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Background Sarcopenia, defined as a loss of skeletal muscle mass and quality, is found in 30–65% of patients with pancreatic ductal adenocarcinoma (PDAC) at diagnosis, and is a poor prognostic factor. However, it is yet to be evaluated why sarcopenia is associated with poor prognosis. Therefore, this study elucidated the tumor characteristics of PDAC with sarcopenia, including driver gene alterations and tumor microenvironment. Patients and Methods We retrospectively analyzed 162 patients with PDAC who underwent pancreatic surgery between 2008 and 2017. We defined sarcopenia by measuring the skeletal muscle mass at the L3 level using preoperative computed tomography images and evaluated driver gene alteration (KRAS, TP53, CDKN2A/p16, and SMAD4) and tumor immune (CD4+, CD8+, and FOXP3+) and fibrosis status (stromal collagen). Results In localized-stage PDAC (stage ≤ IIa), overall survival (OS) and recurrence-free survival were significantly shorter in the sarcopenia group than in the non-sarcopenia group (2-year OS 89.7% versus 59.1%, P = 0.03; 2-year RFS 74.9% versus 50.0%, P = 0.02). Multivariate analysis revealed that sarcopenia was an independent poor prognostic factor in localized-stage PDAC. Additionally, tumor-infiltrating CD8+ T cells in the sarcopenia group were significantly less than in the non-sarcopenia group (P = 0.02). However, no difference was observed in driver gene alteration and fib.rotic status. These findings were not observed in advanced-stage PDAC (stage ≥ IIb). Conclusions Sarcopenia was associated with a worse prognosis and decreased tumor-infiltrating CD8+ T cells in localized-stage PDAC. Sarcopenia may worsen a patient’s prognosis by suppressing local tumor immunity.

Curative treatment for hepatocellular carcinoma (HCC) is limited to hepatic resection (HR), radiofrequency ablation, and liver transplantation, while the value of particle therapy (PT) as an initial treatment remains unclear. This study aimed to compare the outcomes of HR and PT for single HCC.A total of 554 patients with single HCC without vascular invasion were enrolled from January 2000 to December 2015. Patients underwent either HR (n = 279) or PT (n = 275) as initial treatments. A one-to-one propensity score matching (PSM) analysis was performed to evaluate the overall survival (OS) and progression-free survival (PFS) after dividing patients according to liver function as assessed by the modified albumin-bilirubin (mALBI) grade.The median OS (130 vs. 85 month, p = 0.001) and PFS (47 vs. 30 month, p = 0.004) of HR were also significantly better than that of PT in the PSM cohort with mALBI grade 1/2a (n = 145 per group). Meanwhile, in a PSM cohort with mALBI grade 2b/3 (n = 53 per group), there were no significant differences in median OS and PFS between HR and PT.HR may be preferable as an initial treatment for patients with single HCC without vascular invasion, especially those with preserved liver function. PT can be an acceptable alternative to HR for patients without surgical indication and/or impaired liver function.

Key Points: • First ever measurements with a high‐accuracy single‐particle soot photometer of black carbon (BC) concentrations in Arctic snowpack • Topography and BC emission flux strongly influenced latitudinal variations of mass concentrations and size distributions of BC • Measured BC mass concentrations 2–25 times lower than previously reported show the importance of revalidating climate models Black carbon (BC) deposited on snow lowers its albedo, potentially contributing to warming in the Arctic. Atmospheric distributions of BC and inorganic aerosols, which contribute directly and indirectly to radiative forcing, are also greatly influenced by depositions. To quantify these effects, accurate measurement of the spatial distributions of BC and ionic species representative of inorganic aerosols (ionic species hereafter) in snowpack in various regions of the Arctic is needed, but few such measurements are available. We measured mass concentrations of size-resolved BC (CMBC) and ionic species in snowpack by using a single-particle soot photometer and ion chromatography, respectively, over Finland, Alaska, Siberia, Greenland, and Spitsbergen during early spring in 2012–2016. Total BC mass deposited per unit area (DEPMBC) during snow accumulation periods was derived from CMBC and snow water equivalent (SWE). Our analyses showed that the spatial distributions of anthropogenic BC emission flux, total precipitable water, and topography strongly influenced latitudinal variations of CMBC, BC size distributions, SWE, and DEPMBC. The average size distributions of BC in Arctic snowpack shifted to smaller sizes with decreasing CMBC due to an increase in the removal efficiency of larger BC particles during transport from major sources. Our measurements of CMBC were lower by a factor of ~13 than previous measurements made with an Integrating Sphere/Integrating Sandwich spectrophotometer due mainly to interference from coexisting non-BC particles such as mineral dust. The SP2 data presented here will be useful for constraining climate models that estimate the effects of BC on the Arctic climate. Plain Language Summary Black carbon (BC) particles, commonly known as soot, are emitted from incomplete combustion of fossil fuels and biomass. They efficiently absorb solar radiation and thus heat the atmosphere. BC particles emitted at midlatitudes and in the Arctic are deposited onto snow in the Arctic, accelerating snowmelt in early spring by absorbing solar radiation. These processes contribute to warming in the Arctic. Calculations of this warming effect by using numerical models need to be validated by comparison with observed BC concentrations in snowpack. However, there are very few accurate records of concentrations of BC in snow because of technical difficulties in making these measurements. We developed a new laser-induced incandescence technique to measure BC concentrations in snowpack and applied it for the first time in six Arctic regions (Finland, Alaska, North and South Siberia, Greenland, and Spitsbergen). The BC concentrations we measured were highest in Finland and South Siberia, which are closer to large anthropogenic BC sources than the other regions, where our measured BC concentrations were much lower. On average, our BC concentrations were much lower than those previously measured by different techniques. Therefore, previous comparisons of modeled and observed BC concentrations need to be re-evaluated using the present data.

Beta-catenin-activated hepatocellular adenoma is potentially malignant and warrants careful follow-up and surgical resection. Here, we report a 48-year-old man in whom a 55 mm single liver tumor was incidentally detected in the S1 segment. Contrast-enhanced computed tomography scans showed no enhancement in the early phase and a slight defection in the late phase. The tumor was enhanced hyperintensity in the hepatobiliary phase on Gd-ethoxybenzyl-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging. The histologic features of ultrasound-guided fine-needle aspiration biopsy indicated hepatocellular adenoma, and the tumor was immunohistochemically positive for glutamine synthetase and β-catenin. Considering the risk of malignant transformation, he underwent laparoscopic-assisted partial liver resection. The resected tumor did not contain any malignant lesions. This case indicates that aspiration needle biopsy and immunohistochemistry were useful for histological diagnosis and treatment decisions based on the molecular definition of hepatocellular adenoma.

There is an atmospheric electric field (AEF) or an electric potential gradient (PG) in fair weather between the Earth's surface and the mesosphere/ionosphere, which is positive. During blizzards/snowstorms in the polar regions, an intense positive AEF/PG in the order of 103 V/m of the same polarity in fair weather was observed using an electric field mill at 1.4 m in height. In contrast, a moderately negative AEF/PG variation after a blizzard was observed in 2015 at Syowa Station, Antarctica. The negative variation, where the magnitude ranged from tens to hundreds of V/m, gradually recovered into the positive AEF/PG for more than 40 min. According to various studies on blowing/drifting snow dynamics and electricity in laboratory experiments and field observations, snow particles colliding with the snow surface are charged, and the charge of suspended and saltating particles during the snowstorm is negative on average. To verify the AEF/PG observed during and after the blizzards, we numerically estimated the electric field surrounding the conductive sensor unit of the electric field mill using a three-dimensional Poisson equation. Under blizzard conditions, the polarity of the estimated AEF/PG was the opposite of that of the observed AEF/PG. From the noise study of the field mill, we deduced that the positive AEF/PG variations were caused by the collision of negatively charged snow particles with the electric probe on the sensor unit. Just after the blizzard, the number of snow particles measured at 4.4 m in height clearly decreased, and the camera image showed clear visibility. From this evidence, we modeled the suspended and saltating negatively charged snow particles that had fallen onto the ground surface and then constructed a charge layer of the snow particles softly attaching to the ground, which slowly discharged following the study on the electrical resistance of the powders. The three-dimensional Poisson calculation based on the model reproduced a moderately negative AEF/PG. Thus, we elucidated that the origins of the intense positive and moderate negative electric fields during and after blizzards are the charged snow particles colliding with the electric probe on the sensor unit and the negative snow layers softly attached to the ground, respectively. These results are applicable to studies on dust storm electrification on Mars' and Earth's deserts, snowstorm electrification in the polar regions, and high mountains, such as Mt. Fuji in Japan, and turbulent electrification for industrial dust, which provides the identification of intense electrification and storms.

The Ninth Symposium on Polar Science/Interdisciplinary sessions: [IW] Whole atmosphere, Thu. 6 Dec. / 3F Seminar room D304, Institute of Statistics and Mathematics

AbstarctThere are some reports on the measurement of the charge-to-mass ratio of blowing-snow particles, but there are few studies concerned with individual snow-particle charge. We measured the charge-to-mass ratios using snow particles selected according to size, and discussed individual charges. Experiments were conducted in a cryogenic wind tunnel. Charge-to-mass ratios measured in our experiment were all negative and their absolute values tended to increase with a decrease in particle diameter. Individual snow-particle charges were calculated from the average of particle diameter distributions. The charges were all approximated by the power function of diameter at each temperature. Assuming that the coefficient of these approximations is a function of air temperature, we could easily predict the individual snow-particle charge.