bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison and Evaluation of Osiris and Sirscan 2000 Antimicrobial Susceptibility Systems in the Clinical Microbiology Laboratory
Authors: Nijs A. , Cartuyvels R. , Mewis A. , Peeters V. , Rummens J. L. , Magerman K. 
Published: August 2003

ABSTRACT
The Osiris and Sirscan 2000 systems are two semiautomated systems that can be used to read and interpret the results on disk diffusion agar plates. They are both used for determination of susceptibility to antimicrobial agents. The present study compared both systems versus the NCCLS standard method of visual reading with a ruler. Both inpatient and outpatient samples with a total of 315 nonfastidious gram-negative strains were obtained. In total, 3,724 organism-antimicrobial agent combinations that fulfilled the NCCLS guidelines for disk diffusion susceptibility testing were evaluated prospectively. The results obtained with both systems in comparison with those obtained by the classical nonautomated means of interpretation were excellent, with correlation coefficients of 0.96 for both systems. The overall agreements for susceptibility interpretation were 96.56 and 96.24% with the Osiris and Sirscan systems, respectively. Very major errors were obtained for 8 (1.07%) and 10 (1.34%) organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. In addition, major errors were obtained for 2 (0.07%) and 6 (0.21%) combinations with the Osiris and Sirscan systems, respectively. Minor errors were obtained for 118 and 124 organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. Overall, both the Osiris system and the Sirscan system are comparable and reliable systems for determination of interpretative categories from the zone diameters of standard disk diffusion test plates.
Detection of Clarithromycin-Resistant
Helicobacter pylori
in Stool Samples
Authors: Fontana Carla , Favaro Marco , Pietroiusti Antonio , Pistoia Enrico Salvatore , Galante Alberto , Favalli Cartesio 
Published: August 2003

ABSTRACT

The recognition of the role of
Helicobacter pylori
in gastric diseases has led to the widespread use of antibiotics in the eradication of this pathogen. The most advocated therapy, triple therapy, often includes clarithromycin. It is well known that clarithromycin resistance is one of the major causes of eradication failure. The development of a rapid noninvasive technique that could easily be performed on fecal samples and that could also provide information about the antibiotic resistance of this microorganism is therefore advisable. Previous findings have demonstrated that clarithromycin resistance is due to a single point mutation in the 23S rRNA. All the mutations described have been associated with specific restriction sites, namely
Bsa
I (A2143G),
Mbo
II (A2142C/G), and
Hha
I (T2717C). On this basis we have developed a new method, a seminested PCR, allowing screening for clarithromycin resistance of
H. pylori
directly on stool samples. This method furnished a 783-bp fragment of the 23S rRNA, which was subsequently digested by
Mbo
II,
Bsa
I, and
Hha
I, in order to identify single point mutations associated with clarithromycin resistance. Of a total of 283 stool samples examined, 125 were
H. pylori
positive and two of them were shown to contain clarithromycin-resistant strains due to the presence of a mutation at position 2717, whereas no PCR products contained mutations at position 2142 or 2143. In order to evaluate the reliability of the new system, we compared the results of restriction analysis of the PCR products with the MICs shown by the
H. pylori
isolates by culturing gastric biopsies from the same patients.
Optimization and Validation of Multilocus Sequence Typing for
Candida albicans
Authors: Tavanti Arianna , Gow Neil A. R. , Senesi Sonia , Maiden Martin C. J. , Odds Frank C. 
Published: August 2003

ABSTRACT

Multilocus sequence typing (MLST) was applied to 75
Candida albicans
isolates, including 2 that were expected to be identical, 48 that came from diverse geographical and clinical sources, and 15 that were sequential isolates from two patients. DNA fragments (≈500 bp) of eight genes encoding housekeeping functions were sequenced, including four that have been described before for
C. albicans
MLST, and four new gene fragments,
AAT1a
,
AAT1b
,
MPI
, and
ZWF1
. In total, 87 polymorphic sites were found among 50 notionally different isolates, giving 46 unique sequence types, underlining the power of MLST to differentiate isolates for epidemiological studies. Additional typing information was obtained by detecting variations in size at the transcribed spacer region of the 25S rRNA gene and tests for homozygosity at the mating type-like (MTL) locus. The stability of MLST was confirmed in two sets of consecutive isolates from two patients. In each set the isolates were identical or varied by a single nucleotide. Reference strain SC5314 and a derived mutant, CAF2, gave identical MLST types. Heterozygous polymorphisms were found in at least one isolate for all but 16 (18.4%) of the variable nucleotides, and 35 (41%) of the 87 individual sequence changes generated nonsynonymous amino acids. Cloning and restriction digestion of a gene fragment containing heterozygous polymorphisms indicated that the heterozygosity was genuine and not the result of sequencing errors. Our data validate and extend previous MLST results for
C. albicans
, and we propose an optimized system based on sequencing eight gene fragments for routine MLST with this species.
Quantitative Real-Time PCR Assay for Detection of
Ehrlichia chaffeensis
Authors: Loftis Amanda D. , Massung Robert F. , Levin Michael L. 
Published: August 2003

ABSTRACT

A real-time PCR assay was developed for the detection of
Ehrlichia chaffeensis
. The assay is species specific and provides quantitative results in the range 10 to 10
10
gene copies. The assay is not inhibited by the presence of tick, human, or mouse DNA and is compatible with high sample throughput. The assay was compared with previously described assays for
E. chaffeensis
.
Identification ofExophiala mesophilaIsolated from Treated Dental Unit Waterlines
Authors: Porteous N. B. , Grooters A. M. , Redding S. W. , Thompson E. H. , Rinaldi M. G. , De Hoog G. S. , Sutton D. A. 
Published: August 2003

ABSTRACTMembers of the genusExophialaare often difficult to identify to the species level because of their variable morphological appearances. This paper describes the methods used to identifyExophiala mesophilaand provides salient differential features for distinguishing other mesophilic members of the genus.
A Twist-like bHLH gene is a downstream factor of an endogenous FGF and determines mesenchymal fate in the ascidian embryos
Authors: Imai Kaoru S. , Satoh Nori , Satou Yutaka 
Published: August 2003

Ascidian larvae develop mesenchyme cells in their trunk. A fibroblast growth factor (FGF9/16/20) is essential and sufficient for induction of the mesenchyme in Ciona savignyi. We have identified two basic helix-loop-helix (bHLH) genes named Twist-like1 and Twist-like2 as downstream factors of this FGF. These two genes are phylogenetically closely related to each other, and were expressed specifically in the mesenchymal cells after the 110-cell stage. Gene-knockdown experiments using a specific morpholino oligonucleotide demonstrated that Twist-like1 plays an essential role in determination of the mesenchyme and that Twist-like2 is a downstream factor of Twist-like1. In addition, both overexpression and misexpression of Twist-like1 converts non-mesenchymal cells to mesenchymal cells.We also demonstrate that the upstream regulatory mechanisms of Twist-like1 are different between B-line mesenchymal cells and the A-line mesenchymal cells called `trunk lateral cells'. FGF9/16/20 is required for the expression of Twist-like1 in B-line mesenchymal precursor cells, whereas FGF, FoxD and another novel bHLH factor called NoTrlc are required for Twist-like1 to be expressed in the A-line mesenchymal precursor cells. Therefore, two different but partially overlapping mechanisms are required for the expression of Twist-like1 in the mesenchymal precursors, which triggers the differentiation of the mesenchyme in Ciona embryos.
In‐situ near infrared spectroscopy to monitor key analytes in mammalian cell cultivation
Authors: Arnold S. Alison , Crowley John , Woods Nigel , Harvey Linda M. , McNeil Brian 
Published: August 2003

AbstractThe use of in‐situ near infrared spectroscopy (NIRS) as a tool for monitoring four key analytes in a CHO‐K1 animal cell culture was investigated. Previous work using on‐line NIRS to monitor bioprocesses has involved its application ex‐situ where the analyzer is physically outside the fermentor, or to microbial bioprocesses. This novel application of NIRS to monitor analytes within an animal cell culture using a steam sterilizable in‐situ fiber optic probe is very important for furthering the use of NIRS within the bioprocessing industry. The method of calibration used to develop the models involved the use of large data sets so that all likely variation in stoichiometry was incorporated within the models. Successful models for glucose, lactate, glutamine, and ammonia were built with Standard Error of Predictions (SEP's) of 0.072 (g/L), 0.0144 (g/L), 0.308 (mM), and 0.036 (mM), respectively of the total concentration range. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 13–19, 2003.
Long‐term continuous evolution of acetate resistant Acetobacter aceti
Authors: Steiner Peter , Sauer Uwe 
Published: August 2003

AbstractElevated concentrations of cytotoxic acetate are found in many environmental niches, and few species are relatively resistant to acetate. In particular the high‐level acetate resistance of so‐called acetic acid bacteria that occurs in industrial settings must be constantly selected for. To investigate the nature of such high‐level resistance, we grew the moderately acetate‐resistant Acetobacter aceti wild‐type and acetate‐sensitive Escherichia coli in long‐term continuous cultures with increasing acetate concentrations at near neutral pH. While E. coli did not acquire any significant resistance after 125 generations of selection, A. aceti evolved the capability to grow at acetate concentrations exceeding 50 g/L within 240 generations. This phenotype was found to be stable for several generations in the absence of selective pressure, hence must be genetically determined. Intracellular acetate concentrations were significantly lower in evolved A. aceti, when compared to wild‐type A. aceti and E. coli, indicating that cytoplasmatic anion accumulation is an important component of acetate toxicity. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 40–44, 2003.
Fiscal instruments in sustainable housing policies in the EU and the accession countries
Authors: Sunikka Minna 
Published: August 2003

AbstractAlthough progressive government guidelines and knowledge about sustainable housing exist, progress in implementing them in practice has been slow. The perceived costs and the lack of market demand have been identified as the main barriers. A choice of fiscal instruments is essential in sustainable housing policies. This article presents an analysis of economic measures currently used to support sustainable housing in the EU and the accession countries, indicating the areas where policy instruments are either focused or lacking. Based on the country progress reports of the Third European Ministers Conference on Sustainable Housing in Belgium in 2002, the results indicate that environmental taxes and subsidies are used in the EU and the accession countries, but that they have had a low impact on the housing sector. An examination of the developments since 1996 shows that apart from energy initiatives resulting from the Kyoto Protocol, the lack of a strong driving force has kept progress slow. Conclusions are based on the analysis findings – the low impact of taxation on housing, the lack of environmental criteria in the reduced VAT rate and the narrow focus of subsidies. This article argues that enlargement of the EU presents opportunities for sustainable housing in Europe, if the fiscal instruments are enforced by legal means. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Runoff production processes in small alpine catchments within the unconsolidated Pleistocene sediments of the Lainbach area (Upper Bavaria)
Authors: Wetzel Karl‐Friedrich 
Published: August 2003

AbstractIn the Lainbach catchment, unconsolidated Pleistocene moraine sediments are widely distributed. Because of the great natural risk of floods, together with extreme loads of sediments, investigations of runoff production processes have been conducted in this area. At hillslope scale three test sites with different states of soil development and vegetation cover were instrumented with V‐shaped weirs, precipitation gauges and measurement devices for electrical conductivity (EC) of discharge water. The EC has been used as a geochemical tracer for hydrograph separation, since the statistical relationship between content of dissolved Ca2+, Mg2+ cations and EC is highly significant for different stages of runoff. This method allows hydrograph separation at high temporal resolution for both the rising and falling limb of the hydrograph. The following results of the investigations can be resumed. If relief conditions are similar, the effectiveness of runoff production decreases with an increasing density of vegetation cover. The runoff delivery ratio decreases as well as the peaks of runoff. In contrast, concentration times of hillslope catchments are equal, even if vegetation cover is of great density and soils are well developed. As a reason for the short reaction times, different runoff production processes have been detected. On bare ground, infiltration excess overland flow intensified by surface sealing processes is the main source for quick runoff. On hillslopes well covered by vegetation, translatory flow processes indicated by soil water with high solute contents force a rapid runoff reaction only a few minutes after rainfall has begun. It is to be assumed that translatory flow is a runoff production process typical for hillslopes covered by vegetation in a steep alpine relief. By means of the areal distribution of the topographic index, concentration of runoff production on a small part of the catchment has been demonstrated for hillslopes densely covered by vegetation. The investigations have shown that there is a lack of studies on runoff production processes in steep alpine relief, as well as a deficit of methods to quantify hydraulic properties of coarse‐grained soils with a wide grain size distribution. Copyright © 2003 John Wiley & Sons, Ltd.
A dynamically gain‐flattened erbium‐doped fiber amplifier
Authors: Lu Z. G. , Lin P. , Grover C. P. 
Published: August 2003

AbstractThis paper reports on dynamically gain‐flattened C‐ and L‐band erbium‐doped fiber amplifiers (DGF‐EDFAs), whose dynamic gain ranges are above 20 dB and 24 dB, respectively. This paper gives the detailed test and comparative results for DGF‐EDFAs based on the use of a voltage‐controlled fiber‐based gain tilt controller and a variable optical attenuator. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 8–11, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11110
Satellite communication with moving vehicles on earth: Two prototype circular array antennas
Authors: Ares F. , Franceschetti G. , Mosig J. , Vaccaro S. , Vassal'lo J. , Moreno E. 
Published: August 2003

AbstractThe performance of two minimal prototype antennas validates a novel design concept for a vehicle‐borne antenna for communications via satellite: the toroidal beam antenna implemented by a ring or rings of microstrip patches. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 14–16, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11112
A wideband coplanar‐waveguide‐fed multi‐slot antenna for radar applications
Authors: Allen Cuthbert M. , Eldek Abdelnasser A. , Elsherbeni Atef Z. , Smith Charles E. 
Published: August 2003

AbstractA small multi‐slot antenna is designed for RF and microwave sensors and radar applications. The design was realized using a series of parallel slots with tapered lengths, fed by a coplanar waveguide (CPW) to support wideband operation. The designed multi‐slot antenna provides a 50% bandwidth centered at 10 GHz with 50Ω input impedance. The operating bandwidth remains almost constant regardless of the length of the feeding mechanism. This feature is demonstrated by several numerical simulations. Return loss, input impedance, radiation pattern, gain, and efficiency of the proposed design are computed and analyzed to support X‐band operation. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 24–27, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11116
Demonstration of an all‐optical logic OR gate using gain saturation in an SOA
Authors: Hamie Ali , Sharaiha Ammar , Guegan Mikael 
Published: August 2003

AbstractIn this paper, the all‐optical realization of a logic OR gate using gain saturation in a standard semiconductor optical amplifier (SOA) is successfully experimentally demonstrated. This reported feasibility study shows the all‐optical OR function can be easily achieved with an extinction ratio of about 7 dB. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 39–42, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11120
A new type of slotted waveguide and moving couplers for shielded microwave transfer
Authors: Sommavilla Diego , Liess Martin , Leyten Lukas 
Published: August 2003

AbstractWe present a novel small coaxial broadband slotted waveguide that can be used where size is a critical factor. We further present adapted directional and bidirectional wave couplers that can be introduced into the waveguide to launch and detect signals. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 42–44, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11121
A fully integrated concurrent dual‐band CMOS low‐noise amplifier
Authors: Zhang Y. P. , Chew K. W. , Wong P. F. , Do M. A. 
Published: August 2003

AbstractThis paper presents a fully integrated concurrent dual‐band CMOS low‐noise amplifier (LNA). The LNA is implemented in a standard 0.18‐μm 6M1P CMOS process and is designed from the system viewpoint to provide higher gain at the higher band, for the first time, to compensate the higher‐band signal's extra loss over the air transmission. The LNA drains 5.3 mA of current from a 1.8‐V supply voltage and achieves voltage gains of 16 and 22.5 dB, input return losses of 28 and 27 dB, and noise figures of 3.0 and 3.1 dB at 2.4 and 5.2 GHz, respectively. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 52–53, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11124
Ga0.51In0.49P/InxGa1−xAs/GaAs doped‐channel FETs (DCFETs) and their applications on monolithic microwave integrated circuits (MMICs)
Authors: Lin Yo‐Sheng , Chen Chih‐Chen , Lu Shey‐Shi 
Published: August 2003

AbstractIn this paper, lattice‐matched Ga0.51In0.49P/GaAs and strained Ga0.51In0.49P/In0.2Ga0.8As doped‐channel FETs (DCFETs) were investigated in terms of DC and microwave performances, including frequency response, noise figure, power‐added efficiency (PAE), and output power. In addition, small‐signal and large‐signal models were created for designing monolithic microwave integrated circuits (MMICs). The heterostructures were both grown by gas‐source molecular beam epitaxy (GSMBE) on semi‐insulating (100) GaAs substrates. In situ reflection high‐energy electron diffraction (RHEED) was used to calibrate the growth rate of InP and GaP. Because of the high etching selectivity between Ga0.51In0.49P and In0.2Ga0.8As/GaAs, the uniformity of the measured electrical properties of our fabricated devices is quite satisfying, which indicates that these Ga0.51In0.49P/InxGa1−xAs structures are very suitable for mass production. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 56–62, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11126
1H, 13C and 15N NMR spectroscopic, x‐ray structural and ab initio/HF studies on nitramino and N‐alkylamino‐4‐nitro derivatives of pyridine N‐oxides and pyridines
Authors: Laihia Katri , Kolehmainen Erkki , Virtanen Elina , Nissinen Maija , Puszko Aniela , Talik Zofia 
Published: August 2003

AbstractThe 1H, 13C and 15N NMR spectra in DMSO‐d6 were measured for eight nitraminopyridine N‐oxides, ten 4‐nitropyridine N‐oxides, four 2‐nitraminopyridines and five 4‐nitropyridines. Their chemical shift assignments are based on PFG 1H,X (X = 13C and 15N) HMQC and HMBC experiments. The relative energies for the tautomers of two nitraminopyridine N‐oxides were determined by ab initio HF/6–311G** calculations. A single‐crystal x‐ray structural analysis was made for 4‐methyl‐2‐nitraminopyridine: C6H7O2N3, M = 153.15, triclinic, space group P‐1 (No. 2), a = 7.0275(4), b = 6.8034(3), c = 8.6086(5) Å, α = 103.620(2), β = 90.309(2), γ = 122.215(3)°, V = 334.11(3) Å3, Z = 2. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of the 1H and 13C NMR spectra of bicyclo[6.2.1]undecane ring systems
Authors: Gomes Constantino Mauricio , Thiago de Oliveira Kleber , Beatriz Adilson , José da Silva Gil Valdo 
Published: August 2003

AbstractA detailed NMR analysis with full assignment of the 1H and 13C spectral data for two polycyclic compounds is described. These compounds are derivatives of the product obtained from the pericyclic reaction between cyclopentadiene and tropone. Peculiar intriguing conformational features of these molecules are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Assessing the potential of fast amplitude modulation pulses for improving triple‐quantum magic angle spinning NMR spectra of half‐integer quadrupolar nuclei
Authors: Morais C. M. , Lopes M. , Fernandez C. , Rocha J. 
Published: August 2003

AbstractA comprehensive experimental and numerical study of the potential of fast amplitude (FAM) irradiation for improving the triple‐quantum (3Q) magic angle spinning (MAS) NMR spectra of half‐integer $I > {1 \over 2}$ nuclei (23Na, 27Al, 45Sc, 93Nb) was carried out. Materials of academic and industrial importance, such as infrared‐emitter Na3YSi3O9, microporous aluminophosphate VPI‐5, mineral andalusite, calcined kaolinite, Sc2O3 and relaxor ferroelectric PMN, were investigated. It was found that FAM pulses are indeed of practical relevance and particularly useful for the observation of the NMR resonances given by nuclei in distorted local environments (large quadrupole coupling constants). In addition, a novel strategy for the optimization of the FAM‐II MQ MAS NMR experiment, which improves the multiple‐ to single‐quantum coherence transfer efficiency, is also reported. Copyright © 2003 John Wiley & Sons, Ltd.