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[Objective] The summer rainfall intensity in the desert steppe is strong and concentrated, and the harm of hydraulic erosion is serious. It is of great significance for soil and water conservation in this area to clarify the process of runoff and sediment yield, as well as the law of nutrient transport. [Methods] The experiment is based on natural rainfall observation data and artificial rainfall simulation methods, studying the runoff and sediment production processes, nutrient transport patterns in the desert steppe area, and investigating the impact of vegetation on runoff and sediment production through different vegetation treatments. [Results] (1) Different vegetation treatments had different effects on soil and water conservation. Among the three different treatments, the soil and water conservation effect of natural grassland the best, and the runoff reduction rate and sediment reduction rate were 11.37% and 49.67%, respectively. (2) The process of runoff and sediment production would change the material composition of surface soil, make the surface soil coarse-grained, and also affect soil nutrients. After rainfall, the sand content increased by 5.97%~15.71%, and the soil available N, P and organic matter decreased by 40.84%, 27.08%, 33.49%, respectively. (3) The runoff and sediment yield increased with the increase of slope and rainfall intensity, and the power function can better fit the relationship between rainfall duration and runoff and sediment yield. With the increase of rainfall intensity, the peak runoff yield increased by 6.70 L on average when the slope was 5°~25°. When the rainfall intensity is 0.6~2.0 mm/L, the inflection point of the sediment yield increase rate will appear between the slope of 15°~20°. [Conclusion] The research results can provide a theoretical reference for the comprehensive prevention and control of soil and water loss in desert steppe areas, which is helpful in improving the ecological environment of desert steppe regions and carrying out soil and water conservation efforts in this area.

Objective To investigate the clinicopathologic features and differential diagnosis of primary lung adenocarcinoma with enteroblastic differentiation ( LAED ). Methods The clinical and imaging data, pathological morphology, immunophenotypic characteristics, and genetic testing results of two patients with LAED collected from 2018 to 2022 were retrospectively analyzed, and relevant literature was reviewed. Results Both patients were middle-aged males and long-term smokers. Their serum alpha-fetoprotein (AFP) levels were >20 000 ng/mL and 914.17 ng/mL, respectively. The lesions were located in the right upper lobe and left lower lobe, with a maximum diameter of 12.5 cm and 4.0 cm, respectively. The surgical resection specimens of the patients showed that the tumor sections were grayish white and grayish red, solid, soft, and locally friable. Microscopically, most of the tumor tissues were solid, and a small part was glandular, papillary, or cystic glandular. The cytoplasm of the tumor cells was clear and rich in glycogen. Immunohistochemical tests showed that the tumor tissues had both embryonic differentiation and intestinal differentiation phenotypes, and did not express hepatocyte differentiation markers. Molecular tests showed no mutations in EGFR, ALK/ROS1, RET, KRAS, BRAF, NTRK, and MET, no amplification of HER-2, and EBER was negative. Both patients were diagnosed with LAED. Because of the overlap in morphology and immunophenotype with hepatoid adenocarcinoma and other poorly differentiated adenocarcinomas with clear cytoplasm, and the elevated AFP levels in both cases, LAED was easy to be misdiagnosed. One patient gave up treatment and died 2 months later. The other patient received radical lobectomy and adjuvant chemotherapy, immune and targeted therapy after surgery. After treatment, the AFP level dropped to normal, and the patient died of bone and brain metastasis at 40 months of follow-up. Conclusions LAED is a rare tumor that has not been extensively reported either domestically or internationally. The diagnosis and differential diagnosis of LAED mainly rely on characteristic histology and cell morphology in combination with immunohistochemistry and serum AFP levels. This report broadens the disease spectrum of primary lung adenocarcinoma producing AFP. In general, LAED has a rapid clinical progression and a poor prognosis.

ObjectiveTo investigate the relationship between plasma surfactant protein⁃A （SP⁃A） expression level and silicosis progression， and to provide early evidence for exploring whether SP⁃A can be used as a biomarker for clinical monitoring of silicosis disease progression.MethodsWe recruited 187 silicosis patients in Guangdong Province hospital for occupational disease prevention and treatment between November， 2019 and November，2020. Their peripheral venous blood samples were collected for the plasma isolation. The level of pulmonary SP⁃A was detected by enzyme-linked immunosorbent assay.ResultsThere was a statistically significant difference in the level of SP⁃A among the silicosis groups （P

Objective To evaluate the effects of three different serum-free culture systems on the biological function of human umbilical cord mesenchymal stem cells （hUC-MSC） cultured in vitro. Methods Three strains of umbilical cord tissues were obtained，divided into 3 experimental groups and cultured to the 3rd generation （P3） in three different serum-free culture systems （Group A： serum-free culture system synthesized by pure chemical components，group B： serum-free culture system consisting of platelet lysate+basic culture medium，group C： serum-free culture system consisting of fibrinogen coating+recombinant human protein）. The cell proliferation，cell phenotype，three-line differentiation and immunomodulatory function were compared. Results All the cells in three groups were long and flat fusiform，adherent to the wall and uniform in size. The proliferation curve trend was similar，and the proliferation ability of P2 and P3 generations in groups A and B was better than that in group C （both P + CD25+ FOXP3+） was significantly increased in the three experimental groups，but there was no statistical significance among three experimental groups （all P > 0.05）.Conclusions The hUC-MSC in three groups can maintain basic biological characteristics and immunomodulatory activity. The proliferation ability and expression levels of cell surface markers in groups A and B are superior to those in group C.

In order to achieve high-valued utilization of algal residue, the present study investigated the preparation and activity of antioxidant peptides from Haematococcus pluvialis. Antioxidant peptides were prepared through 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity-guided fractionation of an enzymatic protein hydrolysate from H. pluvialis by using ultrafiltration, preparative high performance liquid chromatography (HPLC) and analytical HPLC. Amino acid sequence was identified by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The antioxidant peptides were screened and confirmed by molecular docking, and the mechanism of action of the antioxidant peptides was clarified. Furthermore, the in vivo antioxidant activity of the antioxidant peptides was evaluated by using Caenorhabditis elegans. The results showed that the antioxidant capacity of the protein hydrolysate from H. pluvialis was enhanced by 2.96-fold after purification, and fraction i, with the strongest free radical scavenging ability (which scavenged (96.97 ± 2.00)% of ABTS radical cation at 0.25 mg/mL) was selected for structural identification. Ten peptide sequences i-1 to i-10 were obtained. The molecular docking results showed that the minimum binding free energy between i-1 and ABTS radical cation was lowest, indicating that i-1 had the strongest antioxidant capacity. Furthermore, the novel antioxidant peptide was identified as KFTPAP. In vivo experiments showed that the peptide significantly improved antioxidant capacity in C. elegans (P < 0.05) in terms of the activities of superoxide dismutase (SOD) and catalase (CAT) and malondialdehyde (MDA) content, the effect being most pronounced at a concentration of 100 μmol/L. The potent antioxidant activity of this peptide may be due to the fact that hydrophobic amino acid residues concentrate at the C-terminus, and it contains phenylalanine residues and derives from chlorophyll proteins. This study provides a reference for the high value-added utilization of H. pluvialis residues and the development of food-derived antioxidants.