bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diurnal patterns of urinary steroid excretion in wild chimpanzees
Authors: Muller Martin N. , Lipson Susan F. 
Published: August 2003

AbstractUrinary testosterone and cortisol concentrations were quantified in a large number of samples (>500) collected from wild male chimpanzees (n=11) over the course of 1 year. For both steroids, urinary concentrations were higher and more variable in the morning than in the afternoon. Urinary creatinine levels showed no such diurnal pattern. These patterns are consistent with studies of steroid excretion in humans and gorillas. This study emphasizes the importance of considering time of day as a confounding variable in field studies of primate endocrine function. It also suggests that if a small number of samples are to be used to characterize an individual's basal steroid levels, afternoon samples may be preferable because they show less intra‐individual variability. Am. J. Primatol. 60:161–166, 2003 © 2003 Wiley‐Liss, Inc.
Crystallographic report: Tribenzyltin(IV) azide
Authors: Burke Anthony C. , Mahon Mary F. , Molloy Kieran C. 
Published: August 2003

AbstractTribenzyltin azide adopts a polymeric structure with 1,3‐bridging azide groups; the tin exhibits an almost regular trigonal bipyramidal trans‐N2SnC3 environment. Copyright © 2003 John Wiley & Sons, Ltd.
Life‐cycle toxicity of dibutyltin to the sheepshead minnow (Cyprinodon variegatus) and implications of the ubiquitous tributyltin impurity in test material
Authors: Lytle Thomas F. , Manning Charles S. , Walker William W. , Lytle Julia S. , Page David S. 
Published: August 2003

AbstractDibutyltin (DBT) is used in the plastics polymerization process as a catalyst in polyvinyl chloride (PVC) products and is the primary degradation product of tributyltin (TBT), an antifoulant in marine paint. DBT and other organotin compounds make their way into the environment through antifoulants, PVC processing plants, and PVC products maintained in water and water‐handling systems. A flow‐through saltwater life‐cycle toxicity test was conducted to determine the chronic effect of DBT to the sheepshead minnow (Cyprinodon variegatusLacepede), an estuarine species. Embryos were monitored through hatch, maturation, growth, and reproduction in DBT concentrations of 158, 286, 453, 887, and 1510 µg l−1. Progeny were monitored for survival as embryos and fry/juveniles, and growth for 30 days post‐isolation. Mean length of parental generation fish was significantly reduced on day 30 at DBT concentrations ≥887 µg l−1, setting the lowest observable effect concentration (LOEC) at 887 µg l−1and the no observable effect concentration (NOEC) at 453 µg l−1. Fecundity, as egg viability, was significantly reduced at the LOEC. Survival of parental and progeny generation embryos and mean length, wet weight and dry weight of progeny generation juveniles were not significantly affected at concentrations ≤LOEC. TBT, a toxic impurity in DBT reversibly produced in DBT by the process of comproportionation, was also monitored throughout this study. Comparing measured levels of TBT in this study with levels exerting toxic effects in an earlier TBT life‐cycle study withC. variegatussuggests biological responses in this study were likely due to the TBT impurity and not to DBT alone. Results indicate that TBT impurity as low as 0.1% may have a significant influence on the perceived toxicity of DBT and that spontaneous production of TBT in DBT may be the major source of biological toxicity of DBT. Copyright © 2003 John Wiley & Sons, Ltd.
Chelate polymers: II. Some novel transition metals complexes with azomethine‐containing siloxanes and their polyesters
Authors: Marcu Mihai , Cazacu Maria , Vlad Angelica , Racles Carmen 
Published: August 2003

AbstractNew Schiff bases of 2,4‐dihydroxybenzaldehyde with siloxane‐α,ω‐diamines having different numbers of siloxane units in the chain have been synthesized and characterized by spectroscopy, elemental and thermal analyses. These azomethines were found to form complexes readily with copper(II), nickel(II), cobalt(II), cadmium(II) and zinc(II). From IR and UV–Vis studies, the phenolic oxygen and imine nitrogen of the ligand were found to be the coordination sites. Thermogravimetric analysis (TGA) data indicate the chelates to be more stable than the corresponding ligands. The melting points increase with shortening of the siloxane segment from azomethine, as well as the result of complexation. The chelates obtained were covalently inserted in polymeric linear structures by polycondensation through the OH‐difunctionalized ligand with 1,3‐bis(carboxypropyl)tetramethyldisiloxane. Direct polycondensation, assisted either by acetic anhydride or N,N′‐dicyclohexylcarbodiimide as dehydrating agent and the complex 4‐(dimethylamino)pyridinium 4‐toluenesulfonate as catalyst, was used for the synthesis of these compound types. The structures of the polymers obtained were confirmed by IR, UV and 1H NMR. Characterization was undertaken by TGA, solubility tests and viscosity measurements. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of arsenic species in sheep‐wool extracts by different chromatographic methods
Authors: Raab Andrea , Genney David R. , Meharg Andrew A. , Feldmann Jörg 
Published: August 2003

AbstractSheep on the island of North Ronaldsay (Orkney, UK) feed mostly on seaweed, which contains high concentrations of dimethylated arsenoribosides. Wool of these sheep contains dimethylated, monomethylated and inorganic arsenic, in addition to unidentified arsenic species in unbound and complexed form. Chromatographic techniques using different separation mechanisms and detectors enabled us to identify five arsenic species in water extracts of wool. The wool contained 5.2 ± 2.3 µg arsenic per gram wool. About 80% of the arsenic in wool was extracted by boiling the wool with water. The main species is dimethylarsenic, which accounted for about 75 to 85%, monomethylated arsenic at about 5% and the rest is inorganic arsenic. Depending on the separation method and condition, the chromatographic recovery of arsenic species was between 45% for the anion exchange column, 68% for the size exclusion chromatography (SEC) and 82% for the cation exchange column. The SEC revealed the occurrence of two unknown arsenic compounds, of which one was probably a high molecular mass species. Since chromatographic recovery can be improved by either treating the extract with CuCl/HCl (CAT: 90%) or longer storage of the sample (CAT: 105%), in particular for methylated arsenic species, it can be assumed that labile arsenic–protein‐like coordination species occur in the extract, which cannot be speciated with conventional chromatographic methods. It is clear from our study of sheep wool that there can be different kinds of ‘hidden’ arsenic in biological matrices, depending on the extraction, separation and detection methods used. Hidden species can be defined as species that are not recordable by the detection system, not extractable or do not elute from chromatographic columns. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Diaquacadmium bis(iminodiacetato)cobaltate, a two‐dimensional heterometallic network
Authors: Long La‐Sheng , Ren Yan‐Ping , Huang Rong‐Bin , Zheng Lan‐Sun , Ng Seik Weng 
Published: August 2003

AbstractIn the title compound, each Cd(H2O)22+ is linked to two carboxyl and two carbonyl oxygen atoms, all belonging to different [(NC4H5O4)2Co]2− moieties, to furnish a two‐dimensional heterometallic network. Both metal atoms display octahedral coordination. The layers are further held together by hydrogen bonding interactions. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Triorganotin 2‐(p‐chlorophenyl)‐3‐methylbutyrates
Authors: Song Xueqing , Cahill Christopher , Eng George 
Published: August 2003

AbstractThe crystal structures of two triorganotin butyrates were determined. Tricyclohexyltin 2‐(p‐chlorophenyl)‐3‐methylbutyrate was determined to have a distorted tetrahedral geometry. Trimethyltin 2‐(p‐chlorophenyl)‐3‐methylbutyrate, on the other hand, was found to be polymeric in nature with a trigonal bipyramidal configuration. The three methyl groups are located in the equatorial positions with the axial positions occupied by oxygen atoms from two different carboxylate groups. Copyright © 2003 John Wiley & Sons, Ltd.
Dihalodimethyltin(IV) complexes of 2‐(pyrazol‐1‐ylmethyl)pyridine
Authors: Álvarez‐Boo Pedro , Sergio Casas José , Castiñeiras Alfonso , Delfina Couce María , Freijanes Eduardo , Novoa Eva , Sordo José 
Published: August 2003

AbstractReaction of dichloro‐ and dibromodimethyltin(IV) with 2‐(pyrazol‐1‐ylmethyl)pyridine (PMP) afforded [SnMe2Cl2(PMP)] and [SnMe2Br2(PMP)] respectively. The new complexes were characterized by elemental analysis and mass spectrometry and by IR, Raman and NMR (1H, 13C) spectroscopies. Structural studies by X‐ray diffraction techniques show that the compounds consist of discrete units with the tin atom octahedrally coordinated to the carbon atoms of the two methyl groups in a trans disposition (SnC = 2.097(5), 2.120(5) Å and 2.110(6), 2.121(6) Å in the chloro and in the bromo compounds respectively), two cis halogen atoms (SnCl = 2.4908(16), 2.5447(17) Å; SnBr = 2.6875(11), 2.7464(9) Å) and the two donor atoms of the ligand (SnN = 2.407(4), 2.471(4) Å and 2.360(5), 2.455(5) Å). In both cases, the SnN(pyridine) bond length is markedly longer than the SnN(pyrazole) distance. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: The crystal structure of 2‐benzo[b]thienylgermatrane
Authors: Lukevics Edmunds , Ignatovich Luba , Shul'ga Tatyana , Belyakov Sergey 
Published: August 2003

AbstractThe germanium atom is penta‐coordinated and adopts trigonal bipyramidal geometry. The 2‐benzo[b]thienyl group and the nitrogen atom each occupy an apical position with the transannular N → Ge bond distance being 2.180(4) Å. Copyright © 2003 John Wiley & Sons, Ltd.
Morphological characterization of poly(phenylacetylene) nanospheres prepared by homogeneous and heterogeneous catalysis
Authors: Mastrorilli Piero , Nobile Cosimo Francesco , Suranna Gian Paolo , Corradi Anna , Leonelli Cristina , Veronesi Paolo 
Published: August 2003

AbstractScanning electron microscopy characterization of the materials obtained by homogeneous and heterogeneous catalytic polymerization of phenylacetylene is described. The catalysts used are β‐dioxygenato rhodium(I) complexes. The effects of the reaction medium, presence of a cocatalyst and the type of catalysis (homogeneous or heterogeneous) on the morphology of the polymers obtained have been studied and discussed. Using a supported complex at 0 °C, nanoparticles with a diameter distribution as narrow as 30 to 70 nm were obtained. Polymer nanopowders were found to be unaffected by ageing. Copyright © 2003 John Wiley & Sons, Ltd.
Biotransformation of arsenate to arsenosugars by Chlorella vulgaris
Authors: Murray Linda A. , Raab Andrea , Marr Iain L. , Feldmann Jörg 
Published: August 2003

AbstractChlorella vulgaris was cultivated in a growth medium containing arsenate concentration of <0.01, 10, 100 and 1000 mg l−1. Illumination was carried out in 12 h cycles for 5 days. The health status of the culture was monitored by continuous pH and dissolved oxygen (DO) readings. Destructive sampling was used for the determination of biomass, chlorophyll, total arsenic and arsenic species. The chlorophyll a content, the DO and pH cycles were not significantly different for the different arsenate concentrations in the culture. In contrast, biomass production was significantly (p < 0.05) increased for the arsenic(V) treatment at 1000 mg l−1 compared with 100 mg l−1.The arsenic concentration in the algae increased with the arsenate concentration in the culture. However, the bioconcentration factor decreased a hundred‐fold with increase of arsenate from the background level to 1000 mg l−1. The arsenic species were identified by using strong anion‐exchange high‐performance liquid chromatography–inductively coupled plasma mass spectrometry analysis after methanol/water (1 : 1) extraction. The majority (87–100%) of the extractable arsenic was still arsenate; arsenite was found to be between 1 and 6% of total extractable arsenic in the algae. In addition to dimethylarsinic acid, one unknown arsenical (almost co‐eluting with methylarsonic acid) and three different arsenosugars have been identified for the first time in C. vulgaris growing in a culture containing a mixture of antibiotics and believed to be axenic. The transformation to arsenosugars in the algae is not dependent on the arsenate concentration in the culture and varies between 0.2 and 5% of total accumulated arsenic. Although no microbiological tests for bacterial contamination were made, this study supports the hypothesis that algae, and not associated bacteria, produce the arsenosugars. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Crystal structure of 1‐bromo‐1′‐[(2S)‐N‐(1‐hydroxy‐3‐methylbutane‐2‐yl)]‐ferroceneamide
Authors: Arion Vladimir B. , Nazarov Alexey A. , Hartinger Christian G. , Giester Gerald , Keppler Bernhard K. 
Published: August 2003

AbstractFor the unsymmetrical title compound, 1‐bromo‐1′‐[(2S)‐N‐(1‐hydroxy‐3‐methylbutane‐2‐yl)]‐ferroceneamide, two independent molecules were found in the asymmetric unit. Copyright © 2003 John Wiley & Sons, Ltd.
Direct evidence for co‐binding of cisplatin and cadmium to a native zinc‐ and cadmium‐containing metallothionein
Authors: Mandal Rupasri , Jiang Guifeng , Li Xing‐Fang 
Published: August 2003

AbstractCisplatin is widely used to treat a number of cancers, and its covalent binding to DNA is believed to cause cell death; however, the roles of cisplatin–protein interactions in the mechanisms of action, toxicity, and resistance of the drug largely remain to be elucidated. Here, we investigate the interactions of cisplatin and a native rabbit metallothionein (MT), containing 1.4% zinc and 7.9% cadmium, using nanospray tandem quadrupole time‐of‐flight mass spectrometry (MS) and size‐exclusion high‐performance liquid chromatography with inductively coupled plasma MS. At near‐neutral pH conditions, reactions between cisplatin and MT resulted in the formation of complexes that contained Cd4–Ptn–MT (n = 1–7). While zinc was displaced by cisplatin, both platinum and cadmium were bound to the same MT molecule. This is the first report to provide direct evidence for the co‐binding of cadmium and platinum to MT, which suggests that the mechanism of the binding of cisplatin to the native MT may not be through the displacement of cadmium as previously proposed. A tandem MS investigation into the binding sites of the platinum and cadmium to MT showed platinum‐ and cadmium‐related fragments, such as (PtS2C2H7N)+ and (CdS3C5H17N2)+, demonstrating the platinum–cysteine and cadmium–cysteine binding. In addition, detection of Cd4–Pt7–MT demonstrated more than ten metals bound to a single MT molecule. This finding was extended to the binding of MT with a five‐fold excess of CdCl2. As many as 14 metal atoms (13 cadmium and one zinc) were detected bound to a single MT molecule, the complexes being Cdx–Zn–MT (x = 5–13). The high binding capacity of MT for cadmium and platinum is consistent with the role of MT in reduction of metal toxicity and its involvement in drug resistance. Copyright © 2003 John Wiley & Sons, Ltd.
Prevalence, incidence, survival, and disease characteristics of systemic sclerosis in a large US population
Authors: Mayes Maureen D. , Lacey James V. , Beebe‐Dimmer Jennifer , Gillespie Brenda W. , Cooper Brenda , Laing Timothy J. , Schottenfeld David 
Published: August 2003

AbstractObjectiveTo estimate the prevalence, incidence, survival, and disease characteristics of systemic sclerosis (SSc) in the Detroit tricounty area.MethodsA census of SSc cases for the period 1989–1991 was conducted in the Detroit area, using multiple sources for case identification. Diagnoses were verified by medical record review. Capture‐recapture analysis was used to estimate the total SSc population. Cases of localized scleroderma (morphea and linear disease) were excluded.ResultsBased on 706 verified cases of SSc, prevalence was initially estimated to be 242.0 cases per million adults (95% confidence interval [95% CI] 213–274), with an annual incidence of 19.3 new cases per million adults per year (95% CI 12.4–30.2). Capture‐recapture analysis, based on the degree of overlap of verified cases among multiple sources, resulted in a revised prevalence estimate of 276 cases per million adults (95% CI 245–310). Sex‐ and race‐specific prevalence estimates were significantly higher for women than for men, and for blacks than for whites. The average age at diagnosis was significantly younger for blacks than for whites. Compared with white patients, black patients were almost twice as likely to have diffuse disease (prevalence proportion ratio 1.86, 95% CI 1.48–2.35). Median survival was ∼11 years. Factors negatively affecting survival included male sex (hazard ratio 1.81, 95% CI 1.29–2.55) and older age at diagnosis (hazard ratio 1.04, 95% CI 1.03–1.05).ConclusionThis study establishes baseline estimates of SSc occurrence and characteristics in a large US cohort consisting primarily of black adults and white adults. These data should facilitate research regarding the role of geographic, ethnic, racial, and environmental factors for this disease in comparison populations.
Limited versus severe Wegener's granulomatosis: Baseline data on patients in the Wegener's granulomatosis etanercept trial
Authors: Stone John H. 
Published: August 2003

AbstractObjectiveTo report baseline data on 180 patients with Wegener's granulomatosis (WG) enrolled in the WG Etanercept Trial (WGET), and to examine demographic and clinical differences between patients with limited disease and those with severe disease.MethodsDefinitions of limited and severe disease were agreed upon by consensus of the investigators at a pretrial meeting and were incorporated into the protocol as a stratification criterion. These data were applied prospectively to the WGET patient cohort, based on clinical features and the intention to treat patients according to disease activity. Data related to disease onset, date of diagnosis, clinical features, antineutrophil cytoplasmic antibody assays, tissue biopsy findings, and other medical history were collected on a baseline medical history form. Physician‐investigators from each center participated in the development of this form, and all were certified in its use prior to the start of the trial. Selected data on patients who were screened for the trial but were not enrolled were also collected.ResultsSeveral significant differences between the limited and severe disease subsets were observed. Patients with limited disease were nearly a decade younger at disease onset compared with patients with severe disease. Thirty‐three percent of patients with severe disease were women, compared with 58% of those with limited disease. Despite their younger age at symptom onset, patients with limited disease tended to have longer disease duration, a greater likelihood of experiencing exacerbation of previous disease following a period of remission, and a higher prevalence of destructive upper respiratory tract disorders at the time of enrollment (e.g., saddle‐nose deformity). Patients with limited WG were less likely than those with severe disease to have antibodies to either proteinase 3 or myeloperoxidase. Patients with severe disease had a higher likelihood of previous thyroid disease, particularly either Graves' disease or Hashimoto thyroiditis, suggesting the possibility of different pathogenetic factors within these disease subsets. Other observed differences between these subsets, such as the greater frequency of alveolar hemorrhage in the severe disease group, were related to the a priori definitions of limited and severe disease.ConclusionThere are significant differences between patients with limited WG and those with severe WG with regard to sex, age, the likelihood of recurrent disease, the risk of damage in certain organ systems, and, possibly, etiologic factors. These differences (and perhaps other differences that are currently unrecognized) in patient subsets may have implications for mechanisms of pathogenesis, prognosis, response to treatment, and the design of future clinical investigations.
New radiographic bone erosions in the wrists of patients with rheumatoid arthritis are detectable with magnetic resonance imaging a median of two years earlier
Authors: Østergaard Mikkel , Hansen Michael , Stoltenberg Michael , Jensen Karl Erik , Szkudlarek Marcin , Pedersen‐Zbinden Brigitta , Lorenzen Ib 
Published: August 2003

AbstractObjectiveIn a 5‐year followup study, we investigated the temporal relationship between development of wrist joint erosions as visualized by magnetic resonance imaging (MRI) versus conventional radiography (CR), in patients with rheumatoid arthritis. We also evaluated the risk of erosive progression on CR associated with the presence of MRI erosions.MethodsIn 10 patients with rheumatoid arthritis, MRI and CR of the dominant wrist were performed annually for 5 years. In each image set, each wrist bone (metacarpal bases, carpal bones, radius, and ulna) was assessed for the absence or presence of bone erosions.ResultsNine bones showed radiographic erosions at baseline. Twenty‐seven new radiographic erosions developed during the 5‐year followup period. Of these 27 new erosions, 21 were detected 1–5 years earlier by MRI than by CR, 3 were simultaneously detected by both methods, 2 were detected 1–2 years later by MRI than by CR, and 1 erosion (radiographically detected at 5‐year followup) was not visualized with MRI. MRI detection of new radiographic erosions preceded CR detection by a median of 2 years. In bones with MRI erosions at baseline, the relative risk of radiographic erosions at 5‐year followup was 4.5 (95% confidence interval [95% CI] 2.6–7.6), compared with bones without baseline MRI erosions. If bones with baseline radiographic erosions were excluded from the analysis, the relative risk was 4.1 (95% CI 2.2–7.5).ConclusionMost new radiographic bone erosions (78%) were visualized at least 1 year earlier by MRI than by CR. This illustrates that the information on joint destruction provided by CR is considerably delayed compared with that provided by MRI. A significantly increased risk of progression of radiographic erosion in bones with baseline MRI erosions was observed, demonstrating a prognostic value of MRI with respect to long‐term radiographic outcome.