Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Sensors (Basel) ; 23(3)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36772749

RESUMO

In recent years, deep learning (DL) has been widely studied using various methods across the globe, especially with respect to training methods and network structures, proving highly effective in a wide range of tasks and applications, including image, speech, and text recognition. One important aspect of this advancement is involved in the effort of designing and upgrading neural architectures, which has been consistently attempted thus far. However, designing such architectures requires the combined knowledge and know-how of experts from each relevant discipline and a series of trial-and-error steps. In this light, automated neural architecture search (NAS) methods are increasingly at the center of attention; this paper aimed at summarizing the basic concepts of NAS while providing an overview of recent studies on the applications of NAS. It is worth noting that most previous survey studies on NAS have been focused on perspectives of hardware or search strategies. To the best knowledge of the present authors, this study is the first to look at NAS from a computer vision perspective. In the present study, computer vision areas were categorized by task, and recent trends found in each study on NAS were analyzed in detail.

2.
Int J Mol Sci ; 24(20)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37894970

RESUMO

Apoptosis has historically been considered the primary form of programmed cell death (PCD) and is responsible for regulating cellular processes during development, homeostasis, and disease. Conversely, necrosis was considered uncontrolled and unregulated. However, recent evidence has unveiled the significance of necroptosis, a regulated form of necrosis, as an important mechanism of PCD alongside apoptosis. The activation of necroptosis leads to cellular membrane disruption, inflammation, and vascularization. This process is crucial in various pathological conditions, including intervertebral disc degeneration (IVDD), neurodegeneration, inflammatory diseases, multiple cancers, and kidney injury. In recent years, extensive research efforts have shed light on the molecular regulation of the necroptotic pathway. Various stimuli trigger necroptosis, and its regulation involves the activation of specific proteins such as receptor-interacting protein kinase 1 (RIPK1), RIPK3, and the mixed lineage kinase domain-like (MLKL) pseudokinase. Understanding the intricate mechanisms governing necroptosis holds great promise for developing novel therapeutic interventions targeting necroptosis-associated IVDD. The objective of this review is to contribute to the growing body of scientific knowledge in this area by providing a comprehensive overview of necroptosis and its association with IVDD. Ultimately, these understandings will allow the development of innovative drugs that can modulate the necroptotic pathway, offering new therapeutic avenues for individuals suffering from necroptosis.


Assuntos
Degeneração do Disco Intervertebral , Proteínas Quinases , Humanos , Proteínas Quinases/metabolismo , Necroptose/fisiologia , Apoptose , Necrose/patologia , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo
3.
Molecules ; 28(11)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37299026

RESUMO

We investigated the effects of four coumarin derivatives, namely, 6-methylcoumarin, 7-methylcoumarin, 4-hydroxy-6-methylcoumarin, and 4-hydroxy-7-methylcoumarin, which have similar structures on melanogenesis in a murine melanoma cell line from a C57BL/6J mouse called B16F10. Our results showed that only 6-methylcoumarin significantly increased the melanin synthesis in a concentration-dependent manner. In addition, the tyrosinase, TRP-1, TRP-2, and MITF protein levels were found to significantly increase in response to 6-methylcoumarin in a concentration-dependent manner. To elucidate the molecular mechanism whereby 6-methylcoumarin-induced melanogenesis influences the melanogenesis-related protein expression and melanogenesis-regulating protein activation, we further assessed the B16F10 cells. The inhibition of the ERK, Akt, and CREB phosphorylation, and conversely, the increased p38, JNK, and PKA phosphorylation activated the melanin synthesis via MITF upregulation, which ultimately led to increased melanin synthesis. Accordingly, 6-methylcoumarin increased the p38, JNK, and PKA phosphorylation in the B16F10 cells, whereas it decreased the phosphorylated ERK, Akt, and CREB expressions. In addition, the 6-methylcoumarin activated GSK3ß and ß-catenin phosphorylation and reduced the ß-catenin protein level. These results suggest that 6-methylcoumarin stimulates melanogenesis through the GSK3ß/ß-catenin signal pathway, thereby affecting the pigmentation process. Finally, we tested the safety of 6-methylcoumarin for topical applications using a primary human skin irritation test on the normal skin of 31 healthy volunteers. We found that 6-methylcoumarin did not cause any adverse effects at concentrations of 125 and 250 µM. Our findings indicate that 6-methylcoumarin may be an effective pigmentation stimulator for use in cosmetics and the medical treatment of photoprotection and hypopigmentation disorders.


Assuntos
Melanoma Experimental , Proteínas Proto-Oncogênicas c-akt , Humanos , Animais , Camundongos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Melaninas , beta Catenina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Camundongos Endogâmicos C57BL , Transdução de Sinais , Cumarínicos/farmacologia , Monofenol Mono-Oxigenase , Linhagem Celular Tumoral , Melanoma Experimental/metabolismo
4.
Molecules ; 27(10)2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35630676

RESUMO

Drug repurposing is a simple concept with a long history, and is a paradigm shift that can significantly reduce the costs and accelerate the process of bringing a new small-molecule drug into clinical practice. We attempted to uncover a new application of spiramycin, an old medication that was classically prescribed for toxoplasmosis and various other soft-tissue infections; specifically, we initiated a study on the anti-inflammatory capacity of spiramycin. For this purpose, we used murine macrophage RAW 264.7 as a model for this experiment and investigated the anti-inflammatory effects of spiramycin by inhibiting the production of pro-inflammatory mediators and cytokines. In the present study, we demonstrated that spiramycin significantly decreased nitric oxide (NO), interleukin (IL)-1ß, and IL-6 levels in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Spiramycin also inhibited the expression of NO synthase (iNOS), potentially explaining the spiramycin-induced decrease in NO production. In addition, spiramycin inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs); extracellular signal-regulated kinase (ERK) and c-Jun N terminal kinase (JNK) as well as the inactivation and subsequent nuclear translocation of nuclear factor κB (NF-κB). This indicated that spiramycin attenuates macrophages' secretion of IL-6, IL-1ß, and NO, inducing iNOS expression via the inhibition of the NF-κB and MAPK signaling pathways. Finally, we tested the potential application of spiramycin as a topical material by human skin primary irritation tests. It was performed on the normal skin (upper back) of 31 volunteers to determine whether 100 µM and µM of spiramycin had irritation or sensitization potential. In these assays, spiramycin did not induce any adverse reactions. In conclusion, our results demonstrate that spiramycin can effectively attenuate the activation of macrophages, suggesting that spiramycin could be a potential candidate for drug repositioning as a topical anti-inflammatory agent.


Assuntos
Anti-Inflamatórios , Macrófagos , Espiramicina , Animais , Anti-Inflamatórios/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Inflamação/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos , Macrófagos/efeitos dos fármacos , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Células RAW 264.7 , Espiramicina/farmacologia
5.
Molecules ; 26(17)2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34500784

RESUMO

Persistent inflammatory reactions promote mucosal damage and cause dysfunction, such as pain, swelling, seizures, and fever. Therefore, in this study, in order to explore the anti-inflammatory effect of 6-methylcoumarin (6-MC) and suggest its availability, macrophages were stimulated with lipopolysaccharide (LPS) to conduct an in vitro experiment. The effects of 6-MC on the production and levels of pro-inflammatory cytokines (interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α) and inflammatory mediators (nitric oxide (NO), prostaglandin E2 (PGE2)) in LPS-stimulated RAW 264.7 cells were examined. The results showed that 6-MC reduced the levels of NO and PGE2 without being cytotoxic. In addition, it was demonstrated that the increase in the expression of pro-inflammatory cytokines caused by LPS stimulation, was decreased in a concentration-dependent manner with 6-MC treatment. Moreover, Western blot results showed that the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which increased with LPS treatment, were decreased by 6-MC treatment. Mechanistic studies revealed that 6-MC reduced the phosphorylation of the mitogen-activated protein kinase (MAPK) family and IκBα in the MAPK and nuclear factor-kappa B (NF-κB) pathways, respectively. These results suggest that 6-MC is a potential therapeutic agent for inflammatory diseases that inhibits inflammation via the MAPK and NF-κB pathways.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Cumarínicos/farmacologia , Macrófagos/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Animais , Anti-Inflamatórios não Esteroides/química , Linhagem Celular Tumoral , Cumarínicos/química , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estrutura Molecular , NF-kappa B/metabolismo , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Fosforilação/efeitos dos fármacos , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos
6.
Environ Geochem Health ; 43(9): 3303-3321, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33034807

RESUMO

Biochar derived from food waste was modified with Fe to enhance its adsorption capacity for As(III), which is the most toxic form of As. The synthesis of Fe-impregnated food waste biochar (Fe-FWB) was optimized using response surface methodology (RSM), and the pyrolysis time (1.0, 2.5, and 4.0 h), temperature (300, 450, and 600 °C), and Fe concentration (0.1, 0.3, and 0.5 M) were set as independent variables. The pyrolysis temperature and Fe concentration significantly influenced the As(III) removal, but the effect of pyrolysis time was insignificant. The optimum conditions for the synthesis of Fe-FWB were 1 h and 300 °C with a 0.42-M Fe concentration. Both physical and chemical properties of the optimized Fe-FWB were studied. They were also used for kinetic, equilibrium, thermodynamic, pH, and competing anion studies. Kinetic adsorption experiments demonstrated that the pseudo-second-order model had a superior fit for As(III) adsorption than the pseudo-first-order model. The maximum adsorption capacity derived from the Langmuir model was 119.5 mg/g, which surpassed that of other adsorbents published in the literature. Maximum As(III) adsorption occurred at an elevated pH in the range from 3 to 11 owing to the presence of As(III) as H2AsO3- above a pH of 9.2. A slight reduction in As(III) adsorption was observed in the existence of bicarbonate, hydrogen phosphate, nitrate, and sulfate even at a high concentration of 10 mM. This study demonstrates that aqueous solutions can be treated using Fe-FWB, which is an affordable and readily available resource for As(III) removal.


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Alimentos , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análise
7.
Magn Reson Med ; 81(4): 2644-2654, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30478857

RESUMO

PURPOSE: To develop and evaluate an integrated motion correction and dictionary learning (MoDic) technique to accelerate data acquisition for myocardial T1 mapping with improved accuracy. METHODS: MoDic integrates motion correction with dictionary learning-based reconstruction. A random undersampling scheme was implemented for slice-interleaved T1 mapping sequence to allow prospective undersampled data acquisition. Phantom experiments were performed to evaluate the effect of reconstruction on T1 measurement. In vivo T1 mappings were acquired in 8 healthy subjects using 6 different acceleration approaches: uniform or randomly undersampled k-space data with reduction factors (R) of 2, 3, and 4. Uniform undersampled data were reconstructed with SENSE, and randomly undersampled k-space data were reconstructed using dictionary learning, compressed sensing SENSE, and MoDic methods. Three expert readers subjectively evaluated the quality of T1 maps using a 4-point scoring system. The agreement between T1 values was assessed by Bland-Altman analysis. RESULTS: In the phantom study, the accuracy of T1 measurements improved with increasing reduction factors ( - 31 ± 35 ms, - 13 ± 18 ms, and - 5 ± 11 ms for reduction factor (R) = 2 to 4, respectively). The image quality of in vivo T1 maps assessed by subjective scoring using MoDic was similar to that of SENSE at R = 2 (P = .61) but improved at R = 3 and 4 (P < .01). The scores of dictionary learning (2.98 ± 0.71, 2.91 ± 0.60, and 2.67 ± 0.71 for R = 2 to 4) and CS-SENSE (3.32 ± 0.42, 3.05 ± 0.43, and 2.53 ± 0.43) were lower than those of MoDic (3.48 ± 0.46, 3.38 ± 0.52, and 2.9 ± 0.60) for all reduction factors (P < .05 for all). CONCLUSION: The MoDic method accelerates data acquisition for myocardial T1 mapping with improved T1 measurement accuracy.


Assuntos
Coração/diagnóstico por imagem , Imageamento por Ressonância Magnética , Miocárdio/patologia , Respiração , Adulto , Idoso , Algoritmos , Artefatos , Feminino , Voluntários Saudáveis , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Imagens de Fantasmas , Estudos Prospectivos , Reprodutibilidade dos Testes
8.
Magn Reson Med ; 81(1): 153-166, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30058162

RESUMO

PURPOSE: To develop a black blood heart-rate adaptive T2 -prepared balanced steady-state free-precession (BEATS) sequence for myocardial T2 mapping. METHODS: In BEATS, blood suppression is achieved by using a combination of preexcitation and double inversion recovery pulses. The timing and flip angles of the preexcitation pulse are auto-calculated in each patient based on heart rate. Numerical simulations, phantom studies, and in vivo studies were conducted to evaluate the performance of BEATS. BEATS T2 maps were acquired in 36 patients referred for clinical cardiac MRI and in 1 swine with recent myocardial infarction. Two readers assessed all images acquired in patients to identify the presence of artifacts associated with slow blood flow. RESULTS: Phantom experiments showed that the BEATS sequence provided accurate T2 values over a wide range of simulated heart rates. Black blood myocardial T2 maps were successfully obtained in all subjects. No significant difference was found between the average T2 measurements obtained from the BEATS and conventional bright-blood T2 ; however, there was a decrease in precision using the BEATS sequence. A suppression of the blood pool resulted in sharper definition of the blood-myocardium border and reduced partial voluming effect. The subjective assessment showed that 16% (18 out of 108) of short-axis slices have residual blood artifacts (12 in the apical slice, 4 in the midventricular slice, and 2 in the basal slice). CONCLUSION: The BEATS sequence yields dark blood myocardial T2 maps with better definition of the blood-myocardium border. Further studies are warranted to evaluate diagnostic accuracy of black blood T2 mapping.


Assuntos
Velocidade do Fluxo Sanguíneo , Imageamento por Ressonância Magnética , Miocárdio/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Animais , Artefatos , Simulação por Computador , Feminino , Coração , Frequência Cardíaca , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Imagens de Fantasmas , Processamento de Sinais Assistido por Computador , Suínos , Adulto Jovem
9.
Jpn J Clin Oncol ; 48(6): 548-554, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29722825

RESUMO

BACKGROUND: There is growing interest in the use of stereotactic ablative radiotherapy (SABR) for oligometastases. However, extreme caution should be exercised in treating tumors closely located to organs at risk (OARs) with SABR. To reduce complications, we have applied split-course SABR to oligometastases closely located to OARs or to those being retreated with radiotherapy. METHODS: We retrospectively reviewed the records of patients with oligometastases who were treated with planned split-course SABR between January 2012 and December 2016. RESULTS: A total of 23 patients with 29 oligometastatic lesions were enrolled. The primary diagnoses were bone and soft tissue cancers in 13 lesions, liver cancers in 12 lesions, and colorectal cancers in four lesions. The median tumor volume was 78 cm3 (range, 4-1781 cm3). The lesions were treated with 1-3 fractions in the first stage of SABR (first SABR), and one or two fractions in the second stage of SABR (second SABR). The time interval between the two stages was about 4 weeks. A partial response was noted in 16 lesions (55%) after the first SABR, and practical reductions in the doses to OARs were observed in the second SABR compared with the first SABR. The 1-, 2- and 3-year local control rates were 92%, 65% and 43%, respectively. No Grade 4 or 5 toxicities were observed during or after treatment. CONCLUSION: Split-course SABR appeared to be feasible for the treatment of oligometastases closely located to OARs.


Assuntos
Metástase Neoplásica/radioterapia , Radiocirurgia , Adulto , Idoso , Neoplasias Colorretais/radioterapia , Neoplasias Colorretais/secundário , Relação Dose-Resposta à Radiação , Estudos de Viabilidade , Feminino , Humanos , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Órgãos em Risco , Radiocirurgia/efeitos adversos , Estudos Retrospectivos , Carga Tumoral
10.
Toxicol Appl Pharmacol ; 329: 40-47, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28526636

RESUMO

Radiation-induced enteritis is a major side effect in cancer patients undergoing abdominopelvic radiotherapy. Radiation exposure produces an uncontrolled inflammatory cascade and epithelial cell loss leading to impaired epithelial barrier function. The goal of this study was to determine the effect of rebamipide on regeneration of the intestinal epithelia after radiation injury. The abdomens of C57BL/6 mice were exposed to 13Gy of irradiation (IR) and then the mice were treated with rebamipide. Upon IR, intestinal epithelia were destroyed structurally at the microscopic level and bacterial translocation was increased. The intestinal damage reached a maximum level on day 6 post-IR and intestinal regeneration occurred thereafter. We found that rebamipide significantly ameliorated radiation-induced intestinal injury. In mice treated with rebamipide after IR, intestinal barrier function recovered and expression of the tight junction components of the intestinal barrier were upregulated. Rebamipide administration reduced radiation-induced intestinal mucosal injury. The levels of proinflammatory cytokines and matrix metallopeptidase 9 (MMP9) were significantly reduced upon rebamipide administration. Intestinal cell proliferation and ß-catenin expression also increased upon rebamipide administration. These data demonstrate that rebamipide reverses impairment of the intestinal barrier by increasing intestinal cell proliferation and attenuating the inflammatory response by inhibiting MMP9 and proinflammatory cytokine expression in a murine model of radiation-induced enteritis.


Assuntos
Alanina/análogos & derivados , Enterite/prevenção & controle , Células Epiteliais/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Quinolonas/farmacologia , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/farmacologia , Alanina/farmacologia , Animais , Translocação Bacteriana/efeitos dos fármacos , Translocação Bacteriana/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Citoproteção , Relação Dose-Resposta a Droga , Enterite/metabolismo , Enterite/patologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Células Epiteliais/efeitos da radiação , Mediadores da Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Mucosa Intestinal/efeitos da radiação , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos C57BL , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Junções Íntimas/patologia , Junções Íntimas/efeitos da radiação , Fatores de Tempo , beta Catenina/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-27960653

RESUMO

The aim of this study was to quantify the interactions between graphene oxide (GO) and quartz sand by conducting experimental and modeling analyses. The results show that both GO and quartz sand were negatively charged in the presence of 0-50 mM NaCl and 5 mM CaCl2 (GO = -43.10 to -17.60 mV, quartz sand = -40.97 to -8.44 mV). In the Derjaguin-Landau-Verwey-Overbeek (DLVO) energy profiles, the adhesion of GO to quartz sand becomes more favorable with increasing NaCl concentration from 0 to 10 mM because the interaction energy profile was compressed and the primary maximum energy barrier was lowered. At 50 mM NaCl and 5 mM CaCl2, the primary maximum energy barrier even disappeared, resulting in highly favorable conditions for GO retention to quartz sand. In the Maxwell model analysis, the probability of GO adhesion to quartz sand (αm) increased from 2.46 × 10-4 to 9.98 × 10-1 at ionic strengths of 0-10 mM NaCl. In the column experiments (column length = 10 cm, inner diameter = 2.5 cm, flow rate = 0.5 mL min-1), the mass removal (Mr) of GO in quartz sand increased from 5.4% to 97.8% as the NaCl concentration was increased from 0 to 50 mM, indicating that the mobility of GO was high in low ionic strength solutions and decreased with increasing ionic strength. The Mr value of GO at 5 mM CaCl2 was 100%, demonstrating that Ca2+ had a much stronger effect than Na+ on the mobility of GO. In addition, the mobility of GO was lower than that of chloride (Mr = 1.4%) but far higher than that of multi-walled carbon nanotubes (Mr = 87.0%) in deionized water. In aluminum oxide-coated sand, the Mr value of GO was 98.1% at 0 mM NaCl, revealing that the mobility of GO was reduced in the presence of metal oxides. The transport model analysis indicates that the value of the dimensionless attachment rate coefficient (Da) increased from 0.11 to 4.47 as the NaCl concentration was increased from 0 to 50 mM. In the colloid filtration model analysis, the probability of GO sticking to quartz sand (αf) increased from 6.23 × 10-3 to 2.52 × 10-1 as the NaCl concentration was increased from 0 to 50 mM.


Assuntos
Grafite/química , Óxidos/química , Quartzo/química , Poluentes Químicos da Água/química , Modelos Teóricos
12.
Artigo em Inglês | MEDLINE | ID: mdl-28920769

RESUMO

The aim of this study was to investigate Cr(VI) removal from chromium-plating rinse water using modacrylic anion-exchange fibers (KaracaronTM KC31). Batch experiments were performed with synthetic Cr(VI) solutions to characterize the KC31 fibers in Cr(VI) removal. Cr(VI) removal by the fibers was affected by solution pH; the Cr(VI) removal capacity was the highest at pH 2 and decreased gradually with a pH increase from 2 to 12. In regeneration and reuse experiments, the Cr(VI) removal capacity remained above 37.0 mg g-1 over five adsorption-desorption cycles, demonstrating that the fibers could be successfully regenerated with NaCl solution and reused. The maximum Cr(VI) removal capacity was determined to be 250.3 mg g-1 from the Langmuir model. In Fourier-transform infrared spectra, a Cr = O peak newly appeared at 897 cm-1 after Cr(VI) removal, whereas a Cr-O peak was detected at 772 cm-1 due to the association of Cr(VI) ions with ion-exchange sites. X-ray photoelectron spectroscopy analyses demonstrated that Cr(VI) was partially reduced to Cr(III) after the ion exchange on the surfaces of the fibers. Batch experiments with chromium-plating rinse water (Cr(VI) concentration = 1178.8 mg L-1) showed that the fibers had a Cr(VI) removal capacity of 28.1-186.4 mg g-1 under the given conditions (fiber dose = 1-10 g L-1). Column experiments (column length = 10 cm, inner diameter = 2.5 cm) were conducted to examine Cr(VI) removal from chromium-plating rinse water by the fibers under flow-through column conditions. The Cr(VI) removal capacities for the fibers at flow rates of 0.5 and 1.0 mL min-1 were 214.8 and 171.5 mg g-1, respectively. This study demonstrates that KC31 fibers are effective in the removal of Cr(VI) ions from chromium-plating rinse water.


Assuntos
Resinas Acrílicas/química , Resinas de Troca Aniônica/química , Cromo/análise , Cloreto de Polivinila/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Cromo/química , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/química
13.
J Nanosci Nanotechnol ; 14(10): 7938-42, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25942898

RESUMO

We synthesized novel organic photosensitizers based on fluorine-substituted phenothiazine with thiophene bridge units in the chromophore for application in dye-sensitized solar cells (DSSCs). Furthermore, organic dyes with different acceptors exhibited higher molar extinction coefficients, and better light absorption at longer wavelengths. The photovoltaic properties of organic dyes composed of different acceptors in their chromophores were measured to identify their effects on the DSSC performance. The organic dye, PFSCN2 containing multi-cyanoacrylic acid as the electron acceptor, showed a power conversion efficiency of 4.67% under AM 1.5 illumination (100 mW/cm2). The retarded recombination kinetics from TiO2 electrode to electrolyte enhanced the electron life time of the organic dye, PFSCN2 in the photoanode of the DSSC. This was confirmed with impedance analysis.


Assuntos
Corantes/química , Fontes de Energia Elétrica , Fenotiazinas/química , Energia Solar , Absorção de Radiação , Eletroquímica , Luz , Fenômenos Ópticos
14.
Environ Technol ; 35(9-12): 1199-207, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24701916

RESUMO

The aim of this study was to investigate the removal of bacteriophages MS2 and PhiX174 in soils amended with converter furnace steel slag. Column experiments were performed to examine the bacteriophage removal in slag-amended (slag content: 0%, 25%, and 50%) loam soils. For comparison, column experiments were also conducted with Escherichia coli. In addition, chloride (Cl) was used as a conservative tracer to determine transport characteristics. Results showed mass recoveries of Cl of 98.6 +/- 3.5%, indicating that the experiments were conducted successfully. The mass recovery of MS2 was 86.7% in no slag (100% soil), decreasing to 0% in slag contents of 25% and 50%. The mass recovery of PhiX174 decreased from 87.8% to 51.5% with increasing slag content from 0% to 50%. In the case of E. coli, the mass recoveries decreased from 47.0% to 10.5% with increasing slag content from 0% to 50%. In the transport models analyses, the HYDRUS-1D code was used to quantify the sorption parameters from breakthrough curves. For the 100% soil column, a one-site kinetic sorption model was fitted to the data, whereas a two-site kinetic sorption model was fitted for slag-amended (25% and 50% slag) soil data. Results demonstrate that the addition of steel slag to soil enhances the removal of bacteriophages due to the presence of FeO in the steel slag. However, CaO could not contribute to the bacteriophage removal in our experimental conditions because the effluent pH (7.7-8.9) in slag-amended (25% and 50% slag) soils was not high enough to promote the bacteriophage inactivation.


Assuntos
Bacteriófago phi X 174/isolamento & purificação , Levivirus/isolamento & purificação , Óxidos/farmacologia , Microbiologia do Solo , Poluentes do Solo/isolamento & purificação , Bacteriófago phi X 174/efeitos dos fármacos , Levivirus/efeitos dos fármacos , Modelos Teóricos
15.
Sci Total Environ ; 926: 171753, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38522552

RESUMO

Removing perfluoro(2-methyl-3-oxahexanoic) acid (HFPO-DA) in water treatment is hindered by its hydrophobicity and negative charge. Two adsorbents, quaternary-ammonium-functionalized silica gel (Qgel), specifically designed for anionic hydrophobic compounds, and conventional granular activated carbon (GAC) were investigated for HFPO-DA removal. ANOVA results (p â‰ª 0.001) revealed significant effects on initial concentration, contact time, and adsorbent type. Langmuir model-derived capacities were 285.019 and 144.461 mg/g for Qgel and GAC, respectively, with Qgel exhibiting higher capacity irrespective of pH. In column experiments, selective removal of HFPO-DA removal with Qgel was observed; specifically, in the presence of NaCl, the breakthrough time was extended by 10 h from 26 to 36 h. Meanwhile, the addition of NaCl decreased the breakthrough time from 32 to 14 h for GAC. However, in the presence of carbamazepine, neither of the adsorbents significantly changed the breakthrough time for HFPO-DA. Molecular simulations were also used to compare the adsorption energies and determine the preferential interactions of HFPO-DA and salts or other chemicals with Qgel and GAC. Molecular simulations compared adsorption energies, revealing preferential interactions with Qgel and GAC. Notably, HFPO-DA adsorption energy on GAC surpassed other ions during coexistence. Specifically, with Cl- concentrations from 1 to 10 times, Qgel showed lower adsorption energy for HFPO-DA (-62.50 ± 5.44 eV) than Cl- (-52.89 ± 2.59 eV), a significant difference (p = 0.036). Conversely, GAC exhibited comparable or higher adsorption energy for HFPO-DA (-18.33 ± 40.38 eV) than Cl- (-32.36 ± 29.89 eV), with no significant difference (p = 0.175). This suggests heightened selectivity of Qgel for HFPO-DA removal compared to GAC. Consequently, our study positions Qgel as a promising alternative for effective HFPO-DA removal, contributing uniquely to the field. Additionally, our exploration of molecular simulations in predicting micropollutant removal adds novelty to our study.

16.
Water Res ; 252: 121130, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38295453

RESUMO

In this study, the strong analytical power of gas chromatography coupled to a high resolution mass spectrometry (GC-HRMS) in suspect and non-target screening (SNTS) of organic micropollutants was combined with machine learning tools for proposing a novel and robust systematic environmental forensics workflow, focusing on groundwater contamination. Groundwater samples were collected from four different regions with diverse contamination histories (namely oil [OC], agricultural [AGR], industrial [IND], and landfill [LF]), and a total of 252 organic micropollutants were identified, including pharmaceuticals, personal care products, pesticides, polycyclic aromatic hydrocarbons, plasticizers, phenols, organophosphate flame retardants, transformation products, and others, with detection frequencies ranging from 3 % to 100 %. Amongst the SNTS identified compounds, a total of 51 chemical indicators (i.e., OC: 13, LF: 12, AGR: 19, IND: 7) which included level 1 and 2 SNTS identified chemicals were pinpointed across all sampling regions by integrating a bootstrapped feature selection method involving the bootfs algorithm and a partial least squares discriminant analysis (PLS-DA) model to determine potential prevalent contamination sources. The proposed workflow showed good predictive ability (Q2) of 0.897, and the suggested contamination sources were gasoline, diesel, and/or other light petroleum products for the OC region, anthropogenic activities for the LF region, agricultural and human activities for the AGR region, and industrial/human activities for the IND region. These results suggest that the proposed workflow can select a subset of the most diagnostic features in the chemical space that can best distinguish a specific contamination source class.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Humanos , Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas , Poluição Ambiental/análise , Compostos Orgânicos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise
17.
Int J Radiat Oncol Biol Phys ; 118(2): 337-351, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37597757

RESUMO

This systematic review and meta-analysis reports on outcomes and hepatic toxicity rates after stereotactic body radiation therapy (SBRT) for liver-confined hepatocellular carcinoma (HCC) and presents consensus guidelines regarding appropriate patient management. Using the Preferred Reporting Items for Systemic Review and Meta-Analyses guidelines, a systematic review was performed from articles reporting outcomes at ≥5 years published before October 2022 from the Embase, MEDLINE, Cochrane, and Scopus databases with the following search terms: ("stereotactic body radiotherapy" OR "SBRT" OR "SABR" OR "stereotactic ablative radiotherapy") AND ("hepatocellular carcinoma" OR "HCC"). An aggregated data meta-analysis was conducted to assess overall survival (OS) and local control (LC) using weighted random effects models. In addition, individual patient data analyses incorporating data from 6 institutions were conducted as their own subgroup analyses. Seventeen observational studies, comprising 1889 patients with HCC treated with ≤9 SBRT fractions, between 2003 and 2019, were included in the aggregated data meta-analysis. The 3- and 5-year OS rates after SBRT were 57% (95% confidence interval [CI], 47%-66%) and 40% (95% CI, 29%-51%), respectively. The 3- and 5-year LC rates after SBRT were 84% (95% CI, 77%-90%) and 82% (95% CI, 74%-88%), respectively. Tumor size was the only prognostic factor for LC. Tumor size and region were significantly associated with OS. Five-year LC and OS rates of 79% (95% CI, 0.74-0.84) and 25% (95% CI, 0.20-0.30), respectively, were observed in the individual patient data analyses. Factors prognostic for improved OS were tumor size <3 cm, Eastern region, Child-Pugh score ≤B7, and the Barcelona Clinic Liver Cancer stage of 0 and A. The incidence of severe hepatic toxicity varied according to the criteria applied. SBRT is an effective treatment modality for patients with HCC with mature follow-up. Clinical practice guidelines were developed on behalf of the International Stereotactic Radiosurgery Society (ISRS).


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Radiocirurgia , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Radiocirurgia/efeitos adversos , Resultado do Tratamento , Estudos Retrospectivos
18.
J Nanosci Nanotechnol ; 13(6): 4211-5, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23862475

RESUMO

We have investigated the effects of the addition of tantalum (Ta) and yttrium (Y) ions to InZnO thin film transistors (TFTs) using the sol-gel process. TaInZnO and YInZnO TFTs had significantly lower off current and higher on-to-off current ratio than InZnO TFTs. Ta and Y ions have strong affinity to oxygen and so suppress the formation of free electron carriers in thin films; they play an important role in enhancing the electrical characteristic due to their high oxygen bonding ability. The optimized TaInZnO and YInZnO TFTs showed high on/off ratio and low subthreshold swing.

19.
Environ Technol ; 34(5-8): 703-10, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23837321

RESUMO

The aim of this study was to investigate the adhesion of bacteria (Escherichia coli) to pyrophyllite clay using batch and flow-through column experiments. Batch results demonstrated that pyrophyllite was effective in removing bacteria (94.5 +/- 2.0%) from aqueous solution (1 mM NaCl solution; pyrophyllite dose of 1 g/ml). At solution pH 7.1, negatively-charged bacteria could be removed due to their adhesion to positively-charged surfaces of pyrophyllite (point of zero charge = 9.2). Column results showed that pyrophyllite (per cent removal of 94.1 +/- 2.3%) was far more effective in bacterial adhesion than quartz sand (53.6 +/- 5.3%) under the given experimental conditions (flow rate of 0.3 ml/min; solution of 1 mM NaCl + 0.1 mM NaHCO3). Bacterial removal in pyrophyllite columns increased from 90 to 100% with decreasing flow rate from 0.6 to 0.15 ml/min due to increasing contact time between bacteria and filter materials. In addition, bacterial removal remained relatively constant at 94-97% even though NaHCO3 concentration increased from 0.1 to 10 mM (flow rate of 0.3 ml/min). This could be related to the fact that pyrophyllite remained positively-charged even though the solution conditions changed. This study demonstrates that pyrophyllite could be used as adsorptive filter materials in the removal of bacteria.


Assuntos
Silicatos de Alumínio/química , Aderência Bacteriana/fisiologia , Escherichia coli/isolamento & purificação , Escherichia coli/fisiologia , Ultrafiltração/métodos , Microbiologia da Água , Água/química , Adsorção , Argila , Purificação da Água/métodos
20.
Sci Rep ; 13(1): 5170, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36997526

RESUMO

Santa Barbara Amorphous-15 (SBA) is a stable and mesoporous silica material. Quaternized SBA-15 with alkyl chains (QSBA) exhibits electrostatic attraction for anionic molecules via the N+ moiety of the ammonium group, whereas its alkyl chain length determines its hydrophobic interactions. In this study, QSBA with different alkyl chain lengths were synthesized using the trimethyl, dimethyloctyl, and dimethyoctadecyl groups (C1QSBA, C8QSBA, and C18QSBA, respectively). Carbamazepine (CBZ) is a widely prescribed pharmaceutical compound, but is difficult to remove using conventional water treatments. The CBZ adsorption characteristics of QSBA were examined to determine its adsorption mechanism by changing the alkyl chain length and solution conditions (pH and ionic strength). A longer alkyl chain resulted in slower adsorption (up to 120 min), while the amount of CBZ adsorbed was higher for longer alkyl chains per unit mass of QSBA at equilibrium. The maximum adsorption capacities of C1QSBA, C8QSBA, and C18QSBA, were 3.14, 6.56, and 24.5 mg/g, respectively, as obtained using the Langmuir model. For the tested initial CBZ concentrations (2-100 mg/L), the adsorption capacity increased with increasing alkyl chain length. Because CBZ does not dissociate readily (pKa = 13.9), stable hydrophobic adsorption was observed despite the changes in pH (0.41-0.92, 1.70-2.24, and 7.56-9.10 mg/g for C1QSBA, C8QSBA, and C18QSBA, respectively); the exception was pH 2. Increasing the ionic strength from 0.1 to 100 mM enhanced the adsorption capacity of C18QSBA from 9.27 ± 0.42 to 14.94 ± 0.17 mg/g because the hydrophobic interactions were increased while the electrostatic attraction of the N+ was reduced. Thus, the ionic strength was a stronger control factor determining hydrophobic adsorption of CBZ than the solution pH. Based on the changes in hydrophobicity, which depends on the alkyl chain length, it was possible to enhance CBZ adsorption and investigate the adsorption mechanism in detail. Thus, this study aids the development of adsorbents suitable for pharmaceuticals with controlling molecular structure of QSBA and solution conditions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA