bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamics of essential oil biosynthesis in relation to inflorescence and glandular ontogeny in Salvia sclarea
Authors: Lattoo Surrinder K. , Dhar Rekha Sapru , Dhar Autar K. , Sharma Parduman R. , Agarwal Shri G. 
Published: April 2006

AbstractChanges in the essential oil concentration, composition and glandular morphology of Salvia sclarea L. were studied at different stages of inflorescence maturity. The chemical composition of oil was determined by GC–MS, NMR and the peak enrichment technique. The oil yield at bud stage on a fresh basis was minimum (0.08%), peaked at full bloom stage (0.18%) and was followed by sharp decline on maturation (0.07%). The main components of the oil were linalool (36.6–41.9%) and linalyl acetate (13.2–19.2%). The maximum percentage composition of various constituents was coincident with full bloom stage. β‐Humulene (6.4–8.9%), α‐cadinene (t–1.5%), β‐caryophyllene (t–1.4%), β‐caryophyllene oxide (0.4–1.4%) and sclareol (0.3–1.8%) present in the oil showed gradual increase in percentage over the different stages of maturity, with no significant turnover losses at maturation stage. Turnover of essential oil (61.1% loss) and monoterpenes (23.6% loss) occurred late in development at full maturity. Scanning electron microscopy (SEM) was used to follow the changes in the oil secretory glands over different temporal phases of maturation. The decline in oil concentration and monoterpene constituents compared very well with the observed deterioration and lyses of secretory glandular system. An abrupt fall in oil concentration apparently appears due to differential evaporation of the more volatile constituents, rather than as a dynamic balance between biosynthetic and catabolic processes.
A unique device for controlled electrospinning
Authors: Mitchell S.B. , Sanders J.E. 
Published: April 2006

AbstractThe purpose of this research was to develop a system for controlled electrospinning of fibro‐porous scaffolds for tissue engineering applications and to use this system to assess mesh architecture sensitivity to manufacturing parameters. The intent was to achieve scaffolds with well‐controlled fiber diameters and inter‐fiber spacing. To accomplish these objectives, a custom, closed‐loop controlled, electrospinning system was built. The system was unique in that it had a collection surface that was independent of the electrodes. The system allowed independent manipulation and analysis of a number of manufacturing parameters: distance between the electrodes, distance from the nozzle to the collection surface, applied voltage, temperature of the melt, collection surface dielectric strength, and collection surface area. Morphological analysis of fabricated meshes showed that all test parameters significantly affected fiber diameter and inter‐fiber spacing. Further, contrary to what is generally accepted in the electrospinning literature, voltage and temperature (inversely related to viscosity) were not the most significant parameters. Features of the collection surface, including dielectric strength and surface area, were more significant. This dominance is, in part, a reflection of the unique electrospinning system used. The collection surface, which was not connected to either of the electrodes, substantially altered the electric field between the electrodes. Using the developed controlled electrospinning system, thermoplastic polyurethane meshes with fiber diameters ranging from 5 to 18 μm with variability less than 1.8% were made; inter‐fiber spacing ranged from 4 to 90 μm with variability less than 20.2%. The system has potential use in biomedical applications where meshes with controlled fiber diameter and inter‐fiber spacing are of interest. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
A novel ultra high molecular weight polyethylene–hyaluronan microcomposite for use in total joint replacements. I. Synthesis and physical/chemical characterization
Authors: Zhang Min , King Richard , Hanes Mark , James Susan P. 
Published: April 2006

AbstractA novel microcomposite between ultra high molecular weight polyethylene (UHMWPE) and hyaluronan (HA) was developed to create a hydrophilic and lubricious UHMWPE surface for total joint replacement and other biomedical load‐bearing applications. Preforms with interconnected micropores were used as the UHMWPE starting material to form a microcomposite with HA, rather than starting with fully dense, bulk UHMWPE. HA was silylated first to increase its hydrophobicity and compatibility with UHMWPE. The silylated groups were removed through hydrolysis prior to final compression molding. A uniform and enzymatic degradation resistant HA film layer was produced on the microcomposite surface, which quickly hydrated in water, forming a lubricious surface film that was fully wetted by water drops during contact angle measurements. Presence of HA film on the composite surface was also demonstrated through X‐ray photoelectron spectroscopy analysis and Toluidine Blue O dye assay. The mechanical and tribological properties evaluation of the novel microcomposites are presented in Part II. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Interactions of B16F10 melanoma cells aggregated on a cellulose substrate
Authors: Hindié M. , Vayssade M. , Dufresne M. , Quéant S. , Warocquier‐Clérout R. , Legeay G. , Vigneron P. , Olivier V. , Duval J.‐L. , Nagel M.‐D. 
Published: April 2006

AbstractThere is evidence that the shape of cells and their contact with a matrix direct the growth and the differentiation of both normal and cancer cells. Cells in 3D culture resemble the in vivo situation more closely than do those in conventional 2D cultures. We have studied the interactions and functions of B16F10 mouse melanoma cells, which spread and grow well on tissue culture polystyrene (tPS), when they were made to aggregate on cellulose‐coated Petri dishes (CEL). This aggregation of melanoma cells on CEL was Ca2+ dependent and mediated by N‐cadherins. The levels of N‐cadherin and β‐catenin transcripts in cells cultured on CEL and tPS were similar, but those on CEL contained less β‐catenin protein. Immunoprecipitation and immunostaining showed that both N‐cadherins and β‐catenins were present at the membranes of cells on CEL. Cells proliferated significantly more slowly after 48 h on CEL and the cellulose coating caused most of them to arrest in G1. We also compared the melanin contents and tyrosinase activity of cells on CEL and controls grown on tPS. Melanogenesis was induced in cells aggregated on CEL. A cellulose substrate thus appears to be an outstanding tool for studying cell–cell interactions and cell functions in 3D cultures. © 2006 Wiley‐Liss, Inc.
The polarizable continuum model (PCM) interfaced with the fragment molecular orbital method (FMO)
Authors: Fedorov Dmitri G. , Kitaura Kazuo , Li Hui , Jensen Jan H. , Gordon Mark S. 
Published: April 2006

AbstractThe polarizable continuum model (PCM) for the description of solvent effects is combined with the fragment molecular orbital (FMO) method at several levels of theory, using a many‐body expansion of the electron density and the corresponding electrostatic potential, thereby determining solute (FMO)–solvent (PCM) interactions. The resulting method, denoted FMO/PCM, is applied to a set of model systems, including α‐helices and β‐strands of alanine consisting of 10, 20, and 40 residues and their mutants to charged arginine and glutamate residues. The FMO/PCM error in reproducing the PCM solvation energy for a full system is found to be below 1 kcal/mol in all cases if a two‐body expansion of the electron density is used in the PCM potential calculation and two residues are assigned to each fragment. The scaling of the FMO/PCM method is demonstrated to be nearly linear at all levels for polyalanine systems. A study of the relative stabilities of α‐helices and β‐strands is performed, and the magnitude of the contributing factors is determined. The method is applied to three proteins consisting of 20, 129, and 245 residues, and the solvation energy and computational efficiency are discussed. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 976–985, 2006
Royal crown‐shaped electride Li3‐N3‐Be containing two superatoms: New knowledge on aromaticity
Authors: Li Zhi‐Ru , Wang Fang‐Fang , Wu Di , Li Ying , Chen Wei , Sun Xiao‐Ying , Gu Feng Long , Aoki Yuriko 
Published: April 2006

AbstractThe structure and aromaticity of a royal crown‐shaped molecule Li3‐N3‐Be are studied at the CCSD(T)/aug‐cc‐pVDZ level. This molecule is a charge‐separated system and can be denoted as Li32+N33−Be+. It is found that the Li32+ring exhibits aromaticity mainly because the Li32+ring can share the π‐electron with the N3−3ring. The 4n+2 electron counter rule can be satisfied for the Li32+subunit if the shared π valence electron of N33−subunit is also taken into account. This new knowledge on aromaticity of a ring from the interactions between subunits is revealed first time in this paper. Li3‐N3‐Be can be also regarded as a molecule containing two superatoms (Li3and N3), which may be named as a “superomolecule.” Li3‐N3‐Be is a new metal–nonmetal–metal type sandwich complex. The N33−trianion in the middle repulses the electron clouds of the two metal subunits (mainly to the Li3superatom) to generate an excess electron, and thus Li3‐N3‐Be is also an electride. This phenomenon of the repulsion results in: (a) the HOMO energy level increased, (b) the electron cloud in HOMO distended, (c) the area of the negative NICS value extended, and (d) the VIE value lowered. So the superomolecule Li3‐N3‐Be is not only a new metal–nonmetal–metal type sandwich complex but also a new type electride, which comes from the interaction between the alkali superatom (Li3) and the nonmetal superatom (N3). © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 986–993, 2006
Selection and combination of machine learning classifiers for prediction of linear B‐cell epitopes on proteins
Authors: Söllner Johannes 
Published: April 2006

AbstractRecently, new machine learning classifiers for the prediction of linear B‐cell epitopes were presented. Here we show the application of Receiver Operator Characteristics (ROC) convex hulls to select optimal classifiers as well as possibilities to improve the post test probability (PTP) to meet real world requirements such as high throughput epitope screening of whole proteomes. The major finding is that ROC convex hulls present an easy to use way to rank classifiers based on their prediction conservativity as well as to select candidates for ensemble classifiers when validating against the antigenicity profile of 10 HIV‐1 proteins. We also show that linear models are at least equally efficient to model the available data when compared to multi‐layer feed‐forward neural networks. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of coverage density and structure of chemically bonded silica stationary phases on the separation of compounds with various properties
Authors: Buszewski Bogusław , Krupczyńska Katarzyna , Rychlicki Gerhard , Łobiński Ryszard 
Published: April 2006

AbstractThe chemical character, geometry, and architecture of chemically formed surface layers determine interactions between stationary phase, analyte, and mobile phase, and therefore the retention mechanisms (partitioning, adsorption, ion exchange, steric exclusion) of separated analytes. These interactions also depend on the structure and chemical character of the solutes and the composition of the mobile phase. High‐molecular‐weight fullerenes (C60 and C70) and water‐soluble selenium‐containing peptides (833 and 2607 Da) were used for the evaluation of laboratory‐prepared octadecyl stationary phases with high and low coverage density before and after end‐capping. The aim of this work was to study differences in surface coverage density and homogeneity and conformational changes of chemically bonded moieties and the influence of these parameters on the separation of mixtures of selenopeptides and fullerenes with significantly different molecular masses. A topographical model of the chemically modified stationary surface is presented.
Nonlinear degenerate parabolic equations for Baouendi–Grushin operators
Authors: Kombe Ismail 
Published: April 2006

AbstractIn this paper, we shall investigate the nonexistence of positive solutions for the following nonlinear parabolic partial differential equations:
equation image
and
equation image
Here, Ω is a Carnot–Carathéodory metric ball in RN and V ∈ L 1loc(Ω). The critical exponents m * and p * are found, and the nonexistence results are proved for m * ≤ m < 1 and p * ≤ p < 2. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the metrical properties of the configuration space
Authors: Kondratiev Yu. G. , Kutoviy O. V. 
Published: April 2006

AbstractWe study some topological and metrical properties of configuration spaces. In particular, we introduce a family of metrics on the configuration space Γ, which makes it a Polish space. Compact functions on Γ are also considered. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of DNA‐bound advanced glycation end‐products by immunoaffinity chromatography coupled to HPLC‐diode array detection
Authors: Schneider Marc , Georgescu Adriana , Bidmon Clemens , Tutsch Martin , Fleischmann Erwin H. , Popov Doina , Pischetsrieder Monika 
Published: April 2006

AbstractSugars and sugar degradation products are formed during food processing, but also endogenously in vivo. In vitro, nucleosides and DNA react readily with these carbonyl compounds during the formation of the two diastereomers of N2‐carboxyethyl‐2′‐deoxyguanosine (CEdGA,B), leading to a loss of DNA integrity. Only little is known about DNA glycation in vivo and about the influence of nutrition on CEdG formation. In this study, we developed a sensitive method to analyze DNA glycation by HPLC. For this purpose, immunoaffinity chromatography (IAC) using a polyclonal antibody against N2‐carboxyethylguanine (CEguanine) was coupled to HPLC‐DAD. In some samples, peak identity was confirmed by LC‐MS/MS. The recovery of CEguanine from the IAC columns was 52.5% ± 3.6 (n = 4). Thus, it was possible for the first time to detect CEdGA,B, N2‐carboxyethylguanosine (CEGA,B), and CEguanine in 11 human urine samples. However, due to imprecision of IAC, valid quantification of the adducts could not be achieved. Furthermore, CEdG was also detected in the DNA of cultured human smooth muscle cells (SMCs) and bovine aorta endothelium cells (BAECs). In BAECs, CEdGA,B were found by HPLC‐DAD and LC‐MS/MS after immunoaffinity purification, whereas in SMCs DNA‐advanced glycation end‐products were only detected with the more sensitive LC‐MS/MS method.
Quantitative analysis of allele imbalance supports atypical ductal hyperplasia lesions as direct breast cancer precursors
Authors: Larson PS , de las Morenas A , Cerda SR , Bennett SR , Cupples LA , Rosenberg CL 
Published: April 2006

AbstractIt remains unclear whether hyperplastic breast lesions, especially with atypia, are cancer precursors or markers of increased cancer risk. Quantified comparisons of genomic alterations in coexisting lesions could address this question. Therefore, we examined allele imbalance (AI), also known as loss of heterozygosity (LOH), at 20 microsatellite markers on nine chromosome arms, in DNA from 106 samples microdissected from 17 randomly selected cancer‐containing breast specimens: 13 simple (DH) and 45 atypical ductal hyperplastic (ADH) lesions, 30 in situ (DCIS) and 18 invasive ductal carcinomas (IDC). Data were analysed using regression models and generalized estimating equations. We found that AI increased as histology became more aberrant and varied with histology across the chromosome arms (p <0.0001). ADH had more AIs on 1q (p = 0.03) and 16q (p = 0.02) and fewer AIs on 17p (p = 0.06) and 17q (p <0.0001) than on other arms. In cancers, AIs remained high on 1q and 16q, and became frequent on 17p and 17q. Concordance between AIs in ADHs and cancers exceeded the 50% expected if the lesions were separate clones in 16/20 (80%) ADHs (p = 0.05), from 9/11 (82%) cases (p = 0.03), and involved 41/51 (80%) evaluable markers (p = 0.05). The occurrence of any AI in ADH predicted greater AI (p = 0.009) and possibly lower grade (p = 0.05) in coexisting cancers. Nevertheless, ADHs were not genetically identical to cancers or to each other. We found AIs discordant between ADHs and cancers (always on 1q and 16q), AIs unique to ADH (usually on 11q) and some genetic heterogeneity among coexisting ADHs. We conclude that ADH lesions are genetically advanced, with frequent alterations on 1q and 16q, and are often direct cancer precursors. Their global genetic characteristics predict features of cancers in the same breast. Nevertheless, the genetic heterogeneity detected suggests that hyperplasias and cancers may arise on a field at generalized increased cancer risk. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Body composition and bone mass in survivors of childhood cancer
Authors: Muszynska‐Roslan Katarzyna , Konstantynowicz Jerzy , Krawczuk‐Rybak Maryna , Protas Piotr 
Published: April 2006

AbstractBackgroundThe number of survivors of childhood cancer has increased. Several studies in children and adults have shown relationships between lean mass (LM), fat mass (FM), and bone mineral content (BMC). The objective of the study was to examine the association between body composition and bone mass in young survivors of childhood cancer.MethodsSixty‐eight postpubertal participants (31 females and 37 males) aged between 15.5 and 27 years who were at least 5 years after completion of treatment for leukemia (n = 30), lymphoma (n = 28), or solid tumors (n = 10) were studied. Anthropometry was performed and dual energy X‐ray absorptiometry (DXA) was used to assess BMC in the total body (T) and lumbar spine (S), FM, and LM.ResultsThere were no observed differences in age or time for cessation of treatment. Body mass index (BMI) was a strong determinant of bone mass in both sexes. TBMC correlated positively with LM (males r = 0.9 and females r = 0.76; P < 0.0001, respectively) and with FM (r = 0.54; P < 0.01 in males and r = 0.8; P < 0.00001 in females). SBMC correlated with LM in both sexes (in males r = 0.77 and in females r = 0.64; P < 0.0001, respectively) but only in females, SBMC also correlated positively with FM (r = 44 P = 0.03). There were no differences between patients who received radiation and those who did not.ConclusionsThe associations between bone mass and body composition differ by sex and skeletal site, however, they are similar in survivors of childhood cancer and compared to healthy individuals during growth. Further prospective research is needed in cancer survivors to determine the long‐term effect of anti‐cancer therapy on body composition and bone mass. Pediatr Blood Cancer 2007;48:200–204. © 2006 Wiley‐Liss, Inc.
Characterization and electrical properties of polypyrrole/multiwalled carbon nanotube composites synthesized by in situ chemical oxidative polymerization
Authors: Wu Tzong‐Ming , Lin Shih‐Hsiang 
Published: April 2006

AbstractThis study describes the preparation of polypyrrole (PPy)/multiwalled carbon nanotube (MWNT) composites by in situ chemical oxidative polymerization. Various ratios of MWNTs, which served as hard templates, were first dispersed in aqueous solutions with the surfactant cetyltrimethylammonium bromide to form micelle/MWNT templates and overcome the difficulty of MWNTs dispersing into insoluble solutions of pyrrole monomer, and PPy was then synthesized via in situ chemical oxidative polymerization on the surface of the templates. Raman spectroscopy, Fourier transform infrared (FTIR), field‐emission scanning electron microscopy (FESEM), and high‐resolution transmission electron microscopy (HRTEM) were used to characterize the structure and morphology of the fabricated composites. Structural analysis using FESEM and HRTEM showed that the PPy/MWNT composites were core (MWNT)–shell (PPy) tubular structures. Raman and FTIR spectra of the composites were almost identical to those of PPy, supporting the idea that MWNTs served as the core in the formation of a coaxial nanostructure for the composites. The conductivities of these PPy/MWNT composites were about 150% higher than those of PPy without MWNTs. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1413–1418, 2006
Electrospinning process using field‐controllable electrodes
Authors: Kim Geun Hyung 
Published: April 2006

AbstractFor the production of uniaxially oriented nanofibers and a three‐dimensional, biodegradable scaffold consisting of nanosized fibers, an electrospinning process was modified with a cylindrical auxiliary electrode that was connected to a spinning nozzle to stabilize the initially spun solution and a parallel‐plate electrode as a collector generating an alternating‐current electric field for collecting spun jets. With the complex electric field in the electrospinning process, biodegradable poly(ε‐caprolactone) nanofibers were stacked on a thin, dielectric substrate covering the electrode according to a predetermined design. The degree of orientation of spun nanofibers to the field direction of a target electrode was highly dependent on the applied frequency and field strength of the target electrode. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1426–1433, 2006
Synthesis and herbicidal activity of novel α,α,α‐trifluoro‐m‐tolyl pyridazinone derivatives
Authors: Xu Han , Zou Xiao‐Mao , Zhu You‐Quan , Liu Bin , Tao Han‐Lin , Hu Xu‐Hong , Song Hai‐Bin , Hu Fang‐Zhong , Wang Yong , Yang Hua‐Zheng 
Published: April 2006

AbstractA series of novel α,α,α‐trifluoro‐m‐tolyl pyridazinone derivatives was synthesised. Herbicidal activities of the two intermediate compounds and 15 pyridazinone derivatives were evaluated through barnyardgrass and rape cup tests and Spirodela polyrrhiza (L.) Schleiden tests. Selected compounds were also evaluated under greenhouse conditions. Bleaching activities were observed at 10 µg ml−1 and some compounds exhibited herbicidal activities at a rate of 300 g ha−1. The relationship between crystal structures and herbicidal activities is discussed through a comparison of two compounds (5a and 5f). Copyright © 2006 Society of Chemical Industry
Application of a Receptor Pruning Methodology to the Enoyl‐ACP Reductase from Escherichia coli (FabI)
Authors: Pasqualoto Kerly F. M. , Ferreira Márcia M. C. 
Published: April 2006

AbstractReceptor pruning is an approach for achieving reasonable conformational ensemble profile in terms of time and computational resources. The purpose of this study is to reduce the size of a model structure of enoyl‐acp reductase (ENR) from E. coli, FabI, to allow ligand‐receptor molecular dynamic (MD) simulations to be computationally economical yet still provide meaningful binding thermodynamic data. Three reduced‐size models of FabI were created by pruning away all residues greater than 12, 10 and 8 Å radius. The largest ligand was docked in the active site to define the largest required receptor model. Energy minimization and MD simulations were carried out using the MOLSIM 3.2 program. The lowest energy structure for each of receptor models from MD calculation was compared by root mean square (RMS) fit to the equivalent portion of the crystal structure of FabI. A scale‐down 12 Å receptor model of the enzyme FabI maintains the structural integrity of the composite parent crystal structure. The perspectives include the structure‐based design of new antituberculosis agents regarding the similarity in the active site of two ENRs, FabI and InhA (M. tuberculosis).