bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase diagrams beyond the critical point
Authors: Hoffmann H.‐J. 
Published: July 2008

AbstractFollowing a path in the usual p‐T‐diagrams of one‐component systems via the supercritical region it seems that one can make a transition from the liquid to the gas phase (and in reverse) without traversing a phase boundary curve, whereas in the sub‐critical region one clearly has to pass a phase boundary curve. To solve this paradox situation, the phase diagrams of one‐component systems are analyzed with respect to the phase transition from the liquid to the gas state in the sub‐ and supercritical range. It is shown that the critical point is not an isolated point or an end point on the phase boundary curve between the gaseous and the liquid phase in a p‐T‐diagram. Instead, it marks on the boundary curve just the transition between the section of a first order phase transition in the sub‐critical range and the section of a second or higher order phase transition in the supercritical range. Thus, the present phase diagrams of one‐component systems are incomplete with respect to the phase boundary curve between liquid and gas in the supercritical region. The result is illustrated using the model of a van der Waals gas.
Cost‐efficient conversion coatings for corrosion protection prepared by the sol‐gel process
Authors: Lampke Th. , Darwich S. , Wielage B. , Steinhäuser S. 
Published: July 2008

AbstractFor several years, chromate compounds were used as effective and inexpensive corrosion inhibitors. Studies showed that these materials were toxic and carcinogenic. A subsequent ban on these materials has led to extensive research to develop effective alternative inhibitors. The sol‐gel method appeared as an effective technique forming protective silane layers from hydrolyzed tetraethylorthosilicate (TEOS) and glycidoxypropyltrimethoxy silane (GPTMS) in an aqueous sol–gel process. The final cross‐linking of the layer is realized by heat treatment to form thin, fully dense, protective films of silane on diverse metal surfaces.Most sol‐gel layers use a considerable amount of solvent VOC (volatile organic compound) in order to achieve a dispersion of silane with water. However, in a wide range of industries, the high amount of VOC is the major hindrance for the application of silane layers. This article shows a coating concept without VOC, which is cost‐efficient, effective for corrosion protection and applicable for metal surfaces. The corrosion protection effect is given by means of comprehensive impedance spectroscopy measurements.
Einsatz von Hartstoffbeschichtungen bei Spindellagern
Authors: Brecher C. , Spachtholz G. , Gerlach G. 
Published: July 2008

AbstractDie Ansprüche an moderne Werkzeugmaschinen (WZM) steigen kontinuierlich mit den Forderungen der Produktion nach qualitativ hochwertigen und immer kürzeren Bearbeitungsprozessen. Insbesondere die Zunahme der Bearbeitungs‐ und Schnittgeschwindigkeiten der letzten Jahre führt zu einer höheren Belastung der Lagerung der Hauptspindel. Diese kennzeichnet als zentrale Komponente das Leistungsvermögen einer Werkzeugmaschine für die spanende Bearbeitung und ist maßgebend für die Zuverlässigkeit der Hauptspindel.Die überwiegend eingesetzten Spindellagerungen sind wälzgelagert ausgeführt. Ein großer Anteil der in der Praxis auftretenden Spindelausfälle resultiert aus mangelnder bzw. unzureichender Schmierung der Lagerungen und somit aus den tribologischen Eigenschaften der Wälzpartner. Zur Reduzierung von Reibung und Verschleiß werden heutzutage sowohl unterschiedliche Werkstoffe und Beschichtungen für die Lagerkomponenten eingesetzt als auch verschiedene Additive den Schmierstoffen zugefügt.Aktuelle Forschungen zielen darauf ab, Hartstoffschichten (a‐C:H:W) mit einer Metall‐Nanodotierung für den Wälzkontakt zu entwickeln, welche die Zuverlässigkeit der Lager erhöhen sollen.In diesem Artikel wird daher die Erprobung von Lagern mit nanostrukturierten Schichtsystemen zur Reduktion der Reibung und somit der Wärmeeinbringung sowie des Verschleißes vorgestellt. Dazu werden die Schichtsysteme durch Voruntersuchungen für den Einsatz in Spindellagern geprüft. Basierend auf diesen Ergebnissen werden die Lagerringe von Standard‐Hybrid‐Spindellagern beschichtet und die Schichthaftung hinsichtlich Drehzahleignung, Dauerfestigkeit sowie Verschleißverhalten bei hoher Beschleunigung analysiert. Abschließend werden die Notlaufeigenschaften der Lagerkomponenten bei Mangelschmierung evaluiert, um das Einsatzfeld der Beschichtungen ermitteln zu können.
Mikrostrukturelle und mechanische Eigenschaften von laserstrahlgeschweißtem Magnesiumfeinblech AZ31‐HP mit und ohne Zusatzwerkstoffe
Authors: Ventzke V. , Riekehr S. , Koçak M. 
Published: July 2008

AbstractGegenstand dieses Manuskripts sind Untersuchungen an einem gewalzten Mg‐Magnesiumfeinblech der Dicke 2,5 mm aus AZ31‐HP, welches in Stumpfstoßausführung mit und ohne Zusatzwerkstoffe laserstrahlgeschweißt wurde. Als Zusatzwerkstoffe wurden AZ31X und AZ61A‐F in Spulendrahtform mit einem Durchmesser von 1,2 mm verwendet. Die mikrostrukturellen und mechanischen Eigenschaften der unterschiedlich laserstrahlgeschweißten Magnesiumlegierung AZ31‐HP wurden untersucht und miteinander verglichen. Die Ergebnisse zeigen, dass das Feinblech AZ31‐HP mit oder auch ohne Zusatzwerkstoffe ohne Heißrissbildung laserstrahlschweißbar ist. Die an der ohne Zusatzdraht geschweißten Verbindung ermittelten Eigenschaften wie Festigkeit, Duktilität, Mikrohärte und Bruchzähigkeit wurden weder durch AZ31X noch durch AZ61A‐F beeinflusst, lediglich geringe Zn‐Verluste werden mit den Zusatzdrähten ausgeglichen sowie die Nahtform verbessert. Die Werte für Zugfestigkeit, Dehngrenze und Mikrohärte sind für die Laserstrahlschweißverbindungen und des Grundwerkstoffs nahezu gleich. Bedingt durch die Gefügeheterogenität in den Fügezonen und durch die nahtgeometrischen Kerben sind die Schweißverbindungen im Vergleich zum Grundwerkstoff durch eine deutlich niedrigere Duktilität gekennzeichnet. Sowohl der Grundwerkstoff als auch die Laserstrahlschweißnähte zeigten stabile Rissausbreitung, wobei die Bruchzähigkeit des Grundwerkstoffs etwas niedriger war als die der Schweißnähte.
Cytochrome P450 1B1 expression in rat esophageal tumorigenesis promoted by gastric and duodenal reflux
Authors: Devlin Andrea H. , McIlroy Marie , McKeen Hayley D. , Bonde Pramode , Menezes A.A. Carlos , Swarbrick Christine J. , Robson Tracy , Hirst David G. , Campbell F. Charles , McGuigan James A. , McKeown Stephanie R. 
Published: July 2008

AbstractCytochrome P450 1B1 (CYP1B1) mRNA is constitutively expressed in most normal extra‐hepatic tissues; however the protein is not detectable in these tissues but is expressed in a wide variety of tumors. CYP1B1 is responsible for the activation of a number of carcinogens present in tobacco smoke and food. A surgical model of rat esophageal tumorigenesis, promoted by gastric or duodenal reflux was used to determine CYP1B1 expression in premalignant esophageal tissue. Immunohistochemistry was performed using a modified amplified fluorescein tyramide protocol. CYP1B1 was not observed in normal esophageal mucosa, submucosa, or muscularis mucosa. Animals exposed to gastric reflux developed mild hyperplasia. Varying degrees of hyperplasia were observed in the duodenal reflux group. All regions of hyperplasia showed moderate or strong CYP1B1 immunoreactivity. Duodenal reflux induced a small number of premalignant changes: immunoreactivity was absent from the epithelium of squamous dysplasia (0/10), Barrett's esophagus (0/7), and majority of dysplastic Barrett's esophagus (1/4). Moderate or strong immunoreactivity was observed in the majority (7/8) of squamous cell carcinomas (SCCs) in situ. Immunoreactivity was also observed in the lamina propria and submucosa in association with inflammation, regardless of the severity of inflammation. The expression of CYP1B1 in hyperplasia, SCCs in situ, or in association with inflammation may increase the production of carcinogenic metabolites, which may promote esophageal tumorigenesis. © 2008 Wiley‐Liss, Inc.
Calcium and calcium sensing receptor modulates the expression of thymidylate synthase, NAD(P)H:quinone oxidoreductase 1 and survivin in human colon carcinoma cells: Promotion of cytotoxic response to mitomycin C and fluorouracil
Authors: Liu Guangming , Hu Xin , Varani James , Chakrabarty Subhas 
Published: July 2008

AbstractCa2+ and the cell‐surface calcium sensing receptor (CaSR) constitute a novel and robust ligand/receptor system in regulating the proliferation and differentiation of colonic epithelial cells. Here we show that activation of CaSR by extracellular Ca2+ (or CaSR agonists) enhanced the sensitivity of human colon carcinoma cells to mitomycin C (MMC) and fluorouracil (5‐FU). Activation of CaSR up‐regulated the expression of MMC activating enzyme, NAD(P)H:quinone oxidoreductase 1 (NQO‐1) and down‐regulated the expression of 5‐FU target, thymidylate synthase (TS) and the anti‐apoptotic protein survivin. Cells that were resistant to drugs expressed little or no CaSR but abundant amount of survivin. Disruption of CaSR expression by shRNA targeting the CaSR abrogated these modulating effects of CaSR activation on the expression of NQO1, TS, survivin and cytotoxic response to drugs. It is concluded that activation of CaSR can enhance colon cancer cell sensitivity to MMC and 5‐FU and can modulate the expression of molecules involved in the cellular responses to these cytotoxic drugs. © 2008 Wiley‐Liss, Inc.
Suicidal and death ideation in Parkinson's disease
Authors: Nazem Sarra , Siderowf Andrew D. , Duda John E. , Brown Gregory K. , Ten Have Tom , Stern Matthew B. , Weintraub Daniel 
Published: July 2008

AbstractParkinson's disease (PD) is a chronic, disabling illness affecting primarily the elderly and is associated with a high prevalence of depression. Although these are known risk factors for suicidal and death ideation, little is known about the prevalence and correlates of such ideation in PD. A convenience sample of 116 outpatients with idiopathic PD at two movement disorders centers were administered a modified Paykel Scale for suicidal and death ideation, as well as an extensive psychiatric, neuropsychological, and neurological battery. Univariate and multivariate logistic regression models were used to determine the correlates of suicidal or death ideation. Current death ideation (28%) or suicide ideation (11%) were present in 30% of the sample, and 4% had a lifetime suicide attempt. On univariate logistic regression analysis, increasing severity of depression (odds ratio = 2.92, 95% CI 2.01–4.24, P < 0.001), impulse control disorder (ICD) behaviors sometime during PD (odds ratio = 6.08, 95% CI 1.90–19.49, P = 0.002), and psychosis (odds ratio = 2.45, 95% CI 1.05–5.69, P = 0.04) were associated with either ideation. On multivariate logistic regression analysis, only increasing severity of depressive symptoms (odds ratio = 2.76, 95% CI 1.88–4.07, P < 0.001) predicted suicidal or death ideation. In conclusion, active suicidal or death ideation occurs in up to one‐third of PD patients. Comorbid psychiatric disorders, more than PD‐related disease variables, are associated with this ideation, highlighting the need for a comprehensive approach to the clinical care of PD patients. © 2008 Movement Disorder Society
Striatal dopamine transporter imaging correlates with depressive symptoms and tower of London task performance in Parkinson's disease
Authors: Rektorova Irena , Srovnalova Hana , Kubikova Radka , Prasek Jiri 
Published: July 2008

AbstractWe studied whether the 123I‐FP‐CIT uptake in the striatum correlates with depressive symptoms and cognitive performance in patients with Parkinson's disease (PD). Twenty patients with PD without major depression and/or dementia (mean age 61.7 ± 12.7 years) underwent the 123I‐FP‐CIT SPECT. Depressive symptoms and cognitive performance were assessed in the ON state. The ratios of striatal to occipital binding for the entire striatum, putamina, and putamen to the caudate (put/caud) index were calculated in the basal ganglia. The association between neuropsychiatric measures and dopamine transporter (DAT) availability was calculated; multiple regression analysis was used to assess association with age and disease duration. We found significant correlations between Montgomery and Asberg Depression Rating Scale (MARDS) and Tower of London (TOL) task scores and 123I‐FP‐CIT uptake in various striatal ROIs. Multiple regression analysis confirmed the significant relationship between TOL performance and put/caud ratio (P = 0.001) and to age (P = 0.001), and between MADRS and left striatal (P = 0.005) and putaminal DAT availability (P = 0.003). Our pilot study results demonstrate that imaging with 123I‐FP‐CIT SPECT appears to be sensitive for detecting dopaminergic deficit associated with mild depressive symptoms and specific cognitive dysfunction in patients with PD, yet without a current depressive episode and/or dementia. © 2008 Movement Disorder Society
Hand reconstruction with lobulated combined flaps based on the circumflex scapular pedicle
Authors: Gao Weiyang , Hong Jianjun , Li Zhijie , Chen Xinglong 
Published: July 2008

AbstractRepair of multiple soft tissue defects on hand often pose a difficult problem to the reconstructive surgeons with employing a limited number of reliable flaps and recipient vessels. This report is to explore the feasibility and advantage of the treatment of multiple soft tissue defects on hand with combined island flaps based on branches of the circumflex scapular system. From 2002 to 2006, nine patients had transfer of the scapular lobulated combined flaps based on the transverse branch, ascending branch, and descending branch of the circumflex scapular vascular pedicle for coverage of soft‐tissue defects over injured hands. Follow‐up ranged from 6 months to 24 months with average 12.1 months' all of nine flaps completely survived without complications. Arterial insufficiency was found in one flap because of the pedicle compression in the subcutaneous tunnel. The blood supply to flap was restored after the compression was released. All transferred flaps showed good appearance without significantly swelling and congestion. Two flaps underwent secondary debulking surgery. At 6 months postoperatively, partial protective sensation (S1) was restored in the flaps. The donor sites were directly closed in six cases. Skin grafts were used to cover the donor sites in other three cases. All of donor sites healed without complications. Our report shows that the management of multiple soft tissue defects on hand in complex hand injuries with lobulated flaps of circumflex scapular system can obtain good results for its good appearance and low donor site complications. It is probably the optimal surgical intervention for these injuries. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Polynomial and analytic stabilization of a wave equation coupled with an Euler–Bernoulli beam
Authors: Ammari Kaïs , Nicaise Serge 
Published: July 2008

AbstractWe consider a stabilization problem for a model arising in the control of noise. We prove that in the case where the control zone does not satisfy the geometric control condition, B.L.R. (see Bardos et al. SIAM J. Control Optim. 1992; 30:1024–1065), we have a polynomial stability result for all regular initial data. Moreover, we give a precise estimate on the analyticity of reachable functions where we have an exponential stability. Copyright © 2008 John Wiley & Sons, Ltd.
Scattering of an incident acoustic wave by an infinite elastic cylinder in a shallow sea
Authors: Lee Doo‐Sung 
Published: July 2008

AbstractThe scattering of sound waves by an isotropic elastic circular cylinder of infinite extent in a water of finite depth is investigated taking into account the shear waves that can exist in addition to compressional waves in scatterers of solid material. The axis of the cylinder is parallel to the water level.The reflected and transmitted energies are plotted for the various values of the radius of the cylinder, and the farfield scattered pressure is obtained for various depth and presented in a graphical form. Copyright © 2008 John Wiley & Sons, Ltd.
Notes on ferromagnetic p‐spin and REM
Authors: Barra Adriano 
Published: July 2008

AbstractIn this paper we apply some of the recent mathematical techniques (mainly based on interpolation) developed in the spin glass theory to the ferromagnetic p‐spin model. We introduce two Hamiltonians and derive their thermodynamics. This is a second step toward an alternative and rigorous formulation of the statistical mechanics of simple systems on lattice. A first step has been performed in J. Stat. Phys. (2007; arXiv:0712.1344) where the techniques have been tested on the two‐body Ising model. For completeness the adaptation of the well‐known random energy model to the context of the ferromagnetism is presented. At the end a discussion on the extension of these techniques to Gaussian‐disordered p‐spin models is also briefly outlined. Copyright © 2008 John Wiley & Sons, Ltd.
A boundary obstacle problem for the Mindlin–Timoshenko system
Authors: Araruna F. D. , Feitosa A. J. R. , Oliveira M. L. 
Published: July 2008

AbstractWe consider the dynamical one‐dimensional Mindlin–Timoshenko model for beams. We study the existence of solutions for a contact problem associated with the Mindlin–Timoshenko system. We also analyze how its energy decays exponentially to zero as time goes to infinity. Copyright © 2008 John Wiley & Sons, Ltd.
Multi‐dimensional inhomogeneity indicators and the force on uncharged spheres in electric fields
Authors: Langemann Dirk 
Published: July 2008

AbstractUncharged droplets on outdoor high‐voltage equipment suffer a non‐vanishing total force in non‐homogeneous electric fields. Here, the model problem of a spherical test body is considered in arbitrary dimensions. A series expansion of inhomogeneity indicators is proven, which approximates the total force in local terms of the undisturbed electric field. The proof uses the ideas of generalized spherical harmonics without referring to the particular choice of the orthonormal system. The fast converging series expansion establishes a relationship between the solutions of two partial differential equations on different domains. Copyright © 2008 John Wiley & Sons, Ltd.
In vivoassessment of herb–drug interactions: Possible utility of a pharmacogenetic approach?
Authors: Tomlinson Brian , Hu Miao , Lee Vivian W. Y. 
Published: July 2008

AbstractHerbal medicines are frequently used in combination with conventional drugs and interactions are likely to be more common than those which manifest clinically. Pharmacokinetic interactions mediated by drug‐metabolizing enzymes or transporters are involved in many herb–drug interactions. Polymorphisms in the genes for these enzymes and transporters may influence the interactions mediated through these pathways. Herb–drug interactions can be identifiedin vivousing the herbs with individual probe drugs or drugs with a narrow therapeutic index. A probe drug cocktail approach offers a more efficient screening procedure. If potential interactions are studied in subject groups with different genotypes, more definitive information can be obtained. The selection of genotype groups to study should depend not only on the major enzymes or transporters involved in the disposition of a drug, but also on alternate pathways which may become more important in subjects with reduced activity in the primary pathway, and the pathways for pharmacodynamic effects should also be considered for some drugs. Some genotypes may only be found in certain ethnic groups. Currently, the pharmacogenetic approach has been used mainly to study drug–drug interactions so there is considerable potential to extend this to the study of herb–drug interactionsin vivo.
Comparison of delphinidin, quercetin and (–)‐epigallocatechin‐3‐gallate as inhibitors of the EGFR and the ErbB2 receptor phosphorylation
Authors: Fridrich Diana , Teller Nicole , Esselen Melanie , Pahlke Gudrun , Marko Doris 
Published: July 2008

AbstractIn the present study, delphinidin was found to suppress the phosphorylation of the epidermal growth factor receptor (EGFR) within human tumour cells (human colon carcinoma cell line (HT29), human vulva carcinoma cell line (A431)), albeit less effective than the flavonol quercetin. The higher potency of quercetin was also observed downstream on the level of the mitogen‐activated protein kinase (MAPK) cascade. In addition, delphinidin, quercetin and (–)‐epigallocatechin‐3‐gallate (EGCG) were found to suppress the phosphorylation of the ErbB2 receptor, with delphinidin exhibiting the strongest inhibitory properties. Their potency to suppress the ErbB2 receptor phosphorylation can be summarised as delphinidin > EGCG > quercetin. The effectiveness of delphinidin against the EGFR and the ErbB2 receptor was comparable, indicating a broader spectrum of activity against receptor tyrosine kinases. At low micromolar concentrations delphinidin showed some preference towards the ErbB2 receptor. In summary, quercetin and delphinidin appear to differ in their activity profile towards the ErbB receptor family members. Whereas quercetin was most effective against the EGFR, delphinidin exhibited some preference towards the ErbB2 receptor.
Saturation transfer double‐difference NMR spectroscopy using a dual solenoid microcoil difference probe
Authors: Bergeron Scott J. , Henry Ian D. , Santini Robert E. , Aghdasi Abdollah , Raftery Daniel 
Published: July 2008

AbstractAn experiment designed to collect a saturation transfer double difference (STDD) NMR spectrum using a solenoid microcoil NMR difference probe is reported. STDD‐NMR allows the investigation of ligand‐biomolecule binding, with moderate concentration requirements for unlabeled molecular targets and the ability to discern binding events in the presence of non‐binding ligands. The NMR difference probe acquires the signals from two different samples at once, and cancels common signals automatically through a mechanism of switching between parallel excitation and serial acquisition of the sample signals. STDD spectra were acquired on a system consisting of human serum albumin and two ligands, octanoic acid and glucose. The non‐binding ligand, glucose, was cancelled internally through phase cycling, while the protein signal was subtracted automatically by the difference probe. The proton NMR resonance signal from octanoic acid remained in the double difference spectrum. This work demonstrates that the double difference can be performed both internally and automatically through the utilization of the solenoid microcoil NMR difference probe and STDD‐NMR pulse sequence, resulting in a clean signal from the binding ligand with good protein background subtraction and an overall favorable result when compared to the conventional approach. Copyright © 2008 John Wiley & Sons, Ltd.
Structural determination of flavonoids from Sorphora flavescens
Authors: Ma Xiao‐Chi , Xin Xiu‐Lan , Zhang Bao‐Jing , Li Feng‐Yun , Liu Ke‐Xin , Guo De‐An 
Published: July 2008

AbstractEight flavonoids were isolated from Sophora flavescens. Among them, three prenylflavanones: (2S)‐6[2(3‐hydroxyisopropyl)‐5‐methyl‐4‐hexenyl]‐5‐methoxy‐7,2′, 4′‐trihydroxyflavanone (1), (2S)‐5, 4′‐dimethoxy‐8‐lavandulyl‐7, 2′‐dihydroxy flavanone (2) and (2S)‐8‐(5‐hydroxy‐2‐isopropenyl‐5‐methylhexyl)‐7‐methoxy‐5,2′, 4′‐trihydroxyflavanone (3) are new compounds. Their chemical structures were determined by spectral methods including 2D NMR. Copyright © 2008 John Wiley & Sons, Ltd.