Synthesis and Characterization of Multiple Stimuli-Responsive Fluorescent Polymer Hydrogels Based on Terpyridine and N-Isopropylacrylamide.

A series of stimuli-responsive fluorescent hydrogels were successfully synthesized via micelle radical copolymerization of hydrophilic acrylamide (AM), hydrophobic chromophore terpyridine-based monomer (TPY), and N-isopropylacrylamide (NIPAM). These hydrogels presented blue emissions (423-440 nm) under room temperature, which is caused by the π-π* transition of the conjugated structures. Once the ambient temperature was increased to 55 °C, the fluorescence color changed from blue (430 nm) to pink (575 nm) within 10 min, subsequently to yellow (535 nm), and eventually back to pink. The thermal-responsive properties are attributed to the transition of the TPY units from unimer to dimer aggregation via the intermolecular charge transfer complex at high temperatures. The hydrogels showed pH-responsive properties. The emission peak of the hydrogel exhibited a blue shift of ~54 nm from neuter conditions to acidic conditions, while a 6 nm red shift to an alkaline environment was observed. The hydrogels demonstrated an obvious change in fluorescence intensity and wavelength upon adding different metal ions, which is caused by the coordination between the terpyridine units incorporated on the backbones and the metal ions. As a consequence, the hydrogels presented a sharp quenching fluorescence interaction with Fe2+, Fe3+, Cu2+, Hg2+, Ni2+, and Co2+, while it exhibited an enhanced fluorescence intensity interaction with Sn2+, Cd2+, and Zn2+. The microstructural, mechanical, and rheological properties of these luminescent hydrogels have been systematically investigated.

Inhibitory Effect of Fingolimod on Head and Neck Squamous Cell Carcinoma and Its Mechanism: Gene Set Enrichment Analysis.

This study aimed to clarify the therapeutic effect of Fingolimod on head and neck squamous cell carcinoma (HNSC) and initially explore its mechanism through data mining, clinical sample analysis and basic experiments. The normalized Enrichment Score (NES) of Fingolimod in tumor tissues was obtained by SwissTargetPrediction and The Cancer Genome Atlas (TCGA) database. IC50 (50% inhibitory concentration) of Fingolimod for HNSC was verified based on the Genomics of Drug Sensitivity in Cancer (GDSC) database. SCC9 cells were cultured in vitro for the application of Fingolimod. Cell proliferation was determined by the Cell Counting Kit-8 (CCK-8). The expression levels of genes were determined by reverse transcription-polymerase chain reaction (RT-PCR). The molecular regulatory mechanism of Fingolimod acting on HNSC was analyzed with WebGestalt. Cyclin expression was determined by Western blot assay. The key targeted genes for Fingolimod against HNSC were screened with the TCGA database and verified in clinical samples. Gene Set Enrichment Analysis (GSEA) showed the highest NES score in HNSC (NES=1.53, P<0.05). GDSC showed the lowest IC50 in Fingolimod SSC9 cells. IC50 calculated by the cell activity detected by CCK8 was 4.34 µmol/L, and RT-PCR showed significantly suppressed expression of proliferation-related gene Ki-67 after adding Fingolimod (P<0.05). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the targeted genes for Fingolimod were mainly enriched in cell cycle-related pathways. Western blot showed significantly decreased cyclin expression in SSC9 cells after the treatment with Fingolimod (P<0.05). TCGA analysis revealed that PLK1 is a key targeted gene for Fingolimod in the treatment of HNSC. RT-PCR showed the significantly increased activity of SCC9 after over-expressing PLK1, and the increased proliferation and anti-apoptosis abilities (P<0.05), as well as the significantly inhibited expression of Ki-67 and Bcl-2 after adding Fingolimod. Fingolimod can promote the arrest in G0/G1 of SCC9 cells, and PLK1 is a key targeted gene for the treatment of HNSC. Fingolimod can inhibit cell proliferation caused by PLK1 over-expression.

Data-based fault-tolerant control for affine nonlinear systems with actuator faults.

This paper investigates the fault-tolerant control (FTC) problem for unknown nonlinear systems with actuator faults including stuck, outage, bias and loss of effectiveness. The upper bounds of stuck faults, bias faults and loss of effectiveness faults are unknown. A new data-based FTC scheme is proposed. It consists of the online estimations of the bounds and a state-dependent function. The estimations are adjusted online to compensate automatically the actuator faults. The state-dependent function solved by using real system data helps to stabilize the system. Furthermore, all signals in the resulting closed-loop system are uniformly bounded and the states converge asymptotically to zero. Compared with the existing results, the proposed approach is data-based. Finally, two simulation examples are provided to show the effectiveness of the proposed approach.

A high-affinity anti-salbutamol monoclonal antibody: key to a robust lateral-flow immunochromatographic assay.

Among the components that make up a lateral-flow immunochromatographic assay (ICA), antibody is the key. In this paper, salbutamol (SAL) as a model analyte was meticulously designed to prepare immunogen and coating antigen in distinctly different ways. Four hybridoma cell lines were prepared and identified. Among them, C9 had highest affinity, best dose-response behavior, lowest limit of detection, and highest specificity and was chosen to be labeled with colloidal gold as the detector reagent and applied on the conjugate pad. Goat anti-mouse antibody and SAL-BSA conjugate were sprayed on a nitrocellulose membrane as test line and control line, respectively. Under the optimized conditions, the ICA strip was constructed based on a binding inhibition format. Color intensity on the test line was visually distinguishable from that of the negative sample within 5 min, with the visual detection limit of 1 ngml(-1) in phosphate-buffered saline. Cross-reactions with other ß-agonists were not found (<1%). The results from ICA were in a good agreement with those obtained by enzyme-linked immunosorbent assay. The developed ICA has potential as a useful on-site screening tool for SAL in swine urine.

Identification of differentially expressed genes in human lymphoblastoid cells exposed to irradiation and suppression of radiation-induced apoptosis with antisense oligonucleotides against caspase-4.

To identify candidate genes in response to ionizing radiation (IR) and discover new targets for basic research and radiation protection, whole human genome bioarrays were used to examine gene expression profiles in human lymphoblastoid AHH-1 cells exposed to IR. The results were confirmed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). In addition, the effects of ionizing radiation on cell growth, cell cycles and apoptosis were also examined. The microarray analysis revealed a set of IR responsive genes, including 906 genes at 4 hours and 789 genes at 24 hours after exposure to 5 Gy IR. The processes of cell cycles, apoptosis, signal transduction, and DNA repair involved a high percentage of IR responsive genes, among which, caspase-4 was most strongly induced by irradiation. Consistent with this, downregulation of caspase-4 expression by antisense oligonucleotides significantly increased cell viability and protected cells from undergoing apoptosis induced by IR. Taken together, the results suggested that caspase-4 plays an important role in radiation-induced apoptosis.

[Fractal structure of Abies fabri, dominant tree species in dark coniferous forest at the upper reach of Yangtze River].

Based on the theory of fractal geometry, branching patterns of primitive Abies fabri in the dark coniferous forest ecosystem at the upper reach of Yangtze River were studied. The results showed that the maximum crown width was appeared at inferior 20% of the crown height, and its volume could be simulated by the combination of a round table and a cone. The surface of the crown and their branching patterns of Abies fabri had the common typical fractal characters, the fractal dimensions (FD) were 2.3232 and 1.8119, and the correlation coefficient was 0.99.

[Plot analysis in the dark coniferous ecosystem using GPS and GIS techniques].

It is generally difficult to survey in primary forests located on high-altitude region. However, it is convenient to identify and to recognize plots accompanied by GPS and GIS techniques, which can also display the spatial pattern of arbors precisely. Using the method of rapid-static positioning cooperated with tape-measure, it is concluded that except some points, the positioning was relatively precise, the average value of RMS was 2.84, variance was 2.96, and delta B, delta L, and delta H were 1.2, 1.2, and 4.3 m with their variances being +/- 0.6, +/- 1.1, and +/- 21.1, respectively, which could meet the needs of forestry management sufficiently. Accompanied by some other models, many ecological processes under small and even medium scale, such as the dynamics of gap succession, could also be simulated visually by GIS. Therefore, the techniques of "2S" were patent for forest ecosystem management under the fine scale, especially in the area of high altitude.

[Improvement and application of digitized measure on shelterbelt porosity].

Based on the lots of investigation on farmland shelterbelts, we used digital camera to take pictures of shelterbelt and apply CIAS software to improve "digital image processing" for determining shelterbelt porosity so as to thoroughly analyze the rule of porosity in farmland shelterbelts. Compared with the old digital image processing, the improved method possesses high accuracy, and it is more economical and more convenient to apply. The relationship between porosity of shelterbelts (beta) and relative clear bole height (x) can be expressed as beta = 0.672x0.469 (r = 0.9851, r0.01 = 0.4073, 0 < or = beta < or = 1) in the leaf period; and beta = 1.0681x0.4304 (r = 0.9763, r0.01 = 0.4073, 0 < or = beta < or = 1) in the defoliation period. beta varies with the stand age (a), taking the form of parabola, which can be expressed as beta = 0.0009a2 - 0.0364a + 0.6828 (0 < or = beta < or = 1). Porosity at cross-section of shelterbelt can be used as an auxiliary index to evaluate the structure of belts. The calculation method of shelterbelt porosity of mixed shelterbelt can be expressed as beta = (beta 1n1 + beta 2n2)/(n1 + n2). Among the popular, willow and elm pure shelterbelts with same disposition, popular shelterbelt structure is the best, with beta PPP < beta SSS < beta UUU, while the triangle disposition is better than the rectangle one among the same tree species. UPPU and SPPS of mixed structure have the optimal effect in popular-willow-elm mixed shelterbelts.