bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser‐induced Breakdown Detection (LIBD) for the Highly Sensitive Quantification of Aquatic Colloids. Part I: Principle of LIBD and Mathematical Model
Authors: Bundschuh Tobias , Wagner Tobias U. , Köster Rainer 
Published: December 2005

AbstractA new type of Laser‐induced Breakdown Detection (LIBD) is being developed for the direct quantification of aquatic colloids of extremely small sizes at very low concentrations, which are not detectable by the commercial methods currently available. LIBD allows for the detection of colloids in the lower nanometer range. Different statistical and mathematical models are available for the quantification of colloids in aquatic systems. In this double publication (parts I and II), a model based on binomial statistics was employed. This is introduced as the basis of our theoretical descriptions of the experimental data discussed in part II. As a prerequisite, a qualitative and quantitative description of the power density distribution in the focal area of a laser beam is necessary and thus is also presented in this article. Together with the second part, this paper is intended to provide a profound insight into both the theoretical and experimental aspects of the Laser‐induced Breakdown Detection technique, and to show practical applications as well as the latest developments in this field of particle characterization.
Effect of Mechanochemical Processing on Illite Particles
Authors: Yang Huaming , Yang Wuguo , Hu Yuehua , Du Chunfang , Tang Aidong 
Published: December 2005

AbstractDry grinding of illite particles has been investigated by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption techniques. Prolonged grinding results in an amorphous illite structure and the mechanochemical effect markedly promotes a reduction in reflection intensities with increased grinding time. It is confirmed that illite is very susceptible to alteration by grinding. The illite crystal size (d006) appears to reach a limit after 2 h of grinding. N2 adsorption studies indicate that illite ground for 8 h shows a larger average pore diameter than a sample after 4 h grinding or the original illite. It is inferred that grinding is good for the formation of macrostructural pores. Illite grinding results in a decrease in the Brunauer‐Emmet‐Teller (BET) surface area and total pore volume. IR spectroscopy shows a slight alteration in the illite bands after mechanochemical processing and some new bands were detected after 4 or more hours of grinding.
Examining the collision‐induced decomposition spectra of ammoniated triglycerides as a function of fatty acid chain length and degree of unsaturation. II. The PXP/YPY series
Authors: Li Xingwen , Collins Elizabeth J. , Evans Jason J. 
Published: December 2005

AbstractA series of positionally pure triglycerides (TAGs) of the form PXP and YPY, where P is the palmitate moiety and X and Y are large arrays of different fatty acid moieties, is synthesized and analyzed by reversed‐phase high‐performance liquid chromatography/tandem mass spectrometry. The intensities of the collision‐induced decomposition (CID) products of ammoniated TAGs were examined as a function of chain length, degree of unsaturation, double‐bond position, and cis/trans configuration of X and Y. The major CID products, the diglyceride (DAG) fragment ions and the MH+ ions, are plotted as functions of chain length for the saturated and monounsaturated series of X and Y. Different trends for each of these series are observed. Trends in the intensities of these fragment ions are also characterized as a function of degree of unsaturation in the TAGs. In general, the fractional intensities of MH+ increase with increasing degree of unsaturation in the TAGs. MH+ is absent in the CID spectra of triglycerides containing three saturated fatty acid moieties, suggesting that the presence of double bonds fosters the formation of MH+. Double bonds positioned close to the carbonyl carbon along the fatty acid chain promote the formation of the DAG fragment ion corresponding to the loss of the fatty acid. The collection of PXP/YPY data produced in this work is used to test the mechanisms of the formation and decomposition of ammoniated TAGs that were previously presented. The YPY data are used to predict the intensities of the fragment ions in the CID spectra of YPX‐type TAGs. The limitations of the mathematical approach used in these predictions are discussed in context of a broader plan to develop a software platform for comprehensive analysis of complex TAG mixtures. Copyright © 2005 John Wiley & Sons, Ltd.
Determination of ion and neutral loss compositions and deconvolution of product ion mass spectra using an orthogonal acceleration time‐of‐flight mass spectrometer and an ion correlation program
Authors: Grange Andrew H. , Zumwalt Michael C. , Sovocool G. Wayne 
Published: December 2005

AbstractExact masses of monoisotopic ions, and the relative isotopic abundances (RIAs) of ions greater in mass by 1 and 2 Da than the monoisotopic ion, are independent and complementary physical properties useful for distinguishing among elemental compositions of ions possible for a given nominal mass. Using these properties to determine elemental compositions of product ions and neutral losses increases the masses of precursor ions for which unique compositions can be determined. Compositions of the precursor ion, product ion, and neutral loss aid mass spectral interpretation and guide modest chemical literature searches for candidate standards to be obtained for confirmation of tentative compound identifications. This approach is essential for compound characterization or identification due to the absence of commercial libraries of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) product ion spectra. For a series of 34 exact mass measurements, an orthogonal acceleration time‐of‐flight mass spectrometer provided 34 and 29 values accurate to within 2 and 1 mDa, respectively, for ions from eight simulated unknowns with [M+H]+ ion masses between 166 and 319 Da. Of 36 RIA measurements for +1 Da or +2 Da ions, 35 were accurate to within 20% of their predicted values (or to within 0.4 RIA % when the RIA value was less than 1%) in the absence of obvious interferences, in cases where the monoisotopic ion peak areas were at least 1.7 × 105 counts and the ion masses exceeded 141 Da. An ion correlation program (ICP) provided the unique and correct compositions for all but three of the 34 ions studied. Manual inspection of the data eliminated the incorrect compositions. To test the utility of the ICP for deconvoluting composite product ion spectra, all 34 ions were tested for correlation. Six of eight precursor ions were identified as such, while two were compositional subsets of others and were not properly identified. The six precursor ion compositions were still found by the ICP even though ions with masses less than 158 Da were not considered since they could no longer be correlated with a single precursor ion. Finally, two unidentified analytes were characterized, based on data published by others and using the ICP together with mass spectral interpretation. Published in 2005 by John Wiley & Sons, Ltd.
Differentiation of three pairs of aconite alkaloid isomers from Aconitum nagarum var. lasiandrum by electrospray ionization tandem mass spectrometry
Authors: Li Rui , Wu Zhijun , Zhang Fan , Ding Lisheng 
Published: December 2005

AbstractThree pairs of isomers of aconite alkaloids from Aconitum nagarum var. lasiandrum have been investigated by electrospray ionization mass spectrometry (ESI‐MS) and tandem mass spectrometry (MS/MS) employing ion‐trap and quadrupole time‐of‐flight mass spectrometers in positive mode. Based on the differences of their fragmentation pathways and special fragment ions, three pairs of isomers of aconite alkaloids were differentiated. In addition, fragmentation laws of some veatchines and the discrepancy of fragmentation mechanisms between veatchine‐type and aconitine‐type alkaloid were also concluded. In the case of veatchines, a radical would be formed by homolysis of C18C4 or C18H bonds, followed by elimination of a series of C2H2 and C2H4. Moreover, the retro‐Diels‐Alder (RDA) reaction occurred in the E‐ring and double‐electron transfer triggered by the positive charge on C1 led to the formation of diagnostic ions at m/z 216. With regard to aconitine‐type alkaloids, the N‐substituent is not eliminated easily. Although there is no carbonyl group on some aconitine‐type alkaloids, with hydroxyl and methoxyl on C15 and C16 respectively, CO was readily eliminated through tautomerization. Copyright © 2005 John Wiley & Sons, Ltd.
Applications of the regularity lemma for uniform hypergraphs
Authors: Rödl Vojtěch , Skokan Jozef 
Published: December 2005

AbstractIn this article we discuss several combinatorial problems that can be addressed by the Regularity Method for hypergraphs. Based on the recent results of Nagle, Schacht, and the authors, we give here solutions to these problems.In particular, we prove the following: Let ℱ be a k‐uniform hypergraph on t vertices and suppose an n‐vertex k‐uniform hypergraph ℋ︁ contains only o(nt) copies of ℱ. Then one can delete o(nk) edges of ℋ︁ to make it ℱ‐free.Similar results were recently obtained by W. T. Gowers. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Repeatability of autonomic responses to pain anticipation and pain stimulation
Authors: Colloca Luana , Benedetti Fabrizio , Pollo Antonella 
Published: December 2005

AbstractIn this study we address the problem of the repeatability of autonomic responses in the experimental setting. In healthy volunteers, we measured the heart rate (HR) response to pain anticipation and to pain elicited with galvanic stimulation. After evaluation of pain threshold (T), all subjects underwent the same experimental protocol, whereby a painful stimulus at 1.5T was delivered on the forehead following a warning, while the ECG was continuously recorded. The procedure was repeated three times across a three‐week period. The parameters recorded included pain threshold, pain rating, HR response to pain anticipation and HR response to pain. We found a high correlation among the three sessions for all parameters, indicating that, as occurs for pain threshold and pain rating, individual differences in autonomic responses can be reliably reproduced as well, even though significant habituation develops.
Modelling of repeatability phenomena using the stochastic ellipsoid approach
Authors: Brethé Jean-François , Vasselin Eric , Lefebvre Dimitri , Dakyo Brayima 
Published: December 2005

A stochastic ellipsoid modelling of repeatability is proposed for industrial manipulator robots. The covariance matrix of angular position is determined introducing the jump process, which reveals to be a first and second order stationary Gaussian process.From this accurate covariance matrix, the stochastic ellipsoid theory gives the density of position in the workspace around the mean position. Hence the pose repeatability index can be computed in different locations. Computed and experimental repeatability are compared. Experimental repeatability variability is studied. A new “intrinsic repeatability index” is proposed. In conclusion, the modelling reflects well the location and load influence on the repeatability.
Role of cysteine residues in the function of human UDP glucuronosyltransferase isoform 1A1 (UGT1A1)
Authors: Ghosh Siddhartha S. , Lu Yang , Lee Sung W. , Wang Xia , Guha Chandan , Roy-Chowdhury Jayanta , Roy-Chowdhury Namita 
Published: December 2005

Bilirubin glucuronidation, catalysed by UGT1A1 [UGT (UDP glucuronosyltransferase) isoform 1A1, EC 2.4.1.17], is critical for biliary elimination of bilirubin. UGT1A1 deficiency causes CN-1 (Crigler–Najjar syndrome type 1), which is characterized by potentially lethal unconjugated hyperbilirubinaemia. Nucleotide sequence analysis of UGT1A1 in two CN-1 patients revealed that patient A was homozygous for a nt 530 G→A (where nt 530 G→A means guanine to adenine transition at nucleotide 530) mutation, predicting a C177Y substitution, and patient B had a nt 466 T→C mutation on one allele and a nt 1070 A→G mutation on the other, predicting a C156R and a Q357R substitution respectively. All 11 cysteine residues of mature human UGT1A1 are highly conserved in other human UGT isoforms and in rat, mouse and Rhesus monkey UGT1A1, suggesting their functional importance. Expression of mutagenized UGT1A1 plasmids showed that substitution of any of the seven cysteine residues located within the endoplasmic reticulum cisternae (including those mutated in patients A and B) abolished UGT1A1 activity or markedly increased its apparent Km for bilirubin. Substitution of the three cysteine residues within the C-terminal cytosolic tail had minimal effect on basal UGT1A1 activity, but prevented UGT1A1 activation by UDP-GlcNAc. N-Ethylmaleimide did not inhibit UGT1A1 activity in native microsomes, but prevented UGT1A1 activation by UDP-GlcNAc and inhibited the activity in digitonin-permeabilized microsomes. Dithiothreitol did not affect UGT1A1 activity in human liver microsomes. Together, the results suggested that free thiol groups, but not disulphide bonding, of seven cysteine residues within the intracisternal region of human UGT1A1 are important for its catalytic activity, while cysteine residues in the cytosolic domain may be involved in its physiological activation by UDP-GlcNAc.
Inhibition of enzyme activity of and cell-mediated substrate cleavage by membrane type 1 matrix metalloproteinase by newly developed mercaptosulphide inhibitors
Authors: Hurst Douglas R. , Schwartz Martin A. , Jin Yonghao , Ghaffari Mohammad A. , Kozarekar Pallavi , Cao Jian , Sang Qing-Xiang Amy 
Published: December 2005

MT1-MMP (membrane type 1 matrix metalloproteinase, or MMP-14) is a key enzyme in molecular carcinogenesis, tumour-cell growth, invasion and angiogenesis. Novel and potent MMP inhibitors with a mercaptosulphide zinc-binding functionality have been designed and synthesized, and tested against human MT1-MMP and other MMPs. Binding to the MT1-MMP active site was verified by the competitive-inhibition mechanism and stereochemical requirements. MT1-MMP preferred deep P1′ substituents, such as homophenylalanine instead of phenylalanine. Novel inhibitors with a non-prime phthalimido substituent had Ki values in the low-nanomolar range; the most potent of these inhibitors was tested and found to be stable against air-oxidation in calf serum for at least 2 days. To illustrate the molecular interactions of the inhibitor–enzyme complex, theoretical docking of the inhibitors into the active site of MT1-MMP and molecular minimization of the complex were performed. In addition to maintaining the substrate-specificity pocket (S1′ site) van der Waals interactions, the P1′ position side chain may be critical for the peptide-backbone hydrogen-bonding network. To test the inhibition of cell-mediated substrate cleavage, two human cancer-cell culture models were used. Two of the most potent inhibitors tested reached the target enzyme and effectively inhibited activation of proMMP-2 by endogenous MT1-MMP produced by HT1080 human fibrosarcoma cells, and blocked fibronectin degradation by prostate cancer LNCaP cells stably transfected with MT1-MMP. These results provide a model for mercaptosulphide inhibitor binding to MT1-MMP that may aid in the design of more potent and selective inhibitors for MT1-MMP.
The calcium-dependent ATP-Mg/Pi mitochondrial carrier is a target of glucose-induced calcium signalling in Saccharomyces cerevisiae
Authors: Cavero Santiago , Traba Javier , Del Arco Araceli , Satrústegui Jorgina 
Published: December 2005

Sal1p is a mitochondrial protein that belongs to the SCaMC (short calcium-binding mitochondrial carrier) subfamily of mitochondrial carriers. The presence of calcium-binding motifs facing the extramitochondrial space allows the regulation of the transport activity of these carriers by cytosolic calcium and provides a new mechanism to transduce calcium signals in mitochondria without the requirement of calcium entry in the organelle. We have studied its transport activity, finding that it is a carboxyatractyloside-resistant ATP-Mg carrier. Mitochondria from a disruption mutant of SAL1 have a 50% reduction in the uptake of ATP. We have also found a clear stimulation of ATP-transport activity by calcium, with an S0.5 of approx. 30 μM. Our results also suggest that Sal1p is a target of the glucose-induced calcium signal which is non-essential in wild-type cells, but becomes essential for transport of ATP into mitochondria in yeast lacking ADP/ATP translocases.
The effect of N-terminal truncation on double-dimer assembly of goose δ-crystallin
Authors: Lee Hwei-Jen , Lai Young-Hsang , Wu Su-Ying , Chen Yu-Hou 
Published: December 2005

δ-Crystallin is a soluble structural protein in avian eye lenses that confers special refractive properties. In the presence of GdmCl (guanidinium chloride), tetrameric δ-crystallin undergoes dissociation via a dimeric state to a monomeric molten globule intermediate state. The latter are denatured at higher GdmCl concentrations in a multi-state manner. In the present study, the X-ray structure of goose δ-crystallin was determined to 2.8 Å (1 Å=0.1 nm). In this structure the first 25 N-terminal residues interact with a hydrophobic cavity in a neighbouring molecule, stabilizing the quaternary structure of this protein. When these 25 residues were deleted this did not produce any gross structural changes, as judged by CD analysis, but slightly altered tryptophan fluorescence and ANS (8-anilino-1-naphthalenesulphonic acid) spectra. The dimeric form was significantly identified as judged by sedimentation velocity and nondenaturing gradient gel electrophoresis. This mutant had increased sensitivity to temperature denaturation and GdmCl concentrations of 0.3–1.0 M. This protein was destabilized about 3.3 kcal/mol (1 kcal=4.184 kJ) due to N-terminal truncation. After incubation at 37 °C N-terminal truncated proteins were prone to aggregation, suggesting the presence of the unstable dimeric conformation. An important role for the N-terminus in dimer assembly of goose δ-crystallin is proposed.
A Period Study of the Close Binary V508 Ophiuchi
Authors: Albayrak Berahitdin 
Published: December 2005

AbstractThe short-period (0d.34) close binary V508 Oph was observed in 2005 and four new times of minima were derived. All of the available times of minima, including the new ones, covering 69 years were analyzed. It was shown that the period change of the system is very complex. Two possible period oscillations with periods of 24.73 and 9.91 years and amplitudes of about 0.011 and 0.002 day, respectively, were found to superimpose on upward parabolic change, indicating a secular period increase at a rate of dp/dt = 4.24 × 10−9 days yr−1. The mechanisms that could explain the period changes of the system are discussed.
Cloud Imaging from Meteorological Satellites and its Application to Robotic Observing
Authors: Phillips Andre , Ashley Michael C. B. 
Published: December 2005

AbstractSatellite cloud imagery is a standard tool of meteorology, and also of ground-based observational astronomy. Fast access to cloud imagery through the Internet now permits more accurate prediction of local cloud cover than was formerly the case. This is particularly useful for automatic and remotely operated telescopes, where an observer may be at a considerable distance from the telescope itself. Since satellite imagery can now be accessed through the Internet with such ease, direct reception of radio transmissions from weather satellites may seem unnecessary. However, advances in computing power and radio receiver technology permit simple automated receipt of satellite transmissions, particularly from the NOAA series of low Earth orbit satellites. This has the advantage of more up-to-date, and higher resolution, cloud imagery than can be obtained from the Internet. We have operated such a satellite receiving station since 2003 April, and have found it particularly useful when remotely operating our telescopes at Siding Spring Observatory (SSO). By automatically publishing our cloud imagery onto the World Wide Web we have established a resource that is widely used by other local observatories and by the general public.
Towards an Alternative Perspective on Trade and Industrial Policies
Authors: Shafaeddin S. M. 
Published: December 2005

AbstractTrade policy is at a crossroads, as is trade diplomacy, in the form of trade negotiations under the auspicious of the World Trade Organization (WTO). Widespread ‘traditional’ import substitution industrialization (ISI) strategies, which prevailed from the 1950s to the 1970s, failed. Across‐the‐board trade liberalization, recommended by the international financial institutions (IFIs) and neoliberal scholars in the 1980s and 1990s to promote outward‐oriented industrialization and development, fared no better. What is next? Drawing on the experiences of developing countries in trade liberalization and economic reform in recent years, as well as the history of those countries which underwent early industrialization, this article aims to develop an alternative approach to trade and industrial policy by taking a bottom‐up approach. The author presents a national policy framework (that is, a view of what is needed at the national level to catch up in the process of industrialization) and, on that basis, argues for changes in international trade rules.
Increased expression of Toll like receptor 4 on peripheral-blood mononuclear cells in patients with coronary arteriosclerosis disease
Authors: Geng H-L , Lu H-Q , Zhang L-Z , Zhang H , Zhou L , Wang H , Zhong R-Q 
Published: December 2005

SummaryThe family of Toll-like receptors (TLRs) initiates innate immune responses, and Toll-like receptor 4 (TLR4) was considered to be an important player in the initiation and progression of atherosclerotic disease. The aim of the study was to investigate the expression of TLR4 on peripheral-blood mononuclear cells (PBMCs) in patients with coronary arteriosclerosis disease (CAD). We have examined the expression of TLR4 protein and mRNA by flow cytometry (FCM) and real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). In addition, the levels of plasma lipids were determined by automatic biochemistry analyzer. The results showed that the positive rates and the mean mRNA copy number of TLR4 in CAD group were significantly higher than that in controls. But no significant difference was found in the positive rate and the mean mRNA copy number of TLR4 between CAD group with normal level of plasma lipids and the CAD group with abnormal level of plasma lipids. We suggest that expression level of TLR4 on peripheral-blood mononuclear cells is increased in atherosclerotic, but the differential expression of TLR4 has no correlation with the level of plasma lipids.