Search

To explore the key antibiofilm components of green Sichuan pepper essential oil (GPEO) against the spoilage microorganism Bacillus amyloliquefaciens and their intracellular targets, a molecular structure database of GPEO components and a collection of the molecule structures of target proteins related to the biofilm formation of B. amyloliquefaciens were created based on related literature data, and the CB-DOCK2 servicer was used to perform molecular docking of the active components of GPEO to biofilm formation-related target proteins. Furthermore, the key antibiofilm components of GPEO were selected based on their docking affinity and their potential targets were explored. Finally, in vitro experiments and crystal violet staining were conducted to confirm the antibiofilm effects of two key active components of GPEO, caryophyllene oxide and β-caryophyllene, against B. amyloliquefaciens. Molecular docking results showed that 24 volatile components of GPEO had different affinities to 58 targets associated with the biofilm formation of B. amyloliquefaciens, among which β-caryophyllene and caryophyllene oxide could tightly bind to ComP and RapC through intermolecular forces such as hyperconjugation, hydrophobic interaction and van der Waals force, forming a stable conformation. In vitro experiments showed that the minimal inhibitory concentrations (MICs) of caryophyllene oxide and β-caryophyllene against the biofilm of B. amyloliquefaciens were 6.0 and 2.0 mg/mL, respectively. Both compounds interfered with the swimming motility of this bacterium, reduced the initial cell adhesion and auto-aggregation ability, and altered the cell surface hydrophobicity. These results provide feasible strategies to help decipher the intracellular molecular mechanisms related to the biological activity of plant essential oil.

It is highly demanded to understand the confinement effect on nanoconfined polymers. Recent studies reported a strong perturbation of local dynamics and substantial alteration of glass transition temperature Tg at nanoscale. However, how confinement affects the mechanical properties of polymers is not fully understood. Here, we show that the modulus of thin polymer films could be remarkedly altered through a polymer–polymer interface. The modulus of a thin polystyrene (PS) film next to a polydimethylsiloxane (PDMS) was determined from the PS–PDMS bilayer bulging test. A series of experiments show that the modulus of PS can be increased up to 37%, when the modulus of the neighboring PDMS varies from 1.04 to 4.88 MPa. The results demonstrate a strong sensitivity of mechanical properties of thin polymers to the hard/soft environment, which we attribute to the change of high-mobility layer by the polymer–polymer interface. [ABSTRACT FROM AUTHOR]

The demand for applications, such as coatings, separation filters, and electronic packaging, has greatly driven the research of polymer films. At nanometer scale, mechanical properties of thin polymer films can significantly deviate from bulk. Despite outstanding progresses, there still lack deep discussions on nonlinear viscoelastic–viscoplastic response and their interactions under nanoconfinement. In this work, by conducting measurements via the bubble inflation method and modelling using Schapery and Perzyna equations, we demonstrate nonlinear viscoelastic–viscoplastic properties of freely standing thin polystyrene (PS) films. The results show the unchanged glassy compliance and the rubbery stiffening phenomenon for thin PS films, where the lower rubbery plateau in rubbery stiffening may originate from the induced molecular orientation by plastic deformation. With decreasing film thickness, viscosity and yield stress in viscoplasticity increase in an exponential and a linear trend, respectively, indicating the significant role of nanoconfinement effect on viscoplastic properties. These findings may reveal that there are many properties from linear viscoelasticity to nonlinear viscoelasticity–viscoplasticity that need to be explored and unveiled for sufficient understanding of the nanoconfinement effect on altering mechanical behavior of polymers. [ABSTRACT FROM AUTHOR]

Telemedicine has gained tremendous development during the COVID‐19 pandemic. With deblocking and opening, telemedicine accelerates the evolvution of the medical "snack community" and undermines the perception of medical students and staff, which promotes the incidence of psychosocial‐related disorders. Moreover, the inconsistent telemedicine adaptability between medical workers and patients aggravates the doctor–patient conflict due to the aging population and COVID‐19 squeal. Telemedicine is colliding with the national healthcare system, whose synchronization with conventional medical service is crucial to coordinate the relationship among medical payment, patient privacy and qualifications of clinicians. This study puts more emphasis on the double‐edged sword role of telemedicine in clinical practice and medical education during the COVID‐19 pandemic and beyond. Overall, while telemedicine has demonstrated its utility in health care throughout the COVID pandemic, it is pretty critical to continue evaluating the efficacy and limitations of telemedicine in order to maintain equal access to medical service and high‐quality medical education. A new concept as telemedicine‐medical "snack community"‐PHS ecosystem, where the psychological health education system and partners healthcare system with enough bandwidth, especially 5G technology, could optimize the effect of telemedicine on medical practice and education, is proposed. [ABSTRACT FROM AUTHOR]

Integration of hexagonal boron nitride (h-BN) with plasmonic nanostructures that possess nanoscale field confinement will enable unusual properties; hence, the manipulation and understanding of the light interactions are highly desirable. Here, we demonstrate the surface plasmonic coupling of Au nanoparticles (ANPs) with ultrathin h-BN nanosheets (BNNS) in nonspecific nanocomposites leading to a great enhancement of the Raman signal of E2g in both experimental and theoretical manner. The nanocomposites were fabricated from liquid-exfoliated atomically thin BNNS and diblock copolymer-based ANPs with excellent dispersion through a self-assembly approach. By precisely varying the size of ANPs from 3 to 9 nm, the Raman signal of BNNS was improved from 1.7 to 71. In addition, the underlying mechanism has been explored from the aspects of electromagnetic field coupling strength between the localized surface plasmons excited from ANPs and the surrounding dielectric h-BN layers, as well as the charge transfer at the BNNS/ANPs interfaces. Moreover, we also demonstrate its capability to detect dye molecules as a surface enhanced Raman scattering (SERS) substrate. This work provides a basis for the self-assembly of BNNS hierarchical nanocomposites allowing for plasmon-mediated modulation of their optoelectronic properties, thereby showing the great potential not only in the field of SERS but also in large-scale h-BN-based plasmonic devices. [ABSTRACT FROM AUTHOR]

Purpose: Meiotic nuclear division 1 (MND1) is a meiosis-specific protein that promotes lung adenocarcinoma progression. However, its expression and biological function across cancers remain largely unexplored. Patients and Methods: The expression, prognostic significance, mutation status, and methylation profile of MND1 in various cancers were comprehensively analyzed using the TIMER, GTEX, Kaplan-Meier plotter, cBioPortal, and GSCA databases. Additionally, we constructed a PPI network, enrichment analysis and single-cell transcriptomic sequencing to elucidate the underlying mechanism of MND1. Furthermore, we investigated the association between MND1 expression and drug sensitivity using CellMiner. Moreover, we also explored the correlation between MND1 expression and immune infiltration. Finally, we validated the functional role of MND1 in breast cancer through IHC staining, CCK8, EdU, colony formation, and flow cytometry assays. Results: MND1 has been reported to be highly expressed in Pan-cancer, High MND1 expression was significantly associated with poor prognosis in cancers. Additionally, MND1 mutation frequency is high in most cancers, and its expression correlates with methylation. Furthermore, MND1 expression significantly correlates with immune checkpoint blockade (ICB) markers, including PD-L1, PD-1, and CTLA-4. The PPI network reveals interactions between MND1 and PSMC3IP, BRCA1, and BRCA2. Enrichment analysis and single-cell sequencing indicate that MND1 positively correlates with cell cycle. ROC curve reveals favorable diagnostic efficacy of MND1 in breast cancer. In vitro, MND1 overexpression promotes breast cancer cell proliferation and increases the expression of key cell cycle regulators (CDK4, CDK6, and cyclin D3), accelerating the G1/S phase transition and leading to abnormal breast cancer cell proliferation. The immunohistochemical analysis revealed a robust expression of MND1 in breast cancer tissues, exhibiting a significant positive correlation with PD-L1 and FOXP3. Conclusion: MND1 is an oncogene and may serve as a biomarker for cancer prognosis and immunotherapy. Targeting MND1 may be a potential tumor treatment strategy. [ABSTRACT FROM AUTHOR]

A new sensorless speed control system for a fractional-order terminal non-singular sliding mode surface-mounted permanent magnet synchronous motor is proposed. The fractional terminal non-singular sliding mode surface, which can converge in finite time, is designed by combining the fractional-order control theory with the terminal attractor concept. Then, a new control rate is proposed to reduce system buffeting. Secondly, an adaptive back electromotive force filter is designed to reduce the harmonics in the sliding mode function estimation and improve the observation accuracy. In addition, the theoretical analysis of the designed system proves that the system can converge in a finite time. Then, a fraction-order phase-locked loop with variable factors is designed to make the system more capable of tracking the rotor. Finally, a simulation and experiment platform is built, and a comparison experiment is carried out, which proves that the designed algorithm has a stronger rotor position tracking ability and a better dynamic performance of the system. [ABSTRACT FROM AUTHOR]

Objective To investigate possible functional disorders of central auditory processing and language in school⁃age children with cleft palate through an assessment of the characteristics of the P300 and N400 event⁃related potentials (ERPs). Methods This study included 28 school⁃age children with cleft palate, aged 6 to 12 years, and 30 children without cleft palate as a control group. The P300 and N400 ERPs were selected as indexes of the central audi⁃ tory processing and language functions of children in both groups. The data were statistically compared between the two groups. Results Compared with the controls, the children with cleft palate showed a significantly prolonged P300 la⁃ tency (331.73 ± 14.94 ms vs. 348.64 ± 14.66 ms, P < 0.05) and a significantly decreased P300 amplitude (13.47 ± 2.24 μV vs. 12.07 ± 2.46 μV, P < 0.05). Similarly, the N400 latency of children with cleft palate was significantly prolonged compared to that of controls (431.07 ± 17.90 ms vs. 408.23 ± 18.04 ms, P < 0.05), and the N400 amplitude was signifi⁃ cantly decreased compared to that of controls (13.75 ± 2.12 μV vs. 15.17 ± 2.34 μV, P < 0.05). Conclusion School⁃ age children with cleft palate may have central auditory processing disorders and language dysfunctions.

Mechanically stable air cathodes with exceptional oxygen reduction reaction (ORR) activities serve as a highly significant component of metal–air batteries. Herein, we have proposed and prepared a porous air electrode consisting of well-dispersed Fe nanoparticles (Zn assisted formation) embedded in nitrogen-rich 3D carbon nanofibers (called Fe(Zn)–N–C) derived from Fe, Zn–metal–organic frameworks (MOFs) by a facile and scalable approach. The obtained Fe(Zn)–N–C with a distinctly continuous porous structure presented a comparable or even better performance than the commercial 20 wt% Pt/C and previously reported non-noble electrocatalysts for Zn–air batteries, which includes (1) effective in the universal-pH range (E1/2 = 0.86, 0.74, and 0.67 V in alkaline, acidic, and neutral media, respectively), (2) extremely high stability (∼85%, 80%, and 82% activity retention for 86 400 s in alkaline, acidic, and neutral media, respectively), (3) a high power density (193 and 48 mW cm−2 in alkaline and neutral media, respectively), and (4) an excellent specific capacity (800 and 688 mA h g−1 in alkaline and neutral media, respectively). This design strategy of porous non-precious metal-doped pH-universal ORR electrocatalysts could also be extended to fabricate other novel, stable, and easy-to-use multi-functional electrocatalysts for clean-energy technology. [ABSTRACT FROM AUTHOR]

Developing highly efficient earth‐abundant alternatives to traditional noble metal catalysts is essential for clean and sustainable energy‐conversion and energy‐storage technologies, yet still challenging in limited active sites and weak resistance to electrochemical corrosion. Herein, density‐functional theory calculations demonstrate that hexagonal boron nitride (h‐BN), albeit often being considered inert, can generate boron‐active radicals at defective sites by forming heterogeneous structures with graphene‐containing point vacancies, leading to a substantial electron delocalization and charge transfer, indicating a superior catalytic activity. Experimentally, the van der Waals heterostructure is rationally designed with h‐BN nanosheets (BNNs) anchored on reduced graphene oxide (rGO) as strongly coupled composite catalysts. Despite the poor conductivity in BN and lower catalytic activity in rGO, the created heterostructures demonstrate unexpected, improved oxygen evolution reaction (OER) activity with excellent stability in alkaline electrolyte. Qualitative analysis of the valence band offset and theoretical calculation reveal that the formation of heterostructures can significantly drive the electron transfer between C and B atoms near the vacancies across the interface and cause a half‐metallic property of BN, decreasing the free energy barrier of four‐electron OER kinetics. Herein, the synthetic schemes of h‐BNNs are guided as highly active metal‐free OER electrocatalysts. [ABSTRACT FROM AUTHOR]