Search

Hydrogen (H2) has been demonstrated to be highly effective in combating drug-resistant Staphylococcus aureus by breaking the redox homeostasis of bacterial metabolism and down-regulating expression of many drug-resistant genes like fmtA, gpsB, etc.

Typhoons are the main cause of disturbances in the natural environment of coastal cities. Typhoons often damage the urban green space (UGS) of coastal cities, and the spatial pattern of such damages provides important information for disaster recovery. For acquiring such information, remote sensing technology offers a fast and effective means. This study investigated the spatial pattern of typhoon damage to UGS using Sentinel-2 data. To this end, the damage caused by Typhoon Meranti to the UGS of Xiamen Island (including Gulangyu Island) in 2016 was taken as a case study. The results showed that the overall area without vegetation coverage increased by 1159.7 ha. Areas with high vegetation coverage experienced less damage than areas with low vegetation coverage. A coldspot map of damage clusters was generated, and the map showed that severely damaged green areas were distributed in a striped pattern, indicating serious damage to road greening. In terms of direction, east-west roads experienced a higher degree of damage than north-south roads. The determined spatial pattern of the damage caused by Typhoon Meranti on the UGS of Xiamen Island provides a basis for the post-disaster restoration of the landscape of Xiamen Island.

Based on the Direct Simulation Monte Carlo (DSMC) method, an unsteady flow, which is caused by the interaction of two counter-flow jets with a hypersonic free stream, is constructed and simulated in the rarefied regime for the flight altitude of 90 km. In this complex three-dimensional rarefied flow, although the hypersonic free stream and all counter-flow jets are stable, their interaction area has great instability. This signifies that this extensive interaction area will not reach a final stable state in the DSMC simulation process. This study exhibits the unsteady evolution of the interaction area.

With the help of deep learning technology, related topics of natural language processing such as summarization, text classification, and sentiment analysis, are researched deeper and deeper. However, related benchmarks especially for Chinese language are in short. For this reason, we propose a novel Chinese news text benchmark called Open Text News benchmark (OTN) enhancing related research in natural language processing. OTNSTANDARD contains 90,000 Chinese news from April 2000 to June 2021 in nine categories, including finance, estate, education, technology, military, automobiles, sports, games, and entertainment. We employed several classical machine learning classifiers and several deep learning models to test our OTN benchmark to see how well it performed at text classification.

In the present study, Landsat series remote sensing image are utilized to investigate the spatial and temporal changes of the urban heat island (UHI) in the Taiyuan city from 1990, 2004 and 2014. The main influencing factors of the UHI are analyzed in this regard. The single window algorithm is adopted to invert the land surface temperature (LST) from the thermal infrared data and analyze the spatiotemporal pattern of the LST in the studied area. Then, the urban thermal field variance index (UTFVI), normalized difference vegetation index (NDVI) and biophysical composition index (BCI) are calculated in accordance with the LST. Moreover, the degree of impervious surface of the study area is divided according to the BCI value. By analyzing the correlation between the LST, NDVI and the BCI, the influences of two major factors, green space and impervious surface, on urban heat islands are discussed. It is found that the average surface temperature of the Taiyuan city has increased by 5.17 °C during the past 24 years from 1990 to 2014, while the impervious surface area has increased by 223.53 km2, which is 1.179 times of that in 1990. There is a statistical correlation between the LST and the data of the NDVI and impervious surface, which shows that the reduction in green space and the increase in impervious surface in the city have a significant impact on the urban heat island effect. As the largest city in Shanxi province, there is an increasing demand in Taiyuan city for constructing lands during the urbanization process, which has led to a remarkable decrease in the green space and an increase in impervious surfaces. Therefore, the LST in Taiyuan city has been affected by the rapid urbanization. Furthermore, UTFVI indicates that the overall ecological environment of the Taiyuan city has deteriorated and the area of high temperature in the city has increased significantly. Results of the present study may provide a scientific basis for government departments to formulate urban planning and environmental protection policies. The present study may help the government to expand urban green spaces in the right places, control the expansion of the impervious surface of the city, alleviate the UHI effect and maintain the sustainable development of the Taiyuan city.

Multivalent ion storage mechanism is applied to construct high-performance aqueous zinc-ion hybrid supercapacitors (ZHSs). The constructed MnO2 nanorods//activated carbon (AC) ZHSs with ZnSO4 aqueous electrolyte are significantly different from the common MnO2//AC asymmetric supercapacitors with Na2SO4 electrolyte in electrochemical behaviors and energy storage mechanism. The ZHSs show the maximum specific capacity of 54.1 mA h g−1 and maximum energy density of 34.8 W h kg−1 at the optimal mass ratio of AC to MnO2. The ZHSs are capable of being charged/discharged rapidly within only 2–17 s, delivering a large power of 3.3–13.0 kW kg−1. Reversible insertion/extraction of Zn2+ into/from MnO2 nanorods and ion adsorption/desorption on AC particle surface, as well as partially reversible formation/dissolution of Zn4(OH)6SO4·nH2O participates on both electrodes, are established as the energy storage mechanism of the ZHSs. Electrochemical performance of the ZHSs can be further optimized through electrolyte composition regulation. Addition of Mn2+ cations into ZnSO4 electrolyte leads to significantly enhanced energy density (58.6 W h kg−1) of the ZHSs, while anion replacement of SO42- by CF3SO3- suppresses manganese dissolution and Zn4(OH)6SO4·nH2O formation, thus resulting in good cycling stability with 93.4% capacity retention over 5000 charge/discharge cycles. Overall, the ZHSs based on multivalent ion storage are promising to be applied as high-performance, extremely safe and eco-friendly energy storage devices for wearable/portable electronics and hybrid electric vehicles.

Microwave-assisted pyrolysis of biomass with HZSM-5 coupled with SiC as microwave-absorbent in a downdraft reactor is a promising method for obtaining hydrocarbon-rich bio-oil. The hydrocarbon content limits the economic and commercial viability of the bio-oil produced by pyrolysis. In this study, the effects of catalytic temperature, feedstock-to-catalyst ratio, and WHSV on the yield and composition of bio-oil are studied. In addition, this study compared the influence of downdraft reaction and updraft reaction on the yield and composition of bio-oil. Furthermore, the stability of the catalyst is studied. Catalytic temperature and feedstock-to-catalyst ratio played pivotal roles in the yield and composition of bio-oil. WHSV has minimal influence on the bio-oil yield and composition within the scope of our research. Furthermore, the optimal catalytic temperature, feedstock-to-catalyst ratio and WHSV were 400 °C, 2:1, and 72 h−1, respectively. The results illustrated that the downdraft coupled with the microwave-absorbent was conducive to the formation of aromatic hydrocarbons. The HZSM-5 performed well in five replicate experimental cycles under optimal conditions in terms of bio-oil yield and aromatic hydrocarbon yield.

Hemophagocytic lymphohistiocytosis (HLH) is an immune-mediated disorder caused by uncontrolled inflammatory responses and the activation of T lymphocytes. This life-threatening disease, characterized by fever, cytopenia and hepatosplenomegaly, is extremely rare during pregnancy with high mortality. Despite the improvement of treatment regimen in recent years, HLH is still a great challenge for clinicians. Here, we described a 26-year-old woman who admitted to our hospital at her first pregnancy with pyrexia. Her condition continued to deteriorate after receiving broad-spectrum antimicrobials, presenting with fever, pancytopenia, hepatosplenomegaly, ferritin ≥ 500 μg/L, hemophagocytosis and low NK-cell activity. HLH was eventually diagnosed by clinical manifestation and laboratory examination results. Then the patient recovered well after treatment with etoposide combined with ruxolitinib therapy and underwent successful induced-labor operation. Additionally, we summarized similar cases from the literature to improve the management of HLH during pregnancy. In conclusion, this study highlights the challenges and difficulties in the diagnosis and management of patients with HLH during pregnancy. Moreover, this is the first case report of etoposide combined with ruxolitinib in the treatment of patients with refractory secondary HLH during pregnancy.

Deception is a crucial tool in the cyberdefence repertoire, enabling defenders to leverage their informational advantage to reduce the likelihood of successful attacks. One way deception can be employed is through obscuring, or masking, some of the information about how systems are configured, increasing attacker’s uncertainty about their targets. We present a novel game-theoretic model of the resulting defender-attacker interaction, where the defender chooses a subset of attributes to mask, while the attacker responds by choosing an exploit to execute. The strategies of both players have combinatorial structure with complex informational dependencies, and therefore even representing these strategies is not trivial. First, we show that the problem of computing an equilibrium of the resulting zero-sum defender-attacker game can be represented as a linear program with a combinatorial number of system configuration variables and constraints, and develop a constraint generation approach for solving this problem. Next, we present a novel highly scalable approach for approximately solving such games by representing the strategies of both players as neural networks. The key idea is to represent the defender’s mixed strategy using a deep neural network generator, and then using alternating gradient-descent-ascent algorithm, analogous to the training of Generative Adversarial Networks. Our experiments, as well as a case study, demonstrate the efficacy of the proposed approach.

Named Entity Recognition (NER) in the medical field targets to extract names of disease, surgery, and the organ location from medical texts, which is considered as the fundamental work for medical robots and intelligent diagnosis systems. It is very challenging to recognize the named entities in Chinese medical texts, because (a) one single Chinese medical named entity is usually expressed with more characters/words than other languages, i.e. 3.2 words and 7.3 characters in average; (b) different types of medical named entities are usually nested together. To address the above issue, this paper presents a neural framework that is constructed by two modules: a pre-trained module to distinguish each individual entity from the nested expressions, while a modified Bi-LSTM module to effectively identify long entities. We conducted the experiments based on the CCKS2019 dataset, our proposed method can identify the medical entity in Chinese, especially for those nested entities embodied in long expressions, and 95.83% was achieved in terms of F1-score, and 18.64% improvement was achieved compared to the baseline models.

Chemical swelling and electrochemical oxidation are combined to realize the separation and recovery of carbon fibers from carbon fiber-reinforced plastic (CFRP) in dimethyl sulfoxide (DMSO) at normal temperature and pressure. The results showed that the depolymerization rate of epoxy resin in CFRP increased with increasing ammonium acetate concentration and current density, and the influence of the current density was more significant than that of the concentration. Microscopic analysis showed that the recycled carbon fibers had few residual resin on their surfaces and mild electrochemical oxidation etching, and recycled carbon fiber monofilament achieved a tensile strength and an interfacial shear strength that were 93.55% and 118.76% those of the original fibers.

Considering that the current model of the world food system puts efficiency and profit first, many people still go hungry and seriously pollute the environment. In this paper, the multiple nonlinear regression method is used to optimize the existing food system. Firstly, the food security evaluation system is established, and the global food security situation in recent years is obtained by calculating FSSI. Then, the model of influencing factors of food security is established, and the relationship between food system security index and various factors is obtained by multiple nonlinear regression, on this basis, fairness and sustainability index are obtained by the same method, and the existing food system is optimized. After analyzing the current situation of countries with different standards, we have formulated a series of intelligent optimization policies for them. Finally, by comparing the change trend of the index before and after optimization, it is found that the optimized index can reach the ideal value more quickly.

Identifying cancer at the cellular level during an early stage offers the hope of greatly improved outcomes for cancer patients. As potential cancer biomarkers, nitroreductase (NTR) and human quinine oxidoreductase 1 (hNQO1) are overexpressed in many type of cancer cells. Simultaneous detection of these two biomarkers would benefit diagnostic precision in related cancers without yielding false positive results. Herein, based on a dye generated in situ strategy, a dual-enzyme-responsive probe, CNN, was rationally designed and synthesized by installing p-nitrobenzene and trimethyl-locked quinone propionic acid groups, which are specific for NTR and hNQO1, respectively, into a single fluorophore. This probe is only activated in the presence of both NTR and hNQO1 and produces a large fluorescence response, enabling the detection of both endogenous NTR and hNQO1 activity in living cells. The imaging results indicate that the CNN probe differentiates cancer cells (HeLa, MDA-MB-231 and HepG2 cells) from normal liver HL-7702 cells owing to the existence of relatively high endogenous levels of both biomarkers in these cancer cells.

How to solve the hypersonic aerothermodynamics around large-scale uncontrolled spacecraft during falling disintegrating process from outer space to earth, is the key to predict the flight track of the end-of-life spacecraft reentry crash. To study aerodynamics of spacecraft reentry covering various flow regimes, the Gas-Kinetic Unified Algorithm (GKUA) has been presented by computable modeling of the collision integral of the Boltzmann equation over tens of years. On this basis, the rotational and vibrational energy modes are considered as the independent variables of the gas molecular velocity distribution function, a kind of Boltzmann model equation involving internal energy excitation is constructed by decomposing the collision term of the Boltzmann equation into elastic and inelastic collision terms under the conservation of the summation invariant and the H-theorem. The unified algorithm of the Boltzmann model equation involving thermodynamics non-equilibrium effect is presented for the whole range of flow regimes. The gas-kinetic massive parallel computing strategy is developed to solve the hypersonic aerothermodynamics with the processor cores of 512∼115000 at least 90% parallel efficiency. To validate the accuracy of the GKUA, the hypersonic flows are simulated including the reentry Tiangong-1 spacecraft shape with the wide range of Knudsen numbers of 260∼0.00005 by the comparison of the related results from the DSMC and N-S coupled methods, and the low-density tunnel experiment etc. For uncontrolled spacecraft falling problem, the finite-element algorithm of dynamic thermal-force coupling response is presented, and the unified simulation of the thermal structural response and the hypersonic flow field is tested on the vertical plate, hollow sphere and Tiangong-1 shape under the reentry aerodynamic environment. Then, the forecasting analysis platform of end-of-life large-scale spacecraft flying track is established on the basis of ballistic computation combined with reentry aerothermodynamics and deformation failure/ablation/disintegration.

Mullite-whisker-reinforced anorthite-mullite-corundum porous ceramics were prepared from construction waste and Al 2 O 3 powder by adding AlF 3 and MoO 3 as the additive and crystallization catalyst, respectively. The effects of AlF 3 and MoO 3 content on the properties of mullite whiskers, such as open porosity, mechanical properties, pore size distribution, microstructure and phase structure, were investigated in detail. The results showed that the morphology of the mullite whiskers and properties of the porous ceramics were greatly influenced by the AlF 3 and MoO 3 content. The specimen obtained by co-adding 12 wt% AlF 3 and 3 wt% MoO 3 , and sintering at 1350 °C for 1 h, exhibited excellent properties, including an open porosity of 67.4±0.5% and biaxial flexural strength of 24.0±0.8 MPa. The mullite whiskers were uniformly distributed; the whiskers had a diameter of 0.05–0.5 µm, length of 8–10 µm, and aspect ratios (length to diameter ratio) of 20–30 on average.

© 2017 The Royal Society of Chemistry. Zn-ion batteries have been widely investigated due to their low cost, high safety and eco-friendliness. We comprehensively evaluate the performance of oxides (MoO3, TiO2, and Fe3O4), sulfides (MoS2, WS2, and MnS) and borides (TiB2 and ZrB2) in zinc ion battery systems. It is found that MnS is a good alternative cathode material with a reversible capacity of 221 mA h g-1, while the other materials show different behaviours.