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To effectively enhance the resource utilization of biomass waste and realize waste recycling, a novel acid-modified magnetic biomass spent tea leaves (NiFe2O4/STLs) was prepared via the pyrolysis and co-precipitation methods and employed to eliminate bivalent mercury (Hg(II)) from water bodies. The as-prepared NiFe2O4/STLs exhibited strong magnetic property of 35.36 emu g−1 and could be easily separated from water by applying a magnetic field. The adsorption of Hg(II) over NiFe2O4/STLs was achieved under the optimal conditions of pH = 8 and T = 30 °C, and the maximum adsorption capacity towards Hg(II) was 204.42 mg g−1 according to the response surface methodology optimization. The removal of Hg(II) over NiFe2O4/STLs primarily involved ion exchange, electrostatic attraction and chelation, following the pseudo-second-order kinetic and Langmuir models, and attributed to an exothermic reaction. In addition, the magnetic biomass NiFe2O4/STLs exhibited good regeneration capability and chemical and mechanical stability. The application results revealed that inorganic salt ions, the nitrogen fertilizer urea, humus and other impurities in four different actual water bodies (tap water, river water, lake water and the effluent of sewage treatment plant) had a little impact on the adsorption of Hg(II) over NiFe2O4/STLs. The as-obtained biomass adsorbent of NiFe2O4/STLs has good application value for the removal of the toxic element Hg(II) from water bodies. [ABSTRACT FROM AUTHOR]

The function of vascular endothelial cells (ECs) within the complex vascular microenvironment is typically modulated by biochemical cues, cell–cell interactions, and fluid shear stress. These regulatory factors play a crucial role in determining cell mechanical properties, such as elastic and shear moduli, which are important parameters for assessing cell status. However, most studies on the measurement of cell mechanical properties have been conducted in vitro, which is labor-intensive and time-consuming. Notably, many physiological factors are lacking in Petri dish culture compared with in vivo conditions, leading to inaccurate results and poor clinical relevance. Herein, we developed a multi-layer microfluidic chip that integrates dynamic cell culture, manipulation and dielectrophoretic in situ measurement of mechanical properties. Furthermore, we numerically and experimentally simulated the vascular microenvironment to investigate the effects of flow rate and tumor necrosis factor-alpha (TNF-α) on the Young's modulus of human umbilical vein endothelial cells (HUVECs). Results showed that greater fluid shear stress results in increased Young's modulus of HUVECs, suggesting the importance of hemodynamics in modulating the biomechanics of ECs. In contrast, TNF-α, an inflammation inducer, dramatically decreased HUVEC stiffness, demonstrating an adverse impact on the vascular endothelium. Blebbistatin, a cytoskeleton disruptor, significantly reduced the Young's modulus of HUVECs. In summary, the proposed vascular-mimetic dynamic culture and monitoring approach enables the physiological development of ECs in organ-on-a-chip microsystems for accurately and efficiently studying hemodynamics and pharmacological mechanisms underlying cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Flexible and conductive hydrogels have been widely used in the field of flexible wearable sensors. However, the traditional carbon-based composite hydrogel sensors tend to present weak adhesion and mechanical strength, limiting the sensitivity and reliability of practical applications. Here, a gum arabic-tackified reduced graphene oxide composite hydrogel is successfully fabricated. The introduction of gum arabic endows the hydrogel with high mechanical strength, and fatigue resistance, as well as robust adhesion on metal, plastic, glass, rubber, and skin. Furthermore, the reduced graphene oxide would improve the conductivity of hydrogels. As a result, the skin-attached hydrogel sensors featuring high sensitivity, fast response, and wide detection range were demonstrated for monitoring various mechanical stimuli and human motions. It is anticipated that the gum arabic-tackified skin-attached hydrogel sensors hold prospective applications in electronic skin, human–machine interfaces, and soft robotics. [ABSTRACT FROM AUTHOR]

Polyethyleneimine-modified Fe 3 O 4 nanoparticles (Fe 3 O 4 -PEI) were synthesized by the one-step co-precipitation method, and the resulting material was used to immobilize naringinase from the fermentation broth of Aspergillus niger FFCC uv-11. The immobilized naringinase activity could reach up to 690.74 U per g-support at the conditions of initial naringinase activity of 406.25 U mL -1 , immobilization time of 4 h, glutaraldehyde concentration of 40% (w/v), immobilization temperature of 35 °C, and pH value of 5.5, with naringinase-carrying rate and naringinase activity recovery of 92.93% and 20.89%, respectively. In addition, the immobilized naringinase exhibited good pH and temperature stability in a pH range of 3.5-6.0 and temperature range of 40-70 °C, and the optimal reaction pH and reaction temperature were optimized as 5.5 and 60 °C, respectively. Besides, the immobilized naringinase could maintain 60.58% of the original activity after 10 reuse cycles, indicating that the immobilized naringinase had good reusability. Furthermore, the immobilized naringinase also performed excellent storage stability, 87.52% of enzyme activity still remained as stored at 4 °C for one month. In conclusion, the Fe 3 O 4 -PEI could be considered as a promising support for naringinase immobilization, with the advantages of high enzyme activity loading, good reusability, storage stability and rapid recovery., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

In the face of complex water quality changes, the application of existing cationic polyacrylamide has been largely limited. In this study, a series of cationic polyacrylamides (TPADs) with excellent flocculation/dewatering performance and low dosage were synthesized through photocatalytic surface initiation using acrylamide (AM) and acryloyloxyethyl trimethylammonium chloride (DAC) as monomers and nano-TiO 2 as an initiator. Characterization using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance ( 1 H NMR) spectroscopy, thermogravimetric/differential scanning calorimetry (TG/DSC) and scanning electron microscopy (SEM) was used to analyze the structural and morphological properties of TPADs. The initiation mechanism was described and the study on the properties of TPADs shows that the initiation method could obtain the copolymer with extra-high intrinsic viscosity. Furthermore, the flocculation and dewatering performance of TPADs and PADs were investigated in the micro-polluted low turbidity water flocculation test and sludge dewatering test. The application experimental results indicated that TPADs showed satisfactory turbidity removal and sludge dewatering performance by virtue of strong charge neutralization and a bridging effect. The excellent flocculation/dewatering performance was attributed to the photocatalytic surface-initiated method and the nano-TiO 2 initiator. Therefore, it is expected to open up new initiation methods in the synthesis of polymeric flocculants for a broad variety of applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)