大玉竹低聚糖硫酸酯抗HSV-2病毒活性的研究

从传统中药大玉竹中提取低聚糖Ｐｏｏｓ,用吡啶－氯磺酸法制备了它的硫酸酯衍生物Ｓ－Ｐｏｏｓ,产物经红外鉴定,证实Ｐｏｏｓ硫酸酯化后羟基连上硫酸基,硫含量为８．４７％,取代度（Ｄｓ）为０．６体外实验研究了Ｐｏｏｓ、Ｓ－Ｐｏｏｓ对非洲绿猴肾细胞（Ｖｅｒｏ）的细胞毒怀和抗单纯疱疹病毒２型（ＨＳＶ－２）活性。结果表明,Ｐｏｏｓ和Ｓ－Ｐｏｏｓ都无细胞毒性。Ｐｏｏｓ本身无抗病毒活性,对ＨＳＶ－２引起的细胞病变和     

Influence of the zebra mussel and fish fry on structural and functional characteristics of microorganisms in experimental ecosystems

The interactions of zebra mussels, invertebrates, fish, and microorganisms were studied experimentally. Trends in the distribution of total bacterial biomass, the abundance of heterotrophic organisms, and their functional activities in water and grounds were analyzed. The most favorable conditions for development of bacteria developed in June, in the presence of fish and without zebra mussels. In experimental ecosystems with zebra mussels, a decrease in the abundance and activity of microorganisms and a change of dominant yeast forms were observed.     

Effects of ecological factors on the diurnal activity rhythm of Yakutian black-capped marmots (Marmota camtschatica bungei) in the arctic

It is established that the activity of marmots (the genusMarmota) on the surface is timed to the daylight period. In the Arctic, under conditions of continuous illumination (the polar day), the diurnal rhythm of black-capped marmotsMarmota camtschatica bungei on the surface has a “daylight” pattern. The main external regulator of the diurnal rhythm is the altitude of the sun above the horizon. In the cold period, however, the effect of air temperature on animal activity becomes stronger.     

水稻专用叶面喷剂对水稻幼苗生长的影响

用水稻专用叶面喷剂喷施水稻秧苗,1670~2500mg/L浓度处理可改善秧苗素质,控制株高,秧苗粗壮,假茎宽,干物质增多,促进分蘖．5000mg/L浓度处理抑制秧苗生长．水稻专用叶面喷剂可提高秧苗叶片可溶性糖、可溶性蛋白质、叶绿素含量和硝酸还原酶活性．     

Disinfection By-Products in Water Produced by Ozonation and Chlorination

Water produced by advanced treatment of a groundwater was evaluated to determine the amount of DBPs (Disinfection By-Products) including trihalomethanes (THMs). Both Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GS/MS) were adopted for detection and identification of DBPs such as trihalomethanes (THMs), halo-acetic acids (HAAs) and aldehydes. Two disinfection modes (ozonation followed by chlorination and chlorination alone) were compared to determine the DBPs generation. The mutagenitic acivity of ozonated water, chlorinated water after ozonation and potable water was assessed using the Ames test. Chloroform, dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were the main constituents of THMs and HAAs, respectively. THMs accounted for more than 85% of all DBPs measured, whereas haloacetic acids accounted for around 14%. Ozonation followed by chlorination proved to be better in terms of THMs and HAAs control. The combined system produced 28.3% less DBPs compared to chlorination alone. Ozonation was found capable of reducing mutagenic matter in the groundwater by 54.7%. The combined system also resulted in water with no mutagenicity.     

长期不同施肥处理对红壤水稻土酶活性及微生物群落功能多样性的影响

江西红壤生态试验站长期定位试验中不同施肥处理红壤水稻土酶活性及微生物群落功能多样性的研究结果表明,不同施肥条件下土壤酶活性及微生物群落功能多样性差异较大,土壤脲酶和脱氢酶活性可以作为土壤肥力的指标。经过20 a施肥管理及水稻种植,土壤酶活性及生物量有很大提高;但是B IOLOGTM生态测试板测定结果显示,施肥使微生物生物群落物种丰富度有所减少,施P土壤酶活性、微生物群落功能多样性均大于未施P土壤,采用秸秆还田处理的群落物种均一性高于未采用秸秆还田处理。     

Effects of synthetic pyrethroids and methidation on activities of some digestive enzymes in carp (Cyprinus carpio L.)

Abstract

The effects of pyrethroid pesticides (deltamethrin, permethrin and cypermethrin) and an organophosphate ester (methidation) on the activities of carp trypsin, α‐chymotrypsin, carboxypeptidase A and lipase were studied. The enzymes were isolated from the gastrointestinal tract and the effects of the pesticides were investigated during incubation for 5 min. The activity of trypsin was influenced only slightly by the presence of deltamethrin and methidation, whereas permethrin and cypermethrin caused significant inhibition. The pyrethroid pesticides at lower concentrations resulted in a slight activation of α‐chymotrypsin. Methidation inhibited the α‐chymotrypsin activity by about 20%. These pesticides modified the lipase activity to a lesser extent; the highest inhibition was measured with cypermethrin. The carboxypeptidase A activity was inhibited by both pyrethroid pesticides and methidation. The results suggest that these pesticides might interact with the active conformation of the studied hydrolytic enzymes, resulting in changes in their activities.     

20世纪长江的3次巨洪

分析了形成20世纪长江3次巨洪的3个遥相关因子：（1）太阳黑子活动;（2）厄尔尼诺事件,（3）青藏高原南部大震。依据长江巨洪和遥相关因子的基本事实,讨论了长江发生巨洪的统计规律。指出当3个因子的出现时间互相重叠时,长江很可能发生巨洪,这对长江巨洪的超长期预测具有重要的指导作用。     

Green and efficient degradation of cefoperazone sodium by Bi4O5Br2 leading to the production of non-toxic products: Performance and degradation pathway

Photocatalytic process represents a promising approach to overcome the pollution challenge associated with the antibiotics-containing wastewater. This study provides a green, efficient and novel approach to remove cephalosporins, particularly cefoperazone sodium (CFP). Bi₄O₅Br₂ was chosen for the first time to systematically study its degradation for CFP, including the analysis of material structure, degradation performance, the structure and toxicity of the transformation products, etc. The degradation rate results indicated that Bi₄O₅Br₂ had an excellent catalytic activity leading to 78% CFP removal compared with the pure BiOBr (38%) within 120 min of visible light irradiation. In addition, the Bi₄O₅Br₂ presents high stability and good organic carbon removal efficiency. The effects of the solution pH (3.12 - 8.75) on catalytic activity revealed that CFP was mainly photocatalyzed under acidic conditions and hydrolyzed under alkaline conditions. Combined with active species and degradation product identification, the photocatalytic degradation pathways of CFP by Bi₄O₅Br₂ was proposed, including hydrolysis, oxidation, reduction and decarboxylation. Most importantly, the identified products were all hydrolysis rather than oxidation byproducts transformed from the intermediate of β-lactam bond cleavage in CFP molecule, quite different from the mostly previous studies. Furthermore, the final products were demonstrated to be less toxic through the toxicity analysis. Overall, this study illustrates the detailed mechanism of CFP degradation by Bi₄O₅Br₂ and confirms Bi₄O₅Br₂ to be a promising material for the photodegradation of CFP.     

黄河三角洲不同植被类型土壤酶活性的季节变化

黄河三角洲自然保护区的酶活性季节特征一定程度影响了该地植被分布类型,为研究黄河三角洲自然保护区不同植被土壤酶活性的季节特征,分别选取碱蓬（Suaeda salsa）、柽柳（Tamarix chinensis）、芦苇（Phragmites communis）、刺槐（Black Locust）和高粱（Sorghum）5种典型植被作为研究对象,分别在4个季节采集不同深度土壤,测定土壤脲酶、过氧化氢酶、碱性磷酸酶、脱氢酶、蔗糖酶活性。结果表明,土壤脱氢酶活性规律表现为碱蓬>柽柳>刺槐>高粱>芦苇,其他酶活性总体变化规律表现为刺槐>柽柳>高粱>芦苇>碱蓬;在同一季节中,不同植被间酶活性存在显著性差异,柽柳和刺槐林土壤脲酶、碱性磷酸酶和蔗糖酶活性普遍高于其他群落,碱蓬最低;土壤酶活性与土壤基础理化指标有着密切关系,土壤过氧化氢酶活性、脲酶活性和蔗糖酶活性之间存在极显著性正相关（P<0.01）,过氧化氢酶,脲酶和蔗糖酶与有机质、碱解氮呈显著性正相关（P<0.01）,脱氢酶与速效磷呈显著性正相关与pH之间呈负相关（P<0.01）;在0—...