Search

In this paper, the steel structure system of the assembled building is studied, the box modular building stiffness matrix reduction is proposed, and the calculation method of nodal stiffness matrix reduction is proposed based on the concept of nodal degrees of freedom coalescence and substructure to make full use of the repeatability of the box unit to reduce the order of the matrix equilibrium equation. Then, an engineering profile and a comparison of the calculation results of reaction spectrum analysis are carried out for the assembled steel structure system, and studies on the distribution of overturning moments between the frame and core and the distribution of shear forces between the core and the frame are carried out. Lastly, the assembled steel structure system is examined for damage analysis. The results show that the total overturning moment between the box-type modular structure and the conventional structure differs by 5979.6 kN·m and 2.67% in the X-direction and by 4694 kN·m and 2.18% in the Y-direction. The quality and safety of construction projects can be guaranteed more reliably with the help of this study.

Calcium ions (Ca2+) play crucial roles as second messengers in living cells and are associated with the onset and development of chronic brain diseases, including epilepsy. Dynamic and real‐time imaging of extracellular calcium levels ([Ca2+]ex) in the brain holds great potential for identifying disease foci. Magnetic resonance imaging (MRI) is a powerful non‐invasive tool for Ca2+ imaging with unlimited depth penetration. However, current available Ca2+ MR sensors lack the sensitivity to monitor small [Ca2+]ex alterations associated with chronic brain diseases in vivo. In this study, a highly sensitive Ca2+‐dependent T2‐T1 switchable magnetic nanosensor is reported, consisting of Ca2+‐specific ligands engineered near‐paramagnetic iron oxide nanoparticles. Surface ligand modifications can be adjusted to regulate the interaction energy between sensors and Ca2+, allowing for customizable response range and sensitivity to fulfill the in vivo imaging requirements. The optimized sensors enable non‐invasive visualization of early‐stage seizure focus in mice undergoing epilepsy. [ABSTRACT FROM AUTHOR]

Ultra‐high field (UHF) magnetic resonance imaging (MRI) has emerged as a focal point of interest in the field of cancer diagnosis. Despite the ability of current paramagnetic or superparamagnetic smart MRI contrast agents to selectively enhance tumor signals in low‐field MRI, their effectiveness at UHF remains inadequate due to inherent magnetism. Here, we report a ligand‐mediated magnetism‐conversion nanoprobe (MCNP) composed of 3‐mercaptopropionic acid ligand‐coated silver‐gadolinium bimetallic nanoparticles. The MCNP exhibits a pH‐dependent magnetism conversion from ferromagnetism to diamagnetism, facilitating tunable nanomagnetism for pH‐activatable UHF MRI. Under neutral pH, the thiolate (−S−) ligands lead to short τ′m and increased magnetization of the MCNPs. Conversely, in the acidic tumor microenvironment, the thiolate ligands are protonated and transform into thiol (−SH) ligands, resulting in prolonged τ′m and decreased magnetization of the MCNP, thereby enhancing longitudinal relaxivity (r1) values at UHF MRI. Notably, under a 9 T MRI field, the pH‐sensitive changes in Ag−S binding affinity of the MCNP lead to a remarkable (>10‐fold) r1 increase in an acidic medium (pH 5.0). In vivo studies demonstrate the capability of MCNPs to amplify MRI signal of hepatic tumors, suggesting their potential as a next‐generation UHF‐tailored smart MRI contrast agent. [ABSTRACT FROM AUTHOR]

Targeted assembly of nanoparticles in biological systems holds great promise for disease-specific imaging and therapy. However, the current manipulation of nanoparticle dynamics is primarily limited to organic pericyclic reactions, which necessitate the introduction of synthetic functional groups as bioorthogonal handles on the nanoparticles, leading to complex and laborious design processes. Here, we report the synthesis of tyrosine (Tyr)-modified peptides-capped iodine (I) doped CuS nanoparticles (CuS-I@P1 NPs) as self-catalytic building blocks that undergo self-propelled assembly inside tumour cells via Tyr-Tyr condensation reactions catalyzed by the nanoparticles themselves. Upon cellular internalization, the CuS-I@P1 NPs undergo furin-guided condensation reactions, leading to the formation of CuS-I nanoparticle assemblies through dityrosine bond. The tumour-specific furin-instructed intracellular assembly of CuS-I NPs exhibits activatable dual-modal imaging capability and enhanced photothermal effect, enabling highly efficient imaging and therapy of tumours. The robust nanoparticle self-catalysis-regulated in situ assembly, facilitated by natural handles, offers the advantages of convenient fabrication, high reaction specificity, and biocompatibility, representing a generalizable strategy for target-specific activatable biomedical imaging and therapy. In vivo manipulation of the dynamics of nanoparticles' is essential for disease-specific imaging and therapy, but tends to involve complex design processes. Here, the authors report a strategy for manipulating the assembly of nanoparticles in vivo through a self-catalysis-instructed dimerization of tyrosine, offering convenient fabrication, high reaction specificity and biocompatibility. [ABSTRACT FROM AUTHOR]

Herein, a novel electrochemical sensor for glucose and hydrogen peroxide (H2O2) detection was successfully developed through the use of Cu nanoflowers (CuNFs) combined with flexible carbon cloth (CC) substrate. The 3D flower‐like CuNFs in size uniformly and firmly grow on CC substrate by a facile, scalable, one‐step hydrothermal strategy. Morphology, size and surface property of the prepared CuNFs/CC were examined by SEM, EDS and TEM, respectively. The electrochemical mechanism of CuNFs/CC for glucose and H2O2 detection was investigated by cyclic voltammetry. High electrochemical performances were displayed with amperometric i‐t curves including a wide linear range from 1.0 nM to 6.0 mM for glucose and from 1.0 μM to 36.66 mM for H2O2, respectively. Good sensitivity, repeatability, and stability, as well as anti‐interference ability, the carbon cloth‐supported CuNFs will be the promising materials for fabricating practical non‐enzymatic glucose and H2O2 sensors. [ABSTRACT FROM AUTHOR]

Herein, a novel electrochemical sensor for glucose and hydrogen peroxide (H2O2) detection was successfully developed through the use of Cu nanoflowers (CuNFs) combined with flexible carbon cloth (CC) substrate. The 3D flower‐like CuNFs in size uniformly and firmly grow on CC substrate by a facile, scalable, one‐step hydrothermal strategy. Morphology, size and surface property of the prepared CuNFs/CC were examined by SEM, EDS and TEM, respectively. The electrochemical mechanism of CuNFs/CC for glucose and H2O2 detection was investigated by cyclic voltammetry. High electrochemical performances were displayed with amperometric i‐t curves including a wide linear range from 1.0 nM to 6.0 mM for glucose and from 1.0 μM to 36.66 mM for H2O2, respectively. Good sensitivity, repeatability, and stability, as well as anti‐interference ability, the carbon cloth‐supported CuNFs will be the promising materials for fabricating practical non‐enzymatic glucose and H2O2 sensors. [ABSTRACT FROM AUTHOR]

Hair-related disorders are currently widely concerned issues for not only the scientific society but also the public attentions. Microneedle-based drug delivery system has been regarded as a promise hair follicle-targeted drug delivery approach, largely because they can effectively penetrate the stratum corneum barrier and deliver drugs to hair follicles within dermis. However, the currently reported microneedles for treating hair-related disorders usually rely on rigid backings, showing poor adaptability to the curved scalp and thereby restricting their usability for hair follicles targeted drug delivery. To this end, this study utilized sodium alginate and polyvinylpyrrolidone to construct a scalp-curvature-conforming microneedle with flexible backing. Subsequently, Psoralea corylifolia extract (PE) was loaded into the microneedles to investigate its capability in delivering PE to the hair follicle site for treating leukotrichia associated with vitiligo. These PE-loaded microneedles can effectively conform to the curvature of skin, enhancing the efficiency of microneedle insertion and ensuring stable drug delivery. Moreover, animal studies demonstrate that the PE loaded microneedles can effectively penetrate the stratum corneum, benefiting the drug delivery to hair follicles located site, and consequently showing a successful inhibition of hair graying. In summary, the present study reports a design and preparation of scalp-curvature-conforming microneedle. This design may offer a potential solution for efficient drug delivery using microneedles to the curved skin., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in the manuscript entitled “Curvature-Adaptive Microneedles Based on Sodium Alginate and Polyvinylpyrrolidone for Efficient Drug Delivery to Hair Follicles for Hair Recoloration”., (Copyright © 2024. Published by Elsevier B.V.)

Ultra-high field (UHF) magnetic resonance imaging (MRI) has emerged as a focal point of interest in the field of cancer diagnosis. Despite the ability of current paramagnetic or superparamagnetic smart MRI contrast agents to selectively enhance tumor signals in low-field MRI, their effectiveness at UHF remains inadequate due to inherent magnetism. Here, we report a ligand-mediated magnetism-conversion nanoprobe (MCNP) composed of 3-mercaptopropionic acid ligand-coated silver-gadolinium bimetallic nanoparticles. The MCNP exhibits a pH-dependent magnetism conversion from ferromagnetism to diamagnetism, facilitating tunable nanomagnetism for pH-activatable UHF MRI. Under neutral pH, the thiolate (-S - ) ligands lead to short τ' m and increased magnetization of the MCNPs. Conversely, in the acidic tumor microenvironment, the thiolate ligands are protonated and transform into thiol (-SH) ligands, resulting in prolonged τ' m and decreased magnetization of the MCNP, thereby enhancing longitudinal relaxivity (r1) values at UHF MRI. Notably, under a 9 T MRI field, the pH-sensitive changes in Ag-S binding affinity of the MCNP lead to a remarkable (>10-fold) r1 increase in an acidic medium (pH 5.0). In vivo studies demonstrate the capability of MCNPs to amplify MRI signal of hepatic tumors, suggesting their potential as a next-generation UHF-tailored smart MRI contrast agent., (© 2024 Wiley-VCH GmbH.)