Asymmetric synthesis of indole-annulated medium-sized-ring compounds is developed through an iridium-catalyzed allylic dearomatization/retro-Mannich/hydrolysis cascade reaction. The reaction features ...mild conditions and a broad substrate scope. Under the optimal conditions, various seven-, eight-, or nine-membered-ring compounds can be afforded in good to excellent yields and excellent enantioselectivity. The proposed mechanism is supported by capturing the dearomatized intermediate through in situ reduction.
The diversity of the human microbiome heralds the difference of the impact that gut microbial metabolites exert on allogenic graft-versus-host (GVH) disease (GVHD), even though short-chain fatty ...acids and indole were demonstrated to reduce its severity. In this study, we dissected the role of choline-metabolized trimethylamine N-oxide (TMAO) in the GVHD process. Either TMAO or a high-choline diet enhanced the allogenic GVH reaction, whereas the analog of choline, 3,3-dimethyl-1-butanol reversed TMAO-induced GVHD severity. Interestingly, TMAO-induced alloreactive T-cell proliferation and differentiation into T-helper (Th) subtypes was seen in GVHD mice but not in in vitro cultures. We thus investigated the role of macrophage polarization, which was absent from the in vitro culture system. F4/80+CD11b+CD16/32+ M1 macrophage and signature genes, IL-1β, IL-6, TNF-α, CXCL9, and CXCL10, were increased in TMAO-induced GVHD tissues and in TMAO-cultured bone marrow–derived macrophages (BMDMs). Inhibition of the NLRP3 inflammasome reversed TMAO-stimulated M1 features, indicating that NLRP3 is the key proteolytic activator involved in the macrophage's response to TMAO stimulation. Consistently, mitochondrial reactive oxygen species and enhanced NF-κB nuclear relocalization were investigated in TMAO-stimulated BMDMs. In vivo depletion of NLRP3 in GVHD recipients not only blocked M1 polarization but also reversed GVHD severity in the presence of TMAO treatment. In conclusion, our data revealed that TMAO-induced GVHD progression resulted from Th1 and Th17 differentiation, which is mediated by the polarized M1 macrophage requiring NLRP3 inflammasome activation. It provides the link among the host choline diet, microbial metabolites, and GVH reaction, shedding light on alleviating GVHD by controlling choline intake.
•Choline-derived or orally administered gut microbial metabolite TMAO aggravates GVHD.•TMAO enhances M1 macrophage polarization via NLRP3 inflammasome activation.
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Designing a structurally stable anode with a high reversible capacity for sodium ion batteries (SIBs) is particularly crucial so that batteries are able to meet the requirements for large-scale ...applications in grid electrical energy storage. Polyaromatic hydrocarbons (PAHs) are organic molecules with well-defined structures that demonstrate excellent performance in lithium storage. Based on our well-established correlation between battery property and molecular structure, for the first time, we applied a recently synthesized hexabenzocoronene (HBC) and corresponding derivate HBC-OMe to engage in sodium storage. The HBC molecule forms self-assemblies with a long-range ordered face-center cubed (fcc) structure due to the interaction between two HBC moieties. Such a unique 3D structure is expected to generate a strong π-π interaction between flakes and thus yield amazing durability during the long-term cycling process. In addition, the surface-dominated Na
+
storage mechanism can facilitate the Na
+
transport kinetics and simultaneously alleviate the structural strain during charging-discharging cycles. Benefiting from the coupling effect of the surface-driven capacitive process and the robust 3D self-assembled hierarchical nature, an oxygen-containing sample, HBC-OMe, exhibited an extraordinary sodium storage capability, attaining a high capacity of 506 mA h g
−1
at 0.1 A g
−1
with excellent rate capability (217 mA h g
−1
at 5 A g
−1
) and superior long-term cycling performance (290 mA h g
−1
at 2 A g
−1
with negligible capacity fade after 1000 cycles).
Designing a structurally stable anode with a high reversible capacity for sodium ion batteries (SIBs) is particularly crucial so that batteries are able to meet the requirements for large-scale applications in grid electrical energy storage.
Host–guest encapsulation of electron-rich naphthalene molecules into a weakly emissive porous metal–organic framework based on π-electron-deficient (π-acidic) naphthalene diimide tectons leads to ...orange-emissive crystals, which can be used to sense strongly basic organic amines in a fast response, high photostability, and tunable sensitivity. Moreover, such host–guest inclusion crystals are also a good photochromic probe for the detection of weakly basic N-methyl-2-pyrrolidone and N,N-dimethylformamide molecules.
In this study, thin-film blue-light micro-light-emitting diodes (μLEDs) were successfully fabricated by laser lift-off technique, which had an emission region of only 10 μm × 10 μm. Additionally, a ...texturing treatment was applied to the top undoped GaN surface. The texturing time was optimized to prevent a total reflective effect and further enhance the light extraction efficiency. As a result, the emission output power (@ 30 mA) and EQE max of the μLED textured for 2 minutes exhibited 1.35 times and 1.64 times higher values as compared with those of μLED with a sapphire substrate, respectively.
Among the most difficult difficulties in contemporary satellite image-processing subjects is cloud and cloud shade segmentation. Due to substantial background noise interference, existing cloud and ...cloud shadow segmentation techniques would result in false detection and missing detection. We propose a Location Pooling Multi-Scale Network (LPMSNet) in this study. The residual network is utilised as the backbone in this method to acquire semantic info on various levels. Simultaneously, the Location Attention Multi-Scale Aggregation Module (LAMA) is introduced to obtain the image’s multi-scale info. The Channel Spatial Attention Module (CSA) is introduced to boost the network’s focus on segmentation goals. Finally, in view of the problem that the edge details of cloud as well as cloud shade are easily lost, this work designs the Scale Fusion Restoration Module (SFR). SFR can perform picture upsampling as well as the acquisition of edge detail information from cloud as well as cloud shade. The mean intersection over union (MIoU) accuracy of this network reached 94.36% and 81.60% on the Cloud and Cloud Shadow Dataset and the five-category dataset L8SPARCS, respectively. On the two-category HRC-WHU Dataset, the accuracy of the network on the intersection over union (IoU) reached 90.51%. In addition, in the Cloud and Cloud Shadow Dataset, our network achieves 97.17%, 96.83%, and 97.00% in precision (P), recall (R), and F1 score (F1) in cloud segmentation tasks, respectively. In the cloud shadow segmentation task, precision (P), recall (R), and F1 score (F1) reached 95.70%, 96.38%, and 96.04%, respectively. Therefore, this method has a significant advantage over the current cloud and cloud shade segmentation methods.
In this paper, an optical waveguide evanescent field fluorescence microscopy is studied. Based on Maxwell's equation, a seven‐layer theoretical analysis model is developed for the evaluation of an ...optical waveguide excitation fluorescence microscopy. The optical waveguide excitation fluorescence microscopy structure is systematically and comprehensively analysed at the wavelengths of 488, 532 and 646 nm for fluorescent dyes. The analysis results provide some useful suggestions, which will be beneficial to the research of an optical waveguide evanescent field fluorescence microscopy.
LAY DESCRIPTION
An optical waveguide evanescent field fluorescence microscopy is studied in this paper. Considering the existence of cells, a seven‐layer theoretical analysis model of the optical waveguide excitation fluorescence microscopy is established. Based on this model, the effect of different parameters on the efficiency of optical waveguide excitation fluorescence microscopy is analysed.
Enantioselective synthesis of pyrrole‐annulated medium‐sized‐ring compounds by an iridium‐catalyzed allylic dearomatization/retro‐Mannich/hydrolysis sequence is presented. Various substituted ...pyrrole‐annulated seven‐ and eight‐membered‐ring products were obtained under mild reaction conditions with moderate to good yields and excellent enantioselectivity. Additionally, these products contain a scaffold widely distributed in natural products and biologically active compounds. The current method provides a convenient way for accessing such pyrrole‐anuulated medium‐sized‐ring compounds.
Life without ‘pyrrole': Enantioselective synthesis of pyrrole‐annulated medium‐sized‐ring compounds by an iridium‐catalyzed allylic dearomatization/retro‐Mannich/hydrolysis sequence is presented. Various substituted pyrrole‐annulated seven‐ and eight‐membered‐ring products were obtained under mild reaction conditions with moderate to good yields and excellent enantioselectivity.
Cloud and cloud shadow segmentation is one of the most critical challenges in remote sensing image processing. Because of susceptibility to factors such as disturbance from terrain features and ...noise, as well as a poor capacity to generalize, conventional deep learning networks, when directly used to cloud and cloud shade detection and division, have a tendency to lose fine features and spatial data, leading to coarse segmentation of cloud and cloud shadow borders, false detections, and omissions of targets. To address the aforementioned issues, a multi-scale strip feature attention network (MSFANet) is proposed. This approach uses Resnet18 as the backbone for obtaining semantic data at multiple levels. It incorporates a particular attention module that we name the deep-layer multi-scale pooling attention module (DMPA), aimed at extracting multi-scale contextual semantic data, deep channel feature information, and deep spatial feature information. Furthermore, a skip connection module named the boundary detail feature perception module (BDFP) is introduced to promote information interaction and fusion between adjacent layers of the backbone network. This module performs feature exploration on both the height and width dimensions of the characteristic pattern to enhance the recovery of boundary detail intelligence of the detection targets. Finally, during the decoding phase, a self-attention module named the cross-layer self-attention feature fusion module (CSFF) is employed to direct the aggregation of deeplayer semantic feature and shallow detail feature. This approach facilitates the extraction of feature information to the maximum extent while conducting image restoration. The experimental outcomes unequivocally prove the efficacy of our network in effectively addressing complex cloud-covered scenes, showcasing good performance across the cloud and cloud shadow datasets, the HRC_WHU dataset, and the SPARCS dataset. Our model outperforms existing methods in terms of segmentation accuracy, underscoring its paramount importance in the field of cloud recognition research.
Stream water, groundwater and soil water in the riparian zone are closely linked. Their responses to rainfall events controlled by monsoon climate are variable and intertwined, which are still not ...well known. To address this knowledge gap, we established a monitoring transect adjacent to a headwater stream in Huashan Catchment, eastern China, with typical monsoon climate. We monitored precipitation, stream stage, groundwater level and soil moisture content at intervals of maximum 30 min. We then conducted an event‐based analysis of rainfall event characteristics and diverse response metrics, and assessed their correlations and interrelationships through correlation and regression analysis. Our 2‐year monitoring results show that water level responses occurred in most rainfall events. They had smaller threshold of rainfall amount and timing but longer time to peak response. Stream responses exhibited smaller response magnitude and intensities than groundwater responses. Rainfall amount and event duration were the most critical driving factors for groundwater responses. Soil moisture responses varied with depth. Only large storms could propagate into topsoil and generate rapid responses. Middle soil moisture responses had more frequent response occurrence and more variable response magnitude, while deep soil moisture responses had smaller response magnitude, longer time to peak response and larger wetting front movement velocity. Attenuated initial response timing with depth identified preferential flow, reflecting heterogeneity in the soil profile. Monsoon‐controlled heavy rainfall improved hydrologic connectivity in the soil‐groundwater‐stream continuum (SGSC), mediating the influence of heterogeneity on soil moisture responses and potentially contributing more subsurface flow to catchment runoff. Overall, this study aimed to reveal the mechanism of hydrological responses to monsoon‐controlled precipitation across the SGSC.
In this study, we quantified responses of stream water, groundwater and soil moisture to precipitation across the soil‐groundwater‐stream continuum. High‐frequency hydrometric data and event‐based analysis revealed smaller activation threshold (Rt and Ti) but longer peak duration (Tip) of stream responses, larger magnitude (Rm) of groundwater responses, and preferential flow from depth‐varying soil moisture responses. Short‐duration monsoon‐controlled heavy rainfall mediated the effect of vertical subsurface heterogeneity, whereas long‐duration monsoon‐controlled heavy rainfall potentially enhanced hydrologic connectivity and subsurface contribution to catchment runoff.
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