Search Results (3,051)

Reconfigurable radio-frequency (RF) front ends employ N-path filters to achieve digitally tunable frequency selectivity, high linearity, and low static power. However, their linear periodically time-varying (LPTV) operation complicates analysis because an input tone is translated to multiple output harmonics. This tutorial review synthesizes the principal methods for analyzing N-path filters, comparing continuous-time window function analysis, discrete-time ordinary differential equation (ODE) modeling, and adjoint network methods. We evaluate and compare their underlying assumptions, outputs, and computational burdens. Additionally, we present an educational time-domain interpretation based on orthogonal sine/cosine excitation. This viewpoint connects capacitor averaging and path-to-path phase cancellation with harmonic transfer functions (HTFs). Rather than replacing rigorous HTF formulations, this interpretation provides a physically intuitive explanation for the fundamental coefficient $H_0\left(f\right)$ and the gain-null condition at $f_{\mathrm{in}}=kN{f}_s$. The numerical integration of the switched-RC equations serves as a consistency check. For a four-path example with $\Gamma =\tau /\left(RC\right)=0.02$, the numerical values of $|H_0\left(f_s\right)|$ and $|H_0\left(2f_s\right)|$ differ from the intuitive limits by less than $0.001$ dB. The residual responses at $4f_s$ and $8f_s$ are $-49.95$ dB and $-55.97$ dB, respectively. Finally, we extend the orthogonal-excitation relationship to extract higher-order HTFs. This tutorial synthesis clarifies how these established analytical methods relate and guides selection for specific applications. Full article

Megakaryocytes (MKs) and platelets are increasingly recognized as active regulators of the bone marrow (BM) microenvironment rather than passive effectors of thrombopoiesis and hemostasis. Recent single-cell and lineage-tracing studies have established that megakaryopoiesis generates functionally heterogeneous populations, including immune-biased and niche-supporting subsets that shape hematopoietic stem cell (HSC) behavior, inflammatory tone, and vascular homeostasis. In leukemia, these regulatory circuits are systematically rewired to establish a marrow niche that suppresses normal hematopoiesis while sustaining leukemic stem cell (LSC) fitness through cytokine gradients, stromal remodeling, and direct cell-to-cell communication. In this focused review, we propose that the immune MK (iMK)–platelet axis is a central driver of leukemic niche remodeling. We discuss how iMK states arise under leukemic pressure, how MK heterogeneity encodes distinct niche instructions, and how platelet-derived extracellular vesicles (EVs) distribute inflammatory signals across the marrow and systemic circulation. Within this framework, we position mitochondrial stress outputs—such as reactive oxygen species (mtROS), mitochondrial DNA (mtDNA) release, metabolic rewiring, and mitochondria-containing EV secretion—not as isolated phenomena, but as mechanistic amplifiers embedded within the broader inflammatory and niche-regulatory programs of MKs and platelets. We further highlight preleukemic inflammatory states as an underappreciated entry point for therapeutic intervention, and propose three clinically actionable axes: inflammatory niche interruption, mitochondrial stress modulation, and platelet–leukemia communication blockade. This framework aligns with emerging concepts in MK heterogeneity, innate immune sensing, endothelial remodeling, and preleukemic signaling, and positions the MK–platelet axis as a promising therapeutic framework in leukemia-associated niche remodeling. Full article

Within the Diagnostic Criteria for Temporomandibular Disorders, masticatory myalgia is framed around muscle hyperactivity, yet a recognizable subgroup shows the opposite profile—low muscle tone, fatigue, masticatory pain, and a persistent sense that the bite no longer fits, without structural dental change—and responds poorly to conventional conservative care. We introduce G-SCORE (Gum-chewing-mediated Sensorimotor Calibration of Occlusion through Rhythmic Exercise), a proprioceptive recalibration strategy delivered as a bilateral gum-chewing (BGC) protocol: two equal halves of one sugar-free gum chewed simultaneously and symmetrically on both posterior segments in short, patient-titrated sessions, delivering balanced, rhythmic, low-load input to the trigeminal sensorimotor system. In a retrospective series of 41 patients, we characterized within-subject changes in pain, mandibular mobility, and occlusal parameters. Masticatory pain fell from 5.0 ± 2.9 to 0.7 ± 0.9 (0–10; n = 27; p < 0.001; r = 0.87), with 85% achieving a ≥2-point reduction. Occluding tooth positions and mouth opening also recovered; in an anterior open-bite subgroup, overbite improved (n = 6; p = 0.031). The observed changes were dominated by pain relief and restored bilateral occlusal contact rather than by raw force—a pattern more compatible with sensorimotor recalibration than with muscle hypertrophy. This low-cost, non-invasive technique may help selected patients avoid irreversible occlusal treatment. Full article

Colorism is a skin-tone stratification system that privileges proximity to Eurocentric features and disadvantages darker skin tones and Afrocentric features. Although colorism is increasingly recognized as a gendered social determinant of health, its role in shaping sexual health among Black and Brown girls and women remains understudied. This rapid review synthesized peer-reviewed empirical evidence on the relationship between colorism, skin tone, and sexual health outcomes among girls and women. Searches were conducted in PsycINFO and PubMed between April and May 2026. After removing duplicates, 114 unique records were screened in Covidence, yielding eight eligible studies. Five studies were quantitative, two were qualitative, and one was mixed methods. The included studies were synthesized narratively due to heterogeneity in study design, measurement, and outcomes. Findings suggest that colorism is associated with sexual risk behaviors, sexual agency and desirability, sexual development, and HIV-related sexual functioning. Across studies, colorism appeared to shape sexual health through three interrelated pathways: internalization and self-esteem, colorist desirability hierarchies that influence sexual agency and relationship dynamics, and differential sexualization experiences that shape girls’ sexual development and vulnerability across the life course. One study also highlighted parental support as a potential protective factor. Collectively, the findings position colorism as a potentially important social determinant of sexual health and underscore the need to integrate colorism into future sexual health research, prevention, and intervention frameworks. Full article

Proteinase-activated receptor-2 (PAR2) regulates cardiac pressure and vascular function through context-dependent mechanisms that integrate G protein-coupled receptor signalling. We investigated the baseline cardiovascular phenotype of PAR2-deficient (PAR2^−/−) mice and the acute in vivo effects of the PAR2 agonist trans-cinnamoyl-Leu-Ile-Gly-Arg-Leu-Orn-amide (tcLIGRLO). Left ventricular pressure–volume (PV) analysis revealed that PAR2^−/− mice had elevated systolic and diastolic pressures with reduced end-diastolic volumes and increased ejection fraction while maintaining stroke volume and cardiac output. Thus, PAR2 deficiency produces a pressure-dominant cardiovascular state with increased mechanical work and preserved global function. In WT mice, tcLIGRLO dose-dependently reduced cardiac pressure generation, contractility, relaxation kinetics, and stroke work, whereas these effects were absent in PAR2^−/− mice, indicating PAR2-dependent cardiac regulation. Despite these changes, global cardiac output remained largely preserved despite modest reductions in heart rate. In contrast, tcLIGRLO elicited strain-dependent vascular responses, including altered effective aortic elastance and reduced carotid blood flow in PAR2^−/− mice. Ex vivo experiments showed that tcLIGRLO-induced contraction in PAR2^−/− arteries required Gq-dependent signalling in this experimental context. These findings identify PAR2 as a context-dependent regulator of cardiac pressure and vascular tone, in which PAR2-dependent cardiac effects and PAR2-independent, Gq-mediated vascular responses reflect distinct but interacting signalling mechanisms. Full article

The firing of traditional gray pottery relies on complex physicochemical reactions governing its color, dimensional accuracy, and structural stability. Unclear kiln-transformation mechanisms restrict standardized and digital production of this Chinese intangible cultural heritage. Herein, direct ink writing (DIW) was used to fabricate Hejin gray pottery green bodies from local ternary raw materials. Thermodynamic calculations, TG–DTG/DSC, XRD, XRF, and atmosphere-controlled firing tests were combined to reveal coupled phase evolution and reduction color-forming mechanisms during sintering. Two interrelated kiln-transformation processes were identified. First, sequential mineral reconstruction occurs at four critical temperatures: free water loss at 119.8 °C, two-stage dehydroxylation of hydrous silicates at 270.5 °C and 767.9 °C, and CaCO₃ decomposition at 547.9 °C. Uneven shrinkage and gas release at these temperatures induce cracking, blistering, and deformation of printed bodies. Micron-sized CaCO₃ (equivalent radius ≈ 1.31 μm) exhibits high surface energy and significantly reduces its decomposition temperature, consistent with experimental observations. Second, reducing atmospheres trigger competitive phase formation. Distinct from the conventional Fe₂O₃ → Fe₃O₄ → FeO reduction pathway, Fe oxides preferentially react with abundant Al₂O₃ to form thermodynamically stable FeAl₂O₄ spinel, yielding uniform celadon-gray tones. The final color is nearly independent of 20–90 vol% CO, and air-isolated cooling below 600 °C is mandatory to prevent secondary oxidation and reddening. This work establishes a thermodynamic framework for DIW-printed Hejin gray pottery kiln transformation, clarifies microscale defect and color-evolution mechanisms, and offers theoretical guidance for atmosphere-controlled firing and digital mass production of heritage ceramics. Full article

In recent years, the food industry has increasingly focused on reintegrating nutrient- and phytochemical-rich processing by-products into high-consumption food matrixes. Aligned with this trend, our study investigated melon peel powder (MPP) as a value-added, upcycled ingredient in biscuit formulations with 0, 5, 10, 15, and 20% (w/w) MPP as a partial replacement for wheat flour (WF). The effects of this substitution on nutritional profile, colour, physical properties, total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), structural characteristics, and post-baking retention were evaluated. MPP exhibited higher TPC (1531.76 mg GAE/100 g DM), TFC (681.42 mg QE/100 g DM), FRAP (104.37 µM Fe²⁺/g DM) and DPPH (125.01 µM TE/g DM) than WF. Its incorporation improved nutritional quality by increasing dietary fiber and ash, while reducing available carbohydrates and energy value. Substantial enhancements were observed, with up to 6.72- and 6.93-fold increases in FRAP and DPPH, alongside 3.82- and 3.92-fold increases in TPC and TFC at the highest substitution level. Although baking reduced these levels, retention remained at 57–62% (TPC), 55–59% (TFC), 60–65% (FRAP), and 63–70% (DPPH), indicating partial thermal stability and possible contribution of heat-induced antioxidant compounds. MPP addition also affected technological properties, increasing baking yield and spread ratio while decreasing lightness (L*) and increasing yellowness (b*) and browning index (BI), resulting in yellow-brown tones. Fourier-transform infrared spectroscopy (FTIR) and wide-angle X-ray scattering (WAXS) analyses confirmed structural compatibility between WF and MPP, evidenced by the absence of new functional groups, preservation of the A-type crystalline structure of wheat starch without polymorphic transitions, and no indication of phase separation, whereas baking promoted starch gelatinization and integration of fibrous and pectic components. These findings support a potential valorisation pathway for melon by-products through their conversion into a value-added ingredient for biscuit production. Full article

Strychnine-sensitive glycine receptors (GlyRs) are pentameric ligand-gated chloride channels that mediate fast inhibitory neurotransmission in the central nervous system (CNS), with high expression in the spinal cord, brainstem, cerebellum, and retina. Beyond traditional postsynaptic phasic inhibition, emerging evidence highlights the importance of extrasynaptic GlyRs—expressed in both neuronal and non-neuronal cells—in mediating tonic inhibition by sensing ambient glycine levels, including in the forebrain. These non-synaptic receptors display high agonist affinity, unique subunit compositions, and distinct pharmacodynamics. Notably, recent studies have begun to implicate aberrant GlyR signaling in Alzheimer’s disease (AD) pathology; however, its functional role in this specific neurodegenerative context remains only poorly understood. This review synthesizes the molecular properties and functional significance of these diverse GlyR populations, emphasizing their involvement in calcium signaling, inhibitory tone, and neural circuit modulation, while critically evaluating their emerging therapeutic potential in AD. Full article

Acute kidney injury (AKI) is characterized by a rapid decline or sudden loss of renal function over hours to days. Pathophysiological triggers such as renal ischemia–reperfusion (IR) injury and the accumulation of uremic toxins (UTs), notably indoxyl sulfate (IS), can initiate AKI and affect vascular beds distant from the ischemic site, like the aorta. In this context, purinergic signaling becomes relevant, since its components regulate vascular tone and inflammatory responses. This study aimed to evaluate the impact of AKI induced by IR with or without IS administration on purinergic signaling in the aorta of mice. Renal ischemia was induced by the occlusion of the left renal pedicle for 60 min, followed by reperfusion for 8 days (IR 8) or 15 days (IR 15). Some animals were also treated with saline solution or IS for 15 days. The IR15 group exhibited increased plasma IS concentrations and upregulated adenosine receptor gene expression. Furthermore, in the IR+IS group, there was increased expression of A1, A2a, NTPDase 1, and 2. This shift toward an adenosine-enriched signaling environment may represent a key mechanism linking renal injury to systemic vascular inflammation. Full article

Serotonin (5-hydroxytryptamine, 5-HT) is a vasoactive amine and important regulator of vascular tone. Aberrant serotonergic activity contributes to vascular pathology in multiple cardiovascular disease states, including hypertension, diabetes, metabolic syndrome and chronic myocardial ischemia. Serotonin also plays a vital role in postoperative vascular dysfunction after cardioplegic arrest with cardiopulmonary bypass (CP/CPB). Perioperative microvascular dysfunction following CP/CPB manifests as an increased propensity for vasospasm or vasoplegia, with different effects in different tissue beds (coronary, skeletal muscle, pulmonary and systemic microcirculations). Given the importance of serotonin as a modulator of vasogenic responses, we present a selected narrative survey of the current literature concerning the effects of altered serotonergic activity on vascular dysfunction in the context of CP/CPB and other cardiometabolic diseases. This review begins with a discussion of normal serotonin biology and signaling pathways, then moves into disease-specific discussions covering five major areas of focus: metabolic syndrome, diabetes, hypertension, myocardial ischemia and CP/CPB. Full article

The tree shrew (Tupaia belangeri) is increasingly recognized as an important experimental model for studying human diseases due to its close phylogenetic relationship with humans. Because the basilar artery’s response to endogenous vasoactive mediators varies among species, we investigated the effects of vasoactive substances on isolated tupaia basilar arteries to determine whether this species is suitable as a human model. 5-Hydroxytryptamine (5-HT) and histamine (His) induced contraction, while bradykinin (BK) and acetylcholine (ACh) produced concentration-dependent relaxation. Pharmacological analysis revealed that contractions triggered by 5-HT were regulated through 5-H₁ and 5-HT₂ receptors, while His-induced responses were mediated by H₁ receptors. BK-induced relaxation was inhibited by the B₂ antagonist HOE140 and N^ω-nitro-L-arginine (L-NA), but not by B₁ antagonists or indomethacin, suggesting a B₂ receptor-mediated nitric oxide (NO) pathway. ACh-induced relaxation was markedly reduced in the presence of L-NA and the M₃ antagonist pFHHSiD, indicating M₃ receptor-mediated NO release. At basal tone, L-NA evoked a contractile response, while indomethacin led to relaxation, suggesting basal regulation by NO and prostanoids. These findings demonstrate that 5-HT₁/5-HT₂ and H₁ receptors mediate contraction, while B₂ and M₃ receptors mediate relaxation in the tupaia basilar artery. This study highlights species-specific cerebrovascular regulation and supports the tupaia as a relevant model for investigating human cerebrovascular physiology and pathophysiology. Full article

The vaginal microbiome is often interpreted through static taxonomic patterns. Yet microbial composition alone does not explain why some communities resist perturbation, recover after disruption, or transition toward dysbiosis. This narrative review synthesizes evidence that vaginal microbiome stability is shaped by endocrine phase, epithelial substrate availability, microbial functional capacity, mucosal tone and candidate host modifiers. High-estrogen states, particularly pregnancy, are associated with epithelial maturation, glycogen accumulation, low vaginal pH, and Lactobacillus-dominant communities, whereas postpartum, lactational, menopausal, and other hypoestrogenic states are associated with reduced epithelial support and increased vulnerability to diverse anaerobe-rich configurations. We review the linking of the estrogen–glycogen–Lactobacillus axis, focusing on microbial functions involved in glycogen degradation, lactate production and biofilm persistence, and host pathways that may modify mucosal responsiveness. Direct human genotype-to-vaginal-microbiome stability evidence remains limited; therefore, host genetic features are treated as candidate modifiers rather than validated clinical predictors. We propose a conceptual multi-omic hierarchy for organizing endocrine, epithelial, microbial, immune, temporal, and candidate host-modifier domains relevant to vaginal microbiome resilience. This framework is hypothesis-generating and requires longitudinal, phase-resolved human validation before quantitative prediction or clinical application. Full article

The mammalian gut microbiome functions as a metabolically active immunological organ and has co-evolved with its host to maintain systemic homeostasis. This review integrates current evidence on the molecular mechanisms governing bidirectional microbiota–immune communication, emphasizing evolutionary conservation, receptor-mediated signaling, and translational implications. Microbial structural ligands and metabolites—including short-chain fatty acids, bile-acid derivatives, and tryptophan catabolites—engage host receptors such as G-protein-coupled receptors, FXR/TGR5, and the aryl hydrocarbon receptor (AhR), thereby regulating epithelial barrier integrity, regulatory T-cell differentiation, Th17 polarization, mucosal IgA production, and systemic immune tone. Riboflavin-derived metabolites presented via major histocompatibility complex class-I-related molecule (MR1) further shape mucosal-associated invariant T-cell development (MAIT), illustrating metabolite-driven immune system programming. Dysbiosis induced by antibiotics, dietary perturbation, or aging disrupts these molecular networks, promoting chronic inflammatory, metabolic, autoimmune, and neuroimmune disorders. Comparative analyses across mammalian systems underscore conserved pathways of host–microbe coadaptation and immune education. Therapeutically, microbiota-modulating strategies—including probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), postbiotics, and IgY-based passive immunotherapy—aim to restore immunometabolic signaling. Emerging in vitro and in silico platforms further provide mechanistic precision while supporting ethically aligned translational research. Collectively, these insights position microbiota-derived molecular signaling as a central determinant of adaptive immune architecture and a targetable axis in precision immunotherapy. Full article

Ultrasound is safe, portable, and relatively low cost, and robotic ultrasound research is expanding across many diagnostic applications. Within this context, abdominal aortic aneurysm (AAA) screening remains comparatively unexplored, with few systems reporting end-to-end autonomous scanning and clinician-validated evaluation in volunteers. We present a conditionally autonomous (Level-3) robotic ultrasound system in which the operator defines the region of interest and confirms the target force band, after which the robot performs surface-constrained abdominal sweeps under force control and automatically selects diagnostic frames and estimates aortic diameter without further manual interaction during scanning. The system combines RGB-depth-based patient-to-robot registration, hybrid position–force control with a low-cost force sensor, and a post-acquisition image-analysis pipeline comprising rule-based aorta localisation, a composite image quality assessment (IQA) metric, and a transfer-learned U-Net segmentation baseline. In a feasibility study on ten healthy volunteers spanning BMI 18.6–33 and diverse sex and skin-tone profiles, the robot maintained stable contact within the target force band in all sessions and produced aortic images rated diagnostically acceptable by clinicians in all participants. Automated diameter measurements showed a mean absolute difference of 1.45 mm relative to clinician reference values, with 9/10 cases within 3 mm and all within the 5 mm screening criterion. Volunteer questionnaires indicated high levels of comfort and trust in the system. These results demonstrate the feasibility of operator-supervised, force-aware robotic AAA scanning and highlight the potential of low-cost robotic ultrasound for wider automated vascular imaging. Full article

Biofilm-associated infections caused by Staphylococcus aureus are highly resistant to antimicrobial treatments. Low-intensity electric fields have shown promise as an antibiofilm strategy; however, the role of frequency remains poorly understood. In this study, mature S. aureus biofilms were exposed to low-intensity alternating electric fields (12.5 mV/cm) across broadband (10 Hz–10 MHz) frequency range and band-limited sub-ranges, as well as to selected single-tone frequencies within the interval 1–100 kHz. Antibiofilm activity was assessed in terms of cell culturability (CFU/mL) and biofilm biomass. A significant frequency-dependent effect was observed (p < 0.001), with maximal activity observed only at specific frequencies within the range 1–100 kHz, whereas other frequencies were ineffective. These findings demonstrate that the electrical antibiofilm effect is characterized by a frequency selective response, which is similar to a band-pass filter with a nearly flat shape inside the band-pass range and strongly attenuated effects outside such a band. This frequency-selective response supports the hypothesis of a biophysical mechanism involving membrane and matrix interactions and highlights the potential for developing targeted, frequency-optimized electroceutical strategies. Full article