bluuebunny/crossref_metadata_2025 huggingface dataset:
A model for integrating wildlife science and agri‐environmental policy in the conservation of declining species
Authors: Perlut Noah G. , Strong Allan M. , Alexander Toby J.
Published: July 2011

We examined a case study where a successful wildlife‐friendly model for intensively managed hayland was developed from field data and implemented locally as policy by a federal agency. Farmers were ensured a first hay‐harvest with high protein content; after a 65‐day delay (compared to the normal 35–40‐day cutting cycle) farmers took a second harvest of greater quantity but decreased quality. Farmers were paid $247–333/ha in 2008–2010 to offset costs associated with the decreased nutritional content caused by the approximately 25‐day second harvest delay. Bobolink (Dolichonyx oryzivorus) reproductive rates improved from 0.0 to 2.8 fledglings per female per year. Creation and implementation of this policy required communication among scientists, federal agricultural agencies, farmers, and state and federal fish and wildlife departments. Data collection, analyses, and communication processes served as an effective global model for practitioners to apply to other agricultural products and taxa. © 2011 The Wildlife Society.
Polyalkylenehydroxybenzoates (PAHBs): Biorenewable Aromatic/Aliphatic Polyesters from Lignin
Authors: Mialon Laurent , Vanderhenst Rob , Pemba Alexander G. , Miller Stephen A.
Published: July 2011

Polyalkylenehydroxybenzoates (PAHBs) are a new class of thermoplastic, biorenewable aromatic/aliphatic polyester having the general formula H‐[O‐(CH2)n‐O‐4‐(3‐X, 5‐Y‐C6H2)‐CO]z‐OH. These are synthesized from the lignin‐derived aromatics 4‐hydroxybenzoic acid (X = Y = H), vanillic acid (X = OMe; Y = H), and syringic acid (X = Y = OMe). Alkylation of these with several chloroalkanols affords hydroxy‐acid monomers suitable for polyesterification under dynamic vacuum between 150 and 250 °C with 1 mol% Sb2O3 as catalyst. Thus, polyalkylene 4‐hydroxybenzoates, polyalkylene vanillates, and polyalkylene syringates are prepared, characterized, and subjected to thermal property comparisons by differential scanning calorimetry and thermogravimetric analysis.

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Kumada Catalyst‐Transfer Polycondensation: Mechanism, Opportunities, and Challenges
Authors: Kiriy Anton , Senkovskyy Volodymyr , Sommer Michael
Published: July 2011

Kumada catalyst‐transfer polycondensation (KCTP) is a new but rapidly developing method with great potential for the preparation of well‐defined conjugated polymers (CPs). The recently discovered chain‐growth mechanism is unique among the various transition metal‐catalyzed polycondensations, and has thus attracted much attention among researchers. Most progress is found in the areas of mechanism and external initiation via new initiators, but also the number of monomers other than thiophene that can be polymerized is steadily increasing. Accordingly, the variety of CP chain architectures is increasing as well, and a considerable contribution of KCTP toward more efficient materials can be expected in the future. This review critically focuses on very recent progress in the synthesis of CPs and the mechanism of KCTP, and is finally aimed at providing a comprehensive picture of this exciting polymerization method.

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End‐to‐End Distances in Four‐Junction Polymers
Authors: Kosmas Marios , Forzaglia Thomas , Bishop Marvin
Published: July 2011

The various end‐to‐end distances of four‐junction polymers are investigated. The sizes of the different kinds of equal length branches and the backbone of two different polymers, with either nine or eleven branches, are estimated by means of both renormalization‐group and MC calculations. The comparisons of first‐order ε = 4 − d predictions with the MC results are satisfactory. The same trends are present in both techniques. The excluded‐volume interactions from additional branches further expand the various parts of the chains so that internal branches are larger than external ones. The branch ratios in the eleven‐branch case are expanded even more than the corresponding ratios of the nine‐branch polymer.

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Predicting the Limit of Control in the ATRP Process: Results from Kinetic Simulations
Authors: Bergenudd Helena , Jonsson Mats , Malmström Eva
Published: July 2011

Kinetic simulations are reported, where the ATRP equilibrium constant KATRP is varied and the rates and degree of control in different ATRP systems are evaluated. The apparent rate constant kapp increases with increasing KATRP, but a maximum is reached. The limit of control is passed before the maximum, i.e. when KATRP is increased further, apparent first‐order kinetics and well‐controlled molecular weights will no longer be obtained. The equilibrium constant at which the limit of control is reached varies linearly with the propagation rate constant. This enables the design of well controlled ATRP systems. The influence of the conversion and chain length dependence of the termination rate constant on the simulation results is discussed.

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On the Universality and Contributions of Multiple Criteria Decision Making: A Systems‐Based Approach
Authors: Haimes Yacov Y.
Published: July 2011

This paper highlights the omnipresence of the philosophy, theory, methodology and deployment of multiple criteria decision making (MCDM) in essentially every aspect of our lives. It also highlights the specific philosophical, theoretical, methodological, and deployment perspectives that MCDM has influenced, and how MCDM has thus shaped the decision‐making process. The following five themes demonstrate the universality of multiple objectives and their impact on the complex decision‐making process: (i) the centrality of the states of the system in MCDM; (ii) the centrality of trade‐offs in MCDM and the !‐constraint method; (iii) the centrality of the time frame in MCDM; (iv) the centrality of risk and uncertainty in MCDM; and (v) the contributions of MCDM to decision analysis. An epilogue concludes the paper. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis of DNA adducts in human samples: Acrolein‐derived exocyclic DNA adducts as an example
Authors: Chen Hauh‐Jyun Candy
Published: July 2011

Acrolein is an environmental pollutant that is also derived endogenously through lipid peroxidation and protein degradation. The reaction of acrolein with 2′‐deoxyguanosine produces exocyclic 1,N2‐propano‐2′‐deoxyguanosine (AdG) adducts, mutagenic lesions that play important roles in multistage carcinogenesis processes. Accurate quantification of acrolein‐derived DNA adducts is a critical step toward elucidating the mode of action of acrolein carcinogenicity. Exposure of humans to acrolein can occur through the smoking of tobacco and the dietary consumption of oxidized polyunsaturated fatty acids. This review describes the use of 32P‐postlabeling‐ and MS‐based methods for the analyses of acrolein‐derived DNA adducts in humans as well as present trends toward improving the sensitivity, specificity, and accuracy of the quantification of trace amounts of DNA adducts in DNA of limited availability.
Heteromorphic sex chromosomes: Navigating meiosis without a homologous partner
Authors: Checchi Paula M. , Engebrecht JoAnne
Published: July 2011

Accurate chromosome segregation during meiosis relies on homology between the maternal and paternal chromosomes. Yet by definition, sex chromosomes of the heterogametic sex lack a homologous partner. Recent studies in a number of systems have shed light on the unique meiotic behavior of heteromorphic sex chromosomes, and highlight both the commonalities and differences in divergent species. During meiotic prophase, the homology‐dependent processes of pairing, synapsis, and recombination have been modified in many different ways to ensure segregation of heteromorphic sex chromosomes at the first meiotic division. Additionally, an almost universal feature of heteromorphic sex chromosomes during meiosis is transcriptional silencing, or meiotic sex chromosome inactivation, an essential process proposed to prevent expression of genes deleterious to meiosis in the heterogametic sex as well as to shield unpaired sex chromosomes from recognition by meiotic checkpoints. Comparative analyses of the meiotic behavior of sex chromosomes in nematodes, mammals, and birds reveal important conserved features as well as provide insight into sex chromosome evolution. Mol. Reprod. Dev. 78:623–632, 2011. © 2011 Wiley‐Liss, Inc.
Protective effect of sodium ascorbate on efficacy of intramuscular transplantation of autologous muscle‐derived cells
Authors: Bartoszuk‐Bruzzone Urszula , Burdzińska Anna , Orzechowski Arkadiusz , Kłos Zdzisław
Published: July 2011

Introduction:

The possible reason for elimination of myogenic cells after transplantation is inflammation at the injection site associated with oxidative stress. The aim of this study was to determine whether preconditioning of muscle‐derived cells with an antioxidant, sodium ascorbate, can influence the fate of transplanted cells.

Methods:

Autologous transplantation of muscle‐derived cells was performed in rabbits. Isolated cells were identified, lipofected with β‐galactosidase, preincubated or not with sodium ascorbate, and injected intramuscularly.

Results:

Two weeks after autologous transplantation in the edge of a previous muscle defect, donor cells formed multinucleated young myotubes. Pretreatment of cells with sodium ascorbate before injection resulted in a significant increase of donor cells at the injection site 2 weeks after transfer.

Conclusions:

These results show that: (1) preincubation with antioxidant can increase the efficacy of myogenic cell transplantation; and (2) oxidative stress may play a role in elimination of cells after autologous transplantation. Muscle Nerve 45:32–38, 2012
Manganese kinetics demonstrated double contrast in acute but not in chronic infarction in a mouse model of myocardial occlusion reperfusion
Authors: Delattre Bénédicte M. A. , Braunersreuther Vincent , Gardier Stéphany , Hyacinthe Jean‐Noël , Crowe Lindsey A. , Mach François , Vallée Jean‐Paul
Published: July 2011

Manganese (Mn2+) is considered as a specific MRI contrast agent that enters viable cardiomyocytes through calcium pathways. Compared to extracellular gadolinium based contrast agents, it has the potential to assess cell viability. To date, only information from the washout phase after recirculation has been used for the detection and characterization of myocardial infarct. This study showed for the first time that in a mouse model of coronary occlusion‐reperfusion, Mn2+ wash‐in kinetics are different at 24 h after surgery (acute infarction) than at eight days after surgery (chronic infarction). A fast but transient entry of Mn2+ into the acute infarct area led to a double contrast between infarct and remote areas, whereas entry of Mn2+ into the chronic infarct area remained reduced compared to remote regions during both wash‐in and washout phases. The main hypothesis is that extracellular space is largely enhanced in acute infarction due to cell membrane rupture and interstitial edema, whereas scar tissue is densely composed of collagen fibers that reduce the distribution volume of free Mn2+ ions. In addition to its ability to accurately depict the infarct area during the redistribution phase, Mn2+ is also able to discriminate acute versus chronic injury by the observation of double‐contrast kinetics in a mouse model of ischemia reperfusion. Copyright © 2011 John Wiley & Sons, Ltd.
In vivo metabolic profiling of glioma‐initiating cells using proton magnetic resonance spectroscopy at 14.1 Tesla
Authors: Mlynárik Vladimír , Cudalbu Cristina , Clément Virginie , Marino Denis , Radovanovic Ivan , Gruetter Rolf
Published: July 2011

In the last decade, evidence has emerged indicating that the growth of a vast majority of tumors including gliomas is sustained by a subpopulation of cancer cells with stem cell properties called cancer initiating cells. These cells are able to initiate and propagate tumors and constitute only a fraction of all tumor cells. In the present study, we showed that intracerebral injection of cultured glioma‐initiating cells into nude mice produced fast growing tumors showing necrosis and gadolinium enhancement in MR images, whereas gliomas produced by injecting freshly purified glioma‐initiating cells grew slowly and showed no necrosis and very little gadolinium enhancement. Using proton localized spectroscopy at 14.1 Tesla, decreasing trends of N‐acetylaspartate, glutamate and glucose concentrations and an increasing trend of glycine concentration were observed near the injection site after injecting cultured glioma‐initiating cells. In contrast to the spectra of tumors grown from fresh cells, those from cultured cells showed intense peaks of lipids, increased absolute concentrations of glycine and choline‐containing compounds, and decreased concentrations of glutamine, taurine and total creatine, when compared with a contralateral non‐tumor‐bearing brain tissue. A decrease in concentrations of N‐acetylaspartate and γ‐aminobutyrate was found in both tumor phenotypes after solid tumor formation. Further investigation is needed to determine the cause of the dissimilarities between the tumors grown from cultured glioma‐initiating cells and those from freshly purified glioma‐initiating cells, both derived from human glioblastomas. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient code gateway for RFID seamless applications
Authors: Ma Yi‐Wei , Chen Jiann‐Liang , Kuo Sy‐Yen , Hsieh Wen‐Kuei , Huang Yueh‐Min
Published: July 2011

This work presents novel design schemes for the code gateway between the electronic product code (EPC) and ubiquitous ID (uID) for radio‐frequency identification (RFID) technology solutions. Interfaces of the gateway that are implemented include the system interface, EPC discovery service (DS), uID DS, and the certification card mechanism. Five major operations are also developed, including inquiry of EPC DS, uID DS, code diversion mechanism, PIN‐IC interface, and code conversion mechanism. Simulation results indicate that in addition to providing codes diversion and conversion, the proposed code gateway achieves low‐order conformity between these two systems. Moreover, the implemented EPC DS and uID DS interface provide immediate commodity news and exchange of historical information. In addition to delivering inevitable processing efficiency, the integrated system between these two systems significantly improves ubiquitous computing environments. Copyright © 2011 John Wiley & Sons, Ltd.
Antidepressants and the risk of sudden cardiac death and ventricular arrhythmia
Authors: Leonard Charles E. , Bilker Warren B. , Newcomb Craig , Kimmel Stephen E. , Hennessy Sean
Published: July 2011

Purpose

To examine the association between exposure to antidepressants and emergency department or inpatient admission for sudden cardiac death and ventricular arrhythmia (SD/VA), and to examine the impact of dose and cytochrome P‐450 inhibition.

Methods

A cohort study was conducted using 1999–2003 Medicaid claims data from beneficiaries of five large states, supplemented with Medicare claims for dually eligible individuals. Exposures were prescription claims for antidepressants of interest or a reference antidepressant. Outcomes were incident first‐listed emergency department or principal inpatient diagnoses indicative of SD/VA originating in the outpatient setting, an outcome previously found to have a positive predictive value of 85%.

Results

In 1.3 million person‐years of antidepressant exposure, we identified 4222 SD/VA outcomes for a rate of 3.3/1000 person‐years (95%CI, 3.2–3.4). Compared with paroxetine (a referent with a putatively favorable cardiovascular risk profile), adjusted hazard ratios (HRs) were 0.80 (0.67–0.95) for bupropion, 1.24 (0.93–1.65) for doxepin, 0.79 (0.55–1.15) for lithium, and 1.26 (1.11–1.42) for mirtazapine. HRs for amitriptyline, citalopram, fluoxetine, nefazodone, nortriptyline, sertraline, trazodone, and venlafaxine were near unity. For antidepressants having nonnull risks (bupropion and mirtazapine), we observed no relationship with antidepressant dose and some relationships with concomitant cytochrome P‐450 inhibition.

Conclusions

Of antidepressants studied, only mirtazapine had a statistically significantly greater SD/VA risk versus paroxetine. However, baseline differences between these users suggest that this finding may be attributable to residual confounding. Eleven other antidepressants had SD/VA risks no greater than that of paroxetine, thereby providing reassurance regarding the comparative cardiovascular safety of antidepressants. Copyright © 2011 John Wiley & Sons, Ltd.
Variations and determinants of antibiotic consumption in Hungarian adult intensive care units
Authors: Benkő Ria , Matuz Mária , Pető Zoltán , Bogár Lajos , Viola Réka , Doró Péter , Soós Gyöngyvér , Hajdú Edit
Published: July 2011

Purpose

The aim of this work was to study the use of systemic antibacterials and its possible determinants in Hungarian intensive care units (ICUs).

Methods

Hospital pharmacy. departments provided package level dispensing data for their corresponding ICU (2006). Data were converted into defined daily doses (DDDs) and expressed as DDD per 100 patient‐days and DDD per 100 admissions. Antibiotics were ranked by volume of DDDs, and the agents responsible for 90% of total use (DU90%) were noted. To explore differences and relationships between antibiotic use and antibiotic policy elements/ICU characteristics, the analysis of variances or the Pearson correlation analysis was performed.

Results

Valid data were obtained for 44 ICUs. Antibiotic use varied widely (from 27.9 to 167.8 DDD per 100 patient‐days and from 104.7 to 1784.6 DDD per 100 admissions). In total, 11–34 different antibacterials per ICUs were used, of which, 5–15 were in the DU90% segment. The proportional use of parenteral agents ranged from 46.2 to 98.3%. The mean of overall antibiotic use was highest for penicillins with beta‐lactamase inhibitors, followed by quinolones and third‐generation cephalosporins. Of the studied factors, only the ICU category (i.e., level of care) showed significant association with total antibacterial use.

Conclusions

The striking differences in total antibiotic use and the extensive use of the oral agents in some ICUs may indicate room for improvement. As none of the antibiotic policy elements were accompanied by lower antibiotic use in the pooled analysis, it suggests that—beside the ICU category—other unrevealed factors determine antibiotic use. Copyright © 2011 John Wiley & Sons, Ltd.
Tailoring toughness of injection molded bar of polypropylene random copolymer through processing melt temperature
Authors: Luo Feng , Wang Ke , Wang Jinwen , Deng Hua , Zhang Qin , Chen Feng , Fu Qiang , Na Bing
Published: July 2011

In this study, a facile route to realize the superior toughness of injection molded polypropylene random copolymer (PPR) is reported. The toughness of PPR is increased about twofold when the processing melt temperature increases from 180 to 250 °C. Systematic and detailed structural characterizations have been carried out to establish the structure–property relationships by using polarized light microscopy, scanning electron microscopy, infrared microscopy and dynamic mechanical analysis. It is found that increasing the melt temperature is beneficial for the coalescence of rubbery domains and enhanced molecular mobility which are mainly responsible for the improvement in toughness. Other factors, such as molecular orientation, crystallinity and so on, seem to have little effect. The vital role of enhanced molecular mobility in improving toughness is further demonstrated by the annealing of injection molded samples at elevated temperature, i.e. 110 °C. Copyright © 2011 Society of Chemical Industry
Dielectric relaxation phenomena and dynamics in polyoxymethylene/polyurethane/alumina hybrid nanocomposites
Authors: Psarras Georgios C , Siengchin Suchart , Karahaliou Panagiota K , Georga Stavroula N , Krontiras Christoforos A , Karger‐Kocsis József
Published: July 2011

Ternary hybrid composites composed of polyoxymethylene (POM), polyurethane (PU) and boehmite alumina nanoparticles were produced by melt blending with and without latex pre‐compounding. PU latex pre‐compounding was employed for the fine dispersion of both the PU and alumina particles within the POM matrix. In this study the electrical properties of the POM/PU/boehmite alumina nanocomposites were examined by means of broadband dielectric spectroscopy over a wide temperature (−100 to 150 °C) and frequency (10−1 to 106 Hz) range. Data were analysed by means of the electric modulus formalism. The recorded relaxations include contributions from both polymers and the inorganic reinforcing phase. In the ternary hybrid systems five distinct relaxation processes were detected. Relaxations were assigned and interpreted by considering the morphology of the corresponding composite. In particular, they were attributed to the γ‐mode of POM and/or of PU, the α‐mode of PU, the α‐mode of POM and to the interfacial polarization process. Finally, the dynamics of all the recorded processes are examined and discussed. Copyright © 2011 Society of Chemical Industry
Evaluation of protein expression in bovine bronchoalveolar fluid following challenge with Mannheimia haemolytica
Authors: Boehmer Jamie L. , DeGrasse Jeffrey A. , Lancaster Vicki A. , McFarland Melinda A. , Callahan John H. , Ward Jeffrey L.
Published: July 2011

Proteomics analysis of bovine bronchoalveolar fluid (BAF) following induction of pneumonia with Mannheimia haemolytica using nanoflow liquid chromatography coupled with tandem mass spectrometry (nanoLC‐MS/MS) resulted in the identification of 88 unique proteins. Proteins detected in BAF included antimicrobial peptides (AMPs), complement factors, acute‐phase proteins, protease inhibitors, and proteins involved in oxidation–reduction. Notwithstanding biological variation, differences in relative protein abundance, determined using normalized peptide counts, were detected for select proteins in BAF from genuinely infected versus sham‐infected animals. To demonstrate the applicability of using normalized peptide counts to assess protein expression trends, LC‐MS/MS data for the acute‐phase protein haptoglobin (HPT) were compared with ELISA data, and statistical evaluation of the relationship between the data revealed a strong measure of association. Differences were detected between sham‐ and genuinely infected animals for haptoglobin, as well as the AMPs cathelicidin‐1 and cathelicidin‐4, and inter‐α‐trypsin inhibitor heavy chain‐4, a fairly novel protein involved in the acute phase response. Though the small sample size limited the scope of the inferences, the results indicate the likely importance of AMPs and acute‐phase proteins during respiratory infection, and provide additional information regarding potential mechanisms involved in the bovine mucosal barrier defense.
Dietary phytoestrogen supplementation induces sex differences in the myocardial protein pattern of mice: A comparative proteomics study
Authors: Schwab Karima , Neumann Boris , Vignon‐Zellweger Nicolas , Fischer Andreas , Stein Robert , Jungblut Peter R. , Scheler Christian , Theuring Franz
Published: July 2011

Elevated cardiovascular risk in postmenopausal women and beneficial actions of estrogen replacement in animal models have been related to protective effects of estrogens. However, randomized trials of hormone replacement therapy with synthetic estrogens in humans failed confirmation and phytoestrogens, natural plant hormones with agonistic properties for estrogen receptors, could represent potential alternatives. The aim of the present study is to characterize an animal model for alternative hormone replacement with genistein as a natural estrogenic compound. We performed a 2‐DE/ESI‐LC‐MS approach in order to identify protein species varying with genistein receipt and sex in their relative abundance in the healthy murine heart (http://www.mpiib‐berlin.mpg.de/2D‐PAGE). Oral genistein treatment revealed a substantial effect on the relative abundance of both estrogen receptors. Several enzymes of the fatty acid metabolism and their transcriptional regulators varied differentially in male and in female animals, at the transcript and/or the protein species level. Increased levels of enzyme species involved in the oxidative phosphorylation and generation of ROS were accompanied by decreased amounts of antioxidants in male mice receiving genistein compared with control males, which have been previously associated with various pathological conditions. Exposure of female animals to genistein provoked an increased abundance of two species of LIM domain‐binding protein and one species of desmin. These proteins have been associated with cardiac hypertrophy and our data warrant caution for the use of them as molecular markers, since the animals did not exhibit any histological signs of cardiac hypertrophy.
A reference map of the membrane proteome of Enterococcus faecalis
Authors: Maddalo Gianluca , Chovanec Peter , Stenberg‐Bruzell Filippa , Nielsen Hailyn V. , Jensen‐Seaman Michael I. , Ilag Leopold L. , Kline Kimberly A. , Daley Daniel O.
Published: July 2011

Enterococcus faecalis is a gram‐positive bacterium that is part of the indigenous microbiotica of humans and animals as well as an opportunistic pathogen. In this study, we have fractionated the membrane proteome of E. faecalis and identified many of its constituents by mass spectrometry. We present blue native‐/SDS‐PAGE reference maps that contain 102 proteins. These proteins are important for cellular homeostasis, virulence, and antibiotic intervention. Intriguingly, many proteins with no known function were also identified, indicating that there are substantial gaps in the knowledge of this organism's biology. On a more limited scale, we also provide insight into the composition of membrane protein complexes. This study is a first step toward elucidating the membrane proteome of E. faecalis, which is critical for a better understanding of how this bacterium interacts with a host and with the extracellular milieu.
Functional analysis of the sortase YhcS in Bacillus subtilis
Authors: Fasehee Hamidreza , Westers Helga , Bolhuis Albert , Antelmann Haike , Hecker Michael , Quax Wim J. , Mirlohi Agha F. , van Dijl Jan Maareten , Ahmadian Gholamreza
Published: July 2011

Sortases of Gram‐positive bacteria catalyze the covalent C‐terminal anchoring of proteins to the cell wall. Bacillus subtilis, a well‐known host organism for protein production, contains two putative sortases named YhcS and YwpE. The present studies were aimed at investigating the possible sortase function of these proteins in B. subtilis. Proteomics analyses revealed that sortase‐mutant cells released elevated levels of the putative sortase substrate YfkN into the culture medium upon phosphate starvation. The results indicate that YfkN required sortase activity of YhcS for retention in the cell wall. To analyze sortase function in more detail, we focused attention on the potential sortase substrate YhcR, which is co‐expressed with the sortase YhcS. Our results showed that the sortase recognition and cell‐wall‐anchoring motif of YhcR is functional when fused to the Bacillus pumilus chitinase ChiS, a readily detectable reporter protein that is normally secreted. The ChiS fusion protein is displayed at the cell wall surface when YhcS is co‐expressed. In the absence of YhcS, or when no cell‐wall‐anchoring motif is fused to ChiS, the ChiS accumulates predominately in the culture medium. Taken together, these novel findings show that B. subtilis has a functional sortase for anchoring proteins to the cell wall.
Controlled surface‐initiated ring‐opening polymerization of L‐lactide from risedronate‐anchored hydroxyapatite nanocrystals: Novel synthesis of biodegradable hydroxyapatite/poly(L‐lactide) nanocomposites
Authors: Chen Jie , Chen Wei , Deng Chao , Meng Fenghua , Zhong Zhiyuan
Published: July 2011

Risedronate‐anchored hydroxyapatite (HA‐RIS) nanocrystals were prepared with 4.1 wt % RIS and used for controlled surface‐initiated ring‐opening polymerization (ROP) of L‐lactide (L‐LA). The strong adsorption of RIS to HA surface not only led to enhanced dispersion of HA nanocrystals in water as well as in organic solvents but also provided alkanol groups as active initiating species for ROP of L‐LA. HA‐RIS was characterized by thermogravimetric analysis, dynamic light scattering, 1H NMR, Fourier transform infrared spectrometer, and X‐ray diffraction. The graft polymerization of L‐LA onto HA‐RIS took place smoothly in the presence of stannous octoate in toluene at 120 °C, resulting in HA/poly(L‐LA) nanocomposites with high yields of 85–90% and high poly(L‐LA) contents of up to 97.5 wt %. Notably, differential scanning calorimetry measurements revealed that the poly(L‐LA) in HA/poly(L‐LA) nanocomposites exhibited considerably higher melting temperatures (Tm = 173.3−178.1 °C) and higher degrees of crystallinity (Xc = 41.0−43.1%) as compared to poly(L‐LA) homopolymer (Tm = 168.5 °C, Xc =25.7%). In addition, our initial results showed that these HA/poly(L‐LA) nanocomposites could readily be electrospun into porous matrices. This study presented a novel and controlled synthetic strategy to HA/RIS/poly(L‐LA) nanocomposites that are promising for orthopedic applications as well as for bone tissue engineering. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
New moderate bandgap polymers containing alkoxysubstituted‐benzo[c][1,2,5]thiadiazole and thiophene‐based units
Authors: Lim Zheng Bang , Xue Bofei , Bomma Swarnalatha , Li Hairong , Sun Shuangyong , Lam Yeng Ming , Belcher Warwick J. , Dastoor Paul C. , Grimsdale Andrew C.
Published: July 2011

Alkoxysubstituted benzo[c][1,2,5]thiadiazole electron accepting units were prepared and copolymerized with various thiophene‐based electron donating monomers to produce new low bandgap polymers P1–4. The materials showed broad absorption in the range from 300 to 700 nm with bandgaps below 2 eV in solution. Efficiencies of over 1% were obtained from photovoltaic cells using P4 with PCBM as acceptor. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Co‐administration of piperine and docetaxel results in improved anti‐tumor efficacy via inhibition of CYP3A4 activity
Authors: Makhov Peter , Golovine Konstantin , Canter Daniel , Kutikov Alexander , Simhan Jay , Corlew Melany M. , Uzzo Robert G. , Kolenko Vladimir M.
Published: July 2011

BACKGROUND

Docetaxel is the mainline treatment approved by the FDA for castration‐resistant prostate cancer (CRPC) yet its administration only increases median survival by 2–4 months. Docetaxel is metabolized in the liver by hepatic CYP3A4 activity. Piperine, a major plant alkaloid/amide, has been shown to inhibit the CYP3A4 enzymatic activity in a cell‐free system. Thus, we investigated whether the co‐administration of piperine and docetaxel could increase docetaxel's pharmacokinetic activity in vitro and in vivo.

METHODS

Liver CYP3A4 enzymatic activity was measured by fluorescence. In vivo docetaxel pharmacokinetic activity was analyzed by liquid chromatography. An in vivo xenograft model of human CRPC was utilized to assess the anti‐tumor effect of docetaxel when co‐administered with piperine.

RESULTS

Inhibition of hepatic CYP3A4 activity resulted in an increased area under the curve, half‐life and maximum plasma concentration of docetaxel when compared to docetaxel alone administration. The synergistic administration of piperine and docetaxel significantly improved the anti‐tumor efficacy of docetaxel in a xenograft model of human CRPC.

CONCLUSIONS

Docetaxel is one of the most widely used cytotoxic chemotherapeutic agents and is currently the mainstay treatment for metastatic CRPC. Dietary constituents are important agents modifying drug metabolism and transport. In our studies, dietary consumption of piperine increases the therapeutic efficacy of docetaxel in a xenograft model without inducing more adverse effects on the treated mice. Prostate 72:661–667, 2012. © 2011 Wiley Periodicals, Inc.
Monitoring the mechanical integrity of heat exchangers
Authors: Utne I. B. , Brurok T. , Larsen S.
Published: July 2011

Monitoring the mechanical integrity (MI) of offshore oil and gas facilities is important. It enables early fault detection of emerging failure conditions and allows more time for planning and preparing remedial actions, which reduces revenue losses resulting from unnecessary and poorly coordinated maintenance actions. Static equipment, such as heat exchangers, constitutes crucial parts of offshore processing facilities. Heat exchangers are challenging to maintain, especially in ageing facilities, and major maintenance problems are the result of (a) poor designs, (b) poor utilization of process information, (c) poor interpretation of results, and (d) poor development and management of high‐quality maintenance and MI programs. This article addresses the most important technological, human and organizational challenges concerning monitoring of MI of shell and tube heat exchangers, and discusses recommendations for future improvements. A good MI program benefits the operation and maintenance of heat exchangers, and will lead to improved safety and reduced costs. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
New technology for inspecting critical in‐plant piping systems
Authors: Widrig James R.
Published: July 2011

Inspection and fitness‐for‐service (FFS) of critical in‐plant piping systems remains an ongoing concern for the chemical industry. Recent failures in the US indicate that there is a present and severe risk in piping systems. Historically, unpiggable in‐plant piping can now be inspected with advanced smart pigging technology for complete ultrasonic inspection. High‐resolution inspection data is analyzed to identify the locations and degree of corrosion and piping deformations. This article discusses current industry experience with the inspection and assessment of in‐plant piping systems using advanced smart pigging technology.

Utilizing more advanced inline inspection and assessment technology helps operators reduce inspection costs associated with difficult‐to‐inspect pipelines and piping systems; reduce maintenance costs by more accurately pinpointing anomalies and assessing FFS conditions; and accurately determine the actual conditions for lines previously deemed unpiggable. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
Absorption, translocation and metabolism of metamitron in Chenopodium album
Authors: Aper Jonas , Mechant Els , Rubin Baruch , Heyerick Arne , Callebaut Gert , Mangelinckx Sven , Deforce Dieter , De Kimpe Norbert , Bulcke Robert , Reheul Dirk
Published: July 2011

BACKGROUND: In recent years, common lambsquarters (Chenopodium album L.) populations from sugar beet fields in different European countries have responded as resistant to the as‐triazinone metamitron. The populations have been found to have the same D1 point mutation as known for atrazine‐resistant biotypes (Ser264 to Gly). However, pot experiments revealed that metamitron resistance is not as clear‐cut as observed with triazine resistance in the past. The objectives of this study were to clarify the absorption, translocation and metabolic fate of metamitron in C. album.

RESULTS: Root absorption and foliar absorption experiments showed minor differences in absorption, translocation and metabolism of metamitron between the susceptible and resistant C. album populations. A rapid metabolism in the C. album populations was observed when metamitron was absorbed by the roots. The primary products of metamitron metabolism were identified as deamino‐metamitron and metamitron‐N‐glucoside. PABA, known to inhibit the deamination of metribuzin, did not alter the metabolism of metamitron, and nor did the cytochrome P450 inhibitor PBO. However, inhibition of metamitron metabolism in the presence of the cytochrome P450 inhibitor ABT was demonstrated.

CONCLUSION: Metamitron metabolism in C. album may act as a basic tolerance mechanism, which can be important in circumstances favouring this degradation pathway. Copyright © 2011 Society of Chemical Industry
Site factors and management influence short‐term host resistance to spruce budworm, Choristoneura fumiferana (Clem.), in a species‐specific manner
Authors: Fuentealba Alvaro , Bauce Éric
Published: July 2011

BACKGROUND: This study examined the interactions between thinning and soil drainage classes on the resistance of balsam fir, Abies balsamea (L.) Mill, white spruce, Picea glauca (Moench) Voss, and black spruce, P. mariana (Mill.) BSP, to spruce budworm, Choristoneura fumiferana (Clem.), defoliation 1 year after treatment. To estimate host tree resistance, foliage production and larval foliage consumption were determined to generate an index of resistance quantifying the amount of residual foliage available for photosynthesis after insect defoliation.

RESULTS: Significant interactions on tree resistance and foliage chemistry were detected between thinning and soil drainage in balsam fir. Drainage class affected spruce budworm performance, foliar chemistry and balsam fir resistance to spruce budworm, whereas no effect was found in white spruce. Thinning had a significant effect on the foliar chemistry of balsam fir and white spruce, but no effect on black spruce.

CONCLUSION: Thinning reduced balsam fir resistance to spruce budworm defoliation. This response is due to increased defoliation linked to reduction in concentrations of certain monoterpenes, and a decrease in foliage production, except on hydric drainage, demonstrating the importance of drainage class to tree resistance. The results suggest that the use of Bacillus thuringiensis might be required when conducting stand thinning during spruce budworm outbreaks. Copyright © 2011 Society of Chemical Industry
Ar ion bombardment modification of Pd–Au/MWCNTs catalyst surfaces studied by electron spectroscopy
Authors: Lesiak B. , Stobinski L. , Kövér L. , Tóth J. , Kurzydłowski K. J.
Published: July 2011

The Pd–Au multiwall carbon nanotubes (MWCNTs) supported catalyst prepared by polyol method was found to be catalytically active material in direct formic acid fuel cell electrooxidation reaction and during cyclic voltammetry (CV) measurements. The surface of the catalyst after calcination and reduction treatments was investigated previously. The effect of Ar ion bombardment modification on the calcinated catalyst was studied by electron spectroscopy. The chemical and structural changes were deduced from the X‐ray photoelectron spectroscopy (XPS) and X‐ray excited Auger electron spectroscopy (XAES) spectra. The XPS quantitative and qualitative analysis of different chemical forms of atoms indicated that the sputtering causes an increase of Pd surface content, accompanied by decreasing content of N, O, C sp2, and Au (due to preferential sputtering of Au) and significant increase of C sp3 amount. A decrease was also observed in the surface content of (i) carboxyl groups, (ii) water, and (iii) Pd oxide (mainly less stable PdO2). Analysis of XPS inelastic background shape by QUASES indicates that Pd crystallites phase is covered by PdOx + Camorphous overlayer of decreasing thickness after sputtering. Namely, thickness of PdOx overlayer decreased from 8.2 to 3.5 nm and the thickness of amorphous carbon overlayer located on the top increased from 2.3 to 3.5 nm. Significant increase of C sp3 content results from carbon nanotube (CNT) π bonds damaging, whereas decrease of PdO2 content from lower stability of PdO2. Larger thickness of Camorphous overlayer, in contrary to PdOx, may result from higher preferential sputtering of oxygen than carbon atoms and cracking of the MWCNTs structure by Ar+ ions.
C60‐doping of nanostructured Bi–Sb–Te thermoelectrics
Authors: Popov Mikhail , Buga Sergei , Vysikaylo Philipp , Stepanov Petr , Skok Vasilii , Medvedev Viacheslav , Tatyanin Evgeny , Denisov Viktor , Kirichenko Alexei , Aksenenkov Viktor , Blank Vladimir
Published: July 2011

New bulk nanocomposite thermoelectric materials composed from nanocrystallites of Bi–Sb–Te alloys covered by C60 molecules have been synthesized and studied. The fullerene molecules provide thermal phonons blocking and particular charge transfer in the nanocomposite. The molecules act as electron traps, and thus decrease the density of free electrons in n‐type semiconductor and generate holes in p‐type materials. The capture of electrons is not accompanied by shifts of the Raman bands in C60 spectra. The density of free charge carriers and their Hall mobility change nonmonotonically with the increase of fullerene content in Bi–Sb–Te–C60 nanocomposites. The maximum value of thermoelectric figure of merit ZT = 1.15 was obtained in p‐type nanocomposite that is 30% higher than in the undoped starting material. The observed phenomenon provides new ways for transport properties optimization of thermoelectric materials and thermoelectric devices efficiency increase.
Slow de‐trapping of minority holes in n‐type 4H‐SiC epilayers
Authors: Klein P. B. , Shrivastava A. , Sudarshan T. S.
Published: July 2011

The carrier lifetime in epilayers of n‐type 4H‐SiC with low concentrations of the Z1/2 lifetime killer has been investigated over a wide range of temperature under low injection conditions. It was found that in addition to the primary initial decay dominated by surface recombination (SR), as determined by previous work, in some samples a slow decay component is observed, exhibiting a thermally activated recombination rate. Such a slow tail on the carrier decay can be of concern in high voltage switching devices. The slow decay was well accounted for by the thermal emission of minority carriers trapped on a defect. The resulting analysis has determined that the responsible trap is located ≈Ev + (0.37–0.58) eV with relatively small capture cross‐sections for both electrons and holes: σp ≈ (0.5–12) × 10−17 cm2; σn < (0.3–8) × 10−18 cm2. Comparing these characteristics with reports in the literature for as‐grown materials, the most likely candidates for the responsible defects are the D‐ and/or i‐centers, which have similar ionization energies and capture cross‐sections.
Growth and characterization of nitride‐based distributed Bragg reflectors
Authors: Kruse Carsten , Dartsch Heiko , Aschenbrenner Timo , Figge Stephan , Hommel Detlef
Published: July 2011

We report on a systematic study concerning the realization of nitride‐based distributed Bragg reflectors (DBRs) for opto‐electronic applications in the near‐UV to visible spectral range. Different material combinations are used in order to find an optimized trade‐off concerning peak reflectivity, stop band width, and strain state of the Bragg mirrors. For the high refractive index material GaN is used in all cases, while for the low index material a layer of either AlGaN or AlInN, respectively, or a AlN/(In)GaN short‐period superlattice (SL) is employed. The best peak reflectivity of 97% at a wavelength of 495 nm is achieved for a lattice matched Bragg reflector based on the GaN/AlInN material combination.

magnified image

Transmission electron microscopy image of a 30‐fold distributed Bragg reflector consisting of AlInN (dark) and GaN (bright) layers.
Investigations into the Antiadhesive Activity of Herbal Extracts Against Campylobacter jejuni
Authors: Bensch K. , Tiralongo J. , Schmidt K. , Matthias A. , Bone K. M. , Lehmann R. , Tiralongo E.
Published: July 2011

Campylobacter jejuni is one of the most common bacterial causes of diarrhoea in the industrialized world, being associated with the occurrence of Guillain‐Barré Syndrome, and inducing diseases partially through intestinal adherence. With increasing reports of C. jejuni drug resistance against standard antibiotics, investigations into antiadhesive agents for the prevention of bacterial infection are highly significant. Given the consumer‐driven development towards holistic and integrative healthcare, research into additional anti‐Campylobacter effects of herbal medicines that are already used for their beneficial effects on bowel and digestive functions is important.

Twenty‐one herbal extracts were screened for antiadhesive activity against C. jejuni using modifications of previously published antiadhesion assays. Antiadhesion effects with IC50 values <3 mg/mL were obtained for seven ethanol plant extracts, with Zingiber officinale (ginger), Capsicum annum (cayenne) and Glycyrrhiza glabra (licorice) displaying the highest antiadhesion activity against C. jejuni (IC50: <0.1 mg/mL, 0.29 mg/mL and 0.65 mg/mL, respectively). Differences in antiadhesion activity were found for two different Echinacea species, with E. purpurea displaying significantly higher and dose dependent antiadhesion activity than E. angustifolia. No significant antiadhesion activity (IC50 values >35 mg/mL) was found for Agrimonia eupatoria (agrimony), Andrographis paniculata (andrographis), Matricaria recutita (chamomile), Foeniculum vulgare (fennel), Filipendula ulmaria (meadowsweet) and Artemisia absinthium (wormwood) extracts.

This study provides evidence for additional beneficial effects of marketed herbal medicines in gastrointestinal disorders. Copyright © 2011 John Wiley & Sons, Ltd.
Preventive Action of Panax ginseng Roots in Hypercortisolism‐induced Impairment of Hippocampal Neurons in Male C57BL/6N Mice
Authors: Wang Zhongli , Dai Jianguo , Chen Lin , Huang Yufang , Zhao Yunan
Published: July 2011

An increasing number of people suffering from hypercortisolism are at risk of developing hippocampus impairment and mental disorders. The aim of this study was to investigate whether the water extract of Panax ginseng roots (GWE) could prevent hypercortisolism‐induced adverse consequences. Hypercortisolism was experimentally induced by repeated corticosterone injection in male mice. Treatment with corticosterone alone resulted in a significant decrease in hippocampus neurofilament light chain (NF‐L) protein expression and induced depression‐like behavior. Serum corticosterone was significantly increased in the corticosterone‐treated mice. Treatment with GWE (800 and 400 mg/kg) during corticosterone treatment reduced or partially antagonized the effects induced by corticosterone toward the normal values of the controls; however, it failed to normalize increased corticosterone levels in corticosterone‐treated mice. Overall, ginseng conclusively exhibited a protective action against hypercortisolism‐induced impairment of hippocampal neurons. Copyright © 2011 John Wiley & Sons, Ltd.
The Protective Effect and Action Mechanism of Vaccinium myrtillus L. on Gastric Ulcer in Mice
Authors: Ogawa Kenjirou , Oyagi Atsushi , Tanaka Junji , Kobayashi Saori , Hara Hideaki
Published: July 2011

Vaccinium myrtillus L. anthocyanoside (VMA) is used as a folk medicine to treat diseases related to gastric ulcers in northern Europe. However, the effects of VMA and its detailed mechanism on gastric ulcer have not been investigated sufficiently. Therefore, the aim of the present study was to investigate the protective effects of VMA on gastric mucosal damage in a murine gastric ulcer model. First the effects of VMA on ethanol‐induced gastric ulcers in mice were investigated. Then, the levels of lipid peroxide in murine stomach homogenates were measured to investigate the antioxidative effects of VMA. In addition, the free radical scavenging activity of VMA and its main anthocyanidins were evaluated by electron spin resonance measurement. Oral administration of VMA (10, 30 and 100 mg/kg) significantly protected gastric mucosa against HCl/ethanol‐induced gastric ulcers. Furthermore, VMA inhibited lipid peroxide levels in a concentration‐dependent manner and showed high scavenging activity against the superoxide anion radical (·O2‐) and the hydroxyl radical (·OH). Anthocyanidins also showed scavenging activity against the ·O2‐, while only delphinidin showed high scavenging activity against the ·OH. These findings indicate that the protective effects of VMA on HCl/ethanol‐induced gastric mucosal injury may be partially due to the antiperoxidative effects of anthocyanidins. Copyright © 2011 John Wiley & Sons, Ltd.