幸福河湖水生生物评价指标分析及探讨

建设造福人民的幸福河湖是新时期河湖治理的目标,构建幸福河湖评价指标体系是检验河湖治理成效的重要手段,河湖水生物评价指标是幸福河湖评价指标体系的关键内容。以某省幸福河湖评价办法为例,笔者从幸福河湖评价体系总框架、水生物评价指标选取、涵义及测算方法等方面进行了探讨研究,分析了幸福河湖水生物评价指标的代表性、监测与评价标准的统一性、调查结果的准确性及评价结论的可靠性,以及水生物评价指标体系构建面临的问题。提出要统一标准体系、健全生物评价调查方法、加强生态监测队伍建设、提升政府公众生态保护意识的建议,以期为幸福河湖建设提供借鉴。

Evaluation of CA125 and NT-proBNP values in patients undergoing transcatheter aortic valve implantation

Background Transcatheter aortic valve implantation （TAVI） is a minimally invasive, emerging therapy in surgically high risk, or in- operable patients. Parameters used for risk classification have some deficiencies in the selection of patients. The objective of this study is to evaluate the impact of TAVI on carbohydrate antigen 125 （CA125） and N-terminal pro brain-type natriuretic peptide （NT-proBNP） as biomarkers that have been used frequently in recent years, and also the relationship of these biomarkers to prognosis. Methods ＆ Results Transcatheter aortic valve implantation was practiced on 31 patients in this study. Then, CA125 and NT-proBNP levels studied in patients prior to and after the TAVI were evaluated. The patients were also grouped in accordance with their left ventrieular ejection fraction （LVEF） and CA125 levels （LVEF 〉 40% and 〈 40%; CA125 ≤ 35 U/L and 〉 35 U/L）. The TAVI operation was successfully performed in all patients. There was no in-hospital mortality and substantial improvement in functional capacity was detected at follow ups. In addition, a statistically significant decrease was detected in post-TAVI CA 125 and NT-proBNP levels of all patients （CA 125 83.8 ± 18.1 U/L vs. 64.3 ±14.2 U/L, P = 0.008; NT-proBNP： 4633.6± 627.6 pg/mL vs. 2866.3±536.8 pg/mL, P 〈 0.001）. In groups divided according to the CA125 levels, there was also statistically significant post-TAVI decline in CA125 levels. Within CA125 〉 35 U/L and LVEF 〈 40% groups, the permanent need for a pacemaker was required in one （3.2%） patient and mortality was observed in two （6.4%） patients after TAVI at follow up. Conclusions The results show that TAVI can be performed effectively and reliably in patients with high baseline levels of CA125 and NT-proBNP. These biomarkers are reduced substantially with TAVI, while high biomarker levels are associated with undesired events, and certainly, these biomarkers can be used for risk classifications in patient selection for TAVI.

Synthesis and Characterization of a Hydroxyethyl Derivative of Chitosan and Evaluation of Its Biosafety

Hydroxyethyl chitosan （HE-chitosan） is a water-soluble derivative of chitosan with many apparent biological properties. For example, it is non-toxic and rapidly biodegradable. Moreover, HE-chitosan has advantages in water-solubility, moisture retention and gelling property due to its hydroxyethyl group. However, the biocompatibility and biodegradability of this multifimctional de- rivative have rarely been documented although they are critical for its application in biomedical and clinical treatments. The purpose of this work was to evaluate the biosafety of HE-chitosan, and draw important clues for its diverse applications. HE-chitosan was synthesized and characterized its chemical structure with FTIR. Its molecular weight （Mw） was determined by gel permeation chro- matography （GPC）, and its deacetylation degree （DD） was investigated through potentiometric analysis. The cytotoxicity of HE-chitosan on mouse fibroblast cell L929 was tested. The biocompatibility and biodegradability of HE-chitosan in rat and rabbit were evaluated. The FTIR results indicated that the hydroxyethyl groups were linked to C6 of chitosan. The GPC analysis confirmed that its Mw was about 90.01 kDa. It was also demonstrated that HE-chitosan had excellent biocompatibility and biodegradability in vivo and had no cytotoxicity on L929. These findings indicated that HE-chitosan can potentially be applied as a biomaterial in tissue engineering, drug delivery, and other biomedical fields.

Water and Sediment Quality Assessment of a Multipurpose Reservoir in India

Malampuzha reservoir is a multipurpose reservoir in south India. Seven water samples and four sediment samples were studied for the physico-chemical and bacteriological nature of the Malampuzha reservoir water and sediments. Bacteriological analysis indicated the microbial contamination of the reservoir and the physico-chemical characteristics indicated that the water is non potable directly. Analysis of irrigational water quality by SAR, Kelly＇s ratio and SSP indicates that the reservoir water is suitable for irrigation. Heavy metal pollution of the sediments was evaluated based on Sediment Quality Guidelines （SQG）, Pollution Load Index （PLI） and degree of contamination （Cd） of soil in four stations. Principal Component Analysis （PCA） was done to find out the possible linear combination of the original variables of trace metals. Results of PCA showed that no collinearity existed among the studied metals. However, emphasis on the monitoring of Cu and Ni should be preferred because of its alarmingly higher contamination value.

Application of biomonitoring and support vector machine in water quality assessment

The behavior of schools of zebrafish （Danio rerio） was studied in acute toxicity environments. Behavioral features were extracted and a method for water quality assessment using support vector machine （SVM） was de- veloped. The behavioral parameters of fish were recorded and analyzed during one hour in an environment of a 24-h half-lethal concentration （LC50） of a pollutant. The data were used to develop a method to evaluate water quality, so as 6＋ 2＋ to give an early indication of toxicity. Four kinds of metal ions （Cu2~, Hg2~, Cr , and Cd ） were used for toxicity testing. To enhance the efficiency and accuracy of assessment, a method combining SVM and a genetic algorithm （GA） was used. The results showed that the average prediction accuracy of the method was over 80% and the time cost was acceptable. The method gave satisfactory results for a variety of metal pollutants, demonstrating that this is an effective approach to the classification of water quality.