26,420 results match your criteria change fluorescence

AIE-based fluorescent boronate probe and its application in peroxynitrite imaging.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Jun 4;261:120044. Epub 2021 Jun 4.

Institute of Environmental Science, Shanxi University, Taiyuan 030006, PR China. Electronic address:

Fluorescent probes have contributed greatly to our understanding of the biological role of peroxynitrite (ONOO). The ONOO fluorescence probe characterized by the arlyboronate received a moderate opening fluorescence response, and the borate-masked probe significantly increased the sensitivity of ONOO. Thus, two simple fluorescent probes (ADB and ANB) with the recognition receptor of phenyl boronate moiety were constructed for the detection of ONOO. Read More

View Article and Full-Text PDF

Fluorescent polymeric nanoparticle for ratiometric temperature sensing allows real-time monitoring in influenza virus-infected cells.

J Colloid Interface Sci 2021 Jun 1;601:825-832. Epub 2021 Jun 1.

Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan. Electronic address:

Temperature is a key indicator of infection and disease, however, it is difficult to measure at a cellular level. Nanoparticles are applied to measure the cellular temperature, and enhancement of the stability and reliability of the signal and higher biocompatibility are demanded. We have developed fluorescent polymeric nanoparticles loaded with temperature-sensitive units (as rhodamine B) and internal reference units (as coumarin) for imaging and ratiometric sensing of the cellular temperature in the physiological range. Read More

View Article and Full-Text PDF

Salvianolic acid B noncovalently interacts with disordered c-Myc: a computational and spectroscopic-based study.

Future Med Chem 2021 Jun 11. Epub 2021 Jun 11.

Department of Medicinal Chemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India.

c-Myc, along with its partner MAX, regulates the expression of several genes, leading to an oncogenic phenotype. The MAX interacting interface of c-Myc is disordered and uncharacterized for small molecule binding. Salvianolic acid B possesses numerous therapeutic properties, including anticancer activity. Read More

View Article and Full-Text PDF

Ratiometric sensing of Zn with a new benzothiazole-based fluorescent sensor and living cell imaging.

Analyst 2021 Jun 11. Epub 2021 Jun 11.

School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.

A new fluorescent probe, 3-(benzo[d]thiazol-2-yl)-5-bromosalicylaldehyde-4N-phenyl thiosemicarbazone (BTT), for ratiometric sensing of Zn2+ ions in methanol/HEPES buffer solution (3 : 2, pH = 7.4) is reported in this paper. The presence of Zn2+ ions yields a significant blue shift in the maximum emission of BTT from 570 nm to 488 nm, accompanied by a clear color change from orange to green. Read More

View Article and Full-Text PDF

Tannic acid-fortified zein-pectin nanoparticles: Stability, properties, antioxidant activity, and in vitro digestion.

Food Res Int 2021 Jul 19;145:110425. Epub 2021 May 19.

Food Science School, Guangdong Pharmaceutical University, Zhongshan, Guangdong Province 528458, China. Electronic address:

Tannic acid was loaded into zein nanoparticles using antisolvent precipitation and then these particles were coated by anionic pectin using electrostatic deposition. The resulting core-shell nanoparticles were near spherical and had an average diameter of 166 nm, a particle yield of 95%, a tannic acid content of 5.4%, and a tannic acid loading efficiency of 89%. Read More

View Article and Full-Text PDF

Fluorene Based Ferric Complex as Colorimetric and Fluorometric Probe for Highly Selective Detection of CN and S Anions.

J Fluoresc 2021 Jun 10. Epub 2021 Jun 10.

Department of Chemistry, Faculty of Arts and Science, Manisa Celal Bayar University, Yunus Emre, 45140, Manisa, Turkey.

A series of new chemosensor molecules bearing benzothiazole-, quinoline- and phthalazine-functionalized fluorene derivatives were synthesized and their complexation behaviors with Fe and Sn ions were investigated. The sensing abilities of their complexes towards both cyanide and sulfide anions were investigated by colorimetric and fluorometric techniques in detail. The sensing mechanism was investigated by Job's and Scatchard plots evaluations, and also absorption/fluorescence titration experiments. Read More

View Article and Full-Text PDF

Optimizing protein V untranslated region sequence in M13 phage for increased production of single-stranded DNA for origami.

Nucleic Acids Res 2021 Jun 10. Epub 2021 Jun 10.

Department of Chemical & Biological Engineering, Korea University, Seoul 02841, Republic of Korea.

DNA origami requires long scaffold DNA to be aligned with the guidance of short staple DNA strands. Scaffold DNA is produced in Escherichia coli as a form of the M13 bacteriophage by rolling circle amplification (RCA). This study shows that RCA can be reconfigured by reducing phage protein V (pV) expression, improving the production throughput of scaffold DNA by at least 5. Read More

View Article and Full-Text PDF

Single Cell RNA-Seq Analysis Identifies Differentially Expressed Genes of Treg Cell in Early Treatment-Naive Rheumatoid Arthritis By Arsenic Trioxide.

Front Pharmacol 2021 24;12:656124. Epub 2021 May 24.

Department of Rheumatology and Immunology, First Affiliated Hospital of Harbin Medical University, Harbin, China.

Early treatment-naïve rheumatoid arthritis (RA) has defective regulatory T (Treg) cells and increased inflammation response. In this study, we aim to illustrate the regulation of Treg cells in pathogenesis of early rheumatoid arthritis by arsenic trioxide (AsO). We studied the effects of AsO on gene expression in early treatment-naïve RA Treg cells with single cell RNA-seq (scRNA-seq). Read More

View Article and Full-Text PDF

DEK-AFF2 fusion-associated papillary squamous cell carcinoma of the sinonasal tract: clinicopathologic characterization of seven cases with deceptively bland morphology.

Mod Pathol 2021 Jun 9. Epub 2021 Jun 9.

Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.

A novel DEK-AFF2 fusion has been recently identified in four cases of basaloid to nonkeratinizing squamous cell carcinoma (SCC) in the sinonasal tract and middle ear with high-grade morphology. The exceptional response to immune checkpoint inhibitor in the first reported case highlights the potential clinical importance of identifying tumors with DEK-AFF2 fusions. We herein reported the first series of seven cases of DEK-AFF2 fusion-associated sinonasal SCC with deceptively bland morphology, including four cases of low-grade papillary Schneiderian carcinoma, which is a recently described tumor type with unknown molecular underpinnings. Read More

View Article and Full-Text PDF

CircC16orf62 promotes hepatocellular carcinoma progression through the miR-138-5p/PTK2/AKT axis.

Cell Death Dis 2021 Jun 9;12(6):597. Epub 2021 Jun 9.

Department of Interventional Radiology, the Affiliated Hospital of Guizhou Medical University, Guiyang, 550004, P.R. China.

Circular RNA (circRNAs) functions vital in the pathogenesis and progression of hepatocellular carcinoma (HCC). However, the expressions and functions of certain circRNAs on metastasis and proliferation of that cancer is still unclear. Bioinformation analysis and qRT-PCR indicated that CircC16orf62 was prominent upregulated in HCC of which the expression level was positively associated to cancer's malignant progression. Read More

View Article and Full-Text PDF

Integrin intra-heterodimer affinity inversely correlates with integrin activatability.

Cell Rep 2021 Jun;35(10):109230

Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06520, USA. Electronic address:

Integrins are heterodimeric cell surface receptors composed of an α and β subunit that mediate cell adhesion to extracellular matrix proteins such as fibronectin. We previously studied integrin α5β1 activation during zebrafish somitogenesis, and in the present study, we characterize the integrin αV fibronectin receptors. Integrins are activated via a conformational change, and we perform single-molecule biophysical measurements of both integrin activation via fluorescence resonance energy transfer (FRET)-fluorescence lifetime imaging microscopy (FLIM) and integrin intra-heterodimer stability via fluorescence cross-correlation spectroscopy (FCCS) in living embryos. Read More

View Article and Full-Text PDF

Fluorescent Magnesium Hydroxide Nanosheet Bandages with Tailored Properties for Biocompatible Antimicrobial Wound Dressings and pH Monitoring.

ACS Appl Mater Interfaces 2021 Jun 9. Epub 2021 Jun 9.

Advanced Manufacturing and Fabrication, School of Engineering, RMIT University, Melbourne, VIC 3000, Australia.

Magnesium hydroxide (Mg(OH)) is hailed as a cheap and biocompatible material with antimicrobial potential; however, research aimed at instilling additional properties and functionality to this material is scarce. In this work, we synthesized novel, fluorescent magnesium hydroxide nanosheets (Mg(OH)-NS) with a morphology that closely resembles that of graphene oxide. These multifunctional nanosheets were employed as a potent antimicrobial agent against several medically relevant bacterial and fungal species, particularly on solid surfaces. Read More

View Article and Full-Text PDF

Layer-by-Layer Assembled Nanostructured Lipid Carriers for CD-44 Receptor-Based Targeting in HIV-Infected Macrophages for Efficient HIV-1 Inhibition.

AAPS PharmSciTech 2021 Jun 7;22(5):171. Epub 2021 Jun 7.

Centre for Novel Drug Delivery Systems, Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, N. P. Marg, Matunga (E), Mumbai, 400 019, India.

Macrophages act as a cellular reservoir in HIV infection. Elimination of HIV from macrophages has been an unfulfilled dream due to the failure of drugs to reach them. To address this, we developed CD44 receptor-targeted, novel hyaluronic acid (HA)-coated nanostructured lipid carriers (NLCs) of efavirenz via washless layer-by-layer (LbL) assembly of HA and polyallylamine hydrochloride (PAH). Read More

View Article and Full-Text PDF

Critical angle reflection imaging for quantification of molecular interactions on glass surface.

Nat Commun 2021 06 7;12(1):3365. Epub 2021 Jun 7.

Biodesign Center for Biosensors and Bioelectronics, Arizona State University, Tempe, AZ, USA.

Quantification of molecular interactions on a surface is typically achieved via label-free techniques such as surface plasmon resonance (SPR). The sensitivity of SPR originates from the characteristic that the SPR angle is sensitive to the surface refractive index change. Analogously, in another interfacial optical phenomenon, total internal reflection, the critical angle is also refractive index dependent. Read More

View Article and Full-Text PDF

Probing the interaction of fisetin with human serum transferrin via spectroscopic and molecular docking approaches.

J Biomol Struct Dyn 2021 Jun 7:1-7. Epub 2021 Jun 7.

Department of Electricity, Solid Physics and Biophysics, Faculty of Physics, University of Bucharest, Romania.

The binding of fisetin to human serum transferrin (HST) was investigated by spectroscopic (steady-state fluorescence, synchronous fluorescence, Förster resonance energy transfer) and molecular docking approaches. HST fluorescence is quenched by fisetin by a static process. The binding takes place with a moderate affinity and it is driven by hydrogen bonding and van der Waals forces. Read More

View Article and Full-Text PDF

Protection of human γD-crystallin protein from ultraviolet C-induced aggregation by ortho-vanillin.

Spectrochim Acta A Mol Biomol Spectrosc 2021 May 26;261:120023. Epub 2021 May 26.

Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan. Electronic address:

Cataract is known as one of the leading causes of vision impairment worldwide. While the detailed mechanism of cataratogenesis remains unclear, cataract is believed to be correlated with the aggregation and/or misfolding of human ocular lens proteins called crystallins. A 173-residue structural protein human γD-crystallin is a major γ-crystallin protein in the human eye lens and associated with the development of juvenile and mature-onset cataracts. Read More

View Article and Full-Text PDF

Monitoring Mitochondrial Function in Mouse Embryonic Stem Cells (mESCs).

Methods Mol Biol 2021 ;2310:47-56

Department of Life Sciences, University of Coimbra, Coimbra, Portugal.

Mouse embryonic stem cells (mESCs) can be grown in culture, recapitulating the different states of pluripotency of their in vivo counterparts, with notably different metabolic profiles. mESCs in a naïve pluripotent state present an ambivalent metabolism, using both glycolysis and oxidative phosphorylation as energy sources. Here, we describe a method to evaluate the oxidative function of naïve mESCs using the Seahorse Extracellular Flux Analyzer coupled to flow cytometry analysis of mitochondrial transmembrane potential using the TMRM fluorescence probe, thus assessing both oxygen consumption and mitochondrial membrane potential. Read More

View Article and Full-Text PDF
January 2021

Natural Kaolin-Based Ni Catalysts for CO Methanation: On the Effect of Ce Enhancement and Microwave-Assisted Hydrothermal Synthesis.

ACS Omega 2021 Jun 18;6(21):13779-13794. Epub 2021 May 18.

Department of Chemical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom 73170, Thailand.

Natural kaolin-based Ni catalysts have been developed for low-temperature CO methanation. The catalysts were prepared via a one-step co-impregnation of Ni and Ce onto a natural kaolin-derived metakaolin using a microwave-assisted hydrothermal method as an acid-/base-free synthesis method. The influences of microwave irradiation and Ce promotion on the catalytic enhancement including the CO conversion, CH selectivity, and CH yield were experimentally investigated by a catalytic test of as-prepared catalysts in a fixed-bed tubular reactor. Read More

View Article and Full-Text PDF

A new pentacyclic pyrylium fluorescent probe that responds to pH imbalance during apoptosis.

Chem Sci 2020 Jul 17;11(47):12695-12700. Epub 2020 Jul 17.

Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST) Thiruvananthapuram 695 019 India

Efficient fluorophores with easy synthetic routes and fast responses are of great importance in clinical diagnostics. Herein, we report a new, rigid pentacyclic pyrylium fluorophore, , synthesised in a single step by a modified Vilsmeier-Haack reaction. Insights into the reaction mechanism facilitated a new reaction protocol for the efficient synthesis of which upon demethylation resulted in a "turn-on" pH sensor, . Read More

View Article and Full-Text PDF

Cancer cell discrimination and dynamic viability monitoring through wash-free bioimaging using AIEgens.

Chem Sci 2020 Apr 30;11(29):7676-7684. Epub 2020 Apr 30.

Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute for Advanced Study, Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong 999077 China

Cancer cell discrimination and cellular viability monitoring are closely related to human health. A universal and convenient fluorescence system with a dual function of wide-spectrum cancer cell discrimination and dynamic cellular viability monitoring is desperately needed, and is still extremely challenging. Herein we present a series of aggregation-induced emission luminogens (AIEgens) (denoted as IVP) which can allow accurate discrimination between cancer and normal cells and dynamic monitoring of cellular viability through mitochondria-nucleolus migration. Read More

View Article and Full-Text PDF

Excitation-Scanning Hyperspectral Imaging as a Means to Discriminate Various Tissues Types.

Proc SPIE Int Soc Opt Eng 2017 Jan-Feb;10068. Epub 2017 Feb 16.

Chemical & Biomolecular Engineering, University of South Alabama.

Little is currently known about the fluorescence excitation spectra of disparate tissues and how these spectra change with pathological state. Current imaging diagnostic techniques have limited capacity to investigate fluorescence excitation spectral characteristics. This study utilized excitation-scanning hyperspectral imaging to perform a comprehensive assessment of fluorescence spectral signatures of various tissues. Read More

View Article and Full-Text PDF
February 2017

Combined liver-kidney transplantation with positive crossmatch: Role of delayed kidney transplantation.

Surgery 2021 Jun 3. Epub 2021 Jun 3.

Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN. Electronic address:

Background: Positive crossmatch (XM+) combined liver-kidney transplantation due to preformed donor-specific human leukocyte antigen antibodies has produced mixed results. We sought to understand the role of delayed kidney transplant approach in XM+ combined liver-kidney transplantations.

Methods: XM+ combined liver-kidney transplantations were retrospectively reviewed. Read More

View Article and Full-Text PDF

Fluorescent paper-based DNA sensor using pyrrolidinyl peptide nucleic acids for hepatitis C virus detection.

Biosens Bioelectron 2021 May 29;189:113381. Epub 2021 May 29.

Electrochemistry and Optical Spectroscopy Center of Excellence, Department of Chemistry, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand. Electronic address:

A novel fluorescent paper-based DNA sensor employing a highly specific pyrrolidinyl peptide nucleic acid (acpcPNA) probe was developed for the sensitive and selective detection of hepatitis C virus (HCV). The acpcPNA was covalently immobilized onto partially oxidized cellulose paper via reductive alkylation between the amine and the aldehyde groups. The fluorescence-based detection was performed by monitoring the fluorescence signal response of a fluorescent dye that selectively binds to the single-strand region of the DNA target over the PNA probe employing a custom-made portable fluorescent camera gadget in combination with a smartphone camera. Read More

View Article and Full-Text PDF

Ratiometric Fluorescent Probe for Tetracycline Detection Based on the Waste Printing Paper.

Luminescence 2021 Jun 5. Epub 2021 Jun 5.

Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China.

Tetracycline (TC) represents a broad-spectrum antibiotic to treat bacterial infections. In this study, a ratiometric fluorescence (FL) probe was developed for the detection of TC in water samples by using waste printing paper extract as a FL indicator. In this ratiometric probe, the emission of printing paper extract at 436 nm gradually decreased and the emission of mixed solution at 538 nm significantly increased with the sequential addition of TC upon being excited at 390 nm, coupled with a remarkable FL color change from bright blue to faint yellow. Read More

View Article and Full-Text PDF

Naturally acquired SARS-CoV-2 immunity persists for up to 11 months following infection.

J Infect Dis 2021 Jun 5. Epub 2021 Jun 5.

National Institutes of Health (NIH), Clinical Center, Department of Transfusion Medicine, Bethesda, MD 20892, USA.

Background: Characterizing the kinetics of the antibody response to SARS-CoV-2 is of critical importance to developing strategies that may mitigate the public health burden of COVID-19. We conducted a prospective, longitudinal analysis of COVID-19 convalescent plasma (CCP) donors at multiple time points over an 11-month period in order to determine how circulating antibody levels change over time following natural infection.

Methods: From April 2020 to February 2021, we enrolled 228 donors. Read More

View Article and Full-Text PDF

Highly selective fluorescence probe with peptide backbone for imaging mercury ions in living cells based on aggregation-induced emission effect.

J Hazard Mater 2021 08 26;415:125712. Epub 2021 Mar 26.

Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, PR China; Collaborative Innovation Center of Chemistry for Life Sciences, School of Life Sciences, University of Science and Technology of China, Hefei 230027, PR China. Electronic address:

Mercury is an anthropogenic toxic heavy metal found in the environment. It is highly desirable to develop a fluorescence probe that can selectively and sensitively detect mercury ions using a turn-on response. This paper reports the successful development of a peptide fluorescence probe, TP-2 (TPE-Trp-Pro-Gln-His-Glu-NH), which uses aggregation-induced emission effects and high selectivity to detect Hg. Read More

View Article and Full-Text PDF

Biochar induced changes of soil dissolved organic matter: The release and adsorption of dissolved organic matter by biochar and soil.

Sci Total Environ 2021 Aug 14;783:147091. Epub 2021 Apr 14.

Institute of Resources and Environmental Engineering, Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes, Shanxi University, Taiyuan 030006, China. Electronic address:

Dissolved organic matter (DOM) is an important organic matter fraction that affects many biological and chemical processes in soil. Biochar can change soil DOM while the effects were paradoxical, and contributions of biochar to soil DOM was not clear yet. In this study, excitation-emission matrix (EEM) fluorescence spectroscopy was applied to determine the biochar-induced changes of DOM composition. Read More

View Article and Full-Text PDF

Fluorescence Anisotropy-Based Assay for Characterization of Ligand Binding Dynamics to GPCRs: The Case of Cy3B-Labeled Ligands Binding to MC Receptors in Budded Baculoviruses.

Methods Mol Biol 2021 ;2268:119-136

Institute of Chemistry, University of Tartu, Tartu, Estonia.

During the past decade, fluorescence methods have become valuable tools for characterizing ligand binding to G protein-coupled receptors (GPCRs). However, only a few of the assays enable studying wild-type receptors and monitor the ligand binding in real time. One of the approaches that is inherently suitable for this purpose is the fluorescence anisotropy (FA) assay. Read More

View Article and Full-Text PDF
January 2021

Top-emitting thermally activated delayed fluorescence organic light-emitting devices with weak light-matter coupling.

Light Sci Appl 2021 Jun 3;10(1):116. Epub 2021 Jun 3.

Center of Super-Diamond and Advanced Films (COSDAF) and Department of Chemistry, City University of Hong Kong, 999077, Hong Kong SAR, China.

Resonance interaction between a molecular transition and a confined electromagnetic field can lead to weak or strong light-matter coupling. Considering the substantial exciton-phonon coupling in thermally activated delayed fluorescence (TADF) materials, it is thus interesting to explore whether weak light-matter coupling can be used to redistribute optical density of states and to change the rate of radiative decay. Here, we demonstrate that the emission distribution of TADF emitters can be reshaped and narrowed in a top-emitting organic light-emitting device (OLED) with a weakly coupled microcavity. Read More

View Article and Full-Text PDF

Mutations Alter the Subcellular Localization of BRCA1 .

Anticancer Res 2021 Jun;41(6):2953-2962

Department of Biochemistry and Molecular Biology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece.

Background/aim: Numerous missense mutations have been determined in the BRCT domain of the BRCA1 gene, affecting localization and interaction of BRCA1 with other proteins.

Materials And Methods: We examined whether the M1775K and V1809F mutations in the BRCT domain affect BRCA1 cellular localization. Cells were transfected with pEGFP-C3-BRCA1 and detected by fluorescence microscopy. Read More

View Article and Full-Text PDF