Search

BACKGROUND Strategies for integrating artificial intelligence (AI) into thyroid nodule management require additional development and testing. We developed a deep-learning AI model (ThyNet) to differentiate between malignant tumours and benign thyroid nodules and aimed to investigate how ThyNet could help radiologists improve diagnostic performance and avoid unnecessary fine needle aspiration. METHODS ThyNet was developed and trained on 18 049 images of 8339 patients (training set) from two hospitals (the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, and Sun Yat-sen University Cancer Center, Guangzhou, China) and tested on 4305 images of 2775 patients (total test set) from seven hospitals (the First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China; the Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; the Guangzhou Army General Hospital, Guangzhou, China; the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; the First Affiliated Hospital of Sun Yat-sen University; Sun Yat-sen University Cancer Center; and the First Affiliated Hospital of Guangxi Medical University, Nanning, China) in three stages. All nodules in the training and total test set were pathologically confirmed. The diagnostic performance of ThyNet was first compared with 12 radiologists (test set A); a ThyNet-assisted strategy, in which ThyNet assisted diagnoses made by radiologists, was developed to improve diagnostic performance of radiologists using images (test set B); the ThyNet assisted strategy was then tested in a real-world clinical setting (using images and videos; test set C). In a simulated scenario, the number of unnecessary fine needle aspirations avoided by ThyNet-assisted strategy was calculated. FINDINGS The area under the receiver operating characteristic curve (AUROC) for accurate diagnosis of ThyNet (0·922 [95% CI 0·910-0·934]) was significantly higher than that of the radiologists (0·839 [0·834-0·844]; p

A scheme for achieving atom localization in the noise spectrum in phase quadrature of resonance fluorescence from a three-level A atom is suggested. We add a microwave field to the lower energy states in the three-level A atom localization scheme, and form a three-level loop atom system. When spontaneous emission photons are detected, by changing the relative phase between the three nonresonant fields, the atom is located in one of two half wavelengths, so the probability of atomic localization is 50%. We also see that the intensity and the detuning of the microwave field affect intensively localization probability. Compared with the scheme based on electromagnetically induced transparency, the detection probability of atoms in the sub wavelength range is only 25%, and the resonance condition is useless.

Analyzing from the micro level of the basic unit of environmental protection industry -- enterprise, this paper takes relevant information of more than 8000 key enterprises in China's environmental protection industry from 2018 to 2020 as the big data training samples, and uses BP neural network method to identify the key production factors that have great impact on the output of the whole China's environmental protection industry and its main subdivisions. The results show that China's environmental protection industry is still in the growing stage in the current stage, with significant capital pulling, technological innovation driving, and management innovation also plays an important role. There are differences in the performance of water, air and solid waste in the environmental protection industry. In detail, R&D expenses from the government plays the most important role in water pollution prevention and control industry. Technology innovation plays the most important role in air pollution prevention and control industry. And staff play the most important role in solid waste treatment and resource recycling industry.

Front surface texturing is a common method used to improve the optical performance of photovoltaic devices. However, traditional texturing techniques may be challenging in some cases, such as when dealing with ultra-thin substrates. Textured polymer films on such devices would be an alternative approach. This paper reports a study of NOA81 thin films with a bionic lotus leaf surface structure on monocrystalline silicon solar cells. Inspired by the surface structure of natural lotus leaves, we successfully prepared a bionic lotus leaf microstructure film on the surface of solar cells based on NOA81 using polydimethylsiloxane (PDMS) polymer and nanoimprinting methods. Scanning electron microscopy (SEM) images showed that the surface structure of the NOA81 thin film was the same as that of natural lotus leaves. A UV-Vis spectrophotometer with an integrating sphere was used to measure the reflectance of the textured NOA81 film on the silicon wafer. Results showed that the textured NOA81 film could effectively reduce the reflectance of the silicon wafer surface. We also used finite-difference time-domain (FDTD) simulation to verify this conclusion further. Finally, the I-V characteristics of the prepared solar cells with the textured NOA81 film were investigated, and the highest photovoltaic efficiency was measured to be about 16.07%, effectively improving the photoelectric conversion efficiency. In addition, the film with textured NOA81 can be used as a protective film for monocrystalline silicon solar cells.

Enhancing boundary slip using interfacial nanobubbles (INBs) has gained significant interest in nanofluidic transport. In this study, we conducted a comprehensive investigation on the influence of INBs on boundary conditions for both smooth and rough substrates using molecular dynamics simulations. We analyzed the impact of INB protrusion angle, coverage percentage, quantity, and fluidity on the slip length. Our results showed that INBs always increase the slip length on a smooth substrate, with a linear increase in slip length observed with increasing surface coverage. On a rough substrate, we found that the protrusion angle, quantity, and fluidity of INBs play a crucial role in determining the slip length. Smaller protrusion angles and fewer quantities of INBs were found to be more favorable for enhancing the slip length when the INB coverage is fixed, while the correlation between boundary slip and INB quantity depended on the wetting state of the substrate when the size of the INBs was fixed with a low protrusion angle. Additionally, we revealed that the fluidity of gas molecules inside the INBs dominated the enhancement of slip length by INBs. Overall, our findings are expected to provide valuable insight into drag reduction based on INBs.

Supraparticles are large clusters of much smaller colloidal particles. Controlling the shape and anisotropy of supraparticles can enhance their functionality, enabling applications in fields such as optics, magnetics, and medicine. The evaporation of self-lubricating colloidal ouzo droplets is an easy and efficient strategy to create supraparticles, overcoming the problem of the “coffee-stain effect” during drop evaporation. Yet, the parameters that control the shape of the supraparticles formed in such evaporating droplets are not fully understood. Here, we show that the size of the colloidal particles determines the shape of the supraparticle. We compared the shape of the supraparticles made of seven different sizes of spherical silica particles, namely from 20 to 1000 nm, and of the mixtures of small and large colloidal particles at different mixing ratios. Specifically, our in situ measurements revealed that the supraparticle formation proceeds via the formation of a flexible shell of colloidal particles at the rapidly moving interfaces of the evaporating droplet. The time tc0 when the shell ceases to shrink and loses its flexibility is closely related to the size of particles. A lower tc0, as observed for smaller colloidal particles, leads to a flat pancake-like supraparticle, in contrast to a more curved American football-like supraparticle from larger colloidal particles. Furthermore, using a mixture of large and small colloidal particles, we obtained supraparticles that display a spatial variation in particle distribution, with small colloids forming the outer surface of the supraparticle. Our findings provide a guideline for controlling the supraparticle shape and the spatial distribution of the colloidal particles in supraparticles by simply self-lubricating ternary drops filled with colloidal particles.

Microbubble-assisted technologies have been widely used in mineral flotation and oil–water separation, among many other industrial processes. This work compares the effects of temperature and air s...

Cleaner analytic technique for quantifying compounds in dense suspension is needed for wastewater and environment analysis, chemical or bio-conversion process monitoring, biomedical diagnostics, food quality control among others. In this work, we introduce a green, fast, one-step method called nanoextraction for extraction and detection of target analytes from sub-milliliter dense suspensions using surface nanodroplets without toxic solvents and pre-removal of the solid contents. With nanoextraction, we achieve a limit of detection (LOD) of 10^(-9) M for a fluorescent model analyte obtained from a particle suspension sample. The LOD lower than that in water without particles 10^(-8) M, potentially due to the interaction of particles and the analyte. The high particle concentration in the suspension sample thus does not reduce the extraction efficiency, although the extraction process was slowed down up to 5 min. As proof of principle, we demonstrate the nanoextraction for quantification of model compounds in wastewater slurry containing 30 wt% sands and oily components (i.e. heavy oils). The nanoextraction and detection technology developed in this work may be used as fast analytic technologies for complex slurry samples in environment industrial waste, or in biomedical diagnostics., This is an unedited, original author's version of the manuscript

In this paper, microlens array (MLA) templates with high filling factors were prepared by combining a thermal reflow method and parylene chemical vapor deposition (CVD). Then photoresist MLAs were replicated from the MLA templates by using ultraviolet nanoimprint technology. The surface morphology of the replicated photoresist MLAs was characterized by scanning an electron microscope and optical microscope. Results show that the photoresist MLAs have a relatively smooth surface, and the filling factor has been improved obviously. Also, the surface profiles of the MLAs were measured. The optical imaging properties of the MLAs were also characterized, and they had a relatively good imaging performance. Finally, the photoresist MLAs were applied on organic LEDs (OLEDs), and their luminance and current efficiencies were measured. Results show that the current efficiency of the OLEDs increased by about 42.41%, 29.01%, and 35.51%, respectively, for OLEDs with circular, hexagonal, and square MLAs. All the results above indicate that it is a simple and effective process to prepare MLA templates with high filling factors by combining thermal reflow and CVD techniques, and the prepared photoresist MLAs have great application potential in OLED areas.

Light trapping micro-nano structures have been widely used to optimize the function of solar cell devices, especially microlens arrays (MLAs). In this article, we first prepared composite films by using sol-gel technology and the spin coating method, and then constructed heteromorphic MLAs on the surface of the composite films by using thermal reflow and UV nanoimprint technology; the substrate used was the silicon solar cell. Finally, the performance of the cells was improved. Optical transmission properties and surface morphology of the organic–inorganic hybrid films were detected by using a UV-Vis spectrometer and atomic force microscopy, respectively; it was revealed that the hybrid films had relatively excellent optical transmission performance in the visible light range. Surface structure of the hybrid film MLAs were detected by using SEM. At the same time, the optical imaging capabilities of MLAs were studied by using optical microscopy. Besides, the contact angles of the MLAs were also measured. It can be clearly seen that the prepared MLAs have a regular arrangement, clean appearance, and good imaging capabilities (from the actual test results). Finally, the various parameters of the silicon solar cells with hybrid film MLAs were studied. In addition, the power conversion efficiency (PCE) values increased by about 10.48% for the silicon solar cell with circular MLAs, compared to the silicon solar cell without a structure. The results show a concise and effective method to prepare organic–inorganic hybrid film MLAs on silicon solar cells, with significant improvement in photoelectric conversion efficiency.

Oil sands adhered on truck bed reduce transport capacity of the truck, require manual cleaning, and create hurdles for automated surface mining. Study on the adhesion properties of oil sands to solid substrates is important to minimize the fouling of substrates during mining operation. In this work, we study the influence of hydrophobicity and mechanical properties of the substrates on the adhesion strength of frozen oil sands. By using an adhesion force apparatus with temperature control, we measure the adhesion strength of both ice and frozen oil sands on six types of substrates with water contact angle from ∼20◦ to ∼130◦ and Young’s modulus from a few MPa to 300 GPa. A clear linear correlation between the adhesion strength of pure ice and that of frozen oil sands is observed. Furthermore, the adhesion strength increases with the load on the oil sands sample and reaches a plateau at ∼450 kPa. The maximum adhesion strength may be due to the limit of particle packing of oil sands. We also demonstrate that spray coating of anti-freezing liquids is effective for the mitigation of the adhesion of frozen oil sands. Substrates coated with various anti-freezing liquids showed undetectable oil sands adhesion strength at -20 ◦C with 0.06 MPa of load. The study on oil sands adhesion and potential fouling mitigation method may provide a potential solution to industries looking to reduce fouling of surfaces by frozen granular matter.

The recovery of valuables from industrial wastewater prior to release to the environment is indispensable to comply with ever pressing economic and environmental imperatives. In this work, microbub...

Traumatic brain injury (TBI) is a health problem of global concern because of its serious adverse effects on public health and social economy. A technique that can be used to precisely detect TBI is highly demanded. Here, we report on a synchrotron radiation-based Fourier transform infrared (SR-FTIR) microspectroscopic imaging technique that can be exploited to identify TBI-induced injury by examining model mouse brain tissue slices. The samples were first examined by conventional histopathological techniques including hematoxylin and eosin (H&E) staining and 2,3,5-triphenyltetrazolium chloride staining and then spectroscopically imaged by SR-FTIR. SR-FTIR results show that the contents of protein and nucleic acid in the injured region are lower than their counterparts in the normal region. The injured and normal regions can be unambiguously distinguished from each other by the principle component analysis of the SR-FTIR spectral data corresponding to protein or nucleic acid. The images built from the spectral data of protein or nucleic acid clearly present the injured region of the brain tissue, which is in good agreement with the H&E staining image and optical image of the sample. Given the label-free and fingerprint features, the demonstrated method suggests potential application of SR-FTIR spectroscopic mapping for the digital and intelligent diagnosis of TBI by providing spatial and chemical information of the sample simultaneously.

A combinative approach for chemical analysis makes it possible to distinguish a mixture of a large number of compounds from other mixtures in a single step. This work demonstrates a combinative analysis approach using surface nanodroplets for integrating nanoextraction and colorimetric reactions for the identification of multicomponent mixtures. The model analytes are acidic compounds dissolved in an oil that are extracted into aqueous droplets on a solid substrate. The proton from acid dissociation reacts with the halochromic chemical compounds inside the droplets, leading to the color change of the droplets. The rate of the colorimetric reaction exhibits certain specificity for the acid type, distinguishing acid mixtures with the same pH value. The underlying principle is that the acid transport rate is associated with the partition coefficient and the dissociation constant of the acid, as well as to the concentration in the oil. As a demonstration, we showed that droplet-based combinative analysis can be applied for anti-counterfeiting of various alcoholic spirits by comparing the decoloration time of organic acid mixtures in the spirits. The readout can be done by a common hand-hold mobile phone.

Droplets abound in nature and technology. In general, they are multicomponent, and, when out of equilibrium, have gradients in concentration, implying flow and mass transport. Moreover, phase transitions can occur, in the form of evaporation, solidification, dissolution or nucleation of a new phase. The droplets and their surrounding liquid can be binary, ternary or contain even more components, with several in different phases. Since the early 2000s, rapid advances in experimental and numerical fluid dynamical techniques have enabled major progress in our understanding of the physicochemical hydrodynamics of such droplets, further narrowing the gap from fluid dynamics to chemical engineering and colloid and interfacial science, arriving at a quantitative understanding of multicomponent and multiphase droplet systems far from equilibrium, and aiming towards a one-to-one comparison between experiments and theory or numerics. This Perspective discusses examples of the physicochemical hydrodynamics of droplet systems far from equilibrium and the relevance of such systems for applications. Droplets in general are multicomponent and experience gradients in concentration, often leading to transport phenomena and phase transitions. This Perspective discusses recent progress on the physicochemical hydrodynamics of such droplet systems and their relevance for many important applications.

This study systematically investigated the phytotoxicity of chicken manure co-composted with tobacco powder and mushroom substrate on seed germination during active phase of composting. All compost products met the sanitation requirements specified in the Chinese national standard; however, only the mushroom substrate compost satisfied the maturity standard. From day 28, the composting entered the end of active phase and the concentrations of K+, Zn2+, Na+, Cu2+ and Fe3+ decreased gradually. Redundancy analysis indicated that the germination index, catalase and peroxidase activities was positively correlated with K+, Zn2+, Na+, Cu2+, Fe3+ and NO3--N, and negatively correlated with NH4+-N, Mg2+ and Ca2+, among which the most significant ions were Fe3+, Mg2+ and Zn2+ for all treatments. The malondialdehyde concentration of germinated seeds had adverse correlation with the above ions parameters.

The compartmentalization of chemical reactions within droplets has advantages in low costs, reduced consumption of reagents, and increased throughput. Reactions in small droplets have also been shown to greatly accelerate the rate of many chemical reactions. The accelerated growth rate of nanobubbles from nanodroplet reactions is demonstrated in this work. The gaseous products from the reaction at the nanodroplet surface promoted nucleation of hydrogen nanobubbles within multiple organic liquid nanodroplets. The nanobubbles were confined within the droplets and selectively grew and collapsed at the droplet perimeter, as visualized by microscopy with high spatial and temporal resolutions. The growth rate of the bubbles was significantly accelerated within small droplets and scaled inversely with droplet radius. The acceleration was attributed to confinement from the droplet volume and effect from the surface area on the interfacial chemical reaction for gas production. The results of this study provide further understanding for applications in droplet enhanced production of nanobubbles and the on-demand liberation of hydrogen.

In this study, we investigate the impact of global economic policy uncertainty (GEPU) on Chinese stock market volatility. More importantly, for the first time, we explore the effects of directional GEPU based on the changing directions of GEPU and Chinese economic policy uncertainty (EPU). We make several noteworthy findings. First, the in-sample estimated results show that up and down GEPU can lead to substantially high stock market volatility for China. Second, the out-of-sample estimated results support the contention that the GEPU index is helpful for predicting volatility. Moreover, compared to GEPU alone, directional GEPU can provide more useful information that can increase the forecast accuracy. Third, we empirically find that directional GEPU is more effective in predicting Chinese stock market volatility when GEPU and EPU rise in the same month.

To understand the unexpected and puzzling long-term stability of nanoscale gas bubbles, it is crucial to probe their nature and intrinsic properties. We report herein synchrotron-based scanning transmission X-ray microscopy (STXM) evidence of highly condensed oxygen gas molecules trapped as surface nanobubbles. Remarkably, the analysis of absorption spectra of a single nanobubble revealed that the oxygen density inside was 1-2 orders of magnitude higher than that in atmospheric pressure, and these bubbles were found in a highly saturated liquid environment with the estimated oxygen concentration to be hundreds of times higher than the known oxygen solubility in equilibrium. Molecular dynamics simulations were performed to investigate the stability of surface nanobubbles on a heterogeneous substrate in gas-oversaturated water. These results indicated that gas molecules within confinement such as the nanobubbles could maintain a dense state instead of the ideal gas state, as long as their surrounding liquid is supersaturated. Our findings should help explain the surprisingly long lifetime of the nanobubbles and shed light on nanoscale gas aggregation behaviors.

We present a curious effect observed during the dissolution process of water-immersed long-chain alcohol drops with an entrapped air bubble. These droplets dissolve while entrapping an air bubble pinned at the substrate. We qualitatively describe and explain four different phases that are found during the dissolution of this kind of system. The dissolution rate in the four phases differ dramatically. When the drop-water interface and the air bubble contact each other, rapid cyclic changes of the morphology are found: The breakage of the thin alcohol layer in between the bubble and the water leads to the formation of a three phase contact line. If the surface tension of the water-air interface supersedes those of the alcohol-water and alcohol-air interfaces, alcohol from the droplet is pulled upwards, leading to a closure of the air-water interface and the formation of a new thin alcohol film, which then dissolves again, leading to a repetition of the series of events. We call this sequence of events Marangoni puffing. This only happen for alcohols of appropriate surface tension. The Marangoni puffing is an intermediate state. In the final dissolution phases the Marangoni forces dramatically accelerate the dissolution rate, which then becomes one order of magnitude faster than the purely buoyancy-convective driven dissolution. Our results have bearing on various dissolution processes in multicomponent droplet systems.

The electrocatalytic CO2 reduction to yield C2 products is of particular interest in solar-to-fuel conversion schemes. The nanocrystalline oxide derived copper (ODCu) electrodes are specifically attractive due to their high faradaic efficiency towards C2 hydrocarbons like ethylene, ethane, acetate and ethanol. However, the mechanistic understanding of this special selectivity is still an impediment. In this work, ODCu is obtained from Cu2O nanowires and employed for electrocatalytic CO2 reduction, during which ethylene is found to be the major product with a faradaic efficiency of 65% at -0.8 V (vs. RHE). By in situ photoresponse measurement, combined with the ex situ structure and composition analysis, Cu2O is demonstrated to be persistent on the surface of ODCu throughout the CO2 reduction reaction (CO2RR) even at high applied bias (-1.0 V vs. RHE), while Cu2O is not present on the bulk Cu foil. Density functional theory calculations are employed to further investigate the correlation between the surface Cu2O on ODCu and its C2 selectivity performance, which is attributed to the orbital interactions between the persistent oxide and CO2 reduction intermediates. It should be noted that uncovering the active sites is the initial step to understand the surface reaction chemistry in CO2RR; here, we propose that the presence of Cu2O is the key for C2 selectivity during CO2RR in the ODCu system, which may facilitate the development of highly efficient catalysts.

Poly (methyl methacrylate) (PMMA)-doped organic-inorganic composite films are prepared on flexible substrates through a combination of the sol-gel technique and the spin-coating method. Circular and hexagonal microlens arrays (MLAs) are then built into the composite films by using ultraviolet nanoimprint technology. Atomic force microscope and ultraviolet spectrophotometer characterization results of the films show that the films have low surface roughness and good optical transmittance. A scanning electron microscope is used to observe the surface morphology of the MLAs, and the results show that the prepared MLAs are regular and neat. The surface profiles of the MLAs are also measured by using a surface profiler. Optical microscopy results show that the prepared MLAs have good optical imaging properties. Finally, the MLAs are applied on the green organic light-emitting diodes (OLEDs), and the influence of the shape and diameter of the MLAs on the luminance and current efficiency of the OLEDs is discussed. Results indicate that there is a relatively high enhancement of the current efficiency and luminance for the OLEDs with hexagonal MLAs and a single microlens height of 9 µm, where the luminance can reach 10611 c d / c m 2 , and the current efficiency can be enhanced by about 20.1%. Furthermore, there is a higher enhancement of the luminance and current efficiency for the OLEDs with PMMA-doped MLAs than that of the OLEDs with no PMMA-doped MLAs. Based on these results, we believe that the obtained PMMA-doped composite film MLAs on flexible substrates have important applications in the flexible OLEDs displays areas.

The dissolution or growth of a droplet in a host liquid is an important part for processes like chemical extraction, chromatography or emulsification. In this work we look at the dissolution of a pair of vertically aligned droplets immersed in water, both experimentally and with numerical simulations. The liquids used for the droplets are long chain alcohols with a low but finite solubility in water and a significantly lower density than that of the host liquid. Therefore, a solutal plume is formed above of the bottom droplet and natural convection dominates the dissolution process. We monitor the volume of the droplets and the velocity field around them over time. When the liquids of the two droplets are the same, our previously found scaling laws for the Sherwood and Reynolds numbers as functions of the Rayleigh number (Dietrich et al., 2016, J. Fluid Mech.) can be applied to the lower droplet. However, remarkably, when the liquid of the top droplet is different than that of the bottom droplet the volume as function of time becomes non-monotonic, and an oscillatory Marangoni flow at the top droplet is observed. We identify the competition between solutal Marangoni flow and density driven convection as the origin of the oscillation, and numerically model the process., 29 pages, 8 figures

Osthole, a coumarin compound derived from Fructus Cnidii, exerts anti-inflammatory effects in an asthma model. But the effect of osthole on epithelial injury and epithelial-mesenchymal transition (EMT) in asthma remains unclear. 16HBE cells were incubated with TGF-β1 with or without osthole in vitro. Ovalbumin (OVA)-induced asthmatic mouse model was established in vivo. Cell counting kit-8 was carried out to evaluate the viability of 16HBE cells. The impact of osthole on TGF-β1-evoked cell apoptosis and EMT process was measured by flow cytometry based on Annexin V-FITC/PI staining, transwell assay, immunofluorescence, and Western blot. The regulatory role of osthole in TGF-β1/Smad and p38, ERK1/2, and JNK MAPK signaling was detected via Western blot. Osthole treatment significantly suppressed TGF-β1-induced 16HBE cell apoptosis, verified by a reduced percentage of apoptotic cells, decreased expression of proapoptotic proteins (cleaved-caspase3 and Bax), and enhanced antiapoptotic factor (Bcl-2) expression. In addition, the promotive impact of TGF-β1 on the migration of 16HBE cells was reversed by osthole, accompanied by elevated E-cadherin expression and reduced Snail and N-cadherin expression. The activation of the Smad2/3 and MAPKs pathway evoked by TGF-β1 was inhibited by osthole in 16HBE cells. We also found that osthole mitigated airway epithelium injury and subepithelial fibrosis in OVA-challenged asthmatic mice in vivo. Osthole could mitigate TGF-β1-induced epithelial cell injury and EMT process by suppressing the activation of MAPK and Smad2/3 pathways separately. Our present study showed a new insight into understanding the underlying mechanism of osthole injury on epithelium injury and subepithelial fibrosis in airway remodeling. Asthma, epithelial injury, epithelial-mesenchymal transition, and airway remodeling are the effects of osthole on airway remodeling.

As the most complex and heaviest component in bitumen, asphaltene precipitation induced by solvent dilution is important in oil sands extraction to remove solids and water from bitumen froth through dilution by paraffinic solvents. This review will compare asphaltene precipitation to dilution-induced solvent shifting in aqueous systems via the ouzo effect. We attempt to highlight similarities and differences in the evolution of nanodroplets and effects from solvent mixing conditions and point out mutual experimental techniques and modeling approaches for the research of both asphaltene precipitation and nanodroplet formation. The review will start from basic concepts in both asphaltene precipitation and the ouzo effect, then move on to the effects of solvent mixing on asphaltene precipitation in bulk. After that, we will introduce advances in microfluidic systems combined with cutting-edge experimental and simulation tools for asphaltene precipitation induced under controlled mixing with solvents and a droplet formation. Such comparison will inspire more in-depth understanding and control of asphaltene precipitation and the ouzo effect in aqueous systems., Comment: 32 Pages, 12 Figures

Bitumen residues in the oil sand tailings can be a threat to the environment that separating them from tailings before disposal is crucial. However, low bitumen concentration in the tailings slurry and the complex transport characteristics of the four-phase mixture make the process difficult. This study establishes an Eulerian-Eulerian CFD model for an industrial-scale oil sand tailings pipeline. A comprehensive sensitivity analysis was conducted on the selection of carrier-solid and solid-bitumen drag models. The combination of small and large particle sizes (i.e., 75 & 700 um) and bitumen droplet size (i.e., 400 um) provided good agreement with field data in velocity profiles and pressure drop. The validated model was subsequently extended to investigate the influence of the secondary phase (i.e., bitumen droplets and bubbles) on flow characteristics in a tailing pipeline. The investigation covered a range of bitumen droplet size (100-400 um), bitumen fraction (0.0025-0.1), bubble size (5-1000 um), and bubble fraction (0.0025-0.3) and their influences on the velocity, solids, and bitumen distribution are revealed. For an optimum bubble size of 500 um, a maximum recovery of 59% from the top 50 % and 83 % from the top 75 % of the pipe cross-section was obtained. The present study demonstrates the preferential distribution of bitumen and provides valuable insight on bitumen recovery from an industrial-scale tailings pipeline., 51, 14 figures

The intrusion detection system is designed to discover the abnormal behavior of the network system, but it has the problems of low detection accuracy, inability to perform fine detection, and huge time cost. Therefore, it is necessary to design a fast and accurate intrusion detection system. Therefore, this paper proposes a multigranularity feature generation + XGBOOST method to improve the intrusion detection system. First, we propose a multigranularity feature generation algorithm, which converts all features into discrete features with different numbers of categories. Different numbers of categories represent different granularities. We believe that the combination of multiple different granular features can achieve better accurate attack detection. Then, we use the proposed method to perform experimental verification on the four datasets of KDD99, NSL-KDD, UNSW_NB15, and CSE-CIC-IDS2018. For the KDD99 dataset, detection rates of 100%, 100%, and 99.43% can be achieved in the two-category, five-category, and multicategory tasks, respectively; for the NSL-KDD dataset, detection rates of 100%, 100%, and 90.84% can be achieved in the two-category, five-category, and multicategory tasks, respectively; for the UNSW_NB15 dataset, 100% detection rate can be achieved in the second and tenth categories; for the CSE-CIC-IDS2018 dataset, 100% detection rate can be achieved in the third classification. Experiments show that the proposed algorithm can achieve accurate and precise detection. Finally, we experiment with the multigranularity feature generation algorithm on multiple classifiers and multiple datasets to prove the generalization ability of the proposed feature generation algorithm and compare the proposed algorithm with the CFS algorithm to prove the efficiency of the algorithm.

Photocatalysis is one of the dominant technologies used to enhance the efficiency of water decontamination with light-based treatments. However, the effectiveness of photocatalysts is usually limited by the irradiation conditions and the properties of the water matrix. In this work, we have demonstrated the capability of surface microlenses (MLs) as a clean technology for more efficient photocatalytic water decontamination. Random or ordered surface MLs were fabricated from simple polymerization of nanodroplets produced in a solvent exchange process. Both random microlenses (MLR) and microlenses array (MLA) could enhance the photocatalytic degradation efficiency of four representative pollutants, including methyl orange (MO), norfloxacin (NFX), sulfadiazine (SFD), sulfamethoxazole (SMX), spiked in ultra-pure water, synthetic natural water, or real river water. By controlling the conditions of light treatment, the photodegradation efficiency could be enhanced by up to 402%. The effectiveness of surface MLs was validated under both visible LED light and simulated solar light and for two photocatalysts zinc oxide (ZnO) and titanium dioxide (TiO2). By reducing the concentration of the photocatalysts from 100 to 5 mg/L and the intensity of irradiation intensity from 1 Sun to 0.3 Sun, our findings suggest that the enhancement factor by MLs was higher at lower catalyst concentration, or at lower light intensity. Based on optical simulations and experimental results, we demonstrated that surface MLs optimize the light distribution and promote the formation of active species, which results in the enhancement of degradation efficiency. The use of MLs may serve as a novel strategy to improve the photocatalytic degradation of micropollutants, especially in places where the available light source is weak, such as indoors or in cloudy regions.

We investigated the effect of top contact interface and microstructural characteristics of the insulating layers on resistive switching behaviors by fabricating and characterizing the HfO

Using China's A-share listed companies from 2018 to 2020, this paper examines the impact of COVID-19 on earnings management. The results reveal that: (1) The COVID-19 shock intensifies earnings management, which is reflected in the increasing accrual-based earnings management and real earnings management. Moreover, when enterprises face a higher degree of financial constraints, this shock effect is more evident. (2) Enterprises in industries and regions where COVID-19 is more severe are more affected by the suspension of work and production caused by the epidemic prevention policies, so these enterprises choose accrual-based earnings management through accounting items rather than carrying out earnings management through real activities. (3) Further analysis finds that, enterprises with more investment opportunities have more evident earnings management caused by the COVID-19 shock. However, high-quality auditing has an inhibitory effect on accrual-based earnings management caused by the COVID-19 shock but has no inhibitory effect on real earnings management.

Osthole, a coumarin compound derived from Fructus Cnidii, exerts anti-inflammatory effects in an asthma model. But the effect of osthole on epithelial injury and epithelial-mesenchymal transition (EMT) in asthma remains unclear. 16HBE cells were incubated with TGF

Surface-bound nanomaterials are widely used in clean energy techniques from lithium batteries, solar-driven evaporation in desalination to hydrogen production by photocatalytic electrolysis. Reactive surface nanodroplets may potentially streamline the process of fabrication of a range of surface-bound nanomaterials invoking biphasic reactions at interfaces. In this work, we demonstrate the feasibility of reactive surface nanodroplets for in-situ synthesis and anchoring of nanocaps of metal oxides with tailored porous structures. Spatial arrangement and surface coverage of nanocaps are predetermined during the formation of reactive nanodroplets, while the crystalline structures of metal oxides can be controlled by thermal treatment of organometallic nanodroplets produced from the biphasic reactions. Notably, tuning the ratio of reactive and non-reactive components in surface nanodroplets enables the formation of porous nanocaps that can double photocatalytic efficiency in the degradation of organic contaminants in water, compared to smooth nanocaps. In total, we demonstrate in-situ fabrication of four types of metal oxides in the shape of nanocaps. Our work shows that reactive surface nanodroplets may open a door to a general, fast and tuneable route for preparing surface-bound metal oxides. This fabrication approach may help develop new nanomaterials needed for photocatalytic reactions, wastewater treatment, optical focusing, solar energy conversion and other clean energy techniques.

Silicon solar cells have the advantages of non-toxicity, reliability, low price, and stability. Microlens arrays (MLAs) are widely used in solar cells to improve photoelectrical conversion efficiency (PCE). In this research, different MLAs mold was designed by a method of thermal reflow. Then the photoresist film MLAs structure was replicated on the surface of silicon solar cells through UV nanoimprint technology. The optical transmission and surface morphology of these photoresist films were respectively measured by using a UV spectrometer and an atomic force microscope. The surface morphology and imaging capabilities of photoresist film MLAs were respectively measured by using a scanning electron microscope and optical microscope. Finally, the photovoltaic performance of the silicon solar cell with the photoresist film MLAs was investigated, and the PCE value of the silicon solar cell improved from 11.53% for the sample without MLAs to 13.19% for the sample with the square MLAs and the PCE improvement is about 14.40%. All these results above show that the photoresist film MLAs can significantly improve the efficiency of silicon solar cells and have great application potential in the field of solar cells.

Background Studies have proved that the enhanced recovery after surgery (ERAS) protocol can significantly improve the recovery course of patients during the perioperative period. The application of minimally invasive surgery is a critical component of ERAS protocol. Single-incision plus one port laparoscopic surgery (SILS plus one) could achieve further minimally invasive surgical results than conventional laparoscopic surgery (CLS). The objective of this trial is to evaluate the safety and feasibility of SILS plus one with ERAS protocol in colorectal cancer. Methods This is a prospective, single-center, open-label, single-arm trial. A total of 120 eligible patients with colorectal cancer will receive SILS plus one followed by the ERAS management during the perioperative period. The primary endpoint is postoperative hospital stay. The secondary endpoints include rehabilitative rate of the fourth postoperative day, postoperative medical cost, postoperative pain score, postoperative recovery indexes, inflammatory immune response indexes, compliance with ERAS measures, 6 min postoperative walking test (6MWT), hospital readmissions, and early postoperative complications. Discussion This trial will be the first to evaluate the short-term outcomes of SILS plus one assisted with ERAS protocol for patients with colorectal cancer and will provide valuable clinical evidence on the benefit of the combination of these two techniques, hopefully, to provide patients with more safe, economic, feasible, and rapid surgery and perioperative strategies. Trial Registration Clinical Trial Registry, NCT0426829. Registered February 15, 2020 (https://clinicaltrials.gov/ct2/show/NCT04268290).

Plasmonic nanobubbles are bubbles that are formed from local heat generated by noble metal nanoparticles under illumination of light at resonance. Understanding the formation and behavior of plasmo...

Photoelectrochemical reduction of CO2 is an efficient way to overcome the limited supply of fossil fuels and mitigate the greenhouse effect, as well as produce carbonaceous fuels from the sunlight. CuBi2O4 is a p-type semiconductor with conduction band potential negative enough for CO2 reduction. Nanoporous CuBi2O4 photocathodes are prepared by electrodeposition with subsequent annealing and are comprised of well-crystallized nanoparticles, which exhibit good visible-light response. The film thickness can be adjusted readily by changing the deposition time. The charge behavior in the CuBi2O4 photocathodes and its relationship with the film thickness are thoroughly investigated by using photocurrent and intensity modulated photocurrent spectroscopy. It is found that CuBi2O4-4 min possesses the optimized charge generation and transfer performance, and shows the highest activity with CO as the only product of photoelectrochemical reduction of CO2 under 0 V vs Ag/AgCl. The results indicate that CuBi2O4 can be a promising photocathode for CO2 photoelectrochemical reduction under low bias.

Poly(9-vinylcarbazole) (PVK) was introduced to modify the interface of perovskite/PCBM. The modified PVK material can induce the formation of the quasi-continuous sheet-shaped perovskite film at the surface of 3D perovskite layer, which may reduce the exposed grain boundaries. Besides, the PVK modified perovskite layer can reduce carrier recombination and accumulation at the interface of perovskite/PCBM and improve the crystallinity of perovskite layer and the interface contact properties. The PVK modification can greatly improve the PCEs and thermal and moisture stability and suppress the J-V hysteresis of perovskite solar cells (PSCs). PSCs with PVK modification achieved champion PCE of 19.03% (average PCE of 18.40%), maintained 80% of the original PCE value aging for 50 days under ambient conduction without encapsulation. Furthermore, PSCs with PVK modification can maintain 87% of the origin PCEs aging for 3 h under 85 °C thermal stress, which are greatly higher than that (26%) of PSCs without PVK modification.

The oil-water partition coefficient of organic compounds is an essential parameter for the determination of their behaviors in environments, food, drug delivery, and biomedical systems, just to name a few. In this work, we establish a highly efficient approach to quantify the partition/distribution coefficient using surface femtoliter droplets. In our approach, droplets of 1-octanol were produced on the surface of a solid substrate in contact with the flow of an aqueous solution of the analyte. The analyte was rapidly enriched in the droplets from the flow and reached the partition equilibrium in a few seconds. The entire procedure was automated by continuous solvent exchange, and the analyte partition in the droplets was quantified from the in situ UV-vis spectrum collected by a microspectrophotometer. Our approach was validated for several substances with the octanol-water partition/distribution coefficient ranging from -1.5 to 4, where our results were in good agreement with the values reported in the literature. This method took ∼3 min to detect one analyte with the volume of the organic solvent at ∼50 μL. Thus, our surface droplet platform can greatly minimize the consumption of both solvent and analytes and can shorten the time for the determination of the partition of new compounds, which overcomes the drawbacks of the traditional shake-flask method and presents excellent reproducibility, high accuracy, cost-effectiveness, and labor-saving operation. The highly efficient micro/nanoextraction, partition, and real-time detection enabled by the surface droplets has the potential for many other high-throughput applications.