Temporal and spatial variation characteristics of surface water area in the Yellow River Basin from 1986 to 2021.

The Yellow River Basin is short of water resources. The dynamic monitoring of surface water area is helpful to clarify the distribution and change trend of water resources in this area. It is of great scientific significance to deeply understand the impacts of climate change and human activities on water resources and ensure the ecological security of the basin. Based on the Google Earth Engine (GEE) cloud platform, we analyzed the spatial variations of surface water area in the Yellow River Basin from 1986 to 2021 by using the mixed index algorithm, and revealed the driving factors of surface water area change in the Yellow River Basin. The results showed that the overall recognition accuracy of the water extraction algorithm based on mixing index was 97.5%. Compared with available water data products, the proposed algorithm can guarantee the integrity of the whole water area to a certain extent. The surface water area in the upper, middle, and lower reaches of the Yellow River Basin was 71.7%, 18.4%, and 9.9% of the total surface water area, respectively. From 1986 to 2021, the surface water area of the basin showed an overall upward trend, with a total increase of 3163.6 km2. The surface water area of the upper, middle, and downstream regions increased by 72.0%, 22.4%, and 5.6%, respectively. The increase of precipitation was the main reason for the increase of water area, with a contribution of 55%. Vegetation restoration and construction of water conservancy projects had increased the water area of the basin. The intensification of human water extraction activity reduced the water area of the basin.

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Understanding the changes of runoff, sediment transport, and hydrodynamic parameters of slopes under the influence of landscape patch coverage and connectivity is of great significance for revealing the hydrodynamic mechanism and hydrological connectivity of slope soil erosion process. In this study, the changes of runoff, sediment transport and hydrodynamic parameters of downhill surface in different coverage levels (0%, 20%, 40%, 60%, 90%) and different connectivity modes (vertical path, horizonal path, S-shaped path, random patches) of shrublands were analyzed by field artificial simulated rainfall test. The results showed that, with the increases of shrub cove-rage, runoff yield and sediment yield decreased exponentially. When the coverage increased to more than 60%, the capacity of shrubs to reduce runoff and sediment became stable. With the increases of shrub coverage, flow velocity, flow depth, Reynolds number, Froude number, stream power, and flow shear resistance significantly decreased, while Manning's roughness coefficient and Darcy-Weisbach resistance coefficient increased significantly. When shrub coverage increased to more than 60%, there was no significant difference in the eigenvalues of hydraulic parameters. The runoff rate under the four connectivity modes followed the order of vertical path > S-shaped path > horizonal path > random patches. The sediment rate was the largest in the vertical path, followed by the S-shaped path, and the horizonal path was not significantly different from the random patches. The path with poor connectivity (horizonal path, random patches) exhibited stronger resistance of hydraulic transmission and poor hydraulic sedimentation capacity than the well-connected path (vertical path, S-shaped path). Our results could provide important theoretical basis for soil erosion control on the Loess Plateau and high-quality development of the Yellow River basin.

Rotundic acid induces Cas3-MCF-7 cell apoptosis through the p53 pathway.

In the present study, the functions and mechanisms of rotundic acid (RA) underlying its induction of apoptosis in caspase-3-transfected MCF-7 human breast cancer cells (Cas3-MCF-7 cells) were investigated. RA induced apoptosis in Cas3-MCF-7 cells more efficiently compared with that in MCF-7 cells transfected with control plasmid. The results from an MTT assay demonstrated that RA effectively inhibited Cas3-MCF-7 cell viability in a dose-dependent manner and induced cell apoptosis via caspase-3 activity within 12 to 48 h. Western blotting and fluorescence-activated cell sorting demonstrated that RA initiated Cas3-MCF-7 cell apoptosis via p53 activation. The silencing of the p53 gene in the Cas3-MCF-7 cell line led to decreased RA-induced Cas3-MCF-7 cell caspase-3 activity and cell apoptosis. Collectively, the results of the present study indicate that caspase-3 serves a critical function in rotundic acid-induced apoptosis, and suggest that caspase-3 deficiency may contribute to the chemotherapy-resistance of breast cancer. Reconstitution of caspase-3 sensitizes MCF-7 breast cancer cells to chemotherapy. RA has the potential for development as a novel drug combined with reconstitution of caspase-3 gene therapy for the treatment of human breast cancer with caspase-3 deficiency.

Rotundic acid enhances the impact of radiological toxicity on MCF-7 cells through the ATM/p53 pathway.

Although radiation therapy is a powerful anticancer modality, radiation- induced stress response and gene expression with adaptive resistance may severely compromise the effectiveness of radiation. The function of rotundic acid (RA) on inducing apoptosis in the human breast cancer cell line MCF-7 has been investigated in a previous study. In the present study, the combined effect of chemotherapy and radiotherapy on reducing side effects was examined. The results of an MTT assay revealed that radiation (0.5, 2 and 10 Gy) effectively inhibit MCF-7 cell viability in a dose-dependent manner, consistent with the effects of RA (2, 5 and 12.5 µM). Interestingly, a lower dose of radiation (1 Gy) combined with RA (5 µM) exhibited a greater inhibition efficiency compared with a high dose of radiation alone. Flow cytometry revealed that radiation combined with RA induced the apoptosis of MCF-7 cells. Using western blotting, it was demonstrated that radiation induced the expression of ataxia-telangiectasia mutated (ATM) and p53 protein, and that RA enhanced this effect. On examining the potential underlying mechanism, it was revealed that radiation and RA combined induce Bcl-2-associated X protein expression and cell apoptosis in MCF-7 cells. An ATM inhibitor was able to restore the effect of radiation and RA on inducing MCF-7 cell apoptosis. These results suggest that the ATM/p53 pathway directly participates in radiation and RA-induced apoptosis in MCF-7 cells. RA has the potential for development as a novel drug for the treatment of human breast cancer combined with radiation therapy, given that the combined side effects are reduced.

Therapeutic effect of chitosan on CCl4­induced hepatic fibrosis in rats.

Chitosan is a linear polysaccharide that is made by treating the chitin shells of shrimp and crustaceans with an alkaline substance, for example sodium hydroxide. Due to its unique physical and chemical properties, chitosan has a wide range of applications in the medical field. Currently, there are no effective treatments for liver fibrosis; therefore, the aim of the present study was to investigate the therapeutic effect of chitosan in a CCl4­induced hepatic fibrosis (HF) rat model. The serum levels of aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) were measured by ELISA. Collagen (COL) 3 and α­smooth muscle actin (SMA) expression levels in the rat liver were detected by reverse transcription­semiquantitative polymerase chain reaction and western blotting, respectively. The results demonstrated that treatment with chitosan significantly improved HF, by decreasing the serum levels of AST, ALT, and ALP; improving liver histology; and decreasing the expression levels of COL3 and α­SMA. Chitosan may offer an alternative approach for the clinical treatment of HF.

Sodium cantharidinate induces HepG2 cell apoptosis through LC3 autophagy pathway.

The function of sodium cantharidinate on inducing hepatocellular carcinoma cell apoptosis was investigated for the first time. Sodium cantharidinate inhibits HepG2 cell growth mainly by LC3 autophagy pathway. MTT results show that sodium cantharidinate effectively inhibits the proliferation of HepG2 cells in a dose- and time-dependent manner and induce cell apoptosis by caspase-3 activity. The further western blotting and FACS detection show that sodium cantharidinate initiates HepG2 cell autophagy program by LC3 pathway. Autophagy-specific inhibitor 3-MA reduce sodium cantharidinate-induced caspase-3 activity and HepG2 cell apoptosis. Silence of the LC3 gene in HepG2 cell lines also reduce sodium cantharidinate-induced cell apoptosis. Collectively, our data indicate that sodium cantharidinate induces HepG2 cell apoptosis through LC3 autophagy pathway. Sodium cantharidinate has potential for development as a new drug for treatment of human HCC.

Role of S100A3 in human hepatocellular carcinoma and the anticancer effect of sodium cantharidinate.

The fifth most common cancer worldwide is hepatocellular carcinoma (HCC), which has an annual mortality rate of ~800,000. Although surgical procedures for HCC, such as hepatic resection and liver transplantation, have progressed and the outcomes of patients have improved, HCC is still characterized by frequent recurrence, even after liver transplantation. In the present study the expression of the protein coding gene, S100 calcium binding protein A3 (S100A3), was observed in 62 HCC tissues and tumor-surrounding tissues. The present study indicated that S100A3 activation was involved in tumorigenesis and tumor aggressiveness. The protein and mRNA expression levels of S100A3 in the human HCC cell line (HepG2) were investigated using western blotting and reverse transcription-quantitative polymerase chain reaction analysis, respectively. The function of sodium cantharidinate in inducing HCC cell apoptosis was also investigated. Sodium cantharidinate inhibited the protein and gene expression of S100A3 in HepG2 cells in vitro. These data suggested that S100A3 has an important role in human HCC. The present study indicates that the functional properties of sodium cantharidinate are promising for the development of a novel drug that may control the expression of S100A3 and improve the treatment of human HCC in the near future.

Design, synthesis and evaluation of antitumor activity of new rotundic acid acylhydrazone derivatives.

In light of the important antitumor activity of acylhydrazone compounds and based on our previous study, 18 new rotundic acid (RA) acylhydrazone derivatives were synthesized. All of the compounds were characterized by their spectroscopic data. The antiproliferative activity of the compounds was evaluated in vitro via the MTT method in three tumor cell lines, including A-375 (human malignant melanoma cells), SPC-A1 (human lung adenocarcinoma) and NCI-H446 (small cell lung cancer). The results showed that the antiproliferative activity of all of the compounds on the NCI-H446 cell line did not increase compared to RA, however, most of the derivatives exhibited higher activity against the A375 and SPC-A1 cell lines as compared to RA. Importantly, the antiproliferative activities of compounds 5a and 5b were the highest among the compounds, with IC(50) values <10 µM. Collectively, compounds 5a and 5b may act as potential anti-tumor agents in the future.

Role of S100A3 in human colorectal cancer and the anticancer effect of cantharidinate.

Colorectal cancer (CRC) is a leading cause of cancer-related mortality. The early diagnosis and treatment of CRC is the key to improving the survival of patients who may benefit from adjuvant chemotherapy. In the present study, the protein expression of S100A3 was observed in a cohort of 20 patients with cancer, which indicated that S100A3 activation was involved in tumorigenesis. In addition, the anticancer activity of cantharidinate was investigated using immunohistochemistry and quantitative polymerase chain reaction (qPCR) analysis. The protein expression of S100A3 was observed to increase by 2.4-fold in human CRC cells compared with the expression level in normal control cells (P<0.01). Cantharidinate inhibited the protein and gene expression of S100A3 in UCT-116 human CRC cells in vitro. These results suggested that S100A3 is important in human CRC. Cantharidinate has the potential to be considered as a novel adjuvant drug for controlling the expression of S100A3 in human CRC as it exhibits preventive effects.

Novel rotundic acid derivatives: synthesis, structural characterization and in vitro antitumor activity.

Six novel rotundic acid (RA, 1) derivatives 4a-4f modified at the 28-COOH position were synthesized, and their structures were confirmed by IR, MS, 1H NMR and 13C NMR. The derivatives were evaluated for cytotoxic properties on the following three tumor cell lines: HeLa, HepG2 and SGC-7901. Compound 4f showed better cytotoxic activity compared with RA treatment and lower IC50 (4.16 µM) on HepG2 cells than on HeLa (8.54 µM) and SGC-7901 cells (11.32 µM). The anticancer mechanism of compound 4f was studied through cell cycle progression and apoptosis. Notably, compound 4f was able to induce apoptosis and G0/G1 cell cycle arrest of HepG2 at a concentration of 4.16 µM. In summary, RA was modified to obtain six novel derivatives. Compound 4f exhibited better cytotoxicity and may be developed as a potential agent against hepatocellular carcinoma.

Mitochondrial DNA evidence of southward migration of Manchus in China.

The Northeast area of China is a cross region between East Asia and Siberia. Although five populations from this area have been studied in maternal lineage, little is known about the genetics of other populations. In this study, forty-seven Manchu individuals were analyzed using a mitochondrial DNA marker, and fourteen mitochondrial DNA haplogroups, the representative haplogroups of east Eurasian, were identified. All analyses showed that Manchu were close to the neighboring populations such as Mongolian, Korean and northern Han Chinese, and were far from the other populations who lived in the cradle of Manchu, suggesting that the Manchu integrated gradually with natives following its southward migration.

[Effects of topographies and land uses on soil organic carbon in subsurface in hilly region of Loess Plateau].

It is important to accurately assess soil carbon sequestration potential and the global carbon cycle to study effects of topographies and land uses on soil profile organic carbon in subsurface. In Yangou watershed of hilly region of Loess Plateau, based on three topographies (tableland, slopeland, gullyland) and seven land uses (farmland, orchard, secondary grassland, manmade and secondary shrubland and manmade and secondary woodland), 53 soil profiles (0-100 cm) in six soil depths up to 898 samples were collected to investigate effects of topographies and land uses on contents and spatial distribution of soil organic carbon in subsurface. Topographies, land uses, depths and interaction of them significantly (p < 0.01) affected spatial distribution of soil organic carbon in subsurface in Yangou watershed. SOC had different spatial distribution in topographies between subsurface (10-100 cm) and surface (0-10 cm). In 0-10 cm soil layer, the content of soil organic carbon of slopeland (10.7 g x kg(-1)) was the highest, followed by gullyland (8.9 g x kg(-1)), the content of SOC of tableland (4.4 g x kg(-1)) was the lowest. But the contents of SOC every layer in 10-100 cm expressed as gullyland > slopeland > tableland trends, the average contents of SOC were 5.6 g x kg(-1), 4.5 g x kg(-1) and 3.2 g x kg(-1). Land uses significantly (p < 0.05) affected spatial distribution of SOC in subsurface in Yangou watershed. Compared with farmland, the content of SOC of orchard in 0-40 cm decreased by 21%, yet increased by 13% in 80-100 cm. The content of SOC of manmade shrubland (2.6 g x kg(-1)) was 19% lower than that of farmland, while SOC content of manmade woodland (3.4 g x kg(-1)) was 6% higher than that of farmland. The content of SOC of secondary shrubland was higher than that of any other land uses in 20-100 cm, but it is significantly (p < 0.05) different form other land uses in 40-100 cm, the average contents was 5.3 g x kg(-1), which was 66% higher than that of farmland. The content of SOC of secondary woodland was higher than that of any other land uses in 0-20 cm, but it was less differences form other land uses in 40-100 cm. The storage of SOC of gullyland (5.04 kg x m(-2)) in subsurface (20-100 cm) was the highest, accounted for 71.4% in 1 m profile, the relative storage of SOC of slopeland and tableland accounted for 63.6% and 72.3% respectively. The storages of SOC of secondary shrubland in subsurface (20-100 cm) were the highest, it was 6.01 kg x m(-2) accounted for 64.7% in 1 m profile, while the relative storage of secondary woodland was the lowest, only accounted for 49.7%. The storages of SOC of farmland and orchard both accounted for more than 70% of 1 m profile.