Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Sensors (Basel) ; 23(4)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36850852

RESUMO

Quantum dots have found significant applications in photoelectric detectors due to their unique electronic and optical properties, such as tunable bandgap. Recently, colloidal quantum dots (CQDs) have attracted much interest because of the ease of controlling the dot size and low production cost. In this paper, a high-performance ZnO/PbS heterojunction photodetector was fabricated by spin-coating PbS CQDs onto the surface of a hydrothermally grown vertical array of ZnO nanowires (NWs) on an indium tin oxide (ITO) substrate. Under 940 nm near-infrared light illumination, the device demonstrated a responsivity and detectivity of ~3.9 × 104 A/W and ~9.4 × 1013 Jones, respectively. The excellent performances and low cost of this nanocomposite-based photodetector show that it has the potential for widespread applications ranging from medical diagnosis to environmental monitoring.

2.
Sensors (Basel) ; 23(9)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37177533

RESUMO

Lead sulfide colloidal quantum dots (PbS CQDs) are promising optoelectronic materials due to their unique properties, such as tunable band gap and strong absorption, which are of immense interest for application in photodetectors and solar cells. However, the tunable band gap of PbS CQDs would only cover visible short-wave infrared; the ability to detect longer wavelengths, such as mid- and long-wave infrared, is limited because they are restricted by the band gap of the bulk material. In this paper, a novel photodetector based on the synergistic effect of PbS CQDs and bismuth telluride (Bi2Te3) was developed for the detection of a mid-wave infrared band at room temperature. The device demonstrated good performance in the visible-near infrared band (i.e., between 660 and 850 nm) with detectivity of 1.6 × 1010 Jones at room temperature. It also exhibited photoelectric response in the mid-wave infrared band (i.e., between 4.6 and 5.1 µm). The facile fabrication process and excellent performance (with a response of up to 5.1 µm) of the hybrid Bi2Te3/PbS CQDS photodetector are highly attractive for many important applications that require high sensitivity and broadband light detection.

3.
Mar Drugs ; 20(10)2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36286457

RESUMO

The "blue shark", Prionace glauca (class: Chondrichthyes), is a pelagic shark species commonly found in tropical and temperate oceans. This shark is mainly sold in Asian countries as food and as traditional Chinese medicine. According to the Red List of the International Union for the Conservation of Nature, P. glauca is classified as low-risk to near endangered. P. glauca cartilage contains collagen type II, which makes it suitable as a bioactive ingredient in cosmeceutical products. This study evaluated the effects of a gel containing various concentrations (0.125-5%) of lyophilized hydrolyzed P. glauca cartilage on the human inner wrist skin compared to a placebo (base). A skin properties evaluation test was conducted before and after applying various concentrations (0.125-5%) of the P. glauca cartilage gel for 10 and 20 min on the inner wrists of participants using a skin analyzer that determined the moisture level, oil level, texture level, complexion level, and the 3D level. Adding lyophilized hydrolyzed shark cartilage (LHSC) significantly improved the moisture, texture, and complexion of the skin while controlling oil and providing a wrinkle-smoothing effect. The result indicated that LHSC formulations were prepared at different concentrations, and they had significantly enhanced effects on skin hydration and elasticity (texture) and the smoothing of wrinkles (3D level). The LHSC also effectively controlled oil secretion and the complexion.


Assuntos
Cosmecêuticos , Cosméticos , Tubarões , Animais , Humanos , Colágeno Tipo II , Cosméticos/farmacologia
4.
J Org Chem ; 78(22): 11318-25, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24199599

RESUMO

A series of donor-acceptor systems incorporating a carbazole moiety as the donating unit and pyridine moiety as the accepting unit have been designed and synthesized. The spectroscopic and electrochemical behaviors of the carbazole derivatives demonstrate that the carbazole unit interacts with the electron-accepting group through the π-conjugated spacer, thus leading to the intramolecular charge transfer (ICT). The pyridine-substituted carbazole derivatives show significant sensing and coordinating properties toward a wide range of metal cations. Compound S2 exhibits fluorescence enhancement upon association with transition metal cations, and compound V3 shows high selectivity for Cu(2+) among this series of materials. DFT calculations indicate the different association abilities of the dyes and the enhancement of ICT upon addition of the metal cations.

5.
Nanomaterials (Basel) ; 12(18)2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36145000

RESUMO

Colloidal quantum dots (CQDs) as photodetector materials have attracted much attention in recent years due to their tunable energy bands, low cost, and solution processability. However, their intrinsically low carrier mobility and three-dimensional (3D) confinement of charges are unsuitable for use in fast-response and highly sensitive photodetectors, hence greatly restricting their application in many fields. Currently, 3D topological insulators, such as bismuth telluride (Bi2Te3), have been employed in high-speed broadband photodetectors due to their narrow bulk bandgap, high carrier mobility, and strong light absorption. In this work, the advantages of topological insulators and CQDs were realized by developing a hybrid Bi2Te3/PbS CQDs photodetector that exhibited a maximum responsivity and detectivity of 18 A/W and 2.1 × 1011 Jones, respectively, with a rise time of 128 µs at 660 nm light illumination. The results indicate that such a photodetector has potential application in the field of fast-response and large-scale integrated optoelectronic devices.

6.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 3): o575, 2009 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-21582230

RESUMO

The crystal structure of the title compound, C(18)H(26)N(2)O(3), is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds. One of the methyl groups is disordered with occupancies of 0.51 (3):0.49 (3).

7.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 6): e16, 2009 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-21582974

RESUMO

The author list in the paper by Shu, Wen, Chen & Lei [Acta Cryst. (2009), E65, o575] is corrected.[This corrects the article DOI: 10.1107/S160053680900556X.].

8.
Nat Med ; 25(3): 433-438, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30742121

RESUMO

Artificial intelligence (AI)-based methods have emerged as powerful tools to transform medical care. Although machine learning classifiers (MLCs) have already demonstrated strong performance in image-based diagnoses, analysis of diverse and massive electronic health record (EHR) data remains challenging. Here, we show that MLCs can query EHRs in a manner similar to the hypothetico-deductive reasoning used by physicians and unearth associations that previous statistical methods have not found. Our model applies an automated natural language processing system using deep learning techniques to extract clinically relevant information from EHRs. In total, 101.6 million data points from 1,362,559 pediatric patient visits presenting to a major referral center were analyzed to train and validate the framework. Our model demonstrates high diagnostic accuracy across multiple organ systems and is comparable to experienced pediatricians in diagnosing common childhood diseases. Our study provides a proof of concept for implementing an AI-based system as a means to aid physicians in tackling large amounts of data, augmenting diagnostic evaluations, and to provide clinical decision support in cases of diagnostic uncertainty or complexity. Although this impact may be most evident in areas where healthcare providers are in relative shortage, the benefits of such an AI system are likely to be universal.


Assuntos
Aprendizado Profundo , Diagnóstico por Computador , Registros Eletrônicos de Saúde , Processamento de Linguagem Natural , Pediatria , Adolescente , Inteligência Artificial , Criança , Pré-Escolar , China , Feminino , Humanos , Lactente , Recém-Nascido , Aprendizado de Máquina , Masculino , Estudo de Prova de Conceito , Reprodutibilidade dos Testes , Estudos Retrospectivos
9.
Artigo em Inglês | MEDLINE | ID: mdl-23639735

RESUMO

Natural fibrous gypsum is colored electrolytically at near room temperatures and under various voltages using a pointed anode and a flat cathode. The SO4(-), SO3(-), SO2(-) and O(-) lattice defects are produced in the colored natural fibrous gypsum. No visible characteristic absorption band in the ultraviolet and visible wavelength regions is observed in the optical absorption spectrum of the natural fibrous gypsum before the electrolytic coloration. The characteristic absorption bands of the SO4(-), SO3(-), SO2(-) and O(-) lattice defects are observed in the optical absorption spectra of the colored natural fibrous gypsum. The production of the lattice defects is explained. Current-time curve for the electrolytic coloration of the natural fibrous gypsum and its relationship with the electrolytic coloration processes are given.


Assuntos
Sulfato de Cálcio/química , Eletrólise/métodos , Temperatura , Absorção , Cor , Eletricidade , Eletrodos , Análise Espectral , Fatores de Tempo
10.
China Journal of Endoscopy ; (12): 6-9, 2018.
Artigo em Chinês | WPRIM | ID: wpr-702875

RESUMO

Objective To evaluate the feasibility and safety of self designed oral-nasal double channel mask in painless gastroscopy. Methods 400 patients who were given intravenous injection Sublimaze followed by Propofol were divided equally at random into two groups. The patients in control group (n = 200) were inhaled oxygen with snuffle tube (4.0 ~ 5.0 L/min) and the patients in experimental group (n = 200) were inhaled oxygen with a self designed oral-nasal double channel mask. Respiration rate, SpO2, duration of operation and dosage of anaesthetic were recorded before and during operation. Result The SpO2decreased markedly and duration of operation obviously prolonged in group I during operation (P < 0.05), there was no statistical difference between the two groups of the respiration rate and dosage of anaesthetic. Conclusion The application of oxygen inhalation with the self designed oral-nasal double channel mask in painless gastroscopy appeared safer than that of oxygen inhalation via snuffle tube. It can be safely used in painless gastroscopy.

11.
Artigo em Inglês | MEDLINE | ID: mdl-22381802

RESUMO

Sucrose crystals are colored electrolytically at low temperatures and various voltages by using a pointed cathode and a flat anode. Caramels, carbonyl compounds, glycosylamines and free radicals are produced in colored sucrose crystals. No obvious characteristic absorption band in UV and visible wavelength regions is observed in absorption spectrum of uncolored sucrose crystal. Intense characteristic absorption bands of glycosylamines, carbonyl compounds and caramels are observed in absorption spectra of colored sucrose crystals. Production of caramels, carbonyl compounds, glycosylamines and free radicals are explained. Current-time curve for electrolytic coloration of sucrose crystal and its relationship with electrolytic coloration process are given.


Assuntos
Eletrólise , Sacarose/química , Temperatura Baixa , Cor , Cristalização , Espectrofotometria
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa