Browse Articles
Discover research articles across all indexed journals
Ion-Conductive Wires Form High-Performance All-Solid-State Polymer Electrolytes
Metabotropic glutamate receptor 5 expression associates with pain and inflammatory pathways in interstitial cystitis
Experimental investigation and predictive model of entire suction range for undisturbed granite residual soil
Abstract Undisturbed granite residual soil (UGRS) in its natural state has gained attention for its broad engineering applications. Compared to remolded soils, it closely mimics natural conditions, holds unique significance in geotechnical engineering, crucial for stability analyses, environmental protection, and infrastructure development. In this study, the soil-water characteristic curve (SWCC) of UGRS were measured using indirect methods, including Pressure plate method (PPM), Filter paper method (FPM) and Vapor equilibrium method (VEM) under different wet-dry cycles. Mercury intrusion porosimetry (MIP) was conducted to obtain the pore size distribution (PSD), from which the SWCC was derived. A key novelty of this study lies in the systematic comparison and integration of experimental and pore-structure-derived SWCCs, revealing that the combination of FPM, VEM, and MIP without performing PPM can reliably cover the entire suction range while significantly reducing testing time. Test results indicate that the combination of PPM, FPM, and VEM can cover the entire range of matric suction of UGRS. However, discrepancies arise in the overlapping section where PPM records higher values than FPM. The SWCC can be derived through calculations based on the PSD of MIP. The SWCC calculated by MIP closely aligns with PPM in the low suction range of 0-100 kPa, which is the primary range of engineering concern. The combination of FPM, VEM and MIP without the PPM is the optimal method for entire suction range SWCC determination of UGRS, ensuring data accuracy while mitigating the prolonged time consumption and high data points in the low suction section of the PPM. The SWCC of UGRS can be fitted using the Fredlund&Xing model. The fitting parameters of the SWCC of UGRS can establish a strong linear correlation with the number of wet-dry cycles, enabling the establishment of a model that predicts the SWCC of UGRS across the entire suction range by incorporating pore structure evolution and cyclic effects. The results offer an efficient and accurate alternative for full-range SWCC determination and provide a basis for predicting hydraulic behavior of UGRS under cyclic environmental conditions.
Strong Exciton Confinement Enabling Near-Unity Photoluminescence Quantum Efficiency in Hybrid Bimetallic Halides
Damping factor estimation of damped complex sinusoidal signals using a maximum likelihood approach
Abstract This paper presents an approximate Maximum Likelihood (ML) estimation framework for estimating the damping factor in exponentially decaying complex sinusoidal signals. We derive a closed-form approximate ML estimator, explicitly noting its validity for small damping factors. Its efficiency is assessed through the derivation of the Cramer–Rao Lower Bound (CRLB), which serves as the theoretical benchmark for estimator performance. Analytical proof demonstrates that the proposed approximate ML estimator achieves the CRLB under small-damping conditions, confirming its statistical efficiency and optimality. The performance of the estimator is evaluated by analyzing its behavior with respect to critical system parameters such as signal-to-noise ratio (SNR), sample size, signal amplitude, and damping intensity. Our analysis reveals several fundamental relationships: estimation accuracy improves with increasing SNR and a larger sample size, confirming that the approximate ML estimator effectively utilizes additional information. Furthermore, the empirical variance of the approximate ML estimator converges to the CRLB, validating its efficiency. These findings yield practical guidelines for system designers. We establish that weakly damped signals can achieve satisfactory accuracy with moderate resources, whereas strongly damped scenarios necessitate substantially enhanced signal conditions. The proposed framework provides optimal estimation performance while also achieving significantly reduced computational complexity. This combination makes it particularly suitable for applications requiring rapid damping parameter extraction, such as structural health monitoring, radar systems, and vibration analysis.
A Polymer Backbone Editing Strategy for Property Enhancement
Optical pumping effect on modulation transfer spectroscopy of the $$D_1$$ line of $$^{85}$$Rb atoms with non-cycling transition
Novelty, Ecological Relevance, and Sexual Receptivity Modulate Neuronal Interactions between the Amygdala and Hippocampus
Many studies have demonstrated that the basolateral complex of the amygdala (BLA) can facilitate offline consolidation processes in the hippocampus. However, an open question is how online neuronal oscillations in these regions dynamically couple at the moment of encoding to enable an episodic prioritization for important ecologically relevant stimuli. In the current study, local field potentials (LFPs) were recorded in the BLA and hippocampus (ventral CA1) of female rats as they spontaneously explored many novel and repeated plant-based odors and rat urine odors, which convey ecologically relevant information about conspecifics. Rats’ estrous cycle was tracked and used to estimate sexual receptivity. Moments of exploring urine odors, particularly from male donors, were associated with different neural activity in the BLA and hippocampus versus plant-based odors, activity that also depended on the novelty of the odors as well as the rats’ sexual receptivity. Specifically, prominent slow-gamma (20–50 Hz) oscillations during odor exploration showed a BLA-to-hippocampus directionality and were associated with odor novelty, odor category (male urine vs female urine vs plant-based odors), and better subsequent memory. Spiking-associated (150–200 Hz) activity in the LFPs was also influenced by odor novelty and odor category and was significantly higher in both the BLA and hippocampus on days for which the rats were sexually receptive. Thus, stimulus novelty and ecological relevance combined with the rats’ emotional state to shape the neural correlates of prioritized encoding. The results are discussed in terms of endogenous mechanisms of memory enhancement for important to-be-remembered stimuli.
Medium-Range Structural Order in Amorphous Arsenic
Assessment of coastal bedrock groundwater quality in Jiaodong Peninsula via extension cloud model and resampling strategy
A Time-Sensitive Plasticity Distinguishes the Rapid and Sustained Synaptic Actions of Ketamine from Its (2 <i>R</i> ,6 <i>R</i> )-Hydroxynorketamine Metabolite
( R , S )-Ketamine (ketamine) induces rapid and sustained antidepressant-relevant neuroplastogenic effects in vivo. The metabolite (2 R ,6 R )-hydroxynorketamine (2R6R) forms shortly after the administration of ketamine and independently elicits rapid plasticity and sustained metaplasticity. Ketamine’s therapeutic actions appear to result from distinct, time-sensitive plasticity phases, though the mechanisms that mediate these phases and whether these synaptic actions are unique to ketamine or 2R6R remain poorly understood. Here, we distinguished the synaptic actions of ketamine from its metabolites at the hippocampal Schaffer collateral→CA1 (SC→CA1) synapse. By modifying ketamine’s chemical structure to hinder its metabolism to 2R6R or exposing slices to ketamine or 2R6R in vitro, we find that 2R6R, but not ketamine itself, induces rapid and sustained metaplasticity in both male and female mice. 2R6R's acute plasticity and sustained metaplasticity required mammalian target of rapamycin (mTOR)-dependent signaling, and both phases of 2R6R's synaptic effects were mimicked by pharmacological mTOR activation. Rapid, mTOR-dependent potentiation evoked by 2R6R was followed by long-lasting antidepressant–relevant behavior and metaplasticity that required activation of the inositol trisphosphate receptor. L-type Ca 2+ channel signaling was required for only sustained synaptic actions, consistent with 2R6R's metaplasticity being activity-dependent. Pharmacological or antibody TrkB blockade after, but not before, 2R6R treatment prevented metaplastic synaptic priming, indicating a delayed contribution of BDNF/TrkB signaling. Blocking protein synthesis did not prevent 2R6R-induced metaplasticity. Our results implicate a sequence of plasticity mechanisms underlying 2R6R’s synaptic actions in the hippocampus. These findings are relevant for the delineation of activity-dependent and time-sensitive synaptic mechanisms relevant to the treatment of neuropsychiatric disorders.