bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anticonvulsant Activities of the FS‐1 Subfraction Isolated from Roots of Delphinium denudatum
Authors: Raza Mohsin , Shaheen Farzana , Choudhary M. I. , Suria Amin , Rahman Atta‐ur‐ , Sombati Sompong , DeLorenzo R. J. 
Published: August 2002

AbstractDelphinium denudatum Wall. (Ranunculaceae) is a medicinal herb used for the treatment of epilepsy in the subcontinent. The present study reports the anticonvulsant activities in the maximal electroshock test (MEST) and subcutaneous pentylenetetrazole (PTZ), bicuculline (BIC), picrotoxin (PIC)‐induced seizures of the FS‐1 subfraction (FS‐1) that was obtained by purification of an aqueous fraction isolated from the roots of D. denudatum. In CF 1 mice, FS‐1 (600 mg/kg i.p.) exhibited very potent anticonvulsant activity that was comparable to the effects of the well‐known antiepileptic drug phenytoin (20 mg/kg) in MEST and protected 100% animals from hind limb tonic extension phase of this model. FS‐1 also suppressed PTZ‐induced threshold seizure and the loss of the righting reflex with tonic fore and hind limb extension by 100%, similar to the antiepileptic drug valproic acid (350 mg/kg). BIC‐induced seizures were suppressed in 80% of the animals. FS‐1 exhibited weak anticonvulsant effect on PIC‐induced seizures, however, it significantly reduced mortality and delayed the onset of seizures. FS‐1 had no effect on strychnine (STN)‐induced extensor seizures. The results demonstrate the broad and potent anticonvulsant activity of the compounds in FS‐1 of D. denudatum. Copyright © 2001 John Wiley & Sons, Ltd.
Coleonema album: studies of the pharmacological action on smooth muscle in vitro and antimicrobial action of its essential oil
Authors: Lis‐Balchin Maria , Hart Stephen L. 
Published: August 2002

AbstractThe mode of action of the essential oil of Coleonema album, a South African species from the Cape region, was studied on smooth muscle in vitro using field‐stimulated guinea‐pig ileum. The oil produced an initial spasmogenic activity followed by spasmolysis, both actions being dose‐dependent. The spasmolytic action was post‐synaptic and not atropine‐like and was unaffected by the adrenoceptor blockers phentolamine and propranolol. There was no evidence for the involvement of either cyclic guanosine monophosphate or cyclic adenosine monophosphate in the spasmolytic activity. The oil had some calcium channel blocking activity but this is not the primary explanation for its spasmolytic response.Antimicrobial activity against Pseudomonas aeruginosa, Escherichia coli, Staphyloccocus aureus and Saccharomyces cerevisiae was very low and totally absent against Enterococcus hirae, suggesting that the oil has no worthwhile potential in this area. However, as the oil has a very disagreeable odour in its undiluted form, it could be a powerful insect repellent, as its local usage suggests, and this remains to be investigated. Copyright © 2002 John Wiley & Sons, Ltd.
A fraction defective based capability index
Authors: Borges Wagner de Souza , Ho Linda Lee 
Published: August 2002

AbstractTwo problems greatly affect the use of capability indices such as $C_p$, $C_{pk}$ and $C_{pkm}$: the lack of affinity with the process fraction defective π and the difficulty of dealing with the sampling distributions of their natural estimators. In this paper, a capability index which is in one‐to‐one correspondence with π is introduced and simple inferential procedures under a Bayesian perspective are developed to facilitate its use in industrial applications. Copyright © 2001 John Wiley & Sons, Ltd.
Incorporation of solvent effects into density functional predictions of molecular polarizabilities and hyperpolarizabilities
Authors: Zhu Weihua , Wu Guo‐Shi , Jiang Yuansheng 
Published: August 2002

AbstractA study of the effect of the field, the basis set, the functional, and the cavity size on molecular polarizabilities and hyperpolarizabilities of substituted benzenes in liquid or solution is reported. The calculations have been performed using the density functional theory (DFT) within the conductor‐like screening model (COSMO). The optimized computational parameters are adopted to calculate molecular polarizabilities and hyperpolarizabilities of substituted benzenes in liquid or solution. The results show good agreement with the experimental values. From comparison of the different theoretical results, it is found that at the same theoretical level, the selection of the different solvation models may play an important role in the calculations of molecular solvation polarizability, and using the same solvation model, the effects of the different theoretical methods are relatively small. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Electron correlation effects in ionic hydrogen clusters
Authors: Bokes P. , Štich I. , Mitas L. 
Published: August 2002

AbstractWe employ density functional, post‐Hartree–Fock, and quantum Monte Carlo methods to study the electronic structure, geometries, and behavior of positively charged Hm+ clusters with m=3,5,…,17. Their structure consists of a tightly bound H3+ core ion surrounded by successive solvation shells of H2 molecules. For the largest clusters, we propose new geometries. We find that correlated methods yield the stepwise decrease of enthalpies for dissociation of H2 from the clusters observed in experiments. Our best results are obtained by the diffusion Monte Carlo method, and by including finite temperature entropic effects, we are able to reproduce the experimental dissociation enthalpies with an unprecedented accuracy of less than 0.5 kcal/mol. These benchmark results contrast with erroneous predictions discovered in the density functional approaches. Finally, our analysis of the cluster energy surfaces indicates that under quantum and thermal fluctuations, the outer solvation shells will exhibit pronounced fluctional behavior. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 86–95, 2001
Quantum mode phonon forces between chainmolecules
Authors: Bohr Jakob 
Published: August 2002

AbstractA phenomenological description of the contributions of phonons to molecular force is developed. It uses an approximation to consider macromolecules as solid continua. The molecular modes of a molecule can then be characterized by a Debye‐like description of the partition function. The resulting bimolecular interaction is a truly many‐body force that is temperature dependent and can be of the order of 1 eV. These phonon forces depend on molecular shape, composition, and density. They may therefore also be important for large molecular conformational changes, including the unfolding of chain molecules. For the later case, a significant change in zero‐point energy is found. This may be the underlying cause for cold denaturation of proteins. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem 84: 249–252, 2001
Noncollinear spin density functional theory for spin‐frustrated and spin‐degenerate systems
Authors: Yamanaka S. , Yamaki D. , Shigeta Y. , Nagao H. , Yamaguchi K. 
Published: August 2002

AbstractWe have implemented ab initio linear combinations of Gaussian‐type orbital calculations with generalized localized spin density approximation (GLSDA) for a dimer of equilateral H3 as a model of the noncollinear magnetic clusters. It has been found that the GLSDA solution with the three‐dimensional noncollinear spin structure is, contrary to prior band calculations by other groups, the ground state near the Oh conformation. Further computational results are compared to that of ab initio generalized Hartree–Fock. The difference between them and the influence of the correlation correction were discussed. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
A cylindrical capacitor ionization source: droplet generation and controlled charge reduction for mass spectrometry
Authors: Ebeling Daniel D. , Westphall Michael S. , Scalf Mark , Smith Lloyd M. 
Published: August 2002

AbstractA cylindrical capacitor ionization source was used in conjunction with corona discharge charge reduction for generation of singly charged ions for mass spectrometric analysis. The source consists of a fused‐silica capillary threaded with a platinum wire and placed inside a stainless steel tube. Application of an electric potential to the wire results in the production of a linear stream of charged droplets when an aqueous solution is pumped through the capillary. Subsequent solvent evaporation yields ions, providing a continuous ion source for mass spectrometry. Passage of the ions through a corona discharge charge reduction chamber permits reduction of the charge state to predominantly singly charged species, facilitating analysis of DNA and protein mixtures. The change from production of multiply charged ions to production of singly charged ions is extremely simple, requiring only modulation of the voltage applied to the corona discharge electrode. A simple technique for construction of the ionization source is reported. Copyright © 2001 John Wiley & Sons, Ltd.
High‐throughput cytochrome P450 (CYP) inhibition screening via a cassette probe‐dosing strategy. VI. Simultaneous evaluation of inhibition potential of drugs on human hepatic isozymes CYP2A6, 3A4, 2C9, 2D6 and 2E1
Authors: Bu Hai‐Zhi , Magis Lisa , Knuth Kim , Teitelbaum Philip 
Published: August 2002

AbstractThe inhibition potential of drugs towards five major human hepatic cytochrome P450 (CYP) isozymes (CYP2A6, 3A4, 2C9, 2D6, and 2E1) was investigated via cassette dosing of the five probe substrates (coumarin, midazolam, tolbutamide, dextromethorphan, and chlorzoxazone) in human liver microsomes using a 96‐well plate format. After microsomal incubations had been terminated with formic acid, the five marker metabolites (7‐hydroxycoumarin, 1′‐hydroxymidazolam, 4‐hydroxytolbutamide, dextrorphan, and 6‐hydroxychlorzoxazone) were simultaneously quantified using direct injection/online guard cartridge extraction/tandem mass spectrometry (DI‐GCE/MS/MS). Several advantages resulted from the use of a short C18 guard cartridge (4 mm in length) for DI‐GCE/MS/MS, including minimal sample preparation, fast online extraction, short analysis time (2.5 min), and minimal source contamination. In addition, this method demonstrated an inter‐day accuracy range from −8.7 − 7.4% with a precision less than 8.3% for the quantification of all the marker metabolites. The inhibition assay for the five CYP isozymes was evaluated using their known selective inhibitors via individual and cassette dosing of the probe substrates. The IC50 values measured via cassette dosing were consistent with those observed via individual dosing, which were all in agreement with the reported values. In addition, the validated assay was used to evaluate the inhibitory potential of 23 generic drugs (randomly selected) towards the five CYP isozymes. The results suggest the integration of the cassette dosing strategy and the DI‐GCE/MS/MS method can provide a reliable in vitro approach to screening the inhibitory potential of new chemical entities, with maximal throughput and cost‐effectiveness, in support of drug discovery and development. Copyright © 2001 John Wiley & Sons, Ltd.
Ammonia chemical ionization tandem mass spectrometry in structural determination of alkaloids. II. Tetraponerines from pseudomyrmecine ants
Authors: Garraffo H. Martin , Spande Thomas F. , Jain Poonam , Kaneko Tetsuo , Jones Tappey H. , Blum Murray S. , Ali T. M. Musthak , Snelling Roy R. , Isbell Lynne A. , Robertson Hamish G. , Daly John W. 
Published: August 2002

AbstractChemical ionization tandem mass spectrometry (CI‐MS/MS) of alkaloids with ammonia reagent gas and collision‐activated dissociation as well as EI‐MS/MS were applied to the tetraponerine alkaloids in extracts from six pseudomyrmecine ants of the genus Tetraponera. The MS/MS techniques along with gas chromatography Fourier transform infrared (GC/FTIR) spectra allowed identification in two extracts of seven of the eight known tetraponerines. The EI‐MS/MS fragmentations proved diagnostic for the ring system and the CI‐MS/MS patterns for the C‐8 or C‐9 substitution, while the Bohlmann bands in FTIR spectra were diagnostic for the C‐8 or C‐9 configurations. An Indian ant (T. allaborans) had T–2, T–4 and T–8, while a Chinese ant (T. binghami) had T–5, T–6, T–7 and T–8. Four other ants, T. rufonigra (India), T. penzigi (Africa), T. clypeata (Africa) and T. sp. cf. emeryi (Africa), had no tetraponerines. Copyright © 2001 John Wiley & Sons, Ltd.
Direct determination of phosphorylated intracellular anabolites of stavudine (d4T) by liquid chromatography/tandem mass spectrometry
Authors: Pruvost Alain , Becher François , Bardouille Patrick , Guerrero Catherine , Creminon Christophe , Delfraissy Jean‐François , Goujard Cécile , Grassi Jacques , Benech Henri 
Published: August 2002

AbstractThe objective was to develop and validate a routine assay for active intracellular anabolites of stavudine (d4T), a nucleoside reverse transcriptase inhibitor in human PBMC, applicable to pharmacokinetic studies and treatment monitoring. This was achieved using liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS), which theoretically allies optimum sensitivity, specificity and high sample throughput. After cellular lysis in a Tris/methanol buffer, the extract spiked with 2[H8]‐ATP (internal standard) is directly injected into the LC/MS/MS system. Phosphorylated metabolites of d4T as well as deoxythymidine‐triphosphate, the competitor on the reverse transcriptase, are separated from d4T on a reverse‐phase microbore column with ion pairing. The detection is performed in the multiple reaction monitoring (MRM) mode after drug ionisation in negative mode electrospray. The limit of quantitation for d4T‐TP was 138 fmol per 7 mL blood (9.8 fmol per 106 cells) and CV% for repeatability and intermediate precision were lower than 15%. Stability of compounds was checked before and during the process of isolation of PBMC. Cellular samples from several d4T‐treated patients were successfully analysed using this method and d4T‐triphosphate and deoxythymidine triphosphate were recovered. In conclusion, we have developed and validated a routine LC/MS/MS method that allows the simultaneous determination of mono‐, di‐ and triphosphorylated anabolites of d4T in PBMC as well as the natural corresponding triphosphate in one analysis. For the first time, the chain terminator ratio (d4T‐TP/dT‐TP) could be directly measured. This method can be used simply and routinely on more than 35 samples per day. Extension to other nucleoside analogues is under development. Copyright © 2001 John Wiley & Sons, Ltd.
Structural analysis of oligosaccharides by atmospheric pressure matrix‐assisted laser desorption/ionisation quadrupole ion trap mass spectrometry
Authors: Creaser Colin S. , Reynolds James C. , Harvey David J. 
Published: August 2002

AbstractAn ion source incorporating a fibre optic interface has been constructed for atmospheric pressure matrix‐assisted laser desorption/ionisation quadrupole ion trap mass spectrometry. The configuration has been applied to the study of linear and complex oligosaccharides. Multi‐stage tandem mass spectrometry (MSn, n = 2–4) experiments carried out in the ion trap enable extended fragmentation pathways to be investigated that yield structural information. Collisional activation of sodiated oligosaccharides, as demonstrated on the model compound maltoheptaose, produces primarily B and Y fragments resulting from cleavage of glycosidic bonds; fragments from cross‐ring cleavages are also observed following further stages of tandem mass spectrometry, providing additional linkage information. The analyses of mixtures of complex oligosaccharides are demonstrated for N‐linked glycans from chicken egg glycoproteins and a ribonuclease glycan mixture. Mass spectrometric and tandem mass spectrometric data for sugars with molecular weights up to 4000 Da is shown for mixtures of linear dextrans and N‐linked glycans. The use of MSn (n = 3, 4) on these complex molecules enabled structural information to be elucidated that confirms data observed in the MS/MS spectra. Copyright © 2001 John Wiley & Sons, Ltd.
Quantitation in gradient high performance liquid chromatography/inductively coupled mass spectrometry investigated using diclofenac and chlorpromazine
Authors: Duckett Catherine J. , Bailey Nigel J. C. , Walker Heather , Abou‐Shakra Fadi , Wilson Ian D. , Lindon John C. , Nicholson Jeremy K. 
Published: August 2002

AbstractThe use of directly coupled high performance liquid chromatography/inductively coupled plasma mass spectroscopy (HPLC/ICPMS) employing chlorine (35Cl/37Cl) detection has been investigated with respect to the detection and quantitation of the drugs diclofenac and chlorpromazine. By integration of peak areas in the ‘chloratogram’ (the chlorine‐specific HPLC chromatogram), a calibration curve was constructed, from which the concentrations could be determined. Chlorine‐detected HPLC/ICPMS is quantitative over a wide range of concentrations of pharmaceutical relevance for metabolite detection and the results reproducible (standard deviation ± 0.43%) over multiple injections. Application of gradient chromatography and variation in the bulk mobile phase physicochemical properties has little effect on the ICPMS detection response for these compounds. This work indicates that the use of HPLC/ICPMS is likely to be quantitatively reliable for metabolism studies for a range of chlorinated xenobiotics. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular techniques should not now replace cell culture in diagnostic virology laboratories
Authors: Ogilvie Marie 
Published: August 2002

AbstractThe value of molecular techniques for virology is not in dispute; the issue debated here is whether or not to abandon virus isolation altogether. Modern clinical virology relies on rapid virus detection for timely infection control and antiviral therapy. The role of virus isolation, inevitably a slower process as it involves replication in cell cultures, is most significant in providing epidemiological data, in the diagnosis of new or unexpected infection, and in yielding infectious virus for further study. Examples include identification of enterovirus serotypes in outbreaks, diagnosis of atypical virus infections, and provision of virus isolates for phenotypic antiviral susceptibility assays. Many viruses can be detected after overnight culture using the centrifugation‐enhanced (shell vial) technique. In contrast to this established track record, the commercial development of molecular assays has been concentrated on blood‐borne viruses, and standardisation of procedures for other viruses is lacking. Accreditation of molecular techniques is just beginning, and few external quality assurance schemes are available yet. In my view, it is premature to abandon routine virus isolation, although as molecular diagnosis expands, the facilities for cell culture and isolation work may become more centralised to retain expertise and to provide the range and quality of service required. Copyright © 2001 John Wiley & Sons, Ltd.
Flow management strategies to control blooms of the cyanobacterium, Anabaena circinalis, in the River Murray at Morgan, South Australia
Authors: Maier Holger R. , Burch Michael D. , Bormans Myriam 
Published: August 2002

AbstractThe Murray–Darling river system is highly regulated and is Australia's major surface water resource. It is subject to blooms of the toxic cyanobacterium Anabaena circinalis, which present significant water quality problems. As a result of these blooms, an algal management strategy has been developed for the Murray–Darling basin. One of the major objectives of the strategy is the development of flow management strategies for key reaches of the river system. Intensive studies in the Murrumbidgee River, Australia, have indicated that persistent thermal stratification is a requirement for blooms of this cyanobacterium to occur. In the lower Murray, mean wind speed was found to be the major factor affecting the degree of thermal stratification under low flow conditions, which generally exist during the months of December to March. In this paper, the effect of various flow management scenarios on the likelihood of the occurrence of blooms in the River Murray at Morgan, South Australia, are assessed. A frequency analysis is carried out on 30 years of wind speed data to determine the probability of occurrence of persistent thermal stratification under a number of flow regimes. The scenarios evaluated include existing base flow conditions, altered base flow regimes, temporary releases from an upstream storage (Lake Victoria) and the temporary reduction of weir pool levels. The results obtained indicate that the dispersal of existing blooms by simultaneously reducing the weir pool levels at Locks 1–3 is the most effective and economical strategy for combating bloom formation by A. circinalis in the River Murray at Morgan. Copyright © 2001 John Wiley & Sons, Ltd.
“It's harder than we thought it would be”: A comparative case study of expert–novice experimentation strategies
Authors: Hmelo‐Silver Cindy E. , Nagarajan Anandi , Day Roger S. 
Published: August 2002

AbstractScientific inquiry is a complex skill. Aspiring physicians need to learn these skills so that they can be educated consumers of medical research as well as being collaborators in different kinds of clinical trials. But school science often fails to provide the kind of authentic tasks needed to help students develop appropriate reasoning skills and epistemological beliefs. In this study, we compared a group of expert cancer researchers with four groups of fourth year medical students (the “novice” groups) engaged in the task of designing a clinical trial to test a new cancer drug using a computer‐based modeling tool, the Oncology Thinking Cap. Although the experts and novices reached similar endpoints, their reasoning processes differed considerably. For the experts, this was a task that required learning about the drug they were testing. The novices needed to learn about designing clinical trials, particularly about how variables interacted with each other, as well as learning about the drug. One of the major lessons learned by the novice student groups was just how complex clinical trial design really is. © 2002 Wiley Periodicals, Inc. Sci Ed 86:219–243, 2002; DOI 10.1002/sce.10002
The role of ideational networks in laboratory inquiry learning and knowledge of evolution among seventh grade students
Authors: Anderson O. Roger , Randle David , Covotsos Tom 
Published: August 2002

AbstractIdeational networks were assessed based on written narrative of seventh grade students who had begun a unit on evolution. The amount of ideational network linkages in narrative, elicited by showing the students a diagram of an evolutionary branching tree of life, was analyzed using flow‐map techniques. The number of network linkages in the students' narrative was positively correlated with mean scores on subsequent inquiry laboratory work on evolution (r = 0.5, p ≪ .01). final unit test score on knowledge of biological evolution (r = 0.35, p < .01), and the extent of correct conceptions about evolution contained in the students' written essays as determined by content analyses (r = 0.7, p ≪ .01). Students, who scored high on the content analyses of their written narrative and whose narrative contained extensive ideational network linkages, also tended to use a logical sequential rule of ordering their thoughts based on a phylogenetic principle of evolutionary change accompanying increasing complexity of life (i.e., progression from one‐celled organisms to complex multicelled organisms). Moreover, the mean frequency of occurrences of higher level categorical thought in narrative increased with increasing amount of ideational linkages in recall. © 2001 John Wiley & Sons, Inc. Sci Ed 85:410–425, 2001.