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In this paper, we propose a fluorescence-lifetime imaging microscopy (FLIM) multiplexing system based on the fluorogen-activating protein FAST. This genetically encoded fluorescent labeling platform employs FAST mutants that activate the same fluorogen but provide different fluorescence lifetimes for each specific protein-dye pair. All the proposed probes with varying lifetimes possess nearly identical and the smallest-in-class size, along with quite similar steady-state optical properties. In live mammalian cells, we target these chemogenetic tags to two intracellular structures simultaneously, where their fluorescence signals are clearly distinguished by FLIM. Due to the unique structure of certain fluorogens under study, their complexes with FAST mutants display a monophasic fluorescence decay, which may facilitate enhanced multiplexing efficiency by reducing signal cross-talks and providing optimal prerequisites for signal separation upon co-localized and/or spatially overlapped labeling. A genetically encoded labeling system uses smallest-in-class fluorogen-activating protein tags for time-resolved fluorescence multiplexed cellular imaging, offering monoexponential decay and potential for sophisticated fluorescence lifetime analysis. [ABSTRACT FROM AUTHOR]

When approving plant protection products, exposure data are required for risk analysis. Exposure data can be collected for various exposure pathways, such as dermal, inhalation or ground sediment. For measuring exposures, pyranine, a fluorescent dye, and a collector can be used. However, the choice of collector material depends on the specific exposure pathway. This study aims to determine the most suitable collector, in combination with the tracer pyranine, for recording exposure through different pathways in practical trials. Seven different collectors (Tyvek®, labels, plastic patches, paper patches, nylon filters, fibreglass filters, petri dishes) were subjected to laboratory and field tests to assess various quality parameters. Blank values, recovery rates, storability, and fluorescence degradation under UV-radiation were measured. Based on the results, a matrix was created summarizing which collector might be best suited to capture each exposure pathway. Almost all collectors demonstrated high recovery rates (Tyvek® 100%; labels 100%; plastic patches 100%; paper patches 100%; nylon filters 95%; fiberglass filters 60.9%) as well as good storability. Furthermore, all plastic-based collectors (labels, Tyvek®, plastic patches, petri dishes) showed a very good recovery rate above 95% when exposed to UV-radiation. However, nylon filters were not suitable for utilization under field conditions due to the rapid degradation of fluorescence under UV-radiation (recovery rate: 20–56%). Nevertheless, nylon filters showed stable recoveries under protected conditions and can be used to assess inhalation exposures under these conditions. Fibreglass filters, with recovery rates of 84–86%, were well-suited for testing inhalative exposures outdoors when a correction factor was applied. Tyvek® was the most suitable material for detecting total dermal exposure under field conditions. This is due to its quality characteristics and availability in a variety of sizes. Finally, petri dishes were ideal for collecting ground sediments. [ABSTRACT FROM AUTHOR]

Daylight fluorescent pigments with their intense color effects have attracted great interest among artists since their market launch in the mid-twentieth century. Since then they have been widely used in the visual arts. The pigments are mainly compositions of organic fluorescent dyes and optical brighteners diluted in an insoluble resin. Due to the susceptibility of the dyes to visible and UV radiation, their lightfastness is comparatively low. This paper presents a comprehensive study of the color and fluorescence changes of daylight fluorescent paints upon exposure in visible light and ultraviolet radiation conducted on mock-ups of commercial daylight fluorescent pigments. The different aging characteristics of the pigments depend on the color tone. They were recorded by means of photographic and colorimetric documentation. In addition, Raman spectroscopy was used to identify the main dyes of the various pigments, even in the complex system of paints, consisting of primer, binder, resin and dyes, and to determine their degradation during aging. Fluorescence spectroscopy revealed that the change in fluorescent color may not only be due to the decrease in dye concentration, but also to the transformation of the original dyes into other fluorescent compounds during light aging. Finally, this paper provides recommendations for the presentation of artworks containing daylight fluorescent pigments. [ABSTRACT FROM AUTHOR]

The solvatochromic fluorophore Nile Red, 9-diethylamino-5H-benzo[a]phenoxazine-5-one, is one of the most commonly used stains to enhance contrast of lipid-rich areas of microscopic biosamples. Quite surprisingly, relatively little is known about the spectrally-resolved two-photon absorption (2PA) properties of this dye despite its promising features for two-photon microscopy of biological matter. For this reason, the two-photon solvatochromism of Nile Red still remains an uncharted territory as well. Also, no study has yet reported on how electron-withdrawing substituents attached to the Nile Red backbone affect its solvatochromic properties and two-photon brightness. In this paper, we demonstrate how solvent polarity influences the one- and two-photon absorption spectra of Nile Red as well as its fluorescence parameters, and we present new analogues that contain –CF3, –F and –Br substituents on its eastern side. Two-photon excited fluorescence experiments in a broad spectral range (780–1240 nm) and electronic structure calculations show that both the nature and location of the substituent have particular influence on the strength of 2PA, peaking in all cases at approx. 860 and 1050 nm. 2PA cross sections are higher at 1050 nm than at 860 nm, which suggests that Nile Red and its analogues are best suited for two-photon imaging employing excitation in the NIR-II optical transparency window of biological tissues. [ABSTRACT FROM AUTHOR]

Chirality plays a pivotal role in drugs, agrochemicals and food additives et al. The enantiomers of a chiral molecule often show huge difference in bioactivity, metabolism, and toxicity et al. thereby, the recognition of chiral molecules shows an increasingly important priority. In this paper, a novel method for chiral fluorescence recognition based on anthracene fluorescent dyes (AD) ⊂ water-soluble pillar[5] arene containing phosphonic acid group (PWP[5]) is developed. The AD as guest molecule can complex with PWP [5] to form 1:1 AD ⊂ PWP[5] assembly, and this assembly can be further used as a fluorescent probe to identify D/L-phenylalanine and D/L-phenylalaninol by fluorescent titration. The fluorescence intensity of the assembly was significantly reduced for D-phenylalanine and D-phenylalaninol, while L-phenylalanine or L-phenylalaninol was added to AD ⊂ PWP[5] assembly, the fluorescence intensity of the assembly almost unchanged. Hence, the chiral recognition based on assembly between the achiral fused ring fluorescent dye and achiral PWP[5] was developed. [ABSTRACT FROM AUTHOR]

The detection of cracks in spot welding is a major issue especially online. This paper deals with this topic using acoustic emission monitoring. It proposes an approach based on Shannon entropy with a novel criterion that allows increasing the detection sensitivity. A data-based model is built, coded, and then applied on acoustic emission signals. The obtained crack detection results are satisfactory. The cracks are revealed using fluorescent dye penetrant, which enables validating the method. A flowchart of whole the proposed approach is described so that practitioners can benefit from the authors experience, towards successful implementation in laboratory as well as in production line. The current approach is applied on resistance spot welding as a case of study, but it could be applicable in nonstationary environment such as other kinds of spot welding, and more hopefully for other manufacturing processes. [ABSTRACT FROM AUTHOR]

Despite significant progress in understanding of dye aggregation, there are still processes that need to be further explored and which can significantly affect aggregation. In this work it was shown that the aggregation of dyes is influenced not only by dye concentration, but also by solvent polarity. It was found that nature, positions and number of fluorescent peaks may be controlled by simultaneous varying of both water fraction and dye concentration. This effect is most pronounced for molecular rotors, which aggregates' geometry may be stabilized in different separate states depending on the aggregation degree. The concentration effect plays a significant role in dye aggregation and should be considered in new studies in order to prevent misinterpretation or to obtain new results in fields of molecular sensing or fine-tuning of fluorescence color. In this paper aggregation caused spectral changes are discussed in line with the dye structure preorganization as the strategy for the fine tuning of practically valuable spectral characteristics. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is an infectious disease caused by the bacteria Mycobacterium tuberculosis. It primarily affects the lungs, but it can also affect other parts of the body. TB remains one of the leading causes of death in developing countries, and its recent resurgences in both developed and developing countries warrant global attention. The number of deaths due to TB is very high (as per the WHO report, 1.5 million died in 2013), although most are preventable if diagnosed early and treated. There are many tools for TB detection, but the most widely used one is sputum smear microscopy. It is done manually and is often time consuming; a laboratory technician is expected to spend at least 15 min per slide, limiting the number of slides that can be screened. Many countries, including India, have a dearth of properly trained technicians, and they often fail to detect TB cases due to the stress of a heavy workload. Automatic methods are generally considered as a solution to this problem. Attempts have been made to develop automatic approaches to identify TB bacteria from microscopic sputum smear images. In this paper, we provide a review of automatic methods based on image processing techniques published between 1998 and 2014. The review shows that the accuracy of algorithms for the automatic detection of TB increased significantly over the years and gladly acknowledges that commercial products based on published works also started appearing in the market. This review could be useful to researchers and practitioners working in the field of TB automation, providing a comprehensive and accessible overview of methods of this field of research. [ABSTRACT FROM AUTHOR]

In recent decades, advanced powder metallurgy techniques have been extensively modified to prepare various superalloys. Modern powder metallurgical methods like gas atomization are playing a vital role in giving unique properties, and texture to the superalloys. In the present paper, we have used gas atomized super duplex stainless steel (GASDSS) powders as a modifier to determine the toxic dyes like Rhodamine B (Rh B). The main advantage of using gas-atomized SDSS powders is due to their high surface area, spherical shape, and unique composition. Most of its parental composition metals belong to d-block elements in a periodic table and these elements are known for their excellent electrochemical properties. Rh B is a fluorescent dye used as a stain and biomarker and it is carcinogenic in nature. Hence, we have fabricated the gas-atomized super duplex stainless steel modified carbon paste electrode (GASDSS-MCPE) to determine the electrochemical reaction of Rh B dye using cyclic voltammetry (CV). After optimizing the electrochemical studies, we noticed 6 mg GASDSS-MCPE has depicted a maximum current response compared to other electrodes. In the case of bare carbon paste electrode (BCPE) and 6 mg GASDSS-MCPE, the active surface areas were found to be 0.302 and 0.761 cm2 respectively. We have also determined the limit of detection (LOD) and limit of quantification (LOQ) for the fabricated 6 mg GASDSS-MCPE and it was found to be 0.378 µM and 1.260 µM respectively. [ABSTRACT FROM AUTHOR]

Through a facile two-step synthetic procedure, three metal-free organic dyes having D-π-A kind of structure, belonging to chalcone family have been designed, produced and anchored on one dimensional cadmium sulfide nanowires (1D CdS NWs) to serve as a light energy harvester through dye-sensitized solar cells (DSSC) assembly. In order to anchor dye on CdS NWs nano-network, solution chemistry has been used in an easy and effective manner. The sensitizing capability of synthesized materials has been evaluated using optical and electrochemical studies, density functional theory (DFT) simulations, and photovoltaic performances. In line with a detailed analysis of fabricated Dye sensitized solar cells containing T4PC a photovoltaic efficiency yields 4.35 times (0.487%) more than that of bare CdS NWs (0.112%), while the other devices having T3PC and T2PC have shown 3.0 (0.338%) and 2.40 (0.273%) times greater photovoltaic efficiencies, respectively under standard light illumination. The obtained results offer solid evidence in favour of boosting external quantum efficiency (EQE) and reflect good agreement with the optical studies. [ABSTRACT FROM AUTHOR]

In this paper, g-C3N4/SnO2:Sb composite photocatalysts were fabricated by in situ loading Sb-doped SnO2 (SnO2:Sb) nanoparticles on graphitic carbon nitride (g-C3N4) nanosheets via a facile hydrothermal method. The synthesized g-C3N4/SnO2:Sb composites delivered enhanced visible light photocatalytic performance for degradation of rhodamine B in comparison with g-C3N4/SnO2 composites without doping Sb. Various techniques including XRD, SEM, TEM, FTIR, XPS, PL and electrochemical method were employed to demonstrate the successful fabrication of g-C3N4/SnO2:Sb composite and to investigate the enhanced mechanism of photocatalytic activity. The improvement of visible light absorption and the promotion of separation efficiency and interfacial transfer of photogenerated carriers induced by Sb doping were responsible for the enhancement of photocatalytic activity. This study provides a simple and convenient method to synthesize a visible light responsive catalyst with promising performance for the potential application in environmental protection. [ABSTRACT FROM AUTHOR]

Confirmatory identification of dyes in the physical pieces of evidence, such as hair and fabric, is critically important in forensics. This information can be used to demonstrate the link between a person of interest and a crime scene. High performance liquid chromatography is broadly used for dye analysis. However, this technique is destructive and laborious. This problem can be overcome by near-Infrared excitation Raman spectroscopy (NIeRS), non-invasive and non-destructive technique that can be used to determine chemical structure of highly fluorescent dyes. Analyzed fabric materials often possess body fluid stains, which may obscure the accuracy of NIeRS-based identification of dyes. In this study, we investigate the extent to which fabric contamination with body fluids can alter the accuracy of NIeRS. Our results showed that NIeRS coupled with partial-least squared discriminant analysis (PLS-DA) enabled on average 97.6% accurate identification of dyes on fabric contaminated with dry blood, urine and semen. We also found that NIeRS could be used to identify blood, urine and semen on such fabric with 99.4% accuracy. Furthermore, NIeRS could be used to differentiate between wet and dry blood, as well as reveal the presence of blood on washed fabric. These results indicate that NIeRS coupled with PLS-DA could be used as a robust and reliable analytical approach in forensic analysis of fabric. [ABSTRACT FROM AUTHOR]

Herein, a novel fluorescence probe Fla-DNP based on flavonol has been designed and synthesized for rapid, specific detection of H2S. With the addition of H2S, Fla-DNP triggered thiolysis and released Fla displaying the "turn-on" fluorescence response at 566 nm, which is consistent with the reaction site predicted by calculating Electrostatic potential and ADCH charges. As an easily available H2S probe, Fla-DNP has the advantages of high selectivity, anti-interference, low detection limit (0.834 μM), short response time (6 min), and large Stokes shift (124 nm). The sensing mechanism of H2S was determined by HRMS analysis and DFT calculation. Moreover, Fla-DNP processes a wide range of multiple applications, including the detection of H2S in environmental water samples with good recovery rates ranging from 89.6% to 102.0%, as well as tracking the production of H2S during food spoilage. Meanwhile, the probe exhibits superior biocompatibility and can not only be available used for H2S detection in living cells but be further designed as an H2S-activated CO photoreleaser, based on which it can be developed as a targeted anti-cancer drug. A novel fluorescence probe Fla-DNP was synthesized utilizing 4-dimethylaminobenzoxanthone fluorescent dye (Fla) as the fluorophore, 2, 4-dinitrobenzenether group (DNP) as the recognition group, which can rapidly respond to H2S with high selectivity, anti-interference, low detection limit (0.834 μM), short response time (6 min), and large Stokes shift (124 nm) characteristics. The practical applications of Fla-DNP were further explored in water, foodstuffs samples and living cells. It is reflected that Fla-DNP can not only track H2S in complex environment water, but also can detect H2S produced during foodstuffs spoilage to monitor food freshness. More importantly, Fla-DNP can be available used for H2S detection in living cells and utilize the properties of the photoinduced release of CO from flavonols to be designed as a bifunctional platform for H2S detection and CO release. It is demonstrated that H2S-activated CO photoreleaser Fla-DNP has promise for development as an anti-cancer drug. [ABSTRACT FROM AUTHOR]

The interest in the development of non-contact temperature sensors for particle image velocimetry (PIV) is continuously growing. The integration of thermochromic tracers in PIV represents a critical step forward in experimental fluid mechanics, which would enable detailed full-field analysis of thermal and environmental flows. In this paper, interpenetrated polymer networks (IPN) PNIPAAm/alginate loaded with Nile Red (NR) fluorescent dye are used to develop beads for simultaneous non-contact temperature sensing and flow tracing in fluids. The novel IPN beads are coated with chitosan to properly modulate particle permeability in water. The thermochromic response of the fluorescent tracers is studied through fluorescence spectroscopy, evidencing an increase in the NR fluorescence emission up to twenty times above the lower critical solution temperature of PNIPAAm. These findings confirm the potential of fluorescent chitosan-coated PNIPAAm/alginate beads for in situ temperature in PIV. [ABSTRACT FROM AUTHOR]

The use of eosin methylene blue according to Giemsa as photosensitizer is presented for the first time in this paper. The present study evaluated the potential application of chlorophyllin sodium copper salt (CuChlNa) and eosin methylene blue according to Giemsa (EMB) as antimicrobial photosensitizers (aPS) for photodynamic inactivation (PDI) of Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacteria. The experiments were performed using S. aureus stain ATCC 25923 and E. coli ATCC 25922 in which five aPS concentrations (0.0, 1.0, 2.5, 5.0, 10.0, and 20.0 μM for S. aureus and 0.0, 5.0, 10.0, 20.0, 40.0, and 50.0 μM for E. coli) were prepared and added in 2 mL of a saline solution containing the bacterial inoculum. After aPS incubation, the samples were divided into two groups, one kept in the dark and another submitted to the illumination. Then, the bacterial inactivation was determined 18 h after the incubation at 37 °C by counting the colony-forming units (CFU). The results revealed that both EMB and CuChlNa can be used as aPS for the photoinactivation of S. aureus, while only EMB was able to photoinactivate E. coli. Nevertheless, a more complex experimental setup was needed for photoinactivation of E. coli. The data showed that EMB and CuChlNa presented similar photoinactivation effects on S. aureus, in which bacterial growth was completely inhibited at photosensitizer (PS) concentrations over 5 μM, when samples were previously incubated for 30 min and irradiated by a light dose of 30 J cm-2 as a result of an illumination of 1 h at 8.3 mW cm-2 by using a red light at 625 nm with a 1 cm beam diameter and output power of 6.5 mW. In the case of E. coli, bacterial growth was completely inhibited only when combining a PS incubation period of 120 min with concentrations over 20 μM. [ABSTRACT FROM AUTHOR]

Early diagnosis is one of the most important factors that increase the therapeutic potential of the disease. Diagnoses conducted by conventional equipment are expensive, time-consuming, burdensome to patients, and do not have high success rates. Diagnostic methods have also been investigated using nanoparticles. However, there have been no significant improvements in the early diagnosis of disease. The diagnosis technique proposed in this paper consumes less time, is more cost-effective, and more accurate. It uses a new concept-a low-intensity fluorescence molecular imaging system with a lock-in technique. This study applied the lock-in technique to basic research in contrast enhancement and optimization. This improved fluorescence distribution analysis, resulting in increased resolution of optical molecular imaging for early diagnosis of disease. An experimental lock-in fluorescence imaging system, which used a variety of fluorescent dyes, achieved signal amplification 100 times greater than that of a conventional fluorescence imaging system. The results of this study demonstrate that the lock-in technique could significantly improve optical molecular imaging technology, making it possible to achieve early diagnosis of disease. [ABSTRACT FROM AUTHOR]

This paper describes the synthesis of new quinoline derivatives, molecules that has been long interest in the organic and medicinal chemistry. Through the Multicomponent Reaction (MCR), an important tool in modern synthetic methodology, that generate products with good structural complexity, in addition to economy of atoms and selectivity, we provide easy access to the preparation of quinoline derivatives. The reactions were promoted by niobium pentachloride, as a Lewis acid. Subsequently, the synthesis of new aminoquinoline derivatives with good yields was performed using Pd/C and hydrazine. The photophysical investigations of quinoline derivatives show the substituent effect on the optical properties characterization was done by absorption and photoluminescence measurements with quantum yields of up to 83 %, the presence of the amino group at position 6 at the quinoline backbone was crucial for obtaining these increased quantum yields. Results show that these molecules may have potential use for a variety of applications and mainly attracts attention because of its wide potential of applicability in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Using a transfer printing technique, we imprint a layer of a designated near-infrared fluorescent dye BTP-eC9 onto a thin layer of Pt(II) complex, both of which are capable of self-assembly. Before integration, the Pt(II) complex layer gives intense deep-red phosphorescence maximized at ~740 nm, while the BTP-eC9 layer shows fluorescence at > 900 nm. Organic light emitting diodes fabricated under the imprinted bilayer architecture harvest most of Pt(II) complex phosphorescence, which undergoes triplet-to-singlet energy transfer to the BTP-eC9 dye, resulting in high-intensity hyperfluorescence at > 900 nm. As a result, devices achieve 925 nm emission with external quantum efficiencies of 2.24% (1.94 ± 0.18%) and maximum radiance of 39.97 W sr−1 m−2. Comprehensive morphology, spectroscopy and device analyses support the mechanism of interfacial energy transfer, which also is proved successful for BTPV-eC9 dye (1022 nm), making bright and far-reaching the prospective of hyperfluorescent OLEDs in the near-infrared region. The low photoluminescence quantum yield of near-infrared (NIR) emitters has limited their application in organic light-emitting diodes (OLEDs). Here, authors realize NIR OLEDs through interfacial energy transfer from platinum(II) complexes to a non-fullerene acceptor based on a sandwiched structure. [ABSTRACT FROM AUTHOR]

In non-viscous aqueous solutions, the cyanine fluorescent dyes Cy3 and Cy5 have rather low fluorescence efficiency (the fluorescence quantum yields of Cy3 and Cy5 are 0.04 and 0.3, respectively [1-2]) and short excited state lifetimes due to their structural features. In this work, we investigated the effect of solubility and rotational degrees of freedom on the fluorescence efficiency of Cy3 and Cy5 in several ways. We compared the fluorescence efficiencies of two cyanine dyes sCy3 and sCy5 with the introduction of a sulfonyl substituent in the aromatic ring as well as covalently bound to T10 oligonucleotides. The results show that because of the different lengths of the polymethine chains between the aromatic rings of the dyes, cis–trans-isomerization has a much greater effect on the Cy3 molecule than on the Cy5 molecule, while the effect of aggregation is also significant. [ABSTRACT FROM AUTHOR]

The paper reports on synthesis and spectroscopic study of novel N-butyl-4-styryl-1,8-naphthalimide dyes bearing methoxy ( 1), dimethoxy ( 2), and dimethylamino ( 3) groups in the styryl fragment. It is shown that all synthesized compounds demonstrate positive solvatochromism, high values of Stokes shift in polar solvents, and fluorescence in the long wavelength part of visible range. These facts indicate a potential application of these compounds as fluorescent dyes in the biochemistry. The changes in the dipole moments of the molecules caused by excitation were estimated using Lippert-Mataga equation. The obtained results could be assigned to the formation of the excited states with intramolecular charge transfer. The formation of the twisted states with charge transfer was suggested in the case of compound 3, while the fluorescence quantum yield was significantly reduced in polar protic solvents. [ABSTRACT FROM AUTHOR]

A novel fluorescent dye, 1-(2-hydroxyethyl)-4-((E)-2-(3-benzothiazol-2yl-9-ethyl-carbazole-3yl)vinyl) pyridinium bromide, was synthesized for determination of protein and its structure was characterized by H NMR. Photophysics of the new probe in different solvents has been delineated in this paper, the new fluorescent molecular dye exhibited a large stokes-shifted and fluorescence quantum yields in organic solvent. The photostability and thermostability of the new dye were also studied and the results suggested the stable was excellent. The interactions of the dye with bovine serum albumin (BSA) , Human serumal bumin (HSA) and calf thymus deoxyribonucleic acid ( ctDNA) were studied by fluorescence and absorption spectroscopy. The binding constant for BSA, HSA and DNA were calculated to be 8.91 × 10, 1.86 × 10 and 2.9 × 10, respectively. The experimental results indicated a potential value of the new dye for biomarker. [ABSTRACT FROM AUTHOR]

The work examines the effect of inhibitors of cytosolic Ca(2+)-dependent and Ca(2+)-independent phospholipases A2 on bilayer lipid membranes. It was established that trifluoroperazine (TFP) and, to a lesser extent, arachidonyl trifluoromethyl ketone (AACOCF3) and palmitoyl trifluoromethyl ketone (PACOCF3) were able to permeabilize artificial lipid membranes (BLM and liposomes). It was shown that AACOCF3 lowered the temperature of phase transition of DMPC liposomes, inducing disordering of the hydrophobic region of lipid bilayer. TFP disordered membranes both in the hydrophobic region and in the region of hydrophilic heads, this being accompanied by changes in the membrane permeability: appearance of a channel-like BLM activity and leakage of sulforhodamine B from liposomes. In contrast to AACOCF3 and TFP, PACOCF3 increased membrane orderliness in the hydrophobic region (heightened the temperature of phase transition of DMPC liposomes) and in the region of lipid heads. The effectiveness of AACOCF3 and PACOCF3 as inductors of BLM and liposome permeabilization was considerably lower comparatively to TFP. As revealed by dynamic light scattering, incorporation of TFP, AACOCF3 and PACOCF3 into the membrane of liposomes resulted in the increase of the average size of particles in the suspension, presumably due to their aggregation or fusion. The paper discusses possible mechanisms of the influence of phospholipase A2 inhibitors on bilayer lipid membranes. [ABSTRACT FROM AUTHOR]

This paper reports the utilization of a fluorescent dye, 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetra-methyljulolidyl-9-enyl)-4H-pyran (DCJTB) as the surface modifier of ZnO nanorods for inverted type hybrid solar cell application. The DCJTB solution with concentrations of 10 and 15 mM was spin-coated onto the ZnO nanorod arrays grown on the fluorine-doped tin oxide glass substrate pre-coated with ZnO seed layer. The poly(3-hexylthiophene-2,5-diyl) (P3HT) as electron donor was then spin-coated onto ZnO nanorod arrays, followed by the deposition of silver as anode using magnetron sputtering technique. A large portion of pre-coated DCJTB has been redissolved and washed out in the subsequent P3HT spin coating process. Nevertheless, the increase in hydrophobicity of ZnO nanorod arrays pre-coated with DCJTB leads to improved interfacial compatibility between ZnO nanorods and P3HT. As a result, the enhanced exciton dissociation efficiency at the ZnO nanorods/P3HT interfaces results in the increment of short circuit current density and open circuit voltage. In addition, DCJTB residue covering the FTO exposed area could reduce the hole leakage current from P3HT to FTO, hence resulting in higher open circuit voltage. The device with the optimum DCJTB pre-coating concentration of 10 mM exhibited almost two times increase in power conversion efficiency as compared to that of pristine device. [ABSTRACT FROM AUTHOR]

Retinal, the vitamin A aldehyde, is a potent photosensitizer that plays a major role in light-induced damage to vertebrate photoreceptors. 11-Cis retinal is the light-sensitive chromophore of rhodopsin, the photopigment of vertebrate rod photoreceptors. It is isomerized by light to all-trans, activating rhodopsin and beginning the process of light detection. All-trans retinal is released by activated rhodopsin, allowing its regeneration by fresh 11-cis retinal continually supplied to photoreceptors. The released all-trans retinal is reduced to all-trans retinol in a reaction using NADPH. We have examined the photooxidation mediated by 11-cis and all-trans retinal in single living rod photoreceptors isolated from mouse retinas. Photooxidation was measured with fluorescence imaging from the oxidation of internalized BODIPY C11, a fluorescent dye whose fluorescence changes upon oxidation. We found that photooxidation increased with the concentration of exogenously added 11-cis or all-trans retinal to metabolically compromised rod outer segments that lacked NADPH supply. In dark-adapted metabolically intact rod outer segments with access to NADPH, there was no significant increase in photooxidation following exposure of the cell to light, but there was significant increase following addition of exogenous 11-cis retinal. The results indicate that both 11-cis and all-trans retinal can mediate light-induced damage in rod photoreceptors. In metabolically intact cells, the removal of the all-trans retinal generated by light through its reduction to retinol minimizes all-trans retinal-mediated photooxidation. However, because the enzymatic machinery of the rod outer segment cannot remove 11-cis retinal, 11-cis-retinal-mediated photooxidation may play a significant role in light-induced damage to photoreceptor cells. [ABSTRACT FROM AUTHOR]

Introduction: Bile duct injury is a major complication of laparoscopic cholecystectomy (LC). Indocyanine green near-infrared fluorescence cholangiography (ICG-NIFC) is a well-recognized technique who provides an intraoperative mapping of the biliary system. Methods: All patients underwent urgent LC and randomly divided into two groups: in one group, only white light imaging was used and, in the ICG group, ICG was used. Due to the heterogeneity of our groups, a PSM was performed with a 1:1 PSM cohort. Results: The use of ICG clearly decreases the operation time (p value 0.002). The overall rate of intra- and post- operative complications was 4.17% and 15.8% respectively. Post-operative biliary duct injury trend decreases in ICG group and after the homogenization of the 2 cohorts, the intra- and post- operative complications (including vascular and biliary duct injury) results changed with a highest rate of complication in the cohort with no-ICG administration. The use of NIFC demonstrated a protective effect against intra- and post- operative complications and biliary duct injury (HR 0.037, p value 0.337 and HR 0.039, p value 0.647; HR 0.288; p value 0.05 and HR 0.635; p value 0.687, respectively). Conclusions: The intra-operative use of NIFC showed a trend in the reduction of the rate of intra- and post-operative complications, the duration of surgery, and the length of hospital stay. ICG is a highly safe approach to urgent and emergency LC, as for elective LC, and could lead the surgeon to conduct the procedure more efficiently. [ABSTRACT FROM AUTHOR]

Inorganic nanowires-based organogel, a class of emerging organogel with convenient preparation, recyclability, and excellent mechanical properties, is in its infancy. Solidifying and functionalizing nanowires-based organogels by designing the gelator structure remains challenging. Here, we fabricate Ca2-P2W16 and Ca2-P2W15M nanowires utilizing highly charged [Ca2P2W16O60]10− and [Ca2P2W15MO60]14−/13− cluster units, respectively, which are then employed for preparing organogels. The mechanical performance and stability of prepared organogels are improved due to the enhanced interactions between nanowires and locked organic molecules. Compressive stress and tensile stress of Ca2-P2W16 nanowires-based organogel reach 34.5 and 29.0 kPa, respectively. The critical gel concentration of Ca2-P2W16 nanowires is as low as 0.28%. Single-molecule force spectroscopy confirms that the connections between cluster units and linkers can regulate the flexibility of nanowires. Furthermore, the incorporation of fluorophores into the organogels adds fluorescence properties. This work reveals the relationships between the microstructures of inorganic gelators and the properties of organogels, guiding the synthesis of high-performance and functional organogels. Functionalizing inorganic organogels is a challenge and can have a negative impact on their mechanical properties. Here, the authors present nanowire-based organogels based on highly charged polyoxometalate cluster units that are mechanically tuned and loaded with fluorescent dyes. [ABSTRACT FROM AUTHOR]

The paper presents the results of calculating the threshold pumping power necessary for laser generation in cholesteric liquid crystals doped with fluorescent dyes. Calculations have been performed with allowance for (i) specific spectral properties of the chiral cholesteric medium as a photonic structure and (ii) the spatially distributed character of feedback in the active medium. The dependences of the threshold pumping power on the sample thickness, dye concentration, and leading front widths of long pumping pulses have been studied. [ABSTRACT FROM AUTHOR]

Hypersensitivity reactions to the commonly used denture base resins are infrequently reported. When they have been reported, most acrylic hypersensitivity reactions have been described as local contact reactions with few reports identifying any significant systemic symptoms. This paper reports a case where the patient suffered extensive systemic symptoms which were strongly linked to denture wear. A variety of alternative dentures of different resin content were constructed over time with varying reactions. The patient was patch-tested and responded with positive reactions to pure dye samples supplied by manufacturers of the resins. She also failed to react to dentures made in a clear acrylic with no dye components. These factors strongly support the hypothesis that the reactions experienced by this patient to some denture resins was the result of the incorporated colouring agents. It is therefore suggested that in cases where a hypersensitivity reaction with systemic manifestations to a denture base resin is suspected, questioning with regard to other reactions to colourants and patch testing for dyestuffs should be considered in addition to the use of a resin with no colouring agents in construction of replacement prostheses. [ABSTRACT FROM AUTHOR]

Herein, we describe the design, synthesis and optoelectronic characterization of a new series of highly fluorescent dyes configured with a D–A–D′ architecture, viz. CP1 to CP7. In the new molecular design, various electron-donating scaffolds were integrated with an efficient electron-accepting trialkoxyphenyl-substituted cyanopyridone moiety to study the effect of donor strength on their thermal and opto-physical properties. A detailed investigation of their thermal properties reveals that they are thermally robust with high melting and decomposition temperatures. Furthermore, in-depth photophysical studies expose their remarkable fluorescence ability in both solution and aggregated state within a wide spectral range from blue to orange. Evidently, among all the fluorophores, dyads bearing amino donors were found to be highly intense emitters due to their superior donating strength. Furthermore, solvatochromic studies showcase their ICT-dominated optoelectronic properties and it was confirmed by different correlation studies. Finally, the experimental results were correlated with their quantum chemical simulation data. [ABSTRACT FROM AUTHOR]

We developed a type of dye-doped cholesteric liquid crystal, which were used for fluorescence enhancement and dual-mode multicolor patterns. We added dye molecules (BBOT, coumarin 6 (C6) and rhodamine B (RhB)) to liquid crystals, and cholesteric liquid crystals (CLC) exhibited selective reflection characteristics. When the reflection wavelength overlaps with the peak of the fluorescent dye, the luminescence intensity of the dye molecules could be adjusted. We used two methods to adjust the reflection wavelength of the cholesteric liquid crystals by changing the content of chiral additives and the isomerization degree of azo molecules. We used the screen printing and stencil printing methods to combine liquid crystal particles containing different fluorescent colors to prepare multicolor patterns. Moreover, the photoisomerization characteristics of the azo molecules were also used to achieve brilliant firework-like images upon exposure to ultraviolet and visible light. In addition, we also realized a face-changing stunt with facial makeup during a performance in the Sichuan Opera, a traditional Chinese folk art. We made use of the difference between reflection color and luminescence intensity upon light irradiation to present orange, green, blue and dark-blue facial effects. [ABSTRACT FROM AUTHOR]

Indocyanine green (ICG) is a fluorescent dye that can be used intraoperatively to assess tissue perfusion, as well as perform leak testing. This study aims to summarize published manuscripts on outcomes of ICG use and reduction of complications compared to traditional leak test and tissue perfusion evaluation. A PubMed search using "ICG and bariatric surgery," "ICG and gastric sleeve," "ICG and gastric bypass," and "ICG and revisional bariatric surgery" was performed. The proportion of patients who underwent an intraoperative decision change due to ICG was 3.8% (95% CI: 2.0 to 7.2%). ICG fluorescent imaging in bariatric surgery is a valuable tool, and further studies are needed to confirm its utility for routine use in both standard or complex cases (PROSPERO #418126). [ABSTRACT FROM AUTHOR]

Objective: To investigate the molecular mechanisms underlying the effect of baicalin on prostate cancer (PCa) progression both in vivo and in vitro. Methods: The in situ PCa stem cells (PCSCs)-injected xenograft tumor models were established in BALB/c nude mice. Tumor volume and weight were respectively checked after baicalin (100 mg/kg) treatment. Hematoxylin-eosin (HE) staining was used to observe the growth arrest and cell necrosis. mRNA expression levels of acetaldehyde dehydrogenase 1 (ALDH1), CD44, CD133 and Notch1 were determined by reverse transcription-polymerase chain reaction. Protein expression levels of ALDH1, CD44, CD133, Notch1, nuclear factor κB (NF-κB) P65 and NF-κB p-P65 were detected by Western blot. Expression and subcellular location of ALDH1, CD44, CD133, Notch1 and NF-κB p65 were detected by immunofluorescence analysis. In vitro, cell cycle distribution and cell apoptosis of PC3 PCSCs was assessed by flow cytometry after baicalin (125 µmol/L) treatment. The migration and invasion abilities of PCSCs were assessed using Transwell assays. Transmission electron microscopy scanning was utilized to observe the structure and autophagosome formation of baicalin-treated PCSCs. In addition, PCSCs were infected with lentiviruses expressing human Notch1. Results: Compared with the control group, the tumor volume and weight were notably reduced in mice treated with 100 mg/kg baicalin (P<0.05 or P<0.01). Histopathological analysis showed that baicalin treatment significantly inhibited cell proliferation and promoted cell apoptosis. Furthermore, baicalin treatment reduced mRNA and protein expression levels of CD44, CD133, ALDH1, and Notch1 as well as the protein expression of NF-κB p-P65 in the xenograft tumor (P<0.01). In vitro, the cell proliferation of PCSCs was significantly attenuated after treatment with 125 µmol/L baicalin for 72 h (P<0.01). The cell migration and invasion rates were decreased following treatment with baicalin for 48 and 72 h (P<0.01). Baicalin notably induced cell apoptosis and seriously damaged the structure of PCSCs. The mRNA and protein expressions of CD133, CD44, ALDH1 and Notch1 in PCSCs were significantly downregulated following baicalin treatment (P<0.01). Importantly, the inhibitory effects of baicalin on PCa progression and stemness were reversed by Notch1 overexpression (P<0.05 or P<0.01). Conclusion: Mechanistically, baicalin exhibited a potential therapeutic effect on PCa via inhibiting the Notch1/NF-κB signaling pathway and its mediated cancer stemness. [ABSTRACT FROM AUTHOR]

Nanofibers with the cationic fluorescent molecules, 1-pyrenemethylamine hydrochloride (PyrMA) and α,β,γ,δ-tetrakis(1-methylpyridinium-4-yl)porphyrin p-toluenesulfonate (TMPyP), in the presence of complementary anionic chiral polysaccharide, hyaluronic acid (HA) and transparent polymer, polyethylene oxide (PEO) were successfully prepared using an electrospinning technique. The results showed that the fluorescence spectra of electrospun nanofibers (ENFs) of PEO-HA-PyrMA exhibit a higher amount of pyrene excimer emission when the [PyrMA]/[HA] ratio was increased from 0.5 to 1, while the concentration of TMPyP had no remarkable effect on the fluorescence of the PEO-HA-TMPyP ENFs. From circular dichroism (CD) characterization, the ENFs of both dyes exhibit stronger intensities in the apparent CD spectra upon increasing the dye ratio. Moreover, they also showed higher CD intensities when compared with those of solutions and thin films prepared using other methods. The apparent CD in this work was proved to mainly originate from linear dichroism (LD) and linear birefringence (LB) obtained by macroscopic alignment along the electrospinning process. These results suggest the advantages of molecular orientation via electrospinning, together with chirality induction by incorporation of a chiral HA polymer. The enhancement of these polarization properties provides great possibilities for improving fluorescent-chiral nanofibers for further optoelectronic applications. [ABSTRACT FROM AUTHOR]

In the common marmoset ( Callithrix jacchus), the cortical projection from the pulvinar and other diencephalic structures into the striate and prestriate cortex was investigated with various fluorescent retrograde tracers. Single cortical injections as well as multiple injections at distances of 1-2 mm with one tracer into an extended but coherent cortical region were applied. Fields with multiple injections were placed so that they touched each other (minimal distances 2 to 3 mm). Retrogradely labelled cells in the LGN and/or the pulvinar were arranged in coherent columns, volumes or slabs, but cell volumes resulting from neighbouring cortical injections overlapped at their border (for details of the thalamo-cortical topography see the companion paper Dick et al. (1991)). Double labelled cells (dl) were only found in the zones of overlap of the cell volumes labelled by the respective tracers. The relative number of dl-cells in these overlap zones was 6.2 ± 3.1%. The dl-frequency was the same in the various nuclei of the pulvinar and the LGN. In the main layers of LGN, dl-cells were found only in the overlap zone of two injection fields into area 17, but a few dl-cells were found in interlaminar cells after injections into area 17 and 18. Maximal cortical distances between injection fields which produced dl in the pulvinar, were 3 to exceptionally 4 mm but dl was highest at injection distances ≤2.5 mm and decreased sharply at wider distances. Such overlap zones were concerned with identical or overlapping regions of visual field representation in the cortex and probably also in the pulvinar. Although in individual experiments up to four different tracers were injected into different striate/prestriate regions, often embracing the same visual field representation, individual cells in the pulvinar showed dl from maximally only two tracers injected into neighbouring cortical regions. We conclude that dl in the posterior thalamic projection nuclei is determined essentially by cortical distance and thus reflects the local domain of branching of thalamo-cortical afferents. Pruning of such branches during development may further restrict bifurcating axons to identical visual field representations, but representation of identical visual field regions in different visual areas is not, per se, a sufficient condition for dl. It is not found if such regions are further apart from each other than the typical local domain of 2-3 mm, exceptionally up to 4 mm in one experiment after injections into area 17 and MT. Dl in the intralaminar nucleus CeL (5.0 ± 4.6%), the claustrum (5.4 ± 3.6%) and in the amygdala (5.7 ± 1.9%) was of the same order as in the pulvinar and LGN. In the hypothalamus around 10% and in the Nucleus basalis Meynert 15.8% of the cells labelled by visual cortical injections were double labelled. In all these extrathalamic regions dl was also restricted to overlap zones, but overlap of labelled fields in these nuclei was much wider and included the whole striate/prestriate cortex except for some topographical separation of striate and prestriate projection zones in the claustrum. Only in the Nucl. basalis Meynert and the hypothalamus some cells were labelled by three tracers. [ABSTRACT FROM AUTHOR]

We disclose a novel boron trifluoride induced C–H activation and difluoroboronation at room temperature, thus providing a straightforward gateway to a series of N,O-bidentate organic BF2 complexes. The scope of the method is demonstrated with 24 examples. All the synthesized compounds exhibit fluorescence and some of them have large Stokes shifts. [ABSTRACT FROM AUTHOR]

Optical clearing with high-refractive-index (high-n) reagents is essential for 3D tissue imaging. However, the current liquid-based clearing condition and dye environment suffer from solvent evaporation and photobleaching, causing difficulties in maintaining the tissue optical and fluorescent features. Here, using the Gladstone-Dale equation [(n−1)/density=constant] as a design concept, we develop a solid (solvent-free) high-n acrylamide-based copolymer to embed mouse and human tissues for clearing and imaging. In the solid state, the fluorescent dye-labeled tissue matrices are filled and packed with the high-n copolymer, minimizing scattering in in-depth imaging and dye fading. This transparent, liquid-free condition provides a friendly tissue and cellular environment to facilitate high/super-resolution 3D imaging, preservation, transfer, and sharing among laboratories to investigate the morphologies of interest in experimental and clinical conditions. Current liquid-based optical clearing protocols can suffer from solvent evaporation and photobleaching. Here, the authors develop a solid high-refractive-index polymer to embed mouse and human tissues for clearing and antifade high-resolution 3D imaging. [ABSTRACT FROM AUTHOR]

Measurement of liquid temperature in single or multiphase systems is a topic of high interest for fluid mechanics in order to have a better understanding of heat exchange and phase changes in many physical problems as well as for improving industrial processes. Laser-induced fluorescence thermometry is a powerful tool to investigate liquid temperature in permanent or transient conditions due to the fast fluorescence response of the technique. By diluting a fluorescent dye sensible to temperature in a liquid and after laser excitation of this solution at a specific and known wavelength, fluorescence is emitted by the dye almost instantaneously and could be isolated as a function of the temperature of the dye thanks to a ratiometric method. In this work, two fluoresceins commonly used as fluorescent dyes were spectrally studied in water at excitation wavelengths of 473 and 532 nm. Fluorescein Disodium and Fluorescein 27 were chosen as they present positive and high-temperature sensitivities as well as low toxicity. Also, systematic calibrations between − 10 and 80 °C under liquid state are reported for aqueous solutions. Results are compared to available data from the literature, and temperature sensitivity is discussed in relation with pH, excitation wavelength and temperature range in order to extend the knowledge on the topic and for clarification regarding some confusion found in the literature. Finally, we proposed an improvement of a method analyzing the sensitivity as a function of the wavelength for a better approach in the process of selecting spectral bands for LIF-T applications. Following this method, two examples of practical application are given for dye and spectral band selection depending on the constraints of experimental measurement. [ABSTRACT FROM AUTHOR]

Flexible methylene containing N,N′-bis-(benzyl)-3,4,9,10-perylenebis(dicarboximide) (1) was synthesized. Self-assembled microstructures (hollow tubes, average length and width: 7.7 and 0.8 μm) of 1 were also prepared (T-1). Comparative studies of the optical, thermal and electrochemical properties of 1 and T-1 have been extensively carried out. The T-1 hallow tubes have shown extremely broad absorption in the near-infrared (300–800 nm) region (NIR) even in solution and intensified conductivity in the solid-state compared to 1. Under daylight and a UV lamp (365 nm), the emission colors of 1 are uniform pink and fluorescent yellow, respectively. Under the same conditions the colors of T-1 change to deep brown and glowing red, respectively. Two different isopotential points obtained through CV scans for 1 indicate the presence of two interconvertible chromophores within the system. The results clearly indicate that the anodic and cathodic processes are extremely intensified in the self-assembled T-1 structure. [ABSTRACT FROM AUTHOR]