Evaluating and diagnosing ecosystem health of the "three-lake" watershed in Yuxi, Yunnan, China from 2010 to 2020 by PSR-KDE.

To carry out the diagnosis and evaluation of the ecosystem health in Yuxi three-lake watershed, this paper presents the changing trend of its health state, and predicts the future development. This also provides ideas for maintaining the regional ecosystem health, and then gradually improves the ecological environment quality. Taking Fuxian Lake, Qilu Lake and Xingyun Lake (the three-lake watershed) in Yuxi City, Yunnan Province, Southwest China as the research object, a model combining pressure-state-response and kernel density estimation (PSR-KDE) adopts to diagnose and evaluate the ecosystem health of the "three lake" watershed from 2010 to 2020, and the distribution map of ecosystem health index has obtained by the evaluation indexes integration based on GIS spatial analysis. Hence, the evaluation results have visualized on the map. The results show that: The distribution of ecosystem health index in the study area was 0.1530-0.7045 in 2010, 0.2056-0.7512 in 2015, and 0.2248-0.7662 in 2020. 0.12% was in the pathological area in 2010. After 2015, the pathological condition of ecosystem health has completely solved, and the proportion of unhealthy ecosystems was 11.95% in 2010, 7.38% in 2015, and 5.97% in 2020. The ecosystem health index of the study region was 0.5523 in 2010, 0.5807 in 2015, and 0.5815 in 2020, it indicates that the ecosystem was in a sub-health state. From 2010 to 2020, the ecosystem health around Qilu Lake was the most worrying, followed by the northwest of Fuxian Lake and the northern and southern regions of Xingyun Lake. The ecosystem health of the three-lake watershed showed significant improvement from 2010 to 2020. The study ecosystem health assessment and early warning in the three-lake watershed is significant to the ecological environment protection and management of the plateau lake basin, the restoration of the territorial space ecology and the economic development of the surrounding area.

The impact of land use on eco-environment in the Dianchi Basin.

(1) Studying the dynamic correlation between land use and the eco-environment in the Dianchi Basin is important for improving the basin's spatial layout and enhancing ecological development and conservation; (2) Through dynamic analysis and comprehensive evaluation of land use, the introduction of ecological and environmental quality index, and the use of FLUS models, the impacts on eco-environments in the Dianchi Basin for the recent 20 years were analyzed; (3) The past two decades witnessed a constant increase in the construction land in the Dianchi Basin and a decline in the farmland at an average annual rate of 0.93 %; The utilization level of land in the Dianchi Basin presented a negative correlation with the quality of the area's eco-environment, which reduces first and then increases; When natural production becomes a priority, both the construction land and farmland have witnessed growth. However, when ecological protection becomes a priority, it is projected that by 2035, the Dianchi Basin will achieve its highest eco-environmental quality index; (4) Studying how the change of land use types affects eco-environment is crucial for optimizing the current allocation of land resources and promoting sustainable development in the basin.

A monocarboxylate transporter-dependent mechanism confers resistance to exercise-induced fatigue in a high-altitude hypoxic environment.

The body is more prone to fatigue in a high-altitude hypoxic environment, in which fatigue occurs in both peripheral muscles and the central nervous system (CNS). The key factor determining the latter is the imbalance in brain energy metabolism. During strenuous exercise, lactate released from astrocytes is taken up by neurons via monocarboxylate transporters (MCTs) as a substrate for energy metabolism. The present study investigated the correlations among the adaptability to exercise-induced fatigue, brain lactate metabolism and neuronal hypoxia injury in a high-altitude hypoxic environment. Rats were subjected to exhaustive incremental load treadmill exercise under either normal pressure and normoxic conditions or simulated high-altitude, low-pressure and hypoxic conditions, with subsequent evaluation of the average exhaustive time as well as the expression of MCT2 and MCT4 in the cerebral motor cortex, the average neuronal density in the hippocampus, and the brain lactate content. The results illustrate that the average exhaustive time, neuronal density, MCT expression and brain lactate content were positively correlated with the altitude acclimatization time. These findings demonstrate that an MCT-dependent mechanism is involved in the adaptability of the body to central fatigue and provide a potential basis for medical intervention for exercise-induced fatigue in a high-altitude hypoxic environment.

Monocarboxylate transporter-dependent mechanism is involved in the adaptability of the body to exercise-induced fatigue under high-altitude hypoxia environment.

Under high-altitude hypoxia environment, the body is more prone to fatigue, which occurs in both peripheral muscles and the central nervous system (CNS). The key factor determining the latter is the imbalance of brain energy metabolism, which makes it difficult to maintain the central nervous system to send peripheral nerve impulse continuously. During strenuous exercise, lactate released from astrocytes is taken up by neurons stored for energy to maintain synaptic transmission, a process mediated by monocarboxylate transporters (MCTs) in CNS. The present study investigated the correlation among the adaptability to exercise-induced fatigue, brain lactate metabolism and neuronal hypoxia injury under high-altitude hypoxia environment. Rats were subjected to exhaustive incremental load treadmill exercise under either normal pressure and normoxic conditions or simulated high-altitude low pressure and hypoxic conditions, with subsequent evaluation of the average exhaustive time as well as the expression of monocarboxylate transporters 2 (MCT2), MCT4, the average neuronal density in the cerebral motor cortex, and the lactate content in rat brain. At the early stage of simulated high-altitude environment, the average exhaustive time and neuronal density of rats decreased rapidly, then gradually recovered to some extent with the extension of altitude acclimatization time. The expression of MCT2, MCT4 and the lactate content in rat brain also increased gradually with the extension of altitude acclimatization time. After the application of lactate transport inhibitor, the recovery of exercise capacity of rats after altitude acclimatization was quickly blocked, and the neuronal injury in the cerebral motor cortex of rats was also significantly aggravated. These findings demonstrate that MCT-dependent mechanism is involved in the adaptability of the body to central fatigue, and provide a potential basis for medical intervention for exercise-induced fatigue under high-altitude hypoxia environment.

Enantioseparation of Timolol on a Novel ß-Cyclodextrin Derivative Chiral Stationary Phase in HPLC.

A novel chiral stationary phase was prepared by bonding a novel ß-cyclodextrin derivative on silica gel, and it was used for the separation of timolol in high efficiency liquid phase. In the reverse mode, the factors such as the proportion of chiral additives, flow rate, column temperature, repeatability and stability were investigated. The optimum chromatographic conditions are as follows: column temperature was 25°C, flow rate was 0.6 mL min(-1) and mobile phase was methanol-25 mM KH2PO4 (80/20, v/v). The chiral column has good reproducibility (Rs = 4.49, 4.51 and 4.40, respectively) and a certain degree of stability (Rs = 4.49, 3.01 and 0.72, respectively). This chiral stationary phase presented good chiral recognition performance toward timolol with good resolution (Rs = 4.49).

Preparation and enantioseparation characteristics of a novel ß-cyclodextrin derivative chiral stationary phase in high-performance liquid chromatography.

A novel cyclodextrin (CD) derivative mono(6(A)-N-allylamino-6(A)-deoxy)per-3-chlorine-4-methyl-phenylcarbamoylated-ß-CD was synthesized and chemically immobilized onto the surface of γ-mercaptopropyl-functionalized silica gel step by step. The products were all purified and characterized and then got a substance with definitional structure. This chiral stationary phase (CSP) of 3-chlorine-4-methyl-phenylcarbamoylated-ß-CD bonded on silica gel exhibited excellent separation capability for several chiral compounds in high-performance liquid chromatography. In the enantiomeric separations of five racemates with a mixture of methanol and aqueous KH2PO4 buffer as the mobile phase, this CSP presented good chiral recognition performance.