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1.
Phys Chem Chem Phys ; 26(9): 7515-7521, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38357850

RESUMO

Layered post-transition-metal chalcogenides, such as InSe, In4Se3, SnSe, and SnSe2, have recently been investigated as semiconducting electronic materials and thermoelectric materials owing to their adjustable electrical transport properties either by doping or alloying. Herein, the influence of intercalation doping and substitutional doping of Cu in layered InSe alloys on electrical and thermoelectric transport properties was investigated and compared by synthesizing varied compositions of CuxInSe and In1-yCuySe. It was found that Cu was intercalated in CuxInSe samples (x = 0.01 and 0.02) and behaved as an electron donor, resulting in an increase in the electron concentration and a decrease in the activation energy. Therefore, the power factor of CuxInSe samples was increased compared to that of InSe. In contrast, the substituted Cu in the In site of In1-yCuySe samples (y = 0.01 and 0.02) acted as an acceptor, and the power factor decreased owing to a decrease in the electron concentration and activation energy. Moreover, a decrease in thermal conductivity was seen for CuxInSe and In1-yCuySe samples due to increased phonon scattering after the addition of Cu. Consequently, an enhanced thermoelectric figure of merit (zT) was only observed for intercalated CuxInSe samples due to the increased power factor and decreased thermal conductivity, while substituted In1-yCuySe samples only show degraded zT. A maximum zT value of 0.062 was observed for the CuxInSe (x = 0.02) sample at 700 K, which showed a 77% enhancement compared to that of InSe.

2.
Materials (Basel) ; 16(23)2023 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-38068088

RESUMO

In the field of construction materials, the development of fundamental technologies to reduce energy consumption and CO2 emissions, such as manufacturing process improvement and the expanded use of alternative materials, is required. Technologies for effectively reducing energy consumption and improving CO2 absorption and reduction that can meet domestic greenhouse gas reduction targets are also required. In this study, calcium-aluminate-ferrite (CAF), a ternary system of CaO·Al2O3·Fe2O3, was sintered at a low temperature (1100 °C) to examine the possibility of CO2 adsorption, and excellent CO2 absorption performance was confirmed, as the calcite content was found to be 11.01% after 3 h of the reaction between synthetic CAF (SCAF) and CO2. In addition, the physical and carbonation characteristics were investigated with respect to the SCAF substitution rate for cement (10%, 30%, 50%, 70%, and 100%). It was found that SCAF 10% developed a compressive strength similar to that of ordinary Portland cement (OPC 100%), but the compressive strength tended to decrease as the SCAF substitution rate increased. An increase in the SCAF substitution rate led to the rapid penetration of CO2, and carbonation was observed in all the specimens after 7 days. As carbonation time increased, the CO2 diffusion coefficient tended to decrease. This is because the diffusion of CO2 in the cement matrix follows the semi-infinite model of Fick's second law. SCAF can contribute to reduced energy consumption and CO2 emissions because of the low-temperature sintering and can absorb and fix CO2 when a certain amount is substituted.

3.
Materials (Basel) ; 16(15)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37570200

RESUMO

The by-products of the circulating fluidized-bed boiler combustion (CFBC) of coal exhibit self-hardening properties due to the calcium silicates generated by the reaction between SiO2 and CaO, and the ettringite generated by the reaction of gypsum and quicklime with activated alumina. These reactions exhibit tendencies similar to that of the hydration of ordinary Portland cement (OPC). In this study, the self-hydration and carbonation reaction mechanisms of CFBC by-products were analyzed. These CFBC by-products comprise a number of compounds, including Fe2O3, free CaO, and CaSO4, in large quantities. The hydration product calcium aluminate (and/or ferrite) of calcium aluminate ferrite and sulfate was confirmed through instrumental analysis. The CFBC by-products attain hardening properties because of the carbonation reaction between calcium aluminate ferrite and CO2. This can be identified as a self-hardening process because it does not require a supply of special ions from the outside. Through this study, it was confirmed that CFBC by-products generate CaCO3 through carbonation, thereby densifying the pores of the hardened body and contributing to the development of compressive strength.

4.
Mol Cells ; 42(3): 237-244, 2019 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-30759968

RESUMO

Understanding the mechanisms of cancer drug resistance is a critical challenge in cancer therapy. For many cancer drugs, various resistance mechanisms have been identified such as target alteration, alternative signaling pathways, epithelial-mesenchymal transition, and epigenetic modulation. Resistance may arise via multiple mechanisms even for a single drug, making it necessary to investigate multiple independent models for comprehensive understanding and therapeutic application. In particular, we hypothesize that different resistance processes result in distinct gene expression changes. Here, we present a web-based database, CDRgator (Cancer Drug Resistance navigator) for comparative analysis of gene expression signatures of cancer drug resistance. Resistance signatures were extracted from two different types of datasets. First, resistance signatures were extracted from transcriptomic profiles of cancer cells or patient samples and their resistance-induced counterparts for >30 cancer drugs. Second, drug resistance group signatures were also extracted from two large-scale drug sensitivity datasets representing ~1,000 cancer cell lines. All the datasets are available for download, and are conveniently accessible based on drug class and cancer type, along with analytic features such as clustering analysis, multidimensional scaling, and pathway analysis. CDRgator allows meta-analysis of independent resistance models for more comprehensive understanding of drug-resistance mechanisms that is difficult to accomplish with individual datasets alone (database URL: http://cdrgator.ewha.ac.kr).


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Software , Transcriptoma , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , Inibidores de Proteínas Quinases/farmacologia
5.
J Korean Med Sci ; 29(2): 238-42, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24550651

RESUMO

It has not yet been determined whether chronic exposure to relatively low doses of pioglitazone increases risk of bladder cancer. We aimed to assess the risk of bladder cancer associated with pioglitazone in Korean patients. This was a retrospective cohort study of diabetic patients who had ≥ 2 clinic visits between November 2005 and June 2011 at one of four tertiary referral hospitals in Korea. A prevalent case-control analysis nested within the cohort was conducted to further adjust confounders. A total of 101,953 control patients and 11,240 pioglitazone-treated patients were included, in which there were 237 and 30 cases of incidental bladder cancer (64.9 and 54.9 per 100,000 person-years; age, sex-adjusted HR 1.135, 95% confidence interval [CI] 0.769-1.677), respectively. In the prevalent case-control analysis nested within the cohort, use of pioglitazone for a duration of > 6 months, but not ever use of pioglitazone, was associated with an increased rate of bladder cancer as compared to never use of pioglitazone. In conclusion, we failed to exclude the possible association between use of pioglitazone for a duration of > 6 months and bladder cancer.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Tiazolidinedionas/uso terapêutico , Neoplasias da Bexiga Urinária/diagnóstico , Idoso , Povo Asiático , Estudos de Casos e Controles , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pioglitazona , Prevalência , República da Coreia , Estudos Retrospectivos , Fatores de Risco , Centros de Atenção Terciária , Neoplasias da Bexiga Urinária/complicações , Neoplasias da Bexiga Urinária/epidemiologia
6.
J Korean Med Sci ; 23(3): 537-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18583896

RESUMO

We report a case of complicated cataract aggravated after taking herbal medication for atopic dermatitis. An 11-yr-old boy was referred for the evaluation of decreased visual acuity in both eyes for 2 months. Past history showed that he had been diagnosed with atopic dermatitis when he was 1 yr old. He had been treated only with herbal medication for a period of 8 months prior to visiting our clinic. He had his visual acuity checked in a local ophthalmic clinic one year before, and the visual acuity was 20/20 in both eyes at that time. When attending our clinic the ophthalmologic examination showed that his best corrected visual acuity was 20/200 in both eyes. Lenses of both eyes had severe posterior subcapsular and posterior capsular opacity. Phacoemulsification, posterior chamber intraocular lens implantation, and posterior continuous curvilinear capsulectomy were performed in both eyes. After 3 months postoperatively, the best corrected visual acuity was recovered to 20/20 in both eyes without any complication. Our case suggests that there may be a risk of aggravation of cataract or development of cataract after treatment with some unidentified herbal medication in a patient with atopic dermatitis.


Assuntos
Catarata/induzido quimicamente , Dermatite Atópica/tratamento farmacológico , Medicamentos de Ervas Chinesas/efeitos adversos , Extração de Catarata , Criança , Humanos , Masculino , Acuidade Visual/efeitos dos fármacos
7.
J AAPOS ; 10(6): 581-2, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17189156

RESUMO

Acute extraocular muscle restriction in children is a rare condition; orbital myositis is the most common cause. Most neuropathic or myopathic causes of strabismus present as an incomitant deviation. We report a case of orbital cellulitis preceding acute comitant esotropia in a patient showing no evidence of myositis or neurologic pathology.


Assuntos
Celulite (Flegmão)/complicações , Esotropia/etiologia , Doenças Orbitárias/complicações , Celulite (Flegmão)/diagnóstico , Criança , Diagnóstico Diferencial , Esotropia/diagnóstico , Esotropia/cirurgia , Movimentos Oculares , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Músculos Oculomotores/patologia , Músculos Oculomotores/fisiopatologia , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos/métodos , Doenças Orbitárias/diagnóstico , Tomografia Computadorizada por Raios X
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