农药对土壤脲酶活性的影响

通过模拟方法,研究了豆磺隆和呋喃丹对草甸棕壤和黑土6个土样脲酶活性的影响.结果表明,在供试浓度范围内,两种农药对土壤脲酶均有不同程度的激活作用,其中豆磺隆对草甸棕壤和黑土脲酶活性的最大增幅分别为46.95％和39.36％,呋喃丹分别为21.08％和12.70％.豆磺隆和呋喃丹浓度与土壤脲酶活性之间用二元一次方程拟和效果较好,分别有5个和3个土样的方程达到了显著或极显著相关水平,且二次项系数为负,总体上表现为先增加后降低的规律性变化.从两种农药对土壤脲酶的增幅和方程系数来看,豆磺隆对土壤脲酶活性的影响比呋喃丹明显.     

豆磺隆对北方草甸棕壤土壤酶活性的影响

通过室内模拟方法,以北方具有代表性的草甸棕壤为研究对象,研究了除草剂豆磺隆对土壤脲酶、转化酶和三种磷酸酶活性的影响。结果显示,在试验浓度范围内,豆磺隆对土壤脲酶和转化酶总体上有激活作用,影响幅度分别为3.07%—20.02%和?1.73%—5.67%;除个别浓度外,豆磺隆对三种土壤磷酸酶均有抑制作用,豆磺隆浓度为5 mg?kg–1时对酸性磷酸酶的抑制作用最强,抑制率为17.92%,对中性磷酸酶的抑制率仅在0.77%—1.54%之间,对碱性磷酸酶的抑制率为8.95%—20.60%。豆磺隆对脲酶、转化酶、酸性磷酸酶和中性磷酸酶活性的影响较小,且未表现出明显规律性,仅与碱性磷酸酶呈显著(p0.05)的对数负相关关系,表明碱性磷酸酶在一定程度上可作为豆磺隆污染土壤的监测指标。     

砷对土壤脲酶活性影响的研究

采用模拟方法对As污染土壤脲酶特征进行了研究．结果表明,土壤中As浓度在0～200mg·kg^-1浓度范围内,反应初期脲酶活性变化无明显规律;一年后砷激活土壤脲酶活性,二者达到显著或极显著正相关．随As浓度增加,土壤脲酶Km值基本不变或略有增加,Vmax增大,从机制上揭示出As加速脲酶-尿素复合物的解离．厩肥和无肥土样脲酶对As的反应类似,只是变化幅度有所差异．     

温度对Cd抑制土壤脲酶影响机理研究

通过土壤培养实验、紫外光谱和荧光光谱技术,研究了不同温度下Cd对土壤脲酶催化活性、动力学性质的影响及其机理。结果表明：（1）在供试温度范围内,土壤脲酶活性、动力学参数Vmax和Vmax/Km值与温度呈正相关,且土壤脲酶活性随着培养时间延长呈现先增后减的趋势; （2）土壤脲酶活性、动力学参数Vmax和Vmax/Km值与Cd^2＋呈显著负相关,表明Cd对土壤脲酶的抑制作用为非竞争性抑制,且抑制程度随处理温度升高而加强; （3）低浓度Cd处理刀豆脲酶后,随着体系中Cd^2＋的增加,脲酶的紫外吸收光谱发生红移,荧光发射峰发生蓝移。 关     

镉、汞复合污染对土壤脲酶和酸性磷酸酶活性的影响

通过土壤培养试验, 研究了重金属镉（Cd）、汞（Hg）复合污染对小粉土和黄红壤脲酶和酸性磷酸酶活性的影响.结果表明：整个培养过程中，Cd、Hg单一及复合污染都对两种土壤中脲酶和酸性磷酸酶的活性具有明显抑制作用，且随重金属浓度增强而增强（浓度≤1 mg·kg^-1Cd除外）.与单一Cd或Hg污染相比，同剂量Cd和Hg复合污染时两种酶活性的净变化量均大于0，表明Cd和Hg复合污染在两种土壤中对土壤脲酶和酸性磷酸酶活性的抑制作用均表现为一定的协同作用.所有处理黄红壤脲酶和酸性磷酸酶活性均高于小粉土，这可能与黄红壤有机质和粘粒含量相对较高有关.     

铜尾矿污染区土壤酶活性研究

对浙江省哩浦铜尾矿污染区土壤酶活性进行了研究,结果表明,尾矿区及其周边土壤环境受到不同程度的Cu、Zn、Pb、Cd污染,从尾矿库中心到外围重金属污染程度逐渐减轻,而土壤酶活性则不断提高,其中以脱氢酶和脲酶活性增加最明显,回归分析表明,单一脱氢酶、脲酶、酸性磷酸酶以及蛋白酶活性与重金属复合元素含量之间存在显著线性关系,主成分分析结果显示,尾矿区土壤酶信息系统的第一、二主成分方差贡献率之和达98．24％,以第一、二主成分建立了两个土壤总体酶活性指标,并用此指标对各供试样本进行空间分类,其结果与以重金属含量为依据的划分结果基本吻合,可见,采用酶活性构筑的土壤信息系统的总体酶活性来表征矿区土壤的重金属污染状况是可行的。     

一株氯嘧磺隆降解菌分离鉴定及降解条件优化

为解决氯嘧磺隆残留对土壤、水体污染及后茬敏感作物药害问题,为污染土壤微生物修复提供降解菌种资源,文中采用富集培养、逐级驯化等方法,从氯嘧磺隆污染土壤中分离到1株高效氯嘧磺隆降解菌T9DB-01,经形态特征、生理生化及16S rDNA序列分析,鉴定为假单胞菌Pseudomonas sp.。采用单因素实验探究温度、pH值、底物浓度、装液量和接种量对菌株T9DB-01降解氯嘧磺隆的影响,采用正交试验及验证,优化菌株T9DB-01对氯嘧磺隆降解条件。结果表明,在30℃,pH 8.0,底物浓度200 mg/L,装液量100 mL/250 mL,接种量4%的条件下,5 d后降解率达到93.7%。该降解菌株对氯嘧磺隆污染土壤原位生物修复具有一定的应用潜力。     

甲磺隆对微囊藻生长和光合系统的影响

研究选取了水体常见蓝藻优势种类——铜绿微囊藻(Microcystis aeruginosa PCC7806)作为研究对象, 了解磺酰脲类除草剂甲磺隆(Metsulfuron-methyl)对铜绿微囊藻生长和光合系统的影响。研究表明, 当甲磺隆浓度大于80 mg/L时, 对铜绿微囊藻的生长具有显著抑制。通过回归分析和Probit分析, 甲磺隆对铜绿微囊藻生长的EC₅₀为81.998 mg/L。细胞色素研究结果显示, 实验第6天, 各浓度处理下单位细胞内Chl.a和类胡萝卜素含量均低于对照组, 且当甲磺隆浓度为80 mg/L时, 单位细胞内类胡萝卜素含量显著低于对照组。快速叶绿素荧光诱导动力学变化结果分析显示, 实验第6天甲磺隆胁迫下单位反应中心捕获的用于电子传递的能量(ET₀/RC)及单位反应中心用于电子传递的量子产额(φE₀)受到显著抑制, 综合细胞色素变化结果显示, 甲磺隆能显著抑制光合系统反应中心电子受体侧电子性能。综上所述, 甲磺隆可能作用于光合系统反应中心电子受体侧, 从而对铜绿微囊藻光合系统造成影响。     

镉与豆磺隆复合胁迫下小麦根-土界面镉形态的变化

通过根际箱试验,研究了Cd与豆磺隆复合胁迫下小麦根 土界面Cd形态变化的空间和时间效应.在空间上将根－土界面(0～5 mm)细化到1 mm,在时间上将取样时间分为14、21、28、35和42 d,并将小麦体吸收的Cd与根 土界面各形态Cd作相关分析,从而得出影响小麦体生长的Cd形态.结果表明,在小麦不同的生长时间内,可交换态Cd表现出的空间效应明显不同.在小麦生长的第14天,根－土界面可交换态Cd大体上由根中心区(6.186 mg·kg^-1)向根外区(6.482 mg·kg^-1)逐渐增加;从小麦生长第21天到42天,根-土界面可交换态Cd呈现出由根中心区到某一层升高,之后又由该层到土体下降的趋势.根-土界面各层碳酸盐和铁锰结合态Cd向可交换态Cd转化的趋势由根中心区向根外区逐渐减弱,而向残留态Cd转化的趋势逐渐加强,有机结合态Cd浓度变化在近根区较大.碳酸盐结合态Cd、铁锰结合态Cd、有机结合态Cd浓度随时间而逐渐下降;残留态Cd浓度则表现出明显的上升趋势.相关分析表明,近根层的可交换态Cd和有机结合态Cd是小麦能直接利用的两种Cd形态.豆磺隆对可交换态Cd含量变化以及碳酸盐和铁锰结合态Cd的转化有明显影响.     

氯嘧磺隆降解菌株LW-3的分离及生物学特性研究

从长期受氯嘧磺隆污染的土壤中分离到一株氯嘧磺隆高效降解菌株,命名为LW-3,菌株LW-3可以氯嘧磺隆为唯一氮源生长,接种量为2%时,50 mg/L氯嘧磺隆经过7 d,降解率达70%～80%.生理生化实验和16S rDNA序列同源性分析,将菌株LW-3归属于假单胞茵属(Pseudomonas sp.);菌株的适宜降解条件为;温度30℃～35℃,pH 6.5～7.2,pH对菌株LW-3降解氯嘧磺隆有明显地影响.     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Cytoskeleton and mitochondrial morphology and function

It has been well established that the cytoskeleton is an essential modulator of cell morphology and motility, intracytoplasmic transport and mitosis, however cytoskeletal linkage to the organelles has not been unequivocally demonstrated. Indeed, cytoskeleton appears to be essential in determining and modulating gene phenotype as a function of cellular environment. According to recent studies, the organization of the cytoskeleton network together with associated protein(s) could be essential in regulating mitochondrial function and particularly the permeability of the mitochondrial outer membrane to ADP. The aim of this chapter is to summarize the main properties of the cytoskeletal environment of mitochondria and the possible role(s) of this network in mitochondrial function in myocytes.     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

Cross-reactivity between storage and dust mites and between mites and shrimp

Many patients have sensitivities to multiple species of storage and house dust mites. It is not clear if this is because patients have multiple sensitivities to species-specific mite allergens or if these mites share many cross-reacting allergens. Our objective was to further define the cross-allergenicity between several species of storage and house dust mites using crossed-immunoelectrophoresis (CIE), crossed-radioimmunoelectrophoresis (CRIE), immunoblotting, and ELISA. CIE and CRIE reactions revealed that storage mites shared two cross-antigenic molecules and one of these bound IgE in a serum pool from mite allergic patients. Antibody in anti-sera built to each species of mite recognized many SDS–PAGE resolved proteins of other mite species and this suggested the potential for other cross-reactive allergens. Among patient sera, IgE bound to many different proteins but few had IgE that bound to a protein with common molecular weights across the mite species and this suggested mostly species-specific allergens. Antiserum built to each mite species precipitated one protein in shrimp extracts that bound anti-Der p 10 (tropomyosin) and IgE in the serum pool. Anti-Der p 10 showed strong binding to shrimp tropomyosin but very little to any of the mite proteins. ELISA showed the mite extracts contained very little tropomyosin. The storage and dust mites investigated contain mostly species-specific allergens and very small amounts of the pan-allergen tropomyosin compared to shrimp and snail.     

Oxidation and nitration of ribonuclease and lysozyme by peroxynitrite and myeloperoxidase

In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.     

Antibacterial and Antifugal Mono- and Di-substituted Symmetrical and Unsymmetrical Triazine-derived Schiff-bases and their Transition Metal Complexes

A new series of antibacterial and antifungal triazine-derived mono- and di-substituted (symmetrical and unsymmetrical) Schiff-bases and their cobalt(II), copper(II), nickel(II) and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments and IR and electronic spectral measurements. IR spectra indicated the ligands to act as tridentate towards divalent metal ions via a trazine-N, the azomethine-N and, indole-NH and deprotonated-O of salicylaldehyde. The magnetic moments and electronic spectral data suggest octahedral geometry for the Co(II), Ni(II) and Zn(II)complexes and square-pyramid for Cu(II) complexes. NMR spectral data of the ligands and their diamagnetic zinc(II) complexes well-define their proposed structures/geometries. Elemental analyses data of the ligands and metal complexes agree with their proposed structures/geometries. The synthesized ligands, along with their metal complexes were screened for their antibacterial activity against Escherichia coli, Bacillus subtillis, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata. The results of these studies show the metal complexes to be more antibacterial/antifungal against two or more species as compared to the uncomplexed Schiff-base ligands.