bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient and Selective Epoxidation of Alkenes with Sodium Periodate Using Supported Manganese Porphyrins under Ultrasonic Irradiation
Authors: Tangestaninejad Shahram , Mirkhani Valiollah 
Published: December 2003

Abstract
Epoxides are readily obtained in high yields and good selectivities by ultrasonic irradiation of alkenes and sodium periodate in the presence of catalytic amounts of manganese porphyrins supported on polyvinylpyridine and IRA-900 ion-exchange resin.
Selective Oxidation of Propylene to Propylene Oxide or Propionaldehyde over Au Supported on Titanosilicates in the Presence of H2 and O2
Authors: Uphade B S , Tsubota Susumu , Hayashi Toshio , Haruta Masatake 
Published: December 2003

Abstract
Gas phase selective oxidation of propylene to propylene oxide (PO) or propionaldehyde (PA) in the presence of H2 and O2has been carried out with a propylene conversion in the range of 0.5-3.7% over gold deposited on titanosilicates by deposition-precipitation (DP) method; PO was obtained with a selectivity above 90% at the temperature range of 50 °C-120 °C whereas PA was obtained at temperatures higher than 200 °C with a selectivity above 70% over throughly washed catalysts with low Au loadings.
Zirconium Sulfate–Surfactant Micelle Mesostructure as an Effective Remover of Selenite Ion
Authors: Takada Hitoshi , Watanabe Yoshimasa , Iwamoto Masakazu 
Published: December 2003

Abstract
Selenite ion in an aqueous solution could be effectively trapped in the zirconium sulfate–surfactant micelle mesostructure (ZS). The reaction proceeded through anion exchange between HSO4− in ZS and HSeO3−. The maximum sorption capacity of ZS for HSeO3− was 2.47 mmol g−1 at 303 K.
Crystal Structure of Pyrazolato-bridged Copper(I) Polynuclear Complexes
Authors: Fujisawa Kiyoshi , Ishikawa Yoko , Miyashita Yoshitaro , Okamoto Ken-ichi 
Published: December 2003

Abstract
We prepared a series of copper(I) polynuclear complexes bridged by three different alkyl substituted pyrazolate anions. From X-ray analysis, these differences reflected their molecular structures. These structural changes also reflected some properties in their IR, far-IR, UV–vis, and NMR spectra.
Quenching of Peroxynitrite by Lycopene in Vitro
Authors: Yokota Tadashi , Ohtake Teturou , Ishikawa Hajime , Inakuma Takahiro , Ishiguro Yukio , Terao Junji , Nagao Akihiko , Etoh Hideo 
Published: December 2003

Abstract
We investigated in vitro the reactivity of lycopene toward peroxynitrite and identified the reaction products after scavenging peroxynitrite. On the basis of these studies, we propose a mechanism for peroxynitrite scavenging action of lycopene.
The Reduction of Broken Appointments in General Dental Practice
Authors: Patel Piyush , Forbes Michael , Gibson John 
Published: December 2003

Purpose of study Accumulation of time lost because of broken appointments in general dental practice can lead to an inefficiently-run practice and may also lead to reduced financial income. This study assessed the reasons for patients failing to attend and analysed the effect of two simple interventions in reducing the numbers of broken appointments. Basic procedures This study audited the causes of broken appointments in a Glasgow dental practice over a four-month period and, in a second four-month period, analysed the effect of using two new methods of patient information in reducing the number of broken appointments in two target groups of the practice population. Main findings The majority of patients failing to attend for dental treatment were unemployed. Simple changes to recall letters and appointment cards significantly reduced the rates of failed appointments in patients attending the practice. Principal conclusions Simple modification to existing practice systems (recall letters and appointment cards) led to a statistically significant reduction in the number of broken appointments.
An Analysis of the Qualitative Factors which Influence
Authors: Gray Margaret M , Bradnock Gillian , Gray Helen L 
Published: December 2003

Introduction and method The qualitative data volunteered as responses to open questions in a self-administered questionnaire study we re analysed to identify the psychological factors influencing young people's behaviour in relation to orthodontic care and to gain an understanding of the psychological factors which influence adolescents’ acceptance of orthodontic care. The study was conducted in all Walsall and Dudley secondary schools. Results and discussion The responses of the young people who were in year 10 of education with an average age of 15.0 years demonstrated the importance of personal constructs, peer group and media influences, parental influences, conflicting messages, teasing, symptom perception, appearance and self-image, and interpersonal relationships in determining whether or not young people either seek and accept or reject orthodontic treatment. Conclusion The study concluded that it is essential that clinicians involve patients fully and honestly in discussions concerning their orthodontic therapy in order to enable them to make a considered consent.
An Overview of Reasons for the Placement and Replacement of Restorations
Authors: Deligeorgi Vassiliki , Mjör Ivar A , Wilson Nairn HF 
Published: December 2003

Aim Surveys on reasons for the placement and replacement of restorations have been conducted in various countries. The purpose of this paper is to bring together and review the data of 10 such surveys with similar methodology. Method The studies reviewed are all based on the protocol described by Mjör in 1981. Results The surveys reviewed provide data on the reasons for the placement and replacement of a total of 32,777 restorations. Notwithstanding differences between countries, different groups of practitioners and minor variations in methodology, the data included in the selected surveys indicate that everyday clinical practice in Scandinavia, UK and USA during the 1980s and 1990s has involved more replacement than initial restorations, with the ratio of initial to replacement restorations ranging from 1:1.1 to 1:2.4 for amalgam and 1:1.1 to 1:3.8 for composite materials. Primary caries has been consistently found to be the principal reason for the provision of initial restorations of amalgam and composite. The principal reason for the replacement of restorations of amalgam and composite has remained secondary caries as diagnosed clinically. Material failures (marginal degradation, discoloration, bulk fracture and loss of anatomic form) accounted for the replacement of more restorations of composite than amalgam. Recent surveys have reported secondary caries as the principal cause of failure of restorations of glass-ionomer cements and related materials. Conclusions The clinical diagnoses of caries may continue to be found to account for the placement and replacement of most intracoronal restorations. Surveys of the type reviewed provide valuable insight into patterns of provision of dental care and highlight research priorities in relation to direct restorations.
Evaluation of ovotransferrin-matrix metal-affinity metalloprotein chromatography for Pu(IV) separations
Authors: Myers W. K. , Ruggiero C. E. , Reilly S. D. , Neu M. P. 
Published: December 2003

Abstract
Metal-Affinity metalloprotein chromatography has been suggested to have potential for selectively removing actinides from solution. To evaluate this potential, characterization of Pu(IV) and Fe(III) binding to an ovotransferrin-Sepharose™ 4B matrix, with oxalate and carbonate synergistic anions, was performed. Metal binding capacity was determined for metal concentrations ranging from 2×10-6 to 1×10-3M Fe(III) and 2.9×10-5 to 2.6×10-4M Pu(IV), where both metals were added as a solution of 10:1 nitrilotriacetic acid:metal. Metal binding capacity was also determined over the pH range 3.0 to 9.2. The metal binding properties of the immobilized ovotransferrin were found to differ from those reported for free-protein studies. Distribution coefficients were low: for metal solution concentrations of 0.02, 0.04, 0.10, and 0.20mM, coefficients were 540, 180, 23, and 12mL/g for Fe(III) and 20, 12, 7.2, and 6.0mL/g for Pu(IV), respectively. The capacity of the material was less dependent on pH than expected, varying by only two μmoles metal/g matrix for both Fe(III) and Pu(IV) over the pH range of 4.2 to 9.5. This study illustrates limitations of metalloprotein chromatography for Pu(IV) separation.
Role of ligand basicity and stereochemistry in the extraction of plutonium(IV) isoxazolonates
Authors: Mohapatra P. K. , Manchanda V. K. 
Published: December 2003

Abstract
The extraction behaviour of plutonium (IV) was investigated from nitric acid and perchloric acid using 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) as well as a mixture of HPBI and tri-n-octyl phosphine oxide (TOPO) in xylene. Studies on the binary extraction system Pu(IV)-HPBI indicated extraction of species of the type Pu(PBI)4. In the presence of TOPO, while species of the type Pu(PBI)3(ClO4)·(TOPO) and Pu(PBI)4·TOPO were co-extracted from perchloric acid medium, a mixture of Pu(PBI)2(NO3)2·2TOPO, Pu(PBI)3(NO3)·(TOPO) and Pu(PBI)4·TOPO were co-extracted from nitric acid medium. In addition to the electronic factors, steric factors were found to play a significant role during the formation of binary/ternary/quaternary complexes. The steric hindrance due to the unusual conformation of the isoxazolone led to lowering of the equilibrium constants for both the binary and ternary extraction systems. Possible steric factor influences are explained with the help of molecular modelling.
Sorption kinetics and impact of temperature, ionic strength and colloid concentration on the adsorption of plutonium-239 by inorganic colloids
Authors: Lu Ningping , Reimus Paul W. , Parker Gary R. , Conca James L. , Triay Inès R. 
Published: December 2003

AbstractPlutonium (Pu) is one of the primary actinides of concern for long-term disposal and storage of nuclear waste. Strong sorption of Pu onto colloids of iron oxide, clay, and silica could result in colloid-facilitated transport of this actinide in groundwater systems. However, fundamental data on Pu sorption to colloids is sparse, resulting in large uncertainties in long-term predictions of colloid-facilitated Pu transport. This sparseness of data and the potential to significantly reduce uncertainties in predictive models served as a motivation for this study. The authors investigated the sorption and desorption behaviors of239Pu(V) on three types of inorganic colloids (hematite, montmorillonite and silica), with adsorption being measured as a function of temperature, ionic strength and colloid concentration for each colloid. Natural ground water collected from Well-13 near Yucca Mountain, Nevada, and synthetic ground water (SYN.J-13) were used in the experiments. The results indicated that the adsorption of239Pu(V) onto hematite colloids was faster and had a higher partition coefficient (Kp, ml g-1) than onto montmorillonite or silica colloids in both J-13 and SYN.J-13 waters. Temperature did not significantly influence the adsorption of239Pu(V) onto hematite and silica colloids, but the adsorption of239Pu(V) onto montmorillonite colloids increased significantly with increasing temperature. While ionic strength did not significantly influence the adsorption of239Pu(V) onto hematite colloids, an increase in ionic strength decreased the adsorption of239Pu onto montmorillonite and silica colloids. Adsorption of239Pu(V) per unit mass of colloid was much higher at low colloid concentrations than at high colloid concentrations. Desorption of239Pu from239Pu-loaded colloids was considerably slower than the adsorption process.
Sorption of Np(V) by synthetic hydroxyapatite
Authors: Moore Robert C. , Holt Kathleen , Zhao Hongting , Hasan Ahmed , Awwad Nasser , Gasser Mona , Sanchez Charles 
Published: December 2003

AbstractThe sorption of Np(V) to synthetic hydroxyapatite was determined in batch experiments in a 0.1M NaClO4solution. The hydroxyapatite used was of high purity as determined by SEM, EDS, XRD, FT-IR and ICP-MS analysis. Results from kinetic experiments with an initial Np(V) concentration of 1×10-7to 1×10-6M indicate the sorption process is relatively fast with more than 90 of the Np(V) being sorbed in approximately 3 hours. Equilibrium experiments performed over the pH range of 6 to 11 indicated sorption is strongly pH dependent with distribution coefficients,Kdvalues (mL/g), increasing from 123L/mole at pH 6 to 69200L/mole at pH 8.5.Kdvalues are observed to decrease as pH further increases. Data points over a range of Np(V) concentrations were collected at pH 8 and fitted to the Langmuir isotherm model for simple adsorption. The Langmuir equation gave an excellent representation of the data. Langmuir parameters were determined to beCa=0.032mole/mole andK=1.22×106L/mole, indicating the high affinity of hydroxyapatite for Np(V) adsorption.
Humic colloid mediated transport of tetravalent actinides and technetium
Authors: Artinger Robert , Buckau Gunnar , Zeh P. , Geraedts K. , Vancluysen J. , Maes A. , Kim Jae-Il 
Published: December 2003

AbstractThe humic colloid mediated transport of tetravalent actinide and technetium ions is discussed. Numerous published and new results are used from comparable experimental systems and conditions. The results originate from investigations on two humic rich Gorleben groundwater/sediment systems under near-natural conditions. The conditioning time between groundwater and radionuclides vary from few minutes to four years. The migration time (residence time in the column) is varied from four hours to three days. The concentration of radionuclides added is varied between about 10-12and 10-4mol/L. Humic colloids in natural groundwater contain trace metal ions in varying concentrations. In addition to studying the behavior of radionuclides added to the groundwater in the laboratory, the dissociation behavior of these natural tetravalent trace metal ions is studied by scavenging dissociating ions with a cation exchanger. The results show a kinetic behavior of the trace metal ion interaction as frequently reported in the literature,i.e.with increasing contact time, slow dissociation modes are progressively populated resulting in an enhanced radionuclide transport. The strong dependency of the radionuclide transport on the radionuclide concentration shows that humic colloid mediated transport may be overestimated if radionuclide concentrations used in laboratory studies are too high. Dissociation of the natural inventory of humic associated tetravalent trace metal ions proceeds with a kinetics comparable to the radionuclides added. This, however, is only observed for a small portion of the inventory and extrapolation beyond the observation range is not permissible. Therefore, the key question for application to predictive modeling of the mobility of tetravalent radionuclides in natural groundwater is if the behavior of the natural trace element inventory is applicable or the behavior of radionuclides added in laboratory studies.
Study of hafnium complexes by time differential perturbed angular correlation technique
Authors: Das S. K. , Saha S. K. 
Published: December 2003

Abstract
Complexation of hafnium with two ligands viz. diethylene triamine pentaacetic acid (DTPA) and its dimethyl ester derivative (DMDTPA) has been studied by using time differential perturbed angular correlation (TDPAC) technique. Nuclear quadrupole coupling constant (ν
Q), asymmetry of the EFG (η) and the frequency distribution (δ) for these complexes have been obtained. Square antiprism structures have been suggested for these complexes using these parameters. A systematic trend of the ν
Q has been observed in these and other hafnium complexes with similar ligands and has been explained in terms of the electronegativity of the donor atoms in the ligands.
Sr3Ga4O9 – a strontium gallate with a new type of tetrahedral layer structure
Authors: Kahlenberg V. , Parise J. B. 
Published: December 2003

Abstract
Synthetic strontium gallate Sr3Ga4O9 is triclinic, space group P1̅ (a = 6.7490(9)Å, b = 8.0494(12)Å, c = 9.7295(15)Å, α = 85.01(2)º, β = 72.71(2)º, γ = 74.24(2)º, V = 485.7(3)Å3, Z = 2, D
calc = 4.69 g·cm-3). The structure was solved by direct methods using 2656 unique reflections and refined to a residual of R1 = 0.042 (146 parameters). The compound belongs to the group of tetrahedral single layer structures. Individual sheets are parallel to (100), thus producing a prominent cleavage. The stepped layers can be described as being built by the condensation of six tetrahedra-wide bands. The bands in turn consist of two open branched dreier single chains connected via common corners and they contain tertiary and quaternary tetrahedra Q3 and Q4 in the ratio 1:1. The stacking of the layers containing four-, six- and eight-membered rings results in a three-dimensional structure in which the strontium cations reside in the voids between the layers and are coordinated by six to seven oxygen neighbors.
Crystal structure, magnetic properties and band gap measurements of NdTe2-

x
(x=0.11(1))
Authors: Stöwe K. 
Published: December 2003

Abstract
As for the homologous La, Ce and Pr compounds, the X-ray diffraction single-crystal structure analysis of NdTe2 (prepared by chemical vapor transport reactions in the presence of traces of iodine) also revealed superstructure reflections, but indicating a (3x4x2) supercell of the basic anti-Fe2As type instead of a (2x2x1) supercell as for LaTe2 or a (2x2x2) supercell as for CeTe2 and PrTe2. NdTe2 crystallizes orthorhombic with the lattice parameters a = 1328.9(1) pm, b = 1767.7(2) pm and c = 1806.9(2) pm (Z = 48) in space group Amm2. Analysis by ICP-OES as well as density measurements revealed a nonstoichiometric composition (ICP-OES: NdTe1.90(2); X-ray diffraction: NdTe1.89(1)), whereas the other compounds of this series, LaTe2, CeTe2 and PrTe2, showed no defects in the tellurium sublattice. Compared to the basic anti-Fe2As structure type, the differences of this new structure lie entirely in the topology of the polyanionic square nets. Due to the presence of distortions and defects, the sheets may be regarded as revealing several different canonical entities, which are assumed by emphasizing interatomic distances below a certain limit (305 pm). These entities are [Te2] dimers, square-shaped [Te8] rings and, to a small amount, even more complicated fragments. All in all the distortions lead to a semiconducting compound (band gap ΔE = 0.14 eV), which obeys the Curie-Weiss law and reveals even at T = 2 K no indications for a magnetic ordering.
Electron crystallography of the polymethylene chain. 5. Three-dimensional structure of a Fischer-Tropsch wax
Authors: Dorset Douglas L. 
Published: December 2003

Abstract
The crystal structure of a Fischer-Tropsch wax, Shell Callista 158, has bee determined in three dimensions from electron diffractio intensity data. Although there is an orthorhombic layer arrangement with apparent dimensions, a = 7.42, b = 4.96, c = 94.50 Å, true lamellae cannot form, due to a ‘nematocrystalline’ arrangement of very long chain components,generating a continuous chain direction through adjacent chain layer clusters. The structure is actually a superlattice of the Pnam cell observed for high molecular weight polyethylene.
Mortality from cardiovascular disease in relation to magnetic field exposure: Findings from a study of UK electricity generation and transmission workers, 1973–1997
Authors: Sorahan Tom , Nichols Linda 
Published: December 2003

AbstractBackgroundExperimental and epidemiological studies have indicated that magnetic field exposure might influence heart rate variability and consequent risks of arrhythmia related deaths.MethodsThe mortality experience of a cohort of 83,997 employees of the former Central Electricity Generating Board (CEGB) of England and Wales was investigated for the period 1973–1997. Cohort members were employed for at least 6 months from 1973 to 1982. Computerized work histories were available for 79,972 study subjects for the period 1971–1993. Detailed calculations had been performed by others to enable a novel assessment to be made of exposures to magnetic fields. Two analytical approaches were used, indirect standardization (n = 83,997) and Poisson regression (n = 79,972).ResultsBased on serial mortality rates for England and Wales, deaths from four categories of cardiovascular disease were below expectation: arrhythmia‐related disease (ICD‐9 426‐7), observed (obs) 32, expected (exp) 43.5, standardized mortality ratio (SMR) 74; acute myocardial infarction (ICD‐9 410), obs 3,320, exp 3878.3, SMR 86; atherosclerosis (ICD‐9 440), obs 25, exp 39.2, SMR 64; chronic/sub‐acute coronary disease (ICD‐9 411‐414), obs 1,552, exp 2021.7, SMR 77). No statistically significant trends were shown for risks of any of these four disease groupings to increase either with lifetime cumulative exposure to magnetic fields or with such exposures received in the most recent 5 years.ConclusionsThere are no discernible excess risks of mortality from cardiovascular diseases as a consequence of occupational exposure to magnetic fields in UK electricity generation and transmission workers. Am. J. Ind. Med. 45:93–102, 2004. © 2003 Wiley‐Liss, Inc.
Relationships between certain individual characteristics and occupational injuries for various jobs in the construction industry: A case‐control study
Authors: Chau Nearkasen , Mur Jean‐Marie , Benamghar Lahoucine , Siegfried Christian , Dangelzer Jean‐Louis , Français Martine , Jacquin Régis , Sourdot Alain 
Published: December 2003

AbstractBackgroundThere is little published about the role of individual characteristics in occupational injuries. Construction workers have a high rate of injury; we assessed 11 personal characteristics in this professional sector.MethodsA case‐control study was conducted on 880 male workers who had had at least one occupational injury during a 2‐year period and 880 controls. A questionnaire was administered by an occupational physician. Statistical analysis was made via logistic regression method.ResultsYoung age (<30 years), sleep disorders and current smoker influenced all the injuries combined. Sleep disorders and young age were common risk factors for several jobs. Physical disabilities and no sporting activity had a role in masons, and 5 years or less in present job in plumbers and electricians only. Sleep disorders influenced both the injuries with and without hospitalization; young age, current smoker, and physical disability influenced those without hospitalization only.ConclusionsYoung age, sleep disorders, smoking, disabilities, sporting activity, and experience influenced the occupational injuries. The risk for each worker depended on his job. Occupational physicians could inform the workers of these risks and encourage them to take remedial action. Am. J. Ind. Med. 45:84–92, 2004. © 2003 Wiley‐Liss, Inc.