bluuebunny/crossref_metadata_2025_split huggingface dataset:
A population of oligodendrocytes derived from multipotent neural precursor cells expresses a cholinergic phenotype in culture and responds to ciliary neurotrophic factor
Authors: MacDonald S.C. , Simcoff R. , Jordan L.M. , Dodd J.G. , Cheng K.W. , Hochman S. 
Published: August 2002

AbstractBecause oligodendrocytes and their precursors possess receptors for classical transmitters, and neurotransmitters such as glutamate and noradrenaline can mediate oligodendroglial proliferation and differentiation, it is possible that other neurotransmitters can also exert regulatory roles in oligodendrocyte function. We used mitogen‐proliferated multipotent neuroepithelial precursors (neurospheres) and identified oligodendroglia that expressed markers traditionally found in cholinergic neurons. Regardless of culture conditions, there existed a large population of cells that resembled oligodendrocytes morphologically and coexpressed the oligodendrocyte‐specific marker galactocerebroside (GalC) and the acetylcholine (ACh)‐synthesizing enzyme choline acetyltransferase (ChAT). These cells did not express neuronal markers, and whole‐cell recordings from cells with similar morphology displayed only outward currents in response to depolarizing voltage steps, further supporting their oligodendroglial identity. Another cholinergic marker, the vesicular ACh transporter, was also detected in GalC+ oligodendrocytes. Furthermore, neurospheres cultured in the presence of the cholinergic receptor antagonist atropine showed a decrease in the number of GalC+ spheres, implicating the muscarinic ACh receptor in oligodendrocyte development. The actions of neurotrophins and ciliary neurotrophic factor (CNTF) on these ChAT+ oligodendrocytes were examined. Among these, CNTF treatment significantly increased oligodendrocytic process outgrowth. These results demonstrate classical cholinergic neuronal markers in oligodendrocytes as well as an effect of muscarinic receptor blockade on oligodendrocyte differentiation. © 2002 Wiley‐Liss, Inc.
Altered expression of glutamate transporters under hypoxic conditions in vitro
Authors: Hsu Leigh , Rockenstein Edward , Mallory Margaret , Hashimoto Makoto , Masliah Eliezer 
Published: August 2002

AbstractRegulation of extracellular excitotoxins by glial and neuronal glutamate transporters is critical to maintain synaptic terminal integrity. Factors interfering with the normal functioning of these transporters might be involved in neurodegeneration. Among them, recent studies have shown that hypoxia alters glutamate transporter function; however, it is unclear if hypoxia has an effect on the expression of glutamate transporters and which intracellular signaling pathways are involved. The C6 rat glial and GT1–7 mouse neuronal cell lines were exposed to hypoxic conditions (5% CO2, 95% N2) and levels of glutamate transporter mRNA were determined by ribonuclease protection assay. After 21 hr, there was a 100% increase in levels of rat excitatory amino acid transporter 3 (EAAT3) mRNA in C6 cells and a 600% increase in levels of murine EAAT2 mRNA in GT1–7 cells. There was a similar increase in mRNA levels after hypoxia in C6 cells transfected with human EAAT2, whereas reoxygenation normalized the expression levels of glutamate transporters. Although the expression of EAATs was associated with increased immunoreactivity by Western blot, functioning of the transporters was decreased as evidenced by D‐aspartate uptake. Finally, although the protein kinase C stimulator phorbol‐12‐myristate‐13‐acetate enhanced EAAT2 mRNA levels after hypoxia, protein kinase C inhibitor bisindolylmaleimide I had the opposite effect. Taken together, this study suggests that the hypoxia is capable of upregulating levels of EAATs via a protein kinase C‐dependent compensatory mechanism. This increased expression is not sufficient to overcome the decreased functioning of the EAATs associated with decreased ATP production and mitochondrial dysfunction. J. Neurosci. Res. 64:193–202, 2001. © 2001 Wiley‐Liss, Inc.
Spatial and temporal persistence of mean monthly temperature on two GCM grid cells
Authors: Hoff C. 
Published: August 2002

AbstractThe study investigates a simple statistically based scheme for translating large scale general circulation model (GCM) information to local scale where natural and socio‐economic environments are dependent on climatic variables. Two GCM grid cells were chosen, one centred on Montpellier (France), the other on Sevilla (Spain). For each meteorological station over these cells, the relative values of mean monthly temperature compared with the GCM grid cell mean were expressed as percentages, and were called ‘relative temperatures’ (RT). Using geostatistical procedures, the spatial structure of RT was sought on both GCM grid cells, with the altitude as external drift. The months of January and July were studied during the 1979–1993 period. For each month, the characteristics of the variograms of RT are close for each year of the period. There is also a good inter‐annual persistence of spatial patterns of RT when the correlation between altitude and RT is significant. The results will be of great interest for easily estimating local values of mean monthly temperature at any place within each grid cell without further calculation. Copyright © 2001 Royal Meteorological Society
The origin and flux of icebergs released into the Last Glacial Maximum Northern Hemisphere oceans: the impact of ice‐sheet topography
Authors: Bigg Grant R. , Wadley Martin R. 
Published: August 2002

AbstractThe precipitation fields of a palaeoatmospheric general circulation model are used to derive estimates of the geographical distribution, and flux, of icebergs from the Laurentide, Fennoscandinavian and eastern Siberian ice‐sheets at the Last Glacial Maximum (LGM). The atmospheric model fields from LGM simulations using CLIMAP or Peltier (ICE‐4G) ice orography were studied, to test the sensitivity of the predicted flux. The estimated Northern Hemispheric LGM iceberg flux is 3500–4000 km3 yr−1, of which about 60% issued directly into the North Atlantic. The iceberg flux from the St Lawrence area is of similar significance to that issuing from Hudson Strait in all estimates. Both the North Pacific and the Arctic received substantial iceberg fluxes (ca. 700 km3 yr−1), with relatively minor differences occurring between the two ice‐sheet reconstructions. Apparent discrepancies between Arctic deep‐sea core samples of ice‐rafted debris and our estimates of mean glacial iceberg flux may be ascribed to coastal trapping of bergs, the existence of floating ice tongues or a rapid exit of icebergs from the Arctic basin into the Greenland Sea through the Fram Strait. Copyright © 2001 John Wiley & Sons, Ltd.
A SERS probe of adenyl residues available for intermolecular interactions. Part I—adenyl ‘fingerprint’
Authors: Grajcar Lydie , Baron Marie‐Hélène 
Published: August 2002

AbstractThis work validated a SERS probe able to compare adenyl reactivity in DNA and RNA. A Creighton silver colloid including adenine (A) [or 2′‐deoxyadenosine 5′‐phosphate (pdA)] from 2 × 10−3 to 2 × 10−8 M is stabilized in the absence or presence of chloride. Concentration‐dependent SER spectral profiles reveal how A may interact with (Ag)n+ sites. At concentration ≥2 × 10−5 M adsorption of (A)n clusters prevents the colloid from undergoing salt effects. Adsorption via N1/N3 is allowed whereas C6NH2 is involved in self‐association. At [A] <2 × 10−5 M with chloride, hydrogen bonding between chloride and the C6NH2 group enhances C6N electronegativity, which assists C6N/N7 cooperative adsorption. Complex A(Cl−) entities compete with individual chloride ions for adsorption on silver. Very similar C6N/N7 adenyl adsorption occurs for pdA but only above 2 × 10−5 M. Chloride–adenyl bonding is reduced and pdA self‐association is weaker than adenine self‐association. Steric factors, repulsive electrostatic forces and phosphate competitive reactivity with respect to chloride may explain the much higher pdA concentration needed to saturate the silver surface compared with A. Mg2+–phosphate complexation entails concentration‐dependent opposite effects on adenyl reactivity with (Ag)n+ sites. Cytosine, thymine and guanine base or corresponding nucleotides deliver weaker SER spectra and much higher SERS responses for chloride adsorption compared with A or pdA. This reveals a weaker adsorption of the oxo bases, assumed to result from alternative oxo and nitrogen interactions with the (Ag)n+ sites. Copyright © 2001 John Wiley & Sons, Ltd.
Surface‐enhanced Raman spectroscopic studies of 2‐mercaptobenzoxazole on silver sols
Authors: Bigotto Adriano , Pergolese Barbara 
Published: August 2002

AbstractSurface‐enhanced Raman spectra of 2‐mercaptobenzoxazole (MBO) adsorbed on silver hydrosol were obtained. From the comparison of the SER and normal Raman spectra, both in the solid state and in NaOH solution, it can be deduced that the molecule is dissociatively adsorbed on the silver sol. The similarity between SER and normal Raman spectra of the corresponding silver complex is diagnostic of chemisorption of MBO on the metal surface. The SERS data were interpreted with the help of the results of RHF ab initio calculations both of the MBO anion, in which the 6–31 + G** basis set was used, and of the corresponding silver complex AgMBO, performed with the LANL2DZ basis set. On the basis of the description provided by the potential energy distribution of the vibrational normal modes related to the most enhanced bands in the SER spectra, it can be deduced that MBO interacts with the silver sol via the lone pairs of the sulphur and of the nitrogen atoms and, to some extent, also through the ring‐π system, assuming a tilted orientation with respect to the metal surface. Copyright © 2001 John Wiley & Sons, Ltd.
Secondary structure and association of melittin during and after solid‐phase synthesis: a Raman and static light scattering study
Authors: Lund Hansen C. , Robert Hansen P. , Callisen T. H. , Bauer R. , Faurskov Nielsen O. 
Published: August 2002

AbstractThe solid‐phase synthesis of melittin, a haemolytic peptide containing 26 amino acid residues, was monitored by near‐infrared Fourier transform Raman spectroscopy. The resin used was Tenta Gel S RAM. The secondary peptide structure was investigated for each step in the synthesis. A random coil secondary structure was the most probable in all cases, and accordingly all steps in the synthesis gave good yields. Melittin cleaved from the resin showed an α‐helix secondary structure in the solid state. Raman spectra were obtained for 10, 5, 4, 2 and 1% (w/w) aqueous solutions. The 1 and 2% solutions showed too weak melittin bands to be able to draw conclusions about the secondary structure. However, the more concentrated solutions evidently showed an α‐helical structure. Simultaneous static light scattering, refractive index measurements and exclusion chromatography on synthetic melittin in 50 mM phosphate (pH 7) and 150 mM NaCl showed the presence of dimers and tetramers in the eluted liquid. No evidence of monomers or trimers was found. Copyright © 2002 John Wiley & Sons, Ltd.
Turning innovation into profit
Authors: Millier Paul , Palmer Roger 
Published: August 2002

Abstract

The generic ‘stage and gate process’ is popularly accepted as a means for managing new product development. It advocates that a development project is divided into a series of pre‐defined decision steps in order to balance investment against perceived market risk and return.

Its use implies a number of assumptions — first that the product can be characterized as having features and customers benefits; and second that the market for such a product is identifiable.

This paper describes a process to assist decision making where these two assumptions do not apply. It provides suggestions to assist in the management and development of innovation and new technology, advocating that a marketing‐based perspective of supply‐led innovation is adopted.

Copyright © 2001 John Wiley & Sons, Ltd.
Comparison of the antioxidant and pro‐oxidant activities of broccoli amino acids with those of common food additives
Authors: Martínez‐Tomé Magdalena , García‐Carmona Francisco , Murcia M Antonia 
Published: August 2002

AbstractThe antioxidant and pro‐oxidant activities of broccoli amino acids were compared with those of common food additives. In decreasing order, the data showed that Asp, SMC, GABA, Glu, Gln, Pro, Phe, Leu, Lys, Arg, Asn, Val, Ile, His, Ser, Gly, Orn and Ala, when dissolved in water at concentrations of 0.5 and 0.05 mM, partially inhibited damage to deoxyribose in the presence of ferric‐EDTA and H2O2. In contrast, Tyr and Thr acted as pro‐oxidants in this system. The amino acids present in broccoli had no hydrogen peroxide‐scavenging effect. When dissolved in water, methanol or ethanol, SMC, Glu, Thr, Gln, Ser, GABA, Pro, Ala, Ile, Phe, Asp, Orn and Tyr inhibited lipid peroxidation. However, Asn, Val, Arg, Leu, Lys, His and Gly were not effective in decreasing peroxidation at concentrations of 0.5 and 0.05 mM. Asp > SMC > Ala > Phe > Hys > Orn > Gln = Ser > Lys > Leu = GABA = Gly > Tyr > Arg = Thr > Val > Asn > Pro > Ile > Glu (p < 0.025) showed scavenging activity towards hypochlorous acid, protecting α1‐antiproteinase against inactivation. In this paper it has been established that some amino acids premixed with propyl gallate increase its hypochlorous acid‐scavenging capacity, while other amino acids have an additive effect with propyl gallate, permitting smaller quantities of propyl gallate to be used as food additives in some products which contain these amino acids.© 2001 Society of Chemical Industry
Towards the production of pharmaceutical fatty acids in transgenic plants
Authors: Napier Johnathan A , Michaelson Louise V 
Published: August 2002

AbstractRecent advances in plant molecular biology have facilitated the introduction of novel traits into a range of plant species. It is now possible to modify the fatty acid composition of plant oilseeds, which opens up the possibility of improving the nutritional qualities of plant oils. The fatty acid composition of an oilseed determines its end use and therefore its commercial value. Value can be added to certain crop species by manipulations which would allow production of rare and valuable oils. Genetic engineering also provides novel opportunities for the production of pharmaceutical fatty acids such as γ‐linolenic acid and arachidonic acid which are important for human health and nutrition.© 2001 Society of Chemical Industry
Cyclin D1 overexpression as a prognostic factor in patients with esophageal carcinoma
Authors: Nagasawa Shigenao , Onda Masahiko , Sasajima Koji , Makino Hiroshi , Yamashita Kiyohiko , Takubo Kaiyo , Miyashita Masao 
Published: August 2002

AbstractBackground and ObjectivesCyclin D1 is known to play important roles in the G1/S check‐point of the cell cycle. We investigated the correlation between cyclin D1 overexpression and clinical characteristics to clarify its prognostic significance in patients with esophageal cancer.MethodsFrom 1991 to 1998, cyclin D1 was investigated in esophageal cancers from 86 patients who underwent esophagectomy. Overexpression of cyclin D1 was demonstrated using an immunohistochemical method.ResultsOverexpression of cyclin D1 was found in 23 (26.7%) of 86 cases. Overexpression of cyclin D1 correlated with lymph node metastasis (P = 0.0083) and lymphatic vessel invasion (P = 0.018). Cyclin D1 overexpression may indicate resistance to chemotherapy. The patients with cyclin D1 overexpression had a significantly lower survival rate than those without overexpression (P = 0.013). The multivariate analysis revealed cyclin D1 overexpression to be an important prognostic factor in patients with esophageal cancer.ConclusionsImmunohistochemical examination of cyclin D1 expression may provide important prognostic information in univariate and multivariate analysis and may be necessary for determining therapeutic strategies for esophageal cancer. J. Surg. Oncol. 2001;78:208–214. © 2001 Wiley‐Liss, Inc.
Trace elements content in serum, normal skin, and scar tissues of keloid and normal scar patients
Authors: Bang Rameshwar L. , Al‐Bader Abdul Latif , Sharma Prem N , Mattapallil Alice Babu , Behbehani Abdulla I. , Dashti Hussein 
Published: August 2002

AbstractWound healing is a normal physiological process that occurs after injury. Scars are usually formed, and the nature of the scar depends on the balance between the formed and degraded collagen during healing. A balanced production and degradation of collagen in wound healing results in the formation of a normal scar whereas an imbalance produces what is known as keloid scar. The factors that cause an imbalance are not well identified, although many factors, such as immunity, genetic, ischaemia, hormonal, growth, and nutritional factors, are blamed. This study was undertaken to investigate trace elements level in the serum, normal skin, and scar tissue of patients with normal and keloid scars. Copper (Cu), zinc (Zn), selenium (Se), and manganese (Mn) levels were estimated in 100 (50 with normal scars and the others with keloids) patients. The serum level of Zn was found to be higher in keloid scar patients, and this increase was highly significant (P < 0.0001). The level of Cu was significantly higher (P < 0.0001) in the normal skin and scar tissues of keloid patients. Trace element levels in scar tissues were observed to be lower in comparison to normal skin trace element content in both groups. The significant changes of Zn in serum and Cu in skin and scar tissues of keloid patients as noted in this study may suggest their role in the regulation of behavior of scar formation in wound healing. J. Trace Elem. Exp. Med. 15:57–66, 2002. © 2002 Wiley‐Liss, Inc.
Kinetics of the cyclopentadiene decay and the recombination of cyclopentadienyl radicals with H‐atoms: Enthalpy of formation of the cyclopentadienyl radical
Authors: Roy K. , Braun‐Unkhoff M. , Frank P. , Just Th. 
Published: August 2002

AbstractThe recombination of c‐C5H5 with H‐atoms has been studied behind reflected shock waves. The obtained rate coefficients are almost independent of temperature and were found to be krec = 2.6 × 1014 cm3 mol−1 s−1 for pressures around 2 bar in the temperature range between 1150 and 1500 K. Together with rate coefficients for the dissociation, obtained in an earlier work (Roy et al., Proc Combust Inst 1998, 27, 329–336) at pressures and temperatures close to those applied in the present work, we calculated equilibrium constants Kc(T) for C5H6 ⇌ c‐C5H5 + H. A “third law” analysis was performed. Data for the enthalpy of formation of cyclopentadienyl DHf,0 = 65.4 ± 1 kcal mol−1 and DHf,298 = 62.5 ± 1 kcal mol−1 were derived, respectively. The analysis was based upon new results on the entropy of cyclopentadienyl, recently calculated by Kiefer et al. (J phy chem, in press). Finally, our measured data were subjected to a fall‐off analysis. The simulation turned out very satisfactorily. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 821–833, 2001
Experimental and modeling study of the oxidation of 1‐butyne and 2‐butyne
Authors: Belmekki N. , Glaude P. A. , Da Costa I. , Fournet R. , Battin‐Leclerc F. 
Published: August 2002

AbstractIgnition delays were measured behind shock waves in the cases of hydrocarbon–oxygen–argon mixtures containing 1‐butyne or 2‐butyne (1 or 2% of hydrocarbons for equivalence ratios from 0.5 to 2). Reflected shock waves permitted to obtain temperatures from 1100 to 1600 K and pressures from 6.3 to 9.1 atm.A detailed mechanism of the reactions of 1‐butyne and 2‐butyne has been explained in the line of the mechanism developed previously for the reaction of C3–C4 unsaturated hydrocarbons (propyne, allene, 1,3‐butadiene) [Int J chem Kin 1999, 31, 361]. It is based on the most recent kinetic data values published in the literature and is consistent with thermochemistry.This mechanism has been validated by comparing the results of our simulations to the experimental results obtained for ignition delays in our shock tube and to measurements of species obtained during thermal decomposition [Int J Chem Kin 1995, 27, 321; J Phys Chem 1993, 97, 10977]. The main reaction pathways have been derived from flow‐rate and sensitivity analyses. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 172–183, 2002; DOI 10.1002/kin.10035
Catalytic hydrolysis of p‐nitrophenyl picolinate by copper(II) and zinc(II) complexes of N‐(2‐deoxy‐β‐D‐glucopyranosyl‐2‐salicylaldimino)
Authors: Yan Xiang , Zeng Xiancheng , Cheng Siqing , Li Yantuan , Xie Jiaqing 
Published: August 2002

AbstractD‐glucosamine Schiff base N‐(2‐deoxy‐β‐D‐glucopyranosyl‐2‐salicylaldimino) and its Cu(II) and Zn(II) complexes were synthesized and characterized. The hydrolysis of p‐nitrophenyl picolinate (PNPP) catalyzed by ligand and complexes was investigated kinetically by observing the rates of the release of p‐nitrophenol in the aqueous buffers at 25°C and different pHs. The scheme for reaction acting mode involving a ternary complex composed of ligand, metal ion, and substrate was established and the reaction mechanisms were discussed by metal–hydroxyl and Lewis acid mechanisms. The experimental results indicated that the complexes, especially the Cu(II) complex, efficiently catalyzed the hydrolysis of PNPP. The catalytic reactivity of the Zn(II) complex was much smaller than the Cu(II) complex. The rate constant kN showing the catalytic reactivity of the Cu(II) complex was determined to be 0.299 s−1 (at pH 8.02) in the buffer. The pKa of hydroxyl group of the ternary complex was determined to be 7.86 for the Cu(II) complex. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 345–350, 2002
Kinetics and mechanism for the H‐for‐X exchange process in the H + C6H5X reactions: A computational study
Authors: Tokmakov I. V. , Lin M. C. 
Published: August 2002

AbstractThe addition of H atoms to benzene and toluene and subsequent transformations were investigated using high level ab initio and density functional theory methods. Molecular structures and vibrational frequencies calculated at the B3LYP/6‐311++G(d,p) level of theory were used in combination with adjusted G2M energetic parameters for RRKM rate constant calculations. Standard heats of formation for cyclohexadienyl and cyclohexadienyl, 6‐methyl radicals calculated through isodesmic reactions amounted to 49.5 ± 2 and 42.9 ± 3 kcal/mol, respectively. Rate constants for various elementary reactions involved in the H‐for‐X exchange (X = D, CH3) were calculated and closely correlated with the available experimental kinetic data. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 633–653, 2001