Seasonal evolution of the subglacial drainage system in the lower ablation area of the Hailuogou glacier ice tongue were revealed by repeated dye tracer (Rhodamine WT) experiments during the 2009 ablation season. Between April and October, 18 dye tracer experiments were conducted by injecting the tracer at one location of the lower ablation area of the Hailuogou Glacier to diagnose the seasonal variation of the subglacial drainage system of this section of glacier ice tongue. Using a simple advection-dispersion model (ADM), the flow velocity, hydrodynamic dispersion coefficient, and degree of tracer spreading were deduced. Tracer transit velocity through the tested subglacial channel varied from 0.148 to 0.555 m s −1 during the 2009 ablation season. Dispersivity showed a relatively high value than that found at other glaciers, which varied between 27.05 and 287.49 m 2 s −1 . Seasonal changes of these indexes indicated that the subglacial drainage system of the lower ablation area of the Hailougou Glacier is a relatively stable existing system in the case of its longitudinal shape, whereas its hydraulic efficiency is low in the early and late ablation seasons and high during the middle of summer due to subglacial channel expansion.

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Background: Pulmonary surfactant dysfunction is an important pathological factor in acute respiratory distress syndrome (ARDS) and pulmonary fibrosis (PF). Objective: In this study, the characteristics of recombinant mature surfactant protein B (SP-B) and reteplase (rPA) fusion protein maintaining good pulmonary surface activity and rPA fibrinolytic activity in acute lung injury cell model were studied. Methods: We studied the characteristics of SP-B fusion expression, cloned rPA gene and N-terminal rPA/C-terminal SP-B co-expression gene, and constructed them into eukaryotic expression vector pEZ-M03 to obtain recombinant plasmids pEZ-rPA and pEZ-rPA/SP-B. The recombinant plasmids was transfected into Chinese hamster ovary (CHO) K1 cells and the expression products were analyzed by Western Blot. Lipopolysaccharide (LPS) was used to induce CCL149 (an alveolar epithelial cell line) cell injury model. Fluorescence staining of rPA and rPA/SP-B was carried out with the enhanced green fluorescent protein (eGFP) that comes with pEZ-M03; the cell Raman spectroscopy technique was used to analyze the interaction between rPA/SP-B fusion protein and the phospholipid structure of cell membrane in CCL149 cells. The enzyme activity of rPA in the fusion protein was determined by fibrin-agarose plate method. Results: The rPA/SP-B fusion protein was successfully expressed. In the CCL149 cell model of acute lung injury (ALI), the green fluorescence of rPA/SP-B is mainly distributed on the CCL149 cell membrane. The rPA/SP-B fusion protein can reduce the disorder of phospholipid molecules and reduce cell membrane damage. The enzyme activity of rPA/SP-B fusion protein was 3.42, and the fusion protein still had good enzyme activity. Conclusion: The recombinant eukaryotic plasmid pEZ-rPA/SP-B is constructed and can be expressed in the eukaryotic system. Studies have shown that rPA/SP-B fusion protein maintains good SP-B lung surface activity and rPA enzyme activity in acute lung injury cell model.