bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoinduced Oxidation Reaction of Benzotrifluoride with OH Radical by the Laser Flash Method
Authors: ZHANG Ren‐Xi , YE Zhao‐Lian , SHEN Yan , DONG Wen‐Bo , HOU Hui‐Qi 
Published: January 2008

AbstractThe optical transient and kinetics characterizations of the transients formed in the reaction of OH with benzotrifluoride (BTF) were performed by a laser flash photolysis technique. The results indicated that the formation of π‐type adduct of C6H5(OH)CF3 was the major reaction channel, and the δ‐type adduct of C6H5CF3OH formation was an additional minor process in the oxidation reaction of BTF attacked by OH radicals yielded from the photolysis of H2O2. Addition of OH to the CF3 group led to the fluoride ion elimination to yield α,α‐difluorophenylcarbinol (C6H5CF2OH). Trifluoromethylphenol (HOC6H4CF3) of meta‐, para‐ and ortho‐substituted isomers resulted from the addition of OH to the BTF aromatic ring.
Approach to a Facile and Selective Benzyl‐Protection of Carbohydrates Based on Silyl Migration
Authors: WANG Wei , LI Xiao‐Liu , ZHANG Ping‐Zhu , CHEN Hua 
Published: January 2008

AbstractA convenient and selective benzyl protection of carbohydrates has been investigated on the basis of the silyl migration under the conventional benzylation conditions, developing a facile and short synthesis of methyl 2,3,6‐tri‐O‐benzyl‐α‐D‐glucopyranoside.
Nonisothermal Kinetics of the Solid‐Solid Phase Transitions in the Perovskite Type Layer Compounds (CnH2n+1NH3)2ZnCl4
Authors: WU Ke‐Zhong , LI Jian‐Ling , ZHANG Jian‐Jun , LIU Xiao‐Di 
Published: January 2008

AbstractNonisothermal kinetics of the solid‐solid phase transitions in the perovskite type layer compounds (CnH2n+1NH3)2ZnCl4 has been determined for the hydrocarbon chain length from even number 12 to 18 of carbon atoms. The activation energy Ea was calculated by the Kissinger and Ozawa methods from the curves of Differential Scanning Calorimetry (DSC) measurements at different heating rates. The results indicated that the values of Ea of the phase transitions decreased with increasing chain length and showed a linear dependence on the number of carbon atoms, which was caused by that the order and rigidity of the hydrocarbon chain were decreased with increasing the carbon atoms. The two methods are in agreement with each other. The reaction order n of all materials is one that remains constant independently of the heating rate.
C60‐Based Ebselen Derivative: Synthesis and Enhanced Protective Effect on Mouse Thymus Cells
Authors: LIU Xu‐Feng , GUAN Wen‐Chao , KE Wen‐Shan 
Published: January 2008

AbstractA C60‐based ebselen derivative 3 was synthesized through a Bingel cyclopropanation of C60 with the ebselen malonate 2. It was obtained in a three‐step synthesis starting from 2‐(chloroseleno)benzoyl chloride and 2‐(2‐aminoethoxy)ethanol, in a 42% yield (based on consumed C60). Its structure was characterized by 1H NMR, 13C NMR, IR, FAB‐MS, and elemental analyses techniques. To verify that the C60‐based ebselen derivative 3 had enhanced effect on viability of mouse thymus cells, the C60 derivative 4 and ebselen derivative 2 were selected to treat the mouse thymus cells using the same procedures as those with the C60‐based ebselen derivative 3. The result shows that MTT(OD) values of compound 3 treated groups (0.335±0.021) were all higher than those of compound 4 (0.283±0.031) and compound 2 (0.247±0.025) treated groups, indicating that the compound 3 has an advantage over compounds 2 and 4 in promoting the viability of the mouse thymus cell.
TDDFT Study of the Electronic Structure, Absorption and Emission Spectra of the Light Emitters of the Amazing Firefly Bioluminescence and Solvation Effects on the Spectra
Authors: REN Ai‐Min , GUO Jing‐Fu , FENG Ji‐Kang , ZOU Lu‐Yi , LI Zhong‐Wei , GODDARD John David 
Published: January 2008

AbstractThe ground and excited state properties of luciferin (LH2) and oxyluciferin (OxyLH2), the bioluminescent chemicals in the firefly, have been characterized using density functional theory (DFT) and time dependent DFT (TDDFT) methods. The effects of solvation on the electronic absorption and emission spectra of luciferin and oxyluciferin were predicted with a self‐consistent isodensity polarized continuum model of the solvent using TDDFT. The S0→S1 vertical excitation energies in the gas phase and in water were obtained. Optimizations of the excited state geometries permitted the first predictions of the fluorescence spectra for these biologically important molecules. Shifts in both of the absorption and emission spectra on proceeding from the gas phase to aqueous solution were also predicted.
Fluorescence Quenching Study on the Interaction of Some Schiff Base Complexes with Bovine Serum Albumin
Authors: MEI Ping , ZHANG Li‐Xi , LIU Yi , CAI Li‐Hua , HU Pei‐Zhi 
Published: January 2008

AbstractThe interaction of Schiff base ligand A and its three metal complexes [A‐Fe(II), A‐Cu(II), and A‐Zn(II)] with bovine serum albumin (BSA) was investigated using a tryptophan fluorescence quenching method. The Schiff base ligand A and its three metal complexes all showed quenching of BSA fluorescence in a Tris‐HCl buffer. Quenching constants were determined for quenching BSA by the Schiff base ligand A and its metal complexes in a Tris‐HCl buffer (pH=7.4) at different temperatures. The experimental results show that the dynamic quenching constant (KSV) was increased with increasing temperature, whereas the association constant (K) was decreased with the increase of temperature. The thermodynamic parameters ΔH, ΔG and ΔS at different temperatures were calculated. The ionic strength of the Tris‐HCl buffer had a great influence on the wavelength of maximum emission of BSA. Under low ionic strength, the emission spectra of BSA influenced by A‐Zn(II) had a small blue shift. Compared to A‐Zn(II), the emission spectra of BSA in the presence of the Schiff base ligand A and A‐Cu(II) had no significant λem shift. At high ionic strength, the emission spectra of BSA upon addition of the Schiff base A, A‐Fe(II), and A‐Zn(II) all had a red shift, but the emission spectra of BSA had λem shift neither at low ionic strength, nor at high ionic strength in the presence of A‐Cu(II). Furthermore, the temperature did not affect the λem shift of BSA emission spectra.
Aromaticity of All Possible C26N2 Isomers
Authors: TANG Ming‐Hui , ABLIKIM Kerim 
Published: January 2008

AbstractThe aromaticity of all possible heterofullerenes C26N2 and C28 based on Td symmetry has been studied by means of the topological resonance energy and percentage topological resonance energy methods. The relationship between the aromaticity of the C26N2 isomers and the sites where nitrogen atoms dope at the C28 cage has been discussed. The calculation results show that the most stable isomer of C26N2 derivatives is formed by nitrogen atoms doping at the two tetrahedral vertices. C26N2 isomers are more stable than C28, but the C26N22− isomers are less stable than C28 4−4. The effect of nitrogen substitution on C28 stability was investigated by the topological charge stabilization rule.
Fluorescence Nanoscopy with Optical Sectioning by Two‐Photon Induced Molecular Switching using Continuous‐Wave Lasers
Authors: Fölling Jonas , Belov Vladimir , Riedel D. , Schönle Andreas , Egner Alexander , Eggeling Christian , Bossi Mariano , Hell Stefan W. 
Published: January 2008

AbstractDuring the last decade far‐field fluorescence microscopy methods have evolved that have resolution far below the wavelength of light. To outperform the limiting role of diffraction, all these methods, in one way or another, switch the ability of a molecule to emit fluorescence. Here we present a novel rhodamine amide that can be photoswitched from a nonfluorescent to a fluorescent state by absorption of one or two photons from a continuous‐wave laser beam. This bright marker enables strict control of on/off switching and provides single‐molecule localization precision down to 15 nm in the focal plane. Two‐photon induced nonlinear photoswitching of this marker with continuous‐wave illumination offers optical sectioning with simple laser equipment. Future synthesis of similar compounds holds great promise for cost‐effective fluorescence nanoscopy with noninvasive optical sectioning.
Osteopontin is produced by mast cells and affects IgE‐mediated degranulation and migration of mast cells
Authors: Nagasaka Akiko , Matsue Hiroyuki , Matsushima Hironori , Aoki Rui , Nakamura Yuumi , Kambe Naotomo , Kon Shigeyuki , Uede Toshimitsu , Shimada Shinji 
Published: January 2008

AbstractOsteopontin (OPN), originally discovered in bone as an extracellular matrix protein, was identified in many cell types in the immune system, presumably being involved in many aspects of pathogenesis of inflammatory and immune diseases. Mast cells are also involved in such pathological aspects by secreting multiple mediators. However, it has not been determined whether mast cells produce OPN and whether it affects their function. To test this, we used murine fetal skin‐derived cultured mast cells (FSMC) and bone marrow‐derived cultured mast cells. We found that OPN was spontaneously produced by FSMC and inducible by ionomycin and FcϵRI aggregation in bone marrow‐derived cultured mast cells. In the presence of mast cell growth factors, FSMC were similarly generated from both OPN‐deficient (OPN–/–) and ‐sufficient (OPN+/+) mice without significant differences in yield, purity, granularity, and viability. Using OPN–/– FSMC, we found that recombinant OPN augmented IgE‐mediated degranulation and induced FSMC chemotaxis. Both effects were mediated by OPN receptors (i.e. CD44 and integrin αv). IgE‐mediated passive cutaneous anaphylaxis was significantly reduced in OPN–/– mice compared with OPN+/+ mice, indicating physiological relevance of OPN. These results indicate that OPN is a mast cell mediator, enhances mast cell responses to antigen, and thus may influence mast cell‐related pathological conditions.See accompanying commentary at http://dx.doi.org/10.1002/eji200738131
IL‐10 suppressor activity and ex vivo Tr1 cell function are impaired in multiple sclerosis
Authors: Martinez‐Forero Ivan , Garcia‐Munoz Ricardo , Martinez‐Pasamar Sara , Inoges Susana , Lopez‐Diaz de Cerio Ascensión , Palacios Ricardo , Sepulcre Jorge , Moreno Beatriz , Gonzalez Zaira , Fernandez‐Diez Begoña , Melero Ignacio , Bendandi Maurizio , Villoslada Pablo 
Published: January 2008

AbstractT regulatory cells type 1 (Tr1 cells) are excellent candidates for cell therapy in multiple sclerosis (MS). The aim of our study was to assess the functional state of Tr1 cells and IL‐10R signaling in patients with MS. Tr1 cells were induced in vitro by activation with anti‐CD46 antibodies in controls and patients with MS. Cells were phenotyped by cytometry and suppression assays, and the expression of cytokines and transcription factors was evaluated by real‐time PCR, ELISA, cytometry and Western blotting. We found that the activity of Tr1 cells and IL‐10R signaling is impaired in MS patients since Tr1 cells isolated from MS patients produced less IL‐10 than those obtained from controls. Indeed, the supernatants from Tr1 cells from controls did not suppress the proliferation of stimulated CD4+ cells from patients with MS. Furthermore, the IL‐10R signaling pathway was not fully active in CD4+ cells from MS patients and these cells had higher baseline levels of SOCS3 transcripts than controls. Indeed, after in vitro IL‐10 stimulation, the expression levels of the STAT1, STAT3 and IL‐10RA genes were higher in MS patients than in controls. Moreover, Stat‐3 phosphorylation was lower in controls than in patients after IL‐10 stimulation. These results indicate that IL‐10 regulatory function is impaired in patients with MS.
Engineering tissue tubes using novel multilayered scaffolds in the rat peritoneal cavity
Authors: Cao Yang , Zhang Bing , Croll Tristan , Rolfe Barbara E. , Campbell Julie H. , Campbell Gordon R. , Martin Darren , Cooper‐White Justin J. 
Published: January 2008

AbstractOur aim was to develop novel scaffolds to engineer tissue tubes of smooth muscle‐like cells for autologous grafting. Small diameter tubular poly(lactic acid) scaffolds with randomly distributed, interconnected pores up to 100 μm were produced using a thermally induced phase separation method. The scaffolds were surface modified using various biomolecules via a layer‐by‐layer deposition technique, and implanted in the peritoneal cavities of rats. Histological analysis of scaffolds 3 weeks after implantation showed fully‐developed tissue capsules on their outer surfaces, with macrophage‐like cells present throughout the internal spaces. Surfaces coated in Matrigel supported the strongest cellular response whereas multilayer coatings with elastin, collagen I, collagen III, or chitosan outermost showed the lowest levels of cellular interaction. Although differences in capsule thickness and the presence or absence of cellularized layers on the inside and outside surfaces of the scaffolds were observed, none of these biomolecule coatings was able to overcome the foreign body response within the peritoneal cavity, even in the presence of a nonadsorptive HA undercoat. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
In vitro and in vivo characterization of porous poly‐L‐lactic acid coatings for subcutaneously implanted glucose sensors
Authors: Koschwanez H. E. , Yap F. Y. , Klitzman B. , Reichert W. M. 
Published: January 2008

AbstractThe purpose of this study was to test the hypothesis that porous poly‐L‐lactic acid (PLLA) sensor coatings reduce fibrosis and promote blood microvessel formation in tissue adjacent to the sensor surface. Porous PLLA coatings were produced using ammonium bicarbonate as the gas foaming/salt leaching agent, and deployed on functional and nonfunctional sensors. The porous coatings minimally affected sensor accuracy and response rate in vitro. Three‐week subcutaneous rat studies of nonfunctional glucose sensors showed the anticipated effect of porous coatings enhancing vascularity and decreasing collagen deposition. In contrast, percutaneous functional sensors with and without porous coatings showed no significant difference in terms of histology or sensor response. In spite of the observation that texturing increases the vascularity of the tissue that surrounds implanted sensors, other factors such as the additional mechanical stresses imposed by percutaneous tethering may override the beneficial effects of the porous coatings. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Magnetotransport of electrons in quantum Hall systems
Authors: Dmitriev I. A. , Evers F. , Gornyi I. V. , Mirlin A. D. , Polyakov D. G. , Wölfle P. 
Published: January 2008

AbstractRecent theoretical results on magnetotransport of electrons in a 2D system in the range of moderately strong transverse magnetic fields are reviewed. The phenomena discussed include: quasiclassical memory effects in systems with various types of disorder, transport in lateral superlattices, interaction‐induced quantum magnetoresistance, quantum magnetooscillations in dc and ac transport, and oscillatory microwave photoconductivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Myelomeningocele: neglected aspects
Authors: Woodhouse Christopher R. J. 
Published: January 2008

AbstractThe commonest cause of neurogenic bladder in children is myelomeningocele. Survival of children is much improved in the Western world, but by 35 years old, about 50% will have died. In adults, the commonest causes of death are lung and heart diseases. All physical aspects deteriorate with age, especially in those with thoracic lesions. Those who walk in childhood have a 20–50% chance of becoming wheelchair dependent as adults. Immobility, poor respiratory reserve, obesity, latex allergy and worsening kyphoscoliosis contribute to the increased risks of surgery. It is essential that safe and manageable urine drainage is established in childhood: the bladder never improves with time, and surgical reconstruction becomes progressively more difficult. Independence in adult life will only be possible with intense preparation in childhood. Children must be allowed to join in with family chores and events. Education, both academic and practical, must be encouraged. Skills such as driving, shopping and birth control must be taught. However, even with the best support, less than 40% will have gainful employment. Children who are continent and have lesions below L2 are likely to have normal sexual function. Sexual activity in adolescents, especially in those with hydrocephalus, is limited (but not absent). However, by adult life, about two thirds will have established a regular partnership. All females and those males who are naturally potent are likely to be fertile. There is a high risk of neural tube defects in their offspring unless the female partner takes prophylactic folic acid for 3 months before pregnancy and for first trimester.
PREDICTORS OF AGE AT MENARCHE IN THE NEWCASTLE THOUSAND FAMILIES STUDY
Authors: BLELL MWENZA , POLLARD TESSA M. , PEARCE MARK S. 
Published: January 2008

SummarySeveral studies have found relationships between early life factors (birth weight, length of gestation, height, weight, duration of breast-feeding, maternal age, social class, periods of infection, presence of adverse life events, and quality of housing conditions in childhood) and age at menarche but none has considered all of these factors in the same study. The follow-up study of the Newcastle Thousand Families birth cohort, established in 1947, provided age at menarche data collected retrospectively at age 50 from 276 women who returned self-completion questionnaires in 1997. Three main independent associations were observed: girls who experienced a shorter gestation, girls whose mothers were younger when they were born, and girls who were heavier at age 9 had earlier menarche. Birth weight, standardized for gestational age, was found to have different relationships with age at menarche depending upon how heavy or light a girl was at age 9. The results of this study support the hypotheses that conditions in fetal and early life are associated with the timing of menarche and that greater childhood growth is associated with earlier menarche. It is suggested that future work should focus on illuminating the mechanisms underlying these statistical relationships.
The effect of heterogeneous infectious period and contagiousness on the dynamics ofSalmonellatransmission in dairy cattle
Authors: LANZAS C. , BRIEN S. , IVANEK R. , LO Y. , CHAPAGAIN P. P. , RAY K. A. , AYSCUE P. , WARNICK L. D. , GRÖHN Y. T. 
Published: January 2008

SUMMARYThe objective of this study was to address the impact of heterogeneity of infectious period and contagiousness onSalmonellatransmission dynamics in dairy cattle populations. We developed three deterministic SIR-type models with two basic infected stages (clinically and subclinically infected). In addition, model 2 included long-term shedders, which were defined as individuals with low contagiousness but long infectious period, and model 3 included super-shedders (individuals with high contagiousness and long infectious period). The simulated dynamics, basic reproduction number (R0) and critical vaccination threshold were studied. Clinically infected individuals were the main force of infection transmission for models 1 and 2. Long-term shedders had a small impact on the transmission of the infection and on the estimated vaccination thresholds. The presence of super-shedders increasesR0and decreases the effectiveness of population-wise strategies to reduce infection, making necessary the application of strategies that target this specific group.
Use of Porous Alginate Sponges for Substantial Chondrocyte Expansion and Matrix Production: Effects of Seeding Density
Authors: Yen Chi‐Nan , Lin Yu‐Ru , Chang Margaret Dah‐Tsyr , Tien Chun‐Wen , Wu Yu‐Chih , Liao Chun‐Jen , Hu Yu‐Chen 
Published: January 2008

AbstractAutologous cell transplantation is a promising approach for cartilage repair, but the expansion of chondrocytes in a monolayer, a common approach to amplifying the cell number, inevitably leads to cell de‐differentiation. To explore whether porous alginate sponges could be utilized for chondrocyte expansion and investigate the effects of seeding densities, the porcine chondrocytes were seeded to porous alginate sponges at low (5 × 105 cells per 40 sponges), medium (5 × 106 cells per 40 sponges), or high (2 × 107 cells per 40 sponges) density. After 4‐week perfusion culture, all three groups resulted in chondrocyte proliferation, maintenance of chondrocytic gene (collagen II, Sox 9 and aggrecan) expression, and formation of cell clusters resembling cartilaginous tissues. The higher the seeding density, the higher the final cell density and GAGs production and, accordingly, the larger the cell clusters. Strikingly, the cumulative expansion ratios achieved by the low‐density group (∼150‐fold) significantly exceeded those achieved by the medium (∼21‐fold) and high (∼4.7‐fold) density groups, as well as those achieved using other scaffolds. In conclusion, seeding chondrocytes to the alginate sponges at a low density, combined with perfusion culture, represents a drastic improvement in expanding autologous chondrocytes.
Acute Limbic Encephalitis: Diagnostic and Management Implications
Authors: Lucas-Ramadan Tracey , Baxi Shrujal , Velamoor Raj 
Published: January 2008

Objective: A link between cancer and limbic encephalitis (LE) has been proposed. The aim of this case presentation is to further explore this association by literature review, inform clinicians of the investigations necessary to arrive at a diagnosis and to emphasize the clinical importance of liaison between psychiatry and other disciplines involved in management. Method: The case report of a 55 year old Niuean male school teacher with an acute onset of confusion and personality change is presented. The clinical data was obtained from various sources including the emergency room, medical ward, psychiatric ward as well as from discussions with other physicians involved in the management of this case. Family members and friends were also contacted to obtain corroborative historical information. Results: LE was diagnosed in this case based on clinical presentation with psychiatric symptoms, ruling out delirium due to infections, metabolic and other toxins as well as magnetic resonance imaging findings confirming temporal lobe changes. Conclusion: LE is a known paraneoplastic syndrome (PNS) that may precede the diagnosis of an underlying malignancy. Recent advances in laboratory technology now allow for antibodies to be identified in specific malignancies. This behooves the clinicians to maintain a high level of diagnostic suspicion so that timely interventions with oncology can follow.
CHARACTERISTIC OF SURFACE WAVES IN NONLINEAR LEFT HANDED — PHOTOSENSITIVE SEMICONDUCTOR WAVEGUIDE STRUCTURE
Authors: HAMADA M. S. , EL-ASTAL A. H. , SHABAT M. M. 
Published: January 2008

The nonlinear electromagnetic surface waves in waveguide structure which contains photosensitive semiconductor layer and left-handed material (LHM) layer have been studied. The effects of light intensity and the LHM on the dispersion of electromagnetic surface waves have been investigated. It has been noticed that, as a result of the foundation of LHM layer in the structure, both forward and backward electromagnetic surface waves exist in the waveguide. It has also been shown that the photosensitive semiconductor layer controls the propagation characteristics of the electromagnetic surface waves. The power flow of the nonlinear surface waves has also been examined. It has been found that the majority of the electromagnetic surface waves propagate in the forward direction.