Internal Signals Research Articles

Determining the Antenna Phase Center for the High-Precision Positioning of Smartphones.

In recent years, smartphones have emerged as the primary terminal for navigation and location services among mass users, owing to their universality, portability, and affordability. However, the highly integrated antenna design within smartphones inevitably introduces interference from internal signal sources, leading to a misalignment between the antenna phase center (APC) and the antenna geometric center. Accurately determining a smartphone's APC can mitigate system errors and enhance positioning accuracy, thereby meeting the increasing demand for precise and reliable user positioning. This paper delves into a detailed analysis of the generation of Global Navigation Satellite System (GNSS) receiver antenna phase center errors and proposes a method for correcting the receiver antenna phase center. Subsequently, a smartphone positioning experiment was conducted by placing the smartphone on an observation column with known coordinates. The collected observations were processed in static relative positioning mode, referencing observations from geodetic-grade equipment, and the accuracy of the static relative positioning fixed solution was evaluated. Following weighted estimation, we determined the antenna phase center of the Xiaomi Mi8 and corrected the APC. A comparison of the positioning results of the Xiaomi Mi8 before and after APC correction revealed minimal impact on the standard deviations (STDs) but significant influence on the root mean square errors (RMSEs). Specifically, the RMSEs in the E/N/U direction were reduced by 59.6%, 58.5%, and 42.0%, respectively, after APC correction compared to before correction. Furthermore, the integer ambiguity fixing rate slightly improved after the APC correction. In conclusion, the determination of a smartphone's APC can effectively reduce system errors in the plane direction of GNSS positioning, thereby enhancing smartphone positioning accuracy. This research holds significant value for advancing high-precision positioning studies related to smartphones.

Calmodulin-like protein MdCML15 interacts with MdBT2 to modulate iron homeostasis in apple.

BTB and TAZ domain proteins (BTs) function as specialized adaptors facilitating substrate recognition of the CUL3-RING ubiquitin ligase (CRL3) complex that targets proteins for ubiquitination in reaction to diverse pressures. Nonetheless, knowledge of the molecular mechanisms by which the apple scaffold protein MdBT2 responds to external and internal signals is limited. Here we demonstrate that a putative Ca 2+ sensor, calmodulin-like 15 (MdCML15), acts as an upstream regulator of MdBT2 to negatively modulate its functions in plasma membrane H+-ATPase regulation and iron deficiency tolerance. MdCML15 was identified to be substantially linked to MdBT2, and to result in the ubiquitination and degradation of the MdBT2 target protein MdbHLH104. Consequently, MdCML15 repressed the MdbHLH104 target, MdAHA8's expression, reducing levels of a specific membrane H+-ATPase. Finally, the phenotype of transgenic apple plantlets and calli demonstrated that MdCML15 modulates membrane H+-ATPase-produced rhizosphere pH lowering alongside iron homeostasis through an MdCML15-MdBT2-MdbHLH104-MdAHA8 pathway. Our results provide new insights into the relationship between Ca2+ signaling and iron homeostasis.

Where alcohol use disorder meets interoception: A meta-analytic view on structural and functional neuroimaging data.

Alcohol use disorder (AUD) has been associated with changes in the processing of internal body signals, known as interoception. Changes in brain structure, particularly in the insula, are thought to underlie impaired interoception. As studies specifically investigating this association are largely lacking, this analysis takes an approach that compares meta-analytic results on interoception with recently published meta-analytic results on gray matter reduction in AUD. A systematic literature search identified 25 eligible interoception studies. Activation likelihood estimation (ALE) was used to test for spatial convergence of study results. Overlap between interoception and AUD clusters was tested using conjunction analysis. Meta-analytic connectivity modeling (MACM) and resting-state functional connectivity were used to identify the functional network of interoception and to test where this network overlapped with AUD meta-analytic clusters. The results were characterized using behavioral domain analysis. The interoception ALE identified a cluster in the left middle insula. There was no overlap with clusters of reduced gray matter in AUD. MACM analysis of the interoception cluster revealed a large network located in the insulae, thalami, basal nuclei, cingulate and medial frontal cortices, and pre- and postcentral gyri. Resting state analysis confirmed this result, showing the strongest connections to nodes of the salience- and somatomotor network. Five of the eight clusters that showed a structural reduction in AUD were located within these networks. The behavioral profiles of these clusters were suggestive of higher-level processes such as salience control, somatomotor functions, and skin sensations. The results suggest an altered salience mapping of interoceptive signals in AUD, consistent with current models. Connections to the somatomotor network may be related to action control and integration of skin sensations. Mindfulness-based interventions, pleasurable touch, and (deep) transcranial magnetic stimulation may be targeted interventions that reduce interoceptive deficits in AUD and thus contribute to drug use reduction and relapse prevention.

Fe-MOF/AuNP-based ratiometric electrochemical immunosensor for the detection of deoxynivalenol in grain products.

Aratiometric assay was designed to improve the sensitivity and reliability of electrochemical immunosensors for deoxynivalenol (DON) detection. The indicator signal caused by the Fe-based metal-organic framework nanocomposites loaded with gold nanoparticles and the internal reference signal from the [Fe(CN)6]3-/4- in the electrolyte came together at the immunosensor. When immunoreactivity occurred, the indicator signals decreased as the concentration of DON increased, while the internal reference signals increased slightly. The ratio of the indicator signal to the internal reference signal was available for reproducible and sensitive monitoring of DON. The prepared immunosensor showed excellent performance in the range from 0.5 to 5000 pg mL-1, and the detection limit was 0.0166 pg mL-1. The immunosensor achieved satisfactory detection toward DON in spiked and actual samples and has a promising application in the control of DON in grain products.

Integrative Phytohormone and Transcriptome Analyses Reveal the Inhibitory Mechanism of Ethylene on Potato Tuber Sprouting at Room Temperature

As a commercial potato sprout suppressant, ethylene (Eth) is usually used under a low temperature for long-term storage of potato tubers. However, in many cases, potato tubers are usually transferred from a refrigeration house and sold at room temperature. In the present research, Eth’s inhibitory effects on tuber sprouting at room temperature were investigated. The potential molecular mechanisms of Eth-induced sprout suppression were revealed by phytohormone and transcriptome analyses. Results showed that exogenous Eth significantly suppressed sprout growth in potato tubers during two weeks of storage. The endogenous plant hormone levels of abscisic acid (ABA) and auxin (Aux) were markedly reduced by Eth treatment. Transcriptomic analysis revealed that more transcriptional changes occurred in the early stage of sprouting. The differentially expressed genes (DEGs) assigned to the pathways of plant hormone signal transduction, photosynthesis, starch and sucrose metabolism and phenylpropanoid biosynthesis, which were closely associated with sprouting, were extensively down-regulated by Eth treatment. In addition, the heat map of six hormone signal transduction pathways showed that the expression of most DEGs annotated into the Aux signal transduction pathway was suppressed by Eth treatment, while the expression of many DEGs annotated as ETR (Eth receptor) and ERF1/2 (Eth-responsive transcription factor 1 and 2) in the Eth signal transduction pathway was enhanced by Eth treatment. Taken together, our results indicated that Eth-induced sprout inhibition might be closely related to the suppression of internal Aux production and signal transduction and the activation of Eth signal transduction.

PIEZO ion channels: force sensors of the interoceptive nervous system.

Many organs are designed to move: the heart pumps each second, the gastrointestinal tract squeezes and churns to digest food, and we contract and relax skeletal muscles to move our bodies. Sensory neurons of the peripheral nervous system detect signals from bodily tissues, including the forces generated by these movements, to control physiology. The processing of these internal signals is called interoception, but this is a broad term that includes a wide variety of both chemical and mechanical sensory processes. Mechanical senses are understudied, but rapid progress has been made in the last decade, thanks in part to the discovery of the mechanosensory PIEZO ion channels (Coste etal., 2010). The role of these mechanosensors within the interoceptive nervous system is the focus of this review. In defining the transduction molecules that govern mechanical interoception, we will have a better grasp of how these signals drive physiology.

Multitype chatter detection via multichannelinternal and external signals in robotic milling

Robot milling chatter monitoring is susceptible to interference from robot pose, feed direction, inertial excitation-dominated low-frequency flexible vibration (IELFFV), and spindle noise. Therefore, this paper proposes a multi-type chatter detection method utilizing multi-channel internal and external signals. First, the multichannel vibration signals and internal controller signals were acquired and aligned. The vibration signals were converted into an engagement coordinate system. Then, based on the milling vibration signal characterization and sensitivity analysis of vibration signals to chatter, a combination of three chatter indicators, calculated via filtered displacement, filtered acceleration, and internal signals, was utilized to detect structural mode-dominated low-frequency chatter, IELFFV, and tool mode-dominated high-frequency chatter. Finally, the effectiveness of the proposed method in detecting the multitype chatter was demonstrated via robot milling experiments. However, the process of the tool entering and exiting the workpiece could be misclassification as TMHFC, which would be addressed in subsequent research.

When pyro(ptosis) meets palm(itoylation)

Pyroptosis, a programmed cell death process, is vital for the immune response against microbial infections and internal danger signals. Recent studies have highlighted the importance of protein palmitoylation, a modification that involves attaching palmitate to cysteine residues, in regulating key proteins involved in pyroptosis. Palmitoylation of cGAS at residue C474 by ZDHHC18 affects its enzymatic activity and DNA binding ability. Similarly, ZDHHC9 promotes cGAS activity through palmitoylation at residues C404/405. NLRP3 palmitoylation at residue C844, mediated by ZDHHC12, impacts its stability and interactions with other proteins, crucial for activating the NLRP3 inflammasome and triggering inflammation. However, the role of ZDHHC5 in NLRP3 palmitoylation remains uncertain due to conflicting findings. Palmitoylation at C88/91 is essential for STING activation and induction of type I interferons. It modulates the formation of multimeric complexes and downstream signaling pathways. GSDMD palmitoylation at C191 is necessary for pore formation and membrane translocation, while GSDME palmitoylation at C407/408 is associated with drug-induced pyroptosis. Moreover, palmitoylation of NOD1 and NOD2 influences their membrane recruitment and immune signaling pathways in response to bacterial peptidoglycans, acting as upstream regulators of pyroptosis. This review summarizes the important roles for palmitoylation in regulating the function of key pyroptosis-related proteins, shedding light on the intricate mechanisms governing immune responses and inflammation.

Deletion of the sugar importer gene OsSWEET1b accelerates sugar starvation-promoted leaf senescence in rice.

Leaf senescence is a combined response of plant cells stimulated by internal and external signals. Sugars acting as signaling molecules or energy metabolites can influence the progression of leaf senescence. Both sugar starvation and accumulation can promote leaf senescence with diverse mechanisms that are reported in different species. Sugars Will Eventually be Exported Transporters (SWEETs) are proposed to play essential roles in sugar transport, but whether they have roles in senescence and the corresponding mechanism are unclear. Here, we functionally characterized a sugar transporter, OsSWEET1b, which transports sugar and promotes senescence in rice (Oryza sativa L.). OsSWEET1b could import glucose and galactose when heterologously expressed in Xenopus oocytes and translocate glucose and galactose from the extracellular apoplast into the intracellular cytosol in rice. Loss of function of OsSWEET1b decreased glucose and galactose accumulation in leaves. ossweet1b mutants showed accelerated leaf senescence under natural and dark-induced conditions. Exogenous application of glucose and galactose complemented the defect of OsSWEET1b deletion-promoted senescence. Moreover, the senescence-activated transcription factor OsWRKY53, acting as a transcriptional repressor, genetically functions upstream of OsSWEET1b to suppress its expression. OsWRKY53-overexpressing plants had attenuated sugar accumulation, exhibiting a similar phenotype as the ossweet1b mutants. Our findings demonstrate that OsWRKY53 downregulates OsSWEET1b to impair its influx transport activity, leading to compromised sugar accumulation in the cytosol of rice leaves where sugar starvation promotes leaf senescence.

Composite adaptive fuzzy bipartite consensus of fractional-order multiagent systems with a switched event-triggered mechanism

This paper focuses on online recorded-data-based composite adaptive fuzzy bipartite consensus control for uncertain fractional-order multiagent systems with interconnected terms and external disturbances by employing a switched-threshold-based event-triggered mechanism (ETM) under the backstepping structure. Fuzzy logic system is used as a universal function approximation to deal with function uncertainties that are not prone to model in the system. A new composite learning adaptive parameter design scheme that synthesizes both prediction error and tracking error is developed to enhance the tracking performance, where the prediction error is raised from the utilization of online recorded data and instantaneous data. A unique switched-threshold-based ETM is introduced, in which the information transmission between the sensor and the controller is imposed on one of the individuals. One merit of this work consists in that it can automatically and rapidly switch and adjust between the fixed threshold and relative threshold ETM according to the amplitude of input signals to balance the network resources and impede the occurrence of pulse phenomenon. In addition, it is theoretically proven that the proposed scheme can ensure that all internal signals of the closed-loop system are bounded and achieve local bipartite consistent errors through the fractional Lyapunov stability criterion. Finally, a numerical example is provided to confirm the feasibility of the proposed approach.

The Use of Virtual Sensors for Bead Size Measurements in Wire-Arc Directed Energy Deposition

Having garnered significant attention in the scientific community over the past decade, wire-arc directed energy deposition (arc-DED) technology is at the heart of this investigation into additive manufacturing parameters. Singularly focused on Invar as the selected material, the primary objective revolves around devising a virtual sensor for the indirect size measurement of the bead. This innovative methodology involves the seamless integration of internal signals and sensors, enabling the derivation of crucial measurements sans the requirement for direct physical interaction or conventional measurement methodologies. The internal signals recorded, the comprising voltage, the current, the energy from the welding heat source generator, the wire feed speed from the feeding system, the traverse speed from the machine axes, and the temperature from a pyrometer located in the head were all captured through the control of the machine specially dedicated to the arc-DED process during a phase of optimizing and modeling the bead geometry. Finally, a feedforward neural network (FNN), also known as a multi-layer perceptron (MLP), is designed, with the internal signals serving as the input and the height and width of the bead constituting the output. Remarkably cost-effective, this solution circumvents the need for intricate measurements and significantly contributes to the proper layer-by-layer growth process. Furthermore, a neural network model is implemented with a test loss of 0.144 and a test accuracy of 1.0 in order to predict weld bead geometry based on process parameters, thus offering a promising approach for real-time monitoring and defect detection.

Spontaneous signal generation by an excitable system for cell migration.

Eukaryotic cells exhibit random migration in the absence of extracellular directional cues. This random migration acts as basal motility for various migratory responses such as chemotaxis. The self-organization of random motility requires the internal signals that determine the anterior side of the migrating cell be generated spontaneously from the intrinsic activities of intracellular signaling networks. Recent studies have identified an excitable system as the mechanism of the spontaneous signal generation. Here, we discuss how the excitable system of Ras, a small G protein, regulates signaling networks in Dictyostelium discoideum as a model organism. The excitability produces a domain where an active form of Ras is enriched on the cell membrane without extracellular directional cues, such that Ras serves as the anterior signal. The typical spatiotemporal characteristics are mathematically explained by reaction-diffusion models. These models further enable a quantitative analysis of the dynamics that depends on the internal cellular states and surrounding environments. Downstream of the Ras excitable system, a phosphoinositide metabolic network composed of PI3K, PTEN, PI(3,4,5)P3 and PI(4,5)P2 exhibits bistability to discretize the anterior and posterior regions of the cell membrane. Upstream, a local excitation and global inhibition local excitation global inhibition network, which works for gradient sensing in the presence of chemoattractant gradients, spatiotemporally biases the excitability of Ras for chemotaxis. In parallel with the Ras excitable system, the cGMP signaling pathway constitutes another excitable system of its own periodicity to ensure flexible migratory dynamics. In addition to these intracellular signaling networks, an intercellular signaling network activated by secreted cAMP is coupled with the Ras excitable system for collective cell migration. Finally, we discuss how the excitable system of Ras operates as a platform of information integration by receiving multiple intrinsic and extrinsic signals to ensure spontaneous cellular activity and robust responses in eukaryotic cell migration under natural complex environments.

Development of magnetic fluorescence aptasensor for sensitive detection of saxitoxin based on Fe3O4@Au-Pt nanozymes

In this work, on the basis of Fe3O4@Au-Pt nanozymes (MAP NZs) and aptamer recognition, a magnetic fluorescent aptasensor (MFA) was developed for sensitive and accurate detection of saxitoxin (STX). With the bridge of STX aptamer (AptSTX) and complementary DNA (cDNA), AptSTX decorated MAP NZs (MAP/Apt) and cDNA modified green quantum dots (cDNA@g-QDs) were connected to form MAP/Apt-cDNA@g-QDs complex. As STX behaves a strong binding ability towards AptSTX, it will compete with cDNA and hybridize with Apt to release cDNA@g-QDs. With the addition of TMB, MAP will catalyze TMB to the oxidized TMB (ox-TMB), thereby quenching the fluorescence of g-QDs due to the inner filter effect. Based on this finding, the quantitative relationship between the change in fluorescence of gQDs and STX concentration was explored with a limit of detection (LOD, S/N = 3) of 0.6 nM. An internal standard signal of oxTMB was adopted and reduced the fluctuation of fluorescence signal output. Besides, the fluorescence probe can selectively recognize and detect STX among five marine toxins. Eventually, the MFA method behaved good performance in detecting seafood samples with recoveries of 82.0 % ∼ 102.6 % as well as coefficient of variations (CV) of 7.2 % ∼ 10.3 %. Therefore, the method with internal signal is hopeful to be a potential candidate for sensitive and accurate detection of STX in seafood.

Bring the pain: wounding reveals a transition from cortical excitability to epithelial excitability in Xenopus embryos.

The cell cortex plays many critical roles, including interpreting and responding to internal and external signals. One behavior which supports a cell's ability to respond to both internal and externally-derived signaling is cortical excitability, wherein coupled positive and negative feedback loops generate waves of actin polymerization and depolymerization at the cortex. Cortical excitability is a highly conserved behavior, having been demonstrated in many cell types and organisms. One system well-suited to studying cortical excitability is Xenopus laevis, in which cortical excitability is easily monitored for many hours after fertilization. Indeed, recent investigations using X. laevis have furthered our understanding of the circuitry underlying cortical excitability and how it contributes to cytokinesis. Here, we describe the impact of wounding, which represents both a chemical and a physical signal, on cortical excitability. In early embryos (zygotes to early blastulae), we find that wounding results in a transient cessation ("freezing") of wave propagation followed by transport of frozen waves toward the wound site. We also find that wounding near cell-cell junctions results in the formation of an F-actin (actin filament)-based structure that pulls the junction toward the wound; at least part of this structure is based on frozen waves. In later embryos (late blastulae to gastrulae), we find that cortical excitability diminishes and is progressively replaced by epithelial excitability, a process in which wounded cells communicate with other cells via wave-like increases of calcium and apical F-actin. While the F-actin waves closely follow the calcium waves in space and time, under some conditions the actin wave can be uncoupled from the calcium wave, suggesting that they may be independently regulated by a common upstream signal. We conclude that as cortical excitability disappears from the level of the individual cell within the embryo, it is replaced by excitability at the level of the embryonic epithelium itself.

RHiREM: Intelligent diagnostic framework for pipeline Eddy Current Internal Inspection based on reinforcement learning with hierarchical reward exploration mechanism

Pipeline safety is of paramount importance for socio-economic development, necessitating regular inspection and maintenance. The complexity of the internal pipeline environment and the presence of irregular noise in detection data, however, pose significant challenges to pipeline inspection technologies. Additionally, the reliance on manual expertise for inspection and the absence of standardized assessment criteria further complicate the development of automated inspection methods in this context. To address these challenges, this paper proposes a pipeline anomaly detection framework based on reinforcement learning with hierarchical reward exploration mechanism (RHiREM). It includes two main aspects: Firstly, the hierarchical reward mechanism. By deeply simulating the process of defect recognition based on expert personal experience, the original pipeline data is first adaptively divided into sets of windows with different sizes, and then attribute and type judgments are performed on them. In this way, the approach achieves accurate identification of defects and pipeline structures in scenarios with minimal noise interference. Secondly, the hierarchical exploration mechanism. By leveraging the temporal exploration and spatial exploration, the mechanism enables further deep search and feature learning on complex pipeline signals, and facilitates comprehensive assessment of the relationships between global features and local features across different signals, effectively resolving the difficulties associated with identifying defect signals in the presence of high noise interference. the proposed framework has been demonstrated to automate the detection of complex on-site pipeline internal signals and successfully detected the common anomalies with high F1-score over conventional techniques.

Research on the characteristics of weak magnetic internal detection signals for critical damage in pipeline stress based on density functional theory

Pipeline stress-induced critical damage is a primary cause of sudden pipe ruptures. To investigate the characteristics of weak magnetic internal detection signals related to critical damage in pipeline stress, a magneto-mechanical model was developed based on density functional theory. The model could assess the corresponding relationships among the generalized stacking fault energy (GSFE), critical resolved shear stress (CRSS), atomic magnetic moment, and magnetic signals during the critical damage process of the pipeline. The analysis included examining the influential patterns of different stress directions and materials on the magnetic signals associated with critical damage, followed by the systematic experimental verification.The research results indicated that when the crystal dislocation stress exceeded the CRSS, weak magnetic signals could effectively characterize the critical damage induced by stress, accompanying by a sharp variation in magnetic signals observed during critical damage occurrence. Different stress directions lead to varying energy barriers that must be overcome for critical damage, resulting in distinct magnetic signal features. In the {112} plane, the CRSS increased by 11.07 % compared with {11¯0} plane, and the axial magnetic signal during critical damage was elevated by 1.47 % compared with {11¯0} plane. Variances in magnetic signals for critical damage were assessed for steel pipes of different materials due to differences in processing and composition. Under identical conditions, the magnetic signal difference for critical damage in X80 steel plates was 39 % higher than that in X70 steel plates. Additionally, the magnetic signal difference for critical damage in the circumferential weld of X80 was 53 % higher than that in X80. The findings provided a theoretical basis for monitoring and early warning of critical damage states in pipelines.

Thermally-responsive and reduced glutathione-sensitive folate-targeted nanocarrier based on alginate and pluronic F127 for on-demand release of methotrexate

A specific rheumatoid arthritis (RA)-microenvironment-triggered nanocarrier for RA treatment of a first-line antirheumatic drug (Methotrexate, MTX) has been proposed. Reduced glutathione (GSH) responsivity, cystamine, was first introduced on the alginate backbone, which was then used as the bridge to connect pluronic F127 (temperature-responsive factor) and folic acid (targeting factor for active immune cells), resulting in dual-responsive triggered targeting carrier, PCAC-FA. In vitro study demonstrated that PCAC-FA was preferentially taken up by activated macrophage cells rather than normal ones, suggesting the targeting of PCAC-FA to inflamed tissue. The loading capacity of the designed carrier was 21.23 ± 0.91 %. MTX from the PCAC-FA carrier was significantly accelerated release in the presentation of glutathione or in cold shock condition, proposing the efficacy-controlled release. MTX@PCAC-FA showed excellent hemocompatibility, confirming a suitable application with parenteral administration. Notably, the acute and subacute toxicity in the mice model showed that the toxicity of MTX had significantly reduced after encapsulating in the PCAC-FA carrier. These nanoplatforms not only provide an alternative safe strategy for the clinical treatment of rheumatoid arthritis with MTX but also deliver MTX selectively and provide on-demand drug release via external and internal signals, thus emerging as a promising therapeutic option for precise RA therapy.

Polydopamine-enhanced vertically-ordered mesoporous silica film anti-fouling electrochemical aptasensor for indicator-free Vibrio parahaemolyticus discrimination using stable inherent Au signal

Vertically-ordered mesoporous silica film (VMSF) has proven to be an effective anti-interference and anti-fouling layer in the field of analysis. However, because VMSF is not stable enough in complex samples, its application in sensing field is limited. We herein use mussel-inspired multi-functional agent polydopamine (PDA) to enhance the stability of VMSF on electrode. Owing to the amino-functionalized VMSF combined with amino groups on PDA, superhydrophilicity was achieved which was proved to enhance excellent anti-fouling property. In addition, the electrodeposition of Au nanoparticles (AuNP) in the nanochannel of VMSF serving as an internal electrochemical signal shows excellent electrochemical signal stability, which provides a prerequisite for maintaining the further detection accuracy in complex samples. Finally, we validated the detection performance of the anti-fouling sensing strategy using a foodborne pathogen, Vibrio parahaemolyticus (VP), as a model target. Specifically, the aptamer was modified by covalent bond on the PDA-integrated VMSF interface surface for the recognition of VP. Using shrimp homogenate as a real sample, the anti-fouling detection performance of the aptasensor was verified. The linear range of VP detection in real samples was 103-107 CFU/mL, and the detection limit was 103 CFU/mL. The results show that the anti-fouling aptasensor has excellent anti-interference and stability. It is worth emphasizing that this strategy (using inherent Au signal) enables rapid electrochemical analysis of VP without outer indicators, greatly reducing the difficulty of constructing an electrochemical VP detection strategy.

An Investigation of Cerebral Vascular Functional Properties in Middle-to-Old Age Community People With High Vascular Risk Profiles.

Vascular degeneration is an important cause of brain damage in aging. Assessing the functional properties of the cerebral vascular system may aid early diagnosis and prevention. To investigate the relationships between potential vascular functional markers and vascular risks, brain parenchymal damage, and cognition. Retrospective. Two hundred two general community subjects (42-80 years, males/females: 127/75). 3 T, spin echo T1W/T2W/FLAIR, resting-state functional MRI with an echo-planar sequence (rsfMRI), pseudo-continuous arterial spin labeling (pCASL) with a three-dimensional gradient-spin echo sequence. Cerebral blood flow (CBF) in gray matter calculated using pCASL, blood transit times calculated using rsfMRI, and the SD of internal carotid arteries signal (ICAstd) calculated using rsfMRI; visual assessment for lacunes; quantification of white matter hyperintensity volume; permutation test for quality control; collection of demographic and clinical data, Montreal Cognitive Assessment, Mini-Mental State Examination. Kolmogorov-Smirnov test; Spearman rank correlation analysis; Multivariable linear regression analysis controlling for covariates; The level of statistical significance was set at P < 0.05. Age was negatively associated with ICAstd (β = -0.180). Diabetes was associated with longer blood transit time from large arteries to capillary bed (β = 0.185, adjusted for age, sex, and intracranial volume). Larger ICAstd was associated with less presence of lacunes (odds ratio: 0.418, adjusted for age and sex). Higher gray matter CBF (β = 0.154) and larger ICAstd (β = 0.136) were associated with better MoCA scores (adjusted for age, sex, and education). Prolonged blood transit time, decreased ICAstd, and diminished CBF were associated with vascular dysfunction and cognitive impairment. They may serve as vascular functional markers in future studies. 3 TECHNICAL EFFICACY: Stage 3.

Decentralized Intermittent Feedback Adaptive Control of Non-Triangular Nonlinear Time-Varying Systems

This paper investigates the decentralized stabilization problem for a class of interconnected systems in the presence of non-triangular structural uncertainties and time-varying parameters, where each subsystem exchanges information only with its neighbors and only intermittent (rather than continuous) states and input are to be utilized. Thus far to our best knowledge, no solution exists priori to this work, despite its high prevalence in practice. Two globally decentralized adaptive control schemes are presented based on the backstepping technique, the first one is developed in a continuous fashion by combining the philosophy of the modified congelation of variables based approach with the special treatment of non-triangular structural uncertainties, which avoids the derivative of time-varying parameters and eliminates the limitation of the triangular condition, thus largely broadens the scope of application. By making use of the important property that the partial derivatives of the constructed virtual controllers in each subsystem are all constants, the second scheme is developed through directly replacing the states in the preceding scheme with the triggered ones. Consequently, the non-differentiability issue of the virtual controllers stemming from intermittent state feedback is completely obviated. The internal signals under both schemes are rigorously shown to be globally uniformly bounded with the aid of several novel lemmas, while the stabilization performance can be enhanced by appropriately adjusting design parameters. Moreover, the inter-event intervals are ensured to be lower-bounded by a positive constant. Finally, numerical simulation verifies the benefits and efficiency of the proposed method.