bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereospecific synthesis of specifically deuterated metoprolol enantiomers from chiral starting materials
Authors: Umesha Shetty H. , Murthy Satya S. , Nelson Wendel L. 
Published: October 2006

AbstractEnantiomers 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

Abstract5‐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

AbstractLeu‐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

AbstractFour 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

AbstractThe 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

AbstractBenzimidazole 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

AbstractA 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

Abstract[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

AbstractA “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

AbstractOxidation 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

AbstractEven 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

AbstractSummary: 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.magnified imageStaining 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

AbstractSummary: 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.magnified imageEnzyme 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

AbstractSummary: 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.magnified imageNormalized 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

AbstractThe 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

AbstractThis 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

AbstractAs 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

AbstractBy 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

AbstractQ‐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

AbstractOntology 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.
An annotation paradigm: The social hyperlink
Authors: Ciszek Thomas , Fu Xin 
Published: October 2006

AbstractWe 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

AbstractThere 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

AbstractThe 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

AbstractWe 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

AbstractThe 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.