Photostability Enhancement of Fluorenone-Based Two-Photon Fluorescent Probes for Cellular Nucleus Monitoring and Imaging

A series of fluorenone-based two-photon fluorescent probes with high photostability for nucleus imaging are prepared and developed. The one- and two-photon photophysical properties exhibit these new probes possess 0.448–0.634 of fluorescence quantum yields and 469–495 GM of two-photon absorption cross sections at 800 nm femtosecond laser excitation. The luminescence “turn-on” experiment in buffer solutions indicates that 35-fold of fluorescence intensity and 68-fold fluorescence quantum yield enhancement appear between new probes and calf thymus DNA. In the nuclear double-staining experiment, the high mean colocalization coefficients of 0.92–0.96 between new probes and nuclear labeling dye Hoechst 33342 are acquired, demonstrating excellent nuclear localization in 3T3 cells. The counterstain studies by introducing commercial mitochondrial staining reagent MTR and nuclear staining dye DAPI further show good membrane permeability and counterstain compatibility in multicolor cell labeling application. The photostability studies show that 3000 s of observation time and 0.028%/s–0.03%/s of mean fluorescence attenuation rates under persistent laser irradiation in two-photon nuclear imaging are achieved. Meanwhile, the cause of fluorescence attenuation in the photostability test for cellular nuclei monitoring are discussed as well

Manipulating Polyaniline Fibrous Networks by Doping Tetra-β-carboxyphthalocyanine Cobalt(II) for Remarkably Enhanced Ammonia Sensing

Manipulating the morphology and protonic acid doping of polyaniline (PANI) is significant for optimizing its NH₃-sensing. Herein, tetra-β-carboxy­phthalo­cyanine cobalt­(II) (TcPcCo) acted as the dopant and structure-directing agent simultaneously to fabricate the uniform fibrous network-like PANI (PANI-TcPcCo hybrids) by a one-step polymerization at low temperature. During the reaction process, the protonic acid groups in TcPcCo not only induced the aniline monomers polymerizing into one-dimensional nanofibers (consist of both solid and hollow cylinders) with abundant tiny protuberances on the surface but also successfully doped into PANI. The resulting PANI-TcPcCo hybrids displayed the enhancement in terms of the good conductivity, the large gas adsorption capacity, and the unobstructed channels for the electron and gas transport. The central metal atoms of TcPcCo present the strong and selective affinity to NH₃. Meanwhile, the deep-seated conversion of PANI’s molecular structure after exposure in NH₃ could occur due to the presence of TcPcCo. Thus, the PANI-2.5TcPcCo sensor showed the excellent NH₃-sensing performance at room temperature, including an ultrahigh and fast response (802.7% and ∼17.0 s for 100 ppm of NH₃), a very low detection limit of 10 ppb (about 5000 parts of human olfaction limit of detection, 55 ppm), and superior NH₃-sensing stability and selectivity. The strategy developed here provides a reliable and valid way to synthesize functional PANI-based hybrids with unique morphology and appropriate doping, which are able to be extended to other areas

Additional file 1 of Comparison of self-efficacy among graduate teaching assistants before and after training

Supplementary Material

A pH-Responsive Yolk-Like Nanoplatform for Tumor Targeted Dual-Mode Magnetic Resonance Imaging and Chemotherapy

Incorporation of T₁ and T₂ contrast material in one nanosystem performing their respective MR contrast role and simultaneously serving as an efficient drug delivery system (DDS) has a significant potential application for clinical diagnosis and chemotherapy of cancer. However, inappropriate incorporation always encountered many issues, such as low contact area of T₁ contrast material with water-proton, inappropriate distance between T₂ contrast material and water molecule, and undesirable disturbance of T₂ contrast material for T₁ imaging. Those issues seriously limited the T₁ or T₂ contrast effect. In this work, we developed a yolk-like Fe₃O₄@Gd₂O₃ nanoplatform functionalized by polyethylene glycol and folic acid (FA), which could efficiently exert their tumor targeted T₁–T₂ dual-mode MR imaging and drug delivery role. First, this nanoplatform possessed a high longitudinal relaxation rate (<i>r</i>₁) (7.91 mM^–1 s^–1) and a stronger transverse relaxation rate (<i>r</i>₂) (386.5 mM^–1 s^–1) than that of original Fe₃O₄ (268.1 mM^–1 s^–1). Second, cisplatin could be efficiently loaded into this nanoplatform (112 mg/g) and showed pH-responsive release behavior. Third, this nanoplatform could be effectively internalized by HeLa cells with time and dosage dependence. Fourth, the FA receptor-mediated nanoplatform displayed excellent T₁–T₂ dual mode MR contrast enhancement and anticancer activity both <i>in vitro</i> and <i>in vivo</i>. Fifth, no apparent toxicity for vital organs was observed with systemic delivery of the nanoplatform <i>in vivo</i>. Thus, this nanoplatform could be a potential nanotheranostic for tumor targeted T₁–T₂ dual-mode MR imaging and chemotherapy

Partial correlations between pack-years of smoking and BMI-GRS.

<p>Partial correlations between pack-years of smoking and BMI-GRS.</p

Partial correlations between BMI and pack-years of smoking by smoking status.

<p>Partial correlations between BMI and pack-years of smoking by smoking status.</p

Twelve possbile directed acyclic graphs (DAGs) of one SNP, BMI and pack-years (PY) of smoking.

<p>Possible DAGs between one SNP, BMI and PY. The DAGs are categorized into 4 groups. SNPs in Category 1 (DAGs of 1, 2, and 3) do not have effects on either BMI or pack-years. SNPs in Category 2 (DAGs of 4, 5, and 6) have direct effects on BMI, but not PY. SNPs in Category 3 (DAGs of 7, 8, and 9) have direct effects on PY, but not BMI. SNPs in Category 4 (DAGs of 10, 11, and 12) have pleiotropic effects on BMI and PY. ≡ represents models that are not differentiable.</p

The Z statistics for associations of 241 SNPs with BMI, pack-years of smoking, and smoking.

<p>The vertical axis represents Z scores for associations of SNPs with pack-years of smoking or smoking. The horizontal axis represents Z scores for associations of SNPs with BMI. All Z scores were adjusted by age, sex, study sites, genetic principal components and lung cancer disease status. The blue dots were SNPs that were determined to be pleiotropic with further validation in TAG.</p

Adjusted means of the BMI-GRS (95% CIs) by BMI category after adjustment for age, sex, study sites, genetic principal components, smoking status, and pack-years of smoking.

<p>Bar represents mean±s.d.</p

Adjusted means of BMI (95% CIs) for never-smokers, ex-smokers, and current smokers with adjustment for age, sex, and study sites.

<p>Bar represents mean±s.d.</p