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Lateral movement of soil organic carbon (SOC) induced by soil erosion and runoff changes spatial distributions of SOC, and further changes the land‐atmosphere CO2 exchange and terrestrial carbon budget. However, current ecosystem models do not or only poorly integrate the process of SOC lateral movement and cannot simulate the impacts of soil erosion on the carbon cycle. This study integrated SOC erosion and deposition processes into a process‐based ecosystem model (i.e., Integrated BIosphere Simulator (IBIS)), and separately simulated the lateral movements of dissolved organic carbon (DOC) and particulate organic carbon (POC). The model was evaluated in three river basins in Northeast China that are dominated by cropland, forest, and grassland. The results showed that the model reproduced well the production, erosion, and deposition of DOC and POC. The annual SOC lateral movement (1.34–7.22 g C m−2 yr−1) induced by erosion in the three tested basins was 0.27%–1.45% of the annual net primary production. The model developed in this study has great implications for simulating the lateral movements of SOC in terrestrial ecosystems, which can improve model performance in projecting the terrestrial carbon budget. Plain Language Summary: Lateral movement of soil organic carbon (SOC) with soil erosion and runoff is an important process in estimating land carbon budget. However, the current ecosystem models are not or poorly integrated this process, and cannot simulate the impacts of lateral movement of SOC on carbon cycle. This study integrates SOC erosion and deposition processes into a process‐based ecosystem model (Integrated BIosphere Simulator (IBIS)), and separately simulates the lateral movements of dissolved organic carbon (DOC) and particulate organic carbon (POC). The model was evaluated at three river basins in Northeast China dominated by cropland, forest and grassland, respectively. The results showed the model can reproduce well the production, erosion, deposition of DOC and POC. The model developed in this study has great implications for simulating the lateral movements of SOC in terrestrial ecosystem, which can improve model performance on projecting terrestrial carbon budget. Key Points: Current ecosystem models inadequately depict the lateral movement of SOC, causing uncertainties in terrestrial carbon cycle modelingWe integrated SOC erosion and deposition into a process‐based ecosystem model and evaluated it in three Chinese river basinsModel simulations well represented observed data for the production, erosion, and deposition of organic carbon [ABSTRACT FROM AUTHOR]

It is crucial to investigate the characteristics of meteorological drought in the Beijing–Tianjin–Hebei (BTH) region to improve the accuracy of agriculture and water resource monitoring and management. In this study, using instrumental observation data from 85 meteorological stations in the BTH region during 1961–2023 derived from the National Meteorological Information Center, we first calculated the meteorological drought comprehensive index (MCI) and analyzed the spatiotemporal characteristics of the MCI. In the BTH region, the MCI intensity from May to June was the most severe in the intraseasonal variation. The trend of the decreasing drought intensity in May–June has occurred for the past 60 years. The southern region in the BTH region was more likely to experience droughts. Next, the spatial patterns of the top two EOF modes of the May–June MCI were depicted. The primary spatial pattern of the BTH, which was characterized by consistent changes in the MCI throughout the entire BTH region, could be represented by the first mode's R2 of 69.01%. Then, we compared the spatial pattern of the MCI intensity under different return periods. Using the May–June MCI of 1961–2023, the drought intensity gradually increased from northwest to southeast for the 10-, 20-, and 50-year return periods. However, the drought intensity decreased and then increased from northwest to southeast based on the 1991–2023 MCI. Notably, a 20-year return period of severe drought affected Beijing and northern Hebei in 2023. Finally, we discussed the linkages of drought in the BTH region and atmospheric circulation/sea surface temperature (SST) anomalies, which were calculated using the Pearson correlation coefficient and wavelet coherence. We suggest that the MCI variations in the BTH region may be related to the SST anomalies of the Indian Ocean in 1961–1990 and the Pacific Ocean in 1991–2023, respectively. The abovementioned studies have enlightened us to focus on predicting the Pacific SST for drought, which will facilitate agricultural production and water resource management in the BTH region. [ABSTRACT FROM AUTHOR]

Hydroclimate variations over eastern China are affected by the Asian monsoon, exhibiting great variability and frequent extreme events occurrence. However, the driving mechanisms of their spatial and temporal variabilities are not fully understood due to the short period of available climate observation data. Here we used interpolated dry/wet grades dataset derived from Chinese historical documents and method of regional division to reconstruct a new annual hydroclimatic variation dataset dating back 1000 years, including nine regions of eastern China. This dataset reveals the spatial coverage and trend of long‐lasting extreme drought and flood events, and discloses the spatial patterns and similarities of interannual (2–7‐year) and interdecadal (15–35‐year) hydroclimate variations under the different temperature backgrounds of the Medieval Climate Anomaly (MCA), Little Ice Age (LIA) and Current Warm Period. Although no obvious drying or wetting trends were detected in the past 1000 years, the frequencies of extreme flood and drought events during the two warm periods of 960–1300 and 1901–2000 were higher than those during the cold period of 1301–1900. There are 17 long‐lasting and even severe than 1637–1641 large spatial scale extreme drought events during the past 1000 years. The observed spatial dipole pattern of flooding in the south and drought in the north, or the opposite pattern, was rare during the historical period. However, it was the second leading mode explaining the low variances in the principal component analysis for 2–7‐year hydroclimatic variations, which were not related to temperature change. Moreover, the stability of the teleconnection between the hydroclimate over eastern China and the climatic modes of Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation was further discussed. [ABSTRACT FROM AUTHOR]

Purpose: Anatomical and molecular staging strategies are needed for the personalized treatment of localized pancreatic ductal adenocarcinoma (PDAC). This study evaluated the performance of [68 Ga]Ga–FAPI-04 and [18F]F-FDG PET/CT on the disease staging and prognostic value of patients with localized PDAC on contrast-enhanced (CE)-CT images. Methods: Patients with suspected localized PDAC on CE-CT were recruited for static [68 Ga]Ga-FAPI-04 and 18[F]F-FDG and PET/CT, and select patients underwent simultaneous 60-min dynamic 68 Ga-FAPI-04 PET/CT. The diagnostic and staging performances of the static PET/CT results were evaluated by delineating regions of interest in the primary tumor, whole pancreas, and distal pancreas in both types of scans and then evaluating correlations between the PET/CT findings and clinicopathological characteristics. Furthermore, Kaplan–Meier and hazard ratio (log-rank) methods were used to evaluate the prognostic value of the combined dynamic [68 Ga]Ga-FAPI-04 and static [18F]F-FDG PET/CT method. Results: We included 49 patients with histologically confirmed PDAC adenocarcinomas; 32 underwent 60-min dynamic [68 Ga]Ga-FAPI-04 PET/CT imaging simultaneously. The static [68 Ga]Ga-FAPI-04 method had significantly higher accuracy and uptake values than the static [18F]F-FDG method for primary PDAC lesions, metastatic lymph nodes, and distal metastases. Furthermore, 18.4% and 10.2% of the patients' stages changed after using the [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT methodologies, respectively, compared to the CE-CT-designated stage. The Ki values obtained from dynamic [68 Ga]Ga-FAPI-04 PET/CT did not differ between PDAC and distal obstructive pancreatitis lesions. Pathologically enlarged tumor size, poor differentiation, and perineural invasion were associated with increased [68 Ga]Ga-FAPI-04 uptake but not with [18F]F-FDG uptake. The preoperative prognostic performance of [68 Ga]Ga-FAPI-04 was better than that of [18F]F-FDG. Interestingly, combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG uptake results in the whole pancreas could further stratify patients based on their postoperative prognosis. Conclusion: 6[68 Ga]Ga-FAPI-04 PET/CT was more sensitive and accurate than [18F]F-FDG PET/CT for tumor, node, and metastasis staging of PDAC identified on CE-CT. Additionally, [68 Ga]Ga-FAPI-04 uptake was significantly associated with pathologically aggressive tumor features. Combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT findings improved the prognostic value, potentially providing a non-invasive guide for clinical management. Finally, increased fibroblast activity in PDAC-induced obstructive pancreatitis may be associated with poor patient survival rates. [ABSTRACT FROM AUTHOR]

Purpose: Our aim was to assess the prognostic value of [68 Ga]Ga-FAPI-04 positron emission tomography (PET) uptake in PDAC and to evaluate the correlation between in vivo lesional radioactivity with pathological characteristics of pancreatic ductal adenocarcinoma (PDAC). Methods: We retrospectively analyzed treatment‐naïve PDAC patients who underwent preoperative [68 Ga]Ga-FAPI-04 PET/CT followed by pancreatectomy. The tracer uptake was determined as maximum tumor standardized uptake value (SUVmax), FAPI-avid tumor volume (FTV), total lesion FAP expression (TLF) as well total pancreatic uptake (TSUVmax), total FAPI-avid pancreatic volume (FPV), and total pancreatic FAP expression (TPF). Spearman's correlation analysis was performed to evaluate the association between [68 Ga]Ga-FAPI-04 PET/CT imaging and ex vivo immunohistological FAP expression and pathological characteristics of surgical specimens (differentiation, size, vascularity, perineural invasion, and lymph node metastases). Kaplan–Meier and hazard ratio (HR, log-rank) methods were used to evaluate the prognostic value of [68 Ga]Ga-FAPI-04 PET/CT and clinicopathological factors. Results: Thirty-seven surgical PDAC patients were included. The ex vivo expression of FAP was significantly associated with the tumor SUVmax and TLF. FAP expression was more abundant in poorly differentiated PDAC than in well- to moderately differentiated neoplasms. Tumor SUVmax or TLF and pancreatic TSUVmax or TPF were significantly correlated with tumor size, differentiation, and perineural invasion, respectively. SUVmax had a significant independent prognostic value for recurrence-free survival (HR = 2.46, P < 0.05), while [68 Ga]Ga-FAPI-04 TPF predicted overall survival (HR = 12.82, P < 0.05). Conclusion: The in vivo [68 Ga]Ga-FAPI-04 uptake in localized PDAC showed a significant correlation with ex vivo FAP expression and aggressive pathological characteristics. [68 Ga]Ga-FAPI-04 PET/CT also presented a potential for postoperative prognostication of PDAC. Elevated fibroblast activity induced by obstructive pancreatitis might be associated with the patient's survival. [ABSTRACT FROM AUTHOR]

Proxy-based precipitation reconstruction is essential to study the inter-annual to decadal variability and underlying mechanisms beyond the instrumental period that is critically needed for climate modeling, prediction and attribution. Based on 2912 annually resolved proxy series mainly derived from tree rings and historical documents, we present a set of standard precipitation index (SPI) reconstructions for each year (November–October), covering the whole of Asia, and for the wet season (i.e., November–April for western Asia and May–October for the others) since 1700, with the spatial resolution of 2.5 ∘. To screen the optimal candidate proxies for SPI reconstruction in each grid from available proxies in its connected region with a homogeneous rainfall regime and similar precipitation variability, a new approach is developed by adopting the grid-location-dependent division derived from the instrumental SPI data. The validation shows that these reconstructions are effective for most of Asia. The assessment of data quality compared with gauge precipitation before calibration time indicates that our reconstruction has high quality to show the precipitation variability in most of the study areas, except for a few grids in western Russia, the coastal area of southeast Asia and northern Japan. The full dataset can be obtained from https://doi.org/10.57760/sciencedb.01829 (Y. Liu et al., 2022). [ABSTRACT FROM AUTHOR]

The major droughts and floods in the Hanjiang River Basin, central China, have a significant impact on flood prevention and control in the middle reaches of the Yangtze River and water resources management in the areas of the South–North Water Diversion Middle Line Project. However, there is a lack of understanding of the multi-decadal to centennial-scale patterns of extreme droughts and floods in the area. Applying the yearly drought and flood records from historical documents and precipitation data in the period of instrumental measurements, this study constructs a time series of extreme droughts and floods in the Hanjiang River Basin from 1426–2017 and analyzes the temporal and spatial characteristics of the extreme drought and flood event variations. The results show that there were a total of 45 extreme droughts and 52 extreme floods in the basin over the past 592 years. Extreme droughts and floods were highly variable on a multi-decadal to centennial scale, and the frequencies were higher in the first and last 100 years or so of the study period and lower in between. Spatially, the frequencies of extreme droughts and floods were generally higher in the middle and lower reaches than in the upper reaches. It was also found that there is a good correlation of drought and flood frequencies between the upper Hanjiang River Basin and North China. These results are informative for the study of mechanisms and predictability of multi-decadal to centennial-scale variability of extreme hydroclimatic events in the river basin. [ABSTRACT FROM AUTHOR]