bluuebunny/crossref_metadata_2025_split huggingface dataset:
DFT study of the biphenylene–NO complexes formed in nitration mechanism
Authors: Roohi Hossein 
Published: July 2008

AbstractThe most probable complexes formed in biphenylene (BP) nitration pathway have been investigated at B3LYP/6‐31+G(d,p) level of theory in the gas phase. To obtain more accurate energies, single point calculations were carried out at B3LYP/6‐31++G(2d,2p), B3PW91/6‐31+G(d,p), and B3PW91/6‐31++G(2d,2p) levels using B3LYP/6‐31+G(d,p) optimized geometry. The six intermediates and one transition state were found before the subsequent formation of the arenium ion on the potential energy surface of the electrophilic nitration of BP. It was also shown that the positionβin the BP is much more susceptible to electrophilic attack than the competing positionα. The Natural Bond Orbital (NBO), Charges from Electrostatic Potentials using a Grid based method (CHelpG), and Merz–Singh–Kollman (MK) charges and s‐characters of atoms involved in the reaction mechanism were calculated. Inspection of charges in the moieties indicates that the positive charge in all complexes is chiefly located on the BP, which means that theNO2moiety received the electron from the BP. To investigate the nature of BP–${\rm NO}_{2}^{\rm + } {\rm }$interaction in the fiveπ‐complexes, atoms in molecules (AIM) analysis was performed. The AIM results suggested that the BP–${\rm NO}_{2}^{+ } {\rm }$interactions have an electrostatic characteristic. In addition, high electrostatic interactions were predicted inπ‐complexes in which one of the oxygen atoms of${\rm NO}_{2}^{ + } {\rm }$interacts with the BP. Nucleus‐independent chemical shift (NICS) methodology has been applied to study the change of antiaromaticity in four‐membered ring of BP upon complexation with${\rm NO}_{2}^{+ } {\rm }$. The results based on NICS calculations show that antiaromaticity of four‐membered ring decreases upon complexation. Copyright © 2008 John Wiley & Sons, Ltd.
Improved Adhesion of RF Plasma Treated Rubbers by Isocyanate Incorporation to Polyurethane Adhesive
Authors: Ortíz‐Magán Ana B. , Pastor‐Blas M. Mercedes 
Published: July 2008

AbstractThe effect of addition of isocyanate to a polyurethane adhesive has been investigated. Polyurethane adhesive was used for bonding a thermoplastic (TR) and a vulcanized (VR) synthetic butadiene‐styrene rubber. CO2 plasma treatment has oxidized the rubber surfaces, increasing surface energy (wettability), roughness, and favoring mechanical interlocking of rubber surface with the adhesive. Adhesion of TR rubber towards PU polyurethane adhesive was enhanced by these mechanisms; however, migration of antiadherent low molecular weight moieties to the VR rubber/polyurethane adhesive interface produced a lack of adhesion. In this case, it was necessary to produce the crosslinking with isocyanate of the polyurethane adhesive and of the VR rubber surface.magnified image
Chemistry of Plasma‐Polymerized Vinyltriethoxysilane Controlled by Deposition Conditions
Authors: Cech Vladimir , Zemek Josef , Perina Vratislav 
Published: July 2008

AbstractPlasma‐polymerized thin films of vinyltriethoxysilane were deposited on IR‐transparent silicon wafers using plasma‐enhanced chemical vapor deposition at a wide range of RF pulsed power (0.05–25 W). The deposited films were analyzed by various spectroscopic techniques (RBS, ERDA, XPS, and FTIR) in order to compare their chemical structure and elemental composition, which were correlated with plasma products monitored by mass spectroscopy. Thin polymer films deposited at 0.05 W were SiO‐rich (55 at.‐%), while those prepared at 25 W were dominated by carbon (66 at.‐%). The organic/inorganic character (C/Si ratio) of plasma polymer varied widely, from 2.5 to 7.3 with enhanced power. The chemical structure of the polymer network and side groups was also controlled by the effective power. Chemical analyses enabled us to gain an idea of the chemical structure of the films.magnified image
Socioeconomic factors and asthma control in children
Authors: Cope Shannon F. , Ungar Wendy J. , Glazier Richard H. 
Published: July 2008

AbstractObjectivesThe objective of this study was to evaluate the association between socioeconomic factors and asthma control in children, as defined by the Canadian Pediatric Asthma Consensus Guidelines.Patients and MethodsCross‐sectional data from a completed study of 879 asthmatic children between the ages of 1 and 18 residing in the Greater Toronto Area were used. The database included data on demographics, health status, asthma control, and health‐related quality of life. Stepwise forward modeling multiple regression was used to investigate the impact of socioeconomic status on asthma control, based on six control parameters from the 2003 Canadian Pediatric Asthma Consensus Guidelines.ResultsOnly 11% of patients met the requirements for acceptable control, while 20% had intermediate control, and 69% had unacceptable asthma control. Children from families in lower income adequacy levels had poorer control.ConclusionsDisparities in asthma control between children from families of different socio‐economic strata persist, even with adjustment for utilization of primary care services and use of controller medications. Pediatr Pulmonol. 2008; 43:745–752. © 2008 Wiley‐Liss, Inc.
Effect of secondhand cigarette smoke, RSV bronchiolitis and parental asthma on urinary cysteinyl LTE4
Authors: Kott Kayleen S. , Salt Bryn H. , McDonald Ruth J. , Jhawar Sanjay , Bric John M. , Joad Jesse P. 
Published: July 2008

AbstractCysteinyl leukotrienes promote airway inflammation, bronchoconstriction and mucus hypersecretion. Cigarette smoking and respiratory syncytial virus (RSV) bronchiolitis are known to increase urinary cysteinyl leukotriene E4 (uLTE4), the end product of the cysteinyl leukotriene biosynthetic pathway. We tested the following hypotheses: (1) Secondhand smoke (SHS) exposure increases uLTE4 in well infants and in those hospitalized for RSV bronchiolitis; (2) Length of hospital stay for those with RSV bronchiolitis correlates with uLTE4; and (3) Infants with parent(s) with asthma will have higher uLTE4. Parental asthma for infants hospitalized with RSV bronchiolitis (n = 79) and Well babies (n = 31) was determined by questionnaire. Urine was analyzed for LTE4, cotinine, and creatinine. SHS exposure was determined by cotinine to creatinine ratio. Chi square, or t‐tests were used to determine significant differences between two groups. A three‐way analysis of variance compared the effects of SHS exposure and parental asthma on uLTE4 in Well versus RSV babies. Independent variables predicting length of hospital stay were determined by stepwise multiple regression. High SHS exposure and RSV significantly increased uLTE4. The SHS induced increase in uLTE4 was seen in infants with no parental asthma but not in those with parental asthma. Length of hospital stay positively correlated with uLTE4. We concluded that SHS exposure may increase the severity of bronchiolitis in RSV‐infected infants by enhancing production of cysLTs in infants with no parental asthma. Pediatr Pulmonol. 2008; 43:760–766. © 2008 Wiley‐Liss, Inc.
Children with new tracheostomies: Planning for family education and common impediments to discharge
Authors: Graf Jeanine M. , Montagnino Barbara A. , Hueckel Remí , McPherson Mona L. 
Published: July 2008

AbstractObjectivesTo describe an educational program and timeline for the discharge of children with a new tracheostomy and identify common impediments to the education and discharge process.MethodsRetrospective pilot case series of 70 children and adolescents undergoing tracheostomy placement over a 24‐month period in a large urban academic pediatric hospital.ResultsEleven healthcare providers with expertise with technology dependent children identified the eight most common impediments to education and discharge for children with new tracheostomies. Length of stay, impediments to both education and discharge, and medical equipment needed at the time of discharge were extracted from hospital records. Caregivers of children with new tracheostomies needed a median of 14 days (range 5–110 days) to successfully complete a tracheostomy education program. Discharge occurred a median of 6.5 days (range 0–71 days) after education was completed. Common impediments to completing the education program included social issues (e.g., lack of sibling childcare), inter‐current illness of the patient and/or language barriers. Impediments to discharge included patient's inter‐current illnesses, social issues (e.g., lack of running water) and unavailability of home nursing. Our cohort of patients had a total median length of stay (LOS) of 46 days. At discharge, 55% of children required two or more medical devices (in addition to their tracheostomy) and 61% had some level of dependency on positive pressure ventilation.ConclusionsPediatric patients with a new tracheostomy undergo lengthy initial hospitalizations and have complex educational and discharge needs. Multiple factors (both medical and social) can impede the child's transition to the outpatient setting. A structured education and discharge program may result in a shorter LOS for children with new tracheostomies. Impediments to family education and discharge should be anticipated. Pediatr Pulmonol. 2008; 43:788–794. © 2008 Wiley‐Liss, Inc.
Effects of betamethasone on peripheral arterial development in term fetal rabbit
Authors: Roubliova Xenia I. , Lewi Paul J. , Vaast Pascal , Jani Jacques C. , Verbeken Eric K. , Tibboel Dick , Deprest Jan A. 
Published: July 2008

AbstractGlucocorticoids are given antenatally to promote pulmonary epithelial maturation and prevent respiratory distress syndrome in premature newborns. In contrast to airway changes, effects on vessels are less documented. We hypothesized that antenatal betamethasone (BM) administration promotes vascular development. Does received either a course of BM = 0.05 mg/kg/day (18 does, 70 fetuses), BM = 0.1 mg/kg/day (20 does, 75 fetuses), or saline (11 does, 92 fetuses) starting on d25, 26 (canalicular stage), d27, d28 (saccular stage), and d29 (alveolar stage) of gestation. In total 236 fetuses from 49 does were examined at term (d31) in terms of vascular development. Lung specimens were weighed and formalin fixed for morphometry. We determined differences in fetal body, liver and lung weight, proportionate medial thickness, muscularization of intra‐acinar vessels, number of vessels under 100 µm, as well as immunoreactivity to Flk‐1 in vascular smooth muscle and endothelial cells. A dose‐dependent reduction in neonatal body and organ weight was observed in fetuses exposed to BM at d25. In contrast, term liver weight increased after late administration of BM (d28, 29). There was a dose‐ and time‐dependent thinning of the pulmonary arterial media, which coincided with a decreased proportion of intra‐ and pre‐acinar muscularized arteries (ED ≤ 60 µm) and increased microvascularization (ED ≤ 30), as well as increased endothelial immunoreactivity for Flk‐1. Analyzing our data using a purpose designed geometrical model, the results suggest that maternal administration of BM promotes changes in vascular morphology, which may be compatible with remodeling and vessel formation. Pediatr Pulmonol. 2008; 43:795–805. © 2008 Wiley‐Liss, Inc.
Can bronchodilator response predict bronchial response to methacholine in preschool coughers?
Authors: Beydon Nicole , M'Buila Célestin , Peiffer Claudine , Bernard Agnès , Zaccaria Isabelle , Denjean André 
Published: July 2008

AbstractThe aim of the present study was to determine the relationship between bronchodilator response, assessed by interrupter resistance (Rint), and bronchial reactivity in preschool children with chronic cough. Thirty‐eight children coughers (median age 5.0 years, range 2.8–6.4) were tested. Bronchodilator response was recorded within 4 months before methacholine challenge. Response to the latter was assessed using transcutaneous partial pressure of oxygen and Rint. Children were considered responders if a 20% fall in transcutaneous partial pressure of oxygen occurred during the bronchial challenge. Bronchodilator response was not different between responders (n = 24) and nonresponders (n = 14) [median (range) −0.11 (−0.44–0.09) vs. −0.08 (−0.21–0.10) kPa L−1 sec; respectively]. However, none of the nonresponders had a bronchodilator response larger than −0.21 kPa L−1 sec, this cutoff had a 100% positive and a 44% negative predictive value to predict a positive methacholine challenge. The relationship between bronchodilator response and bronchial methacholine responsiveness reached the limit of significance (P = 0.048). Furthermore, the magnitude of the bronchodilator response was correlated to the level of methacholine‐induced level of bronchoconstriction (P = 0.01), and to the postchallenge bronchodilation (P = 0.04), all values expressed as % predicted. Moreover, the postbronchodilator Rint value obtained with preceding methacholine challenge was lower than the postbronchodilator value without preceding methacholine challenge in 71.4% (10/14) of the nonresponders and in only 33.3% (8/24) of the responders. Conclusions in preschool coughers bronchodilator response, assessed by the interrupter technique, was correlated to the bronchial responsiveness to methacholine. Non responders had a bronchodilator response not larger than −0.21 kPa L−1 sec. Pediatr Pulmonol. 2008; 43:815–821. © 2008 Wiley‐Liss, Inc.
Depletion of intracellular zinc increases expression of tumorigenic cytokines VEGF, IL‐6 and IL‐8 in prostate cancer cells via NF‐κB‐dependent pathway
Authors: Golovine Konstantin , Uzzo Robert G. , Makhov Peter , Crispen Paul L. , Kunkle David , Kolenko Vladimir M. 
Published: July 2008

AbstractBACKGROUNDZinc accumulation diminishes early in the course of prostate malignancy and continues to decline during progression toward hormone‐independent growth. In contrast, constitutive levels of NF‐κB activity increase during progression of prostate cells toward greater tumorigenic potential. We have reported previously that physiological levels of zinc suppress NF‐κB activity in prostate cancer cells and reduce expression of pro‐angiogenic and pro‐metastatic cytokines VEGF, IL‐6, IL‐8, and MMP‐9 associated with negative prognostic features in prostate cancer.METHODSIntracellular zinc levels were examined by atomic absorption spectroscopy. NF‐κB activity was examined by TransAm and Luciferase reporter assays, and Western blot analysis of p50 nuclear translocation. VEGF, IL‐6 and IL‐8 levels were assessed by ELISA.RESULTSSelective zinc deficiency induced by the membrane‐permeable zinc chelator N,N,N′,N′‐tetrakis(2‐pyridylmethyl)‐ethylenediamine (TPEN) increases activation of NF‐κB and up‐regulates expression of the NF‐κB controlled pro‐angiogenic and pro‐metastatic cytokines VEGF, IL‐6 and IL‐8 in androgen‐independent PC‐3 and DU‐145 prostate cancer cells. Pre‐incubation with IκBα dominant mutant adenovirus efficiently blocks expression of these cytokines in zinc deficient cells indicating that the observed effects are NF‐κB dependent.CONCLUSIONSOur findings suggest that zinc deficiency may contribute to the tumor progression via augmented expression of the NF‐κB‐dependent pro‐tumorigenic cytokines. Prostate 68: 1443–1449, 2008. © 2008 Wiley‐Liss, Inc.
Human FEZ1 has characteristics of a natively unfolded protein and dimerizes in solution
Authors: Lanza Daniel C. F. , Silva Julio C. , Assmann Eliana M. , Quaresma Alexandre J. C. , Bressan Gustavo C. , Torriani Iris L. , Kobarg Jörg 
Published: July 2008

AbstractThe fasciculation and elongation protein Zeta 1 (FEZ1) is the mammalian orthologue of the Caenorhabditis elegans protein UNC‐76, which is necessary for axon growth. Human FEZ1 interacts with Protein Kinase C (PKC) and several regulatory proteins involved in functions ranging from microtubule associated transport to transcriptional regulation. Theoretical prediction, circular dichroism, fluorescence spectroscopy, and limited proteolysis of recombinant FEZ1 suggest that it contains disordered regions, especially in its N‐terminal region, and that it may belong to the group of natively unfolded proteins. Small angle X‐ray scattering experiments indicated a mainly disordered conformation, proved that FEZ1 is a dimer of elongated shape and provided overall dimensional parameters for the protein. In vitro pull down experiments confirmed these results and demonstrated that dimerization involves the N‐terminus. Ab‐initio 3D low resolution models of the full‐length conformation of the dimeric constructs 6xHis‐FEZ1(1‐392) and 6xHis‐FEZ1(1‐227) were obtained. Furthermore, we performed in vitro phosphorylation assays of FEZ1 with PKC. The phosphorylation occurred mainly in its C‐terminal region, and does not cause any significant conformational changes, but nonetheless inhibited its interaction with the FEZ1 interacting domain of the protein CLASP2 in vitro. The C terminus of FEZ1 has been reported to bind to several interacting proteins. This suggests that FEZ1 binding and transport function of interacting proteins may be subject to regulation by phosphorylation. Proteins 2009. © 2008 Wiley‐Liss, Inc.
A novel binding pocket of cyclin‐dependent kinase 2
Authors: Chen Hao , Van Duyne Rachel , Zhang Naigong , Kashanchi Fatah , Zeng Chen 
Published: July 2008

AbstractThe cyclin‐dependent kinase 2 (cdk2) is a serine/threonine protein kinase that plays a key role in the cell cycle control system of all eukaryotic organisms. It has been a much studied drug target for potential anticancer therapy. Most cdk2 inhibitors in clinical development target almost exclusively the catalytic ATP‐binding pocket of cdk2. However, several five amino‐acid peptide inhibitors that are directed towards a noncatalytic binding pocket of cdk2 are reported here. Upon binding to this new pocket located at the cdk2 and cyclin interface, these peptide inhibitors are found to disrupt the cdk2/cyclin E complex partially and diminish its kinase activity in vitro. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Solution structure of the GUCT domain from human RNA helicase II/Guβ reveals the RRM fold, but implausible RNA interactions
Authors: Ohnishi Satoshi , Pääkkönen Kimmo , Koshiba Seizo , Tochio Naoya , Sato Manami , Kobayashi Naohiro , Harada Takushi , Watanabe Satoru , Muto Yutaka , Güntert Peter , Tanaka Akiko , Kigawa Takanori , Yokoyama Shigeyuki 
Published: July 2008

AbstractHuman RNA helicase II/Guα (RH‐II/Guα) and RNA helicase II/Guβ (RH‐II/Guβ) are paralogues that share the same domain structure, consisting of the DEAD box helicase domain (DEAD), the helicase conserved C‐terminal domain (helicase_C), and the GUCT domain. The N‐terminal regions of the RH‐II/Gu proteins, including the DEAD domain and the helicase_C domain, unwind double‐stranded RNAs. The C‐terminal tail of RH‐II/Guα, which follows the GUCT domain, folds a single RNA strand, while that of RH‐II/Guβ does not, and the GUCT domain is not essential for either the RNA helicase or foldase activity. Thus, little is known about the GUCT domain. In this study, we have determined the solution structure of the RH‐II/Guβ GUCT domain. Structural calculations using NOE‐based distance restraints and residual dipolar coupling‐based angular restraints yielded a well‐defined structure with β‐α‐α‐β‐β‐α‐β topology in the region for K585‐A659, while the Pfam HMM algorithm defined the GUCT domain as G571‐E666. This structure‐based domain boundary revealed false positives in the sequence homologue search using the HMM definition. A structural homology search revealed that the GUCT domain has the RRM fold, which is typically found in RNA‐interacting proteins. However, it lacks the surface‐exposed aromatic residues and basic residues on the β‐sheet that are important for the RNA recognition in the canonical RRM domains. In addition, the overall surface of the GUCT domain is fairly acidic, and thus the GUCT domain is unlikely to interact with RNA molecules. Instead, it may interact with proteins via its hydrophobic surface around the surface‐exposed tryptophan. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Isopeptide method: development of S‐acyl isopeptide method for the synthesis of difficult sequence‐containing peptides
Authors: Yoshiya Taku , Ito Nui , Kimura Tooru , Kiso Yoshiaki 
Published: July 2008

AbstractA novel strategy for a more efficient synthesis of difficult sequence‐containing peptides, the S‐acyl isopeptide method, was developed and successfully applied. A model pentapeptide Ac–Val–Val–Cys–Val–Val–NH2 was synthesized via its water‐soluble S‐acyl isopeptide using an S‐acyl isodipeptide unit, Boc–Cys(Fmoc–Val)–OH. An S‐acyl isopeptide possessing excellent water solubility could be readily and quantitatively converted to the native peptide via an SN intramolecular acyl migration reaction at pH 7.4. Thus, the S‐acyl isopeptide method provides a useful tool in peptide chemistry. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Optical and dielectric properties of ZnO‐PVA nanocomposites
Authors: Bouropoulos N. , Psarras G. C. , Moustakas N. , Chrissanthopoulos A. , Baskoutas S. 
Published: July 2008

AbstractNanocomposites of polyvinyl alcohol and ZnO were prepared using the solution casting method. ZnO nanoparticles with hexagonal wurtzite structure and mean sizes of 59, 82 and 150 nm were prepared by thermal decomposition of zinc acetate dihydrate. The synthesized crystals were characterized by X‐ray diffraction (XRD), and scanning electron microscopy (SEM). Optical properties of the nanocomposites were determined using UV–visible absorption spectroscopy. The results showed that all samples appeared near band edge absorption close to the bulk value. Furthermore, broadband dielectric spectroscopy, at ambient temperature, was employed in order to investigate the effect of mean particle size upon interfacial relaxation phenomena. Dielectric data provide evidence that interfacial polarization, which is present in all three nanocomposite films, shifts to higher frequencies and its intensity is decreasing as the mean nanoparticle diameter is also decreasing. Finally, exploiting the Cole–Davidson approach, becomes evident, that interfacial polarization process acquires a more symmetric form, tending to a pure Debye relaxation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrogen‐assisted nitrogen‐acceptor doping in ZnO
Authors: Lu J. G. , Fujita S. 
Published: July 2008

AbstractN‐doped ZnO (ZnO:N) thin films were prepared by atmospheric pressure mist chemical vapor deposition. The as‐grown ZnO:N film was of high resistivity with ambiguous carrier type, while the annealed sample showed p‐type conductivity with a resistivity of 22.3 Ω cm and hole concentration of 5.49 × 1017 cm–3. The crystallinity of ZnO films was improved by the annealing treatment. Unintentionally H impurities introduced into the as‐grown film could be annealed out and a near‐edge absorption related to the N states in band gap was present in the annealed sample, which was indicative of the appearance of activated N in ZnO during the annealing process. A hydrogen‐assisted nitrogen‐acceptor doping mechanism was proposed to explain the observation of p‐type ZnO. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)