Search Results (1,135)

In addition to binding to and regulating over 400 different proteins, calmodulin (CaM) also binds to lipids. Binding occurs to the prenylated tails of various small GTPases, to specific lipids in biological membranes and to free lipids in the cytoplasm. Here, CaM binding to Rac1, RalA, and KRAS4b is covered, emphasizing its importance in protein translocation from the cell membrane to the cytosol and its resultant impact on cell signaling. Binding phosphatidylserine and phosphatidylethanolamine in membranes not only leads to the tethering of CaM, but also to the disruption of lipid bilayers. Binding to sphingolipids also occurs, an event that acts as a competitive inhibitor of CaM function. The mechanism through which CaM binds to lipids is also examined. In total, the current state of affairs regarding calcium-dependent CaM–lipid binding is reviewed, including potential therapeutic uses, setting the stage for future work on this important biological event. Full article

Spinning tethered satellite systems represent a promising advancement in the design of spaceborne architectures for Earth and planetary observation. Leveraging the unique advantages of tether technology, such as mass efficiency in deploying large structures and fuel-free formation control, this study explores the feasibility and performance potential of CubeSat-scale spinning tethered formations. These systems consist of multiple spacecrafts connected by a tether, enabling easy dynamic adjustment of inter-satellite spacing and rotational velocity through conservation of angular momentum. Such flexibility facilitates precise, stable formations suitable for a range of remote sensing applications. In this paper, the authors present an overview of the dynamical modelling, deployment strategy, and operational advantages of spinning tether systems, focusing in particular on some key use cases: Earth, Moon and Mars surface observation. Three representative sensing modalities are analysed: (1) stereo imaging, where tethered platforms allow synchronized capture with tuneable baselines; (2) distributed radar sounding, which benefits from mechanically stabilized, spatially dispersed sensors to enhance resolution; and (3) Synthetic Aperture Radar (SAR) interferometry, where tether-induced baseline control improves accuracy and simplifies phase unwrapping. A performance assessment is provided for multiple orbital configurations around the Earth and the Moon. The results demonstrate that, while some issues still need to be explored in more detail, spinning tethered systems can offer competitive or superior observational performance in different mission scenarios compared to current technologies. The main challenges posed by this kind of architecture are discussed, alongside future research directions and development prospects. Full article

Mitochondria–endoplasmic reticulum contacts (MERCs) are physical structures formed between mitochondria and the endoplasmic reticulum (ER) through various tethering proteins, playing crucial roles in multiple physiological processes, including Ca²⁺ and lipid exchange between the ER and mitochondria, regulation of mitochondrial morphology and dynamics (fusion and fission), as well as the induction of autophagy and apoptosis. Mitofusin 2 (MFN2), a key mitochondrial fusion protein, has been identified as an essential structural component of MERCs. Our research demonstrates that 16:8 circadian intermittent fasting (CIF) leads to enhanced mitochondrial fusion. The upregulation of MFN2 reinforces MERC stability, thereby facilitating efficient Ca²⁺ transfer between the ER and mitochondria. This process sustains the activity of mitochondrial oxidative phosphorylation (OXPHOS) enzymes, elevates mitochondrial oxygen utilization efficiency, and ultimately augments ATP production. Consequently, these adaptations enhance cardiomyocyte tolerance to hypoxic conditions. This study elucidates a novel mechanism by which MERCs regulate cellular hypoxia resistance and proposes a potential therapeutic strategy for improving acute hypoxia tolerance through the modulation of Ca²⁺ transport at MERCs. Full article

Inspired by observations of manta ray gliding, this study designed and evaluated a more biologically accurate pectoral fin bending model. We assessed its hydrodynamic performance using six-degrees-of-freedom (6-DoF) Computational Fluid Dynamics (CFD) simulations, which were validated by tethered water tunnel experiments. Key findings reveal that symmetric bending significantly impacts longitudinal stability, increasing the pitch angle to nearly twice that of the flat-wing model (80° model) but compromising gliding efficiency. During this symmetric motion, the lift-to-drag ratio (K) minimum point is significantly delayed as the bending angle increases, following a negative quadratic trend. Conversely, asymmetric bending triggers a sharp 3.5-fold increase in the roll angle (80° vs. 30° model) and produces significant lateral displacement. Importantly, “roll-induced yaw” was confirmed as the dominant mechanism for lateral control, contributing up to 88.5% of the lateral force in the 80° model, despite minimal changes in the yaw angle. These findings reveal the intrinsic trade-offs between fin deformation, gliding efficiency, and attitude control, providing a theoretical basis for active configuration optimization and control strategies for bionic gliders. Full article

The maintenance of endoplasmic reticulum (ER) Ca²⁺ homeostasis is intrinsically linked to the fidelity of protein folding, forming a functional tether that, when disrupted, triggers the Unfolded Protein Response (UPR). This bidirectional axis serves as a critical rheostat for cellular viability, yet its chronic dysregulation underpins the molecular etiology of numerous pathologies, including neurodegeneration, heart failure, and malignant transformation. This review provides a comprehensive interrogation of the Ca²⁺-ER Stress–UPR network, delineating how primary stress sensors—PERK, IRE1alpha, and ATF6—engage in complex feedback loops that either reinstate equilibrium or commit the cell to apoptosis. We specifically examine the PERK-CHOP-SERCA2b inhibitory circuit as a central driver of persistent Ca²⁺ depletion and discuss the role of Mitochondria-Associated Membranes (MAMs) in governing lethal Ca²⁺ transfer. Notably, we move beyond the classical paradigm of CHOP as a terminal apoptotic executioner, incorporating emerging evidence of its context-dependent adaptive functions. By synthesizing mechanistic insights across diverse disease models, this work highlights the transition from adaptive to maladaptive UPR as a universal pathological checkpoint. Ultimately, we evaluate the therapeutic potential of ‘axis-targeted’ interventions, such as SERCA activators and selective UPR modulators, aimed at resolving the underlying Ca²⁺ signaling defects in ER stress-related disorders. Full article

Chronic wounds and implanted medical devices remain highly vulnerable to biofilm-associated infections, which resist conventional antibiotics and immune clearance. Synthetic antimicrobial peptides (AMPs) have emerged as promising alternatives, offering tunable sequences, short lengths for cost-effective synthesis, and functional modifications that enhance stability and antibiofilm potency. Hydrogels provide an optimal delivery matrix by enabling localized AMP release, maintaining a moist wound environment, and supporting stimuli-responsive or sustained therapeutic action. This review highlights recent advances in peptide engineering strategies—including rational sequence design, chemical modifications, and self-assembling nanostructures—alongside hydrogel integration approaches ranging from physical entrapment to covalent tethering and infection-triggered release systems. Mechanistic insights into antibiofilm activity are discussed, supported by in vitro, ex vivo, and in vivo evaluation models. Beyond antimicrobial efficacy, multifunctional AMP–hydrogel systems can deliver complementary benefits such as hemostasis, anti-inflammation, or enzymatic biofilm dispersal, further accelerating tissue repair. Despite significant progress, translational challenges remain, including peptide stability, manufacturing costs, regulatory hurdles, and host safety. Future directions point toward AI-driven peptide design, programmable hydrogels, and point-of-care integration to realize safe, effective, and multifunctional AMP–hydrogel therapies for chronic wound management and biofilm eradication. Full article

The epigenome and nuclear architectural mechanisms that regulate neuronal activity-induced transcriptional responses in cortical neurons remain incompletely understood. Previously, we have shown that the chromatin organizer SATB2 and the inner nuclear membrane protein LEMD2 form a chromatin tether at the nuclear lamina, and that activity-induced transcription is impaired in both Satb2 and Lemd2 loss-of-function models. Interaction of SATB2 and LEMD2 with subunits of the ESCRT-III complex indicates that the ESCRT-III complex could serve as an activity-dependent, dynamic component of this tether. Here, we study the activity-dependent subcellular localization and function of the ESCRT-III components CHMP7 and CHMP4B in primary cortical neurons. We find that increased neuronal activity correlates with the accumulation of co-localized CHMP7 and CHMP4B foci at the nuclear envelope. shRNA-mediated Chmp7 knockdown causes a reduction in the expression of activity-regulated genes and genes with highly specialized functions in synaptic organization and trans-synaptic signaling. Furthermore, the observed similarity in the global transcriptome responses in Satb2, Lemd2, and Chmp7 loss-of-function models points toward a previously unrecognized role of the SATB2–LEMD2–CHMP7 tether in linking chromatin architecture and nuclear envelope plasticity to activity-dependent gene regulation. Full article

The cycloaddition reaction is one of the most common reactions in organic chemistry. It has been applied in various fields. Herein, we focus on the application of cycloaddition reactions in investigating biological molecules and materials using magnetic resonance techniques. To facilitate magnetic resonance studies such as electron paramagnetic resonance (EPR) spectroscopy and paramagnetic nuclear magnetic resonance (NMR) spectroscopy, there is often a requirement to attach spin labels and paramagnetic tags to the system of interest. The cycloaddition reaction is one of the ways to tether these spin labels and paramagnetic tags. In this review, we highlight the applications of various cycloaddition reactions such as the Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction, the strain-promoted azide–alkyne cycloaddition (SPAAC) reaction and the Diels–Alder reaction in the interdisciplinary field of magnetic resonance studies of biomolecules, including proteins, nucleic acids, carbohydrates, lipids and glycans, as well as materials. Full article

A new fluorescence detection method for PO₄³⁻ was developed through the in situ synthesis of cadmium sulfide quantum dots (CdS QDs). Without PO₄³⁻, the CdS QDs could not be effectively formed by only the S²⁻ and Cd²⁺ in the solution. As a stabilizer, PO₄³⁻ is an essential component to regulate the in situ synthesis of CdS QDs. The fluorescence intensity following the addition of different concentrations of PO₄³⁻ was monitored for quantification. Under optimum conditions, the fluorescence intensity shows a linear relationship with concentrations ranging from 3.0 to 300 µM, and a detection limit of 2.9 µM. This assay was successfully employed to assess PO₄³⁻ in tap water and wastewater. Compared with traditional methods, which require pre-synthesizing QDs and tethering them with recognition elements to achieve sample detection, the proposed method is simpler and quicker. It takes less than 5 min to complete PO₄³⁻ detection. Full article

This computational study examined how variations in the seatback angle of two generic child restraint systems (CRSs) affect spinal loading in young occupants (1.5 YO and 3 YO) during frontal impacts, performed according to the specifications included in UNECE R129. CRS seatback angle dictates torso recline, which in turn influences head, chest, and spine kinematics and loading. While manufacturers typically recommend 30–45° for rear-facing CRSs and an upright position for forward-facing CRSs, little is known about the biomechanical implications of deviating from these guidelines. Using PIPER human body models representing a 1.5-year-old in a rear-facing CRS and a 3-year-old in a forward-facing CRS, simulations were performed under UN-R129 frontal impact conditions. The seatbacks were rotated 5° and 10° more upright or reclined relative to the nominal angle, with occupants restrained by a five-point harness and CRSs secured with ISOFIX, top tether, or three-point belt. The results showed that reclined configurations generally increased the predictions of spinal loading (forces and/or moments) given by the PIPER model, while nominal or more upright angles reduced loads, particularly in the lumbar spine of the 3-year-old model. Overall, the study highlights how computational tools can guide CRS design improvements to optimize spinal protection and enhance child safety beyond current regulatory requirements. Full article

Remotely operated underwater vehicles (ROUVs) have been attracting more attention lately as they are considered to be operationally versatile, capable of real-time communication, and can be fitted with various sensor payloads for environmental monitoring purposes. This study presents the design, development, and field validation of a sensor-enhanced ROUV platform tailored for environmental monitoring and aquaculture applications. The vehicle is equipped with a modular set of sensors for temperature, pH, dissolved oxygen (DO), and electrical conductivity (EC) along with separate signal-conditioning circuits for each sensor and real-time data acquisition from tethered architecture. The general system concept is modularity, reproducibility, and robustness in a marine environment. In situ measurements were performed at an active aquaculture site in the North Aegean Sea throughout several seasons during 2025. Using this system, depth-resolved measurements were obtained with sensor accuracies of ±0.1 °C (temperature), ±0.05 pH units, ±0.05 mg/L (dissolved oxygen), and ±2% (electrical conductivity). The following sections describe the development and aquaculture testing of the platform, which yielded stable and repeatable operation in real conditions. Full article

The interface between synthetic materials and biological systems is a critical determinant of performance in medical devices and biosensors. This review examines the evolution of biointerface science through the lens of self-assembled monolayers (SAMs) of thiols on gold, a model system that offers atomic-level control over surface chemistry. We trace the field from the foundational structural characterization to the establishment of empirical design rules for bio-inertness. While early theoretical models attributed protein resistance to steric repulsion forces in polymer brushes, contemporary understanding has shifted toward the “water barrier” hypothesis, which posits that tightly bound interfacial water prevents direct biomolecular contact. We highlight recent studies that extend these concepts into “realistic” crowded biological environments. Their work reveals that fouling surfaces in crowded media generate a “viscous interphase layer” (VIL) that extends tens of nanometers into solution, whereas zwitterionic surfaces maintain a robust hydration shell that prevents this accumulation. Furthermore, this hydration barrier is shown to fundamentally alter bacterial mechanics, forcing microorganisms into a reversible, tethered “hovering” state at a significant biological interaction distance (>100 nm) from the surface, effectively precluding biofilm nucleation. These insights underscore that the future of antifouling material design lies in the precise engineering of interfacial hydration structures. Full article

Offshore wind-farm performance remains constrained by persistent wake deficits and turbulence that compound across intra-farm, intra-cluster, and inter-cluster scales, particularly under atmospheric neutral–stable stratification. A concept is advanced whereby offshore wind-farm yield may be augmented by pairing conventional horizontal-axis wind turbines (HAWTs) with lighter-than-air parafoil systems that entrain higher-momentum air and re-energise wakes, complementing yaw/induction-based wake control and enabling higher array energy density. A concise synthesis of wake physics and associated challenges motivates opportunities for active momentum re-injection, while a review of kite technologies frames design choices for lift generation and spatial keeping. Stability and control, spanning static and dynamic behaviours, tether dynamics, and response to extreme meteorological conditions, are identified as key challenges. System-integration pathways are outlined, including alignment and mounting options relative to turbine rows and prevailing shear. A staged validation programme is proposed, combining high-fidelity numerical simulation with wave-tank testing of coupled mooring–tether dynamics and wind-tunnel experiments on scaled arrays. Evaluation metrics emphasise net energy gain, fatigue loading, availability, and Levelized Cost of Energy (LCOE). The paper concludes with research directions and recommendations to guide standards and investment, and with a quantitative assessment of the techno-economic significance of kite–HAWT integration at scale. Full article

This study investigated the impact of post-activation performance enhancement (PAPE) on the parameters of the 3 min all-out test (3MT) in non-motorized tethered running, applying the concept of complex networks for integrative analysis. Ten recreational runners underwent anthropometric assessments, a one-repetition maximum test (1RM), a running ramp test, and 3MT trials under both PAPE and CONTROL conditions across five separate sessions. The conditioning activity consisted of two sets of six back squats at 60% 1RM. For each scenario, complex network graphs were constructed and analyzed using Degree, Eigenvector, PageRank, and Betweenness centrality metrics. In the PAPE condition, anthropometric parameters and parameters related to aerobic efficiency exhibited greater centrality, ranking among the top five nodes. Paired Student’s t-tests (p ≤ 0.05) revealed significant differences between conditions for end power (EP-W) (CONTROL: 407.83 ± 119.30 vs. PAPE: 539.33 ± 177.10 (effect size d = −0.84)) and end power relativized by body mass (rEP-W·kg⁻¹) (CONTROL: 5.38 ± 1.70 vs. PAPE: 6.91 ± 2.00 (effect size d = −0.76)), as well as for the absolute and relative values of peak output power, mean output power, peak force, and mean force. These findings suggest that PAPE alters the configuration of complex networks, increasing network density, and may enhance neuromuscular function and running economy. Moreover, PAPE appears to modulate both aerobic and anaerobic contributions to performance. These results highlight the importance of network-based approaches for advancing exercise science and providing individualized strategies for training and performance optimization. Full article

BST2 has emerged as a multifunctional molecule that bridges antiviral defense, membrane architecture, and tumor immunity. Originally characterized as an interferon-inducible restriction factor that tethers virions to the plasma membrane, BST2 is now recognized as an oncogenic driver and immunoregulatory hub in diverse malignancies. In cancer, BST2 expression is frequently upregulated through promoter hypomethylation and transcriptional activation. Functionally, BST2 promotes proliferation, epithelial–mesenchymal transition, anoikis resistance, and chemoresistance, whereas its loss sensitizes tumor cells to proteotoxic and metabolic stresses. Beyond tumor cells, BST2 modulates the tumor microenvironment by promoting M2 macrophage infiltration, dendritic cell exhaustion, and natural killer (NK)-cell resistance, thereby contributing to immune evasion. Elevated BST2 expression correlates with poor prognosis in glioblastoma, breast, nasopharyngeal, and pancreatic cancers, and it serves as a circulating biomarker within small extracellular vesicles. In conclusion, BST2 is a dual-function molecule that integrates oncogenic signaling and immune regulation, making it an attractive diagnostic and therapeutic target for hematological and solid tumors. Full article