bluuebunny/crossref_metadata_2025 huggingface dataset:
Reappraisal of the ‘Cullenstown Formation’: Implications for the Lower Palaeozoic tectonic history of SE Ireland
Authors: Bennett M. C. , Dunne W. M. , Todd S. P.
Published: July 2010

The structurally attenuated greenschist facies metasedimentary succession at Cullenstown Strand in south Co. Wexford comprises three formations which in stratigraphic order are (1) the Quartzite Formation, (2) the Greywacke/Quartzite Formation, and (3) the Greywacke Formation. The entire sequence is inverted and lies within the lower limb of a large scale overturned D1 anticlinal structure that closes towards the southeast. The three formations are lithologically and sedimentologically similar to the Shelmaliere Quartzite, the Cullentra Greywacke, and Newtown Greywacke Formations of the Bray Group in the Forth Mountain ‐ Ferrycarrig area that probably lie on the normal limb of the D1 structure. The Cullenstown strata are therefore considered to be part of the Bray Group in southeast Leinster, and hence Cambrian in age.

The rocks were affected by three major phases of deformation. D1 produced an overturned anticline containing an important tectonic slide. The D1 structures are modified by upright D2 and D3 structures, but from regional considerations it is argued that D1 is restricted to strata of Cambrian to Lower Ordovician age in southeast Leinster.

A model for the tectonic evolution of the southeastern part of the Leinster Basin during Cambro‐Ordovician times is presented and discussed. In this model, the southeast margin of the Leinster Basin was delineated by a mylonite zone along the northwest margin of the Precambrian Rosslare Complex. Bray and Ribband Group sediments close to the margin were deformed during the Llanvirn as a consequence of basin inversion which caused shortening and thrusting of the basin fill across the Rosslare block. The D1 compressional structures were subsequently modified during a period of extension, marked by the resumption of sedimentation and outbreak of voluminous volcanicity near the basin margin during the Llandeilo and Caradoc. The D2 and D3 structures in the Bray and Ribband Groups are an expression of later Caledonian deformation.
Timing of Cadomian and Variscan tectonothermal activity, La Hague and Alderney, North Armorican Massif: Evidence from 40Ar/39Ar mineral ages
Authors: Dallmeyer R. D. , D'Lemos R. S. , Strachan R. A.
Published: July 2010

The La Hague region of northwest France exposes Palaeo‐Proterozoic Icartian gneisses which were reworked and intruded by calc‐alkaline plutonic rocks during the Cadomian Orogeny (about 700–500 Ma). 40Ar/39Ar mineral cooling ages have been determined to clarify the timing of the regional metamorphism of orthogneisses and the emplacement of quartz diorite plutons in this region. Metamorphic amphiboles within Icartian gneisses display discordant 40Ar/39Ar apparent age spectra interpreted to result from limited Variscan (about 350–300 Ma) overprinting of intracrystalline argon systems which initially cooled through post‐metamorphic hornblende closure temperatures during the Cadomian at about 600 Ma. Igneous hornblendes from the weakly foliated Jardeheu and Moulinet quartz diorites record isotope correlation ages of 599 ± 2 and 561 ± 2 Ma, respectively. Igneous hornblende and biotite from foliated quartz diorite on the nearby Channel Island of Alderney record isotope correlation ages of about 560 Ma. The results imply that metamorphic and plutonic events in the La Hague‐Alderney region were approximately contemporaneous with those recorded on Guernsey and Sark, which are thus likely to have formed part of the same tectonic block during the Cadomian Orogeny.
The Bocchigliero Palaeozoic sequence in the context of the Calabrian–Peloritan Hercynian Range (Italy)
Authors: Acquafredda P. , Lorenzoni S. , Lorenzoni E. Zanettin
Published: July 2010

The Calabrian–Peloritan Hercynian Range includes three weakly metamorphosed Palaeozoic sequences cropping out in north‐eastern Sila (Bocchigliero sequence), southern Sila, Serre and Aspromonte (Stilo sequence), and in the Peloritan Mountains (Peloritan sequence). The work reported here considers the Bocchigliero sequence and comprises part of a geological, petrological and geochemical research programme on the Palaeozoic evolution of the Calabrian–Peloritan Arc.

The Bocchigliero sequence constitutes the lower tectonic unit of the Hercynian Caiabrian–Peloritan Range and is overthrusted by the metamorphic Mandatoriccio Unit. The Bocchigliero sequence is a terrigenous–carbonate–volcanic association, is affected byclow grade metamorphism, contains Cambro‐Ordovician fossils and extends in age from the Cambrian to the Devonian. The terrigenous material is represented by meta‐arenites and metapelites (Cambrian–Devonian); the volcanics include metatuffites (Cambrian and Ordovician), metabasalts (Cambro‐Ordovician), metaandesites and metarhyolites (Ordovician and Siluro‐Devonian); limestone beds are present in the Devonian. It is believed that the Palaeozoic Bocchigliero basin formed in the Cambrian on a continental crust in which the rocks constituting today's Mandatoriccio Unit were located at 3–8 km depth. The crustal thinning in the Cambro‐Ordovician led to fracturing and upwelling of alkaline within‐plate basaltic magmas, whereas in the Ordovician the thinning took place under conditions of higher plasticity. In this latter period an increase in temperature resulting from mantle upwelling produced crustal partial melts of andesite and rhyolite composition. In addition, this thermal uprise was responsible for regional metamorphism characterized by low pressures and by the absence of penetrative deformation. The effects of this metamorphism are well developed in the rocks of the Mandatoriccio Unit. In the Silurian and Devonian, progressive closing of the basin took place. The Palaeozoic sequence was then subjected to Variscan low pressure–low temperature metamorphism and Alpine deformation.
Basaltic magmatism related to the early stages of rifting along the Benue Trough: The Obudu dolerites of south‐east Nigeria
Authors: Ekwueme Barth N.
Published: July 2010

Dolerites of the Obudu Plateau of south‐eastern Nigeria occur predominantly as dykes cutting Precambrian basement gneisses. Minor dolerite sills have also been mapped. The dolerites are dominantly olivine tholeiites and are geochemically of the oceanic basalt type. They were emplaced in a within‐plate tectonic setting and yield a 40Ar/39Ar plateau age of 140.5 ± 0.7 Ma, which is interpreted as the age of their emplacement. This age indicates that the Obudu dolerites are the products of basic magmatism related to the early stages of rifting along the Benue Trough of Nigeria. The Obudu dolerites are comparable with Mesozoic tholeiitic dykes of the northern Amazon craton, whose intrusion preceded the break‐up of Africa and South America.
The Baltica–lapetus passive margin dyke complex in the Sarektjåkkå Nappe, northern Swedish Caledonides
Authors: Svenningsen Olaf M.
Published: July 2010

The polymetaphoric Seve Nappe Complex (SNC) of the Scandinavian Caledonides contains sequences representing the passive margin between continental Baltica and the Iapetus Ocean. The Sarektjåkkå Nappe in the SNC consists of sedimentary rocks intruded by mafic dykes that constitute 70–80 per cent of the nappe and frequently form sheeted dyke complexes. The internal parts of the Sarektjåkkå Nappe escaped penetrative deformation and metamorphism during Caledonian nappe transport and primary igneous relations are preserved. A sequence of nine dyke generations have been identified in a sheeted dyke complex in one well exposed area (Favorithällen). The alteration in this dyke complex was triggered by heat in connection with the dyke emplacement; overprint from Caledonian regional metamorphism cannot be demonstrated. Neither the relative age of a dyke in the dyke complex, nor the contact metamorphism caused by the emplacement of subsequent dykes had any detectable effect on the chemical composition of the dykes. The chemical composition of the diabases thus reflects the composition of the magma. Xenoliths of diabase and various types of gabbro are not uncommon and represent wallrock sampling during intrusion. Irregular patches of static alteration reveal the presence of fluids (brines), probably derived from metaevaporites in the wallrock, during the period of dyke intrusion. Scapolite rich dioritic–quartz dioritic inclusions and veins formed by partial or complete melting of wallrock xenoliths. A Sm–Nd age determination indicates a crystallization age of 573 ± 74 Ma for the Sarek diabase, coinciding with the Vendian–Early Cambrian period of global continental break‐up. Geophysical data from continent–ocean transitions at modern passive margins agree well with the structure of the Sarektjåkkå Nappe. It is suggested that the Sarek dyke complexes were intruded during the initial stages of seafloor spreading in the Iapetus or pre‐Iapetus Ocean.
Temporal expression pattern of adhesion genes in human oral mucosal keratinocytes on type IV collagen‐coated titanium
Authors: Takeuchi Satoru , Matsunaga Taku , Yamamoto Gou , Baba Kazuyoshi , Tachikawa Tetsuhiko
Published: July 2010

The cell adhesion extracellular matrix (ECM), and the cell adhesive system mediate various adhesion molecules. Cell adhesion regulates proliferation and differentiation. However, the cell adhesive systems between titanium and epithelial cells are still not clearly understood. In this study, we cultured human epithelial cells on type IV collagen‐coated titanium (TiCol‐4) and non‐coated titanium (Ti). We used titanium disks of 30 mm diameter and 1.0 mm thickness. The titanium disks were first abraded using #800, #1200, #2400, and #4000 diamond pads and 0.3 μm alumina, and then washed with acetone, ethanol, and ultra‐pure water in an ultrasonic cleaner for 10 min each. Human oral keratinocytes (hOMK) were seeded with 5.0 × 104 cells on TiCol‐4 and Ti and placed in 6‐well culture dishes. The cell adhesion examination was conducted with a Cell Coulter Counter after 1, 3, and 5 h. hOMK were observed using scanning electron microscopy (SEM). Real‐time PCR was performed with four primers: gene laminin β3, integrin β4, integrin α1, and integrin α3. The results suggest that TiCol‐4 could be used as a means for obtaining better hOMK than Ti. Type IV collagen could provide an excellent substratum for hOMK attachment on titanium surfaces. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Platelet‐rich fibrin modulates the expression of extracellular signal‐regulated protein kinase and osteoprotegerin in human osteoblasts
Authors: Chang I‐Chang , Tsai Chung‐Hung , Chang Yu‐Chao
Published: July 2010

Platelet‐rich fibrin (PRF) by Choukroun's technique is produced in a totally natural manner, without using anticoagulant during blood harvest nor bovine thrombin and calcium chloride for platelet activation and fibrin polymerization. When delicately pressed between two gauzes, the PRF clot becomes a strong membrane with high potential in clinical application and tissue engineering. In this study, blood collection was carried out from healthy volunteers. Osteoblast cell line U2OS was used to evaluate the cell proliferation resulting from PRF by using colorimetric assay. Western blot was employed to evaluate the expression of phosphorylated extracellular signal‐regulated protein kinase (p‐ERK), receptor activator of nuclear factor‐kappa B ligand (RANKL), and osteoprotegerin (OPG) in U2OS cells. PRF was found to increase osteoblast proliferation during 5 day incubation period (p < 0.05). PRF was found to increase ERK phosphorylation in U2OS cells (p < 0.05). OPG was significantly elevated by the stimulation with PRF (p < 0.05). However, there was no significant change in RANKL expression (p > 0.05). Taken together, PRF can stimulate osteoblasts proliferation. The activation of p‐ERK and OPG expression by PRF suggests a potential role for new bone formation. The application of PRF may provide the benefit for the bone regeneration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Inequivalence of substitution pairs in hydroxynaphthaldehyde: A theoretical measurement by intramolecular hydrogen bond strength, aromaticity, and excited‐state intramolecular proton transfer reaction
Authors: Mahanta Subrata , Paul Bijan Kumar , Balia Singh Rupashree , Guchhait Nikhil
Published: July 2010

The inequivalence of substitution pair positions of naphthalene ring has been investigated by a theoretical measurement of hydrogen bond strength, aromaticity, and excited state intramolecular proton transfer (ESIPT) reaction as the tools in three substituted naphthalene compounds viz 1‐hydroxy‐2‐naphthaldehyde (HN12), 2‐hydroxy‐1‐naphthaldehyde (HN21), and 2‐hydroxy‐3‐naphthaldehyde (HN23). The difference in intramolecular hydrogen bond (IMHB) strength clearly reflects the inequivalence of substitution pairs where the calculated IMHB strength is found to be greater for HN12 and HN21 than HN23. The H‐bonding interactions have been explored by calculation of electron density ρ(r) and Laplacian ∇2ρ(r) at the bond critical point using atoms in molecule method and by calculation of interaction between σ* of OH with lone pair of carbonyl oxygen atom using NBO analysis. The ground and excited state potential energy surfaces (PESs) for the proton transfer reaction at HF (6‐31G**) and DFT (B3LYP/6‐31G**) levels are similar for HN12, HN21 and different for HN23. The computed aromaticity of the two rings of naphthalene moiety at B3LYP/6‐31G** method also predicts similarity between HN12 and HN21, but different for HN23. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Optimizing energy functions for protein–protein interface design
Authors: Sharabi Oz , Yanover Chen , Dekel Ayelet , Shifman Julia M.
Published: July 2010

Protein design methods have been originally developed for the design of monomeric proteins. When applied to the more challenging task of protein–protein complex design, these methods yield suboptimal results. In particular, they often fail to recapitulate favorable hydrogen bonds and electrostatic interactions across the interface. In this work, we aim to improve the energy function of the protein design program ORBIT to better account for binding interactions between proteins. By using the advanced machine learning framework of conditional random fields, we optimize the relative importance of all the terms in the energy function, attempting to reproduce the native side‐chain conformations in protein–protein interfaces. We evaluate the performance of several optimized energy functions, each describes the van der Waals interactions using a different potential. In comparison with the original energy function, our best energy function (a) incorporates a much “softer” repulsive van der Waals potential, suitable for the discrete rotameric representation of amino acid side chains; (b) does not penalize burial of polar atoms, reflecting the frequent occurrence of polar buried residues in protein–protein interfaces; and (c) significantly up‐weights the electrostatic term, attesting to the high importance of these interactions for protein–protein complex formation. Using this energy function considerably improves side chain placement accuracy for interface residues in a large test set of protein–protein complexes. Moreover, the optimized energy function recovers the native sequences of protein–protein interface at a higher rate than the default function and performs substantially better in predicting changes in free energy of binding due to mutations. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
A large decoy set of protein–protein complexes produced by flexible docking
Authors: Launay Guillaume , Simonson Thomas
Published: July 2010

Computational methods are needed to help characterize the structure and function of protein–protein complexes. To develop and improve such methods, standard test problems are essential. One important test is to identify experimental structures from among large sets of decoys. Here, a flexible docking procedure was used to produce such a large ensemble of decoy complexes. In addition to their use for structure prediction, they can serve as a proxy for the nonspecific, protein–protein complexes that occur transiently in the cell, which are hard to characterize experimentally, yet biochemically important. For 202 homodimers and 41 heterodimers with known X‐ray structures, we produced an average of 1217 decoys each. The structures were characterized in detail. The decoys have rather large protein–protein interfaces, with at least 45 residue–residue contacts for every 100 contacts found in the experimental complex. They have limited intramonomer deformation and limited intermonomer steric conflicts. The decoys thoroughly sample each monomer's surface, with all the surface amino acids being part of at least one decoy interface. The decoys with the lowest intramonomer deformation were analyzed separately, as proxies for nonspecific protein–protein complexes. Their interfaces are less hydrophobic than the experimental ones, with an amino acid composition similar to the overall surface composition. They have a poorer shape complementarity and a weaker association energy, but are no more fragmented than the experimental interfaces, with 2.1 distinct patches of interacting residues on average, compared to 2.6 for the experimental interfaces. The decoys should be useful for testing and parameterizing docking methods and scoring functions; they are freely available as PDB files at http://biology.polytechnique.fr/decoys. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Two cases of vasa previa diagnosed prenatally using three‐dimensional ultrasonography
Authors: Mabuchi Yasushi , Yamoto Mareo , Minami Sawako , Boshi Eiji , Yagi Shigetaka , Oba Nami , Tanaka Kazuharu , Umesaki Naohiko
Published: July 2010

We report two cases in which we describe the impact of sonography (US) in the management of vasa previa. In the first case, with two‐dimensional US, the diagnosis of vasa previa was made at 21 weeks gestation. In the second case, using three‐dimensional US, the diagnosis of vasa previa was made at 19 weeks gestation. An elective Cesarean section was carried out at 34 weeks in both cases. Diagnosis of vasa previa is critical when low‐lying placenta or velamentous insertion of the umbilical cord is detected during the pregnancy. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:389‐392, 2010
Doppler sonography of ocular and carotid arteries in Behçet patients
Authors: Akçar Nevbahar , Göktekin Feyza , Özer Ahmet , Korkmaz Cengiz
Published: July 2010

Purpose.

To evalute by Doppler sonography carotid and ocular hemodynamics in Behçet disease with and without ocular involvement.

Methods.

Seventy‐six patients with Behçet disease (BD) were separated into three groups: with active uveitis, with inactive uveitis, and without uveitis, and compared with 23 controls. We used duplex Doppler sonography to measure peak systolic (PSV), end‐diastolic (EDV), and time‐averaged mean (Vmean) blood flow velocity in the ophthalmic, central retinal (CRA), temporal posterior ciliary, nasal posterior ciliary (NPCA), common carotid (CCA), internal carotid (ICA) arteries, and maximum flow velocity (Vmax) in the central retinal veins. We then calculated resistance and pulsatility indexes of all arteries. Comparisons were carried out by two‐way ANOVA and Holm‐Sidak method.

Results.

Only two patients (2.6%) had atherosclerotic plaques, without significant hemodynamic consequence. Patients with uveitis had significantly lower ICA PSV and EDV (p < 0.05), and lower CRA PSV, EDV, and Vmean (p < 0.001) than controls. Patients with active uveitis had lower NPCA PSV and EDV than patients without uveitis or controls (p < 0.01). There were no differences in temporal posterior ciliary, ophthalmic, and CCA PSV, EDV, and in Vmean between groups (p > 0.05). Patients with uveitis had lower central retinal veins Vmax than patients without uveitis and than controls (p < 0.01). Resistance index, pulsatility index of retrobulbar arteries, CCA, and ICA were similar in the four groups (p > 0.05).

Conclusions.

Patients with Behçet disease and ocular involvement have lower CRA, CRV, NPCA, and ICA blood flow velocities than healthy volunteers. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound, 2010
2,1‐Benzisothiazoline 2,2‐dioxide and derivatives
Authors: Chiarino Dario , Contri Anna Maria
Published: July 2010

Synthesis of new 2,1‐benzisothiazoline 2,2‐dioxides 1 and some of its benzene ring substitution derivatives was accomplished by two different methods of cyclisation. Also a number of new N‐substituted derivatives, obtained by treatment of 1 and analogues with aliphatic and aromatic acid chlorides are described.
Imidazolyl derivatives of the chroman ring 3
Authors: Cozzi Paolo , Pillan Antonio
Published: July 2010

The synthesis of 2‐methyl‐3‐(1‐methyl‐1H‐imidazol‐2‐yl)‐4H‐1‐benzopyran‐4‐ones 4 is described starting from 2‐acetoxybenzoyl chlorides and 1,2‐dimethylimidazole. Chromones 4 undergo alkaline ring opening to the corresponding 1‐(2‐hydroxyphenyl)‐2‐(1‐methyl‐1H‐imidazol‐2‐yl)ethenols 5 which give ring closure to 2‐substituted 3‐(1‐methyl‐1H‐imidazol‐2‐yl)‐4H‐1‐benzopyran‐4‐ones or 2,3‐dihydro‐3‐(1‐methyl‐1H‐imidazol‐2‐yl)‐4H‐1‐benzopyran‐4‐ones. The corresponding chromanols and chromenes can be easily obtained from chromones 4.
N‐demethylation of (±)‐6β‐acetoxy‐3‐tropinone. Synthesis of (±)‐6β‐acetoxynortropane
Authors: He Xiao‐Shu , Brossi Arnold
Published: July 2010

Nortropinone 5, prepared from 3 by N‐demethylation with trichloroethyl chloroformate, followed by deprotection of carbamate 4 with zinc in acetic acid, served as a starting material to prepare the N‐protected 6‐acetoxy ketones 7 and 9–12, and alcohols 6 and 8. Nortropane 16 was prepared from 3 by decarbonylation via dithioketal 13 followed by N‐demethylation, and from 10 by decarbonylation via dithioketal 14. When ethanol was used in the desulfurization of 14 instead of tetrahydrofuran, substantial amounts of the N‐ethylated amine 17 were produced.
Thermal rearrangement of some 3‐alkyl‐2‐aryltetrahydro‐1,3‐oxazine N‐oxides. Synthesis of 2‐alkyl‐7‐aryltetrahydro‐1,6,2‐dioxazepines
Authors: Le Lann Martine , Saba Shahrokh , Shoja Massud
Published: July 2010

Several 2‐alkyl‐7‐aryltetrahydro‐1,6,2‐dioxazepines 5a‐i have been synthesized by a Meisenheimer‐type rearrangement of 3‐alkyl‐2‐aryltetrahydro‐1,3‐oxazine N‐oxides 4a‐i. These dioxazepines have not been previously described and for the first time compounds with the tetrahydro‐1,6,2‐dioxazepine ring‐system have been made available. The structure assigned to members of this novel heterocycle is based on elemental analysis, infrared, and 1H nmr spectral evidence. Further definitive evidence for the structure of these heterocycles is provided by an X‐ray crystallographic analysis of 5c.
Identification of an impurity in synthetically prepared GAZT: 4″,5″‐dehydro‐GAZT
Authors: Koble Cecilia S. , Hall William R. , Styles Virgil L. , Rideout Janet L. , Minick Doug , Cichetti James , Johnson Robert L. , Crouch Ronald C. , Martin Gary E.
Published: July 2010

A minor impurity was recorded by hplc during the final purification of synthetically prepared samples of the 5′‐0‐glucuronide of azidothymidine (GAZT). Following isolation of a small quantity of this impurity by hplc, elucidation of the structure was undertaken. A combination of two‐dimensional nmr methods in conjunction with infrared spectroscopy and mass spectrometry were utilized to unequivocally identify the impurity as the 4″,5″‐dehydro‐5′‐O‐glucuronide of AZT (DGAZT).
Testing of Raman spectroscopy as a non‐invasive tool for the investigation of glass‐protected pastels
Authors: Caggiani Maria Cristina , Colomban Philippe
Published: July 2010

Five French pastels and a sanguine drawing dating from the 17th to the 20th century were studied by Raman spectroscopy. Different operative conditions were used: the pastels were investigated through their protective glass, and the results obtained were compared with those obtained after removing the glass and after sampling a micrometric particle of pigment. Different parameters (wavelengths, powers of excitation and objectives) were tested in order to assess the optimal procedure of analysis for this fragile work of art. The results obtained for black (carbons), yellow (chrome/cobalt yellow), red (lead oxide, vermillion, orpiment), brown (red lead and chrome yellow), blue (Prussian blue, lapis lazuli/ultramarine), green (mixture of above blue and yellow pigments) and white (calcite, lead white, anatase) pigments are presented and the consistency of the pigments' period of use with the dating proposed for each pastel is evaluated. In one of the pastels, the blackening of the carnation colour made of an unstable mixture of lead white, red lead and vermilion was studied. Copyright © 2010 John Wiley & Sons, Ltd.
Correlation Between Crystallinity and Solar‐Cell Efficiency of the Low‐Bandgap Polymer PDDTP
Authors: Renz Joachim A. , Ashraf Raja Shahid , Erb Tobias , Shokhovets Sviatoslav , Gobsch Gerhard , Klemm Elisabeth , Hoppe Harald
Published: July 2010

Polymer/fullerene bulk heterojunction solar cells consisting of PDDTP:PCBM blends have been investigated and optimized. The structural properties of the photoactive layers were studied by GID‐XRD, which revealed a pronounced response of photovoltaic parameters on the polymer crystallinity. In addition to P3HT, another donor polymer was found that develops crystalline domains upon annealing. We found a clear correlation between annealing time, power conversion efficiency, and polymer crystallinity. The PDDTP crystallization ability is a promising property. This is a first step toward the synthesis of low‐bandgap polymers, which likewise show the ability to form crystalline domains and may therefore lead to a substantial increase in efficiency.

magnified image
Rendering Hyperbranched Polyglycerol Adjustably Thermoresponsive by Adamantyl Modification and Host/Guest Interaction
Authors: Sun Xiaoyi , Zhou Yongfeng , Yan Deyue
Published: July 2010

A novel thermoresponsive polymer based on adamantyl‐terminated hyperbranched polyglycerol (HPG‐AD) is reported. The hydroxy‐terminated hyperbranched polyglycerol (HPG) is functionalized by esterification of HPG with 1‐adamantanecarbonyl chloride. The resulting HPG‐AD shows interesting lower critical solution temperature (LCST) phase transitions in aqueous solution, depending on polymer concentration and AD graft ratio. In addition, the LCST transition can be controlled by adding various amounts of β‐cyclodextrin (β‐CD) by a host/guest interaction. The adjustable thermoresponsive behaviors are studied by UV‐vis spectroscopy and dynamic light scattering.

magnified image
Synthesis of Poly(lactide)s with Modified Thermal and Mechanical Properties
Authors: Becker Jan M. , Pounder Ryan J. , Dove Andrew P.
Published: July 2010

The use of poly(lactide)‐based materials is, in part, limited by their physical and mechanical properties. This article reviews the methods that have been employed to enable enhancement of the materials properties through synthetic manipulation of the polymer structure including block copolymer synthesis and modification of the lactide monomer structure, focusing on the application of ring‐opening polymerization. In turn the effect of these structural modifications on the properties of the resultant materials are reported.

magnified image
Cell‐mediated Delivery and Targeted Erosion of Vascular Endothelial Growth Factor‐Crosslinked Hydrogels
Authors: Kim Sung Hye , Kiick Kristi L.
Published: July 2010

We have previously reported a novel polymeric delivery vehicle that is assembled via interaction between heparin and the vascular endothelial growth factor (VEGF). Here, the cell‐responsiveness of this hydrogel—including the delivery of VEGF in response to VEGFR‐2 overexpressing PAE/KDR cells (porcine aortic endothelial cells (PAE) equipped with the transcript for the kinase insert domain receptor (KDR)), consequent erosion of the hydrogel matrix, and cellular response—are highlighted. The release of VEGF and hydrogel erosion reached 100% only in the presence of PAE/KDR. The [PEG‐LMWH/VEGF] hydrogel (PEG = poly(ethylene glycol), LMWH = low molecular weight heparin) correspondingly prompted increases in VEGFR‐2 phosphorylation and proliferation of PAE/KDR cells. This study proves that growth factor‐crosslinked hydrogels can liberate VEGF in response to specific receptors, causing gel erosion and desired cell responses. The promise of these approaches in therapeutic applications, including targeted delivery, is suggested.

magnified image
Diketopyrrolopyrroles as Acceptor Materials in Organic Photovoltaics
Authors: Karsten Bram P. , Bijleveld Johan C. , Janssen René A. J.
Published: July 2010

In the search of new electron acceptor, n‐type materials for organic solar cells that combine a strong absorption over a broad range with good electrical characteristics, the use of diketopyrrolopyrrole (DPP) derivatives with low reduction potentials is explored. A series of small molecule DPP derivatives is presented and the compounds are tested as electron acceptors in combination with poly(3‐hexylthiophene) (P3HT) as the donor material. Working photovoltaic devices are obtained that show a photoresponse in the wavelength region where the DPP molecules absorb. The best device shows a power conversion efficiency of 0.31% in simulated solar light, with a photon‐to‐electron conversion efficiency of ∼10% up to 700 nm. The efficiency seems to be limited by the coarse morphology of the blend.

magnified image
Effect of Coordination on the Glucose‐Responsiveness of PEG‐b‐(PAA‐co‐PAAPBA) Micelles
Authors: Wang Beilei , Ma Rujiang , Liu Gan , Liu Xiaojun , Gao Yaohua , Shen Junyang , An Yingli , Shi Linqi
Published: July 2010

Poly(ethylene glycol)‐block‐poly(acrylic acid) (PEG‐PAA) is modified by 3‐aminophenylboronic acid (APBA) with different modification degrees, such as PEG114‐b‐(PAA0.37‐co‐PAAPBA0.63)170, PEG114‐b‐(PAA0.23‐co‐PAAPBA0.77)170 and PEG114‐b‐(PAA0.02‐co‐PAAPBA0.98)170. Micelles self‐assembled from these three copolymers possess glucose‐responsiveness at varying pH values. Micelles self‐assembled from PEG114‐b‐(PAA0.37‐co‐PAAPBA0.63)170 have glucose‐responsiveness at the physiological pH (7.4), endowing them with potential applications in the treatment of diabetes. 11B magic‐angle spinning nuclear magnetic resonance (11B MAS NMR) analysis indicates that interactions between PAAPBA segments and PAA segments induce boron changes from the trigonal planar form to the tetrahedral form, resulting in glucose‐responsiveness of PEG114‐b‐(PAA0.37‐co‐PAAPBA0.63)170 micelles at pH 7.4.

magnified image
Biomimetic Mussel Adhesive Inspired Clickable Anchors Applied to the Functionalization of Fe3O4 Nanoparticles
Authors: Goldmann Anja S. , Schödel Christine , Walther Andreas , Yuan Jiayin , Loos Katja , Müller Axel H. E.
Published: July 2010

The functionalization of magnetite (Fe3O4) nanoparticles with dopamine‐derived clickable biomimetic anchors is reported. Herein, an alkyne‐modified catechol‐derivative is employed as the anchor, as i) the catechol‐functional anchor groups possess irreversible covalent binding affinity to Fe3O4 nanoparticles, and ii) the alkyne terminus enables further functionalization of the nanoparticles by the grafting‐onto approach with various possibilities offered by ‘click’ chemistry. In the present work, azido‐end group functionalized Rhodamine and poly(ethylene glycol) (PEG) are utilized to coat the iron oxide nanoparticles to make them fluorescent and water soluble.

magnified image
Multifunctional Poly(2‐oxazoline) Nanoparticles for Biological Applications
Authors: Kempe Kristian , Vollrath Antje , Schaefer Hendrik W. , Poehlmann Tobias G. , Biskup Christoph , Hoogenboom Richard , Hornig Stephanie , Schubert Ulrich S.
Published: July 2010

New multifunctional copoly(2‐oxazoline) nanoparticles were prepared for cell studies. The polymer contains double‐bond side chains as potential reaction sites for “thio”‐click reactions as well as a fluorescein label covalently bound to the polymer backbone. Using the nanoprecipitation technique, spherical nanoparticles of 200–800 nm were obtained. Confocal laser scanning microscopy measurements revealed the cellular uptake of the nanoparticles.

magnified image
Dopamine transporter SPECT: How to remove subjectivity?
Authors: Scherfler Christoph , Nocker Michael
Published: July 2010

Clinical criteria enable accurate and reliable diagnosis of parkinsonian syndromes when cardinal clinical features are fully developed. Single photon emission computed tomography (SPECT) investigating the striatal dopamine transporter (DAT) status have been suggested to increase the diagnostic accuracy in uncertain parkinsonian syndromes such as isolated tremor symptoms not fulfilling essential tremor criteria, as well as drug‐induced, vascular and psychogenetic parkinsonism. Several approaches for the analysis of the striatal DAT distribution have been tested for their ability to analyze and quantify SPECT images. Visual assessment of DAT binding and semiquantitative analysis using region of interests have been recommended by Nuclear Medicine Associations to be incorporated in the routine work‐up of DAT‐SPECT. Besides these observer dependent approaches, fully automated image‐analysis techniques have been validated in the clinical setting. Their potential as tools to improve the diagnostic accuracy in patients presenting with parkinsonian features is reviewed here. © 2009 Movement Disorder Society
Callosal tissue loss in multiple system atrophy—A one‐year follow‐up study
Authors: Minnerop Martina , Lüders Eileen , Specht Karsten , Ruhlmann Jürgen , Schimke Nicole , Thompson Paul M. , Chou Yi Y. , Toga Arthur W. , Abele Michael , Wüllner Ullrich , Klockgether Thomas
Published: July 2010

Multiple system atrophy (MSA) is a neurodegenerative disease not only affecting the basal ganglia, brainstem, cerebellum, and intermediolateral cell columns of the spinal cord but also the cerebral cortex. Clinically, cerebellar (MSA‐C) and parkinsonian variants of MSA (MSA‐P) are distinguished. We investigated 14 MSA patients (10 MSA‐C, 4 MSA‐P, men: 7, women: 7; age: 61.1 ± 3.3 years) and 14 matched controls (men: 7, women: 7; age: 58.6 ± 5.1 years) with voxel‐based morphometry (VBM) to analyze gray and white matter differences both at baseline and at follow‐up, 1 year later. Baseline comparisons between patients and controls confirmed significantly less gray matter in MSA in the cerebellum and cerebral cortex, and significantly less white matter in the cerebellar peduncles and brainstem. Comparisons of tissue‐loss profiles (i.e., baseline versus follow‐up) between patients and controls, revealed white matter reduction in MSA along the middle cerebellar peduncles, reflecting degeneration of the ponto‐cerebellar tract as a particularly prominent and progressive morphological alteration in MSA. Comparisons between baseline and follow‐up, separately performed in patients and controls, revealed additional white matter reduction in MSA along the corpus callosum at follow‐up. This was replicated through additional shape‐based analyses indicating a reduced callosal thickness in the anterior and posterior midbody, extending posteriorly into the isthmus. Callosal atrophy may possibly reflect a disease‐specific pattern of neurodegeneration and cortical atrophy, fitting well with the predominant impairment of motor functions in the MSA patients. © 2010 Movement Disorder Society
Soft Skills für wissenschaftliche Führungskräfte
Authors: Schalley Christoph
Published: July 2010

Ein Programm der Schering‐Stiftung vermittelt angehenden Hochschullehrern Kenntnisse und Fähigkeiten jenseits ihres Faches.
Leitfaden für den Laboralltag
Authors: Brock Thomas
Published: July 2010

Die Laborrichtlinien dienen seit über 50 Jahren als Hilfen für die Arbeit im Labor dazu, Unfälle zu vermeiden. In diesem Jahr erscheinen sie in überarbeiteter Fassung.
Unternehmerisch denken und handeln lernen
Authors: Bräse Stefan
Published: July 2010

Ein Kurs Chemical Entrepreneurship im Karlsruher Institut für Technologie will Gründerbewusstsein schaffen und stärken sowie unternehmerische Fähigkeiten vermitteln.
Mit Licht Tumoren auf der Spur
Authors: Schlücker Sebastian
Published: July 2010

Optische Methoden wie die oberflächenverstärkte Raman‐Streuung halten Einzug in der biomedizinischen Diagnostik. Biofunktionalisierte Nanopartikel kombiniert mit Laseranregung weisen selektiv und hochempfindlich Zielmoleküle nach.
Nanoreaktoren, Nanokapseln und Nanobomben
Authors: Landfester Katharina
Published: July 2010

Polymere Nanopartikel und Nanokapseln lassen sich über Miniemulsionen darstellen. Der Vorteil dieses Prozesses liegt darin, dass die entstehenden Polymere und Polymerstrukturen nicht oder nur sehr schwer über andere Heterophasenpolymerisationen zugänglich sind.
Warum Papier löchrig wird
Authors: Potthast Antje , Henniges Ute , Banik Gerhard
Published: July 2010

Cellulose wird als Hauptbestandteil von Papier und Textilien seit Jahrtausenden verwendet. Restaurierung und Konservierung wertvoller historischer cellulosischer Objekte gehen mit Neuerungen in der Cellulosechemie und ‐analytik Hand in Hand.
Tetrazole für den sicheren Knall
Authors: Klapötke Thomas
Published: July 2010

Hochenergetische, aber kinetisch hinreichend stabile Verbindungen sind die Grundlage für nichtnukleare Explosivstoffe. Seit der Erforschung des Nitroglycerins durch Alfred Nobel arbeiten Chemiker an der Synthese noch leistungsfähigerer, aber auch sicherer und umweltverträglicherer Explosivstoffe.
Die Georg‐Manecke‐Stiftung
Authors: Zörlein Caroline
Published: July 2010

Innerhalb der letzten 15 Jahre hat die Gesellschaft Deutscher Chemiker sechs Stiftungen eingerichtet, die sie treuhänderisch verwaltet. Diese unselbständigen gemeinnützigen Stiftungen fördern mit Auszeichnungen und Stipendien den wissenschaftlichen Nachwuchs auf unterschiedlichen Gebieten der Chemie.
Modeling individuals' behavior: Evaluation of a policymaker's tool
Authors: Gustman Alan L.
Published: July 2010

With a continuous decline in the cost of manipulating data and a continuous increase in the richness of data banks, policymakers have increasing opportunities to build and apply so‐called microsimulation models—models that attempt to simulate the behavior of the individuals in a large population under a specified program. The efforts of the Department of Labor to use a model in evaluating proposed changes in the unemployment insurance system point up both the power and the weaknesses of such models. Any user who applies these models without attempting to understand which of their strengths and weaknesses are most important for analyzing the problem at hand is asking for trouble. Easy to use or not, these models are not user‐friendly.
Using knowledge for control in fragmented policy arenas
Authors: Weiss Janet A. , Gruber Judith E.
Published: July 2010

Analysts and researchers typically value knowledge for its contributions to the wisdom of policy action. Policymakers, however, typically value knowledge for its contributions to the exercise of political control. Our research on flows of knowledge among federal, state, and local education agencies documents how knowledge may increase the effectiveness of various control strategies. In these cases, knowledge is not intended to enhance rationality; it may or may not. It is intended to enhance control, and it does. Knowledge for control is particularly useful to policymakers who seek to intervene in policy arenas characterized by fragmented authority and widely dispersed resources.
The politics of french nuclear development
Authors: Fagnani Jeanne , Moatti Jean‐Paul
Published: July 2010

France has evolved a nuclear energy policy markedly different from that of the United States and other technologically advanced western nations. The roots of the difference lie in French governmental processes which allow French officials to impose policy in the face of resistant public opinion, in the convergent economic interests of the French nuclear industry and labor, and in the French aspirations for technological achievement. But economic factors—rather than political ones—are obliging France to reduce its plans for future growth of the industry.
Subsidizing the affluent: The case of medical education
Authors: Lee Robert H.
Published: July 2010

State and federal funds are important sources of revenue for medical schools, and a strong case can be made for public support for these institutions. Although the federal role is more widely known, the states in fact provide the bulk of direct support for medical training. The nature of aid from the two sources differs in significant ways. Most federal aid supports research or patient care, but much of state aid goes to support unconditional tuition subsidies. The primary beneficiaries of these subsidies are relatively affluent nonminority students who are beginning lucrative careers in the medical field—careers that would be lucrative even if no subsidies were provided. Nor does it appear that general subsidies are needed to attract poor and minority applicants. While targeted loans and scholarships to individuals may be justified, general tuition subsidies are not.
State support under the new federalism
Authors: Luce Thomas , Pack Janet Rothenberg
Published: July 2010

The new federalism will reduce total intergovernmental revenues to local governments. The reduction will be due to both the transfer to the states of much of the federal aid which previously flowed directly to local governments and reductions in total federal aid levels. Pass‐through requirements on the shifted aid will not affect this general result but may soften the impact in many states. Because of differences in the extent to which state governments substitute federal pass‐through aid for state aid from own‐source revenues and in the degree to which different sources of revenues are treated differently by the states, local revenue reductions will vary greatly from state to state. The losses for local governments will range from 100% of the shifted aid in some states to as little as 15–20% in others.
Planning science and technology policy
Authors: Hollick Ann L.
Published: July 2010

Long‐range policy planning for international scientific and technological affairs has been hindered by a variety of problems. One is the overall crisis‐response nature of foreign policymaking and another is the difficulty of developing technical information needed for sound forecasts. Within the State Department the record of attempts to establish systematic planning amply demonstrates the problems. Nevertheless, a number of key conclusions can be drawn from the few successful experiments in policy planning: An effective planning staff should combine the skills of both foreign policy specialists and scientists; planners should be closely familiar with, but not involved in, operations; the planning role requires consistent support from senior officials; the power to influence budgets significantly strengthens the planning function.
Coping with transborder penetration: The politics of television
Authors: Quester George H.
Published: July 2010

International conflicts are brewing over the transmission of television signals across international boundaries. The dispute is illustrative of an increasing range of cases in which the actions of one national economy penetrate deeply into another, and in which national interests and national values conflict. In this instance, the opposition to such signals stems not only from authoritarian regimes but also from democratically elected governments. The U.S. government defends such transmissions on the basis of strongly held U.S. values, including the concept of maximum choice for viewers and the fear that regulation of an entertainment medium may lead the way to government censorship. U.S. commercial interests are also involved. The conflict promises to grow more acute in time; yet the U.S. government finds it extremely difficult to agree on mitigating measures with other nations in areas of policy such as television, that is, areas that entail both domestic and foreign considerations.
Understanding political risk in investment planning
Authors: Bodde David L. , Lewis David L.
Published: July 2010

In 1982, the Congress authorized $11 billion to modernize the nation's air traffic control system—one of the largest infrastructure investments since the building of the interstate highway system. Although this investment appears to offer a large and robust return, the economic results depend strongly on productivity gains through system consolidation. It is uncertain what balance the Congress will strike between the long‐term, widely shared benefits of greater productivity and the immediate job losses from system consolidation. This risk can be included in the calculus of expected return through Monte Carlo analysis. When this is done, the expected return drops very close to the 10% hurdle rate that the government often uses for such projects. This method of integrating political risk can be applied to any investment, public or private, for which political action joins the customary economic and technical uncertainties in affecting the outcome.
Economics and politics of deregulation
Authors: Vietor Richard H. K. , Davidson Dekkers L.
Published: July 2010

The Access Charge Plan, a marginal‐cost pricing system for long‐distance telephone sewice, was devised by the Federal Communications Commission in 1982 to facilitate the transition from regulated monopoly to competition. In little more than a year after the plan was proposed, as the plan's distributive and competitive impacts were recognized by a host of stakeholders and political interests, a flood of opposition different from the system that had previously existed, nevertheless continued to reflect some of the objectives of the past regime, including subsidies to residential users and some shelter for AT&T's principal competitors. The strength of the political process that produced these modifications was due part to elements in the original FCC proposal that were not essential to its central purpose. swamped the initiative. What emerged, although distinctly different from the system that had previously existed, nevertheless continued to reflect some of the objectives of the past regime, including subsidies to residential users and some shelter for AT&T's principal competitors. The strength of the political process that produced these modifications was due part to elements in the original FCC proposal that were not essential to its central purpose.
Mediating science‐intensive policy disputes
Authors: Ozawa Connie P. , Susskind Lawrence
Published: July 2010

Public policy disputes involving complex scientific issues usually entail conflicts not only over those scientific issues, but also over the distribution of gains and losses. The presence of scientific or technical dimensions to a dispute should not be allowed to mask underlying distributional considerations. On the other hand, science‐intensive disputes require special attention. Merely resolving distributional conflicts without incorporating the best scientific judgment will produce unwise and potentially dangerous results. The usual adversarial approach that characterizes the handling of such disputes by agencies and courts is less than ideal for creating an understanding of scientific evidence or the resolution of scientific differences. A process of mediation, already applied in a number of significant cases, offers strong promise as a superior approach.
Public policy evaluation in France
Authors: Nioche Jean‐Pierre , Poinsard Robert
Published: July 2010

The future of public policy evaluation in France seems at once promising and uncertain. Although the signs of development are evident‐increasing numbers of evaluations, aroused public and parliamentary interest, active administrative involvement‐the process is not uniform, codified, or generally rigorous. The administration itself is the chief initiator of evaluations, possessing the greatest resources, yet only in a small minority of instances are the ideal conditions of evaluation met. Strong political pressure would almost certainly be essential to move the government toward the institutionalization of an effective appraisal system.