bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular dynamics simulation of antimicrobial peptide arenicin‐2: β‐Hairpin stabilization by noncovalent interactions
Authors: Stavrakoudis Athanassios , Tsoulos Ioannis G. , Shenkarev Zakhar O. , Ovchinnikova Tatiana V.
Published: February 2009

Arenicin‐2 is a 21 residue antimicrobial cyclic peptide, possessing one disulphide bond between residues Cys3 and Cys20. NMR and CD studies suggested that the structure of arenicin‐2 in water represented a well formed, but highly twisted β‐harpin. To investigate the spatial arrangement of the peptide side chains and to get a clear view of its possible amphipathic properties we performed molecular dynamics in explicit water. Four independent trajectories, 50 ns in length, were produced, starting from various initial conformations or by applying different simulation conditions. Arenicin‐2 retained its β‐hairpin structure during simulations, although the residues close to strand ends were found to escape from the ideal hairpin conformation. The type I′ β‐turn connecting the two strands fluctuated between type IV and II′ β‐turn. Conversely, the right‐handed twist of the β‐hairpin was well conserved with average twist value 203° ± 19° per eight residues. Several nonbonded interactions, like hydrophobic interactions between aliphatic side chains, cation/π‐aromatic interactions, CH…π aromatic bond and water bridges, contributed to the hairpin stabilization. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 143–155, 2009.

This 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
Puckering transitions of pseudoproline residues
Authors: Kang Young Kee , Park Hae Sook , Byun Byung Jin
Published: February 2009

The puckering transitions of pesudoprolines such as oxazolidine and thiazolidine residues (Oxa and Thz dipeptides) with trans and cis prolyl peptide bonds were explored by optimizations along the endocyclic torsion angle χ1 using quantum‐chemical methods in the gas phase and in water. The overall shapes of the potential energy surfaces for Oxa and Thz dipeptides in the gas phase and in water are similar to those for the Pro dipeptide, although there are some differences in relative stabilities of local minima and in barriers to puckering transition. On the whole, the barriers to puckering transition for Oxa and Thz dipeptides are computed to be 0.8–3.2 kcal/mol at the B3LYP/6‐311++G(d,p) level in the gas phase and in water, which are lower by 0.5–1.9 kcal/mol than those for the Pro dipeptide. The n → σ* interactions for the delocalization of the lone pair of the prolyl amide nitrogen into the antibonding orbitals that are anti to the lone pair appear to play a role in stabilizing the nonplanar puckered transition states over the corresponding planar structures. The calculated barriers indicate that the down‐to‐up puckering transition can proceed in the orders Pro < Oxa < Thz in the gas phase and Pro ≈ Oxa < Thz in water. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 444–455, 2009.

This 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
Rationally designed dehydroalanine (ΔAla)‐containing peptides inhibit amyloid‐β (Aβ) peptide aggregation
Authors: Rangachari Vijayaraghavan , Davey Zachary S. , Healy Brent , Moore Brenda D. , Sonoda Leilani K. , Cusack Bernadette , Maharvi Ghulam M. , Fauq Abdul H. , Rosenberry Terrone L.
Published: February 2009

Among the pathological hallmarks of Alzheimer's disease (AD) is the deposition of amyloid‐β (Aβ) peptides, primarily Aβ (1–40) and Aβ (1–42), in the brain as senile plaques. A large body of evidence suggests that cognitive decline and dementia in AD patients arise from the formation of various aggregated forms of Aβ, including oligomers, protofibrils and fibrils. Hence, there is increasing interest in designing molecular agents that can impede the aggregation process and that can lead to the development of therapeutically viable compounds. Here, we demonstrate the ability of the specifically designed α,β‐dehydroalanine (ΔAla)‐containing peptides P1 (K‐L‐V‐F‐ΔA‐I‐ΔA) and P2 (K‐F‐ΔA‐ΔA‐ΔA‐F) to inhibit Aβ (1–42) aggregation. The mechanism of interaction of the two peptides with Aβ (1–42) seemed to be different and distinct. Overall, the data reveal a novel application of ΔAla‐containing peptides as tools to disrupt Aβ aggregation that may lead to the development of anti‐amyloid therapies not only for AD but also for many other protein misfolding diseases. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 456–465, 2009.

This 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
The1H,13C,15N resonance assignment, solution structure, and residue level stability of eosinophil cationic protein/RNase 3 determined by NMR spectroscopy
Authors: Laurents Douglas V. , Bruix Marta , Jiménez M. Angeles , Santoro Jorge , Boix Ester , Moussaoui Mohammed , Nogués Maria Victoria , Rico Manuel
Published: February 2009

Eosinophil cationic protein (ECP)/human RNase 3, a member of the RNase A family, is a remarkably cytotoxic protein implicated in asthma and allergies. These activities are probably due to ECP's ability to interact with and disrupt membranes and depend on two Trp, 19 Arg, and possibly an extremely high conformational stability. Here, we have used NMR spectroscopy to assign essentially all1H,15N, and backbone13C resonances, to solve the 3D structure in aqueous solution and to quantify its residue‐level stability. The NMR solution structure was determined on the basis of 2316 distance constraints and is well‐defined (backbone RMSD = 0.81 Å). The N‐terminus and the loop composed of residues 114–123 are relatively well‐ordered; in contrast, conformational diversity is observed for the loop segments 17–22, 65–68, and 92–95 and most exposed sidechains. The side chain NH groups of the two Trp and 19 Arg showed no significant protection against hydrogen/deuterium exchange. The most protected NH groups belong to the first and last two β‐strands, and curiously, the first α‐helix. Analysis of their exchange rates reveals a strikingly high global stability of 11.8 kcal/mol. This value and other stability measurements are used to better quantify ECP's unfolding thermodynamics. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 1018–1028, 2009.

This 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 of quadruplex‐forming tetra‐end‐linked oligonucleotides: Effects of the linker size on quadruplex topology and stability
Authors: Oliviero Giorgia , Borbone Nicola , Amato Jussara , D'Errico Stefano , Galeone Aldo , Piccialli Gennaro , Varra Michela , Mayol Luciano
Published: February 2009

G‐quadruplexes are characteristic structural arrangements of guanine‐rich DNA sequences that abound in regions with relevant biological significance. These structures are highly polymorphic differing in the number and polarity of the strands, loop composition, and conformation. Furthermore, the cation species present in solution strongly influence the topology of the G‐quadruplexes. Recently, we reported the synthesis and structural studies of new G‐quadruplex forming oligodeoxynucleotides (ODNs) in which the 3′‐ and/or the 5′‐ends of four ODN strands are linked together by a non‐nucleotidic tetra‐end‐linker (TEL). These TEL‐ODN analogs having the sequence TGGGGT are able to form parallel G‐quadruplexes characterized by a remarkable high thermal stability. We report here an investigation about the influence of the reduction of the TEL size on the molecularity, topology, and stability of the resulting TEL‐G‐quadruplexes using a combination of circular dichroism (CD), CD melting, 1H NMR spectroscopy, gel electrophoresis, and molecular modeling data. We found that all TEL‐(TGGGGT)4 analogs, regardless the TEL size and the structural orientation of the ODN branches, formed parallel TEL‐G‐quadruplexes. The molecular modeling studies appear to be consistent with the experimental CD and NMR data revealing that the G‐quadruplexes formed by TEL‐ODNs having the longer TEL (L1‐4) are more stable than the corresponding G‐quadruplexes having the shorter TEL (S1‐4). The relative stability of S1‐4 was also reported. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 466–477, 2009.

This 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
Real time automatic skeleton and motion estimation for character animation
Authors: Xiao Zhidong , Nait‐Charif Hammadi , Zhang Jian J.
Published: February 2009

Motion capture is prevalent in the pipeline of realistic articulated character animation. To define accurate joint positions and joint orientations for the movement of a hierarchical human‐like character without using a pre‐defined skeleton remains a challenge for motion capture studios. In this paper, we present a method for automatically estimating and determining the topology of a hierarchical human skeleton from optical motion capture data based on the human biomechanical information. Through the use of a novel per‐frame based recursive method with joint angle minimization, human skeleton mapping from optical markers and joint angle estimation are achieved in real time. Copyright © 2009 John Wiley & Sons, Ltd.
Cooperative Effects on Radical Recombination in CYP3A4‐Catalyzed Oxidation of the Radical Clock β‐Thujone
Authors: Jiang Yongying , Ortiz de Montellano Paul R.
Published: February 2009

Tick tock: The timing of the β‐thujone radical clock (see scheme) can be specifically altered by an allosteric effector. Progesterone, a well‐documented CYP3A4 allosteric effector, was found to increase the yield of the unrearranged, C4‐derived product of β‐thujone oxidation at the expense of the combined yields of all the rearranged C4‐oxidized metabolites. The results demonstrate that the apparent radical recombination rate in the CYP3A4 hydroxylation of β‐thujone is accelerated by the progesterone hetereotropic cooperativity.

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Clinical impact of sirolimus‐eluting stent in ST‐segment elevation myocardial infarction: A meta‐analysis of randomized clinical trials
Authors: Piscione Federico , Piccolo Raffaele , Cassese Salvatore , Galasso Gennaro , Chiariello Massimo
Published: February 2009

Objectives: To evaluate outcome of patients undergoing sirolimus‐eluting stent (SES) as compared to bare‐metal stent (BMS) implantation during primary angioplasty for ST‐segment elevation myocardial infarction (STEMI). Background: The role of SES in primary percutaneous coronary intervention setting is still debated. Methods: We searched Medline, EMBASE, CENTRAL, scientific session abstracts, and relevant Websites for studies in any language, from the inception of each database until October 2008. Only randomized clinical trials with a mean follow‐up period >6 months and sample size >100 patients were included. Primary endpoint for efficacy was target‐vessel revascularization (TVR) and primary endpoint for safety was stent thrombosis. Secondary endpoints were cardiac death and recurrent myocardial infarction (MI). Results: Six trials were included in the meta‐analysis, including 2,381 patients (1,192 randomized to SES and 1,189 to BMS). Up to 12‐month follow‐up, TVR was significantly lower in patients treated with SES as compared to patients treated with BMS (4.53% vs. 12.53%, respectively; odds ratio [OR] 0.33; 95% confidence interval [CI] 0.24–0.46; P < 0.00001). There were no significant differences in the incidence of stent thrombosis (3.02% vs. 3.70%, OR = 0.81 [95% CI, 0.52–1.27], P = 0.81), cardiac death (2.77% vs. 3.28%, OR = 0.84 [95% CI, 0.52–1.35], P = 0.47), and recurrent MI (2.94% vs. 4.04%, OR = 0.71 [95% CI, 0.45–1.11], P = 0.13) between the two groups. Conclusion: SES significantly reduces TVR rates as compared to BMS in STEMI patients up to 1 year follow‐up. Further studies with larger population and longer follow‐up time are needed to confirm our findings. © 2009 Wiley‐Liss, Inc.
Novel uses of the proxis embolic protection catheter
Authors: Brilakis Emmanouil S. , Banerjee Subhash
Published: February 2009

The Proxis catheter has been designed for proximal embolic protection during saphenous vein graft interventions. The Proxis catheter's flexible and kink‐resistant design, lubricity, and atraumatic tip allow deep seating in target vessels. We describe six challenging percutaneous coronary intervention cases, in which the Proxis catheter was used in arterial grafts, sequential saphenous vein grafts, and native coronary arteries. Deep seating of the Proxis catheter enabled vessel visualization and equipment delivery, allowing successful completion of each case. © 2009 Wiley‐Liss, Inc.
Long‐term clinical and angiographic outcomes after implantation of sirolimus‐eluting stents with a “modified mini‐crush” technique in coronary bifurcation lesions
Authors: Yang Hyoung‐Mo , Tahk Seung‐Jea , Woo Seong‐Ill , Lim Hong‐Seok , Choi Byoung‐Joo , Choi So‐Yeon , Yoon Myeong‐Ho , Park Jin‐Sun , Zheng Mingri , Hwang Gyo‐Seung , Kang Soo‐Jin , Shin Joon‐Han
Published: February 2009

Objectives:

We aimed to evaluate long‐term outcomes of a modified mini‐crush technique for treating bifurcation lesions.

Background:

Coronary bifurcation lesions continue to show a relatively high restenosis rate despite the use of a drug‐eluting stent (DES).

Methods:

We enrolled 52 consecutive patients treated with sirolimus‐eluting stent implantation using the modified mini‐crush technique for 56 coronary bifurcation lesions (MEDINA 1, 1, 1, 89.2%; left main lesion, 28.6%). To minimize crushing, the proximal marker of the side branch (SB) stent was located in contact with the main vessel (MV) stent. After SB stenting, we drew the SB balloon proximally and dilate the SB ostium at a rated burst pressure. After MV stenting, both vessels were redilated at a high pressure before final kissing balloon (FKB) inflation. Clinical and angiographic follow‐ups were performed at 9 months.

Results:

Immediate procedural success was obtained in all cases including a FKB success rate of 98%. At 9 months, there was no death or myocardial infarction. The incidences of major adverse cardiac events and target lesion revascularization were 11.8 and 7.8%, respectively. The in‐stent restenosis (ISR) rate was 14.9% (SB ostium, 10.6%) and most ISRs were of the focal type and the cause of ISR was intimal hyperplasia but not chronic stent recoil by an intravascular ultrasound study. There was one case (2.0%) of late stent thrombosis without any ischemic symptoms during the follow‐up period of 9 months.

Conclusions:

Modified mini‐crush technique provides excellent technical and angiographic success immediately and it also provides acceptable long‐term outcomes. © 2009 Wiley‐Liss, Inc.
Antiplatelet therapy in percutaneous coronary intervention: A critical review of the 2007 AHA/ACC/SCAI guidelines and beyond
Authors: Cohen Marc
Published: February 2009

Antiplatelet therapy is a mainstay in the treatment of patients who have undergone percutaneous coronary intervention (PCI). Although the 2007 PCI treatment guidelines were published by the American College of Cardiology, the American Heart Association, and the Society for Cardiovascular Angiography and Interventions, new clinical evidence has emerged, expanding our understanding of antiplatelet use and potentially affecting the treatment guidelines. For example, clinical trial results prompted a Science Advisory to recommend that dual therapy with aspirin and clopidogrel be used for longer periods—up to 1 year in patients who receive bare metal stents and at least 1 year in patients receiving drug‐eluting stents. New trial results have also emerged regarding the use of glycoprotein IIb/IIIa antagonists such as abciximab, eptifibatide, and tirofiban. This article reviews the current recommendations for antiplatelet therapy in PCI patients, recent trial results, newly developed agents, ongoing clinical trials, and the future direction of antiplatelet therapy in patients who undergo PCI. © 2009 Wiley‐Liss, Inc.
Development of animal model for calcified chronic total occlusion
Authors: Suzuki Yoriyasu , Oyane Ayako , Ikeno Fumiaki , Lyons Jennifer K. , Yeung Alan C.
Published: February 2009

Chronic total coronary occlusion (CTO) remains a major problem for percutaneous revascularization, with relatively low primary success rates and a high incidence of restenosis and reocclusion compared with those of subtotal stenoses. No reproducible animal model simulating human CTOs has previously been developed. We hypothesized that an apatite‐coated bioabsorbable polymer sponge could be implanted to produce calcified CTO lesions in animal coronary arteries/peripheral arteries. A total of 10 swine and six rabbits were used for this study. The apatite‐coated bioabsorbable polymer sponges were implanted into a preselected segment of coronary and peripheral arteries. Four weeks after implantation, both angiography and histopathology were performed to document the presence or absence of CTO lesions. We could reproducibly develop CTO lesions in animal coronary/peripheral arteries that mimic human CTO lesions. These lesions were found to have microvascular channels and microcalcification similar to those of human older CTO lesions and demonstrate the development of adventitial arterioles, a consistent finding in human CTO. This CTO model might provide a platform for evaluating future CTO technologies as well as contributing to a better understanding of CTOs in both educational and practical terms. © 2009 Wiley‐Liss, Inc.
Application of recurrent relationships in chromatography
Authors: Zenkevich Igor G.
Published: February 2009

Recurrent relationships of general form A(x + k) = aA(x) + b were shown to be applicable to the approximation not only of values of most physicochemical constants of organic compounds (A) indicating monotonous or oscillating variations within different homologous series (x = nC, k = 1 or 2), but also of the dependences of chromatographic retention parameters on the number of carbon atoms in homologue molecules (A = tR, x = nC) in gas and high performance liquid chromatography (HPLC). In these cases the values of argument (the number of carbon atoms in the molecule) are integer by definition, while the functions are discrete. Besides that, the same recurrent equations describe the temperature dependence of retention times of analytes under isothermal separation conditions in gas chromatography (A = tR, x = T, k = ΔT = const) and the dependences of retention times on the concentrations of an organic solvent as an eluent component (A = tR, x = C, k = ΔC = const) under isocratic separation conditions in HPLC, which are the examples of the functions of continuous arguments. Key mathematical properties of recurrences explaining us their promising applications in chemistry and chromatography are discussed. The method to apply recurrent equations to arbitrary, not necessary equidistant, values of continuous arguments is considered. Copyright © 2009 John Wiley & Sons, Ltd.
Dual Amino‐Functionalised Phosphonium Ionic Liquids for CO2 Capture
Authors: Zhang Yanqiang , Zhang Suojiang , Lu Xingmei , Zhou Qing , Fan Wei , Zhang XiangPing
Published: February 2009

CO2 is locked up: Dual amino‐functionalised phosphonium ionic liquids (ILs; see figure) have been prepared. The ILs have excellent thermal properties, such as low glass transition temperatures and high thermal decomposition temperatures. The supported CO2 absorption of four of the ILs on porous SiO2 was found to approach one mol CO2 per mol IL, a factor of two greater than that reported before.

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A series of 20 dual amino‐functionalised phosphonium ionic liquids, (3‐aminopropyl)tributylphosphonium amino acid salts ([aP4443][AA], in which [AA]−=[Ala]−, [Arg]−, [Asn]−, [Asp]−, [Cys]−, [Gln]−, [Glu]−, [Gly]−, [His]−, [Ile]−, [Leu]−, [Lys]−, [Met]−, [Phe]−, [Pro]−, [Ser]−, [Thr]−, [Trp]−, [Tyr]− and [Val]−), has been prepared. Their physicochemical properties, such as density, viscosity, glass transition and thermal decomposition temperatures and conductivity, have been determined. In particular, the [aP4443][AA] ionic liquids (ILs) have low glass transition temperatures ranging from −69.7 to −29.6 °C and high decomposition temperatures (all above 200 °C). The effects of the variation of the structure of [AA]− on the above physicochemical properties are discussed. Furthermore, the CO2 absorption of [aP4443][Gly], [aP4443][Ala], [aP4443][Val] and [aP4443][Leu], taken as examples, was investigated. It was found that the supported absorption of CO2 by the [aP4443][AA] ILs almost reaches equilibrium within 80 min, the chemical absorption of CO2 by the [aP4443][AA] ILs approaches 1 mol CO2 per mol ionic liquid (twice that reported before) and the [aP4443][AA] ILs can be repeatedly recycled for CO2 uptake.
Synthesis and Conformational Analysis of (α‐D‐Galactosyl)phenylmethane and α‐,β‐Difluoromethane Analogues: Interactions with the Plant Lectin Viscumin
Authors: Kolympadi Maria , Fontanella Marco , Venturi Chiara , André Sabine , Gabius Hans‐Joachim , Jiménez‐Barbero Jesús , Vogel Pierre
Published: February 2009

To bend about: The conformations of three phenyl‐C‐galactosides in solution were evaluated by using theoretical calculations and NMR spectroscopic studies. The α‐CF2 derivative (see scheme) showed significant flexibility of the pyranose ring and around the pseudoanomeric center, whereas the other two analogues more closely resemble the natural galactosides. Regardless, all three compounds bind to a plant lectin.

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(α‐D‐Galactosyl)phenylmethane (1), (α‐ and β‐D‐galactosyl)(difluoro)phenylmethane (2 and 3) have been prepared and their conformations in solution were described by using a combination of force‐field calculations and NMR spectroscopic studies. Galactoside 1 adopts a 4C1 chair conformation and an exo anomeric orientation, as is the case for natural α‐galactosides. The X‐ray crystal structure of its difluoromethylene derivative 2 similarly shows a 4C1 chair conformation. Surprisingly, compound 2 exhibits a different equilibrium between 1C4 chair and 1S3 skew boat conformations and significant flexibility around the pseudoglycosidic linkage when in solution. The β‐stereoisomer 3 adopts a major 4C1 chair conformation. Interestingly, C‐galactosides 1, 2, and 3 bind to viscumin (VAA), a galactoside‐specific lectin, which is confirmed by NMR experiments and docking calculations.
Mechanistic Insight into Formation of Oxo‐Iron(IV) Porphyrin π‐Cation Radicals from Enzyme Mimics of Cytochrome P450 in Organic Solvents
Authors: Hessenauer‐Ilicheva Natalya , Franke Alicja , Meyer Dominik , Woggon Wolf‐D. , van Eldik Rudi
Published: February 2009

Two new models for cytochrome P450 in which the thiolate axial ligand is replaced by an RSO3− group, form oxo‐iron(IV) porphyrin π‐cation radicals as sole oxidation products in “peroxo shunt” reactions (see scheme) independent of the nature of the employed solvent (polar or non‐polar) and electronic nature of the porphyrin rings.

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Two new models for cytochrome P450 in which the thiolate axial ligand is replaced by a RSO3− group, form oxo‐iron(IV) porphyrin π‐cation radicals as sole oxidation products in “peroxo shunt” reactions independent of the nature of the employed solvent (polar or non‐polar) and electronic nature of the porphyrin rings. Although the properties of the solvent and push–pull effects from the porphyrin rings do not affect the mode of the OO bond cleavage (heterolytic or homolytic) in these models, they strongly affect the rate and mechanism of each reaction step leading to the formation of the high‐valent iron intermediates. This article reports the results of mechanistic studies involving the measurements of the rate of oxo‐iron(IV) porphyrin π‐cation radical formation from the enzyme mimics of P450 for different oxidant concentration, temperature and pressure in selected organic solvents. Extraction of the appropriate rate constants and activation parameters for the reactions studied enable a detailed discussion of the effects of solvent and electronic nature of the porphyrin rings on the position of the first pre‐equilibrium involving formation of the acylperoxo‐iron(III) porphyrin intermediate, as well as on the rate of heterolytic OO bond cleavage leading to the formation of the high‐valent iron species. Furthermore, an unusual effect of solvent on the kinetics of oxo‐iron(IV) porphyrin π‐cation radical formation in methanol is demonstrated and discussed in the present work.
Anionic Reagents with Silicon‐Containing Double Bonds
Authors: Scheschkewitz David
Published: February 2009

ESi transfer: Anionic compounds capable of transferring a silicon‐containing double bond are reviewed (see figure), particularly reagents with SiSi moieties (Tip=2,4,6‐iPr3C6H2, M=Li, Na, K) and their applications towards main‐group and transition‐metal electrophiles, as well as their reactivity towards organic compounds. A few recently reported derivatives with SiC (Ad=1‐adamantyl) and SiP moieties are included for completeness.

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Anionic compounds capable of transferring a silicon double bond are summarized following an introduction to the differences between alkenes and their heavier homologues. The main focus is on reagents with SiSi moieties and their applications towards main‐group and transition‐metal electrophiles, as well as their reactivity towards organic compounds, but a few recently reported derivatives with SiC and SiP bonds are also included.
Toward Volatile and Nonvolatile Molecular Memories: Fluorescence Switching Based on Fluoride‐Triggered Interconversion of Simple Porphyrin Derivatives
Authors: Shundo Atsuomi , Hill Jonathan P. , Ariga Katsuhiko
Published: February 2009

Written in the gel: A fluoride‐writable memory system has been demonstrated by using two porphyrin derivatives. Structural modification enabled both volatile and nonvolatile modes. For both porphyrins, fluorescence is quenched by addition of F−with only one of the derivatives returning to its initial fluorescent state following removal of F−(see scheme). Nonvolatile behaviour is based on anion‐induced conversion from porphyrin to oxoporphyrinogen.

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An Extremely Simple Dibenzopentalene Synthesis from 2‐Bromo‐1‐ethynylbenzenes Using Nickel(0) Complexes: Construction of Its Derivatives with Various Functionalities
Authors: Kawase Takeshi , Konishi Akihito , Hirao Yasukazu , Matsumoto Kouzou , Kurata Hiroyuki , Kubo Takashi
Published: February 2009

Nice and easy: A very simple synthesis for dibenzopentalenes, which starts from 1‐bromo‐2‐ethynylbenzenes, has been developed. It uses Ni0 complexes (see scheme), from which a relatively stable NiII complex as an important intermediate has been isolated. Dibenzopentalenes with various functional groups can be prepared by the procedure, and their electronic properties are consistent with theoretical calculations.

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An extremely simple dibenzopentalene synthesis from readily available 2‐bromo‐1‐ethynylbenzenes using a nickel(0) complex is described. Although the yields are moderate, the formation of three CC bonds in a single process and the high availability of the starting materials are important advantages of this reaction. The corresponding aryl–nickel(II) complex as an important intermediate was isolated as relatively stable crystals, and the structure was confirmed by X‐ray crystallographic analysis. The high stability of this complex should play a key role in this reaction. The reaction is applicable to the preparation of dibenzopentalenes bearing various functional groups. Their electronic properties are consistent with theoretical calculations. The cyclic voltammograms of these compounds reveal highly amphoteric redox properties. In particular, the electron‐donating property of a tetramethoxy derivative is greater than that of oligothiophenes and dibenzodithiophenes and almost comparable to that of pentacene.
Synthesis of Carbosilane Dendrimers Containing up to Four Metal Layers
Authors: Angurell Inma , Rossell Oriol , Seco Miquel
Published: February 2009

Onion structures: Carbosilane dendrimers containing up to four metal layers have been constructed (see picture). The metal layers are linked by di‐ or tritopic N,P ligands. Selective deconstruction of the dendrimers is achieved by using salts of chloride or iodide anions.

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Metallodendrimers are an important class of materials with valuable properties and applications in a large number of areas. Herein, we report a highly efficient route for the synthesis of carbosilane dendrimers containing multimetal layers. The procedure involves the use of heteroditopic and tritopic P,N ligands as connectors of the metal layers. The synthetic strategy is based on the ability of the latter ligands to react selectively with the metal complexes [AuCl(tht)] (tht: tetrahydrothiophene), [{RuCl2(p‐cymene)}2] and [Pd(η3‐2‐MeC3H4)(cod)](OTf) (cod: 1,5‐cyclooctadiene; OTf: triflate). In this way, metallodendrimers containing trimetallic Ru‐Au‐Pd or tetrametallic Ru‐Au‐Au′‐Pd layers have been formed and characterized. The trimetallic dendrimer 9 can be selectively deconstructed by cleavage of the RuN or AuN bonds by reaction with chloride or iodide salts, respectively.
Highly Sensitive Magnetic Effects Induced by Hydrogen‐Bonding Interactions in a High‐Spin Metallosupramolecular Fe4II [2×2] Grid‐Type Complex
Authors: Stefankiewicz Artur R. , Lehn Jean‐Marie
Published: February 2009

A sensitive magnetic nanoprobe: Hydrogen‐bonding interactions are reflected with great sensitivity in the 1H NMR spectra of a high‐spin multinuclear Fe4II [2×2] grid‐type complex (see scheme) and the measured shifts can be used to evaluate the hydrogen‐bond donating ability. The grid complex also represents a prototype of a very sensitive magnetic nanoreceptor for the detection of very small changes around a magnetic center.

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Chemo‐ and Regioselective Palladium‐Catalyzed Oxycyclization Reactions of Allendiols: Preparation of Five‐, Six‐, and Eight‐Membered Cycles
Authors: Alcaide Benito , Almendros Pedro , Carrascosa Rocío , Martínez del Campo Teresa
Published: February 2009

Positive discrimination: Chemo‐ and regioselective palladium‐catalyzed cycloetherification of allendiols, namely β,γ‐ and γ,δ‐allendiols, may occur by judicious choice of palladium‐catalyzed conditions owing to their potential ability to discriminate between both nucleophilic sites (see scheme).

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Cover Picture: Gated and Differently Functionalized (New) Porous Capsules Direct Encapsulates' Structures: Higher and Lower Density Water (Chem. Eur. J. 8/2009)
Authors: Mitra Tamoghna , Miró Pere , Tomsa Adrian‐Raul , Merca Alice , Bögge Hartmut , Ávalos Josep Bonet , Poblet Josep Maria , Bo Carles , Müller Achim
Published: February 2009

Ubiquitous water is apart from its anomalies, for several reasons the most mysterious compound. According to its basic role in life processes it has even been considered as a biomolecule especially in context of the important role of confined “high and low density water”. C. Bo, A. Müller et al. report on page 1844 ff., confined higher and lower density water assemblies encapsulated in the same type of porous capsule that exhibit differently functionalized internal shells (see picture).

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Post‐myocardial Infarction Intraventricular Conduction Defects and B‐type Natriuretic Peptide Levels
Authors: Ciuraszkiewicz Katarzyna , Janion Marianna , Sielski Janusz , Dudek Dariusz , Gawor Zenon
Published: February 2009

Background

Levels of B‐type natriuretic peptide (BNP), a significant marker of left ventricular (LV) dysfunction, may provide information on the severity of heart failure in patients with intraventricular conduction defects (IVCD).The aim of this study was to measure serum BNP levels in post‐myocardial infarction (MI) patients with IVCD.

Methods

In 2004–2005 during standard follow‐up at 6 mo after acute MI in 158 subjects, BNP was measured using an immunoenzymatic method. Of them, 126 patients had IVCD: 31, left bundle branch block (LBBB); 36, right bundle branch block (RBBB); 30, left anterior hemiblock (LAH); and 29, left posterior hemiblock (LPH). Thirty two patients with a previous MI, but without IVCD, served as controls, whereas 15 healthy subjects entered the comparative group.

Results

In post‐MI patients with IVCD, the mean BNP level was significantly higher than in their counterparts without IVCD (p < 0.001) and in healthy subjects (p < 0.001). The highest BNP level was found in patients with LBBB and RBBB. In patients with LAH and LPH, levels of BNP were insignificantly higher than in patients without IVCD.

Conclusions

Significantly higher BNP levels in patients with previous MI and IVCD suggest more severe heart failure than in their counterparts without IVCD with comparable LV ejection fraction. Copyright © 2008 Wiley Periodicals, Inc.
Glycopeptide Dendrimers with High Affinity for the Fucose‐Binding Lectin LecB from Pseudomonas aeruginosa
Authors: Kolomiets Elena , Swiderska Magdalena A. , Kadam Rameshwar U. , Johansson Emma M. V. , Jaeger Karl‐Erich , Darbre Tamis , Reymond Jean‐Louis
Published: February 2009

Dendritic antibacterial agents: Glycopeptide dendrimer biofilm inhibitors were synthesized combinatorially and optimized for binding to the fucose‐specific lectin LecB, which has high affinity of fucose. These dendritic ligands are potential antibacterial agents against Pseudomonas aeruginosa, an antibiotic resistant human pathogen.

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The fucose‐specific lectin LecB is implicated in tissue binding and biofilm formation by the opportunistic pathogen Pseudomonas aeruginosa, which causes severe respiratory tract infections mainly in immunocompromised patients or cancer patients undergoing chemotherapy. With a view to developing multivalent LecB inhibitors as novel antibacterial agents, a combinatorial library containing 15 625 tetravalent C‐fucosyl peptide dendrimers with the basic structure (CFuc‐X6X5X4)4(LysX3X2X1)2LysIleHisNH2 (CFuc=α‐L‐fucosyl acetic acid, X1–6=amino acids, Lys=lysine branching) was screened for lectin binding using on‐bead binding assays. Ten tetravalent and three octavalent dendrimers derived from the identified sequences were prepared by solid‐phase peptide synthesis (SPPS), cleaved from the resin, and purified by preparative HPLC. Relative affinities of these soluble ligands to LecB were determined by an enzyme‐linked lectin assay (ELLA). Strong binding was observed for tetravalent and octavalent ligands, with up to 440‐fold enhancement in potency over fucose for the octavalent cationic dendrimer 2G3 (CFuc‐LysPro)8(LysLeuPhe)4(LysLysIle)2LysHisIleNH2). Mono‐ and divalent controls showed affinities similar to fucose, highlighting the importance of multivalency for binding. Docking studies showed that the C‐fucosyl group of the dendrimers can adopt the same binding mode as fucose itself, with the peptide arms protruding from the binding pocket and establishing specific contacts with the lectin.
The patient behind the code, the care behind the patient
Authors: Vauthey Jean‐Nicolas , Zorzi Daria
Published: February 2009

Delivering a high standard of care with up‐to‐date expertise remains critical in for patients who have primary colorectal cancer and subsequently undergo hepatic resection for colorectal liver metastases. The management of colorectal cancer liver metastases requires a multidisciplinary approach that involves not only experts in hepatobiliary surgery and medical oncology but an inclusive team with subspecialty expertise in diagnostic imaging, pathology, and interventional radiology.
Lack of pathologic down‐staging with neoadjuvant chemotherapy for muscle‐invasive urothelial carcinoma of the bladder
Authors: Weight Christopher J. , Garcia Jorge A. , Hansel Donna E. , Fergany Amr F. , Campbell Steven C. , Gong Michael C. , Jones J. Stephen , Klein Eric A. , Dreicer Robert , Stephenson Andrew J.
Published: February 2009

BACKGROUND:

The postcystectomy survival benefit associated with the combination of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) neoadjuvant chemotherapy (NC) for muscle‐invasive bladder cancer has been most evident in patients who achieve a pathologic complete response. The outcome of NC and open radical cystectomy (RC) was evaluated in a contemporary cohort of patients in a tertiary referral setting.

METHODS:

From January 2006 to November 2007, 117 patients underwent open RC at Cleveland Clinic for muscle‐invasive bladder cancer, 29 (25%) of whom received NC. Patient information was obtained from a prospective database.

RESULTS:

Clinical stage at the time of diagnosis in the NC cohort was T2 in 23 (79%) and T3‐4a in 6 (21%) patients. A total of 20 (69%) patients received the combination of gemcitabine and cisplatin (GC), 4 (14%) received MVAC, and 5 (17%) received other regimens. The median interval from the time of diagnosis of muscle‐invasive bladder cancer to RC was 208 days (interquartile range, 149 days ‐327 days) in the NC cohort. Overall, only 2 patients (7%; 95% confidence interval [95% CI], 0 patients‐17 patients) achieved a pathologic complete response, 18 (62%; 95% CI, 43 patients‐81 patients) had nonorgan‐confined residual cancer, and the overall median progression‐free survival was 10.5 months (95% CI, 7 months ‐14 months).

CONCLUSIONS:

Few RC patients in these investigators' recent experience achieved a pathologic complete response with NC, and most experienced rapid disease progression. These poor outcomes may be related to the use of non‐MVAC‐based regimens or excessive delay in performing RC. In the absence of supportive data for GC in the neoadjuvant setting, MVAC remained the preferred regimen. Excessive delays in performing RC may negate the benefit of NC. Cancer 2009. © 2009 American Cancer Society.
The Breast and Cervical Cancer Prevention and Treatment Act in Georgia
Authors: Adams E. Kathleen , Chien Li‐Nien , Florence Curtis S. , Raskind‐Hood Cheryl
Published: February 2009

BACKGROUND:

Implementation of the Breast and Cervical Cancer Prevention and Treatment Act of 2000 (BCCPTA) allowed states to extend Medicaid to any woman aged <65 without insurance screened and found to need treatment either for breast or cervical cancer or for a precancerous cervical condition through the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) or in Georgia, other provider sites.

METHODS:

The authors used linked Georgia Comprehensive Cancer Registry (GCCR) and Medicaid data to test the: 1) likelihood of Medicaid enrollment in a given month and 2) time‐to‐enrollment (months) for those eventually enrolling. The authors used difference‐in‐differences analysis to estimate the effects of BCCPTA for breast or cervical cancer cases relative to a control group of women with other cancers. The authors controlled for sociodemographics, stage at diagnosis, year of diagnosis, and county level factors related to insurance levels in the area.

RESULTS:

Compared with the control cancer group, the hazard ratio of Medicaid enrollment for women with breast and cervical cancers increased post‐ vs pre‐BCCPTA implementation. The estimated effect of this increase was that out of every 1000 women with breast cancer, BCCPTA led to 1.7 more (from 2.8 to 4.5 per month) enrolling in Medicaid. The results for women with local or later stages of cervical cancer indicated that of 1000 women with these cancers, the number enrolling in a given month increased by 3.4 due to BCCPTA. Results on time‐to‐enrollment indicated that the time between cancer diagnosis and enrollment was shortened by 7 to 8 months.

CONCLUSIONS:

The Georgia Medicaid program, in response to national legislation, increased the probability of women enrolling in Medicaid earlier and in turn, likely increased their cancer treatment options. Cancer 2009. © 2009 American Cancer Society.
Role of surgical outcome as prognostic factor in advanced epithelial ovarian cancer: A combined exploratory analysis of 3 prospectively randomized phase 3 multicenter trials
Authors: du Bois Andreas , Reuss Alexander , Pujade‐Lauraine Eric , Harter Philipp , Ray‐Coquard Isabelle , Pfisterer Jacobus
Published: February 2009

BACKGROUND:

Primary surgery followed by platinum‐taxane based chemotherapy has been the standard therapy in advanced ovarian cancer. However, the prognostic role of complete and so‐called optimal and suboptimal debulking and its interaction with biological factors has not been not fully defined.

METHODS:

Exploratory analysis was conducted of 3 prospective randomized trials (AGO‐OVAR 3, 5, and 7) investigating platinum‐taxane based chemotherapy regimens in advanced ovarian cancer conducted between 1995 and 2002.

RESULTS:

A total of 3126 patients were analyzed. Approximately one‐third each fulfilled criteria for complete resection (group A), small residual tumor burden of 1‐10 mm (group B), or macroscopic residual disease exceeding 1 cm in diameter (group C). Multivariate analysis showed improved progression‐free and overall survival for group A with complete resection compared with groups B or C (P < .0001). The impact of so‐called optimal debulking as in group B showed a smaller prognostic impact compared with group C. Further independent prognostic factors for overall survival were age, performance status, grade, FIGO stage, and histology, namely the mucinous subtype. An interaction between residual tumor and some biologic factors was demonstrated.

CONCLUSIONS:

The goal of primary surgery should be complete resection. The prognostic impact of tumor biology seemed to be partially overruled by residual tumor and further evaluation of biologic factors should stratify for residual tumor. Cancer 2009. © 2009 American Cancer Society.
Conflicting Observations Resolved by a Far IR and UV/Vis Study of the NO3 Radical
Authors: Beckers Helmut , Willner Helge , Jacox Marilyn E.
Published: February 2009

Codeposition of NO and O2 diluted in Ne at 6 K yield a ON⋅⋅⋅OO complex that exhibit strong UV absorption. This complex is converted into NO3 radicals by UV irradiation, and is regenerated by radiation of visible light (see spectra).

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By codeposition of NO/Ne and O2/Ne mixtures at 6 K, weakly bound complexes between O2 and NO are formed. They exhibit a strong, structured charge transfer UV band at λmax=275 nm. The UV band disappears during UV irradiation of the neon matrix, while the visible spectrum of the NO3 radical appears. Simultaneously, the fundamental ν4 of the NO3 radical in the ${\mathop X\limits^\sim }$ 2A2′ ground state is observed in infrared absorption for the first time at 365.6 cm−1. Its 14/15N and 16/18O isotopic shifts reveal strong couplings between the two e′‐type modes of NO3, which are both active in a pseudo‐Jahn–Teller interaction with the excited ${\mathop B\limits^\sim }$ 2E′ electronic state. The dispute on the vibrational fundamentals of the NO3 radical is now concluded by the unambiguous assignment of combination bands associated with the fundamental ν4. Taking into account the observed isotopic shifts and estimated anharmonicities for ν4 and the most intense IR band of NO3 at 1492 cm−1 (ν3+ν4), the frequency of the so far not observed fundamental ν3 is estimated to be 1100±10 cm−1. A tentative assignment of the vibronic levels in the IR spectrum in the range from 1000 to 3000 cm−1 is given.
Spontaneous High‐Yield Production of Hydrogen from Cellulosic Materials and Water Catalyzed by Enzyme Cocktails
Authors: Ye Xinhao , Wang Yiran , Hopkins Robert C. , Adams Michael W. W. , Evans Barbara R. , Mielenz Jonathan R. , Zhang Y.‐H. Percival
Published: February 2009

Cocktail reception: Biohydrogen is produced in high yield from cellulosic materials and water in a one‐pot process catalyzed by up to 14 enzymes and one coenzyme. This assembly of enzymes results in non‐natural catabolic pathways. These spontaneous reactions are conducted under modest reaction conditions (32 °C and atmospheric pressure).

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Regelungen der ETB‐Richtlinie zur Begrenzung der Formaldehydemission in die Raumluft bei Verwendung von Harnstoff‐Formaldehydharz‐Ortschaum (ETB‐Ri UF‐Ortschaum)
Authors: Fechner Otto
Published: February 2009

Immer mehr Besitzer von Gebäuden mit zweischaligem Mauerwerk entscheiden sich aus energetischen Gesichtspunkten für die nachträgliche Wärmedämmung der Hohlschicht im Mauerwerk. In letzter Zeit sind vermehrt Anfragen an das DIBt gerichtet worden, die darauf hindeuten, dass es nach solchen Dämmmaßnahmen in Gebäuden zu länger anhaltenden erhöhten Formaldehydbelastungen gekommen ist. Wir nehmen dies zum Anlass, auf die Regelungen der ETB‐Ri UF‐Ortschaum sowie der in diesem Bereich erteilten Zulassungen hinsichtlich der Bestimmungen für die Verwendung hinzuweisen.

Das Deutsche Institut für Bautechnik (DIBt) erteilt etwa seit Anfang der 80er Jahre für die Herstellung und Verwendung von nachträglich in Hohlschichten von zweischaligem Mauerwerk für Außenwände eingeschäumte UF‐Ortschäume (Kerndämmung) allgemeine bauaufsichtliche Zulassungen. Nachfolgend sind die Voraussetzungen zur Beschränkung der Abgabe von Formaldehyd, die von Herstellern und Verarbeitern zu beachten sind, zusammengestellt.
Aktuelle europäische Rechtsänderungen
Authors: Abend Kerstin
Published: February 2009

Im Heft 6 der DIBt Mitteilungen ist in einem kurzen Überblick über aktuelle europäische Rechtsentwicklungen, einschließlich des Kommissionsvorschlags für eine europäische Bauprodukteverordnung sowie einer Stellungnahme des Bundesrats vom 19. September 2008 (Drucksache 400/08 (Beschluss)) zu diesem Vorschlag, berichtet worden.

Der Entwurf für eine Bauprodukteverordnung (BauPVO‐E) wird weiterhin auf europäischer Ebene unter den Mitgliedstaaten in einer sog. Rats‐Arbeitsgruppe (unter Leitung des Mitgliedstaats, der die Ratspräsidentschaft der Europäischen Union innehat, diese obliegt im ersten Halbjahr 2009 Tschechien) sowie parallel im Europäischen Parlament beraten. Aufgrund der fortgesetzten Diskussionen hat der Bundesrat einen zweiten Beschluss zum Kommissionsvorschlag gefasst. In diesem Beschluss vom 28.11.2008 (Drucksache 400/08 (Beschluss) (2)) wird die Bundesregierung gebeten, bei den Verhandlungen auf europäischer Ebene auf bestimmte Änderungen zum Verfahren der Europäischen Technischen Bewertung sowie zu den Bestimmungen der Marktüberwachung hinzuwirken. Der Beschluss ist nachfolgend abgedruckt.
Zulassungsverfahren für Laminatbodenbeläge nach DIN EN 14041
Authors: Eichler Antje
Published: February 2009

1. Hintergründe/Historie zum Zulassungsverfahren für Laminatbodenbeläge

2. DIBt/EPLF/WKI‐Projekt zur Erarbeitung von Kriterien zur Vereinfachung des Zulassungsverfahrens für Laminatbodenbeläge

3. Vorstellung der Ergebnisse des Projektes im Rahmen der DIBt‐Informationsveranstaltung “Zulassungsverfahren für Laminatbodenbeläge nach DIN EN 14041” – Erfahrungstransfer, Berichte und Informationen zum Stand und zu Änderungen im Zulassungsverfahren