A carrier (stainless steel disc as a default carrier) testing method is very needed for use in the actual food-processing fields by following the standard guideline. Here, we aimed to compare the ...virucidal efficacy of four commercial liquid disinfectants, including sodium hypochlorite (NaOCl), chlorine dioxide (ClO2), and peracetic acid (PAA) against hepatitis A virus (HAV) following the OECD guideline protocol based on the quantitative carrier testing method and compared carrier testing results with the suspension testing results. The OECD method specifies a test for establishing whether a chemical disinfectant or a microbicide has a virucidal activity on hard non-porous surfaces. The antiviral efficacy was evaluated by plaque assays, and disinfectants were considered effective if the virus reduction was greater than or equal to 3 log10 (99.9% decrease) for carrier or 4 log10 (99.99% decrease) for suspension tests. Results indicated that ClO2 above 500 ppm and 50% ethanol were effective in the carrier test method. In contrast, more than 200 ppm NaOCl and 50 ppm ClO2 for all exposure times and 70% ethanol with contact for more than 5 min were effective in suspension tests. Treatment with PAA (80–2500 ppm) were not effective in carrier or suspension tests. Therefore, we recommend the use of more than 500 ppm ClO2 or 50% ethanol with exposure for 10 min to disinfect surfaces that may be contaminated with HAV. Thus, these results could be effective in establishing official antiviral efficacy testing methods and basic data.
•We compared the virucidal efficacy of four disinfectants against HAV.•ClO2 above 500 ppm and 50% ethanol showed disinfection effects in carrier tests.•PAA (80–2500 ppm) showed no disinfection effects in carrier or suspension tests.•Disinfection of HAV was optimal with >500 ppm ClO2 or 50% ethanol for 10 min.
To investigate the impacts and related mechanisms of penehyclidine hydrochloride (PHC) on ischemia/reperfusion (I/R)-induced myocardial injury. A rat model of myocardial I/R injury was established by ...the ligation of left anterior descending coronary artery for 30 min followed by 3 h perfusion. Before I/R, the rats were pretreated with or without PHC. Cardiac function was measured by echocardiography. The activities/levels of myocardial enzymes, oxidants and antioxidant enzymes were detected. Evans blue/TTC double staining was performed to assess infarct size. Cardiomyocyte apoptosis was evaluated by TUNEL assay. The release of inflammatory cytokines and inflammatory mediators was detected by ELISA. Western blot was performed to analyze the expression of COX-2, IκB, p-IκB and NF-κB. Meanwhile, the rats were given a single injection of H-PHC before I/R. The effects of PHC on myocardial infarct and cardiac function were investigated after 7 days post-reperfusion. We found that PHC remarkably improved cardiac function, alleviated myocardial injury by decreasing myocardial enzyme levels and attenuated oxidative stress in a dose-dependent manner. Additionally, PHC preconditioning significantly reduced infarct size and the apoptotic rate of cardiomyocytes. Administration of PHC significantly decreased serum TNF-α, IL-1β, IL-6 and PGE2 levels and myocardium COX-2 level. Meanwhile, the expression levels of p-IκB and NF-κB were downregulated, while IκB expression was upregulated. H-PHC also exerted long-term cardioprotection in a rat model of I/R injury by decreasing infarct size and improving cardiac function. These results suggest that PHC can efficiently protect the rats against I/R-induced myocardial injury.
Global warming has exerted widespread impacts on the terrestrial ecosystem in the past three decades. Vegetation is an important part of the terrestrial ecosystem, and its net primary productivity ...(NPP) is an important variable in the exchange of materials and energy in the terrestrial ecosystem. However, the effect of climate variation on the spatial pattern of zonal distribution of NPP has remained unclear over the past two decades. Therefore, we analyzed the spatiotemporal patterns and trends of MODIS NPP and environmental factors (temperature, radiation, and soil moisture) derived from three sets of reanalysis data. The moving window method and digital elevation model (DEM) were used to explore their changes along elevation gradients. Finally, we explored the effect of environmental factors on the changes in NPP and its elevation distribution patterns. Results showed that nearly 60% of the global area exhibited an increase in NPP with increasing elevation. Soil moisture has the largest uncertainty either in the spatial pattern or inter-annual variation, while temperature has the smallest uncertainty among the three environmental factors. The uncertainty of environmental factors is also reflected in its impact on the elevation distribution of NPP, and temperature is still the main dominating environmental factor. Our research results imply that the carbon sequestration capability of vegetation is becoming increasingly prominent in high-elevation regions. However, the quantitative evaluation of its carbon sink (source) functions needs further research under global warming.
Drought is frequently recorded as a result of climate warming and elevated concentration of greenhouse gases, which affect the carbon and water cycles in terrestrial ecosystems, particularly in arid ...and semi-arid regions. To identify the drought in grassland ecosystems and to determine how such drought affects grassland ecosystems in terms of carbon and water cycles across the globe, this study evaluated the drought conditions of global grassland ecosystems from 2000 to 2011 on the basis of the remotely sensed Drought Severity Index (DSI) data. The temporal dynamics of grassland carbon use efficiency (CUE) and water use efficiency (WUE), as well as their correlations with DSI, were also investigated at the global scale. Results showed that 57.04% of grassland ecosystems experienced a dry trend over this period. In general, most grassland ecosystems in the northern hemisphere (N.H.) were in near normal condition, whereas those in the southern hemisphere (S.H.) experienced a clear drying and wetting trend, with the year 2005 regarded as the turning point. Grassland CUE increased continually despite the varied drought conditions over this period. By contrast, WUE increased in the closed shrublands and woody savannas but decreased in all the other grassland types. The drought conditions affected the carbon and water use mainly by influencing the primary production and evapotranspiration of grass through photosynthesis and transpiration process. The CUE and WUE of savannas was most sensitive to droughts among all the grassland types. The areas of grassland DSI that showed significant correlations with CUE and WUE were 52.92% and 22.11% of the total grassland areas, respectively. Overall, droughts sufficiently explained the dynamics of grassland CUE, especially in the S.H. In comparison with grassland CUE, the grassland WUE was less sensitive to drought conditions at the global scale.
Evolutionary multitask optimization (EMTO) has developed fast recently, and many algorithms have emerged that solve several different problems simultaneously through knowledge transfer. Most ...algorithms use a single search operator in their processing. However, different tasks have distinct characteristics, and a single operator is often inadequate to adapt to different stages of the same task. In this paper, we propose a multiple search operator selection strategy by adaptive probability allocation, named adaptive multi-operator selection (AMOS) to address EMTO that features rapid convergence of populations. It can automatically select the best multiple search operators based on the characteristics of specific tasks and different stages of evolution. The primary contributions of the proposed algorithm are as follows: (1) It combines the basic concepts of multi-operator integration and adaptive search operator selection to select the best multiple search operators for each task at different evolutionary stages; (2) It facilitates the knowledge transfer through different solving operators between tasks; (3) It can be flexibly embedded into various frameworks of general EMTO algorithms with good results. In the experiments, we validate the performance of AMOS on CEC2017 benchmark suite, CMTOPs benchmark suite, and real-world EMTO problems, and experimental results demonstrate the effectiveness and generality of the proposed strategy.
Soil respiration (Rs) is the largest carbon (C) flux from terrestrial ecosystems to the atmosphere. Predictions of Rs and associated feedback to climate change remain largely uncertain, in part due ...to the high temporal heterogeneity of temperature sensitivity (apparent Q10) of Rs under a changing climate. Therefore, it is of critical importance to provide better insight into how Q10 varies across multiple temporal scales. We investigated the diurnal, seasonal, and annual variabilities in the Q10 of Rs using continuous Rs measurements (at hourly intervals) over six growing seasons in a mature temperate larch plantation in North China. We found that night-time values of Q10 were slightly lower than daytime values. Large seasonal and annual fluctuations of Q10 were observed, as illustrated by high coefficients of variation of 15.0% and 21.8%, respectively. The higher Q10 in spring and autumn were primarily regulated by fine root growth and higher soil moisture after snow melt in spring, and leaf senescence in autumn. Lower Q10 in summer may have been caused by limitations in substrate availability and microbial activity resulting from drought, which also caused a decoupling of Rs from soil temperature in summer. Furthermore, a bivariate nonlinear model incorporating both soil temperature and soil moisture best explained Q10 variability. Generally, lower soil temperature and higher soil moisture lead to higher values of Q10, indicating that climate warming could exert a negative effect on Q10, partially offsetting the warming-induced increase in soil C loss. We provide long-term field experimental evidence that it would be inappropriate to estimate Rs on a multiyear scale using a fixed Q10 value or a value obtained from one season and/or one year. Thus, we emphasize the importance of incorporating the seasonal and annual heterogeneities of Q10 into C cycle model simulations under future climate change scenarios.
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•Soil respiration (Rs) was continuously measured in a plantation from 2012 to 2017.•Temperature sensitivities (Q10) of Rs across multiple time scales were investigated.•No diurnal but high seasonal and annual variations of Q10 were observed.•The decoupling of Rs from soil temperature in summer supports the CQT hypothesis.•The combination of soil temperature and soil moisture drives variation in Q10.
Accurate localization of partial discharge in GIS equipment remains a key focus of daily maintenance for substations, which can be achieved through advanced detection and location techniques, as well ...as regular maintenance and testing of the equipment. However, there is currently an issue with low accuracy in the localization algorithm. Aiming at the problems of low precision and local optimization of the swarm intelligence algorithm in partial discharge localization system of GIS equipment, this paper proposes a 3D localization algorithm based on a time difference of arrival (TDOA) model of the improved artificial fish swarm algorithm (IAFSA). By introducing the investigation behaviour of the artificial bee colony(ABC) algorithm into the artificial fish swarms algorithm (AFSA), this algorithm is more efficient to jump out of the local extremum, enhance the optimization performance, improve the global search ability and overcome the premature convergence. Furthermore, more precise positioning can be achieved with dynamic parameters. The results of the testing function show that IAFSA is significantly superior to AFSA and particle swarm optimization (PSO) in terms of positioning accuracy and stability. When applied to partial discharge localization experiments, the maximum relative positioning error is less than 2.5%. This validates that the proposed method in this paper can achieve high-precision partial discharge localization, has good engineering application value, and provides strong support for the safe operation of GIS equipment.
The vegetation of the Qinghai–Tibet Plateau (QTP) is vital to the global climate change and ecological security of China. However, the impact of climate variation on the spatial pattern and zonal ...distribution of vegetation in the QTP remains unclear. Accordingly, we used multisource remote-sensing vegetation indices (GIMMS-LAI, GIMMS NDVI, GLOBMAP LAI, MODIS EVI, MODIS NDVI, and MODIS NIRv), climate data, a digital elevation model, and the moving window method to investigate the changes in vegetation greenness and its response to climate variations in the QTP from 2001 to 2016. Results showed that the vegetation was greening in the QTP, which might be attributed to the increases in temperature and radiation. By contrast, the browning of vegetation may be caused by drought. Notably, the spatial patterns of vegetation greenness and its variations were linearly correlated with climate at low altitudes, and vegetation greenness was non-linearly correlated with climate at high altitudes. The Northwestern QTP needs to be focused on in regard to positive and decreased VGEG (vegetation greenness along the elevation gradient). The significantly positive VGEG was up to (34.37 ± 2.21) % of the QTP, which indicated a homogenization of vegetation greenness on elevation. This study will help us to understand the spatial distribution of vegetation greenness and VGEG in the QTP under global warming, and it will benefit ecological environment management, policymaking, and future climate and carbon sink (source) prediction.
This paper reports the synthesis and application of nanosilver antibacterial materials. The preparation methods of nanosilver complexes are described. The effect of silver nitrate concentration and ...nanosilver dispersion on antibacterial properties was analysed. In this experiment, TEMPO oxidant was used to oxidize hydroxyl on the C
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position of wood nanocellulose into a carboxyl group. Meanwhile, carboxyl compound was used to react with AgNO
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, the silver composite material was prepared with PVA as the substrate. We use interface grafting. The surface of cellulose is bonded with reactive functional groups to form a transition layer. To improve the interface bonding between matrix and reinforcing fiber. The Ag-NC-PVA nanocomposite film was characterized by UV–Vis, SEM, TEM, mechanical properties and antibacterial properties analysis. SEM and TEM images showed that the size of most silver nanoparticles ranged from 5 to 20 nm; the mean particle size was 10 nm. The mechanical properties of Ag-NC-PVA films were greater than that of PVA film. When the amount of Ag-NC was 4%, its tensile strength was 71.3 MPa; it’s almost 15% higher than PVA. After antibacterial analysis, Ag-NC endowed PVA with excellent antibacterial properties. The prepared Ag-NC-PVA greatly promotes the practical application development of the silver-based composite bacteriostatic material.
Global warming has a great impact on the activities of terrestrial vegetation. A consensus has been reached that the global vegetation is greening from the 1980–2010s. However, the trends of global ...vegetation are highly uncertain after 2000. Therefore, we used multi-source remote sensing vegetation index (VI), climate data, and Mann–Kendall trend analysis to explore the global vegetation trend and its uncertainty from 2001 to 2016. The effects of climate on the changes in vegetation were also investigated. We found that GIMMS-based VIs exhibited decreasing trends. By contrast, MODIS-based VIs and GLOBMAP LAI tended to increase. Evergreen broad-leaf forest contributed the most to the uncertainty of global vegetation trends, and the uncertainty of December–January–February and September–October–November was higher than that in the other seasons. The correlation of forest VI and temperature was the highest in March–April–May, whereas the correlation of non-forest VI and precipitation was higher than that of the forest. The anomalies of GIMMS-based VIs and mean annual precipitation were more consistent in the evergreen broad-leaf forest, woody savannas, mixed forest, evergreen needle-leaf forest, and deciduous needle-leaf forest than those in biomes under the impact of 2015–2016 El Niño.
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