Stroke is a prevalent cerebrovascular condition with a global impact, causing significant rates of illness and death. Despite extensive research, the available treatment options for stroke remain ...restricted. Hence, it is crucial to gain a deeper understanding of the molecular mechanisms associated with the onset and advancement of stroke in order to establish a theoretical foundation for novel preventive and therapeutic approaches. NF-κB, also known as nuclear factor κB, is a transcription factor responsible for controlling the expression of numerous genes and plays a crucial role in diverse physiological processes. NF-κB is triggered and regulates neuroinflammation and other processes after stroke, promoting the generation of cytokine storms and contributing to the advancement of ischemic stroke (IS). Therefore, NF-κB could potentially play a vital role in stroke by regulating diverse pathophysiological processes. This review provides an overview of the functions of NF-κB in stroke and its governing mechanisms. In addition, our attention is directed towards various potential therapies that aim to inhibit the NF-κB signaling pathway in order to offer valuable insights for the advancement of innovative treatment approaches for stroke.
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●NF-κB plays a key role in neuroinflammation following ischemic stroke.●NF-κB is involved in regulating the pathological mechanisms of ischemic stroke.●A series of therapies exert neuroprotective effects on ischemic stroke via inhibiting NF-κB signalling pathway.
SiC ceramics are attractive electromagnetic (EM) absorption materials for the application in harsh environment because of their low density, good dielectric tunable performance, and chemical ...stability. However, the performance of current SiC-based materials to absorb EM wave is generally unsatisfactory due to poor impedance matching. Herein, we report ultralight SiC/Si3N4 composite aerogels (~15 mg·cm−3) consisting of numerous interweaving SiC nanowires and Si3N4 nanoribbons. Aerogels were prepared via siloxane pyrolysis and chemical vapor reaction through the template method. The optimal aerogel exhibits excellent EM wave absorption properties with a strong reflection loss (RL, −48.6 dB) and a wide effective absorption band (EAB, 7.4 GHz) at a thickness of 2 mm, attributed to good impedance matching and multi attenuation mechanisms of waves within the unique network structure. In addition, the aerogel exhibits high thermal stability in air until 1000 ℃ and excellent thermal insulation performance (0.030 W·m−1·K−1). These superior performances make the SiC/Si3N4 composite aerogel promising to become a new generation of absorption material served under extreme conditions.
Rainfall is one of the primary sources of chemical inputs in forest ecosystems, and the basis of forest nutrient cycling. Mixed evergreen and deciduous broadleaved forests are currently one of the ...most threatened ecosystems due to their sensitivity to anthropogenic climate change. As such, understanding the hydrochemical fluxes of these systems is critical for managing their dynamics in the future. We investigate the chemistry of bulk precipitation, stemflow and throughfall in a mixed evergreen and deciduous broadleaved forest in the Shennongjia region of Central China. Mean nutrient concentrations in throughfall and stemflow were higher than in bulk precipitation. Stemflow ion fluxes from deciduous tree species were greater than those for evergreen tree species because of the differences in bark morphology and branch architecture. Throughfall and stemflow chemistry fluctuated dramatically over the growing season. Nitrate nitrogen and ammonium nitrogen were retained, while other elements and compounds were washed off or leached via throughfall and stemflow pathways. Our findings will facilitate a greater understanding of nutrient balance in canopy water fluxes.
Case histories have shown that the liquefaction-induced lateral spreading is one of the main causes of damage to pile foundations subjected to seismic loading. This study will investigate the effect ...of lateral spreading on a single pile behind a quay wall. A shake-table experiment on a single pile embedded in a fully saturated sand stratum is conducted. The ground surface and pile head displacement are in close agreement prior to liquefaction. Upon liquefaction, soil acceleration is clearly attenuated. Simple liquefied lateral soil pressure analysis approaches (uniform and triangular) are calibrated using the experimental results. Subsequently, a Beam on Nonlinear Winkler Foundation (BNWF) model is proposed, and the response is compared to the experimental results. It is found that the proposed BNWF model better predicts the observed pile response compared to the simple soil pressure approaches. A parametric study through the BNWF model is performed to explore the effect of several salient factors on the pile behavior. On this basis, it is shown that a larger pile bending stiffness decreases the lateral spreading-induced deformation, and a larger pile diameter for the same stiffness results in a higher displacement and bending moment.
•Soil behavior and pile response prior to and during lateral spreading are presented.•A lateral flow pressure distribution scenario due to lateral spreading is further calibrated.•A BNWF model implemented in OpenSees has been developed.•Influences of several key factors on elastic pile behavior are examined.
Precipitation amount and seasonality can profoundly impact ecosystem carbon (C) and water fluxes. Water use efficiency (WUE), which measures the amount of C assimilation relative to the amount of ...water loss, is an important metric linking ecosystem C and water cycles. However, how increasing precipitation at different points in the growing season affects ecosystem WUE remains unclear. A manipulative experiment simulating increasing first half (FP+) and/or second half (SP+) of growing-season precipitation was conducted for 4 years (2015-2018) in a temperate steppe in the Mongolian Plateau. Gross ecosystem productivity (GEP) and evapotranspiration (ET) were measured to figure out ecosystem WUE (WUE = GEP/ET). Across the four years, FP+ showed no considerable impact on ecosystem WUE or its two components, GEP and ET, whereas SP+ stimulated GEP but showed little impact on ET, causing a positive response of WUE to FP+. The increased WUE was mainly due to higher soil water content that maintained high aboveground plant growth and community cover while ET was stable during the second half of growing season. These results illustrate that second half of growing-season precipitation is more important in regulating ecosystem productivity in semiarid grasslands and highlight how precipitation seasonality affects ecosystem productivity in the temperate steppe ecosystem.
Principles of pulse shaping aiming larger pulse energy in fiber lasers are reviewed. From conventional solitons generated in the anomalous dispersion regime, stretched pulses in dispersion-managed ...fiber lasers, similaritons in normal dispersion regime, dissipative solitons in large normal dispersion regime, and amplifier similaritons in fiber lasers with narrow bandwidth filtering to dissipative-soliton-resonance (DSR) pulses in fiber lasers, scaling of pulse energy from picojoule level to microjoule is successfully achieved. DSR is a possible way to achieve endless pulse energy, which is limited by the available pump power and material damage threshold. Properties of DSR pulses are reviewed. Specifically, we experimentally and numerically demonstrate tilt-top DSR pulses in a normal dispersion mode-locked fiber laser. Two fronts of the tilt-top pulses exhibit different intensity, and the intensity disparity maintains while the pulses extend with increasing gain. The tilt-top DSR pulses have rectangular spectral pedestal and a peak. The spectral peak deviates from the center of the rectangle spectral pedestal. Further results show that the asymmetry of two fronts is closely related to the wavelength deviation of spectral peak. Numerical simulations reveal the importance of the saddle-type spectral filtering on asymmetric DSR pulse generation.
Recent booming advances in luminescent gold nanoclusters (AuNCs), have prompted the development of novel fluorescent sensors. The luminescent AuNCs possess unique and intriguing physical and chemical ...properties including responsive photoluminescence and peroxide-like activity, providing abundant potentials for sensing strategy design. As of now, a wide variety of chem-/bio-sensors based on AuNCs have been developed and reviewed according to varied analytes. In this review, from a different point of view, we follow the route of how those sensors realize their functions and focus on the actual roles AuNCs play, in order to hierarchically and logically display the recent progress in the sensing applications of AuNCs. This review not only opens new windows to understand the development of sensors based on AuNCs but can also inspire broader and deeper utilization of luminescent nanomaterials.
Blunt snout bream plays an important role in freshwater aquaculture in China, but the development of its culture industry has been restricted by increasing hypoxia problem. Through the breeding of ...wild blunt snout bream populations (F0), a hypoxia-tolerant new variety (F6) was obtained. In this study, the new variety was stressed under low oxygen concentration (2.0 mg·L
−1
) for 4 and 7 days, the morphological structure of the gill tissue showed a striking change, the interlamellar cell mass (ILCM) volume reduced significantly (
P
< 0.05), and the lamellar respiratory surface area enlarged significantly (
P
< 0.05), compared to normoxic controls. After 7 days of oxygen recovery, gill remodeling was completely reversed. Additionally, the TUNEL-positive apoptotic fluorescence signals increased in the gills exposed to hypoxia up to 4 and 7 days; the apoptosis rate also increased significantly (
P
< 0.05). Under 4 and 7 days of hypoxia stress, the expression of anti-apoptotic gene
Bcl-2
in the gills downregulated significantly (
P
< 0.05), with the significantly (
P
< 0.05) upregulated expression of pro-apoptotic gene
Bad
. Furthermore, under hypoxia stress, the activity or content of oxidative stress–related enzymes (superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and glutathione (GSH)) in gill tissue increased to varying degrees compared to normoxic controls. These results offer a new perspective into the cellular and molecular mechanism of hypoxia-induced gill remodeling in blunt snout bream and a theoretical basis for its hypoxia adaptation mechanism.
Multiple‐qubit logic gates, as an essential part of quantum logic gates, have wide practical application in quantum computation. Here, a scheme to directly construct a multiple‐qubit logic gate ...CkUm${\rm C}_{k}{\rm U}^{m}$, in which k control atoms apply an universal operation U on each of m target qubits in the Rydberg atom system is proposed. The scheme, based on Rydberg blockade and geometric quantum operations as well as optimized control theory, can greatly reduce the qubit number and the operation steps, improving the speed and robustness of the gating compared to the conventional multiple‐qubit gates consisting of single‐ and two‐qubit gates. Taking the C2U2 gate as an example, the performance of the proposal is numerically evaluated in terms of the fidelity of the quantum gate as well as the robustness against the static systematic errors and spontaneous emission. This work may provide a significative reference for constructing universal multiple‐qubit logic gates in future Rydberg atom experiments.
A novel nonadiabatic geometric quantum computation method is used to obtain arbitrary multiple‐qubit gates in Rydberg atom system. The directly constructing multiple‐qubit geometric logic gates prepared by combining nontraditional nonadiabatic geometric quantum computation with the single‐shot shaped pulse optimization theory, a fast and robust k control‐ and m target‐atoms (CkUm) high fidelity universal multiple‐qubit gates is achieved.
Summary
Cucumber mosaic virus suppressor 2b (CMV2b) is a nuclear viral suppressor that interferes with local and systemic silencing and inhibits AGO1 slicer activity. CMV2b‐mediated transgene ...hypomethylation and its localization in Cajal bodies suggests a role of CMV2b in RNA‐directed DNA methylation (RdDM). However, its direct involvement in RdDM, or its binding with small RNAs (sRNAs) in vivo is not yet established. Here, we show that CMV2b binds both microRNAs (miRNAs) and small interfering RNAs (siRNAs) in vivo. sRNA sequencing data from the CMV2b immunocomplex revealed its preferential binding with 24‐nt repeat‐associated siRNAs. We provide evidence that CMV2b also has direct interaction with the AGO4 protein by recognizing its PAZ and PIWI domains. Subsequent analysis of AGO4 functions revealed that CMV2b reduced AGO4 slicer activity and the methylation of several loci, accompanied by the augmented accumulation of 24‐nt siRNAs in Arabidopsis inflorescences. Intriguingly, CMV2b also regulated an AGO4‐related epiallele independently of its catalytic potential, which further reinforces the repressive effects of CMV2b on AGO4 activity. Collectively, our results demonstrate that CMV2b can counteract AGO4‐related functions. We propose that by adopting novel counter‐host defense strategies against AGO1 and AGO4 proteins, CMV creates a favorable cellular niche for its proliferation.
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