bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex differences in the development of angiotensin II-induced hypertension in conscious mice
Authors: Xue Baojian , Pamidimukkala Jaya , Hay Meredith
Published: December 2004

Sex has an important influence on blood pressure (BP) regulation. There is increasing evidence that sex hormones interfere with the renin-angiotensin system. Thus the purpose of this study was to determine whether there are sex differences in the development of ANG II-induced hypertension in conscious male and female mice. We used telemetry implants to measure aortic BP and heart rate (HR) in conscious, freely moving animals. ANG II (800 ng·kg−1·min−1) was delivered via an osmotic pump implanted subcutaneously. Our results showed baseline BP in male and female mice to be similar. Chronic systemic infusion of ANG II induced a greater increase in BP in male (35.1 ± 5.7 mmHg) than in female mice (7.2 ± 2.0 mmHg). Gonadectomy attenuated ANG II-induced hypertension in male mice (15.2 ± 2.4 mmHg) and augmented it in female mice (23.1 ± 1.0 mmHg). Baseline HR was significantly higher in females relative to males (630.1 ± 7.9 vs. 544.8 ± 16.2 beats/min). In females, ANG II infusion significantly decreased HR. However, the increase in BP with ANG II did not result in the expected decrease in HR in either intact male or gonadectomized mice. Moreover, the slope of the baroreflex bradycardia to phenylephrine was blunted in males (−5.6 ± 0.3 to −2.9 ± 0.5) but not in females (−6.5 ± 0.5 to −5.6 ± 0.3) during infusion of ANG II, suggesting that, in male mice, infusion of ANG II results in a resetting of the baroreflex control of HR. Ganglionic blockade resulted in greater reduction in BP on day 7 after ANG II infusion in males compared with females (−61.0 ± 8.9 vs. −36.6 ± 6.6 mmHg), suggesting an increased contribution of sympathetic nerve activity in arterial BP maintenance in male mice. Together, these data indicate that there are sex differences in the development of chronic ANG II-induced hypertension in conscious mice and that females may be protected from the increases in BP induced by ANG II.
Apical trypsin increases ion transport and resistance by a phospholipase C-dependent rise of Ca2+
Authors: Swystun Veronica , Chen Lan , Factor Phillip , Siroky Brian , Bell P. Darwin , Matalon Sadis
Published: December 2004

We investigated the mechanisms by which serine proteases alter lung fluid clearance in rat lungs and vectorial ion transport in airway and alveolar epithelial cells. Inhibition of endogenous protease activity by intratracheal instillation of soybean trypsin inhibitor (SBTI) or α1-antitrypsin decreased amiloride-sensitive lung fluid clearance across rat fluid-filled lungs; instillation of trypsin partially restored this effect. Gelatin zymography demonstrated SBTI-inhibitable trypsin-like activity in rat lung lavage fluid. Apical trypsin and human neutrophil elastase, but not agonists of protease activated receptors, increased Na+and Cl−short-circuit currents ( Isc) and transepithelial resistance ( RTE) across human bronchial and nasal epithelial cells and rat alveolar type II cells, mounted in Ussing chambers, for at least 2 h. The increase in Iscwas fully reversed by amiloride and glibenclamide. The increase in RTEwas not prevented by ouabain, suggesting that trypsin decreased paracellular conductance. Apical trypsin also induced a transient increase in intracellular Ca2+in human airway cells; treatment of these cells with BAPTA-AM mitigated the trypsin-induced increases of intracellular Ca2+and of Iscand RTE. Increasing intracellular Ca2+in airway cells with either ionomycin or thapsigargin reproduced the increase in Isc, whereas inhibitors of phospholipase C (PLC) prevented the increases in both Ca2+and Isc. These data indicate trypsin-like proteases and elastase, either present in lung cells or released by inflammatory cells into the alveolar space, play an important role in the clearance of alveolar fluid by increasing ion transport and paracellular resistance via a PLC-initiated rise of intracellular Ca2+.
Variable overoxidation of peroxiredoxins in human lung cells in severe oxidative stress
Authors: Lehtonen Siri T. , Markkanen Piia M. H. , Peltoniemi Mirva , Kang Sang Won , Kinnula Vuokko L.
Published: December 2004

Peroxiredoxins (Prxs) are a group of thiol containing proteins that participate both in signal transduction and in the breakdown of hydrogen peroxide (H2O2) during oxidative stress. Six distinct Prxs have been characterized in human cells (Prxs I–VI). Prxs I–IV form dimers held together by disulfide bonds, Prx V forms intramolecular bond, but the mechanism of Prx VI, so-called 1-Cys Prx, is still unclear. Here we describe the regulation of all six Prxs in cultured human lung A549 and BEAS-2B cells. The cells were exposed to variable concentrations of H2O2, menadione, tumor necrosis factor-α or transforming growth factor-β. To evoke glutathione depletion, the cells were furthermore treated with buthionine sulfoximine. Only high concentrations (300 μM) of H2O2caused a minor increase (<28%, 4 h) in the expression of Prxs I, IV, and VI. Severe oxidant stress (250–500 μM H2O2) caused a significant increase in the proportion of the monomeric forms of Prxs I–IV; this was reversible at lower H2O2concentrations (≤250 μM). This recovery of Prx overoxidation differed among the various Prxs; Prx I was recovered within 24 h, but recovery required 48 h for Prx III. Overall, Prxs are not significantly modulated by mild oxidant stress or cytokines, but there is variable, though reversible, overoxidation in these proteins during severe oxidant exposure.
Redirected primary T cells harboring a chimeric receptor require costimulation for their antigen-specific activation
Authors: Friedmann-Morvinski Dinorah , Bendavid Alain , Waks Tova , Schindler Daniel , Eshhar Zelig
Published: December 2004

Chimeric receptor (CR)–redirected lymphocytes (T bodies) have great potential in the eradication of tumor cells. To extend this approach to target cells that do not express surface ligands to costimulatory receptors (eg, cancer cells), we have generated an antibody-based tripartite chimeric receptor (TPCR) that contains scFv linked to the costimulatory molecule, CD28 without its ligand-binding domain, and to the cytoplasmic moiety of the FcRγ subunit. In this study, we tested the ability of 2,4,6-trinitrophenyl (TNP)–specific TPCR to drive primary, naïve T cells derived from CR-transgenic (Tg) mice to undergo full activation. As a control, we used Tg mice expressing a similar transgene but lacking the signaling region of CD28 (Tg-TPCRΔCD28). Only T cells from the TPCR-Tg and not the CD28-truncated TPCR-Tg mice could undergo activation following stimulation on hapten-modified target cells not expressing B7. Moreover, when stimulated with TNP protein displayed on plastic, the TPCR-Tg T cells expressing the entire TPCR gene became fully activated for proliferation, interleukin 2 production, protection from apoptosis, and killing of TNP-modified target cells. Finally, TPCR-Tg mice manifested a delayed-type hypersensitivity response following skin challenge in the absence of priming. Taken together, our results suggest that the TPCR is the receptor configuration of choice for clinical applications using primary T or stem cells.
The promyelocytic leukemia protein PML regulates c-Jun function in response to DNA damage
Authors: Salomoni Paolo , Bernardi Rosa , Bergmann Stephan , Changou Austin , Tuttle Sara , Pandolfi Pier Paolo
Published: December 2004

The promyelocytic leukemia (PML) gene, a tumor suppressor inactivated in acute promyelocytic leukemia (APL), regulates apoptosis induced by DNA damage. However, the molecular mechanisms by which PML modulates apoptosis following genotoxic stress are only partially elucidated. PML is essential for p53-dependent induction of programmed cell death upon γ-irradiation through PML-nuclear body (NB)–mediated control of p53 acetylation. Here, we show that PML selectively regulates proapoptotic transcription factors upon different types of DNA damage. We find that Pml inactivation protects fibroblasts from UV-induced apoptosis in a p53-independent manner. We demonstrate that c-Jun is required for UV-induced apoptosis and that PML is essential for both c-Jun transcriptional activation and DNA binding upon UV radiation. We find that PML physically interacts with c-Jun and that upon UV radiation the PML-NBs reorganize into novel nuclear microspeckled structures (UV-NBs), where PML and c-Jun dynamically accumulate. These data identify a novel PML-dependent pathway for c-Jun transcriptional activation and induction of apoptosis in response to DNA damage and shed new light on the role of PML in tumor suppression.
Endothelial barrier protection by activated protein C through PAR1-dependent sphingosine 1–phosphate receptor-1 crossactivation
Authors: Feistritzer Clemens , Riewald Matthias
Published: December 2004

Endothelial cells normally form a dynamically regulated barrier at the blood-tissue interface, and breakdown of this barrier is a key pathogenic factor in inflammatory disorders such as sepsis. Pro-inflammatory signaling by the blood coagulation protease thrombin through protease activated receptor-1 (PAR1) can disrupt endothelial barrier integrity, whereas the bioactive lipid sphingosine 1-phosphate (S1P) recently has been demonstrated to have potent barrier protective effects. Activated protein C (APC) inhibits thrombin generation and has potent anti-inflammatory effects. Here, we show that APC enhanced endothelial barrier integrity in a dual-chamber system dependent on binding to endothelial protein C receptor, activation of PAR1, and activity of cellular sphingosine kinase. Small interfering RNA that targets sphingosine kinase-1 or S1P receptor-1 blocked this protective signaling by APC. Incubation of cells with PAR1 agonist peptide or low concentrations of thrombin (∼ 40 pM) had a similar barrier-enhancing effect. These results demonstrate that PAR1 activation on endothelial cells can have opposite biologic effects, reveal a role for cross-communication between the prototypical barrier-protective S1P and barrier-disruptive PAR1 pathway, and suggest that S1P receptor-1 mediates protective effects of APC in systemic inflammation.
A rapid translocation of CD45RO but not CD45RA to lipid rafts in IL-6-induced proliferation in myeloma
Authors: Li Fu-Jun , Tsuyama Naohiro , Ishikawa Hideaki , Obata Masanori , Abroun Saeid , Liu Shangqin , Otsuyama Ken-ichiro , Zheng Xu , Ma Zi , Maki Yasuko , Kawano Michio M.
Published: December 2004

CD45, a receptor-type tyrosine phosphatase, is required for interleukin-6 (IL-6)-induced proliferation in human myeloma cells, which express the shortest isoform, CD45RO, but not the longest isoform, CD45RA. Here, we showed that IL-6 induced the translocation of CD45 to lipid rafts in an isoform-dependent manner. In myeloma cells, CD45RO was translocated to lipid rafts more rapidly than CD45RB, but exogenously expressed CD45RA was not translocated. When an IL-6Rα-transfected B-cell line was stimulated with IL-6, CD45RA was not translocated, although CD45RB was. We further confirmed that the translocated CD45 bound to IL-6Rα, Lyn, and flotillin-2, and this was followed by the dephosphorylation of the negative regulatory Tyr507 of Lyn. CD45 also bound to phosphoprotein associated with glycosphingolipid-enriched microdomains (PAGs), which were subsequently dephosphorylated, resulting in the release of C-terminal src kinase (Csk) from lipid rafts. Therefore, these results indicate that a rapid translocation of CD45RO to lipid rafts may be responsible for IL-6-induced proliferation, and that the change from CD45RA to CD45RO confers the ability to respond to IL-6 in human myeloma cells. (Blood. 2005;105:3295-3302)
Zukünftige Fahrzeugführungsassistenz – Kombinierte Längs- und Querregelung (Future Vehicle Guidance Assistance – Combined Longitudinal and Lateral Control)
Authors: Weilkes Michael , Bürkle Lutz , Rentschler Tobias , Scherl Michael
Published: December 2004

Die Erweiterung der vom ACC bekannten Längsführungsunterstützung bis hin zum Stillstand unter Einbeziehung einer Querführungsunterstützung bringt nicht nur Vorteile für die Fahrerentlastung, sondern kann durch die Vernetzung der Unterstützungszweige auch die Einzelfunktionalität verbessern bzw. transparenter machen. Zwei mögliche Stufen einer Kombination, die unterschiedliche Automatisierung im niedrigen Geschwindigkeitsbereich bieten, werden dargestellt. Für die Querführung wird ein Grundkonzept, das sowohl die autonome wie eine durch Führungsmomente unterstützende Querführung ermöglicht, dargestellt und zwei verschiedene Querregelungsansätze verglichen.
The effects of organolead compounds on a freshwater and a marine alga
Authors: Jarvie A W P , Marshall S J
Published: January 2005

There are conflicting reports concerning the toxicity of tetraalkyllead (TAL) compounds to algae. A number of groups have found the TAL's to be comparable in toxicity with the trialkyllead compounds (R3Pb+), whereas in a recent report it is suggested that the TAL's themselves are completely non‐toxic and any apparent toxicity is due to R3Pb+ breakdown products.

With the object of identifying the toxic agent, the effect of Et4Pb (TEL) on two algal species was re‐examined. Analyses were carried out during the course of the incubations to establish the nature and concentrations of organoleads present in both media and algae, and hence evaluate their relative contributions to total toxicity.

Algae were also cultured in the presence of Me4Pb (TML), Me3PbCl, Et3PbCl, Bu3PbCl and Et2PbCl2 to assess relationships between alkyl chain length and degree of substitution around the lead on algal activity. Additions of selenide and sulphide were made to the Et3Pb+ and Et2Pb2+ systems to see if these environmentally abundant species reduced or enhanced organolead toxicity. Problems were encountered in the analysis of the heterogeneous TEL containing media. Regardless of the analytical problems, the results confirm the previous findings that TAL's are non‐toxic to algae and it is the R3Pb+ breakdown products which are responsible for the apparent toxicity of the TAL's. The trialkylleads were the most toxic of the several alkyllead species studied, and within the trialkyl series toxicity increased with alkyl chain length. Neither selenide or sulphide had any significant ameliorative effect on alkyllead toxicity. It was found that the ionic organoleads were complexed on the TAL's and this complexing led to a number of unexpected results.
Polymeric cofactors which accelerate homogeneous rhodium(I) and ruthenium(II) catalyzed hydrogenations of alkenes
Authors: Bergbreiter David E , Bursten Marian S , Parsons Gregory L , Cook Kaelyn
Published: January 2005

Polymeric reagents prepared by exchanging silver(I) for H+ on a macroreticular polystyrene sulfonate ion exchange resin are shown to be capable of selectively absorbing triphenylphosphine from solutions of triphenylphosphine complexes of rhodium(I) and ruthenium(II). Absorption of triphenylphosphine during alkene hydrogenations catalyzed by RhCl(PPh3)3, RuCl2(PPh3)3 and RuHCl(PPh3)3 led to increased hydrogenation rates in hydrogenation of 1‐hexene and other alkenes. Addition of this silver(I) polystyrene sulfonate to alkene hydrogenations catalyzed by HRh(CO) (PPh3)3, RuH2(PPh3)3 and RuH(OCOCH3) (PPh3)3 also led to modest rate accelerations. Catalyst activations seen in these alkene hydrogenations were shown to be due in some cases to triphenylphosphine absorption. In other cases, HCl or HCl plus triphenylphosphine absorption was responsible for the formation of a more active catalyst solution.
Organotin biocides. X. Synthesis, structure and biocidal activity of organotin derivatives of 2‐mercaptobenzothiazole, 2‐mercaptobenzoxazole and 2‐mercaptobenzimidazole
Authors: Molloy K C , Purcell T G , Cunningham D , McCardle P , Higgins T
Published: January 2005

Ten organotin derivatives of 2‐mercaptobenzothiazole (Hmbt), 2‐mercaptobenzoxazole (Hmbo) and 2‐mercaptobenzimidazole (Hmbi) have been synthesised and thier structures characterised by spectroscopic methods. Triorganotin derivatives are all S‐bonded to the ligand and four‐coordinate at tin except Bu3Sn(mbo) which is five‐coordinate trans‐ONSnR3 polymer at 78K. The crystal structure of Cy3Sn(mbt) has been determined and confirms the tetrahedral geometry at tin. Bu2Sn(mbt)2 is weakly six‐coordinate by N,S chelating ligands. Biocidal activity patterns are presented for Cy3Sn(mbt), Ph3Sn(mbt) and Ph3Sn(mbo).
Crystal and molecular structure of [i‐Pr2Si]4 and [(Me3SICH2)2Si]4 and some structural properties of cyclopolysilanes, [R1R2Si]n (n = 3‐6)
Authors: Watanabe Hamao , Kato Motohiko , Okawa Tadashi , Kougo Yuichi , Nagai Yoichiro , Goto Midori
Published: January 2005

The crystal structures of octaisopropylcyclotetrasilane [i‐Pr2Si]4 (1) and octakis(trimethylsilylmethyl)cyclotetrasilane [(Me3SiCH2)2Si]4 (2) have been determined by means of X‐ray diffraction analysis. Various crystallographic and structural data for the two compounds were recorded. The Si4 rings of the compounds are nonplanar with quite large dihedral angles of 37.1° in (1) and 36.6° in (2), being comparable to that (36.8)° for [t‐BuMeSi]4 reported previously and other characteristic features in the structures of (1) and (2) were described. Some structural properties of the cyclic catenation systems, [R1R2Si]n (n = 3–6), including (1) and (2) were also discussed from a comparative viewpoint with respect to the ring shape and the relationship between ring size and Si‐Si bond length.
Identification of arsenobetaine and a tetramethylarsonium salt in the clam Meretrix lusoria
Authors: Shiomi Kazuo , Kakehashi Yukari , Yamanaka Hideaki , Kikuchi Takeaki
Published: January 2005

Chemical forms of arsenic were examined in six tissues (gill, mid‐gut gland, siphon, foot, mantle and adductor muscle) of the clam Meretrix lusoria. The gill was found to contain higher levels of arsenic than the other tissues. Regardless of the nature of the tissues, the presence of arsenobetaine was established by HPLC0ICP; it was a minor arsenic compound in gill but a major one in the other tissues. The major arsenic compound in gill, which was more cationic than arsenobetaine, was obtained in a relatively pure state by ion‐exchange chromatography, gel filtration and HPLC. It was positive to the Dragendorff reagent and iodine vapor but negative to ninhydrin reagent. Its 1HNMR spectrum exhibited only one signal at δ 1.7 (singlet) and its FAB mass spectrum gave a base peak at m/e 135 [(CH3)4As+] and two significant peaks at m/e 120 [(CH3)3As] and 106 [(CH3)2AsH]. These results suggested that the major arsenic compound in gill exists as a tetramethylarsonium salt (CH3)4As+ · X−. The tetramethylarsonium salt was also found as a minor component in the tissues other than the gill.
The direct synthesis of triorgano tin compounds
Authors: Holland F S
Published: January 2005

The synthesis of triorganotin halides directly from tin is described. The addition of an alkyl halide to tin metal dispersed in a molten quaternary halide rapidly and selectively produces the trialkyltin halide and a by‐product containing the quaternary as a tin halide complex. The quaternary halide, the tin, and the halide ion are all recovered from the by‐product by electrolysis and reused.
The distribution and potential toxic effects of TBT in UK estuaries during 1986
Authors: Waldock M J , Thain J E , Waite M E
Published: January 2005

The concentrations of butyltin compounds in seawater were measured at nine sites in the UK during 1986. In popular yachting centres concentrations of tributyltin (TBT) ranged from less than detectable ( < 1 ng dm−3) in the winter, up to 1500 ng dm−3 in marinas in the summer. Measurements of wastewater generated by high‐pressure hosing of yachts demonstrated that even higher environmental concentrations of TBT resulted from the procedure. The results of the monitoring programme are discssed in relation to the toxicity of TBT and recent government legislative actions.
Synthesis of tri‐n‐butyltin taurocholate, taurodeoxycholate and glycocholate
Authors: Sherman Larry R , Coyer Michael J , Huber Friedo
Published: January 2005

The bile acids, taurocholic, taurodeoxycholic and glycocholic acid, were reacted with bis(tri‐n‐butyltin) oxide (TBTO) to form 1:1 derivatives. The water of reaction was removed with 2, 2‐dimethoxypropane or by azeotropic distillation with benzene. The compounds were characterized by 13C and 119Sn NMR, IR, elemental analysis, molecular weight determination, DTA, TGA, and conductance measurements. The data indicated that tri‐n‐butyltin glycocholate forms a covalent ester, tin being tetracoordinated. The taurocholic and taurodeoxycholic acid derivatives contain one molecule of coordinated water. They partially dissociate in polar solvents. The taurocholic and glycocholic acid derivatives were tested in vitro as anticancer agents and exhibited ED50 in the 0.2–0.4 ppm (mg kg−1) range against KB epidermoid tumor and P‐388 leukemia using NCI protocols.
The reaction of hydrogen chloride with bis (p‐ethoxyphenyl)telluride, a possible route to pure tellurium
Authors: Elgy Christine , McWhinnie William R
Published: January 2005

The reaction of hydrogen chloride with bis(p‐ethoxyphenyl)telluride is investigated and shown to give essentially phenetole (C6H5COEt), tellurium, and bis(p‐ethoxyphenyl)tellurium dichloride. Spectroscopic methods (UV–visible, 125Te NMR) show that some bis(p‐ethoxyphenyl)ditelluride is produced. This is believed to arise from a side reaction of organic telluride with an intermediate organyltellurenyl chloride which is considered to arise from initial proton attack at the Te–C bond of the telluride. The ditelluride reacts with HCl to deposit 80% of its tellurium content as the element; phenetole is the other major product. Use of a spin‐trap reagent gave no evidence of radical intermediates.

An attempt to develop a reaction sequence to prepare high‐purity tellurium is described. Although a purity of 99.985% could be achieved, overall yields are not economic, unless very highpurity tellurium is required. The method described is, however, very effective for the removal of traces of tin, lead, arsenic and antimony and can significantly reduce the copper, iron and selenium content; for example, one treatment of an alloy (Te, 75%; Se, 25%) gave a sample of tellurium containing 40 ppm selenium.
Asymmetric hydrosilylation of prochiral ketones in the presence ofN‐benzyl‐N‐methylephedrinium halometallates
Authors: Rubina K I , Goldberg Yu Sh , Shymanska M V , Lukevics E
Published: January 2005

N‐benzyl‐N‐methylephedrinium hexachloroplatinate(IV), bromotrichlororhodate(III), and dibromodichlorozincate(II) have been synthesized by reacting (—)‐N‐benzyl‐N‐methylephedrinium bromide with K2PtCl6, RhCl3· 4H2O and ZnCl2, respectively. The above halometallates have been found to catalyse the asymmetric hydrosilylation of acetophenone and 3‐acetylpyridine with diphenylsilane. The hydrosilylation of 3‐acetylpyridine in the presence of (—)‐N‐benzyl‐N‐methylephedrinium zincate followed by silyl ether hydrolysis gives 1‐(3‐pyridyl)ethanol inca50% optical yield.
The selective introduction of organometallic markers into estrogens. A‐ring propargylation of β‐estradiol
Authors: Greenfield S , Gruselle M , Jaouen G , Varghese V , Nicholas K M
Published: January 2005

Introduction of the propargyl dicobalt hexacarbonyl moiety onto the estradiol A ring as a potential probe in receptor studies requires protection of the ring phenolic group, and the regio‐selectivity of the attack (2‐ versus 4‐position) depends on the bulkiness of the organometallic carbenium ion.
The direct synthesis of triorganotin compounds: Process and reaction mechanism
Authors: Holland Frank S
Published: January 2005

The reaction of tin metal with alkyl halides in the presence of a stoichiometric amount of halide ion rapidly produces very high yields of triorganotin halides. An overview of these reaction conditions and those required for the catalytic preparation of diorganotin dihalides shows that these preparations follow the normal reactivity of the alkyl halides towards nucleophiles. Both processes are satisfactorily explained by a mechanism involving tin halogenoanions as nucleophiles. A similar mechanism also explains the formation of organomagnesium and organozinc halides.
Synthesis of n,n′‐biquinolines by a coupling reaction of bromoquinolines using organonickel(0) complexes
Authors: Benito Yolanda , Canoira Laureano , Rodriguez J. Gonzalo
Published: January 2005

Tris(triphenylphosphine)nickel(0) (A) and a zerovalent pyridine–nickel complex (B) have been used as reagents for the coupling reaction of 3‐, 6‐ and 8‐bromoquinolines: 3,3′‐, 6‐6′‐ and 8,8′‐ Biquinolines were obtained in quantitative yields when A was used as the coupling reagent. B gave always a mixture of the n,n′ ‐biquinoline and substitution products. A mechanism can be outlined to explain the coupling reaction of bromoquinolines using zerovalent nickel complexes.
The photo‐oxidation of solutions of arsenicals to arsenate: A convenient analytical procedure
Authors: Cullen William R , Dodd Matthew
Published: January 2005

The separation of arylarsonic acids by HPLC on a reverse‐phase C18 column is described. Solutions containing these arsenicals and others such as arsenobetaine are photo‐oxidized to arsenate by ultraviolet (UV) radiation (1200 W, 1 h exposure). This allows the analysis of the solution for arsenic by hydride generation techniques. The method, UV HGAA, is developed and applied to the determination of arsenic in the methanol extracts of the Manila clam (Verupis japonica) and the Horse clam (Schizothoerus nutalli).
An iron–organic polymeric smoke suppressant for poly(vinyl chloride)
Authors: Neuse Eberhard W , Woodhouse Jeremy R , Montaudo Giorgio , Puglisi Concetto
Published: January 2005

The incorporation of a poly[ferrocene‐1, 2 (1, 3: 1, 1′)diylmethylene] fraction with M̄n=2100 as a smoke suppressant additive into both unplasticized and di(2‐ethylhexyl)phthalate‐plasticized, calcium carbonate‐filled poly(vinyl chloride) (PVC) compositions entails appreciable reductions in smoke evolution during combustion tests relative to unmodified formulations. Best results, with smoke density reductions in the range 25‐80%, are obtained at the 3% loading level, with higher additive concentrations causing no further improvements. The findings of this study may have implications on the design of other polymeric engineering materials exposed to potential fire hazards.
A simplified procedure for the determination of butyltin species in water
Authors: Chapman A H , Samuel A
Published: January 2005

A method is described for the analysis of solutions containing inorganic tin and butyltin compounds. It can be used to determine total tin at a concentration of 20 ng dm−3 using a 5 dm3 sample. The method is based on solvent extraction with dichloromethane containing tropolone and determination of the tin as inorganic tin by atomic absorption spectroscopy using electrothermal atomization. The extracted butyltin compounds can be separated by paper chromatography and the tin content of the individual spot determined as above. Observations on the stability of butyltin compounds in water at the ∼2 mg dm−3 (Sn) are included.
Methylation of inorganic lead by Tamar Estuary (UK) sediments
Authors: Walton A P , Ebdon L , Millward G E
Published: January 2005

Tetramethyllead (TML) has been produced from inorganic lead salts using biologically active sediments and waters from the Tamar Estuary, S. W. England. The TML production was a two‐stage process involving an initial lag phase of about 100 hours followed by the exponential appearance of TML, which amounted to about 0.03% of total added lead. The methylation process is discussed in the context of lead transport in estuaries.
Hydrophilic tetrachloroferrate(III) salts of ferricenyl‐substituted carboxylic acids
Authors: W Neuse Eberhard , B D Khan Fathima , Meirim Maria G.
Published: January 2005

As part of a project to provide hydrophilic ferricenium compounds for biomedical investigations, several ferrocenyl‐alkanoic and ‐alkanedioic acids, including ferrocenylacetic, β‐ferrocenylpropionic and γ‐ferrocenylbutyric acids, ferrocylmalonic acid, and the two thioether derivatives, S‐ferrocyl‐ β‐mercaptopropionic acid and S‐ferrocylthiomalic acid, are chemically oxidized to the respective ferricenium salts. While oxidation with the nitromethane/tetrafluoroboroboric acid system affords poorly crystallizing tetrafluoroborate salts, for the most part possessing unsatisfactory solubility characteristics, more hydrophilic salts containing the tetrachloroferrate(III) (FeCl) counterion, albeit contaminated with FeCl2, are obtained by treatment of the substrate acids with excess iron(III) chloride. The most promising method of ferricenium generation investigated in this study involves oxidation by means of the p‐benzoquinone‐HCL‐FeCl3 system, which directly provides the respective ferricenium tetrachloroferrate salts. The IR and Mössbauer spectra confirm the expected ferricenium structures. The method appears attractive enough to be utilized in future investigations involving more complex notably polymeric, derivatives of the ferrocene parent compound.
Effects of trialkyllead compounds on mitochondrial energy conservation
Authors: Griffiths D E , Connerton I
Published: January 2005

The effects of triethyllead acetate and tri‐n‐butyllead acetate on rat liver mitochondrial ATPase, succinate‐driven ATP synthase and mitochondrial membrane potential have been compared with those of the equivalent organotin compounds. ATP synthase I50 values were approximately four times the ATPase I50 values for organotin compounds but the reverse pattern of activity is observed with trialkyllead compounds, which are 5‐10 times more effective inhibitors of ATP synthase than of ATPase activity. The primary effects of trialkyltins are as inhibitors of the ATPase complex with relatively minor effects on mitochondrial membrane potential ($PS). In contrast, trialkylleads are potent uncoupling agents, which accounts for their potent inhibition of ATP synthesis. The uncoupling action of trialkylleads and trialkyltins is independent of chloride concentration and is unlikely to be due to Cl−/OH− exchange.
Uptake of mercury by caged crayfish
Authors: Parkst J W , Sutton J A , Hollinger J D , Russell D D
Published: January 2005

An in situ caged crayfish experiment was conducted in the Wabigoon River System, Ontario, Canada to determine the relative importance of food and water pathways for mercury accumulation in crayfish. Two groups of 160 crayfish were suspended in the water column; one at an ucontaminated site, the other at a location with highly elevated total mercury and methylmercury levels in water. Crayfish at each site were divided into two groups. Crayfish were fed either sucker flesh obtained from an uncontaminated lake (low mercury diet) or walleye flesh from contaminated Clay Lake, Ontario, Canada (high mercury diet). After 10 weeks crayfish at both sites fed the high mercury diet had over 20 times mercury accumulation compared to crayfish on the low mercury diet. There was no statistical effects due to sharply elevated water concentrations of total and methylmercury on mercury bodyburdens. This indicated that food was the dominant pathway for mercury accumulation in crayfish.
An investigation of the efficacy of organotin compounds for the control of the cotton stainer, Dysdercus cingulatus, the mosquito,Anophelese stephensi, and the common house fly, Musca domestica
Authors: Saxena Prabhu N , Crowe Alan J
Published: January 2005

A series of commercial organotin compounds was screened for efficacy against the three insect species Dysdercus cingulatus (cotton stainer), Anophelese stephensi (mosquito) and Musca domestica (house fly). Tributyltin species in the general order Bu3SnCl>(Bu3Sn)2O>Bu3Sn(linoleate) were more effective than two triphenyltin compounds. Tricyclohexyltin hydroxide, dimethyltin chloride, phenyltin trichloride and a diethyltin dichloridephenanthroline adduct were less effective.
Polymer‐supported ferrocene derivatives. Some 13C CP MAS NMR studies and use as hydrogenation catalysts
Authors: Butler Ian R , Cullen William R , Han Nam Fong , Herring F Geoffrey , Jagannathan N R , Ni Jijin
Published: January 2005

Polystyrene derivatives react with the lithioferrocenes Fe(η5‐C5H4Li)(η5C5H5),Fe(η5‐C5H5),Fe(η5‐C5H4Li)2,Fe[η5‐C5H3(CHMeNMe2)Li‐1,2] [η5‐C5H5], and with lithium ferrocenylphosphines, to yield ironcontaining materials. The Mössbauer spectra confirm the loading of unstrained ferrocene fragments, some oxidized, in all cases. The 13C CP MAS NMR spectra also show the loading but the resolution (structural information) is not as good as can be obtained on model solid samples. Palladium(II) derivatives of the amine‐ and phosphine‐containg materials are active hydrogenation catalysts for olefins. Double‐bond migration also occurs in the case of 1‐hexene.
Methylation of arsenic trioxide in hamsters with liver damage induced by long‐term administration of carbon tetrachloride
Authors: Takahashi Keiko , Yamauchi Hiroshi , Yamato Naohisa , Yamamura Yukio
Published: January 2005

One‐time oral administration of arsenic trioxide to hamsters with toxic liver cirrhosis induced by longterm exposure to carbon tetrachloride resulted in significant elevations of the concentrations of dimethylarsenic species in the liver and in blood, and in high urinary excretions of dimethylarsenic species. These concentration changes in the liver, blood and urine indicated that the methylation of inorganic arsenic was not inhibited but promoted in hamsters suffering from experimentally induced toxic liver cirrhosis. Cirrhotic hamsters also had increased urinary excretion of inorganic arsenic. Results of the determinations of S‐adenosylmethionine in the livers suggested that this compound may accelerate the methylation of inorganic arsenic in the cirrhotic liver.
Determination of inorganic arsenic and organic arsenic compounds in marine organisms by hydride generation/cold trap/gas chromatography— mass spectrometry
Authors: Kaise Toshikazu , Yamauchi Hiroshi , Hirayama Teruhisa , Fukui Shozo
Published: January 2005

The behavior of arsenite, methylarsonic acid, dimethylarsinic acid, trimethylarsine oxide, dimethyl‐R‐arsine oxides, and trimethyl‐R‐arsonium compounds (R = carboxymethyl, 2‐carboxyethyl, 2‐hydroxyethyl) toward sodium borohydride and hot aqueous sodium hydroxide was investigated. The arsines obtained by sodium borohydride reduction of the undigested and digested solutions were collected in a liquid‐nitrogen cooled trap, separated with a gas chromatograph, and detected with a mass spectrometer in the selected‐ion‐monitoring mode. The investigated arsenic compounds were stable in hot 2 mol dm−3 sodium hydroxide except arsenobetaine [trimethyl(carboxymethyl)arsonium zwitterion] that was converted to trimethylarsine oxide, and dimethyl(ribosyl)arsine oxides that were decomposed to dimethylarsinic acid. Hydride generation before and after digestion of extracts from marine organisms allowed inorganic arsenic, methylated arsenic, arsenobetaine, and ribosyl arsenic compounds to be identified and quantified. This method was applied to extracts from shellfish, fish, crustaceans, and seaweeds.
Environmental factors relating to arsenic accumulation by Dunaliella sp
Authors: Yamaoka Yukiho , Takimura Osamu , Fuse Hiroyuki
Published: January 2005

The accumulation of arsenic by Dunaliella sp. was examined by using a solution containing arsenic only as a first approach to the study of arsenic recovery by aqueous systems. The accumulation of arsenic by Dunaliella sp. was rapid, with equilibrium established in 8 h with respect to arsenic partioning between dissolved and particulate phase. The optimum accumulation was at pH 8.2, NaCl 20 g dm−3, illumination 5000–10000 lux and temperature 22°C. Increased phosphate concentration significantly decreased the uptake of arsenic in the culture. These results suggested that accumulation of arsenic by Dunaliella sp. depended upon biological activity.
Lipophilic arsenic compound(s) in the liver of a tiger shark (Galeocerdo cuvier)
Authors: Miyajima Mariko , Hamada Noriaki , Yoshimura Etsuro , Okubo Akira , Yamazaki Sunao , Toda Shozo
Published: January 2005

Homogenized aliquots (100 g) of the liver (8.4 kg, 5 m̈g As g−1) of a tiger shark (Galeocerdo cuvier) were extracted with chloroform/methanol, and the extracts purified by countercurrent extraction (hexane/87% ethanol), silica gel column chromatography (chloroform/methanol mixtures as mobile phases), and silica gel thin‐layer chromatography (chloroform/methanol/acetic acid). The purified samples (24 mg arsenic g−1) gave no 31P NMR signal, but gave 1H and 13C NMR signals with similarities to those of dipalmitoylphosphatidic acid and salad on and also signals indicative of the presence of methylated arsenic compounds. The sample could contain a diacyl glyceride with a methylated arsenic group.
Utilization of inorganic and organic arsenic compounds in new technologies
Authors: Oikawa Kikuo
Published: January 2005

This paper reviews the use of arsenic compounds in semiconductor manufacture and emphasizes the role of alkylated arsenic compounds.
Application of arsenic to electrophotoreceptors
Authors: Kina Hideki , Iijima Toshiyuki , Nakaura Yasuo
Published: January 2005

Arsenic has been applied to many electronic devices such as electrophotoreceptors, gallium arsenide (GaAs) semiconductors and solid‐state image pickup devices. For electrophotoreceptors selenium–arsenic (SeAs) alloys are coated onto the conductive substrate of the receptors. Arsenic is mostly used in electophotoreceptors in electronic devices.

During the coating process, a part of the gaseous arsenic is released through an exhaust system. In order to avoid arsenic being discharged to the atmosphere, bag filters and high‐efficiency particulate air filters are set before the exhaust port. Any arsenic which still exists in the waste water after washing tools and jigs from the coating process is collected by sedimentation before discharging.

The Ames salmonella/microsome plate test for As2Se3 indicated no mutagenic activity under the test system used. For the safety of workers engaged in arsenic‐related jobs, they received a medical examination once every six months. No negative trends from the examination was found in 428 men who received the examination from Autumn 1980 to Spring 1987.
The influence of extended conjugation on electroactive properties of copper phthalocyanine macromolecules
Authors: Nalwa Hari S
Published: January 2005

A monomer and polymer of a copper(II) phthalocyanine have been synthesized in order to develop structure‐property relationships. Various electroactive properties such as dielectric constant, resistivity and thermally stimulated depolarization effects were investigated in order to examine the influence of extended conjugation.
Thermal properties of some di(4‐substituted phenyl)tin dichloride complexes with nitrogen donor ligands
Authors: Biddle B N , Gray J S , Ormiston G P
Published: January 2005

The thermal properties of some organotin complexes of general structure (4‐ZC6H4)2SnCl2.L2 (Z=Me, CF3, F, Cl, OMe and H; L2 = 2,2′ ‐bipyridyl and 4,4′ ‐dimethyl‐2,2′ ‐bipyridyl) are reported. The thermal data obtained by Differential Thermal Analysis (DTA) for these complexes is reported. Thermal decomposition experiments for some of the complexes are described and indicate a disproportionation of the complexes into the aryltin trichloride complex and the triaryltin chloride. The controlled decomposition provides a possible alternative preparative route to some aryltin trichloride complexes.
Cluster chemistry. 61. Addition of HX (XCl, Br,I) or AuCl(PPh3) to an open Ru5 cluster. X‐ray structures of Ru5(μ‐H)(μ5‐C2PPh2)(μ‐PPh2)(μ‐Br)(CO)13 and Ru5(μ‐H)(μ5‐C2PPh2)(μ3‐I)(μ‐PPh2)(CO)12
Authors: Bruce Michael I , Liddell Michael J , Nicholson Brian K
Published: January 2005

Reactions of aqueous HX (XCl, Br) or of AuCl(PPh3) with Ru5(μ5‐C2PPh2)(μ‐PPh2)(CO)13 result in addition of the 4e‐donor set (H + X) or (Au(PPh3) + Cl) with concomitant opening of two RuRu bonds to give complexes containing dimetallated triangular of ‘scorpion’ cores. Aqueous HI reacts similarly, but in this case the iodide ligand spans three Ru atoms, the (H + I) set acting as 6e‐donor. The structures of the two title compounds were confirmed by X‐ray crystallographic studies. Ru5(μ‐H)(μ5‐C2PPh2)(μ‐PPh2)‐(μ‐Br)(CO)13 is triclinic, space group P1, a = 9.689(2), b = 11.874(2), c = 20.005(4) Å, α = 84.66(2), β = 82.90(6), λ = 67.51(6)°, Z = 2; 6478 data with I > 2σ(I) were refined to R = 0.0368, Rw = 0.0362. Ru5(μ‐H)(μ5‐C2PPh2)(μ3‐I)(μ‐PPh2)‐(CO)12.CH2Cl2 is monoclinic, space group P21/n, a = 14.809(4), b = 20.721(4), c = 17.698(5) Å, β = 111.42(2)°, Z = 4; 7815 data with I > 2σ(I) were refined to R = 0.0440, Rw = 0.0416.
Thermal stability and the formation of conducting materials from tricobalt–carbyne clusters
Authors: Worth Gillian H , Robinson Brian H , Simpson Jim
Published: January 2005

The conductivity of microcrystalline mono‐ or biscarbyne capped tricobalt clusters and a preliminary study of the physical properties of the thermally decomposed materials are presented. Solid materials with high conductivites are produced by the controlled decomposition of the non‐ conducting carbonyl clusters in which there are two cluster units or an alkyne/cluster system. Processes leading to conducting solids were studied by thermogravimetric, mass spectral, DRIFT and SEM techniques. Bi‐capped clusters are thermally stable insulators but it is suggested that doped materials will show increased conductivity.
CH and NH bond activation in reactions of vinyl acetate, allyl cyanide, allylamine and other amines with (η‐C5H5)2Rh2(CO)(CF3C2CF3)
Authors: Dickson Ron S , Jenkins Susan M
Published: January 2005

There is activation of olefinic CH bonds when (η‐C5H5)2Rh2(CO)(CF3C2CF3) is treated with vinyl acetate or allyl cyanide. These reactions are initiated by exposure to sunlight. In the vinyl acetate reaction, each of the three vinylic CH bonds can be broken, but there is strong preference for cleavage at the substituted carbon. The products formed in these reactions are bisalkenyl complexes of the type (η‐C5H5)2Rh2{μ‐C(CF3)C(CF3)H}(μ‐CRCR′R″), and all isomers have been thoroughly characterized by NMR analysis. Similar reactions with allylamine and other amines (NH2R, NHMe2) occur in the dark and proceed by NH bond cleavage. Near‐quantitative amounts of the products, (η‐C5H5)Rh2{C(CF3)C(CF3)H}(C(O)NRR′) are isolated. Spectroscopic data indicate a bridging carboxamide ligand attached to the RhRh bond from oxygen and nitrogen donor sites. It is proposed that coordination of O or N to rhodium has a strong influence on all of the reactions studied.
Orthomanganated arenes in synthesis VII. Transition‐metal mediated formation of a PP bond; the X‐ray crystal structure of Mn2(μ‐η1, η1‐Ph2PPPh2)(μ‐Cl)2(CO)6
Authors: Arnold Leslie J , Main Lyndsay , Nicholson Brian K.
Published: January 2005

The reaction of PPh2Cl with orthomanganated acetophenone, 2′‐CH3C(O)C6H4Mn(CO)4, gives Mn2(μ‐η1,η1‐Ph2PPPh2)(μ‐Cl)2(CO)6. An X‐ray structure determination [triclinic, space group P1, a = 10.908(4) Å, b = 11.756(3) Å, c = 12.186(3) Å, α = 96.20(2)°, β = 99.51(2)°, γ = 96.52(2)°] shows two Mn(CO)3 groups held together by two bridging Cl ligands, and further bridged by a Ph2PPPh2 group prepared in situ.
The X‐ray structure of Os(CS)(PhCCPh)(PPh3)2, a complex containing a four‐electron donor acetylene ligand
Authors: Burrell A K , Elliott G P , Rickard C E F , Roper W R
Published: January 2005

Os(CS)(PhCCPh)(PPh3)2 is formed by the treatment of Os(CS)(CO)(PPh3)3 with diphenylacetylene and is an example of a complex containing a four‐electron donor acetylene ligand. Os(CS)(PhCCPh)(PPh3)2 crystallizes in the monoclinic space group P21/n with the cell dimensions a = 9.028(5), b = 25.256(2) and c = 19.22(2) Å with β = 103.8(7)°, V = 4260 Å3, Z = 4 and d(calcd) = 1.461 g cm−3 for mol.wt 937.09 g mol−1. Diffraction data were collected with a Nonius CAD‐4 diffractometer and refined to R = 4.05% and Rw = 4.19% for 1172 independent reflections. The structure can be described as a distorted trigonal bipyramid with the CS ligand occupying an axial position. The two cis‐PPh3 ligands are in equatorial sites with the acetylene occupying a position between the remaining axial and equatorial sites. The diphenylacetylene is symmetrically bound to the metal with an average OsC distance of 2.04(3) Å. The OsCS distance is unusually short at 1.79(2) Å.
Infrared and Raman spectra of (η6‐mesitylene)M(CO)3 complexes (MCr, Mo or W): An insight into metal–arene bonding
Authors: Armstrong R S , Aroney M J , Barnes C M , Nugent K W
Published: January 2005

Infrared and Raman spectra of mesitylene complexes of chromium, molybdenum and tungsten tricarbonyls have been studied. Bands have been assigned and intesities calculated for a number of important modes. The intensities are related to the polarities and polarizabilities of individual bonds within the molecules. Variations of bond properties with change of metal M in the (η6‐mesitylene)M(CO)3 complexes have been examined. The results are interpreted in terms of the relative importance of π‐donation from the arene to the metal and of δ‐backbonding. A molecular orbital scheme is proposed which accounts for the changes observed in the degree of π‐and δ‐bonding within the group of complexes studied.
The chemical form and acute toxicity of arsenic compounds in marine organisms
Authors: Kaise Toshikazu , Fukui Shozo
Published: January 2005

A method for the separation and identification of inorganic and methylated arsenic compounds in marine organisms was constructed by using a hydride generation/cold trap/gas chromatography mass spectrometry (HG/CT/GC MS) measurement system.

The chemical form of arsenic compounds in marine organisms was examined by the HG/CT/GC MS system after alkaline digestion. It was observed that trimethylarsenic compounds were distributed mainly in the water‐soluble fraction of muscle of carnivorous gastropods, crustaceans and fish. Also, dimethylated arsenic compounds were distributed in the water‐soluble fraction of Phaeophyceae. It is thought that most of the trimethylated arsenic is likely to be arsenobetaine since this compound released trimethylarsine by alkaline digestion and subsequent reduction with sodium borohydride.

The major arsenic compound isolated from the water‐soluble fraction in the muscle and liver of sharks was identified as arsenobetaine from IR, FAB Ms data, NMR spectra and TLC behaviour.

The acute toxicity of arsenobetaine was studied in male mice. The LD50 value was higher than 10 g kg−1. This compound was found in urine in the non‐metabolized form. No particular toxic symptoms were observed following administration. These results suggest that arsenobetaine has low toxicity and is not metabolized in mice. The LD50 values of other minor arsenicals in marine organisms, trimethylarsine oxide, arsenocholine and tetramethylarsonium salt, were also examined in mice.
Preparation and biocidal properties of mixed butyl/cyclohexyl trialkyltin carboxylates
Authors: Qing‐Lan Xie , Zhi‐Qiang Yang , Zu‐Xin Zhang , Dian‐Kun Zhang
Published: January 2005

Two series of trialkyltin carboxylates containing butyl and cyclohexyl groups on tin, BunCy3‐nSnO2CR (n = 1, 2; R = n‐Pr, Ph, 4‐CIC6H4, 4‐NO2C6H4) have been synthesized and their structures characterized by IR, and 119Sn and 13C NMR spectroscopies. The compounds are five‐coordinate, carboxylate‐bridged polymers when R = n‐Pr, while the other aromatic carboxylates are four coordinate. The compounds were also tested for their fungicidal, insecticidal and acaricidal activities.