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Tree tensor network states (TTNS) decompose the system wavefunction to the product of low-rank tensors based on the tree topology, serving as the foundation of the multi-layer multi-configuration time-dependent Hartree method. In this work, we present an algorithm that automatically constructs the optimal and exact tree tensor network operators (TTNO) for any sum-of-product symbolic quantum operator. The construction is based on the minimum vertex cover of a bipartite graph. With the optimal TTNO, we simulate open quantum systems, such as spin relaxation dynamics in the spin-boson model and charge transport in molecular junctions. In these simulations, the environment is treated as discrete modes and its wavefunction is evolved on equal footing with the system. We employ the Cole–Davidson spectral density to model the glassy phonon environment and incorporate temperature effects via thermo-field dynamics. Our results show that the computational cost scales linearly with the number of discretized modes, demonstrating the efficiency of our approach. [ABSTRACT FROM AUTHOR]

The artificial nociceptor is a device that simulates the biological nociception system, which has a wide range of applications in the fields of medicine, rehabilitation, and robotics. Multimodal nociceptors can respond to diverse stimuli, including visual, mechanical, and thermal, and so on, and then convert them into neural signals for processing by the brain. Herein, a back‐gate optoelectronic transistor based on 2D InSe/MoS2 heterostructure is demonstrated. By employing energy band alignment of the heterojunction, the device exhibits high sensitivity (106) and high responsivity (330 AW−1) to harmful UV irradiation, which can be exploited to emulate the key features of nociceptors, including "threshold," "relaxation," "no adaptation," and "sensitization." Moreover, the device can be operated in a two‐terminal mode, memristive characteristics are obtained through applying source–drain voltages. Then, artificial nociceptive behaviors responding to external electrical pulses have been successfully emulated. Finally, the modulation of nociceptive sensitivity can be achieved through the controlling gate bias, which fully demonstrates the potential of our device for the application of biomimetic multimodal artificial nociceptors in future neuromorphic sensory system. [ABSTRACT FROM AUTHOR]

Molecular weight (MW) of organics was one of the important factors influencing membrane fouling propensity. This study identified critical foulants of reverse osmosis (RO) membranes in reclaimed water by MW fractionation. MW > 10 kDa component was identified as the critical fouling contributor (CFC) in secondary effluent (SE), which accounted for only 13 ± 5% of dissolved organic carbon (DOC) but contributed to 86 ± 11% of flux decline. Throughout 12-month monitoring, SE and MW > 10 kDa component showed a similar fouling variation tendency: apparently higher fouling potential in winter and lower in summer, while MW < 10 kDa component presented minor fouling changes. Morphology of membrane fouled by CFC characterized a smooth and thick foulant layer on membrane surface. CFC was mainly composed of proteins and polysaccharides, and a protein-polysaccharide-protein "sandwich" fouling layer structure was preferentially formed on membrane surface. extended Derjaguin–Landau-Verwey–Overbeek (xDLVO) analysis demonstrated that strong attractive interactions between CFC and membrane surface dominated the fouling process. Furthermore, computational fluid dynamics (CFD) simulation revealed strong filtration resistance of CFC, confirming its significant fouling potential. Dual effects including attractive interactions and advantageous ridge-and-valley surface appearance accounted for the significant fouling propensity of MW > 10 kDa component and glean valuable insights into RO fouling mechanisms of reclaimed water in practical application. [ABSTRACT FROM AUTHOR]

Cynanchum otophyllum Schneid is an important medicinal plant in China. In this paper, the chloroplast genome of C. otophyllum was sequenced based on high-throughput technology, and the chloroplast genome structure characteristics and phylogenetic relationship of C. otophyllum were analyzed. The results showed the complete plastome genome size of C. otophyllumis 160,874bp, including one small single copy (SSC, 19,851bp) and one large single copy (LSC, 92,009bp) regions isolated by a pair of inverted repeat regions (IRs, 24,507bp). The whole plastome genome including 84 protein encoding genes, 8 rRNA and 37 tRNA. Based on the phylogenetic topologies, C. otophyllum shows close association with additional Gomphocarpus and Asclepias genus. This study contributes to an enhanced understanding of the genetic information of C. otophyllum and provides a theoretical basis for the development of molecular markers and phylogeographic of the species, as well as for constructing the phylogenetic tree of Asclepiadaceae. [ABSTRACT FROM AUTHOR]

There is no measurable and evaluable index system for cloud-network convergence that provides guidance and reference for the subsequent construction and development of cloud-network convergence. It is a big project to select and evaluate the indexes of cloud-network convergence, which requires suitable index selection and index evaluation schemes. Based on analytic hierarchy process (AHP) and entropy weight method, this paper proposes an improved AHP (i-AHP) index selection scheme and index evaluation scheme leveraging the years of experts' experience, the geometric mean and the least square method. The improved weighted least square method (WLSM) is finally proved to be more stable for index evaluation scheme by adding abnormal data. In addition, the index weight obtained by the index evaluation scheme with WLSM are provided as a reference for the future development of cloud-network convergence. The simulation results show that the proposed scheme is superior to the existing index evaluation scheme and can avoid the weight deviation caused by the disturbance and fluctuation of abnormal data. [ABSTRACT FROM AUTHOR]

Fuel cladding tubes are devices used in reactors to encapsulate fuel clots and transmit heat to coolants. However, zirconium alloy materials which are widely used in the fuel cladding pipe of pressurized water reactors have noticeable safety risks in resisting design basis accidents. Therefore, it is very important to improve the corrosion resistance of fuel envelope tubes to high-temperature water vapor oxidation. High-entropy alloys are considered to be a potential protective coating material for cladding tubes. In this study, AlCrNbSiTi high-entropy alloy (HEA) coatings were prepared by magnetron sputtering at different bias voltages. The effect of bias on coating morphologies, structure, mechanical properties, and resistance to high-temperature water vapor corrosion were studied. Experimental results showed that the bias significantly affects the coating surface roughness. In terms of mechanical properties, the sample at 50 V bias exhibited maximum hardness and elastic modulus of 18.2 GPa and 232.4 GPa, respectively. The highest adhesive force of the coating to the substrate of 36 N was obtained at 100 V bias. The optimum water vapor corrosion resistance of the AlCrNbSiTi HEA coating was achieved at 50 V bias, in which sample-point corrosion was the main corrosion failure mechanism. [ABSTRACT FROM AUTHOR]

Water disinfection is conventionally achieved by oxidation or irradiation, which is often associated with a high carbon footprint and the formation of toxic byproducts. Here, we describe a nano-structured material that is highly effective at killing bacteria in water through a hydrodynamic mechanism. The material consists of carbon-coated, sharp Cu(OH)2 nanowires grown on a copper foam substrate. We show that mild water flow (e.g. driven from a storage tank) can efficiently tear up bacteria through a high dispersion force between the nanotip surface and the cell envelope. Bacterial cell rupture is due to tearing of the cell envelope rather than collisions. This mechanism produces rapid inactivation of bacteria in water, and achieved complete disinfection in a 30-day field test. Our approach exploits fluidic energy and does not require additional energy supply, thus offering an efficient and low-cost system that could potentially be incorporated in water treatment processes in wastewater facilities and rural communities. Common methods for water disinfection involve oxidation or irradiation, and are often associated with a high carbon footprint and formation of toxic byproducts. Here, the authors describe a nano-structured material that is highly effective at killing bacteria in water through a hydrodynamic mechanism driven by mild water flow, in the absence of additional energy supply. [ABSTRACT FROM AUTHOR]

The concentration of biomarkers in sweat can be used to evaluate human health, making efficient sweat sensing a focus of research. While flow channel design is often used to detect sweat velocity, it is rarely incorporated into the sensing of biomarkers, limiting the richness of sensing results. In this study, we report a time sequential sensing scheme for uric acid in sweat through a sequential design of Tesla valve channels. Graphene electrodes for detecting uric acid and directional Tesla valve flow channels were fabricated using laser engraving technology to realize time sequential sensing. The performance of the channels was verified through simulation. The time sequential detection of uric acid concentration in sweat can help researchers improve the establishment of human health management systems through flexible wearable devices. [ABSTRACT FROM AUTHOR]

Given rapid global urban development, increases to impervious surfaces, urban population growth, building construction, and energy consumption result in the urban heat island (UHI) phenomenon. However, the spatial extent of UHIs is not clearly mapped in many UHI studies based on a remote sensing approach. Therefore, we developed a method to extract the spatial extent of the UHI during the period from 2000 to 2021 in Nanjing, China, and explored the impact of urban two- and three-dimensional expansion on UHI spatial extent and UHI intensity. After cropland effects (i.e., bare soil) were eliminated, our proposed method combines the Getis-Ord-Gi* and the standard deviation of the normalized difference vegetation index (NDVI STD) to extract the UHI area from Landsat 5 and Landsat 8 images using land surface temperature (LST) spatial autocorrelation characteristics and the seasonal variation of vegetation. Our results show the following: (1) Bare farmland has a large influence on the extraction results of UHI—combined with the seasonal variation characteristics of NDVI STD, the impact of bare soil on UHI extraction was highly reduced, strongly improving the accuracy of UHI extraction. (2) The dynamics of the UHI area are consistent with the changes in the built-up area in Nanjing at both spatial and temporal scales, but with the increase of the urban green ratio, the UHI area of mature urban areas trends to decrease due to the cooling effect of green space. (3) The accumulation of population and GDP promote the vertical expansion of urban buildings. When the two-dimensional expansion of the city reaches saturation, the UHI intensity is primarily affected by three-dimensional urban expansion. [ABSTRACT FROM AUTHOR]

Triboelectrification for contacts between three types of materials—metals, polymers, and semiconductors—are investigated. The results show that triboelectrification is a charge exchange process between the surfaces of two friction materials, and its output is the synergetic effects of the electrostatic induction (ESI) and dynamic junction modulation (DJM). There are four current/voltage peaks in output of triboelectrification: two of them are attributed to the ESI effect and determined by the surface state densities and electron affinity difference of the materials, while the other two are associated with the DJM effect and determined by the charging exchange between the surface states and the depletion region. However, metals and polymers have no‐modulation of depletion region due to their high conductivity and insulating nature, respectively, thus only two peaks induced by the ESI effect are observable no matter what types of metals and polymers are in pair for contacting. Semiconductors have a depletion region, there will be two more output current/voltage peaks induced by the junction modulation when a semiconductor is in contact with any type of materials. The observations reveal a universal triboelectrification mechanism for contacts between materials, and provide an intuitive guidance for the development of high‐performance triboelectric nanogenerators. [ABSTRACT FROM AUTHOR]

The stochastic differential equation is a powerful tool for describing the dynamics of a dissipative system in which noise characterizes the influence of the environment. For the Ornstein-Uhlenbeck noise, both the formula of differentiation and the hierarchy approach provide efficient numerical simulations, with the stochastic differential equation transformed into a set of coupled, linear ordinary differential equations. We show that while these two deterministic schemes result in different sets of equations, they can be regarded as two representations of an underlying linear-dynamics. Moreover, by manipulating the involved Ornstein-Uhlenbeck noise, we propose a unified algorithm that may reduce to the hierarchy approach or the formula of differentiation in different limits. We further analyze the numerical performance of this algorithm and find that the hierarchy approach appears to be more efficient for our numerical model studies. [ABSTRACT FROM AUTHOR]

Accurate and efficient estimation of forest volume or biomass is critical for carbon cycles, forest management, and the timber industry. Individual tree detection and segmentation (ITDS) is the first and key step to ensure the accurate extraction of detailed forest structure parameters from LiDAR (light detection and ranging). However, ITDS is still a challenge to achieve using UAV-LiDAR (LiDAR from Unmanned Aerial Vehicles) in broadleaved forests due to the irregular and overlapped canopies. We developed an efficient and accurate ITDS framework for broadleaved forests based on UAV-LiDAR point clouds. It involves ITD (individual tree detection) from point clouds taken during the leaf-off season, initial ITS (individual tree segmentation) based on the seed points from ITD, and improvement of initial ITS through a refining process. The results indicate that this new proposed strategy efficiently provides accurate results for ITDS. We show the following: (1) point-cloud-based ITD methods, especially the Mean Shift, perform better for seed point selection than CHM-based (Canopy Height Model) ITD methods on the point clouds from leaf-off seasons; (2) seed points significantly improved the accuracy and efficiency of ITS algorithms; (3) the refining process using DBSCAN (density-based spatial clustering of applications with noise) and kNN (k-Nearest Neighbor classifier) classification significantly reduced edge errors in ITS results. Our study developed a novel ITDS strategy for UAV-LiDAR point clouds that demonstrates proficiency in dense deciduous broadleaved forests, and this proposed ITDS framework could be applied to single-phase point clouds instead of the multi-temporal LiDAR data in the future if the point clouds have detailed tree trunk points. [ABSTRACT FROM AUTHOR]

As the backup power supply of power plants and substations, valve-regulated lead-acid (VRLA) batteries are the last safety guarantee for the safe and reliable operation of power systems, and the batteries' status of health (SOH) directly affects the stability and safety of power system equipment. In recent years, serious safety accidents have often occurred due to aging and failure of VRLA batteries, so it is urgent to accurately evaluate the health status of batteries. Accurate estimation of battery SOH is conducive to real-time monitoring of single-battery health information, providing a reliable guarantee for fault diagnosis and improving the overall life and economic performance of the battery pack. In this paper, first, the floating charging operation characteristics and aging failure mechanism of a VRLA battery are summarized. Then, the definition and estimation methods of battery SOH are reviewed, including an experimental method, model method, data-driven method and fusion method. The advantages and disadvantages of various methods and their application conditions are analyzed. Finally, for a future big data power system backup power application scenario, the existing problems and development prospects of battery health state estimation are summarized and prospected. [ABSTRACT FROM AUTHOR]

At present, the common protection technology of power-transmission and transformation equipment is mainly coating protection and hot-dip zinc protection. However, due to the low adhesion of epoxy zinc-rich coating, and the poor compatibility with top paint, environmental pollution, complex processing, high energy consumption and other defects of the hot-dip zinc process, its development is limited. In view of the above deficiencies, new anti-corrosion coating materials and processes were investigated in this study. Zinc coatings and Al-Zn coatings were prepared on the C45 steel matrix by hot-spraying and cold-spraying processes. The macro appearance, micromorphology and phase composition analysis of the coatings were evaluated. The adhesion of the coating to the substrate after the salt-spray test was tested. The results showed that the hot dip zinc coating and hot spray zinc coating had obvious cracking after the salt-spray test. The surface structure of cold-sprayed Al-Zn coating was relatively dense after the salt-spray test. The critical load of the cold-sprayed Al-Zn coating after the salt-spray test was higher than that of the other two coatings. The corrosion resistance to salt spray of cold-sprayed Al-Zn coating was demonstrated to be better than the hot-dip zinc coating, and thus has great application prospects. [ABSTRACT FROM AUTHOR]

In view of the substation fire early warning using a single information sensor monitoring, it is easy to make mistakes and omissions. Taking the cable in substation as the research object, a multi-information fusion fire prediction model based on back propagation neural network (BPNN) and fuzzy set theory is proposed. Firstly, the BPNN model is trained by using the existing data. Secondly, the artificial fish swarm algorithm (AFSA) is used to optimize the BPNN, which speeds up convergence speed of the model and improves the accuracy of prediction. The fuzzy set theory is applied to fuse the predicted fire probability to obtain the optimal fire prevention and control decision. Finally, the fire protection measures are taken according to the fire decision. The experimental show that the average absolute errors of no fire, smoldering and open fire decreased by 26.06%, 38.5% and 43.13% respectively. The model has higher prediction accuracy, can reasonably output different levels of fire alarm signals, establish substation fire warning and prevention and control system, and provide reference for future substation fire and other disasters warning and prevention and control. [ABSTRACT FROM AUTHOR]

Ascorbic acid (also called Vitamin C, VC) strengthens the function of Tets families and directly increases DNA demethylation level to affect myogenic differentiation. However, the precise regulatory mechanism of DNA methylation in chicken myogenesis remains unclear. Results of present study showed that the mRNA expression of MyoD significantly decreased and MyoG and MyHC increased in myoblasts treated with 5 μM 5-azacytidine (5-AZA) and 5 μM VC (p < 0.05). Results also indicated the formation of myotubes was induced by 5-AZA or VC, but this effect was attenuated after knockdown of Tet2. In addition, the protein expression of TET2, DESMIN and MyHC was remarkable increased by the addition of 5-AZA or VC, and the upregulation was inhibited after knockdown of Tet2 (p < 0.05). DNA dot blot and immunofluorescence staining results suggested that the level of 5hmC was significantly increased when treated with 5-AZA or VC, even by Tet2 knockdown (p < 0.05). Moreover, 5-AZA and VC reduced the level of dimethylation of lysine 9 (H3K9me2) and trimethylation of lysine 27 of histone 3 (H3K27me3), and this inhibitory effect was eliminated after Tet2 knockdown (p < 0.05). These data indicated that Tet2 knockdown antagonized the increased levels of 5hmC and H3K27me3 induced by 5-AZA and VC, and eventually reduced myotube formation by modulating the expression of genes involved in myogenic differentiation. This study provides insights that epigenetic regulators play essential roles in mediating the myogenic program of chicken myoblasts. [ABSTRACT FROM AUTHOR]

Microelectrode array (MEA) is a powerful tool for recording electrophysiological signals and studying the electrophysiological features of nerve, retina, and cardiomyocytes. Stretchable electrodes can form conformal contact with dynamic biological tissues/organs (e.g. heart) to enhance the coupling efficiency in electrophysiological measurements. However, MEAs based on conventional materials require serpentine interconnections to enable stretchability. A large number of serpentine interconnects take up spaces and hinder the improvement of spatial resolution. Here, we introduce a multilayer design strategy that yields a stretchable MEA with spatial density of 7.3 sites mmâˆ'2 and biaxial stretchability of 30%. The serpentine interconnects of each layer overlap vertically to reduce the area of the wires used for connection. In vitro validation in phosphate buffered saline and ex vivo test on perfused mouse heart show a 100% yield rate of the multilayer stretchable MEA, with capabilities in spatiotemporal mapping of electrophysiological signals at high spatial resolution. [ABSTRACT FROM AUTHOR]

To solve the problem of the single-phase ground fault and occurrence of electrical fires due to the residual current in substation AC power systems, a residual current intelligent sensing technology is proposed based on ensemble empirical modal decomposition (EEMD), sample entropy (SE) reconstruction, and fire warning technology using a beetle antennae search algorithm. First, through the residual current monitoring device to collect residual current information, EEMD and SE reconstruction for arc-earth fault diagnosis and an analysis of the differences in the current characteristics of each line after reconstruction are used to determine the fault line. Second, residual current, temperature, and operating voltage as input parameters and fire probability are the output parameters. The input–output relationship is established by a back-propagation neural network (BPNN) and optimized by the beetle antennae search (BAS) algorithm to speed up the convergence and improve the prediction accuracy to establish a substation fire warning scheme. Through simulation experiments, this paper proposes the residual current as a monitoring object method can effectively diagnose ground faults and accurately predict the probability of fire occurrence to ensure the safe and stable operation of substations. [ABSTRACT FROM AUTHOR]

Chongming Island, the third largest island in China, has experienced dramatic shoreline changes due to erosion, river deposits, and human activities. While previous studies have shown the capacity of Landsat series images to extract shoreline dynamics, the spatial variation of shoreline dynamics and their corresponding driving factors remain unclear. Therefore, we established a method to monitor the shoreline dynamics of Chongming Island from 1984 to 2020 and to evaluate the driving factors of shoreline changes using a novel approach to Landsat image analysis. The method, based on the LISA (local indicator of spatial autocorrelation) concept, automatically extracted the shoreline from Landsat imagery. The results show that the LISA method, based on the SWIR1 band, has a high capacity for shoreline extraction in Chongming Island. By distinguishing the responses of the eastern and northern shorelines to upstream sediment loads and comprehensively analyzing the driving factors of eastern and northern dynamics, we found that: (i) although upstream sediment loads decreased dramatically, the shoreline of Chongming Island is still expanding due to human activities (i.e., reclamation and an estuary project) and sediment re-suspension from near-shore or cross-shore currents; (ii) the expansion of Chongming Island was initially due to the dynamics at the eastern shoreline, but the expansion of the eastern shoreline slowed after 2008 as upstream sedimentation slowed, less construction of cofferdams took place, and the Qingcaosha Reservoir was constructed; (iii) the northern shoreline of Chongming Island expanded rapidly after 1999, due to the merger of Xinlongsha, Xincunsha, and Chongming Island, and the transport of coastal and offshore sediments by hydrodynamic processes; and (iv) the main driving factors of eastern shoreline movement on Chongming Island are cofferdam reclamation and coastal engineering, and the changes at the northern shoreline are mainly affected by reclamation projects, offshore sediment supplies, and upstream sediment inflow. The results of this study provide theoretical fundamentals for land reclamation and future urban planning for Chongming Island. [ABSTRACT FROM AUTHOR]

Nanocrystalline tin (IV) oxide (SnO2) as an electron‐transport layer (ETL) has unique advantages in realizing highly efficient and stable planar perovskite solar cells (PSCs), especially showing great potential in the low‐temperature preparation of large‐area flexible carbon‐based PSCs (C‐PSCs). However, the high trap density on the surface of SnO2 tends to cause serious nonradiative recombination losses, thereby reducing photoelectric performance. In this work, an inexpensive and easily obtained polymer poly(ethylene‐co‐vinyl acetate) (Eva) is used as a interfacial modifier to reduce the interfacial defects and nonradiative recombination losses at the SnO2/perovskite interface. As a result, the crystallinity and conductivity of the perovskite layer are significantly increased, and the charge lifetime and stability are effectively improved. The Eva modified SnO2‐based C‐PSCs obtain an optimal power conversion efficiency (PCE) of 12.29%, which is 25.7% higher than that of 9.78% for the unmodified C‐PSCs. Furthermore, the unencapsulated devices maintain 88.6% and 91.9% of the initial PCE over 1 month in ambient air for the unmodified and Eva‐modified C‐PSCs, respectively. The study provides valuable experience for the development of highly efficient and stable C‐PSCs using common polymers for interface modification engineering. [ABSTRACT FROM AUTHOR]

Nanocrystalline tin (IV) oxide (SnO2) as an electron‐transport layer (ETL) has unique advantages in realizing highly efficient and stable planar perovskite solar cells (PSCs), especially showing great potential in the low‐temperature preparation of large‐area flexible carbon‐based PSCs (C‐PSCs). However, the high trap density on the surface of SnO2 tends to cause serious nonradiative recombination losses, thereby reducing photoelectric performance. In this work, an inexpensive and easily obtained polymer poly(ethylene‐co‐vinyl acetate) (Eva) is used as a interfacial modifier to reduce the interfacial defects and nonradiative recombination losses at the SnO2/perovskite interface. As a result, the crystallinity and conductivity of the perovskite layer are significantly increased, and the charge lifetime and stability are effectively improved. The Eva modified SnO2‐based C‐PSCs obtain an optimal power conversion efficiency (PCE) of 12.29%, which is 25.7% higher than that of 9.78% for the unmodified C‐PSCs. Furthermore, the unencapsulated devices maintain 88.6% and 91.9% of the initial PCE over 1 month in ambient air for the unmodified and Eva‐modified C‐PSCs, respectively. The study provides valuable experience for the development of highly efficient and stable C‐PSCs using common polymers for interface modification engineering. [ABSTRACT FROM AUTHOR]

Chicken blastoderm cells (cBCs) obtained from stage X (EG&K) embryos are easily available materials for the study of cell development. However, cBCs are not widely used because they are hard to maintain in long-term culture in vitro. To solve this problem, ascorbic acid (AA; also known as vitamin C (VC)) and all-trans retinoic acid (ATRA) were added into basic culture medium to promote cell growth. Results suggested that cultured cBCs possessed strongly proliferative activity and maintained their pluripotency on the support of chicken embryonic fibroblast (CEF) feeder. Moreover, when VC or/and ATRA was added, the number and area of cBC colonies increased significantly compared with the control group. The expression of pluripotency genes (Sox2 and Nanog) and cell cycle–regulated genes (CCND1 and CDK6) was upregulated obviously. Furthermore, results showed that 5hmC levels in VC and RA groups increased significantly by DNA dot blot and immunofluorescence staining. These results provide strong evidence that VC and ATRA induced DNA demethylation and enhanced 5hmC level. The level of H3K27me3 was raised, while the level of H3K9me2 was reduced by addition of VC and ATRA. Finally, the expression of Tet1 and Dnmt3b was upregulated remarkably. Therefore, these results indicated that VC and ATRA enhanced DNA demethylation and then promoted cBC survival and proliferation in vitro. [ABSTRACT FROM AUTHOR]

Small extracellular vesicles (sEVs) play a key role in intercellular communication. Cargo molecules carried by sEVs may affect the phenotype and function of recipient cells. Epithelial cancer cell‐derived sEVs, particularly those enriched in CD151 or tetraspanin8 (TSPAN8) and associated integrins, promote tumour progression. The mechanism of binding and modulation of sEVs to recipient cells remains elusive. Here, we used genetically engineered breast cancer cells to derive TSPAN8‐enriched sEVs and evaluated the impact of TSPAN8 on target cell membrane's diffusion and transport properties. The single‐particle tracking technique showed that TSPAN8 significantly promoted sEV binding via confined diffusion. Functional assays indicated that the transgenic TSPAN8‐sEV cargo increased cancer cell motility and epithelial‐mesenchymal transition (EMT). In vivo, transgenic TSPAN8‐sEV promoted uptake of sEVs in the liver, lung, and spleen. We concluded that TSPAN8 encourages the sEV‐target cell interaction via forced confined diffusion and significantly increases cell motility. Therefore, TSPAN8‐sEV may serve as an important direct or indirect therapeutic target. [ABSTRACT FROM AUTHOR]

The rapid development of electronic skins has allowed novel multifunctional human–machine interaction interfaces, especially in motion interaction sensors. Although motion sensing is widely used in advanced flexible electronic devices through the integration of single sensing units, the number of electrodes has increased with the increase in integration by the square multiple. This paper presents a self‐powered electronic skin based on the Archimedes spiral structure design, which can detect the multi‐directional movement of the slider without external energy supply. As the rotation angle of the Archimedes spiral increases from 2π to 4π, the maximum resolvable movement direction of the device increases from 24 to 280, and the number of electrodes is kept at 4. Through the exploration of the principle of triboelectricity, the inherent electronegativity of the triboelectric materials is used as the basis for signal discrimination, which not only increases the reliability of the device, but also solves the problem of energy supply during device operation. A reduced number of electrodes and its battery‐free nature enables this electronic skin to be easily integrated into portable electronic devices, such as laptops, smart phones, healthcare devices, etc. [ABSTRACT FROM AUTHOR]

In this paper, we report a magnetic and conductive textile made from a mixture of NdFeB microparticles, multi-walled carbon nanotubes, and polydimethylsiloxane. The textile can (i) shield 99.8% of electromagnetic signals ranging from 30 MHz to 3 GHz, thereby protecting people from damage caused by the electromagnetic radiation, (ii) be hydrophobic and fire retardant, making it a possible choice for raincoat and fire protection clothing, and (iii) convert mechanical energy into electricity through both electromagnetic induction and triboelectrification. The textile creates many opportunities in the fields of multifunctional protective equipment and energy harvesting. [ABSTRACT FROM AUTHOR]

High smelting temperature of phosphate ore and low activity of the slag lead to energy-extensive consumption and large solid waste generation in the yellow phosphorus industry. Micronutrient-bearing cosolvents were added to the reduction smelting process of phosphate ore to reduce the smelting temperature and increase the activity of slag in the current work. Thermodynamic analysis demonstrated that B2O3 and K2O as cosolvents can decrease the melting temperature, promote the liquid phase formation and reduce the slag viscosity. In addition, cosolvents had no unfavorable effect on the reduction volatilization of phosphate ore, and the volatilization ratio of phosphorus was > 97 wt.% at 1550°C for 1 h. In this case, the value of slag was enhanced with the addition of cosolvents, and the activation ratios of micronutrients were > 90%. Resultantly, no solid waste was generated since the activated slag can be regarded as a favorable ingredient for the crop fertilizer. [ABSTRACT FROM AUTHOR]

Whether chemical bonding can regulate the excited‐state and optoelectronic properties of donor–acceptor dyads has been largely elusive. In this work, we used electronic structure and nonadiabatic dynamics methods to explore the excited‐state properties of covalently bonded zinc phthalocyanine (ZnPc)‐fullerene (C60) dyads with a 6–6 (or 5–6) bonding configuration in which ZnPc is bonded to two carbon atoms shared by the two hexagonal rings (or a pentagonal and a hexagonal ring) in C60. In both cases, the locally excited (LE) states on ZnPc are spectroscopically bright. However, their different chemical bonding differentiates the electronic interactions between ZnPc and C60. In the 5–6 bonding configuration, the LE states on ZnPc are much higher in energy than the LE states on C60. Thus, the excitation energy transfer from ZnPc to C60 is thermodynamically favorable. On the other hand, in the 6–6 bonding configuration, such a process is inhibited because the LE states on ZnPc are the lowest ones. More detailed mechanisms are elucidated from nonadiabatic dynamics simulations. In the 6–6 bonding configuration, no excitation energy transfer was observed. In contrast, in the 5–6 bonding configuration, several LE and charge‐transfer (CT) excitons were shown to participate in the energy‐transfer process. Further analysis reveals that the photoinduced energy transfer is mediated by a CT exciton, such that electron‐ and hole‐transfer processes take place in a concerted but asynchronous manner in the excitation energy transfer. It is also found that high‐level electronic structure methods including exciton effects are indispensable to accurately describe photoinduced energy‐ and electron‐transfer processes. Furthermore, this work opens up new avenues for regulating the excited‐state properties of molecular donor–acceptor dyads by means of chemical bonding. [ABSTRACT FROM AUTHOR]

Inosine is an important RNA modification, furthermore RNA oxidation has gained interest due, in part, to its potential role in the development/progression of disease as well as on its impact on RNA structure and function. In this report we established the base pairing abilities of purine nucleobases G, I, A, as well as their corresponding, 8‐oxo‐7,8‐dihydropurine (common products of oxidation at the C8‐position of purines), and 8‐bromopurine (as probes to explore conformational changes), derivatives, namely 8‐oxoG, 8‐oxoI, 8‐oxoA, 8‐BrG, and 8‐BrI. Dodecamers of RNA were obtained using standard phosphoramidite chemistry via solid‐phase synthesis, and used as models to establish the impact that each of these nucleobases have on the thermal stability of duplexes, when base pairing to canonical and noncanonical nucleobases. Thermal stabilities were obtained from thermal denaturation transition (Tm) measurements, via circular dichroism (CD). The results were then rationalized using models of base pairs between two monomers, via density functional theory (DFT), that allowed us to better understand potential contributions from H‐bonding patterns arising from distinct conformations. Overall, some of the important results indicate that: (a) an anti‐I:syn‐A base pair provides thermal stability, due to the absence of the exocyclic amine; (b) 8‐oxoG base pairs like U, and does not induce destabilization within the duplex when compared to the pyrimidine ring; (c) a U:G wobble‐pair is only stabilized by G; and (d) 8‐oxoA displays an inherited base pairing promiscuity in this sequence context. Gaining a better understanding of how this oxidatively generated lesions potentially base pair with other nucleobases will be useful to predict various biological outcomes, as well as in the design of biomaterials and/or nucleotide derivatives with biological potential. [ABSTRACT FROM AUTHOR]

Stretchable electronics have great importance for applications of wearable devices and electronic skin. Balancing and improving mechanical stretchability and electronic performance are the key challenges that restrict further development of stretchable electronics. In order to achieve stretchable electronics, it is crucial to choose appropriate substrates, among which PDMS is the most commonly used polymer due to its easy fabrication and low cost. In this paper, we propose a novel strategy and fabricate localized modulus-controlled PDMS for both 2D and 3D stretchable electronics. Based on a secondary cross-link effect, the modulus of cured PDMS can be enhanced and controlled by spin-coating different masses of curing agent. Using a laser-cut PI mask, the modulus-enhanced region can be defined by users. Through this simple method, the functional conductive thin-film materials (gold/Ag nanowires/reduced graphene oxide) can be well protected when the structural layer is stretched and the 'barrel effect' of a multi-material film (where different material films possess different stretchability) on one piece of substrate can also be solved. Besides this, compared with uniform PDMS, different 3D buckling structures can be formed on locally modified PDMS as a substrate by a pre-stretching and releasing process, illustrating a new way to control the 3D buckling structure. [ABSTRACT FROM AUTHOR]

The multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) theory within second quantization representation of the Fock space, a novel numerically exact methodology to treat many-body quantum dynamics for systems containing identical particles, is applied to study the effect of vibrational motion on electron transport in a generic model for single-molecule junctions. The results demonstrate the importance of electronic-vibrational coupling for the transport characteristics. For situations where the energy of the bridge state is located close to the Fermi energy, the simulations show the time-dependent formation of a polaron state that results in a pronounced suppression of the current corresponding to the phenomenon of phonon blockade. We show that this phenomenon cannot be explained solely by the polaron shift of the energy but requires methods that incorporate the dynamical effect of the vibrations on the transport. The accurate results obtained with the ML-MCTDH in this parameter regime are compared to results of nonequilibrium Green's function theory. [ABSTRACT FROM AUTHOR]

The multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method is applied to simulate the quantum dynamics and thermal rate constant of the Azzouz-Borgis model of proton transfer in a polar solvent. To this end, the original atomistic potential is mapped to a system-bath model. Employing the flux correlation function formalism and importance sampling techniques, accurate quantum mechanical rate constants are obtained, which provide a benchmark for evaluating approximate approaches to study the quantum dynamics of condensed-phase chemical reactions. Furthermore, the validity of the mapping procedure is discussed based on the comparison of the classical dynamics of the original atomistic Azzouz-Borgis model and the mapped system-bath model. [ABSTRACT FROM AUTHOR]

An analog of the Meir–Wingreen formula for the steady-state heat current through a model molecular junction is derived. The expression relates the heat current to correlation functions of operators acting only on the degrees of freedom of the molecular junction. As a result, the macroscopic heat reservoirs are not treated explicitly. This allows one to exploit methods based on a reduced description of the dynamics of a relatively small part of the overall system to evaluate the heat current through a molecular junction. The derived expression is applied to calculate the steady-state heat current in the weak coupling limit, where the Redfield theory is used to describe the reduced dynamics of the molecular junction. The results are compared with those of previously developed approximate and numerically exact methods. [ABSTRACT FROM AUTHOR]

A generalized master equation approach is developed to describe electron transfer (ET) dynamics in the presence of mode mixing. Results from this approximate approach are compared to the numerically exact simulations using the multilayer multiconfiguration time-dependent Hartree theory. The generalized master equation approach is found to work well for nonadiabatic resonant ET. Depending on the specific situation, it is found that the introduction of mode mixing may either increase or decrease the ET time scale. The master equation fails in the adiabatic ET regime, where the introduction of mode mixing may lead to electron trapping. From both the approximate theory and the numerically exact simulation it is shown how neglecting mode mixing in practical calculations may lead to inaccurate predictions of the ET dynamics. [ABSTRACT FROM AUTHOR]

We investigate the influence of strong femtosecond optical pulses on the ultrafast dynamics of molecular systems. The study is based on a series of generic molecular models of increasing complexity, which incorporate multiple and mutually coupled electronic states, electronic-vibrational interaction, and vibrational relaxation. The influence of vibrational relaxation is treated using multilevel Redfield theory. Comparisons to benchmark results of the multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method demonstrate the validity of the field-free implementation of Redfield theory employed in this work for weak system-bath interaction. The calculated electronic population and vibrational wave-packet dynamics demonstrate the intricate interplay of strong-field excitation, laser-induced Rabi oscillations, electronic interaction, vibronic coupling, and dissipation. In particular, we show that the interaction with a strong laser pulse may result in pronounced coherent vibrational motion in a dissipative system, even for laser pulses that are longer than the vibrational period. Furthermore, vibrational relaxation in combination with strong laser pulse excitation can lead to revivals of the electronic population after the excitation pulse is over. [ABSTRACT FROM AUTHOR]

The capability of multilevel Redfield theory to describe ultrafast photoinduced electron-transfer reactions is investigated. Adopting a standard model of photoinduced electron transfer in a condensed-phase environment, we consider electron-transfer reactions in the normal and inverted regimes, as well as for different values of the electron-transfer parameters, such as reorganization energy, electronic coupling, and temperature. Based on the comparison with numerically exact reference results, obtained using the self-consistent hybrid method, we discuss in some detail the advantages and shortcomings of two different versions of Redfield theory, which employ the time-dependent and stationary Redfield tensor, respectively. The results of the study demonstrate that multilevel Redfield theory, if applied in the appropriate parameter regime, is well suited to describe the ultrafast coherent dynamics of photoinduced electron-transfer reactions. [ABSTRACT FROM AUTHOR]

A multilayer (ML) formulation of the multiconfiguration time-dependent Hartree (MCTDH) theory is presented. In this new approach, the single-particle (SP) functions in the original MCTDH method are further expressed employing a time-dependent multiconfigurational expansion. The Dirac-Frenkel variational principle is then applied to optimally determine the equations of motion. Following this strategy, the SP groups are built in several layers, where each top layer SP can contain many more Cartesian degrees of freedom than in the previous formulation of the MCTDH method. As a result, the ML-MCTDH method has the capability of treating substantially more physical degrees of freedom than the original MCTDH method, and thus significantly enhances the ability of carrying out quantum dynamical simulations for complex molecular systems. The efficiency of the new formulation is demonstrated by converged quantum dynamical simulations for systems with a few hundred to a thousand degrees of freedom. [ABSTRACT FROM AUTHOR]

A classical trajectory simulation performed on the PES1(Br) analytic potential energy surface is used to study the atomic-level dynamics of the Cl[sup -]+CH[sub 3]Br→ClCH[sub 3] + Br[sup -]S[sub N]2 nucleophilic substitution reaction. At low reactant relative translational energies E[sub rel] of less than 5 kcal/mol, the reaction is dominated by an indirect mechanism in which the Cl[sup -] ··· CH[sub 3]Br complex or both the Cl[sup -] ··· CH[sub 3]Br and ClCH[sub 3] ··· Br[sup -] complexes are formed. For E[sub rel] > 10 kcal/mol a direct reaction mechanism dominates without the formation of either complex. For E[sub rel] of 5-10 kcal/mol there is a minimum in the S[sub N]2 rate constant which, for a CH[sub 3]Br vibrational/rotational temperature T[sub υr] of 300 K, is ∼400 times smaller than the rate at E[sub rel] of 0.1 kcal/mol. The dependence of the trajectory S[sub N]2 rate constants on E[sub rel], T[sub υ], and T[sub r] is significantly different than the prediction of a statistical theoretical model. For E[sub rel] ≤ 10 kcal/mol there is a much more pronounced decrease in the trajectory S[sub N]2 rate constant as E[sub rel] is increased as compared to the statistical model, which arises from the inadequacy of the ion-molecule capture component of the statistical model. As E[sub rel] is increased the trajectory Cl[sup -] + CH[sub 3]Br association rate constant becomes much smaller than that predicted by the ion-molecule capture model. Increasing the CH[sub 3]Br rotational temperature from 300 to 600 K decreases the trajectory S[sub N]2 rate constant more than the prediction of the statistical model. At low E[sub rel], where the reaction occurs by an indirect mechanism, the product energy is preferentially partitioned to CH[sub 3]Cl vibration. For the direct mechanism, which dominates at high E[sub rel], the majority of the energy is partitioned to product relative... [ABSTRACT FROM AUTHOR]

The semiclassical (SC) initial value representation (IVR) provides a way for including quantum effects into classical molecular dynamics simulations. Implementation of the SC-IVR to the thermal rate constant calculation, based on the reactive flux correlation function formalism, has two major obstacles: (1) the SC integrand may be highly oscillatory with respect to the initial phase space variables; and (2) matrix elements of the Boltzmannized flux operator, which are crucial in generating the initial (or final) distribution for the SC trajectories, are generally not available in analytic forms. In this paper, we present practical ways of overcoming these two barriers for the SC calculation of thermal rate constants. For the first problem, we show that use of a symmetric flux–flux correlation function, together with the generalized Filinov transformation technique, can significantly smooth the corresponding SC integrand and make the calculation practical for quite large systems. For the second problem, we propose a general method for evaluating matrix elements of the Boltzmannized flux operator “on-the-fly,” based on the combination of the imaginary-time path integral technique with the Metropolis random walk algorithm. Using these approaches, it is shown that thermal rate constants can be obtained for systems with more than 100 degrees of freedom, as well as for reactions in the deep tunneling regimes where quantum effects are significant. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

An efficient method, the self-consistent hybrid method, is proposed for accurately simulating time-dependent quantum dynamics in complex systems. The method is based on an iterative convergence procedure for a dynamical hybrid approach. In this approach, the overall system is first partitioned into a “core” and a “reservoir” (an initial guess). The former is treated via an accurate quantum mechanical method, namely, the time-dependent multiconfiguration self-consistent field or multiconfiguration time-dependent Hartree approach, and the latter is treated via a more approximate method, e.g., classical mechanics, semiclassical initial value representations, quantum perturbation theories, etc. Next, the number of “core” degrees of freedom, as well as other variational parameters, is systematically increased to achieve numerical convergence for the overall quantum dynamics. The method is applied to two examples of quantum dissipative dynamics in the condensed phase: the spin-boson problem and the electronic resonance decay in the presence of a vibrational bath. It is demonstrated that the method provides a practical way of obtaining accurate quantum dynamical results for complex systems. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The self-consistent hybrid approach [H. Wang, M. Thoss, and W. H. Miller, J. Chem. Phys. 115, 2979 (2001), preceding paper] is applied to the spin-boson problem with Debye spectral density as a model for electron-transfer reactions in a solvent exhibiting Debye dielectric relaxation. The population dynamics of the donor and acceptor states in this system is studied for a broad range of parameters, including the adiabatic (slow bath), nonadiabatic (fast bath), as well as the intermediate regime. Based on illustrative examples we discuss the transition from damped coherent dynamics to purely incoherent decay. Using the numerically exact results of the self-consistent hybrid approach as a benchmark, several approximate theories that have been widely used to describe the dynamics in the spin-boson model are tested: the noninteracting blip approximation, the Bloch–Redfield theory, the Smoluchowski-equation treatment of the reaction coordinate (Zusman equations), and the classical path approach (Ehrenfest model). The parameter range where the different methods are applicable are discussed in some detail. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We present a self-cleaning organic solar cells (OSCs) with a light-trapping structure by introducing a groove-shaped micro/nanostructured haze thin films (GHFs). The GHF with periods larger than wavelengths of incident light can broaden the effective optical paths and promote the diffused lights, while keeping high (low) total transmission (reflectance) properties. When laminated GHF on top of the light-in side of OSCs, the power conversion efficiency of OSCs is improved more than 10%. Simultaneously, the superhydrophobic GHF composed of the groove structure allows the droplets to successfully remove dust particles from the polydimethylsiloxane (PDMS) surface during the roll-off process of the drop. Under 10 cycles of dust contamination and cleaning treatment, OSCs with GHF can still guarantee an initial efficiency of 84% (76%), showing great potentials of OSCs in practical applications. [ABSTRACT FROM AUTHOR]

Multi-fluorescent imaging of cell cycle progression is essential for the study of cell proliferation in vitro and in vivo. However, there remain challenges, particularly to image cell cycle progression in living cell with available imaging techniques due to lacking the suitable probe. Here, we design a triple fluorescent sensors system making the cell cycle progression visible. Multi-fluorescent sensor shows the proliferating or proliferated cells with different colors. We thus generate the construct and adenovirus to probe cell cycle progression in living cell lines and primary cardiomyocytes. Furthermore, we create the knock-in transgenic mouse to monitor cell cycle progression in vivo. Together, the system can be applied to investigate cell proliferation or cell cycle progression in living cells and animals. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effectiveness of Bioelectrical Impedance Spectroscopy (BIS) in order to rapidly distinguish malignant vs benign breast masses. Methods: A total of 622 breast masses from 489 patients were collected from January 2015 to June 2017. Every specimen was evaluated by a breast tissue bioimpedance analyzer (MScan1.0B) followed by morphological examination by pathologists. The results from BIS were compared with the morphological results from pathology (as a gold standard). The specificity and sensitivity of BIS were evaluated and the consistency test was performed. Results: Compared with the pathology standard, BIS had good sensitivity (92.4%), specificity (96.0%), false positive rate (3.96%), and false negative rate (7.58%). The positive likelihood ratio, negative likelihood ratio, positive predictive value, and negative predictive values of BIS were 23.36, 0.0789, 73.49%, 99.07%, respectively. The kappa value of BIS was 0.794 ± 0.038 in the consistency test. Conclusion: Compared with the pathology standard, the BIS is an effective, convenient, and economical detection method to quickly differentiate benign and malignant breast masses with high accuracy. It may serve as a potential supplement of intraoperative pathological examinations. [ABSTRACT FROM AUTHOR]

Studies thermal rate constant using flux-flux autocorrelation functions with absorbing boundary conditions. Treatment of total angular momentum; Employment of the body-fixed axis frame; Comparisons with previous exact and approximate theoretical results.

A previous trajectory study of the dissociation of Cl-...CH3Cl complexes formed by Cl-+CH3Cl association is further analyzed to determine (1) the relationship between classical and quantum Rice–Ramsperger–Kassel–Marcus (RRKM) rate constants for Cl-...CH3Cl→Cl-+CH3Cl dissociation; (2) the importance of anharmonicity in calculating the RRKM dissociation rate constant; (3) the role of angular momentum in interpreting the trajectory distribution N(t)/N(0) of Cl-...CH3Cl complexes versus time; and (4) the pressure-dependent collision-averaged rate constant k(ω,E) for Cl-...CH3Cl dissociation. It is found that only the low-frequency intermolecular modes of Cl-...CH3Cl are initially excited by Cl-+CH3Cl association. Classical and quantum RRKM rate constants for dissociation of this intermolecular complex are in excellent agreement. Anharmonicity lowers the rate constant by a factor of 4–8 from its harmonic value. The dissociation rate for the long-time tail of the trajectory N(t)/N(0) distribution is much smaller than predicted by a RRKM model, which accurately treats angular momentum. It is suggested that the long-lived trajectories may arise from motion on vague tori. The trajectory collision-averaged rate constant k(ω,E) is in agreement with an experimental study at 300 K. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]