bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavioral features of CHARGE syndrome (Hall–Hittner syndrome) comparison with Down syndrome, Prader–Willi syndrome, and Williams syndrome
Authors: Graham John M. , Rosner Beth , Dykens Elisabeth , Visootsak Jeannie
Published: January 2005

CHARGE syndrome, or Hall–Hitner syndrome (HHS), has been delineated as a common syndrome that includes coloboma, choanal atresia, cranial nerve dysfunction (particularly asymmetric facial palsy and neurogenic swallowing problems), characteristic ear abnormalities, deafness with hypoplasia of the cochlea and semicircular canals, genital hypoplasia, and variable heart defects, orofacial clefting, tracheo‐esophageal fistula, renal anomalies, thymic/parathyroid hypoplasia, spine anomalies, short broad neck with sloping shoulders, and characteristic facial features. We conducted behavioral and personality assessments in 14 boys with HHS syndrome aged 6–21 years, and compared their characteristics with similar data from 20 age‐matched boys with Down syndrome (DS), 17 boys with Prader–Willi syndrome (PWS), and 16 boys with Williams syndrome (WS). We used the Reiss Profile of Fundamental Goals and Motivation Sensitivities, the Achenbach Child Behavior Checklist (CBCL), and the Aberrant Behavior Checklist (ABC). All 14 boys with HHS were legally deaf, and 10 of the 14 were also legally blind. In comparison these other syndromes, boys with HHS had behavior that resembled autistic spectrum disorder. They were socially withdrawn, lacked interest in social contact, and manifested reduced seeking of attention from others, with hyperactivity and a need to maintain order. Though the boys with HHS showed decreased social interaction, they were not as socially impaired as in classic autism. Their language was delayed due to dual sensory impairment, cranial nerve deficits, and chronic medical problems, but their language style was not abnormal (no echolalia or jargon, no scripted phrases, and no pronoun reversal). Boys with HSS appeared frustrated, but they were not aggressive, or at risk for delinquency, manifesting few stereotypic behaviors or unusual preoccupations. They did not have a restricted repertoire of activities and interests. Their behavioral features appeared to be due to dual sensory impairment affecting hearing and vision, rather than to primary autistic spectrum disorder, but successful remediation requires similar educational interventions, which are discussed herein. © 2005 Wiley‐Liss, Inc.
An epidemiological analysis of CHARGE syndrome: Preliminary results from a Canadian study
Authors: Issekutz Karina A. , Graham John M. , Prasad Chitra , Smith Isabel M. , Blake Kim D.
Published: January 2005

CHARGE syndrome is a well‐characterized clinical diagnosis with recent data supporting a genetic etiology. A 3‐year national surveillance coordinated by the Canadian Pediatric Surveillance Program (CPSP) was started in September 2001. Physicians notified the CPSP if they had cared for individuals with CHARGE syndrome within their practice, and then completed a detailed reporting form. To date, there are 77 confirmed cases of CHARGE syndrome. The highest provincial prevalence of CHARGE syndrome in Canada was estimated at 1 in 8,500 live births. Subgroups of cases with particular clusters of anomalies were identified. In older individuals, bilateral posterior choanal atresia (BPCA) was predictive of the presence of the three other major criteria and of aortic arch anomalies. Individuals with CHARGE syndrome who demonstrated a less extensive phenotype (≤3 major criteria) were more likely to present with minor cardiovascular malformations, including small atrial or ventricular septal defects (VSD) or patent ductus arteriosus (PDA). A significant cause of morbidity was severe feeding difficulty, including problems with chewing, swallowing, and gastroesophageal reflux, which were prevalent throughout childhood. Infant mortality is high in individuals with CHARGE syndrome. However, life expectancy has improved for those surviving their first year. Increased mortality was associated with distinct cardiovascular malformations or ventriculomegaly combined with brainstem or cerebellar anomalies. From this study, revised diagnostic criteria are proposed for infants, children, and adolescents to help identify a group of individuals who represent CHARGE syndrome with more of the classical features as apposed to the boarder association. © 2005 Wiley‐Liss, Inc.
Synthesis of the selective antimuscarinic agent 4‐{[cyclohexylhydroxy(2‐methoxyphenyl)silyl]‐methyl}‐1,1‐dimethylpiperazinium methyl sulfate (o‐methoxy‐sila‐hexocyclium methyl sulfate)
Authors: Tacke Reinhold , Rafeiner Klaus , Strohmann Carsten , Mutschler Ernst , Lambrecht Günter
Published: January 2005

The synthesis of the potent and highly selective silicon‐containing antimuscarinic agent o‐methoxysila‐hexocyclium methyl sulfate and its corresponding tertiary amine (isolated as the dihydrochloride) is described. The quarternary compound is an o‐methoxy derivative of sila‐hexocyclium methyl sulfate, which represents one of the tools currently used in experimental pharmacology for the subclassification of muscarinic receptors. The o‐methoxy derivative, the pharmacological profile of which differs substantially from that of the nonmethoxy compound, is also recommended as a tool for the investigation of muscarinic receptor heterogeneity.
The synthesis and the crystal and molecular structure of the fungicide bis(4‐fluorophenyl)‐methyl(1H‐1,2,4‐triazol‐1‐yl‐methyl)silane (flusilazole, DPX H 6573)
Authors: Tacke Reinhold , Becker Beate , Schomburg Dietmar
Published: January 2005

Detailed procedures (based on the respective patent literature) for the preparation of the broadspectrum fungicide flusilazole (DPX H 6573) on the laboratory scale are described using as the starting material dichloro(chloromethyl)methylsilane [CH3(ClCH2)SiCl2]. In addition, the crystal and molecular structure of flusilazole (determined by means of X‐ray diffraction analysis) is described.
Stability and microtox response of butenyltin compounds
Authors: Dooley Carol A , Testa John P
Published: January 2005

Tributenyltin bromides containing double bonds at carbon atoms C‐1, C‐2 or C‐3 were synthesized from symmetrical tetrabutenyltins. Although all three tetrabutenyltin compounds were stable, only the tributenyltin bromides with double bonds at C‐1 and C‐3 were sufficiently stable for further studies. In aqueous sodium bromide (NaBr) solution containing 1% acetone, tri‐1‐butenyltin bromide was more stable in sunlight than tri‐3‐butenyltin bromide, yet neither compound was as stable as tributyltin bromide. Stability in seawater, in the absence of ultraviolet (UV) light, was less for both tri‐1‐butenyltin bromide and tri‐3‐butenyltin bromide than for tributyltin bromide. The relative toxicities of the tributenyltin bromides were determined using a bioluminescent bacteria assay. The concentrations of tributenyltin bromides necessary to produce a toxic response were three to six times greater than for tributyltin bromide.
Synthesis and spectroscopic characterization of dimethylgermanium derivatives of dipeptides, crystal structure of dimethylgermanium glycylglycinate and in vivo effects of dimethylgermanium glycylglycinate against murine leukemia P388
Authors: Vornefeld Michael , Huber Friedo , Preut Hans , Brunner Henri
Published: January 2005

Dimethylgermanium derivatives of dipeptides, Me2GeAA (H2AA = H2glygly, H2glyala, H2glyval, H2glyleu, H2glymet) have been obtained by the reaction of Me2GeBr2 with H2AA in the presence of triethylamine. The crystal structure of Me2Geglygly has been determined by single‐crystal X‐ray diffraction. The dipeptide is tridentately coordinated to germanium, which has a distorted trigonal bipyramidal environment. From infrared and Raman data, analogous molecular structures are inferred for the other dimethylgermanium derivatives of dipeptides. 1H NMR measurements show that Me2Geglygly is completely hydrolyzed in aqueous solution to give H2glygly and (Me2Geo)x.

In vivo tests with Me2Geglygly showed no toxic or antitumor activity against murine leukemia P388.
Thermal decomposition of butylindium thiolates and preparation of indium sulfide powders
Authors: Nomura Ryoki , Inazawa Shin'ji , Kanaya Kouichi , Matsuda Haruo
Published: January 2005

Thermal properties of organoindium thiolates were investigated by means of thermogravimetric (TG) and differential thermal (DT) analysis. Dibutyl‐indium propylthiolates (Bun2InSPrn, Bun2InSPri, Bui2InSPrn and Bui2InSPri) decomposed up to 280°C along with an exothermic DT peak and gave indium(I) sulfide (InS) powders. Although the arylthiolate Bun2InSPh also afforded InS powders, it decomposed at a slightly higher temperature. In contrast, the dithiolate and the dithiocarbamate complexes [BunIn(SPri)2 and In (S2CNBu2)3] gave indium(III) sulfide (In2S3) powders.
The determination of tetra‐alkyllead and ionic alkyllead compounds in seafood
Authors: Forsyth D S , Iyengar J R
Published: January 2005

Extraction methodologies were developed for tetra‐alkyllead and ionic alkyllead compounds in seafood. Tetra‐alkylleads were extracted with n‐hexane after the samples had been enzymatically hydrolyzed. The ionic alkylleads were complexed with diphenylthiocarbazone (dithizone) at pH 8 and 9 from enzymatically hydrolyzed samples to optimize recovery. The dithizone extracts were butylated prior to analysis by gas chromatography–atomic absorption spectrometry (GC AA). Instrumental detection limits ranged between 1.6 and 2.3 pg lead. Application to a limited number of seafood samples indicated the possible presence of trace amounts (ca 1 ng g−1) of trimethyllead in some samples. No other alkylleads were detected.
Spindle‐inhibiting effects of organotin compounds. II. Induction of chromosomal supercontraction by di‐ and tri‐alkyl and ‐aryl compounds
Authors: Jensen Klaus Gjervig , Andersen Ole , Rønne Mogens
Published: January 2005

Spindle‐inhibiting effects of chemical compounds may be studied indirectly by quantitation of chromosomal contraction. The effects of the trimethyltin (TMT), dimethyltin (DMT), tributyltin (TBT), dibutyltin (DBT), triphenyltin (TPhT) and diphenyltin (DPht) moieties as the chloride on chromosomal contraction was studied by measurement of the average length of chromosome No. 1 from asynchronous cultures of human peripheral lymphocytes. TMT, TBT, TPhT and DPhT appear to be very strong inducers of chromosomal supercontraction, indicating that these compounds conceivably are spindle inhibitors, whilst DMT and DBT seem to be ineffective. The different effects of aryl versus alkyl and trivalent versus divalent organic substituents of tin on chromosome length may relate to different modes of action.
Structure–activity studies on the fungitoxicity of some triorganotin(IV) compounds
Authors: Kuthubtheen A J , Wickneswari R , Das V G Kumar
Published: January 2005

Seventeen triorganotin(IV) compounds, with the general formula R3SnX, containing symmetrical and unsymmetrical combinations of alkyl and aryl groups on tin and with a wide variation in the non‐carbon‐bonded anionic (X) residues, were examined along with three formally pentacoordinated adducts of triaryltin chlorides with triphenylphosphine oxide for their antifungal activity against nine plant pathogenic and saprophytic fungi. The in vitro tests included inhibitory studies on radial growth, mycelial growth, spore germination, and germ tube elongation. A significant finding was the dependence of fungitoxicity on the nature of the X group in both the tributyltin and triaryltin series, in contrast to earlier published reports on the negligible influence of the X groups on overall toxicity relative to the R group. This suggests that the X group is significantly involved in transporting the biocide to the reactive sites, and that the X group which tends to confer increased solubility to the triorganotin compound gives rise to increased activity.

In studies of R group variations, tri‐iso‐butyltin bromide was found to be much less fungitoxic than tri‐n‐butyltin compounds, a result which is reconcilable in terms of increased steric encumbrance at the tin site in the former case. The steric factor is also implicated in the reduced activities observed for tris(p‐tolyl)tin and tris(p‐chlorophenyl)tin compounds relative to (Ph3SnX) towards most of the fungi screened in this study. In general, it was also noted that the triaryltins were more selective in their antifungal action than the trialkyltins, which exhibited broad spectral activity when applied at the concentration level of 10 μg cm−3.
Efficacy of selected triorganotin(IV) compounds on leaves against Phytophthora palmivora (Butler) Butler isolated from black pepper and cocoa
Authors: Kuthubutheen A J , Wickneswari R , Kumar Das V G
Published: January 2005

Several triorganotin(IV) compounds and Terrazole® 35 WP were screened for their in vitro antifungal activity against three isolates of Phytophthora palmivora. Two isolates (isolates Phy. 2 and Phy. 334) were obtained from black pepper (Piper nigrum L.) and one isolate (isolate Phy. 56) from cocoa leaves (Cacao theobromae). ED50 values for radial growth of the isolates ranged from 0.09 to 1,700 μg cm−3 for the triorganotin(IV) compounds and from 3.46 to 1 227 000 μg cm−3 for Terrazole®. Diphenylbutyltin bromide exhibited the highest antifungal activity against the three isolates of P. palmivora with ED50 values ranging from 0.30 to 0.73 μg cm−3.

Diphenylbutyltin bromide was equally effective against a freshly isolated virulent culture of P. palmivora (isolate Phy. 346) from black pepper leaves in Sarawak, East Malaysia, yielding an ED50 value for radial growth of 0.87 μg cm−3 and a probit‐log concentration regression line slope value of 1.04. In vitro efficacy of diphenylbutyltin bromide against isolate Phy. 346 using detached healthy pepper leaves showed 40–75% infection of leaves at 100 μg cm−3 and no infection at 500 μg cm−3. Diphenylbutyltin bromide at 100 μg cm−3, however, inhibited the diameter of lesion by 43.3–73.7% compared with the untreated controls. Black pepper leaves treated with Terrazole® at 778 μg cm−3 exhibited 5.3–33.3% inhibition of lesion diameter compared with the untreated controls, where 90–100% of the leaves were infected. Concentrations of diphenylbutyltin bromide of 1000–2500 μg cm−3 caused some injury lesions on the leaves. From the results obtained, it appears that diphenylbutyltin bromide could be used as a protective spray or drench against P. palmivora infection of black pepper at 100–500 μg cm−3.
Biodegradation of bis(tri‐n‐butyltin) oxide
Authors: Shizhong Tian , Chau Y K , Liu D
Published: January 2005

Bis(tri‐n‐butyltin) oxide can be biodegraded by a mixed bacterial culture from activated sludge in cyclone fermentors under aerobic and anaerobic conditions with half‐lives of five and three days respectively. The degradation follows a sequential dealkylation process. All the intermediates and end products are determined in the degradation process for mass balance calculation. Degradation under different nutrient conditions has been investigated. Adsorption losses for each of the butyltin and inorganic tin species on container walls have also been assessed and discussed.
The determination of organotins (TBT) in fish and shellfish via gas chromatography–flame photometric detection and direct current plasma emission spectroscopy (GC–FPD/DCP)
Authors: Krull Ira S , Panaro Kenneth W , Noonan John , Erickson Donald
Published: January 2005

Gas chromatography (GC) has been interfaced very simply and inexpensively with a flame photometric detector (FPD) and a direct current plasma (DCP) atomic emission spectrometer in order to perform highly specific and selective determination of organotins in fish and shellfish samples. GC–FPD studies employed a fused‐silica, megabore column with a thin, immobilized stationary phase of DB‐17 (1 μm thickness), with a commercially available GC–FPD instrument. No prior alkylation or hydridization reactions were performed on the organotins; rather they were separated as the original, native species. Separate GC–FPD and GC–DCP injections and quantitative determinations have been performed, though simultaneous FPD/DCP detection on a single injection is suggested. This permitted routine qualitative and quantitative determinations of organotin species in complex food matrices (fish/shellfish) via both element selective detectors. Isothermal GC–FPD/DCP conditions permitted baseline resolution of all four tin species of interest today: monobutyl‐, dibutyl‐, tributyl‐ (TBT), and tetrabutyl‐tin. Optimization of the GC–DCP interface was accomplished, followed by a determination of detection limits and linearity of the calibration plots, and a comparison of the results with those obtained by the newer GC–FPD approach (which was also developed here). In three sample instances, qualitative and quantitative results for naturally occurring and spiked levels agreed for both the GC–FPD and GC–DCP approaches. Improved sample preparation and extraction procedures have been developed for organotins from fish samples involving extraction with an organic solvent, concentration, saponification, back‐extraction, and injection of the eluent onto the GC column. Quantitative levels of organotins (solely TBT) in fish and shellfish are reported for samples from Europe, Korea, Scandinavia, and the USA.
Conversion of arsenite and arsenate to methylarsenic and dimethylarsenic compounds by homogenates prepared from livers and kidneys of rats and mice
Authors: Hirata Miyuki , Mohri Takami , Hisanaga Akira , Ishinishi Noburu
Published: January 2005

Pooled livers and pooled kidneys from rats or mice were homogenized and spiked with arsenite or arsenate in the concentration range 1.3–20 μmol dm−3. Methylarsenic and dimethylarsenic compounds were determined by the hydride generation technique in the homogenates after a 90 min incubation at 37°C. The rat homogenates methylated arsenite and arsenate more efficiently than the mouse homogenates. Monomethylated arsenic was present in larger amounts than dimethylated arsenic in the rat homogenates. In the absence of reduced glutathione (GSH), no methylation occurred. Addition of GSH promoted monomethylation and dimethylation, whereas dithiothreitol and mercaptoethanol (10 mmol dm−3) fostered only monomethylation. The amounts of monomethylated arsenic in the rat liver homogenates increased with increasing arsenite concentration (1.3–20 μmol dm−3) however, the percentage of arsenic that had been methylated decreased. A similar trend, but with much less monomethylarsenic formed, was observed for arsenate‐spiked homogenates. Rat kidney homogenates methylated arsenite and arsenate to a much smaller extent than rat liver homogenates. The Km values for the monomethylation in rat liver homogenates were found to be 5.3 μmol dm−3 for arsenite and 59 μmol dm−3 for arsenate.
Thermolysis of the phenyltin chlorides, PhxSnCl4–x, (x=1−3): Products and pathways
Authors: Chandrasiri Jayakody A , Wilkie Charles A
Published: January 2005

The thermal degradation of triphenyltin chloride, diphenyltin dichloride and phenyltin trichloride has been studied by pyrolysis at 375°C in sealed tubes for various time periods. In all cases, biphenyl and tin(II) chloride are produced. For both phenyltin trichloride and diphenyltin dichloride, ter‐ and poly‐phenyls are also obtained. In some cases tin(IV) chloride or elemental tin are obtained. Pathways that account for all observed products are presented.
Synthesis of poly‐yne polymer containing platinum and silicon atoms in the main chain by oxidative coupling and its reactions with transition‐metal carbonyl complexes
Authors: Matsumoto Toshihiro , Kotani Sonae , Shiina Kyo , Sonogashira Kenkichi
Published: January 2005

The platinum poly‐yne polymer, [CCSiMe2CCPt(PBu3)2CCSiMe2CC]n (2), was synthesized by the oxidative coupling of a silicon–platinum monomer, trans‐(PBu3)2Pt(CCSiMe2–CCH)2 (1). The reaction of platinum poly‐yne polymer 2 with dicobaltoctacarbonyl gave μ‐coordinated complexes, {[CCSiMe2CCPt(PBu3)2CCSiMe2CC] [Co2(Co)6]2}n (4). the electric conductivity of iodine adducts of the polymer complexes 4 was 3.0×10−5 S cm−1. As an aid to spectroscopic characterization of the polymer complex 4, a model complex, {trans‐[(PBu3)2Pt(CCSiMe2CCH)2]} {[Co2(CO)6]2} (3), was also prepared by the reaction of 1 with dicobaltocatacarbonyl. Selective coordination of Co2(CO)6 groups to SiMe2CC CCSi(Me)2 Moieties and coordinative inertness of the PtCC moieties were confirmed by comparison of the NMR spectra of 3 with those of 4. All new compounds have been characterized by analytical and spectral analysis (IR, 1H NMR).
Synthesis of 2‐substituted pyridines catalyzed by cobalt(I) complexes and promoted by light
Authors: Heller Barbara , Reihsig Jonathan , Schulz Wolfgang , Oehme Günther
Published: January 2005

A series of pyridines substituted in the 2‐position were synthesized by cobalt(I)‐catalyzed cotrimerization of alkynes and nitriles. The reactions are usually enhanced by light. The reaction conditions are very mild. Activity and selectivity are satisfactory with respect to formation of pyridines, but depend on the type of nitrile.
Synthesis of inorganic polymers as glass precursors and for other uses: Pre‐ceramic block or graft copolymers as potential precursors to composite materials
Authors: Youngdhal K A , Hoppe M L , Laine R M , Rahn J A , Harrod J F
Published: January 2005

Pre‐ceramic block or graft copolymers may offer entrée into nanocomposite ceramics provided the two homopolymers are immiscible and one can carefully control the size of the blocks or grafts. We are exploring the possibility of making copolymers from methylsilsesquioxane, [MeSi(O)1.5]x, (SiO), a precursor to ‘black glass’ and the polysilazane, [MeHSiNH]x, (SiMe), a precursor to silicon carbide nitride. Our initial effors have been directed towards delineating the chemical transformations that SiO, prepared by room‐temperature catalytic redistribution of [MeHSiO]x using Cp2TiMe2as the catalyst (0.1 wt %), undergoes as it is heated to 900 °C in nitrogen. We find that, although Cp2TiMe2will not catalyze the redistribution of SiMe at room temperature, in the presence of even small amounts of [MeHSiO]x it is an active catalyst precursor and a copolymer can be formed. Spectra and chemical composition studies on the pyrolysis products of the copolymers and SiO are described.
Synthesis of carboxylic esters from aldehydes using metal carbonyl anions, part 2. Dimerization of aldehydes to carboxylic esters catalyzed by disodium pentacarbonylchromate, na2[cr(co)5]
Authors: Ohishi Takahiro , Matsumoto Tokuji , Yamashita Masakazu
Published: January 2005

Na2[Cr(CO)5] (1) was found to be an efficient catalyst for the dimerization of aldehydes to carboxylic esters. Several aromatic aldehydes including furfural gave the corresponding esters in good yields. This reaction also proceeded intramolecularly to give phthalide from phthalaldehyde. Compared with M2[Fe(CO)4] (M = Na, K), 1 was found to be a more efficient catalyst for this reaction. However, aliphatic aldehydes gave aldolcondensation products instead of the corresponding esters. In the reactions of p‐substituted benzaldehydes with 1, the reactivity decreased with the increase of the electron‐releasing ability of the substituents. However, even p‐anisaldehyde, which hardly reacted with M2[Fe(CO)4], reacted with 1 to give the ester in moderate yield. The reaction mechanism, including the nucleophilic attack of the pentacarbonylchromate dianion on the carbonyl carbon, is discussed.
Stannacycloalkyl and stannepinyl derivatives of dipeptides
Authors: Koch Jost , Huber Friedo , Ruisi Giuseppe , Barbieri Renato
Published: January 2005

Stannacyclohexyl and stannacycloheptyl derivatives of dipeptides (CH2)nSnAA · xH2O (H2AA = H2GlyGly, with n = 5, x = 2 or n = 6, x = 1; H2AA = H2GlyAla, H2GlyVal, H2GlyMet, with n = 5, 6, x = 1) and stannepinyl glycylglycinate monohydrate have been obtained by the reaction of (CH2)nSnCl2 or stannepinyl dichloride with Na2AA. According to infrared and 119Sn Mössbauer data of the solid compounds, AA acts as a tridentate ONN ligand and tin has a trigonalbipyramidal environment. An analogous structure has been inferred from 1H, 13C, and 119Sn NMR data for the undissociated molecules in methanol solution.
The lon‐chromatographic behavior of arsenite, arsenate, methylarsonic acid and dimethylarsinic acid on the hamilton PRP‐X100 anion‐exchange column
Authors: Gailer JÜRgen , Irgolic Kurt J.
Published: January 2005

The HPLC separation of arsenite, arsenate, methylarsonic acid and dimethylarsinic acid has been studied in the past but not in a systematic manner. The dependence of the retention times of these arsenic compounds on the pH of the mobile phase, on the concentration and the chemical composition of buffer solutions (phosphate, acetate, potassium hydrogen phthalate) and on the presence of sodium sulfate or nickel sulfate in the mobile phase was investigated using a Hamilton PRP‐X100 anion‐exchange column. With a flame atomic absorption detector and arsenic concentrations of at least 10 mg dm−3 all investigated mobile phases will separate the four arsenic compounds at appropriate pH values in the range 4–8. The shortest analysis time (˜3 min) was achieved with a 0.006 mol dm−3 potassium hydrogen phthalate mobile phase at pH 4, the longest (˜10 min) with 0.006 mol dm−3 sodium sulfate at pH 5.9 at a flow rate of 1.5 cm3 min−1. With a graphite furnace atomic absorption detector at the required, much lower, flow rate of ˜0.2 cm3 min−1 acceptable separations were achievable only with the pH 6 phosphate buffer (0.03 mol dm−3) and the nickel sulfate solution (0.005 mol dm−3) as the mobile phase. To become detectable approximately 100 ng arsenic from each arsenic compound (100 μl injection) must be chromatographed with the phosphate buffer, and approximately 10 ng with the nickel sulfate solution.
Biocidal organotin compounds: Part 1. Preparation and characterization of triorganotin(IV) 4‐pyridyl‐ and 2‐pyrimidyl‐ thioacetates and the crystal structure of triphenyltin(2‐pyrimidylthioacetate)
Authors: Chakrabarti A. , Kamruddin Sk. , Chattopadhyaya T. K. , Roy A. , Chakraborty B. N. , Molloy K. C. , Tiekink E. R. T.
Published: January 2005

The preparation and spectroscopic characterization of [R3Sn(O2CCH2SC5H4N‐4)], R == Ph, benzyl (Bz), cyclohexyl (c‐Hex) and n‐Bu, and of [R3Sn(O2CCH2SC4H3N2‐2,6)], R == Me, Ph and n‐Bu, are reported. The 2‐pyrimidyl compounds feature trigonal bipyramidal tin centres with trans‐R3SnO2 geometries as was confirmed by X‐ray crystallography for [Ph3Sn(O2CCH2SC4H3N2‐2,6)]. ¶ By contrast the 4‐pyridyl compounds have trigonal bipyramidal geometries in the solid state (arising from intermolecular Sn…N interaction) and tetrahedral geometries in solution. The biocidal activity of these compounds against the fungi Helminthosporium maydis (ITCC 2675) and H. oryzae (ITCC 2675), both of which damage crops such as maize and rice, shows promise. Encouraging is the observation that the compounds show no adverse phytotoxicity at concentrations to 10−3M.
Generation of (α‐aminoalkyl)samarium(III) by a new method of metalation and its carbon–carbon bond‐forming reactions
Authors: Murakami Masahiro , Hayashi Minoru , Ito Yoshihiko
Published: January 2005

(α‐Aminoalkyl)samarium(III) is generated on treatment of a tertiary amine having a pendant o‐iodobenzyl group on the nitrogen atom with samarium(II) iodide (SmI2) in tetrahydropyran containing hexamethylphosphoramide. Deuterium incorporation experiments demonstrate that the reaction proceeds via a delivery of a radical center from the pendant benzyl group to the α‐position of nitrogen and the following one‐electron transfer from SmI2 to the delivered radical. Subsequent nucleophilic addition of (α‐aminoalkyl)samarium (III) to various electrophiles, such as enolizable ketones, isocyanate and isocyanide, furnishes the C‐C bond formation products in good yields. The pendant benzyl group of the product can be readily removed by hydrogenolysis to give the corresponding secondary amine. Therefore, the present reaction provides a useful synthetic process for a variety of nitrogen‐containing compounds including β‐amino alcohols and α‐amino acid derivatives, disclosing a new method for metalation and C‐C bond formation.
Ytterbium tricyanide: Preparation and catalytic activity for the addition of cyanotrimethylsilane to carbonyl compounds
Authors: Utimoto Kiitiro , Takai Tsutomu , Kasuga Yuri , Matsubara Seijiro
Published: January 2005

Ytterbium tricyanide was obtained quantitatively by the reaction of ytterbium tri‐isopropoxide with cyanotrimethylsilane. The addition of cyanotrimethylsilane to various carbonyl compounds was catalyzed effectively by ytterbium tricyanide to proceed under mild conditions giving the adducts in high selectivities. 2‐Methylcyclohexanone yielded the adduct in a highly diastereoselective manner and the reagent system also effectively gave the adducts from easily enolizable ketones as well as from acid‐sensitive ones. α,β‐Unsaturated ketones and aldehydes afforded 1,2‐adducts exclusively.
Synthesis of tertiary phosphine oxides mediated by SmCp2 or Sml2
Authors: Dallemer F. , Collin J. , Kagan H. B.
Published: January 2005

Tertiary phosphine oxides are prepared under mild conditions by sequential addition of diphenylphosphinoyl chloride to divalent samarium compounds (SmCp2 and SmI2) followed by reaction with various electrophiles such as organic halides, tosylates, epoxides or α,β‐unsaturated ketones. Biscyclopentadienylsamarium (SmCp2) gives better yields than SmI2. Similar reactions, using phenylphosphonoyl dichloride, SmI2 and subsequent addition of two equivalents of activated halides, yield the corresponding tertiary phosphine oxides.
A new reduction system by the combination of lanthanoid metals (Ln) and Lnl2: Deoxygenative coupling of amides to vic‐diaminoalkenes
Authors: Ogawa Akiya , Nanke Taizoh , Takami Noriaki , Sekiguchi Masahito , Kambe Nobuaki , Sonoda Noboru
Published: January 2005

Deoxygenative coupling of aromatic amides takes place successfully by the use of a mixed system comprising of ytterbium metal and ytterbium diiodide, providing the corresponding vic‐diaminoalkenes in good yields. The same reaction does not take place if Yb metal or YbI2 is used alone. These results suggest novel enhancement of reducing ability by the combination of ytterbium(0) and ytterbium(II) diiodide. The Yb/YbI2 system is also effective for dethiolative coupling of thioamides, as sulfur analogues of amides. This paper also deals with reductive coupling of thioamides and selenoamides by using an Sm/SmI2 mixed system.
Reaction of (Cp2*LnH)2 (LnY, La) and Cp2* Y(2‐C6H4CH2NME2) with esters and amides and molecular structure of [Cp2* Y (μ‐OCMeCHC(OEt)O)]2
Authors: Deelman Berth‐Jan , Wierda Feike , Meetsma Auke , Teuben Jan H.
Published: January 2005

The activation of esters and amides by (Cp2* LnH)2 [LnY (1a), LnLa (1b), Cp*C5Me] and Cp2* Y (2‐C6H4CH2NMe2) (2) is described. Compounds 1a and 1b react with ethyl acetate to form Cp2* YOEt (3a) and Cp2*LaOEt (3b). With 1a and ethyl benzoate a 1:1 mixture of 3a and Cp2*YOCH2Ph (4a) is produced and the corresponding 1:1 mixture of 3b and Cp2*LaOCH2Ph (4b) is observed with 1b. Ethyl acrylate is polymerized rapidly by both 1a and 1b. The reaction of 1a with N,N‐dimethyl‐acetamide leads to a mixture of the carbonyl insertion product Cp2* Y(OCH(NMe2)Me) (5) and the aldol condensation product Cp2*Y(OC(NMe2)(Me)CH2C(O)NMe2) (6.). Formation of the condensation product [Cp2*Y(μ‐OCMe=CHC(OEt)O)]2 (7) occurred when 2 was reacted with ethyl acetate. The molecular structure of 7 was determined by X‐ray diffraction: a = 10.129(1) Å, b = 10.650(1) Å, c = 12.093(1) Å, α = 77.642(6)°, β = 79.402(7), γ = 86.408(9), V, 1252.2(2) Å3, space group P 1―, Z = 1. Anisotropic least‐squares refinement based on 4871 reflections converged to RF = 0.034 and Rw = 0.041 for 428 refined parameters. The more sterically hindered ester ethyl 2‐methylpropanoate reacted with 2 to produce the enolate complex Cp2*Y{OC(2‐C6H4CH2NMe2)=CMe2} (Me2CHCOOEt) (8). With N,N‐dimethylacetamide 2 gives a clean aldol condensation to form 6.
Relationships between hydrodynamics and rheology of flocculating yeast suspensions in a high‐cell‐density airlift bioreactor
Authors: Klein Jaroslav , Maia João , Vicente António A. , Domingues Lucília , Teixeira José A. , Juras̆c̆ík Martin
Published: January 2005

In this article a hydrodynamic and rheological analysis of a continuous airlift bioreactor with high‐cell‐density system is presented. A highly flocculating recombinant strain of Sacharomyces cerevisiae containing genes for lactose transport (lactose permease) and hydrolysis (β‐galactosidase) was exploited to ferment lactose from cheese whey to ethanol. The magnetic particle‐tracer method was used to assess the effect of operational conditions (air‐flow rate, biomass concentration) on hydrodynamic behavior of an airlift bioreactor during the fermentation process. Measurements of liquid circulation velocity showed the existence of a critical value of biomass concentration at which a dramatic deceleration of net liquid flow appeared with increasing biomass quantity. Rheological analysis revealed exponential increase of viscosity of the yeast floc suspension at the same biomass concentration of about 73 g/dm3 corresponding to 42.8% v/v of solid fraction. These facts have a particular importance for the successful processing of a high‐cell‐density airlift bioreactor as only a circulated flow regime will be favorable to keep the solid particles in suspension state and evenly distributed throughout the bioreactor. © 2004 Wiley Periodicals, Inc.
Identification of a core set of genes that signifies pathways underlying cardiac hypertrophy
Authors: Strøm Claes C. , Kruhøffer Mogens , Knudsen Steen , Stensgaard‐Hansen Frank , Jonassen Thomas E. N. , Ørntoft Torben F. , Haunsø Stig , Sheikh Søren P.
Published: January 2005

Although the molecular signals underlying cardiac hypertrophy have been the subject of intense investigation, the extent of common and distinct gene regulation between different forms of cardiac hypertrophy remains unclear. We hypothesized that a general and comparative analysis of hypertrophic gene expression, using microarray technology in multiple models of cardiac hypertrophy, including aortic banding, myocardial infarction, an arteriovenous shunt and pharmacologically induced hypertrophy, would uncover networks of conserved hypertrophy‐specific genes and identify novel genes involved in hypertrophic signalling. From gene expression analyses (8740 probe sets, n = 46) of rat ventricular RNA, we identified a core set of 139 genes with consistent differential expression in all hypertrophy models as compared to their controls, including 78 genes not previously associated with hypertrophy and 61 genes whose altered expression had previously been reported. We identified a single common gene program underlying hypertrophic remodelling, regardless of how the hypertrophy was induced. These genes constitute the molecular basis for the existence of one main form of cardiac hypertrophy and may be useful for prediction of a common therapeutic approach. Supplementary material for this article can be found at: http://www.interscience.wiley.com/jpages/1531‐6912/suppmat Copyright © 2004 John Wiley & Sons, Ltd.
Meeting report: The Institute for Genomic Research/Wellcome Trust Conference: Genomes 2004 14–17 April 2004, The Wellcome Trust Conference Centre, The Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
Authors: Wixon Jo
Published: January 2005

This conference brought the microbial genomics community together to share their most up‐to‐the‐minute achievements, so much so that several talks cannot be covered here, as the work discussed has not yet been published. This meeting report has details of a cross‐section of the talks from the sessions on ‘Genome analysis and comparative genomics’, ‘Computational genomics’ and ‘Functional genomics’, ranging from studies on complex environmental samples, to specific pathogenic bacteria, to yeasts. Copyright © 2004 John Wiley & Sons, Ltd.
The SOFG anatomy entry list (SAEL): an annotation tool for functional genomics data
Authors: Parkinson Helen , Aitken Stuart , Baldock Richard A. , Bard Jonathan B. L. , Burger Albert , Hayamizu Terry F. , Rector Alan , Ringwald Martin , Rogers Jeremy , Rosse Cornelius , Stoeckert Christian J. , Davidson Duncan
Published: January 2005

A great deal of data in functional genomics studies needs to be annotated with low‐resolution anatomical terms. For example, gene expression assays based on manually dissected samples (microarray, SAGE, etc.) need high‐level anatomical terms to describe sample origin. First‐pass annotation in high‐throughput assays (e.g. large‐scale in situ gene expression screens or phenotype screens) and bibliographic applications, such as selection of keywords, would also benefit from a minimum set of standard anatomical terms. Although only simple terms are required, the researcher faces serious practical problems of inconsistency and confusion, given the different aims and the range of complexity of existing anatomy ontologies. A Standards and Ontologies for Functional Genomics (SOFG) group therefore initiated discussions between several of the major anatomical ontologies for higher vertebrates. As we report here, one result of these discussions is a simple, accessible, controlled vocabulary of gross anatomical terms, the SOFG Anatomy Entry List (SAEL). The SAEL is available from http://www.sofg.org and is intended as a resource for biologists, curators, bioinformaticians and developers of software supporting functional genomics. It can be used directly for annotation in the contexts described above. Importantly, each term is linked to the corresponding term in each of the major anatomy ontologies. Where the simple list does not provide enough detail or sophistication, therefore, the researcher can use the SAEL to choose the appropriate ontology and move directly to the relevant term as an entry point. The SAEL links will also be used to support computational access to the respective ontologies. Copyright © 2004 John Wiley & Sons, Ltd.
Growth factor‐responsive progenitors in the postnatal mammalian retina
Authors: Zhao Xing , Das Ani V. , Soto‐Leon Frank , Ahmad Iqbal
Published: January 2005

It is thought that the adult mammalian retina lacks the regenerative capacity of fish and amphibians retina because it does not harbor a progenitor population. However, recent observations suggest that another derivative of the optic neuroepithelium, the ciliary body, contains a mitotically quiescent population of neural progenitors that proliferate in the presence of growth factors and demonstrate properties of neural stem cells. Examination of the hypothesis that similar mitotically quiescent and growth factor‐responsive progenitors may exist in the postnatal retina revealed a population of cells located in the periphery of the retina that displayed proliferative responsiveness to growth factors and possessed potential to support neurogenesis. Given their marginal position and neural properties and potential, these cells may represent a residual population of retinal progenitors, analogous to those found in the ciliary marginal zone of fish and amphibians. Their progressive decrease in proliferative potential and number in postnatal stages suggests a temporal decline in regulatory signaling that supports their maintenance during retinal neurogenesis. Developmental Dynamics 232:349–358, 2005. © 2005 Wiley‐Liss, Inc.
Accounting for haplotype uncertainty in matched association studies: A comparison of simple and flexible techniques
Authors: Kraft Peter , Cox David G. , Paynter Randi A. , Hunter David , De Vivo Immaculata
Published: January 2005

Population‐based case‐control studies measuring associations between haplotypes of single nucleotide polymorphisms (SNPs) are increasingly popular, in part because haplotypes of a few “tagging” SNPs may serve as surrogates for variation in relatively large sections of the genome. Due to current technological limitations, haplotypes in cases and controls must be inferred from unphased genotypic data. Using individual‐specific inferred haplotypes as covariates in standard epidemiologic analyses (e.g., conditional logistic regression) is an attractive analysis strategy, as it allows adjustment for nongenetic covariates, provides omnibus and haplotype‐specific tests of association, and can estimate haplotype and haplotype × environment interaction effects. In principle, some adjustment for the uncertainty in inferred haplotypes should be made. Via simulation, we compare the performance (bias and mean squared error of haplotype and haplotype × environment interaction effect estimates) of several analytic strategies using inferred haplotypes in the context of matched case‐control data. These strategies include using only the most likely haplotype assignment, the expectation substitution approach described by Stram et al. ([2003b] Hum. Hered. 55:179–190) and others, and an improper version of multiple imputation. For relatively uncomplicated haplotype structures and moderate haplotype relative risks (≤2), all methods performed comparably well (small bias with appropriately‐sized confidence intervals). For larger relative risks, the most likely haplotype and multiple imputation strategies showed noticeable bias towards the null; the expectation substitution strategy still performed well. When there was more uncertainty in the inferred haplotypes, the most likely and multiple imputation strategies showed even more bias towards the null, while the expectation substitution method had slightly smaller than nominal confidence intervals for larger relative risks (≥5). An application to progesterone‐receptor haplotypes and endometrial cancer further illustrates that the performance of all these methods depends on how well the observed haplotypes “tag” the unobserved causal variant. Genet. Epidemiol. © 2005 Wiley‐Liss, Inc.
Liquid chromatographic/electrospray ionization tandem mass spectrometric analysis for the quantification of buprenorphine, norbuprenorphine, buprenorphine‐3‐β‐D‐glucuronide and norbuprenorphine‐3‐β‐D‐glucuronide in human plasma
Authors: Murphy Constance M. , Huestis Marilyn A.
Published: January 2005

A liquid chromatographic/electrospray ionization tandem mass spectrometric method for the quantification of the synthetic opiate buprenorphine (BUP), norbuprenorphine (NBUP), buprenorphine‐3‐β‐D‐glucuronide (BUP‐3‐G) and norbuprenorphine‐3‐β‐D‐glucuronide (NBUP‐3‐G) in human plasma was developed and validated. Identification and quantification were based on the following transitions: m/z 468 to 396 and 414 for BUP, m/z 414 to 326 and 340 for NBUP, m/z 644 to 468 for BUP‐3‐G and m/z 590 to 414 for NBUP‐3‐G. Calibration by linear regression analysis utilized deuteratated internal standards and a weighting factor of 1/x. The method was accurate and precise across a linear dynamic range of 0.6–50.0 ng ml−1. Pretreatment of plasma samples using solid‐phase extraction was sufficient to limit matrix suppression to <30% for all four analytes. The method proved to be suitable for the quantification of BUP and the related metabolites in plasma samples collected from BUP‐maintained study participants. Copyright © 2004 John Wiley & Sons, Ltd.
Novel function of neuronal PAS domain protein 1 in erythropoietin expression in neuronal cells
Authors: Ohsawa Shizue , Hamada Shun , Kakinuma Yoshihiko , Yagi Takeshi , Miura Masayuki
Published: January 2005

The basic helix loop helix‐PAS (bHLH‐PAS) transcription factors have diverse roles in physiologic responses to the environment and in early development. One bHLH‐PAS protein, neuronal PAS domain protein 1 (NPAS1), is reported to be expressed only in the central nervous system beginning at the late embryonic stage, but its function is unknown. Using an anti‐NPAS1 antibody, we have shown that NPAS1 expression in cerebral cortex was observed first around embryonic Day 16.5 (E16.5) and was then dispersed throughout the region as cortical development progressed. From the similarity with hypoxia‐inducible factor‐1α (HIF‐1α), we investigated whether NPAS1 regulates transcription of erythropoietin (EPO), which is the target of HIF‐1α and is expressed in the brain during the early developmental stage. In the present study, we have shown that NPAS1 binds to the enhancer region of Epo in vivo. A luciferase reporter assay revealed a repressive effect of NPAS1 on hypoxia‐responsive element‐regulated gene expression. These results raise the possibility that NPAS1 plays a role in late central nervous system development by modulating EPO expression in response to cellular oxygen level. © 2005 Wiley‐Liss, Inc.
The pyrolysis of trimethylene sulfide. A unimolecular decomposition
Authors: Jeffers P. , Dasch C. , Bauer S. H.
Published: January 2005

The kinetics of decomposition of trimethylene sulfide to ethylene and thioformaldehyde was investigated in a single‐pulse shock tube using the «relative rate» technique. The extent of reaction was measured in the reflected shock regime from 860° to 1170°K, but experimental difficulties limited the useful data to the temperature range of 980°–1040°K. The first‐order rate constant was found to be k = 1013.0 exp (−48,200/RT) sec−1. This result sets an upper limit of 50 kcal/mole for the standard enthalpy of formation of CH2S, with 35 kcal/mole as a more likely value. The isomerization of cyclopropane to propene was used for the reference reaction; in turn, this was checked, in a relative rate experiment, against the pyrolysis of cyclohexene.
A differential technique which is independent of initial conditions for calculating the rate constant of a second‐order reaction
Authors: Wen Walter Y.
Published: January 2005

It has been shown that experimental errors of the initial conditions of a second‐order reaction can cause erroneous results with the rate constant calculated directly from the differential or integrated rate expression. By means of a computer method, a differential technique has been developed so that precise initial reactant conditions are not necessary for calculating a second‐order rate constant if continuous measurements of a single reaction variable are available. The technique has been successfully applied to the data of Kistiakowsky and Lacher on the condensation of acrolein and butadiene.
A classical trajectory study of the effect of reaction barrier height on the vibrational energy transfer efficiency in the Cl + HCl system
Authors: Thommarson Ronald L. , Berend George C.
Published: January 2005

The effects of reaction barrier height and initial rotational excitation of the reactants on the overall rate of H atom exchange between atomic chlorine and HCl (v = 0) and on the 0 → 1 vibrational excitation of HCl via reactive and nonreactive collisions have been investigated using quasiclassical trajectory techniques. Two empirical LEPS potential energy surfaces were employed in the calculations having reaction barrier heights of 9.84 and 7.05 kcal mol−1. Trajectory studies of planar collisions were carried out on each surface over a range of relative translational energies with the ground‐state HCI collision partner given initial rotational excitation corresponding J = 0, 3, and 7. Initial molecular rotation was found to be relatively inefficient in promoting the H atom exchange; the computed rate coefficient for H atom exchange between Cl + HCl (v = 0, J = 7) was only 4 times larger than that for CI + HCI (v = 0, J = 0). The vibrational excitation rate coefficient exhibited a stronger dependence on initial molecular rotational excitation. The observed increase in the vibrational excitation rate coefficient with increasing initial molecular rotational excitation was due primarily to nonreactive intermolecular R → V energy transfer. The vibrational excitation rate coefficients increase with decreasing reaction barrier height.