bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of micelles of multiblock copolymers of ethylene oxide and propylene oxide in ion transport during acid bright copper electrodeposition
Authors: Tabakova Nadya , Pojarlieff Ivan , Mircheva Vera , Stejskal Jaroslav 
Published: May 2004

AbstractThe role of micelle formation in the levelling activity of electrolytes for copper electrodeposition was investigated. It was established that micelle formation in the electrolytes caused a dramatic increase in the degree of levelling. The effect takes places via the solubilization of the disodium bis(sulfopropyl) disulfide brightener in copolymer micelles and changes in the distribution of the brightener on cathode surface. The positive effect of a conducting‐polymer additive, a colloidal polyaniline dispersion, on the brightness of electrodeposited copper coatings is discussed.
Pyrazoloquinolines – alternative chromophores for organic LED fabrication
Authors: Niziol Jacek , Danel Andrzej , Gondek Ewa , Armatys Pawel , Sanetra Jerzy , Boiteux Gisele 
Published: May 2004

AbstractIn this paper the synthesis of some new chromophores which could be used in polymer/organic LED fabrication are presented. All of them are pyrazoloquinoline (PAQ) derivatives. Their emission properties were tuned by side group substitution. They were characterized by absorption and photoemission spectroscopy. Some were used, dispersed in poly(N‐vinylcarbazole) (PVK) matrix, as the emissive layer in LED structures.
Influence of morphology on electric conductance in poly(ethylene naphthalene‐2,6‐dicarboxylate)
Authors: Chavez Jose Fidel , Martinez‐Vega Juan Jorge , Zouzou Noureddine , Guastavino Jean 
Published: May 2004

AbstractPolymers find an important field of application in the electrical industry because of their utilization as insulators and dielectrics. The challenge over the last several years has been to make electrical compounds smaller in size. In that way the material morphology is of strategic importance in the performance of new components in relation to their geometry. Therefore, it is important to know the influence of different types of stress on electric properties of the materials.We have studied the influence of the crystallinity on electric conductance of poly(ethylenenaphthalene‐2,6‐dicarboxylate) (PEN), which is increasingly replacing some dielectrics (polypropylene and PET) in certain electric applications.Starting from an amorphous PEN, samples with various crystallinities were obtained and analyzed using DSC in order to determine their thermal characteristics.Moreover, measurements of charge and discharge currents were carried out on PEN samples to characterize their electric properties. The steady state current observed after 120 min, in response to the electric field, shows an increase in the insulator resistivity with the crystallinity. The increase in the crystallinity favors a decrease in the free volume, so the movement of charges is restricted especially by the species of large sizes.
Vibration‐induced energy relaxation in two‐level system
Authors: Menšík Miroslav , Nešpůrek Stanislav 
Published: May 2004

AbstractEnergy decay in a general two‐level electronic system coupled to a vibrational harmonic mode interacting with a thermal bath is studied theoretically. The model assumes a general form of the off‐diagonal elements (in the electronic basis) of the vibrational‐electronic interaction. The cases for constant, linear, and quadratic dependence with respect to the vibrational displacement are investigated. For short‐time regime, fast oscillations corresponding to a coherent energy exchange between electrons and vibrations appear. Their frequency Ω corresponds to the energy difference (ħΩ) between electronic levels. Additionally, for the case of linear or quadratic coupling, the amplitude modulation of the oscillations with the frequency ω equal to that of vibrational motion is found.
Smoking and Parkinson's disease: Systematic review of prospective studies
Authors: Allam Mohamed Farouk , Campbell Michael J. , Hofman Albert , Del Castillo Amparo Serrano , Fernández‐Crehuet Navajas Rafael 
Published: May 2004

AbstractWe estimated the pooled risk of tobacco smoking for Parkinson's disease (PD). Inclusion criteria included systematic searches of MedLine, PsycLIT, Embase, Current Contents, previously published reviews, examination of cited reference sources, and personal contact and discussion with several investigators expert in the field. Published prospective studies on PD and cigarette smoking. When two or more studies were based on an identical study, the study that principally investigated the relationship or the study that was published last was used. Seven prospective studies were carried out between 1959 and 1997, of which six reported risk estimates. Four cohorts were based on standardised mortality rates, which were exclusively of male. Only one study included risk estimates for both males and females separately. The risk of ever smoker was 0.51 (95% confidence interval, 0.43 to 0.61). There was an obvious protective effect of current smoking in the pooled estimate (relative risk, 0.35; 95% CI, 0.26–0.47). Former smokers had lower risk compared with never smokers (relative risk, 0.66; 95% CI, 0.49–0.88). Although our pooled estimates show that smoking is inversely associated with the risk of PD, the four prospective studies that were based on follow‐up of mortality of smokers had many limitations. Further studies evaluating the association between smoking and PD in women are strongly needed. © 2004 Movement Disorder Society
Asymmetric hydration of alkenes catalyzed by wool‐palladium complex
Authors: Xue Lei , Jia Bin , Tang Li , Ji Xiao Feng , Huang Mei Yu , Jiang Ying Yan 
Published: May 2004

AbstractA wool‐palladium complex has been found to be able to catalyze the asymmetric hydration of 1‐octene to (S)‐(+)‐2‐octanol and 1‐decene to (R)‐(+)‐2‐decanol under 1 atm N2 and at 70°C. The optical yields were greatly affected by Pd content in wool‐palladium complex, reaction time and so on, when the proper conditions were selected, (S)‐(+)‐2‐octanol and (R)‐(+)‐2‐decanol could be obtained in 83.2 and 75.6%e.e. optical yield respectively. This chiral natural biopolymer‐palladium complex catalyst was very easy to prepare and could be reused several times without appreciable change in catalytic activity. Copyright © 2004 John Wiley & Sons, Ltd.
Ion conductive characteristics of DNA containing PEO chains covalently bound on nucleic acid bases
Authors: Nishimura Naomi , Kokubo Satoko , Ohno Hiroyuki 
Published: May 2004

AbstractIn order to prepare flexible and ion conductive deoxyribonucleic acid (DNA) films without phase separation, DNA was modified with poly(ethylene oxide) (PEO). PEOs with molecular weight of 150 to 2000 were fixed to the amino groups of nucleic acid bases in DNA (PEO‐DNA). Brittle DNA films turned flexible after PEO modification, and the highest ionic conductivity was obtained when PEO with molecular weight of 1000 was modified. Though Na+, counter cation of phosphate group, was expected to migrate in these PEOx‐DNA hybrids as a carrier ion, ionic conductivity was only 1.3 × 10−6 S cm−1. Addition of salts to PEO1000‐DNA considerably improved the ionic conductivity, and sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) was the best salt for this purpose. When NaTFSI, 5 mol% to the oxyethylene (OE) unit, was mixed with PEO1000‐DNA, the highest ionic conductivity of 1.77 × 10−5 S cm−1 was observed at 30°C. Copyright © 2004 John Wiley & Sons, Ltd.
A comparative study of thermal ageing characteristics of poly(ethylene‐co‐vinyl acetate) and poly(ethylene‐co‐vinyl acetate)/carbon black mixture
Authors: Çopuroğlu Mehmet , Şen Murat 
Published: May 2004

AbstractIn this comparative study, the effect of carbon black (CB) on the thermal ageing characteristics of poly(ethylene‐co‐vinyl acetate) (EVA) was investigated. EVA, containing 13% vinyl acetate (VA), and poly(ethylene‐co‐vinyl acetate)/carbon black mixture (EVA/CB) containing 13% VA and 1% CB were aged at 85°C in air up to 30 weeks. Sol‐gel analysis experiments were made to determine the percentage gelation of both virgin and aged samples. FT‐IR measurements were performed to follow the chemical changes which took place in the samples during ageing. Dynamic and isothermal thermogravimetric studies were performed for determination of the thermal stabilities of virgin and aged samples.Sol‐gel analysis results showed that EVA itself has a tendency to form a gel under thermal treatment, whereas EVA/CB never becomes a gel when being thermally aged under the same conditions. As a result of FT‐IR measurements, some oxidation products such as ketone, lactone and vinyl species were observed through thermal ageing of EVA. It is also clear that these kind of oxidation products did not appear to a considerable extent in EVA/CB. Thermal analysis experiments exhibit that thermal stability of EVA decreased through thermal ageing; whereas that of EVA/CB remained almost unchanged. Copyright © 2004 John Wiley & Sons, Ltd.
Fluorinated polyamides and poly(amide imide)s based on 1,4‐bis(4‐amino‐2‐trifluromethylphenoxy)benzene, aromatic dicarboxylic acids, and various monotrimellitimides and bistrimellitimides: Syntheses and properties
Authors: Yang Chin‐Ping , Chen Ya‐Ping , Woo E. M. 
Published: May 2004

AbstractA CF3‐containing diamine, 1,4‐bis(4‐amino‐2‐trifluromethylphenoxy) benzene (I), was prepared from hydroquinone and 2‐chloro‐5‐nitrobenzotrifluoride. Imide‐containing diacids (Va–h and VIa,b) were prepared through the condensation reaction of amino acids, aromatic diamines, and trimellitic anhydride. Then, a series of soluble fluorinated polyamides (VIIa–h) and poly(amide imide)s (VIIIa–h and Xa,b) were synthesized from I with various aromatic diacids (IIa–h) and imide‐containing diacids (Va–h and VIa,b) via direct polycondensation with triphenyl phosphate and pyridine. The polyamides and poly(amide imide)s had inherent viscosities of 1.00–1.70 and 0.79–1.34 dL/g, respectively. All the synthesized polymers showed excellent solubility in amide‐type solvents such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, and N‐dimethylformamide and afforded transparent and tough films via solvent casting. Polymer films of VIIa–h, VIIIa–h, and Xa,b had tensile strengths of 91–113 MPa, elongations to break of 8–40%, and initial moduli of 2.1–2.8 GPa. The glass‐transition temperatures of the polyamides and poly(amide imide)s were 254–276 and 255–292 °C, respectively, and the imide‐containing poly(amide imide)s had better thermal stability than the polyamides. The polyamides showed higher transparency and were much lighter in color than the poly(amide imide)s, and their cutoff wave numbers were below 400 nm. In comparison with isomeric IXc–h, poly(amide imide)s VIIIc–h exhibited less coloring and showed lower yellowness indices. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3116–3129, 2004
Influence of substituents on the kinetics of epoxy/aromatic diamine resin systems
Authors: Liu Heping , Uhlherr Alfred , Varley Russell J. , Bannister Michael K. 
Published: May 2004

AbstractEleven different epoxy/diamine systems, including tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM), triglycidyl p‐aminophenol (TGAP), and diglycidyl ether of bisphenol A (DGEBA) with 4,4′‐diaminodiphenylsulfone (DDS), diethyltoluenediamine (DETDA), dimethylthiotoluenediamine (DMTDA), and meta‐phenylenediamine (m‐PDA), were studied with near‐infrared spectroscopy at different temperatures. The reactivities of the epoxies were determined and found to be in the following order when reacted with the same amine: DGEBA > TGAP > TGDDM. When the primary amine was reacted with the same epoxy, the order was DETDA > DDS > DMTDA; for the secondary amine, the order was DETDA > DMTDA > DDS. The relative reaction rates of the secondary amine to the primary amine were compared and discussed in terms of the structural differences and the corresponding substitution effect. It was concluded that the increase in the secondary amine reactivity of DETDA and DMTDA was caused by the deconjugation of the benzene‐ring π electrons from the lone pair on the N atom. The overall order of the secondary amine relative reactivity was DMTDA > DETDA > DDS for the same epoxy and TGDDM > TGAP > DGEBA for the same amine. The m‐PDA systems had no significant positive or negative substitution effects. Molecular orbital calculations were performed, and the results showed the most significant deconjugation effect in the secondary amine of DETDA. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3143–3156, 2004
First‐principle calculations for the active centers in vanadium‐containing chloroperoxidase and its functional models: Geometrical and spectral properties
Authors: Borowski Tomasz , Szczepanik Waldemar , Chruszcz Maksymilian , Brocławik Ewa 
Published: May 2004

AbstractVanadium‐containing haloperoxidases (VXPOs) constitute a group of relatively newly discovered metalloenzymes catalyzing oxidation of halogen anions to hypohalous acids by hydrogen peroxide. The structures of their native and peroxide‐bound forms as well as a reliable functional model system were characterized by X‐ray diffraction crystallography methods. In this work, we focus on two well‐characterized model systems and the active site itself of vanadium‐containing chloroperoxidase from Curvularia inaequalis (VCPO). For the two model systems, we performed geometry optimization and frequency calculations at the B3LYP/LanL2DZ level of theory. In addition, the vertical energies and oscillator strengths for a few lowest electronic transitions were computed with TDDFT. The solvent effect on electronic transitions was modeled either by means of a few explicit water molecules hydrogen‐bonded to studied complexes or by point charges representing them. As the active sites of VXPOs have to be modeled with additional charged groups of amino acids neutralizing the negative vanadium core, we restricted our calculations to DFT optimization and TDDFT calculations for excited states. In this paper, the results of these computations, namely, selected bond lengths and angles, vibrational frequencies, electronic transition energies, and oscillator strengths, are presented and compared with relevant literature data. This comparison, we believe, gives credits to the methodology and models used, which is also of importance for mechanistic considerations. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Sexual Abuse Prevention for Individuals with Mental Retardation: Considerations for Genetic Counselors
Authors: Levy Helen , Packman Wendy 
Published: May 2004

AbstractIt is now widely recognized that children, adolescents, and adults with mental retardation are especially vulnerable to sexual abuse. Because at least 10% of genetic conditions are reported to include mental retardation as a feature, the provision of services to individuals with mental retardation represents a substantial portion of the case load for many genetic counselors. Our objective is to educate genetic counselors and other health professionals about this vulnerable population in order to enhance the frequency and efficacy of inquiry into sexual education and sexual abuse prevention training for patients with mental retardation. The following review article is intended to assist genetic counselors by increasing their knowledge of factors that lead to sexual abuse and provides recommendations for integrating this information into the counseling interaction.
Pharmacodynamic Interaction between Propofol and Remifentanil Regarding Hypnosis, Tolerance of Laryngoscopy, Bispectral Index, and Electroencephalographic Approximate Entropy
Authors: Bouillon Thomas W. , Bruhn Jörgen , Radulescu Lucian , Andresen Corina , Shafer Thomas J. , Cohane Carol , Shafer Steven L. 
Published: May 2004

Background
The purpose of this investigation was to describe the pharmacodynamic interaction between propofol and remifentanil for probability of no response to shaking and shouting, probability of no response to laryngoscopy, Bispectral Index (BIS), and electroencephalographic approximate entropy (AE).

Methods
Twenty healthy volunteers received either propofol or remifentanil alone and then concurrently with a fixed concentration of remifentanil or propofol, respectively, via a target-controlled infusion. Responses to shaking and shouting and to laryngoscopy were assessed multiple times after allowing for plasma effect site equilibration. The raw electroencephalogram and BIS were recorded throughout the study, and AE was calculated off-line. Response surfaces were fit to the clinical response data using logistic regression or hierarchical response models. Response surfaces were also estimated for BIS and AE. Surfaces were visualized using three-dimensional rotations. Model parameters were estimated with NONMEM.

Results
Remifentanil alone had no appreciable effect on response to shaking and shouting or response to laryngoscopy. Propofol could ablate both responses. Modest remifentanil concentrations dramatically reduced the concentrations of propofol required to ablate both responses. The hierarchical response surface described the data better than empirical logistic regression. BIS and AE are more sensitive to propofol than to remifentanil.

Conclusions
Remifentanil alone is ineffective at ablating response to stimuli but demonstrates potent synergy with propofol. BIS and AE values corresponding to 95% probability of ablating response are influenced by the combination of propofol and remifentanil to achieve this endpoint, with higher propofol concentrations producing lower values for BIS and AE.
Parental Auricular Acupuncture as an Adjunct for Parental Presence during Induction of Anesthesia
Authors: Wang Shu-Ming , Maranets Inna , Weinberg Megan E. , Caldwell-Andrews Alison A. , Kain Zeev N. 
Published: May 2004

Background
The purpose of this study was to determine whether parental auricular acupuncture reduces parental preoperative anxiety and thus allows children to benefit from parental presence during induction of anesthesia.

Methods
Mothers of children who were scheduled to undergo surgery were randomly assigned to an acupuncture intervention group (auricular press needles at relaxation, tranquilizer point, and master cerebral point) or a sham acupuncture control group (auricular press needles at the shoulder, wrist, and extraneous auricular point). The intervention was performed at least 30 min before the child's induction of anesthesia. All mothers were present during induction of anesthesia. The behavioral and physiologic anxiety of mothers and children were rated during the perioperative process.

Results
: Multivariable analysis examining maternal anxiety as a function of group found a group-by-time interaction (F1,65 = 4.1, P = 0.04). That is, after induction, maternal anxiety in the acupuncture group was significantly lower (42.9 +/- 10 vs. 49.5 +/- 11; P = 0.014). A multivariate model (F1,65 = 4.8, P =0.031) also showed that children whose mothers received the acupuncture intervention were significantly less anxious on entrance to the operating room (34.9 +/- 20 vs. 47.4 +/- 26; P = 0.03) and during introduction of the anesthesia mask (38.6 +/- 25 vs. 55.6 +/- 31; P = 0.016). There were no significant differences in maternal blood pressure and heart rate between the two groups.

Conclusions
: Auricular acupuncture significantly decreased maternal anxiety during the preoperative period. Children of mothers who underwent acupuncture intervention benefitted from the reduction of maternal anxiety during the induction of anesthesia.
Effects of Imposed Acid–Base Derangement on the Cardiovascular Effects and Pharmacokinetics of Bupivacaine and Thiopental
Authors: Mather Laurence E. , Ladd Leigh A. , Copeland Susan E. , Chang Dennis H.-T. 
Published: May 2004

Background
By changing physicochemical properties such as effective lipophilicity, changes in blood pH could alter the distribution, elimination, and effects of weakly ionizing drugs. The authors examined the outcome of imposed acid-base derangement on cardiovascular effects and myocardial and whole body pharmacokinetics of bupivacaine, a weak base, and thiopental, a weak acid.

Methods
Intravenous infusions of rac-bupivacaine HCl (37.5 mg) or rac-thiopental sodium (250 mg, subanesthetic dose) were administered over 3 min to previously instrumented conscious ewes with normal blood pH, acidemia imposed by lactic acid infusion, or alkalemia imposed by bicarbonate infusion. Hemodynamic and electrocardiographic effects were recorded; arterial and coronary sinus drug blood concentrations were analyzed by chiral high-performance liquid chromatography.

Results
Bupivacaine decreased myocardial contractility, coronary perfusion, heart rate, and cardiac output; however, cardiac output and stroke volume were not as affected by bupivacaine with acidemia. Thiopental decreased myocardial contractility and stroke volume and increased heart rate; acidemia enhanced the tachycardia and produced a greater decrease in stroke volume than with alkalemia. Taken as a whole, the cardiovascular changes were not systematically modified by acid-base derangement. Overall, the tissue distribution of bupivacaine was favored by alkalemia, but thiopental pharmacokinetics were essentially unaffected by acid-base derangement. Acid-base derangement did not influence the kinetics of either drug enantioselectively.

Conclusions
At the doses used, the hemodynamic and electrocardiographic effects of bupivacaine and thiopental were not systematically modified by acid-base derangement, nor were there changes in regional or whole body pharmacokinetics of either drug that were clearly related to acid-base status.
Continuous, Noninvasive, and Localized Microvascular Tissue Oximetry Using Visible Light Spectroscopy
Authors: Benaron David A. , Parachikov Ilian H. , Friedland Shai , Soetikno Roy , Brock-Utne John , van der Starre Peter J. A. , Nezhat Camran , Terris Martha K. , Maxim Peter G. , Carson Jeffrey J. L. , Razavi Mahmood K. , Gladstone Hayes B. , Fincher Edgar F. , Hsu Christopher P. , Clark F. Landon , Cheong Wai-Fung , Duckworth Joshua L. , Stevenson David K. 
Published: May 2004

Background
The authors evaluated the ability of visible light spectroscopy (VLS) oximetry to detect hypoxemia and ischemia in human and animal subjects. Unlike near-infrared spectroscopy or pulse oximetry (SpO2), VLS tissue oximetry uses shallow-penetrating visible light to measure microvascular hemoglobin oxygen saturation (StO2) in small, thin tissue volumes.

Methods
In pigs, StO2 was measured in muscle and enteric mucosa during normoxia, hypoxemia (SpO2 = 40-96%), and ischemia (occlusion, arrest). In patients, StO2 was measured in skin, muscle, and oral/enteric mucosa during normoxia, hypoxemia (SpO2 = 60-99%), and ischemia (occlusion, compression, ventricular fibrillation).

Results
In pigs, normoxic StO2 was 71 +/- 4% (mean +/- SD), without differences between sites, and decreased during hypoxemia (muscle, 11 +/- 6%; P < 0.001) and ischemia (colon, 31 +/- 11%; P < 0.001). In patients, mean normoxic StO2 ranged from 68 to 77% at different sites (733 measures, 111 subjects); for each noninvasive site except skin, variance between subjects was low (e.g., colon, 69% +/- 4%, 40 subjects; buccal, 77% +/- 3%, 21 subjects). During hypoxemia, StO2 correlated with SpO2 (animals, r2 = 0.98; humans, r2 = 0.87). During ischemia, StO2 initially decreased at -1.3 +/- 0.2%/s and decreased to zero in 3-9 min (r2 = 0.94). Ischemia was distinguished from normoxia and hypoxemia by a widened pulse/VLS saturation difference (Delta < 30% during normoxia or hypoxemia vs. Delta > 35% during ischemia).

Conclusions
VLS oximetry provides a continuous, noninvasive, and localized measurement of the StO2, sensitive to hypoxemia, regional, and global ischemia. The reproducible and narrow StO2 normal range for oral/enteric mucosa supports use of this site as an accessible and reliable reference point for the VLS monitoring of systemic flow.