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Anionic hybrid copolymerization (AHcP) of cyclic and vinyl monomers provides a powerful strategy to synthesize biodegradable heteropolymers. However, transesterification between comonomeric units often happens making the mechanism complex. Here, AHcP of N,N‐dimethylacrylamide (DMA) with ε‐caprolactone (CL) is investigated at 25 °C, where DMA does not have ester group so that no transesterification between DMA and CL units happens. Nuclear magnetic resonance (NMR) and matrix‐assisted laser desorption/ionization time of flight mass spectrometry measurements reveal that DMA and CL units are randomly distributed in the resulted polymer. Differential scanning calorimetry measurements show that the copolymer has only one glass transition temperature (Tg). Thermogravimetric analysis demonstrates the copolymer has a single‐stage decomposition from 255 to 425 °C, which is between those of the corresponding homopolymers. Thes facts further indicate that the copolymer is random. This study clearly demonstrates that AHcP takes place regardless of transesterification though it may have some effects. [ABSTRACT FROM AUTHOR]

Beta-cypermethrin (β-CYP) consists of four chiral isomers, acting as an environmental estrogen and causing reproductive toxicity, neurotoxicity, and dysfunctions in multiple organ systems. This study investigated the toxic effects of β-CYP, its isomers, metabolite 3-phenoxybenzoic acid (3-PBA), and 17β-estradiol (E2) on HTR-8/SVneo cells. We focused on the toxic mechanisms of β-CYP and its specific isomers. Our results showed that β-CYP and its isomers inhibit HTR-8/SVneo cell proliferation similarly to E2, with 100 μM 1S-trans-αR displaying significant toxicity after 48 h. Notably, 1S-trans-αR, 1R-trans-αS, and β-CYP were more potent in inducing apoptosis and cell cycle arrest than 1R-cis-αS and 1S-cis-αR at 48 h. AO/EB staining and flow cytometry indicated dose-dependent apoptosis in HTR-8/SVneo cells, particularly at 100 μM 1R-trans-αS. Scratch assays revealed that β-CYP and its isomers variably reduced cell migration. Receptor inhibition assays demonstrated that post-ICI 182780 treatment, which inhibits estrogen receptor α (ERα) or estrogen receptor β (ERβ), β-CYP, its isomers, and E2 reduced HTR-8/SVneo cell viability, whereas milrinone, a phosphodiesterase 3 A (PDE3A) inhibitor, increased viability. Molecular docking studies indicated a higher affinity of β-CYP, its isomers, and E2 for PDE3A than for ERα or ERβ. Consequently, β-CYP, its isomers, and E2 consistently led to decreased cell viability. Transcriptomics and RT-qPCR analyses showed differential expression in treated cells: up-regulation of Il24 and Ptgs2 , and down-regulation of Myo7a and Pdgfrb , suggesting the PI3K-AKT signaling pathway as a potential route for toxicity. This study aims to provide a comprehensive evaluation of the cytotoxicity of chiral pesticides and their mechanisms. [Display omitted] • 1S-trans-αR, 1R-trans-αS cause higher apoptosis in HTR-8/SVneo cells. • The isoforms of β-CYP show varied effects on cell migration and cycle. • β-CYP binds to PDE3A more than ER receptors, affecting cell viability. • 1R-trans-αS and 1S-trans-αR more potent than β-CYP in cellular impact. [ABSTRACT FROM AUTHOR]

This paper is concerned with the stabilisation problem of an Euler–Bernoulli beam with uncertain parameters and disturbances. To correctly represent the beam's behaviour, the partial differential equations model is utilised for the control design of the beam without missing any high-order mode information. Then the linear matrix inequalities (LMIs) method is applied to the robust adaptive neural network control design to cope with systematic uncertainties and stabilise the beam system with disturbance compensation. Through resolving LMIs, feasible sets of designed control parameters can be effectively obtained without model linearisation. Finally, numerical simulations are done to validate the effectiveness of the proposed control. [ABSTRACT FROM AUTHOR]

In this study, we evaluate the coordination tracking control problem of a flexible master–slave teleoperation system. The system under consideration is based on a dynamic model described by a set of partial differential equations. Existing research on bilateral controllers is based on teleoperation systems composed of rigid master robots and rigid or flexible slave robots. In this work, we consider teleoperation systems with flexible master and slave robots. We dynamically model flexible master–slave manipulators using partial differential equations. Based on the dynamic model, a bilateral coordination controller is developed to realize the coordination angle tracking and vibration suppression of flexible master–slave manipulators. The teleoperation system is proven to be asymptotically stable under the control scheme. Numerical simulation results illustrate that the proposed controller is effective. [ABSTRACT FROM AUTHOR]

In this study, we considered the coordination and vibration control for two sets of flexible satellite systems with input constraints and actuator failures. The parameters of both systems were kept uniform, and one was called the master flexible satellite, and the other one was called slave flexible satellite. The two sets of the flexible satellite systems were modelled as partial differential equations. Coordination control laws were designed to turn the master flexible satellite system to the desired angle and then turn the slave system to the angle of the master satellite system. Furthermore, the hyperbolic tangent function was adopted to realize the control input constraint. The adaptive control laws were designed to ensure that the systems work normally even when the actuator fails. Lyapunov's direct method was adopted and stability analysis was given. Finally, numerical simulations were conducted to validate the results. [ABSTRACT FROM AUTHOR]

Background: At present, the pathogenesis of depression is not fully understood, and nearly half of depression patients experience no obvious effects during treatment. This study aimed to establish a depression mouse model to explore the possible role of ferroptosis in the pathogenesis of depression, and observe the effects of Xiaoyaosan on PEBP1-GPX4-mediated ferroptosis in the hippocampus. Methods: Forty-eight male C57BL/6 mice were randomly divided into a control group, CUMS group, Xiaoyaosan group and fluoxetine group, and the model was established by chronic unpredictable mild stress (CUMS) for a successive 6 weeks. The medication procedure was performed from the 4th to the 6th week of modeling. The behavioral evaluations were measured to evaluate depressive-like behaviors. The expressions of GPX4, FTH1, ACSL4 and COX2 were detected as ferroptosis-related indicators. Then, the total iron and ferrous content in the hippocampus were measured. The levels of PEBP1 and ERK1/2 were observed, and the expressions of GFAP and IBA1 were also detected to measure the functions of astrocytes and microglia in the hippocampus. Results: Eight herbs of Xiaoyaosan had 133 active ingredients which could regulate the 43 ferroptosis-related genes in depression. After 6 weeks of modeling, the data showed that mice in the CUMS group had obvious depressive-like behaviors, and medication with Xiaoyaosan or fluoxetine could significantly improve the behavioral changes. The expressions of GPX4, FTH1, ACSL4, COX2, PEBP1, ERK1/2, GFAP and IBA1 changed in the CUMS group mice, while the total iron and ferrous content also changed. Xiaoyaosan and fluoxetine had obvious curative effects that could significantly alleviate the above changes in the hippocampus. Conclusion: Our results revealed that the activation of ferroptosis might exist in the hippocampi of CUMS-induced mice. The PEBP1-GPX4-mediated ferroptosis could be involved in the antidepressant mechanism of Xiaoyaosan. It also implied that ferroptosis could become a new target for research into the depression mechanism and antidepressant drugs. [ABSTRACT FROM AUTHOR]

Opisina arenosella is one of the main pests harming coconut trees. To date, there have been few studies on the molecular genetics, biochemistry and physiology of O. arenosella at the transcriptional level, and there are no available reference genomes. Here, Illumina RNA sequencing combined with PacBio single-molecule real-time analysis was applied to study the transcriptome of this pest at different developmental stages, providing reference data for transcript expression analysis. Twelve samples of O. arenosella from different stages of development were sequenced using Illumina RNA sequencing, and the pooled RNA samples were sequenced with PacBio technology (Iso-Seq). A full-length transcriptome with 41,938 transcripts was captured, and the N50 and N90 lengths were 3543 bp and 1646 bp, respectively. A total of 36,925 transcripts were annotated in public databases, 6493 of which were long noncoding RNAs, while 2510 represented alternative splicing events. There were significant differences in the gene expression profiles at different developmental stages, with high levels of differential gene expression associated with growth, development, carbohydrate metabolism and immunity. This work provides resources and information for the study of the transcriptome and gene function of O. arenosella and provides a valuable foundation for understanding the changes in gene expression during development. • For the first time, PacBio Iso-Seq and RNA-seq were combined to analyze the Opisina arenosella transcriptomes. • Gene expression profiles were obtained by mapping RNA-seq short sequences to the full-length transcript. • Significant differences in gene expression profiles were found, especially growth and development. • The transcriptomes results help understand the changes in gene expression during the development of Opisina arenosella. [ABSTRACT FROM AUTHOR]

In the copolymerization of acrylamide (Am) and hydroxyethyl acrylate (HEA), the initial product is a carbon chain polymer with hydroxyl and amide side groups. However, in the present work, these two conventional vinyl monomers are combined into a degradable heterochain copolymer by using a phosphazene base, t‐BuP4, as a catalyst. NMR not only confirms that the backbone of the resulting copolymer is composed of ester–ether units and amide units but also suggests that the resulted secondary amide group retains an active hydrogen and can further react with another olefin, which would result in branching or gelation. Thermogravimetric analysis (TGA) shows a signal indicating decomposition at 205–509 °C, verifying the uniform composition of the sample. More interestingly, the synthesized copolymer can dissolve in water and exhibits aggregation‐enhanced emission (AEE). Additionally, the aqueous copolymer solution has a high selectivity and sensitivity for Ba2+, Fe2+, and Fe3+ cations. Hence, it is believed that this method for constructing degradable polymers may offer innovative insights into polymer synthesis and application. [ABSTRACT FROM AUTHOR]

Summary: Modeling and vibration control of a bridge beam system are considered in this article. The beam bridge with both ends fixed can be regarded as an Euler‐Bernoulli beam, which is a typical distributed parameter system. First, the partial differential equations (PDE) model of the bridge was established according to the Hamilton principle. Then, a reasonable distributed control law was designed on the PDE model to eliminate the elastic deformation and suppress the vibration of the bridge. At the same time, uncertainties related to system status were considered during the design of the closed‐loop system. In addition, the possible actuator and sensor faults in the control system were analyzed. Single‐parameter adaptive neural networks were used to estimate the effects of coupling terms for uncertainties and faults. The parameter estimation adaptive law was designed to replace the adjustment of neural network weights, which simplifies the algorithm and facilitates practical engineering applications. Finally, the feasibility of the control system was verified by simulation. [ABSTRACT FROM AUTHOR]

This article studies the stability problem for a three-dimensional string with variable length in the case of input quantization. A nonlinear partial differential equation model is used to depict the dynamic characteristics of the length-varying flexible string with distributed variable parameters. The control signals are effectively mapped from a continuous region to a discrete set of numerical signals before being transmitted through communication channels using quantizers. With no information about quantizers, the vibration of the string is eliminated under the proposed adaptive quantized control despite of the actuator degradation, and the stability of the closed-loop system is demonstrated based on the Lyapunov's direct method. Simulation results are supplied to show the effectiveness of the presented control strategy. [ABSTRACT FROM AUTHOR]

Large propeller lateral loads during ship turning maneuver may cause serious damage on after stern tube bearing. Failure of after stern tube bearing frequently occurs, especially when environmentally acceptable lubricants are used in the ship's stern tube. Therefore, a new design rule for after stern bearing is urgently needed. This paper presents a numerical investigation on the oil film performance of the after stern tube bearing of a super handy-max bulk carrier in turning maneuver. Computational fluid dynamics is adopted to estimate the propeller lateral forces and moments, which are introduced into the shafting alignment calculation. In shafting alignment analysis, the after stern tube bearing is divided into several bearing segments, and the midpoint of journal segments is used to characterize the deflection of the journal centerline. The accurate deflection of the journal center of the after stern tube bearing is obtained through the iteration of the shafting alignment program and Reynolds equation. Moreover, the distribution of oil film pressure and the minimum oil film thickness are recorded. Finally, the criterion for oil film is discussed. [ABSTRACT FROM AUTHOR]

Dynamic properties are vital for the working reliability of aft stern tube bearings. However, the determination of such properties currently involves several simplifications and assumptions. To obtain its dynamic characteristics accurately, the aft stern tube bearing was divided into several bearing segments. The oil film reaction force was considered in the calculation of shaft alignment, and the journal deflection and actual oil film thickness were obtained accordingly. Subsequently, the perturbed Reynolds equation was solved using the finite difference method when the dynamic characteristics of journal bearings with finite width were evaluated. Then, a calculation program was developed and verified by comparing with the results of other studies. Finally, the dynamic characteristics were calculated under different revolutions. The results showed that the stiffness at the vertical direction of the aft stern tube bearing was several times that of the horizontal direction and varied with the revolutions of the shafting system. These findings can provide the foundation for the precise calculation of the journal trajectory under dynamic conditions, as well as for the evaluation of the oil film thickness. Moreover, the results led to favorable conditions for the accurate calculation of the shafting whirling vibration. [ABSTRACT FROM AUTHOR]

• Compound hot extremes did not exacerbate tree growth across 70% of the forests. • Compound hot extremes have started to exacerbate tree growth decline in forests in dry regions. • Growth reduction by compound hot extremes showed a significant increase over the past decades. Under climate warming, the adverse effects of daytime or nighttime hot extremes on forest productivity have been widely reported. However, the impact of compound hot extremes (i.e., combination of daytime and nighttime hot extremes) on tree growth remains unclear. Combining long-term and large-scale tree-ring width and remote-sensing datasets between 1949 and 2020, we examined and compared the effects of individual and compound hot extremes on tree growth and forest productivity in the Northern Hemisphere. Here we showed that compound hot extremes did not exacerbate tree growth and productivity decline compared with individual daytime hot extremes across 70% of the forested area. However, we observed a stronger adverse effect of compound hot extremes on tree growth and productivity compared with individual daytime hot extremes in dry regions. Due to the increased severity and frequency of compound hot extremes, we predicted that compound hot extremes may impose a greater threat to forest productivity and global carbon cycling as compared to individual hot extremes under future climate change. Our results call for effective policies and actions to mitigate the rapidly growing adverse impact of compound hot extremes on forest ecosystems and carbon cycling. [Display omitted] Compound hot extremes generally exacerbate tree growth decline compared with daytime hot extremes in forests in dry regions but not in humid regions across the Northern Hemisphere, possibly due to the counterbalancing effects of daytime and nighttime hot extremes on water availability. [ABSTRACT FROM AUTHOR]

Background The present study aimed to evaluate and compare the efficacy of botulinum toxin type A (BTX-A) injection versus thoracic sympathectomy for idiopathic palmar hyperhidrosis. Methods Fifty-one patients with idiopathic palmar hyperhidrosis were treated with either BTX-A injection or thoracic sympathectomy between March 2013 and April 2016. The severity of palmar hyperhidrosis was qualitatively measured via the Hyperhidrosis Disease Severity Scale (HDSS). All patients completed a questionnaire that detailed the time taken for the treatment to work, local or systemic adverse effects, and pre- and post-treatment severity of hyperhidrosis. The efficacy and adverse effects of the two treatments were compared and analyzed. Results Hyperhidrosis-related quality of life improved quickly and significantly in the BTX-A group (26 patients) and the sympathectomy group (25 patients). Compared with pre-treatment, the HDSS score significantly reduced after treatment in both groups (p < 0.05). All patients in the sympathectomy group had cessation of sweating of the hands after treatment, and this curative effect lasted for 12 months. In contrast, the treatment took more time to work in the BTX-A group, and the curative effect lasted for a much shorter period (3 months). The sympathectomy group had a significantly lesser mean HDSS score than the BTX-A group at 1 week, 3 months, 6 months, 9 months, and 12 months after treatment (p < 0.05). The sympathectomy group experienced more complications than the BTX-A group. Conclusion For palmar hyperhidrosis, thoracic sympathectomy is more effective and has a longer lasting curative effect than BTX-A injection, but thoracic sympathectomy has more complications. [ABSTRACT FROM AUTHOR]

By evaporating the brine containing potassium and ammonium cations compound of the composition K0.48(NH4)0.52MgCl3 · 6H2O was obtained. Its crystal structure was determined by single crystal X-ray analysis. In the crystal, monovalent cation consists of 52% of ammonium and 48% of potassium. The crystal structure consists of a network of (N,K)Cl6 octahedra and Mg(H2O)6 octahedra occupying the cavities in this network. Its unit cell parameters are similar to those of ammonium carnallite. There are obvious differences between the crystal structure of carnallite and the compound. IR spectra show that both carnallite and ammonium chloride characteristic peaks are detected. The thermal behaviour was also investigated. [ABSTRACT FROM AUTHOR]

A new nanoadsorbent A/Fe3O4/GO (AFG) is developed for eliminating Cs+ from water by anchoring Fe3O4 nanoparticles onto graphene oxide (GO/Fe3O4) and in situ controllable growing nanocrystal of ammonium 12-molybdophosphate (A) on the surface of GO/Fe3O4 with a simple procedure at room temperature. AFG shows a high adsorption capacity for Cs+ (Qmax = 82.71 mg g−1) and fast kinetics (> 88.83% elimination efficiency within only 1 min and reaches the end equilibrium in about 10 min). It presents good selectivity for Cs+ in a wide pH range (2.0-10). Furthermore, it can be recovered from water with easily magnetic separation. [ABSTRACT FROM AUTHOR]

Poly(ester-ether)s are biodegradable copolymers with excellent performance. These copolymers are used as scaffolds for tissue engineering and degradable materials in packaging. However, their synthesis procedures are generally tedious which restrict their widespread applications. Furthermore, the inadequate availability of their commercial monomers also hampers their production. Herein, we reported a facile strategy for the synthesis of linear and branched poly(ester-ether)s using a polyol and methyl acrylate (MA) as monomers. During the polymerisation, the vinyl bond of MA reacts with the hydroxyl groups of a polyol following an oxa-Michael polyaddition mechanism. Simultaneously, esterification takes place between the ester group of MA and polyol. As a result, poly(ester-ether)s were successfully synthesised by combining these two different types of reactions into one polymerisation system. The linear and branched structures of the products were confirmed by the nuclear magnetic resonance and triple-detector gel permeation chromatography. This work provides a facile strategy for the synthesis of poly(ester-ether)s from commercially available monomers. [ABSTRACT FROM AUTHOR]

In this study, modified biochar (BRB) was prepared from rice straw by ball milling technique and used for the adsorption of methylene blue (MB) in wastewater. The BRB was characterized by SEM, FTIR and XPS, and the adsorption model and Box–Behnken design were used to optimize the five influencing factors. The results showed that the ball milling technique could increase the content of functional groups (–OH, C=C and C–O, etc.) and aromatic structures on the surface of biochar, thus facilitating the removal of MB. The isotherm model was consistent with the Langmuir adsorption model (R2 = 0.947) and the maximum adsorption capacity was 50.27 mg/g. The adsorption kinetics was consistent with the pseudo-second-order kinetic model (R2 = 1) and the adsorption rate was mainly controlled by chemisorption. The thermodynamic model confirmed that the adsorption process was a spontaneous heat absorption reaction. The maximum adsorption efficiency was 99.78% under the optimal conditions (40℃, pH 8, reaction time = 90 min, dosing amount = 0.1 mg), and the adsorption efficiency could be improved by increasing the pH and BRB dosing amount. The surface functional groups and crystal structure properties of BRB were the main determinants of adsorption, and it was clarified that physical adsorption, electrostatic attraction and π-π interaction were the main mechanisms for the adsorption of MB by BRB. The main mechanisms were clarified. Therefore, BRB is an economic, efficient and green adsorption material with good potential for the removal of dye pollutants in the aqueous environment. [ABSTRACT FROM AUTHOR]

In this study, FeOOH was immobilized on the biodegradable root powder, abbreviated as RP, of long-root Eichhornia crassipes , a kind of waste biomass, to improve the adsorption performances for aqueous arsenic contaminants. The adsorption kinetics and thermodynamics experiments showed that the adsorption rates and capacities of the root powder for arsenate (As(V)) and arsenite (As(III)) were both enhanced markedly after modification with FeOOH. The adsorption of As(V) and As(III) by the modified root powder, abbreviated as MRP, could arrive at equilibrium in 50 min and the saturated adsorption capacities reached up to 8.67–9.43 mg/g for As(V) and 5.21–5.65 mg/g for As(V) at temperature of 10–50 °C, respectively. Besides, the effect of pH and ionic strength on adsorption was investigated and the results showed that the optimum pH for the arsenic adsorption using the MRP was 9.0 and the As(V) adsorption was more sensitive to ionic strength. Furthermore, the complexation of hydratable hydroxyls on FeOOH with arsenic contaminants was concluded as the adsorption force according FTIR and XPS analyses. The MRP used could be regenerated via 0.4 mol/L NaOH solution and no apparent adsorption capacity losses appeared after 6 cyclic utilizations. [ABSTRACT FROM AUTHOR]

Reverse osmosis (RO) membranes have been widely used in the field of membrane separation. However, most of the commercial RO membranes are fabricated based on a polysulphones- or polyethersulfone-modified polyethylene glycol terephthalate (PET) support, which are thick and exhibit poor solvent resistance. In this study, polyethylene (PE) battery membranes without any hydrophilic modification were directly used to prepare PE-RO membranes. The structures of the products were confirmed via attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The resulting RO membrane prepared with 0.05 wt.% of trimesoyl chloride and 2 wt.% of m-phenylenediamine exhibited a water flux of 12.61 L m−2 h−1 with a desalination (NaCl) rate of 98.6%. The thickness of the PE-RO membrane is 80% of the thickness of the traditional RO membranes and hence has a wider application as a separation membrane. [ABSTRACT FROM AUTHOR]

Aliphatic polyesters have been widely used in environmental and biomedical engineering, but a lack of functional groups limits their applications. Here, we reported a facile approach to synthesize vinyl functional polyester via the ring opening copolymerization of ε-caprolactone (CL) and allyl glycidyl ether (AGE). NMR analysis confirmed the copolymeric structures and suggested that the copolymerization depended on the epoxide ring of AGE rather than vinyl group. The amount of AGE incorporated into the copolymers ( F AGE ) increased with the amount of epoxide monomer feed with a maximum incorporation of 16.7%. Increasing temperature helped AGE to incorporate into the copolymer, however, accompanying with lots amount of AGE homopolymers. The resulting copolymer was successfully post-functionalized by thiol-end click, epoxidation, and bromination reactions depending on the reactivity of pendent ally groups. This facile and efficient approach can be used to functionalize biodegradable polymers and synthesize some new polymers under mild conditions. [ABSTRACT FROM AUTHOR]

Mesoporous magnetic AMP polyhedric composites mag-AMP (AMP/Fe 3 O 4 ) with highly efficient Cs + adsorption capacity has been successfully explored by means of a simple interface-induced co-assembly method at room temperature for the first time. Taking advantage of the mesoporous material and magnetic composite, mag-AMP composites show efficient Cs + adsorption capability (maximum adsorption capacity, 83.33 mg/g) and reach an equilibrium state within only 5 min. The Langmuir isotherm model fitted better with the adsorption data than Freundlich isotherm model. The fast adsorption process follows pseudo-second-order kinetics. The obtained adsorbent also shows high Cs + -sieving selectivity and could be applied in kinds of solutions even in the strong acidic medium. It could also be used effectively to separate Cs + from wastewater even with trace (µg/L) concentrations. The removal mechanism of Cs + for mag-AMP may be the joint action of both chemisorption (NH 4 + -exchange) and physisorption due to the weak van der waals forces. The adsorbent was inlaid with Fe 3 O 4 NPs which make it easily recovered from polluted solution with magnetic separation. More importantly, the synthesis of mag-AMP is simple and low-cost with environmental friendly raw. Thus, the adsorbent of mag-AMP has extensive applicability for the removal of Cs + from nuclear wastewater. [ABSTRACT FROM AUTHOR]

Anionic hybrid copolymerization of vinyl and cyclic monomers provides a powerful strategy to synthesize heteropolymers. Yet, there are some open questions regarding its mechanism and the structure of the resulted polymer. We reported that the copolymer (Poly(MMA- co -CL)) of methyl methacrylate (MMA) and ε-caprolactone (CL) via such copolymerization was random. However, a recent study proposed that the copolymer might be simple graft one with poly(methyl methacrylate) (PMMA) as the main chain and poly(ε-caprolactone) (PCL) as the graft chain. In this study, we synthesized a model graft copolymer (PMMA- g -PCL) by using a combination of reversible complexation-mediated polymerization and ring-opening polymerization, and made comparison with Poly(MMA- co -CL) in their properties and hydrolysis. Differential scanning calorimeter (DSC) measurements show that the graft copolymer PMMA- g -PCL possesses two glass transitions and a melt peak. In contrast, Poly(MMA- co -CL) exhibits only one glass transition without a melt peak because it is amorphous, clearly indicating that it is random. Proton nuclear magnetic resonance (1H NMR) measurements reveal that the hydrolysis of PMMA- g -PCL yields only PMMA oligomers. However, the hydrolyzed products of Poly(MMA- co -CL) consist of MMA and CL units. The facts further indicate that the copolymer Poly(MMA- co -CL) is random. Considering that the transesterification reactions are unavoidable in the anionic hybrid copolymerization, the copolymer should consist of random main chain and random branches. [Display omitted] • The present study demonstrates that anionic hybrid copolymerization of MMA and CL generally yields random copolymer but not graft copolymer. • Transesterification is not the essential step in the anionic hybrid copolymerization, but it can cause branching of the copolymer. • The hybrid copolymer of MMA and CL consists random main chain and random branches. [ABSTRACT FROM AUTHOR]

This paper mainly focuses on designing a distributed observer-based controller for a flexible-link manipulator bonded with piezoelectric actuators. The dynamic model of the link can be taken as an Euler–Bernoulli beam and takes on the form of partial differential equations (PDEs). The proposed observer, which is proven exponentially stable, has the ability to estimate infinite dimensional states, and only the boundary practical measurement values are needed. A novel distributed observer-based controller is subsequently developed to make the joint position track a desired trajectory and rapidly regulate vibrations on the whole beam, which is the main contribution of the paper. The closed-loop system is guaranteed exponentially stable by theoretical analysis and its favorable performance is demonstrated by numerical simulations. [ABSTRACT FROM AUTHOR]

A new nanocomposite, called FPPB, was prepared by the in situ synthesis of a Prussian blue (PB) nanocrystal within Fe 3+ crosslinking poly(acrylic acid) (PAA) resin for the highly efficient and rapid separation of radiocesium from water. The adsorption of Cs + by FPPB follows the Langmuir and Freundlich isotherm model with distribution coefficients touched 1.15 × 10 5 mL/g and a good adsorption capacity of 72.47 mg/g (pH ≈ 7). FPPB displays high adsorption capacity for Cs + capture under a wide pH range (4.0–10). The kinetics of Cs + uptake by FPPB is fast (>90% elimination capacity of relatively low Cs + concentrations during only 20 min of Cs + /FPPB contact) and fit well with the pseudo-second-order kinetic model. This should be attributed to the high dispersion of PB nanoparticles. The adsorption Cs + from complex solutions containing various competitive cations in large excess was also effective. FPPB is a cost-effective sorbent and could be developed by only stirring using environmental friendly and inexpensive materials at room temperature. Furthermore, the FPPB-Cs + can be easily retrieved from water with sieve. It is expected that the as-prepared FPPB has extensive applicability in the elimination of radiocesium from nuclear wastewater. [ABSTRACT FROM AUTHOR]

Vinyl-functionalized hyperbranched polymers (HBPs) have attracted much attraction because their pendant vinyl groups can be further modified for a required application. However, the syntheses of these polymers are difficult, because the cross-linking is inevitable during the polymerization reaction. The present work reports a new, facile, one-step strategy for the synthesis of vinyl-functionalized HBPs v ia the self-condensing anionic copolymerization of commercially available allyl methacrylate and hydroxyethyl methacrylate with a monomer conversion approaching 100% at room temperature. The hyperbranched structures were confirmed by triple-detection size exclusion chromatography. The pendent vinyl groups of the resulting polymer were successfully modified by a “thiol-ene” reaction. This method provides a facile approach for preparing vinyl-functionalized HBPs with excellent monomer conversions under mild conditions, and will be useful in materials chemistry. [ABSTRACT FROM AUTHOR]

A novel biocompatible and biodegradable copolymer was synthesized by one-step hybrid copolymerization of ε -caprolactone (CL) and 2-( N , N -dimethylamino) ethyl methacrylate (DMAEMA) employing (1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phophoranylidenamino]-2Λ5,Λ5-catenadi(phosphazene) ( t -BuP 4 ) as a catalyst. The as-synthesized copolymer was betainizated resulting in a zwitterionic copolymer poly (CL- co - z DMAEMA) and the structure of the zwitterionic copolymer was confirmed by the FT-IR, NMR, and XPS measurements. The results of dynamic light scattering (DLS) show that this zwitterionic copolymer can self-assemble into stable micelles. The results of quartz crystal microbalance with dissipation (QCM- D ) analysis and MTT measurement suggest that this zwitterionic copolymer possess better protein resistance and lower cell cytotoxicity in vitro in comparison with the cationic copolymer. The pyrene solubilization measurement of copolymers poly (CL- co - z DMAEMA) indicates an excellent pyrene solubilization capacity. These zwitterionic polymer micelles can release drugs in response to specific signals, such as temperature, pH, and enzymes and have a potential application in drug delivery and gene therapy due to their good antifouling, low cytotoxicity and high pyrene solubilization. [ABSTRACT FROM AUTHOR]

This paper focuses on designing an observer for a flexible-link manipulator based on the partial differential equation (PDE) dynamic model. The main contribution of this observer׳s novel design is its ability to estimate vibratory, infinite dimensional states requiring only the practical measurement values of boundary positions. The proposed observer is proven asymptotically stable by theoretical analysis. The vibration of the flexible link is eliminated with a PD control. Favorable performance of the closed-loop system is demonstrated by simulations. [ABSTRACT FROM AUTHOR]

A simple method for the synthesisof graphene oxide (GO) from expandedgraphite using an ultrasonic cleaner is described. Due to the synergisticeffect between intercalation (oxidation) and ultrasonication, thismethod showed strongly decreased demand for acid, time saving/lessenergy consuming, high productivity and without the release of toxicgas(es) than Hummers’ method. Single sheets of GO with layerspacing of ∼1 nm were obtained in less than 1 h. This procedurewas safe and expected to be applicable for the scale production ofGO. Both graphene oxide film and reduced graphene oxide (rGO) filmshowed good bending flexibility. [ABSTRACT FROM AUTHOR]

Biomedical polyurethane (BPU) porous membranes with controlled morphology and excellent permeability and mechanical properties were prepared via a method involving a phase inversion induced by water micro-droplets, which were generated by an ultrasonic atomizer. The cross-section morphology, air permeability and mechanical properties of the porous membranes were investigated. The SEM images demonstrated that the adjacent pores were connected by a micro-hole, serving as a “backdoor” for the pore. An interconnected porous structure was obtained, improving the air permeability of the BPU membrane relative to the membrane produced by immersion precipitation. Our studies indicated that the diameter of the pores in the membrane depended on the solution viscosity, allowing porous membranes with a desired morphology to be obtained by adjusting the polymer concentration and solution viscosity. The application of micro-droplets of water during membrane preparation reduced the exchange rate between the solvent and nonsolvent, resulting in the microphase separation of polymer molecules and the formation of a uniform porous structure in the membrane, which improved the air permeability and mechanical properties of the BPU porous membranes. This is a simple and effective preparation method for high-performance porous membranes with potential applications in tissue engineering scaffolds, controlled-release drug delivery and vascular grafts. [ABSTRACT FROM AUTHOR]

Highlights: [•] Magnetic prussian blue/graphene oxide–calcium alginate microbeads were prepared. [•] Microbeads could be separated rapidly by an external magnetic field. [•] Adsorption properties for Cs+ of microbeads were studied. [•] The microbeads present high efficiency and good selectivity to Cs+. [•] The microbeads are convenient for treatment of cesium-contaminated water and soil. [ABSTRACT FROM AUTHOR]

A new method for impact source localization in a plate is proposed based on the multiple signal classification (MUSIC) and wavelet analysis. For source localization, the direction of arrival of the wave caused by an impact on a plate and the distance between impact position and sensor should be estimated. The direction of arrival can be estimated accurately using MUSIC method. The distance can be obtained by using the time delay of arrival and the group velocity of the Lamb wave in a plate. Time delay is experimentally estimated using the continuous wavelet transform for the wave. The elastodynamic theory is used for the group velocity estimation. [ABSTRACT FROM AUTHOR]

Abstract: The location template matching (LTM) method is occasionally used in the area of structural health monitoring and human–computer interface system when the location of impact on an object is needed to be identified. In general, the LTM method utilizes the cross-correlation (or the correlation coefficient) between two time signals, and its performance is influenced by many factors such as the spatial resolution of the pre-defined reference points, the frequency bandwidth of a signal and the length of data, etc. In addition, the correlation based LTM method often needs many sensors to improve the accuracy of identification. To overcome these disadvantages, a group delay based LTM method (namely G-LTM) is introduced in this paper. Particularly, the proposed method uses the group delay of a fictitious linear time-invariant system as a measure of similarity. The experimental results verify a high quality of the G-LTM method by maintaining 100% accuracy for all the different grid spacing while the accuracy of the correlation based LTM method decreases significantly as the grid spacing becomes smaller. [Copyright &y& Elsevier]

Poly( ϵ-caprolactone- co- tert-butyl methacrylate) (CL- co-BMA) random copolymer is synthesized via hybrid copolymerization with 1- tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phophoranylidenamino]-2Λ5,4Λ5-catenadi(phosphazene) ( t-BuP4) as the catalyst. The copolymer is hydrolyzed into poly( ϵ-caprolactone- co-methacrylic acid) (CL- co-MAA), a charged copolymer. Nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis measurements indicate that cyclic ester and vinyl monomer form a random copolymer. The degradation of the copolymers has also been studied by use of quartz crystal microbalance with dissipation. [ABSTRACT FROM AUTHOR]

Poly(ε-caprolactone- co-ethylene carbonate- co-ethylene oxide) (CL- co-EC- co-EO) copolymer was synthesized via ring-opening copolymerization of ε-caprolactone (CL) and 1,3-dioxolan-2-one with a metal-free phosphazene catalyst ( t-BuP). The monomer conversion and molecular weight in CL- co-EC- co-EO copolymer were characterized by nuclear magnetic resonance and gel permeation chromatography, respectively. Moreover crystallization behavior of CL- co-EC- co-EO copolymer was investigated by differential scanning calorimeter and wide-angle X-ray diffraction. The enzymatic degradation of the copolymer has been investigated by quartz crystal microbalance with dissipation. Our studies demonstrate that as PCL content in the copolymer decreases, the degree of crystallinity and crystal size decrease, while the enzymatic degradation rate increases. The copolymer exhibits layer-by-layer degradation. [ABSTRACT FROM AUTHOR]

Abstract: Composite nanofibrous membranes of water-soluble N-carboxyethyl chitosan/poly(vinyl alcohol)/silk fibroin nanoparticles were successfully fabricated by electrospinning. The composite nanofibers were subjected to detailed analysis by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). SEM results investigated that the morphology and diameter of the nanofibers were affected by silk fibroin nanoparticles content. XRD and DSC demonstrated that there was intermolecular hydrogen bonding among the molecules of carboxyethyl chitosan, silk fibroin and PVA. The crystalline microstructure of the electrospun fibers was not well developed. The indirect cytotoxicity assessments of the nanofibers were studied. The result showed the nanofibers had good biocompatibility. This novel electrospun matrix would be used as potential wound dressing for skin regeneration. [Copyright &y& Elsevier]

Abstract: Quaternization-functionalized chitosan fibers were successfully prepared by using 2,3-epoxypropyl trimethyl ammonium chloride as a quaternized reagent reacted with chitosan fiber. FTIR and 1H NMR were used to characterize the structure of quaternized chitosan fibers (QCFs). The swelling behavior and mechanical property of QCFs were studied. The results showed that, QCFs had higher liquid absorption capacity than chitosan fiber, while the tensile strength and elongation at break of QCFs were lower than those of chitosan fiber. The antibacterial activity of the QCF had been evaluated by Gram-positive bacteria Staphylococcus aureus (S. aureus). The results indicated that, the antibacterial activity of QCF against S. aureus was stronger than that of chitosan fiber. Indirect cytotoxicity assessment of the fibers indicated that QCF was nontoxic to the L929 cell with relatively low extraction concentration. This novel fiber would be used as potential wound dressing for skin regeneration. [Copyright &y& Elsevier]

Abstract: Copolymerization of methyl methacrylate (MMA) and acrylate terminated poly(ethylene oxide-co-ethylene carbonate) (PEOC) macromonomer yields graft copolymer with PEOC side chains. By use of quartz crystal microbalance with dissipation (QCM-D), we have investigated the adsorption of proteins on the surface constructed by the copolymer in seawater. It shows the polymeric surface exhibits protein resistance depending on the content of the side chains. Marine field tests show the protein resistant surface can effectively inhibit marine biofouling for more than 12 weeks. [Copyright &y& Elsevier]

Polyamide 1010 (PA1010) had been prepared by in situ melt polycondensation in presence of silica nanospheres with amine groups on the surfaces (SiO2NH2). Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermal gravimetric analysis (TGA) measurements demonstrated that the nanosphere surface was grafted with PA1010 chains. Wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) measurements showed that the PA1010/SiO2NH2 nanocomposites had a lower degree of crystallinity (χc) in comparison with PA1010 and PA1010/SiO2 nanocomposites. Dynamic mechanical analysis (DMA) indicated that SiO2NH2 nanospheres improved glass transition temperature ( Tg), tensile strength and storage modulus of PA1010 since SiO2-NH2 nanospheres limited the mobility of PA1010 chains. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The realization of silicon-based light sources has been the subject of a major research and development effort worldwide. Such sources may help make integrated photonic and electronic circuitry more cost-effective, with higher performance and greater energy efficiency. The hybrid approach, in which silicon is integrated with a III-V gain medium, is an attractive route in the development of silicon lasers because of its potential for high efficiency. Hybrid lasers with good performance have been reported that are fabricated by direct growth or direct wafer-bonding of the gain medium to silicon. Here, we report a membrane reflector surface-emitting laser on silicon that is based on multilayer semiconductor nanomembrane stacking and a stamp-assisted transfer-printing process. The optically pumped laser consists of a transferred III-V InGaAsP quantum-well heterostructure as the gain medium, which is sandwiched between two thin, single-layer silicon photonic-crystal Fano resonance membrane reflectors. We also demonstrate high-finesse single- or multiwavelength vertical laser cavities. [ABSTRACT FROM AUTHOR]

Copolymerization of ε-caprolactone and methyl methacrylatewith (1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phophoranylidenamino]-2Λ5,Λ5-catenadi(phosphazene)(t-BuP4) as the catalyst has been studied.Nuclear magnetic resonance (NMR) and differential scanning calorimetry(DSC) measurements indicate that the cyclic ester and vinyl monomerform a random copolymer. Thermogravimetric analysis (TGA) measurementsdemonstrate that such a random copolymer exhibits a decompositiontemperature higher than those of the corresponding homopolymers. Thepresent study reveals a “hybrid copolymerization” i.e.,a combination of vinyl polymerization and ring-opening polymerization,which makes the incorporation of cyclic and vinyl monomers into thesame polymer chain possible. Hybrid copolymerization is expected toproduce a number of new interesting polymers. [ABSTRACT FROM AUTHOR]

Substantial oxygen enrichment is observed in the naturalair hydratesformed in Arctic and Antarctic ice sheets. Inspired by this phenomenon,a novel air separation method, utilizing hydrate crystallization,is proposed in our work. The three-phase equilibrium pressure forthe air + water system is greater than 15 MPa as the temperature isupon ice point, which makes the air separation impractical by hydrateformation under mild temperature conditions. So, some additives wereselected to reduce the phase equilibrium pressure of air hydratesat a fixed temperature. In this work, hydrate dissociation conditionsfor the air + tetrahydrofuran (THF) + water system (x= 0.0300 and 0.0500), the air + cyclopentane (CP) + water system(x= 0.0300 and 0.0556), and the air + tetra-n-butyl ammonium bromide (TBAB) + water system (w= 0.20 and 0.30) were measured in the temperature rangesof (279.7 to 290.5) K, (284.0 to 296.2) K, and (283.4 to 288.0) K,respectively. The comparison result shows that, in the pressure rangeof (0 to 1.5) MPa, the promotion effect of these three additives onthe air + water system follows TBAB > CP > THF. [ABSTRACT FROM AUTHOR]

A pot experiment was carried out to study the growth and pungency of Allium fisutulosum grown in Perlite as affected by colonization by the arbuscular mycorrhizal (AM) fungi Glomus etunicatum, Glomus vesiforme, and by ammonium (NH+4):nitrate (NO-3) ratios of 5:95, 50:50, and 95:5 in 4 mM solutions. Plants were grown in a greenhouse for 20 weeks and then harvested. In general, NH+4:NO-3 ratio of 50:50 supplied resulted in the highest shoot dry weight regardless of non-mycorrhizal and mycorrhizal plants while the effect of inoculation treatment on plant biomass was not significant. The plant sulfur (S) concentrations were usually higher in mycorrhizal plants than controls irrespective of nitrogen ratio and therefore inoculation with G. etunicatum increased the enzyme produced pyruvic acid (EPY) while inoculation with G. versiforme decreased the EPY compared with the non-mycorrhizal plants. In general, shoot pungency was lowest when NH+4:NO-3 ratio of 95:5 supplied irrespective of mycorrhizal treatment. Colonization by both AM fungi made a substantial contribution to spring onion sulfur nutrient status but show different way on flavor characteristics of host plants. [ABSTRACT FROM AUTHOR]

Traditional Chinese Medicine (TCM) documented about 100,000 formulae during past 2500 years. To use and customize them by modern pharmaceutical industry, we make an interdisciplinary effort to study the activity of new drug research and development (R&D) in TCM by introducing data mining approaches to it. We used the migraine formulae as a training set to investigate the possibility of developing new prescription by means of data mining. The activity of new drug R&D of TCM consists of two steps. The first step is to discover new prescriptions (candidates for drugs) from migraine formulae. We present an unsupervised clustering approach based on data mining theory to address the problem in the first step and automatically discover ten new prescriptions from the formulae data. The second step is to develop and optimize the prescriptions discovered by current biomedical approaches. Since Ligusticum chuanxiong Hort (LCH), a kind of herb, is often used to treat migraine and appears in the new prescriptions, we use it as an example and apply supervised regression method based on data mining theory to study the drug R&D activity of TCM. We revised two linear regression methods in order to establish the nonlinear association between three chemical ingredients of LCH and corresponding pharmacological activity and used it to predict the activities. The association is validated by in vitro experiments and we found that the experimental results are consistent with the prediction. Unsupervised clustering and supervised regression cover most part of data mining theory, which means that data mining approaches play a crucial role in new drug R&D in TCM and present a better solution to establish the platform of drug R&D in TCM. [ABSTRACT FROM AUTHOR]

High-quality ZnO thin films have been grown on single-crystal diamond substrates with (111) orientation, by low-pressure metal-organic chemical vapour deposition. X-ray diffraction spectra and photoluminescence (PL) spectra clearly showed that the quality of ZnO films was improved by the two-step growth method. Strong ultraviolet emissions and weak deep-level emissions with different intensity were both observed in the room-temperature PL spectrum. The change of surface morphology was also studied by atomic force microscopy. Zn and O elements in the deposited ZnO/diamond films were investigated by x-ray photoelectron spectroscopy, in which the statistical result of the ratio for O/Zn atoms of samples was about 1. Raman scattering was performed at room temperature. The E2, A1(TO) and E1(TO) mode peaks were seen at 437.46, 383 and 414.87 cm-1, which indicated a high crystalline quality for our samples. [ABSTRACT FROM AUTHOR]

High-quality ZnO films were grown on epi-GaN predeposited on c-Al2O3 substrates using low-pressure metal-organic chemical vapor deposition (MOCVD). Detailed study of the X-ray diffraction spots and patterns by different diffractometers showed high structural perfection of the zinc oxide layer, which indicated that the growth of ZnO film was strongly c-oriented. The full-width at half-maximum (FWHM) of the ω-rocking curve was 0.39°. Surface morphology of the films studied by AFM showed that the growth of the ZnO film followed the regular hexagonal column structure with about 500 nm grain diameter. Zn and O elements in the deposited ZnO/GaN/Al2O3 films were investigated and compared by X-ray photoelectron spectroscopy (XPS), in which the dissociative O and Zn atom peak was hardly observed. The ratio of O/Zn atoms of the film was about 1 with O-rich. Photoluminescence spectra of the ZnO films grown on epi-GaN showed dominating exciton emission peak, and the deep-level emission which was obvious on ZnO/Al2O3 film had hardly been observed. [Copyright &y& Elsevier]

Tissue engineered heart valves (TEHVs) demonstrates the potential for tissue growth and remodel, offering particular benefit for pediatric patients. A significant challenge in designing functional TEHV lies in replicating the anisotropic mechanical properties of native valve leaflets. To establish a biomimetic TEHV model, we employed melt-electrowriting (MEW) technology to fabricate an anisotropic PCL scaffold. By integrating the anisotropic MEW-PCL scaffold with bioactive hydrogels (GelMA/ChsMA), we successfully crafted an elastic scaffold with tunable mechanical properties closely mirroring the structure and mechanical characteristics of natural heart valves. This scaffold not only supports the growth of valvular interstitial cells (VICs) within a 3D culture but also fosters the remodeling of extracellular matrix of VICs. The in vitro experiments demonstrated that the introduction of ChsMA improved the hemocompatibility and endothelialization of TEHV scaffold. The in vivo experiments revealed that, compared to their non-hydrogel counterparts, the PCL-GelMA/ChsMA scaffold, when implanted into SD rats, significantly suppressed immune reactions and calcification. In comparison with the PCL scaffold, the PCL-GelMA/ChsMA scaffold exhibited higher bioactivity and superior biocompatibility. The amalgamation of MEW technology and biomimetic design approaches provides a new paradigm for manufacturing scaffolds with highly controllable microstructures, biocompatibility, and anisotropic mechanical properties required for the fabrication of TEHVs. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is the second largest group of neurodegenerative diseases, and its existing drug treatments are not satisfactory. Natural cell membrane drugs are used for homologous targeting to enhance efficacy. In this study, microfluidic electroporation chip prepared mesenchymal stem cell-derived neuron-like cell membrane-coated curcumin PLGA nanoparticles (MM-Cur-NPs) was synthesized and explored therapeutic effect and mechanism in PD. MM-Cur-NPs can protect neuron from damage, restore mitochondrial membrane potential and reduce oxidative stress in vitro. In PD mice, it also can improve movement disorders and restore damaged TH neurons. MM-Cur-NPs was found to be distributed in the brain and metabolized with a delay within 24 h. After 1 h administration, MM-Cur-NPs were distributed in brain with a variety of neurotransmitters were significantly upregulated, such as dopamine. Differentially expressed genes of RNA-seq were enriched in the inflammation regulation, and it was found the up-expression of anti-inflammatory factors and inhibited pro-inflammatory factors in PD. Mechanically, MM-Cur-NPs can not only reduce neuronal apoptosis, inhibit the microglial marker IBA-1 and inflammation, but also upregulate expression of neuronal mitochondrial protein VDAC1 and restore mitochondrial membrane potential. This study proposes a therapeutic strategy provide neuroprotective effects through MM-Cur-NPs therapy for PD. Microfluidic chips prepared mesenchymal stem cell-derived neuron-like cell encapsulation promotes curcumin nanoparticles to improve mobility disorders in Parkinson's disease. [ABSTRACT FROM AUTHOR]