bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microalgae‐promoted photodegradation of two endocrine disrupters in aqueous solutions
Authors: Ge Liyun , Deng Huanhuan , Wu Feng , Deng Nansheng 
Published: September 2008

AbstractBACKGROUND: Photodegradation is one method to remove the organic pollutants in wastewater. The photodegradation of 17α‐ethynylestradiol (EE2) and 17β‐ estradiol (E2) was investigated using freshwater algae suspended in aqueous solutions under a high‐pressure mercury lamp (250 W). Three algal species were used: Chlorella vulgaris (CV), Anabaena cylindrica (AC) and Microcytis aeruginosa kutz (MA). Reactions were carried out under aerobic conditions.RESULTS: The three algal species are capable of promoting the photodegradation of EE2 and E2. For example, in the A. cylindrica suspensions, with cell density ranging from 7.0 × 105 cells mL−1 to 8.4 × 106 cells mL−1, the photodegradation rate of EE2 was increased from 14% to 28%. Reactive oxygen species were thought to be the main reason for the degradation of endocrine disrupting chemicals (EDCs). Hydroxyl radicals and singlet oxygen photogenerated in the algal suspensions were detected. About 4 µmol L−1 hydroxyl radicals were generated in the 4 h reaction.CONCLUSION: Oxidative photodegradation of a solution of endocrine disrupters promoted by algae leads to noticeable decrease in the toxicity of the solution. Oxygen plays an important role in the formation of reactive oxygen species in the algal suspensions. Copyright © 2008 Society of Chemical Industry
Generation of spinal motor neurons from human fetal brain‐derived neural stem cells: Role of basic fibroblast growth factor
Authors: Jordan Paivi M. , Ojeda Luis D. , Thonhoff Jason R. , Gao Junling , Boehning Darren , Yu Yongjia , Wu Ping 
Published: September 2008

AbstractNeural stem cells (NSCs) have some specified properties but are generally uncommitted and so can change their fate after exposure to environmental cues. It is unclear to what extent this NSC plasticity can be modulated by extrinsic cues and what are the molecular mechanisms underlying neuronal fate determination. Basic fibroblast growth factor (bFGF) is a well‐known mitogen for proliferating NSCs. However, its role in guiding stem cells for neuronal subtype specification is undefined. Here we report that in‐vitro‐expanded human fetal forebrain‐derived NSCs can generate cholinergic neurons with spinal motor neuron properties when treated with bFGF within a specific time window. bFGF induces NSCs to express the motor neuron marker Hb9, which is blocked by specific FGF receptor inhibitors and bFGF neutralizing antibodies. This development of spinal motor neuron properties is independent of selective proliferation or survival and does not require high levels of MAPK activation. Thus our study indicates that bFGF can play an important role in modulating plasticity and neuronal fate of human NSCs and presumably has implications for exploring the full potential of brain NSCs for clinical applications, particularly in spinal motor neuron regeneration. © 2008 Wiley‐Liss, Inc.
Reduced anxiety in the mice expressing mutant (N141I) presenilin 2
Authors: Yuk Dong Yeon , Lee Yong Kyung , Nam Sang Yoon , Yun Young Won , Hwang Dae Youn , Choi Dong Young , Oh Ki Wan , Hong Jin Tae 
Published: September 2008

AbstractAlzheimer's disease (AD) is characterized by progressive cognitive impairment. The effect of presenilin 1 (PS1) and PS2 mutation on cognition has been well characterized in a variety of transgenic mice. However, noncognitive behaviors have not been considered in these mice. In the present study, we found that transgenic mice expressing mutant PS2 (N141I) displayed decreased anxiety behavior determined by the elevated plus maze test and the light dark box test. However, these mice showed biphasic ambulatory activity (hyperactivity followed by hypoactivity) in an open field test. Correlated well with the reduced anxiety, expression of GABAAα1 receptor was higher whereas c‐Fos was lower in the cortex, hippocampus, and amygdala of the mice expressing PS2 mutation than those of the wild‐type PS2 or nontransgenic control mice. These data indicate that PS2 mutation causes reduction of anxiety, and this effect may be related to the change of the expression of GABAAα1 receptor and c‐Fos. These findings could be useful in the understanding and the treatment of AD patients. © 2008 Wiley‐Liss, Inc.
Nicotinic receptor stimulation protects nigral dopaminergic neurons in rotenone‐induced Parkinson's disease models
Authors: Takeuchi Hiroki , Yanagida Takashi , Inden Masatoshi , Takata Kazuyuki , Kitamura Yoshihisa , Yamakawa Kentaro , Sawada Hideyuki , Izumi Yasuhiko , Yamamoto Noriyuki , Kihara Takeshi , Uemura Kengo , Inoue Haruhisa , Taniguchi Takashi , Akaike Akinori , Takahashi Ryosuke , Shimohama Shun 
Published: September 2008

AbstractParkinson's disease (PD) is the second most common neurodegenerative disease and is characterized by dopaminergic (DA) neuronal cell loss in the substantia nigra. Although the entire pathogenesis of PD is still unclear, both environmental and genetic factors contribute to neurodegeneration. Epidemiologic studies show that prevalence of PD is lower in smokers than in nonsmokers,. Nicotine, a releaser of dopamine from DA neurons, is one of the candidates of antiparkinson agents in tobacco. To assess the protective effect of nicotine against rotenone‐induced DA neuronal cell toxicity, we examined the neuroprotective effects of nicotine in rotenone‐induced PD models in vivo and in vitro. We observed that simultaneous subcutaneous administration of nicotine inhibited both motor deficits and DA neuronal cell loss in the substantia nigra of rotenone‐treated mice. Next, we analyzed the molecular mechanisms of DA neuroprotective effect of nicotine against rotenone‐induced toxicity with primary DA neuronal culture. We found that DA neuroprotective effects of nicotine were inhibited by dihydro‐β‐erythroidine (DHβE), α‐bungarotoxin (αBuTx), and/or PI3K‐Akt/PKB (protein serine/threonine kinase B) inhibitors, demonstrating that rotenone‐toxicity on DA neurons are inhibited via activation of α4β2 or α7 nAChRs‐PI3K‐Akt/PKB pathway or pathways. These results suggest that the rotenone mouse model may be useful for assessing candidate antiparkinson agents, and that nAChR (nicotinic acetylcholine receptor) stimulation can protect DA neurons against degeneration. © 2008 Wiley‐Liss, Inc.
Vitreous humor and albumin augment the proliferation of cultured retinal precursor cells
Authors: Yang Jing , Klassen Henry , Pries Mette , Wang Wei , Nissen Mogens H. 
Published: September 2008

AbstractIntravitreal injection is an important delivery route for studies involving the transplantation of various types of precursor cells to the retina; however, the effect on these cells of exposure to the vitreous microenvironment has not been specifically investigated. Here vitreous humor was evaluated for the potential to influence the proliferation of rat retinal precursor cells in vitro. Cells were isolated at embryonic day 19 and plated in standard proliferation medium in the presence or absence of fluid expressed from porcine vitreous humor. Cellular proliferation at different concentrations of vitreous fluid supplementation was quantified by using a 3H‐thymidine incorporation assay. Active components of vitreous fluid were partially characterized by gel filtration chromatography (GFC) and UV spectral analysis. The effect of each vitreous fraction on proliferation was determined as well. Results showed that addition of 20% vitreous fluid to primary rat retinal cultures significantly increased 3H‐thymidine incorporation compared with growth medium without vitreous supplementation. A vitreous fraction showing growth‐promoting activity was localized to a molecular mass range <1000 Da, consistent with ascorbic acid. Ascorbic acid was confirmed in vitreous fluid by UV spectral analysis. Growth‐augmenting activity was present in higher molecular mass vitreous fractions, consistent with protein components. Albumin, the major protein in vitreous fluid, was found to augment proliferation. Because vitreous‐associated augmentation of retinal precursor proliferation remains an epidermal growth factor‐dependent phenomenon, the proliferative status of transplanted cells in the vitreous cavity is likely determined by a combination of factors. © 2008 Wiley‐Liss, Inc.
COG1410, a novel apolipoprotein‐E mimetic, improves functional and morphological recovery in a rat model of focal brain ischemia
Authors: Tukhovskaya Elena A. , Yukin Alexey Yu. , Khokhlova Oksana N. , Murashev Arkady N. , Vitek Michael P. 
Published: September 2008

AbstractApolipoprotein E (apoE) is the primary apolipoprotein synthesized in the brain in response to injury with known neuroprotective effects exerted through antioxidant, antiinflammatory, antiexcitotoxic, and neurotrophic mechanisms. We have previously demonstrated that COG1410, an apoE mimetic peptide, exerts neuroprotective and antiinflammatory effects in a murine model of traumatic brain injury (TBI). As in TBI, ischemia‐reperfusion injury is a component of acute stroke, which displays a pharmacogenetic association with the APOE4 gene. Using an intraluminal middle cerebral occlusion (MCAO) model in rats, we found that a single intravenous injection of COG1410 at 120 min post‐MCAO significantly improved vestibulomotor function, decreased poststroke locomotor asymmetry, and decreased infarct volume of the ipsilateral hemisphere. These results support further exploration of a novel apoE‐mimetic peptide, COG1410, as a therapeutic treatment for stroke. © 2008 Wiley‐Liss, Inc.
Antibiotics, arsenate and H2O2 induce the promoter of Staphylococcus aureus cspC gene more strongly than cold
Authors: Chanda Palas Kumar , Mondal Rajkrishna , Sau Keya , Sau Subrata 
Published: September 2008

AbstractProteins expressed by the bacterial cold shock genes are highly conserved at sequence level and perform various biological functions in both the cold‐stressed and normal cells. To study the effects of various agents on the cold shock genes of Staphylococcus aureus, we have cloned the upstream region of cspC from S. aureus Newman and found that the above region possesses appreciable promoter (Pc) activity even at 37 °C. A reporter S. aureus strain CHANDA2, constructed by inserting the Pc ‐lacZ transcriptional fusion into S. aureus RN4220 genome, was found to express very low level of β ‐galactosidase after cold shock, indicating that low temperature induces Pc very weakly. Interestingly, transcription from Pc was induced very strongly by several antibiotics, hydrogen peroxide and arsenate salt. Cold shock proteins expressed by S. aureus are highly identical at sequence level and bear single‐strand nucleic acid binding motifs. A 16 nt downstream box and a 13 nt upstream box were identified at the downstream of initiation codon and at the upstream of ribosome binding site of csp transcripts. Their roles in S. aureus cold shock gene expression have been discussed elaborately. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibrational spectral studies on charge transfer and ionic hydrogen‐bonding interactions of nonlinear optical material L‐arginine nitrate hemihydrate
Authors: Vijayakumar T. , Hubert Joe I. , Reghunadhan Nair C. P. , Jayakumar V. S. 
Published: September 2008

AbstractThe near infrared Fourier‐transform (NIR FT)‐Raman and Fourier‐transform infrared (FT‐IR) spectroscopies supported by HF/6‐31G(d) computations have been employed to derive equilibrium geometry, vibrational wavenumbers and the first hyperpolarizability of the nonlinear optical (NLO) material, L‐arginine nitrate (LAN) hemihydrate. The reasonable NLO efficiency, predicted for the first time in this novel compound, has been confirmed by Kurtz–Perry powder second harmonic generation (SHG) experiments. The changes in the atomic charge distribution among different groups due to the presence of strong electronegative atoms and the shrinking of NO bonds of nitrate anion and CN bonds of guanidyl group have been analyzed. The splitting of the carboxylate stretching modes, blue shifting of methine vibrations and the electronic effects such as backdonation and induction on the methylene hydrogen atoms have also been examined in detail. The intense low wavenumber H‐bond Raman vibrations due to electron–phonon coupling and nonbonded interactions in making the LAN molecule NLO active have been discussed based on the vibrational spectral features. The natural bond orbital (NBO) analysis and HF computations confirm the occurrence of strong intra‐ and intermolecular NH·O and OH·O ionic hydrogen bonding between charged species providing the noncentrosymmetric structure in the LAN crystal. Copyright © 2008 John Wiley & Sons, Ltd.
Antioxidant phenolic esters with potential anticancer activity: solution equilibria studied by Raman spectroscopy
Authors: Machado N. F. L. , Calheiros R. , Gaspar A. , Garrido J. , Borges F. , Marques M. P. M. 
Published: September 2008

AbstractThe solution Raman pattern of a series of structurally related hydroxycinnamic and hydroxybenzoicesters (caffeates and gallates) with potential antioxidant/anticancer activity was studied, for different biologically significant concentrations. The spectra were assigned with the help of theoretical calculations in the light of previously reported experimental data for these compounds in the solid state. Evidence of the formation of dimeric entities in solution, via (C)···O···H(O) and/or (C)O···H(C) intermolecular hydrogen bonds, was obtained. The dimer‐to‐monomer equilibrium, which influences the antioxidant activity of this kind of systems, was monitored through Raman titration experiments. Copyright © 2008 John Wiley & Sons, Ltd.
Origin of the forbidden phonons in Raman scattering spectra of uranium‐doped Ca2CuO3, a spin 1/2 chain system
Authors: Hoang Nam Nhat , Nguyen Thuy Trang , Van Bui Hong , Nguyen Duc Tho 
Published: September 2008

AbstractThe Raman scattering spectra of uranium‐doped Ca2CuO3 were investigated. The small doping of uranium (≤5%) in this one‐dimensional spin 1/2 chain system induced three new first‐order scattering bands and two new multiphonon bands in the structure of forbidden phonons. The first‐order bands were found to agree well with the existing theoretical results from the ab initio and tight‐binding calculation. Among them, the 470 and 665 cm−1 bands appeared as the basic wavenumbers of which the multiphonon overtones were composed. The grain size effect in this strongly anisotropic system was proposed not to originate from the classical phonon confinement but rather as a result of the segmentation of one‐dimensional spin chains due to doping, which in turn allowed the new vibrational modes and implied the appearance of higher overtones in the scattering spectra. Copyright © 2008 John Wiley & Sons, Ltd.
On the relative intensities of the Raman active fundamentals, r0 structural parameters, and pathway of chair–boat interconversion of cyclohexane and cyclohexane‐d12
Authors: Durig James R. , Zheng Chao , El Defrawy Ahmed M. , Ward Rachel M. , Gounev Todor K. , Ravindranath K. , Rajeswara Rao N. 
Published: September 2008

AbstractRaman spectra of liquid cyclohexane, C6H12, and deuterated cyclohexane, C6D12, were recorded with both parallel and perpendicular polarizations. The observed vibrational wavenumbers, depolarization ratios, and their intensities were measured and compared with the corresponding predicted values as well as the experimental values previously reported. The conformational energetics were obtained with the Møller–Plesset perturbation method to the second order [MP2(full)] as well as with density functional theory by the B3LYP method utilizing a variety of basis sets. The average ab initio predicted difference in energy between the more stable chair form (D3d) and the less stable twisted‐boat form (D2) is 2213 cm−1 (26.47 kJ/mol), with a similar value of 2223 cm−1 (26.59 kJ/mol) from the density function theory calculations. By using two dihedral angles as variables, we calculated the chair–boat interconversion pathway for cyclohexane at the MP2(full)/6‐31G(d) level. The harmonic force constants, Raman intensities, depolarization values, and the potential energy distribution were predicted from both MP2(full) and B3LYP calculations with the 6‐31G(d) basis set and compared with the experimental values for the chair form when available. The ‘adjusted’ r0 structural parameters were obtained from MP2/6‐311 + G(d,p) calculations and previously reported microwave rotational constants of five isotopomers of cyclohexane: i.e. 1,1‐d2, 13C‐1,1‐d2, 1,1,2,2,3,3‐d6, and d1 (equatorial and axial). The determined distances in Å are: r(CC) = 1.536(3), r(CH)ax = 1.098(1); r(CH)eq = 1.095(1); and the angles in degrees: ∠CCHax = 108.8(3); ∠CCHeq = 110.2(3); ∠CCC = 111.1(3); and ∠HCH = 107.6(3) with dihedral angle ∠CCCC = 55.7(3). These values are compared with those previously reported and it is found that the difference in the r0 distances (0.003 Å) between the two CH values is much smaller than the difference (0.008 Å) previously reported for the rs values. Copyright © 2008 John Wiley & Sons, Ltd.
Laser‐induced phase changes in olivine FePO4: a warning on characterizing LiFePO4‐based cathodes with Raman spectroscopy
Authors: Burba Christopher M. , Palmer Jasin M. , Holinsworth Brian S. 
Published: September 2008

AbstractRaman spectroscopy is an excellent technique for probing lithium intercalation reactions of many diverse lithium ion battery electrode materials. The technique is especially useful for probing LiFePO4‐based cathodes because the intramolecular vibrational modes of the PO43− anions yield intense bands in the Raman spectrum, which are sensitive to the presence of Li+ ions. However, the high power lasers typically used in Raman spectroscopy can induce phase transitions in solid‐state materials. These phase transitions may appear as changes in the spectroscopic data and could lead to erroneous conclusions concerning the delithiation mechanism of LiFePO4. Therefore, we examine the effect of exposing olivine FePO4 to a range of power settings of a 532‐nm laser. Laser power settings higher than 1.3 W/mm2 are sufficient to destroy the FePO4 crystal structure and result in the formation of disordered FePO4. After the laser is turned off, the amorphous FePO4 compound crystallizes in the electrochemically inactive α‐FePO4 phase. The present experimental results strongly suggest that the power setting of the excitation laser should be carefully controlled when using Raman spectroscopy to characterize fundamental lithium ion intercalation processes of olivine materials. In addition, Raman spectra of the amorphous intermediate might provide insight into the α‐FePO4 to olivine FePO4 phase transition that is known to occur at temperatures higher than 450 °C. Copyright © 2008 John Wiley & Sons, Ltd.
Binary mixture of p‐methylbenzaldehyde with polar and nonpolar solvents
Authors: Anis Fathima A. , Ramakrishnan V. 
Published: September 2008

AbstractIn this work, a combined theoretical and experimental study of binary mixture of liquid p‐methylbenzaldehyde (PMBz) is reported using ab initio calculations as well as Raman and IR spectroscopies. The purpose of this study was twofold: firstly, to describe the interaction of PMBz in terms of bonding energies and preferred geometries; and secondly, to characterize the spectroscopic effects on the vibrational modes of PMBz in the binary mixture of different polar and nonpolar solvents. The three vibrational modes, namely, carbonyl stretching, ν(CCH3) and aldehydic (CH) vibrations have been analyzed in all the three solvents in different concentrations. The dependence of Raman linewidth on the concentration of PMBz of these modes was also taken into account. By analyzing the peak position and linewidth of these modes, it is seen that the solute–solvent interaction is stronger in BuOH and 1,2 dichloroethane (DCE) because of the hydrogen‐bonding interaction between these molecules. The formation of CH···O hydrogen bonds in liquid p‐methylbenzaldehyde is also investigated by Gaussian fitting. The ab initio calculations suggest several possible dimer configurations. Copyright © 2008 John Wiley & Sons, Ltd.
Investigation on microstructures of MnSix thin films by Raman spectroscopy
Authors: Wang J. L. , Su W. F. , Xu R. , Fan Y. L. , Jiang Z. M. 
Published: September 2008

AbstractIn this paper, Raman spectroscopy is used to study the microstructures of MnSix thin films annealed at different temperatures. Two phases of Mn silicides, MnSi1.73 and MnSi, are identified, and their Raman spectra are reported. Each phase of Mn silicides shows a set of three well‐defined peaks at about 300 cm−1 in the spectrum, which could be used as fingerprints in identifying the formation of the Mn silicides. Compared with conventional X‐ray diffraction method, Raman spectroscopy is found to be more sensitive to investigate the microstructures of Mn silicides, especially at the initial stage of formation of the Mn silicides. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of radix ginseng volatile oils at different ages by comprehensive two‐dimensional gas chromatography/time‐of‐flight mass spectrometry
Authors: Qiu Yaqiong , Lu Xin , Pang Tao , Ma Chenfei , Li Xiang , Xu Guowang 
Published: September 2008

AbstractComprehensive 2‐D GC (GC×GC) coupled with TOF MS or flame ionization detector (FID) was employed to characterize and quantify the chemical composition of volatile oil in the radixes of Panax ginseng C. A. Mey. (ginseng) at different ages. Thirty‐six terpenoids were tentatively identified based on the MS library search and retention index in a ginseng sample at the age of 3 years. An obvious group‐type separation was obtained in the GC×GC‐TOF MS chromatogram. The data collected by GC×GC‐FID were processed using a principal component analysis (PCA) method to classify the samples at different ages. The compounds responsible for the significant differentiation among samples were defined. It was found that the relative abundances of α‐cadinol, α‐bisabolol, thujopsene, and n‐hexadecanoic acid significantly rise with the increase in age.
Comprehensive two‐dimensional gas chromatography analysis of high‐ethanol containing motor fuels
Authors: Seeley John V. , Libby Elise M. , Seeley Stacy K. , McCurry James D. 
Published: September 2008

AbstractA comprehensive 2‐D GC (GC×GC) instrument equipped with a flow‐switching modulator was used to determine the concentration of ethanol and eight other alcohols in a retail pump sample of E85 fuel. E85 is a mixture of ethanol and gasoline where the ethanol concentration can range from 70 to 85 vol%. The increased peak capacity and selectivity generated by GC×GC analysis allowed the alcohols to be fully resolved from the gasoline hydrocarbons. GC×GC analysis was compared to the performance obtained with the standard analytical method for determining ethanol in fuel ethanol (ASTM D5501) and the standard method for determining oxygenate concentrations in gasoline (ASTM D4815). The GC×GC analysis required 14 min while the combined ASTM D5501 and ASTM D4815 analyses required more than 60 min. The ethanol concentration obtained by GC×GC was in excellent agreement with the value obtained by the D5501 method. Poorer agreement was observed between the GC×GC and D4815 concentrations for the other alcohols present in E85. In all cases, the differences could be attributed to deficiencies in the D4815 method that led to coelutions between the alcohols and gasoline hydrocarbons.