bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic/Inorganic bioactive materials Part II: in vitro bioactivity of Collagen-Calcium Phosphate Silicate/Wollastonite hybrids
Authors: Radev Lachezar , Hristov Vladimir , Samuneva Bisserka , Ivanova Dimitrina 
Published: October 2009

Abstract
In the present study, novel hybrid materials of Collagen (C) and Calcium Phosphate Silicate/Wollastonite (CPS/W) were synthesized. The CPS/W ceramic was prepared via polystep sol-gel method. The dissolution test of CPS/W ceramic was filled with TRIS-HCl buffer. FTIR depicts that hydroxyl carbonate apatite (OHCO3HA) was observed after 3 days of immersion in TRIS-HCl buffer. Biohybrids of C-CPS/W were produced from diluted hydrochloric acid collagen type I and ceramic powder with different ratios of C and CPS/W equal to 25:75 and 75:25 wt.%. The synthesized hybrids were characterized by FTIR, XRD and SEM. FTIR depicts a “red shift” if amide I could be attributed to the fact that the collagen prefers to chelate Ca2+ from partial dissolution of CPS/W ceramic. The growth of B-type carbonate containing hydroxyapatite (B-CO3HA) on the C-CPS/W hybrids soaked in 1.5SBF was observed. The negatively charged carboxylate groups from the collagen may be responsible for hydroxyapatite (HA) deposition. This fact was confirmed by the “red shift” of carboxylate groups of collagen in FTIR spectra. The formation of HA was observed by FTIR, XRD and SEM.
Organic/Inorganic bioactive materials Part III: in vitro bioactivity of gelatin/silicocarnotite hybrids
Authors: Radev Lachezar , Fernandes Maria , Salvado Isabel , Kovacheva Daniela 
Published: October 2009

Abstract
In this work we present our experimental results on synthesis, structure evolution and in vitro bioactivity assessment of new gelatin/silicocarnotite hybrid materials. The hybrids were obtained by diluting gelatin (G) and silicocarnotite (S) ceramic powder with G:S ratios of 75:25 and 25:75 wt.% in hot (40°C) water. The hybrids were characterized using XRD, FTIR, SEM/EDS and XPS. FTIR depicts that the “red shift” of amide I and COO− could be attributed to the fact that the gelatin prefers to chelate Ca2+ from S. The growth of calcium phosphates on the surface of the hybrids synthesized and then immersed in 1.5 SBF for 3 days was studied by using of FTIR, XRD and SEM/EDS. According to FTIR results, after an immersion of 3 days, A and B-type CO3HA can be observed on the surface. XRD results indicate the presence of hydroxyapatite with well defined crystallinity. SEM/EDS of the precipitated layers show the presence of CO3HA and amorphous calcium phosphate on the surface of samples with different G/S content when immersed in 1.5 SBF. XPS of the G/S hybrid with 25:75 wt.% proved the presence of Ca-deficient hydroxyapatite after an in vitro test for 3 days.
Calorimetric study of melts in the system KF - K2TaF7
Authors: Nerád Ivan , Mikšíková Eva , Balogová Zuzana 
Published: October 2009

Abstract
Enthalpy increment measurements on melts in the system KF-K2TaF7 were carried out by drop calorimetry at temperatures between 298 K and 1063, 1103 and 1143 K for selected compositions. Heat capacities of the melted mixtures and enthalpies of mixing have been determined. Careful calorimetric experiments showed small but distinct non-ideality of the melt. The molar heat capacity of melt exhibits small positive divergence from additivity. The molar enthalpy of mixing shows negative deviation from ideality which decreases with increasing temperature. The thermal effect at mixing was assigned predominantly to association reactions producing more complex fluorotantalate anions. The formation of complex anions with lower coordination number of Ta may not be excluded.
Investigation of FIrpic in PhOLEDs via LC/MS technique
Authors: Sivasubramaniam Varatharajan , Brodkorb Florian , Hanning Stephanie , Loebl Hans , Elsbergen Volker , Boerner Herbert , Scherf Ullrich , Kreyenschmidt Martin 
Published: October 2009

Abstract
The commercial breakthrough of phosphorescent organic white light sources is presently hampered due to the unavailability of a stable blue phosphorescent emitter material. Moreover, only few analytical investigations have been made regarding the chemical degradation of the phosphorescent emitter materials during the processing or the operation of the devices. Organic light emitting devices (OLEDs) containing phosphorescent metal complexes with iridium as central ion were investigated. Special attention was paid to the chemical degradation of the material. The devices were analyzed by means of high performance liquid chromatography coupled with mass spectrometry (HPLC/MS). Electron spray ionization (ESI) was employed as ionization source. Isomerization phenomena of the blue-green emitting heteroleptic iridium complex FIrpic could be observed after the device manufacture and after operation. These findings could give hints on the mechanisms that influence the lifetime of PhOLEDs based on FIrpic or similar blue emitters.
Mechanistic aspects of oxidation on L-tyrosine by diperiodatocuprate(III) complex in alkali media: a kinetic model
Authors: Shetti Nagaraj , Hegde Rajesh , Nandibewoor Sharanappa. 
Published: October 2009

Abstract
Oxidation of an amino acid, L-tyrosine (L-Tyr) by diperiodatocuprate(III) (DPC) in alkaline medium at a constant ionic strength of 0.1 mol dm−3 was studied spectrophotometrically at different temperatures (288.1–313.1 K). The reaction between DPC and L-Tyr in alkaline medium exhibits 1:4 stoichiometry (L-Tyr:DPC). Intervention of free radicals was observed in the reaction. Based on the observed orders and experimental evidence, a mechanism involving monoperiodatocuprate(III) (MPC) as the reactive oxidant species has been proposed. A suitable mechanism is proposed through the formation of a complex and free radical intermediate. The products were identified by spot test and characterized by spectral studies. The reaction constants involved in the different steps of the mechanism were calculated. The activation parameters with respect to slow step of the mechanism were computed and are discussed. The thermodynamic quantities were determined for different equilibrium steps. Isokinetic temperature was also calculated and found to be 252.3 K.
Comparison of the efficacy of sulfurization agents in decreasing the sheet resistance of polyamide and polyethylene with copper sulfide layers and influence of their compositions
Authors: Ivanauskas Remigijus , Ancutienė Ingrida , Janickis Vitalijus , Stokienė Rūta 
Published: October 2009

Abstract
The process of obtaining semiconductive and electrical conductive layers of copper sulfides by the sorption — diffusion method on polymers (polyamide 6 and low density polyethylene) using solutions of potassium pentathionate, K2S5O6, and higher polythionic acids, H2Sn O6 (n = 21, 33), was investigated. The layers were characterized for compositional and electrical properties by X-ray diffraction (XRD) analysis and sheet resistance measurements. The thickness of copper sulfides layers on polyamide and polyethylene increased with increasing time of polymer sulfurization and varied from 10 to 43 µm. The variations of the sheet resistance of copper sulfides layers formed on the surface of polymers on sulfurization agent used, the conditions of sulfurization, chemical and phase composition of the obtained layers were established. Sheet resistance of copper sulfides layers decreases with increasing time of the duration of sulfurization and the number of sulfur atoms in the polythionate anion. The sheet resistance values for copper sulfide layers formed on the polyamide surface are much lower than those of Cux S formed on the polyethylene surface. XRD showed the predomination of Cux S phases with low x values.
Solid phase selective separation and green preconcentration of Cu, Zn, Pb and Cd in drinking water by using novel functionalized resin
Authors: Burham Nagwa , Azeem Sami , El-Shahat Mohamed 
Published: October 2009

Abstract
A new solid — phase extraction sorbent was developed based on stepwise anchoring of two ligand molecules for the determination of copper, zinc, lead and cadmium in drinking water by flame AAS. Amberlite XAD-2 functionalized with 4′-(2-hydroxyphenylazo)-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one (HPAPyr) was utilized for preconcentration/separation of these elements. The sorbent was prepared by two successive azo coupling reactions. First, 2-aminophenol was anchored to the amino groups in the resin resulted from nitration followed by reduction. Then, the resulted 2-aminophenol functionalized resin was further diazotized and coupled to the pyrazolone compound and the final product HPAPyr-XAD-2 was characterized by IR and elemental analysis. The optimum pH range for sorption, shaking time, exchange capacity, sample flow rate, preconcentration factor and interference from co-existing ions were investigated. All metal ions were quantitatively desorbed from the resin by 4.5 mol L−1 nitric acid solution. The sorbent provides limit of detection within the range 0.9–3.3 µg L−1 and concentration factor up to 250. The procedure was validated by analysis of certified material NIST-SRM 1577b. Application to drinking water showed satisfactory results with relative standard deviation RSD ≤ 8.5%.
A theoretical study of the neutral and the double-charged cation of cyclo[8]pyrrole and its interaction with inorganic anions
Authors: Alkorta Ibon , Blanco Fernando , Elguero José 
Published: October 2009

Abstract
A theoretical study of the complexation of cyclo[8]pyrrole dication, 2, and the corresponding system in neutral form, 3, with six anionic molecules has been carried out up to the B3LYP/6–311++G(2d,2p) computational level. The effect of the water solvation has been taken into account by means of the PCM method. The gas phase results correspond to the very large interaction energies expected for the interaction of molecules of opposite charge. In all the complexes, the analysis of the electron density by means of the Atoms In Molecules (AIM) methodology shows the presence of eight intermolecular interactions between the individual molecules. The results, using the water solvent model, indicate that the 2:SO42− complex is more stable than the 2:NO3−, in agreement with experimental results.
Atom transfer radical polymerization in aqueous dispersed media
Authors: Min Ke , Matyjaszewski Krzysztof 
Published: October 2009

Abstract
During the last decade, atom transfer radical polymerization (ATRP) received significant attention due to its exceptional capability of synthesizing polymers with pre-determined molecular weight, well-defined molecular architectures and various functionalities. It is economically and environmentally attractive to adopt ATRP to aqueous dispersed media, although the process is challenging. This review summarizes recent developments of conducting ATRP in aqueous dispersed media. The issues related to retaining “controlled/living” character as well as colloidal stability during the polymerization have to be considered. Better understanding the ATRP mechanism and development of new initiation techniques, such as activators generated by electron transfer (AGET) significantly facilitated ATRP in aqueous systems. This review covers the most important progress of ATRP in dispersed media from 1998 to 2009, including miniemulsion, microemulsion, emulsion, suspension and dispersed polymerization.
Tables of Rosseland mean opacities for candidate atmospheres of life hosting free-floating planets
Authors: Badescu Viorel 
Published: October 2009

Abstract
The existence of life on a free-floating planet is conditioned by the existence of an optically thick atmosphere. This may ensure the long-term thermal stability of a (liquid) solvent on the surface of that body. Requirements to be fulfilled by a hypothetic gas constituent of a free-floating planet atmosphere are studied. The four gases analyzed here (nitrogen, carbon dioxide, methane and ethane) are candidates. They may induce a higher opacity than molecular hydrogen, which has been considered in previous research. The paper deals with preparation of tables of Rosseland mean opacity values. Selection of the ranges of temperature and pressure is guided by life existence considerations. The range of temperatures involved (50 to 650 K) is lower than usually found in the literature. The tables may be useful for studies related to free-floating planets, where the usage of absorption opacity is a straightforward way to compute the energy flux in the atmosphere. Also, the results are useful in all cases where radiation is transferred through dense layers of the gases considered in this paper.
Proposal to improve the behaviour of self-energy contributions to the S-matrix
Authors: Tóth Gábor 
Published: October 2009

Abstract
A simple modification of the definition of the S-matrix is proposed. It is expected that the divergences related to nonzero self-energies are considerably milder with the modified definition than with the usual one. This conjecture is verified in a few examples using perturbation theory. The proposed formula is written in terms of the total Hamiltonian operator and a free Hamiltonian operator and is therefore applicable in any case when these Hamiltonian operators are known.
Genetic analysis and putative role in resistance to antivirals of the human cytomegalovirus DNA polymerase UL44 processivity factor
Authors: Boutolleau David , Deback Claire , Bressollette-Bodin Céline , Conan Françoise , Aït-Arkoub Zaïna , Imbert-Marcille Berthe-Marie , Agut Henri 
Published: October 2009

Background The human cytomegalovirus (HCMV) DNA polymerase is composed of the UL54 catalytic subunit and the UL44 accessory protein. UL44 increases the processivity of polymerase along the DNA template during replication and, incidentally, is a substrate for the UL97 phosphotransferase. The molecular mechanisms of HCMV resistance to antiviral drugs interfering with viral DNA synthesis reported so far only rely on the presence of amino acid changes within the UL97 and UL54 viral enzymes. We aimed to describe the natural polymorphism of UL44 and to analyse the changes of its amino acids potentially associated with HCMV resistance to antivirals. Methods The full-length UL44 gene sequence was compared to that of four reference strains (including the AD169 strain) and 43 clinical strains from patients who had not received any previous anti-HCMV treatment, and 25 blood samples from 15 HCMV-infected patients experiencing therapeutic failure and exhibiting genotypic traits of HCMV resistance to antivirals. Results Overall, seven different amino acid changes associated with natural polymorphisms were identified among the 433 residues of the UL44 protein, occurring at a frequency of 2.1% for five of them and 10.6% for the double change G296S+L319I. The analysis of the HCMV strains exhibiting genotypic resistance to antivirals did not show any changes in UL44 that had significant association with resistance mutations of UL97 and/or UL54. Conclusions UL44 processivity factor exhibits a very low polymorphism that does not concern the assumed functional domains of the protein. From this preliminary study, UL44 does not seem to be involved in HCMV resistance to antivirals.
Nanoparticle Electroluminescence: Controlling Emission Color Through Förster Resonance Energy Transfer in Hybrid Particles
Authors: Huebner Christopher F. , Roeder Ryan D. , Foulger Stephen H. 
Published: October 2009

AbstractElectroluminescent (EL) polymers are attractive for developing all‐organic light‐emitting devices (OLEDs) due to the potential advantages that polymeric systems may offer in the large‐scale manufacturing of electronics. Nonetheless, many of these EL π‐conjugated polymers are inherently insoluble in the solvents employed in the intended solution‐based manufacturing processes. One such polymer is poly(2,5‐dioctyl‐1,4‐phenylenevinylene) (POPPV), where the inherent lack of solubility of POPPV in organic solvents has frustrated its widespread application in devices and no OLEDs have been presented that exploit its electroluminescence characteristics. In this effort, a unique strategy is presented for the preparation of hybrid nanoparticles composed of POPPV, a green emitter (λem = 505 nm) and poly(9,9‐di‐n‐octylfluorenyl‐2,7‐diyl) (PFO), a blue emitter (λem = 417 nm). The aqueous‐based nanoparticle dispersion composed of these hybrid particles is stable to aggregate and can be employed in the construction of OLEDs. The color characteristics of the electroluminescence for the devices can be tuned by exploiting the Förster resonance energy transfer between the polymers within a particle, while suppressing energy transfer between the particles. These aqueous‐based nanoparticle dispersions are amenable to being printed into devices through high‐throughput manufacturing techniques, for example, roll‐to‐roll printing.
B–Z DNA Transition Triggered by a Cationic Comb‐Type Copolymer
Authors: Shimada Naohiko , Kano Arihiro , Maruyama Atsushi 
Published: October 2009

AbstractThe conformational transition from right‐handed B–DNA to left‐handed Z–DNA—the B–Z transition—has received increased attention recently because of its potential roles in biological systems and its applicability to bionanotechnology. Though the B–Z transition of poly(dG–dC) · poly(dG–dC) is inducible under high salt concentration conditions (over 4 M NaCl) or by addition of multivalent cations, such as hexaamminecobalt(III), no cationic polymer were known to induce the transition. In this study, it is shown by circular dichroism and UV spectroscopy that the cationic comb‐type copolymer, poly(L‐lysine)‐graft‐dextran, but not poly(L‐lysine) homopolymer or a basic peptide, induces the B–Z transition of poly(dG–dC) · poly(dG–dC). At a cationic amino group concentration of 10−4 M the copolymer stabilizes Z–DNA. The transition pathway from the B to the Z form is different to that observed previously. We speculate that the cationic backbone of the copolymer, which reduces electrostatic repulsion among DNA phosphate groups, and the hydrophilic dextran chains, which reduce activity of water, cooperate to induce the B–Z transition. The copolymer specifically modified the micro‐environment around DNA molecules to induce Z–DNA formation through stable and spontaneous inter‐polyelectrolyte complex formation.
The importance of product cut and form when estimating fish demand: the case of U.S. Catfish
Authors: Muhammad Andrew , Hanson Terrill R. 
Published: October 2009

AbstractThe absolute price version of the Rotterdam model was used in the estimation of U.S. catfish demand where catfish was differentiated by product cut (whole, fillet, and other) and product form (fresh and frozen). Likelihood ratio tests were used to determine the importance of product form in demand (product form aggregation). Likelihood ratio tests were also used to determine if fresh products were separable from frozen products (product form separability). Product form aggregation was rejected at a probability of 0.999, suggesting that fresh and frozen catfish products are not homogenous. The hypothesis, no product form separability, failed to be rejected at the 0.05 significance level, but was rejected at the 0.01 significance level. Test results suggest that it is more acceptable to focus on a single product group (e.g., frozen products) than to assume that catfish products are perfectly aggregatable across product forms. [JEL classifications: Q11, Q13, Q22]. © 2009 Wiley Periodicals, Inc.
Distribution of direct recall costs along the milk chain
Authors: Velthuis A.G.J. , Meuwissen M. , Huirne R.B.M. 
Published: October 2009

AbstractThe relation between time and the direct recall costs of one batch of milk was investigated in this study. We developed a Monte Carlo simulation model of a farm‐to‐consumer supply chain associated with one batch of milk of 150,000 kilograms. The direct recall costs of recalling a batch are less than €100,000 in the first 16 hours after the milk has been collected from the farms, but the costs increase rapidly to more than €140,000. With this study, we showed that a modeling approach can give insight into the relation between recall costs and time, and it can support the development of monitoring schemes at the chain level. [EconLit citations: D210, Q180]. © 2009 Wiley Periodicals, Inc.
Life cycle assessment for the production of biodiesel: A case study in Malaysia for palm oil versus jatropha oil
Authors: Lam Man Kee , Lee Keat Teong , Mohamed Abdul Rahman 
Published: October 2009

AbstractOne of the most promising forms of renewable energy is biodiesel produced from vegetable oils, such as rapeseed, soybean and palm oil. Malaysia, being the world's second‐largest producer of palm oil, therefore begins to align herself as the potential world producer of palm biodiesel apart from exporting palm oil as feedstock for the food and oleochemical industries. However, due to the recent food versus fuel debate, Malaysian palm oil has received a lot of negative attention especially from non‐governmental organizations (NGOs). The sustainability of palm biodiesel production and environmental issues are constantly being questioned. Many quarters have even claimed that the use of non‐edible oils, such as Jatropha curcas L., should be promoted rather than palm oil for biodiesel production. Therefore, this study aims to compare and validate the production of biodiesel from palm and jatropha using the life cycle assessment (LCA) approach. The assessment encompasses the cultivation of the crop, the oil extraction stage and finally, the biodiesel production stage. We found that to produce 1 tonne of jatropha biodiesel, the land area requirement is 118% higher than to produce 1 tonne of palm biodiesel. The energy output‐to‐input ratio for palm biodiesel is 2.27, slightly higher than jatropha biodiesel at 1.92. Furthermore, CO2 sequestration for the whole life cycle chain of palm biodiesel is 20 times higher than jatropha biodiesel. All these results show the superiority and sustainability of palm oil as a feedstock for biodiesel production. Copyright © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
An anatomical study of the muscles that attach to the articular disc of the temporomandibular joint
Authors: Matsunaga Kosuke , Usui Akira , Yamaguchi Kumiko , Akita Keiichi 
Published: October 2009

AbstractThe masticatory muscles are generally described as the muscles that originate from the cranium and insert on the mandible. Some of the masticatory muscles also insert into the articular disc of the temporomandibular joint. Although there are numerous reports of studies on the attachment of the fibers to the disc, most reports discuss only one muscle. We have shown that the masticatory muscles are not simply a group of clearly independent muscles, but that these muscles contain various transitional muscle bundles among the major muscles. From this point of view, we carried out minute dissection of the collective muscles and muscle bundles surrounding the temporomandibular joint. We dissected 40 head halves of 20 Japanese cadavers (10 males, 10 females: average 79.6 yr). After complete removal of the bony elements, the structures surrounding the temporomandibular joint were investigated en‐block. In all specimens, the superior surface of the upper head of lateral pterygoid and the midmedial muscle bundle were attached to the disc. In some specimens, the discotemporal bundle, zygomaticomandibularis, and masseter were attached to the anterior surface of the disc. The total vector of these muscles pulls the disc anteriorly. In contrast, the vector of the muscles to the condylar processes of the mandible pulls the mandible medially. From these observations, it seems that the fibers, which attach to the disc act to steady the disc against the masticatory movement. Clin. Anat. 22:932–940, 2009. © 2009 Wiley‐Liss, Inc.