bluuebunny/crossref_metadata_2025 huggingface dataset:
Tritium Labelled 1‐O‐Octadecyl‐2‐O‐methyl‐rac‐glycero‐3‐phosphocholine (ALP) and 1‐S‐Hexadecyl‐2‐O‐ethyl‐rac‐thioglycero‐3‐phosphocholine (Thio‐ALP)
Authors: Wyrick Steven D. , Surles Jefferson R. , Morris‐Natschke Susan , Piantadosi Claude , Modest Edward J.
Published: October 2006

The phospholipids, ALP and Thio‐ALP, are non‐hydrolyzable analogues of platelet activating factor (PAF). Interest in ALP and thio‐ALP centers upon their activity as potential antineo‐plastic agents. A variety of mechanisms of action have been attributed to these compounds including inhibition of a phospholipid cofactor of a phospholipid sensitive Ca+2‐dependent protein kinase. Thio‐ALP is at least as active as a growth inhibitor of the HL‐60 promyelocytic leukemic cell line as is ALP‐the most active reference analogue reported in the literature and is approximately twice as active against the BG‐1 and BG‐3 human ovarian carcinoma cell lines. To aid in further biochemical studies, we report the synthesis of high specific activity tritium labelled ALP and thio‐ALP. These products were obtained by palladium catalyzed reduction of 1‐0‐octadecenyl and l‐S‐hexadecenyl precursors with carri'er‐free tritium gas.
Synthesis of adinazolam mesylate multiply labeled with carbon‐13 and deuterium
Authors: Hsi Richard S. P. , Stelzer Lindsay S.
Published: October 2006

Adinazolam mesylate labeled with stable isotopes was synthesized for conducting bioavailability studies. Adinazolam labeled uniformly with carbon‐13, >99% enrichment, in the unsubstituted phenyl ring was prepared for administration as drug. In addition, adinazolam was also dual‐labeled with carbon‐13, as in the drug, and with deuterium, six atoms per molecule, in the N‐methyl groups. The double‐labeled material was prepared for use as an internal standard in the mass spectral assay procedure to be employed in the study.
d,l‐6a‐13C‐Glaucine 1.5 phosphate
Authors: Henton Daniel R. , Goralski Christian T. , Heeschen Jerry P. , Nyquist Richard A. , Pfeiffer Curtis D.
Published: October 2006

d, l‐Glaucine 1.5 H3PO4, is a non‐narcotic antitussive for which a sample of carbon‐13 labelled material was required for metabolism studies in humans. The sample of 99% enriched d, l‐6a‐13C‐glaucine 1.5 H3PO4 was prepared in 7 steps in 36% overall yield starting with purchased 99% enriched 1‐13C‐papaverine. The papaverine was N‐methylated with methyl iodide and the resulting methiodide reduced to d, l‐1‐13C‐laudanosine with sodium borohydride. The laudanosine was O‐demethylated with 48% HBr and cyclized to d, l‐6a‐13C‐1,2,9,10‐tetrahydroxyaporphine (THA) using aqueous ferric chloride/sodium acetate and isolated as the hydrochloride salt (THA ± HCl). The THA ± HCl was converted to the free base and remethylated with phenyltrimethylammonium hydroxide. The resulting d, l‐6a‐13C‐glaucine was purified by column chromatography and isolated as the hydrobromide salt. The d, l‐6a‐13C‐glaucine 1.5 H3PO4 was obtained by conversion of the hydrobromide to the free base and treatment with 85% phosphoric acid in ethanol.
Synthesis of non‐bridging 18O3 labeled phosphate monoesters
Authors: Calvo Kim C.
Published: October 2006

A new method is reported for the synthesis of tri‐18O substituted phosphate monoesters where the phosphoryl oxygen ester bond is 16O. The method relies on the reactivity of trivalent phosphorus toward hydrolysis and oxidation to produce dimethyl [18O3]‐phosphorochloridate with a minimal excess of labeled water. This chlorophosphate diester can be used to prepare a wide variety of phosphate monoesters where the three peripherial oxygens are labeled.
Synthesis of carbon‐13 and carbon‐14 labelled triazolo‐1,4‐benzodiazepines
Authors: Banks William R. , Hawi Amale A. , Digenis George A.
Published: October 2006

An efficient two‐step synthesis of 8‐chloro‐1‐methyl‐6‐phenyl‐[3H]‐S‐triazolo‐[4,3‐a][1,4]‐benzodiazepine (alprazolam) and 8‐chloro‐6‐(2‐chlorophenyl)‐1‐methyl‐[3H]‐S‐triazolo‐[4,3‐a][1,4]‐benzodiazepine (triazolam) labelled with carbon‐13 or carbon‐14 from their corresponding hydrazines is reported. The method involves acylation of the appropriate hydrazine using the mixed carbonic anhydride of sodium [13C] or [14C] acetate and isobutylchloroformate under mild conditions. Thermolysis of the resulting acetylhydrazides gave the target carbon‐14 and carbon‐13 labelled compounds in good yields.
Synthesis of deuterium‐labellec alkenes
Authors: Sirokán G. , Molnár Á. , Bartók M.
Published: October 2006

Novel or improved synthesis of six deuterated 1‐alkenes (1‐hexene‐[3,3‐2H2], 5‐methyl‐1‐hexene‐[3,3‐2H2], 1‐pentene‐[1,1,2‐2H3], 1‐hexene‐ [2‐2H], 1‐hexene‐[1,1,3,3‐2H4] and 1‐hexene‐[1,1,2,3,3‐2H5]) are reported. The isotopic purities of these labelled alkenes were 99, 99, 92, 99, 76 and 86%, respectively.
Syntheses of [6‐14C] and [5‐carboxy, 6‐14C2]nitrendipine
Authors: Maul W. , Scherling D.
Published: October 2006

[6‐14C]Nitrendipine synthesis started from barium[14]carbonate, which was converted to [1‐14C]acetyl chloride. The acid chloride was condensed with Meldrum's acid (2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione). The resulting intermediate was treated with boiling methanol to give methyl [3‐14C]acetoacetate. The reaction with gaseous ammonia in toluene yielded the corresponding methyl 3‐amino[3‐14C]crotonate which was condensed with ethyl 2‐(3‐nitro‐benzylidene) acetoacetate to obtain [6–14C]nitrendipine.

[5‐carboxy, 6‐14C2]Nitrendipine was synthesized by an analogous procedure starting from methyl [1,3‐14C2]acetoacetate.
Purification of 3H‐dihydroalprenolol by two dimensional thin layer chromatography
Authors: Smisterová Jarmila , Soltés Ladislav , Kállay Zoltan
Published: October 2006

A two dimensional thin‐layer chromatographic method developed for the purification and analysis of (‐)‐[3H]dihydroalprenolol, by using an acidic mobile phase (butanol/water/acetic acid 25:10:4, v/v) in one direction and a basic eluent (chloroform/acetone/tri‐ethylamine 50:40:10, v/v) in another direction.
A synthon for C‐20 trideuterated eicosanoids: Preparation of [2H3]‐arachidonic acid
Authors: Prakash Chandra , Saleh Samir , Sweetman Brian J. , Taber Douglass F. , Blair Ian A.
Published: October 2006

Starting from hex‐5‐yn‐1‐ol an efficient seven step synthesis of (Z)9‐[2H3](non‐3‐en‐1‐yl) triphenylphosphonium bromide is described. This Wittig reagent is a key intermediate for the synthesis of C‐20 trideuterated eicosanoids. Introduction of deuterium at C‐20 provides standards that are stable to a wide range of reagents and reaction conditions. The utility of the Wittig synthon was demonstrated by the preparation of C‐20 trideuterated arachidonic acid.
Synthesis of γ‐amino[4‐11C]butyric acid (GABA)
Authors: Antoni Gunnar , Långström Bengt
Published: October 2006

A one‐pot synthesis of no‐carrier added γ‐amino[4‐11C]butyric acid (GABA) starting with hydrogen [11C]cyanide prepared from [11C]carbon dioxide, is presented. Hydrogen [11C]cyanide was trapped in tetrahydrofuran/potassium hydroxide in the presence of the amino polyether Kryptofix 2.2.2. A Michael addition with ethyl acrylate followed by a selective reduction and hydrolysis of the resulting amino ester gave [4‐11C]GABA. The radiochemical purity of GABA was higher than 99% and the decay corrected radiochemical yield was 60–65% based on the amount of H[11C]CN used. The total synthesis time including purification was around 40 min, counted from the start of the Michael addition reaction.
Synthesis of carbon‐13 labeled ibuprofen
Authors: Hsi R. S. P. , Stelzer L. S. , Stolle W. T.
Published: October 2006

This report describes the synthesis of ibuprofen of labeled with carbon‐13 either at the terminal methyl carbons, or at the methine carbon of the isobutyl side chain. The synthetic route involves the removal of the isopropyl group in the isobut I side‐chain of ibuprofen via 2‐[4‐(2‐methyl‐1‐propenyl)phenyl] propionic acid followed by restoration of the isopropyl group with a Wittig reaction, using appropriate carbon‐1 3 labeled acetone as the precursor of the isopropyl group. Interesting NMR coupling data attributable to phosphorous and carbon‐13 are presented in the experimental section.
Stereospecific synthesis of specifically deuterated metoprolol enantiomers from chiral starting materials
Authors: Umesha Shetty H. , Murthy Satya S. , Nelson Wendel L.
Published: October 2006

Enantiomers of metoprolol (1) containing six deuterium atoms in the isopropyl methyl groups [(2R‐2], two deuterium atoms at C‐2 and C‐6 of the aromatic ring [(2S)‐3], and two deuterium atoms at C‐3 of the propanolamine side chain [(2S)‐4] were prepared. Chiral 2,2‐dimethyl‐1,3‐dioxolane‐4‐methanols [(4R)‐5 and (4S)‐5] were key synthons. Sources of deuterium were [2H6]‐isopropylamine, 4‐(2‐methoxyethyl)‐2,6‐[2H2]‐phenol (12), prepared by 2HCl/2H2O exchange, and (4S)‐2,2‐dimethyl‐1,3‐dioxolane‐4‐[2H2]‐4‐methanol (19), prepared by LiAl2H4 reduction of (4S)‐methyl 2,2‐dimethyl‐1,3‐dioxolane‐4‐carboxylate. Enantiomeric excess was greater than 94% for each of the prepared enantiomers, as determined independently by 1H NMR spectroscopy on diastereomeric derivatives and by chiral column HPLC.
A short synthesis of 5‐amino[4‐14]laevulinic acid hydrochloride
Authors: Cambell J B , Johnston J S
Published: October 2006

5‐Amino[4‐14C]laevulinic acid hydrochloride has been prepared from potassium [14C]cyanide in 56% overall yield. The key step is the palladium[0] catalyzed coupling of 2‐phthalimido[1‐14C]acetyl chloride with 2‐carboethoxyethylzinc iodide to give 5‐phthalimido[4‐14C]laevulinic acid ethyl ester in 86% yield. The synthesis was carried out at high specific activity from 720mCi of starting material.
Synthesis of high specific active tritiated Leu‐enkephalin in the leucine residue
Authors: Baba S. , Hasegawa H. , Shinohara Y.
Published: October 2006

Leu‐enkephalin labelled with tritium in the Leu residue has been prepared. Synthesis of the precursor peptide, [4,5‐dehydro Leu5‐]Leu‐enkephalin, was carried out by solid phase synthesis using Fmoc amino acid derivatives. The peptide was tritiated catalytically yielding 3H‐Leu‐enkephalin with a specific radioactivity of 4.39 TBq/mmol. The distribution of tritium label was investigated by reversed‐phase high performance liquid chromatography with a synchronized accumulating radioisotope detector following acidic and enzymatic hydrolysis, which confirmed that the tritium label was entirely located at Leu residue.
Synthesis and characterization of isotopically‐labelled cysteine‐ and glutathione conjugates of methylisocyanate
Authors: Han Deog‐Hwa , Pearson Paul G. , Baillie Thomas A.
Published: October 2006

Four isotopically labelled analogs of S‐(N‐methylcarbamoyl)glutathione (SMG), the glutathione conjugate of methylisocyanate, and three isotopically‐labelled derivatives of S‐(N‐methylcarbamoyl)cysteine (SMC), the corresponding cysteine adduct, have been prepared by reaction of glutathione and cysteine, respectively, with [1‐13C]‐, [3‐13C]‐, [3‐14C]‐ or [3,3,3‐2H3]methylisocyanate. The latter species, which served as key intermediates in the syntheses, were obtained either by reaction of [1‐13C]acetylchloride with sodium azide (to give [1‐13C]methylisocyanate), or by reaction of silver cyanate with iodomethane labelled with 13C, 14C or deuterium (to give the methyl‐substituted compounds). Condensation of labelled methylisocyanate with glutathione or cysteine proceeded smoothly and in high yield in aqueous acetonitrile solution, and afforded the target conjugates in high isotopic purity. The structures of the products were confirmed by fast atom bombardment tandem mass spectrometry (FAB/MS/MS) and by 1H‐ and 13C‐NMR spectroscopy.
Synthesis of (22R,23R)‐ and (22S,23S)‐[4‐14C]‐24‐EPIBRASSINOLIDE
Authors: Seo S. , Nagasaki T. , Katsuyama Y. , Matsubara F. , Sakata T. , Yoshioka M. , Makisumi Y.
Published: October 2006

The title compounds were synthesized for metabolic studies in plants and animals, with 14C labelling being made at position 4 of the epibrassinolides 4 and 5 in an overall radiochemical yield of 3.22% and 4.46%, respectively, based on barium [14C]carbonate.
A general method for tritium labelling of benzimidazole carbamates by catalytic exchange in dioxane solutions
Authors: Lacey Ernest , Dawson Michael , Long Mervyn A. , Than Chit
Published: October 2006

Benzimidazole carbamates (BZCs) act as inhibitors of the tubulin‐microtubule equilibria in eukaryotic organisms. Recently drug resistance to this class of compounds in helminth parasites has been shown to be due to a reduced ability of resistant tubulin to bind BZCs. In order to quantitate the nature of the tubulin‐BZC interaction a general method for the specific tritium labelling of BZCs has been developed. The BZCs: mebendazole, oxfendazole, parbendazole, oxibendazole, albendazole and fenbendazole were labelled by catalytic exchange using palladium on calcium carbonate in pure dioxane at 60°C under tritium gas. The position of label incorporation for tritiated albendazole was determined by tritium‐NMR as the 4‐position of benzimidazole nucleus. The yields for individual BZCs varied from 8 to 68% for a range of specific activity of 0.44 to 13.4 Ci/mmole.
An iterative synthesis of radiolabelled polyethylene glycol oligomers
Authors: Dellaria Joseph F. , Denissen Jon F. , Kerdesky Francis A. J. , Maki Robert G. , Hoffman Daniel J. , Nellans Hugh N.
Published: October 2006

A synthetic method has been developed for the iterative preparation of unlabelled and 3H‐polyethylene glycol (PEG) oligomers. The strategy involved alkylating the sodium anion of mono‐tritylated ethylene glycol oligomers (Ph3C[OCH2CH2]nOH, n=1−28) with O‐tosyl‐O‐allyl‐triethylene glycol or O‐tosyl‐O‐allyl‐pentaethylene glycol. Subsequent ozonolysis of the terminal olefin followed by reduction with NaBH4 or NaB[3H]4 provided the next higher mono‐tritylated ethylene glycol oligomer which could be deprotected to the final glycol oligomer (H[OCH2CH2]nOH, n=4−34) or carried on in the iterative process. The method provides discrete PEG oligomers of high specific activity (20.6–48.6 mCi/mmoL) in 96–98% radiochemical purity.
[4‐3H]‐labelling of the calcium ionophore A 23187 (calcimycin)
Authors: Prudhomme M. , Jeminet G. , Schott D. , Morgat J. L. , Beaulieu P.
Published: October 2006

[4‐3H‐labelled]‐A 23187 (or calcimycin) has been obtained as a magnesium salt from the corresponding 4‐bromo derivative using tritiated hydrogen gas in the presence of 10% Pd/C catalyst. The specific radioactivity proved to be 50.6 Ci/mmole (1872.2 GBq/m mole).
Synthesis of [8,9,10,11‐13C4]leukotriene C4
Authors: Raftery Mark J. , Gaskell Simon J.
Published: October 2006

A “one pot” reduction of ethyl [1,2‐13C2]bromoacetate with diisobutylaluminium hydride in dichloromethane, followed by reaction with triphenylphosphine, then triethylamine, yields [1,2‐13C2]formylmethylenetriphenylphosphorane. Consecutive Wittig reactions of [1,2‐13C2] formylmethylenetriphenylphosphorane with methyl 5(S),6(R)‐epoxy‐6‐formylhexanoate and subsequent Wittig reaction with Z‐3‐nonen‐ 1‐triphenylphosphorane yields [8,9,10,11‐13C4]LTA4methyl ester, which is readily converted to [8,9,10,11‐13C4]LTC4.
Synthesis of radiolabelled clenbuterol analogues
Authors: Pegg Graham G. , Sillence Martin N. , Sleeman Madonna J. , Lindsay Derek B.
Published: October 2006

Oxidation of clenbuterol 1a with pyridinium chlorochromate yielded 4‐amino‐3,5‐dichloro‐α‐tert‐butylaminoacetophenone 5. Tritiated clenbuterol 1b was produced by reduction of 5 with sodium [3H]borohydride. Radioiodination of the clenbuterol precursor [2‐tert‐butylamino‐1‐(4‐aminophenyl)‐ethanol] 2 yielded [2‐tert.‐butylamino‐1‐(4‐amino‐3‐[125I] iodophenyl)‐ethanol] 3b.
Fixing the system: Breaking the glass ceiling in health care
Authors: Eiser Barbara J. A. , Morahan Page
Published: October 2006

Even though health care organizations clearly need to make full use of all their potential leaders, including women, females continue to be underrepresented in most levels of leadership. What are the major barriers to women's advancement in the health care field, and what strategies can health care organizations use to overcome these barriers?
Measuring Cell Adhesion on RGD‐Modified, Self‐Assembled PEG Monolayers Using the Quartz Crystal Microbalance Technique
Authors: Knerr Robert , Weiser Barbara , Drotleff Sigrid , Steinem Claudia , Göpferich Achim
Published: October 2006

Summary: In this study, the suitability of a flow‐through quartz crystal microbalance system for the detection of the adhesion of rMSCs and 3T3‐L1 fibroblasts on different surfaces is demonstrated. Frequency shifts for rMSCs of −6.7 mHz · cell−1 and −2.0 mHz · cell−1 for 3T3‐L1 cells could be detected on non‐modified gold sensors, revealing that the frequency shift per cell is comparable to that of a static setup. Modifying the sensor surface with SAMs of thioalkylated ω‐amine‐terminated PEG derivatives led to cell‐adhesion‐resistant surfaces. Total frequency shifts of only −20 ± 7 Hz showed that protein adsorption was also significantly reduced. Attaching 35 pmol · mm−2 of the GRGDS cell adhesion motif to the SAMs induced specific cell adhesion due to RGD‐integrin interactions; the resonance frequency dropped by 3.4 mHz · cell−1. Furthermore, the kinetics of cell detachment could be determined. The corresponding processes were completed after 10 min for trypsin, and not before 90 min with GRGDS. Moreover, the detectability of cell adhesion was shown to increase after the addition of manganese cations. The total decrease in the resonance frequency was almost 80 Hz in the presence of Mn2+ (6.4 mHz · cell−1).

Staining the cytoskeleton of the rMSCs shows that the GRGDS‐modified surfaces are almost completely covered with well‐spread cells.

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Staining the cytoskeleton of the rMSCs shows that the GRGDS‐modified surfaces are almost completely covered with well‐spread cells.
Rapid and Efficient Enzyme Encapsulation in a Dendrimer Silica Nanocomposite
Authors: Miller Scott A. , Hong Edmund D. , Wright David
Published: October 2006

Summary: We report the entrapment of horseradish peroxidase and quantitative encapsulation of glucose oxidase within silica nanoparticles by utilizing an amine‐terminated dendritic template. Our improved strategy employs a water‐soluble biomimetic template which is able to catalyze the condensation of Si(OH)4 to silica nanoparticles while trapping an enzyme inside the mesoporous material. Kinetic analysis shows enzyme functionality to be mostly unchanged. Also, the role of pI and ionic strength within the encapsulation environment was found to strongly influence encapsulation. These results suggest that the electrostatic manipulation of a strong supramolecular silica‐precipitating complex of enzyme and dendrimer has the potential of adding a vast array of chemical and biological activity to hybrid materials.

Enzyme immobilization within a silica nanocomposite.

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Enzyme immobilization within a silica nanocomposite.
Enzymatic Degradation of Biodegradable Polyester Composites of Poly(L‐lactic acid) and Poly(ε‐caprolactone)
Authors: Tsuji Hideto , Kidokoro Yuki , Mochizuki Masatusgu
Published: October 2006

Summary: Two different types of biodegradable polyester composites, PLLA fiber‐reinforced PCL and PCL/PLLA blend films were prepared at PCL/PLLA ratio of 88/12 (w/w), together with pure PCL and PLLA films. Their enzymatic degradation was investigated by the use of Rhizopus arrhizus lipase and proteinase K as degradation enzymes for PCL and PLLA chains, respectively. In the FRP film, the presence of PLLA fibers accelerated the lipase‐catalyzed enzymatic degradation of PCL matrix compared with that in the pure PCL film, whereas in the blend film, the presence of PLLA chains dissolved in the continuous PCL‐rich domain retarded the lipase‐catalyzed enzymatic degradation of PCL chains. In contrast, in the FRP film, the proteinase K‐catalyzed enzymatic degradation of PLLA fibers was disturbed compared with that of the pure PLLA film, whereas in the blend film, the proteinase K‐catalyzed enzymatic degradation rate of particulate PLLA‐rich domains was higher than that of pure PLLA film. The reasons for aforementioned enhanced and disturbed enzymatic degradation are discussed.

Normalized PCL weight loss of pure PCL, FRP, and blend films as a function of Rhizopus arrhizus lipase‐catalyzed enzymatic degradation time.

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Normalized PCL weight loss of pure PCL, FRP, and blend films as a function of Rhizopus arrhizus lipase‐catalyzed enzymatic degradation time.
GovStat statistical interactive glossary: Two studies of effectiveness and control
Authors: Brown Ron T. , Haas Stephanie W. , Haas Stephanie W. , Cao Leo
Published: October 2006

The GovStat Statistical Interactive Glossary (SIG) is designed to allow users of government statistical websites to consult definitions of statistical terms while continuing their current task of browsing statistical websites. In this paper, we present results from two studies of the SIG that evaluated the effectiveness of the SIG presentations. We specifically focus on two areas: the effects of three presentation formats (text only, graphics + text, animation + text) on user performance and preferences, and the effects of three levels of controls for animations on user performance and preferences. Our findings have implications for designers of just‐in‐time help, as well as raising questions for future research.
Selection practices for Web‐based government publications in state depository library programs: Comparing active and passive approaches
Authors: Lin Chi‐Shiou , Eschenfelder Kristin R.
Published: October 2006

This comparative case study examined the capture and selection practices used to populate electronic depositories of born‐digital state government publications. The three case sites illustrate differences in collection building approaches, technological infrastructures, and statutory contexts. The findings reveal two basic modes of selection practices—active selection and passive selection, and three selection models based on the loci of selection control—library selection, liaison selection, and creator selection. Also, the findings suggest the power of defining and selecting government publications for state depositories is shifting from government agencies to state libraries in the active selection. The authors argue for the needs to attend to Web publications in non‐traditional formats (e.g. an interactive HTML document) and to include common publications produced for lay citizens (e.g. brochures, fact sheets, FAQs, etc.) in the permanent collections in order to fully document the government activities for the historical record of a society.
Establishing a research agenda for studies of online search behaviors
Authors: Barry Carol , Janes Joseph , Goodrum Abby , Hirsh Sandra
Published: October 2006

As follow‐up to discussions at the 2002 ASIST SIG USE Research Symposium on “Measuring Search Behaviors,” a Delphi study was conducted. It was designed to solicit expert opinion on two methodological aspects of research on online search behaviors: (1) the variables that are most critical to such studies and (2) methods for measuring these variables. A panel of over 75 experts participate in the three rounds of the study. A small number of variables related to the search process, databases and search systems, and the user/searcher were identified as having the highest priority for research, and can form the basis for a research agenda in the study of online searching behaviors. The third round of the survey identified the strengths and weaknesses of possible approaches to measurement of 11 of the variables that pose significant measurement challenges. In this panel, the outcomes of the study will be briefly reported. Then the panelists will discuss these results from the perspectives of a scholar who did not participate in the study (Janes), a scholar who did participate (Goodrum), and a practitioner who did participate (Hirsh).
Searching the intranet: Corporate users and their queries
Authors: Stenmark Dick
Published: October 2006

By examining the log files from a corporate intranet search engine, we have analysed the actual web searching behaviour of real users in a real business environment. While building on previous research on public search engines, we apply an alternative session definition that we argue is more appropriate. Our results regarding session length, query construction and result page viewing confirm some of the findings from similar studies carried out on public search engines but further our understanding of web searching by presenting details on corporate users' activities. In particular, we suggest that search sessions are shorter than previously suggested, search queries have fewer terms than observed for public search engines, and number of examined result pages is smaller than reported in other research. More research on how corporate intranet users search for information is needed.
Q‐measures for binary divided networks: An investigation within the field of informetrics
Authors: Rousseau Ronald
Published: October 2006

Q‐measures for binary divided networks, as introduced by Flom, Friedman, Strauss and Neaigus are studied. These measures try to capture the idea of bridges between two groups in a connected undirected network. Values for these measures are calculated for building blocks such as line and star networks. As an application two small co‐author networks are analyzed.
Ontological research and its applications to the biomedical domain
Authors: Ruiz Miguel E. , Bodenreider Olivier , Little Eric , Srinivasan Padmini
Published: October 2006

Ontology is an area of philosophy “the science of what is, of the kinds and structures of objects, properties, events and relations in every area of reality” (Smith & Welty, 2001). In computer and information science ontology is used to represent the common understanding and concepts related to a specific domain. In this sense, an ontology includes a set of generic concepts as well as their definitions and relationships. The main purpose of using an ontology is to present the shared view of the knowledge of a domain. Other advantages of ontologies are that they provide computer systems with a way to specify concepts, allow interoperability and reusability, and ultimately represent a way to relate the concepts expressed in our computer information systems with the real objects that they represent. This panel will present a general overview of the current issues on ontological research its applications in biomedicine. The panel includes presentations on the state‐of‐the‐art in ontology research as well as several applications in the biomedical domain.
Measuring mental models: Rationales and instruments
Authors: Zhang Yan , Wang Peiling
Published: October 2006

The purpose of this study is to develop and test an instrument for measuring users' mental models of Web search engines. Mental models play an important role in users' interactions with a system. Understanding users' mental models is important to the design of congruent interfaces.
An annotation paradigm: The social hyperlink
Authors: Ciszek Thomas , Fu Xin
Published: October 2006

We seek to understand how hyperlinks act as agents of annotation and play a fundamental role in how we seek and interpret information on the Internet. Recognizing that the hyperlink is a form of latent human annotation, we emphasize the significance of hyperlinking to establish authority. Furthermore, we assess the evolution of hyperlink taxonomies, acknowledging that as annotations, hyperlinks have developed into socio‐cognitive entities. In the second generation of the Internet (particularly the Blogosphere), we seek to confirm the existence of social motivations for hyperlinking; thus substantiating the idea of a social hyperlink as a phenomenon prerequisite to the development of a social‐linking theory.
Cross validation of neural network applications for automatic new topic identification
Authors: Özmutlu H. Cenk , Çavdur Fatih , Spink Amanda , Özmutlu Seda
Published: October 2006

There are recent studies in the literature on automatic topic‐shift identification in Web search engine user sessions; however most of this work applied their topic‐shift identification algorithms on data logs from a single search engine. The purpose of this study is to provide the cross‐validation of an artificial neural network application to automatically identify topic changes in a web search engine user session by using data logs of different search engines for training and testing the neural network. Sample data logs from the Norwegian search engine FAST (currently owned by Overture) and Excite are used in this study. Findings of this study suggest that it could be possible to identify topic shifts and continuations successfully on a particular search engine user session using neural networks that are trained on a different search engine data log.
The making of the ASIST Digital Library
Authors: Hlava Marjorie , Grant Annette , Redmond‐Neal Alice , Finley Colleen
Published: October 2006

The American Society for Information Science and Technology publications in a full text searchable digital library. All documents, Journal, Proceedings, Bulletin, Annual Review and Thesaurus needed to be captured to the same XML Standard from a wide variety of original formats, paper and digital. All articles were indexed using a semi automated process against the thesaurus. The DTD is a holdover from SGML implementations. The paper will outline the process for the digitization, the software used, the production process and the verification programs to insure a seamless load of the data to the Digital Library Site on the Wiley InterScience Platform. There were two streams of data used. We only used Access tagged data for the Bulletin Wiley used our version of the tagged data for all other products. Participants will learn:

how to adapt an SGML DTD to XML

how to apply keywords from a taxonomy for enhanced retrieval

an outline of a real production process for XML document conversion
Repeat visits to Vivisimo.com: Implications for successive Web searching
Authors: Jansen Bernard J. , Koshman Sherry , Spink Amanda
Published: October 2006

We investigate the occurrence of Web searchers returning the same information course, in this case the Vivisimo Web search engine. We analyze data from a transaction log spanning a roughly 8‐day period with approximately 1,200,000 records. During this time 40,227 users made repeated daily visits to the search engine, submitting 648,897 queries. Our findings show that repeat users make up about 21% of the user base. These repeat users account for over 45% of all sessions and nearly 60% of all queries submitted. Most repeat users (46%) visited the search engine on two days during the data collection period, but a sizeable percentage (17%) made 5 or more daily visits to Vivisimo. We discuss the implications for successive searching and future research.
In search of learning and knowing
Authors: Wells Amy Tracy
Published: October 2006

The supportive arguments for hypermedia and hypertext learning environments typically assert that as the systems permit individuals to self‐select content based on needs, to control the pace and content, and/or provide a measure of control otherwise missing in traditional, linear texts and lectures, learning and knowing outcomes increase. There are two difficulties with this argument and some of the resultant empirical literature. The first is that knowing is a complex phenomenon which can be variously defined and measured. However, the literature often focuses on a narrow range of definitions and measures and doesn't exploit the full range of theory. This, in turn, may lead to the second difficulty, that of very limited outcomes. A cognitive model of learning and knowing is presented and contrasted with a sample of empirical research. This model provides a solid theoretical basis for research into cognitively engaging hypermedia systems.
Concerning the preparation and use of substances with a magnetic susceptibility equal to the magnetic susceptibility of air
Authors: Bakker Chris J.G. , de Roos Remmert
Published: October 2006

In this work it is demonstrated that the susceptibility of diamagnetic substances, such as water and agarose gel, can easily be tuned to the susceptibility of air by the addition of a proper amount of strongly paramagnetic ions, in this case 16.6 ± 0.1 mM holmium(III). The resultant air‐equivalent substances are shown to allow the creation of objects that do not disturb the static magnetic field of the scanner and hence do not invoke susceptibility artifacts, regardless of the objects' shape, size, and orientation with respect to B0, and regardless of the pulse sequence being used. The addition of the proper amount of holmium(III) to aqueous solutions and gels is further shown to exert a negligible influence on the chemical shift and to cause a moderate increase of the relaxation rates 1/T1 and 1/T2. The results indicate the potential of air‐equivalent substances for many purposes, including construction of artifact‐free test objects; experimental setups and accessory devices; investigation of systems that contain air cavities, gas bubbles, etc.; and monitoring of system‐related and object‐induced field disturbances. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Bullatencin, 4‐deoxyasimicin, and the uvariamicins: Additional bioactive annonaceous acetogenins from Annona bullata rich. (Annonaceae)
Authors: Hui Yu‐Hua , Wood Karl V. , McLaughlin Jerry L.
Published: October 2006

Additional bioactive Annonaceous acetogenins have been isolated from the EtOH extract of the bark of Annona bullata Rich. by bioactivity‐directed fractionation using lethality to brine shrimp. These acetogenins include bullatencin, a new single tetrahydrofuran acetogenin having a double bond in the hydrocarbon chain; 4‐deoxyasimicin, a new adjacent bis‐tetrahydrofuran acetogenin; and the uvariamicins, an isomeric mixture of four single tetrahydrofuran acetogenins. These acetogenins showed selective cytotoxicities for certain human solid tumor cell lines comparable to or better than adriamycin. © 1992 Wiley‐Liss, Inc.
Kinetics of Alexandrium minutum halim toxin accumulation in mussels and clams
Authors: Lassus P. , Ledoux M. , Bardouil M. , Bohec M. , Erard E.
Published: October 2006

Mussels (Mytilus edulis) and clams (Ruditapes philippinarum) were contaminated experimentally using cultures of Alexandrium minutum, a toxic dinoflagellate isolated from French coastal waters. Experiments were carried out in continually flushed and open‐circuit systems using Alexandrium densities of 100 to 700 cells/ml delivered to tanks containins the shellfish. All experiments indicated an inversion of the relative proportions of sonyautoxins (GTX2 and GTX3) in shellfish meat during decontamination, whereas saxitoxin (SIX) only accumulated during mussel depuration. However, in mussels a density as low as 100 cells/ml led within 10 days to bioaccumulation of paralytic shellfish poisoning (PSP) toxins above the public health threshold. Similar results were observed in clams subjected to fivefold higher cell densities, indicating a less effective assimilation of the dinoflagellate than by mussel. Decontamination experiments on PSP toxin‐contaminated mussels (360 μs STX eq./100 g or lower uptake) fed two nontoxic diets (1,000 and 10,000 cells/ml of Tetraselmis suesica) showed an appreciable reduction in the time needed to decrease toxin concentration below the accepted threshold for human consumption. We suggest that a simple relation can be established between initial toxicity, the concentration of nontoxic alga available, and the time required for depuration once decontamination kinetics becomes linear and corresponds to the inverse of contamination kinetics. © 1994 wiley‐Liss, Inc.
A specific and sensitive method for the determination of linamarin in urine
Authors: Carisson Lena , Mlingi Nicholas , Ronquist Gunnar , Rosling Hans
Published: October 2006

A method is described for the quantitative determination of the cyanogenic glycoside linamarin. A preseparation procedure for urine samples was necessary to remove interfering substances. This was done by solid‐phase extraction on a silica column containing cyclohexyl functional groups, which retained linamarin but allowed thiocyanate to pass unrestricted through the column. After elution of linamarin from the column by 35% (v/v) aqueous methanol, the glycoside was quantified following enzymatic hydrolysis, using the specific enzyme linamarase, and the free cyanide thus liberated was estimated spectrophotometrically. This method allowed quantification of linamarin in urine down to 10 μmol/l, with an estimated recovery of 91%. In 75 Tanzanian subjects consuming insufficiently processed cassava, the mean (± SD) urinary linamarin concentration was 104 (± 104) μmol/l (range 0‐644 n,mol/L), while that for thiocyanate was 486 (μ 451) μmol/l (range 10‐2,940 μmol/l), giving an approximate 15 molar concentration ratio between urinary linamarin and thiocyanate. © 1995 Wiley‐Liss, inc.
Hautdurchdringung ätherischer Öle. Pharmakokinetische Untersuchungen
Authors: Weyers Wolfgang , Brodbeck Rudolf
Published: October 2006

Volatile oils are frequently employed in the local treatment of pain. 1,8‐Cineole, the principal component of eucalyptus oil, was used as a model substance to determine whether this active component can be detected in effective amounts at the target area in the skeletal muscles after at the target area in the skeletal muscles after dermal application. The investigation showed surprisingly large differences depending on the manner of application. The relative bioavailability of the model substance 1,8‐cineole obtained by using an applicator was 320% as compared with that obtained by using an occlusive dressing. This has practical effects on the dosage and on the frequency of application.
Benzomorphananaloge Tricyclen: Synthese und Pharmakologische Eigenschaften
Authors: Wünsch Bernhard
Published: October 2006

Prof. Dr. B. Wünsch wurde 1995 von der Deutschen Pharmazeutischen Gesellschaft auf seiner Jahrestagung in Jena mit dem Johann‐Wolfgang‐Döbereiner‐Preis ausgezeichnet. Diesen Preis vergibt die DPhG zur Förderung des wissenschaftlichen Nachwuchses speziell zur Anerkennung überdurchschnittlicher Habilitationen. Er ist verbunden mit einer materiellen Anerkennung von 10.000 DM, die zur Förderung der weiteren wissenschaftlichen Arbeit bestimmt ist. Mit der Annahme des Preises verpflichtet sich der Preisträger, seine Forschungsergebnisse in einer allgemein verständlichen Form der Wissenschaftlichen Öffentlichkeit vorzustellen.
Diacid architecture effect on the synthesis and microstructure of rigid‐rod poly(benzobisthiazole)s
Authors: Chen Chien‐Fan , Juang Lih‐Jeng , Hsu Tzu‐Chien , Wang Jeh‐Jeng , Wang Li‐Fang
Published: October 2006

Six poly(benzobisthiazole)s (PBTs) have been synthesized by the solution polycondensation of 2,5‐diamino‐1,4‐benzenedithiol in poly(phosphoric acid) (PPA) with systematically varied diacids to demonstrate the diacid architecture effect of the aromatic heterocyclic rigid‐rod polymers. The role of PPA is identified and the effects of phosphorus pentoxide and water on PBT during polycondensation are discussed. Polymer properties such as the inherent viscosity and decomposition temperature are correlated to the diacid chemistry. The effect of diacid architecture on the synthesis and microstructure of PBT is studied. The results are discussed in terms of resonance, symmetry, and solubilization of the diacids. Copyright © 2006 Society of Chemical Industry
Biodegradable polymers applied in tissue engineering research: a review
Authors: Martina Monique , Hutmacher Dietmar W
Published: October 2006

Typical applications and research areas of polymeric biomaterials include tissue replacement, tissue augmentation, tissue support, and drug delivery. In many cases the body needs only the temporary presence of a device/biomaterial, in which instance biodegradable and certain partially biodegradable polymeric materials are better alternatives than biostable ones. Recent treatment concepts based on scaffold‐based tissue engineering principles differ from standard tissue replacement and drug therapies as the engineered tissue aims not only to repair but also regenerate the target tissue. Cells have been cultured outside the body for many years; however, it has only recently become possible for scientists and engineers to grow complex three‐dimensional tissue grafts to meet clinical needs. New generations of scaffolds based on synthetic and natural polymers are being developed and evaluated at a rapid pace, aimed at mimicking the structural characteristics of natural extracellular matrix. This review focuses on scaffolds made of more recently developed synthetic polymers for tissue engineering applications. Currently, the design and fabrication of biodegradable synthetic scaffolds is driven by four material categories: (i) common clinically established polymers, including polyglycolide, polylactides, polycaprolactone; (ii) novel di‐ and tri‐block polymers; (iii) newly synthesized or studied polymeric biomaterials, such as polyorthoester, polyanhydrides, polyhydroxyalkanoate, polypyrroles, poly(ether ester amide)s, elastic shape‐memory polymers; and (iv) biomimetic materials, supramolecular polymers formed by self‐assembly, and matrices presenting distinctive or a variety of biochemical cues. This paper aims to review the latest developments from a scaffold material perspective, mainly pertaining to categories (ii) and (iii) listed above. Copyright © 2006 Society of Chemical Industry
Surface characterization and barrier properties of plasma‐modified polyethersulfone/layered silicate nanocomposites
Authors: Wu Tzong‐Ming , Yang Shih‐Hsien
Published: October 2006

This study describes the preparation of polyethersulfone (PES)/layered silicate nanocomposites (PLSNs) by mixing PES polymer chain into organically‐modified layered silicate in 1‐methyl‐2‐pyrrolidinone (NMP) solution. Both X‐ray diffraction data and transmission electron microscopy images of PLSNs indicate that the silicate layers were almost exfoliated and randomly distributed into the PES matrix. The mechanical and barrier properties of PLSNs show remarkable enhancement in the storage modulus and water/oxygen permeability when compared with that of neat PES matrix. Surfaces modification of PES and PLSN films with various treated times, system pressures, and radio frequency (RF) powers were performed using a mixture of oxygen (O2) and nitrogen (N2) plasmas. The topographical and physical properties of plasma‐modified PES and PLSN surfaces were investigated using scanning probe microscopy (SPM), contact‐angle measurements, and X‐ray photoelectron spectroscopy (XPS). These results indicate that the surface roughness of PLSNs with the same condition of plasma modification is lower than that of neat PES matrix and is probably due to the increase of stiffness with the presence of inorganic layered silicates in PES matrix. The surface properties of the PES and PLSNs are also changed from hydrophobic to hydrophilic. The XPS spectra suggest that the exposure of the PES and PLSNs to the plasmas led to the combination of etching reactions of polymer surface initiated by plasma and the following addition reactions of new oxygen‐ and nitrogen‐containing functional groups onto polymer surfaces to change their surface properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3185–3194, 2006
Evaluation of piezoelectric PVDF polymers for use in space environments. III. Comparison of the effects of vacuum UV and gamma radiation
Authors: Dargaville Tim R. , Elliott Julie M. , Celina Mathew
Published: October 2006

Films of piezoelectric PVDF and P(VDF‐TrFE) were exposed to vacuum UV (115–300 nm VUV) and γ‐radiation to investigate how these two forms of radiation affect the chemical, morphological, and piezoelectric properties of the polymers. The extent of crosslinking was almost identical in both polymers after γ‐irradiation, but surprisingly, was significantly higher for the TrFE copolymer after VUV‐irradiation. Changes in the melting behavior were also more significant in the TrFE copolymer after VUV‐irradiation due to both surface and bulk crosslinking, compared with only surface crosslinking for the PVDF films. The piezoelectric properties (measured using d33 piezoelectric coefficients and D‐E hysteresis loops) were unchanged in the PVDF homopolymer, while the TrFE copolymer exhibited more narrow D‐E loops after exposure to either γ‐ or VUV‐radiation. The more severe damage to the TrFE copolymer in comparison with the PVDF homopolymer after VUV‐irradiation is explained by different energy deposition characteristics. The short wavelength, highly energetic photons are undoubtedly absorbed in the surface layers of both polymers, and we propose that while the longer wavelength components of the VUV‐radiation are absorbed by the bulk of the TrFE copolymer causing crosslinking, they are transmitted harmlessly in the PVDF homopolymer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3253–3264, 2006
The study of local dual‐peak vibratory properties in ferroelectric P(VDF‐TrFE) films
Authors: Zhu Guodong , Zeng Zhigang , Zhang Li , Yan Xuejian , Li Jie
Published: October 2006

In this article, we reported the studies on the local dual‐peak vibrations in ferroelectric P(VDF‐TrFE) films, induced by an alternating voltage with its amplitude high enough to cause polarization reversal. A further study showed that this dual‐peak vibration was caused by ferroelectric switching process. The buildup of these dual‐peak vibrations had been detected, and the asymmetrical evolution of local butterfly loops was observed. It was believed that the observed time delay during the developments of dual‐peak vibrations and butterfly loops should be attributed to the electrode effect. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3282–3287, 2006
Glow Discharges Observed in Capacitive Radio‐Frequency Atmospheric‐Pressure Plasma Jets
Authors: Laimer Johann , Störi Herbert
Published: October 2006

Summary: The APPJ is the subject of intensive recent research. Basically, the APPJ consists of an atmospheric‐pressure RF discharge between two bare metallic electrodes and of a superimposed gas flow consisting predominantly of a rare gas. In its usual operating regime, a uniform glow discharge, which was identified as the α mode of a RF discharge, can be sustained over a wide range of gap spacings and RF powers. Maximum electron densities of 0.22 × 1012 cm−3 were assessed for helium and of 2.75 × 1012 cm−3 for argon by evaluation of electric measurements using a simple equivalent circuit model. At low RF powers, only partial coverage of the electrodes was observed. At high RF powers, a breakdown of the α sheath occurred, and a transition to either a pure γ mode or a coexisting α and γ mode took place. The γ mode covers only a small fraction of the electrode surface. In helium, it was easy to ignite directly a pure α discharge, but not in argon. Due to the high over‐voltage needed, the ignition in argon mostly led to a coexisting α and γ mode. However, through RF power reduction a transition to a pure α discharge can be initiated.

Photograph of the APPJ in operation.

magnified image

Photograph of the APPJ in operation.
A First Principles Density Functional Study of Crystalline FOX‐7 Chemical Decomposition Process under External Pressure
Authors: Hu Anguang , Larade Brian , Abou‐Rachid Hakima , Lussier Louis‐Simon , Guo Hong
Published: October 2006

We report on a first principles analysis of chemical decomposition reaction in a crystalline FOX‐7 (1,1‐diamino‐2,2‐dinitroethylene) molecule, which is a good candidate for insensitive energetic materials. Our calculations are based on variable‐cell shape methods under pressure, density functional theory with localized numerical orbital and pseudopotential, together with ab initio biasing molecular dynamics. The calculated crystal structure and equation of state (pressure vs. volume) up to 8 GPa agrees well with the corresponding experimental data. A chemical decomposition by intermolecular hydrogen transfer is found at higher pressure. This decomposition appears to be driven by a weakening in the chemical hardness. This suggests that the molecular HOMO and LUMO orbital energy difference is decreased when intermolecular hydrogen transfers occur, and for the FOX‐7 crystal the band gap is narrowed with increasing external pressure.