bluuebunny/crossref_metadata_2025 huggingface dataset:
Fouling mechanisms of model polymeric substances
Authors: Negaresh E. , Le‐Clech P. , Chen V.
Published: August 2007

Extracellular polymeric substances (EPS) and soluble microbial products (SMP) have been identified as the main foulants in membrane bioreactor (MBR) operation. For a better understanding of the fouling mechanisms of these substances, filtration of model solutions with submerged membranes was carried out. Filtration was conducted following the flux‐stepping method. In this work alginate was used as a model for polysaccharide, bovine serum albumin (BSA) as a model for protein, and yeast (washed and unwashed) and bentonite were used for suspended solid contents. Fouling behaviours and rejection propensities were also assessed for one‐component and two‐component solutions and provided explanations for fouling mechanisms of carbohydrate and its interaction with protein and membrane in MBR systems. During the filtration of most foulants (except BSA), introducing the alginate increased the reversible fouling more than the irreversible one. In addition, a different behaviour was observed for the mixture of BSA and alginate. Fouling rate was also affected by the introduction of alginate. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
Incidental catch of marine turtles by Italian trawlers and longliners in the central Mediterranean
Authors: Casale Paolo , Cattarino Lorenzo , Freggi Daniela , Rocco Massimiliano , Argano Roberto
Published: August 2007

The fishing effort and turtle catch of vessels harbouring at Lampedusa island and fishing in the wider central Mediterranean area was monitored using a voluntary logbook programme. Two large trawlers were monitored between 2003 and 2005 and six small vessels using trawl nets, pelagic longline or bottom longline were monitored in the summer 2005.

The observed turtle catch rates of pelagic longline and bottom trawl were among the highest recorded in the basin, and high catch rates by bottom longline were observed too. This suggests that the area contains major oceanic and neritic habitats for the loggerhead turtle Caretta caretta in the Mediterranean Sea.

When fishing effort is considered, these results suggest a very high number of captures by Italian trawlers and longliners in the area, as well as by fleets from other countries. This is reason of concern for the conservation of the loggerhead turtle within the Mediterranean Sea.

Different fishing gear have different technical/operational characteristics affecting turtle catch and mortality and the present knowledge about associated parameters of these gear varies too.

All this considered, specific actions are recommended: (i) an awareness campaign to fishermen to reduce post‐release mortality, (ii) technical modifications to pelagic longline gear to reduce turtle catch, (iii) further investigation into turtle bycatch in all fishing gear, with priority given to bottom longline fishing and quantification of mortality caused by trawlers, (iv) assessment of the turtle populations affected by fishing activity in the area, and (v) international cooperation in undertaking threat assessments, and implementing regulations, management measures and monitoring.

Copyright © 2007 John Wiley & Sons, Ltd.
Asymmetric Hydrogenations One by One: Differentiation of up to Three β‐Ketocarboxylic Acid Derivatives Based on Ruthenium(II)–Binap Catalysis
Authors: Kramer Rainer , Brückner Reinhard
Published: August 2007

Noyori‐type reductions of pairs of β‐ketoamides and β‐ketoesters with elemental hydrogen (4 bar) proceeded substrate by substrate. When Et2NH2+[{RuCl(S)‐binap}2](μ‐Cl)3− was employed as a catalyst in a methanol or ethanol solution, the substrates were reduced at room temperature in the order β‐ketopyrrolidide ≥ β‐ketopiperidide ≥ β‐keto(N,N‐diethylamide) > β‐keto(alkyl esters) > β‐keto(oligofluoroalkyl esters). This is the first time that β‐ketoamides have been reduced asymmetrically (91 to >98 % ee) under such mild conditions. Monitoring the concentrations of these β‐ketocarboxyl acid derivatives and their respective hydrogenation products over the course of time showed that the most electron‐rich substrate is captured by the catalyst preferentially and exothermically; whether this occurs reversibly or irreversibly remains to be determined. The hydrogenation product is subsequently formed. The last transformation includes the rate‐determining step. The combination of these events explains why starting from appropriate mixtures of substrates a “first‐choice substrate” reacted from early on while the “second‐choice substrate” stayed virtually untouched over an extended period of time and reacted no earlier than after the “first‐choice substrate” had disappeared. From then onward, however, the “second‐choice substrate” also reacted relatively rapidly.
Synthesis of a Bis‐macrocycle Containing Two Back‐to‐Back Rigidly Connected 1,10‐Phenanthroline Units as a Central Core and its Incorporation in a Handcuff‐Like Catenane
Authors: Frey Julien , Kraus Tomáš , Heitz Valérie , Sauvage Jean‐Pierre
Published: August 2007

A bis‐macrocycle containing two back‐to‐back connected 1,10‐phenanthroline chelates has been prepared. The synthetic strategy involves the preparation of a monocyclic precursor consisting of a 1,10‐phenanthroline‐5,6‐dione fragment incorporated in a 30‐membered ring. This important intermediate has been prepared via two distinct routes, both strategies relying on the use of a ketal as a 1,2‐dione protective group. A four‐component condensation reaction between two molecules of the macrocyclic dione and two equivalents of ammonia (used in large excess) in the presence of a reducing agent (Na2S2O4) leads to the desired bis‐ring in good yield. The most direct synthetic route allows preparation of the bis‐macrocycle in seven steps from 1,10‐phenanthroline in an overall yield of 14 %. Using the now well‐established “gathering and threading” effect of copper(I), a doubly threaded species could be obtained in quantitative yield, in which each ring of the bis‐macrocycle is threaded by a “molecular string”. These fragments bear terminal allylic groups, which are used to prepare the final catenane by performing a double ring‐closing metathesis reaction. This final cyclisation reaction is high yielding and affords the desired catenane consisting of a bis‐macrocycle of which the two cyclic units are threaded by a large ring. The compound has been fully characterised by classical techniques. Electronic spectroscopy and electrochemical measurements suggest that the two copper complex subunits do not interact electronically, in spite of the aromatic nature of the bridging ligand between the two metal centres.
N‐Heterocyclic Carbenes of 5‐Haloindazoles Generated by Decarboxylation of 5‐Haloindazolium‐3‐carboxylates
Authors: Schmidt Andreas , Snovydovych Bohdan , Habeck Tobias , Dröttboom Petra , Gjikaj Mimoza , Adam Arnold
Published: August 2007

Syntheses and properties of 5‐fluoro‐, chloro‐ bromo‐, and iodo‐substituted 1,2‐dimethyl indazolium‐3‐carboxylates as new representatives of pseudo‐cross‐conjugated heterocyclic mesomeric betaines are described, and results of an X‐ray single crystal analysis of the nonhalogenated parent compound are presented. These betaines decarboxylate on heating to yield 5‐halo‐1,2‐dimethyl‐indazol‐3‐ylidenes, which can be trapped by protons, sulfur, and 2,4‐dichlorophenylisocyanate, respectively. The decarboxylation is studied by electrospray‐ionization mass spectrometry, NMR spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
(5‐Imino‐4,5‐dihydro‐3H‐pyrrol‐2‐yl)amines as Sterically Restrained 1,3,5‐Triazapenta‐1,3‐dienes: Useful Building Blocks for the Synthesis of Oligonitriles
Authors: Marihart Edgar A. , Greving Jan‐Bernd , Fröhlich Roland , Würthwein Ernst‐Ulrich
Published: August 2007

(5‐Imino‐4,5‐dihydro‐3H‐pyrrol‐2‐yl)amines 2 may be considered as sterically restrained 1,3,5‐triazapenta‐1,3‐dienes. They were easily prepared from 2,2,3,3‐tetramethylsuccinonitrile (1) and lithium amides with subsequent aqueous workup to give the monocyclic compounds 2a–d and the bi‐ and tricyclic compounds 2e–g. X‐ray diffraction studies of 2c and 2d, which contain a primary NH2 group, reveal the existence of homodimers held together with paired hydrogen bonds in the solid state. Trapping of the lithiated intermediate 2a‐Li by benzoyl chloride provided access to the 1‐oxa‐3,5,7‐triazahepta‐1,3,5‐triene 3b. It is characterized in the solid state by a planar heterocyclic subunit and a strongly twisted N‐acylamidine part. With 1‐oxa‐3,5‐diazinium salts 4, compounds 2a,b,d or 2a‐Li reacted to give 1‐oxa‐3,5,7,9,11‐pentaazaundeca‐1,3,5,7,9‐pentaenes 5a–d. Here again, the planar heterocyclic parts combine with longer, twisted (not helical) oligonitrile moieties. The X‐ray diffraction study of 5d indicates intermolecular N–H···O=C hydrogen bonding in the solid state, producing one‐dimensional strands. In a similar way as 1 the trinitrile 2,3,5‐trimethyl‐2,3,5‐tricyanohexane (6), a byproduct of the thermal decomposition of azoisobutyronitrile (AIBN), reacted with lithium benzylamide to give a bicyclic intermediate which was successfully converted into the corresponding 1‐oxa‐3,5,7,9,11,13‐hexaazatrideca‐1,3,5,7,9,11‐hexaene 7 when treated with 1‐oxa‐3,5‐diazinium salt 4b. Similar to 5d, this extended oligonitrile forms one‐dimensional hydrogen‐bonded polymers in the solid state. Its UV spectrum (λmax = 286 nm) is interpreted in terms of a planar conjugated π–π* azapolyene substructure forced into planarity by the heterocycles.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Fluorous Synthesis of Yuehchukene by α‐Lithiation of Perfluoroalkyl‐Tagged 1‐(Arylsulfonyl)indole with Mesityllithium
Authors: Naka Hiroshi , Akagi Yusuke , Yamada Kyoko , Imahori Tatsushi , Kasahara Takahiro , Kondo Yoshinori
Published: August 2007

Lithiation chemistry has not been well explored in fluorous synthesis because of the lack of appropriate base‐resistant fluorous tags; we recently developed a perfluoroalkylated arylsulfonyl tag for the protection of the indole ring nitrogen atom. Mesityllithium was found to be a suitable reagent for the α‐lithiation of perfluoroalkyl‐tagged 1‐(arylsulfonyl)indole, and the fluorous synthesis of yuehchukene was accomplished efficiently using this method as a key step. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Drug‐induced Myc‐mediated apoptosis of cancer cells is inhibited by stress protein Hsp70
Authors: Afanasyeva Elena A. , Komarova Elena Yu. , Larsson Lars‐Gunnar , Bahram Fuad , Margulis Boris A. , Guzhova Irina V.
Published: August 2007

The Myc oncoprotein serves a dual function by stimulating cells both towards growth and apoptosis. The latter functions are often abrogated during tumor development. The Hsp70 stress protein is a potent anti‐apoptotic molecule, but its potential role in protecting cells from Myc‐mediated apoptosis has not been investigated. Our results show that activated Myc potentiated apoptosis induced by the cancer drugs etoposide (ETO) and camptothecin (CAMP) in v‐Myc‐expressing human U‐937 monoblastic cells and in Rat1 cells containing a conditionally active Myc/estrogen receptor (MycER) fusion protein. However, both heat shock and ectopic Hsp70 expression protected the cells from Myc‐mediated apoptosis after drug treatment in both systems. The increased susceptibility to the anti‐tumor drugs by activated Myc was enhanced by siRNA‐mediated knockdown of Hsp70 expression in U‐937 cells. Addressing the mechanisms by which Myc and Hsp70 promotes and inhibits drug‐induced apoptosis, respectively, we found that v‐Myc stimulated cytochrome c release and activation of effector caspase‐9, ‐3 and ‐7, but not of initiator caspase‐8. Inhibition of caspase‐9 specifically reduced v‐Myc‐stimulated apoptosis, whereas inhibition of caspase‐8 and ‐3/7 reduced apoptosis both in v‐myc‐expressing and parental ETO‐treated U‐937 cells. Interestingly, Myc‐stimulated activation of effector caspases was inhibited, but cytochrome c release was not affected by Hsp70 expression, suggesting that Hsp70 interferes with the proapoptotic function of Myc downstream of mitochondria, at the level of caspase‐9 and downstream caspases. In conclusion, Hsp70 seems to have key function in inhibition of apoptosis mediated by Myc and may therefore play an important role in Myc‐driven oncogenesis. © 2007 Wiley‐Liss, Inc.
Model‐free evaluation of directional predictability in foreign exchange markets
Authors: Chung Jaehun , Hong Yongmiao
Published: August 2007

We examine directional predictability in foreign exchange markets using a model‐free statistical evaluation procedure. Based on a sample of foreign exchange spot rates and futures prices in six major currencies, we document strong evidence that the directions of foreign exchange returns are predictable not only by the past history of foreign exchange returns, but also the past history of interest rate differentials, suggesting that the latter can be a useful predictor of the directions of future foreign exchange rates. This evidence becomes stronger when the direction of larger changes is considered. We further document that despite the weak conditional mean dynamics of foreign exchange returns, directional predictability can be explained by strong dependence derived from higher‐order conditional moments such as the volatility, skewness and kurtosis of past foreign exchange returns. Moreover, the conditional mean dynamics of interest rate differentials contributes significantly to directional predictability. We also examine the co‐movements between two foreign exchange rates, particularly the co‐movements of joint large changes. There exists strong evidence that the directions of joint changes are predictable using past foreign exchange returns and interest rate differentials. Furthermore, both individual currency returns and interest rate differentials are also useful in predicting the directions of joint changes. Several sources can explain this directional predictability of joint changes, including the level and volatility of underlying currency returns. Copyright © 2007 John Wiley & Sons, Ltd.
A mechanistic view on the evolutionary origin for centrin‐based control of centriole duplication
Authors: Salisbury Jeffrey L.
Published: August 2007

Mounting evidence implicates the protein centrin as a key regulator of centriole duplication, yet it remains to be determined just how centrin functions in this process. Recent studies suggest that centrin exerts both spatial and temporal control over centriole duplication through its role as a component of centriole precursor structures and through periodic cell‐cycle specific changes in its abundance. Here, an overview of centrin and its role in centrosome dynamics is presented. Finally, a speculative model for just how centrin may operate to control centriole duplication is proposed with the intention to stimulate future advances in this area. This model provides an evolutionary basis for the preservation of essential features of the yeast spindle pole body (SPB) with the origin of the complex structure of the mammalian centriole. J. Cell. Physiol. 213: 420–428, 2007. © 2007 Wiley‐Liss, Inc.
Positional lumbar imaging using a positional device in a horizontally open‐configuration MR unit—Initial experience
Authors: Hayashida Yoshiko , Hirai Toshinori , Hiai Yasuhiro , Kitajima Mika , Imuta Masanori , Murakami Ryuji , Nakayama Yoshiharu , Awai Kazuo , Yamashita Yasuyuki , Takahashi Tetsuhiko , Hamada Kiyomi
Published: August 2007

Purpose

To evaluate whether positional MR images of the lumbar spine, obtained with a horizontally open‐configuration MR unit, demonstrate positional changes of the dural sac, and to assess whether there are significant differences in positional changes between healthy volunteers and patients with chronic low back pain.

Materials and Methods

The study population consisted of 15 patients with chronic low back pain and 14 healthy volunteers. MR images were obtained using a horizontally open‐configuration 0.4‐T MR unit. After conventional lumbar MR examinations, images were obtained in the flexion, neutral, and extension positions, using a positioning device. The anteroposterior diameter of the dural sac at the level of each lumbar disk was measured in the three positions and quantitative data were compared.

Results

Our MR protocol was tolerated by all patients. In both patients and volunteers, the mean anteroposterior diameter of the dural sac was smaller in the extension positions than in the flexion positions. In the mean rate of change (RC) in the dural sac diameter at the site of the degenerated disks, the difference between the volunteers and patients was significant (P < 0.05). There was no significant difference in the mean RC between patients and volunteers without degenerative disks.

Conclusion

Using a horizontally open‐configuration MR unit, positional MR imaging provided position‐dependent change of the dural sac. Positional changes at the site of the degenerated disks may be different in patients with and without chronic low back pain. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Low‐energy collision‐induced fragmentation of negative ions derived from ortho‐, meta‐, and para‐hydroxyphenyl carbaldehydes, ketones, and related compounds
Authors: Attygalle Athula B. , Ruzicka Josef , Varughese Deepu , Bialecki Jason B. , Jafri Sayed
Published: August 2007

Collision‐induced dissociation (CID) mass spectra of anions derived from several hydroxyphenyl carbaldehydes and ketones were recorded and mechanistically rationalized. For example, the spectrum of m/z 121 ion of deprotonated ortho‐hydroxybenzaldehyde shows an intense peak at m/z 93 for a loss of carbon monoxide attributable to an ortho‐effect mediated by a charge‐directed heterolytic fragmentation mechanism. In contrast, the m/z 121 ion derived from meta and para isomers undergoes a charge‐remote homolytic cleavage to eliminate an •H and form a distonic anion radical, which eventually loses CO to produce a peak at m/z 92. In fact, for the para isomer, this two‐step homolytic mechanism is the most dominant fragmentation pathway. The spectrum of the meta isomer on the other hand, shows two predominant peaks at m/z 92 and 93 representing both homolytic and heterolytic fragmentations, respectively. 18O‐isotope‐labeling studies confirmed that the oxygen in the CO molecule that is eliminated from the anion of meta‐hydroxybenzaldehyde originates from either the aldehydic or the phenolic group. In contrast, anions of ortho‐hydroxybenzaldehyde and 2‐hydroxy‐1‐naphthaldehyde, both of which show two consecutive CO eliminations, specifically lose the carbonyl oxygen first, followed by that of the phenolic group. Anions from 2‐hydroxyphenyl alkyl ketones lose a ketene by a hydrogen transfer predominantly from the α position. Interestingly, a very significant charge‐remote 1,4‐elimination of a H2 molecule was observed from the anion derived from 2,4‐dihydroxybenzaldehyde. For this mechanism to operate, a labile hydrogen atom should be available on the hydroxyl group adjacent to the carbaldehyde functionality. Copyright © 2007 John Wiley & Sons, Ltd.
Modeling of microwave devices with space mapping and radial basis functions
Authors: Koziel Slawomir , Bandler John W.
Published: August 2007

We review recent developments in space mapping techniques for modeling of microwave devices. We present a surrogate modeling methodology that utilizes space mapping combined with radial basis function interpolation. The method has advantages both over the standard space mapping modeling methodology and the recently published space mapping modeling with variable weight coefficients. In particular, it provides accuracy comparable or better than the latter method and computational efficiency as good as the standard space mapping modeling procedure. A comparison between the space mapping modeling methodologies as well as application examples of optimization and statistical analysis of microwave structures is presented. Copyright © 2007 John Wiley & Sons, Ltd.
Experimental design optimization of the capillary electrophoresis separation of leucine enkephalin and its immune complex
Authors: Babar Sheikh Md. Enayetul , Song Eun Joo , Hasan Md. Nabiul , Yoo Young Sook
Published: August 2007

To optimize the capillary electrophoretic separation conditions for leucine enkephalin (LE) and the immune complex of the LE and anti‐LE reaction, an analysis using a three‐level, three‐factorial Box–Behnken design was performed. Three separation parameters, buffer pH (X1), buffer concentration (X2), and applied voltage (X3), were chosen to observe the effect on separation responses. The responses were theoretical plate number, migration time of the LE peak, and resolution between the peaks. The optimum conditions and process validation were determined using statistical regression analysis and surface plot diagrams. The capillary electrophoresis optimum separation conditions were established to be 75 mM phosphate buffer at pH 7.00 with an applied separation voltage of 15 kV. By using the analysis technique, the prediction of responses was satisfactory and process verification yielded values within the ±5% range of the predicted efficiency.
Multidimensional gas chromatographic determination of naphthenes, paraffins, olefins, and aromatics in reformed gasolines
Authors: Lo Coco Filippo , Gasparini Gianni , Lanuzza Francesco
Published: August 2007

Increasing demand for gasoline, changing regulations concerning the reduction of environmental impact, and new refining technologies have led to the refinement of its composition. Nowadays, gasoline is a complex mixture of different fractions deriving from processes of reforming, cracking, isomerization, and alkylation, with the addition of both oxygenated compounds and butanes. There are regulations governing the mixing of various fractions and it is necessary to analyse the composition of these fractions to ensure that the final composition of commercial gasoline satisfies the required specifications. Moreover, analysis of the composition of each fraction enables the technological process of the fraction examined to be modified as appropriate. In this work some reformed gasolines were analysed by multidimensional gas chromatography. This technique allows good separation of the hydrocarbon types in a single analysis and gives the carbon number distribution within each hydrocarbon type.
Nano‐LC‐MS/MS for the monitoring of angiotensin IV in rat brain microdialysates: Limitations and possibilities
Authors: Lanckmans Katrien , Stragier Bart , Sarre Sophie , Smolders Ilse , Michotte Yvette
Published: August 2007

To broaden our knowledge about the central role of the angiotensin IV (Ang IV) peptide, we aimed to monitor its extracellular concentration in the brain using in vivo microdialysis. Ang IV was measured in the dialysates using a previously developed nano‐LC‐MS/MS assay with an LOD of 50 pM. Using this assay, baseline levels of Ang IV in dialysates from different brain structures were undetectable. However, immediately after microdialysis probe insertion, Ang IV could be detected in a concentration that varied between 120 and 187 pM. Using the zero‐net‐flux method, the extracellular levels of Ang IV in the striatum were estimated at 46 pM. These data may indicate that Ang IV is mainly present intracellularly. In addition, Ang IV was clearly measurable after striatal perfusion of Ang II. On the other hand, our nano‐LC‐MS/MS method was successful for the detection of Met‐enkephalin and neurotensin in dialysates from the rat. In conclusion, the nano‐LC‐MS/MS method coupled with microdialysis is well suited to monitor the biologically significant conversion between Ang II and Ang IV in vivo, but physiological extracellular levels of Ang IV appear too low to be detected.
Macromol. Chem. Phys. 16/2007
Authors: Kim Mi‐Jeong , Lee JaeDong , Chun Chaemin , Kim Dong‐Yu , Higuchi Seiji , Nakayama Tomonobu
Published: August 2007

Cover: Dynamics of laser‐induced alignment and surface grating formation of azobenzene polymer were examined in relation to the photoisomerization pathway of the excited states. Further details can be found in the Full Paper by M. J. Kim*, J. D. Lee, C. Chun, D. Y. Kim, S. Higuchi, and T. Nakayama on page 1753.
Spherical Polyelectrolyte Brushes as Carriers for Catalytically Active Metal Nanoparticles
Authors: Yu M. , Lu Y. , Schrinner M. , Polzer F. , Ballauff M.
Published: August 2007

Summary: We present a study on the catalytic activity of metal nanoparticles immobilized on spherical polyelectrolyte brushes that act as carriers. The spherical polyelectrolyte brushes consist of a solid core of poly(styrene) onto which long chains of poly(2‐methylpropenoyloxyethyl) trimethylammonium chloride are grafted. These positively charged chains form a dense layer of polyelectrolytes on the surface of the core particles (“spherical polyelectrolyte brush”) that tightly binds divalent metal ions, such as AuCl, PdCl or PtCl. The reduction of these ions within the brush layer leads to nearly monodisperse metal nanoparticles. Gold, platinum and palladium nanoparticles with diameters of around 1.25 nm, 2.1 nm and 2.4 nm have been embedded into polyelectrolyte brushes, respectively. The composite particles exhibit excellent colloidal stability. The catalytic activity is investigated by photometrically monitoring the reduction of p‐nitrophenol by an excess of NaBH4 in the presence of the nanoparticles. The kinetic data could be explained by the assumption of a pseudo‐first‐order reaction with regard to p‐nitrophenol. All data demonstrate that spherical polyelectrolyte brushes present an ideal carrier system for metallic nanoparticles.
Structure and Dynamics of Angiotensin (1‐7) Vasoactive Peptide in Aqueous Solution at the Density‐Functional Based Tight‐Binding Level
Authors: de Lima Guilherme Ferreira , Heine Thomas , Duarte Hélio A.
Published: August 2007

Summary: Structure and dynamics of heptapeptide Angiotensin (1‐7) in aqueous solution have been investigated by means of density‐functional based tight‐binding molecular dynamics simulations. Solvent‐solute interactions have been studied using a hybrid QM/MM method. The backbone of the heptapeptide remains relatively rigid in aqueous solution compared to gas phase. The solvent acts as a cushion, preventing the free motion of the molecule. Tyrosine is the residue which presents the smallest flexibility and the largest number of water molecules in its first solvation shell. This is in good agreement with the previously published NMR results. The intra– and intermolecular hydrogen bridges have been quantified and analyzed in terms of conformation and stability.
Preparation, Characterization and Applications of Electron‐Beam Curing‐Derived Monolithic Materials
Authors: Bandari Rajendar , Knolle Wolfgang , Buchmeiser Michael R.
Published: August 2007

Summary: Acrylate/methacrylate‐based monoliths have been prepared via electron‐ beam (EB) initiated polymerization. These monolithic columns were found suitable for application in the analytical scale separation of various analytes such as proteins. Functionalization of the monolithic columns was accomplished via copolymerization of functional monomers. Selected examples of both synthesis and application will be summarized.
Novel Surface‐Active Succinate Monomers and Initiators for Obtaining Reactive Polymers
Authors: Hevus Ivan , Pikh Zorian
Published: August 2007

Summary: Novel surface‐active monomers and initiators were synthesized by successive treatment of cumylsuccinic anhydride with 3‐tert‐butylperoxy‐3‐methyl‐1‐ butanol or poly(propylene glycol) acrylate and 1,3‐propane sultone with triethylamine. The surface tension isotherms on the air‐water solution interface were obtained. The critical micelle concentrations (cmc) as well as the surface tension at the cmc were determined for these substances. The complex thermal analysis of the obtained inisurf was carried out and the possible mechanism of decomposition of its peroxide group was proposed. The synthesized compounds were shown to be suitable reactive surfactants for obtaining styrene latexes.
Synthesis and Characterization of New Functional Poly(ester‐anhydride)s Based on Succinic and Sebacic Acids
Authors: Jaszcz Katarzyna
Published: August 2007

Summary: New functional poly(ester‐anhydride)s with allyl pendant groups in the side chains were obtained by polycondensation of sebacic acid (SBA) and poly(3‐allyloxy‐1,2‐propylene succinate) (OSAGE) terminated with carboxyl groups. The carboxyl groups in OSAGE and in SBA were converted to mixed anhydride groups by acetylation with acetic anhydride. After that, prepolymers obtained were condensed in vacuum to yield higher molecular weight poly(ester‐anhydride)s. The influence of SBA and OSAGE content in poly(ester‐anhydride)s on their selected properties e.g. molecular weight, thermal and solubility characteristics as well as degradation rate and mode, were examined. Poly(ester‐anhydride)s were degraded in aqueous buffer of pH 7.4 at 37 °C. The hydrolytic degradation was monitored by determination of weight loss of samples and by determination of ester to anhydride groups ratio.
A Study on the Vinyl Acetate‐co‐Butyl Acrylate Latexes in the Presence of N‐Methylol Acrylamide and Mixed Type Emulsifiers
Authors: Kahraman Ayca , Sarac Ayfer
Published: August 2007

Summary: The properties of copolymer latexes depend on the copolymer composition, polymer morphology, initiator, polymerization medium and colloidal characteristics of copolymer particles. Poly(vinyl acetate‐co‐butyl acrylate) latexes with N‐metylol acrylamide were prepared by applying semicontinuous emulsion polymerization. The systems studied were (a) the mixture of anionic sodium lauryl sulfate ether (SELES) with nonionic 30 moles ethoxylated nonyl phenol (NP 30) (50:50), (b) the mixture of anionic sodium lauryl sulfate ether (SELES) with nonionic 30 moles ethoxylated nonyl phenol (NP 30) (70:30), and (c) anionic sodium lauryl sulfate ether (SELES) (100%). The effects of the emulsifier and emulsifier composition on the physicochemical properties of obtained vinyl acetate‐co‐butyl acrylate latex properties in the presence of N‐methylol acrylamide initiated by ammonium persulfate were investigated.
Reactive Blends of Poly(phenylene sulfide)/Hyperbranched Poly(phenylene sulfide)
Authors: Bo Yan , Long Chen , Meifang Zhu , Yanmo Chen
Published: August 2007

Summary: Polymer blends consisting of linear poly(phenylene sulfide) (PPS) and hyperbranched PPS (HPPS) were obtained in melt. The solid‐state properties of PPS and their blends were investigated by scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), extraction measurement, differential scanning calorimetry (DSC) and dynamical mechanical analysis (DMA). Blends prepared by melt mixing turned out to be reactive as shown by the TGA and extraction measurement. SEM indicated that no phase separation occurs in PPS/HPPS blends. The degree of crystallization of the blends decreased with increasing HPPS content. Both the storage modulus and loss modulus increased as HPPS content increasing.
Thin Coatings with Photo‐Catalytic Activity Based on Inorganic‐Organic Hybrid Polymers Modified with Anatase Nanoparticles
Authors: Textor Torsten , Schroter Frank , Schollmeyer Eckhard
Published: August 2007

Summary: Inorganic‐organic hybrid polymer sols where modified with differently prepared as well as commercial titania nanoparticles, to obtain coatings exhibiting a photo‐catalytic activity for the development of self‐cleaning textiles. The particles synthesized using a sol‐gel‐approach where, amongst others, investigated by XRD to prove the existence of titania crystallized in the anatase structure. The photo‐catalytic activity of the different particles as well of the coatings was compared by the decomposition of astrazone red induced by an irradiation with artificial and solar UV‐radiation. With respect to the underlying aim of the investigation the durability of the effect against washing was tested by standardized washing experiments, showing promising results.
Reactive Compatibilization of Polyethylene/Ground Tire Rubber Inhomogeneous Blends via Interactions of Pre‐Functionalized Polymers in Interface
Authors: Tolstov Alexander , Grigoryeva Olga , Fainleib Alexander , Danilenko Inna , Spanoudaki Anna , Pissis Policarpos , Grenet Jean
Published: August 2007

Summary: Reactive compatibilization of recycled low‐ or high‐density polyethylenes (LDPE and HDPE, respectively) and ground tire rubber (GTR) via chemical interactions of pre‐functionalized components in their blend interface has been carried out. Polyethylene component was functionalized with maleic anhydride (MAH) as well as the rubber component was modified via functionalization with MAH or acrylamide (AAm) using chemically or irradiation (γ‐rays) induced grafting techniques. The grafting degree and molecular mass distribution of the functionalized polymers have been measured via FTIR and Size Exclusion Chromatography (SEC) analyses, respectively. Thermoplastic elastomer (TPE) materials based on synthesized reactive polyethylenes and GTR as well as ethylene‐propylene‐diene rubber, EPDM were prepared by dynamic vulcanization of the rubber phase inside thermoplastic (polyethylene) matrix and their phase structure, and main properties have been studied using DSC and mechanical testing. As a final result, the high performance TPE with improved mechanical properties have been developed.
Effect of Specific Interactions on Structure‐Property Relationships of Thermoplastic IPNs Based on Polyurethane and Styrene‐co‐Acrylic Acid Ionomers
Authors: Grigoryeva Olga , Slisenko Olga , Bismarck Alexander , Sergeeva Lyudmila
Published: August 2007

Summary: The structure‐property relationships of thermoplastic polymer blends based on poly(ether‐urethane) ionomer (PEUI) and K+‐Ion containing styrene‐acrylic acid random copolymer (S‐co‐AA(K)) have been investigated by different methods. Convergence of the glass transition temperature values of the PEUI and the S‐co‐AA(K) components in the blends studied and improvement of end‐use properties have been found.
ABS‐Modified Epoxy Resins – Curing Kinetics, Polymerization Induced Phase Separation, and Resulting Morphologies
Authors: Müller Yvonne , Häußler Liane , Pionteck Jürgen
Published: August 2007

Summary: A commercial diglycidylether of bisphenol A (DGEBA) was modified with an acrylonitrile‐butadiene‐styrene‐copolymer (ABS) and cured with the diamine hardener 4,4′‐diaminodiphenylsulfone (DDS). The curing kinetics was followed by DSC‐ and PVT‐measurements. The polymerization induced phase separation (PIPS) was studied using light microscopy and electron microscopy. While the cloud point analyzed by light microscopy is independent of the ABS content, the curing is accelerated by the presence of ABS. The non‐linear dependency of the curing rate on the ABS content must have its origin in the different morphologies developed due to PIPS.
Synthesis of Specially Designed Adhesion Promoter for Grafting Polypyrrole
Authors: Oberoi Sonia , Jaehne Evelin , Adler Hans‐Jurgen P.
Published: August 2007

Summary: Adhesion of conducting polymers to the metal/metal oxide surfaces is not strong. An attempt was made to modify these reactive metal surfaces by N‐derivatised pyrroles. ω‐(pyrrol‐1‐yl alkyl) phosphonic acids with different chain lengths were successfully synthesized and characterized. These derivatives were studied for their adsorption and self‐assembling phenomena onto Ti/TiO2, Ta/Ta2O5 and Al/Al2O3. Various analytical tools were used to characterize the modified surface. Contact angle measurements indicated an increase in hydrophobicity after adsorption that was further confirmed by Surface Plasmon Resonance (SPR). X‐ray Photoelectron Spectroscopy (XPS) studies showed that the molecules are oriented in a fashion such that phosphonic acid group is attached to the metal surface and pyrrole is pointing away from the surface. The oxidation potential of these derivatives was higher than pyrrole as expected. Surface polymerisation was successfully attempted on the modified metal substrates. The polymerised surface was examined under Scanning Electron Microscope (SEM). The new compounds not only function as self‐assembling molecules, they also exhibit a new class of reactive functionalized derivatives that can be used as monomers for polymerisation.
Side‐Chain Sulfonated Poly(arylene ether)s for Fuel Cell Applications
Authors: Meier‐Haack J. , Komber H. , Vogel C. , Butwilowski W. , Schlenstedt K. , Lehmann D.
Published: August 2007

Summary: Poly(arylene ether sulfone)s of high molecular weight and narrow molecular weight distribution were obtained by melt polycondensation of 4,4′‐difluorodiphenyl‐ sulfone and trimethylsilylethers of 4,4′‐dihydroxydiphenylsulfone and phenylhydroquinone using CsF as catalyst. Although a block‐like structure of the polymers could be expected from the course of reaction, only a single Tg ranging from 190 °C to 230 °C could be detected by DSC and which depended on the copolymer composition. Contrary to the sulfonation of similar poly(ether ether ketone)s the poly(arylene ether sulfone)s here reported were sulfonated both in the side chain and the main chain. Nonetheless the sulfonated poly(arylene ether sulfone)s showed high hydrolytic stability in water at 130 °C.
Peculiarities of the RuIV‐Alkylidene Triggered Cyclopolymerization of N‐(bis(alkyloxy)aryl)‐ Containing 1,6‐Heptadiynes
Authors: Schmidt Christian , Buchmeiser Michael R.
Published: August 2007

Summary: Some peculiarities in the cyclopolymerization of 1,6‐heptadiynes containing an amine‐nitrogen at the 4‐position are presented and discussed within the context of cyclopolymerization of N‐free 1,6‐heptadiynes.
Investigation of Gelling Aqueous Clay Dispersions with Dynamic Light Scattering
Authors: Ferse Bernhard , Richter Sven , Arndt Karl‐Friedrich , Richter Andreas
Published: August 2007

Summary:The gelation process of aqueous clay (Laponite XLS, XLG) dispersions and of a photopolymerization system (N‐isopropylacrylamide, Irgacure 2959, Laponite XLS) have been investigated by dynamic light scattering. The gelation threshold could be clearly indicated by a change in the shape of the time‐intensity correlation function.
Self‐Supporting Polymer Films for MEMS Applications
Authors: Nocke Andreas , Wolf Marcus , Budzier Helmut , Monch Jens , Arndt Karl‐Friedrich , Gerlach Gerald
Published: August 2007

Summary: The fabrication of a self supporting novolac‐based photoresist layer is demonstrated. A technology is presented using a sacrificial layer of PMMA and a carrier layer of photosensitive PI. The solely use of polymers for the creation of a self‐supporting structure is distinguished by simple processing and relatively low cost materials. Additionally the mechanical stability of the self‐supporting layer is under consideration. Finally the cross‐linking process of the novolac‐based photoresist by curing is discussed using FTIR, DSC and TGA measurements.
Development of anaplastic lymphoma kinase (ALK) small‐molecule inhibitors for cancer therapy
Authors: Li Rongshi , Morris Stephan W.
Published: August 2007

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK) involved in the genesis of several human cancers; indeed, ALK was initially identified in constitutively activated and oncogenic fusion forms—the most common being nucleophosmin (NPM)‐ALK—in a non‐Hodgkin's lymphoma (NHL) known as anaplastic large‐cell lymphoma (ALCL) and subsequent studies identified ALK fusions in the human sarcomas called inflammatory myofibroblastic tumors (IMTs). In addition, two recent reports have suggested that the ALK fusion, TPM4‐ALK, may be involved in the genesis of a subset of esophageal squamous cell carcinomas. While the cause‐effect relationship between ALK fusions and malignancies such as ALCL and IMT is very well established, more circumstantial links implicate the involvement of the full‐length, normal ALK receptor in the genesis of additional malignancies including glioblastoma, neuroblastoma, breast cancer, and others; in these instances, ALK is believed to foster tumorigenesis following activation by autocrine and/or paracrine growth loops involving the reported ALK ligands, pleiotrophin (PTN) and midkine (MK). There are no currently available ALK small‐molecule inhibitors approved for clinical cancer therapy; however, recognition of the variety of malignancies in which ALK may play a causative role has recently begun to prompt developmental efforts in this area. This review provides a succinct summary of normal ALK biology, the confirmed and putative roles of ALK fusions and the full‐length ALK receptor in the development of human cancers, and efforts to target ALK using small‐molecule kinase inhibitors. © 2007 Wiley Periodicals, Inc. Med Res Rev, 28, No. 3, 372–412, 2008
Radioactivity measurements and radiation dose evaluation in tap waters of Central Italy
Authors: Desideri Donatella , Roselli Carla , Assunta Meli Maria , Feduzi Laura , Rongoni Alba , Saetta Daniela
Published: August 2007

Consumption of drinking water is very important for human nutrition and its quality must be strictly controlled. A study of radioactivity content in tap water samples collected in the Central Italy was performed in order to check the compliance with recent European regulations. Gross alpha and beta activity, 226Ra, 238U and 234U concentrations were measured. Gross alpha and beta activities were determined by standard ISO 9696 and ISO 9697; for 226Ra determination liquid scintillation was used. 238U and 234U concentrations were determined by alpha spectrometry after separation from matrix by extraction chromatography and electroplating. Recommended WHO guideline activity concentrations for drinking water (0.1 and 1.0 Bq/L for gross alpha and gross beta activity, respectively) are exceeded in two cases for gross alpha activity and are not exceeded in any case for gross beta activity. The concentrations (mBq/L) of 226Ra, 238U and 234U ranged from < 1.70 to 15.3, 0.65 to 48.8 and 0.780 to 51.5, respectively. Effective dose due to the uranium isotopes and radium was calculated for children and adults using the dose coefficients reported by EC Directive 96/29 EURATOM and annual water intake. For all class ages, the doses are quite similar and much lower than 0.1 mSv/year.
Initiation of petroleum formation and antioxidant function – a DFT study of sulfursulfur bond dissociation enthalpies
Authors: Zou Lu‐Feng , Shen Kuang , Fu Yao , Guo Qing‐Xiang
Published: August 2007

Experimental studies showed that sulfur radicals play the vital role in petroleum formation.1 Sulfur‐ centered radicals also exhibit activities in antioxidant functions. Here we conduct a theoretical investigation of their precursor‐disulfides. By investigation into substituent effect on sulfursulfur bond dissociation enthalpies (SS BDEs), we would like to find the most effective provider for sulfur radicals. In the present work, 50 alpha‐substituted disulfides and 16 para‐substituted aryl disulfides are studied systematically, with the general formula XS‐SX or HS‐SX. The substituent effect on SS BDEs is found to be very eminent, ranging from 33.2 to 75.0 kcal/mol for alpha‐substituted disulfide, and from 43.7 to 59.7 kcal/mol for para‐substituted phenyl disulfides. We also evaluate the performance of 44 density functional methods to get an accurate prediction. A further study indicates that substituents play a major role in radical energies, instead of molecule energies, which is substantiated by the good linearity between XS‐SX bond dissociation enthalpy (BDE) and HS‐SX BDE. Copyright © 2007 John Wiley & Sons, Ltd.
Plasma Process. Polym. 6/2007
Authors: Yuan Luqi , Zhong Xiaoxia , Levchenko Igor , Xia Yuxing , Ostrikov Kostya
Published: August 2007

Cover: This picture presents a scheme of Au quantum dot growth through nano‐porous template by the i‐PVD process (left) and two scenarios of quantum dots growth in the nanopore (right). Control of electron temperature, substrate bias, and structure of nano‐porous template allows effective controlling the ion flux distribution in the nanopore. Further details can be found in the article by L. Yuan, X. Zhong,* I. Levchenko, Y. Xia, and K. Ostrikov* on page 612.
In vivo secretome sampling technology for proteomics
Authors: Huang Chun‐Ming
Published: August 2007

Secretome is a critical mediator for cell–cell and microbe–cell interaction. Identification of secretome will endow researchers with important biomarkers and therapeutic targets as well as reinforce the current methods used in the systems biology research of cell–cell interactions. Here, we introduce an in vivo sampling technique using capillary ultrafiltration (CUF) probes that are capable of continuously collecting pure in vivo secretome from tissue microenvironments. Great benefits of CUF probes when compared with other current sampling techniques have been acknowledged. CUF probes can be designed to fit various in vivo models and they are easily adapted to different protein‐detection systems including mass spectrometers. The future challenges and clinical advantages of CUF probe sampling are also highlighted in this review. Many prospective properties such as simple manipulation, dynamic sampling, pathogen clearance, online mass spectrometric coupling, and disease treatment and monitoring have made CUF probes attractive for clinical uses in the near future.
Proteomics in clinical prostate research
Authors: Hellström Magnus , Jonmarker Sara , Lehtiö Janne , Auer Gert , Egevad Lars
Published: August 2007

The incidence of early prostate cancer (PCa) has increased rapidly in recent years. The majority of newly diagnosed PCa are in early tumor phase. Presently, we do not have adequate biomarkers to assess tumor aggressiveness in individual cases. Consequently, too many patients are given curatively intended treatment. An exploration of the human proteome may provide clinically useful markers. 2‐DE has been successfully used for analysis of the protein phenotype using clinical samples. Proteins are separated according to size and charge, gels are compared by image analysis, protein spots of interest are excised, and proteins identified by MS. This method is exploratory and allows protein identification. However, low‐abundance proteins are difficult to detect and 2‐DE is currently too labor‐intensive for routine use. In recent years, nongel based techniques, such as LC‐MS, SELDI‐MS, and protein arrays have emerged. They require smaller sample sizes and can be more automated than 2‐DE. In this review, we describe studies of the protein expression of benign prostatic tissue and PCa, which is likely to serve as the first step in prognostic biomarker discovery. The prostate proteome is still far from a complete mapping which would enhance our understanding of PCa biology.