bluuebunny/crossref_metadata_2025 huggingface dataset:
Solid‐Phase Synthesis of Chiral Modular Ferrocene‐Based Peptides
Authors: Heinze Katja , Wild Ute , Beckmann Manuela
Published: December 2006

Ferrocene‐containing tripeptides with one to two ferrocene building blocks were prepared by solid‐phase peptide synthesis (SPPS) using Fmoc‐protected 1′‐aminoferrocene‐1‐carboxylic acid (Fca). The conformations of the tripeptides were analysed by spectroscopic and theoretical methods. The immobilised ferrocene compounds can be reversibly oxidised on‐bead to positively charged peptides and were analysed for anion‐binding affinities by a solid‐phase binding assay. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Group 11 Metal Complexes of the Mesocyclic Thioether Aminophosphonites [‐OC10H6(μ‐S)C10H6O‐]PNC4H8E (E = O, NMe)
Authors: Punji Benudhar , Mague Joel T. , Balakrishna Maravanji S.
Published: December 2006

Group 11 metal complexes of the mesocyclic thioether aminophosphonites [‐OC10H6(μ‐S)C10H6O‐]PNC4H8E {2a: E = O; 2b: E = NMe; IUPAC names: 4‐(dinaphtho[2,1‐d:1′,2′‐g][1,3,6,2]dioxathiaphosphocin‐4‐yl)morpholine (2a), 1‐(dinaphtho[2,1‐d:1′,2′‐g][1,3,6,2]dioxathiaphosphocin‐4‐yl)‐4‐methylpiperazine (2b)} are reported. Thioether aminophosphonites 2a and 2b react with CuX (X = Cl, Br, and I) in a 1:1 molar ratio to give the tricoordinate, dimeric complexes [{[{‐OC10H6(μ‐S)C10H6O‐}PNC4H8E‐κP]Cu(μ‐X)}2] (4a: E = O, X = Cl; 4b: E = NMe, X = Cl; 5a: E = O, X = Br; 5b: E = NMe, X = Br; 6a: E = O, X = I; 6b: E = NMe, X = I), whereas with 2:1 molar ratios monomeric complexes of the type[{[‐OC10H6(μ‐S)C10H6O‐]PNC4H8O‐κP}2CuX] (7a: E = O, X = Cl; 7b: E = NMe, X = Cl; 8a: E = O, X = Br; 8b: E = NMe, X = Br; 9a: E = O, X = I; 9b: E = NMe, X = I) are obtained in excellent yield. The P,S‐chelated cationic complexes[{[‐OC10H6(μ‐S)C10H6O‐]PNC4H8E‐κP,κS}2Cu]BF4 (10a: E = O; 10b: E = NMe) are obtained when 2a and 2b are treated with half an equivalent of [(MeCN)4Cu]BF4. Similarly, thesilver complexes [{[{‐OC10H6(μ‐S)C10H6O‐}PNC4H8E‐κP,κS]AgCF3SO3}2] (11a: E = O: 11b: E = NMe) and [{[‐OC10H6(μ‐S)C10H6O‐]PNC4H8E‐κP,κS}Ag(PPh3)]CF3SO3 (12a: E = O; 12b: E = NMe) are synthesized by the treatment of thioether aminophosphonites 2a and 2b with AgOTf and [Ag(PPh3)][OTf], respectively. Reactions of 2a and 2b with [AuCl(SMe2)] produce the simple monomeric gold(I) complexes [{[‐OC10H6(μ‐S)C10H6O‐]PNC4H8E‐κP}AuCl] (13a: E = O; 13b: E = NMe). The iodo derivatives [{[‐OC10H6(μ‐S)C10H6O‐]PNC4H8E‐κP}AuI] (14a: E = O; 14b: E = NMe) are obtained by the halide‐exchange reaction of 13a and 13b with CuI at room temperature. The structures of complexes 5a, 7a, 8a, 13a, 13b, and 14a are confirmed by single‐crystal X‐ray diffraction studies. In all of these complexes, the sulfur atom in the mesocyclic ring shows coordinative interaction towards the phosphorus atom, and in 5a, 7a, 8a, and 14a towards the metal center as well. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Regio‐ and Stereoselectivity of Ene Reactions: The Dimerization of Bicyclic 1,3‐Fused 2‐(Trimethylsilyl)cycloprop‐1‐enes
Authors: Chen Ko Chou , Wang Wen Chieh , Chen Mei‐Yun , Chen Wei‐Cheng , Her Ming‐Chieh , Lee Gon‐Ann
Published: December 2006

Cycloalkenes proceed through bromination, dehydrobromination and dibromocarbene addition reactions to give tribromocyclopropanes 10 and 11. The treatment of tribromocyclopropanes 10 and 11 with 3 equiv. of methyllithium in diethyl ether at –78 °C followed by treatment with trimethylsilyl chloride produce 8‐(trimethylsilyl)bicyclo[5.1.0]oct‐1(8)‐ene (4) and 9‐(trimethylsilyl)bicyclo[6.1.0]non‐1(9)‐ene (5). Both 4 and 5 undergo ene dimerization via the same steric isomer and an endo transition state to generate the stable adducts 6 and 7, respectively, as the sole isomers. Compound 6, containing an unstable bicyclo[5.1.0]oct‐1(8)‐enyl group and produced in high yields, has been reported to be an unstable species. Both of the ene dimers, (trimethylsilyl)cyclopropenes 6 and 7, can be converted into cyclopropenes 8 and 9 by treatment with a fluoride salt followed by protonation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Diastereoselective Diels–Alder Additions of Ethene to Substituted Homochiral 2(1H)‐Pyrazinones
Authors: Alen Jo , Smets Wim J. , Dobrzańska Liliana , De Borggraeve Wim M. , Compernolle Frans , Hoornaert Georges J.
Published: December 2006

Diels–Alder reactions of ethene with 2(1H)‐pyrazinones bearing a homochiral auxiliary group are presented. The cycloaddition products form with diasteromeric excesses of up to 50 %. To the best of our knowledge, these are the firstDiels–Alder reactions with ethene showing some degree of diastereoselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Phenylphosphoric Acid as a New Additive to Inhibit Olefin Isomerisation in Ruthenium‐Catalysed Metathesis Reactions
Authors: Gimeno Nélida , Formentín Pilar , Steinke Joachim H. G. , Vilar Ramón
Published: December 2006

A systematic study of the ruthenium‐catalysed metathesis of alkenes containing hydrogen‐bonding substituents (namely urea and thiourea groups) is presented. Under standard metathesis conditions, several of the substrates under study undergo alkene isomerisation instead of the targeted metathesis. However, in the course of these investigations it has been established that this unwanted isomerisation process can be suppressed by addition of phenylphosphoric acid to the reaction mixture. Some other potential isomerisation inhibitors (e.g. benzoic acid and salts of phosphoric acid) have been studied and their performance compared to that of phenylphosphoric acid. To extend the scope of phenylphosphoric acid, we also studied the metathesis of 1,3‐diallylurea. Interestingly, not only did we observe the complete suppression of the isomerisation process, but also that it is possible to obtain instead of the ring‐closing metathesis (RCM) product,ADMET oligomers resulting from the cross‐metathesis of diallylurea at higher concentrations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A proteomic analysis of Psychrobacter articus 273‐4 adaptation to low temperature and salinity using a 2‐D liquid mapping approach
Authors: Zheng Suping , Ponder Monica A. , Shih Janice Yang Jen , Tiedje James M. , Thomashow Michael F. , Lubman David M.
Published: December 2006

Psychrobacter 273‐4 was isolated from a 20 000–40 000–year‐old Siberian permafrost core, which is characterized by low temperature, low water activity, and high salinity. To explore how 273‐4 survives in the permafrost environment, proteins in four 273‐4 samples cultured at 4 and 22°C in media with and without 5% sodium chloride were profiled and comparatively studied using 2‐D HPLC and MS. The method used herein involved fractionation via a pH gradient using chromatofocusing followed by nonporous silica (NPS) RP‐HPLC and on‐line electrospray mass mapping. It was observed that 33 proteins were involved in the adaptation to low temperature in the cells grown in the nonsaline media while there were only 14 proteins involved in the saline media. There were 45 proteins observed differentially expressed in response to salt at 22°C while there were 22 proteins at 4°C. In addition, 5% NaCl and 4°C showed a combination effect on protein expression. A total of 56 proteins involved in the adaptation to low temperature and salt were identified using MS and database searching. The differentially expressed proteins were classified into different functional categories where the response of the regulation system to stress appears to be very elaborate. The evidence shows that the adaptation of 273‐4 is based primarily on the control of translation and transcription, the synthesis of proteins (chaperones) to facilitate RNA and protein folding, and the regulation of metabolic pathways.
Application of Hadamard transformation to MEKC
Authors: Hata Kazuki , Kaneta Takashi , Imasaka Totaro
Published: December 2006

The Hadamard transform (HT) technique, which permits the S/N in CE to be improved, was applied to MEKC. Multiple sample injection of fluorescent analytes according to a Hadamard code sequence was performed using an optically gated sample injection technique, in which a sample plug was produced based on photodegradation by irradiation with an intense laser beam. The capillary and reservoirs were filled with a sample solution containing buffer components and SDS as a pseudostationary phase. A preliminary study confirmed that fluorescein ion could be photobleached in the presence of SDS. The optically gated sample injection technique was then applied to multiple sample injection, based on a Hadamard matrix. The S/N in the electropherogram obtained by HT‐MEKC was improved substantially compared to that obtained by a single injection method. When the technique was applied to the separation of several amino acids labeled with FITC, the S/N ratio for each amino acid was enhanced, without any evidence of degradation in separation resolution. Moreover, HT‐MEKC was applied to the analysis of amino acids contained in a Japanese beverage, resulting in improved S/Ns for the amino acids.
Employment‐contingent health insurance, illness, and labor supply of women: evidence from married women with breast cancer
Authors: Bradley Cathy J. , Neumark David , Luo Zhehui , Bednarek Heather L.
Published: December 2006

We examine the effects of employment‐contingent health insurance (ECHI) on married women's labor supply following a health shock. First, we develop a theoretical framework that examines the effects of ECHI on the labor supply response to a health shock, which suggests that women with ECHI are less likely to reduce their labor supply in response to a health shock, relative to women with health insurance through their spouse's employer. Second, we empirically examine this relationship based on labor supply responses to breast cancer. We find that health shocks decrease labor supply to a greater extent among women insured by their spouse's policy than among women with health insurance through their own employer, suggesting that ECHI creates incentives to remain working when faced with a serious illness. Copyright © 2006 John Wiley & Sons, Ltd.
Accounting for quality in the measurement of hospital performance: evidence from Costa Rica
Authors: Arocena Pablo , García‐Prado Ariadna
Published: December 2006

This paper provides insights into how Costa Rican public hospitals responded to the pressure for increased efficiency and quality introduced by the reforms carried out over the period 1997–2001. To that purpose we compute a generalized output distance function by means of non‐parametric mathematical programming to construct a productivity index, which accounts for productivity changes while controlling for quality of care. Our results show an improvement in hospital performance mainly driven by quality increases. The adoption of management contracts seems to have contributed to such enhancement, more notably for small hospitals. Further, productivity growth is primarily due to technical and scale efficiency change rather than technological change. A number of policy implications are drawn from these results. Copyright © 2006 John Wiley & Sons, Ltd.
Wetlands with controlled drainage and sub‐irrigation systems—modelling of the water balance
Authors: Dietrich Ottfried , Redetzky Michael , Schwärzel Kai
Published: December 2006

Over the past centuries, the agricultural use of wetlands in Central Europe has required interference with the natural wetland water balance. Often this has consisted of drainage measures alone. In low‐precipitation areas, it has also involved the operation of combined drainage and sub‐irrigation systems. Model studies conducted as part of planning processes, or with a view to finding out the impact of changing climate conditions on the water balance of wetlands, must take these facts into account. For this reason, a water balance model has been devised for wetlands whose water balance is governed by water resources management systems. It is based on the WBalMo model system. Special modules were integrated into WBalMo to calculate the water balance of wetland areas (WABI module) and to regulate inflow partitioning within the wetland (REGINF module). When calculating the water balance, the WABI module takes into account precipitation and potential evapotranspiration, groundwater levels below surface, soil types, land‐use classes, inflows via the running water system, and data for target water levels. It provides actual evapotranspiration, discharge into the running water system, and groundwater levels in the area.

The example of the Spreewald, a major wetland area in north‐eastern Germany, was used to design and test the WBalMo Spreewald model. The comparison of measured and calculated water balance parameters of the wetland area confirms the suitability of the model for water balance studies in wetlands with complex water resources management systems. The results reveal the strong influence of water management on the water balance of such areas. The model system has proved to be excellently suited for planning and carrying out water management measures aimed at the sustainable development of wetlands. Furthermore, scenario analyses can be used to assess the impact of global change on the water balance of wetlands. Copyright © 2006 John Wiley & Sons, Ltd.
Carnosic acid from rosemary extracts: a potential chemoprotective agent against aflatoxin B1. An in vitro study
Authors: Costa Stefano , Utan Anelì , Speroni Ester , Cervellati Rinaldo , Piva Gianfranco , Prandini Aldo , Guerra Maria Clelia
Published: December 2006

Since oxidative stress plays an important role in the toxicity mechanism of several mycotoxins such as aflatoxin B1 (AFB1), the use of natural or synthetic free radical scavengers could be a potential chemopreventive strategy.

Carnosic acid (CA) is the major polyphenolic compound present in rosemary plants and it can also be found in sage leaves. Its free radical scavenging properties were tested with two chemical methods. It was found that it has good free radical scavenging capacity at pH 7.4.

This study also found that a 24 h pre‐treatment with 10, 20 and 30 μm CA led to a clear, dose‐dependent protective effect on cell toxicity, reducing cell death induced by a 24 h exposure with 10 μm AFB1, respectively, by 16% (P < 0.05), 26% (P < 0.01) and 63% (P < 0.001). It was also found that a 24 h pre‐treatment with 20 and 30 μm CA achieved a reduction of ROS levels, respectively, of 146% (P < 0.001) and 173% (P < 0.001) in HepG2 cells exposed to 10 μm AFB1 for 8 h. Moreover, in cells pre‐incubated with 30 μm CA for 24 h the concentration of 8‐OH‐deoxyguanine decreased by 57% (P < 0.001) with respect to the cells exposed for 24 h to 10 μm AFB1 alone.

The results obtained with the in vitro and chemical studies support the theory that AFB1 induced oxidative stress plays an important role in the cytotoxic mechanism of this mycotoxin. Furthermore these findings suggest a starting point for developing alimentary strategies in order to counteract the damage caused by AFB1 contamination in feed and food. Copyright © 2006 John Wiley & Sons, Ltd.
Injecting partially digested cartilage fragments into a biphasic scaffold to generate osteochondral composites in a nude mice model
Authors: Liao Chun‐Jen , Lin Yu‐Ju , Chiang Hongsen , Chiang Shu‐Fang , Wang Yao‐Horng , Jiang Ching‐Chuan
Published: December 2006

This study proposed a novel scaffold with heterogeneous morphology that mimics the natural tissue. Its upper part contains a hollow cavity surrounded by a wall of poly(L‐lactic‐co‐glycolic acid) (PLGA) porous membrane for injecting cartilage tissue and cells. An interconnecting porous structure located under the hollow cavity was made of composite materials that combined PLGA and β‐tricalcium phosphate (β‐TCP) to simulate the subchondral bone. Adult pig articular cartilage was cut and sieved into small fragments. The tissue fragments was partially digested by 0.1% collagenase for 0, 2, 4, and 6 h and injected into the hollow cavity of the biphasic scaffold. The biphasic scaffolds were then implanted into the subcutaneous pocket of nude mice for 4 weeks. No tissue bonding or new cartilaginous tissue formation was identified in the cartilage fragment without enzymatic treatment. The cartilage fragments digested with 2 h of collagenase digestion were partially integrated after implantation. The integrative properties of the cartilage fragment depended on the extent of enzymatic digestion. Releasing cells at the tissue surface enhanced confluence and bonding of the cartilage fragment matrix. Complete integration of the cartilage fragments and cartilage remodeling were achieved by digestion of the tissue fragments with 4 h of enzymatic treatment. The neocartilage grew from the upper hollow cavity into the lower PLGA/β‐TCP porous structure, forming an interface similar to that formed between cartilage and subchondral bone. This study combined the osteochondral scaffold and limited cartilage tissues to generate cartilage tissue in vivo intending for repairing full‐thickness articular cartilage defects. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Targeting microspheres and cells to polyethylene glycol‐modified biological surfaces
Authors: Deglau Timothy E. , Johnson Jermaine D. , Villanueva Flordeliza S. , Wagner William R.
Published: December 2006

It has previously been demonstrated that damaged arterial tissue can be acutely modified with protein‐reactive polyethylene glycol (PEG) to block undesirable platelet deposition. This concept might be expanded by employing PEG‐biotin and its strong interaction with avidin for site‐specific targeted delivery. Toward this end, cultured endothelial cells (ECs) were surface modified with PEG‐biotin and the available biotin was quantified with flow cytometry. NeutrAvidin‐coated microspheres and PEG‐biotin modified ECs with NeutrAvidin as a bridging molecule were delivered under arterial shear stress to PEG‐biotin modified ECs on a coverslip as well as scrape‐damaged bovine carotid arteries. After incubation with a 10 mM solution for 1 min, 8 × 107 PEG‐biotin molecules/EC were found and persisted for up to 120 h. Perfused microspheres adhered to NHS‐PEG‐biotin treated bovine carotid arteries with 60 ± 16 microspheres/mm2 versus 11 ± 4 microspheres/mm2 for control arteries (p < 0.015). Similarly, 22 ± 5 targeted ECs/mm2 adhered to NHS‐PEG‐biotin treated bovine carotid arteries versus 6 ± 2 ECs/mm2 for control arteries (p < 0.01). The targeting strategy demonstrated here might ultimately find application for drug delivery, gene therapy, or cell therapy where localization to specific labeled vascular regions is desired following catheter‐based or surgical procedures. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2006
Synthesis and properties of cyclic acetal biomaterials
Authors: Moreau Jennifer L. , Kesselman Dafna , Fisher John P.
Published: December 2006

There is an increasing need to develop new biomaterials as tissue engineering scaffolds. Unfortunately, many of the materials that have been studied for these purposes are polyesters that hydrolytically degrade into acidic products, which may harm the surrounding tissue, and lead to accelerated degradation of the biomaterial. To overcome this disadvantage, a novel class of biomaterials based on a cyclic acetal unit has been created. Specifically, materials based upon the monomer 5‐ethyl‐5‐(hydroxymethyl)‐β,β‐dimethyl‐1,3‐dioxane‐2‐ethanol diacrylate (EHD) is examined. This study investigates the effects of fabrication parameters, including initiator content, volume of diluent, and volume of accelerant, on several properties of EHD networks. Twelve different formulations were fabricated by varying the three parameters in a factorial design. The effects of the fabrication parameters on properties of the EHD networks were examined. Results show that the volume of accelerant most affected the EHD network gelation time, while the volume of diluent most affected the maximum reaction temperature, sol fraction, and degree of swelling. Cell viability on the EHD networks varied between (18 ± 6)% and (57 ± 10)% of the control at 4 h, and between (36 ± 14)% and (140 ± 50)% of the control at 8 h. These results indicate that it is possible to control the properties of the EHD networks by varying the fabrication parameters, and that EHD networks support a viable cell population. © 2006 Wiley Periodicals, Inc. J Biomed Mater, 2007
Inhibitory effect of TNF‐α on the intestinal absorption of galactose
Authors: Amador P. , García‐Herrera J. , Marca M.C. , de la Osada J. , Acín S. , Navarro M.A. , Salvador M.T. , Lostao M.P. , Rodríguez‐Yoldi M.J.
Published: December 2006

Sepsis is a systemic response to infection in which toxins, such as bacterial lipopolysaccharide (LPS), stimulate the production of inflammatory mediators like the cytokine tumor necrosis factor alpha (TNF‐α). Previous studies from our laboratory have revealed that LPS inhibits the intestinal absorption of L‐leucine and D‐fructose in rabbit when it was intravenously administered, and that TNF‐α seems to mediate this effect on amino acid absorption. To extend this work, the present study was designed to evaluate the possible effect of TNF‐α on D‐galactose intestinal absorption, identify the intracellular mechanisms involved and establish whether this cytokine mediates possible LPS effects. Our findings indicate that TNF‐α decreases D‐galactose absorption both in rabbit intestinal tissue preparations and brush‐border membrane vesicles. Western blot analysis revealed reduced amounts of the Na+/glucose cotransporter (SGLT1) protein in the plasma membrane attributable to the cytokine. On the contrary, TNF‐α increased SGLT1 mRNA levels. Specific inhibitors of the secondary messengers PKC, PKA, the MAP kinases p38 MAP, JNK, MEK1/2 as well as the proteasome, diminished the TNF‐α‐evoked inhibitory effect. LPS inhibition of the uptake of the sugar was blocked by a TNF‐α antagonist. In conclusion, TNF‐α inhibits D‐galactose intestinal absorption by decreasing the number of SGLT1 molecules at the enterocyte plasma membrane through a mechanism in which several protein‐like kinases are involved. J. Cell. Biochem. 101: 99–111, 2007. © 2006 Wiley‐Liss, Inc.
Role of PKA in the anti‐Thy‐1 antibody‐induced neurite outgrowth of dorsal root ganglionic neurons
Authors: Chen Chien‐Hsing , Chen Yi‐Jen , Jeng Chung‐Jiuan , Yang Shih‐Hung , Tung Po‐Yuan , Wang Seu‐Mei
Published: December 2006

Thy‐1 is highly expressed in the mammalian nervous system. Our previous study showed that addition of anti‐Thy‐1 antibody to cultured dorsal root ganglionic (DRG) neurons promotes neurite outgrowth. In this study, we identified a novel signaling pathway mediating this event. Treatment with function‐blocking anti‐Thy‐1 antibodies enhanced neurite outgrowth of DRG neurons in terms of total neurite length, longest neurite length, and total neurite branching points. To elucidate the possible signal transduction pathway involved, activation of kinases was evaluated by Western blotting. Transient phosphorylation of protein kinase A (PKA) and mitogen‐activated kinase kinase (MEK) was induced after 15 min of anti‐Thy‐1 antibody treatment. Pretreatment with a PKA inhibitor (PKI) or an MEK inhibitor, PD98059, significantly decreased the neurite outgrowth response triggered by anti‐Thy‐1 antibody, indicating the involvement of both kinases. In addition, anti‐Thy‐1 antibody treatment also induced transient phosphorylation of cyclic AMP‐response element‐binding protein (CREB) and this effect was also blocked by a PKI or PD98059. Furthermore, the fact that PKI abolished anti‐Thy‐1 antibody‐induced MEK phosphorylation showed that PKA acts upstream of the MEK‐CREB cascade. In summary, the PKA‐MEK‐CREB pathway is a new pathway involved in the neurite outgrowth‐promoting effect of anti‐Thy‐1 antibody. J. Cell. Biochem. 101: 566–575, 2007. © 2006 Wiley‐Liss, Inc.
Morphological changes in mouse embryos cryopreserved by different techniques
Authors: Coutinho A.R.S. , Mendes C.M. , Caetano H.V.A. , Nascimento A.B. , Oliveira V.P. , Hernadez‐Blazquez F.J. , Sinhorini I.L. , Visintin J.A. , Assumpção M.E.O.
Published: December 2006

Cryopreservation of mammalian embryos is an important tool for the application of reproductive biotechnologies. Subjective evaluation to determine embryo viability is often used. The determination of the best cryopreservation protocol depends on morphological and molecular analysis of cellular injuries. The main objective of this study was to compare two methods of cryopreservation by assessing morphological alterations of frozen embryos using light, fluorescence, and transmission electron microscope. Fresh (control), slow frozen, and vitrified mouse embryos were composed. To evaluate the viability of the embryos, the cell membrane integrity was assessed using Hoechst33342 and propidium iodide (H/PI) staining. Morphological analyses using hematoxylin and eosin (HE) staining were performed to test different techniques (in situ, paraffin, and historesin) by both light and fluorescence microscopy. Transmission electron microscope was used to detect ultrastructural alterations in Spurr‐ and Araldite‐embedded samples. H/PI staining detected more membrane permeability in the vitrification (69.8%) than in the slow freezing (48.4%) or control (13.8%) groups (P < 0.001). Historesin‐embedded samples showed to be more suitable for morphological analyses because cellular structures were better identified. Nuclear evaluation in historesin sections showed the induction of pycnosis in slow freezing and vitrification groups. Cytoplasm evaluation revealed a condensation and an increase in eosinophilic intensity (indicating apoptosis) in the slow freezing group, and weakly eosinophilic structures and degenerated cells (indicating oncosis) in the vitrification group (P < 0.05). Ultrastructural analyses confirmed HE morphological findings. It was concluded that both cryopreservation techniques resulted in oncosis and apoptosis injuries. However, vitrification caused more severe cellular alterations and reduced embryonic viability compared to slow freezing. Microsc. Res. Tech., 2007. © 2006 Wiley‐Liss, Inc.
Simultaneous diagonal flips in plane triangulations
Authors: Bose Prosenjit , Czyzowicz Jurek , Gao Zhicheng , Morin Pat , Wood David R.
Published: December 2006

Simultaneous diagonal flips in plane triangulations are investigated. It is proved that every triangulation with n ≥ 6 vertices has a simultaneous flip into a 4‐connected triangulation, and that the set of edges to be flipped can be computed in $\cal O$(n) time. It follows that every triangulation has a simultaneous flip into a Hamiltonian triangulation. This result is used to prove that for any two n‐vertex triangulations, there exists a sequence of $\cal O$(logn) simultaneous flips to transform one into the other. Moreover, Ω(log n) simultaneous flips are needed for some pairs of triangulations. The total number of edges flipped in this sequence is $\cal O$(n). The maximum size of a simultaneous flip is then studied. It is proved that every triangulation has a simultaneous flip of at least ${{1}\over{3}}({n}-{2})$ edges. On the other hand, every simultaneous flip has at most n − 2 edges, and there exist triangulations with a maximum simultaneous flip of ${{6}\over{7}}({n}-{2})$ edges. © 2006 Wiley Periodicals, Inc. J Graph Theory 54: 307–330, 2007
New approach for rapid detection of known hemoglobin variants using LC‐MS/MS combined with a peptide database
Authors: Basilico F. , Di Silvestre D. , Sedini S. , Petretto A. , Levreri I. , Melioli G. , Farina C. , Mori F. , Mauri P. L.
Published: December 2006

The identification of hemoglobin (Hb) variants is usually performed by means of different analytical steps and methodologies. Phenotypic methods, such as gel electrophoresis and high performance liquid chromatography, are used to detect the different electrophoretic or chromatographic behaviors of hemoglobin variants in comparison to HbA0 used as a control. These data often need to be combined with mass spectrometry analyses of intact globins and their tryptic peptide mixtures. As an alternative to a ‘step‐by‐step’ procedure, we have developed a ‘single step’ approach for the identification of Hb variants present in biological samples. This is based on the µHPLC‐ESI‐MS/MS analysis of the peptide mixture generated by a tryptic digestion of diluted Hb samples and an in‐house new database containing solely the variant tryptic peptide of known human Hb variants. The experimental results (full MS and MS/MS spectra) are correlated with theoretical mass spectra generated from our in‐house‐built variant peptide database (Hbp) using the SEQUEST algorithm. Simple preparation of samples and an automated identification of the variant peptide are the main characteristics of this approach, making it an attractive method for the detection of Hb variants at the routine clinical level. We have analyzed 16 different samples, each containing a different known variant of hemoglobin. Copyright © 2006 John Wiley & Sons, Ltd.
Human herpesvirus 8: Serovprevalence and correlates in tumor patients from Xinjiang, China
Authors: He Fangping , Wang Xing , He Bin , Feng Zongdi , Lu Xiaomei , Zhang Yaoxin , Zhao Shujun , Lin Renyong , Hui Yan , Bao Yongxing , Zhang Zhaoxia , Wen Hao
Published: December 2006

Human herpesvirus 8 (HHV‐8), also known as Kaposi's sarcoma‐associated herpesvirus, is etiologically associated with Kaposi's sarcoma and other lymphoproliferative diseases. Although HHV‐8 prevalence exhibits considerable variation in different geographic regions and populations, the incidence of Kaposi's sarcoma appear to increase in areas with a high prevalence rate. In this study, an enzyme‐linked immunosorbent assay based on mixed antigens of HHV‐8 ORF73, ORF65, and K8.1 in the antigenic region was established and used to determine viral prevalence estimates and risk factors associated with HHV‐8 infection. Of 482 tumor patients studied, the overall seropositivity of HHV‐8 was 25.5%. Notably, Han people, who were immigrants or descendents of immigrants from inland of China, exhibited 26.4% seropositivity. This is similar to that observed in Uygur people, a local ethnic group with a high prevalence of HHV‐8 infection and incidence of Kaposi's sarcoma. While there was no significant difference in patients with different tumors, HHV‐8 seroprevalence was higher in individuals with malignant diseases. Logistic regression analysis suggests that the age is a risk factor associated with HHV‐8 infection, with prevalence increasing from 12.5% under 20–27.5% above 50. These results suggest that unlike other parts of mainland of China, Xinjiang is an area with a high prevalence of HHV‐8 infection. J. Med. Virol. 79:161–166, 2007. © 2006 Wiley‐Liss, Inc.
Chimeric HIV‐1 and HIV‐2 lentiviral vectors with added safety insurance
Authors: Sachdeva Geetanjali , D'Costa Jenice , Cho Jang E. , Kachapati Kritika , Choudhry Vidita , Arya Suresh K.
Published: December 2006

Lentiviruses are unique in their ability to infect both dividing and non‐dividing cells. This makes the vectors derived from them particularly useful for gene transfer into non‐dividing cells, including stem cells. Lentiviral vectors are becoming the vectors of choice for si/shRNA delivery. The utility of the lentiviral vectors will be enhanced if additional elements of safety are built into their design. One safety concern is the generation of replication competent virus by recombination. We reasoned that HIV‐1 and HIV‐2 hybrid or chimeric lentiviral vectors will have added safety insurance in this regard. This is based on the premise that HIV‐1 and HIV‐2 are dissimilar enough in sequence to curtail recombination, yet similar enough to complement functionally. For hybrid vectors, we found that both HIV‐1 and HIV‐2 transfer vector RNAs could be packaged to equivalent titer by the HIV‐1 packaging machinery. However, HIV‐2 packaging machinery was unable to package HIV‐1 transfer vector as well as it did HIV‐2 transfer vector. This non‐reciprocacity suggested that the requirement for HIV‐2 vectors was more stringent and that for HIV‐1 vectors more promiscuous. When the HIV‐1 transfer vector was packaged with the chimeric packaging construct where the leader‐gag region of HIV‐2 was replaced with that of HIV‐1 packaging construct, the titer of the vector went up. This suggests that at least some of the determinants of specificity for vector assembly reside in the leader‐gag region. Incorporation of central polypurine tract (cPPT) and woodchuck post‐transcriptional enhance element (WPRE) into the HIV‐2 vectors had only modest effect on vector titer. Thus, chimeric lentiviral vectors with added safety features can be designed without compromising transduction efficiency. J. Med. Virol. 79:118–126, 2007. © 2006 Wiley‐Liss, Inc.
Hepatitis C Virus p7 membrane protein quasispecies variability in chronically infected patients treated with interferon and ribavirin, with or without amantadine
Authors: Castelain S. , Bonte D. , Penin F. , François C. , Capron D. , Dedeurwaerder S. , Zawadzki P. , Morel V. , Wychowski C. , Duverlie G.
Published: December 2006

A clinical study was carried out to compare the response rate of two groups of non‐responder (NR) hepatitis C virus (HCV) genotype 1 chronically infected patients treated with interferon and ribavirin, with or without amantadine. The viral load decreased more markedly in the group treated by tritherapy including amantadine, but the response rate at the end of treatment was not significantly different between bitherapy and tritherapy. As amantadine could have an antiviral effect on the ion channel activity of the p7 HCV protein, the p7 quasispecies was characterized by cloning and sequencing. Sequence data were analyzed to determine the pattern and significance of p7 genetic heterogeneity and a possible relationship with therapy. Subtype differences were confirmed between p7 HCV genotypes 1a and 1b, and quasispecies analysis showed a reduction of genetic diversity in subtype 1a, but not 1b, during tritherapy. However, the absence of changes at numerous positions, as well as the conservative changes at other positions, indicated the high conservation of the p7 structure. Residue His‐17, proposed to interact with amantadine, was fully conserved in both subtypes 1a and 1b, independently of amantadine administration. In conclusion, although the analysis of the p7 sequences revealed a selective pressure during therapy, no specific residues appeared to be linked to the effect of amantadine on viral decline. These results suggest that the potential antiviral effect of amantadine might be non‐specific and related to a reduction in endosomal acidification and therefore reduced viral entry of HCV via its pH‐dependent pathway. J. Med. Virol. 79:144–154, 2007. © 2006 Wiley‐Liss, Inc.
Genetic relationship of Torque Teno virus (TTV) between humans and camels in United Arab Emirates (UAE)
Authors: Al‐Moslih Moslih I. , Perkins Heather , Hu Yu‐Wen
Published: December 2006

Torque Teno Virus (TTV) species‐cross infection has been documented. However, the genetic relationship between human and animal TTV remains uncertain. In this study, genotypic characterization of TTV in different Camel specimens from the United Arab Emirates (UAE) was undertaken for comparison with human UAE TTV. A total of 56 specimens: 34 sera, 14 raw, and 8 pasteurized milk samples were tested for TTV. The results showed that the rate of infection was, 38.2% (13/34), 35.7% (5/14), and 100% (8/8), for the samples of sera, raw, and pasteurized milk respectively. The 5′untranslated region (5′UTR) of 23 clones that were generated from PCR products amplified from Camel samples (three sera, three raw, and two pasteurized milk samples) were subjected to sequence analysis. The camel TTV clones were classified as genotype 11 (47.8%), group 5 (43.5%), and SENV‐H or genotype 16 (8.7%) which are among the predominant genotypes found in humans in the UAE. Phylogenetic analysis of representative sequences revealed that the similarity between isolates from camels and humans is 92%–97% for the same genotypes. The data lead to the conclusion that camels and humans share a common source of TTV infection in the UAE. J. Med. Virol. 79:188–191, 2007. © 2006 Wiley‐Liss, Inc.
Local alendronate increases fixation of implants inserted with bone compaction: 12‐week canine study
Authors: Jakobsen Thomas , Kold Søren , Bechtold Joan. E. , Elmengaard Brian , Søballe Kjeld
Published: December 2006

Bone compaction has been shown to increase initial implant fixation. Furthermore, bone compaction creates a peri‐implant zone of autograft that exerts osteoconductive properties. We have previously shown that locally applied bisphosphonate (alendronate) at 4‐week observation can preserve the autograft generated by bone compaction. We now investigate whether the increased amount of autograft, seen at 4 weeks, can increase implant osseointegration and biomechanical fixation. Porous‐coated titanium implants were bilaterally inserted with bone compaction into the proximal part of tibia of 10 dogs. On the right side, local bisphosphonate was injected into the bone cavity prior to bone compaction immediately prior to implant insertion. On the left side, saline was used as control. Observation period was 12 weeks. Locally applied bisphosphonate significantly increased biomechanical implant fixation (approximately twofold), bone‐to‐implant contact (1.2‐fold), and peri‐implant bone volume fraction (2.3‐fold). This study indicates that local alendronate treatment can increase early implant osseointegration and biomechanical fixation of implants inserted by use of bone compaction. Long term effects remain unknown. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:432–441, 2007
Transformation of antimicrobial into bradykinin‐potentiating peptides during peptic hydrolysis of bovine haemoglobin: identification, release kinetics and reaction network of peptides
Authors: Qi Wei , Su Rongxin , He Zhimin
Published: December 2006

The precursor cleavage of the antimicrobial peptide α107–136 into the bradykinin‐potentiating peptide α110–125 during peptic hydrolysis of bovine haemoglobin was investigated by reverse phase high‐performance liquid chromatography coupled with tandem mass spectrometry. The optimal conditions for the preparation of α107–136 and α110–125 were found to be low and high degrees of hydrolysis respectively. A total of six peptides were identified as being involved in the cleavage process. Moreover, the reaction network of these peptides was developed according to the sequence alignment and their release kinetics. The affinity of pepsin towards different peptide bonds of bovine haemoglobin was also compared based on data from the release kinetics of peptides. In addition, some potentially bioactive peptides were predicted by means of sequence analysis and secondary structure calculations. Copyright © 2006 Society of Chemical Industry
Comparison of slow‐release nitrogen yield from organic soil amendments and chemical fertilizers and implications for regeneration of disturbed sites
Authors: Claassen V. P. , Carey J. L.
Published: December 2006

Soil amendments are commonly used to regenerate nutrient levels on disturbed construction sites or mined lands prior to revegetation. Management of nitrogen (N) inputs to the degraded substrates is difficult because the low level of ambient fertility on disturbed substrates requires large total N inputs to sustain revegetative growth, but it also requires low N bioavailability in order to avoid weedy invasion and eutrophication of local watersheds. Commonly available soil amendment materials have a wide variety of N contents and release rates, making specification of appropriate N amendments difficult. We compared N release rates of a variety of organic‐based soil amendments and chemical fertilizers in long‐term aerobic incubation chambers in the lab and at a field revegetation site. The N release rate from these amendments fell into four general groups: (1) rapid N release from soluble chemical fertilizer formulations, (2) longer, controlled N release from chemical‐based, slow‐release formulations, and a two‐phase release pattern (rapid initial phase, slower second phase) from (3) organic‐based blends, as well as (4) unsupplemented municipal yard‐waste composts. The release rates from organic‐based amendments were about three times faster in the 30°C laboratory incubations than in the cool, moist winter growing season at a field site in the Central Valley of California. Relative rates of N release can be compared between amendment materials to help guide selection of N amendments, according to the plant‐growth goals of the revegetation project. Copyright © 2006 John Wiley & Sons, Ltd.
An examination of factors impacting athlete alumni donations to their alma mater: a case study of a U.S. university
Authors: O'Neil Julie , Schenke Marisa
Published: December 2006

It has been suggested that athlete alumni do not give as generously as they could to their alma maters. Athlete alumni may feel they have given enough to their schools by playing sports, and they may feel greater loyalty to their former sports teams than their alma maters. Drawing on social exchange theory, this study investigated whether such attitudes among athlete alumni at a U.S. university were related to lifetime donations. Results indicate:

the quality of alumni's athletic experience and the perception that they have already given to their school by playing sports are predictive of giving amount.

similar to the general alumni donor, the variables of age, income, and geography were also found to be related to giving level.

Universities and colleges may need to develop specialized marketing communications programs to mitigate athlete alumni's perceptions of not needing to donate because they competed for their school. Implications for universities and other nonprofit organizations are offered.

Copyright © 2006 John Wiley & Sons, Ltd.
ABCD position paper on insulin pumps
Authors: Hammond P , Boardman S , Greenwood R
Published: December 2006

Insulin pump therapy is likely to be the most physiological form of subcutaneous insulin administration and has been shown to be of benefit particularly for type 1 diabetic patients who are unable to achieve good control of diabetes without suffering recurrent hypoglycaemic attacks. Whilst the National Institute for Clinical Excellence (NICE) estimated that such therapy should be made available to about 1% of type 1 patients (based mainly on studies done with older pumps and older insulins), experience from mainland Europe, Israel and USA suggests that 10–20% of patients are likely to benefit. Current NICE criteria also make it very difficult for children to qualify for such therapy, as they are unlikely to have tried MDI (multiple‐dose insulin therapy) to justify moving to pump therapy.

The economic impact of the improved quality of life from pump therapy has also not been adequately considered, as some patients are able to return to work, or take fewer days off sick, and children may miss less time at school. There is now substantial new evidence which indicates that the availability of continuous subcutaneous insulin infusion (CSII) should be extended to a much broader group of those with type 1 diabetes than currently fulfil the NICE criteria. Furthermore, there are a number of specific indications for pump therapy where patient numbers are so small that there will never be clinical trial evidence to support the indication, but this should not preclude use of pump therapy in such circumstances where conventional treatments have failed.

This paper summarises the latest evidence regarding the benefits of CSII over MDI and gives recommendations as to the place of CSII in therapy and the service implications. Copyright © 2006 John Wiley & Sons.
Fabrication of polyethylene/graphite nanocomposite from modified expanded graphite
Authors: She Yinhui , Chen Guohua , Wu Dajun
Published: December 2006

A novel process was employed to fabricate a polymer/expanded graphite nanocomposite by modifying the conducting filler expanded graphite (EG) with unsaturated polyester resin (UPR). The modified expanded graphite (MEG) was prepared from EG in which the graphite nanosheets, already present in EG, were wrapped and isolated by the UPR during processing. The as‐prepared MEG was reduced to powder form to improve its dispersion in the matrix. MEG powders were embedded into a high‐density polyethylene (HDPE) matrix via melt‐extrusion in a single‐screw extruder to prepare the conducting composite. The as‐prepared HDPE/EG conducting composite exhibited a low percolation threshold of ∼5.7 wt% due to the high aspect ratio of graphite nanosheets. Mechanical properties such as the tensile and impact strength were also studied. Scanning electron microscopy was used to characterize the microstructure of EG, MEG powder and the resulting nanocomposites. Copyright © 2006 Society of Chemical Industry
Fe3+ immobilized metal affinity chromatography with silica monolithic capillary column for phosphoproteome analysis
Authors: Feng Shun , Pan Chensong , Jiang Xiaogang , Xu Songyu , Zhou Houjiang , Ye Mingliang , Zou Hanfa
Published: December 2006

Immobilized metal affinity chromatography (IMAC) is a commonly used technique for phosphoproteome analysis due to its high affinity for adsorption of phosphopeptides. Miniaturization of IMAC column is essential for the analysis of a small amount of sample. Nanoscale IMAC column was prepared by chemical modification of silica monolith with iminodiacetic acid (IDA) followed by the immobilization of Fe3+ ion inside the capillary. It was demonstrated that Fe3+‐IDA silica monolithic IMAC capillary column could specifically capture the phosphopeptides from tryptic digest of α‐casein with analysis by MALDI‐TOF MS. The silica monolithic IMAC capillary column was manually coupled with nanoflow RPLC/nanospray ESI mass spectrometer (μRPLC–nanoESI MS) for phosphoproteome analysis. The system was validated by analysis of standard phosphoproteins and then it was applied to the analysis of protein phosphorylation in mouse liver lysate. Besides MS/MS spectra, MS/MS/MS spectra were also collected for neutral loss peak. After database search and manual validation with conservative criteria, 29 singly phosphorylated peptides were identified by analyzing a tryptic digest of only 12 μg mouse liver lysate. The results demonstrated that the silica monolithic IMAC capillary column coupled with μRPLC‐nanoESI MS was very suitable for the phosphoproteome analysis of minute sample.
Payne effect in silica‐filled styrene–butadiene rubber: Influence of surface treatment
Authors: Ramier J. , Gauthier C. , Chazeau L. , Stelandre L. , Guy L.
Published: December 2006

The nonlinear effect at small strains (Payne effect) has been investigated in the case of silica‐filled styrene‐butadiene rubber. The originality of this study lies in the careful preparation of samples in order to fix all parameters except one, that is, the modification of the silica surface by grafting silane (introduced at different concentrations) via reactive mixing. The organosilane can be either a coupling or a covering surface treatment with an octyl alkyl chain. A careful morphological investigation has been performed prior to mechanical characterization and silica dispersion was found to be the same whatever the type and the amount of silane. The increasing amount of covering agents was found to reduce the amplitude of the Payne effect. A similar decrease is observed for low coupling agent concentration. At higher concentrations, the evolution turns through an increase due to the contribution of the covalent bonds between the matrix and the silica acting as additional crosslinking. The discussion of the initial modulus was done in the frame of both the filler–filler and filler–polymer models. It is unfortunately not possible to distinguish both scenarios, because filler–filler and filler–matrix interactions are modified in the same manner by the grafting covering agent. On the other hand, the reversible decrease of the modulus versus strain (Payne effect) is interpreted in terms of debonding of the polymeric chains from the filler surface. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 286–298, 2007