Search Results (2,903)

Tomato brown rugose fruit virus (ToBRFV) has been causing severe agricultural damage worldwide since its recent discovery. While related to tobacco mosaic virus, its properties and infection mechanisms are poorly understood. To uncover their structure and nanomechanics, we carried out atomic force microscopy (AFM) measurements on individual ToBRFV particles. The virions are rod-shaped with a height and width of 9 and 30 nm, respectively. Length is widely distributed (5–1000 nm), with a mode at 30 nm. ToBRFV rods displayed a 22.4 nm axial periodicity related to structural units. Force spectroscopy revealed a Young’s modulus of 8.7 MPa, a spring constant of 0.25 N/m, and a rupture force of 1.7 nN. In the force curves a step was seen at a height of 3.3 nm, which is related to virion wall thickness. Wall thickness was also estimated by predicting coat protein structure with AlphaFold, yielding a protein with a length of 7.3 nm. Accordingly, the structural element of ToBRFv is a right circular cylinder with an equal height and diameter of ~22 nm and a wall thickness between 3.3 and 7.3 nm. Thus, at least four to nine serially linked units are required to encapsidate a single, helically organized RNA genome. Fragmentation of ToBRFV into these cylindrical structural units may result in a facilitated release of the genome and thus efficient infection. Full article

Using established results, we examine how a turbulent magnetic field in an outer core emerges and manifests itself as the geomagnetic field. Two basic results are demonstrated: First, how the stationary interior magnetic dipole components gain fluctuating parts, leading to polar wander of the geomagnetic dipole. Second, how the relation between the interior dipole energy ${\mathcal{E}}_D$ and magnetic helicity ${\mathcal{H}}_M$, i.e., ${\mathcal{E}}_D=k_{min}{\mathcal{H}}_M$, permits us to estimate the value of ${\mathcal{H}}_M$ in the outer core from the strength of the geomagnetic dipole field. We also discuss how MHD turbulence with magnetic helicity may be seen as the essential engine of the geodynamo. Full article

In gas drilling operations, the blooey line is highly susceptible to erosion-induced leakage. This study focuses on the use of field-welded V-shaped elbows in blooey lines, establishing a numerical method for erosion prediction and validating its accuracy through experimental data. The numerical results reveal that, due to the inclined configuration of the V-shaped elbow, particles from the central inlet flow directly impact the outer wall of the outlet pipe opposite the inlet, and then rebound and strike the inner wall. Meanwhile, solid particles near the pipeline wall on both sides of the inclined plane collide with the outer wall and exit in a helical flow pattern along the outlet pipe. The maximum erosion rate (3.6 × 10⁻⁴ kg/(m²·s)) occurs at the intersection of these spiral particle flows. Based on erosion predictions under various operating conditions, an empirical formula was established to correlate the erosion rate with the gas injection rate at a rate of penetration (ROP) of 1 m/h, along with corresponding conversion relationships for different ROPs. The predicted residual thickness of the V-shaped elbow showed a 6.8% relative error compared to field measurements. The proposed method can be programmed to enable real-time monitoring of the residual wall thickness and the remaining service life of the blooey line before leakage occurs, assisting field operators in determining optimal pipeline replacement schedules to ensure operational safety. Full article

Cancer cells can adapt to their surrounding microenvironment by upregulating glucose-regulated protein 78 kDa (GRP78) and vacuolar-type ATPase (V-ATPase) proteins to increase their proliferation and resilience to anticancer therapy. Therefore, targeting these proteins can obstruct cancer progression. A comprehensive computational study was conducted to investigate the inhibitory potential of four proton pump inhibitors (PPIs), dexlasnoprazole (DEX), esomeprazole (ESO), pantoprazole (PAN), and rabeprazole (RAB), against GRP78 and V-ATPase. Molecular docking revealed high-affinity scores for PPIs against both proteins. Moreover, molecular dynamics showed favorable root mean square deviation values for GRP78 and V-ATPase complexes, whereas root mean square fluctuations were high at the substrate-binding subdomains of GRP78 complexes and the α-helices of V-ATPase. Meanwhile, the radius of gyration and the surface-accessible surface area of the complexes were not significantly affected by ligand binding. Trajectory projections of the first two principal components showed similar motions of GRP78 structures and the fluctuating nature of V-ATPase structures, while the free-energy landscape revealed the thermodynamically favored GRP78-RAB and V-ATPase-DEX conformations. Furthermore, the binding free energy was −16.59 and −18.97 kcal/mol for GRP78-RAB and V-ATPase-DEX, respectively, indicating their stability. According to our findings, RAB and DEX are promising candidates for GRP78 and V-ATPase inhibition experiments, respectively. Full article

Background and Objectives: Total body irradiation (TBI) remains a cornerstone of conditioning for allogeneic haematopoietic stem-cell transplantation (HSCT). Whereas early research debated the need for irradiation, contemporary investigations focus on optimising dose, fractionation and delivery techniques. Material and Methods: We synthesised six decades of evidence, spanning from single-fraction cobalt treatments to modern helical tomotherapy and intensity-modulated total-marrow/lymphoid irradiation (TMI/TMLI). To complement the literature, we reported our institutional experience on 77 paediatric and adult recipients treated with conventional extended-source-to-skin-distance TBI at the University Hospital Policlinico “G. Rodolico–San Marco” between 2015 and 2025. Results: According to literature data, fractionated myeloablative schedules, typically 12 Gy in 6 fractions, provide superior overall survival and lower rates of severe graft-versus-host disease (GVHD) compared with historical single-dose regimens. Conversely, reduced-intensity protocols of 2–4 Gy broaden HSCT eligibility for older or comorbid patients with acceptable toxicity. Conformal planning reliably decreases mean lung dose without compromising engraftment, and early-phase trials are testing selective escalation to 16–20 Gy or omission of TBI in molecularly favourable cases. With regard to our institutional retrospective series, 92% of patients completed a 12-Gy regimen with only transient grade 1–2 nausea, fatigue or hypotension; all transplanted patients engrafted, and no grade ≥ 3 radiation pneumonitis occurred. Conclusions: Collectively, the published evidence and our experience support TBI as an irreplaceable component of HSCT conditioning and suggest that coupling it with advanced imaging, organ-sparing dosimetry and molecular response monitoring can deliver safer, more personalised therapy in the coming decade. Full article

At present, high-resolution and reliable inductive sensors have increasingly emerged as a pivotal component in the advancement of flexible electronic devices. The integration of liquid metal with flexible substrates presents a promising approach for the fabrication of inductive sensors. This paper introduces a novel paperclip-type helical coil inductive sensor, characterized by advancements in both structural design and a simplified manufacturing process. The sensor comprises a fine silicone tube filled with liquid metal, encapsulated within polydimethylsiloxane (PDMS) glue. A significant innovation of this design is its complete elimination of the need for high-precision sacrificial metal molds. This approach bypasses complex processes such as precision mold machining, demolding, and post-mold residue cleaning, thereby significantly streamlining the production work-flow. We optimized the parameters of the paperclip-type helical coil, the aspect ratio, and the number of turns, achieving the maximum sensitivity under limited conditions. Experimental results demonstrate that this sensor is capable of tensile, pressure, and non-contact distance sensing. The linearity of the tensile sensing is exceptional ($R^2=0.999$), with consistent performance observed after 800 tensile cycles. The pressure sensing range extends from 0 to 230 kPa, and the non-contact distance sensing is effective within a range of 10 mm. Furthermore, the sensor exhibits strong performance in monitoring human physiological activities and metal distance detection, demonstrating significant application potential in flexible electronics and wearable devices. Full article

This study investigates the effectiveness of combining helical piles (HPs) with geogrid reinforcement compared to conventional piles in improving pullout performance in dense sand, addressing a key challenge in reinforced foundation design. A comprehensive experimental program was conducted to evaluate the pullout behavior of HPs embedded in Shahriyar sand reinforced with geogrid layers. The research focused on quantifying the effects of critical parameters—pile configuration, helix pitch, and geogrid placement depth—on ultimate pullout capacity and displacement response to better understand hybrid reinforcement mechanisms. Pullout tests were performed using a Zwick/Roell Z150 universal testing machine with automated data acquisition via TestXpert11 V3.2 software. The experimental program assessed the following influences: (1) pile configurations—plain, single-helix, and double-helix; (2) helix pitch ratios of 1.00, 1.54, and 1.92 (pitch-to-shaft diameter); and (3) geogrid placement depths of 7.69, 11.54, and 15.38 (depth-to-shaft diameter) on pullout behavior. Results demonstrate that geogrid reinforcement substantially enhances pullout resistance, with single-helix HPs achieving up to a 518% increase over plain piles. Pullout resistance is highly sensitive to geogrid spacing, with optimal performance at a non-dimensional distance of 0.47 from the pile–soil interface. Additionally, double-blade HPs with geogrid placed at 0.35 exhibit a 62% reduction in displacement ratio, underscoring the role of geogrid in improving pile stiffness and load-bearing capacity. These findings provide new insights into the synergistic effects of helical pile geometry and geogrid placement for designing efficient reinforced granular foundations. Full article

Anthrax remains a serious bioterrorism threat for which new and thermostable vaccines are needed. We previously demonstrated that immunization of rabbits with multiple-antigenic-peptide (MAP) vaccines elicit antibody (Ab) against the loop-neutralizing-determinant (LND), a cryptic linear neutralizing epitope in the 2β2-2β3 loop of protective antigen (PA) from Bacillus anthracis (B. anthracis), which mediates the complete protection of rabbits from inhalation spore challenge with B. anthracis Ames strain. Importantly, LND-specific Ab is not significantly elicited with PA-based vaccines. In the current study, we sought to identify a second unique neutralizing epitope which would also not overlap with the neutralizing specificities elicited by PA-based vaccines, and which could be combined with an LND vaccine as a prototype bivalent vaccine for anthrax. We evaluated linear peptide sequences in the α2-α3 helices of domain 3 of lethal factor (LF) in the form of virus-like particle (VLP) vaccines. Immunogenicity studies confirmed the presence of a 20-mer peptide sequence that is capable of eliciting protective levels of neutralizing Ab following two immunizations of rabbits using human-use adjuvants, and lyophilization of the VLPs did not diminish their immunogenicity. To our knowledge, this is the first demonstration that immunization with linear peptide sequences from LF can elicit protective levels of neutralizing Ab in vivo. Full article

Antimicrobial peptides (AMPs) are the promising candidates for the development of next-generation antimicrobials for agriculture and medicine; however, their large-scale production is costly. The γ-core motif peptides, functionally significant fragments of AMPs responsible for the antimicrobial activity, provide a more economical and feasible approach for the commercial development of novel antimicrobials. In the present work, we undertook a comprehensive study of antimicrobial properties of several γ-core peptides derived from defensins and snakins of Filipendula ulmaria, a medicinal plant known for its valuable pharmacological properties. The γ-core peptides were produced by solid-phase synthesis and purified by RP-HPLC. Their physicochemical properties underlying biological activity were predicted. All the peptides ranging in size from 14 to 18 amino acid residues were positively charged. All peptides except one were predicted to be α-helical and antimicrobial. The synthetic peptides were in vitro tested against a wide panel of plant and human fungal and bacterial pathogens. A short overview of the pathogens used in antimicrobial assays with a special emphasis on their economic, social, and medicinal impacts is provided. As a result of our work, we identified the peptides with pronounced activity in low-micromolar range against particular pathogens that can serve as prototypes for the development of novel biopesticides and antimicrobials for medicine. We also revealed synergism of action between particular γ-core peptide pairs and demonstrated that interference with membrane permeabilization contributes to the peptides’ mode of action. The results obtained broaden our understanding of plant AMPs, the key players in plant immunity, and provide novel highly efficient peptides with high potential in practical applications. Full article

Formed milling is one of the most commonly used methods for machining the helical surfaces of various screw rotors. The profile of a formed cutter is designed according to the profile of the helical surface, which is usually represented by discrete points. The most widely used analytical method is rather complex, and it is easy to obtain singular points. To obtain a reliable cutter profile and simplify the solution procedure, a general numerical method suited for rotors with an arbitrary tooth profile is proposed. The proposed method does not need to establish and solve the complex nonlinear contact equation and can determine the contact point accurately. Firstly, a series of intersection planes that are perpendicular to the revolving axis of the cutter is constructed. The searching of the contact points of the selected tooth curves with each intersection plane is achieved using the subdivision method. By this means, the plane–curve intersection is simplified to a straight line–curve intersection that can easily be solved via Newton iteration. Meanwhile, the machinability related to the profile of the formed cutter can also be analyzed. Two cutter profiles are used to validate the proposed method. The cutter profiles generated by the proposed method are compared with the profiles generated by the analytical method. The results indicate that the accuracy and computational efficiency increase significantly. Furthermore, the proposed method can also be applied to the design of formed grinding wheels. Full article

To address the critical challenges of severe fragmentation in cuttings, persistent cuttings bed accumulation, and abrupt friction torque increases during horizontal well drilling of Jurassic continental shale oil formations in J Block, Sichuan Basin—rooted in the unique high clay content that induces colloidal stability of fine cuttings and resistance to conventional cleaning—this study innovatively proposes a coupled prevention–removal hole-cleaning technology. The core methodology integrates three synergistic components: (1) orthogonal numerical simulations to optimize drilling parameters, reducing the cuttings input rate by 43.48% through “hydraulic carrying + mechanical agitation” synergy; (2) a modified Moore model with horizontal section correction factors to quantify slip velocity of cuttings, lowering the prediction error from ±20% to ±5%; and (3) a helical groove cutting removal sub with 60 m optimal spacing, enhancing local turbulence intensity by 42% to disrupt residual cuttings bed. Field validation in Well J110-8-1H demonstrated remarkable improvements: a 50% reduction in sliding friction, a 25% decrease in rotational torque, and 40% shortening of the drilling cycle. This integrated technology fills the gap in addressing the “fragmentation–colloidal stability” dilemma in shale with high clay contents, providing a quantifiable solution for safe and efficient drilling in similar continental formations. Full article

Background: The amount of data produced from biological experiments has increased geometrically, posing a challenge for the development of new methodologies that could enable their interpretation. We propose a novel approach for the analysis of transcriptomic data derived from acute lymphoblastic leukemia (ALL) and rhabdomyosarcoma (RMS) cell lines, using bioinformatics, systems biology and geometrical approaches. Methods: The expression profile of each cell line was investigated using microarrays, and identified genes were used to create a systems pathway model, which was then simulated using differential equations. The transcriptomic profile used involved genes with similar expression levels. The simulated results were further analyzed using geometrical approaches to identify common expressional dynamics. Results: We simulated and analyzed the system network using time series, regression analysis and helical functions, detecting predictable structures after iterating the modelled biological network, focusing on TIE1, STAT1, MAPK14 and ADAM17. Our results show that such common attributes in gene expression patterns can lead to more effective treatment options and help in the discovery of universal tumor biomarkers. Discussion: Our approach was able to identify complex structures in gene expression patterns, indicating that such approaches could prove useful towards the understanding of the complex tumor dynamics. Full article

The paper presents aspects of the elastic behavior of a springboard in school gyms after contact with a basketball (0.500 kg) falling from a height of 1 m or a volunteer student jumping from 30 or 60 cm in three different areas at the end of the springboard. The results recorded obtained from three accelerometers mounted under the main plate of the springboard are presented, primarily focusing on the accelerations and vertical displacements after contact. The springboard has a special construction, the upper plate and the curved support plates being provided with two pairs of conical and cylindrical truncated helical springs, respectively. The accelerometers were placed at different points, centrally on the upper plate and on the support plates. It was found that in the dynamic process of a body falling on the springboard, the coefficient of elasticity/rigidity of the elastic system changes, presenting values of 22.14–71.12 kN/m. Normally, both accelerations and displacements are greater on the upper plate, but its vibratory motion also induces additional movements and vibrations on the two lower plates. The results may be useful both for manufacturers of such equipment and for coaches to give appropriate instructions to athletes. Full article

Background/Objectives: Cancer is one of the leading causes of death worldwide, and skin cancer is especially prevalent and lethal in Brazil. Despite advancements in treatment, there is still a need for new anticancer agents that are effective, selective, and less toxic. This study aimed to evaluate the cytotoxic and therapeutic potential of the peptide PEPAD. Methods: The cytotoxicity of PEPAD was assessed by MTT assay in murine melanoma (B16F10-Nex2), human melanoma (SK-MEL-28), breast (MCF-7), and cervical (HeLa) cancer cell lines. Selectivity was evaluated in healthy cells (RAW 264.7 and FN1). Morphological changes were analyzed by microscopy. Cell migration was assessed using scratch assays. Apoptotic features were evaluated using MitoTracker Deep Red, NucBlue, CaspACETM labeling, and flow cytometry. Immunogenic cell death was investigated by calreticulin and HMGB1 release. Molecular dynamics simulations explored peptide structure and interaction with lipid membranes. Results: PEPAD showed IC₅₀ values of 7.4 µM and 18 µM in B16F10-Nex2 and SK-MEL-28 cells, respectively, and >60 µM in MCF-7 and HeLa cells. Low toxicity was observed in healthy cells (IC₅₀ > 56 µM), indicating high selectivity. Apoptotic morphology and reduced cell migration were observed. Flow cytometry and fluorescence probes confirmed apoptosis and mitochondrial swelling. Calreticulin and HMGB1 release indicated immunogenic cell death. Simulations showed that PEPAD maintains a stable α-helical conformation and interacts with membranes. Conclusions: These findings highlight PEPAD’s selective cytotoxicity and its potential as an anticancer agent with apoptotic and immunogenic properties, making it a promising candidate for therapeutic development. Full article

This study aims to develop a new model for windage losses, building upon existing formulation, complemented by dedicated experimental campaigns and a specific methodology designed to isolate and quantify windage losses. The model relies on an analytical approach to flow characterization, incorporating a correction factor accounting for air density reduction. The experimental investigation was carried out on a dedicated test bench and includes both spur and helical gears. The results demonstrate good agreement between the proposed model and the experimental data, with and without the presence of nearby obstacles, such as side flanges, highlighting the model’s robustness across different configurations. The proposed windage loss model reproduces the experimental results with significantly greater accuracy than the original one, yielding relative deviations below 5% compared to almost 20% for spur gears, and below 9% compared to over 21%, and in some cases up to 50%, for helical gears. Full article