[Research Progress in Electrochemical Detection and Removal of Micro/Nano Plastics in Water].

Micro/nano plastics （M/NPs） are widely dispersed in the soil， atmosphere， and water environment due to their small particle size， easy adsorption， and strong migration， and have been detected in all major water bodies in recent years. As a type of emerging pollutant， the physiological toxicity of M/NPs has a great impact on human health. The current bottleneck in this research field lies in the precise detection and efficient removal of M/NPs. Electrochemical technology， owing to its advantages of simple portability， sensitivity， and low cost in the detection of M/NPs， has the advantages of environmental friendliness， controllable reaction， and high efficiency in the removal of M/NPs， demonstrating enormous application potential. Based on the pollution status of M/NPs， the application of electrochemical technology to the detection and removal of M/NPs in the water environment was elaborated and summarized. The electrochemical sensing methods of M/NPs and the principles and characteristics of sensor recognition of M/NPs were analyzed. The removal efficiency and influencing factors of M/NPs in water by electro-flocculation， electro-adsorption， electro-oxidation， and electro-reduction technologies were also discussed. The results indicated that the detection of M/NPs particles using electrochemical sensing methods exhibited good characterization performance， and M/NPs could be efficiently removed through electrochemical techniques such as electrocoagulation， electro-adsorption， electro-oxidation， and electro-reduction. The influencing factors of electrochemical technology on the detection and removal of M/NPs were mainly related to sensor devices， electrode materials， material interface regulation， parameter conditions， and reactor systems. In the future， researchers should focus on the design of sensors， the development of electrode materials， and the optimization of reaction processes， which are expected to realize the application of M/NPs from laboratory detection and removal to actual water bodies.

Recent Advances of Chitosan-Based Hydrogels for Skin-Wound Dressings.

The management of wound healing represents a significant clinical challenge due to the complicated processes involved. Chitosan has remarkable properties that effectively prevent certain microorganisms from entering the body and positively influence both red blood cell aggregation and platelet adhesion and aggregation in the bloodstream, resulting in a favorable hemostatic outcome. In recent years, chitosan-based hydrogels have been widely used as wound dressings due to their biodegradability, biocompatibility, safety, non-toxicity, bioadhesiveness, and soft texture resembling the extracellular matrix. This article first summarizes an overview of the main chemical modifications of chitosan for wound dressings and then reviews the desired properties of chitosan-based hydrogel dressings. The applications of chitosan-based hydrogels in wound healing, including burn wounds, surgical wounds, infected wounds, and diabetic wounds are then discussed. Finally, future prospects for chitosan-based hydrogels as wound dressings are discussed. It is anticipated that this review will form a basis for the development of a range of chitosan-based hydrogel dressings for clinical treatment.

Identification of inflammation-related biomarkers in keloids.

Background: The relationship between inflammation-related genes (IRGs) and keloid disease (KD) is currently unclear. The aim of this study was to identify a new set of inflammation-related biomarkers in KD. Methods: GSE145725 and GSE7890 datasets were used in this study. A list of 3026 IRGs was obtained from the Molecular Signatures Database. Differentially expressed inflammation-related genes (DEGs) were obtained by taking the intersection of DEGs between KD and control samples and the list of IRGs. Candidate genes were selected using least absolute shrinkage and selection operator (LASSO) regression analysis. Candidate genes with consistent expression differences between KD and control in both GSE145725 and GSE7890 datasets were screened as biomarkers. An alignment diagram was constructed and validated, and in silico immune infiltration analysis and drug prediction were performed. Finally, RT-qPCR was performed on KD samples to analyze the expression of the identified biomarkers. Results: A total of 889 DEGs were identified from the GSE145725 dataset, 169 of which were IRGs. Three candidate genes (TRIM32, LPAR1 and FOXF1) were identified by the LASSO regression analysis, and expression validation analysis suggested that FOXF1 and LPAR1 were down-regulated in KD samples and TRIM32 was up-regulated. All three candidate genes had consistent changes in expression in both the GSE145725 and GSE7890 datasets. An alignment diagram was constructed to predict KD. Effector memory CD4 T cells, T follicular helper cell, Myeloid derived suppressor cell, activated dendritic cell, Immature dendritic cell and Monocyte were differentially expressed between the KD and control group. Sixty-seven compounds that may act on FOXF1, 108 compounds that may act on LPAR1 and 56 compounds that may act on TRIM32 were predicted. Finally, RT-qPCR showed that the expression of LPAR1 was significantly lower in KD samples compared to normal samples whereas TRIM32 was significantly higher, while there was no difference in the expression of FOXF1. Conclusion: This study provides a new perspective to study the relationship between IRGs and KD.

Adsorption performance of nanoplastics in carbon filtration column.

Nanoplastics (NPs) are usually formed by the decomposition of large plastics, which will cause water pollution after entering the water body. Carbon filter column is used to adsorb and remove polystyrene nanoparticles (PSNPs). The influence of experimental conditions on adsorption was investigated and fitted by kinetic model. The results show that increasing the height of carbon filter column and decreasing the initial concentration of PSNPs and water flow rate can prolong the breakthrough time of carbon filter column. When the initial concentration of PSNPs is 0.8 mg L-1, the influent flow rate is 4 mL min-1 and the height of carbon filter bed is 8.5 cm, the removal effect is the best, and the depletion point of carbon filter column is extended to 48 h. Adams-Bohart model is suitable for describing the initial stage of adsorption. Thomas and Yoon-Nelson models can well describe the whole dynamic adsorption process of PSNPs, and Yoon-Nelson model can accurately predict the time required for 50% PSNPs to penetrate the carbon column. The adsorption mechanism of NPs by carbon filter column is mainly through the attachment sites and pore retention provided by particles on the surface of activated carbon. This study can provide new technical and theoretical support for the removal of NPs.

Effective degradation of polystyrene microplastics by Ti/La/Co-Sb-SnO2 anodes: Enhanced electrocatalytic stability and electrode lifespan.

Microplastics have been identified as an emerging pollutant that poses a risk to the aquatic environment, and it is a challenge to find a suitable removal process. Electrocatalytic oxidation (ECO) technology has shown promising performance in removing various persistent organic pollutants. In this study, we prepared a new anode for removing polystyrene microplastics (PS MPs) by ECO. Ti/La-Sb-SnO2 electrodes doped with the rare earth element La as the active layer were synthesized to enhance the electrocatalytic activity. The lifespan of the electrode was improved by doping Mn, Co, or Ru as an intermediate layer modification between the titanium (Ti) substrate and the La-Sb-SnO2 active layer, respectively. The experimental results indicated that the addition of three types of intermediate layers led to different degrees of decrease in the catalytic activity of the electrode and the degradation performance of PS MPs. The addition of the Co intermediate layer had a negligible effect on the catalytic activity and performance of the Ti/La-Sb-SnO2 anode for PS degradation. In addition, the electrode lifespan with Co intermediate layer was significantly prolonged, which was 4.54, 2.38, and 1.19 times higher than the electrode without intermediate layer and the electrode with Ru and Mn intermediate layer, respectively. Therefore, Co was determined to be the optimal choice as the intermediate layer, and the production technique for the Ti/La/Co-Sb-SnO2 anodes was carefully adjusted. The degradation efficiency of PS MPs was optimized at a heat treatment temperature of 400 °C and a Sn: Co material ratio of 5:1, with a removal rate of 28.0 %. The ECO treatment also resulted in more pronounced changes in the structure and functional groups of the MPs. Various alkyl cleavage and oxidation products were detected after the treatment, suggesting that the oxidant (hydroxyl radicals) strongly interacted with the MPs, leading to their degradation. Overall, this work provided a new insight into removing MPs in water through the use of modified electrodes.

A Sandwich Structure Ag/MgFe2 O4 -Deposited Surface Carbonized Wood for Integrated Solar Steam Generation and Photoreduction of Cr(VI).

The severe deterioration of the marine ecosystem significantly negatively impacts the performance of solar-driven steam generation (SSG) and the quality of the obtained freshwater. Herein, a bifunctional Ag/MgFe2 O4 @SCW reactor with a sandwich structure is designed for efficient SSG and Cr(VI) reduction, which is constructed via in situ deposit Ag nanoparticles (NPs) and MgFe2 O4 onto surface carbonized wood (SCW). Owing to the advanced sandwich structure and strong interfacial interactions between each component, an ultra-high evaporation rate of 1.55 kg m-2 h-1 and the efficiency of 88.6% are achieved using Ag/MgFe2 O4 @SCW under 1 sun. The system exhibits the long-term evaporation performance in the simulated sewage and strong acid/base solutions along with water-harvesting capacity in outdoor solar desalination. The quality of distilled water after desalination of actual seawater and NaCl solutions with different concentrations meets the WHO-recommended drinkable water standards. Furthermore, Ag/MgFe2 O4 @SCW shows outstanding antibacterial property, self-desalting capacity, as well as reusability and structure stability. Most importantly, the fast carrier separation endows Ag/MgFe2 O4 @SCW with superior photocatalytic activity and Cr(VI) photoreduction of up to 96.1% after 180 min of illumination. The bifunctional Ag/MgFe2 O4 @SCW reactor provides an advanced synergistic mechanism for improving SSG and photocatalytic performance, while being promising for solar-powered production of clean water.

Characterization of risks and pathogenesis of respiratory diseases caused by rural atmospheric PM2.5.

Forty-six percent of the world's population resides in rural areas, the majority of whom belong to vulnerable groups. They mainly use cheap solid fuels for cooking and heating, which release a large amount of PM2.5 and cause adverse effects to human health. PM2.5 exhibits urban-rural differences in its health risk to the respiratory system. However, the majority of research on this issue has focused on respiratory diseases induced by atmospheric PM2.5 in urban areas, while rural areas have been ignored for a long time, especially the pathogenesis of respiratory diseases. This is not helpful for promoting environmental equity to aid vulnerable groups under PM2.5 pollution. Thus, this study focuses on rural atmospheric PM2.5 in terms of its chemical components, toxicological effects, respiratory disease types, and pathogenesis, represented by PM2.5 from rural areas in the Sichuan Basin, China (Rural SC-PM2.5). In this study, organic carbon is the most significant component of Rural SC-PM2.5. Rural SC-PM2.5 significantly induces cytotoxicity, oxidative stress, and inflammatory response. Based on multiomics, bioinformatics, and molecular biology, Rural SC-PM2.5 inhibits ribonucleotide reductase regulatory subunit M2 (RRM2) to disrupt the cell cycle, impede DNA replication, and ultimately inhibit lung cell proliferation. Furthermore, this study supplements and supports the epidemic investigation. Through an analysis of the transcriptome and human disease database, it is found that Rural SC-PM2.5 may mainly involve pulmonary hypertension, sarcoidosis, and interstitial lung diseases; in particular, congenital diseases may be ignored by epidemiological surveys in rural areas, including tracheoesophageal fistula, submucous cleft of the hard palate, and congenital hypoplasia of the lung. This study contributes to a greater scientific understanding of the health risks posed by rural PM2.5, elucidates the pathogenesis of respiratory diseases, clarifies the types of respiratory diseases, and promotes environmental equity.

Mitigation of reverse osmosis membrane fouling by coagulation pretreatment to remove silica and transparent exopolymer particles.

The dissolution of silica and transparent exopolymer particles (TEP) can deposit on the membrane surface and cause serious membrane fouling in reverse osmosis (RO) technology. Coagulation, as a common pretreatment process for RO, can effectively intercept pollutants and alleviate membrane fouling. In this study, FeCl3 and AlCl3 coagulants and polyacrylamide (PAM) flocculants were used to explore the optimal coagulation conditions to reduce the concentration of silica and TEP in the RO process. The results showed that the two coagulants had the best removal effect on pollutants when the pH was 7 and the dosage was 50 mg/L. Considering the proportion of reversible fouling after coagulation, the removal rate of pollutants, and the residual amount of coagulation metal ions, the best PAM dosage was 5 mg/L for FeCl3 and 1 mg/L for AlCl3. After coagulation pretreatment, the Zeta potential decreased, and the particle size distribution increased, making pollutants tend to aggregate, thus effectively removing foulants. The removal mechanisms of pollutants by coagulation pretreatment were determined to be adsorption, electric neutralization and co-precipitation. This study determined the best removal conditions of silica and TEP by coagulation and explored the removal mechanism.

Inhibitory effects of phthalate esters (PAEs) and phthalate monoesters towards human carboxylesterases (CESs).

Phthalate esters (PAEs), accompanied by phthalate monoesters as hydrolysis metabolites in humans, have been widely used as plasticizers and exhibited disruptive effects on the endocrine and metabolic systems. The present study aims to investigate the inhibition behavior of PAEs and phthalate monoesters on the activity of the important hydrolytic enzymes, carboxylesterases (CESs), to elucidate the toxicity mechanism from a new perspective. The results showed significant inhibition on CES1 and CES2 by most PAEs, but not by phthalate monoesters, above which the activity of CES1 was strongly inhibited by DCHP, DEHP, DiOP, DiPP, DNP, DPP and BBZP, with inhibition ratios exceeding 80%. Kinetic analyses and in vitro-in vivo extrapolation were conducted, revealing that PAEs have the potential to disrupt the metabolism of endogenous substances catalyzed by CES1 in vivo. Molecular docking results revealed that hydrogen bonds and hydrophobic contacts formed by ester bonds contributed to the interaction of PAEs towards CES1. These findings will be beneficial for understanding the adverse effect of PAEs and phthalate monoesters.

Effect of hydrocolloid dressings on preventing air leakage when applying negative pressure wound therapy to the perineum, buttocks, and sacrococcygeal region.

Maintaining a vacuum when applying negative pressure wound therapy (NPWT) is the key to its function, which is a challenge in the perineum, buttocks, and sacrococcygeal region. A retrospective cohort study was conducted to assess the effect of hydrocolloid dressings on preventing air leakage when applying NPWT in these regions. There were 61 patients in Group A (without the aid of hydrocolloid dressings) and 65 patients in Group B (with the aid of hydrocolloid dressings). The hydrocolloid dressing-assisted NPWT significantly reduced the incidence of air leakage compared with conventional NPWT placement (24.6% vs. 7.7%; risk ratio, 3.20; 95% confidence interval, 1.24-8.27; p = 0.009), while decreasing the number of open NPWT applications (2.2 vs. 1.7; difference, 0.43; 95% confidence interval, 0.19-0.66; p < 0.001), shortening hospital stays (20.1 vs. 16.1; difference, 4.07; 95% confidence interval, 1.68-6.46; p = 0.01), and reducing the incidence of adverse skin events (18.0% vs. 4.6%; risk ratio, 3.91; 95% confidence interval, 1.14-13.34; p = 0.017). These findings support the routine use of hydrocolloid dressing-assisted NPWT placement in the perineum, buttocks, and sacrococcygeal region.

MFF-Net: Multiscale feature fusion semantic segmentation network for intracranial surgical instruments.

BACKGROUND: In robot-assisted surgery, automatic segmentation of surgical instrument images is crucial for surgical safety. The proposed method addresses challenges in the craniotomy environment, such as occlusion and illumination, through an efficient surgical instrument segmentation network. METHODS: The network uses YOLOv8 as the target detection framework and integrates a semantic segmentation head to achieve detection and segmentation capabilities. A concatenation of multi-channel feature maps is designed to enhance model generalisation by fusing deep and shallow features. The innovative GBC2f module ensures the lightweight of the network and the ability to capture global information. RESULTS: Experimental validation of the intracranial glioma surgical instrument dataset shows excellent performance: 94.9% MPA score, 89.9% MIoU value, and 126.6 FPS. CONCLUSIONS: According to the experimental results, the segmentation model proposed in this study has significant advantages over other state-of-the-art models. This provides a valuable reference for the further development of intelligent surgical robots.

Quantitative proteomics reveals the neurotoxicity of trimethyltin chloride on mitochondria in the hippocampus of mice.

Trimethyltin chloride (TMT) is a potent neurotoxin widely used as a constituent of polyvinyl chloride plastic in the industrial and agricultural fields. However, the underlying mechanisms by which TMT leads to neurotoxicity remain elusive. In the present study, we constructed a dose and time dependent neurotoxic mouse model of TMT exposure to explore the molecular mechanisms involved in TMT-induced neurological damage. Based on this model, the cognitive ability of TMT exposed mice was assessed by the Morris water maze test and a passive avoidance task. The ultrastructure of hippocampus was analyzed by the transmission electron microscope. Subsequently, proteomics integrated with bioinformatics and experimental verification were employed to reveal potential mechanisms of TMT-induced neurotoxicity. Gene ontology (GO) and pathway enrichment analysis were done by using Metascape and GeneCards database respectively. Our results demonstrated that TMT-exposed mice exhibited cognitive disorder, and mitochondrial respiratory chain abnormality of the hippocampus. Proteomics data showed that a total of 7303 proteins were identified in hippocampus of mice of which 224 ones displayed a 1.5-fold increase or decrease in TMT exposed mice compared with controls. Further analysis indicated that these proteins were mainly involved in tricarboxylic acid (TCA) cycle and respiratory electron transport, proteasome degradation, and multiple metabolic pathways as well as inflammatory signaling pathways. Some proteins, including succinate-CoA ligase subunit (Suclg1), NADH dehydrogenase subunit 5 (Nd5), NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 4-like 2 (Ndufa4l2) and cytochrome c oxidase assembly factor 7 (Coa7), which were closely related to mitochondrial respiratory electron transport, showed TMT dose and time dependent changes in the hippocampus of mice. Moreover, apoptotic molecules Bax and cleaved caspase-3 were up-regulated, while anti-apoptotic Bcl-2 was down-regulated compared with controls. In conclusion, our findings suggest that impairment of mitochondrial respiratory chain transport and promotion of apoptosis are the potential mechanisms of TMT induced hippocampus toxicity in mice.

InstrumentNet: An integrated model for real-time segmentation of intracranial surgical instruments.

In robot-assisted surgery, precise surgical instrument segmentation technology can provide accurate location and pose data for surgeons, helping them perform a series of surgical operations efficiently and safely. However, there are still some interfering factors, such as surgical instruments being covered by tissue, multiple surgical instruments interlacing with each other, and instrument shaking during surgery. To better address these issues, an effective surgical instrument segmentation network called InstrumentNet is proposed, which adopts YOLOv7 as the object detection framework to achieve a real-time detection solution. Specifically, a multiscale feature fusion network is constructed, which aims to avoid problems such as feature redundancy and feature loss and enhance the generalization ability. Furthermore, an adaptive feature-weighted fusion mechanism is introduced to regulate network learning and convergence. Finally, a semantic segmentation head is introduced to integrate the detection and segmentation functions, and a multitask learning loss function is specifically designed to optimize the surgical instrument segmentation performance. The proposed segmentation model is validated on a dataset of intracranial surgical instruments provided by seven experts from Beijing Tiantan Hospital and achieved an mAP score of 93.5 %, Dice score of 82.49 %, and MIoU score of 85.48 %, demonstrating its universality and superiority. The experimental results demonstrate that the proposed model achieves good segmentation performance on surgical instruments compared to other advanced models and can provide a reference for developing intelligent medical robots.

Nano-CeO2-Loaded Polyzwitterionic Double-Network High-Strength Hydrogel for Highly Enhanced Synergistic Marine Antifouling.

Although many antibiofouling materials have been developed based on either bacterial-killing or antiadhesion effects, the integration of both the effects in one material remains challenging for achieving highly enhanced synergistic antibiofouling. In this study, we have explored a nano-CeO2-loaded double-network hydrogel by introducing CeO2 nanorods into a polyzwitterionic hydrogel via a simple one-pot method for achieving highly efficient antifouling. First, the CeO2 nanorods dispersed in the hydrogel, as an outstanding nanozyme, have highly efficient bacterial-killing performance. Second, the superhydrophilic polyzwitterionic hydrogel provides a dense hydrated layer on the surface and subsequently excellent broad-spectrum antiadhesion behavior. Most importantly, the bacterial killing and antiadhesion of this hydrogel can work synergistically to largely improve the marine-antifouling performance. Moreover, the double-network structure of this hydrogel, including the covalently cross-linked polyzwitterion hard network and the physically cross-linked poly(vinyl alcohol) soft network, can provide greatly improved mechanical properties (2.44 MPa of tensile strength reaches and 21.87 MPa of compressive strength). As a result, among the existing marine-antifouling hydrogels, the CeO2-loaded polyzwitterionic double-network hydrogel can achieve outstanding antifouling performance, which can sustain for over 6 months in a real marine environment. This work provides a promising marine-antifouling hydrogel, which will also inspire antifouling research of a new strategy and materials.

Anisotropic Bi-Layer Hydrogel Actuator with pH-Responsive Color-Changing and Photothermal-Responsive Shape-Changing Bi-Functional Synergy.

Stimuli-responsive color-changing and shape-changing hydrogels are promising intelligent materials for visual detections and bio-inspired actuations, respectively. However, it is still an early stage to integrate the color-changing performance and shape-changing performance together to provide bi-functional synergistic biomimetic devices, which are difficult to design but will greatly expand further applications of intelligent hydrogels. Herein, we present an anisotropic bi-layer hydrogel by combining a pH-responsive rhodamine-B (RhB)-functionalized fluorescent hydrogel layer and a photothermal-responsive shape-changing melanin-added poly (N-isopropylacrylamide) (PNIPAM) hydrogel layer with fluorescent color-changing and shape-changing bi-functional synergy. This bi-layer hydrogel can obtain fast and complex actuations under irradiation with 808 nm near-infrared (NIR) light due to both the melanin-composited PNIPAM hydrogel with high efficiency of photothermal conversion and the anisotropic structure of this bi-hydrogel. Furthermore, the RhB-functionalized fluorescent hydrogel layer can provide rapid pH-responsive fluorescent color change, which can be integrated with NIR-responsive shape change to achieve bi-functional synergy. As a result, this bi-layer hydrogel can be designed using various biomimetic devices, which can show the actuating process in the dark for real-time tracking and even mimetic starfish to synchronously change both the color and shape. This work provides a new bi-layer hydrogel biomimetic actuator with color-changing and shape-changing bi-functional synergy, which will inspire new strategies for other intelligent composite materials and high-level biomimetic devices.

Nitric acid oxidation and urea modification of carbon fibres as biofilm carriers.

Carbon fibres (CF) are commonly used as carriers in biofilm-based wastewater treatment. The surface properties of the CF are herein modified using a combination of nitric acid oxidation and urea to optimise the carrier to immobilise bacterial cells. The capacity of the CF carriers to immobilise bacterial cells and activated sludge is evaluated using bacterial cell adhesion and sludge immobilisation tests. The total interaction energy profiles between the CF supports and bacterial cells were calculated according to the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to explain the mechanism by which these modifications enhance this immobilisation capacity. CF-U has a high capacity for immobilising bacterial cells and activated sludge (3.7 g-sludge/g-CF supports) owing to its low total interaction energy. Nitric acid oxidation reduced the diiodomethane contact angle of CF from 55.1° to 38.5°, which reduced the Lifshitz-van der Waals interaction energy, while urea modification further increased the zeta potential of CF from 12.8 mV to -0.7 mV, thereby reducing the electrostatic interaction energy. Experiments and DLVO theory both determined that a combination of nitric acid oxidation and urea modification significantly enhanced the ability of CF to immobilise microorganisms.

Analysis of the influence of surgical robot drilling parameters on the temperature of skull drilling based on Box-Behnken design.

It is easy to cause thermal damage to the bone tissue when the surgical robot performs skull drilling to remove bone flaps, due to the large diameter of the drill bit, the large heat-generating area, and the long drilling time. Therefore, in order to reduce the thermal damage during the robot-assisted skull drilling process, the relationship between the drilling parameters and the drilling temperature during the skull drilling was studied in this paper. Firstly, a dynamic numerical simulation model of the skull drilling process was established by ABAQUS, and a temperature simulation plan for skull drilling was designed based on the Box-Behnken method. Then according to the simulation results, a quadratic regression model of drill diameter, feed rate, drill speed, and drilling temperature was established by using the multiple regression method. By analyzing the regression model, the influence of drilling parameters on the drilling temperature was clarified. Finally, the bone drilling experiment was carried out, and the error percentage was lower than 10.5% through the experiment to verify the reliability of the conclusion, and a safety strategy was proposed to ensure the safety of the surgical drilling process based on this experiment.

Inhibition of aflatoxins on UDP-glucuronosyltransferases (UGTs).

Aflatoxins have been recognized as the most harmful mycotoxins leading to various toxic effects. The present study aims to determine the inhibition behavior of aflatoxins on the activity of the important phase II metabolizing enzymes, UDP-glucuronosyltransferases (UGTs), based on in vitro incubation system of recombinant human UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU). 100 µM AFB1 and AFG1 exhibited extensive inhibition towards UGT isoforms especially UGT1A7 and UGT1A8, with the inhibition ratios to be 71.38%, 72.95% and 72.79% for AFB1 to UGT1A7, AFB1 to UGT1A8 and AFG1 to UGT1A8, respectively. Molecular docking results showed that hydrogen bonds and hydrophobic contacts of the particular structure consisting of double furan ring with double bond contributed to the interaction of aflatoxins and UGTs. Kinetics analysis, including inhibition types and kinetics parameters (Ki), and in vitro-in vivo extrapolation (IVIVE) indicated that there might be a medium possibility of inhibition on UGTs by aflatoxins in vivo. In conclusion, the present study indicated that aflatoxins could possibly disturb endogenous metabolism by inhibiting the activity of UGTs so as to exhibit toxic effects.

Polyurethane Shape Memory Polymer/pH-Responsive Hydrogel Hybrid for Bi-Function Synergistic Actuations.

Stimuli-responsive actuating hydrogels response to the external stimulus with complex deformation behaviors based on the programmable anisotropic structure design are one of the most important smart soft materials, which have great potential applications in artificial muscles, smart values, and mini-robots. However, the anisotropic structure of one actuating hydrogel can only be programmed one time, which can only provide single actuating performance, and subsequently, has severely limited their further applications. Herein, we have explored a novel SMP/hydrogel hybrid actuator through combining polyurethane shape memory polymer (PU SMP) layer and pH-responsive polyacrylic-acid (PAA) hydrogel layer by a napkin with UV-adhesive. Owing to both the super-hydrophilicity and super-lipophilicity of the cellulose-fiber based napkin, the SMP and the hydrogel can be bonded firmly by the UV-adhesive in the napkin. More importantly, this bilayer hybrid 2D sheet can be programmed by designing a different temporary shape in heat water which can be fixed easily in cool water to achieve various fixed shapes. This hybrid with a fixed temporary shape can achieve complex actuating performance based on the bi-functional synergy of temperature-triggered SMP and pH-responsive hydrogel. The relatively high modulus PU SMP achieved high to 87.19% and 88.92% shape-fixing ratio, respectively, correspond to bending and folding shapes. The hybrid actuator can actuate with the 25.71 °/min actuating speed. Most importantly, one SMP/hydrogel bi-layer hybrid sheet was repeatedly programmed at least nine times in our research to fix various temporary 1D, 2D and 3D shapes, including bending, folding and spiraling shapes. As a result, only one SMP/hydrogel hybrid can provide various complex stimuli-responsive actuations, including the reversable bending-straightening, spiraling-unspiraling. A few of the intelligent devices have been designed to simulate the movement of the natural organisms, such as bio-mimetic "paw", "pangolin" and "octopus". This work has developed a new SMP/hydrogel hybrid with excellent multi-repeatable (≥9 times) programmability for high-level complex actuations, including the 1D to 2D bending and the 2D to 3D spiraling actuations, which also provides a new strategy to design other new soft intelligent materials and systems.

An Anisotropic Hydrogel by Programmable Ionic Crosslinking for Sequential Two-Stage Actuation under Single Stimulus.

As one of the most important anisotropic intelligent materials, bi-layer stimuli-responsive actuating hydrogels have proven their wide potential in soft robots, artificial muscles, biosensors, and drug delivery. However, they can commonly provide a simple one-actuating process under one external stimulus, which severely limits their further application. Herein, we have developed a new anisotropic hydrogel actuator by local ionic crosslinking on the poly(acrylic acid) (PAA) hydrogel layer of the bi-layer hydrogel for sequential two-stage bending under a single stimulus. Under pH = 13, ionic-crosslinked PAA networks undergo shrinking (-COO-/Fe3+ complexation) and swelling (water absorption) processes. As a combination of Fe3+ crosslinked PAA hydrogel (PAA@Fe3+) with non-swelling poly(3-(1-(4-vinylbenzyl)-1H-imidazol-3-ium-3-yl)propane-1-sulfonate) (PZ) hydrogel, the as-prepared PZ-PAA@Fe3+ bi-layer hydrogel exhibits distinct fast and large-amplitude bidirectional bending behavior. Such sequential two-stage actuation, including bending orientation, angle, and velocity, can be controlled by pH, temperature, hydrogel thickness, and Fe3+ concentration. Furthermore, hand-patterning Fe3+ to crosslink with PAA enables us to achieve various complex 2D and 3D shape transformations. Our work provides a new bi-layer hydrogel system that performs sequential two-stage bending without switching external stimuli, which will inspire the design of programmable and versatile hydrogel-based actuators.