bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivity of silicon‐doped carbon nanotubes toward small gaseous molecules in the atmosphere
Authors: Guo Guanlun , Wang Fang , Sun Hui , Zhang Dongju 
Published: August 2007

AbstractThe reactivities of the pristine and silicon doped (Si‐doped) single‐walled carbon nanotubes (CNTs) toward small gaseous molecules in the atmosphere, such as formaldehyde, carbon monoxide, and hydrogen sulfide, were studied by performing density functional theory calculations. Compared with the physisorptions on the pristine (8, 0) CNT, these small molecules present strong chemical interactions with the Si‐doped (8, 0) tube. Doping intrinsic CNTs with silicon is expected to be a potential strategy for improving the property of pristine CNTs and expanding the application of CNTs in nanoscience and nanotechnology. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A polarizable high‐rank quantum topological electrostatic potential developed using neural networks: Molecular dynamics simulations on the hydrogen fluoride dimer
Authors: Houlding S. , Liem S. Y. , Popelier P. L. A. 
Published: August 2007

AbstractThe HF molecule is a simple polar system that serves as a prototype for developing new potentials. Here we build on earlier work [Liem and Popelier, J Chem Phys 2003, 119, 4560] in which a high‐rank multipolar potential was used to simulate liquid HF. That work was the first example of high‐rank multipole moments (up to hexadecapole) being employed in conjunction with multipolar Ewald summation in a molecular dynamics simulation. This potential is now extended with polarization, which is delivered by artificial neural networks. The neural nets predict how atomic multipole moments change as the position of neighboring molecules vary. This novel approach is successfully tested on the HF dimer in vacuum. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Characterization of phenolic compounds in Erigeron breviscapus by liquid chromatography coupled to electrospray ionization mass spectrometry
Authors: Zhang Yufeng , Shi Peiying , Qu Haibin , Cheng Yiyu 
Published: August 2007

AbstractErigeron breviscapus is an important herbal drug for the treatment of cardiovascular and cerebral vessel diseases. In this study, phenolic compounds were extracted from the whole plant of E. breviscapus and analyzed by high‐performance liquid chromatography/electrospray ionization mass spectrometry. A total of 53 compounds were identified or tentatively characterized based on their UV and mass spectra. These compounds included caffeoylquinic acids (CQAs), CQA glucosides, malonyl‐CQAs, acetyl‐CQAs, caffeoyl‐2,7‐anhydro‐3‐deoxy‐2‐octulopyranosonic acids (CDOAs), caffeoyl‐2,7‐anhydro‐2‐octulopyranosonic acids (COAs), flavones, flavonols and flavonones. Most of them were reported for the first time from E. breviscapus and nineteen of them belonged to new compounds. The MSn spectra of CQA glucosides were similar to CQAs and they were discriminated by their retention times. No caffeic acid related ions (X, Y and Z) were observed in MSn spectra of acyl‐CQAs compared to those of CQAs. Fragment ions (2,5O−, 3,6O− and 4,6O−) corresponding to ring cleavage were shown in MSn spectra of CDOAs and COAs, characteristic of this class of compounds. The 5,6,7‐trihydroxyl‐substituted flavones were dominant in E. breviscapus. Their [AH]− ions underwent the loss of a molecule of H2O, followed by the loss of CO, which was used to discriminate from other hydroxyl‐substituted flavones. Our results are the first comprehensive analysis of E. breviscapus constituents and will be helpful for the quality control of the herb of E. breviscapus and its related preparations. Copyright © 2007 John Wiley & Sons, Ltd.
Studies of iridoid glycosides using liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Ren Lingling , Xue Xingya , Zhang Feifang , Wang Yongcan , Liu Yanfang , Li Cunman , Liang Xinmiao 
Published: August 2007

AbstractFragmentation pathways of five iridoid glycosides have been studied by using electrospray ionization multi‐stage tandem mass spectrometry (ESI‐MSn). The first‐stage MS data of the five iridoid glycosides were compared. The MS spectra showed that the adduct ions of iridoid glycosides and the formate anion were diagnostic ions to distinguish iridoid glycosides with a carboxyl group at the C‐4 position or an ester group at the C‐4 position. The MS fragmentation pathways of the five iridoid glycosides were also studied. Analyzing the product ion spectra of iridoid glycosides, some neutral losses were observed, such as H2O, CO2 and glucose residues, which were very useful for the identification of the functional groups in the structures of iridoid glycosides. Furthermore, specific loss of one molecule of methyl 3‐oxopropanoate or 3‐oxopropanic acid was firstly discussed, which corresponded to the isomerization of the hemiacetal group in the structure of iridoid aglycone. According to the fragmentation mechanisms and HPLC/MSn data, the structures of five iridoid glycosides in a crude extract of Gardenia jasminoisdes fruit have been identified. Three compounds were compared with standards and the other two were identified as shanzhiside and genipin gentibioside by their MSn data without standard compounds. In order to further validate the veracity of the deduction, genipin gentiobioside was isolated from the extract of Gardenia jasminoisdes fruit using Purification Factory and was further identified by C‐ and H‐NMR. Copyright © 2007 John Wiley & Sons, Ltd.
Using high‐concentration trypsin‐immobilized magnetic nanoparticles for rapid in situ protein digestion at elevated temperature
Authors: Jeng Jingyueh , Lin Mon‐Fang , Cheng Fong‐Yu , Yeh Chen‐Sheng , Shiea Jentaie 
Published: August 2007

AbstractWe describe an innovative approach – using a high concentration of trypsin‐modified magnetic nanoparticles (TMNPs) – for the rapid and efficient digestion of proteins at elevated temperature. The required digestion time could be reduced to less than 10 s. After digestion, the TMNPs were collected magnetically from the sample solution for reuse and the digested peptides were characterized using matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. Protein digestion was optimized when using the TMNPs (5 µg/µL) at 57°C; a significantly high peptide coverage was achieved for protein identification (e.g., 98% for lysozyme). Although a high concentration of TMNPs was used for digestion, the short digestion time led to much lower amounts of trypsin peptides being produced through self‐digestion. As a result, interference in the mass spectrometric detection of the peptide ions was reduced significantly. Copyright © 2007 John Wiley & Sons, Ltd.
A single glucose derivative suitable for gas chromatography/mass spectrometry and gas chromatography/combustion/isotope ratio mass spectrometry
Authors: Jackson Sarah J. , Waterhouse John S. , Bluck Leslie J. C. 
Published: August 2007

AbstractThe incorporation of stable isotopes improves the assessment of glucose metabolism and, with some researchers using two tracers, 2H‐glucose assessed by gas chromatography/mass spectrometry (GC/MS) and 13C‐glucose by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), a common derivative for both is advantageous. The most commonly used derivatives for GC/MS are inappropriate for GC/C/IRMS as additional functional groups dilute the label. We therefore considered the suitability of six derivatives for both GC/MS and GC/C/IRMS. Glucose alkylboronates were prepared by adding the appropriate alkylboronic acid (butyl‐ or methylboronic acid) in pyridine to desiccated glucose. The derivatisation was completed by reacting this with either (a) acetic anhydride or trifluoroacetic anhydride (acetate derivatives) or (b) bis(trimethylsilyl)trifluoroacetamide BSTFA (TMS derivatives). All six derivatives were assessed using GC/MS and 13C GC/C/IRMS.Neither TMS derivative exhibited any signal intensity in the molecular ion, although a M‐15 ion showed good agreement between experimental and theoretical data and, whilst still low in intensity, could be suitable for isotope work. Similarly, none of the acetate derivatives showed any intensity at the molecular ion although three key fragmentation series were identified. The most attractive sequence, initiated by the loss of 1,2 cyclic boronate, resulted in the main fragment ion of interest, m/z 240, corresponding to the fluorinated methylboronate derivate. Minimal carbon and hydrogen atoms are added to this derivative making it an excellent choice for stable isotope work, while proving suitable for analysis by both GC/MS and GC/C/IRMS. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of hydrolytic degradation products of nerve agents by injection port fluorination in gas chromatography/mass spectrometry for the verification of the Chemical Weapons Convention
Authors: Pardasani Deepak , Mazumder Avik , Gupta Arvinda K. , Kanaujia Pankaj K. , Tak Vijay , Dubey Devendra K. 
Published: August 2007

AbstractRetrospective detection and identification of markers of chemical warfare agents are important aspects of verification of the Chemical Weapons Convention. Alkyl alkylphosphonic acids (AAPAs) and alkylphosphonic acids (APAs) are important markers of nerve agents. We describe the development and optimization of a new gas chromatography/mass spectrometry (GC/MS) injection port fluorination method for the derivatization of AAPAs and APAs. The process involved the injection of acids with trifluoroacetic anhydride in GC/MS, where acids are converted into their corresponding volatile fluorides. Various reaction conditions such as fluorinating agent, injection port temperature and splitless time were optimized. The maximum reaction efficiency of the acids with trifluoroacetic anhydride was observed at 230°C injection port temperature with a splitless time of 2 min. APAs showed best analytical efficiencies at 400°C injection port temperature, while the other conditions were similar to those of AAPAs. The linearities of response for APAs and AAPAs were in the range of 1–25 and 5–100 µg mL−1, respectively, with limits of detection ranging from 500 pg to 800 ng mL−1. Copyright © 2007 John Wiley & Sons, Ltd.
Allowing for uncertainty due to missing data in meta‐analysis—Part 2: Hierarchical models
Authors: White Ian R. , Welton Nicky J. , Wood Angela M. , Ades A. E. , Higgins Julian P. T. 
Published: August 2007

AbstractWe propose a hierarchical model for the analysis of data from several randomized trials where some outcomes are missing. The degree of departure from a missing‐at‐random assumption in each arm of each trial is expressed by an informative missing odds ratio (IMOR). We require a realistic prior for the IMORs, including an assessment of the prior correlation between IMORs in different arms and in different trials. The model is fitted by Monte Carlo Markov Chain techniques. By applying the method in three different data sets, we show that it is possible to appropriately capture the extra uncertainty due to missing data, and we discuss in what circumstances it is possible to learn about the IMOR. Copyright © 2007 John Wiley & Sons, Ltd.
Allowing for uncertainty due to missing data in meta‐analysis—Part 1: Two‐stage methods
Authors: White Ian R. , Higgins Julian P. T. , Wood Angela M. 
Published: August 2007

AbstractAnalysis of a randomized trial with missing outcome data involves untestable assumptions, such as the missing at random (MAR) assumption. Estimated treatment effects are potentially biased if these assumptions are wrong. We quantify the degree of departure from the MAR assumption by the informative missingness odds ratio (IMOR). We incorporate prior beliefs about the IMOR in a Bayesian pattern‐mixture model and derive a point estimate and standard error that take account of the uncertainty about the IMOR. In meta‐analysis, this model should be used for four separate sensitivity analyses which explore the impact of IMORs that either agree or contrast across trial arms on pooled results via their effects on point estimates or on standard errors. We also propose a variance inflation factor that can be used to assess the influence of trials with many missing outcomes on the meta‐analysis. We illustrate the methods using a meta‐analysis on psychiatric interventions in deliberate self‐harm. Copyright © 2007 John Wiley & Sons, Ltd.
On the role of acquisition premium in acquisition research
Authors: Laamanen Tomi 
Published: August 2007

AbstractSeveral studies argue that paying high acquisition premia is value destroying for acquirer shareholders. There are studies that have even used the size of premium as a measure of low‐quality decision making. This paper departs from the earlier research and shows that acquisition premia may be justified when target firms' resources are difficult for the market to value. An analysis of a sample of 458 acquisitions demonstrates that although higher premia are paid for R&D‐related assets, the premia do not cause negative abnormal returns. Abnormal returns are more strongly affected by the overall target price levels independent of premia. Copyright © 2007 John Wiley & Sons, Ltd.
Buckling behavior improvement of steel plate shear wall systems
Authors: Sabouri‐Ghomi Saeid , Kharrazi Mehdi H. K. , Mam‐Azizi Salah‐E‐Deen , Sajadi Ramin Asad 
Published: August 2007

AbstractTo improve buckling stability and to prevent early elastic buckling of infill plates, vertical and horizontal plate stiffeners are designed for steel plate shear wall (SPSW) systems. Furthermore, effective design of stiffeners for SPSW systems results in improved structural behavior, such as increase of stiffness, capacity and energy absorption. In this paper, the effect of stiffeners is studied on SPSW structural behavior and consequently a rational method is proposed to determine the minimum required moment of inertia for stiffeners resulting in local buckling mode of the infill plate. The proposed requirement is then compared to results obtained from tests previously conducted, as well as those gained from finite element (FE) analyses performed for this study. Copyright © 2007 John Wiley & Sons, Ltd.
Seismic demand of an RC special moment frame building
Authors: Kim Taewan , Kim Jinkoo 
Published: August 2007

AbstractSeismic design of a building is usually performed by using a linear static procedure. However, the actual behavior of a building subjected to earthquake is inelastic and dynamic in nature, and inelastic dynamic analysis is required to evaluate the safety of the structure designed by the current design codes. In this study, an RC special moment‐resisting frame building was designed by IBC 2003. Maximum plastic rotation, dissipated energy of some selected members, and the drift demand were calculated to examine whether the inelastic behavior of the building followed the intention of the design code. In addition, the effect of internal moment‐resisting frames (gravity load resisting system) on resisting lateral load was investigated. According to the analysis result, the building designed by IBC 2003 showed the inelastic behavior intended in the code and satisfied the design drift limit. Copyright © 2007 John Wiley & Sons, Ltd.
Selecting transition process for WLAN security
Authors: Hsu Shih‐Feng , Lin Yi‐Bing 
Published: August 2007

AbstractIn wireless local area network (WLAN), a station (STA) accesses the Internet through an access point (AP). When switching from one AP to another, the STA executes the transition process, which may incur long delay and result in force‐termination for real‐time applications. The IEEE 802.11r proposes the fast basic service set (BSS) transition to speed up the transiti on process for a STA moving within the same mobility domain (MD). This scheme requires unique MD assignment so that the STA knows whether it should conduct fast BSS transition process (for intra‐MD scenario) or the expensive initial MD association process (for inter‐MD scenario). However, how to guarantee unique MD identifier (MDID) assignment is not mentioned in the specification. This paper proposes a mechanism for IEEE 802.11r fast transition without using MDID, and therefore eliminates the cost for MDID management. Copyright © 2007 John Wiley & Sons, Ltd.
Three successful pregnancies through dietary management of fructose‐1,6‐bisphosphatase deficiency
Authors: Krishnamurthy V. , Eschrich K. , Boney A. , Sullivan J. , McDonald M. , Kishnani P. S. , Koeberl D. D. 
Published: August 2007

SummaryFructose‐1,6‐bisphosphatase (FBPase) deficiency (OMIM 229700) has been characterized as the cause of life‐threatening hypoglycaemia and lactic acidaemia following prolonged fasting. The patient, an adult African‐American woman, presented during the second trimester of her first pregnancy with recurrent episodes of lactic acidaemia and hypoglycaemia. She had recently been admitted to a nearby intensive care unit after presentation with profound hypoglycaemia and lactic acidosis, and was found to be pregnant. The history was remarkable for approximately 30 hospitalizations for hypoglycaemia and acidosis. She had previously undergone liver biopsy at another centre and was diagnosed with a ‘glycogen storage disease’ although no enzyme testing had been done for confirmation. Based on clinical symptoms, a diagnosis of FBPase deficiency was accomplished through gene sequencing, which revealed homozygosity for a panethnic, common mutation, 960/961insG in exon 7. The availability of mutation testing facilitated the confirmation of FBPase deficiency in this patient, obviating liver biopsy for enzyme activity confirmation. The patient underwent three successful pregnancies by strict compliance with dietary management, including nocturnal uncooked cornstarch to manage hypoglycaemia. The pregnancies were complicated by mild gestational diabetes, increased cornstarch requirements, and hypoglycaemia at the time of discharge from the hospital. The three infants had normal birth weights and experienced no complications during the neonatal period. The patient subsequently developed sensorineural hearing loss and early‐onset cognitive impairment, despite compliance with the monitoring and treatment of hypoglycaemia. The experience with multiple pregnancies in this FBPase‐deficient patient provides insight into the management of hypoglycaemia in inherited disorders of gluconeogenesis.
Serum S100B levels in X‐linked adrenoleukodystrophy and Gaucher disease
Authors: Michelakakis H. , Kariyannis C. , Moraitou M. , Dimitriou E. , Sarafidou J. , Papassotiriou I. 
Published: August 2007

SummaryS100B, a small acidic protein, is a member of a multigenic family of calcium‐modulated proteins. It is mainly produced by astrocytes and the secreted protein, depending on its concentration, can exert either trophic or toxic effects. In humans increased S100B levels have been detected in brain trauma and ischaemia, and neurodegenerative, neurometabolic, inflammatory and psychiatric disease. Serum S100B concentrations have been used as markers of brain disease. In the present study S100B serum levels were determined in patients with the neuroinflammatory disease X‐linked adrenoleukodystrophy (X‐ALD) and in patients with both the acute neuronopathic (type II) and the non‐neuronopathic (type I) types of Gaucher disease (GD). Sixteen X‐ALD patients (10 with the childhood, 4 with the adult cerebral forms, 2 asymptomatic) and 22 Gaucher disease patients (19 type I, 3 type II) were studied. No statistically significant differences were observed between the X‐ALD (median 0.13 μg/L, p=0.191) or Gaucher type I patients (median 0.07 μg/L, p=0.095) and controls of similar age (median 0.10 μg/L, n=22). Serum S100B levels of type II Gaucher disease patients were also within the normal for their age range (patients 0.2, 0.22, 0.65; control median 0.81 μg/L, n=44). Lack of clinical symptoms and/or MRI findings in X‐ALD patients was not associated with lower S100B values. Our results indicate that serum S100B levels cannot serve as peripheral marker in the evaluation of brain disease in X‐ALD and GD.
Living with Hereditary Non‐polyposis Colorectal Cancer; Experiences from and Impact of Genetic Testing
Authors: Carlsson C. , Nilbert M. 
Published: August 2007

AbstractHereditary non‐polyposis colorectal cancer (HNPCC) is one of our most common cancer syndromes and an increasing number of individuals live in families with verified hereditary cancer. We conducted an interview study to explore experiences from and perceived impact on life after genetic testing for HNPCC. Three major themes emerged: reactions and emotions, family relations and implications for life. Among the reactions described were suspecting heredity, feelings of guilt, the importance of experiential knowledge, and coping strategies. The impact on family relations was related to perceived responsibility for conveying information, encountering different reactions among family members, and difficulties in communication and relations. The implications described included uncertainty, adaptation, new choices and changes in life, family planning issues, and experiences of surveillance programs. We suggest that the themes and sub‐themes identified should be taken into account during genetic counselling in order to facilitate the spread of information and to prepare family members for the impact on life that knowledge about hereditary cancer may have.
High population density promotes the evolution of ownership
Authors: Horiuchi Shiro 
Published: August 2007

AbstractPrevious studies have discussed the evolution of ownership using the Hawk–Dove–Bourgeois game. Decisive parameters are resource values (V) and contest costs (C). However, ownership may also evolve as a result of the effects of population density. To compare the effects of population density with those of resource values, I created a learning‐based model of a revised Hawk–Dove–Bourgeois game. The game simulates the dynamics of agents that struggle for regions (“territories”) along a line. With appropriate sets of r (resource value) and l (reciprocal of the population density), the model showed that ownership is more likely to evolve when the resource value is small and population density is high. An area containing high‐value resources is likely to accompany high population density. However, simulations showed that population density has stronger effects than resource value on the evolution of ownership.