bluuebunny/crossref_metadata_2025_split huggingface dataset:
Renal Function and Periodontal Disease in Elderly Japanese
Authors: Yoshihara Akihiro , Deguchi Tomoya , Hanada Nobuhiro , Miyazaki Hideo 
Published: July 2007

Background: Chronic renal failure involves a slow, progressive loss of renal function over months or years. It is possible that periodontal disease and chronic kidney disease might share common risk factors. This study investigated whether a link exists between periodontal disease and chronic renal function in community‐dwelling elderly subjects.Methods: A total of 14‐ study subjects, all 77 years of age, participated in this study. A periodontal examination was carried out by trained dentists. Urine was collected over 24 hours, and blood was taken on the morning of the dental exam. The volume of creatinine per 24 hours (Cre_U) and volume of urine per 24 hours were used as urinary markers of kidney function; serum creatinine levels (Cre_S) were used as a blood marker of kidney function. Creatinine clearance per 24 hours was calculated as Cre_U/Cre_S. In addition, biochemical parameters of bone turnover were measured: urinary deoxypyridinoline (U‐DPD) as a bone resorption marker and serum osteocalcin (S‐OC) as a bone formation marker. Multiple regression analysis was used to evaluate the relationship between the percentage of periodontal sites with ≥6‐mm clinical attachment level (% ≥6‐mm CAL) and renal function, as well as the relationship between % ≥6‐mm CAL and bone metabolism. The % ≥6‐mm CAL was used as the dependent variable. The number of remaining teeth, smoking habit, gender, use of interdental brushes or dental floss, volume of urine per 24 hours, and creatinine clearance per 24 hours were independent variables in the first test. In addition, the number of remaining teeth, smoking habits, gender, use of interdental brushes or dental floss, U‐DPD, and S‐OC were independent variables in the second test.Results: Multiple regression analysis showed that creatinine clearance per 24 hours and S‐OC were significantly associated with % ≥6‐mm CAL per person. The standardized coefficients were 0.26 (P = 0.015) and −0.27 (P = 0.006), respectively.Conclusions: The % ≥6‐mm CAL was significantly associated with renal function and bone metabolism markers. This study suggests that the increased incidence of chronic renal failure that occurs with age might increase the probability of severe periodontal disease in community‐dwelling elderly subjects.
RANKL Inhibition Through Osteoprotegerin Blocks Bone Loss in Experimental Periodontitis
Authors: Jin Qiming , Cirelli Joni A. , Park Chan Ho , Sugai James V. , Taba Mario , Kostenuik Paul J. , Giannobile William V. 
Published: July 2007

Background: Prevention of alveolar bone destruction is a clinical challenge in periodontal disease treatment. The receptor activator of nuclear factor‐kappa B ligand (RANKL) inhibitor osteoprotegerin (OPG) inhibits osteoclastogenesis and suppresses bone resorption.Methods: To study the effects of RANKL inhibition on alveolar bone loss, an experimental ligature‐induced model of periodontitis was used. A total of 32 rats were administered human OPG‐Fc fusion protein (10 mg/kg) or vehicle by subcutaneous delivery twice weekly for 6 weeks. Negative or positive controls received no treatment or disease through vehicle delivery, respectively. Biopsies were harvested after 3 and 6 weeks, and mandibulae were evaluated by microcomputed tomography (μCT) and histology. Serum levels of human OPG‐Fc and tartrate‐resistant acid phosphatase‐‐b (TRAP‐5b) were measured throughout the study by enzyme‐linked immunosorbent assay (ELISA). Statistical analyses included analysis of variance (ANOVA) and Tukey tests.Results: Human OPG‐Fc was detected in the sera of OPG‐Fc–treated animals by 3 days and throughout the study. Serum TRAP‐‐b was sharply decreased by OPG‐Fc treatment soon after OPG‐Fc delivery and remained low for the observation period. Significant preservation of alveolar bone volume was observed among OPG‐Fc–treated animals compared to the controls at weeks 3 and 6 (P <0.05). Descriptive histology revealed that OPG‐Fc significantly suppressed osteoclast surface area at the alveolar crest.Conclusion: Systemic delivery of OPG‐Fc inhibits alveolar bone resorption in experimental periodontitis, suggesting that RANKL inhibition may represent an important therapeutic strategy for the prevention of progressive alveolar bone loss.
Morphotypes, polymorphism and peristome in the species of the genus Holcophylloceras Spath, 1927. Hypothesis of the dimorphism in the species Holcophylloceras zignodianum (d’Orbigny, 1848)
Authors: Joly Bernard , Fonters Bruno 
Published: July 2007

Abstract
The genus Holcophylloceras Spath, 1927, including especially a majority of Jurassic species and some rare lower Cretaceous species, is easy to distinguish from other genera with constrictions such as Calliphylloceras Spath, 1927 or Sowerbyceras Parona & Bonarelli, 1895. In the genus Holcophylloceras the constrictions are clearly sigmoid or falcoid. Both characteristics can be observed on the same specimen. In the genus Calliphylloceras the constrictions are falcoid while they are sigmoid on Sowerbyceras. Actually these genera are closely allied and they represent evolutionary stages in a lineage characterized by more or less growth alteration. The lineage origin probably exists among Liassic Phylloceras. The genus Calliphylloceras shows a small growth alteration, while it is maximal in Sowerbyceras and it is intermediate in Holcophylloceras.
This note shows that species of the genus Holcophylloceras are also characterized by three morphotypes: prae-caucasica, caucasica and nausikaae; these morphotypes do not characterize any particular species. The first and the second morphotypes could be an adaptation to live in deep waters. They probably give more solidity to the shell. The initial object of this note was to study again all the morphotypes of the genus Holcophylloceras with a new material collected in the oxfordian “Terres noires”.
The authors of this note have studied the relations between the morphotypes prae-caucasica, caucasica and the peristome of Holcophylloceras. Does the peristome study permit to envisage the existence of dimorphic couples? (sexual dimorphism?). The result has been disappointing. On the other hand many microconchs and macroconchs have been identified. In particular with zignodianum-mediterraneum it is possible to identify the “male form” (zignodianum = microconch) and the “female form” (mediterraneum = macroconch) which confirms the intuition of Beznosov [1958] by an other approach to the problem. Many authors asked them if they had to separate the forms with sigmoid constrictions from those with falcoid constrictions. It seems now, there is no doubt and both species zignodianum-mediterraneum have to be joined in the same taxon zignodianum which has priority over mediterraneum.
Last result of this study is the justification of the genus Holcophylloceras created by Spath.
Molecular structure and shear rheology of long chain branched polypropylene formed by light cross‐linking of a linear precursor with 1,3‐benzenedisulfonyl azide
Authors: Jørgensen Jens Kjær , Redford Keith , Ommundsen Espen , Stori Aage 
Published: July 2007

AbstractLinear isotactic metallocene based polypropylene (Mw = 125,000 g/mol, Mn = 61,000 g/mol) was lightly crosslinked by small amounts of 1,3‐benzenedisulfonyl azide to form long chain branches (LCB). Crosslinking was carried out by reactive extrusion at 200°C in a small scale extruder. At the processing temperature, the two azide groups decompose to nitrenes that work as crosslinkers for PP. The crosslinking reaction occurs primarily by insertion of singlet nitrenes into CH bonds. 1,3‐benzenedisulfonyl azide concentrations of, respectively, 518, 806, 1029, and 2038 ppm were used. SEC revealed formation of a high molecular weight LCB fraction. No degradation was observed by SEC. The introduction of LCB gave rise to rheological behavior typical of LCB as increased zero shear viscosity, accompanied by increased shear thinning, increased flow activation energy and a phase angle plateau. However, the rheological impact and crosslinking efficiency observed were limited compared to earlier studies on PE. Possible reasons for this are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Enantioselective Catalysis, XIII. Preparative and Structural Chemistry of Chiral 3‐(Diphenylphosphanyl)‐pyrrolidiens and Their Palladium(II) Complexes
Authors: Nagel Ulrich , Nedden Hans Günter 
Published: July 2007

AbstractThe preparation of both enantiomers of 3‐diphenylphosphanulpyrrolidiine (2) and several N‐substituted derivatives together with two PdIi complexes of this ligand is reported. Form L‐malic acid and L‐hydroxyproline both enantiomers of 3‐hydroxypyrrolidine are prepared without any problems due to epimerization. KPPh2 in the presence of LiCl is shown to be the most effective reagent for the synthesis of 2. The reported X‐ray structure determination sof Pdl2 complexes show a rather rigid bicyclic hetero‐norbornane skeleton. The flexibility of the other parts of the molecules is obvious in several polymorphs revealed by this method. This polymorphism is additionally investigated by a 31P‐CP‐MAS study. From solution 1‐, 13C‐ and 31P‐NMR studies it is concluded that the bicyclic hetero‐norbornane skeleton is retained in solution.
Atropisomeric Binaphthalene‐Core Phosphacyclic Derivatives in Coordination Chemistry and Homogeneous Catalysis
Authors: Gladiali Serafino , Fabbri Davide 
Published: July 2007

AbstractBinaphthophospholes and binaphthophosphepines have recently been synthesized. These are the first representatives of a new class of chiral ligands that include within the same structure an endocyclic phosphorus donor, a local C2 symmetry and an axially chiral core. In this review we discuss the synthesis, chemical behaviour and first applications in asymmetric catalysis of these novel derivatives.
Well‐Defined Metallodendrimers by Site‐Specific Complexation
Authors: Bosman Anton W. , Schenning Albert P. H. J. , Janssen René A. J. , Meijer E. W. 
Published: July 2007

AbstractStrong multiple complexation of transition metal ions, Cu(II), Zn(II) and Ni(II) with different generations of well‐defined poly(propylene imine) dendrimers as multi(tridentate) ligands has been used to construct nanoscopic assemblies of defined structure and size incorporating a distinct number of metal ions from 2 up to 32.
Synthesis of Germatranyl Derivatives of Esters of Carboxylic Acids via Organometallic (Si, Ge, Sn) Reagents
Authors: Zaitseva Galina S. , Livantsova Ljudmila I. , Nasim Mohammed , Karlov Sergei S. , Churakov Andrei V. , Howard Judith A. K. , Avtomonov Evgeni V. , Lorbert Jörg 
Published: July 2007

AbstractTrialkylstannyl esters of tris(2‐hydroxyalkyl)amines, N(CH2CHROSnAlk3)3 (9‐11 (R = H, Me; Alk = Et, Bu), react with X3GeC(R1)(R2)COOR3 (12–17) (X  Cl or Br; R1, R2=H, Me, Ph, SiMe3, COOEt; R3=Me, Et) to give esters of α‐germatranylcarboxylic acids, N(CH2CHRO)3GeC(R1)(R2)‐COOR3 (1–8), in high yields. The synthesis of esters 12–17 is reported. Esters of α‐germatranyldiphenylacetic acid 24 and 25 can be obtained by treatment of diphenylketene with Et3SnOMe to give in situ Et3SnC(Ph2)COOMe (23), followed by reaction with GeCl4 to give in situ Cl3GeC(Ph2)COOMe (22 and further reactions with 9 or 11, respectively. Reduction of germatrane 6 with LiAlH4 in diethyl ether leads to cleavage of the germanium‐carbon bond with subsequent formation of (2‐hydroxyethyl)trimethylsilane. The crystal structures of 3, 6 and 7 are reported. 1‐Acyloxygermatranes 26 and 27 are obtained by treatment of 1‐methoxygermatrane (28) with diphenyl‐ and dichloroacetic acid, respectively.
Sulfur Compounds, 199. Novel Titanocene Thiolato Complexes and Their Application in Preparing New Sulfur‐Containing Heterocycles
Authors: Steudel Ralf , Kustos Monika , Münchow Vera , Westphal Ursula 
Published: July 2007

AbstractTreatment of Cp2Ti(CO)2 (3) with the di‐ and polysulfanes 1,2,4‐(CH2)2S3, C4S6 (9), C,7H10S3 (11), 1,2,4,6‐(CH2)3S4 (16), C6H10S6(19), and S6 affords the titanocene chelate complexes Cp2TiS3(CH2)2 (8), (Cp2Ti)2C4S6 (10), Cp2TiS3C7H10 (13), Cp2TiS2C7H10 (14), Cp2TiS4(CH2)3 (17), Cp,2TiS6C6H6H10 (20), and Cp2TiS8 (23). 14 is also obtained from Cp2TiCl2 (1) and the geminal dithiol of norbornene. The analogous reaction with the dithiol of dicyclopentadiene yields Cp2TiS2C10H12 (15). In ligand transfer reactions, 8 reacts with SCl2 to give 1,2,3,5‐tetrathiane (25), 10 provides 9 on reaction with Cl2, 13 when treated with S2Cl2 affords C7H10S5 (12), 15 reacts with S2Cl2Cl2 to give C10H12S4. 17 and SCl2 yield 1,2,3,5,7‐pentathiepane (18), 20 is converted to C6H10S7 (22) on reaction with SCl2, and 23 yields S10 and 1,2,‐C6H4(SCl)2, respectively. With phosgene, thiophosgene, and thionyl chloride, compound 15 yields the corresponding dithiocarbonate 26, the trithiocarbonate 27 and the trisulfane 2‐oxide 28. The structure of 27 was determined by X‐ray crystallography.
Electroactive Protecting Groups and Reaction Units, 6. – Titanium Enolate Radical Cations in Solution: Generation, Characterization, and Their Reactions
Authors: Schmittel Michael , Söllner Rolf 
Published: July 2007

AbstractFor the first time titanium enolate radical cations were characterized in cyclic voltammetry experiments. Preparative one‐electron oxidation of titanium enolates1‐3led to the formation of benzofuransB1‐B3through mesolytic Ti‐O bond fragmentation to α‐carbonyl radical and a cationic titanocene(IV) species. With 1+·, the kinetics of the Ti‐O bond cleavage was investigated by fast scan cyclic voltammetry providing a first‐order rate constant k1=850 ± 50 s−1in acetonitrile at room temperature. The titanium enolate radical cations1+·, 3+·, 4+·and 5%%were characterized by EPR spectroscopy, qualifying these species as electrophilic radicals. This feature can be exploited in CC bond formation reactions such as the formal dimerization of6to 2,3‐dimethyl‐1,4‐diphenylbuta‐1,4‐dioneD6, which takes place on stage of the radical cation 6+·.
Organometallic Molybdenum(V) Complexes with Promary Phosphane Ligands — Syntheses, Spectroscopic Properties, and Crystal Structures of [Cp′MoCl4(PH2R)] (R=2,4,6‐Pri3C6H2, Cyclohexyl, Cp′=C5H4Me)
Authors: Felsberg Reinhard , Blsurock Steffen , Jelonek Svea , Gelbrich Thomas , Kirmse Reinhard , Voigt Andreas , Hey‐Hawkins Evamarie 
Published: July 2007

Abstract[Cp′MoCl4(CH3CN) (Cp′=C5H4Me) react with 2,4,6‐triisopropylphenylphosphane or cyclohexylphosphane to give the phosphane complexes [Cp′MoCl4(PH2R)] [R=2,4,6‐Pri3C6H2 (1)]. 1 and 2, were characterized spectroscopically (IR, MS) and by crystal structure determinations. EPR investigations in liquid and frozen solution confirmed the presence of Mo(V) species and the data were used to analyze the spin‐density distribution in the first coordination sphere.
Aminotroponimines as Ligands for Yttrium and Lanthanide Complexes
Authors: Roesky Peter W. 
Published: July 2007

AbstractThe reaction of N‐isopropyl‐2‐(isopropylamino)troponimine, [(i‐Pr)2ATI]H, with KH in THF affords [(i‐Pr)2ATI]K. This is a useful starting material for the preparation of the mono‐, bis‐ and tris‐substituted compounds [[i‐Pr)2ATI]YCl2‐(THF)2}2, [(i‐Pr)2ATI2Y[O(2,6,t‐Bu2C6H3)] and [(i‐Pr)2‐ATI]3Ln (Ln = Y, La, Sm), which can be obtained from ([i‐Pr)2ATI]K and LnX3 and LnX3 (X = Cl, I), or Y[O(2,6‐t‐BuC6H3)]3. All compounds have been characterized by spectroscopic methods. The monosubstituted yttrium complex {[(i‐Pr)2ATI]YCl2(THF)2}2 has also been investigated by single crystal X‐ray diffraction.
Bis[2‐(oxazolinyl)phenolato]oxovanadium(IV) Complexes: Syntheses, Crystal Structures and Catalyses
Authors: Boln Carsten , Luong Thi Kim Khanh , Harms Klaus 
Published: July 2007

AbstractThe syntheses and X‐ray crystal structures of two chiral bis[2‐(oxazolinyl)phenolato]‐oxovanadium(IV) complexes are reported. Their catalytic activity in oxidative transformations and C‐C bond‐forming reactions has been investigated.
Gold Coordination by Tertiary Phosphane Sulfides
Authors: Preisenberger Max , Bauer Andreas , Schmidbaur Hubert 
Published: July 2007

AbstractTreatment of the ditertiary phosphane sulfides (CH2)n[PPh2S]2, 1a–1d, n = 1‐4, with equivalent amounts of (dimethylsulfide)gold(I) chloride (Me2S)AuC1 affords the dinuclear complexes 2a–2d with an AuCl unit attached to each sulfur atom. The chlorides can be converted into the bromides 3a–3c by metathesis using KBr, or by reacting 1d with (tetrahydrothiophene)gold bromide. With [(Ph3P)Au]+ O3SCF3 as the aurating agent for the diphosphane disulfides, the corresponding dicationic products are obtained: {(CH2)n[SPPh2AuPPh3]2}2+ · 2 O3SCF3 (4b‐4d, n = 2‐4). An excess of the reagents does not lead to polygold clustering at the sulfur atoms, and P‐S cleavage occurs instead to give sulfonium salts {S[Au(PPh3)]3}+ X−. The reaction of Ph3PS with equimolar quantities of [ (Ph3P)Au]O3SCF3 leads to the cationic 1:1 complex 5, and with an excess of the agent the P–S bond is ruptured. The structures of compounds 4b and 4d were determined by single‐crystal X‐ray diffraction. The dications have crystallographic centers ot inversion, the coordination at the gold atoms is linear [4b: 179.03(3)° 4d: 175.29(2)°] and the angles at the sulfur atoms are acute [4b: 97.76(4)° 4d: 96.37(3)°], but there are no short Au–Au contacts.
Characteristic Features of Neutral Cyclopropenylium‐Like Compounds: Synthesis, Structure, and Chemical Behavior of a Cyclopropenylioborate Betaine
Authors: Ahlers Wolfgang , Erker Gerhard , Fröhlich Roland , Zippel Frank 
Published: July 2007

AbstractBis(propynyl)zirconocene was treated with B(C6F.5)3 and then with two equivalents of tert‐butyl isocyanide to yield the organometallic three‐membered ring product 8. Subsequent hydrolysis gives the substituted (2‐iminioethylidene)cyclopropeneborate betaine system 9 that exhibits a pronounced cyclopropenylioborate betaine character. This follows from its characteristic structural features (X‐ray crystal‐structure analysis of the isomer cis‐9) and its chemical features. Complex 9 undergoes a very facile cis/trans isomerization by formal rotation around the exocyclic partial CC‐double bond (ΔG+ ≈ 17 kcal mol−1). Compound 9 reacts cleanly in methanol solution with tert‐butyl isocyanide by insertion and ring enlargement to form the four‐membered ring system 12. Compound 12 was also characterized by X‐ray diffraction.
Chiral Metal Carbene Modified [2.2]Metacyclophanes: Synthesis, Structure, and Chiroptic Properties
Authors: Lougen Andrea , Vögtle Fritz , Dötz Karl Heinz , Nieger Martin 
Published: July 2007

AbstractPentacarbonyl(4‐[2.2]metacyclophanyl(methoxy)carbene)‐chromium(0) (6) was prepared according to the Fischer route from 4‐bromo[2.2]metacyclophane. Aminolysis with non‐chiral and chiral amines affords aminocarbene complexes 7‐12. X‐Ray structure analyses for 6 and its aminocarbene analogs 7 and 8 indicate that the incorporation of the chromium‐carbene fragment has no significant influence on the deformation of the [2.2]metacyclophane skeleton.
The Molecular Structures of Tetra(amino)silanes
Authors: Huber Gerald , Schier Annette , Schmidbaur Hubert 
Published: July 2007

AbstractIn a search for crystalline homoleptic tetra(amin)silanes with (mirror)‐symmetrical NR2 substituents, tetrakis( 1‐pyrrolidinyl)silane (1) was prepared by an improved synthetic route, and tetrakis(morpholino)silane (2) was synthesized from SiBr4 and morpholine/Li‐morpholide via the intermediate BrSi[N(CH2CH2)2O]3 (4). With SiCl4 only the monochloro stage, 3, is reached. Tetrakis(4‐methyl‐1‐piperazinyl)silane (5) was prepared similarly, using 4‐methylpiperazine. With (CH2)6NH or (CH2)6NLi and SiBr4 only [(CH2)6N]3SiBr (6) was obtained. The structures of 1, 2 and 5 were determined by single‐crystal X‐ray diffraction. While compound 1 has an irregular molecular geometry following no symmetrical pattern, molecules of 2 and 5 have similar structures with almost superimposable Si(NC2)4 cores of approximate D2d symmetry. The overall molecular symmetry of 2 is reduced only by incongruous folding of the heterocycles, which are all in a chair conformation. The core structures of 2 and 5 are in excellent agreement with the results of density function calculations for Si(NH2)4. Si(NMe2)4 (the crystal structure of which could not be determined) was converted into (Me2N)3SiO‐SO2CF3 (7) by treatment with two equivalents of triflic acid. Reaction of 7 with 1‐naphthylamine/triethylamine affords (Me2N)3SiNHC9H7 (8). With 2,4‐difluoroaniline/NEt3 the analogous derivative (Me2N)3SiNHC6H3F2 (9) is obtained, but with 4‐bromoaniline the product is a silane with the ligands redistributed to give (Me2N2),Si(NHC6H4Br), (10), the structure of which was also determined. It has a non‐standard geometry with very flat nitrogen pyramids at all four substituents.
On the Polymorphism of White Phosphorus
Authors: Simon Arndt , Borrmann Horst , Horakh Jörg 
Published: July 2007

AbstractWhite phosphorus occurs in three modifications. The α form, which exists at roomtemperature, transforms reversibly to the β form at –77°C. The α · β transformation may be strongly delayed. Quenching the α form to –185°C followed by slow warming results in an exothermic reactions with formation of the γ form which transforms into the β form at –120°C in an endothermic reaction. A transition β · γ is not observed. The γ form is characterized by its powder diagram. The structure of the β form is redetermined from a single crystal at –185°C (P., α = 547.88(5), b = 1078.62(11), c = 1096.16(11)pm, α= 94.285(8), β = 99.695(7), γ = 100.680(7)., V = 623.79(10) · 106 pm3, Z = 6 formula units per cell). The P4 molecules exhibit pronounced librational motion in spite of the low temperature of investigation. The arrangement of the centers of the tetrahedra corresponds to the atom positions in the γ‐plutonium structure, which is discussed in relation to the bcc structure.
Phosphane Ligands, 6 The Remarkable Tridentate Coordination of 4,6‐Bis(diphenylphosphanyl)‐dibenzofuran in Ruthenium(II) Complexes
Authors: Vogl Erasmus M. , Bruckmann Joachim , Kessler Magnus , Krüger Carl , Haenel Matthias W. 
Published: July 2007

Abstract4,6‐Bis(diphenylphosphanyl)dibenzofuran (1), despite its large P…P distance of 5.74 Å and its bite angle of ca. 131° was found to be Capable of tridentate coordination to ruthenium (II) chloride. Single crystal X‐ray structure analyses of the new ruthenium (II) complexes 3,4 and 5 revealed that the ligand 1 coordinates to a single ruthenium atom with both phosphorus centers and the dibenzofuran oxygen atom. The remarkable ligand deformation resulting from the coordination is evident from the decrease of the P…P distance by 1 Å to 4.75 Å and the increase of the bite angle (P–Ru–P) by 25° to 155°−157. The unprecedented in‐plane coordination of the dibenzofuran oxygen atom to ruthenium is interesting in view of the hybridisation of the oxygen.