bluuebunny/crossref_metadata_2025 huggingface dataset:
The Interactions Affecting Organic Reactivity and Selectivity in Ionic Liquids
Authors: Chiappe Cinzia , Pieraccini Daniela , Pomelli Christian Silvio
Published: August 2007

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 Solution Properties of Hydrophobically Modified Polysaccharides
Authors: Khutoryanskiy Vitaliy V.
Published: August 2007

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.
Botanochemistry: Whole Plants for Asymmetric Catalysis
Authors: Leroy Bernard
Published: August 2007

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 Study for an Allergic Inflammation Model Using Human Lungs and Its Pharmacological Application
Authors: Hama Hiroshi , Ono Nobufumi , Abe Masayoshi
Published: August 2007

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.
Metabolism of Non‐Steroidal Antiinflammatory Drugs by Peroxidase: Implication for Gastrointestinal Mucosal Lesions
Authors: Muraoka Sanae , Miura Toshiaki
Published: August 2007

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.
Tribology of Hard Disk Drives — Magnetic Data Storage Technology
Authors: Castillo Jose , Bhushan Bharat
Published: August 2007

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.
Electrodeposition of Metals for Micro‐ and Nanostructuring at Interfaces Between Solid, Liquid and Gaseous Conductors: Dendrites, Whiskers and Nanoparticles
Authors: Peppler Klaus , Poelleth Manuel , Meiss Sebastian , Rohnke Marcus , Janek Juergen
Published: August 2007

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.
Confinement Effects on Chemical Reactions — Toward an Integrated Rational Catalyst Design
Authors: Santiso Erik E. , Kostov Milen K. , George Aaron M. , Nardelli Marco Buongiorno , Gubbins Keith E.
Published: August 2007

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.
Tumor lymphangiogenesis correlates with lymph node metastasis and clinicopathologic parameters in oral squamous cell carcinoma
Authors: Miyahara Mayumi , Tanuma Jun‐ichi , Sugihara Kazumasa , Semba Ichiro
Published: August 2007

BACKGROUND.

Lymphatic vessel density (LVD) and microvessel density (MVD) are important parameters for assessing the malignant potential of tumors and patient survival. In this report, the authors defined LVD as the density of D2‐40‐positive lymphatic vessels and MVD as the density of CD105‐positive microvessels per unit area of tissue. It was reported previously that vascular endothelial growth factor C (VEGF‐C) is a major modulator of LVD and MVD. The objectives of this study were to clarify the clinical and prognostic significance of both LVD and MVD in oral squamous cell carcinoma (OSCC) and to elucidate the lymphangiogenic and angiogenic activities of VEGF‐C in cancer tissues.

METHODS.

In total, 110 OSCC tissue samples were evaluated for LVD, MVD, and expression of VEGF‐C using immunohistochemistry. Correlations among these parameters and clinicopathologic factors were examined.

RESULTS.

LVD was significantly higher in tumors that had very high expression of VEGF‐C compared with tumors that had no/weak expression of VEGF‐C. LVD correlated well with lymph node metastasis (P < .001). MVD was correlated significantly with positive lymph node metastasis (P < .001) but not with VEGF‐C expression. In contrast, high expression of VEGF‐C was correlated significantly with advanced tumor status (P = .041). Survival rates were lower in patients who had higher LVD (P < .001), higher MVD (P = .0028), and strong VEGF‐C expression (P = .048).

CONCLUSIONS.

Lymphangiogenesis predominantly influenced metastasis‐free survival. The current results suggested that LVD is a more useful tool than MVD and VEGF‐C for deciding on therapeutic strategies in patients with OSCC. Cancer 2007. © 2007 American Cancer Society.
The Th1 immune response against HIV‐1 Gag p24‐derived peptides in mice expressing HLA‐A02.01 and HLA‐DR1
Authors: Pajot Anthony , Schnuriger Aurélie , Moris Arnaud , Rodallec Audrey , Ojcius David M. , Autran Brigitte , Lemonnier François A. , Lone Yu‐Chun
Published: August 2007

Using HLA‐DR1‐transgenic H‐2 class II knockout mice, we identified two new HLA‐DR1‐restricted HIV‐1 Gag p24‐derived epitopes (Gag321–340 and Gag331–350) and confirmed the immunogenicity of seven that have been previously described. The human relevance was confirmed for the two new ones (Gag321–340 and Gag331–350) assaying peripheral blood mononuclear cells from HLA‐DR1+ HIV‐1‐infected long‐term asymptomatic subjects and showing that Gag331–350 could prime CD4+ T cells from two HLA‐DR1+ HIV‐1 seronegative donors in vitro. Seven of these epitopes, structurally conserved among HIV‐1 clade B isolates, were selected for a comparative evaluation of their Th1 helper potential by immunizing HLA‐A02.01/HLA‐DR1‐transgenic, H‐2 class I/class II knockout mice with recombinant mouse invariant chain constructs in which each helper epitope was inserted in association with two reporter HIV‐1‐derived HLA‐A02.01‐restricted CD8+ T cell epitopes. A T helper effect was demonstrated in all cases, and was particularly strong with epitopes Gag301–320, Gag321–340 and Gag271–290, which should, therefore, be considered in the design of new vaccines.
Synthesis and Reactivity of 23‐tert‐Butyl‐ and 23‐Phenyltetraarylazuliporphyrins: an Analysis of the Effect of Bulky Substituents on Oxidative Ring Contractions to Benzocarbaporphyrins (Eur. J. Org. Chem. 24/2007)
Authors: El‐Beck Jessica A. , Lash Timothy D.
Published: August 2007

The cover picture shows the oxidative ring contraction of tetraphenylazuliporphyrins to give benzocarbaporphyrins. Bulky substituents on the azulene moiety influence the regioselectivity but do not inhibit this unusual chemistry. Details are discussed in the article by J. A. El‐Beck and T. D. Lash on p. 3981 ff.
Prediction of the median IDA curve by employing a limited number of ground motion records
Authors: Azarbakht Alireza , Dolšek Matjaž
Published: August 2007

A methodology has been proposed which can be used to reduce the number of ground motion records needed for the reliable prediction of the median seismic response of structures by means of incremental dynamic analysis (IDA). This methodology is presently limited to predictions of the median IDA curve only. The reduction in the number of ground motion records needed to predict the median IDA curve is achieved by introducing a precedence list of ground motion records. The determination of such a list is an optimization problem, which is solved in the paper by means of (1) a genetic algorithm and (2) a proposed simple procedure. The seismic response of a simple, computationally non‐demanding structural model has been used as input data for the optimization problem. The presented example is a three‐storey‐reinforced concrete building, subjected to two sets of ground motion records, one a free‐field set and the other a near‐field set. It is shown that the median IDA curves can be predicted with acceptable accuracy by employing only four ground motion records instead of the 24 or 30 records, which are the total number of ground motion records for the free‐field and near‐field sets, respectively. Copyright © 2007 John Wiley & Sons, Ltd.
Fate of extrahepatic human stem and precursor cells after transplantation into mouse livers
Authors: Brulport Marc , Schormann Wiebke , Bauer Alexander , Hermes Matthias , Elsner Carolin , Hammersen Friedrich Jakob , Beerheide Walter , Spitkovsky Dimitry , Härtig Wolfgang , Nussler Andreas , Horn Lars Christian , Edelmann Jeanett , Pelz-Ackermann Oliver , Petersen Jörg , Kamprad Manja , von Mach Marc , Lupp Amelie , Zulewski Henryk , Hengstler Jan G.
Published: August 2007

In recent years, a large number of groups studied the fate of human stem cells in livers of immunodeficient animals. However, the interpretation of the results is quite controversial. We transplanted 4 different types of human extrahepatic precursor cells (derived from cord blood, monocytes, bone marrow, and pancreas) into livers of nonobese diabetic/severe combined immunodeficiency mice. Human hepatocytes were used as positive controls. Tracking of the transplanted human cells could be achieved by in situ hybridization with

alu

probes. Cells with

alu

-positive nuclei stained positive for human albumin and glycogen. Both markers were negative before transplantation. However, cells with

alu

-positive nuclei did not show a hepatocyte-like morphology and did not express cytochrome P450 3A4, and this suggests that these cells represent a mixed cell type possibly resulting from partial transdifferentiation. Using antibodies specific for human albumin, we also observed a second human albumin–positive cell type that could be clearly distinguished from the previously described cells by its hepatocyte-like morphology. Surprisingly, these cells had a mouse and not a human nucleus which is explained by transdifferentiation of human cells. Although it has not yet been formally proven, we suggest horizontal gene transfer as a likely mechanism, especially because we observed small fragments of human nuclei in mouse cells that originated from deteriorating transplanted cells. Qualitatively similar results were obtained with all 4 human precursor cell types through different routes of administration with and without the induction of liver damage.

Conclusion:

We observed evidence not for transdifferentiation but instead for a complex situation including partial differentiation and possibly horizontal gene transfer. (Hepatology 2007.)
Key factors in the regulation of fetal and postnatal leydig cell development
Authors: Wu Xiufeng , Wan Shengqin , Lee Mary M.
Published: August 2007

The primary function of testicular Leydig cells is the production of androgens to promote sexual differentiation in the fetus, secondary sexual maturation at puberty, and spermatogenesis in the adult. The fetal and postnatal (adult) populations of Leydig cells differ morphologically and have distinct profiles of gene expression. As postnatal Leydig cells differentiate, they transition through three discrete maturational stages characterized by decreasing proliferative rate and increasing testosterone biosynthetic capacity. In this review, we discuss the development of both fetal and postnatal Leydig cells and review the regulation of this process by some of the key hormones and growth factors. J. Cell. Physiol. 213: 429–433, 2007. © 2007 Wiley‐Liss, Inc.
Isotope tracer investigations of natural products biosynthesis: the discovery of novel metabolic pathways
Authors: Mahmud Taifo
Published: August 2007

Feeding experiments using isotopically labeled precursors remain crucial elements in the study of natural product biosynthesis. Through careful isotope tracer studies, a number of previously unrecognized biosynthetic pathways have now become obvious. One of the remarkable examples is the discovery of the non‐mevalonate pathway in plants, bacteria, algae, and plasmodium, whereas others include the discovery of a new shunt pathway that connects the mevalonate pathway and branched‐chain fatty acids in myxobacteria and the involvement of an unusual HMG‐CoA synthase‐like mechanism in polyketide biosynthesis. Significant progress has also been made in the biosynthetic studies of aminocyclitol‐derived natural products and other bioactive secondary metabolites. This review highlights some of the more recent discoveries of novel mechanisms and metabolic pathways involved in natural product biosynthesis based on isotope tracer experiments. Copyright © 2007 John Wiley & Sons, Ltd.
Effecting change in colleges and universities
Authors: Bruns Jeff W. , Bruns Diana L.
Published: August 2007

Institutional leaders often try to use theories to rethink or resolve organizational challenges. Bolman and Deal (2003) describe four organizational frames (structural, human resource, political, and symbolic) to understand and diagnose problems within any organization. A classic organizational challenge in higher education is the status quo or conservatism relating to change of faculty involvement in institutional decision making. Leaders in higher education recognize the need for change but are often uncertain how to facilitate it or lack an understanding of how to implement it. The use of multiple theoretical frameworks can assist leaders in diagnosing dilemmas and instigating change.
Separation of three water‐soluble vitamins by poly(dimethylsiloxane) microchannel electrophoresis with electrochemical detection
Authors: Li Xiang‐Yun , Zhang Qian‐Li , Lian Hong‐Zhen , Xu Jing‐Juan , Chen Hong‐Yuan
Published: August 2007

A method for rapid separation and sensitive determination of three water‐soluble vitamins, pyridoxine, ascorbic acid (VC), and p‐aminobenzoic acid (PABA) has been developed by PDMS microchannel electrophoresis integrated with amperometric detection. After treatment of the microchip with oxygen plasma, the peak shapes of the three analytes were essentially improved. Pyridoxine, VC, and PABA were well separated within only 80 s in a running buffer of 20 mM borate solution (pH 8.5). Good linearity was obtained within the concentration range of 2–200 μM for the three water‐soluble vitamins. The detection limits were 1.0 μM for pyridoxine and VC, and 1.5 μM for PABA. The proposed method has been successfully applied to real human urine sample, without solid phase extraction, with recoveries of 80–122% for the three water‐soluble vitamins.
Double‐Grafted Cylindrical Brushes: Synthesis and Characterization of Poly(lauryl methacrylate) Brushes
Authors: Xu Youyong , Becker Harald , Yuan Jiayin , Burkhardt Markus , Zhang Yong , Walther Andreas , Bolisetty Sreenath , Ballauff Matthias , Müller Axel H. E.
Published: August 2007

Double‐grafted cylindrical brushes with poly(lauryl methacrylate) (PLMA) as the side chains were synthesized using the grafting‐from strategy via atom transfer radical polymerization (ATRP). The polyinitiator poly[2‐(2‐bromoisobutyryloxy)ethyl methacrylate] (PBIEM) with $\overline {DP} _{\rm n}$ = 240 and 1 500 served as the backbone. The PLMA side chains of the brushes carry long alkyl chains. GPC and 1H NMR measurements confirmed the successful formation of the PLMA cylindrical brushes. The side chains were cleaved from the cylindrical brushes by transesterification. GPC and 1H NMR results indicate that the initiating efficiency of the bromoester groups on the backbone for the bulky monomer was in the range of 0.34 ≤ f ≤ 0.67. Static and dynamic light scattering show that the ratio of the radius of gyration to the hydrodynamic radius, Rg/Rh, is in the range of 1.2–1.3, indicating that the LMA cylindrical brushes are semiflexible in solution. Atomic force microscopy (AFM) measurements show that short PLMA brushes exhibit a spherical morphology while the long brushes exhibit a worm‐like structure. DSC displayed melting peaks at around −30 °C, indicating the alkyl side chains of the PLMA chains in the double‐grafted cylindrical brushes are crystallizable.

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Effects of Acceptors on the Electronic and Optoelectronic Properties of Fluorene‐Based Donor–Acceptor–Donor Copolymers
Authors: Lee Wen‐Ya , Cheng Kai‐Fang , Wang Then‐Fu , Chueh Chu‐Chen , Chen Wen‐Chang , Tuan Chih‐Shen , Lin Jen‐Lien
Published: August 2007

In this study, four fluorene‐based conjugated copolymers were synthesized to explore the acceptor effects on the electronic and optoelectronic properties. The studied polymers were poly{[2,7‐(9,9‐dihexylfluorene)]‐alt‐[2,2′:5,2″‐terthiophene]} (PFTT) and its derivatives of poly{[2,7‐(9,9′‐dihexylfluorene)]‐alt‐[2,3‐dimethyl‐5,7‐dithien‐2‐yl‐quinoxaline]} (PFDDTQ), poly{[2,7‐(9,9′‐dihexylfluorene)]‐alt‐[4,7‐dithien‐2‐yl‐2,1,3‐benzothiadiazole]} (PFDTBT), and poly{[2,7‐(9,9′‐dihexylfluorene)]‐alt‐[2,3‐dimethyl‐5,7‐dithien‐2‐yl‐thieno[3,4‐b]pyrazine]} (PFDDTTP) with the acceptors of quinoxaline (Q), 2,1,3‐benzothiadiazole (BT), and thieno[3,4‐b]pyrazine (TP), respectively. The order of the band gap was PFDTTP < PFDTBT < PFDDTQ < PFTT, which was on the reverse trend of emission maximum and field‐effect transistor (FET) mobility. The strong acceptor strength of the TP moiety and coplanar backbone in PFDTTP resulted in the highest intramolecular charge transfer (ICT) among the four polymers. The FET mobility of PFDTTP could be varied by two orders of magnitude through the solvent quality. The present study suggested the importance of the acceptor structure on the electronic and optoelectronic properties of semiconducting polymers.

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Inclusion Complex Formation of Cellulose in NaOH–Thiourea Aqueous System at Low Temperature
Authors: Lue Ang , Zhang Lina , Ruan Dong
Published: August 2007

It is puzzling that cellulose could be dissolved rapidly in 9.5 wt.‐% NaOH/4.5 wt.‐% thiourea aqueous solution pre‐cooled to −5 °C, but it could not be dissolved in the same solvent mixture without prior cooling. To understand this phenomenon, changes in the structure and properties of NaOH and thiourea in water as well as solution behaviors of cellulose in the solvent at low temperatures were investigated by means of 13C NMR, Fourier transform infrared spectroscopy, wide‐angle X‐ray diffraction, transmission electron microscopy (TEM), and viscometry. The results indicated that an association of NaOH and thiourea in water through the hydrogen bonding strengthened with a decrease in temperature. The low temperature created a new hydrogen‐bonded network structure associated with NaOH, thiourea, water cluster, and cellulose, leading to the cleaving of the close chain packing of cellulose. The results proved that a good dispersion of cellulose occurred at a low temperature as a result of the formation of an inclusion complex (IC) hosted by thiourea and NaOH, in which cellulose chain associated with NaOH hydrates as guest was encaged. IC could aggregate to form a sphere having a mean size of 60–160 nm. TEM observations, for the first time, revealed the shape and size of IC and its aggregate. The stability of the cellulose solution could be related to the thiourea IC.

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Application of FT Rheology to Industrial Linear and Branched Polyethylene Blends
Authors: Vittorias Iakovos , Wilhelm Manfred
Published: August 2007

Numerous analytical techniques are used to quantify branching topologies in polyethylene. One of these methods, FT rheology, studies the higher harmonic contributions of the stress response to large amplitude oscillatory shear deformation. The sensitivity of FT rheology in the presence of sparse long‐chain branched chains blended with linear ones is addressed. FT rheology is sensitive even for small concentrations of a partly long‐chain branched component blended with a linear melt (1.5–5 wt.‐%). The non‐linear parameters present a strong dependence on the fraction of long‐chain branched species in a polydisperse melt, the miscibility of which is confirmed via rheological techniques.

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A hyperbolic reaction–diffusion model for the hantavirus infection
Authors: Barbera E. , Currò C. , Valenti G.
Published: August 2007

A hyperbolic reaction–diffusion model for the hantavirus infection, generalizing the parabolic set of equations recently derived by Abramson and Kenkre, is proposed within the context of Extended Thermodynamics. The model, as in the parabolic case, captures some of the realistic features of the dynamics of hantavirus in mice population, while it avoids the unphysical features concerning the instantaneous diffusive effects typical of parabolic equations. Traveling wave solutions, related to the spread of the infection in the landscape, are investigated. Both analytical and numerical results obtained herein are discussed and validated from the behavior of the biological system. Copyright © 2007 John Wiley & Sons, Ltd.
Tournaisian (Early Carboniferous/Mississippian) ammonoids from the Ma'der Basin (Anti-Atlas, Morocco)
Authors: Ebbighausen V. , Bockwinkel J.
Published: August 2007

Abstract. Three succeeding assemblages of Early Tournaisian (Mississippian) ammonoids are described from Fezzou (Ma'der) in the Anti-Atlas of Morocco; they are, in ascending order, composed of the following genera: (1) Gattendorfia-Eocanites Assemblage: Acutimitoceras, Costimitoceras, Imitoceras, Kornia, Gattendorfia, Kazakhstania, and Eocanites; (2) Gattendorfia-Kahlacanites Assemblage: Acutimitoceras, Hasselbachia, Gattendorfia, Becanites, and Kahlacanites; and (3) Goniocyclus-Protocanites Assemblage: Globimitoceras, Imitoceras, Gattendorfia, Goniocyclus, Eocanites, and Protocanites. The following taxa are newly described: Globimitoceras rharrhizense n. sp., Acutimitoceras sarahae n. sp., A. endoserpens n. sp., A. pentaconstrictum n. sp., Costimitoceras aitouamar n. sp., Hasselbachia arca n. sp., Kornia citrus n. gen. n. sp., Gattendorfia lhceni n. sp., and G. gisae n. sp. Drei aufeinander folgende Vergesellschaftungen von Ammonoideen aus dem Tournaisium (Mississippium) werden von Fezzou (Ma'der) im Anti-Atlas von Marokko beschrieben; diese werden, in aufsteigender Reihenfolge, durch die folgenden Gattungen zusammen gesetzt: (1) Gattendorfia-Eocanites Assemblage: Acutimitoceras, Costimitoceras, Imitoceras, Kornia, Gattendorfia, Kazakhstania und Eocanites; (2) Gattendorfia-Kahlacanites Assemblage: Acutimitoceras, Hasselbachia, Gattendorfia, Becanites und Kahlacanites; und (3) Goniocyclus-Protocanites Assemblage: Globimitoceras, Imitoceras, Gattendorfia, Goniocyclus, Eocanites und Protocanites. Die folgenden Taxa werden neu beschrieben: Globimitoceras rharrhizense n. sp., Acutimitoceras sarahae n. sp., A. endoserpens n. sp., A. pentaconstrictum n. sp., Costimitoceras aitouamar n. sp., Hasselbachia arca n. sp., Kornia citrus n. gen. n. sp., Gattendorfia lhceni n. sp. und G. gisae n. sp. doi:10.1002/mmng.200700003
A study on the lumped preconditioner and memory requirements of FETI and related primal domain decomposition methods
Authors: Fragakis Yannis
Published: August 2007

In recent years, domain decomposition methods (DDMs) have emerged as advanced solvers in several areas of computational mechanics. In particular, during the last decade, in the area of solid and structural mechanics, they reached a considerable level of advancement and were shown to be more efficient than popular solvers, like advanced sparse direct solvers. The present contribution follows the lines of a series of recent publications on the relationship between primal and dual formulations of DDMs. In some of these papers, the effort to unify primal and dual methods led to a family of DDMs that was shown to be more efficient than the previous methods. The present paper extends this work, presenting a new family of related DDMs, thus enriching the theory of the relations between primal and dual methods, with the primal methods, which correspond to the dual DDM that uses the lumped preconditioner. The paper also compares the numerical performance of the new methods with that of the previous ones and focuses particularly on memory requirement issues related to the use of the lumped preconditioner, suggesting a particularly memory‐efficient formulation. Copyright © 2007 John Wiley & Sons, Ltd.
Rotational molding cycle time reduction through surface‐enhanced molds, Part B: Experimental study
Authors: Abdullah M.Z. , Bickerton S. , Bhattacharyya D.
Published: August 2007

Rotational molding is a process used to manufacture hollow plastic products, and has been heralded as a molding method with great potential. Because of long production cycle times, which are limited by the time required to heat‐up and cool‐down the mold and the product, its productivity is hampered. To address this issue, exterior mold modification techniques (i.e. the application of extended and rough surfaces) have been employed to enhance heat transfer to and from molds, ultimately reducing cycle times. Extended surfaces have the potential to enhance heat transfer by increasing the surface area. Roughness elements are utilized in conjunction with turbulent flows, also producing significant increases in heat transfer rates. Experimental results presented here demonstrate very significant cycle time reductions through the use of surface‐enhanced molds. The experimental savings are in the order of 18 and 28%, whereas the predicted cycle time reductions are around of 21 and 32% for roughness‐enhanced and pin‐enhanced molds, respectively. Although the prediction methods have been unable to forecast the exact experimental cycle times very accurately, they have proved to be useful for predicting the approximate cycle time reductions and the relative rankings of the plain and the surface‐enhanced molds. POLYM. ENG. SCI., 47:1420–1429, 2007. © 2007 Society of Plastics Engineers
Cis/trans configurations of the peptide CN bonds: isomerization and photoswitching
Authors: Micheau Jean‐Claude , Zhao Jianzhang
Published: August 2007

Cis/trans isomerization of peptide CN bonds is involved in the configurational changes and are definitive for the bioactivity of peptides and proteins. The basic molecular character and origin of the restricted rotation of the peptide CN bonds are briefly introduced, as well as the methods used for study of the cis/trans isomerization, such as the chymotrypsin‐coupled assay, pH‐mediated solvent jump, and UV‐resonance Raman spectroscopy, etc. The control of the peptide bond configuration with photoresponsive (photochromic) groups such as azobenzene or thioamide bonds is also reviewed. Copyright © 2007 John Wiley & Sons, Ltd.
Primary 1H/2H isotope effect in the NMR chemical shift of HClO4 salts of 1,8‐bis(dimethylamino)naphthalene derivatives
Authors: Chmielewski Piotr , Ozeryanskii Valery A. , Sobczyk Lucjan , Pozharskii Alexander F.
Published: August 2007

The primary 1H/2H isotope effect for a number of protonated naphthalene proton sponges (DMAN‐s) was measured and correlated with the δ(1H) value and IR spectroscopic characteristics of the [NHN]+ hydrogen bonds. A particular role of the unusual anharmonicity expressed in the isotopic ratio ISR ≫$\sqrt 2 $ is discussed when the fundamental vibrational levels are close to the barrier top for proton/deuteron motion. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and structural study of 2′‐ and 2′,6′‐positioned methyl‐ and nitro‐substituted 3‐(arylhydrazono)pentane‐2,4‐diones
Authors: Marten Jan , Seichter Wilhelm , Weber Edwin , Böhme Uwe
Published: August 2007

A systematic series of ortho‐methyl‐ and nitro‐substituted arylhydrazones 2–6 formed by Japp–Klingemann reaction between pentane‐2,4‐dione and the respective aryldiazonium salts have been synthesized and studied by X‐ray crystal structure analysis, with added quantum chemical calculations. The optimized molecular geometries based on DFT calculations, enabling determination of relevant rotational barriers, and the calculated bond and ring critical points, using the method of ‘atoms in molecules’, were found to correspond with the experimental data, involving specific molecular conformations and hydrogen‐bonded ring structure dependent on the ortho‐substitution, thus making possible reliable structural prediction of this compound class. Copyright © 2007 John Wiley & Sons, Ltd.
Transparent conducting antimony‐doped tin oxide films containing functionalized multi‐walled carbon nanotubes
Authors: Castro M. R. S. , Schmidt H. K.
Published: August 2007

In order to improve the conductivity of Sb:SnO2 (ATO) films, very thin multi‐walled carbon nanotubes (MWNTs) functionalized with –NH2 and –COOH groups have been investigated. The new nanocomposites were prepared by the addition of such MWNTs pre‐dispersed in a cationic surfactant (Hexadecyl‐trimethyl ammonium chloride) in the ATO sol at concentrations of 0.05 and 0.1 wt%. Coatings of pure ATO and nanocomposites were prepared by spin coating on borofloat glass substrates. Experiments show‐ ed that all coatings containing nanotubes present resistivities of the order of 10–1 to 10–2 Ω cm while pure ATO films prepared under the same conditions show resistivities which are about 16 times higher. Optical transmission in the visible range of all systems studied was about 90%. The results indicate the suitability of MWNTs as additives for enhancing electrical properties of transparent conductive coatings. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Landau–Zener theory for avoided crossings applied to the gallium–silane reactions
Authors: Pacheco‐Sánchez J. H. , Castillo S. , Luna‐García H. , Novaro O.
Published: August 2007

Landau–Zener Theory for avoided crossings is applied here to obtain the transition probabilities (TPs) for the lowest Gallium–Silane excited states. Considering that silane orbits the gallium atom when the insertion angle θ is used as the reaction parameter, the translational energy is for this purpose irrelevant. The nonadiabatic TP depends on the angular velocity; hence, the inertia moment is more pertinent than the mass. Avoided crossings of the two lower A′ potential energy surfaces of Ga(2P,2S) + SiH4 interactions have to be taken into account. The TP of the excited system HGaSiH3 leading from one potential energy surface to another through an avoided crossing is then calculated. TPs for gallium–silane interaction are predicted using this novel approach. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Schweißen ermüdungsbeanspruchter Altstahlkonstruktionen – Untersuchungen zum Einfluss der Vorbelastung auf die Lebensdauer der Schweißkerbdetails
Authors: Lüddecke Falk , Mehdianpour Milad , Graße Wolfgang
Published: August 2007

Für die Sanierung und Ertüchtigung bestehender, vorwiegend nicht ruhend beanspruchter Stahltragwerke mittels Schweißen ist bei der ingenieurmäßigen Bemessung neu eingebrachter Schweißverbindungen der Nachweis der Betriebsfestigkeit zu führen. Um für die Restlebensdauerermittlung den Anteil der vergangenen ermüdungsrelevanten Belastung abschätzen zu können, wurden experimentelle Untersuchungen durchgeführt. Hierbei erfolgte u.a. die Einprägung einer definierten Vorbelastung in einen äußerlich ungekerbten Grundwerkstoff, anschließend die Kerbung und die Ermüdungsbeanspruchung der Probe bis zum Bruch. Dieses Vorgehen repräsentiert einen bereits vorbelasteten Altstahl, an dem nachträglich eine Reparatur durchgeführt wurde. Aus den Ergebnissen lässt sich ableiten, dass die aufgebrachten Vorbelastungen in der Regel keinen signifikanten Einfluss auf die erreichbare Lebensdauer ausüben, wenn eine Oberflächenbearbeitung durchgeführt und ein ausreichender Einbrand gewährleistet wird. Dies bedeutet, dass die eingeprägte Vorgeschichte bestehender Konstruktionen beim Nachweis der Betriebsfestigkeit von neu eingebrachten Schweißkerbdetails vernachlässigt werden kann.
Doppelwaagebalkenbrücke – Vorschlag für einen innovativen Klappbrückentyp
Authors: Saul Reiner , Humpf Karl
Published: August 2007

Waagebalkenbrücken wurden bisher immer als Einfeldträger ausgeführt, wobei sich die Überspannung wegen der gelenkigen Lagerung des Waagebalkens nur an der Abtragung der ständigen Last beteiligt. Wird dagegen die Verdrehung durch ein zweites Lager blockiert, wirkt die Überspannung auch an der Abtragung der Verkehrslasten mit. Dies ermöglicht es, Waagebalkenbrücken mit zwei Klappen auszuführen und damit den Stützweitenbereich zu verdoppeln.
Bemessung von strukturellen Silikon‐Klebungen
Authors: Hagl Anneliese
Published: August 2007

Was ist erforderlich, wenn die Fügetechnik Kleben im konstruktiven Glasbau anwendet wird? Was sind die Gründe dafür, dass – obwohl der Werkstoff Silikon seit 40 Jahren bekannt ist – noch immer von einer Innovation gesprochen wird, wenn tragend mit Silikon geklebt wird? Was muss ein Ingenieur wissen, der sich an eine Bauaufgabe wagt, bei der er die Möglichkeit einer tragenden Verklebung ins Auge fasst?

Offensichtlich fehlt hier das Wissen über die Tragmechanismen komplexerer Verklebungen, und es fehlen einfache Dimensionierungsmethoden, die helfen, bereits im Vorfeld einer genaueren Berechnung und/oder Versuchsdurchführung mit Hilfe einer einfachen Handrechnung das Tragpotential einer Verklebung abzuschätzen.

Dieser Aufsatz hat das Ziel, an Hand von aktuellen Ergebnissen des Forschungsvorhabens “Geklebte Verbindungen im Glasbau” [1] der Fachhochschule München die Wirkungsweise komplexerer Verklebungsgeometrien aufzuzeigen und ein einfaches überschlägiges Bemessungskonzept vorzustellen.
Typical costs of seismic rehabilitation of existing buildings
Authors: Hart Gary C. , Srinivasan Mukund
Published: August 2007

This paper presents the methodology used in a FEMA‐funded study to develop a tool for structural engineers and decision makers to use to make estimates for the typical costs for seismic rehabilitation of existing buildings. Copyright © 2007 John Wiley & Sons, Ltd.
“Instantaneous” sulfation of fatty alcohols
Authors: Whyte David D.
Published: July 2007

Conclusions

A continuous process has been developed for sulfating fatty alcohols with sulfuric acid up to 100% H2SO4concentration.

The success of the process depends on maintaining a proper balance among the factors of temperature, reaction time, acid strength, and acid usage.

In general, best results accrue from use of as strong acid as is permissible (99% in plant operations), about 160°F. and 10 seconds reaction time.

Neutralization is quite simple, requiring only efficient mixing and adequate heat removal.
Sesamin, sesamolin, and sesamol content of the oil of sesame seed as affected by strain, location grown, ageing, and frost damage
Authors: Beroza Morton , Kinman Murray L.
Published: July 2007

The effect of strain and location grown on the sesmin, sesamolin, and sesamol content of oils from sesame seed chosen to represent a wide variety of genetic material is reported. Only differences in sesamin content due to strain were significant.

Three of four oils exposed as the oil to 100°F. became rancid in two to three months. Rancidity of the oil was accompanied by lesser sesamin and sesamolin contents, and the ultraviolet spectrum of the oil was much altered. Oil from seed exposed as the seed to the same conditions for six months did not become rancid even though most of the seeds were damaged in threshing. The sesamol content of all the oils subjected to the accelerated ageing procedure increased, but the increase was greatest in the rancid oils.

Frost damage of sesame seed markedly diminished the sesamin and sesamolin content of the oil.
A rapid method for the estimation of unsaturation of fats and oils by use of hypochlorous acid reagent
Authors: Mukherjee S.
Published: July 2007

A rapid method for the determination of unsaturation of oils and fats containing non‐conjugated ethylenic linkages has been developed, using hypochlorous acid as the reagent. The method has several advantages,viz., that the estimation is conducted with an aqueous solution of sodium hypochlorite reagent, and moreover no oil solvent is required for the estimation. In all the methods currently employed, the reagents used must be perfectly anhydrous otherwise incomplete addition will take place, giving low results. Since a reaction time of 4 to 5 min. is recommended, the estimations are much more rapid than the customary Wijs or Hanus methods. No discrimination as to time factor need be made for oils possessing different degree of saturation. All oils, whether belonging to non‐drying or drying groups, give accurate results within the specified time. There is no secondary reaction except in the case of castor oil, but even in that case the secondary reactions are not appreciable within the first hour of reaction. The present method compares favorably with the standard procedures currently employed for determination of unsaturation.
Low temperature solubilities of fatty acids in selected organic solvents
Authors: Kolb Doris K. , Brown J. B.
Published: July 2007

A number of highly purified fatty acids have been prepared and their solubilities determined in six common organic solvents within the temperature range from 10° to −70°. The acids studied were palmitic, stearic, oleic, elaidic, petroselinic, petroselaidic, linoleic, stearolic, arachidic, eicosenoic, behenic, erucic, and brassidic. The solvents used were methanol, ethyl acetate, diethyl ether, acetone, toluene, and n‐heptane, representing six different solvent types. A limited study was also made with a series of hydrocarbon solvents in order to note any effects of solvent structure on fatty acid solubility. Data are discussed with respect to their application in separating various fatty acid mixtures by low temperature crystallization.
Vicinally unsaturated hydroxy acids in seed oils
Authors: Morris L. J. , Holman R. T. , Fontell K.
Published: July 2007

The interference of certain unsaturated hydroxy acids in the Durbetaki method of epoxide determination has been demonstrated. The concentrations of these constituents were determined concurrently with those of epoxy components by measurement of the near infrared spectra of samples before and after treatment with anhydrous ethereal hydrogen chloride. The individual hydroxy esters were separated and isolated from samples of mixed esters by thinlayer chromatography. GLC of these esters resulted in their alteration to conjugated trienoates and gave proof of their conjugated diene hydroxyl structure. Thin‐layer chromatographic and infrared studies verified theTrans‐trans diene unsaturation of the acid fromDimorphotheca aurantiaca oil and showed that the other hydroxy compounds examined have acistrans diene system. These data suggest that the seed oils ofArtemisia absinthium, Calliandra eriophylla, Balanites aegyptica, Cosmos bipinnatus, and Helianthus annuus contain 9‐hydroxy‐trans‐10‐cis‐12‐ and 13‐hydroxy‐cis‐9‐trans‐11‐octadecadienoic acids.
Chromatographic isolation of the original constituents of natural waxes. The composition of ouricuri wax
Authors: Cole Leslie J. N. , Brown J. B.
Published: July 2007

A chromatographic method was developed which separated a known mixture of alleged wax constituents into four groups,viz., dotriacontane, octadecyl stearate and stearone, octadecanol, and stearic acid on especially prepared alumina. This adsorbent, when prepared fresh, did not give a satisfactory separation of spermaceti wax. On re‐use after regeneration by exhaustive washing with methanol and water, spermaceti wax was resolved into esters (95.4%), alcohols (2.6%), and acids (1.2%). A resolution of ourieuri wax into four major classes (nine fractions) was obtained on alumina (M. Woelm, aniontrophie, pII4) of lesser adsorptive activity than the two previous preparations. Two of the latter fractions were further resolved on silica gel. There isa priori evidence that the constitutents of natural plant waxes do not conform rigidly to the pattern of mixtures of simple normal esters. An estimated composition of ouricuri wax (in per cent) is hydrocarbons 1.3, simple esters 23.5, hydroxy‐mono‐esters 22.4, hydroxy‐di‐esters 17.2, hydroxy‐aeidie‐poly‐esters 5.4, free acids 8.7, free alcohols 3.0, resins 14.8, moisture 1.4, and ash 0.4.
Gas‐liquid chromatography of fatty derivatives
Authors: Link W. E. , Morrissette R. A. , Cooper A. D. , Smullin C. F.
Published: July 2007

The separation of fatty amines has been carried out with nonpolar substrates on solid supports of Chromosorb and Chromosorb W, which were previously treated with potassium hydroxide to overcome adsorptivity. In this manner well‐resolved symmetrical peaks are obtained. Untreated supports give peaks which trail and prohibit precise quantitative measurements. Both Apiezon L on Chromosorb W and Silicone Grease on Chromosorb have proved effective, the latter at 176°C. and the former at 225°C. Relative detector sensitivity factors have been determined for the amines C8 to C18, thus permitting accurate analyses. The relative response for primary alkyl fatty amines is a linear function of molecular weight.
Acidolysis of vegetable and marine oils with phthalic acids
Authors: Carlston E. F.
Published: July 2007

The interchange reaction of the three phthalic acid isomers with triglyceride oils at high temperatures was studied. Orthophthalic acid dehydrates to the anhydride before any interchange occurs, but isophthalic and terephthalic acids are heat‐stable and react easily with oils in the temperature range of 260–300°C. Isophthalic acid reacts more rapidly than terephthalic acid and is ideal for use in acidolysis processes of alkyd‐resin manufacture. Various methods of application of the acidolysis reaction to isophthalic alkyd resin preparation were studied, and the minimum of oil conversion to monobasic acids that is required for successful alkyd preparation was found. Under certain conditions the acidolysis reaction occurs simultaneously with esterification; use is made of this fact to improve the process. Commercial use of the acidolysis reaction in alkyd‐resin manufacture is economically attractive because it is noncatalytic; therefore no catalyst residues need to be removed by pressure filtration. Another advantage is that glycerol is readily pumped into hot acidolysis‐reaction mixtures without opening the kettle, and this eliminates the disagreeable and toxic fumes that escape from hot kettles when they are opened after alcoholysis for addition of solid phthalic anhydride or isophthalic acid.

Applications of acidolysis in conjunction with oil polymerization, fish oil upgrading, and castor oil dehydration were studied briefly, and the results suggest that further work in these fields is desirable.
Conversion of some C14‐labelled compounds into the neutral lipid ofNeurospora crassa
Authors: Krzeminski Leo F. , White Harold B. , Quackenbush F. W.
Published: July 2007

Conidia‐free mycelia ofNeurospora crassa converted C14‐acetate into neutral lipid more efficiently than C14‐labelled mevalonic acid or six other compounds tested. Pyruvate, glucose, and alanine contributed little to the neutral lipid fraction, but that contribution was mainly as fatty acids. Substantial losses of C14 as carbon dioxide indicated that all of the labelled compounds participated in cell metabolism.

Analysis of the fatty acids esterified to the neutral lipid of unlabelled mycelia showed that palmitic, oleic, and linoleic acids each comprised nearly one‐third of the total while stearic, palmitoleic, and a small amount of unidentified acids contributed the remainder.
Polymerization of linseed oil in an electric discharge
Authors: Boelhouwer C. , Hoekstra T. , Waterman H. I. , Westerdijk J. B. , Van Dam J. , Kruidenier A. J.
Published: July 2007

The treatment of linseed oil by the action of electric discharges (voltolization) in a hydrogen atmosphere (80 mm. Hg, 70°C.) is described.

It has been known for a long time that voltolization of linseed oil brings about a polymerization of the oil. Now it has been proven that the nature of the polymerization product thus obtained is absolutely different from that of thermally or catalytically polymerized linseed oils.

In contrast to the latter, voltolized linseed oils contain only small amounts of cyclic compounds. Their viscosity is relatively low, even at a high polymerization degree, and considerably less than that of thermally polymerized oils of a corresponding degree of polymerization.

Atomic hydrogen seems to play an important part in the voltolization process. Coupling of fatty acid chains is made possible by combining radicals, formed primarily by the action of hydrogen atoms. Coupling reaction occurs almost exclusively intermolecularly.

The possibility of transforming linseed oil and other drying oils into polymerization products of a completely different chemical structure, depending on the applied polymerization process, opens new possibilities for their manufacture.
Marketing and economics of fatty alcohols
Authors: Houston Colin A.
Published: July 2007

Alcohols represent 35% of the world's major surfactant intermediates, with natural alcohols accounting for one‐third of that percentage. Present trends suggest, however, that alcohols will become increasingly important in the detergent industry (the primary market for surfactants) during the next 10 years. Moreover, natural alcohols will frequently have an economic advantage over synthetics. Factors contributing to the growth of alcohols as surfactant intermediates include: better derivative biodegradability (especially compared to alkylbenzenes), better solubility (for use in low‐temperature washing and in liquid detergents), better hard‐water tolerance (for use in unbuilt liquid detergents), and a reputation for better detergency on synthetic fabrics. Factors favoring the natural alcohols (as opposed to the synthetics) include: frequently favorable raw material economics (especially as supplies of lauric oils increase), and integration of major manufacturers.
Marketing and economics of oleochemicals to the oil patch
Authors: LaSusa C. D.
Published: July 2007

Oleomines represent the largest class of oleochemicals used in the oil patch and are used in virtually all phases of the oil industry. Although the largest volume is used in production and refining, many amines are used prior to production in drilling operations and well completions, as well as postprocessing as additives in finished products. Other oleochemicals widely used include various surfactants made by ethoxylation and sulfation of fatty acids as well as polymerized fatty acids. The amines of interest start with simple primary amines and include secondary, tertiary and quaternary amines. They extend into higher amines such as diamines, triamines and beyond as well as all of these further reacted with other chemical species. Oleoamines in a generic sense also include amino amides, amphoteric amines, cyclic amidines, ether amines, as well as some high molecular weight polymeric materials. The oleoamines are used per se in suitable solvent systems, or as components in a wide variety of finished products containing several chemical entities to obtain specified product properties. Oleoamines, their derivatives, and other oleochemicals are used to prevent corrosion, inhibit and kill bacteria, condition waters for improved injectivity, emulsify, deemulsify, foam, gel, remove deposits, disperse solids, wet solids, solubilize or disperse otherwise incompatible liquids, produce or stabilize foaming systems, lubricate and produce detergent properties in liquid systems. They are used in drilling fluids. well completion fluids, oil and gas wells, water source wells, injection wells, gathering systems, filters, storage tanks, pipelines, refineries, and in finished products for all of the purposes listed above. This paper covers the oil patch operating parameters that determine the need for using oleochemicals, and describes for each system appropriate oleochemicals whose properties satisfy those needs.