bluuebunny/crossref_metadata_2025 huggingface dataset:
First‐principle calculations on CO oxidation catalyzed by a gold nanoparticle
Authors: Chen Hsin‐Tsung , Chang Jee‐Gong , Ju Shin‐Pon , Chen Hui‐Lung
Published: May 2009

We have elucidated the mechanism of CO oxidation catalyzed by gold nanoparticles through first‐principle density‐functional theory (DFT) calculations. Calculations on selected model show that the low‐coordinated Au atoms of the Au29 nanoparticle carry slightly negative charges, which enhance the O2 binding energy compared with the corresponding bulk surfaces. Two reaction pathways of the CO oxidation were considered: the Eley–Rideal (ER) and Langmuir–Hinshelwood (LH). The overall LH reaction O2(ads) + CO(gas) → O2(ads) + CO(ads) → OOCO(ads) → O(ads) + CO2(gas) is calculated to be exothermic by 3.72 eV; the potential energies of the two transition states (TSLH1 and TSLH2) are smaller than the reactants, indicating that no net activation energy is required for this process. The CO oxidation via ER reaction Au29 + O2(gas) + CO(gas) → Au29–O2(ads) + CO(gas) → Au29–CO3(ads) → Au29–O(ads) + CO2(gas) requires an overall activation barrier of 0.19 eV, and the formation of Au29–CO3(ads) intermediate possesses high exothermicity of 4.33 eV, indicating that this process may compete with the LH mechanism. Thereafter, a second CO molecule can react with the remaining O atom via the ER mechanism with a very small barrier (0.03 eV). Our calculations suggest that the CO oxidation catalyzed by the Au29 nanoparticle is likely to occur at or even below room temperature. To gain insights into high‐catalytic activity of the gold nanoparticles, the interaction nature between adsorbate and substrate is also analyzed by the detailed electronic analysis. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Neuron‐specific RNA interference using lentiviral vectors
Authors: Nielsen Troels Tolstrup , Marion Ingrid van , Hasholt Lis , Lundberg Cecilia
Published: May 2009

Background

Viral vectors have been used in several different settings for the delivery of small hairpin (sh) RNAs. However, most vectors have utilized ubiquitously‐expressing polymerase (pol) III promoters to drive expression of the hairpin as a result of the strict requirement for precise transcriptional initiation and termination. Recently, pol II promoters have been used to construct vectors for RNA interference (RNAi). By embedding the shRNA into a micro RNA‐context (miRNA) the endogenous miRNA processing machinery is exploited to achieve the mature synthetic miRNA (smiRNA), thereby expanding the possible promoter choices and eventually allowing cell type specific down‐regulation of target genes.

Methods

In the present study, we constructed lentiviral vectors expressing smiRNAs under the control of pol II promoters to knockdown gene expression in cell culture and in the brain.

Results

We demonstrate robust knockdown of green fluorescent protein using lentiviral vectors driving RNAi from the ubiquitously‐expressing promoter of the cytomegalovirus (CMV) and, in addition, we show for the first time neuron‐specific knockdown in the brain using a neuron‐specific promoter. Furthermore, we show that the expression pattern of the presumed ubiquitously‐expressing CMV promoter changes over time from being expressed initially in neurons and glial cells to being expressed almost exclusively in neurons in later stages.

Conclusions

In the present study, we developed vectors for cell‐specific RNAi for use in the brain. This offers the possibility of specifically targeting RNAi to a subset of cells in a complex tissue and may prove to be of great importance in the design of future gene therapeutic paradigms. Copyright © 2009 John Wiley & Sons, Ltd.
Redirecting lentiviral vectors by insertion of integrin‐tageting peptides into envelope proteins
Authors: Morizono Kouki , Pariente Nonia , Xie Yiming , Chen Irvin S. Y.
Published: May 2009

Background

Targeting gene therapy vectors that can home in on desired cell and tissue types in vivo comprise the ultimate gene delivery system. We have previously developed targeting lentiviral vectors by pseudotyping vectors with modified Sindbis virus envelope proteins. The envelope protein contains the Fc‐binding region of protein A (ZZ domain), so the virus can be conjugated with antibodies. The conjugated antibody mediates specific transduction of the cells and tissues expressing the target antigens, both in vitro and in vivo. However, more stable conjugation of targeting molecules would be optimal for use in immunocompetent animals, as well as in humans.

Methods

We inserted integrin‐targeting peptides into two sites of the targeting envelope proteins and determined whether the peptides serve as receptor‐binding regions of the envelope proteins and redirect the pseudotyped viruses.

Results

The integrin‐targeting peptides can mediate binding to cells via the interaction with integrins on target cells and transduction. Peptides with a higher binding affinity increase titers of pseudotyped virus. We found two regions on the envelope protein that can accommodate insertion and serve as receptor‐binding regions. Combining the peptides in two distinct regions increased the titers of the virus.

Conclusions

Successful incorporation of targeting molecules into the envelope protein will broaden the application of targeting vectors for a wide variety of experimental and clinical settings. Copyright © 2009 John Wiley & Sons, Ltd.
Hepatic insulin gene therapy diminishes liver glycogen despite insulin responsive transcriptional effects in diabetic CD‐1 mice
Authors: Zhang Jin‐an , Jia Dingwu , Olson Darin E. , Campbell Adam G. , Thulé Peter M.
Published: May 2009

Background

Hepatic insulin gene therapy (HIGT) produces near‐normal glycemia in diabetic rats. Hepatic insulin production is expected to stimulate glycogen storage. However, the effect of HIGT on hepatic glycogen metabolism in vivo is unknown.

Methods

After administration of an adenoviral vector capable of inducing glucose responsive insulin production from hepatocytes, we evaluated circulating hormones, cytokines, hepatic gene expression and hepatic glycogen content in diabetic CD‐1 mice receiving intravenous streptozotocin. Nondiabetic mice and diabetic mice treated with empty adenovirus served as controls.

Results

Peripheral concentrations of human insulin in HIGT mice were less than concentrations of mouse insulin among controls. However, expression of insulin responsive genes in HIGT livers indicated a significant intra‐hepatic insulin effect, with expression changes reflecting appropriate responses to fed‐fasting transitions. Transcription factors (hepatocyte nuclear factor‐4α and peroxisome proliferator‐activated receptor γ co‐activator‐1α), as well as target genes (phospho‐enol‐pyruvate carboxykinase, glucose‐6‐phosphatase and glucokinase) exhibited insulin responsive expression. Despite producing near normal glycemia, HIGT diminished hepatic glycogen content in both fasted and fed mice. Serum cytokine responses revealed both vector‐related (monocyte chemoatractant protein‐1, interleukin‐6) and transgene specific (resistin, tumor necrosis factor α) effects.

Conclusions

HIGT produces low circulating concentrations of insulin, but produces significant intra‐hepatic effects on gene expression. Despite controlling hyperglycemia, HIGT exerts unexpected insulin effects on hepatic carbohydrate metabolism. Although the precise mechanisms remain to be determined, they may relate to vector‐induced cytokine effects. Copyright © 2009 John Wiley & Sons, Ltd.
AAV gene therapy as a means to increase apolipoprotein (Apo) A‐I and high‐density lipoprotein‐cholesterol levels: correction of murine ApoA‐I deficiency
Authors: Vaessen Stefan F. C. , Veldman Robert Jan , Comijn Elisabeth M. , Snapper Jolanda , Sierts Jeroen A. , van den Oever Karin , Beattie Stuart G. , Twisk Jaap , Kuivenhoven Jan Albert
Published: May 2009

Background

Inherited apolipoprotein (Apo) A‐I deficiency is an orphan disorder characterized by high‐density lipoprotein (HDL)‐cholesterol deficiency and premature atherosclerosis. Constitutive over‐expression of ApoA‐I might provide a means to treat this disease. The present study provides a comprehensive evaluation of adeno‐associated virus (AAV)‐mediated ApoA‐I gene delivery to express human (h)ApoA‐I and correct the low HDL‐cholesterol phenotype associated with ApoA‐I deficiency.

Methods

In an effort to maximize AAV‐mediated gene expression, we performed head‐to‐head comparisons of recombinant AAVs with pseudotype capsids 1, 2, 6 and 8 administered by different routes with the use of five different liver‐specific promoters in addition to cytomegalovirus as single‐stranded or as self‐complementary (sc) AAV vectors.

Results

Intravenous administration of 1 × 1013 gc/kg scAAV8, in combination with the liver‐specific promoter LP1, in female ApoA‐I−/− mice resulted in hApoA‐I expression levels of 634 ± 69 mg/l, which persisted for the duration of the study (15 weeks). This treatment resulted in full recovery of HDL‐cholesterol levels with correction of HDL particle size and apolipoprotein composition. In addition, we observed increased adrenal cholesterol content and a significant increase in bodyweight in treated mice.

Conclusions

The present study demonstrates that systemic delivery of a scAAV8 vector provides a means for efficient liver expression of hApoA‐I, thereby correcting the lipid abnormalities associated with murine ApoA‐I deficiency. Importantly, the study demonstrates that AAV‐based gene therapy can be used to express therapeutic proteins at a high level for a prolonged period of time and, as such, provides a basis for further development of this strategy to treat hApoA‐I deficiency. Copyright © 2009 John Wiley & Sons, Ltd.
Reconstructing trees from two cards
Authors: Welhan Manuel
Published: May 2009

Let 𝒯 be the class of unlabeled trees. An unlabeled vertex‐deleted subgraph of a tree T is called a card. A collection of cards is called a deck. We say that the tree T has a deck D if each card in D can be obtained by deleting distinct vertices of T. If T is the only unlabeled tree that has the deck D, we say that T is 𝒯‐reconstructible from D. We want to know how large of a deck D is necessary for T to be 𝒯‐reconstructible. We define 𝒯rn(T) as the minimum number of cards in a deck D such that T is 𝒯‐reconstructible from D. It is known that
𝒯rn(T)≤3, but it is conjectured that 𝒯rn(T)≤2 for all trees T. We prove that the conjecture holds for all homeomorphically irreducible trees. © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 243–257, 2010
Kings in locally semicomplete digraphs
Authors: Wang Ruixia , Yang Aimin , Wang Shiying
Published: May 2009

A k‐king in a digraph D is a vertex which can reach every other vertex by a directed path of length at most k. We consider k‐kings in locally semicomplete digraphs and mainly prove that all strong locally semicomplete digraphs which are not round decomposable contain a 2‐king. © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 279–287, 2010
Monochromatic Hamiltonian 3‐tight Berge cycles in 2‐colored 4‐uniform hypergraphs
Authors: Gyárfás András , Sárközy Gábor N. , Szemerédi Endre
Published: May 2009

Here improving on our earlier results, we prove that there exists an n0 such that for n⩾n0 in every 2‐coloring of the edges of K there is a monochromatic Hamiltonian 3‐tight Berge cycle. This proves the c=2, t=3, r=4 special case of a conjecture from (P. Dorbec, S. Gravier, and G. N. Sárközy, J Graph Theory 59 (2008), 34–44). © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 288–299, 2010
Multi‐coloring the Mycielskian of graphs
Authors: Lin Wensong , Liu Daphne Der‐Fen , Zhu Xuding
Published: May 2009

A k‐fold coloring of a graph is a function that assigns to each vertex a set of k colors, so that the color sets assigned to adjacent vertices are disjoint. The kth chromatic number of a graph G, denoted by χk(G), is the minimum total number of colors used in a k‐fold coloring of G. Let µ(G) denote the Mycielskian of G. For any positive integer k, it holds that χk(G) + 1≤χk(µ(G))≤χk(G) + k (W. Lin, Disc. Math., 308 (2008), 3565–3573). Although both bounds are attainable, it was proved in (Z. Pan, X. Zhu, Multiple coloring of cone graphs, manuscript, 2006) that if k≥2 and χk(G)≤3k−2, then the upper bound can be reduced by 1, i.e., χk(µ(G))≤χk(G) + k−1. We conjecture that for any n≥3k−1, there is a graph G with χk(G)=n and χk(µ(G))=n+ k. This is equivalent to conjecturing that the equality χk(µ(K(n, k)))=n+k holds for Kneser graphs K(n, k) with n≥3k−1. We confirm this conjecture for k=2, 3, or when n is a multiple of k or n≥3k2/ln k. Moreover, we determine the values of χk(µ(C2q+1)) for 1≤k≤q. © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 311–323, 2010
Deformation of nasal septal cartilage during mastication
Authors: Al Dayeh Ayman A. , Rafferty Katherine L. , Egbert Mark , Herring Susan W.
Published: May 2009

The cartilaginous nasal septum plays a major role in structural integrity and growth of the face, but its internal location has made physiologic study difficult. By surgically implanting transducers in 10 miniature pigs (Sus scrofa), we recorded in vivo strains generated in the nasal septum during mastication and masseter stimulation. The goals were (1) to determine whether the cartilage should be considered as a vertical strut supporting the nasal cavity and preventing its collapse, or as a damper of stresses generated during mastication and (2) to shed light on the overall pattern of snout deformation during mastication. Strains were recorded simultaneously at the septo‐ethmoid junction and nasofrontal suture during mastication. A third location in the anterior part of the cartilage was added during masseter stimulation and manipulation. Contraction of jaw closing muscles during mastication was accompanied by anteroposterior compressive strains (around −1,000 με) in the septo‐ethmoid junction. Both the orientation and the magnitude of the strain suggest that the septum does not act as a vertical strut but may act in absorbing loads generated during mastication. The results from masseter stimulation and manipulation further suggest that the masticatory strain pattern arises from a combination of dorsal bending and/or shearing and anteroposterior compression of the snout. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Morphology of skin incubation in Pipa carvalhoi (Anura: Pipidae)
Authors: Greven Hartmut , Richter Susanne
Published: May 2009

South American Pipidae show a unique reproductive mode, in which the fertilized eggs develop in temporarily formed brood chambers of the dorsal skin after eggs have been deposited on the back of the female. We studied the skin incubation of Pipa carvalhoi using light microscopy and scanning electron microscopy. The skin consists of a stratified epithelium with a one‐layered stratum corneum, and the dermis. The dermis of the dorsal skin of nonreproductive and reproductive females lacks a distinct stratum compactum, which is typical for most anuran skins. The entire dermis shows irregularly arranged collagen bundles like a stratum spongiosum. Before egg laying, the skin swells, primarily by thickening and further by loosening of the middle zone of the dermis. In the epidermis, large furrows develop that are the prospective sites of egg nidation. The epidermis, which forms a brood chamber around the developing egg becomes bi‐layered and very thin and lacks a stratum corneum. Further, the dermis loosens and becomes heavily vascularized. Egg carrying females do not have mature oocytes in their ovaries indicating a slow down or interruption of egg maturation during this period. Similarities with the brood pouch of marsupial frogs are discussed. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.
Identification of intact oxidation products of glycerophospholipids in vitro and in vivo using negative ion electrospray iontrap mass spectrometry
Authors: Yin Huiyong , Cox Brian E. , Liu Wei , Porter Ned A. , Morrow Jason D. , Milne Ginger L.
Published: May 2009

Free radical‐induced oxidation products of polyunsaturated fatty acids esterified to phospholipids have been implicated in a number of human diseases including atherosclerosis and neurodegenerative diseases. Some of these phospholipid oxidation products have potent biological activities and likely contribute to human pathophysiological conditions. Oxidation products have also been used as markers of oxidative stress in vivo. Identification and quantification of phospholipid oxidation products are often performed by analyzing the oxidized free fatty acid moieties after hydrolysis from the phospholipids head groups by gas chromatography–mass spectrometry (GC–MS) or liquid chromatography–mass spectrometry (LC–MS). We now describe the definitive identification of intact oxidized products of glycerophospholipids including glycerophosphatidylcholine (GPC), glycerophosphatidylethanolamine (GPE), and glycerophosphatidylserine (GPS) in vitro and in vivo using iontrap MS. For these analyses, the negative ions of the oxidation products of phospholipids are fragmented to MSn and unequivocal structural characterization is obtained based on collision‐induced dissociation (CID) of the sn‐2 carboxylate ion. This technique overcomes the need to hydrolyze fatty acids from phospholipids in the analysis. The method has been used to identify a number of oxidation products of glycerophospholipids including hydroxyeicosatetraenoates (HETEs) and isoprostanes (IsoPs) esterified to different classes of glycerophospholipids in vitro and in vivo. These studies thus provide a new approach to identify the intact oxidation products of glycerolphospholipids. Copyright © 2009 John Wiley & Sons, Ltd.
Reactivity of Tyr–Leu and Leu–Tyr dipeptides: identification of oxidation products by liquid chromatography–tandem mass spectrometry
Authors: Fonseca Conceição , Domingues M. Rosário M. , Simões Cláudia , Amado Francisco , Domingues Pedro
Published: May 2009

The exposure of peptides and proteins to reactive hydroxyl radicals results in covalent modifications of amino acid side‐chains and protein backbone. In this study we have investigated the oxidation the isomeric peptides tyrosine–leucine (YL) and leucine–tyrosine (LY), by the hydroxyl radical formed under Fenton reaction (Fe2+/H2O2). Through mass spectrometry (MS), high‐performance liquid chromatography (HPLC‐MS) and electrospray tandem mass spectrometry (HPLC‐MSn) measurements, we have identified and characterized the oxidation products of these two dipeptides. This approach allowed observing and identifying a wide variety of oxidation products, including isomeric forms of the oxidized dipeptides. We detected oxidation products with 1, 2, 3 and 4 oxygen atoms for both peptides; however, oxidation products with 5 oxygen atoms were only present in LY. LY dipeptide oxidation leads to more isomers with 1 and 2 oxygen atoms than YL (3 vs 5 and 4 vs 5, respectively). Formation of the peroxy group occurred preferentially in the C‐terminal residue. We have also detected oxidation products with double bonds or keto groups, dimers (YL–YL and LY–LY) and other products as a result of cross‐linking. Both amino acids in the dipeptides were oxidized although the peptides showed different oxidation products. Also, amino acid residues have shown different oxidation products depending on the relative position on the dipeptide. Results suggest that amino acids in the C‐terminal position are more prone to oxidation. Copyright © 2009 John Wiley & Sons, Ltd.
Raman and infrared analysis of glues used for pottery conservation treatments
Authors: Asquier Magali , Colomban Philippe , Milande Véronique
Published: May 2009

The conservation of ceramics and glass involves the repair or the restoration of broken and fragmented artefacts with polymer adhesives and gap fillers. In the past, many different adhesives had been used. Re‐restoration is often required and the fast identification of adhesive residues on objects would be very useful to define the best of way to remove them, in particular to avoid the use of noxious chemicals. Sixteen pottery artefacts restored during the 19th and 20th centuries at the Musée National de Céramique in Sèvres have been analysed by non‐destructive Raman microspectroscopy. For comparison purposes, the artefacts were also sampled in order to acquire infrared (IR) absorption spectra in KBr pellets. Modern adhesives (methyl metacrylate/acrylate, vinyl acetate, polychloroprene, methyl 2‐cyanoacrylate and diglycidylether biphenol) were also characterised with the same methods. IR and Raman spectra were obtained for all ancient glue residues, but among the 16 analysed items, only 7 adhesives have been identified unambiguously, and an assignment proposed for 4 others solely on the basis of the Raman signature. Copyright © 2009 John Wiley & Sons, Ltd.
A resonance Raman spectroscopic investigation into the effects of fixation and dehydration on heme environment of hemoglobin
Authors: Asghari‐Khiavi Mehdi , Mechler Adam , Bambery Keith R. , McNaughton Don , Wood Bayden R.
Published: May 2009

The effects of fixation and dehydration procedures on heme environment inside human erythrocytes were examined using resonance Raman spectroscopy. The resonance Raman spectroscopic data along with far‐infrared spectra show that hemoglobin in air‐dried red blood cells and those fixed in the precipitating fixatives, methanol and acetone, changes to hemichrome, a low‐spin component in which the sixth coordination site of the iron is occupied by the imidazole group of the distal histidine. The cross‐linking fixatives, formaldehyde and glutaraldehyde, maintain hemoglobin in its native conformational state (oxyhemoglobin) as evidenced by the appearance of the oxygen ligand marker bands along with the skeletal sensitive modes. However, polymerization with cross‐linking fixatives increases the auto‐oxidation kinetics of hemoglobin and gradually oxidizes it to the met state. Moreover, the dehydration of a red blood cell under N2 results in a change of oxyhemoglobin to a six coordinate low‐spin FeII derivative of hemoglobin, hemochrome. Copyright © 2009 John Wiley & Sons, Ltd.
Structural modifications in metal complexes of a plant metallothionein caused by reductive radical stress: a Raman study
Authors: Torreggiani Armida , Domènech Jordi , Tinti Anna
Published: May 2009

The effect of radical stress in the biological environment is a very active field of research connecting various disciplines of life science. Thus, a comprehensive vision of all possible reactive species is necessary for contributing to the solution of puzzling questions on free radicals. In this contest, damages to Zn(II) and Cd(II) complexes of a plant metallothionein (Quercus suber—QsMT), because of reductive radical stress, were investigated by Raman spectroscopy. QsMT is a low‐molecular‐weight cysteine‐rich protein obtained by in vivo synthesis to have a physiologically representative model. Gamma‐irradiation was used to simulate the endogenous formation of reductive species. By changing the appropriate conditions of irradiation, a selection of the reacting radical species (hydrogen atom and hydrated electron) was carried out. Specific damages occur at sensitive amino acid sites, selectively, rather than indiscriminately. In particular, Cys resulted to be among the most sensitive residues toward radical attack, suggesting that the thiolate clusters of both metal and QsMTs act as efficient interceptors of reducing species. Under reductive stress, Zn–QsMT undergoes a significant thiolate group oxidation and the participation of ligands other than the cysteine‐derived thiolate bonds (i.e. His) in zinc coordination becomes necessary for the protein stabilization. Regarding Met residues, they resulted to be more sensitive to the reductive radical attack when the protein binds Cd(II) ions, indicating that the protein structure can play a significant role in blocking the ready access of free radicals to the sulfur‐containing residues, so strongly affecting the radiosensitivity of the protein. In conclusion, the results obtained from γ‐irradiation experiments indicate that reductive stress causes changes in the primary QsMT structure and in the secondary and tertiary structures, and the radical‐induced effects are dependent on the metal bound. Copyright © 2009 John Wiley & Sons, Ltd.
Temperature‐depending Raman line‐shift of silicon carbide
Authors: Bauer Michael , Gigler Alexander M. , Huber Andreas J. , Hillenbrand Rainer , Stark Robert W.
Published: May 2009

Silicon carbide (SiC) is often used for electronic devices operating at elevated temperatures. Spectroscopic temperature measurements are of high interest for device monitoring because confocal Raman microscopy provides a very high spatial resolution. To this end, calibration data are needed that relate Raman line‐shift and temperature. The shift of the phonon wavenumbers of single crystal SiC was investigated by Raman spectroscopy in the temperature range from 3 to 112°C. Spectra were obtained in undoped 6HSiC as well as in undoped and nitrogen‐doped 4HSiC. All spectra were acquired with the incident laser beam oriented parallel as well as perpendicular to the c‐axis to account for the anisotropy of the phonon dispersion. Nearly all individual peak centers were shifting linearly towards smaller wavenumbers with increasing temperature. Only the peak of the longitudinal optical phonon A1(LO) in nitrogen‐doped 4HSiC was shifting to larger wavenumbers. For all phonons, a linear dependence of the Raman peaks on both parameters, temperature and phonon frequency, was found in the given temperature range. The linearity of the temperature shift allows for precise spectroscopic temperature measurements. Temperature correction of Raman line‐shifts also provides the ability to separate thermal shifts from mechanically induced ones. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of cooking and reheating methods on the fatty acid profile of sea bream treated with rosemary extract
Authors: Ozogul Yesim , Ozyurt Gulsun , Kuley Boga Esmeray
Published: May 2009

BACKGROUND:The effects of rosemary extract on the fatty acid profile of sea bream fillets cooked by different methods (oven baking, grilling and pan frying) as well as the effects of different reheating methods (microwave and conventional oven) on the fatty acid composition of fish after frozen storage for 4 months were investigated.

RESULTS:The proportion of saturated fatty acids increased only slightly in fried samples but significantly in oven‐baked and grilled samples, while the proportion of polyunsaturated fatty acids (PUFAs) increased significantly in fried samples but only slightly in oven‐baked and grilled samples. The proportion of monounsaturated fatty acids remained relatively constant after cooking. Of the fatty acids analysed, the most significant increases (P< 0.05) were observed in C18:1n‐9 and C18:2n‐6 and the most significant decreases (P< 0.05) in C14:0, C16:1, C20:5n‐3 and C22:6n‐3. Although sea bream fillets fried in sunflower oil showed an increase in PUFAs, the lowest eicosapentaenoic and docosahexaenoic acid contents were found in fried samples.

CONCLUSION:Sea bream fillets treated with rosemary extract showed slower oxidation than untreated fish. Neither conventional nor microwave reheating after frozen storage for 4 months had a detrimental effect on the fatty acid profile and its stability. Copyright © 2009 Society of Chemical Industry
Chemical characterisation of CTC black tea of northeast India: correlation of quality parameters with tea tasters' evaluation
Authors: Bhuyan Lakshi P , Hussain Assma , Tamuly Pradip , Gogoi Ramen C , Bordoloi Prasanna K , Hazarika Mridul
Published: May 2009

BACKGROUND: Consumers have different regional perceptions of tea quality. Objective evaluation based on biochemical data for different regions has been needed for a long time. Biochemical factors regulating this variation would help to remove regional disparities. This study was undertaken on CTC (crust, tear and curl) black tea to generate the biochemical data responsible for quality along with tea tasters' evaluation of three geographical regions of northeast India and to determine the reason for the variation.

RESULTS: Brahmaputra valley teas had highest theaflavin (TF), thearubigin (TR), brightness (BR) and total colour (TC) and low crude fibre content (CFC) and total polyphenol (TPP). Brahmaputra valley and Dooars region teas showed high total soluble solid (TSS). Barak valley teas had highest CFC and low TSS, caffeine (CA), TF, TR and TC. Dooars region teas had high CA and TPP and low BR. Dooars region and Barak valley teas contained higher levels of residual catechin than Brahmaputra valley teas.

CONCLUSION: Overall quality as evaluated by tea tasters was found to be highest for Brahmaputra valley teas followed by Dooars region and Barak valley teas. This high evaluation can be attributed to higher levels of TF, TR, BR and TSS. Barak valley and Dooars region teas contained high residual catechin, indicating limitation in oxidation during processing. Copyright © 2009 Society of Chemical Industry
Time for a shift in crop production: embracing complexity through diversity at all levels
Authors: Østergård Hanne , Finckh Maria R , Fontaine Laurence , Goldringer Isabelle , Hoad Steve P , Kristensen Kristian , Lammerts van Bueren Edith T , Mascher Fabio , Munk Lisa , Wolfe Martin S
Published: May 2009

A radical shift in our approach to crop production is needed to ensure food security and to address the problems of soil degradation, loss of biodiversity, polluted and restricted water supplies, coupled with a future of fossil fuel limitations and increasingly variable climatic conditions. An interdisciplinary network of European scientists put forward visions for future crop production embracing the complexity of our socio‐ecological system by applying the principle of diversity at all levels from soil micro‐organisms to plant varieties and cropping systems. This approach, integrated with careful deployment of our finite global resources and implementation of appropriate sustainable technology, appears to be the only way to ensure the scale of system resilience needed to cope with many of our concerns. We discuss some of the most important tools such as (i) building soil fertility by recycling of nutrients and sustainable use of other natural and physical resources, (ii) enhancing biological diversity by breeding of crops resilient to climate change and (iii) reconnecting all stakeholders in crop production. Finally, we emphasise some of the changes in agricultural and environmental regulation and policy needed in order to implement the visions. Copyright © 2009 Society of Chemical Industry
Instrumental and sensory characterisation of industrially processed applesauces
Authors: Colin‐Henrion Muriel , Mehinagic Emira , Patron Corinne , Jourjon Frédérique
Published: May 2009

BACKGROUND: In the context of fruit consumption promotion, applesauce is an interesting ready‐to‐eat product. However, little information has been gathered on its sensory properties. Yet, the processing involved easily triggers rheological and structural changes, possibly modifying these sensory properties. The aim of this study was thus to provide a global approach for applesauce characterisation by studying instrumental and sensory properties, with knowledge of the processing conditions applied. Four applesauce samples processed under controlled parameters were therefore compared with seven purchased applesauces.

RESULTS: The four studied samples were characterised by their high creaminess and low graininess. These products were homogeneous and presented a small average particle size (332–354 µm). Their flow properties were best described with the Hershel–Bulkey model. The products were shear‐thinning with low yield stress. Interestingly, significant differences in textural and flow properties were also found among these four manufactured samples.

CONCLUSION: Sensory characterisation revealed aromatic and textural diversity even though applesauce is considered as a common product. Differences found among the samples of interest might be related to postharvest maturity of fruits and consequent pectic degradation from cell walls. Finally, the candied odour and flavour that distinguished these products could be related to the extensive heating applied during processing. Copyright © 2009 Society of Chemical Industry
Optimization of hydrolysis of sardine (Sardina pilchardus) heads with Protamex: enhancement of lipid and phospholipid extraction
Authors: Dumay Justine , Allery Marion , Donnay‐Moreno Claire , Barnathan Gilles , Jaouen Pascal , Carbonneau Marie Elise , Bergé Jean Pascal
Published: May 2009

BACKGROUND: Fish by‐products are not considered as valuable raw materials even if they usually contain valuable components such as lipids. Fish lipids are well known for their nutritional potential and health effects but their extraction remains problematic due to the use of organic solvents. Enzymatic hydrolysis such as the proteolysis of tissues can lead to lipid extraction.

RESULTS: Hydrolysis of sardine heads by Protamex was studied (temperature, hydrolysis time and enzyme–substrate ratio) using response surface methodology in order to obtain the highest release of lipids and particularly phospholipids. No relation between the degree of hydrolysis and lipid recovery were depicted; however, optimum conditions for both the release of lipids and phospholipids were found to be similar (29 min, 31 °C with 2.6 g kg−1 enzyme). Under these hydrolysis conditions, rich lipid and phospholipid fractions (oily and aqueous fractions) can be recovered when time, temperature and enzyme consumption are minimized. Analytical data have revealed that they contain high‐quality lipids, especially ω3 fatty acid.

CONCLUSION: This study demonstrated that proteolysis can be used for high lipid recovery from little‐exploited biomass like fish heads without requiring solvent or thermal treatment. Resulting phospholipids, fatty acids and peptides could be utilized for nutritional or feed purposes. Copyright © 2009 Society of Chemical Industry
A contemporary review of voice and airway after laryngeal trauma in children
Authors: Quesnel Alicia M. , Hartnick Christopher J.
Published: May 2009

Objectives/Hypothesis:

To discuss three cases of pediatric laryngeal trauma that highlight current techniques in diagnosis and treatment of the voice following laryngeal trauma. To examine the diagnostic utility of “chip tip” video laryngoscopy and to explore the current uses for open, endoscopic, or combined approaches within the context of these cases.

Study Design:

Case series with review of contemporary techniques.

Methods:

A case series of three children who sustained laryngeal trauma is presented. Ages range from 6 weeks to 17 years. The diagnostic evaluation and treatment strategies are reviewed with a focus on contemporary techniques.

Results:

A 15‐year‐old boy who sustained blunt neck trauma was diagnosed with a vocal fold avulsion on video laryngoscopy with digital image processing and a significant mucosal tear with exposure of the paraglottic space on direct laryngoscopy. Anatomical reapproximation required a combined open and endoscopic repair. A 17‐year‐old football player developed a glottic hematoma after blunt cervical trauma. This was managed conservatively with serial chip tip video laryngoscopy that provided high fidelity images and facilitated proper and timely diagnosis and treatment. A 6‐week‐old male suffered vocal fold avulsion from a traumatic intubation. Laryngofissure with reattachment of the vocal fold resolved his aspiration and reconstructed the laryngeal anatomy.

Conclusions:

Enhanced imaging via chip tip video laryngoscopy, compared to conventional fiberoptic endoscopy, might provide additional diagnostic information in pediatric patients with laryngeal trauma. Additionally, there could be a role for video strobolaryngoscopy in selected laryngeal trauma patients. Open, endoscopic, and combined approaches could be used to optimize voice and swallowing outcomes in pediatric laryngeal trauma. Laryngoscope, 2009
Enzyme‐Free Quinone Crosslinking Reaction for Proteins: A Macromolecular Characterization Study Using Gelatin
Authors: Yamauchi Asao , Hatanaka Yoshiro , Muro Tetsuo , Kobayashi Osamu
Published: May 2009

To mimic the quinone hardening of extracellular proteins in invertebrates, we investigated an enzyme‐free crosslinking of gelatin by HQ in a neutral aqueous phase. The mixture was rapidly transformed to a yellowish brown, thermally and mechanically stable hydrogel in the presence of a simple copper(II) salt. A dehydrated thin film made of the mixture was flexible, tough, and showed a large ultimate breaking force. Physicochemical examination of the gel suggested that the basic amino acid residues (lysine, hydroxylysine, and histidine) of the protein were modified by the quinone ring to form 2–6 crosslinks per protein. The enzyme‐free crosslinking reaction is discussed with consideration of a copper(II) ion‐catalyzed oxidation of HQ and the hydroquinone/protein adducts.

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A Hybrid DNA Aptamer–Dendrimer Nanomaterial for Targeted Cell Labeling
Authors: Zhou Jing , Soontornworajit Boonchoy , Martin Jacob , Sullenger Bruce A. , Gilboa Eli , Wang Yong
Published: May 2009

Antibodies are natural nanomaterials and have been widely used for targeted cell labeling. However, the applications of antibodies are often limited by their large size and instability. The purpose of this study is to develop a new type of multifunctional nanomaterial that is comprised of a nucleic acid aptamer and a dendrimer, both of which are stable. This nanomaterial is ≈8 nm in size. Moreover, it could not only carry multiple signal molecules, but also bind to target cancer cells with high affinity and specificity. This sub‐10 nm multifunctional nanomaterial is expected to be useful in basic biomedical research and clinical medicine.

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Morphology, Crystallization Behavior, and Mechanical Properties of Isotactic Poly(propylene) Nanocomposites based on Organophilic Boehmites
Authors: Streller Rouven C. , Thomann Ralf , Torno Olaf , Mülhaupt Rolf
Published: May 2009

iPP/organoboehmite nanocomposites were prepared to examine the influence of both boehmite crystallite size and organophilic boehmite modification on morphology development, thermal, and mechanical properties. Effective deagglomeration of the micrometer‐scaled organoboehmites was achieved, producing uniform dispersions of nanometer‐scaled boehmite crystallite assemblies within the iPP matrix. CS‐modified organoboehmites gave improved stiffness at the expense of elongation at break and impact strength. In contrast to CS, boehmites modified with OS2 lowered iPP crystallization (“anti‐nucleation effect”) without affecting crystal modification, affording iPP nanocomposites with significantly larger elongation at break and strain induced crystallization.

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Structure and Pervaporation Properties of Poly(phenylene‐iso‐phthalamide) Membranes Modified by Fullerene C60
Authors: Penkova Anastasia V. , Polotskaya Galina A. , Toikka Alexander M. , Trchová Miroslava , Šlouf Miroslav , Urbanová Martina , Brus Jiří , Brožová Libuše , Pientka Zbyněk
Published: May 2009

Homogeneous membranes based on PA/C60 composites were obtained and their internal morphology was visualized using SEM. The interaction between PA and C60 was studied by spectroscopic methods. The effect of C60 inclusion in the PA matrix on physical properties was characterized by measurement of the intrinsic viscosity, density, and glass transition temperature. Transport properties of pure PA and composite membranes were studied in pervaporation of the methanol/cyclohexane mixture. It was found that all membranes were essentially permeable for methanol. The permeability and so‐called inverse selective separation properties were improving for membranes containing 2 and 5 wt.‐% C60, whereas they decreased for higher C60 content.

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pH‐ and Temperature‐Responsive Behavior of Comb‐Type Graft Hydrogels of Poly(acrylic acid) Synthesized Using Gamma Radiation
Authors: Illescas Javier , Burillo Guillermina
Published: May 2009

A pH sensitive hydrogel was obtained by γ‐ray radiation polymerization of AAc in aqueous solution. The temperature sensitive monomer NIPAAm or the same pH sensitive AAc monomer was then grafted to the PAAc hydrogel with gamma radiation. The comb‐type graft polymers obtained net‐AAc‐g‐NIPAAm and the net‐AAc‐g‐AAc, have been studied through determination of graft yield and swelling behavior at room temperature. The critical pH value was found between 4.5 and 5.5. An unexpected unique behavior with an UCST has been found around 30–32 °C. Other techniques employed to characterize the comb‐type polymer included DSC, SEM, and FTIR‐ATR.

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Thermoplastic Polyurethanes with TDI‐Based Monodisperse Hard Segments
Authors: De Debasish , Gaymans Reinoud J.
Published: May 2009

Polyurethanes with PTMO soft segments and toluene diisocyanate diamide as urethane segment were studied. The toluene diisocyanate diamide urethane segment was monodisperse in length. The soft segment length was changed by extending PTMO with TDI units to a soft segment length varying from 2 250 to 6 500 g · mol−1. Studied were the structure, the morphology, the thermal and thermal mechanical behavior, the elastic behavior, and the tensile properties. The monodisperse diisocyanate diamide urethane segments had a high crystallinity and the crystallites showed a curved nano‐ribbon morphology. Extending the PTMO units with TDI groups increased Tg and Tm of PTMO slightly, and the elastic properties at room temperature were not affected.

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Design and Synthesis of Fast‐Degrading Poly(anhydride‐esters)
Authors: Carbone Ashley L. , Uhrich Kathryn E.
Published: May 2009

Fast‐degrading, salicylate‐based poly(anhydride‐esters) were designed to degrade and release the active component, salicylic acid (SA), within 1 week. The polymer degradation was enhanced by using shorter or oxygen‐containing aliphatic chains. A copolymer of diglycolic acid was also made with a salicylate‐based diacid for comparison of polymer properties, including SA release. Both methods resulted in polyanhydrides with molecular weights ranging from 14 500 to 27 800 Da and displayed glass transition temperatures near physiological conditions, namely 33–40 °C. The homo‐ and copolymers completely degraded within one week releasing the chemically incorporated SA.

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Organic/Organic′ Heterojunctions: Organic Light Emitting Diodes and Organic Photovoltaic Devices
Authors: Armstrong Neal R. , Wang Weining , Alloway Dana M. , Placencia Diogenes , Ratcliff Erin , Brumbach Michael
Published: May 2009

Heterojunctions created from thin films of two dissimilar organic semiconductor materials [organic/organic′ (O/O′) heterojunctions] are an essential component of organic light emitting diode displays and lighting systems (OLEDs, PLEDs) and small molecule or polymer‐based organic photovoltaic (solar cell) technologies (OPVs). O/O′ heterojunctions are the site for exciton formation in OLEDs, and the site for exciton dissociation and photocurrent production in OPVs. Frontier orbital energy offsets in O/O′ heterojunctions establish the excess free energy controlling rates of charge recombination and formation of emissive states in OLEDs and PLEDs. These energy offsets also establish the excess free energy which controls charge separation and the short‐circuit photocurrent (JSC) in OPVs, and set the upper limit for the open‐circuit photopotential (VOC). We review here how these frontier orbital energy offsets are determined using photoemission spectroscopies, how these energies change as a function of molecular environment, and the influence of interface dipoles on these frontier orbital energies. Recent examples of heterojunctions based on small molecule materials are shown, emphasizing those heterojunctions which are of interest for photovoltaic applications. These include heterojunctions of perylenebisimide dyes with trivalent metal phthalocyanines, and heterojunctions of titanyl phthalocyanine with C60, and with pentacene. Organic solar cells comprised of donor/acceptor pairs of each of these last three materials confirm that the VOC scales with the energy offsets between the HOMO of the donor and LUMO of the acceptor ($E_{{\rm HOMO}^{\rm D} } - E_{{\rm LUMO}^{\rm A} }$).

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Oligomerization of Electron‐Deficient Vinyl Monomers Through an Ate‐Complex Mechanism: A New Role for B(C6F5)3 Lewis Acid
Authors: Pouget Emmanuel , Holgado‐Garcia Erlea , Vasilenko Irina V. , Kostjuk Sergei V. , Campagne Jean Marc , Ganachaud Francois
Published: May 2009

The Lewis acid B(C6F5)3 in combination with hydrosilanes exhibits remarkable activity in the oligomerization of sulfone‐ and phosphonate‐based monomers. This process opens new routes to high‐tech silicone‐based materials, i.e., thermoplastic elastomers and heat‐resistant polysiloxanes.

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Gold Nanoparticle‐Hybridized “Nano‐Sponge” Polymer Coatings to Enhance the Reliability and Sensitivity of Biosensors
Authors: Jeong Hyung‐Jun , Pyun Won‐Hee , Yang Sung Yun
Published: May 2009

We have created a new functional biosensor coating composed of polyelectrolyte multilayers containing gold nanoparticles. This gold‐hybridized polyelectrolyte multilayer film possesses a stable nanoporous structure under physiological conditions. Antibody molecules were successfully conjugated onto the gold nanoparticles within the film. This functional coating successfully extinguished false signals from non‐specific binding of proteins and cells and also provided highly enhanced detection sensitivity. Furthermore, the drastic differences in protein and cellular adhesion properties between a chip coated with the nanoporous PEM film and a bare chip demonstrate that morphological control of biological interactions on chip surfaces is possible.

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Effect of substituents on spin density in benzimidazole nitronyl nitroxide radicals studied by electron spin resonance
Authors: Esat Burak , Fidan Ismail , Bahceci Sumeyye , Yerli Yusuf , Sari Levent
Published: May 2009

Several novel benzimidazole‐3‐oxide‐1‐oxyl radicals with substituents at 5 and/or 6 position were synthesized. The ESR analysis of nitrogen hyperfine coupling constants (hfccs) revealed that substituents at 5 and 6‐position affect the spin density to greater extent than substituents on the phenyl ring at 2‐position. Density functional theory calculations of nitrogen hfccs were performed using several different Pople type basis sets, as well as double and triple zeta quality individual gauge for localized orbital (IGLO‐II, IGLO‐III) and electron paramagnetic resonance (EPR‐II, EPR‐II) basis sets. Experimental and theoretical hfccs are compared. Copyright © 2009 John Wiley & Sons, Ltd.
Controlled Catalyst Dosing: An Elegant Approach in Molecular Weight Regulation for UHMWPE
Authors: Padmanabhan Sudhakar , Sarma Krishna R. , Sharma Shashikant , Patel Viral
Published: May 2009

Ethylene polymerization using Ziegler‐Natta catalysts comprising TiCl4 supported on MgCl2 with aluminum alkyls as co‐catalyst produce UHMWPE through a mediated proportional reduction of the Ti oxidation states. We observe the molecular weight regulation to be a combined function of hydrogen and the co‐catalyst through experimental evidences. The role of unavoidable chain transfer reactions for molecular weight regulation has been observed during the production of UHMWPE along with H2 through controlled catalyst dosing. Process optimization studies at 7.5 atm ethylene pressure could absorb small deviations in the catalyst systems to maintain the desired molecular weights.

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