Dynamic Monitoring of Biomolecular Hydrodynamic Dimensions by Magnetization Motion on Quartz Crystal Microbalance.

Hydrodynamic dimension (HD) is the primary indicator of the size of bioconjugated particles and biomolecules. It is an important parameter in the study of solid-liquid two-phase dynamics. HD dynamic monitoring is crucial for precise and customized medical research as it enables the investigation of the continuous changes in the physicochemical characteristics of biomolecules in response to external stimuli. However, current HD measurements based on Brownian motion, such as dynamic light scattering (DLS), are inadequate for meeting the polydisperse sample demands of dynamic monitoring. In this paper, we propose MMQCM method samples of various types and HD dynamic monitoring. An alternating magnetic field of frequency ωm excites biomolecule-magnetic bead particles (bioMBs) to generate magnetization motion, and the quartz crystal microbalance (QCM) senses this motion to provide HD dynamic monitoring. Specifically, the magnetization motion is modulated onto the thickness-shear oscillation of the QCM at the frequency ωq. By analysis of the frequency spectrum of the QCM output signal, the ratio of the magnitudes of the real and imaginary parts of the components at frequency ωq ± 2ωm is extracted to characterize the particle size. Using the MMQCM approach, we successfully evaluated the size of bioMBs with different biomolecule concentrations. The 30 min HD dynamic monitoring was implemented. An increase of ∼10 nm in size was observed upon biomolecular structural stretching. Subsequently, the size of bioMBs gradually reduced due to the continuous dissociation of biomolecules, with a total reduction of 20∼40 nm. This HD dynamic monitoring demonstrates that the release of biomolecules can be regulated by controlling the duration of magnetic stimulation, providing valuable insights and guidance for controlled drug release in personalized precision medicine.

Investigating links between Internet literacy, Internet use, and Internet addiction among Chinese youth and adolescents in the digital age.

Introduction: In current digital era, adolescents' Internet use has increased exponentially, with the Internet playing a more and more important role in their education and entertainment. However, due to the ongoing cognitive, emotion, and social development processes, youth and adolescents are more vulnerable to Internet addiction. Attention has been paid to the increased use of Internet during the COVID-19 pandemic and the influence of Internet literacy in prevention and intervention of Internet addiction. Methods: The present study proposes a conceptual model to investigate the links between Internet literacy, Internet use of different purpose and duration, and Internet addiction among Chinese youth and adolescents. In this study, N = 2,276 adolescents studying in primary and secondary schools in East China were recruited, and they completed self-reports on sociodemographic characteristics, Internet literacy scale, Internet use, and Internet addiction scale. Results: The results showed a significant relationship between Internet use and Internet addiction. To be specific, the duration of Internet use significantly and positively affected Internet addiction. With different dimensions of Internet literacy required, entertainment-oriented Internet use had positive impact on Internet addiction, while education-oriented Internet use exerted negative effects on Internet addiction. As for Internet literacy, knowledge and skills for Internet (positively) and Internet self-management (negatively) significantly influenced the likelihood of Internet addiction. Discussion: The findings suggest that Internet overuse increases the risk of Internet addiction in youth and adolescents, while entertainment-oriented rather than education-oriented Internet use is addictive. The role of Internet literacy is complicated, with critical Internet literacy preventing the development of Internet addiction among youth and adolescents, while functional Internet literacy increasing the risk.

Facile fabrication of N-doped hierarchical porous carbons derived from soft-templated ZIF-8 for enhanced adsorptive removal of tetracycline hydrochloride from water.

N-doped hierarchical porous carbons (NHPCs) were successfully prepared from soft-templated zeolitic imidazolate framework-8 (ZIF-8) precursors using sodium dodecylbenzene sulfonate (SDBS) as a template through facile one-step carbonization and applied in tetracycline hydrochloride (TCH) adsorption. The NHPC synthesized at 1000 °C with an SDBS/Zn2+ molar ratio of 0.075 exhibited the highest TCH adsorption (qm = 80.92 mg g-1) owing to its relatively large BET surface area (1067.41 m2 g-1) and pore volume (1.22 cm3 g-1) and the stronger surface interaction between TCH and NHPCs (HC1000-0.075). Compared with surfactant-free ZIF-8-derived carbon (HC), introduction of SDBS in the ZIF-8 precursor not only improved the pore structure of the carbon materials but also increased the nitrogen content and the number of surface functional groups. Adsorption kinetics and isotherms showed that the pseudo-second-order model and Sips model fit the TCH adsorption behavior on HC and HC1000-0.075 well. Adsorption experiments and characterizations revealed that the adsorption mechanism involved in TCH adsorption on HC1000-0.075 mainly depended on the synergistic effect of pore filling, H-bonding, π-π interactions, and weak electrostatic interactions. This study provides an effective and simple strategy for fabricating MOF-derived NHPCs as a promising adsorbent for the removal of antibiotics from water.

Efficient removal of tetracycline by a hierarchically porous ZIF-8 metal organic framework.

Most reported metal organic frameworks (MOFs) have microporous structures and defective active sites, limiting their practical application to macromolecular substances. A hierarchical porous zeolitic imidazolate framework-8 (ZIF-8) was prepared using poly(diallyldimethylammonium chloride) (PDDA) as a structure-directing agent under facile "aqueous room-temperature" conditions to increase the mass transfer and adsorption capacity tetracycline hydrochloride (TCH). The ZIF-8 pore structure and morphology were synchronously tuned by controlling the PDDA molecular weight and dosage. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Bruner-Emmett-Teller (BET), scanning electron microscopy (SEM), NH3-temperature-programmed desorption (NH3-TPD) and adsorption results revealed abundant pore structures and open metal sites in the prepared materials, along with excellent TCH adsorption performance compared with ZIF-8, despite decreased BET surface areas. Initial screens revealed large adsorption capacities of hierarchical porous ZIF-8P3(4) (976.8 mg g-1) due to the presence of more abundant unsaturated metal sites than ZIF-8 and novel hierarchical porous structures. Therefore, TCH adsorption on ZIF-8 and ZIF-8P3(4), including the kinetics, isotherms, thermodynamics and pH effect, was studied. The adsorption process follows pseudo-second-order kinetics and the Freundlich models better, indicating multilayer adsorption of TCH on the surface of the two absorbents. Adsorption behavior test, FTIR, XPS, BET and XRD results show that TCH adsorption on ZIF-8 and ZIF-8P3(4) most likely involves coordination bonds, electrostatic and π-π interactions, hydrogen bonds, and pore-filling effects. This study provides new insights into the template preparation of MOFs with high adsorption performance as potentially economical adsorbents to remove organic matter from contaminated water.

Factors Affecting College Students' Continuous Intention to Use Online Course Platform.

In recent years, online learning model has become the mainstream in higher education. The cooperation between universities and Internet education platforms provides a good learning environment and abundant online elective courses for college students, but the practical teaching effect is not ideal. Therefore, based on the Universal Theory of Acceptance and Use of Technology (UTAUT), this study introduced the perceived cost and content quality to build a model of college students' continuous intention to use online course platforms, and used structural equation model to study the relationship among the variables. The results showed that effort expectancy and social influence affected continuous intention indirectly via performance expectancy; content quality indirectly affected continuous intention through effort expectancy, performance expectancy and effort expectancy-performance expectancy; perceived cost had a significant negative effect on continuous intention. These research results provide new ideas for the design and development of online course platform.