Category: Statistics

J Magn Reson Imaging. 2024 Mar 12. doi: 10.1002/jmri.29344. Online ahead of print.

ABSTRACT

BACKGROUND: Early and accurate identification of lymphatic node metastasis (LNM) and lymphatic vascular space invasion (LVSI) for endometrial cancer (EC) patients is important for treatment design, but difficult on multi-parametric MRI (mpMRI) images.

PURPOSE: To develop a deep learning (DL) model to simultaneously identify of LNM and LVSI of EC from mpMRI images.

STUDY TYPE: Retrospective.

POPULATION: Six hundred twenty-one patients with histologically proven EC from two institutions, including 111 LNM-positive and 168 LVSI-positive, divided into training, internal, and external test cohorts of 398, 169, and 54 patients, respectively.

FIELD STRENGTH/SEQUENCE: T2-weighted imaging (T2WI), contrast-enhanced T1WI (CE-T1WI), and diffusion-weighted imaging (DWI) were scanned with turbo spin-echo, gradient-echo, and two-dimensional echo-planar sequences, using either a 1.5 T or 3 T system.

ASSESSMENT: EC lesions were manually delineated on T2WI by two radiologists and used to train an nnU-Net model for automatic segmentation. A multi-task DL model was developed to simultaneously identify LNM and LVSI positive status using the segmented EC lesion regions and T2WI, CE-T1WI, and DWI images as inputs. The performance of the model for LNM-positive diagnosis was compared with those of three radiologists in the external test cohort.

STATISTICAL TESTS: Dice similarity coefficient (DSC) was used to evaluate segmentation results. Receiver Operating Characteristic (ROC) analysis was used to assess the performance of LNM and LVSI status identification. P value <0.05 was considered significant.

RESULTS: EC lesion segmentation model achieved mean DSC values of 0.700 ± 0.25 and 0.693 ± 0.21 in the internal and external test cohorts, respectively. For LNM positive/LVSI positive identification, the proposed model achieved AUC values of 0.895/0.848, 0.806/0.795, and 0.804/0.728 in the training, internal, and external test cohorts, respectively, and better than those of three radiologists (AUC = 0.770/0.648/0.674).

DATA CONCLUSION: The proposed model has potential to help clinicians to identify LNM and LVSI status of EC patients and improve treatment planning.

EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

PMID:38471960 | DOI:10.1002/jmri.29344

Huan Jing Ke Xue. 2024 Feb 8;45(2):909-919. doi: 10.13227/j.hjkx.202303229.

ABSTRACT

Based on the typical city survey data and statistics of Guangdong Province， a 2018-based 3 km×3 km gridded greenhouse gas emissions inventory was developed for Guangdong Province using the combination of top-down and bottom-up emission factor methods. The inventory covered the CO₂， CH_4， and N₂O emissions from energy， industrial processes， agriculture， land use change and forest， waste management， and indirect sources. The results showed that estimates for CO₂， CH₄， and N₂O in Guangdong Province for the year 2018 were 8.5×10⁸， 1.9×10⁶， and 1.1×10⁵ t， respectively， and 8.5×10⁸， 4.0×10⁷， and 3.4×10⁷ t by equivalent carbon dioxide， totaling 9.2×10⁸ t. CO₂ was the main greenhouse gas in Guangdong Province， accounting for 92.0% of the total emissions. Energy and indirect sources were the main emission sources， accounting for 77.9% and 7.6%， respectively， totaling 85.5%. Spatial distributions illustrated that most grids were greenhouse gas emissions， whereas some others were greenhouse gas sinks； the greenhouse gas emissions were distributed mainly in the Pearl River Delta region and had certain characteristics of distribution along the road network and channels. The greenhouse gas grids of high emission were mainly the locations of high energy-consuming enterprises such as large power plants， steel mills， and cement plants.

PMID:38471929 | DOI:10.13227/j.hjkx.202303229

Huan Jing Ke Xue. 2024 Feb 8;45(2):826-836. doi: 10.13227/j.hjkx.202303226.

ABSTRACT

In order to better support the construction of the capital water conservation functional area and ecological environment support area， research on the chemical characteristics of groundwater and its formation mechanism in the dry period in the Zhangjiakou area can provide a great reference for the rational development and utilization of groundwater resources. A total of 41 groups of groundwater samples were collected， and the hydrochemical types， composition characteristics， and control factors of groundwater in the study area were analyzed by using the combined method of descriptive statistical analysis， Piper triplot， correlation analysis， Gibbs plot， and ion ratio. The results showed that the groundwater in the study area was weakly alkaline， with the total hardness and ρ（TDS） ranging from 105.00 mg·L^-1 to 1 433.00 mg·L^-1 and 137.00 mg·L^-1 to 2 286.00 mg·L^-1， respectively. The total hardness and TDS mass concentrations of groundwater in the Bashang area were higher than those in the Baxia area. HCO₃^– and Na⁺ were the main dominant anions and cations in the groundwater in the study area. The highest overstandard rate of the main components in groundwater was that of total hardness （36.59%）. The overstandard rate and maximum excess multiple of each component in groundwater in the Bashang area were greater than those in the Baxia area. HCO₃-Ca·Mg·Na was the main type of groundwater hydrochemistry in the study area， and there was little difference between the Bashang area and the Baxia area. SO₄^2-， Cl^–， HCO₃^–， Na⁺， and Mg²⁺ contributed the most to TDS. The chemical characteristics of groundwater were affected by weathering and filtration of rock minerals such as salt rock， albite， and dolomite； cation exchange； and human activities. Evaporative crystallization and atmospheric precipitation contributed to a small part of the main ion source of groundwater in the area. The effect of human activities on groundwater in the Bashang area was greater than that in the Baxia area， and NO₃^– mainly originated from agricultural activities.

PMID:38471921 | DOI:10.13227/j.hjkx.202303226

Huan Jing Ke Xue. 2024 Feb 8;45(2):813-825. doi: 10.13227/j.hjkx.202303158.

ABSTRACT

Chaohu lake is a key water body for water pollution prevention and treatment in our country. However， it has been at a higher eutrophication level recently. Here， the surface water and groundwater in the Dianbu River Basin， a secondary tributary of Chaohu Lake， were taken as the research object. In order to test the hydrochemical composition and hydrogen and oxygen isotope values of different water bodies， 30 groups of surface water samples， 36 groups of groundwater samples， 16 groups of hydrogen and oxygen stable isotope samples， and 18 groups of groundwater hydrogen and oxygen stable isotope samples were collected in August 2021 （wet season）， November 2021 （normal season）， and February 2022 （dry season）. The seasonal and spatial variation characteristics were analyzed to explore the hydrochemical characteristics and formation mechanism of water bodies by means of mathematical statistics， Piper triangular diagram， Gibbs figures， and ion ratios. The following results were obtained： ① precipitation was the main source of surface water and groundwater in Dianbu River Basin， and the evaporation fractionation effect of surface water was more significant than that of groundwater. At different periods， the surface water was more enriched with stable isotopes of hydrogen and oxygen than groundwater. The stable isotopes of hydrogen and oxygen in water showed seasonal variation， relative enrichment in the wet season， and depletion in the dry season. ② Both surface water and groundwater in the Dianbu River Basin were weakly alkaline， and the concentration of ions in surface water was significantly lower than that in groundwater. Ca²⁺ and Na⁺ were the main cations in surface water， Ca²⁺ was the main cation in groundwater， and the dominant anion in all water was HCO₃^–. The hydrochemical typology of surface water was mainly HCO₃·Cl-Na·Ca， and that of groundwater was mainly HCO₃-Na·Ca. ③ The concentrations of the main hydrochemical indexes of surface water and groundwater showed certain seasonal and spatial differences. From the wet season to the dry season， the concentrations of TDS， K⁺， Na⁺， Ca²⁺， Mg²⁺， Cl^–， and SO₄^2- in surface water showed an increasing trend on the whole. The concentrations of Na⁺， Ca²⁺， and Mg²⁺ in groundwater showed little change but increased slightly， whereas the concentrations of Cl^–， SO₄^2-， and NO₃^– showed an increasing trend on the whole. The concentrations of Cl^–， SO₄^2-， and NO₃^– in the water showed relatively large seasonal fluctuations. From upstream to downstream， the concentrations of the main hydrochemical indexes in surface water first decreased and then increased， among which the concentration of NO₃^– increased the most. The concentrations of the main hydrochemical indexes of groundwater in the direction of runoff changed little overall， but the concentration in the discharge area was higher than that in the recharge area. ④ The formation of hydrochemical characteristics of the water was mainly controlled by water-rock interaction but was also influenced by human factors. The water-rock action was mainly the weathering dissolution of silicate rock， salt rock， and carbonate rock. Man-made pollutants such as sewage from a sewage treatment plant， domestic sewage， and feces had obviously changed the hydrochemical characteristics of the local water. ⑤ Compared with that in 2016， the concentration of NO₃^– in surface water showed a certain degree of reduction. The nitrogen pollution control work carried out by the local government had achieved certain results， but it was still necessary to strengthen the pollution prevention and control of sewage and feces in the downstream of the Dianbu River， some tributaries （such as the Dingguang River and Maqiao River）， and some residential areas.

PMID:38471920 | DOI:10.13227/j.hjkx.202303158

Huan Jing Ke Xue. 2024 Feb 8;45(2):802-812. doi: 10.13227/j.hjkx.202303190.

ABSTRACT

As an important water supply source in Beijing， karst groundwater has played an irreplaceable role in the security of urban water supply and ecological environment protection in the past 70 years. The Xishan karst groundwater system， located in the upper reaches of western Beijing， belongs to ecological conservation areas. There are several centralized water supply fields in this area. In this study， the Xishan karst groundwater system was taken as the research object. A total of 120 karst groundwater samples in this area were investigated by using statistical analysis， ion ratio， and principal component analysis （PCA） methods to explore the spatial distribution characteristics and formation mechanism of groundwater hydrochemistry. The research results showed that： ① the groundwater quality of the Xishan system was generally good， with the characteristics of neutral pH and low salinity. A total of 84.17% of the water samples were classified as hard water. The chemical type of groundwater was mainly HCO₃-Ca·Mg. ② The chemical composition of groundwater was mainly affected by the water-rock interaction， and the weathering source of rock was mainly the dissolution of carbonate. ③ The results of principal component analysis showed that 34.41% of the chemistry formation of groundwater could be explained by carbonate dissolution， 27.33% by rock salt and evaporate dissolution， 11.76% by aquifer sediment dissolution， and 10.30% by domestic sewage discharge. From the recharge area to the runoff area and then to the discharge area， the TH and TDS gradually increased. Coal mining drainage and human activities were the main factors that caused groundwater degradation and variable hydrochemical types in the piedmont. In the future， it is necessary to further strengthen environmental governance， control point and non-point source pollution， and continuously monitor key areas to provide scientific support for ecological and environmental protection.

PMID:38471919 | DOI:10.13227/j.hjkx.202303190

Huan Jing Ke Xue. 2024 Feb 8;45(2):768-779. doi: 10.13227/j.hjkx.202303032.

ABSTRACT

Relationships between land use and water quality of rivers and lakes vary spatially and temporally. These variations were analyzed using spatial analysis and mathematical statistical methods for the Suzhou Creek in Shanghai. Based on the data of water quality and land use in 2001， 2005， 2010， 2015， and 2020， five spatial scales （200， 500， 1 000， 2 000， and 5 000 m reach buffer） of the landscape pattern were extracted using correlation and redundancy analysis to explore the impact of land use composition and spatial pattern on water quality at different spatial and temporal scales. The results showed that： ① the water quality of Suzhou Creek has gradually improved in the past 20 years； other indicators were between Class II to Class IV in 2020 except TN， and TN was the main pollutant. ② The main land use type of the buffer zone was construction land， and the proportion of greenland and woodland showed a small growth trend. ③ The water quality was closely related to landscape pattern， showing temporal and spatial scale effects. On the time scale， indicators such as construction land， agricultural land， landscape dominance， aggregation， and diversity had significant correlations with various water quality parameters， and there was an inverse correlation in 2010 compared with that in other years for NH₄⁺-N， TP， and TN. The landscape pattern in 2001 had the greatest explanation for water quality， with an explanation rate of 93.65%. The impact of greenland and woodland on water quality has begun to emerge in the past 10 years. ④ On the spatial scale， there were significant correlations between greenland and woodland， patch number， landscape shape index， diversity index， and water quality. There was a strong positive regulatory effect of greenland and woodland on NH₄⁺-N， TP， and TN at the scale of 2 000 m. The patch number and landscape shape index had relatively strong regulatory effects on water quality on a larger spatial scale， whereas the Shannon diversity index had a better positive regulatory effect on water quality on a small scale. The landscape pattern within a buffer of 2 000 m had the highest interpretation degree for all factors， with an explanation rate of 68.47%. The study showed that rationally planning the proportion of greenland and woodland within the 2 000 m buffer zone and optimizing its landscape configuration is an important measure to purify the surface water quality of Suzhou Creek.

PMID:38471916 | DOI:10.13227/j.hjkx.202303032

Huan Jing Ke Xue. 2024 Feb 8;45(2):721-731. doi: 10.13227/j.hjkx.202301093.

ABSTRACT

Based on the existing statistical data of the Lingang Special Area in Shanghai and considering its future socio-economic development， industrial structure， and technological development， a LEAP-Lingang model was developed to analyze the evolution trends of energy demand and carbon emissions under the baseline scenario， low-carbon scenario， and enhanced low-carbon scenario. To enhance the prediction accuracy of the model， the Logistic population growth model was used to predict future population data， and the learning curve model was used to simulate the cost evolution trend of related carbon reduction technologies. In addition， an economic evaluation model for carbon reduction technologies was developed， and the economic costs and emission reduction potential of typical carbon reduction technologies were evaluated by drawing a marginal emission reduction cost curve. The results showed that under the enhanced low-carbon scenario， the renewable energy accounted for 69% of the primary energy consumption， and the electric energy accounted for 91% of the terminal energy demand in 2060. The Lingang Special Area could achieve carbon peak by 2030， and the carbon emissions in 2060 were predicted to decrease by 94% compared to that in the baseline scenario. In terms of contribution to emission reduction， clean energy substitution， industrial structure optimization， and terminal energy efficiency improvement played a key role in reducing carbon emissions near the port. In the medium term （until 2035）， they were predicted to contribute 35.1%， 27.3%， and 16.2% of carbon emissions， respectively， and in the long term （until 2060）， they should contribute 50.6%， 8.75%， and 7.7% of carbon emissions， respectively. Regarding specific carbon reduction technologies， hydrogen power generation； water electrolysis for hydrogen； and carbon capture， utilization， and storage （CCUS） technology were of great significance for achieving net-zero emissions， but the costs of emission reduction were relatively high. The research results can provide ideas and references for the low-carbon and green development of the Lingang Special Area and related areas.

PMID:38471912 | DOI:10.13227/j.hjkx.202301093

Huan Jing Ke Xue. 2024 Feb 8;45(2):655-667. doi: 10.13227/j.hjkx.202303009.

ABSTRACT

Based on the continuous data of O₃， NO， NO₂， and NO_x and the meteorological data from March 2019 to February 2020 at six atmospheric composition observation stations in Shanxi Province， the characteristics and influence factors of O₃ volume fractions were studied using statistical analysis and backward trajectory analysis. The results showed that O₃ volume fractions were generally higher from April to September and lower from October to the following March. During the study period， O₃ pollution represented by φ（MDA8O₃）， i.e.， the maximum daily 8-h average of O₃ volume fractions， was the most serious at the Jincheng and Linfen stations in the south of Shanxi， followed by that in the Wutaishan， Shuozhou， and Datong stations in the north， with the least pollution occurring at the Taiyuan station in the middle. There were differences between the urban and alpine stations， although their seasonal O₃ volume fractions were both summer &gt; spring &gt; autumn &gt; winter. O₃ volume fractions at the urban station were usually lower than those at the alpine station； O₃ at the urban station might have been influenced by photochemical reactions with precursor NO_x； however， this was not the main source of high O₃ at the alpine station. The peak and valley values appeared at 15：00 and 06：00， respectively， at the urban station， whereas they appeared at 20：00 and 10：00， respectively， at the alpine station， representing diametrically opposite diurnal variation patterns. Further， the daily amplitude of O₃ at the urban station was much larger than that at the alpine station. For urban stations specifically， temperature was the most important meteorological factor affecting O₃ volume fraction， compared with sunlight hours， precipitation， and total cloud cover. The NO₂ volume fraction in the daytime affected the daily amplitude of O₃； although the photochemical generation potential of O₃ at the Taiyuan station was good， the O₃ volume fractions were the lowest among urban stations due to strong NO titration. The higher O₃ corresponded to lower NO_x in which NO₂ was dominant， and the higher NO_x was largely composed of NO， under which conditions O₃ would be depleted completely. The surface wind that affected O₃ volume fractions of all stations primarily came from the southeast， south， and southwest， and specific wind speed led to the increase in O₃ volume fraction. The geographical situation of the station would cause the difference in the transport of atmospheric pollutants， whereas the horizontal transmissions of high O₃ from the North China Plain and Fenwei Plain were likely to be the common reason for the increase in O₃ volume fraction in Shanxi.

PMID:38471906 | DOI:10.13227/j.hjkx.202303009

Huan Jing Ke Xue. 2024 Mar 8;45(3):1749-1759. doi: 10.13227/j.hjkx.202304033.

ABSTRACT

The large-scale construction of new districts has led to severe soil heavy metal pollution. Therefore, taking Fengdong New District as the target research area, the descriptive statistics of heavy metal content characteristics and Kriging interpolation analysis have been conducted, and the potential ecological risk index and information diffusion theory were further combined to create an information diffusion model based on risk assessment. Finally, the pollution degree, ecological risk, and risk occurrence probability of Pb, Cu, Cd, and Hg were discussed. The findings revealed that the average concentrations of the four heavy metals far exceeded the background value of soil heavy metals by a factor of 1.943 (Pb), 1.419 (Cu), 3.074 (Cd), and 3.567 (Hg), respectively. Moreover, the distribution of soil heavy metals showed strong variability(CV>65%)owing to human interference. The distribution of Pb and Cu pollution were predominantly influenced by industrial production and land development for construction purposes, whereas industrial activities, agricultural practices, and transportation served as the primary sources of Cd contamination. On the other hand, industrial construction emerged as the major factor contributing to Hg pollution. The average values of individual potential ecological risk index for heavy metals of 9.716 (Pb), 7.095 (Cu), 92.292 (Cd), and 142.469 (Hg), coupled with the regional comprehensive potential ecological risk index (RI) average of 251.573, signified that the region was overall characterized by a relatively high potential ecological risk status. The overall potential ecological risk for Pb and Cu in the region were mild, whereas Cd and Hg posed moderate to high risks, indicating that Cd and Hg were the dominant driving factors behind regional heavy metal pollution. The evaluation results of the information diffusion model based on the potential ecological risk indicated that the probability ranking of different levels of comprehensive potential ecological risk was as follows:slightly high (38.98%) > moderate (38.55%) > high (5.89%) > slight (5.15%) > extremely high (3.56%). The exceeding probabilities of potential ecological risk levels for Cd and Hg were significantly higher than those for Pb and Cu. The exceeding probability of different pollution levels of Hg were slight (94.89%), moderate (66.85%), slightly high (23.62%), high (3.9%), and extremely high (2%), of which only the surpassing probability of the slight level was lower than that of Cd. The prediction error of pollution probability of each potential ecological risk level was less than 5%, demonstrating the reliability of the information diffusion model based on the risk assessment. This research will provide technical reference and support for the monitoring and management of potential ecological risks from soil heavy metals in limited sample data regions.

PMID:38471886 | DOI:10.13227/j.hjkx.202304033

Huan Jing Ke Xue. 2024 Mar 8;45(3):1525-1538. doi: 10.13227/j.hjkx.202304087.

ABSTRACT

Shallow groundwater is the main source of water for living and industrial and agricultural production in Anqing City, which is an important basic guarantee to maintain the sustainable development of the social economy and regional ecological environment. In order to further study the water chemical characteristics and controlling factors of shallow groundwater in Anqing City, 196 groups of shallow groundwater samples were collected. A Piper diagram graph, Gibbs chart, ion ratio, and mathematical statistics were comprehensively used to study the water chemical characteristics and controlling factors of groundwater in Anqing City, and the contribution of different sources to the water chemical components of groundwater was quantitatively evaluated. The results showed that the shallow groundwater in Anqing City was weakly alkaline, with pH values ranging from 5.84 to 8.38, with an average value of 7.21. The TDS ranged from 47 to 1 620 mg·L^-1, with an average of 324.21 mg·L^-1. HCO₃^– and Ca²⁺ were the main anions, and the water chemical type was HCO₃-Ca type. The chemical components of groundwater were affected by rock weathering leaching, cation alternating adsorption, mineral dissolution and precipitation, and human activities. Ca²⁺, Mg²⁺, and HCO₃^– were mainly derived from the weathering dissolution of carbonate and silicate; Na⁺, Cl^–, and SO₄^2- were affected by industrial activities and domestic sewage discharge; and K⁺ and NO₃^– were affected by agricultural activities. The APCS-MLR receptor model analysis further revealed that the chemical components of groundwater were mainly geological factors, industrial factors, agricultural factors, and unknown sources, and their contribution rates were 45.35%, 14.19%, 25.38%, and 15.08%, respectively. Geological factors were important sources of hydrochemical components of shallow groundwater, and human activities aggravated the evolution of groundwater hydrochemistry.

PMID:38471867 | DOI:10.13227/j.hjkx.202304087