bluuebunny/crossref_metadata_2025 huggingface dataset:
Handedness control of peptide helices by amino acid side‐chain chirality: Ile/aIle peptides
Authors: Andreetto Erika , Peggion Cristina , Crisma Marco , Toniolo Claudio
Published: May 2006

A set of four hexapeptide sequences, each characterized by four strongly helicogenic Aib residues and all combinations of two isomeric Ile/aIle residues at positions 2 and 5, was synthesized by solution methods and fully characterized. A detailed solution (by FT–IR absorption, NMR, and CD techniques) and solid/crystalline state (by X‐ray diffraction) conformational investigation allowed us to validate our assumption that all four peptides are folded in well‐developed 310‐helical structures. However, the most relevant conformational conclusion extracted from the present 3D‐analysis is that the handedness of the 310‐helical structures formed does not seem to be sensitive to the configurational change at the β‐carbon atom of the constituent Ile versus the diastereomeric aIle residues (in other words, the dominant control on this important structural parameter appears to be exerted by the chirality of the amino acid α‐carbon atom). These results complement published findings on the diverging relative stabilities of the intermolecularly H‐bonded β‐sheet structures generated by Ile versus aIle homo‐oligopeptides. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 490–501, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Combined preoperative endoscopic and laparoscopic ultrasonography for prediction of R0 resection in upper gastrointestinal tract cancer
Authors: Mortensen M B , Fristrup C W , Ainsworth A P , Pless T , Nielsen H O , Hovendal C
Published: May 2006

Background

This study evaluated the ability of combined endoscopic and laparoscopic ultrasonography to predict R0 resection and avoid unnecessary surgery in patients with upper gastrointestinal tract cancer (UGIC).

Methods

A total of 411 consecutive patients with UGIC (182 pancreatic cancers, 134 gastric cancers and 95 oesophageal cancers) treated between January 2002 and May 2004 were analysed prospectively. The allocation of patients into resectability groups by endoscopic ultrasonography (EUS) and laparoscopic ultrasonography (LUS) was compared with the treatment actually undertaken.

Results

The combination of EUS and LUS correctly predicted R0 resection in 90·6 per cent, R1–R2 in 91 per cent and irresectability in 91·4 per cent of patients. Ten patients (2·4 per cent) had explorative laparotomy only. There were no complications associated with the EUS and LUS procedures.

Conclusion

The routine use of EUS and LUS before surgery predicted R0 resection in nine of ten patients and reduced the number of unnecessary laparotomies to less than 3 per cent.
Structure—Property‐Relation of Cu5Pb6O3Cl11, a Good Solid State Ionic Conductor for Cu+‐Ions.
Authors: Langecker Carsten , Andoura Karina , Keller Hans‐Lothar , Oldag Thorsten
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Effect of Additives on the Proline‐Catalyzed Ketone—Aldehyde Aldol Reactions.
Authors: Pihko Petri M. , Laurikainen Katri M. , Usano Annina , Nyberg Annika I. , Kaavi Jatta A.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Fesulphos‐Palladium(II) Complexes as Well‐Defined Catalysts for Enantioselective Ring Opening of meso Heterobicyclic Alkenes with Organozinc Reagents.
Authors: Cabrera Silvia , Gomez Arrayas Ramon , Alonso Ines , Carretero Juan C.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Synthesis of Heteroarylazulene
Authors: Shoji Taku , Kikuchi Shigeru , Ito Shunji , Morita Noboru
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Substituent Effects in Tandem Ring‐Closing Metathesis Reactions of Dienynes.
Authors: Boyer Francois‐Didier , Hanna Issam
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Zinc‐Mediated Chain Extension Reaction of 1,3‐Diketones to 1,4‐Diketones and Diastereoselective Synthesis of trans‐1,2‐Disubstituted Cyclopropanols.
Authors: Xue Song , Li Le‐Zhen , Liu Yong‐Kang , Guo Qing‐Xiang
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New Approach to Four‐ and Five‐Component Ugi Condensations Starting from Nitriles.
Authors: Simoneau Christopher A. , George Elizabeth A. , Ganem Bruce
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of C6F5‐Substituted Amines Containing Quaternary Carbon Atoms.
Authors: Dilman Alexander D. , Levin Vitalij V. , Belyakov Pavel A. , Struchkova Marina I. , Tartakovsky Vladimir A.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Direct Organocatalytic Enantioselective α‐Aminomethylation of Ketones.
Authors: Ibrahem Ismail , Zou Weibiao , Casas Jesus , Sunden Henrik , Cordova Armando
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Inclusion Properties of 6,6′‐Bi(benzo[b]fluoren‐5‐ol) Derivative by Cycloaromatization.
Authors: Kawano Tomikazu , Suehiro Masako , Ueda Ikuo
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Silylated Vinyloxiranes — Recent Advances and Synthetic Applications.
Authors: Marion Frederic , Calvet Sandrine , Marie Jean‐Charles , Courillon Christine , Malacria Max
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stereoselective Functionalization of Alkenyl‐β‐lactams.
Authors: Troisi Luigino , Pindinelli Emanuela , De Vitis Luisella , Granito Catia , Ronzini Ludovico
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Direct Access to Heteropolycyclic Spiroketones. 1,3‐Dichloroacetone as a Cyclopropanone Equivalent.
Authors: Paquette Leo A. , Hilmey David G. , Selvaraj Peter R.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of 4H‐3,1‐Benzoxazines by the Reaction of o‐(N‐Acylamino)benzyl Alcohols with DAST.
Authors: Nishio Takehiko , Kurokawa Yukiko , Narasaki Yoshiya , Tokunaga Tatsuhiro
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of (.+‐.)‐Brazilin Using IBX.
Authors: Huang Yaodong , Zhang Jinsong , Pettus Thomas R. R.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Asymmetric Hydrogenation of Unfunctionalized, Purely Alkyl‐Substituted Olefins
Authors: Bell Sharon , Wuestenberg Bettina , Kaiser Stefan , Menges Frederik , Netscher Thomas , Pfaltz Andreas
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stereoselective Synthesis of 1,3‐Diols
Authors: Bode Silke E. , Wolberg Michael , Mueller Michael
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mechanistic Comparison of High‐Fidelity and Error‐Prone DNA Polymerases and Ligases Involved in DNA Repair
Authors: Showalter Alexander K. , Lamarche Brandon J. , Bakhtina Marina , Su Mei‐I , Tang Kuo‐Hsiang , Tsai Ming‐Daw
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Katalytische Oxidation vs. mikrobiologischer Abbau von Grundwasserkontaminanten unter In‐situ‐Bedingungen
Authors: Köhler R. , Georgi A. , Lauenroth S. , Kopinke F.‐D.
Published: May 2006

Der katalytische oxidative Abbau organischer Schadstoffe in kontaminierten Grund‐ und Oberflächenwässern ist in den meisten Fällen durch die Anwesenheit einer autochthonen Mikroorganismenflora gekennzeichnet. Bisher ist oft noch ungeklärt, welche positiven oder negativen Beeinflussungen zwischen abiotischen und biotischen Vorgängen bei derartigen Prozessen auftreten. In dieser Arbeit wird ein für die Oxidation von Monochlorbenzol mit H2O2 entwickelter Oxidationskatalysator mit Eisen als Aktivkomponente auf einem makroporösen keramischen Träger unter realen Bedingungen in einem Grundwasserstrom getestet. Dabei konnten über lange Zeiträume stabile Umsatzraten erzielt werden. Es zeigt sich, dass die Kombination aus chemisch‐katalytischer Oxidation und aerob‐mikrobiologischer Behandlung zur Entfernung bestimmter, mikrobiologisch schwer abbaubarer Substanzen vorteilhaft sein kann.
Energietransformation mit Hilfe des Wirbelrohres
Authors: Hebecker D. , Bittrich P.
Published: May 2006

Der Wirbelrohrprozess ist aus der Sicht der Energietransformation, ohne die keine Kälte erzeugt werden kann, als ein offener Kreisprozess einzuordnen, im dem Niedertemperaturwärme durch Zuführung von Arbeit auf ein höheres Temperaturniveau gehoben wird, also ein Synproportionierungsprozess. Da die Energieübertragung ausschließlich über Schubspannung erfolgt, ist die Effektivität des Kreisprozesses extrem gering. Dies wird durch den Vergleich mit reversiblen Prozessmodellen und der exergetischen Bewertung der Teilprozesse verdeutlicht. Die geringe thermodynamische Effektivität des Wirbelrohrs schränkt seine Einsatzgebiete auf wenige Sonderfälle ein, bei denen kurzzeitig und in geringem Umfang Kälte benötigt wird bzw. bei denen Druckgas zur Verfügung steht und keine sinnvollere Nutzung möglich ist. Ein hoffnungsvolles Einsatzgebiet ergibt sich für das Wirbelrohr jedoch bei der Staubabscheidung.
Einsatzmöglichkeiten von Thiolen und Polytetraflurethylen als Antihaftschichten für Mikrowärmeübertrager
Authors: Rinke G. , Kerschbaum S. , Nold E. , Quinten A.
Published: May 2006

Um Fouling bei Mikrowärmeübertragern mit Kapillaren von 0,2 mm × 0,1 mm Querschnitt zu verhindern, werden verschiedene Antihaftschichten auf ihre Eignung untersucht. Dazu werden zum einen Thiole verwendet, die eine Monolage mit fester kovalenter Bindung zum Substrat bilden. Zum anderen wird Polytetraflurethylen aus einer Lösung im Tauchverfahren abgeschieden. Damit konnte der Kontaktwinkel am Beispiel von Wasser und Biodiesel deutlich verbessert werden.
π‐Prismands – Flexible Hosts for Metal Ions
Authors: Kunze Andreas , Balalaie Saeed , Gleiter Rolf , Rominger Frank
Published: May 2006

The π‐prismands dealt with in this paper are: 1,8‐diazabicyclo[6.6.6]eicosa‐4,11,17‐triyne (6), 1,8‐diazabicyclo[6.6.5]nonadeca‐4,11‐diyne (7), 1,8‐diazabicyclo[6.6.6]eicosa‐4,11‐diyne (8), 1,10‐diazabicyclo[8.6.6]docosa‐5,13,19‐triyne (9), 17‐(1,4)benzena‐1,8‐diazabicyclo[6.6.5]nonadecaphane‐4,11‐diyne (10), 11,16‐(1,4)dibenzena‐1,8‐diazabicyclo[6.5.5]octadecaphane‐4‐yne (11) and 4,10,15‐(1,4)tribenzena‐1,7‐diazabicyclo[5.5.5]heptadecaphane (12). The synthesis of 9 is reported. The molecular parameters obtained from X‐ray investigations on single crystals of 6–9 as well as of 10–12 are compared with each other. Also discussed are the structures of the monoprotonated forms of 6 and 12. The π‐prismands 6–12 form stable complexes with Ag+ and Cu+. The crystal structures of the metal complexes as well as their spectroscopic properties are reported. Both reveal that the metal center interacts with the nitrogen atoms and the π‐systems of the bridges.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Linkage analysis with gene‐environment interaction: model illustration and performance of ordered subset analysis
Authors: Schmidt Silke , Schmidt Michael A. , Qin Xuejun , Martin Eden R. , Hauser Elizabeth R.
Published: May 2006

The ordered subset analysis (OSA) method allows for the incorporation of covariates into the linkage analysis of a dichotomous disease phenotype in order to reduce genetic heterogeneity. Complex human diseases may involve gene‐environment (G × E) interactions, which represent a special form of heterogeneity. Here, we present results of a simulation study to evaluate the performance of OSA when the disease‐generating mechanism includes G × E interaction, in the absence of main effects of gene and environment. First, the complex simulation models are illustrated graphically. Second, we show that OSA is underpowered to detect small to moderate interaction effects, consistent with previous evaluations of other linkage analysis methods. When interaction effects are large enough to produce substantial marginal effects, standard linkage methods have sufficient power to detect significant baseline linkage evidence in the entire dataset. The power of OSA to improve upon a high baseline lod score is then strongly dependent on the underlying genetic model, especially the susceptibility allele frequency. If significant, OSA identifies family subsets that are more efficient for follow‐up analysis than the entire dataset, in terms of the proportion of susceptible genotypes among generated marker genotypes. For example, when strong G × E interaction with RR(G × E)=10 is operating in at least 70% of families in the dataset, OSA has at least 70% power to detect a subset of families with significantly greater linkage evidence, the majority of linked families are captured in the OSA subset, and the per‐genotype efficiency in the subset is 20–30% greater than in the entire dataset. Genet. Epidemiol. 2006. © 2006 Wiley‐Liss, Inc.
The economics of diagnosis
Authors: Laking George , Lord Joanne , Fischer Alastair
Published: May 2006

Any population can be divided into two groups, one with the presence of a given disease or condition, and the other without. Diagnosis consists of using tests to sort the population into these groups. Diagnostic tests use a threshold value of a diagnostic variable to distinguish between disease‐positive and disease‐negative individuals. The analysis of error in diagnostic tests has typically been undertaken using receiver‐operator characteristic (ROC) curves. More recently, economic value of information (VOI) methods have characterised the costs and consequences of testing. This paper develops a new method for economic test evaluation, which we call ROTS analysis. The ROTS curve plots the costs and effects of changing test thresholds, in cost‐effectiveness space.

We illustrate the use of our method with a worked example, and show how it can answer three key questions: (1) Is there any test that is worth doing? (2) What is a test's optimum operating point in terms of sensitivity and specificity? (3) If two tests are available, which is best? We contrast the merits of our method with those of established ROC and VOI analysis. We argue that ROTS analysis more clearly reveals the link between changing test thresholds and the cost‐effectiveness of different treatments. Copyright © 2006 John Wiley & Sons, Ltd.
Cancer survival is dependent on season of diagnosis and sunlight exposure
Authors: Lim Hyun‐Sook , Roychoudhuri Rahul , Peto Julian , Schwartz Gary , Baade Peter , Møller Henrik
Published: May 2006

Sunlight is essential for the production of vitamin D in the body. Evidence exists to suggest that vitamin D metabolites may have a role in tumor growth suppression. In this large study, involving over a million cancer patients from the United Kingdom, we have analyzed the role of season of diagnosis and sunlight exposure in cancer survival for cancers of the breast, colorectum, lung, prostate and at all sites combined. We used population‐based data from the Thames Cancer Registry to analyze cancer survival in periods 0–1 and 0–5 years after diagnosis. The analysis was performed using Cox proportional regression analysis adjusting for age and period at diagnosis and including season of diagnosis and sunlight exposure in the preceding months as factors in the analysis. We found evidence of substantial seasonality in cancer survival, with diagnosis in summer and autumn associated with improved survival compared with that in winter, especially in female breast cancer patients and both male and female lung cancer patients (hazard ratios 0.86 [95% CI 0.83–0.89], 0.95 [95% CI 0.92–0.97] and 0.95 [95% CI 0.93–0.98] respectively). Cumulative sunlight exposure in the months preceding diagnosis was also a predictor of subsequent survival, although season of diagnosis was a stronger predictor than cumulative sunlight exposure. We found seasonality in cancer survival to be stronger in women than in men. Our results add to a growing body of evidence that vitamin D metabolites play an important role in cancer survival. © 2006 Wiley‐Liss, Inc.
Investigation of biofilm growth and attrition in a three‐phase airlift bioreactor using 35SO42− as a radiolabelled tracer
Authors: Gikas Petros , Livingston Andrew G
Published: May 2006

The growth and biomass loss pattern for immobilized cells growing on diatomaceous earth particles in a three‐phase airlift bioreactor (TPALB) is studied using 35S as a radiolabelled tracer. A monoculture of Beneckea natriegens was grown immobilized on support particles in a 3 L TPALB. Sterile conditions were maintained during the experiments, and n‐propanol was used as the sole carbon source. After the system reached steady state, the unlabelled sulfate (SO42−) in the feed tank was substituted by a radioactive grade (35SO42−), and the assimilation of 35S in the immobilized and in the suspended cells was monitored. The results indicated that the growth rate of immobilized biomass was not uniform throughout the biofilm. More specifically, it was concluded that cells growing closer to the external biofilm layer exhibit a higher growth rate, and that biomass loss from the biofilm was through attrition at the outer biofilm surface rather than by sloughing off of whole sections of biofilm. Copyright © 2006 Society of Chemical Industry
Myotonic dystrophy protein kinase monoclonal antibody generation from a coiled‐coil template
Authors: Helmke Steve M. , Lu Stephen M. , Harmon Michelle , Glasford Joe W. , Larsen Tricia D. , Kwok Stanley C. , Hodges Robert S. , Perryman M. Benjamin
Published: May 2006

Myotonic dystrophy protein kinase (DMPK) was the initial representative of a ubiquitous protein kinase family that regulates cell size and shape. DMPK is highly expressed in heart and skeletal muscle and transgenic over‐expression induces cardiac hypertrophy. The characterization of DMPK has been limited by the paucity of immunological reagents with high affinity and well‐defined specificity. Amino acid sequence data was used to predict the surface exposure of the coil‐coiled domain of DMPK. These exposed amino acids were substituted into an extremely stable coiled‐coil template to produce a peptide antigen. Sera from mice immunized with the peptide conjugated to keyhole limpet hemocyanin were screened against recombinant DMPK using Western blots. Murine spleens expressing DMPK antibodies were used to produce hybridoma cell lines. Hybridoma supernatants were further screened against recombinant DMPK and four clonal hybridoma cell lines expressing DMPK antibodies were generated. These four monoclonal antibodies recognized recombinant DMPK in Western blots of COS‐1 cell lysates expressing high levels of recombinant DMPK and immunoprecipitated recombinant DMPK from COS‐1 cell lysates. The identity of the immunoprecipitated DMPK was confirmed by MALDI‐TOF mass spectrometry and peptide mass fingerprinting. DMPK was the only protein detected in the immunoprecipitates, indicating the high specificity of the antibodies. Western blots immunostained with two of the monoclonal antibodies specifically recognized the two isoforms of endogenous DMPK, DMPK‐1 and DMPK‐2, that are expressed at low levels in the human heart. The recognition of low amounts of DMPK‐1 and DMPK‐2 indicates the high affinity of these antibodies. A human heart lysate was subjected to ammonium sulfate precipitation and column chromatography to produce a fraction that was enriched in DMPK. One of the monoclonal antibodies immunoprecipitated endogenous DMPK from this fraction. This antibody was used for immuno‐localization studies of an adenoviral DMPK construct, expressed in adult mouse cardiac myocytes. This construct was localized to the intercalated disc, the site of endogenous DMPK, indicating that this antibody is applicable to immuno‐localization studies. This study demonstrates the utility of the described procedure for generation of specific monoclonal antibodies with high affinity for epitopes in coiled‐coiled domains of mammalian proteins expressed at low levels. Copyright © 2006 John Wiley & Sons, Ltd.
Large‐scale production and characterisation of wheat bran arabinoxylooligosaccharides
Authors: Swennen Katrien , Courtin Christophe M , Lindemans Geert CJE , Delcour Jan A
Published: May 2006

Arabinoxylooligosaccharides (AXOS) were enzymically produced on a large scale from commercial wheat bran. This implied enzyme‐based removal of starch and proteins to yield an arabinoxylan (AX) enriched destarched, deproteinised wheat bran fraction, and further incubation of the latter with a Bacillus subtilis endoxylanase converting AX into AXOS. The recovered wheat bran AXOS had a purity of 72% and an average degree of polymerisation and degree of substitution of 15 and 0.27, respectively. Fractional precipitation with ethanol was effective in separating the wheat bran AXOS into fractions with different structure. At a given ethanol concentration, the degree of substitution, degree of polymerisation and substitution pattern of wheat bran AXOS all influenced their precipitation behaviour. Copyright © 2006 Society of Chemical Industry
Quality of cocoa beans dried using a direct solar dryer at different loadings
Authors: Hii Ching L , Abdul Rahman R , Jinap S , Che Man YB
Published: May 2006

In this study fermented cocoa beans were dried in a direct solar dryer at three levels of loading (20, 30 and 60 kg). Surface mouldiness was found to be heavy in the 60 kg treatment, with beans appearing blackish. All the dried beans were reasonably acceptable in terms of vinegary odour and weak in alcohol odour. Weak odour was also detected for the faecal, rancid and cheesy odours. The 60 kg treatment was rated strong for wet sock odour due to poor drying condition. A significant difference (P < 0.05) was found between the 60 kg treatment and the lower loading treatments for pH and titratable acidity. A cut test showed that the lower loading treatments resulted in a higher percentage of brown beans. The 20 kg treatment showed the highest cut test score, which is significantly different (P < 0.05) from the 60 kg treatment. Fermentation index also showed a tendency for lower loading treatments to have a higher index. No significant difference (P > 0.05) was found among the treatments in terms of cocoa, astringency, bitterness and sourness flavour notes. However, better flavour was observed for beans from the 20 kg treatment. No mouldy off flavour was found in any of the dried beans. Overall quality assessment showed that the 20 kg treatment was able to produce reasonably good‐quality beans as compared to other loadings and therefore is recommended for the direct solar dryer. Copyright © 2006 Society of Chemical Industry
How project approach influences adoption of SWC by farmers, examples from southern Mali
Authors: Bodnár F. , Schrader T. , Van Campen W.
Published: May 2006

Choices in project approach affect the continuation of soil and water conservation (SWC) after project withdrawal, and thus the sustainability and cost effectiveness of the project. A SWC project was carried out in southern Mali between 1986 and 1998. Its features were the promotion of cheap and simple SWC measures, a participatory village extension approach with limited use of incentives, and the incorporation of the SWC programme in an existing Malian extension service. By 2000, farmers in half the 5000 villages in southern Mali had been trained in SWC. By 2002, erosion‐control measures had been installed in 94 per cent of the villages in southern Mali by 46 per cent of the farmers and in 15 per cent of the fields. Though external donor support has stopped, farmer adoption is steadily continuing and spreading to untargeted villages. Copyright © 2006 John Wiley & Sons, Ltd.
Monitoring of the Synthesis of Hyperbranched Poly(urea‐urethane)s by Real‐Time Attenuated Total Reflection (ATR)‐FT‐IR Spectroscopy
Authors: Sahre Karin , Abd Elrehim Mona Hasan , Eichhorn Klaus‐Jochen , Voit Brigitte
Published: May 2006

Summary: The reaction of 2,4‐TDI and DEA, as an A2 + B*B2 polymerization system towards hyperbranched HPUs was followed using in situ ATR‐FT‐IR spectroscopy. The decrease in intensity of the NCO absorption band of the reactive isocyanate group of 2,4‐TDI along with the formation and growth of the new characteristic bands of urethane and urea groups were detected. The reactivity difference of both NH and OH groups towards the NCO group at low temperatures was proven. The rate of the reaction was found to be affected by changing the temperature, the rate of addition of the B*B2 monomer and the type of solvent. Moreover, the increase of the carbonyl vibration and the amide II bands of urea was very obvious during the addition of the stopper DEA. Thus, it was possible to verify the individual reaction steps of this complex polyreaction and to correlate these with the structural development of the resulting macromolecules.

Characteristic vibration bands of urethane and urea groups in the IR spectra (1 780–1 480 cm−1) during the polymerization reaction.

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Characteristic vibration bands of urethane and urea groups in the IR spectra (1 780–1 480 cm−1) during the polymerization reaction.
Morphology and Structure of Constituent Fibres in Thermally Bonded Nonwovens
Authors: Wang Xiao Yan , Gong Rong Hua
Published: May 2006

Summary: A new process has been developed to produce three‐dimensional nonwovens directly from staple fibres. In order to establish suitable windows of the process parameters to achieve high‐quality nonwoven products, the effects of thermal bonding temperature, dwell time and mould material on the morphology and structure of the fibre have been investigated using PP/PET bi‐component fibres. It was evident from both scanning electron microscope images and Raman spectra that thermal‐induced shrinkage of the PP sheath fibre occurred in the thermal bonding process, leading to deformation and cracking of the PP sheath and exposure of the PET core. X‐ray diffraction results revealed crystal imperfection and/or less ordered polymer chains, more γ‐form and thermal contraction of the crystal lattice for the PP sheath fibre, while birefringence measurements indicated that both the birefringence and the orientation factor for the PP fibre decreased after the thermal bonding process. The degrees of the thermal‐induced shrinkage increased, and the crystallinity, birefringence and orientation factor of the PP sheath fibre decreased with increasing thermal bonding temperature, dwell time and thermal conductivity of the mould material. All these can be attributed to the different levels of modification of chemical composition caused by thermal oxidative degradation and thermal‐induced relaxation of the orientation during the thermal bonding process.

Changes of morphology and crystalline features of PP/PET fibre after thermal bonding process.

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Changes of morphology and crystalline features of PP/PET fibre after thermal bonding process.
Nano/Micro Particle Hybrid Composites for Scratch and Abrasion Resistant Polyacrylate Coatings
Authors: Bauer Frank , Flyunt Roman , Czihal Konstanze , Buchmeiser Michael R. , Langguth Helmut , Mehnert Reiner
Published: May 2006

Summary: UV curable acrylate formulations with a high content of fumed, nano‐sized silica were prepared to improve their application for abrasion and scratch resistant top coats. Grafting of trialkoxysilanes onto the surface of nanoparticles facilitated their embedding in the formulation and alleviated the effect of undesired increase in viscosity and dilatancy. Modified nanoparticles were obtained from several organosilanes and characterized by a multitechnique approach. To avoid problems during redispersion, in situ modification of nano‐sized silica was performed using the liquid acrylate formulation as a diluting and deagglomerating agent. These nanocomposite materials exhibit markedly improved properties as compared to neat acrylate coatings, e.g. heat, scratch, and abrasion resistance. However, a much better abrasion resistance was obtained for coatings containing both silica nanoparticles and corundum microparticles. By using various grades of corundum, a synergetic effect of nano/micro hybrid composite materials has been studied for parquet and flooring applications.

Pictures of neat polyacrylate coating (on the left) and nano/micro hybrid composite material (18 wt.‐% silica +15 wt.‐% corundum) on parquet substrate after Taber Abraser Test.

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Pictures of neat polyacrylate coating (on the left) and nano/micro hybrid composite material (18 wt.‐% silica +15 wt.‐% corundum) on parquet substrate after Taber Abraser Test.
Augmented cancer resistance and DNA damage response phenotypes in PPM1D null mice
Authors: Nannenga Bonnie , Lu Xiongbin , Dumble Melissa , Van Maanen Marc , Nguyen Thuy‐Ai , Sutton Richard , Kumar T. Rajendra , Donehower Lawrence A.
Published: May 2006

The p53‐induced serine/threonine phosphatase, protein phosphatase 1D magnesium‐dependent, delta isoform (PPM1D) (or wild‐type p53‐induced phosphatase 1 (Wip1)), exhibits oncogenic activity in vitro and in vivo. It behaves as an oncogene in rodent fibroblast transformation assays and is amplified and overexpressed in several human tumor types. It may contribute to oncogenesis through functional inactivation of p53. Here, we show that the oncogenic function of PPM1D is associated with its phosphatase activity. While overexpressed PPM1D may be oncogenic,PPM1Dnull mice are resistant to spontaneous tumors over their entire lifespan. This cancer resistance may be based in part on an augmented stress response following DNA damage.PPM1Dnull mice treated with ionizing radiation display increased p53 protein levels and increased phosphorylation of p38 MAP kinase, p53, checkpoint kinase 1 (Chk1), and checkpoint kinase 2 (Chk2) in their tissues compared to their wild‐type (WT) counterparts. MalePPM1Dnull mice show a modest reduction in longevity, reduced serum insulin‐like growth factor 1 (IGF‐1) levels, and reduced body weight compared to WT mice. ThePPM1Dnull mouse phenotypes indicate that PPM1D has a homeostatic role in abrogating the DNA damage response and may regulate aspects of male longevity. © 2006 Wiley‐Liss, Inc.
Targeting carcinogenesis: A role for the prolyl isomerase Pin1?
Authors: Lu Kun Ping , Suizu Futoshi , Zhou Xiao Zhen , Finn Greg , Lam Prudence , Wulf Gerburg
Published: May 2006

Phosphorylation of proteins on serine or threonine residues that immediately precede proline (pSer/Thr‐Pro) is a central signaling mechanism in cell proliferation and transformation. Recent studies indicate that certain pSer/Thr‐Pro motifs in native proteins exist in two completely distinct conformations, cis and trans, whose conversion is markedly slowed down upon phosphorylation, but specifically catalyzed by the peptidyl‐prolyl cis/trans isomerase Pin1. Importantly, such Pin1‐catalyzed conformational changes can have profound effects on the function of many phosphorylation signaling pathways, thereby playing an important role in various cellular processes. Moreover, increasing evidence indicates that aberrant Pin1 function plays an important role in the pathogenesis of some human diseases. Notably, Pin1 is not only overexpressed in a large number of human cancers, but also is an excellent prognostic marker in some cancers. Furthermore, Pin1 overexpression can function as a critical catalyst that amplifies multiple oncogenic signaling pathways during oncogenesis. Moreover, Pin1 overexpression causes cell transformation, centrosome amplification, genomic instability, and tumor development. In contrast, Pin1 knockout in mice prevents certain oncogenes from inducing tumors and Pin1 inhibition in cancer cells suppresses their cell proliferation, transformed phenotype and tumorigenicity in nude mice as well as increases the response to other anticancer agents. These results suggest that Pin1‐mediated postphosphorylation regulation may provide a unique opportunity for disrupting oncogenic pathways, and thereby represent an appealing target for novel anticancer therapies. © 2006 Wiley‐Liss, Inc.
Roles of reactive oxygen species in hepatocarcinogenesis and drug resistance gene expression in liver cancers
Authors: Tien Kuo M. , Savaraj Niramol
Published: May 2006

Hepatocellular carcinoma (HCC) has traditionally been an attractive system for cancer research because many animal HCC models are available. It is well known that liver tumors in animals can be induced by many different protocols, such as chronic hepatitis viral infections, carcinogens, toxins, steroid hormones, and dietary intervention. Although these different inducers have different cellular targets and modes of cytotoxic effects, their common denominator is the formation of reactive oxygen species (ROS). In this review, we present compelling evidence to support the hypothesis that ROS play important roles in hepatocarcinogenesis and the associated upregulation of drug resistance gene expression. © 2006 Wiley‐Liss, Inc.
Cerebral plasticity in crossed C7 grafts of the brachial plexus: An fMRI study
Authors: Beaulieu Jean‐Yves , Blustajn Jerry , Teboul Frederic , Baud Patrice , De Schonen Scania , Thiebaud Jean‐Baptiste , Oberlin Christophe
Published: May 2006

In order to rescue elbow flexion after complete accidental avulsion of one brachial plexus, seven patients underwent a neurotization of the biceps with fibers from the contralateral C7 root. The C7 fibers used for the graft belonged to the pyramidal pathway, which descends from the cerebral hemisphere ipsilateral to the damaged plexus, and which controls extension and abduction of the contralateral arm. After several months of reeducation, a functional magentic resonance imaging study was performed with a 1.5 tesla clinical magnetic resonance scan system, in order to investigate the central neural networks involved in the recovery of elbow flexion. Functional brain images were acquired under four conditions: flexion of each of the two elbows, and imagined flexion of each elbow. Results show that flexion of the neurotized arm is associated with a bilateral network activity. The contralateral cortex originally involved in control of the rescued arm still participates in the elaboration and control of the task through the bilateral premotor and primary motor cortex. The location of the ipsilateral clusters in the primary motor, premotor, supplementary motor area, and posterior parietal areas is similar among patients. The location of contralateral activations within the same areas differs across patients. © 2006 Wiley‐Liss, Inc. Microsurgery, 2006.
Metabolism of Maillard reaction products by the human gut microbiota – implications for health
Authors: Tuohy Kieran M. , Hinton Davinia J. S. , Davies Sarah J. , Crabbe M. James C. , Gibson Glenn R. , Ames Jennifer M.
Published: May 2006

The human colonic microbiota imparts metabolic versatility on the colon, interacts at many levels in healthy intestinal and systemic metabolism, and plays protective roles in chronic disease and acute infection. Colonic bacterial metabolism is largely dependant on dietary residues from the upper gut. Carbohydrates, resistant to digestion, drive colonic bacterial fermentation and the resulting end products are considered beneficial. Many colonic species ferment proteins but the end products are not always beneficial and include toxic compounds, such as amines and phenols. Most components of a typical Western diet are heat processed. The Maillard reaction, involving food protein and sugar, is a complex network of reactions occurring during thermal processing. The resultant modified protein resists digestion in the small intestine but is available for colonic bacterial fermentation. Little is known about the fate of the modified protein but some Maillard reaction products (MRP) are biologically active by, e. g. altering bacterial population levels within the colon or, upon absorption, interacting with human disease mechanisms by induction of inflammatory responses. This review presents current understanding of the interactions between MRP and intestinal bacteria. Recent scientific advances offering the possibility of elucidating the consequences of microbe‐MRP interactions within the gut are discussed.
Controlled polymerizations as tools for the design of star‐like and dendrimer‐like polymers
Authors: Taton Daniel , Gnanou Yves , Matmour Rachid , Angot Stéphanie , Hou Sijian , Francis Raju , Lepoittevin Bénédicte , Moinard Delphine , Babin Jérôme
Published: May 2006

This paper highlights our recent efforts to engineer polymer chains in star‐like and dendrimer‐like architectures using atom‐transfer radical polymerization (ATRP) and anionic ring‐opening polymerization (AROP) of ethylene oxide as synthetic tools. The scope and limitations of ATRP are first discussed when this method of controlled radical polymerization is applied to multifunctional initiators for the synthesis of star polymers by the core‐first approach. The switch from ATRP to AROP of ethylene oxide and vice versa allows access to branched amphiphilic block copolymers exhibiting core–shell structures. Stress is also put on the methodologies for the selective branching of polymeric chain‐ends, with a view to introducing ω‐geminal functionalities from which further polymer branches can be grown. When linear polymer precursors are used, such a strategy leads to asymmetric and mikto‐arm stars but the same can be applied to multi‐arm stars so as to generate so‐called ‘dendrimer‐like (co)polymers’ that are dendrimers with true macromolecular generations. Copyright © 2006 Society of Chemical Industry
Study on hyperbranched polyesters as rheological modifier for Spandex spinning solution
Authors: Han Keqing , Li Wenjiang , Wu Chengxun , Yu Muhuo
Published: May 2006

The rheological behavior of polyurethane (PU)/N,N‐dimethylformamide (DMF) spinning solutions with various contents of hyperbranched polyesters was studied using a RS150L‐controlled stress rotational rheometer. The results showed that the viscosity of the spinning solutions could be greatly reduced by adding hyperbranched polyesters even at 0.5 wt% loading. The zero‐shear viscosity of solutions with hyperbranched polyesters was much lower than that of pure PU/DMF solution, which indicated a lower degree of entanglement when solutions were in a static state. The apparent activation energy of viscous flow and the critical shear rate for shear thinning of solutions with hyperbranched polyesters were much lower than that for pure PU/DMF solution, which indicated a weaker entanglement structure formed. In addition, the effect of hyperbranched polyesters on the mechanical properties of Spandex fiber was discussed. Copyright © 2006 Society of Chemical Industry
Styrene–substituted‐styrene copolymerization using diphenylzinc–metallocene–methylaluminoxane systems
Authors: Rabagliati Franco M , Rodríguez Francisco J , Alla Abdel , Muñoz‐Guerra Sebastián
Published: May 2006

Homopolymerization of disubstituted styrenes (2,4‐ and 2,5‐dimethylstyrene) and trisubstituted styrene (2,4,6‐trimethylstyrene) and their copolymerization with styrene were carried out using diphenylzinc–metallocene–methylaluminoxane initiator systems for metallocene (n‐BuCp)2TiCl2 and for half‐metallocene CpTiCl3. The studied comonomers were found to be less reactive than p‐tertbutylstyrene, p‐methylstyrene and styrene. The results indicate that, even though the methyl group has I+ inductive effect, di‐ and tri‐methylstyrenes are reluctant to undergo either homopolymerization or copolymerization. This behavior suggests that the reactivity is regulated not only by the inductive effect of the alkyl group but also by the steric impediment caused by the crowding of the substituents on the benzene ring. Copyright © 2006 Society of Chemical Industry
Preparation and characterization of ultrafine electrospun polyacrylonitrile fibers and their subsequent pyrolysis to carbon fibers
Authors: Sutasinpromprae Juthawan , Jitjaicham Sujinda , Nithitanakul Manit , Meechaisue Chidchanok , Supaphol Pitt
Published: May 2006

The present contribution reports the fabrication and characterization of ultrafine polyacrylonitrile (PAN) fibers by electrospinning and further development of the as‐spun PAN fibers into ultrafine carbon fibers. The effects of solution conditions (i.e., solution concentration, viscosity, conductivity, and surface tension) and process parameters (i.e., applied electrostatic field strength, emitting electrode polarity, nozzle diameter, and take‐up speed of a rotating‐drum collector) on morphological appearance and average diameter of the as‐spun PAN fibers were investigated by optical scanning (OS) and scanning electron microscopy (SEM). The concentration, and hence the viscosity, of the spinning solutions significantly affected the morphology and diameters of the as‐spun PAN fibers. The applied electrostatic field strength and nozzle diameter slightly affected the diameters of the as‐spun fibers, while the emitting electrode polarity did not show any influence over the morphology and size of the as‐spun fibers. Utilization of the rotating‐drum collector enhanced the alignment of the as‐spun fibers. Within the investigated concentration range, the average diameter of the fibers ranged between 80 and 725 nm. Finally, heat treatment of the as‐spun fibers with their average diameter of about 450 nm was carried out at 230 and 1000 °C, respectively. Various characterization techniques revealed successful conversion into carbon fibers with an average diameter of about 250 nm. Copyright © 2006 Society of Chemical Industry
Mutation of Phe102 to Ser in the carboxyl terminal helix of Escherichia coli thioredoxin affects the stability and processivity of T7 DNA polymerase
Authors: Chiu Joyce , Tillett Daniel , March Paul E.
Published: May 2006

Processivity of T7 DNA polymerase relies on the coupling of its cofactor Escherichia coli thioredoxin (Trx) to gene 5 protein (gp5) at 1:1 stoichiometry. We designed a coexpression system for gp5 and Trx that allows in vivo reconstitution of subunits into a functional enzyme. The properties of this enzyme were compared with the activity of commercial T7 DNA polymerase. Examination of purified enzymes by sodium dodecyl sulfate–polyacrylamide gel electrophoresis revealed that the thioredoxin subunit of the two enzymes did not comigrate. To our surprise, we identified a mutation (Phe102 to Ser) in the Trx component from the commercial T7 DNA polymerase (gp5/TrxS102) that was not in the enzyme from the coexpression system (wild type gp5/Trx). A comparison of polymerase activity of the T7 DNA polymerases shows that both enzymes possessed similar specific activity but they were different in their residual activity at 37°C. The half‐life of gp5/TrxS102 was 7 min at 37°C and 12 min for gp5/Trx. gp5/TrxS102 polymerase activity was reduced by fourfold with 3′–5′ exonuclease activity as the prominent activity detected after 10 min of heat inactivation at 37°C. Supplementation of reaction mixtures containing gp5/TrxS102 with exogenous nonmutant thioredoxin restored the enzyme activity levels. Pulse proteolysis was used to demonstrate that TrxS102 unfolded at lower urea concentrations than wild type thioredoxin. Thus, Ser substitution at position 102 affected the structural stability of thioredoxin resulting in a reduced binding affinity for gp5 and loss of processivity. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Transport properties of some rare‐earth mono and bilayer manganite films
Authors: Taran Subhrangsu , Karmakar S. , Chou H. , Chaudhuri B. K.
Published: May 2006

We report the transport properties of both single‐layer (SL) La0.67Sr0.33MnO3 (SL1), La0.67Ca0.33MnO3 (SL2) and La0.67Sr1.33MnO4 (SL3) each of thickness 135 nm and bilayers (BL) SL1/SL3 (BL1) and SL2/SL3 (BL2) each of thickness 270 nm. All the films are deposited on SrTiO3(001) substrates by the off‐axis RF sputtering process. Compared to SL films, a large enhancement of magnetoresistance (MR) at 1.2 T field is observed in the BL films. Except for the antiferromagnetic (AF) SL3 film, two ferromagnetic (FM) films SL1 and SL2 showed metallic transitions, respectively, at T MI = 248 and 365 K. For the BL films, T MI shifts largely towards a lower temperature than the corresponding T MI of the corresponding SL films due to the increase of disorder and strain effect at the junction of the films. Temperature‐dependent resistivity (ρ ) curves, above T MI, are best fitted by the adiabatic small‐polaron hopping model, i.e. ρ = ρ 0T exp (E a/k BT ) with activation energy E a (BL) > E a(SL). Within the temperature range T D/2 < T < T MI (T D being the Debye temperature), the resistivity curves are well fitted with the variable range hopping (VRH) with effective number of carriers at the Fermi level [N (E F)], being different for BL and SL films. In the SL films, spin ordering completes below a critical temperature (T *, say) and a changeover of the transport mechanism dominated by the electron–electron scattering regime (T < T *) to an electron–magnon‐dominated scattering regime (T > T *) is observed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)