bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Cytotoxicity Evaluation of Novel Podophyllotoxin Derivatives
Authors: Chengniu Wang , Zhonghua Wu , Yu Zhao , Chunyan Ni , Xiaodong Zhao , Li Zhu
Published: September 2011

Seven benzylamino derivatives of podophyllotoxin 8a–8g were synthesized and their chemical structures were confirmed by IR, 1H‐NMR, 13C‐NMR and ESI‐MS spectral analyses. Their abilities to inhibit the growth of cancer cells A549, HCT‐116 and HepG2, were investigated by MTT assay. Compound 8b possessed the highest cytotoxicity on cancer cell lines with average IC50 values of 3.8 µM. All we synthetic compounds were cytotoxic against three cancer cell lines at the micromolar range, indicating podophyllotoxin derivatives with structural modification of benzylamino possess potent antitumor activity.
Steroid/Triterpenoid Functional Molecules based on “Click Chemistry”
Authors: Hu J. , Lu J. R. , Ju Y.
Published: September 2011

This Focus Review highlights the design and synthesis of various functional molecules based on steroid/triterpenoid as building blocks through the copper‐catalyzed azide–alkyne cycloaddition (CuAAC) “click” reaction, as well as their applications in bioactivity, recognition, and assembly. This method shows great promise to allow us to develop novel molecules with characteristic functions using the CuAAC “click” reaction.
Reactions under the Click Chemistry Philosophy Employed in Supramolecular and Mechanostereochemical Systems
Authors: Fahrenbach Albert C. , Stoddart J. Fraser
Published: September 2011

Supramolecular chemistry and mechanostereochemistry have been major beneficiaries of the concepts and reactions pioneered under the “click chemistry” philosophy. The success of the copper(I) 1,3‐dipolar cycloaddition between azides and alkynes, resulting in the triazole ring has inspired the application of other emerging click reactions, for example, Diels–Alder cycloadditions, thiol–ene/yne chemistry, and nitrile N‐oxide cycloadditions, towards the creation of advanced functional supramolecular and mechanostereochemical systems. In this Focus Review, recent advances in the use of click chemistry in these fields are highlighted.
Applying Small Molecule Microarrays and Resulting Affinity Probe Cocktails for Proteome Profiling of Mammalian Cell Lysates
Authors: Shi Haibin , Uttamchandani Mahesh , Yao Shao Q.
Published: September 2011

Small molecule microarrays (SMMs) are proving to be increasingly important tools for assessing protein–ligand interactions, as well as in screening for enzyme substrates and inhibitors, in a high‐throughput manner. We previously described an SMM‐facilitated screening strategy for the rapid identification of probes against γ‐secretase, an aspartic protease. In this article, we extend upon this work with an expanded library of hydroxyethylamine‐derived inhibitors which non‐exclusively target aspartic proteases. Our library is diversified across P2, P1, P1’, and P2’ positions. Accordingly, 86 new inhibitors are synthesized using a combinatorial, solid‐phase synthetic approach, bringing the total library size to 284‐biotinylated compounds, which were arrayed onto avidin slides. In order to elucidate enzymatic activity and profiles within complex biological samples, screening is performed using fluorescently‐labeled mammalian cell lysates. This yielded reproducible profiles or binding fingerprints that correspond with interactions from aspartic proteases or accessory proteins as well as other interacting targets that were present in the sample. The brightest microarray hits were converted to affinity‐based probes (AfBPs) using convenient, 1‐step “click” chemistry with benzophenone from the relevant building blocks. Pull‐down/mass spectrometric analysis with these probes (individuals or cocktail) yielded putative protein targets that include well‐known aspartic proteases, such as cathepsin D which is a clear marker for breast cancer cell lines, T47D. Many other hits were also identified, which may be secondary or tertiary interactors of aspartic proteases, or yet unreported off‐targets of the hydroxyethylamine pharmacophore. Our work herein thus provides a candidate list of biomarkers for further investigations. Taken together, this SMM‐facilitated strategy for the discovery of new AfBPs should provide a useful tool for high‐throughput development of novel small molecule probes and the identification of new aspartic proteases as well as related biomarkers in the future.
Analyse des Trag‐ und Verformungsverhaltens einer Gruppe geokunststoffummantelter Säulen im Großversuch
Authors: Raithel Marc , Werner Sandra , Küster Volker , Alexiew Dimiter
Published: September 2011

Das Gründungssystem “Geokunststoffummantelte Säulen“ (auch GEC Geotextile Encased Columns genannt) für Erdbauwerke auf gering tragfähigen Böden ist in Deutschland nach seiner Einführung vor ca. 15 Jahren mittlerweile Stand der Technik. Die aktuellen Empfehlungen für Bewehrungen aus Geokunststoffen (EBGEO 2010) der DGGT enthalten sowohl die entsprechenden Berechnungs‐ und Bemessungsverfahren als auch konstruktive und technologische Hinweise. Die praktischen Erfahrungen zeigen jedoch zunehmend, dass gegenüber der Berechnung noch Tragreserven vorliegen. Mittels eines Großversuchs sollten die Grenzzustände und Systemgrenzen weiter untersucht werden. Es wird auf die ersten wichtigsten Ergebnisse und Auswertungen eingegangen sowie mögliche modifizierte Vorgehensweisen bei der Systemberechnung tendenziell aufgezeigt.

Analysis of bearing behaviour and deformations of geotextile encased columns in a large‐scale test. The foundation system Geotextile Encased Columns (GEC) for embankments on soft subsoil started in Germany about 15 years ago and has become state‐of‐the‐art. The recent German Code for design of geosynthetic reinforced soil systems (EBGEO 2010) of the German Geotechnical Society comprises design and dimensioning procedures and provides useful recommendations regarding concepts and construction as well. Based on the permanently increasing practical experience, it seems that the system has higher bearing resources than formally calculated. A 1 : 1 field test was designed “on the edge” in order to provoke a limit state of the system and to identify its “upper limits”. The most important first test results are shown, evaluated and commented and possible tendencies for modifications regarding some design and calculation aspects are explained.
Textilbetonverstärkte Stahlbetonstützen
Authors: Ortlepp Regine , Schladitz Frank , Curbach Manfred
Published: September 2011

Nachdem Untersuchungen an Stützenköpfen unterschiedlicher Geometrie gezeigt haben, dass mit textilbewehrtem Beton eine beachtliche Verstärkungswirkung von Stützen erzielt werden kann, ging es darum, die Gültigkeit der hierfür entwickelten Rechenmodelle an Großversuchen zu überprüfen. Zur Berechnung stahlbewehrter Stützen mit realistischen Bauteilabmessungen wurde hierzu das anhand von kleinteiligen Versuchen an unbewehrten Betonstützen entwickelte Modell weiterentwickelt. Die Vorhersagegenauigkeit wurde anhand von drei Stahlbetonstützen mit rundem Querschnitt experimentell untersucht. Die Tragfähigkeit der mit Textilbeton verstärkten Stützen nahm im Vergleich zur Referenzstütze deutlich zu. Die Versuchsergebnisse zeigen, dass die erreichbaren Traglasten mit dem weiterentwickelten Umschnürungsmodell sehr gut abgeschätzt werden können. Neben einer Steigerung der Tragfähigkeit ergibt sich durch die textilbewehrte Verstärkung eine Verbesserung des Vorankündigungsverhaltens. Insgesamt wurde eine große Duktilität der verstärkten Stützen erreicht.

TRC strengthened RC Columns

After research on differently shaped column heads has shown the considerable strengthening effect of textile reinforced concrete (TRC), we aimed to verify the validation of the developed calculation models in large scale tests. The model, which was developed on the basis of plain concrete columns in small scale experiments, was therefore enhanced. How accurate the predictions of the model for reinforced large scale columns were was examined by large scale testings at three reinforced concrete columns with round cross sections. The bearing capacity of the TRC strengthened columns increased considerably in comparison with the reference's. The achieved ultimate loads had been estimated very well by the developed confinement model. Besides an increase of the ultimate load the textile reinforcement also led to a considerably improved prior warning behaviour. During the load increase fine and later well visible and, homogeneously distributed cracks occurred. All in all we have reached a high ductility of the reinforced columns.
Plastische Berechnungsverfahren: Formeln und Diagramme für Rechteckplatten
Authors: Friedrich Richard
Published: September 2011

Die neuen Normen erlauben, auch bei der Ermittlung der Schnittgrößen – wie schon bei der Querschnittsbemessung – das plastische Verhalten des Stahlbetons zu berücksichtigen. Dabei unterscheidet man zwischen kinematischen und statischen Verfahren zur Bestimmung oberer und unterer Schranken der Tragfähigkeit. Nach einer einführenden Darstellung der statischen Berechnungen im elastischen und im plastischen Bereich werden Formeln und – beispielhaft – Diagramme für vier‐, drei‐ und zweiseitig gelagerte Rechteckplatten unter Gleichlast angegeben. Zum Einsatz kommt die Bruchlinientheorie, ein kinematisches plastisches Verfahren, das bei gut gewählten Bruchfiguren ausreichend sichere Ergebnisse liefert. Es folgen Berechnungsbeispiele für Platten und Hinweise auf weitere Einsatzmöglichkeiten der Schnittgrößenermittlung im plastischen Bereich.

Plastic analysis and design: Formulas and diagrams for rectangular slabs

The new codes allow to determine the sectional efforts taking into consideration the plastic behaviour of reinforced concrete – as for the design of cross sections. The kinematic and the static procedures give upper and lower bounds of the load carrying capacity. After an introductory presentation of the static treatment in the elastic and in the plastic domain, formulas and – exemplary – diagrams for rectangular slabs with supports on four, three and two sides under uniformly distributed loads are presented. The yield‐line method, a kinematic plastic procedure is utilized, which gives sufficient safe results – with well selected fail geometries. Numerical examples for various slabs and references to other possibilities of obtaining sectional efforts in the plastic domain complete the paper.
The significant rectal neoplasm and mucosectomy by transanal endoscopic microsurgery (Br J Surg 2011; 98: 1342–1344)
Authors: Barendse R M , Fockens P , Bemelman W A , de Graaf E J R , Dekker E
Published: September 2011

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (http://www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Activity, Stability, and Degradation Mechanisms of Dealloyed PtCu3 and PtCo3 Nanoparticle Fuel Cell Catalysts
Authors: Hasché Frédéric , Oezaslan Mehtap , Strasser Peter
Published: September 2011

A key challenge in today’s fuel cell research is the understanding and maintaining the durability of the structure and performance of initially highly active Pt fuel cell electrocatalysts, such as dealloyed Pt or Pt monolayer catalysts. Here, we present a comparative long‐term stability and activity study of supported dealloyed PtCu3 and PtCo3 nanoparticle fuel cell catalysts for the oxygen reduction reaction (ORR) and benchmark them to a commercial Pt catalyst. PtCu3 and PtCo3 were subjected to two distinctly different voltage cycling tests: the “lifetime” regime [10 000 cycles, 0.5–1.0 V vs. RHE (reversible hydrogen electrode), 50 mV s−1] and the corrosive “start‐up” regime (2000 cycles, 0.5–1.5 V vs. RHE, 50 mV s−1). Our results highlight significant activity and stability benefits of dealloyed PtCu3 and PtCo3 for the ORR compared with those of pure Pt. In particular, after testing in the “lifetime” regime, the Pt‐surface‐area‐based activity of the Pt alloy catalysts is still two times higher than that of pure Pt. From our electrochemical, morphological, and compositional results, we provide a general picture of the temporal sequence of dominant degradation mechanisms of a Pt alloy catalyst during its life cycle.
Stereoselective Synthesis of Trisubstituted Olefins by a Directed Allylic Substitution Strategy
Authors: Schmidt Yvonne , Breit Bernhard
Published: September 2011

New methodology for the stereoselective synthesis of trisubstituted olefins is presented. The use of ortho‐diphenylphosphanyl benzoate (o‐DPPB) as a directing leaving group for copper‐mediated allylic substitution with Grignard reagents allowed for the stereoselective construction of a wide range of E olefins, without the need for an adjacent electron‐withdrawing group. Our modular three‐step approach toward trisubstituted alkenes commenced with geminal α‐methylene aldehydes. Addition of an organometallic reagent and introduction of the o‐DPPB group by esterification was followed by the o‐DPPB‐directed copper‐mediated allylic substitution with a Grignard reagent to furnish stereodefined trisubstituted olefins. Additionally, incorporation of a stereocenter from the chiral pool allowed the preparation of an enantiomerically pure olefin that bore three alkyl substituents in high E/Z selectivity.
Negishi Cross‐Coupling Reactions Catalyzed by an Aminophosphine‐Based Nickel System: A Reliable and General Applicable Reaction Protocol for the High‐Yielding Synthesis of Biaryls
Authors: Gerber Roman , Frech Christian M.
Published: September 2011

Treatment of NMP solutions of NiCl2 with 1,1′,1′′‐(phosphanetriyl)tripiperidine (≈2.05 equiv), dissolved in THF, in air at 25 °C forms a highly active catalytic system for the cross‐coupling of a large variety of electronically activated, non‐activated, deactivated, and ortho‐substituted, heterocyclic, and functionalized aryl bromides and aryl chlorides with diarylzinc reagents. Very high levels of conversion and yields were obtained within 2 h at 60 °C in the presence of only 0.1 mol % of catalyst (based on nickel) and thus at catalyst loadings far lower than typically reported for nickel‐catalyzed versions of the Negishi reaction. Various aryl halides—which may contain trifluoromethyl groups, fluorides, or other functional groups such as acetals, ketones, ethers, esters, lactones, amides, imines, anilines, alkenes, pyridines, quinolines, and pyrimidines—were successfully converted into the corresponding biaryls. Electronic and steric variations are tolerated in both reaction partners. Experimental observations indicate that a molecular (NiI/NiIII) mechanism is operative.
Surface‐Modified Protein Microspheres Capture Amyloid‐β and Inhibit its Aggregation and Toxicity
Authors: Richman Michal , Wilk Sarah , Skirtenko Natalia , Perelman Alex , Rahimipour Shai
Published: September 2011

The biocompatible and biodegradable properties of protein microspheres and the recent advances in their preparation have generated considerable interest of utilizing these core‐shell structures for drug delivery and diagnostic applications. However, effective targeting of protein microspheres to desirable cells or loci still remains a challenge. Here, we describe for the first time a facile one‐pot sonochemical approach for covalent modification of protein microspheres made from serum albumin; the surface of which is covalently decorated with a short recognition peptide to target amyloid‐β (Aβ) as the main pathogenic protein in Alzheimer’s disease (AD). The microspheres were characterized for their morphology, size, and entrapment efficacy by electron microscopy, dynamic light scattering and confocal microscopy. Fluorescence‐activated cell‐sorting analysis and Thioflavin‐T binding assay demonstrated that the conjugated microspheres bind with high affinity and selectivity to Aβ, sequester it from the medium and reduce its aggregation. Upon incubation with Aβ, the microspheres induced formation of amorphous aggregates on their surface with no apparent fibrillar structure. Moreover, the microspheres directly reduced the Aβ‐induced toxicity toward neuron like PC12 cells. The conjugated microspheres are smaller than unmodified microspheres and remained stable throughout the incubation under physiological conditions.
A Combined Far‐Infrared Spectroscopic and Electrochemical Approach for the Study of Iron–Sulfur Proteins
Authors: El Khoury Youssef , Hellwig Petra
Published: September 2011

Herein, we present the development of a far‐infrared spectroscopic approach for studying metalloenzyme active sites in a redox‐dependent manner. An electrochemical cell with 5 mm path and based on silicon windows was found to be appropriate for the measurement of aqueous solutions down to 200 cm−1. The cell was probed with the infrared redox signature of the metal–ligand vibrations of different iron–sulfur proteins. Each FeS cluster type was found to show a specific spectral signature. As a common feature, a downshift of the frequency of the FeS vibrations was seen upon reduction, in line with the increase of the FeS bond. This downshift was found to be fully reversible. Electrochemically induced FTIR difference spectroscopy in the far infrared is now possible, opening new perspectives on the understanding of metalloproteins in function of the redox state.
Characterization of transgenic mice expressing cancer‐associated variants of human NOTCH1
Authors: Berquam‐Vrieze Katherine E. , Swing Deborah A. , Tessarollo Lino , Dupuy Adam J.
Published: September 2011

The Notch1 receptor plays a critical role in cell fate decisions during development. Activation of Notch signaling has been implicated in several types of cancer, particularly T‐cell acute lymphoblastic leukemia (T‐ALL). Consequently, several transgenic mouse strains have been made to study the role of Notch1 in T‐ALL. However, the existing Notch1 transgenic lines mimic a translocation event found in only ∼ 1% of T‐ALL cases. Here we describe three novel NOTCH1 transgenic mouse strains that have Cre‐inducible expression of the entire human NOTCH1 locus, each possessing a common mutation found in T‐ALL. Unlike existing Notch1 transgenic strains, these NOTCH1 transgenic strains express full‐length receptors from anendogenous human promoter that should be susceptible to a number of Notch antagonists that have recently been developed. These strains will allow researchers to modulate Notch signaling to study bothnormal development and cancer biology. genesis 50:112–118, 2012. © 2011 Wiley Periodicals, Inc.
M cells expressing the complement C5a receptor are efficient targets for mucosal vaccine delivery
Authors: Kim Sae‐Hae , Jung Dae‐Im , Yang In‐Young , Kim Ju , Lee Kyung‐Yeol , Nochi Tomonori , Kiyono Hiroshi , Jang Yong‐Suk
Published: September 2011

In the mucosal immune system, M cells are known as specialized epithelial cells that take up luminal antigens, although the receptors on M cells and the mechanism of antigen uptake into M cells are not well‐understood. Here, we report the expression of the complement C5a receptor (C5aR) on the apical surface of M cells.C5armRNA expression in co‐cultured Caco‐2 human M‐like cells was six‐fold higher than in mono‐cultured cells. C5aR expression was detected together with glycoprotein 2, an M‐cell‐specific protein, on the apical surface of M‐like cells and mouse Peyer's patch M cells. Interestingly, after oral administration ofYersinia enterocoliticawhich expresses outer membrane protein H (OmpH) that is homologous to the Skp α1 domain ofEscherichia coli, a ligand of C5aR, dense clustering and phosphorylation of C5aR were detected in M cells. Finally, targeted antigen delivery to M cells using C5aR as a receptor was achieved using the OmpH α1 ofY. enterocoliticasuch that the induction of ligand‐conjugated antigen‐specific immune responses was confirmed in mice after oral immunization of the OmpH β1α1‐conjugated antigen. Collectively, we identified C5aR expression on M cells and suggest that C5aR could be used as a target receptor for mucosal antigen delivery.
A New Series of Nanoporous Ionic Crystals Based on Polyoxometalates – Synthesis, Crystal Structures, and Adsorption Properties
Authors: Han Xiaohui , Xu Lin , Li Fengyan , Jiang Ning
Published: September 2011

Based on polyoxometalate cluster anions and macrocations, KH2[Cr3O(OOCCH3)6(H2O)3][α‐GeMo12O40]·10H2O (1), K1.5H1.5[Cr3O(OOCCH3)6(H2O)3][α‐GeW12O40]·9.5H2O (2), NaH2[Cr3O(OOCCH3)6(H2O)3]3[α‐P2W18O62]·32H2O (3), and Na3[Cr3O(OOCCH3)6(H2O)3]3[α‐As2W18O62]·34H2O (4) have been prepared by a conventional method and characterized by single‐crystal X‐ray diffraction, IR and UV/Vis spectroscopy, elemental analysis, thermogravimetric analysis (TGA) and powder X‐ray diffraction (PXRD). In addition, the gas adsorption properties of these four compounds for methanol and ethanol have been investigated. The adsorption studies display an apparent difference between methanol and ethanol vapor adsorption and demonstrate that such microporous materials could be applied as new molecular sieves for selective sorption from a mixture of C1 and C2 alcohols.
Photocatalytic H2 and Added‐Value By‐Products – The Role of Metal Oxide Systems in Their Synthesis from Oxygenates
Authors: Cargnello Matteo , Gasparotto Alberto , Gombac Valentina , Montini Tiziano , Barreca Davide , Fornasiero Paolo
Published: September 2011

The growing demand for hydrogen for industrial use and as a fuel pushes for innovative and sustainable production strategies, which can be applied both in centralized, large‐scale plants and in delocalized small units. At present, hydrogen is mainly produced by steam reforming of natural gas or oil. Nevertheless, the shortage of fossil fuel reserves and the increasing concern regarding environmental pollution have stimulated the search for alternative production routes, among which photocatalysis over metal oxide semiconductors represents a strategically attractive solution. Whereas the direct splitting of water is still a challenging issue because of intrinsic process drawbacks, a valuable alternative for a sustainable photocatalytic H2 production is the use of biomass‐derived compounds as raw materials. Upon photoactivation in the presence of an appropriate semiconductor, such feedstocks can undergo oxidation to CO2 with simultaneous H2 production in the so‐called photoreforming process. When the oxidation is selective rather than complete, the process might be of further interest due to the added value of the obtained carbon‐containing by‐products. This microreview focuses on recent developments in this field, with particular attention to the use of representative biomass‐derived oxygenated compounds, such as methanol, ethanol, glycerol, and sugars.
Aerobic biodegradation of a mixture of sulfonated azo dyes by a bacterial consortium immobilized in a two‐stage sparged packed‐bed biofilm reactor
Authors: de los Cobos‐Vasconcelos Daniel , Ruiz‐Ordaz Nora , Galíndez‐Mayer Juvencio , Poggi‐Varaldo Héctor , Juàrez‐Ramírez Cleotilde , Aarón López‐Muñoz
Published: September 2011

The biodegradation of the sulfonated azo dyes, Acid Orange 7 (AO7) and Acid Red 88 (AR88), by a bacterial consortium isolated from water and soil samples obtained from sites receiving discharges from textile industries, was evaluated. For a better removal of azo dyes and their biodegradation byproducts, an aerobically operated two‐stage rectangular packed‐bed biofilm reactor (2S‐RPBR) was constructed. Because the consortium's metabolic activity is affected by oxygen, the effect of the interstitial air flow rate QGI on 2S‐RPBR's zonal values of the oxygen mass transfer coefficient kLa was estimated. In the operational conditions probed in the bioreactor, the kLa values varied from 3 to 60 h−1, which roughly correspond to volumetric oxygen transfer rates, dcL/dt, ranging from 20 to 375 mg O2 L−1h−1. Complete biodegradation of azo dyes was attained at loading rates BV,AZ up to 40 mg L−1d−1. At higher BV,AZ values (80 mg L−1 d−1), dye decolorization and biodegradation of the intermediaries 4‐amino‐naphthalenesulphonic acid (4‐ANS) and 1‐amino‐2‐naphthol (1‐A2N) was almost complete. However, a diminution in COD and TOC removal efficiencies was observed in correspondence to the 4‐aminobenzenesulfonic acid (4‐ABS) accumulation in the bioreactor. Although the oxygen transport rate improved the azo dye mineralization, the results suggest that the removal efficiency of azo dyes was affected by biofilm detachment at relatively high QGI and BV,AZ values. After 225 days of continuous operation of the 2S‐RFBR, eight bacterial strains were isolated from the biofilm attached to the porous support. The identified genera were: Arthrobacter, Variovorax, Agrococcus, Sphingomonas, Sphingopyxis, Methylobacterium, Mesorhizobium, and Microbacterium.
Production of paramylon, a β‐1,3‐glucan, by heterotrophic growth of Euglena gracilis on potato liquor in fed‐batch and repeated‐batch mode of cultivation
Authors: Šantek Bozˇidar , Friehs Karl , Lotz Martin , Flaschel Erwin
Published: September 2011

Recently, it had been shown that Euglena gracilis was able to grow heterotrophically not only on synthetic media, but also on media based on potato liquor. Supplementation with glucose in both cases led to the accumulation of paramylon, a β‐1,3‐glucan. Thus, such a process may yield a valuable product accompanied by the revaluation of an otherwise annoying waste stream of the potato‐starch industry. Actually, process strategies have been evaluated in order to optimise the concentration of paramylon obtained at the end of the cultivation process. Therefore, cultivation processes based on fed‐batch and in particular repeated‐batch strategies have been studied. It is shown that repeated‐batch operation maybe particularly suited for such a process since E. gracilis seems to adapt gradually to the cultivation medium so that the concentration of media components may be increased step by step. Repeated‐batch cultivation of E. gracilis leads to biomass concentrations in access of 20 g/L with a consistent paramylon mass fraction of about 75%. Cultivations have been carried out at an operating temperature of 27.5°C. As had been found earlier already, pH control is not required during cultivation. On the basis of these results it is clear that repeated‐batch cultivation represent a simple and economic way for the production of paramylon by heterotrophic cultivation of E. gracilis.
Enhanced phytase production from Nocardia sp. MB 36 using agro‐residues as substrates: Potential application for animal feed production
Authors: Bajaj Bijender K. , Wani Masood A.
Published: September 2011

Phytases have gathered considerable attention in recent years due to their applications in human and animal nutrition, environmental protection and biotechnology. Phytases were isolated and characterized from a variety of bacteria and fungi but rarely from actinomycetes. In the present study, a Nocardia sp. MB 36, isolated from rice mill waste, was found to be a producer of a thermostable and acid/alkalistable phytase. Optimization of phytase production by Plackett–Burman designed experiments indicated that wheat bran, medium pH, FeSO4 and CaCl2 are the most effective fermentation variables that influence the phytase yield under submerged fermentation. Further optimization of these four variables by using Closed‐Composite‐Design of response surface methodology resulted in enhancement of phytase production by 64.14%. This newly isolated phytase from Nocardia sp. has potentially desirable features for animal feed applications.
The dynamics of T cells during persistent Staphylococcus aureus infection: from antigen‐reactivity to in vivo anergy
Authors: Ziegler Christina , Goldmann Oliver , Hobeika Elias , Geffers Robert , Peters Georg , Medina Eva
Published: September 2011

Staphylococcus aureus is an important human pathogen that can cause long‐lasting persistent infections. The mechanisms by which persistent infections are maintained involve both bacterial escape strategies and modulation of the host immune response. So far, the investigations in this area have focused on strategies used by S. aureus to persist within the host. Here, we used an experimental mouse model to investigate the host response to persistent S. aureus infection. Our results demonstrated that T cells, which are critical for controlling S. aureus infection, gradually lost their ability to respond to antigenic stimulation and entered a state of anergy with the progression of infection towards persistence. The T cell hyporesponsiveness was reverted by co‐stimulation with the phorbol ester PMA, an activator of protein kinase C, suggesting that a failure in the T cell receptor (TCR)‐proximal signalling events underlie the hyporesponsive phenotype. The presence of these anergic antigen‐specific T cells may contribute to the failure of the host immune response to promote sterilizing immunity during persistent S. aureus infection and also offers new possibilities for novel immunotherapeutic approaches.
Comparative toxicity of two glyphosate formulations (original formulation of Roundup® and Roundup WeatherMAX®) to six North American larval anurans
Authors: Fuentes Latice , Moore Lindsay J , Rodgers John H , Bowerman William W , Yarrow Gregory K , Chao Wayne Y
Published: September 2011

The toxicity of two glyphosate formulations (the original formulation of Roundup® and Roundup WeatherMAX®) to six species of North American larval anurans was evaluated by using 96-h static, nonrenewal aqueous exposures. The 96-h median lethal concentration values (LC50) ranged from 1.80 to 4.22 mg acid equivalent (ae)/L and 1.96 to 3.26 mg ae/L for the original formulation of Roundup and Roundup WeatherMAX, respectively. Judged by LC50 values, four species were more sensitive to Roundup WeatherMAX exposures, and two species were more sensitive to the original formulation. Two of six species, Bufo fowleri (p < 0.05, F = 14.89, degrees of freedom [df] = 1) and Rana clamitans (p < 0.05, F = 18.46, df = 1), had significantly different responses to the two formulations tested. Increased sensitivity to Roundup WeatherMAX likely was due to differences in the surfactants or relative amounts of the surfactants in the two formulations. Potency slopes for exposures of the original formulation ranged from 24.3 to 92.5% mortality/mg ae/L. Thresholds ranged from 1.31 to 3.68 mg ae/L, showing an approximately three times difference in the initiation of response among species tested. For exposures of Roundup WeatherMAX, slopes ranged from 49.3 to 84.2% mortality/mg ae/L. Thresholds ranged from 0.83 to 2.68 mg ae/L. Margins of safety derived from a simulated direct overspray were above 1, except for one species in exposures of Roundup WeatherMAX. Laboratory data based on aqueous exposures are conservative because of the lack of environmental ligands; however, these tests provide information regarding the relative toxicity between these two Roundup formulations. Environ. Toxicol. Chem. 2011;30:2756–2761. © 2011 SETAC
Current-use pesticide transport to Costa Rica's high-altitude tropical cloud forest
Authors: Shunthirasingham Chubashini , Gouin Todd , Lei Ying D , Ruepert Clemens , Castillo Luisa E , Wania Frank
Published: September 2011

To gain insight into the atmospheric transport and deposition of organic contaminants in high-altitude forests in the humid tropics, pesticides were analyzed in air, water, and soil samples from Costa Rica. Passive samplers deployed across the country revealed annually averaged air concentrations of chlorothalonil, endosulfan, and pendimethalin that were higher in areas with intensive agricultural activities than in more remote areas. Atmospheric concentrations were particularly high in the intensively cultivated central valley. Only endosulfan and its degradation products were found in soils sampled along an altitudinal transect on the northern side of Volcano Turrialba, which is facing heavily cultivated coastal plains. Consistent with calculations of cold trapping in tropical mountains, concentrations of endosulfan sulfate increased with altitude. Pesticide levels in lake, creek, fog, and arboreal water samples from high-elevation cloud forests were generally below 10 ng · L−1. Endosulfan sulfate was the most abundant pesticide in water, with concentrations ranging from 0.4 to 9.4 ng · L−1. Its levels were highest in water sampled from bromeliads. Levels of total endosulfan in water are much lower than the reported median lethal concentration (LC50) value for acute toxicity of α-endosulfan to tadpoles. Although this suggests that the presence of pesticide might not have a direct impact on amphibian populations, the possibility of effects of chronic exposure to a mixture of substances cannot be excluded. Fog was relatively enriched in some of the analyzed pesticides, such as dacthal and chlorothalonil, and may constitute an important deposition pathway to high-altitude tropical cloud forest. Environ. Toxicol. Chem. 2011;30:2709–2717. © 2011 SETAC
Passion Late Middle Ages
Authors: August Kristine
Published: September 2011

Between Cambridge and Heidelberg: Historian Jörg Peltzer has a European outlook – both in his research into princely elites and in his academic career
Calculations on greenhouse gas emissions from geotechnical construction processes
Authors: v. Wintzingerode Wilko , Zöhrer Alexander , Bell Alan , Gisselmann Quentin
Published: September 2011

No standards covering greenhouse gas (GHG) emission calculations caused by construction processes have been developed so far. This work makes a proposal for the calculation of greenhouse gas emissions originating from geotechnical works. This proposal is based on the standards ISO 14040 and ISO 14044. It shows a universal and flexible approach applicable for all kinds of geotechnical works and allows a reliable estimation of the greenhouse gas emissions. Finally, example calculations of two foundation methods (bored piles and vibro stone columns) of a project show the impact of the raw materials used to the total emission sum, leading to a massive reduction of greenhouse gas emissions with the vibro stone solution compared to the bored pile solution emissions.

Berechnung der Treibhausgasemissionen bei Spezialtiefbauarbeiten.

Für die Berechnung der aus Bautätigkeiten herrührenden Treibhausgasemissionen gibt es bis dato keinen universellen Ansatz. Es wird ein Vorschlag zur Ermittlung von Treibhausgasemissionen bei Spezialtiefbauarbeiten gemacht, angelehnt an die Normen ISO 14040 und ISO 14044. Der vorgestellte Berechnungsansatz ist auf jede Art von Spezialtiefbauarbeiten anwendbar und führt zu einer zuverlässig genauen Abschätzung der Treibhausgasemissionen von Spezialtiefbauarbeiten. Die abschließende Gegenüberstellung der Treibhausgasemissionen zweier Gründungsvarianten (Bohrpfähle und Rüttelstopfverdichtung) eines Bauvorhabens zeigt, dass das verwendete Baumaterial einen großen Einfluss auf die Treibhausgasbilanz hat. Gegenüber einer Bohrpfahllösung kann durch den Einsatz der Rüttelstopfverdichtung eine massive Reduzierung der Treibhausgasemissionen erreicht werden.
WHEN DO FAT TAXES INCREASE CONSUMER WELFARE?
Authors: Lusk Jayson L. , Schroeter Christiane
Published: September 2011

Previous analyses of fat taxes have generally worked within an empirical framework in which it is difficult to determine whether consumers benefit from the policy. This note outlines on simple means to determine whether consumers benefit from a fat tax by comparing the ratio of expenditures on the taxed good to the weight effect of the tax against the individual's willingness to pay for a one‐pound weight reduction. Our empirical calculations suggest that an individual would have to be willing to pay about $1500 to reduce weight by one pound for a tax on sugary beverages to be welfare enhancing. The results suggest either that a soda tax is very unlikely to increase individual consumer welfare or that the policy must be justified on some other grounds that abandon standard rationality assumptions. Copyright © 2011 John Wiley & Sons, Ltd.
Quantifying fine‐grained sediment sources in the River Axe catchment, southwest England: application of a Monte Carlo numerical modelling framework incorporating local and genetic algorithm optimisation
Authors: Collins A.L. , Zhang Y. , Walling D.E. , Grenfell S.E. , Smith P. , Grischeff J. , Locke A. , Sweetapple A. , Brogden D.
Published: September 2011

Increasing recognition of the deleterious environmental effects of excessive fine sediment delivery to watercourses means that reliable sediment source assessment represents a fundamental component of catchment planning targeting the protection of freshwater resources and their ecological integrity. Sediment tracing or fingerprinting approaches have been increasingly used to provide catchment scale sediment source information, but there is a need to continue refining existing procedures especially with respect to uncertainty analysis during mass balance modelling. Consequently, an updated Monte Carlo numerical modelling framework was devised and tested, incorporating both conventional and robust statistics coupled with random and Latin Hypercube Sampling (LHS) together with local and genetic algorithm (GA) optimisation. A sediment sourcing study undertaken in the River Axe catchment, southwest England, suggested that the use of robust statistics and LHS with GA optimisation generated the best performance with respect to predicting measured bed sediment geochemistry in six out of eight model applications. On this basis, the catchment‐wide average median sediment source contributions were predicted to be 38 ± 1% (pasture topsoils), 3 ± 1% (cultivated topsoils), 37 ± 1% (damaged road verges) and 22 ± 1% (channel banks/subsurface sources). Using modelling frameworks which provide users with flexibility to compare local and global optimisation during uncertainty analysis is recommended for future sediment tracing studies. Copyright © 2011 John Wiley & Sons, Ltd.
Application of copulas for derivation of drought severity–duration–frequency curves
Authors: Janga Reddy M. , Ganguli Poulomi
Published: September 2011

This study presents copula‐based multivariate probabilistic approach to model severity–duration–frequency (S‐D‐F) relationship of drought events in western Rajasthan, India. Drought occurrences are analysed using standardized precipitation index computed on monthly mean areal precipitation, aggregated at a time scale of 6 months. After testing with a series of probability density functions, the drought variable severity is found to be better represented with log‐normal distribution, whereas duration is well fitted with exponential distribution. Four different classes of bivariate copulas – Archimedean, extreme value, Plackett, and elliptical families are evaluated for modelling joint distribution of drought characteristics. It is observed that the extreme value copula – Gumbel–Hougaard copula – performed better as compared with other classes of copulas, based on results of various statistical tests and upper tail dependence coefficient. The joint distribution obtained from best performing copula is then employed to determine conditional return period and to derive drought severity‐duration‐frequency (S‐D‐F) curves for the study region. The results of the study suggests that the copula method can be used effectively to derive the drought S‐D‐F curves, which can be helpful in planning and adopting suitable drought mitigation strategies in drought‐prone areas. Copyright © 2011 John Wiley & Sons, Ltd.
A modified monthly degree‐day model for evaluating glacier runoff changes in China. Part II: application
Authors: Zhang Shiqiang , Gao Xin , Ye Baisheng , Zhang Xiaowen , Hagemann Stefan
Published: September 2011

The glacier mass balance, area change, and glacier runoff in the Yarkant River Basin (YRB) and the Beida River Basin (BRB) were estimated from 1961 to 2006 by employing a modified monthly degree‐day model. Comparisons between the simulated and observed mass balance, equilibrium line altitude, and glacier runoff suggest that the model can be used to analyze the long‐term changes of glacier mass balance and runoff in the YRB and the BRB. The glacier mass balances of the YRB and the BYB both have a significantly decreasing trend with −4.39 mm a‐1 and −8.15 mm a‐1 from 1961 to 2006 because of a significant increase in ablation caused by increasing summer air temperatures, especially since 1996. The total runoff in glacier areas has a significant increasing trend with 0.23 × 108 m3 a‐1 and 0.02 × 108 m3 a‐1 in the YRB and the BRB, respectively. By comparing the mean mass balance during the period 1961 to 1986 with that of the 1987 to 2006, the BRB glacier mass balance's sensitivity to temperature is at 0.33 m a‐1 °C, nearly twice as much as that of the YRB at 0.16 m a‐1 °C. The difference between the glacier temperature sensitivity in the YRB and the BRB is primarily because the glacier elevation band area weighted altitude of the YRB is about 700 m higher than that of BRB. The glacier elevation band area weighted summer air temperature in the YRB is around 2 °C lower than that of the BRB. Therefore, the annual positive degree‐day of the YRB and the BRB increases by about 21.0 °C and 77.3 °C respectively when the summer air temperature increases by 1 °C, resulting into more glacier ablation and runoff in the BRB than in the YRB. Copyright © 2011 John Wiley & Sons, Ltd.
Preclinical risk assessment of drug‐induced hypo‐ and hyperprolactinemia
Authors: Hargreaves Adam , Harleman Johannes
Published: September 2011

Drug‐induced changes in prolactin signaling may obscure interpretation of preclinical toxicological endpoints. However, with informed consideration, classic hallmarks of hypo‐/hyperprolactinemia can be recognized in short‐ and long‐term rodent bioassays. Findings can be supported and expanded with additional in vivo and in vitro datasets. When taken together with human epidemiological evidence pertaining to the consequences of drug‐induced hypo‐/hyperprolactinemia, such findings permit both an analysis of human relevance and an assessment of human risk. Copyright © 2011 John Wiley & Sons, Ltd.
Ultrastructural aspects of Callithrix penicillata lingual papillae
Authors: Branco Erika , Pereira Washington Luiz Assunção , De Lima Ana Rita , Franciolli André Luiz Rezende , Rici Rose Eli Grassi , Miglino Maria Angelica , Muniz José Augusto Pereira Carneiro , Imbeloni Aline
Published: September 2011

Callithrix penicillata belongs to the family Callitrichidae, Callithrix genus. They are basically insectivorous, but they consume fruits. The mucosa of the tongue is composed of some papillary types, revealing different levels of expertise. The present study attempted to describe the morphological and ultrastructural aspects of the dorsal surface of the C. penicillata, describing the characteristics and distribution of papillae found. Five tongues of C. penicillata (two females and three males), obtained from breeding colonies of CENP‐Ananindeua‐PA, died from natural causes. The material was fixed partly in a buffer solution paraformaldehyde 10% and partly in modified Karnovsky solution, divided into apex, body, and root, and then the fragments were used in light microscopy and scanning electron microscopy. The average length of the tongue of the females was 22 mm and for males 20.5 mm. Three types of papillae were described: filiform (along all tissue extension with 154 μm of diameter), fungiform (along all tissue extension with 275 μm of diameter), and vallate (just three units in caudal (dorsal) portion with 672 μm of diameter). Data analysis indicates that the distribution and ultrastructural morphology of the C. penicillata lingual papillae are some similar to other primates. Microsc. Res. Tech. 2011. © 2011 Wiley Periodicals, Inc.
A new algorithm to reduce noise in microscopy images implemented with a simple program in python
Authors: Papini Alessio
Published: September 2011

All microscopical images contain noise, increasing when (e.g., transmission electron microscope or light microscope) approaching the resolution limit. Many methods are available to reduce noise. One of the most commonly used is image averaging. We propose here to use the mode of pixel values. Simple Python programs process a given number of images, recorded consecutively from the same subject. The programs calculate the mode of the pixel values in a given position (a, b). The result is a new image containing in (a, b) the mode of the values. Therefore, the final pixel value corresponds to that read in at least two of the pixels in position (a, b). The application of the program on a set of images obtained by applying salt and pepper noise and GIMP hurl noise with 10–90% standard deviation showed that the mode performs better than averaging with three‐eight images. The data suggest that the mode would be more efficient (in the sense of a lower number of recorded images to process to reduce noise below a given limit) for lower number of total noisy pixels and high standard deviation (as impulse noise and salt and pepper noise), while averaging would be more efficient when the number of varying pixels is high, and the standard deviation is low, as in many cases of Gaussian noise affected images. The two methods may be used serially. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Lentiviral‐based BMP4 in vivo gene transfer strategy increases pull‐out tensile strength without an improvement in the osteointegration of the tendon graft in a rat model of biceps tenodesis
Authors: Coen Michael J. , Chen Shin‐Tai , Rundle Charles H. , Wergedal Jon E. , Lau Kin‐Hing William
Published: September 2011

Background

The present study aimed to develop a rat model of biceps tenodesis and to assess the feasibility of a lentiviral (LV)‐based bone morphogenetic protein (BMP) 4 in vivo gene transfer strategy for healing of biceps tenodesis.

Methods

A rat model of biceps tenodesis was developed with an interference‐fit open surgical technique. A LV vector expressing a BMP4 gene or β‐galactosidase (β‐gal) control gene was applied to the bone tunnel and the tendon graft before its insertion into the bone tunnel. Osteointegration was assessed by histology and pull‐out tensile strength was measured by a biomechanical test suitable for small rat biceps tendon grafts.

Results

Neo‐chondrogenesis was seen at the tendon–bone interface of LV‐BMP4‐treated but not control rats. The LV‐BMP4‐treated rats showed 32% (p < 0.05) more newly‐formed trabecular bone at the tendon–bone junction than the LV‐β‐gal‐treated controls after 3 weeks. However, the sites of neo‐chondrogenesis and new bone formation in the LV‐BMP4‐treated tenodesis were highly spotty. Although the LV‐BMP4 strategy did not promote bony integration of the tendon graft, it yielded a 29.5 ± 11.8% (p = 0.066) increase in improvement the pull‐out strength of rat biceps tendons compared to the LV‐β‐gal treatment after 5 weeks.

Conclusions

Although the LV‐BMP4 in vivo gene transfer strategy did not enhance osteointegration of the tendon graft, it yielded a marked improvement in the return of the pull‐out strength of the tendon graft. This presumably was largely a result of the bone formation effect of BMP4 that traps or anchors the tendon graft onto the bony tunnel. Published 2011. This article is a US Government work and is in the public domain in the USA.