bluuebunny/crossref_metadata_2025_split huggingface dataset:
A time‐stepping method for stiff multibody dynamics with contact and friction
Authors: Anitescu Mihai , Potra Florian A. 
Published: October 2002

AbstractWe define a time‐stepping procedure to integrate the equations of motion of stiff multibody dynamics with contact and friction. The friction and non‐interpenetration constraints are modelled by complementarity equations. Stiffness is accommodated by a technique motivated by a linearly implicit Euler method. We show that the main subproblem, a linear complementarity problem, is consistent for a sufficiently small time step h. In addition, we prove that for the most common type of stiff forces encountered in rigid body dynamics, where a damping or elastic force is applied between two points of the system, the method is well defined for any time step h. We show that the method is stable in the stiff limit, unconditionally with respect to the damping parameters, near the equilibrium points of the springs. The integration step approaches, in the stiff limit, the integration step for a system where the stiff forces have been replaced by corresponding joint constraints. Simulations for one‐ and two‐dimensional examples demonstrate the stable behaviour of the method. Published in 2002 by John Wiley & Sons, Ltd.
Living radical graft polymerization of methyl methacrylate to polyethylene film with typical and reverse atom transfer radical polymerization
Authors: Yamamoto Katsuhiro , Miwa Youhei , Tanaka Hiroyuki , Sakaguchi Masato , Shimada Shigetaka 
Published: October 2002

AbstractNickel‐mediated atom transfer radical polymerization (ATRP) and iron‐mediated reverse ATRP were applied to the living radical graft polymerization of methyl methacrylate onto solid high‐density polyethylene (HDPE) films modified with 2,2,2‐tribromoethanol and benzophenone, respectively. The number‐average molecular weight (Mn) of the free poly(methyl methacrylate) (PMMA) produced simultaneously during grafting grew with the monomer conversion. The weight‐average molecular weight/number‐average molecular weight ratio (Mw/Mn) was small (<1.4), indicating a controlled polymerization. The grafting ratio showed a linear relation with Mn of the free PMMA for both reaction systems. With the same characteristics assumed for both free and graft PMMA, the grafting was controlled, and the increase in grafting ratio was ascribed to the growing chain length of the graft PMMA. In fact, Mn and Mw/Mn of the grafted PMMA chains cleaved from the polyethylene substrate were only slightly larger than those of the free PMMA chains, and this was confirmed in the system of nickel‐mediated ATRP. An appropriate period of UV preirradiation controlled the amount of initiation groups introduced to the HDPE film modified with benzophenone. The grafting ratio increased linearly with the preirradiation time. The graft polymerizations for both reaction systems proceeded in a controlled fashion. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3350–3359, 2002
1,4‐Addition polymerization of 1,4‐bis(4‐benzylpyridinium)butadiyne triflate in a dipolar aprotic solvent
Authors: Iwase Yoichiro , Kondo Koichi , Kamada Kenji , Ohta Koji 
Published: October 2002

Abstract1,4‐Bis(4‐benzylpyridinium)butadiyne triflate was aggregated in dimethylformamide and spontaneously converted into the 1,4‐addition type of polydiacetylene. The polymerization took place in a dipolar aprotic solvent with a large dielectric constant that could enhance the aggregation of the ionic diacetylene salt through the electrostatic interaction. The molecular weight of the diacetylene was leveled off after 30 h at 80 °C to reach 1.5 × 104 (number‐average molecular weight) that consisted of the 1,4‐addition type of polydiacetylene similar to polydiacetylenes obtained in the conventional solid‐state polymerization. Electron spin resonance spectra revealed that diradicals were generated at the earlier state aggregation to give rise to a solution polymerization. The UV spectra also suggested the presence of the activated aggregation associated with the polymerization as well as the eximer emission spectra. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3534–3541, 2002
Molluscicidal and antifungal activity of Erigeron speciosus steam distillate
Authors: Meepagala Kumudini M , Sturtz George , Wise David , Wedge David E 
Published: October 2002

AbstractThe steam‐distilled fraction of the aerial parts of Erigeron speciosus (Lindl) DC was tested for activity against strawberry plant pathogenic fungi Botrytis cinerea Pers ex Fr, Colletotrichum acutatum Simmonds, C fragariae Brooks, C gloeosporioides (Penz) Penz & Sacc, and the intermediate host snail Planobdella trivolvis that harbors the trematode, Bolbophorus confusus, that infests and causes severe infections in pond‐raised catfish in the Mississippi Delta region of the USA. Bioautography on silica TLC plates demonstrated antifungal activity in the steam distillate. Preliminary bioassays of the steam distillate indicated the presence of phytochemicals toxic to P trivolvis. The bioactive compounds methyl 2Z, 8Z‐deca‐2,8‐diene‐4,6‐diynoate and its 2E, 8E isomer were isolated by bioassay‐guided fractionation and chromatographic techniques and identified by 1H NMR spectroscopy.© 2002 Society of Chemical Industry
Neutralization of neutrophin‐3 in the ventral tegmental area or nucleus accumbens differentially modulates cocaine‐induced behavioral plasticity in rats
Authors: Freeman Antoinette Y. , Pierce R. Christopher 
Published: October 2002

AbstractThese experiments were designed to assess the influence of neurotrophin‐3 (NT‐3) and brain‐derived neurotrophic factor (BDNF) in the mesoaccumbens dopamine system on the initiation of behavioral sensitization to cocaine. A neutralizing antibody for NT‐3, BDNF or their vehicle was administered into the ventral tegmental area (VTA) or nucleus accumbens prior to each of four daily injections of 15 mg/kg cocaine. Behavioral sensitization was operationally defined as a significant increase in the behavioral response to cocaine relative to the first daily injection. Results indicated that the NT‐3 antibody had differential effects when administered into the VTA or nucleus accumbens. Intra‐VTA microinjection of anti‐NT‐3 resulted in enhanced sensitization to repeated cocaine injections in that the cocaine‐induced behavioral response in the anti‐NT‐3 group was significantly greater than the vehicle group following the second and third daily injections of cocaine. Administration of anti‐NT‐3 into the nucleus accumbens increased the behavioral response to cocaine over all 4 days of cocaine administration, with no sensitization of this behavioral response. In contrast, pretreatment with anti‐BDNF into the VTA or nucleus accumbens had no influence on the initiation of behavioral sensitization to cocaine. Taken together, these data indicate that neutralization of NT‐3 in the VTA enhances cocaine‐induced behavioral sensitization, while administration of the NT‐3 antibody into the nucleus accumbens increases the hyperactive behavioral response induced by cocaine but impairs the further development of behavioral sensitization. Synapse 46:57–65, 2002. © 2002 Wiley‐Liss, Inc.
New Genes for Phylogenetic Studies of Lichenized Fungi: Glyceraldehyde-3-Phosphate Dehydrogenase and Beta-Tubulin Genes
Authors: Myllys Leena , Stenroos Soili , Thell Arne 
Published: October 2002

AbstractPrimers for amplification and sequencing of partial glyceraldehyde-3-phosphate dehydrogenase (gpd) gene were designed for lichenized fungi. The 5’ gpd primer is most probably fungal specific, since a BLAST search in GenBank found identical sequences only from ascomycetous taxa, whereas the 3’ gpd primer was more universal. Utility of the gpd primers and previously designed beta-tubulin primers was tested in nine lichen taxa. Both the gpd and beta-tubulin primer pairs amplified in most of the taxa examined: the gpd primers generated a c. 1100 nucleotide fragment, whereas the PCR product obtained from the beta-tubulin primers was c. 900 nucleotides long. The gpd amplification products of Cladonia arbuscula and C. rangiferina were sequenced and both were found to contain three introns, the length of which varied between 49 to 83 nucleotides. To examine the applicability of gpd sequences in resolving relationships within Ascomycota, trees were calculated from 22 fungal gpd sequences obtained from GenBank together with the two Cladonia sequences using parsimony jackknifing. The gpd tree was compared with the SSU rDNA tree of the respective species (or genera). A similar analysis of the beta-tubulin gene was not performed, because only a few beta-tublin sequences from the same taxa were available in GenBank. The gpd tree was well resolved but in conflict with the SSU rDNA tree. In contrast to the SSU rDNA tree, the gpd tree did not support the monophyly of the Ascomycota. Analysis of the combined data set produced a tree very similar to that of the SSU rDNA data. However, the relationship of Lecanorales to the other orders remained unresolved. Even though gpd and beta-tubulin are highly conserved proteins, the third codon positions and introns are variable and both genes have the potential for inferring phylogenetic relationships at the lower taxonomic levels in the lichenized fungi. The two genes may be useful even below species level, depending on the species investigated.
Maternal deaths associated with cesarean section in Enugu, Nigeria
Authors: Ozumba B.C , Anya S.E 
Published: October 2002

AbstractMaternal deaths from cesarean sections in Nigeria are exceptionally high and result from avoidable causes such as hemorrhagic shock, sepsis and hypertensive disorders in pregnancy. Increased involvement of specialists in the care and improved intra and post‐operative management of cases are advocated to reduce the high maternal mortality rate.
Multisensory integration for spatial orientation in trait anxiety subjects: absence of visual dependence
Authors: Viaud-Delmon I. , Berthoz A. , Jouvent R. 
Published: October 2002

SummaryStudies suggest a greater reliance on visual information for maintaining balance in anxious subjects. Nevertheless, links between this supposed preferred visual processing and spatial orientation have not yet been evaluated. Two groups of subjects differing in their level of trait anxiety were formed. Equipped with a head-mounted visual display, they learned a virtual corridor using passive translation but active rotation, both with normal and with two different conflicting sensory conditions. After two visual navigation trials in the corridor, they were blindfolded and asked to reproduce the same trajectory from memory. In addition, subjects drew a map of the remembered corridor. Anxious subjects were comparable to non-anxious subjects when asked to reproduce the trajectory from memory, but exhibited a deficit when drawing a map of the corridor they were in. The results do not support the hypothesis that anxious subjects use preferentially one type of sensory cue over another for spatial orientation, but instead manifest difficulties in constructing more global representations of space.
Evaluation of Aquatic Environment by Polyaromatic Hydrocarbon Concentration and Induction of EROD Activity in HepG2 Cells
Authors: Nagashima Hiroshi , Ono Yoshiro , Sekiguchi Motochika 
Published: October 2002

Abstract
Environmental contamination by polyaromatic hydrocarbons (PAHs) and dioxin-like compounds was evaluated by chemical analysis and biological tests. Though soils and road dust samples revealed more potent biological activities than incinerator ashes, the contribution of PAHs were low.
A New Class of High-Performance Red-Fluorescent Dyes for Organic Electroluminescent Devices, [7-Diethylamino-3-(2-thienyl)chromen-2-ylidene]-2,2-dicyanovinylamine and {10-(2-Thienyl)-2,3,6,7-tetrahydro-1H,5H-chromeno[8,7,6-ij]quinolizin-11-ylidene}-2,2-dicyanovinylamine
Authors: Yu Junsheng , Shirota Yasuhiko 
Published: October 2002

Abstract
A new and better generation of red-fluorescent dyes based on a chromene-2-ylidene moiety, [7-diethylamino-3-(2-thienyl)chromen-2-ylidene]-2,2-dicyanovinylamine (ACY) and {10-(2-thienyl)-2,3,6,7-tetrahydro-1H,5H-chromeno[8,7,6-ij]quinolizin-11-ylidene}-2,2-dicyanovinylamine (CQY), has been designed and synthesized, and has been proven to function as excellent red-emitting dopants in high-performance red-emitting organic electroluminescent devices.
Crystal Structure of a Luminescent Complex Sm(HTH)3Phen
Authors: Guo Junfang , Fu Lianshe , Li Huanrong , Zheng Youxuan , Liu Fengyi , Meng Qingguo , Wang Jun , Zhang Hongjie 
Published: October 2002

Abstract
The crystal structure of Sm(HTH)3Phen [HTH: 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)-1,3-hexanedione, Phen: 1,10-Phenanthroline] has been determined by single crystal X-ray diffraction and the coordination geometry of Sm atom is a dodecahedron. The complex can give the characteristic luminescence of Sm3+ upon UV excitation.
Solvent entropy contribution to the free energy of protein crystallization
Authors: Vekilov Peter G. , Feeling-Taylor Angela R. , Yau Siu-Tung , Petsev Dimiter 
Published: September 2002

We show with three proteins that trapping and release of the water molecules upon crystallization is a determinant of the crystallization thermodynamics. With HbC, a strong retrograde solubility dependence on temperature yields a high positive enthalpy of 155 kJ mol-1, i.e., crystallization is only possible because of the huge entropy gain of 610 J mol-1K-1, stemming from the release of up to 10 water molecules per protein intermolecular contact. With apoferritin, the enthalpy of crystallization is close to zero. The main component in the crystallization driving force is the entropy gain due to the release upon crystallization of two water molecules bound to one protein molecules in solution. With both proteins, the density of the growth sites imaged by AFM is in excellent agreement with a calculation using the crystallization free energy. With lysozyme, the entropy effect due to the restructuring of the water molecules is negative. This leads to higher solubility.
Evaluation of the Digene Hybrid Capture II Assay with the Rapid Capture System for Detection ofChlamydia trachomatisandNeisseria gonorrhoeae
Authors: Van Der Pol B. , Williams J. A. , Smith N. J. , Batteiger B. E. , Cullen A. P. , Erdman H. , Edens T. , Davis K. , Salim-Hammad H. , Chou V. W. , Scearce L. , Blutman J. , Payne W. J. 
Published: September 2002

ABSTRACTScreening for chlamydial and gonococcal infection has been strongly recommended for all sexually active women under the age of 26. Advances in the ability to detect infection by nucleic acid detection techniques have improved access to screening methods in routine clinical practices. To meet the increasing demand for testing, a high-throughput system is desirable. We evaluated the performance of the Hybrid Capture 2 CT/GC (HC2) assay with the Digene Rapid Capture System (HC2-RCS). The results of HC2-RCS for endocervical samples from 330 women were compared to those of culture and the COBAS Amplicor PCR. For detection of chlamydial infection, HC2-RCS had a sensitivity and a specificity similar to those of PCR (P> 0.5) and an improved sensitivity compared to that of culture (P= 0.007). For identification of gonococcal infections, all assays performed similarly (P> 0.5). The performance of HC2-RCS was also compared to that of the manual HC2 format (HC2-M) with these samples and with 911 endocervical samples collected previously. The performance of HC2-RCS was equivalent to that of HC2-M; the overall concordance rates for the detection of chlamydia and gonorrhea were 99.7% (κ = 0.97) and 99.8% (κ = 0.97), respectively. When the HC2 assay was performed with a semiautomated system application designed for high throughput, it demonstrated high sensitivity and a high specificity for detection of bothChlamydia trachomatisandNeisseria gonorrhoeae.
Molecular Epidemiological Analysis of the Changing Nature of a Meningococcal Outbreak following a Vaccination Campaign
Authors: Shlush Liran I. , Behar Doron M. , Zelazny Adrian , Keller Nathy , Lupski James R. , Beaudet Arthur L. , Bercovich Dani 
Published: September 2002

ABSTRACT

A serogroup C meningococcal outbreak that occurred in an Israeli Arab village led to a massive vaccination campaign. During the subsequent 18 months, new cases of type B
Neisseria meningitidis
infection were revealed. To investigate the influence of vaccination on bacteriological epidemiology, bacteria were isolated from individuals at the outbreak location, patients with several additional other sporadic cases, and patients involoved in another outbreak. Haploid bacterial genomic DNA was mixed with a consensus PCR product to form a heteroduplex state that enabled multilocus sequence typing (MLST) to be combined with denaturing high-performance liquid chromatography (DHPLC) for a novel high-throughput molecular typing method called MLST-DHPLC. A 100% correlation was found to exist between the sequencing by MLST alone and the MLST-DHPLC method. Independent molecular typing by repetitive extragenic palindromic PCR discriminated the neisserial clones as well as the MLST-DHPLC method did. The occurrence of type B
N. meningitidis
in the postvaccination period might be attributed to the selection pressure applied to the bacteria by vaccination, suggesting a possible unwarranted outcome of vaccination with the quadrivalent vaccine for control of a serogroup C meningococcal outbreak. This is the first time that DHPLC has been applied to the genotyping of bacteria, and it proved to be more efficient than MLST alone.
Evaluation of PCR for Diagnosis of American Cutaneous Leishmaniasis in an Area of Endemicity in Northeastern Brazil
Authors: Rodrigues Eduardo Henrique Gomes , Felinto de Brito Maria Edileuza , Mendonça Mitzi Guedes , Werkhäuser Roberto P. , Coutinho Eridan M. , Souza Wayner V. , Militão de Albuquerque Maria de Fátima P. , Jardim Márcio L. , Abath Frederico G. C. 
Published: September 2002

ABSTRACT

PCR-based approaches targeting kinetoplast DNA were evaluated for the diagnosis of American cutaneous leishmaniasis (ACL) in regions of endemicity in northeastern Brazil. A total of 119 cutaneous biopsy specimens from patients with ACL and nonleishmaniasis cutaneous lesions were studied. Two PCR-based systems were used; one was specific for the subgenus
Viannia
, and the other was specific for the genus
Leishmania
. The PCR specific for the subgenus
Viannia
had a sensitivity of 95.4%, whereas the genus-specific PCR detected the target DNA in 88.2% of the samples tested. The specificities of the assays, determined with samples from a group with nonleishmaniasis cutaneous lesions, was 100%. The results of the conventional tests indicate that the sensitivities of the PCR-based methods were significantly higher than those of smear examination, histological staining, and isolation by culture (
P
< 0.05). Antibodies specific for
Leishmania braziliensis
were detected by indirect immunofluorescence in 82.9% of the patients tested. Parasites were isolated from 40 of 86 patients (46.5%). Sixty-seven percent of dermal scrapings and 66.2% of stained tissue sections were positive by microscopy. Amplified products from the subgenus-specific PCR hybridized with the
Leishmania panamensis
minicircle, confirming infection consistent with
L. braziliensis
. The evidence available at present incriminates
L. braziliensis
as the only causative agent of ACL in the state of Pernambuco in Brazil.
Pilot Study of the Genetic Diversity of the Pneumococcal Nasopharyngeal Flora among Children Attending Day Care Centers
Authors: Sá-Leão Raquel , Tomasz Alexander , Santos Sanches Ilda , de Lencastre Hermínia 
Published: September 2002

ABSTRACT

A pilot study was conducted to determine the genetic diversity of multiple colonies of pneumococci recovered from 37 nasopharyngeal (NP) samples of children. A total of 239 pneumococcal isolates (typically, six to eight colonies per sample) were typed by pulsed-field gel electrophoresis (PFGE). In most NP samples (89%) the multiple colonies shared common PFGE types and serotypes. However, four samples were heterogeneous (samples A through D): each contained two strains with different PFGE types, antibiotypes, and serotypes. Samples A and B each contained one strain of a vaccine capsular type and another expressing a non-vaccine type (according to the currently licensed seven-valent conjugate vaccine). In samples B and C the penicillin MIC for one strain was elevated and the other strain was susceptible. In each of the heterogeneous samples, one of the strains was a representative of an internationally disseminated clone. Samples A, C, and D contained strains which carried prophages that were inducible by mitomycin C and that could be visualized by electron microscopy. The
comC
gene allele (which encodes the competence-stimulating peptide) was the same in both strains found in each of samples A, B, and D. Carriage of multiple pneumococci with distinct properties should favor genetic exchange and provide a dynamic population structure for pneumococci in their ecological reservoir. Quantitative resolution of majority and minority components of the pneumococcal NP flora will be of importance for evaluation of the impact of intervention strategies such as vaccination or introduction of new antimicrobial agents.
Characterization of Multidrug-ResistantEscherichia coliIsolates Associated with Nosocomial Infections in Dogs
Authors: Sanchez Susan , McCrackin Stevenson M. A. , Hudson Charlene R. , Maier Marie , Buffington Tameka , Dam Quyen , Maurer John J. 
Published: September 2002

ABSTRACTMultidrug-resistant opportunistic pathogens have become endemic to the veterinary hospital environment.Escherichia coliisolates resistant to 12 antibiotics were isolated from two dogs that were housed in the intensive care unit at The University of Georgia Veterinary Teaching Hospital within 48 h of each other. Review of 21 retrospective and prospective hospital-acquiredE. coliinfections revealed that the isolates had similar antibiotic resistance profiles, characterized by resistance to most cephalosporins, β-lactams, and the β-lactamase inhibitor clavulanic acid as well as resistance to tetracycline, spectinomycin, sulfonamides, chloramphenicol, and gentamicin.E. coliisolates with similar resistance profiles were also isolated from the environment in the intensive care unit and surgery wards. MultipleE. coligenetic types were endemic to the hospital environment, with the pulsed-field gel electrophoresis fingerprint identified amongE. coliisolates from diseased animals and the hospital environment matching. The extended-spectrum cephalosporin resistance in these nosocomialE. coliisolates was attributed to the cephamycinase-encoding gene,blaCMY2. Chloramphenicol resistance was due in part to the dissemination of the florfenicol resistance gene,flo, among these isolates. Resistance encoded by both genes was self-transmissible. AlthoughblaCMY2andflowere common to the polyclonal, nosocomialE. coliisolates, there was considerable diversity in the genetic compositions of class 1 integrons, especially among isolates belonging to the same genetic type. Two or more integrons were generally present in these isolates. The gene cassettes present within each integron ranged in size from 0.6 to 2.4 kb, although a 1.7-kb gene cassette was the most prevalent. The 1.7-kb gene cassette contained spectinomycin resistance geneaadA5and trimethoprim resistance genedfrA17.