bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dependency on elementary school caregivers: The role of parental intrusiveness and children's separation anxiety
Authors: Wood Jeffrey J. , Kiff Cara , Jacobs Jeffrey , Ifekwunigwe Muriel , Piacentini John C. 
Published: October 2007

AbstractA theoretical model of children's dependency on teachers and other caregivers in elementary school was tested and supported in this study. Based on attachment theory and social‐cognitive theory, parental intrusiveness and children's separation anxiety were hypothesized to heighten dependent behaviors with school caregivers. Families of children in Grades K–5 participated. Parent‐ and child‐report measures with good psychometric properties were employed. Parental intrusiveness and children's separation anxiety were associated with clingy, dependent relationships with school caregivers in cross‐informant correlational analyses. Intrusiveness and separation anxiety jointly accounted for 18%–29% of the variance in dependency scores. Results are consistent with attachment models of continuity between parent–child relationships and relations with other caregivers. Practice recommendations for teachers and school providers are given. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 823–837, 2007.
Kinetic features of ethylene polymerization over supported catalysts [2,6‐bis(imino)pyridyl iron dichloride/magnesium dichloride] with AlR3 as an activator
Authors: Mikenas Tatiana B. , Zakharov Vladimir A. , Echevskaya Lyudmila G. , Matsko Mikhail A. 
Published: October 2007

AbstractThe effects of polymerization temperature, polymerization time, ethylene and hydrogen concentration, and effect of comonomers (hexene‐1, propylene) on the activity of supported catalyst of composition LFeCl2/MgCl2‐Al(i‐Bu)3 (L = 2,6‐bis[1‐(2,6‐dimethylphenylimino)ethyl] pyridyl) and polymer characteristics (molecular weight (MW), molecular‐weight distribution (MWD), molecular structure) have been studied. Effective activation energy of ethylene polymerization over LFeCl2/MgCl2‐Al(i‐Bu)3 has a value typical of supported Ziegler–Natta catalysts (11.9 kcal/mol). The polymerization reaction is of the first order with respect to monomer at the ethylene concentration >0.2 mol/L. Addition of small amounts of hydrogen (9–17%) significantly increases the activity; however, further increase in hydrogen concentration decreases the activity. The IRS and DSC analysis of PE indicates that catalyst LFeCl2/MgCl2‐Al(i‐Bu)3 has a very low copolymerizing ability toward propylene and hexene‐1. MW and MWD of PE produced over these catalysts depend on the polymerization time, ethylene and hexene‐1 concentration. The activation effect of hydrogen and other kinetic features of ethylene polymerization over supported catalysts based on the Fe (II) complexes are discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5057–5066, 2007
Water‐soluble conjugated polymers: Synthesis and optical properties
Authors: Xie Baohan , Bagui Mahuya , Guo Ruirun , Li Kun , Wang Qing , Peng Zhonghua 
Published: October 2007

AbstractTwo sets of water‐soluble poly(phenylene vinylene)s were synthesized and their optical properties were studied. The aqueous solubility of all these polymers is rendered by pendant sulfonate groups. One set of polymers (polymer I series) contains, in addition to the sulfonate pendants, dimethoxy substituents, while the other (polymer II series) contains oligo(ethylene oxide) side chains. Within each set, polymers containing lithium (Ia and IIa), sodium (Ib and IIb), and potassium (Ic and IIc) counter ions were prepared. The two sets of polymers showed different properties from physical appearance (fiber vs film) to thermal properties and to optical properties. It was found that set I polymers, with shorter side chains, exhibit stronger aggregation in aqueous solutions than set II polymers, which led to their lower fluorescence quantum yields and lower polymer‐to‐MV2+ quenching efficiencies. Within each set, the effect of counter ions on optical properties was noted. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5123–5135, 2007
Effect of the terminal substituent of azobenzene on the properties of ABA triblock copolymers via atom transfer radical polymerization
Authors: Tang Xinde , Gao Longcheng , Fan Xinghe , Zhou Qifeng 
Published: October 2007

AbstractThe effect of the terminal substituent of azobenzene on the properties of ABA triblock copolymers was investigated. For this study, three kinds of azobenzene‐containing monomers with different terminal substituents—6‐[4‐(4‐methoxyphenylazo)phenoxy] hexyl methacrylate, 6‐[4‐(4‐ethoxyphenylazo)phenoxy]hexyl methacrylate, and 6‐[4‐(4‐nitrophenylazo)phenoxy]hexyl methacrylate—were used to synthesize ABA triblock copolymers PMMAzo25–PEG13–PMMAzo25/PMMAzo12–PEG13–PMMAzo12, PEMAzo14–PEG13–PEMAzo14, and PNMAzo14–PEG13–PNMAzo14, respectively, by atom transfer radical polymerization (PMMAzo is poly{6‐[4‐(4‐methoxyphenylazo)phenoxy]hexyl methacrylate}, PEMAzo is poly{6‐[4‐(4‐ethoxyphenylazo)phenoxy]hexyl methacrylate}, and PNMAzo is poly{6‐[4‐(4‐nitrophenylazo)phenoxy]hexyl methacrylate}). These copolymers were characterized with 1H NMR spectroscopy and gel permeation chromatography and exhibited controlled molecular weights and narrow molecular weight distributions. Differential scanning calorimetry and polarizing optical microscopy showed that these copolymers had mesophases. PMMAzo25–PEG13–PMMAzo25 and PMMAzo12–PEG13–PMMAzo12 had a smectic mesophase and a nematic mesophase, whereas both PEMAzo14–PEG13–PEMAzo14 and PNMAzo14–PEG13–PNMAzo14 had a nematic mesophase. This demonstrated that the liquid‐crystalline properties of these copolymers highly depended on the terminal substituent of azobenzene. The photoresponsive behavior of these copolymers was also investigated in tetrahydrofuran solutions, and the influence of the terminal substituents attached to azobenzene was studied. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5190–5198, 2007
Screening of the active site from water by the incoming ligand triggers catalysis and inhibition in serine proteases
Authors: Shokhen Michael , Khazanov Netaly , Albeck Amnon 
Published: October 2007

AbstractThe pKa of the catalytic His57 NεH in the tetrahedral complex (TC) of chymotrypsin with trifluoromethyl ketone inhibitors is 4–5 units higher relative to the free enzyme (FE). Such stable TC's, formed with transition state (TS) analog inhibitors, are topologically similar to the catalytic TS. Thus, analysis of this pKa shift may shed light on the role of water solvation in the general base catalysis by histidine. We applied our QM/SCRF(VS) approach to study this shift. The method enables explicit quantum mechanical DFT calculations of large molecular clusters that simulate chemical reactions at the active site (AS) of water solvated enzymes. We derived an analytical expression for the pKa dependence on the degree of water exposure of the ionizable group, and on the total charge in the enzyme AS, Q(A) and Q(B), when the target ionizable functional group (His57 in this study) is in the acidic (A) and basic (B) forms, respectively. Q2(B) > Q2(A) both in the FE and in the TC of chymotrypsin. Therefore, water solvation decreases the relative stability of the protonated histidine in both. Ligand binding reduces the degree of water solvation of the imidazole ring, and consequently elevates the histidine pKa. Thus, the binding of the ligand plays a triggering role that switches on the cascade of catalytic reactions in serine proteases. Proteins 2008. © 2007 Wiley‐Liss, Inc.
The emerging field of chemical genetics: potential applications for pesticide discovery
Authors: Walsh Terence A 
Published: October 2007

AbstractThe use of small molecules to probe biological systems, generally described as ‘chemical genetics’, has grown considerably in the past 7 years, especially in areas related to human biology and therapeutics. This review describes some aspects of chemical genetics technologies that can be usefully applied to pesticide target discovery and lead generation. The chemical genetics approach (consisting of a phenotype screen, a chemical library and a robust target identification methodology) is compared with conventional and target‐based screening. The outcomes of a chemical genetics approach are novel protein targets coupled with in vivo‐active chemical ligands. The ‘chemistry‐first’ paradigm of the chemical genetics approach can circumvent some of the obstacles that have emerged for the exploitation of novel but chemically unvalidated targets identified from genetic or genomic screens. Some of the advantages and challenges in using chemical genetics approaches are reviewed. Copyright © 2007 Society of Chemical Industry
Effects of insecticide exposure on movement and population size estimates of predatory ground beetles (Coleoptera: Carabidae)
Authors: Prasifka Jarrad R , Lopez Miriam D , Hellmich Richard L , Prasifka Patricia L 
Published: October 2007

AbstractBACKGROUND: Estimates of arthropod population size may paradoxically increase following insecticide applications. Research with ground beetles (Coleoptera: Carabidae) suggests that such unusual results reflect increased arthropod movement and capture in traps rather than real changes in population size. However, it is unclear whether direct (hyperactivity) or indirect (prey‐mediated) mechanisms produce increased movement.RESULTS: Video tracking of Scarites quadriceps Chaudior indicated that brief exposure to lambda‐cyhalothrin or tefluthrin increased total distance moved, maximum velocity and percentage of time moving. Repeated measurements on individual beetles indicated that movement decreased 240 min after initial lambda‐cyhalothrin exposure, but increased again following a second exposure, suggesting hyperactivity could lead to increased trap captures in the field. Two field experiments in which ground beetles were collected after lambda‐cyhalothrin or permethrin application attempted to detect increases in population size estimates as a result of hyperactivity. Field trials used mark–release–recapture methods in small plots and natural carabid populations in larger plots, but found no significant short‐term (<6 day) increases in beetle trap captures.CONCLUSION: The disagreement between laboratory and field results suggests mechanisms other than hyperactivity may better explain unusual changes in population size estimates. When traps are used as a primary sampling tool, unexpected population‐level effects should be interpreted carefully or with additional data less influenced by arthropod activity. Published in 2007 by John Wiley & Sons, Ltd.
The effect of dextromethorphan in preventing cholecalciferol‐induced poison shyness and sickness‐induced anorexia in the laboratory Norway rat
Authors: Gould Elaine M , Holmes Selena J 
Published: October 2007

AbstractBACKGROUND: Overcoming bait and poison shyness is critical to the success of pest control operations against rats and other rodents. The authors hypothesized that the N‐methyl‐D‐aspartate receptor blocker, dextromethorphan, could prevent the acquired memory of sickness and sickness‐induced anorexia resulting from rodents eating poisoned bait.RESULTS: Cholecalciferol (1/4 LD50) was mixed with dextromethorphan and fed to rats on two 2 day sessions, with an 18 day break in between. Dextromethorphan did not prevent poison shyness; during the second poisoning period, both the cholecalciferol only and the cholecalciferol plus dextromethorphan groups had lower intakes of the bait compared with the control and dextromethorphan only groups. In addition to the previously recorded symptoms of cholecalciferol poisoning, the rats in this trial were observed to have nose bleeds, weepy eyes, laboured breathing and, in the case of the cholecalciferol only treated group, a period of decreased water intake followed by a period of increased water intake. There was also a period of increased water intake in the cholecalciferol plus dextromethorphan group.CONCLUSION: Dextromethorphan failed to prevent poison shyness and the anorectic effect of cholecalciferol. However, it did reduce anorexia from 17 days in the cholecaliferol group to 8 days in the cholecalciferol plus dextromethorphan group. Copyright © 2007 Society of Chemical Industry
Electro‐optical characterization of carbon nanotube‐based coatings under CO2 laser irradiation
Authors: Castro M. R. S. , Veith M. , Oliveira P. W. 
Published: October 2007

AbstractConductive coatings made from very thin functionalized (–NH2) multi‐walled carbon nanotubes dispersed in a TiO2‐based sol were irradiated with CO2 laser using different intensities. It was observed that the electrical and optical properties of the film have changed. Laser‐treated films present lower resistivity than the original non‐irradiated coating. We attribute this behavior to a better densification of the nanotubes with the assist of the laser. Films irradiated with CO2 presented a higher refractive index than non‐irradiated coatings, showing the susceptibility of the films in optic‐electronic devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neubau der ÖBB‐Salzachbrücke – ein innovatives, einzigartiges Ingenieurbauwerk in Salzburg
Authors: Scholz Ulrich , Fila Roman , Fink Josef 
Published: October 2007

AbstractDie neue Eisenbahnbrücke über die Salzach ist mehr als ein Brückenbauwerk für die neue S‐Bahn in Salzburg. Ihre gestalterische Formgebung, mit ihrer Stützenteilung und ihrer extrem schlanken Konstruktion sowie die umfangreichen Bauphasen machen die Brücke zu einem einzigartigen Architektur‐ und Ingenieurbauwerk. Nach Fertigstellung wird das Bauwerk zusätzlich zur Leistungssteigerung für die Österreichischen Bundesbahnen auch noch eine wesentlich verbesserte Hochwassersicherheit für die Stadt Salzburg bieten.Die Salzachbrücke ist das umfangreichste Brückenbauwerk zur Realisierung des S‐Bahn‐Projektes und überführt sowohl den Nahverkehr als auch den Personen‐ und Güterfernverkehr. Darüber hinaus ist sie ein wichtiger Baustein für den Ausbau des Eisenbahn‐Hochleistungskorridors Paris–Budapest. Bereits heute verkehren bis zu 300 Züge pro Tag in diesem Streckenabschnitt, weshalb eine sehr detaillierte Bauphasen‐ und sehr enge Terminplanung zu berücksichtigen war.Bernard Ingenieure schaffte in guter Zusammenarbeit mit allen am Bau Beteiligten für die ÖBB und die Stadt Salzburg den Spagat zwischen der Realisierung des architektonisch einzigartigen Brückenkonzeptes des Architekturbüros Halle 1, in dem es keine Regeldetails gibt, und den Grundlagen eines statisch‐konstruktiv hochwertigen Brückenbauwerkes.
The management of Cesarean scar ectopic pregnancy following treatment with methotrexate—a clinical challenge
Authors: Deb S. , Clewes J. , Hewer C. , Raine‐Fenning N. 
Published: October 2007

AbstractWe present a case of Cesarean scar ectopic pregnancy, complicated by the persistence of clinical symptoms despite a rapid and complete biochemical response to a single systemic injection of methotrexate. A 34‐year‐old woman with three previous Cesarean sections was diagnosed with a Cesarean scar ectopic pregnancy following @ in‐vitro fertilization treatment. The diagnosis was suggested by three‐dimensional (3D) ultrasound scan and confirmed with magnetic resonance imaging (MRI). Management involved administration of a single systemic injection of methotrexate and follow‐up with serial ultrasound assessments and serum beta‐human chorionic gonadotropin (β‐hCG) measurements. The main challenge was the persistence of clinical symptoms despite adequate medical treatment, as judged by complete resolution of biochemical trophoblastic activity, which resulted in repeated admissions to the hospital. Serial transvaginal ultrasound scans showed an initial increase in the size of the mass, which led to increasing anxiety in the couple. Eventually, 15 weeks after the administration of methotrexate, the couple requested surgical intervention. An uneventful surgical resection of the abnormal area, which showed appearances suggestive of trophoblastic tissue, was undertaken to good effect. In summary, despite a rapid normalization of serum β‐hCG following the administration of methotrexate, the patient remained symptomatic and had ultrasound appearances suggestive of incomplete resorption of trophoblast, necessitating surgical intervention. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Ultra‐precision Surface Finishing by Ion Beam Techniques
Authors: Hänsel T. , Frost F. , Nickel A. , Schindler T. 
Published: October 2007

AbstractIon beam etching based ultra precision surface finishing is a versatile technology with a high degree of predictability due to the high stability of state of the art ion sources and the acquired knowledge of the physics of beam surface interaction. The independent control of the ion energy and the ion current density over wide ranges and the possible additional use of chemical reactive species in combination with physical sputter removal allow solving tasks in a wide variety of applications. The paper summarizes the present status of more than 20 years of development of ion beam finishing technology in IOM. It gives an overview on the equipment and the components developed for production purposes and on the ion beam technologies developed to achieve nanometer and sub‐nanometer depth accuracies over the entire spectrum of spatial surface wavelength from the full aperture size down to the microroughness level of only micrometer lateral feature size. Results of the finishing of high‐end optical surfaces shown demonstrate the outstanding performances of the techniques with topography and roughness control on the atomic scale.
Einsatz von Vakuumpumpen bei der Herstellung von Photovoltaik‐Modulen
Authors: Kuhn Monika , Mossoloff Elke 
Published: October 2007

AbstractDurch den Einsatz von trocken verdichtenden Schraubenpumpen des Typs SCREWLINE SP 630/250 können die Betriebskosten an Kristallziehanlagen und an Laminatoren deutlich gesenkt werden. Die konstruktive Gestaltung der Getrieberaum‐Abdichtungen, der einfache Aufbau der Pumpe, der Service vor Ort und die Verwendung von Gasballast erlauben einen sehr zuverlässigen Betrieb und lange Wartungs‐ und Service‐Intervalle bei gleichzeitigem Verzicht von saugseitigen Staubabscheidern im Falle des Kristallziehens.
Is Preoperative Transarterial Chemoembolization Needed for a Resectable Hepatocellular Carcinoma?
Authors: Choi Gi‐Hong , Kim Dong‐Hyun , Kang Chang‐Moo , Kim Kyung‐Sik , Choi Jin‐Sub , Lee Woo‐Jung , Kim Byong‐Ro 
Published: October 2007

AbstractBackgroundWhether preoperative transarterial chemoembolization (TACE) has the therapeutic benefits in patients with resectable hepatocellular carcinoma (HCC) remains uncertain.Materials and methodsWe retrospectively investigated the influence of preoperative TACE on both disease‐free survival and the pattern of recurrence after curative resection. From March 1998 to January 2005, a series of 273 patients who underwent curative resection for HCC were reviewed. Altogether, 120 patients underwent preoperative TACE, and 153 patients did not. We compared disease‐free survival and the recurrence patterns between TACE and non‐TACE groups, as well as between subgroups, stratified with regard to initial tumor size (≤3 cm, 3–5 cm, >5 cm) and pathologic tumor stage (stage I‐II and stage III‐IVa). We also compared disease‐free survival and the pattern of recurrence among the three groups: complete necrosis, incomplete necrosis, non‐TACE groups.ResultsThe 1‐, 3‐, and 5‐year disease‐free survival rates were 76.0%, 57.7%, and 51.3%, respectively, in the TACE group and 70.9%, 53.8%, and 46.8%, respectively, in the non‐TACE group. No significant difference was observed in disease‐free survival or the pattern of recurrence between the TACE and non‐TACE groups. Further analysis of disease‐free survival and the pattern of recurrence between subgroups according to initial tumor size and tumor stage showed no significant differences. Complete necrosis of tumor was recognized in only 33 patients of the TACE group (p = 0.001). Among the three complete necrosis, incomplete necrosis, and non‐TACE groups, no significant difference was observed in disease‐free survival or the pattern of recurrence.ConclusionsPreoperative TACE did not significantly improve the disease‐free survival or the pattern of recurrence after curative resection of HCC. Even though this study is a retrospective analysis, preoperative TACE cannot be recommended as a routine procedure before hepatectomy for a resectable HCC.
Outcome After Hepatic Resection of Solitary Liver Metastasis from Colorectal Cancer in the Caudate Lobe
Authors: Saiura Akio , Yamamoto Junji , Koga Rintaro , Kokudo Norihiro , Seki Makoto , Oya Masatoshi , Ueno Masashi , Kuroyanagi Hiroya , Fujimoto Yoshiya , Natori Takeshi , Yamaguchi Toshiharu , Muto Tetsuichiro 
Published: October 2007

AbstractBackgroundThe prognosis of solitary liver metastasis involving the caudate lobe is unclear. This study analyzed the outcomes after resection of the caudate lobe for solitary colorectal liver metastasis.MethodsWe reviewed the records of 114 cases in which potentially curative hepatectomy were performed for solitary colorectal liver metastasis. Solitary liver metastasis involving the caudate lobe was seen in 14 cases (Caudate group). The outcomes were compared with those of the remaining 100 cases with metastasis in a site other than the caudate lobe (Other group).ResultsNo hospital deaths occurred. The 5‐year survival rate for all cases was 61%. Recurrence‐free and cumulative survivals were similar in the two groups, as were the intraoperative blood loss, duration of operation, and postoperative hospital stay. The distance of the surgical margin was significantly shorter in the Caudate group than in the Other group (0.6 mm vs. 6.6 mm; p = 0.001). A concomitant resection of the inferior vena cava was performed in four patients in the Caudate group but in no patients in the Other group (p < 0.001).ConclusionsDespite a minimal surgical margin, the resection of solitary colorectal liver metastasis offers favorable short‐ and long‐term outcomes comparable to those for colorectal liver metastasis at other sites.
Estradiol Favors the Formation of Eicosapentaenoic Acid (20:5n‐3) and n‐3 Docosapentaenoic Acid (22:5n‐3) from Alpha‐Linolenic Acid (18:3n‐3) in SH‐SY5Y Neuroblastoma Cells
Authors: Alessandri Jean‐Marc , Extier Audrey , Langelier Bénédicte , Perruchot Marie‐Hélène , Heberden Christine , Guesnet Philippe , Lavialle Monique 
Published: October 2007

AbstractWhether neurosteroids regulate the synthesis of long chain polyunsaturated fatty acids in brain cells is unknown. We examined the influence of 17‐β‐estradiol (E2) on the capacity of SH‐SY5Y cells supplemented with α‐linolenic acid (ALA), to produce eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). Cells were incubated for 24 or 72 h with ALA added alone or in combination with E2 (ALA + E2). Fatty acids were analyzed by gas chromatography of ethanolamine glycerophospholipids (EtnGpl) and phosphatidylcholine (PtdCho). Incubation for 24 h with ALA alone increased EPA and DPA in EtnGpl, by 330 and 430% compared to controls (P < 0.001) and DHA by only 10% (P < 0.05). Although DHA increased by 30% (P < 0.001) in ALA + E2‐treated cells, the difference between the ALA and ALA + E2 treatments were not significant after 24 h (Anova‐1, Fisher's test). After 72 h, EPA, DPA and DHA further increased in EtnGpl and PtdCho of cells supplemented with ALA or ALA + E2. Incubation for 72 h with ALA + E2 specifically increased EPA (+34% in EtnGpl, P < 0.001) and DPA (+15%, P < 0.001) compared to ALA alone. Thus, SH‐SY5Y cells produced membrane EPA, DPA and DHA from supplemental ALA. The formation of DHA was limited, even in the presence of E2. E2 significantly favored EPA and DPA production in cells grown for 72 h. Enhanced synthesis of ALA‐elongation products in neuroblastoma cells treated with E2 supports the hypothesis that neurosteroids could modulate the metabolism of PUFA.