Multistimuli-Responsive Shape-Memory Composites with a Water-Assisted Self-Healing Function Based on Sodium Carboxymethyl Cellulose/Poly(vinyl alcohol)/MXene.

Recent advancements in artificial intelligence have propelled the development of shape-memory polymers (SMPs) with sophisticated, environment-sensitive capabilities. Despite the progress, most of the existing SMPs are limited to responding to a single stimulus and show poor functionality, which has severely hindered their future applications. Herein, we report a high-performance multistimuli-responsive shape-memory and self-healing composite film fabricated by embedding MXene nanosheets into a conventional shape-memory sodium carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) matrix. The incorporation of photothermal MXene nanosheets not only enhances the composite films' mechanical strength but also provides efficient solar-thermal conversion and robust light-actuated shape-memory properties. The resultant composite films exhibit an exceptional shape-memory response to various stimuli including heat, light, and water. Meanwhile, the interfacial interactions can be modulated by adjusting the MXene content, thereby enabling precise manipulation of the shape-memory performance. Moreover, thanks to the intrinsic hydrophilicity of the components and the unique physically cross-linked network, the composite films also demonstrate an effective water-assisted self-healing capability with an impressive healing efficiency of 85.7%. This work offers insights into the development of multifunctional, multistimuli-responsive shape-memory composites, opening up new possibilities for future applications in smart technologies.

FAM237A, rather than peptide PEN and proCCK56-63, binds to and activates the orphan receptor GPR83.

G protein-coupled receptor 83 (GPR83) is primarily expressed in the brain and is implicated in the regulation of energy metabolism and some anxiety-related behaviours. Recently, the PCSK1N/proSAAS-derived peptide PEN, the procholecystokinin-derived peptide proCCK56-63, and family with sequence similarity 237 member A (FAM237A) were all reported as efficient agonists of GPR83. However, these results have not yet been reproduced by other laboratories and thus GPR83 is still officially an orphan receptor. The peptide PEN and proCCK56-63 share sequence similarity; however, they are completely different from FAM237A. To identify its actual ligand(s), in the present study we developed NanoLuc Binary Technology (NanoBiT)-based ligand-binding assay, fluorescent ligand-based visualization, and NanoBiT-based ß-arrestin recruitment assay for human GPR83. Using these assays, we demonstrated that mature human FAM237A could bind to GPR83 with nanomolar range affinity, and could activate this receptor and induce its internalization with nanomolar range efficiency in transfected human embryonic kidney 293T cells. However, we did not detect any interaction of PEN and proCCK56-63 with GPR83 using these assays. Thus, our results confirmed that FAM237A is an efficient agonist of GPR83, but did not support PEN and proCCK56-63 as ligands of this receptor. Clarification of their pairing paves the way for further functional studies of the brain-specific receptor GPR83 and the so far rarely studied neuropeptide FAM237A in the future.

Enhanced thermotolerance and ethanol tolerance in Saccharomyces cerevisiae mutated by high-energy pulse electron beam and protoplast fusion.

To increase thermotolerance and ethanol tolerance in Saccharomyces cerevisiae strain YZ1, the strategies of high-energy pulse electron beam (HEPE) and three rounds of protoplast fusion were explored. The YF31 strain had the characteristics of resistant to high-temperature, high-ethanol tolerance, rapid growth and high yield. The YF31 could grow on plate cultures up to 47 °C, containing 237.5 g L(-1) of ethanol. In particular, the mutant strain YF31 generated 94.2 ± 4.8 g L(-1) ethanol from 200 g glucose L(-1) at 42 °C, which was 2.48 times the production of the wild strain YZ1. Results demonstrated that the variant phenotypes from the strains screening by HEPE irradiation could be used as parent stock for yeast regeneration and the protoplast fusion technology is sufficiently powerful in combining suitable characteristics in a single strain for ethanol fermentation.

Down-regulation of CX43 expression by miR-1 inhibits the proliferation and invasion of glioma cells.

Background: Connexin (CX) 43 makes glioblastoma resistant to temozolomide, the first-line chemotherapy drug. However, targeting CX43 is very difficult because the mechanisms underlying CX43-mediated resistance remain unclear. CX43 is highly expressed in glioblastoma, which is closely associated with poor prognosis and chemotherapy resistance. The present study was to analyze the mechanism of microRNA (miR)-1 in regulating the proliferation and invasion of glioma cells. Methods: The effects of knockdown of miR-1 on the growth of glioma cell lines were observed by establishing blank, miR-1 inhibitor, and miR-1 mimic groups. Cell proliferation was detected using a Cell Counting Kit-8 (CCK-8) assay, cell apoptosis was detected by flow cytometry, and protein expression was detected by western blot. We used the Student's t-test to assess continuous data between the two groups and the Kruskal-Wallis test was adopted for multiple group comparisons. Results: Compared with the mimics normal control (NC) group, the apoptosis rate of the miR-1-3p mimics group was decreased, while that of the miR-1-3p inhibitor group was increased compared to the inhibitor NC group. In addition, the miR-1-3p mimics model of U251 cells exerted an inhibitory effect on the invasion ability of cells, whereas the miR-1-3p inhibitor model of U251 cells showed an invasion-promoting effect. The dual-luciferase assay showed that miR-1-3p had a targeted relationship with the CX43 gene. Conclusions: Down-regulation of CX43 expression by miR-1 inhibited the infiltration and growth of glioma cells and further promoted the apoptosis of glioma cells by regulating CX43 expression.

Nano-Fe3O4-modified biochar promotes the formation of iron plaque and cadmium immobilization in rice root.

Rice as a paddy field crops, iron-containing materials application could induce its iron plaque formation, thereby affecting cadmium (Cd) transportation in the rhizosphere and its uptake in root. In this study, a hydroponic experiment was conducted to investigate the effects of three exogenous iron materials, namely nano-Fe3O4-modified biochar (BC-Fe), chelated iron (EDTA-Fe), and ferrous sulfate (FeSO4), on the iron plaque formation on the surface of rice root, and to investigate the effects of formed iron plaque on the absorption, migration, and transportation of Cd and Fe in rice plant. The results showed that yellow-brown and brown iron plaque was formed on surface cells of the Fe-treated rice root, and some black particles were embedded in the iron plaque formed by BC-Fe. The proportion of crystallized iron plaque (31.8%-35.9%) formed by BC-Fe was much higher than that formed by EDTA-Fe and FeSO4. The Cd concentrations in the crystallized iron plaque formed by BC-Fe were 7.64-13.0 mg·kg-1, and increased with the increasing of Fe concentrations in the plaque. The Cd translocation factor from root to stem (TFr-s) and the Cd translocation factor from stem to leaf (TFs-l) with BC-Fe treatment decreased by 84.7% and 80.0%, respectively. The results demonstrated that application BC-Fe promoted the formation of iron plaque and enhanced the sequestration of Cd and Fe in roots, thus reduced the transportation and accumulation of Cd in aerial rice tissues.

Effect of three Napier grass varieties on phytoextraction of Cd- and Zn-contaminated cultivated soil under mowing and their safe utilization.

The use of Napier grass to remediate heavy metal-contaminated soil is a new phytoremediation technique. The objective of this study was to evaluate the ability of Napier grass (Pennisetum purpureum Schumach.) to remediate Cd- and Zn-contaminated cultivated soil under nonmowing and mowing and the possibility of safe utilization of the stem and leaf after detoxification by liquid extraction. Three Napier grass varieties, P. purpureum cv. Mott (PM), P. purpureum cv. Red (PR), and P. purpureum cv. Guiminyin (PG), were planted in a field with 3.74 mg kg-1 Cd and 321.26 mg kg-1 Zn for 180 days. The maximum amounts of Cd and Zn removed by PG were 197.5 and 5023.9 g ha-1, respectively, almost equaling those of hyperaccumulators. Compared with nonmowing, mowing did not decrease the Cd and Zn contents in various tissues but increased the biomasses of PM, PR, and PG by 86.6%, 18.9%, and 26.1%, respectively. Compared with nonmowing, the amounts of Cd removed by PM, PR, and PG under mowing increased by 110.5%, 40.0%, and 107.9%, respectively, and that of Zn increased by 63.0%, 53.1%, and 71.6%. The dominant Cd and Zn chemical fractions in Napier grass were the pectate- and protein-integrated fractions. After liquid extraction, although the nutrient element (Ca, K, Mg, and Mn) contents in the stem and leaf were reduced significantly, the Cd and Zn contents decreased below the limit of the Chinese Hygienic Standard for Feeds, and the crude protein content was largely retained. Such detoxified stems and leaves can be safely used as feeds or as raw materials for energy production.

Effects of nano-Fe3O4-modified biochar on iron plaque formation and Cd accumulation in rice (Oryza sativa L.).

Nano-Fe3O4-modified biochar (BC-Fe) was prepared by the coprecipitation of nano-Fe3O4 on a rice husk biochar surface. The effects of BC-Fe on cadmium (Cd) bioavailability in soil and on Cd accumulation and translocation in rice (Oryza sativa L. cv. 'H You 518') were investigated in a pot experiment with 7 application rates (0.05-1.6%, w/w). BC-Fe increased the biomass of the rice plants except for the roots and affected the concentration and accumulation of Cd and Fe in the plants. The Cd concentrations of brown rice were significantly decreased by 48.9%, 35.6%, and 46.5% by the 0.05%, 0.2%, and 0.4% BC-Fe treatments, respectively. Soil cation exchange capacity (CEC) increased by 9.4%-164.1% in response to the application of BC-Fe (0.05-1.6%), while the soil Cd availability decreased by 6.81%-25.0%. However, 0.8-1.6% BC-Fe treatments promoted Cd transport to leaves, which could increase the risk of Cd accumulation in brown rice. Furthermore, BC-Fe application promoted the formation of iron plaque and enhanced the root interception of Cd. The formation of iron plaque reduced the toxicity of Cd to rice roots, but this barrier effect was limited and had an interval threshold (DCB-Fe: 22.5-27.3 g·kg-1) under BC-Fe treatments.

Binding of brilliant red compound to lysozyme: insights into the enzyme toxicity of water-soluble aromatic chemicals.

The non-covalent interaction of brilliant red (BR) with lysozyme was investigated by the UV spectrometry, circular dichroism (CD) and isothermal titration calorimetry (ITC). The thermodynamic characterization of the interaction was performed and the assembly complexes were formed: lysozyme(BR)(17) at pH 2.03, lysozyme(BR)(15) at pH 3.25 and lysozyme(BR)(12) at pH 4.35, which corresponded to the physiological acidities. The ionic interaction induces a combination of multiple non-covalent bonds including hydrogen bond, hydrophobic interaction and van der Waals force. The two-step binding model of BR was found, in which one or two BR molecules entered the hydrophobic intracavity of lysozyme and the others bound to the hydrophilic outer surface of lysozyme. Moreover, BR binding resulted in change of the lysozyme conformation and inhibition of the lysozyme activity. The possible binding site and type of BR and the conformational transition of lysozyme were speculated and illustrated. This work provided a useful approach for study on enzyme toxicity of aromatic azo chemicals.

[Absorption spectra analysis in the degradation process of quinoline in aqueous solution by VUV lights].

The feasibility of monitoring the degradation progress on line by UV-Vis absorption spectra in the degradation process of quinoline in aqueous solution using the low-pressure quartz mercury lamp as vacuum ultraviolet source was evaluated by the monitoring and protracting of the UV-Vis absorption spectra at different time. The characteristic and mechanism of the change in the UV absorption spectra were analyzed by monitoring the concentration of the substrate, COD (chemical oxygen demand), TOC (total organic carbon) and pH value of the solution. It was showed that quinoline occurs in different forms under different pH conditions and consequently causes different UV-Vis absorption spectra due to the N atom in the pyridine ring. In the degradation progress, the UV-Vis absorption spectra were impacted by the degradation rate of the substrates, the production rate of the intermediates and the pH value of the solution. Proton acids were produced as intermediates and make quinoline occur in the form of its conjugated acid. When the increase in the absorption produced by the protonation was equal to the decrease induced by the degradation, the curve of the absorption at 313 nm, the characteristic absorption peak of quinoline, showed a flat in the duration of 1-3 min and then decayed continuously. In addition, the absorption at 254 nm reached a maximum at 5 min and then decayed continuously to nearly 0 at 30 min, when the absorption of the system only occurred in the region of wavelength shorter than 220 nm, indicating that the substrate was degraded completely. The research revealed that UV absorption spectra could be used to monitor the degradation process of quinoline in aqueous solution by VUV lights.

Potential protein toxicity of synthetic pigments: binding of poncean S to human serum albumin.

Using various methods, e.g., spectrophotometry, circular dichroism, and isothermal titration calorimetry, the interaction of poncean S (PS) with human serum albumin (HSA) was characterized at pH 1.81, 3.56, and 7.40 using the spectral correction technique, and Langmuir and Temkin isothermal models. The consistency among results concerning, e.g., binding number, binding energy, and type of binding, showed that ion pair electrostatic attraction fixed the position of PS in HSA and subsequently induced a combination of multiple noncovalent bonds such as H-bonds, hydrophobic interactions, and van der Waals forces. Ion pair attraction and H-bonds produced a stable PS-HSA complex and led to a marked change in the secondary structure of HSA in acidic media. The PS-HSA binding pattern and the process of change in HSA conformation were also investigated. The potentially toxic effect of PS on the transport function of HSA in a normal physiological environment was analyzed. This work provides a useful experimental strategy for studying the interaction of organic substances with biomacromolecules, helping us to understand the activity or mechanism of toxicity of an organic compound.

Nanotoxicity of TiO(2) nanoparticles to erythrocyte in vitro.

Titanium dioxide (TiO(2)) has been considered as non-toxic mineral particles widely used in the fields like cosmetics, food and drug. When the scale come to nanometer, TiO(2) nanoparticles (nano-TiO(2)) exhibits multiple specific characteristics coupled with unknown risks on health. The purpose of this study was to systematically research the influence of nano-TiO(2) on erythrocyte. The results indicated that the erythrocytes treated with nano-TiO(2) underwent abnormal sedimentation, hemagglutination and dose dependent hemolysis, totally differing from those treated with micro-TiO(2). The ghost cells were firstly investigated by using ultra-thin cell section in the case under nano-TiO(2). The mechanism of such adverse effects is (1) the attachment around erythrocyte change the surface native properties and ultimately lead to hemoagglutination; (2) the content leak to the outside of erythrocyte through the breakage induced by both the nano-TiO(2) trans-membrane and the oxidative stress under nano-TiO(2). Our findings imply that nano-TiO(2) may have potential toxicity to human being health.

Catalytic metalloporphyrin protects against paraquat neurotoxicity in vivo.

OBJECTIVE: To examine the neuroprotective effects of a novel manganese porphyrin, manganese (III) meso-tetrakis (N,N'-diethylimidazolium-2-yl) porphyrin (MnTDM), in the mouse model of Parkinson's disease (PD) induced by paraquat (PQ). METHODS: Male C57BL/6 mice were subcutaneously injected with either saline or PQ at 2-day intervals for a total of 10 doses, MnTDM was subcutaneously injected with the PQ 2 h before treatment. Performance on the pole and swim test were measured 7 days after the last injection and animals were sacrificed one day later. Levels of dopamine (DA) and its metabolites in the striatum were measured by high-performance liquid chromatography with an electrochemical detector (HPLC-ECD). Thiobarbituric acid (TBA) method was used to assay the lipid peroxidation product, malondialdehyde (MDA), and the number of tyrosine hydroxylase (TH) positive neurons was estimated using immunohistochemistry. RESULTS: Pretreatment with MnTDM significantly attenuated PQ-impaired behavioral performance, depleted dopamine content in striata, increased MDA, and dopaminergic neuron loss in the substantia nigra. CONCLUSIONS: Oxidative stress plays an important role in PQ-induced neurotoxicity which can be potentially prevented by manganese porphyrin. These findings also propose a possible therapeutical strategy for neurodegenerative disorders associated with oxidative stress such as PD.

[Studies on the spectral characteristics of efficient HIV-1 fusion inhibitor C22].

Acquired immune deficiency syndrome (AIDS) is increasing its negative influences on human society and economy. In the present paper, HIV-1 cell fusion peptide inhibitor C22 was expressed and purified based on the C-terminal sequence of HIV-1 membrane fusion glycoprotein gp41. The gene coding for C22 was totally synthesized using gp41 gene as a template and amplified by PCR The cloned C22 gene was confirmed by restriction endonuclease and sequence analysis and then cloned into plasmid pTMHa30-51. The prepared plasmid was transformed into E. coli BL21 (DE3) and the expressing products were analyzed on SDS-PAGE and tested with mass spectrum. The results indicated that C22 showed high HIV-1 fusion inhibiting capacity, meanwhile, with good thermal stability and water-solubility, and showed no cell toxicity in tested concentrations. The spectral characteristics were tested with circular dichroism (CD). When treated at different temperature in solution condition, the content of a helix of C22 increased at 37 degrees C while decreased sharply at 80 degrees C. The peak value changed significantly with different pH values. The content of a helix of C22 decreased as pH varied toward acid and alkali and the random coiling increased, which led to a relaxed structure. This result indicated that the C22 structure is stable with pH 6. This research may provide a theoretic foundation for the new type HIV-1 peptide inhibitor designing and spectral characteristics study.

Early predictors of hyperlipidemic acute pancreatitis.

The present study aimed to investigate early risk factors for hyperlipidemic acute pancreatitis (HLAP) in order to open up novel routes for its prevention and treatment. Demographics, laboratory data obtained within 48 h, enhanced computed tomography (CT) imaging data and the modified CT severity index (MCTSI) for 111 patients with HLAP who were assessed at Ordos Central Hospital (Ordos, China) between January 2015 and October 2017 were retrospectively analyzed. Of these, 17 patients progressed to infectious pancreatic necrosis (IPN) and 14 patients progressed to organ failure (OF), the occurrence of which were the study outcomes. The patients were divided into pairs groups: IPN and non-IPN, as well as OF and non-OF, and differences between the groups were determined regarding various clinicopathological parameters. Furthermore, univariate and multivariate regression analyses were performed to identify parameters associated with the risk of progression to IPN or OP. On univariate analysis, the following parameters were deemed as being significantly associated with the risk of IPN: Serum calcium ions, C-reactive protein (CRP), extent of necrosis, procalcitonin (PTC) and the MCTSI. Furthermore, calcium ions, red cell distribution width (RDW), extent of necrosis and the MCTSI were significantly associated with the risk of OF on univariate analysis. Multivariate logistic regression analysis for these parameters then indicated that CRP (P=0.014), RDW (P=0.025) and the extent of necrosis (P=0.022) were significant and independent predictors of progression; thus, these are early risk factors for patients with HLAP. Receiver operating characteristic curves were generated to evaluate the predictive value of these factors, and the area under the curve for the three parameters was 0.863 [95% confidence interval (CI), 0.646-0.886], 0.727 (95% CI, 0.651-0.803) and 0.833 (95% CI, 0.739-0.936), respectively. Therefore, CRP, RDW and the extent of necrosis are early predictive indexes for the risk of progression in HLAP.

[Spectroscopy study of the immobilized cellulase of magnetic nanoparticles Fe3O4].

Fe3O4 magnetic nanoparticles were synthesized by chemical coprecipitation method using ammonia as the precipitator in the present paper. And then cellulase was immobilized on Fe3O4 magnetic nanoparticles via carbodiimide activation, which was testified by FTIR and lots of repeating catalysis experiments. The morphology of nanoparticles immobilized by cellulase was characterized by TEM, and the activity of cellulase was measured by DNS spectrophotometry. The optimum temperature (60 degrees C) and pH value (3.94-5.50) for the catalysis ablility of immobilized cellulose were studied. The result showed that compared with the native enzyme the cellulase immobilized on Fe3O4 magnetic nanoparticles has the advantages of thermal stability, storage stability, and more extensive optimum pH value.

[Studies on the electron transfer between etoposide (VP-16) and DNA].

In the present study, the electron transfer between Etoposide (VP-16) and GMP or DNA was investigated using pulse radiolysis and circular dichroism technology. The electron transfer between VP-16 and GMP was found, and the reaction rate constant was determined as 3.16 x 10(7) L x mol(-1) x s(-1) by pulse radiolysis. The authors found the interaction of VP-16 and DNA using the technology of circular dichroism. This study has provided theoretical reference for further study on the anti-tumor mechanism of VP-16.

[Spectral analysis of transient species of quinoline degradation].

Quinoline's degradation was studied by pulse radiolysis. It was found that hydrated electron, hydrogen radical, hydroxyl radical and SO4*- can react with quinoline. The absorption spectra of the transient species of quinoline were obtained, and related constants were determined, but it was found that the species of Br2*- and N3*- can't react with quinoline. The results give us some advices for studing the degradation of quinoline.

[Studies on the effect of extracts of several Chinese herbal medicines and other medicines on alcohol dehydrogenase activity].

OBJECTIVE: To study the effects of water and alcohol extracts of several Chinese herbal medicines and other medicines on alcohol dehydrogenase activity in order to provide enzymology basis on new medicine. METHODS: Water or alcohol extracts of Chinese herbal medicine and other medicine were tested on the effects of alcohol dehydrogenase activity by Valle and Hoch method. RESULTS: Among them, 8 were found to have the effect of activation on alcohol dehydrogenase. They were water extracts of Amomum kravanh and Pueraria flowers, the alcohol extracts of Pueraria flowers, compound hepatcare Chinese medicine and compound Pueraria medicine, L-cysteine, notoginseng saponin. Others had inhibiting action. CONCLUSION: To decrease alcohol concentration in the body through activating the activity of ADH may be one of the mechanisms for some traditional Chinese herbal medicine in neutralizing the effect of alcohol drink.

[Mechanism and kinetics studies on the degradation of acid orange 7].

The reactions of *OH and e(aq)-, with AO7 in aqueous solutions were studied by nano-second pulse radiolysis techniques. The transient absorption spectra were attributed and the second order reaction rate constants were determined by following the buildup kinetics of the transient absorptions. In combination with the analysis of the UV-Vis absorption changes of AO7 after gamma-radiolysis, the underlying reaction mechanisms were elucidated.