The effect of Si on the growth kinetics of intermetallic compounds during the reaction of solid iron and molten aluminum was investigated with a scanning electron microscope coupled with an energy dispersive X-ray spe...The effect of Si on the growth kinetics of intermetallic compounds during the reaction of solid iron and molten aluminum was investigated with a scanning electron microscope coupled with an energy dispersive X-ray spectroscope, and hot-dip aluminized experiments. The results show that the intermetallic layer is composed of major Fe2Al5 and minor FeAl3. The Al-Fe-Si ternary phase, rl/rg, is formed in the Fe2Al5 layer. The tongue-like morphology of the Fe2Als layer becomes less distinct and disappears finally as the content of Si in aluminum bath increases. Si in the bath improves the prohibiting ability to the growth of Fe2Als and FeAl3. When the contents of Si are 0, 0.5%, 1.0%, 1.5%, 2.0% and 3.0%, the activation energies of Fe2Al5 are evaluated to be 207, 186, 169, 168, 167 and 172 kJ/mol, respectively. The reduction of the activation energy might result from the lattice distortion caused by Si atom penetrating into the Fe2Al5 phase. When Si atom occupies the vacancy site, it blocks easy diffusion path and results in the disappearance of tongue-like morphology.展开更多
In comparison with integrated pest management and chemical control, the authors put forward a new strategy of forest pest control, named ecological control of forest pest (ECFP). This paper reviewed the development ...In comparison with integrated pest management and chemical control, the authors put forward a new strategy of forest pest control, named ecological control of forest pest (ECFP). This paper reviewed the development history, summarized the concept and principles of ECFP, discussed the technology and methods of ECFP, and evaluated the ECFP and its application conditions.展开更多
Biology is a rich source of great ideas that can inspire us to find successful ways to solve the challenging problems in engineering practices including those in the chemical industry. Bio-inspired chemical engineerin...Biology is a rich source of great ideas that can inspire us to find successful ways to solve the challenging problems in engineering practices including those in the chemical industry. Bio-inspired chemical engineering(Bio Ch E)may be recognized as a significant branch of chemical engineering. It may consist of, but not limited to, the following three aspects: 1) Chemical engineering principles and unit operations in biological systems; 2) Process engineering principles for producing existing or developing new chemical products through living ‘devices';and 3) Chemical engineering processes and equipment that are designed and constructed through mimicking(does not have to reproduce one hundred percent) the biological systems including their physical–chemical and mechanical structures to deliver uniquely beneficial performances. This may also include the bio-inspired sensors for process monitoring. In this paper, the above aspects are defined and discussed which establishes the scope of BioChE.展开更多
Phosphorus(P),as a limiting nutrient,plays a crucial role in the mountainous ecosystem development.Its biogeochemical cycle in mountainous ecosystems determines the bioavailability and sustainable supply of P,and thus...Phosphorus(P),as a limiting nutrient,plays a crucial role in the mountainous ecosystem development.Its biogeochemical cycle in mountainous ecosystems determines the bioavailability and sustainable supply of P,and thus becomes a crucial process which needs to be fully understood and described for ecological and environmental conservation.However,most of research about P biogeochemical processes has been carried out in aquatic environment and agronomic field,but rare researches have been done in mountain ecosystem.In the present review,we summarize researches on P biogeochemical cycle concerning mountain ecosystem in recent decades,including rock weathering,the release,transformation and bioavailability of P,interactions between the P biological cycle and microbial and plant life,as well as the development of models.Based on the state of art,we propose the future work on this direction,including the integration of all these research,the development of a practical model to understand the P biogeochemical cycle and its bioavailability,and to provide a reference for ecological and environmental conservation of mountainous ecosystems and lowland aquatic systems.展开更多
In order to investigate the effect of the surface morphology and resistance of the TiO2 semiconductor on current output,TiO2 nanotube array bio-anodes(TNA)are synthesized at different electrolyte temperatures,thereby ...In order to investigate the effect of the surface morphology and resistance of the TiO2 semiconductor on current output,TiO2 nanotube array bio-anodes(TNA)are synthesized at different electrolyte temperatures,thereby changing the length and surface roughness of the nanotubes.When the anodizing temperature is increased from 30 to 75℃,the length of the nanotubes increases from 1.459 to 4.183μm,which hinders the transfer of extracellular electrons to the electrodes.On the other hand,the surface roughness of TNA is significantly improved at higher temperatures,which is conducive to electron transfer.Therefore,samples processed at 45℃have the best current output performance.Compared with the treatment at 30℃under anodization,samples processed at 45℃can balance the resistance and roughness and have a higher electron transfer rate;the current output density of which is increased by 1.5 times,and the decolorization rate is increased by 0.8 times.Therefore,proper TNA surface morphology can improve the current output and the potential of wastewater treatment.展开更多
Ocean acidification leads to changes in physiological and immune responses of bivalves, but the eff ect on the immune enzyme activities of the Manila clam, R uditapes philippinarum, when the pH is lower than the norma...Ocean acidification leads to changes in physiological and immune responses of bivalves, but the eff ect on the immune enzyme activities of the Manila clam, R uditapes philippinarum, when the pH is lower than the normal value has not been studied in detail. In this study, experiments were conducted to determine how pH(7.4, 7.7, 8.0) affects the immune enzyme activities in the gill and hemocytes of the Manila clam. Membrane stability and phagocytosis increased with decrease of pH from 8.0 to 7.7 and then decreased at pH 7.4. The total protein content in the hemocytes and gills decreased with decreasing pH. Lysozyme content in the hemocytes increased with decreasing pH, and the diff erences were significant among the different pH groups(P < 0.05). Adenosine triphosphatase activity at pH 7.4 was significantly higher than in the other two groups, but no significant diff erence was observed between pH 7.7 and 8.0. Catalase activity decreased from pH 8.0 to 7.7 and then increased at pH 7.4, and the dif ferences were significant among the experimental groups( P < 0.05). These findings provide valuable information about the immune response of R. philippinarum to reduced water pH and insights for future research investigating exposure of bivalves to elevated CO_2 conditions.展开更多
Despite the fact that miombo woodland soils have significant implications in global climate change processes, few studies have been done to characterize and classify the soils of the miombo woodland ecosystem of Tanza...Despite the fact that miombo woodland soils have significant implications in global climate change processes, few studies have been done to characterize and classify the soils of the miombo woodland ecosystem of Tanzania. The current study was carried out to map and classify soils of Kitonga Forest Reserve, which is a typical miombo woodland ecosystem, in order to generate relevant information for their use and management. A representative study area of 52 km2 was selected and mapped at a scale of 1:50,000 on the basis of relief. Ten representative soil profiles were excavated and described using standard methods. Soil samples were taken from genetic soil horizons and analyzed in the laboratory for physico-chemical characteristics using standard methods. Using field and laboratory analytical data, the soils were classified according to the FAO-World Reference Base (FAO-WRB) for Soil Resources system as Cambisols, Leptosols and Fluvisols. In the USDA-NRCS Soil Taxonomy system the soils were classified as Inceptisols and Entisols. Topographical features played an important role in soil formation. The different soil types differed in physico-chemical properties, hence exhibit differences in their potentials, constraints and need specific management strategies. Texture varied from sandy to different loams; pH from 5.1 to 5.9; organic carbon from 0.9 g/kg to 20 g/kg; and CEC from 3 cmol/(+)kg to 24 cmol/(+)kg. Sustainable management of miombo woodlands ecosystem soils requires reduced deforestation and reduced land degradation.展开更多
Microcystins(MCs) are cyclic hepatotoxic peptides produced by the bloom-forming cyanobacterium Microcystis and present a public health hazard to humans and livestock. The removal of MCs from contaminated water with po...Microcystins(MCs) are cyclic hepatotoxic peptides produced by the bloom-forming cyanobacterium Microcystis and present a public health hazard to humans and livestock. The removal of MCs from contaminated water with powdered activated carbon(PAC) has been employed as a simple and economic treatment strategy. In this study, PAC-Fe(Ⅲ) was prepared and utilized for the fast and efficient removal of MCs from water. PAC-Fe(Ⅲ) exhibited superior microcystin-LR(MC-LR) removal capacity and efficiency compared to the unmodified PAC. The MC-LR removal efficiency of PAC-Fe(Ⅲ) increased with decreasing p H within the pH range of 4.3 to 9.6. PAC-Fe(Ⅲ) could be reused for 3 times by methanol elution while the MC-LR removal efficiency was still over 70 percent. The removal efficiency was positively correlated to the ionic strength of water and negatively correlated to alkalinity. Natural organic matter(NOM) such as humic acid(HA) and salicylic acid(SA) generated low interference with MC-LR adsorption by PAC-Fe(Ⅲ). The complexation reaction between Fe^(3+) in PAC-Fe(Ⅲ) and the functional groups of MCLR was suggested as the key mechanism of MC-LR removal by PAC-Fe(Ⅲ). The results suggest that Femodified PAC is a promising material for the treatment of MC-contaminated waters.展开更多
The community of Figuig is located in a desert area, east of Morocco. It is characterized by an arid climate. Part of the aquifers of the area has a high salinity which creates even worst conditions for the use of the...The community of Figuig is located in a desert area, east of Morocco. It is characterized by an arid climate. Part of the aquifers of the area has a high salinity which creates even worst conditions for the use of the scarce water available in the area. Therefore, it is essential to develop new water resources, especially for agriculture. For this reason, reclaiming wastewater for agricultural use is an essential strategy to increase water resources. The studied system is a wastewater treatment plant (WWTP) with stabilisation ponds; it treats a part of the wastewater of Figuig. The monitoring of the WWTP will allow to the physico-chemical and biological characterization of the treated water, and then, to verify two principal points: (1) the physico-chemical and pathogen parasites elimination; (2) the possibility of the treated water reuse in agricultural irrigation. The reductions recorded at the WWTP show a relatively preferment operation with an average decrease of 3.17 Ulog for faecal coliforms and 50-60% for organic matter. It was observed that the taxonomic density is slow in the WWTP; observed species are generally Cyanobacteria, Euglénophycea and Chlorophycea characteristic of eutrophic water sources.展开更多
In Antarctica, the marine ecosystem is dynamically interrelated with the terrestrial ecosystem. An example of the link between these two ecosystems is the biogeochemical cycle of phosphorus. Bio- vectors, such as peng...In Antarctica, the marine ecosystem is dynamically interrelated with the terrestrial ecosystem. An example of the link between these two ecosystems is the biogeochemical cycle of phosphorus. Bio- vectors, such as penguins, transport phosphorus from sea to land, play a key role in this cycle. In this paper, we selected three colonies of penguins, the most important seabirds in Antarctica, and computed the annual quantity of phosphorus transferred from sea to land by these birds. Our results show that adult penguins from colonies at Ardley Island, the Vestfold Hills, and Ross Island could transfer phosphorus in the form of guano at up to 12 349, 167 036, and 97 841 kg/a, respectively, over their breeding period. These quantities are equivalent to an annual input of 3.96× 10^9-1.63 × 10^10 kg of seawater to the land of Antarctica. Finally, we discuss the impact of phosphorus on the ice-flee areas of the Antarctica.展开更多
The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only...The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only yields a steady state. Also,. the performance of such oscillations shows two maxima with the variation of the system size, indicating the occurrence of system size resonance. This behavior is found to be intimately connected with the canard phenomenon. Interestingly, it is also found that one of the optimal system sizes matches well with the real cell size, and such a match is robust to the variation of the control parameters.展开更多
A coupled system consisting of an upflow membrane-less microbial fuel cell (upflow ML-MFC) and a photobioreactor was developed, and its effectiveness for continuous wastewater treatment and electricity production was ...A coupled system consisting of an upflow membrane-less microbial fuel cell (upflow ML-MFC) and a photobioreactor was developed, and its effectiveness for continuous wastewater treatment and electricity production was evaluated. Wastewater was fed to the upflow ML-MFC to remove chemical oxygen demand (COD), phosphorus and nitrogen with simultaneous electricity generation. The effluent from the cathode compartment of the upflow ML-MFC was then continuously fed to an external photobioreactor for removing the remaining phosphorus and nitrogen using microalgae. Alone, the upflow ML-MFC produces a maximum power density of 481 mW/m 3 , and obtains 77.9% COD, 23.5% total phosphorus (TP) and 97.6% NH4+-N removals. When combined with the photobioreactor, the system achieves 99.3% TP and 99.0% NH4+-N total removal. These results show both the effectiveness and the potential application of the coupled system to continuously treat domestic wastewater and simultaneously generate electricity and biomass.展开更多
118 clinical strains of Shigella were serotyped, in which 116 strains were tested to be S. flexneri. The susceptibilities of the S .flexneri strains to quinolones were measured by the disk-diffusion method. It was fou...118 clinical strains of Shigella were serotyped, in which 116 strains were tested to be S. flexneri. The susceptibilities of the S .flexneri strains to quinolones were measured by the disk-diffusion method. It was found that most S .flexneri strains were susceptible to norfloxacin and ciprofloxacin, but resistant to nalidixic acid. To study the correlation between gyrA mutations and quinolones resistance, a fragment within the gyrA gene was amplified by PCR. The SSCP (Single-Strand Conformation Polymorphism) analysis was applied to detect mutations in PCR products of different strains. The mutations were then confirmed by DNA sequencing. Altogether, two types of mutation were revealed, in which one type was single mutation ( C42-T), and the other was double mutations ( C42-T and A54- G). By statistical analysis, C42-T (encoding Ser83-keu substitution) was shown to have correlation with nalidixic-acid resistance in the clinical strains of Shigella, while A54-G (encoding Asp87-Gly substitution) was shown to have correlations with both norfloxacin resistance and ciprofloxacin resistance.展开更多
Recent observations support an emerging paradigm that climate variability dominates nutrient enrichment in costal eco-systems, which can explain seasonal and inter-annual variability of phytoplankton community composi...Recent observations support an emerging paradigm that climate variability dominates nutrient enrichment in costal eco-systems, which can explain seasonal and inter-annual variability of phytoplankton community composition, biomass (Chl-a), and primary production (PP). In this paper, we combined observation and modeling to investigate the regulation of phytoplankton dynamics in Chesapeake Bay. The year we chose is 1996 that has high river runoff and is usually called a 'wet year'. A 3-D physical-biogeochemical model based on ROMS was developed to simulate the seasonal cycle and the regional distributions of phytoplankton biomass and primary production in Chesapeake Bay. Based on the model results, NO3 presents a strong contrast to the river nitrate load during spring and the highest concentration in the bay reaches around 80 mmol Nm-3 . Compared with the normal year, phytoplankton bloom in spring of 1996 appears in lower latitudes with a higher concentration. Quantitative comparison between the modeled and observed seasonal averaged dissolved inorganic nitrogen concentrations shows that the model produces reliable results. The correlation coefficient r2 for all quantities exceeds 0.95, and the skill parameter for the four seasons is all above 0.95.展开更多
The implementation of multiple enzymes for chemical production in a cell‐free scenario is an emerging field in biomanufacturing.It enables the redesign and reconstitution of new enzymatic routes for producing chemica...The implementation of multiple enzymes for chemical production in a cell‐free scenario is an emerging field in biomanufacturing.It enables the redesign and reconstitution of new enzymatic routes for producing chemicals that may be hard to obtain from natural pathways.Although the construction of a cell‐free multienzyme system is highly flexible and adaptable,it is challenging to make all enzymatic reactions act in concert.Recently,modular construction has been conceptual‐ized as an effective way to harmonize diverse enzymatic reactions.In this review,we introduce the concept of a multienzyme module and exemplify representative modules found in Nature.We then categorize recent developments of synthetic multienzyme modules into main‐reaction modules and auxiliary modules according to their roles in reaction routes.We highlight four main‐reaction mod‐ules that can perform carbon metabolism,carbon assimilation,protein glycosylation and nonribo‐somal peptide synthesis,and exemplify auxiliary modules used for energy supply,protection and reinforcement for main reactions.The reactor‐level modularization of multienzyme catalysis is also discussed.展开更多
This project describes an integral solution to implement a module-based platform for the control of all the automated systems inside a house and a remote control of the entrance access to this house. A biometrical acc...This project describes an integral solution to implement a module-based platform for the control of all the automated systems inside a house and a remote control of the entrance access to this house. A biometrical access based on the hand veins has been used with a complete local and remote access control system. A technologically ergonomic way to control the house, as well as some biological signal monitoring has also been developed. This has been done by knowing the physical restrictions of the collective who will live in the house. A set of different sensors will control this operation. In order to control all the home automated systems coordinate the whole platform using the TV remote. This project will implement the OSGI standard. This implementation should ensure the system scalability in terms of including new hardware. In addition, a ZibBee networking system has been developed to enable communication between all the sensors, systems and the central processor.展开更多
Water overexploitation in the Lerma-Chapala Watershed, located in central Mexico, is linked to the development of a strong federal hydrocracy with the mission to capture as much water as possible in order to satisfy s...Water overexploitation in the Lerma-Chapala Watershed, located in central Mexico, is linked to the development of a strong federal hydrocracy with the mission to capture as much water as possible in order to satisfy social and political demands through the construction of dams and irrigation systems. The reduction in freshwater quantity and the deterioration of water quality are the outcome of industrial inflows, agriculture and urban untreated wastewater. This study has been leaded to determine hydrological, water quality, seed bioassays and the lake fisheries' decreases throughout its historical tendencies (1980-2004) in relation to changes in water levels. Hydrological data and water samples for chemical analysis, inorganic nutrients and seed bioassay, were taken from 10 sites alongside the river and two sites from Lake Chapala in years 2005 and 2009, the WQINsF (National Sanitation Foundation Water Quality Index) was estimated. The dissolved oxygen along the river was from anoxic (0.4) to 7 mg/L and the lake had 6.75 mg/L to 7.36 mg/L; the river had highest nutrients variations, Ntot and Ptot 1 mg/L to 〉 10 mg/L. The lake had few physicochemical variations and the lowest nutrient concentrations; WQINsF (water quality index) in the river-lake system showed very bad-bad quality and contamination in river, bad quality-light contamination in lake. Seed bioassays showed inhibition of root elongation and declining fisheries when low water levels were presented. Chapala Lake had better physicochemical and limnological conditions because of the wind action and water column mixing; in contrast the river, high hidrological variations caused by water administration in middle basin.展开更多
Patient safety has become a priority for the health system, including dentistry. Several studies showed that health care meant to improve people's health is an important source of disease. Good clinical practices aim...Patient safety has become a priority for the health system, including dentistry. Several studies showed that health care meant to improve people's health is an important source of disease. Good clinical practices aim to maximize effectiveness and therapeutic compliance, minimize risks and costs, respecting the patient's choice from generic drugs, also from the moment of prescribing, the supervision of drug-related events must be taken into account, not only on the patient but also in the environment. Pharmacovigilance and pharmacoecovigilance have to be conceived as a clinical practice in dentistry. There is no established culture of drug induced reaction reports by dentists in Uruguay, and awareness of environmental care is incipient. The pharmacy of faculty of dentistry, (Universidad de la Repfiblica), an institutional project that has been developed since 2006, is in a transformation process. The pharmacovigilance dentistry Node is in full development. The toxicovigilance and pharmacoecovigilance activities are recent. The general aim of this project was to establish the pbarmacovigilance, toxicovigilance and pharmacoecovigilance clinical practice in dentistry. The widespread use of cosmetic as toothpastes, or mouth rinses, drugs and dental materials, as well as exposure to chemical contaminants through the population's living habits and the environmental damage caused by drug wastes requires comprehensive and up-to-date information to establish rational strategies.展开更多
In the years 2008-2010, a study on the quality of tubers grown in the two crop production systems, i.e., organic and integrated in two locations: Jadwisin--Central and Osiny--South-Eastern of Poland were conducted. T...In the years 2008-2010, a study on the quality of tubers grown in the two crop production systems, i.e., organic and integrated in two locations: Jadwisin--Central and Osiny--South-Eastern of Poland were conducted. The influence of such factors as the crop production system (organic and integrated), the place of production (soil quality), variety and years of research on the chemical composition, i.e., tuber dry matter, starch, vitamin C, nitrates and glycoalkaloids were tested. It has been found that the greatest impact on the chemical composition of tubers had the climatic conditions during the growing season and genotype. They affected the contents of all tested components. The place of production affected the contents of dry matter, starch, vitamin C and nitrates. This factor had no effect on the content of glycoalkaloids. The least effect on the chemical tubers composition was in crop production system. It only affected the contents of dry matter, starch and vitamin C. There was no significant effect of this factor on the nitrate and glycoalkaloids content.展开更多
基金Project (51071135) supported by the National Natural Science Foundation of ChinaProject (20114301110005) supported by the Ph. D.Programs Foundation of Ministry of Education of ChinaProject (10XZX15) supported by the Science Foundation of Xiangtan University,China
文摘The effect of Si on the growth kinetics of intermetallic compounds during the reaction of solid iron and molten aluminum was investigated with a scanning electron microscope coupled with an energy dispersive X-ray spectroscope, and hot-dip aluminized experiments. The results show that the intermetallic layer is composed of major Fe2Al5 and minor FeAl3. The Al-Fe-Si ternary phase, rl/rg, is formed in the Fe2Al5 layer. The tongue-like morphology of the Fe2Als layer becomes less distinct and disappears finally as the content of Si in aluminum bath increases. Si in the bath improves the prohibiting ability to the growth of Fe2Als and FeAl3. When the contents of Si are 0, 0.5%, 1.0%, 1.5%, 2.0% and 3.0%, the activation energies of Fe2Al5 are evaluated to be 207, 186, 169, 168, 167 and 172 kJ/mol, respectively. The reduction of the activation energy might result from the lattice distortion caused by Si atom penetrating into the Fe2Al5 phase. When Si atom occupies the vacancy site, it blocks easy diffusion path and results in the disappearance of tongue-like morphology.
基金This study was supported by National High-Tech R﹠D Programmer of China (No.2003AA249070)
文摘In comparison with integrated pest management and chemical control, the authors put forward a new strategy of forest pest control, named ecological control of forest pest (ECFP). This paper reviewed the development history, summarized the concept and principles of ECFP, discussed the technology and methods of ECFP, and evaluated the ECFP and its application conditions.
文摘Biology is a rich source of great ideas that can inspire us to find successful ways to solve the challenging problems in engineering practices including those in the chemical industry. Bio-inspired chemical engineering(Bio Ch E)may be recognized as a significant branch of chemical engineering. It may consist of, but not limited to, the following three aspects: 1) Chemical engineering principles and unit operations in biological systems; 2) Process engineering principles for producing existing or developing new chemical products through living ‘devices';and 3) Chemical engineering processes and equipment that are designed and constructed through mimicking(does not have to reproduce one hundred percent) the biological systems including their physical–chemical and mechanical structures to deliver uniquely beneficial performances. This may also include the bio-inspired sensors for process monitoring. In this paper, the above aspects are defined and discussed which establishes the scope of BioChE.
基金funded by Chinese Academy of Sciences (Grant Nos. KZCX2-YW-BR-21 and KZZD-EW-TZ-06)Natural Science Foundation of China (Grant No. 41272200)
文摘Phosphorus(P),as a limiting nutrient,plays a crucial role in the mountainous ecosystem development.Its biogeochemical cycle in mountainous ecosystems determines the bioavailability and sustainable supply of P,and thus becomes a crucial process which needs to be fully understood and described for ecological and environmental conservation.However,most of research about P biogeochemical processes has been carried out in aquatic environment and agronomic field,but rare researches have been done in mountain ecosystem.In the present review,we summarize researches on P biogeochemical cycle concerning mountain ecosystem in recent decades,including rock weathering,the release,transformation and bioavailability of P,interactions between the P biological cycle and microbial and plant life,as well as the development of models.Based on the state of art,we propose the future work on this direction,including the integration of all these research,the development of a practical model to understand the P biogeochemical cycle and its bioavailability,and to provide a reference for ecological and environmental conservation of mountainous ecosystems and lowland aquatic systems.
基金The National Major Science and Technology Project(No.2017ZX07202004-005)the Natural Science Foundation of Jiangsu Province(No.BK20171351)+2 种基金the Japan Society for the Promotion of Science(No.P 19056)the National Natural Science Foundation of China(No.51828801)the Fundamental Research Funds for the Central Universities(No.2242016K41042)。
文摘In order to investigate the effect of the surface morphology and resistance of the TiO2 semiconductor on current output,TiO2 nanotube array bio-anodes(TNA)are synthesized at different electrolyte temperatures,thereby changing the length and surface roughness of the nanotubes.When the anodizing temperature is increased from 30 to 75℃,the length of the nanotubes increases from 1.459 to 4.183μm,which hinders the transfer of extracellular electrons to the electrodes.On the other hand,the surface roughness of TNA is significantly improved at higher temperatures,which is conducive to electron transfer.Therefore,samples processed at 45℃have the best current output performance.Compared with the treatment at 30℃under anodization,samples processed at 45℃can balance the resistance and roughness and have a higher electron transfer rate;the current output density of which is increased by 1.5 times,and the decolorization rate is increased by 0.8 times.Therefore,proper TNA surface morphology can improve the current output and the potential of wastewater treatment.
基金Supported by the National Natural Science Foundation of China(No.31502163)the General Project of Liaoning Provincial Education Department(No.L201604)the Modern Agro-industry Technology Research System(No.CARS-49)
文摘Ocean acidification leads to changes in physiological and immune responses of bivalves, but the eff ect on the immune enzyme activities of the Manila clam, R uditapes philippinarum, when the pH is lower than the normal value has not been studied in detail. In this study, experiments were conducted to determine how pH(7.4, 7.7, 8.0) affects the immune enzyme activities in the gill and hemocytes of the Manila clam. Membrane stability and phagocytosis increased with decrease of pH from 8.0 to 7.7 and then decreased at pH 7.4. The total protein content in the hemocytes and gills decreased with decreasing pH. Lysozyme content in the hemocytes increased with decreasing pH, and the diff erences were significant among the different pH groups(P < 0.05). Adenosine triphosphatase activity at pH 7.4 was significantly higher than in the other two groups, but no significant diff erence was observed between pH 7.7 and 8.0. Catalase activity decreased from pH 8.0 to 7.7 and then increased at pH 7.4, and the dif ferences were significant among the experimental groups( P < 0.05). These findings provide valuable information about the immune response of R. philippinarum to reduced water pH and insights for future research investigating exposure of bivalves to elevated CO_2 conditions.
文摘Despite the fact that miombo woodland soils have significant implications in global climate change processes, few studies have been done to characterize and classify the soils of the miombo woodland ecosystem of Tanzania. The current study was carried out to map and classify soils of Kitonga Forest Reserve, which is a typical miombo woodland ecosystem, in order to generate relevant information for their use and management. A representative study area of 52 km2 was selected and mapped at a scale of 1:50,000 on the basis of relief. Ten representative soil profiles were excavated and described using standard methods. Soil samples were taken from genetic soil horizons and analyzed in the laboratory for physico-chemical characteristics using standard methods. Using field and laboratory analytical data, the soils were classified according to the FAO-World Reference Base (FAO-WRB) for Soil Resources system as Cambisols, Leptosols and Fluvisols. In the USDA-NRCS Soil Taxonomy system the soils were classified as Inceptisols and Entisols. Topographical features played an important role in soil formation. The different soil types differed in physico-chemical properties, hence exhibit differences in their potentials, constraints and need specific management strategies. Texture varied from sandy to different loams; pH from 5.1 to 5.9; organic carbon from 0.9 g/kg to 20 g/kg; and CEC from 3 cmol/(+)kg to 24 cmol/(+)kg. Sustainable management of miombo woodlands ecosystem soils requires reduced deforestation and reduced land degradation.
基金Supported by the National Natural Science Foundation of China(Nos.31660138,31400405)the Jiangxi Water Science and Technology Fund(Nos.TG201501,KT201602)the Science and Technology Project from Ministry of Water Resources,China(Nos.ZXKT201508,SKY201503)
文摘Microcystins(MCs) are cyclic hepatotoxic peptides produced by the bloom-forming cyanobacterium Microcystis and present a public health hazard to humans and livestock. The removal of MCs from contaminated water with powdered activated carbon(PAC) has been employed as a simple and economic treatment strategy. In this study, PAC-Fe(Ⅲ) was prepared and utilized for the fast and efficient removal of MCs from water. PAC-Fe(Ⅲ) exhibited superior microcystin-LR(MC-LR) removal capacity and efficiency compared to the unmodified PAC. The MC-LR removal efficiency of PAC-Fe(Ⅲ) increased with decreasing p H within the pH range of 4.3 to 9.6. PAC-Fe(Ⅲ) could be reused for 3 times by methanol elution while the MC-LR removal efficiency was still over 70 percent. The removal efficiency was positively correlated to the ionic strength of water and negatively correlated to alkalinity. Natural organic matter(NOM) such as humic acid(HA) and salicylic acid(SA) generated low interference with MC-LR adsorption by PAC-Fe(Ⅲ). The complexation reaction between Fe^(3+) in PAC-Fe(Ⅲ) and the functional groups of MCLR was suggested as the key mechanism of MC-LR removal by PAC-Fe(Ⅲ). The results suggest that Femodified PAC is a promising material for the treatment of MC-contaminated waters.
文摘The community of Figuig is located in a desert area, east of Morocco. It is characterized by an arid climate. Part of the aquifers of the area has a high salinity which creates even worst conditions for the use of the scarce water available in the area. Therefore, it is essential to develop new water resources, especially for agriculture. For this reason, reclaiming wastewater for agricultural use is an essential strategy to increase water resources. The studied system is a wastewater treatment plant (WWTP) with stabilisation ponds; it treats a part of the wastewater of Figuig. The monitoring of the WWTP will allow to the physico-chemical and biological characterization of the treated water, and then, to verify two principal points: (1) the physico-chemical and pathogen parasites elimination; (2) the possibility of the treated water reuse in agricultural irrigation. The reductions recorded at the WWTP show a relatively preferment operation with an average decrease of 3.17 Ulog for faecal coliforms and 50-60% for organic matter. It was observed that the taxonomic density is slow in the WWTP; observed species are generally Cyanobacteria, Euglénophycea and Chlorophycea characteristic of eutrophic water sources.
基金Supported by the National Natural Science Foundation of China(Nos.40730107,41106162)the Chinese Polar Environment Comprehensive Investigation and Assessment Programs(Nos.CHINARE 2014-04-01,CHINARE 2014-02-01,CHINARE 2014-04-04)the Doctoral Fund of Ministry of Education of China(No.20103402110023)
文摘In Antarctica, the marine ecosystem is dynamically interrelated with the terrestrial ecosystem. An example of the link between these two ecosystems is the biogeochemical cycle of phosphorus. Bio- vectors, such as penguins, transport phosphorus from sea to land, play a key role in this cycle. In this paper, we selected three colonies of penguins, the most important seabirds in Antarctica, and computed the annual quantity of phosphorus transferred from sea to land by these birds. Our results show that adult penguins from colonies at Ardley Island, the Vestfold Hills, and Ross Island could transfer phosphorus in the form of guano at up to 12 349, 167 036, and 97 841 kg/a, respectively, over their breeding period. These quantities are equivalent to an annual input of 3.96× 10^9-1.63 × 10^10 kg of seawater to the land of Antarctica. Finally, we discuss the impact of phosphorus on the ice-flee areas of the Antarctica.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20433050 and No.20673106).
文摘The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only yields a steady state. Also,. the performance of such oscillations shows two maxima with the variation of the system size, indicating the occurrence of system size resonance. This behavior is found to be intimately connected with the canard phenomenon. Interestingly, it is also found that one of the optimal system sizes matches well with the real cell size, and such a match is robust to the variation of the control parameters.
基金Projects(2009GG10005004, 2010GHY10504) supported by the Scientific and Technological Foundation of Shandong Province,ChinaProject(2011GHY11531) supported by the Science and Technology Development Program of Shandong Province,ChinaProject(ZR2009BM015) supported by the Natural Science Foundation of Shandong Province,China
文摘A coupled system consisting of an upflow membrane-less microbial fuel cell (upflow ML-MFC) and a photobioreactor was developed, and its effectiveness for continuous wastewater treatment and electricity production was evaluated. Wastewater was fed to the upflow ML-MFC to remove chemical oxygen demand (COD), phosphorus and nitrogen with simultaneous electricity generation. The effluent from the cathode compartment of the upflow ML-MFC was then continuously fed to an external photobioreactor for removing the remaining phosphorus and nitrogen using microalgae. Alone, the upflow ML-MFC produces a maximum power density of 481 mW/m 3 , and obtains 77.9% COD, 23.5% total phosphorus (TP) and 97.6% NH4+-N removals. When combined with the photobioreactor, the system achieves 99.3% TP and 99.0% NH4+-N total removal. These results show both the effectiveness and the potential application of the coupled system to continuously treat domestic wastewater and simultaneously generate electricity and biomass.
文摘118 clinical strains of Shigella were serotyped, in which 116 strains were tested to be S. flexneri. The susceptibilities of the S .flexneri strains to quinolones were measured by the disk-diffusion method. It was found that most S .flexneri strains were susceptible to norfloxacin and ciprofloxacin, but resistant to nalidixic acid. To study the correlation between gyrA mutations and quinolones resistance, a fragment within the gyrA gene was amplified by PCR. The SSCP (Single-Strand Conformation Polymorphism) analysis was applied to detect mutations in PCR products of different strains. The mutations were then confirmed by DNA sequencing. Altogether, two types of mutation were revealed, in which one type was single mutation ( C42-T), and the other was double mutations ( C42-T and A54- G). By statistical analysis, C42-T (encoding Ser83-keu substitution) was shown to have correlation with nalidixic-acid resistance in the clinical strains of Shigella, while A54-G (encoding Asp87-Gly substitution) was shown to have correlations with both norfloxacin resistance and ciprofloxacin resistance.
基金supported by the National Science Foundation project of M. Li (OCE-082543)
文摘Recent observations support an emerging paradigm that climate variability dominates nutrient enrichment in costal eco-systems, which can explain seasonal and inter-annual variability of phytoplankton community composition, biomass (Chl-a), and primary production (PP). In this paper, we combined observation and modeling to investigate the regulation of phytoplankton dynamics in Chesapeake Bay. The year we chose is 1996 that has high river runoff and is usually called a 'wet year'. A 3-D physical-biogeochemical model based on ROMS was developed to simulate the seasonal cycle and the regional distributions of phytoplankton biomass and primary production in Chesapeake Bay. Based on the model results, NO3 presents a strong contrast to the river nitrate load during spring and the highest concentration in the bay reaches around 80 mmol Nm-3 . Compared with the normal year, phytoplankton bloom in spring of 1996 appears in lower latitudes with a higher concentration. Quantitative comparison between the modeled and observed seasonal averaged dissolved inorganic nitrogen concentrations shows that the model produces reliable results. The correlation coefficient r2 for all quantities exceeds 0.95, and the skill parameter for the four seasons is all above 0.95.
文摘The implementation of multiple enzymes for chemical production in a cell‐free scenario is an emerging field in biomanufacturing.It enables the redesign and reconstitution of new enzymatic routes for producing chemicals that may be hard to obtain from natural pathways.Although the construction of a cell‐free multienzyme system is highly flexible and adaptable,it is challenging to make all enzymatic reactions act in concert.Recently,modular construction has been conceptual‐ized as an effective way to harmonize diverse enzymatic reactions.In this review,we introduce the concept of a multienzyme module and exemplify representative modules found in Nature.We then categorize recent developments of synthetic multienzyme modules into main‐reaction modules and auxiliary modules according to their roles in reaction routes.We highlight four main‐reaction mod‐ules that can perform carbon metabolism,carbon assimilation,protein glycosylation and nonribo‐somal peptide synthesis,and exemplify auxiliary modules used for energy supply,protection and reinforcement for main reactions.The reactor‐level modularization of multienzyme catalysis is also discussed.
文摘This project describes an integral solution to implement a module-based platform for the control of all the automated systems inside a house and a remote control of the entrance access to this house. A biometrical access based on the hand veins has been used with a complete local and remote access control system. A technologically ergonomic way to control the house, as well as some biological signal monitoring has also been developed. This has been done by knowing the physical restrictions of the collective who will live in the house. A set of different sensors will control this operation. In order to control all the home automated systems coordinate the whole platform using the TV remote. This project will implement the OSGI standard. This implementation should ensure the system scalability in terms of including new hardware. In addition, a ZibBee networking system has been developed to enable communication between all the sensors, systems and the central processor.
文摘Water overexploitation in the Lerma-Chapala Watershed, located in central Mexico, is linked to the development of a strong federal hydrocracy with the mission to capture as much water as possible in order to satisfy social and political demands through the construction of dams and irrigation systems. The reduction in freshwater quantity and the deterioration of water quality are the outcome of industrial inflows, agriculture and urban untreated wastewater. This study has been leaded to determine hydrological, water quality, seed bioassays and the lake fisheries' decreases throughout its historical tendencies (1980-2004) in relation to changes in water levels. Hydrological data and water samples for chemical analysis, inorganic nutrients and seed bioassay, were taken from 10 sites alongside the river and two sites from Lake Chapala in years 2005 and 2009, the WQINsF (National Sanitation Foundation Water Quality Index) was estimated. The dissolved oxygen along the river was from anoxic (0.4) to 7 mg/L and the lake had 6.75 mg/L to 7.36 mg/L; the river had highest nutrients variations, Ntot and Ptot 1 mg/L to 〉 10 mg/L. The lake had few physicochemical variations and the lowest nutrient concentrations; WQINsF (water quality index) in the river-lake system showed very bad-bad quality and contamination in river, bad quality-light contamination in lake. Seed bioassays showed inhibition of root elongation and declining fisheries when low water levels were presented. Chapala Lake had better physicochemical and limnological conditions because of the wind action and water column mixing; in contrast the river, high hidrological variations caused by water administration in middle basin.
文摘Patient safety has become a priority for the health system, including dentistry. Several studies showed that health care meant to improve people's health is an important source of disease. Good clinical practices aim to maximize effectiveness and therapeutic compliance, minimize risks and costs, respecting the patient's choice from generic drugs, also from the moment of prescribing, the supervision of drug-related events must be taken into account, not only on the patient but also in the environment. Pharmacovigilance and pharmacoecovigilance have to be conceived as a clinical practice in dentistry. There is no established culture of drug induced reaction reports by dentists in Uruguay, and awareness of environmental care is incipient. The pharmacy of faculty of dentistry, (Universidad de la Repfiblica), an institutional project that has been developed since 2006, is in a transformation process. The pharmacovigilance dentistry Node is in full development. The toxicovigilance and pharmacoecovigilance activities are recent. The general aim of this project was to establish the pbarmacovigilance, toxicovigilance and pharmacoecovigilance clinical practice in dentistry. The widespread use of cosmetic as toothpastes, or mouth rinses, drugs and dental materials, as well as exposure to chemical contaminants through the population's living habits and the environmental damage caused by drug wastes requires comprehensive and up-to-date information to establish rational strategies.
文摘In the years 2008-2010, a study on the quality of tubers grown in the two crop production systems, i.e., organic and integrated in two locations: Jadwisin--Central and Osiny--South-Eastern of Poland were conducted. The influence of such factors as the crop production system (organic and integrated), the place of production (soil quality), variety and years of research on the chemical composition, i.e., tuber dry matter, starch, vitamin C, nitrates and glycoalkaloids were tested. It has been found that the greatest impact on the chemical composition of tubers had the climatic conditions during the growing season and genotype. They affected the contents of all tested components. The place of production affected the contents of dry matter, starch, vitamin C and nitrates. This factor had no effect on the content of glycoalkaloids. The least effect on the chemical tubers composition was in crop production system. It only affected the contents of dry matter, starch and vitamin C. There was no significant effect of this factor on the nitrate and glycoalkaloids content.