| 1. |
- Li, Wenjing, et al.
(författare)
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The spatial variation in the effects of air pollution on cardiovascular mortality in Beijing, China
- 2018
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Ingår i: Journal of Exposure Science and Environmental Epidemiology. - : Nature Publishing Group. - 1559-0631 .- 1559-064X. ; 28:3, s. 297-304
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Tidskriftsartikel (refereegranskat)abstract
- Owing to lack of data from multiple air quality monitoring stations, studies about spatial association between concentrations of ambient pollutants and mortality in China are rare. To investigate the spatial variation of association between concentrations of particulate matter less than 10 mu m in aerodynamic diameter (PM10), nitrogen dioxide (NO2) and carbon monoxide (CO) and cardiovascular mortality in Beijing, China, we collected data including daily deaths, concentrations of PM10, NO2 and CO, and meteorological factors from 1 January 2009 to 31 December 2010 in all 16 districts of Beijing. Generalized additive model (GAM) and generalized additive mixed model (GAMM) were used to examine the citywide and district-specific effects of PM10, NO2 and CO on cardiovascular mortality. The citywide effect derived from GAMM was lower than that derived from GAM, and the strongest effects were identified for 2-day moving average lag 0-1. The interquartile increases in concentrations of PM10, NO2 and CO were associated with 2.46 (95% confidence interval (CI), 1.22-3.72), 4.11 (95% CI, 2.82-5.42) and 2.23 (95% CI, 1.14-3.33) percentage increases in daily cardiovascular mortality by GAMM, respectively. The relative risk of each district compared with reference district was generally statistically significant. The death risk associated with air pollutants varies across different geographic districts in Beijing. The data indicate that the risk is high in suburban areas and rural counties. We found significant and spatially varied adverse effects of air pollution on cardiovascular deaths across the rural and urban areas in Beijing.
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| 2. |
- Tian, Xiaohe, et al.
(författare)
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Probe for simultaneous membrane and nucleus labeling in living cells and in vivo bioimaging using a two-photon absorption water-soluble Zn(II) terpyridine complex with a reduced pi-conjugation system
- 2017
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Ingår i: Chemical Science. - : ROYAL SOC CHEMISTRY. - 2041-6520 .- 2041-6539. ; 8:1, s. 142-149
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Tidskriftsartikel (refereegranskat)abstract
- Small, biocompatible and water-soluble molecules with high two-photon absorption (2PA) cross-section values (delta) are in high demand for specific bioimaging applications. Here, two novel terpyridine derivative ligands with donor-acceptor (D-A) (L1) and donor-pi-acceptor (D-pi-A) (L2) models, and their corresponding Zn(II) complexes are designed and characterized. It was found that the two-photon absorption cross section values (d) in the near-infrared region (NIR, about 800 nm) are significantly enhanced for complexes 1 and 2 compared to their free D-A type ligand L1, while those of complexes 3 and 4 were greatly decreased relative to their free ligand L2, thus confirming that the smaller ligand (D-A type) displays a suitable Turn-ON fluorescence pair for two-photon fluorescence microscopy (2PFM). Firstly, the potential of simultaneously labeling a live cell plasma membrane and nucleus using complex 1 is demonstrated. In addition, live larval and adult zebrafish incubated with an optimal concentration of 1 demonstrated clear brain uptake. Lastly and importantly, using such a probe to visualize the blood-brain- barrier (BBB) capillary endothelial cells and penetrate the BBB into the central nervous system (CNS) intravenously in a mouse model is also explored.
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| 3. |
- Wang, Hui, et al.
(författare)
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Mitochondria-targeted iridium (III) complexes as two-photon fluorogenic probes of cysteine/homocysteine
- 2018
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Ingår i: Sensors and actuators. B, Chemical. - : ELSEVIER SCIENCE SA. - 0925-4005 .- 1873-3077. ; 255, s. 408-415
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Tidskriftsartikel (refereegranskat)abstract
- Fluorescent imaging of cysteine (Cys) and homocysteine (Hcy) is crucial to understand sulphur metabolism in living cells. Whereas two-photon active cyclometalated Ir(III) complex for detecting Cys/Hcy has been rarely reported. Herein, two novel cyclometalated iridium (III) complexes Ir1-1r2 with different electron-donor were designed, synthesized and fully characterized as well as confirmed by single-crystal X-ray diffraction analysis, which could selectively react with Cys/Hcy, accompanying with an obvious one- and two-photon fluorescence enhancement in vitro. The mechanism for sensing Cys/Hcy was further analyzed in detail by mass spectra and time-dependent density functional theory calculations. It was found that Ir2, bearing ester group, exhibited higher performance on the selective detection of Cys and Hcy compared to In. Notably, the two-photon action cross-section value in the near-infrared region (similar to 800 nm) of Ir2 is significantly enhanced upon the addition of Cys/Hcy. Further application to cellular imaging indicated that Ir2 is membrane permeable and capable of monitoring the changes of intracellular mitochondrial Cys/Hcy. These results support that such two-photon active complexes might provide a promising platform for the detection of mitochondrial Cys/Hcy in living biological systems. (C) 2017 Published by Elsevier B.V.
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| 4. |
- Wang, Hui, et al.
(författare)
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Two-Photon Active Organotin(IV) Carboxylate Complexes for Visualization of Anticancer Action
- 2017
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Ingår i: ACS Biomaterials Science & Engineering. - : AMER CHEMICAL SOC. - 2373-9878. ; 3:5, s. 836-842
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Tidskriftsartikel (refereegranskat)abstract
- It is still a challenge that organotin(IV) carboxylate complexes with high-performance two-photon activity for cancer therapy. At present work, two novel organotin carboxylate complexes LSn1 and LSn2, containing coumarin moiety, were rationally designed for two-photon fluorescent imaging and anticancer purpose. The complexes possessed large two-photon action cross-sections and high quantum yields. Living cells evaluation revealed that complexes LSn1 and LSn2 exhibited good biocompatibility and deep tissue penetration over femtosecond laser with wavelength of 840 nm. Furthermore, the antitumor active and as well as possible mechanism of complexes LSn1 and LSn2 have been investigated systematically. The results indicated that complexes LSn1 and LSn2 could induce apoptotic cell death through a mitochondria] dysfunction and ROS elevation pathway. The present work provides a strategy for rationally designing organotin(IV) carboxylate complexes with two-photon activity and antitumor activity.
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| 5. |
- Zhang, Qiong, et al.
(författare)
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A series of Zn(II) terpyridine complexes with enhanced two-photon-excited fluorescence for in vitro and in vivo bioimaging
- 2015
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Ingår i: Journal of materials chemistry. B. - : ROYAL SOC CHEMISTRY. - 2050-750X .- 2050-7518. ; 3:36, s. 7213-7221
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Tidskriftsartikel (refereegranskat)abstract
- It is still a challenge to obtain two-photon excited fluorescent bioimaging probes with intense emission, high photo-stability and low cytotoxicity. In the present work, four Zn(II)-coordinated complexes (1-4) constructed from two novel D-A and D-p-A ligands (L-1 and L-2) are investigated both experimentally and theoretically, aiming to explore efficient two-photon probes for bioimaging. Molecular geometry optimization used for theoretical calculations is achieved using the crystallographic data. Notably, the results indicate that complexes 1 and 2 display enhanced two-photon absorption (2PA) cross sections compared to their corresponding D-A ligand (L1). Furthermore, it was found that complex 1 has the advantages of moderate 2PA cross section in the near-infrared region, longer fluorescence lifetime, higher quantum yield, good biocompatibility and enhanced two-photon excited fluorescence. Therefore, complex 1 is evaluated as a bioimaging probe for in vitro imaging of HepG2 cells, in which it is observed under a two-photon scanning microscope that complex 1 exhibits effective co-staining with endoplasmic reticulum (ER) and nuclear membrane; as well as for in vivo imaging of zebrafish larva, in which it is observed that complex 1 exhibits specificity in the intestinal system.
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| 6. |
- Zhang, Qiong, et al.
(författare)
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Design, synthesis, linear and nonlinear photophysical properties of novel pyrimidine-based imidazole derivatives
- 2016
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Ingår i: New Journal of Chemistry. - : ROYAL SOC CHEMISTRY. - 1144-0546 .- 1369-9261. ; 40:4, s. 3456-3463
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Tidskriftsartikel (refereegranskat)abstract
- Novel donor-pi-acceptor (D-pi-A) and donor-pi-acceptor-pi-donor (D-pi-A-pi-D) type pyrimidine imidazole derivatives with flexible ether chains (L1 and L2) have been efficiently synthesized through improved Knoevenagel condensation and Ullmann reactions with high yields. Based on systematic photophysical investigations and theoretical calculations, the structure-property relationships can be described as follows: (1) the linear and nonlinear optical properties of the target chromophores change regularly with increasing the number of branches and the polarity of the solvents. (2) The single-substituted chromophore L2 exhibited a remarkable negative solvato-kinetic effect, while the double-substituted chromophore L1 showed a positive solvato-kinetic effect. Significant bathochromic shifting of the emission spectra and larger Stokes shifts were observed in polar solvents. (3) The two-photon absorption (TPA) cross-section results further demonstrated that their TPA cross section values (delta) increase notably with increasing branch number, and the presence of high pi-delocalization could induce large size-scalable TPA enhancements. (4) By comprehensively considering the optical performance, cytotoxicity and solubility, L1 was identified as the better candidate for living cell (HepG2) imaging.
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| 7. |
- Zhang, Qiong, et al.
(författare)
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NIR-region two-photon fluorescent probes for Fe3+/Cu2+ ions based on pyrimidine derivatives with different flexible chain
- 2016
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Ingår i: Sensors and actuators. B, Chemical. - : ELSEVIER SCIENCE SA. - 0925-4005 .- 1873-3077. ; 222, s. 574-578
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Tidskriftsartikel (refereegranskat)abstract
- Two novel NIR-region two-photon fluorescent probes CCP and COP, show strong fluorescence quenching and good ratiometric responses toward Fe3+ and Cu2+, respectively; and their two-photon fluorescence are reversible by the subsequent addition of EDTA. CCP and COP are valuable candidates for two-photon imaging in the biological transparency window. (C) 2015 Elsevier B.V. All rights reserved.
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| 8. |
- Zhang, Qiong, et al.
(författare)
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Nonlinear optical response and two-photon biological applications of a new family of imidazole-pyrimidine derivatives
- 2016
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Ingår i: Dyes and pigments. - : ELSEVIER SCI LTD. - 0143-7208 .- 1873-3743. ; 126, s. 286-295
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Tidskriftsartikel (refereegranskat)abstract
- A series of novel D-pi-A type two-photon absorption (2PA) imidazole-pyrimidine derivatives (EX-1 similar to EX-4) have been synthesized and characterized, with EX-1 was crystallography confirmed. Based on systematic photophysical investigations, the structure property relationships can be drawn as follows: (1) Both theoretical and experimental studies indicated that the different donor groups have large influences on the optical properties. (2) The 2PA cross-section values (sigma) were obtained both by Z-Scan and two photon excited fluorescence (2PEF) measurements. 2PA cross sections show an increasing trend with increasing electron-donating strength and the number of branches. (3) Comprehensively considered the optical performance, molecular volume, cytotoxicity and solubility, EX-1 and EX-2 were identified to be the best candidates for living cells (HepG2) imaging. Moreover, the 2PA excitable features of EX-1 and EX-2 are capable of imaging in fresh mouses liver tissues with a depth of ca. 70 mu m. (C) 2015 Elsevier Ltd. All rights reserved.
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