Structure-activity relationship of novel acridone derivatives as antiproliferative agents.

Unlike other DNA topoisomerase II (topo II) inhibitors, our recently identified acridone derivative E17 exerted strong cytotoxic activity by inhibiting topo II without causing topo II degradation and DNA damage, which promoted us to explore more analogues of E17 by expanding its chemical diversification and enrich the structure-activity relationship (SAR) outcomes of acridone-oriented chemotypes. To achieve this goal, 42 novel acridone derivatives were synthesized and evaluated for their antiproliferative efficacies. SAR investigations revealed that orientation and spatial topology of R substituents make greater contributions to the bioactivity, exemplified by compounds E24, E25 and E27, which has provided valuable information for guiding further development of acridone derivatives as promising drug candidates.

E17 exerts anti-tumor activity through inhibiting topo II-mediated chromosomes condensation in CRC cells.

Topo II inhibitors, e.g. etoposide, doxorubicin and mitoxantrone, etc.

Targeted Discovery and Combinatorial Biosynthesis of Polycyclic Tetramate Macrolactam Combamides A-E.

Polycyclic tetramate macrolactams (PoTeMs) are a growing class of natural products with distinct structure and diverse biological activities. By promoter engineering and heterologous expression of the cryptic cbm gene cluster, four new PoTeMs, combamides A-E (1-4), were identified. Additionally, two new derivatives, combamides E (5) and F (6), were generated via combinatorial biosynthesis.

Environmental potentials of policy instruments to mitigate nutrient emissions in Chinese livestock production.

To minimize negative environmental impact of livestock production, policy-makers face a challenge to design and implement more effective policy instruments for livestock farmers at different scales. This research builds an assessment framework on the basis of an agent-based model, named ANEM, to explore nutrient mitigation potentials of five policy instruments, using pig production in Zhongjiang county, southwest China, as the empirical filling. The effects of different policy scenarios are simulated and compared using four indicators and differentiating between small, medium and large scale pig farms.

Will urban expansion lead to an increase in future water pollution loads?--a preliminary investigation of the Haihe River Basin in northeastern China.

Urban expansion is a major driving force changing regional hydrology and nonpoint source pollution. The Haihe River Basin, the political, economic, and cultural center of northeastern China, has undergone rapid urbanization in recent decades. To investigate the consequences of future urban sprawl on nonpoint source water pollutant emissions in the river basin, the urban sprawl in 2030 was estimated, and the annual runoff and nonpoint source pollution in the Haihe River basin were simulated.

Managing manure from China's pigs and poultry: the influence of ecological rationality.

We have investigated manure management practices at three farm scales in Chinese pig and poultry production. The concept of ecological rationality was employed to explore empirically how environmental concerns drive adoption of environmental-friendly manure management technologies at different farm scales. The more developed Rudong County in Jiangsu Province and the less developed Zhongjiang County in Sichuan Province were chosen as cases for study of 258 animal breeders.

[Research of potassium flow and circulation based on substance flow analysis].

Mass of potassium is consumed in the process of crop production, which is the dominating section of potassium flow and circulation in China. However, the degree of self-sufficiency is relatively low due to the deficient domestic resource of potassium. This study analyzed the key links of potassium issues in crop production and consumptive use in 2009 based on substance flow analysis.

Probabilistic ecological risk assessment of polycyclic aromatic hydrocarbons in southwestern catchments of the Bohai Sea, China.

A probability risk assessment was undertaken to study the individual and combined ecological risks induced by six polycyclic aromatic hydrocarbons (PAHs) both in surface water and sediment from southwestern catchments of the Bohai Sea, China. The actual measured PAH concentrations in water and sediment were compared with toxicity effect data (the 10th percentile of predicted no effect concentration) to calculate the risk quotients (RQs) for an individual PAH. The equilibrium partitioning method was applied to estimate toxicity data in sediment.

Quantifying baseline emission factors of air pollutants in China's regional power grids.

Drawing lessons from the clean development mechanism (CDM), this paper developed a combined margin methodology to quantify baseline emission factors of air pollutants in China's regional power grids. The simple average of baseline emission factors of SO2, NOX, and PM2.5 in China's six power grids in 2010 were respectively 1.

Polycyclic aromatic hydrocarbons in river sediments from the western and southern catchments of the Bohai Sea, China: toxicity assessment and source identification.

The concentration, distribution, and origin of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated in river sediments from the western and southern catchments of the Bohai Sea, China. A toxicity assessment of 28 sediment samples collected from 15 main rivers was conducted by utilizing threshold and probable effect concentrations (TEC and PEC, respectively) derived from consensus-based sediment quality guidelines. The concentrations of total PAHs (∑PAH(16)) ranged from 0.

Modeling environmental impacts of urban expansion: a systematic method for dealing with uncertainties.

In a rapidly transitioning China, urban land use has changed dramatically, both spatially and in terms of magnitude; these changes have significantly affected the natural environment. This paper reports the development of an Integrated Environmental Assessment of Urban Land Use Change (IEA-ULUC) model, which combines cellular automata, scenario analysis, and stochastic spatial sampling with the goal of exploring urban land-use change, related environmental impacts, and various uncertainties. By applying the IEA-ULUC model to a new urban development area in Dalian in northeastern China, the evolution of spatial patterns from 1986 to 2005 was examined to identify key driving forces affecting the changing trajectories of local land use.

Environmental risk evaluation to minimize impacts within the area affected by the Wenchuan earthquake.

Earthquakes can be devastating to built infrastructure and the natural environment, as evidenced by the March 2011, M=9.0 earthquake, and subsequent tsunami, in Japan. As seen in the Japanese event, environmental damage caused by secondary disasters (tsunami, leakage from a nuclear reactor) can equal or exceed the impacts of the primary event.

Comparative analysis of environmental carrying capacity of the Bohai Sea Rim area in China.

Environmental carrying capacity is an essential metric for measuring regional sustainability. Although the term "carrying capacity" has been applied for over a century, the concept definition, quantitative methods and comprehensive evaluation remain arguable. This study analyzed the carrying capacity of four environmental elements, including water resources, air, surface water and offshore sea, and integrated them into a comprehensive index to represent overall regional profiles of resources and environment.

Mapping urban environmental noise: a land use regression method.

Forecasting and preventing urban noise pollution are major challenges in urban environmental management. Most existing efforts, including experiment-based models, statistical models, and noise mapping, however, have limited capacity to explain the association between urban growth and corresponding noise change. Therefore, these conventional methods can hardly forecast urban noise at a given outlook of development layout.

Retrofitting conventional primary clarifiers to activated primary clarifiers to enhance nutrient removal and energy conservation in WWTPs in Beijing, China.

Biological nutrient removal requires sufficient carbon source. Meanwhile, the removal of organic matter in wastewater requires energy consumption in the aeration tank. Carbon source for nutrient removal in most wastewater treatment plants with conventional primary clarifier (CPC) is generally insufficient in China.

Operational energy performance assessment system of municipal wastewater treatment plants.

Based on the statistical analysis of operational energy consumption and its influential factors from data of 599 Chinese WWTPs in 2006, it is noticed that the most influential factors include treatment technology adopted, treated sewage amount, removed pollutants amount, etc. Using the conclusion above, this paper sets up an integrated system of operational energy performance assessment for municipal wastewater treatment plants. Combining with result from on-spot research and model simulation, the calculating method of benchmark value and score of 7 energy efficiency indicators grouped into 3 levels is stated.

Silicon alleviates drought stress of rice plants by improving plant water status, photosynthesis and mineral nutrient absorption.

Drought is a major constraint for rice production in the rainfed lowlands in China. Silicon (Si) has been verified to play an important role in enhancing plant resistance to environmental stress. Two near-isogenic lines of rice (Oryza sativa L.

Application of an uncertainty analysis approach to strategic environmental assessment for urban planning.

Urban planning has been widely applied as a regulatory measure to guide a city's construction and management. It represents official expectations on future population and economic growth and land use over the urban area. No doubt, significant variations often occur between planning schemes and actual development; in particular in China, the world's largest developing country experiencing rapid urbanization and industrialization.

[Micro-simulation of firms' heterogeneity on pollution intensity and regional characteristics].

In the same industrial sector, heterogeneity of pollution intensity exists among firms. There are some errors if using sector's average pollution intensity, which are calculated by limited number of firms in environmental statistic database to represent the sector's regional economic-environmental status. Based on the production function which includes environmental depletion as input, a micro-simulation model on firms' operational decision making is proposed.

Probing the mechanisms of silicon-mediated pathogen resistance.

Silicon is the second most abundant mineral element in soil, it has important role in alleviating various environmental stresses and enhancing plant resistance against pathogen, but the exact mechanism by which Si mediates pathogen resistance remains unclear. One of the resistance mechanisms is related to silicon deposition in leaf that acts as a physical barrier to hinder pathogen penetration. But more evidence show that silicon can induce defense responses that are functionally similar to systemic acquired resistance, Si-treated plants can significantly increase antioxidant enzyme activities and the production of antifungal compounds such as phenolic metabolism product, phytoalexins and pathogenesis-related proteins etc.

Regional industrial production's spatial distribution and water pollution control: a plant-level aggregation method for the case of a small region in China.

With fast economic growth, industrial water pollution has been a serious problem ubiquitously in China. More threatening is that lots of economic developing regions still strategically depend on fast industrialization, neglecting the relationship between production's spatial distribution and regional water environmental carrying capacity. As a small region, Deyang City is the objective case.

[Risk assessment of river water quality under accidental pollution based on Bayesian networks].

Risk assessment for accidental pollution plays an important role in river water quality management. Bayesian networks can be applied to represent the relationship between pollution sources and river water quality intuitively. A time sequential Monte Carlo algorithm, integrated with pollution sources model, water quality model and Bayesian reasoning, is developed to quantify river water quality risk under the collective influence of multiple pollution sources.

[Development and application of a multi-species water quality model for water distribution systems with EPANET-MSX].

A conceptual multi-species water quality model for water distribution systems was developed on the basis of the toolkit of the EPANET-MSX software. The model divided the pipe segment into four compartments including pipe wall, biofilm, boundary layer and bulk liquid. The involved processes were substrate utilization and microbial growth, decay and inactivation of microorganisms, mass transfer of soluble components through the boundary layer, adsorption and desorption of particular components between bulk liquid and biofilm, oxidation and halogenation of organic matter by residual chlorine, and chlorine consumption by pipe wall.

[Nitrogen flow in farming-feeding system and its environmental impact in China].

By applying nitrogen flow model for farming-feeding system (NFM-FFS) which integrates soil full nitrogen balance model with inventory analysis for agricultural pollution, nitrogen flow in China farming-feeding systems and its environmental impact are analyzed. In 2003, although surface nitrogen surpluses, nitrogen deficit in agricultural soil system in China is estimated to be 623.9 x 10(4) t, and 13.

[Inventory of regional surface nutrient balance and policy recommendations in China].

By applying OECD surface soil nitrogen balance methodology, the framework, methodology and database for nutrient balance budget in China are established to evaluate the impact of nutrient balance on agricultural production and water environment. Results show that nitrogen and phosphorus surplus in China are 640 x 10(4) t and 98 x 10(4) t respectively, and nitrogen and phosphorus surplus intensity in China are 16.56 kg/hm2 and 2.