bluuebunny/crossref_metadata_2025_split huggingface dataset:
An improved method for hyaluronic acid radioiodination
Authors: Orlando P. , Binaglia L. , De Feo A. , Orlando M. , Trenta R. , Trevisi R. 
Published: October 2006

AbstractA simple procedure is described for preparing 125I‐labelling hyaluronan of high molecular weight. The reducing terminal group of hyaluronic acid was derivatized with tyramine through the formation of a Schiff base which was subsequently reduced with sodium cyanoborohydride.By radioiodination of the aromatic ring, 125I‐labelled hyaluronic acid was obtained in high yield (40%) and high specific activity, 555 GBq/mmol (15 Ci/mmol).
Pesticides labelled with 14C. II. Synthesis of propiconazole labelled in three different positions
Authors: Koltai Ernõ , Kling Ferenc , Rutkai György 
Published: October 2006

AbstractPropiconazole was labelled with 14C in three different positions: in the benzene ring, in the position 5 of the dioxolane ring, and in the triazole ring. The synthesis of three new key intermediates [(m‐dichloro[U‐14C]benzene], 1,2,4‐[U‐14C]triazole, [1‐14C]‐pentane‐1,2‐diol) were also elaborated.
A reinvestigation of the synthesis of [15N2]hydroxymethylimidazole: Useful in an improved synthesis of (D,L)‐[τ,π‐15N2]histidine
Authors: Silks Louis A. , Dunkle Erik , Ünkefer Clifford J. , Sudmeier James L. , Butler Michael , Bachovchin William W. 
Published: October 2006

AbstractWe have reinvestigated the synthesis of [15N2]hydroxymethyl imidazole from dihydroxyacetone, formaldehyde, and labelled ammonia in an attempt to optimize the yield from the isotope. Conversion of the hydroxymethyl imidazole to histidine was accomplished in good yield without the need for picric acid as an ion pairing agent.
Synthesis of [2‐{(4‐chlorophenyl) (4‐[125I]iodophenyl)} methoxyethyl]‐1‐piperidine‐3‐carboxylic acid, [125I]CIPCA: A potential radiotracer for GABA uptake sites
Authors: Van Dort Marcian E. , Gildersleeve David L. , Wieland Donald M. 
Published: October 2006

AbstractThe synthesis of racemic [2‐{(4‐Chlorophenyl) (4‐iodophenyl)} methoxyethyl]‐1‐piperidine‐3‐carboxylic acid, (CIPCA) and its radioiodinated analog [125ßI]CIPCA is described. CIPCA was synthesized from 4‐iodobenzoyl chloride in five steps in 16% overall yield. Ammonium sulfate catalyzed solid‐state isotopic exchange of CIPCA with Na125I provided [125I]CIPCA in 34% isolated radiochemical yield at a specific activity of 118 Ci/mmol. [125ICIPCA] demonstrated moderate brain extraction and good in vivo radiostability in preliminary biodistribution studies conducted in CD‐1 mice. [125I]CIPCA is a potentially useful radiotracer for study of the GABA uptake system.
Synthesis and characterization of tritium‐labeled RU486
Authors: Mais Dale E. , Chen Lian‐Zhi , Wagoner Murriel A. , Hayes J. Scott , Wang Ming‐Wei 
Published: October 2006

Abstract[3H]RU38486 (RU486) was synthesized from its penultimate precursor, desmethyl RU486, by substitution of the secondary amine with tritiated methyl iodide; specific activity 85 Ci/mmol. Ligand binding studies confirm that RU486 binds with high affinity to human progesterone receptor type A (PR‐A) and progesterone receptor type B (PR‐B).
Synthesis of three no‐carrier‐added O6‐4‐[125I] iodobenzylguanosine derivatives, new reagents for the assay of O6‐alkylguanine‐DNA alkyltransferase activity
Authors: Mounetou Emmanuelle , Cussac Catherine , Mathieu Frédérique , Maurizis Jean‐Claude , Labarre Pierre , Moreau Marie‐France , Veyre Annie , Madelmont Jean‐Claude 
Published: October 2006

AbstractO6‐alkylguanine‐DNA alkyltransferase (AGT) is mainly responsible for tumour resistances observed in chemotherapeutic treatments by chloroethylnitrosoureas (CENUs). Measurement of AGT activity is thereby essential to predict the response of the patients to therapy with CENUs. In order to develop a sensitive and easy new assay for AGT, previously undescribed O6‐4‐[125I]iodobenzyl‐2′‐deoxyguanosine, O6‐4‐ [125I]iodobenzyl‐N‐acetylguanosine and O6‐4‐[125I] iodobenzylguanosine labelled with high specific activity were prepared. The most convenient synthetic route appeared to be a rapid and high yield iododestannylation of a tri‐n‐butylstannyl derivative with no‐carrieradded sodium [125I] iodide. Final HPLC separation from the excess of precursor and unreacted [125I] iodides afforded the radioiodinated guanosine derivatives in yields ranging from 70 to 77 %, chemical and radiochemical purities averaging 99%.
Synthesis of 1‐3H‐3, 3‐dimethylallyl pyrophosphate
Authors: Cardemil E. , Cori O. 
Published: October 2006

Abstract3, 3‐Dimethylallyl pyrophosphate (DMAPP) Labeled with 3H on C‐1 was prepared from the corresponding acid by esterification, reduction of the methyl ester with LiAl3H4 and pyrophosphorylation of the radioactive alcohol.The products were purified by ion‐exchange chromatography, yielding a single radioactive compound. Phosphorus analysis and gas chromatography showed that the final product was DMAPP.
Preparation of 113Sn2+ and 113 Sn4+ compounds
Authors: Hiles Richard A. 
Published: October 2006

AbstractA need for valence‐pure 113Sn2+ and 113Sn4+ compounds required the development of the methods reported in this communication. Commercially available 113Sn comes either as metallic Sn which is contaminated with isotopes of Sn as well as with antimony and indium or as a hydrochloric acid solution of 113SnCl4 plus some 113SnCl2. The procedures reported here yield a chemically atable powder of 113SnSO4 which is greater than 98% in the Sn2+ form.There are two major advantages in preparing the 113SnSO4. First, many other113SnSO4+ compounds can be readily prepared by oxidizing an acidic solution of 113SnSO4 with hydrogen peroxide with no contamination of the resulting Sn4+ solution with oxidising agent. In contrast, the reduction of Sn4+ to 2+ salts is not easily accomplished. Second as polarographic evidence indicates, sulfate is a very weak complexer of Sn and thus many new salts of Sn can be prepared simply by mixing a selected new anion in to a solution containing 113SnSO4.
Die positionale markierung von N‐[1′‐phenyl‐Äthyl‐(1′)] ‐1, 1‐ diphenyl‐propyl‐(3)‐amin, HCL (137 HK)
Authors: Volford J. , Harsanyi K. 
Published: October 2006

AbstractAus 14CO2, bzw. K14CN ausgehend wurden das an dem Asymmetriezentrum, das in propyl‐Position C‐1 und das in Stellung C‐3 markierte 137 HK‐Racemat, fermer die Stellung C‐3 markierten (+)‐ und (−)‐Enantiomere dargestellt. Die molare Aktiuität der Produkte beträgt in der obigen Reihenfolge: 11.1; 10.5; 4.4 und die der opttisch aktiven 3.5 mCi/mMol, die radichemische Reinheit der Produkte beträgt mindesten 98%. Die optische Reinheit wurde durch Drehungbestimmong, die chemische und radiochemische Reinheit durch IR‐spektroskopische und dünnschicht‐chromatographische Untersuchungen, ferner durch Verdünnungsanlyse Kontrolliert.
The preparation of carbon‐ 14 labeled tobacco constituents1. II. The synthesis of D1‐nicotine (2′‐14C)
Authors: Comes R. A. , Core M. T. , Edmonds M. D. , Edwards W. B. , Jenkins R. W. 
Published: October 2006

AbstractA 3‐step synthesis, of dl‐nicotine (21‐14C) is described. Commercially available nicotinamide (carbonyl‐14C) is dehydrated to 3‐cyanopyridine (cyano‐14C). Reaction of the 3‐cyanopyridine with cyclopropyl lithium yields 3‐pyridyl cyclopropyl ketone (carbonyl‐14C) which is converted to dl‐nicotine (21‐14C) by refluring in N‐methyl formamide. Gas‐liquid radio‐chromatography is used for cheimical and radiochemical purity determinations.
Synthesis of methyl trans‐(10‐ 14C)‐retinoate and trans‐(10‐ 14C)‐retinol
Authors: Bu'Lock J. D. , Quarrie S. A. , Taylor D. A. 
Published: October 2006

AbstractThe preparation of the title compunds, using β‐ionone, is accomplished in fair overall radiochemical yield from (2‐14C) bromacetic acid, in 7 and 8 steps respectively. The sequence utilises ylid reactions of the phosphonoacetate derived from bromacetic ester, and is also capable of the introduction of label at C‐14.
The synthesis of N‐nitrosohexamethyleneimine labeled with 14C in the 2‐position
Authors: Granjean C. J. , Nagel D. L. , Wallcave L. , Phelps K. , Charnock G. 
Published: October 2006

AbstractA synthetic procedure for 2‐14C‐N‐nitrosohexamethyl‐eneimine 1‐aza‐l‐nitroso‐(2‐14C)‐cycloheptane is presented. The starting material was 1‐14 C‐cyclohexanone which underwent ring expansion, reduction, and finally nitrosation. The synthesis resulted in a product in good yield (68% overall), which is chemically and radiochemically pure.
The biosynthetic prepartion of 1‐14C ‐trans‐11‐octadecenoic acid
Authors: Christie W. W. , Hunter M. L. , Harfoot C. G. 
Published: October 2006

Abstractl‐14C‐Trans‐11‐octadecenoic acid was obtained in 60% overall yield by incubating 1‐14C ‐linoleic acid with sheep rumen microorganisms. The product, purified in the form of the methyl ester by silver nitrate chromatography, contained small amounts of related positional isomere as the only impurities.
Synthesis of 1, 4‐bis(3′‐bromopropionyl)‐piperazine‐2, 3‐14C via piperazine‐2, 3‐14C
Authors: Kagemoto Akira , Kishi Masataka , Minaki Yasuo , Nakamura Kiyoshi 
Published: October 2006

AbstractA simple procedure to synthesize 1, 4‐bis (3′‐bromopropionyl) piperazine‐2, 3‐14C, pipobroman‐14C(I‐14C), via piperazine‐2, 3‐14C (V‐14C) was described.The condensation of 1, 2‐bis(bensy lamino) ethane(II) with ethylene dibromide‐1, 2‐14C gave 1, 4‐dibensylpiperazine‐2, 3‐14C(III‐14C) in 34% yield. III‐14C was catalytically reduced in glacial acetic acid on Pd‐C to afford piperazine‐2, 3‐14C diacetate (IV‐14C) in 90% yield, followed by the conversion in aqueous solution to free V‐14C which was in turn subjected to a Schotten‐Bauman reaction with 3‐bromopropionyl chloride to give I‐14C in 69% yield.
Syntheses of 2(IH)‐quinazolinone‐4‐14C derivatives
Authors: Yoshitake A. , Makari Y. , Kawahara  , Endo M. 
Published: October 2006

AbstractL‐Cyelopropy lmethyl‐6‐methoxy‐4‐phenyl‐2 (1H)‐qiomazpmpme (III) (SL‐573) and l‐Cyclopropylmethyl‐6‐nitro‐4‐phenyl‐2( 1H )‐quinazolinone (VI) (SL‐522), each labelled with carbon ‐14 at C‐4 position were synthesized for use in metabolic studies. The syntheses were achieved by two types of reaction sequences shown in Figure 1 and 2. Overall radiochemical yields of SL‐573‐4‐14C and SL‐522‐4‐14C were 35% and 17% from carbon dioxide‐14C. and their specific activities were 5.52 mCi/mmole and 3.31 mCi/mmole, respectively.
Lithiation des derives silyles du desoxy‐2′‐uridine monophosphate‐5′ (dUMP) et du bromo‐5‐desoxy‐2′‐uridine monophosphate‐5′ (BR‐5 dUmp), preparation de thymidine (methyl14C) ‐monophosphate‐5′ (TMP)
Authors: Pichat L. , Herbert J. Godbillon M. 
Published: October 2006

AbstractLa méthyl‐6‐désoxyuridine monophosphate‐5′ est le produit prépondérant de la méthylation du dérivé lithié de l'eser bis (triméthylsilylé) del′acide 0‐triméthylsily‐3′‐désoxyridylique avec un rendement de 24% par rapport à 14CH3I. La thymidine monophosphate‐5′ (méthyl 14C) peut être obtenue avec un rendement de 30% à partir du bromo‐5 nucléotide correspondant.
Development of specifications for labelled mucleotides and related compounds, specific activity measurements dy mass spectrometry
Authors: Goldstein Gerald , Rainey W. T. 
Published: October 2006

AbstractThe National Academy of Science‐National Research Council Committee on Specifications and Criteria for Biochemical Compounds is considering the problems involved in preparing specifications for labelled biochemicals. The Subcommittee on Nucleotides and Related Compounds has examined methods for specific activity measurement. We find that the specific activity of 14C‐labelled purines and pyrimidines can be determined accurately and precisely by mass spectrometry. Moreover, from the known fragmentation patterns and the isotopic abundance of carbon‐14 in the fragments, the position of the labelled atoms can often be established and the labelling pattern in “uniformly labelled” compunds described. In two of the five compounds tested, the specific activity determined by mass spectrometry was 20% higher than the quoted value.
An unusual cause of susceptibility artifact in magnetic resonance imaging
Authors: Cook Stephen C. , Shull Jennifer , Pickworth‐Pierce Kerry , Farra Yasser , Simonetti Orlando P. , Raman Subha V. 
Published: October 2006

AbstractMagnetic susceptibility artifact has been documented with various implants and devices, which require appropriate identification with screening of patients prior to subjecting them to magnetic resonance examination. We performed cardiovascular magnetic resonance (CMR) examination of the aorta in a 24‐year‐old woman in the setting of repaired aortic coarctation, and found magnetic susceptibility artifact arising from the stomach in the absence of known susceptibility artifact‐producing material in this region. Further history revealed that she had ingested a prenatal vitamin prior to imaging, prompting experimental analyses that led us to conclude that iron‐containing vitamins may be a source of magnetic susceptibility artifact. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Multi‐Component Kinetic Modeling for Controlling Local Compositions in Thermosensitive Polymers
Authors: Hoare Todd , McLean Daniel 
Published: October 2006

AbstractSummary: An explicit terminal copolymerization kinetic model accounting for the copolymerization of up to four different comonomers is developed and applied to model the conversion profiles and local compositional gradients in functionalized PNIPAM‐based polymer and hydrogel systems. The kinetics of the functional comonomer(s) have a large influence on both the mole fraction and chain distribution of functional groups in polymers. Strategies are developed to synthesize polymers with uniform compositions by applying semi‐batch techniques or via copolymerization of multiple monomers with the same target functionality but with divergent reactivities relative to NIPAM. Synthetic protocols are also designed to maximize the compositional uniformity and randomness of ampholytic polymers.Instantaneous mole fractions of monomers in polymers as a function of the overall monomer conversion for the copolymerizations of NIPAM, MBA, and two functional monomers: MMA and acrylamide.magnified imageInstantaneous mole fractions of monomers in polymers as a function of the overall monomer conversion for the copolymerizations of NIPAM, MBA, and two functional monomers: MMA and acrylamide.
Quantifying Fluid Mixing with the Shannon Entropy
Authors: Camesasca Marco , Kaufman Miron , Manas‐Zloczower Ica 
Published: October 2006

AbstractSummary: We introduce a methodology to quantify the quality of mixing in various systems, including polymeric ones, by adapting the Shannon information entropy. For illustrative purposes we use particle advection of two species in a two‐dimensional cavity flow. We compute the entropy by using the probability of finding a suitable chosen group/complex of particles of a given species, at a given location. By choosing the size of the group to be in direct proportion to the overall concentration of the components in the mixture we ensure that the entropic measure is maximized for the case of perfect mixing, that is, when at each location the component concentration is equal to the corresponding overall component concentrations. The scale of observation role in evaluating mixing is analyzed using the entropic methodology. We also illustrate the effect of initial conditions on mixing in a laminar system, typical in operations involving polymers.
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Total antioxidant capacity of spices, dried fruits, nuts, pulses, cereals and sweets consumed in Italy assessed by three different in vitro assays
Authors: Pellegrini Nicoletta , Serafini Mauro , Salvatore Sara , Del Rio Daniele , Bianchi Marta , Brighenti Furio 
Published: October 2006

AbstractWith the aim to expand the Italian total antioxidant capacity (TAC) database, the TAC values of 11 spices, 5 dried fruits, 7 sweets, 18 cereal products, 5 pulses, and 6 nuts were determined using three different assays and considering the contribution of bound antioxidant compounds in fiber‐rich foods (i. e. cereals, legumes, and nuts). Among spices, saffron displayed the highest antioxidant capacity, whereas among dried fruits, prune exhibited the highest value. The TAC values of all the chocolates analyzed were far higher than the other sweet extracts measured. Among cereal products, whole meal buckwheat and wheat bran had the greatest TAC. Among pulses and nuts, broad bean, lentil and walnuts had the highest antioxidant capacity, whereas chickpeas, pine nuts and peanuts were less effective. The contribution of bound phytochemicals to the overall TAC was relevant in cereals as well as in nuts and pulses. The complete TAC database could be utilized to properly investigate the role of dietary antioxidants in disease prevention.
Free radical scavenging and cytoprotective activities of phenolic antioxidants
Authors: Zhang Jingli , Stanley Roger A. , Adaim Aselle , Melton Laurence D. , Skinner Margot A. 
Published: October 2006

AbstractThe free radical scavenging activities of three flavonoids (quercetin, rutin and catechin) and four hydroxycinnamic acids (caffeic, ferulic, sinapic, and chlorogenic acids) were evaluated using both oxygen radical absorbance capacity (ORAC) and lipid peroxidation inhibition capacity (LPIC) assays. The cytoprotective effects of these compounds were also measured by the degree of protection against H2O2‐induced damage of human Jurkat cells. All compounds exhibited protection against H2O2‐mediated cytotoxicity in a dose‐dependent manner. The concentrations required to result in a 50% reduction in cell death (EC50 value) were calculated from their dose‐response curves. These ranged from 0.15–2.65 μM. Overall, the four hydroxycinnamic acids tested were less effective than the three flavonoids, and of all compounds tested, quercetin offered the strongest protection against H2O2‐induced cell death. A comparison of the results showed that the ability to inhibit peroxidation of lipids in a liposomal system (LPIC) correlated well with the cytoprotective activities (EC50), but not with the ability to protect an aqueous fluorescent substrate in the ORAC assays. The results suggest that the behavior of antioxidants in a liposomal membrane is to some extent similar to the mechanism involved in the protection of living cells from oxidative damage.
Respiratory symptoms in a boy revealing Carney triad
Authors: Delemarre Luçan , Aronson Daniel , van Rijn Rick , Bras Hans , Arets Bert , Verschuur Arnauld 
Published: October 2006

AbstractThe association of gastrointestinal stromal cell tumor (GIST), paraganglioma, and pulmonary chondroma is known as the Carney triad, occurring predominantly in young adult females. We present the case of a 14‐year‐old male with respiratory symptoms resulting in the diagnosis Carney triad. Pediatr Blood Cancer 2008;50:399–401. © 2006 Wiley‐Liss, Inc.
QSAR of Steroids
Authors: Zeelen F. J. 
Published: October 2006

AbstractProblems, specific for QSAR studies of steroids, are reviewed. The attention is drawn to the extensive use of X‐ray structure determinations to assist in weeding‐out chance correlations which arise from the need to use too small series of derivatives and the tendency in older studies to underestimate the flexibility of steroids.A series of papers on the QSAR of the cardiac glycosides illustrate some problems associated with the use of molecular modelling.
Science as doctrine or thought? A critical study of nine academic year institutes
Authors: Gruber Howard E. 
Published: October 2006

AbstractThis study of nine Academic Year Institutes in the United States was supported by the National Science Foundation following an earlier study of an A Y1 at the University of Colorado. For a more detailed report of the methods and results of this study, see H. E. Gruber, “Science as Thought: A Study of Nine Academic Year Institutes,” University of Colorado Behavior Research Laboratory Report No. 16 (1961).
Educational research related to science instruction for the elementary and junior high school: A review and commentary
Authors: Smith Herbert A. 
Published: October 2006

AbstractIn the summer of 1962, Professor Herbert Smith of Pennsylvania State University was requested by the Commission on Science Education of the American Association for the Advancement of Science to prepare a paper summarizing reports of the most significant educational research relating to the teaching of elementary school and junior high school science. The purpose of this project was to make available to members of the Commission and others interested in the current efforts to improve science education the results of that research which has influenced most heavily current educational practice and which should therefore be of interest to those seeking to change present practice. A draft of the report was used by participants in the writing session held under the auspices of the AAAS Commission on Science Education at Stanford University in the summer of 1963. The JRST has agreed to assist in efforts to bring Dr. Smith's paper to the attention of the science education community and the Commission has expressed appreciation to the JRST for this service. The opinions expressed do not necessarily represent AAAS, its Commission on Science Education, or the JRST. Reprints are available from the Editor, Department of Science Education, The Florida State University, Tallahassee, Florida, at a cost of $0.50 per copy.
Predicting achievement in chemistry: A model
Authors: Jones Kenneth J. 
Published: October 2006

AbstractThe author of this research report states that the primary value in such an analysis is that the investigator is forced to define the learning outcomes desired and to weigh carefully their relative values. It is presented here as a research model—a demonstration of statistical analysis in the solution of a problem in science education. Computations for this study were done in part at the Massachusetts Institute of Technology and Harvard Computating Center.
The princeton junior high school science project
Authors: Ferris Frederick L. 
Published: October 2006

AbstractThe author of this article is well known as the person who was primarily responsible for developing the tests which accompanied the new secondary school curricula (PSSC Physics et al). He has recently returned to geology, the field in which he took his doctorate, and as a member of the Geology Department at Princeton, is presently devoting full time to science curriculum development. Dr. Ferris serves as director of the project described in this article.
Conservation aspects of the concept of time in primary school children
Authors: Murray Frank B. 
Published: October 2006

AbstractSixty‐two second‐, fourth‐, and sixth‐graders were asked to judge the temporal duration of objects and events when the objects were changed in height or subjected to decay, when an event was reversed, and when an event was given an affective dimension. Nonconservers of time were those who judged that these irrelevant transformations affected the temporal aspects of the objects or events. The shift from nonconservation to conservation of time occurred between the second and fourth grades for most problems. The results indicated that young (under eight or nine years) children's concept of time is surprisingly defective. The relation of these findings to other conservation concepts was discussed.
A regression approach to evaluating instructional programs in science
Authors: Grobe Cary H. 
Published: October 2006

AbstractThis paper discussed a multiple linear regression approach to the evaluation of instructional strategies in science. A treatment by levels experimental design and the methods required for forming and solving research problems associated with it were described.Two methods of college biology instruction, the Audio‐Tutorial and conventional techniques, were compared in terms of promoting achievement. Methods for making comparisons between the two treatments in the form of linear models were discussed. Interpreting regression solutions to linear models was also presented.The principles expressed in this paper can be applied to other research problems as an effective alternative to the two‐way analysis of variance.