bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Improvement of Calibration Coefficients for Hole-Drilling Integral Method: Part I—Analysis of Calibration Coefficients Obtained by a 3-D FEM Model
Authors: Aoh Jong-Ning , Wei Chung-Sheng 
Published: July 2002

AbstractOne of the important factors affecting the accuracy of stress values obtained from the hole-drilling method is the calibration coefficient. A three-dimensional model was established to determine the calibration coefficients for integral method. The constraint conditions and loading conditions during hole-drilling can be simulated more realistically with this method. With this new model, coefficients a¯i,j and b¯i,j could be determined within one computation procedure. The relationship between calibration coefficients and plate thickness was investigated over a wide range of plate thickness. It has been found that the calibration coefficients determined in this work may vary with thickness of plates and the thickness range for thin plates was thus well defined. The calibration coefficients can thus be extended to measure the residual stresses of either thin or thick plates. Comparison of calibration coefficients with those determined by other studies was also conducted.
Optimization Design of Drawbead in Drawing Tools of Autobody Cover
Panel
Authors: Liu Gang , Lin Zhongqin , Bao Youxia 
Published: July 2002

Abstract
In the tooling design of autobody cover panels, design of drawbead will affect the distribution of drawing restraining force along mouth of dies and the relative flowing velocity of the blank, and consequently, will affect the distributions of strain and thickness in a formed part. Therefore, reasonable design of drawbead is the key point of cover panels’ forming quality. An optimization design method of drawbead, using one improved hybrid optimization algorithm combined with FEM software, is proposed in this paper. First, we used this method to design the distribution of drawbead restraining force along the mouth of a die, then the actual type and geometrical parameters of drawbead could be obtained according to an improved drawbead restraining force model and the improved hybrid optimization algorithm. This optimization method of drawbead was used in designing drawing tools of an actual autobody cover panel, and an optimized drawbead design plan has been obtained, by which deformation redundancy was increased from 0% under uniform drawbead control to 10%. Plastic strain of all area of formed part was larger than 2% and the minimum flange width was larger than 10 mm. Therefore, not only better formability and high dent resistance were obtained, but also fine cutting contour line and high assembly quality could be obtained. An actual drawing part has been formed using the optimized drawbead, and the experimental results were compared with the simulating results in order to verify the validity of the optimized design plan. Good agreement of thickness on critical areas between experimental results and simulation results proves that the optimization design method of drawbead could be successfully applied in designing actual tools of autobody cover panels.
Distribution of Lipid Formulations of Amphotericin B into Bone Marrow and Fat Tissue in Rabbits
Authors: Groll Andreas H. , Mickiene Diana , Piscitelli Stephen C. , Walsh Thomas J. 
Published: July 2002

ABSTRACT
The distribution of the three currently available lipid formulations of amphotericin B (AmB) into bone marrow and fat tissue was evaluated in noninfected rabbits. Groups of four animals each received either 1 mg of AmB deoxycholate (D-AmB) per kg of body weight per day or 5 mg of AmB colloidal dispersion, AmB lipid complex, or liposomal AmB per kg per day for seven doses. Plasma, bone marrow, fat, and liver were collected at autopsy, and AmB concentrations were determined by high-performance liquid chromatography. At the investigated dosages of 5 mg/kg/day, all AmB lipid formulations achieved at least fourfold-higher concentrations in bone marrow than did standard D-AmB at a dosage of 1 mg/kg/day. Concentrations in bone marrow were 62 to 76% of concurrent AmB concentrations in the liver. In contrast, all AmB formulations accumulated comparatively poorly in fat tissue. The results of this study show that high concentrations of AmB can be achieved in the bone marrow after administration of lipid formulations, suggesting their particular usefulness against disseminated fungal infections involving the bone marrow and against visceral leishmaniasis.
Novel α- and β-Amino Acid Inhibitors of Influenza Virus Neuraminidase
Authors: Kati Warren M. , Montgomery Debra , Maring Clarence , Stoll Vincent S. , Giranda Vincent , Chen Xiaoqi , Laver W. Graeme , Kohlbrenner William , Norbeck Daniel W. 
Published: July 2002

ABSTRACT

In an effort to discover novel, noncarbohydrate inhibitors of influenza virus neuraminidase we hypothesized that compounds which contain positively charged amino groups in an appropriate position to interact with the Asp 152 or Tyr 406 side chains might be bound tightly by the enzyme. Testing of 300 α- and β-amino acids led to the discovery of two novel neuraminidase inhibitors, a phenylglycine and a pyrrolidine, which exhibited
K

i

values in the 50 μM range versus influenza virus A/N2/Tokyo/3/67 neuraminidase but which exhibited weaker activity against influenza virus B/Memphis/3/89 neuraminidase. Limited optimization of the pyrrolidine series resulted in a compound which was about 24-fold more potent than 2-deoxy-2,3-dehydro-
N
-acetylneuraminic acid in an anti-influenza cell culture assay using A/N2/Victoria/3/75 virus. X-ray structural studies of A/N9 neuraminidase-inhibitor complexes revealed that both classes of inhibitors induced the Glu 278 side chain to undergo a small conformational change, but these compounds did not show time-dependent inhibition. Crystallography also established that the α-amino group of the phenylglycine formed hydrogen bonds to the Asp 152 carboxylate as expected. Likewise, the β-amino group of the pyrrolidine forms an interaction with the Tyr 406 hydroxyl group and represents the first compound known to make an interaction with this absolutely conserved residue. Phenylglycine and pyrrolidine analogs in which the α- or β-amino groups were replaced with hydroxyl groups were 365- and 2,600-fold weaker inhibitors, respectively. These results underscore the importance of the amino group interactions with the Asp 152 and Tyr 406 side chains and have implications for anti-influenza drug design.
Low Sensitivity of
Listeria monocytogenes
to Quaternary Ammonium Compounds
Authors: Mereghetti L. , Quentin R. , Marquet-Van Der Mee N. , Audurier A. 
Published: July 2002

ABSTRACT

Ninety-seven epidemiologically unrelated strains of
Listeria monocytogenes
were investigated for their sensitivities to quaternary ammonium compounds (benzalkonium chloride and cetrimide). The MICs for seven serogroup 1/2 strains were high. Three came from the environment and four came from food; none were isolated from human or animal samples. All 97 strains carried the
mdrL
gene, which encodes a multidrug efflux pump, and the
orfA
gene, a putative transcriptional repressor of
mdrL
. The absence of plasmids in four of the seven resistant strains and the conservation of resistance after plasmid curing suggested that the resistance genes are not plasmid borne. Moreover, PCR amplification and Southern blot hybridization experiments failed to find genes phylogenetically related to the
qacA
and
smr
genes, encoding multidrug efflux systems previously described for the genus
Staphylococcus
. The high association between nontypeability by phages and the loss of sensitivity to quaternary ammonium compounds are suggestive of an intrinsic resistance due to modifications in the cell wall.
Homoduplex and Heteroduplex Polymorphisms of the Amplified Ribosomal 16S-23S Internal Transcribed Spacers Describe Genetic Relationships in the “
Bacillus cereus
Group”
Authors: Daffonchio Daniele , Cherif Ameur , Borin Sara 
Published: July 2002

ABSTRACT

Bacillus anthracis
,
Bacillus cereus
,
Bacillus mycoides
,
Bacillus pseudomycoides
,
Bacillus thuringiensis
, and
Bacillus weihenstephanensis
are closely related in phenotype and genotype, and their genetic relationship is still open to debate. The present work uses amplified 16S-23S internal transcribed spacers (ITS) to discriminate between the strains and species and to describe the genetic relationships within the “
B. cereus
group,” advantage being taken of homoduplex-heteroduplex polymorphisms (HHP) resolved by polyacrylamide gel electrophoresis and silver staining. One hundred forty-one strains belonging to the six species were investigated, and 73 ITS-HHP pattern types were distinguished by MDE, a polyacrylamide matrix specifically designed to resolve heteroduplex and single-strand conformation polymorphisms. The discriminating bands were confirmed as ITS by Southern hybridization, and the homoduplex or heteroduplex nature was identified by single-stranded DNA mung bean nuclease digestion. Several of the ITS-HHP types corresponded to specific phenotypes such as
B. anthracis
or serotypes of
B. thuringiensis
. Unweighted pair group method arithmetic average cluster analysis revealed two main groups. One included
B. mycoides
,
B. weihenstephanensis
, and
B. pseudomycoides
. The second included
B. cereus
and
B. thuringiensis
,
B. anthracis
appeared as a lineage of
B. cereus
.
Molecular Mating Type Assay for
Fusarium circinatum
Authors: Wallace M. Margaret , Covert Sarah F. 
Published: July 2002

ABSTRACT

A rapid and reliable mating type assay for
Fusarium circinatum
was created by applying primers specific for the
MAT1-1
and
MAT1-2
mating type alleles to genomic DNA in a single PCR. A similar approach may be applied to fungi not previously shown to reproduce sexually, thus enabling studies of population structure and inheritance.
Molecular Cloning, Sequencing, and Expression of
omp-40
, the Gene Coding for the Major Outer Membrane Protein from the Acidophilic Bacterium
Thiobacillus ferrooxidans
Authors: Guiliani Nicolas , Jerez Carlos A. 
Published: July 2002

ABSTRACT

Thiobacillus ferrooxidans
is one of the chemolithoautotrophic bacteria important in industrial biomining operations. Some of the surface components of this microorganism are probably involved in adaptation to their acidic environment and in bacterium-mineral interactions. We have isolated and characterized
omp40
, the gene coding for the major outer membrane protein from
T. ferrooxidans
. The deduced amino acid sequence of the Omp40 protein has 382 amino acids and a calculated molecular weight of 40,095.7. Omp40 forms an oligomeric structure of about 120 kDa that dissociates into the monomer (40 kDa) by heating in the presence of sodium dodecyl sulfate. The degree of identity of Omp40 amino acid sequence to porins from enterobacteria was only 22%. Nevertheless, multiple alignments of this sequence with those from several OmpC porins showed several important features conserved in the
T. ferrooxidans
surface protein, such as the approximate locations of 16 transmembrane beta strands, eight loops, including a large external L3 loop, and eight turns which allowed us to propose a putative 16-stranded beta-barrel porin structure for the protein. These results together with the previously known capacity of Omp40 to form ion channels in planar lipid bilayers strongly support its role as a porin in this chemolithoautotrophic acidophilic microorganism. Some characteristics of the Omp40 protein, such as the presence of a putative L3 loop with an estimated isoelectric point of 7.21 allow us to speculate that this can be the result of an adaptation of the acidophilic
T. ferrooxidans
to prevent free movement of protons across its outer membrane.
Temperature Affects Species Distribution in Symbiotic Populations of
Vibrio
spp
Authors: Nishiguchi Michele K. 
Published: July 2002

ABSTRACT

The genus
Sepiola
(Cephalopoda: Sepiolidae) contains 10 known species that occur in the Mediterranean Sea today. All
Sepiola
species have a light organ that contains at least one of two species of luminous bacteria,
Vibrio fischeri
and
Vibrio logei
. The two
Vibrio
species coexist in at least four
Sepiola
species (
S. affinis
,
S. intermedia
,
S. ligulata
, and
S. robusta
), and their concentrations in the light organ depend on changes in certain abiotic factors, including temperature. Strains of
V. fischeri
grew faster in vitro and in
Sepiola
juveniles when they were incubated at 26°C. In contrast, strains of
V. logei
grew faster at 18°C in culture and in
Sepiola
juveniles. When aposymbiotic
S. affinis
or
S. ligulata
juveniles were inoculated with one
Vibrio
species, all strains of
V. fischeri
and
V. logei
were capable of infecting both squid species at the optimum growth temperatures, regardless of the squid host from which the bacteria were initially isolated. However, when two different strains of
V. fischeri
and
V. logei
were placed in direct competition with each other at either 18 or 26°C, strains of
V. fischeri
were present in sepiolid light organs in greater concentrations at 26°C, whereas strains of
V. logei
were present in greater concentrations at 18°C. In addition to the competition experiments, the ratios of the two bacterial species in adult
Sepiola
specimens caught throughout the season at various depths differed, and these differences were correlated with the temperature in the surrounding environment. My findings contribute additional data concerning the ecological and environmental factors that affect host-symbiont recognition and may provide insight into the evolution of animal-bacterium specificity.
Development of a Fluorogenic 5′ Nuclease PCR Assay for Detection of the
ail
Gene of Pathogenic
Yersinia enterocolitica
Authors: Jourdan Alissa D. , Johnson Scott C. , Wesley Irene V. 
Published: July 2002

ABSTRACT

In this report we describe the development and evaluation of a fluorogenic PCR assay for the detection of pathogenic
Yersinia enterocolitica
. The assay targets the chromosomally encoded attachment and invasion gene,
ail
. Three primer-probe sets (TM1, TM2, and TM3) amplifying different, yet overlapping, regions of
ail
were examined for their specificity and sensitivity. All three primer-probe sets were able to detect between 0.25 and 0.5 pg of purified
Y. enterocolitica
DNA. TM1 identified all 26
Y. enterocolitica
strains examined. TM3 was able to detect all strains except one, whereas TM2 was unable to detect 10 of the
Y. enterocolitica
strains tested. None of the primer-probe sets cross-reacted with any of the 21 non-
Y. enterocolitica
strains examined. When the TM1 set was utilized, the fluorogenic PCR assay was able to detect ≤4
Y. enterocolitica
CFU/ml in pure culture and 10
Y. enterocolitica
CFU/ml independent of the presence of 10
8
CFU of contaminating bacteria per ml. This set was also capable of detecting ≤1 CFU of
Y. enterocolitica
per g of ground pork or feces after a 24-h enrichment in a
Yersinia
selective broth.
Inactivation of Viable
Ascaris
Eggs by Reagents during Enumeration
Authors: Nelson Kara L. , Darby Jeannie L. 
Published: July 2002

ABSTRACT

Various reagents commonly used to enumerate viable helminth eggs from wastewater and sludge were evaluated for their potential to inactivate
Ascaris
eggs under typical laboratory conditions. Two methods were used to enumerate indigenous
Ascaris
eggs from sludge samples. All steps in the methods were the same except that in method I a phase extraction step with acid-alcohol (35% ethanol in 0.1 N H
2
SO
4
) and diethyl ether was used whereas in method II the extraction step was avoided by pouring the sample through a 38-μm-mesh stainless steel sieve that retained the eggs. The concentration of eggs and their viability were lower in the samples processed by method I than in the samples processed by method II by an average of 48 and 70%, respectively. A second set of experiments was performed using pure solutions of
Ascaris suum
eggs to elucidate the effect of the individual reagents and relevant combination of reagents on the eggs. The percentages of viable eggs in samples treated with acid-alcohol alone and in combination with diethyl ether or ethyl acetate were 52, 27, and 4%, respectively, whereas in the rest of the samples the viability was about 80%. Neither the acid nor the diethyl ether alone caused any decrease in egg viability. Thus, the observed inactivation was attributed primarily to the 35% ethanol content of the acid-alcohol solution. Inactivation of the eggs was prevented by limiting the direct exposure to the extraction reagents to 30 min and diluting the residual concentration of acid-alcohol in the sample by a factor of 100 before incubation. Also, the viability of the eggs was maintained if the acid-alcohol solution was replaced with an acetoacetic buffer. None of the reagents used for the flotation step of the sample cleaning procedure (ZnSO
4
, MgSO
4
, and NaCl) or during incubation (0.1 N H
2
SO
4
and 0.5% formalin) inactivated the
Ascaris
eggs under the conditions studied.
Concentration and Detection of
Cryptosporidium
Oocysts in Surface Water Samples by Method 1622 Using Ultrafiltration and Capsule Filtration
Authors: Simmons Otto D. , Sobsey Mark D. , Heaney Christopher D. , Schaefer Frank W. , Francy Donna S. 
Published: July 2002

ABSTRACT

The protozoan parasite
Cryptosporidium parvum
is known to occur widely in both source and drinking water and has caused waterborne outbreaks of gastroenteritis. To improve monitoring, the U.S. Environmental Protection Agency developed method 1622 for isolation and detection of
Cryptosporidium
oocysts in water. Method 1622 is performance based and involves filtration, concentration, immunomagnetic separation, fluorescent-antibody staining and 4′,6-diamidino-2-phenylindole (DAPI) counterstaining, and microscopic evaluation. The capsule filter system currently recommended for method 1622 was compared to a hollow-fiber ultrafilter system for primary concentration of
C. parvum
oocysts in seeded reagent water and untreated surface waters. Samples were otherwise processed according to method 1622. Rates of
C. parvum
oocyst recovery from seeded 10-liter volumes of reagent water in precision and recovery experiments with filter pairs were 42% (standard deviation [SD], 24%) and 46% (SD, 18%) for hollow-fiber ultrafilters and capsule filters, respectively. Mean oocyst recovery rates in experiments testing both filters on seeded surface water samples were 42% (SD, 27%) and 15% (SD, 12%) for hollow-fiber ultrafilters and capsule filters, respectively. Although
C. parvum
oocysts were recovered from surface waters by using the approved filter of method 1622, the recovery rates were significantly lower and more variable than those from reagent grade water. In contrast, the disposable hollow-fiber ultrafilter system was compatible with subsequent method 1622 processing steps, and it recovered
C. parvum
oocysts from seeded surface waters with significantly greater efficiency and reliability than the filter suggested for use in the version of method 1622 tested.
Anti-CagA Immunoglobulin G Responses Correlate with Interleukin-8 Induction in Human Gastric Mucosal Biopsy Culture
Authors: Ando Takafumi , Perez-Perez Guillermo I. , Kusugami Kazuo , Ohsuga Masahiro , Bloch Karen C. , Blaser Martin J. 
Published: July 2002

ABSTRACTHelicobacter pyloripersists in the human stomach despite eliciting both cellular and humoral immune responses and inducing proinflammatory cytokines. To determine whether local humoral and cytokine responses are related to each other and to histologic responses, we studied 66 Japanese patients who underwent gastroscopy. Using specific enzyme-linked immunosorbent assays, we examined gastric antral mucosal-organ biopsy culture supernatants to assess interleukin-6 (IL-6) and interleukin-8 (IL-8) levels and antibody responses toH. pyloriwhole-cell antigens CagA, HspA, and HspB. Of the patients studied, 11 wereH. pylorinegative and 55 wereH. pyloripositive; by PCR, all strains werecagA+. As expected, compared toH. pylori-negative patients,H. pylori-positive patients had significantly higher humoral responses to allH. pyloriantigens and had higher IL-8 (47.8 ± 3.5 versus 10.1 ± 4.3 ng/mg of biopsy protein;P< 0.001) and IL-6 levels (2.8 ± 0.3 versus 0.26 ± 0.2 ng/mg of protein;P< 0.001). Among theH. pylori-positive patients, supernatant anti-CagA immunoglobulin G (IgG) levels were significantly associated withH. pyloridensity (P< 0.005) and neutrophil infiltration (P< 0.005) scores. Anti-CagA immunoglobulin A levels were correlated with intestinal metaplasia (P< 0.05). Mononuclear cell infiltration scores were significantly associated with supernatant IL-6 levels (P< 0.005) and with IgG responses to whole-cell antigens (P< 0.05). Supernatant IL-8 levels were significantly associated with anti-CagA IgG (r= 0.75,P< 0.001). Anti-CagA responses correlated with neutrophil infiltration, intestinal metaplasia,H. pyloridensity, and IL-8 levels, suggesting that the absolute levels of these antibodies may be markers for gastric inflammation and premalignant changes in individual hosts.
CpG Oligodeoxynucleotides Act as Adjuvants for Pneumococcal Polysaccharide-Protein Conjugate Vaccines and Enhance Antipolysaccharide Immunoglobulin G2a (IgG2a) and IgG3 Antibodies
Authors: Chu Rose S. , McCool Tera , Greenspan Neil S. , Schreiber John R. , Harding Clifford V. 
Published: July 2002

ABSTRACTPneumococcal polysaccharide-protein conjugate vaccines elicit antipolysaccharide antibodies, but multiple doses are required to achieve protective antibody levels in children. In addition, the immunogenicity of experimental multivalent pneumococcal conjugate vaccines varies with different polysaccharide serotypes. One strategy to improve these vaccines is to incorporate an adjuvant to enhance their immunogenicity. Synthetic oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODN) are adjuvants that promote T-cell and T-dependent antibody responses to protein antigens, but it has been unclear whether CpG ODN can enhance polysaccharide-specific antibody responses. The present studies demonstrate significant adjuvant activity of CpG ODN for antibody responses againstStreptococcus pneumoniaepolysaccharide types 19F and 6B induced by conjugates of 19F and 6B with the protein carrier CRM197. BALB/c ByJ mice were injected with 19F-CRM197or 6B-CRM197with or without CpG ODN, and sera were tested for anti-19F or anti-6B antibodies by enzyme-linked immunosorbent assay. The polysaccharide-specific antibody response to 19F-CRM197alone was predominantly of the immunoglobulin G1 (IgG1) and IgM isotypes, but addition of CpG ODN markedly increased geometric mean titers of total anti-19F antibody (23-fold), anti-19F IgG2a (26-fold), and anti-19F IgG3 (>246-fold). The polysaccharide-specific antibody response to 6B-CRM197alone consisted only of IgM, but addition of CpG ODN induced high titers of anti-6B IgG1 (>78-fold increase), anti-6B IgG2a (>54-fold increase), and anti-6B IgG3 (>3,162-fold increase). CpG ODN also increased anti-CRM197IgG2a and IgG3. Adjuvant effects were not observed with control non-CpG ODN. Thus, CpG ODN significantly enhance antipolysaccharide IgG responses (especially IgG2a and IgG3) induced by these glycoconjugate vaccines.