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Piezo-catalysis has been emerged as a green and promising wastewater treatment technology for efficient removal of persistent organic pollutants (POPs), such as 4-nitrophenol (4-NP). However, it remains challenging to achieve advanced materials with combined advantages of high piezo-catalytic efficiency, good hydrophilicity, and environmental friendliness. In this work, highly crystalline porous polylactide (PLA) membranes possessing such exceptional advantages have been successfully prepared from biodegradable poly(L-lactide)/poly(D-lactide)/polyethylene glycol/polyoxyethylene-polyoxypropylene block copolymer (PLLA/PDLA/PEG/PEO-PPO-PEO) blends by melt processing and subsequent water etching. During the melt-processing, the two PLA enantiomers co-crystallize into stereocomplex (SC) crystals and simultaneously the PEG used as a porogen is expelled from the crystalline regions. The results show that the prepared PLA membranes have not only abundant micro-porous structures but also good hydrophilicity due to the preferential localization of PEO-PPO-PEO copolymer on the pore walls, thus giving rise to an extremely high water flux of 2400 L/m2h. More interestingly, the PLA membranes exhibit remarkable piezoelectric activity and the piezo-catalytic degradation efficiency of 4-NP can reach as high as 96 % under the triggering of water flow involved in vacuum filtration. In addition, the membranes show excellent reusability and the high catalytic efficiency can be well-maintained after five repeated uses. These findings suggest broad application prospects of our porous SC-PLA membranes in organic wastewater treatment. [Display omitted] • Highly crystalline SC-PLA membranes with hierarchically porous structures were prepared. • PEO-PPO-PEO copolymer improves the hydrophilicity and permeability of the membranes. • The membranes possess ultrahigh piezo-catalytic activity for the degradation of POPs. • The piezo-catalytic membranes have good reusability in organic wastewater treatment. [ABSTRACT FROM AUTHOR]

Stereocomplex (SC) crystallization can prominently improve the physico-chemical properties of poly(l -lactide)/poly(d -lactide) (PLLA/PDLA) blends, yielding a novel polylactide (PLA) material. However, the predominant formation of SC crystals in the melt-processing of high-molar-mass (high-MW, >100 kg/mol) enantiomeric PLA blends remains a huge challenge due to the competition between SC crystallization and homocrystallization. Herein, double-grafted copolymer having both PLLA and PDLA side chain has been designed and synthesized as an efficient crystallization promoter for the harvest of SC crystals in the high-MW PLLA/PDLA blends. The results show that, with the addition of such a copolymer, the blends can preferentially crystallize into SC crystals in both isothermal and non-isothermal conditions. Promisingly, the SC crystals can be exclusively formed by adding only small amounts (e.g., 0.5 wt%) of the copolymer, without the formation of any homocrystals. This interesting observation can be interpreted by the crucial role of the unique copolymer in suppressing the phase separation of the opposite PLA enantiomers upon melting as an efficient compatibilizer and then encouraging the generation of alternatingly arranged PLLA/PDLA chain clusters favored for SC nucleation and crystal growth. These findings provide new inspiration for the development of high-performance PLA with desirable SC crystallizability. [Display omitted] [ABSTRACT FROM AUTHOR]

Over the past two decades, biomass-derived and biodegradable polylactide (PLA) has sparked tremendous attention as a sustainable alternative to traditional petroleum-derived polymers for diverse applications. Unfortunately, the current applications of PLA have been mainly limited to biomedical and commodity fields, mostly because the poor heat resistance (resulting from low melting temperature) and hydrolysis stability make it hard to use as an engineering plastic. Stereocomplexation between enantiomeric poly( l-lactide) (PLLA) and poly( d-lactide) (PDLA) opens a new avenue toward PLA-based engineering plastics with improved properties. The formation, crystal structure, properties, and potential applications of stereocomplex-type PLA (SC-PLA) are summarized by some research groups. However, since it is challenging to achieve full stereocomplexation from high-molecular-weight PLLA/PDLA blends and to avoid serious thermal degradation of the PLAs after complete melting, the advances and progress in the processing of SC-PLA into useful products are quite rare in open publication. In this review, some important strategies for enhancing stereocomplex crystallization in practical processing operations are presented and recently developed processing technologies for SC-PLA are highlighted, such as low-temperature sintering. Furthermore, major challenges and future developments are briefly discussed. This review is expected to potentially open up new research activities in the processing of SC-PLA. [ABSTRACT FROM AUTHOR]

Bioassay-guided phytochemical investigation of the EtOAc fraction (ST-EtOAc) from the roots of Sophora tonkinensis resulted in the isolation of a new compound 6a R ,11a R -1-hydroxy-4-isoprenyl-maackiain ( 1 ), along with 12 known compounds ( 2 – 13 ). The structure of the new compound was established by 1D and 2D NMR, MS data and circular dichroism analysis. Polyprenylated flavonoids 6 – 9 and 11 – 13 increased GLUT-4 translocation by the range of 1.35–2.75 folds. Sophoranone (8 ) exerted the strongest activity with 2.75 folds GLUT-4 translocation enhancement at the concentration of 10 μM. This is the first report of the GLUT-4 translocation activity of the plant Sophora tonkinensis . [ABSTRACT FROM AUTHOR]

As a new generation of biodegradable hard tissue repair implants, the excessive corrosion rate in a liquid environment and the potential cytotoxicity of magnesium and its alloys have limited their further clinical applications to some extent. Because of this, in this study, a network-like porous structural surface with relatively uniform pore size was designed and prepared on the surface of AZ31 magnesium alloy by acid etching treatment, and the HAp prepared on this surface exhibited the advantage of high interfacial bonding strength, and the (H+)HAp /CS composite coating was prepared by using biocompatible CS as the sealing layer of the HAp coating pores, and the acid etching was investigated by electrochemical tests. The corrosion resistance of HAp prepared under acid-etching conditions and HAp prepared on AZ31 surface without acid-pickling treatment were investigated by electrochemical tests, while the composite coatings were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and EDS, and further tests such as electrochemical experiments, hydrogen precipitation experiments and cytocompatibility assessment concluded that the composite coating has good corrosion resistance, can effectively reduce the degradation rate of magnesium alloy, low magnesium ion precipitation concentration in the cell culture process has less effect on cell growth, and the coating can promote the attachment and proliferation of BMSCs osteoblasts, showing excellent cytocompatibility. Therefore, this study provides a new idea for the design of AZ31 surface morphology and the improvement of corrosion resistance and biocompatibility of AZ31 magnesium alloy, which is beneficial to promote the further development of AZ31 magnesium alloy as a bone repair material. The figure shows that the (H+)HAp/CS coating was prepared on the porous AZ31 surface obtained under acid etching treatment, which has a blocky structure with high interfacial bonding strength to the substrate material. In tests, the coating showed good corrosion resistance and excellent biocompatibility and can be used as a protective coating for AZ31 for application to bone implants. Furthermore, due to the high interfacial bonding strength of the coating prepared on the porous surface of AZ31, it provides a good basis for the application of AZ31 magnesium alloy as a bone repair material. [Display omitted] • Formation of uniform nanoscale porous structures on the surface of AZ31 by acid-washing treatment • The rough surface of the porous structure improves the interfacial bonding strength of the HAp coating, and the sealing of the viscous substance CS on the HAp surface further enhances the interfacial bonding strength of the coating • The (H+)HAp/CS composite coating shows good corrosion resistance with a corrosion protection efficiency PE of 99.80% and an annual corrosion rate CR of 0.0101 mm/year • The material has shown good promotion of osteoblast growth and proliferation in cytocompatibility tests [ABSTRACT FROM AUTHOR]

Sustainable stereocomplex-type polylactide (SC-PLA) has been recognized as a potential substitute for some traditional engineering plastics, however its widespread application still faces several hurdles primarily related to poor melt processability (i.e., the unfavorable melt memory effect in SC crystallization as well as the low melt strength) and insufficient fracture toughness. To overcome these hurdles, an equimolar poly(l -lactide)/poly(d -lactide) (PLLA/PDLA) blend toughened with poly(ethylene -co- vinyl acetate) (EVA) has been chosen as a model system and a facile strategy has been devised by incorporating trace amounts (i.e., 0.5 wt%) of epoxy-functionalized oligo(styrene-acrylic) (ESA) into the PLLA/PDLA/elastomer blends through direct melt-blending at 200 °C. Such a one-pot blending not only facilitates the stereocomplexation between PLLA and PDLA chains but also permits the highly efficient reaction between terminal hydroxyl groups of some enantiomeric PLAs and epoxy groups of ESA before their stereocomplexation. This results in the in situ generation of large amounts of long-chain-branched PLA- graft -ESA copolymer in the SC-PLA matrix. Very impressively, the generation of this PLA- graft -ESA copolymer gives rise to a substantial improvement in the melt memory effect of the SC-PLA matrix. This copolymer behaves as a compatibilizer to stabilize regular PLLA/PDLA chain clusters in blend melts and hence to stimulate the exclusive formation of SC crystallites in melt-processed blend products. In addition, long PLA branches endow the matrix with a considerably enhanced melt viscosity owing to the increased interchain entanglement density. Consequently, highly stereocomplexed SC-PLA/EVA products with exceptional impact toughness and heat resistance as well as robust mechanical strength have been prepared by injection molding. More notably, this strategy can be generalized to various SC-PLA-based blends, irrespective of whether the elastomers have reactive groups. Overall, these exciting findings illustrate a promising avenue toward the design and applications of high-performance SC-PLA-based materials with excellent melt-processability via the generation of unique graft copolymers having long PLLA and PDLA branches. [Display omitted] • SC-PLA/elastomer blends with markedly enhanced melt processability are designed. • Long-chain-branched copolymers are in-situ generated during melt-blending with ESA. • The chain branching induces drastically enhanced melt memory effect and melt strength. • The blends have been injection-molded into super-tough and heat-resistant products. • Our strategy can be generalized to various SC-PLA-based blends. [ABSTRACT FROM AUTHOR]

Inspired by the tactile sensory mechanism of human skin, ionic hydrogels‐derived ionic flexible sensors have attracted much attention since they can produce output signals that match the recognition mode of nerves, showing a potential application in the human‐machine interaction. Unfortunately, the practical sensing properties of ionic hydrogels are restricted by the drawbacks of hydroelastic instability and non‐selective response ability, such as poor mechanical strength, irretentive solvent retaining capacity, and low‐temperature intolerance. Herein, in this study, a novel physical‐crosslink enhanced ionic hydrogel‐PVA/PEG/TA‐MXene‐Na+/Li+ (PPM‐NL) nanocomposite is prepared and shows well comprehensive properties of mechanical strength (400% elongation at break, 0.93 MPa), electrical conductivity (8.1 S m−1), tear resistance, self‐healing and anti‐freezing/drying features (93% water retention after sixty days and frost resistance −27 °C). The PPM‐NL hydrogel‐derived flexible sensor displays selective response behavior to tensile and compressive deformation with high sensitivity (G = 1.12) and rapid response time (only 60 ms). Further, this ionic flexible device is applied to monitor the joint motions of humanoid hands and integrated into manipulators to recognize the thickness and softness of objects, showing superior environmental stability. It can be believed that this ionic flexible sensor will provide inspiration for developing next‐generation biomimetic tactile perception of robots. [ABSTRACT FROM AUTHOR]

Abstract Polylactide (PLA), a promising biodegradable and renewable polymer, finds many applications, particularly, used as biodegradable fiber in textile industry. The key is to improve its heat resistance. In this work, small amount of poly (D-lactide) (PDLA) was added firstly into poly (L-lactide) (PLLA) matrix to form stereocomplex polylactide (SC-PLA), which has much better heat resistance than that of PLLA matrix. Then two melting temperatures were adopted for fiber spinning, the one (210 °C) is far below the melting temperature of SC-PLA (i.e., 220–230 °C), and the other (225 °C) is close to the melting temperature of SC-PLA. The boiling water shrinkage and tensile strength of PLLA/PDLA fibers were investigated as function of PDLA content. It was found, the boiling water shrinkage could be largely reduced to as low as 5.6% and a satisfactory tensile strength (628 MPa) is achieved for fibers spun at 225 °C, compared with fibers spun at 210 °C (7.5% and 500 MPa, respectively), as the PDLA content is 3 wt%. SEM observation suggests a formation of nanofibrillar like SC-PLA structure as spun at 225 °C, while only spherical SC-PLA particles as spun at 210 °C. DSC result indicates that adding PDLA could largely enhance the crystallization rate of PLLA, but almost a constant crystallinity and SC-PLA content were observed for both spun fibers, disregarding the spinning temperatures. Herman's orientation parameters of spun fiber were obtained from 2D-WAXD, which suggests that fiber spun at 225 °C has higher orientation than that of fiber spun at 210 °C. Thus it can be concluded that the formation of nanofibrillar like SC-PLA and enhanced orientation degree contribute mainly to the improved heat resistance and tensile strength. This work presents a feasible and effective way to fabricate all-PLA-based fibers with the outstanding heat resistance by adding a small amount of PDLA and using a suitable spinning temperature. Graphical abstract Image 1 Highlights • The influence of spinning temperature on the orientation and properties of PLLA/PDLA fibers was depicted in detail. • A critical PDLA content of increasing PLLA/PDLA fibers' heat resistant and mechanical property was revealed.. • All-PLA-based fiber with outstanding heat resistance was manufactured by melt spinning process. [ABSTRACT FROM AUTHOR]

Abstract As the most promising bio-derived and biodegradable polymers with tremendous application potential, the practical application of poly(l -lactide) (PLLA) has been severely restricted by its inherent brittleness. Unfortunately, blending with various rubbers can substantially enhance the toughness of PLLA, but usually causes a significant deterioration in mechanical strength and modulus. In this work, taking novel PLLA/core-shell rubber (CSR) blends as an example, we describe a facile and robust strategy to obtain good stiffness-toughness balance by promoting the networking of CSR particles within PLLA matrix with the aid of stereocomplex (SC) crystallites. To do this, small amounts (5–20 wt%) of poly(d -lactide) (PDLA) were incorporated into the blends through simple melt-blending. The results demonstrate that the CSR particles can be uniformly dispersed in PLLA matrix due to the good interfacial compatibility, but the stereocomplex (SC) crystallites formed between the incorporated PDLA and PLLA matrix chains induces the organization of the CSR particles into a network-like structure in the matrix. Compared with the well-dispersed structure, the network-like structure can endow the PLLA/CSR blends with dramatically enhanced impact toughness, without compromising their mechanical strength and modulus, indicating a marvelous balance between the stiffness and toughness. Furthermore, the elongation at break of the blends is also enhanced greatly. These interesting findings suggest that the formation of SC crystallites could provide a promising avenue for fabricating CSR particles toughened PLLA blends with balanced stiffness-toughness. Graphical abstract Image 1 Highlights • A promising strategy to induce the networking of CSR particles in PLLA/CSR blends has been reported. • The CSR particles can be organized into a network-like structure in PLLA matrix under the drive of SC crystallites. • The SC crystallites is formed during melt mixing of the blends with small amounts of PDLA. • The formation of the network structure can significantly enhance the toughening efficiency. • The obtained PLLA/CSR/PDLA blends exhibit a balanced stiffness and toughness. [ABSTRACT FROM AUTHOR]

Extracts and components of Taxodium ascendens Brongn, an excellent afforestation tree, have exhibited several activities, including antibacterial activity and inhibitory activity on carbonic anhydrase II. However, the anti-hepatocellular carcinoma (anti-HCC) activity of extracts from the leaves of T. ascendens (TALE) remains unclear. In the present study, six diterpenoid compounds were isolated from a TALE extract. Here, the pro-apoptotic activities and the molecular mechanisms of TALE and the compounds 1 – 6 on HepG2 and Hep3B HCC cells were evaluated. Results show that the TALE and compounds 1 – 6 were able to induce apoptosis in the HepG2 and Hep3B HCC cells, particularly ferruginol ( 3 ). Mechanistically, the application of TALE and ferruginol ( 3 ) resulted in a significant decrease in mitochondria membrane potential, which was coupled with an increase in the Bax/Bcl-2 ratio and caspase-3/-9 activity. In vivo experiments showed that oral administration of TALE inhibited the proliferation of transplanted H22 cells in Kunming mice. However, TALE toxicity in KM mice was undetectable. The study provides strong evidence for the anti-HCC capacity of TALE. [ABSTRACT FROM AUTHOR]

Despite of its enormous application potential as a prominent engineering bioplastic, the processing of the stereocomplex-type polylactide (SC-PLA) formed from poly(l -lactide)/poly(d -lactide) (PLLA/PDLA) blends into useful products remains challenging. Recently, low-temperature sintering has emerged as a feasible and promising processing technology towards transparent highly-crystalline SC-PLA products. During the sintering of SC-PLA nascent powder, the interfaces between adjacent particles could be bound together through SC crystallization of interdiffused PLLA and PDLA chains across the interfaces. However, the massive generation of the interface-localized SC crystallites is significantly impaired by the insufficient chain interdiffusion resulting from the rapid SC crystallization. In this work, miscible poly(methyl methacrylate) (PMMA) is adopted to substantially promote the chain interdiffusion by fundamentally diminishing the SC crystallization rate. Intriguingly, we find that the crystallization of PLLA/PDLA chains is greatly decelerated with the incorporation of PMMA and thus more enantiomeric PLA chains could interdiffuse through the interfaces before their crystallization. Moreover, the PMMA is also favorable for the particle wetting of the densified nascent powders, which makes it easier for the enantiomeric chains to interdiffuse across the interfaces. The promoted chain interdiffusion leads to an evident increase in the number of the newly-generated SC crystallites and resulting interfacial weld strength. Consequently, the sintered SC-PLA products possessing superior thermomechanical properties and markedly enhanced hydrolytic resistance have been fabricated by incorporating 9 wt% PMMA, without compromising transparency. These findings could bode well for the industrial fabrication and applications of SC-PLA products. Image 1 • PMMA has been used to improve the low-temperature sintering of SC-PLA nascent powder. • The PMMA can promotes the interdiffusion of PLLA/PDLA chains across the particle interfaces. • Both the decelerated crystallization and enhanced particle wetting contribute to the promotion of the chain interdiffusion. • Sufficient amounts of interface-localized SC crystallites are generated to achieve mechanically robust interfaces. • The obtained SC-PLA products have superior thermomechanical properties, transparency, and hydrolytic stability. [ABSTRACT FROM AUTHOR]

The present study investigated the anti-diabetic activity and potential mechanism of stigmasterol (SMR), which is a kind of phytosterols derived from the edible soybean oil in vitro and in vivo. SMR displayed a mild GLUT4 translocation activity by 1.44-fold in L6 cells. L6 cells were treated with different concentration of SMR, showing significant effects on the enhancing glucose uptake. SMR administrated orally to the KK-Ay mice significantly alleviated their insulin resistance and oral glucose tolerance with reducing fasting blood-glucose levels and blood lipid indexes such as triglyceride and cholesterol. Moreover, the GLUT4 expression in L6 cells, skeletal muscle and white adipose tissue had been also enhanced. In this paper we conclude that, stigmasterol seems to have potential beneficial effects on the treatment of type 2 diabetes mellitus with the probable mechanism of targeting GLUT4 glucose transporter included increasing GLUT4 translocation and expression. [ABSTRACT FROM AUTHOR]