Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 9.527
Filtrar
1.
Ecotoxicol Environ Saf ; 203: 110984, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888605

RESUMO

The use of water for drinking and agriculture requires knowledge of its toxicity. In this study, we compared the use of genetically modified bioluminescent (GMB) bacteria whose luminescence increases in the presence of toxicants and Chinese Hamster Ovary (CHO) cells for the characterization of the toxicity of water samples collected from a lake and streams, hydroponic and aquaponic farms, and a wastewater treatment plant. GMB bacteria were used to probe genotoxicity, cytotoxicity and reactive oxygen species-induced effects in the whole water samples. Unlike GMB bacteria, the use of CHO cells requires XAD resin-based pre-concentration of toxic material present in water samples for the subsequent cytotoxicity assay. In addition to the examination of the toxicity of the water from the different sources, the GMB bacteria were also used to test the XAD extracts diluted to the concentrations causing 50% growth inhibition of the CHO cells. The two biomonitoring tools provided different results when they were used to test the above-mentioned diluted XAD extracts. A pre-concentration procedure based on adsorption by XAD resins with subsequent elution was not sufficient to represent the material responsible for the toxicity of the whole water samples toward the GMB bacteria. Therefore, the use of XAD resin extracts may lead to major underestimates of the toxicity of water samples. Although the toxicity findings obtained using the GMB bacteria and CHO cells may not correlate with each another, the GMB bacteria assay did provide a mechanism-specific biomonitoring tool to probe the toxicity of water samples without a need for the pre-concentration step.


Assuntos
Bactérias , Monitoramento Biológico/métodos , Água Potável/análise , Lagos/análise , Rios , Águas Residuárias/análise , Animais , Bactérias/genética , Células CHO , Cricetulus , Hidroponia , Luminescência , Microrganismos Geneticamente Modificados/genética , Eliminação de Resíduos Líquidos
2.
J Coll Physicians Surg Pak ; 30(8): 801-804, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32893789

RESUMO

OBJECTIVE: To determine the percentage of seroconverted real time reverse transcriptase polymerase chain reaction (RT-PCR) positive coronavirus disease (COVID-19) cases at different days post-symptom onset; and also find the agreement of chemiluminescence assay used for total antibody detection using RT-PCR as a reference method. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: Chughtai Institute of Pathology from April to May 2020. METHODOLOGY: Fifty pre-pandemic samples (healthy population) and 75 COVID-19 patients were included in the study. RT-PCR confirmed COVID-19 patients were divided into 3 equal groups (25 each), according to the days of symptom onset. The samples were analysed using electro-chemiluminescence as assay principle. Positive and negative agreement of COVID-19 antibodies was calculated using EP evaluator to find out the sensitivity of chemiluminescence assay for total antibody detection. The results were analysed using SPSS version 23.0. RESULTS: All the pre-pandemic samples tested were negative for antibodies with a negative agreement of 100%. Total agreement at day 7 post-symptom onset was 84%; whereas, it was 94% at day 14 and increased rapidly to 100% at day 21 post-symptom onset. At day 7 post-symptom onset, 68% of patients were seroconverted; and this percentage was 88% and 100% at day 14 and 21 post-symptom onset, respectively. CONCLUSION: Pre-pandemic samples were non-reactive for COVID-19 antibodies and seroconversion started within the first week post-virus exposure. There was 100% concordance between RT-PCR result and antibody positivity 21 days post-symptom onset. Key Words: COVID-19, SARS CoV-2, Seroconversion, Chemiluminescence.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/diagnóstico , Coronavirus/isolamento & purificação , Pneumonia Viral/diagnóstico , Adolescente , Adulto , Betacoronavirus , Coronavirus/genética , Coronavirus/imunologia , Infecções por Coronavirus/epidemiologia , Estudos Transversais , Feminino , Humanos , Luminescência , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco , Soroconversão
3.
J Coll Physicians Surg Pak ; 30(8): 801-804, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: covidwho-745629

RESUMO

OBJECTIVE: To determine the percentage of seroconverted real time reverse transcriptase polymerase chain reaction (RT-PCR) positive coronavirus disease (COVID-19) cases at different days post-symptom onset; and also find the agreement of chemiluminescence assay used for total antibody detection using RT-PCR as a reference method. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: Chughtai Institute of Pathology from April to May 2020. METHODOLOGY: Fifty pre-pandemic samples (healthy population) and 75 COVID-19 patients were included in the study. RT-PCR confirmed COVID-19 patients were divided into 3 equal groups (25 each), according to the days of symptom onset. The samples were analysed using electro-chemiluminescence as assay principle. Positive and negative agreement of COVID-19 antibodies was calculated using EP evaluator to find out the sensitivity of chemiluminescence assay for total antibody detection. The results were analysed using SPSS version 23.0. RESULTS: All the pre-pandemic samples tested were negative for antibodies with a negative agreement of 100%. Total agreement at day 7 post-symptom onset was 84%; whereas, it was 94% at day 14 and increased rapidly to 100% at day 21 post-symptom onset. At day 7 post-symptom onset, 68% of patients were seroconverted; and this percentage was 88% and 100% at day 14 and 21 post-symptom onset, respectively. CONCLUSION: Pre-pandemic samples were non-reactive for COVID-19 antibodies and seroconversion started within the first week post-virus exposure. There was 100% concordance between RT-PCR result and antibody positivity 21 days post-symptom onset. Key Words: COVID-19, SARS CoV-2, Seroconversion, Chemiluminescence.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/diagnóstico , Coronavirus/isolamento & purificação , Pneumonia Viral/diagnóstico , Adolescente , Adulto , Betacoronavirus , Coronavirus/genética , Coronavirus/imunologia , Infecções por Coronavirus/epidemiologia , Estudos Transversais , Feminino , Humanos , Luminescência , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco , Soroconversão
4.
Biosens Bioelectron ; 166: 112436, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32750677

RESUMO

Our recent experience of the COVID-19 pandemic has highlighted the importance of easy-to-use, quick, cheap, sensitive and selective detection of virus pathogens for the efficient monitoring and treatment of virus diseases. Early detection of viruses provides essential information about possible efficient and targeted treatments, prolongs the therapeutic window and hence reduces morbidity. Graphene is a lightweight, chemically stable and conductive material that can be successfully utilized for the detection of various virus strains. The sensitivity and selectivity of graphene can be enhanced by its functionalization or combination with other materials. Introducing suitable functional groups and/or counterparts in the hybrid structure enables tuning of the optical and electrical properties, which is particularly attractive for rapid and easy-to-use virus detection. In this review, we cover all the different types of graphene-based sensors available for virus detection, including, e.g., photoluminescence and colorimetric sensors, and surface plasmon resonance biosensors. Various strategies of electrochemical detection of viruses based on, e.g., DNA hybridization or antigen-antibody interactions, are also discussed. We summarize the current state-of-the-art applications of graphene-based systems for sensing a variety of viruses, e.g., SARS-CoV-2, influenza, dengue fever, hepatitis C virus, HIV, rotavirus and Zika virus. General principles, mechanisms of action, advantages and drawbacks are presented to provide useful information for the further development and construction of advanced virus biosensors. We highlight that the unique and tunable physicochemical properties of graphene-based nanomaterials make them ideal candidates for engineering and miniaturization of biosensors.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Grafite , Pneumonia Viral/diagnóstico , Vírus/isolamento & purificação , Reações Antígeno-Anticorpo , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/tendências , Técnicas de Laboratório Clínico/instrumentação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/estatística & dados numéricos , Colorimetria , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , DNA Viral/análise , DNA Viral/genética , Técnicas Eletroquímicas , Desenho de Equipamento , Grafite/química , Humanos , Luminescência , Nanoestruturas/química , Hibridização de Ácido Nucleico , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Pontos Quânticos/química , Análise Espectral Raman , Ressonância de Plasmônio de Superfície , Virologia/métodos , Vírus/genética , Vírus/patogenicidade
5.
Nat Commun ; 11(1): 4052, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792510

RESUMO

Turn-on fluorescence imaging is routinely studied; however, turn-on chemiluminescence has been rarely explored for in vivo imaging. Herein, we report the design and validation of chemiluminescence probe ADLumin-1 as a turn-on probe for amyloid beta (Aß) species. Two-photon imaging indicates that ADLumin-1 can efficiently cross the blood-brain barrier and provides excellent contrast for Aß plaques and cerebral amyloid angiopathy. In vivo brain imaging shows that the chemiluminescence signal of ADLumin-1 from 5-month-old transgenic 5xFAD mice is 1.80-fold higher than that from the age-matched wild-type mice. Moreover, we demonstrate that it is feasible to further dually-amplify signal via chemiluminescence resonance energy transfer (DAS-CRET) using two non-conjugated smart probes (ADLumin-1 and CRANAD-3) in solutions, brain homogenates, and in vivo whole brain imaging. Our results show that DAS-CRET can provide a 2.25-fold margin between 5-month-old 5xFAD mice and wild type mice. We believe that our strategy could be extended to other aggregating-prone proteins.


Assuntos
Peptídeos beta-Amiloides/química , Luminescência , Animais , Medições Luminescentes/métodos , Camundongos , Imagem Molecular/métodos , Imagem Óptica/métodos , Agregados Proteicos
6.
Biosens Bioelectron ; 166: 112436, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: covidwho-665846

RESUMO

Our recent experience of the COVID-19 pandemic has highlighted the importance of easy-to-use, quick, cheap, sensitive and selective detection of virus pathogens for the efficient monitoring and treatment of virus diseases. Early detection of viruses provides essential information about possible efficient and targeted treatments, prolongs the therapeutic window and hence reduces morbidity. Graphene is a lightweight, chemically stable and conductive material that can be successfully utilized for the detection of various virus strains. The sensitivity and selectivity of graphene can be enhanced by its functionalization or combination with other materials. Introducing suitable functional groups and/or counterparts in the hybrid structure enables tuning of the optical and electrical properties, which is particularly attractive for rapid and easy-to-use virus detection. In this review, we cover all the different types of graphene-based sensors available for virus detection, including, e.g., photoluminescence and colorimetric sensors, and surface plasmon resonance biosensors. Various strategies of electrochemical detection of viruses based on, e.g., DNA hybridization or antigen-antibody interactions, are also discussed. We summarize the current state-of-the-art applications of graphene-based systems for sensing a variety of viruses, e.g., SARS-CoV-2, influenza, dengue fever, hepatitis C virus, HIV, rotavirus and Zika virus. General principles, mechanisms of action, advantages and drawbacks are presented to provide useful information for the further development and construction of advanced virus biosensors. We highlight that the unique and tunable physicochemical properties of graphene-based nanomaterials make them ideal candidates for engineering and miniaturization of biosensors.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Grafite , Pneumonia Viral/diagnóstico , Vírus/isolamento & purificação , Reações Antígeno-Anticorpo , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/tendências , Técnicas de Laboratório Clínico/instrumentação , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/estatística & dados numéricos , Colorimetria , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , DNA Viral/análise , DNA Viral/genética , Técnicas Eletroquímicas , Desenho de Equipamento , Grafite/química , Humanos , Luminescência , Nanoestruturas/química , Hibridização de Ácido Nucleico , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Pontos Quânticos/química , Análise Espectral Raman , Ressonância de Plasmônio de Superfície , Virologia/métodos , Vírus/genética , Vírus/patogenicidade
7.
Phys Rev Lett ; 125(2): 028102, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32701324

RESUMO

One of the characteristic features of many marine dinoflagellates is their bioluminescence, which lights up nighttime breaking waves or seawater sliced by a ship's prow. While the internal biochemistry of light production by these microorganisms is well established, the manner by which fluid shear or mechanical forces trigger bioluminescence is still poorly understood. We report controlled measurements of the relation between mechanical stress and light production at the single cell level, using high-speed imaging of micropipette-held cells of the marine dinoflagellate Pyrocystis lunula subjected to localized fluid flows or direct indentation. We find a viscoelastic response in which light intensity depends on both the amplitude and rate of deformation, consistent with the action of stretch-activated ion channels. A phenomenological model captures the experimental observations.


Assuntos
Dinoflagelados/fisiologia , Modelos Biológicos , Dinoflagelados/química , Dinoflagelados/ultraestrutura , Canais Iônicos/química , Canais Iônicos/fisiologia , Luminescência , Análise de Célula Única , Estresse Mecânico , Substâncias Viscoelásticas/química
8.
Environ Monit Assess ; 192(8): 484, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32617676

RESUMO

As the application of nanoparticles (NPs) and their release to the environment has increased, it is important to verify their toxicity, with a special emphasis on particle solubilization and the interaction of NP mixtures. In the current study, a model luminescent bacteria, Vibrio fischeri, was employed to test the acute toxicity of individual NPs and their binary mixtures, including metal NPs (ZnNPs, CuNPs) and metal oxide NPs (ZnONPs, CuONPs). The independent action model was used to reflect the synergistic, additive, or antagonistic interactions of binary mixtures of these NPs. The results showed that the median effective concentration (EC50) inhibited the luminescence of V. fischeri were 20.5, 4.1, 11.6, and 118.7 mg L-1 for ZnNPs, CuNPs, ZnONPs, and CuONPs, respectively, suggesting that the toxicity of these NPs to V. fischeri were as the following order: CuNPs > ZnONPs > ZnNPs > CuONPs. The combined effect of NPs were found to be antagonistic for CuNPs-ZnONPs and CuNPs-CuONPs, synergistic for CuONPs-ZnNPs, CuNPs-ZnNPs, and ZnONPs-CuONPs, and additive for ZnNPs-ZnONPs, revealing a complex pattern of possible interactions. The differences of dissolved metal ions partly accounted for the different combined toxicity of binary mixtures of NPs. The findings have important implications for better understanding the true environmental risk of NP mixtures.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Aliivibrio fischeri , Monitoramento Ambiental , Íons , Luminescência
9.
Nat Commun ; 11(1): 3362, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620794

RESUMO

Intrinsically and fully stretchable active-matrix-driven displays are an important element to skin electronics that can be applied to many emerging fields, such as wearable electronics, consumer electronics and biomedical devices. Here, we show for the first time a fully stretchable active-matrix-driven organic light-emitting electrochemical cell array. Briefly, it is comprised of a stretchable light-emitting electrochemical cell array driven by a solution-processed, vertically integrated stretchable organic thin-film transistor active-matrix, which is enabled by the development of chemically-orthogonal and intrinsically stretchable dielectric materials. Our resulting active-matrix-driven organic light-emitting electrochemical cell array can be readily bent, twisted and stretched without affecting its device performance. When mounted on skin, the array can tolerate to repeated cycles at 30% strain. This work demonstrates the feasibility of skin-applicable displays and lays the foundation for further materials development.


Assuntos
Materiais Biomiméticos/química , Elastômeros/química , Transistores Eletrônicos , Dispositivos Eletrônicos Vestíveis , Eletroquímica , Éteres/química , Estudos de Viabilidade , Fluorcarbonetos/química , Luminescência , Teste de Materiais , Ácidos Polimetacrílicos/química , Pele
12.
J Vis Exp ; (160)2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32658181

RESUMO

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers are directly grown on NPSS using catalyst-free atmospheric-pressure chemical vapor deposition (APCVD). By applying nitrogen reactive ion etching (RIE) plasma treatment, defects are introduced into the graphene film to enhance chemical reactivity. During metal-organic chemical vapor deposition (MOCVD) growth of AlN, this N-plasma treated graphene buffer enables AlN quick growth, and coalescence on NPSS is confirmed by cross-sectional scanning electron microscopy (SEM). The high quality of AlN on graphene-NPSS is then evaluated by X-ray rocking curves (XRCs) with narrow (0002) and (10-12) full width at half-maximum (FWHM) as 267.2 arcsec and 503.4 arcsec, respectively. Compared to bare NPSS, AlN growth on graphene-NPSS shows significant reduction of residual stress from 0.87 GPa to 0.25 Gpa, based on Raman measurements. Followed by AlGaN multiple quantum wells (MQWS) growth on graphene-NPSS, AlGaN-based deep ultraviolet light-emitting-diodes (DUV LEDs) are fabricated. The fabricated DUV-LEDs also demonstrate obvious, enhanced luminescence performance. This work provides a new solution for the growth of high quality AlN and fabrication of high performance DUV-LEDs using a shorter process and less costs.


Assuntos
Óxido de Alumínio/química , Grafite/química , Nanoestruturas/química , Semicondutores , Raios Ultravioleta , Compostos de Alumínio/química , Catálise , Gálio/química , Gases/química , Luminescência , Volatilização
14.
PLoS One ; 15(6): e0234645, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555693

RESUMO

Protein tyrosine phosphorylation is key to activation of receptor tyrosine kinases (RTK) that drive development of some cancers. One challenge of RTK-targeted therapy is identification of those tumors that express non-mutated but activated RTKs. Phosphotyrosine (pTyr) RTK levels should be more predictive of the latter than expressed total protein. Western blotting (WB) with a pTyr antibody and enhanced chemiluminescence (ECL) detection is sufficiently sensitive to detect pTyr-RTKs in human tumor homogenates. Presentation of results by comparing WB images, however, is wanting. Here we describe the preparation of a new pTyr-protein standard, pTyr-ALK48-SB (pA), derived from a commercial anaplastic lymphoma kinase (ALK) recombinant fragment, and its use to quantify pTyr-epidermal growth factor receptor (pTyr-EGFR) in commercial A431 cell lysates. Linearity of one-dimensional (1D) WB plots of pA band density versus load as well as its lower level of detection (0.1 ng, 2 fmole) were determined for standardized conditions. Adding pA to two lots of A431 cell lysates with high and low pTyr-EGFR allowed normalization and quantification of the latter by expressing results as density ratios for both 1D and 2D WB. This approach is semi-quantitative because unknown RTKs may be outside the linear range of detection. Semiquantitative ratios are an improvement over comparisons of images without a reference standard and facilitate comparisons between samples.


Assuntos
Quinase do Linfoma Anaplásico/química , Western Blotting/métodos , Medições Luminescentes/normas , Fosfotirosina/química , Linhagem Celular Tumoral , Receptores ErbB/análise , Humanos , Luminescência , Proteínas Recombinantes/química , Padrões de Referência
15.
Proc Biol Sci ; 287(1928): 20192918, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32517614

RESUMO

Counterillumination, the masking of an animal's silhouette with ventral photophores, is found in a number of mesopelagic taxa but is difficult to employ because it requires that the animal match the intensity of downwelling light without seeing its own ventral photophores. It has been proposed that the myctophid, Tarletonbeania crenularis, uses a photophore directed towards the eye, termed an eye-facing photophore, as a reference standard that it adjusts to match downwelling light. The potential use of this mechanism, however, has not been evaluated in other fishes. Here, we use micro-computed tomography, photography and dissection to evaluate the presence/absence of eye-facing photophores in three families of stomiiform fishes. We found that all sampled species with ventral photophores capable of counterillumination possess an eye-facing photophore that is pigmented on the anterior and lateral sides, thus preventing its use as a laterally directed signal, lure or searchlight. The two species that are incapable of counterillumination, Cyclothone obscura and Sigmops bathyphilus, lack an eye-facing photophore. After determining the phylogenetic distribution of eye-facing photophores, we used histology to examine the morphology of the cranial tissue in Argyropelecus aculeatus and determined that light from the eye-facing photophore passes through a transparent layer of tissue, then the lens, and finally strikes the accessory retina. Additionally, eight of the 14 species for which fresh specimens were available had an aphakic gap that aligned with the path of emitted light from the eye-facing photophore, while the remaining six had no aphakic gap. These findings, combined with records of eye-facing photophores from distantly related taxa, strongly suggest that eye-facing photophores serve as a reference for counterillumination in these fishes.


Assuntos
Olho , Peixes/fisiologia , Animais , Luminescência , Visão Ocular
16.
Nat Commun ; 11(1): 2668, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32472057

RESUMO

Electrochemiluminescence (ECL) is a powerful transduction technique with a leading role in the biosensing field due to its high sensitivity and low background signal. Although the intrinsic analytical strength of ECL depends critically on the overall efficiency of the mechanisms of its generation, studies aimed at enhancing the ECL signal have mostly focused on the investigation of materials, either luminophores or coreactants, while fundamental mechanistic studies are relatively scarce. Here, we discover an unexpected but highly efficient mechanistic path for ECL generation close to the electrode surface (signal enhancement, 128%) using an innovative combination of ECL imaging techniques and electrochemical mapping of radical generation. Our findings, which are also supported by quantum chemical calculations and spin trapping methods, led to the identification of a family of alternative branched amine coreactants, which raises the analytical strength of ECL well beyond that of present state-of-the-art immunoassays, thus creating potential ECL applications in ultrasensitive bioanalysis.


Assuntos
Biomarcadores/análise , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletroquímica/métodos , Medições Luminescentes/métodos , Técnicas de Química Analítica , Físico-Química/métodos , Luminescência
17.
J Vis Exp ; (158)2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32364541

RESUMO

In this work, we describe a protocol for a novel application of hyperspectral imaging (HSI) in the analysis of luminescent lanthanide (Ln3+)-based molecular single crystals. As representative example, we chose a single crystal of the heterodinuclear Ln-based complex [TbEu(bpm)(tfaa)6] (bpm=2,2'-bipyrimidine, tfaa- =1,1,1-trifluoroacetylacetonate) exhibiting bright visible emission under UV excitation. HSI is an emerging technique that combines 2-dimensional spatial imaging of a luminescent structure with spectral information from each pixel of the obtained image. Specifically, HSI on single crystals of the [Tb-Eu] complex provided local spectral information unveiling variation of the luminescence intensity at different points along the studied crystals. These changes were attributed to the optical anisotropy present in the crystal, which results from the different molecular packing of Ln3+ ions in each one of the directions of the crystal structure. The HSI herein described is an example of the suitability of such technique for spectro-spatial investigations of molecular materials. Yet, importantly, this protocol can be easily extended for other types of luminescent materials (such as micron-sized molecular crystals, inorganic microparticles, nanoparticles in biological tissues, or labelled cells, among others), opening many possibilities for deeper investigation of structure-property relationships. Ultimately, such investigations will provide knowledge to be leveraged into the engineering of advanced materials for a wide range of applications from bioimaging to technological applications, such as waveguides or optoelectronic devices.


Assuntos
Elementos da Série dos Lantanídeos/química , Imagem Óptica , Fenômenos Ópticos , Anisotropia , Luminescência
19.
Clin Chem Lab Med ; 58(8): 1357-1364, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: covidwho-345901

RESUMO

Objectives Faced with the COVID-19 pandemic and its impact on the availability and quality of both therapeutic and diagnostic methods, the Belgian authorities have decided to launch a procedure for additional evaluation of the performance of serological tests offered for sale on the national territory. This has been proposed with a double aim: (1) an in-depth verification of the analytical and clinical performances presented by the manufacturer and (2) an economy of scale in terms of centralized validation for all the laboratories using the tests subject to evaluation. Methods A retrospective validation study was conducted including the serum of 125 patients in order to determine the analytical and clinical performances of the LIAISON®SARS-CoV-2 from DiaSorin® detecting anti-SARS-CoV-2 IgG and to compare its clinical performance with the enzyme-linked immunosorbent assay (ELISA) test from Euroimmun®, one of the first commercially available tests allowing the detection of anti-SARS-CoV-2 IgA and IgG. Results The performances of the LIAISON®SARS-CoV-2 satisfied all the acceptance criteria and provided "real world" analytical and clinical performances very close to the ones reported by the manufacturer in its insert kit. Comparison between the LIAISON®SARS-CoV-2 and the ELISA method did not reveal any difference between the two techniques in terms of sensitivities and specificities regarding the determination of the IgG. Conclusions This study reports the validation of the LIAISON®SARS-CoV-2 allowing to detect IgG antibodies specifically directed against SARS-CoV-2. The analytical and clinical performances are excellent, and the automation of the test offers important rates, ideal for absorbing an extension of testing.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Pneumonia Viral/diagnóstico , Infecções por Coronavirus/imunologia , Humanos , Limite de Detecção , Luminescência , Medições Luminescentes/métodos , Pandemias , Pneumonia Viral/imunologia , Reprodutibilidade dos Testes , Estudos Retrospectivos
20.
Clin Chem Lab Med ; 58(8): 1357-1364, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32447328

RESUMO

Objectives Faced with the COVID-19 pandemic and its impact on the availability and quality of both therapeutic and diagnostic methods, the Belgian authorities have decided to launch a procedure for additional evaluation of the performance of serological tests offered for sale on the national territory. This has been proposed with a double aim: (1) an in-depth verification of the analytical and clinical performances presented by the manufacturer and (2) an economy of scale in terms of centralized validation for all the laboratories using the tests subject to evaluation. Methods A retrospective validation study was conducted including the serum of 125 patients in order to determine the analytical and clinical performances of the LIAISON®SARS-CoV-2 from DiaSorin® detecting anti-SARS-CoV-2 IgG and to compare its clinical performance with the enzyme-linked immunosorbent assay (ELISA) test from Euroimmun®, one of the first commercially available tests allowing the detection of anti-SARS-CoV-2 IgA and IgG. Results The performances of the LIAISON®SARS-CoV-2 satisfied all the acceptance criteria and provided "real world" analytical and clinical performances very close to the ones reported by the manufacturer in its insert kit. Comparison between the LIAISON®SARS-CoV-2 and the ELISA method did not reveal any difference between the two techniques in terms of sensitivities and specificities regarding the determination of the IgG. Conclusions This study reports the validation of the LIAISON®SARS-CoV-2 allowing to detect IgG antibodies specifically directed against SARS-CoV-2. The analytical and clinical performances are excellent, and the automation of the test offers important rates, ideal for absorbing an extension of testing.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Pneumonia Viral/diagnóstico , Infecções por Coronavirus/imunologia , Humanos , Limite de Detecção , Luminescência , Medições Luminescentes/métodos , Pandemias , Pneumonia Viral/imunologia , Reprodutibilidade dos Testes , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA