Search Results (961)

The atmospheric reentry of hypersonic vehicles generates a plasma sheath enveloping the vehicle surface. This fluid medium moves at velocities distinct from the vehicle body, significantly altering its electromagnetic scattering properties. This paper introduces a Multi-Frame Lorentz Transformation Finite-Difference Time-Domain (FDTD) method, which incorporates a spatially varying velocity field into the computational scheme. The proposed algorithm maintains velocity synchronization in electromagnetic field updates and employs a near-to-far-field transformation for far-zone analysis. We systematically investigate the scattering characteristics of a plasma-sheath-covered hypersonic vehicle across a range of velocities and analyze the effect of velocity on the Radar Cross-Section (RCS) under different polarization conditions. Full article

The HIV-1 envelope glycoprotein gp120 is prominently exposed on the surface of both HIV-1 virions and infected host cells, serving as a key marker of infection. gp120 plays a pivotal role in viral entry by interacting with the primary receptor, CD4, on host cells. Therapeutic strategies targeting the HIV-1 reservoir, such as anti-gp120 antibodies that trigger antibody-dependent cellular cytotoxicity (ADCC) and chimeric antigen receptor T (CAR-T) cells, rely on the presence of gp120 on the surface of infected cells to exert their effects. Consequently, accurate monitoring of gp120 expression on infected cells is essential for evaluating the pharmacological efficacy of these interventions. In this study, a sensitive, specific, and inexpensive enzyme-linked immunosorbent assay (ELISA) for quantifying HIV-1 gp120 glycoprotein was developed using a selected pair of anti-gp120 antibodies. The assay achieved a lower limit of quantitation (LLOQ) of 0.16 pM, demonstrating sensitivity comparable to that of the digital single molecule array (Simoa) platform, which exhibited a LLOQ of 0.23 pM and requires specialized instrumentation. The binding specificity of the antibodies used in the novel assay was confirmed using liquid chromatography–mass spectrometry (LC-MS), and the assay was pharmacologically validated with lysates obtained from 2D10 and MOLT IIIB cell lines. Furthermore, treatment of HIV-infected human primary CD4⁺ T cells with a targeted activator of cell kill (TACK) compound significantly reduced gp120 concentration in CD4⁺ T cell lysate compared to controls. The gp120 marker from infected cell lysates correlated with the number of gp120-positive cells detected by immunocytochemistry, as well as with HIV-1 p24 levels and cell-associated viral RNA measurements. In summary, a novel, simple, and sensitive HIV-1 gp120 ELISA has been developed and validated. This assay holds potential for investigating HIV-1 persistence and evaluating the efficacy of therapeutic agents targeting infected cells. Full article

The article presents the results of a comprehensive full-scale investigation of the influence of solar radiation on the thermal behavior of the exterior envelope systems of two residential buildings of different heights—a 9-storey building in Turkestan and a 25-storey building in Shymkent. The façade systems of both buildings consist of a multilayer enclosure with a ventilated air cavity, 100 mm wide in the 9-storey building and 50 mm wide in the 25-storey building. The objective of the study was to determine the diurnal and vertical dynamics of temperature fields, analyze the thermal inertia of the materials, and assess the effect of façade geometry on heat-transfer performance. Thermographic measurements were carried out during key periods of the day (7:00, 10:00, 13:00, and 17:00), which enabled coverage of the full solar-insolation cycle. The results showed that the maximum temperatures of the external cladding reached 48–52 °C for the 9-storey building and 53–58 °C for the 25-storey building, with a vertical temperature gradient of 3–7 °C. The temperature of the interior surface varied within 28–32 °C and 29–34 °C, respectively, reflecting the influence of both solar heating and the width of the ventilation cavity on heat transfer. It was found that reducing the air-gap width intensifies natural convection and decreases the thermal inertia of the system, resulting in sharper temperature fluctuations. The study demonstrates that current design standards insufficiently account for the vertical non-uniformity of solar exposure and the aerodynamic processes within the ventilation channel. The findings can be used in the design of energy-efficient façade systems, in the refinement of regulatory methodologies, and in the development of heat-transfer models for high-rise buildings under conditions of increased solar radiation. Full article

Embankments are extensively applied in civil engineering and exist naturally, characterized by a constant slope ensuring stable material stacking. Despite their ubiquity, research on embankment surface geometric modeling remains limited. Three novel construction methods for embankment surfaces are proposed: the envelope of a one-parameter family of cones, the envelope of constant-slope tangent planes, and the geometric limit. Subsequently, the properties of embankment surfaces and their geometric interpretation are elaborated. Specific examples are provided to illustrate that these methods offer convenient and feasible alternatives for engineering geometric design related to these surfaces. Full article

Viral fusion proteins are indispensable mediators of viral entry that orchestrate the fusion of viral and host membranes, making them primary targets for antiviral interventions. Class I fusion proteins, displayed on the surface of enveloped viruses (such as HIV-1, RSV, SARS-CoV-2, Nipah, influenza, and Ebola viruses), share conserved structural features, including the fusion peptide or loop and heptad repeat regions. These elements are essential for the formation of the post-fusion six-helix bundle during membrane fusion. Peptide inhibitors that mimic heptad repeat motifs have consequently emerged as an effective strategy for blocking the fusion process. This review summarizes design strategies for such inhibitors and highlights how sequence and structural insights have enabled their optimization via α-helical stabilization, hydrocarbon stapling, lactam bridges, lipid conjugation, macrocyclization, and multivalency. Using representative examples across major viral systems, this review illustrates how these strategies have led to the development of potent, stable, and even broad-spectrum antiviral peptides. This review provides insights to guide the rational design of next-generation peptide-based fusion inhibitors targeting viral membrane fusion. Full article

Additive manufacturing (AM) enables the consolidation of components and the integration of new functionalities in metallic parts, but layered fabrication often results in poor surface quality and geometric deviations. Among various surface treatment techniques, machining is often favoured for its capability to enhance not only surface finish but also critical geometric tolerances such as flatness and circularity, in addition to dimensional accuracy. However, machining AM components, particularly thin-walled structures, poses challenges related to unconventional material properties, complex fixturing, and heightened susceptibility to chatter. This study investigates the vibrational behaviour of thin-walled Ti6Al4V components produced via laser powder bed fusion, using a jet-engine compressor blade demonstrator. Four stock envelope designs were evaluated: constant, tapered, and two topologically optimised variants. After fabrication by Laser Powder Bed Fusion, the blades underwent tap testing and subsequent machining to assess changes in modal characteristics. The results show that optimised geometries can enhance modal performance without increasing the volume of the stock material. However, these designs exhibit more pronounced in situ modal changes during machining, due to greater variability in material removal and chip load, which amplifies vibration sensitivity compared to constant or tapered stock designs. Full article

Background: Skin barrier dysfunction leads to increased transepidermal water loss (TEWL), inflammation, and compromised skin protection. While Paeonia ostii (peony) flowers are recognized in traditional Chinese medicine for their reducing melanin synthesis, anti-inflammatory, and anti-aging effects, their role in repairing skin barrier damage has not been fully explored. Methods: We investigated the therapeutic potential of peony flower extract (PFE) in the tape-stripping-induced mouse model with skin barrier damage. Skin surface imaging, hydration measurements, H&E, proteomics, qPCR, and immunofluorescence were applied to clarify the potential mechanism of PFE in attenuating skin barrier impairment. Results: PFE significantly reduced erythema, TEWL, and edema while restoring epidermal architecture. Proteomics analysis identified cornified envelope formation and tight junction assembly as essential mechanisms in skin barrier repair. It increased the expression of key skin barrier proteins, including filaggrin (Flg), involucrin (Ivl), loricrin (Lor), claudin-1 (Cldn1), tight junction protein 1 (Tjp1), and occludin (Ocln). Conclusions: This study demonstrates that PFE restores skin barrier integrity by upregulating key structural proteins within the cornified envelope and tight junction. These findings suggest that PFE is a promising therapeutic candidate for skin barrier repair, with high potential in translational medicine applications. Full article

The construction sector accounts for 39% of GHG emissions, being the main contributor to embodied carbon emissions of building materials, and operational energy consumption for indoor thermal comfort. Cereal straw, an agricultural by-product, is emerging as a low-carbon alternative due to its thermal performance and negative embodied carbon. This paper aims to review recent advances of cereal straw as a building material for decarbonization of construction, analyzing its thermal properties, embodied carbon, and large-scale applications. A literature review focused on European-certified straw-based materials, grouped into four categories: straw bales, blown-in insulation, modular systems, and bio-composites. Twelve Product Environmental Declarations (EPDs) and technical specifications were examined to evaluate manufacturing processes, material properties, and Global Warming Potential (GWP) for cradle-to-gate stages (A1–A3), as well as their use in large-scale projects over the past five years. Thermal conductivity ranged from 0.043 to 0.068 W/m·K, while embodied carbon varied between –101.2 and –146.5 kg CO₂ eq/m³. Straw bales remain prevalent in small-scale housing, blown-in insulation supports retrofitting, and modular systems offer the most balanced performance, enabling high-rise or extensive built surfaces. The study concludes that straw products have the potential to decarbonize opaque elements of the envelope, reducing operational and embodied energy of buildings. Full article

Human transmembrane proteins Serinc3 and Serinc5 are antiviral restriction factors that inhibit HIV-1 infectivity. In the absence of viral antagonism, Serinc3 and Serinc5 incorporate into the envelopes of nascent virions and inhibit the fusion of virions to the target cells. The HIV-1 virus counteracts the restriction of Serinc3 by downregulating it from the cell surface and thus excluding it from budding virions. This is orchestrated by the viral accessory protein Nef and involves hijacking of the clathrin adaptor protein complex 2 (AP2)-dependent endocytosis. The mechanistic details of Nef-mediated Serinc3 downregulation, however, have been enigmatic. In this work, we investigated and revealed the molecular determinants of Serinc3 modulation by Nef. Our results show that Nef recruits Serinc3 by binding to its N-terminal cytosolic tail. Furthermore, Nef residues important for Serinc3-binding in vitro, and for the exclusion of Serinc3 from virions, overlap with those required for Nef-mediated CD4 downregulation, suggesting great mechanistic similarities between the two functions of Nef. In addition to shedding light on the mechanism of Serinc3 antagonism, our work also highlights the conserved substrate-binding pocket of Nef as a molecular hotspot for inhibitor development and antiretroviral drug discovery. Full article

To address the poor thermal insulation and freeze resistance of rural outdoor toilets in cold regions—key obstacles to achieving the UN Sustainable Development Goal (SDG) 6.2 and popularizing rural sanitary toilets—this study fills the literature gap of insufficient research on passive solar heating systems tailored for rural toilets in cold climates. Using TRNSYS simulation, Plackett–Burman key factor screening, single-factor experiments, and Box–Behnken response surface methodology, we optimized the system with building envelope thermal parameters and Beijing’s typical meteorological year data as inputs, taking January’s average indoor temperature as the core evaluation index. Results indicated six parameters (solar wall area, air cavity thickness, vent area ratio, vent spacing, exterior wall insulation thickness, and heat-gain window-to-wall ratio) significantly influence indoor temperature (p < 0.05). The optimal configuration was as follows: solar wall area 3.45 m², window-to-wall ratio 30%, exterior wall insulation thickness 200 mm, vent spacing 1800 mm, air cavity thickness 43 mm, and vent area ratio 5.7%. Post-optimization, the average temperature during the heating season reached 10.81 °C (79.5% higher than baseline), with January’s average, maximum, and minimum temperatures at 7.95 °C, 20.47 °C, and −1.42 °C, respectively. This solution effectively prevents freezing of flushing fixtures due to prolonged low temperatures, providing scientific support for the application of passive rural toilets in China’s cold regions. Full article

Fomites are common vehicles for viral transmission. Most studies on virus disinfection have focused on non-porous, hard surfaces, with few investigating porous materials. This review addresses two research questions: (1) What affects viral viability on reusable porous materials? (2) Which antimicrobials effectively target viruses on these materials? Among existing studies, viral persistence on reusable porous surfaces was influenced by several factors, including viral envelope status, virus subtype, material type and structure, temperature, relative humidity, deposition method, and transmission medium. Disinfectants evaluated included ultraviolet irradiation, steam, chlorine, quaternary ammonium compounds, alcohols, glutaraldehyde, silver, and peroxide-based agents. Chlorine and steam were most effective; glutaraldehyde and peroxides showed limited action against non-enveloped viruses. Viral persistence and disinfection efficacy on reusable porous materials are influenced by multiple factors, highlighting the need for robust environmental management and infection control practices. Lack of standard tests and long-term disinfection effects on material integrity remain key challenges needing further study. Full article

The rise in thermal runaway events within electric vehicle (EV) battery systems requires anticipatory models to predict critical safety failures during operation. This investigation develops a multi-physics digital twin framework that links electrochemical, thermal, and structural domains to replicate the internal dynamics of lithium-ion packs in both normal and faulted modes. Coupled simulations distributed among MATLAB 2024a, Python 3.12-powered three-dimensional visualizers, and COMSOL 6.3-style multi-domain solvers supply refined spatial resolution of temperature, stress, and ion concentration profiles. While the digital twin architecture is designed to accommodate different battery chemistries and pack configurations, the numerical results reported in this study correspond specifically to a lithium NMC-based 4S3P cylindrical cell module. Quantitative benchmarks show that the digital twin identifies incipient thermal deviation with 97.4% classification accuracy (area under the curve, AUC = 0.98), anticipates failure onset within a temporal margin of ±6 s, and depicts spatial heat propagation through three-dimensional isothermal surface sweeps surpassing 120 °C. Mechanical models predict casing strain concentrations of 142 MPa, approaching polymer yield strength under stress load perturbations. A unified operator dashboard delivers diagnostic and prognostic feedback with feedback intervals under 1 s, state-of-health (SoH) variance quantified by a root-mean-square error of 0.027, and mission-critical alerts transmitting with a mean latency of 276.4 ms. Together, these results position digital twins as both diagnostic archives and predictive safety envelopes in the evolution of next-generation EV architectures. Full article

Windows represent a critical component of a building’s envelope, influencing not only thermal performance and natural interior lighting but also the overall environmental impact of the structure. This study applies life cycle assessment to evaluate the impacts of operable and fixed wood-based windows covering the system boundaries of the product stage and maintenance. Scenarios are modelled for different frame surface treatments, regarding varnish layers, paint presence, and aluminium cladding. The impact categories assessed include elements, fossils, and ozone layer depletion; potentials of global warming, acidification, eutrophication; photochemical ozone creation; and toxicity to humans, freshwater and marine water, as well as terrestrial ecotoxicity. The results indicate that the embodied environmental impact of the wood material alone remains relatively small while glazing and aluminium cladding dominate. Regarding the surface treatment, the varnish quantity as well as the presence of paint do not significantly influence the environmental impact. Differences between operable and fixed windows also reflect additional materials and hardware requirements, resulting in operable windows exhibiting higher environmental impacts across all assessed categories. The findings of this study highlight the important role of structural elements and additional components on the overall environmental impact regarding the complexity of a window. Full article

Cavitation erosion is a major concern in hydraulic systems exposed to strong pressure fluctuations. Well-developed experimental techniques exist for detecting cavitation based on measuring induced noise or vibrations, but additional tools are needed to assess its aggressiveness under operating conditions. This study investigates the capability of acoustic emission (AE) to characterise cavitation aggressiveness during long-duration cloud cavitation. A 50 h erosion test was performed in a closed-loop cavitation tunnel using a Venturi equipped with an aluminium 7075-T6 specimen. Hydraulic conditions were controlled to maintain a constant cavity length, and AE signals were recorded every 10 min during two representative 4 h intervals at 34–38 h and 46–50 h. A new AE-derived power parameter was defined using the amplitude distribution of AE envelope peaks. Both the number of impacts and the power parameter increased markedly from the intermediate to the final interval, consistent with the growth of erosion and increasing surface roughness. Conversely, both quantities decreased systematically within each 2 h test as water temperature increased. Image analysis of selected areas confirmed the progression of pitting between 34 and 50 h. Overall, the findings demonstrate that AE can capture the combined influence of temperature and surface degradation on cavitation aggressiveness, highlighting its potential as a monitoring technique for hydraulic components. Full article

This study presents a modular diagnostic framework for evaluating thermal degradation in aging building envelopes by integrating infrared thermography, panoramic reconstruction, and deep learning-based semantic segmentation into a unified workflow. The methodology combines image registration, panoramic synthesis, façade component segmentation, and quantitative surface temperature analysis to provide scalable and reproducible diagnostics. By excluding fenestration zones—where infrared measurements are physically unreliable—the framework focuses on opaque wall regions and window surroundings to ensure physically meaningful evaluation. Field validation was conducted on a multi-story office building constructed in 1996. The diagnostic indicators revealed a mean wall surface temperature of 14.3 °C with a standard deviation of 5.6 °C, and a temperature factor ranging from 0.67 to 0.78 under measured conditions. The vulnerable area ratio reached 9.1% for walls, while window areas showed greater vulnerability at 12.74%, with anomalies concentrated at frame–glass interfaces and perimeter seals. These quantitative results confirmed the framework’s ability to detect thermal irregularities and visualize localized anomalies. More importantly, the contribution of this study lies in establishing a systematic and extensible diagnostic pipeline that advances building envelope analysis, supporting large-scale energy audits, retrofit prioritization, and sustainable building management. Full article