bluuebunny/crossref_metadata_2025_split huggingface dataset:
An effective hopping model for weakly interacting π systems: Electronic structure of stacked polyaromatic hydrocarbons
Authors: Lázár Armand , Surján Péter R. , Paulsson Magnus , Stafström Sven 
Published: August 2002

AbstractParameters for effective hopping integrals are extracted from ab initio Hartree–Fock calculations on model systems. These effective hoppings can be used to describe the attractive part of the interaction of loosely bonded π‐electron systems of various orientations, such as interchain hoppings in conjugated polymers or those between two‐dimensional graphitic sheets. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem 84: 216–225, 2001
Fast characterization of intact proteins using a high‐throughput eight‐channel parallel liquid chromatography/mass spectrometry system
Authors: Feng Bingbing , Patel Arun H. , Keller Paul M. , Slemmon J. Randall 
Published: August 2002

AbstractThe preparation of protein substrates requires that a large number of chromatographic fractions be analyzed for the presence of reactants, products and by‐products. Analyses using linear matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) or single column liquid chromatography/mass spectrometry (LC/MS) have been inadequate because of mass resolution or throughput. Therefore, a high‐throughput method employing an eight‐channel parallel reverse‐phase LC/MS system was developed. This system is capable of screening fractions from preparative ion‐exchange chromatography with the required mass accuracy and throughput so that the protein purification process can be monitored in a relatively short period of time. As an example, the purification and analysis of an acylated protein with a molecular weight of 8.9 kDa is described and the detection of a contaminating by‐product that differs in size by less than 20 Da is demonstrated. Using the current instrumentation and approach, it is practical to analyze 50 protein‐containing fractions from column chromatography in less than 1 hour using parallel LC/MS. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of pyridoquinoline derivatives by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry
Authors: Picó Y. , Font G. , Balaña‐Fouce R. , Ordóñez C. , Abbas D. , Barbe J. 
Published: August 2002

AbstractA method using liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (LC/APCI‐MS) has been developed for the characterization and determination of pyridoquinoline derivatives 4,6‐bis(dimethylaminoethylamino)‐2,8,10‐trimethylpyrido[3,2‐g]quinoline, 4,6‐bis(dimethylaminoethoxy)‐2,8,10‐trimethylpyrido[3,2‐g]quinoline and 4,6‐bis[(dimethylaminoethyl)thio]‐2,8,10‐trimethylpyrido[3,2‐g] quinoline, all with potential antitumor properties. LC separation was performed on a conventional C18 column using a binary mobile phase composed of acetonitrile and 50 mM aqueous ammonium formate at pH 3. The APCI mass spectra obtained showed that proton addition giving [M + H]+ was the common mode of ionization to the amino‐ and thiopyridoquinolines, whereas the alkoxypyridoquinoline was identified by the main formation of the [M − (C2H3)N(CH3)2 + H]+, followed by the [M + H]+ ion. The LC separation conditions and MS detection parameters were optimized for the determination. The analytical method was also applied to the determination of these pyridoquinoline derivatives in fetal calf serum using liquid‐liquid extraction with dichloromethane. Acceptable recovery values were obtained, ranging between 45 and 98%. Copyright © 2001 John Wiley & Sons, Ltd.
Electrospray ionization detection of inherently nonresponsive epoxides by peptide binding
Authors: Cech Nadja B. , Krone Jennifer R. , Enke Christie G. 
Published: August 2002

AbstractA small organic molecule that is inherently nonresponsive to electrospray analysis, 1,3‐butadiene diepoxide, was analyzed via electrospray ionization (ESI) by binding it to various peptides and observing the product at the characteristic mass shift. The epoxide reacted only with peptides with arginines in their sequence, most likely through a base‐catalyzed ring opening to form a covalently bound product. A calibration curve linear over 3 orders of magnitude was generated for the butadiene diepoxide/peptide adduct. Several other epoxides were also reacted with the peptide of choice (angiotensin II), and adducts of these epoxides with the peptide were observed as well, demonstrating the versatility of this method for the analysis of small epoxides. This study demonstrates the possibility of assaying epoxides bound to peptides or proteins in biological samples. Furthermore, it demonstrates an important concept that could be applied to other analytical problems in electrospray: the ability to react an analyte that is nonresponsive to electrospray analysis with an analyte well suited for the technique, and accomplish quantitation based on the adduct formed between the two. Copyright © 2001 John Wiley & Sons, Ltd.
Quantitative estimates of precision for molecular isotopic measurements
Authors: Jasper John P. 
Published: August 2002

AbstractAt least three methods of calculating the random errors or variance of molecular isotopic data are presently in use. The major components of variance are differentiated and quantified here into least three to four individual components. The measurement of error of the analyte relative to a working (whether an internal or an external) standard is quantified via the statistical pooled estimate of error. A statistical method for calculating the total variance associated with the difference of two individual isotopic compositions from two isotope laboratories is given, including the variances of the laboratory (secondary) and working standards, as well as those of the analytes. An abbreviated method for estimation of of error typical for chromatographic/isotope mass spectrometric methods is also presented. Copyright © 2001 John Wiley & Sons, Ltd.
From passive to active dynamic walking
Authors: Ohta Hiroki , Yamakita Masaki , Furuta Katsuhisa 
Published: August 2002

AbstractThis paper is concerned with a walking robot with knees on level ground imitating the passive walking on a given slope. Basic principle of a proposed control method is that dynamics of the active walking robot is matched to that of the passive walking one. However, since it is hard for the knee‐jointed walking robot to successively or robustly realize a stable passive walking on the downhill slope, the passive walking robot is first actively controlled to continue to walk with an actuator at the hip. Then the dynamics of the walking robot on the level grand is matched to that of the stabilized passive walking robot on the slope by implementing actuators at the ankles as well as at the hip. Copyright © 2001 John Wiley & Sons, Ltd.
Factors contributing to attitude exchange amongst preservice elementary teachers
Authors: Palmer David H. 
Published: August 2002

AbstractPrevious research has shown that elementary education majors often dislike science and lack confidence in their ability to teach it. This is an important problem because students who hold these attitudes are likely to avoid teaching science, or teach it poorly, when they become teachers. It is therefore necessary to identify preservice elementary teachers who hold negative attitudes towards science, and attempt to convert these attitudes to positive before they become teachers. This study was designed to identify students whose attitudes had changed from negative to positive (i.e., attitude exchange had occurred) after participating in a one‐semester elementary science education course, and to identify the course factors that were responsible. Four participants were individually interviewed. The transcripts indicated that attitude exchange had occurred for each of the four students. Each student described several features of the course that had a positive influence. These were of three main types: personal attributes of the tutor, specific teaching strategies, and external validation. It was proposed that many of the individual factors were effective because they represented either “performance accomplishments” or “vicarious experience” as defined by Bandura (Psychological Review, 84, 1977, 191–215). © 2001 John Wiley & Sons, Inc. Sci Ed 86:122–138, 2001.
A wizard source of expertise in XPS
Authors: Castle James E. 
Published: August 2002

AbstractX‐ray photoelectron spectroscopy has been in use for the study of materials for 30 years and with considerable success. In retrospect, however, it is clear that the many insights arising from work undertaken in the initial decade (the 1970s) are not well known to new users of the technique. Many of the simpler aids to interpretation, e.g. the use of shake‐up satellites, have stood the test of time and of more recent theoretical explanation and could easily be made available through help routines incorporated into the data system. Examples are given of the manner in which the help could be accessed by way of a screen ‘wizard’, which might also provide a stepping stone to the development of a full expert system. Copyright © 2002 John Wiley & Sons, Ltd.
Some statistical issues in modelling pharmacokinetic data
Authors: Lindsey J. K. , Jones B. , Jarvis P. 
Published: August 2002

AbstractA fundamental assumption underlying pharmacokinetic compartment modelling is that each subject has a different individual curve. To some extent this runs counter to the statistical principle that similar individuals will have similar curves, thus making inferences to a wider population possible. In population pharmacokinetics, the compromise is to use random effects. We recommend that such models also be used in data rich situations instead of independently fitting individual curves. However, the additional information available in such studies shows that random effects are often not sufficient; generally, an autoregressive process is also required. This has the added advantage that it provides a means of tracking each individual, yielding predictions for the next observation. The compartment model curve being fitted may also be distorted in other ways. A widely held assumption is that most, if not all, pharmacokinetic concentration data follow a log‐normal distribution. By examples, we show that this is not generally true, with the gamma distribution often being more suitable. When extreme individuals are present, a heavy‐tailed distribution, such as the log Cauchy, can often provide more robust results. Finally, other assumptions that can distort the results include a direct dependence of the variance, or other dispersion parameter, on the mean and setting non‐detectable values to some arbitrarily small value instead of treating them as censored. By pointing out these problems with standard methods of statistical modelling of pharmacokinetic data, we hope that commercial software will soon make more flexible and suitable models available. Copyright © 2001 John Wiley & Sons, Ltd.
Software Maintenance: Concepts and Practice
Authors: Seaman Carolyn B. 
Published: August 2002

AbstractSoftware Maintenance: Concepts and Practice is an excellent paperback book that comprehensively covers a breadth of software maintenance issues. It is more than adequate as a textbook for a university‐level course about software maintenance, although it has a few drawbacks in this respect (in particular a lack of technical guidance on key maintenance concerns such as impact analysis). In addition, it can be a useful reference for software researchers and, to a lesser extent, practitioners. Copyright © 2001 John Wiley & Sons, Ltd.
An empirical study of the influence of departmentalization and organizational position on software maintenance
Authors: Yeh Dowming , Jeng Jing‐Hwa 
Published: August 2002

AbstractDifferences between software development and maintenance imply that software maintenance work should be measured and managed somewhat differently from software development. On the other hand, maintenance programmers frequently perform the same tasks as development programmers do. How to departmentalize maintenance and development is thus becoming an issue. Departmentalization in software development and maintenance can be classified into two categories, maintenance separated from development and maintenance jointly with development. Departmentalization has its strengths and weaknesses. In this work, quantitative empirical methods are applied to investigate the influence of departmentalization on fulfillment opportunity, time allocations of activities, problem occurrences, and management process in software maintenance. Seven hypotheses are formed and tested by statistical methods. The result shows that separate organizations demonstrate specialization in software maintenance, but managerial attitudes also aggravate the potential status difference for such organizations. Other major pitfalls for departmentalization are also identified. Copyright © 2002 John Wiley & Sons, Ltd.
Post‐formal design conversation: designing just and caring educational systemsa
Authors: Horn Raymond A. 
Published: August 2002

AbstractIn the USA, efforts to improve education continue to be poorly designed and disregard the necessity of centering these efforts on paradigms of justice and caring. Change efforts, such as vouchers, standards, rebuilding educational infrastructure, funding and privatization, are systematic at best, and are promoted by ideological and economic special interests who have no concern for the establishment of egalitarian systems. Because of the lack of design and critical concern, the change efforts invariably fail in their attempt to improve the quality of education, and merely sustain existing inequitable situations. Currently, outside of the academic arena, design theory and critical theory have little impact on the contentious debates about the purpose, form, and function of education. Therefore, how can the process of design and the promotion of justice and caring be included in the actual planning and practice of educational change? The argument will be made that processes of design and criticality can become part of the practice of education, and that the quality of education can be equitably improved through the synthesis of idealized systems design and post‐formal thinking. This synthesis, post‐formal design conversation, will be explored by first identifying the aspects of systems design and post‐formal thinking that are related to this synthesis. A discussion of the similarities and differences of post‐formal design conversation and design conversation will further explicate the nature of post‐formal design conversation. Finally, the potential of Opportunity‐Initiated Systems design to become an interventionist strategy, which will promote the inclusion of post‐formal design conversation in educational change initiatives, will by explored. Copyright © 2001 John Wiley & Sons, Ltd.
Doing the right thing: the problems of…Gerard de Zeeuw, academic guerilla
Authors: Glanville Ranulph 
Published: August 2002

AbstractA set of central themes, constituting both a method and an approach, demonstrated in the ‘Problems of…’ conference series over the last quarter century, are extracted from the work of Gerard de Zeeuw. These themes are based in a consideration of and concern for improvement, and an attempt to reduce the frequently negative side effects of attempts at improvement, by creating ‘high‐quality observations’ and empowering those helped by making them actors. Copyright © 2002 John Wiley & Sons, Ltd.
Self‐administration of cocaine and the cocaine analog RTI‐113: Relationship to dopamine transporter occupancy determined by PET neuroimaging in rhesus monkeys
Authors: Wilcox K.M. , Lindsey K.P. , Votaw J.R. , Goodman M.M. , Martarello L. , Carroll F.I. , Howell L.L. 
Published: August 2002

AbstractDopaminergic mechanisms are thought to play a central role in the reinforcing effects of cocaine. The present study examined the reinforcing effects of 3β‐(4‐chlorophenyl)tropane‐2β‐carboxylic acid phenyl ester (RTI‐113), a long‐acting, selective, high‐affinity dopamine uptake inhibitor. Additionally, the effects of RTI‐113 pretreatment on cocaine self‐administration were determined. Monkeys were trained to respond under a second‐order schedule for intravenous cocaine administration (0.10 or 0.17 mg/kg/infusion). When responding was stable, cocaine (0.0030–1.0 mg/kg/infusion) and RTI‐113 (0.010–0.30 mg/kg/infusion) were substituted for the cocaine training dose. Cocaine and RTI‐113 were equipotent for their reinforcing effects. However, cocaine maintained higher response rates in two of the three monkeys tested. When administered as a pretreatment, RTI‐113 (0.10–0.30 mg/kg) dose‐dependently reduced responding maintained by two doses of cocaine. Drug effects on behavior were related to dopamine transporter (DAT) occupancy in monkey striatum during neuroimaging with positron emission tomography. DAT occupancy was determined by displacement of 8‐(2‐[18F]fluroethyl)2β‐carbomethoxy‐3β‐(4‐chlorophenyl)nortropane (FECNT). DAT occupancy was between 65–76% and 94–99% for doses of cocaine and RTI‐113 that maintained maximum response rates, respectively. DAT occupancy did not differ markedly across RTI‐113 pretreatment doses and ranged between 72–84%. The results suggest that the pharmacokinetic profile of RTI‐113 (i.e., long‐acting) may influence its ability to maintain self‐administration, and therefore its abuse liability. Additionally, high DAT occupancy is required for RTI‐113 to reduce cocaine‐maintained responding. Synapse 43:78–85, 2002. © 2001 Wiley‐Liss, Inc.
Mobility management: from GPRS to UMTS
Authors: Lin Yi‐Bing , Haung Yieh‐Ran , Chen Yuan‐Kai , Chlamtac Imrich 
Published: August 2002

AbstractThis paper describes mobility management for the third‐generation mobile networks. We focus on the evolution from General Packet Radio Service (GPRS) to Universal Mobile Telecommunication System (UMTS). In this evolution, the radio access network UTRAN has been introduced, and radio‐related management is moved from the core network to UTRAN. We elaborate on how this architecture change affects the mobility management functionality, including the attach and detach procedures, location update, serving radio network controller relocation and intersystem change between GPRS and UMTS. Copyright © 2001 John Wiley & Sons, Ltd.
Cooperative functions of the mannoprotein‐encoding genes in the biogenesis and maintenance of the cell wall in Saccharomyces cerevisiae
Authors: Horie Tetsuro , Isono Katsumi 
Published: August 2002

AbstractTo elucidate the roles of genes involved in the cell wall biogenesis and function in Saccharomyces cerevisiae, we isolated and characterized mutants that were lethal in a strain in which the SED1 gene encoding a cell wall mannoprotein was disrupted. Thus, double mutants of SED1 and either MNN9 or MNN10 were unable to grow and YOL155c on a multicopy plasmid could suppress their synthetic lethality. A Yol155cp–GFP fusion protein was found to localize to the cell wall, suggesting that it might also be a cell wall mannoprotein. Subsequently, we analysed the effects of the shut‐off of SED1 in a sed1 and mnn9 double mutant: cells after the shut‐off showed anomalous cellular morphology and died in the mitotic M phase. From these and other results, we postulate that these genes function cooperatively with each other and in a cell cycle‐dependent manner in the biogenesis and maintenance of cell wall in S. cerevisiae. Copyright © 2001 John Wiley & Sons, Ltd.
Nitric Oxide, Mitochondria, and Cell Death
Authors: Brown Guy C. , Borutaite Vilmante 
Published: August 2002

AbstractNO or its derivatives (reactive nitrogen species: RNS) have three types of actions on mitochondria: 1) reversible inhibition of mitochondrial respiration at cytochrome oxidase by NO, and irreversible inhibition at multiple sites by RNS; 2) stimulation of mitochondrial production of superoxide, hydrogen peroxide, and peroxynitrite by NO; and 3) induction of mitochondrial permeability transition (MPT) by RNS. Similarly there are three main roles of mitochondria in NO‐induced cell death: a) NO inhibition of respiration can induce necrosis (or excitotoxicity in neurons) and inhibit apoptosis if glycolysis is insufficient to compensate, b) RNS‐ or oxidant‐induced signal transduction or DNA damage may activate the mitochondrial pathway to apoptosis, and c) RNS‐induced MPT may induce apoptosis or necrosis.
Regulation of HIF by the von Hippel‐Lindau Tumour Suppressor: Implications for Cellular Oxygen Sensing
Authors: Mole D. R. , Maxwell P. H. , Pugh C. W. , Ratcliffe P. J. 
Published: August 2002

AbstractHypoxia‐inducible factor (HIF) is central in coordinating many of the transcriptional adaptations to hypoxia. Composed of a heterodimer of α and β subunits, the α subunit is rapidly degraded in normoxia, leading to inactivation of the hypoxic response. Many models for a molecular oxygen sensor regulating this system have been proposed, but an important finding has been the ability to mimic hypoxia by chelation or substitution of iron. A key insight has been the recognition that HIF‐ α is targeted for degradation by the ubiquitin‐proteasome pathway through binding to the von Hippel‐Lindau tumour suppressor protein (pVHL), which forms the recognition component of an E3 ubiquitin ligase complex leading to ubiquitylation of HIF‐ α. Importantly, the classical features of regulation by iron and oxygen availability are reflected in regulation of the HIF‐ α/p VHL interaction. It has recently been shown that HIF‐ α undergoes an iron‐ and oxygen‐dependent modification before it can interact with pVHL, and that this results in hydroxylation of at least one prolyl residue (HIF‐1 α, Pro 564). This modification is catalysed by an enzyme termed HIF‐prolyl hydroxylase (HIF‐PH), and compatible with all previously described prolyl‐4‐hydroxylases HIF‐PH also requires 2‐oxoglutarate as a cosubstrate. The key position of this hydroxylation in the degradation pathway of HIF‐ α, together with its requirement for molecular dioxygen as a co‐substrate, provides the potential for HIF‐PH to function directly as a cellular oxygen sensor. However, the ability of these enzyme(s) to account for the full range of physiological regulation displayed by the HIF system remains to be defined.
Integrated Electrochemical Carbon Capture and Utilization by Redox‐Active Amine Grafted Gold Nanoparticles
Authors: Yan Tao , Liu Shuo , Liu Zhikun , Sun Jie , Kang Peng 
Published: January 2024

AbstractElectrochemical carbon capture and utilization (eCCU) from flue gas CO2 could avoid high energy consumption and capital input in conventional capture, storage, and utilization, which is a promising approach for achieving negative emissions and producing “e‐chemicals.” However, low CO2 concentration and leftover O2 in the flue gas presumably lowers the eCCU performance. Herein, redox‐active 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole (AMT) functionalized gold nanoparticles are synthesized to achieve integrated electrochemical capture and reduction of CO2 in simulated flue gas (SFG, 15% CO2, 4% O2, balanced with N2), achieving maximum CO Faradaic efficiency of 80.2% at −0.45 V versus RHE in H‐type cell, and 66.0% at voltage of 2.7 V in a full cell, respectively. The AMT ligand can capture CO2 by strong interaction with CO2 in the reduced state and serve as a selective layer to suppress O2 reduction, which provides the ability of electrochemical carbon capture from SFG and significantly decreases energy required for CO2 electro‐reduction.