bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isothermal crystallization behavior of poly(L‐lactic acid)/organo‐montmorillonite nanocomposites
Authors: Li Xiaoxiu , Yin Jingbo , Yu Zhenyang , Yan Shifeng , Lu Xiaochun , Wang Yinjie , Cao Bin , Chen Xuesi 
Published: October 2008

AbstractThe isothermal crystallization behavior of poly(L‐lactic acid)/organo‐montmorillonite nanocomposites (PLLA/OMMT) with different content of OMMT, using a kind of twice‐functionalized organoclay (TFC), prepared by melt intercalation process has been investigated by optical depolarizer. In isothermal crystallization from melt, the induction periods (ti) and half times for overall PLLA crystallization (100°C ≤ Tc ≤ 120°C) were affected by the temperature and the content of TFC in nanocomposites. The kinetic of isothermal crystallization of PLLA/TFC nanocomposites was studied by Avrami theory. Also, polarized optical photomicrographs supplied a direct way to know the role of TFC in PLLA isothermal crystallization process. Wide angle X‐ray diffraction (WAXD) patterns showed the nanostructure of PLLA/TFC material, and the PLLA crystalline integrality was changed as the presence of TFC. Adding TFC led to the decrease of equilibrium melting point of nanocomposites, indicating that the layered structure of clay restricted the full formation of crystalline structure of polymer. The specific interaction between PLLA and TFC was characterized by the Flory‐Huggins interaction parameter (B), which was determined by the equilibrium melting point depression of nanocomposites. The final values of B showed that PLLA was more compatible with TFC than normal OMMT. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Preparation and characterization of cellulose fiber/chitosan composites
Authors: Wang Zhengke , Hu Qiaoling , Dai Xiaoguang , Wu Hao , Wang Youxiang , Shen Jiacong 
Published: October 2008

AbstractCellulose fiber/chitosan biodegradable rod (CF/CS rod) with layer‐by‐layer structure, good mechanical properties, and excellent X‐ray developing capability was successfully constructed via in‐situ precipitated method. As the ratio of CF to CS was 0.2/20 (wt/wt), the bending strength and bending modulus arrived at 124.1 MPa and 4.3 GPa, respectively, were significantly improved compared with pure CS rod. TGA indicated that the thermal stability of CS rod could be enhanced by mixing with CF, but fiber and matrix are partially compatible. SEM made clear that fibers were randomly dispersed in the CS matrix to connect layers of CS rod that can endure stress. FTIR spectra illuminated that small amount of Schiff base was formed due to the chemical reaction between fibers and CS matrix, which could enhance the mechanical combining stress of the interface. Thus, CF/CS rod has great potential to be used as internal fixation of bone fracture. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Poly(1,3‐butylene adipate) plasticized poly(lactic acid)/carbon black as electrical conductive polymer composites
Authors: Zhijun Qiao , Xingxiang Zhang , Ning Wang , Jianming Fang 
Published: October 2008

AbstractPoly(1,3‐butylene adipate) (PBA) as the plasticizer for poly(lactic acid) (PLA) and carbon black (CB) as conductive filler, electrically conductive polymer composites (CPC) with different CB and PBA contents were prepared. Fourier transform infrared revealed that the interaction existed between PLA/PBA matrix and CB filler, and PBA could improve this interaction. The rheology showed that CB could obviously improve the apparent viscosity and decrease the fluidity of the composites, but just the reverse for PBA. PLA/PBA/CB composites exhibited the low electrical percolation thresholds of 0.516, 1.20, 2.46, and 2.74 vol% CB at 30, 20, 10, and 0 wt% PBA. The conductivity of the composite containing 3.98 vol% CB and 30 wt% PBA reached 1.67 S/cm. Scanning electron microscopy revealed that the addition of PBA facilitated the dispersion of PLA/CB composites. PBA could dramatically increase the elongation at break of plasticized PLA. But high‐PBA content caused the lowering of tensile strength. With the increasing of CB contents, the enforcement effect on the plasticized PLA became more obvious. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Profiling humoral immune responses to P. falciparum infection with protein microarrays
Authors: Doolan Denise L. , Mu Yunxiang , Unal Berkay , Sundaresh Suman , Hirst Siddiqua , Valdez Conrad , Randall Arlo , Molina Douglas , Liang Xiaowu , Freilich Daniel A. , Oloo J. Aggrey , Blair Peter L. , Aguiar Joao C. , Baldi Pierre , Davies D. Huw , Felgner Philip L. 
Published: October 2008

AbstractA complete description of the serological response following exposure of humans to complex pathogens is lacking and approaches suitable for accomplishing this are limited. Here we report, using malaria as a model, a method which elucidates the profile of antibodies that develop after natural or experimental infection or after vaccination with attenuated organisms, and which identifies immunoreactive antigens of interest for vaccine development or other applications. Expression vectors encoding 250 Plasmodium falciparum (Pf) proteins were generated by PCR/recombination cloning; the proteins were individually expressed with >90% efficiency in Escherichia coli cell‐free in vitro transcription and translation reactions, and printed directly without purification onto microarray slides. The protein microarrays were probed with human sera from one of four groups which differed in immune status: sterile immunity or no immunity against experimental challenge following vaccination with radiation‐attenuated Pf sporozoites, partial immunity acquired by natural exposure, and no previous exposure to Pf. Overall, 72 highly reactive Pf antigens were identified. Proteomic features associated with immunoreactivity were identified. Importantly, antibody profiles were distinct for each donor group. Information obtained from such analyses will facilitate identifying antigens for vaccine development, dissecting the molecular basis of immunity, monitoring the outcome of whole‐organism vaccine trials, and identifying immune correlates of protection.
A novel solid phase‐ and chemical crosslinking‐based technology for determining protein localization in biological supramolecules
Authors: Horng Wei‐Cheng , Yen Yuan‐Hun , Chang Yen‐Chung 
Published: October 2008

AbstractA solid phase‐ and chemical crosslinking‐based technology was developed for determining the depths at which various protein constituents reside in a supramolecule. The usefulness of this technology was verified by trials using a synthetic three‐protein complex on glass coverslips. This technology was further applied to investigate the localization of seven major protein components in the postsynaptic density, a landmark supramolecule of the excitatory synapses in mammalian brains. The technology reported here will supplement the already powerful proteomic methodologies in studying the structure/function relationships of supramolecules.
Proteins modulation in human skeletal muscle in the early phase of adaptation to hypobaric hypoxia
Authors: Viganò Agnese , Ripamonti Marilena , De Palma Sara , Capitanio Daniele , Vasso Michele , Wait Robin , Lundby Carsten , Cerretelli Paolo , Gelfi Cecilia 
Published: October 2008

AbstractHigh altitude hypoxia is a paraphysiological condition triggering redox status disturbances of cell organization leading, via oxidative stress, to proteins, lipids, and DNA damage. In man, skeletal muscle, after prolonged exposure to hypoxia, undergoes mass reduction and alterations at the cellular level featuring a reduction of mitochondrial volume density, accumulation of lipofuscin, a product of lipid peroxidation, and dysregulation of enzymes whose time course is unknown. The effects of 7–9 days exposure to 4559 m (Margherita Hut, Monte Rosa, Italy) on the muscle proteins pattern were investigated, pre‐ and post‐exposure, in ten young subjects, by 2‐D DIGE and MS. Ten milligram biopsies were obtained from the mid part of the vastus lateralis muscle at sea level (control) and at altitude, after 7–9 days hypoxia. Differential analysis indicates that proteins involved in iron transport, tricarboxylic acid (TCA) cycle, oxidative phosphorylation, and oxidative stress responses were significantly (p<0.05) decreased in hypoxia. Parenthetically, hypoxia markers such as hypoxia inducible factor 1 α (HIF‐1α) and pyruvate dehydrogenase kinase 1 (PDK1) were still at the pre‐hypoxia levels, whereas the mammalian target of rapamycin (mTOR), a marker of protein synthesis, was reduced.
Riboproteomic analysis of polypeptides interacting with the internal ribosome‐entry site element of foot‐and‐mouth disease viral RNA
Authors: Pacheco Almudena , Reigadas Sandrine , Martínez‐Salas Encarnación 
Published: October 2008

AbstractInitiation of translation driven by internal ribosome entry site (IRES) elements depends upon the structural organization of this mRNA region. Besides translation initiation factors (eIFs), auxiliary proteins can also affect IRES activity. With the aim to identify proteins interacting with two unrelated IRESs present in the genome of foot‐and‐mouth disease virus (FMDV) and hepatitis C virus (HCV) we have used a proteomic approach. This procedure allowed the identification of 21 RNA‐binding proteins interacting with discrete regions of the FMDV IRES, domains 3 and 5, and 16 interacting with domain III of the HCV IRES. In support of the binding specificity, the factors interacting with domain 3 differed from those interacting with domain 5, and included three poly(rC)‐binding protein (PCBP) members, besides proliferation‐associated 2G4 (PA2G4) and deleted‐azoospermia 1 (DAZ1) protein. Around 71% of the identified factors associated with the FMDV IRES differ from those interacting with the HCV IRES. The group of proteins interacting with the FMDV or the HCV IRES includes eIF4B and 5 subunits of eIF3, respectively, known to interact with each of these RNAs, validating the results of this approach. According to the function of the identified proteins, 55% are involved in translation control, whereas 35% play a role in different aspects of RNA lifespan. Compilation of factors preferentially associated with FMDV or HCV IRES provides a basis for examining the strategies used by IRESs to recruit the translation machinery.
Lethal and sublethal effects of chlorantraniliprole on three species of Rhagoletis fruit flies (Diptera: Tephritidae)
Authors: Teixeira Luís AF , Gut Larry J , Wise John C , Isaacs Rufus 
Published: October 2008

AbstractBACKGROUND: Chlorantraniliprole formulated as a 350 g kg−1 WG (Altacor 35WG) for management of apple maggot Rhagoletis pomonella (Walsh), blueberry maggot R. mendax Curran and cherry fruit fly R. cingulata (Loew) (Diptera: Tephritidae) was evaluated in laboratory assays and field trials.RESULTS: A tarsal contact toxicity bioassay showed that a surface residue of 500 mg L−1 of chlorantraniliprole caused significantly higher mortality of male and female flies of all species compared with a control. Male apple maggot and blueberry maggot mortality was significantly higher than that for females, but there was similar mortality of male and female cherry fruit flies. An ingestion toxicity bioassay showed that 500 mg L−1 of chlorantraniliprole in diet caused significantly higher mortality of male and female flies of all species than the control, but there were no significant differences among the sexes. Delayed egglaying by females that had ingested chlorantraniliprole was found, but there were no significant sublethal effects on either the number of eggs laid or the egg hatch. Field trials with apple maggot and cherry fruit fly showed that protection of fruit by chlorantraniliprole was comparable with that of standard broad‐spectrum insecticides.CONCLUSIONS: The present data indicate that chlorantraniliprole has suppressant activity against Rhagoletis fruit flies, preventing fruit infestation primarily through direct lethal effects. Copyright © 2008 Society of Chemical Industry
Mild oxide‐hydrothermal synthesis of different aspect ratios of monoclinic BiVO4 nanorods tuned by temperature
Authors: Dong Fengqiang , Wu Qingsheng , Ma Jie , Chen Yijun 
Published: October 2008

AbstractThe monoclinic scheelite BiVO4 nanocrystals were easily prepared via an oxide‐hydrothermal synthesis (OHS) method directly utilizing bulk‐phase materials of V2O5 and Bi2O3 as precursor. In the presence of PEG 4000, the reactions were performed in the mild temperature range from 130 °C to 200 °C. The products were characterized with FTIR, XRD, TEM and UV–vis DRS. These data clearly demonstrated that monoclinic scheelite structure BiVO4 could be synthesized by the feasible OHS route. The aspect ratios of nanorods were increased with the synthesized temperature. The as‐prepared BiVO4 showed high photocatalytic activity, which was demonstrated by degradation of methylene blue (MB) solution under visible‐light irradiation (λ > 420 nm). A growth mechanism of bismuth vanadate was proposed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adjustment of the selenium amount provided during formation of CuInSe2 thin films from the metallic precursors
Authors: López‐García J. , Guillén C. 
Published: October 2008

AbstractCuInSe2 (CIS) thin films were grown by selenization of sequentially evaporated Cu and In metallic precursors. The adjustment of the Selenium amount provided during the selenization process within a partially closed graphite box for film thicknesses between 0.5–2.5 μm was performed. We obtained CuInSe2 films with chalcopyrite structure and preferential orientation along the (112) direction plane. XRD patterns showed intense and narrow peaks that indicate high crystallinity corresponding to a Se amount between 120–180 mg. Direct band gap energy between 0.90–0.97 eV, depending on the Se amount and film thickness, and a high absorption coefficient (∼105 cm–1) were found. A slight improvement in the surface morphology for the optimum Se amount aforementioned was observed. The measured film resistivities varied from 0.1 Ω cm to 40 Ω cm. Thus, the structural, optical and morphological characteristics were dependent of the Se amount provided during the selenization process and after fitting of this selenium, an optimization of the CIS thin films properties and a saving of the Se consumption were achieved. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gelatin nanoparticle fabrication and optimization of the particle size
Authors: Jahanshahi M. , Sanati M. H. , Hajizadeh S. , Babaei Z. 
Published: October 2008

AbstractThe biotechnology industry has recently been demanding second generation of nanoparticle bioproducts such as viruses, plasmids, virus‐like particles and drug‐delivery assemblies (20–300 nm). The possibility of preparing uniform nanoparticles consisting of proteins such as gelatin followed by covalent linkage of avidin was investigated. Gelatin nanoparticles were prepared by two‐step desolvation. As a colloidal drug‐delivery system, the essential parameters in fabrication were optimized by the Taguchi design method. However, for characterizing the nanoparticles AFM and SEM were employed. By introducing 4 factors (temperature, gelatin concentration, agitation speed and the amount of acetone) in 4 levels to the software 16 experiments were carried out and the optimum condition was gained in 50 °C, 45 mg/ml gelatin concentration, 80 ml of acetone based on reduction of the size. The produced nanoparticles size was under 174 nm. The mechanistic of the optimum conditions for preparing protein nanoparticles as well as their characterization are discussed in detail. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ZnO nanowire field‐effect transistor as a UV photodetector; optimization for maximum sensitivity
Authors: Kim Woong , Chu Kyo Seon 
Published: October 2008

AbstractWe demonstrate that drain–source (Vds) and gate–source voltages (Vgs) of a zinc oxide nanowire (ZnO NW) field‐effect transistor (FET) can be optimized to increase UV photodetection sensitivity. Investigation of the relationship between the sensitivity and the applied voltages reveals that the photodetector is most sensitive when it operates (1) with highest on/off current ratio and (2) at the “bottom” of the subthreshold swing region. Our results can be broadly applied to maximize sensitivity of other FET‐based sensors and detectors. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoinduced dissociation of donor–acceptor pairs in non‐magnetic phase of organic charge‐transfer crystal of tetrathiafulvalene–tetrabromo‐1,4‐benzoquinone
Authors: Itoh Chihiro , Nakata Yasuharu 
Published: October 2008

AbstractWe have studied 532 nm laser‐induced changes in the infrared reflection of a charge‐transfer (CT) crystal of tetrathiafulvalene (TTF) and tetrabromo‐1,4‐benzoquinone (BA) at 4 K. The spectra of the fractional change (ΔR /R) were characterized by dips situated in proximity to the structures ascribed to the ag‐mode vibrations of TTF+ and BA– at low excitation intensity. However, the excitation above 0.2 W cm–2 gave structures characterized by the inverted shape of the ag‐mode structures, indicating that the laser excitation reduced the intensity of the ag‐mode structures. The appearance of the ag‐mode structures is associated with loss of the inversion centre of the crystal due to the dimerization of TTF+ and BA–; hence, the intensity reduction of the ag‐mode structures is ascribed to dissociation of TTF+‐BA– pairs. We found that ΔR /R increased super‐linearly with enhancing excitation intensity. The result suggests that the dissociation involves a multi‐quantum process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton Mott transition and quantum condensation in electron‐hole systems
Authors: Ogawa Tetsuo 
Published: October 2008

AbstractThis paper reviews recent progress of theoretical studies on the metal‐insulator transition and the quantum condensation in photoexcited states, the electron‐hole (eh) systems, which are modeled by the e‐h (two‐band) Hubbard model with both repulsive U and attractive U ′ on‐site interactions. We confine ourselves to a quasithermal‐equilibrium situation. First, we introduce the dynamical mean‐field theory (DMFT) applied to the metalinsulator transition (called the “exciton Mott transition”) of the high‐dimensional e‐h systems at zero and finite temperatures T.We determined the phase diagram of the e‐h Hubbard model and the first‐order exciton Mott transition line in the plane of the (U ′;U) or (U = U ′ T).We find two types of insulating phases: exciton‐like and biexciton‐like. At the Mott critical temperature such first‐order Mott transition disappears, and the crossover is observed above the critical temperature. Comparison with results by the slave‐boson mean‐field treatment is also made. Role of the inter‐site interaction is also discussed with the use of the extended DMFT. Second, we discuss the crossover between the exciton Bose‐Einstein condensation and the e‐h BCStype condensed state at low temperature using the selfconsistent t ‐matrix and local approximations within the framework of DMFT. We evaluate the transition temperature as a function of the interaction strength. Effects of repulsive on‐site interaction are analyzed. Third, for a one‐dimensional e‐h system, the bosonization and renormalization‐group techniques clarify that the most probable ground state is the insulating biexciton crystal, reflecting the e‐h backward scattering and the long‐range Coulomb interaction. The exciton Mott transition never occurs at zero temperature in one dimension. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton polaritons in bulk CuCl microcavities grown by vacuum deposition
Authors: Oohata Goro , Nishioka Takashi , Kim DaeGwi , Ishihara Hajime , Nakayama Masaaki 
Published: October 2008

AbstractWe demonstrate the realization of cavity polariton states in bulk CuCl microcavities. The CuCl microcavities made from a bulk CuCl layer and distributed Bragg reflectors consisting of PbF2 and PbBr2 layers prepared by vacuum deposition. Angle‐resolved reflectance spectra show the strong coupling characteristics of the excitons and photon mode; namely, the energies of reflectance structures exhibit incident‐angle dependence accompanying with an anticrossing behaviour peculiar to the cavity polaritons. From the phenomenological analysis with a 3×3 Hamiltonian of the cavity‐polariton modes originating from the Z3 exciton, Z1,2 exciton, and cavity photon, it has been revealed that the vacuum Rabi splitting energies in the λ‐thick CuCl active layer are 97 meV and 162 meV for the Z3 and Z1,2 excitons, respectively. We also indicate the potential to control the Rabi‐splitting energy by changing the active layer thickness. Furthermore, the spectral profile of reflectance is reasonably explained by calculations based on a theory of non‐local linear optical response. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Femtosecond time‐resolved reflection spectroscopy in Pr1–xCax MnO3 (x =0.37)
Authors: Peng Xianzhou , Okimoto Yoichi , Endo Masato , Sato Ken , Aizawa Takeshi , Onda Ken , Ishikawa Tadahiko , Koshihara Shin‐ya , Arima Taka‐hisa 
Published: October 2008

AbstractThe ultrafast dynamics of photoinduced phase transition (PIPT) in a crystal of Pr1–x Cax MnO3 (x = 0.37) has been studied by means of femtosecond time‐resolved spectroscopy. Just after photoirradiation of 1.58 eV light at 100 K, ultrafast change of reflectivity (ΔR/R) was observed within ∼1 ps utilizing the probe light of 0.5 eV due to the ferromagnetic metallic phase transition. While the fast component of ΔR/R gradually increases with increasing the excitation intensity, the slow component observed at the delay time of ∼1 ps shows unusual dependence on the excitation intensity. The signature of ΔR/R changes from negative to positive with the excitaiton power, which cannot be explained by the photo‐thermal heating effect. In addition, we investigated the temperature dependence of the ΔR/R at 0.5 eV and observed the sudden change of ΔR/R around TN, which indicates that the efficiency of PIPT is closely correlated with the ordering of spin and extra electron in Mn4+. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonadiabatic theory of excitons in wurtzite AlGaN/GaN quantum‐well heterostructures
Authors: Pokatilov Evghenii P. , Nika Denis L. , Fomin Vladimir M. , Devreese Jozef T. 
Published: October 2008

AbstractWe have theoretically studied exciton states and photoluminescence spectra of the strained wurtzite AlxGa1–xN/GaN quantum‐well heterostructures. The electron energy spectrum is found through numerical solving of the one‐band Schrödinger equation, while the hole and exciton energy spectra are determined from the Schrödinger equation with the non‐symmetrical 6‐band Hamiltonian, including deformational and spin‐orbit interaction. The oscillator forces are calculated and the exciton states are determined, which are active in the process of the optical absorption. Three quantitative conclusions are made in a good agreement with experiments for different values of x as concerns: (i) the red shift of the zero‐phonon photoluminescence (PL) peaks with increase of the quantum‐well width, (ii) the relative intensities of the zero‐phonon and one‐phonon PL peaks, found within the non‐adiabatic approach, and (iii) the values of the PL decay time as a function of the quantum‐well width. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)