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Aim: Liver dysfunction is sometimes observed in patients with coronavirus disease 2019 (COVID‐19), but most studies are from China, and the frequency in other countries is unclear. In addition, previous studies suggested several mechanisms of liver damage, but precise or additional mechanisms are not clearly elucidated. Therefore, we examined COVID‐19 patients to explore the proportion of patients with liver dysfunction and also the factors associated with liver dysfunction. Methods: We retrospectively examined 60 COVID‐19 patients hospitalized at the Hospital affiliated with The Institute of Medical Science, The University of Tokyo (Tokyo, Japan). Patients who presented ≥40 U/L alanine aminotransferase (ALT) levels at least once during their hospitalization were defined as high‐ALT patients, and the others as normal‐ALT patients. The worst values of physical and laboratory findings during hospitalization for each patient were extracted for the analyses. Univariable and multivariable logistic regression models with bootstrap (for 1000 times) were carried out. Results: Among 60 patients, there were 31 (52%) high‐ALT patients. The high‐ALT patients were obese, and had significantly higher levels of D‐dimer and fibrin/fibrinogen degradation products, as well as white blood cell count, and levels of C‐reactive protein, ferritin, and fibrinogen. Multivariable analysis showed D‐dimer and white blood cells as independent factors. Conclusions: Considering that higher D‐dimer level and white blood cell count were independently associated with ALT elevation, liver dysfunction in COVID‐19 patients might be induced by microvascular thrombosis in addition to systemic inflammation. [ABSTRACT FROM AUTHOR]

Abstract: Compound-specific carbon isotope ratios (δ13C) of leaf wax n-alkanes (C21–C33 odd carbon numbered n-alkanes) were measured in the Hani peat sequence from northeast China. These data were compared with lipid biomarker compositions to assess changes in local vegetation and paleoclimate for the last 16ka. The δ13C values of n-alkanes range between −36.6 and −30.7‰, showing that the compounds originate from C3 plants. Much larger variations (~5.4‰) in the n-alkane δ13C values than those of atmospheric CO2 during the last 16ka (< 0.5‰) indicate that the isotopic values were affected by environmental factors in addition to the postglacial δ13C variations in the atmospheric reservoir. The stratigraphic records of δ13C reveal decoupled fluctuations among the individual n-alkanes, particularly between 15.5 and 11.4ka. Synchronous excursions in the δ13C offsets among individual n-alkanes (Δδ13C) and lipid biomarker paleoplant proxies (Paq, and C23/C31 and C27/C31) from 14.9 to 13.2ka and 12.7 to 11.6ka suggest that vegetational changes are the most likely causes for the decoupled δ13C variations. Parallel fluctuations of the δ13C values of terrestrial higher plant-derived C29 and C31 n-alkanes and the n-alkane average chain-length (ACL) from 11 to 6ka indicate that the δ13C variations responded to net evaporation changes. Negative shifts in the n-alkane δ13C values coinciding with the ACL decreases at 10.5–9.3ka and 8.1ka indicate the short-term onset and fluctuations of the summer monsoon strength in eastern China during the early Holocene. [ABSTRACT FROM AUTHOR]

The Asian monsoon is a key component of the Earth's climate system that directly affects the livelihood of 60% of the world population. Reliable reconstruction of changes in monsoon precipitation during the Holocene is required to better understand the present climate conditions and to predict future climate processes in the Asian monsoon domain. Reconstruction of changes in Holocene monsoon precipitation has been done in various regions of this domain using a variety of paleoclimate proxies. However, different proxies have yielded different paleoclimate records of long-term monsoon rainfall variability. We apply compound-specific stable hydrogen isotope compositions of the plant wax n-alkanes isolated from the Hongyuan peat sequence in eastern Tibet to reevaluate the regional carbonate oxygen isotopic and lake-level records. The D/H ratios of the n-alkanes resolve the apparent discrepancy among the different paleoclimate proxies. Our result indicates that lake-level fluctuation is a reliable recorder of changes in the amount of summer monsoonal precipitation while long-term isotope records largely reflect large-scale changes in the source of water vapor rather than a local precipitation signal. Combining lake-level, biomarker, and carbonate isotopic records, we conclude that the early Holocene monsoon precipitation in southwest China has been greatly influenced by the Indian monsoon. [ABSTRACT FROM AUTHOR]