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Once the structure of a metamaterial is fixed, it has the property of controlling elastic waves in a fixed frequency range. To obtain a metamaterial with an optimal structure, a co-simulation optimization method is proposed in this paper to optimize the acoustic properties of metamaterials. The method combines the advantages of COMSOL, MATLAB, and ISIGHT to obtain optimal results. Due to the application of the algorithms in ISIGHT, different design requirements can be met, such as designing the bandgap frequency of the acoustic metamaterial in a specific range, reducing the frequency of the bandgap, and improving the overall performance of the STL (sound transmission loss) without manual tuning. To test the feasibility of the method, a new double-panel acoustic metamaterial is also proposed, where the bandgap interval of the metamaterial can be designed to nearly 240 Hz by using the thickness of the support columns and the structural parameters of the open split-ring resonance as bandgap optimization parameters. The bandgap interval can also be lowered from 174 to 193 Hz when different optimization targets are chosen. In addition, the overall performance of the STL can be optimized, showing better absorption of low-frequency noise. Therefore, this co-simulation method can achieve multi-parameter optimization for different optimization targets and ensure that the results obtained by the applied algorithm are optimal. Furthermore, this method has great potential in further development as it avoids complex algorithm programming. [ABSTRACT FROM AUTHOR]

Introduction: The military is a risk environment for cigarette smoking. This study determined the prevalence of, cessation attempts, knowledge, and attitudes regarding smoking, and factors related to it in the Chinese navy.Materials and Methods: A cross-sectional survey was conducted of military personnel on active duty in the Chinese navy, Guangdong province. Data were collected using a standard structured questionnaire and analyzed through SPSS. Multiple logistic regression was used to examine factors associated with smoking. The research protocols were reviewed and approved by the Institutional Review Board of Naval Medical University, and participants gave written informed consent.Results: A total of 1,530 military personnel who had served for >3 months completed the survey, 859 (56.14%) of whom were current smokers. The main reasons for smoking were stress alleviation and social needs. A total of 377 smokers had previously attempted quitting. More than half considered the military environment supportive of smoking. Subjects' knowledge regarding smoking mainly comprised negative respiratory-health effects. Smoking status was related to education level, military service duration, number of smoking family members, and smoking knowledge.Conclusions: Smoking prevalence in the Chinese navy is higher than that among Chinese civilians and the US and UK military personnel. Although many sailors are aware of the dangers of smoking to their health, they seldom get advice or help regarding smoking cessation. Most smokers believed that smoking cessation could improve their health. Therefore, the navy should formulate policies encouraging and facilitating military personnel's smoking cessation. [ABSTRACT FROM AUTHOR]

Scheduling algorithms are crucial for most existing switches to improve the throughput. However, the delay of the switching fabric cannot be guaranteed with such scheduling algorithms. This paper aims to design a novel load-balanced wire-speed multicast switching fabric along with the attractive merits of network coding. We adopt a two-phase self-routing switching fabric constructed by Boolean-multicast concentrators (SRBMCs), where the first SRBMC distributes the incoming cells to its outputs uniformly and the second allows the distributed cells to be self-routed and multicast to their destinations concurrently. To further improve the switching performance, linear network coding is smoothly combined with SRBMC to reduce the packet loss rate. Theoretical analysis and numerical simulation demonstrate that the proposed switching fabric cannot only achieve wire-speed multicast switching but also be recursively constructed into an indefinite large-scale one with such merits as no internal buffers, low complexity, and guarantee in switching delay. Finally, we implement the proposed fabric on Field-Programmable Gate Array and verify its performance in multicast switching. [ABSTRACT FROM AUTHOR]

As a key policy tool for China' s achievement of the goals of reaching peak carbon emissions and carbon neutrality, the carbon emissions trading mechanism has attracted widespread attention for its effect on reducing pollution and carbon emissions. This study incorporated carbon dioxide reduction and environmental pollution control into the same research framework. Based on the panel data of 30 provinces in China from 2010 to 2019, it took the carbon emissions trading mechanism as the policy background and used the improved entropy weight TOPSIS model to calculate the environmental pollution index to measure the local environmental quality and environmental pollution degree. The intersection term of carbon emissions and environmental pollution index was used to characterize the level of pollution reduction and carbon reduction. The difference-in-differences model and the synthetic control method were used to empirically test the pollution and carbon emission reduction effects of the carbon emissions trading mechanism. The results showed that: (1) From the perspective of the average treatment effect of the policy, the carbon emissions trading mechanism reduced the emissions of carbon dioxide and environmental pollutants in the pilot provinces compared with non-pilot provinces. After adding relevant control variables, the level of pollution and carbon reduction in the pilot provinces increased by 16%. From the perspective of the policy effects of pilot individuals, Beijing, Shanghai, Tianjin, and Chongqing performed better; that is, their carbon emissions showed a significant downward trend, followed by Guangdong, while Hubei performed worse. (2) The influential mechanisms and heterogeneity test revealed that the carbon emissions trading system achieved an increase in the synergistic governance level of pollution and carbon reduction through energy consumption restructuring and technological innovation. (3) Meanwhile, the pollution and carbon reduction levels showed regional heterogeneity, with the eastern and western regions performing best and the central region performing poorly. Furthermore, a grey correlation model was used to investigate the relationship between the pollution and carbon reduction levels and the potential for synergistic emission reduction in each province. The results found that the average correlation degree of Shanghai, Guangdong, Guangxi, Guizhou, and Xinjiang was greater than other provinces, showing a higher level and potential. Therefore, it is necessary to accelerate and improve the construction of the national carbon emissions trading market; give full play to the synergistic emissions reduction effects of market-based carbon emissions trading policies on carbon dioxide emissions and environmental pollutants; and accelerate the synergy of carbon emissions trading policies by increasing investment in technological innovation and the transformation and upgrading of energy consumption structures and formulating regionally differentiated carbon emission reduction policies. [ABSTRACT FROM AUTHOR]

The red soil region in China is very important to agriculture. However, soil aluminum (Al) toxicity often occurs as a result of the high soil acidity. In a long-term experiment, we analyzed soil samples to determine the effect of fertilization on soil acidity and potential Al toxicity. The results showed that after 12 years of utilization, Al toxicity occurred in the soil of the control plot. Chemical fertilizer further decreased soil pH and intensified Al toxicity. However, rice straw effectively improved soil pH and ameliorated soil Al toxicity from 0 to 50 cm deep, which may be attributed to the accumulated soil organic matter (SOM) and the decomposition of the rice straw. Corresponding to the lower Al content in soil, peanut crops grew healthier with greater yields in the rice straw plot, indicating that returning crop stalks to the field should be a feasible fertilization strategy in the region. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1. A modified creep crack opening displacement (CCTOD) theoretical model is presented firstly. • 2. A numerical simulation model of specimens with a crack tip is established. • 3. About 10% CTOD increment is induced by room temperature creep of specimen. • 4. The loads effect and load history can effect on the CCTOD at room temperature creep. The room temperature creep behavior of X80 pipeline steel has attracted increasing attention because it is considered to be the main cause of time-delayed failure in pipeline steel. The crack tip opening displacement (CTOD) is a general criterion to characterize the time-delayed failure and assessment safety of pipeline steel. However, there are few methods to demonstrate crack behavior of the pipeline steel caused by room temperature creep. Based on the traditional CTOD theoretical model, a modified creep crack tip opening displacement (CCTOD) theoretical model is presented to calculate the CCTOD from the crack mouth opening displacement (CMOD). The room temperature creep experiment with a single edge notched beam subjected to three-point bending creep load for 36 h at room temperature is performed to know more about the CCTOD of X80 pipeline steel. Based on a power-law time delayed relationship among creep strain, stress and time fitted from experiment results of tensile creep tests, the finite element model is also established to evaluation the CCTOD of pipeline steel at room temperature. It is found that there is about 10% CTOD increment caused by room temperature creep added to that of the traditional elastic and plastic CTOD which indicates that room temperature creep is also further blunted the crack tip of X80 pipeline steel. Meanwhile, The results will provide an approach for failure evaluation and an integrity guideline for X80 pipeline steel. [ABSTRACT FROM AUTHOR]

• Experimental analysis of the effect of room temperature creep on the fracture toughness of X80 pipeline steel. • The test data were fitted to a power-law equation which showed that after 36 h of creep at room temperature, the incremental crack tip opening displacement was approximately 0.0098 mm. • A time-dependent CTOD model was proposed regarding room temperature creep. And a pressure reduction strategy is proposed based on this criterion. The growing demand for energy consumption has led to the rapid development of high strength and high toughness pipeline steel technology, with fracture toughness being a crucial factor in evaluating the mechanical properties of pipeline steel. Despite experimental studies demonstrating that metallic materials, including pipeline steel, undergo creep at room temperature, the effects of room temperature creep (RTC) on pipeline steel fracture properties are still relatively unexplained. This study analyzes the impact of RTC on the fracture toughness of X80pipeline steel, using the X80pipeline steel base material as the research object. Firstly, the time-dependent change in crack notch opening displacement is added to the calculation formula for fracture toughness of three-point bending specimens, considering the effect of RTC. The test data is fitted to a power-law equation of the form, where k = 0.01423 and m = - 0.89651 , with the improved formula indicating an incremental CTOD of approximately 0.0098 mm after 36 h of RTC for X80 pipeline steel. Secondly, a time-dependent CTOD model is proposed based on the ductile defect growth model, with the plastic part derived from the D-B model and the creep part obtained by fitting the test data. The study proposes a CTOD criterion for RTC and a pressure reduction strategy based on this criterion, providing a reference for quantitatively assessing the fracture toughness of pipeline steel under RTC conditions. [ABSTRACT FROM AUTHOR]

Objective Posttraumatic immune disorder can cause complications including systemic inflammatory response syndrome (SIRS) and multiple-organ dysfunction syndrome (MODS). Cytotoxic granules containing perforin and granzyme-B (GrB) are released by cytotoxic CD8 + T lymphocytes, NK and γδT cells after major trauma. This prospective clinical study was designed to analyze the association between these immune components and complications after major trauma. Methods We retrospectively studied 48 patients aged between 16 and 65 years admitted within 90 min of major trauma (Injury Severity Score > 16) and surviving beyond 7 days, and 20 healthy controls. Blood samples were drawn on admission and after 1, 3 and 7 days. CD8 + T, NK and γδT cell counts in peripheral blood and the levels of perforin and GrB in these cells were analyzed by flow cytometry. Clinical aspects of MODS and SIRS were recorded daily. Results CD8 + T cell counts were not significantly different in patients with SIRS or uncomplicated group, but were depressed in the MODS group after trauma. However, NK cell counts in patients with MODS were significantly depressed only at day 7 after injury, and γδT cell counts were significantly depressed after trauma. Perforin levels in CD8 + T, NK and γδT cells in patients with MODS were depressed after trauma. GrB levels in NK, CD8 + T and γδT cells in patients with MODS were significantly depressed at 3 and 7 days post trauma. Conclusion Posttraumatic MODS is associated with early, sustained, and severe depression of lymphocytes. [ABSTRACT FROM AUTHOR]

Introduction: Pancreatic cancer (PC) is one of the leading causes of cancer, with the lowest 5-year survival rate of all cancer types. Given the fast metastasis of PC and its resistance to surgery, radiotherapy, chemotherapy, and combinations thereof, it is imperative to develop more effective anti-PC drugs. Phillygenin (PHI) has been reported to exert anti-cancer, anti-bacterial, and anti‐inflammatory properties. However, the mechanism of PHI in the development of PC is still unclear. Methods: The cytotoxicity of PHI in pancreatic cancer cells was evaluated by MTT assay, and clonogenic assay was used to test the anti-proliferation of PHI. The pro-apoptotic effect of PHI was detected by flow cytometry analysis. The changes of epithelial–mesenchymal transition (EMT) in pancreatic cancer cells treated with PHI were determined by Western blot. Transwell assay was used to test the migration and invasion of PC cells after treatment with PHI. Molecular docking was used to predict the potential binding site of candidate target with PHI. Results: PHI could inhibit the proliferation, migration, and EMT of PC cells (PANC-1 and SW1990) and induce its apoptosis. Analysis of the Cancer Genome Atlas database indicated that elevated MELK levels correlated with poor overall survival (OS) and disease-free survival (DFS) of PC patients. In addition, molecular modeling showed that PHI may potentially target the catalytic domain of maternal embryonic leucine zipper kinase (MELK). Overexpression of MELK muted the anti-PC effects of PHI. Conclusion: PHI holds promise as a potent candidate drug for the treatment of PC via targeted MELK. [ABSTRACT FROM AUTHOR]

In this paper, a novel electrostatic-assisted melt blown process was reported to produce polypropylene (PP) microfibers with a diameter as fine as 600 nm. The morphology, web structure, pore size distribution, filtration efficiency, and the stress and strain behavior of the PP nonwoven fabric thus prepared were characterized. By introducing an electrostatic field into the conventional melt-blown apparatus, the average diameter of the melt-blown fibers was reduced from 1.69 to 0.96 μm with the experimental setup, and the distribution of fiber diameters was narrower, which resulted in a filter medium with smaller average pore size and improved filtration efficiency. The polymer microfibers prepared by this electrostatic-assisted melt blown method may be adapted in a continuous melt blown process for the production of filtration media used in air filters, dust masks, and so on. [ABSTRACT FROM AUTHOR]

Because of the increasingly environmental and health concerns over conventional polyurethanes that manifested by toxic isocyanates and unsustainable fossil-based polyols, there is a great interest in non-isocyanate polyurethanes (NIPUs) production from renewable biomass resources. Herein, under the concept of biorefinery, the sweet potato residue (SPR) from starch industry, rich in non-biological toxicity starch, holocellulose and vegetable protein, was considered as the raw material for the NIPUs. During the process, the crude SPR was first liquified into chain-extending homogeneous molecules that were enriched in active hydroxyl-groups, followed by undergoing epoxidation and carbonation. Then, the obtained cyclic carbonate precursor was crosslinked with amines for the final NIPUs. The as-prepared SPR-derived NIPUs exhibited attractive mechanical and thermodynamic properties. To test the applicability, the food preservation performances of the SPR-derived NIPUs was further investigated. After spray coating the NIPUs on the banana peel, the dark brown spots in the testing group were significantly reduced after half-month storage. Therefore, the SPR-derived NIPUs provides a foundation for the futural food packaging alternatives. [Display omitted] • Non-isocyanate polyurethane films were prepared using sweet potato residues. • The sweet potato residue was functionalized before crosslinking with amines. • The non-isocyanate polyurethane films exhibited good mechanical properties. • The non-isocyanate polyurethanes performances were dependent on the type of amines. • The non-isocyanate polyurethane films can be used for foods preservation. [ABSTRACT FROM AUTHOR]

Herein, a novel form of bicomponent nanofiber membrane containing stereo-complex polylactic acid (SC-PLA) was successfully produced by the side-by-side electrospinning of Poly (L-lactic acid) (PLLA) and Poly (D-lactic acid) (PDLA). We demonstrate that through these environmentally sustainable materials, highly efficient nanofiber assemblies for filtration can be constructed at very low basis weight. The physical and morphological structure, crystalline structure, hydrophobicity, porous structure, and filtration performance of the fibrous membranes were thoroughly characterized. It was shown that the fabricated polylactic acid (PLA) side-by-side fiber membrane had the advantages of excellent hydrophobicity, small average pore size, high porosity, high filtration efficiency, low pressure drop as well as superior air permeability. At the very low basis weight of 1.1 g/m2, the filtration efficiency and pressure drop of the prepared side-by-side membrane reached 96.2% and 30 Pa, respectively. Overall, this biomass-based, biodegradable filtration material has the potential to replace the fossil fuel-based polypropylene commercial meltblown materials for the design and development in filtration, separation, biomedical, personal protection and other fields. [ABSTRACT FROM AUTHOR]

Potentilla chinesis Ser. (Wei Ling Cai) was a food for humans and animals in China, as well as a traditional Chinese herb recorded in "ZhonghuaBencao". Aeromonas hydrophila NJ-35 (NJ-35) was a bacterial pathogen associated with high mortality rate in aquaculture. The purpose of the present work was to isolate and identify the anti-bacterial components against the NJ-35 from the extract of Wei Ling Cai, as well as explore the underlying anti-bacterial mechanism. The peak 3 was the most efficient anti-bacterial component in all collected peaks, and it was identified as (1 R ,2 S ,5 R ,6 S)-2,6-bis(3-ethyl-4-hydroxy-5-methoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (P-3) by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR). The minimum inhibition concentration (MIC) of P-3 against NJ-35 was 0.125 mg/mL. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) combined with NanoLC-ESI-MS/MS showed that, in the P-3- treated group, the proteins of phosphoglucomutase (PGM), pyruvate dehydrogenase E1 and alkyl hydroperoxide reductase subunit C (AhpC) were up-regulated, whereas, the porin and 30S ribosomal S3 were down-regulated. In addition, after the treatment of P-3 , the activity of alkaline phosphatase (AKP) and the membrane permeability were increased (P < 0.01). The results of scanning electron microscope (SEM) showed that P-3 made the NJ-35 shriveled, sunken, and wrinkled. Taken together, these results suggested the P-3 might be a promising anti-bacterial agent for pharmacological research, and Wei Ling Cai could be a food-borne treatment for the A. hydrophila infection in aquaculture. [Display omitted] • The Potentilla chinensis Ser. (Wei Ling Cai) could inhibit the growth of NJ-35. • The active anti-bacterial components were separated and identified as P-3. • The P-3 could destroy of the cell wall and cell membrane of NJ-35. • The P-3 could inhibit the protein synthesis of NJ-35. [ABSTRACT FROM AUTHOR]

Development of a novel filter material is urgently required for replacing the high-cost flue gas purification technology in the simultaneous removal of both fine dust and Nitrogen oxides (NOx). In this study; polyphenylene sulfide (PPS) needle-punching fibrous felts (NPFF) were employed as the filter material to remove the fine dust; and in the meanwhile; Mn and Ce oxides were loaded onto the PPS NPFF as the catalyst for selective catalytic reduction of NOx with NH3. Two different pretreatment methods; i.e., sodium alginate (SA) deposition and plasma treatment; were employed to modify the PPS NPFF before the traditional impregnation and thermal treatment processes during the catalyst loading. The results showed that these two pretreatment methods both afforded the PPS NPFF with the enhanced loading rate and stability of Mn/Ce oxides compared to those without any pretreatments; which were significantly beneficial for the denitration application. Moreover; we found that both SA deposition and plasma pre-treated samples presented excellent dust-removal properties; and the filtration efficiency could reach 100% when the particle size of the fine particulates was above 4 μm. This study demonstrated that our Mn/Ce oxides decorated PPS NPFF have great potential to be applied in the fuel gas purification field; due to their stable structure; handling convenience; and excellent filtration efficiency; as well as high denitration performance. [ABSTRACT FROM AUTHOR]

Removal of trace water from oil is essential for a high‐performance fuel supply system. Trace water in fuel is a crucial contributor to frequent system maintenance and failure. In this work, an electrospun polyacrylic acid/polyvinyl alcohol (PAA/PVA) nanofibrous xerogel membrane (NFM) is prepared to remove trace water in oil. Based on the optimization of the weight ratio and the crosslinking conditions of PAA/PVA, the resultant NFM shows remarkable water‐retaining capacity (swelling ratio of 124.8 g/g) and rapid absorption property. The optimal membrane displays a small average pore size of 523.2 nm, high porosity of 79.6% as well as robust tensile strength of 8.1 MPa. Additionally, after just one pass through a single layer membrane (thickness of 35 ± 3 µm and areal density of 3.5 ± 0.5 g m−2), the milky oil containing 1 wt% water is clarified and the water content reduced to 130 ppm. With extensive water being absorbed into the 3D network (different with the conventional separation mechanism) as well as good compatibility with oil, a multilayer pleated scheme may provide a practical methodology for enhancing fuel oil properties and performances. [ABSTRACT FROM AUTHOR]

Bicomponent composite fibers, due to their unique versatility, have attracted great attention in many fields, such as filtration, energy, and bioengineering. Herein, we efficiently fabricated polyvinylidene fluoride/polyimide (PVDF/PI) side-by-side bicomponent nanofibers based on electrospinning, which resulted in the synergism between PVDF and PI, and eventually obtained the effect of 1 + 1 > 2. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and chemical structure of nanofibers, indicating that a large number of side-by-side nanofibers were successfully prepared. Further, the thermal stability, mechanical strength, and filtration properties of PVDF/PI were carefully investigated. The results revealed that the bicomponent nanofibers possessed both good mechanical strength and remarkable thermal stability. Moreover, the mechanical properties of PVDF/ PI were strengthened by more than twice after the heat treatment (7.28 MPa at 25 °C, 15.49 MPa at 230 °C). Simultaneously, after the heat treatment at 230 °C for 30 min, the filtration efficiency of PVDF/PI membrane was maintained at about 95.45 ± 1.09%, and the pressure drop was relatively low. Therefore, the prepared PVDF/PI side-by-side bicomponent nanofibers have a favorable prospect of application in the field of medium- and high-temperature filtration, which further expands the application range of electrospun fiber membranes. [ABSTRACT FROM AUTHOR]