46(3): 165-71, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25298905

ABSTRACT

BACKGROUND: Hand hygiene compliance has improved significantly through hand hygiene promotion programs that have included poster campaign, monitoring and performance feedback, and education with special attentions to perceived subjective norms. We investigated factors associated with improved hand hygiene compliance, focusing on whether the improvement of hand hygiene compliance is associated with changed perception toward hand hygiene among medical personnel. MATERIALS AND METHODS: Hand hygiene compliance and perceptions toward hand hygiene among medical personnel were compared between the second quarter of 2009 (before the start of a hand hygiene promotion program) and the second quarter of 2012. We assessed adherence to hand hygiene among medical personnel quarterly according to the WHO recommended method for direct observation. Also, we used a modified self-report questionnaire to collect perception data. RESULTS: Hand hygiene compliance among physicians and nurses improved significantly from 19.0% in 2009 to 74.5% in 2012 (P < 0001), and from 52.3% to 91.2% (P < 0.001), respectively. These improvements were observed in all professional status or all medical specialties that were compared between two periods, regardless of the level of the risk for cross-transmission. Hand hygiene compliance among the medical personnel continued to improve, with a slight decline in 2013. Perceptions toward hand hygiene improved significantly between 2009 and 2012. Specifically, improvements were evident in intention to adhere to hand hygiene, knowledge about hand hygiene methods, knowledge about hand hygiene indications including care of a dirty and a clean body site on the same patient, perceived behavioral and subjective norms, positive attitude toward hand hygiene promotion campaign, perception of difficulty in adhering to hand hygiene, and motivation to improve adherence to hand hygiene. CONCLUSIONS: The examined hand hygiene promotion program resulted in improved hand hygiene compliance and perception toward hand hygiene among medical personnel. The improved perception increased hand hygiene compliance. Especially, the perception of being a role model for other colleagues is very important to improve hand hygiene compliance among clinicians.

11.
Gut Liver ; 8(4): 400-7, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25071905

ABSTRACT

BACKGROUND/AIMS: With technical and instrumental advances, the endoscopic removal of bezoars is now more common than conventional surgical removal. We investigated the clinical outcomes in a patient cohort with gastrointestinal bezoars removed using different treatment modalities. METHODS: Between June 1989 and March 2012, 93 patients with gastrointestinal bezoars underwent endoscopic or surgical procedures at the Asan Medical Center. These patients were divided into endoscopic (n=39) and surgical (n=54) treatment groups in accordance with the initial treatment modality. The clinical feature and outcomes of these two groups were analyzed retrospectively. RESULTS: The median follow-up period was 13 months (interquartile range [IQR], 0 to 77 months) in 93 patients with a median age of 60 years (IQR, 50 to 73 years). Among the initial symptoms, abdominal pain was the most common chief complaint (72.1%). The bezoars were commonly located in the stomach (82.1%) in the endoscopic treatment group and in the small bowel (66.7%) in the surgical treatment group. The success rates of endoscopic and surgical treatment were 89.7% and 98.1%, and the complication rates were 12.8% and 33.3%, respectively. CONCLUSIONS: Endoscopic removal of a gastrointestinal bezoar is an effective treatment modality; however, surgical removal is needed in some cases.


Subject(s)
Bezoars/surgery , Gastrointestinal Diseases/surgery , Abdominal Pain/etiology , Aged , Bezoars/diagnosis , Endoscopy, Gastrointestinal/methods , Female , Gastrointestinal Diseases/diagnosis , Humans , Lithotripsy/methods , Male , Middle Aged , Retrospective Studies , Treatment Outcome
12.
Korean J Gastroenterol ; 63(2): 114-9, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24561698

ABSTRACT

Gangliocytic paraganglioma (GP) is a rare, benign tumor which is usually found in the duodenum. We here report four recent cases of GP, with successful endoscopic resection in three cases, including a lesion on the ampulla of Vater. In all cases, each lesion had a stalk that facilitated removal using an endoscopic approach. Endoscopic mucosal resection is a feasible and safe treatment if the location, depth, and lymph node status are all favorable and is also helpful for definite diagnosis of unknown duodenal mass. To avoid morbidity resulting from open surgical resection, careful inspection for the peduncle of the GP will help determine the feasibility of endoscopic resection.


Subject(s)
Duodenal Neoplasms/surgery , Paraganglioma/surgery , Aged , Ampulla of Vater/pathology , Chromogranin A/metabolism , Colonoscopy , Duodenal Neoplasms/pathology , Endoscopy, Gastrointestinal , Female , Humans , Immunohistochemistry , Intestinal Mucosa/pathology , Intestinal Mucosa/surgery , Male , Middle Aged , Neuroendocrine Tumors/pathology , Neuroendocrine Tumors/surgery , Paraganglioma/pathology , S100 Proteins/metabolism , Synaptophysin/metabolism , Tomography, X-Ray Computed
13.
Transplantation ; 97(7): 781-7, 2014 Apr 15.
Article in English | MEDLINE | ID: mdl-24406452

ABSTRACT

BACKGROUND: The aim of this study was to investigate the feasibility and safety of endoscopic resection of gastric neoplasm in solid-organ transplant (SOT) recipients. METHODS: Between January 1994 and December 2011, the results of endoscopic resection of 17 lesions in 15 consecutive patients who had previously undergone SOT at Asan Medical Center were retrospectively evaluated. We compared clinical outcomes of this group with 1:5 matched non-SOT patients treated by endoscopic resection. RESULTS: Of the 6,491 patients who underwent SOT during the study periods, 30 patients (0.46%) with 31 lesions were diagnosed with gastric cancer, and eight patients (0.12%) with nine lesions were diagnosed with gastric adenoma. Among them, 15 patients with 17 lesions were treated by endoscopic resection, and 19 patients with 20 lesions have undergone gastrectomy. In endoscopically resected SOT group, the median duration between transplantation and endoscopic treatment was 41 months (range, 5-196 months). En bloc and complete resection were achieved in 13 (76.5%) and 15 (88.2%) lesions. Four lesions (23.5%) experienced bleeding, which was successfully managed endoscopically. When compared with post-endoscopic resection bleeding rate of non-SOT group (5.9%, [5/85]), there was no significant difference in multivariable analysis (P=0.083). CONCLUSIONS: In endoscopic resection for gastric neoplasm of SOT recipients, only manageable complications were noted in some patients, and graft dysfunctions or perforations did not occur. To avoid surgical resection with its associated perioperative mortality and morbidity, endoscopic resection for gastric neoplasm in SOT recipients is recommended as a feasible treatment with high efficacy and safety.


Subject(s)
Gastroscopy , Kidney Transplantation , Liver Transplantation , Stomach Neoplasms/surgery , Aged , Female , Humans , Male , Middle Aged , Retrospective Studies
15.
ACS Nano ; 7(5): 4050-6, 2013 May 28.
Article in English | MEDLINE | ID: mdl-23618493

ABSTRACT

For the practical application of dye-sensitized solar cells (DSSCs), it is important to replace the conventional organic solvents based electrolyte with environmentally friendly and stable ones, due to the toxicity and leakage problems. Here we report a noble water-based thixotropic polymer gel electrolyte containing xanthan gum, which satisfies both the environmentally friendliness and stability against leakage and water intrusion. For application in DSSCs, it was possible to infiltrate the prepared electrolyte into the mesoporous TiO2 electrode at the fluidic state, resulting in sufficient penetration. As a result, this electrolyte exhibited similar conversion efficiency (4.78% at 100 mW cm(-2)) and an enhanced long-term stability compared to a water-based liquid electrolyte. The effects of water on the photovoltaic properties were examined elaborately from the cyclic voltammetry curves and impedance spectra. Despite the positive shift in the conduction band potential of the TiO2 electrode, the open-circuit voltage was enhanced by addition of water in the electrolyte due to the greater positive shift in the I(-)/I3(-) redox potential. However, due to the dye desorption and decreased diffusion coefficient caused by the water content, the short-circuit photocurrent density was reduced. These results will provide great insight into the development of efficient and stable water-based electrolytes.


Subject(s)
Coloring Agents/chemistry , Electric Power Supplies , Polymers/chemistry , Solar Energy , Water/chemistry , Electrodes , Electrolytes/chemistry , Gels , Hydrophobic and Hydrophilic Interactions , Polysaccharides, Bacterial/chemistry , Titanium/chemistry
16.
Life Sci ; 92(13): 793-8, 2013 Apr 19.
Article in English | MEDLINE | ID: mdl-23454169

ABSTRACT

AIMS: The aim of this study was to evaluate the therapeutic potential of the phenethyl isothiocyanate (PEITC) in Toll-like receptor (TLR) signaling pathways. MAIN METHODS: To evaluate the cytotoxic nature of PEITC in RAW 264.7 cells, cytotoxicity was determined using the MTS cell viability assay. RAW264.7 cells were transfected with a nuclear factor-κB (NF-κB), interferon ß (IFNß) PRDIII-I, or interferon inducible protein-10 (IP-10) luciferase plasmid and then luciferase enzyme activities were determined by luciferase assay. The expression of inducible nitric oxide synthase (iNOS) and phosphorylation of interferon regulatory factor 3 (IRF3) were determined by Western blotting. The levels of IP-10 were determined with culture medium by using an IP-10 enzyme-linked immunosorbent assay (ELISA) kit. KEY FINDINGS: PEITC suppressed the activation of IRF3 and the expression of IP-10 induced by lipopolysaccharide (LPS) or polyinosinic-polycytidylic acid (poly[I:C]). SIGNIFICANCE: TLRs play an important role in the induction of innate immune responses for host defense against invading microbial pathogens. PEITC found in cruciferous vegetables has an effect on treatment of many chronic diseases. Our results suggest that beneficial effects of PEITC on chronic inflammatory diseases are mediated through modulation of Toll-interleukin-1 receptor domain-containing adapter inducing interferon-ß (TRIF)-dependent signaling pathway of TLRs.


Subject(s)
Adaptor Proteins, Vesicular Transport/immunology , Anti-Inflammatory Agents/pharmacology , Anticarcinogenic Agents/pharmacology , Isothiocyanates/pharmacology , Toll-Like Receptors/immunology , Animals , Anti-Inflammatory Agents/chemistry , Anticarcinogenic Agents/chemistry , Cell Line , Inflammation/drug therapy , Inflammation/immunology , Interferon Regulatory Factor-3/immunology , Isothiocyanates/chemistry , Lipopolysaccharides/immunology , Mice , Monocytes/drug effects , Monocytes/immunology , NF-kappa B/immunology , Poly I-C/immunology , Signal Transduction/drug effects , Vegetables/chemistry
17.
Tuberc Respir Dis (Seoul) ; 72(5): 452-6, 2012 May.
Article in English | MEDLINE | ID: mdl-23101011

ABSTRACT

Disseminated Mycobacterium avium complex (MAC) infection can occur in immunocompromised patients, and rarely in immunocompetent subjects. Due to the extensive distribution of the disease, clinical presentation of disseminated MAC may mimic malignancies, and thorough examinations are required in order to make accurate diagnosis. We report a case of disseminated Mycobacterium intracellulare disease in an immunocompetent patient, which involved the lung, lymph nodes, spleen, and multiple bones. F-18 fluorodeoxyglucose positron-emission tomography imaging showed multiple hypermetabolic lesions, which are suggestive of typical hematogenous metastasis. However, there was no evidence of malignancy in serial biopsies, and M. intracellulare was repeatedly cultured from respiratory specimens and bones. Herein, we should know that disseminated infection can occur in the immunocompetent subjects, and it can mimic malignancies.

18.
PLoS One ; 6(12): e28308, 2011.
Article in English | MEDLINE | ID: mdl-22162762

ABSTRACT

Aberrant miR-21 expression is closely associated with cell proliferation, anti-apoptosis, migration, invasion, and metastasis in various cancers. However, the regulatory mechanism of miR-21 biogenesis is largely unknown. Here, we demonstrated that the tumor suppressor PTEN negatively regulates the expression of oncogenic miR-21 at the post-transcriptional level. Moreover, our results suggest that PTEN plays such a role through the indirect interaction with the Drosha complex. To elucidate how PTEN regulates pri- to pre-miR-21 processing, we attempted to find PTEN-interacting proteins and identified an RNA-regulatory protein, RNH1. Using the sensor to monitor pri-miR-21 processing, we demonstrated that RNH1 is necessary and sufficient for pri-miR-21 processing. Moreover, our results propose that the nuclear localization of RNH1 is important for this function. Further analysis showed that RNH1 directly interacts with the Drosha complex and that PTEN blocks this interaction. Taken together, these results suggest that the PTEN-mediated miR-21 regulation is achieved by inhibiting the interaction between the Drosha complex and RNH1, revealing previously unidentified role of PTEN in the oncogenic miR-21 biogenesis.


Subject(s)
Carrier Proteins/metabolism , Gene Expression Regulation, Neoplastic , Gene Expression Regulation , MicroRNAs/metabolism , Neoplasms/metabolism , PTEN Phosphohydrolase/metabolism , Ribonuclease III/metabolism , Cell Nucleus/metabolism , Chromatography, Liquid/methods , Green Fluorescent Proteins/metabolism , HEK293 Cells , HeLa Cells , Humans , Mass Spectrometry/methods , Microscopy, Confocal/methods , RNA Processing, Post-Transcriptional
19.
J Nanosci Nanotechnol ; 11(7): 6580-3, 2011 Jul.
Article in English | MEDLINE | ID: mdl-22121760

ABSTRACT

The melting transition of nitrogen physisorbed on close-ended single-wall nanotube bundles was investigated using synchrotron X-ray diffraction measurements. The beta-nitrogen solid diffraction peak was observed above the coverage that corresponded to the monolayer and the average size of the nitrogen solid was approximately 30 A. The diffraction peak was surprisingly maintained above the triple point of the bulk nitrogen solid. The crystal structure of N2 changed from cubic N2 (beta-phase) to hexagonal N2 (beta-phase) at 35.61 K. The melting temperature of the nano-scale solid nitrogen in the experiment was between 80 K and 90 K, however, which is about 20 K higher than the melting temperature of normal bulk nitrogen. The observed extraordinary melting behavior of nitrogen might originate from a combination of two factors, i.e., the substrate field effect of the carbon nanotube surface (the interaction between the single walled carbon nanotubes and the adsorbates) and the capillary condensation. If the substrate field effect is especially prominent, the nitrogen molecules that were adsorbed mainly in the groove region would be under 1,100-Torr pressure from the nanotube bundles, compared to the corresponding melting temperature of the bulk beta-nitrogen solid under a high pressure.

20.
BMB Rep ; 44(7): 468-72, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21777518

ABSTRACT

Toll-like receptors (TLRs) are pattern recognition receptors that recognize molecular structures derived from microbes and initiate innate immunity. TLRs have two downstream signaling pathways, the MyD88- and TRIF-dependent pathways. Dysregulated activation of TLRs is closely linked to increased risk of many chronic diseases. Previously, we synthesized fumaryl pyrrolidinone, (E)-isopropyl 4-oxo-4-(2-oxopyrrolidin-1- yl)-2-butenoate (IPOP), which contains a fumaric acid isopropyl ester and pyrrolidinone, and demonstrated that it inhibits the activation of nuclear factor kappa B by inhibiting the MyD88-dependent pathway of TLRs. However, the effect of IPOP on the TRIF-dependent pathway remains unknown. Here, we report the effect of IPOP on signal transduction via the TRIF-dependent pathway of TLRs. IPOP inhibited lipopolysaccharide- or polyinosinic-polycytidylic acid-induced interferon regulatory factor 3 activation, as well as interferon- inducible genes such as interferon inducible protein-10. These results suggest that IPOP can modulate the TRIF-dependent signaling pathway of TLRs, leading to decreased inflammatory gene expression.


Subject(s)
Adaptor Proteins, Vesicular Transport/metabolism , Butyrates/pharmacology , Fumarates/pharmacology , Pyrrolidinones/pharmacology , Signal Transduction/drug effects , Toll-Like Receptors/metabolism , Animals , Butyrates/chemistry , Fumarates/chemistry , Humans , Interferon Regulatory Factor-3/metabolism , Lipopolysaccharides/pharmacology , Luciferases/metabolism , Mice , NF-kappa B/metabolism , Poly I-C/pharmacology , Pyrrolidinones/chemistry
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