bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of the master settlement agreement on cigarette consumption
Authors: Sloan Frank A. , Trogdon Justin G. 
Published: August 2004

AbstractIn 1998, 46 states and the four major tobacco companies signed the Master Settlement Agreement (MSA), which stipulated that the tobacco companies pay states $206 billion over 25 years and take steps to reduce youth smoking. The remaining states settled separately. We sought to determine the effect of the settlements on demand for cigarettes. Using a nationwide sample from 1990 to 2002, we estimated a model of the decision to smoke cigarettes. The settlements affected smoking primarily through price increases for cigarettes, although there was evidence that other policy instruments influenced smoking rates for younger smokers. By 2002, the settlements had reduced overall smoking rates by 13 percent for ages 18 to 20 and older than 65 and 5 percent for ages 21 to 64. © 2004 by the Association for Public Policy Analysis and Management.
Federal policy mandating safer cigarettes: A hypothetical simulation of the anticipated population health gains or losses
Authors: Tengs Tammy O. , Ahmad Sajjad , Moore Rebecca , Gage Eric 
Published: August 2004

AbstractIf manufacturing a safer cigarette is technically possible—an open question—then mandating that tobacco manufacturers improve the safety of cigarettes would likely have both positive and negative implications for the nation's health. On the one hand, removing toxins may reduce the incidence of smoking‐related diseases and premature mortality in smokers. On the other hand, smokers might be less inclined to quit, those who have quit might resume the habit, and youth who have never smoked will have one less reason to avoid tobacco use. To assess the expected population health impacts of a legislative or regulatory mandate, we created the Tobacco Policy Model, a system dynamics computer simulation model. The model relies on secondary data and simulates the U.S. population over time spans as long as 50 years. Our simulation results reveal that even if requiring cigarettes to be safer makes smoking more attractive and increases tobacco use, a net gain in population health is still possible. © 2004 by the Association for Public Policy Analysis and Management.
Controlled release of indole‐3‐butyric acid (IBA)—based on polymeric matrix prepared by ionizing radiation
Authors: El‐Rehim H. A. Abd , Hegazy El‐Sayed. A. , El‐Mohdy H. L. Abd 
Published: August 2004

AbstractPolyacrylamide/polyethylene oxide (PAAm/PEO) controlled release matrices were designed to obtain a better control over the concentration of indole‐3‐butyric acid (IBA). PAAm/PEO incorporated IBA was prepared by exposing aqueous solutions of PEO, PAAm, crosslinking agent N,N′‐methylene‐bisacrylamide, and IBA mixtures to electron beam irradiation. PAAm/PEO copolymer structural property relationships that affect its controlled release behavior were determined. Analysis of the results obtained indicated that it is possible to optimize IBA controlled release by adjusting the dimensions and crosslinking degree of the copolymer as well as the concentration of the incorporated IBA. The crosslinking degree of the copolymer can be controlled by governing the irradiation dose, polymer blend composition and/or the amount of crosslinking agent. IBA release rates have been investigated as a function of environmental conditions, such as the changes in pH and temperature to determine the factors, which mostly contribute to the release of IBA. The effect of PAAm/PEO–IBA matrix on the average height of corn (Zea mayz) plant was investigated. The results obtained, revealed that PAAm/PEO‐IBA systems have a capability to deliver IBA slowly and continuously. As a result, the development of root and vegetative systems of Zea mayz plant was greatly promoted. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of drug release from thermo‐ and pH‐sensitive poly(N‐isopropylacrylamide/itaconic acid) copolymeric hydrogels
Authors: Taşdelen B. , Kayaman‐Apohan N. , Güven O. , Baysal B. M. 
Published: August 2004

AbstractN‐Isopropylacrylamide/itaconic acid copolymeric hydrogels were prepared by irradiation of the ternary mixtures of N‐isopropylacrylamide/itaconic acid/water by γ‐rays at ambient temperature. The dependence of swelling properties and phase transitions on the comonomer concentration and temperature were investigated. The hydrogels showed both temperature and pH responses. The effect of comonomer concentration on the uptake and release behavior of the hydrogels was studied. Methylene blue (MB) was used as a model drug for the investigation of drug uptake and release behavior of the hydrogels. The release studies showed that the basic parameters affecting the drug release behavior of the hydrogels were pH and temperature of the solution. Copyright © 2004 John Wiley & Sons, Ltd.
Role played by the head size of some non‐ionic surfactants on their adsorption onto montmorillonite clay
Authors: Shalaby Magda N. 
Published: August 2004

AbstractSorption behavior of polyoxethylene(n)monooleate series [Ol(EO)n] onto montmorillonite clay was studied at 25°C to investigate the influence of the surfactant's head size on the sorption process. All the tested surfactants exhibited L‐shaped isotherms that means a strong interaction between the adsorbent and the adsorbate. Also, all the obtained isotherms ended with a drastic increase in the isotherm slope at nearly constant equilibrium concentration. This abrupt increase reflected the fairly high affinity of the tested surfactants to the clay surface at high bulk concentration region. The maximum amount adsorbed at the plateau region, Γmax, was calculated according to the Langmuir adsorption theory and followed the order: Ol(EO)14 > Ol(EO)20 < Ol(EO)40 < Ol(EO)80. In case of short ethylene oxide (EO) chain, Γmax decreased with the increase in the chain length; but a reverse result was obtained in case of surfactants with longer EO chain length (20 to 80 units). The free energy of adsorption, ΔG°ad, had negative values indicating the spontaneous adsorption of surfactant molecules onto clay. The values of ΔG°ad increased with increasing EO units from 14 to 20 units and decreased with further elongation in the EO chain from 20 to 80 units. Copyright © 2004 John Wiley & Sons, Ltd.
Quantum chemical calculation of structures and NMR chemical shifts of substituted buta‐1,3‐dienyl‐2‐cations
Authors: Siehl Hans‐Ullrich , Brixner Sandra 
Published: August 2004

AbstractA computational study of 13C NMR chemical shifts of a series of α‐vinyl substituted vinyl cations (1,3‐dienyl‐2‐cations) 1–6 is presented. The sensitivity of the predicted isotropic shifts to electron correlation, basis set and geometry effects is explored. Comparison with experimental 13C NMR chemical shifts shows that second‐order Møller–Plesset perturbation theory calculations [GIAO‐MP2/tzp//MP2/6–31G(d,p)] perform adequately (deviation ≈ 3–4 ppm) for all carbons of cations 1–6, except for carbons in 6 involved in cyclopropyl hyperconjugation, which give some larger deviations (≈ 6–9 ppm). The Hartree–Fock self‐consistent field (GIAO‐HF/tzp) approximation as well as GIAO‐DFT‐methods together with hybrid functionals (B3LYP) give unsatisfactory results and cannot be relied upon to predict the sequence of signals in the 13C NMR spectra of these type of carbocations. Copyright © 2004 John Wiley & Sons, Ltd.
The impact of the herbicide glyphosate on leaf litter invertebrates within Bitou bush, Chrysanthemoides monilifera ssp rotundata, infestations
Authors: Lindsay Elizabeth A , French Kris 
Published: August 2004

AbstractChrysanthemoides monilifera ssp rotundata (L) T Norl (Bitou bush) is a serious environmental weed along the southeast coast of Australia. The herbicide glyphosate is commonly used to control C monilifera on the New South Wales coastline, but there have been few studies examining the effects of this herbicide on invertebrate communities in the field, especially on sand dunes. Control and impact sites were selected in coastal hind dunes heavily infested with C monilifera, and the impact sites were sprayed with a 1:100 v/v dilution of glyphosate‐isopropyl 360 g AE litre−1 SL (Roundup Biactive). Leaf litter invertebrates were sampled before spraying and after spraying by collecting fixed areas of leaf litter in both the control and impact sites. Samples were sorted for particular invertebrates involved in leaf litter decomposition and some of their predators. This study did not identify any significant direct or indirect effects on leaf litter invertebrate abundance or community composition in the four months following herbicide application. The litter invertebrate assemblages were highly variable on a small spatial scale, with abiotic factors more strongly regulating leaf litter invertebrate numbers than glyphosate application. These results conflict with previous studies, indicating that the detrimental indirect effects herbicide application has on non‐target litter invertebrates may depend upon the application rate, the vegetation community and structure and post‐spray weather. Copyright © 2004 Society of Chemical Industry
Electronic transition moment with spin‐orbit coupling of the molecular ion KRb+
Authors: Korek M. , Younes G. 
Published: August 2004

AbstractBy using the electronic wave functions obtained from an ab initio calculation, including the spin‐orbit coupling, the electronic transition moments have been investigated for two bound states of symmetry Ω = 1/2 and Ω = 3/2 of the molecular ion KRb+. Based on a canonical functions approach for the determination of the vibrational wave functions, the matrix elements have been calculated for the bound states considered for v = 0, 10, 20 with v′‐ v = 0, 1, 2, …, 6; by using the same canonical approach, the eigenvalues and abscissas of the corresponding turning points (rmin and rmax) have been investigated for these states that obtained from a theoretical ab initio calculation up to v = 105. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Continuum eigen‐functions of 1‐D time‐independent Schrödinger equation solved by symplectic algorithm
Authors: Qi Yue‐Ying , Liu Xue‐Shen , Ding Pei‐Zhu 
Published: August 2004

AbstractWe present the symplectic algorithm for solving the continuum eigen‐functions of 1‐dimensional (1D) time‐independent Schrödinger equation, which keeps Wronskian conservation of linearly independent continuum eigen‐functions. This symplectic algorithm has been applied to the computation of the linearly independent continuum eigen‐functions of both 1D soft‐coulomb potential and Pöshl–Teller short‐range potential as well as the radial continuum eigen‐functions of hydrogen atom. The numerical results using the symplectic algorithm are in agreement with the existing theories. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Quantum electronic transport in a configuration interaction basis
Authors: Delaney P. , Greer J. C. 
Published: August 2004

AbstractAn overview of a many‐body approach to calculation of electronic transport in molecular systems is given. The physics required to describe electronic transport through a molecule at the many‐body level, without relying on commonly made assumptions such as the Landauer formalism or linear response theory, is discussed. Physically, our method relies on the incorporation of scattering boundary conditions into a many‐body wavefunction and application of the maximum entropy principle to the transport region. Mathematically, this simple physical model translates into a constrained nonlinear optimization problem. A strategy for solving the constrained optimization problem is given. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Single nucleotide polymorphism analysis in the human phosphatase PTPrj gene using matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry
Authors: Powell Ned , Dudley Ed , Morishita Mariko , Bogdanova Tetyana , Tronko Mykola , Thomas Gerry 
Published: August 2004

AbstractData derived from analysis of single nucleotide polymorphisms (SNPs) are being applied in many diverse fields, from medical studies of disease mechanisms and individual drug response, to population genetics for tracking migration and mixing of ancestral groups and also in forensic science for the identification of human remains and identification of individuals from bodily samples. All these applications have in common the need to generate data for multiple loci from large numbers of samples. Matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOFMS) is a promising platform for the generation of such data and we present a simple, flexible and robust technique for SNP determination. We demonstrate these features by typing two SNPs (Q276P and R326Q) in the human phosphatase gene PTPrj, which has been implicated in the aetiology of colon, lung, breast and thyroid cancers. A nucleotide depletion primer extension assay using no commercial kits or dideoxyNTPs was used to genotype a panel of DNAs derived from thyroid cancer patients and normal volunteers. The results obtained were in perfect agreement with those generated via restriction fragment length polymorphism analysis. No significant association was noted between possession of either allelic variant and a disease state, but the technique was validated as simple, flexible and appropriate for application in this context. Furthermore, it was highly cost‐effective and required minimal optimisation, rendering it ideal for this type of pilot study. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction
Authors: Unger Matthias , Frank Andreas 
Published: August 2004

AbstractHere we describe a liquid chromatography/mass spectrometry (LC/MS) method with automated online extraction (LC/LC/MS) to simultaneously determine the in vitro inhibitory potency of herbal extracts on six major human drug‐metabolising cytochrome P450 enzymes. Substrates were incubated with a commercially available mixture of CYP1A2/2C8/2C9/2C19/2D6 and 3A4 from baculovirus‐infected insect cells and the resulting metabolites were quantified with LC/LC/MS using electrospray ionisation in the selected ion monitoring mode. Consistent inhibitory activities were obtained for known inhibitors and plant extracts using the enzyme/substrate cocktail and the individual enzymes/substrates. Popular herbal remedies including devil's claw root (Harpagophytum procumbens), feverfew herb (Tanacetum parthenium), fo‐ti root (Polygonum multiflorum), kava‐kava root (Piper methysticum), peppermint oil (Mentha piperita), eucalyptus oil (Eucalyptus globulus), red clover blossom (Trifolium pratense) and grapefruit juice (GJ; Citrus paradisi) could be identified as inhibitors of the applied CYP enzymes with IC50 values between 20 and 1000 μg/mL. Copyright © 2004 John Wiley & Sons, Ltd.
Identification of some new clemastine metabolites in dog, horse, and human urine with liquid chromatography/tandem mass spectrometry
Authors: Tevell Annica , Bondesson Ulf , Törneke Karolina , Hedeland Mikael 
Published: August 2004

AbstractThe metabolism of clemastine was studied in dogs, horses, and humans after a single dose of Tavegyl®. The urine collected was extracted by solid‐phase extraction or hydrolyzed with β‐glucuronidase and then extracted by liquid‐liquid extraction, prior to analysis for unchanged drug and phase I and II metabolites by liquid chromatography/tandem mass spectrometry. The metabolites were identified by their molecular mass and interpretation of the product ion spectra, since no standard substances were available. Unchanged drug was recovered in urine samples from dogs and humans, but not from horses. In dogs and humans, the phase I metabolite, norclemastine, was identified, and clemastine metabolites with one and two additional oxygens were found in all three species. In horses and dogs monohydroxylation on one of the aromatic rings or the adjacent methyl group was favored while, in humans, the additional oxygen was positioned on either the aromatic or the aliphatic part of the structure, and the aliphatic reaction seemed to result in at least three isomers. In the metabolites with two additional oxygens, both the oxygens were found on the aliphatic fragment in humans and dogs, whereas they were situated on the aromatic part of the structure in horses. In human patients, glucuronidated monohydroxyclemastine was recovered, and in urine from horses both mono‐ and dihydroxyclemastine glucuronides were identified, while phase II metabolites could not be recovered from the dog urine. Clemastine metabolism in dogs and horses has, to our knowledge, not been studied before, and new metabolites from humans are presented in this article. Thus, the metabolites described in the present work have not been previously reported in the literature. Copyright © 2004 John Wiley & Sons, Ltd.
Anticipation‐based partial redundancy elimination for static single assignment form
Authors: VanDrunen Thomas , Hosking Antony L. 
Published: August 2004

AbstractPartial redundancy elimination (PRE) is a program transformation that identifies and eliminates expressions that are redundant on at least one (but not necessarily all) execution paths of a program without increasing any path length. Chow, Kennedy and co‐workers devised an algorithm (SSAPRE) for performing partial redundancy elimination on intermediate representations in static single assignment (SSA) form. The practicality of that algorithm is limited by the following concerns: (1) it makes assumptions about the namespace that are stronger than those of SSA form and that may not be valid if other optimizations have already been performed on the program; (2) if redundancies occur in nested expressions, the algorithm may expose but not eliminate them (requiring a second pass of the algorithm); (3) it misses cases covered by the state of the art in PRE; and (4) it is difficult to understand and implement. We present an algorithm (A‐SSAPRE) structurally similar to SSAPRE that uses anticipation rather than availability; this algorithm is simpler than SSAPRE, covers more cases, eliminates nested redundancies on a single pass, and makes no assumptions about the namespace. Copyright © 2004 John Wiley & Sons, Ltd.
Comparative chemistry of isolable divalent compounds of silicon, germanium, and tin
Authors: Kira Mitsuo , Ishida Shintaro , Iwamoto Takeaki 
Published: August 2004

AbstractRecent studies of the synthesis, structures, spectroscopic properties, and reactions of a series of isolable metallylenes (R2E:, E = Si (1), Ge (2), and Sn (3); R2 = 1,1,4,4‐tetrakis(trimethylsilyl)butane‐1,4‐diyl) are summarized. Because these group‐14 metallylenes bear the same helmet‐like ligand, a straightforward discussion of the element‐dependence of the intrinsic properties of the group‐14 element divalent compounds is possible. All these metallylenes were monomeric both in solution and in the solid state, indicating the effective steric protection by the ligand against dimerization. A small σπ conjugation between CSi(substituent) σ orbitals and the vacant npz orbitals of divalent atoms in R2E: exists and the extent decreases in the order E = Si > Ge > Sn, as evidenced by UV‐vis and NMR spectroscopies and X‐ray crystallography. However, the extent of the σπ conjugation in metallylenes 1–3 was much smaller than the electron‐donating effects of neighboring nitrogen atoms in known stable cyclic diamino‐substituted metallylenes, and hence metallylenes 1–3 are regarded as the least electronically perturbed. Comparative studies of the unique reactions among these metallylenes are also discussed. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 243–253; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20019
Structural Study of Alkaline 1‐Phenyl‐1H‐1, 2, 3, 4‐tetrazole‐5‐thiolate Salts: An Example of Periodicity in Alkaline Cations
Authors: Hernández‐Arganis Michelle , Toscano Rubén A. , Moya‐Cabrera Mónica , García‐Montalvo Verónica , Cea‐Olivares Raymundo 
Published: August 2004

AbstractThe alkaline 1‐phenyl‐1H‐1, 2, 3, 4‐tetrazole‐5‐thiolate salts, M[C6H5N4CS] (M = Li (1), Na (2), K (3), Rb (4) and Cs (5)) were obtained and characterized by means of mass spectrometry (FAB+) and NMR (1H; 13C) spectroscopy. The structures of Na (2), K (3), Rb (4) and Cs (5) compounds were determined by X‐ray diffraction methods. The ligand shows a rich variety of coordination patterns with the alkaline cations. The formation of a four‐membered ring MSCN in the compounds with heavier alkali cations (K, Rb and Cs) is shown. In all the cations the coordination number around it increases with the ionic radius. Compounds with Cs+ and Rb+ exhibited the formation of Cs‐C and Rb‐C interactions with the phenyl group.
Synthesis, Crystal Structure, IR Spectra and Thermal Analysis of Na[Ag(sac)2] (sac = saccharinate)
Authors: Yilmaz Veysel T. , Hamamci Sevim , Thöne Carsten 
Published: August 2004

AbstractThe reaction of silver nitrate with sodium saccharinate (Na[sac]) in the presence of 2‐pyridinepropanol in aqueous solution yields the title complex, Na[Ag(sac)2]. The compound crystallizes in the triclinic space group $P {\bar 1}$ [a = 8.0481(6), b = 9.0587(6), c = 11.1642(8) Å; α = 100.064(3), β = 99.917(3) and γ = 92.367(3)°, Z = 2]. The structure consists of Na+ and [Ag(sac)2]‐ ions, in which each silver(I) ion is doubly bridged by the sac ligands, exhibiting a distorted 'T' shaped AgN2O coordination arrangement with one long [Ag‐Osulfonyl = 2.6390(10) Å] and two shorter bonds [Ag‐N = 2.1405(11) and 2.1570(11) Å]. The coordination around silver(I) is trigonal planar and the N‐Ag‐N bond angle is 158.99(5)°. The Na+ ion is five‐coordinate with two carbonyl and three sulfonyl O atoms of the adjacent sac ligands and acts as a bridge between [Ag(sac)2]‐ units, resulting in a three‐dimensional network. The i.r. spectra and thermal decomposition behaviour of Na[Ag(sac)2] are discussed in detail.
Zur Reaktion der Meldrumsäure mit Schwefeldichlorid ‐ Synthese und Eigenschaften eines ungewöhnlichen 1,3‐Dithietans [1]
Authors: Kuhn Norbert , Al‐Sheikh Ahmed , Maichle‐Mößmer Cäcilia , Steimann Manfred , Ströbele Markus 
Published: August 2004

AbstractDas 1,3‐Dithietan {MelS}2 (8) wird durch Umsetzung der Meldrumsäure MelH2 (1, Mel = C6H6O4) und Schwefeldichlorid in guter Ausbeute erhalten. 8 reagiert mit den Nukleophilen PPh3 und 2,3‐Dihydro‐1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐yliden (12, Im)zu den zwitterionischen Verbindungen Mel‐S‐PPh3 (11) und Mel‐S‐Im (13).Mit wäss. Ammoniak wird das dianionische Disulfid (NH4)2[Mel‐S‐S‐Mel] (14) erhalten. Die Kristalllstrukturen von 8, 11, und 14 werden diskutiert.