The thermodynamics of isolated horizons in loop quantum gravity

The statistical mechanical calculation of the thermodynamical properties of non-rotating isolated horizons are studied in the loop quantum gravity framework. By employing the Hawking temperature and horizon mass of isolated horizons as physical inputs, the microcanonical ensemble associated with the system are well established. As a result, the black hole entropy and other thermodynamical quantities can be computed and consistent with well-known Hawking's semiclassical analysis. Moreover, the value of the Immirzi parameter of loop quantum gravity for {higher dimensional case and 4-dimensional U(1) case are} also obtained.Comment: 9 pages, 1 figure;V2, 12 pages, U(1) group case in 4 dimensions is included, figure update

Metabolic profile, bioavailability and toxicokinetics of zearalenone-14-glucoside in rats after oral and intravenous administration by liquid chromatography high-resolution mass spectrometry and tandem mass spectrometry

Zearalenone-14-glucoside (ZEN-14G), a key modified mycotoxin, has attracted a great deal of attention due to the possible conversion to its free form of zearalenone (ZEN) exerting toxicity. In this study, the toxicokinetics of ZEN-14G were investigated in rats after oral and intravenous administration. The plasma concentrations of ZEN-14G and its major five metabolites were quantified using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The data were analyzed via non-compartmental analysis using software WinNonlin 6.3. The results indicated that ZEN-14G was rapidly hydrolyzed into ZEN in vivo. In addition, the major parameters of ZEN-14G following intravenous administration were: area under the plasma concentration-time curve (AUC), 1.80 h.ng/mL; the apparent volume of distribution (V-Z), 7.25 L/kg; and total body clearance (CL), 5.02 mL/h/kg, respectively. After oral administration, the typical parameters were: AUC, 0.16 h.ng/mL; V-Z, 6.24 mL/kg; and CL, 4.50 mL/h/kg, respectively. The absolute oral bioavailability of ZEN-14G in rats was about 9%, since low levels of ZEN-14G were detected in plasma, which might be attributed to its extensive metabolism. Therefore, liquid chromatography high-resolution mass spectrometry (LC-HRMS) was adopted to clarify the metabolic profile of ZEN-14G in rats' plasma. As a result, eight metabolites were identified in which ZEN-14-glucuronic acid (ZEN-14GlcA) had a large yield from the first time-point and continued accumulating after oral administration, indicating that ZEN-14-glucuronic acid could serve a potential biomarker of ZEN-14G. The obtained outcomes would prompt the accurate safety evaluation of ZEN-14G

Regulation of dopamine transporter activity by carboxypeptidase E

<p>Abstract</p> <p>Background</p> <p>The dopamine transporter (DAT) plays a critical role in terminating the action of dopamine by rapid reuptake into the presynaptic neuron. Previous studies have revealed that the DAT carboxyl terminus (DAT-CT) can directly interact with other cellular proteins and regulate DAT function and trafficking.</p> <p>Results</p> <p>Here, we have identified that carboxypeptidase E (CPE), a prohormone processing exopeptidase and sorting receptor for the regulated secretory pathway, interacts with the DAT-CT and affects DAT function. Mammalian cell lines coexpressing CPE and DAT exhibited increased DAT-mediated dopamine uptake activity compared to cells expressing DAT alone. Moreover, coexpression of an interfering DAT-CT minigene inhibited the effects of CPE on DAT. Functional changes caused by CPE could be attributed to enhanced DAT expression and subsequent increase in DAT cell surface localization, due to decreased DAT degradation. In addition, CPE association could reduce the phosphorylation state of DAT on serine residues, potentially leading to reduced internalization, thus stabilizing plasmalemmal DAT localization.</p> <p>Conclusion</p> <p>Taken together, our results reveal a novel role for CPE in the regulation of DAT trafficking and DAT-mediated DA uptake, which may provide a novel target in the treatment of dopamine-governed diseases such as drug addiction and obesity.</p

Optimization of terrestrial ecosystem model parameters using atmospheric CO2 concentration data with the Global Carbon Assimilation System (GCAS)

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Biogeosciences 122 (2017): 3218–3237, doi:10.1002/2016JG003716.The Global Carbon Assimilation System that assimilates ground-based atmospheric CO2 data is used to estimate several key parameters in a terrestrial ecosystem model for the purpose of improving carbon cycle simulation. The optimized parameters are the leaf maximum carboxylation rate at 25°C (V25 max), the temperature sensitivity of ecosystem respiration (Q10), and the soil carbon pool size. The optimization is performed at the global scale at 1° resolution for the period from 2002 to 2008. The results indicate that vegetation from tropical zones has lower V25 max values than vegetation in temperate regions. Relatively high values of Q10 are derived over high/midlatitude regions. Both V25 max and Q10 exhibit pronounced seasonal variations at middle-high latitudes. The maxima in V25 max occur during growing seasons, while the minima appear during nongrowing seasons. Q10 values decrease with increasing temperature. The seasonal variabilities of V25 max and Q10 are larger at higher latitudes. Optimized V25 max and Q10 show little seasonal variabilities at tropical regions. The seasonal variabilities of V25 max are consistent with the variabilities of LAI for evergreen conifers and broadleaf evergreen forests. Variations in leaf nitrogen and leaf chlorophyll contents may partly explain the variations in V25 max. The spatial distribution of the total soil carbon pool size after optimization is compared favorably with the gridded Global Soil Data Set for Earth System. The results also suggest that atmospheric CO2 data are a source of information that can be tapped to gain spatially and temporally meaningful information for key ecosystem parameters that are representative at the regional and global scales.National Key R&D Program of China Grant Number: 2016YFA0600204; National Natural Science Foundation of China Grant Number: 415713382018-06-2

Surface Plasmon Enhancement on Infrared Photodetection

AbstractInAsSb based infrared photodetector is an alternative to the existing HgCdTe, PbSnTe, and InSb counterparts, but its room temperature performance is still relatively poor. One of the ways to improve its performance is through surface plasmon, which provides near field confinement that leads to enhancement in light matter interaction. In this work, the role of each parameter of two dimensional metallic hole arrays in plasmonic enhancement is studied in details, such as the periodicity of hole array, hole diameter and metal film thickness. The plasmonic resonances and their corresponding electric field distributions are comprehensively studied in finite difference time domain simulation, which also would serve as a guide for designing surface plasmon enhanced InAsSb infrared detector with high quantum efficiency and signal-to-noise ratio