bluuebunny/crossref_metadata_2025_split huggingface dataset:
West Nile virus: lessons from the 21st century
Authors: Wilkins Pamela A. , Piero Fabio Del 
Published: March 2004

AbstractIntroduction: West Nile virus (WNV) first appeared in the United States in 1999, causing illness and death in birds, horses, and humans. While the initial outbreak of this sometimes deadly viral disease was limited to the northeastern United States, the virus had an inexorable migration across the continental United States over the next 3 years, causing huge losses among the affected species. The purpose of this review is to present currently available information regarding the epi‐demiology, diagnosis, treatment, and prevention of WNV infection. Veterinarians, particularly those in an emergency practice, serve as an important source of reliable information regarding this disease for animal owners and the public in general.Data sources: Data sources used for the preparation of this review include computer‐based searches of PubMed and Commonwealth Agricultural Bureaux (CAB) abstracts. A search in PubMed using ‘West Nile’ retrieved 1468 ‘hits’ or references, while a similar search in CAB abstracts produced 815 references. Additional information was obtained from various meeting proceedings, particularly data presented in abstract form, and from the Centers for Disease Control (CDC) website dedicated to WNV.Human data synthesis: Prior to the mid‐1990s, reported large‐scale epidemics of WNV infection in humans predominantly presented as acute, mild, febrile disease, sometimes associated with lymphadenopathy and skin rash. The recent large epidemic in the United States, in contrast, has prominently featured encephalitis, particularly among the elderly. Additionally, polio‐encephalomyelitis‐like complications resulting in long‐term neurologic sequelae have been reported. There are many WNV‐permissive native avian and mosquito hosts in the Unites States and there appear to be few limitations to the spread of the disease in the United States. It is expected that the virus will be identified in all 48 continental states, Mexico, and Canada by the end of 2003.Veterinary data synthesis: The horse is the animal species most affected by the recent WNV epidemic in the United States, and losses to the equine industry have been large and unprecedented. A United States Department of Agriculture (USDA)‐approved vaccine against WNV has been in use in horses since 2001 and appears to be effective in limiting the incidence of disease in well‐vaccinated populations. WNV infection has been documented in other species of mammals, including camelids (alpaca/llamas) and dogs, and veterinarians should include WNV as a differential diagnosis for animals presenting with clinical signs consistent with central nervous system infection. A large concern exists for endangered bird populations, particularly birds of prey, whether in zoos or in the wild.
Long-Term Survival of a Patient with Congenital Central Hypoventilation Syndrome despite the Lack of Continuous Ventilatory Support
Authors: Windisch Wolfram , Hennings Ellen , Storre Jan Hendrik , Matthys Heinrich , Sorichter Stephan 
Published: March 2004

Untreated idiopathic congenital central hypoventilation syndrome (CCHS) is thought to cause infant death within 1–2 months. Here we present an adult patient with CCHS who survived without continuous ventilatory support, despite hypoventilation from early childhood onward. The diagnosis was confirmed at the age of 22 years, when the patient presented with hypoventilation during the night (PaCO<sub>2</sub> 60 mm Hg, PaO<sub>2</sub> 56 mm Hg, pH 7.32 HCO<sup>–</sup><sub>3</sub> 30 mmol/l) but hyperventilation when awake (PaCO<sub>2</sub> 26 mm Hg, PaO<sub>2</sub> 81 mm Hg, pH 7.56, HCO<sup>–</sup><sub>3</sub> 23 mmol/l). The maximal hematocrit was 77%. Despite mental retardation, noninvasive positive pressure ventilation (NPPV) could be successfully established. NPPV-supported ventilation during the night (PaCO<sub>2</sub> 36, PaO<sub>2</sub> 84 mm Hg, pH 7.47, HCO<sup>–</sup><sub>3</sub> 25 mmol/l) reduced hematocrit values (40.6 to 36.8%) over a period of 4 years. In conclusion, long-term survival with CCHS is possible without continuous ventilatory support. Spontaneous improvement of hypoventilation during sleep throughout childhood is possible and hyperventilation during wakefulness may occur in patients with CCHS. CCHS can be managed with NPPV despite mental retardation, even over a long-term period.
Chemie und Biologie von Terpentrilactonen ausGinkgo biloba
Authors: Strømgaard Kristian , Nakanishi Koji 
Published: March 2004

AbstractGinkgo biloba– der Ginkgobaum – ist die älteste lebende Baumart der Welt. Ginkgo‐Präparate sind ein wichtiger Bestandteil in der traditionellen chinesischen Medizin, und in den letzten Jahren haben die Blattextrakte als Phytopräparat in Europa und als Nahrungsergänzungsmittel weltweit breiten Absatz gefunden. Zu den postulierten Wirkungen desGinkgo‐biloba‐Extrakts gehören die Verbesserung der Gedächtnisleistung, die Steigerung der Blutzirkulation und eine Verzögerung der Alzheimer‐Demenz. Was den Extrakt so einzigartig macht, sind die Terpentrilactone – Ginkgolide und Bilobalid –, die als strukturell komplexe Moleküle attraktive Zielstrukturen für Totalsynthesen waren. Es wird angenommen, dass Terpentrilactone für die neuroregulatorischen Eigenschaften derGinkgo‐biloba‐Extrakte mit ausschlaggebend sind. Eine Reihe biologischer Wirkungen der in den letzten Jahren entdeckten Terpentrilactone macht diese zu aussichtsreichen pharmakologischen Substanzen.
Nanokatalyse: alter Wein in neuen Schläuchen oder etwas wirklich Neues?
Authors: Schlögl Robert , Abd Hamid Sharifah Bee 
Published: March 2004

AbstractDas Nanofieber hat die Forschung über heterogene Katalysatoren erreicht. Begreift man Nanokatalyse als einen Paradigmenwechsel in der Katalysatorherstellung hin zur Synthese von Katalysatoren mit auf mehreren Größenskalen kontrollierten Eigenschaften, so ergibt sich folgender Ansatz: Die Struktur lässt sich durch einen Aufbau des Katalysators als anorganisches Polymer kontrollieren. Primäre, sekundäre und tertiäre Struktur des Polymers entsprechen molekularen Baueinheiten und deren Verknüpfungen, der Defektstruktur des Festkörpers bzw. der Teilchenmorphologie. Hochdurchsatzexperimente zur Optimierung der Syntheseparameter, die von in situ erhaltenen analytischen Daten der Herstellprozesse geführt werden, sind ein Weg zu Katalysatoren, welche die hohen Erwartungen, die sich mit dem Prädikat “nano” verbinden, erfüllen können.
Nanocatalysis: Mature Science Revisited or Something Really New?
Authors: Schlögl Robert , Abd Hamid Sharifah Bee 
Published: March 2004

Abstract“Nanomania” has reached the area of heterogeneous catalysis. Nanosized catalyst constituents are important for functions that require structural control over several scales of dimension. Nanocatalysis may be understood as a redefinition of catalyst synthesis: multidimensional structural control is exerted by considering catalysts as inorganic polymers rather than as close‐packed crystals. Primary, secondary, and tertiary structural hierarchies translate into molecular building blocks and linkers, the defect structure of crystals, and particle morphology. High‐throughput techniques and in situ synthetic analysis are the tools required to arrive at better defined catalytic materials that can fulfil the high expectations created by the incorporation of catalysts into the “nano” research field.
Novel Reaction Products from Thiobarbituric Acid of Biological Interest
Authors: Aly Ashraf A. , Mourad Aboul‐Fetouh E. , Hassan Alaa A. , Mohamed Nasr K. , Ali Bahaa A. , El‐Sayed Mohamed M. 
Published: March 2004

AbstractThe reactions of 1, 2‐dihydro‐2‐thioxo‐4, 6(1H, 5H)pyrimidinedione (1) with some π‐deficients have led to the formation of unexpected heterocyclic products such as anilinomethylenethioxopyrimidinedione, 2, 2'‐bis(pyrimidinecarbothioamide), allylthioxopyrimidinecarbothioamide, indenopyranopyrimidine and benzofuropyrimidine derivatives. A possible mechanism for the formation of these products is discussed, and the biological activity is determined.
Synthesis and Antimicrobial Evaluation of Some Novel Cholestane Heterocyclic Derivatives
Authors: Elmegeed Gamal A. , Wardakhan Wagnat W. , Younis Magdi , Louca Nadia A. 
Published: March 2004

AbstractThis study was performed to investigate the reactivity of 5α‐cholestan‐3‐one (1) towards various chemical reagents to produce new steroidal heterocyclic derivatives. The aminothieno[2, 3:2, 3]cholestane derivative 2 was synthesized according to Gewald's conditions. The diazonium salt of compound 2 coupled with malononitrile to afford dicyanomethylenhydrazinothieno[2′, 3′:2, 3]cholestane derivative 5. The behavior of compound 5 towards nitrogen nucleophiles and several active methylene reagents was investigated. Additionally, a variety of steroidal heterocyclic derivatives like compounds 15a, b‐22a, b were synthesized starting with 5α‐cholestan‐3‐one (1). The structures of the compounds were established based on the analytical and spectral data. The in vitro antimicrobial activity of some newly synthesized compounds against bacteria and fungi was studied.
Antiaggregating and Antithrombotic Activities of new 1, 2, 3‐Triazolecarboxamides
Authors: Cwiklicki Anke , Rehse Klaus 
Published: March 2004

AbstractTwenty five new triazolecarboxamides related to YC‐1 were prepared and tested for their antiplatelet (in vitro) and antithrombotic (in vivo) activities. Five of them inhibited the aggregation of blood platelets (Born test, inducer collagen) with IC50 values between 90 and 130 μM. Nine compounds exhibited significant antithrombotic properties with an inhibition of thrombus formation between 11 and 7%. Only one compound (8c) showed both, in vitro and in vivo effects. In vitro, the most active compounds were 11c and 12d. They inhibit platelet aggregation with IC50 = 90 and 95 μM. In vivo, 10a showed the strongest inhibition of thrombus formation with 11% in arterioles (5% in venules) after a single oral dose of 60 mg/kg. With serotonin as inducer both, 11c and 12d, showed lower IC50 values namely 25 or 30 μM, respectively. Additional antiplatelet activities were found for 11c against adrenaline (IC50 = 25 μM) and for 12d against platelet activating factor (PAF) (IC50 = 15 μM) as inducer.
Hypoglycemia induced changes in cell death and cell proliferation in the organogenesis stage embryonic mouse heart
Authors: Ghatnekar Gautam S. , Barnes Jill A. , Dow Janet L. , Smoak Ida W. 
Published: March 2004

AbstractBACKGROUNDHypoglycemia is a side effect of diabetes therapy and causes abnormal heart development. Embryonic heart cells are largely resistant to teratogen‐induced apoptosis.METHODSHypoglycemia was tested for effects on cell death and cell proliferation in embryonic heart cells by exposing mouse embryos on embryonic day (E) 9.5 (plug = E0.5) to hypoglycemia (30–50 mg/dl glucose) in vivo or in vitro for 24 hr. Long‐term effects of in vivo exposure on conceptus viability were evaluated at E18.5. Cell death was evaluated on E10.5 by: 1) two TUNEL assays in sectioned embryos to demonstrate DNA fragmentation; 2) confocal microscopy in whole embryos stained with Lysotracker; 3) flow cytometry in dispersed heart cells stained for TUNEL and myosin heavy chain (MHC) to quantify and characterize cell type susceptibility; and 4) immunohistochemistry (IHC) and Western analysis in sectioned embryos to evaluate potential involvement of caspase‐3 active subunit and p53. Effects on cell proliferation were evaluated by IHC and Western analysis of proliferating cell nuclear antigen (PCNA).RESULTSIn vivo hypoglycemic exposure on E9.5 reduced viability in conceptuses examined on E18.5. Hearts examined on E10.5 demonstrated increased TUNEL and Lysotracker staining. In hearts of embryos exposed to hypoglycemia, flow cytometry demonstrated increased TUNEL‐positive cells and cells dual‐labeled for TUNEL and MHC. Protein expression of caspase‐3 active subunit and p53 was increased and PCNA was markedly reduced in hearts of embryos exposed to hypoglycemia.CONCLUSIONSHypoglycemia reduces embryonic viability, induces significant cell death, and reduces cell proliferation in the E9.5 mouse heart, and these processes may involve active caspase‐3 and p53. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Evidence that the risk of spina bifida is influenced by genetic variation at the NOS3 locus
Authors: Brown Karen S. , Cook Michelle , Hoess Katy , Whitehead Alexander S. , Mitchell Laura E. 
Published: March 2004

AbstractBACKGROUND:There is substantial evidence that the risk of spina bifida, a malformation of the caudal neural tube, may be associated with maternal or embryonic disturbances in the folate–homocysteine metabolic axis. Hence, variants of genes that influence this pathway represent an intriguing group of candidate genes for spina bifida and other neural tube defects (NTD). A common variant of the gene for endothelial nitric oxide synthase (NOS3 G894T) was recently added to this group of NTD candidate genes, based on a report demonstrating that homozygosity for the T allele of this variant is associated with increased homocysteine levels in normal adult populations.METHODS:The association between the risk of spina bifida and both the maternal and embryonic genotype for the NOS3 G894T variant was evaluated in data from 301 families by using the transmission disequilibrium test (TDT) and log‐linear modeling.RESULTS:Analyses of these data using the TDT provided no evidence that the risk of spina bifida was significantly related to either the maternal or embryonic NOS3 genotype. However, the log‐linear analyses indicated that the risk of spina bifida was significantly associated with the embryonic, but not the maternal, genotype for the NOS3 G894T variant.CONCLUSIONS:The results of the present analyses suggest that the embryonic NOS3 G894T genotype is associated with the risk of spina bifida. Moreover, these analyses highlight the importance of a detailed examination of the study data. Had these analyses been restricted to the methodologically simpler TDT, the association between the NOS3 G894T genotype and risk of spina bifida may well have been overlooked. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Excess birth prevalence of Hypoplastic Left Heart syndrome in eastern Wisconsin for birth cohorts 1997–1999
Authors: Cronk Christine E. , Pelech Andrew N. , Malloy Marsha E. , McCarver D. Gail 
Published: March 2004

AbstractBACKGROUNDHypoplastic Left Heart syndrome (HLHS) is a group of cardiac malformations involving underdevelopment of the left heart with an inability to maintain systemic circulation. Because of a clinical impression of excess HLHS prevalence, we completed a medical record review of cases born from 1997 through 1999 who were Wisconsin residents and seen at the Children's Hospital of Wisconsin (CHW).METHODSCases were identified either in the CHW medical records database or the Division of Pediatric Cardiology database and confirmed by echocardiogram, catheterization, surgery, or autopsy. U.S. and international surveillance systems were used to estimate population risk. Rates per 10,000 births were computed for eastern Wisconsin and four regions within this portion of the state, and compared to the estimated population risk. The same methods were used to evaluate whether rates for tetralogy of Fallot and transposition of the great arteries were elevated.RESULTSA total of 61 cases were ascertained yielding a birth prevalence of 3.7 per 10,000 births, which was greater than the estimated population risk of 2.79. The rate for the southeast region also exceeded the expected rate. The most urban and industrialized areas had the highest rates. Rates for the other two diagnoses evaluated were not different from estimated population risks.CONCLUSIONSEastern Wisconsin, particularly the urban southeast region, had elevated rates of HLHS. Because of the geographic clustering of high rates, environmental factors may be associated with this finding. Birth Defects Research (Part A) 70:114–120, 2004. © 2004 Wiley‐Liss, Inc.
Determination of organochlorine compounds in human biological samples by GC‐MS/MS
Authors: Frías Mercedes Moreno , Torres Margarita Jiménez , Frenich Antonia Garrido , Martínez Vidal Jose Luis , Olea‐Serrano Fátima , Olea Nicolás 
Published: March 2004

AbstractA study was undertaken to determine the extent of organochlorine pesticide (OP) and polychlorinated biphenyl (PCB) contamination in infant formula milk and in the human milk, fat and serum of women from an agricultural area in Southern Spain. A procedure is proposed that simultaneously detects trace levels of lindane, endosulfan‐ether, vinclozolin, aldrin, endosulfan‐lactone, endosulfan‐alpha, 4,4′DDE, 2,4′DDT, endosulfan‐beta, 4,4′DDT, kepone, endosulfate‐sulfate, methoxychlor, mirex, 2,3,4 PCB, 2,2′,4,5 PCB, 2,3,4,5 PCB and 2,2′,3,3′,6,6′PCB. After liquid–liquid or solid–liquid extraction, the extract of the sample was cleaned by high performance liquid chromatography (HPLC) and the ﬁrst eluted fraction was analysed by gas chromatography (GC) with mass spectrometry (MS) detector in tandem mode. To evaluate the validity of the method the following parameters were studied: linearity, detection limits, quantiﬁcation limits, speciﬁcity, percentage recovery and precision. A study of the uncertainty associated with the analytical method was also carried out. Copyright © 2003 John Wiley & Sons, Ltd.
Quantifying and handling errors in instrumental measurements using the measurement error theory
Authors: Andersen C. M. , Bro R. , Brockhoff P. B. 
Published: March 2004

AbstractMeasurement error modelling is used for investigating the influence of measurement/sampling error on univariate predictions of water content and water‐holding capacity (reference measurement) from nuclear magnetic resonance (NMR) relaxations (instrumental) measured on two gadoid fish species. This is a new way of using the measurement error theory. Reliability ratios illustrate that the models for the two fish species are influenced differently by the error. However, the error seems to influence the predictions of the two reference measures in the same way. The effect of using replicated x‐measurements is illustrated by simulated data and by NMR relaxations measured several times on each fish. The standard error of the physical determination of the reference values is lower than the standard error of the NMR measurements. In this case, lower prediction error is obtained by replicating the instrumental measurements. A new general formula is given for how to correct the least squares regression coefficient when a different number of replicated x‐measurements is used for prediction than for calibration. It is shown that the correction should be applied when the number of replicates in prediction is less than the number in calibration. This can be relevant for on‐line applications and in other situations where it is important to make fast measurements in the prediction phase. Copyright © 2004 John Wiley & Sons, Ltd.
Nanostructured Polyaniline Sensors
Authors: Huang Jiaxing , Virji Shabnam , Weiller Bruce H. , Kaner Richard B. 
Published: March 2004

AbstractThe conjugated polymer polyaniline is a promising material for sensors, since its conductivity is highly sensitive to chemical vapors. Nanofibers of polyaniline are found to have superior performance relative to conventional materials due to their much greater exposed surface area. A template‐free chemical synthesis is described that produces uniform polyaniline nanofibers with diameters below 100 nm. The interfacial polymerization can be readily scaled to make gram quantities. Resistive‐type sensors made from undoped or doped polyaniline nanofibers outperform conventional polyaniline on exposure to acid or base vapors, respectively. The nanofibers show essentially no thickness dependence to their sensitivity.
Diaroyl(methanato)boron Difluoride Compounds as Medium‐Sensitive Two‐Photon Fluorescent Probes
Authors: Cogné‐Laage Emmanuelle , Allemand Jean‐François , Ruel Odile , Baudin Jean‐Bernard , Croquette Vincent , Blanchard‐Desce Mireille , Jullien Ludovic 
Published: March 2004

AbstractThis paper evaluates the use of diaroyl(methanato)boron difluoride compounds for designing efficient fluorescent probes through two‐photon absorption. Three different pathways allowing for the syntheses of symmetrical and dissymmetrical molecules are reported. The stable diaroyl(methanato)boron difluoride derivatives can be easily obtained in good yields. They exhibit a large one‐photon absorption that is easily tuned in the near‐UV range. Their strong fluorescence emission covers the whole visible domain. In addition to these attractive linear properties, several diaroyl(methanato)boron difluoride derivatives possess significant cross sections for two‐photon absorption. The derived structure–property relationships are promising for designing new generations of molecules relying on the diaroyl(methanato)boron difluoride backbone.
Self‐Assembly of Normal Alkanes on the Au (111) Surfaces
Authors: Zhang Hai‐Ming , Xie Zhao‐Xiong , Mao Bing‐Wei , Xu Xin 
Published: March 2004

AbstractThe self‐assembled monolayers (SAMs) of normal alkanes (n−CnH2n+2) with different carbon chain lengths (n=14–38) in the interfaces between alkane solutions (or liquids), and the reconstructed Au (111) surfaces have been systematically studied by means of scanning tunneling microscopy (STM). In contrast to previous studies, which concluded that some n‐alkanes (n=18–26) can not form well‐ordered structures on Au (111) surfaces, we observed SAM formations for all these n‐alkanes without any exceptions. We find that gold reconstruction plays a critical role in the SAM formation. The alkane monolayers adopt a lamellar structure in which the alkane molecules are packed side‐by‐side, to form commensurate structures with respect to the reconstructed Au (111) surfaces. The carbon skeletons are found to lie flat on the surfaces, which is consistent with the infrared spectroscopic studies. Interestingly, we find that two‐dimensional chiral lamellar structures form for alkanes with an even carbon number due to the specific packing of alkane molecules in a tilted lamella. Furthermore, we find that the orientation of alkane molecules deviates from the exact [01$\bar 1$] direction, because of the intermolecular interactions among the terminal methyl groups of neighboring lamellae; this results in differences of molecular orientation between mirror structures of adjacent zigzag alkane lamellae. Structural models have been proposed, that shed new light on monolayer formation.
Synthesis and Properties of para‐Substituted NCN‐Pincer Palladium and Platinum Complexes
Authors: Slagt Martijn Q. , Rodríguez Gema , Grutters Michiel M. P. , Klein Gebbink Robertus J. M. , Klopper Wim , Jenneskens Leonardus W. , Lutz Martin , Spek Anthony L. , van Koten Gerard 
Published: March 2004

AbstractA variety of para‐substituted NCN‐pincer palladium(II) and platinum(II) complexes [MX(NCN‐Z)] (M=PdII, PtII; X=Cl, Br, I; NCN‐Z=[2,6‐(CH2NMe2)2C6H2‐4‐Z]−; Z=NO2, COOH, SO3H, PO(OEt)2, PO(OH)(OEt), PO(OH)2, CH2OH, SMe, NH2) were synthesised by routes involving substitution reactions, either prior to or, notably, after metalation of the ligand. The solubility of the pincer complexes is dominated by the nature of the para substituent Z, which renders several complexes water‐soluble. The influence of the para substituent on the electronic properties of the metal centre was studied by 195Pt NMR spectroscopy and DFT calculations. Both the 195Pt chemical shift and the calculated natural population charge on platinum correlate linearly with the σp Hammett substituent constants, and thus the electronic properties of predesigned pincer complexes can be predicted. The σp value for the para‐PtI group itself was determined to be −1.18 in methanol and −0.72 in water/methanol (1/1). Complexes substituted with protic functional groups (CH2OH, COOH) exist as dimers in the solid state due to intermolecular hydrogen‐bonding interactions.