课程文献中心 更多>>

关键词： Human mobility   mobile phone data   machine learning   floating population  

摘要： Population mobility is a fundamental driver of urban development and socioeconomic processes, providing a critical foundation for scientific analysis and evidence-based decision-making. Despite its importance, most existing studies and applications continue to rely on static resident (de jure) population data, which fail to represent the spatiotemporal dynamics of human activity. In this study, we develop a comprehensive framework to map nationwide hourly floating (de facto) population across South Korea at 1 km spatial resolution for the period 2022-2024 by integrating mobile phone-based records with a machine-learning approach. The proposed framework incorporates a diverse set of spatial and temporal predictors, including building characteristics, land cover, accessibility indicators, temporal variables, and meteorological conditions, enabling the model to capture spatial heterogeneity and short-term temporal variability that are often neglected in prior population mapping studies. Quantitative evaluation demonstrates strong model performance, with leave-one-year-out cross-validation yielding high temporal generalization (Pearson correlation coefficients r = 0.981-0.993) and spatial cross-validation across unseen metropolitan regions indicating robust transferability (r = 0.847-0.941). Qualitative analyses reveal interpretable and realistic mobility patterns, including elevated nighttime populations in residential areas and pronounced daytime peaks in commercial and industrial zones, particularly around midday (13:00). The model also successfully captures city-specific mobility responses, holiday-related population redistribution, and weather-dependent behavioral changes, such as increased residential presence on rainy days. These results represent a substantial improvement over conventional static population datasets and existing floating population products. By resolving hourly variations in human presence at high spatial resolution, the resulting dataset provid

关键词： Synthetic Aperture Radar (SAR)   flood mapping   Google Earth Engine (GEE)   Multilayer Perceptron (MLP)   Deep Learning   graphical user interface (GUI)  

摘要： Rapid and accurate flood mapping and monitoring are essential for effective disaster management, response, and recovery, as well as for advancing hydrological sciences. Despite the increasing availability of geospatial data and cloud platforms like Google Earth Engine (GEE), existing GEE-based flood mapping applications largely depend on traditional thresholding techniques requiring manual input or struggle with latency due to loose-coupling of complex models. This study introduces DeepSAR Flood Mapper, a novel, fully automated deep learning-based flood mapping application on the GEE cloud platform as an operational, publicly accessible tool, providing interactive and near-real-time capabilities globally. DeepSAR Flood Mapper utilizes a pre-trained Multilayer Perceptron (MLP) deep learning model, selected for its computational efficiency and ability to model highly nonlinear functions, facilitating seamless integration with GEE. The model integrates two crucial input datasets: Sentinel-1 Synthetic Aperture Radar imagery (VV and VH polarization) for all-weather surface water detection, and Height Above the Nearest Drainage topographic data to mitigate commission errors in elevated areas and enhance reliability. Trained on a combination of global benchmark datasets and historical flood maps, the MLP model is deployed using an Offline Training and Online Prediction coupling strategy, which eliminates data transfer bottlenecks and allows for seamless, on-demand prediction within GEE. The application features an intuitive user interface that allows users to define an Area of Interest and target date, requiring no specialized knowledge. Performance evaluation demonstrates that DeepSAR Flood Mapper significantly improves flood mapping accuracy compared to traditional approaches, including Otsu's thresholding and classical machine learning models, Support Vector Machines and Random Forests. Its near-real-time capability supports timely and scalable flood monitoring across d

关键词： PD-1 blockade   gut microbiota   intestinal ischemia reperfusion injury   IL-10   gut barrier  

摘要： PD-1 blockade therapy is widely used in clinical practice. Intestinal ischemia reperfusion (IR) injury is a serious clinical complication that leads to remote organ damage through disruption of the gut barrier. However, the effects of PD-1 blockade on gut homeostasis and intestinal IR injury remain unclear. Here, we demonstrate that, in contrast to PD-1 deficiency, PD-1 blockade activates intestinal immunoglobulin A (IgA) responses in mice via a MyD88-dependent pathway. The increased production and bacteria-binding capacity of IgA induced by PD-1 blockade significantly reshape the gut microbial composition and metabolite profile. Furthermore, PD-1 blockade promotes intestinal mucosal CD4+ T cell IL-10 production. Notably, microbiota depletion by antibiotics attenuates intestinal IL-10 production, whereas transplantation of PD-1 blockade-altered microbiota facilitates IL-10 upregulation. These IL-10 enhancements appears to be driven by an increase in Lachnospiraceae_NK4A136_group, a recognized butyrate-producing bacterium, and elevated levels of microbiota-derived butyrate, which were increased after PD-1 blockade and significantly correlated with enhanced IL-10 production in the intestinal mucosa. The upregulation of intestinal IL-10 following PD-1 blockade suppresses inflammatory activation, thereby ameliorating the gut barrier impairment and remote organ injury induced by intestinal IR. In addition, we show that, in vivo and in vitro, butyrate supplementation enhances IL-10 expression in CD4+ T cells through PI3K gamma/phospho-mTOR signaling. Collectively, these findings indicate that PD-1 blockade promotes intestinal mucosal CD4+ T cell IL-10 production by modulating immune-microbiota interactions and subsequently mitigates intestinal IR-induced gut barrier dysfunction and organ damage.

关键词： Tryptophan   diabetes mellitus   GLP-1  

摘要： L-Tryptophan, an essential amino acid, precursor of serotonin, melatonin and niacin, has been implicated in glucose metabolism and gut hormone regulation. However, its role in diabetes remains obscure. This pilot study evaluated the effects of L-Tryptophan (Trp) supplementation on glycemic control, intestinal glucose absorption, biochemical markers and tissue histology in streptozotocin (STZ)-induced diabetic rats. Adult Wistar rats (n = 24) were divided into four groups: normal control, diabetic control, diabetic + Trp (50 mg/kg), and Trp control. Diabetes was induced by STZ (50 mg/kg). Trp was administered orally for 10 days. Blood glucose, serum biochemical parameters, intestinal glucose absorption, and Na+/K+-ATPase activity were assessed. Qualitative histological analysis of pancreatic and hepatic tissues was performed. Trp treatment in diabetic rats significantly reduced blood glucose and intestinal glucose absorption compared to diabetic controls. Pancreatic and intestinal Na+/K+-ATPase(NKA) remained statistically insignificant (p > 0.669 and 0.369). Improvements were observed in serum protein and cholesterol levels, pancreatic and hepatic histology as well as pancreatic GLP-1. L-Tryptophan demonstrated improved glycemia, metabolic benefits and tissue integrity in diabetic rats. These findings are preliminary and are interpreted within the limitations of a short duration. Further Mechanistic studies may elucidate Tryptophan-mediated mechanisms to evaluate its relevance in hyperglycemia.

关键词： italic>Arabidopsis thaliana   CASEIN KINASE 1   brassinosteroid   transcription   hypocotyl   root   growth  

摘要： The CASEIN KINASE 1 (CK1) family plays diverse roles in the development, physiology, and disease in eukaryotes. In Arabidopsis thaliana, the CASEIN KINASE 1-LIKE (CKL) family has 13 members, but to date, the roles of these kinases remain largely unclear. Here, we characterize several insertion mutants, finding that CKL12 may contribute to hypocotyl and primary root growth. Differential effects of insertions at various parts of the gene suggest that the 3 ' end of the transcript may be important for CKL12 function. We provide evidence that CKL12 may be a transcriptional target of brassinosteroid (BR) signaling. The CKL12 promoter contains in vitro binding sites for BR-related transcription factors. Knock-down of these transcription factors using RNA interference reduces CKL12 transcript. Together, these data suggest that CKL12 may act downstream of BR signaling to regulate seedling growth.

关键词： Sentinel-1 data   rapeseed mapping   phenological stages   radar scattering   polarization decomposition  

摘要： Accurate and timely rapeseed mapping is critical for assuring national food security and supporting agricultural regulation. Time series synthetic aperture radar (SAR) data is widely used to monitor the growth of rapeseeds and identify rapeseed distribution in cloudy and rainy regions. However, the spatial and temporal variations in plantation conditions keep presenting a challenge for SAR-based rapeseed mapping over large areas. Additionally, the temporal dynamic patterns and mechanism of SAR scattering could be investigated to enhance the mapping of rapeseed. Therefore, using time-series Sentinel-1 SAR data, this study proposed a general multi-phenology rapeseed index (MPRI) for automatic rapeseed mapping. Central to this method is establishing the linkage between time-series SAR backscattering (including intensity and polarimetric) patterns with rapeseed phenology. First, the rapid growth, flowering, and maturity stages of rapeseed were identified using a pseudo scattering-type parameter that was derived from polarimetric decomposition on Sentinel-1 SAR data. Second, the multi-phenology rapeseed index (MPRI) was developed by incorporating three stage-specific indices. Third, an optimal threshold was applied on the MPRI probability maps to generate binary masks of rapeseed distribution. The proposed MPRI approach is further evaluated by mapping rapeseed across three sites with varying planting conditions in China's Yangtze River Basin. Comparative experiments were conducted against with three available standard methods, including the RSG-OC, CARM, and SARM methods. Results show that the MPRI approach achieved the best performance for rapeseed mapping, with an overall accuracy and an F1 score above 0.90 at all three sites, which exceed these comparative methods by 0.02 similar to 0.10 in overall accuracy and 0.03 similar to 0.12 in the F1 score. Further discussion also reveals that by explicitly incorporating the temporal dynamics of microwave scattering throughout

关键词： PD-1   autoimmunity   agonist antibody   SHP2 recruitment   peripheral Th cells   immune balance   immune tolerance  

摘要： Precise inhibition of autoreactivity without concomitant induction of general immunosuppression is an overarching goal that remains elusive for the treatment of autoimmune diseases. PD-1 is preferentially expressed on activated T cells that drive autoimmunity. These PD-1+ T cells could serve as a target for therapeutic intervention. Here, we report the discovery of a unique PD-1 agonist antibody, GenSci120, that exhibited potent and selective T-cell inhibition in vitro and T-cell depletion activity both in vitro and in vivo. Target engagement by GenSci120 directly promoted SHP2 recruitment into the PD-1 signaling pathway but also enhanced the binding of PD-1 to its natural ligands and augmented PD-L1-induced PD-1 signaling. Moreover, GenSci120 exhibited robust efficacy in several animal models of human autoimmune disease. Thus, GenSci120, by selectively depleting PD-1+ T cells and by directly (via PD-1 binding and SHP2 recruitment) or indirectly (via enhancing PD-1 and ligand interaction) stimulating PD-1 signaling, has the capability to restore immune balance in autoimmunity. In a first-in-human study in healthy adults (NCT06827457), GenSci120 demonstrated favorable safety/tolerability and pharmacokinetic profiles as well as robust pharmacodynamic effect. Together, these findings suggest the potential of GenSci120 as an innovative precision medicine for treating autoimmune diseases and support further evaluation of this investigational new drug in future clinical trials.

关键词： Allergen immunotherapy   allergic   PLGA   mites   rhinitis  

摘要： Subcutaneous immunotherapy has several limitations, including the long dose escalation period, frequent injections and risk of adverse reactions. Crude extracts used for immunotherapy can contain unrecognized immunostimulatory components or induce neosensitization. Therefore, in this study, we aimed to develop a new efficient method to induce allergen-specific immune tolerance using Dermatophagoides pteronyssinus (Der p) 1-containing nanoparticles. We developed two different types of allergen-containing poly(lactic-co-glycolic) [PLGA] nanoparticle vaccines: Der p 1-encapsulated and Der p 1-conjugated vaccines. House dust mite (HDM)-sensitized mice were administered positive control (PC), PLGA (vehicle control), encapsulated vaccine (EV), and conjugated vaccine (CV) via intravenous injections one week after sensitization. Subcutaneous immunotherapy group received three subcutaneous HDM extract injections at two-day intervals. After challenge, we compared the rhinitis symptoms, immunoglobulin (Ig) levels, and histopathology of the nasal mucosa and analyzed splenocyte cultures for cytokine production and regulatory T cell activation. EV and CV groups exhibited improved nasal symptoms and lower ear swelling and inflammation in the nasopharyngeal lavage and nasal tissues than PC group. Serum HDM-specific IgG1 levels were higher in EV and CV groups than in PC group. No changes were observed in the total and HDM-specific IgE levels in EV group. EV group exhibited lower interleukin-4, -5, -13, and -17 levels and higher interleukin-10 and interferon-gamma levels than PC group. The two vaccinated groups exhibited significantly higher regulatory T cell activation than PC group. Overall, intravenously administered Der p 1-containing nanoparticles alleviated the allergic responses and induced tolerance in a murine allergic rhinitis model.

关键词： Land surface phenology   MODIS-like NDVI   spatiotemporal data fusion   global vegetation dynamics   remote sensing  

摘要： As climate change continues to reshape global ecosystems, accurately monitoring and understanding shifts in land surface phenology (LSP) has become increasingly critical for detecting vegetation responses, assessing ecosystem resilience, and improving predictions of climate-biosphere interactions. While several moderate-to-fine spatial resolution global LSP datasets exist, most are constrained to post-2000 records due to the availability of MODIS era observations, leaving a significant gap in long-term phenological information and limiting our ability to investigate multi decadal trends. To address this, we developed the first global 1 km resolution LSP dataset spanning 1982-2018. By integrating MODIS and AVHRR NDVI data through the enhanced Flexible Spatiotemporal Data Fusion (cuFSDAF) model, we reconstructed pre-2000 MODIS-like NDVI time series with improved temporal consistency and reduced cross sensor bias. Using logistic functions and third-order derivatives, we extracted four key phenological metrics, including the start of the growing season (SOS), maturity, senescence, and the end of the growing season (EOS), enabling detailed characterization of vegetation development stages across diverse biomes. In the Northern Hemisphere (NH), SOS, maturity, and EOS advanced significantly from 1982 to 2018, while senescence was delayed, indicating a widespread lengthening of the growing season. In contrast, the Southern Hemisphere (SH) experienced delayed SOS, maturity, and senescence, with EOS occurring earlier, suggesting a shortening of the growing season and revealing contrasting hemispheric sensitivities to climate forcing. These metrics were validated against ground-based observations from multiple networks, demonstrating strong consistency, high accuracy, and reliable reconstruction of long term phenological signals. As the first dataset of its kind at 1 km resolution over such an extended period, it provides an invaluable resource for studying global vegetation d

关键词： Type 1 diabetes   diet   microbiome   probiotics   gluten   breastmilk   fecal microbiome transplant  

摘要： The incidence of type 1 diabetes (T1D) has risen sharply in recent decades, implicating the role of environmental factors in disease pathogenesis. Diet, a primary driver of gut microbiome development and composition, along with other environmental exposures, has emerged as a potential modulator of T1D risk and progression. While nutrients, such as certain vitamins, may exert protective effects, the roles of other dietary factors (e.g., early exposure to dietary antigens) remain unclear. Importantly, diet shapes the gut microbiome, which produces immunomodulatory metabolites, including secondary bile acids, short-chain fatty acids (SCFAs), and others that directly influence immune responses. This review presents evidence on how specific dietary factors, including macronutrients (fats, carbohydrates, proteins, such as gluten and milk proteins), fibers, and breastfeeding, affect the gut microbiome and T1D. We also discuss the effects of microbiome-targeted interventions, including probiotics, prebiotics, and fecal microbiota transplantation, on T1D and their potential as future therapeutic strategies. Although animal studies provide compelling mechanistic insights, the results from human trials remain inconsistent, underscoring the urgent need for longitudinal and interventional studies to establish causality. Understanding the complex interplay between diet, the gut microbiome, and immune homeostasis is essential for developing personalized strategies to prevent and treat T1D and delay-related complications.