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Phosphorus limitation on bacterial regrowth in drinking water

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Journal of Environmental Sciences 2003年第6期15卷 773-778页

作者： SANGJun-qiang ZHANGXi-hui YUGuo-zhong wangzhan-sheng ResearchCenterforEnvironmentalEngineeringandManagement ShenzhenGraduateSchoolTsinghuaUniversityShenzhen518057China. DepartmentofEnvironmentalScienceandEngineering TsinghuaUniversityBeijing100084China

Assimilable organic carbon(AOC) test and bacterial regrowth potential(BRP) analysis were used to investigate the effect of phosphorus on bacterial regrowth in the drinking water that was made from some raw water taken from a reservoir located in northern China. It was shown that AOC of the drinking water samples increased by 43.9%—59.6% and BRP increased by 100%—235% when 50 μg/L PO 3- 4-P(as NaH 2PO 4) was added alone to the drinking water samples. This result was clear evidence of phosphorus limitation on bacteria regrowth in the drinking water. This investigation indicated the importance of phosphorus in ensuring biological stability of drinking water and offered a novel possible option to restrict microbial regrowth in drinking water distribution system by applying appropriate technologies to remove phosphorus efficiently from drinking water in China.

关键词： drinking water bacterial regrowth phosphorus AOC biological stability

Modification on the conventional procedure to measure AOC in drinking water

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Journal of Environmental Sciences 2004年第6期16卷 996-1000页

作者： LIFu-zhi SANGJun-qiang ZHANGXi-hui wangzhan-sheng ResearchCenterforEnvironmentalEngineering＆Management ShenzhenGraduateSchoolTsinghuaUniversityShenzhen518055China DepartmentofEnvironmentalScienceandEngineering TsinghuaUniversityBeijing100084China

Additional phosphorus will be introduced to water sample if the conventional procedure is used to measure assimilable organic carbon(AOC) in drinking water. It has been shown that there are the cases that phosphorus is the limiting nutrient for microbial growth in drinking water. The measured value of AOC would not be able to indicate appropriately the regrowth potential of bacteria in this case. The conventional procedure used to measure AOC was modified to avoid the introduction of additional phosphorus to water sample in this study. It was shown that it was feasible to measure AOC in water using the modified procedure. Furthermore, the measured value of AOC determined by the modified procedure could indicate appropriately the regrowth potential of bacteria in drinking water despite either organics or phosphorus was the limiting nutrient for bacterial regrowth.

关键词： drinking water assimilable organic carbon bacterial regrowth phosphorus organics

Phosphorus limitation in biofiltration for drinking water treatment

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Journal of Environmental Sciences 2003年第4期15卷 494-499页

作者： YUXin ZHANGXiao-jian LIUXiao-ling ZHAOXiao-dong wangzhan-sheng DepartmentofEnvironmentalScienceandEngineering TsinghuaUniversityBeijing100084China. XuzhouWaterSupplyCompany Xuzhou221004China

Bacterial growth potential(BGP) method and two parallel pilot scale biofilters were used to investigate phosphorus limitation and its effect on the removal of organic matters in biofiltration for drinking water treatment. Addition of phosphorus can substantially increase the BGPs of the samples. Its effect was equivalent to that of addition of a mixture of various inorganic nutrients including phosphorus. The biofilter with phosphate added into its influent performed a higher biological stability of the effluent and a higher COD Mn removal than the control filter. These results suggested that phosphorus was the limiting nutrient in the biofiltration and the removal efficiency of organic matters could be improved by adding phosphate into the influent.

关键词： drinking water biological treatment biofilter limiting nutrient phosphorus carbon

Biological pretreatment of Yellow River water

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Journal of Environmental Sciences 2005年第4期17卷 557-561页

作者： XIEShu-guang TANGXiao-yan WUWei-zhong WENDong-hui wangzhan-sheng DepartmentofEnvironmentalSciences CollegeofEnvironmentalSciencesPekingUniversityBeijing100871China DepartmentofEnvironmentalScienceandEngineering TsinghuaUniversityBeijing100084China

Bio-ceramic filter(BF) and moving-bed biofilm reactor(MBBR) were used for biological pretreatment of Yellow River water in this study. The BF only had slight advantage over MBBR for TOC and ammonia removal. However, like UV_ 254 , the average removal rate of THMFP in the BF was much higher than that in the MBBR. UV_ 254 removal did not show obvious correlation with trihalomethane formation potential(THMFP) removal. Hexachlorocyclohexane could be effectively removed in both BF and MBBR. As for diatom and cyanobateria removal the MBBR had better performance than the BF, which was contrary to the average chlorophyll-a(Chl-a) removal rate. The proposal was made in this study that biological flocculation and sedimentation of sloughed biofilm should play a more important role on algae removal in the MBBR than in the BF. The BF and MBBR could effectively remove microcystins. Moreover, MBBR could be a promising technology for biological pretreatment.

关键词： bio-ceramic filter(BF) moving-bed biofilm reactor(MBBR) Yellow River biological pretreatment

Epidemiology and current management of cerebrovascular disease in China

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Journal of Geriatric Cardiology 2024年第5期21卷 465-474页

作者： sheng-Shou HU The Writing Committee of the Report on Cardiovascular Health and Diseases in China

The Annual Report on Cardiovascular Health and Diseases in China(2022)intricate landscape of cardiovascular health in *** connection with the previous section,this fifth section of the report continues the dissection on the manage-ment of cardiovascular diseases(CVD).Cerebrovascular disease is the leading cause of death and loss of healthy life among Chinese *** on the results of GBD 2019,from 1990 to 2019,the years of life lost due to premature death caused by stroke showed a decreasing trend,while the years lived with disability still increased *** present,national mortal-ity surveillance system can provide national and provincial representative annual death data on cerebrovascular disease,but the national representative data on some other important epidemiological indicators(such as incidence,prevalence,disability rate,and case fatality rate)are scarce in *** the construction of large cohort population and extension of follow-up time,re-search on stroke-related risk factors is increasing,providing a basis for the prevention and control of risk *** to limited large-scale population-based intervention studies,there is a lack of epidemiological evidence to transform into feasible interven-tion strategies and *** recent years,great progress in endovascular treatment for basilar-artery occlusion has been achieved in China,but there is still much room for improvement of guideline-based anticoagulant treatment and lipid-lowering treatment,as well as standardized diagnosis and treatment among patients with ischemic stroke.

关键词： prevention diagnosis Epidemiology

Epidemiology and current management of cardiovascular disease in China

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Journal of Geriatric Cardiology 2024年第4期21卷 387-406页

作者： sheng-Shou HU the Writing Committee of the Report on Cardiovascular Health and Dis-eases in China Fuwai Hospital National Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

The Annual Report on Cardiovascular Health and Diseases in China(2022) intricate landscape of cardiovascular health in China. This is the fourth section of the report with a specific focus on epidemiology and current management of cardiovascular disease(CVD) in China. This section of the report highlights the epidemiological trends of CVD in China. It reveal a concerning rise in prevalence, with approximately 330 million affected individuals, including significant numbers with stroke, coronary artery disease(CAD), heart failure, and other conditions. CVD stands as the primary cause of mortality among both urban and rural populations, accounting for nearly half of all deaths in 2020. Mortality rates are notably higher in rural areas compared to urban centers since 2009. While age-standardized mortality rates have decreased, the absolute number of CVD deaths has increased, primarily due to population aging. Ischemic heart disease, hemorrhagic and ischemic strokes are the leading causes of CVD-related deaths. Notably, the burden of atherosclerotic cardiovascular disease has risen substantially, with atherosclerotic cardiovascular disease-related deaths increasing from 1990 to 2016. The incidence of ischemic stroke and ischemic heart disease has shown similar increasing trends over the past three decades. CAD mortality, particularly acute myocardial infarction, has been on the rise, with higher mortality rates observed in rural areas since 2016. The prevalence of CAD has increased significantly, with over 11 million patients identified in 2013. Studies assessing hospital performance in managing acute coronary syndrome reveal gaps in adherence to guideline-recommended strategies, with disparities in care quality across hospitals. However, initiatives like the China Patient-centered Evaluative Assessment of Cardiac Events(PEACE)-Retrospective AMI Study and the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome(CCC-ACS) project aim to improve patien

关键词： epidemiology landscape deaths

Stimuli-evoked NOergic molecules and neuropeptides at acupuncture points and the gracile nucleus contribute to signal transduction of propagated sensation along the meridian through the dorsal medulla-thalamic pathways

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Journal of Integrative Medicine 2024年第5期22卷 515-522页

作者： sheng-xing Ma Lundquist Institute for Biomedical Innovation Harbor-University of California at Los Angeles (UCLA) Medical Center Department of Obstetrics and Gynecology David Geffen School of Medicine at UCLA and Harbor-UCLA Medical Center

Numerous studies from different international groups have demonstrated that sensations can be propagated along acupuncture channel pathways. The propagated sensation along the channel pathway(PSCP)can be elicited by electroacupuncture(EA), transcutaneous electrical nerve stimulation(TENS), manual acupuncture(MA), and heat applied to distal acupuncture points(acupoints). Nitric oxide(NO) levels were reported to be elevated in the gracile nucleus and skin regions near to the EA sites, with higher levels at acupoints associated with an enhanced expression of NO synthase and transient receptor potential vanilloid type 1. The stimuli, EA, MA, TENS, and heat, have been used to elicit axonal reflexes, which increase local release of NO and neuropeptides such as calcitonin gene related peptide. Furthermore, the sensation of PSCP along the body surface occurs only ipsilaterally to the stimulated acupoints in various human studies, which does not support the involvement of the spinal-thalamic pathway, which would involve cross over transmission of the signals. The gracile nucleus receives ascending input from the sciatic nerve and responds to somatosensory stimulation mainly on the ipsilateral side via the dorsal column pathway. EA at Zusanli(ST36) increases NO release and expression of NO synthase mainly in the ipsilateral side of the gracile nucleus, while the cardiovascular effects and analgesic responses to EA at ST36 are changed by influences of L-arginine-derived NO synthesis in the ipsilateral gracile nucleus in rats. The stimuli-induced release of NOergic molecules and neuropeptides exist high levels in the acupoints, which contain rich neuronal components and blood vessels. Enhanced NOergic molecules at acupoints cause axon reflexes during the stimuli, which elevate cutaneous blood flow. Elevated NOergic molecules and local blood flow may spread over acupoints one after another along the meridian lines differing from nerve pathways following the stimuli to induce PSC

关键词： Axon reflex Biophysical approaches Calcitonin related polypeptide Dorsal funiculus tract Meridian system Nitric oxide

In silico optimization of actuation performance in dielectric elastomercomposites via integrated finite element modeling and deep learning

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 48-56页

作者： Jiaxuan Ma sheng Sun Materials Genome Institute Shanghai UniversityShanghai 200444China Zhejiang Laboratory Hangzhou 311100China Shanghai Frontier Science Center of Mechanoinformatics Shanghai UniversityShanghai 200444China

Dielectric elastomers(DEs)require balanced electric actuation performance and mechanical integrity under applied *** high dielectric particles as fillers provides extensive design space to optimize concentration,morphology,and distribution for improved actuation performance and material *** study presents an integrated framework combining finite element modeling(FEM)and deep learning to optimize the microstructure of DE *** first calculates actuation performance and the effective modulus across varied filler combinations,with these data used to train a convolutional neural network(CNN).Integrating the CNN into a multi-objective genetic algorithm generates designs with enhanced actuation performance and material modulus compared to the conventional optimization approach based on FEM approach within the same *** framework harnesses artificial intelligence to navigate vast design possibilities,enabling optimized microstructures for high-performance DE composites.

关键词： Dielectric elastomer composites Multi-objective optimization Finite element modeling Convolutional neural network

Centered Waves for the Two-dimensional Pseudo-Steady van der Waals Gas Satisfied Maxwell's Law Around a Sharp Corner

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Chinese Annals of Mathematics,Series B 2024年第04期45卷 537-554页

作者： Shuangrong LI Wancheng sheng Department of Mathematics Shanghai University Shanghai 200444 China Department of Mathematics Zhejiang University of Science and Technology Department of Mathematics Newtouch Center for Mathematics of Shanghai University Shanghai University

In this paper, the authors study the centered waves for the two-dimensional(2D for short) pseudo-steady supersonic flow with van der Waals gas satisfied Maxwell's law around a sharp corner. In view of the initial value of the specific volume and the properties of van der Waals gas, the centered waves at the sharp corner are constructed by classification. It is shown that the supersonic incoming flow turns the sharp corner by a centered simple wave or a centered simple wave with right-contact discontinuity or a composite wave(jump-fan, fan-jump or fan-jump-fan), or a combination of waves and constant state. Moreover, the critical angle of the sharp corner corresponding to the appearance of the vacuum phenomenon is obtained.

关键词： Centered simple wave Composite wave Two-dimensional Euler equations Van der Waals gas