In vivo cellular uptake of bismuth ions from shotgun pellets

Shotgun pellets containing bismuth (Bi) are widely used and may cause a rather intense exposure of some wild animals to Bi. A Bi shotgun pellet was implanted intramuscularly in the triceps surae muscle of 18 adult male Wistar rats. Another group of 9 animals had a Bi shotgun pellet implanted intracranially in the neocortex. Eight weeks to 12 months later the release of Bi ions was analysed by autometallography (AMG) of tissue sections from different organs (brain, spinal cord, kidney, liver, testes). In the group with intramuscular Bi shotgun pellets no AMG staining could be found for the first 2-4 months; 6 months after exposure Bi was traced in the kidney. Twelve months after the implantation the kidneys were heavily loaded and Bi was also traced in testosterone-producing Leydig cells, in glial cells and in neurons of brain and spinal cord. In the central nervous system (CNS) motor neurons were the most loaded. In rats with intracranially implanted shotgun pellets a massive uptake of Bi was observed involving both glia and neurons throughout the brain. The cells close to the shotgun pellet had the highest uptake. The animals showed a pronounced Bi uptake in the ependyma cells lining the ventricular system and in the cubic epithelia covering the choroid plexus. Dissemination of Bi ions to the rest of the body was demonstrated by AMG tracing of Bi accumulations in the tubular cells of the kidney. These findings emphasize that metallic Bi, including shotgun pellets, represents sites of intense Bi pollution if implanted or shot into a living organism, and further that such metallic Bi bodies, if they enter the CNS, cause a spread of Bi ions throughout it.     

Localization of bismuth radiotracer in rat kidney following exposure to bismuth

It has been proposed that alpha emitting 212Bi (t1/2 = 60 min) coupled to tumor-specific antibodies may be a useful radiotherapeutic agent. However, since Bi can accumulate in the kidney, it is necessary to characterize the factors influencing localization of Bi within this tissue in order to evaluate the potential for radiation damage to the renal system. In this study, the localization of Bi radiotracers was determined in kidneys of rats previously exposed and not exposed to mumole quantities of Bi. Following repeated injection of Bi (4 x 14 mumols (3 mg Bi)/kg bw) the element accumulated mainly in the kidney followed by liver, spleen, pancreas, bone, and brain. Kidney copper and liver zinc concentrations were higher in Bi-exposed rats than in non-exposed rats. Within the cytosol, in Bi-exposed rats, Bi radiotracer in the kidney was associated with a metallothionein-like protein (Mt). In contrast, non-exposed rats contained no detectable metallothionein-like proteins in the kidney and the Bi tracer was associated with the hemoglobin fraction of the cell. Thus, when Bi is administered in tracer quantities such as that incorporated for use as a radiopharmaceutical, no induction of, and association with, metallothionein-like proteins should occur. These results suggest that the potential nephrotic effects of 212Bi will be influenced by the individual's previous exposure to Bi-containing drugs, or other metallothionein-inducing insults.     

伞菌目的四个新种

本文报道了伞菌目的4个新种,它们是拟胶粘小菇 Mycena pseudo-glutinosa Bi sp.nov.,泡状囊体粉褶蕈 Entoloma vesiculo-cystidium Bi sp.nov.,鼎湖鳞伞 Pholiota dinghuensis Bi sp.nov.以及灰白小脆柄菇 Psathyrella griseoalba Bi sp.nov.。     

Characterization of a metalloregulatory bismuth(III) site in Staphylococcus aureus pI258 CadC repressor

Staphylococcus aureus pI258 CadC is a metal sensor protein that regulates the expression of the cad operon which encodes metal ion resistance proteins involved in the efficient efflux of Cd(II), Pb(II), Zn(II) and, according to one report, Bi(III) ions. In this paper, direct evidence is presented that Bi(III) binds to CadC and negatively regulates cad operator/promoter (O/P) binding. Optical absorption spectroscopy reveals that dimeric CadC binds approximately 0.8 mol equivalents of Bi(III) per CadC monomer to form a coordination complex characterized by three S(-)-->Bi(III) ligand-to-metal charge transfer transitions, with the longest wavelength absorption band centered at 415 nm (epsilon(415)=4000 M(Bi)(-1) cm(-1)). UV-Vis absorption spectra of wild-type and mutant Cys-->Gly (Ser) substitution CadC mutants compared to [Bi(DTT)(2)], [Bi(GSH)(3)] and [Bi(NAC)](3) model complexes reveal that Cys7, Cys11, Cys60 and Cys58 directly coordinate Bi(III) in a tetrathiolate coordination complex. The apparent affinity derived from a Bi(III)-displacement optical titration with Cd(II) is estimated to be K(Bi)< or =10(12) M(-1). Apo-CadC binds with high affinity [ K(a)=1.1(+/-0.3)x10(9) M(-1); 0.40 M NaCl, pH 7.0, 25 degrees C] to a 5'-fluorescein-labeled cad O/P oligonucleotide,while the binding of one molar equivalent of Bi(III) per CadC monomer (Bi(1)-CadC) reduces the affinity by approximately 170-fold. Strikingly, Bi(III)-responsive negative regulation of cad O/P binding is abrogated for Bi(1)-C60G CadC and severely disrupted in Bi(1)-C7G CadC, whose relative affinity is reduced only 10-fold. The mechanism of Bi(III)-responsive metalloregulation is discussed, based on the findings presented here. Electronic supplementary material to this paper can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00775-001-0336-9.     

Thyrotropin interactions with human fat cell membrane preparations and the finding of soluble thyrotropin binding component.

Three criteria are presented that permit a distinction to be made between the conventional rapid equilibrium Random Bi Bi mechanism and a unique Ordered Bi Bi mechanism in which the rapid equilibrium assumption is made[C. Frieden (1976) Biochem. Biophys. Res. Commun., 68, 914–917]. A choice between these mechanisms cannot be made using kinetic procedures now in vogue for differentiating between Ordered and Random Bi Bi mechanisms. However, transition state analogs, pulse-chase experiments, and pre-equilibrium isotope exchange procedures can be employed to make this distinction.     

我国鼎湖山的担子菌类 Ⅲ.牛肝菌科的种之二

本文报道了我国鼎湖山牛肝菌20个种,其中4个新种,1个新变种以及15个国内新记录。褐小牛肝菌属 Fuscoboletinus Pomerleau et Smith 和南方牛肝菌属 Austroboletus(Corner)Wolf为新纪录属。4个新种是:辐射状条孢牛肝菌 Boletellus radiatus Bi sp. nov.,亚黄褐牛肝菌 Boletus subfulvus Bi sp. nov.,变红褐色牛肝菌 Boletus rufo-brunnescens Bi sp.nov.以及近浅灰色牛肝菌 Boletus subgriseus Bi sp. nov.。1个新变种为小近白褐疣柄牛肝菌Leccinum subleucophaeum Dick et Snell var. minimum Bi var. nov.。文中有分属和分种的检索表。新种和新变种均有汉文和拉丁文描述。     

广东粉褶蕈属的分类研究

本文报道广东省粉褶蕈属Entoloma(Fr.)Kummer的23种,其中新种4个,国内新记录种17个。新种为肉色粉褶蕈Entoloma carneum Bi sp.nov.,拟灰白粉褶蕈Entoloma pseudo-griseoalbum Bi sp.nov.,绒毛粉褶蕈 Entoloma tomentosum Bi sp.nov.以及橙黄粉褶蕈Entoloma aurantiacum Bi sp.nov.。17个国内新纪录是:白粉褶蕈E.albidum(Murr.)Hesler,小白粉褶蕈E.albinellum(Pk.)Hesler,变灰褐粉褶蕈E.canobrunnescens Horak,卡罗琳尼粉褶蕈E.carolinianum Hesler,角柄粉褶蕈E.ceratopus Horak,黄肉色粉褶蕈E.flavocerinum Horak,脆柄粉褶蕈E.fragilipes Corner et Horak,烟色粉褶蕈E.fumeum Hesler,灰色粉褶蕈E.grayanum(Pk.)Sacc.,贺斯同美粉褶蕈E.hallstromii Horak,类洁粉褶蕈E.purddes Horak,方形粉褶蕈E.quadratum(Berk.et Curt.)Horak,圆孢粉褶蕈E.rotundisporum Horak,近白粉褶蕈E.subalbidum Murr.,亚亮粉褶蕈E.sublucidum Murr.,近方形粉褶蕈E.subquadratum Hesler及紫褐粉褶蕈E.violaceobrunneum Hesler。文中有分种检索表     

Arsenic, antimony, and bismuth uptake and accumulation by plants in an old antimony mine, China

Arsenic (As), antimony (Sb), and bismuth (Bi) are metalloids that share similar chemical properties, the objective of this study was to characterize the uptake and accumulation of these metalloids by plants colonized on heavy contaminated sites in an old Sb mine. Sixty-five plant samples from seven species as well as the associated soil samples were collected at ten sites of Xikuangshan (XKS), Hunan province, China. Concentrations of As, Sb, and Bi in plants and soils were measured. As, Sb, and Bi were found to be evidently elevated due to the long history and intensive mining and smelting activities; the respective ranges for the levels of As, Sb, and Bi at the sites were 40.02-400.2?mg?kg(-1) As, 610-54,221?mg?kg(-1) Sb, and n.d. to 1,672?mg?kg(-1) Bi. No correlation was found between As and Sb at the sites, while Bi was found to be positively correlated with As whereas negative with Sb at the sites. In general, the contents in the plants in XKS were in the order of As?>?Sb?>?Bi, and the contents of As was positively correlated with Sb and Bi in plants. The highest contents of As and Sb recorded was 607.8?mg?kg(-1) As in Pteris vittata and 90.98?mg?kg(-1) Sb in Hippochcaete ramosissima, while the highest Bi content as 2.877?mg?kg(-1) Bi was measured in Buddleja davidii. Bioconcentration factors defined as the ratios of metalloids in shoots of plants to those in soils for various plants were lower than 1. The results showed plants colonized at the heavy contaminated sites in XKS had great tolerance to As, Sb, and Bi, and demonstrated similarities in plant uptake and accumulation of these three elements.     

Metallobiochemistry of ultratrace levels of bismuth in the rat II. Interaction of 205+206Bi3+ with tissue,intracellular and molecular components

BackgroundKnowledge on Bi metabolism in laboratory animals refers to studies at “extreme” exposures, i.e. pharmacologically relevant high-doses (mg kg⁻¹ b.w.) in relation to its medical use, or infinitesimal doses (pg kg⁻¹b.w.) concerning radiobiology protection and radiotherapeutic purposes. There are no specific studies on metabolic patterns of environmental exposure doses (ultratrace level, μg kg⁻¹ b.w.), becoming in this context Bi a “heavy metal fallen into oblivion”. We previously reported the results of the metabolic fate of ultratrace levels of Bi in the blood of rats [1]. In reference to the same study here we report the results of the retention and tissue binding of Bi with intracellular and molecular components.MethodsAnimals were intraperitoneally injected with 0.8 μg Bi kg⁻¹ b.w. as ^205+206Bi(NO)₃, alone or in combination with ⁵⁹Fe for the radiolabeling of iron proteins. The use of ^205+206Bi radiotracer allowed the determination of Bi down to pg fg⁻¹ in biological fluids, tissues, subcellular fractions, and biochemical components isolated by differential centrifugation, size exclusion chromatography, solvent extraction, precipitation, immunoprecipitation and dialysis.Main findingsAt 24 h post injection the kidney contained by far the highest Bi concentration (10 ng g⁻¹ wt.w.) followed by the thymus, spleen, liver, thyroid, trachea, femur, lung, adrenal gland, stomach, duodenum and pancreas (0.1 to 1.3 ng g⁻¹ wt.w.). Brain and testis showed smaller but consistently significant concentrations of the element (0.03 ng g⁻¹ wt.w). Urine was the predominant route of excretion. Intracellularly, liver, kidney, spleen, testis, and brain cytosols displayed the highest percentages (35%–58%) of Bi of homogenates. Liver and testis nuclei were the organelles with the highest Bi content (24 % and 27 %). However, when the recovered Bi of the liver was recorded as percent of total recovered Bi divided by percent of total recovered protein the lysosomes showed the highest relative specific activity than in other fractions. In the brain subcellular fractions Bi was incorporated by neuro-structures with the protein and not lipidic fraction of the myelin retaining 18 % of Bi of the total homogenate. After the liver intra-subcellular fractionation: (i) 65 % of the nuclear Bi was associated with the protein fraction of the nuclear membranes and 35 % with the bulk chromatin bound to non-histone and DNA fractions; (ii) about 50 % of the mitochondrial Bi was associated with inner and outer membranes being the other half recovered in the intramitochondrial matrix; (iii) in microsomes Bi showed a high affinity (close to 90 %) for the membranous components (rough and smooth membranes); (iv) In the liver cytosol three pools of Bi-binding proteins (molecular size > 300 kDa, 70 kDa and 10 kDa) were observed with ferritin and metallothionein–like protein identified as Bi-binding biomolecules. Three similar protein pools were also observed in the kidney cytosol. However, the amount of Bi, calculated in percent of the total cytosolic Bi, were significantly different compared to the corresponding pools of the liver cytosol.ConclusionsAt the best of our knowledge the present paper represents the first in vivo study, on the basis of an environmental toxicology approach, aiming at describing retention and binding of Bi in the rat at tissue, intracellular and molecular levels.     

粤北山区多孔菌科的三个新种

本文发表了广东省北部山区的多孔菌科的三个新种,它们是:薄淀粉孔菌Amylonotus tenuis Zheng et Bi;近烟色赖特卧孔菌Wrighto-poria subadusta Bi et Zheng;和迷路状粉孢菌Amylosporus daedali-formis Zheng et Bi。     

Bismuth and Silver in Cosmetic Products: A Source of Environmental and Resource Concern?

Bismuth (Bi) and silver (Ag) are used in increasing amounts and are consequently being emitted from various sources and showing high accumulation rates in soils when sewage sludge is applied on arable land. This study aimed to analyze the amounts of Bi and Ag in three cosmetic products (foundation, powder, and eye shadow) in order to study the flows in urban wastewater in Stockholm, Sweden. Analyses showed that Bi was present in very high concentrations (7,000 to 360,000 milligrams per kilogram) in one third of the analyzed foundation and powder samples, whereas Ag concentrations all were below the detection limit. These cosmetic products explained approximately 24% of the measured total Bi amounts per year reaching the WWTP (wastewater treatment plant), making cosmetics a major Bi source, whereas for Ag the corresponding contribution was <0.1% of the measured annual Ag amounts. The results were roughly adapted for Europe and the United States, estimating the Bi flows from cosmetics to WWTPs. On a global scale, these flows correspond to a non‐negligible part of the world Bi production that, every year, ends up in sewage sludge, limiting the reuse of a valuable metal resource. From an environmental and resource perspective, foundations and powder products should be considered as significant sources of measured Bi amounts in sludge. This large Bi flow must be considered as unsustainable. For Ag, however, the three analyzed cosmetic products are not a significant source of the total Ag load to WWTPs.     

Computational chemistry calculations of stability for bismuth nanotubes, fullerene-like structures and hydrogen-containing nanostructures

Using molecular mechanics (MM+), semi-empirical (PM6) and density functional theory (DFT) (B3LYP) methods we characterized bismuth nanotubes. In addition, we predicted the bismuth clusters {Bi(20)(C(5V)), Bi(24)(C(6v)), Bi(28)(C(1)), B(32)(D(3H)), Bi(60)(C(I))} and calculated their conductor properties.     

Purification, properties, and kinetics of D-ribulokinase from Aerobacter aerogenes.

The enzyme D-ribulokinase from Aerobacter aerogenes was purified to near homogeneity. The molecular weight, as determined by Sephacryl gel chromatography, is 116,000. The subunit molecular weight, determined by sodium dodecyl sulfate-gel electrophoresis, is 59,000, suggesting that D-ribulokinase is a dimer of identical subunits. Initial rate kinetic studies, involving substrate analogs and products, were carried out. These investigations support a kinetic mechanism of the Random Bi Bi type. Isotope partitioning, utilizing D-[3H]ribulose, indicates that the mechanism is steady state Random Bi Bi.     

Interactions of bismuth complexes with metallothionein(II).

Bismuth complexes are widely used as anti-ulcer drugs and can significantly reduce the side effects of platinum anti-cancer drugs. Bismuth is known to induce the synthesis of metallothionein (MT) in the kidney, but there are few chemical studies on the interactions of bismuth complexes with metallothionein. Here we show that Bi(3+) binds strongly to metallothionein with a stoichiometry bismuth:MT = 7:1 (Bi(7)MT) and can readily displace Zn(2+) and Cd(2+). Bismuth is still bound to the protein even in strongly acidic solutions (pH 1). Reactions of bismuth citrate with MT are faster than those of [Bi(EDTA)](-), and both exhibit biphasic kinetics. (1)H NMR data show that Zn(2+) is displaced faster than Cd(2+), and that both Zn(2+) and Cd(2+) in the beta-domain (three metal cluster) of MT are displaced by Bi(3+) much faster than from the alpha-domain (four metal cluster). The extended x-ray absorption fine structure spectrum of Bi(7)MT is very similar to that for the glutathione and N-acetyl-L-cysteine complexes [Bi(GS)(3)] and [Bi(NAC)(3)] with an inner coordination sphere of three sulfur atoms and average Bi-S distances of 2.55 A. Some sites appear to contain additional short Bi-O bonds of 2.2 A and longer Bi-S bonds of 3.1 A. The Bi(3+) sites in Bi(7)MT are therefore highly distorted in comparison with those of Zn(2+) and Cd(2+).     

Interactions of bismuth with human lactoferrin and recognition of the Bi(III)-lactoferrin complex by intestinal cells.

Several bismuth compounds are currently used as antiulcer drugs, but the mechanism of action still remains unclear. The antimicrobial activity of Bi(III) complexes toward Gram-negative bacteria is reported to be dependent on the iron uptake system [Domenico, P., et al. (1996) J. Antimicrob. Chemother. 38, 1031-1040]. Electronic absorption and 13C NMR spectroscopic data show that Bi(III) binds to human lactoferrin at the specific Fe(III) sites along with either carbonate or oxalate as the synergistic anion. The uptake of Bi(III) by apo-hLF was rapid [minutes in 10 mM Hepes buffer and 5 mM bicarbonate (pH 7.4)], and almost equal in both lobes. The presence of ATP facilitates the release of Bi(III) from the Bi2-hLF complex when the pH is lowered. The Bi2-hLF complex blocked the uptake of the radiolabeled 59Fe-hLF complex into rat IEC-6 cells. Surprisingly, apo-hLF (but not apotransferrin) was almost as effective in blocking 59Fe uptake as bismuth-loaded lactoferrin. These results suggest that Bi(III)-loaded hLF might be recognized by the lactoferrin receptor and be taken up into cells.     

Immunological properties of low molecular-weight proteins binding heavy metals in rat kidney and liver

Two homogenous fractions of hepatic metallothioneins ((Cd,Zn) MT-1 and (Cd,Zn) MT-2) and renal metal binding proteins ((Bi,Cu) BP-1 and (Bi,Cu) BP-2) were isolated from rats exposed to heavy metals and specific antisera to them were produced in rabbits.These antisera were tested by immunodiffusion and immunoelectrophoresis for their ability to bind different fractions of hepatic Cd,Zn -metallothionein and renal (Bi,Cu)-, (Hg,Cu)- and (Cd,Cu)-binding proteins. It was found that anti (Bi,Cu) BP antisera did not cross-react with hepatic (Cd,Zn) MT-1 and (Cd,Zn) MT-2. Strong immunological cross-reactions were detected between anti (Bi,Cu) BP antisera and individual forms of (Cd,Cu)-, (Hg,Cu)- and (Bi,Cu)-binding proteins isolated from rat kidneys.     

Competitive binding of bismuth to transferrin and albumin in aqueous solution and in blood plasma

Several bismuth compounds are currently used as antiulcer drugs, but their mechanism of action is not well established. Proteins are thought to be target sites. In this work we establish that the competitive binding of Bi(3+) to the blood serum proteins albumin and transferrin, as isolated proteins and in blood plasma, can be monitored via observation of (1)H and (13)C NMR resonances of isotopically labeled [epsilon-(13)C]Met transferrin. We show that Met(132) in the I132M recombinant N-lobe transferrin mutant is a sensitive indicator of N-lobe metal binding. Bi(3+) binds to the specific Fe(3+) sites of transferrin and the observed shifts of Met resonances suggest that Bi(3+) induces similar conformational changes in the N-lobe of transferrin in aqueous solution and plasma. Bi(3+) binding to albumin is nonspecific and Cys(34) is not a major binding site, which is surprising because Bi(3+) has a high affinity for thiolate sulfur. This illustrates that the potential target sites for metals (in this case Bi(3+)) in proteins depend not only on their presence but also on their accessibility. Bi(3+) binds to transferrin in preference to albumin both in aqueous solution and in blood plasma.     

Metallobiochemistry of ultratrace levels of bismuth in the rat I. Metabolic patterns of 205+206Bi3+ in the blood

BackgroundThe number of the applications of bismuth (Bi) is rapidly and remarkably increasing, enhancing the chance to increase the levels to which humans are normally daily exposed. The interest to Bi comes also from the potential of Bi-based nanoparticles (BiNPs) for industrial and biomedical purposes. Like other metal-based NPs used in nanomedicine, BiNPs may release ultratrace amounts of Bi ions when injected. The metabolic fate and toxicity of these ions still needs to be evaluated. At present, knowledge of Bi metabolism in laboratory animals refers almost solely to studies under unnatural “extreme” exposures, i.e. pharmacologically relevant high-doses (up to thousand mg kg⁻¹) in relation to its medical use, or infinitesimal-doses (pg kg⁻¹ as non-carrier-added Bi radioisotopes) for radiobiology protection, diagnostic and radiotherapeutic purposes. No specific study exists on the “metabolic patterns” in animal models exposed to levels of Bi, i.e. at “environmental dose exposure” that reflect the human daily exposure (μg kg⁻¹).MethodologyRats were intraperitoneally injected with 0.8 μg Bi kg⁻¹ bw as ^205+206Bi(NO)₃ alone or in combination with ⁵⁹Fe for radiolabelling of iron proteins. The use of ^205+206Bi radiotracers allowed the detection and measurement down to pg fg⁻¹ of the element in the blood biochemical compartments and protein fractions as isolated by differential centrifugation, size exclusion- and ion exchange chromatography, electrophoresis, solvent extraction, precipitation and dialysis.Results24 h after the administration, the blood concentration of Bi was 0.18 ng mL⁻¹, with a repartition plasma/red blod cells (RBC) in a ratio of 2:1. Elution profiles of plasma from gel filtration on Sephadex G-150 showed four pools of Bi-binder proteins with different molecular sizes (> 300 kDa, 160 kDa, 70 kDa and < 6.5 kDa). In the 70 kDa fraction transferrin and albumin were identified as biomolecule carriers for Bi. In red blood cells, Bi was distributed between cytosol and membranes (ghosts) in a ratio of about 5:1. In the cytosol, low molecular components (LMWC) and the hemoglobin associated the Bi in a ratio of about 1.8:1. In the hemoglobin molecule, Bi was bound to the beta polypeptide chain of the globin. In the ghosts, Bi was detected at more than one site of the protein fraction, with no binding with lipids. Dialysis experiments and the consistently high recovery (80–90 %) of ²⁰⁶Bi from chromatography of ²⁰⁶Bi-containing biocomponents suggest that Bi was firmly complexed at physiological pH with a low degree of breaking during the applications of experimental protocols for the isolation of the ²⁰⁶Bi-biocomplexes. These latter were sensitive to acid buffer pH 5, and to the presence of complexing agents in the dialysis fluid.ConclusionsOn the basis of an environmental biochemical toxicology approach, we have undertaken a study on the metabolic patterns of Bi³⁺ ions in rats at tissue, subcellular and molecular level with the identification of cellular Bi-binding components. As a first part of the study the present work reports the results concerned with the metabolic fate of ultratrace levels of ^205+206Bi(NO)₃ in the blood.     

Coordination of Thiosemicarbazones and Bis(thiosemicarbazones) to Bismuth(III) as a Strategy for the Design of Metal-Based Antibacterial Agents

Complexes [Bi(2Fo4Ph)Cl(2) ] (1), [Bi(2Ac4Ph)Cl(2) ] (2), [Bi(2Bz4Ph)Cl(2) ] (3), [Bi(H(2) Gy3DH)Cl(3) ] (4), [Bi(H(2) Gy4Et)(OH)(2) Cl] (5), and [Bi(H(2) Gy4Ph)Cl(3) ] (6) were prepared with pyridine-2-carbaldehyde 4-phenylthiosemicarbazone (H2Fo4Ph), 1-(pyridin-2-yl)ethanone 4-phenylthiosemicarbazone (H2Ac4Ph), phenyl(pyridin-2-yl)methanone 4-phenylthiosemicarbazone (H2Bz4Ph), as well as with glyoxaldehyde bis(thiosemicarbazone) (H(2) Gy4DH) and its 4-Et (H(2) Gy4Et) and 4-Ph (H(2) Gy4Ph) derivatives. The complexes exhibited antibacterial activities against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and Pseudomonas aeruginosa. Coordination to Bi(III) proved to be an effective strategy to increase the antibacterial activity of the thiosemicarbazones and bis(thiosemicarbazones).     

杀虫剂种类与稻田生物群落丰盛度及多样性关系研究

吡杀灵是一种由吡虫啉与杀虫单组成的复配剂农药,对褐飞虱、白背飞虱、叶蝉、螟虫有较高的防效。本对应用吡杀灵的稻田进行系统调查结果表明：施用吡杀灵与甲胺磷的稻田害虫种类、寄生性和捕食性天敌种类有明显的差异。根据Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ的多样性指数Ｈ和均匀性指数Ｊ等指标测定,吡杀灵防治区生物种群的多样性明显高于甲胺磷防治区,而甲胺磷防治区害虫多样性高于寄生性昆虫和蜘蛛类群。吡杀灵防治区稻田天敌多样