bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erythromelalgia: A hereditary pain syndrome enters the molecular era
Authors: Waxman Stephen G. , Dib‐Hajj Sulayman D. 
Published: May 2005

AbstractIn contrast with acquired pain syndromes, molecular substrates for hereditary pain disorders have been poorly understood. Familial erythromelalgia (Weir Mitchell's disease), also known as primary erythermalgia, is an autosomal dominant disorder characterized by burning pain in the extremities in response to warm stimuli or moderate exercise. The cause of this disorder has been enigmatic, and treatment has been empirical and not very effective. Recent studies, however, have shown that familial erythromelalgia is a channelopathy caused by mutations in the gene encoding the Nav1.7 sodium channel which lead to altered channel function. Selective expression of Nav1.7 within dorsal root ganglion neurons including nociceptors (in which this channel is targeted to sensory terminals, close to impulse trigger zones) and within sympathetic ganglion neurons explains why patients experience pain but do not suffer from seizures or other manifestations of altered excitability within central nervous system neurons. Erythromelalgia is the first human disorder in which it has been possible to associate an ion channel mutation with chronic neuropathic pain. Identification of mutations within a peripheral neuron‐specific sodium channel suggests the possibility of rational therapies that target the affected channel. Moreover, because some other pain syndromes, including acquired disorders, involve altered sodium channel function, erythromelalgia may emerge as a model disease that holds more general lessons about the molecular neurobiology of chronic pain. Ann Neurol 2005;57:785–788
Different Environments for a Realistic Simulation of GPCRs‐Application to the M2 Muscarinic Receptor
Authors: Jöhren Kirstin , Höltje Hans‐Dieter 
Published: May 2005

AbstractA model of the human M2 muscarinic receptor was taken as an example for a class A G‐protein coupled receptor to explore the influence of different environments in a molecular dynamics simulation (MDS) on the protein structure. The most commonly used environment is the vacuum, although it is very unnatural for a transmembrane protein. As an alternative a membrane‐like system, consisting of a lipophilic central layer and two aqueous flanking layers, was tested. The most realistic system that can be applied is a phospholipid bilayer with a surrounding physiological sodium chloride solution. From all systems good protein structures were received, nevertheless clear differences between the systems were detected in the structural comparison of the models. Subsequently it was analyzed whether the observed structural differences influence ligand binding. For this purpose the antagonist (S)‐scopolamine was docked into the binding cavity, which is well known by many reported single and multiple point mutations. As expected from the observed structural variations triggered by the type of environment employed in MDS, also differences in the binding mode of (S)‐scopolamine were detected, all contacts, however, which are known to be important were found.
Pharmacokinetics of the diastereomers of arteether, a potent antimalarial drug, in rats
Authors: Sabarinath S. , Madhusudanan K. P. , Gupta R. C. 
Published: May 2005

AbstractThe pharmacokinetics of α‐ and β‐ diastereomers of arteether, a potent erythrocytic schizontocidal agent, and their active metabolite dihydroartemisinin were studied in male Sprague‐Dawley rats after oral, intramuscular and intravenous administrations. Oral and intramuscular studies were carried out at three dose levels at 9, 17.5 and 30 mg kg−1. The ratio of α‐ and β‐isomers was maintained at 30:70% w/w in the formulations used for the study. The average oral bioavailabilities of α‐and β‐isomers, relative to intramuscular administration, were 9.6% and 3.8%, respectively, and the average in vivo α‐ to β‐ ratio was 2.5. Following intravenous and intramuscular administrations the in vivo α‐ to β‐ ratios were 0.7 and 0.9, respectively. The β‐isomer of arteether was characterized by a longer elimination half‐life and a relatively larger volume of distribution than the α‐isomer, suggesting that β‐arteether may be responsible for the prolonged in vivo schizontocidal activity. The α‐isomer was absorbed rapidly after oral and intramuscular administrations and showed higher peak plasma concentrations but possessed a relatively shorter half‐life. There was an apparent lack of linearity observed in terms of dose and AUCs for both α‐ and β‐arteether after oral and intramuscular administrations, suggesting nonlinear dose dependent pharmacokinetics at the dose levels studied. The rate and extent of conversion of arteether isomers to dihydroartemisinin was highest with oral and intravenous administration and least with intramuscular indicating that the intramuscular route of administration of the isomeric mixture may be more beneficial for malarial chemotherapy. Copyright © 2005 John Wiley & Sons, Ltd.
Effects of enzyme inducers and inhibitors on the pharmacokinetics of intravenous DA‐8159, a new erectogenic, in rats
Authors: Kim Yu C. , Shim Hyun J. , Lee Joo H. , Kim Soon H. , Kwon Jong W. , Kim Won B. , Lee Myung G. 
Published: May 2005

AbstractIn order to find what types of hepatic microsomal cytochrome P450 (CYP) isozymes are involved in the metabolism of DA‐8159 and in the formation of DA‐8164 in rats, enzyme inducers, such as dexamethasone, phenobarbital, 3‐methylcholanthrene and isoniazid, and enzyme inhibitors, such as troleandomycin and quinine, were pretreated in rats. After a 1 min intravenous administration of DA‐8159 at a dose of 30 mg/kg to rats pretreated with dexamethasone (a main inducer of CYP3A1/2 in rats), the total areas under the plasma concentration‐time curve from time zero to time infinity (AUC) values of DA‐8159 (283 versus 349 µg min/ml) and DA‐8164 (98.0 versus 79.8 µg min/ml) were significantly smaller and greater, respectively, than those in control rats. However, the AUC values of DA‐8159 were not significantly different after pretreatment with phenobarbital, isoniazid and 3‐methylcholanthrene (main inducers of CYP2B1/2, 2E1 and 1A1/2, respectively, in rats). In rats pretreated with troleandomycin (a main inhibitor of CYP3A1/2 in rats), the AUC values of DA‐8159 (435 versus 370 µg min/ml) and DA‐8164 (34.8 versus 76.5 µg min/ml) were significantly greater and smaller, respectively. However, in rats pretreated with quinine (a main inhibitor of CYP2D1 in rats), the AUC of DA‐8159 was comparable to that in control rats. The above data indicate that DA‐8159 was metabolized and DA‐8164 was formed mainly via CYP3A1/2 in rats. Copyright © 2005 John Wiley & Sons, Ltd.
Die Ermüdungstragfähigkeit von Dübeln unter Querlast
Authors: Block Klaus , Dreier Friedrich , Bigalke Detlef 
Published: May 2005

AbstractZur Bestimmung des Einflusses der Betoneigenschaften auf die Ermüdungstragfähigkeit von Dübeln unter Querlast wurden Versuche an Verbundankern in der Größe M12 durchgeführt. Zu den untersuchten Betoneigenschaften gehören die Druckfestigkeit des Betons und ein Riß von 0, 3 mm Breite im Vergleich zum ungerissenen Beton. Die gewonnenen Ergebnisse ergaben für alle vier Versuchsreihen jeweils eine Wöhlerlinie. Darüber hinaus wurde sowohl für den gerissenen als auch für den ungerissenen Beton eine Funktion aufgestellt, mit der sich die Dauerermüdungstragfähigkeit der Verbundanker in einer beliebigen Betonfestigkeit abschätzen läßt. In bisherigen Zulassungen sind nur die ungünstigsten Werte der Ermüdungstragfähigkeit angegeben. Weiterhin konnten an den Bruchstellen und den aufgezeichneten Kenngrößen mehrere Merkmale erkannt werden, die auf die Versagensart schließen lassen. Eine bessere Planung der folgenden Versuche wird so erleichtert.
Tragverhalten einbetonierter Scherbolzen
Authors: Randl Norbert 
Published: May 2005

AbstractZur Übertragung der Querkräfte bei Bewegungsfugen wie auch zur Herstellung querkraftschlüssiger Verbindungen etwa im Betonfertigteilbau werden häufig stabförmige Stahldorne eingesetzt, die beidseitig in die anschließenden Stahlbetonbauteile eingespannt sind. Im vorliegenden Beitrag wird ein Überblick über den aktuellen Stand der Technik gegeben. Versuche aus jüngerer Zeit an beidseitig einbetonierten, randfernen Schubdornen aus Bewehrungsstahl werden vorgestellt und analysiert. Auf Basis eines modifizierten Bettungsziffernverfahrens wird unter Berücksichtigung der Plastizierung des Betons eine Bemessungsformel zur Ermittlung der Quertragfähigkeit einbetonierter Scherbolzen abgeleitet und mit bestehenden theoretischen Ansätzen und experimentellen Ergebnissen verglichen.
Betonverbinder für eine Hochgeschwindigkeits‐Bahnstrecke
Authors: Kunz Jakob 
Published: May 2005

AbstractBei einem der derzeit größten europäischen Bahninfrastrukturprojekte, der Hochgeschwindigkeitsstrecke zwischen Amsterdam und Brüssel, wird auf einer Länge von 65 km das Feste Fahrbahn System RHEDA 2000® verwendet, wobei Unter‐ und Oberbau als flache Betonplatten ausgebildet sind, welche durch Befestigungselemente verbunden werden müssen. Im Beitrag wird erläutert, wie diese Elemente auf die Anforderungen des Projektes hin entwickelt wurden. Mit umfangreichen Versuchen mußte nachgewiesen werden, daß die vorgeschlagenen Elemente alle Spezifikationen bezüglich Tragfähigkeit, Gebrauchstauglichkeit und Ermüdung erfüllen. Zur Ermittlung der Ermüdungsfestigkeit wurde die Wöhlerkurve ermittelt.
Langzeithaftfestigkeit zwischen Alt‐ und Aufbeton bei unterschiedlichen Klimabedingungen
Authors: Beushausen Hans‐Dieter , Dehn Frank , Alexander Mark 
Published: May 2005

AbstractDie Haftung und Verträglichkeit zwischen Alt‐ und Aufbeton ist häufig das entscheidende Kriterium für die Dauerhaftigkeit und somit den Erfolg einer Sanierungsmaßnahme. In der Regel wird eine hohe Kurzeithaftfestigkeit erreicht, währenddessen zu einem späteren Zeitpunkt häufig eine Ablösung des Aufbetons vom Untergrund zu beobachten ist. Die Gründe hierfür liegen neben der falschen Bauausführung in unzureichenden Bemessungsgrundlagen in Hinblick auf die Verträglichkeit zusammengesetzter Systeme unter verschiedenen, vor allem wechselnden Umweltbedingungen. Zur Erfassung unterschiedlicher klimatischer Bedingungen wurde in einem gemeinsamen Forschungsvorhaben zwischen den Universitäten Kapstadt und Leipzig überprüft, inwieweit die Langzeithaftfestigkeit und die Verträglichkeit zwischen Altbeton und verschiedenen Aufbetonen unter wechselnden Umwelteinflüssen gewährleistet werden kann.
Philosophie des neuen DBV/BDZ‐Merkblattes “Sichtbeton”
Authors: Litzner Hans‐Ulrich , Goldammer Klaus‐Reiner 
Published: May 2005

AbstractIm August 2004 hatten der Deutschen Beton‐ und Bautechnik‐Verein E.V. (DBV) und der Bundesverband der Deutschen Zementindustrie e.V. (BDZ) nach 1977 und 1997 die dritte Auflage des Merkblattes “Sichtbeton” herausgegeben. Es definiert erstmalig vier Sichtbetonklassen SB 1 bis SB 4, die sich durch Anforderungen an die Textur, die Porigkeit, an die Farbtongleichmäßigkeit, die Ebenheit sowie an die Qualität von Arbeits‐ und Schalhautfugen unterscheiden. Weitere Anforderungen betreffen Erprobungsflächen und die Qualität der Schalhaut.Im Hauptteil des Merkblattes werden Hinweise zur Planung und Ausschreibung von Sichtbetonflächen sowie zu deren Ausführung gegeben. Sie basieren auf Erfahrungen, die in letzter Zeit an markanten Sichtbetonbauwerken gesammelt wurden. Ein abschließendes Kapitel beinhaltet die Beurteilung von Sichtbetonflächen nach deren Herstellung. Hier gilt der Grundsatz, daß der Gesamteindruck das primäre und maßgebende Kriterium ist.
Arbeitsfugen in Bauteilen aus Selbstverdichtendem Beton (SVB)
Authors: Fingerloos Frank 
Published: May 2005

AbstractFür die Bemessung von Bauteilen aus Selbstverdichtendem Beton kann die DIN 1045‐1 [1] mit wenigen Änderungen und Ergänzungen verwendet werden. Diese Anpassungen werden in der DAfStb‐Richtlinie Selbstverdichtender Beton (SVB‐Richtlinie), Ausgabe November 2003 [3], geregelt.Für die Schubkraftübertragung in Fugen wird in [3] ergänzt, daß die unbehandelte Oberfläche des SVB generell als sehr glatt anzusehen ist. Diese verschärfende, konservative Festlegung hat für die Bemessung und Ausführung von Arbeitsfugen in SVB gravierende Konsequenzen.
Zur Bemessung von Konsolen mit Stabwerkmodellen: Eine Stellungnahme zum Beitrag von Roeser und Hegger von Heft 5, S. 434–439: Zur Bemessung von Konsolen gemäß DIN 1045‐1 und DAfStb Heft 525
Authors: Reineck Karl‐Heinz , Fitik Birol 
Published: May 2005

AbstractUnstrittig ist, daß die Bemessung von Konsolen mit Stabwerkmodellen erfolgen sollte und somit Abschn. 10.6.3 der DIN 1045‐1 zur Anwendung kommt. Die im Beitrag von Roeser und Hegger als Beleg für bei diesem Vorgehen auftretenden Unsicherheiten angeführten Versuche werden untersucht und die Versagensursachen nach den Versuchsberichten angegeben. Es zeigt sich, daß der Anordnung und Menge der senkrechten Bügel eine entscheidende Bedeutung zukommt und mit Stabwerkmodellen erklärt werden kann, warum bei einigen Versuchen nicht die volle Tragfähigkeit erreicht wurde. Diese Versuche liefern keinen Beleg gegen eine konsequente Bemessung von Konsolen mit Stabwerkmodellen.
Durchbiegungsberechnung an Stahlbetonträgern oder Schlankheitsnachweis? Richtigstellung und Ergänzung
Authors: Steiner Josef , Fricke Karl‐Ludwig 
Published: May 2005

AbstractZuschrift zu Fricke, K.‐L.: Durchbiegungsberechnung an Stahlbetonträgern oder Schlankheitsnachweis? Beton‐ und Stahlbetonbau 99 (2004), Heft 1, S. 52‐55, und Erwiderung.
Carbohydrates in peptide and protein design
Authors: Jensen Knud J. , Brask Jesper 
Published: May 2005

AbstractMonosaccharides and amino acids are fundamental building blocks in the assembly of nature's polymers. They have different structural aspects and, to a significant extent, different functional groups. Oligomerization gives rise to oligosaccharides and peptides, respectively. While carbohydrates and peptides can be found conjoined in nature, e.g., in glycopeptides, the aim of this review is the radical redesign of peptide structures using carbohydrates, particularly monosaccharides and cyclic oligosaccharides, to produce novel peptides, peptidomimetics, and abiotic proteins. These hybrid molecules, chimeras, have properties arising largely from the combination of structural characteristics of carbohydrates with the functional group diversity of peptides. This field includes de novo designed synthetic glycopeptides, sugar (carbohydrate) amino acids, carbohydrate scaffolds for nonpeptidal peptidomimetics of cyclic peptides, cyclodextrin functionalized peptides, and carboproteins, i.e., carbohydrate‐based proteinmimetics. These successful applications demonstrate the general utility of carbohydrates in peptide and protein architecture. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 80: 747–761, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Synthesis and screening of a small library of proline‐based biodendrimers for use as delivery agents
Authors: Sanclimens Glòria , Shen Hong , Giralt Ernest , Albericio Fernando , Saltzman Mark William , Royo Miriam 
Published: May 2005

AbstractA small library of defined peptide dendrimers based on polyproline sequences was designed to demonstrate the feasibility of generating a new type of polymeric agent for therapeutic use. Structural modifications to dendrimer surfaces further enriched the diversity of the library. Data show that the prolinerich dendrimers can be internalized in human epithelial (HeLa) cells, demonstrating the importance of the dendrimeric motif. The promising results described herein suggest that controlled modification of the dendrimer surface should eventually yield proline dendrimers with therapeutic potential. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 80: 800–814, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Fluorescence intensity decays of cyclohexane and methylcyclohexane with two‐photon excitation from a high repetition rate frequency‐doubled dye laser
Authors: Lakowicz Joseph R. , Gryczynski Ignacy 
Published: May 2005

AbstractWe observed fluorescence emission from cyclohexane (CH) and methylcyclohexane (MCH) using picosecond pulses at 298–300 nm from a frequency‐doubled cavity‐dumped R6G dye laser. The emission maxima for CH and MCH are 209 and 215 nm, respectively, which agree with previous studies using vacuum ultra‐violet (VUV) excitation near 150 nm. The fluorescence intensities depended quadratically on peak laser intensity indicating two‐photon excitation. The intensity decays resulting from two‐photon excitation were measured using frequency‐domain fluorometry and were found to be nearly singly exponential ranging from 0.59 to 0.80 ns. Two‐photon induced fluorescence of cyclic and linear alkanes may provide new intrinsic spectroscopic probes of biological molecules. © 1995 John Wiley & Sons, Inc.
The active site of bacteriorhodopsin. Two‐photon spectroscopic evidence for a positively charged chromophore binding site mediated by calcium
Authors: Stuart Jeffrey A. , Vought Bryan W. , Zhang Chian‐Fan , Birge Robert R. 
Published: May 2005

AbstractThe nature of the chromophore binding site of light‐adapted bacteriorhodopsin is analyzed by using all‐valence electron MNDO and MNDO‐PSDCI molecular orbital theory to interpret previously reported linear and nonlinear optical spectroscopic measurements. A total of 45 binding site models are investigated. The binding site is simulated by including the chromophore, the lysine residue (LYS216), the following nearby amino acids (ARG82, ASP85, ASP115, ASP212, THR90, TRP86, TRP138, TRP182, TYR57, TYR83, and TYR185) and zero, one, or two divalent cations. We conclude that the unique two‐photon properties of the chromophore are due in part to the electrostatic field associated with a Ca2+ ion near to the chromophore. Four amino acids and three water molecules contribute significantly to the assigned chromophore adjacent calcium binding site (ASP85, ASP212, TYR57 and TYR185), and two conformational minima are predicted. The higher energy conformation has the calcium ion stabilized primarily by ASP85 and the chromophore imine proton by ASP212. The lower energy conformation has the calcium ion stabilized primarily by ASP212 and the imine proton by ASP85. The latter configuration is more stable due to strong hydrogen bonding between TYR185 and ASP212 coupled with electrostatic stabilization of the divalent cation by TYR57. Although both tyrosine residues are predicted to exhibit some “unprotonated” character, models involving full deprotonation of either TYR57 or TYR185 do not fit the spectroscopic data. We conclude that the cation binding site identified in this study is the second high affinity binding site for calcium, and that the chromophore binding site is, to a first approximation, positively charged. The chromophore “1B” and “1A” states, despite extensive mixing, exhibit significantly different configurational character. The lowest‐lying “1B” state is dominated by single excitations (> 80% for all models studied) whereas the second‐excited “1A” state is dominated by double excitations (> 70% for all models studied with extensive participation by spin‐coupled triplet‐triplet excitations). © 1995 John Wiley & Sons, Inc.
Palaeodental studies using FT‐Raman spectroscopy
Authors: Edwards H. G. M. , Williams A. C. , Farwell D. W. 
Published: May 2005

AbstractThe FT‐Raman vibrational spectrum of a child's deciduous exfoliated tooth has been analysed and the spectral features assigned to hydroxyapatite and protein. Comparisons made with older teeth from a Romano‐British burial site (∼ 2k years) and fossilised animal teeth (∼ 1 M‐70 M years) indicate that the organic protein component has disappeared with interment, whereas spectroscopic features due to the inorganic phosphatic matrix are common to all samples, modern and ancient. The application of the technique to the non‐destructive analysis of archaeological samples and the recording of spectra from interred samples without detriment from fluorescent material is demonstrated. © 1995 John Wiley & Sons, Inc.
A comparative infrared spectroscopic study of human breast tumors and breast tumor cell xenografts
Authors: Fabian Heinz , Jackson Michael , Murphy Leigh , Watson Peter H. , Fichtner Iduna , Mantsch Henry H. 
Published: May 2005

AbstractFourier transform infrared spectroscopy has been applied to the study of human breast tumors, human breast tumor cell lines and xenografted human tumor cells. The results presented indicate that substantial differences exist on a macroscopic level between human tumors, xenografted tumors and human tumor cell lines, which are related to the presence of a significant connective tissue matrix in the tumors. On a macroscopic level tumor cell xenografts appear, in spectroscopic terms, to be relatively homogeneous with a relatively weak signature characteristic of connective tissue. Differences on a microscopic level between adjacent small (30 μm2) areas of the same xenografted tumor could be detected, which were due to local variations in collagen content. In addition to variations in collagen content, variation in the deposition of microscopic fat droplets throughout both human and xenografted tumors could be detected. These results indicate the care with which infrared spectroscopic studies of tissues must be carried out to avoid incorrect interpretation of results due to an incomplete understanding of tissue pathology. © 1995 John Wiley & Sons, Inc.
A comparative study of the binding effects of Mg2+, Ca2+, Sr2+, and Cd2+ on calmodulin by fourier‐transform infrared spectroscopy
Authors: Nara Masayuki , Tanokura Masaru , Yamamoto Tatsuyuki , Tasumi Mitsuo 
Published: May 2005

AbstractFourier‐transform infrared spectroscopy is applied to examine interactions between divalent metal ions (M2+) and the COO− groups in the M2+‐binding sites of calmodulin as well as effects of M2+ binding on the main chain conformation. Bands due to the symmetric and antisymmetric stretches of the COO− groups in the amino‐acid side chains give information on the coordination of the COO− groups to M2+, and the amide‐I' bands are useful for studying changes in the secondary structure of the protein main chain upon M2+ binding. Infrared deconvolved spectra as well as second‐derivative spectra are sensitive to structural differences among the M2+‐bound forms (M2+ = Mg2+, Ca2+, Sr2+, and Cd2+). Bands at about 1658, 1553, and 1424 cm−1 are characteristic of the Ca2+‐bound form, and are called, respectively, marker bands I, II, and III of the active‐type protein. The Sr2+‐ and Cd2+‐bound forms show deconvolved and second‐derivative spectra similar to those of the Ca2+‐bound form, whereas the Mg2+‐bound form gives second‐derivative and deconvolved spectra close to those of the inactive M2+‐free form. Broad parallelism is found to exist between the marker‐band intensities of the M2+‐bound forms and the abillities of M2+ to stimulate calmodulin‐dependent phosphodiesterase activity. Assignments of the marker bands are discussed. © 1995 John Wiley & Sons, Inc.