Roxarsone biotransformation by a nitroreductase and an acetyltransferase in Pseudomonas chlororaphis, a bacterium isolated from soil.

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, Rox), a widely used organoarsenical feed additive, can enter soils and be further biotransformed into various arsenic species that pose human health and ecological risks. However, the pathway and molecular mechanism of Rox biotransformation by soil microbes are not well studied. Therefore, in this study, we isolated a Rox-transforming bacterium from manure-fertilized soil and identified it as Pseudomonas chlororaphis through morphological analysis and 16S rRNA gene sequencing. Pseudomonas chlororaphis was able to biotransform Rox to 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA), N-acetyl-4-hydroxy-m-arsanilic acid (N-AHPAA), arsenate [As(V)], arsenite [As(III)], and dimethylarsenate [DMAs(V)]. The complete genome of Pseudomonas chlororaphis was sequenced. PcmdaB, encoding a nitroreductase, and PcnhoA, encoding an acetyltransferase, were identified in the genome of Pseudomonas chlororaphis. Expression of PcmdaB and PcnhoA in E. coli Rosetta was shown to confer Rox(III) and 3-AHPAA(III) resistance through Rox nitroreduction and 3-AHPAA acetylation, respectively. The PcMdaB and PcNhoA enzymes were further purified and functionally characterized in vitro. The kinetic data of both PcMdaB and PcNhoA were well fit to the Michaelis-Menten equation, and nitroreduction catalyzed by PcMdaB is the rate-limiting step for Rox transformation. Our results provide new insights into the environmental risk assessment and bioremediation of Rox(V)-contaminated soils.

The redevelopment mode selection framework for Third Front Brownfields in China.

Unlike most brownfields located in the urban center, there is a kind of special brownfields produced in the Third Front Construction (TFC) period of China, and in turn they are named the Third Front Brownfield (TFB) in this paper. In addition to commercial value, other values should also be considered when TFBs are redeveloped, which makes they may need a specific protective reuse way and their revitalization process is relatively slower. Therefore, it is of great significance to study the redevelopment mode of TFBs. Accordingly, this paper presents a redevelopment mode selection framework to support stakeholders' investment decision-making and facilitate the reuse of TFBs. First, a previous case base including two sets is developed to conduct experience mining. In specific, an attribute set and a TFB redevelopment mode set of previous successful cases are established through literatures and expert interviews. Second, the weights of abovementioned attributes are determined by using the G1 method. Third, a concept of matching rate is defined based on the Attribute Similarity Model (ASM) to search the similarity between the new TFB and previous cases so that stakeholders can get advice on the redevelopment of the new TFB. A case study is conducted to show the effectiveness of the proposed framework and some policy suggestions are made according to the study process.

The Carbon Emission Assessment of a Building with Different Prefabrication Rates in the Construction Stage.

The utilization of prefabricated components is taken as a potential way to reduce carbon emissions from the construction industry, and the prefabrication rate may be a factor that influences the mitigation efficiency. This study develops an assessment method to compare carbon emissions of a building in the construction stage when it is built with multiple different prefabrication rates. Firstly, two carbon sources (building materials and machineries) and three construction sub-phases (production of materials and components, transportation, and on-site construction) are determined to clarify the calculation boundary. Then, a carbon emission measurement model for prefabricated buildings in the construction stage is developed by using a process-based method. A dormitory building in Chongqing, China, is selected to conduct a case study to show the application of the provided model. The result shows that the carbon emission of prefabricated buildings is higher compared to that of traditional cast-in situ buildings. Moreover, the emission of prefabricated buildings decreased slightly with the increase in the prefabrication rate. A detailed discussion is followed to investigate the reason why the carbon emission does not decrease with the utilization of prefabricated units. Based on the discussion, some suggestions are given to improve the carbon emission reduction efficiency of prefabrication techniques.

Evaluating the Comprehensive Benefit of Urban Renewal Projects on the Area Scale: An Integrated Method.

Globally, the challenges facing cities regarding urban decay, insufficient urban function, and fragmented urban development are enormous. Under this context, urban renewal provides opportunities to address these challenges and enhance urban sustainability. Thus, promoting urban renewal projects and improving their performance is a global topic. In many circumstances, urban renewal is planned and initiated on the project scale, but on the area scale, overall coordination of the projects can bring about comprehensive benefits to urban areas on a macro view. In practice, it still lacks a systematic evaluation approach to obtain a clear picture of such comprehensive benefits. In academia, the existing research studies are mainly focused on single-project evaluation. An integrated framework that provides a holistic assessment of area-scale project benefits is missing. Few fully consider the coupling coordination benefits between several urban renewal projects from an area-scale perspective. Thus, this paper aims to propose a framework for integrating an indicator evaluation system through a hybrid entropy weight method with Back Propagation (BP) neural network methods to evaluate the comprehensive benefit of urban renewal projects on the area scale, which is the level at which most development area-scale renewal projects take place in a city. The feasibility and effectiveness of this proposed framework are then verified in a case study of Chongqing, China. The results indicate that the proposed method that integrated multi-project characteristics can contribute to a bigger picture of benefit evaluation of urban renewal based on an area scale perspective. This therefore provides not only guidance for urban planners and policymakers to make better decisions, but also new insight for benefit evaluation in the field of urban development.

Co-Benefits Analysis of Buildings Based on Different Renewal Strategies: The Emergy-Lca Approach.

Many cities have encountered challenges associated with rapid urban development, population growth and aging, in which urban renewal has become a promising option. Different renewal strategies, such as redevelopment, refurbishment and conservation, not only contributes to quality improvement and energy consumption reduction of dilapidated urban area, but also to greenhouse gas (GHG) emissions mitigation. Such integrated benefits are often termed as co-benefits. However, choosing the most co-benefits strategy to adopt requires a holistic understanding of social-economic and environmental aspects, which has been less reported in the existing literature. Under such circumstance, this article aims to shed light on the co-benefits of different renewal strategies by adopting the Emergy-Life cycle assessment method. Then, the method is applied to one case study of the refurbishment of an educational building located in Chongqing, China. Resource allocation, CO2 emissions and emergy-based indicators are calculated to assess the co-benefits during a 60-year research period, to compare the impacts of the complete demolition followed by a new one (rebuilding strategy) and the refurbishing of the existing building (refurbishment strategy). The case study shows that the annual emergy in the O&M phase of rebuilding strategy and refurbishment strategy were lower than existing building. Rebuilding and refurbishment strategies released approximately 59.1% and 80.6%, respectively, of the total CO2 emissions that would be produced by the existing building. The results reveal that substantial environmental benefits can be obtained in both the refurbishment and rebuilding strategies. On the other hand, it can be concluded that the emergy yield ratio (EYR) for the rebuilding strategy is higher than refurbishment strategy, which demonstrate the better performance of refurbishment considering that less resources are required to generate greater benefits. In addition, the value of environmental loading ratio (ELR) and emergy sustainability index (ESI) also suggests that the refurbishment strategy performs better from the perspective of the environment. Thereby, the refurbishment strategy is more suitable than the rebuilding strategy. Findings from this study can be useful to urban planners and decision-makers in choosing the most suitable strategy to improve the quality of existing buildings.

Evaluating the Environmental Impact of Construction within the Industrialized Building Process: A Monetization and Building Information Modelling Approach.

Industrialization has been widely regarded as a sustainable construction method in terms of its environmental friendliness. However, existing studies mainly consider the single impact of greenhouse gas emissions or material consumption in the construction process of industrialized buildings, and pay less attention to ecological pollution and community interest, which leads to an insufficient understanding. There is an urgent need to systematically carry out accurate assessment of comprehensive construction environmental impact within industrialized building processes. Various methods, including face-to-face interviews, field research and building information modeling (BIM), were used for data collection. Four categories selected for the study included resource consumption, material loss, ecological pollution, and community interest. A life cycle assessment (LCA) model, namely input-process-output model (IPO), is proposed to analyze the construction environmental impact of the standard layer of industrialized buildings from four life cycle stages, namely, transportation, stacking, assembly and cast-in-place. The monetization approach of willingness to pay (WTP) was applied to make a quantitative comparison. Results reveal that the assembly stage has the largest impact on the environment at 66.13% among the four life cycle stages, followed by transportation at 16.39%, stacking at 10.29%, and cast-in-place at 7.19%. The key factors include power consumption, noise pollution, material loss, fuel consumption and component loss, which altogether account for more than 85% of the total impact. Relevant stakeholders can conduct their project using the same approach to determine the construction environmental performance and hence introduce appropriate measures to mitigate the environmental burden.

Quantifying construction and demolition waste: an analytical review.

Quantifying construction and demolition (C&D) waste generation is regarded as a prerequisite for the implementation of successful waste management. In literature, various methods have been employed to quantify the C&D waste generation at both regional and project levels. However, an integrated review that systemically describes and analyses all the existing methods has yet to be conducted. To bridge this research gap, an analytical review is conducted. Fifty-seven papers are retrieved based on a set of rigorous procedures. The characteristics of the selected papers are classified according to the following criteria - waste generation activity, estimation level and quantification methodology. Six categories of existing C&D waste quantification methodologies are identified, including site visit method, waste generation rate method, lifetime analysis method, classification system accumulation method, variables modelling method and other particular methods. A critical comparison of the identified methods is given according to their characteristics and implementation constraints. Moreover, a decision tree is proposed for aiding the selection of the most appropriate quantification method in different scenarios. Based on the analytical review, limitations of previous studies and recommendations of potential future research directions are further suggested.

Clinical performance characteristics of the Cervista HPV HR test kit in cervical cancer screening in China.

OBJECTIVE: A multicenter clinical trial was performed to evaluate and validate the performance of Cervista HPV HR test and to establish its effectiveness in identifying women at risk of having cervical intraepithelial neoplasia 2 (CIN 2) or higher grade (CIN 2+) in the Chinese population. MATERIALS AND METHODS: Residual ThinPrep Pap Test samples from women who are negative for intraepithelial lesion or malignancy (NILM) and atypical squamous cells of undetermined significance (ASCUS) or higher grade cytology were tested for high-risk human papillomavirus (HPV). The HPV test results were compared with histology results to determine the clinical sensitivity, specificity, positive predictive value, and negative predictive value of Cervista HPV HR for CIN 2+. The analytical accuracy of Cervista HPV HR compared with consensus HPV L1 polymerase chain reaction (PCR)/sequencing was also determined. RESULT: A total of 1,064 subjects were enrolled, including 544 with NILM cytology and 520 with ASCUS or higher grade cytology. Complete data sets including cytology, high-risk HPV test, colposcopy, and histology results for all subjects with ASCUS or higher grade were included in the analysis. The positive rate of Cervista HPV HR was 12.5% in patients with NILM and 69.04% in patients with ASCUS or higher grade. The overall percentage agreement between Cervista HPV HR and PCR with bidirectional sequencing was 86.26%, with positive percentage agreement and negative percentage agreement being 93.4% and 83.3%, respectively. In the overall population, the Cervista HPV HR positivity rate was 38.96% compared with 29.08% for PCR/sequencing. The clinical sensitivity and specificity for CIN 2+ of Cervista HPV HR were 98.50% and 68.21%, respectively. The negative and positive predictive values were 99.69% and 30.68%, respectively. CONCLUSIONS: The Cervista HPV HR test, performed on ThinPrep Pap Test samples, has the clinical performance characteristics required by China for use as part of routine cervical cancer screening.

[High-risk human papilloma virus DNA detection kit (cervista HPV HR) should be highly validated clinically in cervical cancer screening programs].

OBJECTIVE: The aim of this study is to evaluate the clinical significance of High-risk Human Papilloma virus DNA Detection Kit (Cervista HPV HR) designed to the utilized in cervical cancer screening programs. METHODS: The investigation for Cervista HPV HR test is designed to detect 437 residual liquid-based cytology specimens collected during routine liquid-based Pap tests at standard care vistis and to identify the presence of HR HPV. We compared Cervista HPV HR Test against standard PCR, in order to examine the performance of Cervista HPV HR Test in populations with cervical intraepithelial neoplasia grade 2+ (CIN 2, CIN 3 and Cancer, CIN 2+), and the capabilities of A5/A6, A7, A9 oligonucleotides of Cervista for predicting CIN2+. RESULTS: The accuracy of Cervista compared to PCR with bi-directional sequencing was 88.26%. The positive percent of Cervista HPV HR Test and PCR were 38.96% and 29.08%, respectively. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of Cervista HPV HR Test for the detection of CIN2+ were 98.46%, 58.49%, 99.54% and 29.68%, respectively. The A9 oligonucleotides positivity percent was significantly higher in CIN2 + (odds ratio: 24.037, 95% CI: 10.086 - 57.283). CONCLUSION: The Cervista HPV HR test can be clinically used for detecting HR HPV types during routine cervical cancer screening. A9 oligonucleotides were also strongly associated with CIN2+ diagnosis, which is improtant in cervical cancer screening for triage to colposcopy.

A comprehensive framework for assessing and selecting appropriate scaffolding based on analytic hierarchy process.

PROBLEM: Bamboo scaffolding has been widely used in South China, Hong Kong, and Southeast Asia for many years. Bamboo scaffolding is more economical, but its safety record is relatively poor. Conversely, metal scaffolding is more expensive, but its use in these regions has increased in recent years because it is relatively safe. The assessment and selection of the most appropriate type of scaffolding for a particular construction project is always a concern for project managers. METHOD: This paper suggests a comprehensive assessment framework that enables project managers to take a number of major quantitative and qualitative factors into consideration when making scaffolding decisions. This framework is based on the Analytic Hierarchy Process methodology and a survey among project managers in Hong Kong. RESULTS: The research reveals that the overall performance of metal scaffolding is believed to be better than bamboo scaffolding. A sensitivity analysis has also been conducted to investigate the impact of various factors on the final decisions. IMPACT ON INDUSTRY: The proposed assessment framework can be used as a supporting tool for project managers in the selection of scaffolding for their projects.