bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying rate enhancements for acid catalysis in CO2‐enriched high‐temperature water
Authors: Hunter Shawn E. , Savage Phillip E. 
Published: December 2007

AbstractThermodynamic calculations revealed that 10 to 100‐fold increases in reaction rate are obtainable with added CO2 (0.1–1 MPa) for an acid‐catalyzed reaction in high‐temperature liquid water (HTW) that is first order in H+ concentration. These calculations suggest that CO2 is most effective as a rate‐enhancing additive in HTW at lower temperatures (150–200°C). When compared with increased temperature as a competitive option for accelerating acid‐catalyzed reactions in HTW, CO2 addition generally carries a lower pressure penalty (and no temperature penalty) for the model acid‐catalyzed reaction with activation energies of up to 35 kcal/mol. An experimental survey revealed that CO2 addition is effective for achieving increased reaction rates for dibenzyl ether hydrolysis in HTW, but that bisphenol A cleavage, methyl benzoate hydrolysis, and o‐phthalic acid decarboxylation were not significantly impacted by added CO2. This behavior is consistent with previous results for these reactions wherein mineral acid, rather than CO2, was added to lower the pH. A summary of experimental results reported for reactions in CO2‐enriched HTW revealed that product yields of some reactions can be increased by a factor of 23 with added CO2. Taken collectively, these results suggest that CO2 addition may be a practical technique for making HTW more attractive as a reaction medium for acid‐catalyzed organic synthesis. © 2007 American Institute of Chemical Engineers AIChE J, 2008
A comparison of salivary pH in sympatric wild lemurs (Lemur catta and Propithecus verreauxi) at Beza Mahafaly Special Reserve, Madagascar
Authors: Cuozzo Frank P. , Sauther Michelle L. , Yamashita Nayuta , Lawler Richard R. , Brockman Diane K. , Godfrey Laurie R. , Gould Lisa , Youssouf Ibrahim Antho Jacky , Lent Cheryl , Ratsirarson Joelisoa , Richard Alison F. , Scott Jessica R. , Sussman Robert W. , Villers Lynne M. , Weber Martha A. , Willis George 
Published: December 2007

AbstractChemical deterioration of teeth is common among modern humans, and has been suggested for some extinct primates. Dental erosion caused by acidic foods may also obscure microwear signals of mechanical food properties. Ring‐tailed lemurs at the Beza Mahafaly Special Reserve (BMSR), Madagascar, display frequent severe tooth wear and subsequent tooth loss. In contrast, sympatric Verreaux's sifaka display far less tooth wear and infrequent tooth loss, despite both species regularly consuming acidic tamarind fruit. We investigated the potential impact of dietary acidity on tooth wear, collecting data on salivary pH from both species, as well as salivary pH from ring‐tailed lemurs at Tsimanampesotse National Park, Madagascar. We also collected salivary pH data from ring‐tailed lemurs at the Indianapolis Zoo, none of which had eaten for at least 12 hr before data collection. Mean salivary pH for the BMSR ring‐tailed lemurs (8.098, n=41, SD=0.550) was significantly more alkaline than Verreaux's sifaka (7.481, n=26, SD=0.458). The mean salivary pH of BMSR (8.098) and Tsimanampesotse (8.080, n=25, SD=0.746) ring‐tailed lemurs did not differ significantly. Salivary pH for the Indianapolis Zoo sample (8.125, n=16, SD=0.289) did not differ significantly from either the BMSR or Tsimanampesotse ring‐tailed lemurs, but was significantly more alkaline than the BMSR Verreaux's sifaka sample. Regardless of the time between feeding and collection of pH data (from several minutes to nearly 1 hr), salivary pH for each wild lemur was above the “critical” pH of 5.5, below which enamel demineralization occurs. Thus, the high pH of lemur saliva suggests a strong buffering capacity, indicating the impact of acidic foods on dental wear is short‐lived, likely having a limited effect. However, tannins in tamarind fruit may increase friction between teeth, thereby increasing attrition and wear in lemurs. These data also suggest that salivary pH varies between lemur species, corresponding to broad dietary categories. Am. J. Primatol. 70:363–371, 2008. © 2007 Wiley‐Liss, Inc.
Anorganische Nanopartikel zum Transport von Nucleinsäuren in Zellen
Authors: Sokolova Viktoriya , Epple Matthias 
Published: December 2007

AbstractDie Aufnahme von Nucleinsäuren (DNA oder RNA) in lebende Zellen wird als Transfektion bezeichnet. Diese wichtige Technik der modernen Biochemie und Molekularbiologie ermöglicht durch die Einschleusung von genetischem Material sowohl die Hochregulierung der Produktion bestimmter Proteine als auch die gezielte Inhibition der Proteinsynthese (Gen‐Stummschaltung). Da Nucleinsäuren die Zellwand nicht allein durchdringen können, bedarf es geeigneter Träger. Neben viralen, polymeren und liposomalen Trägern sind anorganische Nanopartikel für diese Aufgabe besonders geeignet, da sie in vielfältiger Natur hergestellt und oberflächenfunktionalisiert werden können. In diesem Aufsatz wird der gegenwärtige Stand der Forschung aus chemischer Sicht vorgestellt; Vor‐ und Nachteile der verfügbaren Methoden werden diskutiert.
Alternative experimental approaches for interpreting skeletal findings in safety studies
Authors: Augustine‐Rauch Karen 
Published: December 2007

AbstractStandard evaluations for characterizing selective developmental toxicity are traditionally undertaken in vivo. These studies incur significant cost in animal use, labor and compound, ultimately limiting the selection of compounds that can be evaluated in vivo. Such limitations hinder the ability to address questions regarding whether teratogenic outcome was caused by intended pharmacology or attributed to off‐target effects associated with the structure of the small molecule. Ascertaining a better understanding of the published literature can enhance interpretation of existing in vivo datasets and hypotheses regarding critical windows of sensitivity and underlying mechanisms of teratogenicity. Thoughtful execution of investigative in vivo and in vitro studies can test and further define the underlying mechanism of teratogenicity. Skeletal variations and malformations are frequently encountered in in vivo studies and can be difficult to interpret in context of defining hazard assessment and mechanisms of abnormal development. This commentary reviews how investigative approaches can be integrated to better understand teratogenic mechanism as it pertains compounds that produce skeletal abnormalities. Approaches are discussed in context of how they could be used to study a compound that has been found to produce fused and wavy ribs in rat fetuses. An investigative approach is described that utilizes three strategies: 1) maximizing the data available from in vivo studies; 2) performing critical window studies in vivo; and 3) performing mechanism of action evaluations using gene expression studies and developmental model systems. Birth Defects Res (Part B), 80:497–504, 2007. © 2007 Wiley‐Liss, Inc.
Altered axial skeletal development
Authors: Tyl Rochelle W. , Chernoff Neil , Rogers John M. 
Published: December 2007

AbstractThe axial skeleton is routinely examined in standard developmental toxicity bioassays and has proven to be sensitive to a wide variety of chemical agents. Dysmorphogenesis in the skull, vertebral column and ribs has been described in both human populations and in laboratory animals used to assess potential adverse developmental effects. This article emphasizes vertebrae and rib anomalies both spontaneous and agent induced. Topics discussed include the morphology of the more common effects; incidences in both human and experimental animal populations; the types of anomalies induced in the axial skeleton by methanol, boric acid, valproic acid and others; the postnatal persistence of common skeletal anomalies; and the genetic control of the development of the axial skeleton. Tables of the spontaneous incidence of axial anomalies in both humans and animals are provided. Birth Defects Res (Part B) 80:451–472, 2007. Published 2007 Wiley‐Liss, Inc.
Zum Tragverhalten von Slim‐Floor‐Konstruktionen
Authors: Hegger Josef , Kerkeni Naceur , Roggendorf Thomas 
Published: December 2007

AbstractSind Spannbeton‐Fertigdecken auf schlanken Unterzügen aufgelagert, wird die Querkrafttragfähigkeit der Platten durch Beanspruchungen in Querrichtung herabgesetzt. Bisher existiert kein einheitliches Bemessungskonzept, das die verbleibende Tragfähigkeit zutreffend ermittelt. Dieser Beitrag beschreibt Großversuche zum Tragverhalten von so genannten Slim‐Floor‐Konstruktionen, bei denen vorgespannte Hohlplatten auf deckengleichen Stahlträgern aufgelagert sind. Es werden Empfehlungen zur Bemessung und Konstruktion bei biegeweicher Lagerung abgeleitet.
Sicherheitsanalyse des Naturzugkühlturms KW Ibbenbüren Block B
Authors: Dorge Axel , Eckstein Ulrich , Wörmann Ralf 
Published: December 2007

AbstractBauwerke deteriorieren während ihrer Lebenszeit, d. h. sie verlieren ihre Ursprungsqualität. Zusätzlich altern sie virtuell durch laufende Modernisierung ihrer Regelwerke, welche Erkenntnisse der Wissenschaft zum Stand der Technik erheben. Das gilt besonders für Naturzugkühltürme, jene den Atmosphärilien extrem ausgesetzten Kraftwerkskomponenten, ohne die in thermischen Kraftwerken keine wirtschaftliche Erzeugung elektrischer Energie möglich ist. Der vorliegende Beitrag skizziert die Sicherheitsüberprüfung eines ca. 25 Jahre alten Kühlturms, der für seine Restlebensdauer von ca. weiteren 20 Jahren frei von Sicherheitsrisiken sein muss, obwohl sich maßgebende Normen, gewonnenes Tragwerkswissen und Abbaupläne der DSK seit seiner Indienststellung merkbar verändert haben.
Schlanke Hochbaudecken. Steifigkeitsorientierte Analyse zur Klärung extremer Durchbiegungen
Authors: Noakowski Piotr , Leszinski Holger , Breddermann Martin , Rost Markus 
Published: December 2007

AbstractDie Gebrauchstauglichkeit eines großen Bürogebäudes wurde durch erhebliche Durchbiegungen der schlanken Flachdecken gemindert. Das seit der Deckenerstellung auffällige Verformungsverhalten hat Schäden an Trennwänden und Fassaden verursacht und stellt die Tragfähigkeit der Konstruktion in Frage. Der Beitrag beschreibt die festgestellten Mängel und den steifigkeitsorientierten Prozess zur Klärung ihrer Ursachen und Bewertung der Konsequenzen.
Modeling based on subspace orthogonal projections for QSAR and QSPR research
Authors: Liang Yizeng , Yuan Dalin , Xu Qingsong , Kvalheim Olav Martin 
Published: December 2007

AbstractA novel projection modeling method for quantitative structure activity relationship (QSAR) and quantitative structure property relationship (QSPR) is developed in this paper. Orthogonalization of block variables is introduced to deal with the problem of variable selection. Projections based on least squares are used to construct the modeling space in order to search for the best regression directions for chemical modeling. A suitable prediction space for such a model is further defined to confine the usage range of the model. Three real data sets were analyzed to check the performance of the proposed modeling method. The results obtained from Monte‐Carlo cross‐validation (MCCV) showed that the proposed modeling method might provide better results for QSAR and QSPR modeling than PCR and PLS with respect to both fitting and prediction abilities. Copyright © 2007 John Wiley & Sons, Ltd.
A neural network approach based on gold‐nanoparticle enzyme biosensor
Authors: Torrecilla José S. , Mena Maria L. , Yáñez‐Sedeño Paloma , García Julián 
Published: December 2007

AbstractGold nanoparticles have demonstrated to be a very useful material for the construction of stable and sensitive glucose oxidase (GOx) amperometric biosensors. However, as for other enzyme electrodes, the lack of specificity for glucose limits their practical applications. Coupling biosensor responses with chemometric tools can be used to solve complex analytical signals from mixtures of species with similar properties. In this work, an amperometric biosensor based on a colloidal gold—cysteamine—gold disk electrode with the enzyme GOx and a redox mediator, tetrathiafulvalene (TTF), co‐immobilised atop the modified electrode, was used for the simultaneous determination of glucose and its common interferences, ascorbic acid and uric acid, in mixtures. Analytical data obtained from cyclic voltammograms generated with the biosensor were processed using an artificial neural network (ANN), and the separate quantification of the analytes over a range of 0.1–1 mM each was performed without any pretreatment. In all cases, the correlation coefficients obtained were higher than 0.99 and the mean prediction error was less than 1.7%. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative iterative target transformation factor analysis
Authors: Richards Selena E. , Walmsley Anthony D. 
Published: December 2007

AbstractTraditionally, improvement of the constrained alternating least squares (ALS) solution has been executed by the addition of a priori information in the initial estimates and or constraints. However, there are cases where this information simply does not exist or is impossible to acquire under the process conditions. Therefore, new strategies are required to produce starting estimates close to the actual solution without the need of a priori information. Quantitative iterative target transformation factor analysis (QITTFA) is developed as a solution to this problem. The QITTFA approach combines the strengths of both iterative target transformation factor analysis (ITTFA) and simple‐to‐use interactive self‐modelling mixture analysis (SIMPLISMA) to (1) produce a solution space spanned by the independent factors such that the variance contribution due to noise is reduced, (2) to iteratively refine the solutions space prior to ALS and (3) to select the most pure variables from the refined solution space using the purity criterion. It has been observed that the QITTFA approach markedly improves the conventional SIMPLISMA and second derivative SIMPLISMA performance in the presence and absence of selectivity. In addition, components of differing spectral characteristics (narrow or broad spectral features) can be resolved, without a priori knowledge of the shapes of the pure components. This has been demonstrated with a simulated high performance liquid chromatography‐diode array detection (HPLC‐DAD) dataset, a laboratory‐based UV–Vis calibration dataset and a gaseous near infrared (NIR) dataset from an industrial process. Copyright © 2007 John Wiley & Sons, Ltd.
Using Unfold‐PCA for batch‐to‐batch start‐up process understanding and steady‐state identification in a sequencing batch reactor
Authors: Aguado D. , Ferrer A. , Seco A. , Ferrer J. 
Published: December 2007

AbstractIn chemical and biochemical processes, steady‐state models are widely used for process assessment, control and optimisation. In these models, parameter adjustment requires data collected under nearly steady‐state conditions. Several approaches have been developed for steady‐state identification (SSID) in continuous processes, but no attempt has been made to adapt them to the singularities of batch processes. The main aim of this paper is to propose an automated method based on batch‐wise unfolding of the three‐way batch process data followed by a principal component analysis (Unfold‐PCA) in combination with the methodology of Brown and Rhinehart 2 for SSID. A second goal of this paper is to illustrate how by using Unfold‐PCA, process understanding can be gained from the batch‐to‐batch start‐ups and transitions data analysis. The potential of the proposed methodology is illustrated using historical data from a laboratory‐scale sequencing batch reactor (SBR) operated for enhanced biological phosphorus removal (EBPR). The results demonstrate that the proposed approach can be efficiently used to detect when the batches reach the steady‐state condition, to interpret the overall batch‐to‐batch process evolution and also to isolate the causes of changes between batches using contribution plots. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis, Biological Evaluation, and Molecular Modeling Studies of Rebeccamycin Analogues Modified in the Carbohydrate Moiety
Authors: Animati Fabio , Berettoni Marco , Bigioni Mario , Binaschi Monica , Felicetti Patrizia , Gontrani Lorenzo , Incani Ottaviano , Madami Andrea , Monteagudo Edith , Olivieri Lauso , Resta Stefano , Rossi Cristina , Cipollone Amalia 
Published: December 2007

AbstractA new series of indolocarbazole glycosides containing disaccharides were synthesized and their in vitro antiproliferative activity was evaluated against three human cancer cell lines (A2780, H460, and GLC4). Cytotoxicity appeared to be remarkably affected by the regio‐ and stereochemical features of the disaccharide moiety. In vivo antitumor activity of the compounds studied, two of which having IC50<100 nm, was determined using ovarian cancer cell line A2780 xenografted on nude mice. One compound showed an efficacy similar to that of the reference compound edotecarin, though with a lower long‐lasting activity. The topoisomerase I inhibitory properties of some compounds were also examined. Molecular dynamics simulations of the ternary topoisomerase I–DNA–ligand complexes were performed to analyze the structural features of topoisomerase I poisoning with this class of indolocarbazoles. A plausible explanation of their biological behavior was provided. These theoretical results were compared with the recently published crystal structure of an indolocarbazole monosaccharide bound to the covalent human topoisomerase I–DNA complex.
C‐peptide constricts pancreatic islet arterioles in diabetic, but not normoglycaemic mice
Authors: Nordquist Lina , Lai En Yin , Sjöquist Mats , Jansson Leif , Persson A. Erik G. 
Published: December 2007

AbstractBackgroundPancreatic islet blood flow is regulated separately from that of the exocrine pancreas, and a consistent finding during impaired glucose tolerance is an increased blood perfusion. The aim of the present study was to investigate whether C‐peptide affects pancreatic islet arterioles in normal and diabetic mice.Materials and MethodsControl and diabetic C57‐Bl mice were studied after 2 weeks of alloxan‐induced diabetes. Islet arterioles were dissected and microperfused with Dulbecco's modified Eagle medium (DMEM) solution. The effect of luminal application of mouse C‐peptide was investigated.ResultsC‐peptide reduced the diameter of islet arterioles from diabetic mice (−10 ± 4%, P < 0.05) compared to base‐line values, whilst arterioles from normoglycaemic animals did not respond to C‐peptide (P = 0.2).ConclusionThese findings suggest a role for C‐peptide in the regulation of islet blood flow, especially during conditions with impaired glucose tolerance. Copyright © 2007 John Wiley & Sons, Ltd.
Engagement of NOD2 has a dual effect on proIL‐1β mRNA transcription and secretion of bioactive IL‐1β
Authors: Ferwerda Gerben , Kramer Matthijs , de Jong Dirk , Piccini Alessandra , Joosten Leo A. , DevesaGiner Isabel , Girardin Stephen E. , Adema Gosse J. , van der Meer Jos W. M. , Kullberg Bart‐Jan , Rubartelli Anna , Netea Mihai G. 
Published: December 2007

AbstractSynthesis and release of pro‐inflammatory cytokines, such as IL‐1β, play a crucial role in the intestinal inflammation that characterizes Crohn's disease. Mutations in the nucleotide oligomerization domain 2 (NOD2) gene are associated with an increased risk of Crohn's disease. Although it is known that NOD2 mediates cytokine responses to muramyl dipeptide (MDP), it is yet unclear whether NOD2 stimulation mediates only transcription of pro‐IL‐1β mRNA, or whether NOD2 is also involved in the activation of caspase‐1 and release of active IL‐1β. By investigating the response of MNC from Crohn's disease patients homozygous for the 3020insC NOD2 mutation, we were able to show that NOD2 signaling after stimulation with MDP has a dual effect by activating proIL‐1β mRNA transcription and inducing release of bioactive IL‐1β. Because NOD2 engagement amplifies TLR stimulation, we investigated whether activation of caspase‐1 by MDP is involved in the NOD2/TLR synergism. The synergy in IL‐1β production between NOD2 and TLR is mediated at post‐translational level in a caspase‐1‐dependent manner, which indirectly suggests that NOD2 also induces caspase‐1 activation. In contrast, the synergy in TNF‐α production after stimulation with MDP and LPS is induced at transcriptional level. This demonstrates that both caspase‐1‐dependent and ‐independent mechanisms are involved in the synergy between NOD2 and TLR.
Hospital financial condition and the quality of patient care
Authors: Bazzoli Gloria J. , Chen Hsueh‐Fen , Zhao Mei , Lindrooth Richard C. 
Published: December 2007

AbstractConcerns about deficiencies in the quality of care delivered in US hospitals grew during a time period when an increasing number of hospitals were experiencing financial problems. Our study examines a six‐year longitudinal database of general acute care hospitals in 11 states to assess the relationship between hospital financial condition and quality of care. We evaluate two measures of financial performance: operating margin and a broader profitability measure that encompasses both operating and non‐operating sources of income. Our model specification allows for gradual adjustments in quality‐enhancing activities and recognizes that current realizations of patient quality may affect future financial performance. Empirical results suggest that there is a relationship between financial performance and quality of care, but not as strong as suggested in earlier research. Overall, our results suggest that deep financial problems that go beyond the patient care side of business may be important to prompting quality problems. Copyright © 2007 John Wiley & Sons, Ltd.
Microvascular free‐tissue transfer for head and neck reconstruction in Jehovah's Witness patients
Authors: Skoner Judith M. , Wax Mark K. 
Published: December 2007

AbstractBackground.Jehovah's Witnesses' religious convictions disallow blood transfusion. Major surgery in these patients is therefore problematic. The objective of this study is to describe our experience with microvascular reconstruction of complex head and neck defects in Jehovah's Witness patients.Methods.This was a retrospective review of all Jehovah's Witnesses' patients undergoing head and neck free‐flap reconstruction at a tertiary academic referral center from 1997 to 2006.Results.Five Jehovah's Witnesses patients underwent a total of 7 free‐flap reconstructions (6 radial, 1 rectus). Four flaps were immediate: 1 osteocutaneous radial forearm, 2 fasciocutaneous radial forearm, and 1 rectus abdominus myocutaneous. One fasciocutaneous radial forearm flap was staged. Two patients were planned secondary reconstructions, both facsciocutaneous radial forearm. Iron supplements and/or erythropoietin were administered perioperatively in 6 of the 7 microvascular reconstructions. Selective external carotid embolization was performed preoperatively in 1 patient. Hematocrit levels were 36% to 46% preoperatively and 30% to 41% postoperatively. Immediate postoperative hematocrit decline was 5.2% (3.0% to 6.0%). No transfusions or blood products were administered.Conclusions.Our case series supports the feasibility of head and neck free‐flap reconstruction in these challenging patients. © 2007 Wiley Periodicals, Inc. Head Neck, 2008