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41.
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Rishikesh Pandey Renjie Zhou Rosalie Bordett Ciera Hunter Kristine Glunde Ishan Barman Tulio Valdez Christine Finck 《Journal of biophotonics》2019,12(4)
Label‐free quantitative imaging is highly desirable for studying live cells by extracting pathophysiological information without perturbing cell functions. Here, we demonstrate a novel label‐free multimodal optical imaging system with the capability of providing comprehensive morphological and molecular attributes of live cells. Our morpho‐molecular microscopy (3M) system draws on the combined strength of quantitative phase microscopy (QPM) and Raman microscopy to probe the morphological features and molecular fingerprinting characteristics of each cell under observation. While the commonr‐path geometry of our QPM system allows for highly sensitive phase measurement, the Raman microscopy is equipped with dual excitation wavelengths and utilizes the same detection and dispersion system, making it a distinctive multi‐wavelength system with a small footprint. We demonstrate the applicability of the 3M system by investigating nucleated and nonnucleated cells. This integrated label‐free platform has a promising potential in preclinical research, as well as in clinical diagnosis in the near future. 相似文献
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The roles of veratryl alcohol and nonionic surfactant in the oxidation of phenolic compounds by lignin peroxidase 总被引:1,自引:0,他引:1
Huang X Wang D Liu C Hu M Qu Y Gao P 《Biochemical and biophysical research communications》2003,311(2):491-494
Veratryl alcohol (VA) at higher concentration stimulated the lignin peroxidase (LiP)-catalyzed oxidation of phenolic compounds remarkably. This novel phenomenon was due to its competition with the phenols for the active site of the enzyme and to the high reactivity of the formed cation radical of VA (VA+*) which resulted in an additional oxidation of the phenols. The influence of the nonionic surfactant Tween 80 on the VA-enhanced LiP-catalyzed oxidation of phenols depended on its concentration. At lower concentration it had a small synergetic effect but at higher concentration it decreased the initial rate. Studies of the capillary electrophoretic behavior of LiP in the presence of Tween 80 showed that this effect was caused by the surfactant aggregation on LiP which, at higher surfactant concentrations, might impede the access of VA to its binding site on LiP and, consequently, the VA+* formation. 相似文献
45.
Turcotte LP Swenberger JR Tucker MZ Yee AJ Trump G Luiken JJ Bonen A 《Molecular and cellular biochemistry》2000,210(1-2):53-63
Studies show that uptake of long-chain fatty acids (LCFA) across the plasma membranes (PM) may occur partly via a carrier-mediated process and that the plasma membrane fatty acid-binding protein (FABPPM) may be a component of this system. To test the hypothesis that FABPPM is involved in transsarcolemmal transport of LCFA in muscle, we measured palmitate uptake in giant sarcolemmal vesicles and palmitate binding to PM proteins in rat muscles, (1) in the presence of increasing amounts of unbound palmitate and (2) in the absence or presence of antibody to FABPPM. Both palmitate uptake and binding were found to be saturable functions of the unbound palmitate concentration with calculated Vmax values of 10.5 ± 1.2 pmol/mg protein/15 sec and 45.6 ± 2.9 nmol/mg protein/15 min and Km values of 12.8 ± 3.8 and 18.4 ± 1.8 nmol/L, respectively. The Vmax values for both palmitate uptake and binding were significantly decreased by 75-79% in the presence of a polyclonal antibody to the rat hepatic FABPPM. Antibody inhibition was found to be dose-dependent and specific to LCFA. Glucose uptake was not affected by the presence of the antibody to FABPPM. Palmitate uptake and binding were also inhibited in the presence of trypsin and phloretin. These results support the hypothesis that transsarcolemmal LCFA transport occurs in part by a carrier-mediated process and that FABPPM is a component of this process in muscle. 相似文献
46.
The number of people using mobile phones has dramatically increased. At the same time, many people are unsettled about the potential health effects from the electromagnetic fields generated by mobile phone base stations. Research indicates that the risks associated with base stations are perceived differently by experts, laypeople, and base station opponents. Using a free association method, we analyzed these differences in more detail. In our first study, we found no difference between experts and laypeople but a marked distinction in the associations of opponents as opposed to the first two groups. The prevalence of free associations in a large random sample from the general population was explored via correspondence analysis in the second study. People who assign high risks to mobile communication had different, more negative associations in mind (e.g., “senselessness,” “hazard”) compared to people with low risk-perception (e.g., “mast,” “acceptance”). Our research is in line with the assumption that the affect heuristic guides risk and benefit assessments, and highlights the role of affect in risk perception and communication. 相似文献
47.
Molecular dynamics simulations of triclinic hen egg white lysozyme in aqueous solution were performed to calculate the intrinsic pKas of 14 ionizable residues. An all-atom model was used for both solvent and solute, and a single 180 ps simulation in conjunction with a Gaussian fluctuation analysis method was used. An advantage of the Gaussian fluctuation method is that it only requires a single simulation of the system in a reference state to calculate all the pKas in the protein, in contrast to multiple simulations for the free energy perturbation method. pKint shifts with respect to reference titratable residues were evaluated and compared to results obtained using a finite difference Poisson-Boltzmann (FDPB) method with a continuum solvent model; overall agreement with the direction of the shifts was generally observed, though the magnitude of the shifts was typically larger with the explicit solvent model. The contribution of the first solvation shell to the total charging free energies of the titratable groups was explicitly evaluated and found to be significant. Dielectric shielding between pairs of titratable groups was examined and found to be smaller than expected. The effect of the approximations used to treat the long-range interactions on the pKint shifts is discussed. © 1994 Wiley-Liss, Inc. 相似文献
48.
High Performance Flexible Supercapacitor Electrodes Composed of Ultralarge Graphene Sheets and Vanadium Dioxide 下载免费PDF全文
Little is known regarding the effect of the graphene lateral size on the electrochemical performance of hybrid graphene electrode. This work examines the electrochemical performance of a flexible hybrid supercapacitor electrode composed of ultralarge graphene oxide (UGO; mean lateral size of 47 ± 22 μm) and vanadium dioxide (VO2) nanobelts, referring to a reference electrode composed of small scale graphene oxide (SGO; mean lateral size of 0.8 ± 0.5 μm) and VO2.Thermal treatment converts UGO/VO2 and SGO/VO2 to URGO/VO2 (denoted VURGO) and SRGO/VO2 (denoted VSRGO) electrodes, respectively. The sheet resistance of the VURGO film (0.57 ± 0.03 kΩ sq.–1) was two orders of magnitude lower than that of the VSRGO (55.74 ± 9.35 kΩ sq.–1). The VURGO hybrid electrode showed a specific capacitance of 769 F g?1, which was significantly better than the corresponding values for the VSRGO electrode (385 F/g). These results support the notion that the use of ultralarge graphene sheets (≈22 500 μm2) lowers the intersheet resistance due to the presence of fewer intersheet tunneling barriers. This article highlights the potential utility of URGO (as a conductive support) in hybrid electrode containing VO2 nanobelts for high performance flexible hybrid supercapacitor. 相似文献
49.
Mitigation of ammonia inhibition by internal dilution in high‐rate anaerobic digestion of food waste leachate and evidences of microbial community response 下载免费PDF全文
50.
The long-lived, light-induced radical YD• of the Tyr161 residue in the D2 protein of Photosystem II (PSII) is known to magnetically interact with the CaMn4 cluster, situated ∼ 30 Å away. In this study we report a transient step-change increase in YD• EPR intensity upon the application of a single laser flash to S1 state-synchronised PSII-enriched membranes from spinach. This transient effect was observed at room temperature and high applied microwave power (100 mW) in samples containing PpBQ, as well as those containing DCMU. The subsequent decay lifetimes were found to differ depending on the additive used. We propose that this flash-induced signal increase was caused by enhanced spin relaxation of YD• by the OEC in the S2 state, as a consequence of the single laser flash turnover. The post-flash decay reflected S2 → S1 back-turnover, as confirmed by their correlations with independent measurements of S2 multiline EPR signal and flash-induced variable fluorescence decay kinetics under corresponding experimental conditions. This flash-induced effect opens up the possibility to study the kinetic behaviour of S-state transitions at room temperature using YD• as a probe. 相似文献