bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Characterization, and X‐Ray Crystal Structures of Bis[N‐(3,3‐diphenylallylidene)quinolin‐8‐amine‐κN,κN8]copper(1+) Tetraphenylborate(1−) ([Cu(dpa‐qa)2]BPh4) and Bis[N,N′‐bis(3,3‐diphenylallylidene)‐[1,1′‐biphenyl]‐2,2′‐diamine‐κN,κN′]copper(1+) Perchlorate ([Cu(bdpa‐bda)2]ClO4 ⋅ 3 H2O)
Authors: Amirnasr Mehdi , Kickelbick Guido , Dehghanpour Saeed
Published: February 2006

Two new ligands, N‐(3,3‐diphenylallylidene)quinolin‐8‐amine (dpa‐qa; L1) and N,N′‐bis‐(3,3‐diphenylallylidene)[1,1′‐biphenyl]‐2,2′‐diamine (bdpa‐bda; L2), and their corresponding copper(I) complexes, [Cu(dpa‐qa)2]BPh4 (1) and [Cu(bdpa‐bda)2]ClO4 ⋅ 3 H2O (2), were synthesized and characterized by C,H,N analyses, 1H‐ and 13C‐NMR, IR, and UV/VIS spectroscopy. The crystal and molecular structures of 1 and 2 were determined by X‐ray crystallography from single‐crystal data. Complex 1 crystallizes in the orthorhombic space group Pbca, with a = 14.391(3) Å, b = 21.967(5) Å, c = 35.463(8) Å, V = 11211(4) Å3, and Z = 8. Complex 2 crystallizes in the monoclinic space group C2/c, with a = 30.746(10) Å, b = 18.244(6) Å, c = 27.835(9) Å, β = 109.794(7)°, V = 14691(8), and Z = 8. The coordination polyhedron about the CuI center in the two complexes is best described as a distorted tetrahedron. A quasireversible redox behavior is observed for complex 1 and 2 (E1/2 = 0.58 and 1.04 V).
A New Lignan and Four New Lignan Glycosides from Mananthes patentiflora
Authors: Tian Junmian , Hao Xiaojiang , He Hongping
Published: February 2006

A new lignan, 5‐hydroxyjusticidin A (= 9‐(1,3‐benzodioxol‐5‐yl)‐5‐hydroxy‐4,6,7‐trimethoxynaphtho[2,3‐c]furan‐1(3H)‐one; 1), and four new diphyllin‐type lignan glycosides, mananthosides C–F (2–5), containing glucosyl (Glc), arabinosyl (Ara), galactosyl (Gal), and/or apiosyl residues, have been isolated from Mananthes patentiflora, together with five known compounds. Their structures and configurations were elucidated by in‐depth 1D‐ and 2D‐NMR experiments, as well as MS analysis.
Facile One‐Pot Three‐Component Synthesis of Functionalized Pyridylfuran‐2‐amines
Authors: Adib Mehdi , Sayahi Mohammad Hosein , Koloogani Somayeh Aali , Mirzaei Peiman
Published: February 2006

The reactive 1 : 1 zwitterionic intermediates generated in situ from the reaction between a series of isocyanides and diaroylacetylenes were trapped by pyridine carbaldehydes to yield highly functionalized 5‐pyridylfuran‐2‐amines in good yields (82–93%).
Synthesis of a Phosphorylated Disaccharide Fragment of the O‐Specific Polysaccharide of Vibrio cholerae O139, Functionalized for Conjugation
Authors: Ruttens Bart , Kováč Pavol
Published: February 2006

The title disaccharide, 2‐{2‐{2‐[(2‐ethoxy‐3,4‐dioxocyclobut‐1‐en‐1‐yl)amino]ethoxy}ethoxy}ethyl 2‐O‐(3,6‐dideoxy‐α‐L‐xylo‐hexopyranosyl)‐β‐d‐galactopyranoside cyclic 4,6‐(potassium phosphate) (2), was synthesized from the two isomeric linker‐equipped galactose acceptors 9 and 10, obtained by phosphorylation of 2‐[2‐(2‐azidoethoxy)ethoxy]ethyl 3‐O‐benzyl‐β‐d‐galactopyranoside (8), which were glycosylated with ethyl 2,4‐di‐O‐benzyl‐3,6‐dideoxy‐1‐thio‐β‐l‐xylo‐hexopyranoside (12; Scheme). Mainly the fully protected α‐(1 → 2)‐linked products 13α and 14α were formed. Catalytic hydrogenolysis/hydrogenation effected global deprotection, thereby removing the chirality at the P‐atom, and simultaneously converted the azido group in the linker to an amino group (→ 15). Final treatment with diethyl squarate (= 3,4‐diethoxycyclobut‐3‐ene‐1,2‐dione) gave target compound 2, amenable for conjugation to proteins.
Hierarchic Supramolecular Interactions within Assemblies in Solution and in the Crystal of 2,3,6,7‐Tetrasubstituted 5,5′‐(Anthracene‐9,10‐diyl)bis[pyrimidin‐2‐amines]
Authors: Balaban Teodor Silviu , Eichhöfer Andreas , Krische Michael J. , Lehn Jean‐Marie
Published: February 2006

The title compounds 6 and 7 were synthesized in good yield (Schemes 1 and 2), and their mode of assembly was studied both in solution, for the tetrakis(decyloxy) derivative 6, and in the crystal, for the tetramethoxy analogue 7. The pyrimidin‐2‐amine moieties of 6 and 7 can engage in three different supramolecular interactions: i) metal ligation via one of the pyrimidine N‐atoms, ii) cooperative double H‐bonding via the NH2 group, and iii) π–π‐stacking interactions. In solution, coordination of the central Zn‐atom within the soluble porphyrinatozinc complex 19 leads to significant changes in the NMR and absorption spectra of 6. In the absence of metal ligation, the next strongest interaction is H‐bonding which can operate in nonpolar or moderately polar solvents. In these cases, however, no stacking interaction or inclusion compounds could be put into evidence in the case of 6 by absorption, fluorescence, or NMR spectroscopies. The π‐stacking interactions were only observed in the crystal of 7 in conjunction with double H‐bonding. Slightly disordered DMSO molecules are also H‐bonded to the NH2 groups of 7, perturbing the expected packing. The present study illustrates some of the challenges inherent to directing hierarchical assembly processes in the solid state.
Transformation of 5‐Hydroxy‐ to (5‐Chloropentanoyl)amino Derivatives under ‘Direct Amide Cyclization’ Conditions
Authors: Iliev Boyan , Verma Sanjiv , Linden Anthony , Heimgartner Heinz
Published: February 2006

The application of the ‘direct amide cyclization’ conditions to the linear δ‐hydroxy diamide 11 is described (Scheme 3). Instead of the cyclization to the expected nine‐membered cyclodepsipeptide, only the chloro acid 12 was obtained. Its formation could be explained by consecutive formation of the 1,3‐oxazol‐5(4H)‐one 16 and the six‐membered imino lactone 17 as intermediates (Scheme 4). The spontaneous isomerization of the latter gave 12 in a good yield.
Under the microscope: the structure of the foreign exchange market
Authors: Sager Michael J. , Taylor Mark P.
Published: February 2006

We provide a detailed, up‐to‐date description of the microstructure of the foreign exchange market and of the behaviour of participant groups. In the light of this, we highlight shortcomings in existing theoretical models of market interaction and present an outline alternative model that marries theoretical prediction and current market practice. Copyright © 2006 John Wiley & Sons, Ltd.
Understanding order flow
Authors: Evans Martin D. D. , Lyons Richard K.
Published: February 2006

This paper develops a model for understanding end‐user order flow in the FX market. The model addresses several puzzling findings. First, the estimated price‐impact of flow from different end‐user segments is, dollar‐for‐dollar, quite different. Second, order flow from segments traditionally thought to be liquidity‐motivated actually has power to forecast exchange rates. Third, about one‐third of order flow's power to forecast exchange rates 1 month ahead comes from flow's ability to forecast future flow, whereas the remaining two‐thirds applies to price components unrelated to future flow. We show that all of these features arise naturally from end‐user heterogeneity, in a setting where order flow provides timely information to market‐makers about the state of the macro‐economy. Copyright © 2006 John Wiley & Sons, Ltd.
Explaining trading volume in the euro
Authors: Brzeszczynski Janusz , Melvin Michael
Published: February 2006

Following the introduction of the euro in 1999, daily trade volume began a downward trend until early 2002, after which daily volume started to trend upward. A model of weekly trades suggests that changes in momentum as well as the carry trade motives of interest differentials are significant explanatory factors. Daily data examination reveals that Fridays have lower activity, and Tuesdays greater activity than average. At the intradaily level, trading is very low before and after London business hours. Within the London business day, trade activity is higher in 5‐min intervals when a ‘big figure’ is breached. This is consistent with stop‐loss or take‐profit motives for trading. Copyright © 2006 John Wiley & Sons, Ltd.
Activation of cell‐survival transcription factor NFκB in L1Ig6‐stimulated endothelial cells
Authors: Reidy Martin , Zihlmann Pius , Hubbell Jeffrey A. , Hall Heike
Published: February 2006

Ligation of the integrin αvβ3 in endothelial cells has been shown to be important for their survival. Such ligation induces signalling events merging into the Raf‐Ras‐ERK cascade that eventually induces activation of nuclear factor kappa B (NFκB), leading to its phosphorylation and nuclear translocation and thus inhibiting apoptosis. Here, the recombinant sixth immunoglobulin‐like domain of cell adhesion molecules L1 (L1Ig6), a ligand for integrin αvβ3, was explored as a component of vascular implant surfaces to initiate the NFκB‐cell survival pathway. This supposition was supported. Specifically, NFκB‐p65 was expressed in human umbilical vein endothelial cells (HUVECs) and when stimulated on L1Ig6, the phosphorylated form was found in the nucleus in over 60% of the cells. NFκB was not translocated into the nucleus on a number of other extracellular matrix substrates examined or when fibroblasts were cultured on L1Ig6. NFκB phosphorylation and nuclear translocation could be inhibited by blocking ligation of αvβ3 by L1Ig6 with an antibody recognizing αvβ3, with a cyclic RGD peptide, and with soluble L1Ig6. Moreover, blocking of αvβ3 interaction with L1Ig6 was correlated with induction of apoptosis. Thus, these experiments demonstrate that L1Ig6 may be useful as αvβ3 ligand for the induction of endothelial survival pathways mediated by NFκB‐p65. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Energetics of osmoregulation: I. oxygen consumption by Fundulus heteroclitus
Authors: Kidder George W. , Petersen Christopher W. , Preston Robert L.
Published: February 2006

We have developed a flow‐through method for measuring oxygen consumption in fish which allows continuous monitoring over periods of days with good accuracy. Our goal was to determine the changes in basal metabolic rate in estuarine fish as a function of salinity. We show that in Fundulus heteroclitus, the oxygen consumption drops by 50% during the first 12 hr in the respirometer, as the fish cease exploratory movements. We have determined the influence of temperature and body size on resting respiratory rate, but failed to find any circadian or tidal rhythm in aerobic respiration. With these variables controlled, we determined that changing from 10 to 30 ppt water had no demonstrable effect on oxygen uptake. Since there must be a large change in osmotic flux due to this change in salinity, it appears that the fish might be diverting energy from other uses rather than increasing aerobic energy production to meet the increased osmoregulatory work load. J. Exp. Zool. 305A:309–317, 2006. © 2006 Wiley‐Liss, Inc.
Effect of protein kinase C inhibitors on porcine oocyte activation
Authors: Sedmíková Markéta , Rajmon Radko , Petr Jaroslav , Švestková Dana , Chmelíková Eva , Akal Astatike Bantirgu , Rozinek JIří , Jílek František
Published: February 2006

The effect of protein kinase C (PKC) inhibitors on porcine oocyte activation by calcium ionophore A23187 was studied. Calcium ionophore applied in a 50 µM concentration for 10 min induced activation in 74% of oocytes matured in vitro. When the ionophore‐treated oocytes were exposed to the effect of bisindolylmaleimide I, which inhibits calcium‐dependent PKC isotypes (PKC‐α, ‐βI, ‐βII, ‐γ,) and calcium‐independent PKC isotypes (PKC‐δ, ‐ε), the portion of activated oocytes decreased (at a concentration of 100 nM, 2% of the oocytes were activated). Go6976, the inhibitor of calcium‐dependent PKC isotypes PKC‐α, ‐βI did not prevent the action of the oocytes treated with calcium ionophore in concentrations from 1 to 100 µM. The inhibitor of PKC‐βI and βII isotypes, hispidin, in a concentration of 2 µM–2 mM, was not effective either. The inhibitor of PKC‐δ isotype, rottlerin, suppressed activation of the oocytes by calcium ionophopre (no oocyte was activated at 10 µM concentration). The PKC‐δ isotype in matured porcine oocytes, studied by Western blot analysis, appeared as nontruncated PKC‐δ of 77.5 kDa molecular weight, on the one hand, and as truncated PKC‐δ, which was present in the form of a doublet of approximately 62.5 and 68 kDa molecular weight, on the other hand. On the basis of these results, it can be supposed that PKC participates in the regulation of processes associated with oocyte activation. Calcium‐dependent PKC‐α, ‐β isotypes do not seem to play any significant role in calcium activation. The activation seems to depend on the activity of the calcium‐independent PKC‐δ isoform. J. Exp. Zool. 305A:376–382, 2006. © 2006 Wiley‐Liss, Inc.
Effect of prevention of lung inflation on metamorphosis and respiration in the developing bullfrog tadpole, Rana catesbeiana
Authors: Gdovin Matthew J. , Jackson Vonnie V. , Zamora Debora A. , Leiter James C.
Published: February 2006

We tested the hypothesis that respiratory development would be retarded in tadpoles reared in aquaria in which a barrier prevented access to the air–water interface. To test this hypothesis, we examined swimming behavior and respiration in intact tadpoles and gill and lung respiratory activity and central chemosensory responses in an in vitro brainstem preparation. The “barrier” tadpoles had significantly lower resting gill frequencies and higher lung breath attempts than control tadpoles at the same metamorphic stage. Control tadpoles swam greater distances and spent more time in the upper one third of the aquaria, while barrier tadpoles spent significantly more time at the bottom of the aquaria. There was significantly greater mortality for barrier tadpoles compared to control animals in the earliest and latest metamorphic stages. Mean body weight was significantly greater, and metamorphic rate was reduced in barrier tadpoles. Neither control nor barrier tadpole brainstem preparations demonstrated a gill ventilatory response to CO2; however, both control and barrier preparations possessed significant lung frequency responses to central CO2 chemoreceptor stimulation. Bath application of the GABAA and glycine receptor antagonists, bicuculline and strychnine, had greater effects on control tadpole gill burst activity and produced a similar large‐amplitude bursting pattern in both control and barrier tadpoles, that was insensitive to CO2 chemoreceptor stimulation. We conclude that development of the respiratory pattern was perturbed by the barrier, but the major effect was on gill ventilation rather than lung ventilation as we had expected. J. Exp. Zool. 305A:335–347, 2006. © 2006 Wiley‐Liss, Inc.
Astrocyte–neuron vulnerability to prenatal stress in the adult rat brain
Authors: Barros Virginia G. , Duhalde‐Vega Maite , Caltana Laura , Brusco Alicia , Antonelli Marta C.
Published: February 2006

Chronic activation of the stress response during pregnancy has been shown to be injurious to the development of the offspring. We have previously demonstrated that restraint prenatal stress inflicted during the last week of pregnancy in rats increased dopamine and glutamate receptors in forebrain areas of the adult offsprings. In this study, the same prenatal insult was employed to assess morphological changes in astrocytes and in the dendritic arborization in frontal cortex, striatum, and hippocampus of the adult rat brain. On postnatal day 90, brains were processed for immunocytochemistry using primary antibodies to glial fibrillary acidic protein (GFAP; the main cytoskeletal astroglial protein), S100B protein (an astroglial‐derived neurotrophic factor), MAP‐2 (a microtubule‐associated protein present almost exclusively in dendrites), and synaptophysin (Syn; one major integral protein of the synaptic vesicles membrane). The results show a significant increase in the cell area of GFAP‐immunoreactive (‐IR) astrocytes, with high levels of S100B protein and a significant decrease in the relative area of MAP‐2‐IR neuronal processes in prenatally stressed adult rats. The expression of synaptophysin decreased in all areas studied. These results demonstrate that prenatal stress induces a long‐lasting astroglial reaction and a reduced dendritic arborization, with synaptic loss in the brain of adult offspring. In addition to the neurochemical alterations previously reported, these morphological changes might be underlying the behavioral and learning impairment previously observed in prenatally stressed rats. © 2006 Wiley‐Liss, Inc.
Specificity and divergence in the neurobiologic effects of different metallothioneins after brain injury
Authors: Penkowa Milena , Tio Laura , Giralt Mercedes , Quintana Albert , Molinero Amalia , Atrian Silvia , Vašák Milan , Hidalgo Juan
Published: February 2006

Brain injury and neuroinflammation are pathophysiologic contributors to acute and chronic neurologic disorders, which are progressive diseases not fully understood. Mammalian metallothioneins I and II (MT‐I&II) have significant neuroprotective functions, but the precise mechanisms underlying these effects are still unknown. To gain insight in this regard, we have evaluated whether a distant, most likely single‐domain MT (Drosophila MTN) functions similarly to mammalian MT‐I&II (recombinant mouse MT‐I and human MT‐IIa and native rabbit MT‐II) after cryogenic injury to the cortex in Mt1&2 KO mice. All the recombinant proteins showed similar neuroprotective properties to native MT‐II, significantly reducing brain inflammation (macrophages, T cells, and pro‐inflammatory cytokines), oxidative stress, neurodegeneration, and apoptosis. These results in principle do not support specific protein–protein interactions as the mechanism underlying the neuroprotective effects of these proteins because a non‐homologous and structurally unrelated MT such as Drosophila MTN functions similarly to mammalian MTs. We have also evaluated for the first time the neurobiologic effects of exogenous MT‐III, a major CNS MT isoform. Human rMT‐III, in contrast to human nMT‐IIa, did not affect inflammation, oxidative stress, and apoptosis, and showed opposite effects on several growth factors, neurotrophins, and markers of synaptic growth and plasticity. Our data thus highlight specific and divergent roles of exogenous MT‐III vs. the MT‐I&II isoforms that are consistent with those attributed to the endogenous proteins, and confirm the suitability of recombinant synthesis for future therapeutic use that may become relevant to clinical neurology. © 2006 Wiley‐Liss, Inc.
Second harmonic generation in left-handed metamaterials
Authors: Popov A K , Slabko V V , Shalaev V M
Published: February 2006

The extraordinary properties of second harmonic
generation in negative-index metamaterials, where the Poynting
vector and the wavevector have opposite directions are
investigated. The "backward" phase-matching condition results in
significant changes in the Manley-Rowe relations and in spatial
distributions of the field intensities of the coupled waves.
Improvement of port wine stain laser therapy by skin preheating prior to cryogen spray cooling: A numerical simulation
Authors: Jia Wangcun , Aguilar Guillermo , Verkruysse Wim , Franco Walfre , Nelson J. Stuart
Published: February 2006

Background and Objectives

Although cryogen spray cooling (CSC) in conjunction with laser therapy has become the clinical standard for treatment of port wine stain (PWS) birthmarks, the current approach does not produce complete lesion blanching in the vast majority of patients. The objectives of this study are to: (1) experimentally determine the dynamic CSC heat flux when a skin phantom is preheated, and (2) numerically study the feasibility of using skin preheating prior to CSC to improve PWS laser therapeutic outcome.

Study Design/Materials and Methods

A fast‐response thin‐foil thermocouple was used to measure the surface temperature and thus heat flux of an epoxy skin phantom during CSC. Using the heat flux as a boundary condition, PWS laser therapy was simulated with finite element heat diffusion and Monte Carlo light distribution models. Epidermal and PWS blood vessel thermal damage were calculated with an Arrhenius‐type kinetic model.

Results

Experimental results show that the skin phantom surface can be cooled to a similar minimum temperature regardless of the initial temperature. Numerical simulation indicates that upon laser irradiation, the epidermal temperature increase is virtually unaffected by preheating, while higher PWS blood vessel temperatures can be achieved. Based on the damage criterion we assumed, the depth and maximum diameter of PWS vessels that can be destroyed irreversibly with skin preheating are greater than those without.

Conclusions

Skin preheating prior to CSC can maintain epidermal cooling while increasing PWS blood vessel temperature before laser irradiation. Numerical models have been developed to show that patients may benefit from the skin preheating approach, depending on PWS vessel diameter and depth. Lasers Surg. Med. 38:155–162, 2006. © 2006 Wiley‐Liss, Inc.
Direct Ion Exchange Self‐Metallization: A Novel and Efficient Route for the Preparation of Double‐Surface‐Silvered Polyimide Films
Authors: Qi Shengli , Wu Dezhen , Bai Zongwu , Wu Zhanpeng , Yang Wantai , Jin Riguang
Published: February 2006

Summary: Silvered polyimide films have been fabricated by direct ion exchange of a damp‐dry poly(amic acid) film with an aqueous silver solution such as silver nitrate. Thermal curing of the silver(I)‐containing films under tension leads to cycloimidization of the poly(amic acid) into polyimide with a concomitant silver(I) reduction and aggregation at both film sides to give reflective and conductive double‐surface‐silvered polyimide films. The metallized films retain the essential properties of the parent polyimide.

Surface morphology of the prepared double‐surface‐silvered polyimide films.

magnified image

Surface morphology of the prepared double‐surface‐silvered polyimide films.
Innovationen durch PACVD Duplex Schichtsysteme im Leichtmetall‐Druckguss
Authors: Klimek K. S. , Gebauer‐Teichmann A. , Röders G. , Kaestner P. , Rie K.‐T.
Published: February 2006

Duplex‐PACVD Hartstoff‐Beschichtungen haben sich bereits bewährt zur Standzeiterhöhung von Werkzeugen im Hinblick auf Adhäsion, Verschleiß, Ermüdung und Korrosion von Stahl.

Die Entwicklung der Synthese von Duplex nanostrukturierten und gradierten Schichtsystemen basierend auf Boriden und Nitriden des Titans wird beschrieben. Ziel dieser Untersuchung ist die Optimierung der Oberflächeneigenschaften mittels Neu‐ bzw. Weiterentwicklung und Kombination von Plasmaoberflächenprozessen: Duplex‐Prozess und Gradientenschichten.

Insbesondere Duplex‐Hartstoffschichten werden hier im PACVD‐Verfahren abgeschieden und im Hinblick auf ihre tribologischen Eigenschaften untersucht und im Aluminium‐ und Magnesiumdruckguss eingesetzt. Gleichzeitig werden Sprühmittelmengen und Formaushebeschrägen reduziert. Praktische Tests wurden von Automobilherstellern und Zulieferern durchgeführt. Alle Beschichtungen auf Druckgusswerkzeugen zeigten eine deutliche Standzeiterhöhung und geringere Metallanklebungstendenz. Beschichtete Werkzeuge waren bei geringerer Trennmittelmenge den unbeschichteten Werkzeugen bei ursprünglicher Trennmittelmenge überlegen. Die Wirtschaftlichkeit beschichteter Druckgusswerkzeuge konnte bewiesen werden.
Rost‐ und säurebeständige Stähle unter Komplexbeanspruchung
Authors: Ellermeier J. , Gugau M. , Scholz M. , Berger C. , Schlücker E. , Depmeier L.
Published: February 2006

Die Schwingungsrisskorrosionsbeständigkeit zweier Stähle (Superaustenit (1.3974) und ein Duplexstahl (1.4462)) wurde anhand von Zugschwell‐, Umlaufbiege‐, Scheiteldruckschwell‐ und Innendruckschwellversuchen vergleichend untersucht. Die Untersuchungen wurden in 10 % Salpetersäure, in künstlichem Meerwasser nach DIN 50905 und in den beiden für die Praxis besonders relevanten Medien Kaliumjodidlösung und H2S‐begastem künstlichen Meerwasser nach DIN 50905 und zum Vergleich in säurefreiem Spindelöl durchgeführt. Die Ergebnisse belegen, dass der Werkstoff 1.3974 unter ein‐ und dreiachsiger Beanspruchung bis 107 Schwingspiele eine deutlich höhere Schwingungsrisskorrosionsbeständigkeit als der Werkstoff 1.4462 aufweist. Es wurde ein Korrosionsfaktor ermittelt, der das Verhältnis aus den Versuchen in den korrosiven Medien im Vergleich zu den Ergebnissen in säurefreiem Spindelöl beschreibt. In künstlichem Meerwasser nach DIN 50905 ergibt sich ein Faktor zwischen 0,67 und 0,92 in Abhängigkeit der Beanspruchung für den Werkstoff 1.4462. In 10 % Salpetersäure ergibt sich für den Werkstoff 1.4462 ein Faktor zwischen 0,67 und 0,83. Beim Werkstoff 1.3974 wird ein Faktor von 0,86‐1 in künstlichem Meerwasser nach DIN 50905 und von 0,70‐1,0 in 10 % Salpetersäure ermittelt.
Korrosionsuntersuchungen an mittels PVD mit Zn und Zn/Mn beschichteten Stählen
Authors: Wolf G. K. , Münz R.
Published: February 2006

Alternativ zur Schmelztauch‐ bzw. elektrogalvanischen Verzinkung von Stählen bieten sich Gasphasenabscheidungen (PVD) wegen ihrer Flexibilität bezüglich Legierungszusammensetzung und Umweltverträglichkeit an. Dabei muss ein PVD‐beschichteter Stahl mindestens die gleiche Korrosionsbeständigkeit besitzen wie die mit „klassischen”︁ Abscheideverfahren vergüteten Stähle.

Daher wurde für die Methode Elektronenstrahlaufdampfen auf niedrig legierte Stähle die Korrosionsresistenz von Zink‐ und Zink/Manganschichten, die z. T. ohne und z. T. mit Ionenstrahlunterstützung abgeschieden wurden, geprüft. Die Untersuchungen wurden mittels Salzsprühtest und elektrochemischen Potential/Zeitmessungen durchgeführt. Zunächst wurde die chemische und bestrahlungstechnische Vorbehandlung der Substrate und der Einfluss des Ionenbeschusses auf das Korrosionsschutzvermögen der Schichten unter die Lupe genommen. Dann wurde der Einfluss der Zinkschichtdicke im Vergleich mit einer 8μm dicken elektrogalvanischen Referenzzschicht beleuchtet. Schließlich wurden Zn/Mn‐Legierungen, Zn/Mn‐Multilagen und Zn‐Schichten mit Mn‐ oder Zn/Mn‐Deckschicht (Toplagen) untersucht.

Durch eine optimierte Vorbehandlung und Ionenunterstützung erhält man PVD‐Zinkschichten mit, unter Berücksichtigung der Schichtdicke, mit der Referenzschicht vergleichbarer Korrosionsresistenz. Als beste Mn‐haltige Schichten erwiesen sich die Toplagen, welche das Korrosionsschutzvermögen der Referenzschicht deutlich übertreffen.

Daneben wurde noch festgestellt, dass Potential/Zeitmessungen mit den Ergebnissen des Salzsprühtests in der Tendenz gut übereinstimmen.
Untersuchungen zur Wälzermüdung nach induktivem Kurzzeitanlassen
Authors: Scheerer H. , Berger C.
Published: February 2006

Induktiv randschichtgehärtete Komponenten werden zur Verbesserung der Bauteilzähigkeit, der Bearbeitbarkeit und zur Vermeidung von Verzug unter Betriebsbedingungen in den meisten Fällen zusätzlich im Ofen angelassen. In der Regel wird angelassen, wenn noch geschliffen werden soll. Entsprechend den Anlassbedingungen ändern sich der nach dem Härten vorliegende Gefügezustand und damit auch die Werkstofffestigkeit. Die hier durchgeführten Untersuchungen sollen zeigen, ob und bei welchen Temperaturen das bisherige Ofenanlassen durch induktives Kurzzeitanlassen ersetzt werden kann und wie sich diese Wärmebehandlung auf die Wälzermüdungseigenschaften auswirkt. Es konnte gezeigt werden, dass bei optimierten Kurzzeitanlassparametern Werkstoffzustände erreicht werden, welche sich bei Wälzbeanspruchung günstiger verhielten als Proben, welche im Ofen oder gar nicht angelassen wurden. Damit öffnet sich für zahlreiche Anwendungen die Möglichkeit, das bisherige Anlassen im Ofen durch das schnellere und kostengünstigere induktive Kurzzeitanlassen nach induktivem Randschichthärten zu ersetzen.
Enhanced γ‐glutamylcysteine synthetase activity decreases drug‐induced oxidative stress levels and cytotoxicity
Authors: Das Gokul C. , Bacsi Attila , Shrivastav Meena , Hazra Tapas K. , Boldogh Istvan
Published: February 2006

Multidrug resistance of cancer cells can be intrinsic or acquired and occurs due to various reasons, including increased repair of genotoxic damage, an enhanced ability to remove/detoxify chemical agents, or reactive oxygen species (ROS), and repression of apoptosis. Human A2780/100 ovarian carcinoma cells exhibit resistance to DNA cross‐linking agents, chlorambucil (Cbl), cisplatin (Cpl), melphalan (Mel), and ionizing radiation (IR) compared to the parental cell line, A2780. In the present study, we show that when A2780/100 and A2780 cells were treated with Cbl, GSH was extruded via methionine or cystathionine‐inhibitable transporters of intact plasma membrane. GSH loss was followed by a rapid increase in ROS levels. The resistant, but not drug‐sensitive cells normalized the intracellular GSH concentration along with ROS levels within 4–6 h after Cbl addition, and survived drug treatment. Normalization of GSH and ROS levels in A2780/100 cells correlated well with elevated γ‐glutamylcysteine synthetase (γ‐GCS) activity (10 ± 1.8‐fold over A2780 cells). Ectopic overexpression of the γ‐GCS heavy subunit in drug‐sensitive cells nearly restored GSH and ROS to pre‐treatment levels consequently increased cellular resistance to genotoxic agents (Cbl, Cpl, and IR), while overexpression of γ‐GCS light subunit had no such effects. Thus, in our model system, drug‐resistant cells have the inherent ability to maintain increased γ‐GCS activity, reestablish physiological GSH, and cellular redox state and maintain increased cellular resistance to DNA cross‐linking agents and IR. © 2006 Wiley‐Liss, Inc.
Approximation algorithms for minimizing total weighted completion time of orders on identical machines in parallel
Authors: Leung Joseph Y‐T. , Li Haibing , Pinedo Michael
Published: February 2006

We consider the problem of scheduling orders on identical machines in parallel. Each order consists of one or more individual jobs. A job that belongs to an order can be processed by any one of the machines. Multiple machines can process the jobs of an order concurrently. No setup is required if a machine switches over from one job to another. Each order is released at time zero and has a positive weight. Preemptions are not allowed. The completion time of an order is the time at which all jobs of that order have been completed. The objective is to minimize the total weighted completion time of the orders. The problem is NP‐hard for any fixed number (≥2) of machines. Because of this, we focus our attention on two classes of heuristics, which we refer to as sequential two‐phase heuristics and dynamic two‐phase heuristics. We perform a worst case analysis as well as an empirical analysis of nine heuristics. Our analyses enable us to rank these heuristics according to their effectiveness, taking solution quality as well as running time into account. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Frequency of knowledge of results and motor learning in persons with developmental delay
Authors: Rice Martin S , Hernandez Holly G
Published: February 2006

The purpose of this study was to investigate the effect of high versus low frequency knowledge of results (KR) in a group of 16 individuals with developmental delay and in gender and age‐matched average individuals learning a motor skill on a laptop computer. Participants were randomly assigned to either a 100% KR or a 50% KR group. KR was provided during the acquisition phase according to group assignment as participants learned the motor skill, whereas no KR was provided during the retention phase. Results indicated both populations who received 50% KR in the acquisition phase demonstrated better performance in the retention phase than those who received 100% KR. The results of this study suggest that, as has been found in the average population, feedback that is too frequent can interfere with learning and retention of tasks for individuals with developmental disabilities (DD). Limitations involved the small sample size along with the task potentially being artificial in nature. Future research is needed to study further the effects of frequency of KR on skill acquisition, particularly in instrumental activities of daily living in this population. Copyright © 2006 John Wiley & Sons, Ltd
Die Geschichte der Alkylanzien: “Die klinische Prüfung ist das entscheidende Terrain”
Authors: Meyer Ulrich
Published: February 2006

Deutschland – onkologische “Apotheke der Welt”? In der “Deutschen Medizinischen Wochenschrift” zogen der Präsident der Deutschen Krebsgesellschaft und der Direktor eines US‐amerikanischen Pharmaunternehmens 1999 eine tendenziell ernüchternde Bilanz der “Arzneimittelentwicklung in der Onkologie ... unter besonderer Berücksichtigung des Standorts Deutschland.”
Tumorhemmende Metallverbindungen: Entwicklung, Bedeutung und Perspektiven
Authors: Galanski Mathea Sophia , Keppler Bernhard K.
Published: February 2006

Die weltweit in der Klinik etablierten tumorhemmenden Metallverbindungen Cisplatin, Carboplatin und Oxaliplatin werden erfolgreich vor allem in der Kombinationschemotherapie mit etablierten rein organischen Tumortherapeutika eingesetzt. Die besten Ergebnisse werden mit Cisplatin am Hodentumor mit Heilungsraten um 90 % erzielt. Leider ist das Wirkungsspektrum der vorangenannten Platinkomplexe beschränkt, und es kommt mitunter zu sehr erheblichen Nebenwirkungen. Die Ausweitung des Indikationsspektrums sowie eine Verringerung der systemischen Toxizität scheint mit der Entwicklung neuer Metallkoordinationsverbindungen möglich, die Ruthenium oder Gallium als Zentralion enthalten. Die Ergebnisse aus zwei Phase‐I‐Studien stimmen hoffnungsvoll.
Nutzen von Lipidsenkern im Rahmen der Sekundärprävention
Authors: Weizel Achim
Published: February 2006

Stellungnahme der Deutschen Gesellschaft zur Bekämpfung von Fettstoffwechselstörungen und ihren Folgeerkrankungen DGFF (Lipid‐Liga) e. V.

Mit der Diskussion neuerer Studienergebnisse zum Stellenwert der Statine in der Sekundärprävention ist eine gewisse Verunsicherung der Ärzteschaft und auch der Patienten trotz des erwiesenen Nutzens einer konsequenten LDL‐Cholesterinsenkung im Hinblick auf die Mortalität und Morbidität der koronaren Herzkrankheit eingetreten.
Inhibition von Virulenzfaktoren: Ein neuer Ansatz zur Entwicklung von Antibiotika
Authors: Holzgrabe Ulrike
Published: February 2006

Die Entwicklung neuer Antibiotika hinkt immer mehr hinter der Entwicklung von Resistenzen gegen Antibiotika zurück. Somit wird es zunehmend dringlicher, Antibiotika mit neuen Wirkmechanismen zu entwickeln.
Risk estimates for uniparental disomy following prenatal detection of a nonhomologous Robertsonian translocation
Authors: Shaffer Lisa G.
Published: February 2006

Carriers of nonhomologous Robertsonian translocations (ROB) are at risk for having offspring with uniparental disomy (UPD). Although risk estimates have been calculated in several independent studies, the estimates have not been optimal because most studies are not of sufficient size and UPD events are rare. However, these collective data have provided the opportunity to derive an overall risk estimate for UPD in the fetus after the prenatal identification of a ROB. Copyright © 2006 John Wiley & Sons, Ltd.
The relation between fetal nasal bone length and biparietal diameter in the Korean population
Authors: Shin Joong Sik , Yang Jae Hyug , Chung Jin Hoon , Kim Moon Young , Ryu Hyun Mee , Han Jung Yeol , Choi June Seek
Published: February 2006

Objective

To evaluate the relation between fetal nasal bone length (NBL) and biparietal diameter (BPD) at 15–19.9 (20) weeks of gestation by ultrasonography in the Korean population.

Methods

The study population included 1268 Korean women (aged between 19 and 45 years) with a singleton pregnancy who registered at the Maternal Fetal Medicine Unit of Samsung Cheil Hospital between September 2003 and February 2005. Ultrasound measurements of NBL were performed using a strict sagittal plan of the fetal head. Other fetal biometry profiles were conducted before amniocentesis for fetal karyotyping.

Results

NBL and fetal biometry profiles were measured successfully in 77.9% (988/1268) of the fetuses. NBL was found to increase linearly as a function of BPD (P < 0.001) with a median NBL of 4.4 mm (range 1.9–7.9). NBL increases through 15–19.9 (20) weeks of gestation were given by the equation NBL (mm) = 0.0836 × BPD (mm) + 1.368 (R2 = 0.1, P < 0.001).

Conclusions

Fetal NBL and BPD are linearly related in the second trimester. Fetal NBL in the Korean population is likely to be shorter than that reported for Caucasians and African‐Americans. Copyright © 2006 John Wiley & Sons, Ltd.
Unusual sonographic features of ARPKD
Authors: Okumura Maria , Bunduki Victor , Shiang Christina , Schultz Regina , Zugaib Marcelo
Published: February 2006

The classic sonographic appearance of the kidneys in fetuses with autosomal recessive polycystic kidney disease (ARPKD) has been well described. We report a case of enlarged kidneys with pyramidal hyperechogenicity quite similar to medullary nephrocalcinosis found in a fetus at 34 weeks' gestation. At 39 weeks, a female neonate was delivered and died after 22 h due to pulmonary insufficiency secondary to severe oligohydramnios. On pathological analysis, the gross and microscopic findings were typical of ARPKD with diffuse dilatation of tubules throughout. The fetal renal lobulation was prominent and on section, the pyramids were delineated within each lobule, accounting for the clear image of the pyramids observed on sonography. Copyright © 2006 John Wiley & Sons, Ltd.
Detecting sex chromosome anomalies and common triploidies in products of conception by array‐based comparative genomic hybridization
Authors: Ballif Blake C. , Kashork Catherine D. , Saleki Reza , Rorem Emily , Sundin Kyle , Bejjani Bassem A. , Shaffer Lisa G.
Published: February 2006

Objectives

In recent years, array‐based comparative genomic hybridization (array CGH) has moved to the forefront of molecular cytogenetics with its ability to rapidly characterize chromosome abnormalities at resolutions much higher than routine chromosome banding. However, array CGH, like all CGH procedures, has heretofore been deemed unable to detect ploidy, a major cause of fetal demise and spontaneous miscarriage.

Method

We recently developed a CGH microarray that is designed for detecting aneuploidy and unbalanced chromosome rearrangements. Here, we introduce the use of a Klinefelter male cell line (47,XXY) as a control for array CGH analyses on products of conception (POCs).

Results

This approach facilitates the detection of common trisomies and monosomies of the sex chromosomes by reducing the analysis to the identification of single copy gains or losses. Furthermore, in a blinded study, careful interpretation of the microarray results with particular attention to the sex chromosome ratios between the patient sample and the control allowed for the detection of some common triploidies.

Conclusion

These results suggest that using a chromosomally abnormal cell line in array CGH analysis can be applied to other CGH platforms and that array CGH, when properly performed and analyzed, is a powerful tool that can detect most chromosomal abnormalities observed in a clinical setting including some polyploidies. Copyright © 2006 John Wiley & Sons, Ltd.
Modification of immobilized metal complexes toward the design and synthesis of functional materials for nitric oxide delivery
Authors: Mitchell‐Koch Jeremy T. , Padden Karen M. , Borovik A. S.
Published: February 2006

Functional polymeric materials containing immobilized metal complexes with the potential to bind nitric oxide (NO) are described. The materials were synthesized using template copolymerization techniques and contain immobilized metalloporphyrin and metallosalen (N,N′‐bis(salicylidene)‐1,2‐ethylenediaminato(2‐)) sites where NO binding occurs. A potential drawback of current materials designed for NO‐delivery is the rebinding of NO to the material after release. To minimize this undesirable rebinding event, materials were prepared in which immobilized sites contain additional covalently‐linked functional groups that can bind to the metal centers after NO dissociation. A model system with a covalently attached CoIIsalen complex and pyridine groups confirmed that the immobilized sites bind NO in the presence of the additional ligands. Attempts to immobilize an iron porphyrin, containing two axial imidazole ligands, were unsuccessful because the lability of the iron center prevented the formation of a stable template. Instead, the desired material was achieved by selecting CoIII porphyrin with axially coordinated imidazole ligands as the template complex. Once immobilized, a procedure was developed to remove the cobalt ions and incorporate iron into the sites. The site structure of these new immobilized sites was examined spectroscopically. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2282–2292, 2006
Synthesis and characterization of new aromatic polyamides bearing crown ethers or their dipodal counterparts in the pendant structure. I. Benzo‐12‐crown‐4 and ortho‐bis(2‐ethoxyethoxy)benzene
Authors: Calderón Verónica , García Félix C. , De La Peña José L. , Maya Eva M. , García José M.
Published: February 2006

Two novel isophthalic diacid‐based monomers have been synthesized by inclusion in ring position 5 of a functionalized benzoylamine moiety. The functionalization includes a 12‐crown‐4 ether group fused with the benzene subunit and a dipodand substructure, formally a disubstitution of the benzene ring, with two sequences of ethyl‐terminated ethylene oxide units, which represent the open‐chain counterpart of the alicylic crown moiety. The polycondensation of the two diacids with five aromatic diamines yielded 10 new polyamides with crown or podand pendant substructures. The polyamides had previously been chemically characterized by NMR, IR, and elemental analysis. The polymers showed high glass transition temperatures of up to 349 °C, good thermal stability (Tdonset, N2 ≈ 400 °C), and improved solubility in organic solvents. The presence of acyclic or alicyclic oxyethylene sequences as crown ether or podand substructures and an additional amide side group per repeat unit made the polymers essentially amorphous and improved their water absorption ability in comparison with nonsubstituted polyamides. Water uptake values as high as 12% were observed at 65% relative humidity. All the polyamides showed a good film‐forming ability, and the mechanical properties of these films are considered to be satisfactory for experimental aromatic polyamides. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2270–2281, 2006
The influence of surfactant coverage of the minidroplets on RAFT miniemulsion polymerization
Authors: Yang Lei , Luo Yingwu , Li Bogeng
Published: February 2006

The surfactant coverage of minidroplets was tuned by postaddition of more surfactants after preparation of the miniemulsion of styrene. The influence of surfactant coverage on reversible addition‐fragmentation chain transfer (RAFT) miniemulsion polymerization of styrene was investigated. When the surfactant (sodium dodecyl sulfate; SDS) coverage was as low as 40%, two kinds of particles, denoted as polymer and oligomer particles, were formed in the early stage of the polymerization. Polymer chains within two kinds of particles grew in a parallel way during the rest period of the polymerization. The oligomer particles contributed less than 10% to the final monomer conversion but consumed over one in third the original RAFT agent molecules. Oligomer particles were larger in size but much lower in molecular weight. Both the particle size and molecular weight distributions were bimodal. With increase of SDS coverage, the formation of oligomer particles was suppressed. As a result, the nucleation efficiency of the minidroplets was greatly enhanced and the molecular weight and particle size distributions were dramatically narrowed. The formation of the oligomer particles was ascribed to the superswelling occurring in the beginning stage of the polymerization. The experimental observations are in excellent accord to the superswelling theory. Postaddition of surfactant presents a novel method to narrow particle size and molecular weight distributions in RAFT miniemulsion polymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2293–2306, 2006
Novel polyamidoamine‐based hydrogel with an innovative molecular architecture as a Co2+‐, Ni2+‐, and Cu2+‐sorbing material: Cyclovoltammetry and extended X‐ray absorption fine structure studies
Authors: Ferruti Paolo , Ranucci Elisabetta , Bianchi Sabrina , Falciola Luigi , Mussini Patrizia R. , Rossi Manuela
Published: February 2006

An amphoteric polyamidoamine (PAA)‐based hydrogel, named INT‐PAA1, with a novel molecular architecture was prepared and studied as a Co2+‐, Ni2+‐, and Cu2+‐sorbing material. This hydrogel was obtained by the synthesis of a PAA in the presence of a second presynthesized PAA carrying many primary amino groups as side substituents, which acted as a macromolecular crosslinking agent. Therefore, it had an intersegmented structure. INT‐PAA1 exhibited a remarkable sorption capacity and sorption rate for Co2+, Ni2+, and Cu2+ that were advantageously in situ monitored by cyclic voltammetry. An extended X‐ray absorption fine structure spectroscopy characterization of the Co2+/INT‐PAA1 complex was also performed. The very fast and quantitative metal‐ion uptake, made apparent by an intense coloring of the hydrogel, showed remarkable potential for environmental applications such as heavy‐metal detection, recovery, and elimination. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2316–2327, 2006
Terpyridine‐substituted, fluorescent polymers and their chelation with zinc ion: The ligand‐to‐metal ratio and optical properties
Authors: Chu Qinghui , Pang Yi
Published: February 2006

Soluble, fluorescent, terpyridine‐substituted, conjugated polymers were prepared and characterized. The polymer chains included a defined oligo(phenylenevinylene) fragment, on which the terpyridine‐functional group was attached. The polymers were blue‐fluorescent with emission peaks at 400–427 nm in tetrahydrofuran solutions. Upon chelation with the Zn(II) cation, the emission maxima were shifted to a longer wavelength by as much as 113 to 506–526 nm. A model compound was also prepared to aid the structural characterization. The ratio of terpyridine to Zn2+ in the polymer complex was found to be 1:1 on the basis of spectroscopic evidence, which included mass spectrometry, 1H NMR, and Job titration. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2338–2345, 2006
Optical‐limiting and nonlinear optical polyacetylenes: Synthesis of azobenzene‐containing poly(1‐alkyne)s with different spacer and tail lengths
Authors: Yin Shouchun , Xu Hongyao , Su Xinyan , Li Gang , Song Yinlin , Lam Jackywingyip , Tang Benzhong
Published: February 2006

Poly(1‐alkyne)s containing azobenzene pendant groups with different lengths of the spacer and terminal alkyloxy group {[HCC(CH2)mOCOC6H4NNC6H4OCpH2p+1]n, where m = 1, 2, 3, or 9 and p = 4, 7, or 12} were synthesized in satisfactory yields with the [Rh(nbd)Cl]2–Et3N catalyst. All the polymers were soluble in common organic solvents such as CHCl3 and tetrahydrofuran. Their structures and properties were characterized and evaluated with IR, NMR, thermogravimetric analysis, UV, and optical‐limiting and nonlinear optical analyses. All the polymers were thermally stable and decomposed at temperatures as high as ∼300 °C. The optical‐limiting and nonlinear optical properties of the polymers were sensitive to their molecular structures. Polymers having shorter spacer lengths and longer terminal groups showed better performances and larger third‐order nonlinear optical susceptibility (up to 1.34 × 10−10 esu). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2346–2357, 2006