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The intrinsic carbon defects including pentagons, vacancies and sp3-hybridized carbon have recently been proposed as efficient reactive sites for oxygen reduction reaction (ORR). Nevertheless, it is still a great challenge to controllably introduce the intrinsic defects into carbon materials. Herein, a universal defect-engineering method via vaporized salt is reported to modify the N-doped carbon surface with abundant sp3-hybridized carbon defects. At an elevated temperature, the vaporized sodium chloride is found to selectively modulate the surface structure of carbon material. The obtained carbon-based electrocatalyst delivers an outstanding electrocatalytic ORR property with a half-wave potential (E1/2) of 0.85 V vs. RHE and an excellent performance in zinc air battery (ZAB) test. The analysis of components and structures of surface elements via XANES and XPS reveals that the increasing sp3-hybridized carbon defects, induced by the vaporized-salt modification, are responsible for the enhancement of ORR performance. The theoretical calculations further suggest the sp3 component hybridizes with original sp2 carbon, forming efficient sp2/sp3 hybridized carbon sites towards ORR. Additionally, other halide salts are proved to have the similar effect on promoting ORR activity and this method can expand to other carbon-based materials, suggesting its universality and significance in synthesis of defect-rich carbon-based materials.

Quantifying the influences of land use/cover (LULC) change on hydrological processes is important for rational utilization of water resources. The objective of this study was to evaluate the impacts of spatiotemporal LULC change on hydrological components in a typical agricultural area located in the North China Plain at both basin and sub-basin scales. LULC change was quantified, and the Soil and Water Assessment Tool was optimized using parameters associated with LULC conditions. We concluded that the urban and forest areas increased by 25.57 and 10.56%, with the cropland area decreased by 36.76%. About half of the surface runoff (SURQ) in the basin was generated from the urban area, with the SURQ increased significantly in the upstream and downstream of the basin where overlapped with urbanized areas. The proportions of evapotranspiration generated by cropland and forest areas increased slightly (0.89 and 0.55%, respectively), especially in sub-basins where the conversion of cropland to forest was obvious. Urban, forest, and cropland were the main types that generated water yield (WYLD). The proportion of WYLD generated on the urban area increased by 9.55% and decreased in other areas, which may be related to the combined effects of urbanization and forest reduction. Highlights The SWAT model was used under different scenarios for a typical agricultural area, North China Plain.; The influences of land use/cover change on key hydrological components were analyzed at both basin and sub-basin scales.; Urbanization and reforestation will affect changes in hydrological components.

Developing an efficient catalyst for hydrogen (H2) generation from hydrolysis of ammonia borane (AB) to significantly improve the activity for the hydrogen generation from AB is important for its practical application. Herein, we report a novel hybrid nanostructure composed of uniformly dispersed Co@Co2P core-shell nanoparticles (NPs) embedded in N-doped carbon nanotube polyhedron (Co@Co2P/N–CNP) through a carbonization-phosphidation strategy derived from ZIF-67. Benefiting from the electronic effect of P doping, high dispersibility and strong interfacial interaction between Co@Co2P and N-CNTs, the Co@Co2P/N–CNP catalyst exhibits excellent catalytic performance towards the hydrolysis of AB for hydrogen generation, affording a high TOF value of 18.4 mol H2 mol metal−1 min−1 at the first cycle. This work provides a promising lead for the design of efficient heterogeneous catalysts towards convenient H2 generation from hydrogen-rich substrates in the close future.

The isolation of specific and sensitive circulating tumor cells (CTCs) is significant for applying them in cancer diagnosis and monitoring. In this work, dual aptamer-modified poly(lactic-co-glycolic acid) (PLGA) nanofiber-based microfluidic devices were fabricated to achieve the highly efficient capture and specific release of epithelial and mesenchymal CTCs of ovarian cancer. Dual aptamer targeting epithelial cell adhesion molecules (EpCAM) and N-cadherin proteins to improve the capture sensitivity, bovine serum albumin (BSA) to guarantee the capture purity and the nanofibers to increase the capture efficiency via synchronously and effectively capturing the epithelial and mesenchymal CTCs with good capture specificity and sensitivity from blood samples were used. We used the target cells including the ovarian cancer A2780 cells (N-cadherin-high, EpCAM-low) and OVCAR-3 cells (EpCAM-high, N-cadherin-low) to test the devices, which exhibited good capture efficiency (91% for A2780 cells, 89% for OVCAR-3 cells), release efficiency (95% for A2780 cells, 88% for OVCAR-3 cells), and sensitivity for rare cells (92% for A2780 cells, 88% for OVCAR-3 cells). Finally, the clinical blood samples of ovarian cancer patients were detected by the PLGA nanofiber-based microfluidic device, and 1 to 13 CTCs were successfully confirmed to be captured with the help of immunofluorescence staining identification. The results exhibited that the dual aptamer-modified PLGA nanofiber-based microfluidic device used as a tool for CTC capture has the potential for clinical application to guide the diagnosis, treatment, and prognosis of ovarian cancer patients.

Internet of things (IoT) in smart city consists of a diversity of public utility and vertical industry services with extremely different performance requirements. As a key technology of 5G networks, network slicing (NS) is featured to provide distinct virtual networks and differentiated QoS guarantees in a shared infrastructure. Therefore, it becomes necessary to employ intelligent NS management for IoT in smart city. This work proposes a machine learning (ML) driven automatic NS framework which can intelligently scale slice according to network state. The resource preservation and slicing implementation scheme is given to trade off robustness and resource efficiency. Finally, the present study provides preliminary results via simulation and experimentation to justify the effectiveness and efficiency of the presented design.

Circulating tumor cells (CTCs) are an important part of liquid biopsy as they represent a potentially rich source of information for cancer diagnosis, monitoring, prognosis, and treatment guidance. It has been proved that the nanotopography interaction between cells and the surface of CTC detection platforms can significantly improve the capture efficiency of CTCs, whereas many mature nanostructure substrates have been developed based on chemistry materials. In this work, a natural biointerface with unique biological properties is fabricated for efficient isolation and nondestructive release of CTCs from blood samples using the cancer cell membranes. The cell membrane interfaces are proved to have a good antiadhesion property for nonspecific cells because of their own electronegativity. A natural surface nanostructure is provided by the cancer cell membrane to nicely match with the surface nanotopography of CTCs. Bovine serum albumin (BSA) as a linker and DNA aptamer against the epithelial cell adhesion molecule (EpCAM) as a specific affinity molecule are then introduced onto the cell membrane interfaces to achieve the highly efficient and specific capture of CTCs. Finally, the captured target cells can be intactly released from the substrate using the complementary DNA sequence with controlling the incubation time. This study provides a smart strategy in the development of a natural biological interface for the isolation and release of CTCs with high purity.

One of the key challenges with atomic catalysts (single, double, and triple atom catalysts) is the relatively low loading of active materials, resulting in the low mass or volume activity of catalysts, which hinders their rapid development in the field of catalysis. Herein, using density functional theory (DFT), we explore a series of atomic catalysts with heterostructured substrate, graphdiyne and graphene (GDY/Gra), for the nitrogen reduction reaction (NRR). The theoretical mass loading of active metal atoms can exceed 35.0 wt% in the triple atom catalyst (TAC), which could be reached through the optimal substrate and suitable precursors in experiments. Among the designed atomic catalysts, Fe3-GDY/Gra with a theoretical mass loading of 35.8 wt% shows outstanding catalytic activity for the electrocatalytic NRR with a potential of −0.26 V vs. the reversible hydrogen electrode (RHE). Moreover, the proposed TACs show better catalytic activity for the NRR than single atom catalysts (SACs) and double atom catalysts (DACs) due to the unique properties of M3 (M = Mn, Fe, Co, and Ni) active sites, which provide more electrons for activating N2, but also have a weak adsorption to more easily release products. These findings provide a new strategy for designing atomic catalysts with high loading, high stability, and high activity.

Edge computing can be widely used in unmanned aerial vehicle (UAV) inspection, field operation control, power consumption information collection and other businesses in the power Internet of Things scene. Edge computing offloads functions such as data processing and applications to network edge nodes near the terminals to provide low-latency services and ensure service quality. However, with the explosive growth of business terminals, the capacity of single edge node is limited and it is difficult to meet all business requirements at the same time. Therefore, this article proposes a task allocation mechanism based on cooperative edge computing. Firstly, a task allocation model based on cooperation of two edge nodes is established to minimize the average task completion delay while meeting business requirements. Secondly, the Two-edge-node Cooperative-task Allocation based on Improved Particle Swarm Optimization (TCA-IPSO) algorithm is proposed, which applies the crossover and mutation strategy in genetic algorithm to improve the particle swarm optimization algorithm, and solves the problem that the task allocation scheme in cooperation is prone to fall into a local optimum. Finally the simulation results show that the proposed TCA-IPSO algorithm reduces the average task completion delay by 53.8% and 36.0% compared to the benchmark and QoS-based Task Distribution (QBTD) algorithm.

As a mode of processing task request, edge computing paradigm can reduce task delay and effectively alleviate network congestion caused by the proliferation of Internet of things(IoT) devices compared with cloud computing. However, in the actual construction of the network, there are various edge autonomous subnets in the adjacent areas, which leads to the possibility of unbalance of server load among autonomous subnets during the peak period of task request. In this paper, a deep reinforcement learning algorithm is proposed to solve the complex computation offloading problem for the heterogeneous Edge Computing Server(ECS) collaborative computing. The problem is solved based on the real-time state of the network and the attributes of the task, which adopts Actor Critic and Policy Gradient's Deep Deterministic Policy Gradient(DDPG) to make optimized decisions of computation offloading. Considering multi-task, the heterogeneity of edge subnet and mobility of edge devices, the proposed algorithm can learn the network environment and generate the computation offloading decision to minimize the task delay.The simulation results show that the proposed DDPG-based algorithm is competitive compared with the Deep Q Network(DQN) algorithm and Asynchronous Advantage Actor-Critic(A3C) algorithm. Moreover, the optimal solutions are leveraged to analyze the influence of edge network parameters on task delay.

As a novel computing technology closer to business ends, edge computing has become an effective solution for delay sensitive business of power Internet of Things (IoT). However, the uneven spatial and temporal distribution of business requests in edge network leads to a significant difference in business busyness between edge nodes. Due to the natural lightweight and portability, container migration has become a critical technology for load balancing, thereby optimizing the resource utilization of edge nodes. To this end, this paper proposes a container migration-based decision-making (CMDM) mechanism in power IoT. First, a load differentiation matrix model between edge nodes is constructed to determine the timing of container migration. Then, a container migration model of load balancing joint migration cost (LBJC) is established to minimize the impact of container migration while balancing the load of edge network. Finally, the migration priority of containers is determined from the perspective of resource correlation and business relevance, and by introducing a pseudo-random ratio rule and combining the local pheromone evaporation with global pheromone update at the same time, a migration algorithm based on modified Ant Colony System (MACS) is designed to utilize the LBJC model and thus guiding the choice of possible migration actions. The simulation results show that compared with genetic algorithm (GA) and Space Aware Best Fit Decreasing (SABFD) algorithm, the comprehensive performance of CMDM in load balancing joint migration cost is improved by 7.3% and 12.5% respectively.

Orthogonal and single-factor experiments were used to investigate the remediation effect of single and mixed washing on arsenic-contaminated soil from a typical non-ferrous metal smelter. The optim...

To evaluate urban flood risk while considering spatial and temporal characteristics, this paper establishes an assessment method based on a coupled hydrodynamic model and a fuzzy comprehensive evaluation method. An assessment system is developed using hydrologic, social and economic factors. In addition, hydrology factors are obtained by the coupled hydrodynamic model. The hydrodynamic model is solved using the three-cascade method of the Saint–Venant equations for a river system, and the surface runoff is solved using a modified Roe-type approximate Riemann solver. The hydrology results are used as hydrologic factors and directly reflect the inundation of the subsequent assessment. Afterward, an analytic hierarchy process is used to calculate the weights of the assessment indices. Then, the urban flood risk is analyzed using the fuzzy comprehensive evaluation method. Five different rainfall events in Quzhou City are simulated and evaluated. The numerically computed results compare well with the statistical data and indicate an extreme inundation depth of more than 3 m. In addition, the assessment risk of Quzhou City is at level IV (high). This study shows that combining the assessment method with the coupled hydrodynamic model efficiently reflects the urban flood risk by considering flood, social and economic data.

The method for detection of circulating tumor cells (CTCs) is considered as a promising cancer liquid biopsy technique. However, due to the rarity and heterogeneity, it is still a challenging task to capture CTC with high purity and viability from blood for the following enumeration and molecular analysis. Herein, we fabricated a hydrogel-chitosan nanofiber substrate to effectively capture the target cancer cells, assisted by the poly(carboxybetaine methacrylate) (pCBMA) hydrogel and the anti-epithelial cell adhesion molecule (anti-EpCAM) antibody. The pCBMA hydrogel layer was fabricated by free radical polymerization to provide an antifouling surface, which could help to reduce the non-specific capture of blood cells to improve the capture purity of CTC. Then, chitosan nanofibers were introduced onto the hydrogel layer to provide a nanostructured surface to improve the capture efficiency. Finally, the capture yield of artificial blood samples on the anti-EpCAM modified hydrogel-nanofiber substrate was up to 79.9%, revealing the potential application of the hydrogel-nanofiber substrate on efficient and sensitive capture of rare circulating tumor cells.

The recent development in plasmon-enhanced electrochemical hydrogen production provides an alternative approach to address the bottleneck of low hydrogen production efficiency in the conventional photocatalysis. To achieve high-efficiency plasmonic catalysis, the development of catalytically active Schottky heterostructure is essential. Herein, we propose a 3D bicontinuous nanoporous plasmonic heterostructure for hydrogen evolution reaction (HER) by growing HER-active monolayer MoS2 on the internal surfaces of plasmonic 3D nanoporous gold (MoS2@NPG). The catalytically active plasmonic heterostructure with a large specific surface area and high electric conductivity exhibits superior photoelectrochemical activities towards electrochemical hydrogen production at both low onset potential of −70 mV vs RHE and the Tafel slope of 38 mV dec−1 under visible light illumination. The outstanding HER performance can be attributed to the efficient transfer of plasmon-generated hot electrons from NPG to monolayer MoS2 as well as the effective electron–hole separation by the Schottky barriers at MoS2/NPG interfaces.

Efficient crop improvement depends on the application of accurate genetic information contained in diverse germplasm resources. Here we report a reference-grade genome of wild soybean accession W05, with a final assembled genome size of 1013.2 Mb and a contig N50 of 3.3 Mb. The analytical power of the W05 genome is demonstrated by several examples. First, we identify an inversion at the locus determining seed coat color during domestication. Second, a translocation event between chromosomes 11 and 13 of some genotypes is shown to interfere with the assignment of QTLs. Third, we find a region containing copy number variations of the Kunitz trypsin inhibitor (KTI) genes. Such findings illustrate the power of this assembly in the analysis of large structural variations in soybean germplasm collections. The wild soybean genome assembly has wide applications in comparative genomic and evolutionary studies, as well as in crop breeding and improvement programs., Wild relatives of crop plants are invaluable germplasm for genetic improvement. Here, Xie et al. report a reference-grade wild soybean genome and show that it can be used to identify structural variation and refine quantitative trait loci.

With the acceleration of globalization, trade between countries has become more and more frequent; as a kind of commonly used heavy lifting equipment, the influence of the quayside crane on environment during the production stage has attracted wide attention. In this paper, the world’s largest quayside crane manufacturer was selected as the study object. The environmental load of five workshops (NC pre-treatment workshop, assembling workshop, sand milling workshop, painting workshop and steel structure workshop) involved in the quayside crane (QC) production stage was studied by using the ReCiPe model; the normalized values of the 14 overall pollutants in each workshop were 1248.64, 576.75, 214.27, 85.26 and 76.69, respectively. The results showed that the sand milling workshop was the biggest electricity consumer of all processes. The sensitivity analysis revealed that the environmental pollution load was the most sensitive to the electricity consumption; the scenario analysis indicated that with the proportion of China’s renewable resources in the process of electricity generation becoming larger and larger, in comparison with that of in 2015, up to 2050, the quantity of PM 2.5 generated during the production process of QC will drop from 832 to 408 kg (high-speed development)/342 kg (low-speed development), and it is expected that the China’s haze problem could be effectively curbed in the future. Finally, the research results of this article also pointed out the direction for the future technical innovation of the QC industry.

Localized surface plasmon resonance (LSPR) excitation enhanced chemical and electrochemical reactions represent a promising pathway for solar-to-chemical energy conversion. However, plasmonic catalysts usually suffer from low collection efficiency of hot charge carries generated by LSPR excitation due to short lifetime of hot carriers and fast electron-hole recombination. Schottky barriers between plasmonic catalysts and semiconducting supports have been utilized to prevent the electron-hole recombination. However, the interfacial barriers also hinder low-energy hot charge collection and thus affect solar-to-chemical energy conversion efficiency. Here we report that bicontinuous nanoporous gold as a Schottky barriers-free direct plasmonic catalyst can significantly enhance electro-oxidation of alcohol molecules. A high energetic hole yield of 0.486% is achieved, which is 4 times higher than that of discrete plasmonic AuAg nanoparticles. The direct plasmonic catalyst offers the highest methanol oxidation current density of 531 µA cm−2 among all known Au catalysts. This work provides compelling evidence that higher hot carrier collection efficiency can be achieved from direct plasmonic electrocatalysis without the assistance of Schottky junctions and has important implications in developing high efficiency plasmonic catalysts for photo-enhanced electrochemical reactions.

Circulating tumor cells (CTCs) have been considered as a significant biomarker for cancer metastasis and relapse. Effective detection of CTCs will play an important role in early cancer diagnosis, prognosis, progress monitoring, and personalized therapy. In this work, we developed a polystyrene (PS) nanosphere substrate to capture CTCs from whole blood samples. Bovine serum albumin (BSA), as an antifouling molecule, and folic acid, as a recognizing agent, were modified onto the surface of PS nanospheres via self-polymerization of dopamine. 8 HeLa cells could be captured when 10 cells were spiked into 1 mL of the whole blood sample. Then, the captured target cells were further proliferated through an in situ culture strategy on the polystyrene (PS) nanosphere substrate, and nearly 80 HeLa cells were obtained from 1 captured cell after 7 days of in situ culture, revealing the potential application for CTC isolation and proliferation.

Three-dimensional porous materials with bicontinuous open porosity represent a new class of functional materials for various applications. Top-down dealloying has been demonstrated to be one of the most effective ways to fabricate 3D porous materials. Vapor phase dealloying, which makes use of the saturated vapor pressure difference between the constituent components in an alloy for selectively removing a less stable element or phase, is a promising versatile method for fabricating porous materials from active metals to inorganic elements. Here, using nickel-zinc and germanium-zinc alloys as the prototypes of single-phase and two-phase precursors, respectively, we report the fabrication of 3D bicontinuous porous Ni and Ge by vapor phase dealloying on the basis of selective element or selective phase evaporations. We also show the incorporation of vapor phase dealloying with chemical vapor deposition for the one-pot growth of 3D nanoporous graphene and the functional applications of vapor phase dealloyed porous Ge as Li ion battery electrodes. This study shines lights on the versatility of vapor phase dealloying for the fabrication of bicontinuous porous materials for a wide range of functional applications.

Circulating tumor cells (CTCs) acquire mesenchymal markers (e.g., N-cadherin) and lose epithelial markers (e.g., epithelial cell adhesion molecule, EpCAM) during the epithelial-mesenchymal transition (EMT) and are therefore ideal biomarkers of tumor metastasis. However, it is still a challenge to efficiently capture and detect circulating tumor cells with different phenotypes simultaneously. In this work, to obtain aptamers targeting N-cadherin in the native conformation on live cells, we established stable N-cadherin overexpressing cells (N-cadherin cells) and used these cells to identify a panel of N-cadherin-specific aptamers through the cell-SELEX approach. Two aptamer candidates obtained after 12 rounds of selection showed a low equilibrium dissociation constant in the nanomolar range, indicating high binding affinity. The truncated aptamer candidate NC3S showed the highest binding affinity to N-cadherin cells with a low Kd value of 20.08 nM. The SYL3C aptamer was reported to target cancer cell surface biomarker EpCAM. Then, we synthesized two kinds of aptamer-modified magnetic nanoparticles (SYL3C-MNPs and NC3S-MNPs). Both SYL3C and NC3S aptamers possess excellent capture specificity and efficiency for the target cells. The aptamer-MNP cocktail exhibits a considerable capture efficiency and sensitivity for rare cancer cells of epithelial and mesenchymal phenotypes. Furthermore, no CTCs were found in blood samples from healthy donors, while CTCs were successfully isolated by using the aptamer-MNP cocktail for 15 out of 16 samples collected from patients. In summary, the two kinds of aptamer-modified MNPs could be utilized as a promising tool for capturing CTCs from clinical samples.

To mitigate the projected global warming in the 21st century, it is well-recognized that society needs to cut CO2 emissions and other short-lived warming agents aggressively. However, to stabilize the climate at a warming level closer to the present day, such as the “well below 2 ∘C” aspiration in the Paris Agreement, a net-zero carbon emission by 2050 is still insufficient. The recent IPCC special report calls for a massive scheme to extract CO2 directly from the atmosphere, in addition to decarbonization, to reach negative net emissions at the mid-century mark. Another ambitious proposal is solar-radiation-based geoengineering schemes, including injecting sulfur gas into the stratosphere. Despite being in public debate for years, these two leading geoengineering schemes have not been directly compared under a consistent analytical framework using global climate models. Here we present the first explicit analysis of the hydroclimate impacts of these two geoengineering approaches using two recently available large-ensemble (>10 members) model experiments conducted by a family of state-of-the-art Earth system models. The CO2-based mitigation simulation is designed to include both emission cuts and carbon capture. The solar-radiation-based mitigation simulation is designed to inject sulfur gas strategically at specified altitudes and latitudes and run a feedback control algorithm to avoid common problems previously identified such as the overcooling of the tropics and large-scale precipitation shifts. Our analysis focuses on the projected aridity conditions over the Americas in the 21st century in detailed terms of the potential mitigation benefits, the temporal evolution, the spatial distribution (within North and South America), the relative efficiency, and the physical mechanisms. We show that sulfur injection, in contrast to previous notions of leading to excessive terrestrial drying (in terms of precipitation reduction) while offsetting the global mean greenhouse gas (GHG) warming, will instead mitigate the projected drying tendency under RCP8.5. The surface energy balance change induced by sulfur injection, in addition to the well-known response in temperature and precipitation, plays a crucial role in determining the overall terrestrial hydroclimate response. However, when normalized by the same amount of avoided global warming in these simulations, sulfur injection is less effective in curbing the worsening trend of regional land aridity in the Americas under RCP8.5 when compared with carbon capture. Temporally, the climate benefit of sulfur injection will emerge more quickly, even when both schemes are hypothetically started in the same year of 2020. Spatially, both schemes are effective in curbing the drying trend over North America. However, for South America, the sulfur injection scheme is particularly more effective for the sub-Amazon region (southern Brazil), while the carbon capture scheme is more effective for the Amazon region. We conclude that despite the apparent limitations (such as an inability to address ocean acidification) and potential side effects (such as changes to the ozone layer), innovative means of sulfur injection should continue to be explored as a potential low-cost option in the climate solution toolbox, complementing other mitigation approaches such as emission cuts and carbon capture (Cao et al., 2017). Our results demonstrate the urgent need for multi-model comparison studies and detailed regional assessments in other parts of the world.

The bubbles in the liquid film are important to improve the chemical reaction rate and the efficiency of heat and mass transfer. However, bubbles in annular flow have not been studied intensively like waves on film surface or droplets. Planar Laser-induced Fluorescence (PLIF) was employed to investigate the film bubbles in vertical upward annular flow. The subject of this paper is to study the correlation between the area, the gas holdup of bubbles in the liquid film and gas-liquid superficial velocity. The results show that the above parameters decrease with the increase of the gas superficial velocity, however, with the increase of liquid superficial velocity they are not always increasing. The variation of these parameters with the liquid superficial velocity is also diverse under different gas superficial velocity. The statistical characteristics of bubble area are studied and it can reveal how the mean bubble area decreases as the flow conditions change.

Falling film is widely applied in many industries, such as evaporation, condensation, chemical reaction and distillation. In order to investigate the influence of the liquid temperature on the wave characteristics in the free-falling film that is subjected to the sensible heating, instantaneous measurements of the film thickness using planar laser-induced fluorescence are performed. Experiments are carried out at liquid temperature that ranges from 24 °C to 52 °C. The spatiotemporal flow structure of falling film is reconstructed and analyzed at different temperatures. It is found that the frequency and the amplitudes of the large waves change with the temperature simultaneously, and the substrate regions become more smoother and wider with the temperature rising. The profiles of film thickness probability density function and the power spectrum density function are presented and discussed.

This paper examines the design and the process used to carry out the China Fertility Survey 2017, a national representative survey that collected data on fertility desire, childbearing behavior, the use of childbearing services, and the determinants of childbearing behavior. The sampling method adopted was three-stage stratified probabilities proportional to size (PPS), and survey implementation made use of Computer Assisted Personal Interviewing (CAPI). CAPI played a significant role in survey design, last-stage sampling, interviewer training, face-to-face interviews, and questionnaire review and quality control. The survey results were compared with relevant data in the Integrated Management Information System for Population and Family Planning to check consistency. Ex post facto weighting was applied to correct sample structure bias. The process used to acquire accurate personal information is summarized. Suggestions based on consideration of sampling frame distortion by population mobility and other factors are put forward in the hope of improving similar sampling surveys in the future.

The theoretical framework of the direct information retrieval method is presented in phase-contrast computed tomography. Numerical simulations are also performed, which reveal that the proposed method provides comparable results of the reverse projection method with short computational time. Furthermore, the compatibility with the existing data preprocessing methods and iterative reconstruction algorithms is discussed., Grating-based X-ray differential phase-contrast imaging has attracted a great amount of attention and has been considered as a potential imaging method in clinical medicine because of its compatibility with the traditional X-ray tube source and the possibility of a large field of view. Moreover, phase-contrast computed tomography provides three-dimensional phase-contrast visualization. Generally, two-dimensional information retrieval performed on every projection is required prior to three-dimensional reconstruction in phase-contrast computed tomography. In this paper, a three-dimensional information retrieval method to separate absorption and phase information directly from two reconstructed images is derived. Theoretical derivations together with numerical simulations have been performed to confirm the feasibility and veracity of the proposed method. The advantages and limitations compared with the reverse projection method are also discussed. Owing to the reduced data size and the absence of a logarithm operation, the computational time for information retrieval is shortened by the proposed method. In addition, the hybrid three-dimensional images of absorption and phase information were reconstructed using an absorption reconstruction algorithm, hence the existing data pre-processing methods and iterative reconstruction algorithms in absorption reconstruction may be utilized in phase reconstruction immediately.

Nickel lysine salen complex was successfully synthesized via a stepwise procedure and applied as a heterogeneous catalyst for styrene epoxidation. For comparison, several other transition metal (Mn, Fe, Co, and Cu) lysine salen complexes were also synthesized. The prepared catalysts were characterized by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX). Data obtained by FT-IR and Raman spectroscopy indicated the formation of C=N bonds and the complexation of these bonds with metal ions. SEM analysis revealed that the complexation of metal ions with the C=N involves the change in surface morphology of samples. In addition, atomic percent composition of samples was obtained from EDX spectra, which was the complementary evidence for the formation of complexes. Results of catalytic measurements showed that a high conversion of styrene (91.51%) and selectivity to styrene oxide (91.99%) could be achieved over the nickel lysine salen complex with tert-butyl hydroperoxide as the oxidant. When the catalyst was reused the conversion of styrene decreased but the selectivity to styrene oxide still remained high.

Ammonia borane (AB) has been identified as one of the most promising candidates for chemical hydrogen storage. However, the practical application of AB for hydrogen production is hindered by the need of efficient and inexpensive catalysts. For the first time, we report that the incorporation of Mo into Cu@Co core-shell structure can significantly improve the catalytic efficiency of hydrogen generation from the hydrolysis of AB. The Cu0.81@Mo0.09Co0.10 core-shell catalyst displays high catalytic activity towards the hydrolysis dehydrogenation of AB with a turnover frequency (TOF) value of 49.6 molH2 molcat−1 min−1, which is higher than most of Cu-based catalysts ever reported, and even comparable to those of noble-metal based catalysts. The excellent catalytic performance is attributed to the multi-elements co-deposition effect and electrons transfer effect of Cu, Mo and Co in the tri-metallic core-shell NPs.

To deliver siRNA efficiently, prevailing conventional lipid or polymer encapsulation often needs multi-step compounding methods, which may inevitably introduce cationic or other components and may lead to cytotoxicity or an immune response. Herein, we present a novel enzymatic synthetic approach to produce tumor-targetable RNAi nanoflowers. The RNAi nanoflowers are mainly composed of multiple tandem copies of siRNA precursors by rolling circle transcription (RCT), and produce large amounts of siRNA to silence Bcl-2 gene expression after cellular uptake, which can overcome the problem of low loading capacity. In particular, the RNAi microspheres (RNAi-MS) were condensed into nanosized complexes (RNAi nanospheres, RNAi-NS) by cholesterol-modified DNA strands without the assistance of polycationic agents. RNAi-NS are entirely composed of nucleic acid, giving them lower cytotoxicity and immunogenicity, which can be caused by synthetic polycationic reagents. In addition, the RNAi nanoflowers can also integrate DNA aptamers that bind specifically to target membrane proteins for cell-targeting. Therefore, thousands of copies of siRNA will be delivered to cells specifically, and this RNAi nanoflower system will have great potential for siRNA delivery and biomedical applications.

Efficient, durable and low-cost electrocatalysts that accelerate sluggish oxygen reduction reaction kinetics are urgently needed for the energy conversion techniques, such as metal-air batteries and fuel cells. In this work, we develop a molten-salt-assisted thermal emitting approach to transform the cheap and easily obtainable bulk ferric (III) oxide powder into a highly efficient Fe single atom catalyst for cathodic oxygen reduction reaction. Benefiting from the strong polarity force of ionized cations and anions, the molten salt effectively facilitates breakage of chemical bonding in bulk Fe2O3 and volatilization of Fe species far below the melting point of Fe2O3 (1841 K), lowering the consumption of energy and time needed in the synthetic procedure. The vaporized Fe species are subsequently anchored onto the surface of nitrogen-doped porous carbon, evolving the single-atom “Fe-N4-O2” site catalyst. The obtained catalyst presents an excellent oxygen reduction reaction performance with half-wave potential of 0.896 V vs RHE in alkaline media, comparable to the most efficient non-precious metal catalysts and outperforming the benchmark system Pt/C. Furthermore, this method is demonstrated to be valid for synthesis of non-noble-metal single atom catalysts (metal = Co, Mn, Cu, Ni) by changing different metal oxides precursors.

Tuning surface structures by bottom-up synthesis has been demonstrated as an effective strategy to improve the catalytic performances of nanoparticle catalysts. Nevertheless, the surface modification of three-dimensional nanoporous metals, fabricated by a top-down dealloying approach, has not been achieved despite great efforts devoted to improving the catalytic performance of three-dimensional nanoporous catalysts. Here we report a surfactant-modified dealloying method to tailor the surface structure of nanoporous gold for amplified electrocatalysis toward methanol oxidation and oxygen reduction reactions. With the assistance of surfactants, {111} or {100} faceted internal surfaces of nanoporous gold can be realized in a controllable manner by optimizing dealloying conditions. The surface modified nanoporous gold exhibits significantly enhanced electrocatalytic activities in comparison with conventional nanoporous gold. This study paves the way to develop high-performance three-dimensional nanoporous catalysts with a tunable surface structure by top-down dealloying for efficient chemical and electrochemical reactions., Tuning the ratio of facets in materials can affect catalytic activity but methods to achieve this can be difficult to control. Here, using surfactants during dealloying, the authors prepare nanoporous gold with controlled facet ratios and show how it can significantly improve electrocatalytic activity.

Contiguous mudflats exist along the coast zone of the Bohai Bay in the western part of the Bohai Sea of China. They are generally suitable for land reclamation, which can ease the contradiction between land resource shortage and the demand for development, because mudflats are important geomorphological systems which provide land resources. The shoreline at the Bohai Bay has experienced significant changes since 2003 due to high intensity reclamation. Environmental impacts of reclamation at different stages, especially on the tidal wave system, have attracted worldwide attention. However, there is still a lack of understanding on the cumulative response process of the tidal wave system and its response mechanism to high intensity development of mudflats. In this study, six periods were selected as representative reclamation stages in the Bohai Bay: 2003, 2006, 2012, future planning, and 0 m and −5 m reclamation stages. A two-dimensional tidal wave mathematical model was developed to analyze the cumulative changing process and dominant mechanism of the change of the tidal wave system by comparing effects of reclamation of the entire bay and cumulative effects of sequential reclamation projects, as well as studying the relations between the tidal wave change and tidal range on the shore segment where the reclamation project is located. Based on the analysis results, the influence of reclamation in the Bohai Bay on the M2 constituent tide was much greater than that on the K1 constituent tide, especially on the M2 constituent tide amphidromic point outside of the Yellow River mouth. The movement distance of the M2 constituent tide amphidromic point outside the Yellow River mouth for the aforementioned reclamation stages compared to its location in 2003 was about 1, 10, 22.5, 27.3, and 83.8 km, respectively. In contrast, the maximum movement distance of the other M2 constituent tide amphidromic point outside Qinhuangdao and the unique K1 constituent tide amphidromic point in the Bohai Sea for the aforementioned reclamation stages compared to their conditions in 2003 were about 5.9 and 6.3 km, respectively. With the increase of the reclamation scale, the M2 constituent tide amphidromic point outside of the Yellow River mouth first moved southeastward, and then moved northeastward, and the tidal range of the western Bohai Bay first increased and then decreased, while the speed of tidal wave propagation first accelerated and then stabilized during the 0 m reclamation stage. During the −5 m reclamation stage, the tidal wave system experienced obvious changes, however, the tidal properties inside the bay remained the same. The average tidal current velocity of the bay decreased with the increase of the reclamation scale, and the tidal current velocity of 2003, 2012, future planning and −5 m reclamation stages were 0.33–0.37, 0.3–0.34, 0.29–0.31, and 0.16–0.17 m/s, respectively. When reclamation projects were performed one by one counterclockwise from Caofeidian (future planning) in the north to south until all the future planned reclamation projects were completed, the M2 constituent tide amphidromic point first moved southwestward, and then moved southeastward. In semi-closed bays influenced by rotational tidal wave, the impact intensity of reclamation projects to the tidal wave system depends mostly on the tidal range of the coast where the reclamation projects are located. The greater the tidal range, the more obvious the effects of the reclamation projects will be on the tidal wave system. Continuous reclamation will increase flooding risks and tendency of siltation in the bay, weaken the water exchange rate in the bay, affect scouring and silting, as well as impact the design and defense standards of coastal engineering projects near the Yellow River mouth.

China׳s island and reef coasts are mainly distributed along the coasts of Zhejiang and Fujian provinces. These areas have favorable deep-water conditions and great development potential. The Zhoushan Archipelago is a typical island and reef coast. In the midst of the islands, there are many tidal channels with high water depth and high current velocity. Daishan Island is located on the northern part of the Zhoushan Archipelago. The sea north of Daishan Island can be characterized as having great water depth (generally between 10 and 20 m), high current velocity (the maximum measured value is about 2 m/s), and hyperconcentrated suspended sediment (annual average concentration under normal weather conditions is about 0.6 kg/m 3 ). Sediment transport is influenced by the co-action of waves and currents. Land reclamation can ease the contradiction between the desire for development and the land resource shortage on island and reef coasts. Land reclamation generally starts from deposition-promoting projects on island and reef coasts with hyperconcentration of suspended sediment with the aim of reducing the reclamation cost. Based on the morphodynamic characteristics of the sea area near north of Daishan Island, a two-dimensional mathematical model was developed to analyze the co-action of current and waves and the model was verified for spring as well as neap tides in 2007 and 2012. The simulated values of tidal stages, tidal current velocities, tidal current directions, and suspended sediment concentration at 15 stations in 2007 and 9 stations in 2012 were in good agreement with the in-situ measured values. Furthermore, the simulated magnitude and pattern of erosion and sedimentation agreed well with the observations. This model was used to evaluate the effects of a proposed siltation scheme on the hydrodynamic environment and morphological change of the study area. The results of this study can inform the protection, development, and utilization of shoal-channels on island and reef coasts, as well provide a scientific basis for comprehensive maritime protection and development.

The comprehensive effects of anthropogenic aerosols (sulfate, black carbon, and organic carbon) on terrestrial aridity were simulated using an aerosol–climate coupled model system. The results showed that the increase in total anthropogenic aerosols in the atmosphere from 1850 to 2010 had caused global land annual mean precipitation to decrease by about 0.19 (0.18, 0.21) mm day−1, where the uncertainty range of the change (minimum, maximum) is given in parentheses following the mean change, and reference evapotranspiration ET0 (representing evapotranspiration ability) to decrease by about 0.33 (0.31, 0.35) mm day−1. The increase in anthropogenic aerosols in the atmosphere from 1850 to 2010 had caused land annual mean terrestrial aridity to decrease by about 3.0% (2.7%, 3.6%). The areal extent of global total arid and semiarid areas had reduced due to the increase in total anthropogenic aerosols in the atmosphere from preindustrial times. However, it was found that the increase in anthropogenic aerosols in the atmosphere had enhanced the terrestrial aridity and thus resulted in an expansion of arid and semiarid areas over East and South Asia. The projected decrease in anthropogenic aerosols in the atmosphere from 2010 to 2100 will increase global land annual mean precipitation by about 0.15 (0.13, 0.16) mm day−1 and ET0 by about 0.26 (0.25, 0.28) mm day−1, thereby producing a net increase in terrestrial aridity of about 2.8% (2.1%, 3.6%) and an expansion of global total arid and semiarid areas.

X-ray grating interferometry can provide substantially increased contrast over traditional attenuation-based techniques in biomedical applications, and therefore novel and complementary information. Recently, special attention has been paid to quantitative phase retrieval in X-ray grating interferometry, which is mandatory to perform phase tomography, to achieve material identification, etc. An innovative approach, dubbed “Reverse Projection” (RP), has been developed for quantitative phase retrieval. The RP method abandons grating scanning completely, and is thus advantageous in terms of higher efficiency and reduced radiation damage. Therefore, it is expected that this novel method would find its potential in preclinical and clinical implementations. Strictly speaking, the reverse projection method is applicable for objects exhibiting only absorption and refraction. In this contribution, we discuss the phase retrieval with the reverse projection method for general objects with absorption, refraction and scattering simultaneously. Especially, we investigate the influence of the object's scattering on the retrieved refraction signal. Both theoretical analysis and numerical experiments are performed. The results show that the retrieved refraction signal is the product of object's refraction and scattering signals for small values. In the case of a strong scattering, the reverse projection method cannot provide reliable phase retrieval. Those presented results will guide the use of the reverse projection method for future practical applications, and help to explain some possible artifacts in the retrieved images and/or reconstructed slices.

Recovering pure and viable circulating tumor cells (CTCs) from blood has been a challenging task for molecular characterization and functional analysis, which has attracted wide attention these days. Herein, we fabricate a thermoresponsive chitosan nanofiber substrate to effectively capture, purify, and release the target cancer cells, assisted by PNIPAAm brushes and DNA hybridization. The PNIPAAm brushes are designed to enable WBCs to detach from aptamer-PNIPAAm-chitosan-nanofiber (aptamer-P-CNFs) surfaces during the conformational transition. Meanwhile these specific captured CTCs are retained at a high purity. Moreover, effective and intact release of CTCs from the substrates without any foreign agents is realized by complementary sequences efficiently hybridizing with aptamers, and the specific cell release makes CTCs further purified. The present work provides a new strategy in the design of biointerface for recovering target CTCs from whole blood samples with high purity.

Herein, we fabricated efficient MR imaging probes by incorporating gadolinium oxide nanoparticles (Gd2O3) and gadolinium hybrid nanoparticles (GH) within RBCs. The Gd2O3 and GH encapsulated in the RBCs exhibited high relaxation rates and revealed high sensitivity for T1 MR imaging.

Extreme rarity and inherent heterogeneity of circulating tumor cells (CTCs) result in a tremendous challenge for the CTC isolation from patient blood samples with high efficiency and purity. Current CTC isolation approaches mainly rely on the epithelial cell adhesion molecule (EpCAM), which may significantly reduce the ability to capture CTCs when the expression of EpCAM is lost or down-regulated in epithelial-mesenchymal transition. Here, a rapid and highly efficient method is developed to isolate and identify heterogeneous CTCs with high efficiency from patient blood samples using the fluorescent-magnetic nanoparticles (F-MNPs). A dual-antibody interface targeting EpCAM and N-cadherin is fabricated onto the F-MNPs to capture epithelial CTCs as well as mesenchymal CTCs from whole blood samples. The poly(carboxybetaine methacrylate) brushes of excellent antifouling properties are employed to decrease nonspecific cell adhesion. Moreover, the F-MNPs provide a prompt identification strategy for heterogeneous CTCs (F-MNPs+, Hoechst 33342+, and CD45-) that can directly identify CTCs in a gentle one-step processing within 1 h after isolation from patient blood samples. This has been demonstrated through artificial samples as well as patient samples in details.

Inspired by recent experimental results, we report on a revised noise model of dark-field imaging using a grating interferometer. The accurate knowledge of the noise of the dark-field image is essential for noise reduction and image quality improvement. A revised noise model is theoretically derived in terms of the standard deviation of the dark-field image. While a low visibility assumption was made in previous models, the revised noise model makes no assumption on the visibility. It is​ shown by synchrotron radiation experimental results that, with a high visibility, the revised noise model agreed quantitatively with experimentally measured values, while previous models overestimated the noise present in the dark-field image significantly. Therefore, the revised model provides an accurate description of the noise behavior of grating-based dark-field imaging, and can be of use for energy-resolved dark-field imaging and potential dose optimizations.

Mobile edge computing is a new computing paradigm, which pushes cloud computing capabilities away from the centralized cloud to the network edge to satisfy the increasing amounts of low-latency tasks. However, challenges such as service interruption caused by user mobility occur. In order to address this problem, in this article, we first propose a multiple service placement algorithm, which initializes the placement of each service according to the user’s initial location and their service requests. Furthermore, we build a network model and propose a based on Lyapunov optimization method with long-term cost constraints. Considering the importance of user mobility, we use the Kalman filter to correct the user’s location to improve the success rate of communication between the device and the server. Compared with the traditional scheme, extensive simulation results show that the dynamic service migration strategy can effectively improve the service efficiency of mobile edge computing in the user’s mobile scene, reduce the delay of requesting terminal nodes, and reduce the service interruption caused by frequent user movement.

Failure instances in distributed computing systems (DCSs) have exhibited temporal and spatial correlations, where a single failure instance can trigger a set of failure instances simultaneously or successively within a short time interval. In this work, we propose a correlated failure prediction approach (CFPA) to predict correlated failures of computing elements in DCSs. The approach models correlated-failure patterns using the concept of probabilistic shared risk groups and makes a prediction for correlated failures by exploiting an association rule mining approach in a parallel way. We conduct extensive experiments to evaluate the feasibility and effectiveness of CFPA using both failure traces from Los Alamos National Lab and simulated datasets. The experimental results show that the proposed approach outperforms other approaches in both the failure prediction performance and the execution time, and can potentially provide better prediction performance in a larger system.

Over the last decade, significant progress has been made to develop sensitive devices for the capture of circulating tumor cells (CTCs) from blood of cancer patients. However, simple capture and counting of CTCs cannot provide effective information for understanding the biology of them. In this work, a functional biointerface is fabricated for specific capture and nondestructive release of CTCs from blood samples. A nanostrucure of porous network based on chitosan nanofibers is fabricated by electrospinning, to mimic the function of extracellular matrices, and then the poly(carboxybetaine methacrylate) (pCBMA) brushes integrating onto nanofiber interface provide the effect of interfacial properties to control nonspecific cell adhesion and the multivalent immobilization of aptamers to induce high efficient and specific CTC capture. Furthermore, a complementary sequence is used to efficiently hybridize with the aptamer to achieve nondestructive release of the captured target cells, assisted by the flexible space provided by pCBMA brushes. This work also shows how nanostructure and the interface molecules regulate the morphology of the captured CTCs, and reveals the importance of the controllable cell morphology on biointerface for an effective nondestructive release of the captured CTCs.

Wearable technology, as well as continuous monitoring of the human physiological activities and behavior, allows the physiological and biochemical indicators in daily life. The wearable sensor gives a strategy for observing the boundaries of continuous physiological and sports during preparing and serious games. Hence, this work has proposed a far off Remote Health Monitoring (RHM) interconnect design dependent on the Internet of things. This is, in progression, make development in wellbeing observing and tolerant gear and Internet abilities of the distant of significant plausible checking images, and referral Empower. These arrangements are described by advanced radio correspondence and low force utilization and require a keener physiological sensor. With the development of wireless communication, you need to connect the deployment physiological sensor in the patient's environment and wear a wireless body area network. These parameters, performance can be used to detect the position of a particular pattern of motion that is designed to optimize, on the screen, the potential cause of injury in a specific sports training program for, it is more efficient. Wireless personal and local area network technology has been added to the normal IoT connectivity solutions are Wi-Fi and Bluetooth. Internet of Things (IoT) is a broad concept that includes the people around us of the wireless connection equipment.

Herein, we developed an inexpensive titanium dioxide (TiO2) nanofiber substrate for efficient and selective capture of circulating tumor cells (CTCs) from mimic patients’ samples. The TiO2 nanofiber substrates were fabricated by electrospinning in combination with the calcination process. The surface of nanofiber substrates was modified with the anti-adhesion molecule, bovine serum albumin (BSA) and the nucleolin aptamer AS1411, wherein, aptamer AS1411 specifically binds to the nucleolin protein overexpressed on the membrane surface of cancer cells. The formed TiO2 nanofiber substrates exhibited high efficacy and specificity to capture nucleolin positive cells through synergistic topographic interactions. Using the rare number of cell capture experiments, the capture efficiency of up to 75 % was achieved on the surface of the nanofiber substrate for rare number target cells spiked in the white blood cells (WBCs) from 1 mL whole blood samples. In conclusion, this study highlighted the potential of the TiO2-BSA-biotin-AS1411 nanofiber substrate as a highly efficient platform to realize the selective and specific capture of rare CTCs in the clinical settings.

Nitrogen-doped graphene exhibits high electrocatalytic activity toward the oxygen reduction reaction (ORR), which is essential for many renewable energy technologies. To maximize the catalytic efficiency, it is desirable to have both a high concentration of robust nitrogen dopants and a large accessible surface of the graphene electrodes for rapid access of oxygen to the active sites. Here, 3D bicontinuous nitrogen-doped mesoporous graphene synthesized by a low-temperature carbide-mediated graphene-growth method is reported. The mesoporous graphene has a mesoscale pore size of ≈25 nm and large specific surface area of 1015 m2 g-1 , which can effectively host and stabilize a high concentration of nitrogen dopants. Accordingly, it shows an excellent electrocatalytic activity toward the ORR with an efficient four-electron-dominated pathway and high durability in alkaline media. The synthesis route developed herein provides a new economic approach to synthesize bicontinuous porous graphene materials with tunable characteristic length, porosity, and chemical doping as high efficiency electrocatalysts for a wide range of electrochemical reactions.

Well-ordered MCM-41 materials with different loadings of NiO were prepared combining hydrothermal method using cetyltrimethylammonia bromide as the structure-directing agent in an ammonia aqueous solution with calcination. A series of characterization of the resulting samples revealed that the materials maintained ordered mesostructure of MCM-41 after loading NiO and NiO nanoparticles were highly dispersed in the mesoporous wall and on the external surface of MCM-41. Characterization results also unveiled that $$\hbox {Ni}^{2+ }$$ prefer to enter the pores that formed by silicone gel during the hydrothermal reaction and incorporated into the pore wall and then formed NiO during the calcination process. And the TEM images indicated that smaller size NiO nanoparticles are easier to be formed on the MCM-41 materials. Catalytic results revealed that NiO should be the catalytic active centers for the oxidation of styrene and Ni-based materials showed the efficient catalytic property. Synopsis Owing to high dispersion of nickel oxide on the MCM-41 support and synergistic effect between NiO nanoparticles and the support, 6Ni-MCM-41 gave higher conversion and selectivity compared to pure NiO nanoparticles.

Three-dimensional bicontinuous open (3DBO) nanoporosity has been recognized as an important nanoarchitecture for catalysis, sensing, and energy storage. Dealloying, i.e., selectively removing a component from an alloy, is an efficient way to fabricate nanoporous materials. However, current electrochemical and liquid-metal dealloying methods can only be applied to a limited number of alloys and usually require an etching process with chemical waste. Here, we report a green and universal approach, vapor-phase dealloying, to fabricate nanoporous materials by utilizing the vapor pressure difference between constituent elements in an alloy to selectively remove a component with a high partial vapor pressure for 3DBO nanoporosity. We demonstrate that extensive elements, regardless of chemical activity, can be fabricated as nanoporous materials with tunable pore sizes. Importantly, the evaporated components can be fully recovered. This environmentally friendly dealloying method paves a way to fabricate 3DBO nanoporous materials for a wide range of structural and functional applications., Conventional dealloying methods to produce bicontinuous open nanoporous structures for catalysis are limited to very few alloys and produce chemical waste. Here, the authors develop a green process, vapor-phase dealloying, to selectively remove high partial vapor pressure components and create nanoporosity in a wide range of alloys.

A three-image algorithm is proposed in order to retrieve the absorption, refraction and ultra-small-angle X-ray scattering (USAXS) properties of the object in X-ray analyzer-based imaging. Based on the Gaussian fitting to the rocking curve, the novel algorithm is theoretically derived and presented, and validated by synchrotron radiation experiments. Compared with multiple-image radiography, this algorithm only requires a minimum of three intensity measurements, and is therefore advantageous in terms of simplified acquisition procedure and reduced data collection times, which are especially important for specific applications such as in vivo imaging and phase tomography. Moreover, the retrieval algorithm can be specialized to particular cases where some degree of a priori knowledge on the object is available, potentially reducing the minimum number of intensity measurements to two. Furthermore, the effect of angular mis-alignment on the accuracy of the retrieved images was theoretically investigated, which can be of use in image interpretation and optimization of the data acquisition procedure.

The nanosize effect on electron–phonon interactions in free-electron noble metals has been a subject of intense discussion because of their important applications in physics, chemistry, and biomedicine. However, the interference from supports of dispersive nanoparticulate metals has led to controversial observations. We utilize freestanding, bicontinuous nanoporous gold (NPG) films to investigate electron–phonon interaction dynamics using ultrafast MeV electron diffraction. Compared to solid gold films, NPG shows faster electron–phonon interaction and thus noticeably higher electron–phonon coupling constant. The results demonstrate that surface states of electrons and phonons play an important role in electron–phonon coupling of nanostructured materials.

In this paper, we develop a low-cost size-based microfluidic chip using conventional polycarbonate membrane to isolate CTCs from blood, and propose a strategy to increase the capture efficiency before cell filtration by a size enlargement method utilizing modified microbeads specifically binding to CTCs. Up to 91% of target cells were isolated from whole blood samples using our microfluidic capture system at a flow rate of 1mL/min. Moreover, a WBC depletion process is introduced which greatly decreases the WBC retaining on the filter membrane. The tests of immunofluorescence analysis of cells captured on the membrane were performed, which demonstrates that the device could provide a dependable CTC identification and CTC count in whole blood samples. Finally, the device was further validated in the detection of CTCs from blood samples of cancer patients, and it indicates a promising capability to detect CTC response to treatment.

3D dealloyed nanoporous metals have emerged as a new class of catalysts for various chemical and electrochemical reactions. Similar to other heterogeneous catalysts, the surface atomic structure of the nanoporous metal catalysts plays a crucial role in catalytic activity and selectivity. Through surfactant-assisted bottom-up synthesis, the surface-structure modification has been successfully realized in low-dimensional particulate catalysts. However, the surface modification by top-down dealloying has not been well explored for nanoporous metal catalysts. Here, a surfactant-free approach to tailor the surface structure of nanoporous gold by surface relaxation via electrochemical redox cycling is reported. By controlling the scan rates, nanoporous gold with abundant {111} facets or {100} facets can be designed and fabricated with dramatically improved electrocatalysis toward the ethanol oxidation reaction.