Background
Liver resection is effective for hepatocellular carcinoma (HCC) exceeding the Milan criteria in selected patients. However, the benefit of anatomical resection (AR) versus non‐anatomical ...resection (NAR) has not been clarified in this patient subgroup. This study aimed to compare outcomes between AR and NAR for HCC exceeding the Milan criteria.
Methods
Data on consecutive patients with HCC exceeding the Milan criteria who underwent liver resection with curative intent over a recent 6‐year interval were extracted from a prospective single‐centre HCC database and examined retrospectively. The postoperative outcomes of patients were compared before and after propensity score matching.
Results
Some 546 patients were included: 264 in the AR and 282 in the NAR group. In the original cohort, the AR group contained more patients with larger tumours, multiple tumours, macroscopic portal vein tumour thrombi, incomplete tumour capsules and microscopic vascular invasion. After propensity score matching, 177 pairs of patients were selected. The baseline data, including liver function and tumour burden, were similar in the matched groups. The 3‐year recurrence‐free survival rate was comparable between the matched NAR and AR groups (36·5 versus 28·5 per cent; P = 0·448). Similar results were observed for 3‐year overall survival (57·5 versus 50·3 per cent; P = 0·385), recurrence patterns and early recurrence rates (57·6 per cent versus 59·9 per cent; P = 0·712).
Conclusion
AR and NAR achieved favourable and similar outcomes for HCC exceeding the Milan criteria in selected patients.
No difference
Electromagnetic ion cyclotron (EMIC) waves can drive precipitation of tens of keV protons and relativistic electrons, and are a potential candidate for causing radiation belt flux dropouts. In this ...study, we quantitatively analyze three cases of EMIC‐driven precipitation, which occurred near the dusk sector observed by multiple Low‐Earth‐Orbiting (LEO) Polar Operational Environmental Satellites/Meteorological Operational satellite programme (POES/MetOp) satellites. During EMIC wave activity, the proton precipitation occurred from few tens of keV up to hundreds of keV, while the electron precipitation was mainly at relativistic energies. We compare observations of electron precipitation with calculations using quasi‐linear theory. For all cases, we consider the effects of other magnetospheric waves observed simultaneously with EMIC waves, namely, plasmaspheric hiss and magnetosonic waves, and find that the electron precipitation at MeV energies was predominantly caused by EMIC‐driven pitch angle scattering. Interestingly, each precipitation event observed by a LEO satellite extended over a limited L shell region (ΔL ~ 0.3 on average), suggesting that the pitch angle scattering caused by EMIC waves occurs only when favorable conditions are met, likely in a localized region. Furthermore, we take advantage of the LEO constellation to explore the occurrence of precipitation at different L shells and magnetic local time sectors, simultaneously with EMIC wave observations near the equator (detected by Van Allen Probes) or at the ground (measured by magnetometers). Our analysis shows that although EMIC waves drove precipitation only in a narrow ΔL, electron precipitation was triggered at various locations as identified by POES/MetOp over a rather broad region (up to ~4.4 hr MLT and ~1.4 L shells) with similar patterns between satellites.
Key Points
We show three cases of proton and relativistic electron precipitation observed simultaneously with EMIC waves
EMIC‐driven precipitation was observed by POES/MetOp satellites at different locations over a broad L‐MLT region
Each precipitation event extended over ΔL ~ 0.3 on average, showing that wave‐driven pitch angle scattering is localized
We present a global survey of energetic electron precipitation from the equatorial magnetosphere due to hiss waves in the plasmasphere and plumes. Using Van Allen Probes measurements, we calculate ...the pitch angle diffusion coefficients at the bounce loss cone, and evaluate the energy spectrum of precipitating electron flux. Our ∼6.5‐year survey shows that, during disturbed times, hiss inside the plasmasphere primarily causes the electron precipitation at L > 4 over 8 h < MLT < 18 h, and hiss waves in plumes cause the precipitation at L > 5 over 8 h < MLT < 14 h and L > 4 over 14 h < MLT < 20 h. The precipitating energy flux increases with increasing geomagnetic activity, and is typically higher in the plasmaspheric plume than the plasmasphere. The characteristic energy of precipitation increases from ∼20 keV at L = 6–∼100 keV at L = 3, potentially causing the loss of electrons at several hundred keV.
Plain Language Summary
Hiss is a plasma wave with a broad frequency range spanning from tens to several thousand Hz, commonly observed in the dayside plasmasphere and plumes of the Earth's magnetosphere, and plays an important role in the loss of energetic electrons. Subject to the interaction with hiss waves, the radiation belt electrons precipitate from the equatorial magnetosphere into the Earth's upper atmosphere, potentially changing the ionospheric conductance and chemistry. Using the measurements of hiss waves and electrons from the ∼6.5‐year data of Van Allen Probes, we perform a global survey of electron precipitation due to hiss waves in the magnetosphere. Our survey indicates that hiss waves mostly cause the energetic electron precipitation in the dayside plasmasphere and in the afternoon sector of the plume. The precipitation is more significant during disturbed geomagnetic conditions than quiet times, and the precipitating flux is higher in the plasmaspheric plume than the plasmasphere. The characteristic energy of precipitating electrons increases with decreasing distance from the Earth. Although the average precipitating electron flux due to hiss is lower than that of chorus, the average energy of precipitation is higher, potentially causing the loss of relativistic electrons in the radiation belts.
Key Points
During disturbed times, hiss waves cause enhanced electron precipitation in the dayside plasmasphere and plume in the afternoon sector
The average total precipitating energy flux due to hiss waves reaches 0.3–1 erg/cm2/s at L > 4.5 and 8 h < MLT < 18 h when AE∗ > 500 nT
Average precipitating flux is higher in the plume than plasmasphere, and the precipitation energy increases with decreasing L shell
The magnetic refrigeration technique based on the magnetocaloric effect (MCE) has attracted increasing interest because of its high efficiency and environment friendliness. In this article, our ...recent progress in exploring effective MCE materials is reviewed with emphasis on the MCE in the LaFe13−xSixbased alloys discovered by us. These alloys show large entropy changes over a wide temperature range near room temperature. The effects of magnetic rare‐earth doping, interstitial atoms and high pressure on the MCE have been systematically studied. Special issues, such as appropriate approaches to determining the MCE associated with the first‐order magnetic transition, the depression of magnetic and thermal hysteresis, and the key factors determining the magnetic exchange in alloys of this kind, are discussed. The applicability of giant MCE materials to magnetic refrigeration near ambient temperature is evaluated. A brief review of other materials with significant MCE is also presented.
Recent progress in the study of the magnetic properties and magnetocaloric effects (MCEs) of the LaFe13−xSix‐based compounds, which have large MCEs over a wide temperature range near room temperature, is reviewed. The effects of magnetic rare‐earth doping, interstitial atoms and high pressure on the magnetic exchange, entropy change, and magnetic hysteresis are discussed. The applicability of the giant MCE materials to the magnetic refrigeration near ambient temperature is evaluated.
Whistler mode chorus waves can scatter plasma sheet electrons into the loss cone and produce the Earth's diffuse aurora. Van Allen Probes observed plasma sheet electron injections and intense chorus ...waves on 24 November 2012. We use quasilinear theory to calculate the precipitating electron fluxes, demonstrating that the chorus waves could lead to high differential energy fluxes of precipitating electrons with characteristic energies of 10–30 keV. Using this method, we calculate the precipitating electron flux from 2012 to 2019 when the Van Allen Probes were near the magnetic equator and perform global surveys of electron precipitation under different geomagnetic conditions. The most significant electron precipitation due to chorus is found from the nightside to dawn sectors over 4 < L < 6.5. The average total precipitating energy flux is enhanced during disturbed conditions, with time‐averaged values reaching ~3–10 erg/cm2/s when AE ≥ 500 nT.
Plain Language Summary
Whistler mode chorus is an electromagnetic emission present in the low‐density region of Earth's magnetosphere. Chorus waves can change the electron distribution in the plasma sheet to cause electron precipitation into Earth's upper atmosphere, leading to the diffuse aurora. We use satellite measurements of waves and electrons to quantify the electron precipitation from the plasma sheet to the upper atmosphere. An event study is presented to demonstrate that intense chorus waves observed near the magnetic equator can cause high energy fluxes of precipitating electrons with characteristic energy of 10–30 keV. To obtain the statistics of the electron precipitation, we calculate the precipitating electron flux from 2012 to 2019 using wave and electron measurements near the magnetic equator. Our survey indicates that chorus waves can cause the precipitation from the nightside to dawn sectors, over an equatorial radial distance of 4–6.5 Earth radii. The energy flux of electron precipitation is enhanced during disturbed geomagnetic conditions compared to quiet conditions. Our study provides the quantification of the empirical electron precipitation from the plasma sheet due to chorus on a global scale.
Key Points
We evaluate the electron precipitation due to whistler mode chorus waves and perform a global survey of the precipitating flux at L < 6.5
The chorus waves cause the precipitation of 1‐ to 100‐keV electrons predominantly from the nightside to dawn sectors over 4 < L < 6.5
Average total precipitating energy flux is enhanced during disturbed conditions, reaching 3–10 erg/cm2/s when AE > 500 nT
Interchange instability is known to drive fast radial transport of particles in Jupiter's inner magnetosphere. Magnetic flux tubes associated with the interchange instability often coincide with ...changes in particle distributions and plasma waves, but further investigations are required to understand their detailed characteristics. We analyze representative interchange events observed by Juno, which exhibit intriguing features of particle distributions and plasma waves, including Z‐mode and whistler‐mode waves. These events occurred at an equatorial radial distance of ∼9 Jovian radii on the nightside, with Z‐mode waves observed at mid‐latitude and whistler‐mode waves near the equator. We calculate the linear growth rate of whistler‐mode and Z‐mode waves based on the observed plasma parameters and electron distributions and find that both waves can be locally generated within the interchanged flux tube. Our findings are important for understanding particle transport and generation of plasma waves in the magnetospheres of Jupiter and other planetary systems.
Plain Language Summary
The centrifugal interchange instability, which has been observed in rapidly rotating planets, like Saturn and Jupiter, moves cold plasmas inside of the magnetosphere further away, and transports hotter, less dense plasmas toward the inner magnetosphere. These moving flux tubes have been observed at Jupiter together with plasma waves, but their detailed characteristics are not fully understood. In the present study, we use observations from the Juno spacecraft to report multiple representative interchange events and evaluate the properties of energetic particles and plasma waves. Furthermore, we use linear theory to calculate the growth rates of Z‐mode and whistler‐mode waves during these events. Our findings reveal the typical features of plasma waves and particles during interchange events, which provide important insights into particle transport and generation of plasma waves at Jupiter and possibly other magnetized planets in our solar system and beyond.
Key Points
Several plasma transport events associated with interchange instability are identified alongside plasma waves using Juno observations
Linear growth rate analyses indicate that waves can be locally generated during interchange events due to anisotropic electron distributions
Our findings provide insights into electron transport and plasma wave dynamics during interchange events in planetary magnetospheres
Whistler mode waves are important for precipitating energetic electrons into Earth's upper atmosphere, while the quantitative effect of each type of whistler mode wave on electron precipitation is ...not well understood. In this letter, we evaluate energetic electron precipitation driven by three types of whistler mode waves: plume whistler mode waves, plasmaspheric hiss, and exohiss observed outside the plasmapause. By quantitatively analyzing three conjunction events between Van Allen Probes and POES/MetOp satellites, together with quasi‐linear calculation, we found that plume whistler mode waves are most effective in pitch angle scattering loss, particularly for the electrons from tens to hundreds of keV. Our new finding provides the first direct evidence of effective pitch angle scattering driven by plume whistler mode waves and is critical for understanding energetic electron loss process in the inner magnetosphere. We suggest the effect of plume whistler mode waves be accurately incorporated into future radiation belt modeling.
Plain Language Summary
Electron precipitation into Earth's upper atmosphere is an important loss mechanism of energetic electrons trapped in the inner magnetosphere. Although whistler mode waves are known to be effective in producing electron precipitation through pitch angle scattering, the relative roles of various whistler mode waves that play in electron losses are unclear. In this letter, we quantitatively analyze conjunction events, where Van Allen Probes observed various whistler mode waves near the equator and Low‐Earth‐Orbiting satellites detected electron precipitation approximately along the same magnetic field line but at low altitudes. By combining the satellite data analysis and quasi‐linear theory, we found that whistler mode waves observed in plumes are very effective in scattering energetic electrons, which are ultimately lost through interacting with the neutral atmosphere. Our new finding provides the direct evidence that plume whistler mode waves play an important role in energetic electron precipitation, which is crucial for understanding energetic electron loss process in the Earth's inner magnetosphere.
Key Points
Three types of whistler mode waves are observed during conjunction events between Van Allen Probes and POES/MetOp
These whistler mode waves include plume whistler mode waves, plasmaspheric hiss, and exohiss
Plume whistler mode waves are very effective in producing energetic electron precipitation (from tens to hundreds of keV)
The driver of energetic electron precipitation into Ganymede's atmosphere has been an outstanding open problem. During the Juno flyby of Ganymede on 7 June 2021, Juno observed significant ...downward‐going electron fluxes inside the bounce loss cone of Ganymede's polar magnetosphere. Concurrently, Juno detected intense whistler‐mode waves, both in the quasi‐parallel and highly oblique directions with respect to the magnetic field line. We use quasi‐linear model to quantify energetic electron precipitation driven by quasi‐parallel and very oblique whistler‐mode waves, respectively, in the vicinity of Ganymede. The data‐model comparison indicates that in Ganymede's lower‐latitude (higher‐latitude) polar region, quasi‐parallel whistler‐mode waves play a dominant role in precipitating higher‐energy electrons above ∼100s eV (∼1 keV), whereas highly oblique waves are important for precipitating lower‐energy electrons below 100s eV (∼1 keV). Our result provides new evidence of whistler‐mode waves as a potential primary driver of precipitating energetic electrons into Ganymede's atmosphere.
Plain Language Summary
During the Juno flyby of Ganymede on 7 June 2021, the Juno spacecraft detected energetic electrons precipitating into Ganymede's atmosphere. Simultaneously, Juno detected intense electromagnetic whistler‐mode waves in the vicinity of Ganymede. We use a physics‐based model to quantify the role of the observed whistler‐mode waves in energetic electron precipitation. The comparison between the Juno observation and modeling results reveals that whistler‐mode waves potentially play a dominant role in precipitating energetic electrons into Ganymede's atmosphere over a broad energy range from tens of eV to several hundred keV. Our findings are potentially important for understanding the loss process of energetic electrons in Ganymede's magnetosphere, as well as the generation of Ganymede's diffuse aurora.
Key Points
We provide new evidence of whistler‐mode waves as a potential primary driver of precipitating energetic electrons into Ganymede's atmosphere
This finding is potentially important for the generation of aurora and the loss of energetic electrons in the vicinity of Ganymede
Juno observations and quasi‐linear modeling are used to quantify energetic electron precipitation driven by whistler‐mode waves
High-resolution mapping of fuel combustion and CO2 emission provides valuable information for modeling pollutant transport, developing mitigation policy, and for inverse modeling of CO2 fluxes. ...Previous global emission maps included only few fuel types, and emissions were estimated on a grid by distributing national fuel data on an equal per capita basis, using population density maps. This process distorts the geographical distribution of emissions within countries. In this study, a sub-national disaggregation method (SDM) of fuel data is applied to establish a global 0.1° × 0.1° geo-referenced inventory of fuel combustion (PKU-FUEL) and corresponding CO2 emissions (PKU-CO2) based upon 64 fuel sub-types for the year 2007. Uncertainties of the emission maps are evaluated using a Monte Carlo method. It is estimated that CO2 emission from combustion sources including fossil fuel, biomass, and solid wastes in 2007 was 11.2 Pg C yr−1 (9.1 Pg C yr−1 and 13.3 Pg C yr−1 as 5th and 95th percentiles). Of this, emission from fossil fuel combustion is 7.83 Pg C yr−1, which is very close to the estimate of the International Energy Agency (7.87 Pg C yr−1). By replacing national data disaggregation with sub-national data in this study, the average 95th minus 5th percentile ranges of CO2 emission for all grid points can be reduced from 417 to 68.2 Mg km−2 yr−1. The spread is reduced because the uneven distribution of per capita fuel consumptions within countries is better taken into account by using sub-national fuel consumption data directly. Significant difference in per capita CO2 emissions between urban and rural areas was found in developing countries (2.08 vs. 0.598 Mg C/(cap. × yr)), but not in developed countries (3.55 vs. 3.41 Mg C/(cap. × yr)). This implies that rapid urbanization of developing countries is very likely to drive up their emissions in the future.
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