A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect ...
Advances in molecular technologies challenge the different concepts of causality in biology, epidemiology and multistage mathematical models. The lack of integration of the different aspects of causality...Full Text Available
Using a novel, pulsed micro-second time-resolved photoacoustic (PA) instrument, we measured thermal dissipation and energy storage (ES) in the intact cells of wild type (WT) Chlamydomonas reinhardtii, and mutants lacking either PSI or PSII reaction centers (RCs). On this time scale, the kinetic contributions of the thermal expansion component due to heat dissipation of absorbed energy and the negative volume change due to electrostriction induced by charge separation in each of the photosystems could be readily distinguished. Kinetic analysis revealed that PSI and PSII RCs exhibit strikingly different PA signals where PSI is characterized by a strong electrostriction signal and a weak thermal expansion component while PSII has a small electrostriction component and large thermal expansion....
BackgroundChildhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the...Full Text Available
Development of mouse models representing human spontaneous ovarian cancer has been hampered by the lack of understanding of the etiology of this very complex disease. Mouse models representing the different...Full Text Available
In a given species, injected opioid peptides usually cause changes in temperature similar to those caused by nonpeptide opioids. The main effect in those species most studied, the cat, rat, and mouse, is an increase in the level about which body temperature is regulated; there is a coordinated change in the activity of thermoregulatory effectors such that hyperthermia is produced in both hot and cold environments. Larger doses may depress thermoregulation, thereby causing body temperature to decrease in the cold. Elicitation of different patterns of response over a range of environmental temperatures and studies with naloxone and naltrexone indicate that stimulation of a number of different receptors by both peptide and nonpeptide opioids can evoke thermoregulatory responses. ..beta..-Endorphin is readily antagonized by naloxone whereas methionine-enkephalin can act on naloxone-insensitive receptors. Moreover, synthetic peptide analogs do not ...
Lens-induced glaucoma comprises a number of different glaucomatous processes occurring in the elderly that share in common the role of the crystalline lens in the mechanism of increase in intraocular...Full Text Available
AbstractObjective To review studies investigating the brain correlates of unawareness of cognitive and behavioural symptoms in people with dementia. Design A detailed search of the literature was conducted to include all the peer-reviewed studies published in English aimed at identifying the structural or functional brain correspondents of unawareness in dementia patients. Their results were interpreted in relation to the methodological differences in terms of type of dementia studied, the protocol adopted to measure lack of awareness, the imaging techniques employed, the experimental designs and statistical analyses performed. Results Eighteen studies undertaken to explore the functional and structural correlates of unawareness of cognitive symptoms in dementia were identified. Although t...
Sulfur mustard (HD) is an alkylating and cytotoxic chemical warfare agent, which inflicts severe skin toxicity and an inflammatory response. Effective medical countermeasures against HD-caused skin toxicity are lacking due to limited knowledge of related mechanisms, which is mainly attributed to the requirement of more applicable and efficient animal skin toxicity models. Using a less toxic analog of HD, chloroethyl ethyl sulfide (CEES), we identified quantifiable inflammatory biomarkers of CEES-induced skin injury in dose- (0.05-2 mg) and time- (3-168 h) response experiments, and developed a CEES-induced skin toxicity SKH-1 hairless mouse model. Topical CEES treatment at high doses caused a significant dose-dependent increase in skin bi-fold thickness indicating edema. Histopathological e...
In APCs, presentation by MHC II molecules of the chemically dominant peptide from the protein hen egg white lysozyme (HEL) generates different conformational isomers of the peptide-MHC II complexes (pMHC). Type B pMHCs are formed in early endosomes from exogenous peptides in the absence of H2-DM, whereas in contrast, type A pMHC complexes are formed from HEL protein in late vesicles after editing by H2-DM. Thus, H2-DM edits off the more unstable pMHC complexes, which are not presented from HEL. In this study, we show that type B pMHC complexes were presented from HEL protein only after stimulation of dendritic cells (DC) with TLR ligands or type I IFN. Type I IFN contributed to most TLR ligand-induced type B pMHC generation, as presentation decreased in DC lacking the receptor for type I IFNs (IFNAR1(-/-)). In contrast, presentation of type A pMHC from HEL and from peptide was minimally affected by TLR ligands. The relative ...
Probabilistic assessment methods can be used to identify specific plant vulnerabilities. Application of such methods can also facilitate selection among system design alternatives available for safety enhancements. The quality of assessment results is however strongly dependent on realistic and accurate input data for modelling of system component behaviour and failure modes during conditions to be assessed. Use of conservative input data may not lead to results providing guidance on safety upgrades. Adequate input data for probabilistic assessments seems to be lacking for at least failure modes of some electrical components when exposed to a fire. This report presents an attempt to improve the situation with respect to such input data. In order to take advantage of information in existing documentation of fire incident occurrences some of the lessons learned from the fire at Browns Ferry Nuclear Power Plant on March 22, 1975 are discussed in this report. Also a ...
R-matrix analyses of neutron-induced reactions for many of the lightest p-shell nuclei are difficult due to a lack of distinct resonance structure in the reaction cross sections. Initial values for the required R-matrix parameters, E,sub(lambda) and ..gamma..sub(lambdac) for states in the compound system, can be obtained from shell model calculations. In the present work, the results of recent shell model calculations for the lithium isotopes have been used in R-matrix analyses of /sup 6/Li+n and /sup 7/Li+n reactions for E sub(n) < 8 MeV. Consequences of the shell model predictions for the level structure of /sup 7/Li and /sup 8/Li on the /sup 6/Li+n and /sup 7/Li+n reaction mechanisms and cross sections are discussed.
The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H_2O_2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, #gamma# rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O_2. The levels of endonuclease ...
Explants from flower stalks of Nicotiana tabacum L. were cultured on different cytokinins to induce flower bud formation. All cytokinins tested except zeatin and zeatin-riboside induced...Full Text Available
OBJECTIVES—To investigate the relation between different types of exposure to noise and a classic sign of noise induced hearing loss (NIHL), the audiometric notch. METHODS—The...Full Text Available
Populus yunnanensis was employed as a model species to detect sexual differences in growth, physiological, biochemical, and ultrastructural responses to cadmium (Cd) stress, nitrogen...Full Text Available
Advances in the theory and practice of stress corrosion cracking (SCC) are reviewed for the period 1965-1990. The proceedings of two landmark conferences are used as a basis for discussion: Ohio State University (1967) and Kohler, WI (1988). The discussion is developed around the following topics: metal-environment combinations, testing, fractography, metallurgical aspects, electrochemical aspects and crack chemistry, mechanisms, and prediction and mitigation. It is concluded that the main developments since 1967 are the recognition of the lack of specificity of SCC environments, the use of slow strain rate and fracture mechanics testing, quantitative SEM fractography, studies of grain boundary structure and compositions, transient electrochemistry of bare metal surfaces, measurement and modelling of crack chemistry, elaboration of several SCC models, including slip-dissolution and film induced cleavage, and mitigation by alloy development or ...
Bark beetles that colonize living conifers and their microbial associates encounter constitutive and induced chemical defenses of their host. Monoterpene hydrocarbons comprise a major component of these allelochemicals, and many are antibiotic to insects, fungi, and bacteria. Some bark beetle species exhaust these defenses by killing their host through mass attacks mediated by aggregation pheromones. Others lack adult aggregation pheromones and do not engage in pheromone-mediated mass attacks, but rather have the ability to complete development within live hosts. In the former species, the larvae develop in tissue largely depleted of host terpenes, whereas in the latter exposure to these compounds persists throughout development. A substantial literature exists on how monoterpenes affect b...
We previously reported that puromycin-insensitive leucyl-specific aminopeptidase (PILSAP) is required for vascular endothelial growth factor (VEGF)- and basic fibroblast growth factor (bFGF)-induced angiogenesis and for endothelial differentiation from embryonic stem (ES) cells via the aminopeptidase activity of PILSAP. In this study, we searched for molecules that function during angiogenesis with PILSAP. We performed proteome analysis of nuclear extracts from embryoid bodies (EBs) made from ES cells transfected with mutant PILSAP lacking aminopeptidase activity and mock EBs. We identified pigpen, a 67-kDa nuclear coiled body component protein. Immunoprecipitation and western blotting demonstrated the binding of PILSAP and pigpen in endothelial cells (ECs), and this interaction was enhanc...
Magnetic properties of Fe-Co-Mo-Cu-B alloy system with Co up to 26at.% were investigated. After proper thermal treatment, the nanocrystalline grain remains tiny, the density hardly increases, but the room-temperature saturation attains 1.5T mainly due to a high enough Curie temperature. The generally observed slant hysteresis loops point to ribbon surfaces, which stress the ribbon interior and induce a specific magnetoelastic contribution to hard-ribbon-axis magnetic anisotropy even after vacuum annealing. The effect does not come from cobalt but rather from the lack of silicon. Partial removal of the surfaces resulted in a decrease of the loop tilt.
Iron, zinc, copper and manganese are essential metals for cellular enzyme functions while cadmium, mercury and the metalloid arsenic lack any biological function. Both, essential metals, at high concentrations, and non-essential metals and metalloids are extremely reactive and toxic. Therefore, plants have acquired specialized mechanisms to sense, transport and maintain essential metals within physiological concentrations and to detoxify non-essential metals and metalloids. This review focuses on the recent identification of transporters that sequester cadmium and arsenic in vacuoles and the mechanisms mediating the partitioning of these metal(loid)s between roots and shoots. We further discuss recent models of phloem-mediated long-distance transport, seed accumulation of Cd and As and rec...
DescriptionLameness, commonly referred to as the leg health, in the modern broiler chicken is an emotive issue and the debate surrounding this subject is not helped by the lack of agreement as to how leg health should be assessed. A commonly used tool for scoring leg health is the Bristol Gait Score, a technique used in the recently reported Defra project AW0230 (`Leg Health and Welfare in Commercial Broiler Production`). The authors of the final report for AW0230 noted that for the chickens gait scored [continued...
The genetically and leukemia-significant doses (GSD and LSD) were calculated from the average gonad and bone marrow doses caused by the most frequently applied radiopharmaceuticals in Bulgaria in 1976. Because of the lack of information about the age groups of the patients examined assumptions have been made which led to estimated values of 0.97 mrad for GSD and 2.0 mrad for LSD which must be considered as the upper limit of the real GSD and LSD. The influence of the different radiopharmaceuticals on the average radiation exposure of the population is discussed. (author).
The field of stem cell research was revolutionized with the advent of induced pluripotent stem cells. By reprogramming somatic cells to pluripotent stem cells, most ethical concerns associated with the use of embryonic stem cells are overcome, such that many hopes from the stem cell field now seem a step closer to reality. Several methods and cell sources have been described to create induced pluripotent stem cells and we discuss their characteristics in terms of feasibility and efficiency. From these cells, cardiac progenitors and cardiomyocytes can be derived by several protocols and most recent advances as well as remaining limitations are being discussed. However in the short time period this technology has been around, evidence emerges that induced pluripotent stem cells may be more prone to genetic defects and maintain an epigenetic memory and thus may not be entirely the same as embryonic stem cells. Despite the ...
Males and females display differences in physiology, behaviour and susceptibility to many diseases. Genome-wide transcription profiling studies have uncovered large-scale sex differences in autosomal gene expression in somatic tissues that are thought to underlie such 'sexual dimorphisms'. Because males and females differ genetically mainly in their sex chromosome complement, most sex differences can be traced back to the X and Y chromosomes. Although sex hormones are usually considered the main architects of sexual dimorphisms, recent studies have demonstrated that sex chromosomes can also induce sex differences in somatic gene expression in the absence of hormonal differences. The recent discovery of epigenetic sex differences that are not hormone-induced brings us closer to understandin...
The aim of this paper is offering a critical review of Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS), the approach of multi-elemental quantitative analysis of LIBS spectra, based on the measurement of line intensities and plasma properties (plasma electron density and temperature) and on the assumption of a Boltzmann population of excited levels, which does not require the use of calibration curves or matrix-matched standards. The first part of this review focuses on the applications of the CF-LIBS method. Quantitative results reported in the literature, obtained in the analysis of various materials and in a wide range of experimental conditions, are summarized, with a special emphasis on the departure from nominal composition values. The second part is a discussion of the simplifying assumptions which lie at the basis of the CF-LIBS algorithm (stoichiometric ablation and complete atomization, thermal equilibrium, homogeneous plasma, thin ...
The aim of this paper is offering a critical review of Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS), the approach of multi-elemental quantitative analysis of LIBS spectra, based on the measurement of line intensities and plasma properties (plasma electron density and temperature) and on the assumption of a Boltzmann population of excited levels, which does not require the use of calibration curves or matrix-matched standards. The first part of this review focuses on the applications of the CF-LIBS method. Quantitative results reported in the literature, obtained in the analysis of various materials and in a wide range of experimental conditions, are summarized, with a special emphasis on the departure from nominal composition values. The second part is a discussion of the simplifying assumptions which lie at the basis of the CF-LIBS algorithm (stoichiometric ablation and complete atomization, thermal equilibrium, homogeneous plasma, thin ...
Purpose: The present research aims to identify the difficulties and obstacles for developing digital libraries in the seven regional branches of Islamic Azad University (IAU), Iran, and to study the status of librarians' skills and education programmes at these institutions. Design/methodology/approach: The 40 individuals working in the regional branch libraries of IAU were surveyed by a questionnaire consisting of 34 questions, and the collected data were analysed using SPSS software (version 16). Findings: It was found that the most important difficulties are the lack of suitable equipment and untrained personnel (i.e. a lack of sufficient training programmes). Research limitations/implications: Because of the small number of participants, it is suggested that a larger scale study is carried out. It is also proposed that the suggestions made by the participants will be considered and implemented, based on the digital library (DL) developments ...
Abstract A Pseudomonas sp. isolate MSB1 efficiently inhibited the growth of Flavobacterium psychrophilum of different serotypes on agar medium. A significant difference in the inhibition was observed between isolates of the less virulent FpT serotype compared to the Fd and Th serotypes. In broth coculture experiments, a low number of cells of MSB1 inhibited and outcompeted the F.psychrophilum cells. Also cell-free culture supernatant of MSB1 clearly repressed the growth of F.psychrophilum. A chromoazurol S assay suggested that MSB1 produced efficient siderophores, which most probably were responsible for the iron deficiency in the supernatant. The limited growth of F.psychrophilum in the supernatant was found to be partly because of the lack of available iron, but the results also indicate...
The risks from mining and processing of ores is reviewed on a generic basis with particular reference to some of the confusions which can arise due to lack of consistency or common logic in the use of exclusion, exemption and clearance. The difference in exclusion and exemption are challenged by comparing doses received in high background radiation areas and the doses received from a mining practice. The common principle of risk to the human species is not applied consistently. The differences between IAEA recommendations and local regulatory conditions are compared, and the use of exemption levels as clearance levels is considered. A case study on management of mine tailings is presented with special focus on the use of clearance levels. In all areas of review the interpretation of regulation is subject to confusion resulting from inconsistencies which can distort free market economics. (author).
Summary 1. A primary goal of evolutionary ecology is to understand factors selecting for the diversity of life histories. Life-history components, such as time-to-reproduction, adult survivorship and fecundity, might differ among species because of variation in direct and indirect benefits of these life histories in different environments or might have lower-than-expected variability because of phylogenetic constraints. Here, we present a phylogenetic examination of demography and life histories using a data base of 204 terrestrial plant species. 2. Overall, statistical models without phylogeny were preferred to models with phylogeny for vital rates and elasticities, suggesting that they lacked phylogenetic signal and are evolutionarily labile. However, the effect of phylogeny was signific...
The concept of sustainable consumption (SC) has been proposed as a way of operationalising sustainable development (SD). However, until now, in view of the difficulties in conceptualising SC, emphasis has been placed mainly on a pragmatic approach. In an a-conceptual and pragmatic account of SC, many problems remain unaddressed, such as the danger of the notion becoming empty and lack of integration between the different dimensions of sustainability. In this paper, we propose that the informational space provided by the capability approach (CA) offers a conceptual framework to elaborate SC. The CA is employed here (i) to discuss the philosophical underpinnings of SC as part of a strategy for enhancing quality-of-life and (ii) to investigate the links between the different dimensions of SC....
To determine a rat strain appropriate for carcinogenicity testing of FYX-051, a xanthine oxidoreductase inhibitor, we performed a 4-week oral toxicity study by administering 0.3, 1 and 3?mg/kg, and 1, 3 and 10?mg/kg of FYX-051 to male Sprague-Dawley (SD) and Fischer (F344) rats, respectively. Histopathology revealed that the degree of FYX-051-induced nephropathy was 3-fold stronger in SD rats than in F344 rats. Our previous study demonstrated that the key factor of species differences in FYX-051-induced nephropathy is purine metabolism. This observation led us to examine the involvement of purine metabolism in differences among two strains of rats. However, purine metabolism was proven not to be implicated as an important factor. Subsequently, other factors responsible for the strain diffe...
Mass distribution in 28.5 MeV alpha particle induced fission of "2"3"2Th has been determined using gamma spectrometric technique. The chain yields of 24 different fission products covering both symmetric and asymmetric mass divisions were determined. The mass distribution was found to be asymmetric with peak positions at mass numbers 96 and 136 respectively while the peak to valley ratio was 3.86. The results are compared with the available literature on 14 MeV neutron induced fission of "2"3"5U. (orig.).
Mass distribution in 28.5 MeV alpha particle induced fission of {sup 232}Th has been determined using gamma spectrometric technique. The chain yields of 24 different fission products covering both symmetric and asymmetric mass divisions were determined. The mass distribution was found to be asymmetric with peak positions at mass numbers 96 and 136 respectively while the peak to valley ratio was 3.86. The results are compared with the available literature on 14 MeV neutron induced fission of {sup 235}U. (orig.).
The effectiveness of the acridines ethidium bromide (EB) and acriflavine in inducing plasmon mutations was compared with the alkylating agents ethyl methanesulphonate (EMS) and diethyl sulphate and to #gamma#-rays. The growth habit (trailing versus bunch) of peanuts (A. hypogaea), controlled by genic-cytoplasmic interactions, was utilized. Breeding tests distinguishing nuclear from plasmon mutations were developed and are described in detail. Plasmon mutations were induced, but there were differences in mutation yields between the cultivars and the mutagens. (Auth.).
In the present study, a subcooled boiling loop with an annular flow on the electrically heated rod was used to make an experimental approach to investigate the effects of induced instability by the subcooled boiling on vibration of the rod in different subcooled conditions. The results show the intensive subcooled-boiling-induced vibration (SBIV) which is highly depend on dynamic force generated by fast vapor bubbles growth and collapse whilst they still attach to, or slide along, the heating surface at high loading heat fluxes. These behaviors were strongly influenced by the conditions of subcooling temperature, flow rate and linear power density. (author)
Many hormones elicit effects on target cells by stimulating the enzyme phospholipase-C, which catalyzes the hydrolysis of phosphoinositides to the intracellular second messengers diacylglycerol and inositol phosphates. The present study examined the roles of FSH and guanine nucleotide-binding proteins (G-proteins) in regulating the hydrolysis of phosphoinositides in Sertoli cells. Sertoli cell cultures prepared from 16- to 18-day-old rats were incubated for 24 h with myo-[2-3H] inositol to label endogenous phospholipids. Treatment of cells from 0.5-20 min with preparations of ovine FSH ranging in potency from 1-60 times that of NIH FSH S1 did not affect accumulation of inositol phosphates. Levels of total [3H]inositol phosphates [[3H]inositol mono-, di-, and triphosphates (IP, IP2, and IP3)] in FSH-treated cultures was 75-120% the levels in control cultures over the various time intervals studied. Addition of testosterone and the combination of testosterone plus retinoic acid, agents ...
Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite. (author).
Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite. (author).
Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite.
Previous studies have revealed marked differences in the incidence of leukemia between rats and mice exposed to 1,3-butadiene that do not appear to be readily explained on the basis of pharmacokinetics...Full Text Available
PurposeTo investigate the different components of full-field flash electroretinogram (ERG) responses in adult albino and pigmented rats at various time intervals following optic...Full Text Available
The radioactivity in tobacco leaves collected from 15 different regions of Greece and before cigarette production was studied in order to find out any association between the root uptake of radionuclides...Full Text Available
Airway conductance was measured in a body plethysmograph at different lung volumes before and after graded exercise. In 14 out of 19 patients, mostly asthmatics, airway conductance fell significantly...Full Text Available
Human gingival fibroblasts were challenged with Treponema pectinovorum and Treponema denticola to test three specific hypotheses: (i) these treponemes inducedifferent...Full Text Available
In an attempt to establish if cross protection can be induced by different strains of Haemophilus parasuis, three groups of 12 gnotobiotic pigs were immunized each with an aluminum hydroxide adsorbed...Full Text Available
Since it was introduced in the early 1940's, mutation breeding has been tested on many crops as modern plant breeding. Until now, more than seven hundred varieties have been developed by means of induced mutation, and many of them officially released and approved for registration. Hundreds of papers report the results of mutation breeding, and the characteristics of induced mutation in different kinds of crops were discussed for review purposes (Blixt and Gottschalk 1975, Gottschalk and Wolff 1983). Considering the results already obtained, it can be concluded that the kinds of induced mutation and their utilization vary from crop to crop. This paper summarizes and discusses the mutation characteristics and kinds on the induced mutants of leguminous plants that have been released.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
Nowadays, different research teams are engaged on experimental and theoretical studies having as main aim the evaluation of seismic performance of sheathed cold-formed steel frame structures. Although a relatively large number of experimental and theoretical studies are available, the development of useful tools for the seismic design should be improved. As an attempt to overcome this lack, this paper aims to present a structural design procedure that allows, through the definition of three design nomographs, the screw spacing and all the shear walls components to be obtained on the basis of linear dynamic or nonlinear static seismic analysis. In addition, a procedure for the prediction of the whole pushover response curve of sheathed cold-formed steel shear walls, which can be advantageou...
Several recent studies have documented that non-human primates can individuate objects according to property and/or kind information in much the same way as human infants do from around one year of age when they begin to acquire language. Some studies suggest, however, that only some properties are used for the individuation of food items: color, but not shape. The present study investigated whether these findings reveal a true competence problem with shape properties in the food domain or whether they merely reveal a performance problem (e.g., lack of attention to shapes). We tested 25 great apes (chimpanzees, bonobos and gorillas) in two food individuation tasks. We manipulated subjects? experience with differences in color and shape properties of food items. Results indicated (i) that a...
In support of the efforts to apply ceramics to advanced heat engines, a study is being performed of the performance of ceramics at the ring/cylinder interface of advanced (low heat rejection) engines. The objective of the study, managed by the Oak Ridge National Laboratory, is to understand the basic mechanisms controlling the wear of ceramics and thereby identify means for applying ceramics effectively. Attempts to operate three different zirconias, silicon carbide, silicon nitride, and plasma-sprayed ceramic coatings without lubrication have not been successful because of excessive friction and high wear rates. Silicon carbide and silicon nitride perform well at ambient temperatures with fully formulated mineral oil lubrication, but are limited to temperatures of 500F because of the lack of suitable liquid lubricants for higher temperatures.
Studies of the adsorption of oxides of sulfur and nitrogen, and their coadsorption, on black carbon in the form of n-hexane soot have been carried out by microgravimetry, EPR and FTIR spectroscopy over a wide range of experimental conditions. The mechanisms of adsorption of O{sub 2} and NO{sub 2} are entirely different, as reflected by adsorption isotherms, the behavior of carbon`s unpaired electrons, the spectral features of surface species formed, mass changes during adsorption-desorption cycles, and an essential lack of competition for surface sites. Significant effects of temperature, water, SO{sub 2} and NO{sub 2} concentration, O{sub 2}, simulated solar radiation, and the presence of trace metals, have been observed and interpreted.
Abstract: It seems that if abortion is permissible, then stem cell research must be as well: it involves the death of a less significant thing (an embryo rather than a fetus) for a greater good (lives saved rather than nine months of physical imposition avoided). However, I argue in this essay that this natural thought is mistaken. In particular, on the assumption that embryos and fetuses have the full moral status of persons, abortion is permissible but one form of stem cell research is not-the practice of creating embryos and then destroying them to extract cell material. Furthermore, I argue that the same is true on the assumption that embryos and fetuses have at least some moral status. I conclude that this form of stem cell research is permissible only if the embryos in question lack ...
Fragranced consumer products are pervasive in society. Relatively little is known about the composition of these products, due to lack of prior study, complexity of formulations, and limitations and protections on ingredient disclosure in the U.S. We investigated volatile organic compounds (VOCs) emitted from 25 common fragranced consumer products-laundry products, personal care products, cleaning supplies, and air fresheners-using headspace analysis with gas chromatography/mass spectrometry (GC/MS). Our analysis found 133 different VOCs emitted from the 25 products, with an average of 17 VOCs per product. Of these 133 VOCs, 24 are classified as toxic or hazardous under U.S. federal laws, and each product emitted at least one of these compounds. For ''green'' products, emissions of these c...
Several natural gas vehicles have been built as part of Ford's Alternative Fuel Demonstration Fleet. Two basic methods, compressed gas (CNG), and liquified gas (LNG) were used. Heat transfer danger and the expense and special training needed for LNG refueling are cited. CNG in a dual-fuel engine was demonstrated first. The overall results were unsatisfactory. A single fuel LNG vehicle was then demonstrated. Four other demonstrations, testing different tank weights and engine sizes, lead to the conclusion that single fuel vehicles optimized for CNG use provide better fuel efficiency than dual-fuel vehicles. Lack of public refueling stations confines use to fleet operations.
Sheltering, evacuation and distribution of stable iodine tablets are considered to be major early emergency actions aiming at diminishing the consequences after a release of radioactive materials from nuclear power plants into the air. Whether in real situations emergency managers will act accordingly is hard to predict. Uncertainties associated with these decisions are termed 'volitional' uncertainties. These uncertainties, however, cannot be assessed by expert judgements as they express the decision at stake in an emergency situation. Uncertainties on the times to implement countermeasures and on the times for the general population to respond to these measures can be assessed by experts, as they represent 'lack-of-knowledge' uncertainties. This paper describes the difference in approach of both types of uncertainties and shows the results of expert judgements on the latter type of uncertainties in early ...
Displacement Ventilation (DV) offers a great opportunity to improve indoor air quality while reducing the energy consumption compared to mixing ventilation. A frequent problem with displacement ventilation is however the draft discomfort caused by the cold air movement at foot level and excessive temperature difference between head and ankle. Despite numerous past studies, there is still a lack of detailed data regarding the velocity and temperature distribution inside DV jets. In this experimental study, measurements of the air velocity and temperature are performed in the DV jet produced by a flat wall-mounted DV diffuser, using a fine mesh focused on the 0.00-0.20 m height range. Two supply conditions are studied. Three planes of measurements are covered: the vertical longitudinal plane...
Although a large number of different organisations offer various forest education programmes within Germany, specific information (i.e., sectoral and programme content and provision at a state level) is lacking. This study used a survey of all 61 forest education organisations (43 respondents) in the state of North Rhine-Westphalia, Germany, to evaluate its forest education sector, with a specific focus on the organisations, demand for its services, forest educational programmes and framework conditions. Input from expert interviews was also used to develop recommendations. The study indicates that, especially with children as the main target group, many non-formal programmes are offered to support the formal environmental education sector and to promote leisure activities in the forest. Y...
The lower condition factors for two catfish species in water heated by effluents from APCo's Glen Lyn, Virginia plant as compared to control areas probably is not due to lack of food as evidenced by macroinvertebrate sampling and the fact that only 4.3 percent of the catfish stomachs were empty. Results suggested that young-of-the-year channel catfish were nonselectively eating food organisms present at both control and heated stations. The difference between stomach contents of flatheat catfish from the heated site and fauna available at that site indicated that fish were either moving out of the heated area to feed or were selectively feeding on organisms (particularly mayflies) which were in the substrate or drifted into the heated area. Stomach contents of the two species and distribution and abundance of the macroinvertebrate benthos community are detailed.
Experimental data on A-15 binary phases (the lattice parameter dependence on composition, phase diagrams, etc.) have been considered and the so-called ''compounds with A-15 structure'' are shown to be solid solutions of element substitution in the structure of A-15 type. Values of lattice parameter and atomic volume of A-15 modifications for 21 elements have been obtained (for Zr, W, Nb, Mo, V in particular). There has been shown the possibility of calculation of atomic volumes and lattice parameters of A-15 binary phases at the lack of direct experimental data. The essential role of atomic volume relations of different phases has been observed for the estimation of stability conditions of A-15 phase.
Experimental data on A-15 binary phases (the lattice parameter dependence on composition, phase diagrams, etc.) have been considered and the so-called ''compounds with A-15 structure'' are shown to be solid solutions of element substitution in the structure of A-15 type. Values of lattice parameter and atomic volume of A-15 modifications for 21 elements have been obtained (for Zr, W, Nb, Mo, V in particular). There has been shown the possibility of calculation of atomic volumes and lattice parameters of A-15 binary phases at the lack of direct experimental data. The essential role of atomic volume relations of different phases has been observed for the estimation of stability conditions of A-15 phase.
Concerning the gamma emitters, the only analysis on soils put in evidence the presence of cesium-137 ({sup 137}Cs), that does not come from the cyclotron functioning but from past man action as the Chernobylsk accident and the nuclear weapon tests in atmosphere. Independently of the functioning of the installation, we observe an increase of the ambient gamma radiation only near radioactive waste storage. It results of the storage of the former cyclotron elements. The induced increase is moderated because at 5 meters the values do not exceed the background noise. In relation with the functioning of the installation an increase of the ambient gamma radiation is noticed. Two causes are to considered: the release of radionuclides in atmosphere with gaseous effluents and the radiance of radiation sources inside the building. After the stopping of the installation (48 h at least), no increase of gamma radiation is observed. About the neutrons monitoring, the measures ...
Investigations into sexual differentiation and pheromone response in the fission yeast Schizosaccharomyces pombe are complicated by the need to first starve the cells of nitrogen. Most mating-related experiments are therefore performed on non-dividing cells. Here we overcome this problem by using two mutants that bypass the nutritional requirements and respond to the M-factor mating pheromone in rich medium. The first mutant lacks the cyr1 gene which encodes adenylate cyclase and these cells contain no measurable amounts of cAMP. When M-factor is added to a growing h+ cyr1- strain it causes a transient G1 arrest of cell division, transcription of mat1-Pm, and elongation of the cells to form shmoos. The second mutant contains the temperature-sensitive pat1-114 allele. At 30 degrees C this mutant was previously shown not only to bypass the nutritional signal but also to stop growing in a state derepressed for pheromone-controlled functions. We now report that an h+ ...
Persistent hepatitis C virus (HCV) infection affects 170 million people worldwide. Acute HCV infection is often asymptomatic, but many infected individuals develop persistent infections that may lead to development of end-stage liver diseases, including liver cirrhosis and hepatocellular carcinoma. Thus, an HCV vaccine that could significantly lower the chronicity rate would have a major impact on the disease burden. Unfortunately, HCV is a highly mutable virus, and escape mutations can undermine vaccine-induced virus-specific immunity. Also, HCV exists as multiple genotypes, and so genotype-specific vaccines might be required to achieve broad protection. Finally, vaccine development has been hampered by the lack of a small animal model and cell culture systems, but these are currently being established. Despite these obstacles, several vaccine candidates tested in the chimpanzee HCV model have shown some encouraging results.
In response to a heat shock, the yeast Saccharomyces cerevisiae undergoes a large increase in its resistance to heat and, by the induction of its recombinational DNA repair capacity, a corresponding increase in resistance to radiation. Yeast which lack mitochondrial DNA, mitochondria-controlled protein synthetic apparatus, aerobic respiration, and electron transport (rho/sup 0/ strain) were used to assess the role of O/sub 2/, mitochondria, and oxidative processes controlled by mitochondria in the induction of these resistances. We have found that rho/sup 0/ yeast grown and heat shocked in either the presence or absence of O/sub 2/ are capable of developing both radiation and heat resistance. We conclude that neither the stress signal nor its cellular consequences of induced heat and radiation resistance are directly dependent on O/sub 2/, mitochondrial DNA, or mitochondria-controlled protein synthetic or oxidative processes.
The CYP1A (EROD)-inducing potencies of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3minutes or feet,4,4minutes or feet,5-pentachlorobiphenyl (PCB126) and benzo(k)fluoranthene (B(k)F) were studied in avian embryo livers. TCDD and PCB126 proved to be much more potent as inducers in the chicken than in the other species examined. This finding is consistent with a considerably higher sensitivity of the chicken compared with a number of other avian species to the embryotoxic effects of these compounds. Furthermore, the relative potencies of the tested Ah receptor agonists as CYP1A inducersdiffered substantially between species. B(k)F and PCB126 showed similar induction potencies in domestic duck embryos, whereas PCB126 is much more potent than B(k)F in the chicken. Also, the potency of PCB126,relative to that of TCDD, was much lower in quail embryo liver in vitro than in chicken embryo liver. Thus, there ...
The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk oxides, the structure and ...
In-reactor testing of bolt-loaded compact tension specimens was performed in 360 C water to determine the irradiation-assisted stress corrosion cracking (IASCC) behavior of HTH Alloy X-750 and direct-aged Alloy 625. New data confirm previous results showing that high irradiation levels reduce SCC resistance in Alloy X-750. Heat-to-heat variability correlates with boron content, with low boron heats showing improved IASCC properties. Alloy 625 is resistant to IASCC, as no cracking was observed in any Alloy 625 specimens. Microstructural, microchemical and deformation studies were performed to characterize the mechanisms responsible for IASCC in Alloy X-750 and the lack of an effect in Alloy 625. The mechanisms under investigation are: boron transmutation effects, radiation-induced changes in microstructure and deformation characteristics, and radiation-induced segregation. Irradiation of Alloy X-750 caused significant ...
Full text of publication follows: Understanding the dynamic irradiation effects on silica glasses is important for developing the diagnostic systems used in fusion and fission environments. While fundamental defects having an un-pared electron such as the E' center have been extensively studied, the neutral oxygen deficiency defects have been insufficiently clarified for lack of the detection methods. The ion induced luminescence is one of the probes that can be used to detect non-paramagnetic defects, and to observe creation and annihilation behavior dynamically. In the present study, we examined the characteristics of the ion induced luminescence such as energy, fluence flux and temperature dependence of the luminescence efficiency to analyze damage process quantitatively. Samples of SiO2 glasses were commercially available fused and synthesized silica glasses, produced by Toshiba Ceramics, Co. Ltd.. A thin films of SiO2 ...
Genomic instability can be produced by ionising radiation, so-called radiation-induced genomic instability, and chemical mutagens. Radiation-induced genomic instability occurs in both germinal and somatic cells and also in the offspring of irradiated individuals, and it is characterised by genetic changes including chromosomal rearrangements. The majority of studies of trans-generational, radiation-induced genomic instability have been described in the male germ line, whereas the authors who have chosen the female as a model are scarce. The aim of this work is to find out the radiation-induced effects in the foetal offspring of X-ray-treated female rats and, at the same time, the possible impact of this radiation-induced genomic instability on the action of a chemical mutagen. In order to achieve both goals, the quantity and quality of chromosomal damage were analysed. In order to ...
BackgroundPoverty, lack of female empowerment, and lack of education are major risk factors for childhood illness worldwide. Microcredit programs, by offering small loans to poor...Full Text Available
DNA replication in Escherichia coli cells lacking protein HU was studied. HU has been suggested to be involved in the initiation of replication from in vitro studies. The isolated HU mutants, however,...Full Text Available
Background The objective of this study was to confirm provisional quantitative trait loci (QTL) for cocaine-induced locomotor activation, on chromosomes 1, 5, 6, 9, 12, 15, 16, 17, and 18, previously identified in the AXB/BXA recombinant inbred (RI) and AcB/BcA recombinant congenic (RC) strains of mice derived from A/J (A) and C57BL/6J (B6) progenitors. This was accomplished through a genetic analysis of cocaine-induced activity in an AxB6 F2 cross and a phenotypic survey across a panel of B6.A chromosome substitution strains (CSS) mice. Mice were tested for cocaine-induced activity, following administration of saline and cocaine (20?mg/kg), utilizing an open-field procedure. Results Among AxB6 F2 mice, differences in cocaine-induced activity were associated with loci on chromosome 1 (D1Mi...
We present a Hubble Space Telescope image of the FRII radio galaxy 3C 401, obtained at 1.6 microns with the NICMOS camera in which we identify the infrared counterpart of the brightest region of the radio jet. The jet has a complex radio structure and brightens where bending occurs, most likely as a result of relativistic beaming. We analyze archival data in the radio, optical and X-ray bands and we derive its spectral energy distribution. Differently from all of the previously known optical extragalactic jets, the jet in 3C401 is not detected in the X-rays even in a long 48ksec X-ray Chandra exposure and the infrared emission dominates the overall SED. We propose that the dominant radiation mechanism of this jet is synchrotron. The low X-ray emission is then caused by two different effects: i) the lack of any strong external photon field and ii) the shape of the electron distribution. This affects the location of the ...
The standards mapping methods are limited by the lack of information between surface measures and wells profiles. The cross well seismic survey has proven being an effective high-resolution method for reservoirs characterization due its high frequency band. In this work, a 2-D finite differences algorithm for numerical cross well seismic simulation was developed, based in the approach of 2nd order for the time derivatives and 4th order for the space derivatives. In relation to the imaging techniques, it was introduced a reverse time migration method based in the solutions of the wave equation in time for cross well seismic data by the method of the finite differences exclusively. The results of reverse time migration has showed that layers with 90 cm thickness for P-waves could be visualized in migrated sections with excellent resolution. The high frequency cross well seismic data combined with reverse time migration have ...
Continuous ambulatory peritoneal dialysis (CAPD) is a generally well-tolerated treatment. However, some patients exhibit such complications as to prevent the continuation of treatment. Peritonitis is the major problem, but the continuation of treatment may also be undermined by different complications, such as peritoneal leakage, hernia, catheter malfunctioning, and scrotal-penile edema; a careful investigation of the patient is always needed in such cases. From November 1985 to February 1990, we examined 20 patients, who had presented with different types of complications in the course of dialysis. Peritoneography demonstrated 3 cases of abdominal hernias, 2 cases of patency of the peritoneal-vaginal duct, and 2 cases of catheter obstruction. Peritoneal CT allowed the identification of leakage in 3 patients, while the combined use of the two techniques showed adhesions or pathologic peritoneal recesses in 7 cases. In 3 patients normal patterns ...
Three popular imaging methods were used to carry out seismic migration from the Alberta foothills: Kirchhoff integral, reverse-time and explicit finite-difference migration methods. The imaging comparisons of reverse-time, Kirchhoff and f-x post-stack depth migration leads to the following conclusions. All of the three migration methods can provide acceptable and well-imaged intermediate results on the simplest model. Post-stack migration was not very sensitive to the accuracy of the velocity field once a reliable structural stack was available. With respect to the imaging accuracy and calculation cost, the Kirchhoff migration method seemed to be superior to reverse-time and f-x migration algorithms because its results on different kinds of velocity cases were basically kept coherent and consistent with the velocity model given by Mobil. Because of the lack of an accurate velocity field, reverse-time migration was less ...
Three popular imaging methods were used to carry out seismic migration from the Alberta foothills: Kirchhoff integral, reverse-time and explicit finite-difference migration methods. The imaging comparisons of reverse-time, Kirchhoff and f-x post-stack depth migration leads to the following conclusions. All of the three migration methods can provide acceptable and well-imaged intermediate results on the simplest model. Post-stack migration was not very sensitive to the accuracy of the velocity field once a reliable structural stack was available. With respect to the imaging accuracy and calculation cost, the Kirchhoff migration method seemed to be superior to reverse-time and f-x migration algorithms because its results on different kinds of velocity cases were basically kept coherent and consistent with the velocity model given by Mobil. Because of the lack of an accurate velocity field, reverse-time migration was less ...
Ferritic/martensitic steel, modified 9Cr-1Mo steels have been used most extensively in the power generation industry throughout the world due to having superior high temperature properties such as high strength, creep resistance, and good microstructure stability. These steels are also the primary candidate for the RPVs(Reactor Pressure Vessels) of High Temperature Gas-Cooled Reactors. Currently, many studies has been conducted in laboratory-scale for mod. 9Cr-1Mo steels. However, there is a lack of the study on forged thick- section for RPVs. The differences in characteristics including the through thickness microstructure and mechanical properties between internal and external locations may occur during cooling after austenitization, because the thickness of RPVs is over about 200mm. Therefore, in order to use ferritic/martensitic steel as RPVs, a detailed assessment of the through thickness properties is needed. The purpose of this study is ...
Computer assisted energy-spectral analyses were obtained on EEG recordings of unilateral non-dominant hemisphere ECT-induced seizures using the different pre-ECT anesthetic agents methohexital (Brevital), Innovar, and ketamine (Ketalar). The previously postulated predominance of electrical energy over the stimulated (right) hemisphere early in ECT-induced seizures is confirmed. There appears to be marked reduction in total seizure energy with methohexital anesthesia, whereas ketamine anesthesia appears to be associated with increased overall seizure energy. The greatest right to left energy transfer during the seizure occurred with Innovar anesthesia. PMID:7172456
The results of theoretical and experimental investigations, describing the effect of ionizing radiation on wood and its main components and methods for production of wood-plastic composites by means of radiation-induced chemical modification are generalized. Domestic and foreign experience in their production is systematized; physico-mechanical characteristics of new material, simulation and calculation of irradiating devices, as well as calculation and experimental study of #gamma#-radiation attenuation both by wood material and by wood of different species are given. Gamma sources ("6"0Co isotope, a hot loop of a nuclear reactor) as well as electron accelerators are considered as ionizing radiation sources.
Nuclear reaction cross-sections for stable strontium and cesium isotopes, which were calculated by different approaches, are compared to available experimental data. Neutron and proton induced reaction cross-sections for the long-lived radionuclides [sup 90]Sr and [sup 137]Cs have been calculated in the energy range from 1 MeV to 10 GeV. Recommendations concerning cross-section calculations for strontium and cesium isotopes at intermediate and high energies are given. (orig.)
Characterization of high temperature superconducting film and bulk samples has been carried out using 2 MeV [alpha]-particle Rutherford backscattering, 2.4 MeV proton elastic scattering, 2.4 MeV proton-induced x-ray emission, 9 MeV proton induced [gamma]-ray emission and 100 MeV iodine elastic recoil detection analysis techniques. The objective was to compare different ion beam based techniques for: (i) compositional analysis; and (ii) consistency of the results obtained for samples prepared using similar preparation methodology. (author).
We consider light waves propagating clockwise and other light waves propagating counterclockwise around a closed path in a plane (theoretically with the help of stationary mirrors). The time difference between the two light propagating path orientations constitutes the Sagnac effect. The general relativistic expression for the Sagnac effect is discussed. It is shown that a gravitational wave incident to the light beams at an arbitrary angle will not induce a Sagnac effect so long as the wave length of the weak gravitational wave is long on the length scale of the closed light beam paths. The gravitational wave induced Sagnac effect is thereby null.
The electronic structure of the clusters (V/sub 3/Si/sub 4/)/sup 12 -/, (Nb/sub 3/Sn/sub 4/)/sup 12 -/(Mo/sub 3/Ge/sub 4/)/sup 15 -/ in crystalline V/sub 3/Si, Nb/sub 3/Sn, Mo/sub 3/Ge compounds is calculated by the Extended Hueckel method. The influence of different types of radiation induced defects on the density of states at the Fermi level (the anti-site defects, the displacement of atoms in linear chains, the vacancy-interstitial type defects) is considered.
The electronic structure of the clusters [V_3Si_4]"1"2"-, [Nb_3Sn_4]"1"2"-[Mo_3Ge_4]"1"5"- in crystalline V_3Si, Nb_3Sn, Mo_3Ge compounds is calculated by the Extended Hueckel method. The influence of different types of radiation induced defects on the density of states at the Fermi level (the anti-site defects, the displacement of atoms in linear chains, the vacancy-interstitial type defects) is considered. (author).
The shifts induced by equimolar mixture of typical lanthanide shift reagent such as 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octadionato europium with silver trifluoroacetate in /sup 1/H NMR spectra of aromatic hydrocarbons have been used for analytical purposes; the NMR determination of m- and p-xylenes in mixtures has been chosen as an example. The use has been made of the difference between induced shifts of methyl group signals in the /sup 1/H NMR spectra of m- and p-xylenes. The magnitude of induced shifts of methyl groups signal in m-xylene is always larger than that of p-isomer, irrespective of contents of m- and p-xylenes in mixture.
A 38 year old male dentist developed an oligodendroglioma of the left medial temporal lobe and parasellar region 12 years after radiotherapy with 6600 rads for acromegaly. The 30 cases of radiation-induced gliomas reported in the English literature are reviewed and analysed. The criteria for defining radiation-induced tumours of the central nervous system are proposed as follows: the tumour has a long quiescent ''latency period'', a location in the previously irradiated field, a verified histological difference from a primary condition, and does not arise from a primary condition associated with a genetic syndrome such as neurofibromatosis or tuberous sclerosis. The reported case fulfilled these criteria but appears to be the only reported radiation-induced oligodendroglioma.
According to empirical observations, some pattern formation phenomena in driven many-particle systems are more pronounced in the presence of a certain noise level. We investigate this phenomenon of fluctuation-driven ordering with a cellular automaton model of interactive motion in space and find an optimal noise strength, while order breaks down at high(er) fluctuation levels. Additionally, we discuss the phenomenon of noise- and drift-induced self-organization in systems that would show disorder in the absence of fluctuations. In the future, related studies may have applications to the control of many-particle systems such as the efficient separation of particles. The rather general formulation of our model in the spirit of game theory may allow to shed some light on several different kinds of noise-induced ordering phenomena observed in physical, chemical, biological, and socio-economic systems (e.g., attractive and ...
The nation's electric power system would be subject to induced surges in the event of a high altitude nuclear burst. The HEMP would be coupled to overhead power lines and cause severe overvoltage to components connected to the line. This paper discusses the design of pulsed power equipment needed to simulate this induced EMP. A facility is described which is capable of testing the vulnerability of components by applying appropriate voltage and current waveforms. The pulser can provide waveforms under a variety of test conditions to meet the requirements of different types of components. A 3-5 MV Marx pulser is described. It has the capability of generating a fast rising voltage followed by two distinct exponential decays. The testing of components, charged with their normal voltage is also described.
Laser-Induced Breakdown Spectroscopy was selected by NASA as part of the ChemCam instrument package for the Mars Science Laboratory rover to be launched in 2009. ChemCam's Laser-Induced Breakdown Spectroscopy instrument will ablate surface coatings from materials and measure the elemental composition of underlying rocks and soils at distances from 1 up to 10 m. The purpose of our studies is to develop an analytical methodology enabling identification and quantitative analysis of these geological materials in the context of the ChemCam's Laser-Induced Breakdown Spectroscopy instrument performance. The study presented here focuses on several terrestrial rock samples which were analyzed by Laser-Induced Breakdown Spectroscopy at an intermediate stand-off distance (3 m) and in an atmosphere similar to the Martian one (9 mbar CO{sub 2}). The experimental results highlight the matrix effects ...
Laser-Induced Breakdown Spectroscopy was selected by NASA as part of the ChemCam instrument package for the Mars Science Laboratory rover to be launched in 2009. ChemCam's Laser-Induced Breakdown Spectroscopy instrument will ablate surface coatings from materials and measure the elemental composition of underlying rocks and soils at distances from 1 up to 10 m. The purpose of our studies is to develop an analytical methodology enabling identification and quantitative analysis of these geological materials in the context of the ChemCam's Laser-Induced Breakdown Spectroscopy instrument performance. The study presented here focuses on several terrestrial rock samples which were analyzed by Laser-Induced Breakdown Spectroscopy at an intermediate stand-off distance (3 m) and in an atmosphere similar to the Martian one (9 mbar CO2). The experimental results highlight the matrix effects and the measurement ...
The IRG protein Irgm3 preserves cell survival during coxsackievirus B3 (CVB3) infection. However, the molecular mechanisms are not clear. Here, we examined the effect of Irgm3 expression on ER stress triggered by pharmacological agents or CVB3 infection. In Tet-On/Irgm3 HeLa cells, Irgm3 expression suppressed either chemical- or CVB3-induced upregulation of glucose-regulated protein78. Further, Irgm3 strongly inhibited the activation of both the PERK and ATF6 pathways of ER stress responses, which further led to the diminished phosphorylation of eIF2?, reduced cleavage/activation of transcription factor SREBP1 and attenuated induction of proapoptotic genes CHOP and GADD34. These data were further supported by experiments using Irgm3 knockout mouse embryonic fibroblasts, in which the ER stress induced by CVB3 was not relieved due to the lack of Irgm3 expression. In addition, the tunicamycin-triggered ER stress promoted the ...
The linear/supralinear behaviour of the TL dose response in LiF:Mg,Ti (TLD-100) and its dependence on ionisation density is a fairly unique phenomenon which cannot be explained by conventional atomic 'conduction band/valence band' kinetic models. The Track Interaction Model (TIM) provides the microscopic framework which, when coupled with other appropriate physical mechanisms (spatial localisation of traps and recombination centres, competing centres, variations in the capture cross sections with temperature, etc.) can be used to describe all the dominant features of the TL supralinearity of LiF:Mg,Ti and similar TL systems. The unique feature of the TIM applied to alpha particles is that it is an integral approach with only one free parameter, the average charge carrier migration distance in the luminescence recombination stage. Although the TIM provides a comprehensive description of the mechanisms underlying supralinearity in TLD-100, definitive unambiguous proof ...
The quantitative determination of oxide concentration by laser-induced breakdown spectroscopy is relevant in various fields of applications (e.g.: analysis of ores, concrete, slag). Calibration free laser-induced breakdown spectroscopy and the multivariate calibration are among the methods employed for quantitative concentration analysis of complex materials. We measured the intensity of neutral and ionized atomic emission lines of oxide materials by laser-induced breakdown spectroscopy and we modified the calibration free laser-induced breakdown spectroscopy method to increase the accuracy. The concentration of oxides was obtained by using stoichiometric relations. Sample materials were prepared from oxide powder (Fe{sub 2}O{sub 3}, MgO, CaO) by mixing and pressing. The concentration was 9.8-33.3 wt.% Fe{sub 2}O{sub 3}, 7.6-33.3 wt.% MgO and 33.3-81.2 wt.% CaO for different ...
Primary malignant lymphoma of the brain is a disease of unknown etiology, which is increasing in incidence and has an unfavorable prognosis. Despite the lack of specific changes on CT or MRI in most cases, these procedures may typically facilitate the diagnosis: A focal-enhancing mass with subependymal spread on CT or MRI and hyperattenuation on nonenhanced CT are the most reliable features in the diagnosis of primary malignant lymphoma of the brain. Peritumoral edema and mass effect are usually not prominent features. On unenhanced CT scans they usually appear homogeneously isodense to mildly hyperdense relative to the gray matter. On MRI these tumors are slightly hypointense on T1-weighted images and slightly hpyerintense on PD- and T2-weighted images relative to the gray matter. On CT and MRI enhancement is usually homogeneous. Contrast-enhanced MRI, with its multiplanar capability, lack of bone-induced artifacts, and ...
Mass and charge distributions of products from fission of sup(242m)Am induced by thermal neutrons have been investigated by means of the semiconductor spectrometry of ..gamma.. radiation from a mixture of non-separated fragment nuclei. Specimens of the fissible material have been irradiated in the vertical experimental channel of the research reactor then the measurements have been performed with calibrated semiconductor detectors. Three experiments with substantially different irradiation times have been performed to expand the nomenclature of the investigated fission products. The spectra of ..gamma.. radiation from the mixture of fission products, and time dependences of the counting rates at the total absorption peaks have been handled with computers. The obtained yields are compared with data of previous investigations performed with different experimental methods, as well as with the calculated one.
Passage through dams is a major source of mortality of anadromous juvenile salmonids because some populations must negotiate up to eight dams in Columbia and Snake rivers. Dams cause direct mortality when fish pass through turbines, but dams may also cause indirect mortality by altering migration conditions in rivers. Forebays immediately upstream of dams have decreased the water velocity of rivers and may contribute substantially to the total migration delay of juvenile salmonids. Recently, Coutant (2001a) suggested that in addition to low water velocities, lack of natural turbulence may contribute to migration delay by causing fish to lose directional cues. Coutant (2001a) further hypothesized that restoring turbulence in dam forebays may reduce migration delay by providing directional cues that allow fish to find passage routes more quickly (Coutant 2001a). Although field experiments have yielded proof of the concept of using induced ...
Delayed-neutron (DN) energy spectra following thermal neutron induced fission of /sup 239/Pu as a function of time after fission have been measured, using the beta-neutron time-of-flight (TOF) spectrometer at the University of Lowell. Thermal/epithermal neutrons were produced on the 5.5-MV Van de Graaff accelerator using the /sup 7/Li(p,n)/sup 7/Be reaction. Time spectra over the neutron energy range of 0.01-4.0 MeV were measured for seven different time intervals after fission, each interval containing varying contributions from the six delayed neutrons groups. The DN energy spectra following induced thermal fission of /sup 239/Pu are compared to those resulting from induced thermal fission of /sup 235/U for each of the seven delay time intervals. Decomposition of the measured spectra into six-group DN spectra was accomplished employing an iterative least-squares method, incorporating a constraint ...
The characteristics of defects induced by Si and Ga focused ion beam (FIB) implantation in n-GaAs have been investigated by means of deep-level transient spectroscopy (DLTS), C--V carrier profiling, and resistance measurements. The DLTS spectra of Si and Ga FIB implanted samples annealed at temperatures up to 500 /sup 0/C are apparently identical to one another and show three different electron traps with an activation energy between 0.25 and 0.6 eV. The resistance increases by more than five orders of magnitude by Si and Ga FIB implantation due to the induced defects. However, it is restored to initial values after annealing at 600 /sup 0/C, except for a sample of Ga implantation with a dose higher than 10/sup 14/ cm/sup 2/ . For annealing of induced defects, there are no intrinsic problems for FIB implantation with a dose lower than 10/sup 13/ cm/sup 2/ .
The characteristics of defects induced by Si and Ga focused ion beam (FIB) implantation in n-GaAs have been investigated by means of deep-level transient spectroscopy (DLTS), C--V carrier profiling, and resistance measurements. The DLTS spectra of Si and Ga FIB implanted samples annealed at temperatures up to 500 "0C are apparently identical to one another and show three different electron traps with an activation energy between 0.25 and 0.6 eV. The resistance increases by more than five orders of magnitude by Si and Ga FIB implantation due to the induced defects. However, it is restored to initial values after annealing at 600 "0C, except for a sample of Ga implantation with a dose higher than 10"1"4 cm"2 . For annealing of induced defects, there are no intrinsic problems for FIB implantation with a dose lower than 10"1"3 cm"2.
An initial draft of an environmental and natural resource strategy for the Asia Near/East region in the 1990's is presented. The report contains five chapters. Chapter I provides an analytic framework that links natural resources, their extent, quality, and management with economic growth in the region. Chapter II contains a more detailed description and analysis of key resource problems that are restricting economic growth and have a severe negative impact on standard of living and quality of life. The most serious of these are soil and water degradation; destruction of natural forests, wetlands, and coastal zones; inefficient energy use and industrial pollution; and lack of environmental services. Chapters III and IV describe 20 specific opportunities for working toward sustainable economic growth through protection and enhancement of the natural resource base. Opportunities for action were chosen on the basis of the urgency and importance of the ...
Radixin is a cytoskeletal protein that may be important in linking actin to the plasma membrane. Recent cloning of the murine and porcine radixin cDNAs revealed a protein highly homologous to ezrin and moesin. The authors have cloned and sequenced the human radixin cDNA and found the predicted amino acid sequence for the human protein to be nearly identical to those predicted for radixin in the two other species. By Southern analyses of Chinese hamster x human somatic cell hybrid DNA and of PCR products derived from hybrids, the coding gene (RDX) was mapped to 11q. Fluorescence chromosomal in situ hybridization with a cDNA plasmid further localized this gene to band 11q23. However, PCR amplification with [open quotes]radixin-specific[close quotes] primers on the hybrid DNA panel yielded an additional, very similar DNA sequence that was further characterized by direct sequencing of PCR products. This sequence represents a truncated version and the respective locus (RDXP2) was assigned ...
Lipid A from several strains of the N{sub 2}-fixing bacterium Rhizobium leguminosarum displays significant structural differences from Escherichia coli lipid A, one of which is the complete absence of phosphate groups. However, the first seven enzymes of E. coli lipid A biosynthesis, leading from UDP-GlcNAc to the phosphorylated intermediate, 2-keto-3-deoxyoctulosonate (Kdo{sub 2})-lipid IV{sub A}, are present in R. leguminosarum. We now describe a membrane-bound phosphatase in R. leguminosarum extracts that removes the 4{prime} phosphate of Kdo{sub 2}-lipid IV{sub A}. The 4{prime} phosphatase is selective for substrates containing the Kdo domain. It is present in extracts of R. leguminosarum biovars phaseoli, viciae, and trifolii but is not detectable in E. coli and Rhizobium meliloti. A nodulation-defective strain (24AR) of R. leguminosarum bovar trifolii, known to contain a 4{prime} phosphate residue on its lipid A, also lacks measurable ...
In this paper we study different effects of excited molecules on swarm parameters, electron energy distribution functions and gas discharge modeling. First we discuss a possible experiment in parahydrogen to resolve the discrepancy in hydrogen vibrational excitation cross section data. Negative differential conductivity (NDC) is a kinetic phenomenon which manifests itself in a particular dependence of the drift velocity on E=N and it is affected by superelastic collisions with excited states. A complete kinetic scheme for argon required to model excited state densities in gas discharges is also described. These results are used to explain experiments in capacitively and inductively coupled RF plasmas used for processing. The paper illustrates the application of atomic and molecular collision data, swarm data and the theoretical techniques in modeling of gas discharges with large abundances of excited molecules. It is pointed out that swarm experiments with excited ...
Previous work suggests that supplemental ascorbic acid (AA) may inhibit intestinal copper absorption by stabilizing the less absorbable cuprous state. The authors studied copper absorption in healthy men (age 19-32) fed a constant diet with different amounts of ascorbic acid supplements. The 6 men were confined to a metabolic unit for the entire 14 week study. The basal diet consisted of a 7 day rotating menu which provided an average of 2.1 mg Cu/d and was adequate in all other nutrients except AA (5 mg/d). The basal diet was supplemented with either zero, 60, or 600 mg of AA daily, added to grape juice and consumed at each meal. All feces were collected. Blood was taken weekly for monitoring AA and copper status. Copper absorption was determined by both balance and "6"5Cu stable isotope techniques. As determined by fecal Cu excretion, varying intakes of AA between 0.1 to 10 times the RDA had no significant effect on copper retention. This is consistent with the ...
To investigate the universality of the structure of interactions in different markets, we analyze the cross-correlation matrix ${\\mathbf C}$ of stock price fluctuations in the National Stock Exchange (NSE) of India. We find that this {\\em emerging} market exhibits strong correlations in the movement of stock prices compared to {\\em developed} markets, such as the New York Stock Exchange (NYSE). This is shown to be due to the dominant influence of a common market mode on the stock prices. By comparison, interactions between related stocks, e.g., those belonging to the same business sector, are much weaker. This lack of distinct sector identity in emerging markets is explicitly shown by reconstructing the network of mutually interacting stocks. Spectral analysis of ${\\mathbf C}$ for NSE reveals that, the few largest eigenvalues deviate from the bulk of the spectrum predicted by random matrix theory, but they are far fewer in number compared ...
Societatea Nationala Nuclearelectrica SA is the operator of the Cernavoda nuclear power plant and the second largest energy producer in Romania, after Hidroelectrica, ensuring 18% of the internal energy demand. The production of nuclear power differs from other industrial activities through the risks it involves and through the legacy it leaves to the future generations, i.e. the nuclear waste. Taking into account these considerations, public acceptance represents a constant preoccupation for nuclear companies around the world. Corporate Social Responsibility (CSR) is a new practice in the nuclear industry. After a long tradition of involvement in the life of the local community through the Social Program for Cernavoda, Nuclearelectrica has initiated a CSR campaign with the theme 'Welcome a tree in your family', addressed to pupils and high school students from Cernavoda. By this campaign, we aimed at creating relevance, not just green lots and to launch a chain of ...
The study of the {alpha}-particle energy distributions associated with ND and SD states in {sup 151,152}Dy has been carried out. The Dy isotopes were produced in the reaction {sup 37}Cl+{sup 123}Sb at 191 MeV via the ({alpha}5n) and ({alpha}4n) channels, respectively. In {sup 151}Dy the {alpha}-particle energy distributions associated to ND and SD are very different from each other, both at the low and high energy sides inducing a difference of 3 MeV in the {alpha}-particle mean energy. In {sup 152}Dy the situation is different; the {alpha}-particle spectral shapes are similar and a difference in the {alpha}-particle mean energy of only 0.7 MeV is deduced. A description in terms of energy localization of entry states is given. (orig.)
Aerial lines or cables, as one mainly energy transport path of electronic system when illuminated by HEMP, has been often modeled by field-to-transmission line model. However, in many cases, authors too often encounter some confusing statements to the lines effects during experimental procedure. The aim of this paper is to present and discuss these cases, such as the electromagnetic environment above the ground plane, the contribution of the different electromagnetic field component to the induced current and voltage, variations of the load current for different line heights and ground conductivities etc. (authors)
A finite three-dimensional layer-by-layer photonic crystal with planar defects in a layer is shown to drastically modify the spontaneous emission rate of an embedded dipole. Finite-difference time-domain calculations with one quarter symmetric boundary condition and perfectly matched layer demonstrate the strong enhancement effects induced by the cavity resonance of defect modes and band-edge resonant modes. Simulation shows that the emission spectra are quite different when the position or polarization of the dipole is changed. Moreover, the extraction efficiency is calculated to observe the percentage of light leakage through a substrate.
We entertain the idea that a suitable background of cold (very low momentum) pseudoscalar particles or condensate, may trigger a background that effectively generates Lorentz-invariance violation. This aether-like background induces a Chern-Simons modification of QED. Physics is different in different frames and, in the rest frame of the pseudoscalar background, high momentum photons can decay into pairs. The threshold for such decay depends quadratically on the rest mass of the particles. This mechanism could explain in a natural way why antiprotons are absent in recent cosmic ray measurements. A similar signal could be used as a probe of pseudoscalar condensation in heavy ion collisions.
Radiation hardening and radiation-induced chromium (Cr) depletion were related to intergranular stress corrosion cracking (IGSCC) response among various stainless steels (SS). Available data on neutron-irradiated materials were analyzed and correlations developed between fluence, yield strength, grain-boundary Cr concentration, and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in the critical fluence (0.2 neutrons/cm"2 to 2.5 x 10"2"1 neutrons/cm"2) for IGSCC were documented. Variability often was consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence for most heats, suggesting a possible role for radiation-induced hardening (and microstructure) on cracking. However, isolated heats revealed a wide range of yield strengths (450 MPa to 800 MPa) necessary to promote IGSCC which could ...
BackgroundThe Ras and Notch signaling pathways are frequently activated during development to control many diverse cellular processes and are often dysregulated during tumorigenesis....Full Text Available
This study evaluated the heat strain induced by six configurations of a new modular body armor (MBA) design. Tests were conducted in two environments differing only by wind speed. The environments were 40 deg C (104 deg F), 20% rh, wind speeds 1.0 msec-1 ...
PurposeTo describe clinical data and to characterize mutations in the transforming growth factor beta-induced (TGFBI) gene in patients from three unrelated Chilean...Full Text Available
The three mammalian transforming growth factor (TGF)-β isoforms (TGF-β1, TGF-β2, and TGF-β3) differ in their putative roles in radiation-induced fibrosis in intestine...Full Text Available
We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that TK6 has a reduced ...
Energy and angular double differential cross-section data of fragments by tens of MeV neutron or proton are important to evaluate dosimetry and radiation effect in devices or instruments, since fragments cause a large local ionization. Up to now, experimental data of the fragment production are very scarce due to experimental difficulties of fragment detection. A bragg curve spectrometer (BCS) for fragment measurement is a gridded-ionization chamber that identify fragments on the basis of the difference of Bragg peak value. The BCS was fabricated to adopt for fragment measurement in neutron-induced reactions and tested with a charged-particle beam and then applied to a neutron field successfully. The structure of BCS is a cylindrical gridded ionization chamber, and filled with a Ar + 10% CH{sub 4} gas at a pressure of 2.7 x 10{sup 4} Pa. To confirm the performance of BCS, the following tests were performed: 1) the saturation property by using ...
Autophagy is an intracellular recycling route in eukaryotes whereby organelles and cytoplasm are sequestered in vesicles, which are subsequently delivered to the vacuole for breakdown. The process is induced by various nutrient-responsive signaling cascades converging on the Autophagy-Related1 (ATG1)/ATG13 kinase complex. Here, we describe the ATG1/13 complex in Arabidopsis thaliana and show that it is both a regulator and a target of autophagy. Plants missing ATG13 are hypersensitive to nutrient limitations and senesce prematurely similar to mutants lacking other components of the ATG system. Synthesis of the ATG12-ATG5 and ATG8-phosphatidylethanolamine adducts, which are essential for autophagy, still occurs in ATG13-deficient plants, but the biogenesis of ATG8-decorated autophagic bodies does not, indicating that the complex regulates downstream events required for autophagosome enclosure and/or vacuolar delivery. Surprisingly, levels of the ...
Significant ion irradiation during film growth is required for the formation of cubic boron nitride (cBN) films. Meanwhile, a huge level of intrinsic stress possibly induced by the ion bombardment has been frequently reported to result in cracking and/or lack of adhesion of deposited cBN films. The present work has been performed to investigate the interfacial and/or the buffer layer structures with better matching to the cBN film by relaxation of the film stress using ion-beam-assisted deposition (IBAD). Boron nitride films have been synthesized on Si(100) wafer and tungsten carbide (WC) substrates by depositing boron vapor under simultaneous bombardment with nitrogen ions and nitrogen-argon mixture ions in the energy range of 0.5-10 keV. Cubic BN films with enhanced tribological properties have been explored by inserting a BN layer with various B/N compositions as a controlled buffer at the interface. Significant relaxation of the film stress ...
The spectral characteristics of the Cherenkov radiation have been evaluated and converted to equivalent retinal irradiance from external sources. On the basis of the conversion, electron fluxes have been estimated for 2-sec recovery times from flashblindness. The electrons are assumed to have energies greater than 6 MeV and to be delivered in one or more bursts of 1 microsecond each over 1 sec. It is important to note that very little data exists on recovery times as short as 2 sec for either photopic and scotopic conditions. This situation is a direct result of the lack of definition of the critical tasks and their sensitivity to an interruption of background adaptation. The Cherenkov radiation produced within the eye by relativistic electrons can be compared to light from external sources by the relationships: 1 rad approx. = 4.6 scotopic td-sec and 1 rad approx. = 0.55 photopic td sec. Based on these conversion factors, the following estimates can be derived by ...
Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding pocket in a pH-dependent fashion and (ii) ...
Current trends in nuclear power generation (and particularly in pressurized water reactors) are toward plant life extension and extended fuel burnup. A higher heat generation rate can induce local boiling regimes at the fuel rod surface in the hottest channels of the core, which can strongly modify the chemical environment of the cladding and influence the oxidation rate of zirconium alloys. Tests performed in out-of-pile loops under severe chemical and thermal-hydraulic conditions (nucleate boiling, higher lithium contents compared to PWRs) reveal two important phenomena: an increase of the oxidation rate of Zircaloy-4 cladding materials in 'high' lithiated environments; an enrichment of the chemical additives in the primary water (boron, lithium) at the surface of the cladding under nucleate boiling conditions. The latter phenomenon, also called 'hideout effect', is mainly controlled by some thermal hydraulic parameters such as bubble diameters and nucleation ...
We present theoretical calculations for the production of the long-lived isomers: {sup 121m}Sn (11/2-, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider mainly (n,2n) production modes, but also (n,n{sup {prime}}) and (n,{gamma}) where necessary, and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be ...
According to the LeChatelier-Braun principle, when a closed quiescent system initially in an equilibrium or unstressed steady state is subjected to an externally imposed ``stress'' it responds in a manner tending to alleviate that stress. Use of this entropically based qualitative rule, in combination with the notion of Maxwell thermal stresses existing in nonisothermal gases and liquids, enables one to (i) derive Maxwell's thermal-creep boundary condition prevailing at the boundary between a solid and a fluid (either gas or liquid) and (ii) rationalize the phenomenon of thermophoresis in liquids, for which, in contrast with the case of gases, an elementary explanation is currently lacking. These two objectives are achieved by quantitatively interpreting the heretofore qualitative LeChatelier-Braun notion of stress in the present context as being the fluid's stress tensor, the latter including Maxwell's thermal stress. In effect, thermophoretic particle motion is ...
In this work we report a study of the induced changes in structure and corrosion behavior of martensitic stainless steels nitrided by plasma immersion ion implantation (PI"3) at different previous heat treatments. The samples were characterized by x-ray diffraction and glancing angle x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and potentiodynamic measurements. Depending on the proportion of retained austenite in the unimplanted material, different phase transformations are obtained at lower and intermediate temperatures of nitrogen implantation. At higher temperatures, the great mobility of the chromium yields CrN segregations like spots in random distribution, and the #alpha#"'-martensite is degraded to#alpha#-Fe (ferrite). The nitrided layer thickness follows a fairly linear relationship with the temperature and a parabolic law with the process time. The corrosion resistance ...
Mycosis fungoides (MF) in deep-seated lymph nodes, spleen or liver appears to be associated with a lack of response of the disease to topical external therapy. Fourteen patients with mycosis fungoides...Full Text Available
Periventricular white matter injury (PWMI), is the leading cause of chronic neurologic injury among survivors of preterm birth. The hallmark of PWMI is hypomyelination and a lack of mature,...Full Text Available
Orphan G protein-coupled receptors (GPCRs) are receptors lacking endogenous ligands. Found by molecular biological analyses, they became the roots of reverse pharmacology, in which receptors are attempted...Full Text Available
The physical demands of performing on musical instruments can cause pain, sensory loss, and lack of coordination. Five cases illustrate common problems. Knowledge of the interaction between the technique...Full Text Available
Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease with major morbidity and mortality. Therapeutic management is difficult, due to lack of conclusive data and individual disease...Full Text Available
The cause of the female urethral syndrome has previously been obscure, as it has been associated by definition with a lack of objective findings but a plethora of subjective complaints of retropubic...Full Text Available
... is reduced: 1) by lack of oxygen, 2) in hypercapnia associated with closed rooms or tents, 3) by use of sleeping drugs, antipyretics, insulin, and 4 ...
Based on their interesting properties, metal nanoparticles show the potential as an analytical tool in electronic (Burmeister et al. 2004), optical (Yguerabide and Yguerabide 1998), and catalytic applications (Liu 2006). Their characteristics depend on the composition, shape, and size of the single particles. These various properties are utilized in many different approaches such as optics, magnetics (Lang et al. 2007), and laser technology (Csaki et al. 2007). We investigated an alternative method for the synthesis of nanoparticles. In this case, an enzyme, horseradish peroxidase, induces a silver deposition and replaces a metal nanoparticle as the reaction seed. Depending on the reaction time, we could obtain particles in a range of few nanometers up to more than 250 nm. For a better understanding of the enzymatic silver deposition process, the silver particles produced by this process were analyzed by SEM, TEM, and atomic force microscopy ...
PURPOSE: To investigate differences in cost of endovenous laser therapy (EVLT) using a top-down approach derived from the Annual Report versus a clinically orientated, bottom-up approach at a single hospital. METHODS: Information was obtained from: the day-case activity Service Line Report (SLR) income statement for general surgery, comparative data from the National Audit Commission, reference costs from the hospital finance department on 69 patients and calculations on individual treatment times and session slots (2 EVLT's per 3.5 hr session) on 37 consecutive patients. Duration of treatment, consumables (over #3) and staff pay were also recorded. Overheads were estimated at 15% and adjustments were made based on location and length of stay. RESULTS: Using a top-down approach with SLR data the total cost of EVLT was estimated at #963.78 per treatment after adjustments for services and consumables. This compares with #1,073.34 using national data. The hospital ...
During the past year, further studies on mAChR were conducted. These studies included verification of the difference in pituitary distribution based on ligand charge. The pituitary localization of TRB. A neutral mAChR ligand, was verified. The lack of QNB blockade of TRB uptake was tested by blockage with scopolamine, another mAChR antagonist and by testing the effect in a different strain of rat. Neither scopolamine or change of rat strain had any effect. We concluded that TRB uptake in pituitary is not a receptor-mediated process. Further studies were conducted with an additional quaternized mAChR ligand: MQNB. Pituitary localization of MQNB, like MTRB, could be blocked by pretreatment with QNB. We have tentatively concluded that permanent charge on a mAChR antagonist changes the mechanism of uptake in the pituitary. Time course studies and the effects of DES on myocardial uptake are reported. A brief report on ...
The proposed ASHRAE/IES Standard 90.1-1989R contains updated requirements for pipe insulation thicknesses developed on the basis of technical and economic principles. These requirements were determined based on computer simulations of the annual energy loss through the insulation, first cost assumptions for the insulation, and economic assumptions of discount rate and energy escalation rate. In later work, the same tools were used to analyze the sensitivity of the cost-effective insulation level for piping insulation to variations in operating hours, ambient temperature, fluid temperature, and economic assumptions. These analyses were carried out using cost data for pipe insulation averaged across several sources. The results of the sensitivity study showed that system operating hours is a critical parameter in determining the cost-effective pipe insulation thicknesses. Although there is a lack of reliable sources of typical operating hour data for heating systems, ...
DFNA5 was first identified as a gene causing autosomal dominant hearing loss (HL). Different mutations have been found, all exerting a highly specific gain-of-function effect, in which skipping of exon 8 causes the HL. Later reports revealed the involvement of the gene in different types of cancer. Epigenetic silencing of DFNA5 in a large percentage of gastric, colorectal and breast tumors and p53-dependent transcriptional activity have been reported, concluding that DFNA5 acts as a tumor suppressor gene in different frequent types of cancer. Despite these data, the molecular function of DFNA5 has not been investigated properly. Previous transfection studies with mutant DFNA5 in yeast and in mammalian cells showed a toxic effect of the mutant protein, which was not seen after transfection ...
The distribution profiles of the chemical structural changes induced in low density polyethylene(LDPE) irradiated by various ion-beams were obtained by micro-FT-IR measurement. Predominant species induced by ion-beam irradiation were trans-vinylene, hydroxyl group and carbonyl group. It was found that the depth profiles of these species resemble the Bragg curve, but they are rather different from the depth profile of the stopping power calculated by TRIM code. The terminal of the chemical reaction was observed to be deeper than the range calculated by TRIM code for all ion particles. This suggests that the energy profile in the region which the energy of the ion particle becomes lower is very complicated. (author).
In this study polycrystalline specimens of as-cast DyCu with B2 crystal structure were compressed to different strains at room temperature to test if stress-induced phase transformation and twinning occur during deformation. In these tests DyCu exhibited high ductility with plastic strain as high as 35% and ultimate compressive strength of ~790MPa. X-ray diffraction and transmission electron microscopy (TEM) showed no indications that DyCu had undergone stress-induced phase transformation or twinning. -type dislocations have been observed to play an important role for imparting the ductile behavior. TEM analyses showed the presence of second phases, Dy2O3 and DyCu2 within the DyCu. The mechanisms of ductility and impurity phase formation are discussed.
The cross section and activity profile of different radioisotopes produced by #alpha#-induced nuclear reaction on natural zirconium, have been obtained by stacked foil activation using 40 MeV #alpha#-particles from Variable Energy Cyclotron (VEC) machine at Calcutta. The activity profile would be used to study the surface loss of zircaloy materials of engineering components by thin layer activation (TLA) technique. Generally, isotopes with suitable #gamma#-rays and long half-lives are the most useful in TLA technique, e.g., "9"2Nb, "9"5"gNb and "9"5Zr. (author). 2 refs., 1 tab.
The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could ...
Abstract Strains of Pseudomonas syringae are effective in controlling postharvest diseases of citrus fruits, and antagonistic activity has been correlated with in vitro production of lipodepsipeptides. Additionally, biocontrol agents can induce a range of defence mechanisms of resistance in citrus tissue that result in a broad spectrum of metabolic modifications, such as systemic acquired resistance, induced systemic resistance and production of reactive oxygen species. The aim of this study was to evaluate the expression of syringomycin (syrB1) and syringopeptin (sypA) synthetase genes from P.syringae pv. syringae biocontrol strains in vitro on different culture media and in vivo on citrus fruits (Citrus sinensis cv. Tarocco) during the interaction with Penicillium digitatum by quantitati...
Dissolved microcystins (MCs) are regularly present in water dominated by microcystin-producing, bloom-forming cyanobacteria. In vitro experiments with environmentally feasible concentrations (5 ? 10?7 M) of the three most common microcystins, MC-LR, MC-RR, and MC-YR, revealed that they influence the metabolism of different representative phytoplanktons. At light intensities that are close to the cyanobacterial bloom environment (50??mol m?2 s?1), they produce morphological and physiological changes in both microcystin-producing and -nonproducing Microcystis aeruginosa strains and also have similar effects on the green alga Scenedesmus quadricauda that is frequently present in cyanobacterial blooms. All three microcystin variants tested induce cell aggregation, increase in cell volume, and ...
The radiation induced reactions in LDPE in the presence of phenolic type antioxidants have been studied. It was shown that various antioxidants can influence the polyethylene network formation and the radical yield in different ways. The dependence of network structure on absorbed doses was determined by gel analysis, hot-set test and extraction of antioxidants for samples irradiated with accelerated electrons. It was found that the antioxidants eluted from polyethylene in higher percentage influence polymer crosslinking to a smaller degree. The ESR studies of #gamma#-irradiated blends of polyethylene with antioxidant indicate the presence of alkyl and phenoxyl radicals. The role of antioxidant molecules on radiation induced reactions in polyethylene-antioxidant systems is considered. The correlation between the network structure and the type of additive in polyethylene is also discussed. (author).
Maintenance of genomic integrity in embryonic cells is pivotal to proper embryogenesis, organogenesis and to the continuity of species. Cultured mouse embryonic stem cells (mESCs), a model for early embryonic cells, differ from cultured somatic cells in their capacity to remodel chromatin, in their repertoire of DNA repair enzymes, and in the regulation of cell cycle checkpoints. Using 129XC3HF1 mESCs heterozygous for Aprt, we characterized loss of Aprt heterozygosity after exposure to ionizing radiation. We report here that the frequency of loss of heterozygosity mutants in mESCs can be induced several hundred-fold by exposure to 5-10Gy of X-rays. This induction is 50-100-fold higher than the induction reported for mouse adult or embryonic fibroblasts. The primary mechanism underlying the...
Ferrite of system, namely Ni_1_-_xZn_xFe_2O_4 with x = (0.0, 0.2, 0.4, 0.6, 0.8, 1.0), have been prepared by solid state reaction to investigate the effect of gamma rays irradiations using Co"6"0 source on the cation distribution, structural and magnetic properties. The unirradiated and irradiated samples were then subjected to characterization techniques such as X-ray diffraction, magnetization and AC susceptibility. The results of these characterizations are found to be different for irradiated from that of the pristine sample. The modifications in respect of irradiated samples are explained in terms of the ion-induced disorder. The important result of #gamma#-irradiation on the cation distribution, structural and magnetic properties is the change of ratio Fe"2"+/Fe"3"+. Possible reasons on the results are proposed.
We report on recent studies of the effects of 50 keV focused ion beam (FIB) exposure on MOS transistors. We demonstrate that the changes in value of transistor parameters (such as threshold voltage, V{sub t}) are essentially the same for exposure to a Ga+ ion beam at 30 and 50 keV under the same exposure conditions. We characterize the effects of FIB exposure on test transistors fabricated in both 0.5 {micro}m and 0.225 {micro}m technologies from two different vendors. We report on the effectiveness of overlying metal layers in screening MOS transistors from FIB-induced damage and examine the importance of ion dose rate and the physical dimensions of the exposed area.
Electrostatic fields of the order of 1 V/Angst, as they occur at field emission tips, are comparable to those experienced by valence electrons in atoms and molecules. Such fields are strong enough to induce a significant redistribution of the valence charge in chemical bonds. In this work we investigate the effects on the electronic properties of a single adatom on a metal surface induced by the presence of an electrostatic field. In particular we present the results of a full ab initio DFT calculation, within the embedding method, of the CCV Auger spectra of Si and Mg atoms in and on a jellium-Ag host. Differently from impurities in bulk, Auger spectral profiles of adsorbates on metal surfaces can show notable modifications due to the applied electric field.
An important aspect of ecosystem sustainability is the ability to withstand and recover from disturbance or stress. In this study, we investigated the effect of a heat-disturbance on soil microbial biomass, microbial activity in response to the addition of organic acid (malate), and microbial community structure in a laboratory experiment. The soils investigated were from a jarrah (Eucalyptus marginata) forest that had undergone rehabilitation following bauxite mining 12 years previously. Soils from a full factorial of two field treatments; contour ripping induced micro-topography (mound or furrow) and prior exposure to prescription fire (burnt or non-burnt), were sampled and found to exhibit treatment-dependent differences in soil biological and chemical properties. Exposure of soil micro...
Abstract Epstein-Barr virus (EBV), which infects not only B cells, but also T cells and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, the proteasome inhibitor bortezomib was reported to induce apoptosis of EBV-transformed B cells. We evaluated the killing effect of this proteasome inhibitor on EBV-associated T lymphoma cells and NK lymphoma cells. First, we found that bortezomib treatment decreased the viability of multiple T and NK cell lines. No significant difference was observed between EBV-positive and EBV-negative cell lines. The decreased viability in response to bortezomib treatment was abrogated by a pan-caspase inhibitor. The induction of apoptosis was confirmed by flow cytometric assessment of annexin V staining. Additionally, cleavage o...
The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.
Calculating work-function modifications for flat-lying conjugated molecules on extended metal surfaces using density functional theory (DFT) is an extremely resource intensive task. This prevents fast screening of new molecules for their potential to optimize metal work functions for good electron or hole injection in organic electronic devices. We present a semi-classical model, which avoids that problem. This is achieved by identifying the dominant processes occurring at the interface between metal and adsorbate in the pinning-regime, which are then parameterizing their description using band-structure DFT calculations for a small training set With the resulting interdependent equations at hand, only simple gas-phase calculations are needed to predict the work-function changes induced by new molecules. The model is tested for ten molecules on three different metal surfaces, where it shows excellent agreement with photoelectron spectroscopy ...
To determine a rat strain appropriate for carcinogenicity testing of FYX-051, a xanthine oxidoreductase inhibitor, we performed a 4-week oral toxicity study by administering 0.3, 1 and 3 mg/kg, and 1, 3 and 10 mg/kg of FYX-051 to male Sprague-Dawley (SD) and Fischer (F344) rats, respectively. Histopathology revealed that the degree of FYX-051-induced nephropathy was 3-fold stronger in SD rats than in F344 rats. Our previous study demonstrated that the key factor of species differences in FYX-051-induced nephropathy is purine metabolism. This observation led us to examine the involvement of purine metabolism in differences among two strains of rats. However, purine metabolism was proven not to be implicated as an important factor. Subsequently, other factors responsible for the strain differences were examined. FYX-051-induced increases in plasma xanthine ...
In this study, free electron laser (FEL) with selective wavelength was used to induce structure changes of biomolecules, which were characterized by FTIR spectroscopy. For understanding of the interactions between FEL and biomolecules as well as biological tissues, the biomolecules investigated are ATP, ADP, AMP, t-RNA, D-ribose and the complex of SmCl_3-D-ribose. Their FTIR spectra before and after irradiation of FEL show molecular structure variations of the samples after irradiation of FEL, especially the rearrangement of their hydrogen bond networks. Along with the various irradiation wavelengths, irradiation time and molecular structures, the changes after irradiation are different for these molecules. In the FTIR spectra after irradiation, the phenomenon that the bands split into several peaks indicates the existence of several structures, conformations and configurations, which may be prompted by multiple photons process ...
We present a fully relativistic formalism for describing neutrino-induced $\\Delta$-mediated single-pion production from nuclei. We assess the ambiguities stemming from the $\\Delta$ interactions. Variations in the cross sections of over 10% are observed, depending on whether or not magnetic-dipole dominance is assumed to extract the vector form factors. These uncertainties have a direct impact on the accuracy with which the axial-vector form factors can be extracted. Different predictions for $C_5^A(Q^2)$ induce up to 40-50% effects on the $\\Delta$-production cross sections. To describe the nucleus, we turn to a relativistic plane-wave impulse approximation (RPWIA) using realistic bound-state wave functions derived in the Hartree approximation to the $\\sigma$-$\\omega$ Walecka model. For neutrino energies larger than 1 GeV, we show that a relativistic Fermi-gas model with appropriate binding-energy correction produces ...
Theoretical interpretation of fast-charged-particle spectra, observed in the #alpha#-particle-induced reactions on the s-d shell nuclei (A = 24-28), in terms of the Intranuclear Cascade Model and the GDH exciton model (ALICE) is presented. The de-excitation of the excited residual nuclei is accounted for by the evaporation process. The theoretically predicted fast-proton and #alpha#' spectral shapes compare reasonably well with the corresponding measured spectra. However, the magnitude depends critically (as expected) on the reaction cross section employed by the model. As a first step to improve the model predictability of the reaction products, a closer look at the calculation of the #alpha#-particle reaction cross sections was undertaken. A microscopic approach using the optical theorem of Glauber's theory was employed to estimate the #alpha#-induced reaction cross sections for the light target nuclei under consideration. The calculated ...
Hole mobility changes under uniaxial and combinational stress in different directions are characterized and analyzed by applying additive mechanical uniaxial stress to bulk Si and SiGe-virtual-substrate-induced strained-Si (s-Si) p-MOSFETs (metal-oxide-semiconductor field-effect transistors) along (110) and (100) channel directions. In bulk Si, a mobility enhancement peak is found under uniaxial compressive strain in the low vertical field. The combination of (100) direction uniaxial tensile strain and substrate-induced biaxial tensile strain provides a higher mobility relative to the (110) direction, opposite to the situation in bulk Si. But the combinational strain experiences a gain loss at high field, which means that uniaxial compressive strain may still be a better choice. The mobility enhancement of SiGe-induced strained p-MOSFETs along the (110) direction under additive uniaxial tension is ...
It is one of the most important subjects to estimate the flow-related stability of the heat exchanger tubes. A large scale model steam generator has been developed to verify the stability of the tubes in the Japanese PWR steam generators for the two-phase flow-induced vibration and to accumulate related technical data of thermal-hydraulic and flow-induced vibration of U-bend tube bundle. The model steam generator has 230 U-bend tubes of 46 different radius and 5 columns for each of practical diameter and material, and the anti vibration bars are inserted into each spacing between tube arrays. The freon R123 has been used as the secondary side fluid in stead of water-steam two-phase. In the test, void fraction and interfacial velocities in U-bend and straight tube-bundle are measured with bi-optical probes, and vibration responses of some selected tubes are measured with strain gauges and accelerators. It is verified that ...
This paper reports regulation of hypoxia inducible factor-1 ? (HIF-1 ?)in hepatoma cells by irradiation. Cobalt chloride (CoCl2), a chemical mimic agent for hypoxia research, was utilized to induce the stable expression of HIF-1 ? in HepG2 cells. The HepG2 cells were irradiated to different doses to observe the changes of HIF-1 ?. The level of intracellular reactive oxygen species (ROS) was assayed by fluorescent microscope and flow cytometry (FCM). The results showed that there were obvious changes in expression of HIF-1 ? after HepG2 cells exposed to radiation, and the changes were positively related with the irradiation dose from 1 Gy to 5 Gy. Moreover, contents of incellular ROS were negatively correlated with above levels of HIF-1 ? from 1 Gy to 3 Gy. The results indicate that irradiation may enhance hypoxic cells HIF-1 ?, and the reduction of intracellular ROS can contribute to the regulation of ionizing radiation on ...
The compositions of the Earth's crust and mantle, and those of the Moon and Mars, are relatively well known both isotopically and elementally. The same is true of our knowledge of the asteroid belt composition, based on meteorite analyses. Remote measurements of Venus, the Jovian atmosphere, and the outer planet moons, have provided some estimates of their compositions. The Sun constitutes a large majority, > 99%, of all the matter in the solar system. The elemental composition of the photosphere, the visible 'surface' of the Sun, is constrained by absorption lines produced by particles above the surface. Abundances for many elements are reported to the {+-}10 or 20% accuracy level. However, the abundances of other important elements, such as neon, cannot be determined in this way due to a relative lack of atomic states at low excitation energies. Additionally and most importantly, the isotopic composition of the Sun cannot be ...
An important unresolved issue in outcomes analysis for lung complications is the effect of poor or completely lacking heterogeneity corrections in previously archived treatment plans. To estimate this effect, we developed a novel method based on Monte Carlo (MC) dose calculations which can be applied retrospectively to RTOG/AAPM-style archived treatment plans (ATP). We applied this method to 218 archived nonsmall cell lung cancer lung treatment plans that were originally calculated either without heterogeneity corrections or with primitive corrections. To retrospectively specify beam weights and wedges, beams were broken into Monte Carlo-generated beamlets, simulated using the VMC++ code, and mathematical optimization was used to match the archived water-based dose distributions. The derived beam weights (and any wedge effects) were then applied to Monte Carlo beamlets regenerated based on the patient computed tomography densities. Validation of the process was ...
The H-D exchange reaction has been measured with the D2-H2O system, for Rhodobacter capsulatus JP91, which lacks the hupSL-encoded hydrogenase, and R. capsulatus BSE16, which lacks the HupUV proteins....Full Text Available
This paper describes a semi-empirical calculation of the air-broadened half-widths and the air pressure-induced frequency shifts for the H_2"1"6O isotopologue. This semi-empirical calculation is based on fits of several recent high-quality measurements and theoretical calculations to the first-order terms in the expansion of the complex Robert-Bonamy (CRB) equations, which yields a second- and first-order polynomial function of the differences in the upper- and lower-state vibrational quantum numbers for the half-width and line shift, respectively. The aim of this work was to obtain a complete set of air-broadened half-widths and air pressure-induced frequency shifts for transitions of H_2"1"6O present in the HITRAN database from microwave to the visible in order to supplement the observed and calculated values. For around 700 sets of rotational quantum numbers (J"'K_a"'K_c"'<-J"''K_a"''K_c"''), semi-empirical ...
Hepatic injury and regeneration of the liver are associated with activation of hepatic stellate cells (HSC). Fibroblast growth factors (FGFs) and their receptors are important regulators of repair in various tissues. HSC express FGFR3IIIc as well as FGFGR4 and different spliced FGFR1IIIc and FGFR2IIIc isoforms which differ in the presence or absence of the acid box and of the first Ig-like domain. Expression of FGF9, known to be capable to activate the HSC FGFR2/3-isoforms, was increased in HSC in liver slice cultures after exposition to carbon tetrachloride, as an acute liver injury model. FGF9 significantly stimulated 3-H thymidine incorporation of hepatocytes, but failed to induce DNA synthesis in HSC despite the fact that FGF9 induced a sustained activation of extracellular signal-related kinases (ERK) 1/2. FGF9 induced an increased phosphorylation of Tyr436 of the fibroblast ...
Flow-induced vibration is an important concern to the designers of heat exchangers subjected to high flows of gases or liquids. Two-phase cross-flow occurs in industrial heat exchangers, such as nuclear steam generators, condensers, and boilers, etc. Under certain flow regimes and fluid velocities, the fluid forces result in tube vibration and damage due to fretting and fatigue. Prediction of these forces requires an understanding of the flow regimes found in heat exchanger tube bundles. Excessive vibrations under normal operating conditions can lead to tube failure. Relatively little information exists on two-phase vibration. This is not surprising as single-phase flow induced vibration; a simpler topic is not yet fully understood. Vibration in two-phase is much more complex because it depends upon two-phase flow regime, i.e. characteristics of two-phase mixture and involves an important consideration, which is the void fraction. The effect of ...
Intercrosses of heterozygous pro-opiomelanocortin (POMC) mice result in homozygous null progeny at lower frequencies than expected. Genotyping offspring at pre-, peri-, and postnatal stages revealed that over half of homozygous null mutants die in the early postnatal stages. To investigate the reasons for this early postnatal lethality, we analyzed in detail different parameters in the initial hours after birth. POMC null mutants born to heterozygous dams presented at birth with corticosterone levels no different from wildtype littermates, were euglycemic, and had normal liver glycogen stores. However, already 30 min after birth corticosterone levels dropped by 80% and were undetectable thereafter, while corticosterone levels in wildtype animals increased during postnatal hours. Circulating adrenaline was almost below detection 1h after birth. Blood glucose levels fell sharply in all genotypes within 30 min after birth; however, wildtype and ...
Since 1984 the thermal-hydraulic code ATHLET has been also applied for the analyses of LOCA and transients in VVER plants. The specific design of these plants especially of the steam generator design requires a specific modelling of the phenomena which may occur under LOCA and transient conditions in these plants. Differences in design compared to the design of western reactors have been briefly listed. Specific phenomena occurring under small leak accidents are shortly described. The consideration of the simulation of the boiler-condenser mode illustrates the modelling requirements for a code which may be applied to the prediction of such a thermal-hydraulic behaviour. Facing the lack of experimental data, the reliability of the simulation has been discussed by means of plausibility studies based on the momentum balance for steam and water. In summary: The VVER reactors differ in design compared to reactors of western ...
Like other Central European countries, Poland faces the twin challenges of improving environmental quality while also fostering sustainable economic development. In this study we examine the costs of different standards for air pollution control, and the cost savings from using incentive-based policy instruments in lieu of more rigid command-and-control policies. The comparisons are based on the results of a simulation model of energy use and air pollution control for the Polish economy over 1990-2015. The model simulates least-cost energy supply decisions under different environmental policy assumptions, the corresponding emissions, and the cost of achieving the specified policy objectives. The model results suggest that incentive-based policies will have efficiency gains over command policies that are at least worthy of consideration and may be quite substantial. The size of the gains in practice depends in part on how much flexibility is ...
Using {gamma}-irradiation-induced reduction in the field of a {sup 60}Co {gamma}-ray source, colloidal silver and gold nanoparticles were prepared from their corresponding metal salts in aqueous solution and compared with those by chemical reduction. The radiation-based method provided silver nanoparticles with higher concentration and narrower size distribution than those obtained by chemical reduction method while there was no significant difference between the two strategies for the preparation of gold nanoparticles. {gamma}-Irradiation of 1.0 x 10{sup -3} M AgNO{sub 3} solution resulted in nearly 100 times more highly concentrated silver colloids than those by citrate reduction. Furthermore, the radiation method could lead to more highly concentrated silver colloids by simply increasing the concentration of AgNO{sub 3} solution up to 2.0 x 10{sup -2} M. The two metal nanoparticles prepared by the two different methods ...
It is of utmost importance to have a computer code in order to analyze how different parameters (like test duration time) affect the unavailability of safety systems of nuclear. In this context, a study was performed in order to evaluate the model employed by the FRANTIC computer code, which performs detailed calculations on the contribution to the system unavailability originated by hardware failures, component tests and repairs, aiming at considering the influence of different test schemes on the system unavailability. It was shown, by means of the results attained that the numerical model used by the FRANTIC code and the analytical model proposed by APOSTOLAKIS and CHU (4) give unavailability values much similar when the component tests are supposed to be perfect. When a test is supposed to be imperfect (that is, when it may induce a test is supposed to be imperfect (that is, when it may induce a ...
Strain-induced crystallization of crosslinked natural rubber (NR) and its synthetic analogue, cis-1,4-polyisoprene (IR), both mixed with various amounts of stearic acid (SA), were investigated by time-resolved X-ray diffraction using a powerful synchrotron radiation source and simultaneous mechanical (tensile) measurement. No acceleration or retardation was observed on NR in spite of the increase of SA amount. Even the SA-free IR crystallized upon stretching, and the overall crystallization behavior of IR shifted to the larger strain ratio with increasing SA content. No difference due to the SA was detected in the deformation of crystal lattice by stress for both NR and IR. These results suggested that the extended network chains are effective for the initiation of crystallization upon stretching, while the role of SA is trivial. These behaviors are much different from their crystallization at low temperature by standing, ...
The thermal properties of five types of radiation-induced wood-polymer composites based on a tropical hardwood, rubberwood (Hevea braziliensis), was studied by oxygen index measurement, differential thermal analysis (DTA) and thermogravimetry (TG). The DTA and TG curves of composites were different from those of rubberwood, which can be attributed to the presence of the incorporated polymers. Of the five composites, the one impregnated with bis(2-chloroethyl)vinyl phosphonate reduced the initial temperature of decomposition, increased the peak temperatures of exothermic reactions, and increased the char yield. Comparison with physical blends of rubberwood and the corresponding polymer provided some evidence of chemical interaction of wood and polymer in some of the composites. (author).
A transient eddy current measurement method is presented to determine the thickness and conductivity of a conductive plate. The conductive plate is induced by an air-cored coil, the magnetic flux density along the axial is measured and the various signals corresponding to plates with different thickness and conductivity are calculated using a 3D transient eddy current simulator. Characteristic features are obtained from the transient response. A similarity-based modeling method is utilized in this study to estimate the thickness and conductivity of the conductive plate. (author)
Biomonitoring requires the application of batteries of different biomarkers, as environmental contaminants induce multiple responses in organisms that are not necessarily correlated. Omic technologies were proposed as an alternative to conventional biomarkers since these techniques quantitatively monitor many biological molecules in a high-throughput manner and thus provide a general appraisal of biological responses altered by exposure to contaminants. As the studies using omic technologies increase, it is becoming clear that any single omic approach may not be sufficient to characterize the complexity of ecosystems. This work aims to provide a preliminary working scheme for the use of combined transcriptomic and proteomic methodologies in environmental biomonitoring. There are difficulti...
The measurement of air pollutants is no more sufficient. It is necessary to assess the risk induced by air pollution, and then to put in place actions to reduce it. The air quality monitoring takes into account different pollutants: nitrogen oxides, carbon monoxide, particulates for the traffic; sulfur dioxide and particulates for use of fuel or coal or chemical transformations in air; ozone and nitrogen dioxide from hydrocarbon and nitrogen oxides emissions; the use of simulation methods allow to calculate the concentrations levels for these pollutants taken as indicators. (N.C.)
The post (neutron) -irradiation high-temperature tensile and creep-rupture properties, deformation and fracture characteristics of austenitic alloys, particularly solution annealed Type 316 steel, are surveyed and correlated with the damage structures developed as a function of irradiation temperature (and dose). The mechanisms proposed to explain the irradiation-induced changes in properties and behaviour are summarised. The factors responsible for the observed differences in the post-irradiation and 'in-reactor' creep-rupture properties and behaviour of an austenitic steel are discussed in terms of the helium gas and stress driven growth of small intergranular bubbles and the atom plating associated with their growth and coalescence. (author).
Predicted by stochastic models and observed experimentally in a number of isomerization reactions, viscosity-induced solvent effects manifest themselves in a significant departure of the reaction rates from the values expected on the basis of transition state theory. These effects are well understood within the framework of stochastic models; however, the predictive power of such models is limited by the fact that their parameters are not readily available. Experiment and molecular dynamics (MD) simulations can provide such information and can serve as the testing grounds for various stochastic models. In real solvents, a change in viscosity is inevitably associated with variation of at least one of the three factors - temperature, pressure, or solvent identity, resulting in different solv...
We theoretically investigate the features of two-photon absorption in a coherently driven four-level atomic system with closed-loop configuration. It is found that two-photon absorption can be completely suppressed just by properly adjusting the relative phase of four coherent low-intensity driving fields and the atomic system becomes transparent against two-photon absorption. From a physical point of view, we explicitly explain these results in terms of quantum interference induced by two different two-photon excitation channels.
Glow discharge plasma nitriding of AISI 304 austenitic stainless steel has been carried out for different processing time under optimum discharge conditions established by spectroscopic analysis. The treated samples were analysed by X-ray diffraction (XRD) to explore the changes induced in the crystallographic structure. The XRD pattern confirmed the formation of an expanded austenite phase (#gamma#_N) owing to incorporation of nitrogen as an interstitial solid solution in the iron lattice. A Vickers microhardness tester was used to evaluate the surface hardness as a function of indentation depth (#mu#m). The results showed clear evidence of surface changes with substantial increase in surface hardness.
"9Be-induced inelastic scattering of "6"2","6"4","6"6Fe and "6"0","6"2","6"4Cr was performed at intermediate beam energies. Excited states in "6"4Cr were measured for the first time. Energies and population patterns of excited states in these neutron-rich Fe and Cr nuclei are compared and interpreted in the framework of large-scale shell-model calculations in different model spaces. Evidence for increased collectivity and for distinct structural changes between the neighboring Fe and Cr isotopic chains near N=40 is presented.
Radiation induced polymerization of methylmethacrylate and copolymerization of styrene-acrylonitrile mixture in mamrase Carpinus betulus was carried out by means of #gamma#-ray, under different moisture levels and additives. Under all conditions the degree of polymerization was as high as 60%. No pronounced differences were observed in the kinetics of the polymerization of MMA either with moisture content of wood nor with kind and amount of additives. At high moisture (80% RH) content the dimensional stability of wood-PMMA was increased four fold as compared with untreated wood. The hardness increased about 100% for a weight conversion of monomer of about 30 to 40%. Hardness of this wood-polymer composite is comparable to that of the best noble woods in the world. (author).
Exact expressions for wave electromagnetic fields during instantaneous braking of two differently charged discs uniformly moving in the opposite directions have been derived. Analysis of their properties has been made. It is shown that electromagnetic wave fields during instantaneous braking of charges have a tearing nature and the Umov-Poynting theorem in the integral form is realized only at a certain value of parameter #alpha# which determines charges rates at the moment of braking. The value of parameter #alpha# is in the ranges from 0.5 to #sq root#3/2. The wave field is formed already in the absence of motion of charged discs. It is a good example confirming the conclusion that in the case of nonstationary electromagnetic fields, performance of reaction force of the wave field can differ fram radiation energy.
? Introduction Old-growth forests on Changbai Mountain are economically and ecologically important but have been fragmented outside Changbai Mountain Biosphere Reserve. The trend of forest landscape degradation on Changbai Mountain threatens forest sustainability and biodiversity conservation in the region. Previous studies have focused mainly on the structure and function of protected forests but have ignored managed forests outside the reserve border. ? Objectives In this paper, deforestation processes are studied for two forestry enterprises, namely Baihe and Lushuihe Forestry Bureaus, with different socioeconomic structure due to their differences in proximity to Changbai Mountain Biosphere Reserve, which attracts hundreds of thousands of tourists each year. Baihe?s income comes from b...
Many coastal areas have served as repositories of different anthropogenic and naturally induced organic material and nutrients. The major sources thereof are riverine inputs which strongly influence the spatial and temporal distribution of benthic communities. In this study, the benthic foraminiferal, meiofaunal, and macrofaunal colonies in front of three rivers in a poorly known, but environmentally valuable, area of the Central Adriatic Sea have been examined concurrently. The physico-chemical parameters of bottom water and sediment characteristics were determined in order to characterize both the sediment?water interface and the benthic environments. Although changes in the biota are neither univocal nor unidirectional, a moderate influence of riverine input on the different communities...
Counting characteristics of X-ray detectors fabricated from indium-doped, gallium-doped, and chlorine-doped CdTe have been investigated. The detectors fabricated from indium-doped and gallium-doped crystals showed radiation-induced polarization, namely, a progressive decrease of count rate with an increase of photon fluence in the high-photon-fluence region, while the detectors fabricated from chlorine-doped crystals did not. Results from current-voltage characteristics of the detectors indicated that the different counting characteristics of these detectors originated from the difference in internal electric fields in each detector.
Rafting of the {gamma}/{gamma}{prime} morphology of nickel-base superalloys is a well-known phenomenon during high-temperature deformation. The initial stages of this type of directional coarsening were modeled two-dimensionally by the method of finite elements (FEs) using an energy-perturbation approach. In addition to the elastic energy density, the effect of the local difference of the hydrostatic stresses in {gamma} and {gamma}{prime} in combination with the different lattice parameters of the two phases was considered in the calculations as a further driving force. From the results of modeling, the deformation-induced internal stresses and strains were determined and used to evaluate the direction-dependent lattice parameters and lattice misfits of the two phases. The results agree well with experimentally determined values.
The modeling methods used to compute the neutron-induced activation of target and near-target materials in the NIF facility are presented. A detailed space and energy description of the neutron environment in the different materials is provided. A new capability has been developed to treat in a general way the activation of debris produced in an operational regime of yield and no-yield experiments. First calculations are addressed to analyze the activity of the debris into the target chamber. The contribution of the different components to activity, interior dose rates, and waste disposal rating (WDR) is determined. The importance of the activation coming from primary irradiation in the target, and from secondary irradiation in debris deposited onto the first wall is assessed. Finally, waste hazards of the activated debris when removed out of the chamber and stored are analyzed. (authors)
Prairie (Microtus ochrogaster) and meadow voles (M. pennsylvanicus) are closely related species that differ in life strategy and social behaviors, and thus provide an excellent comparative model for the study of neuronal and hormonal mechanisms underlying behavior. In the present study using the elevated plus maze (EPM) test, we found that male prairie voles entered the open arms of the EPM more and remained there longer, and showed a higher level of overall locomotor activity than did male meadow voles. In addition, two weeks of social isolation induced an increase in open arm entries in prairie, but not meadow, voles. Prairie voles also had a higher level of circulating corticosterone compared to meadow voles, and the EPM test increased circulating corticosterone in prairie voles. Finally, social isolation coupled with the EPM test influenced Fos-immunoreactive expression in several brain areas, including the medial preoptic area, ...
Ten different alloys of zirconium have been tested with regard to the effect of irradiation on their mechanical properties and their sensitivity to environmentally induced failure. Two different environments were used: iodine vapour and liquid cesium with an addition of 2% cadmium. The neutron dose was 10"2"1n/cm"2 (E>1MeV) and the irradiation temperature was about 300 degrees C. All alloy additions increased the irradiation hardening. Especially notable was the large effect of titanium and tin on irradiation hardening. A limited amount of transmission electron microscopy was carried out in order to find an explanation to the effects. The testing in different environments showed that there is no clear correlation between environmental sensitivity and yield stress. For materials of similar yield stress an alloyed material tends to be more sensitive to environmental cracking than a material which only ...
We report a search for small RNAs (sRNAs) in the low-GC, gram-positive human pathogen Streptococcus pneumoniae. Based on bioinformatic analyses by Livny et al. (J. Livny, A. Brencic, S. Lory, and M. K. Waldor, Nucleic Acids Res. 34:3484-3493, 2006), we tested 40 candidates by Northern blotting and confirmed the expression of nine new and one previously reported (CcnA) sRNAs in strain D39. CcnA is one of five redundant sRNAs reported by Halfmann et al. (A. Halfmann, M. Kovacs, R. Hakenbeck, and R. Bruckner, Mol. Microbiol. 66:110-126, 2007) that are positively controlled by the CiaR response regulator. We characterized 3 of these 14 sRNAs: Spd-sr17 (144 nucleotides [nt]; decreased in stationary phase), Spd-sr37 (80 nt; strongly expressed in all growth phases), and CcnA (93 nt; induced by competence stimulatory peptide). Spd-sr17 and CcnA likely fold into structures containing single-stranded regions between hairpin structures, whereas Spd-sr37 forms a base-paired ...
A dialyzable factor(s) in human serum is known to stimulate gonococcal oxygen consumption. Its effect on other human pathogens was investigated. A 10% serum solution increased peak O2 consumption for Escherichia coli and Staphylococcus aureus to 157% (P less than 0.05) and 199% (P less than 0.02), respectively, of their O2 consumption when suspended in Hanks balanced salt solution, compared with a 356% increase for Neisseria gonorrhoeae with serum. Dialyzed serum lacked stimulatory capacity. Bacteria, serum, and neutrophils are often incubated to evaluate neutrophil bactericidal activity. Samples of 10(8) N. gonorrhoeae, S. aureus, and E. coli turned resazurin colorless (anaerobic conditions, Eh less than -42 mV) after 7.4, 13.3, and 15.1 min, respectively. Because neutrophil formation of reactive oxygen intermediates requires ambient O2, the effect of live bacteria and serum on this process was explored. After 5 min of incubation of 10(8) N. gonorrhoeae or S. ...
This study aims to investigate the difference in the interaction of antimicrobial peptides with two classes of zwitterionic peptides, phosphatidylethanolamines (PE) and phosphatidylcholines (PC). Further experiments were performed on model membranes prepared from specific bacterial lipids, lipopolysaccharides (LPS) isolated from Salmonella minnesota. The structure of the lipid-peptide aqueous dispersions was studied by small-and wide-angle X-ray diffraction during heating and cooling from 5 to 85 C. The lipids and peptides were mixed at lipid-to-peptide ratios 10-10000 (POPE and POPC) or 2-50 (LPS). All experiments were performed at synchrotron soft condensed matter beamline A2 in Hasylab at Desy in Hamburg, Germany. The phases were identified and the lattice parameters were calculated. Alamethicin and melittin interact in similar ways with the lipids. Pure POPC forms only lamellar phases. POPE forms lamellar phases at low temperatures that upon heating transform ...
Reduced systems such as brain slices offer a powerful approach to study the physiology of auditory neurons in great detail. However, when studying auditory nuclei in reduced systems such as brain slices, especially highly active auditory brain stem nuclei, one has to be aware that the unphysiological lack of activity in the reduced system compared to the in-vivo situation has a number of important effects on the neurons under investigation, and thus on the data that are measured. Most importantly, the lack of chronic activity in the slice preparation has important effects on the properties of short-term plasticity of the synapses. The main purpose of this article is to discuss how spontaneous activity in auditory neurons, or the lack thereof, can affect the data measured.
To assess the influence of a live attenuated oral vaccine against porcine post-weaning colibacillosis (PWC) induced by enterotoxigenic Escherichia coli (ETEC) on mucosal lymphoid cell CD45 isoforms expression, experimental group of weaned pigs (n=6) was immunized orally with F4ac+ non-ETEC strain (day 0) and challenged with F4ac+ ETEC strain 7 days latter. Non-immunized ETEC-infected pigs (n=6) served as control. All pigs were killed on post-challenge day 7. The small intestine was excised for isolation of jejunal lamina propria (JLP) and ileal Peyer's patch (IPP) lymphocytes and immunohistochemical studies. The results obtained by immunophenotyping of isolated cells show that the proportion of CD45RA+ and CD45RC+ JLP, but not IPP, cells were higher in the non-ETEC-immunized ETEC-infected pigs versus non-immunized infected. Additionally, while CD45RA+ JLP cells increased only slightly, the expression of CD45RC isoform on the JLP cells was significantly higher ...
We present a collisional-radiative approach of the theoretical analysis of laser-induced breakdown spectroscopy (LIBS) plasmas. This model, which relies on an optimized effective potential atomic structure code, was used to simulate a pure aluminum plasma. The description of aluminum involved a set of 220 atomic levels representative of three different stages of ionization (Al{sup 0}, Al{sup +} and Al{sup ++}). The calculations were carried for stationary plasmas, with input parameters (n{sub e} and T{sub e}) ranging respectively between 10{sup 13-18} cm{sup -3} and 0.3-2 eV. A comparison of our atomic data with some existing databases is made. The code was mainly developed to address the validity of the local thermodynamic equilibrium (LTE) assumption. For usual LIBS plasma parameters, we did not reveal a sizeable discrepancy of the radiative equilibrium of the plasma towards LTE. For cases where LTE was firmly believed to stand, the Boltzmann ...
We present a collisional-radiative approach of the theoretical analysis of laser-induced breakdown spectroscopy (LIBS) plasmas. This model, which relies on an optimized effective potential atomic structure code, was used to simulate a pure aluminum plasma. The description of aluminum involved a set of 220 atomic levels representative of three different stages of ionization (Al0, Al+ and Al++). The calculations were carried for stationary plasmas, with input parameters (ne and Te) ranging respectively between 1013-18 cm-3 and 0.3-2 eV. A comparison of our atomic data with some existing databases is made. The code was mainly developed to address the validity of the local thermodynamic equilibrium (LTE) assumption. For usual LIBS plasma parameters, we did not reveal a sizeable discrepancy of the radiative equilibrium of the plasma towards LTE. For cases where LTE was firmly believed to stand, the Boltzmann plot outputs of this code were used to ...
The blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signal response to neural stimulation is influenced by many factors that are unrelated to the stimulus. These factors are physiological, such as the resting venous cerebral blood volume (CBV(v)) and vessel size, as well as experimental, such as pulse sequence and static magnetic field strength (B(0)). Thus, it is difficult to compare task-induced fMRI signals across subjects, field strengths, and pulse sequences. This problem can be overcome by normalizing the neural activity-induced BOLD fMRI response by a global hypercapnia-induced BOLD signal. To demonstrate the effectiveness of the BOLD normalization approach, gradient-echo BOLD fMRI at 1.5, 4, and 7 T and spin-echo BOLD fMRI at 4 T were performed in human subjects. For neural stimulation, subjects performed sequential finger movements at 2 Hz, while for global stimulation, ...
Lateral and vertical variabilities in the bulk and mechanical properties of silicic volcanic tuff at the potential nuclear waste repository site in Yucca Mountain, NV have been evaluated. Laboratory measurements have been performed on tuff specimens recovered from boreholes located to support the design of the Exploratory Studies Facility/North Ramp. The data include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. Data from eight boreholes aligned in a northwest-southeast direction have been collected under the required quality assurance program. Three boreholes have penetrated the potential repository horizon. The information collected provides for an accurate appraisal of the variability of rock properties in the vicinity of the boreholes. As expected, there is substantial variability in the bulk and mechanical properties of the tuff with depth (lithology). ...
In the discussion of environmental architecture, we are conjoining two disciplines, the subject of architecture and that of ecology. At their best, green buildings are examples of applied ecology, where designers understand the constitution, organization, and structure of ecosystems, and the impacts of architecture are considered from an environmental perspective. By utilizing the concepts, methods, and language of ecology, designers can create architecture that intentionally engages the natural systems of a site. The establishment of assessment criteria implies the definition of building design criteria. If we establish criteria that are based on our best scientific understanding of environmental capacity, we will begin to develop a building stock that is sustainable. To do this we must quantify the link between the resulting environmental impacts and their cause in building production and use. This is not done in traditional building environmental impact assessment methods, which are ...
The previous 58Ni and 60Ni set of resonance parameters (ENDF/B-VII-0, JEFF-3, etc.) was based on the SAMMY analysis of Oak Ridge National Laboratory neutron transmission, scattering cross section and capture cross section measurements by C. M. Perey et al. The present results were obtained by adding to the SAMMY experimental data base the capture cross sections measured recently at the Oak Ridge Linear Electron Accelerator by Guber et al. and the Geel Electron Linear Accelerator very high-resolution neutron transmission measurements performed by Brusegan et al. A complete resonance parameter covariance matrix (RPCM) was obtained from the SAMMY analysis of the experimental database. The data sets were made consistent, when needed, by adjusting the neutron energy scales, the normalization coefficients, and the background corrections. The RPCM allows the calculation of the cross section uncertainties due mainly to statistical errors in the experimental data. The systematic uncertainties ...
The previous {sup 58}Ni and {sup 60}Ni set of resonance parameters (Endf/B7.O, Jeff-3, etc.) was based on the SAMMY analysis of Oak Ridge National Laboratory neutron transmission, scattering cross section and capture cross section measurements by C.M. Perey et al. The present results were obtained by adding to the SAMMY experimental database the capture cross sections measured recently at the Oak Ridge Linear Electron Accelerator by Guber et al. and the Geel Electron Linear Accelerator and very high-resolution neutron transmission measurements performed by Brusegan et al. A complete resonance parameter covariance matrix (RPCM) was obtained from the SAMMY analysis of the experimental database. The data sets were made consistent, when needed, by adjusting the neutron energy scales, the normalization coefficients, and the background corrections. The RPCM allows the calculation of the cross section uncertainties due mainly to statistical errors in the experimental data. The systematic ...
Quality Assurance (QA) has not been taken very seriously in developing countries despite their having significant nuclear power programmes. This may affect plant reliability and demands that urgent and serious attention be given to the development and implementation of Quality Assurance programmes according to local conditions. Confusion has been created by the differences in definitions and interpretations of terminologies of Quality Assurance and Control. Problems have been aggravated by the lack of clearly defined responsibilities and accountabilities during the projects execution phases of site selection, data collection, design, equipment fabrication and construction, etc. Therefore, reliability of nuclear power plants in developing countries is relatively low. But whenever some programme of QA has been implemented it has helped to improve the plant performance. This is highlighted in this paper by the practical examples for the experience ...
Four trypsin inhibitor homologs, the first known from Dendroaspis angusticeps venom, were characterized using a combination of gel filtration, cation exchange, reverse-phase liquid chromatography, Edman degradation and mass spectrometry. The four toxins comprise two 57 residue and two 59 residue isoforms. The long toxins possess a Lys-Gln N-terminal extension lacked by the short toxins. The only other structural difference is an Arg/His replacement at position 55. The long Arg55 variant is identical to trypsin inhibitor E from the venom of Dendroaspis polylepis. The name epsilon-dendrotoxin is suggested so as to follow the nomenclature of Benishin, C.G., Sorensen, R.G., Brown, W.E., Krueger, B.K., Blaustein, M.P., 1988. Four polypeptide components of green mamba venom selectively block certain potassium channels in rat brain synaptosomes. Mol. Pharmacol. 34, 152-159. Among snake venom protease inhibitors, the epsilon-dendrotoxins are ...
Pancreatic amyloid deposits of amylin are a hallmark of Type II diabetes and considerable evidence indicates that amylin oligomers are cytotoxic to beta-cells. Many efforts are presently spent to find out naturally occurring molecules, or to design synthetic ones, able to hinder amylin aggregation or to protect cells against aggregate cytotoxicity. In this context, a protective effect of some polyphenols against amyloid cytotoxicity was reported. Actually dietary polyphenols are endowed with multiple health benefits, and extra virgin olive oil is attracting increasing interest as a source of these substances. Here, we investigated the effects on amylin aggregation and cytotoxicity of the secoiridoid oleuropein aglycon, the main phenolic component of extra virgin olive oil. We found that oleuropein, when present during the aggregation of amylin, consistently prevented its cytotoxicity to RIN-5F pancreatic beta-cells, as determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl ...
Probabilistic risk analysis has historically been developed for situations in which measured data about the overall reliability of a system are limited and expert knowledge is the best source of information available. There continue to be a number of important problem areas characterized by a lack of hard data. However, in other important problem areas the emergence of information technology has transformed the situation from one characterized by little data to one characterized by data overabundance. Natural disaster risk assessments for events impacting large-scale, critical infrastructure systems such as electric power distribution systems, transportation systems, water supply systems, and natural gas supply systems are important examples of problems characterized by data overabundance. There are often substantial amounts of information collected and archived about the behavior of these systems over time. Yet it can be difficult to effectively utilize these ...
As part of The International Northern Sea Route Programme (INSROP), Subprogram III, Trade and Commercial Shipping, a study has been made concerning seaborne export of liquefied petroleum gas (LPG) from the Northern Russia, especially the West Siberian fields in Tyumen. The main purpose of the total project III.0703, part 2 and this study is to evaluate the economic viability of seaborne export from this area to the European region, mainly with the use of a special ice-strengthened LPG vessel, constructed and designed for such seaborne operations. This study concentrates on both seaborne LPG transportation, the demand and supply for seaborne LPG in the world and marine transportation of LPG from the West Siberian fields. Another purpose is to see which regions are potential exporters, importers and buyers of seaborne export of LPG from Tyumen. Currently large quantities of liquefied gas are flared off at the West Siberian fields due to insufficient infrastructure, ...
Natural cooling conditions of the nuclear fuel in the channel type reactor after its shut down are commonly determined with relatively high uncertainty. This is not only to he lack of adequate measurements of thermal parameters i.e. the residual power generation, the coolant flow and temperatures, but also due to indeterminate model of convection mechanism. The numerical simulation of natural convection in multitube fuel assembly in the fuel channel leads to various convection modes including evidently chaotic behaviour. To determine the real cooling conditions in the MARIA research reactor a series of experiments has been performed with fuel assembly equipped with a set of thermocouples. After some forced cooling period (the shortest was half an hour after the reactor shut down) the reactor was left with the only natural convection. Two completely different cooling modes have been observed. The MARIA core consists of series of individual fuel ...
How should lightweight electric-powered vehicles be promoted, after the large-scale fleet test being conducted at Mendrisio (southern Switzerland) is completed in 2001, and are there reasons to put question marks behind the current approach? The demand for electric vehicles, and particularly the one in the automobile category, has remained at a persistently low level. As it proved, any appreciable improvement of this situation is almost impossible, even with substantial financial incentives. However, the unsatisfactory sales figures have little to do with the nature of the fleet test itself or with the specific conditions at Mendrisio. The problem is rather of structural nature. For (battery-operated) electric cars the main problem at present is the lack of an expanding market which could become self-supporting with only a few additional incentives. Various strategies have been evaluated. Two alternatives were considered in particular: a strategy to promote ...
We have studied the dissolution behavior of uraninite, becquerelite, schoepite and uranophane. The information obtained under a variety of experimental conditions has been combined with extensive solid phase characterizations, performed in both leached and unleached samples. The overall objective is to construct a thermodynamic and kinetic model for the long-term oxidation alteration of UO{sub 2}(s), as an analogy of the spent nuclear fuel matrix. We have determined the solubility product for becquerelite (logK{sub s0} 32.7{+-}1.3) and uranophane (logK{sub s0} = 7.8{+-}0.8). In some experiments, the reaction progress has shown initial dissolution of uranophane followed by precipitation of a secondary solid phase, characterized as soddyite. The solubility production for this phase has been determined (logK{sub s0} = 3.0{+-}2.9). We have studied the kinetics of dissolution of uraninite, uranophane and schoepite under oxidizing conditions in synthetic granitic groundwater. BET ...
The advent of light metal alloys and advanced materials (polymer, composites, etc.) have brought the possibility of achieving important energy reductions into the full life cycle of these materials, especially in transportation applications. 1 These materials have gained acceptance in the aerospace industry but use of light metal alloys needs to gain wider acceptance in other commercial transportation areas. Among the main reasons for the relatively low use of these materials are the lack of manufacturability, insufficient mechanical properties, and increased material costs due to processing inefficiencies. Considering the enormous potential energy savings associated with the use of light metal alloys and advanced materials in transportation, there is a need to identify R&D opportunities in the fields of materials fabrication and forming aimed at developing materials with high specific mechanical properties combined with energy efficient processes and good ...
The advancement of bioprocess monitoring will play a crucial role to meet the future requirements of bioprocess technology. Major issues are the acceleration of process development to reduce the time to the market and to ensure optimal exploitation of the cell factory and further to cope with the requirements of the Process Analytical Technology initiative. Due to the enormous complexity of cellular systems and lack of appropriate sensor systems microbial production processes are still poorly understood. This holds generally true for the most microbial production processes, in particular for the recombinant protein production due to strong interaction between recombinant gene expression and host cell metabolism. Therefore, it is necessary to scrutinise the role of the different cellular compartments in the biosynthesis process in order to develop comprehensive process monitoring concepts by involving the most significant process variables and ...
The effect of electron beam welding parameters on fusion zone (FZ) microstructure and porosity in a Ti-6.8 Al-3.42 Mo-1.9 Zr-0.21 Si alloy (Russian designation VT 9) has been investigated. It has been observed that the FZ grain width increased continuously with increase in heat input when the base metal was in the #beta# heat-treated condition, while in the #alpha# + #beta# heat-treated base metal welds, the FZ grain width increased only after a threshold energy input. The difference is attributed to both the weld thermal cycle and the pinning effect of equiaxed primary alpha on grain growth in the heat-affected zone (HAZ) of #alpha# + #beta# heat-treated base metal. Postweld heat treatment (PWHT) in the subtransus and supertransus regions did not alter the columnar grain morphology in the FZ, possibly due to the lack of enough driving force for the formation of new grains by the breaking up of the columnar grains and grain boundary movement ...
Alloyed steels containing retained austenite after martensitic hardening are widely applied in technical practice. Although many practical investigations have been made into the mechanical behaviour of composite microstructures with retained austenite, there is still a lack of knowledge concerning their fatigue and crack propagation behaviour. For this reason, the author investigated the effects of retained austenite concentration and stability on the transformation and deformation behaviour of hardened states of the steels X210Cr12 and 100Cr6. For this purpose, monotone tensile tests, cyclic tensile pressure tests, and supplementary crack propagation experiments were carried out. The concentrations of retained austenite were varied between 10 and 100% by volume by means of different heat treatments. [Deutsch] Legierte Staehle, die nach martensitischer Haertung noch Restaustenit enthalten, finden in der technischen Praxis verbreitete Anwendung. ...
According to the calculations, intensity of the KL_1L_2("3P_0) Auger transition should drastically increase with increasing atomic number Z due to the relativistic effects. However, this behavior was experimentally proved only for very few elements. A lack of enough precise experimental data in the atomic number region Z<45 does not enable one to distinguish between relativistic and non-relativistic approaches in this region. Thus for Z=38 the KL_1L_2("3P_0/"1P_1) intensity ratio was determined with relative uncertainty of 63 % in the only measurement with external excitation. Here we present results of our investigation of the KLL Auger electron spectrum of "8"8Sr generated in the EC decay of "8"8Y (T_1_/_2= 106.6 d). Electron spectra were measured with the 11 eV instrumental resolution using a combined electrostatic spectrometer. The present value of the KL_2L_3("1D_2) absolute transition energy in Sr is higher by 7.4 eV (i.e. more than 3#sigma#) then that ...
An extensive study of the effects of correlations on both charged and neutral current weak interaction rates in dense matter is performed. Both strong and electromagnetic correlations are considered. The propagation of particle-hole interactions in the medium plays an important role in determining the neutrino mean free paths. The effects due to Pauli blocking and density, spin, and isospin correlations in the medium significantly reduce the neutrino cross sections. As a result of the lack of experimental information at high density, these correlations are necessarily model dependent. For example, spin correlations in nonrelativistic models are found to lead to larger suppressions of neutrino cross sections compared to those of relativistic models. This is due to the tendency of the nonrelativistic models to develop spin instabilities. Notwithstanding the above caveats, and the differences between nonrelativistic and relativistic approaches ...
Female rats were given tritiated drinking water (3 microCi/ml) from 30 days before mating up to and throughout pregnancy. At this low dose, the course and the outcome of pregnancy were normal. The differences between newborn body and cerebral weights of the treated rats and those of control animals were on the borderline of significance. In contrast, cerebral DNA and cerebral protein were highly significantly lower. In 30-35% of the treated population the DNA and protein values were more than 2 standard deviations (SD) below the mean values for the control population. Thus the number of the progeny of the mothers exposed to tritiated water that were considered to have outstandingly low levels of DNA and protein was 14-17 times greater than in the control group. The irradiated population also had 3-5% of severely affected individuals with cerebral DNA and protein values more than 2 SD below the mean of the experimental population. However, even in this irradiated ...
Background. In multiple myeloma 5 different infiltration patterns can be differentiated: 1. Normal appearance of bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. 'salt-and pepper' pattern with inhomogeneous bone marrow with interposition of fat islands. Methods. For the fast and total acquisition of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique is superior. The focal involvement is clearly demonstrated as areas of high signal intensity on e.g. STIR images. Diffuse involvement can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. MRI is superior to X-ray in focal and diffuse involvement. With ultrafast sequences a 'screening' of the whole red bone marrow as for myeloma infiltration is possible. Prognosis. In prognosis studies diffuse infiltration is inferior to focal ...
A crucial step in human breast cancer progression is the acquisition of invasiveness. There is a distinct lack of human cell culture models to study the transition from pre-invasive to invasive phenotype as it may occur 'spontaneously' in vivo. To delineate molecular alterations important for this transition, we isolated human breast epithelial cell lines that showed partial loss of tissue polarity in three-dimensional reconstituted-basement membrane cultures. These cells remained non-invasive; however, unlike their non-malignant counterparts, they exhibited a high propensity to acquire invasiveness through basement membrane in culture. The genomic aberrations and gene expression profiles of the cells in this model showed a high degree of similarity to primary breast tumor profiles. The xenograft tumors formed by the cell lines in three different microenvironments in nude mice displayed metaplastic phenotypes, including ...
A formalism for the dynamical treatment of the molecular orbitals of valence nucleons in nucleus-nucleus collisions is developed with the use of the coupled-reaction-channel (CRC) method. The Coriolis coupling effects as well as the finite mass effects of the nucleon are taken into account in this model, of rotating molecular orbitals, RMO. First, the validity of the concept is examined from the viewpoint of the multi-step processes in a standard CRC calculation for systems containing two identical [core] nuclei. The calculations show strong CRC effects particularly in the case where the mixing of different l-parity orbitals - called hybridization in atomic physics - occurs. Then, the RMO representation for active nucleons is applied to the same systems and compared to the CRC results. Its validity is investigated with respect to the radial motion (adiabaticity) and the rotation of the molecular axis (radial and rotational coupling). Characteristic molecular ...
Thoracic aortic aneurysms (TAAs) are potentially devastating, and due to their asymptomatic behavior, pose a serious health risk characterized by the lack of medical treatment options and high...Full Text Available
BackgroundMany studies have evaluated the accuracy of dipstick tests as rapid detectors of bacteriuria and urinary tract infections (UTI). The lack of an adequate explanation for...Full Text Available
The difficulties created by the lack of generally accepted views on classification, diagnostic criteria and natural history of the cutaneous lymphomata are discussed. Only the lymphomata which remain...Full Text Available
OBJECTIVE--To assess the accuracy of the ten questions screen as a measure of childhood disability for epidemiologic studies in populations lacking resources for professional assessment of children's...Full Text Available
Although genetic engineering techniques for baker's yeast might improve the yeast's fermentation characteristics, the lack of scientific data on the survival of such strains in natural environments...Full Text Available
Patients with Alport syndrome progressively lose renal function as a result of defective type IV collagen in their glomerular basement membrane. In mice lacking the α3 chain of type IV collagen...Full Text Available
The objectives of this study were to select and initially characterize mutants of soybean (Glycine max L. Merr. cv Williams) with decreased ability to reduce nitrate. Selection involved...Full Text Available
BackgroundThere is a lack of studies considering social disparity in oral health emanating from adolescents in low-income countries. This study aimed to assess socio-demographic...Full Text Available
Treatment of functional bowel disorders of irritable bowel-type (IBS) in children remains a difficult task because of a lack of drugs with low adverse event profile. We here report the results of a...Full Text Available
During a study of the health status of children in rural Nigerian communities a gross lack of fit was observed between the sample and the growth attainment standards derived from local longitudinal...Full Text Available
Successful implementation of bone marrow transplantation for hematopoietic reconstitution is limited by the lack of suitably HLA-matched donors and by the occurrence of graft-versus-host disease that...Full Text Available
Mutant strains of the yeast Saccharomyces cerevisiae which lack functional Cu,Zn superoxide dismutase (SOD-1) do not grow aerobically unless supplemented with methionine. The molecular basis of this...Full Text Available
BackgroundThe lack of adequate randomized clinical trials (RCT) has hindered identification of new therapies that are safe and effective for patients with primary focal segmental...Full Text Available
Arriving at a firm diagnosis of neurosarcoidosis continues to pose serious problems, particularly when evidence of granulomatous disease outside the nervous system is lacking. The commonest mode of...Full Text Available
Various hypotheses have been proposed to explain the molecule processes of sarcomere assembly, partially due to the lack of systematic genetic studies of sarcomeric genes in an in vivo...Full Text Available
Four infants with obstructive hydrocephalus caused by space occupying third ventricle and mesencephalic cysts are reported. Despite immediate shunt insertion in all patients, there was either lack of...Full Text Available
A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.
Major breakthroughs have recently been reported that can help overcome two inherent drawbacks of NMR: the lack of sensitivity and the limited memory of longitudinal magnetization. Dynamic nuclear polarization...Full Text Available
This study examines some radiation accidents occurred in the past. This information has been systematically assessed to get global lessons. The experience feedback shows that the most of accidents happened in certain conditions. These conditions can be distributed in four categories: 1- perception and vigilance in occupation: accidental exposure happened by lack of vigilance in details and lack of vigilance and perception; 2- procedures: accidental exposure happened following a lack of procedures or control that were not enough complete, not enough documented or not completely implemented; 3- training and understanding: accidental exposures happened because the personnel was not enough qualified and educated, did not get the general training nor the the necessary specialized training; 4- liabilities: accidental exposures happened following lacks and ambiguity in the definition of functions of the ...
BackgroundThe analgesic effect of perioperative low doses intravenous lidocaine has been demonstrated after abdominal surgery. This study aimed to evaluate whether...Full Text Available
Dysregulation of the alternative pathway of complement activation, caused by mutations or polymorphisms in the genes encoding factor H, membrane co-factor protein, factor I or factor B, is associated...Full Text Available
BackgroundHigh serum uric acid concentration (hyperuricemia) has been studied for its relationship with multiple adverse health outcomes, such as metabolic syndrome. Intervention...Full Text Available
PurposeTo assess the prevalence and the dosimetric and clinical predictors of mandibular osteoradionecrosis (ORN) in patients with head and neck (HN) cancer who underwent...Full Text Available
BackgroundApolipoprotein E (ApoE), a cholesterol carrier associated with atherosclerosis, is a major risk factor for Alzheimer's disease (AD). The low-density lipoprotein receptor...Full Text Available
The water permeability of tissues was investigated by measuring the efflux of 3HHO from previously loaded (in darkness) etiolated bean buds (Phaseolus vulgaris L. var. Red...Full Text Available
Disruption of circadian rhythms may be involved in the pathophysiology of psychiatric disorders, including drug addiction. Recently, we detected the significant association between prokineticin 2 receptor...Full Text Available
The virtual lack of well-characterized metastatic pancreatic cancer tissues for study has limited systematic studies of the metastatic process of this deadly disease. To address this important...Full Text Available
BACKGROUND: Although the importance of lymphatic function is well recognized, the lack of real-time imaging modalities limits our understanding of its role in many diseases. In a phase...Full Text Available
Natural accumulations of skeletal material (death assemblages) have the potential to provide historical data on species diversity and population structure for regions lacking decades of wildlife monitoring,...Full Text Available
Purpose of reviewSevere congenital neutropenia (SCN) is a primary immunodeficiency in which lack of neutrophils causes inadequate innate immune host response to bacterial...Full Text Available
BackgroundSpecies with heteromorphic sex chromosomes face the challenge of large-scale imbalance in gene dose. Microarray-based studies in several independent male heterogametic...Full Text Available
DNA double-strand breaks (DSBs) are generally accepted to be the most biologically significant lesion by which ionizing radiation causes cancer and hereditary disease. However, no information on the...Full Text Available
Mice lacking acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), an enzyme that catalyzes the terminal step in triacylglycerol synthesis, have enhanced insulin sensitivity and are protected from...Full Text Available
Current methods of detecting confidentiality breaches in electronic medical record systems are inadequate, partially due to the lack of necessary information at the point of audit trail analysis. In...Full Text Available
A micro-mechanistic understanding of bone fracture thatencompasses how cracks interact with the underlying microstructure anddefines their local failure mode is lacking, despite extensive research nthe response of bone to a variety of factors like aging, loading, and/ordisease.
Carney-Stratakis syndrome, an inherited condition predisposing affected individuals to gastrointestinal stromal tumor (GIST) and paraganglioma, is caused by germline mutations in succinate dehydrogenase...Full Text Available
Cytokinins are hormones that regulate cell division and development. As a result of a lack of specific mutants and biochemical tools, it has not been possible to study the consequences of cytokinin...Full Text Available
IntroductionAutologous chondrocyte transplantation (ACT) is a routine technique to regenerate focal cartilage lesions. However, patients with osteoarthritis (OA) are lacking an appropriate...Full Text Available
Two nitrate reductase (NR) mutants were selected for low nitrate reductase (LNR) activity by in vivo NR microassays of M2 seedlings derived from nitrosomethylurea-mutagenized...Full Text Available
Scoping studies have been used across a range of disciplines for a wide variety of purposes. However, their value is increasingly limited by a lack of definition and clarity of purpose. The UK's Service...Full Text Available
Lack of understanding about workflow can impair health IT system adoption. Observational techniques can provide valuable information about clinical workflow. A pilot study using direct observation was...Full Text Available
BackgroundMany commercial banana varieties lack sources of resistance to pests and diseases, as a consequence of sterility and narrow genetic background. Fertile wild relatives,...Full Text Available
MRI plays an increasingly important role for assessment of patients with chronic liver disease. MRI has numerous advantages, including lack of ionizing radiation and the possibility of performing...Full Text Available
BackgroundClassification systems may be useful to direct more aggressive treatment to cancer patients with a relatively poor prognosis. The definition of 'poor prognosis' often lacks...Full Text Available
The identification of MHC class II restricted peptide epitopes is an important goal in immunological research. A number of computational tools have been developed for this purpose, but there is a lack...Full Text Available
Ultraviolet (UV) photoirradiation of Ag(I) compounds in the presence of an aqueous Triton X-100 solution has been exploited for the first time to prepare reproducible yellow silver hydrosol. The evolution of nanosized silver particles has been examined critically under the influence of different anions/ligands. Hence, time dependent evolution of silver hydrosol from different silver compounds in micelle via photochemical reduction is observed. Anions/ligands of precursor salts have been found to show profound influence (due to electron scavenging property, solubility, stability etc.) on the evolution route and efficiency of photochemical reduction of Ag(I) to Ag(O) in micelle and thereby classification of silver compounds becomes possible. Kinetic results reveal that the formation of silver particles proceeds via autocatalytic growth mechanism. The observed variation in rate constant values for the evolution of nanoparticles from ...
Burnup calculations with SARC system were carried out to analyse the effects of plutonium build-up on criticality of MTR type research reactor PARR-1 using several WIMSD libraries based on evaluated nuclear data files ENDFB-VI.8, JEF-2.2, JEFF-3.1 and JENDL-3.2. For equilibrium core of the reactor, it was found that a net reactivity of more than 3.5 mk is induced due to build-up of plutonium isotopes during depletion. The plutonium credit amounts to 3% of the length of equilibrium cycle. From the analysis of actinide production in the core during burnup, it was observed that in most of the cases, the amounts of actinides obtained using various cross section libraries agree fairly with each other, however, significant differences were observed for {sup 238}Pu, {sup 241}Pu, {sup 242m}Am, {sup 243}Am, {sup 242}Cm and {sup 244}Cm for some libraries. The actinide chain analysis was conducted to investigate the reasons for the observed ...
The goal of the present study is to elucidate the effect of lipid domain formation on activities of Naja naja atra and Bungarus multicinctus phospholipase A(2) (PLA(2)) enzymes. Sphingomyelin inhibited enzymatic activity and membrane-damaging activity of PLA(2) against egg yolk phosphatidylcholine (EYPC), while cholesterol and cholesterol sulfate abrogated the inhibitory effect of sphingomyelin. The ability of cholesterol and cholesterol sulfate to abolish the inhibitory effect of sphingomyelin was closely related to their capacity to induce domain formation in EYPC/sphingomyelin vesicles. Laurdan fluorescence measurement revealed that membrane packing of EYPC/sphingomyelin vesicles was differently affected by cholesterol and cholesterol sulfate. Unlike cholesterol, cholesterol sulfate was unable to promote domain formation in dipalmitoylphosphatidylcholine (DPPC) vesicles. Cholesterol increased but cholesterol sulfate reduced PLA(2) activity ...
The product of the human GRO gene is a cytokine with inflammatory and growth-regulatory properties; GRO is also called MGSA for melanoma growth-stimulatory activity. The authors have identified two additional genes, GRO#beta# and GRO#gamma#, that share 90% and 86% identity at the deduced amino acid level with the original GRO#alpha# isolate. One amino acid substitution of proline in GRO#alpha# by leucine in GRO#beta# and GRO#gamma# leads to a large predicted change in protein conformation. Significant differences also exist in the 3' untranslated region, including different numbers of ATTTA repeats associated with mRNA instability. A 122-base-pair region in the 3' region is conserved among the three GRO genes, and a part of it is also conserved in the Chinese hamster genome, suggesting a role in regulation. DNA hybridization with oligonucleotide probes and partial sequence analysis of the genomic clones confirm that the three forms are derived ...
Thermoluminescence (TL) dosimetry was used to measure dose effects on the raw stock material of borosilicate container glass from different geographical locations. Effects were studied at times up to 60 days post-irradiation at doses from 0.15 to 20 Gy. The minimum detectable dose using this technique was estimated to be 0.15 Gy which is roughly equivalent to a 24 hr irradiation 1 cm from a 50 ng source of 60Co. Two peaks were identified in the TL glow curve, a relatively unstable peak around 125 C and a more stable peak around 225 C. Differences in TL glow curve shape and intensity were also observed for the glasses from different geographical origins. We investigate radiation induced defects in glass to further develop the technique of intrinsic dosimetry - the measurement of the total absorbed dose received by the walls of a container holding radioactive material. Intrinsic dosimetry is intended to ...
Pregnant rats in 11d and 16d of their pregnancy were given one-off whole body exposure by "1"3"7Cs #gamma# rays to 0.2, 0.4, 0.9 and 2.0 Gy, respectively. Changes were observed in conditioned drinking response and cerebrum hippocampi cone cell number of the baby rats exposed to the #gamma# rays in different periods of their embryo development. As a result, that pregnant rats exposed to "1"3"7Cs #gamma# rays in different pregnant periods may induce significant decrease in cerebrum hippocampi cone cell number and achieving rate of conditioned drinking response of the babies. The dose-response relationship can be described by Y=a-b log_1_0D. The achieving rate of conditioned drinking response were significantly correlated to cerebrum hippocampi cone cell number in the babies, and the achieving rate of conditioned drinking response of the babies exposed at pregnant 11d was lower than others exposed at pregnant 16d
In this paper, we report the systematic investigation on the melt characteristics of silicon during laser thermal processing (LTP) of amorphous silicon (a-Si) gates on ultrathin gate oxides. LTP is used to reduce the gate depletion effect in advanced semiconductor devices. The influence of implantation-induced damage and chemical inhomogeneities on the melt behavior of ion-implanted a-Si is studied using in situ time-resolved reflectance (TRR) measurements and ex situ secondary ion mass spectrometry. The results from TRR measurements indicate the presence of a buried melt for a-Si implanted with B"+ at a subamorphizing dose. In contrast, such a melt behavior is not observed during LTP of undoped a-Si and a-Si implanted with As"+ at an amorphizing dose. We attribute the marked difference in the melt characteristics to the competitive effects between compositional inhomogeneities and the extent of amorphization in the a-Si layer. It should be ...
The electronic band structure, transport properties, and lattice dynamics in AuX_2 (X = Al, Ga and In) under high pressure have been extensively studied with full potential linearized augmented plane wave and pseudopotential plane wave methods. The theoretical results for the electronic band structure and Fermi surface reveal pressure-induced electronic topological transitions (ETTs) in AuGa_2 and AuIn_2, while they are absent in AuAl_2, in excellent agreement with the experimental observations. Moreover, calculations of the transport properties at different pressures reveal subtle changes in the band structure close to the Fermi surface of the three intermetallic compounds. It is clear that the anomalies in transport properties are due to ETTs. Interestingly, a pressure-induced soft transverse acoustic (TA) phonon mode is identified only in AuGa_2. The TA phonon instability at the Brillouin zone boundary L point might be ...
Using standard brass alloy samples, an approach to reduce the laser-induced breakdown spectroscopy measurement uncertainty was tested and proved. Two important parameters for plasma characterization, the plasma temperature and the electron density, were applied to minimize the signal uncertainties due to uncontrollable experimental parameter variations. Results show that for the pulse-to-pulse analysis, the signal fluctuations can be significantly reduced by utilizing the plasma characteristic information. The major source for the single pulse fluctuations is the redistribution of the characteristic line at different temperatures according to the Boltzmann distribution under LTE. The change of the degree of ionization also contributes to the signal fluctuations. For the multi-pulse analysis, due to the nonlinear relationship between the plasma temperature and the line intensity, it is not applicable to utilize the Boltzmann distribution to ...
In this paper the structural and functional changes of gamma irradiated bovine hemoglobin are presented. Aqueous solutions/1%/of HbO_2 were irradiated in air with doses ranging from 1 to 4 Mrad. Isoelectric focusing indicated change of the charge of irradiated hemoglobin. The isoelectric point of hemoglobin was displaced towards more acid values with increasing doses, up from 1 Mrad. Fingerprint analysis and peptide column chromatography of irradiated hemoglobin demonstrated disturbances increasing with the dose. These changes were confirmed by amino acid analysis which showed that Cys, Met, Trp, His, Pro and Tyr residues were destroyed or modified following irradiation. At doses exceeding 1 Mrad the irradiated solutions of hemoglobin showed a decrease of heme-heme interaction and an increase of affinity for oxygen. Differences observed in oxygen-dissociation curves seem to be correlated with the radiation induced destruction of amino acid ...
We studied regional myocardial perfusion by scintigraphic computer-assisted analysis of initial distribution, washout rates, and residual activity of "1"3"3Xe injected into the left coronary artery of four patients with normal arteriograms and 14 patients with coronary stenosis. At rest, residual activity in poststenotic regions was always greater than in control regions, but initial washout rates were not slower. During angina, following xenon injections, the amount of indicator distributed to the poststenotic regions was markedly reduced; the increase of the initial washout rates was smaller than in control regions relative to rest, and residual activity was higher. Initial washout rates did not differ as much as from those of normal myocardium because in severe ischemia too little indicator is deposited initially in these regions to produce a change of any magnitude. Indeed, when angina was induced immediately after the xenon injection, ...
Tensile specimens 60 ..mu..m thick of Ni-8 at. % Si have been bombarded at 475/sup 0/C to doses of 0.1 to 0.3 dpa with either 7 MeV proton or 28 MeV alpha particle beams. Deliberate embrittlement by high temperature (700/sup 0/C) preimplantation of helium was required to produce intergranular fracture. Depth profile sputtering and analysis in a Scanning Auger Microprobe was then used to study radiation-induced segregation of silicon both at the external surfaces and at internal interfaces. The external surfaces exhibited a strongly silicon-enriched zone for the first 10 to 20 nm followed by a broad (approx.200 nm), shallow silicon-depleted region. Segregation of silicon to grain boundaries varied from interface to interface and possibly from region to region on a given interface. In general, however, depth profiles of silicon content with distance from internal boundaries showed no noticeable depletion zone and a more gradual fall-off compared to the profiles from ...
This report examines the use of probabilistic methods in dealing with the problem of potential earthquake-induced liquefaction of foundation soils at an example dam site located in the central United States, near the New Madrid earthquake zone. The example dam is assumed to be a 1-mile long rolled-filled embankment founded on a 100-ft deep deposit of interbedded alluvial gravels, sands, silts, and clays. The study is seen as an opportunity to examine probabilistic concepts and procedures in the framework of an example engineering project. In this context, the main practical value of a probabilistic approach is that it permits more informed decision making about further data acquisition, additional engineering analysis, and if necessary, remedial action. The specific aim of the study is to show how probabilistic procedures complement and help to reinterpret the results of deterministic (earthquake-induced) liquefaction analysis. The procedures ...
We present changes in the p53 gene in a group of 70 thyroid tumours and 40 blood samples obtained from children from Belarus. Three thyroid tumours show a polymorphism in exon 6 (codon 213) and 5 tumours show a polymorphism in intron 6, 37 bp upstream to the 5'-end of exon 7. Only one patient has a mutation in exon 7 (codon 258) resulting in an amino acid substitution in the protein p53. The distribution of polymorphisms in the 40 blood samples was as follows: three patients had a polymorphism in exon 6 and two persons had a polymorphism in intron 6. One polymorphism in intron 6 was also found in the group of 30 healthy children from Belarus. The fact that the differences in the sequence in p53 found in the tumours was also seen in the blood of these patients demonstrates that they are polymorphisms not induced by radiation exposure. It is difficult to conclude, if the polymorphisms found by us could be associated with the predisposition to ...
Aims: Serotonin (5-hydroxytryptamine 3; 5-HT3) receptors are involved in chemotherapy-induced nausea and vomiting (CINV), and 5-HT3 antagonists are part of the `gold standard' antiemetic treatment during chemotherapy. We investigated the correlation of common variants in 5-HT3 receptor subunit genes with the occurrence of CINV. Materials & methods: A total of 110 previously characterized chemotherapy-naive women with primary breast cancer treated with anthracycline-containing chemotherapy served as a study group for mutational analysis by direct sequencing. Eight common SNPs in the 5-HT3 receptor genes, HTR3A, HTR3B, HTR3D and HTR3E, were selected for association analysis. Results: A nonsynonymous variant in HTR3D, p.G36A (rs6443930), was found to be over-represented in nonresponders, assu...
We have investigated the structures formed by oligonucleotides composed of two or four repeats of the telomeric sequences from Oxytricha and Tetrahymena. The Oxytricha four-repeat molecule (d(T4G4)4 = Oxy-4) forms structures with increased electrophoretic mobility in nondenaturing gels containing Na+, K+, or Cs+, but not in gels containing Li+ or no added salt. Formation of the folded structure results in protection of a set of dG's from methylation by dimethyl sulfate. Efficient UV-induced cross-links are observed in Oxy-4 and the related sequence from Tetrahymena (d(T2G4)4 = Tet-4), and join thymidine residues in different repeats. Models proposed to account for these data involve G-quartets, hydrogen-bonded structures formed from four guanosine residues in a square-planar array. We propose that the G-quartet structure must be dealt with in vivo by the telomere replication machinery.
Microwaves were used to induce self-propagating high temperature synthesis (SHS) in the reaction 3TiO{sub 2}+3C+(4+x)Al {yields} 3TiC+2Al{sub 2}O{sub 3}+xAl. The SHS process was studied for x = 0 and 4, using slow and fast heating rates and with and without the application of uniaxial pressure. Less than 50 watts was required to internally ignite the samples using a TE{sub 102} microwave cavity mode. Uniaxial stresses in the range of 200-1400 psi were continuously applied along the vertical axis of some of the processed samples as the SHS reactions were initiated. SEM photomicrographs clearly indicate differences in the formation of whiskers and other microstructural features in the products obtained from microwave and conventional hot wire techniques. The x = 0 samples processed with fast and slow microwave heating rates reached higher densities than the conventionally processed samples.
Complete text of publication follows. The stability regime of the incommensurate phase of quartz is influenced by uniaxial stress. Hence, the phase transition can be induced under isothermal conditions by the application of external mechanical forces. Using real-time neutron scattering the time evolution of structural changes is investigated id detail during stress variations. The time dependent behaviour of the satellite reflection is compared with that one of the fundamental Bragg reflection which - via primary extinction - gives information about the perfection of the crystal. On increasing stress the perfection of the lattice is destroyed immediately while the modulated structure is built up with a delay of about 1 s. Decreasing the stress leads to a reverse behaviour. Moreover, there is evidence that under periodical load residual non-relaxed strain fields survive leading to a different temperature dependence as compared to static ...
Fe-Cu binary alloys are often used to mimic the behaviour of reactor pressure vessel steels. Their study allows identifying some of the defects responsible for irradiation-induced hardening. But recently the influence of manganese and nickel in low-Cu steels has been found to be important as well. In contrast with existing models found in the literature, which predict that hardening saturates after a certain dose, Fe alloys containing nickel and manganese irradiated in a material test reactor (BR2) show a continuous increase of hardening, up to doses equivalent to about 40 years of operation. Considerations based on positron annihilation spectroscopy analyses suggest that the main objects causing hardening in Cu-free alloys are most probably self-interstitial clusters decorated with manganese. In low-Cu reactor pressure vessel steels and in Fe-CuMnNi alloys, the main effect is still due to Cu-rich precipitates at low doses, but the role of manganese-related ...
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the ...
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the ...
The effects of the plasma nitriding with the formation of compound nitride and diffusion zones and of the boronising with the different ion doses on hydrogen distribution and hydrogen induced deterioration of a surface layer were examined in the case of Armco iron. Electrochemical studies of hydrogen permeation rate, hydrogen vacuum extraction measurements, optical and scanning microscopy, X-ray diffraction and elastic recoil detection analysis (ERDA) were used. Accumulation of entering hydrogen within the various constituent zones of the modified layer inhibits the hydrogen transport into the metal and thus, decreases the mean hydrogen content in the deeper zones and in the core. Hydrogen accumulation within the compact nitride zone causes the expansion of the nitride lattice, nitride phase transformation and deterioration. The ion boronising enhances the hydrogen effects in the plasma nitrided layers. Therefore, modification of the surface ...
Laser consolidation (LC) developed by National Research Council???s Industrial Materials Institute (NRC-IMI-London) since mid-1990s, is a laser cladding based rapid manufacturing and material additive process that could fabricate a ???net-shape??? functional metallic shape through a ???layer-upon-layer??? deposition directly from a computer aided design model without using molds or dies. In order to evaluate the LC processability of different materials, some representative nickel-based superalloys (IN-625, IN-718, IN-738, and Waspaloy), stainless steels (austenitic SS316L and martensitic SS420), and lightweight alloys (Ti???6Al???4V titanium alloy and Al-4047 aluminum alloy) have been investigated. Like other laser cladding based processes, due to process-induced rapid directional solidifi...
The effect of mean stress, or the stress ratio (R), on the fatigue-crack growth (FCG) behavior of #alpha#-aged and #omega#-aged microstructures of the beta titanium alloy Ti-10V-2Fe-3Al was investigated. While the mean stress had a negligible effect on the FCG behavior of the #alpha#-aged microstructure, a strong effect was observed in the #omega#-aged microstructure. In particular, the values of the threshold stress-intensity range (#DELTA#K_t_h) exhibited a strong dependence on R in the #omega#-aged microstructure, while this dependence was weak in the #alpha#-aged microstructure. These effects seem to arise primarily from fracture-surface roughness-induced crack closure. The crack closure levels for the #alpha#-aged microstructure were found to be very low compared to those for the #omega#-aged microstructure. Transmission electron microscopy and scanning electron microscopy studies of microstructures and fracture surfaces were performed to gain insight into the ...
Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister chromatid exchanges (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon prior ...
Experiments were performed to investigate the involvement of the cell membrane in the excision DNA repair process in Escherichia coli. Two membrane-binding drugs, procaine and phenethyl alcohol (PEA), inhibited liquid-holding recovery (LBR) in u.v.-irradiated E. coli wild-type and recA strains. In uvrB and polA strains where, after u.v.-irradiation, LHR was absent the two drugs had no effect. Both drugs markedly reduced the removal of u.v.-induced thymine dimers in the DNA of wild-type cells (H/r30). Analysis by alkaline sucrose gradients revealed that PEA inhibited the incision step in excision repair. In contrast, procaine had no effect on incision but apparently inhibited the late steps in excision repair. PEA dissociated DNA from the cell membrane, whereas procaine did not. The results suggest that the two drugs PEA and procaine inhibit LHR and the excision repair process operating on u.v.-induced damage in E. coli by at least two ...
We have developed a Bragg curve counter (BCC) equipped with an active cathode to extend the energy acceptance to lower energies than for a conventional BCC to measure differential cross-sections of fragment production reactions induced by tens of MeV protons. The signal from the active cathode providing the timing signal of fragment incidence and the time difference signal between the cathode and anode gives information on the fragment range in the BCC on the basis of electron drift time. Utilization of the range information made possible identification of fragments less than 0.5 MeV/u that is lower than the identification threshold of a conventional BCC technique. After investigations on fundamental properties of a newly constructed BCC using heavy ion beams and alpha-particles, this method was applied successfully to a fragment production measurement for 70 MeV proton-induced reactions on carbon. With this technique, the ...
The chemist and pharmacologist Fritz Hauschild developed the sympathomimetic agent Pervitin (metamphetamin) in the 1930s. Not only because of the abuse of the stimulant during the Second World War ("pilot's chocolate") it is one of the most controversial substances in drug history. Nearly forgotten are Hauschild's contributions to build up the drug system in the GDR. Although he was a convinced communist, the skilful pharmacologist gave very early warning of the imminent lack of innovation in the GDR pharmaceutical industry. A letter which he addressed to the Minister of Health, Max Sefrin (born 1913), did not lack explicitness. PMID:15997840
This study shows that the physical conditions necessary for thermal waves to materialize in Dual-Phase-Lagging porous media conduction are not attainable in a porous slab subject to a combination of constant heat flux and temperature (Neumann and Dirichlet) boundary conditions. It is demonstrated that the approximate equivalence between Dual-Phase-Lagging (DuPhlag) heat conduction model and the Fourier heat conduction in porous media subject to Lack of Local Thermal Equilibrium (La Lotheq) that suggested the possibility of thermal oscillations and resonance reveals a condition that cannot be fulfilled because of physical constraints. (author)
The accuracy of dose computation within the lungs depends strongly on the performance of the calculation algorithm in regions of electronic disequilibrium that arise near tissue inhomogeneities with large density variations. There is a lack of data evaluating the performance of highly developed analytical dose calculation algorithms compared to Monte Carlo computations in a clinical setting. We compared full Monte Carlo calculations (performed by our Monte Carlo dose engine MCDE) with two different commercial convolution/superposition (CS) implementations (Pinnacle-CS and Helax-TMS's collapsed cone model Helax-CC) and one pencil beam algorithm (Helax-TMS's pencil beam model Helax-PB) for 10 intensity modulated radiation therapy (IMRT) lung cancer patients. Treatment plans were created for two photon beam qualities (6 and 18 MV). For each dose calculation algorithm, patient, and beam quality, the following set of clinically relevant dose-volume ...
Bacillus licheniformis ?-glutamyltranspeptidase (BlGGT) undergoes an autocatalytic process to generate 44.9 and 21.7?kDa subunits; however, a mutant protein (T399A) loses completely the processing ability and mainly exists as a precursor. For a comprehensive understanding of their structural features, the biophysical properties of these two proteins were investigated by circular dichroism and fluorescence spectroscopy. Tryptophan fluorescence and circular dichroism spectra were nearly identical for BlGGT and T399A, but unfolding analyses revealed that these two proteins had a different sensitivity towards temperature- and guanidine hydrochloride (GdnHCl)-induced denaturation. BlGGT and the unprocessed T399A displayed T m values of 61.4?C and 68.1?C, respectively, and thermal unfolding of b...
The authors report the transient enhanced diffusion of supersaturated phosphorous in ion-implanted SPE grown Si. Precipitation proceeds rapidly to a metastable SiP phase, which can be converted to an orthorhombic form or re-dissolved by subsequent heat treatment. The effects are strongly temperature dependent, and consistent with the trapped interstitial model. The behavior of different dopants follow their relative interstitialcy diffusion coefficients. The results suggest that ion implantation induced point defects dominate over thermally activated point defects during low temperature and certain rapid thermal processing, controlling dopant deactiviation and diffusion in crystalline or amorphous silicon, and can also affect the SPE growth rate.
The mammalian placenta consists of different trophoblast cell types that assist in the variety of functions required for the maintenance of pregnancy. In rodents, labyrinthine trophoblasts of the placenta are especially important, because they are capable of differentiating into fused labyrinthine cells, which form the feto-maternal exchange surface. Even though the molecular signals triggering labyrinthine trophoblast differentiation are poorly understood, transforming growth factor-b (TGF-b) has been shown to be present in the placental environment and alter trophoblast development. In this study, we investigated the effects of TGF-b on the differentiation of the labyrinthine trophoblast stem cell lines SM10 and HRP-1. RT-PCR analyses demonstrated that while the molecular expression of l...
Several different aspects of the influence of the target backing on in-beam electron spectra following compound nuclear reactions induced by accelerated ions at tandem energies irradiating backed targets are discussed in detail. This discussion is illustrated by a few typical examples, such as "1"2C"5"+ and "3"1P"1"0"+ beams at 4 MeV/u bombarding Sn(+Be), Sn(+Au), Pb(+C) backed targets. Moreover, the relative influence of electron backscattering, electron Doppler shift and Doppler broadening as well as #delta#-electron emission on the low energy electron spectra (E_e#<=#100 keV) obtained under such conditions are investigated in the frame of the available experimental data. (orig.).
Many foods have been implicated in theories about the etiology of inflammatory bowel disease. While evidence has accumulated that nutritional factors as part of overall lifestyle changes may play a role in the growing incidence, no specific dietary recommendations except the promotion of breastfeeding can currently be given to decrease the risk of developing Crohn's disease or ulcerative colitis. For the treatment of Crohn's disease in children and adolescents, however, enteral feeding with a semi-elemental diet seems to be as effective as corticosteroids in inducing and maintaining remission. In the meta-analyses, advantages of one formula over the other are evened out, and more research is warranted into the anti-inflammatory properties of different nutrients, such as polyunsaturated fat...
Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the elderly accounting for the vast majority of dementia. Recently, many studies have implicated the role of inflammatory response, especially neuroinflammatory response in the development and progression of AD. However, the underlying mechanism of how inflammatory response induces AD is unknown. Kynurenine pathway is a major route of the amino acid tryptophan catabolism, resulting in the production of nicotine adenine dinucleotide and other neuroactive intermediates: quinolinic acid (QA) and kynurenic acid (KA). QA exerts different toxic effects, including over-activation of N-methyl-d-aspartate (NMDA) receptor and excitotoxicity, synaptic dysfunction and neuronal death. On the other hand, KA is identified as the only...
We combine establishment-level employment data with trade data by port to examine the impact of accession to the European Economic Community on the spatial distribution of UK manufacturing. We test the predictions from economic geography models of how external trade affects the spatial distribution of employment. We treat accession as a natural experiment which helps mitigate problems of endogeneity. Our results suggest that accession changed the country composition of trade and via the port composition induced an exogenous shock to different locations. In line with theory, we find that better access to export markets and intermediate goods increase employment while increased import competition decreases employment.
Irradiation of EP-823 (16Cr12MoWsiVNbB) ferritic-martensitic steel with 7-MeV Ni++ ions and with 30- and 70-keV He+ ions at a temperature of 500?C was followed by an increase in the microhardness, which was due to both radiation point defects and changes in the phase composition and the dislocation structure of the steel. It was found that the dependence of the largest relative increase in the microhardness on the concentration of radiation-induced point defects in the near-surface region of the steel under irradiation with different ions correlated with an analogous dependence of the surface segregation of silicon and chromium.
Until a decade ago, only the differential bobbin type eddy current probe was considered necessary for reliable heat exchanger tube inspection. The introduction of different tube materials, manufacturing processes and a variety of service induced failures has greatly increased the demands of eddy current testing. Optimized probe designs enhanced by improved instrumentation can help satisfy some of these demands. Some of the more difficult inspection problems are detection of circumferential cracks, fretting wear under non-ferromagnetic support plates and shallow internal defects. Reliable detection and sizing of such defects is often made more difficult by the fact they frequently occur in defect prone regions such as under tubesheets or support plates and in transition regions of finned tubes. Probe designs effective in overcoming these difficulties exist. This paper describes a number of such probes and their performance.
Depending on the soil environment, selenium (Se) can exist as several species differing greatly in bioavailability. Characterization of soil Se reserves is thus necessary in assessing the nutritional supply of this essential element. In low-Se areas, Se fertilization is an option for securing adequate Se nutrition. Fertilization is, however, challenged by the unknown fate of the residual Se. In this study, we aimed to clarify the Se status of selenate-fertilized field soils by fractionating soil Se into five pools: salt-soluble (KCl), adsorbed (KH2PO4/K2HPO4), organically associated (NaOH), elemental (Na2SO3) and recalcitrant Se (NaOCl). Changes induced in these fractions by repeated application of low selenate doses were examined by comparing samples collected from the same locations in 1...
This study correlates the post start cell performance and impedance with the cold start process in the subzero environment. The sequential failed cold starts are deliberately conducted as well as the start at small current density. Here the failed cold start means the cell voltage drops to or below zero within very short time during the start process. It is found that there are reversible performance losses for the sequential failed cold starts, while not obvious degradation and no recovery happen for the start at small current density. Using the thin film and agglomerate model, it is confirmed that this is due to the water blocking effect. Comparing the results from different start processes, a model with respect to the shifting of reactive region within the catalyst layer is applied to e...
We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at {gamma}{gamma} colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of {mu}{sup +}{mu}{sup -}, {tau}{sup +}{tau}{sup -}, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan{beta}-bar 5 (30) and large (small) charged Higgs-boson masses.
We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at #gamma##gamma# colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of #mu#"+#mu#"-, #tau#"+#tau#"-, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan#beta#-bar 5 (30) and large (small) charged Higgs-boson masses.
Many of the world's coral reefs suffered high coral mortality during the 1998 ENSO, with the highest mortality in the western Indian Ocean (WIO). A meta-analysis of field data on change in coral cover across the 1998 ENSO event was conducted for 36 major reef areas in the WIO, and relationship of the change with the historical sea-surface temperature (SST) variability investigated. WIO reefs were categorized into three major SST groups of differing coral cover change. Cover change was negatively associated with standard deviation (SD) SST until about SD 2.3, with increasing flatness of the SST frequency distributions. It increased with further increase in SD as the SST distributions became strongly bimodal in the Arabian/Persian Gulf area. The study indicates that environmental resistance/...
Intrusive degassing and recycling of degassed and dense magma at depth have been proposed for a long time at Stromboli. The brief explosive event that occurred at the summit craters on 9 January 2005 threw out bombs and lapilli that could be good candidates to illustrate recycling of shallow degassed magma at depth. We present an extensive data set on both the textures and the mineral, bulk rock and glassy matrix chemistry of the ?9 Jan? products. The latter have the common shoshonitic?basaltic bulk composition of lavas and scoriae issued from typical strombolian activity. In contrast they differ by the heterogeneous chemistry of their matrix glasses and their crystal textures that testify to crystal dissolution event(s) just prior magma crystallization upon ascent and eruption. Comparison...
In situ composites based on poly(ethylene 2,6-naphthalate) (PEN) and a thermotropic liquid crystal polymer (Vectra A950) were prepared by melt blending under different processing conditions. Thermal behaviour, mechanical and physical properties and morphology of the blends were investigated. The DSC analysis indicates that, as expected, Vectra enhances the crystallization process of PEN. Moreover, mechanical and thermal tests evidence the significant role of 20wt% Vectra on increasing the material performances; tensile properties, coupled with SEM, show that strength and modulus of PEN are significantly improved when Vectra domains are long and continuous fibrils. The overall results can be attributed to the compatibilisation of the system induced by the mixing conditions that affect the e...
Long before possible organic effects, exposure to ionizing radiations can provoke anxiety. In front of invisibility, the imagination quickly ignites. The terrorists have perfectly understood it. They are ready to use ionizing radiations as a weapon to remind traumatic images deeply rooted in people's memory. These images induce anxiety with all the clinical expressions connected to it. These symptoms require to be treated because of a possible anarchic development. For that purpose, plans have been elaborated to coordinate the different professional's actions. The coherence of medical management and communication aims to allow the most implicated people to find the way to face the events. When it is not possible, medico-psychological cells permit a specialized care. (author)
The first part of the study contains a literature compilation of more than 50 original publications reporting the radiation induced effects in 17 different high polymer materials and glass which are relevant in the manufacturing of medical devices or packing materials. The results collected demonstrate that high energy radiation, i.e. gamma- or X-rays, causes various physical and chemical alterations in high polymer materials. A detailed summary and discussion of the results of the original publications is not included in the present report, it will be presented in the second part of the study. Furthermore, the second part of the study will refer to the aspect of wholesomeness of irradiated medical devices or packing materials in a more general manner of representation. (orig.).
Two of eight differently prepared copper stabilizer samples, previously irradiated in the RTNS-II at LLNL, the IPNS-1 and the BSR at ORNL, have been irradiated to a fluence of 1.33 /times/ 10/sup 22/ n/m/sup 2/ at RTNS-II. During the course of the irradiation the samples were periodically removed (without warming) for measurements of the transverse magnetoresistance and returned for continued irradiation. This experiment extends the range of neutron-irradiation-induced resistivity by a factor of five over the previous experiments. A simple model is developed which reproduces the magnetoresistance results of all the experiments to an accuracy of 2.5%. 13 refs., 6 figs.
In this study, we evaluated the hypothesis that long term dietary restriction would have beneficial effects on the oxidative stress and antioxidant enzyme systems in liver, heart and kidney in adult male rats undergoing different intensities of swimming exercise. Sixty male, Sprague-Dawley rats were assigned as either dietary restricted on every other week day (DR) or fed ad libitum (AL) groups, and each group was further subdivided into sedentary, endurance swimming exercise training (submaximal exercise) and exhaustive swimming exercise (maximal exercise) groups. Animals in the submaximal exercise group swam 5 days/week for 8 weeks, while maximal exercise was performed as an acute bout of exercise. In parallel with the increase in the intensity of the exercise, the degree of lipid peroxi...
Abstract A series of polypropylene carbonate (PPC)/ZnO nanocomposite films with different ZnO contents were prepared via a solution blending method. The morphological structures, thermal properties, oxygen permeability, water sorption, and antibacterial properties of the films were investigated as a function of ZnO concentration. While all of the composite films with less than 5 wt % ZnO exhibited good dispersion of ZnO in the PPC matrix, FTIR and SEM results revealed that solution blending did not lead to a strong interaction between PPC and unmodified ZnO. As such, poor dispersion was induced in the composite films with a high ZnO content. By incorporating inorganic ZnO filler nanoparticles, the diffusion coefficient, water uptake in equilibrium, and oxygen permeability decreased as the ...
A prerequisite for a sensible estimate of moisture induced stresses in timber members is an accurate prediction of the members' moisture states during their service life. There are, however, an infinite number of possible moisture states for an arbitrary timber member in a natural varying climate. The naturally varying humidity is possible to describe as harmonic cycles, with different periods, superimposed. This work presents realizations of envelop curves over the possible moisture states in a timber member for some carefully chosen harmonic humidity variations. The calculations, on which the realizations were made, are based on a fully coupled transport model including a model for the influential sorption hysteresis of wood. A format containing required information suitable for assessin...
Zooplankton tolerant to ultraviolet radiation (UVR) could be indirectly affected by UVR through interactions with UV-sensitive species in the same ecosystem. In Lake Giles, Pennsylvania, USA, the calanoid copepod Leptodiaptomus minutus is more UVR tolerant than the cohabiting species Daphnia catawba and Cyclops scutifer. We asked whether L. minutus is affected by UV-induced mortality of a food competitor (D. catawba) or a predator of its nauplii (C. scutifer). We conducted two in situ enclosure experiments with six treatments: L. minutus alone, L . minutus + Daphnia and L. minutus + Cyclops in the presence and absence of UVR. There were few differences in survival among treatments in Experiment 1, which had enhanced food and a cumulative UVR (320 nm) dose of 9.3 kJ m-2. In Experiment 2, wh...
Polysomaty analysis of the succulent portulaca (Portulaca grandiflora Hook.) plant was carried out using flow cytometry. For both diploid and tetraploid plants, mature leaf tissue was found to have a higher level of polysomaty than young leaf tissue. Mesophyll (MP), bundle sheath (BSP) and water storage protoplasts (WSP) were isolated from leaf tissues of diploid portulaca plants. WSP had a higher degree of endopolyploidization than MP and BSP. The ploidy distribution was also variable in different floral organs. Tetraploid plants artificially induced by colchicine treatment showed a decline in the degree of polysomaty compared to diploid plants. Tetraploid plants had more spherical leaves, a larger number of petals and lower pollen fertility than diploid plants. PMID:10936528
We have performed polarized neutron diffraction measurements on the intermediate valence compound CePd{sub 3} using the D3 spectrometer at the ILL. The results show that at low temperatures, 1.7 K, as well as at 100 K, the field-induced magnetic amplitudes measured in a field of 4.6 T could be interpreted in terms of two contributions: a 4f-type contribution with a Ce{sup 3+} form factor, and an extra delocalized contribution (relatively narrow in q-extent). In particular, we find that the values of the 4f moment deduced from the extrapolation of the neutron data to Q=0 are systematically lower than the values deduced from bulk magnetization measurements performed on the same sample. This difference can be ascribed to a possible positive polarization of the conduction band which is similar at both temperatures.
Stainless steels can get pitting corrosion in halide containing solution, which make them a big risk in industrial production. Many investigations were made in the past in order to understand processes involved in pitting corrosion, pit initiation and pit growth. Results about the influence of alloying elements, their contents, the state of the structure, the condition of the surface, the content of chloride, the temperature, the pH-value, the velocity of flow and of the oxidizer on the chloride induced pitting corrosion of passive stainless steels are presented. Electrochemical measurements and the application of surface analytical methods (SEM, SAM, XPS) with high lateral resolution are carried out. A part of the samples received a diffusion annealing in order to obtain reproducible results. Pitting Resistance Equivalents (PRE) - Pitting Index - with different multipliers are given and discussed critical. An electrochemical method for ...
Male meadow voles housed in a long photoperiod (14 h light/day, LP) preferred female to male odors, whereas males maintained in a short photoperiod (10 h light/day, SP) did not display preferences for odors of either sex. These odor-preference patterns matched those of free-living males during spring and autumn, respectively. The preference of LP male voles for female over male odors was eliminated by gonadectomy and reinstated by treatment with testosterone. In SP males, although gonadectomy did not affect odor choices, a preference for female odors was induced by testosterone treatment. Treatment with estradiol did not alter odor preferences of LP or SP males. In conjunction with previous result, the present findings suggest that hormonal responsiveness of neural substrates that control odor preferences are sexually dimorphic and may reflect sex differences in reproductive strategies. PMID:1615048
Hemolysis induced by long-wave ultraviolet radiation (UVA) and 8 different commercial tetracycline derivatives was studied in a model using human red blood cells. Demethylchlortetracycline and doxycycline were shown to have pronounced hemolytic properties causing 88% and 85% hemolysis, respectively, at a concentration of 50 micrograms/ml and 72 J/ cm2 of UVA. Tetracycline, oxytetracycline, and chlortetracycline caused maximally 18% hemolysis at 200 micrograms/ml and lymecycline only 7% at 100 micrograms/ml. Methacycline showed intermediate hemolytic effect of 36% at 200 micrograms/ml. Minocycline had no hemolytic effect whatsoever. These experimental data correlate very well with clinical reports and comparative phototoxicity trials in humans. Photohemolysis may thus be of value for predicting tetracycline phototoxicity.
Background, Aim, and Scope The identification and assessment of environmental tradeoffs is a strongpoint of life cycle assessment (LCA). A tradeoff made in many product systems is the exchange of potential for occupational accidents with the additional use of energy and materials. Net benefits of safety measures with respect to human health are best illustrated if the consequences avoided and health impacts induced by additional emissions are assessed using commensurable metrics. Our aim is to develop a human health impact indicator for offshore crane lifts. Crane lifts are a major cause of accidents on offshore oil and gas (O & G) rigs, and health impacts from crane lift accidents should be included in comparative LCA of O & G technologies if the alternatives differ in the use of crane li...
To our knowledge, the fluorescence studies of lanthanides in LiCl-KCl eutectic molten salt at a high temperature are not reported yet. The fluorescence of the lanthanide-ions was generally decreased when the temperature was increased. Moreover, the fluorescence of the lanthanides was strong when the sample was solidified to or from the melt. The temperature, where the fluorescence was decreased, was identified to be different depending on the species of the lanthanides and the substrates was considered to possibly be from quenching of the fluorescence due to either the collisions of melted samples induced by high temperature media or the re-absorption of fluorescence by the samples. Several comparison experiments were performed to explain and understand this phenomenon and improve the fluorescence. In this way, an on-line monitoring of chemical species and the concentration for lanthanides elements in molten salt media of pyrochemical process ...
This study highlights a methodology to detect the transplanting operation of wetland rice at a regional scale using SSM/I brightness temperature in frequencies like 19, 37 and 85 GHz with vertical polarization. A cloud removal algorithm was used to make weekly composites of the brightness temperature, which were used to estimate the soil wetness index (SWI). Flooding of rice fields with water for transplanting induces very high change in SWI due to contrasting dielectric constant of water (80) and soil (4). Different weather conditions and fractional wet area under the footprint of sensor affect SWI, hence absolute value of SWI was not adequate. Therefore, multi-year SWI anomaly was used to generate a threshold value of SWI change to detect when SWI change between two consecutive weeks was...
Nitric oxide (NO) and related molecules such as peroxynitrite, S-nitrosoglutathione (GSNO), and nitrotyrosine, among others, are involved in physiological processes as well in the mechanisms of response to stress conditions. In sunflower seedlings exposed to five different adverse environmental conditions (low temperature, mechanical wounding, high light intensity, continuous light, and continuous darkness), key components of the metabolism of reactive nitrogen species (RNS) and reactive oxygen species (ROS), including the enzyme activities L-arginine-dependent nitric oxide synthase (NOS), S-nitrosogluthathione reductase (GSNOR), nitrate reductase (NR), catalase, and superoxide dismutase, the content of lipid hydroperoxide, hydrogen peroxide, S-nitrosothiols (SNOs), the cellular level of N...
A theoretical analysis of formation and symmetry transformations is presented for Wigner molecules with N = 2,..., 20 electrons confined in quantum dots at high magnetic fields. Using the unrestricted Hartree-Fock method with the multicentre Gaussian basis, we have found that Wigner molecules with N {>=} 6 abruptly change their shape and symmetry with an associated jump in the first derivative of the ground-state energy, i.e. they undergo phase transitions. In particular, the phases of the Wigner molecules obtained just after emerging from the maximum-density droplet (MDD) phase possess a different symmetry from that formed at a high magnetic field. We show that the properties of the electron-electron interaction energy demonstrate very well both the breakdown of the MDD and the quasi-classical character of the Wigner molecule in the high magnetic field. Possible mechanisms of the MDD decay are discussed.
By using megaelectronvolt /sup 4/He ion backscattering techniques and transmission electron microscopy, the authors have investigated the interactions of ion beams with thin film structures in a number of silicide-forming systems. The mixed layer was found to be an equilibrium compound for near-noble metals and an amorphous phase for refractory metals. Differences in behavior have also been observed in near-noble metal systems. For palladium, the Pd/sub 2/Si phase grew with ion dose and remained crystalline up to high dose. For nickel, the compound Ni/sub 2/Si was formed initially and became amorphous on prolonged irradiation. All the results indicate the significance of atomic mobility at target temperatures in determining the phase formation and in explaining the sensitivity of the silicides to ion bombardment.
By using megaelectronvolt "4He ion backscattering techniques and transmission electron microscopy, the authors have investigated the interactions of ion beams with thin film structures in a number of silicide-forming systems. The mixed layer was found to be an equilibrium compound for near-noble metals and an amorphous phase for refractory metals. Differences in behavior have also been observed in near-noble metal systems. For palladium, the Pd_2Si phase grew with ion dose and remained crystalline up to high dose. For nickel, the compound Ni_2Si was formed initially and became amorphous on prolonged irradiation. All the results indicate the significance of atomic mobility at target temperatures in determining the phase formation and in explaining the sensitivity of the silicides to ion bombardment. (Auth.).
This paper reviews different helium-cooled first wall and blanket designs; and compares the selection of structural materials. The authors found that the solid breeder, SiC-composite material option generates the lowest amount of induced radioactivity and afterheat and has the highest temperature capability. When combined with the direct cycle gas turbine system, it has the potential to be the most economical fusion system and can compete with advanced fission reactors. When compared to martensitic steel and V-alloy, SiC-composite is the least developed of these three structural materials, a focused development effort will be needed. Fundamental research has begun in addressing the issues of optimized composite materials, irradiation effects, leak tightness and low activation braze materials. Development of helium-cooled high heat flux components and further development of the direct cycle gas turbine system will also be needed.
339 CT und 95 MRT examinations in 210 partients were evaluated retrospectively to determine the value of CT and MRT for follow-up of head and neck tumors and for diagnosing recurrences. Semi-quantitative evaluation of tumor extent during and after radiotherapy showed advantages for MRT since changes induced by treatment, particularly oedema, produced less contrast loss in the images. CT had a sensitivity of 81% for the recognition of recurrences; this was 92% for MRT. Specificity for CT was 76% and for MRT 86%. Concerning the reliability of individual diagnostic criteria, space occupying lesions were the most valuable in CT diagnosis. For MRT, space occupying lesions and infiltration into neighbouring structures were of equal value. Because of differences in the nature of the signals, MRT proved better than CT in characterising recurrent masses and this improved the differentiation between scarring and local tumour recurrence. (orig.).
The authors explain the bankers' point of view of the financial and economic aspects of developments in the energy sector, discussing the financing of natural gas pipelines (Muro, Megal, etc.), of nuclear power plant construction, of projects in the oil supply sector, and of pollution abatement measures and equipment for the power industry and other industries. The different financial situations of small firms or large firms supplying pollution control equipment are discussed referring to the financing schemes to be set up, explaining among other things the profitability assessment taking into account long-term development or delays in return on capital investment from borrowed funds as induced, e.g., by delays in the licensing procedure. Future demand for borrowed capital for pollution control or nuclear power plant development is difficult to assess by the banking circles. (orig./RST).
The authors examined the effects of large escapements of sockeye salmon in to the Kenai River and into Red and Akalura Lakes on Kodiak Island. Estimated smolt numbers outmigrating from the Kenai River decreased from 30 million in 1989 to under 500,000 in 1992. Decreased overwintering survival of age-0 juvenile sockeye salmon rearing in Skilak and Kenai lakes is the major contributor to this decline. Preliminary examination of limnological data from Skilak and Kenai Lakes provided no obvious explanation for this major decline in winter survival of juvenile sockeye. Due to differences in diel vertical migration of zooplankton among glacial lakes on the Kenai Peninsula with varying planktivores levels, the authors hypothesize that behavioral changes of zooplankton induced by predation may be a major contributor to the juvenile sockeye decline.
The investigation of steam, water, and air flow characteristics in horizontal channel is a part of major investigations program at the Lithuanian Energy Institute. The objective of this program is to identify condensation effects on two-phase flow stability and to predict conditions when rapid condensation could be induced in two-phase condensable flow. This article presents investigation of steam-water and air multiphase flow in nearly horizontal rectangular channel. The experimental data for pressure drop and interfacial and wall shear stresses in the channel with uniform distribution of void fraction are presented in this paper. Overall channel dimensions are length = 1.2 m, width = 0.02 m, height = 0.1 m; however, the test section was about 0.84 m in length. Three different flow types ...
Temperature variations due to climate changes are a major cause of movements in a concrete structure, both in the longitudinal and transversal directions and between different parts of the structure. If these movements are restrained, stresses will be induced which may contribute to cracking. The movements are caused by complex interactions of several factors such as solar radiation, air temperature, long-wave heat radiation and wind speed. To predict the varying thermal conditions in a concrete structure a finite element model has been used. A validation of the model has been performed using field measurements in a concrete slab together with climate data from the Swedish Meteorological and Hydrological Institute to be able to use the model for simulations over long time periods and for s...
Fatigue crack growth tests of three ferrite-pearlite steels with different size and spacing of pearlite particles, which were uniformly distributed in the ferrite matrix, were carried out to investigate the effect of microstructure on fatigue crack growth behavior in the Paris regime. The fatigue crack growth rates for the three materials did not coincide with each other, even when the crack growth curves were arranged by the effective stress intensity factor range. From in situ observations, crack tip stress shielding phenomena, such as interlocking and branching, were found on the crack wake, which enhanced fatigue crack growth resistance. A small size and spacing of pearlite particle seemed to induce small but frequent crack deflections, which resulted in crack closure phenomena. On the...
The varestraint cracking test was carried out to assess the hot cracking tendency of alloy 800 at different welding conditions and augmented strain levels. The test results revealed that the hot cracking susceptibility of alloy 800 increases with increasing the heat input and augmented strain levels. This emphasizes the role of constraint either internally induced or externally applied to the welded structure. A cracking threshold or the minimum augmented strain ([epsilon][sub min]) below which no hot cracking takes place has been found to be 0.25 for alloy 800. Also, the Critical Strain Rate to Time (CSS) required to cause cracking was found to be 6.42x10[sup -3] sec[sup -1] at welding condition of 100 Amp, 13 Volt and 140 mm/min. (author).
The varestraint cracking test was carried out to assess the hot cracking tendency of alloy 800 at different welding conditions and augmented strain levels. The test results revealed that the hot cracking susceptibility of alloy 800 increases with increasing the heat input and augmented strain levels. This emphasizes the role of constraint either internally induced or externally applied to the welded structure. A cracking threshold or the minimum augmented strain (#epsilon#_m_i_n) below which no hot cracking takes place has been found to be 0.25 for alloy 800. Also, the Critical Strain Rate to Time (CSS) required to cause cracking was found to be 6.42x10"-"3 sec"-"1 at welding condition of 100 Amp, 13 Volt and 140 mm/min. (author).
With the aim to study and to improve LIBS capability for detecting residues of energetic compounds in air surrounding, nine types of explosives and some potential interferents, placed in small quantities on a metallic support, were interrogated by a laser. Shot-to-shot behavior of the line intensities relative to the sample constituents was studied. The detected plasma was not stoichiometric and the line intensities, as well as their ratios, were changing even for an order of magnitude from one sampling point to another, particularly in the case of aromatic compounds. We explained some sources of such LIBS signal's behavior and this allowed us to establish a data processing procedure, which leads to a good linearization among the data sets. In this way, it was possible to determine some re...
The examination of the high-temperature properties of the alloy Alloy 800HT has shown that both the creep performance and the microstructure of the material can be purposefully set by the initial heat treatment. At the high temperatures applied, (700-900 C), a rapid softening process sets in induced by carbide precipitation, stabilization, and coarsening. This softening process causes creep velocities strongly accelerating as a function of duration of the heat treatment prior to the creep test. The identified cause of the softening effect is a change in particle size that could be verified by SEM and TEM. It is shown that two different carbide precipitate size classes are responsible for the softening effect. While the precipitates dectable by TEM become effective primarily via interactions with dislocations, the carbide precipitates detectable only by SEM contribute to a hardening of the grain boundaries and the matrix.(orig./CB)
Purpose To study the chemical modifications induced upon irradiation of solid human insulin at radiosterilization doses and investigate the influence of the absorbed dose on radiolysis. Materials and Methods Volatile radiolytic products were monitored by gas chromatography coupled with mass spectrometry (GC-MS) and non-volatile products by two different high performance liquid chromatography (HPLC) methods: the formation of higher molecular weight proteins was assessed by size exclusion liquid chromatography whereas assays for related compounds and chemical potency tests were carried out using reverse-phase HPLC-UV. Conformational changes were investigated by measurements of circular dichroism. Results After gamma irradiation at 10?kGy, the recovery of insulin was 96.8%; higher molecular w...
The surface permeability of concrete walls and floors in houses was measured with a specially designed permeameter, based on measuring the air-flow induced by a pressure difference across a temporary test seal applied to a surface. The permeability of bulk concrete is 10"-"1"6 m"2. Areas free of surface defects had permeability ranging from 10"-"1"4 to 10-"1"6 m"2. However, surface defects are common on concrete wall surfaces, which increase the permeability to >10"-"1"2 m"2. This is too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Satisfactory seals require either extended contact width or mechanical removal of the surface layer. (orig.). (2 figs., 1 tab.).
Radiation protection of the personnel who will perform interventions in the LHC Beam Cleaning Insertions is mandatory and includes the design of equipment and the establishment of work procedures. Residual dose rates due to activated equipment are expected to reach significant values such that any maintenance has to be planned and optimized in advance. Three-dimensional maps of dose equivalent rates at different cooling times after operation of the LHC have been calculated with FLUKA. The simulations are based on an explicit calculation of induced radioactivity and of the transport of the radiation from the radioactive decay. The paper summarizes the results for the Beam Cleaning Insertions and discusses the estimation of individual and collective doses received by personnel during critical interventions, such as the exchange of a collimator or the installation of Phase 2. The given examples outline the potential and the need to optimize, in an ...
Application of gamma radiation as a physical method of disinfestations against melon flies was recognized as a potential quarantine treatment. At 50 Gy, oocytes showed degeneration one day after treatment whereas seven-day-old oocytes did not differ greatly in appearance from control groups. Abnormal enlargement of trophocyte cells and vacuolization of oocytes occurred predominantly following the treatment with 100 and 150 Gy. One day after treatment with 150 Gy trophocytes underwent hypertrophy and hyperplasia. Irradiation at 100 and 150 Gy reduced the fertility to almost zero percent in the female melon flies.(authors)
The heating of water layer using microwave oven with a rectangular waveguide has been studied both numerically and experimentally. The mathematical model is validated with the experimental data. The transient Maxwell's equations are solved by using the Finite Difference Time Domain (FDTD) method to describe the electromagnetic field inside the waveguide and sample. The temperature profile and velocity field within sample are determined by the solutions of the momentum, energy and Maxwell's equations. In this study, the effects of physical parameters, e.g. microwave power level, placement of sample inside the waveguide, volume of sample, are studied. The distribution of electric field, temperature profile and velocity field are presented in details. The results show good agreement between s...
Mono-layers of stearic and behenic acids and mixtures of them in different proportions, deposited with the Langmuir-Blodgett technique, were used to study the alignment and the alignment dynamics in nematic liquid crystal cells. A relaxation process from a splay-bend flow induced metastable orientation to the homeotropic one occurs. The lifetime of the metastable state was found to depend on the mono-layer composition. The transition between the homeotropic and the conical anchoring was found to be irreversible in the case of the mixed aligning mono-layers: on cooling from the isotropic phase a quasi-planar nematic state (schlieren texture) appears. It is stable in a range of a few degrees below the clearing point and, on decreasing the temperature, relaxes to the homeotropic state in form of expanding domains.
We propose a combined experimental (Atomic Force Microscopy) and theoretical study of the structural and dynamical properties of nucleosomes. In contrast to biochemical approaches, this method allows to determine simultaneously the DNA complexed length distribution and nucleosome position in various contexts. First, we show that differences in the nucleo-proteic structure observed between conventional H2A and H2A.Bbd variant nucleosomes induce quantitative changes in the in the length distribution of DNA complexed with histones. Then, the sliding action of remodeling complex SWI/SNF is characterized through the evolution of the nucleosome position and wrapped DNA length mapping. Using a linear energetic model for the distribution of DNA complexed length, we extract the net wrapping energy of DNA onto the histone octamer, and compare it to previous studies.
The rolls and stand deflections induced by rolling force lead to a significant decrease in the radius prediction accuracy of the ring product in the in-plane roll-bending of strip. To precisely predict the deflections and control the radius, a new analytical model is developed. Numerical implementation is presented to solve the theoretical rolling force, the deflections as well as the inherent force-deflection relationship considering the interactions of the strip workpiece, the rolls and the stand. A series of profile measurements of the formed ring parts are made to assess the accuracy of the predicted deflections. Different control approaches are used in the experiments to validate the radius control model. The experimental results show that the model is reliable to control the radii wi...
T-2 toxin, a highly toxic member of the type-A trichothecenes, is produced by various Fusarium moulds that can potentially affect human health. It is strongly cytotoxic for human hematopoietic progenitors. Alimentary toxic aleukia (ATA), a disease typically associated with human, is primarily induced by T-2 toxin. A comparison of the metabolism of T-2 toxin incubated with hepatocytes of rats, piglets, chickens, and the hepatic subcellular fractions (microsomes and cytosol) of piglets, chickens, rats, and carp (common carp and grass carp) was carried out. The activities of the recombinant pig CYP3A29 on the transformation of T-2 and HT-2 toxins were preliminary studied. Metabolites were identified by novel LC/MS-IT-TOF. Qualitative similarities and differences across the species were observ...
Between December 2001 and May 2004, a ventilation experiment (VE) was performed in the Mont Terri Underground Research Laboratory (URL) and co-financed by the Commission of the European Communities. The objective was to investigate the desaturation of consolidated clay formations in consequence of the ventilation of underground openings of a repository in such a formation. The results of the geoelectric measurements performed in the second phase of the Mont Terri ventilation test can be summarized as follows: Geoelectric tomography has been found suitable for monitoring ventilation-induced saturation changes in the Opalinus clay. During ventilation with dry air a desaturation down to below 50% could be detected in both desaturation cycles. The desaturated zone extends less than 0.5 m into the rock around the microtunnel. During the second resaturation phase, ventilation with humid air led to quick resaturation at the tunnel surface, while resaturation of the rock ...
Between December 2001 and May 2004, a ventilation experiment (VE) was performed in the Mont Terri Underground Research Laboratory (URL) and co-financed by the Commission of the European Communities. The objective was to investigate the desaturation of consolidated clay formations in consequence of the ventilation of underground openings of a repository in such a formation. The results of the geoelectric measurements performed in the second phase of the Mont Terri ventilation test can be summarized as follows: Geoelectric tomography has been found suitable for monitoring ventilation-induced saturation changes in the Opalinus clay. During ventilation with dry air a desaturation down to below 50% could be detected in both desaturation cycles. The desaturated zone extends less than 0.5 m into the rock around the microtunnel. During the second resaturation phase, ventilation with humid air led to quick resaturation at the tunnel surface, while resaturation of the rock ...
The role of the HCR system in the repair of prelethal lesions induced by UV light, #gamma# radiation and alkylating agents was studied in the Bacillus subtilis SPP1 phage, its heat sensitive mutants (N3, N73 nad ts_1) and corresponding infectious DNA. The survival of phages and their transfecting DNA after treatment with UV light is substantially higher in hcr"+ cells than in hcr cells, the differences being more striking in intact phages than in their transfecting DNA's. Repair inhibitors reduce survival in hcr"+ cells: caffeine lowers the survival of UV-irradiated phage SPP1 in exponentially growing hcr"+ cells but has no effect on its survival in competent hcr"+ cells; acriflavin and ethidium bromide decrease the survival of the UV-irradiated SPP1 phage in both exponentially growing and competent hcr"+ cells to the level of survival observed in hcr cells; moreover, ethidium bromide lowers the number of infective centres in hcr"+ cells of the ...
Objectives: We have previously shown that chronic exposure to ambient fine particulate matter (less than 2.5 ?m in aerodynamic diameter, PM(2.5)) pollution in conjunction with high-fat diet induces insulin resistance through alterations in inflammatory pathways. In this study we evaluated the effects of PM(2.5) exposure over a substantive duration of a rodent's lifespan and focused on the impact of long-term exposure on adipose structure and function.Methods and Results: C57BL/6 mice were exposed to PM(2.5) or filtered air (FA) (6 hours/day, 5 days/week) for duration of 10 months in Columbus, OH. At the end of the exposure, PM(2.5)-exposed mice demonstrated insulin resistance (IR) and a decrease in glucose tolerance compared with the FA-exposed group. Although there were no significant differences in circulating cytokines between PM(2.5)- and FA-exposed groups, circulating adiponectin and leptin were significantly decreased in PM(2.5)-exposed ...
We carried out a feeding study in rats aimed at extending our aboservations of contaminant-induced immunosuppression in harbour seals. Two herring batches were freeze-dried, supplemented and fed to female adult PVG rats for a period of 4 1/2 months. Daily contaminant intakes of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQ) were estimated to be 0.3 ng/kg body weight and 1.6 ng/kg in the Atlantic and Baltic groups, respectively. At the end of the feeding experiment, no contaminant-related changes in spleen CD{sub 4}{sup +}/CD{sub 8}{sup +} cellularity, natural killer cell activity, or mitogen-induced proliferative responses of thymus or spleen cells could be detected. However, total thymocyte numbers and thymus CD{sub 4}{sup +}/CD{sub 8}{sup +} ratios were reduced in the Baltic group. A novel model was established to assess the specific T-cell response to rat cytomegalovirus (RCMV). When applied to the feeding study, no ...
The authors have investigated insulin receptor phosphorylation in differentiated cultured BC3H-1 myocytes. As for other insulin-responsive cell systems in partially purified wheat germ agglutinin receptor preparations, insulin stimulates the phosphorylation of its own receptor (95K ..beta..-subunits) in a dose dependent manner (0-400 nM), as identified by immunoprecipitation with antiinsulin receptor antibodies and SDS-PAGE. In the same preparations they show that 12-0-tetradecanyl phorbol acetate (TPA), which in many respect ..beta..-subunits in the same dose dependent manner (0-5 ..mu..M). In addition, antiinsulin receptor antibodies (B-10) also induced phosphorylation of mimics insulin action, also induced phosphorylation of the insulin receptor and HPLC tryptic maps of the /sup 32/P-labeled ..beta..-subunit were identical to those for insulin-induced receptor phosphorylation. However, while insulin and TPA are potent ...
Full text: DNA rearrangement events leading to chromosomal aberrations are central to ionizing radiation-induced cell death. Although DNA double-strand breaks are probably the lesion that initiates formation of chromosomal aberrations, little is understood about the molecular mechanisms that generate and modulate DNA rearrangement. Examination of the sequences that flank sites of DNA rearrangement may provide information regarding the processes and enzymes involved in rearrangement events. Accordingly, we developed a method using inverse PCR that allows the detection and sequencing of putative radiation-induced DNA rearrangements in defined regions of the human genome. The method can detect single copies of a rearrangement event that has occurred in a particular region of the genome and, therefore, DNA rearrangement detection does not require survival and continued multiplication of the affected cell. Ionizing ...
Spice extracts under the form of essential oils were tested for their efficiency to increase the relative radiosensitivity of Listeria monocytogenes and Escherichia coli O157H7 in culture media. The two pathogens were treated by gamma-irradiation alone or in combination with oregano essential oil to evaluate their mechanism of action. The membrane murein composition, and the intracellular and extracellular concentration of ATP was determined. The bacterial strains were treated with two irradiation doses: 1.2 kGy to induce cell damage and 3.5 kGy to cause cell death for L. monocytogenes. A dose of 0.4 kGy to induce cell damages, 1.1 kGy to obtain viable but nonculturable (VBNC) state and 1.3 kGy to obtain a lethal dose was also applied on E. coli O157H7. Oregano essential oil was used at 0.020% and 0.025% (w/v), which is the minimum inhibitory concentration (MIC) for L. monocytogenes. For E. coli O157H7, a concentration of 0.006% and 0.025% ...
Oxidative stress is demonstrated to be involved in the pathophysiological mechanism of erectile dysfunction (ED). Quercetin, a potent bioflavonoid, has been reported to have the antioxidant role. In the present study, we examined the effect of quercetin on ED and oxidative stress in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in Sprague-Dawley rats with a single intravenous injection of STZ. The diabetic rats were then randomized to diabetic group and quercetin therapy groups which were treated with quercetin at different doses of 5, 20 and 50mg/kg per day respectively. At the end of the 8th week, erectile function was assessed by measuring the rise in intracavernous pressure (ICP) following cavernous nerve electrostimulation. Superoxide dismutase (SOD) activity, thiobarbituric acid-reacting substance (TBARS) and nitrite and nitrate (NOx) levels were measured in cavernosum tissue. Endothelial NO ...
Glycyrrhiza glabra root is one of the common traditional Chinese medicines and used as flavoring and sweetening agents for tobaccos, chewing gums, candies, toothpaste and beverages. While glycyrrhizin is one of the main components in the extract of G. glabra root and has been characterized, the other components have not been well characterized. The mechanism of growth activation of breast cancer MCF-7 cells, including the activation of Erk1/2 and Akt, and the transcriptional regulation of estrogen-responsive genes, was examined by means of sulforhodamine B, luciferase reporter gene, real-time RT-PCR and Western blotting assays after the induction of the cells with the extract of G. glabra root. The extract has similar activity to that induced by 17beta-estradiol (E(2)), although glycyrrhizin did not show such an activity. Moreover, the estrogen receptor alpha-dependent neurite outgrowth induced by the extract was similar to that by E(2), ...
Effects of swimming exercise training on left ventricular contraction and relaxation, the incidence of spontaneous defibrillation and the ventricular fibrillation threshold were studied in the isolated, perfused rat heart. The heart/body weight ratio was 4.8 +/- 0.4 x 10(-3) in swimmers compared with 3.9 +/- 0.6 x 10(-3) in sedentary controls (p less than 0.0005). The spontaneous heart rate was lower in isolated hearts of trained animals (222 +/- 18 bpm compared with 244 +/- 28, p less than 0.05). Left ventricular systolic pressure was higher in trained hearts and the rate of ventricular relaxation enhanced (p less than 0.05). The ventricular fibrillation threshold was 7.2 +/- 5.2 and 10.8 +/- 6.1 mamp in hearts of swimmers and controls, respectively, the difference not being significant. The incidence of spontaneous defibrillation was not significantly different between the two groups. It is concluded that, while swimming ...
In experiments designed to detect new mutations affecting hemoglobin, we irradiated the male or female parent in reciprocal crosses of two mouse strains that differ in alleles at the hemoglobin (Hba, Hbb) loci as well as at five other specific loci. Offspring were analyzed for hemoglobin properties (electrophoretic pattern, solubility, crystal pattern), serum albumin differences, erythrocyte lysis, reticulocyte count, and external appearance. Five hemoglobin variants were found among the mutants. In three, the genetic contribution from the irradiated father was not expressed with regard to the #alpha#-chain; one carried a tandem duplication (the first known case in the mouse) involving Hbb; and one probably resulted from double nondisjunction of chromosome 7. The finding that major chromosome aberratios can mimic hemoglobin mutations indicates the need, in similar experiments, to follow F_1 screening with thorough cytogenetic analysis. The ...
We discuss the estimation of galaxy correlation properties in several volume limited samples, in different sky regions, obtained from the Fourth Data Release of the Sloan Digital Sky Survey. The small scale properties are characterized through the determination of the nearest neighbor probability distribution. By using a very conservative statistical analysis, in the range of scales [0.5,~30] Mpc/h we detect power-law correlations in the conditional density in redshift space, with an exponent \\gamma=1.0 \\pm 0.1. This behavior is stable in all different samples we considered thus it does not depend on galaxy luminosity. In the range of scales [~30,~100] Mpc/h we find evidences for systematic unaveraged fluctuations and we discuss in detail the problems induced by finite volume effects on the determination of the conditional density. We conclude that in such range of scales there is an evidence for a smaller power-law index ...
We performed histological examination of 69 samples of Acropora sp. manifesting different types of tissue loss (Acropora White Syndrome-AWS) from Hawaii, Johnston Atoll and American Samoa between 2002 and 2006. Gross lesions of tissue loss were observed and classified as diffuse acute, diffuse subacute, and focal to multifocal acute to subacute. Corals with acute tissue loss manifested microscopic evidence of necrosis sometimes associated with ciliates, helminths, fungi, algae, sponges, or cyanobacteria whereas those with subacute tissue loss manifested mainly wound repair. Gross lesions of AWS have multiple different changes at the microscopic level some of which involve various microorganisms and metazoa. Elucidating this disease will require, among other things, monitoring lesions over time to determine the pathogenesis of AWS and the potential role of tissue-associated microorganisms in the genesis of tissue loss. Attempts to experimentally ...
This work concerns the study of the nuclear superdeformation phenomenon in the rare earth region (A {approx} 150). The superdeformed (SD) states in Gadolinium and Dysprosium isotopes were produced via heavy-ion induced reactions and studied with the (EUROGAM EUROpean GAmma-ray Microscope) gamma multidetector array. Precise level attenuation method (DSAM). From the derived quadrupole moments, we find large differences in deformation between the yrast bands in neighbour nuclei explained in terms of the case of nuclei corresponding to an axis ratio of 2:1, the shell gaps are not fixed at a specific particle number and deformation. Furthermore the present results indicate that the deformations associated with identical bands are different supporting the picture that mass and deformation changes tend to compensate in SB bands with the same moments of inertia. (author). 114 refs.
Chloride-induced pitting corrosion of stainless steel (Materials No. 1.4301 and 1.4571) was investigated with the aid of chronopotentiostatic tests. Oxide films upon the surface (temper colours), addition of inhibitors (sulphate and nitrate) and temperature were the testing variables. Two different critical pitting potentials have been found, which give information on the potential ranges for stable passivity, latent and stable pitting corrosion. The results only indicate a small effect of Mo content of the material and test temperature. The inhibitors (sulphate and nitrate) have a marked effect. Specimens with a clean surface produced by pickling are markedly more resistant against pitting corrosion than specimens with a yellow temper colour, whereas the difference in corrosion resistance between yellow and blue films is relatively small. The width of the critical potential range for pitting corrosion generally increases ...
A mathematical interaction model, validated by experimental results, was developed to modeling the metal uptake by plants and induced growth decrease, by knowing metal in soils. The model relates the dynamics of the uptake of metals from soil to plants. Also, two types of relationships are tested: total and available metal content. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality with a satisfactory approach. Data are taken from soils treated with Cd and Ni for ryegrass (Lolium perenne, L.) and oats (Avena sativa L.), respectively. Concentrations are measured in the aboveground biomass of plants. In the latter case, the concentration of metals in different parts of the plants (tillering, shooting and earing) is also modeled. At low concentrations, the effects of metals are moderate, and the dynamics appear to be linear. However, increasing concentrations show nonlinear ...
Since microwaves are used in human cancer therapy, information on specific biological effects of microwaves at elevated temperatures is important. To help supply this information, we exposed mammalian cells (CHO) and bacteria (Serratia marcescens) to hyperthermal temperatures (43, 44, and 45/sup o/C for CHO and 48, 49, and 50/sup o/C for the bacteria) with and without microwave irradiation. Temperature control was maintained by a refrigeration-reheat system and high-velocity water recirculation. The 2450-MHz microwave source was operated in a pulsed mode with power density up to 500 mW/cm/sup 2/. As expected, the survival curve slopes for both cell types increased rapidly with temperature, doubling for each degree Celsius. Microwave irradiation produced no significant change in extrapolation number for either cell type. However, survival curves of CHO cells which received microwaves were steeper by a factor of 1.25 than their sham-irradiated controls. No significant effect on slope was ...
Modification of DNA and double-stranded deoxyoligonucleotides with antitumor 1,2-diamino-cyclohexanedinitroplatinum(II) (Pt-dach) complexes was investigated with the aid of physico-chemical methods and chemical probes of nucleic acid conformation. The three Pt-dach complexes were used which differed in isomeric forms of the dach non-leaving ligand-Pt(1R,2R-dach), Pt(1S,2S-dach) and Pt(1R,2S-dach) complexes. The latter complex has lower antitumor activity than the other two Pt-dach complexes. Pt(1R,2S-dach) complex exhibits the slowest kinetics of its binding to DNA and of the conversion of monofunctional binding to bifunctional lesions. The anomalously slow electrophoretic mobility of multimers of the platinated and ligated oligomers suggests that bifunctional binding of Pt-dach complexes to a d(GG) site within double-stranded oligonucleotides induces bending of the oligomer. It is proposed that different effects of the ...
Specific objectives were to: (1) develop and refine a methodology that can be used to evaluate the feasibility of MAG-LEV trains; (2) apply this methodology to the state of Oklahoma. The methodology is based on an aggregate econometric demand model and mathematical programming. A city-pair network is constructed to evaluate alternative MAG-LEV routes between Oklahoma City and nine other cites in and out of the state of Oklahoma. Results obtained from the aggregate econometric demand model indicates that MAG-LEV trains would attract significant ridership along different types of origin-destination routes. All nine corridors exhibit induced demand for MAG-LEV trains as well as attracting riderships from other modes. Based on the results of both single and multiobjective LP models, fixed-capital-cost requirements and annual operating cost for each of the above corridors are estimated, and by using different scenarios for ...
In light beams with circular or elliptic polarization, the transverse energy flow consists of the "spin" and "orbital" parts. Both of them can induce the orbital motion of microparticles suspended within the field of a light beam, and this should be taken into account in experiments on the spin-to-orbital angular momentum conversion. The character of the spin, orbital and total transverse energy flows in circular Laguerre-Gaussian beams is studied analytically; graphical representations of the flows in the beam cross section (flow maps) are calculated and analyzed. The spin circulatory flow can be directed oppositely to the orbital one and/or to the polarization handedness. As a result, the total transverse energy circulation of a beam with homogeneous circular polarization can be of different handedness in different regions of the beam cross section, which are separated by the contours of zero transverse energy flow. ...
There is a lot of interest in the studies that would help to understand whether there is a casual association between cancer and various types of molecular or cytogenetic damage detected in human cells. One major oncogenesis process is activation of proto-oncogenes by point mutations or chromosomal translocation. There are substantial evidence that indicates that the loss of heterozygosity of certain chromosomes is involved in human cancerogenesis. Our study aimed to elicit the possible association between cancer and DNA and cytogenetic abnormalities induced in lymphocytes of people bearing various categories of skin cancer cells. Fresh blood was collected by venipuncture from 25 individuals (including nine prior to cancer treatment). All patients were nonsmoking males, however 42.3 % of them were former smokers. Blood samples were divided into two parts and in the first part of samples cytogenetic studies were performed immediately, while from the second part ...
We investigate the evolution of Type Ib/c supernova (SN Ib/c) progenitors in close binary systems, using new evolutionary models that include the effects of rotation, with initial masses of 12-25 M_s_u_n for the primary components, and of single helium stars with initial masses of 2.8-20 M_s_u_n. We find that, despite the impact of tidal interaction on the rotation of primary stars, the amount of angular momentum retained in the core at the presupernova stage in different binary model sequences converges to a value similar to those found in previous single star models. This amount is large enough to produce millisecond pulsars, but too small to produce magnetars or long gamma-ray bursts. We employ the most up-to-date estimate for the Wolf-Rayet mass-loss rate, and its implications for SN Ib/c progenitors are discussed in detail. In terms of stellar structure, SN Ib/c progenitors in binary systems at solar metallicity are predicted to have a wide range of final ...
Mass accretion onto (proto-)stars at high accretion rates M-dot_*> 10"-"4 M_s_u_n yr"-"1 is expected in massive star formation. We study the evolution of massive protostars at such high rates by numerically solving the stellar structure equations. In this paper, we examine the evolution via disk accretion. We consider a limiting case of 'cold' disk accretion, whereby most of the stellar photosphere can radiate freely with negligible backwarming from the accretion flow, and the accreting material settles onto the star with the same specific entropy as the photosphere. We compare our results to the calculated evolution via spherically symmetric accretion, the opposite limit, whereby the material accreting onto the star contains the entropy produced in the accretion shock front. We examine how different accretion geometries affect the evolution of massive protostars. For cold disk accretion at 10"-"3 M_s_u_n yr"-"1, the radius of a protostar is initially small, ...
In order to demonstrate possible specific effects of microwaves at the cellular level V-79 Chinese hamster cells were exposed to 2.45-GHz radiation at power levels of 20-200 mW/cm2 and at specific absorption rates of 10-100 mW/g. Intracellular cytoplasmic changes were observed by fluorescence polarization using a method based on the intracellular enzymatic hydrolysis of nonfluorescent fluorescein diacetate (FDA). At levels of absorbed energy below 90 J/g, modifications of microviscosity and mitochondrial state were absent, but a slight stimulation of enzymatic hydrolysis of FDA was observed which may be explained by microwave-induced alterations of cellular membranes possibly due to differences in heating pattern of microwaves compared to water-bath heating. At levels of absorbed energy above 90 J/g, the decrease of enzymatic hydrolysis of FDA, increase in degree of polarization, and increase of permeation of the fluorescent marker correlated ...
Peroxisome proliferating agents (PPAs) are a structurally diverse group of chemicals that include environmental chemical contaminants such as certain chlorinated herbicides, solvents and plasticizers. PPAs have previously been shown to induce anti-trout laruci acid hydroxylase immunoreactive proteins in bluegill and catfish. In this investigation, induction of lauric acid hydroxylase activity and immunoreactive proteins was confirmed, and the mass spectral analysis of specific hydroxylation products was performed in order to identify possible species-specific differences in fatty acid metabolism. Male bluegill (Lepomis macrochirus) and channel catfish (Ictalurus punctatus) were administered clofibrate or ciprofibrate 48 hr prior to hepatic or trunk kidney (catfish only) microsome preparation. While no significant differences were observed in male catfish, male bluegill had significant decreases in hematocrit and plasma ...
This thesis is concerned with the crystallisation behaviour of polymers near to a free surface or a buried interface. The properties of polymers are expected to differ significantly near to an interface (either with air or another polymer), due to the contributions of (a) chain configurations induced at the interface, and (b) different mobilities between interfacial regions and the bulk of the sample. For a semi-crystalline polymer, properties such as the degree of crystallinity and the crystallisation kinetics may be enhanced near to a free surface. Grazing incidence x--ray diffraction (GIXD) is used to investigate such effects in poly(ethylene terphthalate) (PET), showing that a lower crystallisation temperature is obtained at the surface, and the crystallisation kinetics are faster at the surface for all temperatures. It is proposed that in thin films of PET, this surface-induced ordering provides ...
This study is aimed at exploring the possible mechanism of hypnosis-enhancing effect of HgS or cinnabar (a traditional Chinese medicine containing more than 95% HgS) in mice treated with pentobarbital. We also examined whether the effect of HgS is different from that of the well-known methyl mercury (MeHg). After a short period (7 days) of oral administration to mice, a nontoxic dose (0.1 g/kg) of HgS not only significantly enhanced pentobarbital-induced hypnosis but also attenuated tolerance induction; while a higher dose (1 g/kg) of HgS or cinnabar exerted an almost irreversible enhancing effect on pentobarbital-hypnosis similar to that of MeHg (2 mg/kg) tested, which was still effective even after 10 or 35 days cessation of administration. To study comparatively the effects of different mercury forms from oral administration of MeHg and HgS on membrane ATPase activities of experimental mice, analysis of the Hg content in ...
The effect of aerosol on clouds poses one of the largest uncertainties in estimating the anthropogenic contribution to climate change. Small human-induced perturbations to cloud characteristics via aerosol pathways can create a change in the top-of-atmosphere radiative forcing of hundreds of Wm-2. Here we focus on links between aerosol and deep convective clouds of the Atlantic and Pacific Intertropical Convergence Zones, noting that the aerosol environment in each region is entirely different. The tops of these vertically developed clouds consisting of mostly ice can reach high levels of the atmosphere, overshooting the lower stratosphere and reaching altitudes greater than 16 km. We show a link between aerosol, clouds and the free atmosphere wind profile that can change the magnitude and sign of the overall climate radiative forcing. We find that increased aerosol loading is associated with taller cloud towers and anvils. The taller clouds ...
BackgroundIsoproterenol-induced cardiac hypertrophy in mice has been used in a number of studies to model human cardiac disease. In this study, we compared the transcriptional response...Full Text Available
Studies fail to find uniform effects of age-related or induced hypogonadism on human sexual function. We examined the effects of induced hypogonadism on sexual function in healthy men and women...Full Text Available
The author derives to which of the three types an irreducible UA representation which is obtained with the procedure of generalised induction belongs. The question whether or not the irreducible induced UA representations are on standardform is analysed. The results hold as well for induced PUA representations. (Auth.).
Many patients are currently suffering from nickel (Ni)-induced allergic contact dermatitis (ACD). There have been few Korean studies dealing with the threshold of Ni-induced ACD and quantifying the...Full Text Available
We introduce cyclophosphamide-induced alopecia (CYP-IA) in C57BL-6 mice as a clinically relevant model for studying the biology of chemotherapy-induced alopecia and for developing anti-alopecia drugs....Full Text Available
The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both...Full Text Available
Design and procurement of equipment for nuclear power plant took place in late 1970's. A large number of originally installed equipment is obsolete. The manufacturer's do not support their products or have discontinued their production due to technological evolutions or lack of product demand. Lack of spares affects the performance of obsolete equipment and has a negative impact on plant safety and plant production. A proactive approach to address obsolescence is necessary to ensure critical spares are always available when needed. This is an ongoing effort and requires a program to be in place to resolve immediate and longterm issues. A cross-functional team with adequate external exposure is needed to administer the obsolescence program. CANDU utilities and CANDU Owners Group(COG) has taken initiatives to identify lack of equipment spares in the members' plant. The equipment replacement information collected from each ...
Several organophosphate and organochlorine compounds, including pesticides commonly found in the Great Lakes basin, have the potential to induce immunotoxicity. Because of biomagnification and accumulation...Full Text Available
Neutron-induced soft error rates (SER`s) of subhalf-micron CMOS SRAM and Latch circuits were studied both experimentally and analytically to investigate cosmic ray neutron-induced soft errors (SE`s). Because the neutron beam used in the measurement has an energy spectrum similar to that of sea-level atmospheric neutrons, the SER data corresponds to those induced by cosmic ray neutrons. The {alpha}-particle induced SER`s were also measured for comparison with the neutron-induced SER`s. Neutron-induced SE`s occurred in both circuits. On the other hand, {alpha}-induced SE`s occurred in SRAM, but not in the Latch circuit. The measured SER`s agreed with simulated results. The authors discussed the significance of how cosmic ray neutrons affects CMOS circuits at ground level.
In rats, drug-induced depression of the central nervous system has been shown generally to be associated with an elevation in level of total acetylcholine in the brain. This generalization held true...Full Text Available
Full text: The IRSN has been organizing enquiries with the French population about risk and risk perception for a long time. In 2002, a collaboration between the IRSN in France and the SCK.CEN in Belgium has been set-up to simultaneously (November 2002) organise this poll in both countries. In each country, a representative sample of the population (over 1000 participants per country) has been consulted by Computer Aided Personal Interviews of about 30 minutes with the professional help of commercial companies: BVA in France and Research International in Belgium. The enquiry yields a broad spectrum of interesting data; here only the results relevant for the emergency context will be presented. One should be aware that these data were collected in a 'normal' period; important differences in behaviour may occur given a serious crisis. A first finding is that more than half of the respondents are convinced that an accident as severe as the Chernobyl disaster may ...
This article examines relevant government policy documents on education and culture and discovers that Nigerian education authorities do not "discriminate" against art and culture in its articulation of educational policies per se, but lack of administrative machinery or political will has resulted in the deprivation of the Nigerian child in the process of creative activity in early childhood development. The article argues that lack of creative ability in our educational products is perhaps a major setback in the nation's quest for industrial and technological development. In this article a new art curriculum for elementary schools is advocated as a means of engaging the young child in order to attain functional educational skills necessary in the world of work.
Recycling of carbon by the photorespiratory pathway involves enzymatic steps in the chloroplast, mitochondria, and peroxisomes. Most of these reactions are essential for plants growing under ambient CO2 concentrations. However, some disruptions of photorespiratory metabolism cause subtle phenotypes in plants grown in air. For example, Arabidopsis thaliana lacking both of the peroxisomal malate dehydrogenase genes (pmdh1pmdh2) or hydroxypyruvate reductase (hpr1) are viable in air and have rates of photosynthesis only slightly lower than wild-type plants. To investigate how disruption of the peroxisomal reduction of hydroxypyruvate to glycerate influences photorespiratory carbon metabolism we analyzed leaf gas exchange in A. thaliana plants lacking peroxisomal HPR1 expression. In addition, b...
SummaryThis paper evaluates the status of digitization in 30 Nigerian university libraries with a view to identifying the status, progress, prospects and challenges to digitize library materials and form the basis of providing a roadmap to successful execution of digitization projects. The study assessed the status of digitization of past question papers, theses and dissertations in Nigerian university libraries from May to September 2006 through a self-administered questionnaire, site visits and interviews. It was found that, though there are automation services in those universities, there is no digitization of these materials mentioned in the surveyed institutions. The major obstacles militating against digitizing in the university libraries include lack of funds, lack of appropriate fa...
Summary A prospective and randomized trial design is of utmost interest when it comes to evaluating new developments in the management of cardiovascular medicine. By defining the primary end point and a profound related statistic new therapeutic options can be tested with an adequate number of patients. The course of the trial is supervised by a Clinical Events Committee and a Data and Safety Monitoring Board. Registries are promising tools for describing how the results of clinical trials are translated into daily practice. Their drawbacks include lack of control of the clinical endpoints and their uniform definition and lack of a control group. There are numerous examples from cardiology of the limited usefulness of data obtained from registry studies with their often unexpected results ...
BACKGROUND: Calibration by inverse modelling was performed with the MACRO transport and fate model using long-term (>10 years) drainflow and isoproturon (IPU) data from western France. Two lack-of-fit (LOF) indices were used to control the inverse modelling: sum of squares (SS) and an alternative statistic called the vertical-horizontal distance integrator (VHDI), which is designed to account for offsets in observed and predicted arrival times of peak IPU concentration. With these data, SS was artificially inflated because it is limited to comparison of predicted and observed IPU concentrations that are concurrent in time. The LOFs were used along with the index of agreement (d) and the correlation coefficient (r) to ascertain the fit of the calibrated models. RESULTS: Predicted arrival ti...
In laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), the properties of laser-generated aerosols, such as size and composition, are crucial for matrix-independent quantification. In this study, the aerosol particle morphology and elemental composition generated by two state-of-the-art laser systems (ArF excimer nanosecond-UV laser and Ti:sapphire femtosecond-IR laser) were investigated by electron microscopic techniques. Electrostatic sampling of the aerosols directly onto transmission electron microscopy (TEM) grids allowed us to study the morphology and elemental composition of the aerosols using TEM and TEM-EDX (energy dispersive X-ray spectroscopy) analyses, respectively. The results of the electron microscopic studies were finally compared to the LA-ICPMS signals of the main matrix components. The investigations were carried out for non-conducting materials (glass and zircon), metallic samples (steel and brass) and semiconductors (sulfides). The studies ...
Four techniques for using LIDAR in Search and Rescue Operations will be discussed. The topic will include laser retroreflection, laser-induced fluorescence in the visible, laser-induced fluorescence during daylight hours, and laser-induced fluorescence in the uv. These techniques use high-repetition rate lasers at a variety of frequencies to induce either fluorescence in dye markers or retroreflection from plastic corner cubes on life preservers and other emergency markers.
Stem-boring insects and methyl jasmonate (MeJA) are thought to induce similar complex chemical and anatomical defenses in conifers. To compare insect- and MeJA-induced terpenoid responses, we analyzed...Full Text Available
Hyperosmotic stress is known to significantly enhance net uptake of inorganic ions into plant cells. Direct evidence for cell turgor recovery via such a mechanism, however, is still lacking. In the...Full Text Available
Background. New-generation drug-eluting stents (DES) may solve several problems encountered with first-generation DES, but there is a lack of prospective head-to-head comparisons between...Full Text Available
DescriptionAbstract of Research Proposal The root environment has a major effect on crop growth, both directly through the supply of water and nutrients to the shoot, and indirectly through root to shoot signalling. Better management of crop root systems through agronomic and genetic means has the potential to improve the efficiency of water and nutrient uptake, and limit root restrictions to crop growth. However, progress in this area is currently limited by the lack of sensors for in situ estimates of [continued...
Escherichia coli rnh mutants lacking RNase H activity are capable of recA+-dependent DNA replication in the absence of concomitant protein synthesis (stable DNA replication). In rnh dnaA::Tn10 and rnh...Full Text Available
Vietnam is beginning its industrialization process, and it currently lacks the capital necessary for expensive pollution control and treatment systems. Pollution strategies are critical for the country. This study evaluates the present status of industry and the pollution problems associated with industrial development in Vietnam. The purpose of the study is to identify sectors that may have potential for promoting cleaner production practices. 4 refs.
Two patients receiving maintenance dialysis therapy developed osteonecrosis, the first in the humeral head and the second in the talus. Both patients lacked known risk factors for developing osteonecrosis. A possible pathogenic role of secondary hyperparathyroidism in this disorder is suggested. Rheumatologists evaluating patients receiving maintenance dialysis with rheumatic manifestations should be aware of this potential complication. PMID:2185360
Seventeen clinical isolates of Staphylococcus aureus (from the United States and Europe) selected for low (borderline)-level methicillin resistance (MIC of methicillin, 2 to 4 micrograms/ml; MIC of...Full Text Available
The long pentraxin PTX3 has multiple roles in innate immunity. For example, PTX3 regulates C1q binding to pathogens and dead cells and regulates their uptake by phagocytes. It also inhibits P-selectin-mediated...Full Text Available
The industrial solvent trichloroethylene (TCE) and its major metabolites have been shown to cause formic aciduria in male rats. We have examined whether chloral hydrate (CH) and trichloroacetic...Full Text Available
Mice lacking Kv1.1 Shaker-like potassium channels encoded by the Kcna1 gene exhibit severe seizures and die prematurely. The channel is widely expressed in...Full Text Available
This paper very briefly outlines hazardous waste management issues, including regulations, in Mongolia. Air, water, and soil pollutants are identified and placed in context with climatic, social, and economic circumstances. The primary need identified is technology for the collection and disposal of solid wastes. Municipal waste problems include rapid urbanization and lack of sanitary landfills. Industrial wastes of concern are identified from the mining and leather industries. 4 refs., 2 tabs.
Most algorithms for three-dimensional (3D) reconstruction from electron micrographs assume that images correspond to projections of the 3D structure. This approximation limits the attainable resolution of the reconstruction when the dimensions of the structure exceed the depth of field of the microscope. We have developed two methods to calculate a reconstruction that corrects for the depth of field. Either method applied to synthetic data representing a large virus yields a higher resolution reconstruction than a method lacking this correction.
BackgroundNatural disasters result in significant numbers of disabling impairments. Paradoxically, however, the traditional health system response to natural disasters largely neglects health-related rehabilitation as a strategic intervention.ObjectivesTo examine the role of health-related rehabilitation in natural disaster relief along three lines of inquiry: (1) epidemiology of injury and disability, (2) impact on health and rehabilitation systems, and (3) the assessment and measurement of disability.DesignQualitative literature review and secondary data analysis.ResultsAbsolute numbers of injuries as well as injury to death ratios in natural disasters have increased significantly over the last 40 years. Major impairments requiring health-related rehabilitation include amputations, traumatic brain injuries, spinal cord injuries (SCI), and long bone fractures. Studies show that persons with pre-existing disabilities are more likely to die in a natural disaster. ...
The Sacramento Municipal Utility District is developing a number of demonstration projects using geothermal heat pumps. This paper discusses some of the barriers and issues that have emerged over the past two years. The most important barriers are: regulatory impediments; high first cost; and a lack of local design and installation infrastructure.
Identity is a part of self-consciousness, which is also expressed as ''being in the world'' which one in turn shows to others as the Self. The assessment of the Self in a population of patients with Alzheimer's disease, according to a multidimensional definition (physical, social, spiritual), showed that the social self was impaired, and the severity of impairment of the self was correlated to apathy and lack of semantic autobiographical memory. It also appears that ipseity is selectively affected by the disease.
Cytomegalovirus (CMV)-seropositive patients with ESRD may have more CD4+ T cells lacking the co-stimulatory molecule CD28 (CD4+CD28null) than CMV-seronegative patients. Increased...Full Text Available
The authors review two types of simulators for the analysis of cosmic ray neutron-induced soft errors (SE's). One of them is the neutron-induced soft error simulator (NISES). A recently proposed nuclear reaction theory forms the foundation for the nuclear reaction database used in NISES. The other simulator, the simplified simulator MBGR, is based on a modified version of the burst generation rate (BGR) model. Both simulators accurately simulate neutron-induced SE rates (SER's). MBGR actually provides an easier and quicker estimation of neutron-induced SER's than NISES. On the other hand, NISES covers more applications; it simulates neutron-induced charge collection, multiple-bit SE, and [alpha]-induced SE analysis.
The authors review two types of simulators for the analysis of cosmic ray neutron-induced soft errors (SE's). One of them is the neutron-induced soft error simulator (NISES). A recently proposed nuclear reaction theory forms the foundation for the nuclear reaction database used in NISES. The other simulator, the simplified simulator MBGR, is based on a modified version of the burst generation rate (BGR) model. Both simulators accurately simulate neutron-induced SE rates (SER's). MBGR actually provides an easier and quicker estimation of neutron-induced SER's than NISES. On the other hand, NISES covers more applications; it simulates neutron-induced charge collection, multiple-bit SE, and #alpha#-induced SE analysis
A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) and phosgene (COCl/sub 2/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation toxicity studies. The effect of 4-h exposures to ozone at concentrations of 0.2, 0.5, 1.0, and 2.0 ppm, and to COCl/sub 2/ and 0.1, 0.2, 0.5, and 1.0 ppm was determined in rabbits, guinea pigs, rats, hamsters, and mice. Lavage fluid protein (LFP) accumulation 18-20 h after exposure was used as the indicator of O3- and COCl/sub 2/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 mg/ml) when a volume of saline that approximated the total lung capacity was used to lavage the collapsed lungs. Ozone effects were most marked in guinea pigs, which showed significant effects at 0.2 ppm and above. Mice, hamsters, and rats showed effects at 1.0 ppm O3 and above, while rabbits responded ...
The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios. The measured relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios were compared to the calculated values predicted by the theoretical development of ...
The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios. The measured relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios were compared to the calculated values predicted by the theoretical development of Scofield and ...
Mechanisms and associated energetics for adatom diffusion on the (100) and (110) surfaces of Ni, Cu, Rh, Pd, and Ag are investigated. Self-diffusion was studied on (100) and (I 10) surfaces of Ni, Cu, Pd and Ag using corrected effective medium method (CEM) and approximation to CEM used for molecular dynamics and Monte Carlo studies (MD/MC-CEM). Self-diffusion on Pd(100), Ag(100), Ni(110), Cu(110), Pd(110), and Ag(110) is accomplished by classical diffusion: the adatom hops from its equilibrium adsorption site over an intervening bridge site to an adjacent equilibrium site. Self-diffusion on Ni(100) and Cu(100) proceeds by atomic-exchange diffusion: the adatom on the surface displaces an atom in the first surface layer. Aside from explicit inclusion of the kinetic-exchange-correlation energy, it is critical to include enough movable atoms in the calculation to insure correct energetics. Distortions induced by these diffusion mechanisms, especially atomic exchange, ...
The aim of this work was to develop a method to distinguish between different ion formation processes and to determine the influence of these processes on the total number of detected monatomic ions of a certain element. A vector/matrix-formalism was developed, which describes the physical processes of sputtering, ion formation, mass separation and detection in laser-SNMS. In the framework of the method developed, based on this theoretic formalism, changes in the secondary flux contribution of the respective element were observed by comparing the detected monatomic ion yield obtained in specifically aligned (SIMS and) laser-SNMS experiments. The yields resulting from these experiments were used to calculate characteristic numbers to compare the flux composition from different surfaces. The potential of the method was demonstrated for the elements boron, iron and gadolinium by investigating the changes in the flux composition of secondary ...
A quantitative comparison of tissue distribution and excretion of an orally administered sublethal dose of [3H]diacetoxyscirpenol (anguidine) was made in rats and mice 90 min, 24 hr, and 7 days after treatment. Total recoveries of 95-100% were obtained. Approximately 90% of the dose was excreted in urine and feces during the first 24 hr with a feces:urine ratio of about 1:4.5 in both species. Carcass and tissue radioactivity dropped rapidly during the first 24 hr but remained relatively constant at low, but detectable, levels over the course of the experiment. Few substantive interspecies differences were noted in tissue distribution. At 90 min the highest percentage of dose was in tissues involved in sequestering diacetoxyscirpenol because of high body water/lipid content or the absorption, metabolism, or excretion of the toxin. The rank order of these tissues was generally stable over the course of the experiment. When data were expressed as specific ...
The purpose of this research was to: a) evaluate variations in sensitivity and uniformity of SPECT detectors during 360"0 rotation, b) explore the causes of the variations and c) to discuss a correction procedure. A flood source consisting of a lucite disc 47.7 cm in diameter containing 3 microcuries of Co-57 was constructed. This source can be firmly attached to the uncollimated detector guaranteeing no detector-source geometry change during rotation. Four different SPECT cameras were tested. Measurements were obtained at 45"0 intervals throughout a 360"0 rotation, and repeated in 3 different orientations with respect to the earth's magnetic field. In one camera the effects of the direction and strength of induced magnetic fields were studied. All detectors showed cyclic rotational variations in sensitivity; in three cameras 6%, in one 3%. The amplitude and phase of the sensitivity variation curves and the variations in ...
The growing concern of the population with regards to the problem of atmospheric pollution has induced a change in the role of air quality monitoring networks, especially those monitoring air pollution in large cities which suffer from summer smog. The population is no longer satisfied with real-time measurements but wants to be warmed of high pollutants concentrations in advance. Some countries have been forecasting air pollution, and especially ozone, for a large number of years. Although most of them use statistical models based on the analyses of past conditions which induced high pollution episodes, some predict ozone levels using only their knowledge of the meteorological situation. Nowadays two trends appear regarding ozone forecasting: either very basic statistical methods, such as regression, or more sophisticated ones, such as neural networks. The paper then reviews several behaviours common to most forecasting models: the uncertainly ...
Coal is the most abundant available fossil fuel in Australia and provides a substantial part of energy needs. It is used for power generation, to supply energy to industry as well as for domestic requirements. Analysis of trace elements (the elements present in coal in ppm/ppb level) during combustion of coal in very important. Trace elements, like heavy metals such as arsenic, selenium, and chromium etc. are hazardous to the environment and some of them have carcinogenic potency. In the near future more stringent limits may be proposed for such elements generated from combustion process, such as coal combustion in power plants. Hence analysis and assessment of the emissions of these elements is essential at this stage. The first step towards reducing any impacts of trace elements is to have accurate quantitative analysis. Analysis of coal, bottom ash and fly ash collected from five different power stations across Australia was carried out to study the quantity and ...
On 21 October 1994, three brothers entered a waste repository at Tammiku, Estonia, without authorization and removed a metal container enclosing a caesium-137 source. During the removal the source was dislodged and fell to the ground. One of the men picked up the source, placed it in his pocket and took it to his home in the nearby village of Kiisa. Very soon after entry into the repository he began to feel ill, and few hours later he began to vomit. The man was subsequently admitted to hospital with severe injuries to his leg and hip and died on 2 November 1994. The injury and subsequent death were not attributed to radiation exposure, and the source remained in the man's house with his wife and stepson and the boy's great-grandmother. The boy was hospitalized on 17 November with severe burns on his hands, and these were identified by a doctor as radiation induced. The authorities were alerted, and the Estonian Rescue Board recovered the source from the house. The ...
In this study, we measured the effects of different concentrations of paraquat (0,01 mM and 1,0 mM) on the 1-"1"4CO_2 and 6-"1"4CO_2 production of rabbit lung slices and isolated alveolar macrophages, in 20% and 95% oxygen phases respectively. A 95% oxygen phase induced an increase in the 6-"1"4C-glucose oxidation of control lung slices over a 3-hour period, while the increased activity of the pentose pathway over the first 2 hours started to decline during the third hour of incubation. Paraquat (1,0mM) in 20% oxygen caused a consistent increase in the 6-"1"4CO_2 production by lung slices, but in a 95% oxygen phase gradually inhibited the 6-"1"4C-glucose oxidation over a period of 3 hours. The pentose phosphate pathway was highly significantly stimulated by 1,0 mM paraquat in 20% and 95% oxygen over 3 hours. When isolated alveolar macrophages (viability 95%) were incubated in a 20% and 95% oxygen phase respectively, both the 6-"1"4C-glucose and ...
The effect of exercise training prior to acute myocardial infarction (AMI) on left ventricular (LV) remodeling is poorly understood. This study investigated the protective effect of 3 weeks of swimming exercise training prior to AMI on cardiac morphology and function. Male Sprague-Dawley rats (n = 35) were randomly assigned to 3 groups: swimming training (n = 14, 90 min, 5 days/wk, 3 wk), sedentary (n =14), and controls (n = 7, no exercise, no MI). At the end of the training/sedentary period, rats were subjected to AMI (ExMI and SedMI) induced by surgical ligation of the left coronary artery. Thereafter, the rats remained sedentary for a 4-wk recovery period. Trans-thoracic echocardiography was performed in each group at the end of the exercise/sedentary period (pre-AMI), 24 hr after AMI, and following recovery (4 wk after AMI). No differences were observed in LV dimensions and function pre-AMI among the 3 groups; however, LV-end systolic ...
In support of the efforts to apply ceramics in advanced heat engines, a study was made of the sliding performance of ceramics at the ring/cylinder interface of low heat rejection engines. The objective was to understand the basic mechanisms controlling the wear of candidate ceramics and thereby identify means for applying these ceramics effectively. Attempts to operate three different zirconias, silicon carbide, silicon nitride, and several plasma-sprayed ceramic coatings without lubrication were unsuccessful because of high friction and high wear rates. Experiments using a polyalphaolefin lubricant at temperatures to 260 C identified several combinations having wear rates in the general range likely to be acceptable for engines. Plasma-sprayed coatings of chromium oxide and hypersonic powder flame sprayed coatings of cobalt-bonded tungsten carbide performed particularly well as ring coatings. Similar performance was obtained with these ring coatings operating ...
In this work the diffusion of ion-beam-injected self-interstitials (Is) and their interaction with impurities in crystalline Si are presented. In particular, the I penetration into a molecular beam epitaxy grown Si structure was studied by means of diffusion effects induced on B spikes, analyzed by a developed simulation code. Trapping effects at sample-surface and bulk are evidenced and modeled. The B marker approach was extended to the two-dimensional (2D) I-diffusion occurring as a consequence of ion implantation through a sub-micron dimension patterned oxide mask. I-source size effects on the I penetration have been found and modeled, quantitatively describing the 2D I-diffusion. The I-substitutional carbon interactions have been also studied, showing the C ability to effectively retain Is. The I-trapping mechanism was quantitatively studied by the simulation code, showing that one I is able to deactivate about two C traps by means of I-trapping and ...
In order to follow some of the changes induced by ultraviolet-B (UV-B, 280-320 nm) radiation in Phaseolus vulgaris and Brassica napus, experiments were designed to localize sites of changes in leaves and to correlate some of the physiological and biochemical changes with penetration of UV-B radiation. B.napus was exposed to 8.9 kJ m"-"2 day"-"1 biologically effective UV-B radiation (UV-B_B_E). The penetration of UV-B radiation into the leaf was followed using a quartz fibre optic microprobe. Monochromatic radiation at 310 nm was decreased by ca 50 and 34% in the adaxial and abaxial epidermis, respectively, in plants not exposed to UV-B, whereas the radiation was decreased by ca 70 and 42%, respectively, in the same region in UV-treated plants. Polychromatic radiation showed a wavelength dependent change mainly for the collimated radiation. The results correlated with the distribution of phenolic compounds analysed from 40 #mu#m paradermal leaf sections. The first ...
Retroviruses are well known pathogens of mammals, birds and fish. Their potential to induce cancer in chickens was already described almost 100 years ago and murine retroviruses have been a subject of study for 50 years. The first human retroviruses, HTLV and HIV, were discovered more than 30 years ago, surprising researchers and physicians by the profound differences in the diseases they cause. HTLV-1 is able to induce, after decades of infection, lymphomas/leukemia or neuroimmune disorders whereas untreated HIV infection leads almost inevitably to AIDS. The recently described XMRV (xenotropic murine leukemia virus-related virus) appeared to possess many of the features known for HTLV and was regarded by some to be the third human retrovirus. However, recent publications by Knox et al. [1] and Paprotka et al. [2] have shed new light on this gammaretrovirus. Knox and colleagues clearly demonstrate that XMRV is absent in ...
Cinnabar, a naturally occurring mercuric sulfide (HgS), has long been used in combination with traditional Chinese medicine as a sedative for more than 2000 years. Up to date, its pharmacological and toxicological effects are still unclear, especially in clinical low-dose and long-term use. In this study, we attempted to elucidate the effects of cinnabar on the time course of changes in locomotor activities, pentobarbital-induced sleeping time, motor equilibrium performance and neurobiochemical activities in mice during 3- to 11-week administration at a clinical dose of 10 mg/kg/day. The results showed that cinnabar was significantly absorbed by gastrointestinal (G-I) tract and transported to brain tissues. The spontaneous locomotor activities of male mice but not female mice were preferentially suppressed. Moreover, frequencies of jump and stereotype-1 episodes were progressively decreased after 3-week oral administration in male and female mice. ...
Production of porous membranes using heavy ion bombardment and subsequent chemical etching of poly(vinylidene difluoride) (PVDF) films has been reported several years ago. However, porous membranes with pore diameter in the nanometer scale requires a better understanding of the chemical etching mechanism. In this work PVDF foils irradiated with Sn ions (2.85 MeV per nucleon) were exposed to several etching conditions which involved permanganate oxidation in different alkaline environments. The solution of KOH 9 mol L{sup -1} and saturated in KMnO{sub 4} was the best etching reactant for PVDF. Functional groups created in the alkaline and oxidative attack by permanganate were studied by FT-IR and UV-vis spectroscopy. The spectroscopic data reveals that the formation of pores occurs by a two-step mechanism: (i) double bonds as a result of dehydrofluorination induced by alkaline media and (ii) oxidation of these double bonds in permanganate ...
Paraquat (1,1'-dimethyl-4,4'-bipyridinium) is a widely used herbicide known to induce skin toxicity. This is thought to be due to oxidative stress resulting from the generation of cytotoxic reactive oxygen intermediates (ROI) during paraquat redox cycling. The skin contains a diverse array of antioxidant enzymes which protect against oxidative stress including superoxide dismutase (SOD), catalase, glutathione peroxidase-1 (GPx-1), heme oxygenase-1 (HO-1), metallothionein-2 (MT-2), and glutathione-S-transferases (GST). In the present studies we compared paraquat redox cycling in primary cultures of undifferentiated and differentiated mouse keratinocytes and determined if this was associated with oxidative stress and altered expression of antioxidant enzymes. We found that paraquat readily undergoes redox cycling in both undifferentiated and differentiated keratinocytes, generating superoxide anion and hydrogen peroxide as well as increased protein oxidation which ...
Purpose: The aim of this study was to create, perfect and test a hyperthermia balloon catheter for local treatment of cholangiocarcinoma. The device should induce hyperthermia in tumor tissue by acting locally in the bile duct lumen in contact with the tumor-infiltrated duct wall. In addition, it should exert tissue compression to cause an appreciable reduction in tumor microvasculature flow, thus improving thermal performance. Methods: According to the design specifications, the working temperature range should allow the device to be used for hyperthermia therapy either in combination with radiation and/or chemotherapy(radio/chemo-sensitizing effect at 42-45 deg. C) or alone (induction of coagulation necrosis above 65 deg. C). The balloon serves as an anchoring system during treatment and as a functional element to induce tissue compression. In vitro mechanical evaluation of the pressure/volume relationship, with the balloon inside rigid ...
The purpose of this study was to correlate MR imaging findings with pathology in experimental hyperoxia-induced acute lung injury, which has similar pathology to diffuse alveolar damage (DAD). Seventeen Yorkshire pigs were studied. These animals were exposed to more than 80% oxygen for 24, 48, 72, and 96 hours in a sealed cage. The lungs were removed and inflated with air infused through the trachea, and then examined by both MRI and high-resolution CT (HRCT). T1-weighted spin-echo (T1WSE), T2-weighted fast (T2WFSE), and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences were performed. Severity in MR findings and signal-to-noise ratios (SNR) on MR images were well correlated with pathological scores. CT values were also correlated well with pathologic scores. Abnormal SNR values were obtained from a pathological score of 5, whereas abnormal CT values were obtained from a pathological score of 15. Furthermore, significant ...
X-ray magnetic circular dichroism (XMCD) was used to probe the existence of induced magnetic moments in yttrium iron garnet (YIG) films in which yttrium is partly substituted with lanthanum, lutetium or bismuth. Spin polarization of the 4d states of yttrium and of the 5d states of lanthanum or lutetium was clearly demonstrated. Angular momentum resolved d-DOS of yttrium and lanthanun was shown to be split by the crystal field, the two resolved substructures having opposite magnetic polarization. The existence of a weak orbital moment involving the 6p states of bismuth was definitely established with the detection of a small XMCD signal at the Bi M{sub 1}-edge. Difference spectra also enhanced the visibility of subtle changes in the Fe K-edge XMCD spectra of YIG and {l_brace}Y, Bi{r_brace}IG films. Weak natural X-ray linear dichroism signatures were systematically observed with all iron garnet films and with a bulk YIG single crystal cut ...
Zircaloy-2 and Zircaloy-4 tubing materials were irradiated with 1 MeV proton at 350 degrees C to doses of 0.01, 0.1, and 1 dpa respectively. Both microstructure examination and nodular corrosion test (500 degrees C, 1500 psi steam) were performed in order to understand the relationship between the microstructural evolution and the corrosion resistance of these alloys under irradiation. Neutron-irradiated Zircaloy-2 specimens which were obtained from a failed BWR fuel rod cladding were also studied. Specimens of three different neutron fluences were investigated; namely, 2.6x10"2"4, 3.2x10"2"5, 3.8x10"2"5, (E_n#>=#1MeV). The results indicated that the higher the irradiation dose the better the nodular corrosion resistance of both Zircaloy-2 and Zircaloy-4. It is concluded that irradiation-induced precipitate dissolution and irradiation-enhanced diffusion may increase the solute concentration in the matrix and make it distributed more evenly ...
Some magnetron sputtering systems experience rapid oscillations in the current and voltage of the plasma discharge after several hours when equipped with certain targets. These oscillations often lead to the plasma becoming extinguished, a condition known as ''flame-out.'' This article details the study of two 90% W--10% Ti magnetron targets which differed in density. The higher density targets sometimes experienced flame-out after approximately 3 h of sputtering. The less dense material could be sputtered for the entire 15 h life of the target. Scanning electron microscopy pictures and atomic composition depth profiles were obtained using Auger electron spectroscopy. In addition, a Colutron-based ion source with a high vacuum system was used to measure ion-induced secondary electron emission coefficients as a function of energy, ion specie, and gas coverage. Analysis of the sample from the group that suffers flame-out showed large regions of ...
Previous in vitro studies have demonstrated that Ho:YLF laser is capable of inducing physical and chemical changes on dental surfaces treated for caries prevention. The temperature in the pulp chamber was in vitro evaluated to as a function of the power and frequency of the laser irradiation. The purpose of this work is to verify the occurrence of pulp inflammation after Ho:YLF laser irradiation using different parameters in rabbits' teeth. The premolars and molars of ten rabbits (NZB) were divided in two groups according to the irradiation energy values of a Ho:YLF laser prototype operating at 2.065{mu}m wave length, frequency of O,5Hz and pulse length of 250{mu}s. An group A teeth were irradiated with using ten pulses of 334mJ/pulse of a Ho:YLF laser prototype operating at O.5Hz, and group B, with 512mJ/pulse. Animals were killed by transcardiac perfusion and the samples were prepared for histopathological analysis. The in vitro ...
The present study was designed to assess the radioprotective effects of amifostine on ovarian follicles. Three week-old female mice with or without pretreatment of amifostine were irradiated with 6.42 Gy of #gamma# -ray. Ovaries were collected 0 and 6h after irradiation. DNA fragmentation pattern and expression of genes and activity of proteins related with apoptosis were investigated by means of RT-PCR and Western blot. Proliferation of granulosa cells was reduced and incidence rate of follicular atresia was increased in ovarian follicles in #gamma# -ray irradiated mice compared to those in control or amifostine-treated group. DNA fragmentation was increased in time-dependent manner in granulosa cells of all irradiated groups. However, no difference between amifostine pre-treated group and irradiated groups was found and the expression of p53 as tumor suppressor gene and Bax as one of pro-apoptotic Bcl-2 family was increased in irradiated mice ovaries. PARP as DNA ...
This work covers three distinct aspects of deformation and fracture during indentations. In particular, we develop an approach to verification of nanoindentation induced film fracture in hard film/soft substrate systems; we examine the ability to perform these experiments in harsh environments; we investigate the methods by which the resulting deformation from indentation can be quantified and correlated to computational simulations, and we examine the onset of plasticity during indentation testing. First, nanoindentation was utilized to induce fracture of brittle thin oxide films on compliant substrates. During the indentation, a load is applied and the penetration depth is continuously measured. A sudden discontinuity, indicative of film fracture, was observed upon the loading portion of the load-depth curve. The mechanical properties of thermally grown oxide films on various substrates were calculated using two different ...
The DNA double-strand break (DSB) damage response induced by high energy charged particles on lung fibroblast cells embedded in a 3-dimensional (3-D) collagen tissue equivalents was investigated using antibodies to the DNA damage response proteins gamma-histone 2AX (#gamma#-H2AX) and phosphorylated DNA-PKcs (p-DNA-PKcs). 3-D tissue equivalents were irradiated in positions across the linear distribution of the Bragg curve profiles of 307.7 MeV/nucleon, 556.9 MeV/nucleon, or 967.0 MeV/nucleon "5"6Fe ions at a dose of 0.30 Gy. Patterns of discrete DNA damage streaks across nuclei or saturated nuclear damage were observed, with saturated nuclear damage being more predominant as samples were positioned closer to the physical Bragg peak. Quantification of the DNA damage signal intensities at each distance for each of the examined energies revealed a biological Bragg curve profile with a pattern of DNA damage intensity similar to the physical Bragg curve for the ...
Water repellency en the microstructure super-hydrophobic cured surface is important for research and industrial purposes. This microstructure film can be cured on polyethylene terephthalate PET surface by electron beam (EB) at different irradiation doses 10-100 kGy. The microstructure formulation composed from hydrophobic acrylate oligomer (EB 244) and monomer (SR 440). The irradiation induced cross linking of the prepared microstructure was proved by FTIR spectroscopy and the adhesion force by abrasion test. Some factors affecting the adhesion force of the prepared microstructure film such as oligomer/monomer composition ratio and the thickness of the microstructure cured film were studied. The contact angles (8) were measured on cured surfaces before and after adding the super hydrophobic nanoparticles (Zonyl 9361). The super-hydrophobic cured surface showed the self-cleaning property. The volume of water droplet affected both the observed ...
Anticancer drug thyotepa (10 mg/ kg) hormonal compound thyroxine (40 mg / kg) and D3 vitamin (30,000 IU / kg) have been administrated simply or associated to Wistar rats bearing Walker carcinosarcoma. The chromatin (the complex of DNA and proteins from nuclei) has been extracted from Walker tumor and submitted to fast neutron beams produced by deuterons (13 MeV) on thick Be target at an IPNE U-120 Cyclotron, in doses of 5-100 Gy. Thermal transition of chromatin fluorescence intensity of chromatin-ethidium bromide complexes and intrinsic fluorescence of chromatin have been analysed. Association of thiotepa with thyroxine and D3 vitamin produced a diminution of chromatin lesions induced by the cytostatic. Thus in the effects of fast neutrons radiolysis in chromatin significant differences occurred. These results could help to improve the methodology of associated chemotherapy-radiotherapy in clinical applications. (author).
Eight patients who had received megavoltage therapy for Cushings' disease 5-12 years previously have been reviewed. The long term response to this therapy was assessed with respect to efficacy of treatment in inducing continued remission and disturbance of hypothalamic-pituitary function. One patient showed clear evidence of relapse of Cushings' disease. One patient had unequivocal hypopituitarism. Basal levels of growth hormone (GH), TSH, LH, and FSH were not statistically different from controls, but provocative testing revealed significant abnormalities of response of cortisol/ACTH, GH, prolactin and LH. Six out of eight patients had absent diurnal cortisol variation and five patients had elevated serum prolactin levels. Thus, in this group of patients normal pituitary-adrenal function has not been satisfactorily restored. It is clear that significant disturbances of hypothalamic-pituitary function follow megavoltage therapy and these may ...
Eight patients who had received megavoltage therapy for Cushings' disease 5-12 years previously have been reviewed. The long term response to this therapy was assessed with respect to efficacy of treatment in inducing continued remission and disturbance of hypothalamic-pituitary function. One patient showed clear evidence of relapse of Cushings' disease. One patient had unequivocal hypopituitarism. Basal levels of growth hormone (GH), TSH, LH, and FSH were not statistically different from controls, but provocative testing revealed significant abnormalities of response of cortisol/ACTH, GH, prolactin and LH. Six out of eight patients had absent diurnal cortisol variation and five patients had elevated serum prolactin levels. Thus, in this group of patients normal pituitary-adrenal function has not been satisfactorily restored. It is clear that significant disturbances of hypothalamic-pituitary function follow megavoltage ...
The effects of key metallurgical variables on the low fluence hardening in a set of A533B model steels were evaluated over a wide range of irradiation temperatures. Above about 163 degrees C hardening increased with higher copper and nickel contents, as is typical of the pressure vessel operating regime around 290 degrees C. However, at 121 degrees C the hardening was generally lower and unaffected by copper and nickel variations. This observation of decreased hardening with lower temperature (e.g. an open-quotes invertedclose quotes temperature dependence) is tentatively attributed to a reduced contribution of copper precipitation. Tensile data for a set of commercial steels with a range of (uncontrolled) compositions also showed minimal sensitivity to copper variations at 121 degrees C. Unlike the hardness data no systematic reductions in the yield stress increases were observed between 163 and 121 degrees C. However, the ultimate tensile strength did decrease at the lower ...
Sealants for radon-resistant foundation construction must seal the gap between concrete sections. Modern sealants have such low permeability that seal performance depends only on the permeability of the material that contacts the sealant. The surface permeability of concrete walls and floors was measured by a specially designed permeameter, which measures the airflow induced by a pressure difference across a temporary test seal applied to the surface. The permeability of bulk concrete is about 10"-"1"5 m"2. Areas free of surface defects had surface permeability ranging from 10"-"1"4 to 10"-"1"6 m"2. However, surface defects are common on concrete wall surfaces, which increase the permeability to >10"-"1"2 m"2, too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Radon-resistant seals require either extended contact widths or mechanical removal of the surface layer and defects. (au) (4 refs.).