bluuebunny/crossref_metadata_2025_split huggingface dataset:
Boiler and combustion safety: What you don't know can kill you!
Authors: Puskar John R. 
Published: May 2005

AbstractBetween 1993 and 2003, industrial plant explosions claimed 34 lives and caused numerous injuries in the United States alone, according to the National Board of Boiler and Pressure Vessel Inspectors. Equipment, other than boilers, such as paint ovens, hot water heaters, process air heaters, and heat treat equipment not operated or maintained properly have also caused their share of major death, injuries and devastation. Many of these tragedies could have been prevented with proper fuel system and combustion equipment safety precautions. Some of these have devastated industry with well‐publicized incidents.This article will discuss protections that are built into combustion equipment used within industry today. It will also discuss gross misconceptions that most owners and users have about the safety of these systems and how well they are protected. This will include a look at some of the groups involved in the design and annual review of this equipment and how even with these checks and balances equipment can be in a hazardous condition. Finally, elements of a comprehensive fuel and combustion equipment safety program are discussed. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Spin polarization and electronic structure of ferromagnetic Mn5Ge3 epilayers
Authors: Panguluri R. P. , Zeng Changgan , Weitering H. H. , Sullivan J. M. , Erwin S. C. , Nadgorny B. 
Published: May 2005

AbstractGermanium‐based alloys hold great promise for future spintronics applications, due to their potential for integration with conventional Si‐based electronics. High‐quality single phase Mn5Ge3(0001) films, grown by solid‐phase epitaxy on Ge(111) and GaAs(111), exhibit strong ferromagnetism up to the Curie temperature TC ∼ 296 K. Point Contact Andreev Reflection (PCAR) measurements on Mn5Ge3 epilayers reveal a spin‐polarization P = 42 ± 5% for both substrates. We also calculate the spin polarization of bulk Mn5Ge3 in the diffusive and ballistic regimes using density‐functional theory (DFT). The measured spin polarization exceeds the theoretical estimates of PDFT = 35 ± 5% and 10 ± 5% for the diffusive and ballistic limits, respectively. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab initio density functional study of MgO (001) surface with topological defects
Authors: Licona R. , Rivas‐Silva J. F. 
Published: May 2005

AbstractMagnesium oxide (MgO) is a useful material because of its catalytical properties. Moreover, surface defects have been found to play a crucial role in determining the activity and selectivity of catalytic surfaces. We present the results of a theoretical investigation of the electronic structure of the MgO (001) surface with three different topological defects. Our calculations are based on density functional theory (DFT) and the pseudopotential method. Slab geometry and periodic boundary conditions have been included with occupied orbitals expanded in plane waves. We compare the obtained results of the (001) MgO clean surface with those containing topological defects. The density of states DOS is analyzed in each case, as well as the chemical nature of the atoms belonging to the defects. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Exact electronic properties in the classically forbidden region of a metal surface
Authors: Qian Zhixin , Sahni Viraht 
Published: May 2005

AbstractWe derive exact properties of the inhomogeneous electron gas in the asymptotic classically forbidden region at a metal–vacuum interface within the framework of local effective potential energy theory. We derive a new expression for the asymptotic structure of the Kohn–Sham density functional theory (KS‐DFT) exchange‐correlation potential energyvxc(r) in terms of the irreducible electron self‐energy. We also derive the exact asymptotic structure of the orbitals, density, the Dirac density matrix, the kinetic energy density, and KS exchange energy density. We further obtain the exact expression for the Fermi hole and demonstrate its structure in this asymptotic limit. The exchange‐correlation potential energy is derived to bevxc(z→ ∞) = −αKS,xc/z, and its exchange and correlation components to bevx(z→ ∞) = −αKS,x/zandvc(z→ ∞) = −αKS,c/z, respectively. The analytical expressions for the coefficients αKS,xcand αKS,xshow them to be dependent on the bulk‐metal Wigner–Seitz radius and the barrier height at the surface. The coefficient αKS,c= 1/4 is determined in the plasmon‐pole approximation and is independent of these metal parameters. Thus, the asymptotic structure ofvxc(z) in the vacuum region is image‐potential‐like but not the commonly accepted one of −1/4z. Furthermore, this structure depends on the properties of the metal. Additionally, an analysis of these results via quantal density functional theory (Q‐DFT) shows that both the PauliWx(z→ ∞) and lowest‐order correlation‐kineticW(z→ ∞) components of the exchange potential energyvx(z→ ∞), and the CoulombWc(z→ ∞) and higher‐order correlation‐kinetic components of the correlation potential energyvc(z→ ∞), all contribute terms ofO(1/z) to the structure. Hence correlations attributable to the Pauli exclusion principle, Coulomb repulsion, and correlation‐kinetic effects all contribute to the asymptotic structure of the effective potential energy at a metal surface. The relevance of the results derived to the theory of image states and to KS‐DFT is also discussed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Quantum dynamics of relaxation of a pair of coupled Morse oscillators: Effects of mass and electrical asymmetries
Authors: Maji Kaushik , Bhattacharyya S. P. 
Published: May 2005

AbstractA multiconfiguration time‐dependent Hartree method based recipe is used to study the role of mass and electrical asymmetry in controlling the quantum dynamics of relaxation of a locally excited OH bond in a water molecule, modeled by a pair of interacting Morse oscillators. The fast periodic energy transfer between the two equivalent OH bonds in HOH is replaced by a rather slow process when one of the H atom is replaced by a deuterium atom. Application of static electric field along the OD bond in HOD molecule is seen to either enhance or damp the relaxation rate, depending on the strength of the applied field. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Genetic diversity of the toxic cyanobacterium Microcystis in Lake Mikata
Authors: Yoshida Mitsuhiro , Yoshida Takashi , Takashima Yukari , Kondo Ryuji , Hiroishi Shingo 
Published: May 2005

AbstractThe aim of the present study was to clarify the bloom dynamics and community composition of hepatotoxin microcystin‐producing and non‐microcystin‐producing Microcystis genotypes in the environment. In Lake Mikata (Fukui, Japan) from April 2003 to January 2004, seasonal variation in the number of cells with microcystin (mcy) genotypes and the genetic diversity of the total population were investigated using quantitative competitive PCR and a 16S rDNA clone library, respectively. Using competitive PCR, cells with mcyA genotypes were quantified in August and October, and the ratio of the number of these mcyA genotypes to colony‐forming Microcystis cells was 0.37 and 2.37, respectively. The 16S rDNA clones obtained could be divided into 12 ribotypes: a–l. Sixty‐one Microcystis strains isolated from Lake Mikata during the sampling period were subjected to toxicity tests using HPLC and ELISA, PCR‐based detection of the mcyA gene, and sequence analysis of the 16S rDNA. All isolates could be differentiated into 11 ribotypes (a, b, d, f, h, i, and m–q). Ribotypes b, f, i, m, n, and p had at least one strain that was a microcystin producer. In natural communities ribotypes b and f accounted for 85% of the 16S rDNA clones in August, and ribotypes b and i accounted for 24% of the clones in October. Thus, in some bloom stages the presence of microcystin genotypes identified using the 16S rDNA clone library correlated with that of mcy genotypes determined using competitive PCR. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 229–234, 2005.
Identification of potentially toxic environmental Microcystis by individual and multiple PCR amplification of specific microcystin synthetase gene regions
Authors: Ouahid Youness , Pérez‐Silva Gonzalo , Campo Francisca F. del 
Published: May 2005

AbstractReliable cyanotoxin monitoring in water reservoirs is difficult because of, among other reasons, unpredictable changes in cyanobacteria biomass, toxin production, and inadequate sampling frequency. Therefore, it would be useful to identify potentially microcystin‐producing strains of cyanobacterial populations in field samples. With this aim, we developed a methodology to distinguish microcystin‐producing from non‐producing Microcystis strains by amplifying six characteristic segments of the microcystin synthetase mcy cluster, three corresponding to the nonribosomal peptide synthetase, genes mcyA, mcyB, and mcyC, and three to the polyketide synthase, genes mcyD, mcyE, and mcyG. For this purpose five new primer sets were designed and tested using purified DNA, cultured cells, and field colonies as DNA sources. Simultaneous amplification of several genes in multipex PCR reactions was performed in this study. The results obtained showed that: (i) the expected specific amplicons were obtained with all microcystin‐producing strains but not with nonproducing strains; (ii) cells could be directly used as DNA templates, 2000 cells being a sufficient number in most cases; (iii) simultaneous amplification of several gene regions is feasible both with cultured cells and with field colonies. Our data support the idea that the presence of various mcy genes in Microcystis could be used as a criterion for ascribing potential toxigenicity to field strains, and the possibility of applying whole‐cell assays for the simultaneous amplification of various genes may contribute significantly to simplifying toxigenicity testing. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 235–242, 2005.
Seasonal production and molecular characterization of microcystins in Oneida Lake, New York, USA
Authors: Hotto Amber , Satchwell Mike , Boyer Gregory 
Published: May 2005

AbstractOneida Lake, northeast of Syracuse, New York, in the United States, is a shallow eutrophic lake with a well‐established toxic cyanobacterial population. Samples for DNA, toxin, and phycological analyses were collected from six stations throughout the summers of 2002 (78 samples) and 2003 (95 samples). DNA was amplified by PCR using primer sets specific to the nonribosomal microcystin synthetase complex (mcyB and mcyD). PCR analysis in 2002 indicated that the microcystin genes were present in the water column from mid‐June through October, as 88% of the samples tested positive for mcyB and 79% of the samples tested positive for mcyD. In both years the onset of microcystin production was detected as early as mid‐July by the protein phosphatase inhibition assay, reaching a maximum in 2002 of 2.9 μg L−1 and in 2003 of 3.4 μg L−1. Beginning in mid‐ to late August of both years the microcystin level at all six stations was in excess of the World Health Organization (WHO) advisory level of 1.0 μg L−1. In the present study we compared microcystin occurrence and potential production at the six stations using protein phosphatase inhibition assay, high‐performance liquid chromatography, and polymerase chain reaction analyses. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 243–248, 2005.
First report of saxitoxin in Finnish lakes and possible associated effects on human health
Authors: Rapala Jarkko , Robertson Alison , Negri Andrew P. , Berg Katri A. , Tuomi Pirjo , Lyra Christina , Erkomaa Kirsti , Lahti Kirsti , Hoppu Kalle , Lepistö Liisa 
Published: May 2005

AbstractThis study is the first report of saxitoxin in cyanobacterial blooms in Finland. Bloom samples (n = 50) were collected from Finnish freshwater sites during summer months of 2002 and 2003. These samples were screened for the presence of paralytic shellfish toxins (PSTs) using the Jellett rapid PSP screening test. Samples testing positive for PSTs (n = 7) were further analyzed with saxiphilin‐ and voltage‐gated sodium channel [3H]‐STX–binding radioreceptor assays and liquid chromatography using fluorescence and mass spectrometric analysis. The results indicated that saxitoxin (STX) was the only PST analogue in the samples and that it was present in high concentrations, as much as 1 mg L−1. Microscopic analysis revealed that 95%–100% of the phytoplankton in the positive samples consisted of Anabaena lemmermannii. The trophic status of lakes in which STX‐containing blooms were found varied from oligotrophic to hypertrophic. All the lakes had high nitrogen‐to‐phosphorus ratios. In some instances, samples had been collected from sites where swimmers had reported adverse health effects, and in three such cases, reported adverse health effects were associated with sites from which samples testing positive for STX had been received. Symptoms of fever, eye irritation, abdominal pains, and skin rash were reported in children aged 2–10 years after exposure to the water. These were not the adverse human symptoms typical of STX poisoning; rather, they represented acute effects often reported following recreational exposure to cyanobacterial blooms. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 331–340, 2005
Genotoxic potential of Microcystin‐LR and nodularin in vitro in primary cultured rat hepatocytes and in vivo in rat liver
Authors: Bouaïcha Noureddine , Maatouk Imed , Plessis Marie‐José , Périn François 
Published: May 2005

AbstractMicrocystin‐LR (MCYST‐LR) and nodularin (NOD) are known as tumor promoters in experimental animals and so present potential health threats for humans. Although their hepatotoxic mechanisms have been very well documented, many other effects of these toxins are relatively undescribed, indeed controversial, notably those related to their genotoxicity. In the present investigation, we examined how these toxins could induce DNA damage using a combination of in vitro and in vivo approaches. We first used the 32P‐postlabeling assay to test hydrophobic adduct formation on DNA from primary cultured rat hepatocytes treated with noncytotoxic concentrations of MCYST‐LR and NOD (2 and 10 ng/mL). Analysis of the autoradiograms of DNA digests isolated from the hepatocytes did not show any hydrophobic DNA adduct formation. However, these toxins significantly decreased the amount of hydrophobic endogenous adducts, termed I compounds. We next investigated oxidative DNA damage by using the 32P‐postlabeling assay to analyze 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine (8‐oxo‐dG) content as a biomarker of possible DNA lesions. Both MCYST‐LR and NOD significantly enhanced 8‐oxo‐dG in time‐ and dose‐dependent manner in vitro in primary cultured hepatocytes and in vivo in rat liver cells. Thus, it appears that the depletion of endogenous DNA adducts (I compounds) and/or the increase of 8‐oxo‐dG levels by MCYST‐LR and NOD could be involved in the formation of hepatic tumors during long‐term exposure to these cyanobacterial hepatotoxins. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 341–347, 2005.
Avian vacuolar myelinopathy linked to exotic aquatic plants and a novel cyanobacterial species
Authors: Wilde Susan B. , Murphy Thomas M. , Hope Charlotte P. , Habrun Sarah K. , Kempton Jason , Birrenkott Anna , Wiley Faith , Bowerman William W. , Lewitus Alan J. 
Published: May 2005

AbstractInvasions of exotic species have created environmental havoc through competition and displacement of native plants and animals. The introduction of hydrilla (Hydrilla verticillata) into the United States in the 1960s has been detrimental to navigation, power generation, water intake, and water quality (McCann et al., 1996). Our field surveys and feeding studies have now implicated exotic hydrilla and associated epiphytic cyanobacterial species as a link to avian vacuolar myelinopathy (AVM), an emerging avian disease affecting herbivorous waterbirds and their avian predators. AVM, first reported in 1994, has caused the death of at least 100 bald eagles (Haliaeetus leucocephalus) and thousands of American coots (Fulica americana) at 11 sites from Texas to North Carolina (Thomas et al., 1998; Rocke et al., 2002). Our working hypothesis is that the agent of this disease is an uncharacterized neurotoxin produced by a novel cyanobacterial epiphyte of the order Stigonematales. This undescribed species covers up to 95% of the surface area of leaves in reservoirs where bird deaths have occurred from the disease. In addition, this species is rare or not found on hydrilla collected at sites where AVM disease has not been diagnosed. Laboratory feeding trials and a sentinel bird study using naturally occurring blooms of cyanobacteria on hydrilla leaves and farm‐raised mallard ducks (Anas platyrhynchos) induced the disease experimentally. Since 1994 AVM has been diagnosed in additional sites from Texas to North Carolina. Specific site characteristics that produce the disjunct distribution of AVM are unknown, but it is probable that the incidence of this disease will increase with the introduction of hydrilla and associated cyanobacterial species into additional ponds, lakes, and reservoirs. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 348–353, 2005.
Insecticidal compounds of the biofilm‐forming cyanobacterium Fischerella sp. (ATCC 43239)
Authors: Becher Paul G. , Jüttner Friedrich 
Published: May 2005

AbstractCyanobacterial biofilms are grazed by many different benthic invertebrates. In particular, larvae of insects are often present in great numbers and exert strong grazing pressure on cyanobacteria. Along with morphological adaptations, allelochemicals may have been developed as defense mechanisms against insect larvae. To investigate the chemical defense of biofilm‐forming cyanobacteria, larvae of Chironomus sp., a widely distributed genus in this habitat, were used. Ten artificial biofilms of axenic and nonaxenic cyanobacteria were screened for insecticidal activity against Chironomus sp. Fischerella 43239 was the cyanobacterium that exhibited the highest acute toxicity. A bioassay‐guided isolation procedure was used to study the compounds responsible for toxicity in more detail. A toxic fraction was obtained when the 60% methanolic extract of Fischerella 43239 was separated on a C18 HPLC column. Electrospray mass spectrometry indicated the presence of several compounds in this fraction. The successful separation into individual compounds was achieved by HPLC on a cyanopropyl column. The heavily clustered quasimolecular ions observed on an electrospray mass spectrometer and the absorption spectra of the separated compounds were indicative of indole derivatives. The existence in the benthic cyanobacterium Fischerella 43239 of strong insecticidal metabolites that serve as chemical protection agents against insect larvae is supported by the data. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 363–372, 2005.
Quantitative LC‐ESI‐MS analyses of microcystins and nodularin‐R in animal tissue—Matrix effects and method validation
Authors: Karlsson Krister M. , Spoof Lisa E. M. , Meriluoto Jussi A. O. 
Published: May 2005

AbstractThe matrix effects and signal response in LC‐MS analysis of six microcystins and nodularin‐R were studied in mussels and liver samples from the common eider and rainbow trout. The instrumentation used in the study was a triple quadrupole MS with electrospray ionization. The results from the spiked tissue samples showed that both signal suppression and enhancement occurred. The recorded matrix effects were not severe; all studied toxins could be detected with sufficient limit of detection in all matrices. The results indicate, however, that matrix effects must be monitored for accurate quantification of microcystin and nodularin in tissue samples. Matrix effects can be studied with standard additions in the studied matrix, as was done in this study. Solid‐phase extraction (SPE) resulted in a lower limit of detection compared to no cleanup in the sample preparation. SPE also prolonged the chromatographic stability. SPE cleanup is therefore strongly recommeded. Also described in this article are the chromatographic and mass spectrometric details of glutathione and cysteine conjugates, which are the detoxification products of the toxins. LC‐MS analysis is suitable for detoxification studies of microcystins and nodularins. Cysteine conjugate was identified as the main detoxification product in a mussel sample that was exposed to toxic cyanobacteria in an aquarium. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 381–389, 2005.
Pressurized liquid extraction of toxins from cyanobacterial cells
Authors: Aranda‐Rodriguez Rocio , Tillmanns Angeline , Benoit Frank M. , Pick Frances R. , Harvie Jeromy , Solenaia Lioudmila 
Published: May 2005

AbstractThe suitability of pressurized liquid extraction (PLE) of cyanotoxins from cells was investigated. The stability of cyanotoxins (MCYST‐RR, MCYST‐LR, and anatoxin‐a) was evaluated at nine combinations of pressure and temperature (7, 10, and 14 MPa and 60°C, 80°C and 100°C) using 75% (v/v) methanol in water (MeOH) as solvent. Additional experiments investigated the stability of cyanotoxins when water was used as solvent (at a pressure of 14 MPa and a temperature of 40°C, 50°C, 60°C, 80°C, or 100°C). Results using 75% MeOH showed that the MCYST‐RR and MCYST‐LR were stable under the tested pressures up to 80°C. At 100°C MCYST recovery decreased by 10% to 17%. When water was used as the solvent, no differences in recovery were observed for MCYST‐LR, whereas for MCYST‐RR, maximum recovery was obtained at 60°C, and degradation occurred at 100°C. In contrast, anatoxin‐a was labile under all experimental conditions; the best recoveries (ca. 50%) were obtained at 60°C at the three pressures using 75% MeOH. However, only 17%–23% recovery was obtained with water extraction at all temperatures. The extraction of MCYST‐LR and variants from cells (Microcystis aeruginosa, UTCC299) was studied using two solvents, 75% MeOH and 100% water, at 14 MPa and 60°C and 100°C. PLE extracts were compared with extracts obtained with 75% MeOH and ultrasonication. Complete extraction was achieved in both solvents in one 5‐min cycle (at 100°C). Although lower recovery was obtained using PLE (79%–105%), shorter extraction time and automation are advantageous over ultrasonication. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 390–396, 2005.