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31.
Qiyao Li Ying Li Tianliang Min Junyi Gong Lili Du David Lee Phillips Junkai Liu Jacky W. Y. Lam Herman H. Y. Sung Ian D. Williams Ryan T. K. Kwok Chun Loong Ho Kai Li Jianguo Wang Ben Zhong Tang 《Angewandte Chemie (International ed. in English)》2020,59(24):9470-9477
Pathogen infections and cancer are two major human health problems. Herein, we report the synthesis of an organic salt photosensitizer (PS), called 4TPA‐BQ, by a one‐step reaction. 4TPA‐BQ presents aggregation‐induced emission features. Owing to the aggregation‐induced reactive oxygen species generated and a sufficiently small ΔEST, 4TPA‐BQ shows a satisfactorily high 1O2 generation efficiency of 97.8 %. In vitro and in vivo experiments confirmed that 4TPA‐BQ exhibited potent photodynamic antibacterial performance against ampicillin‐resistant Escherichia coli with good biocompatibility in a short time (15 minutes). When the incubation duration persisted long enough (12 hours), cancer cells were ablated efficiently, leaving normal cells essentially unaffected. This is the first reported time‐dependent fluorescence‐guided photodynamic therapy in one individual PS, which achieves ordered and multiple targeting simply by varying the external conditions. 4TPA‐BQ reveals new design principles for the implementation of efficient PSs in clinical applications. 相似文献
32.
Kian Hoong Chai Loong Kong Leong David Shan-Hill Wong De-Hao Tsai Sumathi Sethupathi 《中国化学会会志》2020,67(6):998-1008
The present work studied the effect of different carbon dioxide (CO2) adsorbents on Ni-based dual-function materials (DFMs) for the development of carbon capture and on-site utilization in a reactor at isothermal condition. The DFMs containing Ni functioning as a methanation catalyst with various CO2 adsorbents (i.e., CaO, MgO, K2CO3, or Na2CO3) were prepared on γ-Al2O3 through sequential impregnation. The result indicated that Ni-Na2CO3/γ-Al2O3 had the highest methanation capacity (i.e., 0.1783 mmol/g) and efficiency (i.e., 71.09%) in the CO2 adsorption–methanation test. The CO2 uptake and the subsequent methanation capacity of the Ni-Na2CO3/γ-Al2O3 increased to more than 24 times and more than 17 times, respectively, compared to Ni/γ-Al2O3. The high methanation capacity was correlated to its highest amount of weak basic sites, substantial CO2 capture capacity and capture/release efficiency, and reactivity to H2 at a lower temperature, supported by CO2-TPD, TGA analyses for adsorption or adsorption–desorption at the isothermal condition, and H2-TPRea, respectively. A continuous cyclic CO2 adsorption–methanation was performed by using the Ni-Na2CO3/γ-Al2O3 and Ni-CaO/γ-Al2O3, showing that the CO2 adsorption capacity was stabilized from third cycle onward, whereas the methanation capacity was stabilized at all cycles, indicating the high stability of the DFMs for both CO2 adsorption and subsequent methanation. This work demonstrated successful synthesis of the Ni-based, low-cost, and stable DFMs with the ability to produce methane via the direct capture of CO2. 相似文献
33.
In this study, a bag‐in‐box white wine was stored at 22, 35, and 45 °C for up to 48 days to produce a series of samples that exhibited different enological parameters (absorbance at 420 nm, free SO2, total SO2, total phenol, and total aldehyde). Wine samples were extracted with dichloromethane and analyzed using gas chromatography (GC) to generate volatile fingerprints. Principal component analysis (PCA) score plots of the first three principal components showed grouping trends that were influenced by storage time and temperature. PCA loading plots revealed that changes in chemical profiles were different for wines held at different storage temperatures. Storage time could be predicted accurately by partial least squares (PLS) regression of the GC data. Coefficients of determination (R2) were >0.99, and the standard error of prediction values were 0.4, 0.5, and 1.9 days over the test period of 15, 30, and 48 days, respectively. Using the same GC data with PLS analyses, the enological parameters could be accurately predicted from GC fingerprints, except for the predictions of SO2 in a wine stored at 22 °C and total phenol in a wine stored at 45 °C. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
34.
Sr3In0.9Co1.1O6, isostructural to Ca3Co2O6, is revealed by the study of the phase relations in the system SrO-InO1.5-CoOx (1000 °C). The structure of Sr3In0.9Co1.1O6 is refined by the combination of powder X-ray and neutron diffraction. Sr3In0.9Co1.1O6 crystallizes in a trigonal lattice with the cell parameters a=b=9.59438(3) Å, c=11.02172(4) Å with the space group R-3c. Its structure possesses 1D (In/Co)O3 chains running along the c-axis constructed by alternating face-sharing CoO6 octahedra and (In0.9Co0.1)O6 trigonal prisms. The co-occupation of In3+ and Co3+ at the trigonal prismatic site is evidenced by elementary analysis and determined by the structure refinement. Sr3In0.9Co1.1O6 is paramagnetic, and the susceptibility is consistent with the occupation of Co3+ at 10% of the trigonal prismatic positions in a high spin state (HS, S=2). The HS Co3+ is well separated by diamagnetic CoO6 octahedra and InO6 trigonal prisms and shows a g factor of 2.0 in the magnetic measurements. 相似文献
35.
Hao Jing Zhao Liu Seng How Kuan Sylvia Chieng Chun Loong Ho 《Molecules (Basel, Switzerland)》2021,26(11)
Recently, microbial-based iron reduction has been considered as a viable alternative to typical chemical-based treatments. The iron reduction is an important process in kaolin refining, where iron-bearing impurities in kaolin clay affects the whiteness, refractory properties, and its commercial value. In recent years, Gram-negative bacteria has been in the center stage of iron reduction research, whereas little is known about the potential use of Gram-positive bacteria to refine kaolin clay. In this study, we investigated the ferric reducing capabilities of five microbes by manipulating the microbial growth conditions. Out of the five, we discovered that Bacillus cereus and Staphylococcus aureus outperformed the other microbes under nitrogen-rich media. Through the biochemical changes and the microbial behavior, we mapped the hypothetical pathway leading to the iron reduction cellular properties, and found that the iron reduction properties of these Gram-positive bacteria rely heavily on the media composition. The media composition results in increased basification of the media that is a prerequisite for the cellular reduction of ferric ions. Further, these changes impact the formation of biofilm, suggesting that the cellular interaction for the iron(III)oxide reduction is not solely reliant on the formation of biofilms. This article reveals the potential development of Gram-positive microbes in facilitating the microbial-based removal of metal contaminants from clays or ores. Further studies to elucidate the corresponding pathways would be crucial for the further development of the field. 相似文献
36.
H Sun CL Ho F Ding I Soehano XW Liu ZX Liang 《Journal of the American Chemical Society》2012,134(29):11924-11927
Mellein and the related 3,4-dihydroisocoumarins are a family of natural products with interesting biological properties. The mechanisms of dihydroisocoumarin biosynthesis remain largely speculative today. Here we report the synthesis of mellein by a partially reducing iterative polyketide synthase (PR-PKS) as a pentaketide product. Remarkably, despite the head-to-tail homology shared with several fungal and bacterial PR-PKSs, the mellein synthase exhibits a distinct keto reduction pattern in the synthesis of the pentaketide. We present evidence to show that the ketoreductase (KR) domain alone is able to recognize and differentiate the polyketide intermediates, which provides a mechanistic explanation for the programmed keto reduction in these PR-PKSs. 相似文献
37.
G. Barros C. C. Santos A. P. Ayala I. Guedes L. A. Boatner C.‐K. Loong 《Journal of Raman spectroscopy : JRS》2010,41(6):694-697
Polarized Raman spectroscopy was used to investigate the room‐temperature phonon characteristics of a series of rare‐earth arsenate (REAsO4, RE = Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb, and Lu) single crystals. The Raman data were interpreted in a systematic manner based on the known tetragonal zircon structure of these compounds, and assignments and correlations were made for the observed bands. We found that the wavenumbers of the internal modes of the AsO4 tetrahedron increased with increasing atomic number. This increase seems to be correlated to the contraction of the RE–O bond length. For three out of four lattice wavenumbers observed, this tendency was not nearly so marked as in the case of the internal mode wavenumber. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
38.
G. Barros I. Guedes L. Misoguti S. C. Zilio C.-K. Loong J. Wang X. Hu H. Zhang 《Applied physics. B, Lasers and optics》2009,94(2):221-225
The Z-scan technique is employed to obtain the nonlinear refractive index (n
2) of the Ca4REO(BO3)3 (RECOB, where RE = Gd and La) single crystals using 30 fs laser pulses centered at 780 nm for the two orthogonal orientations
determined by the optical axes (X and Z) relative to the direction of propagation of the laser beam (k//Y// crystallographic b-axis). The large values of n
2 indicate that both GdCOB and LaCOB are potential hosts for Yb:RECOB lasers operating in the Kerr-lens mode locking (KLM)
regime. 相似文献
39.
Kolesnikov AI Zanotti JM Loong CK Thiyagarajan P Moravsky AP Loutfy RO Burnham CJ 《Physical review letters》2004,93(3):035503
Quasi-one-dimensional water encapsulated inside single-walled carbon nanotubes, here referred to as nanotube water, was studied by neutron scattering. The results reveal an anomalously soft dynamics characterized by pliable hydrogen bonds, anharmonic intermolecular potentials, and large-amplitude motions in nanotube water. Molecular dynamics simulations consistently describe the observed phenomena and propose the structure of nanotube water, which comprises a square-ice sheet wrapped into a cylinder inside the carbon nanotube and interior molecules in a chainlike configuration. 相似文献
40.
Ultrasonic velocity and attenuation measurements in AZ91D magnesium (Mg) alloy with dendritic, rosette and globular microstructures were performed at elevated temperatures using a non-contact laser-ultrasonic technique. It was found that the ultrasonic velocity in the globular microstructure and the ultrasonic attenuation in the dendritic microstructure are the highest among the three microstructures. An ultrasonic clad steel buffer rod sensor embedded in the die has been used to monitor the semi-solid die casting process in-line for the AZ91D Mg alloy. This probe monitored the completion of the die filling, the release of the pressure, the opening of the die, part detachment, solidification of the part, the averaged temperature of the die and the part. 相似文献