This study aimed to clarify whether interleukin-1 receptor antagonist (IL-1RA) mediates the age-dependent immunomodulatory capacity of adipose-derived stem cells (ASCs) via regulating macrophage polarization. ASCs from young (Y-ASCs) and aged (O-ASCs) C57BL/6 mice were isolated. IL-1RA, which was identified as an age-sensitive candidate through integrated transcriptomic and proteomic screening in our prior publication, was validated by qPCR, immunofluorescence, and ELISA. RAW264.7 macrophages were polarized and co-cultured with ASCs or treated with recombinant IL-1RA; IL-1RA in Y-ASCs was silenced by siRNA (82.3 ± 5.1% knockdown efficiency). The results showed Y-ASCs had 2.1-fold higher IL-1RA mRNA and significantly higher protein secretion than O-ASCs (p < 0.001). Y-ASC transplantation enhanced M2 polarization (CD206+ cells increased from 9.36% to 21.4% in vivo; p < 0.01) in aged mouse adipose tissue and reduced inflammation (serum IL-1β lowered by 42.3 ± 5.1%; p < 0.001), while O-ASCs had no effect. Recombinant IL-1RA recapitulated Y-ASC effects (M2 macrophages increased from 0.92% to 61.8%; p < 0.001), and IL-1RA silencing abrogated Y-ASC function. The data indicate IL-1RA is a key age-sensitive mediator of ASC immunomodulation. Declined IL-1RA may contribute to impaired aged ASC efficacy, highlighting donor age’s importance. This provides mechanistic insights and guides IL-1RA-targeted optimization for ASC therapies in age-related inflammatory disorders.

Ecological ground-based monitoring is essential for understanding the interactions between biodiversity and carbon sequestration, providing insights to address biodiversity loss and improve forest quality. This study aimed to explore the synergies and driving mechanisms of carbon sequestration and biodiversity in subtropical naturally regenerating and planted forests of different ages or successional stages. Based on 326 forest ecosystem plots, we quantified the spatial-temporal heterogeneity of tree species biodiversity and biomass, as well as the driving effects of environmental factors and stand structure, using Mantel test, multiple linear regression model, partial least squares path modeling (PLS-PM), and Hot-spot analysis. Our findings revealed that species richness in subtropical forests of Hunan ranged from 5.04 to 5.71. Mantel test indicated that stand structure and environmental factors influenced biodiversity by enhancing environmental heterogeneity and niche differentiation. The planted forests (93.41 ± 3.87 Mg·ha-1) exhibited higher biomass than naturally regenerating forests (88.21 ± 4.60 Mg·ha-1), but were more directly influenced by environmental factors due to reduced environmental adaptation. PLS-PM results revealed that in naturally regenerating forests, species diversity (standardized path coefficient: 0.19, p< 0.05) and functional diversity (0.24, p< 0.05) combined with soil (0.43, p< 0.001) promoted biomass accumulation. This study explored how niche theory and complementarity effects drove biomass accumulation in naturally regenerating forests by enhancing environmental adaptation. Hot-spot analysis advocated the need for forest management to prioritize naturally regenerating forests, ensuring the sustainability of biodiversity and ecosystem functions. Our study emphasized the adoption of a dual strategy of optimizing planted forests structure and protecting naturally regenerating forests to enhance subtropical forest ecosystems’ role in addressing global change and regional sustainability.

After mastering the key technologies of manufacturing spaceborne Synthetic Aperture Radar (SAR), China’s SAR satellites have been successfully launched into space. As the only civil microwave satellite listed in the “National High-resolution Earth Observation System Major Project,” the Gaofen-3 (GF-3) 01 satellite is the first C-band multi-polarization SAR satellite with a resolution of 1 m. GF-3 series satellites stand out among civil SAR satellites worldwide because of their high resolution, wide swath, high geometric radiation quality, multiple imaging modes, and long operation time. Taking GF-3 series satellites as an example, this study introduces the development of China’s civil SAR satellites, as well as their processing strategies and applications. The success of the GF-3 series satellites shows that China’s SAR remote sensing technology has stepped into a new era of high-quality and high-precision Earth observations.

Adipose-derived stem cells (ASCs), as a cell therapy with considerable therapeutic potential, have received increasing attention in tissue repair, endocrine regulation, immune regulation, and aging and obesity research. Gut microbiota are present in all organisms and play important roles in the development of aging and obesity. Dysbiosis activates inflammatory pathways that may contribute to the development of aging and obesity. We used C57BL/6J mice of different ages to carry out the experiment. Young mice were used as donors for ASC. Feces from the three groups were collected for 16sRNA sequencing to analyze the species composition of intestinal microorganisms. Then, predicted metabolic pathways by PICRUSt2 using 16s rRNA gene sequences. Immune cell levels in abdominal adipose tissue was assessed by flow cytometry. The content of IL-6、TNF-α and LPS in serum was measured by ELISA kit. Our 16sRNA sequencing data showed restoration of gut microbiota diversity and an increase in beneficial flora (Akkermansia, Lactobacillus, Prevotella) 7 days after ASC transplantation. In addition, the inflammatory environment improved in older transplanted mice.

Background Adipose-derived stem cells (ASCs) have anti-aging and anti-obesity effects in aged animals, but the underlying molecular mechanism remains unknown. Methods In the present study, we evaluated the in vivo transplantation effects of different age donor-matched ASCs on natural aging and leptin knockout mice (ob − /ob − mice). The multi-omics expression profiles of young and aged mouse donor-derived ASCs were also analyzed. Results The results revealed that ASCs from young donors induced weight and abdominal fat loss for older recipients but not for young or ob − /ob − mice. The young and aged mouse donor ASCs displayed significant phenotypic differences, contributing to the distinguished weight loss and anti-aging effects in aged mice. Conclusions Our data suggest an underlying molecular mechanism by which young-donor ASCs reduce immune cells and inflammation in aged mice via secreted immune factors. These findings point to a general anti-aging mechanism of stem cells, which may provide new insights into age-related disturbances of stem cell plasticity in healthy aging and age-related diseases.

GaoFen-3 (GF-3) is a C-band multipolarization synthetic aperture radar (SAR) satellite with 12 imaging modes. However, its initial positioning accuracy remains unsatisfactory, thereby hindering its use for large-area surveying and mapping. This study proposes a block orthorectification method without ground control points (GCPs) using the GF-3 Fine strip II (FSII) mode. To address the challenges with the accuracy and efficiency of this method, an integrated block orthorectification method was developed to conduct integrated processing of large-scale GF-3 satellite images without GCPs. Geometric calibration was used to improve the absolute positioning accuracy of each SAR image. Then, several tie points (TPs) were extracted using the SAR scale-invariant feature transform (SIFT) operator. A parallel matching strategy was used in the block images registration. The block adjustment model was constructed to solve the orientation parameter of all SAR images. The experimental results of 1,468 GF-3 images of China’s entire land area show a TPs root-mean-square error of 0.724 pixel and 8.014 m for the independent checkpoint, suggesting that the proposed method can effectively improve the geometric accuracy of GF-3 satellite images and demonstrate the feasibility of large-scale SAR mapping without GCPs.

The environment of healthcare institutes (HCIs) potentially affects the internal microecology of medical workers, which is reflected not only in the well-studied gut microbiome but also in the more susceptible oral microbiome. We conducted a prospective cross-sectional cohort study in four hospital departments in Central China. Oropharyngeal swabs from 65 healthcare workers were collected and analyzed using 16S rRNA gene amplicon sequencing. The oral microbiome of healthcare workers exhibited prominent deviations in diversity, microbial structure, and predicted function. The coronary care unit (CCU) samples exhibited robust features and stability, with significantly higher abundances of genera such as Haemophilus , Fusobacterium , and Streptococcus , and a lower abundance of Prevotella . Functional prediction analysis showed that vitamin, nucleotide, and amino acid metabolisms were significantly different among the four departments. The CCU group was at a potential risk of developing periodontal disease owing to the increased abundance of F. nucleatum. Additionally, oral microbial diversification of healthcare workers was related to seniority. We described the oral microbiome profile of healthcare workers in different clinical scenarios and demonstrated that community diversity, structure, and potential functions differed markedly among departments. Intense modulation of the oral microbiome of healthcare workers occurs because of their original departments, especially in the CCU.

Purpose Our previous study found that white adipose stem cells (W-ASCs) derived from abdominal and femoral sulcus white adipose stem cells (ASCs) have antiaging and age-related obesity effects. Whether interscapular brown adipose stem cells (B-ASCs) have the same effect has not been reported. The study objective was to compare the effects of ASCs from different tissues on aging and aging-related obesity. Patients and Methods C57BL/6J mice at 22 months of age were transplanted with either B-ASCs or W-ASCs from young mice at 2 months of age. Changes in body weight, biochemistry, cytokines, hormone secretion, cell senescence, lipid metabolism, and ASC function were assessed after transplanted 1 month. Results W-ASCs were superior to B-ASCs as aging and age-related obesity indicators, based on change in body weight, organ weight, antioxidant and anti-inflammatory activity, lipid metabolism, and liver and kidney function. Conclusion Difference in the tissue source was reflected by the heterogeneity of antiaging and age-related obesity effects of transplanted ASCs. Based on the study results, we recommend W-ASCs over B-ASCs in aging and age-related obesity applications.

1School of Life Sciences, Guangxi Normal University, Guilin, Guangxi Zhuang Autonomous Region, People’s Republic of China; 2Guangxi Universities Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guilin, Guangxi Zhuang Autonomous Region, People’s Republic of China; 3Research Center for Biomedical Sciences, Guangxi Normal University, Guilin, Guangxi Zhuang Autonomous Region, People’s Republic of China

Spaceborne bistatic synthetic aperture radar (BiSAR) with a geosynchronous (GEO) transmitter and a low-earth-orbit (LEO) receiver can offer high signal-to-noise ratio, fine resolution and large surveillance area, which provides great potential for future Earth observation technology. Nevertheless, due to complex bistatic geometry and big differences of orbital characteristics, the configuration design of GEO-LEO BiSAR remains a challenge. To address the issue, mathematic models between the indicators related to the imaging performance and the configuration parameters are firstly derived based on the geometry analysis. Then, a general nonlinear multivariate objective function is presented for the desired imaging performance. Accordingly, the configuration design problem can be transformed to solve nonlinear multivariate optimisation equation. A novel optimal configuration design method based on the simulated annealing algorithm is presented. Finally, simulation results are provided for two typical observational missions to verify the effectiveness of the proposed method.

This study proposes a sparse linear array synthetic aperture radar (LASAR) on a spaceborne dual platform. The transmitting elements are placed at the LASAR tips that form a satellite's dual platform, and the receiving elements are placed on the large deformation composite pine which is between the satellite's dual platform. Based on the principle of phase centre of approximation and multiple input multiple output, LASAR with the sparse array could obtain a high-resolution imaging in the cross-along direction, which is crucial to a three-dimensional SAR system. Furthermore, the LASAR system has different modes, such as interferometry and ground moving target indication.

Inspired by recent advances in frequency diverse array (FDA) and multiple-input-multiple-output (MIMO) radars, this paper investigates the target detection performance of FDA-MIMO radar, which jointly utilizes the advantages of FDA radar and MIMO radar, for single- and multiple- coherent pulses, respectively. Firstly, the signal models in target detection are formulated for FDA-MIMO, standard FDA, phased-array and MIMO radars, respectively. We present a unified framework detector to comparatively analyze their target detection performance in the Neyman-Pearson sense. Furthermore, the deflection coefficient and signal-to-interference-plus-noise ratio (SINR) are also adopted as a performance metric to compare their performance. Numerical results show that FDA-MIMO radar achieves better target detection performance as compared to other conventional radar systems, specially when multiple coherent pulses are utilized.

In this paper, a deception jamming method based on frequency diverse array (FDA) antenna of uniform linear array is proposed to generate false point target in the range direction. And because the FDA produces tiny frequency offsets on the array elements, the transmit beam has angles-, ranges-, and even time-dependent. This provides a potential for new SAR imaging jamming techniques. This paper discusses a novel SAR imaging multi-target deception jamming method. Moreover, the location and number of false targets can be manipulated arbitrarily. We have made a modification to the CS factor to adapt to the deception jamming model using FDA antenna. The simulation results of point target verify the correctness of the theory.

The bistatic synthetic aperture radar (SAR) system, based on an inclined geosynchronous earth orbit (GEO) illuminator and a low-earth-orbit (LEO) receiver, has the advantages of high spatial and temporal resolution, higher signal-to-noise ratio (SNR) and good concealment. In this paper, the new system of bistatic InSAR with one GEO transmitter and two LEO receivers is studied. Firstly, we employ Hill equation to design the formation configuration between two LEO SAR receiving platforms. The vertical baseline can be formed between receivers, yielding GEO-LEO bistatic interferometric SAR (InSAR) system. Secondly, under bistatic InSAR interferometric geometry, the positioning equations of InSAR are established, and the elevation measurement accuracy and plane measurement accuracy are analyzed. The simulation results show that the GEO-LEO bistatic InSAR system has good interference performance and can achieve the meter-level interferometric measurement accuracy.

The bistatic interferometric synthetic aperture radar (InSAR) system, with a geosynchronous earth orbit (GEO) illuminator and two low-earth-orbit (LEO) receivers, has the advantages of flexibility, lightweight receiving platform and low cost. However, its geometry of bistatic interferometry is complex, and its slant range equation is in the form of round-trip delay. The traditional three-dimensional (3D) positioning methods of InSAR with ‘one-transmitter and two-receivers' and repeat tracks are invalid. In order to solve this problem, firstly, we establish the bistatic InSAR target positioning equations. Secondly, according to the interferometric geometry, the conversion relationship between baseline vector and slant range vector is constructed. Then, we derive and present a closed-form solution of the bistatic InSAR target positioning in the form of geostationary GEO SAR orbit. Finally, the effectiveness of the proposed method is verified by simulation data.

Spaceborne bistatic multichannel synthetic aperture radar (MC-SAR) system employed inclined geosynchronous Earth orbit (GEO) transmitter and low-Earth-orbit (LEO) receiver can provide fine spatial resolution and a vast area of surveillance, which presents great potentials for future Earth observation. Nevertheless, owing to special geometry and big differences of orbital characteristics, the conventional effective phase centre (EPC) operation for unambiguous SAR signal reconstruction cannot be directly used. To address the issue, starting from geometry model of GEO-LEO bistatic MC-SAR, the new effective positions of the receiving channels are obtained. Then, the time-variant characteristics of residual phase error after the presented EPC processing is analysed. Finally, the method of reconstructing unambiguous SAR signal is presented. Simulation results show the validity of the proposed method, which can efficiently reconstruct the unambiguous signal for GEO-LEO bistatic SAR.

In this paper, the study on the digital elevation model (DEM) reconstruction using Gaofen-3 satellite repeat-pass synthetic aperture radar (SAR) interferometry is presented. The coherence of the single-look complex (SLC) images and residuals of interferogram provide a powerful guarantee for interferometric processing for Gaofen-3. Baseline estimation is the key factor to generate accurate DEM with SAR interferometry. This paper uses the coarse orbit data and the precise orbit data of Gaofen-3 to carry on the baseline estimation and uses the prior coarse DEM information to refine the baseline estimation. Then, the topographic height is reconstructed with more precise spatial baseline. An experiment is conducted to verify the conclusion, and some mountain and flatten region are chosen as the study area. The results show that the DEM errors based on the prior DEM method are rapidly converged compared with the ones based on the orbit data method. Therefore, benefiting from the precise orbit data of the Gaofen-3 satellite, the accuracy of the baseline estimation can be improved further by using the method based on prior DEM information; thus, higher accuracy of DEM can be achieved so that Gaofen-3 repeat-pass data have some good characteristics, such as high imaging quality, stable spatial baseline, and high correlation, which has a good repeat-pass SAR interferometry application prospect.

Large-scale microwave remote sensing research requires multiple synthetic aperture radar (SAR) image mosaics. However, owing to multiple factors, different SAR images frequently exhibit intensity differences. This leads to poor intensity continuity after mosaicking, making SAR image interpretation extremely difficult. The existing method assumes that SAR images have been subject to strict radiometric calibration and mainly focuses on intensity balancing to minimize the intensity difference between adjacent images. This method is not effective when the intensity difference between SAR images is large. In this paper, a novel random cross-observation intensity consistency (RCOIC) algorithm is proposed to eliminate the intensity differences for SAR image mosaics. The proposed algorithm is based on global intensity constraints. First, source images are downsampled. Then, the gain correction coefficients of each image in a study area are accurately estimated through random cross-observation. Further, multi-view local intensity correction of each image in the study area is performed using the overlapping areas of adjacent images, and a low-resolution intensity reference map covering the study area is generated. Finally, the intensities of high-resolution source images are corrected by constructing local independent linear models of images based on the low-resolution intensity reference map. Gaofen-3 satellite images with large ranges and large time differences, covering most of China's land area, were selected to test the effect of the newly developed algorithm. After processing, the overall visual effect was good after mosaicking, the intensity transitions at the edges of the images were smooth, the intensity distributions corresponded better to actual ground objects, and the statistical result of adjacent images overlapping regions was good. This validates the reliability of the algorithm.

This paper presents a water body detection framework with an automatic threshold determination procedure. Water bodies in SAR image often appear dark and homogeneous due to specular reflection. Therefore, the water bodies can easily be detected with a thresholding method. However, the threshold needs to be adjusted interactively for every SAR data due to backscatter differences between water bodies in SAR data. The recursive Otsu thresholding method is used to determine the threshold automatically. The normalized between-class variance is introduced to select optimal threshold from threshold set generated by the recursive Otsu thresholding. The presented framework eliminates the manual operating interaction and has a near-real-time capability in extracting water bodies from huge amounts of data. Experimental results with TerraSAR-X stripmap data verify the effectiveness of the framework.

A large aperture membrane phased array antenna with an array antenna and transmit/receive (T/R) modules is presented for geosynchronous Earth orbit synthetic aperture radar applications. Its scanning beams can cover ±8° with ignorable grating lobes within its visible area. By utilising the coplanar reintegration technique of multichips, compact and light-weight T/R modules can be achieved. A scaled model is demonstrated and characterised experimentally. Measured results validate the feasibility and efficiency of the design method for the membrane phased array antenna.