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The visually secure image encryption scheme is an effective image encryption method, which embeds an encrypted image into a visual image to realize a secure and secret image transfer. This paper proposes a merging compression and encryption chaos image visual encryption scheme. First, a dictionary matrix D is constructed with the plain image by the K-SVD algorithm, which can encrypt the image while sparsing. Second, an improved Zeraoulia-Sprott chaotic map and logistic map are employed to generate three S-Boxes, which are used to complete scrambling, diffusion, and embedding operations. The secret keys of this scheme contain the initial value of the chaotic system and the dictionary matrix D, which significantly increases the key space, plain image correlation, and system security. Simulation shows the proposed image encryption scheme can resist most attacks and, compared with the existing scheme, the proposed scheme has a larger key space, higher plain image correlation, and better image restoration quality, improving image encryption processing efficiency and security. [ABSTRACT FROM AUTHOR]

How to improve the storage density and solve the sneak path current problem has become the key to the design of nonvolatile memristive memory. In this paper, a high storage density and high reading/writing speed 3D crossbar array non-volatile memory based on pure memristors is proposed. The main works are as follows: (1) an extensible memristive cluster is proposed, (2) a memristive switch is designed, and (3) a 3D crossbar array non-volatile memory is constructed. The memory cell of the 3D crossbar array non-volatile memory is constructed by pure memristors and can be extended by adding memristor in a memristive cluster or adding memristive clusters in a memory cell to realize multi-value storage. The memristive switch can effectively reduce the sneak path current effect. The pure memristive memory cell solves the conflict between the storage density and sneak path current effect and greatly improves the storage density of memory cells. Furthermore, the 3D cross-array structure allows different memory cells on the same layer or different layers to be read and written in parallel, which greatly improves the speed of reading and writing. Simulations with PSpice verifies that the proposed memristive cluster can realize stable multi-value storage, has higher storage density, faster reading and writing speed, fewer input ports and output ports, better stability, and lower power consumption. Moreover, the structure proposed in this paper can also be used in the circuit design of the neuromorphic network, logic circuit, and other memristive circuits. [ABSTRACT FROM AUTHOR]

Sunset yellow (FCF), a commonly used food additive, can brighten foods, but the improper amount of addition can also cause various diseases. Herein, the fluorescence sensor CDs‐PTD for detecting FCF is synthesized by functionalizing carbon dots (CDs) with 3,4,9,10‐pertetracarboxylic dianhydride (PTD). The prepared CDs‐PTD shows excitation‐independent fluorescence behavior with maximum fluorescence emission at 553 nm under 490 nm excitation and high quantum yields (21.4%). With the presence of FCF, the fluorescence of the sensor is quenched due to fluorescence resonance energy transfer (FRET). The CDs‐PTD exhibits excellent selectivity and sensitivity toward FCF in the range of 0–180 × 10−6m with a low detection limit of 106.8 × 10−9m. In addition, the sensor is applied to the detection of FCF in beverage samples with recoveries ranging from 97% to 106%. And a portable CDs‐PTD/agarose gel reagent strip is prepared for the assessment of FCF content within 15 min. The CDs‐PTD can be an ideal sensor for detecting FCF in food, and provides a new idea for the detection of food additives. [ABSTRACT FROM AUTHOR]

We here investigate the effects of tropical cyclone (TC)‐induced rainfall asymmetries driven by vertical wind shear on ocean salinity and temperature response to TCs using satellite and in situ observations. On average, TCs tend to initially freshen the ocean surface due to heavy rainfall and subsequently salinity from upwelling and vertical mixing, with strongest surface salinification on the right‐hand side of the Northern Hemisphere TCs. The direction of shear has been found to control the location of maximum TC rainfall, resulting in more freshwater accumulation on the right‐hand side of the right‐sheared storms. The accumulated freshwater strengthens salinity stratification and inhibits right‐side biased vertical mixing, reducing subsequent surface salinification by 0.15–0.3 psu and slightly suppressing the surface cooling by about 0.15°C, relative to left‐sheared storms. Thus, the directionality of shear can impact ocean‐TC coupling. Plain Language Summary: The cooling of the ocean surface by tropical cyclones (TCs) can influence the evolution of TC intensity and is driven by vertical exchanges in the ocean, which tend to be strongest on the right‐hand side of the Northern Hemisphere TCs. TC‐induced changes in salinity can influence upper ocean stability, a key influence on ocean dynamics. In this study, we investigate the influence of environmental vertical wind shear direction on TC‐induced rainfall asymmetries, and their subsequent impacts on the ocean salinity and temperature response to TCs with satellite observations and Argo profiles. Here we show that more freshwater is accumulated on the right‐hand side when the vertical wind shear direction is towards the right of storm motion in the Northern Hemisphere, which reduces the TC‐induced surface salinity increase and causes weaker vertical mixing on the right‐hand side of the storm. Since the vertical mixing is strongest on the right‐hand side of the Northern Hemisphere storms, more freshwater on the right‐hand side also results in muted surface cooling. Key Points: Vertical wind shear impacts the ocean response to tropical cyclones through affecting the tropical cyclone rainfall distributionMore freshwater to the right of the right‐sheared storms increases salinity gradient and inhibits mixing, reducing surface salinificationThe restrained mixing on the right‐hand side slightly suppresses the surface cooling and chlorophyll‐a enhancement [ABSTRACT FROM AUTHOR]

As image is an important way of information representation, researchers pay more and more attention on image encryption. In order to improve the performance of image encryption, a novel image encryption scheme based on a hybrid cascaded chaotic system and sectoral segmentation is proposed in this paper. Hybrid cascaded chaotic system has a larger key space, higher complexity, more sensitivity to initial conditions. Four chaotic sequences relevant to a plain image are generated by this system, which strengthen plaintext correlation and the randomness. During the scrambling process, sectoral segmentation focuses on how to extract a sequence from the disk storing data, which can not only reduce the correlation between the three components of the image, but also hide image information to a large extent. Further, a DNA algorithm is used in the diffusion process. Simulation shows that the proposed scheme can effectively resist various attacks and improve the encryption performance. [ABSTRACT FROM AUTHOR]

With the rapid science and technology advancement, the oil-water separation in oily wastewater has become an urgent problem, especially the emulsified oil-water mixtures. Hollow carbon spheres (HCSs) have tremendous potential in separating oil-water emulsions due to their rich porous channels and high surface-to-volume ratio. In this work, as-prepared chitosan/poly(γ-glutamic acid) nanoparticles crosslinked by Ni2+ (Ni2+/CS/γ-PGA NPs) were used as carbon precursor to fabricate HCSs. This strategy separated the formation process of the biomolecular microspheres and the carbonization process. Especially, the Ni2+/CS/γ-PGA NPs were fabricated from the self-assembly of chitosan and γ-PGA in aqueous solution and the crosslinking of Ni2+ via the electrostatic interactions, facilitating the formation of biomolecular microspheres and making the usable of biomolecule-based carbon precursors diversity. After lyophilization, Ni2+/CS/γ-PGA NPs powder was obtained, which was then carbonized in a tube furnace under N 2 atmosphere. During the carbonization process, the nickel species aggregated together to form the core of nickel@carbon nanoparticles, and carbon formed the shell. At last, nickel nanoparticles were removed from the carbon framework by hydrochloric acid, obtaining HCSs with super-hydrophobicity and lipophilicity. The as-prepared HCSs exhibited excellent separation performance in oil-in-water emulsions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single-atom nanozyme-based electrochemical sensors have ultra-high sensitivity. • Electrochemical sensors for in-vivo small molecules detection are reviewed. • Electrochemical sensors are promising in health and food safety monitoring. • Practical application in health monitoring is discussed. • Optimization strategies to improve the sensing performance is proposed. Electrochemical sensors and biosensors play an important role in many fields, including biology, clinical trials, and food industry. For health and food safety monitoring, accurate and quantitative sensing is needed to ensure that there is no significantly negative impact on human health. It is difficult for traditional sensors to meet these requirements. In recent years, single-atom nanozymes (SANs) have been successfully used in electrochemical sensors due to their high electrochemical activity, good stability, excellent selectivity and high sensitivity. Here, we first summarize the detection principle of SAN-based electrochemical sensors. Then, we review the detection performances of small molecules on SAN-based electrochemical sensors, including H 2 O 2 , dopamine (DA), uric acid (UA), glucose, H 2 S, NO, and O 2. Subsequently, we put forward the optimization strategies to promote the development of SAN-based electrochemical sensors. Finally, the challenges and prospects of SAN-based sensors are proposed. [ABSTRACT FROM AUTHOR]

The introduction of certain structures or functional groups on benzothiazole and its derivatives containing a benzene ring and a thiazole ring can be used to construct benzothiazole fluorescent probes. Based on the mechanism of photoinduced electron transfer, excited-state intramolecular proton transfer (ESIPT), intramolecular charge transfer, aggregation-induced emission, the obtained fluorescent probes can specifically interact with the analyte, thereby changing their luminescence characteristics to achieve the detection of the analyte. Benzothiazole fluorescent probes can be applied to the detection of substances, the analysis of harmful substances and cell imaging. In this paper, the research situation of benzothiazole fluorescent probes in the past 5 years is reviewed, and it is mainly divided into metal ions, anions, small molecules and biological macromolecules according to the types of analytes. In the conclusion, the current challenges and further applications of benzothiazole fluorescent probes are analyzed. Application of detection and analysis of benzothiazole fluorescent probes. [ABSTRACT FROM AUTHOR]

In this paper, we propose an image encryption algorithm based on random walk and two hyperchaotic systems. The random walk method is adopted to scramble the position of pixels within a block. Furthermore, the permutation operation between blocks is presented to enhance the scramble effect. Thus, high correlation among pixels of original image is broken by permutation. Moreover, the chosen plaintext attack is used to test the anti-attack ability of the proposed algorithm. By analyzing experimental results and comparing with other image encryption algorithms, we show that the proposed algorithm has better performance and higher security. [ABSTRACT FROM AUTHOR]

A number of tropical cyclones (TCs) in the western North Pacific (WNP) pass through Luzon Strait (LS) into the South China Sea (SCS) from June to November every year. The monthly variability of the ratio of TC intensity change, Rtc, shows that majority of the LSTCs achieve their lifetime maximum intensity (LMI) over the northern SCS (WNP) during August-September (June-July and October-November). Furthermore, compared to August, LSTCs in September are more easily intensified, suggesting that atmospheric and/or oceanic environments over the northern SCS in September are more favorable for TC development. The monthly-averaged oceanic and atmospheric environmental factors, including sea surface temperature, upper-ocean warm layer depth, vertical wind shear, relative humidity and large-scale low-level vorticity, are compared. The comparison between August and September is mainly studied because of the higher LSTCs frequency in these 2 months. The intensification tendency of LSTCs in September is primarily attributed to the relative thick upper-ocean warm layer and weak vertical wind shear. The transition of East Asian summer monsoon to winter monsoon tends to provide more favorable environmental conditions in September than in August for TC intensification in the northern SCS. [ABSTRACT FROM AUTHOR]

It is well-known that Fe3+ impurities in the electrolyte can significantly promote the oxygen evolution reaction (OER) activity of Co-based and Ni-based electrocatalysts. However, it is not clear if they work for single-metal Fe-based catalysts. Here, we systematically investigate the influence of Fe3+ ions in the electrolyte on the OER activity of core-shell FeO x @C catalytic system. We find that the absorbed Fe3+ can induce the generation of surface oxygen vacancies and regulate the electronic structure of active sites, thus increasing the OER kinetics and decreasing the energy barrier. Combining with in-situ Raman and ex-situ X-ray photoelectron spectroscopy (XPS) analysis, we disclose that Fe4+ species is the active species for the OER and positively correlate the characteristic content of the high-valence Fe species and OER activity. Fe3+ impurities in the electrolyte can improve the OER activity of Fe-based catalysts, which can be oxidized into Fe4+ as the active species. [Display omitted] • FeO x @C-700 exhibits improved OER activity when dropping Fe3+ into the electrolyte. • Fe3+ impurities have synergistic effects with FeO x @C-700. • In-situ Raman and ex-situ XPS spectra reveal Fe4+ species during the OER. • Fe4+ favors the OER as the reactive species. [ABSTRACT FROM AUTHOR]

In this work, a novel circuit structure for second-harmonic multi-phase voltage controlled oscillator (MVCO) is presented. The proposed MVCO is composed of ( being an integer number and 2) identical inductor-capacitor () tank VCOs. In theory, this MVCO can provide 2 different phase sinusoidal signals. A six-phase VCO based on the proposed structure is designed in a TSMC 0.18um CMOS process. Simulation results show that at the supply voltage of 0.8V, the total power consumption of the six-phase VCO circuit is about 1mW, the oscillation frequency is tunable from 2.3GHz to 2.5GHz when the control voltage varies from 0V to 0.8V, and the phase noise is lower than 128dBc/Hz at 1MHz offset frequency. The proposed MVCO has lower phase noise, lower power consumption and more outputs than other related works in the literature. [ABSTRACT FROM AUTHOR]

Acetonitrile stacking is an online concentration method that is distinctive due to its inclusion of a high proportion of organic solvent in sample matrices. We previously designed a universal methodology for the combination of liquid-phase microextraction (LPME) and capillary electrophoresis (CE) using acetonitrile stacking and micellar electrokinetic chromatography (MEKC) mode, thereby achieving large-volume injection of the diluted LPME extractant and the online concentration. In this report, the methodology was extended to the analysis of highly substituted hydrophobic chlorophenols in wines using diethyl carbonate as the extractant. Additionally, the mechanism of acetonitrile stacking was studied. The results indicated that the combination of LPME and MEKC exhibited good analytical performance: with ∼40-fold concentration by LPME, a 20-cm (33% of the total length) sample plug injection of an eight-fold dilution of diethyl carbonate with the organic solvent-saline solution produced enrichments higher by a factor of 260–791. Limits of qualification ranged from 5.5 to 16.0 ng/mL. Acceptable reproducibilities of lower than 1.8% for migration time and 8.6% for peak areas were obtained. A dual stacking mechanism of acetonitrile stacking was revealed, involving transient isotachophoresis plus pH-junction stacking. The latter was associated with a pH shift induced by the presence of acetonitrile. The pseudo-stationary phase (Brij-35) played an important role in reducing the CE running time by weakening the isotachophoretic migration of the analyte ions following Cl − ions. The combination of acetonitrile stacking and nonionic micelle-based MEKC appears to be a perfect match for introducing water-immiscible LPME extractants into an aqueous CE system and can thus significantly expand the application of LPME-CE in green analytical chemistry. [ABSTRACT FROM AUTHOR]

The crystallization and melting behaviors of weakly segregated diblock copolymer (MPEG- b -PLLA) have been investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS). The microphase separation of MPEG- b -PLLA significantly influenced the crystallization behavior of PEG and the melting behavior of PLLA block, which formed during the two-step crystallization process. PLLA block crystallized from melt under various cooling rates ( R c, PLLA s) in the first step, and PEG sequentially crystallized in the second process as the temperature cooled from 60 °C to −70 °C at 10 °C/min. With R c, PLLA decreasing, PEG was more excluded out of the interlamellar regions of PLLA crystals, and concentrated into the interfibrillar regions, and formed the different microphase separation formed, which may attribute to the fractional crystallization and homogeneous nucleation. Then the melting peak of PLLA at lower temperature enhanced with the micro-domains of PEG growing, which could be ascribed to that PEG block could accelerate the melting of PLLA near these micro-domains. [ABSTRACT FROM AUTHOR]

Typhoon Nuri (2008) was 1 of approximately 120 typhoons in the past 60 years that passed through a narrow gap, the Luzon Strait, connecting the western North Pacific and the South China Sea (SCS). In total 70% of these storms, including Nuri, reached their maximum intensities over the warm waters east of Luzon and in the Kuroshio, then rapidly weakened in the SCS. Numerical experiments were conducted to understand the intensity change of Nuri. Westward across the Kuroshio in the Luzon Strait, the 26°C isotherm shallows rapidly by half. This and stronger mixing by wind-ocean resonance preferentially cooled sea surface temperature and weakened the typhoon in SCS. A positive-feedback mechanism is then described to explain the intensification of Nuri over the western North Pacific. [ABSTRACT FROM AUTHOR]

Generally, people tend to learn or recall pleasant experiences during positive feelings. Similarly, people tend to learn or recall unpleasant things during negative feelings. The research in psychological field has demonstrated that human memory is closely related to emotion. On one hand, emotion helps store the memory that possesses the same emotion valence, which is known as the mood congruency memory (MCM). On the other hand, memory stored in a certain emotional state will be associated easily when the same emotion occurs, which is called mood-dependent memory (MDM). Inspired by the mechanisms of MCM and MDM, a memristor-based circuit of emotion-affected associative memory neural network is proposed in this work. The designed circuit mainly contains MCM module and MDM module. The functions, such as learning, forgetting, variable learning rate, MCM effect, MDM effect, and time interval, are implemented by the circuit. The simulation results in PSPICE show that the proposed memristive circuit can learn and associate the memory based on emotional effects like humans. [ABSTRACT FROM AUTHOR]

Typhoon Nuri formed on 18 August 2008 in the western North Pacific east of the Philippines and traversed northwestward over the Kuroshio in the Luzon Strait where it intensified to a category 3 typhoon. The storm weakened as it passed over South China Sea (SCS) and made landfall in Hong Kong as a category 1 typhoon on 22 August. Despite the storm's modest strength, the change in typhoon Nuri's intensity was unique in that it strongly depended on the upper ocean. This study examines the ocean response to typhoon Nuri using the Princeton Ocean Model. An ocean state accounting for the sea-surface temperature (SST) and mesoscale eddy field prior to Nuri was constructed by assimilating satellite SST and altimetry data 12 days before the storm. The simulation then continued without further data assimilation, so that the ocean response to the strong wind can be used to understand processes. It is found that the SST cooling was biased to the right of the storm's track due to inertial currents that rotated in the same sense as the wind vector, as has previously been found in the literature. However, despite the comparable wind speeds while the storm was in western Pacific and SCS, the SST cooling was much more intense in SCS. The reason was because in SCS, the surface layer was thinner, the vorticity field of the Kuroshio was cyclonic, and moreover a combination of larger Coriolis frequency as the storm moved northward and the typhoon's slower translational speed produced a stronger resonance between wind and current, resulting in strong shears and entrainment of cool subsurface waters in the upper ocean. [ABSTRACT FROM AUTHOR]

Aiming at the problems of small key space and weak resistance to differential attacks in existing encryption algorithms, we proposed a chaotic digital image encryption scheme based on an optimized artificial fish swarm algorithm and DNA coding. First, the key is associated with the ordinary image pixel through the MD5 hash operation, and the hash value generated by the ordinary image is used as the initial value of the hyper-chaotic system to increase the sensitivity of the key. Next, the artificial fish school algorithm is used to scramble the positions of pixels in the block. In addition, scrambling operation between blocks is proposed to increase the scrambling effect. In the diffusion stage, operations are performed based on DNA encoding, obfuscation, and decoding technologies to obtain encrypted images. The research results show that the optimized artificial fish swarm algorithm has good convergence and can obtain the global optimal solution to the greatest extent. In addition, simulation experiments and security analysis show that compared with other encryption schemes, the scheme proposed in this paper has a larger key space and better resistance to differential attacks, indicating that the proposed algorithm has better encryption performance and higher security. [ABSTRACT FROM AUTHOR]

Herbivore-induced plant volatiles (HIPVs) are important compounds to prim neighboring undamaged plants; however, the mechanism for this priming process remains unclear. To reveal metabolic changes in plants exposed to HIPVs, metabolism of leaves and roots of Ammopiptanthus mongolicus seedlings exposed to HIPVs released from conspecific plants infested with larvae of Orgyia ericae were analyzed together with control and infested seedlings using nuclear magnetic resonance (NMR)-based metabolic technology and multi variate data analysis. Results presented showed that HIPVs exposure led to similar but specific metabolic changes compared with those induced by infestation in both leaves and roots. Furthermore, both HIPVs exposure and herbivore attack resulted in metabolic changes involving a series of primary and secondary metabolites in both leaves and roots. Taken together, these results suggested that priming of yet-damaged plants may be achieved by reconfiguring metabolic pathways in leaves and roots to make similar concentrations for all metabolites as those in seedlings infested. Therefore, we propose that improved readiness of defense induction of primed plants toward subsequent herbivore attack may be based on the similar metabolic profiling induced by HIPVs exposure as those caused by herbivore. [ABSTRACT FROM AUTHOR]

The crystallization and melting behaviorsof polylactide (PLA)homochiral polymer under the confinement of stereocomplex crystalliteswere studied in the linear and three-armed poly(d-lactide)/poly(l-lactide) (PDLA/PLLA and 3PDLA/3PLLA) solution casting blends.WAXD results showed that novel modified crystallites formed when PLAhomopolymer crystallized from the melting state. And the modifiedcrystallites formed in 3PDLA/3PLLA blends (M-A) were less stable thanthat formed in similar PDLA/PLLA blends (M-B) after specimens cooledat a specific rate. Although these modified crystallites differedfrom PLA α crystallites (M-C), both of them transformed intoα crystallites during heating. The transitions among differentcrystallites revealed the multiple melting behaviors in DSC measurement.The type of PLA homochiral crystallites and their contents mainlydepended on the D/L compositions, annealing conditions, molecularweights, and architectures of the polymers in the blends. The formationof these modified crystallites should be ascribed to the confinementof PLA stereocomplex and steric hindrance of polymers, and PLA homopolymercould not charge into lattice orderly during rapid crystallization. [ABSTRACT FROM AUTHOR]

The poly(d-lactide)/poly(l-lactide) (PDLA/PLLA) blends with low molecular weights were cast from solution. After heating to above the melting temperature, followed by cooling at various rates, DSC, WAXD and FTIR studies revealed that a mesomorphic phase developed in the PDLA/PLLA 90/10 and 80/20 (or 10/90 and 20/80) specimens when the temperature window spanned from 80 °C to 110 °C. The mesophase melted and reorganized into crystallites after the temperature increased to ∼130 °C. Although the formation and transition of the mesophase was observed at lower temperatures in partially crystallized specimens, the mesophase could exist steadily when the temperature did not exceed 100 °C. The content of the mesophase was proven to be strongly dependent on the cooling rate, the d/l weight ratio and the molecular weights in the blends. The formation of the mesophase could be explained by the fact that the crystallization of the PLA matrix was disturbed by the addition of small amount of enantiomeric PLA. [ABSTRACT FROM AUTHOR]

Abstract: In plants attacked by insects, metabolic changes can reflect the direct and indirect ability of those plants to resist infestation. However, the metabolic pathways involved in this process remain unclear, especially for plants which belong to ancient Tertiary relict taxon. To analyze the changes in metabolites and identify specific metabolic patterns induced by herbivorous and continuous mechanical wounding, the metabolism of Ammopiptanthus mongolicus seedlings damaged by Orgyia ericae Germar or continuous mechanical wounding were analyzed using nuclear magnetic resonance (NMR) combined with multivariate data analysis (MVDA). Principal component analysis (PCA) and orthogonal signal correction projections to latent structure discriminate analysis (OPLS-DA) showed that O. ericae feeding and mechanical wounding induced different changes in the metabolic profile of A. mongolicus both in local and systemic leaves. O. ericae feeding was associated with higher concentrations of many primary and secondary metabolites in local and systemic leaves than continuous mechanical wounding. In this way, the response of A. mongolicus to wounding was shown to be both specific to the metabolism, systemic, and to involve both primary and secondary metabolic pathways. [Copyright &y& Elsevier]

MXene quantum dots (MQDs) derived from MXene with photoluminescent properties have attracted considerable attention. Herein, nitrogen-doped MQDs (N-MQDs) were constructed by a solvothermal method using Ti 3 C 2 MXene as precursors and o-phenylenediamine (oPD) as the nitrogen source. The morphology, element composition and optical properties of N-MQDs were investigated by transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and spectroscopy etc. The obtained N-MQDs are dispersed quasi-spherical nanoparticles, mainly composed of carbon, oxygen and nitrogen, with yellow fluorescence at 580 nm and quantum yield of 5.42 %. In further, N-MQDs can detect Alizarin Red (ARS) based on inner filter effect (IFE) with linear range and detection limit of 0–80 μM and 1.21 μM, respectively. N-MQDs can detect ARS in real water samples, and were expected to have further applications in the fields of environmental monitoring and biosensing. Synthesis of N-MQDs and its detection of ARS. [Display omitted] • N-MQDs were synthesized by solvothermal method using Ti 3 C 2 MXenes and o-phenylenediamine as raw materials. • The obtained N-MQDs have yellow fluorescence at 580 nm and a large Stokes shift of 160 nm. • N-MQDs can be used for the detection of ARS based on inner filter effect. [ABSTRACT FROM AUTHOR]

Abstract: Poly(l-lactic acid) (PLLA) and Poly(d-lactic acid) (PDLA) with different optical purity were blended in an internal mixer and their crystallization behavior were investigated. Nearly complete stereocomplex crystallites could be obtained at specific condition between PLLA and PDLA. The melting temperature of stereocomplex was related with the optical purity of PLLA and PDLA, and also with the mixing temperature and time. When the mixing temperature was set dozens of degrees above the melting temperature of pure PLLA and PDLA at a weight ratio 1:1, the stereocomplex could be formed within a short period of time, and no homocrystallization or trace homocrystallization in some samples could be found. The possible mechanism of stereocomplex formation was achieved in this article and the shear force play an important role during the melt mixing process. [Copyright &y& Elsevier]

Stereocomplex poly(lactide)s (sc-PLAs) were obtainedfrom solutionblending of 3-armed poly(l-lactide) (3PLLA) and linear poly(d-lactide) (PDLA) and between enantiomeric 3PLAs. Differentialscanning calorimetry and wide-angle X-ray diffraction results indicatedthat racemic crystallites were preferentially produced in all thebinary blends. The melting temperature and fusion enthalpy of racemiccrystallites were remarkably different through varying the structure,constituent, and molecular weight of PLA. Through this investigation,higher melting temperatures were obtained in the middle molecularweight binary blends, and the highest melt temperature of racemiccrystallites reached to 246 °C, it was the highest reported valueuntil now. In similar molecular weight blends (or the linear PLA wassimilar to each branch of 3PLA enantiomers), with the compositionof 3PLA increasing, the phase separation molecular weight decreasedgradually (Mlinear/linear blends> Mlinear/3-armed blends> M3-armed/3-armed blends).The structuredistinction between 3PLA and linear PLA induced different thermalproperties and phase behaviors of the 3PLLA/PDLA and 3PLLA/3PDLA blends.The thermal properties of these mixtures and its variations providedbasic data for their industrial applications. [ABSTRACT FROM AUTHOR]

Crystallization behavior, structural development and morphology evolution of a series of poly (ethylene glycol)-poly( ε-caprolactone) diblock copolymers (PEG-b-PCL) were investigated via differential scanning calorimetry (DSC), X-ray diffraction (XRD) and atomic force microscopy (AFM). In these copolymers, both blocks were crystallizable and biocompatible. The mutual effects between the PEG and PCL blocks were significant, leading to the obvious block composition dependence of the crystallization behavior and morphology of the PEG-b-PCL copolymers. The relative block length determined which block crystallized first. The temperature-dependent XRD measurements confirmed which block crystallized first from the copolymer during the cooling procedure. Single crystals of the PCL and PEG homopolymers and the PEG-b-PCL copolymers were obtained and observed by AFM. The block (PCL or PEG) crystallized first would determine the crystal morphology. The block crystallized later acted as a solvent, which was advantageous to forming perfect single crystals of the whole block copolymers. [ABSTRACT FROM AUTHOR]

The unfolded protein response (UPR), which is activated when unfolded or misfolded proteins accumulate in the endoplasmic reticulum, has been implicated in the normal physiology of immune defense and in several human diseases, including diabetes, cancer, neurodegenerative disease, and inflammatory disease. In this study, we found that the nervous system controlled the activity of a noncanonical UPR pathway required for innate immunity in Caenorhabditis elegans. OCTR-1, a putative octopamine G protein-coupled catecholamine receptor (GPCR, G protein-coupled receptor), functioned in sensory neurons designated ASH and ASI to actively suppress innate immune responses by down-regulating the expression of noncanonical UPR genes pqn/abu in nonneuronal tissues. Our findings suggest a molecular mechanism by which the nervous system may sense inflammatory responses and respond by controlling stress-response pathways at the organismal level. [ABSTRACT FROM AUTHOR]

Abstract: Nectin-1 is an adhesion protein implicated in the organization of adherens junctions and tight junctions in epithelial cells. Previous studies in our laboratory demonstrated that nectin-1 accumulation was significantly decreased in Chlamydia trachomatis-infected HeLa cells. In the present study, Western blot analyses indicated that nectin-1 down-regulation was C. trachomatis concentration-dependent. The half-life of nectin-1 was also greatly diminished in C. trachomatis-infected cells compared to that observed in mock-infected cells, indicating that nectin-1 was likely down-regulated post-translationally. The chlamydia-secreted protease CPAF is known to degrade several important host proteins; CPAF expression within infected cells correlated with the time-dependent cleavage of nectin-1. Notably, CPAF proteolytic activity is inhibited by lactacystin but not by the proteosome inhibitor MG132. In vivo inhibition experiments demonstrated that nectin-1 down-regulation was blocked by lactacystin exposure. In contrast, MG132 had no effect. Finally, cell-free cleavage assays demonstrated that functional recombinant GST-CPAFwt protein degrades nectin-1. This degradation was blocked by lactacystin, as previously observed in vivo. Collectively, these results indicate that nectin-1 is degraded by CPAF in C. trachomatis-infected cells, a novel strategy that chlamydiae may use to aid their dissemination. [Copyright &y& Elsevier]

The article discusses a study which showed that herpes simplex virus co-infection-induced Chlamydia trachomatis persistence is not mediated by any known persistence inducer or anti-chlamydial pathway. A tissue-culture model of Chlamydia trachomatis/herpes simplex virus type-2 (HSV-2) co-infection indicates that viral co-infection stimulates the formation of persistent chlamydiae. Luminex assays indicate that interferon (IFN)-gamma, interferon-alpha and tumor necrosis factor (TNF)-alpha are not released from co-infected cells while semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) studies show that IFN-beta, IFN-gamma, indoleamine 2,3-dioxygenase, lymphotoxin-alpha and inducible persistence is not stimulated by any persistence-associated cytokine.

Crystallization behavior, structural development and morphology evolution in a series of diblock copolymers of poly(l-lactide)-block-poly(ethylene glycol) (PLLA-b-PEG) were investigated via differential scanning calorimetry, wide-angle X-ray diffraction, polarized optical microscopy and atomic force microscopy. In these copolymers, both blocks are crystallizable and biocompatible. It was interesting that these PLLA-b-PEG diblock copolymers could form spherulites with banded textures, which was undercooling dependent. Single crystals with an abundance of screw dislocations were also observed via AFM. Such results indicated that these ringed spherulites and single crystals were formed during the crystallization of the PLLA blocks. [Copyright &y& Elsevier]

Multi-year records of satellite remote sensing of sea surface salinity (SSS) provide an opportunity to investigate the climatological characteristics of the SSS response to tropical cyclones (TCs). In this study, the influence of TC winds, rainfall and preexisting ocean stratification on SSS evolution is examined with multiple satellite-based and in-situ data. Global storm-centered composites indicate that TCs act to initially freshen the ocean surface (due to precipitation), and subsequently salinify the surface, largely through vertical ocean processes (mixing and upwelling), although regional hydrography can lead to local departure from this behavior. On average, on the day a TC passes, a strong SSS decrease is observed. The fresh anomaly is subsequently replaced by a net surface salinification, which persists for weeks. This salinification is larger on the right (left)-hand side of the storm motion in the Northern (Southern) Hemisphere, consistent with the location of stronger turbulent mixing. The influence of TC intensity and translation speed on the ocean response is also examined. Despite having greater precipitation, stronger TCs tend to produce longer-lasting, stronger and deeper salinification especially on the right-hand side of the storm motion. Faster moving TCs are found to have slightly weaker freshening with larger area coverage during the passage, but comparable salinification after the passage. The ocean haline response in four basins with different climatological salinity stratification reveals a significant impact of vertical stratification on the salinity response during and after the passage of TCs. [ABSTRACT FROM AUTHOR]

The article presents a case of a female in her 40s who was rushed to a hospital due to progressive asymptomatic succulent erythematous-to-violaceous patch on the right side of her face to discuss hemifacial erythema as unusual manifestation of lupus erythematosus tumidus (LET). Based on skin biopsy, she has lymphocytic dermal infiltrate with abundant interstitial mucin deposition. She was eventually diagnosed with LET and was treated with prednisolone and hydroxychloroquine.

Abstract: A particular crystallization behavior of PLA stereocomplex was observed when the poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA) (50/50) was subjected to specific melting conditions. The effect of the holding temperature in the melt state of PLLA/PDLA samples on the nonisothermal melt crystallization process and on the structure have been investigated by means of DSC, and wide angle X-ray diffraction. In the moderate melting condition, residual ordered domains act as athermal nuclei and a single crystallization process via a predetermined nucleation mechanism was observed. The survived nuclei favor high temperature polymer crystallization, correspondingly, a high melting temperature (T m H ) of PLA stereocomplex, of 244.9°C with the fusion enthalpy 87.0J/g were obtained. Such a Tm result of PLA stereocomplex is much higher than that of the reported previously. [Copyright &y& Elsevier]

Solid-state carbon dots (SCDs) have been widely investigated by scholars owing to their stability, environmental friendliness, and their good optical properties. The current studies on carbon dots (CDs) are mainly focused on the solutions of CDs, while the researches on SCDs are relatively few in comparison. Nowadays, the fabrication and design of high-performance SCDs have attracted much interest. However, due to resonance energy transfer and π-π interactions, CDs undergo aggregation-induced quenching (ACQ) phenomena. This poses an obstacle to the acquisition of SCDs and affects their luminescence performance. Publications of the past 5 years are reviewed on how to suppress the ACQ phenomenon and improve the fluorescence and phosphorescence emission of CDs (Ref. 87) and about the mechanism of achieving the luminescence of SCDs. Then, the applications of SCDs in the fields of luminescent devices, anti-counterfeiting, and detection are outlined. The concluding section analyzes the current challenges faced by SCDs and provides an outlook. Mechanism of photoluminescence from solid state carbon dots [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is the key anode reaction of electrolytic water. To improve the slow OER kinetics, we synthesize nanoflower‐like Co−Fe‐Cr−Mo‐Mn high‐entropy spinel (HES) nanosheets on nickel foam (NF) by one‐step solvothermal method, which exhibit an overpotential (η10) of only 188 mV at 10 mA cm−2, much lower than bimetallic CoFeOx/NF (233 mV), trimetallic CoFeCrOx/NF (211 mV), and tetrametallic CoFeCrMoOx/NF (200 mV). The OER overpotential decreases with the increase of the number of metals, indicating that the formation of HES has a positive effect on the improvement of electrocatalytic performance, since the synergistic effect between different metals enhances the charge transfer rate and decreases reaction barrier. In‐situ Raman spectra demonstrate that the formation of γ‐NiOOH on the HES surface is a crucial active species for the OER. This work demonstrates a simple and efficient synthesis method to prepare nanoflower‐like high‐entropy electrocatalysts for efficient OER electrocatalysis. [ABSTRACT FROM AUTHOR]

Different logic circuits based on memristors have been extensively investigated. However, most of these circuits require accurate initialization. A self-learning logic circuit based on mermristors that can achieve various logic gates without initialization is proposed in this paper. Three functional blocks, including a sum block, a learning block, and a compare block, are elaborately designed in the proposed logic circuit. Programmable switches in the sum and compare blocks enable the circuit to perform various logic gates, such as Boolean, IMPLY, and random logical combinations. In these various logical operations, the learning block can automatically obtain different memristance states. The aforementioned logic operations can easily be extended to multi-fan-in logic and logical cascade operations. Circuit designs of an encoder and decoder are considered as application examples. Finally, PSpice simulation results of the logic circuits and extended applications are provided. Simulation results indicate that the proposed circuit can effectively perform different logic operations and exhibits excellent robustness to circuit device variations. [ABSTRACT FROM AUTHOR]

High-entropy materials (HEMs) have potential application value in electrocatalytic water splitting because of their unique alloy design concept and significant mixed entropy effect. Here, we synthesize a high-entropy Ni–Fe–Cr–Mn–Co (oxy)hydroxide on nickel foam (NF) by a solvothermal method. The flower-like structure of FeNiCrMnCoOOH/NF can provide abundant active sites, thus improving the oxygen evolution reaction (OER) activity. In 1 M KOH, the FeNiCrMnCoOOH/NF shows an ultra-low overpotential (η10) of 201 mV for the OER, superior to FeNiCrMnAlOOH/NF, FeNiCrMnCuOOH/NF, FeNiCrMnMoOOH/NF, and FeNiCrMnCeOOH/NF. In addition, it exhibits a low η10 of 223 mV in 0.5 M NaCl + 1 M KOH and excellent stability. Electrochemical impedance spectroscopy measurements indicate that the synergistic effect between multiple metals accelerates charge transfer, while in situ Raman measurements reveal that NiOOH is a key active species for the OER. This work is of great significance for the construction of high-entropy (oxy)hydroxides for seawater electrolysis. [ABSTRACT FROM AUTHOR]

Poly(lactide) stereocomplex (PLA SC) and poly(ethylene glycol) (PEG) crystallites were obtained in MPEG- b -PLLA/MPEG- b -PDLA (linear blend, 1/1) and 4PEG- b -PLLA/4PEG- b -PDLA (4-arm blend, 1/1) by solution-casting method. The molecular weights of PLLA and PDLA ( M n, PLA ) were similar in all the linear and 4-arm blends. Only PLA SC and PEG crystallites were observed, and PLA homocrystallites were absent in all blends. The different M n, PLA and chain architectures did not alter the crystalline structures of PLA SC and PEG, but greatly influenced their melting temperatures and crystallinities. As the average M n, PLA per arm of linear and 4-arm blends were similar, the melting temperatures and crystallinities of PLA SC and PEG in 4-arm blends were always lower than those of linear blends, which could be ascribed to the huge steric hindrance of 4-arm structures. This investigation on PEG- b -PLLA/PEG- b -PDLA blends with various structures could provide basic data for the applications of PLA stereocomplex. [ABSTRACT FROM AUTHOR]

Since the Lorenz chaotic system was discovered in 1963, the construction of chaotic systems with complex dynamics has been a research hotspot in the field of chaos. Recently, memristive Hopfield neural networks (MHNNs) offer great potential in the design of complex, chaotic systems because of their special network structures, hyperbolic tangent activation function, and memory property. Many chaotic systems based on MHNNs have been proposed and exhibit various complex dynamical behaviors, including hyperchaos, coexisting attractors, multistability, extreme multistability, multi-scroll attractors, multi-structure attractors, and initial-offset coexisting behaviors. A comprehensive review of the MHNN-based chaotic systems has become an urgent requirement. In this review, we first briefly introduce the basic knowledge of the Hopfiled neural network, memristor, and chaotic dynamics. Then, different modeling methods of the MHNN-based chaotic systems are analyzed and discussed. Concurrently, the pioneering works and some recent important papers related to MHNN-based chaotic systems are reviewed in detail. Finally, we survey the progress of MHNN-based chaotic systems for application in various scenarios. Some open problems and visions for the future in this field are presented. We attempt to provide a reference and a resource for both chaos researchers and those outside the field who hope to apply chaotic systems in a particular application. [ABSTRACT FROM AUTHOR]

Chronic lymphedema predisposes to develop malignant cutaneous tumors, including angiosarcoma, Kaposi's sarcoma and B-cell lymphoma. T-cell malignancy has rarely been associated with chronic lymph stasis. Here, we report a case of primary cutaneous anaplastic large cell lymphoma ( pcALCL) with lymphatic spread associated with chronic lymphedema. The patient is a 56-year-old man who received orchiectomy and right inguinal lymphadenectomy for malignant seminoma 10 years ago, which led to prominent lymphedema of the right leg. He developed extensive skin nodules on the lymphedematous area for 3 months. Histopathology findings confirmed a diagnosis of pcALCL, which is a subtype of cutaneous T-cell lymphoma characterized by the presence of CD30+ T cells. Intralymphatic infiltration of malignant cells is prominent. The pathogenesis of intralymphatic cutaneous anaplastic large cell lymphoma is largely unknown. Our case suggests that chronic lymphedema resulted in persistent CD4+ T-cell inflammation, which then may contribute to the development of pcALCL. [ABSTRACT FROM AUTHOR]

The analog circuit design of the memristive neural network (MNN), which can automatically perform the online learning algorithm, is an open question. In this article, a memristive self-learning neuron circuit for implementing the online least mean square (LMS) algorithm is designed. Extending on the designed neuron circuit, the circuit implementation of the monolayer and multilayer neural network is proposed. The proposed neural network can automatically converge the output to the set target according to the input. The application-level validations of the circuits are done using pattern recognition and license plate detection. The performances of the designed MNN circuits and the effect of memristive variation are analyzed through PSPICE simulations. The learning accuracy of the proposed circuit for license plate detection can reach 93%. Circuit simulation results reveal that the proposed MNN circuits can accelerate the training speed and have the tolerance to the variations of the memristor. [ABSTRACT FROM AUTHOR]

Emotional intelligence plays an important role in artificial intelligence. The brain circuitry of emotion mainly includes the prefrontal cortex, the amygdala, hippocampus and et al. Many brain emotional learning (BEL) models were proposed in recent years, the existing BEL models failed to consider the contextual information in practical applications, and do not discuss the corresponding circuit implementation. In this article, a context-dependent emotional learning network (CD-ELN) and its memristive circuit implementation are introduced. The added context-dependent module is used to process the contextual information, which makes the network context dependent when receiving the same input signals. For circuit implementation, the memristive circuit design mainly contains the amygdala module and orbitofrontal cortex module, which imitates the emotion learning process in the brain. Besides, a multi-input multioutput memristive circuit of the context-dependent emotional network is applied to multitask classification. PSPICE simulation results verified the adaptability and flexibility of the CD-ELN. [ABSTRACT FROM AUTHOR]

This letter describes a low-voltage low-power (LV-LP) 2.4-GHz mixer for Industrial, Scientific and Medical (ISM) band wireless applications. The approach is based on a two-stage amplifier, and the Gilbert switch stage is inserted between the two amplifier stages. The proposed amplifier-based mixer delivers a remarkable conversion gain of 13 dB with a local oscillator (LO) power of 7 dBm, while consuming only 1.05-mW DC power from a 0.8-V supply voltage. The input-referred third-order intercept point (IIP3) of the mixer is 3.82 dBm, and the chip area is only 0.429 mm2. The results indicate that this mixer is suitable for the low-voltage low-power applications. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Linear and four-armed poly( l-lactide)- block-poly( d-lactide) (PLLA- b-PDLA) block copolymers are synthesized by ring-opening polymerization of d-lactide on the end hydroxyl of linear and four-armed PLLA prepolymers. DSC results indicate that the melting temperature and melting enthalpies of poly (lactide) stereocomplex in the copolymers are obviously lower than corresponding linear and four-armed PLLA/PDLA blends. Compared with the four-armed PLLA- b-PDLA copolymer, the similar linear PLLA- b-PDLA shows higher melting temperature (212.3 °C) and larger melting enthalpy (70.6 J g−1). After these copolymers blend with additional neat PLAs, DSC, and WAXD results show that the stereocomplex formation between free PLA molecular chain and enantiomeric PLA block is the major stereocomplex formation. In the linear copolymer/linear PLA blends, the stereocomplex crystallites (sc) as well as homochiral crystallites (hc) form in the copolymer/PLA cast films. However, in the four-armed copolymer/linear PLA blends, both sc and hc develop in the four-armed PLLA- b-PDLA/PDLA specimen, which means that the stereocomplexation mainly forms between free PDLA molecule and the inside PLLA block, and the outside PDLA block could form some microcrystallites. Although the melting enthalpies of stereocomplexes in the blends are smaller than that of neat copolymers, only two-thirds of the molecular chains participate in the stereocomplex formation, and the crystallization efficiency strengthens. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1560-1567 [ABSTRACT FROM AUTHOR]

Abstract: In this article, two types of poly (d-lactide)-b-poly (ethylene glycol)-b-poly (d-lactide) (PDLA-b-PEG-b-PDLA) were added into PLLA matrix by solution casting method. The obtained films were characterized by wide-angle X-ray diffractomery (WAXD), differential scanning calorimetry (DSC), tensile testing and thermal gravimetric analyzer (TGA). Results indicated that the heat resistance of these blends could be improved when the amount of copolymer exceeded 30 wt%, because the high melting point stereocomplex was preferentially formed at that addition amount, whenever from solutions or from melt. Both the tensile strength and elongation at break of the blends were enhanced when 30 wt% copolymer was added, which were partly caused by the synergistic effects of stereocomplexation between enantiomeric PLAs and plasticization of PEG blocks. The blends showed higher thermal stability than neat PLLA at temperature above 370 °C. These results showed that the toughness and heat resistance of PLLA were improved, which made the application of PLA probable. [Copyright &y& Elsevier]

Highlights: [•] The MVCO could provide six or eight different phase sinusoidal signals. [•] The frequency tuning range of the six-phase MVCO is from 788.5MHz to 2.506GHz. [•] The frequency tuning range of the eight-phase MVCO is from 558.9MHz to 1.512GHz. [Copyright &y& Elsevier]

The block copolymers of poly( d -lactide)- b -poly(butylene succinate)- b -poly( d -lactide) (PDLA- b -PBS- b -PDLA) were added into PLLA matrix to enhance the toughness of PLLA by solution casting method. The properties of the films were investigated by wide angle X-ray diffractometry (WAXD), differential scanning calorimetry (DSC) and tensile testing. The WAXD and DSC results showed that the stereocomplex was the major crystalline when the amount of copolymer addition exceeded 30 wt%. The blending samples with high mechanical strength and toughness could be obtained only when certain amount of PDLA- b -PBS- b -PDLA copolymers were added. [ABSTRACT FROM AUTHOR]