bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Formation of Byproducts in the Autoxidation of Cyclohexane
Authors: Hermans Ive , Jacobs Pierre , Peeters Jozef 
Published: December 2006

AbstractIn this work, a complementary experimental and theoretical approach is used to unravel the formation of byproducts in the autoxidation of cyclohexane. The widely accepted vision that cyclohexanone would be the most important precursor of undesired products was found inconsistent with several experimental observations. However, the propagation reaction of cyclohexyl hydroperoxide, which we recently put forward as the missing source of cyclohexanol and cyclohexanone, is now unambiguously identified also as the dominant path leading to byproducts. Indeed, this overlooked reaction produces large amounts of cyclohexoxy radicals, able to ring‐open via a β‐CC cleavage to ω‐formyl radicals. The pathway by which these radicals are converted into the observed and quantified byproducts is derived in this work. In this liquid‐phase reaction, solvent cages were found very important, steering the fate of nascent species.
Two‐Component Supramolecular Helical Architectures: Creation of Tunable Dissymmetric Cavities for the Inclusion and Chiral Recognition of the Third Components
Authors: Kodama Koichi , Kobayashi Yuka , Saigo Kazuhiko 
Published: December 2006

AbstractThe inclusion and chiral recognition of racemic arylalkanols by supramolecular helical architectures consisting of enantiopure primary amines and achiral carboxylic acids were thoroughly studied. Among the architectures examined, a supramolecular helical architecture composed of the salt of enantiopure erythro‐2‐amino‐1,2‐diphenylethanol (1 b) and benzoic acid (2 a) was found to include a wide variety of racemic arylalkanols with recognition of their chirality. The helical architecture gave a dissymmetric 1D groove in the salt crystal, and the arylalkanols were enantioselectively included in the groove. The size and shape of the groove were tunable by proper selection of the achiral carboxylic acid component. The origin of the chiral recognition with the combination 1 b/2 a is discussed on the basis of X‐ray crystallographic analyses.
Synthesis, Manipulation and Conductivity of Supramolecular Polymer Nanowires
Authors: Dong Liqin , Hollis Tom , Fishwick Steven , Connolly Bernard A. , Wright Nicholas G. , Horrocks Benjamin R. , Houlton Andrew 
Published: December 2006

AbstractThe synthesis of supramolecular conducting nanowires can be achieved by using DNA and pyrrole. Oxidation of pyrrole in DNA‐containing solutions yields a material that contains both the cationic polypyrrole (PPy) and the anionic DNA polymers. Intimate interaction of the two polymer chains in the self‐assembled nanowires is indicated by FTIR spectroscopy. AFM imaging shows individual nanowires to be continuous, ≈5 nm high and conformationally flexible. This feature allows them to be aligned by molecular combing in a similar manner to bare DNA and provides a convenient method for fabricating a simple electrical device by stretching DNA/PPy strands across an electrode gap. Current–voltage measurements confirm that the nanowires are conducting, with values typical for a polypyrrole‐based material. In contrast to polymerisation of pyrrole on a DNA template in bulk solution, attempts to form similar wires by polymerisation at surface‐immobilised DNA do not give a continuous coverage; instead, a beads‐on‐a‐string appearance is observed suggesting that immobilisation inhibits the assembly process.
Inhibitory Effect of Umbelliferone Aminoalkyl Derivatives on Oxidosqualene Cyclases from S. cerevisiae, T. cruzi, P. carinii, H. sapiens, and A. thaliana: a Structure–Activity Study
Authors: Oliaro‐Bosso Simonetta , Viola Franca , Taramino Silvia , Tagliapietra Silvia , Barge Alessandro , Cravotto Giancarlo , Balliano Gianni 
Published: December 2006

AbstractEighteen coumarin derivatives were tested as inhibitors of oxidosqualene cyclases (OSCs) from Saccharomyces cerevisiae, Trypanosoma cruzi, Pneumocystis carinii, Homo sapiens, and Arabidopsis thaliana, all expressed in an OSC‐defective strain of S. cerevisiae.35 All the compounds have an aminoalkyl chain bound to an aromatic nucleus; unconventional synthetic procedures (microwave‐ and ultrasound‐promoted reactions) were successfully used to prepare some of them. The most interesting structure‐dependent difference in inhibitory activities was observed with an N‐oxide group replacement of the tertiary amino group at the end of the side chain. An interesting species specificity also emerged: T. cruzi OSC was the least sensitive enzyme; P. carinii and A. thaliana OSCs were the most sensitive. The remarkable activities of three compounds on the T. cruzi enzyme and of five of them on the P. carinii enzyme suggest the present series as a promising compound family for the development of novel antiparasitic agents.
Development of an ovarian cancer symptom index
Authors: Goff Barbara A. , Mandel Lynn S. , Drescher Charles W. , Urban Nicole , Gough Shirley , Schurman Kristi M. , Patras Joshua , Mahony Barry S. , Andersen M. Robyn 
Published: December 2006

AbstractBACKGROUND.Currently, screening for ovarian cancer is not recommended for the general population. Targeting women with specific symptoms for screening has been evaluated only recently, because it was believed that symptoms had limited specificity.METHODS.A case‐control study of 149 women with ovarian cancer, including 255 women who were in a screening program and 233 women who were referred for pelvic/abdominal ultrasound, was conducted by inviting women to complete a survey of symptoms. Patients were divided randomly into an exploratory group and a confirmatory group. Symptom types, frequency, severity, and duration were compared between cases and controls. Logistic regression analyses were used to determine which factors independently predicted cancer in the exploratory group and then were used to develop a symptom index, which was tested for sensitivity and specificity in the confirmatory group.RESULTS.Symptoms that were associated significantly with ovarian cancer were pelvic/abdominal pain, urinary urgency/frequency, increased abdominal size/bloating, and difficulty eating/feeling full when they were present for <1 year and occurred >12 days per month. In a logistic regression analysis, symptoms that were associated independently with cancer were pelvic/abdominal pain (P < .001), increased abdominal size/bloating (P<.001), and difficulty eating/feeling full (P = .010). A symptom index was considered positive if any of those 6 symptoms occurred >12 times per month but were present for <1 year. In the confirmatory sample, the index had a sensitivity of 56.7 for early‐stage disease and 79.5% for advanced‐stage disease. Specificity was 90% for women age >50 years and 86.7% for women age <50 years.CONCLUSIONS.Specific symptoms in conjunction with their frequency and duration were useful in identifying women with ovarian cancer. A symptom index may be useful for identifying women who are at risk. Cancer 2007. © 2006 American Cancer Society.
Antibody constructs in cancer therapy
Authors: Beckman Robert A , Weiner Louis M. , Davis Hugh M. 
Published: December 2006

AbstractWhereas over 85% of human cancers are solid tumors, of the 8 monoclonal antibodies (mAbs) currently approved for cancer therapy, 25% are directed at solid tumor surface antigens (Ags). This shortfall may be due to barriers to achieving adequate exposure in solid tumors. Advancements in tumor biology, protein engineering, and theoretical modeling of macromolecular transport are currently enabling identification of critical physical properties for antitumor Abs. It is now possible to structurally modify Abs or even replace full Abs with a plethora of Ab constructs. These constructs include Fab and Fab′2fragments, scFvs, multivalent scFvs (e.g., diabodies and tribodies), minibodies (e.g., scFv‐CH3 dimers), bispecific Abs, and camel variable functional heavy chain domains. The purpose of the article is to provide investigators with a conceptual framework for exploiting the recent scientific advancements. The focus is on 2 properties that govern tumor exposure: 1) physical properties that enable penetration of and retention by tumors, and 2) favorable plasma pharmacokinetics. It is demonstrated that manipulating molecular size, charge, valence, and binding affinity can optimize these properties. These manipulations hold the key to promoting tumor exposure and to ultimately creating successful Ab therapies for solid tumors. Cancer 2007. © 2006 American Cancer Society.
Unimolecular Reactivity of Uracil–Cu2+ Complexes in the Gas Phase
Authors: Lamsabhi Al Mokhtar , Alcamí Manuel , Mó Otilia , Yáñez Manuel , Tortajada Jeanine , Salpin Jean‐Yves 
Published: December 2006

AbstractThe gas‐phase interaction of copper(II) ions with uracil are studied by means of mass spectrometry and B3LYP/6‐311+G(2df,2p)//B3LYP/6‐31G(d) calculations. Positive‐ion electrospray spectra show that the reaction of uracil with copper(II) gives rise to singly charged species, whereby the [Cu(uracilH)]+ complex is the most intense ion in the spectra at low concentration. Mass spectrometry/mass spectrometry (MS/MS) experiments show that the loss of HNCO and NCO are the dominant fragmentation processes, accompanied by a minor loss of CO. A systematic study of the spectra obtained with different labeled species, namely, 2‐13C‐ (m/z 175), 2‐13C,1,3‐15N2‐ (m/z 177) and 3‐15N‐uracil (m/z 175), concludes unambiguously that both the loss of HNCO and NCO involve exclusively C2 and N3, whereas only C4 is involved in the loss of CO. Suitable mechanisms for these fragmentation processes are proposed through a theoretical survey of the corresponding potential energy surface. In these mechanisms, π complexes, which lie high in energy with respect to the global minimum, play a significant role in the loss of NCO; this explains why both products, HNCO and NCO involve the same atoms of the ring.
A transmission line model for metallic carbon nanotube interconnects
Authors: Maffucci A. , Miano G. , Villone F. 
Published: December 2006

AbstractA transmission line (TL) model describing the propagation of electric signals along metallic single wall carbon nanotube (CNT) interconnects is derived in a simple and self‐consistent way within the framework of the classical electrodynamics. The conduction electrons of metallic CNTs are modelled as an infinitesimally thin cylindrical layer of a compressible charged fluid with friction, moving in a uniform neutralizing background. The dynamic of the electron fluid is studied by means of the linearized hydrodynamic equations with the pressure assumed to be that of a degenerate spin‐½ ideal Fermi gas. Transport effects due to the electron inertia, quantum fluid pressure and electron scattering with the ion lattice significantly influence the propagation features of the TL. The simplicity and robustness of the fluid model make the derivation of the TL equations more straightforward than other derivations recently proposed in the literature and provide simple and clear definitions of the per unit length (p.u.l.) TL parameters. In particular, this approach has provided a new circuit model that can be used effectively in the analysis of networks composed of CNT transmission lines and lumped elements. The differences and similarities between the proposed model and those given in the literature are highlighted. Copyright © 2006 John Wiley & Sons, Ltd.
On the inclusion of geographic information systems (GIS) in global navigation satellite systems (GNSS)
Authors: Sadoun Balqies , Al‐Bayari Omar 
Published: December 2006

AbstractThe latest innovation of the global navigation satellite systems (GNSS) technologies plays an important role in improving the quality and safety of modern life. Most of the applications evolved from the integration between GNSS, geographical information systems (GIS) and wireless communications and networking (WCN) systems. The wide spread applications that are using these technologies include: the automatic vehicle location (AVL), tracking systems, navigation systems, pedestrian navigation systems, intelligent transportation systems, precise positioning, and emergency callers, among others. The location‐based services (LBS) are possible only by the combination of GNSS, GIS and WCN. The growing need for commercial LBS has forced cellular‐phone and network manufacturers to concentrate on positioning solutions, which are even more precise than the regulatory mandates for positioning of emergency callers and other user services and applications. In this paper, we will present a literature review of the GNSS, the three satellite systems GPS, GLONASS and Galileo, which are aimed to support GNSS services, and a comparison between them and their role in creating a GIS. Copyright © 2006 John Wiley & Sons, Ltd.
Linear and Rectangular Trinuclear Phthalocyanines
Authors: Makarov Sergey G. , Suvorova Olga N. , Litwinski Christian , Ermilov Eugeny A. , Röder Beate , Tsaryova Olga , Dülcks Thomas , Wöhrle Dieter 
Published: December 2006

AbstractIsomeric linear and rectangular trinuclear metal‐free andzinc(II) phthalocyanine complexes connected by common annulated benzene rings have been synthesized by the mixed cyclotetramerization of a 1,2,4,5‐tetracyanobenzene derivative and 4,5‐bis(2,6‐dimethylphenoxy)phthalonitrile. Their electronic‐absorption and fluorescence spectra have been studied in comparison with the corresponding mono‐ and dinuclear phthalocyanines. For the zinc complexes, the molecular orbitals and electronic spectra have been calculated semi‐empirically. The trinuclear phthalocyanines exhibit absorptions up to 940 nm with extinction coefficients up to about 700000 M–1 cm–1, which shows the extension of the π‐electron system.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Paramagnetic (Alkene)Rh and (Alkene)Ir Complexes: Metal or Ligand Radicals?
Authors: de Bruin Bas , Hetterscheid Dennis G. H. 
Published: December 2006

AbstractIn this review a detailed overview is given of the (electronic) structure and reactivity of open‐shell (paramagnetic) alkene rhodium and iridium complexes Mx(alkene) (M = Rh, Ir; x = 0, +II). In most cases these species are highly reactive, but some notable exceptions of stable species for which not much reactivity has been described are also included (section 2). Understanding the electronic structure of the reactive nitrogen‐ligand‐based [MII(por)(alkene)] and [MII(alkene)(N‐ligand)]2+ species (section 3) is complicated by a substantial spin distribution over the metal and the alkene ligand. This dual‐mode metallo‐radical and ligand radical behavior is reflected by their high and diverse reactivity. Metallo‐radical character is demonstrated by a variety of metal‐to‐radical coupling reactions with a series of other radicals, as well as metal‐based allylic hydrogen atom abstractions from MII(α‐alkene) species. On the other hand, (donor induced) ligand radical character is crucial in a variety of M–C and C–C radical coupling reactions, C–O bond formation by oxygenation of MII(alkene) species and alkene “insertions” into (por)M–H bonds. The review concludes with some speculations about possible roles of paramagnetic M(olefin) (M = Rh, Ir) species in catalytic olefin oxygenation and carbene transfer reactions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Experimental study of the formation of high‐resistivity zones at the gel/buffer interface in CE
Authors: Khozikov Vyacheslav , Kosobokova Olga , Citver Gregory , Tyshko George , Gavrilov Dmitri N. , Gudkov George , Gorfinkel Vera 
Published: December 2006

AbstractA novel, nondamaging method for experimental characterization of the formation and propagation of high‐resistivity zones in CE, based on the measurement of time‐dependent Joule heating on the outer capillary surface is proposed. The method detects propagation of resistive regions in capillaries in real time and allows the estimation of their velocity and resistance. The presented experimental data are in agreement with the results of the computer simulation as well as with previous data on the subject. The proposed method is useful for the development of new polymers as well as for the refinement and optimization of new CE protocols.
Screening of acetylcholinesterase inhibitors in natural extracts by CE with electrophoretically mediated microanalysis technique
Authors: Tang Zhong‐mei , Wang Zhao‐yan , Kang Jing‐wu 
Published: December 2006

AbstractAn electrophoretically mediated microanalysis (EMMA) method for screening acetylcholinesterase (AChE) inhibitors in natural extracts is described. In this method, solutions of AChE and the mixture of the substrate and the natural extract were successively injected into the capillary, and mixed electrophoretically by applying a voltage for a short time. Afterwards the voltage was reapplied to separate the product from the unreacted substrate and the natural extract. The measured peak area of the product at UV 230 nm represents the enzyme activity. Since the extract is mixed with the substrate, there is no need to separate the components before testing the inhibition. The inhibitory activity of the natural extract as a whole can be easily found if the peak area of the product is reduced. This makes the present method suitable for screening inhibitors in complex mixtures, such as natural extracts. Compared to the commonly used spectrometric method for screening of AChE inhibitors, the major advantage of the present method is the elimination of Ellman reagent, which is essential for the spectrometric method. This not only simplifies the experimental procedure but also minimizes false‐positive results. Moreover, it is an obvious advantage of combining the separation power with the on‐column enzyme assay for further investigating which compound(s) is/are responsible for the inhibition. The method was validated using a commercially available AChE inhibitor tacrine and a small chemical library containing four AChE inhibitors and 32 natural extracts. Inhibitors in natural extracts were identified with the present method.
CE detector based on light‐emitting diodes
Authors: Xiao Dan , Zhao Shulin , Yuan Hongyan , Yang Xiupei 
Published: December 2006

AbstractCE detectors based on light‐emitting diodes (LEDs) as light sources are receiving considerable attention due to their exceptionally high stability, high intensity, low cost, and a variety of wavelengths in the UV and visible spectrum. This article is a comprehensive review on CE methods using LED‐based detectors with absorbance and fluorescence detection, and several applications on the determination of riboflavin, bacteria, drug, and amino acids in biological samples are described.
Clinical and socio‐demographic characteristics of university students referred to an eating disorders service
Authors: Arcelus Jon , Button Eric 
Published: December 2006

AbstractThis study describes the socio‐demographic characteristics and eating disorders symptomatology of university students assessed by a specialised NHS eating disorders service in the UK over a 4‐year period. Information was gathered on past treatment history, source of referral, details of university and course of study, whether the patient was still open to the service or discharged, and if the patient had dropped out of contact from services. The study also describes the diagnosis of the assessed patients as well as the results of the Eating Disorders Inventory (EDI), Rosenberg Self‐Esteem Scale (RSES) and Revised Symptom Check List 90 (SCL‐90‐R) questionnaires. The study shows that the university students attending an eating disorder service often suffer from severe conditions, which are generally well‐established before they start their university studies. The study discuses the implication of those results in service delivery and future service development. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association.
Boundary element simulation of DC stray currents in oil industry due to cathodic protection interference
Authors: Metwally I. A. , Al‐Mandhari H. M. , Nadir Z. , Gastli A. 
Published: December 2006

AbstractThis paper presents a 3D theoretical simulation and analysis of DC stray current corrosion (SCC) in oil fields that could contribute to oil leak and finally oil deferment of electric submersible pump (ESP) systems. Application of the boundary element analysis system (BEASY) allowed cathodic protection (CP) interference to be assessed in terms of the normal current density, which is directly proportional to the corrosion rate, rather than using the qualitative approach of measuring the potential shift of the soil. Different real structures consisting of pipelines and/or well casings with different arrangements and interference conditions are simulated. The results reveal that the application of impressed current cathodic protection (ICCP) systems creates DC SCC on other nearby unprotected structures. This is an inherent potential problem with the application of such systems which dominates with decreasing soil conductivity, and/or increasing the anode current density and its proximity to the protected structures. On the contrary, SCC can be reduced by using multi‐groundbed anodes. Copyright © 2006 John Wiley & Sons, Ltd.
GFP chimeric models exhibited a biphasic pattern of mesenchymal cell invasion in tendon healing
Authors: Kajikawa Yoshiteru , Morihara Toru , Watanabe Nobuyoshi , Sakamoto Hirotaka , Matsuda Ken‐ichi , Kobayashi Masashi , Oshima Yasushi , Yoshida Atsuhiko , Kawata Mitsuhiro , Kubo Toshikazu 
Published: December 2006

AbstractThe healing of an injured musculoskeletal system requires an influx of mesenchymal cells that can differentiate into osteoblasts, fibroblasts, chondroblasts, and skeletal myoblasts. However, whether these mesenchymal cells arise from the circulation (bone marrow) or the injured tissues themselves has been controversial. To reveal the spatiotemporal characteristics of the reparative mesenchymal cells, we investigated the healing process after patellar tendon injury using two types of green fluorescent protein (GFP) chimeric rats; one expressing GFP in the circulating cells, and the other expressing it in the patellar tendon. We analyzed the behavior of GFP‐positive cells after experimental tendon injury in both chimeric rats to clarify the origin of reparative cells. At 24 h after the injury, the wound contained circulation‐derived cells but not tendon‐derived cells. Tendon‐derived cells first appeared in the wounded area at 3 days after the injury, and had significantly increased in number with time and had maintained a high level of proliferative activity until 7 days after the injury, whereas the circulation‐derived cells had decreased in number and had been replaced by the tendon‐derived cells. These findings suggest that circulation‐derived and tendon‐derived cells contribute to the healing of tendons in different periods as part of a biphasic process. J. Cell. Physiol. 210: 684–691, 2007. © 2006 Wiley‐Liss, Inc.