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1.
Environ Res ; 227: 115707, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-36931382

RESUMO

Superior de-NOx activity and N2 selectivity of the Pd/ZSM-5 catalyst was observed at low temperature (<200 °C) for the selective catalytic reduction of NOx by H2 (H2-SCR). Various Pd/ZSM-5 catalysts were prepared by calcinating at different temperatures (e.g., 500 °C, 650 °C, 750 °C, and 850 °C) and treated at reductive conditions before the H2-SCR reaction was performed. Among the prepared catalysts, the one prepared at the calcination temperature at 750 °C resulted in 96.7% NOx conversion and 96.8% N2 selectivity at 150 °C. Based on the H2-O2 reaction, the higher activity of the Pd/ZSM-5 catalyst calcined at 750 °C was attributed to its superior H2 activation ability for the H2-SCR reaction. The combined X-ray diffraction (XRD), temperature-programmed hydride decomposition (TPHD), and transmission electron microscopy (TEM) results revealed that highly dispersed Pd particles were generated on the catalyst calcined at 750 °C, while large Pd agglomerates were formed on the one calcined at 500 °C. It can be concluded that the catalytic activity of Pd/ZSM-5 improves by optimizing the calcination temperature, resulting in high Pd dispersion. Moreover, the Pd catalyst calcined at 750 °C showed high resistance to CO, maintaining >94% NOx conversion at 175 °C under 1000 ppm CO in the feed gas. Therefore, the catalyst calcined at 750 °C can be potentially used for industrial applications because of its simple preparation method and high resistance to CO.


Assuntos
Amônia , Temperatura Baixa , Temperatura , Catálise , Oxirredução
2.
Langmuir ; 36(26): 7210-7216, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32558577

RESUMO

Separation of particles is essential to ensure the reliability and reproducibility of experiments for nanometer-scale materials. There are several methods, such as ultracentrifugation, precipitation, filtration, etc., for separation. However, the separation of nanoparticles in a continuous operation has not been examined widely. Here, we report the separation of nanometer-scale particles on a microfluidic system and related separation phenomena of nanoparticles from microparticles. We also describe not-yet-confirmed reversed behaviors of nanoparticle separation in the process of continuous operation. The present system along with elucidated operational conditions could be applied to treat relatively large quantities of nanometer-scale particles.

3.
J Am Soc Nephrol ; 24(10): 1529-36, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23833258

RESUMO

Regulatory T cells (Tregs) can suppress immunologic damage in renal ischemia-reperfusion injury (IRI), but the isolation and ex vivo expansion of these cells for clinical application remains challenging. Here, we investigated whether the IL-2/anti-IL-2 complex (IL-2C), a mediator of Treg expansion, can attenuate renal IRI in mice. IL-2C administered before bilateral renal IRI induced Treg expansion in both spleen and kidney, improved renal function, and attenuated histologic renal injury and apoptosis after IRI. Furthermore, IL-2C administration reduced the expression of inflammatory cytokines and attenuated the infiltration of neutrophils and macrophages in renal tissue. Depletion of Tregs with anti-CD25 antibodies abrogated the beneficial effects of IL-2C. However, IL-2C-mediated renal protection was not dependent on either IL-10 or TGF-ß. Notably, IL-2C administered after IRI also enhanced Treg expansion in spleen and kidney, increased tubular cell proliferation, improved renal function, and reduced renal fibrosis. In conclusion, these results indicate that IL-2C-induced Treg expansion attenuates acute renal damage and improves renal recovery in vivo, suggesting that IL-2C may be a therapeutic strategy for renal IRI.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Complexo Antígeno-Anticorpo/fisiologia , Diferenciação Celular/imunologia , Interleucina-2/fisiologia , Insuficiência Renal/prevenção & controle , Traumatismo por Reperfusão/prevenção & controle , Linfócitos T Reguladores/imunologia , Animais , Avaliação Pré-Clínica de Medicamentos , Fibrose , Interleucina-2/imunologia , Rim/imunologia , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Insuficiência Renal/imunologia , Insuficiência Renal/patologia , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/patologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/patologia
4.
BMJ Open ; 13(7): e068282, 2023 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-37500267

RESUMO

OBJECTIVES: This study identifies depressive symptoms and the factors that could explain its presence in breastfeeding people. DESIGN: This study is a cross-sectional study from national survey data. SETTING AND PARTICIPANTS: Data were derived from the 2019 Korean Community Health Survey. The study subjects were breastfeeding people under the age of 50. PRIMARY OUTCOME MEASURES: Depressive symptoms in breastfeeding people were classified according to the Patient Health Questionnaire-9 (PHQ-9) score. Physical and health behaviours were considered as factors related to depressive symptoms. A multilevel logistic regression analysis was used. RESULTS: Among 497 participants, 19.4% (n=97) of breastfeeding people were depressed. We found that depressive symptoms were associated with age (31-35, OR: 0.79, 95% CI: 0.67 to 0.94; 35-49, OR: 0.42, 95% CI: 0.32 to 0.56), rural setting (OR: 0.62, 95% CI: 0.51 to 0.76), economic activity (OR: 0.75, 95% CI: 0.61 to 0.91) and physical health (diabetus mellitus or hypertension, OR: 5.17, 95% CI: 3.78 to 7.06). CONCLUSIONS: This study implies that socioeconomic factors, physical health and health behaviours may influence depressive symptoms in breastfeeding people. These findings should be used as descriptive data to support the development of education programmes to help breastfeeding people.


Assuntos
Aleitamento Materno , Depressão , Feminino , Humanos , Depressão/epidemiologia , Estudos Transversais , Inquéritos e Questionários , Fatores Socioeconômicos , República da Coreia/epidemiologia
5.
Stem Cells Int ; 2023: 5475212, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36860546

RESUMO

It is unclear whether extracellular vesicles (EVs) from mesenchymal stem cells (MSCs) have a direct protective effect on pancreatic islets. In addition, whether culturing MSCs in three dimensions (3D) instead of a monolayer (2D) can induce changes in the cargo of EVs that facilitate the polarization of macrophages into an M2 phenotype has not been investigated. We sought to determine whether EVs from MSCs cultured in 3D can prevent inflammation and dedifferentiation in pancreatic islets and, if so, whether the protective effect is superior to that of EVs from 2D MSCs. Human umbilical cord blood- (hUCB-) MSCs cultured in 3D were optimized according to cell density, exposure to hypoxia, and cytokine treatment based on the ability of the hUCB-MSC-derived EVs to induce the M2 polarization of macrophages. Islets isolated from human islet amyloid polypeptide (hIAPP) heterozygote transgenic mice were cultured in serum-deprived conditions with hUCB-MSC-derived EVs. EVs derived from 3D hUCB-MSCs had more abundant microRNAs involved in M2 polarization of macrophages and had an enhanced M2 polarization ability on macrophages, which was optimized when the 3D culture condition was 2.5 × 104 cells per spheroid without preconditioning with hypoxia and cytokine exposure. When islets isolated from hIAPP heterozygote transgenic mice were cultured in serum-deprived conditions with hUCB-MSC-derived EVs, the EVs derived from 3D hUCB-MSCs suppressed the expression of proinflammatory cytokines and caspase-1 in pancreatic islets and increased the proportion of M2-polarized islet-resident macrophages. They improved glucose-stimulated insulin secretion, reduced the expression of Oct4 and NGN3, and induced the expression of Pdx1 and FoxO1. The greater suppression of IL-1ß, NLRP3 inflammasome, caspase-1, and Oct4 and induction of Pdx1 and FoxO1 were found in islets cultured with the EVs derived from 3D hUCB-MSCs. In conclusion, EVs derived from 3D hUCB-MSCs optimized for M2 polarization attenuated nonspecific inflammation and preserved ß-cell identity of pancreatic islets.

6.
Healthcare (Basel) ; 9(9)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34574890

RESUMO

Self-rated health (SRH) is an evaluation tool to assess an individual's level of health, including both general health and personal experience. There have been existing studies on women's SRH; however, few studies have been on pregnant women's SRH and its associated factors. This study investigated the SRH of pregnant women and their factors using the Korea Community Health Survey. The chi-squared test and multivariable logistic regression were used to investigate the effects of demographic, physical, and mental health and health behaviors on the SRH of pregnant women. As a result of the study, 54.0% out of 1032 pregnant women had good SRH. Their SRH score was good when they were young, economically active, and living in cities. Poor SRH was observed with depression, hypertension, and after experiencing a fall. Good SRH was found when they exercised and slept for more than 8 h a day. This study is the first to observe the SRH of pregnant women and its related factors in South Korea.

7.
Artigo em Inglês | MEDLINE | ID: mdl-34360100

RESUMO

This study aimed to describe the health-related quality of life of elderly women with experience in fall treatment as well as to prepare basic data for the development of interventions to improve the quality of life for this group. The study was based on raw data from the 2019 Korea Community Health Survey. Using the SPSS program, the characteristics of the subjects were tested by frequency, percentage, and chi-square test. To establish the impact of fall experience on the health-related quality of life of elderly women, the OR and 95% CI were calculated using multiple logistic regression analysis. Of the 4260 people surveyed, 44.7% of the elderly women said they had a high quality of life, whereas 55.3% of the elderly women said they had a low quality of life. A younger age was associated with a better-rated health-related quality of life. Those who lived in a city and had a high level of education tended to describe a high quality of life. The quality of life was considered high by those who exercised, but low by those who were obese or diabetic. The results of this study can lead to a better understanding of the experiences of elderly women who have experienced falls, and they can be used as basic data for the development of related health programs.


Assuntos
Acidentes por Quedas , Qualidade de Vida , Idoso , Feminino , Inquéritos Epidemiológicos , Humanos , República da Coreia/epidemiologia , Inquéritos e Questionários
8.
Artigo em Inglês | MEDLINE | ID: mdl-33669926

RESUMO

BACKGROUND: Healthcare information includes sensitive data and, as such, must be secure; however, the risk of healthcare information leakage is increasing. Nurses manage healthcare information in hospitals; however, previous studies have either been conducted on medical workers from various other occupations or have not synthesized various factors. The purpose of this study was to create and prove a model of nurses' healthcare information security (HIS). The hypothetical model used in this study was constructed on the basis of the protection motivation theory (PMT) proposed by Rogers. METHODS: A total of 252 questionnaires scored using a five-point Likert scale were analyzed, incorporating data from nurses who had been working for more than one month in general hospitals with more than 300 beds in South Korea. The survey was conducted over a total of 30 days, from 1 to 30 September 2019. RESULTS: The results showed that coping appraisal significantly influence HIS intentions (estimate = -1.477, p < 0.01), whereas HIS intentions significantly influence HIS behavior (estimate = 0.515, p < 0.001). A moderating effect on the association between coping appraisal and HIS intentions was found in the group of nurses who had been working for <5 years (estimate = -1.820, p < 0.05). Moreover, a moderating effect on the association between HIS intentions and HIS behavior was found in the group of nurses who had been working for <5 years (estimate = 0.600, p < 0.001). CONCLUSION: The results of this study can be used to develop a management plan to strengthen nurses' HIS behavior and can be used by nursing managers as a basis for developing education programs.


Assuntos
Motivação , Enfermeiras e Enfermeiros , Estudos Transversais , Atenção à Saúde , Humanos , Intenção , Modelos Estruturais , República da Coreia , Inquéritos e Questionários
9.
Nanoscale ; 10(33): 15529-15544, 2018 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-29985503

RESUMO

Biofilms adhere to surfaces to produce extracellular polymeric substances (EPSs). EPSs grow and protect themselves from external stresses. Their formation causes a foul odor and may lead to chronic infectious diseases in animals and people. Biofilms also inhibit the contact between bacteria and antibiotics, thereby reducing their antibacterial activity. Thus, we describe novel nanostructures, a fusion of copper and multi-walled carbon nanotubes (MWCNTs), which increase antimicrobial activity against biofilms without being toxic to human cells. Simulations based on the stochastic response were performed to predict the efficiency of synthesizing nanostructures. The synthesized Cu/MWCNTs inhibit the growth of Methylobacterium spp., which forms biofilms; antimicrobial testing and cytotoxicity assessments showed that the Cu/MWCNTs were not cytotoxic to human cells. The Cu/MWCNTs come in direct contact with the bacterial cell surface, damage the cell wall, and cause secondary oxidation of reactive oxygen species. Furthermore, the Cu/MWCNTs release copper ions, which inhibit the quorum sensing in Methylobacterium spp., thereby inhibiting the expression of the genes that form biofilms. Additionally, we confirmed excellent electrical and thermal conductivity of Cu/MWCNTs as well as biofilm removal efficiency in the microfluidic channel.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Cobre/farmacologia , Nanopartículas Metálicas , Nanotubos de Carbono , Linhagem Celular , Humanos , Methylobacterium/efeitos dos fármacos , Testes de Sensibilidade Microbiana
10.
Anal Sci ; 32(1): 67-73, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26753708

RESUMO

In recent years, a microfluidic technology has contributed a significant role in biological research, specifically for the study of biofilms. Bacterial biofilms are a source of infections and contamination in the environment due to an extra polymeric matrix. Inadequate uses of antibiotics make the bacterial biofilms antibiotic resistant. Therefore, it is important to determine the effective concentration of antibiotics in order to eliminate bacterial biofilms. The present microfluidic study was carried out to analyze the activities of tobramycin and sodium dodecyl sulfate (SDS) against Pseudomonas aeruginosa biofilms with a continuous flow in order to achieve a greater delivery of the agents. The results show that a co-treatment of tobramycin and SDS significantly reduced the biomass of biofilms (by more than 99%) after 24 h. Tobramycin and SDS killed and detached bacteria in the cores of biofilms. Evidently, our data suggest that a microchannel would be effective for both quantitative and qualitative evaluations in order to test combinatorial effect of drugs and chemicals on a complexed biological system including biofilm.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Técnicas Analíticas Microfluídicas/métodos , Pseudomonas aeruginosa/efeitos dos fármacos , Dodecilsulfato de Sódio/farmacologia , Tobramicina/farmacologia , Antibacterianos/administração & dosagem , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Vidro/química , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Microscopia Confocal , Pseudomonas aeruginosa/crescimento & desenvolvimento , Dodecilsulfato de Sódio/administração & dosagem , Tobramicina/administração & dosagem
11.
Colloids Surf B Biointerfaces ; 142: 290-296, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26966999

RESUMO

Iron oxide nanoparticles have been used in a wide range of biomedical applications, including drug delivery, molecular imaging, and cellular imaging. Various surface modifications have been applied to the particles to stabilize their surface and to give them a moiety for anchoring tags and/or drug molecules. Conventional methods of delivering immunosuppressant drugs often require a high dose of drugs to ensure therapeutic effects, but this can lead to toxic side effects. In this study, we used silica-coated iron oxide nanoparticles (IOSs) for a drug delivery application in which the nanoparticles carry the minimum amount of drug required to be effective to the target cells. IOSs could be loaded with water-insoluble immunosuppressive drug molecules (MPA: mycophenolic acid) and be used as a contrast agent for MRI. We characterized the IOSs for their physicochemical properties and found their average hydrodynamic diameter and core size to be 40.5nm and 5nm, respectively. Following the introduction of MPA-loaded IOSs (IOS/M), we evaluated the secretion dynamics of cytokines from peripheral blood mononuclear cells stimulated with phytohemagglutinin (PHA). The results showed that IOS/M effectively inhibited the secretion of the cytokines interleukin-2 and tumor necrosis factor α, with a minimal concentration of MPA. In conclusion, IOS/M may have potential applications in both efficient drug delivery and MRI.


Assuntos
Portadores de Fármacos , Compostos Férricos/química , Imunossupressores/farmacologia , Nanopartículas de Magnetita/química , Ácido Micofenólico/farmacologia , Dióxido de Silício/química , Sobrevivência Celular/efeitos dos fármacos , Composição de Medicamentos , Liberação Controlada de Fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imunossupressores/química , Interleucina-2/antagonistas & inibidores , Interleucina-2/biossíntese , Interleucina-2/metabolismo , Cinética , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Nanopartículas de Magnetita/ultraestrutura , Ácido Micofenólico/química , Tamanho da Partícula , Fito-Hemaglutininas/farmacologia , Cultura Primária de Células , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/metabolismo
12.
Transpl Immunol ; 28(2-3): 86-92, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23357716

RESUMO

Retransplantation is common in allogeneic islet transplantation, and therefore, memory responses in previously sensitized recipients present a distinct obstacle for successful islet transplantation. Given the difficulties in controlling memory responses contributing to allograft rejection, it is worth investigating the effects of new immune-modulating agents against islet allograft rejection in the sensitized recipients. In this study, we investigated immune-modulating agents including 5-azacytidine and IL-2/anti-IL-2 complex to ascertain their suppressive effects on memory responses. In suppression assays, rapamycin effectively suppressed the proliferation of memory T cells, whereas 5-azacytidine, a methylation inhibitor suppressed the survival and proliferation of memory T cells. Combination therapy of anti-CD40L, anti-OX40L, and rapamycin slightly prolonged BALB/c islet allograft survival in sensitized C57BL6 mice, and reduced intragraft infiltration of macrophages, T cells, and B cells. However, the addition of IL-2/anti-IL-2 complex, an inducer of regulatory T cells, did not exhibit additional suppression against rejection in sensitized mice. Although a combination of 5-azacytidine and rapamycin markedly suppressed islet allograft rejection in naïve mice, it failed to achieve long-term graft survival even when combined with anti-CD40L and anti-OX40 in sensitized mice. In short, 5-azacytidine-based or IL-2/anti-IL-2 complex-based regimens can suppress islet allograft rejection in naïve recipients, but fail to control islet allograft rejection in sensitized recipients.


Assuntos
Rejeição de Enxerto/imunologia , Imunossupressores/uso terapêutico , Transplante das Ilhotas Pancreáticas/imunologia , Sirolimo/uso terapêutico , Animais , Ligante de CD40/imunologia , Proliferação de Células/efeitos dos fármacos , Rejeição de Enxerto/tratamento farmacológico , Memória Imunológica , Interleucina-2/imunologia , Camundongos , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Transplante Homólogo
13.
Inorg Chem ; 41(3): 501-6, 2002 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-11825076

RESUMO

A novel Co-glutarate, Co[O(2)C(CH(2))(3)CO(2)] (1), was synthesized as single crystals by the hydrothermal reaction of CoCl(2) with glutaric acid in the presence of KOH and characterized by single-crystal X-ray diffraction analysis, TGA, IR, UV-vis reflectance spectrometry, and SQUID measurements. The dark purple Co-glutarate crystallizes in the monoclinic system in the space group P2/c, with a = 14.002(3) A, b = 4.8064(10) A, c = 9.274(3) A, beta = 90.5(2)degrees, and Z = 4. The Co(2+) centers are tetrahedrally coordinated to four oxygen atoms from the dicarboxylate ligands. The anhydrous-pillared three-dimensional structure consists of infinite Co-CO(2)-Co inorganic layers, which are stacked by the coordinated glutarate alkyl chain along the a-axis. There are two different conformations for glutarate ligands, i.e., the gauche- and the anti-forms. These ligands reside between the inorganic layers alternatively to separate each layer by 7.01 A (gauche) and 6.99 A (anti). Magnetic measurement reveals that the predominant magnetic interactions are antiferromagnetic below 14 K.

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