bluuebunny/crossref_metadata_2025_split huggingface dataset:
Korrosionsuntersuchungen an mittels PVD mit Zn und Zn/Mn beschichteten Stählen
Authors: Wolf G. K. , Münz R. 
Published: February 2006

AbstractAlternativ zur Schmelztauch‐ bzw. elektrogalvanischen Verzinkung von Stählen bieten sich Gasphasenabscheidungen (PVD) wegen ihrer Flexibilität bezüglich Legierungszusammensetzung und Umweltverträglichkeit an. Dabei muss ein PVD‐beschichteter Stahl mindestens die gleiche Korrosionsbeständigkeit besitzen wie die mit „klassischen”︁ Abscheideverfahren vergüteten Stähle.Daher wurde für die Methode Elektronenstrahlaufdampfen auf niedrig legierte Stähle die Korrosionsresistenz von Zink‐ und Zink/Manganschichten, die z. T. ohne und z. T. mit Ionenstrahlunterstützung abgeschieden wurden, geprüft. Die Untersuchungen wurden mittels Salzsprühtest und elektrochemischen Potential/Zeitmessungen durchgeführt. Zunächst wurde die chemische und bestrahlungstechnische Vorbehandlung der Substrate und der Einfluss des Ionenbeschusses auf das Korrosionsschutzvermögen der Schichten unter die Lupe genommen. Dann wurde der Einfluss der Zinkschichtdicke im Vergleich mit einer 8μm dicken elektrogalvanischen Referenzzschicht beleuchtet. Schließlich wurden Zn/Mn‐Legierungen, Zn/Mn‐Multilagen und Zn‐Schichten mit Mn‐ oder Zn/Mn‐Deckschicht (Toplagen) untersucht.Durch eine optimierte Vorbehandlung und Ionenunterstützung erhält man PVD‐Zinkschichten mit, unter Berücksichtigung der Schichtdicke, mit der Referenzschicht vergleichbarer Korrosionsresistenz. Als beste Mn‐haltige Schichten erwiesen sich die Toplagen, welche das Korrosionsschutzvermögen der Referenzschicht deutlich übertreffen.Daneben wurde noch festgestellt, dass Potential/Zeitmessungen mit den Ergebnissen des Salzsprühtests in der Tendenz gut übereinstimmen.
Untersuchungen zur Wälzermüdung nach induktivem Kurzzeitanlassen
Authors: Scheerer H. , Berger C. 
Published: February 2006

AbstractInduktiv randschichtgehärtete Komponenten werden zur Verbesserung der Bauteilzähigkeit, der Bearbeitbarkeit und zur Vermeidung von Verzug unter Betriebsbedingungen in den meisten Fällen zusätzlich im Ofen angelassen. In der Regel wird angelassen, wenn noch geschliffen werden soll. Entsprechend den Anlassbedingungen ändern sich der nach dem Härten vorliegende Gefügezustand und damit auch die Werkstofffestigkeit. Die hier durchgeführten Untersuchungen sollen zeigen, ob und bei welchen Temperaturen das bisherige Ofenanlassen durch induktives Kurzzeitanlassen ersetzt werden kann und wie sich diese Wärmebehandlung auf die Wälzermüdungseigenschaften auswirkt. Es konnte gezeigt werden, dass bei optimierten Kurzzeitanlassparametern Werkstoffzustände erreicht werden, welche sich bei Wälzbeanspruchung günstiger verhielten als Proben, welche im Ofen oder gar nicht angelassen wurden. Damit öffnet sich für zahlreiche Anwendungen die Möglichkeit, das bisherige Anlassen im Ofen durch das schnellere und kostengünstigere induktive Kurzzeitanlassen nach induktivem Randschichthärten zu ersetzen.
Enhanced γ‐glutamylcysteine synthetase activity decreases drug‐induced oxidative stress levels and cytotoxicity
Authors: Das Gokul C. , Bacsi Attila , Shrivastav Meena , Hazra Tapas K. , Boldogh Istvan 
Published: February 2006

AbstractMultidrug resistance of cancer cells can be intrinsic or acquired and occurs due to various reasons, including increased repair of genotoxic damage, an enhanced ability to remove/detoxify chemical agents, or reactive oxygen species (ROS), and repression of apoptosis. Human A2780/100 ovarian carcinoma cells exhibit resistance to DNA cross‐linking agents, chlorambucil (Cbl), cisplatin (Cpl), melphalan (Mel), and ionizing radiation (IR) compared to the parental cell line, A2780. In the present study, we show that when A2780/100 and A2780 cells were treated with Cbl, GSH was extruded via methionine or cystathionine‐inhibitable transporters of intact plasma membrane. GSH loss was followed by a rapid increase in ROS levels. The resistant, but not drug‐sensitive cells normalized the intracellular GSH concentration along with ROS levels within 4–6 h after Cbl addition, and survived drug treatment. Normalization of GSH and ROS levels in A2780/100 cells correlated well with elevated γ‐glutamylcysteine synthetase (γ‐GCS) activity (10 ± 1.8‐fold over A2780 cells). Ectopic overexpression of the γ‐GCS heavy subunit in drug‐sensitive cells nearly restored GSH and ROS to pre‐treatment levels consequently increased cellular resistance to genotoxic agents (Cbl, Cpl, and IR), while overexpression of γ‐GCS light subunit had no such effects. Thus, in our model system, drug‐resistant cells have the inherent ability to maintain increased γ‐GCS activity, reestablish physiological GSH, and cellular redox state and maintain increased cellular resistance to DNA cross‐linking agents and IR. © 2006 Wiley‐Liss, Inc.
Approximation algorithms for minimizing total weighted completion time of orders on identical machines in parallel
Authors: Leung Joseph Y‐T. , Li Haibing , Pinedo Michael 
Published: February 2006

AbstractWe consider the problem of scheduling orders on identical machines in parallel. Each order consists of one or more individual jobs. A job that belongs to an order can be processed by any one of the machines. Multiple machines can process the jobs of an order concurrently. No setup is required if a machine switches over from one job to another. Each order is released at time zero and has a positive weight. Preemptions are not allowed. The completion time of an order is the time at which all jobs of that order have been completed. The objective is to minimize the total weighted completion time of the orders. The problem is NP‐hard for any fixed number (≥2) of machines. Because of this, we focus our attention on two classes of heuristics, which we refer to as sequential two‐phase heuristics and dynamic two‐phase heuristics. We perform a worst case analysis as well as an empirical analysis of nine heuristics. Our analyses enable us to rank these heuristics according to their effectiveness, taking solution quality as well as running time into account. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Frequency of knowledge of results and motor learning in persons with developmental delay
Authors: Rice Martin S , Hernandez Holly G 
Published: February 2006

AbstractThe purpose of this study was to investigate the effect of high versus low frequency knowledge of results (KR) in a group of 16 individuals with developmental delay and in gender and age‐matched average individuals learning a motor skill on a laptop computer. Participants were randomly assigned to either a 100% KR or a 50% KR group. KR was provided during the acquisition phase according to group assignment as participants learned the motor skill, whereas no KR was provided during the retention phase. Results indicated both populations who received 50% KR in the acquisition phase demonstrated better performance in the retention phase than those who received 100% KR. The results of this study suggest that, as has been found in the average population, feedback that is too frequent can interfere with learning and retention of tasks for individuals with developmental disabilities (DD). Limitations involved the small sample size along with the task potentially being artificial in nature. Future research is needed to study further the effects of frequency of KR on skill acquisition, particularly in instrumental activities of daily living in this population. Copyright © 2006 John Wiley & Sons, Ltd
Die Geschichte der Alkylanzien: “Die klinische Prüfung ist das entscheidende Terrain”
Authors: Meyer Ulrich 
Published: February 2006

AbstractDeutschland – onkologische “Apotheke der Welt”? In der “Deutschen Medizinischen Wochenschrift” zogen der Präsident der Deutschen Krebsgesellschaft und der Direktor eines US‐amerikanischen Pharmaunternehmens 1999 eine tendenziell ernüchternde Bilanz der “Arzneimittelentwicklung in der Onkologie ... unter besonderer Berücksichtigung des Standorts Deutschland.”
Tumorhemmende Metallverbindungen: Entwicklung, Bedeutung und Perspektiven
Authors: Galanski Mathea Sophia , Keppler Bernhard K. 
Published: February 2006

AbstractDie weltweit in der Klinik etablierten tumorhemmenden Metallverbindungen Cisplatin, Carboplatin und Oxaliplatin werden erfolgreich vor allem in der Kombinationschemotherapie mit etablierten rein organischen Tumortherapeutika eingesetzt. Die besten Ergebnisse werden mit Cisplatin am Hodentumor mit Heilungsraten um 90 % erzielt. Leider ist das Wirkungsspektrum der vorangenannten Platinkomplexe beschränkt, und es kommt mitunter zu sehr erheblichen Nebenwirkungen. Die Ausweitung des Indikationsspektrums sowie eine Verringerung der systemischen Toxizität scheint mit der Entwicklung neuer Metallkoordinationsverbindungen möglich, die Ruthenium oder Gallium als Zentralion enthalten. Die Ergebnisse aus zwei Phase‐I‐Studien stimmen hoffnungsvoll.
Nutzen von Lipidsenkern im Rahmen der Sekundärprävention
Authors: Weizel Achim 
Published: February 2006

AbstractStellungnahme der Deutschen Gesellschaft zur Bekämpfung von Fettstoffwechselstörungen und ihren Folgeerkrankungen DGFF (Lipid‐Liga) e. V.Mit der Diskussion neuerer Studienergebnisse zum Stellenwert der Statine in der Sekundärprävention ist eine gewisse Verunsicherung der Ärzteschaft und auch der Patienten trotz des erwiesenen Nutzens einer konsequenten LDL‐Cholesterinsenkung im Hinblick auf die Mortalität und Morbidität der koronaren Herzkrankheit eingetreten.
Inhibition von Virulenzfaktoren: Ein neuer Ansatz zur Entwicklung von Antibiotika
Authors: Holzgrabe Ulrike 
Published: February 2006

AbstractDie Entwicklung neuer Antibiotika hinkt immer mehr hinter der Entwicklung von Resistenzen gegen Antibiotika zurück. Somit wird es zunehmend dringlicher, Antibiotika mit neuen Wirkmechanismen zu entwickeln.
Risk estimates for uniparental disomy following prenatal detection of a nonhomologous Robertsonian translocation
Authors: Shaffer Lisa G. 
Published: February 2006

AbstractCarriers of nonhomologous Robertsonian translocations (ROB) are at risk for having offspring with uniparental disomy (UPD). Although risk estimates have been calculated in several independent studies, the estimates have not been optimal because most studies are not of sufficient size and UPD events are rare. However, these collective data have provided the opportunity to derive an overall risk estimate for UPD in the fetus after the prenatal identification of a ROB. Copyright © 2006 John Wiley & Sons, Ltd.
The relation between fetal nasal bone length and biparietal diameter in the Korean population
Authors: Shin Joong Sik , Yang Jae Hyug , Chung Jin Hoon , Kim Moon Young , Ryu Hyun Mee , Han Jung Yeol , Choi June Seek 
Published: February 2006

AbstractObjectiveTo evaluate the relation between fetal nasal bone length (NBL) and biparietal diameter (BPD) at 15–19.9 (20) weeks of gestation by ultrasonography in the Korean population.MethodsThe study population included 1268 Korean women (aged between 19 and 45 years) with a singleton pregnancy who registered at the Maternal Fetal Medicine Unit of Samsung Cheil Hospital between September 2003 and February 2005. Ultrasound measurements of NBL were performed using a strict sagittal plan of the fetal head. Other fetal biometry profiles were conducted before amniocentesis for fetal karyotyping.ResultsNBL and fetal biometry profiles were measured successfully in 77.9% (988/1268) of the fetuses. NBL was found to increase linearly as a function of BPD (P < 0.001) with a median NBL of 4.4 mm (range 1.9–7.9). NBL increases through 15–19.9 (20) weeks of gestation were given by the equation NBL (mm) = 0.0836 × BPD (mm) + 1.368 (R2 = 0.1, P < 0.001).ConclusionsFetal NBL and BPD are linearly related in the second trimester. Fetal NBL in the Korean population is likely to be shorter than that reported for Caucasians and African‐Americans. Copyright © 2006 John Wiley & Sons, Ltd.
Unusual sonographic features of ARPKD
Authors: Okumura Maria , Bunduki Victor , Shiang Christina , Schultz Regina , Zugaib Marcelo 
Published: February 2006

AbstractThe classic sonographic appearance of the kidneys in fetuses with autosomal recessive polycystic kidney disease (ARPKD) has been well described. We report a case of enlarged kidneys with pyramidal hyperechogenicity quite similar to medullary nephrocalcinosis found in a fetus at 34 weeks' gestation. At 39 weeks, a female neonate was delivered and died after 22 h due to pulmonary insufficiency secondary to severe oligohydramnios. On pathological analysis, the gross and microscopic findings were typical of ARPKD with diffuse dilatation of tubules throughout. The fetal renal lobulation was prominent and on section, the pyramids were delineated within each lobule, accounting for the clear image of the pyramids observed on sonography. Copyright © 2006 John Wiley & Sons, Ltd.
Detecting sex chromosome anomalies and common triploidies in products of conception by array‐based comparative genomic hybridization
Authors: Ballif Blake C. , Kashork Catherine D. , Saleki Reza , Rorem Emily , Sundin Kyle , Bejjani Bassem A. , Shaffer Lisa G. 
Published: February 2006

AbstractObjectivesIn recent years, array‐based comparative genomic hybridization (array CGH) has moved to the forefront of molecular cytogenetics with its ability to rapidly characterize chromosome abnormalities at resolutions much higher than routine chromosome banding. However, array CGH, like all CGH procedures, has heretofore been deemed unable to detect ploidy, a major cause of fetal demise and spontaneous miscarriage.MethodWe recently developed a CGH microarray that is designed for detecting aneuploidy and unbalanced chromosome rearrangements. Here, we introduce the use of a Klinefelter male cell line (47,XXY) as a control for array CGH analyses on products of conception (POCs).ResultsThis approach facilitates the detection of common trisomies and monosomies of the sex chromosomes by reducing the analysis to the identification of single copy gains or losses. Furthermore, in a blinded study, careful interpretation of the microarray results with particular attention to the sex chromosome ratios between the patient sample and the control allowed for the detection of some common triploidies.ConclusionThese results suggest that using a chromosomally abnormal cell line in array CGH analysis can be applied to other CGH platforms and that array CGH, when properly performed and analyzed, is a powerful tool that can detect most chromosomal abnormalities observed in a clinical setting including some polyploidies. Copyright © 2006 John Wiley & Sons, Ltd.
Modification of immobilized metal complexes toward the design and synthesis of functional materials for nitric oxide delivery
Authors: Mitchell‐Koch Jeremy T. , Padden Karen M. , Borovik A. S. 
Published: February 2006

AbstractFunctional polymeric materials containing immobilized metal complexes with the potential to bind nitric oxide (NO) are described. The materials were synthesized using template copolymerization techniques and contain immobilized metalloporphyrin and metallosalen (N,N′‐bis(salicylidene)‐1,2‐ethylenediaminato(2‐)) sites where NO binding occurs. A potential drawback of current materials designed for NO‐delivery is the rebinding of NO to the material after release. To minimize this undesirable rebinding event, materials were prepared in which immobilized sites contain additional covalently‐linked functional groups that can bind to the metal centers after NO dissociation. A model system with a covalently attached CoIIsalen complex and pyridine groups confirmed that the immobilized sites bind NO in the presence of the additional ligands. Attempts to immobilize an iron porphyrin, containing two axial imidazole ligands, were unsuccessful because the lability of the iron center prevented the formation of a stable template. Instead, the desired material was achieved by selecting CoIII porphyrin with axially coordinated imidazole ligands as the template complex. Once immobilized, a procedure was developed to remove the cobalt ions and incorporate iron into the sites. The site structure of these new immobilized sites was examined spectroscopically. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2282–2292, 2006
Synthesis and characterization of new aromatic polyamides bearing crown ethers or their dipodal counterparts in the pendant structure. I. Benzo‐12‐crown‐4 and ortho‐bis(2‐ethoxyethoxy)benzene
Authors: Calderón Verónica , García Félix C. , De La Peña José L. , Maya Eva M. , García José M. 
Published: February 2006

AbstractTwo novel isophthalic diacid‐based monomers have been synthesized by inclusion in ring position 5 of a functionalized benzoylamine moiety. The functionalization includes a 12‐crown‐4 ether group fused with the benzene subunit and a dipodand substructure, formally a disubstitution of the benzene ring, with two sequences of ethyl‐terminated ethylene oxide units, which represent the open‐chain counterpart of the alicylic crown moiety. The polycondensation of the two diacids with five aromatic diamines yielded 10 new polyamides with crown or podand pendant substructures. The polyamides had previously been chemically characterized by NMR, IR, and elemental analysis. The polymers showed high glass transition temperatures of up to 349 °C, good thermal stability (Tdonset, N2 ≈ 400 °C), and improved solubility in organic solvents. The presence of acyclic or alicyclic oxyethylene sequences as crown ether or podand substructures and an additional amide side group per repeat unit made the polymers essentially amorphous and improved their water absorption ability in comparison with nonsubstituted polyamides. Water uptake values as high as 12% were observed at 65% relative humidity. All the polyamides showed a good film‐forming ability, and the mechanical properties of these films are considered to be satisfactory for experimental aromatic polyamides. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2270–2281, 2006
The influence of surfactant coverage of the minidroplets on RAFT miniemulsion polymerization
Authors: Yang Lei , Luo Yingwu , Li Bogeng 
Published: February 2006

AbstractThe surfactant coverage of minidroplets was tuned by postaddition of more surfactants after preparation of the miniemulsion of styrene. The influence of surfactant coverage on reversible addition‐fragmentation chain transfer (RAFT) miniemulsion polymerization of styrene was investigated. When the surfactant (sodium dodecyl sulfate; SDS) coverage was as low as 40%, two kinds of particles, denoted as polymer and oligomer particles, were formed in the early stage of the polymerization. Polymer chains within two kinds of particles grew in a parallel way during the rest period of the polymerization. The oligomer particles contributed less than 10% to the final monomer conversion but consumed over one in third the original RAFT agent molecules. Oligomer particles were larger in size but much lower in molecular weight. Both the particle size and molecular weight distributions were bimodal. With increase of SDS coverage, the formation of oligomer particles was suppressed. As a result, the nucleation efficiency of the minidroplets was greatly enhanced and the molecular weight and particle size distributions were dramatically narrowed. The formation of the oligomer particles was ascribed to the superswelling occurring in the beginning stage of the polymerization. The experimental observations are in excellent accord to the superswelling theory. Postaddition of surfactant presents a novel method to narrow particle size and molecular weight distributions in RAFT miniemulsion polymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2293–2306, 2006
Novel polyamidoamine‐based hydrogel with an innovative molecular architecture as a Co2+‐, Ni2+‐, and Cu2+‐sorbing material: Cyclovoltammetry and extended X‐ray absorption fine structure studies
Authors: Ferruti Paolo , Ranucci Elisabetta , Bianchi Sabrina , Falciola Luigi , Mussini Patrizia R. , Rossi Manuela 
Published: February 2006

AbstractAn amphoteric polyamidoamine (PAA)‐based hydrogel, named INT‐PAA1, with a novel molecular architecture was prepared and studied as a Co2+‐, Ni2+‐, and Cu2+‐sorbing material. This hydrogel was obtained by the synthesis of a PAA in the presence of a second presynthesized PAA carrying many primary amino groups as side substituents, which acted as a macromolecular crosslinking agent. Therefore, it had an intersegmented structure. INT‐PAA1 exhibited a remarkable sorption capacity and sorption rate for Co2+, Ni2+, and Cu2+ that were advantageously in situ monitored by cyclic voltammetry. An extended X‐ray absorption fine structure spectroscopy characterization of the Co2+/INT‐PAA1 complex was also performed. The very fast and quantitative metal‐ion uptake, made apparent by an intense coloring of the hydrogel, showed remarkable potential for environmental applications such as heavy‐metal detection, recovery, and elimination. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2316–2327, 2006
Terpyridine‐substituted, fluorescent polymers and their chelation with zinc ion: The ligand‐to‐metal ratio and optical properties
Authors: Chu Qinghui , Pang Yi 
Published: February 2006

AbstractSoluble, fluorescent, terpyridine‐substituted, conjugated polymers were prepared and characterized. The polymer chains included a defined oligo(phenylenevinylene) fragment, on which the terpyridine‐functional group was attached. The polymers were blue‐fluorescent with emission peaks at 400–427 nm in tetrahydrofuran solutions. Upon chelation with the Zn(II) cation, the emission maxima were shifted to a longer wavelength by as much as 113 to 506–526 nm. A model compound was also prepared to aid the structural characterization. The ratio of terpyridine to Zn2+ in the polymer complex was found to be 1:1 on the basis of spectroscopic evidence, which included mass spectrometry, 1H NMR, and Job titration. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2338–2345, 2006
Optical‐limiting and nonlinear optical polyacetylenes: Synthesis of azobenzene‐containing poly(1‐alkyne)s with different spacer and tail lengths
Authors: Yin Shouchun , Xu Hongyao , Su Xinyan , Li Gang , Song Yinlin , Lam Jackywingyip , Tang Benzhong 
Published: February 2006

AbstractPoly(1‐alkyne)s containing azobenzene pendant groups with different lengths of the spacer and terminal alkyloxy group {[HCC(CH2)mOCOC6H4NNC6H4OCpH2p+1]n, where m = 1, 2, 3, or 9 and p = 4, 7, or 12} were synthesized in satisfactory yields with the [Rh(nbd)Cl]2–Et3N catalyst. All the polymers were soluble in common organic solvents such as CHCl3 and tetrahydrofuran. Their structures and properties were characterized and evaluated with IR, NMR, thermogravimetric analysis, UV, and optical‐limiting and nonlinear optical analyses. All the polymers were thermally stable and decomposed at temperatures as high as ∼300 °C. The optical‐limiting and nonlinear optical properties of the polymers were sensitive to their molecular structures. Polymers having shorter spacer lengths and longer terminal groups showed better performances and larger third‐order nonlinear optical susceptibility (up to 1.34 × 10−10 esu). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2346–2357, 2006