bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical relationships between downloads and citations at the level of individual documents within a single journal
Authors: Moed Henk F. 
Published: June 2005

AbstractStatistical relationships between downloads from ScienceDirect of documents in Elsevier's electronic journal Tetrahedron Letters and citations to these documents recorded in journals processed by the Institute for Scientific Information/Thomson Scientific for the Science Citation Index (SCI) are examined. A synchronous approach revealed that downloads and citations show different patterns of obsolescence of the used materials. The former can be adequately described by a model consisting of the sum of two negative exponential functions, representing an ephemeral and a residual factor, whereas the decline phase of the latter conforms to a simple exponential function with a decay constant statistically similar to that of the downloads residual factor. A diachronous approach showed that, as a cohort of documents grows older, its download distribution becomes more and more skewed, and more statistically similar to its citation distribution. A method is proposed to estimate the effect of citations upon downloads using obsolescence patterns. It was found that during the first 3 months after an article is cited, its number of downloads increased 25% compared to what one would expect this number to be if the article had not been cited. Moreover, more downloads of citing documents led to more downloads of the cited article through the citation. An analysis of 1,190 papers in the journal during a time interval of 2 years after publication date revealed that there is about one citation for every 100 downloads. A Spearman rank correlation coefficient of 0.22 was found between the number of times an article was downloaded and its citation rate recorded in the SCI. When initial downloads—defined as downloads made during the first 3 months after publication—were discarded, the correlation raised to 0.35. However, both outcomes measure the joint effect of downloads upon citation and that of citation upon downloads. Correlating initial downloads to later citation counts, the correlation coefficient drops to 0.11. Findings suggest that initial downloads and citations relate to distinct phases in the process of collecting and processing relevant scientific information that eventually leads to the publication of a journal article.
Chiral aspects of the human metabolism of ethosuximide
Authors: Millership J. S. , Mifsud J. , Galea D. , McRoberts W. C. , Hamilton J. T. G. 
Published: June 2005

AbstractEthosuximide is a chiral drug substance primarily indicated for the treatment of absence seizures. This drug is used clinically as the racemate. The human urinary metabolites of ethosuximide (I) have been studied using chiral gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The metabolites identified were the previously reported unchanged ethosuximide (I) enantiomers, all four stereoisomers of 2‐(1‐hydroxyethyl)‐2‐methylsuccinimide (II), and the four stereoisomers of 2‐ethyl‐3‐hydroxy‐2‐methylsuccinimide (III). Through chemical derivatization methodology and GC/MS (using electron impact ionization [EI] and chemical ionization [CI] techniques) two enantiomers of a previously unreported metabolite of ethosuximide, 2‐ethyl‐2‐hydroxymethylsuccinimide (VI), have been identified. Copyright © 2005 John Wiley & Sons, Ltd.
Local heating of human skin by millimeter waves: Effect of blood flow
Authors: Alekseev S.I. , Radzievsky A.A. , Szabo I. , Ziskin M.C. 
Published: June 2005

AbstractWe investigated the influence of blood perfusion on local heating of the forearm and middle finger skin following 42.25 GHz exposure with an open ended waveguide (WG) and with a YAV mm wave therapeutic device. Both sources had bell‐shaped distributions of the incident power density (IPD) with peak intensities of 208 and 55 mW/cm2, respectively. Blood perfusion was changed in two ways: by blood flow occlusion and by externally applied vasodilator (nonivamide/nicoboxil) cream to the skin. For thermal modeling, we used the bioheat transfer equation (BHTE) and the hybrid bioheat equation (HBHE) which combines the BHTE and the scalar effective thermal conductivity equation (ETCE). Under normal conditions with the 208 mW/cm2 exposure, the cutaneous temperature elevation (ΔT) in the finger (2.5 ± 0.3 °C) having higher blood flow was notably smaller than the cutaneous ΔT in the forearm (4.7 ± 0.4 °C). However, heating of the forearm and finger skin with blood flow occluded was the same, indicating that the thermal conductivity of tissue in the absence of blood flow at both locations was also the same. The BHTE accurately predicted local hyperthermia in the forearm only at low blood flow. The HBHE made accurate predictions at both low and high perfusion rates. The relationship between blood flow and the effective thermal conductivity (keff) was found to be linear. The heat dissipating effect of higher perfusion was mostly due to an apparent increase in keff. It was shown that mm wave exposure could result in steady state heating of tissue layers located much deeper than the penetration depth (0.56 mm). The surface ΔT and heat penetration into tissue increased with enlarging the irradiating beam area and with increasing exposure duration. Thus, mm waves at sufficient intensities could thermally affect thermo‐sensitive structures located in the skin and underlying tissue. Bioelectromagnetics 26:489–501, 2005. © 2005 Wiley‐Liss, Inc.
Numerical modeling and dosimetry of the 35 mm Petri dish under 46 GHz millimeter wave exposure
Authors: Zhao Jianxun , Wei Zhenggang 
Published: June 2005

AbstractExperimental studies on effects of millimeter wave (MMW) exposure on cells cultured in Petri dishes have attracted interest in recent decades. To improve the quantification of the biological responses toward the MMW energy, an accurate and precise MMW dosimetry is to be provided. By using the finite difference time domain (FDTD) method, the numerical dosimetry is performed for a typical 35 mm Petri dish under 46 GHz continuous MMW exposure from an irradiator of a specified power pattern. With the aim of building a precise model, the meniscus at the interface between the culture solution and the Petri dish sidewall is taken into account, followed by the modeling of smooth edges of the Petri dish. The trilinear interpolation is introduced to assist the FDTD method to obtain a more precise dosimetric assessment. The specific absorption rate (SAR) distributions in the cornea cells covered by culture solution in the Petri dish are calculated and compared to display the effects of using Petri dish models of various precision and the trilinear interpolation on dosimetry results. In addition, the SAR distribution in the cells is analyzed to study its homogeneity. The results indicate that the precise Petri dish model and the application of the trilinear interpolation are helpful in improving the precision of numerical dosimetry. It is also revealed that the inhomogeneity of the SAR distribution is well beyond neglect, which deserves cautious consideration in experiments investigating MMW effects on cells invitro. Bioelectromagnetics 26:481–488, 2005. © 2005 Wiley‐Liss, Inc.
Skin temperature increase caused by a mobile phone: A methodological infrared camera study
Authors: Straume Aksel , Oftedal Gunnhild , Johnsson Anders 
Published: June 2005

AbstractMobile phone users often complain about burning sensations or a heating of the ear region. The increase in temperature may be due to thermal insulation by the phone, heating of the mobile phone resulting from its electrical power dissipation, and radio frequency (RF) exposure. The main objective of this study was to use infrared (IR) camera techniques to find how much each of these factors contributes to the increase in skin temperature resulting from the use of one GSM 900 phone. One subject, a healthy male took part in the study. He was holding the phone in a normal position when the phone was switched off, when it was switched on but with the antenna replaced by a 50 Ω load to eliminate the RF exposure, and when it was transmitting RF fields. The output power could be fixed, and the minimal and the maximal power levels of the phone were used. The study was designed as a double blind experiment. The changes in temperature after 15 and 30 min of mobile phone use were calculated on the exposed side of the head relative to the unexposed side. The insulation and the electrical power dissipation lead to statistically significant rises in the skin temperature, while the RF exposure did not. Bioelectromagnetics 26:510–519, 2005. © 2005 Wiley‐Liss, Inc.
Predictors of operative morbidity and mortality in gastric cancer surgery
Authors: Park D J , Lee H-J , Kim H-H , Yang H-K , Lee K U , Choe K J 
Published: June 2005

Abstract

Background
The aim of this study was to identify factors that predict morbidity and mortality in gastric cancer surgery.

Methods
Data on 719 consecutive patients who underwent operations for gastric cancer at Seoul National University Hospital between January and December 2002 were reviewed.

Results
Overall morbidity and mortality rates were 17·4 per cent (125 patients) and 0·6 per cent (four patients) respectively, and the rates of surgical and non-surgical complications were 14·7 per cent (106 patients) and 3·3 per cent (24 patients). Morbidity rates were higher in patients aged over 50 years (odds ratio (OR) 1·04 (95 per cent confidence interval (c.i.) 1·02 to 1·06)), when the gastric tumour was resected with another organ (36 per cent for combined resection versus 15·4 per cent for gastrectomy only; OR 3·25 (95 per cent c.i. 1·76 to 6·03)) and when gastrojejunostomy was used for reconstruction after subtotal gastrectomy (17·0 per cent for Billroth II versus 9·5 per cent for Billroth I; OR 2·00 (95 per cent c.i. 1·05 to 3·79)). Only three patients (2·8 per cent) with a surgical complication underwent reoperation, two for adhesive obstruction and one for intra-abdominal bleeding.

Conclusion
Age, combined resection and Billroth II reconstruction after radical subtotal gastrectomy were independently associated with the development of complications after gastric cancer surgery.
Hydroxymethylglutaryl co-enzyme A reductase inhibition attenuates endotoxin-mediated inflammatory responses
Authors: Joyce M , Casey R , Gang C , Winter D , Kelly C J , Bouchier-Hayes D J 
Published: June 2005

AbstractBackgroundThe aim of this study was to investigate whether inhibition of hydroxymethylglutaryl co-enzyme A reductase attenuates leucocyte–endothelial cell interactions and alters expression of endothelial constitutive nitric oxide synthase (ecNOS) and inducible nitric oxide synthase (iNOS) following exposure to endotoxin.MethodsMale Sprague–Dawley rats were randomized into control, lipopolysaccharide (LPS) and pravastatin + LPS groups (seven per group). Pravastatin sodium was gavaged at 0·4 mg per kg per day for 5 days, after which LPS 15 mg/kg was administered via the jugular vein. Intravital microscopy was used to determine leucocyte–endothelial cell interactions.ResultsFollowing the administration of LPS there was a significant reduction in leucocyte rolling velocity at 10 min (mean(s.e.m.) 69(3) versus 102(6) per cent of baseline value; P = 0·041), an increase in the number of adherent leucocytes at 10 min (4·5(0·5) versus 2·8(0·3) per 100 µm; P = 0·044) and an increase in the number of leucocytes undergoing transendothelial migration at 30 min (4·2(0·4) versus 1·7(0·4) per field; P = 0·008) compared with controls. Pretreatment with pravastatin significantly attenuated LPS-induced leucocyte–endothelial cell interactions (rolling velocity 89(6) per cent at 10 min, P = 0·038; adherent leucocytes 3·0(0·5) per 100 µm at 10 min, P = 0·038; migrating leucocytes 1·9(0·5) per field at 30 min, P = 0·001). This endothelial protection was associated with maintenance of ecNOS and reduced iNOS expression within mesenteric tissues.ConclusionThese data show that pravastatin produces anti-inflammatory effects in response to injurious stimuli by attenuation of leucocyte–endothelial cell interactions.
Predictors of operative death after oesophagectomy for carcinoma
Authors: Abunasra H , Lewis S , Beggs L , Duffy J , Beggs D , Morgan E 
Published: June 2005

AbstractBackgroundOesophagectomy for carcinoma provides a chance of cure but carries significant risk. This study defined risk factors for death after oesophageal resection for malignant disease.MethodsBetween 1990 and 2003, 773 oesophagectomies for oesophageal cancer were performed. Continuous variables were categorized into quartiles for analysis. Predictors of operative mortality were identified by univariate and multiple logistic regression analysis.ResultsThe operative mortality rate was 4·8 per cent (37 of 773). In univariate analysis, advanced age, reduced forced expiratory volume in 1 s (FEV1), reduced forced vital capacity, presence of diabetes and tumour located in the upper third of the oesophagus were associated with a higher mortality rate. Multivariate analysis identified age (highest relative to lowest quartile, odds ratio (OR) 4·87 (95 per cent confidence interval (c.i.) 1·35 to 17·55); P = 0·009), tumour position (upper third relative to other locations, OR 4·23 (95 per cent c.i. 1·06 to 16·86); P = 0·041) and FEV1 (lowest relative to highest quartile, OR 4·72 (95 per cent c.i. 1·01 to 21·99); P = 0·018) as independent predictors of death.ConclusionAdvanced age, impaired preoperative respiratory function and a tumour high in the oesophagus are associated with a significantly increased risk of death after oesophagectomy for carcinoma.
Simultaneous quantification of six ephedrines in a Mahwang preparation and in urine by high‐performance liquid chromatography
Authors: Chan Kuei Hui , Pan Ryh‐Nan , Hsu Mei‐Chich 
Published: June 2005

AbstractA rapid and reliable high‐performance liquid chromatographic method was developed and validated for the simultaneous determination of norephedrine (NE), norpseudoephedrine (NPE), ephedrine (E), pseudoephedrine (PE), methylephedrine (ME) and methylpseudoephedrine (MPE) in both a Mahwang traditional Chinese medicine (TCM) preparation and in urine using α‐ethylbenzylamine as the internal standard. The method uses a Spherisorb C18 column for an isocratic elution in a tetraethylammoniumphosphate‐methanol mobile phase at a wavelength of 206 nm. The limits of detection of NE, NPE, E, PE, ME and MPE in sample solutions ranged from 0.1 to 0.3 µg[sol ]mL at a signal‐to‐noise ratio of 3. The within‐day precision as calculated from the Mahwang TCM preparation and urine samples was below 6.2 and 1.4% for each analyte. The between‐day precision as calculated from the Mahwang TCM preparation and urine samples was below 6.8 and 5.9% for each analyte. The between‐day accuracy as determined from the Mahwang TCM preparation and urine samples was below 2.2 and 6.8% for each analyte. The recoveries for six compounds, obtained with compounds spiked into the Mahwang TCM preparation and urine, were found to be more than 93.6%. This method can be successfully applied to doping and excretion rate studies. Copyright © 2005 John Wiley & Sons, Ltd.
Kinetic and NMR Spectroscopic Studies of Chiral Mixed Sodium/Lithium Amides Used for the Deprotonation of Cyclohexene Oxide
Authors: Sott Richard , Granander Johan , Williamson Carl , Hilmersson Göran 
Published: June 2005

AbstractThe mixed‐metal complex formed from n‐butylsodium, n‐butyllithium, and a chiral amino ether has been studied by NMR spectroscopy. Three different mixed‐metal amides were used as chiral bases for the deprotonation of cyclohexene oxide. The selectivity and initial rate of reaction were compared for sodium–amido ethers, lithium–amido ethers, and mixtures of sodium and lithiumamido ethers in diethyl ether and tetrahydrofuran, respectively. The mixed sodium/lithium amides are more reactive than the single sodium and lithium amides, whereas the stereoselectivities are higher when lithium amides are used. The alkali‐metal/γ‐amido ethers exhibit both higher initial reaction rates and stereoselectivities than their β‐amido ether analogues. NMR spectroscopic studies of mixtures of n‐butylsodium (nBuNa), n‐butyllithium (nBuLi), and the γ‐amino ethers in diethyl ether show the exclusive formation of dimeric mixed‐metal amides. In diethyl ether, the lithium atom of the mixed‐metal amide is internally coordinated and the sodium atom is exposed to solvent; however, in tetrahydrofuran, both metals are internally coordinated.
Molecular modelling of the inclusion complexes between β‐cyclodextrin and (R)/(S)‐methylphenobarbitone and its application to HPLC
Authors: Durham David G. , Liang Hongxi 
Published: May 2005

AbstractMolecular modelling of β‐cyclodextrin and optimisation of its potential energy suggests that a favoured conformation is that distorted from a symmetrical torus. The inclusion of water molecules into the torus cavity simulates the increased stability in an aqueous solvent. Complexes of β‐cyclodextrin with (R)‐ and (S)‐enantiomers of methylphenobarbitone have been modelled and energetically optimised by the application of molecular mechanics. The simulations suggests that the guest molecules adopt an orientation in which the phenyl ring is projected into the torus cavity, with in each case the plane of the ring parallel to a longer axis of the distorted torus and slightly displaced from the axis through the torus cavity. It is suggested that the asymmetry in the macrocyclic ring contributes to chiral recognition as a result of additional discriminatory binding to the barbiturate ring residue of each enantiomer, which occupy different 3D geometries. The enantiomers form complexes of different minimum potential energies. The resulting difference in complex stability can be related to the behaviour of β‐cyclodextrin, as a mobile phase additive in reverse‐phase HPLC to effect chiral separation of rac‐medthylphenobarbitone during chromatography. © 1994 Wiley‐Liss, Inc.
Are Conical Intersections Responsible for the Ultrafast Processes of Adenine, Protonated Adenine, and the Corresponding Nucleosides?
Authors: Brøndsted Nielsen Steen , Sølling Theis I. 
Published: June 2005

AbstractExcited‐state potential energy surfaces of adenine, protonated adenine, and their N9‐methylated analogs are explored by means of a complete active space (CAS) and time‐dependent density functional theory (TD‐DFT) study to understand the dynamics associated with internal conversion. After photoexcitation of the ground‐state molecules to the S1 state, the nuclear motions that are responsible for taking the wavepacket out of the Franck–Condon region are either an HN9/CN9 stretch or a ring‐puckering motion that leads to pyramidalization. These motions lead to accessible conical intersections with the ground‐state surface. The results are used to successfully interpret previous measurements on the photodissociation of adenosine 5′‐monophosphate nucleotide anions and cations, where the latter react in a highly nonstatistical manner.
On the Redox Chemistry of GeI Bromide
Authors: Schnepf Andreas 
Published: June 2005

AbstractFirst results on the redox chemistry of GeI bromide are reported herein. During the attempt to solubilize GeIBr, which is synthesized in preparative scale using a co‐condensation technique of the high‐temperature molecule GeIBr, a redox reaction with the solvent acetone occurs. During this unexpected redox reaction GeI is oxidized to GeIV and acetone is reductively coupled to 1,1‐dimethyl‐3‐oxobutan‐1‐yl. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
In Situ XAS and XRD Studies on the Structural Evolution of Ammonium Paratungstate During Thermal Decomposition
Authors: Kirilenko Olga , Girgsdies Frank , Jentoft Rolf E. , Ressler Thorsten 
Published: June 2005

AbstractThe bulk structural evolution during the decomposition of ammonium paratungstate (APT) under various oxidizing and reducing gases was elucidated by the complementary techniques, in situ XAS, in situ XRD, and TG/DSC, combined with mass spectrometry. In the temperature range from 300 to 650 K, the decomposition of APT proceeds nearly independently of the gas employed. At higher temperatures, an oxidizing gas results in the formation of crystalline triclinic WO3 as the majority phase at 773 K, while mildly reducing gases (propene, propene and oxygen, and helium) result in the formation of partially reduced and highly disordered tungsten bronzes. No further reduction is observed under propene or helium, and this indicates a strongly hindered oxygen mobility in the tungsten oxide lattice in the temperature range employed. The decomposition of APT under hydrogen results in the formation of WO2 and, eventually, tungsten metal. During the thermal treatment of APT, major changes occur at ca. 500 K where a complete structural rearrangement takes place that results in the destruction of the polyoxotungstate ion of APT and the formation of a tungsten oxide bronze. The rather low temperature for the formation of a three‐dimensional lattice compared to the thermal treatment of common polyoxomolybdate precursors indicates the lower stability of the precursor and intermediates as ligands are removed. For tungsten to act as a potential structural or electronic promoter in molybdenum oxide based catalysts, tungsten needs to be incorporated in regular molybdenum oxide structures already at a very early stage of the catalyst preparation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A New Series of Homologous Cluster Complexes [Mo3(M'EPh3)Q4Cl4(H2O)5] (M' = Ni, Pd; E = P, As, Sb; Q = S, Se)
Authors: Sokolov Maxim N. , Chubarova Elena V. , Hernandez‐Molina Rita , Clausén Maria , Naumov Dmitry Yu. , Vicent Cristian , Llusar Rosa , Fedin Vladimir P. 
Published: June 2005

AbstractCluster aqua complexes [Mo3(M'Cl)S4(H2O)9]3+ (M' = Ni, Pd) react with EPh3 (E = P, As, Sb) in HCl/CH3OH to give neutral [Mo3(M'EPh3)S4Cl4(H2O)5] (M' = Pd, E = P (1), E = As (2), E = Sb (3); M' = Ni, E = P (4), E = As (5); E = Sb (6). [Mo3(PdPPh3)Se4Cl4(H2O)5] (7) was also obtained. X‐ray crystal structures were determined for 3, 4 and 5. The role of supramolecular interactions in crystal packing is discussed. ESI‐MS spectra were also studied and were used to follow the coordination of the solvent molecules at Mo sites and to assess relative strength of bonding in the clusters. Thermal properties were studied for 4 and 5. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Mono‐ and Bilayered Lead(II)–bpno Polymers with Unusual Low Energy Emission Properties (bpno = 4,4'‐Bipyridine N,N'‐Dioxide)
Authors: Xu Yanqing , Yuan Daqiang , Han Lei , Ma En , Wu Mingyan , Lin Zhengzhong , Hong Maochun 
Published: June 2005

AbstractReaction of 4,4'‐bipyridine N,N'‐dioxide (bpno) and lead(II) nitrate with or without dicyanamido ions (dca) in aqueous solution yielded polymeric complexes {Pb2(bpno)4(dca)2(NO3)2Pb2(bpno)4(NO3)4·5H2O}n (1) and {Pb(bpno)(NO3)2·H2O}n (2), respectively. The single‐crystal X‐ray analyses show that the structures of both complexes consist of dinuclear PbII units which are bridged through bpno ligands in novel modes to extend their topologies. Compound 1 exhibits a bilayered rhombus grid, while 2 displays a monolayered rhombus grid. The different excitations of solid samples of 1 and 2, at room temperature, produced intense emission bands which are almost the same in appearance with peak maxima at 616 nm and 617 nm, respectively. Both low‐energy emissions were determined to be phosphorescence by their long decay lifetime at room temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)