Microfluidic particle counter visualizing mucosal antibodies against SARS-CoV-2 in the upper respiratory tract for rapid evaluation of immune protection.

Mucosal antibodies in the upper respiratory tract are the earliest and most critical responders to prevent respiratory infections, providing an indication for the rapid evaluation of immune protection. Here, we report a microfluidic particle counter that directly visualizes mucosal antibody levels in nasal mucus. The mucosal anti-SARS-CoV-2 spike receptor binding domain (RBD) antibodies in nasal secretions first react with magnetic microparticles (MMPs) and polystyrene microparticles (PMPs) that are surface-modified to form a "MMPs-anti-spike RBD IgG-PMPs" complex when RBD is present. After magnetic separation and loading into the microfluidic particle counter, the free PMPs, which are reduced with increasing anti-spike RBD IgG antibody levels, are trapped by a microfluidic particle dam and accumulate in the trapping channel. A sensitive mode [limit of detection (LOD): 14.0 ng mL-1; sample-to-answer time: 70 min] and an equipment-free rapid mode (LOD: 37.4 ng mL-1; sample-to-answer time: 20 min) were achieved. Eighty-seven nasal secretion (NS) samples from vaccinees were analyzed using our microfluidic particle counter, and the results closely resemble those of the gold-standard enzyme-linked immunosorbent assay (ELISA). The analysis shows that higher antibody levels were found in convalescent volunteers compared to noninfected volunteers. Together, we demonstrate a rapid kit that directly indicates immune status, which can guide vaccine strategy for individuals and the government.

On-Site Melanoma Diagnosis Utilizing a Swellable Microneedle-Assisted Skin Interstitial Fluid Sampling and a Microfluidic Particle Dam for Visual Quantification of S100A1.

Malignant melanoma (MM) is the most aggressive form of skin cancer. The delay in treatment will induce metastasis, resulting in a poor prognosis and even death. Here, a two-step strategy for on-site diagnosis of MM is developed based on the extraction and direct visual quantification of S100A1, a biomarker for melanoma. First, a swellable microneedle is utilized to extract S100A1 in skin interstitial fluid (ISF) with minimal invasion. After elution, antibody-conjugated magnetic microparticles (MMPs) and polystyrene microparticles (PMPs) are introduced. A high expression level of S100A1 gives rise to a robust binding between MMPs and PMPs and reduces the number of free PMPs. By loading the reacted solution into the device with a microfluidic particle dam, the quantity of free PMPs after magnetic separation is displayed with their accumulation length inversely proportional to S100A1 levels. A limit of detection of 18.7 ng mL-1 for S100A1 is achieved. The animal experiment indicates that ISF-based S100A1 quantification using the proposed strategy exhibits a significantly higher sensitivity compared with conventional serum-based detection. In addition, the result is highly comparable with the gold standard enzyme-linked immunosorbent assay based on Lin's concordance correlation coefficient, suggesting the high practicality for routine monitoring of melanoma.

Triple-Responsive Soft Actuator with Plastically Retentive Deformation and Magnetically Programmable Recovery.

Multistimuli responsiveness and programmable shape recovery are crucial for soft actuators in soft robotics, electronics, and wearables. However, existing strategies for actuation cannot attain power-free shape retention after removing the external energy supply. Here, a self-assembled density deposition method was developed to fabricate an electrothermal-NIR-magnetic triple-response actuator which was composed of cellulose nanofiber/poly(vinyl alcohol)/liquid metal (CNF/PVA/LM) and magnetic polydimethylsiloxane (MPDMS) layer. Interestingly, the large deformation can be controllably fixed and the temporary configuration will be programmable recovered under a magnetic field due to the thermal-plastic transferring behavior of the CNF/PVA/LM. Rolling robot prepared based on soft actuators exhibits good ability to avoid obstacles. In addition, the object handling and programmable release capabilities of the carrier robots demonstrate that this actuation approach will contribute to a better understanding of how to more rationally utilize various stimuli for application purposes.

Examining the trade-offs in clean energy provision: Focusing on the relationship between technology transfer, renewable energy, industrial growth, and carbon footprint reduction.

Sustainable energy mitigates climate change by reducing reliance on coal and oil for power generation, curbing global warming. It addresses environmental concerns and yields economic benefits-reduced fossil fuel dependence, financial inclusion, productive employment, and economic development. This research examines the impact of regional economic integration on environmental sustainability in 39 high-income European and Central Asian (ECA) nations from 2017 to 2021. Specifically, the study analyzes the influence of green energy demand, technological transfers, and trade openness on carbon emissions. The study employed various estimators, namely, a two-step Generalized Method of Moments (GMM) estimation, quantile regression, and the cointegration panel approach. These estimators were utilized to capture different aspects and dynamics of the research variables. The study finds that regional green programs and trade agreements effectively reduce carbon emissions, while technological advances and industrial output tend to raise them. Granger causality analyses reveal that emissions-led regional development, technical innovation, and trade openness are interconnected factors, and the deployment of renewable energy contributes to carbon emissions. The inter-temporal analysis suggests that regional economic integration factors will likely impact carbon emissions in the following decade. These findings support neoclassical growth theory, new institutional economics, and ecological modernization theory. Developing renewable energy sources in the region can minimize energy price fluctuations, strengthen energy security, and align with the carbon neutrality agenda. This research emphasizes the need for sustainable energy strategies and regional cooperation to foster a greener and more sustainable future.

Wearable Safeguarding Leather Composite with Excellent Sensing, Thermal Management, and Electromagnetic Interference Shielding.

This work illustrates a "soft-toughness" coupling design method to integrate the shear stiffening gel (SSG), natural leather, and nonwoven fabrics (NWF) for preparing leather/MXene/SSG/NWF (LMSN) composite with high anti-impact protecting, piezoresistive sensing, electromagnetic interference (EMI) shielding, and human thermal management performance. Owing to the porous fiber structure of the leather, the MXene nanosheets can penetrate leather to construct a stable 3D conductive network; thus both the LM and LMSN composites exhibit superior conductivity, high Joule heating temperature, and an efficient EMI shielding effectiveness. Due to the excellent energy absorption of the SSG, the LMSN composites possess a huge force-buffering (about 65.5%), superior energy dissipation (above 50%), and a high limit penetration velocity of 91 m s-1 , showing extraordinary anti-impact performance. Interestingly, LMSN composites possess an unconventional opposite sensing behavior to piezoresistive sensing (resistance reduction) and impact stimulation (resistance growing), thus they can distinguish the low and high energy stimulus. Ultimately, a soft protective vest with thermal management and impact monitoring performance is further fabricated, and it shows a typical wireless impact-sensing performance. This method is expected to have broad application potential in the next-generation wearable electronic devices for human safeguarding.

Ultra-Stretchable Spiral Hybrid Conductive Fiber with 500%-Strain Electric Stability and Deformation-Independent Linear Temperature Response.

Stretchable configuration occupies priority in devising flexible conductors used in intelligent electronics and implantable sensors. While most conductive configurations cannot suppress electrical variations against extreme deformation and ignore inherent material characteristics. Herein, a spiral hybrid conductive fiber (SHCF) composed of aramid polymeric matrix and silver nanowires (AgNWs) coating is fabricated through shaping and dipping processes. The homochiral coiled configuration mimicked by plant tendrils not only enables its high elongation (958%), but also generates a superior deformation-insensitive effect to existing stretchable conductors. The resistance of SHCF maintains remarkable stability against extreme strain (500%), impact damage, air exposure (90 days), and cyclic bending (150 000 times). Moreover, the thermal-induced densification of AgNWs on SHCF achieves precise and linear temperature response toward a broad range (-20 to 100 °C). Its sensitivity further manifests high independence to tensile strain (0%-500%), allowing for flexible temperature monitoring of curved objects. Such unique strain-tolerant electrical stability and thermosensation hold broad prospects for SHCF in lossless power transferring and expeditious thermal analysis.

Scalable pattern formation of skeletal myotubes by synergizing microtopographic cues and chiral nematics of cells.

Topographical cues have been widely used to facilitate cell fusion in skeletal muscle formation. However, an unexpected yet consistent chiral orientation of myotubes deviating from the groove boundaries is commonly observed but has long been unattended. In this study, we report a method to guide the formation of skeletal myotubes into scalable and controlled patterns. By inducing C2C12 myoblasts onto grooved patterns with different widths (from 0.4 to 200µm), we observed an enhanced chiral orientation of cells developing on wide grooves (50 and 100µm width) since the first day of induction. Active chiral nematics of cells involving cell migration and chiral rotation of the cell nucleus subsequently led to a unified chiral orientation of the myotubes. Importantly, these chiral myotubes were formed with enhanced length, diameter, and contractility on wide grooves. Treatment of latrunculin A (Lat A) suppressed the chiral rotation and migration of cells as well as the myotube formation, suggesting the essence of chiral nematics of cells for myogenesis. Finally, by arranging wide grooved/striped patterns with corresponding compensation angles to synergize microtopographic cues and chiral nematics of cells, intricate and scalable patterns of myotubes were formed, providing a strategy for engineering skeletal muscle tissue formation.

Flexible and Stretchable Elastomer Composites Based on Lightweight Liquid Metal Foam Spheres with Pod-like Contacts.

Liquid metal (LM) is increasingly employed as a conductive filler in soft and flexible elastomer composites owing to its favorable conductivity and liquid fluidity. However, the high density of LM inevitably increases the weight of composites, which brings limitations in large-area and weight-sensitive applications. This work reports a flexible and stretchable elastomer composite composed of pod-like contacting lightweight LM foam spheres and polydimethylsiloxane matrix (LMS/PDMS). The lightweight LMS reduces the amount of LM used in the preparation process while imparting good electrical conductivity and deformability to the composite. The different contact modes of LMS endow the final composites with diverse strain sensitivity. The mechanism of interfacial contact conduction between the LMS with different melting points has been systematically studied, and the result shows that the liquid-solid contact mode of LMS further improves the strain sensitivity of the composite. Moreover, the composite also has satisfactory electrothermal properties and the temperature can quickly reach 70 °C within 30 s, showing good applicability in electric heating. Finally, the composites containing LMS with different contact modes can be developed as multifunctional sensors to detect human activities, temperature variation, and even underwater vibration, demonstrating the great potential in next-generation sensors and electronics.

Enhancing Bioinspired Aramid Nanofiber Networks by Interfacial Hydrogen Bonds for Multiprotection under an Extreme Environment.

In nature, many insects have evolved sclerotic cuticles to shelter their soft bodies, which are considered as "body armor". For beetles, the epidermis is composed of cross-linked intertwined fiber structures; such a fiber network structure could provide an anti-impact function for composites. Aramid nanofibers (ANFs) are of great interest in various applications due to their 1D nanoscale, high aspect ratio, excellent strength and modulus, and impressive chemical and thermal stability. In this paper, a kind of ANF network is prepared by a layer-by-layer assembly method. The enhancing ANF networks are developed by introducing carboxylated chitosan acting as a hydrogen-bondin donors as well as a soft interlocking agent (C-ANFs). As a result of the formation of a nanostructure and the hydrogen-bond interactions, the assembled C-ANF networks presented a high tensile strength (551.4 MPa) and toughness (4.0 MJ/m2), which is 2.41 times and 32.69 times those of neat ANF networks, respectively. The excellent mechanical properties endow C-ANF networks with distinguished anti-impact performance. The specific dissipated energy after mass normalization reaches 7.34 MJ/kg, which is significantly superior to traditional protective materials such as steel and Kevlar composites. A nonlinear spring model is also used to explain the mechanical behavior of C-ANF networks. In addition to anti-impact protection, C-ANF networks can realize more than 99% of UV irradiation absorption and have excellent thermal stability. The chemical stability of C-ANF networks make them survive in acid and alkali environments. The above characteristics show that C-ANF networks have great application value in multiscale protection scenarios under an extreme environment.

Influences of the Contact State between Friction Pairs on the Thermodynamic Characteristics of a Multi-Disc Clutch.

The relationship between clutch thermodynamic characteristics and contact states of friction components is explored numerically and experimentally. The clutch thermodynamic numerical model is developed with consideration of the contact state and oil film between friction pairs. The clutch bench test is conducted to verify the variation of the clutch thermodynamic characteristics from the uniform contact (UCS) to the intermittent contact (ICS). The results show that the oil film decreases gradually with increasing temperature; the lubrication state finally changes from hydrodynamic lubrication to dry friction, where the friction coefficient shows an increasing trend before a decrease. Thus, the friction torque in UCS gradually increases after the applied pressure stabilizes. When the contact state changes to ICS, the contact pressure increases suddenly and the oil film decreases rapidly in the local contact area, bringing about a sharp increase in friction torque; subsequently, the circumferential and radial temperature differences of friction components expand dramatically. However, if the contact zone is already in the dry friction state, friction torque declines directly, resulting in clutch failure. The conclusions can potentially be used for online monitoring and fault diagnosis of the clutch.

Stretchable and Recyclable Liquid Metal Droplets Embedded Elastomer Composite with High Mechanically Sensitive Conductivity.

Liquid metal (LM)-based elastomers have received growing interest for a wide range of applications such as soft robotics and flexible electronics. This work reports a stretchable and bendable liquid metal droplets embedded elastomer (LMDE) composite, which consists of liquid metal droplets (LMDs) filler and carbonyl iron particles (CIPs)/polydimethylsiloxane (PDMS) hybrid matrix. The reversible switching of the composite from an insulator to a conductor can be realized through the contact and noncontact process between the LMDs. The mechanism of constructing the controllable conductive path between the droplets under external deformations has been systematically studied, and this result also provides a basis model for analyzing the conductive networks in traditional LM-based flexible composites. The composites exhibit stable mechanical and electrical performance under different tensile strains and bending angles. Moreover, the fluidic nature of LM endows the composite with good electrically healing capability. The valuable LM can be easily recycled at a high recovery rate of 98%. Finally, the composite can be developed as a sensor for the detection of both compressive force and magnetic field, demonstrating a broad promising in flexible electronics, actuators, and wearable devices.

UGT1A1*6 mutation associated with the occurrence and severity in infants with prolonged jaundice.

Background: This study aimed to investigate the influence of a variant of the UGT1A1 gene on the occurrence and severity of prolonged jaundice in Chinese infants at term. Methods: 175 infants with prolonged jaundice and 149 controls were used in this retrospective case-control study. The infants with prolonged jaundice were subdivided into the mild-medium and severe jaundice groups (TSB ≥ 342 µmol/L). The frequency and genotype distribution of the UGT1A1 and G6PD genes, and clinical parameters including sex, birth weight, delivery mode, gestational age, and feeding mode, were analyzed, and the differences in the parameters between the two groups were compared. Results: The allele frequency of UGT1A1*6 in the prolonged jaundice group was higher than that in the control group. Similarly, it was also higher in the severe jaundice group than in the mild-medium jaundice group. Homozygous and heterozygous UGT1A1*6 were also found more frequently in the prolonged jaundice group than in the control group. Exclusive breastfeeding, homozygous and heterozygous forms of UGT1A1*6 were significant risk indicators for prolonged jaundice. Moreover, UGT1A1*6 was the best predictor of prolonged severe jaundice. Conclusion: UGT1A1*6 appears to be a risk factor for prolonged jaundice with hyperbilirubinemia in term infants of Chinese ancestry who are exclusively breastfed.

Sliding State Analysis of Fractal Rough Interface Based on the Finite Element Method.

Local high temperature, stress concentration, and abnormal friction coefficients will appear at the friction pair in a wet clutch as a result of surface topography real-time changing. In order to improve the reliability of clutch friction components and reduce the failure phenomenon, the three-dimensional fractal surface topography data of the actual rough surface asperities are scanned, extracted, and processed successively, and then the finite element model of the rotary sliding friction pair is established considering the micro surface topography. Based on the finite element model, the variation of surface stress and strain is analyzed, and the friction coefficient measured experimentally is taken as the model input. It is concluded that when the rough surface and smooth surface make contact with each other, the maximum stress and plastic strain appear at the inner radius edge. Therefore, this research has a guiding significance for the structural design and processing technology of the friction components in a vehicle clutch.

Preparation of Poly(glycidyl methacrylate) (PGMA) and Amine Modified PGMA Adsorbents for Purification of Glucosinolates from Cruciferous Plants.

Glucosinolates (GLs) are of great interest for their potential as antioxidant and anticancer compounds. In this study, macroporous crosslinked copolymer adsorbents of poly (glycidyl methacrylate) (PGMA) and its amine (ethylenediamine, diethylamine, triethylamine)-modified derivatives were prepared and used to purify the GLS glucoerucin in a crude extract obtained from a cruciferous plant. These four adsorbents were evaluated by comparing their adsorption/desorption and decolorization performance for the purification of glucoerucin from crude plant extracts. According to the results, the strongly basic triethylamine modified PGMA (PGMA-III) adsorbent showed the best adsorption and desorption capacity of glucoerucin, and its adsorption data was a good fit to the Freundlich isotherm model and pseudo-second-order kinetics; the PGMA adsorbent gave the optimum decolorization performance. Furthermore, dynamic adsorption/desorption experiments were carried out to optimize the purification process. Two glass columns were serially connected and respectively wet-packed with PGMA and PGMA-III adsorbents so that glucoerucin could be decolorized and isolated from crude extracts in one process. Compared with KCl solution, aqueous ammonia was a preferable desorption solvent for the purification of glucoerucin and overcame the challenges of desalination efficiency, residual methanol and high operation costs. The results showed that after desorption with 10% aqueous ammonia, the purity of isolated glucoerucin was 74.39% with a recovery of 80.63%; after decolorization with PGMA adsorbent, the appearance of glucoerucin was improved and the purity increased by 11.30%. The process of using serially connected glass columns, wet-packed with PGMA and PGMA-III, may provide a simple, low-cost, and efficient method for the purification of GLs from cruciferous plants.

Ellipsoidal magnetite nanoparticles: a new member of the magnetic-vortex nanoparticles family for efficient magnetic hyperthermia.

The development of magnetic iron oxide nanoparticles with novel topological magnetic domain structures, such as the vortex-domain structure, is a promising strategy for improving the application performance of conventional superparamagnetic iron oxides while maintaining their good biocompatibility. Here, we fabricated a new kind of magnetic-vortex nanoparticles, i.e., ellipsoidal magnetite nanoparticles (EMPs), for cancer magnetic hyperthermia. The magnetization configurations and switching behaviours of the EMPs were analyzed by analytical simulations and Lorentz TEM, demonstrating the magnetic vortex structures of both single and coupled EMPs. The EMP treatment of 4T1 cells exposed to an alternating magnetic field (AMF) induced a significant decrease in the cell viability by ∼51.5%, which indicated a much higher cytotoxic effect in comparison with commercial superparamagnetic iron oxides (Resovist, ∼12.0%). In addition, the in vivo high efficacy of 4T1 breast tumor inhibition was also achieved by using EMP-mediated magnetic hyperthermia. Our results not only provide a new type of magnetic-vortex nanoparticles for efficient hyperthermia but also enrich the family of magnetic iron oxide nanoparticles for various biomedical applications.

Human-like collagen protein-coated magnetic nanoparticles with high magnetic hyperthermia performance and improved biocompatibility.

Human-like collagen (HLC)-coated monodispersed superparamagnetic Fe3O4 nanoparticles have been successfully prepared to investigate its effect on heat induction property and cell toxicity. After coating of HLC, the sample shows a faster rate of temperature increase under an alternating magnetic field although it has a reduced saturation magnetization. This is most probably a result of the effective heat conduction and good colloid stability due to the high charge of HLC on the surface. In addition, compared with Fe3O4 nanoparticles before coating with HLC, HLC-coated Fe3O4 nanoparticles do not induce notable cytotoxic effect at higher concentration which indicates that HLC-coated Fe3O4 nanoparticles has improved biocompatibility. Our results clearly show that Fe3O4 nanoparticles after coating with HLC not only possess effective heat induction for cancer treatment but also have improved biocompatibility for biomedicine applications.

[Optical emission spectroscopy of MPCVD plasma].

The plasma of CH4/H2 was diagnosed with optical emission spectroscopy on a high-pressure microwave plasma apparatus at 2.45 GHz. The existing radicals in the plasma and the influence of the methane concentration on radical concentration and distribution were researched. The results indicate that the radicals of CH, Halpha, Hbeta, Hgamma, C2 and little impurity atom Mo exist in the plasma. The intensity of emission spectrum of the radicals increases with the increase in the methane concentration, especially the intensity of C2 has a notable increase. The ratio of the intensity of the CH to Halpha is unchanging with the increase in methane concentration, while that of C2 to Halpha has a marked increase. The uniformity of the space distribution of the radicals becomes worse with the increase in methane concentration.

Microwave frequency performance and high magnetic anisotropy of nanocrystalline Fe70Co30-B films prepared by composition gradient sputtering.

The fabrication and high-frequency ferromagnetic performances of nanocrystalline Fe70Co30-B soft magnetic films were investigated. It is revealed that the composition gradient sputtering method dramatically improves the high-frequency soft magnetic properties of the as-prepared films. This method gives rise to almost a linearly-increased distribution of compositions and residual stress. As a result, a very high ferromagnetic resonance frequency up to 6.7 GHz, high uniaxial magnetic anisotropic field up to 450 Oe, and low magnetic loss were obtained in as-deposited samples, which are particularly in favor of the integration between magnetic films and microwave components.

Nanoparticle-tethered NAD(+) with in situ cofactor regeneration.

A new and simple route for the preparation of immobilized NAD(+) on carboxyl-activated silica nanoparticles activated by γ-aminpropyltriethoxysilane and glutaric anhydride was developed. In addition, formate dehydrogenase, keto-reductase and the silica nanoparticle-attached NAD(+) were applied to catalyze the coupled reactions for production of L-lactate with the cofactor regenerated within the reaction cycle. As indicated by thermogravimetric analysis and FT-IR, the silica nanoparticles were successfully activated and the loading of carboxyl groups was 0.53 mmol g(-1) particle. The amount of immobilized NAD(+) on the support was 73 mg g(-1) particle. With 0.2 M pyruvate and 3 M formate, 0.16 M L-lactate was produced after the coupled reactions. The immobilized system showed excellent efficiency and stabilities in recycling, and it retained 60 % residual activity even after six reuses.

Effect of annealing on orientation of Bi 3.2 Sm 0.8 Ti 3 O 12 ferroelectric film prepared by sol-gel process.

Fatigue-free Bi(3.2)Sm(0.8)Ti(3)O(12) ferroelectric thin films were prepared on p-Si(100) substrate using a sol-gel deposition process. The formation and orientation of thin films were studied upon annealing conditions with XRD and SEM. Experiment results indicate that after preannealing at 400 degrees C for 10 min, annealing at 700 degrees C resulted in formation of strong a-axis oriented films. The orientation degree, I(200)/I(117), remarkably increases from 1.033 to 1.76 and 6.49 with increasing annealing time from 3 to 10 and 15 min respectively. However, only (117)-oriented films were produced by annealing films at 900 degrees C for 3 min without the preannealing.