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Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease that affects the large intestine and exhibits a relapsing and remitting course. It is a complex immune-mediated disease of the gastrointestinal tract that increases morbidity and negatively influences the quality of life. Although our previous studies have indicated that CD30L is involved in the adaptive immune response in UC, it remains unclear whether it participates in the innate immune response. Our results revealed that the CD30L level significantly increased in the circulating classical monocytes of patients with UC and showed a positive correlation with the severity of UC. CD30L may participate in monocyte-mediated inflammation in patients with UC through the activation of circulating classical monocytes. The present study provides insights into a marker of severity and a potential target for the development of immunological therapy of UC.

With global warming, the soil freeze-thaw state has greatly changed, which has profoundly impacted the balance between water resources, ecological security and regional agriculture and forestry production in frozen regions. Based on daily soil freezing/thawing depth data in Heilongjiang Province over the last 60 years, Mann-Kendall trend analysis, Sen's slope and Hurst exponent were performed to analyze the spatiotemporal characteristics of the soil freeze-thaw state, and the effects of nonclimatic factors "land use types" and snow cover on the change in the soil freeze-thaw state were discussed. The results indicated that (1) the soil freeze-thaw state significantly changed over the past 60 years. The maximum seasonally frozen depth decreased approximately by 48 cm, the first freezing date was delayed by approximately 10 d, the first thawing date and last date advanced approximately by 6 and 27 d, respectively, the freezing and thawing periods decreased by approximately 17 and 21 d, respectively, and the duration and actual number of freezing days decreased by 38 and 34 d, respectively. (2) The soil freeze-thaw state changed abruptly in 1988 and exhibited a significant trend after the 1990s. The Hurst exponent of the soil freeze-thaw state variables at approximately 2/3 of the stations reached the strong persistence level. (3) In forestland and grassland areas, vegetation coverage reduced the climate warming impact on the soil freeze-thaw state. In addition, the maximum snow depth was significantly correlated with the soil freezing depth and first thawing date, and the change in snow depth also offset the effects of temperature rise on soil freezing depth and first thawing date to a certain extent. Changes in the soil freeze-thaw state have both advantages and disadvantages on agricultural production. Therefore, it is necessary to strengthen agricultural monitoring and use territorial knowledge to reasonably regulate agricultural production.

Freezing-thawing deformation is a common phenomenon in seasonal frozen soil areas. Based on indoor simulation experiments, the effects of biochar application amounts (0%, 1%, 2%, and 3%) on freezing-thawing deformation characteristics and the response relationships with soil properties were studied. The results showed that (1) the essence of freezing-thawing deformation is the transformation of soil pore sizes from small to large. The biochar application reduced the transformation range and rate, significantly increased the soil total porosity, promoted thaw settlement and restrained frost heaving. In addition, with increasing numbers of freeze–thaw cycles, the soil total porosity increased with low application amounts (0% and 1%) but decreased with high application amounts (2% and 3%). (2) Freeze-thaw cycling reduced the soil aggregate stability, and the application of an appropriate amount of biochar alleviated the decreasing trend, increased the stability of aggregates, reduced the proportion of silt and clay (

In seasonal frozen soil areas, much meltwater is formed during the thawing period, which easily causes snowmelt floods and waterlogging disasters. The meltwater simultaneously replenishes groundwater and produces surface runoff to provide water for crop roots. However, there are insufficient researches on the infiltration process of meltwater under day thaw and night freezing conditions. Meltwater infiltration process and estimation could provide an important reference for spring irrigation, meltwater disaster early warning systems and soil pollution research. In this study, the law of mass conservation was adopted for meltwater infiltration estimation under 15 and 30 cm snow covers. According to the hypothetical curve trend characteristics of meltwater infiltration rate, it is proposed to adopt Boltzmann distribution function and determine the curve parameters through experimental results, and the average daily maximum infiltration rate of frozen soil is 0.0622 cm/hour. During the thawing period, the soil moisture content changes periodically, and the period lasts approximately 10 h. We also put forward the concept of the maximum meltwater storage volume (Ϝ) of farmland meltwater, which provides a new analysis structure for meltwater runoff research. During the thawing periods, when the snow cover thickness in the early stage of thawing period exceeds Z, the amount of meltwater infiltration does not greatly change, and the maximum infiltration volume is between 3.15 and 5.25 cm. The average daily meltwater infiltration amounts to 0.15 cm.