Ratiometric Detection of γ-Glutamyltransferase in Human Colon Cancer Tissues Using a Two-Photon Probe.

γ-Glutamyltransferase (GGT) plays a role in cleaving the γ-glutamyl bond of glutathione. The GGT is known to be overexpressed in some tumors and has been recognized as a potential biomarker for malignant tumors. Colon cancer is one of the most common cancers worldwide; however, there is no quantitative method for detecting cancer cells in human colon tissues. In this study, we report a ratiometric two-photon probe for GGT that can be applied in human colon tissues. The probe (Probe 2) showed high fluorescence efficiency, marked fluorescence changes, excellent kinetics, and selectivity for the GGT in live colon cells. Additionally, we obtained ratiometric two-photon microscopy images of GGT activity in human colon tissue. We used this method to compare normal and cancer tissues based on their ratio values; the ratio value was higher in cancer tissue than in normal tissue. This study provides a method for quantitative analysis of GGT, particularly in human colon cancer, which will be useful for studying GGT-related diseases and diagnosing colon cancer.

A FRET-based ratiometric two-photon fluorescent probe for superoxide anion detection and imaging in living cells and tissues.

The superoxide anion (O2˙-) plays a crucial role in several physiological processes and many human diseases. Developing new methods for O2˙- detection in biological systems is very important. A FRET-based two-photon (TP) fluorescent probe with a ratiometric signal, TFR-O, was developed. A naphthalene derivative based TP fluorescent group was selected as the energy donor group, and a rhodol fluorescent group was chosen as the energy acceptor; the trifluoromethanesulfonate group was chosen as the recognition moiety. After reacting with O2˙-, the recognition moiety was removed and the fluorophore was released, leading to a fluorescence intensity decrease at the wavelength of 425 nm and a significant enhancement of the fluorescence intensity at 550 nm. The fluorescence intensity ratio between 550 and 425 nm (I550/I425) varied from 0.15 to 6.72, with the O2˙- concentration increasing from 0 to 50 µM. The detection limit of the TFR-O was 83 nM. Moreover, TFR-O was applied for detecting and imaging O2˙- in cells and liver tissues.

A naphthalene-based fluorescent probe with a large Stokes shift for mitochondrial pH imaging.

A mitochondrial-targeted pH fluorescent probe 4-(2-(6-hydroxynaphthalen-2-yl)vinyl)-1-methylpyridin-1-ium was facilely synthesized via the carbon-carbon double bond bridging of 6-hydroxy-2-naphthaldehyde and 1,4-dimethylpyridinium iodide salt. The probe exhibited remarkable pH-dependent behavior in the linear range of 7.60-10.00, with a pKa value of 8.85 ± 0.04 near mitochondrial pH. A significantly large Stokes shift of 196 nm was obtained, which reduces the interference of excitation light. Application of the probe in live HepG2 cells indicated that the probe had excellent mitochondrial targeting ability and was successfully used to visualize mitochondrial pH fluctuations in live cells.

Modeling marine oily wastewater treatment by a probabilistic agent-based approach.

This study developed a novel probabilistic agent-based approach for modeling of marine oily wastewater treatment processes. It begins first by constructing a probability-based agent simulation model, followed by a global sensitivity analysis and a genetic algorithm-based calibration. The proposed modeling approach was tested through a case study of the removal of naphthalene from marine oily wastewater using UV irradiation. The removal of naphthalene was described by an agent-based simulation model using 8 types of agents and 11 reactions. Each reaction was governed by a probability parameter to determine its occurrence. The modeling results showed that the root mean square errors between modeled and observed removal rates were 8.73 and 11.03% for calibration and validation runs, respectively. Reaction competition was analyzed by comparing agent-based reaction probabilities, while agents' heterogeneity was visualized by plotting their real-time spatial distribution, showing a strong potential for reactor design and process optimization.

Spectroscopic Properties of Naphthalene on the Surface of Ice Grains Revisited: A Combined Experimental-Computational Approach.

An experimental-computational method is used to investigate the spectroscopic behavior of naphthalene on the surface of ice grains. UV-vis diffuse reflectance and fluorescence spectroscopies of naphthalene combined with DFT and ADC(2) calculations provide evidence for the occurrence of excited-state associates. The measured and calculated bathochromic shifts of the S0 → S1 electronic transitions related to naphthalene dimers or naphthalene-ice interactions do not exceed 3 nm. The bands observed in the emission spectrum of frozen naphthalene solutions are assigned to excited dimers of different mutual orientations, naphthalene phosphorescence, and fluorescence of anthracene present as a trace impurity and populated by the energy transfer from excited naphthalene. Photochemical reactivity in/on ice and snow is dependent on the absorption properties and speciation of the compounds present in these media. Hence, within this study, we exploit frozen solutions of naphthalene to demonstrate both the absence of considerable bathochromic shift and a strong tendency to aggregate.

UV-curable gel formulations: Potential drug carriers for the topical treatment of nail diseases.

Nail diseases are common, cause significant distress and treatments are far from successful. Our aim was to investigate the potential of UV-curable gels - currently used as cosmetics - as topical drug carriers for their treatment. These formulations have a long residence on the nail, which is expected to increase patient compliance and the success of topical therapy. The gels are composed of the diurethane dimethacrylate, ethyl methacrylate, 2-hydroxy-2-methylpropiophenone, an antifungal drug (amorolfine HCl or terbinafine HCl) and an organic liquid (ethanol or NMP) as drug solvent. Following its application to a substrate and exposure to a UVA lamp for 2 min, the gel polymerises and forms a smooth, glossy and amorphous film, with negligible levels of residual monomers. No drug-polymer interactions were found and drug loading did not affect the film's properties, such as thickness, crystallinity and transition temperatures. In contrast, the organic solvent did influence the film's properties; NMP-containing films had lower glass transition temperatures, adhesion and water resistance than ethanol-based ones. Water-resistance being a desired property, ethanol-based formulations were investigated further for stability, drug release and ungual permeation. The films were stable under accelerated stability testing conditions. Compared to terbinafine, amorolfine was released to a greater extent, had a higher ungual flux, but a lower concentration in the nailplate. However, both drugs were present at considerably high levels in the nail when their MICs are taken into account. We thus conclude that UV-curable gels are promising candidates as topical nail medicines.

Process simulation and dynamic control for marine oily wastewater treatment using UV irradiation.

UV irradiation and advanced oxidation processes have been recently regarded as promising solutions in removing polycyclic aromatic hydrocarbons (PAHs) from marine oily wastewater. However, such treatment methods are generally not sufficiently understood in terms of reaction mechanisms, process simulation and process control. These deficiencies can drastically hinder their application in shipping and offshore petroleum industries which produce bilge/ballast water and produced water as the main streams of marine oily wastewater. In this study, the factorial design of experiment was carried out to investigate the degradation mechanism of a typical PAH, namely naphthalene, under UV irradiation in seawater. Based on the experimental results, a three-layer feed-forward artificial neural network simulation model was developed to simulate the treatment process and to forecast the removal performance. A simulation-based dynamic mixed integer nonlinear programming (SDMINP) approach was then proposed to intelligently control the treatment process by integrating the developed simulation model, genetic algorithm and multi-stage programming. The applicability and effectiveness of the developed approach were further tested though a case study. The experimental results showed that the influences of fluence rate and temperature on the removal of naphthalene were greater than those of salinity and initial concentration. The developed simulation model could well predict the UV-induced removal process under varying conditions. The case study suggested that the SDMINP approach, with the aid of the multi-stage control strategy, was able to significantly reduce treatment cost when comparing to the traditional single-stage process optimization. The developed approach and its concept/framework have high potential of applicability in other environmental fields where a treatment process is involved and experimentation and modeling are used for process simulation and control.

Direct immobilization of biotin on the micro-patterned PEN foil treated by excimer laser.

Polymers with functionalized surfaces have attracted a lot of attention in the last few years. Due to the progress in the techniques of polymer micro-patterning, miniaturized bioanalytical assays and biocompatible devices can be developed. In the presented work, we performed surface modification of polyethylene naphthalate (PEN) foil by an excimer laser beam through a photolithographic contact mask. The aim was to fabricate micro-patterned areas with surface functional groups available for localized covalent immobilization of biotin. It was found out that depending on the properties of the laser scans, a polymer surface exhibits different degrees of modification and as a consequence, different degrees of surface biotinylation can be achieved. Several affinity tests with optical detection of fluorescently labeled streptavidin were successfully performed on biotinylated micro-patterns of a PEN foil. The polymer surface properties were also evaluated by electrokinetic analysis, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The results have shown that PEN foils can be considered suitable substrates for construction of micro-patterned bioanalytical affinity assays.

Vertically π-expanded coumarin--synthesis via the Scholl reaction and photophysical properties.

A short and efficient access to a unique type of π-expanded coumarin is achieved. The strategic placement of naphthalene at the 4-position of coumarin allowed us to fuse these two moieties via aromatic dehydrogenation under Scholl conditions. The intriguing optical properties of this π-expanded coumarin are discussed on the basis of quantum chemical calculations. The fluorescence quantum yield (∼20%) is significantly higher than that obtained for the classical 7-hydroxycoumarin. The ratio of emission versus radiationless deactivation is governed by the following factors: decrease in the oscillator strength of the SS transition (vs. perylene), low yield of intersystem crossing and strong internal conversion originating from the activity of the number of vibronic states.

Highly efficient exciplex formation via radical ion pair recombination in X-irradiated alkane solutions for luminophores with short fluorescence lifetimes.

X-irradiation of alkane solutions of N,N-dimethylaniline with various organic luminophores produces characteristic emission bands ascribed to the corresponding exciplexes. In contrast to optical generation, which requires diffusion-controlled quenching of excited states, an additional channel of exciplex formation via irreversible recombination of radical ion pairs is operative here, which produces exciplexes in solution with high efficiency even for p-terphenyl and diphenylacetylene having fluorescence decay times of 0.95 ns and 8 ps, respectively. The exciplex emission band is sensitive to an external magnetic field and exerts a very large observed magnetic field effect of up to 20%, the maximum possible value under the conditions of the described experiment.

Photosolvolysis of bulky (4-hydroxyphenyl)naphthalene derivatives.

Six new naphthylphenols , bearing bulky hydroxymethyl substituents on the naphthalene, were synthesized and their photoreactivity was investigated by preparative irradiation, fluorescence measurements, and laser flash photolysis. All derivatives (in S1) undergo deprotonation of the phenolic OH in the aqueous solution. Also, fluorescence quenching with HClO4 in the pH range 2-4 indicates that can be protonated in S1. Formation of QMs most probably takes place sequentially, triggered by the phenol deprotonation. However, with the present data, a mechanism that involves simultaneous deprotonation and the loss of OH(-) cannot be ruled out. Photodehydration takes place only for , , and , delivering the corresponding QMs which react with nucleophilic solvents giving the corresponding photosolvolysis products. The other less likely option for the formation of the observed solvolysis products from , , and may involve some radical species. Photodehydration of and was not observed which may be due to the anticipated high energy of the corresponding sterically-congested and . The most efficient photosolvolyses were observed for the 2,6-substituted naphthalenes.

Degradation of organic pollutants by an integrated photo-Fenton-like catalysis/immersed membrane separation system.

To resolve the continuously reuse problem of fine catalysts, a new reactor was investigated by coupling the heterogeneous photo-Fenton-like oxidation with membrane separation. The reactor consisted of a Xe lamp, a submerged membrane module and FeVO(4) as catalyst with high activity. Results showed that the catalyst was successfully left in the reactor. It was proved by the kinetics study of membrane fouling that the avoidless membrane fouling was brought mainly by surface cake, at catalyst concentration of 4 g/L, it accounted for more than 90% of the total resistance. The kinetics study of catalytic degradation of AO II under sub-critical flux showed the optimal concentration of catalyst was 0.5 g/L and under this concentration the membrane fouling was negligible. For a residence time of 60 min, the degradation efficiency of AO II reached more than 99% and the chemical oxygen demand (COD) removal efficiency was as high as 91%. The model of continuous stirred tank reactor could predict well for the degradation which was consistent with hydrodynamics study. Moreover, the PFM reactor shows a long-term behavior with both membrane and catalyst in it and merits consideration for scaled-up trials.

Removal of organic dyes by UV/H2O2 process: modelling and optimization.

The effects of different operational parameters on the decolorization of a dye solution containing C.I. Acid Blue 92 (AB92) or C.I. Acid Black 1 (AB1) by the UV/H2O2 process were optimized using response surface methodology (RSM). The reaction time, dye and H2O2 initial concentrations and distance of the UV lamp from the solution were chosen as input variables. The removal process was performed according to a central composite design. Predicted results by the proposed models were in good agreement with experimental values (R2 = 0.942 and 0.957 for AB92 and AB1, respectively). The optimum points were located by graphical response surfaces and contour plots. The removal process of the dyes was compared and the efficiency difference justified by considering the chemical structure of the dyes. Additionally, the electrical energy consumption and the related treatment costs were estimated employing the figure-of-merit electrical energy per order (E(EO)).

Mesoporous zinc ferrite: synthesis, characterization, and photocatalytic activity with H2O2/visible light.

Mesoporous ZnFe(2)O(4) (meso-ZnFe(2)O(4)) was synthesized by a hydrothermal process in which cetyltrimethylammonium bromide (CTAB) participates in the reaction to produce nanocrystals. Synthesized ZnFe(2)O(4) was characterized by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, scanning electronic microscopy (SEM), transmission electron microscopy (TEM), and diffuse reflectance spectra (DRS). The meso-ZnFe(2)O(4) was resulted from the agglomeration of nanoparticles with size of 5-10nm. The photocatalytic activity of ZnFe(2)O(4) under visible light (λ>400 nm) was evaluated by the degradation of Acid Orange II (AOII) at different sintering temperatures, the amount of ZnFe(2)O(4), and the concentration of H(2)O(2). The photocatalytic degradation of AOII was almost complete within 2h in H(2)O(2)/visible light system. The high efficiency for AOII degradation was attributed to the strong absorption of ZnFe(2)O(4) in visible-light region and the generation of reactive OH by H(2)O(2) in the system. The involvement of OH in oxidizing AOII was examined by determining the photocurrent of ZnFe(2)O(4), [OH], and degradation rates using different scavengers. Organic compounds as intermediates of the degradation process were identified by LC/MS. Moreover, ZnFe(2)O(4) retained their degradation efficiencies for a series of repetitive batch runs, indicating the true photocatalytic process.

Adsorption of naphthalene onto sonicated talc from aqueous solutions.

The adsorption behavior of naphthalene onto naturally hydrophobic talc from aqueous solution was investigated in this study. The natural talc was first pretreated by sonication to improve the surface characteristics and enhance the uptake capacity by increasing the specific surface area (SSA) of talc. The naphthalene uptake of talc was found as 276 mg g(-1) and increased to 359 mg g(-1) after the sonication. Adsorption studies also showed that the adsorption of naphthalene onto the sonicated talc was not affected by changes in pH suggesting that the main driving forces for naphthalene adsorption onto talc was hydrophobic bonding rather than electrostatic force. The pseudo-first and pseudo-second orders and intraparticle diffusion equation were used to evaluate the kinetic data and the constants were determined. Adsorption process of naphthalene onto talc followed the pseudo-second-order rate expression for different initial naphthalene concentrations. The Langmuir and Freundlich isotherm models were used to model the isotherm data for their applicability. The Freundlich isotherm best fitted for the adsorption of naphthalene onto talc.

Synthesis, properties and in vitro photodynamic activity of water-soluble azaphthalocyanines and azanaphthalocyanines.

In this work zinc azaphthalocyanines (AzaPcs) from the group of tetrapyrazinoporphyrazines and zinc azanaphthalocyanines from the group of tetra[6,7]quinoxalinoporphyrazines (TQP) with eight diethylaminoethylsulfanyl substituents were synthesized. Tertiary amines were later quaternized with ethyl iodide to obtain water-soluble photosensitizers (PSs). Quaternized compounds showed high singlet oxygen quantum yields as determined in DMF by monitoring decomposition of 1,3-diphenylisobenzofuran. In water medium, quaternized AzaPc derivatives appeared in monomeric form in a wide range of concentrations while quaternized TQP derivatives showed aggregation at higher concentrations (over 1 microM). Photodynamic activity was tested on Hep2 cells using light of lambda > 640 nm. Both quaternized dyes showed high photodynamic activity (IC(50) = 104 and 220 nm for AzaPc and TQP, respectively). Dark toxicity was not detected even at the highest concentration used in in vitro tests (200 microM) which indicates a promising therapeutic index of these new substances. Tested compounds localized inside the cells mainly within the lysosomes thus suggesting an endocytic mechanism of cellular uptake. No localization within mitochondria was detected. A great advantage of TQP derivatives over other PSs is their very strong absorption at 747 nm that allows activation at wavelengths penetrating deeper into human tissues.

Photocatalytic oxidation of dinitronaphthalenes: theory and experiment.

A combination of photocatalytic oxidation experiments and quantum mechanical calculations was used in order to describe the mechanism and the nature of the photocatalytic oxidation reactions of dinitronaphthalane isomers and interprete their reactivities within the framework of the Density Functional Theory (DFT). The photocatalytic oxidation reactions of three dinitronaphthalene isomers, 1,3-dinitronaphthalene, 1,5-dinitronaphthalene and 1,8-dinitronaphthalene in the presence of TiO(2) Degussa P-25 grade were investigated experimentally. The reactions were carried out in a Solarbox photoreactor equipped with a Xenon lamp. The removal of the individual substrates was followed by means of a gas chromatographic method. Nonpurgable organic carbon contents of the samples were determined by means of the catalytic oxidation method using Total Organic Carbon analyzer. With the intention of determining the best reactivity descriptors to explain the differences in the photocatalytic oxidation rates in terms of the molecular properties, geometry optimizations of the compounds were performed with the Density Functional Theory DFT at B3LYP/6-31G( *) level. In order to take the effect of adsorption on the oxidation rate, a cluster Ti(9)O(18) cut from the anatase bulk structure was modeled. The binding energies for the compounds were calculated by using the double-zeta basis set. Global hardness, softness, Fukui functions, local hardness-softness and local softness differences were calculated. The results show that the reactions investigated are orbital-controlled and electrophilic in nature. Local DFT descriptors reflect the reactivities of the dinitronaphthalene isomers better than the global ones, due to the differences in their adsorptive capacities.

Simultaneous removal of chromium and leather dye from simulated tannery effluent by photoelectrochemistry.

The feasibility of the photobleaching of a leather acid dye, acid red 151, simultaneously to degradation of anionic surfactant, Tamol, and reduction of Cr(VI) to the less toxic Cr(III) was investigated by photoelectrocatalytic oxidation. The best experimental conditions were found to be pH 2.0 and 0.1 mol L(-1) sodium sulfate when the nanoporous Ti/TiO2 photo anode was biased at +1.0 V and submitted to UV-irradiation. The photoelectrocatalytic oxidation promotes 100% discoloration, reducing around 98-100% of Cr(VI) and achieving an abatement of 95% of the original total organic carbon. The effect of pH, the applied potential, the Cr(VI) concentration and the complexation reaction between Cr(VI) and acid red dye were evaluated as to their effect on the kinetics of the reaction.

Formation of cubane-like photodimers from 2-naphthalenecarbonitrile.

Irradiation of 2-naphthalenecarbonitrile (2-NpCN) in solution with a light lambda > 280 nm results in the formation of three rigid cubane-like photodimers, anti-head-to-head 1, anti-head-to-tail 2, and syn-head-to-tail 3, which are not in line with the previously recognized regioselectivity. These cubane-like photodimers have been well characterized by spectroscopic investigation and/or X-ray crystal structural analysis in this work. Moreover, the separation of the optically pure enantiomers of 1, 2, and 3 has been achieved by HPLC resolution.

Photoexcited calphostin C selectively destroys nuclear lamin B1 in neoplastic human and rat cells - a novel mechanism of action of a photodynamic tumor therapy agent.

Lamin B1, a major component of the nuclear lamina, anchors the nucleus to the cytoskeletal cage, and controls nuclear orientation, chromosome positioning and, alongside several enzymes, fundamental nuclear functions. Exposing polyomavirus-transformed rat pyF111 fibroblasts and human cervical carcinoma (HCC) C4-I cells for 30 min to photoexcited perylenequinone calphostin C, i.e. Cal C(phiE), an established reactive oxygen species (ROS)-generator and protein kinase C (PKC) inhibitor, caused the cells to selectively oxidize and then totally destroy their nuclear lamin B1 by only 60 min after starting the treatment, i.e. when apoptotic caspases' activities had not yet increased. However, while the oxidized lamin B1 was being destroyed, lamins A/C, the lamin A-associated nuclear envelope protein emerin, and the nucleoplasmic protein cyclin E were neither oxidized nor destroyed. The oxidized lamin B was ubiquitinated and demolished in the proteasome probably by an enhanced peptidyl-glutaminase-like activity. Hence, the Cal C(phiE)-induced rapid and selective lamin B1 oxidation and proteasomal destruction ahead of the activation of apoptotic caspases was by itself a most severe molecular lesion impairing vital nuclear functions. Conversely, Cal C directly added to the cells kept in the dark damaged neither nuclear lamin B1 nor cell viability. Thus, our findings reveal a novel cell-damaging mechanism of a photodynamic tumor therapeutic agent.