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The Yangtze River Economic Belt is an important grain production area and ecological reserve in China. It is of great practical significance to promote coordinated development between grain production and agricultural ecological protection in this region. This paper analyzed the coupling and coordination of grain production and agricultural ecological protection in the Yangtze River Economic Belt during 2009-2018 based on entropy weight method and coupling coordination model. The results showed that on the whole, comprehensive indexes of the two systems show a trend of first declining and then rising, the development stage of coupling and coordination has entered good coordination stage from primary coordination stage, and the development type of coupling and coordination belongs to the lag of agricultural ecological protection. In terms of regions, Guizhou has the highest comprehensive level of grain production, and Anhui has the lowest; the region with the highest comprehensive level of agricultural ecological protection is Chongqing, and the lowest is Jiangxi; only Anhui and Hubei have entered high coordination stage, and only Shanghai, Zhejiang, Chongqing, and Yunnan belong to the type of synchronous development. The results make up for the lack of research on coupling and coordination between grain production and agricultural ecological protection, and provided, a feasible development path for exploring coordinated development of grain production and agricultural ecological protection in the Yangtze River Economic Belt. RESUMO: O Cinturão Econômico do Rio Yangtze é uma importante área de produção de grãos e reserva ecológica na China. É de grande importância prática promover o desenvolvimento coordenado entre a produção de grãos e a proteção ecológica agrícola nesta região. Este artigo analisa o acoplamento e a coordenação da produção de grãos e da proteção ecológica agrícola no Cinturão Econômico do Rio Yangtze durante 2009-2018 com base no método de peso de entropia e no modelo de coordenação de acoplamento. Os resultados mostram que, no geral, os índices abrangentes dos dois sistemas mostram uma tendência de primeiro declínio e depois aumento, o estágio de desenvolvimento de acoplamento e coordenação entrou no estágio de boa coordenação do estágio de coordenação primária, e o tipo de desenvolvimento de acoplamento e coordenação pertence ao atraso da proteção ecológica agrícola. Em termos de regiões, Guizhou tem o maior nível abrangente de produção de grãos, e Anhui tem o menor; a região com o maior nível abrangente de proteção ecológica agrícola é Chongqing, e o menor é Jiangxi; somente Anhui e Hubei entraram no estágio de alta coordenação, e somente Xangai, Zhejiang, Chongqing e Yunnan pertencem ao tipo de desenvolvimento síncrono. Os resultados compensam a falta de pesquisa sobre acoplamento e coordenação entre produção de grãos e proteção ecológica agrícola, e fornecem um caminho de desenvolvimento viável para explorar o desenvolvimento coordenado da produção de grãos e proteção ecológica agrícola no Cinturão Econômico do Rio Yangtze.

Background Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular junctions. While neuroendocrine-immune system dysfunction plays a crucial role in the development of autoimmune diseases, its involvement in MG remains largely unexplored. Kisspeptin, a neuropeptide hormone and endogenous ligand for GPR54 receptor, has been demonstrated to regulate antitumor immunity, antiviral immunity, and several autoimmune diseases. However, the role and mechanism of kisspeptin in MG remain to be elucidated. Methods Serum kisspeptin levels were measured by ELISA in MG patients and experimental autoimmune myasthenia gravis (EAMG) rats. EAMG rats were treated with KP10 (kisspeptin analog) to evaluate its effects on body weight, clinical scores, grip strength, antibody levels, and complement deposition. Hypothalamic Kiss1 expression was assessed using Western blot and immunofluorescence. Stereotactic injection of adeno-associated virus overexpressing Kiss1 was performed to study its regulatory effects on disease progression. CD4 + T cell transfer via tail vein, Western blot, and flow cytometry were employed to investigate KP10’s modulatory effects on CD4 + T cell subsets and the NF-κB signaling pathway. Results Kisspeptin expression was significantly decreased in both MG patient sera and EAMG rat sera, with reduced hypothalamic Kiss1 expression in EAMG rats. Either hypothalamic Kiss1 overexpression or intraperitoneal KP10 administration significantly improved clinical signs in EAMG rats. Further in vivo and in vitro studies revealed that KP10 ameliorated EAMG clinical signs by modulating Th1/Th17/Treg cell balance through inhibition of NF-κB signaling pathway activation in CD4 + T cells. Conclusion This study elucidates that Kisspeptin secreted by hypothalamic participates in MG pathogenesis through the Kisspeptin-GPR54-NF-κB signaling axis by regulating CD4 + T cell subset balance, suggesting that the kisspeptin/GPR54 pathway may serve as a potential therapeutic target for MG treatment.

Background Accurately evaluating the water status of walnuts in different growth stages is fundamental to implementing deficit irrigation strategies and improving the yield of walnuts. The crop water stress index (CWSI) based on the canopy temperature is one of the most commonly used tools for current research on plant water monitoring. However, the suitability and effectiveness of using the CWSI as an indicator of the walnut water status under field conditions are still unclear. This paper focuses on walnut orchards in Northwest China using synchronous monitoring of the canopy temperature, meteorological parameters, and water physiological parameters of walnut trees under both full irrigation and deficit irrigation treatments. The aim is to test the effectiveness of the simplified crop water stress index (CWSI s ) and the theoretical crop water stress index (CWSI t ) in tracking the diurnal and daily variations of the water conditions in walnut orchards. Results The CWSI s can reflect the diurnal and daily changes in the water status of walnut orchards. It was found that the CWSI s at 12:00 local time had the best performance in tracking the daily changes in the water status. Compared to the daily averaged CWSI calculated using the measured transpiration (CWSI Tr_day ), the correlation coefficient, index of agreement, and root mean squared error between the CWSI s and CWSI Tr_day were 0.82, 0.94, and 0.11, respectively. However, due to the calculation errors of the aerodynamic resistance in walnut trees, the CWSI t was unable to track the diurnal variations in the water status in walnut orchards and the degree of water stress was underestimated. In addition, the variations in minimum canopy resistance in the various growth stages of walnut orchards may also affect the accuracy of the CWSI t in terms of indicating the seasonal changes in the water status. Conclusions The CWSI s provides a non-destructive, quickly and effective method for monitoring the water status of walnuts. However, the results of this study suggest that the effects of aerodynamic resistance parameterization and variations in minimum canopy resistance in the various growth stages of walnut orchards in the CWSI t calculation should be noted.

PM2.5 plays a significant role in urban climate, especially as urban development accelerates. In this study, surface PM2.5, skin temperature, surface air temperature, net longwave radiation, net shortwave radiation, sensible heat flux, and latent heat flux were directly analyzed in Nanchang from 2020 to 2022. The results indicate that PM2.5 in Nanchang is highest during winter and lowest in summer. On an annual scale, surface PM2.5 reduces skin and surface air temperatures at a rate of 0.75 °C/(μg m−3) by decreasing net solar radiation and increasing net longwave radiation at night. Conversely, it increases air temperature by absorbing radiation, leading to a surface inversion. Furthermore, surface PM2.5 influences surface air and skin temperatures by modulating the latent heat fluxes.

Background Myasthenia gravis (MG) is an autoimmune disorder whose pathogenesis has not been fully elucidated but is primarily associated with immune system dysregulation. Growing evidence indicates that innate immunity mediated by monocyte-macrophages plays a significant role in the pathogenesis of MG. SAMHD1 is a negative regulator of innate immunity, and its involvement in MG remains unclear. This study aims to clarify the immunoregulatory mechanism of SAMHD1 in MG and to explore its potential therapeutic implications. Methods Experimental autoimmune myasthenia gravis (EAMG) rat models were established using purified torpedo acetylcholine receptor (AChR). Peripheral blood samples from MG patients and healthy controls were collected for clinical validation. Single-cell RNA sequencing was performed on peripheral whole blood from EAMG and control rats, as well as on human (GEO database). Serum levels of AChR antibodies were quantified using ELISA, while flow cytometry was employed to detect SAMHD1 expression across different cell types and to analyze the subgroup composition of CD4 + T cells. Immunofluorescence (IF) was performed for C5b-9 and α-BTX at the neuromuscular junctions (NMJ), as well as for γH2AX on macrophages. To investigate the underlying mechanism, macrophages were selectively targeted in vivo via tail vein injection of adeno-associated virus (AAV) vectors driven by the macrophage-specific F4/80 promoter, additionally, macrophages pre-treated with 1 µM STING inhibitor H-151 for 24 h were adoptively transferred into rats. RT-qPCR and western blot analysis techniques were employed to assess mRNA and protein expression levels, respectively. Results Our study revealed a significant reduction of SAMHD1 in monocytes ( p  = 0.0286) and splenic macrophages ( p  = 0.0002) of EAMG rats, as well as in monocytes of MG patients ( p  = 0.0002). Overexpression of SAMHD1 in macrophages significantly increased body weight and grip strength, reduced clinical scores, diminished complement deposition at the NMJ in EAMG rats, and shifted CD4⁺ T cells subset distribution—specifically, decreased frequencies of Th1(5.295 ± 0.2504% v 3.817 ± 1.393%) and Th17 (4.698 ± 1.078% v 2.328 ± 0.8311%) cells and increased frequency of Treg cells (4.087 ± 0.531% v 4.892 ± 0.708%). Mechanistically, SAMHD1 overexpression alleviated macrophage-intrinsic DNA damage, suppressed cGAS-STING pathway activation, and thereby restored the proportions of Th1, Th17 and Treg cells. Conversely, activation of the cGAS-STING pathway increased the proportion of Th1 (2.510 ± 0.4636% v 6.563 ± 1.546%) and Th17 (1.237 ± 0.7205% v 5.368 ± 1.526%) cells again, reduced the number of Treg cells (6.022 ± 0.3579% v 3.908 ± 0.2902%), meanwhile, EAMG rats exhibited progressive weight loss, impaired grip strength, elevated clinical scores, and enhanced complement deposition at the NMJ. Conclusion This study uncovered a previously unrecognized mechanism whereby SAMHD1 downregulation impairs DNA damage repair, thereby triggering cGAS-STING pathway activation, immune dysregulation, and subsequent exacerbation of MG pathogenesis. These findings provide new insights into the pathogenesis of MG and identify SAMHD1 and the cGAS-STING axis as promising therapeutic targets for MG intervention. Graphical Abstract

Examining the land-atmosphere interaction in vegetation rehabilitation areas is important for better understanding of land surface processes affected by human activities. In this study, energy flux observations were used to investigate surface energy partitioning and evapotranspiration (ET) in a Pinus tabuliformis plantation in Northeast China in 2020 and 2021. The sensible heat flux (H) was the dominant component of R n , and the ratio of H to the latent heat flux was higher than 1 at all growth stages. The two most important factors influencing the midday evaporative fraction and daily ET were the normalized difference vegetation index (NDVI) and soil water content at 10 cm depth (SWC 10 ). Cumulative precipitation (P) minus ET was 62.83 and 239.90 mm in 2020 (annual P of 435.2 mm) and 2021 (annual P of 632.8 mm), respectively. The midday Priestley–Taylor coefficient (α), surface conductance (g s ), and decoupling coefficient increased gradually from the onset of the mid-growing stage and decreased from the later growing stage. Midday α and g s increased with NDVI and SWC 10 increasing until the NDVI (0.5) and SWC 10 (0.17 mm 3 mm −3 ) thresholds were reached, respectively. Midday α and g s were significantly influenced by vapor pressure deficit below 3 kPa, and the threshold value of midday g s was approximately 12 mm s −1 . In conclusion, this Pinus tabuliformis plantation regulated surface energy partitioning properly, and left a part of P for surface runoff and groundwater recharge in the semiarid region of Northeast China.

Canopy temperature (Tc) is used to characterize plant water physiology, and thermal infrared (TIR) remote sensing is a convenient technology for measuring Tc in forest ecosystems. However, the images produced through this method contain background pixels of forest gaps, thereby reducing the accuracy of Tc observations. Extracting Tc data from TIR images is of great significance for understanding changes in ecosystem water status. In this study, a temperature threshold method was developed to rapidly, accurately, and automatically extract forest canopy pixels for Tc data obtention. Specifically, this method takes the temperature corresponding to the point with a slope of 0.5 in the curve composed of the normalized average temperature and the normalized cumulative number of pixels as the segmentation threshold to separate the forest gap pixels from the forest canopy pixels in the TIR images and extract the separated forest canopy pixels based on the pixel coordinates for Tc data obtention. Taking the Tc values, measured using a thermocouple, as the standard, Tc extraction using the new temperature threshold method and traditional methods (the Otsu algorithm and direct extraction) was compared in cork oak plantations. The results showed that the temperature threshold method offered the highest extraction accuracy, followed by the direct extraction method and the Otsu algorithm. The temperature threshold method was determined to be the most suitable for extracting Tc data from the TIR images of cork oak plantations.

Monitoring drought stress is crucial for estimating productivity and assessing the health status of forest ecosystems under global climate change. Solar-induced chlorophyll fluorescence (SIF) is mechanistically coupled to photosynthesis and has advantages over greenness-based vegetation indices in detecting drought. In recent years, SIF has commonly been used in monitoring drought stress in crop ecosystems. However, the response of tower-based SIF to drought stress in forest ecosystems remains unclear. In this study, we investigated the potential of tower-based SIF to monitor drought, which was quantified using the plant water stress index (PWSI) in a Chinese cork oak plantation. The results show the negative effect of drought on SIF, and afternoon depression of SIF emission under drought stress was observed. Canopy SIF (F) exhibited a nonlinear relationship with PWSI, while the quantum yield of SIF (ΦF) exhibited a significant linear relationship with PWSI at 687 nm and 760 nm (ΦF687: R2 = 0.90; ΦF760: R2 = 0.85). Incident radiation (PAR) and canopy structure affected the response of SIF to drought stress, with PAR as the main factor causing the nonlinear relationship between F and PWSI. Afternoon depression was described as the afternoon/morning ratio (AMR). AMRF and AMRΦF exhibited a negative linear response to PWSI. AMRF was less affected than F by PAR and canopy structures, and AMRΦF was more physiologically representative than ΦF. Moreover, AMRΦF was sensitive to VPD and REW, and it might be a good indicator of drought. Red SIF was more sensitive to drought than far-red SIF, as the R2 of PWSI with AMRΦF687 (R2 = 0.89) was higher than that with AMRΦF687 (R2 = 0.84). These results highlight the potential of tower-based SIF, especially red SIF, for drought monitoring in a plantation, and consideration of the physiological diurnal variation in SIF under drought stress is crucial for improving the accuracy of drought stress monitoring.

Tricuspid valve replacement (TVR), particularly as an isolated procedure, is historically associated with high perioperative risk and poor outcomes. This study aimed to evaluate in-hospital and long-term outcomes of isolated versus concomitant TVR and identify predictors of morbidity/mortality in patients with severe tricuspid regurgitation (TR). This retrospective study included 245 consecutive adult patients who underwent surgical TVR at Beijing Anzhen Hospital between 1993 and 2019. Primary outcomes were in-hospital mortality and long-term survival. Univariate and multivariate logistic regression analyses were conducted to determine factors associated with in-hospital mortality, adjusting for chronic kidney disease (CKD) and TRI-SCORE. Additionally, univariate and multivariate Cox regression analyses were performed to identify factors associated with long-term mortality, adjusting for age, CKD, TRI-SCORE, and previous cardiac surgery history. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were utilized to adjust for baseline differences. Patients were categorized into two groups: isolated TVR (n = 128) and concomitant TVR (n = 117). The mean age was 47 ± 13 years, 58.4% were male, and the mean left ventricular ejection fraction was 62 ± 10%. Isolated TVR patients had lower in-hospital mortality (7.8% vs. 17.9%; = 0.017) compared to concomitant TVR patients. At 1, 5, and 10 years, the survival rates for isolated TVR were 89.1%, 83.3%, and 77.7%, respectively. For concomitant TVR, the corresponding rates were 72.6%, 68.9%, and 60.5%, respectively. Multivariate analysis identified isolated TVR as protective against in-hospital death (odds ratio (OR) = 0.40, 95% confidence interval (CI): 0.17-0.95; = 0.037) and overall mortality (hazard ratio (HR) = 0.49, 95% CI: 0.30-0.81; = 0.005). Additionally, TRI-SCORE and CKD were associated with in-hospital mortality, and both remained significant predictors of long-term mortality. IPTW and PSM analyses confirmed the results. Isolated TVR is associated with lower in-hospital and long-term mortality compared to concomitant TVR. Early referral before multivalve disease progression and meticulous patient selection-particularly avoiding advanced right-sided heart failure or renal dysfunction-may optimize outcomes. These findings advocate for timely isolated TVR in select TR patients to mitigate the compounding risks of delayed intervention.

Light use efficiency (LUE) models have been widely used to estimate terrestrial gross primary production (GPP). However, the estimation of GPP still has large uncertainties owing to an insufficient understanding of the complex relationship between water availability and photosynthesis. The plant water stress index (PWSI), which is based on canopy temperature, is very sensitive to the plant stomatal opening and has been regarded as a good indicator for monitoring plant water status at the regional scale. In this study, we selected a cork oak plantation in northern China with an obvious seasonal drought as the research object. Using the ground-observed data, we evaluated the applicability of the LUE models with typical water stress scalars (MOD17, MODTEM, EC-LUE, ECM-LUE, SM-LUE, GLO-PEM, and Wang) in a GPP simulation of the cork oak plantation and explored whether the model’s accuracy can be improved by applying PWSI to modify the above models. The results showed that among the seven LUE models, the water stress scalar had a greater impact on the model’s performance than the temperature stress scalar. On sunny days, the daily GPP simulated by the seven LUE models was poorly matched with the measured GPP, and all models explained only 23–52% of the GPP variation in the cork oak plantation. The modified LUE models can significantly improve the prediction accuracy of the GPP and explain 49–65% of the variation in the daily GPP. On cloudy days, the performance of the modified LUE models did not improve, and the evaporative fraction was more suitable for defining the water stress scalar in the LUE models. The ECM-LUE and the modified GLO-PEM based on PWSI had optimal model structures for simulating the GPP of the cork oak plantation under cloudy and sunny days, respectively. This study provides a reference for the accurate prediction of GPP in terrestrial ecosystems in the future.