bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of mining on railway infrastructure and developments in their control
Authors: Grainger M. A. 
Published: July 2007

Until recent years the possibility of running high speed passenger traffic through an area of mining subsidence was considered unrealistic. However, accurate predictions of surface movement, in conjunction with the use of rail force transducers to monitor the changes in the stress free condition of the continuous-welded rail, have enabled line speed to be maintained in situations where, previously, severe speed restrictions would have been imposed. These developments, together with computer designed preventive and remedial works schemes, ontrack machinery control and precautionary measures incorporated into structures, have allowed mining subsidence to be safely accommodated on the British Railways Board's railway network. Some of the developments referred to could have wider applications, outside the railway undertaking, in the protection and maintenance of large buildings, motorway bridges, gas, electricity and water pipelines, etc. There are 75 locations on the railway that are currently being affected by mining subsidence associated with underground operations, involving 32 miles of railway track and 215 structures. In addition, there are more than 200 surface excavations working in close proximity to the Board's network.
Hydrocortisone Affects the Expression of Matrix Metalloproteinases (MMP‐1, ‐2, ‐3, ‐7, and ‐11) and Tissue Inhibitor of Matrix Metalloproteinases (TIMP‐1) in Human Gingival Fibroblasts
Authors: Cury Patricia R. , Araújo Vera C. , Canavez Flavio , Furuse Cristiane , Araújo Ney S. 
Published: July 2007

Background: There is a positive correlation between the course of periodontal disease and psychosocial stress status. Stress leads to activation of the hypothalamic‐pituitary‐adrenal axis, resulting in increased cortisol release. The present study evaluates the effect of two different hydrocortisone concentrations on mRNA expression of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs) in cultured, human gingival fibroblasts.Methods: Gingival fibroblasts were stimulated with 10−7 or 10−9 M hydrocortisone for 24 hours; untreated cells served as controls. Alterations in the expression of MMP‐1, ‐2, ‐3, ‐7, ‐11 and TIMP‐1 and ‐2 were evaluated using real‐time polymerase chain reaction and Western blotting. β‐actin mRNA expression was used as a reference to normalize gene expression.Results: Although the higher hydrocortisone concentration upregulated MMP‐1, ‐2, ‐7, ‐11, and TIMP‐1 (P <0.0‐) expression, the lower concentration induced downregulation or diminished upregulation. The lower hydrocortisone concentration induced a 23‐fold increase in MMP‐3 gene expression, whereas the higher concentration induced less upregulation; however, protein expression was regulated similarly by both hydrocortisone concentrations. The effect of hydrocortisone on TIMP‐2 expression was not significant (P >0.0‐).Conclusions: Hydrocortisone produced a dose‐dependent regulation of MMP and TIMP expression. The higher hydrocortisone concentration significantly upregulated expression of MMP‐1, ‐2, ‐7, and ‐11 and TIMP‐1 in human gingival fibroblasts, which may constitute a mechanism underlying the increased periodontal breakdown associated with psychosocial stress status.
The Long‐Term Effect of a Mouthrinse Containing Essential Oils on Dental Plaque and Gingivitis: A Systematic Review
Authors: Stoeken Judith E. , Paraskevas Spiros , van der Weijden Godefridus A. 
Published: July 2007

Background: The purpose of this study was to review the literature on the effects of a mouthrinse containing essential oils (EO) on plaque and parameters of gingival inflammation.Methods: The MEDLINE and Cochrane Central Register of Controlled Trials were searched up to and including December 2006 to identify appropriate studies. The primary outcome measure was gingivitis. Secondary parameters were plaque and, when reported, staining.Results: Independent screening of titles and abstracts of 566 papers resulted in 11 publications that met the criteria of eligibility. In all studies, EO was used as an adjunct to regular daily toothbrushing. A statistically significant reduction in overall gingivitis was noted compared to the control (weighted mean difference [WMD]: −0.32, 95% confidence interval [CI]: −0.46 to −0.19, P <0.00001; test for heterogeneity: P <0.00001, I2 = 96.7%). For interproximal sites the use of the test mouthrinse resulted in significantly more gingivitis reduction compared to control mouthrinse (WMD: −0.29, 95% CI: −0.48 to −0.11, P = 0.002; test for heterogeneity: P <0.00001, I2 = 95.18%), whereas no differences were observed compared to dental floss. With respect to plaque scores, EO produced significant overall reductions in plaque (WMD: −0.83, 95% CI: −1.13 to −0.53, P <0.00001; test for heterogeneity: P <0.00001, I2 = 96.1%). Separate analysis for interproximal areas revealed that EO resulted in more pronounced plaque drops compared to the control mouthrinse (WMD: −1.02, 95% CI: −1.44 to −0.60, P <0.00001; test for heterogeneity: P <0.00001, I2 = 96.1%) or the use of floss (WMD: −0.75, 95% CI: −1.15 to −0.363, P <0.0002; test for heterogeneity: P <0.0002, I2 = 93.0%). Most studies agreed that EO did not produce more staining than the control products.Conclusion: When used as an adjunct to unsupervised oral hygiene, EO provides an additional benefit with regard to plaque and gingivitis reduction as compared to a placebo or control.
Effect of 17β‐Estradiol and Alendronate on the Removal Torque of Osseointegrated Titanium Implants in Ovariectomized Rats
Authors: Giro Gabriela , Sakakura Celso Eduardo , Gonçalves Daniela , Pereira Rosa M.R. , Marcantonio Elcio , Orrico Silvana R.P. 
Published: July 2007

Background: This study investigated the influence of estrogen deficiency and its treatment with estrogen and alendronate on the removal torque of osseointegrated titanium implants.Methods: Fifty‐eight female Wistar rats received a titanium implant in the tibia metaphysis. After 60 days, which was needed for implant osseointegration, the animals were randomly divided into five groups: control (CTLE; N = 10), sham surgery (SHAM; N = 12), ovariectomy (OVX; N = 12), ovariectomy followed by hormone replacement (EST; N = 12), and ovariectomy followed by treatment with alendronate (ALE; N = 12). The CTLE group was sacrificed to confirm osseointegration, whereas the remaining groups were submitted to sham surgery or ovariectomy according to their designations. After 90 days, these animals were also sacrificed. Densitometry of femur and lumbar vertebrae was performed by dual‐energy x‐ray absorptiometry (DXA) to confirm systemic impairment of the animals. All implants were subjected to removal torque.Results: Densitometric analysis of the femur and lumbar vertebrae confirmed a systemic impairment of the animals, disclosing lower values of bone mineral density for OVX. Analysis of the removal torque of the implants showed statistically lower values (P <0.05) for the OVX group in relation to the other groups. However, the group treated with alendronate (ALE group) presented significantly higher torque values compared to the others.Conclusion: According to this study, estrogen deficiency was observed to have a negative influence on the removal torque of osseointegrated implants, whereas treatment with alendronate increased the torque needed to remove the implants.
Juvenile Spongiotic Gingivitis
Authors: Darling Mark R. , Daley Tom D. , Wilson Aze , Wysocki George P. 
Published: July 2007

Background: This article recognizes the microscopic diagnosis of acute spongiotic mucositis as an analog to acute spongiotic dermatitis of the skin and defines a specific clinicopathological entity “juvenile spongiotic gingivitis” within this microscopic spectrum.Methods: Twenty‐four patients, usually juveniles, with patches of bright red, often slightly thickened, painless, and persistent lesions of the attached gingiva, which may or may not involve the marginal gingiva, were identified by clinical and microscopic features. Immunohistochemical studies for cytokeratins 5/6 and 19, estrogen receptors, and progesterone receptors were completed on 10 of these cases. A comparison to puberty gingivitis, which occurs in the same age group, was done.Results: Microscopically, the epithelium exhibited hyperplasia, significant spongiosis, loss of keratinization, and a neutrophilic infiltrate, sometimes with microabscess formation, whereas the underlying connective tissue exhibited an acute on chronic inflammatory infiltrate. Full‐thickness epithelial immunostaining for cytokeratins 5/6 and 19 was found, whereas no reactivity was seen for estrogen receptors or progesterone receptors in the specimens.Conclusions: Juvenile spongiotic gingivitis differs from puberty gingivitis by not needing to show continuity with plaque‐related marginal gingivitis, by a lack of response to hygiene procedures, by an occasional occurrence at ages not related to puberty, and by the absence of sex hormone receptors investigated immunohistochemically in 10 of the cases. We propose juvenile spongiotic gingivitis as a distinct clinicopathological entity.
Miscibility of blends of bisphenol‐A‐polycarbonate and poly(styrene‐co‐acrylonitrile‐co‐hydroxystyrene) terpolymer
Authors: Li Guangxian , Mong Shiyun , Jiang Sujun , Ragupathy L. , Cowie J. M. G. , Ferguson R. , Arrighi V. 
Published: July 2007

AbstractThe miscibility of blends of bisphenol‐A‐polycarbonate (BAPC) with the terpolymer poly(hydroxystyrene‐co‐acrylonitrile‐co‐styrene) (OHS‐AN‐S) and the copolymer poly(hydroxystyrene‐co‐acrylonitrile) (OHS‐AN) was investigated. BAPC was found to be miscible with terpolymers incorporating 25–80 mol % hydroxystyrene. The introduction of the acrylonitrile monomer (AN) into poly(styrene‐co‐hydroxystyrene) (PSHS) produces a wider “miscibility window” with BAPC compared with that of blends of BAPC with PSHS i.e. a miscible blend is obtained at relatively lower levels of hydroxyl groups in the terpolymer. However, the miscibility range in terpolymer/BAPC blends is affected by the amount of AN monomer incorporated into the terpolymer. This is probably a consequence of the influence of the AN monomer on the closer spatial correlation between the terpolymer and BAPC chains. BAPC is also found to be miscible with the OHS‐AN copolymer within the composition range 12–50 AN mol % in the copolymer. A triangular phase diagram for binary blends of terpolymer/homopolymer (AxByCz/D) is suggested, to determine the miscible region of the terpolymer compositions in the blends. A model used for predicting the miscibility of binary blends consisting of a homopolymer and a terpolymer was also proposed on the basis of the mean‐field theory, and tested with the experimental results obtained in this work. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Effect of low‐load reinforcing nanofillers on rheological behavior and physical properties of ionic elastomers based on XNBR and MgO
Authors: Rodríguez A. , Ibarra L. , Mora I. 
Published: July 2007

AbstractThe influence of low load reinforcing fillers in carboxylated nitrile rubber (XNBR), crosslinked with magnesium oxide, has been studied. The nanofillers utilized were carbon black, precipitated silica, natural clay, and synthetic silica. The latter filler was obtained by acid lixiviation of a natural magnesium silicate. The rheological behavior of the samples was study by means of capillary (consistency index) and rotational (Mooney viscosity) flows. Through these analyses, higher viscosities, and lower flow indexes were observed for the filled samples. The acid character of silica and clay leads to an increase in vulcanization rates, measured by the cure rate index (CRI) and referring it to the unfilled compound. Moreover, the fillers dilute the ionic microphases formed during the vulcanization process of the XNBR. Since these microphases behave as reinforcing sites, a decrease in tear and abrasion properties takes place. However, the reinforcing effect of the fillers leads to higher values of stress at constant strains. Finally, the variation of glass and ionic transition temperatures with filler addition was analyzed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Decision heuristics as predictors of public choice
Authors: Wang X. T. 
Published: July 2007

AbstractTwo studies examined cognitive and affect‐based heuristics as predictors of public choice. Participants, recruited before the 2004 Presidential Election, identified the issues that would determine their voting decision and provided ratings of importance and Likelihood of Success for these issues (decision cues) regarding each presidential candidate. Both well‐known and new heuristics were evaluated for descriptive fit between predicted and actual voting choices and overall predictive accuracy regarding who the winner of the sample would be. In Study 1, the performance of cue‐weight free simple heuristics, particularly those based on frequency counts, matched or outperformed that of normative Franklin's rule that used both cue values and cue weights. In Study 2, the affect (admiration and contempt)‐based heuristics performed even better. The Take‐The‐Best Emotion heuristic performed as well as the affect heuristics utilizing multiple social emotions. These findings highlight the utility of event frequency‐based and interpersonal affect‐based heuristics in predicting public choice under uncertainty. Copyright © 2007 John Wiley & Sons, Ltd.
Biohorizons
Authors: Moni Roger W. , Moni Karen B. , Poronnik Philip , Lluka Lesley J. 
Published: July 2007

AbstractWe detail the design, implementation and evaluation of an eConference entitled “Biohorizons”, using a presage‐process‐product model to describe the development of an eLearning community. Biohorizons was a summative learning and assessment task aiming to introduce large classes of first‐year Human Biology students to the practices of professional scientists. It was implemented in semester 1 for students enrolled in Pharmacy and Human Movement Studies degree programs, and in semester 2, for Science students. Pairs of students selected a topic of interest in Human Biology, registered into on‐line clusters, then developed and wrote a short scientific paper and accompanying PowerPoint presentation. They then individually participated in an online Discussion. All three tasks were assessed using standards‐referenced assessment rubrics. Learning was supported by eTutors, working in asynchronous mode. Biohorizons was evaluated by analyzing student achievement data, surveys and focus group interviews. Most students were able to achieve high academic standards (global mean scores for semester 1, 85–96%; semester 2, 81–90%). Student evaluations support: 1) the successful integration of eLearning into large classes of Human Biology, 2) the engagement of first‐year students through collaborative learning, and 3) the fostering of learning through challenging assessment relevant to the core practices of professional scientists.
Structure and Reactivity of the Metal Centers of Ribonucleotide Reductases
Authors: Mulliez Etienne , Fontecave Marc 
Published: July 2007

AbstractThe activation of the three classes of ribonucleotide reductases as free radical enzymes is reviewed. Class I uses O2 and a diferric μ‐oxo center to generate a stable tyrosyl protein radical. Class II operates with adensoyl cobalamin as the precursor of a putative transient thiyl protein glycyl radical by the concerted forms an O2‐sensitive protein glycyl radical by the concerted action of an iron–sulfur cluster and (S)‐adensoyl methionine.
Metallacyclodisiladiazanes of Titanium and zirconium; Synthesis, Structure and Polymerization Studies
Authors: Jäger Felix , Roesky Herbert W. , Dora Hendrik , Shak Syed , Noltemeyer Mathias , Schmidt Hans‐Geory 
Published: July 2007

AbstractA series of metallacyclodisiladiazanes has been prepared. Lithiated (SiMe2NHtBu)2 (1) reacts with TiCl4 · 2 THF to give (SiMe2NtBu)2TiCl (4). Methylation or fluorination of 4 leads to (SiMe2NtBu)2TiMe2 (8) and (SiMe2MtBu)2TiF2 (9), respectively. The reaction of ZrCl4 · 2 THF with lithiated 1 or [SiMe2NH(4‐FC6J4)]2 (2) yields (SiMe2NtBu)2ZrCl2 (5) and [SiMe2N(4‐FC6H4)]ZrCl2 · THF (7), respectively. The lithiated ligand [SiMe2NH(2,6‐iPr2C6H3)]2 (3) reacts with noncoordinated ZrCl4 to give [SiMe2N(2,6‐iPr2C6H3)]2ZrCl2 (6). X‐ray structural analysis of 9 showed it to be a fluorine‐bridged dimer in the solid state. Compounds 4, 6, 8 and 9 were found to be catalysts for the polymerization of ethylene.
Formation of the Digallium Compound [(C5C6)2N3](R)Ga–Ga(R)[N3(C6H5)2] with Two Bis(trimethylsilyl)methyl Groups and Two Terminal Chelating Diphenyltriazenido Ligands
Authors: Uhl Werner , Hann Ingo , Wartchow Rudofl 
Published: July 2007

AbstractTetrakis[bis(trimethylsilyl)methyl]digallane (4) 1 reacts with 1,3‐diphenyltriazene to yield two compounds, which were both characterized by a crystal structure determination. The gallium–gallium bond is retained in the yellow derivate [(H5C6)2N3](R)Ga–Ga(R)[N3(C6H5)2 2 [R = CH(SiMe3)2], which is formed by a ligand exchange reaction and shows two terminal chelating triazenido ligands besides two bis(trimethylsilyl)methyl groups; the GaGa bond length is 245.79(6) pm. The second product is the orange dialkyl(diphenyltriazenido)gallium derivative R2Ga[N3(C6H5)2] 3, where the triazene has reacted as an oxidant by the cleavage of the GaGa bond and probably by release of elemental hydrogen.
Synthesis and Properties of Me2Ge‐Bridged Arenes
Authors: König Burkhard , Rödel Martin 
Published: July 2007

AbstractLinear and cyclic oligomers of Me2Ge‐bridged π‐systems have been obtained by the reaction of carbo‐ and heterocyclic anions and dianions with Me2GeCl2. The spectroscopic properties of the new compounds are compared with analogous carbon‐ and Me2Si‐bridged π‐systems.
Crown Thioether Chemistry: Novel Silver(I) Complexes of 1,3‐Dithiole‐Annelated 1,4,7‐Trithiacyclononane
Authors: Wagner Michael , Drutkowski Ulrkie , Jörchel Peter , Hoyer Eberhand , Olk Ruth‐Maria , Kempe Rhett 
Published: July 2007

AbstractThe coordination chemistry of two crown thioethers 2,5,8,10,12‐pentathiabicyclo[7.3.0]dodeca‐1)9)‐ene‐11‐thione (L) and ‐11‐one (L') with Ag1 has been investigated by structural methods. Both thioethers act as tridentate ligands coordinating the silver ion in a trigonal fashion. In the case L, the 11‐ thione sulfur is coordinated additionally by another silver ion, to yield a polymeric chain with a distorted‐tetrahedral geometry about the metal ion. Despite differing only in its carbonyl chalcogen, L' forms six‐coordinated, monomeric complexes.
Oxozirconium Methacrylate Clusters: Zr6(OH)4O4(OMc)12 and Zr4O2(OMc)12 (OMc = Methacrylate)
Authors: Kickelbick Guido , Schubert Ulrich 
Published: July 2007

AbstractThe crystalline oxozirconium methacrylate clusters Zr6(O‐H)4O4(OMc)12 and Zr4O2(OMc)12 were obtained by reaction of Zr(OnPr)4 with an excess of methacrylic acid and analysed by X‐ray diffraction. The oxide and hydroxide groups are in a μ3‐ bridging mode in both structures, and the methacrylate ligands are chelating or bridging. The zirconium atoms in Zr6(OH)4O4(OMc)12 form an octahedron the cluster having crystalographic C3v symmetry. Each metal atom is square‐antiprismatically coordinated by eight oxygen atoms. In Zr4O2(OMc)12, the zirconium atoms have a distorted butterfly arrangement; their coordination geometry is square‐antiprismatically coordinated by eight oxygen atomes. In Zr4O2)OMc)12, the zirconium atoms have a distorted butterfly arrangement; their coordination geometry is square‐antiprismatic or capped octahedral.
The Biological and Medicinal Chemistry of Bismuth
Authors: Sun Hongzhe , Li Hougyan , Sadler Peter J. 
Published: July 2007

AbstractBismuth compounds have been widely used in medicine for more than 200 years, and new bismuth‐containing drugs are now being developed. However the biological chemistry of bismuth is poorly understood. We review here methods for the study of bismuth compounds, and use of Bi(III) in antiulcer, antibacterial, anti‐HIV and radiotherapeutic agents is described. The chemistry of Bi(III) carboxylates and aminocarboxylates is dominated by intermolecular interactions which lead to polymeric structures. Bi(III) exhibits a highly variable coordination number and coordination geometry, and alkoxide ligands can induce a strong stereochemical “lone‐pair effect”. Bi(III) can bind to both Zn(II) sites (e.g. metallothionein) and Fe(III) sites (e.g. transferrin) in proteins. Further work is needed to understand the relationship between the structures and dynamics of bismuth compounds and their bioactivity.
Fully Chlorinated N‐Silyl Amides of Titanium and Tungsten — Crystal Structure of Cl3SiNW(Cl3)N(SiCl3)2
Authors: Schwarze Bernd , Milius Wolfgang , Schnick Wolfgang 
Published: July 2007

AbstractThe reaction of hexachlorodisilazanyllithium (Cl3Si)2NLi (1), with TiCl4 leads selectively to the novel fully chlorinated amides (Cl3Si)2NTiCl3 (2) or [(Cl3Si)2N]2 TiCl2 (3), respectively, depending on the molar ratio of the starting materials. The analogous reaction of 1 with WCl6 yielded the amide imide Cl3SiNW(Cl3)N(SiCl3)2 (5) by elimination of SiCl4. The relative amounts of the starting materials had no effect on the formation of 5. 14/15N‐ and 29Si‐NMR data on the starting materials and products show significantly different effects, when compared with those of analogous N‐trimethylsilyl derivatives, due to the lower energy of the electrons in the NSi and NM ß bonds. The crystal structure of 5 (triclinic, space group P1) was determined by X‐ray structure analysis.
Organophosphorus Compounds, 118. Reactions of 1‐Chloro‐1H‐phosphirenes with Nucleophiles
Authors: Heydt Heinrich , Ehle Michael , Haber Steffen , Hoffmann Jürgen , Wagner Oliver , Göller Andreas , Clark Timothy , Regitz Manfred 
Published: July 2007

AbstractThe halogen atoms in the 1‐chloro‐1H‐phosphirenes, 5a–c, are easily substituted on reaction with organolithium and Grignard reagents, 14a–p, with formation of the corresponding O‐, N‐, C‐, Si‐, and Ge‐substituted 1H‐phosphirenes, 15a–t. C1/H exchange reactions also occur on reaction with lithium metal hydrides (5a → 17). Furthermore, substitution reactions are also realized with the alkali metal borates, 18a–g (→19a–g); the same is true for reactions with trimethylsilyl cyanide and azide (→22a–d). Some of the substitution products have been characterized in the form of their metal complexes, 16, 23, 24, and 25.
Compounds of Germanium and Tin, 2l. A Tetraaryldigermene with a Short Germanium‐Germanium Double Bond and a Nearly Planar Environment of Both Germanium Atoms
Authors: Weidenbruch Manfred , Stürmann Martin , Kilian Hartmut , Pohl Siegfried , Saak Wolfgang 
Published: July 2007

AbstractTreatment of GeCl2 · dioxane with the Grignard reagent RMgBr (R=2‐tBu‐4,5,6‐Me3C6H) furnishes the tetraaryldigermene R2GeGeR2 (8). X‐ray structure‐analysis of 8 reveals a short GeGe double bond, a nearly planar environment of both germanium atoms and extremely widened CGeC angles of 128°. In solution, 8 dissociates into two germylene molecules R2Ge, which can be trapped with oxygen or by [4+1] cycloaddition reactions with 1,4‐dihetero‐1,3‐dienes. A similar cycloadduct of a stannylene wa obtained by thermolysis of (R′2Sn)3 (R′=2,4,6‐iPr3C6H2), in the presence of a 1,4‐diazabutadiene and characterized by an X‐ray structure‐analysis.