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To explore the causes of the ecological environment deterioration of lakes in the Inner Mongolia Plateau, this study took a typical inland lake Daihai as an example, and investigated the groundwater recharge in the process of lake shrinkage and eutrophication. Using the radon isotope (222Rn) as the main means of investigation, the 222Rn mass balance equation was established to evaluate the groundwater recharge in Daihai. The spatial variability of 222Rn activity in lake water and groundwater, the contribution of groundwater recharge to lake water balance and its effect on nitrogen and phosphorus pollution in lake water were discussed. The analysis showed that, mainly controlled by the fault structure, the activity of 222Rn in groundwater north and south of Daihai is higher than that in the east and west, and the difference in lithology and hydraulic gradient may also be the influencing factors of this phenomenon. The 222Rn activity of the middle and southeast of the underlying lake is greater, indicating that the 222Rn flux of groundwater inflow is higher, and the runoff intensity is greater, which is the main groundwater recharge area for the lake. The estimated groundwater recharge in 2021 was 3 017×104 m3, which was 57% of the total recharge to the lake, or 1.6 times and 8.1 times that of precipitation and surface runoff. The TN and TP contents in Daihai have been rising continuously, and the average TN and TP concentrations in the lake water in 2021 were 4.21 mg·L−1 and 0.12 mg·L−1, respectively. The TN and TP contents entering the lake with groundwater recharge were 6.8 times and 8.7 times above those of runoff, accounting for 87% and 90% of the total input, respectively. The calculation results showed that groundwater is not only the main source of recharge for Daihai, but also the main source of exogenous nutrients. In recent years, the pressurized exploitation of groundwater in the basin is beneficial in increasing the groundwater recharge to the lake, reducing the water balance difference of the lake, and slowing down the shrinking degree of the lake surface. However, under the action of high evaporation, nitrogen and phosphorus brought by groundwater recharge would become more concentrated in the lake, leading to a continuous increase in the content of nutrients and degree of eutrophication. Therefore, the impact of changes in regional groundwater quantity and quality on Daihai is an important issue that needs further assessment.

Five global monthly top-of-atmosphere (TOA) outgoing longwave radiation (OLR) products are evaluated in this study, including the products derived from the High-Resolution Infrared Radiation Sounder (HIRS), Clouds and the Earth's Radiant Energy System (CERES), Advanced Very High Resolution Radiometer (AVHRR), the CM SAF cLoud, Albedo and surface RAdiation dataset from AVHRR data (CLARA), and the Global Energy and Water Cycle EXchanges (GEWEX) project. Results show that overall there is good consistency among these five products. Larger differences are found between GEWEX and CERES (HIRS) after (before) 2000 (RMSE ~ 5 W/m2), particularly in the tropical regions. In terms of global mean values, GEWEX shows large differences with the other products from the year 1992 to 2002, and CLARA shows large differences from the year 1979 to 1981, which are more obvious in the global ocean values. Large discrepancies among these products exist at low latitudinal bands, particularly before the year 2000. Australia and Asia (mid–low latitude part) are two typical regions in which larger differences are found. [ABSTRACT FROM AUTHOR]

Objective: To investigate the diagnostic value of the combined detection of α-hydroxybutyrate dehydrogenase (α-HBDH), carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125) in early-stage breast cancer (ESBC)., Methods: This was a retrospective analysis of 169 patients with ESBC, 138 patients with benign breast disease (BBD) and 200 normal healthy controls (NHCs). The levels of serum α-HBDH, CEA and CA125 in the two groups were detected. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to analyse the diagnostic value of the above indicators alone and in combination for ESBC., Results: The levels of α-HBDH, CEA and CA125 in the ESBC group were significantly higher than those in the BBD and NHC groups ([118.18 ± 11.19 vs 91.24 ± 9.17 vs 89.38 ± 9.01, F = 6.189, p = 0.004], [2.39 ± 1.12 vs 1.48 ± 0.76 vs 1.58 ± 0.58, F = 5.362, p = 0.017] and [14.44 ± 6.78 vs 11.19 ± 3.17 vs 7.18 ± 4.71, F = 8.912, p = 0.001], respectively). In the ESBC group, the positive rate of combined detection was higher than that of single detection (96.12% vs 72.64% vs 53.67% vs 42.41%, X 2 = 27.174, p < 0.05). ROC curve analysis showed that serum α-HBDH, CEA, CA125 alone and combined detection in the diagnosis of ESBC. The sensitivity was 48.1%, 63.6%, 44.2% and 54.5%, the specificity was 75.4%, 75.4%, 86.0% and 91.2% and the AUC was 0.654, 0.715, 0.636 and 0.772, respectively. The diagnostic value of combined detection was the highest., Conclusion: The levels of serum α-HBDH, CEA and CA125 in ESBC are high, and the combined detection of the three has a high diagnostic value for ESBC., Competing Interests: The authors declare that they have no competing interests in this work., (© 2023 Zhan and Liu.)