bluuebunny/crossref_metadata_2025_split huggingface dataset:
A proteomic approach in analyzing heat‐responsive proteins in rice leaves
Authors: Lee Dong‐Gi , Ahsan Nagib , Lee Sang‐Hoon , Kang Kyu Young , Bahk Jeong Dong , Lee In‐Jung , Lee Byung‐Hyun 
Published: August 2007

AbstractThe present study investigated rice leaf proteome in response to heat stress. Rice seedlings were subjected to a temperature of 42°C and samples were collected 12 and 24 h after treatment. Increased relative ion leakage and lipid peroxidation suggested that oxidative stress frequently was generated in rice leaves exposed to high temperature. 2‐DE, coupled with MS, was used to investigate and identify heat‐responsive proteins in rice leaves. In order to identify the low‐abundant proteins in leaves, samples were prefractionated by 15% PEG. The PEG supernatant and the pellet fraction samples were separated by 2‐DE, and visualized by silver or CBB staining. Approximately 1000 protein spots were reproducibly detected on each gel, wherein 73 protein spots were differentially expressed at least at one time point. Of these differentially expressed proteins, a total of 34 and 39 protein spots were found in the PEG supernatant and pellet fractions, respectively. Using MALDI‐TOF MS, a total of 48 proteins were identified. These proteins were categorized into classes related to heat shock proteins, energy and metabolism, redox homeostasis, and regulatory proteins. The results of the present study show that a group of low molecular small heat shock proteins (sHSPs) were newly induced by heat stress. Among these sHSPs, a low molecular weight mitochondrial (Mt) sHSP was validated further by Western blot analysis. Furthermore, four differentially accumulated proteins that correspond to antioxidant enzymes were analyzed at the mRNA level, which confirmed the differential gene expression levels, and revealed that transcription levels were not completely concomitant with translation. The identification of some novel proteins in the heat stress response provides new insights that can lead to a better understanding of the molecular basis of heat‐sensitivity in plants.
Circadian proteomics of the mouse retina
Authors: Tsuji Takahiro , Hirota Tsuyoshi , Takemori Nobuaki , Komori Naoka , Yoshitane Hikari , Fukuda Masafumi , Matsumoto Hiroyuki , Fukada Yoshitaka 
Published: August 2007

AbstractThe circadian clock in the retina regulates a variety of physiological phenomena such as disc shedding and melatonin release. Although these events are critical for retinal functions, it is almost unknown how the circadian clock controls the physiological rhythmicity. To gain insight into the processes, we performed a proteomic analysis using 2‐DE to find proteins whose levels show circadian changes. Among 415 retinal protein spots, 11 protein spots showed circadian rhythmicity in their intensities. We performed MALDI‐TOF MS and NanoLC‐MS/MS analyses and identified proteins contained in the 11 spots. The proteins were related to vesicular transport, calcium‐binding, protein degradation, metabolism, RNA‐binding, and protein foldings, suggesting the clock‐regulation of neurotransmitter release, transportation of the membrane proteins, calcium‐binding capability, and so on. We also found a rhythmic phosphorylation of N‐ethylmaleimide‐sensitive fusion protein and identified one of the amino acid residues modified by phosphorylation. These findings provide a new perspective on the relationship between the physiological functions of the retina and the circadian clock system.
The chicken egg white proteome
Authors: Mann Karlheinz 
Published: August 2007

AbstractUsing 1‐D PAGE and LC‐MS/MS and MS3 we identified 78 chicken egg white proteins, 54 of which were identified in egg white for the first time. All proteins were quantitated by calculating their exponentially modified protein abundance index (emPAI). Some previously known egg white components not characterized by amino acid sequences before, such as α‐2‐macroglobulin, were associated to a sequence for the first time. The predicted sequence was confirmed by MS‐sequenced peptides covering 42% of the entire sequence. α‐2‐Macroglobulin occurred in egg white at the same concentration as ovostatin with which it showed 35% identity. For other proteins, which were previously only characterized by partial sequences, such as β‐ovomucin or ovalbumin X, we identified and confirmed predicted complete sequences with a high coverage by MS‐sequenced peptides. New proteins included a 7 kDa protein consisting of a single secretoglobin sequence (ovosecretoglobin), a 7 kDa protein with similarity to black swan cygnin and turkey meleagrin (gallin) and proteins involved in binding, modification, and possibly detoxification, of bacterial lipopolysaccaride. The list of egg white proteins provided is by far the most comprehensive at present and is intended to serve as a starting point for the isolation and functional characterization of interesting new proteins.
Mechanistic understanding of the photochromism of a hybrid dithienylethene–naphthopyran system by NMR spectroscopy
Authors: Delbaere S. , Micheau J‐C. , Frigoli M. , Mehl G. H. , Vermeersch G. 
Published: August 2007

AbstractDetailed 1H NMR kinetic investigations of the photochemical and thermal behaviour of a recently described poly‐photochromic molecule including both dithienylethene and naphthopyran groups are reported. The combination of two photochromic moieties allows the selective controlled extension of the conjugated pi‐electron system and the modulation of the absorption behaviour between ∼380 to ∼750 nm. It is shown that the two photochromic entities are coupled and do not behave independently. Copyright © 2007 John Wiley & Sons, Ltd.
New photochromic bisthienylethene derivatives containing carbazole
Authors: Feng Yanli , Shen Wei , Huang Wei , Tan Wenjuan , Lu Changgui , Cui Yiping , Tian He 
Published: August 2007

AbstractSome new photochromic bisthienylethene (BTE) derivatives containing carbazole were synthesized by Suzuki coupling method. All compounds were characterized by 1H NMR spectra, 13C NMR, mass spectra, etc. Their optical, photochromic, and electrochemical properties were described. Moreover, their two‐photon absorption (TPA) properties were investigated both in open and closed forms, finding observable distinction in the TPA of the ring‐open and ring‐closed forms. These compounds could be used as two‐photon switches and for the potential applications in three‐dimensional optical storage. Copyright © 2007 John Wiley & Sons, Ltd.
Joint theoretical and experimental study of the gas‐phase elimination kinetics of tert‐butyl ester of carbamic, N, N‐dimethylcarbamic, N‐hydroxycarbamic acids and 1‐(tert‐butoxycarbonyl)‐imidazole
Authors: Mora Jose R , Tosta María , Domínguez Rosa M. , Herize Armando , Barroso Jenny , Córdova Tania , Chuchani Gabriel 
Published: August 2007

AbstractThe gas‐phase elimination kinetics of the title compounds were carried out in a static reaction system and seasoned with allyl bromide. The working temperature and pressure ranges were 200–280 °C and 22–201.5 Torr, respectively. The reactions are homogeneous, unimolecular, and follow a first‐order rate law. These substrates produce isobutene and corresponding carbamic acid in the rate‐determining step. The unstable carbamic acid intermediate rapidly decarboxylates through a four‐membered cyclic transition state (TS) to give the corresponding organic nitrogen compound. The temperature dependence of the rate coefficients is expressed by the following Arrhenius equations: for tert‐butyl carbamate logk1 (s−1) = (13.02 ± 0.46) – (161.6 ± 4.7) kJ/mol(2.303 RT)−1, for tert‐butyl N‐hydroxycarbamate logk1 (s−1) = (12.52 ± 0.11) – (147.8 ± 1.1) kJ/mol(2.303 RT)−1, and for 1‐(tert‐butoxycarbonyl)‐imidazole logk1 (s−1) = (11.63 ± 0.21)–(134.9 ± 2.0) kJ/mol(2.303 RT)−1. Theoretical studies of these elimination were performed at Møller–Plesset MP2/6‐31G and DFT B3LYP/6‐31G(d), B3LYP/6‐31G(d,p) levels of theory. The calculated bond orders, NBO charges, and synchronicity (Sy) indicate that these reactions are concerted, slightly asynchronous, and proceed through a six‐membered cyclic TS type. Results for estimated kinetic and thermodynamic parameters are discussed in terms of the proposed reaction mechanism and TS structure. Copyright © 2007 John Wiley & Sons, Ltd.
Gas phase interaction of L‐proline with Be2+, Mg2+ and Ca2+ ions: a computational study
Authors: Fleming G. J. , McGill P. R. , Idriss H. 
Published: August 2007

AbstractGeometry optimisation and metal ion affinities (MIAs) of the binding configurations of Be2+, Mg2+ and Ca2+ to L‐proline were calculated using the hybrid Density Functional Theory (DFT‐B3LYP) and second order Møllet−Plesset perturbation theory (MP2) methods. Be2+ was found to bind preferentially in a charge transfer type arrangement through the carbonyl oxygen (CO) and the lone pair of the imino‐group nitrogen atom (NH). On the contrary Mg2+ and Ca2+ were found to prefer binding in a bi‐dentate manner through the carboxylate group of L‐proline (OCO) in a zwitterion form. The main types of interactions found to influence the binding preference of M2+ ions to L‐proline were (i) charge transfer in the case of Be2+ ions and (ii) electrostatic interactions in the case of Mg2+ and Ca2+ ions. Inspection of the IR stretching of the NH and the OH groups of L‐proline with M2+ ions in a chelating configuration (to both O and N atoms) indicated a considerable shift to higher frequency with decreasing MIA. On the other hand, the MIA for the zwitterion L‐proline with M2+ tracks the reciprocal distance of the M2+OCO bond further confirming that the nature of the bond is mainly electrostatic. Comparison with other molecules containing the carboxylic function is also included in order to gain more insight on the types of interaction of this amino acid with metal ions in general. Copyright © 2007 John Wiley & Sons, Ltd.
Mechanism of 4‐methyl‐1,2,4‐triazol‐3‐thiole reaction with formaldehyde. A DFT study
Authors: Wujec Monika , Paneth Piotr 
Published: August 2007

AbstractContrary to the typical nucleophilic substitution, occurring on the sulfur atom of 4‐methyl‐1,2,4‐ triazol‐3‐thiole, the reaction with formaldehyde leads to the formation of the NC bond rather than the SC bond. The mechanism of this reaction has been characterized theoretically. Calculations indicate that the reaction proceeds via a cyclic transition state involving one solvent molecule with the Gibbs free activation energy of only 2 kcal/mol. The alternative pathway that leads to the SC bond formation is about 5 kcal/mol more energetically demanding. Copyright © 2007 John Wiley & Sons, Ltd.
Relationship between basicity and nucleophilicity
Authors: Jaramillo Paula , Pérez Patricia , Fuentealba Patricio 
Published: August 2007

AbstractThe empirical concepts of basicity and nucleophilicity are related but not strictly proportional. Hence, the aim of this study is to help in elucidating the range where both concepts are directly proportional. To do this, the relationship between a recently introduced nucleophilicity index and the proton affinity (PA) of several families of bases has been studied. A good correlation between the PA and the nucleophilicity index using HF and HCN as electrophilic partner has been found. Our studies show that the correlation exists only when the interaction is soft–soft in character and for strong bases with weak acids. However, the relationship is not only valid for exothermic reactions as it has been previously postulated but also for endothermic reactions. Copyright © 2007 John Wiley & Sons, Ltd.
Morphology investigation on high‐pressure crystallized bisphenol‐A polycarbonate/dioctyl phthalate blends
Authors: Lu Jun , Huang Rui , Oh Il‐Kwon 
Published: August 2007

AbstractThe high‐pressure crystallized bisphenol‐A polycarbonate/dioctyl phthalate (BAPC/DOP) blend samples were investigated using wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The specimens were prepared in a piston‐cylinder high‐pressure apparatus by varying the temperature, the pressure and the crystallization time for a BAPC/DOP (90/10, wt/wt) blend. The other four specimens were also prepared with different weight ratios of BAPC/DOP. The DSC results showed that the amorphous BAPC could be crystallized in 45 min by the blending with DOP and the subsequent high‐pressure treatment. A wide variety of morphologies of BAPC crystals were disclosed by SEM, including spherulites, spatial dendrites, crystalbars, platelets and regular polygonal crystals of different characteristics. The folded‐chain lamellar crystals were found to be the substructures of these observed BAPC microstructures. The SEM revealed a granular substructure of the lamellae in a low‐crystallinity sample as well, which indicated that the crystallization of BAPC in the multiphase system might possibly agree with the model developed by Strobl. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2715–2728, 2007
Changes in electrical resistance of carbon‐black‐filled silicone rubber composite during compression
Authors: Ding Tianhuai , Wang Luheng , Wang Peng 
Published: August 2007

AbstractWe studied the changes in the electrical resistance of carbon black filled silicone rubber composite, which is the sensitive element of the flexible force sensor, as a function of time during compression. The experimental results show that there is a sudden increase of the electrical resistance along with the sudden increase of the stress immediately after the compression. When the sample strain is kept constant, the electrical resistance and the stress both decay with time. The data of the stress relaxation and the resistance relaxation both can be fitted by the linear combination of two exponential functions. Based on the shell structure theory, the experimental phenomena are explained from the view that the uniaxial pressure induces the changes in the effective conductive paths. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2700–2706, 2007
Dielectric and thermal characterization of low density ethylene/10‐undecen‐1‐ol copolymers prepared with nickel catalysts
Authors: Viciosa M. Teresa , Rodrigues Carla , Fernández Susete , Matos Inês , Marques Maria M. , Duarte M. Teresa , Mano João F. , Dionísio Madalena 
Published: August 2007

AbstractEthylene and 10‐undecen‐1‐ol copolymers, prepared using a nickel complex as catalyst, were studied using differential scanning calorimetry (DSC), X‐ray diffraction, and dielectric relaxation spectroscopy. The behavior exhibited by copolymers containing incorporated 10‐undecen‐1‐ol amounts within 0.5 and 4.6 mol % was compared with neat polyethylene. DSC revealed that a new crystalline region with lower thickness lamellae emerges in copolymers due to the side‐chains crystallization. Nevertheless, the global crystallization degree decreases due to the loss of crystallinity that occurs in a greater extent in PE‐like regions. Dielectric relaxation spectroscopy detected two processes, a low activation energy process below −20 °C related with localized mobility increasing in intensity and deviating to higher temperatures with the increase in 10‐undecen‐1‐ol amount, and a high activation energy process ascribed to the glass transition, located at higher temperatures for the different copolymers relatively to neat polyethylene. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2802–2812, 2007
Crystal forms and ferroelectric properties of poly(vinylidene fluoride)/polyamide 11 blends prepared by high‐shear processing
Authors: Li Yongjin , Shimizu Hiroshi , Furumichi Toshiaki , Takahashi Yoshiyuki , Furukawa Takeo 
Published: August 2007

AbstractNanostructured poly(vinylidene fluoride) (PVDF)/polyamide 11 (PA11) blends have been melt‐processed using a high‐shear extruder. Uniaxially oriented blended films were fabricated by hot rolling to prepare ferroelectic films. The effects of rolling temperature and draw ratio on the crystal forms of both PVDF and PA 11 were investigated by means of Fourier transform infrared spectra (FTIR) and wide‐angle X‐ray diffraction (WAXD). It was shown that hot rolling in the range of 25–110 °C results in the crystal form transformation from the nonpolar α‐form into the polar β‐form for PVDF. The content and orientation function of β‐crystallites are strongly dependent upon the rolling temperature and the draw ratio. The highest content of well‐oriented β‐crystallites was achieved with a draw ratio of 4.0 upon rolling at 80 °C. At the same time, the content of the α‐form of PA11 in the blend was also found to decrease by hot rolling. The ferroelectric properties (D‐E hysteresis) of the oriented blended films were measured. The remanent polarization of the PVDF/PA11 = 90/10 blend is as high as 91 mC/m2, which is about 1.2 times higher than that of pure PVDF. The D‐E hysteresis curves and the temperature dependence of the piezoelectric stress coefficients of the high‐shear‐processed sample suggested that the formation of nano‐dispersed structures resulted in the improvement of the remanent polarization and thermal characteristics at a temperature higher than 80 °C. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2707–2714, 2007
Waterborne trifunctionalsilane‐terminated polyurethane nanocomposite with silane‐modified clay
Authors: Subramani Sankaraiah , Lee Jun‐Young , Choi Sung‐Wook , Kim Jung Hyun 
Published: August 2007

AbstractTrifunctional organosilane‐modified clay was synthesized and used to prepare waterborne trifunctionalsilane‐terminated polyurethane (WSPU)/clay nanocomposite dispersions in this study. Qualitative evidence of the presence of chemically attached silane molecules on clay were confirmed by Fourier transform infrared spectroscopy. The grafted amount and the grafting yield were determined by thermogravimetric analysis and the obtained results were in good agreement with the cation exchange capacity of pristine clay. X‐ray diffraction and transmission electron microscopy examinations indicated that the clay platelets are mostly intercalated or partially exfoliated in the SPU matrix with a d‐spacing of ∼2.50 nm. Clay does not influence the location and peak broadness of the glass transition temperature of soft segment as well as hard segment domains in the WSPU/clay films. WSPU/clay dispersion with higher clay content exhibits a marginal increase in the average particle size, but silane modified clay has a pronounced effect compared with Cloisite 20A‐based nanocomposites. In addition, the incorporation of organophilic clay can also enhance the thermal resistance and tensile properties of WSPUs dramatically through the reinforcing effect. The improvement in water and xylene resistance of the silane modified clay nanocomposites proved that trifunctional organosilane can be used as effective modifiers for clays. Storage stability results confirmed that the prepared nanocomposite dispersions were stable. This method provides an efficient way to incorporate silane modified clay in SPU matrix. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2747–2761, 2007
A simple approach to determine the equilibrium shape and position of sandwiched polymer droplets
Authors: Hyun Dong Choon , Jeong Unyong , Ryu Du Yeol 
Published: August 2007

AbstractThe thermodynamic shape and position of a polymer drop sandwiched between two polymer melt plates were predicted by simulating the change of the interfacial energy according to various shapes and position of the drop. The calculation results were in a precise coincidence with the experimental results exhibiting lens, spreading, and encapsulation. The simple formula and easy concept of the calculation can be useful to predict the morphology of immiscible ternary blends with the information of the interfacial tensions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2729–2738, 2007
Structure and gas permeability of asymmetric polyimide membranes made by dry–wet phase inversion: Influence of alcohol as casting solution
Authors: Mikawa Masato , Seki Naoko , Nagaoka Shoji , Kawakami Hiroyoshi 
Published: August 2007

AbstractIn this article, we have reported the influence of alcohol as a casting solution on the structure and the gas permeability of asymmetric polyimide membranes made by dry–wet phase inversion. The apparent skin layer thickness of the asymmetric membrane decreased with an increase in molecular weight of the alcohol, and the thicknesses of the membranes made from methanol, ethanol, propanol, and butanol were 250, 120, 61, and 31 nm, respectively. We found that χ12 as an interaction parameter of solvent–nonsolvent had a significant influence on the phase inversion occurring in the coagulant medium. On the other hand, the gas permeance and the gas selectivity in the asymmetric membranes increased with the increasing molecular weight of the alcohol. We believe that a more packed structure formed in the asymmetric polyimide membrane with a thinner surface skin layer is also responsible for the thickness‐dependence of the gas selectivity obtained in this study. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2739–2746, 2007
Chemotherapy‐induced alopecia and effects on quality of life among women with breast cancer: a literature review
Authors: Lemieux Julie , Maunsell Elizabeth , Provencher Louise 
Published: August 2007

AbstractBackground: Alopecia is a common side effect of chemotherapies used in the treatment of breast cancer. The aim of this review is to describe the effects of alopecia on quality of life (QOL) in this population.Methods: We conducted a literature review using Medline, Embase, Cumulative Index to Nursing and Allied Health Literature and PsycInfo databases. We searched for studies on the effects of alopecia on various aspects of QOL in breast cancer patients including anxiety and distress, body image, sexuality, self‐esteem, social functioning, global QOL and return to work outcomes.Results: A total of 38 articles were included in the review. Hair loss consistently ranked amongst the most troublesome side effects, was described as distressing, and may affect the body image.Conclusions: We found very little quantitative data on other aspects of QOL. More research is needed to determine the presence and extent of negative effects on chemotherapy‐induced alopecia on various aspects of QOL. Copyright © 2007 John Wiley & Sons, Ltd.