bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lysophosphatidic Acid Modulates the Healing Responses of Human Periodontal Ligament Fibroblasts and Enhances the Actions of Platelet‐Derived Growth Factor
Authors: Cerutis D. Roselyn , Dreyer Andrew C. , Vierra Matthew J. , King Joshua P. , Wagner David J. , Fimple Jacob L. , Cordini Franco , McVaney Timothy P. , Parrish Lawrence C. , Wilwerding Terrence M. , Mattson John S. 
Published: May 2007

Background:Platelet‐derived growth factor (PDGF) has been used to promote healing in many in vitro and in vivo models of periodontal regeneration. PDGF interacts extensively with lysophosphatidic acid (LPA). We recently showed that LPA modulates the responses of human gingival fibroblasts to PDGF. The objectives of this study were as follows: 1) to evaluate the basic interactions of LPA with primary human periodontal ligament fibroblasts (PDLFs) alone and with PDGF‐BB for promoting PDLF growth and migration; 2) to determine the effects in an in vitro oral wound‐healing model; and 3) to identify the LPA receptors (LPARs) expressed by PDLF.Methods:PDLF regenerative responses were measured using 1 and 10 μM LPA in the absence or presence of 1 or 10 ng/ml PDGF. Cell proliferation was determined by 5‐bromo‐2′‐deoxyuridine (BrdU) immunohistochemistry and by cell counting. Migration responses were measured using a microchemotaxis chamber. PDLFs were grown to confluence on glass slides, a 3‐mm‐wide wound was mechanically inflicted, and wound fill on days 4, 6, and 9 was reported. PDLF LPAR expression was determined using Western blotting.Results:PDLFs exhibited proliferative and chemotactic responses to LPA; these responses were enhanced when LPA and PDGF were present together. LPA plus PDGF elicited complete wound fill. PDLFs express the LPARs LPA1, LPA2, and LPA3.Conclusions:To our knowledge, this study provides the first evidence that LPA stimulates human PDLF wound healing responses and interacts positively with PDGF to regulate these actions. These results suggest that LPA and its receptors play important modulatory roles in PDLF regenerative biology.
Clinical Evaluation of the Supraosseous Gingivae Before and After Crown Lengthening
Authors: Perez José R. , Smukler Hyman , Nunn Martha E. 
Published: May 2007

Background: Despite the broad use of crown‐lengthening surgery (CLS), there is no complete agreement as to the desired amount of exposed sound tooth structure needed to accommodate both the restorative needs and the reformation of the supraosseous gingiva (SOG). Classically, it has been proposed that ∼3 mm of SOG, the amount considered by most to be present before surgery, will be reformed after CLS. The purpose of this study was to test the viability of transsulcular probing (TSP) and to determine whether the SOG that forms after CLS is the same as that measured preoperatively.Methods: Nineteen patients underwent CLS with the surgical tooth acting both as the control and the test site. The SOG dimension was measured by TSP before and 6 months after surgery. Stents were used as fixed reference points. Intraclass correlations were calculated to test for the reliability of TSP measurements versus direct‐bone‐level (DBL) measurements. A Wilcoxon signed‐rank test was used to compare the means for the mean buccal, mean lingual, and overall mean SOG dimensions at baseline to corresponding measurements at 6 months.Results: Intraclass correlation coefficients for TSP measures of SOG to DBL measures of SOG ranged from 83.4% agreement to 91.9% agreement, with all correlations being highly significant (P <0.001), indicating a high degree of agreement between TSP and DBL. The differences in SOG dimensions, 6 months after surgery compared to baseline, were as follows: mean buccal, 0.51 mm; mean lingual/palatal, 0.61 mm; overall mean, 0.56 mm. These differences were significant for all three comparisons (P <0.001, P <0.004, and P <0.001, respectively).Conclusions: TSP is an accurate alternative method to DBL in clinically determining SOG dimensions. Six months after CLS, the SOG dimension was reduced by 0.51 to 0.61 mm compared to the presurgical measurement, with these mean differences being statistically significant.
Marijuana Initiation in 2 American Indian Reservation Communities: Comparison With a National Sample
Authors: Whitesell Nancy Rumbaugh , Beals Janette , Mitchell Christina M. , Novins Douglas K. , Spicer Paul , O’Connell Joan , Manson Spero M. 
Published: May 2007

Objectives. We examined disparities in age-related patterns of marijuana initiation in 2 culturally distinct American Indian reservation communities (from the Northern Plains and the Southwest) compared with a national sample. Methods. We used discrete-time survival models to estimate age-related risk for initiation with data from 2 population-based studies: the American Indian Service Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project and the baseline National Comorbidity Survey. Results. Among respondents who were born before 1960, peak risk for marijuana initiation in all samples was at age 18 years, and risk was greatest in the national sample. Among those who were born later than 1960, risk peaked at age 16 years and was highest in the American Indian samples. Males were at increased risk compared with females, especially in the older cohort and the Southwest tribal sample. Conclusions. Findings of disproportionate risk for marijuana initiation among younger members of the tribal samples raise concerns that American Indian reservation youths may be increasingly vulnerable to drug use and its concomitants, which suggests a need for more aggressive prevention efforts in these communities.
A Nationwide Study of Discrimination and Chronic Health Conditions Among Asian Americans
Authors: Gee Gilbert C. , Spencer Michael S. , Chen Juan , Takeuchi David 
Published: May 2007

Objectives. We examined whether self-reported everyday discrimination was associated with chronic health conditions among a nationally representative sample of Asian Americans. Methods. Data were from the Asian American subsample (n = 2095) of the National Latino and Asian American Study conducted in 2002 and 2003. Regression techniques (negative binomial and logistic) were used to examine the association between discrimination and chronic health conditions. Analyses were conducted for the entire sample and 3 Asian subgroups (Chinese, Vietnamese, and Filipino). Results. Reports of everyday discrimination were associated with many chronic conditions, after we controlled for age, gender, region, per capita income, education, employment, and social desirability bias. Discrimination was also associated with indicators of heart disease, pain, and respiratory illnesses. There were some differences by Asian subgroup. Conclusions. Everyday discrimination may contribute to stress experienced by racial/ethnic minorities and could lead to chronic illness.
Hispanic Paradox in Biological Risk Profiles
Authors: Crimmins Eileen M. , Kim Jung Ki , Alley Dawn E. , Karlamangla Arun , Seeman Teresa 
Published: May 2007

Objectives. We examined biological risk profiles by race, ethnicity, and nativity to evaluate evidence for a Hispanic paradox in measured health indicators. Methods. We used data on adults aged 40 years and older (n = 4206) from the National Health and Nutrition Examination Surveys (1999–2002) to compare blood pressure, metabolic, and inflammatory risk profiles for Whites, Blacks, US-born and foreign-born Hispanics, and Hispanics of Mexican origin. We controlled for age, gender, and socioeconomic status. Results. Hispanics have more risk factors above clinical risk levels than do Whites but fewer than Blacks. Differences between Hispanics and Whites disappeared after we controlled for socioeconomic status, but results differed by nativity. After we controlled for socioeconomic status, the differences between foreign-born Hispanics and Whites were eliminated, but US-born Mexican Americans still had higher biological risk scores than did both Whites and foreign-born Mexican Americans. Conclusions. There is no Hispanic paradox in biological risk profiles. However, our finding that foreign-born Hispanics and Whites had similar biological risk profiles, but US-born Mexican Americans had higher risk, was consistent with hypothesized effects of migrant health selectivity (healthy people in-migrating and unhealthy people out-migrating) as well as some differences in health behaviors between US-born and foreign-born Hispanics.
Mortality of Foreign-Born and US-Born Hispanic Adults at Younger Ages: A Reexamination of Recent Patterns
Authors: Eschbach Karl , Stimpson Jim P. , Kuo Yong-Fang , Goodwin James S. 
Published: May 2007

Objectives. We sought to determine whether mortality rates among immigrant and US-born Hispanic young adults were higher or lower compared with non-Hispanic Whites. We also sought to identify which causes of death accounted for the differences in mortality rates between groups. Measures. We used Texas and California vital registration data from 1999 to 2001 linked to 2000 census denominators. We calculated cause-specific, indirectly standardized rates and ratios and determined excess/deficit calculations comparing mortality rates among US- and foreign-born Hispanic men and women with rates among non-Hispanic White men and women. Results. Mortality rates were substantially lower among Hispanic immigrant men (standardized mortality ratio [SMR]=0.79) and women (SMR=0.59) than among non-Hispanic White men and women. Most social and behavioral and chronic disease causes in Texas and California other than homicide were noteworthy contributors to this pattern. Mortality rates among US-born Hispanics were similar to or exceeded those among non-Hispanic Whites (male SMR=1.17, female SMR=0.91). Conclusions. Mortality rates among younger Hispanic immigrants in Texas and California were lower than rates among non-Hispanic Whites. This pattern was not observed among US-born Hispanics, however.
Electromagnetic Interaction of Leptons in the Theory of United Space
Authors: Bich Nguyen Duc , van Phi Duong 
Published: May 2007

AbstractIn this paper we calculate some effective cross‐sections of leptons on the basis of S‐matrix constructed in 8‐dimensional united space [1]. The Lagrangian is chosen, within the framework of the 0 (71) group classification of elementary particles. Electromagnetic interaction does not change the internal structure of the participating particles. The results obtained agree well with experiments.
Eine nichtlineare lorentzinvariante Gravitationstheorie
Authors: Petry W. 
Published: May 2007

AbstractEine nichtlineare Lorentz‐invariante Gravitationstheorie und eine Lorentz‐invariante Hamilton‐Funktion für ein Teilchen mit Spin im Gravitationsfeld werden aufgestellt. Die Bewegungsgleichungen werden studiert. Die Theorie wird auf die drei bekannten Effekte der Allgemeinen Relativitätstheorie angewandt. Für die Rotverschiebung der Spektrallinien und die Lichtablenkung am Sonnenrand erhält man dieselben Resultate wie in der Allgemeinen Relativitätstheorie, während die Theorie für die Perihelbewegung des Merkur 40,3″ ergibt, was in guter Übereinstimmung mit den experimentellen Ergebnissen von DICKE ist.
Bemerkungen zur Teilchenerzeugung im expandierenden Universum
Authors: Kreisel E. 
Published: May 2007

AbstractEs wird gezeigt, daß man spontane Teilchenerzeugung im leeren Minkowski‐Raum beschreiben kann, wenn man Teilchenzahloperator und Hilbertraum in ähnlicher Weise definiert, wie in Arbeiten über Teilchenerzeugung im expandierenden Universum [1–3].Dementsprechend rührt diese spontane Teilchenerzeugung nicht vom Gravitationsfeld her, sondern hängt mit der Nichteindeutigkeit des Teilchenbegriffs und der Auswahl eines zeitabhängigen Teilchenzahloperators zusammen.
On the Gravitational Collapse in Relativistic Theories of Gravitation
Authors: v. Borzeszkowski H.‐H. 
Published: May 2007

AbstractFollowing Einstein, we consider a simple model of a star, namely a spherically symmetric distribution of particles which are all moving along circular orbits around the center of the particle cluster. According to arguments given by Einstein, Laue, Treder and others, the existence of stationary circular motions for all values of r can be considered as a necessary condition for all collapse‐free relativistic (classical) theory o gravitation. The discussion shows that, assuming the validity of the weak principle of equivalence and the principle of causality, one has to consider theories with a g00‐function different from the Einstein‐Schwarzschild one. We discuss some g00 types and show that our point of view leads in the direction of gravitational equations with a cut‐off length.
Die Anwendung relativistisch bewegter Bezugssysteme in der Elektrodynamik
Authors: Guzunajew Z. I. , Kasatschkow W. D. , Terlezkij J. P. 
Published: May 2007

AbstractIn der Arbeit wird eine Methode des Übergangs vom Inertialbezugssystem zu relativistisch bewegten Systemen dargelegt. Die hergeleiteten Transformationsformeln werden zur Lösung einiger Aufgaben der Elektrodynamik benutzt.
Isobaric Analogue State of the 341 KeV Level of Mn56 and Fe56
Authors: El‐Kazzaz S. A. , El‐Nadi L. M. 
Published: May 2007

AbstractWhen Mn55 is bombarded by protons, a proton capture resonance is detected at Ep = (1678 ± 4) KeV. The spectral and angular distribution studies of the (p, γ) and (p, p) reactions at this resonance have established Jπ = 3+, lp, = 1, Γp = (1 = 0.2) KeV and Γ = 17 KeV for the energy level at (11836 ± 4) KeV in the Fe56 nucleus. Comparison of the present results with those obtained by (n, γ) and (d, p) reactions on the Mn55 nucleus suggests that this resonance state is most probably the isobaric analogue of one member of the doublet at 341 KeV in the Mn56 nucleus.
Stoßbestimmte Relaxation des Elektronenensembles im Plasma bei zusätzlicher Aufheizung durch ein elektrisches Feld I. Die charakteristischen Zeiten für den Übergang in stationäre Zustände
Authors: Wilhelm J. , Winkler R. 
Published: May 2007

AbstractAusgehend von der zeitabhängigen Boltzmann‐Gleichung für die Elektronen wird die Zeitentwicklung der Isotropverteilung und der hieraus folgenden makroskopischen Größen, mittlere Energie, Beweglichkeit, Anregungsfrequenz und Energieübertragungsquotienten beim Übergang zwischen zwei stationären Plasmazuständen bestimmt. Dabei beziehen sich die Rechnungen auf ein schwach ionisiertes Neon‐Plasma im Parameterbereich typischer Nieder‐ und Mitteldruckentladungen.Im Resultat dieser Untersuchungen werden Aussagen über die sich um Größenordnungen unterscheidenden charakteristischen Einstellzeiten im Relaxationsprozeß und über ihre Abhängigkeit von den energetischen Ausgleichsprozessen erhalten. Als geeignete Größen zur Charakterisierung der Einstellzeit unter gegebener Parametersituation erweisen sich hierbei die Energieübertragungsquotienten für den Energieverlust über die berücksichtigten Stoßprozesse.
Sea Level Muon Spectrum Derived from Bugaev Model
Authors: Bhattacharyya D. P. 
Published: May 2007

AbstractThe pion and kaon spectra in the atmosphere are derived from primary nucleon spectrum determined by GRIGOROV et al.; they satisfy the relations N(Eπ) dEπ = 0.187 EdEπ and N(Ek) dEk = 0.017 E dEk, respectively. By using the pion‐kaon atmospheric diffusion equation the sea level muon spectrum is calculated and the result compared with the magnetic spectrograph data of ALLKOFER et al. and AYRE et al.
Solitons in Stimulated Raman Scattering
Authors: Steudel H. 
Published: May 2007

AbstractThe semiclassical equations of SRS are derived by the following method: The many‐level molecule is described by the Schrödinger equation and subsequently all amplitudes but those of the essential two levels are eliminated by approximate integration.Especially the case of equal group velocities for pump and Stokes wave is considered. Terms describing a frequency shift due to dynamical Stark effect and a change of refraction index by vibrational excitation can be removed by a suitable transformation.Under various, physically different, assumptions the system of molecular and field equations is reduced to the equations describing a quasimonochromatic pulse propagating in a resonant two‐level system, and in this way we can find a rich manifold of solutions. E.g., the 2π‐pulse of self‐induced transparency can be transferred to SRS. By other assumptions we are led to equations defining the Bäcklund transformation for the sine‐Gordon equation. For this case also soliton type solutions can be constructed.
Renormalized Perturbation Expansion in Kinetic Theory
Authors: Der R. 
Published: May 2007

AbstractLadder summation techniques are applied to the recently developed c‐number diagram expansion for kinetic equations describing the relaxation of quantum fluids. By way of the resummation, the kinetic equations are reformulated in terms of a T‐matrix which describes the scattering of two particles influenced by the remaining particles of the system via the particle statistics (Bose or Fermi). At sufficiently high temperatures (Maxwell‐Boltzmann statistics), the T‐matrix introduced coincides with the usual T‐matrix of conventional two‐body scattering theory in free space. In low‐temperature Fermi systems, the T‐matrix differs from the reaction matrix of the Brueckner‐Goldstone theory because the “healing” property of the two‐body wave function does not obtain.
On the Gravitational Two‐Body Problem in Special Relativity
Authors: Afanasiev G. N. , Asanov R. A. 
Published: May 2007

AbstractThe method of POINCARÉ is applied to the consideration of the gravitational two‐body problem in the framework of Special Relativity. The formulation of the theory contains two arbitrary functions. A specific choice of these functions leads to the correct description of three crucial experiments, supporting General Relativity, and the time delay of radar signals. However, the gyroscope precession is three times less than that of GR (the realization of this experiment is planned this year). The expansion over the inverse powers of the light velocity being performed approximate Lorentz covariant two‐body equations without retardation effects are obtained. These equations are compared with the EIH two‐body equations.
Zum selektiven NMR‐Spinecho‐Verhalten bei Systemen mit I = 1 im Festkörper am Beispiel des Kaliumoxalatmonohydrats
Authors: Behrens H.‐J. , Schnabel B. 
Published: May 2007

AbstractEs wird die Theorie des nichtselektiven Spinechoverhaltens im Festkörper für dipolar gekoppelte Spins I = 1 mit Quadrupolwechselwirkung nach BODEN u. Mitarb. [5] für den Fall der selektiven Einstrahlung auf nur eine Linie des NMR‐Spektrums modifiziert. Die theoretischen Ergebnisse werden mit 1H‐NMR‐Experimenten an den dipolar gekoppelten Protonenpaaren eines (KCOO)2 · H2O‐Einkristalls verglichen. Das ist möglich, weil die Interprotonpaarwechselwirkung in dieser Substanz wesentlich kleiner als die Intraprotonpaarwechselwirkung ist. Es ergibt sich ein Echoverhalten, das gewisse Ähnlichkeiten mit demjenigen heteronuklear gekoppelter Spinsysteme aufweist.
Heteronukleare Spinentkopplung unter dem Einfluß thermischer Bewegungen
Authors: Ernst H. , Fenzke D. , Pfeifer H. 
Published: May 2007

AbstractUnter der Annahme magnetischer Dipol‐IS‐Wechselwirkung wird eine Theorie der heteronuklearen Spinentkopplung für “kurze” Korrelationszeiten entwickelt. Diese enthält als Spezialfälle die kernmagnetischen Relaxationsraten im rotierenden und im festen Koordinatensystem sowie die Kreuzpolarisation zwischen den Spins I und S. In Übereinstimmung mit dieser Theorie tritt für die protonenentkoppelte C‐13 Resonanz von Butanol, das in einem NaY‐Zeolith adsorbiert ist, ein Maximum der Linienbreite als Funktion der Temperatur zwischen − 150°C und + 90°C auf.
Moleküldynamische Berechnungen an einem zweidimensionalen Ensemble von Doppelzylindern ‐ ein Modell für die lamellare Phase von Phospholipiden
Authors: Frischleder H. , Werge C. 
Published: May 2007

AbstractMit der Methode der Moleküldynamik wurden die strukturellen und dynamischen Eigenschaften eines 2‐dimensionalen Systems von Doppelzylindern/Hanteln untersucht. Dieses System ist ein Modell für die lamellare Phase von Phospholipid/Wasser‐Systemen sowie der Biomembran‐Lipidkomponente. Die „herring‐bone”︁‐Struktur wurde als energetisch stabilste Anordnung der Hanteln in der Ebene gefunden, wobei sowohl die Molekülschwerpunkte als auch die Zylinderachsen pseudohexagonale Gitter bilden. Bei einer Teilchenzahldichte von 0,452 nm−2 und einer Temperatur von 310 K wurde ein lateraler Druck von (40‐60) dyn · cm−1 ermittelt, der mit experimentellen Werten von (30‐45) dyn · cm−1 sehr gut übereinstimmt. Die laterale Selbstdiffusionskonstante der Modellmoleküle ist im Vergleich zu experimentellen Werten um eine Größenordnung zu groß, die berechnete Rotationskorrelationszeit dagegen stimmt mit experimentellen Werten gut überein.
Darstellung temperaturabhängiger spektraler Eigenschaften des adsorptionsbedingten Emissionsrauschens durch Lorentzfunktionen
Authors: Kleint Ch. 
Published: May 2007

AbstractFür eine erste Deutung der komplizierten Temperaturabhängigkeit der Spektraldichtefunktionen des Rauschens verschiedener Adsorptionssysteme wird eine Methode vorgeschlagen, die durch eine Darstellung der beobachteten Abhängigkeiten vermittels Lorentzfunktionen eine Zurückführung auf die hauptsächlich wirksamen Aktivierungsenergien (und Entropien) ermöglicht. Verschiedene Varianten werden begründet und einige Beispiele für die Anpassung an experimentelle Spektren gebracht.
Die Charakterisierung der Lösungen von Mastergleichungen, ein „inverses”︁ Problem
Authors: Alberti Peter M. , Uhlmann Armin 
Published: May 2007

AbstractIn einem endlich‐dimensionalen Parameterraum sei eine Kurve gegeben. Wir beantworten die Frage, wie diese Kurve beschaffen sein muß, um Lösung einer Mastergleichung zu sein.
Simultaneous Diffraction of Two Waves at a Transmission Volume Hologram
Authors: Kowarschik R. 
Published: May 2007

AbstractOn the basis of the theory of coupled waves the simultaneous diffraction of two waves at a plane dielelectric transmission volume hologram is described. The intensities of the output beams strongly depend on the phase shift between the incident waves and the phase shift of the holographic grating with respect to the interference pattern of the read‐out waves. This gives the possibility to transfer the energy from one beam into the other and can be used for the modulation and deflection of the reconstructed beams. The possibility of a separate determination of the different phase shifts by intensity or phase measurements is discussed.
On the Metric and Non‐metric Spaces for the Mechanics of Generalized Continua
Authors: Günther Helmut , Minagawa Sitiro 
Published: May 2007

AbstractThe paper is concerned with the description of structural defects of a mechanicof continuum in terms of geometry. It depends on the spacing of defects relatively to the spacing m the underlying discrete physical structure, if defects may be described separately by the continuup. picture; otherwise a microdistribution of defects is arising. It is shown, how the microrotations resni microdeformations of a micropolar resp. multipolar continuum give a phenomenological description for a remaining microdistribution of defects. Geometrically this is described by the Lemma of Riccl resp. the violation of this lemma.
On the Validity of Several Methods of Calculation of Vibronic Energy Relaxation Rates
Authors: Madzgalla I. , Paerschke H. , Süsse K.‐E. , Welsch D.‐G. 
Published: May 2007

AbstractDifferent approximation methods of calculation of the rates of vibronic energy relaxation are studied and compared with an exact one. The molecular vibrations are described by harmonic oscillators, the positions of equilibrium of which are assumed to be different in different electronic states. The finite line widths of the vibronic states are taken into account. It is found that the approximation methods provide too small values of the relaxation rates, particularly as the coupling strength becomes weak.