Search

Objective To investigate the effect of wide surgical margin on the prognosis of patients with single intrahepatic cholangiocarcinoma (ICC) undergoing hepatectomy and the effect of microvascular invasion (MVI) on the treatment of hepatectomy with both wide surgical margin and narrow surgical margin. Methods From December 2011 to December 2017, the clinicopathological data of 302 patients with single ICC who underwent radical resection were retrospectively studied in 13 medical centers. According to the width of surgical margin, there were 126 patients (41.7%) in wide surgical margin group (≥1 cm) and 176 patients (58.3%) in narrow surgical margin group (0.05). Disease-free survival rate in wide surgical margin group before PSM was significantly higher than that in narrow surgical margin group (P=0.005), while overall survival rate showed no statistically significant difference (P=0.053). After PSM, both overall survival rate and disease-free survival rate in wide surgical margin group were significantly higher than those in narrow surgical margin group (P0.05). In MVI negative group, however both overall survival rate and disease-free survival rate were significantly higher in the patients with wide surgical margin hepatectomy than in those with narrow surgical margin (P

We present an analysis of version 5.1 of the Community Atmospheric Model (CAM5.1) at a high horizontal resolution. Intercomparison of this global model at approximately 0.25°, 1°, and 2° is presented for extreme daily precipitation as well as for a suite of seasonal mean fields. In general, extreme precipitation amounts are larger in high resolution than in lower-resolution configurations. In many but not all locations and/or seasons, extreme daily precipitation rates in the high-resolution configuration are higher and more realistic. The high-resolution configuration produces tropical cyclones up to category 5 on the Saffir-Simpson scale and a comparison to observations reveals both realistic and unrealistic model behavior. In the absence of extensive model tuning at high resolution, simulation of many of the mean fields analyzed in this study is degraded compared to the tuned lower-resolution public released version of the model.

Summary: Legume nodulation requires the detection of flavonoids in the rhizosphere by rhizobia to activate their production of Nod factor countersignals. Here we investigated the flavonoids involved in nodulation of Medicago truncatula.We biochemically characterized five flavonoid‐O‐methyltransferases (OMTs) and a lux‐based nod gene reporter was used to investigate the response of Sinorhizobium medicae NodD1 to various flavonoids.We found that chalcone‐OMT 1 (ChOMT1) and ChOMT3, but not OMT2, 4, and 5, were able to produce 4,4′‐dihydroxy‐2′‐methoxychalcone (DHMC). The bioreporter responded most strongly to DHMC, while isoflavones important for nodulation of soybean (Glycine max) showed no activity. Mutant analysis revealed that loss of ChOMT1 strongly reduced DHMC levels. Furthermore, chomt1 and omt2 showed strongly reduced bioreporter luminescence in their rhizospheres. In addition, loss of both ChOMT1 and ChOMT3 reduced nodulation, and this phenotype was strengthened by the further loss of OMT2.We conclude that: the loss of ChOMT1 greatly reduces root DHMC levels; ChOMT1 or OMT2 are important for nod gene activation in the rhizosphere; and ChOMT1/3 and OMT2 promote nodulation. Our findings suggest a degree of exclusivity in the flavonoids used for nodulation in M. truncatula compared to soybean, supporting a role for flavonoids in rhizobial host range. [ABSTRACT FROM AUTHOR]

Here, Ca5Mn4−xNixV6O24 (CMNVO, x = 0.00–0.08) ceramics are successfully prepared by the solid-phase reaction method, and the connection between the physical phase information, microscopic morphology, Raman spectroscopy, and microwave dielectric properties is explored. The experimental results show that Ni2+ occupies the Mn2+ sites without altering the crystal structure and is effectively solid-solvated into the lattice. The relative density reaches a maximum value of 95.9% when the temperature (Tem.) = 900°C and x = 0.06. The trend of the dielectric constant (εr) depends on the ionic polarization rate, and the quality factor (Q×f values) are correlated with the microstructure and relative density. The maximum value of 43,800 GHz is reached at Tem. = 900°C and x = 0.06, and the temperature coefficient of resonant frequency (τf values) is enhanced from −75 ppm/°C to −52 ppm/°C. The CMNVO (x = 0.06) ceramic obtains better microwave dielectric properties (εr = 11.4, Q×f = 43,800 GHz, and τf = −52 ppm/°C). This ceramic material is expected to be a candidate for low-temperature co-fired ceramic (LTCC) microwave devices. [ABSTRACT FROM AUTHOR]

High-resolution climate models have been shown to improve the statistics of tropical storms (TCs) and hurricanes compared to low-resolution models. The impact of increasing horizontal resolution in the TC simulation is investigated exclusively using a series of Atmospheric Global Climate Model (AGCM) runs with idealized aquaplanet steady-state boundary conditions and a fixed operational storm-tracking algorithm. The results show that increasing horizontal resolution helps to detect more hurricanes, simulate stronger extreme rainfall, and emulate better storm structures in the models. However, increasing model resolution does not necessarily produce stronger hurricanes in terms of maximum wind speed, minimum sea-level pressure, and mean precipitation, as the increased number of storms simulated by high-resolution models is mainly associated with weaker storms. The spatial scale at which the analyses are conducted appears to have more important control on these meteorological statistics compared to horizontal resolution of the model grid. When the simulations are analyzed on common low-resolution grids, the statistics of the hurricanes, particularly the hurricane counts, show reduced sensitivity to the horizontal grid resolution and signs of scale invariance. ©2013. American Geophysical Union. All Rights Reserved.

Extreme precipitation is generally underestimated by current climate models relative to observations of present-day rainfall distributions. Possible causes of this systematic error include the convective parameterization in these models that have been designed to reproduce measurements of climatological mean precipitation. One possible approach to improve the interaction of subgrid-scale physical processes and large-scale climate is to replace the conventional convective parameterizations with a high-resolution cloud-system resolving model. A "super-parameterized" Community Atmosphere Model (SP-CAM) utilizing this approach is used in this study to investigate the distribution of extreme precipitation in the United States. Results show that SP-CAM better simulates the distributions of both light and intense precipitation compared to the standard version of CAM based upon conventional parameterizations. The improvements are mostly seen in regions dominated by convective precipitation, suggesting that super-parameterization provides a better representation of subgrid convective processes. Copyright © 2012 by the American Geophysical Union.

Current climate models produce quite heterogeneous projections for the responses of precipitation extremes to future climate change. To help understand the range of projections from multimodel ensembles, a series of idealized 'aquaplanet' Atmospheric General Circulation Model (AGCM) runs have been performed with the Community Atmosphere Model CAM3. These runs have been analysed to identify the effects of horizontal resolution on precipitation extreme projections under two simple global warming scenarios. We adopt the aquaplanet framework for our simulations to remove any sensitivity to the spatial resolution of external inputs and to focus on the roles of model physics and dynamics. Results show that a uniform increase of sea surface temperature (SST) and an increase of low-to-high latitude SST gradient both lead to increase of precipitation and precipitation extremes for most latitudes. The perturbed SSTs generally have stronger impacts on precipitation extremes than on mean precipitation. Horizontal model resolution strongly affects the global warming signals in the extreme precipitation in tropical and subtropical regions but not in high latitude regions. This study illustrates that the effects of horizontal resolution have to be taken into account to develop more robust projections of precipitation extremes. © 2011 The Authors Tellus A © 2011 John Wiley & Sons A/S.

One key question regarding current climate models is whether the projection of climate extremes converges to a realistic representation as the spatial and temporal resolutions of the model are increased. Ideally the model extreme statistics should approach a fixed distribution once the resolutions are commensurate with the characteristic length and time scales of the processes governing the formation of the extreme phenomena of interest. In this study, a series of AGCM runs with idealized 'aquaplanet-steady-state' boundary conditions have been performed with the Community Atmosphere Model CAM3 to investigate the effect of horizontal resolution on climate extreme simulations. The use of the aquaplanet framework highlights the roles of model physics and dynamics and removes any apparent convergence in extreme statistics due to better resolution of surface boundary conditions and other external inputs. Assessed at a same large spatial scale, the results show that the horizontal resolution and time step have strong effects on the simulations of precipitation extremes. The horizontal resolution has a much stronger impact on precipitation extremes than on mean precipitation. Updrafts are strongly correlated with extreme precipitation at tropics at all the resolutions, while positive low-tropospheric temperature anomalies are associated with extreme precipitation at mid-latitudes. © 2011 The Authors Tellus A © 2011 John Wiley & Sons A/S.