A Highly Selective and Sensitive Fluorescent Chemosensor for Hg²⁺ in Neutral Buffer Aqueous Solution

A selective and sensitive fluorescent chemosensor for Hg2+, which was composed of two aminonaphthalimide fluorophores and a receptor of 2,6-bis(aminomethyl)pyridine, was synthesized through the reaction of 2,6-bis(chloromethyl)pyridine and N-[2-(2-hydroxyethoxy)ethyl]-4-piperazino-1,8-naphthalimide. The chemosensor showed an about 17-fold increase in fluorescence quantum yield upon addition of 1 equiv of Hg2+ in neutral buffer aqueous solution, and the other common metal ions did not notably disturb the detection of Hg2+

Surface activities and thermodynamic properties of novel cationic surfactants with hydroxymethyl group

<p>A new series of cationic surfactants, <i>N</i>–alkyl–<i>N,N</i>–dimethyl–<i>N</i>–(<i>p</i>–(hydroxymethyl) benzyl) ammonium chlorides (<i>p</i>-DHBA<i>-m</i>), were synthesized and the structures were characterized by ¹HNMR, ¹³CNMR, FT–IR and ESI–MS. The surface activities, thermodynamic properties and aggregation behaviors of <i>p</i>-DHBA<i>-m</i> in aqueous solutions were respectively studied by means of surface tension, isothermal titration calorimetry and steady-state fluorescence methods. Thermodynamic parameters show that the micellization is an entropy-driven process. According to the fluorescence quenching method, the micelle aggregation numbers (<i>N</i>_agg) of <i>p</i>-DHBA-<i>m</i> were calculated and found that the increase of temperature or the elongation of alkyl chain length could lead to the reduction of the <i>N</i>_agg, respectively.</p

Ratiometric and Water-Soluble Fluorescent Zinc Sensor of Carboxamidoquinoline with an Alkoxyethylamino Chain as Receptor

A novel “naked-eye” and ratiometric fluorescent zinc sensor (AQZ) of carboxamidoquinoline with an alkoxyethylamino chain as receptor was designed and synthesized. AQZ shows good water solubility and high selectivity for sensing; about an 8-fold increase in fluorescence quantum yield and a 75 nm red-shift of fluorescence emission upon binding Zn2+ in buffer aqueous solution are observed. Moreover, AQZ can enter yeast cells and signal the presence of Zn2+

Ni–MnO_<i>x</i> Catalysts Supported on Al₂O₃‑Modified Si Waste with Outstanding CO Methanation Catalytic Performance

A series of MnO_<i>x</i>-promoted Ni catalysts supported on Si waste contact mass (W) modified by Al₂O₃ were successfully prepared by the deposition–precipitation method for CO methanation. Compared with the Ni catalysts directly supported on W, Ni/Al₂O₃–Si and MnO_<i>x</i>-promoted Ni–MnO_<i>x</i>/Al₂O₃–Si catalysts exhibited much better catalytic performance for CO methanation, particularly the latter, which exhibited the least decrease in CO conversion (1%) and lowest carbon deposit (0.3 wt %) in a 110 h lifetime test. The structural characterizations showed the highest Ni dispersion and highest oxygen vacancy concentration in the Ni–MnO_<i>x</i>/Al₂O₃–Si catalyst. The added Al₂O₃ improves the dispersion of Ni, and the MnO_<i>x</i> promoter can restrain the sintering and aggregation of Ni particles during the process of reduction and reaction at high temperatures and provides more oxygen vacancies, which is conducive to the removal of carbonaceous species on the catalyst surface for anticoking

Clotrimazole regulates apoptotic protein levels in OSCC cells and tumor tissue.

<p>(A) CAL27 and UM1 cells were treated with 40 µM clotrimazole or DMSO for 12 h, 24 h, and 48 h. The expression of the anti-apoptotic protein Bcl-2 and the pro-apoptotic protein Bax was assessed by western blot. (B) The apoptosis-related protein expressions in tumors from control mice and clotrimazole-treated mice (150 mg/kg) were also analyzed by western blot analysis. Clotrimazole treatment decreased the expression of Bcl-2 and increased the level of Bax in clotrimazole-treated tumors compared with control animals. Data shows the representative of three independent experiments. Quantification of bands was performed using Image J software and the relative ratio was calculated by the density.</p

Clotrimazole induces apoptosis of OSCC cells.

<p>CAL27, SCC25 and UM1 cells were incubated with various concentrations of clotrimazole (0, 30 and 40 µM) for 24 h and labeled with Annexin V and propidium iodide (PI). (A) Apoptosis of OSCC cells was analyzed by flow cytometry. The bottom right quadrant represents the percentage of early apoptotic cells (Annexin V⁺/PI⁻), whereas the top right quadrant is the percentage of late apoptotic cells (Annexin V⁺/PI⁺). (B) Percentages of cells in apoptosis at each clotrimazole concentration. The results are presented as the mean of three similar experiments. *<i>P</i><0.05; **<i>P</i><0.01 compared with solvent control.</p

Clotrimazole inhibits OSCC cells proliferation.

<p>OSCC cells (CAL27, SCC25, and UM1) were treated with clotrimazole (0–80 µM) for 24 h, 48 h and 72 h, and cell viability was detected using a Cell Counting Kit-8 assay. The results presented as mean ± standard deviation values for three independent experiments.</p

Clotrimazole slows the growth of human OSCC xenograft tumors in nude mice.

<p>A total of 5×10⁶ CAL27 cells/mouse were injected subcutaneously into the back next to the right front limb. When a tumor became palpable, clotrimazole (150 mg/kg/body) was administered intraperitoneally for 2 weeks, 6 times per week, control mice treated with equal volume of peanut oil. (A) Representative photographs of the gross tumors from nude mice treated with clotrimazole or peanut oil. (B) Graphs represent the average tumor volumes of CAL27 xenografts in mice from the control and clotrimazole-treated groups. (C) Graphs represent the average weight of tumors from the control and clotrimazole-treated groups. (D) PCNA expression in tumor tissues was assessed by IHC. The bar graph shows PCNA labeling index (PCI) in twelve tumors per each experimental group. PCI (%)  = positive tumor cells/total tumor cells×100%. (E) Cleaved caspase-3 expression in tumor tissues was assessed by IHC. The bar graph shows cleaved caspase-3 labeling index (CI) in twelve tumors per each experimental group. CI (%)  =  positive tumor cells/total tumor cells ×100%. *<i>P</i><0.05; ** <i>P</i><0.01 compared with control nude mice.</p

Clotrimazole induces G₀/G₁ cell cycle arrest in OSCC cells.

<p>OSCC cells were exposed to various concentrations of clotrimazole (0, 30 and 40 µM) for 24 h. Cell cycle distributions were analyzed by flow cytometry with PI staining. *<i>P</i><0.05, **<i>P</i><0.01 as compared with the CAL27 control cells; # <i>P</i><0.01 as compared with the SCC25 control cells; ‡<i>P</i><0.01 as compared with the UM1 control cells.</p

Clotrimazole inhibits colony formation of OSCC cells.

<p>OSCC cells (CAL27, SCC25, and UM1) grown in 6-well plates (1000 cells/well) were incubated with various concentrations of clotrimazole (0, 10, 20 and 30 µM) for two weeks. Cell colonies were stained and counted as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098885#s2" target="_blank">Methods</a> section. The results presented as mean ± standard deviation values for three independent experiments. *<i>P</i><0.05; **<i>P</i><0.01 compared with solvent control.</p