bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast detection of hydrogen sulfide using a biodegradable colorimetric indicator system
Authors: Kato Edison T , Yoshida Cristiana MP , Reis Arlete B , Melo Itamar S , Franco Telma T
Published: May 2011

A fast, colorimetric indicator system was developed by combining chitosan as a three‐dimensional biopolymer matrix and ferrous sulfate (FeSO4) as a colorimetric indicator of hydrogen sulfide (H2S) gas. Chitosan filmogenic suspensions (3.0% w/w) were obtained and FeSO4 was incorporated at 2.0 wt%. The colour parameters were measured using a colorimeter, after subjecting the system to various H2S exposure times. The novelty of this work is the biodegradability, a test performed in soil, which showed a weight loss of about 67% after 60 days, and the fast device formation indicating the presence of H2S gas. The chitosanFeSO4 system detected the presence of H2S in concentrations equal to or greater than 100 ppm within 30 s of exposure and produced a visual black colour as a response to the presence of H2S. Copyright © 2011 Society of Chemical Industry
Star poly(2‐ethyl‐2‐oxazoline)s—synthesis and thermosensitivity
Authors: Kowalczuk Agnieszka , Kronek Juraj , Bosowska Kornelia , Trzebicka Barbara , Dworak Andrzej
Published: May 2011

A series of star‐shaped poly(2‐ethyl‐2‐oxazoline)s was prepared by cationic polymerization. The polymerization was initiated by dipentaerythrityl hexakis(4‐nitrobenzene sulfonate) and a tosylated hyperbranched polymer of glycidol. The polymerization proceeded in a controlled manner. The star structure of the products was determined by nuclear magnetic resonance. The molar mass distributions that were measured by gel permeation chromatography with multiangle laser light scattering were narrow, and the experimental values of the molar masses were close to those predicted. The very compact structure of the polymers obtained (compared with the linear counterparts) confirmed the star formation. The star poly(2‐ethyl‐2‐oxazoline)s show a phase transition temperature in the range 62–75 °C. Comparison of this phase transition temperature with that of the linear poly(2‐ethyl‐2‐oxazoline)s with the same molar masses indicates the influence of molar mass and topological structure of the macromolecule on temperature behavior. The prepared copolymers are spherical, which might be useful for the controlled transport and release of active compounds. Copyright © 2011 Society of Chemical Industry
Die Entdeckung verlorener Kunst. Kunstgeschichtliche Forschung mit Synchrotronstrahlung
Authors: Appel Karen , Alfeld Matthias , Dik Joris
Published: May 2011

Kunstwerke wurden oft von den Künstlern übermalt und gingen so der Kunstgeschichte verloren. Eine neue Methode der Röntgenfluoreszenzanalyse mit Synchrotronlicht ermöglicht die Rekonstruktion solcher übermalter Bilder. Durch eine Kombination der beim Durchleuchten erhaltenen Elementverteilungsbilder mit Informationen über die chemische Bindung der Elemente können die Bilder sogar koloriert werden. Diese Methode eignet sich auch zur Echtheitsprüfung. Mit ihr lassen sich zudem abgeschabte Schriften wieder sichtbar machen.
Naturkonstanten als solide Basis. Neudefinition der Einheit Kelvin
Authors: Fischer Joachim , Fellmuth Bernd , Gaiser Christof , Zandt Thorsten
Published: May 2011

Die Entwicklung der sogenannten Primärthermometer macht erhebliche Fortschritte. Mit ihnen wird die Boltzmann‐Konstante in wenigen Jahren so exakt bestimmbar sein, dass die einmalige Festlegung ihres Zahlenwertes eine Neudefinition des Kelvins ermöglicht. Damit wird eine Naturkonstante anstelle einer Maßverkörperung zum Maßstab. Die wesentlichen Konsequenzen sind langfristiger Natur, denn das Maßsystem für die Temperatur wäre dann zeitlich unbegrenzt stabil. Dieses Ziel lohnt die weltweite Anstrengung.
Verschränkte Photonen auf Eis gelegt
Authors: Tittel Wolfgang , Sohler Wolfgang
Published: May 2011

Quantennetzwerke und lange quantenoptische Übertragungsstrecken benötigen Quantenrepeater, deren wesentliche Komponenten Quantenspeicher sind. Sie erlauben, verschränkte Photonen (genauer: deren Quantenzustände) für eine gewisse Zeit zu speichern und kontrolliert wieder auszulesen. Die Kombination eines mit Thulium dotierten optischen Wellenleiters in Lithiumniobat als Speichermedium mit einem kürzlich entwickelten Quantenspeicherprotokoll und einer neuen, schmalbandigen Photonenpaarquelle hat es uns erstmalig ermöglicht, Quantenzustände reversibel von verschränkten Photonen auf einen Kristall zu übertragen. Ähnliche Ergebnisse, aber mit einem anderen Speichermedium, berichtete zeitgleich ein Forscherteam der Universität Genf.
Platzende Ballons – Retardierung in der Mechanik
Authors: Vollmer Michael , Möllmann Klaus‐Peter
Published: May 2011

Die endliche Ausbreitungsgeschwindigkeit einer Störung führt zu einer verzögerten Wirkung. Dieses Phänomen nennt man in der Physik Retardierung. Am häufigsten werden retardierte elektromagnetische Felder oder Potentiale in der Elektrodynamik behandelt. Auch in der Mechanik sind solche Verzögerungseffekte bei der Schallausbreitung in Luft oder Gasen ohne weiteres wahrnehmbar, beispielsweise beim Echo. Deutlich schwieriger beobachtbar sind sie in der Mechanik nichtgasförmiger Materialien. Hochgeschwindigkeitskameras zeigen dieses Phänomen auf beeindruckende Weise.
Keine lange Leitung
Authors: Rolfs Claus
Published: May 2011

Eine schnelle Reaktion ist im Tierreich wichtig, sie kann über Leben und Tod entscheiden. Auch Pflanzen reagieren mitunter auf die Umwelt, nur meist erheblich langsamer als Tiere oder der Mensch. Physikalische Abschätzungen geben Auskunft über die Zeitskalen.
Gele mit Mundgefühl
Authors: Vilgis Thomas
Published: May 2011

Warum sind Puddings so beliebt? Abgesehen von zahlreichen Geschmacksrichtungen bestimmt auch das Mundgefühl und damit die Essphysik die Liebe zu gelierten Produkten, deren Festigkeit und Schmelz gezielt gesteuert werden kann. Auch die Küche profitiert davon: Mit den Geliermitteln Agar‐Agar und Gelatine lassen sich interpenetrierende Netzwerke zu kulinarischen Köstlichkeiten heben.
“Clickable” polymers via a combination of RAFT polymerization and isocyanate chemistry
Authors: Moraes John , Maschmeyer Thomas , Perrier Sébastien
Published: May 2011

We describe a facile, one‐pot, two‐step polymerization towards synthesizing block co‐polymers bearing reactive isocyanate functional groups. Reversible addition fragmentation chain transfer (RAFT) polymerization is used to mediate the co‐polymerization of isocyanate‐bearing monomers dimethyl meta‐isopropenyl benzyl isocyanate (TMI) and 2‐isocyanatoethyl methacrylate (ICEMA) with styrene and methyl methacrylate (MMA), respectively. ICEMA was incorporated into the polymer at a faster rate than TMI and its unhindered isocyanate group was found to be more reactive than the hindered isocyanate group of TMI. Both the TMI/styrene and the MMA/ICEMA systems maintain the reactivity of the isocyanate functionality, which was exploited by attaching representative hydroxyl‐bearing small and large molecules as well as solid substrates to the block co‐polymers. Thus, we demonstrate the versatility of the block co‐polymer system as a basis for forming branched polymers or as grafts for a solid substrate. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Polyamide 6‐polycaprolactone multiblock copolymers: Synthesis, characterization, and degradation
Authors: Cakir Seda , Kierkels René , Koning Cor
Published: May 2011

This work describes the synthesis and characterization of polyamide 6 (PA 6)‐polycaprolactone (PCL) multiblock copolymers. Low molar mass, fully amine end‐capped PA 6 was prepared by the addition of a diamine monomer during ε‐caprolactam polymerization. A low molar mass PCL was selected to be incorporated as the biodegradable block and was fully end‐capped with toluene 2,4‐diisocyanate. End group analysis and molecular weight characterizations were performed for both end‐functionalized polymers by SEC, NMR and titration analysis. Incorporation of PCL into PA 6 was mainly achieved by solution mixing of the two end‐functional blocks and, was continued after the removal of the solvent with solid state polymerization (SSP) by gradual heating until about 40 °C below the melting temperature of the PA 6. Molecular weights started to grow immediately during solution mixing and only increased marginally during the SSP treatment. FTIR and SEC studies confirmed the reaction between the two components. DSC data, in combination with the enhanced molar mass during solution mixing pointed to a blocky microstructure, for which distinct melting and crystallization temperatures were observed for the PCL and the PA 6 blocks. Hydrolytic and enzymatic degradation studies were performed at 25 °C where the degree of degradation was followed by weight loss analysis, SEM and SEC. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and characterization of pH‐sensitive and thermosensitive double hydrophilic graft copolymers
Authors: Tu You‐Liang , Wang Cheng‐Chien , Chen Chuh‐Yung
Published: May 2011

A series of poly(N‐isopropylacrylamide)‐co‐poly(Nε‐benzyloxycarbonyl‐L‐lysine) graft copolymers (PNIPAm‐co‐PZLLys) with different side chains (degree of polymerization, DP = 5∼40) and unit ratios (from 30 to 70 mol %) were prepared via free radical polymerization, followed by cleaving benzyloxycarbonyl groups (Z groups) to obtain the double hydrophilic graft copolymer, poly(N‐isopropylacrylamide)‐co‐poly(L‐lysine) (PNIPAm‐co‐PLLys). The pH‐ and temperature‐response properties of the graft copolymers in aqueous solution were studied. The experimental results indicate L15‐N30 and L15N‐70, that is, the PNIPAm‐co‐PLLys having the poly(L‐lysine) of DP = 15 as side chains as well as 30 and 70 mol %, respectively, of PNIPAm as backbone, have coil‐to‐helix transitions from pH 6 to pH 12 at room temperature and form uniform nanoscale micelle‐like dispersions in aqueous solution at pH 12. The graft copolymers also could form uniform and nanoscale micelle‐like structures at 50 °C in pH 6 buffer solution due to slightly polymer aggregation. With temperature and pH increased, both the deprotonated PLLys side chains and PNIPAm backbone become hydrophobic, leading to polymer precipitation. These results illustrate that a double tunable hydrophilic graft copolymer had been successfully synthesized via a simple radical polymerization, and could form micelles without serious polymer aggregation at a lower pH and a higher temperature. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Efficient carbonyl hydrosilylation reaction: Toward EVA copolymer crosslinking
Authors: Bonnet Julien , Bounor‐Legaré Veronique , Boisson Fernande , Mélis Flavien , Cassagnau Philippe
Published: May 2011

In this article, the hydrosilylation reaction of carbonyl groups of acetate derivatives and SiH groups of hydride‐terminated polydimethylsiloxane at high temperature (100–130 °C) are described. Triruthenium dodecacarbonyl, Ru3(CO)12, was used as effective catalyst for hydrosilylation reaction. The hydrosilylation reactions with octyl acetate and 4‐heptyl acetate were investigated by multinuclear NMR spectroscopy (1H, 13C, and 29Si). This work provides evidence of the addition reaction of SiH groups onto carbonyl groups. The influence of the nature of the acetate structure on the reaction kinetics was shown and the slight contribution of side reactions at high temperature highlighted. Hydrosilylation reaction was extent to the crosslinking of ethylene‐vinyl acetate (EVA) copolymer in the same range of temperature. The formation of EVA chemical network was demonstrated by HR‐MAS NMR spectroscopy and by measuring the gel fraction of EVA chains in hot toluene. From Flory theory, the crosslinking density of elastic strand was calculated to be 80 mol m−3 in agreement with the measurements from swelling ratio (VA/SiH molar ratio: 11.8). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Poly(arylene ether)s with pendant diphenyl phosphoryl groups: Synthesis, characterization, and thermal properties
Authors: Tienda Kevin , Yu Zhenning , Constandinidis Fadwa , Fortney Andria , Feld William A. , Fossum Eric
Published: May 2011

A series of poly(arylene ether)s, (PAEs), carrying a pendant diphenyl phosphoryl group were prepared via the nucleophilic aromatic substitution (NAS) reactions of 3,5‐difluorotriphenylphosphine oxide, 6. The difluoro monomer 6 was synthesized via two‐step reaction sequence and subsequently characterized by 1H, 13C, 19F, and 31P NMR spectroscopy, GC/MS, and elemental analysis. The reactivity of the electrophilic sites in 6, activated by only a diphenylphosphoryl group located in the meta‐position, in 6 was probed via NMR spectroscopy and model reactions and was determined to be sufficient to undergo typical NAS reactions. High molecular weight, amorphous, organic soluble poly(arylene ether)s, bearing a pendant diphenylphosphoryl group, were prepared via the reaction of 6 with a variety of bis‐phenols under typical NAS conditions. The poly(arylene ether)s were characterized for structure via the use of 1H, 13C, and 31P NMR spectroscopy while their thermal properties were evaluated using DSC and TGA analysis. The glass transition temperatures (Tg) of the synthesized PAEs ranged from 143 to 175 °C, while their 5% weight loss temperatures ranged from 467 to 510 °C under nitrogen and from 470 to 526 °C in air. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Structure and mechanical properties controlling of elastomer modified polypropylene by compounded β/α nucleating agents
Authors: Li Xiaoxi , Wu Haiyan , Dai Jian , Huang Ting , Wang Yong
Published: May 2011

Previous work showed that there was a synergistic effect of nucleating agent (NA) and elastomer in improving the fracture resistance of isotactic polypropylene (PP), relating to the formation of large amounts of β‐PP (β‐NA nucleated system) or the decrease of the spherulites diameters of α‐PP (α‐NA nucleated system). To find the direct relation between the synergistic efficiency of NA/elastomer and the microstructures of the materials, in this work, the ethylene‐propylene‐diene terpolymer (EPDM) modified PP blends with compounded NAs (β/α) were adopted and the changes of the microstructure and mechanical properties were investigated comparatively. The results showed that, with the adjustment of the mass fraction of compounded NAs, the microstructures of PP matrix including supermolecular structure and the relative fraction of β‐PP (Kβ) change accordingly. Specifically, the Kβ of β‐PP was successfully adjusted in the wide range of 0–78.9%. Consequently, the stiffness and the fracture resistance of the PP/EPDM blends were easily controlled in different degrees. It is believed that this work could provide a guide map for the design and preparation of certain polymer blends satisfying certain requirement. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Effect of molecular shape of diisocyanate units on the microscopic/macroscopic phase separation structure of polyurethanes
Authors: Park Kiho , Lim Wan Hee , Ko Eun‐A , Lee Han Sup
Published: May 2011

Three diisocyanate units having different linearity and planarity on the basis of the arrangement of constituent aromatic rings are used to synthesize three polyurethanes (PUs) and the effects of the molecular structure of the diisocyanate units on phase separated morphologies of PUs have been studied. The linear and planar diisocyanate unit allows good packing of the hard segments in the hard domain by extensive intersegmental hydrogen bonding, and it forms a well ordered, long hard domain. However, the nonlinear and noncoplanar diisocyanate unit shows a lesser degree of hydrogen bonding in the short hard domain. Strong preferential orientation of the rigid/long hard domains inside a macroscopic grain boundary has been observed with the polarizing optical microscope especially for the PU based on the rigid diisocyanate. It was concluded that the molecular structure of the diisocyanate unit in PU plays an important role in determining the interchain interaction, the detailed phase‐separated domain structure, and local domain orientation in each grain boundary. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Fear of movement in cancer survivors: validation of the Modified Tampa Scale of Kinesiophobia—Fatigue
Authors: Velthuis Miranda J. , Van den Bussche Eva , May Anne M. , Gijsen Brigitte C. M. , Nijs Sara , Vlaeyen Johan W. S.
Published: May 2011

Objective: To date, there is no validated questionnaire to assess fear of movement in cancer survivors. We aim to validate the Modified Tampa Scale of Kinesiophobia‐Fatigue (TSK‐F) in Dutch cancer survivors participating in a rehabilitation programme. We first select the optimal model for cancer survivors. Subsequently, stability, internal consistency, and construct validity of the optimal model is tested.

Methods: A sample of 658 cancer survivors participating in a rehabilitation programme was included. Out of nine models derived in chronic pain and chronic fatigue patients, the optimal model of the TSK‐F was selected in a calibration sample (n1 = 329) using confirmatory factor analysis. Stability of the derived optimal model was confirmed in a validation sample (n2 = 329). Internal consistency and construct validity were assessed in the full sample.

Results: The 11‐item two‐factor model of the TSK‐F was the best‐fitting model for cancer survivors and it seemed to be invariant for sex and cancer diagnosis. Internal consistency of the model was acceptable (Cronbach's alpha between 0.62 and 0.74). Construct validity was illustrated by significant associations between TSK‐F total and TSK‐F somatic focus with perceived global health status (EORTC‐QOL‐C30) and fatigue (FACT‐F) (p<0.001).

Conclusions: The adjusted 11‐item TSK‐F consisting of two subscales ‘somatic focus’ and ‘activity avoidance’ seems to be a robust and valid tool in measuring fear of movement in cancer survivors with an acceptable internal consistency. Further psychometric testing of the TSK‐F in cancer survivors is recommended. In the future, TSK‐F scores may be used to customise rehabilitation programmes in cancer survivors.Copyright © 2011 John Wiley & Sons, Ltd.
Clinical validation of the EORTC QLQ‐OG25 questionnaire for the evaluation of health‐related quality of life in Mexican patients with esophagogastric cancers
Authors: Oñate‐Ocaña Luis F. , Velázquez‐Monroy Natalia , Vázquez Luis , Espinosa‐Mireles‐de‐Villafranca Pablo , Núñez‐Rosas Elvia , Ovando‐Lezama Maira , Vilar‐Compte Diana , García‐Hubard Gabriela , Carrillo José F. , Blazeby Jane M. , Aiello‐Crocifoglio Vincenzo
Published: May 2011

Background: Quality of life questionnaires (QLQ) QLQ‐STO22 and QLQ‐OES18 are currently available to measure Health‐related quality of life (HRQL) in patients with Esophageal (EC) or Gastric cancer (GC). The QLQ‐OG25 integrates questions from both questionnaires to be useful for EC, Esophagogastric junction carcinoma (EGJC), and GC. Our aim was to validate the Mexican‐Spanish version.

Patients and Methods: The translation procedure followed European Organization for Research and Treatment of Cancer (EORTC) guidelines. QLQ‐C30 and QLQ‐OG25 instruments were completed by patients with EC, EGJC, and GC. Patients were divided into three groups: (1) palliative treatment; (2) treatment with curative intent, and (3) survivors. Reliability and validity tests were performed.

Results: One‐hundred sixty‐three patients were included: 62 women and 101 men (mean age, 54.9 years; range, 22–82 years). Sixty‐nine, seventy‐three, and twenty‐one patients were allocated into groups 1, 2, and 3, respectively. Questionnaire compliance rates were high and were well accepted. Group 3 patients reported better functional HRQL scores and lower symptom scores than patients in groups 2 and 1. Scales in the QLQ‐C30 and QLQ‐OG25 distinguished among other clinically distinct groups of patients. Cronbach's α coefficients of all multi‐item scales of the QLQ‐OG25 instrument were >0.7 (range, 0.7–0.83). Multitrait scaling analysis demonstrated good convergent and discriminant validity, even adjusting by location. Test–retest scores were consistent.

Conclusion: The Mexican‐Spanish version of the EORTC QLQ‐OG25 questionnaire is reliable and valid for HRQL measurement in patients with esophagogastric cancer and can be used in clinical trials in the Mexican community. Copyright © 2011 John Wiley & Sons, Ltd.
Cardiopulmonary function and oxygen delivery during total liquid ventilation
Authors: Tsagogiorgas Charalambos , Alb Markus , Herrmann Peter , Quintel Michael , Meinhardt Juergen P.
Published: May 2011

Introduction

Total liquid ventilation (TLV) with perfluorocarbons has shown to improve cardiopulmonary function in the injured and immature lung; however there remains controversy over the normal lung. Hemodynamic effects of TLV in the normal lung currently remain undetermined. This study compared changes in cardiopulmonary and circulatory function caused by either liquid or gas tidal volume ventilation.

Methods

In a prospective, controlled study, 12 non‐injured anesthetized, adult New Zealand rabbits were primarily conventionally gas‐ventilated (CGV). After instrumentation for continuous recording of arterial (AP), central venous (CVP), left artrial (LAP), pulmonary arterial pressures (PAP), and cardiac output (CO) animals were randomized into (1) CGV group and (2) TLV group. In the TLV group partial liquid ventilation was initiated with instillation of perfluoroctylbromide (12 ml/kg). After 15 min, TLV was established for 3 hr applying a volume‐controlled, pressure‐limited, time‐cycled ventilation mode using a double‐piston configured TLV. Controls (CGV) remained gas‐ventilated throughout the experiment.

Results

During TLV, heart rate, CO, PAP, MAP, CVP, and LAP as well as derived hemodynamic variables, arterial and mixed venous blood gases, oxygen delivery, PVR, and SVR did not differ significantly compared to CGV.

Conclusions

Liquid tidal volumes suitable for long‐term TLV in non‐injured rabbits do not significantly impair CO, blood pressure, and oxygen dynamics when compared to CGV. Pediatr. Pulmonol. 2011; 46:964–975. © 2011 Wiley‐Liss, Inc.
Specificity of HCPTP variants toward EphA2 tyrosines by quantitative selected reaction monitoring
Authors: Balasubramaniam Deepa , Paul Lake N. , Homan Kristoff T. , Hall Mark C. , Stauffacher Cynthia V.
Published: May 2011

EphA2 receptor tyrosine kinase and the human cytoplasmic protein tyrosine phosphatase (HCPTP) are overexpressed in a number of epithelial cancers. Overexpressed EphA2 in these cancers shows a significant decrease in phosphotyrosine content which results in suppression of receptor signaling and endocytosis and an increase in metastatic potential. The decreased phosphotyrosine content of EphA2 has been associated with decreased contact with its ligand, ephrin A1 and dephosphorylation by HCPTP. Potential specificity of the two HCPTP variants for tyrosines on EphA2 has not been investigated. We have used a mass spectrometry assay to measure relative rates of dephosphorylation for the two HCPTP variants at phosphotyrosine sites associated with control of the EphA2 kinase activity or interaction with downstream targets. Our results suggest that although both variants dephosphorylate the EphA2 receptor, the rate and specificity of dephosphorylation for specific tyrosines are different for HCPTP‐A and HCPTP‐B. The SAM domain tyrosine Y960 which has been implicated in downstream PI3K signaling is dephosphorylated exclusively by HCPTP‐B. The activation loop tyrosine (Y772) which directly controls kinase activity is dephosphorylated about six times faster by HCPTP‐A. In contrast, the juxtamembrane tyrosines (Y575, Y588 and Y594) which are implicated in both control of kinase activity and downstream signaling are dephosphorylated by both variants with similar rates. This difference in preference for dephosphorylation sites on EphA2 not only illuminates the different roles of the two variants of the phosphatase in EphA2 signaling, but also explains why both HCPTP variants are highly conserved in most mammals.
X‐ray structural studies of quinone reductase 2 nanomolar range inhibitors
Authors: Pegan Scott D. , Sturdy Megan , Ferry Gilles , Delagrange Philippe , Boutin Jean A. , Mesecar Andrew D.
Published: May 2011

Quinone reductase 2 (QR2) is one of two members comprising the mammalian quinone reductase family of enzymes responsible for performing FAD mediated reductions of quinone substrates. In contrast to quinone reductase 1 (QR1) which uses NAD(P)H as its co‐substrate, QR2 utilizes a rare group of hydride donors, N‐methyl or N‐ribosyl nicotinamide. Several studies have linked QR2 to the generation of quinone free radicals, several neuronal degenerative diseases, and cancer. QR2 has been also identified as the third melatonin receptor (MT3) through in cellulo and in vitro inhibition of QR2 by traditional MT3 ligands, and through recent X‐ray structures of human QR2 (hQR2) in complex with melatonin and 2‐iodomelatonin. Several MT3 specific ligands have been developed that exhibit both potent in cellulo inhibition of hQR2 nanomolar, affinity for MT3. The potency of these ligands suggest their use as molecular probes for hQR2. However, no definitive correlation between traditionally obtained MT3 ligand affinity and hQR2 inhibition exists limiting our understanding of how these ligands are accommodated in the hQR2 active site. To obtain a clearer relationship between the structures of developed MT3 ligands and their inhibitory properties, in cellulo and in vitro IC50 values were determined for a representative set of MT3 ligands (MCA‐NAT, 2‐I‐MCANAT, prazosin, S26695, S32797, and S29434). Furthermore, X‐ray structures for each of these ligands in complex with hQR2 were determined allowing for a structural evaluation of the binding modes of these ligands in relation to the potency of MT3 ligands.
Dynamical cosmological term in modified gravity
Authors: Solà J.
Published: May 2011

The experimental evidence that the equation of state (EoS) of the dark energy (DE) could be evolving with time, suggests that the Λ‐term in the gravity action should rather be an effective quantity Λeff(t) involving new dynamical terms X(t). Remarkably, a class of these ΛXCDM models could be the clue for solving the old cosmological constant problem, including the cosmic coincidence problem. We propose a permanent (i.e. not just a late‐time) modification of gravity which is able to account for these problems, and without affecting the standard cosmological evolution of the universe.
Inhibition of Stat3 activation by sanguinarine suppresses prostate cancer cell growth and invasion
Authors: Sun Meng , Liu Chengfei , Nadiminty Nagalakshmi , Lou Wei , Zhu Yezi , Yang Joy , Evans Christopher P. , Zhou Qinghua , Gao Allen C.
Published: May 2011

BACKGROUND

Signal transducer and activator of transcription 3 (Stat3) is an oncogenic transcriptional factor that plays a critical role in carcinogenesis and cancer progression and is a potential therapeutic target. Sanguinarine, a benzophenanthridine alkaloid derived primarily from the bloodroot plant, was identified previously as a novel inhibitor of survivin that selectively kills prostate cancer cells over “normal” prostate epithelial cells.

METHODS

DU145, C4‐2B, and LNCaP cells were treated with sanguinarine. The phosphorylation status of Stat3 and related proteins were measured with Western blots. Activation of transcription by Stat3 was measured with luciferase reporter assay. The effect of sanguinarine on anchorage‐independent growth was examined with soft agar assay, and on cell migration and invasion of DU145 cells were measured with scratch assay and invasion assay, respectively.

RESULTS

In this study, we identified sanguinarine as a potent inhibitor of Stat3 activation which was able to suppress prostate cancer growth, migration, and invasion. Sanguinarine inhibits constitutive as well as IL6‐induced phosphorylation of Stat3 at both Tyr705 and Ser727 in prostate cancer cells. The inhibition of Stat3 phosphorylation by sanguinarine correlates with reduction of Janus‐activated Kinase 2 (Jak2) and Src phosphorylation. Sanguinarine downregulates the expression of Stat3‐mediated genes such as c‐myc and survivin and inhibits the Stat3 responsive element luciferase reporter activity. Sanguinarine inhibits the anchorage‐independent growth of DU145 and LN‐S17 cells expressing constitutively activated Stat3. Migration and invasion abilities of DU145 cells were also inhibited by sanguinarine in a manner similar to the dominant negative form of Stat3.

CONCLUSIONS

These data demonstrate that sanguinarine is a potent Stat3 inhibitor and it could be developed as a therapeutic agent for prostate cancer with constitutive activation of Stat3. Prostate 72:82–89, 2012. © 2011 Wiley Periodicals, Inc.
HDAC inhibitor MS‐275 attenuates the inflammatory reaction in rat experimental autoimmune prostatitis
Authors: Zhang Zhi‐Yuan , Schluesener Hermann J.
Published: May 2011

BACKGROUND

Experimental autoimmune prostatitis (EAP) is an autoimmune inflammatory disease of male sex accessory glands and is characterized by a cellular and humoral prostate‐specific autoimmune response. EAP shares important clinical and immunological features with human chronic prostatitis and chronic pelvic pain syndrome. MS‐275, a potent histone deacetylase inhibitor, has promising anti‐inflammatory activities and might be a new agent in the therapy of prostate inflammation.

METHODS

EAP rats were treated with MS‐275 (5 mg/kg, i.p.) once daily. Using immunohistochemistry and PCR assay, we determined immune cellular responses and infiltration into the prostate glands, and changes of mRNA levels of representative inflammatory molecules in prostate tissue. Changes in Foxp3+CD4+ cell populations of lymph nodes and peripheral blood were analyzed by flow cytometry. Additionally, direct anti‐inflammatory effects of MS‐275 were investigated in vitro with a macrophage cell line.

RESULTS

MS‐275 treatment significantly reduced the local accumulation of immune cells and mRNA levels of representative pro‐inflammatory molecules in prostate tissue. Furthermore, MS‐275 treatment increased percentage of Foxp3+CD4+ Treg cells in lymph nodes and their proportion to CD4+ cells in peripheral blood, and induced a relative increase of ED2+ macrophage numbers in EAP prostate. Additional in vitro study showed that MS‐275 induced a switch of macrophages from classic M1 to anti‐inflammatory M2 phenotype.

CONCLUSIONS

In summary, our data demonstrated that MS‐275 could effectively suppress inflammatory reaction in EAP, through suppressing immune cells and pro‐inflammatory molecules, and inducing anti‐inflammatory immune cells and molecules, which may suggest MS‐275 as a potential candidate for treatment of inflammatory prostatitis. Prostate 72:90–99, 2012. © 2011 Wiley Periodicals, Inc.
Imaging prostate cancer lymph node metastases with a multimodality contrast agent
Authors: Hall Mary A. , Kwon Sunkuk , Robinson Holly , Lachance Pier‐Anne , Azhdarinia Ali , Ranganathan Ranjani , Price Roger E. , Chan Wenyaw , Sevick‐Muraca Eva M.
Published: May 2011

BACKGROUND

Methods to detect lymph node (LN) metastases in prostate cancer (PCa) are limited. Pelvic LN dissection is commonly performed during prostatectomy, but often followed by morbid complications. More refined methods for detecting LN invasion are needed.

METHODS

We developed a dual‐labeled targeting agent having a near‐infrared (NIR) fluorophore for intraoperative guidance, and a conventional radiotracer for detection of LN metastasis. Nu/Nu mice were orthotopically implanted with DsRed‐expressing human PCa (PC3) cells. Antibody (Ab) specific for epithelial cell adhesion molecule was conjugated to DOTA, IRDye 800CW, and radiolabeled with 64Cu. Dual‐labeled Ab was administered intravenously at 10–12 weeks post‐implantation, and positron emission tomography/computed tomography (PET/CT) and fluorescence imaging were performed within 18–24 hr.

RESULTS

Metastasis to lumbar LNs was detected by DsRed fluorescence imaging, as well as pathology, in 75% of mice having pathology‐confirmed primary prostate tumors. These metastases were also detected by NIR fluorescence imaging. In some cases, metastases to sciatic, medial, renal, and axillary nodes were also detected. For all LNs examined, no significant differences were found between the percentages of metastases detected by NIR imaging (63%) and µPET/CT (64%) (P = 0.93), or between those detected by DsRed imaging (25%) and pathological examination (19%) (P = 0.12).

CONCLUSION

This study demonstrates that a multimodality contrast agent is useful for early detection of metastatic disease, and has applications for intraoperative PCa treatment. Further agent optimization is necessary to enhance specificity, and provide validation for prostate and other LN metastasizing epithelial cancers. Prostate 72:129–146, 2012. © 2011 Wiley Periodicals, Inc.
Early onset prostate cancer has a significant genetic component
Authors: Lange Ethan M. , Salinas Claudia A. , Zuhlke Kimberly A. , Ray Anna M. , Wang Yunfei , Lu Yurong , Ho Lindsey A. , Luo Jingchun , Cooney Kathleen A.
Published: May 2011

BACKGROUND

Prostate cancer (PCa) affects more than 190,000 men each year with ∼10% of men diagnosed at ≤55 years, that is, early onset (EO) PCa. Based on historical findings for other cancers, EO PCa likely reflects a stronger underlying genetic etiology.

METHODS

We evaluated the association between EO PCa and previously identified single nucleotide polymorphisms (SNPs) in 754 Caucasian cases from the Michigan Prostate Cancer Genetics Project (mean 49.8 years at diagnosis), 2,713 Caucasian controls from Illumina's iControlDB database and 1,163 PCa cases diagnosed at >55 years from the Cancer Genetic Markers of Susceptibility Study (CGEMS).

RESULTS

Significant associations existed for 13 of 14 SNPs (rs9364554 on 6q25, rs10486567 on 7p15, rs6465657 on 7q21, rs6983267 on 8q24, rs1447295 on 8q24, rs1571801 on 9q33, rs10993994 on 10q11, rs4962416 on 10q26, rs7931342 on 11q13, rs4430796 on 17q12, rs1859962 on 17q24.3, rs2735839 on 19q13, and rs5945619 on Xp11.22, but not rs2660753 on 3p12). EO PCa cases had a significantly greater cumulative number of risk alleles (mean 12.4) than iControlDB controls (mean 11.2; P = 2.1 × 10−33) or CGEMS cases (mean 11.9; P = 1.7 × 10−5). Notably, EO PCa cases had a higher frequency of the risk allele than CGEMS cases at 11 of 13 associated SNPs, with significant differences for five SNPs. EO PCa cases diagnosed at <50 (mean 12.8) also had significantly more risk alleles than those diagnosed at 50–55 years (mean 12.1; P = 0.0003).

CONCLUSIONS

These results demonstrate the potential for identifying PCa‐associated genetic variants by focusing on the subgroup of men diagnosed with EO disease. Prostate 72:147–156, 2012. © 2011 Wiley Periodicals, Inc.
Alternol exerts prostate‐selective antitumor effects through modulations of the AMPK signaling pathway
Authors: Yeung Eddie D. , Morrison Alex , Plumeri Daniel , Wang Jingying , Tong Chao , Yan Xiaoyan , Li Ji
Published: May 2011

BACKGROUND

Alternol is an original compound purified from the fermentation products of Alternaria alternata var. monosporus, a microorganism from the bark of the yew tree. It has been reported that Alternol can inhibit proliferation of mouse leukemia cells and human gastric carcinoma cells, the aim of this study was to investigate the effects of Alternol on prostate cancer cells in comparison to prostate cells.

METHODS

The MTT assay was utilized to assess cell viability. Cell cycle was analyzed by flow cytometry with propidium iodide staining. Protein expression levels were examined by Western blotting.

RESULTS

Alternol treatment resulted in a significant decrease in the viability of prostate cancer cells but had lesser effects on prostate cells. Alternol inhibited AMP‐activated protein kinase (AMPK) phosphorylation in prostate cancer C4‐2 cells but stimulated AMPK phosphorylation in prostate RWPE‐1 cells. Inhibition of p27 phosphorylation was observed in C4‐2 cells whereas a promotion of p27 phosphorylation was seen in RWPE‐1 cells. Alternol treatment resulted in a profound increase in the LC3II/LC3I protein ratio in RWPE‐1 cells but not in C4‐2 cells. A dose‐dependent down‐regulation of Bcl‐2 protein was detected in C4‐2 cells but not in RWPE‐1 cells. Pretreatment of cells with Compound C (AMPK inhibitor) before Alternol treatment abolished the selective antitumor effect of Alternol.

CONCLUSIONS

These results reveal for the first time that Alternol exerts a selective antitumor effect on prostate cancer cells when compared with RWPE‐1 prostate epithelial cells. In addition, the AMPK signaling pathway is responsible for the selective antitumor effects of Alternol. Prostate 72:165–172, 2012. © 2011 Wiley Periodicals, Inc.
Conserved conformational dynamics of membrane fusion protein transmembrane domains and flanking regions indicated by sequence statistics
Authors: Neumann Sindy , Langosch Dieter
Published: May 2011

SNARE proteins and fusogenic viral membrane proteins represent the major classes of integral membrane proteins that mediate fusion of eukaryotic lipid bilayers. Although both classes have different primary structures, they share a number of basic architectural features. There is ample evidence that the fusogenic function of representative fusion proteins is influenced by the primary structure of the single transmembrane domain (TMD) and the region linking it to the soluble assembly domains. Here, we used comprehensive non‐redundant datasets to examine potential over‐ and underrepresentation of amino acid types in the TMDs and flanking regions relative to control proteins that share similar biosynthetic origins. Our results reveal conserved overall and/or site‐specific enrichment of β‐branched residues and Gly within the TMDs, underrepresentation of Gly and Pro in regions flanking the TMD N‐terminus, and overrepresentation of the same residue types in C‐terminal flanks of SNAREs and viral fusion proteins. Furthermore, the basic Lys and Arg are enriched within SNARE N‐terminal flanking regions. These results suggest evolutionary conservation of key structural features of fusion proteins and are discussed in light of experimental findings that link these features to the fusogenic function of these proteins. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Challenges in developing and implementing safety risk tolerance criteria
Authors: P.E. Walt Frank
Published: May 2011

Risk quantification can help in understanding and managing risk. Establishing quantitative risk criteria can be a key component to risk decision‐making and many companies use such criteria, either formally or informally. The Center for Chemical Process Safety issued its guidance on developing quantitative safety risk criteria in 2009—Center for Chemical Process Safety Guidelines for Developing Quantitative Safety Risk Tolerance Criteria. This article addresses some of the more common challenges that users may face in developing and implementing safety risk tolerance criteria as they apply the Guidelines. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
High integrity protective system design using a risk‐based approach
Authors: Stack Robert J. , Armstrong John , Eure Don , Johnson Ron , Tipler Scott , Wagner Tim , Werkmeister Sofka
Published: May 2011

In 2007, API 521/ISO 23251 [AANSI/API Standard 521, Petroleum and Natural Gas Industries Pressure‐Relieving and Depressuring Systems, 2007] published guidance on the use of high integrity protective systems (HIPS). The Dow Chemical Company (Dow) updated its internal work process to apply Dow's risk‐based work processes to HIPS design, application, and evaluation. Rather than just focusing on the vessel‐related consequences of substituting a HIPS for a pressure relief device (PRD), the work process calls for stepping back and looking at the overall scenario and all the potential consequence outcomes. Using a risk‐based methodology requires looking at a much wider consequence potential than what Dow has traditionally focused on for the design of relief systems.

By using a very robust layer of protection analysis (LOPA) process to evaluate the consequences of the overpressure scenarios and to determine the consequence severity factor or LOPA target factor for each scenario (Dow has seven levels), the wider range of consequences is covered. The HIPS safety integrity level (SIL) is determined by the highest risk scenario, which is typically the scenario with the greatest LOPA consequence severity factor. The resulting SIL level for the HIPS is adjusted to close the HIPS scenario risk gap. Other applicable LOPA independent protection layers (IPLs) included in the LOPA HIPS scenario risk evaluation are validated. The HIPS design is verified by calculation to meet the required SIL level.

There are PRD services for which PRDs cannot deliver the overpressure protection that Dow needs and expects. The updated work process also identifies key opportunities for using a HIPS when: a conventional PRD is not practical or possible, a conventional PRD will not be reliable or a conventional PRD will work but will result in high treatment cost. Each of these three opportunities is discussed.

The overall result is an efficient process that links together the existing work processes for conventional relief design, LOPA, and safety instrumented systems. This produces a risk‐based method for applying and designing protection layers into a HIPS. This article gives an overview of this work process with some application examples and describes how this work process is used to improve safety while reducing risks and potentially reducing costs. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
Soil microbial degradation of neonicotinoid insecticides imidacloprid, acetamiprid, thiacloprid and imidaclothiz and its effect on the persistence of bioefficacy against horsebean aphid Aphis craccivora Koch after soil application
Authors: Liu Zhonghua , Dai Yijun , Huang Guodong , Gu Yuyu , Ni Jueping , Wei Hua , Yuan Sheng
Published: May 2011

BACKGROUND: The neonicotinoids imidacloprid, imidaclothiz, acetamiprid and thiacloprid consist of similar structural substituents but differ considerably with respect to soil use. Therefore, the effects of soil microbial activity on the degradation and bioefficacy persistence of the four neonicotinoids were evaluated.

RESULTS: In unsterilised soils, 94.0% of acetamiprid and 98.8% of thiacloprid were degraded within 15 days, while only 22.5% of imidacloprid and 25.1% of imidaclothiz were degraded over a longer period of 25 days. In contrast, in sterilised soils, the degradation rates of acetamiprid and thiacloprid were respectively only 21.4% and 27.6%, whereas the degradation rates of imidaclothiz and imidacloprid were respectively 9.0% and almost 0% within 25 days. The degradation products of imidacloprid and imidaclothiz were identified as olefin, nitroso or guanidine metabolites, the degradation product of thiacloprid was identified as an amide metabolite and no degradation product of acetamiprid was detected. A bioefficacy assay revealed that the bioefficacy and persistence of imidacloprid, imidaclothiz, acetamiprid and thiacloprid against horsebean aphid A. craccivora were related to their degradation rate and the bioefficacy of their degradation products in soil.

CONCLUSION: Soil microbial activity played a key role in the bioefficacy persistence of neonicotinoid insecticides and therefore significantly affected their technical profile after soil application. Copyright © 2011 Society of Chemical Industry
Insecticide resistance in field populations of Asian citrus psyllid in Florida
Authors: Tiwari Siddharth , Mann Rajinder S , Rogers Michael E , Stelinski Lukasz L
Published: May 2011

BACKGROUND: Asian citrus psyllid (ACP), Diaphorina citri, is a major pest of citrus because it vectors the putative causal agent of huanglongbing disease. Insecticides are currently the basis of psyllid management programs, and the number of annual insecticide applications has increased significantly. In this paper, a series of investigations of insecticide resistance among field populations of adult and immature ACP in Florida is described.

RESULTS: In 2009, the highest level of resistance for adult ACP, as compared with the laboratory susceptible (LS) population, was found with imidacloprid with an LD50 resistance ratio (RR50) of 35 in one population. This was followed by chlorpyriphos (RR50 = 17.9, 13.3, 11.8 and 6.9), thiamethoxam (RR50 = 15 and 13), malathion (RR50 = 5.4 and 5.0) and fenpropathrin (RR50 = 4.8). In 2010, mortality of adults from all five sites sampled was lower than with the LS population at three diagnostic concentrations of each insecticide tested. Among nymph populations, indications of resistance were observed with carbaryl (RR50 = 2.9), chlorpyriphos (RR50 = 3.2), imidacloprid (RR50 = 2.3 and 3.9) and spinetoram (RR50 = 4.8 and 5.9). General esterase, glutathione S‐transferase and monooxygenase levels were also elevated in field‐collected adult and nymph ACP as compared with the LS population.

CONCLUSION: The present results suggest that varying levels of insecticide susceptibility exist in ACP populations across the citrus‐growing areas of Florida. Increased levels of detoxifying enzymes in these populations may partially explain these differences. The present results indicate that insecticide resistance may become an emerging problem for ACP control if effective resistance management is not practiced. Copyright © 2011 Society of Chemical Industry
F2 screening for resistance to pyramided Bacillus thuringiensis maize in Louisiana and Mississippi populations of Diatraea saccharalis (Lepidoptera: Crambidae)
Authors: Huang Fangneng , Ghimire Mukti N , Leonard Billy R , Wang Jing , Daves Chris , Levy Ronnie , Cook Don , Head Graham P , Yang Yunlong , Temple Josh , Ferguson Rob
Published: May 2011

BACKGROUND: In the mid‐southern region of the United States, sugarcane borer, Diatraea saccharalis (F.), is a major target pest of transgenic maize expressing Bacillus thuringiensis (Bt) proteins. Novel transgenic maize technologies containing two or more pyramided Bt genes for controlling lepidopteran pests have recently become commercially available. Insect resistance management (IRM) is an important issue in the sustainable use of Bt crop technologies. The objective of this study was to determine the frequency of resistance alleles in field populations of D. saccharalis to the new pyramided Bt maize technologies.

RESULTS: A total of 382 F2 family lines derived from 735 feral larvae/pupae of D. saccharalis collected from six locations in Louisiana and Mississippi during 2008 and 2009 were screened for resistance to three new Bt maize technologies: MON 89034, Genuity™ VT Triple Pro™ and SmartStax™. None of the 382 F2 isoline families survived on the Bt maize leaf tissue for ≥ 12 days in the F2 screen. The joint frequency for two‐ or three‐gene resistance models with 95% probability in these populations was estimated to be < 0.0063 to MON 89034 and < 0.003 to VT Triple Pro™ and SmartStax™.

CONCLUSION: These results suggest that the resistance allele frequency in D. saccharalis to the three pyramided Bt maize technologies is low in the mid‐southern region of the United States, which should meet the rare resistance assumption of the currently used IRM strategy for Bt maize. Copyright © 2011 Society of Chemical Industry