Preparation of amphiphilic poly(divinylbenzene-co-N-vinylpyrrolidone)-functionalized polydopamine magnetic nanoadsorbents for enrichment of synthetic cannabinoids in wastewater.

Concerns have been raised about synthetic cannabinoids (SCs), which are among the most often trafficked and used illegal substances. An analytical method that holds promise for determining illicit drug use in the general population is wastewater-based epidemiology (WBE). Unfortunately, the concentration of SCs in wastewater is often extremely low on account of their hydrophobic nature, thus presenting a significant obstacle to the accurate detection and quantification of SCs using WBE. In this study, we present novel magnetic nanomaterials as amphiphilic adsorbents for pretreatment of wastewater using magnetic solid phase extraction (MSPE). Polydopamine-modified Fe3O4 nanoparticles were used as the magnetic core and further functionalized with poly(divinylbenzene-N-vinylpyrrolidone). Coupled with UHPLC-MS/MS analysis, an analytical method to simultaneously detect nine SCs at trace-levels in wastewater was developed and validated, enriching 50 mL wastewater to 100 µL with limits of detection (LOD) being 0.005-0.5 ng L-1, limits of quantification (LOQ) being 0.01-1.0 ng L-1, recoveries ranging from 73.99 to 110.72%, and the intra- and inter-day precision's relative standard deviations less than 15%. In comparison to the time-consuming conventional column-based solid phase extraction, the entire MSPE procedure from sample pre-treatment to data acquisition could be finished in one hour, thus largely facilitating the WBE method for drug surveillance and control.

Imaging GPCR Dimerization in Living Cells with Cucurbit[7]uril and Hemicyanine as a "Turn-On" Fluorescence Probe.

Although multiple forms of dimers have been described for GPCR, their dynamics and function are still controversially discussed field. Fluorescence microscopy allows GPCR to be imaged within their native context; however, a key challenge is to site-specifically incorporate reporter moieties that can produce high-quality signals upon formation of GPCR dimers. To this end, we propose a supramolecular sensor approach to detect agonist-induced dimer formation of µ-opioid receptors (µORs) at the surface of intact cells. With the macrocyclic host cucurbit[7]uril and its guest hemicyanine dye tethered to aptamer strands directed against the histidine residues, the sensing module is assembled by host-guest complexation once the histidine-tagged µORs dimerize and bring the discrete supramolecular units into close proximity. With the enhanced sensitivity attributed by the "turn-on" fluorescence emission and high specificity afforded by the intermolecular recognition, in situ visualization of dynamic GPCR dimerization was realized with high precision, thereby validating the supramolecular sensing entity as a sophisticated and versatile strategy to investigate GPCR dimers, which represent an obvious therapeutic target.

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics.

In order to solve a series of problems with kelp drying including long drying time, high energy consumption, low drying efficiency, and poor quality of dried kelp, this work proposes the design of a novel greenhouse double-evaporator solar-assisted heat pump drying system. Experiments on kelp solar-assisted heat pump drying (S-HP) and heat pump drying (HP) under the condition of irradiance of 100-700 W/m2 and a temperature of 30, 40, or 50 °C were conducted and their results were compared in terms of system performance, drying kinetics, and quality impact. The drying time was reduced with increasing irradiance or temperature. The coefficient of performance (COP) and specific moisture extraction rate (SMER) of S-HP were 3.590-6.810, and 1.660-3.725 kg/kW·h, respectively, roughly double those of HP when the temperatures are identical. The Deff of S-HP and HP were 5.431 × 10-11~11.316 × 10-11 m2/s, and 1.037 × 10-11~1.432 × 10-11 m2/s, respectively; additionally, solar radiation greatly improves Deff. The Page model almost perfectly described the changes in the moisture ratio of kelp by S-HP and HP with an inaccuracy of less than 5%. When the temperature was 40 °C and the irradiance was above 400 W/m2, the drying time of S-HP was only 3 h, and the dried kelp maintained the green color with a strong flavor and richness in mannitol. Meanwhile, the coefficient of performance was 6.810, the specific moisture extraction rate was 3.725 kg/kWh, and the energy consumption was 45.2%, lower than that of HP. It can be concluded that S-HP is highly efficient and energy-saving for macroalgae drying and can serve as an alternate technique for the drying of other aquatic products.

A self-oscillating gel system with complex dynamic behavior based on a time delay between the oscillations.

The time delay existing between the chemical oscillation and mechanical oscillation (C-M delay) in a self-oscillating gel (SOG) system is observable in previous experimental studies. However, how the C-M delay affects the dynamic behavior of a large anisotropic SOG has not been quantified or reported systematically. In this study, we observed that the oscillation period increases with a decrease in the cross-linking density of the anisotropic SOG, and this determined whether regular mechanical oscillation occurs. Unlike before, the disrupted mechanical oscillations interestingly tend to be regular and periodic under visible light, which is an inhibitor for the B-Z reaction incorporating the Ru complex as a catalyst (Ru-BZ reaction). Moreover, the study of the C-M delay at different scales has far-reaching implications for intelligent soft actuators.

A dynamic self-regulation actuator combined double network gel with gradient structure driven by chemical oscillating reaction.

Self-regulation of the dynamic actuation of a chemical oscillating reaction-based gel was realized by altering the network structure of the gradient double network gel. We demonstrated that the propagation mode of the chemical wave was influenced by the network structure, and consequently determined the dynamic feature of the gel actuator.

A self-deformable gel system with asymmetric shape change based on a gradient structure.

A self-deformable gel system is constructed by coupling a gradient structured gel with a chemical oscillating reaction. The system exhibits periodic and asymmetric shape change. The asymmetric shape change of the gel is based on the gradient structure.

Microstructure and mechanical property of Ruditapes philippinarum shell.

In order to provide reference for the development of relevant dredging and processing machinery of the manila clam (Ruditapes philippinarum), the clam shell´s microstructure, phase composition, microhardness, nanoindentation hardness and elastic modulus were investigated, the quasi static compression and orthogonal compression tests of live clams were carried out as well. The shell consists of the outer, middle, and inner layer, which correspond with the composite prismatic structure, crossed-lamellar structure, and homogeneous structure, respectively. X-ray diffraction (XRD) results indicated that all the three layers are made up of pure aragonite phase, the outer layer of the shell displays greater intensity and more diffraction peaks than the middle and inner layer. The microhardness of the inner layer, ~ 3.00 GPa, is harder than the middle and outer layer. Both in the middle and outer layers, the microhardnesses of the vertical section perpendicular to the growth lines are obviously higher than that of the cross section parallel to the growth lines. The similar trend was observed in nanoindentation hardness (H) and elastic modulus (E), but the H/E ratios between three layers and two sections are close to 0.05. The quasi static compressive strengths of live clams with loading along the X (beak horizontal), Y (beak upward and umbo downward), and Z (beak vertical) orientations were tested, and the differences were identified. The lowest strength was found with loading orientation Z, the Weibull strength at 50% probabilities of fracture force is just 153 N. The results of the orthogonal compression tests demonstrated that the fracture force of clams varies from approximately 100 N to 400 N, the effect of the clams´â€¯age on fracture force is more significant (p < 0.01) than loading orientation and loading speed. Therefore, the clams´â€¯age and ultimate load of fracture should be taken into account during clam production mechanization, for the purpose of maintaining the clams´ integrity and survival prior to sale.