Ligustrazine Inhibits the Migration and Invasion of Renal Cell Carcinoma

Ligustrazine is a Chinese herb (Chuanxiong) approved for use as a medical drug in China. Recent evidence suggests that ligustrazine has promising antitumor properties. Our preliminary results showed that ligustrazine could inhibit the growth of human renal cell carcinoma (RCC) cell lines. However, the complicated molecular mechanism has not been fully revealed. Therefore, the purpose of this study to investigate the mechanism of ligustrazine resistance in human RCC cells. Cell proliferation, migration, invasion, and colony-formation ability of RCC cells A498 were detected by MTT assay, clonal formation rates, and transwell chamber assay in vitro. The expression of epithelial–mesenchymal transition (EMT)–related proteins were analyzed using western blot test. The effect of ligustrazine on the growth of A498 cells in nude mice was investigated in vivo. Our results showed that ligustrazine could significantly inhibit the proliferation, migration, and invasion of A498 both in vivo and vitro. Western blot analysis showed that the expressions of EMT-related, N-cadherin, snail, and slug proteins were significantly decreased in A498 in the ligustrazine treatment group. This study indicated that ligustrazine could significantly inhibit the malignant biological behaviors of RCC cell lines, possibly by inhibiting the EMT process

Active optical clock based on four-level quantum system

Active optical clock, a new conception of atomic clock, has been proposed recently. In this report, we propose a scheme of active optical clock based on four-level quantum system. The final accuracy and stability of two-level quantum system are limited by second-order Doppler shift of thermal atomic beam. To three-level quantum system, they are mainly limited by light shift of pumping laser field. These limitations can be avoided effectively by applying the scheme proposed here. Rubidium atom four-level quantum system, as a typical example, is discussed in this paper. The population inversion between $6S_{1/2}$ and $5P_{3/2}$ states can be built up at a time scale of $10^{-6}$s. With the mechanism of active optical clock, in which the cavity mode linewidth is much wider than that of the laser gain profile, it can output a laser with quantum-limited linewidth narrower than 1 Hz in theory. An experimental configuration is designed to realize this active optical clock.Comment: 5 page

Ligustrazine Inhibits the Migration and Invasion of Renal Cell Carcinoma

Ligustrazine is a Chinese herb (Chuanxiong) approved for use as a medical drug in China. Recent evidence suggests that ligustrazine has promising antitumor properties. Our preliminary results showed that ligustrazine could inhibit the growth of human renal cell carcinoma (RCC) cell lines. However, the complicated molecular mechanism has not been fully revealed. Therefore, the purpose of this study to investigate the mechanism of ligustrazine resistance in human RCC cells. Cell proliferation, migration, invasion, and colony-formation ability of RCC cells A498 were detected by MTT assay, clonal formation rates, and transwell chamber assay in vitro. The expression of epithelial–mesenchymal transition (EMT)–related proteins were analyzed using western blot test. The effect of ligustrazine on the growth of A498 cells in nude mice was investigated in vivo. Our results showed that ligustrazine could significantly inhibit the proliferation, migration, and invasion of A498 both in vivo and vitro. Western blot analysis showed that the expressions of EMT-related, N-cadherin, snail, and slug proteins were significantly decreased in A498 in the ligustrazine treatment group. This study indicated that ligustrazine could significantly inhibit the malignant biological behaviors of RCC cell lines, possibly by inhibiting the EMT process

Spatial-Temporal Variations in of Soil Conservation Service and Its Influencing Factors under the Background of Ecological Engineering in the Taihang Mountain Area, China

Soil conservation (SC) plays an important role in maintaining regional land productivity and sustainable development. Ecological engineering (EE) is being implemented in different countries to effectively alleviate the damage to the ecological environment and effectively protect soil and food security. It is important to determine whether or not the SC capacity becomes stronger after the implementation of EE and whether or not EE has a notable impact on SC in different altitude zones. The exploration of the influencing mechanism and identification of the dominate influencing factors in different geographical regions needs to be improved. In this study, the soil conservation services (SCSs) from 1980 to 2020 in the Taihang Mountain area was assessed using the integrated valuation of ecosystem services and trade-offs (InVEST) model, and the spatial and temporal distributions and influencing factors were explored. The results showed the following: (1) the average SCSs exhibited an increasing trend from 1980 to 2020 on the whole, and the rate of increase reached 50.53% during the 41-year period. The rate of increase of the SCSs varied in the different EE implementation regions, and it was significantly higher than that of the entire study area. (2) The spatial distribution of the SCSs was highly heterogeneous, and the high SCS value areas were coincident with the high-altitude areas where forest and grassland occupied a large proportion. The low value areas were mainly located in the hilly zone or some of the basin regions where the proportion of construction land was relatively high. (3) The distribution pattern of the SCSs was the result of multiple factors. The EE intensity had the strongest explanatory power for the SCSs in the hilly zone, explaining 34.63%. The slope was the most critical factor affecting the SCSs in the mid-mountain and sub-alpine zones. The slope and normalized difference vegetation index (NDVI) had the greatest interactions with the other factors in the three altitude zones, especially in the high-altitude regions. The quantitative analysis of the SCSs and the influences of EE and natural factors on the SCSs revealed the heterogeneity in the mountainous areas. These results also provide a scientific basis for the reasonable implementation of EE and sustainable management of SCSs in the Taihang Mountain area

Characteristics and spatial–temporal patterns of supply and demand of ecosystem services in the Taihang Mountains

Research on the spatial–temporal pattern of the supply and demand associated with ecosystem services(ESs) is of great significance for regional sustainable development. Due to their high spatial heterogeneity, the relationship between supply and demand of ESs in mountainous areas in particular needs to be further studied. This paper examines the supply and demand of ESs in the Taihang Mountains from 2000 to 2018 at both the whole-region and county scale to evaluate supply–demand patterns, the nature and resilience of the supply–demand relationship, and to analyze spatiotemporal variation and characteristics, which can provide a basis for the coordination and sustainable management of the supply and demand relationship of the ecosystem. Our results showed that during the study period: （1)the ecosystem services supply(ESS) increased by 2.36% and the ecosystem services demand(ESD) increased by 50.93%,the increase in the rate of ESS was far less than that of ESD and on the county scale, the ESS of 20% of the counties decreased whereas and the ESD of all counties increased.（2)the supply and demand pattern of the Taihang Mountains remained basically unchanged，the types of supply and demand in the Taihang Mountains are mainly low supply-high demand, low supply-low demand, and high supply-low demand, accounting for>90% of the total county number.（3)the average supply and demand index of high altitude counties is more than five times that of low altitude counties.The average supply and demand index of counties with low economic growth rate is twice that of the high economic growth rate.（4)67% of counties reduced the resilience level of total ecosystem services（TES), the resilience level of the provisioning services(PS) decreased most significantly, reaching 76%

Metabolic mechanism of astaxanthin biosynthesis in Xanthophyllomyces dendrorhous in response to sodium citrate treatment

Abstract Astaxanthin is an important ketocarotenoid widely used in industries. However, its application is limited because of its low yield. Sodium citrate (Na-citrate), one of the major carbon sources for microorganisms, can promote cell growth and product accumulation. The basidiomycetous red yeast Xanthophyllomyces dendrorhous was thus used to study the effect of Na-citrate on cell growth and astaxanthin synthesis. The highest biomass and astaxanthin yield (6.0 g/L and 22.5 mg/L) were obtained in shake-flask when 3 g/L Na-citrate was added at 24 h and were 1.8 and 2.0 times higher than those of the control group, respectively. Furthermore, metabolomics and real-time reverse transcription PCR (qRT-PCR) analysis were conducted to study the metabolic pathways of X. dendrorhous in response to Na-citrate. The qRT-PCR assay revealed that Na-citrate facilitated glucose consumption, promoted the metabolic flux from glycolysis, and regulated the tricarboxylic acid (TCA) cycle, providing more energy and substrates for the synthesis of astaxanthin. The gene analysis revealed that adding Na-citrate significantly upregulated the expression of six key genes (ICL, HMGS, crtE, crtYB, crtI, and crtS) involved in pathways related to astaxanthin biosynthesis. These results suggest that exogenous Na-citrate treatment is a potentially valuable strategy to stimulate astaxanthin production in X. dendrorhous

Additional file 1 of Metabolic mechanism of astaxanthin biosynthesis in Xanthophyllomyces dendrorhous in response to sodium citrate treatment

Additional file 1: Figure S1. Effect of 2 g/L Na-citrate addition at different times on the growth and astaxanthin production of X. dendrorhouos. (A) Biomass (g/L); (B) Carotenoids titer (mg/L); (C) Astaxanthin titer (mg/L); (D) Astaxanthin content (mg/g). The cells were grown in a 250-mL Erlenmeyer flask containing 50 mL fermentation medium, with the temperature maintained at 22°C and the stirring speed at 200 rpm. Values are mean ± standard deviation of three independent experiments. Figure S2. Effect of different Na-citrate concentrations at 24 h on the growth and astaxanthin production of X. dendrorhouos. (A) Biomass (g/L); (B) Carotenoids titer (mg/L); (C) Astaxanthin titer (mg/L); (D) Astaxanthin content (mg/g). The cells were grown in a 250-mL Erlenmeyer flask containing 50 mL fermentation medium, with the temperature maintained at 22°C and the stirring speed at 200 rpm. Values are mean ± standard deviation of three independent experiments. Figure S3. Na-citrate regulates the protein content in X. dendrorhouos. fold change is the ratio of the protein content of the control group to the Na-citrate group. Table S1. Gene-specific primers used for RT-qPCR; F: Forward; R: Revers