Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45.574
Filtrar
Mais filtros








Intervalo de ano de publicação
1.
Carbohydr Polym ; 338: 122090, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38763704

RESUMO

Size exclusion chromatography (SEC) and pyrene excimer formation (PEF) experiments were conducted to characterize the local density profile inside a glycogen sample before (Glycogen) and after (Gly-ß-LD) treatment with ß-amylase. These experiments were conducted to assess whether the density at the periphery of the glycogen particles was very high to limit access to proteins involved in the metabolism of glycogen as predicted by the Tier model or low as suggested by the Gilbert model. SEC analysis indicated that the density inside the Glycogen and Gly-ß-LD samples remained constant with particle size and was not affected by ß-amylolysis. Analysis of the PEF experiments conducted on the Glycogen and Gly-ß-LD samples labeled with 1-pyrenebutyric acid showed that the particles have a dense interior and loose corona. The conclusions reached by the SEC and PEF experiments agree with the Gilbert model and have implications for the association of glycogen ß-particles into larger α-particles.


Assuntos
Cromatografia em Gel , Glicogênio , Tamanho da Partícula , Pirenos , Pirenos/química , Glicogênio/química , Cromatografia em Gel/métodos , beta-Amilase/metabolismo , beta-Amilase/química , Fluorescência
2.
ACS Appl Bio Mater ; 7(5): 3460-3468, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38703374

RESUMO

Trimethylamine N-oxide (TMAO), a molecule produced by the microbiota, has been associated with human health and illness. Its early discovery in body fluids may affect our understanding of the pathophysiology and treatment of many illnesses. Therefore, our knowledge of the pathophysiology and diagnostics of disorders associated with TMAO might be enhanced by the creation of dependable and fast methods for TMAO detection. Therefore, we developed a fluorescent probe for detecting TMAO utilizing an on-off-on strategy. Bovine serum albumin (BSA)@AuNCs luminescence is effectively quenched by Mo4+ because BSA@AuNCs and Mo4+ have a strong binding relationship. Mo4+ ions can substantially decrease the emission intensity of gold nanoclusters by establishing a BSA@AuNCs-Mo system. Then, the luminescence of BSA@AuNCs was restored due to the interaction between Mo4+ and TMAO. A significant linear relationship was seen between the emission intensity and TMAO concentration within the 0-201 µM range, with a detection limit of 1.532 µM. Additionally, the method can measure TMAO in blood and urine samples.


Assuntos
Corantes Fluorescentes , Ouro , Teste de Materiais , Nanopartículas Metálicas , Metilaminas , Tamanho da Partícula , Soroalbumina Bovina , Metilaminas/química , Ouro/química , Soroalbumina Bovina/química , Nanopartículas Metálicas/química , Humanos , Corantes Fluorescentes/química , Materiais Biocompatíveis/química , Bovinos , Animais , Fluorescência , Espectrometria de Fluorescência , Estrutura Molecular
3.
Molecules ; 29(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38731451

RESUMO

A novel second-generation blue fluorescent polyamidoamine dendrimer peripherally modified with sixteen 4-N,N-dimethylaninoethyloxy-1,8-naphthalimide units was synthesized. Its basic photophysical characteristics were investigated in organic solvents of different polarity. It was found that in these solvents, the dendrimer is colorless and emitted blue fluorescence with different intensities depending on their polarity. The effect of the pH of the medium on the fluorescence intensity was investigated and it was found that in the acidic medium, the fluorescence is intense and is quenched in the alkaline medium. The ability of the dendrimer to detect metal ions (Pb2+, Zn2+, Mg2+, Sn2+, Ba2+, Ni2+, Sn2+, Mn2+, Co2+, Fe3+, and Al3+) was also investigated, and it was found that in the presence of Fe3+, the fluorescent intensity was amplified more than 66 times. The antimicrobial activity of the new compound has been tested in vitro against Gram-positive B. cereus and Gram-negative P. aeruginosa. The tests were performed in the dark and after irradiation with visible light. The antimicrobial activity of the compound enhanced after light irradiation and B. cereus was found slightly more sensitive than P. aeruginosa. The increase in antimicrobial activity after light irradiation is due to the generation of singlet oxygen particles, which attack bacterial cell membranes.


Assuntos
Dendrímeros , Testes de Sensibilidade Microbiana , Naftalimidas , Poliaminas , Naftalimidas/química , Naftalimidas/farmacologia , Dendrímeros/química , Dendrímeros/farmacologia , Poliaminas/química , Poliaminas/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Fluorescência , Pseudomonas aeruginosa/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Bacillus cereus/efeitos dos fármacos , Luz , Corantes Fluorescentes/química , Espectrometria de Fluorescência
4.
Luminescence ; 39(5): e4769, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38720528

RESUMO

Fluorene nucleus derivatives show great potential for building outstanding fluorescence probes. In this paper, a novel fluorescent probe was developed by reacting with fluorene core with azacyclobutane, which exhibits typical solvation chromogenic effect in solvent. The fluorescence of the probe quenched in highly polar solvent. Based on this phenomenon, a novel fluorescence system for trace water was constructed. The response of this probe was fast (30 s) and sensitive for the detection of trace water in organic solvents, and the detection limit of water content in DMSO reached 0.13%. In addition, the probe can also be made as a test strip combined with homemade portable device and a smartphone for rapid detection of trace water. The luminescence mechanism of the probe is theoretically calculated based on time-contained density functional theory (TDDFT). To showcase its practicality, it has been applied for the detection of trace water in honey and alcohol by dipstick. This method provides a new idea for designing efficient fluorescent probes based on dipstick and mobile phone rapid detection.


Assuntos
Fluorenos , Corantes Fluorescentes , Espectrometria de Fluorescência , Água , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Fluorenos/química , Água/química , Estrutura Molecular , Limite de Detecção , Teoria da Densidade Funcional , Fluorescência , Poluentes Químicos da Água/análise
5.
J Robot Surg ; 18(1): 209, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38727915

RESUMO

This study aimed to report our experience in indocyanine green (ICG) fluorescence-guided surgery (FGS) in pediatric robotics. The data of 55 patients (35 boys and 20 girls), who underwent robotic surgery using ICG fluorescence in three institutions over the last 7 years, were retrospectively reviewed. The following robotic procedures were included: pyeloplasty (n = 21), complex Lich-Gregoir ureteral reimplantation (n = 8), varicocelectomy (n = 7), adnexal pathology resection (n = 8), partial nephrectomy (n = 4), nephrectomy (n = 4), renal cyst removal (n = 2), and excision of prostatic utricle (n = 1). The ICG was injected intravenously in all indications except for varicocele where intratesticular injection was done, and prostatic utricle or paraureteral diverticulum where trans-catheter injection was done. The ICG dosage was 0.2-0.3 mg/mL/kg. All the procedures were performed using da Vinci Xi platform. Firefly® allowed to switch form bright light to ICG-NIRF view and vice versa. All the procedures were accomplished in robotics without conversions to laparoscopy or open surgery. No episodes of allergy or anaphylaxis to ICG were recorded. An excellent ICG-NIRF view of target organs was obtained in all procedures. Based on our experience, we believe that application of ICG FGS in pediatric robotics enhances the identification of critical anatomical elements and pathological structures, thereby positively impacting both oncological and functional outcomes. This technique is safe, feasible, and versatile. We advocate the consideration of ICG as the standard of care in certain procedures such as partial nephrectomy, varicocele repair, tumor resection, and ovarian torsion. Nonetheless, further investigations are warranted to explore its potential broader applications in pediatric urology.


Assuntos
Verde de Indocianina , Procedimentos Cirúrgicos Robóticos , Humanos , Verde de Indocianina/administração & dosagem , Procedimentos Cirúrgicos Robóticos/métodos , Feminino , Masculino , Criança , Estudos Retrospectivos , Pré-Escolar , Adolescente , Lactente , Fluorescência , Nefrectomia/métodos , Cirurgia Assistida por Computador/métodos
6.
Int J Mol Sci ; 25(9)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38731924

RESUMO

Förster resonance energy transfer (FRET) spectrometry is a method for determining the quaternary structure of protein oligomers from distributions of FRET efficiencies that are drawn from pixels of fluorescence images of cells expressing the proteins of interest. FRET spectrometry protocols currently rely on obtaining spectrally resolved fluorescence data from intensity-based experiments. Another imaging method, fluorescence lifetime imaging microscopy (FLIM), is a widely used alternative to compute FRET efficiencies for each pixel in an image from the reduction of the fluorescence lifetime of the donors caused by FRET. In FLIM studies of oligomers with different proportions of donors and acceptors, the donor lifetimes may be obtained by fitting the temporally resolved fluorescence decay data with a predetermined number of exponential decay curves. However, this requires knowledge of the number and the relative arrangement of the fluorescent proteins in the sample, which is precisely the goal of FRET spectrometry, thus creating a conundrum that has prevented users of FLIM instruments from performing FRET spectrometry. Here, we describe an attempt to implement FRET spectrometry on temporally resolved fluorescence microscopes by using an integration-based method of computing the FRET efficiency from fluorescence decay curves. This method, which we dubbed time-integrated FRET (or tiFRET), was tested on oligomeric fluorescent protein constructs expressed in the cytoplasm of living cells. The present results show that tiFRET is a promising way of implementing FRET spectrometry and suggest potential instrument adjustments for increasing accuracy and resolution in this kind of study.


Assuntos
Estudos de Viabilidade , Transferência Ressonante de Energia de Fluorescência , Microscopia de Fluorescência , Transferência Ressonante de Energia de Fluorescência/métodos , Microscopia de Fluorescência/métodos , Humanos , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Fluorescência Verde/química , Espectrometria de Fluorescência/métodos , Proteínas Luminescentes/química , Proteínas Luminescentes/metabolismo , Fluorescência
7.
Anal Chem ; 96(19): 7353-7359, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38690857

RESUMO

Accurate detection of multiple cardiovascular biomarkers is crucial for the timely screening of acute coronary syndrome (ACS) and differential diagnosis from acute aortic syndrome (AAS). Herein, an antibody microarray-based metal-enhanced fluorescence assay (AMMEFA) has been developed to quantitatively detect 7 cardiovascular biomarkers through the formation of a sandwich immunoassay on the poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate)-decorated GNR-modified slide (GNR@P(GMA-HEMA) slide). The AMMEFA exhibits high specificity and sensitivity, the linear ranges span 5 orders of magnitude, and the limits of detection (LODs) of cardiac troponin I (cTnI), heart-type fatty acid binding protein (H-FABP), C-reactive protein (CRP), copeptin, myoglobin, D-Dimer, and N-terminal pro-brain natriuretic peptide (NT-proBNP) reach 0.07, 0.2, 65.7, 0.6, 0.2, 8.3, and 0.3 pg mL-1, respectively. To demonstrate its practicability, the AMMEFA has been applied to quantitatively analyze 7 cardiovascular biomarkers in 140 clinical plasma samples. In addition, the expression levels of cardiovascular biomarkers were analyzed by the least absolute shrinkage and selector operator (LASSO) regression, and the area under receiver operator characteristic curves (AUCs) of healthy donors (HDs), ACS patients, and AAS patients are 0.99, 0.98, and 0.97, respectively.


Assuntos
Biomarcadores , Humanos , Biomarcadores/sangue , Biomarcadores/análise , Análise Serial de Proteínas/métodos , Limite de Detecção , Imunoensaio/métodos , Fluorescência
8.
Anal Chim Acta ; 1306: 342586, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38692787

RESUMO

BACKGROUND: Early prostatic cancer (PCa) diagnosis significantly improves the chances of successful treatment and enhances patient survival rates. Traditional enzyme cascade-based early cancer detection methods offer efficiency and signal amplification but are limited by cost, complexity, and enzyme dependency, affecting stability and practicality. Meanwhile, sarcosine (Sar) is commonly considered a biomarker for PCa development. It is essential to develop a Sar detection method based on cascade reactions, which should be efficient, low skill requirement, and suitable for on-site testing. RESULTS: To address this, our study introduces the synthesis of organic-inorganic self-assembled nanoflowers to optimize existing detection methods. The Sar oxidase (SOX)-inorganic hybrid nanoflowers (Cu3(PO4)2:Ce@SOX) possess inherent fluorescent properties and excellent peroxidase activity, coupled with efficient enzyme loading. Based on this, we have developed a dual-mode multi-enzyme cascade nanoplatform combining fluorescence and colorimetric methods for the detection of Sar. The encapsulation yield of Cu3(PO4)2:Ce@SOX reaches 84.5 %, exhibiting a remarkable enhancement in catalytic activity by 1.26-1.29 fold compared to free SOX. The present study employing a dual-signal mechanism encompasses 'turn-off' fluorescence signals ranging from 0.5 µM to 60 µM, with a detection limit of 0.226 µM, and 'turn-on' colorimetric signals ranging from 0.18 µM to 60 µM, with a detection limit of 0.120 µM. SIGNIFICANCE: Furthermore, our study developed an intelligent smartphone sensor system utilizing cotton swabs for real-time analysis of Sar without additional instruments. The nano-platform exhibits exceptional repeatability and stability, rendering it well-suited for detecting Sar in authentic human urine samples. This innovation allows for immediate analysis, offering valuable insights for portable and efficient biosensors applicable to Sar and other analytes.


Assuntos
Colorimetria , Oxirredução , Sarcosina , Smartphone , Sarcosina/urina , Sarcosina/análise , Sarcosina/química , Humanos , Nanoestruturas/química , Limite de Detecção , Espectrometria de Fluorescência , Neoplasias da Próstata/diagnóstico , Fluorescência , Técnicas Biossensoriais , Sarcosina Oxidase/química
9.
Luminescence ; 39(5): e4743, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38692854

RESUMO

A unique luminescent lanthanide metal-organic framework (LnMOF)-based fluorescence detection platform was utilized to achieve sensitive detection of vomitoxin (VT) and oxytetracycline hydrochloride (OTC-HCL) without the use of antibodies or biomolecular modifications. The sensor had a fluorescence quenching constant of 9.74 × 106 M-1 and a low detection limit of 0.68 nM for vomitoxin. Notably, this is the first example of a Tb-MOF sensor for fluorescence detection of vomitoxin. We further investigated its response to two mycotoxins, aflatoxin B1 and ochratoxin A, and found that their Stern-Volmer fluorescence quenching constants were lower than those of VT. In addition, the fluorescence sensor realized sensitive detection of OTC-HCL with a detection limit of 0.039 µM. In conclusion, the method has great potential as a sensitive and simple technique to detect VT and OTC-HCL in water.


Assuntos
Estruturas Metalorgânicas , Oxitetraciclina , Térbio , Oxitetraciclina/análise , Oxitetraciclina/química , Térbio/química , Estruturas Metalorgânicas/química , Espectrometria de Fluorescência , Corantes Fluorescentes/química , Limite de Detecção , Água/química , Fluorescência , Poluentes Químicos da Água/análise
10.
Luminescence ; 39(5): e4747, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38716575

RESUMO

Atezolizumab (ATZ) is a human monoclonal antibody, which has been granted multiple approvals from the US Food and Drug Administration (FDA) for the immunotherapy of different types of cancer. This study describes the prototype of a time-resolved fluoroimmunoassay (TRFIA) for the quantitation of ATZ in plasma. The assay involved the non-competitive binding of ATZ to its specific antigen [programmed death-ligand 1 (PD-L1) protein]. The immune complex formed on the inner surface of the assay plate wells was quantified by anti-human secondary antibody labeled with a chelate of europium-ethylenediaminetetraacetic acid. The enhanced fluorescence signal was generated by an enhanced fluorescence solution composed of thenoyltrifluoroacetone, trioctylphosphine oxide, and Triton X-100. The conditions of the TRFIA were refined, and its optimum procedures were established. The assay was validated in accordance with the immunoassay validation guidelines, and all the validation parameters were acceptable. The working range of the assay was 20-1000 pg mL-1, and its limit of quantitation was 20 pg mL-1. The assay was applied to the quantitation of ATZ in plasma samples with satisfactory accuracy and precision. The proposed TRFIA has significant benefits over the existing methodologies for the quantitation of ATZ in clinical settings.


Assuntos
Anticorpos Monoclonais Humanizados , Fluorimunoensaio , Fluorimunoensaio/métodos , Humanos , Anticorpos Monoclonais Humanizados/sangue , Anticorpos Monoclonais Humanizados/química , Anticorpos Monoclonais Humanizados/imunologia , Fluorescência , Fatores de Tempo
11.
J Am Chem Soc ; 146(19): 13163-13175, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38698548

RESUMO

A pretargeted strategy that decouples targeting vectors from radionuclides has shown promise for nuclear imaging and/or therapy in vivo. However, the current pretargeted approach relies on the use of antibodies or nanoparticles as the targeting vectors, which may be compromised by poor tissue penetration and limited accumulation of targeting vectors in the tumor tissues. Herein, we present an orthogonal dual-pretargeted approach by combining stimuli-triggered in situ self-assembly strategy with fast inverse electron demand Diels-Alder (IEDDA) reaction and strong biotin-streptavidin (SA) interaction for near-infrared fluorescence (NIR FL) and magnetic resonance (MR) imaging of tumors. This approach uses a small-molecule probe (P-Cy-TCO&Bio) containing both biotin and trans-cyclooctene (TCO) as a tumor-targeting vector. P-Cy-TCO&Bio can efficiently penetrate subcutaneous HeLa tumors through biotin-assisted targeted delivery and undergo in situ self-assembly to form biotinylated TCO-bearing nanoparticles (Cy-TCO&Bio NPs) on tumor cell membranes. Cy-TCO&Bio NPs exhibited an "off-on" NIR FL and retained in the tumors, offering a high density of TCO and biotin groups for the concurrent capture of Gd-chelate-labeled tetrazine (Tz-Gd) and IR780-labeled SA (SA-780) via the orthogonal IEDDA reaction and SA-biotin interaction. Moreover, Cy-TCO&Bio NPs offered multiple-valent binding modes toward SA, which additionally regulated the cross-linking of Cy-Gd&Bio NPs into microparticles (Cy-Gd&Bio/SA MPs). This process could significantly (1) increase r1 relaxivity and (2) enhance the accumulation of Tz-Gd and SA-780 in the tumors, resulting in strong NIR FL, bright MR contrast, and an extended time window for the clear and precise imaging of HeLa tumors.


Assuntos
Biotina , Ciclo-Octanos , Imageamento por Ressonância Magnética , Nanopartículas , Ciclo-Octanos/química , Humanos , Nanopartículas/química , Imageamento por Ressonância Magnética/métodos , Células HeLa , Biotina/química , Animais , Imagem Óptica , Biotinilação , Camundongos , Estreptavidina/química , Reação de Cicloadição , Fluorescência
12.
J Agric Food Chem ; 72(19): 11241-11250, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38709728

RESUMO

The fungicide phenamacril has been employed to manage Fusarium and mycotoxins in crops, leading to persistent residues in the environment and plants. Detecting phenamacril is pivotal for ensuring environmental and food safety. In this study, haptens and artificial antigens were synthesized to produce antiphenamacril monoclonal antibodies (mAbs). Additionally, gold nanoparticles coated with a polydopamine shell were synthesized and conjugated with mAbs, inducing fluorescence quenching in quantum dots. Moreover, a dual-readout immunochromatographic assay that combines the positive signal from fluorescence with the negative signal from colorimetry was developed to enable sensitive and precise detection of phenamacril within 10 min, achieving detection limits of 5 ng/mL. The method's reliability was affirmed by using spiked wheat flour samples, achieving a limit of quantitation of 0.05 mg/kg. This analytical platform demonstrates high sensitivity, outstanding accuracy, and robust tolerance to matrix effects, making it suitable for the rapid, onsite, quantitative screening of phenamacril residues.


Assuntos
Colorimetria , Contaminação de Alimentos , Fungicidas Industriais , Resíduos de Praguicidas , Fungicidas Industriais/análise , Contaminação de Alimentos/análise , Colorimetria/métodos , Resíduos de Praguicidas/análise , Anticorpos Monoclonais/química , Cromatografia de Afinidade/métodos , Cromatografia de Afinidade/instrumentação , Fluorescência , Triticum/química , Nanopartículas Metálicas/química , Ouro/química , Limite de Detecção , Farinha/análise
13.
Anal Methods ; 16(19): 3099-3108, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38695127

RESUMO

The CRISPR-Cas system has been found to be extremely sensitive and there is an urgent demand to extend its potential in bioassays. Herein, we developed a novel nanobiosensor to detect the human papillomavirus 16 genes (HPV-16 DNA), which is triggered by CRISPR-Cas12a to amplify the fluorescence signal by metal-enhanced fluorescence (CAMEF). Along with the changing of the fluorescence signal, the aggregation of the substrate of MEF also leads to a change in the color of the mixture solution, enabling dual signal detection with the fluorescence and the naked eye. Furthermore, the designed CAMEF probe was verified to detect the HPV-16 DNA accurately and reliably in biological samples. Triggered by the CRISPR system, the designed CAMEF probe allows quantitative detection of the HPV-16 DNA in the wide range of 10-500 pM. Owing to the MEF, the fluorescence signal of the CAMEF probe was significantly amplified with the detection limit as low as 1 pM. Besides, we can determine the concentration of HPV-16 DNA simply by the naked eye, which also drastically reduces the possibility of false-positive signals. Theoretically, the target ssDNA could be any strand of DNA obtained by designing the crRNA sequence in the CRISPR-Cas system. We believe that the designed CAMEF sensor can present a reliable approach for the accurate detection of low amounts of target ssDNA in complex biological samples.


Assuntos
Técnicas Biossensoriais , Sistemas CRISPR-Cas , Colorimetria , DNA Viral , Papillomavirus Humano 16 , Sistemas CRISPR-Cas/genética , Papillomavirus Humano 16/genética , Colorimetria/métodos , Humanos , DNA Viral/análise , DNA Viral/genética , Técnicas Biossensoriais/métodos , Limite de Detecção , Fluorescência , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos
14.
PLoS One ; 19(5): e0287088, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38771771

RESUMO

A variety of costly research-grade imaging devices are available for the detection of spectroscopic features. Here we present an affordable, open-source and versatile device, suitable for a range of applications. We provide the files to print the imaging chamber with commonly available 3D printers and instructions to assemble it with easily available hardware. The imager is suitable for rapid sample screening in research, as well as for educational purposes. We provide details and results for an already proven set-up which suits the needs of a research group and students interested in UV-induced near-infrared fluorescence detection of microbial colonies grown on Petri dishes. The fluorescence signal confirms the presence of bacteriochlorophyll a in aerobic anoxygenic phototrophic bacteria (AAPB). The imager allows for the rapid detection and subsequent isolation of AAPB colonies on Petri dishes with diverse environmental samples. To this date, 15 devices have been build and more than 7000 Petri dishes have been analyzed for AAPB, leading to over 1000 new AAPB isolates. Parts can be modified depending on needs and budget. The latest version with automated switches and double band pass filters costs around 350€ in materials and resolves bacterial colonies with diameters of 0.5 mm and larger. The low cost and modular build allow for the integration in high school classes to educate students on light properties, fluorescence and microbiology. Computer-aided design of 3D-printed parts and programming of the employed Raspberry Pi computer could be incorporated in computer sciences classes. Students have been also inspired to do agar art with microbes. The device is currently used in seven different high schools in Finland. Additionally, a science education network of Finnish universities has incorporated it in its program for high school students. Video guides have been produced to facilitate easy operation and accessibility of the device.


Assuntos
Espectroscopia de Luz Próxima ao Infravermelho , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Fluorescência , Processos Fototróficos , Imagem Óptica/métodos , Imagem Óptica/instrumentação
15.
Luminescence ; 39(5): e4778, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38772865

RESUMO

To establish a new method for detecting crystal violet (CV), a harmful dye, herein, a genre of novel biomass carbon dots (CDs) was synthesized via a microwave method and employed as a fluorescent probe, in which water spinach and polyethylene glycol (PEG) performed as raw materials. Based on the inner filter effect (IFE) between the luminescent CDs and CV, the blue emission of this probe at 430 nm could be quenched by CV. Hence, a new strategy was proposed to selectively determine CV in aquaculture ambient. Moreover, under the optimal experiment conditions, this method showed a good linearity between the concentration of CV (c) and fluorescence quenching rate (ΔF/F0) in the concentration range of 4-200 µmol/L with the corresponding correlation coefficient (r) and the detection limit of 0.997 and 710 nmol/L, respectively. With advantages of environmental protectivity, sensitivity, affordability, and user-friendliness, the facilely fabricated CDs could be successfully applied in detecting CV in aquaculture samples, providing a technical foundation for monitoring the pollution of CV and ensuring the quality and safety of aquatic products.


Assuntos
Biomassa , Carbono , Corantes Fluorescentes , Violeta Genciana , Micro-Ondas , Pontos Quânticos , Violeta Genciana/química , Carbono/química , Pontos Quânticos/química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Espectrometria de Fluorescência , Fluorescência , Polietilenoglicóis/química
16.
Sci Total Environ ; 931: 172866, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38705291

RESUMO

Tetracycline antibiotics (TCs) are extensively used in clinical medicine, animal husbandry, and aquaculture because of their cost-effectiveness and high antibacterial efficacy. However, the presence of TCs residues in the environment poses risks to humans. In this study, an inner filter effect (IFE) fluorescent probe, 2,2'-(ethane-1,2-diylbis((2-((2-methylquinolin-8-yl)amino)-2-oxoethyl)azanediyl))diacetic acid (MQDA), was developed for the rapid detection of Eu3+ within 30 s. And its complex [MQDA-Eu3+] was successfully used for the detection of TCs. Upon coordination of a carboxyl of MQDA with Eu3+ to form a [MQDA-Eu3+] complex, the carboxyl served as an antenna ligand for the effective detection of Eu3+ to intensify the emission intensity of MQDA via "antenna effect", the process was the energy absorbed by TCs via UV excitation was effectively transferred to Eu3+. Fluorescence quenching of the [MQDA-Eu3+] complex was caused by the IFE in multicolor fluorescence systems. The limits of detection of [MQDA-Eu3+] for oxytetracycline, chlorotetracycline hydrochloride, and tetracycline were 0.80, 0.93, and 1.7 µM in DMSO/HEPES (7:3, v/v, pH = 7.0), respectively. [MQDA-Eu3+] demonstrated sensitive detection of TCs in environmental and food samples with satisfactory recoveries and exhibited excellent imaging capabilities for TCs in living cells and zebrafish with low cytotoxicity. The proposed approach demonstrated considerable potential for the quantitative detection of TCs.


Assuntos
Antibacterianos , Európio , Corantes Fluorescentes , Antibacterianos/análise , Corantes Fluorescentes/química , Európio/química , Tetraciclina/análise , Tetraciclinas/análise , Animais , Poluentes Químicos da Água/análise , Fluorescência , Monitoramento Ambiental/métodos , Espectrometria de Fluorescência/métodos
17.
Int J Med Robot ; 20(3): e2636, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38757434

RESUMO

BACKGROUND: To assess the feasibility of use of indocyanine green (ICG) in identifying and minimising urinary tract injury during surgical resection of endometriosis through robotic transvaginal natural orifice transluminal endoscopy surgery (RvNOTES). METHODS: We conducted a retrospective case series in two academic tertiary care hospitals. We examined 53 patients who underwent RvNOTES hysterectomy with planned endometriosis resection. RESULTS: The study involved 53 patients undergoing RvNOTES with ICG fluorescence for endometriosis resection. Mean patient age was 37.98 ± 6.65 years. Operative time averaged 181.32 ± 53.94 min, with estimated blood loss at 45.57 ± 33.62 mL. Postoperative stay averaged 0.23 ± 0.47 days. No ICG-related complications occurred. CONCLUSION: No complications occurred with ICG fluorescence in RvNOTES. It appears to be a safe option for ureteral localisation and preservation. ICG fluorescence is widely used in diverse medical specialities for identifying ureters during complex surgeries. Larger studies are needed to firmly establish its advantages in intraoperative ureteral visualisation during RvNOTES for deep infiltrative endometriosis.


Assuntos
Endometriose , Estudos de Viabilidade , Verde de Indocianina , Cirurgia Endoscópica por Orifício Natural , Procedimentos Cirúrgicos Robóticos , Ureter , Humanos , Feminino , Endometriose/cirurgia , Endometriose/diagnóstico por imagem , Procedimentos Cirúrgicos Robóticos/métodos , Adulto , Estudos Retrospectivos , Cirurgia Endoscópica por Orifício Natural/métodos , Ureter/cirurgia , Pessoa de Meia-Idade , Fluorescência , Vagina/cirurgia , Duração da Cirurgia , Histerectomia/métodos
18.
Biomacromolecules ; 25(5): 3055-3062, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38693874

RESUMO

Polymersomes, nanosized polymeric vesicles, have attracted significant interest in the areas of artificial cells and nanomedicine. Given their size, their visualization via confocal microscopy techniques is often achieved through the physical incorporation of fluorescent dyes, which however present challenges due to potential leaching. A promising alternative is the incorporation of molecules with aggregation-induced emission (AIE) behavior that are capable of fluorescing exclusively in their assembled state. Here, we report on the use of AIE polymersomes as artificial organelles, which are capable of undertaking enzymatic reactions in vitro. The ability of our polymersome-based artificial organelles to provide additional functionality to living cells was evaluated by encapsulating catalytic enzymes such as a combination of glucose oxidase/horseradish peroxidase (GOx/HRP) or ß-galactosidase (ß-gal). Via the additional incorporation of a pyridinium functionality, not only the cellular uptake is improved at low concentrations but also our platform's potential to specifically target mitochondria expands.


Assuntos
Glucose Oxidase , Peroxidase do Rábano Silvestre , beta-Galactosidase , Glucose Oxidase/química , Humanos , beta-Galactosidase/química , beta-Galactosidase/metabolismo , Peroxidase do Rábano Silvestre/química , Peroxidase do Rábano Silvestre/metabolismo , Organelas/metabolismo , Corantes Fluorescentes/química , Polímeros/química , Fluorescência , Células HeLa , Mitocôndrias/metabolismo
19.
Proc Natl Acad Sci U S A ; 121(15): e2321255121, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38564632

RESUMO

Omega-3 polyunsaturated fatty acids (PUFA) found primarily in fish oil have been a popular supplement for cardiovascular health because they can substantially reduce circulating triglyceride levels in the bloodstream to prevent atherosclerosis. Beyond this established extracellular activity, here, we report a mode of action of PUFA, regulating intracellular triglyceride metabolism and lipid droplet (LD) dynamics. Real-time imaging of the subtle and highly dynamic changes of intracellular lipid metabolism was enabled by a fluorescence lifetime probe that addressed the limitations of intensity-based fluorescence quantifications. Surprisingly, we found that among omega-3 PUFA, only docosahexaenoic acid (DHA) promoted the lipolysis in LDs and reduced the overall fat content by approximately 50%, and consequently helped suppress macrophage differentiation into foam cells, one of the early steps responsible for atherosclerosis. Eicosapentaenoic acid, another omega-3 FA in fish oil, however, counteracted the beneficial effects of DHA on lipolysis promotion and cell foaming prevention. These in vitro findings warrant future validation in vivo.


Assuntos
Aterosclerose , Ácidos Graxos Ômega-3 , Humanos , Lipólise , Fluorescência , Ácidos Graxos Ômega-3/metabolismo , Óleos de Peixe/farmacologia , Ácidos Docosa-Hexaenoicos/metabolismo , Macrófagos/metabolismo , Triglicerídeos
20.
PLoS One ; 19(4): e0298072, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38593116

RESUMO

As a result of oat (Avena sativa L.) × maize (Zea mays L.) crossing, maize chromosomes may not be completely eliminated at the early stages of embryogenesis, leading to the oat × maize addition (OMA) lines development. Introgression of maize chromosomes into oat genome can cause morphological and physiological modifications. The aim of the research was to evaluate the leaves' anatomy, chlorophyll a fluorescence, and yield parameter of oat doubled haploid (DH) and OMA lines obtained by oat × maize crossing. The present study examined two DH and two disomic OMA lines and revealed that they differ significantly in the majority of studied traits, apart from: the number of cells of the outer bundle sheath; light energy absorption; excitation energy trapped in PSII reaction centers; and energy dissipated from PSII. The OMA II line was characterized by larger size of single cells in the outer bundle sheath and greater number of seeds per plant among tested lines.


Assuntos
Avena , Zea mays , Zea mays/genética , Clorofila A , Avena/genética , Haploidia , Fluorescência , Clorofila
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA