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1.
Small ; 20(15): e2307885, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38161253

RESUMO

For the development of acid-responsive advanced fluorescent films with a 2D nanostructure, a pyridyl cyanostilbene-based AIEgen (PCRM) is newly synthesized. The synthesized PCRM exhibits aggregation-induced emission (AIE) and responds reversibly to acid and base stimuli. To fabricate the nanoporous polymer-stabilized film, PCRM and 4-(octyloxy)benzoic acid (8OB) are complexed in a 1:1 ratio through hydrogen bonding. The PCRM-8OB complex with a smectic mesophase is uniaxially oriented at first and photopolymerized with a crosslinker. By subsequently removing 8OB in an alkaline solution, nanopores are generated in the self-assembled and polymerized hierarchical 2D nanostructure film. The prepared nanoporous fluorescent films exhibit not only the reversible response to acid and base stimuli but also mechanical and chemical robustness. Since the nanoporous fluorescent films have different sensitivities to trifluoroacetic acid (TFA) depending on the molecular orientation in the film, advanced acid vapor sensors that can display the risk level according to the concentration of TFA are demonstrated. Reactive AIEgens-based hierarchical nanostructure films with nanopores fabricated by a subsequent process of self-assembly, polymerization, and etching can open a new door for the development of advanced chemosensors.

2.
Proc Natl Acad Sci U S A ; 117(51): 32433-32442, 2020 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-33288688

RESUMO

Ferroptosis is an iron-dependent regulated necrosis mediated by lipid peroxidation. Cancer cells survive under metabolic stress conditions by altering lipid metabolism, which may alter their sensitivity to ferroptosis. However, the association between lipid metabolism and ferroptosis is not completely understood. In this study, we found that the expression of elongation of very long-chain fatty acid protein 5 (ELOVL5) and fatty acid desaturase 1 (FADS1) is up-regulated in mesenchymal-type gastric cancer cells (GCs), leading to ferroptosis sensitization. In contrast, these enzymes are silenced by DNA methylation in intestinal-type GCs, rendering cells resistant to ferroptosis. Lipid profiling and isotope tracing analyses revealed that intestinal-type GCs are unable to generate arachidonic acid (AA) and adrenic acid (AdA) from linoleic acid. AA supplementation of intestinal-type GCs restores their sensitivity to ferroptosis. Based on these data, the polyunsaturated fatty acid (PUFA) biosynthesis pathway plays an essential role in ferroptosis; thus, this pathway potentially represents a marker for predicting the efficacy of ferroptosis-mediated cancer therapy.


Assuntos
Ácidos Graxos Insaturados/biossíntese , Ferroptose/fisiologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Ácido Araquidônico/genética , Ácido Araquidônico/metabolismo , Ácido Araquidônico/farmacologia , Carbolinas/farmacologia , Linhagem Celular Tumoral , Metilação de DNA , Dessaturase de Ácido Graxo Delta-5 , Elementos Facilitadores Genéticos , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Elongases de Ácidos Graxos/genética , Elongases de Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/genética , Ácidos Graxos Insaturados/metabolismo , Ferroptose/efeitos dos fármacos , Ferroptose/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Metabolismo dos Lipídeos/genética , Regiões Promotoras Genéticas , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia
3.
Sens Actuators B Chem ; 3322021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33519092

RESUMO

MicroRNAs (miRNAs) are important post-transcriptional gene regulators and can serve as potential biomarkers for many diseases. Most of the current miRNA detection techniques require purification from biological samples, amplification, labeling, or tagging, which makes quantitative analysis of clinically relevant samples challenging. Here we present a new strategy for the detection of miRNAs with uniformity over a large area based on signal amplification using enzymatic reactions and measurements using time-of-flight secondary ion mass spectrometry (ToF-SIMS), a sensitive surface analysis tool. This technique has high sequence specificity through hybridization with a hairpin DNA probe and allows the identification of single-base mismatches that are difficult to distinguish by conventional mass spectrometry. We successfully detected target miRNAs in biological samples without purification, amplification, or labeling of target molecules. In addition, by adopting a well-known chromogenic enzymatic reaction from the field of biotechnology, we extended the use of enzyme-amplified signal enhancement ToF (EASE-ToF) to protein detection. Our strategy has advantages with respect to scope, quantification, and throughput over the currently available methods, and is amenable to multiplexing based on the outstanding molecular specificity of mass spectrometry (MS). Therefore, our technique not only has the potential for use in clinical diagnosis, but also provides evidence that MS can serve as a useful readout for biosensing to perform multiplexed analysis extending beyond the limitations of existing technology.

4.
Chin J Cancer Res ; 33(5): 583-591, 2021 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-34815632

RESUMO

OBJECTIVE: Benefits of adjuvant treatment in pT1N1 gastric cancer (GC) remain controversial. Additionally, an effective biomarker for early GC is the need of the hour. The prognostic and predictive roles of single patient classifier (SPC) were validated in stage II/III GC. In this study, we aimed to elucidate the role of SPC as a biomarker for pT1N1 GC. METHODS: The present retrospective biomarker study (NCT03485105) enrolled patients treated for pT1N1 GC between 1996 and 2012 from two large hospitals (the Y cohort and S cohort). For SPC, mRNA expression of four classifier genes (GZMB, WARS, SFRP4 and CDX1) were evaluated by real-time reverse transcription-polymerase chain reaction assay. The SPC was revised targeting pT1 stages and the prognosis was stratified as high- and low-risk group by the expression of SFRP4, a representative epithelial-mesenchymal transition marker. RESULTS: SPC was evaluated in 875 patients (n=391 and 484 in the Y and S cohorts, respectively). Among 864 patients whose SPC result was available, 41 (4.7%) patients experience GC recurrence. According to revised SPC, 254 (29.4%) patients were classified as high risk [123 (31.5%) and 131 (27.1%) in the Y and S cohorts, respectively]. The high risk was related to frequent recurrence in both Y and S cohort (log-rank P=0.023, P<0.001, respectively), while there was no difference byGZMB and WARS expression. Multivariable analyses of the overall-cohort confirmed the high risk of revised SPC as a significant prognostic factor [hazard ratio (HR): 4.402 (2.293-8.449), P<0.001] of GC. A significant difference was not detected by SPC in the prognosis of patients in the presence and absence of adjuvant treatment (log-rank P=0.670). CONCLUSIONS: The present study revealed the revised SPC as a prognostic biomarker of pT1N1 GC and suggested the use of the revised SPC for early-stage GC as like stage II/III.

5.
Lancet Oncol ; 19(5): 629-638, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29567071

RESUMO

BACKGROUND: Adjuvant chemotherapy after surgery improves survival of patients with stage II-III, resectable gastric cancer. However, the overall survival benefit observed after adjuvant chemotherapy is moderate, suggesting that not all patients with resectable gastric cancer treated with adjuvant chemotherapy benefit from it. We aimed to develop and validate a predictive test for adjuvant chemotherapy response in patients with resectable, stage II-III gastric cancer. METHODS: In this multi-cohort, retrospective study, we developed through a multi-step strategy a predictive test consisting of two rule-based classifier algorithms with predictive value for adjuvant chemotherapy response and prognosis. Exploratory bioinformatics analyses identified biologically relevant candidate genes in gastric cancer transcriptome datasets. In the discovery analysis, a four-gene, real-time RT-PCR assay was developed and analytically validated in formalin-fixed, paraffin-embedded (FFPE) tumour tissues from an internal cohort of 307 patients with stage II-III gastric cancer treated at the Yonsei Cancer Center with D2 gastrectomy plus adjuvant fluorouracil-based chemotherapy (n=193) or surgery alone (n=114). The same internal cohort was used to evaluate the prognostic and chemotherapy response predictive value of the single patient classifier genes using associations with 5-year overall survival. The results were validated with a subset (n=625) of FFPE tumour samples from an independent cohort of patients treated in the CLASSIC trial (NCT00411229), who received D2 gastrectomy plus capecitabine and oxaliplatin chemotherapy (n=323) or surgery alone (n=302). The primary endpoint was 5-year overall survival. FINDINGS: We identified four classifier genes related to relevant gastric cancer features (GZMB, WARS, SFRP4, and CDX1) that formed the single patient classifier assay. In the validation cohort, the prognostic single patient classifier (based on the expression of GZMB, WARS, and SFRP4) identified 79 (13%) of 625 patients as low risk, 296 (47%) as intermediate risk, and 250 (40%) as high risk, and 5-year overall survival for these groups was 83·2% (95% CI 75·2-92·0), 74·8% (69·9-80·1), and 66·0% (60·1-72·4), respectively (p=0·012). The predictive single patient classifier (based on the expression of GZMB, WARS, and CDX1) assigned 281 (45%) of 625 patients in the validation cohort to the chemotherapy-benefit group and 344 (55%) to the no-benefit group. In the predicted chemotherapy-benefit group, 5-year overall survival was significantly improved in those patients who had received adjuvant chemotherapy after surgery compared with those who received surgery only (80% [95% CI 73·5-87·1] vs 64·5% [56·8-73·3]; univariate hazard ratio 0·47 [95% CI 0·30-0·75], p=0·0015), whereas no such improvement in 5-year overall survival was observed in the no-benefit group (72·9% [66·5-79·9] in patients who received chemotherapy plus surgery vs 72·5% [65·8-79·9] in patients who only had surgery; 0·93 [0·62-1·38], p=0·71). The predictive single patient classifier groups (chemotherapy benefit vs no-benefit) could predict adjuvant chemotherapy benefit in terms of 5-year overall survival in the validation cohort (pinteraction=0·036 in univariate analysis). Similar results were obtained in the internal evaluation cohort. INTERPRETATION: The single patient classifiers validated in this study provide clinically important prognostic information independent of standard risk-stratification methods and predicted chemotherapy response after surgery in two independent cohorts of patients with resectable, stage II-III gastric cancer. The single patient classifiers could complement TNM staging to optimise decision making in patients with resectable gastric cancer who are eligible for adjuvant chemotherapy after surgery. Further validation of these results in prospective studies is warranted. FUNDING: Ministry of ICT and Future Planning; Ministry of Trade, Industry, and Energy; and Ministry of Health and Welfare.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Biomarcadores Tumorais/genética , Sistemas de Apoio a Decisões Clínicas , Técnicas de Apoio para a Decisão , Gastrectomia , Medicina de Precisão , Neoplasias Gástricas/terapia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimioterapia Adjuvante , Tomada de Decisão Clínica , Biologia Computacional , Feminino , Gastrectomia/efeitos adversos , Perfilação da Expressão Gênica , Granzimas/genética , Proteínas de Homeodomínio/genética , Humanos , Masculino , Estadiamento de Neoplasias , Seleção de Pacientes , Valor Preditivo dos Testes , Proteínas Proto-Oncogênicas/genética , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Fatores de Tempo , Transcriptoma , Resultado do Tratamento , Triptofano-tRNA Ligase/genética
6.
Anal Chem ; 88(2): 1078-82, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26717968

RESUMO

A novel method (i.e., continuous magnetic cell separation in a microfluidic channel) is demonstrated to be capable of inducing multifractionation of mixed cell suspensions into multiple outlet fractions. Here, multicomponent cell separation is performed with three different distinguishable magnetic nanoclusters (MnFe2O4, Fe3O4, and CoFe2O4), which are tagged on A431 cells. Because of their mass magnetizations, which can be ideally altered by doping with magnetic atom compositions (Mn, Fe, and Co), the trajectories of cells with each magnetic nanocluster in a flow are shown to be distinct when dragged under the same external magnetic field; the rest of the magnetic characteristics of the nanoclusters are identically fixed. This proof of concept study, which utilizes the magnetization-controlled nanoclusters (NCs), suggests that precise and effective multifractionation is achievable with high-throughput and systematic accuracy for dynamic cell separation.


Assuntos
Separação Celular/instrumentação , Separação Celular/métodos , Nanopartículas de Magnetita/química , Técnicas Analíticas Microfluídicas , Elementos de Transição/química , Linhagem Celular Tumoral , Humanos , Fenômenos Magnéticos , Técnicas Analíticas Microfluídicas/instrumentação , Tamanho da Partícula , Propriedades de Superfície
7.
Analyst ; 140(10): 3375-83, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25837891

RESUMO

We developed a novel protein-based bioassay platform utilizing metal-enhanced fluorescence (MEF), which is a hydrogel microarray entrapping silica-coated silver nanoparticles (Ag@SiO2). As a model system, different concentrations of glucose were detected using a fluorescence method by sequential bienzymatic reaction of hydrogel-entrapped glucose oxidase (GOX) and peroxidase (POD) inside a hydrogel microarray. Microarrays based on poly(ethylene glycol)(PEG) hydrogels were prepared by photopatterning a solution containing PEG diacrylate (PEG-DA), photoinitiator, enzymes, and Ag@SiO2. The resulting hydrogel microarrays were able to entrap both enzymes and Ag@SiO2 without leaching and deactivation problems. The presence of Ag@SiO2 within the hydrogel microarray enhanced the fluorescence signal, and the extent of the enhancement was dependent on the thickness of silica shells and the amount of Ag@SiO2. Optimal MEF effects were achieved when the thickness of the silica shell was 17.5 nm, and 0.5 mg mL(-1) of Ag@SiO2 was incorporated into the assay systems. Compared with the standard hydrogel microarray-based assay performed without Ag@SiO2, more than a 4-fold fluorescence enhancement was observed in a glucose concentration range between 10(-3) mM and 10.0 mM using hydrogel microarray entrapping Ag@SiO2, which led to significant improvements in the sensitivity and the limit of detection (LOD). The hydrogel microarray system presented in this study could be successfully combined with a microfluidic device as an initial step to create an MEF-based micro-total-analysis-system (µ-TAS).


Assuntos
Técnicas Biossensoriais/métodos , Glucose Oxidase/metabolismo , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Análise em Microsséries/métodos , Dióxido de Silício/química , Prata/química , Aspergillus niger/enzimologia , Técnicas Biossensoriais/instrumentação , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Glucose/análise , Glucose Oxidase/química , Dispositivos Lab-On-A-Chip , Análise em Microsséries/instrumentação , Polietilenoglicóis/química , Espectrometria de Fluorescência
8.
Nanotechnology ; 25(24): 245103, 2014 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-24872113

RESUMO

We developed Pyrene-Gadolinium (Py-Gd) nanoparticles as pH-sensitive magnetic resonance imaging (MRI) contrast agents capable of showing a high-Mr signal in cancer-specific environments, such as acidic conditions. Py-Gd nanoparticles were prepared by coating Py-Gd, which is a complex of gadolinium with pyrenyl molecules, with pyrenyl polyethyleneglycol PEG using a nano-emulsion method. These particles show better longitudinal relaxation time (T1) MR signals in acidic conditions than they do in neutral conditions. Furthermore, the particles exhibit biocompatibility and MR contrast effects in both in vitro and in vivo studies. From these results, we confirm that Py-Gd nanoparticles have the potential to be applied for accurate cancer diagnosis and therapy.


Assuntos
Meios de Contraste/síntese química , Gadolínio , Imageamento por Ressonância Magnética/instrumentação , Nanopartículas Metálicas , Neoplasias/diagnóstico , Animais , Células 3T3 BALB , Linhagem Celular Tumoral , Materiais Revestidos Biocompatíveis , Gadolínio/química , Humanos , Imageamento por Ressonância Magnética/métodos , Nanopartículas Metálicas/química , Camundongos , Polietilenoglicóis/química , Pirenos/química
9.
Anal Chim Acta ; 1292: 342233, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38309850

RESUMO

BACKGROUND: Label-free surface-enhanced Raman spectroscopy (SERS)-based metabolic profiling has great potential for early cancer diagnosis, but further advancements in analytical methods and clinical evidence studies are required for clinical applications. To improve the cancer diagnostic accuracy of label-free SERS spectral analysis of complex biological fluids, it is necessary to obtain specifically enhanced SERS signals of cancer-related metabolites present at low concentrations. RESULTS: This study presents a novel 3D SERS sensor, comprising a surface-carbonized silver nanowire (AgNW)-stacked filter membrane, alongside an optimized urine/methanol/chloroform extraction technique, which specifically changes the molecular adsorption and orientation of aromatic metabolites onto SERS substrates. By analyzing the pretreated urine samples on the surface-carbonized AgNW 3D SERS sensor, distinct and highly enhanced SERS peaks derived from semi-polar aromatic metabolites were observed for pancreatic cancer and prostate cancer samples compared with normal controls. Urine metabolite analysis using SERS fingerprinting successfully differentiated pancreatic cancer and prostate cancer groups from normal control group: normal control (n = 56), pancreatic cancer (n = 40), and prostate cancer (n = 39). SIGNIFICANCE AND NOVELTY: We confirmed the clinical feasibility of performing fingerprint analysis of urinary metabolites based on the surface-carbonized AgNW 3D SERS sensor and methanol/chloroform extraction for noninvasive cancer screening. This technology holds potential for large-scale screening owing to its high accuracy, and cost effective, simple and rapid detection method.


Assuntos
Nanopartículas Metálicas , Nanofios , Neoplasias Pancreáticas , Neoplasias da Próstata , Masculino , Humanos , Análise Espectral Raman/métodos , Detecção Precoce de Câncer , Prata/química , Clorofórmio , Metanol , Nanopartículas Metálicas/química
10.
Adv Mater ; 35(1): e2206764, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36314392

RESUMO

Light manipulation strategies of nature have fascinated humans for centuries. In particular, structural colors are of considerable interest due to their ability to control the interaction between light and matter. Here, wrinkled photonic crystal papers (PCPs) are fabricated to demonstrate the consistent reflection of colors regardless of viewing angles. The nanoscale molecular self-assembly of a cholesteric liquid crystal (CLC) with a microscale corrugated surface is combined. Fully polymerizable CLC paints are uniaxially coated onto a wrinkled interpenetrating polymer network (IPN) substrate. Photopolymerization of the helicoidal nanostructures results in a flexible and free-standing PCP. The facile method of fabricating the wrinkled PCPs provides a scalable route for the development of novel chirophotonic materials with precisely controlled helical pitch and curvature dimensions. The reflection notch position of the flat PCP shifts to a lower wavelength when the viewing angle increased, while the selective reflection wavelength of wrinkled PCP is remained consistent regardless of viewing angles. The optical reflection of the 1D stripe-wrinkled PCP is dependent on the wrinkle direction. PCPs with different corrugated directions can be patterned to reduce the angular-dependent optical reflection of wrinkles. Furthermore, 2D wavy-wrinkled PCP is successfully developed that exhibit directionally independent reflection of color.

11.
Sci Rep ; 13(1): 20784, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38012171

RESUMO

During the continuous charge and discharge process in lithium-sulfur batteries, one of the next-generation batteries, polysulfides are generated in the battery's electrolyte, and impact its performance in terms of power and capacity by involving the process. The amount of polysulfides in the electrolyte could be estimated by the change of the Gibbs free energy of the electrolyte, [Formula: see text] in the presence of polysulfide. However, obtaining [Formula: see text] of the diverse mixtures of components in the electrolyte is a complex and expensive task that shows itself as a bottleneck in optimization of electrolytes. In this work, we present a machine-learning approach for predicting [Formula: see text] of electrolytes. The proposed architecture utilizes (1) an attention-based model (Attentive FP), a contrastive learning model (MolCLR) or morgan fingerprints to represent chemical components, and (2) transformers to account for the interactions between chemicals in the electrolyte. This architecture was not only capable of predicting electrolyte properties, including those of chemicals not used during training, but also providing insights into chemical interactions within electrolytes. It revealed that interactions with other chemicals relate to the logP and molecular weight of the chemicals.

12.
Exp Mol Med ; 55(5): 974-986, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37121972

RESUMO

The mesenchymal cancer phenotype is known to be clinically related to treatment resistance and a poor prognosis. We identified gene signature-based molecular subtypes of gastric cancer (GC, n = 547) based on transcriptome data and validated their prognostic and predictive utility in multiple external cohorts. We subsequently examined their associations with tumor microenvironment (TME) features by employing cellular deconvolution methods and sequencing isolated GC populations. We further performed spatial transcriptomics analysis and immunohistochemistry, demonstrating the presence of GC cells in a partial epithelial-mesenchymal transition state. We performed network and pharmacogenomic database analyses to identify TGF-ß signaling as a driver pathway and, thus, a therapeutic target. We further validated its expression in tumor cells in preclinical models and a single-cell dataset. Finally, we demonstrated that inhibition of TGF-ß signaling negated mesenchymal/stem-like behavior and therapy resistance in GC cell lines and mouse xenograft models. In summary, we show that the mesenchymal GC phenotype could be driven by epithelial cancer cell-intrinsic TGF-ß signaling and propose therapeutic strategies based on targeting the tumor-intrinsic mesenchymal reprogramming of medically intractable GC.


Assuntos
Neoplasias Gástricas , Animais , Camundongos , Humanos , Neoplasias Gástricas/patologia , Transição Epitelial-Mesenquimal/genética , Perfilação da Expressão Gênica , Transcriptoma , Modelos Animais de Doenças , Fator de Crescimento Transformador beta/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Microambiente Tumoral/genética
13.
Nat Commun ; 14(1): 5728, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37714840

RESUMO

Arachidonic and adrenic acids in the membrane play key roles in ferroptosis. Here, we reveal that lipoprotein-associated phospholipase A2 (Lp-PLA2) controls intracellular phospholipid metabolism and contributes to ferroptosis resistance. A metabolic drug screen reveals that darapladib, an inhibitor of Lp-PLA2, synergistically induces ferroptosis in the presence of GPX4 inhibitors. We show that darapladib is able to enhance ferroptosis under lipoprotein-deficient or serum-free conditions. Furthermore, we find that Lp-PLA2 is located in the membrane and cytoplasm and suppresses ferroptosis, suggesting a critical role for intracellular Lp-PLA2. Lipidomic analyses show that darapladib treatment or deletion of PLA2G7, which encodes Lp-PLA2, generally enriches phosphatidylethanolamine species and reduces lysophosphatidylethanolamine species. Moreover, combination treatment of darapladib with the GPX4 inhibitor PACMA31 efficiently inhibits tumour growth in a xenograft model. Our study suggests that inhibition of Lp-PLA2 is a potential therapeutic strategy to enhance ferroptosis in cancer treatment.


Assuntos
Ferroptose , Neoplasias , Humanos , 1-Alquil-2-acetilglicerofosfocolina Esterase/antagonistas & inibidores , Metabolismo dos Lipídeos/efeitos dos fármacos , Neoplasias/tratamento farmacológico
14.
Nanoscale Res Lett ; 17(1): 42, 2022 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-35366682

RESUMO

Triboelectric nanogenerator (TENG) uses charge transfer between two asymmetric charge affinity materials such as metal and dielectrics. Metal electrode acts as charge collector from dielectrics and acts as charge transfer path to an external load, which model deals with only a net charge of metal electrode concerning electrical output. In this work, we found that metal electrode in triboelectric generator has non-negligible surface charge polarization causing open-circuit voltage difference in the model TENG system. The output voltage depends on the initial preparation conditions of the TENG for I-V measurements, even for the same measured charge densities. The measured output voltage difference with the same charge density implies that electric charges of TENG are composed of movable charges that affect current and voltage output and the bounded fixed charges that only affect open-circuit voltage.

15.
ACS Appl Mater Interfaces ; 14(17): 19353-19364, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35446031

RESUMO

Lithium-sulfur batteries (LSBs) have been considered promising candidates for application in high-density energy storage systems owing to their high gravimetric and volumetric energy densities. However, LSB technology faces many barriers from the intrinsic properties of active materials that need to be solved to realize high-performance LSBs. Herein, an aqueous binder, that is, PPCP, based on polyethyleneimine (PEI), polyvinylpyrrolidone (PVP), citric acid (CA), and polyethylene oxide (PEO), was developed. The synthesized PPCP binder has incredible mechanical properties, suitable viscosity, and essential functional groups for developing an effective and reliable LSB system. This study demonstrates that CA is crucial in cross-linking PEI-PVP polymer molecules, and PEO segments significantly enhance the flexibility of the PPCP binder; thus, the binder can mechanically stabilize the cathode structure over many operating cycles. The redistribution of active materials during the charge-discharge processes and reduction of the shuttle effect originate from the excellent chemical interactions of PPCP with lithium polysulfides, which is confirmed by the density functional theory calculation, enabling an ultra-long electrochemical cycle life of 1800 cycles with a low decay rate of 0.0278% cycle-1.

16.
J Clin Med ; 11(11)2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35683460

RESUMO

Extragastric recurrence of early gastric cancer (EGC) after curative resection is rare, but prognosis has been poor in previous reports. Recently, single patient classifier (SPC) genes, such as secreted frizzled-related protein 4 (SFRP4) and caudal-type homeobox 1 (CDX1), were associated with prognosis and chemotherapy response in stage II-III gastric cancer. The aim of our study is, therefore, to elucidate predictive factors for extragastric recurrence of EGC after curative resection, including with the expression of SPC genes. We retrospectively reviewed electronic medical records of 1974 patients who underwent endoscopic or surgical curative resection for EGC. We analyzed clinicopathological characteristics to determine predictive factors for extragastric recurrence. Total RNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tumor tissue and amplified by real-time reverse transcription polymerase chain reaction to evaluate expression of SPC genes. Overall incidences of extragastric recurrence were 0.9%. In multivariate analysis, submucosal invasion (odds ratio [OR] = 6.351, p = 0.032) and N3 staging (OR = 171.512, p = 0.012) were independent predictive factors for extragastric recurrence. Mean expression of SFRP4 in extragastric recurrence (-2.8 ± 1.3) was significantly higher than in the control group (-4.3 ± 1.6) (p = 0.047). Moreover, mean expression of CDX1 in extragastric recurrence (-4.6 ± 2.0) was significantly lower than in the control group (-2.4 ± 1.8) (p = 0.025). Submucosal invasion and metastasis of more than seven lymph nodes were independent predictive factors for extragastric recurrence. In addition, SFRP4 and CDX1 may be novel predictive markers for extragastric recurrence of EGC after curative resection.

17.
Analyst ; 135(11): 2871-8, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20852777

RESUMO

This paper describes the use of microarray-based biosensor system for the determination of phenol. Microarrays based on poly(ethylene glycol)(PEG) hydrogel were prepared by photopatterning of a solution containing PEG diacrylate (PEG-DA), photoinitiator, tyrosinase, and CdSe/ZnS quantum dots (QDs). During photo-induced crosslinking, tyrosinase and QDs were entrapped within the hydrogel microarrays, making the hydrogel microarray fluorescent and responsive to phenol. The entrapped tyrosinase could carry out enzyme-catalyzed oxidation of phenol to produce quinones, which subsequently quenched the fluorescence of QDs within hydrogel microarray. The fluorescence intensity of the hydrogel microarrays decreased linearly according to phenol concentration and the detection limit of this system was found to be 1.0 µM. The microarray system presented in this study could be combined with a microfluidic device as an initial step to create a phenol-detecting "micro-total-analysis-system (µ-TAS)".


Assuntos
Técnicas Biossensoriais , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Técnicas Analíticas Microfluídicas , Monofenol Mono-Oxigenase/química , Fenol/análise , Pontos Quânticos , Fluorescência , Monofenol Mono-Oxigenase/metabolismo , Oxirredução , Polietilenoglicóis/química , Quinonas/síntese química , Quinonas/química
18.
ACS Appl Bio Mater ; 2(5): 2219-2228, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35030660

RESUMO

MicroRNA (miR), a key molecule involved in endogenous RNA interference, is a promising therapeutic agent. In vivo delivery of miR, however, is a major factor limiting its application because its polyanionic nature and vulnerability to breakdown make delivery of miR to targeted lesions difficult. To overcome these challenges, we developed a self-assembled miR delivery system consisting of cholesterol-conjugated miR and polyethylene glycol-grafted polyethylene imine. Nanosized complexes of miR with polyethylene imine, which protected miR and its delivery into targeted lesions in vivo, were successfully synthesized by polyethylene glycol grafting. The hydrophobicity of cholesterol improved the structural stability of the complex, preventing the loss of miR. Here, we report the preparation of this self-assembled complex. We examined the delivery efficiency and validated the therapeutic efficacy of the complex. In conclusion, our miR delivery system shows considerable potential for effective in vivo delivery of miR.

19.
Yonsei Med J ; 60(2): 132-139, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30666834

RESUMO

PURPOSE: Clinical implications of single patient classifier (SPC) and microsatellite instability (MSI) in stage II/III gastric cancer have been reported. We investigated SPC and the status of MSI and Epstein-Barr virus (EBV) as combinatory biomarkers to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer. MATERIALS AND METHODS: Tumor specimens and clinical information were collected from patients enrolled in CLASSIC trial, a randomized controlled study of capecitabine plus oxaliplatin-based adjuvant chemotherapy. The results of nine-gene based SPC assay were classified as prognostication (SPC-prognosis) and prediction of chemotherapy benefit (SPC-prediction). Five quasimonomorphic mononucleotide markers were used to assess tumor MSI status. EBV-encoded small RNA in situ hybridization was performed to define EBV status. RESULTS: There were positive associations among SPC, MSI, and EBV statuses among 586 patients. In multivariate analysis of disease-free survival, SPC-prognosis [hazard ratio (HR): 1.879 (1.101-3.205), 2.399 (1.415-4.067), p=0.003] and MSI status (HR: 0.363, 95% confidence interval: 0.161-0.820, p=0.015) were independent prognostic factors along with age, Lauren classification, TNM stage, and chemotherapy. Patient survival of SPC-prognosis was well stratified regardless of EBV status and in microsatellite stable (MSS) group, but not in MSI-high group. Significant survival benefit from adjuvant chemotherapy was observed by SPC-Prediction in MSS and EBV-negative gastric cancer. CONCLUSION: SPC, MSI, and EBV statuses could be used in combination to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer.


Assuntos
Herpesvirus Humano 4/fisiologia , Instabilidade de Microssatélites , Neoplasias Gástricas/genética , Neoplasias Gástricas/virologia , Biomarcadores Tumorais/metabolismo , Quimioterapia Adjuvante , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Neoplasias Gástricas/patologia , Resultado do Tratamento
20.
J Gastric Cancer ; 18(2): 142-151, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29984064

RESUMO

PURPOSE: The modification of the cancer classification system aimed to improve the classical anatomy-based tumor, node, metastasis (TNM) staging by considering tumor biology, which is associated with patient prognosis, because such information provides additional precision and flexibility. MATERIALS AND METHODS: We previously developed an mRNA expression-based single patient classifier (SPC) algorithm that could predict the prognosis of patients with stage II/III gastric cancer. We also validated its utilization in clinical settings. The prognostic single patient classifier (pSPC) differentiates based on 3 prognostic groups (low-, intermediate-, and high-risk), and these groups were considered as independent prognostic factors along with TNM stages. We evaluated whether the modified TNM staging system based on the pSPC has a better prognostic performance than the TNM 8th edition staging system. The data of 652 patients who underwent gastrectomy with curative intent for gastric cancer between 2000 and 2004 were evaluated. Furthermore, 2 other cohorts (n=307 and 625) from a previous study were assessed. Thus, 1,584 patients were included in the analysis. To modify the TNM staging system, one-grade down-staging was applied to low-risk patients according to the pSPC in the TNM 8th edition staging system; for intermediate- and high-risk groups, the modified TNM and TNM 8th edition staging systems were identical. RESULTS: Among the 1,584 patients, 187 (11.8%), 664 (41.9%), and 733 (46.3%) were classified into the low-, intermediate-, and high-risk groups, respectively, according to the pSPC. pSPC prognoses and survival curves of the overall population were well stratified, and the TNM stage-adjusted hazard ratios of the intermediate- and high-risk groups were 1.96 (95% confidence interval [CI], 1.41-2.72; P<0.001) and 2.54 (95% CI, 1.84-3.50; P<0.001), respectively. Using Harrell's C-index, the prognostic performance of the modified TNM system was evaluated, and the results showed that its prognostic performance was better than that of the TNM 8th edition staging system in terms of overall survival (0.635 vs. 0.620, P<0.001). CONCLUSIONS: The pSPC-modified TNM staging is an alternative staging system for stage II/III gastric cancer.

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