Ecological mechanisms of biofilm development in the hybrid sludge-biofilm process: Implications for process start-up and optimization.

The hybrid sludge-biofilm processes have been widely applied for the construction or upgradation of biological wastewater treatment process. Ecological mechanisms of biofilm development remain unclear in the hybrid ecosystem, because of the intricate interactive effects between sludge and biofilms. Herein, the establishment principles of biofilms with distinct coexisting sludge amounts were uncovered by varying sludge retention times (SRTs) from 5 to 40 days in the hybrid process. With the increasing of SRTs, biofilm biomass decreased with the increase of suspended sludge, resulting in lower biofilm proportion. As estimated by the Gompertz growth model, the increased sludge amounts (i.e., higher SRTs of 20 and 40 days) prolonged the initial colonization stage and decreased the specific development rate of biofilms when compared to lower sludge amounts with the shorter SRTs (i.e., 5 and 10 days). Null model analysis demonstrated that deterministic homogenous selection could facilitate the colonization and accumulation of biofilms with less coexisting sludge (SRT of 10 days). However, stochastic ecological drift and homogenizing dispersal dominated the colonization and accumulation stages of biofilms with more coexisting sludge (SRT of 20 days), respectively. The ecological networks reflected that positively-related taxa presented taxonomic relatedness, whereas high inconsistency of taxonomic relatedness was observed among aggregate forms or development stages as affected by varied SRTs. The high incidence of intra-taxa co-occurrence patterns suggested that taxa with similar ecological niches could be specifically selected in biofilms when being exposed with less coexisting sludge. This study uncovered ecological mechanisms of biofilm development driven by varying the SRTs of suspended sludge, which would help to propose appropriate strategies for the efficient start-up and optimization of the hybrid sludge-biofilm system.

Deciphering community assembly and succession in sequencing batch moving bed biofilm reactor: Differentiation between attached and suspended communities.

Elucidating community assembly and succession is crucial to understanding the ecosystem functioning. Herein, the ecological processes underpinning community assembly and succession were studied to uncover the respective ecological functions of attached biofilms and suspended biomass in a sequencing batch moving bed biofilm reactor. Compared with suspended biomass, attached biofilms presented higher relative abundances of Nitrospira (2.94 %) and Nitrosomonas (1.25 %), and contributed to 66.89 ± 11.37 % and 68.11 ± 12.72 % of nitrification and denitrification activities, respectively. The microbial source tracking result demonstrated that early formation of suspended biomass was dominated by the seeding effect of detached biofilms in the start-up period (days 0-30), while self-growth of previous suspended biomass was eventually outcompeted the seeding effect when the reactor stabilized (days 31-120). Null model and ecological network analysis further suggested distinctive ecological processes underpinning the differentiation between attached and suspended communities in the same reactor. Specifically, in the start-up period, positive interactions facilitated early formation of attached (73.84 %) and suspended communities (59.41 %), while homogenous selection (88.89 %) and homogenizing dispersal (65.71 %) governed assembly of attached and suspended communities, respectively. When the reactor stabilized, attached and suspended communities showed low composition turnover as reflected by dominant homogenizing dispersal, while they presented distinctive trends of interspecies interactions. This study sheds light on discrepant ecological processes governing community differentiation of attached biofilms and suspended biomass, which would provide ecological insights into the regulation of hybrid ecosystems.

How Does NIMBYism Influence Residents' Behavioral Willingness to Dispose of Waste in Centralized Collection Points?-An Empirical Study of Nanjing, China.

Residents' low behavioral willingness to dispose of waste in Centralized Collection Points (CCPs) seriously hinders the operational efficiency in waste collection of CCPs regarded as NIMBY ('not in my backyard') facilities. However, fewer researchers notice NIMBY facilities with low hazards. It has been ignored that the NIMBYism may influence behavioral willingness during the operation period persistently. Meanwhile, there is no consistent conclusions on internal factors of waste behavioral willingness, which deserves further study. Therefore, this study took CCPs as a research object and aimed to investigate how NIMBYism influences residents' behavioral willingness to dispose of waste in CCPs. The extended theory of planned behavior and structural equation modeling approach involving 550 respondents were adopted to conduct the analysis. The results revealed that attitude (ß = 0.295, p < 0.001), government trust (ß = 0.479, p < 0.001), and perceived behavioral control (ß = 0.222, p < 0.001) have statistical positive impacts on behavioral willingness to dispose of waste in CCPs. Perceived risk (ß = ‒0.047, p = 0.022 < 0.05) can influence behavioral willingness negatively. Additionally, government trust (ß = 0.726, p < 0.001) exerts a positive impact on attitude. Furthermore, relevant strategies were proposed to enhance residents' behavioral willingness to dispose of waste in CCPs. This study is expected to inspire the government to formulate policies from the aspects of standards and regulations, resident participation, construction, and publicity. It will provide the government instructive suggestions for the smooth operation of CCPs, and ultimately building a healthy and environment friendly society.

Gas permeation through graphdiyne-based nanoporous membranes.

Nanoporous membranes based on two dimensional materials are predicted to provide highly selective gas transport in combination with extreme permeance. Here we investigate membranes made from multilayer graphdiyne, a graphene-like crystal with a larger unit cell. Despite being nearly a hundred of nanometers thick, the membranes allow fast, Knudsen-type permeation of light gases such as helium and hydrogen whereas heavy noble gases like xenon exhibit strongly suppressed flows. Using isotope and cryogenic temperature measurements, the seemingly conflicting characteristics are explained by a high density of straight-through holes (direct porosity of ∼0.1%), in which heavy atoms are adsorbed on the walls, partially blocking Knudsen flows. Our work offers important insights into intricate transport mechanisms playing a role at nanoscale.

A Multi-Agent Platform to Explore Strategies for Age-Friendly Community Projects in Urban China.

BACKGROUND AND OBJECTIVES: Although numerous efforts have been made to promote age-friendly communities (AFCs) in urban China, challenges such as the engagement and management of stakeholders, budget constraints, and policy issues remain. This article describes the work of designing a multi-agent platform (MAP) for the briefing stage of AFC projects. RESEARCH DESIGN AND METHODS: The process to design the MAP is first described, and the components and variables are identified. Then, a case study of a stakeholder consensus formation process is conducted using an agent-based simulation. Next, according to the simulation results, strategies to handle the conflicts arising among the stakeholders of AFC projects are proposed. RESULTS: According to the agent-based simulation conducted, both the initial approval rate and the outside connection rate will affect the stakeholder consensus formation process. Although a higher initial approval rate and a lower outside connection rate may reduce the average convergence time, the results show that 3-5 rounds of information exchange are still needed before a consensus or dissent is formed. DISCUSSION AND IMPLICATIONS: Investors are suggested to communicate with residents and alleviate their concerns regarding AFC projects to facilitate the consensus formation process during the briefing stage of AFC projects; they can also organize activities for residents to exchange information and ideas. The simulation conducted, together with the MAP built in this research, will serve as a reference to help researchers and practitioners further understand the briefing stage and explore efficient strategies for the successful implementation of AFC projects in urban China.

A Scientometric Review of Urban Disaster Resilience Research.

Natural disasters and human-made disasters are threatening urban areas globally. The resilience capacity of the urban system plays an important role in disaster risk response and recovery. Strengthening urban disaster resilience is also fundamental to ensuring sustainable development. Various practices and research for enhancing urban disaster resilience have been carried out worldwide but are yet to be reviewed. Accordingly, this paper gives a scientometric review of urban disaster resilience research by using CiteSpace. The time span (January 2001-January 2021) was selected and divided into three phases based on the number of publications. In addition, according to keyword statistics and clustering results, the collected articles are grouped into four hotspot topics: disaster risk reduction, specific disaster resilience research, resilience assessment, and combination research. The results show that most of the existing research is in the first two categories, and articles in the second and fourth categories both show a high growth rate and could be further research directions. The review indicates that urban disaster resilience is essential for a city's sustainable development. Moreover, the findings provide scholars a full picture of the existing urban disaster resilience research which can help them identify promising research directions. The findings can also help urban government officials and policymakers review current urban disaster management strategies and make further improvements.

Fundamental Triangular Interaction of Electron Trajectory Deviation and P-N Junction to Promote Redox Reactions for the High-Energy-Density Electrode.

Highly efficient redox reaction of active electrode materials is the guarantee for achieving high energy density for energy storage devices. Here, we design a triangle of the electrode material involving the P-N junction between NiO (p-type) and MoO3 (n-type) and electron trajectory deviation between gold nanoparticles with NiO or MoO3. This optimized fundamental triangle structure could facilitate the redox reaction of a metal oxide, and thus the fabricated ternary nanocomposites exhibit excellent electrochemical performance. At a lower current density (0.5 A g-1), the mass specific capacitance of a single electrode can reach 943.3 F g-1, while the NiO/MoO3 tested under the same conditions only has a specific capacitance of 278.9 F g-1. The assembled asymmetric device with activated carbon shows a higher capacitance retention rate of 98.7% after long-term cycling under different current densities, and a maximum energy density of 28.9 W h kg-1 (power density of 400.1 W kg-1). The crucial prerequisite of this strategy is the lower work function of gold nanoparticles compared with active materials, which significantly reduce the activation energy of NiO/MoO3 and the formed P-N junction between p-type NiO with n-type MoO3 in their contact interfaces. This novel design of a triangle structure could be expected to be applied in other materials to develop a kind of energy storage device with excellent electrochemical performance.

Bax Targeted by miR-29a Regulates Chondrocyte Apoptosis in Osteoarthritis.

Osteoarthritis (OA) is a chronic degenerative joint disease, where chondrocyte apoptosis is responsible for cartilage degeneration. Bax is a well-known proapoptotic protein of the Bcl-2 family, involved in a large number of physiological and pathological processes. However, the regulation mechanisms of Bax underlying chondrocyte apoptosis in OA remain unknown. In the present study, we determined the role of Bax in human OA and chondrocyte apoptosis. The results showed that Bax was upregulated in chondrocytes from the articular cartilage of OA patients and in cultured chondrocyte-like ATDC5 cells treated by IL-1ß. Bax was identified to be the direct target of miR-29a by luciferase reporter assay and by western blotting. Inhibition of miR-29a by the mimics protested and overexpression by miR-29a inhibitors aggravated ATDC5 apoptosis induced by IL-1ß. These data reveal that miR-29a/Bax axis plays an important role in regulating chondrocyte apoptosis and suggest that targeting the proapoptotic protein Bax and increasing expression levels of miR-29a emerge as potential approach for protection against the development of OA.

Electrolyte-Philic Electrode Material with a Functional Polymer Brush.

The electrode materials with advanced surface structure and architecture that effectively wet electrolyte and promote (ad/de)sorption of electrolyte ions. It remains a great challenge to improve the electrode surface-wetting properties when submersed in an electrolyte. Herein, we report a novel "electrolyte-philic electrode material (EEM)" involving interconnected hierarchically porous carbon and a grafted electrolyte-philic polymer chain brush by the surface-initiated electrochemical-mediated atom transfer radical polymerization, named EEM- g-polymer, which possesses higher capacity, almost three times larger than that of the pristine one. The selectivity and responsiveness of the polymer brush can be tailored to different electrolyte environments. The EEM- g-polyvinylpyrrolidone (or EEM- g-sodium polystyrenesulfonate) negative electrodes are combined with Ni(OH)2 positive electrodes for the fabrication of asymmetric supercapacitors. Notably, the device presents a maximum energy density of 27.8 W h/kg (or 27.5 W h/kg) when the power density is 351 W/kg (or 314 W/kg), and the capacitance retention is 70.0% (or 65.0%) of the initial capacitance value after 10 000 cycles.

Characterization of Urban Subway Microenvironment Exposure- A Case of Nanjing in China.

Environmental quality in public rail transit has recently raised great concern, with more attention paid to underground subway microenvironment. This research aimed to provide guidance for healthy urban subway microenvironments (sub-MEs) according to comprehensive micro-environmental categories, including thermal environment, air quality, lighting environment, and acoustic environment from both practical and regulation perspectives. Field sampling experiments were conducted in Nanjing Metro Line X (NMLX). Descriptive analysis, correlation analysis and one-way analysis of variance were used to investigate the status quo of urban sub-MEs. A paired samples t-test was then performed to compare among subway station halls, platforms, and in-cabin trains based on integrated sub-MEs. Results show that relative humidity, air velocity, respirable particulate matter (PM10) concentration, and illuminance dissatisfy the requirements in relevant national standards. Significant difference was observed in lighting environment between station hall and platform. It was detected platforms are warmer and more polluted than train cabins. Additionally, subway trains generate main noise on platform which is much louder when leaving than arriving. Protective strategies for sub-ME improvement as well as principles for updating standards were proposed from a proactive point of view. The findings are beneficial for moving towards healthy urban sub-MEs and more sustainable operation of subway systems.

A three-step strategy for decoupling economic growth from carbon emission: Empirical evidences from 133 countries.

To decouple the economic growth and carbon emission has been considered imperative to promote low-carbon economy. Nevertheless, previous studies on decoupling analysis between economic growth and carbon emission were contextualized merely in individual countries rather than the globe, which are insufficient for developing the low-carbon economy as a global target. Carbon intensity (CI), carbon emission per capita (CP), and total carbon emission (TC) serve as three important indicators of the status of regional carbon emission, but only decoupling economic growth from TC was analyzed in previous studies. To close the two gaps, this study aims to investigate the global decoupling statuses of economic growth from not only TC but also CI and CP by using Tapio decoupling index. The decoupling statuses of 133 countries and income-level groups to which they are classified are identified using the data from 2000 to 2014. According to the results, it is observed that economic growth decouples from CI, CP, and TC in sequential order, which is called three-step decoupling. In the period, countries whose economic growth having decoupled from CI, CP, and TC, account for 74%, 35% and 21% respectively. Higher income-level group has the larger proportion of countries having reached their decoupling statuses. These findings may serve as valuable references for policy-makers to understand the current decoupling statuses and make three-step strategies if necessary towards the global low-carbon economy.

A Novel Hierarchical Porous 3D Structured Vanadium Nitride/Carbon Membranes for High-performance Supercapacitor Negative Electrodes.

Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multi-phase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon (VN/C) membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g-1 at 0.5 A g-1 and an excellent rate capability with capacitance retention of 50.5% at 30 A g-1. For the asymmetric device fabricated using Ni(OH)2//VN/C membranes, a high energy density of 43.0 Wh kg-1 at a power density of 800 W kg-1 was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g-1 after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitride-based supercapacitor or other energy storage devices.

Critical Success Factors (CSFs) for the Adaptive Reuse of Industrial Buildings in Hong Kong.

With the economic restructuring during the 1980s and 1990s in Hong Kong, most manufacturing plants were relocated to China and many industrial buildings were left neglected or vacant. At the same time, owing to limited land supply, a shortage of affordable housing has been a problem in Hong Kong for many years. Adaptive reuse of industrial buildings may be a way of solving this problem. However, adaptive reuse is not an easy decision because there are many factors affecting adaptive reuse. Therefore, this paper examines the current situation of adaptive reuse of industrial buildings in Hong Kong and identifies a list of factors affecting the adaptive reuse of industrial buildings. Six factors are considered Critical Success Factors (CSFs). Based on a Principal Component Analysis, 33 factors are grouped into eight principal components, namely, sustainability, economics and finance, the market, changeability, location and neighborhood, culture and public interests, legal and regulatory matters, and the physical condition of the building. The identified CSFs and principal factors provide a useful reference for various stakeholders to have a clear understanding of the adaptive reuse of industrial buildings in Hong Kong, especially for the government to review current policies of adaptive reuse.

Synthesis of ultra-small gold nanoparticles decorated onto NiO nanobelts and their high electrochemical performance.

Herein, ultra-small gold nanoparticles are decorated onto NiO nanobelts using HAuCl4 and Ni(OH)2 nanobelts as precursors via a one-step thermal treatment, and a temperature of 500 °C is used for the decomposition of both precursors at the same time; the amount of gold nanoparticles in the electrode materials ranges from 0 to 17.38 wt%; moreover, the effect of the gold content on the structure and electrochemical performance has been investigated. The results show that the fabricated materials achieve a high specific capacitance of 597 F g-1 with a Au content of 1.54 wt%, and the Au grain size is about 12.0 nm. An asymmetric supercapacitor device was assembled using gold nanoparticle/NiO as the positive electrode and activated carbon as the negative electrode, which exhibited a maximum energy density of 18.0 W h kg-1 and an excellent cycle life, retaining 84% of the initial specific capacitance after 22 000 cycles.

Author Correction: Concise N-doped Carbon Nanosheets/Vanadium Nitride Nanoparticles Materials via Intercalative Polymerization for Supercapacitors.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Up-regulated MiR-27-3p promotes the G1-S phase transition by targeting inhibitor of growth family member 5 in osteosarcoma.

OBJECTIVE: MicroRNAs (miRNAs) play an essential role in regulating malignant progression of tumour cells by inhibiting translation or stability of messenger RNA. However, the expression pattern and regulatory mechanism of miR-27-3p in osteosarcoma remains unclear. METHODS: We examined the expression of miR-27-3p in 5 osteosarcoma cell lines compared with that in 2 normal osteocyte cell lines. Osteosarcoma cells U-2OS and MG-63 were transduced to up-regulate or down-regulate the expression of miR-27-3p. The 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide, or MTT, assay, colony formation assays, BrdUrd labelling, immunofluorescence, anchorage-independent growth ability assay and flow cytometry analysis were used to test the effect of miR-27-3p. Luciferase assays were added to verify the direct relationship between miR-27-3p and the predicted target gene inhibitor of growth family member 5 (ING5). RESULTS: The expression of miR-27-3p was significantly increased in examined osteosarcoma cell lines compared with that in normal osteocyte cell lines. Up-regulation of miR-27-3p significantly accelerated osteosarcoma cell growth via promoting G1-S transition. In addition, the opposite result was observed in miR-27-3p-down-regulated cells. Up-regulation of ING5 significantly attenuated the miR-27-3p-induced proliferation in osteosarcoma cells. CONCLUSIONS: These data suggested that miR-27-3p could promote the G1-S phase transition that leads to proliferation by down-regulating the expression of ING5 in osteosarcoma.

Concise N-doped Carbon Nanosheets/Vanadium Nitride Nanoparticles Materials via Intercalative Polymerization for Supercapacitors.

N-doped carbon nanosheets/vanadium nitride nanoparticles (N-CNS/VNNPs) are synthesized via a novel method combining surface-initiated in-situ intercalative polymerization and thermal-treatment process in NH3/N2 atmosphere. The pH value of the synthesis system plays a critical role in constructing the structure and enhancing electrochemical performance for N-CNS/VNNPs, which are characterized by SEM, TEM, XRD, and XPS, and measured by electrochemical station, respectively. The results show that N-CNS/VNNPs materials consist of 2D N-doped carbon nanosheets and 0D VN nanoparticles. With the pH value decreasing from 2 to 0, the sizes of both carbon nanosheets and VN nanoparticles decreased to smaller in nanoscale. The maximum specific capacitance of 280 F g-1 at the current density of 1 A g-1 for N-CNS/VNNPs is achieved in three-electrode configuration. The asymmetric energy device of Ni(OH)2||N-CNS/VNNPs offers a specific capacitance of 89.6 F g-1 and retention of 60% at 2.7 A g-1 after 5000 cycles. The maximum energy density of Ni(OH)2 ||N-CNS/VNNPs asymmetric energy device is as high as 29.5 Wh kg-1.

Nanocomposites based on hierarchical porous carbon fiber@vanadium nitride nanoparticles as supercapacitor electrodes.

In this study, a hybrid electrode material for supercapacitors based on hierarchical porous carbon fiber@vanadium nitride nanoparticles is fabricated using the method of phase-separation mediated by the PAA-b-PAN-b-PAA tri-block copolymer. In the phase-separation procedure, the ionic block copolymer self-assembled on the surface of carbon nanofibers, and is used to adsorb NH4VO3. Thermal treatment at controlled temperatures under an NH3 : N2 atmosphere led to the formation of vanadium nitride nanoparticles that are distributed uniformly on the nanofiber surface. By changing the PAN to PAA-b-PAN-b-PAA ratio in the casting solution, a maximum specific capacitance of 240.5 F g-1 is achieved at the current density of 0.5 A g-1 with good rate capability at a capacitance retention of 72.1% at 5.0 A g-1 in an aqueous electrolyte of 6 mol L-1 KOH within the potential range of -1.10 to 0 V (rN/A = 1.5/1.0). Moreover, an asymmetric supercapacitor is assembled by using the hierarchical porous carbon fiber@vanadium nitride as the negative electrode and Ni(OH)2 as the positive electrode. Remarkably, at the power density of 400 W kg-1, the supercapacitor device delivers a better energy density of 39.3 W h kg-1. It also shows excellent electrochemical stability, and thus might be used as a promising energy-storage device.

A study of best practices in promoting sustainable urbanization in China.

In the past twenty years, various sustainable urban development policies and methods had been implemented within China, such that sustainable urbanization is now more widely accepted. Some of these policies and methods have been found to be successful in improving the sustainability of cities in China. Those practices can be defined as the best practices of sustainable urbanization, which can provide useful references for future urban developments. However, few existing studies examine how to learn from these best practices. Combining the methods of content analysis and social network analysis, this paper conducts a comprehensive study on 150 best practices of sustainable urbanization in China. The methods and outcomes of the 150 best practices are identified. The research findings demonstrate the statistics of categories, methods and outcomes of the 150 best practices and the main adopted methods. The achieved outcomes in different regions of China are also presented.

Novel Hybrid Nanoparticles of Vanadium Nitride/Porous Carbon as an Anode Material for Symmetrical Supercapacitor.

ABSTRACT: Hybrid materials of vanadium nitride and porous carbon nanoparticles (VN/PCNPs) were fabricated by a facile pyrolysis process of vanadium pentoxide (V2O5) xerogel and melamine at relatively low temperature of 800 °C for supercapacitor application. The effects of the feed ratio of V2O5 to melamine (r), and nitrogen flow rate on the microstructure and electrochemical performance were also investigated. It was found that the size of the as-synthesized nanoparticles is about 20 nm. Both r value and N2 flow rate have enormous impacts on morphology and microstructure of the nanoparticle, which correspondingly determined the electrochemical performance of the material. The VN/C hybrid nanoparticles exhibited high capacitive properties, and a maximum specific capacitance of 255.0 F g-1 was achieved at a current density of 1.0 A g-1 in 2 M KOH aqueous electrolyte and the potential range from 0 to -1.15 V. In addition, symmetrical supercapacitor fabricated with the as-synthesized VN/PCNPs presents a high specific capacitance of 43.5 F g-1 at 0.5 A g-1 based on the entire cell, and an energy density of 8.0 Wh kg-1 when the power density was 575 W kg-1. Even when the power density increased to 2831.5 W kg-1, the energy density still remained 6.1 Wh kg-1.