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•UV-Cl2 and UV/Cl2 processes generated synergetic effects for sul1 gene deactivation.•Difference of DNA size affected gene deactivation by individual UV and chlorination.•UV/Cl2 and ...UV-Cl2 used corresponding reactivity of single processes to generate synergy values.•Formation of HO· contributed to up to 45 % of the synergy values in UV/Cl2 process.•The contribution of Cl· to sul1 gene deactivation in UV/Cl2 process was negligible.
Nowadays, antibiotic resistance genes (ARGs) have been characterized as an emerging environmental contaminant, as the spread of ARGs may increase the difficulty of bacterial infection treatments. This study evaluates the combination of ultraviolet (UV) irradiation and chlorination, the two most commonly applied disinfection methods, on the degradation of sulphonamide resistance sul1 genes. The results revealed that although both of individual UV and chlorination processes were relatively less effective, two of the four combined processes, namely UV followed by chlorination (UV-Cl2) and simultaneous combination of UV and chlorination (UV/Cl2), delivered a better removal rate (up to 1.5 logs) with an observation of synergetic effects up to 0.609 log. The mechanisms analysis found that the difference of DNA size affected sul1 genes degradation by UV and chlorination; targeted genes on larger DNA fragments could be more effectively degraded by UV (1.09 logs for large fragments and 0.12 log for small fragments when UV dose reached 432 mJ/cm2), while to degrade ARGs on smaller DNA fragments required less free chlorine dosage (10 mg/L for small fragments and 40 mg/L for large fragments). The sequential combination of UV and chlorination (UV-Cl2) used the corresponding reactivity of both processes, which could be the reason for the synergetic effect. For UV/Cl2 process, the formation of reactive oxygen species (ROS) contributed to the synergetic effect. Scavenger analysis showed that the contribution of ROS to the sul1 gene reduction was 0.004 to 0.273 log (up to 45.5 % of the total synergy values), and among the two major reactive species in UV/Cl2 system, HO was the more important radical, while the contribution of Cl was negligible. Besides, UV/Cl2 process also used the corresponding reactivity of both processes to generate the remaining synergy values when excluding the contribution by reactive radicals. These findings provide a thorough understanding of the effects of UV and free chlorine on the degradation of ARGs and indicate the potential to utilize the combined processes of UV and free chlorine in water or wastewater treatment practice to control the dissemination of antibiotic resistance.
Fiber structures with nanoscale diameters offer many fascinating features, such as excellent mechanical properties and high specific surface areas, making them attractive for many applications. Among ...a variety of technologies for preparing nanofibers, electrospinning is rapidly evolving into a simple process, which is capable of forming diverse morphologies due to its flexibility, functionality, and simplicity. In such review, more emphasis is put on the construction of polymer nanofiber structures and their potential applications. Other issues of electrospinning device, mechanism, and prospects, are also discussed. Specifically, by carefully regulating the operating condition, modifying needle device, optimizing properties of the polymer solutions, some unique structures of core⁻shell, side-by-side, multilayer, hollow interior, and high porosity can be obtained. Taken together, these well-organized polymer nanofibers can be of great interest in biomedicine, nutrition, bioengineering, pharmaceutics, and healthcare applications.
This paper proposes a time- and event-triggered hybrid scheduling for remote state estimation with limited communication resources. A smart sensor observes a physical process and decides whether to ...send the local state estimate to a remote estimator via a wireless communication channel; the estimator computes the state estimate of the process according to the received data packets and the known scheduling mechanism. Based on the existing optimal time-triggered scheduling, we employ a stochastic event trigger to save precious communication chances and further improve the estimation performance. The minimum mean-squared error (MMSE) state estimate is derived since the Gaussian property is preserved. The estimation performance upper bound and communication rate are analyzed. The main results are illustrated by numerical examples.
Assembly of 2D MXene sheets into a 3D macroscopic architecture is highly desirable to overcome the severe restacking problem of 2D MXene sheets and develop MXene‐based functional materials. However, ...unlike graphene, 3D MXene macroassembly directly from the individual 2D sheets is hard to achieve for the intrinsic property of MXene. Here a new gelation method is reported to prepare a 3D structured hydrogel from 2D MXene sheets that is assisted by graphene oxide and a suitable reductant. As a supercapacitor electrode, the hydrogel delivers a superb capacitance up to 370 F g−1 at 5 A g−1, and more promisingly, demonstrates an exceptionally high rate performance with the capacitance of 165 F g−1 even at 1000 A g−1. Moreover, using controllable drying processes, MXene hydrogels are transformed into different monoliths with structures ranging from a loosely organized porous aerogel to a dense solid. As a result, a 3D porous MXene aerogel shows excellent adsorption capacity to simultaneously remove various classes of organic liquids and heavy metal ions while the dense solid has excellent mechanical performance with a high Young's modulus and hardness.
A new MXene gelation method is demonstrated by assembling MXene flakes into a 3D hydrogel in the presence of graphene oxide and ethylene diamine. The resulting hydrogel shows an ultrahigh capacitance and an exceptionally high rate performance for supercapacitors and is ready to produce a MXene porous aerogel and dense solid with great promise in pollutant removal and compact energy storage.
This study aims to investigate the relationship between household space heating energy use and urban form (land use characteristics) for the Greater Dublin Region. The geographical distributions of ...household energy use are evaluated at the Enumeration Districts (ED) level based on the building thermal balance model. Moreover, it estimates the impact of possible factors on the household space heating consumption. Results illustrate that the distribution profile of dwellings is a significant factor related to overall heating energy demand and individual dwelling energy consumption for space heating. Residents living in compact dwellings with small floor areas consume less energy for space heating than residents living in dwellings with big floor areas. Moreover, domestic heating energy demand per household was also estimated for two extreme urban development scenarios: the compact city scenario and the dispersed scenario. The results illustrate that the compact city scenario is likely to decrease the domestic heating energy consumption per household by 16.2% compared with the dispersed city scenario. Correspondingly, the energy-related CO2 emissions could be significantly decreased by compact city scenario compared with the dispersed city scenario.
► A method was developed to investigate urban form impacts on energy demand. ► This study estimates impacts of possible factors on the household energy consumption. ► Household heating energy demand is sensitive to dwelling distribution profile. ► The compact case could reduce domestic energy demand compared with the dispersed case.
To develop a highly efficient visible light-induced and conveniently recyclable photocatalyst, in this study, a ternary magnetic ZnO/Fe
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O
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/g-C
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N
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composite photocatalyst was synthesized for ...the photodegradation of Monas dye. The structure and optical performance of the composite photocatalyst were characterized using X-ray diffraction (XRD), transmission electron microscopye (TEM), energy dispersive spectroscopy (EDS), photoluminescence (PL) spectra, ultraviolet–visible diffuse reflection, and photo-electrochemistry. The photocatalytic activities of the prepared ZnO/Fe
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O
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/g-C
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nanocomposites were notably improved, and they were significantly higher than those of pure g-C
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and ZnO. Given the presence of the heterojunction between the interfaces of g-C
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N
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and ZnO, the higher response to visible light and separation efficiency of the photo-induced electrons and holes enhanced the photocatalytic activities of the ZnO/Fe
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/g-C
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N
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nanocomposites. The stability experiment revealed that ZnO/Fe
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O
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/g-C
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N
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-50% demonstrates a relatively higher photocatalytic activity after 5 recycles. The degradation efficiency of MO, AYR, and OG over ZnO/Fe
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O
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/g-C
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N
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-50% were 97.87%, 98.05%, and 83.35%, respectively, which was due to the number of dye molecules adsorbed on the photocatalyst and the structure of the azo dye molecule. Azo dyes could be effectively and rapidly photodegraded by the obtained photocatalyst. Therefore, the environment-friendly photocatalyst could be widely applied to the treatment of dye contaminated wastewater.
Bacillus subtilis as microbial fertilizers contribute to avoiding the harmful effects of traditional agricultural fertilizers and pesticides. However, there are many restrictions on the practical ...application of fertilizers. In this study, microbial biochar formulations (BCMs) were prepared by loading biochar with B. subtilis SL-44. Pot experiments were conducted to evaluate the effects of the BCMs on soil fertility, Fusarium wilt control, and radish plant growth. The application of BCMs dramatically improved soil properties and favored plant growth. Compared with SL-44 and biochar treatments, the BCMs treatments increased radish plant physical-chemical properties and activities of several enzymes in the soil. What’s more, Fusarium wilt incidence had decreased by 59.88%. In addition, the BCMs treatments exhibited a significant increase in the abundance of bacterial genera in the rhizosphere soil of radish. Therefore, this study demonstrated that BCMs may be an eco-friendly strategy for improving soil fertility, reducing Fusarium wilt, and promoting radish plant growth.
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•Biochar can effectively capture SL-44 to form a tightly bound biofilm.•The BCMs improve the soil environment and favor plant growth.•The BCMs reduce damage from Fusarium wilt and promote plant growth.•The BCMs increase the abundance of beneficial microorganisms.
Nitrogen (N) and phosphorus (P) flows from land to sea in the Yangtze River basin were simulated for the period 1900–2010, by combining models for hydrology, nutrient input to surface water, and an ...in-stream retention. This study reveals that the basin-wide nutrient budget, delivery to surface water, and in-stream retention increased during this period. Since 2004, the Three Gorges Reservoir has contributed 5% and 7% of N and P basin-wide retention, respectively. With the dramatic rise in nutrient delivery, even this additional retention was insufficient to prevent an increase of riverine export from 337 Gg N yr−1 and 58 Gg P yr−1 (N:P molar ratio = 13) to 5896 Gg N yr−1 and 381 Gg P yr−1 (N:P molar ratio = 35) to the East China Sea and Yellow Sea (ECSYS). The midstream and upstream subbasins dominate the N and P exports to the ECSYS, respectively, due to various human activities along the river. Our spatially explicit nutrient source allocation can aid in the strategic targeting of nutrient reduction policies. We posit that these should focus on improving the agricultural fertilizer and manure use efficiency in the upstream and midstream and better urban wastewater management in the downstream subbasin.
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•The spatiotemporal changes of N and P sources in YRB were simulated for 1900–2010.•Results indicate 17-fold increase in N export (7-fold increase in P) for 1900–2010.•The impact of the TGR on the whole-basin nutrient retention was limited.•The TGR retention implies an increasing risk of HABs within the reservoir itself.•The ratio of N/P exporting to the coast increased from 13 in 1900 to 35 in 2010.
Homeostatic maintenance is essential for pulp function. Disrupting pulp homeostasis may lead to pulp degeneration, such as fibrosis and calcifications. Sensory nerves constitute a crucial component ...of the dental pulp. However, the precise involvement of sensory nerves in pulp homeostasis remains uncertain. In this study, we observed the short-term and long-term histological changes in the dental pulp after inferior alveolar nerve transection. Additionally, we cultured primary dental pulp cells (DPCs) from the innervated and denervated groups and compared indicators of cellular senescence and cellular function. The results revealed that pulp fibrosis occurred at 2 w after the operation. Furthermore, the pulp area, as well as the height and width of the pulp cavity, showed accelerated reductions after sensory denervation. Notably, the pulp area at 16 w after the operation was comparable to that of 56 w old rats. Sensory denervation induced excessive extracellular matrix (ECM) deposition and increased predisposition to mineralization. Furthermore, sensory denervation promoted the senescence of DPCs. Denervated DPCs exhibited decelerated cell proliferation, arrest in the G2/M phase of the cell cycle, imbalance in the synthesis and degradation of ECM, and enhanced mineralization. These findings indicate that sensory nerves play an essential role in pulp homeostasis maintenance and dental pulp cell fate decisions, which may provide novel insights into the prevention of pulp degeneration.
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