bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐voltage contactless conductivity detection of underivatized amino acids in capillary electrophoresis
Authors: Tanyanyiwa Jatisai , Schweizer Karin , Hauser Peter C. 
Published: July 2003

AbstractHigh‐voltage contactless conductivity detection of underivatized amino acids in both acidic and basic media is demonstrated. The suitability of different acidic buffer solutions at pH values of about 2.5 was investigated with 12 amino acids. Lactic acid as background electrolyte gave the best results in terms of detection limits for arginine, lysine and histidine, which were approximately 2×10‐7, 3×10‐7 and 4×10‐7 M, respectively. However, the sensitivity for other species was not quite as good and the detection limits in the order of 0.5–1×10 ‐5 M. The use of basic conditions at pH 10–11 generally led to more stable baselines and more consistent sensitivities. A range of 20 amino acids was investigated with alkaline buffers and detection limits were typically about 10‐6 M. Urine and beer samples were analyzed. Nine and eleven amino acids could be identified, respectively.
Peptide separation in hydrophilic interaction capillary electrochromatography
Authors: Fu Hongjing , Jin Wenhai , Xiao Hua , Huang Haiwei , Zou Hanfa 
Published: July 2003

AbstractSeparation of small peptides by hydrophilic interaction capillary electrochromatography (HI‐CEC) has been investigated. The negative surface charge of a hydrophilic, strong‐cation‐exchange stationary phase (PolySULFOETHYL A) provided a substantial cathodic electroosmotic flow (EOF). The influence of acetonitrile content, ionic strength, mobile phase pH as well as applied voltage on the migration of the peptides was studied. Possible retention mechanisms of the peptides in HI‐CEC were discussed. It was found that hydrophilic interaction between the solutes and the stationary phase played a major role in this system, especially when mobile phases with high acetonitrile content were used. However, an ion‐exchange mechanism and electrophoretic mobility also affect the migration of the peptides in HI‐CEC. Elution order and selectivity was proved to be different in HI‐CEC and capillary zone electrophoresis (CZE), thus revealing the potential of HI‐CEC as a complementary technique to CZE for the separation of peptides. Efficiency and selectivity of HI‐CEC for the separation of peptides were demonstrated by baseline separating nine peptides in 6 min.
Frequency of C3435T single nucleotide MDR1 genetic polymorphism in an Asian population: phenotypic–genotypic correlates
Authors: Balram C. , Sharma A. , Sivathasan C. , Lee Edmund J. D. 
Published: July 2003

Aims  To investigate the frequency of the single nucleotide polymorphism C3435T in exon 26 of the MDR1 gene in Asians and to determine the functional significance of this SNP with the clinical pharmacokinetics of oral cyclosporin (Neoral) in 10 stable heart transplant patients.Methods  The MDR1 C3435T polymorphism was investigated in 290 healthy Asian subjects (98 Chinese, 99 Malays and 93 Indians). We also compared the MDR1 polymorphism between the Asian population studied here and the published data on Africans and Caucasians. The clinical relevance of this SNP on oral bioavailability of a known P‐gp substrate, cyclosporin, was assessed in 10 stable Chinese heart transplant patients.Results  The homozygous TT genotype was observed in 32%, 28% and 43% of Chinese, Malays and Indians. The homozygous CC genotype was found in 25% of Chinese and Malays compared with 18% of Indians. The Indians had a lower frequency of the C allele [0.38 (0.31–0.45)] compared with the Chinese [0.46 (0.39–0.53)] and Malays [0.48 (0.42–0.55)]. Chi‐squared test showed that the distribution of allele frequencies between the Malays and Indians differed significantly (P = 0.04). In this Asian population, the overall distribution of genotypes (CC, CT and TT) and allele frequencies were significantly different from those in Africans (P < 0.001). The results were also significant when the Chinese, Malays and Indians were compared separately with the African group (P < 0.001). Compared with the Caucasian data, the overall distribution of genotype and allele frequencies in the Asian population were also significantly different (P ≤ 0.05). However, when each Asian ethnic group was compared separately with the Caucasians, only the Indians were found to be significantly different (P ≤ 0.004). Genotypic–phenotypic correlations of this SNP were assessed in 10 stable Chinese heart transplant patients. The median AUC(0,4 h) was 11% lower in patients with CC genotype compared with subjects with TT genotype. However, the interpatient variability in AUC(0,4 h) was high in patients, especially in those with CC genotype.Conclusions  The distribution of the SNP C3435T in exon 26 in the Chinese and Malay population was found to be similar to the Caucasians whereas the Indians were different. The Asian population also differed significantly from the African and Caucasian population in the distribution of the C3435T SNP. The low frequency of the T allele in the Indian population implies lower expression of P‐gp and may have important therapeutic and prognostic implications for use of P‐gp dependent drugs in individuals of Indian origin.
Heat‐stress effects on reproduction and seed set in Linum usitatissimum L. (flax)
Authors: CROSS R. H. , MCKAY S. A. B. , G. MHUGHEN A. , BONHAM‐SMITH P. C. 
Published: July 2003

ABSTRACTHeat stress can detrimentally affect the reproductive capacity of many plants. The effect of a 7 or 14 d heat stress on flowering, seed set, pollen viability and germinability of flax (Linum usistatissimum L.) was assessed under growth chamber conditions. An incremental (2 °C/h), cyclical (daytime high 40 °C and night‐time low 18 °C) heat stress was applied 12 d after the initiation of flowering. Although flower formation in flax was not affected by heat stress, boll formation and seed set were reduced with onset of the heat stress. On removal of heat stress the stressed plants showed a compensatory response, flowering and producing bolls at a greater rate than the control plants. Heat stress significantly prolonged flowering by 17 d. Boll weight and seed weight were reduced with heat stress and the number of malformed, sterile seed increased three‐fold after 14 d of heat stress. Pollen viability and appearance were negatively affected after 6 and 10 d of heat stress, respectively. Pollen germinability decreased by the sixth day of heat stress, with no pollen germinating by the tenth day. Effects of heat stress on pollen viability and germinability alone, which did not occur until after the sixth day of the stress, could not account for the decreased boll formation due to heat stress in flax. These observations suggest that a combined effect of heat stress on both pollen and ovules contributes to decreased boll formation and seed set in flax.
In vitro analysis of the sequences required for transcription of the Arabidopsis thaliana 5S rRNA genes
Authors: Cloix Catherine , Yukawa Yasushi , Tutois Sylvie , Sugiura Masahiro , Tourmente Sylvette 
Published: July 2003

Summary In vivo, we have already shown that only two of the 5S rDNA array blocks of the Arabidopsis thaliana genome produce the mature 5S rRNAs. Deletions and point mutations were introduced in an Arabidopsis 5S rDNA‐transcribed region and its 5′‐ and 3′‐flanks in order to analyse their effects on transcription activity. In vitro transcription revealed different transcription control regions. One control region essential for transcription initiation was identified in the 5′‐flanking sequence. The major sequence determinants were a TATA‐like motif (−28 to −23), a GC dinucleotide (−12 to −11), a 3‐bp AT‐rich region (−4 to −2) and a C residue at −1. They are important for both accurate transcription initiation and transcription efficiency. Transcription level was regulated by polymerase III (Pol III) re‐initiation rate as in tRNA genes in which TATA‐like motif is involved. Active 5S rDNA transcription additionally required an intragenic promoter composed of an A‐box, an Intermediate Element (IE) and a C‐box. Double‐stranded oligonucleotides corresponding to different fragments of the transcribed region, used as competitors, revealed the main importance of internal promoter elements. A stretch of four T is sufficient for transcription termination. Transcription of Arabidopsis 5S rDNA requires 30 bp of 5′‐flanking region, a promoter internal to the transcribed region, and a stretch of T for transcription termination.
High-Level Expression of Truncated Surface Antigen P50 of
Babesia gibsoni
in Insect Cells by Baculovirus and Evaluation of Its Immunogenicity and Antigenicity
Authors: Fukumoto Shinya , Xuan Xuenan , Kadota Kimie , Igarashi Ikuo , Sugimoto Chihiro , Fujisaki Kozo , Nagasawa Hideyuki , Mikami Takeshi , Suzuki Hiroshi 
Published: July 2003

ABSTRACT

Previously, we identified an immunodominant antigen, P50 of
Babesia gibsoni.
In the present study, the gene encoding the truncated P50 (rP50t) without a C-terminal hydrophobic region (29 amino acids [aa]) was expressed in insect cells by a recombinant baculovirus. The highly hydrophobic C-terminal 20-aa regions seems to be a transmembrane region, which was evidenced by the fact that rP50t was effectively secreted into the supernatant of insect cells infected with the recombinant baculovirus. N-terminal amino acid sequence analysis of rP50t indicated that N-terminal 19 aa function as a signal peptide. The expression level of rP50t reached up to 2 mg per 10
8
cells infected with the recombinant baculovirus. The immunogenic property of rP50t was evaluated by an immunization test in mice. Mice immunized with rP50t induced a high-level antibody titer against the
B. gibsoni
merozoite. Monoclonal antibodies (MAbs) to rP50t were produced in mice to determine the immunogenic regions of P50. The epitope(s) recognized by all five MAbs were located between aa 190 and 273, suggesting that the central part of P50 is a highly immunogenic region. The diagnostic potential of rP50t was evaluated using an enzyme-linked immunosorbent assay (ELISA). The ELISA was able to differentiate clearly (
P
< 0.0001) between
B. gibsoni
-infected dog serum and
B. canis
-infected dog serum or noninfected dog serum. Our results indicated that the rP50t may provide a useful potential immunogenic reagent for use in diagnosis and as a subunit vaccine to control
B. gibsoni
infection in dogs.
Infection by Gram-Negative Organisms via the Biliary Route Results in Greater Mortality than Portal Venous Infection
Authors: Jeyarajah D. Rohan , Kielar Mariusz L. , Frantz Nicole , Lindberg Guy , Lu Christopher Y. 
Published: July 2003

ABSTRACTCholangitis requires bile duct obstruction and infection. Patients with cholangitis are often more affected than those with infections that reach the liver through the portal vein. We will attempt to study the influences of (i) route of entry and (ii) presence of bile duct obstruction on hepatic infection. C57BL/6 mice received injections ofEscherichia colior lipopolysaccharide into the obstructed bile duct or portal vein and were monitored for survival. Livers were assayed for bacteria, and cytokine mRNA was measured. In order to examine the effect of biliary obstruction on hepatic infection, animals were subjected to bile duct ligation 1 day prior to portal vein injection and were monitored for survival. The 50% lethal dose (LD50) forE. coliinjected into the bile duct was 50 CFU/animal; the LD50forE. coliinjected into the portal vein was 5 × 107CFU/animal. Initial hepatic delivery of bacteria was equivalent 1 h after injection into the bile duct or portal vein. However, by 24 h, a significantly greater amount of bacteria was recovered from the livers of the bile duct-injected group. Interleukin 10 (IL-10) and IL-1RA mRNA was expressed at greater levels in the bile duct-injected group. Prior bile duct ligation followed by portal vein injection resulted in a higher incidence of death than when sham operation was performed prior to portal vein injection. Our data suggest that the increased mortality from cholangitis, compared with that from other hepatic infections, is related to the different route of delivery of pathogen and the maladaptive response (possibly involving IL-10 and IL-1RA) to biliary obstruction itself.
Production and Characterization of a Human Recombinant Monoclonal Fab Fragment Specific for Influenza A Viruses
Authors: Desogus Alessandra , Burioni Roberto , Ingianni Angela , Bugli Francesca , Pompei Raffaello , Fadda Giovanni 
Published: July 2003

ABSTRACT

A human recombinant monoclonal Fab fragment that specifically recognizes all the influenza A virus strains tested was produced in transformed
Escherichia coli
using the phage display technique. No strain of influenza B virus reacted with it. It was purified after four cycles of panning and by a single passage through an immunoaffinity column. About 1 mg of pure monoclonal antibody was obtained from 1 liter of culture medium in 3 working days. The Fab fragment reacted with a viral 27-kDa protein, which could reasonably be a matrix protein. Indirect immunofluorescence tests performed on virus-infected MDCK cells showed that this Fab fragment was at least equally efficient as other commercial monoclonal antibody-based systems in detecting influenza A viral infections. The potential advantages of human recombinant Fabs on murine monoclonal antibodies are discussed.
Changes in Avidity and Level of Immunoglobulin G Antibodies to
Mycobacterium tuberculosis
in Sera of Patients Undergoing Treatment for Pulmonary Tuberculosis
Authors: Pereira Arias-Bouda Lenka M. , Kuijper Sjoukje , Van Der Werf Anouk , Nguyen Lan N. , Jansen Henk M. , Kolk Arend H. J. 
Published: July 2003

ABSTRACT

Much is known about specific antibodies and their titers in patients with tuberculosis. However, little is known about the avidity of these antibodies or whether changes in avidity occur during the progression of the disease or during treatment. The aims of this study were to determine the avidity of antibodies to
Mycobacterium tuberculosis
in patients with pulmonary tuberculosis, to explore the value of avidity determination for the diagnosis of tuberculosis, and to study changes in levels of antibodies and their avidity during treatment. Antibody avidity was measured by an enzyme-linked immunosorbent assay with thiocyanate elution. Avidity indices and serum levels of immunoglobulin G to
M
.
tuberculosis
were determined for 22 patients with pulmonary tuberculosis before and during treatment and for 24 patients with other pulmonary diseases. Antibody levels and avidity were both significantly higher in untreated tuberculosis patients than in the controls. Avidity determination had more diagnostic potential than determination of the antibody levels. Tuberculosis patients with a long duration of symptoms had higher antibody avidity than those with a recent onset of symptoms, indicating affinity maturation of specific antibodies during active disease. In the early phase of treatment, a decrease in antibody avidity was observed for 73% of all tuberculosis patients, accompanied by an initial increase in antibody levels in 36% of these patients. These phenomena could be explained by an intense stimulation of the humoral response by antigens released from killed bacteria, reflecting early bactericidal activity of antituberculous drugs leading to the production of low-affinity antibodies against these released antigens.
Beyond the Food Web Connections to a Deeper Industrial Ecology
Authors: Spiegelman Jonah 
Published: July 2003

SummaryIndustrial ecology is a school of thought based, in part, upon a simple analogy between industrial systems and ecological systems in terms of their material and energy flows. This article argues for a more sophisticated connection between these diverse systems based on the fact that they are all complex self‐organizing systems, operating far from thermodynamic equilibrium. As such, industrial and ecological systems have in common certain constraints and dynamic properties that move beyond the central metaphor of industrial ecology and could align these systems under a more comprehensive analytical framework. If incorporated at a fundamental level, the complex systems framework could add depth and sophistication to the field of industrial ecology.
The Biomass Metabolism of the Food System: A Model‐Based Survey of the Global and Regional Turnover of Food Biomass
Authors: Wirsenius Stefan 
Published: July 2003

SummaryThe food and agriculture system is among the largest anthropogenic activities in terms of appropriation of land and biological primary production, as well as alteration of the grand biogeochemical cycles of carbon, water, and nitrogen. Despite its importance in these respects, physically coherent descriptions and analyses of the food and agriculture system regarding the total turnover of fundamental flows (such as biomass) and resource use and efficiency of critical processes (such as animal food production) are relatively scarce.This article presents a survey of the current flows of biomass in the food and agriculture system. The survey gives a mass‐ and energy‐balanced description of biomass from its production on cropland and grassland through its transformations into animal and vegetable food products to its final conversion into respiratory heat, feces, and other residues. This assessment was carried out by means of a physical model that, for eight world regions, calculates the necessary production of crops and other phytomass (plant biomass) from a prescribed end use of food, efficiency in food production and processing, and use of system‐internal by‐products and residues as feed, feedstock, and food.The global appropriation of terrestrial phytomass production by the food system was estimated to be some 13 Pg (1.43 × 1010 short tons) dry matter, or 230 EJ (2.18 × 1017 Btu) gross energy (higher heating value), per year in 1992‐1994. Of this phytomass, about 8% ended up in food commodities eaten. Animal food systems accounted for roughly two‐thirds of the total appropriation of phytomass, whereas their contribution to the human diet was about 13% (both on a gross energy basis). The ruminant meat systems were found to have a far greater influence than any other subsystem on the food system's biomass metabolism, primarily because of the lower feed‐conversion efficiency (calculated as carcass produced by total feed intake, including pasture and other human‐inedible feedstuffs) of those systems.
Corrected TOGA COARE Sounding Humidity Data: Impact on Diagnosed Properties of Convection and Climate over the Warm Pool
Authors: Ciesielski Paul E. , Johnson Richard H. , Haertel Patrick T. , Wang Junhong 
Published: July 2003

Abstract
This study reports on the humidity corrections in the Tropical Ocean Global Atmosphere (TOGA) Coupled Ocean–Atmosphere Response Experiment (COARE) upper-air sounding dataset and their impact on diagnosed properties of convection and climate over the warm pool. During COARE, sounding data were collected from 29 sites with Vaisala-manufactured systems and 13 sites with VIZ-manufactured systems. A recent publication has documented the characteristics of the humidity errors at the Vaisala sites and a procedure to correct them. This study extends that work by describing the nature of the VIZ humidity errors and their correction scheme. The corrections, which are largest in lower-tropospheric levels, generally increase the moisture in the Vaisala sondes and decrease it in the VIZ sondes.
Use of the corrected humidity data gives a much different perspective on the characteristics of convection during COARE. For example, application of a simple cloud model shows that the peak in convective mass flux shifts from about 8°N with the uncorrected data to just south of the equator with corrected data, which agrees better with the diagnosed vertical motion and observed rainfall. Also, with uncorrected data the difference in mean convective available potential energy (CAPE) between Vaisala and VIZ sites is over 700 J kg−1; with the correction, both CAPEs are around ∼1300 J kg−1, which is consistent with a generally uniform warm pool SST field. These results suggest that the intensity and location of convection would differ significantly in model simulations with humidity-corrected data, and that the difficulties which the reanalysis products had in reproducing the observed rainfall during COARE may be due to the sonde humidity biases.
The humidity-corrected data appear to have a beneficial impact on budget-derived estimates of rainfall and radiative heating rate, such that revised estimates show better agreement with those from independent sources.
Titanium and Titanium Alloys—From Raw Material to Semi‐finished Products
Authors: Sibum H. 
Published: July 2003

AbstractWith a total of 0.6 %, titanium ranks fourth among metals, behind iron, aluminum, and magnesium, and ninth among all elements in the Earth’s crust. However, even today it has not yet lost the air of an exotic and expensive material. The majority of titanium is used as oxide (about 95 %) in the paint industry as whitener or filler material. Not many people are aware of the fact that titanium as oxide is part of everyday life, e.g., in toothpaste, white paint, sun blockers, etc. The main reason behind the late use of titanium as a metal is the difficult and costly reduction of oxide to metal.
Titanium Alloys for Aerospace Applications
Authors: Peters M. , Kumpfert J. , Ward C.H. , Leyens C. 
Published: July 2003

AbstractThere is probably no other material more closely related to aerospace than titanium and its alloys. With a density of 4.5g/cm3, titanium alloys are only about half as heavy as steel or Ni‐based superalloys, yielding an excellent strength‐to‐weight ratio. Furthermore, they have exceptional corrosion resistance. The use of titanium alloys in the aerospace sector will be highlighted including airframe, engine, helicopter, and space applications.
A Method To Detect Viable Helicobacter pylori Bacteria in Groundwater
Authors: Flanigan Debbie , Rodgers Mark 
Published: July 2003

AbstractThe inability to detect the presence of viable Helicobacter pylori bacteria in environmental waters has hindered the public health community in assessing the role water may play in the transmission of this pathogen. This work describes a cultural enrichment method coupled with an H. pylori‐specific PCR to identify these bacteria in water. While far from perfected at the present time, this represents an exciting new approach to studying the significance of water as a transmission mechanism for H. pylori. Evidence is presented that indicates culturable H. pylori bacteria were found using this enrichment/PCR method in a local groundwater source.
Stady‐state and Dynamical Simulation of an Autothermal Gasoline Reformer
Authors: Springmann S. , Bohnet M. , Sommer M. , Himmen M. , Eigenberger G. 
Published: July 2003

AbstractDetailed numerical simulation is an important tool for the analysis, development and optimization of new reactor systems. In this contribution results of steady‐state and dynamic simulations of a hydrogen production system for mobile applications based on gasoline are presented. The system consists of an autothermal reformer, a high temperature shift reactor and a countercurrent heat exchanger for heat integration. The simulations are based on 1‐D, multiphase, dynamic models, which are solved with the simulation tool PDEX‐Pack. Firstly steady‐state and dynamic simulations of the autothermal reformer alone are presented. Concentration and temperature profiles in the reformer under different operation conditions are discussed and possibilities to improve the performance are assessed. Dynamic simulations of load change and cold start show the fast dynamic response of the reformer due to its low thermal mass. Simulations of the coupled system underline the impact of the heat exchanger design for the system performance, especially under dynamic conditions. Finally dynamic simulations of a possible cold start strategy for the system are discussed.