Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Adv ; 9(16): eadf4049, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37083532

RESUMO

An integrated textile electronic system is reported here, enabling a truly free form factor system via textile manufacturing integration of fiber-based electronic components. Intelligent and smart systems require freedom of form factor, unrestricted design, and unlimited scale. Initial attempts to develop conductive fibers and textile electronics failed to achieve reliable integration and performance required for industrial-scale manufacturing of technical textiles by standard weaving technologies. Here, we present a textile electronic system with functional one-dimensional devices, including fiber photodetectors (as an input device), fiber supercapacitors (as an energy storage device), fiber field-effect transistors (as an electronic driving device), and fiber quantum dot light-emitting diodes (as an output device). As a proof of concept applicable to smart homes, a textile electronic system composed of multiple functional fiber components is demonstrated, enabling luminance modulation and letter indication depending on sunlight intensity.

2.
Nanoscale Horiz ; 8(4): 522-529, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-36790218

RESUMO

InP quantum dots (QDs) are attracting significant interest as a potentially less toxic alternative to Cd-based QDs in many research areas. Although InP-based core/shell QDs with excellent photoluminescence properties have been reported so far, sophisticated interface treatment to eliminate defects is often necessary. Herein, using aminophosphine as a seeding source of phosphorus, we find that H2S can be efficiently generated from the reaction between a thiol and an alkylamine at high temperatures. Apart from general comprehension that H2S acts as a S precursor, it is revealed that with core etching by H2S, the interface between InP and ZnS can be reconstructed with S2- incorporation. Such a transition layer can reduce inherent defects at the interface, resulting in significant photoluminescence (PL) enhancement. Meanwhile, the size of the InP core could be further controlled by H2S etching, which offers a feasible process to obtain wide band gap InP-based QDs with blue emission.

3.
Nat Commun ; 13(1): 4189, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35922408

RESUMO

We propose a computational design framework to design the architecture of a white lighting system having multiple pixelated patterns of electric-field-driven quantum dot light-emitting diodes. The quantum dot of the white lighting system has been optimised by a system-level combinatorial colour optimisation process with the Nelder-Mead algorithm used for machine learning. The layout of quantum dot patterns is designed precisely using rigorous device-level charge transport simulation with an electric-field dependent charge injection model. A theoretical maximum of 97% colour rendering index has been achieved with red, green, cyan, and blue quantum dot light-emitting diodes as primary colours. The white lighting system has been fabricated using the transfer printing technique to validate the computational design framework. It exhibits excellent lighting performance of 92% colour rendering index and wide colour temperature variation from 1612 K to 8903 K with only the four pixelated quantum dots as primary.

4.
Biotechnol Lett ; 37(10): 2019-25, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26063621

RESUMO

OBJECTIVES: To develop a sensitive and quantitative method for monitoring the abnormal glycosylation of clinical and biopharmaceutical products. RESULTS: MALDI-MS-based quantitative targeted glycomics (MALDI-QTaG) was proposed for sensitive and quantitative analysis of total N-glycans. The derivatization reactions (i.e., amidation of sialic acid and incorporation of a positive charge moiety into the reducing end) dramatically increased the linearity (R(2) > 0.99) and sensitivity (limit of detection is 0.5 pmol/glycoprotein) relative to underivatized glycans. In addition, the analytical strategy was chromatographic purification-free and non-laborious process accessible to the high-throughput analyses. We used MALDI-QTaG to analyze the N-glycans of α-fetoprotein (AFP) purified from normal cord blood and HCC cell line (Huh7 cells). The total percentages of core-fucosylated AFP N-glycans from Huh7 cells and normal cord blood were 98 and 18%, respectively. CONCLUSIONS: This MALDI-MS-based glycomics technology has wide applications in many clinical and bioengineering fields requiring sensitive, quantitative and fast N-glycosylation validation.


Assuntos
Glicômica/métodos , Glicoproteínas/química , Polissacarídeos/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Linhagem Celular , Sangue Fetal , Hepatócitos , Ensaios de Triagem em Larga Escala/métodos , Humanos , Sensibilidade e Especificidade , alfa-Fetoproteínas/química
5.
Carbohydr Res ; 413: 5-11, 2015 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-26057990

RESUMO

The aberrant glycosylation profile on the surface of cancer cells has been recognized for its potential diagnostic value towards assessing tumor progression. In this study, we initially investigate N-glycan profiles on the surface of normal (HPDE) and cancerous (Capan-1, Panc-1, and MIA PaCa-2) pancreatic cell lines, which are from different sites of pancreatic tumor. The enzymatically deglycosylated total N-glycans are permethylated via a quantitative solid-phase method and then analyzed by using MALDI-TOF MS and MALDI-QIT-TOF MS. We demonstrate that the level of high-mannose type glycans is higher among Capan-1 cells-pancreatic cancer cells that have metastasized to the liver-than that observed among Panc-1 and MIA PaCa-2 cells-pancreatic cancer cells from the pancreas duct head and tail regions, respectively. Furthermore, the relative abundance of highly-branched sialyted N-glycans is significantly up-regulated on Panc-1 and MIA PaCa-2 pancreatic cancer cells compared to that of normal HPDE pancreas cells. Taken together, these results indicate that specific N-glycosylation profile changes in pancreatic cancer cells can be used to not only distinguish between normal and cancerous cells but also provide more information on their location and metastatic potential.


Assuntos
Glicômica , Nitrogênio/química , Neoplasias Pancreáticas/patologia , Polissacarídeos/química , Biomarcadores Tumorais/química , Linhagem Celular Tumoral , Glicoconjugados/química , Humanos , Espectrometria de Massas , Metástase Neoplásica
6.
Biotechnol Prog ; 31(3): 840-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25832445

RESUMO

Mass spectrometry (MS) analysis combined with stable isotopic labeling is a promising method for the relative quantification of aberrant glycosylation in diseases and disorders. We developed a stable isotopic labeling-based quantitative targeted glycomics (i-QTaG) technique for the comparative and quantitative analysis of total N-glycans using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We established the analytical procedure with the chemical derivatizations (i.e., sialic acid neutralization and stable isotopic labeling) of N-glycans using a model glycoprotein (bovine fetuin). Moreover, the i-QTaG using MALDI-TOF MS was evaluated with various molar ratios (1:1, 1:2, 1:5) of (13) C6 /(12) C6 -2-aminobenzoic acid-labeled glycans from normal human serum. Finally, this method was applied to direct comparison of the total N-glycan profiles between normal human sera (n = 8) and prostate cancer patient sera (n = 17). The intensities of the N-glycan peaks from i-QTaG method showed a good linearity (R(2) > 0.99) with the amount of the bovine fetuin glycoproteins. The ratios of relative intensity between the isotopically 2-AA labeled N-glycans were close to the theoretical molar ratios (1:1, 1:2, 1:5). We also demonstrated that the up-regulation of the Lewis antigen (~82%) in sera from prostate cancer patients. In this proof-of-concept study, we demonstrated that the i-QTaG method, which enables to achieve a reliable comparative quantitation of total N-glycans via MALDI-TOF MS analysis, has the potential to diagnose and monitor alterations in glycosylation associated with disease states or biotherapeutics.


Assuntos
Glicômica/métodos , Marcação por Isótopo , Polissacarídeos/sangue , Animais , Estudos de Casos e Controles , Bovinos , Estudos de Avaliação como Assunto , Fetuínas/química , Glicosilação , Humanos , Masculino , Ácido N-Acetilneuramínico , Neoplasias da Próstata/sangue , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Regulação para Cima , ortoaminobenzoatos/química
7.
Anal Chem ; 87(2): 858-63, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25525717

RESUMO

N-Acyl homoserine lactones (AHLs), quorum sensing molecules produced by Gram-negative bacteria, are used as important secondary metabolites for antibacterial drug development and cell-to-cell communication. Although various analytical techniques have been developed for detection and quantitation of AHLs from more complex bacterial culture media, only a few methods have been applied to AHL identification in physiological samples. Here, we developed a highly sensitive and reliable MALDI-based 3-oxo AHL quantitation method by employing Girard's reagent T (GT) to produce a permanent cationic charge state [M](+) at the ketone group of AHLs. After extracting AHLs from the supernatant of bacterial cultures using ethyl acetate, the extracts were subsequently derivatized with GT without any additional purification or desalting steps. The chemical derivatization of 3-oxo AHLs dramatically enhanced sensitivity (up to 60 000 times) by lowering the limit of detection (LOD, ∼0.5 fmol)/limit of quantitation (LOQ, ∼2.5 fmol). Additionally, the GT-derivatized 3-oxo AHLs allowed more accurate quantitative analysis from the Pseudomonas aeruginosa PAO1 culture supernatants. This method may be applied for developing high-throughput and sensitive detection methods of quorum sensing signal molecules in biofilm-related clinical applications such as virulence factor characterization and antibacterial drug development.


Assuntos
4-Butirolactona/análogos & derivados , Cetonas/química , Pseudomonas aeruginosa/metabolismo , Percepção de Quorum , Virulência , 4-Butirolactona/análise , Biofilmes , Cromatografia Líquida , Humanos , Pseudomonas aeruginosa/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
8.
Mol Cells ; 38(1): 65-74, 2015 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-25518929

RESUMO

Carbohydrate antigens expressed on pig cells are considered to be major barriers in pig-to-human xenotransplantation. Even after α1,3-galactosyltransferase gene knock-out (GalT-KO) pigs are generated, potential non-Gal antigens are still existed. However, to the best of our knowledge there is no extensive study analyzing N-glycans expressed on the GalT-KO pig tissues or cells. Here, we identified and quantified totally 47 N-glycans from wild-type (WT) and GalT-KO pig fibroblasts using mass spectrometry. First, our results confirmed the absence of galactose-alpha-1,3-galactose (α-Gal) residue in the GalT-KO pig cells. Interestingly, we showed that the level of overall fucosylated N-glycans from GalT-KO pig fibroblasts is much higher than from WT pig fibroblasts. Moreover, the relative quantity of the N-glycolylneuraminic acid (NeuGc) antigen is slightly higher in the GalT-KO pigs. Thus, this study will contribute to a better understanding of cellular glycan alterations on GalT-KO pigs for successful xenotransplantation.


Assuntos
Fibroblastos/enzimologia , Galactosiltransferases/genética , Ácidos Neuramínicos/metabolismo , Polissacarídeos/isolamento & purificação , Animais , Membrana Celular/metabolismo , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/imunologia , Galactosiltransferases/metabolismo , Técnicas de Inativação de Genes , Espectrometria de Massas , Suínos
9.
Bioinformatics ; 29(22): 2950-2, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24013926

RESUMO

SUMMARY: In recent years, the improvement of mass spectrometry-based glycomics techniques (i.e. highly sensitive, quantitative and high-throughput analytical tools) has enabled us to obtain a large dataset of glycans. Here we present a database named Xeno-glycomics database (XDB) that contains cell- or tissue-specific pig glycomes analyzed with mass spectrometry-based techniques, including a comprehensive pig glycan information on chemical structures, mass values, types and relative quantities. It was designed as a user-friendly web-based interface that allows users to query the database according to pig tissue/cell types or glycan masses. This database will contribute in providing qualitative and quantitative information on glycomes characterized from various pig cells/organs in xenotransplantation and might eventually provide new targets in the α1,3-galactosyltransferase gene-knock out pigs era. AVAILABILITY: The database can be accessed on the web at http://bioinformatics.snu.ac.kr/xdb.


Assuntos
Bases de Dados de Compostos Químicos , Glicômica , Polissacarídeos/química , Suínos , Animais , Internet , Espectrometria de Massas , Software
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...