Different seasonal dynamics, ecological drivers, and assembly mechanisms of algae in southern and northern drinking water reservoirs.

The role of environmental factors on the community structure of algae has been intensively studied, but there are few analyses on the assembly mechanism of the algal community structure. Here, changes in the community structure of algae in different seasons, the effects of environmental variables on the algal community structure, and the assembly mechanism of the algal community structure in northern and southern reservoirs were investigated in this study. The study revealed that Bacillariophyta, Cyanophyta, and Chlorophyta were the predominant algal species in the reservoirs, with Bacillariophyta and Cyanophyta exhibiting seasonal outbreaks. Compared to the northern reservoirs, the algal diversity in the southern reservoirs was greater. The diversity and algal community structure could be significantly impacted by variations in water temperature and nitrogen level. According to the ecological model, the interaction among algal communities in reservoirs was primarily cooperation. The key taxa in the northern reservoirs was Aphanizomenon sp., while the outbreak in the southern reservoirs was Coelosphaerium sp. The community formation pattern of reservoirs was stochastic, with a higher degree of explanation observed in the southern reservoirs compared to the northern reservoirs. This study preliminarily explored the assembly mechanism of the algal community, providing a theoretical basis for the control of eutrophication in drinking water reservoirs.

Temporal patterns of algae in different urban lakes and their correlations with environmental variables in Xi'an, China.

Urban lakes were critical in aquatic ecology environments, but how environmental factors affected the distribution and change characteristics of algal communities in urban lakes of Xi'an city was not clearly. Here, we investigated the algal community structure of six urban lakes in Xi'an and evaluated the effects of water quality parameters on algae. The results indicated that the significant differences on physicochemical parameters existed in different urban lakes. The maximum concentration of total phosphorus in urban lakes was (0.18 ± 0.01) mg/L and there was a phenomenon of phosphorus limitation. In addition, 51 genera of algae were identified and Chlorella sp. was the dominant algal species, which was affiliated with Chlorophyta. Network analysis elucidated that each lake had a unique algal community network and the positive correlation was dominant in the interaction between algae species, illustrating that mature microbial communities existed or occupied similar niches. Redundancy analysis illustrated that environmental factors explained 47.35% variance of algal species-water quality correlation collectively, indicating that water quality conditions had a significant influence on the temporal variations of algae. Structural equation model further verified that algal community structure was directly or indirectly regulated by different water quality conditions. Our study shows that temporal patterns of algal communities can reveal the dynamics and interactions of different urban ecosystem types, providing a theoretical basis for assessing eutrophication levels and for water quality management.

Effects of Wenxiao Decoction on the expression of interleukin-6, intercellular adhesion molecular-1 and monocyte chemoattractant protein-1 in experimental atherosclerotic rabbits.

OBJECTIVE: To observe the effects of different doses of Wenxiao Decoction on the expression of interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemoattractant protein-1 (MCP-1) in experimental atherosclerotic rabbits and to explore the mechanism by which it alleviates atherosclerosis. METHODS: Sixty New Zealand rabbits were randomly divided into six groups: a blank group, a model group, a Simvastatin group, and high-, medium-, and low-dosage Wenxiao Decoction groups. Except for those in the blank group, all rabbits were fed with a high-cholesterol diet. Carotid atherosclerosis was established by balloon-induced carotid artery endothelium injury in conjunction with the high-cholesterol diet. After 8 weeks, all animals were euthanized to evaluate levels of IL-6 and ICAM-1 expressions (by enzyme linked immunosorbent assay) and of MCP-1 (by immunohistochemistry staining). RESULTS: The expressions of IL-6, ICAM-1, and MCP-1 were significantly increased in all groups except the blank group (P<0.05). However, the rabbits in the Wenxiao Decoction groups and the Simvastatin group showed significantly lower levels of IL-6, ICAM-1, and MCP-1 expression than those in the model group (P<0.05). The expressions of IL-6, ICAM-1, and MCP-1 in the highdosage Wenxiao Decoction group and the Simvastatin group were lower than those in the low-dosage Wenxiao Decoction group (P<0.05). The expression of MCP-1 in medium-dosage Wenxiao Decoction group was lower than that in the low-dosage group (P<0.05). CONCLUSIONS: High, medium, and low doses of Wenxiao Decoction can inhibit the expressions of IL-6, ICAM-1, and MCP-1, which may prevent and stabilize atherosclerotic plaques. There may be a direct relationship between dosage and therapeutic efficacy of Wenxiao Decoction.

Effects of Wenxiao II decoction on the expression of MCP-1 and VCAM-1 in atherosclerotic rabbits.

OBJECTIVE: To observe the effects of different doses of wenxiao II decoction on the expression of monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) in an experimental model of atherosclerosis in rabbits and to explore the mechanism by which it alleviates atherosclerosis. METHODS: Sixty 3-4 month-old New Zealand rabbits of both sexes were randomly divided into six groups: simvastain; model; blank; and high-dose, mid-dose, and low-dose wenxiao II decoction groups. Except for those in the blank group, all rabbits were fed a high-cholesterol diet. Carotid atherosclerosis was established by balloon-induced injury to the endothelium of the carotid artery in conjunction with consumption of a high-cholesterol diet. After 8 weeks, all rabbits were killed to evaluate the expression of MCP-1 and VCAM-1 by immunohistochemical staining. RESULTS: Expressions of MCP-1 and VCAM-1 were significantly decreased in all groups except the blank group compared with the model group (P < 0.05). When compared with the simvastain group only variation of MCP-1 expression in low-dose group was not appreciable, and the differences were indistinct (P < 0.05). When comparing among wenxiao II decoction groups, MCP-1 expression in the mid- and high-dose groups was significantly lower than that seen in the low-dose group (P< 0.01), but there were no differences among three dosage groups with respect to VCAM-1 expression (P > 0.05). CONCLUSION: These data suggested that high, mid, and low doses of Wenxiao II Decoction can inhibit the expression of MCP-1 and VCAM-1, which may prevent the formation of or stabilize atherosclerotic plaques. There may be a direct relationship between the dosage of wenxiao II decoction and its therapeutic efficacy.