bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic degradation and controlled drug delivery system studies for sensitive hydrogels prepared by gamma irradiation
Authors: Eid M. , El‐Arnaouty M. B. 
Published: February 2009

AbstractTernary mixtures of N‐vinyl‐2‐pyrrolidone/itaconic acid and gelatin were irradiated by gamma rays at 30 kGy/s and at ambient temperature to prepared poly (NVP/IA and G) hydrogels. Poly (NVP/IA) hydrogels were prepared in different compositions (NVP/IA) mole ratio, (100/0), (98/1.5), (96.5/3.5), and (93/7.0) at 30 kGy. Then adding gelatin at different content (5, 10, 15, 20) mg to the best composition (NVP/IA/H2O) (93/7)% for the characterization of network structure of these hydrogels, kinetic swelling drug release behavior and Scan Electron Microscope was studied. The equilibrium degree of swelling for P(NVP/IA) and P(NVP/IA/G) copolymer and the swelling‐degradation kinetics were also studies. According to dynamic swelling studies, both the diffusion exponent and the diffusion coefficient increase with increasing content of (IA), whereas, the addition of gelatin to (NVP/IA) composition by different content did not lead to any significant change in swelling percent. Also, the swelling behavior of copolymer hydrogels in response to pH value of the external media was studied, it is noted that the highest swelling values were at pH 4. The in vitro drug release behavior of these hydrogels was examined by quantification analysis with a UV/VIS spectrophotometers. Chlorpromazine hydrochloride was loaded into dried hydrogels to investigate the stimuli‐sensitive property at the specific pH and the drug release profile of these pH‐sensitive hydrogels in vitro. The release studies show that the highest value of release was at pH 4 which can be used for drug delivery system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Improving interfacial adhesion between thermoplastic polyurethane and copper foil using amino carboxylic acids
Authors: Ghosh Arun , Schiraldi David A. 
Published: February 2009

AbstractA chemical methodology to improve the adhesion between copper foil and a thermoplastic polyurethane (TPU) matrix is reported. The copper foil (0.127 mm thickness) was treated with aminocarboxylic acid‐based coupling agents such as 6‐aminohexanoic acid and 4‐aminobenzoic acid. 3‐Aminopropyl trimethoxysilane was also used as a conventional silane coupling agent for comparative studies. The interfacial adhesion between copper foil and laminated TPU was examined by means of peel adhesion test, scanning electron microscopy, and attenuated total reflection‐infrared spectroscopic methods. The treatment of copper foils with 6‐aminohexanoic acid resulted in improved adhesion, which was equal to that of the silane‐treated system. The mechanism of how the coupling agents strengthen the interfacial adhesion between TPU and copper foil is discussed. The solution concentrations of the coupling agents were optimized with respect to the peel adhesion of the interface. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Limited proteolysis analysis of the ribosome is affected by subunit association
Authors: Hamburg Daisy‐Malloy , Suh Moo‐Jin , Limbach Patrick A. 
Published: February 2009

AbstractOur understanding of the structural organization of ribosome assembly intermediates, in particular those intermediates that result from misfolding leading to their eventual degradation within the cell, is limited because of the lack of methods available to characterize assembly intermediate structures. Because conventional structural approaches, such as NMR, X‐ray crystallography, and cryo‐EM, are not ideally suited to characterize the structural organization of these flexible and sometimes heterogeneous assembly intermediates, we have set out to develop an approach combining limited proteolysis with matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) that might be applicable to ribonucleoprotein complexes as large as the ribosome. This study focuses on the limited proteolysis behavior of appropriately assembled ribosome subunits. Isolated subunits were analyzed using limited proteolysis and MALDI‐MS and the results were compared with previous data obtained from 70S ribosomes. Generally, ribosomal proteins were found to be more stable in 70S ribosomes than in their isolated subunits, consistent with a reduction in conformational flexibility on subunit assembly. This approach demonstrates that limited proteolysis combined with MALDI‐MS can reveal structural changes to ribosomes on subunit assembly or disassembly, and provides the appropriate benchmark data from 30S, 50S, and 70S proteins to enable studies of ribosome assembly intermediates. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 410–422, 2009.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Detecting cellulase penetration into corn stover cell walls by immuno‐electron microscopy
Authors: Donohoe Bryon S. , Selig Michael J. , Viamajala Sridhar , Vinzant Todd B. , Adney William S. , Himmel Michael E. 
Published: February 2009

AbstractIn general, pretreatments are designed to enhance the accessibility of cellulose to enzymes, allowing for more efficient conversion. In this study, we have detected the penetration of major cellulases present in a commercial enzyme preparation (Spezyme CP) into corn stem cell walls following mild‐, moderate‐ and high‐severity dilute sulfuric acid pretreatments. The Trichoderma reesei enzymes, Cel7A (CBH I) and Cel7B (EG I), as well as the cell wall matrix components xylan and lignin were visualized within digested corn stover cell walls by immuno transmission electron microscopy (TEM) using enzyme‐ and polymer‐specific antibodies. Low severity dilute‐acid pretreatment (20 min at 100°C) enabled <1% of the thickness of secondary cell walls to be penetrated by enzyme, moderate severity pretreatment at (20 min at 120°C) allowed the enzymes to penetrate ∼20% of the cell wall, and the high severity (20 min pretreatment at 150°C) allowed 100% penetration of even the thickest cell walls. These data allow direct visualization of the dramatic effect dilute‐acid pretreatment has on altering the condensed ultrastructure of biomass cell walls. Loosening of plant cell wall structure due to pretreatment and the subsequently improved access by cellulases has been hypothesized by the biomass conversion community for over two decades, and for the first time, this study provides direct visual evidence to verify this hypothesis. Further, the high‐resolution enzyme penetration studies presented here provide insight into the mechanisms of cell wall deconstruction by cellulolytic enzymes. Biotechnol. Bioeng. 2009;103: 480–489. © 2009 Wiley Periodicals, Inc.
3D‐CAD learning environment through interactive modular system (AIMECDT‐3D)
Authors: Pando Cerra Pablo , Alvarez Peñin Pedro , Garcia Diaz Rafael , Perez Morales Maximo 
Published: February 2009

AbstractThe herein presented application allows the betterment of the learning process of 3D‐Computer Assisted Design. In this way the student can easily develop the necessary skills as to the use of the tools by following a regular procedure for grasping the knowledge. For this she/he may use an exercise organizer. Besides, the teacher is allowed to customize the contents and control all the information. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 93–107, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20203
pH‐Dependent Optical Properties of Synthetic Fluorescent Imidazoles
Authors: Berezin Mikhail Y. , Kao Jeff , Achilefu Samuel 
Published: February 2009

AbstractNew pH‐sensitive probe design: A peek into the structure of fluorescent proteins led to the synthesis of fluorescent imidazoles. The prepared compounds demonstrated an array of remarkable pH‐dependent optical properties including at least two types of excited‐state charge transfers (see picture).magnified imageAn imidazole moiety is often found as an integral part of fluorophores in a variety of fluorescent proteins and many such proteins display pH‐dependent light emission. In contrast, synthetic fluorescent compounds with incorporated imidazoles are rare and have not been studied as pH probes. In this report, the richness of imidazole optical properties, including pH sensitivity, was demonstrated by means of a novel imidazole‐based fluorophore 1H‐imidazol‐5‐yl‐vinylbenz[e]indolium. Three species corresponding to protonated, neutral, and deprotonated imidazoles were identified in the broad range of pH 1–12. The absorption and emission bands of each species were assigned by comparative spectral analysis with synthesized mono‐ and di‐N‐methylated fluorescent imidazole analogues. pKa analysis in the ground and the excited states showed photoacidic properties of the fluorescent imidazoles due to the excited state proton transfer (ESPT). This effect was negligible for substituted imidazoles. The assessment of a pH‐sensitive center in the imidazole ring revealed the switching of the pH‐sensitive centers from 1‐N in the ground state to 3‐N in the excited state. The effect was attributed to the unique kind of the excited state charge transfer (ESCT) resulting in a positive charge swapping between two nitrogens.
Cyclic RGD‐Containing Functionalized Azabicycloalkane Peptides as Potent Integrin Antagonists for Tumor Targeting
Authors: Manzoni Leonardo , Belvisi Laura , Arosio Daniela , Civera Monica , Pilkington‐Miksa Michael , Potenza Donatella , Caprini Andrea , Araldi Elena M. V. , Monferini Eugenia , Mancino Monica , Podestà Francesca , Scolastico Carlo 
Published: February 2009

AbstractVitronectin receptors αvβ3 and αvβ5 have emerged as potential therapeutic targets for the treatment of osteoporosis, restenosis, ocular disease, tumor‐induced angiogenesis, metastasis, and sickle‐cell anemia. Among a collection of compounds, a new potent integrin antagonist was synthesized, and its binding toward the αvβ3 and αvβ5 receptors was evaluated. This molecule is a suitable candidate as a vector for therapeutics and diagnostics.magnified imageCyclic RGD‐containing functionalized azabicycloalkane peptides were synthesized with the aim of developing high‐affinity selective integrin ligands as carriers for therapeutic and diagnostic purposes. Herein we describe the synthesis and in vitro screening of these RGD derivatives, as well as the determination of their conformational properties in solution by spectroscopic and computational methods. Docking studies with the X‐ray crystal structure of the extracellular domain of integrin αvβ3 were also performed to elucidate the structural binding requirements and to rationalize the biological results. One compound in particular was found to be the best αvβ3 integrin binder (IC50=53.7 nM) among the new functionalized RGD cyclic peptides, thus emerging as a promising candidate for covalent bonding and selective homing of useful functional units.
Dose‐escalated radiation therapy for intermediate‐risk prostate cancer
Authors: Liauw Stanley L. , Fricano Janine , Correa David , Weichselbaum Ralph R. , Jani Ashesh B. 
Published: February 2009

AbstractBACKGROUND:Randomized trials supported the use of androgen deprivation therapy (ADT) with radiation therapy (RT) for intermediate‐risk prostate cancer. However, the value of concurrent ADT was less certain with dose‐escalated RT. Better methods of stratifying patients in this risk group may help select patients who are most likely to benefit.METHODS:A total of 238 men with intermediate‐risk (prostate specific antigen [PSA] 10‐20, Gleason 7, or stage T2b‐c) adenocarcinoma of the prostate were treated with external beam RT between 1989 and 2006. Patients had Gleason≤6 (39%) or 7 (61%) tumors; median PSA was 10.5 ng/mL. A median of 37.5% of biopsy cores were positive from a median of 9 biopsy cores sampled. The median RT dose was 74 Gy to the prostate. A total of 112 patients (47%) received neoadjuvant and concurrent ADT (median, 4 months). Median follow‐up period was 49 months.RESULTS:The freedom from biochemical failure (FFBF, nadir + 2 definition) was 93% at 3 years, 86% at 4 years, and 80% at 5 years. On univariate analysis, the only factor associated with FFBF was percentage of positive cores (PPC, P = .0340). The prognostic value of PPC≥50 was not evident in patients receiving ADT (FFBF at 4 years 90% vs 91%, P = .3015). For patients not receiving ADT, the impact of PPC≥50 (FFBF at 4 years 76% vs 93%, P = .0844) was more pronounced. On multivariate analysis, PPC (P = .0388) was significantly associated with FFBF, whereas Gleason sum, ADT, RT dose, PSA, and T‐stage were not.CONCLUSIONS:After dose‐escalated external beam RT, intermediate‐risk prostate cancer patients with PPC≥50 had the highest risk for biochemical failure and may be most likely to derive a benefit from ADT. Cancer 2009. © 2009 American Cancer Society.
Identification of 12 or more lymph nodes in resected colon cancer specimens as an indicator of quality performance
Authors: Dillman Robert O. , Aaron Kenneth , Heinemann F. Scott , McClure Stephanie E. 
Published: February 2009

AbstractBACKGROUND:Identification of ≥12 lymph nodes in resected colon cancer specimens has been endorsed as a quality indicator.METHODS:The Hoag Hospital cancer registry was used to identify patients diagnosed with colon cancer. The proportion of colon cancer specimens for which ≥12 lymph nodes were identified was determined by anatomic location, stage of disease, patient age, and operating surgeon. Survival was correlated with stage and with whether ≥12 lymph nodes were identified.RESULTS:Pathology procedural changes in 1998 were associated with an increase in the average number of lymph nodes identified from 8.0 to 14.5 (P < .0001); therefore, analysis was limited to 574 patients who underwent surgical resection of colon adenocarcinoma during 1998 to 2005. Identification of ≥12 lymph nodes varied from 57% to 83% by 7 anatomic locations (P < .0001), from 65% to 75% by 5 age cohorts (P = .027), from 59% to 73% by 4 general stages of disease (P = .004), and from 53% to 80% among 12 surgeons who performed at least 17 resections (P = .014). The proportion of resections in which ≥12 lymph nodes were identified was higher for 3 colorectal fellowship‐trained surgeons compared with the other 9 surgeons (77% vs 63%, P = .0007), and with 30 surgeons who each performed <10 resections (77% vs 51%, P < .0001). Identification of ≥12 lymph nodes was associated with better survival for patients with stage I (P = .016) and stage II (P = .021) disease.CONCLUSIONS:Anatomic location, colorectal surgical training, and case volume were strongly correlated with the number of lymph nodes identified. Cancer 2009. © 2009 American Cancer Society.
Accessing RDF(S) data resources in service‐based Grid infrastructures
Authors: Esteban Gutiérrez Miguel , Kojima Isao , Mirza Pahlevi Said , Corcho Óscar , Gómez‐Pérez Asunción 
Published: February 2009

AbstractWe describe the results of the RDF(S) activity within the Open Grid Forum (http://www.ogf.org) (OGF) Database Access and Integration Services (DAIS) Working Group (http://forge.gridforum.org/projects/dais‐wg) whose objective is to develop standard service‐based grid access mechanisms for data expressed in RDF and RDF Schema. We produce two specifications, focused on the provision of SPARQL querying capabilities for accessing RDF data and a set of RDF Schema ontology handling primitives for creating, retrieving, updating, and deleting RDF data. In this paper we present a set of use cases that justify this work and an overview of these specifications, which will enter in editorial process at OGF25. We conclude by outlining the future work that will be made in the context of this standardization process. Copyright © 2009 John Wiley & Sons, Ltd.
A New View on the Spectrochemical and Nephelauxetic Series on the Basis of Spin‐Polarized Conceptual DFT
Authors: Moens Jan , Jaque Pablo , De Proft Frank , Geerlings Paul 
Published: February 2009

AbstractIn a row: Chemical concepts from the spin‐polarized conceptual DFT field are used to explain the spectrochemical and nephelauxetic series within a group of ruthenium complexes.magnified imageThe spectrochemical and nephelauxetic series are analyzed within the context of spin‐polarized conceptual DFT. For a series of different [RuL6]x complexes, the local spin‐philicity ${\omega _{{\rm{S}}{\rm{,Metal}}}^ + }$ condensed on the metal ion shows a remarkable analogy with some semi‐empirical scales of the spectrochemical series. The local ${f_{{\rm{SS}}{\rm{,Metal}}}^ + }$ Fukui function in turn can be linked to the nephelauxetic effect. Herein, we present a non‐empirical, unified approach for a quantitative discussion of both series.
Xenopus, an ideal model system to study vertebrate left‐right asymmetry
Authors: Blum Martin , Beyer Tina , Weber Thomas , Vick Philipp , Andre Philipp , Bitzer Eva , Schweickert Axel 
Published: February 2009

AbstractVertebrate organ laterality is manifested by the asymmetric morphogenesis and placement of inner organs. Asymmetric induction of the Nodal signaling cascade in the left lateral plate mesoderm (LPM) precedes and is essential for asymmetric organ morphogenesis. While the Nodal cascade is highly conserved, symmetry breakage is considered to vary between the different classes of the vertebrates. In Xenopus, early determinants at cleavage stages were thought to break symmetry, opposed to cilia‐driven leftward flow in mammals and fish. The main objectives of this review are to emphasize the conserved nature of symmetry breakage, and to demonstrate the power of Xenopus embryology to analyze and manipulate flow. In addition, mutant phenotypes described in other model organisms can easily be mimicked in frog by single or multiple knockdowns in combination with experimental manipulations and flow analysis. Xenopus, therefore, is ideally suited to address the major open questions in the field. Developmental Dynamics 238:1215–1225, 2009. © 2009 Wiley‐Liss, Inc.
Syntheses and Crystal Structures of the First Zinc Complex with 1,3,5‐Triaza‐7‐phosphaadamantane (PTA), [ZnCl2(PTA)2], and of the Hybrid Organic–Inorganic Salts of N‐Methyl‐1,3,5‐triaza‐7‐phosphaadamantane with Tetrahalozinc [PTA–Me]2­[ZnI2X2] (X = I, Cl)
Authors: Smoleński Piotr , Benisvy Laurent , Guedes da Silva M. Fátima C. , Pombeiro Armando J. L. 
Published: February 2009

AbstractThe ZnII compounds [ZnCl2(PTA)2] (1) (PTA = 1,3,5‐triaza‐7‐phosphaadamantane) and [PTA–Me]2[ZnI2X2] [X = Cl (2a), X = I (2b); PTA–Me = N‐methyl‐1,3,5‐triaza‐7‐phosphaadamantane] have been prepared by treating ZnCl2 with PTA and [PTA–Me]I, respectively, in methanol at room temperature. They are soluble in polar solvents such as water and methanol, stable in air, and have been characterized by IR, 1H NMR, 31P{1H} NMR, and 13C{1H} NMR spectroscopy, ESI‐MS, elemental and single‐crystal X‐ray diffraction structural analyses (for 1 and 2a). Compound 1 exhibits a nearly regular tetrahedral Zn coordination, with the PTA ligands displaying the uncommon N‐coordination with a low 31P NMR coordination shift. The molecular structure of 2a bears one discrete tetrahedral [ZnI2Cl2]2– anion and two cage‐like [PTA–Me]+ cations, one of them being located in a void. Compound 1 represents the first example of a Zn complex bearing PTA or any derived ligand with a cage‐like PTA core.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Mono‐, Bi‐ and Tridentate N‐Heterocyclic Carbene Ligands for the Preparation of Transition‐Metal‐Based Homogeneous Catalysts
Authors: Corberán Rosa , Mas‐Marzá Elena , Peris Eduardo 
Published: February 2009

AbstractThis microreview focuses on the preparation of homogeneous catalysts of group 8–11 metals containing N‐heterocyclic carbene ligands. The current status of the design of mono‐, bi‐ and tridentate NHC ligands is reviewed through the description of the authors' own work. The catalytic applications of such complexes include hydrogen‐borrowing, C–C coupling, reduction of double bonds and C–H activation reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Particle trajectory calculations with a two‐step three‐time level semi‐Lagrangian scheme well suited for curved flows
Authors: de Almeida Ricardo Carvalho , Costa Giovana Araújo Siqueira , da Fonseca Luiz Claudio Monteiro , Alves José Luis Drummond 
Published: February 2009

AbstractThis study proposes a new two‐step three‐time level semi‐Lagrangian scheme for calculation of particle trajectories. The scheme is intended to yield accurate determination of the particle departure position, particularly in the presence of significant flow curvature. Experiments were performed both for linear and non‐linear idealized advection problems, with different flow curvatures. Results for simulations with the proposed scheme, and with three other semi‐Lagrangian schemes, and with an Eulerian method are presented. In the linear advection problem the two‐step three‐time level scheme produced smaller root mean square errors and more accurate replication of the angular displacement of a Gaussian hill than the other schemes. In the non‐linear advection experiments the proposed scheme produced, in general, equal or better conservation of domain‐averaged quantities than the other semi‐Lagrangian schemes, especially at large Courant numbers. In idealized frontogenesis simulations the scheme performed equally or better than the other schemes in the representation of sharp gradients in a scalar field. The two‐step three‐time level scheme has some computational overhead as compared with the other three semi‐Lagrangian schemes. Nevertheless, the additional computational effort was shown to be worthwhile, due to the accuracy obtained by the scheme in the experiments with large time steps. The most remarkable feature of the scheme is its robustness, since it performs well both for small and large Courant numbers, in the presence of weak as well strong flow curvatures. Copyright © 2009 John Wiley & Sons, Ltd.
The psychoneuroimmunology of depression
Authors: Leonard Brian E. , Myint Ayemu 
Published: February 2009

AbstractChronic stress, by initiating changes in the hypothalamic‐pituitary‐adrenal (HPA) axis and the immune system, acts as a trigger for anxiety and depression. There is experimental and clinical evidence that the rise in the concentration of pro‐inflammatory cytokines and glucocorticoids, which occurs in a chronically stressful situation and also in depression, contribute to the behavioural changes associated with depression. A defect in serotonergic function is associated with these hormonal and immune changes. Neurodegenerative changes in the hippocampus, prefrontal cortex and amygdalae are the frequent outcome of the changes in the HPA axis and the immune system. Such changes may provide evidence for the link between chronic depression and dementia in later life. Copyright © 2009 John Wiley & Sons, Ltd.
Rapid responses of a melanophore cell line to chemical contaminants in water
Authors: Iuga Aurel , Lerner Ethan , Shedd Tommy R. , van der Schalie William H. 
Published: February 2009

AbstractWe have evaluated a Xenopus cell line as a potential sensor for detecting toxins in water. X. laevis melanophores responded rapidly by dispersing melanosomes following exposure to six (ammonia, arsenic, copper, mercury, pentachlorophenol and phenol) of 12 tested chemicals in the desired sensitivity range. For two additional chemicals (nicotine and paraquat) the melanophore response improved upon the response capabilities of several available toxicity sensors. These results suggest that a melanophore‐based sensor could be useful for the rapid assessment of chemical toxicity in drinking water. Published 2009 by John Wiley and Sons, Ltd.