http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/890346.htmlPhotochemical release of nitric oxide (NO) from the S-nitroso derivatives of glutathione, L-cysteine, N-acetyl-L-cysteine, L-cysteinemethylester, D,L-penicillamine, N-acetyl-D,L-penicillamine, and N-acetylcysteamine has been investigated at neutral and acidic pH. The release of NO from RSNO is one of the key reactions that could be utilized in photodynamic therapy. The UV-VIS and HPLC analyses have shown that under argon saturated conditions, disulfide (RSSR) is the major product of UV as well as sunlight induced decomposition. While in aerated conditions, nitirite—the end product of the oxidation of NO—was also observed along with disulfide. The formation of thiyl radical as the intermediate was reconfirmed by laser flash photolysis. The initial rate of formation of NO was on the order of 10−5 dm3 mol−1 s−1. The quantum yields of these reactions were in the range of 0.2–0.8. The high quantum yields observed in the photo induced release of NO from RSNO using both UV and sunlight demonstrate the potential application of these reactions in photodynamic therapy.Manoj M. Veleeparampil, Usha K. Aravind, and C. T. Aravindakumar© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/365949.htmlElectronic spectra of copper(II) complexes CuL2 and Cu2L2Ac2 (L-2-[2-hydroxy-phenil]-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine, Ac –CH3COO-) (L) in chloroform are studied. It is shown that complex Cul2 has rhombic bipyramid polyhedron and complex Cu2L2Ac2 has tetragonal pyramidal polyhedron of copper ion. Results of definition of geometry for complexes in solution correlate with structure of solid complexes.S. N. Bolotin, E. L. Isaeva, M. H. Shamsutdinova, K. S. Pushkareva, and N. N. Bukov© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/631815.htmlWe report the synergetic effect between palladium and indium oxide on hydrogen production in the steam reforming reaction of ethyl alcohol. The palladium/indium oxide catalyst shows higher hydrogen production rate than indium oxide and palladium. Palladium/indium oxide affords ketonization of ethyl alcohol with negligible by-product carbon monoxide, while indium oxide mainly affords dehydration of ethyl alcohol, and palladium affords decomposition of ethyl alcohol with large amount of by-product carbon monoxide. The catalytic feature of palladium/indium oxide can be ascribed to the formation of palladium-indium intermetallic component during the reaction as confirmed by X-ray diffraction and X-ray photoelectron spectroscopic measurements.Tetsuo Umegaki, Yusuke Yamada, Atsushi Ueda, Nobuhiro Kuriyama, and Qiang Xu© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/146849.htmlThe reversible control of primary and secondary self-assemblies was attained using a poly(4-allyloxystyrene)-block-polystyrene diblock copolymer (PASt-b-PSt) through variations in temperature. The copolymer showed no self-assembly in cyclohexane over 35∘C and existed as a unimer with a 37.1 nm hydrodynamic diameter. When the temperature was lowered to 30∘C, the copolymer formed micelles with 269.9 nm by the primary self-assembly. As the result of further lowering the temperature to 20∘C, the secondary self-assembly of the micelles occurred to produce ca. 2975.9 nm aggregates. The aggregates were dissociated into unimers by increasing the temperature up to 40∘C. The light scattering studies demonstrated that the thermoresponsivity of the copolymer showed good hysteresis throughout the variation in the temperature in the range between 20 and 40∘C, based on the Marquadt analysis of the hydrodynamic diameter distribution. It was found that the primary and secondary self-assemblies of the copolymer were perfectly controlled by the temperature.Eri Yoshida and Satoshi Kuwayama© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/371650.htmlFuchs found phenomena that when high voltage is applied to deionized water filled in two contacted beakers, a floating water bridge forms spontaneously. In this paper, we examined flow direction of water bridge and what effects the addition of electrolytes such as NaCl, NaOH, and NH4Cl to the floating water bridge would give. We found that ionization degree reduced the length of water bridge though insoluble electrolyte Al2O3 had no effect on the length of water bridge.Hideo Nishiumi and Fumitaka Honda© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/927329.htmlThe intrinsic viscosity of the coagulant protein was evaluated from the flow times of the protein solutions through a capillary viscometer, and the results suggested the coagulant protein to be globular. The interactions of the coagulant protein with anionic surfactant sodium dodecyl sulphate (SDS) and sodium dodecyl benzene sulfonate (SDBS) were also investigated by capillary viscometry. We conclude that there is strong protein-surfactant interaction at very low surfactant concentrations, and the behavior of the anionic surfactants in solutions containing coagulant protein is very similar. The viscometry results of protein-SDS system are compared with surface tension, fluorescence, and circular dichroism reported earlier. Combining the results of the four studies, the four approaches seem to confirm the same picture of the coagulant protein-SDS interaction. All the physical quantities when studied as function of surfactant concentration for 0.05% (w/v) protein solution either exhibited a maximum or minimum at a critical SDS concentration.Raymond Maikokera and Habauka M. Kwaambwa© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/309292.htmlSecondary electron energy and angle dependent differential cross sections for the production of cations SiHn+ (n=0–3), H2+ and H+ resulting from dissociative ionization of SiH4by electron collision have been evaluated at fixed incident electron energies of 100 and 200 eV. The semiempirical formulation of Jain and Khare which requires the oscillator strength data as a major input has been employed. In the absence of experimental data for differential cross sections, the corresponding derived integral partial and total ionization cross sections in the energy range varying from ionization threshold to 1000 eV revealed a satisfactory agreement with the available experimental and theoretical data. We have also evaluated the ionization rate coefficients on the basis of calculated partial ionization cross sections and Maxwell-Boltzmann energy distributions.Satyendra Pal, Neeraj Kumar, and Anshu© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/350424.htmlImperfect mixing is a concern in industrial processes, everyday processes (mixing paint, bread machines), and in understanding salt water-fresh water mixing in ecosystems. The effects of imperfect mixing become evident in the unstirred ferroin-catalyzed Belousov-Zhabotinsky reaction, the prototype for chemical pattern formation. Over time, waves of oxidation (high ferriin concentration, blue) propagate into a background of low ferriin concentration (red); their structure reflects in part the history of mixing in the reaction vessel. However, it may be difficult to separate mixing effects from reaction effects. We describe a simpler model system for visualizing density-driven pattern formation in an essentially unmixed chemical system: the reaction of pale yellow Fe3+ with colorless SCN− to form the blood-red Fe(SCN)2+ complex ion in aqueous solution. Careful addition of one drop of Fe(NO3)3 to KSCN yields striped patterns after several minutes. The patterns appear reminiscent of Rayleigh-Taylor instabilities and convection rolls, arguing that pattern formation is caused by density-driven mixing.Sabrina G. Sobel, Harold M. Hastings, and Matthew Testa© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/953198.htmlA previous study of C70 in deuterated benzenes generated evidence suggesting C70 exhibited unique reorientational behavior depending on its environment. We present a comparison of the dynamic behavior of this fullerene, in the solid and solution phases, to explore any unique features between these two phases. The effective correlation times, τCeff, of C70 in the solid state are 2 to 3 times longer than in solution. In the solid state, a noticeable decrease in all the carbons' correlation times is seen between 293 K to 303 K; suggesting a transition from isotropic to anisotropic reorientational behavior at this temperature change. Although C70 in solution experiences van der Waals type interactions, these interactions are not strong enough to slow the solution-state motion below what is observed in the solid state. All observed differences in the diffusion constants, DX and DZ, in solution are smaller than in the solid state suggesting a lower energy of activation between these two modes of reorientation in the liquid phase. A small-step diffusion “like” condition appears to be thermally generated in the solid phase at 323 K.R. M. Hughes, P. Mutzenhardt, and A. A. Rodriguez© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/614362.htmlStudy of effect of myeloperoxidase on quercetin at pH 6.0 indicated quercetin oxidation via the formation of the oxidation product. The stability of quercetin and oxidation product was investigated as a function of time by using spectrophotometric and HPLC techniques. The apparent pseudo first-order rate constants were calculated and discussed.Tatjana Momić, Jasmina Savić, and Vesna Vasić© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/574359.htmlThe electrochemical behavior of pure titanium and titanium alloys in a simulated body fluid (normal saline solution) has been tested, and the results have been reported. The significance of the results for dental use has been discussed. The tests also serve as a screening test for the best alloy system for more comprehensive long-term investigations.Rahul Bhola, Shaily M. Bhola, Brajendra Mishra, and David L. Olson© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/180784.htmlNitrosonium-nitrate NO+NO3− and dinitrogen pentoxide NO2+NO3− ionic crystals were synthesized by laser heating of a condensed oxygen-rich O2-N2 mixture compressed to different pressures, up to 40 GPa, in a diamond anvil cell (DAC). High-pressure/high-temperature Raman and X-ray diffraction studies of synthesized samples disclosed a transformation of NO+NO3− compound to NO2+NO3− crystal at temperatures above ambient and pressures below 9 GPa. High-pressure experiments revealed previously unreported bands in Raman spectra of NO+NO3− and NO2+NO3− ionic crystals. Structural properties of both ionic compounds are analyzed. Obtained experimental results support a hypothesis of a rotational disorder of NO+ complexes in NO+NO3− and indicate a rotational disorder of ionic complexes in NO2+NO3− solid.A. Yu. Kuznetsov, L. Dubrovinsky, A. Kurnosov, M. M. Lucchese, W. Crichton, and C. A. Achete© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/214219.htmlThe limitations and advantages of modern encounter theories of remote transfer are discussed, as well as their application to particular transfer reactions assisted by encounter diffusion. Comparison is made with contact multiparticle theories, Brownian dynamic simulations, and the actual experimental data requiring a distant description of energy and/or electron transfer.Anatoly I. Burshtein© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2009/151489.htmlIron manganese oxides are prepared using a coprecipitation procedure and studied for the conversion of synthesis gas to light olefins and C5+ hydrocarbons. In particular, the effect of a range of preparation variables such as [Fe]/[Mn] molar ratios of the precipitation solution, pH of precipitation, temperature of precipitation, and precipitate aging times was investigated in detail. The results are interpreted in terms of the structure of the active catalyst and it has been generally concluded that the calcined catalyst (at 650C∘ for 6 hours) containing 50%Fe/50%Mn-on molar basis which is the most active catalyst for the conversion of synthesis gas to light olefins. The effects of different promoters and supports with loading of optimum support on the catalytic performance of catalysts are also studied. It was found that the catalyst containing 50%Fe/50%Mn/5 wt.%Al2O3 is an optimum-modified catalyst. The catalytic performance of optimal catalyst has been studied in operation conditions such as a range of reaction temperatures, H2/CO molar feed ratios and a range of total pressures. Characterization of both precursors and calcined catalysts is carried out by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), BET specific surface area and thermal analysis methods such as TGA and DSC.Ali A. Mirzaei, Samaneh Vahid, and Mostafa Feyzi© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/210616.htmlRecently, nitric oxide (NO) has been implicated in the formation of keloids, preferentially formed in dark-skinned persons, and we suspected that pigment melanin itself may play a direct role by adsorbing NO. We tested the ability of cuttlefish sepia melanin to scavenge (adsorb) NO, generated in situ by 2-(N.N Diethylamino) diazeneolate-2-oxide (DEA/NO), through a dialysis membrane. NO was measured as NO2- and NO3- by the Griess method and as N2O3 by trapping experiments with the fluorogenic substrate 4,5-diaminofluorescein (DAF-2). Initial NO2- and NO3- concentrations were significantly lower in the test dialyzates than in controls. Scavenging of NO was rapid enough to compete with DAF adduct formation. Both analytical methods gave comparable results. Adsorbed NO and/or its oxidized products may undergo interactions with melanin, adsorbed O2, and/or dermal material that may lead to keloid formation.Julian M. Menter, Danita Eatman, Mohamed Bayorh, Ahmad M. Dawaghreh, and Isaac Willis© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/127328.htmlAn adsorption microcalorimeter for the simultaneous determination of the differential heat of adsorption and the adsorption isotherm for gas-solid systems are designed, built, and tested. For this purpose, a Calvet heat-conducting microcalorimeter is developed and is connected to a gas volumetric unit built in stainless steel to record adsorption isotherms. The microcalorimeter is electrically calibrated to establish its sensitivity and reproducibility, obtaining K=154.34±0.23 WV−1. The adsorption microcalorimeter is used to obtain adsorption isotherms and the corresponding differential heats for the adsorption of CO2 on a reference solid, such as a NaZSM-5 type zeolite. Results for the behavior of this system are compared with those obtained with commercial equipment and with other studies in the literature.V. Garcia-Cuello, J. C. Moreno-Piraján, L. Giraldo-Gutiérrez, K. Sapag, and G. Zgrablich© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/342976.htmlA methodology to fabricate ultrasoft CoFe nano-/microfilms directly via electrodeposition from a semineutral iron sulfate solution is demonstrated. Using boron-reducer as the additive, the CoFe films become very soft with high magnetic moment. Typically, the film coercivity in the easy and hard axes is 6.5 and 2.5 Oersted, respectively, with a saturation polarization up to an average of 2.45 Tesla. Despite the softness, these shining and smooth films still display a high-anisotropic field of ~45 Oersted with permeability up to 104. This kind of films can potentially be used in current and future magnetic recording systems as well as microelectronic and biotechnological devices.Baoyu Zong, Guchang Han, Jinjun Qiu, Zaibing Guo, Li Wang, Wee-Kay Yeo, and Bo Liu© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/504917.htmlA theoretical study to investigate homogenization of mutually immiscible polymers using nanoscale effects has been performed. Specifically, the miscibility behavior of all-polymer nanocomposites composed of linear-polystyrene (PS) chains and individual cross-linked poly(methyl methacrylate)-nanoparticles (PMMA-NPs) has been predicted. By using a mean field theory accounting for combinatorial interaction energy and nanoparticle-driven effects, phase diagrams were constructed as a function of PMMA-NP size, PS molecular weight, and temperature. Interestingly, complete miscibility (i.e., homogeneity) was predicted from room temperature to 675 K for PMMA-nanoparticles with radius less than ~7 nm blended with PS chains (molecular weight 150 kDa, nanoparticle volume fraction 20%) in spite of the well-known immiscibility between PS and PMMA. Several nanoscale effects affecting miscibility in PMMA-NP/PS nanocomposites involving small PMMA-nanoparticles are discussed.Sarah Montes, Agustín Etxeberria, Javier Rodriguez, and Jose A. Pomposo© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/346545.htmlThis research work concerns the hydriding reaction of LaNi5 during the first hydriding cycles (activation process). Step-by-step sorption isotherms (Δ[H/M]≈0.03) were measured at 298 K, in the composition range 0<H/M<2.0, at the beginning (first hydriding cycle, where hysteresis is maximum) and at the end (tenth hydriding cycle, where hysteresis is minimum) of the activation process, offering the possibility to correlate thermodynamic states (pressure-composition data points) to sorption kinetics. Using pneumatochemical impedance spectroscopy (PIS), experimental impedance diagrams were obtained for each data point of the isotherms. Microscopic rate parameters such as surface resistance and hydrogen diffusion coefficient were obtained as a function of composition, by fitting appropriate model equations to experimental impedances. It is found that the high-frequency pneumatochemical resistance significantly decreases during activation. This is correlated with the surface increase of the solid-gas interface area. The hydrogen diffusion coefficient is found to be larger at the beginning of the activation process and lower on a fully activated sample.P. Millet, C. Lebouin, R. Ngameni, A. Ranjbari, and M. Guymont© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/726285.htmlColloidal gold particles with uniform size distributions were fabricated utilizing human red blood cells (RBCs) as templates. The gold shells were charged with a metal chelating agent to prevent flocculation. The procedure described here allows control over the shape of the colloidal particles. Thus, it was possible to fabricate discs and spheres by controlling the osmotic pressure.Preston B. Landon, Jose J. Gutierrez, Sara A. Alvarado, Sujatha Peela, Srinivasan Ramachandran, Fernando Teran Arce, and Ratnesh Lal© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/760650.htmlSilicon carbide (SiC) films were prepared by single and dual-ion-beam sputtering deposition at room temperature. An assisted Ar+ ion beam (ion energy Ei = 150 eV) was directed to bombard the substrate surface to be helpful for forming SiC films. The microstructure and optical properties of nonirradicated and assisted ion-beam irradicated films have been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectra. TEM result shows that the films are amorphous. The films exposed to a low-energy assisted ion-beam irradicated during sputtering from a-SiC target have exhibited smoother and compacter surface topography than which deposited with nonirradicated. The ion-beam irradicated improves the adhesion between film and substrate and releases the stress between film and substrate. With assisted ion-beam irradicated, the density of the Si–C bond in the film has increased. At the same time, the excess C atoms or the size of the sp2 bonded clusters reduces, and the a-Si phase decreases. These results indicate that the composition of the film is mainly Si–C bond.C. G. Jin, X. M. Wu, and L. J. Zhuge© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/314898.htmlThe photochromism of [7′-hydroxy-8′-formyl-3-methyl-4-oxospiro[1,3-benzoxazin-2,2′-[2H-1]benzopyran],SP(I),[7′-hydroxy-8′-formyl-3-benzyl-4-oxospiro[1,3-benzoxazin-2,2′-[2H-1]benzopyran] SP(II) and their coordination with Tb3+and Sm3+ ions have been studied in DMF. UV/vis induced-color development due to heterolytic bond cleavage of SP(I) and SP(II) is greatly influenced by complexation with the lanthanide ions. The irradiation-induced color enhancement due to ring opening and thermal decoloration of the open forms of SP(I), SP(II) follows first-order kinetics. Physical characteristics of the studied systems such as colorability and relaxation time of thermal bleaching parameters were determined. Moreover, light-energy transfer-induced luminescence of lanthanide ions via coordination with the two spirobenzoxazines was monitored.Esam Bakeir, G. M. Attia, Maria Lukyanova, Boris Lukyanov, and M. S. A. Abdel-Mottaleb© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/671642.htmlAccelerated drug release has been achieved by means of the fast rotation of magnetic gel beads. The magnetic gel bead consists of sodium alginate crosslinked by calcium chlorides, which contains barium ferrite of ferrimagnetic particles, and ketoprofen as a drug. The bead underwent rotational motion in response to rotational magnetic fields. In the case of bead without rotation, the amount of drug release into a phosphate buffer solution obeyed non-Fickian diffusion. The spontaneous drug release reached a saturation value of 0.90 mg at 25 minutes, which corresponds to 92% of the perfect release. The drug release was accelerated with increasing the rotation speed. The shortest time achieving the perfect release was approximately 3 minutes, which corresponds to 1/8 of the case without rotation. Simultaneous with the fast release, the bead collapsed probably due to the strong water flow surrounding the bead. The beads with high elasticity were hard to collapse and the fast release was not observed. Hence, the fast release of ketoprofen is triggered by the collapse of beads. Photographs of the collapse of beads, time profiles of the drug release, and a pulsatile release modulated by magnetic fields were presented.Tetsu Mitsumata, Yusuke Kakiuchi, and Jun-Ichi Takimoto© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/810457.htmlA composited system was fabricated by coupling Pt/TiO2 with water-splitting catalyst for photooxidation of organic pollutants in aqueous solutions. The new composited system exhibits more efficient photocatalytic activity than pure Pt/TiO2 does under UV light irradiation. The promoting effect is dependent on the photo-produced H2 over the composited system. The active oxygen species, hydroxyl radical (·OH) and hydrogen peroxide (H2O2), are measured by fluorescence spectroscopy and photometric method, respectively. The results reveal that the produced H2 by photocatalytic water splitting over NiO/NaTaO3:La transfers to Pt particle of TiO2 surface, then reacts with introducing O2 to generate in situ intermediate H2O2, and finally translates into ·OH radical to accelerate the photooxidation of organic pollutants.Zizhong Zhang, Xuxu Wang, Jinlin Long, Xianliang Fu, Zhengxin Ding, Zhaohui Li, Ling Wu, and Xianzhi Fu© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2008/169247.htmlThe physical interaction between 2 substances frequently occurs along the mixing and manufacturing of solid drug dosage forms. The physical interaction is generally based on coarrangement of crystal lattice of drug combination. The cold contact method has been developed as a simple technique to detect physical interaction between 2 drugs. This method is performed by observing new habits of cocrystal that appear on contact area of crystallization by polarization microscope and characterize this cocrystal behavior by melting point determination. Has been evaluated by DSC, this method is proved suitable to identify eutecticum interaction of pseudoephedrine HCl-acetaminophen, peritecticum interaction of methampyrone-phenylbutazon, and solid solution interaction of amoxicillin-clavulanate, respectively.Ilma Nugrahani, Sukmadjaja Asyarie, Sundani Nurono Soewandhi, and Slamet Ibrahim© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2007/018278.abs.htmlThis work reports the use of benzophenone, a very well characterized probe, to study new hosts (i.e., modified celluloses grafted with alkyl chains bearing 12 carbon atoms) by surface esterification. Laser-induced room temperature luminescence of air-equilibrated or argon-purged solid powdered samples of benzophenone adsorbed onto the two modified celluloses, which will be named C12-1500 and C12-1700, revealed the existence of a vibrationally structured phosphorescence emission of benzophenone in the case where ethanol was used for sample preparation, while a nonstructured emission of benzophenone exists when water was used instead of ethanol. The decay times of the benzophenone emission vary greatly with the solvent used for sample preparation and do not change with the alkylation degree in the range of 1500–1700 micromoles of alkyl chains per gram of cellulose. When water was used as a solvent for sample preparation, the shortest lifetime for the benzophenone emission was observed; this result is similar to the case of benzophenone adsorbed onto the “normal” microcrystalline cellulose surface, with this latter case previously reported by Vieira Ferreira et al. in 1995. This is due to the more efficient hydrogen abstraction reaction from the glycoside rings of cellulose when compared with hydrogen abstraction from the alkyl chains of the modified celluloses. Triplet-triplet transient absorption of benzophenone was obtained in both cases and is the predominant absorption immediately after laser pulse, while benzophenone ketyl radical formation occurs in a microsecond time scale both for normal and modified celluloses.L. F. Vieira Ferreira, A. I. Costa, I. Ferreira Machado, T. J. F. Branco, S. Boufi, M. Rei-Vilar, and A. M. Botelho do Rego© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2007/095753.abs.htmlDyed natural rubber (NR) and styrene butadiene rubber (SBR), designed for outdoor applications, were exposed to an accelerated artificial aging in xenon light. The aging results in the deterioration of the exposed surface material properties. The ability of dyed polymers to withstand prolonged sunlight exposure without fading or undergoing any physical deterioration is largely determined not only by the photochemical characteristics of the absorbing dyestuff itself but also by the polymer structure and fillers. Results obtained by laser mass spectrometry, UV-visible spectroscopy, and environmental scanning electron microscopy indicate that dyed filled NR and SBR samples behave differently during the photo-oxidation. The fading of the dyed polymers was found to be promoted in the NR sample. This can be correlated with LDI-FTICRMS results, which show the absence of [M-H]− orange pigment pseudomolecular ion and also its fragment ions after aging. This is confirmed by both EDX and UV/Vis spectroscopy. EDX analysis indicates a concentration of chlorine atoms, which can be considered as a marker of orange pigment or its degradation products, only at the surface of SBR flooring after aging. Reactivity of radicals formed during flooring aging has been studied and seems to greatly affect the behavior of such organic pigments.Junien Exposito, Claude Becker, David Ruch, and Frédéric Aubriet© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2007/085978.abs.htmlHigh-level ab-initio equation-of-motion coupled-cluster methods with singles, doubles, and noniterative triples are used, in conjunction with the combined quantum mechanical molecular mechanics approach, to investigate the structure of low-lying excited states of the guanine base in DNA and solvated environments. Our results indicate that while the excitation energy of the first excited state is barely changed compared to its gas-phase counterpart, the excitation energy of the second excited state is blue-shifted by 0.24 eV.Karol Kowalski and Marat Valiev© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2007/060623.abs.htmlPsoralen interaction with two models of DNA was investigated using molecular mechanics and molecular dynamics methods. Calculated energies of minor groove binding and intercalation were compared in order to define a preferred binding mode for the ligand. We found that both binding modes are possible, explaining the low efficiency for monoadduct formation from intercalated ligands. A comparison between the interaction energy for intercalation between different base pairs suggests that the observed sequence selectivity is due to favorable intercalation in 5′-TpA in (AT)n sequences.Patricia Saenz-Méndez, Rita C. Guedes, Daniel J. V. A. dos Santos, and Leif A. Eriksson© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/apc/2007/082901.abs.htmlThe kinetics of paracetamol oxidation are first order each in [paracetamol] and [HClO4]. The kinetic study shows that the oxidation proceeds in two steps. The effects of anionic micelles of sodiumdodecyl sulphate (SDS) and complexing agents (ethylenediammine tetraacetic acid (EDTA) and 2,2′-bipyridyl (bpy)) were also studied. Fast kinetic spectrophotometric method has been described for the determination of paracetamol. The method is based on the catalytic effect of manganese(II) on the oxidation of paracetamol by chromium(VI) in the presence of HClO4 (= 0.23 mol dm−3). Optimum reaction time is 4 to 6 minutes at a temperature of 30∘C. The addition of manganese(II) ions largely decreased the absorbance of chromium(VI) at 350 nm. This reaction can be utilized for the determination of paracetamol in drugs.Mohammed Ilyas, Maqsood Ahmad Malik, Syed Misbah Zahoor Andrabi, and Zaheer Khan© 2010, Hindawi Publishing Corporation. All rights reserved.